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1

The optimum tilt angle for flat-plate solar collectors in Iran  

Science Journals Connector (OSTI)

This paper aims at determining the optimum tilt angle for south facing flat-plate solar collectors in Iran. Solar radiation on a horizontal surface was estimated by applying an empirical method and employing meteorological data from 80 selected cities. A mathematical model was used for estimating the solar radiation at different tilt angles. Daily monthly seasonally bi-annually and yearly optimum tilt angles and solar radiations were determined for 80 selected cities. Recommendations were made on the optimum tilt angle adjustment for different places in the country in order to benefit the best solar radiation available. The averaged benefits of annual solar radiation for 80 cities were 21.3% for daily 21% for monthly 19.6% for seasonal 19.3% for bi-annual and 13.3% for yearly adjustments compared with the radiation on the horizontal collector. Based on these results adjusting tilt angles at least twice a year is recommended. Optimum tilt angles for cloudy sky cities with a low clearness index are lower than those for cities at the same latitude angle having a higher clearness index. In addition to latitude angle the climate conditions are also important for determining the optimum tilt angle.

Farzad Jafarkazemi; S. Ali Saadabadi; Hadi Pasdarshahri

2012-01-01T23:59:59.000Z

2

On the performance of the flat plate solar heat collector  

Science Journals Connector (OSTI)

A flat plate heat collector was constructed for the purpose of heating water by solar energy. It was erected facing south, tilted to the horizontal at the optimum tilt angle, and tested ... was found, for the dim...

M. K. Elnesr; A. M. Khalil

1965-01-01T23:59:59.000Z

3

Flat plate solar collector with a cantilevered mirror  

SciTech Connect

The use of flat booster mirrors with flat plate collectors provides moderate solar flux concentration and enhanced performance especially when the mirrors are seasonally adjusted. Curved mirrors provide higher flux concentration and a practical system has been developed where the booster mirror is bent elastically. The system employs a single cantilever mirror which is located below a conventional flat plate collector. The mirror is clamped at the base of the collector panel and its free end is deflected upward; a smaller deflection is used in the fall and winter than in the spring and summer. The prototype system consists of a 0.9 by 2.5 m collector panel mounted on its side (horizontal fluid flow) and a 2.7 by 2.5 m elastic mirror. The mirror is made with aluminum sheet with an adherent aluminized acrylic film. The system has been designed for mounting on horizontal surfaces at latitudes of 10 to 50/sup 0/.

Cohen, S.; Larson, D.C.

1981-01-01T23:59:59.000Z

4

Spectrally Solar Selective Coatings for Colored Flat Plate Solar Thermal Collectors  

Science Journals Connector (OSTI)

The paper is a review on the state-of-the-art on colored materials (absorbers and glazings) for solar thermal flat plate collectors obtained world-wide. The ... input for novel, market-acceptable flat plate solar

Luminita Isac; Alexandru Enesca…

2014-01-01T23:59:59.000Z

5

Thermal Load based Adaptive Tracking for Flat Plate Solar Collectors  

Science Journals Connector (OSTI)

Abstract The energy output of solar-thermal systems using flat plate collectors can be improved by tracking. Tracking is well known as a path for increasing the amount of solar radiation received by the collector; additionally the paper proposes a new concept that considers the inverse tracking as a viable option for protecting the collectors against overheating. An analysis of the thermal energy output and conversion efficiency is done considering forward tracking in three different days with different radiation profile (cloudy, sunny and mixed days), followed by an analysis of the inverse tracking concept. The in-field data show that there is a limiting angle below which inverse tracking is not effective and this value is estimated at 40° as compared with the optimal orientation. A logical scheme is proposed based on four different programs for forward tracking, inverse tracking, maximum inverse tracking or fixing the collector; this decisional scheme covers a broad range of functional situations having as central concept the production of thermal energy only when needed, for satisfying the demand, decreasing the energy consumption for forced circulation and supporting the systems reliability and safety.

Mircea Neagoe; Ion Visa; Bogdan G. Burduhos; Macedon D. Moldovan

2014-01-01T23:59:59.000Z

6

Multi-objective genetic algorithm for the optimization of a flat-plate solar thermal collector  

Science Journals Connector (OSTI)

We present a multi-objective genetic algorithm we developed for the optimization of a flat-plate solar thermal collector. This collector consists of a waffle-shaped Al substrate with...

Mayer, Alexandre; Gaouyat, Lucie; Nicolay, Delphine; Carletti, Timoteo; Deparis, Olivier

2014-01-01T23:59:59.000Z

7

Investigation of the fluid temperature field inside a flat-plate solar collector  

Science Journals Connector (OSTI)

An experimental study was conducted to investigate fluid temperature fields inside a flat-plate solar collector tube. The results show the highest fluid ... tube, whereas, the temperature field in the horizontal ...

Gurveer Sandhu; Kamran Siddiqui

2014-11-01T23:59:59.000Z

8

Outdoor and Indoor Testing to Increase the Efficiency and Durability of Flat Plate Solar Thermal Collectors  

Science Journals Connector (OSTI)

This paper presents the test performed on the solar thermal flat plate collector and the effect of saline aerosol on the solar thermal conversion; an assembly of testing rigs developed ... presented; the rigs all...

Daniela Ciobanu; Ion Visa; Anca Duta…

2014-01-01T23:59:59.000Z

9

An experimental investigation on a solar still with an integrated flat plate collector  

Science Journals Connector (OSTI)

Abstract This work promotes the performance of the single basin solar still by means of preheating the saline water using an integrated flat plate collector arrangement. A conventional single slope single basin still and a single slope flat plate collector basin still (FPCB still) are fabricated with the same basin area of 1 m2. The FPCB still is fabricated similar to a conventional still, with the integration of a horizontal flat plate collector arrangement to form six small compartments in the basin. The projected space between the consecutive basins acts as an extended surface which increases the temperature of the basin as well as the flat plate collector where the saline water is preheated before it enters the basin. Due to separate compartments (absorber plate) in the basin, the mass of water reduces and the evaporation rate increases for the same depth of water in the basin. Experiments are carried out by varying the water depth in the basin and using the wick and energy storing materials in basins of both stills. The FPCB still gives about 60% higher distillate than the conventional still for the same basin condition. Economic analysis shows that the cost of distilled water for the FPCB still is lower than that for the conventional still.

T. Rajaseenivasan; P. Nelson Raja; K. Srithar

2014-01-01T23:59:59.000Z

10

A SOLAR STILL AUGMENTED WITH A FLAT-PLATE COLLECTOR AND A REFLECTOR  

E-Print Network (OSTI)

A SOLAR STILL AUGMENTED WITH A FLAT-PLATE COLLECTOR AND A REFLECTOR A. Saleh A. Badran Mechanical ­ Jordan Amman ­ Jordan e-mail: asaleh@philadelphia.edu.jo e-mail: badran@ju.edu.jo ABSTRACT A solar distillation system was built and tested to study the effect of increasing the solar radiation incident

11

Review of solar thermoelectric energy conversion and analysis of a two cover flat-plate solar collector  

E-Print Network (OSTI)

The process of solar thermoelectric energy conversion was explored through a review of thermoelectric energy generation and solar collectors. Existing forms of flat plate collectors and solar concentrators were surveyed. ...

Hasan, Atiya

2007-01-01T23:59:59.000Z

12

Investigation of the flow field inside flat-plate collector tube using PIV technique  

SciTech Connect

The thermofluid process inside the tube of flat-plate collectors is complex because the non-uniform heating of the tube results in the formation of stably and unstably stratified layers of fluid that interact with each other. The measurement and investigation of the flow behaviour inside the collector tube is very challenging. We report on a novel application of the particle image velocimetry (PIV) technique to remotely measure the velocity field inside the collector tube. The two-dimensional velocity fields were measured in the midplane of a collector tube for the Reynolds number range of 150-900 at unheated and four different heating conditions. We have presented and discussed in detail the technique implementation and the associated challenges. The results have shown that the collector heating significantly alters the structure and magnitude of the mean velocity field and influences the heat transfer to the fluid. It is observed that the collector heating causes a significant asymmetry in the mean velocity profiles over the given range of Reynolds numbers and heating conditions. (author)

Sookdeo, Steven [Department of Mechanical and Industrial Engineering, Concordia University, Montreal (Canada); Siddiqui, Kamran [Department of Mechanical and Industrial Engineering, Concordia University, Montreal (Canada); Department of Mechanical and Materials Engineering, University of Western Ontario, London (Canada)

2010-06-15T23:59:59.000Z

13

Solar Radiation Data Manual for Flat-Plate and Concentrating Collectors  

Office of Scientific and Technical Information (OSTI)

Solar Radiation Data Manual Solar Radiation Data Manual for Flat-Plate and Concentrating Collectors NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefuleness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply iots endorsement, recommendation, or favoring by the United States government or any agency thereof. The views and opinions of authors expressed herein do not

14

A new solar radiation data manual for flat?plate and concentrating collectors  

Science Journals Connector (OSTI)

A new solar radiation data manual is nearing completion by the National Renewable Energy Laboratory’s (NREL’s) Analytic Studies Division under the Solar Radiation Resource Assessment Project and the Photovoltaic Solar Radiation Research Task. These tasks are funded and monitored by the Photovoltaics Branch of the Department of Energy’s Office of Energy Efficiency and Renewable Energy. The new manual is entitled Solar Radiation Data Manual for Flat?Plate and Concentrating Collectors. For designers and engineers of solar energy related systems it gives the solar resource available for various types of collectors for 239 stations in the United States and its territories. The data in the manual are modeled using diffuse horizontal and direct beam solar radiation values from the National Solar Radiation Data Base (NSRDB). The NSRDB contains modeled (93%) and measured (7%) global horizontal diffuse horizontal and direct beam solar radiation for 1961–1990. This paper describes what is contained in the new data manual and how it was developed.

W. Marion; S. Wilcox

1994-01-01T23:59:59.000Z

15

Study of a solar air flat plate collector: use of obstacles and application for the drying of grape  

Science Journals Connector (OSTI)

In the solar air flat plate collector, the insufficiency of the thermal exchange between the fluid and the absorber obliges the user to enhance their optimization. This low thermal exchange does not allow these systems to obtain their best performance or the best thermal efficiency. In our experimental study, which consists of a solar energy simulation, we have sought to improve the efficiency–temperature rise couple of the flat plate solar collector by considering several types of obstacles disposed in rows in the dynamic air vein of the flat collector. Thus, we have proceeded to the application of the best two systems (WDL1) and (TL) for drying an agricultural product grape. By comparing with the collector without obstacles (WO), the thermal transfers and, consequently, the output temperature (TOC) and the collector efficiency (?) are clearly improved. The drying times obtained with the proposed systems are very interesting. The heat quantities obtained in the case of WDL1 are very important compared with the collector WO. However, the entry to the drying cupboard of this high temperature (TOC) in the vicinity of the solar midday must be limited to the maximal value demanded by the considered product.

A Abene; V Dubois; M Le Ray; A Ouagued

2004-01-01T23:59:59.000Z

16

Convective Heat Transfer from Exposed Flat Horizontal Surface in Outdoorconditions at Low Wind Speeds: An Application to Flat Plate Solar Collector  

Science Journals Connector (OSTI)

Estimation of various heat losses in flat plate solar collectors is important for their thermal performance evaluation under different operating conditions. Upward heat losses have a major contribution in the ...

Suresh Kumar; S. C. Mullick

2009-01-01T23:59:59.000Z

17

Radiation Incident on Tilted Collectors  

Science Journals Connector (OSTI)

For solar energy system design purposes, observations of solar radiation on a horizontal surface must be converted to values on a tilted energy collector. An empirical conversion relationship, introduced by Liu and Jordan (1960) and based on ...

P. J. Robinson

1981-12-01T23:59:59.000Z

18

Coaxial extrusion conversion concept for polymeric flat plate solar collectors. Final technical report, September 30, 1978-December 31, 1979  

SciTech Connect

This study investigated materials and processes for fundamental improvements in flat-plate solar collector cost and performance. The goal was to develop a process for direct conversion of inexpensive raw materials into a completed solar collector unit, without labor intensive assembly operations. It was thought that materials carefully matched to the process and end-use environment would substantially reduce collector costs, as compared to conventional industry practice. The project studied the feasibility of a cost-effective, glazed solar collector, with low labor input, utilizing a coaxial extrusion of compatible polymeric materials. This study evaluated all considered materials for the desired application. In addition, there was a trial extrusion of the leading candidate glazing and absorber materials, which resulted in successfully performing a coaxial extrusion of one cell. At the time the study was conducted, there were no materials available that met the necessary requirements for the specified utilization. It was recommended that, if potentially compatible materials become available, further investigation into the suitability of those materials be researched. Then, if a suitable material was found, proceeding into Phase II would be recommended.

Rhodes, R.O.; Chapman, N.J.; Chao, K.C.; Sorenson, K.F.

1980-01-01T23:59:59.000Z

19

A dynamic thermal performance model for flat-plate solar collectors based on the thermal inertia correction of the steady-state test method  

Science Journals Connector (OSTI)

Abstract In determining the dynamic thermal performance of a flat-plate solar collector, when the instantaneous solar irradiance changes sharply at one moment, most of the existing models cannot accurately predict the momentary thermal characteristics of outlet temperature and useful heat gain. In the present study, an analytical model in the form of series expansion is put forward to depict the momentary thermal characteristics of flat-plate solar collectors. The analytical model reveals that, instantaneous useful heat gain of a solar collector at one moment consists of the steady-state useful heat gain and corresponding thermal inertia correction. The model is then validated by the experimental data. It indicates that the analytical model can properly predict the dynamic thermal performance of the solar air collector. Besides, the model pertains to other types of solar thermal collectors, if they can be tested by the steady-state test method.

Jie Deng; Yupeng Xu; Xudong Yang

2015-01-01T23:59:59.000Z

20

Experimental investigation of various designs of solar flat plate collectors: Application for the drying of green chili  

Science Journals Connector (OSTI)

This paper presents an experimental study by comparing between the thermal performance of three types of solar air flat plate collectors FPCs: (i) without obstacles (ii) with rectangular obstacles and (iii) with trapezoidal obstacles in the air flow duct. In order to determine the best performing model we have proceeded to reversing the flow direction in each collector and comparing the six obtained models under outdoor conditions. All collectors were designed constructed and tested in the University of Biskra (Algeria) in a stand facing south at an inclination angle equal to the local latitude. Thus we have proceeded to the application of the best system for the drying of the green chili. We have sought to determine the moisture content and loss of mass for the forced convection hot air drying of the product and their temperature dependence. In comparison with the recent literature at different air mass flow the highest efficiencies (77%) were obtained from the FPC with trapezoidal obstacles when the air was blown down at air flow rate 0.043?kg/s. In addition this study has allowed us to show that (i) for a same geometry the highest efficiencies were always obtained when the air was blown down in the solar air FPC and (ii) the use of obstacles in the air flow duct of the FPCs is an efficient method to improve their performances especially when the air is blown down. The obstacles ensure a good air flow under the absorber plate create the turbulence and reduce the dead zones in the collector.

Adnane Labed; Noureddine Moummi; Adel Benchabane

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Design and simulation of a prototype of a small-scale solar CHP system based on evacuated flat-plate solar collectors and Organic Rankine Cycle  

Science Journals Connector (OSTI)

Abstract This paper presents a dynamic simulation model of a novel prototype of a 6 kWe solar power plant. The system is based on the coupling of innovative solar thermal collectors with a small Organic Rankine Cycle (ORC), simultaneously producing electric energy and low temperature heat. The novelty of the proposed system lies in the solar collector field, which is based on stationary evacuated flat-plate solar thermal collectors capable to achieve the operating temperatures typical of the concentrating solar thermal collectors. The solar field consists of about 73.5 m2 of flat-plate evacuated solar collectors, heating a diathermic oil up to a maximum temperature of 230 °C. A diathermic oil storage tank is employed in order to mitigate the fluctuations due to the variability of solar energy availability. The hot diathermic oil exiting from the tank passes through an auxiliary gas-fired burner which provides eventual additional thermal energy. The inlet temperature of the diathermic oil entering the ORC system varies as a function of the availability of solar energy, also determining an oscillating response of the ORC. The ORC was simulated in Engineering Equation Solver (EES), using zero-dimensional energy and mass balances. The ORC model was subsequently implemented in a more general TRNSYS model, including all the remaining components of the system. The model was used to evaluate the energy and economic performance of the solar CHP system under analysis, in different climatic conditions. The results show that the efficiency of the ORC does not significantly vary during the year, remaining always close to 10%. On the other hand, the efficiency of the solar collectors is very high in summer (>50%) and significantly lower during the coldest winter days (down to 20%). Pay-back periods are extremely attractive in case of feed-in tariffs (about 5 years), whereas the profitability of the system is scarce when no public funding is available. A sensitivity analysis was also performed, in order to determine the combination of system/design parameters able to maximize the thermo-economic performance of the system. It was found that the system may be economically feasible for the majority of locations in the Mediterranean area (pay-back periods around 10 years), whereas the profitability is unsatisfactory for Central-Europe sites.

Francesco Calise; Massimo Dentice d’Accadia; Maria Vicidomini; Marco Scarpellino

2015-01-01T23:59:59.000Z

22

Analytical investigation of collector optimum tilt angle at low latitude  

Science Journals Connector (OSTI)

An analytical investigation on the optimum tilt angle for solar collectors at low latitude a case study of Universiti Teknologi PETRONAS (UTP) 4.39°N and 100.98°E Malaysia is presented in this work. The study employed Hay Davies Klucher and Reindl (HDKR) anisotropic sky model to evaluate the available hourly solar radiation on inclined surface using the location metrological data. The tilt angles considered were 0° to 30° in step of 3° with the inclusion of the location latitude angle. The study employed the ratio of global solar radiation on tilted surface to the global solar radiation on horizontal surface in the decision of the optimum tilt. The system equations were converted to MATLAB codes to solve for the optimum tilt angles. The results show that the optimum tilt varies monthly but gave zero degree for south facing collector for the months of April to August; thus the investigation also considered north facing orientation for the months of April to September. The optimum annual tilt angle for the location using the tilt to horizontal radiation ratio was found to be equal to the location latitude angle. Using the conventional average of the monthly optimum tilt angles the annual optimum tilt angle was found to be 9.75° for south facing collector. Considering seasonal optimum tilt angle for the location using the tilt to horizontal radiation ratio 18° facing south was found to be the optimum tilt angle for rainy season (September to March) and 15° facing north for dry season (April to August). Employing the average of monthly optimum tilt method the seasonal optimum tilt angle was found to be 17° for rainy season and 12° facing north dry season. The effect of dust on the collector was considered with reference to literature and the annual tilt angle of 15° facing south was recommended for the location in the case of large solar collector that cannot be monthly or seasonally adjusted.

Ogboo Chikere Aja; Hussain H. Al-Kayiem; Zainal Ambri Abdul Karim

2013-01-01T23:59:59.000Z

23

Optimum tilt angle and orientation for solar collectors in Syria  

Science Journals Connector (OSTI)

One of the important parameters that affect the performance of a solar collector is its tilt angle with the horizon. This is because of the variation of tilt angle changes the amount of solar radiation reaching the collector surface. A mathematical model was used for estimating the solar radiation on a tilted surface, and to determine the optimum tilt angle and orientation (surface azimuth angle) for the solar collector in the main Syrian zones, on a daily basis, as well as for a specific period. The optimum angle was computed by searching for the values for which the radiation on the collector surface is a maximum for a particular day or a specific period. The results reveal that changing the tilt angle 12 times in a year (i.e. using the monthly optimum tilt angle) maintains approximately the total amount of solar radiation near the maximum value that is found by changing the tilt angle daily to its optimum value. This achieves a yearly gain in solar radiation of approximately 30% more than the case of a solar collector fixed on a horizontal surface.

Kamal Skeiker

2009-01-01T23:59:59.000Z

24

latitude tilt | OpenEI  

Open Energy Info (EERE)

latitude tilt latitude tilt Dataset Summary Description (Abstract): Monthly Average Solar Resource for flat-plate collectors tilted at latitude for Nepal. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented due south at an angle from horizontal equal to the latitude of the collector location. Source U.S. National Renewable Energy Laboratory (NREL) Date Released April 12th, 2005 (9 years ago) Date Updated October 30th, 2007 (7 years ago) Keywords atmospheric water vapor GIS latitude tilt Nepal NREL solar SWERA TILT UNEP Data application/zip icon Download Shapefile (zip, 25.6 KiB) text/csv icon Download Data (csv, 36.2 KiB)

25

Development of 400/sup 0/F sealants for flat plate solar collector construction and installation. Final report, 1 October 1978-30 September 1979  

SciTech Connect

Twenty candidate sealants representing ten different polymer types were evaluated as potential solar collector sealants. Polymer types tested included epichlorohydrin rubber, EPDM rubber, silicone, polysulfide, acrylate rubber, and a fluoroelastomer. Initial screening of sealants consisted of measuring high temperature stability and adhesion retention. Several sealant compositions exhibited satisfactory performance in these tests and were selected for further evaluation. These materials were based on an EPDM rubber, a Viton fluoroelastomer, and silicone polymers. Further testing of these candidate materials included determination of adhesion retention under uv/water/heat conditions, fogging temperature, low temperature flexibility, and physical properties. Four silicone-based materials appeared to be suitable candidates for sealing solar collectors. These include Dow Corning 90-006-02 and 3120, General Electric 1200, and PR-1939 from Products Research and Chemical Corporation.

Morris, L.; Schubert, R.J.

1980-03-01T23:59:59.000Z

26

A mathematical model for the performance of the compressed-film, floating-deck, flat-plate solar-energy collector  

E-Print Network (OSTI)

A MATHEMATICAL MODEL FOR THE PERFORMANCE OP THE COMFR. . 'SSED-FILM PLOATING-DECK, PLAT-PLATE SOLAR-ENERGY COLI CTOR A Thesis HO-KAI CHAN Submitted to the Graduate Co1lege of Texas A&M University in partial fulfillment of 0he requirement... for the degree of FiASTER OP SCIENCE August 197~ MaJor SubJect: Chemical Engineering A MATHEMATICAL MODEL FOR THE PERFORMANCE OF THE COMPRESSED-FILM, FLOATING-DECK~ PLAT-PLATE SOLAR-ENERGY COLLECTOR A Thesis by HO-KAI CHAN Approved as to style...

Chan, Ho-Kai

2012-06-07T23:59:59.000Z

27

latitutde tilt irradiance | OpenEI  

Open Energy Info (EERE)

latitutde tilt irradiance latitutde tilt irradiance Dataset Summary Description (Abstract): Monthly Average Solar Resource for flat-plate collectors tilted at latitude for Bangladesh. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented due south at an angle from horizontal equal to the latitude of the collector location. Source NREL Date Released April 12th, 2005 (9 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords atmospheric water vapor GEF GIS latitutde tilt irradiance NREL solar SWERA TILT UNEP Data text/csv icon Download Data (csv, 35.5 KiB) application/zip icon Download Shapefile (zip, 26.7 KiB) Quality Metrics

28

Solar: monthly latitude tilt GIS data at 40km resolution for Bangladesh  

Open Energy Info (EERE)

latitude tilt GIS data at 40km resolution for Bangladesh latitude tilt GIS data at 40km resolution for Bangladesh from NREL Dataset Summary Description (Abstract): Monthly Average Solar Resource for flat-plate collectors tilted at latitude for Bangladesh. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented due south at an angle from horizontal equal to the latitude of the collector location. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The

29

Solar: monthly and annual latitude tilt horizontal GIS data at 40km  

Open Energy Info (EERE)

latitude tilt horizontal GIS data at 40km latitude tilt horizontal GIS data at 40km resolution for Nepal from NREL Dataset Summary Description (Abstract): Monthly Average Solar Resource for flat-plate collectors tilted at latitude for Nepal. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented due south at an angle from horizontal equal to the latitude of the collector location. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The

30

Latitude Based Model for Tilt Angle Optimization for Solar Collectors in the Mediterranean Region  

Science Journals Connector (OSTI)

Abstract This paper inspects the different parameters that intervene in the determination of the optimal tilt angle for maximum solar energy collection. It proposes a method for calculating the optimal tilt angle based upon the values of the daily global solar radiation on a horizontal surface. A computer program using the mathematical model to calculate the solar radiation incident on an inclined surface as a function of the tilt angle is implemented. Four years data of daily global solar radiation on a horizontal surface in 35 sites in different countries of the Mediterranean region is used. The program assumes a due south orientation of the collectors and it determines the optimal tilt angle for maximum solar radiation collection for sites in the Mediterranean region. A regression analysis using the results of the computer simulation is conducted to develop a latitude based tilt angle optimization mathematical model for maximum solar radiation collection for the sites. We tested both a linear and a quadratic model (of the form ax2+bx) for representing the relationship between the annual optimal tilt angle and the site's latitude. The quadratic model is better; it provides very high prediction accuracy. 99.87% of the variation in the annual optimal tilt angle is explained by the variability in site's latitude with an average residual angle of only 0.96° for all 35 sites studied. It also gives an average percentage decrease in the annual solar radiation of only 0.016% when compared with actual optimal tilt angles.

Hassane Darhmaoui; Driss Lahjouji

2013-01-01T23:59:59.000Z

31

A theoretical study on area compensation for non-directly-south-facing solar collectors  

Science Journals Connector (OSTI)

Solar energy integrated with the building is an important approach for the synchronous development of solar energy and architecture. The energy gain of the solar collector integrated with the pitched roof has been greatly influenced by the roof azimuth and tilted angle. Investment cost of the collectors is mainly decided by the size of the collector area. Accordingly, it is significant for solar building design to economically determinate the area compensation of the solar collector at different azimuth and tilted angles. Take Kunming and Beijing as examples, area compensation for the flat-plate tube-fin solar collector used in southern regions and the evacuated tube collector with cylindrical absorbers used in northern regions in China have been theoretically calculated. The results to some extent show that the daily horizontal solar radiation, ambient temperature, the azimuth and tilted angle of the collector integrated into the roof have an influence on the area compensation. The azimuth angle and tilted angle of the roof are the main factors that influence the A/A0, which is defined as the collector area ratio of the non-south-facing collectors to the south-facing ones with the optimal tilted angle. Comparative studies found that the range of A/A0 for the evacuated tube collector used in the northern regions is close to that for the flat-plate tube-fin solar collector used in the southern regions. When the pitched roof tilted angle ? ? [25°, 45°] and the azimuth angle ??? ? 30°, the collectors can intercept a lot of solar radiant-energy. Considering the economic situations of the ordinary consumers in China, the optimal area compensation A/A0 ? 1.30 is recommended in this paper.

Sheng-Xian Wei; Li Ming; Xi-Zheng Zhou

2007-01-01T23:59:59.000Z

32

System Advisor Model: Flat Plate Photovoltaic Performance Modeling Validation Report  

SciTech Connect

The System Advisor Model (SAM) is a free software tool that performs detailed analysis of both system performance and system financing for a variety of renewable energy technologies. This report provides detailed validation of the SAM flat plate photovoltaic performance model by comparing SAM-modeled PV system generation data to actual measured production data for nine PV systems ranging from 75 kW to greater than 25 MW in size. The results show strong agreement between SAM predictions and field data, with annualized prediction error below 3% for all fixed tilt cases and below 8% for all one axis tracked cases. The analysis concludes that snow cover and system outages are the primary sources of disagreement, and other deviations resulting from seasonal biases in the irradiation models and one axis tracking issues are discussed in detail.

Freeman, J.; Whitmore, J.; Kaffine, L.; Blair, N.; Dobos, A. P.

2013-12-01T23:59:59.000Z

33

Flat-Plate Photovoltaic System Basics | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Flat-Plate Photovoltaic System Basics Flat-Plate Photovoltaic System Basics Flat-Plate Photovoltaic System Basics August 20, 2013 - 4:03pm Addthis The most common photovoltaic (PV) array design uses flat-plate PV modules or panels. These panels can be fixed in place or allowed to track the movement of the Illustration of a cutaway of a typical flat-plate module. The layers, in order from top to bottom, are: cover film, solar cell, encapsulant, substrate, cover film, seal, gasket, and frame. One typical flat-plate module design uses a substrate of metal, glass, or plastic to provide structural support in the back; an encapsulant material to protect the cells; and a transparent cover of plastic or glass. sun. They respond to sunlight that is direct or diffuse. Even in clear skies, the diffuse component of sunlight accounts for between 10% and 20%

34

Solar: monthly and annual average latitude tilt GIS data at 40km resolution  

Open Energy Info (EERE)

Mexico, Central America, and the Caribbean Islands from NREL Mexico, Central America, and the Caribbean Islands from NREL Dataset Summary Description (Abstract): Monthly Average Solar Resource for flat-plate collectors tilted at latitude, for Mexico, Central America, and the Caribbean Islands. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented due south at an angle from horizontal equal to the latitude of the collector location. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The

35

Solar: monthly and annual average latitude tilt GIS data at 40km resolution  

Open Energy Info (EERE)

Ghana from NREL Ghana from NREL Dataset Summary Description (Abstract): Monthly Average Solar Resource for flat-plate collectors tilted at latitude for Ghana. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented horizontally. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The data were developed from NREL's Climatological Solar Radiation (CSR) Model. This model uses information on cloud cover, atmospheric water vapor and trace gases, and the amount of aerosols in the atmosphere to

36

Chapter 3 - Solar Energy Collectors  

Science Journals Connector (OSTI)

Abstract Chapter 3 gives a review of solar collectors which are the main components of any solar system. The review includes various types of stationary and sun-tracking collectors. The stationary collectors include flat-plate collectors (FPCs), under which glazing materials, collector absorbing plates, and collector construction are presented; compound parabolic collectors (CPCs) and evacuated tube collectors (ETCs). The sun-tracking concentrating collectors section cover parabolic trough collectors (PTCs), which include parabola construction and tracking mechanisms; Fresnel collectors; parabolic dish reflector and heliostat field collector. This review is followed by the optical and thermal analysis of both \\{FPCs\\} and concentrating collectors. The analysis for \\{FPCs\\} includes both water and air type systems whereas the analysis for concentrating collectors includes the CPC and the PTC. The analysis of flat-plate water collectors starts with an analysis of the absorbed solar radiation followed by collector energy losses, temperature distribution between the tubes, collector efficiency factor, heat removal factor, flow factor, and thermal efficiency. This is followed by practical considerations concerning FPCs. Subsequently, concentrating collectors are considered which include optical and thermal analysis of a CPC and optical and thermal analysis of PTCs. The chapter includes also the second law analysis of solar thermal systems and includes minimum entropy generation rate, optimum collector temperature, and non-isothermal collector analysis.

Soteris A. Kalogirou

2014-01-01T23:59:59.000Z

37

Flat-Plate Photovoltaic Module Basics | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Module Basics Module Basics Flat-Plate Photovoltaic Module Basics August 20, 2013 - 4:25pm Addthis Flat-plate photovoltaic (PV) modules are made of several components, including the front surface materials, encapsulant, rear surface, and frame. Front Surface Materials The front surface of a flat-plate PV module must have a high transmission in the wavelengths that can be used by the solar cells in the module. For example, for silicon solar cells, the top surface must have high transmission of light with wavelengths from 350 to 1200 nm. Also, reflection from the front surface should be minimal. An antireflection coating added to the top surface can greatly reduce the reflection of sunlight, and texturing of the surface can cause light that strikes the surface to stay within the cells. Unfortunately, these textured

38

Distributed Roughness Receptivity in a Flat Plate Boundary Layer  

E-Print Network (OSTI)

- Distributed Receptivity . . . . . 6 2. FACILITY DESCRIPTION - THE KLEBANOFF–SARIC WIND TUNNEL 11 2.1 Test Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 Fan and Motor... of this dissertation describes the Klebanoff–Saric Wind Tunnel facility, which was used for this experiment. Section 3 describes the experimental setup (roughness design and the flat plate model) and defines the metrics by which the flow field is decomposed...

Kuester, Matthew Scott

2014-04-18T23:59:59.000Z

39

Wave interaction with a fixed vertical flat plate  

E-Print Network (OSTI)

. Hydrofoil definition sketch. The sharp-edged gust problem and the problem of a step-wise cnange in the velocity perpendicular to the foil offers insight into the response of a foil subject to an oscillating fluid. A sharp-edged gust with an initial... forces on a thin flat plate with a standard hydrofoil thickness was determined experimentally in a two-dimensional wave tank. Non-dimensional parameters were plotted and used to evaluate the data. It was shown that lift can be generated on a flat...

Glover, Lanny Bruce

1985-01-01T23:59:59.000Z

40

High-resolution maps of solar collector performance using a climatological solar radiation model  

SciTech Connect

This paper will present a new methodology for producing estimates of the monthly and annual average performance of different types of flat-plate and concentrating solar collectors. The estimates are made on a uniform spatial grid with 40 km resolution. These estimates should be highly useful both to create maps to facilitate visualization of the solar resource, and as the basic data behind analytical studies of solar resources, deployment scenarios, CO{sub 2} mitigation strategies, and economic assessments. Their initial use of this methodology will be in the continental United States, where supporting data is available to evaluate the model outputs. In future years the authors hope to utilize this technique world-wide, especially in areas where the surface data are lacking. The National Renewable Energy Laboratory (NREL, Golden, CO) has developed the Climatological Solar Radiation (CSR) model to estimate climatological averages of daily-total solar radiation at a 40 km spatial resolution. The CSR model is operational and has been usefully applied to the US as well as several international areas. The model uses, as input, monthly climatological mean values of cloud cover, precipitable water vapor, aerosol optical depth, surface albedo, and total column ozone. These input parameters are available from various sources such as NASA and NCDC (National Climatic Data Center). The outputs from the original version of CSR are monthly mean daily total values of Global Horizontal, Direct Normal, and Diffuse radiation. Their latest revision of the model allows them to calculate the monthly mean output for the various collector types such as tilted flat-plate surfaces, one- and two-axis flat-plate collectors, and concentrating collectors.

George, R.L.; Maxwell, E.L.

1999-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Solar collector  

DOE Patents (OSTI)

The field of this invention is solar collectors, and more particularly, the invention pertains to a flat plate collector that employs high performance thin films. The solar collector of this invention overcomes several problems in this field, such as excessive hardware, cost and reliability, and other prior art drawbacks outlined in the specification. In the preferred form, the apparatus features a substantially rigid planar frame (14). A thin film window (42) is bonded to one planar side of the frame. An absorber (24) of laminate construction is comprised of two thin film layers (24a, 24b) that are sealed perimetrically. The layers (24a, 24b) define a fluid-tight planar envelope (24c) of large surface area to volume through which a heat transfer fluid flows. Absorber (24) is bonded to the other planar side of the frame. The thin film construction of the absorber assures substantially full envelope wetting and thus good efficiency. The window and absorber films stress the frame adding to the overall strength of the collector.

Wilhelm, William G. (Cutchogue, NY)

1982-01-01T23:59:59.000Z

42

Solar: monthly and annual average latitude tilt GIS data at 40km resolution  

Open Energy Info (EERE)

China from NREL China from NREL Dataset Summary Description (Abstract): Monthly Average Solar Resource for flat-plate collectors tilted at latitude for China. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented due south at an angle from horizontal equal to the latitude of the collector location. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The data were developed from NREL's Climatological Solar Radiation (CSR) Model. This model uses information on cloud cover, atmospheric water vapor and trace gases, and the amount of aerosols in the atmosphere to calculate the monthly average daily total insolation (sun and sky) falling on a horizontal surface. Existing ground measurement stations

43

Energy and exergy analysis of a new flat-plate solar air heater having different obstacles on absorber plates  

Science Journals Connector (OSTI)

This study experimentally investigates performance analysis of a new flat-plate solar air heater (SAH) with several obstacles (Type I, Type II, Type III) and without obstacles (Type IV). Experiments were performed for two air mass flow rates of 0.0074 and 0.0052 kg/s. The first and second laws of efficiencies were determined for \\{SAHs\\} and comparisons were made among them. The values of first law efficiency varied between 20% and 82%. The values of second law efficiency changed from 8.32% to 44.00%. The highest efficiency were determined for the SAH with Type II absorbent plate in flow channel duct for all operating conditions, whereas the lowest values were obtained for the SAH without obstacles (Type IV). The results showed that the efficiency of the solar air collectors depends significantly on the solar radiation, surface geometry of the collectors and extension of the air flow line. The largest irreversibility was occurring at the SAH without obstacles (Type IV) collector in which collector efficiency is smallest. At the end of this study, the energy and exergy relationships are delivered for different SAHs.

Ebru Kavak Akpinar; Fatih Koçyi?it

2010-01-01T23:59:59.000Z

44

Solar Radiation Data Manual for Flat-Plate and Concentrating...  

Office of Scientific and Technical Information (OSTI)

latitude, and latitude plus 15. These trackers pivot on their single axis to track the sun, facing east in the morning and west in the afternoon. Large collectors can use an axis...

45

Experimental Investigations of Vortex Induced Vibration of A Flat Plate in Pitch Oscillation  

E-Print Network (OSTI)

A bluff structure placed in a flowing fluid, may be subjected to vortex-induced vibrations (VIV). For a flat plate with only rotational degree of freedom, the VIV is rotational oscillation. Based on the experimental investigation, vortex...

Yang, Yi

2012-02-14T23:59:59.000Z

46

The damped natural oscillations of a gas flowing past a cascade of flat plates  

Science Journals Connector (OSTI)

We solve the problem of the natural oscillations of a gas flowing past a cascade of flat plates under the Joukowsky-Chaplygin ... case part of the energy of the oscillating gas is consumed in the formation of a ....

V. B. Kurzin

47

Desiccant cooling using unglazed transpired solar collectors  

SciTech Connect

The use of unglazed solar collectors for desiccant regeneration in a solid desiccant cooling cycle was investigated because these collectors are lower in cost than conventional glazed flat-plate collectors. Using computer models, the performance of a desiccant cooling ventilation cycle integrated with either unglazed transpired collectors or conventional glazed flat-plate collectors was obtained. We found that the thermal performance of the unglazed system was lower than the thermal performance of the glazed system because the unglazed system could not take advantage of the heat of adsorption released during the dehumidification process. For a 3-ton cooling system, although the area required for the unglazed collector was 69% more than that required for the glazed collector, the cost of the unglazed collector array was 44% less than the cost of the glazed collector array. The simple payback period of the unglazed system was half of the payback period of the glazed collector when compared to an equivalent gas-fired system. Although the use of unglazed transpired collectors makes economic sense, some practical considerations may limit their use in desiccant regeneration. 8 refs.

Pesaran, A.A. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); Wipke, K. [Stanford Univ., CA (United States)] [Stanford Univ., CA (United States)

1992-05-01T23:59:59.000Z

48

Heat Transfer -2 A heat generating ( ) flat plate fuel element of thickness 2L is covered with flat plate steel cladding of  

E-Print Network (OSTI)

with flat plate steel cladding of thickness b. The heat generated is removed by a fluid at T, which adjoins on both sides On the sketch show regions where dT/dx is zero, constant and increasing. T , h x LL bb SteelSteel

Virginia Tech

49

Flat Plate PV Module Eligibility Listing Procedure Updated 6/2/14 Senate Bill 1 (SB1) defines the solar incentive programs for California, and flat plate PV  

E-Print Network (OSTI)

programs for investor owned utility (IOU) territories, the California Solar Initiative (CSI) and the New the solar incentive programs for California, and flat plate PV modules 1 must be listed on the SB1 Solar Homes Partnership (NSHP), as well as solar incentive programs administered by publicly owned

50

EVACUATED TUBE COLLECTORS SIMPLIFY SOLAR THERMAL SYSTEM LAYOUT  

Science Journals Connector (OSTI)

SUMMARY Evacuated tube collectors (ETC's) differ quite markedly in their behaviour from the more familiar flat plate solar collectors. The consequences in cost of the entire system are investigated for a typical residential dwelling, making full use of the advantages offered by ETC's. A significant saving in initial cost as well as in maintenance costs can be realised. KEYWORDS Evacuated tube collectors; solar system layout; freeze protection; overheat protection.

C.W.J. van Koppen; P. Verhaart

1986-01-01T23:59:59.000Z

51

On the charcterization of wakes from three-dimensional single and multiple flat plates on a ground plane.  

E-Print Network (OSTI)

??A flat plate is a simplified model for a heliostat, which is a large flat tracking mirror used to reflect solar energy onto a central… (more)

Barton, Gregory Harold

1985-01-01T23:59:59.000Z

52

The distortion of a uniform flow field due to a finite flat plate  

E-Print Network (OSTI)

THE DISTORTION OI' A UNIFORM FLON FIELD DUE TO A FINITE FLAT PLATE A Thesis Lawrence Michael Zull Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May... 1970 Major Subject: Mechanical F~nin~eerin THE DISTORTION OF A UNIFORM FLOV FIELD DUE TO A FINITE FLAT PLATE A Thesis by Lawrence Michael Zull Approved as to style and content by: (Ch (Head of De artment) (Member) (Member) ~Ma 19 70 AB...

Zull, Lawrence Michael

2012-06-07T23:59:59.000Z

53

Dynamic pressure response of water flow between closely spaced roughened flat plates  

E-Print Network (OSTI)

of MASTER OF SCIENCE May 1993 Major Subject: Mechanical Engineering DYNAMIC PRESSURE RESPONSE OF WATER FLOW BETWEEN CLOSELY SPACED ROUGHENED FLAT PLATES A Thesis by JOHN CHARLES HESS Approved as to style and content by: Robert E. DeOtte, Jr. (Co.... S. , Texas A&M University Co-Chairs of Advisory Committee: Dr. R. E. DeOtte, Jr, Dr. G, L, Morrison A flat plate tester was designed and built to determine friction factors and dynamic pressures for water flow over smooth, knurl, and cavity...

Hess, John Charles

2012-06-07T23:59:59.000Z

54

A DC corona discharge on a flat plate to induce air Pierre MAGNIER1  

E-Print Network (OSTI)

with applied voltage. Moreover, with voltage higher than a threshold value, the electric discharge changes. For this purpose, different electric discharges have recently been developed, such as the "One Atmosphere Uniform to an arc regime. Figure 1: DC surface corona discharge actuator on a flat plate. 2.2. Optical Setup

Paris-Sud XI, Université de

55

Heat Transfer -1 A satellite in space orbits the sun. The satellite can be approximated as a flat plate with  

E-Print Network (OSTI)

Heat Transfer - 1 A satellite in space orbits the sun. The satellite can be approximated as a flat plate with dimensions and properties given below. (a) Calculate the solar heat flux (W/m2 is at a distance where the solar heat flux (as defined above) is 500 W/m2 , and the flat plate is oriented

Virginia Tech

56

Experimental simulation of the bubble membrane radiator using a rotating flat plate  

SciTech Connect

The Bubble Membrane Radiator (BMR), to be used in space reactor systems, uses artificial gravity imposed on the working fluid by means of the centrifugal force to pump the fluid from the radiator. Experimental and analytical studies have been initiated to understand the nature of fluid and heat transport under the conditions of rotation. An experiment is described which measures the condensation of vapor on a rotating flat plate which is oriented normal to the earth's gravity vector to simulate the BMR physics. The relationship between vapor flow rates and rotation speed of the flat plate and a number of physical parameters including amount of condensate, overall heat transfer coefficient, and condensate film thickness are studied experimentally.

Al-Baroudi, H.; Klein, A.C. (Department of Nuclear Engineering, Oregon State University, Radiation Center, C116 Corvallis, OR (USA)); Pauley, K.A. (Battelle Pacific Northwest Laboratory, Battelle Boulevard, Richland, WA (USA))

1991-01-05T23:59:59.000Z

57

Proceedings of the flat-plate solar array project research forum on photovoltaic metallization systems  

SciTech Connect

A Photovoltaic Metallization Research Forum, under the sponsorship of the Jet Propulsion Laboratory's Flat-Plate Solar Array Project and the US Department of Energy, was held March 16-18, 1983 at Pine Mountain, Georgia. The Forum consisted of five sessions, covering (1) the current status of metallization systems, (2) system design, (3) thick-film metallization, (4) advanced techniques and (5) future metallization challenges. Twenty-three papers were presented.

None

1983-11-15T23:59:59.000Z

58

File:NREL-afg-10km-tilt.pdf | Open Energy Information  

Open Energy Info (EERE)

tilt.pdf tilt.pdf Jump to: navigation, search File File history File usage Afghanistan - Annual Flat Plate Tilted at Latitude Size of this preview: 776 × 600 pixels. Full resolution ‎(1,650 × 1,275 pixels, file size: 468 KB, MIME type: application/pdf) Title Afghanistan - Annual Flat Plate Tilted at Latitude Description Afghanistan - Annual Flat Plate Tilted at Latitude Sources National Renewable Energy Laboratory Authors Donna Heimiller Related Technologies Solar, Solar-PV, Solar-10km Creation Date 2007-06-01 Extent International Countries Afghanistan UN Region Southern Asia File history Click on a date/time to view the file as it appeared at that time. Date/Time Thumbnail Dimensions User Comment current 15:30, 14 December 2010 Thumbnail for version as of 15:30, 14 December 2010 1,650 × 1,275 (468 KB) MapBot (Talk | contribs) Automated upload from NREL's "mapsearch" data

59

Preliminary Measurements From A New Flat Plate Facility For Aerodynamic Research  

SciTech Connect

This paper details the design and preliminary measurements used in the characterisation of a new flat plate research facility. The facility is designed specifically to aid in the understanding of entropy generation throughout the boundary layer with special attention given to non-equilibrium flows. Hot-wire measurements were obtained downstream of two turbulence generating grids. The turbulence intensity, integral and dissipation length scale ranges measured are 1.6%-7%, 5mm-17mm and 0.7mm-7mm, respectively. These values compared well to existing correlations. The flow downstream of both grids was found to be homogenous and isotropic. Flow visualisation is employed to determine aerodynamic parameters such as flow 2-dimensionality and the effect of the flap angle on preventing separation at the leading edge. The flow was found to be 2-dimensional over all measurement planes. The non-dimensional pressure distribution of a modern turbine blade suction surface is simulated on the flat plate through the use of a variable upper wall. The Reynolds number range based on wetted plate length and inlet velocity is 70,000-4,000,000.

D. M. McEligot; D. W. Nigg; E. J. Walsh; D. Hernon; M.R.D. Davies

2005-03-01T23:59:59.000Z

60

Acoustic boundary layer and acoustic radiation from a ribbed flat plate  

Science Journals Connector (OSTI)

The acoustic boundary?layer theory(patterned after the viscous boundary?layer theory) is derived by noting that for low frequencies where the structural wavelength is much less than the fluid acoustic wavelength there is a region about the vibrating structure which behaves as if the fluid was incompressible. The dimension of this region depends upon the particular conditions of the problem. In a paper presented by the author [J. Acoust. Soc. Am. 62 S32(A) (1977)] the theory behind the acoustic boundary layer was developed and applied to simple unit problems. In this paper the near and the far field of a force driven plate is obtained by the use of the acoustic boundary?layer theory. Two different problems are addressed. In the first instance the structure is assumed to be homogeneous while in the second problem presented a rib is attached to the flat plate. In both instances the fully coupled fluid structure problem is solved and comparisons between the exact classical approach and the proposed theory are discussed.

Mauro Pierucci

1978-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Measurements of Conversion Efficiency for a Flat Plate Thermophotovoltaic System Using a Photonic Cavity Test System  

SciTech Connect

The performance of a 1 cm{sup 2} thermophotovoltaic (TPV) module was recently measured in a photonic cavity test system. A conversion efficiency of 11.7% was measured at a radiator temperature of 1076 C and a module temperature of 29.9 C. This experiment achieved the highest direct measurement of efficiency for an integrated TPV system. Efficiency was calculated from the ratio of the peak (load matched) electrical power output and the heat absorption rate. Measurements of these two parameters were made simultaneously to assure the validity of the measured efficiency value. This test was conducted in a photonic cavity which mimicked a typical flat-plate TPV system. The radiator was a large, flat graphite surface. The module was affixed to the top of a copper pedestal for heat absorption measurements. The heat absorption rate was proportional to the axial temperature gradient in the pedestal under steady-state conditions. The test was run in a vacuum to eliminate conductive and convective heat transfer mechanisms. The photonic cavity provides the optimal test environment for TPV efficiency measurements because it incorporates all important physical phenomena found in an integrated TPV system: high radiator emissivity and blackbody spectral shape, photon recycling, Lambertian distribution of incident radiation and complex geometric effects. Furthermore, the large aspect ratio between radiating surface area and radiator/module spacing produces a view factor approaching unity with minimal photon leakage.

E.J. Brown; C.T. Ballinger; S.R. Burger; G.W. Charache; L.R. Danielson; D.M. DePoy; T.J. Donovan; M. LoCascio

2000-05-30T23:59:59.000Z

62

File:NREL-africa-tilt.pdf | Open Energy Information  

Open Energy Info (EERE)

tilt.pdf tilt.pdf Jump to: navigation, search File File history File usage Africa - Annual Flat Plate Tilted at Latitude (PDF) Size of this preview: 776 × 600 pixels. Full resolution ‎(1,650 × 1,275 pixels, file size: 5.69 MB, MIME type: application/pdf) Title Africa - Annual Flat Plate Tilted at Latitude (PDF) Description Africa - Annual Flat Plate Tilted at Latitude (PDF) Sources National Renewable Energy Laboratory Authors Donna Heimiller Related Technologies Solar, Solar-PV, Solar-40km Creation Date 2005-01-11 Extent Continent Countries Africa UN Region File history Click on a date/time to view the file as it appeared at that time. Date/Time Thumbnail Dimensions User Comment current 15:34, 14 December 2010 Thumbnail for version as of 15:34, 14 December 2010 1,650 × 1,275 (5.69 MB) MapBot (Talk | contribs) Automated upload from NREL's "mapsearch" data

63

Heat collector  

DOE Patents (OSTI)

A heat collector and method suitable for efficiently and cheaply collecting solar and other thermal energy are provided. The collector employs a heat pipe in a gravity-assist mode and is not evacuated. The collector has many advantages, some of which include ease of assembly, reduced structural stresses on the heat pipe enclosure, and a low total materials cost requirement. Natural convective forces drive the collector, which after startup operates entirely passively due in part to differences in molecular weights of gaseous components within the collector.

Merrigan, Michael A. (Santa Cruz, NM)

1984-01-01T23:59:59.000Z

64

Heat collector  

DOE Patents (OSTI)

A heat collector and method suitable for efficiently and cheaply collecting solar and other thermal energy are provided. The collector employs a heat pipe in a gravity-assist mode and is not evacuated. The collector has many advantages, some of which include ease of assembly, reduced structural stresses on the heat pipe enclosure, and a low total materials cost requirement. Natural convective forces drive the collector, which after startup operates entirely passively due in part to differences in molecular weights of gaseous components within the collector.

Merrigan, M.A.

1981-06-29T23:59:59.000Z

65

Solar collector  

SciTech Connect

A solar collector is disclosed which is tiltable about a horizontal axis so as to vary the angle at which solar radiation is received by the collector. The solar collector, which uses air as the heat transfer medium, has connected to it a pair of fixed, well-insulated air transfer passages which penetrate through into the interior of the collector at the lateral sides thereof aligned with the horizontal axis about which the collector is pivoted. The air transfer passages are insulated and are gasketed to the sides of the collector so as to improve the efficiency of the solar energy system by avoiding losses of heat from the heat transfer fluid during transfer of the fluid from the collector to the space being heated.

Stevenson, S.

1981-06-30T23:59:59.000Z

66

File:NREL-bhutan-10kmsolar-tilt.pdf | Open Energy Information  

Open Energy Info (EERE)

kmsolar-tilt.pdf kmsolar-tilt.pdf Jump to: navigation, search File File history File usage Bhutan - Annual - Flat PlateTilted at Latitude Solar Radiation Size of this preview: 776 × 600 pixels. Full resolution ‎(1,650 × 1,275 pixels, file size: 333 KB, MIME type: application/pdf) Title Bhutan - Annual - Flat PlateTilted at Latitude Solar Radiation Description Bhutan - Annual - Flat PlateTilted at Latitude Solar Radiation Sources National Renewable Energy Laboratory Authors Donna Heimiller Related Technologies Solar, Solar-PV, Solar-10km Creation Date 2009-03-03 Extent International Countries Bhutan UN Region Southern Asia File history Click on a date/time to view the file as it appeared at that time. Date/Time Thumbnail Dimensions User Comment current 15:51, 14 December 2010 Thumbnail for version as of 15:51, 14 December 2010 1,650 × 1,275 (333 KB) MapBot (Talk | contribs) Automated upload from NREL's "mapsearch" data

67

40th Fluid Dynamics Conference and Exhibit, 28 Jun -1 Jul 2010, Chicago, Illinois Transition of hypersonic flow past flat plate with  

E-Print Network (OSTI)

of hypersonic flow past flat plate with roughness elements Prahladh S Iyer , Suman Muppidi and Krishnan Mahesh and Astronautics #12;I. Introduction Studying laminar-turbulent transition in supersonic and hypersonic boundary-turbulent transition.2 Schneider3 gives a comprehensive review of the effects of roughness on hypersonic boundary layer

Mahesh, Krishnan

68

Ray Tracing of a Solar Collector Designed for Uniform Yearly Production  

Science Journals Connector (OSTI)

Abstract One of the problems with solar flat plate collectors for domestic water heating is that they produce more energy in the summer months, when the domestic hot water needs are lower than in winter months. This causes a significant difference between supply and demand and thus overheating during the summer. A method to avoid this problem is to design solar collector fields that offer a 100% of the water needs in the summer, but a small percentage during the winter, which is certainly not ideal. In this work, ray tracing is used to design a solar thermal collector that offers a more uniform production during the year. A novel geometry is chosen where the collector is split in two parts, a curved absorber and a mini parabolic concentrator. The concentrator is designed to concentrate the radiation during the midday hours of winter days and to not doing it in the midday hours of summer days. This increases the energy produced in winter and prevents the installation from overheating. In order to study the hours when this geometry will concentrate the solar radiation, ray tracing is used. As the solar collector has a design that allows the collector to be easily integrated into a facade, the simulations in the most useful architectural integration positions are simulated, those are horizontal positions, but vertical positions or any other position are suitable if the collector is installed on a roof. For each position, the amount of hours where the whole collector is working and the total radiation captured are calculated and compared with the solar radiation captured by an equivalent flat surface, which would corresponds to conventional flat plate collectors. Simulation results shows how for a concentrator designed to work properly in the 5 midday hours during the winter solstice it will not work during the 5 midday hours during the summer solstice, avoiding overheating.

David Rodriguez-Sanchez; Gary Rosengarten; Juan Francisco Belmonte Toledo; Maria Izquierdo Barrientos; Antonio Molina Navarro; Jose Antonio Almendros-Ibañez

2014-01-01T23:59:59.000Z

69

Building Energy Software Tools Directory: oTilt  

NLE Websites -- All DOE Office Websites (Extended Search)

oTilt oTilt tool_otilt oTilt is an online tool for quickly determining the optimum tilt angles for solar collectors. Site can be located in an integrated Google map, searching it using keywords (e.g. Central Park, New York) or by directly entering latitude and longitude. oTilt determines the optimum monthly, seasonal, half-yearly and fixed tilt angles for solar collectors at selected site location along with respective energy collection during these spans. Results are presented in the form of a table. Screen Shots Keywords solar radiations, radiations on tilted surface, optimum tilt angle, optimum pitch angle, collector slope Validation/Testing Methodology and validation of results is given on website Expertise Required No special expertise needed. Users More than 100.

70

Heat transfer and temperature distribution in a turbulent flow over a flat plate with an unheated starting length  

SciTech Connect

The present study is a numerical investigation of heat transfer and temperature distribution in a boundary layer formed by a flow with nonzero free stream turbulence over a flat plate with an unheated starting length. The numerical method is based on the Reynolds-averaged equations of motion and energy. As a closure for the Reynolds- averaged equations the Hinze relations for turbulent shear stresses and for turbulent heat flux are used. The Hinze equations are used instead of the usually employed Boussinesq eddy-viscosity hypothesis, because the latter does not work properly for flows with high free stream turbulence. It is shown in the present study that the influence of an unheated starting length on a temperature profile has manifested itself similarly to the influence of the free stream turbulence and resulted in a temperature profile with negative profile parameter. Unlike the flow with zero free stream turbulence, a heat transfer coefficient for the part of the plate with an unheated starting length can be less than for the fully heated plate. This difference increases with increasing level of the free stream turbulence. The family of functions that describe the influence of an unheated starting length for flows with nonzero free stream turbulence is presented.

Fridman, E.

1997-07-01T23:59:59.000Z

71

The effect of tangential mass addition on the boundary layer velocity distribution of a flat plate at zero angle of attack  

E-Print Network (OSTI)

. V . RESULTS AND DISCUSSION 16 18 20 21 24 Boundary Layer Conditions Downstream of Blowing Slot . Boundary Layer Conditions Upstream of Slot Accuracy of Data 24 40 47 VI. CONCLUSIONS AND RECOMMENDATIONS ~ 51 LITERATURE CITED 54 APPENDIX... 55 Estimation of Error Caused by Leaks in the Pressure Measuring System 56 LIST OF FIGURES Figure Page 3" x 48" Smoke Tunnel 2. Flat Plate Model 3. Schematic of Pressure System 4. Volume Flow Rates of Working Pipe Tap Orifice 14 Variation...

Miller, Edward Peter

2012-06-07T23:59:59.000Z

72

Solar collector  

SciTech Connect

The disclosure is a solar collector consisting of glass rods enclosed in a housing and mounted vertically on a roof or other elevated place to gather solar rays. The collector is fixed, with no tracking device or other moving parts. The glass rods are 6 mm or smaller in diameter, and there can be several thousand, depending on the sizes of the rods and collector. The upper ends of the rods are inclined at an angle of thirty degrees from horizontal, with the inclined surfaces occupying a plane which faces south so as to obtain maximum exposure to the winter sun. Solar rays striking the inclined ends of the rods are refracted into the rods. The rays travel down through the rods, with a predominantly parallel path of propagation being established by repeated reflections off the inside walls of the rods. The rays are emitted from the lower perpendicular ends of the rods as parallel rays of incoherent light which are directed into beam concentrators.

Clegg, J.E.

1985-01-08T23:59:59.000Z

73

Double-duty collector  

SciTech Connect

The design of a liquid solar collector that helps heat an indoor pool and household water is described. Collector design and specifications and installation of the collector are discussed.

Hill, L.; Yates, D.

1983-05-01T23:59:59.000Z

74

Tracking benefits for solar collectors installed in Bangalore  

Science Journals Connector (OSTI)

The amount of energy that can be extracted from the solar radiation by solar collectors or photovoltaic systems depends mainly on the installation angle of the collector (tilt angle) and the tracking method used to follow the Sun. In this paper the optimum tilt angle for Bangalore ( 12 ° 5 8 ? ) has been calculated under various tracking conditions. For a fixed tilt angle collector facing south the optimum tilt angle is estimated to be between 15° and 17° and is not very sensitive to radiation data type. Fixed tilt angle collectors and collectors tilted on a monthly basis produced only marginal benefit ( horizontal orientation. However for continuously tracked systems benefits are as high as 35%. At least three sets of solar radiation data are available for Bangalore from different sources. It has been shown that they have considerable differences in their direct and diffuse content. All these data have been used to quantify tracking benefits to understand their sensitivity. Limited amount of available in-house data indicates higher diffuse fraction in solar radiation than predicted by historic data and satellite models. Hence the benefits due to tilting are reduced.

Pascal Fahl; Ganapathisubbu S

2011-01-01T23:59:59.000Z

75

Experimental study of integrated collector storage solar water heaters  

Science Journals Connector (OSTI)

Three Integrated Collector Storage Solar Water Heaters (ICSSWH) have been designed, constructed and experimentally studied in comparison to a Flat Plate Thermosiphonic Unit (FPTU). Each of the ICS experimental models consists of one cylindrical tank horizontally mounted in a stationary symmetrical Compound Parabolic Concentrating (CPC) reflector trough. The main objective is the design and construction of low cost solar water heaters with improved thermal performance and lower possible depths. The experimental models can be mounted on horizontal as well as on inclined roofs by adopting the lowest possible depth. The results show that these solar devices perform more than effectively all year long. This could contribute significantly on the development of ICS type solar water heaters.

M. Souliotis; D. Chemisana; Y.G. Caouris; Y. Tripanagnostopoulos

2013-01-01T23:59:59.000Z

76

Performance simulation of solar collectors made of concrete with embedded conduit lattice  

SciTech Connect

A solar collector made of a lattice of fluid conduits embedded within a thin concrete slab is investigated. Such a configuration can be constructed to withstand some mechanical strain by reinforcing the concrete with glass fibers. This collector can be integrated within construction elements of buildings and therefore offers means for low-cost solar energy collection. The geometry of such a collector as well as its characteristic parameters are different from the conventional flat-plate thin-fin collector. Its performance cannot therefore be accurately predicted by assuming a thin-fin behavior. It requires a different and somewhat more involved thermal analysis. In the present analysis, a numerical solution of a two-dimensional cross-sectional slice is expanded in the longitudinal direction by superpositioning such slices in tandem. A parametric study of the relative influence of various operational, geometrical and material parameters is presented. The study provides the tools for a feasibility study of such collectors. Transient characteristics of the collector's dynamic response during a typical summer day with continuous or intermittent radiation are also presented.

Sokolov, M.; Reshef, M. (Tel-Aviv Univ., Ramat-Aviv (Israel))

1992-01-01T23:59:59.000Z

77

Optimization of solar flat collector inclination  

Science Journals Connector (OSTI)

Solar collectors need to be inclined at the optimum angle to maximize the receiving energy. In spite of many theoretical and experimental investigations on optimization of solar collector inclination, there is an inconsistency in presented results. In this paper, solar global radiation on a horizontal surface was estimated using a mathematical model and the results were compared with the recorded data from the Zahedan city meteorological station. Total received solar energy by a flat inclined collector was determined in a certain day, and searching for the angle which has the maximum incident energy was the general procedure in determination of daily optimum tilt angle. In case of operational limitation for daily tilt adjustment, this procedure is repeated for other specific period of time and monthly, seasonal, semi-annual and annual optimum tilt angles were determined. A MATLAB-based code is used to calculate the daily optimum tilt angle. The results were in good agreement with the obtained data of a new constructed device. Finally, in the case of stationary devices, some recommendations were presented with respect to their typical application.

Hamid Moghadam; Farshad Farshchi Tabrizi; Ashkan Zolfaghari Sharak

2011-01-01T23:59:59.000Z

78

Ultracapacitor current collector  

DOE Patents (OSTI)

An ultracapacitor having two solid, nonporous current collectors, two porous electrodes separating the collectors, a porous separator between the electrodes and an electrolyte occupying the pores in the electrodes and separator. At least one of the current collectors comprises a conductive metal substrate coated with a metal nitride, carbide or boride coating.

Jerabek, Elihu Calfin (Glenmont, NY); Mikkor, Mati (Ann Arbor, MI)

2001-10-16T23:59:59.000Z

79

Linear concentrating solar collector  

SciTech Connect

The present invention relates to a segment of a linear concentrating solar collector which includes two plates distanced from each other and extending parallel to each other; a member connects the plates to each other and holes are bored in each of the plates in a parallel manner along a parabolic curve. A member passes through the holes each holding a small strip made of a reflecting material all strips together forming a parabolic surface. The invention relates also to a collector comprising at least two of each segments and an absorber extending along the focus line of the entire collector. The collector is advantageously provided with horizontal and/or vertical members which ascertains that the collector can follow the position of the sun.

Aharon, N. B.

1985-08-06T23:59:59.000Z

80

Development of a low-cost black-liquid solar collector, Phase II. Second semi-annual report, March 1, 1980-August 31, 1980  

SciTech Connect

Battelle's Columbus Laboratories (BCL) is continuing its research effort to develop an efficient, low-temperature, low-cost, flat-plate black-liquid solar collector. The research efforts during this second 6-month period of Phase II have been directed toward (1) evaluating the long-term durability of various plastic materials and solar collector designs, (2) obtaining sufficient outdoor performance data to design a full-scale demonstration of a black-liquid solar collector for a commercial application, (3) working closely with a company willing to commercialize black liquid plastic collectors, and (4) incorporating improved black liquids with the identified plastic collector designs. Besides conducting indoor weathering tests of various plastic materials, two outdoor automated test facilities have been operated. One unit has been in use since February 1980 at Battelle in Columbus, Ohio, and the other unit began operation in May 1980 at Ramada Energy Systems, Inc., a collector manufacturing company near Phoenix, Arizona. Since Ramada Energy Systems has been working with extruded polycarbonate panels, Battelle has been working to date with extruded acrylic panel designs. Other potential plastics for solar collectors are being evaluated by exposure testing.

Landstrom, D.K.; Talbert, S.G.; McGinniss, V.D.

1980-09-30T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Internal absorber solar collector  

DOE Patents (OSTI)

Thin solar collecting panels are described made from arrays of small rod collectors consisting of a refracting dielectric rod lens with an absorber imbedded within it and a reflecting mirror coated on the back side of the dielectric rod. Non-tracking collector panels on vertical walls or roof tops receive approximately 90% of solar radiation within an acceptance zone 60.degree. in elevation angle by 120.degree. or more in the azimuth sectors with a collector concentration ratio of approximately 3.0. Miniaturized construction of the circular dielectric rods with internal absorbers reduces the weight per area of glass, plastic and metal used in the collector panels. No external parts or insulation are needed as heat losses are low due to partial vacuum or low conductivity gas surrounding heated portions of the collector. The miniature internal absorbers are generally made of solid copper with black selective surface and the collected solar heat is extracted at the collector ends by thermal conductivity along the absorber rods. Heat is removed from end fittings by use of liquid circulants. Several alternate constructions are provided for simplifying collector panel fabrication and for preventing the thermal expansion and contraction of the heated absorber or circulant tubes from damaging vacuum seals. In a modified version of the internal absorber collector, oil with temperature dependent viscosity is pumped through a segmented absorber which is now composed of closely spaced insulated metal tubes. In this way the circulant is automatically diverted through heated portions of the absorber giving higher collector concentration ratios than theoretically possible for an unsegmented absorber.

Sletten, Carlyle J. (106 Nagog Hill Rd., Acton, MA 01720); Herskovitz, Sheldon B. (88 Hammond St., Acton, MA 01720); Holt, F. S. (46 Emerson Rd., Winchester, MA 01890); Sletten, E. J. (Chestnut Hill Rd. R.F.D. Rte. #4, Amherst, NH 03031)

1981-01-01T23:59:59.000Z

82

Flow distribution in a solar collector panel with horizontally inclined absorber strips  

Science Journals Connector (OSTI)

The objective of this work is to theoretically and experimentally investigate the flow and temperature distribution in a solar collector panel with an absorber consisting of horizontally inclined strips. Fluid flow and heat transfer in the collector panel are studied by means of computational fluid dynamics (CFD) calculations. Further, experimental investigations of a 12.5 m2 solar collector panel with 16 parallel connected horizontal fins are carried out. The flow distribution through the absorber is evaluated by means of temperature measurements on the backside of the absorber tubes. The measured temperatures are compared to the temperatures determined by the CFD model and there is a good similarity between the measured and calculated results. Calculations with the CFD model elucidate the flow and temperature distribution in the collector. The influences of different operating conditions such as flow rate, properties of solar collector fluid, solar collector fluid inlet temperature and collector tilt angle are shown. The flow distribution through the absorber fins is uniform if high flow rates are used. By decreased flow rate and decreased content of glycol in the glycol/water mixture used as solar collector fluid, and by increased collector tilt and inlet temperature, the flow distribution gets worse resulting in an increased risk of boiling in the upper part of the collector panel.

Jianhua Fan; Louise Jivan Shah; Simon Furbo

2007-01-01T23:59:59.000Z

83

Numerical study of natural convection in fully open tilted cavities  

SciTech Connect

A numerical simulation of two-dimensional laminar natural convection in a fully open tilted square cavity with an isothermally heated back wall is conducted. The remaining two walls of the cavity are adiabatic. Steady-state solutions are presented for Grashof numbers between 10{sup 2} and 10{sup 5} and for tilt angles ranging from {minus}60{degree} to 90{degree} (where 90{degree} represents a cavity with the opening facing down). The fluid properties are assumed to be constant except for the density variation with temperature that gives rise to the buoyancy forces, which is treated by the Boussinesq approximation. The fluid concerned is air with Prandtl number fixed at 0.71. The governing equations are expressed in a normalized primitive variables formulation. Numerical predictions of the velocity and temperature fields are obtained using the finite-volume-based power law (SIMPLER: Semi-Implicit Method for Pressure-Linked Equations Revised) algorithm. For a vertical open cavity ({alpha} = 0{degree}), the algorithm generated results that were in good agreement with those previously published. Flow patterns and isotherms are shown in order to give a better understanding of the heat transfer and flow mechanisms inside the cavity. Effects of the controlling parameters-Grashof number and tilt angle-on the heat transfer (average Nusselt number) are presented and analyzed. The results also revealed that the open-cavity Nusselt number approaches the flat-plate solution when either Grashof number or tilt angle increases. In addition, a correlation of the Nusselt number in terms of the Grashof number and tilt angle is developed and presented; a comparison is made with available data from other literature.

Elsayed, M.M.; Al-Najem, N.M.; El-Refaee, M.M.; Noor, A.A.

1999-09-01T23:59:59.000Z

84

Solar swimming pool heating -- A copper collector after 26 years  

SciTech Connect

This paper is a progress report and a technology overview for a do-it-yourself solar swimming pool heater built by the author. Since March 1973 the heater has operated successfully day in day out for over 26 years, as a simple component in the pool circulation system, for three successive homeowners. The heater project was sponsored by the Copper Development Association (CDA), and used a copper flat plate collector design mounted on a small building, which provided both the roofing and the solar collection function. The heater was built in Pasadena, California, at 34.2 degrees north latitude and 118.2 degrees west longitude. A do-it-yourself manual was written so others could build such heaters, and about 100,000 copies of this manual have been distributed. The manual has helped many to get a better understanding of solar energy, has allowed many around the world to build similar swimming pool heater, and caused this author to get into the solar energy field.

Winter, F. de

1999-07-01T23:59:59.000Z

85

Estimation of 5-min solar global irradiation on tilted planes by ANN method in Bouzareah, Algeria  

E-Print Network (OSTI)

], three main reasons make it impossible to develop a simple model for converting horizontal global solar surface The solar radiation arriving on a tilted collector has, most of the time, a beam component (nilEstimation of 5-min solar global irradiation on tilted planes by ANN method in Bouzareah, Algeria K

Paris-Sud XI, Université de

86

Solar collector overheating protection  

Science Journals Connector (OSTI)

Prismatic structures in a thermal solar collector are used as overheating protection. Such structures reflect incoming light efficiently back whenever less thermal power is extracted from the solar collector. Maximum thermal power is generated when the prismatic structure is surrounded by a switching fluid with an index of refraction comparable to that of the prismatic structure. Thermal heat can be harvested via extra fluid channels in the solar absorber or directly via the switching fluid near the prisms. The light reducing effect of prismatic structures is demonstrated for a typical day and a season cycle of the Earth around the Sun. The switchability and the light reducing effect are also demonstrated in a prototype solar collector.

M. Slaman; R. Griessen

2009-01-01T23:59:59.000Z

87

Electrochemically Stable Cathode Current Collectors for Rechargeable...  

NLE Websites -- All DOE Office Websites (Extended Search)

Stable Cathode Current Collectors for Rechargeable Magnesium Batteries . Electrochemically Stable Cathode Current Collectors for Rechargeable Magnesium Batteries . Abstract:...

88

CALIFORNIA SOLAR DATA MANUAL  

E-Print Network (OSTI)

horizontal. Knowing this quantity is important since most solar applications that employ flat-plate collectors

Berdahl, P.

2010-01-01T23:59:59.000Z

89

Self-aligning solar collector  

SciTech Connect

A self-aligning solar energy collector which maintains its attitude facing the sun during the sun's daily and seasonal changes. Tension cables hold the collector in position, and are positioned so as to be out of equilibrium when off-axis solar radiation heat one cable more than another. Self-alignment is in both horizontal and vertical planes. Multiple collectors are also disclosed in a ganged or masterslave relationship.

Vandenberg, L.B.

1982-12-28T23:59:59.000Z

90

Solar collector assembly  

SciTech Connect

Individual collector cells are fitted together in series along a heat transfer medium tube. The cells have a cylindrical housing with mating interconnecting flanges at the ends, through which the tube also passes. The flanges may have sealing gaskets. The housing has a transparent front side and a reflective back side. The cross-sectional configuration of the front is arcuate, while that of the back is parabolic. The cells are fixed with respect to the tube axis, but can rotate about it to follow the sun. Parallel cell rows can be interconnected to rotate together. Interconnected, articulated cell rows are disclosed as a removable cover for a swimming pool.

Bogatzki, H.

1980-09-16T23:59:59.000Z

91

Integrated solar collector  

DOE Patents (OSTI)

A solar collector having a copper panel in a contiguous space relationship with a condenser-evaporator heat exchanger located under the panel, the panel having a honeycomb-like structure on its interior defining individual cells which are filled with zeolite loaded, in its adsorbed condition, with 18 to 20% by weight of water. The interior of the panel and heat exchanger are maintained at subatmospheric pressure of about 0.1 to 1 psia. The panel and heat exchanger are insulated on their lateral sides and bottoms and on the top of the heat exchange. The panel has a black coating on its top which is exposed to and absorbs solar energy. Surrounding the insulation (which supports the panel) is an extruded aluminum framework which supports a pair of spaced-apart glass panels above the solar panel. Water in conduits from a system for heating or cooling or both is connected to flow into an inlet and discharge from outlet of a finned coil received within the heat exchanger. The collector panel provides heat during the day through desorption and condensing of water vapor from the heated solar panel in the heat exchanger and cools at night by the re-adsorption of the water vapor from the heat exchanger which lowers the absolute pressure within the system and cools the heat exchange coils by evaporation.

Tchernev, Dimiter I. (9 Woodman Rd., Chestnut Hill, MA 02167)

1985-01-01T23:59:59.000Z

92

OpenEI - solar radiation  

Open Energy Info (EERE)

monthly and monthly and annual average latitude tilt GIS data at 40km resolution for Mexico, Central America, and the Caribbean Islands from NREL http://en.openei.org/datasets/node/500 (Abstract):  Monthly Average Solar Resource for flat-plate collectors tilted at latitude, for Mexico, Central America,
and the Caribbean Islands. (Purpose):  Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented due south at an angle from horizontal equal to the latitude of the

93

TILT | OpenEI  

Open Energy Info (EERE)

TILT TILT Dataset Summary Description Developed by NREL and the U.S. Trade and Development Agency, this geographic toolkit that allows users to relate the renewable energy resource (solar and wind) data to other geographic data, such as land use, protected areas, elevation, etc. The GsT was completely redesigned and re-released in November 2010 to provide a more modern, easier-to-use interface with considerably faster analytical querying capabilities. The revised version of the Geospatial Toolkit for Turkey is available using the following link: http://www.nrel.gov/international/downloads/gst_turkey.exe Source GeoModel Date Released March 31st, 2009 (5 years ago) Date Updated July 06th, 2012 (2 years ago) Keywords DNI GeoModel GHI GIS GsT NREL solar SWERA TILT

94

Biobriefcase aerosol collector  

DOE Patents (OSTI)

A system for sampling air and collecting particles entrained in the air that potentially include bioagents. The system comprises providing a receiving surface, directing a liquid to the receiving surface and producing a liquid surface. Collecting samples of the air and directing the samples of air so that the samples of air with particles entrained in the air impact the liquid surface. The particles potentially including bioagents become captured in the liquid. The air with particles entrained in the air impacts the liquid surface with sufficient velocity to entrain the particles into the liquid but cause minor turbulence. The liquid surface has a surface tension and the collector samples the air and directs the air to the liquid surface so that the air with particles entrained in the air impacts the liquid surface with sufficient velocity to entrain the particles into the liquid, but cause minor turbulence on the surface resulting in insignificant evaporation of the liquid.

Bell, Perry M. (Tracy, CA); Christian, Allen T. (Madison, WI); Bailey, Christopher G. (Pleasanton, CA); Willis, Ladona (Manteca, CA); Masquelier, Donald A. (Tracy, CA); Nasarabadi, Shanavaz L. (Livermore, CA)

2009-09-22T23:59:59.000Z

95

ADVANCED HYBRID PARTICULATE COLLECTOR  

SciTech Connect

A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the US Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a manner that has not been done before. The AHPC concept consists of a combination of fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emission with conventional ESPs, and it solves the problem of reentrainment and collection of dust in conventional baghouses. The AHPC is currently being tested at the 2.7-MW scale at the Big Stone power station.

Stanley Miller; Rich Gebert; William Swanson

1999-11-01T23:59:59.000Z

96

Performance evaluation of the site built trickle solar collector system to heat swimming pool  

SciTech Connect

This report discusses the analysis and field experiment conducted to determine the thermal performance of a particular trickle water collector design. Specific areas examined include the effect of the aspect ratio, flow rate and tilt angle on the collector performance. The exact solar radiation on the sinusoidal absorber plate has to be theoretically calculated. The influence of various design parameters such as corrugation height and width, distance between cover and absorber, tilt angle, and flow rate on the performance is rather small. For a small temperature increase between fluid inlet and outlet the agreement between experimental and theoretical results appears to be reasonable. However, for the higher fluid inlet temperature, and for larger temperature increase, the actual collector efficiency deviates significantly to indicate the necessity of a correction factor such as fogging on the cover plate to the theoretical consideration.

Lee, J.H.; Park, W.H.; Park, K.S.

1985-01-01T23:59:59.000Z

97

Shenandoah parabolic dish solar collector  

SciTech Connect

The objectives of the Shenandoah, Georgia, Solar Total Energy System are to design, construct, test, and operate a solar energy system to obtain experience with large-scale hardware systems for future applications. This report describes the initial design and testing activities conducted to select and develop a collector that would serve the need of such a solar total energy system. The parabolic dish was selected as the collector most likely to maximize energy collection as required by this specific site. The fabrication, testing, and installation of the parabolic dish collector incorporating improvements identified during the development testing phase are described.

Kinoshita, G.S.

1985-01-01T23:59:59.000Z

98

Radiant energy collector. [Patent application  

DOE Patents (OSTI)

A cylindrical radiant energy collector is provided which includes a reflector spaced apart from an energy absorber. The reflector is of a particular shape which ideally eliminates gap losses.

McIntire, W.R.

1980-02-14T23:59:59.000Z

99

Solar heat collector  

SciTech Connect

An evacuated double-tubing solar heat collector is described comprising: an inner tube having an open end and a closed end; a selective absorption film applied over an exterior surface of the inner tube; an outer tube having an open end and a closed end; the inner tube being constructed to be received within the outer tube; and a substantially continuous annular coil spring ring being substantially found in cross section and of a predetermined thickness. The coil spring ring is disposed between and engages an interior surface of the outer tube and the exterior surface of the inner tube for spacing and resiliently supporting the inner tube relative to the outer tube. The ring is freely rotatably positioned to be moved axially along the length of the inner tube due only to frictional forces exerted on the coil spring. The coil spring ring is positioned on the inner tube at approximately a middle position along the length of the inner tube by being initially positioned on the inner tube adjacent to the closed end thereof and rotated upon itself axially along the inner tube only by frictional engagement with the interior surface of the outer tube as the inner tube is inserted into the open end of the outer tube and moved to a fully inserted position within the outer tube. The open end of the inner tube and the open end of the outer tube are fused to form a junction and hermetically sealed.

Takeuchi, H.; Mikiya, T.

1987-03-17T23:59:59.000Z

100

Collector for thermionic energy converter  

SciTech Connect

An improved collector is provided for a thermionic energy converter. The collector comprises a p-type layer of a semiconductor material formed on an n-type layer of a semiconductor material. The p-n junction is maintained in a forward biased condition. The electron affinity of the exposed surface of the p-type layer is effectively lowered to a low level near zero by the presence of a work function lowering activator. The dissipation of energy during collection is reduced by the passage of electrons through the p-type layer in the metastable conduction band state. A significant portion of the electron current remains at the potential of the fermi level of the n-type layer rather than dropping to the fermi level of the p-type layer. Less energy is therefore dissipated as heat and a higher net power output is delivered from a thermionic energy converter incorporating the collector.

Bell, R.L.

1981-07-21T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Thin film solar energy collector  

DOE Patents (OSTI)

A multi-layer solar energy collector of improved stability comprising: (1) a substrate of quartz, silicate glass, stainless steel or aluminum-containing ferritic alloy; (2) a solar absorptive layer comprising silver, copper oxide, rhodium/rhodium oxide and 0-15% by weight of platinum; (3) an interlayer comprising silver or silver/platinum; and (4) an optional external anti-reflective coating, plus a method for preparing a thermally stable multi-layered solar collector, in which the absorptive layer is undercoated with a thin film of silver or silver/platinum to obtain an improved conductor-dielectric tandem.

Aykan, Kamran (Monmouth Beach, NJ); Farrauto, Robert J. (Westfield, NJ); Jefferson, Clinton F. (Millburn, NJ); Lanam, Richard D. (Westfield, NJ)

1983-11-22T23:59:59.000Z

102

Optimization of angle of inclination of the hybrid photovoltaic-thermal solar collector using particle swarm optimization algorithm  

Science Journals Connector (OSTI)

In this paper a mathematical model is used to determine the solar radiation incident on an inclined surface and the optimum slope angles for each month season and year are calculated for solar hybrid collectors. We recommend on how the collected energy can be increased by varying the tilt angle. First we esteem the global solar radiation on a horizontal surface of a thermal photovoltaic hybrid collector (PVT) for a clear sky. The data set of the solar radiation at Ghardaïa (Algeria) measured during 2013 was used to analyze the models of global solar radiation estimation. The models of performance are evaluated by using the coefficient of correlation (R2) the absolute average error skew (mean absolute error MABE) average quadratic error (mean square error RMSE) the percentage of the average error (MPE) and the percentage of average absolute error. Then the anisotropic and isotropic models that provide the most accurate estimation of the total solar radiation has been used to determine the optimum collector slope. Particle swarm optimization method was applied to obtain the tilt angle setting of the tilt angle of PVT collector. The objective was to improve the efficiency of PVT collector. The results show that these models used are very well designed. The coefficient of correlation (R2) varies from 0. 90 to 0. 99. For the percentage of errors of prediction (MABE and RMSE) lowered by 0.1 it is observed also that the angle of inclination of PVT collector takes different values during the year and that the collector received more solar energy compared to collector without optimal angle.

2014-01-01T23:59:59.000Z

103

The design of a pre-collector for cyclone collectors  

E-Print Network (OSTI)

Tests were conducted on small laboratory scale ID-3D and 2D-2D cyclones to demonstrate the reduction in emission concentrations resulting when a pre-cyclone collector is used to collect large trash particles prior to cyclone fine dust collection...

Mihalski, Karl Duane

2012-06-07T23:59:59.000Z

104

SOLAR COLLECTORS, SELECTIVE SURFACES, AND HEAT ENGINES  

Science Journals Connector (OSTI)

SOLAR COLLECTORS, SELECTIVE SURFACES, AND HEAT...Tabor NATIONAL PHYSICAL LABORATORY OF ISRAEL SOLAR COLLECTORS, SELECTIVE SURFACES, AND HEAT...I should be working on the conversion of solar energy to power by thermal means instead...

H. Tabor

1961-01-01T23:59:59.000Z

105

solar radiation | OpenEI  

Open Energy Info (EERE)

radiation radiation Dataset Summary Description (Abstract): Monthly Average Solar Resource for flat-plate collectors tilted at latitude, for Mexico, Central America, and the Caribbean Islands. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented due south at an angle from horizontal equal to the latitude of the collector location. Source NREL Date Released January 31st, 2004 (10 years ago) Date Updated October 30th, 2007 (7 years ago) Keywords atmospheric water vapor Carribean Central America GEF. latitude tilt GIS Mexico NREL solar solar radiation SWERA TILT UNEP Data application/zip icon Download Shapefile (zip, 241.3 KiB)

106

Solar energy collector with collapsible supporting structure  

SciTech Connect

A solar energy collector formed of a black plastic material in a rigid, unitary, one-piece self-supporting construction. The collector is formed with inlet and outlet manifolds and a multiplicity of fluid flow passages extending therebetween. Each passage is provided with at least one flow restriction to provide a uniform distribution of flow through all passages. A series of such collectors are connected to form an array incorporated in a multipurpose, collapsible structure for heating swimming pool water.

Goodman, R.D.; Krueger, W.F.; Shaw, A.R.

1980-06-10T23:59:59.000Z

107

Tubular solid oxide fuel cell current collector  

DOE Patents (OSTI)

An internal current collector for use inside a tubular solid oxide fuel cell (TSOFC) electrode comprises a tubular coil spring disposed concentrically within a TSOFC electrode and in firm uniform tangential electrical contact with the electrode inner surface. The current collector maximizes the contact area between the current collector and the electrode. The current collector is made of a metal that is electrically conductive and able to survive under the operational conditions of the fuel cell, i.e., the cathode in air, and the anode in fuel such as hydrogen, CO, CO.sub.2, H.sub.2O or H.sub.2S.

Bischoff, Brian L. (Knoxville, TN); Sutton, Theodore G. (Kingston, TN); Armstrong, Timothy R. (Clinton, TN)

2010-07-20T23:59:59.000Z

108

Collectors R&D for CSP Systems  

Energy.gov (U.S. Department of Energy (DOE))

Collectors—whether for trough, tower (heliostat), linear Fresnel or dish systems—comprise up to 40% of the total system costs for concentrating solar power (CSP) technologies. The DOE SunShot CSP Program seeks to dramatically reduce the cost of the collector field while improving optical accuracy and ensuring durability. The SunShot Initiative funds research and development (R&D) on collector systems and related aspects within the industry, national laboratories and universities to achieve the following technical targets of collector subsystems toward the SunShot goals.

109

A solar concentrating photovoltaic/thermal collector .  

E-Print Network (OSTI)

??This thesis discusses aspects of a novel solar concentrating photovoltaic / thermal (PV/T) collector that has been designed to produce both electricity and hot water.… (more)

Coventry, Joseph S

2008-01-01T23:59:59.000Z

110

Automated solar collector installation design  

DOE Patents (OSTI)

Embodiments may include systems and methods to create and edit a representation of a worksite, to create various data objects, to classify such objects as various types of pre-defined "features" with attendant properties and layout constraints. As part of or in addition to classification, an embodiment may include systems and methods to create, associate, and edit intrinsic and extrinsic properties to these objects. A design engine may apply of design rules to the features described above to generate one or more solar collectors installation design alternatives, including generation of on-screen and/or paper representations of the physical layout or arrangement of the one or more design alternatives.

Wayne, Gary; Frumkin, Alexander; Zaydman, Michael; Lehman, Scott; Brenner, Jules

2014-08-26T23:59:59.000Z

111

Development of an Advanced, Low-Cost parabolic Trough Collector...  

Office of Environmental Management (EM)

Development of an Advanced, Low-Cost parabolic Trough Collector for Baseload Operation Development of an Advanced, Low-Cost parabolic Trough Collector for Baseload Operation This...

112

Project Profile: Next-Generation Parabolic Trough Collectors...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Trough Collectors and Components for CSP Applications Project Profile: Next-Generation Parabolic Trough Collectors and Components for CSP Applications Abengoa logo Abengoa...

113

BEAM TILTED CORRELATIONS Frank Vignola  

E-Print Network (OSTI)

from tilted solar radiance. This model will then be used to estimate the performance of a photovoltaic. INTRODUCTION The number and variety of grid-tied photovoltaic (PV) systems being installed is stimulating, wind speed, and other meteorological variables and weather conditions. With the variety of solar cell

Oregon, University of

114

A Modified Efficiency Equation of Solar Collectors  

Science Journals Connector (OSTI)

Abstract This paper describes the derivation of a modified equation for solar collector efficiency that is expressed using the heating load term instead of the inlet fluid temperature term from the currently used linear collector efficiency equation. The parameters in the modified equation are estimated using test data measured for 14 days. In evaluation of the equation's validity, the calculated daily collector efficiency agrees well with the measured daily collector efficiency, with a correlation coefficient of 0.9110. The equation is also be expressed in another form by including the term for the shape of the hot water storage tank in the solar heating system. Collector efficiencies with parametric changes are calculated with the estimated parameters and compared with different global solar irradiance on solar collectors, daily average ambient temperature and heating loads per collector area. It would be necessary to estimate the parameters for better performance of the efficiency equation with more data from long-term system simulations at various operating conditions.

Kyoung-ho Lee; Nam-choon Baek

2014-01-01T23:59:59.000Z

115

Solar collector mounting and support apparatus  

SciTech Connect

A solar collector system is described of the type having a movable surface for receiving solar radiation having improved means for rotatably supporting the movable surface and for rotating the collector surface. A support axle for the collector includes a ball at one end which is carried within a cylindrical sleeve in the solar collector to support the weight of the collector. A torque transmitting arm comprising a flexible flat strip is connected at one end to the axle and at the other end to the collector surface. An improved rotational drive mechanism includes a first sprocket wheel carried on the axle and a second sprocket wheel supported on a support pylon with a drive chain engaging both sprockets. A double acting piston also supported by the pylon is coupled to the chain so that the chain may be driven by a hydraulic control system to rotate the collector surfaces as required. An improved receiver tube support ring is also provided for use with the improved mounting and support apparatus to improve overall efficiency by reducing thermal losses.

Hutchison, J.A.

1981-12-22T23:59:59.000Z

116

Variable g value of transparent façade collectors  

Science Journals Connector (OSTI)

Transparent solar thermal collectors (TSTC) represent a new development. An adequate model is needed to predict their performance. This paper presents a collector model with an advanced calculation of the transmission of diffuse radiation and a connection to the building which allows analysis of the collector gains and of the g value, also called “solar factor”, “solar heat gain coefficient (SHGC)” or “total solar energy transmittance”. The model is implemented as a TRNSYS Type and a coupled simulation between a collector and a room is presented for different façade constructions. Façade areas with glazing and venetian blinds are simulated with a second new TRNSYS Type which introduces high modelling accuracy for façades with solar control systems. An HVAC system is presented together with a first estimate of possible reductions of primary energy. It indicates primary energy savings of about 30% by replacing opaque walls with transparent collectors. The g values prove to depend not only on the irradiation, but also on the operation of the solar collectors and vary e.g. between 0.04 and 0.21. Detailed modelling of active façades like TSTC is therefore essential for accurate predictions of the collector gain, the heating and cooling loads and the thermal comfort.

Christoph Maurer; Tilmann E. Kuhn

2012-01-01T23:59:59.000Z

117

Biomass Producer or Collector Tax Credit (Oregon)  

Energy.gov (U.S. Department of Energy (DOE))

 The Oregon Department of Energy provides a tax credit for agricultural producers or collectors of biomass.  The credit can be used for eligible biomass used to produce biofuel; biomass used in...

118

Next-Generation Solar Collectors for CSP  

Energy.gov (U.S. Department of Energy (DOE))

This fact sheet on Next-Generation Collectors for CSP highlights a solar energy program awarded through the 2012 SunShot Concentrating Solar Power R&D awards. The team is developing new solar collector base technologies for next-generation heliostats used in power tower systems. If successful, this project will result in a 50% reduction in solar field equipment cost and a 30% reduction in field installation cost compared to existing heliostat designs.

119

SunShot Initiative: Low-Cost Solar Thermal Collector  

NLE Websites -- All DOE Office Websites (Extended Search)

Low-Cost Solar Thermal Collector Low-Cost Solar Thermal Collector to someone by E-mail Share SunShot Initiative: Low-Cost Solar Thermal Collector on Facebook Tweet about SunShot Initiative: Low-Cost Solar Thermal Collector on Twitter Bookmark SunShot Initiative: Low-Cost Solar Thermal Collector on Google Bookmark SunShot Initiative: Low-Cost Solar Thermal Collector on Delicious Rank SunShot Initiative: Low-Cost Solar Thermal Collector on Digg Find More places to share SunShot Initiative: Low-Cost Solar Thermal Collector on AddThis.com... Concentrating Solar Power Systems Components Competitive Awards CSP Research & Development Thermal Storage CSP Recovery Act Baseload CSP SunShot Multidisciplinary University Research Initiative CSP Heat Integration for Baseload Renewable Energy Deployment National Laboratory Research & Development

120

U-153: EMC Data Protection Advisor Server and Collector Bugs...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

53: EMC Data Protection Advisor Server and Collector Bugs Let Remote Users Deny Service U-153: EMC Data Protection Advisor Server and Collector Bugs Let Remote Users Deny Service...

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Project Profile: Low-Cost Solar Thermal Collector | Department...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Solar Thermal Collector Project Profile: Low-Cost Solar Thermal Collector SunTrough Energy logo SunTrough, under the Baseload CSP FOA, is developing a new class of solar...

122

Impact of Ageing on Thermal Efficiency of Solar Thermal Collectors  

Science Journals Connector (OSTI)

Today it is common practice to calculate the performance of solar thermal systems or solar collectors based on the results of a thermal performance test carried out with a new solar collector. However, for an int...

Elke Streicher; Stephan Fischer…

2009-01-01T23:59:59.000Z

123

Characteristics of two thermionic converters with oxide collectors  

SciTech Connect

Thermionic converters built with selected metal oxide coatings on their collectors have given enhanced performance at interelectrode spacings greater than 0.25 mm. The capability of such converters to operate efficiently at large interelectrode spacings is of interest for in-core thermionic power systems. Performance data are reported from one converter built with a collector having a coating of molybdenum sublimed in oxygen and a second converter containing an oxidized zirconium collector. The molybdenum oxide collector converter demonstrated enhanced performance.

Smith, E.A.; Huffman, F.N.

1984-08-01T23:59:59.000Z

124

Experimental Study on Optical Properties of the Collector  

Science Journals Connector (OSTI)

Solar collector is one of the most important parts of solar chimney power plant. It plays an important role...

Wang Juan; Zhao Liang; Li Huashan

2009-01-01T23:59:59.000Z

125

Project Profile: Improved Large Aperture Collector Manufacturing  

Energy.gov (U.S. Department of Energy (DOE))

Abengoa Solar, under the Solar Manufacturing Technology (SolarMat) program, will be investigating the use of an automotive-style high-rate fabrication and automated assembly techniques to achieve a substantial reduction in the deployment cost of their new SpaceTube advanced large aperture parabolic trough collector.

126

Large optics inspection, tilting, and washing stand  

DOE Patents (OSTI)

A large optics stand provides a risk free means of safely tilting large optics with ease and a method of safely tilting large optics with ease. The optics are supported in the horizontal position by pads. In the vertical plane the optics are supported by saddles that evenly distribute the optics weight over a large area.

Ayers, Marion Jay (Brentwood, CA); Ayers, Shannon Lee (Brentwood, CA)

2010-08-24T23:59:59.000Z

127

Tilt display demonstration: a display surface with multi-axis tilt & actuation  

Science Journals Connector (OSTI)

This demonstration accompanies a full paper accepted into MobileHCI '12 [1]. We demonstrate a new type of actuatable display, called a Tilt Display, that provides visual feedback combined with multi-axis tilting and vertical actuation. Its ability to ... Keywords: actuated displays, nonplanar surface interaction, physical actuation, tilt displays

Jason Alexander; Andrés Lucero; Sriram Subramanian

2012-09-01T23:59:59.000Z

128

Tilt displays: designing display surfaces with multi-axis tilting and actuation  

Science Journals Connector (OSTI)

We present a new type of actuatable display, called Tilt Displays, that provide visual feedback combined with multi-axis tilting and vertical actuation. Their ability to physically mutate provides users with an additional information channel that facilitates ... Keywords: actuated displays, non-planar surface interaction, physical actuation, tilt displays

Jason Alexander; Andrés Lucero; Sriram Subramanian

2012-09-01T23:59:59.000Z

129

GEF. latitude tilt | OpenEI  

Open Energy Info (EERE)

GEF. latitude tilt GEF. latitude tilt Dataset Summary Description (Abstract): Latitude tilted solar radiation in kWh/m2/day for 1 year organized into cells with 40km x 40km (Purpose): To provide a set of consistent, reliable, verifiable, and accessible global data sets for international and in-country investors and other stakeholders Source INPE (National Institute for Spatial Research) and LABSOLAR (Laboratory of Solar Energy/Federal University of Santa Catarina) - Brazil Date Released August 08th, 2009 (5 years ago) Date Updated August 08th, 2009 (5 years ago) Keywords Brazil GEF. latitude tilt INPE LABSOLAR solar SWERA TILT UNEP Data application/zip icon Download Shapefile (zip, 706.1 KiB) text/csv icon Download Data (csv, 999.1 KiB) Quality Metrics Level of Review Some Review

130

Thermal Efficiency of Solar Collector Made from Thermoplastics  

Science Journals Connector (OSTI)

Abstract Thermoplastics solar collectors have been used to replace a typical metal collector because their mechanical and physical properties make the volume production of lightweight, low cost and corrosion resistance. Effect of thermal conductivity and collector area was observed for four type of themoplastics based i.e PVC-B (PVC: Polyvinyl Chloride-Blue), PB (PB: Polybutene), PP-R (PP-R: Polypropylene Random Copolymer) and PVC-CB: (Polyvinyl Chloride-Carbon Black). The collector area of 2 m2 were prepared as for solar collector. The position of collector panel to south orientation and angle of 140 to the horizontal, which was the collector slope obtaining highest annual efficiency in Thailand, were implemented. Data was collected by data logger from 9.00-16.00 am throughout the day in which temperature reached a sufficient level according to standard test method of ASHRAE 93 77. The mass flow rate of water in collector was 0.02 (kg.s-1). The results of the differing thermal conductivity materials have indicated that there is no different of the materials on collector thermal efficiency. The collector efficiency was depends on the areas of the panel. This suggestion that one material should not only be chosen over another in term of its ability to transfer heat to the liquid within the panel but also collector area.

Warunee Ariyawiriyanan; Tawatchai Meekaew; Manop Yamphang; Pongpitch Tuenpusa; Jakrawan Boonwan; Nukul Euaphantasate; Pongphisanu Muangchareon; Supachat Chungpaibulpatana

2013-01-01T23:59:59.000Z

131

NREL: Concentrating Solar Power Research - Collector R&D  

NLE Websites -- All DOE Office Websites (Extended Search)

Collector R&D Collector R&D Featured Resource Learn more about NREL's capabilities in collector/receiver characterization. Collector research at NREL focuses on developing and testing the next generation of concentrating solar power (CSP) collectors that reduce delivered electricity costs by 50%. NREL's work involves improved reflector development, optical model development, optical measurement techniques, testing standards, and reliability assessments. NREL also works to upgrade and adapt optical tools to enhance laboratory testing capabilities. CSP collectors capture the sun's energy with mirrors that reflect and focus the sunlight onto a receiver, creating the heat that is used to generate electricity. Opportunities and Potential Impact Collectors-whether for parabolic trough, power tower, or dish

132

A Self-Biasing Pulsed Depressed Collector  

SciTech Connect

Depressed collectors have been utilized successfully for many years to improve the electrical efficiency of vacuum electron devices. Increasingly, pulsed, high-peak power accelerator applications are placing a premium on electrical efficiency. As RF systems are responsible for a large percentage of the overall energy usage at accelerator laboratories, methods to improve upon the state-of-the-art in pulsed high-power sources are desired. This paper presents a technique for self-biasing the stages in a multistage depressed collector. With this technique, the energy lost during the rise and fall times of the pulse can be recovered, separate power supplies are not needed, and existing modulators can be retrofitted. Calculations show that significant cost savings can be realized with the implementation of this device in high-power systems. In this paper, the technique is described along with experimental demonstration. (auth)

Kemp, Mark A.; Jensen, Aaron; Neilson, Jeff; /SLAC

2014-05-29T23:59:59.000Z

133

Solar collector for fluid heating system  

SciTech Connect

A solar collector for use in either an upfeed forced hot water heating system or a downfeed system features a pair of serpentine coils arranged in opposing flow relationship within a shallow insulated collector housing having a sealed glass closure panel. The two serpentine coils lie in spaced parallel planes within the housing, and the two coils are offset laterally so that their individual longitudinal loops overlap laterally by approximately one-half the width of each loop. The flow of heated fluid in each serpentine coil is controlled independently of the other coil by a temperature-responsive modulating valve connected in each coil close to the outlet end thereof within the housing. Efficiency of operation and practicality and economy of construction are featured.

Wilson, D.C.

1980-09-30T23:59:59.000Z

134

NETL: Control Technology: Advanced Hybrid Particulate Collector  

NLE Websites -- All DOE Office Websites (Extended Search)

Advanced Hybrid Particulate Collector Advanced Hybrid Particulate Collector Under DOE-NETL sponsorship, the University of North Dakota, Energy and Environmental Research Center (UND-EERC) has developed a new concept in particulate control, called an advanced hybrid particulate collector (AHPC). In addition to DOE and the EERC, the project team includes W.L. Gore & Associates, Inc., Allied Environmental Technologies, Inc., and the Otter Tail Power Company. The AHPC utilizes both electrostatic collection and filtration in a unique geometric configuration that achieves ultrahigh particle collection with much less collection area than conventional particulate control devices. The primary technologies for state-of-the-art particulate control are fabric filters (baghouses) and electrostatic precipitators (ESPs). A major limitation of ESPs is that the fractional penetration of 0.1- to 1.0-µm particles is typically at least an order of magnitude greater than for 10-µm particles, so a situation exists where the particles that are of greatest health concern are collected with the lowest efficiency. Fabric filters are currently considered to be the best available control technology for fine particles, but emissions are dependent on ash properties and typically increase if the air-to-cloth (A/C) ratio is increased. In addition, many fabrics cannot withstand the rigors of high-SO2 flue gases, which are typical for bituminous fuels. Fabric filters may also have problems with bag cleanability and high pressure drop, which has resulted in conservatively designed, large, costly baghouses.

135

Thin film absorber for a solar collector  

DOE Patents (OSTI)

This invention pertains to energy absorbers for solar collectors, and more particularly to high performance thin film absorbers. The solar collectors comprising the absorber of this invention overcome several problems seen in current systems, such as excessive hardware, high cost and unreliability. In the preferred form, the apparatus features a substantially rigid planar frame with a thin film window bonded to one planar side of the frame. An absorber in accordance with the present invention is comprised of two thin film layers that are sealed perimetrically. In a preferred embodiment, thin film layers are formed from a metal/plastic laminate. The layers define a fluid-tight planar envelope of large surface area to volume through which a heat transfer fluid flows. The absorber is bonded to the other planar side of the frame. The thin film construction of the absorber assures substantially full envelope wetting and thus good efficiency. The window and absorber films stress the frame adding to the overall strength of the collector.

Wilhelm, William G. (Cutchogue, NY)

1985-01-01T23:59:59.000Z

136

Simple solar spectral model for direct and diffuse irradiance on horizontal and tilted planes at the earth's surface for cloudless atmospheres  

SciTech Connect

A new, simple model for calculating clear-sky direct and diffuse spectral irradiance on horizontal and tilted surfaces is presented. The model is based on previously reported simple algorithms and on comparisons with rigorous radiative transfer calculations and limited outdoor measurements. Equations for direct normal irradiance are outlined; and include: Raleigh scattering; aerosol scattering and absorption; water vapor absorption; and ozone and uniformly mixed gas absorption. Inputs to the model include solar zenith angle, collector tilt angle, atmospheric turbidity, amount of ozone and precipitable water vapor, surface pressure, and ground albedo. The model calculates terrestrial spectra from 0.3 to 4.0 ..mu..m with approximately 10 nm resolution. A major goal of this work is to provide researchers with the capability to calculate spectral irradiance for different atmospheric conditions and different collector geometries using microcomputers. A listing of the computer program is provided.

Bird, R.; Riordan, C.

1984-12-01T23:59:59.000Z

137

SIMULATION OF THE THERMAL INTERACTION BETWEEN A BUILDING INTEGRATED PHOTOVOLTAIC COLLECTOR AND AN AIR-  

E-Print Network (OSTI)

SIMULATION OF THE THERMAL INTERACTION BETWEEN A BUILDING INTEGRATED PHOTOVOLTAIC COLLECTOR simultaneously equipped with air-source heat pumps and photovoltaic collectors is constantly increasing. In addition to electricity, the photovoltaic collector produces heat which can be used to increase

Boyer, Edmond

138

Connectable solar air collectors Solar Energy Centre Denmark  

E-Print Network (OSTI)

Connectable solar air collectors Solar Energy Centre Denmark Danish Technological Institute SEC-R-22 #12;Connectable solar air collectors Søren �stergaard Jensen Miroslav Bosanac Solar Energy Centre Søren �stergaard Jensen and Miroslav Bosanac Solar Energy Centre, Danish Technological Institute

139

A solar concentrating photovoltaic / thermal collector J.S. Coventry  

E-Print Network (OSTI)

A solar concentrating photovoltaic / thermal collector J.S. Coventry Centre for Sustainable Energy solar concentrating photovoltaic / thermal collector Coventry "Photovoltaic and Wind Power for Urban of both photovoltaic and solar thermal power generation. Some of the recent projects in Australia

140

Department of Electrical Engineering Spring 2011 Glass Block Solar Collector  

E-Print Network (OSTI)

to the sponsor. The collector incorporated a solar panel that charged a battery unit. The battery poweredPENNSTATE Department of Electrical Engineering Spring 2011 Glass Block Solar Collector Overview Pittsburgh Corning, a leading manufacturer of architectural glass blocks, wanted to incorporate a solar

Demirel, Melik C.

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Test results, Industrial Solar Technology parabolic trough solar collector  

SciTech Connect

Sandia National Laboratories and Industrial Solar Technology are cost-sharing development of advanced parabolic trough technology. As part of this effort, several configurations of an IST solar collector were tested to determine the collector efficiency and thermal losses with black chrome and black nickel receiver selective coatings, combined with aluminized film and silver film reflectors, using standard Pyrex{reg_sign} and anti-reflective coated Pyrex{reg_sign} glass receiver envelopes. The development effort has been successful, producing an advanced collector with 77% optical efficiency, using silver-film reflectors, a black nickel receiver coating, and a solgel anti-reflective glass receiver envelope. For each receiver configuration, performance equations were empirically derived relating collector efficiency and thermal losses to the operating temperature. Finally, equations were derived showing collector performance as a function of input insolation value, incident angle, and operating temperature.

Dudley, V.E. [EG and G MSI, Albuquerque, NM (United States); Evans, L.R.; Matthews, C.W. [Sandia National Labs., Albuquerque, NM (United States)

1995-11-01T23:59:59.000Z

142

Solar energy Part II—The greenhouse effect  

Science Journals Connector (OSTI)

The performance of flat plate collectors is discussed among the topics considered are heat gain and loss and overall efficiency.(AIP)

Matthew Young

1976-01-01T23:59:59.000Z

143

Experimental control of the spheromak tilting instability  

Science Journals Connector (OSTI)

The magnetohydrodynamic (MHD) tilting instability of the spheromak configuration has been experimentally investigated by recording the time evolution of the magnetic field with small magnetic probes. Passive coil systems such as the figure?eight and saddle coils have been proven experimentally effective against this instability.

C. Munson; A. Janos; F. Wysocki; M. Yamada

1985-01-01T23:59:59.000Z

144

Stabilization of the spheromak tilt instability  

Science Journals Connector (OSTI)

A stability criterion for the tilt mode of a spheromak?ion ring hybrid configuration has been developed for the case where the ring current is small compared to the spheromak azimuthal current. It is shown that the stability is related to the distortion of the spheromak separatrix.

C. Litwin; R. N. Sudan; A. D. Turnbull

1984-01-01T23:59:59.000Z

145

Alignment method for solar collector arrays  

DOE Patents (OSTI)

The present invention is directed to an improved method for establishing camera fixture location for aligning mirrors on a solar collector array (SCA) comprising multiple mirror modules. The method aligns the mirrors on a module by comparing the location of the receiver image in photographs with the predicted theoretical receiver image location. To accurately align an entire SCA, a common reference is used for all of the individual module images within the SCA. The improved method can use relative pixel location information in digital photographs along with alignment fixture inclinometer data to calculate relative locations of the fixture between modules. The absolute locations are determined by minimizing alignment asymmetry for the SCA. The method inherently aligns all of the mirrors in an SCA to the receiver, even with receiver position and module-to-module alignment errors.

Driver, Jr., Richard B

2012-10-23T23:59:59.000Z

146

Solar collector construction and sealing arrangement  

SciTech Connect

A sealing arrangement is disclosed by which a glass panel cover may be installed with a weather-tight seal in a solar collector housing. The housing includes side walls, the upper edges of which are formed with a generally cylindrical groove which faces upwardly. The sealing arrangement includes an elongate resilient body formed with a generally cylindrical anchor section having a cross-section of a dimension just the same as or less than the cross-section dimension of the cylindrical groove, and a holding section formed integrally with the anchor section near the top thereof and having a generally U-shaped cross-section which faces inwardly of the housing.

Leflar, J.A.; Wardlow, W.C.

1985-02-12T23:59:59.000Z

147

SunShot Initiative: Collectors R&D for CSP Systems  

NLE Websites -- All DOE Office Websites (Extended Search)

Collectors R&D for CSP Systems to Collectors R&D for CSP Systems to someone by E-mail Share SunShot Initiative: Collectors R&D for CSP Systems on Facebook Tweet about SunShot Initiative: Collectors R&D for CSP Systems on Twitter Bookmark SunShot Initiative: Collectors R&D for CSP Systems on Google Bookmark SunShot Initiative: Collectors R&D for CSP Systems on Delicious Rank SunShot Initiative: Collectors R&D for CSP Systems on Digg Find More places to share SunShot Initiative: Collectors R&D for CSP Systems on AddThis.com... Concentrating Solar Power Systems Components Collectors Receivers Power Block Thermal Storage Systems Analysis Competitive Awards Staff Photovoltaics Systems Integration Balance of Systems Collectors R&D for CSP Systems Collectors-whether for trough, tower (heliostat), linear Fresnel or dish

148

Hydrodynamic analysis of direct steam generation solar collectors  

SciTech Connect

Direct steam generation collectors are considered with the aim to improve the performance of a parabolic trough collector leading to a reduction of operating costs of solar electric generation systems. In this study a hydrodynamic steady state model is developed and linked with a thermal model to optimize the performance of once-through direct steam generation solar collectors. The hydrodynamic model includes flow pattern classification and a pressure drop model. Flow pattern maps for typical DSG collectors with horizontal and inclined absorber tubes are generated to investigate the variation of flow conditions with radiation level, tube diameter, tube length and flow rate. Two-phase flow frictional pressure drop correlations for the range of operating conditions in a DSG collector are selected from the wide range of published correlations by comparison with experimental data for typical steam-water flow conditions in a DSG collector. Pressure drop is calculated for different operating conditions for both horizontal and inclined solar absorber tubes. Alternative operational strategies are evaluated to achieve optimum performance of a direct steam generation collector at different radiation levels.

Odeh, S.D.; Behnia, M.; Morrison, G.L.

2000-02-01T23:59:59.000Z

149

Combined Scanning Transmission Electron Microscopy Tilt- and Focal Series  

SciTech Connect

In this study, a combined tilt- and focal series is proposed as a new recording scheme for high-angle annular dark-field scanning transmission electron microscopy (STEM) tomography. Three-dimensional (3D) data were acquired by mechanically tilting the specimen, and recording a through-focal series at each tilt direction. The sample was a whole-mount macrophage cell with embedded gold nanoparticles. The tilt focal algebraic reconstruction technique (TF-ART) is introduced as a new algorithm to reconstruct tomograms from such combined tilt- and focal series. The feasibility of TF-ART was demonstrated by 3D reconstruction of the experimental 3D data. The results were compared with a conventional STEM tilt series of a similar sample. The combined tilt- and focal series led to smaller missing wedge artifacts, and a higher axial resolution than obtained for the STEM tilt series, thus improving on one of the main issues of tilt series-based electron tomography.

Dahmen, Tim [German Research Center for Artificial Intelligence (DFKI), Germany] [German Research Center for Artificial Intelligence (DFKI), Germany; Baudoin, Jean-Pierre G [ORNL] [ORNL; Lupini, Andrew R [ORNL] [ORNL; Kubel, Christian [Karlsruhe Institute of Technology, Leopoldshafen, Germany] [Karlsruhe Institute of Technology, Leopoldshafen, Germany; Slusallek, Phillip [German Research Center for Artificial Intelligence (DFKI), Germany] [German Research Center for Artificial Intelligence (DFKI), Germany; De Jonge, Niels [ORNL] [ORNL

2014-01-01T23:59:59.000Z

150

Conductivity fuel cell collector plate and method of fabrication  

DOE Patents (OSTI)

An improved method of manufacturing a PEM fuel cell collector plate is disclosed. During molding a highly conductive polymer composite is formed having a relatively high polymer concentration along its external surfaces. After molding the polymer rich layer is removed from the land areas by machining, grinding or similar process. This layer removal results in increased overall conductivity of the molded collector plate. The polymer rich surface remains in the collector plate channels, providing increased mechanical strength and other benefits to the channels. The improved method also permits greater mold cavity thickness providing a number of advantages during the molding process.

Braun, James C. (Juno Beach, FL)

2002-01-01T23:59:59.000Z

151

Spheromak tilting instability in cylindrical geometry  

Science Journals Connector (OSTI)

The internal tilting instability in a force?free spheromak plasma in cylindrical geometry is examined. It is found that this instability originally found in spherical geometry also occurs in cylindrical geometry. The analysis proceeds by first demonstrating that if no mode rational surface is present in the plasma a necessary and sufficient condition for ideal magnetohydrodynamic instability is that there exist a solution to ?×B m = ? m B m where B m ?exp(i m?) with ? m tilting mode is unstable for these parameters. All modes with m?1 are shown to be stable.

John M. Finn; Wallace M. Manheimer; Edward Ott

1981-01-01T23:59:59.000Z

152

Tilting instability of a cylindrical spheromak  

Science Journals Connector (OSTI)

The stability of a low?beta spheromak with a perfectly conducting cylindrical boundary of length L and radius R is analyzed in terms of force?free fields with J = ?B(? = const). The axisymmetric equilibrium is found unstable to tilting when the elongation L/R is larger than about 1.67. Numerical solutions of the time?dependent ideal magnetohydrodynamic equations confirm this result.

A. Bondeson; G. Marklin; Z. G. An; H. H. Chen; Y. C. Lee; C. S. Liu

1981-01-01T23:59:59.000Z

153

Stabilizing windings for tilting and shifting modes  

DOE Patents (OSTI)

This invention relates to passive conducting loops for stabilizing a plasma ring against unstable tilting and/or shifting modes. To this end, for example, plasma ring in a spheromak is stabilized by a set of four figure-8 shaped loops having one pair on one side of the plasma and one pair on the other side with each pair comprising two loops whose axes are transverse to each other.

Jardin, Stephen C. (Princeton, NJ); Christensen, Uffe R. (Princeton, NJ)

1984-01-01T23:59:59.000Z

154

Project Profile: Advanced High Temperature Trough Collector Developmen...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

collector was selected for the Andasol 1 and 2 plants in Spain, the Kuraymat plant in Egypt, and early Solar Millennium commercial projects in the United States. The NTPro design...

155

Numerical Simulation Study on Transpired Solar Air Collector  

E-Print Network (OSTI)

ICEBO2006, Shenzhen, China Re newable Energy Resources and a Greener Future Vol.VIII-3-4 Numerical Simulation Study on Transpired Solar Air Collector Chongjie Wang Zhenzhong Guan Xueyi Zhao Delin Wang Professor...

Wang, C.; Guan, Z.; Zhao, X.; Wang, D.

2006-01-01T23:59:59.000Z

156

Self-Cleaning CSP Collectors, Concentrating Solar Power (Fact Sheet)  

SciTech Connect

Boston University is one of the 2012 SunShot CSP R&D awardees for their advanced collectors. This fact sheet explains the motivation, description, and impact of the project.

Not Available

2012-09-01T23:59:59.000Z

157

Thermal Analysis of Compound—Parabolic Concentrating Solar Energy Collectors  

Science Journals Connector (OSTI)

Despite the vast attention devoted recently to the design and development of effective collectors for harnessing solar energy at medium and high temperatures (>100° ... in the design of the compound parabolic con...

B. Norton; D. E. Prapas

1987-01-01T23:59:59.000Z

158

Central Receiver Plant evaluation: (2) THEMIS collector subsystem evaluation  

SciTech Connect

This report is part of the evaluation work carried out at Ecole Centrale on central receiver plants. The THEMIS collector subsystem is evaluated with emphasis given to the energy performance problems. The collector subsystem, the heliostat, and the operation modes are described. The mechanisms which contribute to the energy losses of the collector subsystem are discussed individually. Heliostat availability, reflectivity, geometrical effects (mirror shadowing and blocking, cosine factor, tower shadowing), beam focusing quality, beam pointing, spillage, propagation losses in the atmosphere between the mirrors and the receiver are successively evaluated. The overall collector efficiency is then estimated from two different points of view. The theoretical performance showing the physical limitation of the system, and the actual performance based on real experimental results, are separately discussed. The electricity consumption of the heliostat field is examined for plant parasitics analysis. The maintenance problems and the lessons learned on hardware behavior at the THEMIS site are also discussed. 19 refs., 7 figs.; 24 tabs.

Amri, A.; Izygon, M.; Tedjiza, B.

1988-01-01T23:59:59.000Z

159

The Actuality and Prospect of Solar Collector Technology in China  

Science Journals Connector (OSTI)

The development tendency and the future of the solar heater utilization product are going to determine the solar energy collector technology development. The vacuum tube solar water heater development direction i...

Luo Yunjun; Liu Airong

2009-01-01T23:59:59.000Z

160

Thermal efficiency of single-pass solar air collector  

SciTech Connect

Efficiency of a finned single-pass solar air collector was studied. This paper presents the experimental study to investigate the effect of solar radiation and mass flow rate on efficiency. The fins attached at the back of absorbing plate to improve the thermal efficiency of the system. The results show that the efficiency is increased proportional to solar radiation and mass flow rate. Efficiency of the collector archived steady state when reach to certain value or can be said the maximum performance.

Ibrahim, Zamry; Ibarahim, Zahari; Yatim, Baharudin [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan (Malaysia); Ruslan, Mohd Hafidz [Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan (Malaysia)

2013-11-27T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Analysis of solar collector array systems using thermography  

SciTech Connect

The use of thermography to analyze large solar collector array systems under dynamic operating conditions is discussed. The research has focused on thermographic techniques and equipment to determine temperature distributions, flow patterns, and air blockages in solar collectors. The results of this extensive study, covering many sites and types of collectors, illustrate the capabilities of infrared analysis as an analysis tool and operation and maintenance procedure when applied to large arrays. Thermographic analysis of most collector systems showed temperature distributions that indicated balanced flow patterns with both the thermographs and the hand-held unit. In three significant cases, blocked or broken collector arrays, which previously had gone undetected, were discovered. Using this analysis, validation studies of large computer codes could examine collector arrays for flow patterns or blockages that could cause disagreement between actual and predicted performance. Initial operation and balancing of large systems could be accomplished without complicated sensor systems not needed for normal operations. Maintenance personnel could quickly check their systems without climbing onto the roof and without complicated sensor systems.

Eden, A.

1980-01-01T23:59:59.000Z

162

Solar collector systems analysis using infrared scanning techniques  

SciTech Connect

Solar energy collector systems analysis using thermography is discussed. The research at the Solar Energy Research Institute (SERI) in this area has focused on infrared (IR) scanning techniques and equipment to determine temperature distributions, flow patterns, and air blockages in solar collectors. The results of this extensive study, covering many sites and types of collectors, illustrate the capabilities of IR analysis as an analysis tool and operation and maintenance procedure when applied to large arrays. Infrared analysis of most collector systems showed temperature distributions that indicated balanced flow patterns with both the thermographs and the hand-held unit. In three significant cases, blocked or broken collector arrays, which previously had gone undetected, were discovered. Using this analysis, validation studies of large computer codes could examine collector arrays for flow patterns or blockages that could cause disagreement between actual and predicted performance. Initial operation and balancing of large systems could be accomplished without complicated sensor systems not needed for normal operations. Maintenance personnel could quickly check their systems without climbing onto the roof and without complicated sensor systems.

Eden, A.

1980-08-01T23:59:59.000Z

163

Performance testing of the Acurex solar-collector Model 3001-03  

SciTech Connect

Results are summarized of tests conducted at the Collector Module Test Facility on an Acurex Model 3001-03 Parabolic Trough Concentrating Solar Collector. Test temperaure range was 100/sup 0/C to 300/sup 0/C. Tests were conducted with the collector axis oriented east-west and again with the collector axis oriented north-south. Three collectors were tested: one using polished aluminum mirrors, one using glass mirrors, and another using an aluminized acrylic film mirror.

Dudley, V.E.; Workhoven, R.M.

1982-03-01T23:59:59.000Z

164

Research and Development of a Low Cost Solar Collector  

SciTech Connect

This is a Final Technical Report on the Research and Development completed towards the development of a Low Cost Solar Collector conducted under the DOE cost-sharing award EE-0003591. The objective of this project was to develop a new class of solar concentrators with geometries and manufacturability that could significantly reduce the fully installed cost of the solar collector field for concentrated solar thermal power plants. The goal of the project was to achieve an aggressive cost target of $170/m2, a reduction of up to 50% in the total installed cost of a solar collector field as measured against the current industry benchmark of a conventional parabolic trough. The project plan, and the detailed activities conducted under the scope of the DOE Award project addressed all major drivers that affect solar collector costs. In addition to costs, the study also focused on evaluating technical performance of new collector architectures and compared them to the performance of the industry benchmark parabolic trough. The most notable accomplishment of this DOE award was the delivery of a full-scale integrated design, manufacturing and field installation solution for a new class of solar collector architecture which has been classified as the Bi-Planar Fresnel Collector (BPFC) and may be considered as a viable alternative to the conventional parabolic trough, as well as the conventional Fresnel collectors. This was in part accomplished through the design and development, all the way through fabrication and test validation of a new class of Linear Planar Fresnel Collector architecture. This architecture offers a number of key differentiating features which include a planar light-weight frame geometry with small mass-manufacturable elements utilizing flat mirror sections. The designs shows significant promise in reducing the material costs, fabrication costs, shipping costs, and on-site field installation costs compared to the benchmark parabolic trough, as well as the conventional Fresnel collector. The noteworthy design features of the BPFC architecture include the use of relatively cheaper flat mirrors and a design which allows the mirror support beam sections to act as load-bearing structural elements resulting in more than a 36% reduction in the overall structural weight compared to an optimized parabolic trough. Also, it was shown that the utilization of small mass-produced elements significantly lowers mass-production and logistics costs that can more quickly deliver economies of scale, even for smaller installations while also reducing shipping and installation costs. Moreover, unlike the traditional Fresnel trough the BPFC architecture does not require complex articulating drive mechanisms but instead utilizes a standard parabolic trough hydraulic drive mechanism. In addition to the development of the Bi-Planar Fresnel Collector, an optimized conventional space-frame type parabolic trough was also designed, built, analyzed and field-tested during the first phase of this award. The design of the conventional space-frame parabolic collector was refined with extensive FEA and CFD analysis to reduce material costs and re-designed for simpler fabrication and more accurate lower-cost field assembly. This optimized parabolic trough represented an improvement over the state-of-the art of the traditional parabolic trough architecture and also served as a more rigorous and less subjective benchmark that was used for comparison of new candidate design architectures. The results of the expanded 1st phase of the DOE award project showed that both the Optimized Parabolic Trough and the new Bi-Planar Fresnel Collector design concepts failed to meet the primary objectives for the project of achieving a 50% cost reduction from the industry reference total installed cost of $350/m2. Results showed that the BPFC came in at projected total installed cost of $237/m2 representing a 32% savings compared to the industry benchmark conventional parabolic trough. And the cost reduction obtained by the Optimized Parabolic Trough compared to the

Ansari, Asif; Philip, Lee; Thouppuarachchi, Chirath

2012-08-01T23:59:59.000Z

165

direct normal irradiance | OpenEI  

Open Energy Info (EERE)

normal irradiance normal irradiance Dataset Summary Description (Abstract): Monthly Average Solar Resource for horizontal and tilted flat-plates, and 2-axis tracking concentrating collectors. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to solar collectors. Source NREL Date Released July 31st, 2006 (8 years ago) Date Updated October 30th, 2007 (7 years ago) Keywords direct normal irradiance DNI GEF GHI GIS global horizontal irradiance insolation latitutde tilt irradiance NASA NREL South America SWERA TILT UNEP Data application/zip icon Download Shapefile and Cell Maps (zip, 13.9 MiB) text/csv icon Download Data (csv, 3.5 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage

166

Africa | OpenEI  

Open Energy Info (EERE)

Africa Africa Dataset Summary Description (Abstract): Monthly Average Solar Resource for horizontal and tilted flat-plates, and 2-axis tracking concentrating collectors. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to solar collectors. Source U.S. National Renewable Energy Laboratory (NREL) Date Released July 31st, 2011 (3 years ago) Date Updated October 30th, 2007 (7 years ago) Keywords Africa direct normal irradiance DNI GEF GHI GIS global horizontal irradiance latitutde tilt irradiance NASA NREL solar SWERA TILT UNEP Data application/zip icon Download Shapefile and Images (zip, 19.3 MiB) text/csv icon Download Data (csv, 3.4 MiB) Quality Metrics Level of Review Some Review

167

Absorber Alignment Measurement Tool for Solar Parabolic Trough Collectors: Preprint  

SciTech Connect

As we pursue efforts to lower the capital and installation costs of parabolic trough solar collectors, it is essential to maintain high optical performance. While there are many optical tools available to measure the reflector slope errors of parabolic trough solar collectors, there are few tools to measure the absorber alignment. A new method is presented here to measure the absorber alignment in two dimensions to within 0.5 cm. The absorber alignment is measured using a digital camera and four photogrammetric targets. Physical contact with the receiver absorber or glass is not necessary. The alignment of the absorber is measured along its full length so that sagging of the absorber can be quantified with this technique. The resulting absorber alignment measurement provides critical information required to accurately determine the intercept factor of a collector.

Stynes, J. K.; Ihas, B.

2012-04-01T23:59:59.000Z

168

Fuel cell collector plate and method of fabrication  

DOE Patents (OSTI)

An improved molding composition is provided for compression molding or injection molding a current collector plate for a polymer electrolyte membrane fuel cell. The molding composition is comprised of a polymer resin combined with a low surface area, highly-conductive carbon and/or graphite powder filler. The low viscosity of the thermoplastic resin combined with the reduced filler particle surface area provide a moldable composition which can be fabricated into a current collector plate having improved current collecting capacity vis-a-vis comparable fluoropolymer molding compositions.

Braun, James C. (Juno Beach, FL); Zabriskie, Jr., John E. (Port St. Lucie, FL); Neutzler, Jay K. (Palm Beach Gardens, FL); Fuchs, Michel (Boynton Beach, FL); Gustafson, Robert C. (Palm Beach Gardens, FL)

2001-01-01T23:59:59.000Z

169

SunShot Initiative: Next-Generation Solar Collectors for CSP  

NLE Websites -- All DOE Office Websites (Extended Search)

Next-Generation Solar Collectors Next-Generation Solar Collectors for CSP to someone by E-mail Share SunShot Initiative: Next-Generation Solar Collectors for CSP on Facebook Tweet about SunShot Initiative: Next-Generation Solar Collectors for CSP on Twitter Bookmark SunShot Initiative: Next-Generation Solar Collectors for CSP on Google Bookmark SunShot Initiative: Next-Generation Solar Collectors for CSP on Delicious Rank SunShot Initiative: Next-Generation Solar Collectors for CSP on Digg Find More places to share SunShot Initiative: Next-Generation Solar Collectors for CSP on AddThis.com... Concentrating Solar Power Systems Components Competitive Awards CSP Research & Development Thermal Storage CSP Recovery Act Baseload CSP SunShot Multidisciplinary University Research Initiative CSP Heat Integration for Baseload Renewable Energy Deployment

170

Cost goals for a residential photovoltaicthermal liquid collector system set in three northern locations  

E-Print Network (OSTI)

This study compares the allowable costs for a residential PV/T liquid collector system with those of both PV-only and side-by-side PV and thermal collector systems. Four types of conventional energy systems provide backup: ...

Dinwoodie, Thomas L.

1980-01-01T23:59:59.000Z

171

Next Generation Solar Collectors for CSP - FY13 Q1 | Department...  

Office of Environmental Management (EM)

Next Generation Solar Collectors for CSP - FY13 Q1 Next Generation Solar Collectors for CSP - FY13 Q1 This document summarizes the progress of this 3M project, funded by SunShot,...

172

On Integration of Mirror Collector and Stirling Engine for Solar Power System  

Science Journals Connector (OSTI)

In the current work, several types of solar collectors, i.e. parabolic, cylindrical, and mirrors, were designed and fabricated. The aim of this study is to integrate the optimum collector with Stirling engine in ...

B.F. Yousif; Ammar Al-Shalabi; Dirk G. Rilling

2011-01-01T23:59:59.000Z

173

Analyser av effektivitet til nyutviklet solfanger i polymermateriale = Analyses of the efficiency for a new polymer solar collector.  

E-Print Network (OSTI)

??In this thesis, variations in efficiency between two different solar collectors have been measured. Solar collector efficiency has been measured at different levels of flow.… (more)

Schakenda, Jeanette A.

2004-01-01T23:59:59.000Z

174

NREL Develops New Optical Evaluation Approach for Parabolic Trough Collectors (Fact Sheet)  

SciTech Connect

New analytical method makes it possible to carry out fast evaluation of trough collectors for design purposes.

Not Available

2012-08-01T23:59:59.000Z

175

Solar-collector manufacturing activity, July through December, 1981  

SciTech Connect

Solar thermal collector and solar cell manufacturing activity is both summarized and tabulated. Data are compared for three survey periods (July through December, 1981; January through June, 1981; and July through December, 1980). Annual totals are also provided for the years 1979 through 1981. Data include total producer shipments, end use, market sector, imports and exports. (LEW)

None

1982-03-01T23:59:59.000Z

176

PERFORMANCE OF A CONCENTRATING PHOTOVOLTAIC/THERMAL SOLAR COLLECTOR  

E-Print Network (OSTI)

increased solar energy conversion and potential cost benefits (Fujisawa and Tani, 1997, 2001, Huang et alPERFORMANCE OF A CONCENTRATING PHOTOVOLTAIC/THERMAL SOLAR COLLECTOR Joe S Coventry Centre for Sustainable Energy Systems, Australian National University, Canberra, 0200, Australia +612 6125 3976, +612

177

Evaluation of solar collectors for heat pump applications. Final report  

SciTech Connect

The study was initiated to evaluate the potential utility of very low cost (possibly unglazed and uninsulated) solar collectors to serve as both heat collection and rejection devices for a liquid source heat pump. The approach consisted of exercising a detailed analytical simulation of the complete heat pump/solar collector/storage system against heating and cooling loads derived for typical single-family residences in eight US cities. The performance of each system was measured against that of a conventional air-to-air heat pump operating against the same loads. In addition to evaluation of solar collector options, the study included consideration of water tanks and buried pipe grids to provide thermal storage. As a supplement to the analytical tasks, the study included an experimental determination of night sky temperature and convective heat transfer coefficients for surfaces with dimensions typical of solar collectors. The experiments were conducted in situ by placing the test apparatus on the roofs of houses in the Denver, Colorado, area. (MHR)

Not Available

1980-08-01T23:59:59.000Z

178

Genetic algorithms used for the optimization of light-emitting diodes and solar thermal collectors  

E-Print Network (OSTI)

Genetic algorithms used for the optimization of light-emitting diodes and solar thermal collectors developed for the optimization of light-emitting diodes (LED) and solar thermal collectors. The surface a light-extraction efficiency of only 3.7%). The solar thermal collector we considered consists

Mayer, Alexandre

179

Geometric Model of a Narrow Tilting CAR using Robotics formalism  

E-Print Network (OSTI)

- structured multibody system composed of n bodies (links) where the chassis is the mobile base and the wheels tilting car "Lumeneo Smera" [4] through the analysis of its tilting mechanism. To model a complex system. Robotic representation of a multibody system The car can be seen as a mobile robot which is a tree

Boyer, Edmond

180

Three-Dimensional Simulation of Spheromak Creation and Tilting Disruption  

Science Journals Connector (OSTI)

Spheromak dynamics is studied for a zero-? plasma by a three-dimensional magneto-hydrodynamics simulation code. The growth rate of the tilting instability is found to be of the order of 10?A (Alfvén transit time) and, more interestingly, once tilt occurs, the spheromak field reconnects three dimensionally with the vertical field, thus leading to a disruptive deformation of the spheromak.

Tetsuya Sato and Takaya Hayashi

1983-01-03T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

File:NREL-asia-tilt.pdf | Open Energy Information  

Open Energy Info (EERE)

asia-tilt.pdf asia-tilt.pdf Jump to: navigation, search File File history File usage Selected Asian Countries - Annual Tilted at Latitude Solar Radiation (PDF) Size of this preview: 776 × 600 pixels. Full resolution ‎(1,650 × 1,275 pixels, file size: 3.05 MB, MIME type: application/pdf) Title Selected Asian Countries - Annual Tilted at Latitude Solar Radiation (PDF) Description Selected Asian Countries - Annual Tilted at Latitude Solar Radiation (PDF) Sources National Renewable Energy Laboratory Authors Donna Heimiller Related Technologies Solar, Solar-PV, Solar-40km Creation Date 2006-07-13 Extent International Countries Bhutan, China, Nepal, Mongolia, India, North Korea, South Korea, Vietnam, Laos, Thailand, Cambodia, Philippines, Bangladesh UN Region Southern Asia, Eastern Asia, South-Eastern Asia

182

File:SWERA-254.pdf | Open Energy Information  

Open Energy Info (EERE)

Solar: monthly and annual latitude tilt horizontal GIS data at 40km resolution for Nepal from NREL Solar: monthly and annual latitude tilt horizontal GIS data at 40km resolution for Nepal from NREL Size of this preview: 776 × 600 pixels. Full resolution ‎(1,650 × 1,275 pixels, file size: 240 KB, MIME type: application/pdf) Title Monthly Average Solar Resource for flat-plate collectors tilted at latitude for Nepal. Description Solar: monthly and annual latitude tilt horizontal GIS data at 40km resolution for Nepal from NREL Sources National Renewable Energy Laboratory Related Technologies Solar Creation Date 2005-04-12 Extent International Countries Nepal UN Region Southern Asia External links http://swera.unep.net/index.php?id=35&idx=254 File history Click on a date/time to view the file as it appeared at that time. Date/Time Thumbnail Dimensions User Comment

183

Lightweight diaphragm mirror module system for solar collectors  

DOE Patents (OSTI)

A mirror module system is provided for accurately focusing solar radiation on a point or a line as defined by an array of solar collectors. Each mirror module includes a flexible membrane stretched over a frame in a manner similar to that of a drum or a trampoline and further includes a silvered glass or plastic mirror for forming an optical reflecting surface. The configuration of the optical reflecting surface is variably adjustable to provide for the accurate focusing of the solar energy on a given collector array, e.g., a point or a linear array arrangement. The flexible mirror-membrane combination is lightweight to facilitate installation and reduce system cost yet structurally strong enough to provide for the precise focusing of the incident solar radiation in a semi-rigid reflector system in which unwanted reflector displacement is minimized.

Butler, B.L.

1984-01-01T23:59:59.000Z

184

A Linear Parabolic Trough Solar Collector Performance Model  

E-Print Network (OSTI)

: 1 bar (winter) Pressure in solar collection loop: 10 bar (Summer), 5 bar (winter) Pressure in main chilled water loop : 1 bar (summer) TIC TIC TIC TIC Space Thermostat May 18,06 Parabolic Solar Trough Collector: 52.44 m^2 / 4 modules... & winter) Chilled/Heat Water Storage Current Existing Future Installation Current Installation TIC TIC EIC Temperature indicator controller Energy indicator controller Fig. 1 IW solar heating and cooling system 1.3 EES Model In order to understand...

Qu, M.; Archer, D.; Masson, S.

2006-01-01T23:59:59.000Z

185

Electrochemically Stable Cathode Current Collectors for Rechargeable Magnesium Batteries  

SciTech Connect

Rechargeable Mg batteries are attractive energy storage systems and could bring cost-effective energy solutions. Currently, however, no practical cathode current collectors that can withstand high voltages in Mg2+ electrolytes has been identified and therefore cathode research is greatly hindered. Here we identified that two metals, Mo and W, are electrochemically stable through formation of surface passive layers. The presented results could have significant impacts on the developments of high voltage Mg batteries.

Cheng, Yingwen; Liu, Tianbiao L.; Shao, Yuyan; Engelhard, Mark H.; Liu, Jun; Li, Guosheng

2014-01-01T23:59:59.000Z

186

Asia | OpenEI  

Open Energy Info (EERE)

10 10 Varnish cache server Browse Upload data GDR 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2142281010 Varnish cache server Asia Dataset Summary Description (Abstract): Monthly Average Solar Resource for horizontal and tilted flat-plates, and 2-axis tracking concentrating collectors. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to solar collectors. Source NREL Date Released July 31st, 2006 (8 years ago) Date Updated October 30th, 2007 (7 years ago) Keywords Asia DNI GEF GHI insolation NREL solar SWERA TILT UNEP Data application/zip icon Download Shapefile and Cell Regions (zip, 20.2 MiB) text/csv icon Download Data (csv, 960.7 KiB)

187

insolation | OpenEI  

Open Energy Info (EERE)

2 2 Varnish cache server Browse Upload data GDR 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2142278432 Varnish cache server insolation Dataset Summary Description (Abstract): Monthly Average Solar Resource for horizontal and tilted flat-plates, and 2-axis tracking concentrating collectors. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to solar collectors. Source NREL Date Released July 31st, 2006 (8 years ago) Date Updated October 30th, 2007 (7 years ago) Keywords Asia DNI GEF GHI insolation NREL solar SWERA TILT UNEP Data application/zip icon Download Shapefile and Cell Regions (zip, 20.2 MiB) text/csv icon Download Data (csv, 960.7 KiB)

188

Sloped-collector solar updraft tower power plant performance  

Science Journals Connector (OSTI)

Abstract A mathematical model describing fluid flow, heat transfer and pressure distribution inside a sloped-collector solar updraft tower power plant (SCSUTPP) is presented by assuming a steady compressible flow. Compared to conventional horizontal-collector solar updraft tower power plants (HCSUTPPs), the performance of SCSUTPP is comprehensively studied based on the mathematical model. The power outputs for SCSUTPP and HCSUTPP using the essential expression of driving force are respectively compared with those using the driving force expressions containing no integral, as proposed in literature. Results show that the expression containing no integral is accurate for HCSUCPP based on a compressible fluid model. The expression containing no integral is not accurate for predicting the driving force of SCSUTPP based on an incompressible fluid model when no variation of the atmospheric density with heights and no variation of difference of the atmospheric density and the density of the current inside the short SUT with heights are assumed. The gravitational effect has to be considered for predicting the SCSUTPP performance. The results show that the pressure potential and the power production of an SCSUCPP with a collector of 848 m height and a vertical SUT 123 m high lies between those for two \\{HCSUCPPs\\} respectively with vertical \\{SUTs\\} 547 m and 971 m high. This work lays a good foundation for accurate predication of potential power produced from SCSUTPP.

Xinping Zhou; Shuo Yuan; Marco Aurélio dos Santos Bernardes

2013-01-01T23:59:59.000Z

189

Macroscopic Subdivision of Silica Aerogel Collectors for Sample Return Missions  

SciTech Connect

Silica aerogel collector tiles have been employed for the collection of particles in low Earth orbit and, more recently, for the capture of cometary particles by NASA's Stardust mission. Reliable, reproducible methods for cutting these and future collector tiles from sample return missions are necessary to maximize the science output from the extremely valuable embedded particles. We present a means of macroscopic subdivision of collector tiles by generating large-scale cuts over several centimeters in silica aerogel with almost no material loss. The cut surfaces are smooth and optically clear allowing visual location of particles for analysis and extraction. This capability is complementary to the smaller-scale cutting capabilities previously described [Westphal (2004), Ishii (2005a, 2005b)] for removing individual impacts and particulate debris in tiny aerogel extractions. Macroscopic cuts enable division and storage or distribution of portions of aerogel tiles for immediate analysis of samples by certain techniques in situ or further extraction of samples suited for other methods of analysis.

Ishii, H A; Bradley, J P

2005-09-14T23:59:59.000Z

190

The Properties of the Tilts of Bipolar Solar Regions  

E-Print Network (OSTI)

We investigate various properties associated with the tilt of isolated magnetic bipoles in magnetograms taken at the solar surface. We show that bipoles can be divided into two groups which have tilts of opposite signs, and reveal similar properties with respect to bipole area, flux and bipolar moment. Detailed comparison of these physical quantities shows that the dividing point between the two types of bipoles corresponds to a bipole area of about 300 millionths of the solar hemisphere (MHS). The time-latitude distribution of small bipoles differs substantially from that for large bipoles. Such behaviour in terms of dynamo theory may indicate that small and large bipoles trace different components of the solar magnetic field. The other possible viewpoint is that the difference in tilt data for small and large bipoles is connected with spectral helicity separation, which results in opposite tilts for small and large bipoles. We note that the data available do not provide convincing reasons to prefer either i...

Illarionov, E; Sokoloff, D

2014-01-01T23:59:59.000Z

191

Position vs. Velocity Control for Tilt-Based Interaction Robert J. Teather*  

E-Print Network (OSTI)

like a steering wheel, and "marble maze" games where tilting rolls a ball to simulate gravity. Although's subjective impression of the system. 2 RELATED WORK 2.1 Tilt-Based Interaction Tilt control has long been

MacKenzie, Scott

192

New Optical Evaluation Approach for Parabolic Trough Collectors: First-Principle OPTical Intercept Calculation  

SciTech Connect

A new analytical method -- First-principle OPTical Intercept Calculation (FirstOPTIC) -- is presented here for optical evaluation of trough collectors. It employs first-principle optical treatment of collector optical error sources and derives analytical mathematical formulae to calculate the intercept factor of a trough collector. A suite of MATLAB code is developed for FirstOPTIC and validated against theoretical/numerical solutions and ray-tracing results. It is shown that FirstOPTIC can provide fast and accurate calculation of intercept factors of trough collectors. The method makes it possible to carry out fast evaluation of trough collectors for design purposes. The FirstOPTIC techniques and analysis may be naturally extended to other types of CSP technologies such as linear-Fresnel collectors and central-receiver towers.

Zhu, G.; Lewandowski, A.

2012-11-01T23:59:59.000Z

193

Performance characterisation and energy savings of uncovered swimming pool solar collectors under reduced flow rate conditions  

Science Journals Connector (OSTI)

The effects of reduced flow rates on the performance and effectiveness of domestic unglazed, uninsulated pool solar collector heaters are investigated. The study shows electrical energy savings in excess of 80% are achievable for typical solar collectors operating at flow rates reduced by up to 75% while collector efficiency is only reduced by approximately 10–15%. The reduction of electrical energy required for pumping and the increased COP of reduced flow through typical pool solar thermal collectors is shown to far outweigh the small loss of collector performance attributable to the change in flow rates. The ratio of thermal energy delivered to the electrical energy supplied was improved in the order of 400% for the collector tested.

L.N. Cunio; A.B. Sproul

2012-01-01T23:59:59.000Z

194

Experiments on solar absorption using a greenhouse-effect gas in a thermal solar collector  

Science Journals Connector (OSTI)

This paper investigates an augmentation to the thermal solar absorption of solar collectors by introducing a greenhouse gas between the glazing and the absorber part of the solar collector. Experiments are designed and conducted to compare the effect of adding the gas on the efficiency of the collector without that addition. The maximum temperature rise of the absorber the time of heat retention before reaching room temperature and the energy conversion efficiency in heating up water for domestic use were all studied.

Abdul Hai M. B. Alami

2010-01-01T23:59:59.000Z

195

10 MWe solar thermal central receiver pilot plant. Collector subsystem functional test plan  

SciTech Connect

This Phase II Collector Subsystem Functional Test Plan presents the functional testing to be performed to demonstrate the readiness of the Collector Subsystem for the Integrated Acceptance Tests. The functional testing will be performed with the collector subsystem as a stand-alone subsystem. In this context, all heliostat operational commands will be issued from the Heliostat Array Controller (HAC) and heliostat responses will be verified by visual means and from the HAC status displays.

Not Available

1981-11-17T23:59:59.000Z

196

Equivalencing the Collector System of a Large Wind Power Plant: Preprint  

SciTech Connect

This paper focuses on our effort to develop an equivalent representation of a wind power plant collector system for power system planning studies.

Muljadi, E.; Butterfield, C. P.; Ellis, A.; Mechenbier, J.; Hochheimer, J.; Young, R.; Miller, N.; Delmerico, R.; Zavadil, R.; Smith, J. C.

2006-01-01T23:59:59.000Z

197

Off-peak summer performance enhancement for rows of fixed solar thermal collectors using reflective surfaces.  

E-Print Network (OSTI)

??The possibility of increasing the efficiency of fixed solar thermal collectors without greatly adding to the cost or complexity of the overall solar collection system… (more)

Armenta, Casiano

2011-01-01T23:59:59.000Z

198

Estimation of Damage to the Collector of a Water Economizer by Thermal Fatigue Cracks  

Science Journals Connector (OSTI)

We study defects formed on the outer and inner surfaces of the input collector of water economizer of a TPP-312 boiler at the...

R. Ya. Kosarevych; O. Z. Student; Ya. D. Onyshchak; A. D. Markov…

2004-01-01T23:59:59.000Z

199

A prototype photovoltaic/thermal system integrated with transpired collector  

SciTech Connect

Building-integrated photovoltaic/thermal (BIPV/T) systems may be utilized to produce useful heat while simultaneously generating electricity from the same building envelope surface. A well known highly efficient collector is the open-loop unglazed transpired collector (UTC) which consists of dark porous cladding through which outdoor air is drawn and heated by absorbed solar radiation. Commercially available photovoltaic systems typically produce electricity with efficiencies up to about 18%. Thus, it is beneficial to obtain much of the normally wasted heat from the systems, possibly by combining UTC with photovoltaics. Combination of BIPV/T and UTC systems for building facades is considered in this paper - specifically, the design of a prototype facade-integrated photovoltaic/thermal system with transpired collector (BIPV/T). A full scale prototype is constructed with 70% of UTC area covered with PV modules specially designed to enhance heat recovery and compared to a UTC of the same area under outdoor sunny conditions with low wind. The orientation of the corrugations in the UTC is horizontal and the black-framed modules are attached so as to facilitate flow into the UTC plenum. While the overall combined thermal efficiency of the UTC is higher than that of the BIPV/T system, the value of the generated energy - assuming that electricity is at least four times more valuable than heat - is between 7% and 17% higher. Also, the electricity is always useful while the heat is usually utilized only in the heating season. The BIPV/T concept is applied to a full scale office building demonstration project in Montreal, Canada. The ratio of photovoltaic area coverage of the UTC may be selected based on the fresh air heating needs of the building, the value of the electricity generated and the available building surfaces. (author)

Athienitis, Andreas K.; Bambara, James; O'Neill, Brendan; Faille, Jonathan [Dept. of Building, Civil and Environmental Engineering, Concordia University, 1455 Maisonneuve W., Montreal, Quebec (Canada)

2011-01-15T23:59:59.000Z

200

Exergetic optimization of solar collector and thermal energy storage system  

Science Journals Connector (OSTI)

This paper deals with the exergetic optimization of a solar thermal energy system. This consists of a solar collector (SC) and a rectangular water storage tank (ST) that contains a phase change material (PCM) distributed in an assembly of slabs. The study takes into account both conduction and convection heat transfer mode for water in the SC, and also the phase change process for the PCM in the ST. An analytical solution for the melting process in the PCM is also presented. The results of the study are compared with previous experimental data, confirming the accuracy of the model. Results of a numerical case study are presented and discussed.

F. Aghbalou; F. Badia; J. Illa

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Optimization of a hybrid solar energy collector system  

E-Print Network (OSTI)

OPTIMIZATION OF A HYBRID SOLAR ENERGY COLLECTOR SYSTEM A Thesis by ALAN M. SHI NEMAN Submitted to the Graduate College of Texas A&N University in partial fulfillment of the requirement for the degree MASTER OF SCIENCE May 1981 Major Subject...: Mechanical Engineering THE STRUCTURAL IMPACT OF COMMODITY FARM PROGRAMS ON FARMS IN THE SOUTHERN TEXAS HIGH PLAINS A Thesis by CHRISTINA KAY SHIRLEY Submitted to the Graduate College of Texas A&M University in par'tial fulfillment of the requirement...

Shinkman, Alan M.

1981-01-01T23:59:59.000Z

202

Laser Guide Star Adaptive Optics without Tip-tilt  

E-Print Network (OSTI)

Adaptive optics (AO) systems allow a telescope to reach its diffraction limit at near infrared wavelengths. But to achieve this, a bright natural guide star (NGS) is needed for the wavefront sensing, severely limiting the fraction of the sky over which AO can be used. To some extent this can be overcome with a laser guide star (LGS). While the laser can be pointed anywhere in the sky, one still needs to have a natural star, albeit fainter, reasonably close to correct the image motion (tip-tilt) to which laser guide stars are insensitive. There are in fact many astronomical targets without suitable tip-tilt stars, but for which the enhanced resolution obtained with the Laser Guide Star Facility (LGSF) would still be very beneficial. This article explores what adaptive optics performance one might expect if one dispenses with the tip-tilt star, and in what situations this mode of observing might be needed.

R. Davies; S. Rabien; C. Lidman; M. Le Louarn; M. Kasper; N. M. Forster Schreiber; V. Roccatagliata; N. Ageorges; P. Amico; C. Dumas; F. Mannucci

2008-01-24T23:59:59.000Z

203

Spheromak tilt stabilization with an energetic particle component  

Science Journals Connector (OSTI)

The tilt and shift stability of a spheromak plasma in the presence of a large orbit ion?ring component is determined by evaluating the magnetic interaction of the plasma with the ion ring and the external coils. Neither the ion?ring toroidal current nor the ring inverse aspect ratio is required to be small. The influence of conducting walls is considered to be negligible as is appropriate for compression experiments. The plasma tilt and shift stability has been evaluated for a comprehensive set of numerically generated self?consistent hybrid spheromak/ion?ring equilibria. Stable equilibria are found over a considerable range of the parameters. The tilt stabilization of the plasma typically requires that more than about 25% of the total toroidal current be carried by the ion ring.

C. Mehanian; R. V. E. Lovelace

1988-01-01T23:59:59.000Z

204

Reverse time migration in tilted transversely isotropic media  

SciTech Connect

This paper presents a reverse time migration (RTM) method for the migration of shot records in tilted transversely isotropic (TTI) media. It is based on the tilted TI acoustic wave equation that was derived from the dispersion relation. The RTM is a full depth migration allowing for velocity to vary laterally as well as vertically and has no dip limitations. The wave equation is solved by a tenth-order finite difference scheme. Using 2D numerical models, we demonstrate that ignoring the tilt angle will introduce both lateral and vertical shifts in imaging. The shifts can be larger than 0.5 wavelength in the vertical direction and 1.5 wavelength in the lateral direction.

Zhang, Linbing; Rector III, James W.; Hoversten, G. Michael

2004-07-01T23:59:59.000Z

205

File:SWERA-248.pdf | Open Energy Information  

Open Energy Info (EERE)

pdf pdf Jump to: navigation, search File File history File usage Solar: monthly latitude tilt GIS data at 40km resolution for Bangladesh from NREL Size of this preview: 776 × 600 pixels. Full resolution ‎(1,650 × 1,275 pixels, file size: 248 KB, MIME type: application/pdf) Title Monthly Average Solar Resource for flat-plate collectors tilted at latitude for Bangladesh. Description Solar: monthly latitude tilt GIS data at 40km resolution for Bangladesh from NREL Sources National Renewable Energy Laboratory Related Technologies Solar Creation Date 2005-04-12 Extent International Countries Bangladesh UN Region Southern Asia External links http://swera.unep.net/index.php?id=35&idx=248 File history Click on a date/time to view the file as it appeared at that time.

206

Hydrogen Crack Growth Resistance of Thermal Power Plant Material Collector  

Science Journals Connector (OSTI)

Abstract The influence of electrolytical hydrogenation on fracture toughness, corrosion crack-growth resistance and fracture micromechanisms of operated 12Cr1MoV steel of thermal power plant superheater collector has been studied. Compact tension specimens were cut from perforated surface of thermal power plant superheater collector dismounted after 178,500 hours of operation. Corrosion crack-growth resistance under tension of previously hydrogenated compact specimens with fatigue cracks was studied. Due to the increased concentration of hydrogen in solution an additional buffer was being created that prevents hydrogen leakage from the specimen through the fracture surface during the experiment. The hydrogenation causes the significant decrease of critical stress intensity factor Kc, during the experiment in 0.1 N NaOH solution as compared with critical stress intensity factor K of non-hydrogenation 12Cr1MoV steel obtained by the 5% secant line method and in comparison with critical stress intensity factor Kc, determined through the J-integral. The areas of ductile crack growth in hydrogenated and non-hydrogenated specimens were found to have similar material fracture micromechanisms with dimples creation of different shape and size. But on the ductile crack growth area in hydrogenated specimens material intergranular fracture mechanisms were found caused by the hydrogen embrittlement which are similar to areas without ridges with the products corrosion traces.

V. Iasnii; P. Maruschak; O. Yasniy; Y. Lapusta

2014-01-01T23:59:59.000Z

207

Cable tensioned membrane solar collector module with variable tension control  

DOE Patents (OSTI)

Disclosed is a solar collector comprising a membrane for concentrating sunlight, a plurality of elongated structural members for suspending the membrane member thereon, and a plurality of control members for adjustably tensioning the membrane member, as well as for controlling a focus produced by the membrane members. Each control member is disposed at a different corresponding one of the plurality of structural members. The collector also comprises an elongated flexible tensioning member, which serves to stretch the membrane member and to thereafter hold it in tension, and a plurality of sleeve members, which serve to provide the membrane member with a desired surface contour during tensioning of the membrane member. The tensioning member is coupled to the structural members such that the tensioning member is adjustably tensioned through the structural members. The tensioning member is also coupled to the membrane member through the sleeve members such that the sleeve members uniformly and symmetrically stretch the membrane member upon applying tension to the tensioning member with the control members.

Murphy, Lawrence M. (Lakewood, CO)

1985-01-01T23:59:59.000Z

208

Cable tensioned membrane solar collector module with variable tension control  

DOE Patents (OSTI)

Disclosed is a solar collector comprising a membrane member for concentrating sunlight, a plurality of elongated structural members for suspending the membrane member thereon, and a plurality of control members for adjustably tensioning the membrane member, as well as for controlling a focus produced by the membrane members. Each control member is disposed at a different corresponding one of the plurality of structural members. The collector also comprises an elongated flexible tensioning member, which serves to stretch the membrane member and to thereafter hold it in tension, and a plurality of sleeve members which serve to provide the membrane member with a desired surface contour during tensioning of the membrane member. The tensioning member is coupled to the structural members such that the tensioning member is adjustably tensioned through the structural members. The tensioning member is also coupled to the membrane member through the sleeve members such that the sleeve members uniformly and symmetrically stretch the membrane member upon applying tension to the tensioning member with the control members.

Murphy, L.M.

1984-01-09T23:59:59.000Z

209

Solar pumping installation for pumping liquid and solar collector construction  

SciTech Connect

A solar pumping system, comprises, a pumping housing which defines a pump chamber therein which is adapted to be positioned in the ground below ground water level. Displacer means in the form of, for example, a bladder, arranged within the pump chamber, is capable of displacing liquid out of the pump chamber in response to a pressurized medium acting thereon to expel the water out of the chamber and up to a level above the ground for use. A suction valve connected into the chamber permits the ground water to flow into the chamber and a discharge valve connected out of the chamber permits the outflow of the ground water during the action of the displacer means. The construction includes a solar collector having at least one hydride conduit which is adapted to be exposed to the sun for solar heating to act on the hydride to cause hydrogen to be formed, the pressure of which acts against the displacer means to displace the ground liquid out of the pump chamber. When the solar collector is shielded and the hydride is permitted to cool or is cooled rapidly by the circulation of water thereover, the pressure of the generated hydrogen decreases, permitting ground water to enter into the pumping chamber once again through the suction valves.

Seidel, A.; Wolf, D.

1984-03-27T23:59:59.000Z

210

Iris tilting and RF steering in the SLAC Linac  

SciTech Connect

For some time now, the sources of RF transverse beam steering in the SLAC Linac have been a mystery. The previously known sources, coupler asymmetries and survey misalignment, have predicted deflections which are frequently much smaller than the observed deflections. A new source of RF steering has been discovered: the tilting of accelerator irises. Measurements of iris tilting in a forty foot accelerator girder are compared with measurements of RF beam deflections and are found to be strongly correlated. 4 refs., 6 figs., 3 tabs.

Seeman, J.T.

1985-05-02T23:59:59.000Z

211

Research at the Building Research Establishment into the Applications of Solar Collectors for Space and Water Heating in Buildings [and Discussion  

Science Journals Connector (OSTI)

...experimental low energy house laboratories, one using conventional solar collectors with interseasonal heat storage and the other a heat pump with an air solar collector. Studies of the cost-effectiveness of solar collector applications to buildings...

1980-01-01T23:59:59.000Z

212

Energy-based Control of a Distributed Solar Collector Tor A. Johansena  

E-Print Network (OSTI)

Energy-based Control of a Distributed Solar Collector Field Tor A. Johansena Camilla Storaaa that the primary energy source, solar radiation, cannot be manipulated. The distributed solar collector eld may, Norway. Model-based control of the outlet temperature of a distributed solar col- lector eld is studied

Johansen, Tor Arne

213

Experimental Performance of a Solar Collector in Solar Chimney Power Plant System  

Science Journals Connector (OSTI)

Solar chimney power plant has been proposed as a device to economically generate electricity from solar energy in large scale in the future. There are many factors to influence on the performance of the solar collector. This paper describes details of ... Keywords: generate electricity, thermal storage material, pebbles, solar collector

Huilan Huang; Gang Li; Hua Zhang

2010-06-01T23:59:59.000Z

214

Review of state-of-the-art of solar collector corrosion processes. Task 1 of solar collector studies for solar heating and cooling applications. Final technical progress report  

SciTech Connect

The state-of-the-art of solar collector corrosion processes is reviewed, and Task 1 of a current research program on use of aqueous heat transfer fluids for solar heating and cooling is summarized. The review of available published literature has indicated that lack of quantitative information exists relative to collector corrosion at the present time, particularly for the higher temperature applications of solar heating and cooling compared to domestic water heating. Solar collector systems are reviewed from the corrosion/service life viewpoint, with emphasis on various applications, collector design, heat transfer fluids, and freeze protection methods. Available information (mostly qualitative) on collector corrosion technology is reviewed to indicate potential corrosion problem areas and corrosion prevention practices. Sources of limited quantitative data that are reviewed are current solar applications, research programs on collector corrosion, and pertinent experience in related applications of automotive cooling and non-solar heating and cooling. A data bank was developed to catalog corrosion information. Appendix A of this report is a bibliography of the data bank, with abstracts reproduced from presently available literature accessions (about 220). This report is presented as a descriptive summary of information that is contained in the data bank.

Clifford, J E; Diegle, R B

1980-04-11T23:59:59.000Z

215

Attaching solar collectors to a structural framework utilizing a flexible clip  

DOE Patents (OSTI)

Methods and apparatuses described herein provide for the attachment of solar collectors to a structural framework in a solar array assembly. A flexible clip is attached to either end of each solar collector and utilized to attach the solar collector to the structural framework. The solar collectors are positioned to allow a member of the framework to engage a pair of flexible clips attached to adjacent solar collectors during assembly of the solar array. Each flexible clip may have multiple frame-engaging portions, each with a flange on one end to cause the flexible clip to deflect inward when engaged by the framework member during assembly and to guide each of the frame-engaging portions into contact with a surface of the framework member for attachment.

Kruse, John S

2014-03-25T23:59:59.000Z

216

Receiver for solar energy collector having improved aperture aspect  

DOE Patents (OSTI)

A secondary concentrator for use in receiver systems for linear focusing primary concentrators is provided with reflector wings at each end. The wings increase the capture of light rays reflected from areas adjacent the rim of a primary concentrator, increasing the apparent aperture size of the absorber as viewed from the rim of the primary concentrator. The length, tilt, and curvature of the wing reflectors can be adjusted to provide an absorber having a desired aperture aspect.

McIntire, William R. (Downers Grove, IL)

1984-01-01T23:59:59.000Z

217

Advanced Manufacture of Second-Surface, Silvered Glass Reflectors for High-Performance, Low-Cost CSP Collector Systems  

Energy.gov (U.S. Department of Energy (DOE))

Advanced Manufacture of Second-Surface, Silvered Glass Reflectors for High-Performance, Low-Cost CSP Collector Systems

218

Linear Fresnel Collector Receiver: Heat Loss and Temperatures  

Science Journals Connector (OSTI)

Abstract For design and component specification of a Linear Fresnel Collector (LFC) cavity receiver, the prediction of temperature distribution and heat loss is of great importance. In this paper we present a sensitivity analysis for a range of geometry and material parameters. For the LFC receiver analysis we use two models developed at Fraunhofer ISE. One is a detailed model, combining the spatial distribution of reflected radiation via ray tracing with detailed convective simulations through computational fluid dynamics. The second one is a fast algorithm based on a thermal resistance model. It is applying a similar methodology as the well-known model for vacuum absorber, enhancing an absorber tube model by parameters describing the influence of the secondary mirror and cover glass. The thermal resistance model is described in detail. Obtained results indicate a significant effect of the secondary mirror temperature on heat loss for specific geometries.

A. Heimsath; F. Cuevas; A. Hofer; P. Nitz; W.J. Platzer

2014-01-01T23:59:59.000Z

219

Rim-drive cable-aligned heliostat collector system  

SciTech Connect

Disclosed is a heliostat collector apparatus comprising at least one heliostat suspended from a plurality of longitudinally extending linkage means. An enclosure structure is disposed adjacent the heliostat and provides a means for allowing th heliostat to be substantially protected from weathering. A first drive means is operatively connected to the heliostat to effect steering thereof in at least one of first and second predetermined directions. Finally, a frame member is adapted for supporting the heliostat at an inner portion thereof. The frame includes a plurality of outer expandable portions. Each one of the expandable portions is adapted to slidably engage a corresponding one of the plurality of linkage means. The expandable portions are further adapted to allow the heliostat to be slidably moved along the linkage means in directions away from and towards the enclosure structure and to substantially reduce stress acting on the heliostat during steering.

Dolan, J.E.; Sands, T.D.

1984-08-21T23:59:59.000Z

220

Oil/gas collector/separator for underwater oil leaks  

DOE Patents (OSTI)

An oil/gas collector/separator for recovery of oil leaking, for example, from an offshore or underwater oil well. The separator is floated over the point of the leak and tethered in place so as to receive oil/gas floating, or forced under pressure, toward the water surface from either a broken or leaking oil well casing, line, or sunken ship. The separator is provided with a downwardly extending skirt to contain the oil/gas which floats or is forced upward into a dome wherein the gas is separated from the oil/water, with the gas being flared (burned) at the top of the dome, and the oil is separated from water and pumped to a point of use. Since the density of oil is less than that of water it can be easily separated from any water entering the dome.

Henning, Carl D. (Livermore, CA)

1993-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Development of a Solar Assisted Drying System Using Double-Pass Solar Collector with Finned Absorber  

Science Journals Connector (OSTI)

The Solar Energy Research Group, Universiti Kebangsaan Malaysia, International Islamic University Malaysia and Yayasan FELDA has designed and constructed a solar assisted drying system at OPF FELDA Factory, Felda Bukit Sagu 2, Kuantan, Pahang. The drying system has a total of six double-pass solar collectors. Each collector has a length of 480 cm and a width of 120 cm. The first channel depth is 3.5 cm and the second channel depth is 7 cm. Longitudinal fins made of angle aluminium, 0.8 mm thickness were attached to the bottom surface of the absorber plate. The solar collectors are arranged as two banks of three collectors each in series. Internal manifold are used to connect the collectors. Air enters through the first channel and then through the second channel of the collector. An auxiliary heater source is installed to supply heat under unfavourable solar radiation condition. An on/off controller is used to control the startup and shutdown of the auxiliary heater. An outlet temperature of 70–75 °C can be achieved at solar radiation range of 800–900 W/m2 and flow rate of 0.12 kg/s. The average thermal efficiency of a solar collector is approximately 37%.

M S M Azmi; M Y Othman; K Sopian; M H Ruslan; Z A A Majid; A Fudholi; J M Yasin

2012-01-01T23:59:59.000Z

222

Solar: monthly and annual average direct normal (DNI), global horizontal  

Open Energy Info (EERE)

East Asia from NREL East Asia from NREL Dataset Summary Description (Abstract): Monthly Average Solar Resource for horizontal and tilted flat-plates, and 2-axis tracking concentrating collectors. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to solar collectors. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The data were developed from NREL's Climatological Solar Radiation (CSR) Model. This model uses information on cloud cover, atmospheric water

223

Solar: monthly and annual average direct normal (DNI), global horizontal  

Open Energy Info (EERE)

Africa from NREL Africa from NREL Dataset Summary Description (Abstract): Monthly Average Solar Resource for horizontal and tilted flat-plates, and 2-axis tracking concentrating collectors. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to solar collectors. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The data were developed from NREL's Climatological Solar Radiation (CSR) Model. This model uses information on cloud cover, atmospheric water

224

Method of making a current collector for a sodium/sulfur battery  

DOE Patents (OSTI)

This specification is directed to a method of making a current collector for a sodium/sulfur battery. The current collector so-made is electronically conductive and resistant to corrosive attack by sulfur/polysulfide melts. The method includes the step of forming the current collector for the sodium/sulfur battery from a composite material formed of aluminum filled with electronically conductive fibers selected from the group of fibers consisting essentially of graphite fibers having a diameter up to 10 microns and silicon carbide fibers having a diameter in a range of 500--1,000 angstroms. 2 figs.

Tischer, R.P.; Winterbottom, W.L.; Wroblowa, H.S.

1987-03-10T23:59:59.000Z

225

Efficiency of a parabolic trough collector as a water heater system in Yucatán, Mexico  

Science Journals Connector (OSTI)

The performance of a parabolic trough collector (PTC) manufactured in Merida Yucatán was evaluated under the ANSI/ASHRAE 93-1986 standard. The water heating system for testing with a constant flow limited to a maximum temperature of 55 °C was built; thus the tests were at low temperatures. Using water as working fluid it was found that the maximum efficiency of the collector was 5.43% with a flow rate of 0.022?kg/s at a direct solar irradiance with incidence angle 0°. The evaluation methodology and design of the system for testing the collector is reported in this paper.

N. Rosado Hau; M. A. Escalante Soberanis

2011-01-01T23:59:59.000Z

226

EIS-0039: Motor Gasoline Deregulation and the Gasoline Tilt  

Energy.gov (U.S. Department of Energy (DOE))

The Economic Regulatory Administration developed this EIS to evaluate the environmental impacts, including social and economic impacts, that may result from either of two proposed regulatory changes: (1) the exemption of motor gasoline from the Department of Energy's Mandatory Petroleum Price and Allocation Regulations, and (2) the adoption of the gasoline tilt, a proposed regulation that would allow refiners to recover an additional amount of their total increased costs on gasoline.

227

Electrolytic/fuel cell bundles and systems including a current collector in communication with an electrode thereof  

DOE Patents (OSTI)

Electrolytic/fuel cell bundles and systems including such bundles include an electrically conductive current collector in communication with an anode or a cathode of each of a plurality of cells. A cross-sectional area of the current collector may vary in a direction generally parallel to a general direction of current flow through the current collector. The current collector may include a porous monolithic structure. At least one cell of the plurality of cells may include a current collector that surrounds an outer electrode of the cell and has at least six substantially planar exterior surfaces. The planar surfaces may extend along a length of the cell, and may abut against a substantially planar surface of a current collector of an adjacent cell. Methods for generating electricity and for performing electrolysis include flowing current through a conductive current collector having a varying cross-sectional area.

Hawkes, Grant L.; Herring, James S.; Stoots, Carl M.; O'Brien, James E.

2013-03-05T23:59:59.000Z

228

Splay and tilt energy of bipolar lipid membranes  

E-Print Network (OSTI)

Archaea organisms are able to survive in extremely aggressive environment. It is thought that such resistance, at least, in part is sustained by unique properties of archaea membrane. The membrane consists of so called bolalipids, which has two polar heads joined by two hydrocarbon chains. Thus bolalipids can exist in two conformations: i) polar heads are located at different sides of bolalipid layer, so called, O-shape; ii) polar heads are located at the same side of the layer, so called, U-shape. Both polar heads and chains are chemically different from those for conventional lipids. In the present study we develop basis for theory of elasticity of bolalipid membranes. Deformations of splay, tilt and Gaussian curvature are considered. We show that energetic contributions of tilt deformation from two surfaces of bolalipid layer are additive, as well as Gaussian curvature, while splay deformations yield a cross-term. The presence of U-shapes is taken into account in terms of the layer spontaneous curvature. Estimation of tilt modulus and possible experiments allowing to measure splay moduli are described.

Timur R. Galimzyanov; Peter I. Kuzmin; Peter Pohl; Sergey A. Akimov

2014-12-28T23:59:59.000Z

229

Solar Energy to Drive Absorption Cooling Systems Suitable for Small Building Applications  

E-Print Network (OSTI)

results and an overview of the performance of low capacity single stage and half-effect absorption cooling systems, suitable for residential and small building applications. The primary heat source is solar energy supplied from flat plate collectors...

Gomri, R.

2010-01-01T23:59:59.000Z

230

Use of Heat From, and Thermal Management of, Photovoltaics  

Science Journals Connector (OSTI)

In flat plate PV/T collectors air or water are used for heat removal. Heat removal from concentrated photovoltaic systems has been accomplished using fluids such as air and water (Royne et al. 2003; Saki et al. 1...

Brian Norton

2014-01-01T23:59:59.000Z

231

Development and modelling of a solar assisted liquid desiccant dehumidification air-conditioning system  

Science Journals Connector (OSTI)

This paper presents the development and simulation of an advanced solar assisted liquid desiccant dehumidification air-conditioning system for ... regenerator, and an array of flat plate solar collectors. The sys...

Aqeel Kareem Mohaisen; Zhenjun Ma

2014-09-01T23:59:59.000Z

232

Sunsyst — The Computer Program for Solar Energy  

Science Journals Connector (OSTI)

In order to create a design tool the development of SUNSYST started in 1979. With SUNSYST it is possible to simulate systems with flat plate solar collectors, heat — pumps, vertical duct storage systems and so...

S. Olsson

1984-01-01T23:59:59.000Z

233

Heat Pipe Performance Enhancement with Binary Mixture Fluids that Exhibit Strong Concentration Marangoni Effects  

E-Print Network (OSTI)

on a flat-plate solar heat collector with integrated solarBinary Mixture Nucleate Boiling Heat Transfer CorrelationsG.E. , 1965, “A study of heat transfer in nucleate pool

Armijo, Kenneth Miguel

2011-01-01T23:59:59.000Z

234

Analyzing the efficiency of a photovoltaic-thermal solar collector based on heat pipes  

Science Journals Connector (OSTI)

The structure of a photovoltaic/thermal solar collector based on aluminum heat pipes and ... , along with the results from analyzing its efficiency. Its optimum mode of operation is shown...

S. M. Khairnasov

2014-01-01T23:59:59.000Z

235

Next-Generation Solar Collectors for CSP, Concentrating Solar Power (Fact Sheet)  

SciTech Connect

3M Company is one of the 2012 SunShot CSP R&D awardees for their advanced collectors. This fact sheet explains the motivation, description, and impact of the project.

Not Available

2012-09-01T23:59:59.000Z

236

Conduction and convection heat transfer in composite solar collector systems with porous absorber  

Science Journals Connector (OSTI)

Steady natural convection and conduction heat transfer has been studied in composite solar collector systems. The system consists of a glazing ... bounding wall isothermal at different temperatures, two horizontal

M. Mbaye; E. Bilgen

1993-01-01T23:59:59.000Z

237

Heat power capacity of the internal source in light-transparent coatings of planar solar collectors  

Science Journals Connector (OSTI)

The results are presented of numerical determination of the heat power capacity of the internal source in light-transparent coatings of planar solar collectors; the power results from partial absorption ... of th...

R. R. Avezov; N. R. Avezova; S. L. Lutpullaev; K. A. Samiev…

2007-09-01T23:59:59.000Z

238

Performance analysis of wick-assisted heat pipe solar collector and comparison with experimental results  

Science Journals Connector (OSTI)

The performance of heat pipe solar collector is investigated theoretically and experimentally. The system employs wick-assisted heat pipe for the heat transfer from ... pipe temperature and also the thermal effic...

E. Azad

2009-03-01T23:59:59.000Z

239

Experimental investigation on system with combination of ground-source heat pump and solar collector  

Science Journals Connector (OSTI)

This paper presents the heating performance and energy distribution of a system with the combination of ground-source heat pump and solar collector or a solar-assisted ground-source heat pump system (SAGSHPS) by ...

Tao Hu ? ?; Jialing Zhu ???; Wei Zhang ? ?

2013-06-01T23:59:59.000Z

240

Critical evaluation of heat transfer coefficients applicable to solar chimney power plant collectors  

Science Journals Connector (OSTI)

A solar chimney power plant consists of a translucent collector ... and guides it into the base of a chimney at its centre. The buoyant air rises in the chimney, and electricity is generated through one or ... tu...

M. A. dos S. Bernardes; T. W. von Backström…

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Project Profile: Low-Cost Self-Cleaning Reflector Coatings for CSP Collectors  

Energy.gov (U.S. Department of Energy (DOE))

The Oak Ridge National Laboratory (ORNL), under the National Laboratory R&D competitive funding opportunity, is developing self-cleaning, optically transparent coatings that can be applied to the surfaces of heliostats and collector mirrors in concentrating solar power (CSP) systems. The coatings can help to achieve the SunShot Initiative cost goals by reducing the time and costs associated with cleaning collector and heliostat mirror surfaces and increasing the reliability and efficiency of CSP systems.

242

3X compound parabolic concentrating (CPC) solar energy collector. Final technical report  

SciTech Connect

Chamberlain engineers designed a 3X compound parabolic concentrating (CPC) collector for the subject contract. The collector is a completely housed, 105.75 x 44.75 x 10.23-inch, 240-pound unit with six each evacuated receiver assemblies, a center manifold and a one-piece glass cover. A truncated version of a CPC trough reflector system and the General Electric Company tubular evacuated receiver have been integrated with a mass producible collector design suitable for operation at 250 to 450/sup 0/F. The key criterion for optimization of the design was minimization of the cost per Btu collected annually at an operating temperature of 400/sup 0/F. The reflector is a 4.1X design truncated to a total height of 8.0 inches with a resulting actual concentration ratio of 2.6 to 1. The manifold is an insulated area housing the fluid lines which connect the six receivers in series with inlet and outlet tubes extending from one side of the collector at the center. The reflectors are polished, anodized aluminum which are shaped by the roll form process. The housing is painted, galvanized steel, and the cover glass is 3/16-inch thick tempered, low iron glass. The collector requires four slope adjustments per year for optimum effectiveness. Chamberlain produced ten 3X CPC collectors for the subject contract. Two collectors were used to evaluate assembly procedures, six were sent to the project officer in Albuquerque, New Mexico, one was sent to Argonne National Laboratory for performance testing and one remained with the Company. A manufacturing cost study was conducted to estimate limited mass production costs, explore cost reduction ideas and define tooling requirements. The final effort discussed shows the preliminary design for application of a 3X CPC solar collector system for use in the Iowa State Capitol complex.

Ballheim, R.W.

1980-04-25T23:59:59.000Z

243

Low-cost evacuated-tube solar collector. Final report  

SciTech Connect

A prototype design for an evacuated tube air cooled solar collector module has been completed. A product cost study, based on the production of 60,000 of the prototype modules per year (approx. 1,000,000 square feet annually), estimates that the module as shipped would have a cost at inventory of $7.09 to $7.40 per square foot of aperture. Computer programs were developed to predict the optical and thermal performance of the module. Antireflective coatings (porous aluminum oxide) which could be formed by spraying or dipping were demonstrated but degraded more rapidly when exposed to a high humidity ambient than acid etched films. A selective black chromium oxide multi-layered graded film was vapor deposited which had an absorptivity of about 0.9 and an emissivity of 0.03. When the film was heated to temperatures of 400/sup 0/C in a gettered vacuum for as little as 24 hours, however, irreversible changes took place both between and within coating layers which resulted in ..cap alpha.. decreasing to about 0.73 and epsilon increasing to 0.14. The product cost studies indicate that module design changes are warranted to reduce product cost prior to tooling for production.

Not Available

1981-02-10T23:59:59.000Z

244

POTATO - a program for generating perovskite structures distorted by tilting of rigid octahedra  

Science Journals Connector (OSTI)

A program that, given the tilt system, tilt angles and octahedral bond distances, will calculate the ideal crystal structure for AMO3 and A2MM'O6 perovskites distorted by octahedral tilting is presented. See the Journal of Applied Crystallography Software List 1997.

Woodward, P.M.

1997-04-01T23:59:59.000Z

245

Thermal and Hydraulic Design of a Solar Collector Field for a Primary School Pool  

Science Journals Connector (OSTI)

Abstract The methodology and results of the thermal and hydraulic design for a solar heating field of an elementary school's semi-olympic pool is presented. Improved flat solar collectors with copper tube and aluminum fins were used. From own experiences, many Mexican solar fields do not operate correctly because of their poor flow balance (irrigation), may be due to lack of attention given to this aspect. That's why the research of this work focuses on studying the behavior of the pressure drop in a hydraulic arrangement, particularly of this facility, in which all collector batteries are connected in parallel. Previously two solar collectors were sent to a specialized laboratory for certification tests, obtaining the optimum water flow value for maximum thermal efficiency. The results show an optimum range between 4 and 11 L/min. On the other hand, the development of a thermal model based on a temporal energy balance, allowed us to determine that the optimum solar heating area is around 338 m2, using 195 flat-coated solar collectors, with copper tube and aluminum fin. For this heating system a water volume/solar collection area relation, called REVA, of 1.45m3/m2 was obtained. Referred to the hydraulic design and using the program EPANET 2.0 it was found that in the proposed arrangement, 192 solar collectors were irrigated with the optimal range and only 2 solar collectors were below the lower range at 3 L/min.

Rubén Dorantes; Georgina García; Carlos Salazar; Heber Oviedo; Humberto González; Raúl Alanis; Edgar Salazar; Ignacio R. Martín-Dominguez

2014-01-01T23:59:59.000Z

246

atmoshperic water vapor | OpenEI  

Open Energy Info (EERE)

atmoshperic water vapor atmoshperic water vapor Dataset Summary Description (Abstract): Monthly Average Solar Resource for flat-plate collectors tilted at latitude for China. Source NREL Date Released April 12th, 2005 (9 years ago) Date Updated October 30th, 2007 (7 years ago) Keywords atmoshperic water vapor China GEF GIS NREL solar SWERA TILT UNEP Data application/zip icon Download Shapefile (zip, 625.6 KiB) text/csv icon Download Data (csv, 704.1 KiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period 01/01/1985 - 12/31/1991 License License Open Data Commons Public Domain Dedication and Licence (PDDL) Comment Rate this dataset Usefulness of the metadata Average vote Your vote Usefulness of the dataset Average vote Your vote Ease of access

247

Electronic properties of graphite in tilted magnetic fields  

SciTech Connect

The minimal nearest-neighbor tight-binding model with the Peierls substitution is employed to describe the electronic structure of Bernal-stacked graphite subject to tilted magnetic fields. We show that while the presence of the in-plane component of the magnetic field has a negligible effect on the Landau level structure at the K point of the graphite Brillouin zone, at the H point it leads to the experimentally observable splitting of Landau levels which grows approximately linearly with the in-plane field intensity.

Goncharuk, Nataliya A.; Smr?ka, Ludvík [Institute of Physics, Academy of Science of the Czech Republic, v. v. i., Cukrovarnická 10, 162 53 Praha 6 (Czech Republic)

2014-05-15T23:59:59.000Z

248

Climatically Diverse Data Set for Flat-Plate PV Module Model Validations (Presentation)  

SciTech Connect

Photovoltaic (PV) module I-V curves were measured at Florida, Colorado, and Oregon locations to provide data for the validation and development of models used for predicting the performance of PV modules.

Marion, B.

2013-05-01T23:59:59.000Z

249

The effect of injection hole geometry on flat plate film cooling and heat transfer  

E-Print Network (OSTI)

to thermal ly protect a gas turb ine blade f r om the hot gases w i th in a gas turbine engine by inject ion of a coo l ing f lu id th rough discrete holes i n the surface of the blade. Tests were conducted on a flat p late us ing the f i lm cool ing... surface w i th coo l ing a ir c i rculated w i th in the hol low core of the turb ine b lade. External cool ing employs co ld a ir inject ion th rough holes on the outer surface of the turb ine blade produc ing a f i lm of a i r that protects...

Madsen, Eric Perry

2012-06-07T23:59:59.000Z

250

Friction factor data for flat plate tests of smooth and honeycomb surfaces  

E-Print Network (OSTI)

plate tester assembly. The honeycomb test specimen of figure 4 is made by attaching a honeycomb plate, made of Hastelloy " x " , a Kentucky Metals Inc. product, to a precision- ground stock base plate with a 0.24 m m thickness structual adhesive f i... downstream to control back pressure. The flowrate through the test section is measured by a 1.3 cm turbine flow meter, located in the piping upstream of the test section. Resolution of the flow meter is 5 X 1 0 - 5 ( m 3 / m m ) . Pressure and temperature...

Ha, Tae Woong

2012-06-07T23:59:59.000Z

251

Flow field characteristics of a radial jet reattaching on a flat plate  

E-Print Network (OSTI)

Xp/b Figure 10. Effect. of Xp/b on Cp at. reattachment location. 38 0. 6 0. 5 0. 4 8, : 0' R, : 14700 b: 7. 5 mm Cp 0. 3 0. 2 0. 1 0. 0 0. 1 2 4 6 8 10 12 Xp/b 0. 6 0. 5 8, : 10' R, : 14700 b: 50 mm Cp 0. 3 0. 2 0. 1 0. 0 0. 1... 2 4 6 8 10 12 Xp/b I'ii, ure IO. Continned. 39 0. 6 0. 5 8, : 10' R, : 15000 b: 75 mm Cp 0. 3 0. 1 0. 0 0. 1 2 4 6 0 10 12 Xp/b 0. 6 0. 4 R, : 4800 b: 25 mm Cp 0. 3 0. 2 0. 1 0, 0 0. 1 2 4 6 6 10 12 Xp/b Rigure 10. Continued...

Carbone, Janique Sylvia

2012-06-07T23:59:59.000Z

252

An evaluation of the thermal characteristics of a flat plate heat pipe spreader  

E-Print Network (OSTI)

loss could bc determined. Duc to the axisymmetric nature of the i. echnique, it was necessary to define the effective radial heat pipe dimensions. ln the case of a disk shaped flat heat pipe, the effective radius is equal to the radius of the disk...

Chesser, Jason Blake

2000-01-01T23:59:59.000Z

253

Study of active control of instability in a boundary layer over a flat plate flow  

E-Print Network (OSTI)

A feasibility study of utilizing synthetic jet actuators as a mean to mitigate disturbances that can cause instability and turbulent flow is described. Prediction of flow transition via linear stability theory was performed by solving the Orr...

Oryu, Hiroshi

2012-06-07T23:59:59.000Z

254

Validation of Multiple Tools for Flat Plate Photovoltaic Modeling Against Measured Data  

SciTech Connect

This report expands upon a previous work by the same authors, published in the 40th IEEE Photovoltaic Specialists conference. In this validation study, comprehensive analysis is performed on nine photovoltaic systems for which NREL could obtain detailed performance data and specifications, including three utility-scale systems and six commercial scale systems. Multiple photovoltaic performance modeling tools were used to model these nine systems, and the error of each tool was analyzed compared to quality-controlled measured performance data. This study shows that, excluding identified outliers, all tools achieve annual errors within +/-8% and hourly root mean squared errors less than 7% for all systems. It is further shown using SAM that module model and irradiance input choices can change the annual error with respect to measured data by as much as 6.6% for these nine systems, although all combinations examined still fall within an annual error range of +/-8.5%. Additionally, a seasonal variation in monthly error is shown for all tools. Finally, the effects of irradiance data uncertainty and the use of default loss assumptions on annual error are explored, and two approaches to reduce the error inherent in photovoltaic modeling are proposed.

Freeman, J.; Whitmore, J.; Blair, N.; Dobos, A. P.

2014-08-01T23:59:59.000Z

255

Review of Consensus Standard Spectra for Flat Plate and Concentrating Photovoltaic Performance  

SciTech Connect

Consensus standard reference terrestrial solar spectra are used to establish nameplate ratings for photovoltaic device performance at standard reporting conditions. This report describes reference solar spectra developed in the United States and international consensus standards community which are widely accepted as of this writing (June 2011).

Myers, D.

2011-09-01T23:59:59.000Z

256

Thermal solar collector with VO2 absorber coating and thermochromic glazing – Temperature matching and triggering  

Science Journals Connector (OSTI)

Abstract Overheating is a common problem both with the use of active and passive solar energy in thermal solar energy systems and in highly glazed buildings, even in central European latitudes. In solar thermal collectors, the elevated temperatures occurring during stagnation result in reduced lifetime of the collector materials. They lead to water evaporation, glycol degradation and stresses in the collector with increasing vapor pressure. Special precautions are necessary to release this pressure; only mechanical solutions exist nowadays. The temperature of degradation of glycols is above 160–170 °C. However, it would be preferable to limit the temperature of the collector to approximately 100 °C, avoiding likewise the evaporation of the used water-glycol mixture. Additionally, the elevated temperatures lead to degradation of the materials that compose the collector, such as sealing, thermal insulation and the selective absorber coating. A new way of protecting solar thermal systems without any mechanical device (e.g. for shading or for pressure release) is proposed. A durable inorganic thermochromic material, which exhibits a change in optical properties at a transition temperature T t , is vanadium dioxide (VO2). At 68 °C, VO2 undergoes a reversible crystal structural phase transition accompanied by a strong variation in optical properties. Therefore, a dynamical switching of the thermal emittance ? th can be achieved by VO2. By doping the material with tungsten, it is possible to lower the transition temperature making it suitable as a glazing coating. The possibility of using the switch in emittance of the absorber coating in order to trigger the transition of a thermochromic coating on the glazing of the solar collector has been studied. An analytical approach yielded the required transition temperature of such a switching glazing. The fascinating optical properties of these switchable films elucidate the way towards novel intelligent thermal solar collector materials.

Antonio Paone; Mario Geiger; Rosendo Sanjines; Andreas Schüler

2014-01-01T23:59:59.000Z

257

Simulation of solar lithium bromide–water absorption cooling system with parabolic trough collector  

Science Journals Connector (OSTI)

Ahwaz is one of the sweltering cities in Iran where an enormous amount of energy is being consumed to cool residential places in a year. The aim of this research is to simulate a solar single effect lithium bromide–water absorption cooling system in Ahwaz. The solar energy is absorbed by a horizontal N–S parabolic trough collector and stored in an insulated thermal storage tank. The system has been designed to supply the cooling load of a typical house where the cooling load peak is about 17.5 kW (5 tons of refrigeration), which occurs in July. A thermodynamic model has been used to simulate the absorption cycle. The working fluid is water, which is pumped directly to the collector. The results showed that the collector mass flow rate has a negligible effect on the minimum required collector area, but it has a significant effect on the optimum capacity of the storage tank. The minimum required collector area was about 57.6 m2, which could supply the cooling loads for the sunshine hours of the design day for July. The operation of the system has also been considered after sunset by saving solar energy.

M. Mazloumi; M. Naghashzadegan; K. Javaherdeh

2008-01-01T23:59:59.000Z

258

Microelectromechanical apparatus for elevating and tilting a platform  

DOE Patents (OSTI)

A microelectromechanical (MEM) apparatus is disclosed which has a platform that can be elevated above a substrate and tilted at an arbitrary angle using a plurality of flexible members which support the platform and control its movement. Each flexible member is further controlled by one or more MEM actuators which act to bend the flexible member. The MEM actuators can be electrostatic comb actuators or vertical zip actuators, or a combination thereof. The MEM apparatus can include a mirror coating to form a programmable mirror for redirecting or switching one or more light beams for use in a projection display. The MEM apparatus with the mirror coating also has applications for switching light beams between optical fibers for use in a local area fiber optic network, or for use in fiber optic telecommunications or data communications systems.

Miller, Samuel Lee (Albuquerque, NM); McWhorter, Paul Jackson (Albuquerque, NM); Rodgers, Murray Steven (Albuquerque, NM); Sniegowski, Jeffry J. (Edgewood, NM); Barnes, Stephen M. (Albuquerque, NM)

2003-04-08T23:59:59.000Z

259

Automated solar collector installation design including ability to define heterogeneous design preferences  

DOE Patents (OSTI)

Embodiments may include systems and methods to create and edit a representation of a worksite, to create various data objects, to classify such objects as various types of pre -defined "features" with attendant properties and layout constraints. As part of or in addition to classification, an embodiment may include systems and methods to create, associate, and edit intrinsic and extrinsic properties to these objects. A design engine may apply of design rules to the features described above to generate one or more solar collectors installation design alternatives, including generation of on-screen and/or paper representations of the physical layout or arrangement of the one or more design alternatives. Embodiments may also include definition of one or more design apertures, each of which may correspond to boundaries in which solar collector layouts should comply with distinct sets of user-defined design preferences. Distinct apertures may provide heterogeneous regions of collector layout according to the user-defined design preferences.

Wayne, Gary; Frumkin, Alexander; Zaydman, Michael; Lehman, Scott; Brenner, Jules

2014-04-29T23:59:59.000Z

260

Automated solar collector installation design including ability to define heterogeneous design preferences  

DOE Patents (OSTI)

Embodiments may include systems and methods to create and edit a representation of a worksite, to create various data objects, to classify such objects as various types of pre-defined "features" with attendant properties and layout constraints. As part of or in addition to classification, an embodiment may include systems and methods to create, associate, and edit intrinsic and extrinsic properties to these objects. A design engine may apply of design rules to the features described above to generate one or more solar collectors installation design alternatives, including generation of on-screen and/or paper representations of the physical layout or arrangement of the one or more design alternatives. Embodiments may also include definition of one or more design apertures, each of which may correspond to boundaries in which solar collector layouts should comply with distinct sets of user-defined design preferences. Distinct apertures may provide heterogeneous regions of collector layout according to the user-defined design preferences.

Wayne, Gary; Frumkin, Alexander; Zaydman, Michael; Lehman, Scott; Brenner, Jules

2013-01-08T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Compendium of information on identification and testing of materials for plastic solar thermal collectors  

SciTech Connect

This report is intended to organize and summarize prior and current literature concerning the weathering, aging, durability, degradation, and testing methodologies as applied to materials for plastic solar thermal collectors. Topics covered include (1) rate of aging of polymeric materials; (2) environmental factors affecting performance; (3) evaluation and prediction of service life; (4) measurement of physical and chemical properties; (5) discussion of evaluation techniques and specific instrumentation; (6) degradation reactions and mechanisms; (7) weathering of specific polymeric materials; and (8) exposure testing methodology. Major emphasis has been placed on defining the current state of the art in plastics degradation and on identifying information that can be utilized in applying appropriate and effective aging tests for use in projecting service life of plastic solar thermal collectors. This information will also be of value where polymeric components are utilized in the construction of conventional solar collectors or any application where plastic degradation and weathering are prime factors in material selection.

McGinniss, V.D.; Sliemers, F.A.; Landstrom, D.K.; Talbert, S.G.

1980-07-31T23:59:59.000Z

262

Review of combined photovoltaic/thermal collector: solar assisted heat pump system options  

SciTech Connect

The advantages of using photovoltaic (PV) and combined photovoltaic/thermal (PV/T) collectors in conjunction with residential heat pumps are examined. The thermal and electrical power requirements of similar residences in New York City and Fort Worth are the loads under consideration. The TRNSYS energy balance program is used to simulate the operations of parallel, series, and cascade solar assisted heat pump systems. Similar work involving exclusively thermal collectors is reviewed, and the distinctions between thermal and PV/T systems are emphasized. Provided the defrost problem can be satisfactorily controlled, lifecycle cost analyses show that at both locations the optimum collector area is less than 50 m/sup 2/ and that the parallel system is preferred.

Sheldon, D.B.; Russell, M.C.

1980-01-01T23:59:59.000Z

263

Solar Collector: A Novel Way of Harnessing the Sun's Energy The team analysed the prototype and different design alternatives.The goal of the Solar Collector is to better  

E-Print Network (OSTI)

Solar Collector: A Novel Way of Harnessing the Sun's Energy Overview The team analysed the prototype and different design alternatives.The goal of the Solar Collector is to better harness the solar energy by focusing the sun's energy through a series of curved reflective fins. A challenge the team

Demirel, Melik C.

264

Effect of beam limiting aperture and collector potential on multi-element focused ion beams  

SciTech Connect

A compact microwave driven plasma based multi-element focused ion beam system has been developed. In the present work, the effect of reduced beam limiter (BL) aperture on the focused ion beam parameters, such as current and spot size, and a method of controlling beam energy independently by introducing a biased collector at focal point (FP) are investigated. It is found that the location of FP does not change due to the reduction of BL aperture. The location of FP and beam size are found to be weakly dependent on the collector potential in the range from -8 kV to -18 kV.

Paul, Samit; Chowdhury, Abhishek; Bhattacharjee, Sudeep [Department of Physics, Indian Institute of Technology, Kanpur, Uttar Pradesh (India)

2012-02-15T23:59:59.000Z

265

History, current state, and future of linear Fresnel concentrating solar collectors  

Science Journals Connector (OSTI)

Abstract Linear Fresnel collectors are a type of concentrating solar power technology. In this paper, the technology’s technical features and aspects are first described via illustrations of various design concepts; then, the past low- and intermediate-temperature applications of linear Fresnel collectors are reviewed and their state-of-the-art applications in utility-scale electricity generation are presented; finally, the performance, technical challenges, and future outlook of linear Fresnel technology in the context of utility-scale power plants are summarized.

Guangdong Zhu; Tim Wendelin; Michael J. Wagner; Chuck Kutscher

2014-01-01T23:59:59.000Z

266

RIMS analysis of Ca and Cr in genesis solar wind collectors.  

SciTech Connect

RIMS depth profiles have been measured for Cr and Ca in Genesis solar wind collector made from Si and compared to such measurements for ion-implanted Si reference material. The presence of surface contamination has been shown to be a significant factor influencing the total Ca and Cr fluence measured in the Genesis collectors. A procedure to remove the contaminant signal from these depth profiles using the reference material implanted with a minor isotope demonstrated that 36% of the measured Ca fluence in our Genesis sample comes from terrestrial contamination.

Veryovkin, I. V.; Tripa, C. E.; Zinovev, A. V.; King, B. V.; Pellin, M. J.; Burnett, D. S.; Materials Science Division; Univ. of Newcastle; California Inst. of Tech.

2011-01-01T23:59:59.000Z

267

Water-trickle type solar collector with a massive concrete slab for heat storage and radiation (TMU solar system I)  

SciTech Connect

Experimental results are reported for a simple open type solar collector - a water-trickle type collector - used in combination with a massive concrete slab for energy storage. This relatively low cost system was installed on a typical Japanese house in Yokohama City and measurements were made of the interior temperature. The system showed considerable promise for application in Japan.

Ito, N. (Tokyo Metropolitan Univ., Japan); Matsuda, K.; Ishii, A.; Osawa, H.

1980-01-01T23:59:59.000Z

268

Enhanced electrochemical performance of sulfur cathode by incorporation of a thin conductive adhesion layer between the current collector and the active material layer  

Science Journals Connector (OSTI)

In the typical electrode configuration, the active material layer is directly supported on a metallic ... collector. The interface between current collector and active material layer imposes additional charge tra...

Zhian Zhang; Zhiyong Zhang; Xiwen Wang; Jie Li…

2014-05-01T23:59:59.000Z

269

Precision tip-tilt-piston actuator that provides exact constraint  

DOE Patents (OSTI)

A precision device which can precisely actuate three degrees of freedom of an optic mount, commonly referred to as tip, tilt, and piston. The device consists of three identical flexure mechanisms, an optic mount to be supported and positioned, a structure that supports the flexure mechanisms, and three commercially available linear actuators. The advantages of the precision device is in the arrangement of the constraints offered by the flexure mechanism and not in the particular design of the flexure mechanisms, as other types of mechanisms could be substituted. Each flexure mechanism constrains two degrees of freedom in the plane of the mechanisms and one direction is actuated. All other degrees of freedom are free to move within the range of flexure mechanisms. Typically, three flexure mechanisms are equally spaced in angle about to optic mount and arranged so that each actuated degree of freedom is perpendicular to the plane formed by the optic mount. This arrangement exactly constrains the optic mount and allows arbitrary actuated movement of the plane within the range of the flexure mechanisms. Each flexure mechanism provides a mechanical advantage, typically on the order of 5:1, between the commercially available actuator and the functional point on the optic mount. This improves resolution by the same ratio and stiffness by the square of the ratio.

Hale, Layton C. (Livermore, CA)

1999-01-01T23:59:59.000Z

270

Heat Transfer in Buildings: Application to Solar Air Collector and Trombe Wall Design  

E-Print Network (OSTI)

11 Heat Transfer in Buildings: Application to Solar Air Collector and Trombe Wall Design H. Boyer focuses on the modeling of Trombe solar walls. In each case, detailed modeling of heat transfer allows with same thermal behaviour). For heat conduction in walls, it results from electrical analogy

Paris-Sud XI, Université de

271

Analysis of a Possible 20A Electron Gun and Collector Design for the RHIC EBIS  

E-Print Network (OSTI)

Analysis of a Possible 20A Electron Gun and Collector Design for the RHIC EBIS Alexander Pikin of electron beam generation with the gun immersed in a magnetic field and subsequent purely magnetic compression of the electron beam, it makes sense to develop the new electron gun with immersed cathode

272

Solar heat collectors. (Latest citations from the US Patent database). Published Search  

SciTech Connect

The bibliography contains selected patents concerning solar heat collector apparatus and systems. Building panels, air conditioning systems, chemical heat pumps, refrigeration systems, and controls are discussed. Applications include residential and commercial building space and water heating, greenhouse heating, and swimming pool heating. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1993-07-01T23:59:59.000Z

273

Collector surface for a microwave tube comprising a carbon-bonded carbon-fiber composite  

DOE Patents (OSTI)

In a microwave tube, an improved collector surface coating comprises a porous carbon composite material, preferably a carbon-bonded carbon fiber composite having a bulk density less than about 2 g/cc. Installation of the coating is readily adaptable as part of the tube manufacturing process.

Lauf, Robert J. (Oak Ridge, TN); McMillan, April D. (Knoxville, TN); Johnson, Arvid C. (Lake in the Hills, IL); Moorhead, Arthur J. (Knoxville, TN)

1998-01-01T23:59:59.000Z

274

Collector surface for a microwave tube comprising a carbon-bonded carbon-fiber composite  

DOE Patents (OSTI)

In a microwave tube, an improved collector surface coating comprises a porous carbon composite material, preferably a carbon-bonded carbon fiber composite having a bulk density less than about 2 g/cc. Installation of the coating is readily adaptable as part of the tube manufacturing process. 4 figs.

Lauf, R.J.; McMillan, A.D.; Johnson, A.C.; Moorhead, A.J.

1998-07-28T23:59:59.000Z

275

Performance Analysis of a Thermoelectric Solar Collector Integrated with a Heat Pump  

Science Journals Connector (OSTI)

A novel heat pump system is proposed. A thermoelectric solar collector was coupled to a solar-assisted heat pump (TESC-HP) to work as an ... ambient temperature of 32.5°C and average solar intensity of 815 W/m2, ...

C. Lertsatitthanakorn; J. Jamradloedluk; M. Rungsiyopas…

2013-07-01T23:59:59.000Z

276

The role of tilted heating in the evolution of the MJO Cara-Lyn Lappen1  

E-Print Network (OSTI)

The role of tilted heating in the evolution of the MJO Cara-Lyn Lappen1 and Courtney Schumacher2 1 the role of tilted heating in the evolution of the MJO. It is believed that the inability of many general heating distributions. Given the MJO's importance in tropical climate, we need to better understand what

277

Head tilt during driving DANIEL C. ZIKOVITZ and LAURENCE R. HARRIS *  

E-Print Network (OSTI)

Head tilt during driving DANIEL C. ZIKOVITZ ² and LAURENCE R. HARRIS² * Departments of ² Biology and Psychology, York University, Toronto, Ontario M3J 1P3, Canada Keywords: Driving behaviour; Head tilt; Vision with the visually-available estimate of the curvature of the road (r 2 = 0.86) but not with the centripetal force (r

Harris, Laurence R.

278

Self-Optimization of Antenna Tilt and Pilot Power for Dedicated Channels  

E-Print Network (OSTI)

Self-Optimization of Antenna Tilt and Pilot Power for Dedicated Channels Abstract-- In Radio Access Networks (RAN), fixed configurations result in poor network efficiency. This sub- optimal performance present a framework for a self-optimizing RAN, which adapts Antenna Tilt and Pilot Power according

Paris-Sud XI, Université de

279

The Tilt of the Leading Edge of Mesoscale Tropical Convective Lines  

Science Journals Connector (OSTI)

The tilt with height of the leading edge of seven mesoscale convective lines in GATE is determined by two independent methods. When averaged over time and along the line axis, the tilt is found to he surprisingly shallow, between 20 and 35 ...

M. A. LeMone; G. M. Barnes; E. J. Szoke; E. J. Zipser

1984-03-01T23:59:59.000Z

280

Final test results for the Schott HCE on a LS-2 collector.  

SciTech Connect

Sandia National Laboratories has completed thermal performance testing on the Schott parabolic trough receiver using the LS-2 collector on the Sandia rotating platform at the National Solar Thermal Test Facility in Albuquerque, NM. This testing was funded as part of the US DOE Sun-Lab USA-Trough program. The receiver tested was a new Schott receiver, known as Heat Collector Elements (HCEs). Schott is a new manufacturer of trough HCEs. The Schott HCEs are 4m long; therefore, two were joined and mounted on the LS-2 collector module for the test. The Schott HCE design consists of a 70mm diameter high solar absorptance coated stainless steel (SS) tube encapsulated within a 125mm diameter Pyrex{reg_sign} glass tube with vacuum in the annulus formed between the SS and glass tube to minimize convection heat losses. The Schott HCE design is unique in two regards. First, the bellows used to compensate for the difference in thermal expansion between the metal and glass tube are inside the glass envelope rather than outside. Second, the composition of materials at the glass-to-metal seal has very similar thermal expansion coefficients making the joint less prone to breakage from thermal shock. Sandia National Laboratories provided both the azimuth and elevation collector module tracking systems used during the tests. The test results showed the efficiency of the Schott HCE to be very similar to current HCEs being manufactured by Solel. This testing provided performance verification for the use of Schott tubes with Solargenix trough collector assemblies at currently planned trough power plant projects in Arizona and Nevada.

Moss, Timothy A.; Brosseau, Douglas A.

2005-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

ASHMET: a computer code for estimating insolation incident on tilted surfaces  

SciTech Connect

A computer code, ASHMET, has been developed by MSFC to estimate the amount of solar insolation incident on the surfaces of solar collectors. Both tracking and fixed-position collectors have been included. Climatological data for 248 US locations are built into the code. This report describes the methodology of the code, and its input and output. The basic methodology used by ASHMET is the ASHRAE clear-day insolation relationships modified by a clearness index derived from SOLMET-measured solar radiation data to a horizontal surface.

Elkin, R.F.; Toelle, R.G.

1980-05-01T23:59:59.000Z

282

Design and development of a 329-segment tip-tilt piston mirror array for space-based adaptive optics  

E-Print Network (OSTI)

Design and development of a 329-segment tip-tilt piston mirror array for space-based adaptive. It consists of 329-hexagonal segments on a 600 m pitch, each with tip/tilt and piston degrees of freedom

283

Development of a Fast Time-Resolved Aerosol Collector (Fast TRAC)  

NLE Websites -- All DOE Office Websites (Extended Search)

Yu Yu & James Cowin PNNL Fast Time-Resolved Aerosol Collector ......Fast TRAC...... Xiao-Ying Yu, Ali Hashim, Martin Iedema, and James Cowin Atmospheric Sciences, Chemical Sciences Pacific Northwest National Laboratory Richland, WA Research is supported by NOAA & DOE. *Patent Pending Xiao-Ying Yu & James Cowin PNNL Cloud Microstructures ≤ 1 m Want to know the aerosols at this resolution Aircraft flies at 150 m/s Need time resolution 1 m/150 m/s = 6 ms (!!!!!) Xiao-Ying Yu & James Cowin PNNL What is TRAC? - Time-Resolved Aerosol Collector * Uses an impactor * ~ 600 TEM samples * Flow rate: 1 l/min * Time resolution: ≥ 1 min* * Applications: Off-line analysis: - particle hygroscopicity, morphology, composition.. (6.5 in) 3 , 7 lb, 12 V, 8 W 0% 20% 40% 60%

284

Discovery of Non-random Spatial Distribution of Impacts in the Stardust Cometary Collector  

SciTech Connect

We report the discovery that impacts in the Stardust cometary collector are not distributed randomly in the collecting media, but appear to be clustered on scales smaller than {approx} 10 cm. We also report the discovery of at least two populations of oblique tracks. We evaluated several hypotheses that could explain the observations. No hypothesis was consistent with all the observations, but the preponderance of evidence points toward at least one impact on the central Whipple shield of the spacecraft as the origin of both clustering and low-angle oblique tracks. High-angle oblique tracks unambiguously originate from a non-cometary impact on the spacecraft bus just forward of the collector.

Westphal, A J; Bastien, R K; Borg, J; Bridges, J; Brownlee, D E; Burchell, M J; Cheng, A F; Clark, B C; Djouadi, Z; Floss, C; Franchi, I; Gainsforth, Z; Graham, G; Green, S F; Heck, P R; Horanyi, M; Hoppe, P; Horz, F P; Huth, J; Kearsley, A; Leroux, H; Marhas, K; Nakamura-Messenger, K; Sandford, S A; See, T H; Stadermann, F J; Teslich, N E; Tsitrin, S; Warren, J L; Wozniakiewicz, P J; Zolensky, M E

2007-04-06T23:59:59.000Z

285

Advanced Lithium Battery Cathodes Using Dispersed Carbon Fibers as the Current Collector  

SciTech Connect

To fabricate LiFePO4 battery cathodes, highly conductive carbon fibers of 10-20 m in diameter have been used to replace a conventional aluminum (Al) foil current collector. This disperses the current collector throughout the cathode sheet and increases the contact area with the LiFePO4 (LFP) particles. In addition, the usual organic binder plus carbon-black can be replaced by a high temperature binder of <5 weight % carbonized petroleum pitch (P-pitch). Together these replacements increase the specific energy density and energy per unit area of the electrode. Details of the coating procedure, characterization and approach for maximizing the energy density are discussed. In a side-by-side comparison with conventional cathodes sheets of LFP on Al foil, the carbon fiber composite cathodes have a longer cycle life, higher thermal stability, and high capacity utilization with little sacrifice of the rate performance.

Martha, Surendra K [ORNL; Kiggans, Jim [ORNL; Nanda, Jagjit [ORNL; Dudney, Nancy J [ORNL

2011-01-01T23:59:59.000Z

286

Aerogel Keystones: Extraction Of Complete Hypervelocity Impact Events From Aerogel Collectors  

SciTech Connect

In January 2006, the Stardust mission will return the first samples from a solid solar-system body since Apollo, and the first samples of contemporary interstellar dust ever collected. Although sophisticated laboratory instruments exist for the analysis of Stardust samples, techniques for the recovery of particles and particle residues from aerogel collectors remain primitive. Here we describe our recent progress in developing techniques for extracting small volumes of aerogel, which we have called ''keystones,'' which completely contain particle impacts but minimize the damage to the surrounding aerogel collector. These keystones can be fixed to custom-designed micromachined silicon fixtures (so-called ''microforklifts''). In this configuration the samples are self-supporting, which can be advantageous in situations in which interference from a supporting substrate is undesirable. The keystones may also be extracted and placed onto a substrate without a fixture. We have also demonstrated the capability of homologously crushing these unmounted keystones for analysis techniques which demand flat samples.

Westphal, A J; Snead, C; Butterworth, A; Graham, G A; Bradley, J; Bajt, S; Grant, P G; Bench, G; Brennan, S; Piannetta, P

2003-11-07T23:59:59.000Z

287

Heat efficiency of “translucent cover-radiation absorbing heat-exchange panel” system of flat solar collectors  

Science Journals Connector (OSTI)

An analytic expression is proposed for determining the heat efficiency of the “translucent cover-radiation absorbing heat-exchange panel” system of flat solar collectors, and on its base the heat efficiency of th...

R. R. Avezov; N. R. Avezova

2008-09-01T23:59:59.000Z

288

Management and exploitation of direct normal irradiance resources for concentrating solar collectors: Algeria as a case study  

Science Journals Connector (OSTI)

The use of concentrating solar collectors which are used in solar thermal power plant and concentrated photovoltaic systems implies that these systems only work with the direct normal irradiance (DNI). Unfortu...

Mohamed Salah Mecibah; Taqiy Eddine Boukelia…

2014-11-01T23:59:59.000Z

289

Dynamic Performance Study on the Solar Collector/Evaporator of Direct Expansion Solar Assisted Heat Pump Systems  

Science Journals Connector (OSTI)

A dynamic simulation model is developed for predicting performance of the solar collector/evaporator of direct expansion solar assisted heat pump systems. In this model, ... meteorological and configuration param...

Li Hong; Yang Hongxing

2009-01-01T23:59:59.000Z

290

Unglazed transpired solar collector having a low thermal-conductance absorber  

DOE Patents (OSTI)

An unglazed transpired solar collector using solar radiation to heat incoming air for distribution, comprises an unglazed absorber formed of low thermal-conductance material having a front surface for receiving the solar radiation and openings in the unglazed absorber for passage of the incoming air such that the incoming air is heated as it passes towards the front surface of the absorber and the heated air passes through the openings in the absorber for distribution. 3 figs.

Christensen, C.B.; Kutscher, C.F.; Gawlik, K.M.

1997-12-02T23:59:59.000Z

291

Unglazed transpired solar collector having a low thermal-conductance absorber  

DOE Patents (OSTI)

An unglazed transpired solar collector using solar radiation to heat incoming air for distribution, comprising an unglazed absorber formed of low thermal-conductance material having a front surface for receiving the solar radiation and openings in the unglazed absorber for passage of the incoming air such that the incoming air is heated as it passes towards the front surface of the absorber and the heated air passes through the openings in the absorber for distribution.

Christensen, Craig B. (Boulder, CO); Kutscher, Charles F. (Golden, CO); Gawlik, Keith M. (Boulder, CO)

1997-01-01T23:59:59.000Z

292

Study of ice and snow melting process on conductive asphalt solar collector  

Science Journals Connector (OSTI)

This paper investigates the snow melting process on asphalt pavements as solar collector by experiments and numerical simulation. A numerical simulation method was used to predict the general design requirements for snow melting system of asphalt pavements, and a type of experimental asphalt snow melting system has been built using the design parameters obtained from the preceding simulation. Graphite powders were used to improve the thermal conductivity of asphalt concrete and thus resulting in an improved efficiency of asphalt collector. A laboratory snow melting test was performed after real snowstorm events. The effects of thermal conductive asphalt concrete (CAC) on snow melting performance and asphalt pavement temperature distribution were evaluated. The heat transfer in the asphalt slabs and the heat requirement for the snow melting were analyzed. The results that are obtained show that asphalt solar collector (ASC) provides us a better alternative method for snow melting. The higher fluid temperature is a positive way to improve the performance of snow melting system. However, it is unnecessary to keep a too high fluid temperature so as to reduce the waste of energy. The non-uniform temperatures in the asphalt slabs are noticeable. Furthermore, the heat-transmission and the snow melting performance can be enhanced using CAC.

Mingyu Chen; Shaopeng Wu; Hong Wang; Jizhe Zhang

2011-01-01T23:59:59.000Z

293

Performance of a double-effect absorption chiller driven by ICPC solar collectors  

SciTech Connect

This paper presents experimental data and analytical results describing the performance of a 70 kW (20 ton), water-fired, double-effect absorption chiller. The chiller is driven by a 106 m{sup 2} array of integrated compound parabolic concentrator (ICPC) solar collectors. For this project, an existing gas-fired chiller was modified to operate on hot water. The water was heated by an array of 336 evacuated ICPC tubes. Each tube has an effective area of 0.317 m{sup 2}. The chiller and collector array are part of a complete solar HVAC system that provides air conditioning and space heating for a 743 m{sup 2} (8,000 ft{sup 2}) commercial building in Sacramento, CA. The other components of the HVAC system are a high temperature storage tank, a cooling tower, a gas-fired back-up boiler and five 14 kW (4 ton) cooling/heating fan coil units. The experimental data are used to determine; (1) the efficiency of the collectors; (2) the coefficient of performance of the chiller; and (3) the overall energy balance on the system. Computer models have also been developed to predict the performance and to optimize the design and operating characteristics of the HVAC system.

Bergquam, J.B.; Duff, W.S.; Brezner, J.M.; Henkel, E.T.; Winston, R.; O'Gallagher, J.; Sethi, P.

1999-07-01T23:59:59.000Z

294

Concentrating-collector mass-production feasibility. Volume I. Final report  

SciTech Connect

The Performance Prototype Trough (PPT) Concentrating Collector consists of four 80-foot modules in a 320-foot row. The collector was analyzed, including cost estimates and manufacturing processes to produce collectors in volumes from 100 to 100,000 modules per year. The four different reflector concepts considered were the sandwich reflector structure, sheet metal reflector structure, molded reflector structure, and glass laminate structure. The sheet metal and glass laminate structures are emphasized with their related structure concepts. A preliminary manufacturing plan is offered that includes: documentation of the manufacturing process with production flow diagrams; labor and material costs at various production levels; machinery and equipment requirements including preliminary design specifications; and capital investment costs for a new plant. Of five reflector designs considered, the two judged best and considered at length are thin annealed glass and steel laminate on steel frame panel and thermally sagged glass. Also discussed are market considerations, costing and selling price estimates, design cost analysis and make/buy analysis. (LEW)

Not Available

1981-11-02T23:59:59.000Z

295

Emitter tests in an open thermionic converter with vapor injection through the collector  

SciTech Connect

Mo and Pt emitters and a Ni collector with 400 laser-bored holes were used in an ''open'' thermionic converter. The alkali vapor was introduced into the converter through the array of holes in the collector from an adjacent alkali metal reservoir with separately controlled temperature. The overall results from the open thermionic converter are comparable to results from enclosed converters. The results found with a Cs plasma are encouraging, with barrier indices down to below 1.8 eV, at emitter temperatures around 1500 K in the case of a Mo emitter. The output power density was around 3.5 W cm/sup -2/. In the case of a Pt emitter, both Cs and K plasmas were used, with power densities up to 5.7 and 1.8 W cm/sup -2/, respectively close to 1800 K. The structure of the laser-bored collector may have contributed to these results, as well as the efficient removal of impurities in the ''open'' converter.

Wriedt, S.; Moeller, K.; Holmlid, L.

1986-12-15T23:59:59.000Z

296

Development of a new flat stationary evacuated CPC-collector for process heat applications  

SciTech Connect

For the economical supply of solar process heat at temperatures between 120 and 150 C a new non-tracking, flat, low-concentrating collector has been developed. The new collector is an edge ray collector with a concentration of 1.8 and inert gas filling, existing of parallel mounted absorber-reflector units, aligned in east-west direction. The basic concept is the integration of an absorber tube and reflectors inside a low pressure enclosure. Asymmetrical reflectors below the headers with a concentration of 0.6X provide extra radiation and prevent longitudinal radiation losses. To suppress heat losses due to gas-convection inside, air or inert gas like krypton at a pressure below 10 mbar is used. A prototype, with an aperture area of 2.0 m{sup 2}, was tested in Munich and showed efficiencies of about 50% for krypton at 0.01 bar at a temperature of 150 C with a radiation of 1000 W/m{sup 2} (900 W/m{sup 2} direct, ambient temperature 20 C). (author)

Buttinger, Frank; Beikircher, Thomas; Proell, Markus; Schoelkopf, Wolfgang [Bavarian Center for Applied Energy Research (ZAE Bayern), Technology for Energy Systems and Renewable Energies, Walther-Meissner-Str. 6, 85748 Garching (Germany)

2010-07-15T23:59:59.000Z

297

Copper corrosion and its relationship to solar collectors:a compendium.  

SciTech Connect

Copper has many fine qualities that make it a useful material. It is highly conductive of both heat and electricity, is ductile and workable, and reasonably resistant to corrosion. Because of these advantages, the solar water heating industry has been using it since the mid-1970s as the material of choice for collectors, the fundamental component of a solar water heating system. In most cases copper has performed flawlessly, but in some situations it has been known to fail. Pitting corrosion is the usual failure mode, but erosion can also occur. In 2000 Sandia National Laboratories and the Copper Development Association were asked to analyze the appearance of pin-hole leaks in solar collector units installed in a housing development in Arizona, and in 2002 Sandia analyzed a pitting corrosion event that destroyed a collector system at Camp Pendleton. This report includes copies of the reports and accounts of these corrosion failures, and provides a bibliography with references to many papers and articles that might be of benefit to the solar community. It consolidates in a single source information that has been accumulated at Sandia relative to copper corrosion, especially as it relates to solar water heaters.

Menicucci, David F.; Mahoney, Alan Roderick

2007-07-01T23:59:59.000Z

298

Proto-CIRCUS Tilted-Coil Tokamak-Torsatron Hybrid: Design and Construction  

E-Print Network (OSTI)

We present the field-line modeling, design and construction of a prototype circular-coil tokamak-torsatron hybrid called Proto-CIRCUS. The device has a major radius R = 16 cm and minor radius a tokamak, but they are tilted. This, combined with induced or driven plasma current, is expected to generate rotational transform, as seen in field-line tracing and equilibrium calculations. The device is expected to operate at lower plasma current than a tokamak of comparable size and magnetic field, which might have interesting implications for disruptions and steady-state operation. Additionally, the toroidal magnetic ripple is less pronounced than in an equivalent tokamak in which the coils are not tilted. The tilted coils are interlocked, resulting in a relatively low aspect ratio, and can be moved, both radially and in tilt angle, between discharges. This capability will be exploited for detailed comparisons between calculations and field-line mapping me...

Clark, A W; Hammond, K C; Kornbluth, Y; Spong, D A; Sweeney, R; Volpe, F A

2014-01-01T23:59:59.000Z

299

Tilt-up concrete panels : an investigation of flexural stresses and punching shear during lifting  

E-Print Network (OSTI)

Tilt-up construction is becoming more popular in the United States due to its ease of construction, reliability, and relatively low construction and maintenance costs. In its most typical form, a concrete panel is cast on ...

Bono, Matthew P. (Matthew Paul)

2011-01-01T23:59:59.000Z

300

Stacking-velocity inversion with borehole constraints for tilted TI media Xiaoxiang Wang1  

E-Print Network (OSTI)

- ing an accurate anisotropic velocity model remains a challenging problem. For TI models, transverse isotropy with a tilted symmetry axis TTI is an ap- propriate model for dipping shale layers near

Tsvankin, Ilya

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

A Novel Computational Model for Tilting Pad Journal Bearings with Soft Pivot Stiffnesses  

E-Print Network (OSTI)

A novel tilting pad journal bearing model including pivot flexibility as well as temporal fluid inertia effects on the thin film fluid flow aims to accurately predict the bearing forced performance. The predictive model also accounts for the thermal...

Tao, Yujiao 1988-

2012-12-10T23:59:59.000Z

302

Rotordynamic and thermal analyses of compliant flexure pivot tilting pad gas bearings  

E-Print Network (OSTI)

-free micro turbomachinery. The pad radial compliance was for accommodation of large rotor growth at high speeds. Parametric studies on pivot offset, preload, and tilting stiffness were performed using non-linear orbit simulations and coast-down simulations...

Sim, Kyu-Ho

2009-05-15T23:59:59.000Z

303

An alternative methodology to treat solar radiation data for the optical efficiency estimate of different types of collectors  

Science Journals Connector (OSTI)

Abstract An alternative methodology to calculate the yearly optical efficiency of a generic solar power collector/converter for any chosen location is here proposed. The innovation is in considering the yearly direct normal irradiation (DNI) not as a series of temporal data with hourly or minute resolution, but rather, as a map of physical positions assumed by the sun during the year in the sky vault. A MATLAB® suite was developed to convert the temporal DNI information, which is usually available for a chosen location, into spatial DNI information. The suite allows creating a yearly direct solar irradiation density map as function of a generic pair of independent angular coordinates (e.g., azimuth and zenith). The yearly DNI density map can then easily be multiplied by the collector efficiency map to obtain its yearly optical efficiency. The main advantages of the proposed approach compared to conventional temporal ones are (i) reduced magnitude of computational effort, and (ii) ease in conducting collector optical optimization. The approach is tested on three cases—a generic flat collector and two linear collectors—to show its generality and potentialities. The developed methodology is applied to optimize the yearly optical efficiency of a linear Fresnel collector with different orientations and mirror layouts.

Marco Binotti; Giampaolo Manzolini; Guangdong Zhu

2014-01-01T23:59:59.000Z

304

Assess the Efficacy of an Aerial Distant Observer Tool Capable of Rapid Analysis of Large Sections of Collector Fields: FY 2008 CSP Milestone Report, September 2008  

SciTech Connect

We assessed the feasibility of developing an aerial Distant Observer optical characterization tool for collector fields in concentrating solar power plants.

Jorgensen, G.; Burkholder, F.; Gray, A.; Wendelin, T.

2009-02-01T23:59:59.000Z

305

Standard test method for isotopic abundance analysis of uranium hexa?uoride and uranyl nitrate solutions by multi-collector, inductively coupled plasma-mass spectrometry  

E-Print Network (OSTI)

Standard test method for isotopic abundance analysis of uranium hexa?uoride and uranyl nitrate solutions by multi-collector, inductively coupled plasma-mass spectrometry

American Society for Testing and Materials. Philadelphia

2008-01-01T23:59:59.000Z

306

Solar: annual and seasonal average latitude tilt GIS data (contours) for  

Open Energy Info (EERE)

latitude tilt GIS data (contours) for latitude tilt GIS data (contours) for Brazil from INPE and LABSOLAR Dataset Summary Description (Abstract): Annual and seasonal mean of Latitude Tilt Solar Radiation in kWh/m2/day based on data from 1995 to 2002 (Purpose): To provide a set of consistent, reliable, verifiable, and accessible global data sets for international and in-country investors and other stakeholders (Supplemental Information): The cross-calibration process worked with data from 3 ground stations: Caicó (located in the Northeast of Brazil), Florianópolis (located in the South) and Balbina (located in Amazonia). These data have been used for validation and comparison of radiation transfer models operated in SWERA to estimate the incidence of solar radiation on the surface of the country from satellite images

307

Solar collector  

SciTech Connect

A solar energy water heating unit is provided which heats water from a swimming pool by passing the water through a series of spiral hoses mounted on a supporting surface. The supporting surface is mounted on a platform raised from the ground and is cone-shaped to allow for at least a portion of each hose line to be exposed to the sun at all times of the day. The spiral hose lines are mounted in spiral grooves provided on the supporting surface. A pump pumps the water from the swimming pool to the inlet of the hose lines, which inlet is adjacent the lowermost edge of the supporting surface so that the water is always pumped upwardly to the outlet end of the hose lines adjacent the apex of the supporting surface.

Miller, R.L.

1983-05-31T23:59:59.000Z

308

File:SWERA-203.pdf | Open Energy Information  

Open Energy Info (EERE)

latitude tilt GIS data at 40km for Sri Lanka from NREL latitude tilt GIS data at 40km for Sri Lanka from NREL Size of this preview: 776 × 600 pixels. Full resolution ‎(1,650 × 1,275 pixels, file size: 861 KB, MIME type: application/pdf) Title Monthly Average Solar Resource for flat-plate collectors tilted at latitude for Sri Lanka. Description Solar: monthly and annual average latitude tilt GIS data at 40km for Sri Lanka from NREL Sources National Renewable Energy Laboratory Related Technologies Solar Creation Date 2004-07-01 Extent International Countries Sri Lanka UN Region Southern Asia External links http://swera.unep.net/index.php?id=35&idx=203 File history Click on a date/time to view the file as it appeared at that time. Date/Time Thumbnail Dimensions User Comment current 12:25, 29 December 2010 Thumbnail for version as of 12:25, 29 December 2010 1,650 × 1,275 (861 KB) MapBot (Talk | contribs) Automated bot upload

309

Experimental investigation of line-tying effects on the spheromak tilt mode  

Science Journals Connector (OSTI)

In the absence of close fitting walls or conducting elements, the spheromak plasma configuration is unstable to at least one global MHD mode (tilting or shifting). Previous theoretical work suggested that line-tying effects could play a role in slowing down these modes. Line-tying was investigated in the Proto S-1/C spheromak device by a direct measurement of the line-tying character of the perturbed current within a passive stabilizer. The ring model of tilting is extended to include line-tying stabilization by taking into account the plasma sheath resistance. Comparison with experimental results show good agreement between predicted and observed growth rates.

F.J. Wysocki

1987-01-01T23:59:59.000Z

310

The effect of cerium surface treated ferritic stainless steel current collectors on the performance of solid oxide fuel cells (SOFC)  

Science Journals Connector (OSTI)

Laboratory scale solid oxide fuel cells (“button” cells) were operated with untreated or cerium surface treated Fe–22Cr–0.5Mn (composition by weight percent, wt%) ferritic stainless steel current collectors attached to the cathode. After a brief stabilization (or “burn-in”) period, the power density of a cell with the untreated current collector rapidly decreased. By contrast, there was little degradation in power density during testing of cells with the cerium surface treated current collectors. The difference in degradation was attributed to differences in Cr build-up within the cathode. It should be emphasized that the duration of the tests were quite short and longer duration testing is required, however, this initial assessment indicates the treatment may benefit the performance of SOFC with steel interconnects.

D.E. Alman; C.D. Johnson; W.K. Collins; P.D. Jablonski

2007-01-01T23:59:59.000Z

311

Performance analysis of a solar-assisted heat pump with an evacuated tubular collector for domestic heating  

Science Journals Connector (OSTI)

Performance of a solar-assisted heat pump with an evacuated tubular collector has been analyzed both theoretically and experimentally. A domestic heating system has been designed, constructed and tested. The evacuated tubular solar collector has been used to achieve higher collector efficiencies. The effects of evaporation temperature on the heating capacity and performance of the system have been investigated. Evaporation temperature varies between 5.2 and 20.7 °C while storage tank temperature varies between 9 and 35 °C. The maximum value of the coefficient of performance of the solar assisted heat pump is obtained as 6.38 experimentally. The calculated and experimental results are seen to be in a good agreement. A cost analysis of the proposed system is made comparing with a non-solar heat pump system.

Ahmet Ça?lar; Cemil Yamal?

2012-01-01T23:59:59.000Z

312

Application of a solar desiccant/collector system for water recovery from atmospheric air  

Science Journals Connector (OSTI)

An integrated desiccant/solar collector system for production of fresh water from atmospheric air is described. The solar driven system provided about 1.5 l of fresh water per square meter per day. The system involves the absorption of water vapor from ambient air during the night and simultaneous desiccant regeneration and water vapor condensation during the day. To enhance the mass transfer surface, a thick corrugated layer of cloth was used as a bed to carry the liquid absorbent. In the nocturnal phase of operation, air is allowed to penetrate the desiccant bed. The airflow is driven by fans supported on one side of the desiccant/solar collector unit. In this study, the effects of different parameters on the absorption and regeneration processes are discussed, and operational conditions for the proposed equipment evaluated. Radiation intensity, ambient temperature, bed temperature and temperature of the glass surface were recorded. Also, the productivity of the system during the day and under the given operation conditions was plotted. A mathematical model was prepared and its output compared with the analyzed experimental data.

H.E Gad; A.M Hamed; I.I El-Sharkawy

2001-01-01T23:59:59.000Z

313

Research on the compensation of the end loss effect for parabolic trough solar collectors  

Science Journals Connector (OSTI)

Abstract In this paper, an optical analysis on the end loss effect of parabolic trough solar collector (PTC) with horizontal north–south axis (PTC-HNSA) is performed, and a method to compensate its end loss effect is presented. The calculation formulae for the optical end loss ratio and the increased optical efficiency (the optical collection efficiency increment of PTC system after this compensation method is used) are derived; the daily optical end loss ratio, yearly optical end loss ratio, daily increased optical efficiency and yearly increased optical efficiency in different latitudes are calculated; the variation of optical end loss ratio and increased optical efficiency with trough’s length and latitude angles are analyzed and discussed. It is indicated through the analyses that this compensation method is very applicable for regions with the latitude over 25° (especially over 30°) and short trough collectors. In order to verify the feasibility of the compensation method, a five-meter PTC-HNSA experimental system was built. The increased thermal efficiency of the experimental system is measured, and the result that the experimental value (increased thermal efficiency) substantially agreed with the theoretical value (increased optical efficiency) is gained. All these works can offer some valuable references to the further study on high-efficiency trough solar concentrating systems.

Chengmu Xu; Zhiping Chen; Ming Li; Peng Zhang; Xu Ji; Xi Luo; Jiangtao Liu

2014-01-01T23:59:59.000Z

314

DEMONSTRATION OF A FULL-SCALE RETROFIT OF THE ADVANCED HYBRID PARTICULATE COLLECTOR TECHNOLOGY  

SciTech Connect

The Advanced Hybrid Particulate Collector (AHPC), developed in cooperation between W.L. Gore & Associates and the Energy & Environmental Research Center (EERC), is an innovative approach to removing particulates from power plant flue gas. The AHPC combines the elements of a traditional baghouse and electrostatic precipitator (ESP) into one device to achieve increased particulate collection efficiency. As part of the Power Plant Improvement Initiative (PPII), this project was demonstrated under joint sponsorship from the U.S. Department of Energy and Otter Tail Power Company. The EERC is the patent holder for the technology, and W.L. Gore & Associates was the exclusive licensee for this project. The project objective was to demonstrate the improved particulate collection efficiency obtained by a full-scale retrofit of the AHPC to an existing electrostatic precipitator. The full-scale retrofit was installed on an electric power plant burning Powder River Basin (PRB) coal, Otter Tail Power Company's Big Stone Plant, in Big Stone City, South Dakota. The $13.4 million project was installed in October 2002. Project related testing concluded in December 2005. The following Final Technical Report has been prepared for the project entitled ''Demonstration of a Full-Scale Retrofit of the Advanced Hybrid Particulate Collector Technology'' as described in DOE Award No. DE-FC26-02NT41420. The report presents the operation and performance results of the system.

Tom Hrdlicka; William Swanson

2005-12-01T23:59:59.000Z

315

A comparative analysis of configurations of linear Fresnel collectors for concentrating solar power  

Science Journals Connector (OSTI)

Abstract Linear Fresnel collector arrays present some relevant advantages in the domain of concentrating solar power because of their simplicity, robustness and low capital cost. However, they also present important drawbacks and limitations, notably their average concentration ratio, which seems to limit significantly the performance of these systems. First, the paper addresses the problem of characterizing the mirror field configuration assuming hourly data of a typical year, in reference to a configuration similar to that of Fresdemo. For a proper comparative study, it is necessary to define a comparison criterion. In that sense, a new variable is defined, the useful energy efficiency, which only accounts for the radiation that impinges on the receiver with intensities above a reference value. As a second step, a comparative study between central linear Fresnel reflectors and compact linear Fresnel reflectors is carried out. This analysis shows that compact linear Fresnel reflectors minimize blocking and shading losses compared to a central configuration. However this minimization is not enough to overcome other negative effects of the compact Fresnel collectors, as the greater dispersion of the rays reaching the receiver, caused by the fact that mirrors must be located farther from the receiver, which yields to lower efficiencies.

María J. Montes; Carlo Rubbia; Rubén Abbas; José M. Martínez-Val

2014-01-01T23:59:59.000Z

316

A water-trickle type solar collector with a massive concrete slab for heat storage and radiation /TMU solar system I/  

SciTech Connect

Experimental results are reported for a simple open type solar collector - a water trickle type collector - used in combination with a massive concrete slab for energy storage. This relatively low cost system was installed on a typical Japanese house in Yokohama City and measurements were made of the interior temperature. The system showed considerable promise for application in Japan.

Ito, N. (Tokyo Metropolitan University, Tokyo, Japan); Matsuda, K. (Kyushu Institute of Design, Kyushu, Japan); Ishii, A. (Ministry of Construction, Building Research Institute, Japan)

1980-01-01T23:59:59.000Z

317

Research at the Building Research Establishment into the Applications of Solar Collectors for Space and Water Heating in Buildings [and Discussion  

Science Journals Connector (OSTI)

...and the E.E.C. Solar space heating is...experimental low energy house laboratories...using conventional solar collectors with interseasonal heat storage and the other a heat pump with an air solar collector. Studies...means of conserving energy in buildings. The...

1980-01-01T23:59:59.000Z

318

Technical and economic evaluation of the utilization of solar energy at South Africa's SANAE IV base in Antarctica  

Science Journals Connector (OSTI)

The technical and economic feasibility of utilizing solar energy at South Africa's SANAE IV station in Antarctica was evaluated in order to estimate potential financial and external savings, and to alleviate the programme's dependence on the special blend of diesel shipped annually from Cape Town. The average global horizontal and tilted insolation rates at the base were studied, energy consumption data of the station was investigated, technical performance characteristics of devices for harnessing solar energy were assessed and an economic analysis was completed. It was shown that at SANAE IV flat-plate solar thermal collectors could potentially be used in conjunction with the snow smelter (a device that meets the station's fresh water demand) and that photovoltaic modules could feasibly be used to reduce the station's electrical demand. Flat-plate solar thermal collectors could collect solar energy at an average of 3.13 R/kWh (viz. 0.49 US$/kWh) from a suggested 143 m2 array, while comparatively a 40 kWp photovoltaic system would be less economically sound and only able to pay back costs at the end of the system's expected 25-year lifetime, generating electricity at an estimated 3.20 R/kWh (annual electrical consumption at SANAE IV amounts to more than 1062 MWh). The total diesel savings of the solar thermal and photovoltaic systems were estimated at approximately 12 245 and 9958 l, respectively, which represent savings in externalities of R67 338 and R55 879 each.

Jürgen R. Olivier; Thomas M. Harms; Daniël J. Esterhuyse

2008-01-01T23:59:59.000Z

319

Effects of environmental factors on the conversion efficiency of solar thermoelectric co-generators comprising parabola trough collectors and thermoelectric modules without evacuated tubular collector  

Science Journals Connector (OSTI)

Abstract Solar thermoelectric co-generators (STECGs) are an attractive means of supplying electric power and heat simultaneously and economically. Here we examine the effects of environmental factors on the conversion efficiencies of a new type of STECG comprising parabolic trough concentrators and thermoelectric modules (TEMs). Each TEM array was bonded with a solar selective absorber plate and directly positioned on the focal axis of the parabolic concentrator. Glass tubular collectors were not used to encase the TEMs. Although this makes the overall system simpler, the environmental effects become significant. Simulations show that the performance of such a system strongly depends on ambient conditions such as solar insolation, atmospheric temperature and wind velocity. As each of these factors increases, the thermal losses of the STECG system also increase, resulting in reduced solar conversion efficiency, despite the increased radiation absorption. However, the impact of these factors is relatively complicated. Although the electrical efficiency of the system increases with increasing solar insolation, it decreases with increasing ambient temperature and wind velocity. These results serve as a useful guide to the selection and installation of STECGs, particularly in Guangzhou or similar climate region.

Chao Li; Ming Zhang; Lei Miao; Jianhua Zhou; Yi Pu Kang; C.A.J. Fisher; Kaoru Ohno; Yang Shen; Hong Lin

2014-01-01T23:59:59.000Z

320

Stabilizing Effect of Finite-Gyroradius Beam Particles on the Tilting Mode of Spheromaks  

Science Journals Connector (OSTI)

The equilibrium shape of a low-pressure spheromak plasma with a small component of toroidal current carried by finite-gyroradius particles is computed. The stabilizing influence of this current on the tilting mode is determined by employing an energy principle that includes gyroscopic and finite-gyroradius effects.

R. N. Sudan and P. K. Kaw

1981-08-24T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Roughness of a tilted anharmonic string at depinning T. Goodman1  

E-Print Network (OSTI)

a string with a net average tilt, we demonstrate that the anhar- monic elastic energy crosses the model renormalization group calculation by Le Doussal and Wiese [8] argued that the quenched KPZ term can indeed with zero average and unit vari- ance, f is a uniform external driving force, and Eel is the elastic energy

Teitel, Stephen L.

322

Identification of Avalanche Precursors by Acoustic Probing in the Bulk of Tilted Granular Layers  

E-Print Network (OSTI)

Identification of Avalanche Precursors by Acoustic Probing in the Bulk of Tilted Granular Layers M simultaneously caracterize precursors on the free surface with an optical method and in the bulk with acoustic to probe rearrangements in the bulk of the granular material. A linear method can also be used provided

Paris-Sud XI, Université de

323

Friction in (im-)miscible polymer brush systems and the role of transverse polymer-tilting  

E-Print Network (OSTI)

Friction in (im-)miscible polymer brush systems and the role of transverse polymer-tilting Sissi de preferred solvent, leading to low friction and low wear rates. Here, we demonstrate, using molecular systems also show smaller friction than miscible systems, although the friction reduction is less than

Mueser, Martin

324

Application of the Cubed-Sphere Grid to Tilted Black-Hole Accretion Disks  

SciTech Connect

In recent work we presented the first results of global general relativistic magnetohydrodynamic (GRMHD) simulations of tilted (or misaligned) accretion disks around rotating black holes. The simulated tilted disks showed dramatic differences from comparable untilted disks, such as asymmetrical accretion onto the hole through opposing 'plunging streams' and global precession of the disk powered by a torque provided by the black hole. However, those simulations used a traditional spherical-polar grid that was purposefully underresolved along the pole, which prevented us from assessing the behavior of any jets that may have been associated with the tilted disks. To address this shortcoming we have added a block-structured 'cubed-sphere' grid option to the Cosmos++ GRMHD code, which will allow us to simultaneously resolve the disk and polar regions. Here we present our implementation of this grid and the results of a small suite of validation tests intended to demonstrate that the new grid performs as expected. The most important test in this work is a comparison of identical tilted disks, one evolved using our spherical-polar grid and the other with the cubed-sphere grid. We also demonstrate an interesting dependence of the early-time evolution of our disks on their orientation with respect to the grid alignment. This dependence arises from the differing treatment of current sheets within the disks, especially whether they are aligned with symmetry planes of the grid or not.

Fragile, P C; Lindner, C C; Anninos, P; Salmonson, J D

2008-09-24T23:59:59.000Z

325

Evaluation of solar energy resources by establishing empirical models for diffuse solar radiation on tilted surface and analysis for optimum tilt angle for a prospective location in southern region of Sindh, Pakistan  

Science Journals Connector (OSTI)

Abstract Diffuse solar radiation data is very important and is required for solar energy system implementations. The main purpose of the present study is to evaluate solar energy resources by establishing diffuse solar radiation models and obtaining optimum tilt angle fora prospective location is southern region of Sindh, Pakistan. Due to the unavailability of measured diffuse solar radiation data, nine new models, based on available data from local agency and values obtain from existing models, to predict diffuse solar radiation on tilted surface has been established. The best model was chosen based on test results from statistical indicators. The optimum tilt angle for monthly, seasonally, half-yearly and yearly adjustment was determined. The optimum tilt angle varies from 0° in May, June and July to 49° in December. The yearly optimum tilt angle was found as 23°, which is close to latitude of investigated location (25°07?N). The monthly average total, beam and diffuse solar radiations were calculated for optimum and vertical tilted surfaces and were compared with those obtain for horizontal surfaces. The half-yearly adjustment of optimum tilt angle is recommended for the investigated location because very small difference in annual solar energy gains in comparison with monthly or seasonal adjustment. The total annual energy for completer year and for four seasons of the year was calculated and found that maximum total annual energy is obtained at optimum tilt angle.

Shahnawaz Farhan Khahro; Kavita Tabbassum; Shahnawaz Talpur; Mohammad Bux Alvi; Xiaozhong Liao; Lei Dong

2015-01-01T23:59:59.000Z

326

Heat transfer to non-Newtonian power-law fluid past a continuously moving porous flat plate with heat flux  

Science Journals Connector (OSTI)

The analysis of heat transfer to the non-Newtonian power-law fluid flow past a continuously moving flat porous plate in presence of suction/injection with heat flux has been presented. We have obtained...n...=1 a...

B. P. Jadhav; B. B. Waghmode

1990-01-01T23:59:59.000Z

327

Convective currents in nucleate pool boiling and their effects on the heat flux from varying diameter flat plate heating elements  

E-Print Network (OSTI)

investigation was conducred to amine the effects of convection currents in nucleate oool boil ing and to determine the changes in critical heat flux caused by varying the diameter of horizontal flat olate heating surfaces. Freon 113 (Trichlorotrifluoroethane... by high energy costs and thc need to economize in industrial heat transfer applications . I'nucleate boiling is a very efficient neans of heat transfer because of the large sur ace areas involved in vaporization of the bulk fluid. as bubbles form...

Morford, Peter Stephen

1980-01-01T23:59:59.000Z

328

Effects of axial plate heat conduction on the thermal performance of a laminar counterflow flat plate heat exchanger  

E-Print Network (OSTI)

UC (I ~ M) ?0 e DO VC {I, N) ?O. DO UH(I, l)=0 DO VH (I, 1) ?O. DO ALONG FLUID CENTERLINE DO 6 I?1, N FOR VOBTICITY AMD STREAM WH(I, M) =0 ODO WC (I ~ 'l) =Do ODD PSIC(I ~ 1) =le ODO-RD PSIH fI, N) 1. ODO-BD CENTERLINE VALOIS FOB TH...-VELOCITY HOT' CALL POUT (VH r NrN) WRITE (6, 80) PRINT ~ HOT ILUID TEHPZRATURE ~ CALL POUT, {TH ~ N, N) llRITE (6 ~ 80) IF (IPLAG ZO. 1) GO TO 37 37 43 712 PRINTi o SOLID TEMPERATURE ~ CALL POUT (TS, H, 1) GO TO 42 WRITE (6 ~ 43) FORMAT(/, 20X, i...

Demko, Jonathan Alexander

2012-06-07T23:59:59.000Z

329

S O L A R A I R COLLECTORS: How Much Can You S  

NLE Websites -- All DOE Office Websites (Extended Search)

. . . . . . - . . . . . . . - . . . - . . . . . . . - . . . . . . . - . . - - . . . . . . . . . . . ..- a- c I S O L A R A I R COLLECTORS: How Much Can You S a v e ? A p r i l , 1985 DOE/CS/69097--T2 DE85 015762 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsi- bility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Refer- ence herein to any specific commercial product, process, or service by trade name, trademark,

330

On the feasibility of colored glazed thermal solar collectors based on thin film interference filters  

Science Journals Connector (OSTI)

Glazed thermal solar collectors, typically equipped with black, optical selective absorber sheets, exhibit good energy conversion efficiency. However, the black color, and sometimes the visibility of tubes and corrugations of the metal sheets, limit the architectural integration into buildings. In order to overcome this drawback, interference filters are considered as a promising approach. Multilayered thin film stacks deposited on the cover glass can produce a colored reflection hiding the black absorber without a great loss of energy. These interference filters are designed and optimized by numerical simulation. Such coatings are deposited by vacuum processes (e.g. magnetron sputtering) and also via the SolGel method. Optical measurements, such as real-time laser-reflectometry and spectrophotometry, are suitable to determine film thicknesses and optical constants of individual layers, and to measure color coordinates and solar transmittance for the multilayer stacks. Advantages and disadvantages of the different coating processes are discussed.

A. Schüler; C. Roecker; J.-L. Scartezzini; J. Boudaden; I.R. Videnovic; R.S.-C. Ho; P. Oelhafen

2004-01-01T23:59:59.000Z

331

Use of charge-selective membranes for electrodialytic desalination of mineralized drainage collector waters  

SciTech Connect

The purpose of this work was to examine the possibility of desalination, without preliminary softening, of drainage collector waters of a medium degree mineralization, represented by a simulated solution of the same cation composition, with the use of single-charge-selective membranes. A cation-exchange membrane obtained by modification of the commercial MK-100 membrane with ethylenediamine (6), was used for this purpose. The modification was effected by treatment of the chlorosulfonated matrix with aqueous ethylenediamine solution at room temperature. The matrix, aminated on one side was then treated with concentrated NaOH solution to convert unreacted sulfonyl chloride groups into sulfo. The capacity of the modified MK-100M membrane for sulfo groups was 1.8 meq/g. The possibility of obtaining highly concentrated brines was examined at the same time.

Grebenyuk, V.D.; Veisov, B.K.; Chebotareva, R.D.; Braude, K.P.; Nefedova, G.Z.

1986-10-10T23:59:59.000Z

332

Cleaning strategies for parabolic-trough solar-collector fields; guidelines for decisions  

SciTech Connect

This report is intended to assist the owner or operator of a parabolic trough solar collector system to decide on a cleaning strategy (equipment, materials, procedures, and schedules). The guidelines are based on information obtained in past research studies, as well as interviews with vendors and users of cleaning and water treatment equipment. The basic procedure recommended utilizes high pressure portable washing equipment. However, since the cleaning problem is so site-specific, no single, detailed approach can be specified. A systematic procedure for evaluating the particular requirements of a site is therefore given. This will allow the solar energy system operator to develop a cleaning strategy which is cost-effective because it is suited to local conditions.

Bergeron, K.D.; Freese, J.M.

1981-06-01T23:59:59.000Z

333

Low-cost evacuated-tube solar collector appendices. Final report  

SciTech Connect

A low cost solar heat energy collector module and array has been designed using the evacuated tube, selective absorber, air cooled concept. Glass tubing as used in fluorescent lamps with automatic sealing methods is a key feature of the evacuated tube design. A molded fiber glass concentrating reflector panel and sheet metal header assembly are proposed. Major design problems involved included the cost of materials and labor, thermal expansion and distortion problems, high stagnation and operating temperatures, isolation, thermal efficiency, sealing, joining, air pressure drop, and weight of the preassembled module. A cost of less than $5 per active square foot of collecting surface has been estimated for materials and labor of the module and its mounting frame.

Beecher, D.T.

1980-05-31T23:59:59.000Z

334

Numerical study of heat loss from a non-evacuated receiver of a solar collector  

Science Journals Connector (OSTI)

Abstract Heat loss from receivers of solar collectors is a major reason for drop in their efficiency. Receiver pipes enclosed in glass tubes with evacuated annulus show considerable reduction in heat losses. However, manufacturing and maintenance costs for such receivers are high. An inexpensive alternative is a similar receiver with non-evacuated annulus. This paper presents a numerical study of heat loss from a non-evacuated receiver typically used in parabolic trough collectors, generating moderate temperatures and designed particularly for process heat applications. In order to come closer to the realistic situation, rather than assuming uniform temperature distribution on it, receiver pipe temperature has been assumed to be varying along the surface. Sinusoidal and square wave functions are employed in modeling, since actual temperature distributions on solar receiver pipes are combinations of these two functions. Main goal of the paper is to optimize the design of the non-evacuated solar receiver for minimum heat loss, by using CFD technique. Also effects on heat loss from receivers due to different parameters like average temperature (Ta) of the pipe, non-uniformity in the temperature (?) along its surface, hour angle (?), denoting position of the sun in the sky and radius ratio (RR) of radius of receiver pipe to that of outer glass tube have been studied. It is seen that as non-uniformity in temperature distribution increases in both types of temperature distribution, heat losses from receiver pipes decrease up to 10%. Also as hour angle increases from 0° to 90°, heat loss decreases by 20% in case of sinusoidal temperature distribution and 24% in case of square wave temperature distribution. The effect of radius ratio (RR) on heat loss has been studied. In present study, we found out that 1.375 is critical radius ratio for which heat losses from receiver are minimum

Ramchandra G. Patil; Dhanaji M. Kale; Sudhir V. Panse; Jyeshtharaj B. Joshi

2014-01-01T23:59:59.000Z

335

Energy modeling of photovoltaic thermal systems with corrugated unglazed transpired solar collectors – Part 2: Performance analysis  

Science Journals Connector (OSTI)

Abstract This paper is the second of two companion papers focused on energy modeling and performance analysis of building-integrated photovoltaic thermal (PV/T) systems with corrugated unglazed transpired solar collectors (UTCs). In Part 1, energy models are presented for two configurations: UTC only and UTC with PV panels. The models predict the energy output of the system for different weather and system design conditions and are validated using measured data from an outdoor test facility. In this paper (Part 2), the system performance is evaluated based on data drawn from the literature and simulations with Computational Fluid Dynamics (CFD) and energy models. The analysis includes parameters that are unique for this system, such as the corrugation geometry and the collector orientation. Validated, high resolution CFD simulations are used to study the impact of plate orientation and incident turbulence intensity, based on the comparison of exterior and interior Nusselt (Nu) number and the cavity exit air temperature, as well as the PV surface temperature when \\{UTCs\\} are integrated with PV panels. It is found that for configurations with UTC only, both exterior and interior convective heat transfer is enhanced in the ‘vertical’ installation, while similar results were obtained for increased incident turbulence intensity levels. However, only minor influences from these two parameters are observed for \\{UTCs\\} with PV panels. The energy model is used to investigate the optimal geometry for both configurations. It is found that parameters such as slope length and corrugation wavelength have the most significant impact on UTC performance while the wavelength and PV panel height have the largest effect for \\{UTCs\\} with PV panels.

Siwei Li; Panagiota Karava

2014-01-01T23:59:59.000Z

336

Role of self-propulsion of marine larvae on their probability of contact with a protruding collector located in a sea current  

E-Print Network (OSTI)

Settlement of marine larvae on a substrate is a fundamental problem of marine life. The probability of settlement is one of the quantitative characteristic of the settlement process. The probability of larval contact with a substrate is the upper bound of the probability of settlement. This work addresses the problem of contact probability and contact rate of marine invertebrate larvae with an isolated protruding collector located in an unbounded sea current. There are two common approaches to the problem of contact probability. In one, a collector induces certain cues, which help a larvae find the collector. In such a case, the larva moves towards the collector deliberately, using its navigation and propulsion devices. In the second approach, a larva moves towards a collector as a passive small particle. In this case, the cause of contact of a larva with a collector is a mechanical collision of a small moving body with a large obstacle. We considered a larva which does not know the location of the collector,...

Zilman, Gregory; Liberzon, Alex; Perkol-Finkel, Shimrit; Benayahu, Yehuda

2011-01-01T23:59:59.000Z

337

Molecular Simulation of Fracture Dynamics of Symmetric Tilt Grain Boundaries in Graphene  

E-Print Network (OSTI)

Atomistic simulations were utilized to obtain microscopic information of the elongation process in graphene sheets consisting of various embedded symmetric tilt grain boundaries (GBs). In contrast to pristine graphene, these GBs fractured in an extraordinary pattern under transverse uniaxial elongation in all but the largest misorientation angle case, which exhibited intermittent crack propagation and formed many stringy residual connections after quasi mechanical failure. The strings known as monoatomic carbon chains (MACCs), whose importance was recently highlighted, gradually extended to a maximum of a few nanometers as the elongation proceeded. These features, which critically affect the tensile stress and the shape of stress-strain curve, were observed in both armchair and zigzag-oriented symmetric tilt GBs. However, there exist remarkable differences in the population density and the achievable length of MACCs appearing after quasi mechanical failure which were higher in the zigzag-oriented GBs. In addi...

Jhon, Young In; Smith, Robert; Jhon, Myung S

2012-01-01T23:59:59.000Z

338

Inversion of azimuthally dependent NMO velocity in transversely isotropic media with a tilted axis of symmetry  

SciTech Connect

Just as the transversely isotropic model with a vertical symmetry axis (VTI media) is typical for describing horizontally layered sediments, transverse isotropy with a tilted symmetry axis (TTI) describes dipping TI layers (such as tilted shale beds near salt domes) or crack systems. P-wave kinematic signatures in TTI media are controlled by the velocity V{sub PO} in the symmetry direction, Thomsen's anisotropic coefficients {xi} and {delta}, and the orientation (tilt {nu} and azimuth {beta}) of the symmetry axis. Here, the authors show that all five parameters can be obtained from azimuthally varying P-wave NMO velocities measured for two reflectors with different dips and/or azimuths (one of the reflectors can be horizontal). The shear-wave velocity V{sub SO} in the symmetry direction, which has negligible influence on P-wave kinematic signatures, can be found only from the moveout of shear waves. Using the exact NMO equation, the authors examine the propagation of errors in observed moveout velocities into estimated values of the anisotropic parameters and establish the necessary conditions for a stable inversion procedure. Since the azimuthal variation of the NMO velocity is elliptical, each reflection event provides them with up to three constraints on the model parameters. Generally, the five parameters responsible for P-wave velocity can be obtained from two P-wave ellipses, but the feasibility of the moveout inversion strongly depends on the tilt {nu}. While most of the analysis is carried out for a single layer, the authors also extend the inversion algorithm to vertically heterogeneous TTI media above a dipping reflector using the generalized Dix equation. A synthetic example for a strongly anisotropic, stratified TTI medium demonstrates a high accuracy of the inversion.

Grechka, V.; Tsvankin, I.

2000-02-01T23:59:59.000Z

339

Existence of the Wigner function with correct marginal distributions along tilted lines on a lattice  

E-Print Network (OSTI)

In order to determine the Wigner function uniquely, we introduce a new condition which ensures that the Wigner function has correct marginal distributions along tilted lines. For a system in $N$ dimensional Hilbert space, whose "phase space" is a lattice with $N^2$ sites, we get different results depending on whether $N$ is odd or even. Under the new condition, the Wigner function is determined if $N$ is an odd number, but it does not exist if $N$ is even.

Minoru Horibe; Akiyoshi Takami; Takaaki Hashimoto; Akihisa Hayashi

2001-08-10T23:59:59.000Z

340

South America Latitude Tilted SR Solar Model from INPE and LABSOLAR |  

Open Energy Info (EERE)

Latitude Tilted SR Solar Model from INPE and LABSOLAR Latitude Tilted SR Solar Model from INPE and LABSOLAR Dataset Summary Description (Abstract): Mean values of Latitude Tilted Solar Radiation in kWh/m2/day for 40km cells for 1 year (month, season, year) based on data from 1995 to 2005 (Purpose): To provide a set of consistent, reliable, verifiable, and accessible global data sets for international and in-country investors and other stakeholders (Supplemental Information): The BRASIL-SR model (developed by INPE - National Institute for Space Research) and the ARCVIEW software were used to produce the dataset and SHAPE files.The assessment of reliability levels of the BRASIL-SR model were performed through the evaluation of the deviations shown by the estimated values for solar radiation flux vis-à-vis the values measured at the surface (ground truth). This evaluation was done in two phases. The first phase consisted in an inter-comparison between the core radiation transfer models adopted by the SWERA Project to map the solar energy in the various countries participating in the project. The HELIOSAT model took part in this phase like benchmark due to its employment to map solar energy resources in countries from European Union. In the second phase, the solar flux estimates provided by the BRASIL-SR model were compared with measured values acquired at several solarimetric stations spread along the Brazilian territory. The BRASIL-SR model is not validated for areas covered by snow.

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

NREL: Learning - Solar Hot Water  

NLE Websites -- All DOE Office Websites (Extended Search)

Hot Water Hot Water Photo of solar collectors on a roof for a solar hot water system. For solar hot water systems, flat-plate solar collectors are typically installed facing south on a rooftop. The shallow water of a lake is usually warmer than the deep water. That's because the sunlight can heat the lake bottom in the shallow areas, which in turn, heats the water. It's nature's way of solar water heating. The sun can be used in basically the same way to heat water used in buildings and swimming pools. Most solar water heating systems for buildings have two main parts: a solar collector and a storage tank. The most common collector is called a flat-plate collector. Mounted on the roof, it consists of a thin, flat, rectangular box with a transparent cover that faces the sun. Small tubes

342

Feasibility Study on the Use of a Solar Thermoelectric Cogenerator Comprising a Thermoelectric Module and Evacuated Tubular Collector with Parabolic Trough Concentrator  

Science Journals Connector (OSTI)

We have designed a new solar thermoelectric cogeneration system consisting of an evacuated tubular solar collector (ETSC) with a parabolic trough concentrator (PTC) and thermoelectric modules (TEMs) to supply ...

L. Miao; M. Zhang; S. Tanemura; T. Tanaka; Y. P. Kang…

2012-06-01T23:59:59.000Z

343

Design and construction of a novel quad tilt-wing UAV E. Cetinsoy, S. Dikyar, C. Hancer, K.T. Oner, E. Sirimoglu, M. Unel  

E-Print Network (OSTI)

Design and construction of a novel quad tilt-wing UAV E. Cetinsoy, S. Dikyar, C. Hancer, K.T. Oner 12 March 2012 Available online xxxx Keywords: UAV Quad tilt-wing Aerodynamic design Carbon composite VehIcle). SUAVI is an electric powered quad tilt-wing UAV that is capable of vertical takeoff

Ã?Â?nel, Mustafa

344

Interactions and Implications of a Collector Well with a River in an Unconfined Aquifer with Regional Background Flow  

E-Print Network (OSTI)

; Steward, 1999; Zhan, 1999; Zhan and Cao, 2000]. These wells are often placed near or under rivers, where they collect water from both the surface and aquifer that is naturally filtered through low permeability riverbank sediments. Seines et al. [1994... various conditions [Schafer, 1996; Zhan, 1999; Steward, 1999; Zhan and Cao, 2000; Stewart and Jin, 2001]. Radial collector wells are complex fluid collection systems that induce intricate flow dynamics as a result of their pumping because...

Dugat, William D., IV

2010-01-14T23:59:59.000Z

345

A survey on control schemes for distributed solar collector fields. Part I: Modeling and basic control approaches  

Science Journals Connector (OSTI)

This article presents a survey of the different automatic control techniques that have been applied to control the outlet temperature of solar plants with distributed collectors during the last 25 years. Different aspects of the control problem involved in this kind of plants are treated, from modeling and simulation approaches to the different basic control schemes developed and successfully applied in real solar plants. A classification of the modeling and control approaches is used to explain the main features of each strategy.

E.F. Camacho; F.R. Rubio; M. Berenguel; L. Valenzuela

2007-01-01T23:59:59.000Z

346

Investigation of failed fuel detection and location using a flux tilting method in a fast breeder reactor  

SciTech Connect

Detection and location of failed fuel in a liquid-metal fast breeder reactor (LMFBR) are very important both for safety and availability. When a fuel failure is detected, it is desirable to identify the failed subassembly quickly to reduce plant shutdown time. The flux tilting method is expected to effectively identify the defective subassembly. The feasibility of the flux tilting method is investigated for an LMFBR with a 100-MW (electric) homogeneous core. A numerical simulation is performed to estimate the viability of the flux tilting method, and a combination of the flux tilting method and the sipping method is found to be very effective in identifying the failed subassembly. In this paper a functional scheme for a computer-aided failed fuel detection and location system is discussed as part of a future on-line support system.

Hamada, M.; Uehara, K.; Muramatsu, K. (Japan Atomic Power Co., 1-6-1 Otemachi, Chiyoda-ku, Tokyo 100 (JP)); Kamei, T.; Tamaoki, T.; Yamaoka, M.; Sonada, Y.; Sano, Y. (Toshiba Corp., Nuclear Engineering Lab., 4-1 Ukishima-cho, Kawasaki-ku, Kawasaki 210 (JP))

1992-04-01T23:59:59.000Z

347

Measured and Predicted Rotor-Pad Transfer Functions for a Rocker-Pivot Tilting-Pad Journal Bearing  

E-Print Network (OSTI)

Many researchers have compared predicted stiffness and damping coefficients for tilting-pad journal bearings (TPJBs) to measurements. Most have found that direct damping is consistently overpredicted. The thrust of this research is to explain...

Wilkes, Jason Christopher

2012-02-14T23:59:59.000Z

348

Real-time vibration measurement by a spatial phase-shifting technique with a tilted holographic interferogram  

Science Journals Connector (OSTI)

Real-time vibration measurement by a tilted holographic interferogram is presented that utilizes the real-time digital fringe processor of a video signal. Three intensity data sampled...

Nakadate, Suezou; Isshiki, Masaki

1997-01-01T23:59:59.000Z

349

A study of PV/T collector with honeycomb heat exchanger  

Science Journals Connector (OSTI)

This paper present a study of a single pass photovoltaic/thermal (PV/T) solar collector combined with honeycomb heat exchanger. A PV/T system is a combination of photovoltaic panel and solar thermal components in one integrated system. In order to enhance the performance of the system a honeycomb heat exchanger is installed horizontally into the channel located under the PV module. Air is used as the heat remover medium. The system is tested with and without the honeycomb at irradiance of 828 W/m2 and mass flow rate spanning from 0.02 kg/s to 0.13 kg/s. It is observed that the aluminum honeycomb is capable of enhancing the thermal efficiency of the system efficiently. At mass flow rate of 0.11 kg/s the thermal efficiency of the system without honeycomb is 27% and with honeycomb is 87 %. Throughout the range of the mass flow rate the electrical efficiency of the PV module improved by 0.1 %. The improved design is suitable to be further investigated as solar drying system and space heating.

F. Hussain; M. Y. H. Othman; B. Yatim; H. Ruslan; K. Sopian; Z. Ibarahim

2013-01-01T23:59:59.000Z

350

Reliability evaluation for electrical collector systems of wind farm using the section enumeration technique  

Science Journals Connector (OSTI)

Topology has a significant effect on the reliability performance of an electrical collector system (ECS) of wind farms. Novel indices for the reliability of wind farm ECS are presented based on topological features of wind farm ECS in this paper. The concept of the section for a wind farm ECS is defined. The probability table of multistate capacity (PTMC) for a wind turbine generator (WTG) and the Probability Table of the Number of WTG in Up-state (PTNU) for a section can be created. Based on the PTMC and PTNU PTMC of a wind farm can be established using the state enumeration algorithm and the matrix operations. Therefore the reliability evaluation model considering effects of wind speed and component failures can be built. The proposed model not only considers the multi-failures of ECS components including failures of cable feeder WTG and wind turbine transformer (WTT) but also states of switching devices in failure disconnection and switching processes. Four wind farm ECS topologies i.e. radial topology single-sided ring topology double-sided ring topology and star topology are implemented. Case studies on the reliability evaluation of wind farm ECS are used to verify the feasibility and validity of the proposed technique.

Kaigui Xie; Hejun Yang; Bo Hu; David Yu

2013-01-01T23:59:59.000Z

351

Separation Of Uranium And Plutonium Isotopes For Measurement By Multi Collector Inductively Coupled Plasma Mass Spectroscopy  

SciTech Connect

Uranium (U) and plutonium (Pu) isotopes in coral soils, contaminated by nuclear weapons testing in the northern Marshall Islands, were isolated by ion-exchange chromatography and analyzed by mass spectrometry. The soil samples were spiked with {sup 233}U and {sup 242}Pu tracers, dissolved in minerals acids, and U and Pu isotopes isolated and purified on commercially available ion-exchange columns. The ion-exchange technique employed a TEVA{reg_sign} column coupled to a UTEVA{reg_sign} column. U and Pu isotope fractions were then further isolated using separate elution schemes, and the purified fractions containing U and Pu isotopes analyzed sequentially using multi-collector inductively coupled plasma mass spectrometer (MCICP-MS). High precision measurements of {sup 234}U/{sup 235}U, {sup 238}U/{sup 235}U, {sup 236}U/{sup 235}U, and {sup 240}Pu/{sup 239}Pu in soil samples were attained using the described methodology and instrumentation, and provide a basis for conducting more detailed assessments of the behavior and transfer of uranium and plutonium in the environment.

Martinelli, R E; Hamilton, T F; Williams, R W; Kehl, S R

2009-03-29T23:59:59.000Z

352

Entanglement, avoided crossings, and quantum chaos in an Ising model with a tilted magnetic field  

SciTech Connect

We study a one-dimensional Ising model with a magnetic field and show that tilting the field induces a transition to quantum chaos. We explore the stationary states of this Hamiltonian to show the intimate connection between entanglement and avoided crossings. In general, entanglement gets exchanged between the states undergoing an avoided crossing with an overall enhancement of multipartite entanglement at the closest point of approach, simultaneously accompanied by diminishing two-body entanglement as measured by concurrence. We find that both for stationary as well as nonstationary states, nonintegrability leads to a destruction of two-body correlations and distributes entanglement more globally.

Karthik, J.; Sharma, Auditya; Lakshminarayan, Arul [Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India)

2007-02-15T23:59:59.000Z

353

FLASH seminar -14/01/08 Eduard Prat, DESY Beam tilt studies at FLASH  

E-Print Network (OSTI)

generated different vertical bumps at BPM9ACC1. For each bump we measured: -Dispersion from ACC1 -Beam tilt.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 V1GUN (23-10-07) #BPM Orbitresponse[mm/mrad] 1mrad model 0 2 4 6 8 10 12 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 V3GUN (23-10-07) #BPM Orbitresponse[mm/mrad] 1mrad model 0 2 4 6

354

An experimental investigation of a tilt rotor aircraft wake in ground effect  

E-Print Network (OSTI)

: Sktlld dS t' 1, "~Et 18, 6 (1975), pp. 51-673. Hunt, J. C. R. , Poulton, E. C. , and Mumford, J. C. , "The Effects of Wldppl:Sd't*l Bd tldt lt*p*' t, "~Bi1di Environment, 11 (1976), pp. 15-28. 50 VITA gichael Louis Frey III was born January 4, 1957...EXPERIMENTAL INVESTIGATION OF A TILT ROTOR AIRCRAFT WAKE IN GROUND EFFECT A Thesis by MICHAEL LOUIS FREY III Submi. tted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER...

Frey, Michael Louis

1982-01-01T23:59:59.000Z

355

Solar heat gain coefficient of complex fenestrations with a venetian blind for differing slat tilt angles  

SciTech Connect

Measured bidirectional transmittances and reflectances of a buff-colored venetian blind together with a layer calculation scheme developed in previous publications are utilized to produce directional-hemispherical properties for the venetian blind layer and solar heat gain coefficients for the blind in combination with clear double glazing. Results are presented for three blind slat tilt angles and for the blind mounted either interior to the double glazing or between the glass panes. Implications of the results for solar heat gain calculations are discussed in the context of sun positions for St. Louis, MO.

Klems, J.H.; Warner, J.L.

1996-08-01T23:59:59.000Z

356

Heliostat tilt and azimuth angle charts and the heliostat orientation protractor  

SciTech Connect

This paper reports that using cartesian heliostat field coordinates analytical expressions were derived for the heliostat tilt angle s, and heliostat azimuth angle {gamma} (clockwise from south). These expressions are dependent on the field cartesian coordinates of the center of the heliostat and the solar zenith and azimuth angles (clockwise from south), {theta}{sub z} and {Psi}, respectively. Here, cylindrical coordinates are conveniently used to derive the expressions for the heliostat angles s and {gamma}. The expression of {gamma}is used to construct the so-called heliostat orientation protractor. The protractor is a useful tool to determine the instantaneous heliostat azimuth angle as will be illustrated.

Elsayed, M.M.; Al-Rabghi, O.M. (Thermal Energy Dept., King Abdulaziz Univ., Jeddah 21413 (SA))

1992-02-01T23:59:59.000Z

357

Solar: monthly and annual average direct normal (DNI), global horizontal  

Open Energy Info (EERE)

South America from NREL South America from NREL Dataset Summary Description (Abstract): Monthly Average Solar Resource for horizontal and tilted flat-plates, and 2-axis tracking concentrating collectors. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to solar collectors. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The data were developed from NREL's Climatological Solar Radiation (CSR) Model. This model uses information on cloud cover, atmospheric water vapor and trace gases, and the amount of aerosols in the atmosphere to calculate the monthly average daily total insolation (sun and sky) falling on a horizontal surface. Existing ground measurement stations are used to validate the data where possible. The modeled values are accurate to approximately 10% of a true measured value within the grid cell due to the uncertainties associated with meteorological input to the model. The local cloud cover can vary significantly even within a single grid cell as a result of terrain effects and other microclimate influences. Furthermore, the uncertainty of the modeled estimates increase with distance from reliable measurement sources and with the complexity of the terrain.

358

Solar: monthly and annual average direct normal (DNI), global horizontal  

Open Energy Info (EERE)

Central America and the Carribean from NREL Central America and the Carribean from NREL Dataset Summary Description (Abstract): Monthly Average Solar Resource for horizontal and tilted flat-plates, and 2-axis tracking concentrating collectors. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to solar collectors. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The data were developed from NREL's Climatological Solar Radiation (CSR) Model. This model uses information on cloud cover, atmospheric water vapor and trace gases, and the amount of aerosols in the atmosphere to calculate the monthly average daily total insolation (sun and sky) falling on a horizontal surface. Existing ground measurement stations are used to validate the data where possible. The modeled values are accurate to approximately 10% of a true measured value within the grid cell due to the uncertainties associated with meteorological input to the model. The local cloud cover can vary significantly even within a single grid cell as a result of terrain effects and other microclimate influences. Furthermore, the uncertainty of the modeled estimates increase with distance from reliable measurement sources and with the complexity of the terrain.

359

Solar: monthly and annual average latitude tilt irradiance GIS data at  

Open Energy Info (EERE)

irradiance GIS data at irradiance GIS data at one-degree resolution of the World from NASA/SSE Dataset Summary Description (Abstract): Latitude Tilt Irradiance NASA Surface meteorology and Solar Energy (SSE) Release 6.0 Data Set (Jan 2008)22-year Monthly & Annual Average (July 1983 - June 2005) Parameter: Latitude Tilt Radiation (kWh/m^2/day) Internet: http://eosweb.larc.nasa.gov/sse/ Note 1: SSE Methodology & Accuracy sections online Note 2: Lat/Lon values indicate the lower left corner of a 1x1 degree region. Negative values are south and west; positive values are north and east. Boundaries of the -90/-180 region are -90 to -89 (south) and -180 to -179 (west). The last region, 89/180, is bounded by 89 to 90 (north) and 179 to 180 (east). The mid-point of the region is +0.5 added to the the Lat/Lon value. These data are regional averages; not point data.

360

Numerical study of tilt stability of prolate field-reversed configurations  

SciTech Connect

Global stability of the Field-Reversed Configuration (FRC) has been investigated numerically using both 3D MHD and hybrid (fluid electron and delta f particle ion) simulations. The stabilizing effects of velocity shear and large ion orbits on the n = 1 internal tilt mode in the prolate FRCs have been studied. Sheared rotation is found to reduce the growth rate, however a large rotation rate with Mach number of M greater than or approximately equal to 1 is required in order for significant reduction in the instability growth rate to occur. Kinetic effects associated with large thermal ion orbits have been studied for different kinetic equilibria. These simulations show that there is a reduction in the tilt mode growth rate due to finite ion Larmor radius (FLR) effects, but complete linear stability has not been found, even when the thermal ion gyroradius is comparable to the distance between the field null and the separatrix. The instability existing beyond the FLR theory threshold could be due to the resonant interaction of the wave with ions whose Doppler shifted frequency matches the betatron frequency.

E. V. Belova; S. C. Jardin; H. Ji, M. Yamada; R. Kulsrud

2000-06-21T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


361

Optimal solar-PV tilt angle and azimuth: An Ontario (Canada) case-study  

Science Journals Connector (OSTI)

The purpose of this article is to determine the tilt angle and azimuth for a photovoltaic panel in Ontario (Canada) at which revenue is maximised. Measured and modelled solar radiation data, simulated photovoltaic panel performance, hourly electricity market data and details regarding pricing regimes from 2003 to 2008 are used to study two different locations. In all instances, the desired tilt angle is slightly less than latitude (depending upon the particular pricing regime, between 36° and 38° for Ottawa, which is at a latitude of 45°N, and between 32° and 35° for Toronto, which is at a latitude of 44°N), and the desired azimuth is close to due south (depending upon the particular pricing regime, between 4° west of due south and 6° east of due south for Ottawa, and between 1° west of due south and 2° east of due south for Toronto). In conclusion, the importance of solar electricity – particularly valuable because of when it is produced and where it can be produced – is highlighted, as are future priorities for research.

Ian H. Rowlands; Briana Paige Kemery; Ian Beausoleil-Morrison

2011-01-01T23:59:59.000Z

362

Book Reviews  

Science Journals Connector (OSTI)

...Transactions of the Conference on the Use of Solar Energy, the Scientific Basis. vol...Part 1, Section A, Flat-plate collectors. 145 pp. vol. II, Section B, High-temperature solar furnaces. Solar power. 265 pp. vol. III, Part II...

1958-12-12T23:59:59.000Z

363

PROPRIETARY MATERIAL. 2008 The McGraw-Hill Companies, Inc. Limited distribution permitted only to teachers and educators for course preparation. If you are a student using this Manual, you are using it without permission.  

E-Print Network (OSTI)

it without permission. 14-63 14-72 The absorber plate and the glass cover of a flat-plate solar collector horizontal rectangular enclosure. The characteristic length in this case is the distance between the two for this geometry and orientation can be determined from (Ra = 3.689u104 - same as that for horizontal case) 557.1 m

Bahrami, Majid

364

Life cycle analysis of a building-integrated solar thermal collector, based on embodied energy and embodied carbon methodologies  

Science Journals Connector (OSTI)

Abstract The present study is a life cycle analysis of a patented building-integrated solar thermal collector which was developed/experimentally tested at the University of Corsica, in France, with the concept “integration into gutters/no visual impact”. Three configurations (reference and two alternatives) are evaluated. The life-cycle impact assessment methodologies of embodied energy (EE)/embodied carbon (EC), two databases and multiple scenarios are adopted. The results reveal that the reference system can considerably improve its environmental performance by utilizing collectors connected in parallel. The Energy Payback Time of the reference system decreases to less than 2 years by parallel connection while it is around 0.5 years if recycling is also adopted. The EE of the systems is around 3 GJprim/m2 and it is reduced to around 0.4–0.5 GJprim/m2 by recycling. The EC of the configurations is approximately 0.16 t CO2.eq/m2 without recycling and around 0.02–0.03 t CO2.eq/m2 with recycling. CO2.eq emissions are strongly related with electricity mix. A reduction 28–96% in CO2.eq emissions of the systems is achieved by adopting configurations with “double collector surface/output”. Concerning indicator of sustainability, the system with parallel connection shows a value of 0.78. The findings of the present investigation could be utilized for the design of building-integrated solar thermal systems as well as for research purposes.

Chr. Lamnatou; G. Notton; D. Chemisana; C. Cristofari

2014-01-01T23:59:59.000Z

365

Brazil Latitude Tilted Solar Radiation Model (40km) from INPE and LABSOLAR  

Open Energy Info (EERE)

40km) from INPE and LABSOLAR 40km) from INPE and LABSOLAR Dataset Summary Description (Abstract): Latitude tilted solar radiation in kWh/m2/day for 1 year organized into cells with 40km x 40km (Purpose): To provide a set of consistent, reliable, verifiable, and accessible global data sets for international and in-country investors and other stakeholders (Supplemental Information): The BRASIL-SR model and the SPRING software (both developed by INPE - National Institute for Space Research) were used to produce the dataset and SHAPE files.The assessment of reliability levels of the BRASIL-SR model were performed through the evaluation of the deviations shown by the estimated values for solar radiation flux vis-à-vis the values measured at the surface (ground truth). This evaluation was done in two phases. The first phase

366

Tilt and shift mode stability in a spheromak with a flux core  

Science Journals Connector (OSTI)

The stability of spheromak equilibria with a flux core or reversal coil is studied by means of an ideal magnetohydrodynamic (MHD) code. Results depend critically upon whether the flux hole region (the current free area just inside the separatrix) is treated as a perfectly conducting plasma or as a vacuum. This indicates that the tilt and shift modes persist as resistive instabilities if they are stable in ideal MHD. Specifically for nonoptimally shaped equilibria the flux core must nearly touch the current channel if the flux hole is a vacuum whereas the core may be slightly outside the separatrix if the flux hole has conducting plasma. A larger margin exists for optimally shaped equilibria.

John M. Finn

1984-01-01T23:59:59.000Z

367

3D Thermal-structural Analysis of an Absorber Tube of a Parabolic Trough Collector and the Effect of Tube Deflection on Optical Efficiency  

Science Journals Connector (OSTI)

Abstract In this paper deformation rate of an absorber tube of a parabolic trough collector due to a 3D solar flux density distribution is studied theoretically. Three dimensional temperature distribution and tube thermal expansion due to non-uniform solar flux over the tube are determined numerically. The local concentration ratio for the parabolic trough collectors, which is a key boundary condition in the thermal analysis is computed by Monte Carlo Ray Tracing method for different conditions. The governing equations of thermo-elastic constitutive are solved in three dimensions for steady state thermal and static structural analysis with appropriate boundary condition using Finite Volume and Finite Element numerical codes. Thermal stresses and strain are determined for two types of collectors; first one is a constructed collector and second one is under construction at Shiraz (Iran) solar thermal power plant. Results of the local concentration ratio, flux density, temperature distribution and thermal expansions are determined for the designed conditions. Appropriate flow rate and convection coefficient for each season are found in order to decrease tube bending, prevent optical efficiency drop of collectors, keep high factor of safety, and reduce cyclic daily amplitude motion which lead to longer life time of absorber tube.

S.M. Akbarimoosavi; M. Yaghoubi

2014-01-01T23:59:59.000Z

368

Solar space and water heating system at Stanford University Central Food Services Building. Final report  

SciTech Connect

This active hydronic domestic hot water and space heating system was 840 ft/sup 2/ of single-glazed, liquid, flat plate collectors and 1550 gal heat storage tanks. The following are discussed: energy conservation, design philosophy, operation, acceptance testing, performance data, collector selection, bidding, costs, economics, problems, and recommendations. An operation and maintenance manual and as-built drawings are included in appendices. (MHR)

Not Available

1980-05-01T23:59:59.000Z

369

Rotordynamic coefficients for a load-between-pad, flexible-pivot tilting pad bearing at high loads  

E-Print Network (OSTI)

The dynamic and static performance of a flexure-pivot tilting pad bearing is presented at a load between pad configuration for various load and speed combinations. A similar work performed on the same bearing at lower loads ranging from 0-1 MPa (0...

Hensley, John Eric

2006-10-30T23:59:59.000Z

370

Atomic structure of the {sigma}5 (210)/[001] symmetric tilt grain boundary in yttrium aluminum garnet  

SciTech Connect

The {Sigma}5(210)/[100] symmetric tilt grain boundary in YAG was produced by UHV diffusion bonding precisely oriented single crystals. The boundary has been characterized by HREM along two different directions, parallel and perpendicular to the tilt axis. Models of the atomic structure of the boundary were formed following the Coincident Site Lattice scheme. The resulting models are equivalent to twins formed at the atomic scale. The high resolution images show no rigid crystal translations away from the perfect mirror reflection relation. Comparison of the simulated images using the atomic model as input with the experimental images identifies the plane of mirror symmetry. The atomic model is shown to be in good agreement with the experimental images when viewed parallel to tilt axis, but disagrees with the images perpendicular to tilt axis. Agreement between simulated and experimental images can be improved by changing the composition of the grain boundary with respect to the bulk. To reach a more certain conclusion on the structure of the grain boundary will require additional theoretical calculations.

Campbell, G.H.; King, W.E.

1996-06-24T23:59:59.000Z

371

First Flight Tests for a Quadrotor UAV with Tilting Propellers Markus Ryll, Heinrich H. Bulthoff, and Paolo Robuffo Giordano  

E-Print Network (OSTI)

First Flight Tests for a Quadrotor UAV with Tilting Propellers Markus Ryll, Heinrich H. B¨ulthoff, and Paolo Robuffo Giordano Abstract-- In this work we present a novel concept of a quadrotor UAV show the capabilities of this new UAV concept. I. INTRODUCTION Common UAVs (Unmanned Aerial Vehicles

Paris-Sud XI, Université de

372

Limitations in solar module azimuth and tilt angles in building integrated photovoltaics at low latitude tropical sites in Brazil  

Science Journals Connector (OSTI)

Abstract Photovoltaic (PV) generation depends directly on the amount of radiation received by solar modules at a given temperature, and annual irradiation varies according to site location and PV array position. In this paper, the limitations and the solar irradiation levels received by building surfaces in different positions (with azimuth and tilt angle variation) in capital cities in Brazil are shown, making use of the Brazilian global horizontal solar irradiation data provided by the SWERA (Solar and Wind Energy Resource Assessment) project. These data were processed to generate figures on the irradiation at various PV module orientations and slopes for each city, which show the relative radiation levels received on specific azimuth and tilt angles in relation to the ideal position. Results were validated using four real and operating PV systems. In general, variations in azimuth or slope did not cause large annual irradiation losses up to around 20° tilt angles. This shows to PV system planners that under these fairly flexible conditions it is possible to install PV on any orientation, keeping high levels of annual irradiation, and that limitations in orientation and tilt can be relatively low. It also allows a quick analysis of PV retrofit in building-applied photovoltaics (BAPV), when seeking the best building surfaces to incorporate PV.

Ísis Portolan dos Santos; Ricardo Rüther

2014-01-01T23:59:59.000Z

373

6I).-TIEE TENCII RECORUITlENDED P O R CULTIIVATION I N SWEDEN. ]By FIEIY TILtYICLQRI.  

E-Print Network (OSTI)

6I).-TIEE TENCII RECORUITlENDED P O R CULTIIVATION I N SWEDEN. ]By FIEIY TILtYICLQRI. In Sweden \\vu pounds]. I n Sweden, when 'in suitable waters, like thoso in the northern part of the province of Snitlland, it reaches e weight of 6: or more pounds. I do not lrxiow how fast it grows in Sweden in a free

374

FlIGHT PATH FOLLOWING GUIDANCE FOR UNMANNED AIR VEHICLES WITH PAN-TILT CAMERA FOR TARGET OBSERVATION  

E-Print Network (OSTI)

Autonomous Vehicle (UAV) is equipped with a nose-mounted camera capable of pan and tilt rotation is affected by wind. Furthermore, the relative position of the sun can lead to glare and image overexposure. While the effect of wind can be improved by commanding a sideslip angle, image overexposure is avoided

Washington at Seattle, University of

375

Cone-beam mammo-computed tomography from data along two tilting arcs Hengyong Yu,b  

E-Print Network (OSTI)

Cone-beam mammo-computed tomography from data along two tilting arcs Kai Zeng,a Hengyong Yu . To address this problem, x-ray tomosynthesis and cone-beam computed tomography CT are two compelling from a limited num- ber of projections.4 Since its introduction in 1972, the area of tomosynthesis has

Virginia Tech

376

Magnetic particles confined in a modulated channel: structural transitions tunable by tilting a magnetic field  

E-Print Network (OSTI)

The ground state of colloidal magnetic particles in a modulated channel are investigated as function of the tilt angle of an applied magnetic field. The particles are confined by a parabolic potential in the transversal direction while in the axial direction a periodic substrate potential is present. By using Monte Carlo (MC) simulations, we construct a phase diagram for the different crystal structures as a function of the magnetic field orientation, strength of the modulated potential and the commensurability factor of the system. Interestingly, we found first and second order phase transitions between different crystal structures, which can be manipulated by the orientation of the external magnetic field. A re-entrant behavior is found between two- and four-chain configurations, with continuous second order transitions. Novel configurations are found consisting of frozen in solitons. By changing the orientation and/or strength of the magnetic field and/or the strength and the spatial frequency of the periodic substrate potential, the system transits through different phases.

J. E. Galván-Moya; D. Lucena; W. P. Ferreira; F. M. Peeters

2014-01-03T23:59:59.000Z

377

Test Problem: Tilted Rayleigh-Taylor for 2-D Mixing Studies  

SciTech Connect

The 'tilted-rig' test problem originates from a series of experiments (Smeeton & Youngs, 1987, Youngs, 1989) performed at AWE in the late 1980's, that followed from the 'rocket-rig' experiments (Burrows et al., 1984; Read & Youngs, 1983), and exploratory experiments performed at Imperial College (Andrews, 1986; Andrews and Spalding, 1990). A schematic of the experiment is shown in Figure 1, and comprises a tank filled with light fluid above heavy, and then 'tilted' on one side of the apparatus, thus causing an 'angled interface' to the acceleration history due to rockets. Details of the configuration given in the next chapter include: fluids, dimensions, and other necessary details to simulate the experiment. Figure 2 shows results from two experiments, Case 110 (which is the source for this test problem) that has an Atwood number of 0.5, and Case 115 (a secondary source described in Appendix B), with Atwood of 0.9 Inspection of the photograph in Figure 2 (the main experimental diagnostic) for Case 110. reveals two main areas for mix development; 1) a large-scale overturning motion that produces a rising plume (spike) on the left, and falling plume (bubble) on the right, that are almost symmetric; and 2) a Rayleigh-Taylor driven mixing central mixing region that has a large-scale rotation associated with the rising and falling plumes, and also experiences lateral strain due to stretching of the interface by the plumes, and shear across the interface due to upper fluid moving downward and to the right, and lower fluid moving upward and to the left. Case 115 is similar but differs by a much larger Atwood of 0.9 that drives a strong asymmetry between a left side heavy spike penetration and a right side light bubble penetration. Case 110 is chosen as the source for the present test problem as the fluids have low surface tension (unlike Case 115) due the addition of a surfactant, the asymmetry small (no need to have fine grids for the spike), and there is extensive reasonable quality photographic data. The photographs in Figure 2 also reveal the appearance of a boundary layer at the left and right walls; this boundary layer has not been included in the test problem as preliminary calculations suggested it had a negligible effect on plume penetration and RT mixing. The significance of this test problem is that, unlike planar RT experiments such as the Rocket-Rig (Youngs, 1984), Linear Electric Motor - LEM (Dimonte, 1990), or the Water Tunnel (Andrews, 1992), the Tilted-Rig is a unique two-dimensional RT mixing experiment that has experimental data and now (in this TP) Direct Numerical Simulation data from Livescu and Wei. The availability of DNS data for the tilted-rig has made this TP viable as it provides detailed results for comparison purposes. The purpose of the test problem is to provide 3D simulation results, validated by comparison with experiment, which can be used for the development and validation of 2D RANS models. When such models are applied to 2D flows, various physics issues are raised such as double counting, combined buoyancy and shear, and 2-D strain, which have not yet been adequately addressed. The current objective of the test problem is to compare key results, which are needed for RANS model validation, obtained from high-Reynolds number DNS, high-resolution ILES or LES with explicit sub-grid-scale models. The experiment is incompressible and so is directly suitable for algorithms that are designed for incompressible flows (e.g. pressure correction algorithms with multi-grid); however, we have extended the TP so that compressible algorithms, run at low Mach number, may also be used if careful consideration is given to initial pressure fields. Thus, this TP serves as a useful tool for incompressible and compressible simulation codes, and mathematical models. In the remainder of this TP we provide a detailed specification; the next section provides the underlying assumptions for the TP, fluids, geometry details, boundary conditions (and alternative set-ups), initial conditions, and acceleration history (an

Andrews, Malcolm J. [Los Alamos National Laboratory; Livescu, Daniel [Los Alamos National Laboratory; Youngs, David L. [AWE

2012-08-14T23:59:59.000Z

378

Recording and interpretation/analysis of tilt signals with five ASKANIA borehole tiltmeters at the KTB  

Science Journals Connector (OSTI)

In June 2003 a large scale injection experiment started at the Continental Deep Drilling site (KTB) in Germany. A tiltmeter array was installed which consisted of five high resolution borehole tiltmeters of the ASKANIA type also equipped with three dimensional seismometers. For the next 11 months 86 000 m 3 were injected into the KTB pilot borehole 4000 m deep. The average injection rate was approximately 200 l ? min . The research objective was to observe and to analyzedeformation caused by the injection into the upper crust at the kilometer range. A new data acquisition system was developed by Geo-Research Center Potsdam (GFZ) to master the expected huge amount of seismic and tilt data. Furthermore it was necessary to develop a new preprocessing software called PREANALYSE for long-period time series. This software includes different useful functions such as step and spike correction interpolation filtering and spectral analysis. This worldwide unique installation offers the excellent opportunity of the separation of signals due to injection and due to environment by correlation of the data of the five stations with the ground water table and meteorological data.

André Gebauer; Thomas Jahr; Gerhard Jentzsch

2007-01-01T23:59:59.000Z

379

A free real-time hourly tilted solar irradiation data Website for Europe  

E-Print Network (OSTI)

The engineering of solar power applications, such as photovoltaic energy (PV) or thermal solar energy requires the knowledge of the solar resource available for the solar energy system. This solar resource is generally obtained from datasets, and is either measured by ground-stations, through the use of pyranometers, or by satellites. The solar irradiation data are generally not free, and their cost can be high, in particular if high temporal resolution is required, such as hourly data. In this work, we present an alternative method to provide free hourly global solar tilted irradiation data for the whole European territory through a web platform. The method that we have developed generates solar irradiation data from a combination of clear-sky simulations and weather conditions data. The results are publicly available for free through Soweda, a Web interface. To our knowledge, this is the first time that hourly solar irradiance data are made available online, in real-time, and for free, to the public. The ac...

Leloux, Jonathan; Gonzalez-Bonilla, Loreto

2014-01-01T23:59:59.000Z

380

Brazil Latitude Tilted Solar Radiation Model (10km) from INPE and LABSOLAR  

Open Energy Info (EERE)

10km) from INPE and LABSOLAR 10km) from INPE and LABSOLAR Dataset Summary Description (Abstract): Latitude tilted solar radiation in kWh/m2/day for 1 year organized into cells with 10km x 10km (Purpose): The BRASIL-SR model and the SPRING software (both developed by INPE -National Institute for Space Research) were used to produce the dataset and SHAPE files (Supplemental Information): The assessment of reliability levels of the BRASIL-SR model were performed through the evaluation of the deviations shown by the estimated values for solar radiation flux vis-à-vis the values measured at the surface (ground truth). This evaluation was done in two phases. The first phase consisted in an inter-comparison between the core radiation transfer models adopted by the SWERA Project to map the solar energy in the various countries participating in the project. The HELIOSAT model took part in this phase like benchmark due to its employment to map solar energy resources incountries from European Union. In the second phase, the solar flux estimates providedby the BRASIL-SR model were compared with measured values acquired at several solarimetric stations spread along the Brazilian territory

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Application and Continued Development of Thin Faraday Collectors as a Lost Ion Diagnostic for Tokamak Fusion Plasmas  

SciTech Connect

This report summarizes the accomplishment of sixteen years of work toward the development of thin foil Faraday collectors as a lost energetic ion diagnostic for high temperature magnetic confinement fusion plasmas. Following initial, proof of principle accelerator based studies, devices have been tested on TFTR, NSTX, ALCATOR, DIII-D, and JET (KA-1 and KA-2). The reference numbers refer to the attached list of publications. The JET diagnostic KA-2 continues in operation and hopefully will provide valuable diagnostic information during a possible d-t campaign on JET in the coming years. A thin Faraday foil spectrometer, by virtue of its radiation hardness, may likewise provide a solution to the very challenging problem of lost alpha particle measurements on ITER and other future burning plasma machines.

F. Ed Cecil

2011-06-30T23:59:59.000Z

382

Effects of collector radius and chimney height on power output of a solar chimney power plant with turbines  

Science Journals Connector (OSTI)

A comprehensive theoretical model is proposed for the performance evaluation of a solar chimney power plant (SCPP), and has been verified by the experimental data of the Spanish prototype. This model takes account of the effects of flow and heat losses, and the temperature lapse rates inside and outside the chimney. There is a maximum power output for a certain SCPP under a given solar radiation condition, due to flow and heat losses and the installation of the turbines. In addition, the design flow rate of the turbine in the SCPP system is found beneficial for power output when it is lower than that at the maximum power point. Furthermore, a limitation on the maximum collector radius exists for the maximum attainable power of the SCPP; whereas, no such limitation exists for chimney height in terms of contemporary construction technology.

Jing-yin Li; Peng-hua Guo; Yuan Wang

2012-01-01T23:59:59.000Z

383

NREL GIS Data: Hawaii High Resolution Photovoltaic | OpenEI  

Open Energy Info (EERE)

Photovoltaic Photovoltaic Dataset Summary Description Abstract - Monthly and annual average solar resource potential for the State of Hawaii. Purpose - Provide information on the solar resource potential for Hawaii. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented due south at an angle from horizontal equal to the latitude of the collector location. Supplemental Info - This data provides monthly average and annual average daily total solar resource averaged over surface cells of 0.1 degrees in both latitude and longitude, or about 10 km in size. This data was developed using the State University of New York/Albany satellite radiation model. This model was developed by Dr. Richard Perez and collaborators at the National Renewable Energy Laboratory and other universities for the U.S. Department of Energy. Specific information about this model can be found in Perez, et al. (2002). This model uses hourly radiance images from geostationary weather satellites, daily snow cover data, and monthly averages of atmospheric water vapor, trace gases, and the amount of aerosols in the atmosphere to calculate the hourly total insolation (sun and sky) falling on a horizontal surface. Atmospheric water vapor, trace gases, and aerosols are derived from a variety of sources. The procedures for converting the collector at latitude tilt are described in Marion and Wilcox (1994). Where possible, existing ground measurement stations are used to validate the data. Nevertheless, there is uncertainty associated with the meterological input to the model, since some of the input parameters are not avalable at a 10km resolution. As a result, it is believed that the modeled values are accurate to approximately 10% of a true measured value within the grid cell. Due to terrain effects and other micoclimate influences, the local cloud cover can vary significantly even within a single grid cell. Furthermore, the uncertainty of the modeled estimates increase with distance from reliable measurement sources and with the complexity of the terrain.

384

Solar Water Heater Basics | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Solar Water Heater Basics Solar Water Heater Basics Solar Water Heater Basics August 19, 2013 - 3:01pm Addthis Illustration of an active, closed loop solar water heater. A large, flat panel called a flat plate collector is connected to a tank called a solar storage/backup water heater by two pipes. One of these pipes runs through a cylindrical pump into the bottom of the tank, where it becomes a coil called a double-wall heat exchanger. This coil runs up through the tank and out again to the flat plate collector. Antifreeze fluid runs only through this collector loop. Two pipes run out the top of the water heater tank; one is a cold water supply into the tank, and the other sends hot water to the house. Solar water heaters use the sun's heat to provide hot water for a home or

385

Effects of head-up tilt on mean arterial pressure, heart rate, and regional cardiac output distribution in aging rats  

E-Print Network (OSTI)

Approved by: Chair of Committee, Michael Delp Committee Members, Robert Armstrong Judy Muller-Delp Janet r Head of Department, Steve M. Dorman December 2005 Major Subject: Kinesiology iii ABSTRACT Effects of Head-up Tilt... Armstrong, and Dr. Janet Parker for their patience, guidance, and support thoughout the course of this research. vi TABLE OF CONTENTS Page ABSTRACT????????????????????????.. iii ACKNOWLEDGEMENTS??????????????????.. v TABLE OF CONTENTS...

Ramsey, Michael Wiechmann

2006-04-12T23:59:59.000Z

386

Influence of circumferential solar heat flux distribution on the heat transfer coefficients of linear Fresnel collector absorber tubes  

Science Journals Connector (OSTI)

Abstract The absorber tubes of solar thermal collectors have enormous influence on the performance of the solar collector systems. In this numerical study, the influence of circumferential uniform and non-uniform solar heat flux distributions on the internal and overall heat transfer coefficients of the absorber tubes of a linear Fresnel solar collector was investigated. A 3D steady-state numerical simulation was implemented based on ANSYS Fluent code version 14. The non-uniform solar heat flux distribution was modelled as a sinusoidal function of the concentrated solar heat flux incident on the circumference of the absorber tube. The k–? model was employed to simulate the turbulent flow of the heat transfer fluid through the absorber tube. The tube-wall heat conduction and the convective and irradiative heat losses to the surroundings were also considered in the model. The average internal and overall heat transfer coefficients were determined for the sinusoidal circumferential non-uniform heat flux distribution span of 160°, 180°, 200° and 240°, and the 360° span of circumferential uniform heat flux for 10 m long absorber tubes of different inner diameters and wall thicknesses with thermal conductivity of 16.27 W/mK between the Reynolds number range of 4000 and 210,000 based on the inlet temperature. The results showed that the average internal heat transfer coefficients for the 360° span of circumferential uniform heat flux with different concentration ratios on absorber tubes of the same inner diameters, wall thicknesses and thermal conductivity were approximately the same, but the average overall heat transfer coefficient increased with the increase in the concentration ratios of the uniform heat flux incident on the tubes. Also, the average internal heat transfer coefficient for the absorber tube with a 360° span of uniform heat flux was approximately the same as that of the absorber tubes with the sinusoidal circumferential non-uniform heat flux span of 160°, 180°, 200° and 240° for the heat flux of the same concentration ratio, but the average overall heat transfer coefficient for the uniform heat flux case was higher than that of the non-uniform flux distributions. The average axial local internal heat transfer coefficient for the 360° span of uniform heat flux distribution on a 10 m long absorber tube was slightly higher than that of the 160°, 200° and 240° span of non-uniform flux distributions at the Reynolds number of 4 000. The average internal and overall heat transfer coefficients for four absorber tubes of different inner diameters and wall thicknesses and thermal conductivity of 16.27 W/mK with 200° span of circumferential non-uniform flux were found to increase with the decrease in the inner-wall diameter of the absorber tubes. The numerical results showed good agreement with the Nusselt number experimental correlations for fully developed turbulent flow available in the literature.

Izuchukwu F. Okafor; Jaco Dirker; Josua P. Meyer

2014-01-01T23:59:59.000Z

387

Static characteristics and rotordynamic coefficients of a four-pad tilting-pad journal bearing with ball-in-socket pivots in load-between-pad configuration  

E-Print Network (OSTI)

Static characteristics and rotordynamic coefficients were experimentally determined for a four-pad tilting-pad journal bearing with ball-in-socket pivots in loadbetween- pad configuration. A frequency-independent [M]-[C]-[K] model fit...

Harris, Joel Mark

2009-05-15T23:59:59.000Z

388

Transpired Solar Collector at NREL's Waste Handling Facility Uses Solar Energy to Heat Ventilation Air (Fact Sheet) (Revised), Federal Energy Management Program (FEMP)  

NLE Websites -- All DOE Office Websites (Extended Search)

Highlights Highlights System Size 300 ft 2 transpired solar collector Energy Production About 125 Btu/hr/ft 2 (400 W/m 2 ) of heat delivery under ideal conditions (full sun) Installation Date 1990 Motivation Provide solar-heated ventilation air to offset some of the heating with conventional electric resistance heaters Annual Savings 14,310 kWh (49 million Btu/yr) or about 26% of the energy required to heat the facility's ventilation air System Details Components Black, 300 ft 2 corrugated aluminum transpired solar collector with a porosity of 2%; bypass damper; two-speed 3000 CFM vane axial supply fan; electric duct heater; thermostat controller Storage None Loads 188 million Btu/year (55,038 kWh/year) winter average to heat 1,300 ft 2 Waste Handling Facility

389

Transpired Solar Collector at NREL's Waste Handling Facility Uses Solar Energy to Heat Ventilation Air (Fact Sheet) (Revised), Federal Energy Management Program (FEMP)  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Highlights Highlights System Size 300 ft 2 transpired solar collector Energy Production About 125 Btu/hr/ft 2 (400 W/m 2 ) of heat delivery under ideal conditions (full sun) Installation Date 1990 Motivation Provide solar-heated ventilation air to offset some of the heating with conventional electric resistance heaters Annual Savings 14,310 kWh (49 million Btu/yr) or about 26% of the energy required to heat the facility's ventilation air System Details Components Black, 300 ft 2 corrugated aluminum transpired solar collector with a porosity of 2%; bypass damper; two-speed 3000 CFM vane axial supply fan; electric duct heater; thermostat controller Storage None Loads 188 million Btu/year (55,038 kWh/year) winter average to heat 1,300 ft 2 Waste Handling Facility

390

Investigation Of The Friction Factor Behavior for Flat Plate Tests Of Smooth And Roughened Surfaces With Supply Pressures Up To 84 Bars  

E-Print Network (OSTI)

friction factor data and measure dynamic pressure oscillations. A detailed description of the test facility is described, and a theory for determining the friction factor is reviewed. Three clearances were investigated: 0.635, 0.381, and 0.254 mm. Tests...

Kheireddin, Bassem A.

2010-10-12T23:59:59.000Z

391

The effect of injection hole orientation on flat-plate film cooling and heat transfer using a transient liquid crystal technique  

E-Print Network (OSTI)

-UP. . . . . EXPERIMENTAL PROCEDURE THEORY OF OPERATION. . . RESULTS AND DISCUSSION. . Heat transfer. . Local Spanwise Variations. . Effect of Density Ratio and Compound Angle. . . . Momentuin Flux Ratio. Film Effectiveness. . . . . . Local Spanwise Variations... cavity for mixing and ejecta through the holes onto the test plate. Temperature controllers for the mainstream and coolant flows allow for desired temperature levels to be reached and inaintained. The coolant temperature is monitored at an injection...

Zapata, Dyrk Oliver

2012-06-07T23:59:59.000Z

392

An experimental investigation of the rolling moment on a flat plate in the presence of a free vortex of known strength  

E-Print Network (OSTI)

not affect their vertical or lateral positioning. The vortex probe assembly is shown in Figure 2. A comparison of the free-stream velocities obtained from the vortex probe assembly and a standard pitot-static tube revealed a difference of less than one...AN EXPERIMENTAL 1NVES1'IGATION OF THE ROLLING MOMENT ON A ILAT PLATE IN THE ?RESENCE OP A FREE VORTEX OF KNOWN STRENGTH A Thesis by MAURICE VERNE VAN DUSEN, JR. Submitted to the Graduate College of Teras A&M University in partial fulfillment...

Van Dusen, Maurice Verne

2012-06-07T23:59:59.000Z

393

Theoretical considerations of static and dynamic characteristics of air foil thrust bearing with tilt and slip flow  

Science Journals Connector (OSTI)

The thrust pad of the rotor is used to sustain the axial force generated due to the pressure difference between the compressor and turbine sides of turbomachinery such as gas turbines, compressors, and turbochargers. Furthermore, this thrust pad has a role to maintain and determines the attitude of the rotor. In a real system, it also helps reinforce the stiffness and damping of the journal bearing. This study was performed for the purpose of analyzing the characteristics of the air foil thrust bearing. The model for the air foil thrust bearing used in this study is composed of two parts: one is an inclined plane, which plays a role in increasing the load carrying capacity using the physical wedge effect, and the other is a flat plane. This study mainly consists of three parts. First, the static characteristics were obtained over the region of the thin air film using the finite-difference method (FDM) and the bump foil characteristics using the finite-element method (FEM). Second, the analysis of the dynamic characteristics was conducted by perturbation method. For more exact calculation, the rarefaction gas coefficients perturbed about the pressure and film thickness were taken into consideration. At last, the static and dynamic characteristics of the tilting condition of the thrust pad were obtained. Furthermore, the load carrying capacity and torque were calculated for both tilting and nontilting conditions. From this study, several results were presented: (1) the stiffness and damping of the bump foil under the condition of the various bump parameters, (2) the load carrying capacity and bearing torque at the tilting state, (3) the bearing performance for various bearing parameters, and (4) the effects considering the rarefaction gas coefficients.

Dong-Jin Park; Chang-Ho Kim; Gun-Hee Jang; Yong-Bok Lee

2008-01-01T23:59:59.000Z

394

Tilting for perfusion: Head-up position during cardiopulmonary resuscitation improves brain flow in a porcine model of cardiac arrest  

Science Journals Connector (OSTI)

AbstractIntroduction Cerebral perfusion is compromised during cardiopulmonary resuscitation (CPR). We hypothesized that beneficial effects of gravity on the venous circulation during CPR performed in the head-up tilt (HUT) position would improve cerebral perfusion compared with supine or head-down tilt (HDT). Methods Twenty-two pigs were sedated, intubated, anesthetized, paralyzed and placed on a tilt table. After 6 min of untreated ventricular fibrillation (VF) CPR was performed on 14 pigs for 3 min with an automated CPR device called LUCAS (L) plus an impedance threshold device (ITD), followed by 5 min of L-CPR + ITD at 0° supine, 5 min at 30° HUT, and then 5 min at 30° HDT. Microspheres were used to measure organ blood flow in 8 pigs. L-CPR + ITD was performed on 8 additional pigs at 0°, 20°, 30°, 40°, and 50° HUT. Results Coronary perfusion pressure was 19 ± 2 mmHg at 0° vs. 30 ± 3 at 30° HUT (p Brain–blood flow was 0.19 ± 0.04 ml min?1 g?1 at 0° vs. 0.27 ± 0.04 at 30° HUT (p = 0.01) and 0.14 ± 0.06 at 30° HDT (p = 0.16). Heart blood flow was not significantly different between interventions. With 0, 10, 20, 30, 40 and 50° HUT, ICP values were 21 ± 2, 16 ± 2, 10 ± 2, 5 ± 2, 0 ± 2, ?5 ± 2 respectively, (p brain flow whereas HUT significantly lowered ICP and improved cerebral perfusion. Further studies are warranted to explore this new resuscitation concept.

Guillaume Debaty; Sang Do Shin; Anja Metzger; Taeyun Kim; Hyun Ho Ryu; Jennifer Rees; Scott McKnite; Timothy Matsuura; Michael Lick; Demetris Yannopoulos; Keith Lurie

2014-01-01T23:59:59.000Z

395

Experimental and numerical heat transfer analysis of a V-cavity absorber for linear parabolic trough solar collector  

Science Journals Connector (OSTI)

Abstract In the present study, a V-cavity absorber with rectangular fins that can be used in the linear parabolic trough collector (PTC) system was proposed and investigated both theoretically and experimentally. The optical performance of the absorber was studied by means of Monte-Carlo ray-tracing (MCRT) method. An energy balance model and a more detailed three-dimensional numerical model were developed to analyze the flow and heat transfer characteristics. Moreover, an experimental setup was built to validate the theoretical analysis. A reasonable agreement between the theoretical and experimental results was achieved, which proves the feasibility and reliability of the models. The results show that the sunlight could be reflected repeatedly by the triangle shape and nearly no sunlight escapes. The absorber with rectangular fins has a better heat transfer performance with higher outlet temperature of heat transfer fluid (HTF), lower temperature of heating surface and lower heat loss than those of absorber without fins. The effects of heat flux distribution, mass flow rate and direct normal irradiance on the heat transfer performance were further discussed. In addition, the variations of the heat transfer coefficient along z axial direction with different mass flow rates were also calculated based on the numerical results.

X. Xiao; P. Zhang; D.D. Shao; M. Li

2014-01-01T23:59:59.000Z

396

Analysis of a new thermodynamic cycle for combined power and cooling using low and mid temperature solar collectors  

SciTech Connect

A combined thermal power and cooling cycle is proposed which combines the Rankine and absorption refrigeration cycles. It can provide power output as well as refrigeration with power generation as a primary goal. Ammonia-water mixture is used as a working fluid. The boiling temperature of the ammonia-water mixture increases as the boiling process proceeds until all liquid is vaporized, so that a better thermal match is obtained in the boiler. The proposed cycle takes advantage of the low boiling temperature of ammonia vapor so that it can be expanded to a low temperature while it is still in a vapor state or a high quality two phase state. This cycle is ideally suited for solar thermal power using low cost concentrating collectors, with the potential to reduce the capital cost of a solar thermal power plant. The cycle can also be used as a bottoming cycle for any thermal power plant. This paper presents a parametric analysis of the proposed cycle.

Goswami, D.Y.; Xu, F. [Univ. of Florida, Gainesville, FL (United States). Solar Energy and Energy Conversion Lab.

1999-05-01T23:59:59.000Z

397

Standard test method for isotopic analysis of uranium hexafluoride by double standard single-collector gas mass spectrometer method  

E-Print Network (OSTI)

1.1 This is a quantitative test method applicable to determining the mass percent of uranium isotopes in uranium hexafluoride (UF6) samples with 235U concentrations between 0.1 and 5.0 mass %. 1.2 This test method may be applicable for the entire range of 235U concentrations for which adequate standards are available. 1.3 This test method is for analysis by a gas magnetic sector mass spectrometer with a single collector using interpolation to determine the isotopic concentration of an unknown sample between two characterized UF6 standards. 1.4 This test method is to replace the existing test method currently published in Test Methods C761 and is used in the nuclear fuel cycle for UF6 isotopic analyses. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro...

American Society for Testing and Materials. Philadelphia

2010-01-01T23:59:59.000Z

398

Load Tilt and Body Tilt at Bidston  

Science Journals Connector (OSTI)

......to Tidal Load,Memoirs of the Imperial Marine Observatory, 1, No. 1, 1922 June...that the possibilities of error due to wear in the cone and cup should be made known...1932 September. Memoirs of the Imperial Marine Observatory, I, No. I, 1922June. the......

A. T. Doodson; R. H. Corkan

1934-05-01T23:59:59.000Z

399

Optimization of non-evacuated receiver of solar collector having non-uniform temperature distribution for minimum heat loss  

Science Journals Connector (OSTI)

Abstract The present paper contains a numerical study of heat loss from a non-evacuated receiver typically used in parabolic trough collectors. To calculate temperature distributions on the receiver pipe (TP), an energy balance has been established over the entire cross-section of the receiver pipe at different fluid temperatures. In the energy balance, the flux distribution has been estimated by assuming normal incidence of solar insolation considering the sun as a point source. The temperature distributions of the receiver pipe are found, as per expectation, to be non-uniform. These temperature distributions have been fitted by sinusoidal and step functions and are used as temperature boundary conditions in a CFD study to optimize the size of the receiver. The mechanisms of heat loss that have been considered in this study are heat loss from (1) pipe to glass tube by conduction, convection and radiation and (2) glass tube to surrounding by convection (natural and forced) and radiation. The values of diameters of receiver pipe taken in this study are 33 mm, 48 mm, 60 mm, 70 mm, 89 mm and 102 mm. The radius ratio (RR) varied from 1.2 to 3 by changing diameter of glass tube. It is observed that, the critical value of RR for minimum heat loss is dependent upon receiver pipe diameter (DPo). The critical values of RR for pipe diameter (DPo) 33 mm, 48 mm, 60 mm, 70 mm, 89 mm and 102 mm are 1.5, 1.4, 1.375, 1.35, 1.3 and 1.25 respectively. The value of critical RR is lower for higher values of pipe diameter. The value of critical RR for a particular diameter of receiver is independent of receiver temperature and external wind velocity. Comparison of heat losses in non-uniform and uniform temperature cases shows that the values of heat losses in the two cases differ only by 1.5%.

Ramchandra G. Patil; Sudhir V. Panse; Jyeshtharaj B. Joshi

2014-01-01T23:59:59.000Z

400

Technical evaluation of a solar heating system having conventional hydronic solar collectors and a radiant panel slab. Final report  

SciTech Connect

A simple innovative solar heating design (Solar Option One) using conventional hydronic solar collectors and a radiant panel slab was constructed. An objective of hybrid solar design is to combine the relative advantages of active and passive design approaches while minimizing their respective disadvantages. A test house using the Solar Option One heating system was experimentally monitored to determine its energy based performance during the 1982-83 heating season. The test residence is located in Lyndonville, Vermont, an area which has a characteristically cold and cloudy climate. The two story residence has a floor area of about 1400 square feet and is constructed on a 720 square foot 5.5 inch thick floor slab. A 24 inch packed gravel bed is located beneath the slab and the slab-gravel bed is insulated by two inches of polystyrene insulation. The test building is of frame construction and uses insulation levels which have become commonplace throughout the country. The structure would not fall into the superinsulated category but was tightly constructed so as to have a low infiltration level. The building is sun-tempered in that windows were concentrated somewhat on the South side and all but avoided on the North. A solar greenhouse on the South side of the building was closed off from the structure permanently throughout the testing so as to better observe the solar heating invention without confounding variables. The monitoring equipment generated an internal gain of about 17,000 BTUs per day, roughly the equivalent of occupancy by two persons. A full description of the experimental testing program is given. System efficiency and performance are reported.

Starr, R.J.

1984-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Energy modeling of photovoltaic thermal systems with corrugated unglazed transpired solar collectors – Part 1: Model development and validation  

Science Journals Connector (OSTI)

Abstract Building-integrated photovoltaic–thermal (BIPV/T) systems with unglazed transpired solar collectors (UTCs) can provide a key solution for on-site electricity and thermal energy generation. Although the energy saving potential of this technology is significant, no systematic thermal analysis model has been developed for optimal system design and integration with building operation. This paper is the first of two companion papers focused on modeling and performance analysis of BIPV/T systems with UTC. In Part 1, energy models are presented for two configurations: UTC only and UTC with PV panels, to predict the cavity exit air temperature and plate surface temperature with weather (incident solar radiation, ambient air temperature, dew point temperature and wind speed) and design (airflow rate or suction velocity and geometry) parameters used as inputs. Nusselt number and effectiveness correlations, representing both the exterior and interior convective heat transfer processes, have been obtained from experimentally validated, three-dimensional, Reynolds-Averaged Navier–Stokes (RANS), Computational Fluid Dynamics (CFD) simulations, using high resolution grids and the ReNormalization Group Methods k–? (RNG k–?) turbulence closure model. The energy models were validated with measurements in an outdoor test-facility. Good agreement was observed between the model prediction and the experimental data, with the root mean square error (RMSE) being within 1 °C for the UTC-only model and within 2 °C for the model of UTC with PV modules. In the companion paper, Part 2, the effects of important parameters on system performance are demonstrated based on information from the literature and simulations using CFD and energy models. The optimal geometry is investigated for both configurations and the performance curves, under different levels of solar radiation, wind speed and suction velocity, are presented to provide guidelines for system design.

Siwei Li; Panagiota Karava; Sam Currie; William E. Lin; Eric Savory

2014-01-01T23:59:59.000Z

402

Carribean Islands | OpenEI  

Open Energy Info (EERE)

Carribean Islands Carribean Islands Dataset Summary Description (Abstract): Monthly Average Solar Resource for horizontal flat-plate collectors, for Mexico, Central America, and the Caribbean Islands. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented horizontally. Source NREL Date Released January 31st, 2004 (10 years ago) Date Updated October 30th, 2007 (7 years ago) Keywords Carribean Islands Central America GEF GHI GIS Mexico NREL solar SWERA UNEP Data text/csv icon Download Data (csv, 370.6 KiB) application/zip icon Download Shapefile (zip, 244 KiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage

403

Solar: monthly and annual average global horizontal (GHI) GIS data at 40km  

Open Energy Info (EERE)

Nepal from NREL Nepal from NREL Dataset Summary Description (Abstract): Monthly average solar resource for horizontal flat-plate collectors for Nepal. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented horizontally. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The data were developed from NREL's Climatological Solar Radiation (CSR) Model. This model uses information on cloud cover, atmospheric water

404

GEF | OpenEI  

Open Energy Info (EERE)

GEF GEF Dataset Summary Description (Abstract): Monthly average solar resource for horizontal flat-plate collectors for China. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented horizontally. Source NREL Date Released April 12th, 2005 (9 years ago) Date Updated October 30th, 2007 (7 years ago) Keywords China GEF GHI GIS NREL solar SWERA UNEP Data application/zip icon Download Shapefile (zip, 629.4 KiB) text/csv icon Download Data (csv, 779.1 KiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period 01/01/1985 - 12/31/1991 License License Open Data Commons Public Domain Dedication and Licence (PDDL)

405

China | OpenEI  

Open Energy Info (EERE)

China China Dataset Summary Description (Abstract): Monthly average solar resource for horizontal flat-plate collectors for China. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented horizontally. Source NREL Date Released April 12th, 2005 (9 years ago) Date Updated October 30th, 2007 (7 years ago) Keywords China GEF GHI GIS NREL solar SWERA UNEP Data application/zip icon Download Shapefile (zip, 629.4 KiB) text/csv icon Download Data (csv, 779.1 KiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period 01/01/1985 - 12/31/1991 License License Open Data Commons Public Domain Dedication and Licence (PDDL)

406

Solar: monthly and annual average global horizontal (GHI) GIS data at 40km  

Open Energy Info (EERE)

Ghana from NREL Ghana from NREL Dataset Summary Description (Abstract): Monthly Average Solar Resource for horizontal flat-plate collectors for Ghana. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented horizontally. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The data were developed from NREL's Climatological Solar Radiation (CSR) Model. This model uses information on cloud cover, atmospheric water

407

Solar: monthly global horizontal (GHI) GIS data at 10km resolution for  

Open Energy Info (EERE)

Central America from SUNY Central America from SUNY Dataset Summary Description (Abstract): Monthly Average Solar Resource for horizontal flat-plate solar collectors for Central America (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a horizontal flat-plate solar collector, such as a Photovoltaic (PV) solar panel. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 10 km by 10 km in size. The solar resource value is represented as kilowatt-hours per square meter per day for each month. The data were developed from the State University of New York's (SUNY) GOES satellite solar model.

408

Solar: monthly and annual average global horizontal (GHI) GIS data at 40km  

Open Energy Info (EERE)

Brazil from NREL Brazil from NREL Dataset Summary Description (Abstract): Monthly average solar resource for horizontal flat-plate collectors for Brazil. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented horizontally. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The data were developed from NREL's Climatological Solar Radiation (CSR) Model. This model uses information on cloud cover, atmospheric water

409

Solar: monthly and annual average global horizontal (GHI) GIS data at 40km  

Open Energy Info (EERE)

Kenya from NREL Kenya from NREL Dataset Summary Description (Abstract): Monthly average solar resource for horizontal flat-plate collectors for Kenya. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented horizontally. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The data were developed from NREL's Climatological Solar Radiation (CSR) Model. This model uses information on cloud cover, atmospheric water

410

Solar: monthly and annual average global horizontal (GHI) GIS data at 40km  

Open Energy Info (EERE)

Sri Lanka from NREL Sri Lanka from NREL Dataset Summary Description (Abstract): Monthly Average Solar Resource for horizontal flat-plate collectors, for Sri Lanka (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented horizontally. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The data were developed from NREL's Climatological Solar Radiation (CSR) Model. This model uses information on cloud cover, atmospheric water

411

Solar: monthly global horizontal (GHI) GIS data at 40km resolution for  

Open Energy Info (EERE)

40km resolution for 40km resolution for Bangladesh from NREL Dataset Summary Description (Abstract): Monthly average solar resource for horizontal flat-plate collectors for Bangladesh. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented horizontally. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The data were developed from NREL's Climatological Solar Radiation (CSR) Model. This model uses information on cloud cover, atmospheric water

412

Study of the interaction of solutes with ?5 (013) tilt grain boundaries in iron using density-functional theory  

SciTech Connect

Substitutional alloying elements significantly affect the recrystallization and austenite-ferrite phase transformation rates in steels. The atomistic mechanisms of their interaction with the interfaces are still largely unexplored. Using density functional theory, we determine the segregation energies between commonly used alloying elements and the ?5 (013) tilt grain boundary in bcc iron. We find a strong solute-grain boundary interaction for Nb, Mo, and Ti that is consistent with experimental observations of the effects of these alloying elements on delaying recrystallization and the austenite-to-ferrite transformation in low-carbon steels. In addition, we compute the solute-solute interactions as a function of solute pair distance in the grain boundary, which suggest co-segregation for these large solutes at intermediate distances in striking contrast to the bulk.

Jin, Hao; Militzer, Matthias [Centre for Metallurgical Process Engineering, The University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada); Elfimov, Ilya [Quantum Matter Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada)

2014-03-07T23:59:59.000Z

413

A self-consistent regime of generation of terahertz radiation by an optical pulse with a tilted intensity front  

SciTech Connect

We derived a self-consistent system of nonlinear wave equations describing the terahertz generation in dielectric uniaxial crystals by optical pulsed radiation with a tilted wavefront. The numerical analysis of the system of equations showed that the generation of a broadband one-period terahertz signal is accompanied by a red shift of the carrier frequency of the optical pulse, the magnitude of the shift being proportional to the pulse intensity. The generation efficiency with respect to energy reached a maximum at a certain distance of propagation in the crystal, after which the efficiency decreased. A satisfactory agreement was obtained between theoretical calculations and experimental data of other investigations. (generation of terahertz radiation)

Bugai, A N; Sazonov, S V; Shashkov, Andrei Yu

2012-11-30T23:59:59.000Z

414

An isoviscous, isothermal model investigating the influence of hydrostatic recesses on a spring-supported tilting pad thrust bearing  

Science Journals Connector (OSTI)

Tilting-pad hydrodynamic thrust bearings are used in hydroelectric power stations around the world, reliably supporting turbines weighing hundreds of tonnes, over decades of service. Newer designs incorporate hydrostatic recesses machined into the sector-shaped pads.With the aid of external oil pressurisation at low rotational speeds, oil film thickness is increased, thereby reducing friction and wear to the benefit of service life and reliability. It follows that older generating plants, lacking such assistance, stand to benefit from being retrofitted with hydrostatic lubrication systems. The design process is not trivial however – the need to increase the groove area to permit spontaneous lifting of the turbine under hydrostatic operation conflicts with the need to preserve performance of the original plane pad design. A haphazardly designed recess can change the pressure distribution of the oil film in such a way as to tilt the pad away from its optimum position. This may lead to reduced oil film thickness and increased temperature, which is concomitant with reduced mechanical efficiency and increased risk of damage to the bearing surfaces. It is therefore, inadvisable to ignore the presence of grooves in simulations. In this work, a numerical study of a sector-shaped pad is undertaken to understand how recess size and shape can affect the performance of a typical bearing. An isoviscous, isothermal model has been used in this instance because the operating conditions of the turbine in question were shown not to be severe enough to warrant the computational expense of a fully coupled thermoelastic hydrodynamic model.

Dennis V. De Pellegrin; Douglas J. Hargreaves

2012-01-01T23:59:59.000Z

415

Open cycle liquid desiccant dehumidifier and hybrid solar/electric absorption refrigeration system. Annual report, January 1993--December 1993. Calendar year 1993  

SciTech Connect

This annual report presents work performed during calendar year 1993 by the Florida Solar Energy Center under contract to the US Department of Energy. Two distinctively different solar powered indoor climate control systems were analyzed: the open cycle liquid desiccant dehumidifier, and an improved efficiency absorption system which may be fired by flat plate solar collectors. Both tasks represent new directions relative to prior FSEC research in Solar Cooling and Dehumidification.

Nimmo, B.G.; Thornbloom, M.D.

1995-04-01T23:59:59.000Z

416

Solar hot water system installed at Las Vegas, Nevada. Final report  

SciTech Connect

The solar hot water system installed at LaQuinta Motor Inn Inc., at Las Vegas, Nevada is described. The Inn is a three-story building with a flat roof for installation of the solar panels. The system consists of 1200 square feet of liquid flat plate collectors, a 2500 gallon insulated vertical steel storage tank, two heat exchangers and pumps and controls. The system was designed to supply approximately 74 percent of the total hot water load.

None

1981-01-01T23:59:59.000Z

417

Solar heating and cooling system installed at RKL Controls Company, Lumberton, New Jersey. Final report  

SciTech Connect

Solar heating and cooling of a 40,000 square foot manufacturing building, sales offices and the solar computer control center/display room are described. Information on system description, test data, major problems and resolutions, performance, operation and maintenance manual, manufacturer's literature and as-built drawings are provided also. The solar system is composed of 6000 square feet of Sunworks double glazed flat plate collectors, external above ground storage subsystem, controls, ARKLA absorption chiller, heat recovery and a cooling tower.

None

1981-03-01T23:59:59.000Z

418

Biobriefcase electrostatic aerosol collector  

DOE Patents (OSTI)

A system for sampling air and collecting particles entrained in the air comprising a receiving surface, a liquid input that directs liquid to the receiving surface and produces a liquid surface, an air input that directs the air so that the air with particles entrained in the air impact the liquid surface, and an electrostatic contact connected to the liquid that imparts an electric charge to the liquid. The particles potentially including bioagents become captured in the liquid by the air with particles entrained in the air impacting the liquid surface. Collection efficiency is improved by the electrostatic contact electrically charging the liquid. The effects of impaction and adhesion due to electrically charging the liquid allows a unique combination in a particle capture medium that has a low fluid consumption rate while maintaining high efficiency.

Bell, Perry M. (Tracy, CA); Christian, Allen T. (Madison, WI); Bailey, Christopher G. (Pleasanton, CA); Willis, Ladona (Manteca, CA); Masquelier, Donald A. (Tracy, CA); Nasarabadi, Shanavaz L. (Livermore, CA)

2009-03-17T23:59:59.000Z

419

Photovoltaic-thermal collectors  

DOE Patents (OSTI)

A photovoltaic-thermal solar cell including a semiconductor body having antireflective top and bottom surfaces and coated on each said surface with a patterned electrode covering less than 10% of the surface area. A thermal-absorbing surface is spaced apart from the bottom surface of the semiconductor and a heat-exchange fluid is passed between the bottom surface and the heat-absorbing surface.

Cox, III, Charles H. (Carlisle, MA)

1984-04-24T23:59:59.000Z

420

Viscous sludge sample collector  

DOE Patents (OSTI)

A vertical core sample collection system for viscous sludge. A sample tube's upper end has a flange and is attached to a piston. The tube and piston are located in the upper end of a bore in a housing. The bore's lower end leads outside the housing and has an inwardly extending rim. Compressed gas, from a storage cylinder, is quickly introduced into the bore's upper end to rapidly accelerate the piston and tube down the bore. The lower end of the tube has a high sludge entering velocity to obtain a full-length sludge sample without disturbing strata detail. The tube's downward motion is stopped when its upper end flange impacts against the bore's lower end inwardly extending rim.

Beitel, George A [Richland, WA

1983-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Experimental study on roll-bond collector/evaporator with optimized-channel used in direct expansion solar assisted heat pump water heating system  

Science Journals Connector (OSTI)

Abstract In this investigation, a direct expansion solar assisted heat pump (DX-SAHP) water heating system using an optimized-channel roll-bond collector/evaporator was designed, fabricated and tested. Optimized fractal T-shape and honeycomb shaped channel patterns were adopted to improve the thermal performance of the roll-bond panel, which acts as both the evaporator for the heat pump system and the collector for solar thermal utilization. The performance of the studied water heating system using the south-faced, wall-mounted roll-bond panel with the new composite channel patterns was investigated experimentally. Results show that, under the experimental conditions, the roll-bond panel with optimized channel pattern shows better thermal properties, and the performance the DX-SAHP system is significantly enhanced by using the roll-bond panel with optimized channel pattern. Compared to the conventional parallel channel pattern, fractal T-shaped channel pattern enhanced COP of the system by 14.6%, and heating capacity by 17.3%. And the honeycomb shaped channel pattern further enhanced COP and heating capacity of the system by 5.9% and 6.2%.

Xiaolin Sun; Jingyi Wu; Yanjun Dai; Ruzhu Wang

2014-01-01T23:59:59.000Z

422

A study of the utility of heat collectors in reducing the response time of automatic fire sprinklers located in production modules of Building 707  

SciTech Connect

Several of the ten production Modules in Building 707 at the Department of Energy Rocky Flats Plant recently underwent an alteration which can adversely affect the performance of the installed automatic fire sprinkler systems. The Modules have an approximate floor to ceiling height of 17.5 ft. The alterations involved removing the drop ceilings in the Modules which had been at a height of 12 ft above the floor. The sprinkler systems were originally installed with the sprinkler heads located below the drop ceiling in accordance with the nationally recognized NFPA 13, Standard for the Installation of Automatic Sprinkler Systems. The ceiling removal affects the sprinkler`s response time and also violates NFPA 13. The scope of this study included evaluation of the feasibility of utilizing heat collectors to reduce the delays in sprinkler response created by the removal of the drop ceilings. The study also includes evaluation of substituting quick response sprinklers for the standard sprinklers currently in place, in combination with a heat collector.

Shanley, J.H. Jr.; Budnick, E.K. Jr. [Hughes Associates, Inc., Wheaton, MD (United States)

1990-01-01T23:59:59.000Z

423

Mathematical analysis of the influence of the chimney height and collector area on the performance of a roof top solar chimney  

Science Journals Connector (OSTI)

Abstract Determination of the roof top solar chimney behaviour during the day time is essential for the proper designing and sizing. This paper presents a mathematical model and analysis of an inclined type roof top solar chimney. The thermal energy and fluid flow processes were simulated mathematically based on the energy and mass balances. The model was converted to a MATLAB computer program and solved by iteration method. The analysis was carried out at various collector areas (15, 150, and 600 m2) and various chimney heights (5, 10, and 15 m). The model was validated by comparing the results with the experimental measurements. The developed mathematical model was able to predict the dynamic behaviour of the system. The results demonstrated that the performance of the system is highly influenced by the solar intensity. The system becomes functional for space ventilation when the solar intensity is higher than 400 W/m2 with a 15 m2 collector area and 5 m chimney height, under Malaysia and similar weather conditions. As the wind speed increases from 1.5 to 6 m/s, it contributes to reduce the system performance by 25% at solar intensity of 900 W/m2.

Hussain H. Al-Kayiem; Sreejaya K.V.; Syed Ihtsham Ul-Haq Gilani

2014-01-01T23:59:59.000Z

424

Measurements Versus Predictions for the Static and Dynamic Characteristics of a Four-pad Rocker-pivot, Tilting-pad Journal Bearing  

E-Print Network (OSTI)

Measured and predicted static and dynamic characteristics are provided for a four-pad, rocker-pivot, tilting-pad journal bearing in the load-on-pad and load-between-pad orientations. The bearing has the following characteristics: 4 pads, .57 pad...

Tschoepe, David 1987-

2012-08-16T23:59:59.000Z

425

Abstract--We propose a compact tip-reflection fiber-optic vibration sensing system that uses a lateral-offset tilted fiber  

E-Print Network (OSTI)

a lateral-offset tilted fiber grating (TFBG) as sensor head and a vertical-cavity surface-emitting laser the coupling of light from the forward propagating core mode to backward propagating cladding modes and reduces cladding mode resonances appear. Since the response of core mode to external perturbations (temperature

Wai, Ping-kong Alexander

426

Measured and predicted rotordynamic coefficients and static performance of a rocker-pivot, tilt pad bearing in load-on-pad and load-between-pad configurations  

E-Print Network (OSTI)

This thesis presents the static and dynamic performance data for a 5 pad tilting pad bearing in both the load-on-pad (LOP) and the load-between-pad (LBP) configurations over a variety of different loads and speeds. The bearing tested was an Orion...

Carter, Clint Ryan

2009-06-02T23:59:59.000Z

427

Tilt Meters Being Installed  

Science Journals Connector (OSTI)

...excep- tion the fundamental requirement that...interior- wall of boiler-room. This...the buildings safe for operation and providing...amperes for normal operation. A Laon tube...0.1, the fundamental REPORTS AND PAPERS...

428

Radiation Absorption and Optimization of Solar Photocatalytic Reactors for Environmental Applications  

Science Journals Connector (OSTI)

Ray tracing technique was coupled with the six-flux absorption scattering model (SFM) to analyze the complex radiation field in solar compound parabolic collectors (CPC) and tubular photoreactors. ... The SFM was applied to estimate the LVRPA in a flat plate (21), in annular reactors to model the photocatalytic degradation of phenylurea and triazine herbicides (12, 13), and in conjunction with ray tracing to model the photocatalytic mineralization of commercial herbicides (used in sugar cane crops) in a pilot-scale, solar, compound parabolic collector (CPC) reactor (22). ... horizontal coordinate, m ...

Jose Colina-Márquez; Fiderman Machuca-Martínez; Gianluca Li Puma

2010-06-09T23:59:59.000Z

429

Solar aided power generation of a 300 MW lignite fired power plant combined with line-focus parabolic trough collectors field  

Science Journals Connector (OSTI)

Abstract Nowadays, conventional coal or gas fired power plants are the dominant way to generate electricity in the world. In recent years there is a growth in the field of renewable energy sources in order to avoid the threat of climate change from fossil fuel combustion. Solar energy, as an environmental friendly energy source, may be the answer to the reduction of global CO2 emissions. This paper presents the concept of Solar Aided Power Generation (SAPG), a combination of renewable and conventional energy sources technologies. The operation of the 300 MW lignite fired power plant of Ptolemais integrated with a solar field of parabolic trough collectors was simulated using TRNSYS software in both power boosting and fuel saving modes. The power plant performance, power output variation, fuel consumption and CO2 emissions were calculated. Furthermore, an economic analysis was carried out for both power boosting and fuel saving modes of operation and optimum solar contribution was estimated.

G.C. Bakos; Ch. Tsechelidou

2013-01-01T23:59:59.000Z

430

Evaluation of Steelhead Kelt Passage into the Bonneville Dam Second Powerhouse Corner Collector Prior to the Juvenile Migration Seasons, 2007 and 2008  

SciTech Connect

This report documents the results of a steelhead kelt passage study conducted by the PNNL for the U.S. Army Corps of Engineers at Bonneville Dam in early spring 2007 and 2008. At the Second Powerhouse, a surface flow outlet called the corner collector (B2CC) may be an effective non-turbine passage route for steelhead kelt moving downstream in early spring before the main juvenile emigration season. The goal of this project was to inform management decisions regarding B2CC operations by estimating the number of kelt using the B2CC for downstream passage at Bonneville Dam prior to the juvenile spring migration season. We performed a hydroacoustic study from March 2 to April 10, 2007 and from March 13 to April 15, 2008.

Weiland, Mark A.; Kim, Jina; Nagy, William T.; Johnson, Gary E.

2009-09-01T23:59:59.000Z

431

Study of corrosion in multimetallic systems. Task 2 of solar collector studies for solar heating and cooling applications. Final technical progress report  

SciTech Connect

Corrosion measurements were made on candidate alloys of construction for non-concentrating solar collectors under simulated conditions of collector operation. Materials evaluated were aluminum alloys 1100, 3003, and 6061, copper alloy 122, Type 444 stainless steel, and 1018 plain carbon steel. The solutions used were equivolume mixtures of ethylene glycol and water, and propylene glycol and water. They were used without corrosion inhibitors but with addition of chloride, sulfate, and bicarbonate ions. The influences of dissolved oxygen, solution flow velocity, and heat transfer were evaluated. Corrosion morphologies investigated were general attack, pitting, crevice corrosion, and galvanic corrosion. Experimental results indicated that aluminum alloys can experience severe pitting and crevice corrosion at chloride concentrations approaching 50 ppM. The corrosion rate of copper exceeded about 100 ..mu..m/yr in ethylene glycol solutions and about 80 ..mu..m/yr in propylene glycol solutions. Crevice corrosion was not observed for copper, but severe galvanic corrosion occurred when it was coupled to T444 stainless steel. T444 steel corroded at rates of less than 1 ..mu..m/yr under all exposure conditions. During circulation at 100 C in the presence of air, ethylene glycol solutions acidified because of degradation of the glycol. The initial pH of propylene glycol solutions was already low, about 4.5. The inherent corrosivity of propylene glycol was somewhat less than that of ethylene glycol, although this difference was usually less than a factor of two in measured corrosion rates. It was concluded that he corrosion rates of aluminum alloys and copper were prohibitively high in uninhibited glycol solutions, and that corrosion inhibitors are definitely necessary in operating systems.

Diegle, R B

1980-04-11T23:59:59.000Z

432

HOUSING Extension Bulletin E-1761 (new) March,1984 COOPERATIVE EXTENSION SERVICE MICHIGAN STATE UNIVERSITY  

E-Print Network (OSTI)

Available The energy available on a solar collector surface de- pends on the time of day,the time of year latitude. The different curves represent various collector tilt angles measured from the horizontal of the collector so the sun's rays are perpendicular to the collector at solar noon. Reviewers Arlen Benteman

433

NREL GIS Data: Alaska Low Resolution Concentrating Solar Power Resource |  

Open Energy Info (EERE)

Alaska Low Resolution Concentrating Solar Power Resource Alaska Low Resolution Concentrating Solar Power Resource Dataset Summary Description Abstract: Monthly and annual average solar resource potential for Alaska. Purpose: Provide information on the solar resource potential for Alaska. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented due south at an angle from horizontal equal to the latitude of the collector location. Supplemental_Information: This data provides monthly average and annual average daily total solar resource averaged over surface cells of approximatley 40 km by 40 km in size. This data was developed from the Climatological Solar Radiation (CSR) Model. The CSR model was developed by the National Renewable Energy Laboratory for the U.S. Department of Energy. Specific information about this model can be found in Maxwell, George and Wilcox (1998) and George and Maxwell (1999). This model uses information on cloud cover, atmostpheric water vapor and trace gases, and the amount of aerosols in the atmosphere to calculate the monthly average daily total insolation (sun and sky) falling on a horizontal surface. The cloud cover data used as input to the CSR model are an 7-year histogram (1985-1991) of monthly average cloud fraction provided for grid cells of approximately 40km x 40km in size. Thus, the spatial resolution of the CSR model output is defined by this database. The data are obtained from the National Climatic Data Center in Ashville, North Carolina, and were developed from the U.S. Air Force Real Time Nephanalysis (RTNEPH) program. Atmospheric water vapor, trace gases, and aerosols are derived from a variety of sources. The procedures for converting the collector at latitude tilt are described in Marion and Wilcox (1994). Where possible, existing ground measurement stations are used to validate the data. Nevertheless, there is uncertainty associated with the meterological input to the model, since some of the input parameters are not avalible at a 40km resolution. As a result, it is believed that the modeled values are accurate to approximately 10% of a true measured value within the grid cell. Due to terrain effects and other micoclimate influences, the local cloud cover can vary significantly even within a single grid cell. Furthermore, the uncertainty of the modeled estimates increase with distance from reliable measurement sources and with the complexity of the terrain. Units are in watt hours.

434

NREL GIS Data: Alaska Low Resolution Photovoltaic Solar Resource | OpenEI  

Open Energy Info (EERE)

8 8 Varnish cache server Browse Upload data GDR 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2142278078 Varnish cache server NREL GIS Data: Alaska Low Resolution Photovoltaic Solar Resource Dataset Summary Description Abstract: Monthly and annual average solar resource potential for Alaska. Purpose: Provide information on the solar resource potential for Alaska. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented due south at an angle from horizontal equal to the latitude of the collector location. Supplemental_Information: This data provides monthly average and annual average daily total solar resource averaged over surface cells of approximatley 40 km by 40 km in size. This data was developed from the Climatological Solar Radiation (CSR) Model. The CSR model was developed by the National Renewable Energy Laboratory for the U.S. Department of Energy. Specific information about this model can be found in Maxwell, George and Wilcox (1998) and George and Maxwell (1999). This model uses information on cloud cover, atmostpheric water vapor and trace gases, and the amount of aerosols in the atmosphere to calculate the monthly average daily total insolation (sun and sky) falling on a horizontal surface. The cloud cover data used as input to the CSR model are an 7-year histogram (1985-1991) of monthly average cloud fraction provided for grid cells of approximately 40km x 40km in size. Thus, the spatial resolution of the CSR model output is defined by this database. The data are obtained from the National Climatic Data Center in Ashville, North Carolina, and were developed from the U.S. Air Force Real Time Nephanalysis (RTNEPH) program. Atmospheric water vapor, trace gases, and aerosols are derived from a variety of sources. The procedures for converting the collector at latitude tilt are described in Marion and Wilcox (1994). Where possible, existing ground measurement stations are used to validate the data. Nevertheless, there is uncertainty associated with the meterological input to the model, since some of the input parameters are not avalible at a 40km resolution. As a result, it is believed that the modeled values are accurate to approximately 10% of a true measured value within the grid cell. Due to terrain effects and other micoclimate influences, the local cloud cover can vary significantly even within a single grid cell. Furthermore, the uncertainty of the modeled estimates increase with distance from reliable measurement sources and with the complexity of the terrain.

435

NREL GIS Data: Hawaii Low Resolution Concentrating Solar Power Resource |  

Open Energy Info (EERE)

Low Resolution Concentrating Solar Power Resource Low Resolution Concentrating Solar Power Resource Dataset Summary Description Abstract: Monthly and annual average solar resource potential for Hawaii. Purpose: Provide information on the solar resource potential for Hawaii. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented due south at an angle from horizontal equal to the latitude of the collector location. Supplemental_Information: This data provides monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. This data was developed from the Climatological Solar Radiation (CSR) Model. The CSR model was developed by the National Renewable Energy Laboratory for the U.S. Department of Energy. Specific information about this model can be found in Maxwell, George and Wilcox (1998) and George and Maxwell (1999). This model uses information on cloud cover, atmostpheric water vapor and trace gases, and the amount of aerosols in the atmosphere to calculate the monthly average daily total insolation (sun and sky) falling on a horizontal surface. The cloud cover data used as input to the CSR model are an 7-year histogram (1985-1991) of monthly average cloud fraction provided for grid cells of approximately 40km x 40km in size. Thus, the spatial resolution of the CSR model output is defined by this database. The data are obtained from the National Climatic Data Center in Ashville, North Carolina, and were developed from the U.S. Air Force Real Time Nephanalysis (RTNEPH) program. Atmospheric water vapor, trace gases, and aerosols are derived from a variety of sources. The procedures for converting the collector at latitude tilt are described in Marion and Wilcox (1994). Where possible, existing ground measurement stations are used to validate the data. Nevertheless, there is uncertainty associated with the meterological input to the model, since some of the input parameters are not avalible at a 40km resolution. As a result, it is believed that the modeled values are accurate to approximately 10% of a true measured value within the grid cell. Due to terrain effects and other micoclimate influences, the local cloud cover can vary significantly even within a single grid cell. Furthermore, the uncertainty of the modeled estimates increase with distance from reliable measurement sources and with the complexity of the terrain.

436

Solar space heating installed at Kansas City, Kansas. Final report  

SciTech Connect

The solar energy system was constructed with the new 48,800 square feet warehouse to heat the warehouse area of about 39,000 square feet while the auxiliary energy system heats the office area of about 9800 square feet. The building is divided into 20 equal units, and each has its own solar system. The modular design permits the flexibility of combining multiple units to form offices or warehouses of various size floor areas as required by a tenant. Each unit has 20 collectors which are mounted in a single row. The collectors, manufactured by Solaron Corporation, are double glazed flat plate collectors with a gross area of 7800 ft/sup 2/. Air is heated either through the collectors or by the electric resistance duct coils. No freeze protection or storage is required for this system. Extracts from the site files, specifications, drawings, installation, operation and maintenance instructions are included.

Not Available

1981-05-01T23:59:59.000Z

437

Battery paste compositions and electrochemical cells for use therewith  

SciTech Connect

An improved battery paste composition and a lead-acid electrochemical cell which incorporates the composition are disclosed. The cell includes a positive current collector and a negative current collector which are each coated with a paste containing one or more lead-containing compositions and a paste vehicle to form a positive plate and a negative plate. An absorbent electrolyte-containing separator member may also be positioned between the positive and negative plates. The paste on the positive current collector, the negative current collector, or both further includes a special additive consisting of polyvinyl sulfonic acid or salts thereof which provides many benefits including improved battery cycle life, increased charge capacity, and enhanced overall stability. The additive also makes the pastes smoother and more adhesive, thereby improving the paste application process. The paste compositions of interest may be used in conventional flat-plate cells or in spirally wound batteries with equal effectiveness. 2 figs.

Olson, J.B.

1999-02-16T23:59:59.000Z

438

Investigation into the failure cause of a double-acting, leading-edge-groove, tilting-pad thrust bearing. Final report, Feb-Aug 90  

SciTech Connect

This report describes the results of bench tests simulating operation and failure of a thrust bearing used in a gas turbine engine compressor development test rig. The bearing was a double acting, tilting pad with offset pivot, leading edge groove configuration using an AMS 4928 titanium collar and C18200 copper-chrome alloy pads with a No. 2 babbitt face. The bench tests successfully simulated the bearing failure and demonstrated a materials incompatibility. This was supported by visual examination, scanning electron microscopy and X-ray energy spectroscopy. A comparison of the bench test results to the compressor rig bearing failure is provided to support the report conclusions.

Peterson, B.K.

1990-10-01T23:59:59.000Z

439

Experimental frequency-dependent rotordynamic coefficients for a load-on-pad, high-speed, flexible-pivot tilting-pad bearing  

E-Print Network (OSTI)

others. Fig. 1 depicts a schematic of a conventional TP bearing with four pads and the basic geometric characteristics. R+Cp R+Cb R omega beta chi Bottom Pad Detail Geometric Definitions: Pad Preload=1-Cb/Cp Pad Offset=betachi Pad Leading edge... maximum rotordynamic stability [1]. TP bearings differ from fixed geometry journal bearings in that the pads are able to tilt freely about a pivot. The pivot configuration can be spherical, as illustrated in Fig. 1, rocker type, among others...

Rodriguez Colmenares, Luis Emigdio

2004-09-30T23:59:59.000Z

440

Precise and accurate determination of boron isotope ratios by multiple collector ICP-MS: origin of boron in the Ngawha geothermal system, New Zealand  

Science Journals Connector (OSTI)

A new technique has been developed for the measurement of boron isotope ratios in fluids using a double focusing multiple collector inductively coupled plasma (ICP) mass spectrometer. Sample introduction using a direct injection nebuliser was found to eliminate memory problems that are common where spray chambers are involved. The 4–9% mass bias can be corrected for by bracketing sample measurements with standards. As matrices were found to affect the mass bias all samples must be purified and that sample and standard solutions must be similar. A new purification technique was developed that yields adequately purified samples. Using this technique, it is possible to make rapid measurements (4 min) from samples containing 250 ng B to a precision of ±0.2‰. This analytical technique has been applied to the Ngawha geothermal system in New Zealand in an attempt to determine the source of B in geothermal fluids where the B concentrations can exceed 100 mmol/l. The ?11B values range between ?3.1‰ and ?3.9‰ indicating that no seawater sources are involved and that the elevated B concentrations can only be accounted for by low water/rock ratios with the B being derived from basement greywacke/argillite. The similarity of B isotope ratios for hydrothermal fluids that have been diluted and cooled with groundwaters indicates that isotope fractionation due to adsorption is unlikely to occur in cool geothermal fluids (<40 °C).

J.K. Aggarwal; D. Sheppard; K. Mezger; E. Pernicka

2003-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Performance evaluation of an active solar cooling system utilizing low cost plastic collectors and an evaporatively-cooled absorption chiller. Final report  

SciTech Connect

During the summer of 1982, air conditioning in Solar House III at Colorado State University was provided by an evaporatively-cooled absorption chiller. The single-effect lithium bromide chiller provided by Arkla Industries is an experimental three-ton unit from which heat is rejected by direct evaporative cooling of the condenser and absorber walls, thereby eliminating the need for a separate cooling tower. Domestic hot water was also provided by use of a double-walled heat exchanger and 300-l (80-gal) hot water tank. For solar heat supply to the cooling system, plastic thin film collectors developed by Brookhaven National Laboratory were installed on the roof of Solar House III. Failure to withstand stagnation temperatures forced replacement of solar energy with an electric heat source. Objectives of the project were: (1) evaluation of system performance over the course of one cooling season in Fort collins, Colorado; (2) optimization of system operation and control; (3) development of a TRNSYS compatible model of the chiller; and (4) determination of cooling system performance in several US climates by use of the model.

Lof, G.O.G.; Westhoff, M.A.; Karaki, S.

1984-02-01T23:59:59.000Z

442

The Effect of Magnetic Field Tilt and Divergence on the Mass Flux and Flow Speed in a Line-Driven Stellar Wind  

E-Print Network (OSTI)

We carry out an extended analytic study of how the tilt and faster-than-radial expansion from a magnetic field affect the mass flux and flow speed of a line-driven stellar wind. A key motivation is to reconcile results of numerical MHD simulations with previous analyses that had predicted non-spherical expansion would lead to a strong speed enhancement. By including finite-disk correction effects, a dynamically more consistent form for the non-spherical expansion, and a moderate value of the line-driving power index $\\alpha$, we infer more modest speed enhancements that are in good quantitative agreement with MHD simulations, and also are more consistent with observational results. Our analysis also explains simulation results that show the latitudinal variation of the surface mass flux scales with the square of the cosine of the local tilt angle between the magnetic field and the radial direction. Finally, we present a perturbation analysis of the effects of a finite gas pressure on the wind mass loss rate and flow speed in both spherical and magnetic wind models, showing that these scale with the ratio of the sound speed to surface escape speed, $a/v_{esc}$, and are typically 10-20% compared to an idealized, zero-gas-pressure model.

Stan Owocki; Asif ud-Doula

2003-10-07T23:59:59.000Z

443

Experimental energy and exergy analysis of a double-flow solar air heater having different obstacles on absorber plates  

Science Journals Connector (OSTI)

This paper presents an experimental energy and exergy analysis for a novel flat plate solar air heater (SAH) with several obstacles and without obstacles. For increasing the available heat-transfer area may be achieved if air is flowing simultaneously and separately over and under the different obstacle absorbing plates, instead of only flowing either over or under the different obstacle absorbing plates, leading to improved collector efficiency. The measured parameters were the inlet and outlet temperatures, the absorbing plate temperatures, the ambient temperature, and the solar radiation. Further, the measurements were performed at different values of mass flow rate of air and different levels of absorbing plates in flow channel duct. After the analysis of the results, the optimal value of efficiency is middle level of absorbing plate in flow channel duct for all operating conditions and the double-flow collector supplied with obstacles appears significantly better than that without obstacles. At the end of this study, the exergy relations are delivered for different SAHs. The results show that the largest irreversibility is occurring at the flat plate (without obstacles) collector in which collector efficiency is smallest.

Hikmet Esen

2008-01-01T23:59:59.000Z

444

Bad bag detection systems installed on the COHPAC (Compact Hybrid Particulate Collector) at Alabama Power, E.C. Gaston Unit No.3  

SciTech Connect

In December of 1996, Alabama Power Company, a subsidiary of the Southern Company, began operating a baghouse in conjunction with an existing hot-side precipitator on the cold side of the air heaters. The concept combining an electrostatic precipitator and a baghouse is termed a COHPAC (Compact Hybrid Particulate Collector), an EPRI technology. The baghouse is installed on Unit No.3 which is a 280 Mwe pulverized coal fired unit. Unit No.3 shares a common stack with Unit No.4, so the baghouse treats 50% of the total stack flow. The installation has resulted in the ability of both boilers to operate without costly boiler load reductions, which were quite common prior to the installation of the COHPAC system because of stack capacity. To date, after nearly three years of operation the COHPAC system has meet and exceeded all performance expectations. The installation has consistently provided low outlet emissions (<0.01 lb/Mbtu) and low opacity levels. To date, there have not been any known bag failures and maintenance has been minimal. Testing has shown bag life to be finite but no data has been compiled on this type system showing the operating window that would ensure optimal performance. Mullen Burst tests have shown degradation in bag strength, which indicates that this degradation at some point could result in premature failure of the bags. The COHPAC system installed at E.G., Gaston includes over 2,000 bags corresponding to roughly 57,500 ft{sup 2} of collecting surface area. Current methods of finding damaged bags are quite laborious and time intensive. A system to monitor performance and locating damaged bags will be presented. Associated performance and overall historical operating data on Unit No.3 will also be presented.

Berry, M.S.; Harrison, W.; Corina, B.; Wilson, R.; Harrington, J.

1999-07-01T23:59:59.000Z

445

Compression and acceleration of electron bunches to high energies in the interference field of intense laser pulses with tilted amplitude fronts: concept and modelling  

SciTech Connect

A new concept of accelerating electrons by laser radiation is proposed, namely, direct acceleration by a laser field under the conditions of interference of several relativistic-intensity laser pulses with amplitude fronts tilted by the angle 45 Degree-Sign with respect to the phase fronts. Due to such interference the traps moving with the speed of light arise that capture the electrons, produced in the process of ionisation of low-density gas by the same laser radiation. The modelling on the basis of solving the relativistic Newton equation with the appropriate Lorenz force shows that these traps, moving in space, successively collect electrons from the target, compress the resulting electron ensemble in all directions up to the dimensions smaller than the wavelength of the laser radiation and accelerate it up to the energies of the order of a few GeV per electron. (extreme light fields and their applications)

Korobkin, V V; Romanovsky, Mikhail Yu; Trofimov, V A; Shiryaev, O B [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2013-03-31T23:59:59.000Z

446

Tilting of the CuO6 octahedra in La1.83-xEu0.17SrxCuO4 as seen by Eu151 Mössbauer spectroscopy  

Science Journals Connector (OSTI)

Eu151 Mössbauer studies of La1.83-xEu0.17SrxCuO4 for 0<~x<~0.26 exhibit a quadrupole interaction at the Eu site whose magnitude eQVzz strongly depends on both the Sr content x and the temperature T. For a fixed temperature, a linear relationship is obtained between the quadrupole interaction and the averaged CuO6 octahedra tilting angle determined from diffraction studies. The unusually large temperature dependence of eQVzz strongly indicates a temperature dependence of the local structure. In contrast to recent studies of the local structure La2CuO4-type superconductors by means of x-ray-absorption and neutron-scattering techniques, our data give strong evidence that the local octahedra tilting in La1.83-xEu0.17SrxCuO4 corresponds well to the average tilting obtained by diffraction techniques.

C. Friedrich; B. Büchner; M. M. Abd-Elmeguid; H. Micklitz

1996-07-01T23:59:59.000Z

447

Solar Thermal Collector in Facades:.  

E-Print Network (OSTI)

??A venetian blind, which can be located in front or in between the façade panes, is proposed to do the task of a shading system… (more)

Cruz Lopez, P.B.

2011-01-01T23:59:59.000Z

448

Friction Factor Measurement, Analysis, and Modeling for Flat-Plates with 12.15 mm Diameter Hole-Pattern, Tested with Air at Different Clearances, Inlet Pressures, and Pressure Ratios  

E-Print Network (OSTI)

and 2 (hd = 2.9 mm, Cpl = 0.254 mm, Pin = 84 bar, Re= 32500 (maximum)) .................................................................. 76 Figure 50. Dynamic pressure at locations 3 and 4 (hd = 2.9 mm, Cpl = 0.254 mm, Pin = 84 bar, Re= 32500...)) .................................................................................................... 79 Figure 52. Dynamic pressure looked separately at location 1 and 2 ................................ 80 Figure 53. Dynamic pressure looked separately at location 3 and 4 ................................ 81 Figure 54. Dynamic pressure data (hd = 0...

Deva Asirvatham, Thanesh

2011-02-22T23:59:59.000Z

449

Solar water heaters | Open Energy Information  

Open Energy Info (EERE)

heaters heaters Jump to: navigation, search (The following text is derived from the United States Department of Energy's description of Solar Water Heating technology.)[1] Solar Water Heater One of the most cost-effective ways to include renewable technologies into a building is by incorporating solar hot water. A typical residential solar water-heating system reduces the need for conventional water heating by about two-thirds. It minimizes the expense of electricity or fossil fuel to heat the water and reduces the associated environmental impacts. Solar Water Heating for Buildings Most solar water-heating systems for buildings have two main parts: (1) a solar collector and (2) a storage tank. The most common collector used in solar hot water systems is the flat-plate collector. Solar water heaters use the sun to heat either water

450

Solar project description for Saddle Hill Trust: Lot 77, single family residence, Medway, Massachusetts  

SciTech Connect

A solar energy system for preheating domestic hot water for a single-family residence in Massachusetts is described. The system consists of four flat plate air-based collectors with a gross area of 77 square feet, an air-to-water heat exchanger, and a 120-gallon preheat tank for storage. Preheated domestic water is supplied from the preheat tank to a cnventional gas-fired 40-gallon domestic hot water tank which supplies the residential hot water demand. The original cost estimate for provisioning and installation of the solar system are given. Four modes of operation are described: collector-to-preheat, preheat-to-domestic hot water, night or cloudy collector condition, and overheat protection. The system performance evaluation instrumentation for the National Solar Data Network is described. (LEW)

Moore, D.

1981-11-06T23:59:59.000Z

451

An investigation of a residential solar system coupled to a radiant panel ceiling  

SciTech Connect

An experimental study of a solar-radiant heating system was performed at Iowa State University's Energy Research House (ERH). The ERH was constructed with copper tubes embedded in the plaster ceilings, thus providing a unique radiant heating system. In addition, 24 water-glycol, flat-plate solar collectors were mounted on the south side of the residence. The present study uses the solar collectors to heat a storage tank via a submerged copper tube oil. Hot water from the storage tank is then circulated through a heat exchanger, which heats the water flowing through the radiant ceiling. This paper contains a description of the solar-radiant system and an interpretation of the data that were measured during a series of transient experiments. In addition, the performance of the flat-plate solar collectors and the water storage tank were evaluated. The characteristics of a solar-to-radiant heat exchanger were also investigated. The thermal behavior of the radiant ceiling and the room enclosures were observed, and the heat transfer from the ceiling by radiation and convection was estimated. The overall heating system was also evaluated using the thermal performances of the individual components. The results of this study verify that it is feasible to use a solar system coupled to a low-temperature radiant-panel heating system for space heating. A sample performance evaluation is also presented.

Zhang, Z.; Pate, M.; Nelson, R.

1988-08-01T23:59:59.000Z

452

Solar energy system performance evaluation, July 1979 through June 1980  

SciTech Connect

The Loudoun County site is the Charles S. Monroe Vocational Technical School in Leesburg, Virginia. The active solar energy system is designed to supply 26% of the domestic hot water demand. It is equipped with 1225 square feet of double glazed flat-plate collectors manufactured by Southwest Enertech, a 2056 gallon liquid storage tank located in the school's mechanical room, and a backup electric immersion heater, 2 stage, 20 kW per stage. The system performance for the period July 1979 through June 1980 is presented, and the meteorological conditions are included. (WHK)

Missal, D.

1980-01-01T23:59:59.000Z

453

Photobioreactor Design for Commercial Biofuel Production from Microalgae  

Science Journals Connector (OSTI)

However, reactor area does not directly contribute to oil yield when light is collected externally from the site of algal cultivation, which some authors have advocated. ... Zijffers et al. employed the light guide technology in a flat-plate reactor known as the Green Solar Collector. ... The orientation was studied first resulting east/west the most favorable because the total solar radiation intercepted was max., increasing 5% with regard to horizontal placement, and the exposure resulted to be the most homogeneous over the year. ...

Aditya M. Kunjapur; R. Bruce Eldridge

2010-03-23T23:59:59.000Z

454

LANGEVIN DYNAMICS OF THE TWO STAGE MELTING TRANSITION OF VORTEX MATTER IN Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} IN THE PRESENCE OF STRAIGHT AND OF TILTED COLUMNAR DEFECTS  

SciTech Connect

In this paper we use London Langevin molecular dynamics simulations to investigate the vortex matter melting transition in the highly anisotropic high-temperature superconductor material Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}#14; in the presence of low concentration of columnar defects (CDs). We reproduce with further details our previous results obtained by using Multilevel Monte Carlo simulations that showed that the melting of the nanocrystalline vortex matter occurs in two stages: a first stage melting into nanoliquid vortex matter and a second stage delocalization transition into a homogeneous liquid. Furthermore, we report on new dynamical measurements in the presence of a current that identifies clearly the irreversibility line and the second stage delocalization transition. In addition to CDs aligned along the c-axis we also simulate the case of tilted CDs which are aligned at an angle with respect to the applied magnetic field. Results for CDs tilted by 45{degree} with respect to c-axis show that the locations of the melting and delocalization transitions are not affected by the tilt when the ratio of flux lines to CDs remains constant. On the other hand we argue that some dynamical properties and in particular the position of the irreversibility line should be affected.

GOLDSCHMIDT, YADIN Y.; LIU, Jin-Tao

2007-08-07T23:59:59.000Z

455

OTilt | Open Energy Information  

Open Energy Info (EERE)

OTilt OTilt Jump to: navigation, search Tool Summary LAUNCH TOOL Name: oTilt Agency/Company /Organization: Naveed ur Rehman Sector: Energy Focus Area: - Solar PV Resource Type: Software/modeling tools User Interface: Website Complexity/Ease of Use: Simple Website: www.otilt.com Web Application Link: www.otilt.com Cost: Free References: DEVELOPMENT OF SIMULATION TOOL FOR FINDING OPTIMUM TILT ANGLES FOR SOLAR COLLECTORS[1] Logo: oTilt oTilt is an optimum tilt angle calculator for solar collectors. Details oTilt is an online tool for quickly determining the optimum tilt angles for solar collectors. Site can be located in an integrated Google map, searching it using keywords (e.g. Central Park, New York) or by directly entering latitude and longitude. oTilt determines the optimum monthly,

456

Solar: monthly and annual average global horizontal (GHI) GIS data at 40km  

Open Energy Info (EERE)

China from NREL China from NREL Dataset Summary Description (Abstract): Monthly average solar resource for horizontal flat-plate collectors for China. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented horizontally. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The data were developed from NREL's Climatological Solar Radiation (CSR) Model. This model uses information on cloud cover, atmospheric water vapor and trace gases, and the amount of aerosols in the atmosphere to calculate the monthly average daily total insolation (sun and sky) falling on a horizontal surface. Existing ground measurement stations are used to validate the data where possible. The modeled values are accurate to approximately 10% of a true measured value within the grid cell due to the uncertainties associated with meteorological input to the model. The local cloud cover can vary significantly even within a single grid cell as a result of terrain effects and other microclimate influences. Furthermore, the uncertainty of the modeled estimates increase with distance from reliable measurement sources and with the complexity of the terrain.

457

Solar: monthly and annual average global horizontal (GHI) GIS data at 40km  

Open Energy Info (EERE)

Mexico, Central America, and the Caribbean Islands from NREL Mexico, Central America, and the Caribbean Islands from NREL Dataset Summary Description (Abstract): Monthly Average Solar Resource for horizontal flat-plate collectors, for Mexico, Central America, and the Caribbean Islands. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented horizontally. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The data were developed from NREL's Climatological Solar Radiation (CSR) Model. This model uses information on cloud cover, atmospheric water vapor and trace gases, and the amount of aerosols in the atmosphere to calculate the monthly average daily total insolation (sun and sky) falling on a horizontal surface. Existing ground measurement stations are used to validate the data where possible. The modeled values are accurate to approximately 10% of a true measured value within the grid cell due to the uncertainties associated with meteorological input to the model. The local cloud cover can vary significantly even within a single grid cell as a result of terrain effects and other microclimate

458

Solar: annual average global horizontal (GHI) GIS data at 10km resolution  

Open Energy Info (EERE)

global horizontal (GHI) GIS data at 10km resolution global horizontal (GHI) GIS data at 10km resolution for Cuba from SUNY Dataset Summary Description (Abstract): Monthly Average Solar Resource for horizontal flat-plate solar collectors for Cuba (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a horizontal flat-plate solar collector, such as a Photovoltaic (PV) solar panel. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 10 km by 10 km in size. The solar resource value is represented as kilowatt-hours per square meter per day for each month. The data were developed from the State University of New York's (SUNY) GOES satellite solar model. This model uses information on hourly satellite observed visible irradiance, atmospheric water vapor and trace gases, and the amount of aerosols in the atmosphere to calculate the monthly average daily total of the normal or beam insolation falling on a tracking concentrator pointed

459

Solar: monthly and annual average global horizontal (GHI) GIS data at 40km  

Open Energy Info (EERE)

Ethiopia from NREL Ethiopia from NREL Dataset Summary Description (Abstract): Monthly average solar resource for horizontal flat-plate collectors for Ethiopia. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented horizontally. (Supplemental Information): These data provide monthly average and annual average daily total solar resource averaged over surface cells of approximately 40 km by 40 km in size. The solar resource value is represented as watt-hours per square meter per day for each month. The data were developed from NREL's Climatological Solar Radiation (CSR) Model. This model uses information on cloud cover, atmospheric water vapor and trace gases, and the amount of aerosols in the atmosphere to calculate the monthly average daily total insolation (sun and sky) falling on a horizontal surface. Existing ground measurement stations are used to validate the data where possible. The modeled values are accurate to approximately 10% of a true measured value within the grid cell due to the uncertainties associated with meteorological input to the

460

PROCEEDINGS OF THE SOLAR 99 CONFERENCE  

NLE Websites -- All DOE Office Websites (Extended Search)

SOLAR 99 CONFERENCE SOLAR 99 CONFERENCE Including Proceedings of ASES Annual Conference Proceedings of 24 th National Passive Solar Conference Portland, Maine June 12 -16, 1999 Editors: R. Campbell-Howe B. Wilkins-Crowder American Solar Energy Society American Institute of Architects Committee on the Environment Printed on recycled paper HIGH-RESOLUTION MAPS OF SOLAR COLLECTOR PERFORMANCE USING A CLIMATOLOGICAL SOLAR RADIATION MODEL Raymond L. George National Renewable Energy Laboratory 1617 Cole Blvd. Golden, CO 80401 e-mail: ray george@nrel.gov ABSTRACT This paper will present a new methodology for producing estimates of the monthly and annual average performance of different types of flat-plate and concentrating solar collectors. The estimates are made on a uniform spatial grid

Note: This page contains sample records for the topic "flat-plate collectors tilted" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Solar energy system performance evaluation. Seasonal report for Fern Lansing, Lansing, Michigan  

SciTech Connect

The Solar Energy System was designed by Fern Engineering Company, Bourne, Massachusetts to provide space heating and domestic hot water preheating for a 1300 square foot single-family residence located in Lansing, Michigan. The Solar Energy System consists of a 278 square foot flat-plate air collector subsystem, a three 120-gallon tank storage subsystem, a 40 gallon domestic hot water tank subsystem, a liquid/air heat exchanger, an energy transport module, pumps, controls and heat transfer medium lines. Natural gas provides the auxiliary energy for the space heating (100,000 Btu/h) and hot water (70,000 Btu/h) subsystems. The system is shown schematically and has five modes of operation. Typical system operation, system operating sequence, performance assessment, system performance, subsystems performance (collector array, storage, hot water, space heating), operating energy, energy savings, and maintenance are discussed. A brief summary of all pertinent parameters is presented.

Not Available

1980-06-01T23:59:59.000Z

462

Thermal and economical analysis of a central solar heating system with underground seasonal storage in Turkey  

Science Journals Connector (OSTI)

Thermal performance and economic feasibility of two types of central solar heating system with seasonal storage under four climatically different Turkey locations are investigated. The effects of storage volume and collector area on the thermal performance and cost are studied for three load sizes. The simulation model of the system consisting of flat plate solar collectors, a heat pump, under ground storage tank and heating load based on a finite element analysis and finite element code ANSYS™ is chosen as a convenient tool. In this study, the lowest solar fraction value for Trabzon (41°N) and the highest solar fraction value for Adana (37°N) are obtained. Based on the economic analysis, the payback period of system is found to be about 25–35 years for Turkey.

A. Ucar; M. Inalli

2005-01-01T23:59:59.000Z

463

Lawrence Berkeley Laboratory, Berkeley, California solar energy system performance evaluation, July 1980-June 1981  

SciTech Connect

The Lawrence Berkeley Laboratory site is an office building in California with an active solar energy system designed to supply from 23 to 33% of the space heating load and part of the hot water load. The solar heating system is equipped with 1428 square feet of flat-plate collectors, a 2000-gallon water storage tank, and two gas-fired boilers to supply auxiliary heat for both space heating and domestic hot water. Poor performance is reported, with the solar fraction being only 4%. Also given are the solar savings ratio, conventional fuel savings, system performance factor, and the coefficient of performance. The performance data are given for the collector, storage, solar water heating and solar space heating subsystems as well as the total system. Typical system operation and solar energy utilization are briefly described. The system design, performance evaluation techniques, weather data, and sensor technology are presented. (LEW)

Wetzel, P.E.

1981-01-01T23:59:59.000Z

464

Application of solar thermal energy to buildings and industry  

SciTech Connect

Flat plate collectors and evacuated tube collectors are described, as are parabolic troughs, Fresnel lenses, and compound parabolic concentrators. Use of solar energy for domestic hot water and for space heating and cooling are discussed. Some useful references and methods of system design and sizing are given. This includes mention of the importance of economic analysis. The suitability of solar energy for industrial use is discussed, and solar ponds, point-focus receivers and central receivers are briefly described. The use of solar energy for process hot water, drying and dehydration, and process steam are examined, industrial process heat field tests by the Department of Energy are discussed, and a solar total energy system in Shenandoah, GA is briefly described. (LEW)

Kutscher, C. F.

1981-05-01T23:59:59.000Z

465

Solar-powered/fuel-assisted Rankine-cycle power and cooling system: Simulation method and seasonal performance  

SciTech Connect

The subject of this analysis is a solar cooling system based on a novel hybrid steam Rankine cycle. Steam is generated by the use of solar energy collected at about 100/sup 0/C, and it is then superheated to about 600/sup 0/C in a fossil-fuel-fired superheater. The addition of about 20-26 percent of fuel doubles the power cycle's efficiencyas compared to organic Rankine cycles operating at similar collector temperatures. A comprehensive computer program was developed to analyze the operation and performance of the entire power/cooling system. Transient simulation was performed on an hourly basis over a cooling season in two representative climatic regions (Washington, D.C. and Phoenix, Ariz.). One of the conclusions is that the seasonal system COP is 0.82 for the design configuration and that the use of watercooled condensers and flat-plate collectors of higher efficiency increases this value to 1.35.

Lior, N.; Koai, K.

1984-05-01T23:59:59.000Z

466

Solar project description; for Houston Construction Company, single family residence, Eden Prairie, Minnesota  

SciTech Connect

The Houston Construction Company solar energy system is designed to provide 62 percent of the space heating and domestic hot water energy requirements for a single-family detached residence containing 1796 square feet. The residence is in Eden Prairie, MN. Energy collection is accomplished by 468 square feet of Solaron flat-plate collectors which face south at an angle of 60 degrees from the horizontal. Air is the medium for transfer of solar energy from the collectors to either the conditioned space or storage. Storage is a 314 ft/sup 3/ bin containing approximately 24,000 lbs of crushed rock located in a utility room. When solar energy is inadequate to satisfy the requirements of the space heating subsystem, auxiliary thermal energy is supplied from an 80,000 Btu/hr natural gas furnace. Domestic hot water is provided by a 30,000 Btu/hr natural gas water heater if the solar contribution is insufficient.

Not Available

1982-01-01T23:59:59.000Z

467

Integrated solar heating unit  

SciTech Connect

This patent describes an integral solar heating unit with an integral solar collector and hot water storage system, the unit comprising: (a) a housing; (b) a flat plate solar collector panel mounted in the housing and having a generally horizontal upper edge and an uninsulated, open back surface; (c) a cylindrical hot water tank operatively connected to the solar collector panel and mounted in the housing generally parallel to and adjacent to the upper edge; (d) the housing comprising a hood around the tank a pair of side skirts extending down at the sides of the panel. The hood and side skirts terminate at lower edges which together substantially define a plane such that upon placing the heating unit on a generally planar surface, the housing substantially encapsulates the collector panel and hot water tank in a substantially enclosed air space; (e) the collector including longitudinally extended U-shaped collector tubes and a glazed window to pass radiation through to the collector tubes, and a first cold water manifold connected to the tubes for delivering fresh water thereto and a second hot water manifold connected to the tubes to remove heated water therefrom. The manifolds are adjacent and at least somewhat above and in direct thermal contact with the tank; and, (f) the skirts and hood lapping around the collector panel, exposing only the glazed window, such that everything else in the heating unit is enclosed by the housing such that heat emanating from the uninsulated, open back face of the collector and tank is captured and retained by the housing to warm the manifolds.

Larkin, W.J.

1987-01-20T23:59:59.000Z

468

Utilization of Direct and Diffuse Sunlight in a Dye-Sensitized Solar Cell — Silicon Photovoltaic Hybrid Concentrator System  

Science Journals Connector (OSTI)

Nanocrystalline dye-sensitized solar cells (DSSCs) and organic photovoltaics (OPV) are two families of low-cost solar devices that absorb light in the visible part of the spectrum. ... del Cueto, J. A.Comparison of Energy Production and Performance from Flat-Plate Photovoltaic Module Technologies Deployed at Fixed Tilt. ... dye-sensitized solar cell as a top cell for high-energy photons, and a Cu In Ga selenide thin-film bottom cell for lower-energy photons, produces AM 1.5 solar to elec. ...

Greg D. Barber; Paul G. Hoertz; Seung-Hyun Anna Lee; Neal M. Abrams; Janine Mikulca; Thomas E. Mallouk; Paul Liska; Shaik M. Zakeeruddin; Michael Grätzel; Anita Ho-Baillie; Martin A. Green

2011-02-28T23:59:59.000Z

469

Cogenerating Photovoltaic and Thermal Solar Collector  

E-Print Network (OSTI)

cell, 25% max ­ Steam power plant, 50% max · Data Centers in the U.S. ­ Demand increases as internet.2% of the nations electricity consumption · Load equivalent to 5 1000 MW power plants · Over 2.2 billion dollars applications #12;First Prototype Spring 2008 #12;#12;Experimental Results · Thermal power generated ­ 1.4 KW

Su, Xiao

470

Two-axis tracking solar collector mechanism  

DOE Patents (OSTI)

This invention is a novel solar tracking mechanism incorporating a number of practical features that give it superior environmental resilience and exceptional tracking accuracy. The mechanism comprises a lightweight space-frame assembly supporting an array of point-focus Fresnel lenses in a two-axis tracking structure. The system is enclosed under a glass cover which isolates it from environmental exposure and enhances tracking accuracy by eliminating wind loading. Tracking accuracy is also enhanced by the system's broad-based tracking support. The system's primary intended application would be to focus highly concentrated sunlight into optical fibers for transmission to core building illumination zones, and the system may also have potential for photovoltaic or photothermal solar energy conversion.

Johnson, Kenneth C. (201 W. California Ave. #705, Sunnyvale, CA 94086)

1992-01-01T23:59:59.000Z

471

Day of Concern Collection / Ture Erickson (collector)  

E-Print Network (OSTI)

cut backs in educational funding and the perceived negative impact on the quality of education and education in general. Scope and Content The collection consists of records associated with Erickson, correspondence, clippings, memorabilia, posters and copies of addresses given at the Robson Square Media Centre

Handy, Todd C.

472

Dual purpose solar collectors. Final technical report  

SciTech Connect

Use of a single energy solar collecting system for two purposes is described. First, during the summer, the system was installed at a community swimming pool to reduce cost of maintaining water temperature, and second, during the winter the system was moved to and installed in the city maintenance building to reduce heating costs. Data collected and analyzed about use of renewable energy sources were disseminated to communities of similar size to encourage like use of energy conservation practices.

Not Available

1980-01-01T23:59:59.000Z

473

Capturing Sunlight: A Revolution in Collector Design  

Science Journals Connector (OSTI)

...heat swim-ming pools-reflecting in...Source: Grumman Energy Systems, Inc...sensitive to climate, efficiencies can range from 70...pump (60 F); swimming pool heat-ing (80...relying on back-up energy systems for the...

ALLEN L. HAMMOND; WILLIAM D. METZ

1978-07-07T23:59:59.000Z

474

Design of a solar thermal collector simulator.  

E-Print Network (OSTI)

??The recent increased interest in renewable energy has created a need for research in the area of solar technology. This has brought about many new… (more)

Bolton, Kirk G.

2009-01-01T23:59:59.000Z

475

Collector Field Maintenance: Distributed Solar Thermal Systems  

Science Journals Connector (OSTI)

This paper reports on recent operation and maintenance experiences with distributed solar thermal systems. Although some information on system-...

E. C. Boes; E. C. Cameron; E. L. Harley

1986-01-01T23:59:59.000Z

476

Transpired Solar Collector - Energy Innovation Portal  

NLE Websites -- All DOE Office Websites (Extended Search)

in regions away from the holes, which would reduce overall efficiency due to radiative loss of heat.DescriptionNREL researchers have discovered that high thermal-conductivity...

477

Two-axis tracking solar collector mechanism  

DOE Patents (OSTI)

This invention is a novel solar tracking mechanism incorporating a number of practical features that give it superior environmental resilience and exceptional tracking accuracy. The mechanism comprises a lightweight space-frame assembly supporting an array of point-focus Fresnel lenses in a two-axis tracking structure. The system is enclosed under a glass cover which isolates it from environmental exposure and enhances tracking accuracy by eliminating wind loading. Tracking accuracy is also enhanced by the system's broad-based tracking support. The system's primary intended application would be to focus highly concentrated sunlight into optical fibers for transmission to core building illumination zones, and the system may also have potential for photovoltaic or photothermal solar energy conversion. 16 figs.

Johnson, K.C.

1992-12-08T23:59:59.000Z

478

Two-axis tracking solar collector mechanism  

DOE Patents (OSTI)

This invention is a novel solar tracking mechanism incorporating a number of practical features that give it superior environmental resilience and exceptional tracking accuracy. The mechanism comprises a lightweight space-frame assembly supporting an array of point-focus Fresnel lenses in a two-axis tracking structure. The system is enclosed under a glass cover which isolates it from environmental exposure and enhances tracking accuracy by eliminating wind loading. Tracking accuracy is also enhanced by the system's broad-based tracking support. The system's primary intended application would be to focus highly concentrated sunlight into optical fibers for transmission to core building illumination zones, and the system may also have potential for photovoltaic or photothermal solar energy conversion.

Johnson, Kenneth C. (201 W. California Ave., #401, Sunnyvale, CA 94086)

1990-01-01T23:59:59.000Z

479

M/L{sub B} AND COLOR EVOLUTION FOR A DEEP SAMPLE OF M* CLUSTER GALAXIES AT z {approx} 1: THE FORMATION EPOCH AND THE TILT OF THE FUNDAMENTAL PLANE , ,  

SciTech Connect

We have measured velocity dispersions ({sigma}) for a sample of 36 galaxies with J < 21.2 or M{sub r} < -20.6 mag in MS 1054-03, a massive cluster of galaxies at z = 0.83. Our data are of uniformly high quality down to our selection limit, our 16 hr exposures typically yielding errors of only {delta}({sigma}) {approx} 10% for L* and fainter galaxies. By combining our measurements with data from the literature, we have 53 cluster galaxies with measured dispersions, and HST/ACS-derived sizes, colors and surface brightness. This sample is complete for the typical L* galaxy at z {approx} 1, unlike most previous z {approx} 1 cluster samples which are complete only for the massive cluster members (>10{sup 11} M{sub sun}). We find no evidence for a change in the tilt of the fundamental plane (FP). Nor do we find evidence for evolution in the slope of the color-{sigma} relation and M/L{sub B} -{sigma} relations; measuring evolution at a fixed {sigma} should minimize the impact of structural evolution found in other work. The M/L{sub B} at fixed {sigma} evolves by {Delta}log{sub 10} M/L{sub B} = -0.50 {+-} 0.03 between z = 0.83 and z = 0.02 or dlog{sub 10} M/L{sub B} = -0.60 {+-} 0.04 dz, and we find {Delta}(U - V){sub z} = -0.24 {+-} 0.02 mag at fixed {sigma} in the rest frame, matching the expected evolution in M/L{sub B} within 2.25 standard deviations. The implied formation redshift from both the color and M/L{sub B} evolution is z{sub *} = 2.0 {+-} 0.2 {+-} 0.3(sys), during the epoch in which the cosmic star formation activity peaked, with the systematic uncertainty showing the dependence of z{sub *} on the assumptions we make about the stellar populations. The lack of evolution in either the tilt of the FP or in the M/L-{sigma} and color-{sigma} relations imply that the formation epoch depends weakly on mass, ranging from z{sub *} = 2.3{sup +1.3}{sub -0.3} at {sigma} = 300 km s{sup -1} to z{sub *} = 1.7{sup +0.3}{sub -0.2} at {sigma} = 160 km s{sup -1} and implies that the initial mass function similarly varies slowly with galaxy mass.

Holden, B. P.; Illingworth, G. D. [UCO/Lick Observatories, University of California, Santa Cruz, CA 95065 (United States); Van der Wel, A. [Max-Planck Institute for Astronomy, Koenigstuhl 17, D-69117, Heidelberg (Germany); Kelson, D. D. [Observatories of the Carnegie Institution of Washington, Pasadena, CA 91101 (United States); Franx, M., E-mail: holden@ucolick.or, E-mail: gdi@ucolick.or, E-mail: vdwel@mpia.d, E-mail: kelson@obs.carnegiescience.ed, E-mail: franx@strw.leidenuniv.n [Sterrewacht Leiden, P.O. Box 9513, 2300 RA, Leiden (Netherlands)

2010-11-20T23:59:59.000Z

480

Comment on “Tilting of the CuO6 octahedra in La1.83-xEu0.17SrxCuO4 as seen by 151Eu Mössbauer spectroscopy”  

Science Journals Connector (OSTI)

We discuss the different characteristic time scales of the x-ray absorption fine structure (XAFS), ?X, and Mössbauer spectroscopy (MS), ?MS, techniques for structural determination at small-length scales. We show that XAFS and MS can measure different local atomic arrangements in La1.83-xEu0.17SrxCuO4 provided the local structural units are dynamical. Combined knowledge from these complementary techniques is used to determine that the local tilts of the CuO6 octahedra do not vanish with temperature but are dynamic, with the oxygen atoms at the apex positions [O(2)] hopping among local minima of the energy’s surface. Evidence is found for a crossover between different time domains in which the hopping time, ?0, changes from ?0?MS. We conclude that the Mössbauer results [Phys. Rev. B 54, R800 (1996)], contrary to the authors’ conclusions, do not contradict our XAFS results [Phys. Rev. Lett. 76, 439 (1996)].

Daniel Haskel; Edward A. Stern; Hanan Shechter

1998-04-01T23:59:59.000Z

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