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1

Lab Breakthrough: Desiccant Enhanced Evaporative Air Conditioning |  

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

Desiccant Enhanced Evaporative Air Conditioning Desiccant Enhanced Evaporative Air Conditioning Lab Breakthrough: Desiccant Enhanced Evaporative Air Conditioning May 29, 2012 - 5:22pm Addthis This breakthrough combines desiccant materials, which remove moisture from the air using heat, and advanced evaporative technologies to develop a cooling unit that uses 90 percent less electricity and up to 80 percent less total energy than traditional air conditioning. This solution, called the desiccant enhanced evaporative air conditioner (DEVAP), also controls humidity more effectively to improve the comfort of people in buildings. View the entire Lab Breakthrough playlist. What are the key facts? Recent materials advances and liquid desiccant advances to design the compact and cost-effective DEVAP system. DEVAP uses 90 percent less electricity and up to 80 percent less

2

Lab Breakthrough: Desiccant Enhanced Evaporative Air Conditioning |  

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

Lab Breakthrough: Desiccant Enhanced Evaporative Air Conditioning Lab Breakthrough: Desiccant Enhanced Evaporative Air Conditioning Lab Breakthrough: Desiccant Enhanced Evaporative Air Conditioning May 29, 2012 - 5:22pm Addthis This breakthrough combines desiccant materials, which remove moisture from the air using heat, and advanced evaporative technologies to develop a cooling unit that uses 90 percent less electricity and up to 80 percent less total energy than traditional air conditioning. This solution, called the desiccant enhanced evaporative air conditioner (DEVAP), also controls humidity more effectively to improve the comfort of people in buildings. View the entire Lab Breakthrough playlist. What are the key facts? Recent materials advances and liquid desiccant advances to design the compact and cost-effective DEVAP system.

3

Desiccant Enhanced Evaporative Air Conditioning: Parametric Analysis and Design; Preprint  

SciTech Connect

This paper presents a parametric analysis using a numerical model of a new concept in desiccant and evaporative air conditioning. The concept consists of two stages: a liquid desiccant dehumidifier and a dew-point evaporative cooler. Each stage consists of stacked air channel pairs separated by a plastic sheet. In the first stage, a liquid desiccant film removes moisture from the process (supply-side) air through a membrane. An evaporatively-cooled exhaust airstream on the other side of the plastic sheet cools the desiccant. The second-stage indirect evaporative cooler sensibly cools the dried process air. We analyze the tradeoff between device size and energy efficiency. This tradeoff depends strongly on process air channel thicknesses, the ratio of first-stage to second-stage area, and the second-stage exhaust air flow rate. A sensitivity analysis reiterates the importance of the process air boundary layers and suggests a need for increasing airside heat and mass transfer enhancements.

Woods, J.; Kozubal, E.

2012-10-01T23:59:59.000Z

4

Seminar 14 - Desiccant Enhanced Air Conditioning: Desiccant Enhanced Evaporative Air Conditioning (Presentation)  

SciTech Connect

This presentation explains how liquid desiccant based coupled with an indirect evaporative cooler can efficiently produce cool, dry air, and how a liquid desiccant membrane air conditioner can efficiently provide cooling and dehumidification without the carryover problems of previous generations of liquid desiccant systems. It provides an overview to a liquid desiccant DX air conditioner that can efficiently provide cooling and dehumidification to high latent loads without the need for reheat, explains how liquid desiccant cooling and dehumidification systems can outperform vapor compression based air conditioning systems in hot and humid climates, explains how liquid desiccant cooling and dehumidification systems work, and describes a refrigerant free liquid desiccant based cooling system.

Kozubal, E.

2013-02-01T23:59:59.000Z

5

Development and Analysis of Desiccant Enhanced Evaporative Air Conditioner Prototype  

SciTech Connect

This report documents the design of a desiccant enhanced evaporative air conditioner (DEVAP AC) prototype and the testing to prove its performance. Previous numerical modeling and building energy simulations indicate a DEVAP AC can save significant energy compared to a conventional vapor compression AC (Kozubal et al. 2011). The purposes of this research were to build DEVAP prototypes, test them to validate the numerical model, and identify potential commercialization barriers.

Kozubal, E.; Woods, J.; Judkoff, R.

2012-04-01T23:59:59.000Z

6

Desiccant Enhanced Evaporative Air-Conditioning (DEVap): Evaluation of a New Concept in Ultra Efficient Air Conditioning  

SciTech Connect

NREL has developed the novel concept of a desiccant enhanced evaporative air conditioner (DEVap) with the objective of combining the benefits of liquid desiccant and evaporative cooling technologies into an innovative 'cooling core.' Liquid desiccant technologies have extraordinary dehumidification potential, but require an efficient cooling sink. DEVap's thermodynamic potential overcomes many shortcomings of standard refrigeration-based direct expansion cooling. DEVap decouples cooling and dehumidification performance, which results in independent temperature and humidity control. The energy input is largely switched away from electricity to low-grade thermal energy that can be sourced from fuels such as natural gas, waste heat, solar, or biofuels.

Kozubal, E.; Woods, J.; Burch, J.; Boranian, A.; Merrigan, T.

2011-01-01T23:59:59.000Z

7

Investigations on Vapour Compression Air Conditioner with Direct Contact Desiccant Loop over Condenser and Evaporator  

E-Print Network (OSTI)

Perceived air quality increases when relative humidity is decreased till about 30% in the range of comfort temperature. In the present scenario, humidity is considered as a pollutant. Hence, a controlled environment not only at low temperature but also at low humidity is desired for many applications such as archives, data centers, etc. Either a separate dehumidifier or a precision air conditioning (AC) system needs to be employed for such an application. In fact, the latter forms a reheat AC system which happens to be energy inefficient. In view of this, a vapor compression window air conditioner is investigated with a superimposed liquid desiccant loop harnessing the advantages of both the compression system (high COP) and desiccant system (low humidity). Operation of such a novel system is explained, elucidating the operational feasibility. The results presented consider the characteristics of such a system with respect to changes in the evaporator inlet air temperature and humidity. The change in the specific humidity of air is compared for vapor compression system and the direct contact hybrid system for different values of inlet air temperature.

Maiya, M. P.; Ravi, J.; Tiwari, S.

2010-01-01T23:59:59.000Z

8

Analytical investigation of the desiccant enhanced nocturnal radiation cooling concept. Final report  

DOE Green Energy (OSTI)

A new concept in desiccant cooling called desiccant enhanced nocturnal radiation is proposed. The concept employs the roof of a typical residential building to act as a heat dissipator for the energy of sorption produced by a desiccant bed during a nightly adsorption cycle. During the day ambient air and solar radiation absorbed by the roof are used to regenerate the desiccant. The residence is assumed to contain the necessary thermal and moisture storage capacity to take advantage of the daily cycle. This report presents results of an analytical investigation of the adsorption and desorption cycles of the proposed concept using detailed finite element and boundary element modeling techniques.

Fairey, P.; Kerestecioglu, A.; Vieira, R.

1986-04-30T23:59:59.000Z

9

Development and Analysis of Desiccant Enhanced Evaporative Air...  

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

NREL National Renewable Energy Laboratory OA outdoor air P amb ambient pressure (psi) P fan fan power (kW) v PP polypropylene Q cooling total cooling (kW or Btuh) Q latent latent...

10

Desiccant Enhanced Evaporative Air-Conditioning (DEVap): Evaluation...  

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

to a small degree. We are working with AILR to increase the integration between LDACs and solar thermal collector with the clear goals of improving system performance and lowering...

11

Evaporative cooling enhanced cold storage system  

DOE Patents (OSTI)

The invention provides an evaporatively enhanced cold storage system wherein a warm air stream is cooled and the cooled air stream is thereafter passed into contact with a cold storage unit. Moisture is added to the cooled air stream prior to or during contact of the cooled air stream with the cold storage unit to effect enhanced cooling of the cold storage unit due to evaporation of all or a portion of the added moisture. Preferably at least a portion of the added moisture comprises water condensed during the cooling of the warm air stream. 3 figures.

Carr, P.

1991-10-15T23:59:59.000Z

12

Solar Desiccant Cooling  

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

Solar Desiccant Cooling Solar Desiccant Cooling Speaker(s): Paul Bourdoukan Date: December 6, 2007 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Ashok Gadgil The development of HVAC systems is a real challenge regarding its environmental impact. An innovative technique operating only by means of water and solar energy, is desiccant cooling. The principle is evaporative cooling with the introduction of a dehumidification unit, the desiccant wheel to control the humidity levels. The regeneration of the desiccant wheel requires a preheated airstream. A solar installation is a very interesting option for providing the preheated airstream. In France, at the University of La Rochelle, and at the National Institute of Solar Energy (INES), the investigation of the solar desiccant cooling technique has been

13

Evaporative Enhancement for Air Cooled Condensers  

Science Conference Proceedings (OSTI)

This report summarizes research into condenser air evaporative pre-cooling technologies and the associated potential for energy and peak power savings. The interest in this project is evaluation of the specific application of evaporative cooling to the inlet air of condenser coils, particularly for large roof-top type air cooled chillers. While the technology is established and understood particularly well for hot, dry climates, this report is intended to also examine evaporative ...

2013-03-06T23:59:59.000Z

14

A Preliminary Evaluation of Alternative Liquid Desiccants for a Hybrid Desiccant Air Conditioner  

E-Print Network (OSTI)

This paper presents the results of a preliminary investigation at The University of Texas at Austin of alternative liquid desiccants for use in a hybrid desiccant air-conditioning system in which a desiccant is circulated between the evaporator and the condenser of a vapor-compression air conditioner. The liquid desiccants studied were lithium chloride, lithium bromide, calcium chloride, and triethylene glycol. Each candidate desiccant was subjected to a screening process which weighed the merits of the desiccant in terms of selected characteristics. The best liquid desiccant for the anticipated application was found to be calcium chloride.

Studak, J. W.; Peterson, J. L.

1988-01-01T23:59:59.000Z

15

Innovative Evaporative and Thermally Activated Technologies Improve Air Conditioning, The Spectrum of Clean Energy Innovation (Fact Sheet)  

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

Innovative Evaporative and Innovative Evaporative and Thermally Activated Technologies Improve Air Conditioning Researchers at the National Renewable Energy Laboratory (NREL) invented a breakthrough technology that improves air conditioning in a novel way-with heat. NREL combined desiccant materials, which remove moisture from the air using heat, and advanced evaporative technologies to develop a cooling unit that uses 90% less electricity and up to 80% less total energy than traditional air conditioning (AC). This solution, called the desiccant enhanced evaporative air conditioner (DEVap), also controls humidity more effectively to improve the comfort of people in buildings. Desiccants are an example of a thermally activated technology (TAT) that relies on heat instead

16

Desiccant Cooling Systems - A Review  

E-Print Network (OSTI)

Desiccant cooling systems have been investigated extensively during the past decade as alternatives to electrically driven vapor compression systems because regeneration temperatures of the desiccant - about 160°F, can be achieved using natural gas or by solar systems. Comfort is achieved by reducing the moisture content of air by a solid or liquid desiccant and then reducing the temperature in an evaporative cooler (direct or indirect). Another system is one where the dehumidifier removes enough moisture to meet the latent portion of the load while the sensible portion is met by a vapor compression cooling system; desiccant regeneration is achieved by using the heat rejected from the condenser together with other thermal sources. At present, residential desiccant cooling systems are in actual operation but are more costly than vapor compression systems, resulting in relatively long payback periods. Component efficiencies need to be improved, particularly the efficiency of the dehumidifier.

Kettleborough, C. F.; Ullah, M. R.; Waugaman, D. G.

1986-01-01T23:59:59.000Z

17

A review of desiccant cooling systems  

SciTech Connect

This paper describes recent published design advances that have been made in desiccant cooling systems. In desiccant cooling cycles, the desiccant reduces the humidity of the air by removing moisture from the air. Then the temperature is reduced by other components such as heat exchangers, evaporative coolers, or conventional cooling coils. The main advantage that desiccant cooling systems offer is the capability of using low-grade thermal energy. Desiccant cooling systems for residential and commercial applications are now being used to reduce energy-operating costs. However, the initial costs are comparatively high. The focus of research for the past decade has been to develop desiccant systems with a high coefficient of performance. Recent studies have emphasized computer modeling and hybrid systems that combine desiccant dehumidifiers with conventional systems.

Waugaman, D.G.; Kini, A.; Kettleborough, C.F. (Texas A and M Univ., College Station (United States))

1993-03-01T23:59:59.000Z

18

Nanoparticle enhanced evaporation of liquids: A case study of silicone oil and water  

E-Print Network (OSTI)

Evaporation is a fundamental physical phenomenon, of which many challenging questions remain unanswered. Enhanced evaporation of liquids in some occasions is of enormous practical significance. Here we report the enhanced evaporation of the nearly permanently stable silicone oil by dispersing with nanopariticles including CaTiO3, anatase and rutile TiO2. The results can inspire the research of atomistic mechanism for nanoparticle enhanced evaporation and exploration of evaporation control techniques for treatment of oil pollution and restoration of dirty water.

Wenbin Zhang; Rong Shen; Kunquan Lu; Ailing Ji; Zexian Cao

2012-10-23T23:59:59.000Z

19

Performance Assessment of a Desiccant Cooling System in a CHP Application with an IC Engine  

DOE Green Energy (OSTI)

Performance of a desiccant cooling system was evaluated in the context of combined heat and power (CHP). The baseline system incorporated a desiccant dehumidifier, a heat exchanger, an indirect evaporative cooler, and a direct evaporative cooler. The desiccant unit was regenerated through heat recovery from a gas-fired reciprocating internal combustion engine. The system offered sufficient sensible and latent cooling capacities for a wide range of climatic conditions, while allowing influx of outside air in excess of what is typically required for commercial buildings. Energy and water efficiencies of the desiccant cooling system were also evaluated and compared with those of a conventional system. The results of parametric assessments revealed the importance of using a heat exchanger for concurrent desiccant post cooling and regeneration air preheating. These functions resulted in enhancement of both the cooling performance and the thermal efficiency, which are essential for fuel utilization improvement. Two approaches for mixing of the return air and outside air were examined, and their impact on the system cooling performance and thermal efficiency was demonstrated. The scope of the parametric analyses also encompassed the impact of improving the indirect evaporative cooling effectiveness on the overall cooling system performance.

Jalalzadeh-Azar, A. A.; Slayzak, S.; Judkoff, R.; Schaffhauser, T.; DeBlasio, R.

2005-04-01T23:59:59.000Z

20

Desiccant dehumidification analysis  

E-Print Network (OSTI)

Desiccant dehumidification has been given increasing interest in the air conditioning industry. Compared with conventional vapor compression air conditioning systems, desiccant dehumidification saves energy by separating ...

Xing, Hai-Yun Helen, 1976-

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

Enhancement of Tropical Ocean Evaporation and Sensible Heat Flux by Atmospheric Mesoscale Systems  

Science Conference Proceedings (OSTI)

The enhancement of monthly averaged evaporation by atmospheric mesoscale systems is estimated from long-term hourly observations of surface meteorological data from the Tropical Ocean Global Atmosphere (TOGA) Tropical Atmosphere Ocean (TAO) buoy ...

Steven K. Esbensen; Michael J. McPhaden

1996-10-01T23:59:59.000Z

22

Experiments on sorption hysteresis of desiccant materials  

DOE Green Energy (OSTI)

Solid desiccant cooling systems take advantage of solar energy for air conditioning. The process involves passing air through a desiccant bed for drying and subsequent evaporative cooling to provide the air conditioning. The desiccant is then regenerated with hot air provided by a gas burner or solar collectors. This performance is limited by the capacity of the desiccant, its sorption properties, and the long-term stability of the desiccant material under cyclic operation conditions. Therefore, we have developed a versatile test facility to measure the sorption properties of candidate solid desiccant materials under dynamic conditions, under different geometrical configurations, and under a broad range of process air stream conditions, characteristic of desiccant dehumidifer operation. We identified a dependence of the sorption processes on air velocity and the test cell aspect ratio and the dynamic hysteresis between adsorption and desorption processes. These experiments were geared to provide data on the dynamic performance of silica gel in a parallel-passage configuration to prepare for tests with a rotary dehumidifier that will be conducted at SERI in late FY 1984. We also recommend improving the accuracy of the isotopic perturbation technique.

Pesaran, A.; Zangrando, F.

1984-08-01T23:59:59.000Z

23

Improvements in solid desiccant cooling  

Science Conference Proceedings (OSTI)

The DINC (Direct-Indirect Evaporative Cooling) cycle was proposed in 1986 by Texas A and M researchers. The idea was to combine the benefits of direct and indirect evaporative cooling with desiccant dehumidifying using a rotating solid silica-gel dehumidifier. Recent parametric studies completed for the Texas Energy Research in Applications Program have developed a computer design for a nominal 3-ton system that would minimize the energy consumption (both thermal and electric) while maintaining a sensible heat ratio of 75% or less. That optimum design for the original 1986 DINC cycle was modified to improve its energy efficiency. The modifications described in this paper were: (1) staging the desiccant regeneration air and (2) recirculation of the primary air to the secondary side of the indirect evaporative cooling. Computer simulations were run to study the effect of the modifications on the performance of the system. American Refrigeration Institute (AIR) standard conditions (Ambient air at 35C, 40% R.H. and Room air at 26.7C, 50% R.H.) were used for all the modifications. Results were also compared to the familiar Pennington (ventilation) cycle. The study indicated that recirculating the indirect evaporative cooler air only degenerated the performance. However, staging a portion of the regeneration air could improve the thermal coefficient of Performance by 25% over the non-staged DINC cycle. Compared to a similar staged-regeneration Pennington cycle it is a 16% improvement in thermal COP and the sensible heat ratio was 70%.

Waugaman, D.; Kini, A.; Kettleborough, C.F. (Texas A and M Univ., College Station (United States))

1993-01-01T23:59:59.000Z

24

Desiccant contamination in desiccant cooling systems  

SciTech Connect

This paper presents the results of a desiccant contamination experiment and the impact of the obtained silica gel degradation data on the performance of a desiccant cooling system. A test apparatus was used to thermally cycle several desiccant samples and expose them to ambient'' humid air or contaminated'' humid air. The source of contamination was cigarette smoke. The exposed desiccant samples were removed after 0.5, 1, 2, or 4 months of exposure and their moisture capacities were measured. The silica get samples thermally cycled with ambient air showed a 5% to 30% to 70% of their moisture capacity. Using the obtained degradation data in a system, the impact of desiccant degradation on the performance of a desiccant cooling cycle was estimated. Depending on the degree of desiccant degradation, the decrease in thermal coefficient of performance (COP) and cooling capacity of the system was 10% to 35%. It was found that the COP and the cooling capacity of a system after desiccant degradation can be improved by increasing the rotational speed of the dehumidifier. This indicates that a simple engineering solution may exist to alleviate some type of degradations. 9 refs., 6 figs., 2 tabs.

Pesaran, A.A.

1990-08-01T23:59:59.000Z

25

STANDARDS CONTROLLING AIR EMISSIONS FOR THE SOIL DESICCATION PILOT TEST  

Science Conference Proceedings (OSTI)

This air emissions document supports implementation of the Treatability Test Plan for Soil Desiccation as outlined in the Deep Vadose Zone Treatability Test Plan for the Hanford Central Plateau (DOE/RL-2007-56). Treatability testing supports evaluation of remedial technologies for technetium-99 (Tc-99) contamination in the vadose zone at sites such as the BC Cribs and Trenches. Soil desiccation has been selected as the first technology for testing because it has been recommended as a promising technology in previous Hanford Site technology evaluations and because testing of soil desiccation will provide useful information to enhance evaluation of other technologies, in particular gas-phase remediation technologies. A soil desiccation pilot test (SDPT) will evaluate the desiccation process (e.g., how the targeted interval is dried) and the long-term performance for mitigation of contaminant transport. The SDPT will dry out a moist zone contaminated by Tc-99 and nitrate that has been detected at Well 299-E13-62 (Borehole C5923). This air emissions document applies to the activities to be completed to conduct the SDPT in the 200-BC-1 operable unit located in the 200 East Area of the Hanford Site. Well 299-E13-62 is planned to be used as an injection well. This well is located between and approximately equidistant from cribs 216-B-16, 216-B-17, 216-B-18. and 216-B-19. Nitrogen gas will be pumped at approximately 300 ft{sup 3}/min into the 299-EI3-62 injection well, located approximately 12 m (39 ft) away from extraction well 299-EI3-65. The soil gas extraction rate will be approximately 150 ft{sup 3}/min. The SDPT will be conducted continuously over a period of approximately six months. The purpose of the test is to evaluate soil desiccation as a potential remedy for protecting groundwater. A conceptual depiction is provided in Figure 1. The soil desiccation process will physically dry, or evaporate, some of the water from the moist zone of interest. As such, it is expected that Tc-99 and nitrate will remain with the water residual that is not removed, or remain as a salt bound to the soil particles. In addition, the SDPT will be conducted at lower extraction velocities to preclude pore water entrainment and thus, the extracted air effluent should be free of the contaminant residual present in the targeted moist zone. However, to conservatively bound the planned activity for potential radionuclide air emissions, it is assumed, hypothetically, that the Tc-99 does not remain in the zone of interest, but that it instead travels with the evaporated moisture to the extraction well and to the test equipment at the land surface. Thus, a release potential would exist from the planned point source (powered exhaust) for Tc-99 in the extracted moist air. In this hypothetical bounding case there would also be a potential for very minor fugitive emissions to occur due to nitrogen injection into the soil. The maximum value for Tc-99, measured in the contaminated moist zone, is used in calculating the release potential described in Section 2.3. The desiccation mechanism will be evaporation. Nitrate is neither a criteria pollutant nor a toxic air pollutant. It would remain nitrate as a salt adhered to sand and silt grains or as nitrate dissolved in the pore water. Nitrogen, an inert gas, will be injected into the ground during the test. Tracer gasses will also be injected near the beginning, middle, and the end of the test. The tracer gasses are sulfur hexafluoride, trichlorofluoromethane, and difluoromethane.

BENECKE MW

2010-09-08T23:59:59.000Z

26

Cromer Cycle Air Conditioner: A Unique Air-Conditioner Desiccant Cycle to Enhance Dehumidification and Save Energy  

E-Print Network (OSTI)

The Cromer cycle uses a desiccant to move moisture from the saturated air leaving an air conditioning (AC) cooling coil to the air returning to the AC unit from the conditioned space. This has the thermodynamic effect of reducing the overall energy consumption of the AC unit and also has the side benefit of dramatically increasing the moisture removal capacity of the AC coil. Simulations, engineering analysis and laboratory tests have confirmed the technical feasibility of the thermodynamics of the cycle. This work reports on a test at ARI conditions (95 deg. F outside, 80 deg F, 51% RH inside). The test unit (10 year old, 5 ton Bryant Air Conditioner) without the Cromer cycle, averaged an EER of 7.93 at a latent ratio of 26.2 % (SHR = 0.738). With the Cromer cycle added, the same unit averaged a total cooling EER of 11.82 with a water removal latent ratio of 53.4% (SHR= 0.466). The measured 16.4% reduction in energy use and 47.9 improvement in EER is significant for the tests at the 95% confidence level. This technology represents a major improvement in energy performance for the control of humidity conditions.

Cromer, C. J.

2000-01-01T23:59:59.000Z

27

Advanced desiccant materials research  

DOE Green Energy (OSTI)

The long-range goal of this task is to understand the role of surface phenomena in desiccant cooling materials. The background information includes a brief introduction to desiccant cooling systems (DCS) and the role of the desiccant as a system component. The purpose, background, rationale, and long-term technical approach for studying advanced desiccant materials are then treated. Experimental methods for measuring water vapor sorption by desiccants are described, and the rationale is then given for choosing a quartz crystal microbalance (QCM) for measuring sorption isotherms, rates, and cyclic stability. Background information is given about the QCM, including the quartz crystal resonator itself, the support structure for the quartz crystal, and the advantages and limitations of a QCM. The apparatus assembled and placed into operation during CY 1985 is described. The functions of the principal components of the equipment, i.e., the QCM, vacuum system, pressure gauges, residual gas analyzer, constant temperature bath, and data acquisition system, are described as they relate to the water vapor sorption measurements now under way. The criteria for narrowing the potential candidates as advanced desiccant materials for the initial studies are given. Also given is a list of 20 principal candidate materials identified based on the criteria and data available in the literature.

Czanderna, A.W.; Thomas, T.M.

1986-05-01T23:59:59.000Z

28

Using liquid desiccant as a regenerable filter for capturing and deactivating contaminants  

DOE Patents (OSTI)

A method, and systems for implementing such method, for purifying and conditioning air of weaponized contaminants. The method includes wetting a filter packing media with a salt-based liquid desiccant, such as water with a high concentration of lithium chloride. Air is passed through the wetted filter packing media and the contaminants in are captured with the liquid desiccant while the liquid desiccant dehumidifies the air. The captured contaminants are then deactivated in the liquid desiccant, which may include heating the liquid desiccant. The liquid desiccant is regenerated by applying heat to the liquid desiccant and then removing moisture. The method includes repeating the wetting with the regenerated liquid desiccant which provides a regenerable filtering process that captures and deactivates contaminants on an ongoing basis while also conditioning the air. The method may include filtration effectiveness enhancement by electrostatic or inertial means.

Slayzak, Steven J. (Denver, CO); Anderson, Ren S. (Broomfield, CO); Judkoff, Ronald D. (Golden, CO); Blake, Daniel M. (Golden, CO); Vinzant, Todd B. (Golden, CO); Ryan, Joseph P. (Golden, CO)

2007-12-11T23:59:59.000Z

29

Solar Desiccant Laboratory experiments  

DOE Green Energy (OSTI)

The first validation attempts with experimental data on SERI's in-house absorption computer model are reported. The SERI Desiccant Test Loop design is shown. Some experimental runs were made to extend the validation over a wide range of inlet (temperature/humidity) conditions. (MHR)

Kutscher, C.F.

1981-05-01T23:59:59.000Z

30

Composite desiccant structure  

DOE Patents (OSTI)

A composite formed of small desiccant particles retained in a dark matrix composed of a porous binder containing a transition metal oxide with pores to provide moisture transport with respect to the particles, and metallic fibers to remove the heat of condensation during dehumidification and provide heat for the removal of moisture during regeneration. The moisture absorbing properties of the composite may be regenerated by exposure of the dark matrix to solar radiation with dehumidification occurring at night.

Fraioli, Anthony V. (Hawthorn Woods, IL); Schertz, William W. (Batavia, IL)

1987-01-01T23:59:59.000Z

31

Composite desiccant structure  

DOE Patents (OSTI)

This patent discloses a composite formed of small desiccant particles retained in a dark matrix composed of a porous binder containing a transition metal oxide with pores to provide moisture transport with respect to the particles, and metallic fibers to remove the heat of condensation during dehumidification and provide heat for the removal of moisture during regeneration. The moisture absorbing properties of the composite may be regenerated by exposure of the dark matrix to solar radiation with dehumidification occurring at night.

Fraioli, A.V.; Schertz, W.W.

1984-06-06T23:59:59.000Z

32

Experimental investigation of a solar desiccant cooling installation  

Science Conference Proceedings (OSTI)

Desiccant cooling is a technique based on evaporative cooling and air dehumidification using desiccant regenerated by thermal energy. It is particularly interesting when it is driven by waste or solar heat making this technique environmentally friendly. In this paper, an experimental investigation is carried on a desiccant air handling unit powered by vacuum-tube solar collectors. First, the components are studied under various operating conditions. Then overall performance of the installation is evaluated over a day for a moderately humid climate with regeneration solely by solar energy. In these conditions the overall efficiency of the solar installation is 0.55 while the thermodynamic coefficient of performance is 0.45 and the performance indicator based on the electrical consumption is 4.5. Finally, the impact of outside and regeneration conditions on the performance indicators is studied. (author)

Bourdoukan, P.; Wurtz, E. [LOCIE Laboratoire Optimisation de la Conception et Ingenierie de l'Environnement, Campus Scientifique Universite de Savoie, 73376 Le Bourget du Lac (France); Joubert, P. [LEPTIAB Laboratoire d'Etude des Phenomenes de Transfert et de l'Instantaneite Agro-Industrie et Batiment Pole Sciences et Technologies, Universite La Rochelle, Avenue Marillac 17000 La Rochelle (France)

2009-11-15T23:59:59.000Z

33

Desiccant degradation in desiccant cooling systems: A system study  

Science Conference Proceedings (OSTI)

The authors predict the impact of desiccant degradation on the performance of an open-cycle desiccant cooling system in ventilation mode using the degradation data on silica gel obtained from a previous study. The degradation data were based on thermal cycling desiccant samples and exposing them to ambient or contaminated air. Depending on the degree of desiccant degradation, the decrease in the thermal coefficient of performance (COP) and the cooling capacity of the system for low-temperature regeneration was 10 percent to 35 percent. The 35 percent loss occurred based on the worst-case desiccant degradation scenario. Under more realistic conditions the loss in system performance is expected to be lower.

Pesaran, A.A. [National Renewable Energy Lab., Golden, CO (United States)

1993-11-01T23:59:59.000Z

34

Impact of desiccant degradation on desiccant cooling system performance  

Science Conference Proceedings (OSTI)

The performance of open-cycle desiccant cooling systems depends on several factors, some of which can change beyond manufacturers' specifications. For example, the desiccant sorption process may degrade with time on exposure to airborne contaminants and thermal cycling. Desiccant degradation can reduce the performance of a dehumidifier and thus the performance of desiccant cooling systems. Using computer simulations and recent experimental data on silica gel, the impact of degradation was evaluated. Hypothetical degradations of desiccants with Type 1 moderate isotherms were also simulated. Depending on the degree and type of desiccant degradation, the decrease in thermal coefficient of performance (COP) and cooling capacity of the system was 10% to 35%. The 35% loss in system performance occurs when desiccant degradation is considered worst case. The simulations showed that the COP, and to a lesser degree the cooling capacity of these degraded systems, could be improved by increasing the rotational speed of the dehumidifier. It is shown that easy engineering solutions might be available for some types of degradations. 9 refs., 6 figs., 1 tab.

Pesaran, A.A.; Penney, T.R.

1990-09-01T23:59:59.000Z

35

Enhancement of Evaporation from a Large Northern Lake by the Entrainment of Warm, Dry Air  

Science Conference Proceedings (OSTI)

The turbulent exchange of water vapor and heat were measured above Great Slave Lake, Northwest Territories, Canada, using the eddy covariance method for most of the ice-free period in 1997, 1998, and 1999. In all years, evaporation tended to ...

Peter D. Blanken; Wayne R. Rouse; William M. Schertzer

2003-08-01T23:59:59.000Z

36

Desiccant degradation in desiccant cooling systems: An experimental study  

SciTech Connect

The authors conducted experiments to quantify the effects of thermal cycling and exposure to contamination on solid desiccant materials that may be used in desiccant cooling systems. The source of contamination was cigarette smoke, which is considered one of the worst pollutants in building cooling applications. The authors exposed five different solid desiccants to ``ambient`` and ``contaminated`` humid air: silica gel, activated alumina, activated carbon, molecular sieves, and lithium chloride. They obtained the moisture capacity of samples as a function of exposure time. Compared to virgin desiccant samples, the capacity loss caused by thermal cycling with humid ambient air was 10 percent to 30 percent for all desiccants. The capacity loss because of combined effect of thermal cycling with ``smoke-filled`` humid air was between 30 percent to 70 percent. The higher losses occurred after four months of experiment time, which is equivalent to four to eight years of field operation. Using a system model and smoke degradation data on silica gel, the authors predicted that, for low-temperature regeneration, the loss in performance of a ventilation-cycle desiccant cooling system would be between 10 percent to 35 percent, in about eight years, with higher value under worst conditions.

Pesaran, A.A. [National Renewable Energy Lab., Golden, CO (United States)

1993-11-01T23:59:59.000Z

37

Review of Desiccant Dehumidification Technology  

DOE Green Energy (OSTI)

This paper overviews applications of desiccant technology for dehumidifying commercial and institutional buildings. Because of various market, policy, and regulatory factors, this technology is especially attractive for dehumidification applications in the I990s.

Pesaran, A. A.

1994-10-01T23:59:59.000Z

38

Desiccant contamination research: Report on the desiccant contamination test facility  

DOE Green Energy (OSTI)

The activity in the cooling systems research involves research on high performance dehumidifiers and chillers that can operate efficiently with the variable thermal outputs and delivery temperatures associated with solar collectors. It also includes work on advanced passive cooling techniques. This report describes the work conducted to improve the durability of solid desiccant dehumidifiers by investigating the causes of degradation of desiccant materials from airborne contaminants and thermal cycling. The performance of a dehumidifier strongly depends on the physical properties and durability of the desiccant material. To make durable and reliable dehumidifiers, an understanding is needed of how and to what degree the performance of a dehumidifier is affected by desiccant degradation. This report, an account of work under Cooling Systems Research, documents the efforts to design and fabricate a test facility to investigate desiccant contamination based on industry and academia recommendations. It also discusses the experimental techniques needed for obtaining high-quality data and presents plans for next year. Researchers of the Mechanical and Industrial Technology Division performed this work at the Solar Energy Research Institute in FY 1988 for DOE's Office of Solar Heat Technologies. 7 refs., 19 figs., 1 tab.

Pesaran, A.A.; Bingham, C.E.

1991-07-01T23:59:59.000Z

39

Desiccant contamination research: Report on the desiccant contamination test facility  

SciTech Connect

The activity in the cooling systems research involves research on high performance dehumidifiers and chillers that can operate efficiently with the variable thermal outputs and delivery temperatures associated with solar collectors. It also includes work on advanced passive cooling techniques. This report describes the work conducted to improve the durability of solid desiccant dehumidifiers by investigating the causes of degradation of desiccant materials from airborne contaminants and thermal cycling. The performance of a dehumidifier strongly depends on the physical properties and durability of the desiccant material. To make durable and reliable dehumidifiers, an understanding is needed of how and to what degree the performance of a dehumidifier is affected by desiccant degradation. This report, an account of work under Cooling Systems Research, documents the efforts to design and fabricate a test facility to investigate desiccant contamination based on industry and academia recommendations. It also discusses the experimental techniques needed for obtaining high-quality data and presents plans for next year. Researchers of the Mechanical and Industrial Technology Division performed this work at the Solar Energy Research Institute in FY 1988 for DOE's Office of Solar Heat Technologies. 7 refs., 19 figs., 1 tab.

Pesaran, A.A.; Bingham, C.E.

1991-07-01T23:59:59.000Z

40

Application of Desiccant Drying in Plastic Molding  

E-Print Network (OSTI)

Desiccants are materials that have an affinity, after heating, for water vapor. Desiccant materials have long been applied in industrial processes requiring low humidity environments. A gas-fired desiccant system improved the productivity of one blowmolding process by reducing the number of defects and allowing an increase in line speed. The environmental impact of the operation improved because electrical usage did not increase incrementally and CFC usage did not change. A comparison of the efficiency of desiccant and refrigeration dehumidification is presented.

Brown, M.; Connors, G.; Moore, D.

1993-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

New Adsorbent Materials for Desiccant Cooling  

dehumidification systems. ... as having superior performance to the primary commercial ... The majority of desiccant dehumidification systems used for ...

42

Theoretical and experimental analysis of desiccant wheel performance for low humidity drying system  

Science Conference Proceedings (OSTI)

The drying process is influenced by three main factors temperature, flow rate and humidity, resulting in the drying process of hot air required in accordance with the character of materials with low humidity, so it can speed up the drying process. Malaysia ... Keywords: desiccant wheel, temperature and humidity, water evaporation

Tri Suyono; Sohif Mat; Muhammad Yahya; Muhd. Hafiz Ruslan; Azami Zaharim; Kamaruzzaman Sopian

2011-10-01T23:59:59.000Z

43

Assessment of Evaporative Cooling Enhancement Methods for Air-Cooled Geothermal Power Plants: Preprint  

DOE Green Energy (OSTI)

Many binary-cycle geothermal power plants are air cooled because insufficient water is available to provide year-round water cooling. The performance of air-cooled geothermal plants is highly dependent on the dry bulb temperature of the air (much more so than fossil fuel plants that operate at higher boiler temperatures), and plant electric output can drop by 50% or more on hot summer days, compared to winter performance. This problem of reduced summer performance is exacerbated by the fact that electricity has a higher value in the summer. This paper describes a spreadsheet model that was developed to assess the cost and performance of four methods for using supplemental evaporative cooling to boost summer performance: (1) pre-cooling with spray nozzles, (2) pre-cooling with Munters media, (3) a hybrid combination of nozzles and Munters media, and (4) direct deluge cooling of the air-cooled condenser tubes. Although all four options show significant benefit, deluge cooling has the potential to be the most economic. However, issues of scaling and corrosion would need to be addressed.

Kutscher, C.; Costenaro, D.

2002-08-01T23:59:59.000Z

44

Active Humidity Control Through Gas-Fired Desiccant Humidity Pump  

E-Print Network (OSTI)

High equipment first cost and high operating costs, if electricity is used to drive such a system, have prohibited the application of active humidity control equipment in comfort conditioning in the past. Instead, passive techniques have been applied. A comparison of passive capacity control methods to control humidity shows that only the combined face and bypass and variable air volume system shows improved performance with respect to space humidity control, dew point depression, and response to perturbations. A gas-fired desiccant humidity pump will provide economical humidity control in existing and new construction using VAV or constant volume air distribution systems. The humidity pump is designed as a packaged make-up air module. It is coupled to new or existing conventional air-conditioning system via a duct. It consists of a triple integrated heat-exchanger combining (liquid) desiccant dehumidification with indirect evaporative cooling, a brine interchanger, and a gas-fired brine heater to regenerate the desiccant. Field experiments of two humidity pumps on existing commercial buildings have been initiated. Each system dehumidifies 5000 scfm of make-up air to meet all the latent loads, which is then fed to conventional, electric-driven HVAC equipment which meet all the sensible loads.

Novosel, D.; Griffiths, W. C.

1988-01-01T23:59:59.000Z

45

Simulation and study of thermal performance of liquid desiccant cooling cycle configurations  

E-Print Network (OSTI)

Five configurations of a 3-ton liquid desiccant cooling cycle were simulated and analyzed on a digital computer. Algebraic equations were developed for the dry bulbtemperatures and humidity ratios at different locations in the systems and solved using a finite difference scheme. The simulations were done at steady state and standard ASHRAE indoor and outdoor conditions. The study compared thermal performance of these five system configurations consisting of a direct evaporative cooler, indirect evaporative cooler(s), liquid desiccant packed dehumidifying tower, and air-to-air heat exchanger. Constant effectiveness of 0.85 and 0.9 were assumed for the direct evaporative cooler and air-to-air heat exchanger respectively. The performance of these five cycles is judged by the thermal Coefficient of Performance (COP). The Sensible Heat Ratio (SHR) is used to quantify the ratio of sensible cooling provided to the total cooling done (sensible plus latent).

Dhir, Rajesh

1995-01-01T23:59:59.000Z

46

Analysis of solar desiccant systems and concepts  

DOE Green Energy (OSTI)

A new approach to modeling desiccant systems has been developed. Computer programs for predicting the performance silica gel beds in single-blow situations and in cyclically operating desiccant cooling systems have been written (DESSIM). The single-blow model has been validated and shows excellent agreement with experimental data from SERI's desiccant test lab. Experimental data published by Koh are shown along with the corresponding prediction using DESSIM.

Barlow, R.

1981-05-01T23:59:59.000Z

47

Liquid Desiccant Drying of Thermoreversibly Gelcast Bodies  

Science Conference Proceedings (OSTI)

Presentation Title, Liquid Desiccant Drying of Thermoreversibly Gelcast Bodies. Author(s), Noah O Shanti, Katherine T Faber. On-Site Speaker (Planned), Noah ...

48

Polymers as Advanced Materials for Desiccant Applications: 1987  

DOE Green Energy (OSTI)

This research is concerned with solid materials used as desiccants for desiccant cooling systems that process water vapor in an atmosphere to produce net cooling.

Czanderna, A. W.

1988-12-01T23:59:59.000Z

49

Heat and mass transfer in packed bed liquid desiccant regenerators -- An experimental investigation  

Science Conference Proceedings (OSTI)

Liquid desiccant cooling can provide control of temperature and humidity, while at the same time lowering the electrical energy requirement for air conditioning. Since the largest energy requirement associated with desiccant cooling is low temperature heat for desiccant regeneration, the regeneration process greatly influences the overall system performance. Therefore, the effects of variables such as air and desiccant flow rates, air temperature and humidity, desiccant temperature and concentration, and the area available for heat and mass transfer on the regeneration process are of great interest. Due to the complexity of the regeneration process, which involves simultaneous heat and mass transfer, theoretical modeling must be verified by experimental studies. However, a limited number of experimental studies are reported in the literature. This paper presents results from a detailed experimental investigation of the heat and mass transfer between a liquid desiccant (triethylene glycol) and air in a packed bed regenerator using high liquid flow rates. To regenerate the desiccant, it is heated to temperatures readily obtainable from flat-plate solar collectors. A high performance packing that combines good heat and mass transfer characteristics with low pressure drop is used. The rate of water evaporation, as well as the effectiveness of the regeneration process is assessed based on the variables listed above. Good agreement is shown to exist between the experimental findings and predictions from finite difference modeling. In addition, the findings in the present study are compared to findings previously reported in the literature. Also, the results presented here characterize the important variables that impact the system design.

Martin, V.; Goswami, D.Y.

1999-08-01T23:59:59.000Z

50

Thermally Activated Desiccant Technology for Heat Recovery and Comfort  

DOE Green Energy (OSTI)

Desiccant cooling is an important part of the diverse portfolio of Thermally Activated Technologies (TAT) designed for conversion of heat for the purpose of indoor air quality control. Thermally activated desiccant cooling incorporates a desiccant material that undergoes a cyclic process involving direct dehumidification of moist air and thermal regeneration. Desiccants fall into two categories: liquid and solid desiccants. Regardless of the type, solid or liquid, the governing principles of desiccant dehumidification systems are the same. In the dehumidification process, the vapor pressure of the moist air is higher than that of the desiccant, leading to transfer of moisture from the air to the desiccant material. By heating the desiccant, the vapor pressure differential is reversed in the regeneration process that drives the moisture from the desiccant. Figure 1 illustrates a rotary solid-desiccant dehumidifier. A burner or a thermally compatible source of waste heat can provide the required heat for regeneration.

Jalalzadeh, A. A.

2005-11-01T23:59:59.000Z

51

Facilities for testing desiccant materials and geometries of dehumidifiers for solar-regenerated desiccant cooling systems  

SciTech Connect

Four experimental test facilities for characterizing the performance of solid desiccant materials and dehumidifier matrices which have the potential to be used in solar-regenerated desiccant cooling systems are reviewed. The water equilibrium capacity and sorption rates of desiccant materials, depending on their form, can be either measured with a quartz crystal microbalance or a desiccant sorption test facility. Pressure drop, heat- and mass-transfer rates and transient equilibrium dehumidification capacity of a dehumidifier matrices are measured in a desiccant heat and mass transfer test facility. The performance and steady state dehumidification capabilities of prototype dehumidifier components under realistic conditions are measured in a desiccant cyclic test facility. The description of the test apparatus, experimental procedure, measurement errors, and typical results for the four test facilities are presented here. 15 refs., 9 figs., 1 tab.

Pesaran, A.A.; Bingham, C.E.

1988-12-01T23:59:59.000Z

52

Underground-desiccant cooling system  

DOE Green Energy (OSTI)

The Underground-Desiccant Cooling System relies on the successful coordination of various components. The central feature of the system is a bed of silica gel which will absorb moisture from house air until the gel has become saturated. When this point has been reached, the silica gel must be regenerated by passing hot air through it. For this project, the hot air is produced by air-type solar collectors mounted on the roof and connected with the main air-handling system by means of ducts attached to the outside of the house. As the air is dehumidified its temperature is raised somewhat by the change of state. The dried but somewhat heated air, after leaving the silica gel bed, passes through a rock bin storage area and then past a water coil chiller before being circulated through the house by means of the previously existing ductwork. The cooling medium for both the rock bin and the chiller coil is water which circulates through underground pipes buried beneath the back yard at a depth of about 10 to 12 ft. When the silica gel is being regenerated by the solar collectors, house air bypasses the desiccant bed but still passes through the rock bin and the chiller coil and is cooled continuously. The system is designed for maximum flexibility so that full use can be made of the solar collectors. Ducting is arranged so that the collectors provide heat for the house in the winter and there is also a hot-water capability year-round.

Finney, O.

1982-10-01T23:59:59.000Z

53

Energy Basics: Evaporative Cooling  

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

absorbent material. Evaporative cooling uses evaporated water to naturally and energy-efficiently cool. How Evaporative Coolers Work There are two types of evaporative...

54

Advanced Open-Cycle Desiccant Cooling System  

E-Print Network (OSTI)

The concept of staged regeneration as means of improving the desiccant cooling system performance is the subject of investigation in this study. In the staged regeneration, the regeneration section of desiccant dehumidifier is divided into two parts and only the latter fraction is subjected to the desorption air stream which has been heated to the desired regeneration temperature. In the present work, the mathematical model describing the heat and mass transfer processes that occur during sorption of moisture in the desiccnnt dehumidifier includes both the gas-side (film) and solid-side resistances for heat and mass transports. The moisture diffusion in the desiccant material is expressed by gas-phase diffusion and surface diffusion. Effects of several parameters on the performance of desiccant cooling system with staged regeneration are investigated and the results of present model are compared with those of the lumped-resistance model. Results of this study show that coefficient of perfomnnce of the desiccant cooling system can be substantially improved by using the staged regeneration concept. There is an optimum stage fraction and optimum cycle time for given system parmeters and operating conditions. The results also indicate that the cooling system performance is higher than that predicted by the lumped-resistance model.

Ko, Y. J.; Charoensupaya, D.; Lavan, Z.

1989-01-01T23:59:59.000Z

55

Parametric Analysis of a Solar Desiccant Cooling System using...  

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

Parametric Analysis of a Solar Desiccant Cooling System using the SimSPARK Environment Title Parametric Analysis of a Solar Desiccant Cooling System using the SimSPARK Environment...

56

Solar air conditioning system using desiccant wheel technology  

Science Conference Proceedings (OSTI)

The electrical energy consumption in Malaysia has increased sharply in the past few years. Modern energy efficient technologies are desperately needed for the national energy policy. In this paper, a new design of desiccant cooling is being developed ... Keywords: air-conditioning, desiccant cooling, solar thermal energy, solid desiccant

Arfidian Rachman; Sohif Mat; Taib Iskandar; M. Yahya; Azami Zaharim; Kamaruzzaman Sopian

2010-10-01T23:59:59.000Z

57

Experiments on sorption characteristics of solid desiccant materials for solar desiccant cooling systems  

DOE Green Energy (OSTI)

A test facility for measuring the sorption properties of candidate solid desiccant materials under dynamic conditions as well as equilibrium conditions, those experienced during desiccant dehumidifier operation, was constructed and tested. The theory of perturbation chromatography was initially used to measure the equilibrium properties of a desiccant/water-vapor system for the first time. Silica gel, molecular sieve, and gamma-manganese dioxide were tested. The equilibrium capacity estimated by the perturbation chromatography was lower than those available in literature, which suggests that perturbation chromatography may not be applicable to desiccant/water-vapor systems. The perturbation chromatography was replaced with a gravimetric technique, and satisfactory results were obtained for a water-vapor/molecular-sieve system.

Pesaran, A.A.

1984-11-01T23:59:59.000Z

58

Polymers as advanced materials for desiccant applications  

DOE Green Energy (OSTI)

This research is concerned with solid materials used as desiccants for desiccant cooling systems (DCSs) that process water vapor in an atmosphere to produce cooling. Background information includes an introduction to DCSs and the role of the desiccant as a system component. The water vapor sorption performance criteria used for screening the modified polymers prepared include the water sorption capacity from 5% to 80% relative humidity (R.H.), isotherm shape, and rate of adsorption and desorption. Measurements are presented for the sorption performance of modified polymeric advanced desiccant materials with the quartz crystal microbalance. Isotherms of polystyrene sulfonic acid (PSSA) taken over a 5-month period show that the material has a dramatic loss in capacity and that the isotherm shape is time dependent. The adsorption and desorption kinetics for PSSA and all the ionic salts of it studied are easily fast enough for commercial DCS applications with a wheel rotation speed of 6 min per revolution. Future activities for the project are addressed, and a 5-year summary of the project is included as Appendix A. 34 refs., 20 figs., 3 tabs.

Czanderna, A.W.

1990-12-01T23:59:59.000Z

59

Desiccant cooling using unglazed transpired solar collectors  

DOE Green Energy (OSTI)

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); Wipke, K. [Stanford Univ., CA (United States)

1992-05-01T23:59:59.000Z

60

Performance of cross-cooled desiccant dehumidifiers  

DOE Green Energy (OSTI)

A cross-cooled silica gel desiccant dehumidifier model was designed, built and tested. The performance of the unit was studied as a function of inlet process stream dew point, process stream and cooling stream flowrates and regeneration stream temperature and dew point. The tests were also simulated by a computer program and were compared to the experimental results.

Mei, V.C.; Lavan, Z.

1980-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

Effects of Porous Medium Heterogeneity on Vadose Zone Desiccation: Intermediate-scale Laboratory Experiments and Simulations  

Science Conference Proceedings (OSTI)

Soil desiccation (drying), involving water evaporation induced by dry gas injection, is a potentially robust vadose zone remediation process to limit contaminant transport through the vadose zone. A series of four intermediate-scale flow cell experiments was conducted in homogeneous and simple layered heterogeneous porous medium systems to investigate the effects of heterogeneity on desiccation of unsaturated porous media. The permeability ratios of porous medium layers ranged from about five to almost two orders of magnitude. The insulated flow cell was equipped with twenty humidity and temperature sensors and a dual-energy gamma system was used to determine water saturations at various times. The multiphase code STOMP was used to simulate the desiccation process. Results show that injected dry gas flowed predominantly in the higher permeability layer and delayed water removal from the lower permeability material. For the configurations tested, water vapor diffusion from the lower to the higher permeability zone was considerable over the duration of the experiments, resulting in much larger relative humidity values of the outgoing air than based on permeability ratios alone. Acceptable numerical matches with the experimental data were obtained when an extension of the saturation-capillary pressure relation below the residual water saturation was used. The agreements between numerical and experimental results suggest that the correct physics are implemented in the simulator and that the thermal and hydraulic properties of the porous media, flow cell wall and insulation materials were properly represented.

Oostrom, Martinus; Freedman, Vicky L.; Wietsma, Thomas W.; Dane, Jacob H.; Truex, Michael J.

2012-11-01T23:59:59.000Z

62

Desiccant cooling: State-of-the-art assessment  

SciTech Connect

The objectives of this document are to present an overview of the work accomplished to date on desiccant cooling to provide assessment of the state of the art of desiccant cooling technology in the field of desiccant material dehumidifier components, desiccant systems, and models. The report also discusses the factors that affect the widespread acceptance of desiccant cooling technology. This report is organized as follows. First, a basic description and historical overview of desiccant cooling technology is provided. Then, the recent research and development (R D) program history (focusing on DOE's funded efforts) is discussed. The status of the technology elements (materials, components, systems) is discussed in detail and a preliminary study on the energy impact of desiccant technology is presented. R D needs for advancing the technology in the market are identified. The National Renewable Energy Laboratory's unique desiccant test facilities and their typical outputs are described briefly. Finally, the results of a comprehensive literature search on desiccant cooling are presented in a bibliography. The bibliography contains approximately 900 citations on desiccant cooling.

Pesaran, A.A.; Penney, T.R.; Czanderna, A.W.

1992-10-01T23:59:59.000Z

63

Desiccant cooling: State-of-the-art assessment  

SciTech Connect

The objectives of this document are to present an overview of the work accomplished to date on desiccant cooling to provide assessment of the state of the art of desiccant cooling technology in the field of desiccant material dehumidifier components, desiccant systems, and models. The report also discusses the factors that affect the widespread acceptance of desiccant cooling technology. This report is organized as follows. First, a basic description and historical overview of desiccant cooling technology is provided. Then, the recent research and development (R&D) program history (focusing on DOE`s funded efforts) is discussed. The status of the technology elements (materials, components, systems) is discussed in detail and a preliminary study on the energy impact of desiccant technology is presented. R&D needs for advancing the technology in the market are identified. The National Renewable Energy Laboratory`s unique desiccant test facilities and their typical outputs are described briefly. Finally, the results of a comprehensive literature search on desiccant cooling are presented in a bibliography. The bibliography contains approximately 900 citations on desiccant cooling.

Pesaran, A.A.; Penney, T.R.; Czanderna, A.W.

1992-10-01T23:59:59.000Z

64

Experimental Results on Advanced Rotary Desiccant Dehumidifiers  

E-Print Network (OSTI)

The Solar Energy Research Institute (SERI) has developed the Cyclic Test Facility (CTF) to develop and validate analytical methods for evaluating and predicting the performance of advanced rotary dehumidifiers. This paper describes the CTF, the dehumidifiers tested at the CTF, and the analytical methods used. The results reported provide an engineering data base and a design tool for evaluating rotary dehumidifiers for desiccant cooling applications.

Barathan, D.; Parsons, J. M.; MaClaine-Cross, I.

1986-01-01T23:59:59.000Z

65

Experimental results on advanced rotary desiccant dehumidifiers  

DOE Green Energy (OSTI)

The Solar Energy Research Institute (SERI) has developed the Cyclic Test Facility (CTF) to develop and validate analytical methods for evaluating and predicting the performance of advanced rotary dehumidifiers. This paper describes the CTF, the dehumidifiers tested at the CTF, and the analytical methods used. The results reported provide an engineering data base and a design tool for evaluating rotary dehumidifiers for desiccant cooling applications.

Bharathan, D.; Parsons, J.; Maclaine-cross, I.

1986-08-01T23:59:59.000Z

66

Analysis of Hybrid Liquid Desiccant Technologies  

Science Conference Proceedings (OSTI)

Dehumidification technology is being investigated for potential savings in building air conditioning systems. The potential for savings lies in separating the sensible and latent cooling loads to more efficiently address the combined conditioning needs of the space. Two DuCool liquid desiccant systemsDuTreat and DuHandlingwere tested in the Electric Power Research Institute (EPRI) Knoxville, Tennessee psychrometric chambers. The DuCool uses an internal vapor compression system to regenerate a liquid desi...

2011-05-09T23:59:59.000Z

67

A review of desiccant dehumidification technology  

SciTech Connect

This paper overviews applications of desiccant technology for dehumidifying commercial and institutional buildings. Because of various market, policy, and regulatory factors, this technology is especially attractive for dehumidification applications in the 1990s. After briefly reviewing the principle of operation, the authors present three case studies-for supermarkets, a hotel, and an office building. The authors also discuss recent advances and ongoing research and development activities.

Pesaran, A.A.

1994-10-01T23:59:59.000Z

68

New and Underutilized Technology: Liquid Desiccant Air Conditioner |  

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

Liquid Desiccant Air Conditioner Liquid Desiccant Air Conditioner New and Underutilized Technology: Liquid Desiccant Air Conditioner October 4, 2013 - 4:40pm Addthis The following information outlines key deployment considerations for liquid desiccant air conditioners (LDACs) within the Federal sector. Benefits Liquid desiccant air conditioners deeply dry air using natural gas, solar energy, waste heat, bio-fuel, or other fossil fuels to drive the system. By providing mostly latent cooling, the LDAC controls indoor humidity without overcooling and reheating. This unit is supplemented by an electric chiller or DX air conditioner that sensibly cools the building's recirculation air. The liquid desiccant is a concentrated salt solution that directly absorbs moisture. Application LDACs are applicable in hospital, office, prison, school, and service

69

Overview of Open-Cycle Desiccant Cooling Systems and Materials  

DOE Green Energy (OSTI)

This paper has presented a review of the thermodynamics of three desiccant cooling cycles: the ventilation cycle, the recirculation cycle, and the Dunkle cycle. For the ventilation cycle the qualitative effects of changes in the effectiveness of individual components were analyzed. There are two possible paths to improved dehumidifier performance: changing the design of dehumidifiers using currently available desiccants so as to increase effectiveness without increasing parasitic losses, or developing new desiccants specifically tailored for solar cooling applications. The later part of this paper has considered the second option. A list of desirable desiccant properties was defined, properties of currently used solid and liquid desiccants were compared to this list, and a hypothetical desiccant type that would give improved system performance was discussed.

Collier, R.; Arnold, F.; Barlow, R.

1981-09-01T23:59:59.000Z

70

Desiccant dehumidification and cooling systems assessment and analysis  

SciTech Connect

The objective of this report is to provide a preliminary analysis of the principles, sensitivities, and potential for national energy savings of desiccant cooling and dehumidification systems. The report is divided into four sections. Section I deals with the maximum theoretical performance of ideal desiccant cooling systems. Section II looks at the performance effects of non-ideal behavior of system components. Section III examines the effects of outdoor air properties on desiccant cooling system performance. Section IV analyzes the applicability of desiccant cooling systems to reduce primary energy requirements for providing space conditioning in buildings. A basic desiccation process performs no useful work (cooling). That is, a desiccant material drying air is close to an isenthalpic process. Latent energy is merely converted to sensible energy. Only when heat exchange is applied to the desiccated air is any cooling accomplished. This characteristic is generic to all desiccant cycles and critical to understanding their operation. The analyses of Section I show that desiccant cooling cycles can theoretically achieve extremely high thermal CoP`s (>2). The general conclusion from Section II is that ventilation air processing is the most viable application for the solid desiccant equipment analyzed. The results from the seasonal simulations performed in Section III indicate that, generally, the seasonal performance of the desiccant system does not change significantly from that predicted for outdoor conditions. Results from Section IV show that all of the candidate desiccant systems can save energy relative to standard vapor-compression systems. The largest energy savings are achieved by the enthalpy exchange devise.

Collier, R.K. Jr. [Collier Engineering, Reno, NV (United States)

1997-09-01T23:59:59.000Z

71

Energy-efficient regenerative liquid desiccant drying process  

DOE Patents (OSTI)

This invention relates to the use of desiccants in conjunction with an open oop drying cycle and a closed loop drying cycle to reclaim the energy expended in vaporizing moisture in harvested crops. In the closed loop cycle, the drying air is brought into contact with a desiccant after it exits the crop drying bin. Water vapor in the moist air is absorbed by the desiccant, thus reducing the relative humidity of the air. The air is then heated by the used desiccant and returned to the crop bin. During the open loop drying cycle the used desiccant is heated (either fossil or solar energy heat sources may be used) and regenerated at high temperature, driving water vapor from the desiccant. This water vapor is condensed and used to preheat the dilute (wet) desiccant before heat is added from the external source (fossil or solar). The latent heat of vaporization of the moisture removed from the desiccant is reclaimed in this manner. The sensible heat of the regenerated desiccant is utilized in the open loop drying cycle. Also, closed cycle operation implies that no net energy is expended in heating drying air.

Ko, Suk M. (Huntsville, AL); Grodzka, Philomena G. (Huntsville, AL); McCormick, Paul O. (Athens, AL)

1980-01-01T23:59:59.000Z

72

Desiccant cooling and dehumidification opportunities for buildings workshop  

DOE Green Energy (OSTI)

Desiccant cooling and dehumidification technology is gaining acceptance as an option for air-conditioning buildings. Over the last few years, significant advances have been made in desiccant cooling and dehumidification in the private and public sectors. market penetration of desiccant systems in the past has been limited to unique applications. This workshop was an open forum for discussing these unique and potential applications. Workshop participants discussed the state of the art of desiccant materials, components, systems, and applications, both theoretically and experimentally. This document is a compilation of the papers presented in the workshop sessions.

Penney, T.R. (comp.)

1989-10-01T23:59:59.000Z

73

Analysis of the seasonal performance of hybrid desiccant cooling systems  

DOE Green Energy (OSTI)

A simulation model for the liquid desiccant component of a hybrid system was developed. An analysis of experimental test data was conducted. The liquid desiccant component was examined and the sensitivity of its seasonal performance to changes in principal component variables was identified. Seasonal simulations were performed on different operation modes of a hybrid liquid desiccant cooling system. The results were analyzed in terms of estimated operational costs and compared to the equivalent cost estimation of a conventional cooling system. The study showed that the investigated liquid desiccant configuration usually will not lower the costs of operation. A suggestion of an improved system is made.

Sick, F.

1987-04-01T23:59:59.000Z

74

Performance analysis of hybrid liquid desiccant solar cooling system.  

E-Print Network (OSTI)

??This thesis investigates the coefficient of performance (COP) of a hybrid liquid desiccant solar cooling system. This hybrid cooling system includes three sections: 1) conventional… (more)

Zhou, Zhipeng (Joe Zoe)

2009-01-01T23:59:59.000Z

75

Modeling and Simulation of a Solar Assisted Desiccant Cooling...  

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

system comprises a desiccant wheel containing Lithium Chloride in tandem with a rotating heat exchanger and two humidifiers on both supply and return air. The required...

76

Solar-Powered, Liquid-Desiccant Air Conditioner for Low-Electricity Humidity Control: Report and Summary Report  

DOE Green Energy (OSTI)

The primary objective of this project was to demonstrate the capabilities of a new high-performance, liquid-desiccant dedicated outdoor air system (DOAS) to enhance cooling efficiency and comfort in humid climates while substantially reducing electric peak demand at Tyndall Air Force Base (AFB), which is 12 miles east of Panama City, Florida.

Dean, J.; Kozubal, E.; Herrmann, L.; Miller, J.; Lowenstein, A.; Barker, G.; Slayzak, S.

2012-11-01T23:59:59.000Z

77

An assessment of desiccant cooling and dehumidification technology  

SciTech Connect

Desiccant systems are heat-actuated cooling and dehumidification technology. With the recent advances in this technology, desiccant systems can now achieve a primary energy coefficient of performance (COP) between 1.3 and 1.5, with potential to go to 1.7 and higher. It is becoming one of the most promising alternatives to conventional cooling systems. Two important and well-known advantages of desiccant cooling systems are that they are CFC free and they can reduce the electricity peak load. Another important but lesser-known advantage of desiccant technology is its potential for energy conservation. The energy impact study in this report indicated that a possible 13% energy saving in residential cooling and 8% in commercial cooling is possible. Great energy saving potential also exists in the industrial sector if industrial waste heat can be used for desiccant regeneration. The latest study on desiccant-integrated building heating, ventilating, and air conditioning (HVAC) systems indicated that the initial cost for the conventional cooling equipment was greatly reduced by using desiccant technology because of downsized compressors, fans, and ductworks. This cost reduction was more than enough to offset the cost of desiccant equipment. Besides, the system operation cost was also reduced. All these indicate that desiccant systems are also cost effective. This study provides an updated state-of-the-art assessment forsiccant technology in the field of desiccant materials, systems, computer models, and theoretical analyses. From this information the technology options were derived and the future research and development needs were identified. Because desiccant technology has already been applied in the commercial building sector with very encouraging results, it is expected that future market breakthroughs will probably start in this sector. A market analysis for the commercial building application is therefore included.

Mei, V.C.; Chen, F.C. [Oak Ridge National Lab., TN (United States); Lavan, Z. [Illinois Inst. of Tech., Chicago, IL (United States); Collier, R.K. Jr. [Collier Engineering Services, Merritt Island, FL (United States); Meckler, G. [Gershon Meckler Associates, P.C., Herndon, VA (United States)

1992-07-01T23:59:59.000Z

78

A desiccant dehumidifier for electric vehicle heating  

DOE Green Energy (OSTI)

Vehicle heating requires a substantial amount of energy. Engines in conventional cars produce enough waste heat to provide comfort heating and defogging/defrosting, even under very extreme conditions. Electric vehicles (EVs), however, generate little waste heat. Using battery energy for heating may consume a substantial fraction of the energy storage capacity, reducing the vehicle range, which is one of the most important parameters in determining EV acceptability. Water vapor generated by the vehicle passengers is in large part responsible for the high heating loads existing in vehicles. In cold climates, the generation of water vapor inside the car may result in water condensation on the windows, diminishing visibility. Two strategies are commonly used to avoid condensation on windows: windows are kept warm, and a large amount of ambient air is introduced in the vehicle. Either strategy results in a substantial heating load. These strategies are often used in combination, and a trade-off exists between them. If window temperature is decreased, ventilation rate has to be increased. Reducing the ventilation rate requires an increase of the temperature of the windows to prevent condensation. An alternative solution is a desiccant dehumidifier, which adsorbs water vapor generated by the passengers. Window temperatures and ventilation rates can then be reduced, resulting in a substantially lower heating load. This paper explores the dehumidifier heating concept. The first part shows the energy savings that could be obtained by using this technology. The second part specifies the required characteristics and dimensions of the system. The results indicate that the desiccant system can reduce the steady-state heating load by 60% or more under typical conditions. The reduction in heating load is such that waste heat may be enough to provide the required heating under most ambient conditions. Desiccant system dimensions and weight appear reasonable for packaging in an EV.

Aceves, S.M.; Smith, J.R.

1996-09-01T23:59:59.000Z

79

Advanced Desiccant Cooling and Dehumidification Program  

DOE Green Energy (OSTI)

The use of dessicant materials for cooling and dehumidification is an effective, economical, environmentally safe method for meeting indoor air quality standards established by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). To maximize the technology's potential for reducing energy consumption and improving indoor air quality, DOE established the Advanced Desiccant Cooling and Dehumidification Program. The National Renewable Energy Laboratory partners with industry to support and educate industry users, as well as to support technology transfer and benchmark current performance.

Slayzak, S.

1999-08-24T23:59:59.000Z

80

Modeling and Simulation of a Solar Assisted Desiccant Cooling System  

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

Modeling and Simulation of a Solar Assisted Desiccant Cooling System Modeling and Simulation of a Solar Assisted Desiccant Cooling System Speaker(s): Chadi Maalouf Date: December 2, 2004 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Peng Xu Increased living standards and high occupants comfort demands lead to a growth in air conditioning market. This results in high energy consumption and high CO2 emissions. For these reasons, the solar desiccant cooling system is proposed as an alternative to traditional air conditioning systems. This system comprises a desiccant wheel containing Lithium Chloride in tandem with a rotating heat exchanger and two humidifiers on both supply and return air. The required regeneration temperature for the desiccant wheel varies between 40oC and 70oC which makes possible the use

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

Investigation of manganese dioxide as an improved solid desiccant  

DOE Green Energy (OSTI)

This report describes the preparation of a series of manganese oxides and an analysis of their sorptive, structural, and surface characteristics as low-energetic desiccants for passive dehumidification and active desiccant cooling systems. A cusped Type III isotherm for the adsorption of water is reported for the first time. The data are interpreted as evidence of a first-order phase change from a two-dimensional gas to a liquid film in the first reversibly adsorbed layer. It appears that the water adsorption characteristics of MnO/sub 2/ compared to standard desiccants which exhibit Type II isotherms are due at least in part to differences in the physical topography and electronic properties of the desiccant substrates: MnO/sub 2/ is a p-type semiconductor with essentially-flat, monoenergetic surface structures, while standard desiccants like silica gel are electronic insulators with irregular, heteroenergetic surfaces.

Fraioli, A.V.

1983-03-01T23:59:59.000Z

82

Polymers as advanced materials for desiccant applications, 1988  

DOE Green Energy (OSTI)

This report documents work to identify a next-generation, low-cost material with which solar energy or heat from another low-cost energy source can be used for regenerating the water vapor sorption activity of the desiccant. The objective of the work is to determine how the desired sorption performance of advanced desiccant materials can be predicted by understanding the role of the material modifications and material surfaces. The work concentrates on solid materials to be used for desiccant cooling systems and which process water vapor in an atmosphere to produce cooling. The work involved preparing modifications of polystyrene sulfonic acid sodium salt, synthesizing a hydrogel, and evaluating the sorption performances of these and similar commercially available polymeric materials; all materials were studied for their potential application in solid commercial desiccant cooling systems. Background information is also provided on desiccant cooling systems and the role of a desiccant material within such a system, and it includes the use of polymers as desiccant materials. 31 refs., 16 figs., 5 tabs.

Czanderna, A.W.; Neidlinger, H.H.

1990-09-01T23:59:59.000Z

83

Analysis of advanced solar hybrid desiccant cooling systems for buildings  

DOE Green Energy (OSTI)

This report describes an assessment of the energy savings possible from developing hybrid desiccant/vapor-compression air conditioning systems. Recent advances in dehumidifier design for solar desiccant cooling systems have resulted in a dehumidifier with a low pressure drop and high efficiency in heat and mass transfer. A recent study on hybrid desiccant/vapor compression systems showed a 30%-80% savings in resource energy when compared with the best conventional systems with vapor compression. A system consisting of a dehumidifier with vapor compression subsystems in series was found to be the simplest and best overall performer.

Schlepp, D.; Schultz, K.

1984-10-01T23:59:59.000Z

84

Regeneration characteristics of adsorbent in the integrated desiccant/collector  

SciTech Connect

This study presents a solar desiccant system using an adsorbent in an integrated desiccant/solar collector that uses direct solar energy as a heat source for efficient regeneration of the adsorbent. The objective of this study is to investigate an integrated desiccant/collector in which the adsorbent absorbs solar radiation fully and is heated for regeneration. Another objective is to obtain the regeneration characteristics in the equipment proposed by both experiments and simulations. Throughout this study, silica gel is used as the adsorbent.

Saito, Y. (Osaka Inst. of Technology (Japan). Dept. of Mechanical Engineering)

1993-08-01T23:59:59.000Z

85

Efficiency of a liquid desiccant dehumidification system regenerated by using solar collectors/regenerators with photovoltaic fans  

Science Conference Proceedings (OSTI)

A hybrid solar dehumidification air-conditioning system was used to study the absorption of water vapor from moist air by contacting the air with aqueous solutions that contained from 90 to 94% triethylene glycol (TEG). For the packings of 2-inch polypropylene Jaeger Tri-Packs, which have a surface-to-volume ratio of 157 m{sup 2}/m{sup 3} (48 ft{sup 2}/ft{sup 3}), the efficiency of dehumidification can reach 93.3%. The environmental air was introduced into the dehumidifier cocurrently flowing with the liquid desiccant, and the liquid desiccant was sprayed on the top of the packing material. The air-to-liquid mass flow ratio was controlled in a range of 0.46 to 1.36. As the moisture was absorbed from air by the TEG solution, the solution was diluted. The regeneration of the solution was carried out in 20-piece (38.8 m{sup 2}) basin-type solar collectors/regenerators whose regeneration coefficients of performance are above 0.2. Air generated by photovoltaic fans was blown into the solar collectors/regenerators and carried away the water vapor from the evaporation of the aqueous desiccant solution. On the basis of the experimental results, the system performance is acceptable for most applications.

Tsair-Wang Chung; Wei-Yih Wu; Wen-Jih Yan; Ching-Lin Huang [Industrial Technology Research Institute, Taiwan (China)

1995-04-01T23:59:59.000Z

86

Design for a gas chromatograph for characterizing desiccant material  

DOE Green Energy (OSTI)

To characterize solar desiccant cooling materials, a gas chromatograph has been designed. The chromatograph can record breakthrough curves and equilibrium data under widely varying conditions so that the rates and heats of sorption may be determined. This information may then be used in analyzing models for the construction of desiccant cooling systems which use solar heating for the drying cycle. The effects of desiccant geometry upon bed packing are minimal. However, the effects of desiccant geometry upon the pressure differential across the bed and upon the rate controlling processes may be strong, and these must be investigated thoroughly. Ranges for flow rates and for control of the physical parameters have been selected to encompass those that may be encountered in practical systems. A list of equipment and materials of construction is presented together with a brief description of the operation of the equipment.

Pitts, R.; Czanderna, A.

1980-02-01T23:59:59.000Z

87

Development of a solar desiccant dehumidifier. Third technical progress report  

DOE Green Energy (OSTI)

This program is aimed at the development of a solar desiccant dehumidifier featuring a rotary bed of granular silica gel and a rotary regenerator. Design, fabrication, performance, commercialization studies, and test stand development are described in detail. (WHK)

Gunderson, M.E.

1979-06-12T23:59:59.000Z

88

Hydraulic conductivity of desiccated geosynthetic clay liners  

SciTech Connect

Large-scale tests were performed to determine the effect of a cycle of wetting and drying on the hydraulic conductivity of several geosynthetic clay liners (GCLs). The GCLs were covered with 0.6 m of pea gravel and permeated with water. After steady seepage had developed, the water was drained away, and the GCL was desiccated by circulating heated air through the overlying gravel. The drying caused severe cracking in the bentonite component of the GCLs. The GCLs were again permeated with water. As the cracked bentonite hydrated and swelled, the hydraulic conductivity slowly decreased from an initially high value. The long-term, steady value of hydraulic conductivity after the wetting and drying cycle was found to be essentially the same as the value for the undesiccated GCL. It is concluded that GCLs possess the ability to self-heal after a cycle of wetting and drying, which is important for applications in which there may be alternate wetting and drying of a hydraulic barrier (e.g. within a landfill final cover).

Boardman, B.T. [CH2M Hill, Oakland, CA (United States); Daniel, D.E. [Univ. of Texas, Austin, TX (United States)

1996-03-01T23:59:59.000Z

89

Energy Efficient, Evaporative Desalination Using ...  

Energy Efficient, Evaporative Desalination Using Superhydrophobic (SH) Technology Evaporative desalination is a simple and easy way to convert salt ...

90

Analysis of a Flat-Plate, Liquid-Desiccant, Dehumidifier and Regenerator.  

E-Print Network (OSTI)

??A numerical model for isothermal and non-isothermal flat-plate liquid-desiccant dehumidifiers and regenerators was developed and implemented. The two-dimensional model takes into account the desiccant, water… (more)

Mesquita, Lucio Cesar De Souza

2008-01-01T23:59:59.000Z

91

The Effects of Desiccation and Climatic Change on the Hydrology of the Aral Sea  

Science Conference Proceedings (OSTI)

Anthropogenic desiccation of the Aral Sea between 1960 and the mid-1990s resulted in a substantial modification of the land surface that changed air temperature in the surrounding region. During the desiccation interval, the net annual rate of ...

Eric E. Small; Filippo Giorgi; Lisa Cirbus Sloan; Steven Hostetler

2001-02-01T23:59:59.000Z

92

Zero Carryover Liquid-Desiccant Air Conditioner for Solar Applications: Preprint  

DOE Green Energy (OSTI)

A novel liquid-desiccant air conditioner that dries and cools building supply air will transform the use of direct-contact liquid-desiccant systems in HVAC applications, improving comfort, air quality, and providing energy-efficient humidity control.

Lowenstein, A.; Slayzak, S.; Kozubal, E.

2006-07-01T23:59:59.000Z

93

Performance predictions of silica-gel desiccant dehumidifiers  

DOE Green Energy (OSTI)

The analysis of a cross-cooled desiccant dehumidifier using silica gel in the form of sheets is described. This unit is the principal component of solar powered desiccant air conditioning system. The mathematical model has first been formulated describing the dynamics of the dehumidifier. The model leads to a system of nonlinear coupled heat and mass transfer equations for the sorption processes and linear heat transfer equations for the purging processes. The model accounts for the gas film resistance and for the moisture diffusion in the desiccant. The governing equations are solved by a finite difference scheme to obtain periodic steady state solutions. The accuracy of the theoretical predictions is ascertained by comparing them with the experimental results. The performance of the dehumidifier, for a chosen set of initial conditions and dehumidifier parameters, has also been given.

Mathiprakasam, B.; Lavan, Z.

1980-01-01T23:59:59.000Z

94

Advances in open-cycle solid desiccant cooling  

DOE Green Energy (OSTI)

Of the solar cooling options available open cycle solid desiccant cooling looks very promising. A brief review of the experimental and analytical efforts to date shows that within the last 10 years thermal performance has doubled. Research centers have been developed to explore new materials and geometry options and to improve and validate mathematical models that can be used by design engineers to develop new product lines. Typical results from the Solar Energy Research Institute's (SERI) Desiccant Cooling Research Program are shown. Innovative ideas for new cycles and spinoff benefits provide incentives to continue research in this promising field.

Penney, T.R.; Maclaine-cross, I.

1985-05-01T23:59:59.000Z

95

Dehumidification and simultaneous removal of selected pollutants from indoor air by a desiccant wheel using a 1M type desiccant  

SciTech Connect

Solid-desiccant dehumidifiers are increasingly becoming an integral part of desiccant based air-conditioning systems because of their effective handling of latent heat loads compared to conventional vapor compression units. In these units, either a silica gel or a molecular sieve is used for dehumidification of air. Both of them have the capability to co-adsorb various chemical pollutants during dehumidification of air. However, the shape of the isotherm for water vapor on these materials is not favorable for desiccant cooling applications. A mixture (1M desiccant) containing a silica gel, a molecular sieve, and a hydrophobic molecular sieve that was coated on an aluminum foil was studied for its capability for simultaneous removal of moisture and some selected pollutants from air. Experimental data were obtained in a fixed bed adsorber that simulated the operation of a rotary desiccant wheel. Air to be dehumidified and cleaned and the hot regeneration air were cycled in a specific time interval through this bed. The shape of the water isotherm on 1M desiccant was found to be in between that of silica gel and molecular sieve 13{times}, but its uptake capacity was significantly lower than that of either silica gel or molecular sieve. A flow rate of about 100 L/min that provided a face velocity of about 132 cm/s was used in the adsorption step. The flow rate during regeneration was about 50 L/min. The temperature of the inlet air was about 23 C and its relative humidity was varied between 20% and 80%. The concentrations of pollutants were as follows; carbon dioxide: 1050 and 2300 ppm; toluene: 32 ppm; 1,1,1-trichloroethane: 172 ppm, and formaldehyde: 0.35 ppm. A complete breakthrough of all the pollutants was observed during an adsorption cycle.

Popescu, M.; Ghosh, T.K. [Univ. of Missouri, Columbia, MO (United States)

1999-02-01T23:59:59.000Z

96

Conductive Thermal Interaction in Evaporative Cooling Process  

E-Print Network (OSTI)

It has long been recognized that evaporative cooling is an effective and logical substitute for mechanical cooling in hot-arid climates. This paper explores the application of evaporative coolers to the hot-humid climates using a controlled temperature of the incoming water. With exploitation of the effect of the thermal conduction between cool underground water and entering air, the performance of an evaporative cooler can be enhanced and its use in hot and moderately humid climates should also be considered. Usually the dry-bulb depression performed by an evaporative cooler depends solely on the ambient wet-bulb temperature. The cool underground water in an evaporative cooler can cause not only adiabatic evaporation but also sensible heat transfer between water and entering air for thermal comfort. This hybrid system outperforms the two-stage evaporative cooler without employing a complicated heat exchanger (indirect system), if the temperature of underground water is lower than the ambient wet-bulb temperature. Several areas in the southern hot-humid parts of the U.S. meet this condition.

Kim, B. S.; Degelman, L. O.

1990-01-01T23:59:59.000Z

97

Performance investigation on a novel two-stage solar driven rotary desiccant cooling system using composite desiccant materials  

Science Conference Proceedings (OSTI)

In this study, a two-stage solar driven rotary desiccant cooling (TSRDC) system with novel configuration and newly developed silica gel-haloid composite desiccant is proposed aiming to reduce regeneration temperature and to achieve high energy performance. Simulated results show that there also exists an optimal rotation speed for TSRDC system. Compared with one-stage system, it is found that for the similar supply air state, the required regeneration temperature of TSRDC system is lower and for the same regeneration temperature, the cooling capacity of TSRDC is bigger. (author)

Ge, T.S.; Li, Y.; Dai, Y.J.; Wang, R.Z. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200240 (China)

2010-02-15T23:59:59.000Z

98

Development of a solar desiccant dehumidifier. Second technical progress report  

SciTech Connect

Research and development of a solar desiccant dehumidifier featuring a rotary bed of granular silica gel and a rotary regenerator for air conditioning is described. The results of the system optimization studies are presented. The studies involved an extensive investigation of the energy saving potential and economic viability of the solar desiccant dehumidifier in different locations in the United States. Conventional electric vapor compression, and solar absorption and Rankine systems also were investigated for comparison. In general, it was found that the solar desiccant equipment, either by itself or in a hybrid system with an electric vapor compression air conditioner, is economically viable for all three locations considered. Substantial energy savings can be effected as well. Seal tests done at AiResearch to develop practical dynamic air seals are described. Leakage and friction tests were performed on a variety of material combinations and configurations. Dacron felt and silicone rubber were found to give an acceptable combination of leakage, friction, and cost characteristics. As part of the commercialization studies for the desiccant equipment, a questionnaire was sent to residential air conditioning equipment distributors. The results of the questionnaire are presented. The specifications and drawings for the 1.5-ton prototype are included. (WHK)

Gunderson, M.E.; Hwang, K.C.; Railing, S.M.; Rousseau, J.

1978-11-10T23:59:59.000Z

99

Energymaster Desiccant System Application to Light Commercial Buildings  

E-Print Network (OSTI)

Desiccant cooling systems offer unique advantages over conventional equipment in certain applications. AskCorp's Energymaster unit has been applied in several commercial situations where these advantages are most significant. The magnitude of operating cost savings and improved control is greatest in humid climates where both ambient enthalpy levels and space latent loads are highest.

Blanpied, M. C.; Coellner, J. A.; Macintosh, D. S.

1987-01-01T23:59:59.000Z

100

High-performance dehumidifier for solar desiccant cooling systems  

DOE Green Energy (OSTI)

An advanced-design, one-tenth-scale dehumidifier for use in residential solar desiccant-cooling systems has been built and tested. The new dehumidifier was designed using a parallel-passage geometry, where air flows through channels formed by walls coated with fine-ground silica gel desiccant. This concept has a high heat and mass transfer effectiveness and promises to double the coefficient of performance of the desiccant cooling system to 1.1 kW cooling output/kW thermal input. The parallel-passage design was found to have very low pressure drop, typically 20 Pa (.08 in. water) at design conditions. The low fan power required to drive such low pressure drop components indicates that electrical COP's in the range of 8.0 to 8.2 kW cooling output/kW electrical input are possible. Results presented include parametric studies of the effect of conditions such as temperature and humidity and design parameters such as desiccant particle size and channel spacing on dehumidifier performance.

Schlepp, D.

1983-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

Solar powered desiccant air conditioning system. Final report  

DOE Green Energy (OSTI)

A solar-powered desiccant air conditioning system using silica gel has been developed, and modifications to the existing unit and additional testing are proposed to demonstrate the feasibility of the unit. Conversion from a rotating bed to a fixed bed of silica gel is proposed. Some general plans for commercialization are briefly discussed. (LEW)

Not Available

1981-07-24T23:59:59.000Z

102

Use of unglazed transpired solar collectors for desiccant cooling  

SciTech Connect

The use of unglazed transpired solar collectors for desiccant regeneration in a solid desiccant cooling cycle was investigated because these collectors are less expensive than conventional glazed flat-plate collectors. Using computer models, we studied the performance of a desiccant cooling ventilation cycle integrated with either unglazed transpired collectors or conventional glazed flat-plate collectors. We found that the thermal coefficient of performance of the cooling system with unglazed collectors was lower than that of the cooling system with glazed collectors because the former system did not use the heat of adsorption released during the dehumidification process. Although the area required for the unglazed collector array was 70% more than that required for the glazed collector array in a 10.56 kW (3 ton) solar cooling system, the cost of the unglazed array was 45% less than the cost of the glazed array. The simple payback period of the unglazed collector was half of the payback period of the glazed collector when replacing an equivalent gas-fired air heater. Although the use of unglazed transpired collectors seems to make economic sense relative to use of glazed conventional collectors, some practical considerations may limit their use for desiccant regeneration.

Pesaran, A.A.; Wipke, K.B. (National Renewable Energy Lab., Golden, CO (United States))

1994-05-01T23:59:59.000Z

103

Facility design for cyclic testing of advanced solid desiccant dehumidifiers  

DOE Green Energy (OSTI)

The development of high performance components is required to reach the goal of desiccant cooling system cost-competitiveness with conventional vapor compensation air conditioning systems. SERI has designed a laminar flow, parallel passage dehumidifier that has this potential. The goal of SERI's desiccant cooling research program is to fully characterize experimentally the performance of the parallel passage dehumidifier under a wide range of operating conditions, investigate improvements in design, and verify existing models of dehumidifier performance against experimental results. This report documents the design of the SERI Desiccant Cooling Test Facility for performing the above testing. With slight modifications, the testing can be used for testing other desiccant cooling system components. The dehumidifier processes and the parameters and variables needed to control and characterize its performance are presented. The physical layout of the test loop and instrumentation for monitoring the operating conditions and dehumidifer performance and the controls for maintaining the operating conditions are specified. The computerized data acquisition system conversion equations and an error analysis of measurement variables are also presented.

Schlepp, D.; Schultz, K.; Zangrando, F.

1984-08-01T23:59:59.000Z

104

Evaporative Cooling | Open Energy Information  

Open Energy Info (EERE)

Evaporative Cooling Evaporative Cooling (Redirected from Hybrid Cooling) Jump to: navigation, search Dictionary.png Evaporative Cooling: An evaporative cooler is a device that cools air through the evaporation of water. Evaporative cooling works by employing water's large enthalpy of vaporization. The temperature of dry air can be dropped significantly through the phase transition of liquid water to water vapor (evaporation), which can cool air using much less energy than refrigeration. Evaporative cooling requires a water source, and must continually consume water to operate. Other definitions:Wikipedia Reegle Evaporative Cooling Evaporative Cooling Tower Diagram of Evaporative Cooling Tower Evaporative cooling technologies take advantage of both air and water to extract heat from a power plant. By utilizing both water and air one can

105

Indoor Humidity Analysis of an Integrated Radiant Cooling and Desiccant Ventilation System  

E-Print Network (OSTI)

Radiant cooling is credited with improving energy efficiency and enhancing the comfort level as an alternative method of space cooling in mild and dry climates, according to recent research. Since radiant cooling panels lack the capability to remove latent heat, they normally are used in conjunction with an independent ventilation system, which is capable of decoupling the space sensible and latent loads. Condensation concerns limit the application of radiant cooling. This paper studies the dehumidification processes of solid desiccant systems and investigates the factors that affect the humidity levels of a radiantly cooled space. Hourly indoor humidity is simulated at eight different operating conditions in a radiantly cooled test-bed office. The simulation results show that infiltration and ventilation flow rates are the main factors affecting indoor humidity level and energy consumption in a radiantly cooled space with relatively constant occupancy. It is found that condensation is hard to control in a leaky office operated with the required ventilation rate. Slightly pressurizing the space is recommended for radiant cooling. The energy consumption simulation shows that a passive desiccant wheel can recover about 50% of the ventilation load.

Gong, X.; Claridge, D. E.

2006-01-01T23:59:59.000Z

106

Soluble Substances and Evaporation  

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

Soluble Substances and Evaporation Soluble Substances and Evaporation Name: JD Status: student Grade: 9-12 Location: FL Country: New Zealand Date: Winter 2011-2012 Question: Do soluble substances evaporate with the water? Replies: JD, As a general rule, no. If the soluble substance is a solid, then its boiling point is well above that of water, so it cannot possibly boil off. If the substance is a liquid, it may have a boiling point that is below that of water and will boil off at a lower temperature than water. If the boiling point is higher than that of water, than it will boil off after the water has evaporated. Some substances, like ethanol for example, form an "azeotrope" with water. The combination of ethanol and water form a tight intermolecular connection that makes the two substances boil off at the same time.

107

Measure Guideline: Evaporative Condensers  

SciTech Connect

The purpose of this measure guideline on evaporative condensers is to provide information on a cost-effective solution for energy and demand savings in homes with cooling loads. This is a prescriptive approach that outlines selection criteria, design and installation procedures, and operation and maintenance best practices. This document has been prepared to provide a process for properly designing, installing, and maintaining evaporative condenser systems as well as understanding the benefits, costs, and tradeoffs.

German, A.; Dakin, B.; Hoeschele, M.

2012-03-01T23:59:59.000Z

108

Evaporative Cooling | Open Energy Information  

Open Energy Info (EERE)

Evaporative Cooling: Evaporative Cooling: An evaporative cooler is a device that cools air through the evaporation of water. Evaporative cooling works by employing water's large enthalpy of vaporization. The temperature of dry air can be dropped significantly through the phase transition of liquid water to water vapor (evaporation), which can cool air using much less energy than refrigeration. Evaporative cooling requires a water source, and must continually consume water to operate. Other definitions:Wikipedia Reegle Evaporative Cooling Evaporative Cooling Tower Diagram of Evaporative Cooling Tower Evaporative cooling technologies take advantage of both air and water to extract heat from a power plant. By utilizing both water and air one can reduce the amount of water required for a power plant as well as reduce the

109

Performance of a cross-cooled desiccant dehumidifier prototype  

DOE Green Energy (OSTI)

The cross-cooled dehumidifier prototype was constructed in the form of a cube with a side dimension of 0.6 m. The cross-cooling was achieved by passing air through rectangular channels perpendicular to process channels which are lined with desiccant sheets consisting of 9..mu..m Syloid 63/sup TM/ silica gel held in a Teflon web. The process for the manufacture of the silica gel sheets was developed at the Illinois Institute of Technology. The dehumidifier prototype was installed in a test system that simulated the performance of a cross-cooled desiccant cooling system and monitored the performance of the prototype. The dehumidifier prototype was operated over a wide range of operating conditions which would be typically encountered in the field installation of such a system. Variables measured were the moisture cycled, cooling capacity, total cooling capacity and coefficient of performance.

Worek, W.M.; Lavan, Z.

1981-08-01T23:59:59.000Z

110

Desiccant grain applied to the storage of solar drying potential  

Science Conference Proceedings (OSTI)

Sorption storage of solar heat using a layer of wheat as the desiccant was analyzed by means of a deep-bed model. Intended to be applied to solar-assisted in-storage drying of agricultural bulk materials, the probability of the persistence of unfavorable weather periods was quantified statistically for Potsdam for the month of August, as an example. Simulation results demonstrate that a relative humidity of the drying air of 65% can be maintained day and night for weeks without combustion of fossil fuels. Using a simple strategy of control, periods with insufficient solar radiation can be bridged over. The desiccant grain is not endangered by mold growth as a matter of principle. Simple solar air heaters can be used to avoid economic losses due to overdrying and to reduce the danger of decay to a minimum even at unfavorable climatic conditions.

Ziegler, T.; Richter, I.G.; Pecenka, R.

1999-09-01T23:59:59.000Z

111

Test and Evaluation of a Hybrid Desiccant Dehumidifier  

Science Conference Proceedings (OSTI)

Dehumidification technology is being investigated for potential savings in building air conditioning systems. The potential for savings lies in separating the sensible and the latent cooling loads to more efficiently address the combined conditioning needs of the space. The Munters DryCool HD combined desiccant/vapor compression system was tested in the EPRI Knoxville psychrometric chambers. The system was tested in the laboratory for a host of indoor and outdoor conditions. The system provides cooling a...

2011-05-09T23:59:59.000Z

112

Development of a laminar flow desiccant bed for solar air conditioning application  

DOE Green Energy (OSTI)

Mass transfer in silica gel beds of different configurations is reviewed in connection with use in the Solar-Desiccant-Evaporative Cooling System. A laminar flow, coated-sheet concept is proposed since it ensures a low pressure drop and minimal solid side mass transfer resistance. A preliminary bed design gives 1/3 the pressure drop of a previous packed particle bed design and a large reduction in volume and silica gel inventory. The construction of a packing module and test rig is described, and test results reported for a particle size of 0.12 mm (60 to 200 mesh) with a passage width of about 1.5 mm. In order to compare theory and experiment, an existing code, NUMINT, which solves the partial differential equations governing heat and mass transfer in silica gel beds, was revised to include the effects of substrate heat capacity, and non-adiabatic operation. Comparisons between theory and experiment were found to be generally satisfactory, though it was found that specification of the bed initial water content for adsorption tests presented some difficulties. The effect of solid side mass transfer resistance was found to be small, which suggests that an optimum design may incorporate a larger particle size. Topics for further work are suggested.

Kim, S.

1983-02-01T23:59:59.000Z

113

Analysis of a Fabric/Desiccant Window Cavity Dehumidifier  

E-Print Network (OSTI)

This paper presents the results of an exploratory study of a fabric/desiccant window cavity dehumidifier system for possible use in commercial buildings. The objective was to evaluate fabrics commonly used in buildings, and system concepts that employ these fabrics, which can be used to dehumidify room air. We developed a first-order energy/mass balance model to determine the performance of a window cavity dehumidifier that uses silica gel encapsulated in a fabric matrix rotating on a belt alternately through dehumidification and regeneration chambers; the modeling effort was supplemented by environmental chamber measurements of the moisture absorption characteristics of 16 fabric/desiccant combinations. We ran the model for a typical office building module, for outside air design conditions characteristic of the most difficult humidity regime in Texas. Two flow configurations, outside air and return air, were evaluated to determine the capability of such a system to dehumidify the air streams under consideration. Issues addressed included the physical limitations on the amount of desiccant that can be included in this configuration and the degree of dehumidification achievable.

Hunn, B. D.; Grasso, M. M.; Vadlamani, V.

1994-01-01T23:59:59.000Z

114

Development of an Energy Efficient Desiccant Dehumidifier : Final Report.  

SciTech Connect

Humidity control in space conditioning has received a good deal of attention in the past twenty or so years. Perhaps the most familiar application is the use of humidifiers in the winter months. Of equal concern is the use of air conditions and dehumidifiers in the summer months. High humidity levels in summer months require lower coil temperatures in order to achieve human comfort levels, and may result in significant product and property damage if humidity levels are not controlled at appropriate level. This study addresses the solid desiccant dehumidifier using IR heaters as an energy efficient desiccant dehumidifier (EEDD). The study is divided into two phases; Phase 1 -- Application assessment; and Phase 2: Prototype design, manufacture, and testing. Phase 1 addresses the total electrical energy usage by all possible applications of the EEDD and evaluates the energy performance of the EEDD in terms of its percentage energy savings compared to the conventional vapor compression cooling and also with the state-of-the-art desiccant dehumidifiers. During Phase 2, a functional EEDD prototype unit was designed and manufactured. The work of Phase 2 was divided into four tasks: Task 1, conceptual design; Task 2, mechanical (blueprint) design; Task 3, manufacture and factory testing; and Task 4, performance testing. 17 refs., 21 figs., 30 tabs.

Relwani, Suresh M.; Moschandreas, Demetrios J.

1990-04-01T23:59:59.000Z

115

Active Desiccant Dehumidification Module Integration with Rooftop Packaged HVAC  

Science Conference Proceedings (OSTI)

This report summarizes a research and development program that produced a stand-alone active desiccant module (ADM) that can be easily integrated with new or existing packaged cooling equipment. The program also produced a fully integrated hybrid system, combining the active desiccant section with a conventional direct expansion air-conditioning unit, that resulted in a compact, low-cost, energy-efficient end product. Based upon the results of this investigation, both systems were determined to be highly viable products for commercialization. Major challenges--including wheel development, compact packaging, regeneration burner development, control optimization, and low-cost design--were all successfully addressed by the final prototypes produced and tested as part of this program. Extensive laboratory testing was completed in the SEMCO laboratory for each of the two ADM system approaches. This testing confirmed the performance of the ADM systems to be attractive compared with that of alternate approaches currently used to precondition outdoor air, where a return air path is not readily available for passive desiccant recovery or where first cost is the primary design criterion. Photographs, schematics, and performance maps are provided for the ADM systems that were developed; and many of the control advantages are discussed. Based upon the positive results of this research and development program, field tests are under way for fully instrumented pilot installations of ADM systems in both a hotel/motel and a restaurant.

Fischer, J

2002-04-17T23:59:59.000Z

116

High performance solar desiccant cooling system: performance evaluations and research recommendations  

DOE Green Energy (OSTI)

This report presents an assessment of the current status of solar desiccant cooling and makes recommendations for continued research to develop high performance systems competitive with conventional cooling systems. Solid desiccant, liquid desiccant, and hybrid systems combining desiccant dehumidifiers with vapor compressor units are considered. Currently, all desiccant systems fall somewhat short of being competitive with conventional systems. Hybrid systems appear to have the greatest potential in the short term. Solid systems are close to meeting performance goals. Development of high performance solid desiccant dehumidifiers based on parallel passage designs should be pursued. Liquid system collector/generators and efficient absorbers should receive attention. Model development is also indicated. Continued development by hybrid systems is directly tied to the above work.

Schlepp, D.R.; Schultz, K.J.

1984-09-01T23:59:59.000Z

117

Hot air drum evaporator  

DOE Patents (OSTI)

An evaporation system for aqueous radioactive waste uses standard 30 and 55 gallon drums. Waste solutions form cascading water sprays as they pass over a number of trays arranged in a vertical stack within a drum. Hot dry air is circulated radially of the drum through the water sprays thereby removing water vapor. The system is encased in concrete to prevent exposure to radioactivity. The use of standard 30 and 55 gallon drums permits an inexpensive compact modular design that is readily disposable, thus eliminating maintenance and radiation build-up problems encountered with conventional evaporation systems.

Black, Roger L. (Idaho Falls, ID)

1981-01-01T23:59:59.000Z

118

Analysis of various designs of a desiccant wheel for improving the performance using a mathematical model  

Science Conference Proceedings (OSTI)

A mathematical model for predicting the performance of a desiccant wheel with various wheel designs has been used by considering heat and mass transfer for both moist air and the desiccant material. The model shows good agreement with experimental data. An experimental setup was fabricated using an evacuated tube solar air collector with a desiccant wheel. The hot air needed for regeneration is produced by the evacuated tube solar air collector

Avadhesh Yadav; V. K. Bajpai

2013-01-01T23:59:59.000Z

119

Method and composition for molding low density desiccant syntactic foam articles  

DOE Patents (OSTI)

A method and a composition are provided for molding low density desiccant syntactic foam articles. A low density molded desiccant article may be made as a syntactic foam by blending a thermosetting resin, microspheres and molecular sieve desiccant powder, molding and curing. Such articles have densities of 0.2-0.9 g/cc, moisture capacities of 1-12% by weight, and can serve as light weight structural supports.

Lula, James W. (Bonner Springs, KS); Schicker, James R. (Lee' s Summit, MO)

1984-01-01T23:59:59.000Z

120

On the use of the parabolic concentration profile assumption for a rotary desiccant dehumidifier  

SciTech Connect

The current work describes a model for a desiccant dehumidifier which uses a parabolic concentration profile assumption to model the diffusion resistance inside the desiccant particle. The relative merits of the parabolic concentration profile model compared with widely utilized rotary desiccant wheel models are discussed. The periodic steady-state parabolic concentration profile model developed is efficient and can accommodate a variety of materials. These features make it an excellent tool for design studies requiring repetitive desiccant wheel simulations. A quartic concentration profile assumption was also investigated which yielded a 2.8 percent average improvement in prediction error over the parabolic model.

Chant, E.E. [Univ. of Turabo, Gurabo (Puerto Rico); Jeter, S.M. [Georgia Inst. of Technology, Atlanta, GA (United States). George W. Woodruff School of Mechanical Engineering

1995-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

Evaporative Coolers | Department of Energy  

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

Evaporative Coolers Evaporative Coolers Evaporative Coolers July 1, 2012 - 6:51pm Addthis Evaporative Coolers, sometimes called swamp coolers, is another way to cool air in warm climates with low humidity. | Photo courtesy of Public Domain Photos. Evaporative Coolers, sometimes called swamp coolers, is another way to cool air in warm climates with low humidity. | Photo courtesy of Public Domain Photos. What does this mean for me? If you live in a warm, dry climate, you can save money on utility bills and stay comfortable during the cooling season by installing an evaporative cooler. Evaporative coolers add humidity to indoor air, a benefit in dry, warm climates. Unlike air conditioners that recirculate air, an evaporative cooler

122

Mapping evaporate minerals by ASTER  

Science Conference Proceedings (OSTI)

Evaporate minerals are important industrial raw materials that have been used in diverse industries for many years. As one of the most extensively used evaporate minerals, gypsum is an important raw material in the construction, agriculture, textile, ...

N. Serkan Oztan; M. Lutfi Suzen

2011-03-01T23:59:59.000Z

123

Falling film evaporator  

DOE Patents (OSTI)

A falling film evaporator including a vertically oriented pipe heated exteriorly by a steam jacket and interiorly by a finned steam tube, all heating surfaces of the pipe and steam tube being formed of a material wet by water such as stainless steel, and packing within the pipe consisting of Raschig rings formed of a material that is not wet by water such as polyvinylidene fluoride.

Bruns, Lester E. (Kennewick, WA)

1976-01-01T23:59:59.000Z

124

Schools resolve IAQ/humidity problems with desiccant preconditioning  

Science Conference Proceedings (OSTI)

This article describes how desiccant-based total energy recovery systems were retrofitted to the mechanical systems at Willis Foreman Elementary and Spirit Creek Middle Schools to decouple the outdoor air latent load from the existing 3-ton packaged rooftop HVAC units. The resulting hybrid system maintains 50 to 52 percent relative humidity in the space while continuously providing 15 cfm per student of outdoor air to the facility (a three-fold increase of the original 5 cfm per student design) and does so in a very energy-efficient manner.

Smith, J.C. [James C. Smith and Associates, Augusta, GA (United States)

1996-04-01T23:59:59.000Z

125

Preliminary study of the potential for performance improvements in solar desiccant cooling  

DOE Green Energy (OSTI)

The basic operation of the desiccant cooling system is reviewed, and a preliminary evaluation of the potential for improving desiccant cooling system performance to COPs of 1.0 to 1.2 is performed. A second-law thermodynamic system analysis was carried out, demonstrating that present desiccant systems only achieve 10% to 15% of theoretical maximum performance and that a large potential for improvement exists. Computer simulations have been used to study the effects of improving desiccant properties and increasing the effectiveness of some components of the system. Results have shown that modification of desiccant properties can only produce a limited (10%) increase in COP. Larger increases can be achieved by increasing the effectiveness of the sensible heat exchanger. However, this study indicates that the key to obtaining higher COPs is in the design of the dehumidifier. One design that shows promise is the parallel passage dehumidifier.

Schlepp, D.R.; Barlow, R.

1981-10-01T23:59:59.000Z

126

Dynamic performance characterization of bound, porous silica gel desiccant  

DOE Green Energy (OSTI)

Drying of air with silica gel is a well established procedure. However, for the specific use of silica gel in a novel desiccant air conditioning system, which continually cools the silica gel and utilizes solar energy for silica gel regeneration, conventional packed bed devices are not suitable. For this system to operate effectively the silica gel must not rise in its temperature or its capacity will be greatly diminished. Dynamic dehumidificatuion performance was investigted for a silica gel desiccant fabricated in bound, porous paper-like sheets. Sheets of various thickness (0.7 to 3 mm) were fabricated and tested under several dynamic flow conditions in a flat rectangular channel apparatus. During each experiment conditions of inlet moisture, air flowrate, and sheet temperature were maintained constant. Comparisons were also made with conventional silica gel pellets and with other forms of bound silica gel. The sheets show superior utilization of silica gel in short times (30 minutes or less). Tests were also made to examine the sheet structure in order to explore the effect of temperature on the porous structure, and to obtain pore size distributions.

Onischak, M.; Gidaspow, D.; Perkari, S.; Sasaki, T.

1979-10-01T23:59:59.000Z

127

Photovoltaic-electrodialysis regeneration method for liquid desiccant cooling system  

Science Conference Proceedings (OSTI)

Liquid desiccant cooling system (LDCS) is an (a novel) air-conditioning system with good energy saving potential. Regenerator is the power centre for LDCS. Currently, the regeneration process is always fuelled by thermal energy. Nevertheless, this regeneration pattern has some disadvantages in that its performance will become poor when the surrounding atmosphere is of high humidity, and the heat provided for regeneration will be unfavourable to the following dehumidification process. To ameliorate that, a new regeneration method is proposed in this paper: a membrane regenerator is employed to regenerate the liquid desiccant in an electrodialysis way; while solar photovoltaic generator is adopted to supply electric power for this process. Analysis has been made about this new regeneration method and the result reveals: this new manner achieves good stability with the immunity against the adverse impact from the outside high humidity; its performance is much higher than that of the thermal regeneration manner while putting aside the low efficiency of the photovoltaic system. Besides, purified water can be obtained in company with the regeneration process. (author)

Li, Xiu-Wei [College of Power Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Zhang, Xiao-Song [School of Energy and Environment, Southeast University, Nanjing 210096 (China)

2009-12-15T23:59:59.000Z

128

Simulations and economic analyses of desiccant cooling systems  

DOE Green Energy (OSTI)

The progress to date in the development and analysis of computer simulations of solar-powered desiccant cooling using an axial-flow disc-type dehumidifier wheel, solar-powered space heating, and electrically driven, standard vapor-compression air-conditioning systems for residential use is documented. Computer simulations for both solar and conventional heating and cooling systems were performed for 12-month heating and cooling seasons. Annual thermal performance and the resulting life cycle costs for both types of systems were analyzed and compared. The heating/cooling season simulations were run for five U.S. cities representing a wide range of climatic conditions and insolation. With the informaion resulting from these simulations, the optimum air-conditioning system was chosen to maximize the conservation of fossil fuels and minimize operating costs. Because of the increasing use of residential air conditioning employing electrically driven vapor-compression coolers, the five locations were studied to determine if it would be beneficial (in terms of both economics and fossil fuel displacement) to displace fossil-fuel-powered vapor-compression coolers and natural gas space heaters with solar-powered heating and desiccant cooling systems.

Shelpuk, B. C.; Hooker, D. W.; Jorgensen, G. J.; Bingham, C. E.

1979-06-01T23:59:59.000Z

129

Field-Scale Assessment of Desiccation Implementation for Deep Vadose Zone Contaminants  

Science Conference Proceedings (OSTI)

Desiccation of the vadose zone has the potential to reduce the flux of contaminants to underlying groundwater by removing moisture and decreasing the aqueous-phase permeability of the desiccated zone. However, data to evaluate implementation of desiccation are needed to enable consideration of desiccation as a potential remedy. Implementation of desiccation was field tested by injecting dry nitrogen gas to a target treatment zone and monitoring the spatial and temporal progress of the drying process. Aqueous waste discharges to disposal cribs approximately 50 years ago distributed water and contaminants, including primarily technetium-99 and nitrate, within the 100-m deep vadose zone at the test site. A field test location was selected adjacent to one of the former disposal cribs. The test was conducted in a contaminated portion of the vadose zone dominated by fine sands with lenses of silt material. Desiccation reduced volumetric moisture content to as low as 0.01. The lateral and vertical distribution of drying from the injection well was influenced by the subsurface heterogeneity. However, over time, desiccation occurred in the initially wetter, lower permeability lenses.

Truex, Michael J.; Oostrom, Martinus; Strickland, Christopher E.; Chronister, Glen B.; Benecke, Mark W.; Johnson, Christian D.

2012-11-01T23:59:59.000Z

130

Method and apparatus for extracting water from air using a desiccant  

DOE Patents (OSTI)

The present invention provides a method and apparatus for extracting liquid water from moist air using minimal energy input. The method can be considered as four phases: (1) adsorbing water from air into a desiccant, (2) isolating the water-laden desiccant from the air source, (3) desorbing water as vapor from the desiccant into a chamber, and (4) isolating the desiccant from the chamber, and compressing the vapor in the chamber to form liquid condensate. The liquid condensate can be removed for use. Careful design of the dead volumes and pressure balances can minimize the energy required. The dried air can be exchanged for fresh moist air and the process repeated. An apparatus comprises a first chamber in fluid communication with a desiccant, and having ports to intake moist air and exhaust dried air. The apparatus also comprises a second chamber in fluid communication with the desiccant. The second chamber allows variable internal pressure, and has a port for removal of liquid condensate. Each chamber can be configured to be isolated or in communication with the desiccant. The first chamber can be configured to be isolated or in communication with a course of moist air. Various arrangements of valves, pistons, and chambers are described.

Spletzer, Barry L. (Albuquerque, NM); Callow, Diane Schafer (Albuquerque, NM)

2003-01-01T23:59:59.000Z

131

Study of parameters affecting the performance of solar desiccant cooling systems  

DOE Green Energy (OSTI)

The performance of a solar desiccant cooling system depends on the performance of its components, particularly the desiccant dehumidifier and solar collectors. The desiccant dehumidifier performance is affected by the properties of the desiccant, particularly the shape of the isotherm and the regeneration temperature. The performance of a solar collector, as one would expect, depends on its operating temperature, which is very close to the desiccant regeneration temperature. The purpose of this study was to identify the desiccant isotherm shape (characterized by separation factor) that would result in the optimum performance - based on thermal coefficient of performance and cooling capacity - of a desiccant cooling cycle operating in ventilation mode. Different regeneration temperatures ranging from 65[degree]C to 160[degree]C were investigated to identify the corresponding optimum isotherm shape at each. Thermal COP dictates the required area of the solar collectors, and the cooling capacity is an indication of the size and cost of the cooling equipment. Staged and no-staged regeneration methods were studied.

Pesaran, A.A.; Hoo, E.A.

1993-01-01T23:59:59.000Z

132

Study of parameters affecting the performance of solar desiccant cooling systems  

DOE Green Energy (OSTI)

The performance of a solar desiccant cooling system depends on the performance of its components, particularly the desiccant dehumidifier and solar collectors. The desiccant dehumidifier performance is affected by the properties of the desiccant, particularly the shape of the isotherm and the regeneration temperature. The performance of a solar collector, as one would expect, depends on its operating temperature, which is very close to the desiccant regeneration temperature. The purpose of this study was to identify the desiccant isotherm shape (characterized by separation factor) that would result in the optimum performance - based on thermal coefficient of performance and cooling capacity - of a desiccant cooling cycle operating in ventilation mode. Different regeneration temperatures ranging from 65{degree}C to 160{degree}C were investigated to identify the corresponding optimum isotherm shape at each. Thermal COP dictates the required area of the solar collectors, and the cooling capacity is an indication of the size and cost of the cooling equipment. Staged and no-staged regeneration methods were studied.

Pesaran, A.A.; Hoo, E.A.

1993-01-01T23:59:59.000Z

133

#LabChat: Market Potential of Energy Efficient Technology, May...  

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

and effects of this advanced AC prototype in the video and Q&A: Lab Breakthrough: Desiccant Enhanced Evaporative Air Conditioning. This Office Hours tweetchat is part of...

134

Optimizing the performance of desiccant beds for solar-regenerated cooling  

DOE Green Energy (OSTI)

Detailed computer simulations as well as a simplified psychrometric analysis are used to determine the increase in cooling system performance that can be realized through the use of nonhomogeneous or staged desiccant beds. A staged bed of four hypothetical desiccants is shown to give a 10% higher cooling capacity than a silica gel bed of the same thickness. Alternatively, the same cooling capacity is produced by a staged bed 37% thinner than the silica gel bed. These effects could be employed to reduce the parasitic power requirements of desiccant cooling systems.

Barlow, R.; Collier, K.

1981-03-01T23:59:59.000Z

135

Laboratory and Modeling Evaluations in Support of Field Testing for Desiccation at the Hanford Site  

SciTech Connect

The Deep Vadose Zone Treatability Test Plan for the Hanford Central Plateau includes testing of the desiccation technology as a potential technology to be used in conjunction with surface infiltration control to limit the flux of technetium and other contaminants in the vadose zone to the groundwater. Laboratory and modeling efforts were conducted to investigate technical uncertainties related to the desiccation process and its impact on contaminant transport. This information is intended to support planning, operation, and interpretation of a field test for desiccation in the Hanford Central Plateau.

Truex, Michael J.; Oostrom, Martinus; Freedman, Vicky L.; Strickland, Christopher E.; Wietsma, Thomas W.; Tartakovsky, Guzel D.; Ward, Anderson L.

2011-02-23T23:59:59.000Z

136

Performance comparison of absorption and desiccant solar cooling systems  

DOE Green Energy (OSTI)

Cooling systems are required to operate over a wide range of outdoor and load conditions; however, the performance of solar cooling components is often specified and compared at a typical design point such as ARI conditions. A method is presented to directly compare the performance of different desiccant and absorption cooling systems by using psychrometric analysis of air distribution cycles under a range of outdoor conditions that systems encounter over a year. Using analysis of cooling load distributions for a small commercial office building in Miami and Phoenix a seasonal COP is calculated for each system. The heat input can be provided by solar or by an auxiliary heat source, such as natural gas.

Warren, M.L.; Wahlig, M.

1986-01-01T23:59:59.000Z

137

Heat and mass transfer analysis of a desiccant dehumidifier matrix  

DOE Green Energy (OSTI)

This report documents the SERI Single-Blow Test Facility's design, fabrication, and testing for characterizing desiccant dehumidifiers for solar cooling applications. The first test article, a silica-gel parallel-plate dehumidifier with highly uniform passages, was designed and fabricated. Transient heat and mass transfer data and pressure drop data across the dehumidifier were obtained. Available heat and mass transfer models were extended to the parallel-place geometry, and the experimental data were compared with model predictions. Pressure drop measurements were also compared with model predictions of the fully developed laminar flow theory. The comparisons between the lumped-capacitance model and the experimental data were satisfactory. The pressure drop data compared satisfactorily with the theory (within 15%). A solid-side resistance model that is more detailed and does not assume symmetrical diffusion in particles was recommended for performance. This study has increased our understanding of the heat and mass transfer in silica gel parallel-plate dehumidifiers.

Pesaran, A.A.

1986-07-01T23:59:59.000Z

138

Vacuum flash evaporated polymer composites  

DOE Patents (OSTI)

A method for fabrication of polymer composite layers in a vacuum is disclosed. More specifically, the method of dissolving salts in a monomer solution, vacuum flash evaporating the solution, condensing the flash evaporated solution as a liquid film, and forming the condensed liquid film into a polymer composite layer on a substrate is disclosed.

Affinito, John D. (Kennewick, WA); Gross, Mark E. (Pasco, WA)

1997-01-01T23:59:59.000Z

139

Desiccant-Based Combined Systems: Integrated Active Desiccant Rooftop Hybrid System Development and Testing Final Report- Phase 4  

SciTech Connect

This report summarizes the results of a research and development (R&D) program to design and optimize an active desiccant-vapor compression hybrid rooftop system. The primary objective was to combine the strengths of both technologies to produce a compact, high-performing, energy-efficient system that could accommodate any percentage of outdoor air and deliver essentially any required combination of temperature and humidity, or sensible heat ratio (SHR). In doing so, such a product would address the significant challenges imposed on the performance capabilities of conventional packaged rooftop equipment by standards 62 and 90.1 of the American Society of Heating, Refrigerating and Air-Conditioning Engineers. The body of work completed as part of this program built upon previous R&D efforts supported by the U.S. Department of Energy and summarized by the Phase 3b report ''Active Desiccant Dehumidification Module Integration with Rooftop Packaged HVAC Units'' (Fischer and Sand 2002), in addition to Fischer, Hallstrom, and Sand 2000; Fischer 2000; and Fischer and Sand 2004. All initial design objectives established for this development program were successfully achieved. The performance flexibility desired was accomplished by a down-sized active desiccant wheel that processes only a portion of the supply airflow, which is pre-conditioned by a novel vapor compression cycle. Variable-speed compressors are used to deliver the capacity control required by a system handling a high percentage of outdoor air. An integrated direct digital control system allows for control capabilities not generally offered by conventional packaged rooftop systems. A 3000-cfm prototype system was constructed and tested in the SEMCO engineering test laboratory in Columbia, MO, and was found to operate in an energy-efficient fashion relative to more conventional systems. Most important, the system offered the capability to independently control the supply air temperature and humidity content to provide individual sensible and latent loads required by an occupied space without over-cooling and reheating air. The product was developed using a housing construction similar to that of a conventional packaged rooftop unit. The resulting integrated active desiccant rooftop (IADR) is similar in size to a currently available conventional rooftop unit sized to provide an equivalent total cooling capacity. Unlike a conventional rooftop unit, the IADR can be operated as a dedicated outdoor air system processing 100% outdoor air, as well as a total conditioning system capable of handling any ratio of return air to outdoor air. As part of this R&D program, a detailed investigation compared the first cost and operating cost of the IADR with costs for a conventional packaged approach for an office building located in Jefferson City, MO. The results of this comparison suggest that the IADR approach, once commercialized, could be cost-competitive with existing technology--exhibiting a one-year to two-year payback period--while simultaneously offering improved humidity control, indoor air quality, and energy efficiency.

Fischer, J

2005-05-06T23:59:59.000Z

140

Overview of developing programs in solar desiccant cooling for residential buildings  

DOE Green Energy (OSTI)

An overview is provided of the ongoing work in desiccant cooling under the national solar heating and cooling research program. Open cycle adsorption and absorption systems are examined. The different dehumidifier bed configurations are the distinguishing features of these systems. The basic operating principles of each dehumidifier concept are explained along with some discussion of their comparative features. Performance predictions developed by SERI for a solar desiccant solar system employing an axial-flow desiccant wheel dehumidifier are presented. In terms of life-cycle cost and displaced fossil-fuel energy, the results indicate that it should be beneficial to use solar desiccant coolers in residential applications. Although no prototype testing of any of these concepts is currently underway, test results are expected and will be reported within one year.

Not Available

1979-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

Deep Vadose Zone Treatability Test for the Hanford Central Plateau: Soil Desiccation Pilot Test Results  

Science Conference Proceedings (OSTI)

This report describes results of a pilot test of soil desiccation conducted as part of the Deep Vadose Zone Treatability Test program. The report is written in CERCLA treatabilty test report format.

Truex, Michael J.; Oostrom, Martinus; Strickland, Christopher E.; Johnson, Timothy C.; Freedman, Vicky L.; Johnson, Christian D.; Greenwood, William J.; Ward, Anderson L.; Clayton, Ray E.; Lindberg, Michael J.; Peterson, John E.; Hubbard, Susan; Chronister, Glen B.; Benecke, Mark W.

2012-05-01T23:59:59.000Z

142

Experimental and Numerical Investigations of Soil Desiccation for Vadose Zone Remediation: Report for Fiscal Year 2007  

SciTech Connect

Apart from source excavation, the options available for the remediation of vadose zone metal and radionuclide contaminants beyond the practical excavation depth (0 to 15 m) are quite limited. Of the available technologies, very few are applicable to the deep vadose zone with the top-ranked candidate being soil desiccation. An expert panel review of the work on infiltration control and supplemental technologies identified a number of knowledge gaps that would need to be overcome before soil desiccation could be deployed. The report documents some of the research conducted in the last year to fill these knowledge gaps. This work included 1) performing intermediate-scale laboratory flow cell experiments to demonstrate the desiccation process, 2) implementing a scalable version of Subsurface Transport Over Multiple Phases–Water-Air-Energy (STOMP-WAE), and 3) performing numerical experiments to identify the factors controlling the performance of a desiccation system.

Ward, Andy L.; Oostrom, Mart; Bacon, Diana H.

2008-02-04T23:59:59.000Z

143

A desiccant/steam-injected gas-turbine industrial cogeneration system  

SciTech Connect

An integrated desiccant/steam-injected gas-turbine system was evaluated as an industrial cogenerator for the production of electricity and dry, heated air for product drying applications. The desiccant can be regenerated using the heated, compressed air leaving the compressor. The wet stream leaves the regenerator at a lower temperature than when it entered the desiccant regenerator, but with little loss of energy. The wet stream returns to the combustion chamber of the gas-turbine system after preheating by exchanging heat with the turbine exhaust strewn. Therefore, the desiccant is regenerated virtually energy-free. In the proposed system, the moisture-laden air exiting the desiccant is introduced into the combustion chamber of the gas-turbine power system. This paper discusses various possible design configurations, the impact of increased moisture content on the combustion process, the pressure drop across the desiccant regenerator, and the impact of these factors on the overall performance of the integrated system. A preliminary economic analysis including estimated potential energy savings when the system is used in several drying applications, and equipment and operating costs are also presented.

Jody, B.J.; Daniels, E.J.; Karvelas, D.E.; Teotia, A.P.S.

1993-12-31T23:59:59.000Z

144

A desiccant/steam-injected gas-turbine industrial cogeneration system  

SciTech Connect

An integrated desiccant/steam-injected gas-turbine system was evaluated as an industrial cogenerator for the production of electricity and dry, heated air for product drying applications. The desiccant can be regenerated using the heated, compressed air leaving the compressor. The wet stream leaves the regenerator at a lower temperature than when it entered the desiccant regenerator, but with little loss of energy. The wet stream returns to the combustion chamber of the gas-turbine system after preheating by exchanging heat with the turbine exhaust strewn. Therefore, the desiccant is regenerated virtually energy-free. In the proposed system, the moisture-laden air exiting the desiccant is introduced into the combustion chamber of the gas-turbine power system. This paper discusses various possible design configurations, the impact of increased moisture content on the combustion process, the pressure drop across the desiccant regenerator, and the impact of these factors on the overall performance of the integrated system. A preliminary economic analysis including estimated potential energy savings when the system is used in several drying applications, and equipment and operating costs are also presented.

Jody, B.J.; Daniels, E.J.; Karvelas, D.E.; Teotia, A.P.S.

1993-01-01T23:59:59.000Z

145

Experimental study of the heat and mass transfer in a packed bed liquid desiccant air dehumidifier  

Science Conference Proceedings (OSTI)

Desiccant cooling systems have the ability to provide efficient humidity and temperature control while reducing the electrical energy requirement for air conditioning as compared to a conventional system. Naturally, the desiccant air dehumidification process greatly influences the overall performance of the desiccant system. Therefore, the effects of variables such as air and desiccant flow rates, air temperature and humidity, desiccant temperature and concentration, and the area available for heat and mass transfer are of great interest. Due to the complexity of the dehumidification process, theoretical modeling relies heavily upon experimental studies. However, a limited number of experimental studies are reported in the literature. This paper presents results from a detailed experimental investigation of the heat and mass transfer between a liquid desiccant (triethylene glycol) and air in a packed bed absorption tower using high liquid flow rates. A high performance packing that combines good heat and mass transfer characteristics with low pressure drop is used. The rate of dehumidification, as well as the effectiveness of the dehumidification process are assessed based on the variables listed above. Good agreement is shown to exist between the experimental findings and predictions from finite difference modeling. In addition, a comparison between the findings in the present study and findings previously reported in the literature is made. The results obtained from this study make it possible to characterize the important variables which impact the system design.

Oeberg, V.; Goswami, D.Y. [Univ. of Florida, Gainesville, FL (United States)

1998-11-01T23:59:59.000Z

146

Method and composition for molding low-density desiccant syntactic-foam articles  

DOE Patents (OSTI)

These and other objects of the invention are achieved by a process for molding to size a desiccant syntactic foam article having a density of 0.2 to 0.9 g/cc and a moisture capacity of 1 to 12% by weight, comprising the steps of: charging a mold with a powdery mixture of an activated desiccant, microspheres and a thermosetting resin, the amount of the desiccant being sufficient to provide the required moisture capacity, and the amounts of the microspheres and resin being such that the microspheres/desiccant volume fraction exceeds the packing factor by an amount sufficient to substantially avoid shrinkage without causing excessively high molding pressures; covering the mold and heating the covered mold to a temperature and for an amount of time sufficient to melt the resin; and tightly closing the mold and heating the closed mold to a temperature and for an amount of time sufficient to cure the resin, and removing the resultant desiccant syntactic foam article from the mold. In a composition of matter aspect, the present invention provides desiccant syntactic foam articles, and a composition of matter for use in molding the same.

Not Available

1981-12-07T23:59:59.000Z

147

Research and development needs for desiccant cooling technology 1992--1997. (Supplement to the NREL report, Desiccant Cooling: State-of-the-Art Assessment)  

SciTech Connect

This report is a supplement to Desiccant Cooling: State-of-the-Art Assessment (NREL/TP-254-4147, DE93000013). In this supplement document we have described a detailed program assuming sufficient funding to implement the R&D activities needed. Desiccant dehumidification is a mature technology for industrial applications, and in recent years the technology has been used for air conditioning a number of institutional and commercial buildings. Our proposal is based on argumentative discussions at various national meetings with leaders of the technology. The goal is the penetration of the broad air conditioning market. This work is funded by the Buildings technology Office of the US Department of Energy.

Pesaran, A.A.

1992-12-01T23:59:59.000Z

148

Dual manifold heat pipe evaporator  

DOE Patents (OSTI)

An improved evaporator section is described for a dual manifold heat pipe. Both the upper and lower manifolds can have surfaces exposed to the heat source which evaporate the working fluid. The tubes in the tube bank between the manifolds have openings in their lower extensions into the lower manifold to provide for the transport of evaporated working fluid from the lower manifold into the tubes and from there on into the upper manifold and on to the condenser portion of the heat pipe. A wick structure lining the inner walls of the evaporator tubes extends into both the upper and lower manifolds. At least some of the tubes also have overflow tubes contained within them to carry condensed working fluid from the upper manifold to pass to the lower without spilling down the inside walls of the tubes. 1 figure.

Adkins, D.R.; Rawlinson, K.S.

1994-01-04T23:59:59.000Z

149

Dual manifold heat pipe evaporator  

DOE Patents (OSTI)

An improved evaporator section for a dual manifold heat pipe. Both the upper and lower manifolds can have surfaces exposed to the heat source which evaporate the working fluid. The tubes in the tube bank between the manifolds have openings in their lower extensions into the lower manifold to provide for the transport of evaporated working fluid from the lower manifold into the tubes and from there on into the upper manifold and on to the condenser portion of the heat pipe. A wick structure lining the inner walls of the evaporator tubes extends into both the upper and lower manifolds. At least some of the tubes also have overflow tubes contained within them to carry condensed working fluid from the upper manifold to pass to the lower without spilling down the inside walls of the tubes.

Adkins, Douglas R. (Albuquerque, NM); Rawlinson, K. Scott (Albuquerque, NM)

1994-01-01T23:59:59.000Z

150

Evaporative Cooling | Department of Energy  

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

cooler. In this example of an evaporative cooler, a small motor (top) drives a large fan (center) which blows air out the bottom and into your home. The fan sucks air in...

151

Laboratory And Field Investigations To Address Erosion, Volume Change And Desiccation Cracking Of Compost Amended Expansive Subsoils.  

E-Print Network (OSTI)

??Puppala, Anand Desiccations cracks are formed during drying process of fine grained cohesive soils in summer and these cracks often appear on unpaved subgrades due… (more)

Intharasombat, Napat

2007-01-01T23:59:59.000Z

152

Liquid-desiccant systems for cooling/drying applications  

SciTech Connect

Thermally-driven desiccant cooling systems have been investigated extensively during the past decade as economically competitive alternatives to vapor-compression cooling systems. A differential formulation is used to model the commercial Kathabar System to describe the heat and mass transfer for a control volume in both the conditioner and the generator. These differential equations depend on parameters, depending on the flow rate of the fluids (water, air and solution), the physical properties of these fluids, the geometry of the transfer surfaces and the heat and mass transfer coefficients. The flat-plate solar collector does not give a satisfactory results if it is used to heat the generator outlet water, because the water coming out from the generator is at about 80 C which is too high to be heated again by a flat-plate collector. The air coming from the conditioner is used for drying corn. The use of the Kathabar System for drying applications is infeasible. The Kathabar system mathematical model was modified by running the conditioner adiabatically. The governing equations became 4 first-order partial differential equations instead of 6 equations. The same numerical scheme is used to solve these equations. The air coming from the new system conditioner is used for drying corn.

Mahmoud, K.G.

1987-01-01T23:59:59.000Z

153

Evaporative Cooling Basics | Department of Energy  

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

Evaporative Cooling Basics Evaporative Cooling Basics Evaporative Cooling Basics August 16, 2013 - 1:53pm Addthis Evaporative cooling uses evaporated water to naturally and energy-efficiently cool. An illustration of an evaporative cooler. In this example of an evaporative cooler, a small motor (top) drives a large fan (center) which blows air out the bottom and into your home. The fan sucks air in through the louvers around the box, which are covered with water-saturated absorbent material. How Evaporative Coolers Work There are two types of evaporative coolers: direct and indirect. Direct evaporative coolers, also called swamp coolers, work by cooling outdoor air by passing it over water-saturated pads, causing the water to evaporate into it. The 15°-40°F-cooler air is then directed into the home

154

Evaporative Cooling Basics | Department of Energy  

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

Evaporative Cooling Basics Evaporative Cooling Basics Evaporative Cooling Basics August 16, 2013 - 1:53pm Addthis Evaporative cooling uses evaporated water to naturally and energy-efficiently cool. An illustration of an evaporative cooler. In this example of an evaporative cooler, a small motor (top) drives a large fan (center) which blows air out the bottom and into your home. The fan sucks air in through the louvers around the box, which are covered with water-saturated absorbent material. How Evaporative Coolers Work There are two types of evaporative coolers: direct and indirect. Direct evaporative coolers, also called swamp coolers, work by cooling outdoor air by passing it over water-saturated pads, causing the water to evaporate into it. The 15°-40°F-cooler air is then directed into the home

155

Method and apparatus for flash evaporation of liquids  

DOE Patents (OSTI)

A vertical tube flash evaporator for introducing a superheated liquid into a flash evaporation chamber includes a vertical inlet tube with a flared diffuser portion at its upper outlet end. A plurality of annular screens are positioned in axially spaced-apart relation to each other around the periphery of the vertical tube and below the diffuser portion thereof. The screens are preferably curved upward in a cup-shaped configuration. These flash evaporators are shown in an ocean thermal energy conversion unit designed for generating electric power from differential temperature gradients in ocean water. The method of use of the flash evaporators of this invention includes flowing liquid upwardly through the vertical tube into the diffuser where initial expansion and boiling occurs quite violently and explosively. Unvaporized liquid sheets and drops collide with each other to enhance surface renewal and evaporation properties, and liquid flowing over the outlet end of the diffuser falls onto the curved screens for further surface renewal and evaporation.

Bharathan, Desikan (Lakewood, CO)

1984-01-01T23:59:59.000Z

156

Method and apparatus for flash evaporation of liquids  

DOE Patents (OSTI)

A vertical tube flash evaporator for introducing a super-heated liquid into a flash evaporation chamber includes a vertical inlet tube with a flared diffuser portion at its upper outlet end. A plurality of annular screens are positioned in axially spaced-apart relation to each other around the periphery of the vertical tube and below the diffuser portion thereof. The screens are preferably curved upward in a cup-shaped configuration. These flash evaporators are shown in an ocean thermal energy conversion unit designed for generating electric power from differential temperature gradients in ocean water. The method of use of the flash evaporators of this invention includes flowing liquid upwardly through the vertical tube into the diffuser where initial expansion and boiling occurs quite violently and explosively. Unvaporized liquid sheets and drops collide with each other to enhance surface renewal and evaporation properties, and liquid flowing over the outlet end of the diffuser falls onto the curved screens for further surface renewal and evaporation.

Bharathan, D.

1984-01-01T23:59:59.000Z

157

SOIL DESICCATION TECHNIQUES STRATEGIES FOR IMMOBILIZATION OF DEEP VADOSE CONTAMINANTS AT THE HANFORD CENTRAL PLATEAU  

SciTech Connect

Deep vadose zone contamination poses some of the most difficult remediation challenges for the protection of groundwater at the Hanford Site where processes and technologies are being developed and tested for use in the on-going effort to remediate mobile contamination in the deep vadose zone, the area deep beneath the surface. Historically, contaminants were discharged to the soil along with significant amounts of water, which continues to drive contaminants deeper in the vadose zone toward groundwater. Soil desiccation is a potential in situ remedial technology well suited for the arid conditions and the thick vadose zone at the Hanford Site. Desiccation techniques could reduce the advance of contaminants by removing the pore water to slow the rate of contaminants movement toward groundwater. Desiccation technologies have the potential to halt or slow the advance of contaminants in unsaturated systems, as well as aid in reduction of contaminants from these same areas. Besides reducing the water flux, desiccation also establishes capillary breaks that would require extensive rewetting to resume pore water transport. More importantly, these techniques have widespread application, whether the need is to isolate radio nuclides or address chemical contaminant issues. Three different desiccation techniques are currently being studied at Hanford.

BENECKE MW; CHRONISTER GB; TRUEX MJ

2012-01-30T23:59:59.000Z

158

Performance characteristics of open-flow liquid desiccant solar collector/regenerator for solar cooling applications. Part 2. System simulation and performance measurements. Final report  

DOE Green Energy (OSTI)

This research focussed on the performance and system simulation of an open-flow liquid desiccant solar collector/regenerator.

Wood, B.D.; Siebe, D.A.; Applebaum, M.A.; Novak, K.S.; Ballew, L.M.

1983-11-01T23:59:59.000Z

159

Improving Gas-Fired Heat Pump Capacity and Performance by Adding a Desiccant Dehumidification Subsystem  

E-Print Network (OSTI)

This paper examines the merits of coupling a desiccant dehumidification subsystem to a gas-engine- driven vapor compression air conditioner. A system is identified that uses a rotary, silica gel, parallel-plate dehumidifier. Dehumidifier data and analysis are based on recent tests. The dehumidification subsystem processes the fresh air portion and handles the latent portion of the load. Adding the desiccant subsystem increases the gas-based coefficient of performance 40% and increases the cooling capacity 50%. Increased initial manufacturing costs are estimated at around $500/ton ($142/kW) for volume production. This cost Level is expected to reduce the total initial cost per ton compared to a system without the desiccant subsystem.

Parsons, B. K.; Pesaran, A. A.; Bharathan, D.; Shelpuk, B. C.

1990-01-01T23:59:59.000Z

160

Performance predictions of silica-gel desiccant dehumidifiers. Technical report No. 3  

SciTech Connect

The analysis of a cross-cooled desiccant dehumidifier using silica gel in the form of sheets is described. This unit is the principal component of solar powered desiccant air conditioning system. The mathematical model has first been formulated describing the dynamics of the dehumidifier. The model leads to a system of nonlinear coupled heat and mass transfer equations for the sorption processes and linear heat transfer equations for the purging processes. The model accounts for the gas film resistance and for the moisture diffusion in the desiccant. The governing equations are solved by a finite difference scheme to obtain periodic steady state solutions. The accuracy of the theoretical predictions is ascertained by comparing them with the experimental results. The performance of the dehumidifier, for a chosen set of initial conditions and dehumidifier parameters, has also been given.

Mathiprakasam, B.; Lavan, Z.

1980-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

Contract No. EG-77-C-01-4042OPTIMIZING 'l%E PERFORWANCE OF DESICCANT BEDS FOB SOLAR RJXENEXATED COOLING  

E-Print Network (OSTI)

Lavan and Lunde have recognized this problem and have advocated nonadiabatic drying of the air; Lavan (4) investigating a crosscooled desiccant bed, and Lunde (5> propos-Ing a series of desiccant beds and heat exchangers. The purpose in both concepts is to keep the temperature of the silica gel low during adsorption so that the moisture capacity remains high. 1.

Kirk Collier; Robert Barlow; Kirk Collier

1981-01-01T23:59:59.000Z

162

Indirect evaporative cooling in retail  

Science Conference Proceedings (OSTI)

JCPenney Co., Inc., recently opened a 126,000-sq ft, two-level retail store in Albuquerque, NM. The project construction was accomplished using a design-build format. This process allows preliminary construction processes to begin while the design is finalized. Law/Kingdom, Inc. was assigned the architectural and engineering services for this building. During the process of design, the team decided to study the addition of evaporative cooling into the air system. This article reviews system design, selection, and performance using an indirect evaporative system in the HVAC system. It also demonstrates the company`s design approach on the original equipment selection for a typical anchor store.

Bartlett, T.A. [JCPenney Co., Plano, TX (United States)

1996-12-01T23:59:59.000Z

163

Desiccant solar air conditioning in tropical climates: II-field testing in Guadeloupe  

Science Conference Proceedings (OSTI)

This paper presents the results of the experimental investigation of a solar desiccant air conditioning device exposed to the sun in Guadeloupe to test that adaptability of a silicagel compact bed, the most simple technology, in a tropical climate. It has been shown that it is possible to make use of solar flat plate collectors with a balancing water tank, to produce heat for the regeneration of a solid desiccant as silicagel, with solar energy. Second, the compact bed system proposed gives the foreseen cooling power, but considerable losses appear, particularly in the sorption process, which is not close enough to the reversible adiabatic one.

Dupont, M.; Celestine, B.; Beghin, B. (Solar Energy Lab., Pointe-a-Pitre (Guadeloupe))

1994-06-01T23:59:59.000Z

164

Modeling of solid-side mass transfer in desiccant particle beds  

DOE Green Energy (OSTI)

A model is proposed for heat and mass transfer in a packed bed of desiccant particles and accounts for both Knudsen and surface diffusion within the particles. Using the model, predictions are made for the response of thin beds of silica gel particles to a step change in air inlet conditions compared to mental results. The predictions are found to be satisfactory and, in general, superior to those of pseudogas-side controlled models commonly used for the design of desiccant dehumidifiers for solar air conditioning application.

Pesaran, A.A.; Mills, A.F.

1984-02-01T23:59:59.000Z

165

Research and development needs for desiccant cooling technology 1992--1997  

SciTech Connect

This report is a supplement to Desiccant Cooling: State-of-the-Art Assessment (NREL/TP-254-4147, DE93000013). In this supplement document we have described a detailed program assuming sufficient funding to implement the R D activities needed. Desiccant dehumidification is a mature technology for industrial applications, and in recent years the technology has been used for air conditioning a number of institutional and commercial buildings. Our proposal is based on argumentative discussions at various national meetings with leaders of the technology. The goal is the penetration of the broad air conditioning market. This work is funded by the Buildings technology Office of the US Department of Energy.

Pesaran, A.A.

1992-12-01T23:59:59.000Z

166

Practical Estimates of Lake Evaporation  

Science Conference Proceedings (OSTI)

Practical estimates of lake evaporation must rely on data that can be observed in the land environment. This requires the ability to take into account the changes in the temperature and humidity that occur when the air passes from the land to the ...

F. I. Morton

1986-03-01T23:59:59.000Z

167

Upward-facing Lithium Flash Evaporator for NSTX-U  

SciTech Connect

NSTX plasma performance has been significantly enhanced by lithium conditioning [1]. To date, the lower divertor and passive plates have been conditioned by downward facing lithium evaporators (LITER) as appropriate for lower null plasmas. The higher power operation expected from NSTX-U requires double null plasma operation in order to distribute the heat flux between the upper and lower divertors making it desirable to coat the upper divertor region with Li as well. An upward aiming LITER (U-LITER) is presently under development and will be inserted into NSTX-U using a horizontal probe drive located in a 6" upper midplane port. In the retracted position the evaporator will be loaded with up to 300 mg of Li granules utilizing one of the calibrated NSTX Li powder droppers[2]. The evaporator will then be inserted into the vessel in a location within the shadow of the RF limiters and will remain in the vessel during the discharge. About 10 seconds before a discharge, it will be rapidly heated and the lithium completely evaporated onto the upper divertor, thus avoiding the complication of a shutter that prevents evaporation during the shot when the diagnostic shutters are open. The minimal time interval between the evaporation and the start of the discharge will avoid the passivation of the lithium by residual gases and enable the study of the conditioning effects of un-passivated Li surfaces [3]. Two methods are being investigated to accomplish the rapid (few second) heating of the lithium. A resistive method relies on passing a large current through a Li filled crucible. A second method requires using a 3 kW e-beam gun to heat the Li. In this paper the evaporator systems will be described and the pros and cons of each heating method will be discussed.

Roquemore, A. L.

2013-07-09T23:59:59.000Z

168

Cryptic species within the cosmopolitan desiccation-tolerant moss Grimmia laevigata  

E-Print Network (OSTI)

Cryptic species within the cosmopolitan desiccation-tolerant moss Grimmia laevigata Catherine C cosmopolitan range. This presents an evolutionary puz- zle, the solution to which lies in understanding phylogeography The broad and, in some cases, cosmopolitan distribution of many moss species suggests

Thompson, John N.

169

Analysis and comparison of active solar desiccant and absorption cooling systems. Part 1; Model description  

DOE Green Energy (OSTI)

A comparative analysis has been performed to compare the cooling and dehumidification performance of future ventilation-mode desiccant systems, proposed advanced absorption systems, and conventional vapor compression systems. A common framework has been developed for direct comparison of these different cooling technologies; this method is described in this paper.

Warren, M.L. (ASI Controls, San Ramon, CA (US)); Wahlig, M. (Lawrence Berkeley Lab., CA (USA). Applied Science Div.)

1991-02-01T23:59:59.000Z

170

Sensor and numerical simulator evaluation for porous medium desiccation and rewetting at the intermediate laboratory scale  

Science Conference Proceedings (OSTI)

Soil desiccation, in conjunction with surface infiltration control, is considered at the Hanford Site as a potential technology to limit the flux of technetium and other contaminants in the vadose zone to the groundwater. An intermediate-scale experiment was conducted to test the response of a series of instruments to desiccation and subsequent rewetting of porous media. The instruments include thermistors, thermocouple psychrometers, dual-probe heat pulse sensors, heat dissipation units, and humidity probes. The experiment was simulated with the multifluid flow simulator STOMP, using independently obtained hydraulic and thermal porous medium properties. All instrument types used for this experiment were able to indicate when the desiccation front passed a certain location. In most cases the changes were sharp, indicating rapid changes in moisture content, water potential, or humidity. However, a response to the changing conditions was recorded only when the drying front was very close to a sensor. Of the tested instruments, only the heat dissipation unit and humidity probes were able to detect rewetting. The numerical simulation results reasonably match the experimental data, indicating that the simulator captures the pertinent gas flow and transport processes related to desiccation and rewetting and may be useful in the design and analysis of field tests.

Oostrom, Martinus; Wietsma, Thomas W.; Strickland, Christopher E.; Freedman, Vicky L.; Truex, Michael J.

2012-02-01T23:59:59.000Z

171

Definition: Evaporative Cooling | Open Energy Information  

Open Energy Info (EERE)

Evaporative Cooling An evaporative cooler is a device that cools air through the evaporation of water. Evaporative cooling works by employing water's large enthalpy of vaporization. The temperature of dry air can be dropped significantly through the phase transition of liquid water to water vapor (evaporation), which can cool air using much less energy than refrigeration. Evaporative cooling requires a water source, and must continually consume water to operate.[1] References ↑ http://en.wikipedia.org/wiki/Evaporative_cooler Ret LikeLike UnlikeLike You like this.Sign Up to see what your friends like. rieved from "http://en.openei.org/w/index.php?title=Definition:Evaporative_Cooling&oldid=601323" Category: Definitions What links here Related changes

172

Sorption and desorption characteristics of a packed bed of clay-CaCl{sub 2} desiccant particles  

Science Conference Proceedings (OSTI)

Desiccants can be used in conjunction with solar energy to provide a viable alternative to traditional air conditioning techniques. A desiccant consisting of clay and calcium chloride was developed and tested using multiple sorption and desorption cycles. During sorption, inlet air temperatures from 23 to 36 C with corresponding relative humidities of 42-66% were tested. Additionally, superficial air velocities from 0.17 to 0.85 m/s were tested. During desorption, inlet air temperatures from 50 to 57 C and superficial air velocities of approximately 0.30 and 0.60 m/s were tested. A regression equation was determined for the mass of water sorbed by the clay-CaCl2 desiccant with a R{sup 2} value of 0.917. The desorption data was regressed to an exponential function and significant k-values were determined. An equation for pressure drop through the desiccant was determined and compared to existing models. The desiccant was found to perform well during the repeated test cycles though small masses of desiccant were lost due to surface disintegration of the desiccant spheres. (author)

Tretiak, C.S.; Abdallah, N. Ben [Department of Process Engineering and Applied Science, Dalhousie University, P.O. Box 1000, Halifax, Nova Scotia (Canada)

2009-10-15T23:59:59.000Z

173

Iodine retention during evaporative volume reduction  

DOE Patents (OSTI)

An improved method for retaining radioactive iodine in aqueous waste solutions during volume reduction is disclosed. The method applies to evaporative volume reduction processes whereby the decontaminated (evaporated) water can be returned safely to the environment. The method generally comprises isotopically diluting the waste solution with a nonradioactive iodide and maintaining the solution at a high pH during evaporation.

Godbee, H.W.; Cathers, G.I.; Blanco, R.E.

1975-11-18T23:59:59.000Z

174

Direct numerical simulation of evaporating droplets  

Science Conference Proceedings (OSTI)

A model for the three-dimensional direct numerical simulation of evaporating, deforming droplets in incompressible flow is presented. It is based on the volume-of-fluid method and is therefore capable of capturing very strong deformations. The evaporation ... Keywords: DNS, Deformed droplets, Evaporation, Multiphase flow, Stefan flow, VOF

Jan Schlottke; Bernhard Weigand

2008-05-01T23:59:59.000Z

175

Evaporation  

E-Print Network (OSTI)

• The Office of Science (SC) is the single largest supporter of basic research in the physical sciences in the United States, … providing more than 40 percent of total funding … for the Nation’s research programs in high-energy physics, nuclear physics, and fusion energy sciences.

An Esnet Perspective; Joint Techs; William E. Johnston; Esnet Department Head; Senior Scientist; Snow Melt

2007-01-01T23:59:59.000Z

176

Diffusion-Controlled Evaporating Completely Wetting Meniscus in a Channel  

E-Print Network (OSTI)

coefficient of grooved heat pipe evaporator walls. ’ Int. J.ranging from micro heat pipes to grooved evaporators. In

Njante, Jean-Pierre

2012-01-01T23:59:59.000Z

177

Micro loop heat pipe evaporator coherent pore structures  

E-Print Network (OSTI)

Loop heat pipes seem a promising approach for application in modern technologies where such thermal devices as cooling fans and radiators cannot satisfy overall requirements. Even though a loop heat pipe has a big potential to remove the thermal energy from a high heat flux source, the heat removal performance of heat pipes cannot be predicted well since a first principles of evaporation has not been established. An evaporation model based on statistical rate theory has been recently suggested by Ward and developed for a single pore by Oinuma. A loop heat pipe with coherent pore wick structure has been proposed as a design model. To limit product development risk and to enhance performance assurance, design model features and performance parameters have been carefully reviewed during the concept development phase and have been deliberately selected so as to be well-founded on the limited existing loop heat pipe knowledge base. A first principles evaporation model has been applied for evaporator geometry optimization. A number of iteration calculations have been performed to satisfy design and operating limitations. A set of recommendations for design optimization has been formulated. An optimal model has been found and proposed for manufacture and experimental investigation.

Alexseev, Alexandre Viktorovich

2003-08-01T23:59:59.000Z

178

Experimental Investigation on the Operation Performance of a Liquid Desiccant Air-conditioning System  

E-Print Network (OSTI)

A large share of energy consumption is taken by an air-conditioning system. It worsens the electricity load of the power network. Therefore, more and more scholars are paying attention to research on new types of air-conditioning systems that are energy- saving and environment-friendly. A liquid desiccant air conditioning system is among them, as it has a tremendous ability for power storage and low requirements for heat resources. Heat with low temperatures, such as excess heat, waste heat, and solar power, is suitable for the liquid desiccant air-conditioning system. The feasibility and economical efficiency of the system are studied in this experimental research. The result shows that when the temperature of the regeneration is about 80?, the thermodynamic coefficient of the system is about 0.6, and the supply air temperature of the air-conditioning system remains stable at 21?, the air-conditioning system can meet human comfort levels.

Liu, J.; Wang, J.; Wu, Z.; Gu, W.; Zhang, G.

2006-01-01T23:59:59.000Z

179

Development of a solar-desiccant dehumidifier. Phase II second technical progress report  

DOE Green Energy (OSTI)

The solar desiccant air conditioner (SODAC) system and its operation are described, including the characteristics of the major components, the performance at design conditions, and the control schemes for optimum operation in various climates. The system uses granular silica gel as a desiccant. It may operate in either a recirculated mode (no air exchange between the outside and the conditioned space) or a ventilated mode (air exchanged between outside and conditioned space). The test data in the ventilated mode at design flow rates are presented. Data include outdoor and indoor inlet wet and dry bulb temperatures, indoor outlet dry and wet bulb temperatures, capacity, coefficient of performance, air flow rates, hot water temperature, and solar heat used. The effects of indoor, outdoor, and hot water temperatures on the capacity and coefficient of performance are shown graphically, and the recirculated and ventilated modes, performances are compared. (LEW)

Rousseau, J.

1981-10-16T23:59:59.000Z

180

Comparison of the performance of open cycle air conditioners utilizing rotary desiccant dehumidifiers  

DOE Green Energy (OSTI)

This paper presents the results of an investigation of open cycle cooling systems using rotary desiccant dehumidifiers. Three systems, the ventilation, recirculation, and Dunkle cycles have been modeled. The performance of these systems coupled with an air-based solar system has been determined using TRNSYS simulations of system operation in four representative US climates. The system COP, fraction of the total cooling load met by the desiccant system, and fraction of the thermal energy provided by solar energy are compared. An assessment of the effect of climate and system parameters on the relative performance of the three system configurations is made. It is shown that in order to meet residential loads of 7 to 11 kW with a COP on the order of unity, systems with high effectiveness must be employed. These systems were also found to perform well when operated solely with a solar thermal input.

Jurinak, J.J.; Beckman, W.A.

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

Experimental performance verification of a coil-type liquid desiccant system at part-load operation  

SciTech Connect

An experimental study was conducted to compare the predicted performance of a commercially available coil type liquid desiccant cooling and dehumidification system with the experimental results at part-load conditions. A mathematical model was used to predict the performance of coil type liquid desiccant system. This model was based mostly on the manufacturer's catalog data. The coil type system used in the experimental study was a system manufactured in the US. The system is commercially available as 200-10 KXCb, 10-row deep conditioner unit with a design air flow rate of 1180 1/s(2500 scfm). For regeneration of the solution, a packed type 3.0-P regenerator unit with a design air flow rate of 448.4 1/s(950 scfm) was used.

Khan, A.Y. (Univ. of Puerto Rico, Mayaguez (Puerto Rico)); Ball, H.D. (Kansas State Univ., Manhattan, KS (United States))

1993-11-01T23:59:59.000Z

182

Development of a solar-desiccant dehumidifier. Phase II. Final summary report  

DOE Green Energy (OSTI)

The solar desiccant air conditioner (SODAC), its operation, characteristics of the major components, performance at design conditions, and the control schemes for optimum operation in various climates are described for both recirculated and ventilated configurations, with greater emphasis on the recirculated configuration. The development testing and the determination of the SODAC performance in both configurations over the entire range of interfacing parameters are reported. (LEW)

Rousseau, J.

1982-11-01T23:59:59.000Z

183

Analysis and comparison of active solar desiccant and absorption cooling systems. Part 2; Annual simulation results  

DOE Green Energy (OSTI)

A comparative analysis has been performed to compare the cooling and dehumidification performance of future ventilation mode desiccant systems, proposed advanced absorption systems, and conventional vapor compression systems. A common framework has been developed for direct comparison of these different cooling technologies; this method is described in a companion paper. This paper presents the application of this method to annual simulations of cooling system performance in five cities.

Warren, M.L. (ASI Controls, San Ramon, CA (US)); Wahlig, M. (Lawrence Berkeley Lab., CA (USA). Applied Science Div.)

1991-02-01T23:59:59.000Z

184

Printed on recycled paperPERFORMANCE OF A COMBINED SOLAR DESICCANT FILTRATION AIR-CONDITIONING SYSTEM  

E-Print Network (OSTI)

A solar desiccant filtration system and conventional system were compared by simulating their performance over a cooling season using TRNSYS and Typic,aI Meteorological Year (TMY) weather data for a r,a.nge of system p‘arameters. The desiccant dehumidifier was modeled as a heat ‘and m,ass exe hanger with moisture and temperature effectivenesses based on the equilibrium intersection point. The activated carbon filter was modeled as a reduction of required ventilation tlow rate to m,aintain acceptable contamirmnt levels in the space. Several locations were investigated. The desiccant isotherm shape was varied from a moderate Brunauer Type I to silica gel (line,%) and the solar collector a-ea wxs varied from 0 to 4,000 ft2 to see its effect on the savings per season. The isotherm shape ‘and location had little effect on the resulting savings. The savings were between $2,800 and!S4,800 per season depending on the amount of collector carea. 1.

S. M. Burley; M. E. Arden; R. Campbell-howe; B. Wilkins-crowder; T. B. Jekel; J. W. Mitchell; S. A. Klein; W. A. Beckman

1994-01-01T23:59:59.000Z

185

Portable brine evaporator unit, process, and system  

DOE Patents (OSTI)

The present invention discloses a comprehensive, efficient, and cost effective portable evaporator unit, method, and system for the treatment of brine. The evaporator unit, method, and system require a pretreatment process that removes heavy metals, crude oil, and other contaminates in preparation for the evaporator unit. The pretreatment and the evaporator unit, method, and system process metals and brine at the site where they are generated (the well site). Thus, saving significant money to producers who can avoid present and future increases in transportation costs.

Hart, Paul John (Indiana, PA); Miller, Bruce G. (State College, PA); Wincek, Ronald T. (State College, PA); Decker, Glenn E. (Bellefonte, PA); Johnson, David K. (Port Matilda, PA)

2009-04-07T23:59:59.000Z

186

Dew-Point Evaporative Comfort Cooling (Presentation)  

SciTech Connect

Presentation on innovative indirect evaporative cooling technology developed by Coolerado Corporation given at the Rocky Mountain Chapter ASHRAE conference in April 2012.

Dean, J.

2012-10-01T23:59:59.000Z

187

High Efficiency Liquid-Desiccant Regenerator for Air Conditioning and Industrial Drying  

SciTech Connect

Over 2 quads of fossil fuels are used each year for moisture removal. This includes industrial and agricultural processes where feedstocks and final products must be dried, as well as comfort conditioning of indoor spaces where the control of humidity is essential to maintaining healthy, productive and comfortable working conditions. Desiccants, materials that have a high affinity for water vapor, can greatly reduce energy use for both drying and dehumidification. An opportunity exists to greatly improve the competitiveness of advanced liquid-desiccant systems by increasing the efficiency of their regenerators. It is common practice within the chemical process industry to use multiple stage boilers to improve the efficiency of thermal separation processes. The energy needed to regenerate a liquid desiccant, which is a thermal separation process, can also be reduced by using a multiple stage boiler. In this project, a two-stage regenerator was developed in which the first stage is a boiler and the second stage is a scavenging-air regenerator. The only energy input to this regenerator is the natural gas that fires the boiler. The steam produced in the boiler provides the thermal energy to run the second-stage scavenging-air regenerator. This two-stage regenerator is referred to as a 1?-effect regenerator. A model of the high-temperature stage of a 1?-effect regenerator for liquid desiccants was designed, built and successfully tested. At nominal operating conditions (i.e., 2.35 gpm of 36% lithium chloride solution, 307,000 Btu/h firing rate), the boiler removed 153 lb/h of water from the desiccant at a gas-based efficiency of 52.9 % (which corresponds to a COP of 0.95 when a scavenging-air regenerator is added). The steam leaving the boiler, when condensed, had a solids concentration of less than 10 ppm. This low level of solids in the condensate places an upper bound of about 6 lb per year for desiccant loss from the regenerator. This low loss will not create maintenance problems nor will it significantly increase operating expenses. An energy balance on the boiler showed that heat loss through the insulated jacket was 10%. This value is much higher than the 2% to 5% that is typical of most boilers and indicates a need to better insulate the unit. With insulation that brings jacket losses down to 5%, a 1?-effect regenerator that uses this boiler as its high-temperature stage will have a gas-based COP of 1.05. The estimated cost to manufacture a 300-lb/h, 1?-effect regenerator at 500 units per year is $17,140. Unfortunately, the very high cost for natural gas that now prevails in the U.S. makes it very difficult for a gas-fired LDAC to compete against an electric vapor-compression air conditioner in HVAC applications. However, there are important industrial markets that need very dry air where the high price of natural gas will encourage the sale of a LDAC with the 1?-effect regenerator since in these markets it competes against less efficient gas-fired desiccant technologies. A manufacturer of industrial dehumidification equipment is now negotiating a sales agreement with us that would include the 1?-effect regenerator.

Andrew Lowenstein

2005-12-19T23:59:59.000Z

188

A Parameterization of the Evaporation of Rainfall  

Science Conference Proceedings (OSTI)

In this study we develop theoretical expressions for the rainfall rate, P(z), and the total evaporation rate from cloud base to a level z below cloud base, E(z). The resultant parameterization for the total evaporation is given by E(z) = CP?(0)?(...

Michael E. Schlesinger; Jai-Ho Oh; Daniel Rosenfeld

1988-10-01T23:59:59.000Z

189

Advanced evaporator technology progress report FY 1992  

SciTech Connect

This report summarizes the work that was completed in FY 1992 on the program {open_quotes}Technology Development for Concentrating Process Streams.{close_quotes} The purpose of this program is to evaluate and develop evaporator technology for concentrating radioactive waste and product streams such as those generated by the TRUEX process. Concentrating these streams and minimizing the volume of waste generated can significantly reduce disposal costs; however, equipment to concentrate the streams and recycle the decontaminated condensates must be installed. LICON, Inc., is developing an evaporator that shows a great deal of potential for this application. In this report, concepts that need to be incorporated into the design of an evaporator operated in a radioactive environment are discussed. These concepts include criticality safety, remote operation and maintenance, and materials of construction. Both solubility and vapor-liquid equilibrium data are needed to design an effective process for concentrating process streams. Therefore, literature surveys were completed and are summarized in this report. A model that is being developed to predict vapor phase compositions is described. A laboratory-scale evaporator was purchased and installed to study the evaporation process and to collect additional data. This unit is described in detail. Two new LICON evaporators are being designed for installation at Argonne-East in FY 1993 to process low-level radioactive waste generated throughout the laboratory. They will also provide operating data from a full-sized evaporator processing radioactive solutions. Details on these evaporators are included in this report.

Chamberlain, D.; Hutter, J.C.; Leonard, R.A. [and others

1995-01-01T23:59:59.000Z

190

Ion-Drop Interaction During Drop Evaporation  

Science Conference Proceedings (OSTI)

As a basic experiment in warm cloud electrification, evaporating large drops were studied as they floated in an ion-rich environment in a vertical wind tunnel. The drops were found to acquire a positive charge during their evaporation, a result ...

Tsutomu Takahashi; Tatsuo Endoh

1983-02-01T23:59:59.000Z

191

Analysis and design of a solar-powered liquid-desiccant air conditioner for use in hot and humid climates  

SciTech Connect

An experimental and theoretical investigation of the feasibility of a solar-powered liquid-desiccant air conditioner, for use in hot and humid climates, was carried out at the Mechanical Engineering Department, University of Florida. The proposed liquid desiccant system used nonadiabatic contactors, packed with finned-tube coils, for both moist air dehumidification and liquid-desiccant regeneration. A theoretical model was developed to analyze the complex phenomena of simultaneous heat and mass transfer in nonadiabatic contactors, as well as the continuous interaction between the dehumidification and regeneration processes. A computer code was written to assist in the analysis of the dehumidification and regeneration processes separately and coupled, for continuous operation. It was used to investigate the interaction between the different controlling parameters and their effects on the overall performance of the desiccant system. A fully solar-powered liquid-desiccant air-conditioner, with three tons of capacity was designed and optimized including economical criteria. The overall coefficient of performance (COP) of the optimized system was determined to be 0.312.

Chebbah, A.

1987-01-01T23:59:59.000Z

192

Black Hole Evaporation as a Nonequilibrium Process  

E-Print Network (OSTI)

When a black hole evaporates, there arises a net energy flow from the black hole into its outside environment due to the Hawking radiation and the energy accretion onto black hole. Exactly speaking, due to the net energy flow, the black hole evaporation is a nonequilibrium process. To study details of evaporation process, nonequilibrium effects of the net energy flow should be taken into account. In this article we simplify the situation so that the Hawking radiation consists of non-self-interacting massless matter fields and also the energy accretion onto the black hole consists of the same fields. Then we find that the nonequilibrium nature of black hole evaporation is described by a nonequilibrium state of that field, and we formulate nonequilibrium thermodynamics of non-self-interacting massless fields. By applying it to black hole evaporation, followings are shown: (1) Nonequilibrium effects of the energy flow tends to accelerate the black hole evaporation, and, consequently, a specific nonequilibrium phenomenon of semi-classical black hole evaporation is suggested. Furthermore a suggestion about the end state of quantum size black hole evaporation is proposed in the context of information loss paradox. (2) Negative heat capacity of black hole is the physical essence of the generalized second law of black hole thermodynamics, and self-entropy production inside the matter around black hole is not necessary to ensure the generalized second law. Furthermore a lower bound for total entropy at the end of black hole evaporation is given. A relation of the lower bound with the so-called covariant entropy bound conjecture is interesting but left as an open issue.

Hiromi Saida

2008-11-11T23:59:59.000Z

193

Simple predictive model for performance of desiccant beds for solar dehumidification  

DOE Green Energy (OSTI)

A computer model is outlined for the absorption/desorption process that can be used to predict the performance of desiccant beds for solar regenerated dehumidification of passively cooled buildings. Instead of solving a set of coupled differential equations, the model uses simple algebraic equations for steady-state heat and mass exchangers. A comparison of computer predictions and experimental data demonstrate the validity and accuracy of the model. The physics of the adsorption process is discussed in terms of two psychrometric process lines, and planned research efforts at SERI are described.

Barlow, R.S.

1981-08-01T23:59:59.000Z

194

Gas-fired desiccant dehumidification system field evaluation in a quick-service restaurant. Final report, October 1989  

Science Conference Proceedings (OSTI)

This report describes the results of a field evaluation of state-of-art desiccant dehumidification equipment in Houston, TX. The evaluation demonstrated that comfort control in a quick-service restaurant could be improved dramatically. However, available gas-fired desiccant dehumidification equipment is too expensive, inefficient, and unreliable to be considered for wide application in the restaurant industry. Results of a technical and economic analysis of four HVAC options in four U.S. cities indicated that improved comfort control could be achieved with only a modest increase in operating costs with an advanced system. This, coupled with the economic benefits achieved through lower indoor humidity such as improved crew performance and reduced maintenance costs, could justify the introduction of an advanced, integrated, HVAC system using desiccant technology which has an installed cost similar to current equipment.

Koopman, R.N.; Marciniak, T.J.

1989-10-01T23:59:59.000Z

195

On the evaporation of ammonium sulfate solution  

SciTech Connect

Aqueous evaporation and condensation kinetics are poorly understood, and uncertainties in their rates affect predictions of cloud behavior and therefore climate. We measured the cooling rate of 3 M ammonium sulfate droplets undergoing free evaporation via Raman thermometry. Analysis of the measurements yields a value of 0.58 {+-} 0.05 for the evaporation coefficient, identical to that previously determined for pure water. These results imply that subsaturated aqueous ammonium sulfate, which is the most abundant inorganic component of atmospheric aerosol, does not affect the vapor-liquid exchange mechanism for cloud droplets, despite reducing the saturation vapor pressure of water significantly.

Drisdell, Walter S.; Saykally, Richard J.; Cohen, Ronald C.

2009-07-16T23:59:59.000Z

196

Addressing Water Consumption of Evaporative Coolers with Greywater  

E-Print Network (OSTI)

Refrigeration and Air Conditioning Engineers, Inc. 2009.1999. Evaporative Air-Conditioning: Applications forDirect Evaporative Air Conditioning, Final Report . Davis,

Sahai, Rashmi

2013-01-01T23:59:59.000Z

197

Analysis of Evaporation Data From Heated Ponds  

Science Conference Proceedings (OSTI)

Controlled field experiments have improved understanding of the role evaporation plays in the thermal performance and water consumption of utility cooling ponds. The data show significant effects of water surface temperature, fetch or wind direction, and pond sheltering.

1987-04-27T23:59:59.000Z

198

The Temperature of Evaporating Sea Spray Droplets  

Science Conference Proceedings (OSTI)

Evaporating sea spray droplets are often assumed to be at the temperature of a well-ventilated wet-bulb thermometer, Twet. Although this assumption may be accurate enough in practice, it is incorrect on theoretical grounds. Spray droplets have ...

Edgar L. Andreas

1995-04-01T23:59:59.000Z

199

Dynamic performance of packed-bed dehumidifiers: experimental results from the SERI desiccant test loop  

DOE Green Energy (OSTI)

Discussed are the design and construction of a desiccant test loop and results of tests with a silica-gel-packed bed. The test loop consists of two centrifugal fans, two duct heaters, a steam humidifier, 24.4m (80 ft) of 30-cm (12-in.) circular duct, instrumentation, and a test section. The loop is capable of testing adsorption and desorption modes at flow rates up to 0.340 kg/s (600 scfm) and at regeneration temperatures up to 120/sup 0/C (248/sup 0/F). Tests of a 74-cm(29-in.)-diameter, 3.2-cm(1.25-in.)-thick silica gel bed indicated that mass transfer occurs more readily in the adsorption direction than in the desorption direction. Pressure drop data indicated that the resistance of each of the two screens that hold the silica gel in place was equivalent to 2.5-cm(1-in.) of silica gel due to plugging. Results of the tests were also used to validate a SERI desiccant computer model, DESSIM.

Kutscher, C F; Barlow, R S

1982-08-01T23:59:59.000Z

200

Ball feeder for replenishing evaporator feed  

DOE Patents (OSTI)

Vapor source material such as uranium, which is to be dropped into a melt in an evaporator, is made into many balls of identical diameters and placed inside a container. An elongated sloping pipe is connected to the container and leads to the evaporator such that these balls can travel sequentially therealong by gravity. A metering valve in this pipe for passing these balls one at a time is opened in response to a signal when it is ascertained by a detector that there is a ball ready to be passed. A gate in the pipe near the evaporator momentarily stops the motion of the traveling ball and is then opened to allow the ball drop into the melt at a reduced speed.

Felde, D.K.; McKoon, R.H.

1993-03-23T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

Ball feeder for replenishing evaporator feed  

DOE Patents (OSTI)

Vapor source material such as uranium, which is to be dropped into a melt in an evaporator, is made into many balls of identical diameters and placed inside a container. An elongated sloping pipe is connected to the container and leads to the evaporator such that these balls can travel sequentially therealong by gravity. A metering valve in this pipe for passing these balls one at a time is opened in response to a signal when it is ascertained by a detector that there is a ball ready to be passed. A gate in the pipe near the evaporator momentarily stops the motion of the traveling ball and is then opened to allow the ball drop into the melt at a reduced speed.

Felde, David K. (Oak Ridge, TN); McKoon, Robert H. (San Ramon, CA)

1993-01-01T23:59:59.000Z

202

Zero Carryover Liquid-Desiccant Air Conditioner for Solar Applications: Preprint  

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

A Zero Carryover A Zero Carryover Liquid-Desiccant Air Conditioner for Solar Applications Preprint A. Lowenstein AIL Research, Inc. S. Slayzak and E. Kozubal National Renewable Energy Laboratory To be presented at ASME International Solar Energy Conference (ISEC2006) Denver, Colorado July 8-13, 2006 Conference Paper NREL/CP-550-39798 July 2006 NOTICE The submitted manuscript has been offered by an employee of the Midwest Research Institute (MRI), a contractor of the US Government under Contract No. DE-AC36-99GO10337. Accordingly, the US Government and MRI retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. This report was prepared as an account of work sponsored by an agency of the United States government.

203

Development of a solar desiccant dehumidifier. Phase II. Technical progress report  

DOE Green Energy (OSTI)

The effort reported is a continuation of the development testing of the 1.5-ton solar desiccant air conditioner (SODAC) and is concerned with determination of the SODAC performance in the recirculated and ventilated mode configuration. Test data in the recirculated mode are presented. As originally conceived, the SODAC features two-speed indoor and outdoor fans to permit more efficient operation at reduced capacity. In both full-flow and half-flow cases, the experimental data are compared to computer predictions. The system and its operation are described, as are the system test facility and procedures. The system description includes the characteristics of the major components, the performance at design conditions, and the control schemes for optimum operation in various climates. (LEW)

Rousseau, J.

1981-03-27T23:59:59.000Z

204

Testing of a solar powered cooling system using cross-cooled desiccant dehumidifiers  

DOE Green Energy (OSTI)

A solar powered desiccant cooling system using two fixed bed silica gel dehumidifiers has been designed, built and is being tested. The dehumidifiers, 0.6 x 0.6 x 0.6 m each, are constructed of 80 channels lined with 64 m/sup 2/ of 1.5 mm thick silica gel sheets. The bed is cooled by air flowing in an equal number of perpendicular channels. Both sets of channels are two mm wide, the dehumidifiers undergo adsorption, preheating, desorption and precooling in a cyclic fashion. The cooling capacity of the experimental system is one ton at ARI design conditions. The system has a high cooling capacity, high COP, low parasitic power consumption and requires low regeneration temperatures.

Monnier, J.B.; Worek, W.M.; Lavan, Z.

1981-01-01T23:59:59.000Z

205

Hot air drum evaporator. [Patent application  

DOE Patents (OSTI)

An evaporation system for aqueous radioactive waste uses standard 30 and 55 gallon drums. Waste solutions form cascading water sprays as they pass over a number of trays arranged in a vertical stack within a drum. Hot dry air is circulated radially of the drum through the water sprays thereby removing water vapor. The system is encased in concrete to prevent exposure to radioactivity. The use of standard 30 and 55 gallon drums permits an inexpensive compact modular design that is readily disposable, thus eliminating maintenance and radiation build-up problems encountered with conventional evaporation systems.

Black, R.L.

1980-11-12T23:59:59.000Z

206

Direct Evaporative Precooling Model and Analysis  

SciTech Connect

Evaporative condenser pre-cooling expands the availability of energy saving, cost-effective technology options (market engagement) and serves to expedite the range of options in upcoming codes and equipment standards (impacting regulation). Commercially available evaporative pre-coolers provide a low cost retrofit for existing packaged rooftop units, commercial unitary split systems, and air cooled chillers. We map the impact of energy savings and peak energy reduction in the 3 building types (medium office, secondary school, and supermarket) in 16 locations for three building types with four pad effectivenesses and show the effect for HVAC systems using either refrigerants R22 or R410A

Shen, Bo [ORNL; Ally, Moonis Raza [ORNL; Rice, C Keith [ORNL; Craddick, William G [ORNL

2011-01-01T23:59:59.000Z

207

New and Underutilized Technology: Evaporative Pre-Cooling Systems |  

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

Evaporative Pre-Cooling Systems Evaporative Pre-Cooling Systems New and Underutilized Technology: Evaporative Pre-Cooling Systems October 4, 2013 - 4:43pm Addthis The following information outlines key deployment considerations for evaporated pre-cooling systems within the Federal sector. Benefits Evaporative pre-cooling systems install ahead of the condenser to lower the condenser pressure. These systems can also work with an economizer. Evaporative pre-cooling reduces the requirement for energy intensive DX cooling. Application Evaporative pre-cooling systems are applicable in most building categories. Climate and Regional Considerations Evaporative pre-cooling systems are well suited in dry climates. Key Factors for Deployment Water usage needs to be taken into account in evaporative pre-cooling

208

New and Underutilized Technology: Evaporative Pre-Cooling Systems |  

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

Technology: Evaporative Pre-Cooling Systems Technology: Evaporative Pre-Cooling Systems New and Underutilized Technology: Evaporative Pre-Cooling Systems October 4, 2013 - 4:43pm Addthis The following information outlines key deployment considerations for evaporated pre-cooling systems within the Federal sector. Benefits Evaporative pre-cooling systems install ahead of the condenser to lower the condenser pressure. These systems can also work with an economizer. Evaporative pre-cooling reduces the requirement for energy intensive DX cooling. Application Evaporative pre-cooling systems are applicable in most building categories. Climate and Regional Considerations Evaporative pre-cooling systems are well suited in dry climates. Key Factors for Deployment Water usage needs to be taken into account in evaporative pre-cooling

209

Tank 26F-2F Evaporator Study  

Science Conference Proceedings (OSTI)

Tank 26F supernate sample was sent by Savannah River Remediation to Savannah River National Laboratory for evaporation test to help understand the underlying cause of the recent gravity drain line (GDL) pluggage during operation of the 2F Evaporator system. The supernate sample was characterized prior to the evaporation test. The evaporation test involved boiling the supernate in an open beaker until the density of the concentrate (evaporation product) was between 1.4 to 1.5 g/mL. It was followed by filtering and washing of the precipitated solids with deionized water. The concentrate supernate (or concentrate filtrate), the damp unwashed precipitated solids, and the wash filtrates were characterized. All the precipitated solids dissolved during water washing. A semi-quantitative X-ray diffraction (XRD) analysis on the unwashed precipitated solids revealed their composition. All the compounds with the exception of silica (silicon oxide) are known to be readily soluble in water. Hence, their dissolution during water washing is not unexpected. Even though silica is a sparingly water-soluble compound, its dissolution is also not surprising. This stems from its small fraction in the solids as a whole and also its relative freshness. Assuming similar supernate characteristics, flushing the GDL with water (preferably warm) should facilitate dissolution and removal of future pluggage events as long as build up/aging of the sparingly soluble constituent (silica) is limited. On the other hand, since the amount of silica formed is relatively small, it is quite possible dissolution of the more soluble larger fraction will cause disintegration or fragmentation of the sparingly soluble smaller fraction (that may be embedded in the larger soluble solid mass) and allow its removal via suspension in the flushing water.

Adu-Wusu, K.

2012-12-19T23:59:59.000Z

210

Experimental studies of heat and mass exchange in parallel-passage rotary desiccant dehumidifiers for solar cooling applications  

DOE Green Energy (OSTI)

This report presents results of work done to experimentally characterize the performance of rotary desiccant dehumidifiers and to develop and validate analytical methods for evaluating their performance in air-conditioning systems. A facility, the Cyclic Test Facility, and a test-and-analysis procedure were developed to evaluate the performance of the rotary dehumidifiers. Experiments were performed to develop a basic understanding of the simultaneous heat- and mass-transfer processes in the dehumidifiers. Two test articles were tested under cyclic operation to characterize their performance. Detailed accounts of the Cyclic Test Facility, its hardware and instrumentation, the two test articles, and data reduction and analysis methods are provided. The data provide an engineering data base for evaluating rotary desiccant dehumidifiers for cooling applications. 46 refs., 26 figs., 3 tabs.

Bharathan, D.; Parsons, J.M.; Maclaine-cross, I.L.

1987-11-01T23:59:59.000Z

211

The Experimentation System Design and Experimental Study of the Air-Conditioning by Desiccant Type Using Solar Energy  

E-Print Network (OSTI)

Using a special solar air heater to gain heat power for regenerating an adsorption desiccant wheel made by composite silica gel, a desiccant air-conditioning experimentation system was designed and manufactured. Combining the advantage of measure and control by “PLC” and the software of “Kingview”, the whole year's operating results of this system was tested and analysed. The results indicate this system can keep the indoor air temperature range at 26±2°C and the relative humidity range being 50-70% under the low electricity cost on the whole year in the south of China region when the special solar air heater can offer flux air heating up to 60°C. In this paper some ideas are offered in order to facilitate the availability for air-conditioning using low grade energy, for example, solar energy and surplus or waste heat energy in the industrial process.

Zhuo, X.; Ding, J.; Yang, X.; Chen, S.; Yang, J.

2006-01-01T23:59:59.000Z

212

New and Underutilized Technology: Multi-stage Indirect Evaporative Cooling  

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

Multi-stage Indirect Evaporative Multi-stage Indirect Evaporative Cooling New and Underutilized Technology: Multi-stage Indirect Evaporative Cooling October 4, 2013 - 4:33pm Addthis The following information outlines key deployment considerations for multi-stage evaporative cooling within the Federal sector. Benefits Multi-stage indirect evaporative cooling is an advanced evaporative cooler that can lower air temperatures without adding moisture. These systems evaporate water in a secondary (or working) airstream, which is discharged in multiple stages. No water or humidity is added to the primary (or product) airstream in the process. Application Multi-stage indirect evaporative cooling is applicable in office, research and development, service, and school applications. Climate and Regional Considerations

213

Convection-Evaporation Feedback in the Equatorial pacific  

Science Conference Proceedings (OSTI)

The coupling between convection and surface evaporation is investigated to assess the importance of evaporative cooling in regulating the tropical sea surface temperature. It is found that such a coupling is scale dependent. On timescales of ...

Guang Jun Zhang; V. Ramanathan; Michael J. McPhaden

1995-12-01T23:59:59.000Z

214

On the Evaporation Duct for Inhomogeneous Conditions in Coastal Regions  

Science Conference Proceedings (OSTI)

Evaporation ducts are ubiquitous phenomena over the oceans, and they are responsible for much of the over-the-horizon propagation occurring with millimeter and microwave radars. The height of the evaporation duct depends on meteorological ...

G. L. Geernaert

2007-04-01T23:59:59.000Z

215

New Approach to the Measurement of Interception Evaporation  

Science Conference Proceedings (OSTI)

Evaporation of water intercepted by vegetation represents an important (sometimes major) part of evapotranspiration in temperate regions. Interception evaporation is an important process where insufficient measurement techniques hamper progress ...

A. Lundberg; M. Eriksson; S. Halldin; E. Kellner; J. Seibert

1997-10-01T23:59:59.000Z

216

Sensible Heat Observations Reveal Soil-Water Evaporation Dynamics  

Science Conference Proceedings (OSTI)

Soil-water evaporation is important at scales ranging from microbial ecology to large-scale climate. Yet routine measurements are unable to capture rapidly shifting near-surface soil heat and water processes involved in soil-water evaporation. ...

J. L. Heitman; R. Horton; T. J. Sauer; T. M. DeSutter

2008-02-01T23:59:59.000Z

217

Global Atmospheric Evaporative Demand over Land from 1973 to 2008  

Science Conference Proceedings (OSTI)

Pan evaporation (EP), an index of atmospheric evaporative demand, has been widely reported to have weakened in the past decades. However, its interpretation remains controversial because EP observations are not globally available and observations ...

Kaicun Wang; Robert E. Dickinson; Shunlin Liang

2012-12-01T23:59:59.000Z

218

Chemical Potential Jump during Evaporation of a Quantum Bose Gas  

E-Print Network (OSTI)

The dependence of the chemical potential jump coefficient on the evaporation coefficient is analyzed for the case in which the evaporating component is a Bose gas. The concentration of the evaporating component is assumed to be much lower than the concentration of the carrier gas. The expression for the chemical potential jump is derived from the analytic solution of the problem for the case in which the collision frequency of molecules of the evaporating component is constant.

E. A. Bedrikova; A. V. Latyshev

2013-01-07T23:59:59.000Z

219

Field Evaluation of Desiccant-Integrated HVAC Systems: A Review of Case Studies in Multiple Commercial/Institutional Building Types  

E-Print Network (OSTI)

An independent field research effort co-funded by the Gas Research Institute and The U.S. Department of Energy (DOE) Oak Ridge National Laboratory is documenting the performance and energy usage characteristics of active desiccant-integrated HVAC systems at a variety of commercial and institutional facilities. The tests comprise the instrumentation and one-year-plus monitoring of two or more nearly identical sites, one serving as the test site and the others as base-case or control sites. While the research program is ongoing, work completed in two market sectors, retail and lodging, indicates that there are significant comfort control, energy usage and equipment efficiency benefits to be derived from integrating desiccant units into HVAC system design to handle latent and sensible loads independently. In some cases, installed first costs associated with including desiccant units may be lower if the HVAC system is optimized to take advantage of reduced conventional cooling equipment requirements and downsized ductwork In most cases, lower energy consumption and/or reduced energy costs may provide reasonable payback of first cost premiums.

Yborra, S. C.

1998-01-01T23:59:59.000Z

220

Application Research of Evaporative Cooling in the Waste Heat Recovery  

Science Conference Proceedings (OSTI)

Evaporative condenser is one kind of high-efficient and energy-water saving heat exchange equipment, which has been widely applied in many engineering fields. The theory and product characteristic of evaporative condenser is introduced in this paper. ... Keywords: Evaporative condenser, Waste heat recovery, Energy saving, Water saving

Zhijiang Wu; Nan Wang; Gongsheng Zhu

2010-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

EVAPORATIVE COOLING - CONCEPTUAL DESIGN FOR ATLAS SCT  

E-Print Network (OSTI)

The conceptual design of an evaporative two-phase flow cooling system for the ATLAS SCT detector is described, using perfluorinated propane (C3F8) as a coolant. Comparison with perfluorinated butane (C4F10) is made, although the detailed design is presented only for C3F8. The two-phase pressure drop and heat transfer coefficient are calculated in order to determine the dimensions of the cooling pipes and module contacts for the Barrel SCT. The region in which the flow is homogeneous is determined. The cooling cycle, pipework, compressor, heat exchangers and other main elements of the system are calculated in order to be able to discuss the system control, safety and reliability. Evaporative cooling appears to be substantially better than the binary ice system from the point of view of safety, reliability, detector thickness, heat transfer coefficient, cost and simplicity.

Niinikoski, T O

1998-01-01T23:59:59.000Z

222

The Partitioning of Evapotranspiration into Transpiration, Soil Evaporation, and Canopy Evaporation in a GCM: Impacts on Land–Atmosphere Interaction  

Science Conference Proceedings (OSTI)

Although the global partitioning of evapotranspiration (ET) into transpiration, soil evaporation, and canopy evaporation is not well known, most current land surface schemes and the few available observations indicate that transpiration is the ...

David M. Lawrence; Peter E. Thornton; Keith W. Oleson; Gordon B. Bonan

2007-08-01T23:59:59.000Z

223

Information Loss in Black Hole Evaporation  

E-Print Network (OSTI)

Parikh-Wilczek tunnelling framework is investigated again. We argue that Parikh-Wilczek's treatment, which satisfies the first law of black hole thermodynamics and consists with an underlying unitary theory, is only suitable for a reversible process. Because of the negative heat capacity, an evaporating black hole is a highly unstable system. That is, the factual emission process is irreversible, the unitary theory will not be satisfied and the information loss is possible.

Jingyi Zhang; Yapeng Hu; Zheng Zhao

2005-12-11T23:59:59.000Z

224

Colloidal Shape Effects in Evaporating Drops  

E-Print Network (OSTI)

We explore the influence of particle shape on the behavior of evaporating drops. A first set of experiments discovered that particle shape modifies particle deposition after drying. For sessile drops, spheres are deposited in a ring-like stain, while ellipsoids are deposited uniformly. Experiments elucidate the kinetics of ellipsoids and spheres at the drop's edge. A second set of experiments examined evaporating drops confined between glass plates. In this case, colloidal particles coat the ribbon-like air-water interface, forming colloidal monolayer membranes (CMMs). As particle anisotropy increases, CMM bending rigidity was found to increase, which in turn introduces a new mechanism that produces a uniform deposition of ellipsoids and a heterogeneous deposition of spheres after drying. A final set of experiments investigates the effect of surfactants in evaporating drops. The radially outward flow that pushes particles to the drop's edge also pushes surfactants to the drop's edge, which leads to a radially inward flow on the drop surface. The presence of radially outward flows in the bulk fluid and radially inward flows at the drop surface creates a Marangoni eddy, among other effects, which also modifies deposition after drying.

Peter J. Yunker; Tim Still; A. G. Yodh

2013-08-08T23:59:59.000Z

225

Evaporated lithium surface coatings in NSTX.  

Science Conference Proceedings (OSTI)

Two lithium evaporators were used to evaporate more than 100 g of lithium on to the NSTX lower divertor region. Prior to each discharge, the evaporators were withdrawn behind shutters, where they also remained during the subsequent HeGDC applied for periods up to 9.5 min. After the HeGDC, the shutters were opened and the LITERs were reinserted to deposit lithium on the lower divertor target for 10 min, at rates of 10-70 mg/min, prior to the next discharge. The major improvements in plasma performance from these lithium depositions include: (1) plasma density reduction as a result of lithium deposition; (2) suppression of ELMs; (3) improvement of energy confinement in a low-triangularity shape; (4) improvement in plasma performance for standard, high-triangularity discharges; (5) reduction of the required HeGDC time between discharges; (6) increased pedestal electron and ion temperature; (7) reduced SOL plasma density; and (8) reduced edge neutral density.

Zakharov, L. (Princeton Plasma Physics Laboratory, Princeton, NJ); Gates, D. (Princeton Plasma Physics Laboratory, Princeton, NJ); Menard, J. (Princeton Plasma Physics Laboratory, Princeton, NJ); Maingi, R. (Oak Ridge National Laboratory, Oak Ridge, TN); Schneider, H. (Princeton Plasma Physics Laboratory, Princeton, NJ); Mueller, D. (Princeton Plasma Physics Laboratory, Princeton, NJ); Wampler, William R.; Roquemore, A. L. (Princeton Plasma Physics Laboratory, Princeton, NJ); Kallman, Jeffrey K. (Princeton Plasma Physics Laboratory, Princeton, NJ); Sabbagh, S. (Columbia University, New York, NY); LeBlanc, B. (Princeton Plasma Physics Laboratory, Princeton, NJ); Raman, R. (University of Washington, Seattle, WA); Ono, M. (Princeton Plasma Physics Laboratory, Princeton, NJ); Wilgren, J. (Oak Ridge National Laboratory, Oak Ridge, TN); Allain, J.P. (Purdue University, West Lafayette, IN); Timberlake, J. (Princeton Plasma Physics Laboratory, Princeton, NJ); Stevenson, T. (Princeton Plasma Physics Laboratory, Princeton, NJ); Ross, P. W. (Princeton Plasma Physics Laboratory, Princeton, NJ); Majeski, R. (Princeton Plasma Physics Laboratory, Princeton, NJ); Kugel, Henry W. (Princeton Plasma Physics Laboratory, Princeton, NJ); Skinner, C. H. (Princeton Plasma Physics Laboratory, Princeton, NJ); Gerhardt, S. (Princeton Plasma Physics Laboratory, Princeton, NJ); Paul, S. (Princeton Plasma Physics Laboratory, Princeton, NJ); Bell, R. (Princeton Plasma Physics Laboratory, Princeton, NJ); Kaye, S. M. (Princeton Plasma Physics Laboratory, Princeton, NJ); Kaita, R. (Princeton Plasma Physics Laboratory, Princeton, NJ); Soukhanovskii, V. (Lawrence Livermore National Laboratory, Livermore, CA); Bell, Michael G. (Princeton Plasma Physics Laboratory, Princeton, NJ); Mansfield, D. (Princeton Plasma Physics Laboratory, Princeton, NJ)

2008-08-01T23:59:59.000Z

226

Nuclear evaporation process with simultaneous multiparticle emission  

E-Print Network (OSTI)

The nuclear evaporation process is reformulated by taking into account simultaneous multiparticle emission from a hot compound nucleus appearing as an intermediate state in many nuclear reaction mechanisms. The simultaneous emission of many particles is particularly relevant for high excitation energy of the compound nucleus.These channels are effectively open in competition with the single particle emissions and fission in this energy regime. Indeed, the inclusion of these channels along the decay evaporating chain shows that the yield of charged particles and occurrence of fission are affected by these multiparticle emission processes of the compounded nucleus, when compared to the single sequential emission results. The effect also shows a qualitative change in the neutron multiplicity of different heavy compound nucleus considered. This should be an important aspect for the study of spallation reaction in Acceleration Driven System (ADS) reactors. The majority of neutrons generated in these reactions come from the evaporation stage of the reaction, the source of neutron for the system. A Monte Carlo simulation is employed to determine the effect of these channels on the particle yield and fission process. The relevance of the simultaneous particle emission with the increasing of excitation energy of the compound nucleus is explicitly shown.

Leonardo P. G. De Assis; Sergio B. Duarte; Bianca M. Santos

2012-08-07T23:59:59.000Z

227

Zero Energy Communities with Central Solar Plants using Liquid Desiccants and Local Storage: Preprint  

DOE Green Energy (OSTI)

The zero energy community considered here consists of tens to tens-of-thousands of residences coupled to a central solar plant that produces all the community's electrical and thermal needs. A distribution network carries fluids to meet the heating and cooling loads. Large central solar systems can significantly reduce cost of energy vs. single family systems, and they enable economical seasonal heat storage. However, the thermal distribution system is costly. Conventional district heating/cooling systems use a water/glycol solution to deliver sensible energy. Piping is sized to meet the peak instantaneous load. A new district system introduced here differs in two key ways: (i) it continuously distributes a hot liquid desiccant (LD) solution to LD-based heating and cooling equipment in each home; and (ii) it uses central and local storage of both LD and heat to reduce flow rates to meet average loads. Results for piping sizes in conventional and LD thermal communities show that the LD zero energy community reduces distribution piping diameters meeting heating loads by {approx}5X and meeting cooling loads by {approx}8X for cooling, depending on climate.

Burch, J.; Woods, J.; Kozubal, E.; Boranian, A.

2012-08-01T23:59:59.000Z

228

The evaporative gas turbine (EGT) cycle  

SciTech Connect

Humidification of the flow through a gas turbine has been proposed in a variety of forms. The STIG plant involves the generation of steam by the gas turbine exhaust in a heat recovery steam generator (HRSG), and its injection into or downstream of the combustion chamber. This increases the mass flow through the turbine and the power output from the plant, with a small increase in efficiency. In the evaporative gas turbine (or EGT) cycle, water is injected in the compressor discharge in a regenerative gas turbine cycle (a so-called CBTX plant--compressor [C], burner [B], turbine [T], heat exchanger [X]); the air is evaporatively cooled before it enters the heat exchanger. While the addition of water increases the turbine mass flow and power output, there is also apparent benefit in reducing the temperature drop in the exhaust stack. In one variation of the basic EGT cycle, water is also added downstream of the evaporative aftercooler, even continuously in the heat exchanger. There are several other variations on the basic cycle (e.g., the cascaded humidified advanced turbine [CHAT]). The present paper analyzes the performance of the EGT cycle. The basic thermodynamics are first discussed, and related to the cycle analysis of a dry regenerative gas turbine plant. Subsequently some detailed calculations of EGT cycles are presented. The main purpose of the work is to seek the optimum pressure ratio in the EGT cycle for given constraints (e.g., fixed maximum to minimum temperature). It is argued that this optimum has a relatively low value.

Horlock, J.H. [Whittle Lab., Cambridge (United Kingdom)

1998-04-01T23:59:59.000Z

229

Radion clouds around evaporating black holes  

E-Print Network (OSTI)

A Kaluza-Klein model, with a matter source associated with Hawking radiation from an evaporating black hole, is used to obtain a simple form for the radion effective potential. The environmental effect generally causes a matter-induced shift of the radion vacuum, resulting in the formation of a radion cloud around the hole. There is an albedo due to the radion cloud, with an energy dependent reflection coefficient that depends upon the size of the extra dimensions and the temperature of the hole.

J. R. Morris

2009-09-03T23:59:59.000Z

230

Study of falling-jet flash evaporators  

DOE Green Energy (OSTI)

Experimental results of flash evaporation from sheets of water, 3.2 mm and 6.3 mm thick and 27.9 cm wide, falling freely in the presence of their own vapor, are reported. With no flashing the jets fall in coherent sheets, but with flashing the jets were observed to spread and break up into droplets. Flashing was characterized by an effectiveness parameter, which was found to increase with increasing water temperature and jet length. Variations in water flow rate and heat flux did not influence the effectiveness appreciably.

Kreith, F.; Olson, D.A.; Bharathan, D.; Green, H.J.

1982-11-01T23:59:59.000Z

231

Analysis and development of a solar energy regenerated desiccant crop drying facility: Phase I. Final report, July 1976--April 1977  

DOE Green Energy (OSTI)

The results of a study to verify the technical feasibility of the regenerated desiccant crop drying concept, characterize its performance, investigate design requirements, and define a pilot facility for further evaluating the operational and energy-conservative characteristics of the drying system are documented. The pilot facility defined in this study will be a use R and D tool of sufficient size to permit a meaningful evaluation of the system and to provide the necessary criteria for development of full-scale systems. The principal finding of the study is that the regenerated desiccant crop drying concept is technically feasible and has the capability to achieve a drying efficiency of approximately twice that of conventional crop drying systems. When using a fossil fuel energy source, energy savings will be approximately 40 to 50%. With solar energy input, the total fossil fuel savings could be 70 to 90%. The economic feasibility of the system appears promising. As with other new energy conserving systems that are presently capital-intensive, the economic viability of the system will be dependent on future capital cost reductions, on the future price of fossil fuels, and on the specific application of the system. Regarding system applications, it was concluded that the regenerated desiccant drying system, with or without the use of solar energy, will be economically best suited for a large central processing application, where it can receive a maximum amount of use and will benefit from economy-of-scale cost considerations. The basic study recommendations are: (1) additional R and D activities should be conducted to identify and evaluate means for achieving system cost reductions, and (2) the Mobile Pilot Facility program should be initiated.

Ko, S.M.; Merrifield, D.V.; Fletcher, J.W.

1977-04-01T23:59:59.000Z

232

A Comparison of Australian Open Water Body Evaporation Trends for Current and Future Climates Estimated from Class A Evaporation Pans and General Circulation Models  

Science Conference Proceedings (OSTI)

Trends of decreasing pan evaporation around the world have renewed interest in evaporation and its behavior in a warming world. Observed pan evaporation around Australia has been modeled to attribute changes in its constituent variables. It is ...

Fiona Johnson; Ashish Sharma

2010-02-01T23:59:59.000Z

233

Rain on the Roof-Evaporative Spray Roof Cooling  

E-Print Network (OSTI)

This paper describes evaporative spray roof cooling systems, their components, performance and applications in various climates and building types. The evolution of this indirect evaporative cooling technique is discussed. Psychrometric and sol-air principles are covered and a simplified method of evaluation presented. A life cycle energy savings example is discussed. Benefits of roof life and roof top equipment efficiency and maintenance are covered as well as water consumption and performance trade-offs with alternate methods of roof heat gain control. Testimonials and case studies are presented. The gradual migration of business, industry, and populace to the southern United States was largely brought on by the advent of the practical air-conditioner, cheap electricity, and the harshness of northern winters. But while "wintering at Palm Beach" has been replaced by "Sun Belt industries" ; the compression-refrigeration cooling cycle is about the only thing separating millions of southerners (native and adopted) from August heat stroke and the Detroit News employment ads. This migration has been spurred by economic recessions which hit harder at the competitively populated northern centers than at the still growing industries of the south. These trends are important illustrations of the concern for efficient cooling strategies. Not only are homes in hot climates vulnerable to the now not-so-low cost of electricity but large, compact. and heavily occupied buildings (offices, schools, hospitals, theaters, etc.) often must air-condition year-around. In 1968. air-conditioning was 3% of U.S. end energy consumption compared to 18% for space heating and 25% for transportation. By 1980, according to Electric Power Research Institute's Oliver Yu, air-conditioning use was 12.5% of all electricity generated and by the year 2000 is projected to reach 16.7% "as migration slows and the GNP reaches a stable 3% growth rate" (EPRI 1982 to 1986 Overview and Strategy). Of further significance is the effect of air-conditioning loads on the peak generating requirements of electrical utilities. Because utilities must build generating capacity to meet peak requirements, they normally charge a higher summer kWh rate (for residential) and levy a peak kW demand charge on a monthly or even annual "ratchet" rate (for larger service customers). The June '83 cover of Houston City Magazine, in reference to future electrical rates, promised: "Pay or Sweat". Typical of many cooling or heat gain prevention strategies being employed on "innovative" buildings in warm climates, evaporative spray roof cooling (ESRC) systems (not to be confused with roof ponds) are not new. Like ventilated structures, ice house roofs, enhanced ventilation, masonry walls, night sky radiation and ground contact cooling, evaporative cooling in many forms has been around for centuries. (See Solar Age, July '82 and February '81 for related articles). Even the development of roof spray systems is not as newly founded as one might suspect.

Bachman, L. R.

1985-01-01T23:59:59.000Z

234

Development of a Direct Evaporator for the Organic Rankine Cycle  

Science Conference Proceedings (OSTI)

Presentation Title, Development of a Direct Evaporator for the Organic Rankine Cycle. Author(s), Donna Post Guillen, Helge Klockow, Matthew Lehar, Sebastian

235

Addressing Water Consumption of Evaporative Coolers with Greywater  

E-Print Network (OSTI)

5 3. Water Consumption of Evaporative7 3.1.2. Water Consumption Due to9 3.1.4. Water Consumption due to

Sahai, Rashmi

2013-01-01T23:59:59.000Z

236

"Increasing Solar Panel Efficiency And Reliability By Evaporative...  

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

Increasing Solar Panel Efficiency And Reliability By Evaporative Cooling" Inventors..--.. Lewis Meixler, Charles Gentile, Patricia Hillyer, Dylan Carpe, Jason Wang, Caroline Brooks...

237

Electron Beam Evaporator Systems for Thin Film Deposition  

Science Conference Proceedings (OSTI)

The Thin Film and Nanostructure Processing Group has two high-vacuum, electron beam evaporator systems for fabrication of single and multilayer ...

2012-10-23T23:59:59.000Z

238

Reaction mechanism and reaction rate of Sn evaporation from liquid ...  

Science Conference Proceedings (OSTI)

Although Sn is not easily removed by oxidation, Sn can be evaporated as Sn(g) and SnS(g), respectively. Increasing [%S] thus accelerates detinning rate.

239

Soft ionization of thermally evaporated hypergolic ionic liquid aerosols  

E-Print Network (OSTI)

+ ][Dca ? ]. Figure 2. Aerosol particle size distribution ofhypergolic ionic liquid aerosols Christine J. Koh † , Chen-ionization of evaporated IL aerosols Isolated ion pairs of a

Koh, Christine J.

2013-01-01T23:59:59.000Z

240

Research on Convective Heat Transfer and Mass Transfer of the Evaporator in Micro/Mini-Channel  

E-Print Network (OSTI)

With the development of science and technology, various heating and cooling equipment have a development trend of micromation. Micro-fabrication processes make it possible to conduct research on condensation heat transfer in micro-channels. Based on the reviewers on the present household air conditioners, the potential requirements for new heat transfer enhancement used for household air conditioners are discussed. Investigations on condensation and boiling of refrigerants in mini/micro channels have indicated that the evaporator and condenser of air conditioner would be more efficient and more compact by using microchannels, and hence it could improve the coefficient of performance of air conditioners to meet the new energy conversion standards in China. The relationship between condensation heat transfer of refrigerants and surface physical characteristics of the evaporator are pointed out and analyzed in order to achieving the corresponding heat transfer coefficients.

Su, J.; Li, J.

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

Field Demonstration of Active Desiccant Modules Designed to Integrate with Standard Unitary Rooftop Package Equipment - Final Report: Phase 3  

SciTech Connect

This report summarizes the investigation of two active desiccant module (ADM) pilot site installations initiated in 2001. Both pilot installations were retrofits at existing facilities served by conventional heating, ventilating, and air-conditioning (HVAC) systems that had encountered frequent humidity control, indoor air quality (IAQ), and other operational problems. Each installation involved combining a SEMCO, Inc., ADM (as described in Fischer and Sand 2002) with a standard packaged rooftop unit built by the Trane Company. A direct digital control (DDC) system integral to the ADM performed the dual function of controlling the ADM/rooftop combination and facilitating data collection, trending, and remote performance monitoring. The first installation involved providing preconditioned outdoor air to replace air exhausted from the large kitchen hood and bathrooms of a Hooters restaurant located in Rome, Georgia. This facility had previously added an additional rooftop unit in an attempt to achieve occupant comfort without success. The second involved conditioning the outdoor air delivered to each room of a wing of the Mountain Creek Inn at the Callaway Gardens resort. This hotel, designed in the ''motor lodge'' format with each room opening to the outdoors, is located in southwest Georgia. Controlling the space humidity always presented a serious challenge. Uncomfortable conditions and musty odors had caused many guests to request to move to other areas within the resort. This is the first field demonstration performed by Oak Ridge National Laboratory where significant energy savings, operating cost savings, and dramatically improved indoor environmental conditions can all be claimed as the results of a retrofit desiccant equipment field installation. The ADM/rooftop combination installed at the restaurant resulted in a reduction of about 34% in the electricity used by the building's air-conditioning system. This represents a reduction of approximately 15% in overall electrical energy consumption and a 12.5-kW reduction in peak demand. The cost of gas used for regeneration of the desiccant wheel over this period of time is estimated to be only $740, using a gas cost of $0.50 per therm--the summer rate in 2001. The estimated net savings is $5400 annually, resulting in a 1-2 year payback. It is likely that similar energy/cost savings were realized at the Callaway Gardens hotel. In this installation, however, a central plant supplied the chilled water serving fan coil units in the hotel wing retrofitted with the ADM, so it was not metered separately. Consequently, the owner could not provide actual energy consumption data specific to the facility. The energy and operating cost savings at both sites are directly attributable to higher cooling-season thermostat settings and decreased conventional system run times. These field installations were selected as an immediate and appropriate response to correct indoor humidity and fresh air ventilation problems being experienced by building occupants and owners, so no rigorous baseline-building vs. test-building energy use/operating cost savings results can be presented. The report presents several simulated comparisons between the ADM/roof HVAC approach and other equipment combinations, where both desiccant and conventional systems are modeled to provide comparable fresh air ventilation rates and indoor humidity levels. The results obtained from these simulations demonstrate convincingly the energy and operating cost savings obtainable with this hybrid desiccant/vapor-compression technology, verifying those actually seen at the pilot installations. The ADM approach is less expensive than conventional alternatives providing similar performance and indoor air quality and provides a very favorable payback (1 year or so) compared with oversized rooftop units that cannot be operated effectively with the necessary high outdoor air percentages.

Fischer, J

2004-03-15T23:59:59.000Z

242

Modeling Coupled Evaporation and Seepage in Ventilated Cavities  

SciTech Connect

Cavities excavated in unsaturated geological formations are important to activities such as nuclear waste disposal and mining. Such cavities provide a unique setting for simultaneous occurrence of seepage and evaporation. Previously, inverse numerical modeling of field liquid-release tests and associated seepage into cavities were used to provide seepage-related large-scale formation properties by ignoring the impact of evaporation. The applicability of such models was limited to the narrow range of ventilation conditions under which the models were calibrated. The objective of this study was to alleviate this limitation by incorporating evaporation into the seepage models. We modeled evaporation as an isothermal vapor diffusion process. The semi-physical model accounts for the relative humidity, temperature, and ventilation conditions of the cavities. The evaporation boundary layer thickness (BLT) over which diffusion occurs was estimated by calibration against free-water evaporation data collected inside the experimental cavities. The estimated values of BLT were 5 to 7 mm for the open underground drifts and 20 mm for niches closed off by bulkheads. Compared to previous models that neglected the effect of evaporation, this new approach showed significant improvement in capturing seepage fluctuations into open cavities of low relative humidity. At high relative-humidity values (greater than 85%), the effect of evaporation on seepage was very small.

T. Ghezzehei; R. Trautz; S. Finsterle; P. Cook; C. Ahlers

2004-07-01T23:59:59.000Z

243

Steam compression with inner evaporative spray cooling: a case study  

Science Conference Proceedings (OSTI)

An adiabatic dry saturated steam compression process with inner evaporative spray cooling in screw compressors for steam heat pump systems is studied. Thermodynamic model and simulation of this variable-mass compression process are devised. Differential ... Keywords: inner evaporative spray cooling, screw compressors, simulation, steam compression, steam heat pumps, thermodynamic modelling, variable-mass compression, water injection

Jian Qui; Zhaolin Gu; Guoguang Cai

2004-12-01T23:59:59.000Z

244

Energy and economic performance analysis of an open cycle solar desiccant dehumidification air-conditioning system for application in Hong Kong  

Science Conference Proceedings (OSTI)

In this article, a transient simulation model and the EnergyPlus were used to study the energy performance and economical feasibility for integrating a solar liquid desiccant dehumidification system with a conventional vapor compression air-conditioning system for the weather condition of Hong Kong. The vapor compression system capacity in the solar assisted air-conditioning system can be reduced to 19 kW from original 28 kW of a conventional air-conditioning system as a case study due to the solar desiccant cooling. The economical performance of the solar desiccant dehumidification system is compared with that of the conventional air-conditioning system. The results show that the energy saving potentials due to incorporation of the solar desiccant dehumidification system in a traditional air-conditioning system is significant for the hot wet weather in Hong Kong due to higher COP resulted from higher supply chilled water temperature from chiller plants. The annual operation energy savings for the hybrid system is 6760 kWh and the payback period of the hybrid system is around 7 years. The study shows that the solar assisted air-conditioning is a viable technology for utilizations in subtropical areas. (author)

Li, Yutong; Lu, Lin; Yang, Hongxing [Renewable Energy Research Group (RERG), Department of Building Services Engineering, Hong Kong Polytechnic University, Hung Hom (China)

2010-12-15T23:59:59.000Z

245

Disk evaporation in a planetary nebula  

E-Print Network (OSTI)

We study the Galactic bulge planetary nebula M 2-29 (for which a 3-year eclipse event of the central star has been attributed to a dust disk) using HST imaging and VLT spectroscopy, both long-slit and integral field. The central cavity of M 2-29 is filled with a decreasing, slow wind. An inner high density core is detected, with radius less than 250 AU, interpreted as a rotating gas/dust disk with a bipolar disk wind. The evaporating disk is argued to be the source of the slow wind. The central star is a source of a very fast wind (1000 km/s). An outer, partial ring is seen in the equatorial plane, expanding at 12 km/s. The azimuthal asymmetry is attributed to mass-loss modulation by an eccentric binary. M 2-29 presents a crucial point in disk evolution, where ionization causes the gas to be lost, leaving a low-mass dust disk behind.

Gesicki, K; Szyszka, C; Hajduk, M; Lagadec, E; Ramirez, L Guzman

2010-01-01T23:59:59.000Z

246

The Importance of Spring and Autumn Atmospheric Conditions for the Evaporation Regime of Lake Superior  

Science Conference Proceedings (OSTI)

Feedbacks between ice extent and evaporation have long been suspected to be important for Lake Superior evaporation because it is during autumn and winter when latent heat fluxes are highest. Recent direct measurements of evaporation made at the ...

C. Spence; P. D. Blanken; J. D. Lenters; N. Hedstrom

247

Toward a Robust Phenomenological Expression of Evaporation Efficiency for Unsaturated Soil Surfaces  

Science Conference Proceedings (OSTI)

The evaporation rates of water from several soil types were measured under controlled conditions. When the layer of soil is sufficiently thin, the evaporation efficiency ?, the ratio of the evaporation rate from the soil surface relative to that ...

Teruhisa S. Komatsu

2003-09-01T23:59:59.000Z

248

The Importance of Spring and Autumn Atmospheric Conditions for the Evaporation Regime of Lake Superior  

Science Conference Proceedings (OSTI)

Feedbacks between ice extent and evaporation have long been suspected to be important for Lake Superior evaporation because it is during autumn and winter when latent heat fluxes are highest. Recent direct measurements of evaporation made at the ...

C. Spence; P. D. Blanken; J. D. Lenters; N. Hedstrom

2013-10-01T23:59:59.000Z

249

A Self-consistent Model of the Black Hole Evaporation  

E-Print Network (OSTI)

We construct a self-consistent model which describes a black hole from formation to evaporation including the back reaction from the Hawking radiation. In the case where a null shell collapses, at the beginning the evaporation occurs, but it stops eventually, and a horizon and singularity appear. On the other hand, in the generic collapse process of a continuously distributed null matter, the black hole evaporates completely without forming a macroscopically large horizon nor singularity. We also find a stationary solution in the heat bath, which can be regarded as a normal thermodynamic object.

Hikaru Kawai; Yoshinori Matsuo; Yuki Yokokura

2013-02-19T23:59:59.000Z

250

Development of a solar desiccant dehumidifier. Volume 1. Summary. Volume 2. Detailed technical information. Technical progress report  

DOE Green Energy (OSTI)

Research and development work aimed at the development of a solar desiccant dehumidifier is described in detail. The system features a rotary bed of granular silica gel and a rotary regenerator. The dehumidifier can be used for air conditioning through adiabatic saturation of the process airstream. Detailed technical information is presented in the appendices: (A) management, (B) review of the literature: state-of-the-art survey and SERI meeting, (C) review of the literature: adsorbent survey, (D) design requirements and evaluation criteria, (E) design requirements and evaluation criteria, single-family house model, (F) design requirements and evaluation criteria, economic model, (G) design requirements and evaluation criteria: conventional system models for comparison, (H) candidate cooling subsystems, (I) subsystem computer model, (J) subsystem performance map, and (K) subsystem preliminary design. (WHK)

Gunderson, M.E.; Hwang, K.C.; Railing, S.M.

1978-03-31T23:59:59.000Z

251

Retrofitting of Conditioning Systems for Existing Small Commercial Buildings - Analysis and Design of Liquid Desiccant - Vapor Compression Hybrid  

E-Print Network (OSTI)

The combination of several concepts of new energy technologies may make it possible to reduce the energy needs for thermal comfort, especially cooling and dehumidification, in small sized, single-story commercial buildings. The potentials and limitations of retrofit technology for these characteristic structures have been the focus of the experience gained through the design and installation of a system adapted to a building constructed in the early 1960's. The existing split package air conditioning system was combined with a desiccant air-conditioning unit with a waste heat and solar heat reclaim component. While this retrofit system is feasible, a number of questions remain to be considered regarding the design, installation and operation of the total system. This paper focuses on the practical applications of such a hybrid system - both architectural/construction issues and the mechanical components/system considerations.

Arnas, O. A.; McQueen, T. M.

1984-01-01T23:59:59.000Z

252

DOE - Office of Legacy Management -- Swenson Evaporator Co - IL 23  

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

Swenson Evaporator Co - IL 23 Swenson Evaporator Co - IL 23 FUSRAP Considered Sites Site: SWENSON EVAPORATOR CO. (IL.23 ) Eliminated from further consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Harvey , Illinois IL.23-1 Evaluation Year: 1987 IL.23-1 Site Operations: Scheduled a raffinate spray drying test that was later cancelled. IL.23-1 Site Disposition: Eliminated - No indication that radioactive materials were handled at this site IL.23-1 Radioactive Materials Handled: None Indicated Primary Radioactive Materials Handled: None Radiological Survey(s): None Indicated Site Status: Eliminated from further consideration under FUSRAP Also see Documents Related to SWENSON EVAPORATOR CO. IL.23-1 - Memorandum/Checklist; D.Levine to the File; Subject:

253

Monitoring Free-Water Evaporation at Automated Weather Stations  

Science Conference Proceedings (OSTI)

The automation of weather stations necessitates an alternative approach to the traditional manual measure of free-water evaporation made using a class A pan. This study compared commercially available water-level sensing transducers mounted on ...

S. M. McGinn; H. D. J. McLean

1995-12-01T23:59:59.000Z

254

Decadal Trends in Evaporation from Global Energy and Water Balances  

Science Conference Proceedings (OSTI)

Satellite and gridded meteorological data can be used to estimate evaporation (E) from land surfaces using simple diagnostic models. Two satellite datasets indicate a positive trend (first time derivative) in global available energy from 1983 to ...

Yongqiang Zhang; Ray Leuning; Francis H. S. Chiew; Enli Wang; Lu Zhang; Changming Liu; Fubao Sun; Murray C. Peel; Yanjun Shen; Martin Jung

2012-02-01T23:59:59.000Z

255

Arctic Precipitation and Evaporation: Model Results and Observational Estimates  

Science Conference Proceedings (OSTI)

Observational estimates of precipitation and evaporation over the Arctic Ocean and its terrestrial watersheds are compared with corresponding values from the climate model simulations of the Atmospheric Model Intercomparison Project (AMIP). ...

John E. Walsh; Vladimir Kattsov; Diane Portis; Valentin Meleshko

1998-01-01T23:59:59.000Z

256

Correcting Microwave Precipitation Retrievals for near-Surface Evaporation  

E-Print Network (OSTI)

This paper compares two methods for correcting passive or active microwave surface precipitation estimates based on hydrometeors sensed aloft that may evaporate before landing. These corrections were derived using two years ...

Surussavadee, Chinnawat

257

Potential Evaporation and Soil Moisture in General Circulation Models  

Science Conference Proceedings (OSTI)

The parameterization of continental evaporation in many atmospheric general circulation models (GCMS) used for simulation of climate is demonstrably inconsistent with the empirical work upon which the parameterization is based. In the turbulent ...

P. C. D. Milly

1992-03-01T23:59:59.000Z

258

Evaporation of Nonequilibrium Raindrops as a Fog Formation Mechanism  

Science Conference Proceedings (OSTI)

To gain insights into the poorly understood phenomenon of precipitation fog, this study assesses the evaporation of freely falling drops departing from equilibrium as a possible contributing factor to fog formation in rainy conditions. The study ...

Robert Tardif; Roy M. Rasmussen

2010-02-01T23:59:59.000Z

259

Removal of Sulfate Ion From AN-107 by Evaporation  

Science Conference Proceedings (OSTI)

Hanford low-activity waste solutions contain sulfate, which can cause accelerated corrosion of the vitrification melter and unacceptable operating conditions. A method is needed to selectively separate sulfate from the waste. An experiment was conducted to evaluate evaporation for removing sulfate ion from Tank AN-107 low-activity waste. Two evaporation steps were performed. In the first step, the volume was reduced by 55% while in the second step, the liquid volume was reduced another 22%. Analysis of the solids precipitated during these evaporations revealed that large amounts of sodium nitrate and nitrite co-precipitated with sodium sulfate. Many other waste components precipitated as well. It can be concluded that sulfate removal by precipitation is not selective, and thus, evaporation is not a viable option for removing sulfate from the AN-107 liquid.

GJ Lumetta; GS Klinger; DE Kurath; RL Sell; LP Darnell; LR Greenwood; CZ Soderquist; MJ Steele; MW Urie; JJ Wagner

2000-08-02T23:59:59.000Z

260

Spacetime Structure of an Evaporating Black Hole in Quantum Gravity  

E-Print Network (OSTI)

The impact of the leading quantum gravity effects on the dynamics of the Hawking evaporation process of a black hole is investigated. Its spacetime structure is described by a renormalization group improved Vaidya metric. Its event horizon, apparent horizon, and timelike limit surface are obtained taking the scale dependence of Newton's constant into account. The emergence of a quantum ergosphere is discussed. The final state of the evaporation process is a cold, Planck size remnant.

Bonanno, A

2006-01-01T23:59:59.000Z

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to obtain the most current and comprehensive results.


261

NWCF Evaporator Tank System 2001 Offgas Emissions Inventory  

SciTech Connect

An offgas emissions inventory and liquid stream characterization of the Idaho New Waste Calcining Facility (NWCF) Evaporator Tank System (ETS), formerly known as the High Level Liquid Waste Evaporator (HLLWE), has been completed. The emissions rates of volatile and semi-volatile organic compounds, multiple metals, particulate, and hydrochloric acid were measured in accordance with an approved Quality Assurance Project Plan (QAPjP) and Test Plan that invoked U.S. Environmental Protection Agency (EPA) standard sample collection and analysis procedures. Offgas samples were collected during the start up and at the end of evaporator batches when it was hypothesized the emissions would be at peak rates. Corresponding collection of samples from the evaporator feed overhead condensate, and bottoms was made at approximately the same time as the emissions inventory to support material balance determinations for the evaporator process. The data indicate that organic compound emissions are slightly higher at the beginning of the batch while metals emissions, including mercury, are slightly higher at the end of the evaporator batch. The maximum emissions concentrations are low for all constituents of primary concern. Mercury emissions were less than 5 ppbv, while the sum of HCl and Cl2 emissions was less than 1 ppmv. The sum of all organic emissions also was less than 1 ppmv. The estimated hazardous quotient (HQ) for the evaporator was 6.2e-6 as compared to 0.25 for the EPA target criteria. The cancer risk was 1.3e-10 compared to an EPA target of le-5.

Boardman, R.D.; Lamb, K.M.; Matejka, L.A.; Nenni, J.A.

2002-02-27T23:59:59.000Z

262

NWCF Evaporator Tank System 2001 Offgas Emissions Inventory  

SciTech Connect

An offgas emissions inventory and liquid stream characterization of the Idaho New Waste Calcining Facility (NWCF) Evaporator Tank System (ETS), formerly known as the High Level Liquid Waste Evaporator (HLLWE), has been completed. The emissions rates of volatile and semi-volatile organic compounds, multiple metals, particulate, and hydrochloric acid were measured in accordance with an approved Quality Assurance Project Plan (QAPjP) and Test Plan that invoked U.S. Environmental Protection Agency (EPA) standard sample collection and analysis procedures. Offgas samples were collected during the start up and at the end of evaporator batches when it was hypothesized the emissions would be at peak rates. Corresponding collection of samples from the evaporator feed overhead condensate, and bottoms was made at approximately the same time as the emissions inventory to support material balance determinations for the evaporator process. The data indicate that organic compound emissions are slightly higher at the beginning of the batch while metals emissions, including mercury, are slightly higher at the end of the evaporator batch. The maximum emissions concentrations are low for all constituents of primary concern. Mercury emissions were less than 5 ppbv, while the sum of HCl and Cl2 emissions was less than 1 ppmv. The sum of all organic emissions also was less than 1 ppmv. The estimated hazardous quotient (HQ) for the evaporator was 6.2e-6 as compared to 0.25 for the EPA target criteria. The cancer risk was 1.3e-10 compared to an EPA target of le-5.

Boardman, Richard Doin; Lamb, Kenneth Mitchel; Matejka, Leon Anthony; Nenni, Joseph A

2002-02-01T23:59:59.000Z

263

Analysis of the adsorption process and of desiccant cooling systems: a pseudo- steady-state model for coupled heat and mass transfer. [DESSIM, DESSIM2, DESSIM4  

DOE Green Energy (OSTI)

A computer model to simulate the adiabatic adsorption/desorption process is documented. Developed to predict the performance of desiccant cooling systems, the model has been validated through comparison with experimental data for single-blow adsorption and desorption. A literature review on adsorption analysis, detailed discussions of the adsorption process, and an initial assessment of the potential for performance improvement through advanced component development are included.

Barlow, R.S.

1982-12-01T23:59:59.000Z

264

Open cycle liquid desiccant dehumidifier and hybrid solar/electric absorption refrigeration system. Annual report, January 1993--December 1993. Calendar year 1993  

DOE Green Energy (OSTI)

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

265

Field Test and Performance Verification: Integrated Active Desiccant Rooftop Hybrid System Installed in a School - Final Report: Phase 4A  

SciTech Connect

This report summarizes the results of a field verification pilot site investigation that involved the installation of a hybrid integrated active desiccant/vapor-compression rooftop heating, ventilation, and air-conditioning (HVAC) unit at an elementary school in the Atlanta Georgia area. For years, the school had experienced serious humidity and indoor air quality (IAQ) problems that had resulted in occupant complaints and microbial (mold) remediation. The outdoor air louvers of the original HVAC units had been closed in an attempt to improve humidity control within the space. The existing vapor compression variable air volume system was replaced by the integrated active desiccant rooftop (IADR) system that was described in detail in an Oak Ridge National Laboratory (ORNL) report published in 2004 (Fischer and Sand 2004). The IADR system and all space conditions have been monitored remotely for more than a year. The hybrid system was able to maintain both the space temperature and humidity as desired while delivering the outdoor air ventilation rate required by American Society of Heating, Refrigerating and Air-Conditioning Engineers Standard 62. The performance level of the IADR unit and the overall system energy efficiency was measured and found to be very high. A comprehensive IAQ investigation was completed by the Georgia Tech Research Institute before and after the system retrofit. Before-and-after data resulting from this investigation confirmed a significant improvement in IAQ, humidity control, and occupant comfort. These observations were reported by building occupants and are echoed in a letter to ORNL from the school district energy manager. The IADR system was easily retrofitted in place of the original rooftop system using a custom curb adapter. All work was completed in-house by the school's maintenance staff over one weekend. A subsequent cost analysis completed for the school district by the design engineer of record concluded that the IADR system being investigated was actually less expensive to install than other less-efficient options, most of which were unable to deliver the required ventilation while maintaining the desired space humidity levels.

Fischer, J

2005-12-21T23:59:59.000Z

266

Evaporative Roof Cooling - A Simple Solution to Cut Cooling Costs  

E-Print Network (OSTI)

Since the "Energy Crisis" Evaporative Roof Cooling Systems have gained increased acceptance as a cost effective method to reduce the high cost of air conditioning. Documented case histories in retrofit installations show direct energy savings and paybacks from twelve to thirty months. The main operating cost of an Evaporative Roof Cooling System is water. One thousand gallons of water, completely evaporated, will produce over 700 tons of cooling capability. Water usage seldom averages over 100 gallons per 1000 ft^2 of roof area per day or 10 oz. of water per 100 ft^2 every six minutes. Roof Cooling Systems, when planned in new construction, return 1-1/2 times the investment the first year in equipment savings and operating costs. Roof sprays are a low cost cooling solution for warehouses, distribution centers and light manufacturing or assembly areas with light internal loads. See text "Flywheel Cooling."

Abernethy, D.

1985-01-01T23:59:59.000Z

267

Development of a Direct Evaporator for the Organic Rankine Cycle  

Science Conference Proceedings (OSTI)

This paper describes research and development currently underway to place the evaporator of an Organic Rankine Cycle (ORC) system directly in the path of a hot exhaust stream produced by a gas turbine engine. The main goal of this research effort is to improve cycle efficiency and cost by eliminating the usual secondary heat transfer loop. The project’s technical objective is to eliminate the pumps, heat exchangers and all other added cost and complexity of the secondary loop by developing an evaporator that resides in the waste heat stream, yet virtually eliminates the risk of a working fluid leakage into the gaseous exhaust stream. The research team comprised of Idaho National Laboratory and General Electric Company engineers leverages previous research in advanced ORC technology to develop a new direct evaporator design that will reduce the ORC system cost by up to 15%, enabling the rapid adoption of ORCs for waste heat recovery.

Donna Post Guillen; Helge Klockow; Matthew Lehar; Sebastian Freund; Jennifer Jackson

2011-02-01T23:59:59.000Z

268

Open cycle OTEC system with falling jet evaporator and condenser  

DOE Green Energy (OSTI)

A configuration for the open cycle (OC) Ocean Thermal Energy Conversion (OTEC) system is presented incorporating a countercurrent falling jet evaporator and a concurrent falling jet condenser. The parameters governing performance of the proposed configuration are discussed and the sizing of equipment for a 100-MWe net power output OC OTEC plant is performed, based on recent experimental falling jet heat and mass transfer results. The performance of an OC OTEC plant with falling jet evaporator-condenser is compared with the Westinghouse conceptual design that uses an open-channel evaporator and a surface condenser. Preliminary calculations indicate that falling jet heat and mass transfer, when applied in the proposed configuration, leads to a very simple and compact plant assembly resulting in substantial capital cost savings.

Kogan, A.; Johnson, D. H.; Green, H. J.; Olson, D. A.

1980-07-01T23:59:59.000Z

269

Classical black hole evaporation in Randall-Sundrum infinite braneworld  

E-Print Network (OSTI)

After the gravity induced on the brane in the Randall-Sundrum (RS) infinite braneworld is briefly reviewed, we discuss the possibility that black holes evaporate as a result of classical evolution in this model based on the AdS/CFT correspondence. If this possibility is really the case, the existence of long-lived solar mass black holes will give the strongest constraint on the bulk curvature radius. At the same time, we can propose a new method to simulate the evaporation of a 4D black hole due to the Hawking radiation as a 5D process.

Takahiro Tanaka

2002-03-24T23:59:59.000Z

270

Silicon Isotopic Fractionation of CAI-like Vacuum Evaporation Residues  

SciTech Connect

Calcium-, aluminum-rich inclusions (CAIs) are often enriched in the heavy isotopes of magnesium and silicon relative to bulk solar system materials. It is likely that these isotopic enrichments resulted from evaporative mass loss of magnesium and silicon from early solar system condensates while they were molten during one or more high-temperature reheating events. Quantitative interpretation of these enrichments requires laboratory determinations of the evaporation kinetics and associated isotopic fractionation effects for these elements. The experimental data for the kinetics of evaporation of magnesium and silicon and the evaporative isotopic fractionation of magnesium is reasonably complete for Type B CAI liquids (Richter et al., 2002, 2007a). However, the isotopic fractionation factor for silicon evaporating from such liquids has not been as extensively studied. Here we report new ion microprobe silicon isotopic measurements of residual glass from partial evaporation of Type B CAI liquids into vacuum. The silicon isotopic fractionation is reported as a kinetic fractionation factor, {alpha}{sub Si}, corresponding to the ratio of the silicon isotopic composition of the evaporation flux to that of the residual silicate liquid. For CAI-like melts, we find that {alpha}{sub Si} = 0.98985 {+-} 0.00044 (2{sigma}) for {sup 29}Si/{sup 28}Si with no resolvable variation with temperature over the temperature range of the experiments, 1600-1900 C. This value is different from what has been reported for evaporation of liquid Mg{sub 2}SiO{sub 4} (Davis et al., 1990) and of a melt with CI chondritic proportions of the major elements (Wang et al., 2001). There appears to be some compositional control on {alpha}{sub Si}, whereas no compositional effects have been reported for {alpha}{sub Mg}. We use the values of {alpha}Si and {alpha}Mg, to calculate the chemical compositions of the unevaporated precursors of a number of isotopically fractionated CAIs from CV chondrites whose chemical compositions and magnesium and silicon isotopic compositions have been previously measured.

Knight, K; Kita, N; Mendybaev, R; Richter, F; Davis, A; Valley, J

2009-06-18T23:59:59.000Z

271

Simultaneous multiparticle emissions in hot nuclei evaporation process  

SciTech Connect

This work presents a new mechanism for the evaporation with simultaneous particles emission mechanism in the evaporation chain as new channels opened to high excitation energy regime of the compound nucleus. The probability of multiple simultaneous emissions is determined based on phase space approach. A Monte Carlo simulation is employed to compute the final average yield of emitted particles after the decay chain. The neutron, proton, alpha and fission yields are obtained and compared to the conventional calculation with sequential simple particles emission and the relevance of the different channels in competition is also analyzed.

Santos, B. M. [Instituto de Fisica - Universidade Federal Fluminense Av. Gal. Milton Tavares de Souza, 24210-346 Niteroi. RJ (Brazil); De Assis, L. P.; Duarte, S. B. [Centro Brasileiro de Pesquisas Fisicas - CBPF Rua Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro. RJ (Brazil)

2013-03-25T23:59:59.000Z

272

Simulation of Diffusive Lithium Evaporation Onto the NSTX Vessel Walls  

Science Conference Proceedings (OSTI)

A model for simulating the diffusive evaporation of lithium into a helium filled NSTX vacuum vessel is described and validated against an initial set of deposition experiments. The DEGAS 2 based model consists of a three-dimensional representation of the vacuum vessel, the elastic scattering process, and a kinetic description of the evaporated atoms. Additional assumptions are required to account for deuterium out-gassing during the validation experiments. The model agrees with the data over a range of pressures to within the estimated uncertainties. Suggestions are made for more discriminating experiments that will lead to an improved model.

D.P. Stotler, C.H. Skinner, W.R. Blanchard, P.S. Krstic, H.W. Kugel, H. Schneider, and L.E. Zakharov

2010-12-09T23:59:59.000Z

273

Experimental study of the performance of a laminar flow silica gel desiccant packing suitable for solar air conditioning application  

DOE Green Energy (OSTI)

An experimental study of the performance of a low pressure drop silica gel desiccant packing has been carried out. The packing is in the form of narrow passages lined with a single layer of small silica gel particles. A near optimum particle size of 0.25 mm, and a range of passage widths of 1.46 to 3.75 mm were chosen based on the predictions of a computer simulation model. A test chamber was constructed with sufficient thermal insulation to allow close to adiabatic conditions for the 12 cm x 12 cm cross section of packing. Step change adsorption and desorption tests were performed for various plate spacings, air flow rates, air inlet conditions, and gel initial water contents. Air outlet moisture content and temperature, as well as pressure drop were measured. The experimental results were compared with predictions of the computer simulation model: This model is based on gas side controlled heat and mass transfer, with the small solid side mass transfer resistance incorporated in a crude manner, and heat transfer into the packing handled as a lumped thermal capacitance. Reasonable agreement was obtained between theoretical prediction and experiment. The match was found to improve with increased passage width. The discrepancies are chiefly attributed to an excessive air bypass, and to inaccurate accounting for heat transfer from the sides of the unit. Use of the computer code for prototype scale design purposes is recommended.

Biswas, P.

1983-02-01T23:59:59.000Z

274

Process Control Plan for 242A Evaporator Campaign  

SciTech Connect

The wastes in tanks 107-AP and 108-AP are designated as feed for 242-A Evaporator Campaign 2000-1, which is currently scheduled for the week of April 17, 2000. Waste in tanks 107-AP and 108-AP is predominantly comprised of saltwell liquor from 200 West Tank Farms.

LE, E.Q.

2000-04-06T23:59:59.000Z

275

Laboratory Measurements of Particle Capture by Evaporating Cloud Drops  

Science Conference Proceedings (OSTI)

The capture efficiencies of evaporating cloud drops (56–93 ?m radius) for particles of manganese hypophosphite (0.58–3.2 ?m radius) were obtained experimentally. In each experimental run, a large number of widely spaced uniform size drops fell ...

K. H. Leong; K. V. Beard; Harry T. Ochs III

1982-05-01T23:59:59.000Z

276

Low-Cost Wind Speed Measurements Using Naphthalene Evaporation  

Science Conference Proceedings (OSTI)

Six 125-cm3 metal mesh cages, filled with 99% pure naphthalene mothballs, were suspended near anemometers during 8 winter weeks. Each week the cages were weighed to determine how much evaporation had occurred. A least-squares linear regression of ...

Pierre Y. Bernier

1988-10-01T23:59:59.000Z

277

Restart oversight assessment of Hanford 242-A evaporator: Technical report  

SciTech Connect

An assessment team from the Office of Environment, Safety and Health (EH), US Department of Energy (DOE), conducted an independent assessment of the 242-A Evaporator at the Hanford Site during January 17--28, 1994. An EH team member remained on-site following the assessment to track corrective actions and resolve prestart findings. The primary objective of this assessment was independent assurance that the DOE Office of Environmental Management (EM), the DOE Richland Operations Office (DOE-RL), and Westinghouse Hanford Company (WHC) can safely restart the evaporator. Another objective of the EH team was to assess EM`s Operational Readiness Evaluation (ORE) to determine if the programs, procedures, and management systems implemented for operation of the 241-A Evaporator ensure the protection of worker safety and health. The following section of this report provides background information on the 242-A Evaporator and Operational Readiness Review (ORR) activities conducted to date. The next chapter is divided into sections that address the results of discrete assessment activities. Each section includes a brief statement of conclusions for the functional area in question, descriptions of the review bases and methods, and a detailed discussion of the results. Concerns identified during the assessment are listed for the section to which they apply, and the specific findings upon which the concern is based can be found immediately thereafter.

Lagdon, R.; Lasky, R.

1994-08-01T23:59:59.000Z

278

Applications of Mechanical Vapor Recompression to Evaporation and Crystallization  

E-Print Network (OSTI)

Over the past 10-15 years, mechanical vapor recompression (MVR) has become the preferred system in many industrial evaporation and crystallization applications, because of its economy and simplicity of operation. In most instances, the need for steam to provide heat for the evaporation and cooling water for condensing the overhead vapors is virtually eliminated; and, at the same time, a wide range of turndown is available. An MVR is generally found to be the most economical choice when there is no boiler plant available or when electrical power is priced competitively in comparison to steam. Vapor recompression is accomplished using centrifugal, axial-flow, or positive displacement compressors and these compressors can be powered by electricity, steam turbine or a gas turbine. The use of an MVR Evaporator/Crystallizer provides a comparatively low cost means of expanding the production capability of an existing evaporation plant either by adding a "stand alone" unit or by reconfiguring a multiple-effect system into several single-effect MVR's.

Outland, J. S.

1995-04-01T23:59:59.000Z

279

Is Virga Rain That Evaporates before Reaching the Ground?  

Science Conference Proceedings (OSTI)

The visual phenomenon called virga, a sudden change in the brightness of a precipitation shaft below a cloud, is commonly attributed to evaporation of raindrops. It is said to be rain that does not reach the ground. The optical thickness of an ...

Alistair B. Fraser; Craig F. Bohren

1992-08-01T23:59:59.000Z

280

Evaporation of iodine-containing off-gas scrubber solution  

DOE Patents (OSTI)

Mercuric nitrate-nitric acid scrub solutions containing radioiodine may be reduced in volume without excessive loss of volatile iodine. The use of concentrated nitric acid during an evaporation process oxidizes the mercury-iodide complex to a less volatile mercuric iodate precipitate.

Partridge, J.A.; Bosuego, G.P.

1980-07-14T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

Passive cooling with solar updraft and evaporative downdraft chimneys  

DOE Green Energy (OSTI)

Computer models have been developed to describe the operation of both solar updraft and evaporative downdraft chimneys. Design studies are being conducted at the present time to use the towers for cooling an experimental, well instrumented, structure to study passive cooling in residential buildings. (MHR)

Mignon, G.V.; Cunningham, W.A.; Thompson, T.L.

1985-01-01T23:59:59.000Z

282

A Parameterization of Evaporation from Bare Soil Surfaces  

Science Conference Proceedings (OSTI)

A simple model of evaporation from a bare soil surface is developed. This model combines two processes of water vapor transport: one is the vapor transport in air expressed by the bulk formula, and the other is molecular diffusion of vapor in the ...

Junsei Kondo; Nobuko Saigusa; Takeshi Sato

1990-05-01T23:59:59.000Z

283

Nanotube Boiler 1 Abstract--Controlled copper evaporation at attogram  

E-Print Network (OSTI)

Nanotube Boiler 1 Abstract-- Controlled copper evaporation at attogram level from individual carbon nanotube (CNT) vessels, which we call nanotube boilers, is investigated experimentally, and ionization in these CNT boilers, which can serve as sources for mass transport and deposition in nanofluidic

Paris-Sud XI, Université de

284

Analysis of design tradeoffs for diplay case evaporators  

SciTech Connect

A model for simulating a display case evaporator under frosting conditions has been developed, using a quasi-steady and finite-volume approach and a Newton-Raphson based solution algorithm. It is capable of simulating evaporators with multiple modules having different geometries, e.g. tube and fin thicknesses and pitch. The model was validated against data taken at two-minute intervals from a well-instrumented medium-temperature vertical display case, for two evaporators having very different configurations. The data from these experiments provided both the input data for the model and also the data to compare the modeling results. The validated model has been used to generate some general guidelines for coil design. Effects of various geometrical parameters were quantified, and compressor performance data were used to express the results in terms of total power consumption. Using these general guidelines, a new prototype evaporator was designed for the subject display case, keeping in mind the current packaging restrictions, tube and fin availabilities. It is an optimum coil for the given external load conditions. Subsequently, the validated model was used in a more extensive analysis to design prototype coils with some of the current tube and fin spacing restrictions removed. A new microchannel based suction line heat exchanger was installed in the display case system. The performance of this suction line heat exchanger is reported.

Bullard, CLARK

2004-08-11T23:59:59.000Z

285

3D Imaging of Evaporating Fuel Droplets by Stereoscopic PIV  

Science Conference Proceedings (OSTI)

A gun-type burner is a widely used oil burner for industrial and domestic applications. The oil is pressure-atomized and mixed with air generating a recirculating, swirling flow. Because of the surrounding flame, fuel droplets evaporate, being difficult ... Keywords: 3D PIV, Stereoscopic PIV, droplet dynamics, spray combustion

V. Palero; Y. Ikeda

2002-08-01T23:59:59.000Z

286

Radiation-induced changes in the cuticular hydrocarbons of the granary weevil and their relationship to desiccation and adult mortality  

Science Conference Proceedings (OSTI)

Radiation from the nuclear waste products, such as Cesium-137, offers a scope and could be used for large scale disinfestation of grain. It is known that 0.15 to 0.20 kGy dose of gamma radiation is sufficient to kill insects in grain and grain products. However, the mode of action (in terms of lethal effects) is not understood. The purpose of this project, therefore, is to study the ways in which gamma radiation causes death in the granary weevil. Sitophilus granarius (L.) is a major and cosmopolitan pest of stored grain all over the world. Radiation damage, in particular the specific effects on the physiology of the insects exposed to radiation has been elucidated. In stored grain insects, conservation of water is a critical factor for their survival. Epicuticular hydrocarbons play an important role in water proofing. The laboratory rearing of the granary weevil was standardized so that large numbers of weevils of known ages could be produced for experimentation. Stock cultures were maintained at 27 {plus minus} 2{degree}C and 65 {plus minus} 5% R.H. Tests with various age groups (adults) and different doses of gamma radiation indicate that lethal effects are both age and dose related. Younger weevils, in general, survive for a longer period after irradiation compared to older weevils. Complete mortality results within about two weeks after exposure to gamma radiation at dose of 0.15 kGy or above. Data on wet and dry weights of the weevils kept at different (low, medium and higher) levels of humidity after irradiation indicate that gamma radiation induces greater water loss leading to desiccation and early death. Low humidity environment (17% R.H.) greatly accelerates lethal effects.

Sriharan, S. (Selma Univ., AL (USA). Div. of Natural and Applied Sciences)

1989-07-01T23:59:59.000Z

287

Catalyst free growth of ZnO nanorods by thermal evaporation method  

SciTech Connect

In this work, we report catalyst free growth of ZnO nanorods on n-Si substrate by a low cost thermal evaporation method. The surface morphology, chemical composition and crystalline structure of ZnO nanorods have been determined by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) spectroscopy respectively. It is found that, the as -deposited ZnO seed layer reduces lattice mismatching between ZnO and Si from 40.3 to 0.28%, therefore enhances the subsequent growth and crystalline quality of ZnO nanorods on Si substrate. The present methodology is simple, cost effective and highly applicable for synthesis of ZnO nanorods for optoelectronics applications.

Somvanshi, Divya; Jit, S. [Centre for Research in Microelectronics (CRME), Department of Electronics Engineering Indian Institute of Technology (Banaras Hindu University), Varanasi Uttar Pradesh-221005 (India)

2013-06-03T23:59:59.000Z

288

Reconstruction of a Daily Large-Pan Evaporation Dataset over China  

Science Conference Proceedings (OSTI)

Land surface evaporation is an important component of the earth’s surface hydrological cycle, as well as in the atmospheric energy and water balances. In China, different instruments have been used over time to measure evaporation. A small pan ...

An-Yuan Xiong; Jie Liao; Bin Xu

2012-07-01T23:59:59.000Z

289

Evaporation-Limited Tropical Temperatures as a Constraint on Climate Sensitivity  

Science Conference Proceedings (OSTI)

Studies of paleoclimate and modern observations indicate that evaporative effects limit thermal response in equatorial regions. We develop a latitude-resolved, steady-state energy balance model which incorporates the effect of an evaporative ...

Martin I. Hoffert; Brian P. Flannery; Andrew J. Callegari; C. T. Hsieh; Warren Wiscombe

1983-07-01T23:59:59.000Z

290

Modeling the Hydroclimatology of Kuwait: The Role of Subcloud Evaporation in Semiarid Climates  

Science Conference Proceedings (OSTI)

A new subcloud layer evaporation scheme is incorporated into Regional Climate Model, version 3 (RegCM3), to better simulate the rainfall distribution over a semiarid region around Kuwait. The new scheme represents subcloud layer evaporation of ...

Marc P. Marcella; Elfatih A. B. Eltahir

2008-06-01T23:59:59.000Z

291

A Simple Model of Evaporatively Driven Dowadraft: Application to Microburst Downdraft  

Science Conference Proceedings (OSTI)

A simple one-dimensional, time-dependent model of an evaporatively driven downdraft is presented. The model is described by equations for raindrop evaporation, raindrop concentration, water substance, thermodynamic energy and vertical air ...

R. C. Srivastava

1985-05-01T23:59:59.000Z

292

A Rapid-Circulation Evaporation Chamber for Measuring Bulk Stomatal Resistance  

Science Conference Proceedings (OSTI)

A relatively simple method is described for determining evaporation of short vegetation at any moment of time. The method is based on the measurement of bulk stomatal resistance of the crop with an evaporation chamber. Once this quantity is known,...

W. Kohsiek

1981-01-01T23:59:59.000Z

293

Wind Run Changes: The Dominant Factor Affecting Pan Evaporation Trends in Australia  

Science Conference Proceedings (OSTI)

The Class A pan evaporation rates at many Australian observing stations have reportedly decreased between 1970 and 2002. That pan evaporation rates have decreased at the same time that temperatures have increased has become known as the “pan ...

D. P. Rayner

2007-07-01T23:59:59.000Z

294

Evaporation from Nonvegetated Surfaces: Surface Aridity Methods and Passive Microwave Remote Sensing  

Science Conference Proceedings (OSTI)

The use of remotely sensed near-surface soil moisture for the estimation of evaporation is investigated. Two widely used parameterizations of evaporation, the so-called ? and ? methods, which use near-surface soil moisture to reduce some measure ...

Anthony T. Cahill; Marc B. Parlange; Thomas J. Jackson; Peggy O’Neill; T. J. Schmugge

1999-09-01T23:59:59.000Z

295

A model-based predictive supervisory controller for multi-evaporator HVAC systems  

Science Conference Proceedings (OSTI)

Multi-evaporator vapor compression cooling systems are representative of the complex, distributed nature of modern HVAC systems. Earlier research efforts focused on the development of a decentralized control architecture for individual evaporators that ...

Matthew S. Elliott; Bryan P. Rasmussen

2009-06-01T23:59:59.000Z

296

Exploring the Limits of Boiling and Evaporative Heat Transfer Using Micro/Nano Structures  

E-Print Network (OSTI)

a porous wick between the condenser and the evaporation. Theat the evaporator and condenser sections.. 26 Fig. 3.3a heat pipe Length of the condenser section in a heat pipe

Lu, Ming-Chang

2010-01-01T23:59:59.000Z

297

A Model of Intense Downdrafts Driven by the Melting and Evaporation of Precipitation  

Science Conference Proceedings (OSTI)

A ono-dimensioral time-dependent model of a downdraft driven by the melting and evaporation of precipitation and precipitation loading is formulated. Equations for particle melting, particle evaporation, particle concentration, precipitation ...

R. C. Srivastava

1987-07-01T23:59:59.000Z

298

Evaporation–Precipitation Variability over the Mediterranean and the Black Seas from Satellite and Reanalysis Estimates  

Science Conference Proceedings (OSTI)

Satellite retrievals of surface evaporation and precipitation from the Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data (HOAPS-3) dataset are used to document the distribution of evaporation, precipitation, and freshwater flux ...

A. Romanou; G. Tselioudis; C. S. Zerefos; C-A. Clayson; J. A. Curry; A. Andersson

2010-10-01T23:59:59.000Z

299

Temperature Dependence of Evaporation Coefficient for Water Measured in Droplets in Nitrogen under Atmospheric Pressure  

Science Conference Proceedings (OSTI)

The evaporation and the thermal accommodation coefficients for water in nitrogen were investigated by means of the analysis of evaporation of pure water droplet as a function of temperature. The droplet was levitated in an electrodynamic trap ...

D. Jakubczyk; M. Zientara; K. Kolwas; M. Kolwas

2007-03-01T23:59:59.000Z

300

Solar-MEC development program. Project 9103 third quarter progress report, March 1--May 31, 1978. [Desiccant wheel and regenerative heat exchange wheel performance  

DOE Green Energy (OSTI)

During the third quarter of the Solar-MEC program, work continued on developing the computer model simulating the desiccant wheel behavior (Task 1) and assessing the performance of the regenerative heat exchange wheel (Task 3). This report specifically presents the results obtained using the computer model as an analytical tool to evaluate design and operating conditions to optimize the wheel's performance. It also contains evaluations of two different available heat transfer matrixes: the currently used aluminum honeycomb and a new product, a potentially less-expensive, corrugated aluminum material. The mathematical modeling and diagnostic evaluations and ways of improving the component and machine performance were identified and are described for both tasks.

Wurm, J.; Weil, S.A.; Zawacki, T.S.; Kinast, J.A.; Macriss, R.A.

1978-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

Energy and economic assessment of desiccant cooling systems coupled with single glazed air and hybrid PV/thermal solar collectors for applications in hot and humid climate  

SciTech Connect

This paper presents a detailed analysis of the energy and economic performance of desiccant cooling systems (DEC) equipped with both single glazed standard air and hybrid photovoltaic/thermal (PV/t) collectors for applications in hot and humid climates. The use of 'solar cogeneration' by means of PV/t hybrid collectors enables the simultaneous production of electricity and heat, which can be directly used by desiccant air handling units, thereby making it possible to achieve very energy savings. The present work shows the results of detailed simulations conducted for a set of desiccant cooling systems operating without any heat storage. System performance was investigated through hourly simulations for different systems and load combinations. Three configurations of DEC systems were considered: standard DEC, DEC with an integrated heat pump and DEC with an enthalpy wheel. Two kinds of building occupations were considered: office and lecture room. Moreover, three configurations of solar-assisted air handling units (AHU) equipped with desiccant wheels were considered and compared with standard AHUs, focusing on achievable primary energy savings. The relationship between the solar collector's area and the specific primary energy consumption for different system configurations and building occupation patterns is described. For both occupation patterns, sensitivity analysis on system performance was performed for different solar collector areas. Also, this work presents an economic assessment of the systems. The cost of conserved energy and the payback time were calculated, with and without public incentives for solar cooling systems. It is worth noting that the use of photovoltaics, and thus the exploitation of related available incentives in many European countries, could positively influence the spread of solar air cooling technologies (SAC). An outcome of this work is that SAC systems equipped with PV/t collectors are shown to have better performance in terms of primary energy saving than conventional systems fed by vapour compression chillers and coupled with PV cells. All SAC systems present good figures for primary energy consumption. The best performances are seen in systems with integrated heat pumps and small solar collector areas. The economics of these SAC systems at current equipment costs and energy prices are acceptable. They become more interesting in the case of public incentives of up to 30% of the investment cost (Simple Payback Time from 5 to 10 years) and doubled energy prices. (author)

Beccali, Marco; Finocchiaro, Pietro; Nocke, Bettina [Universita degli Studi di Palermo, Palermo (Italy)

2009-10-15T23:59:59.000Z

302

Bench-Scale Evaporation of a Large Hanford Envelope C Sample (Tank 241-AN-102)  

Science Conference Proceedings (OSTI)

This report contains the results of the Bench Scale evaporation of a large sample of pretreated Envelope C (AN102).

Crowder, M.L.

2001-07-13T23:59:59.000Z

303

Converting Simulated Sodium-bearing Waste into a Single Solid Waste Form by Evaporation: Laboratory- and Pilot-Scale Test Results on Recycling Evaporator Overheads  

SciTech Connect

Conversion of Idaho National Engineering and Environmental Laboratory radioactive sodium-bearing waste into a single solid waste form by evaporation was demonstrated in both flask-scale and pilot-scale agitated thin film evaporator tests. A sodium-bearing waste simulant was adjusted to represent an evaporator feed in which the acid from the distillate is concentrated, neutralized, and recycled back through the evaporator. The advantage to this flowsheet is that a single remote-handled transuranic waste form is produced in the evaporator bottoms without the generation of any low-level mixed secondary waste. However, use of a recycle flowsheet in sodium-bearing waste evaporation results in a 50% increase in remote-handled transuranic volume in comparison to a non-recycle flowsheet.

Griffith, D.; D. L. Griffith; R. J. Kirkham; L. G. Olson; S. J. Losinski

2004-01-01T23:59:59.000Z

304

Experimental Research of the Falling-Film Evaporation Characteristic outside Horizontal Heat Pipe in the Vacuum  

Science Conference Proceedings (OSTI)

Face the energy crisis in the world, it is important to improve the utilization efficiency of the energy conversion. The evaporation characteristic of the falling film outside heat pipe in the vacuum as a good evaporation method was studied in the paper. ... Keywords: Falling film, Evaporation, Vacuum

Penghui Gao; Lixi Zhang; Hefei Zhang

2009-10-01T23:59:59.000Z

305

Optimal design of a micro evaporator with lateral gaps Taijong Sung a  

E-Print Network (OSTI)

­compression refrigeration sys- tem. The experimental design is adopted to determine the optimal parameters of the evaporatorOptimal design of a micro evaporator with lateral gaps Taijong Sung a , Daesik Oh b , Sangrok Jin online 1 March 2009 Keywords: Micro evaporator Optimal design Design of experiment Lateral gaps Two

Kim, Jongwon

306

An air cooled tube-fin evaporator model for an expansion valve control law  

Science Conference Proceedings (OSTI)

For control purposes, a mathematical model of a tube-fin evaporator of a vapour compression plant running with R22 is analyzed. The refrigerant behavior in an evaporating region is described by a homogeneous model. The balance equations, together with ... Keywords: Control devices, Evaporator models, Heat transfer, Nonlinear differential systems, Numerical methods, Phase transition

C. Aprea; C. Renno

1999-10-01T23:59:59.000Z

307

List of Evaporative Coolers Incentives | Open Energy Information  

Open Energy Info (EERE)

Coolers Incentives Coolers Incentives Jump to: navigation, search The following contains the list of 35 Evaporative Coolers Incentives. CSV (rows 1 - 35) Incentive Incentive Type Place Applicable Sector Eligible Technologies Active APS - Energy Efficiency Solutions for Business (Arizona) Utility Rebate Program Arizona Commercial Industrial Institutional Local Government Retail Supplier Schools State Government Building Insulation Central Air conditioners Chillers Comprehensive Measures/Whole Building Custom/Others pending approval Energy Mgmt. Systems/Building Controls Lighting Lighting Controls/Sensors Motor VFDs Motors Programmable Thermostats Refrigerators LED Exit Signs Evaporative Coolers Vending Machine Controls Food Service Equipment Yes Austin Utilities (Gas and Electric) - Commercial and Industrial Energy Efficiency Rebate Program (Minnesota) Utility Rebate Program Minnesota Commercial

308

Potential of Evaporative Cooling Systems for Buildings in India  

E-Print Network (OSTI)

Evaporative cooling potential for building in various climatic zones in India is investigated. Maintainable indoor conditions are obtained from the load - capacity analysis for the prevailing ambient conditions. For the assumed activity level, clothing and air velocity, the predicted mean vote (PMV), predicted percentage dissatisfied (PPD), and cumulative dissatisfaction levels for each month are estimated. Time - air condition contours of ambient, supply air and indoor air are plotted on a psychrometric chart for different cities in India like Ahmadabad, Jodhpur, Nagpur and New Delhi representing different climatic conditions of India. While satisfactorily comfort can be achieved at cool and dry weather conditions by evaporative cooling system throughout the year, some discomfort prevailed for few months around July at hot and dry/humid weather conditions. The results are also quantified in terms of PMV, PPD and their cumulative factors; PMV-hour and PPD-hour.

Maiya, M. P.; Vijay, S.

2010-01-01T23:59:59.000Z

309

Solid material evaporation into an ECR source by laser ablation  

Science Conference Proceedings (OSTI)

In an effort to explore new methods of producing ion beams from solid materials, we are attempting to develop a laser-ablation technique for evaporating materials directly into an ECR ion source plasma. A pulsed NdYaG laser with approximately 25 watts average power and peak power density on the order of 10{sup 7} W/cm{sup 2} has been used off-line to measure ablation rates of various materials as a function of peak laser power. The benefits anticipated from the successful demonstration of this technique include the ability to use very small quantities of materials efficiently, improved material efficiency of incorporation into the ECR plasma, and decoupling of the material evaporation process from the ECR source tuning operation. Here we report on the results of these tests and describe the design for incorporating such a system directly with the ATLAS PII-ECR ion source.

Harkewicz, R.; Stacy, J.; Greene, J.; Pardo, R.C.

1993-09-01T23:59:59.000Z

310

Phases of information release during black hole evaporation  

E-Print Network (OSTI)

In a recent article, we have shown how quantum fluctuations of the background geometry modify Hawking's density matrix for black hole (BH) radiation. Hawking's diagonal matrix picks up small off-diagonal elements whose influence becomes larger with the number of emitted particles. We have calculated the "time-of-first-bit", when the first bit of information comes out of the BH, and the "transparency time", when the rate of information release becomes order unity. We have found that the transparency time is equal to the "Page time", when the BH has lost half of its initial entropy to the radiation, in agreement with Page's results. Here, we improve our previous calculation by keeping track of the time of emission of the Hawking particles and their back-reaction on the BH. Our analysis reveals a new time scale, the radiation "coherence time", which is equal to the geometric mean of the evaporation time and the light crossing time. We find, as for our previous treatment, that the time-of-first-bit is equal to the coherence time, which is much shorter than the Page time. But the transparency time is now much later than the Page time, just one coherence time before the end of evaporation. Close to the end, when the BH is parametrically of Planckian dimensions but still large, the coherence time becomes parametrically equal to the evaporation time, thus allowing the radiation to purify. We also determine the time dependence of the entanglement entropy of the early and late-emitted radiation. This entropy is small during most of the lifetime of the BH, but our qualitative analysis suggests that it becomes parametrically maximal near the end of evaporation.

Ram Brustein; A. J. M. Medved

2013-10-22T23:59:59.000Z

311

Evaporation Time of Ho?ava Gravity Black Holes  

Science Conference Proceedings (OSTI)

Recently it has been a lot of interest in the theory proposed by Ho?ava because is a remormalizable theory of gravity and may be a candidate for the UV completion of Einstein gravity. In the present work we study thermodynamical properties of black hole type solutions in this setup. In particular we are able to obtain times of evaporation for black hole solution in this formalism.

S. Pérez?Payán; M. Sabido

2011-01-01T23:59:59.000Z

312

Mesoporous-silica films, fibers, and powders by evaporation  

SciTech Connect

This invention pertains to surfactant-templated nanometer-scale porosity of a silica precursor solution and forming a mesoporous material by first forming the silica precursor solution into a preform having a high surface area to volume ratio, then rapid drying or evaporating a solvent from the silica precursor solution. The mesoporous material may be in any geometric form, but is preferably in the form of a film, fiber, powder or combinations thereof. The rapid drying or evaporation of solvent from the solution is accomplished by layer thinning, for example spin casting, liquid drawing, and liquid spraying respectively. Production of a film is by layer thinning, wherein a layer of the silica precursor solution is formed on a surface followed by removal of an amount of the silica precursor solution and leaving a geometrically thinner layer of the silica precursor solution from which the solvent quickly escapes via evaporation. Layer thinning may be by any method including but not limited to squeegeeing and/or spin casting. In powder formation by spray drying, the same conditions of fast drying exists as in spin-casting (as well as in fiber spinning) because of the high surface-area to volume ratio of the product. When a powder is produced by liquid spraying, the particles or micro-bubbles within the powder are hollow spheres with walls composed of mesoporous silica. Mesoporous fiber formation starts with a similar silica precursor solution but with an added pre-polymer making a pituitous mixture that is drawn into a thin strand from which solvent is evaporated leaving the mesoporous fiber(s).

Bruinsma, Paul J. (Kennewick, WA); Baskaran, Suresh (Kennewick, WA); Bontha, Jagannadha R. (Richland, WA); Liu, Jun (West Richland, WA)

1999-01-01T23:59:59.000Z

313

Enhanced Chemical Cleaning  

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

Chemical Cleaning Chemical Cleaning Renee H. Spires Enhanced Chemical Cleaning Project Manager July 29, 2009 Tank Waste Corporate Board 2 Objective Provide an overview of the ECC process and plan 3 Chemical Cleaning * Oxalic Acid can get tanks clean - Tank 16 set a standard in 1982 - Tanks 5-6 Bulk OA cleaning results under evaluation * However, the downstream flowsheet and financial impacts of handling the spent acid were unacceptable Before After Tank 16 Tank 16 4 Oxalic Acid Flowsheet Impacts Evap Sludge Washing Evap Feed/Drop Tank 8 Wt% Oxalic Acid Neutralization Tank Solids Liquid High oxalate concentration Negligible oxalate concentration * Oxalates from chemical cleaning impact salt processing * A process change was needed Evaporator Saltstone Vaults DWPF Filled Canisters 5 Vision * Eliminate the impacts to the Tank Farm

314

Enhanced two phase flow in heat transfer systems  

DOE Patents (OSTI)

A family of structures and designs for use in devices such as heat exchangers so as to allow for enhanced performance in heat exchangers smaller and lighter weight than other existing devices. These structures provide flow paths for liquid and vapor and are generally open. In some embodiments of the invention, these structures can also provide secondary heat transfer as well. In an evaporate heat exchanger, the inclusion of these structures and devices enhance the heat transfer coefficient of the evaporation phase change process with comparable or lower pressure drop.

Tegrotenhuis, Ward E; Humble, Paul H; Lavender, Curt A; Caldwell, Dustin D

2013-12-03T23:59:59.000Z

315

Heavy quark production in the black hole evaporation at LHC  

SciTech Connect

The understanding of Quantum Chromodynamics (QCD) and Quantum Gravity are currently two of the main open questions in Physics. In order to understand these problems some authors proposed the existence of extra dimensions in the Nature. These extra dimensions would be compacted and not visible on the macroscopic world, but the effects would be manifest in ultrarelativistic colision process. In particular, black holes (BH) could be produced in proton-proton colisions in the Large Hadron Collider (LHC) and in future colliders. The BH is an object characterized by its mass and temperature wich also characterizes the evaporation process. All kind of particle should be produced in this process. Our goal in this contribution is to study the BH production in proton - proton collisions at LHC and its evaporation rate in heavy quarks. We present our estimate considering two scenarios (with and without trapped energy corrections) and compare our predictions with those obtained using perturbative QCD. Our results demonstrate that in both scenarios the charm and bottom production in the BH evaporation are smaller than the QCD prediction at LHC. In contrast, the top production is similar or larger than the QCD prediction, if the trapped energy corrections are disregarded.

Thiel, M.; Goncalves, V. P.; Sauter, W. K. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas (Brazil)

2013-03-25T23:59:59.000Z

316

Evaporation of a Large Decontaminated Hanford Tank Sample  

SciTech Connect

A radioactive sample (approximately 15 L) from Hanford tank 241-AN-102 was concentrated via evaporation at reduced pressure and temperature, to support flowsheet development and regulatory approval for the Hanford River Protection Project Waste Treatment Plant (RPP-WTP). The received sample (Envelope C) had been pretreated at the Savannah River Technology Center (SRTC) for removal of strontium and transuranic ions by precipitation and removal of cesium and technetium via ion exchange. The resulting pretreated Low Activity Waste (LAW) stream was the feed material for this evaporation test. The goals of this evaporation were to: (1) provide operating data -- including foaming and scaling tendencies -- for scale-up purposes, (2) obtain liquid and off-gas samples during steady-state operation for regulatory analysis, (3) conduct a ''final boildown'' after the steady-state operation to determine the solubility endpoint of the solution and the major precipitants, and (4) provide concentrated feed for a melter vitrification study to produce several kilograms of immobilized LAW glass product.

Crawford, C.L.

2001-03-22T23:59:59.000Z

317

Moduli Vacuum Bubbles Produced by Evaporating Black Holes  

E-Print Network (OSTI)

We consider a model with a toroidally compactified extra dimension giving rise to a temperature-dependent 4d effective potential with one-loop contributions due to the Casimir effect, along with a 5d cosmological constant. The forms of the effective potential at low and high temperatures indicates a possibility for the formation of a domain wall bubble, formed by the modulus scalar field, surrounding an evaporating black hole. This is viewed as an example of a recently proposed black hole vacuum bubble arising from matter-sourced moduli fields in the vicinity of an evaporating black hole [D. Green, E. Silverstein, and D. Starr, Phys. Rev. D74, 024004 (2006), arXiv:hep-th/0605047]. The black hole bubble can be highly opaque to lower energy particles and photons, and thereby entrap them within. For high temperature black holes, there may also be a symmetry-breaking black hole bubble of false vacuum of the type previously conjectured by Moss [I.G. Moss, Phys. Rev. D32,1333 (1985)], tending to reflect low energy particles from its wall. A double bubble composed of these two different types of bubble may form around the black hole, altering the hole's emission spectrum that reaches outside observers. Smaller mass black holes that have already evaporated away could have left vacuum bubbles behind that contribute to the dark matter.

J. R. Morris

2007-08-14T23:59:59.000Z

318

Thermodynamics of an Evaporating Schwarzschild Black Hole in Noncommutative Space  

E-Print Network (OSTI)

We investigate the effects of space noncommutativity and the generalized uncertainty principle on the thermodynamics of a radiating Schwarzschild black hole. We show that evaporation process is in such a way that black hole reaches to a maximum temperature before its final stage of evolution and then cools down to a nonsingular remnant with zero temperature and entropy. We compare our results with more reliable results of string theory. This comparison Shows that GUP and space noncommutativity are similar concepts at least from view point of black hole thermodynamics.

Kourosh Nozari; Behnaz Fazlpour

2006-05-11T23:59:59.000Z

319

Black Hole evaporation in semi-classical approach  

E-Print Network (OSTI)

As well as known, the black hole evaporation problem is famous problem. Because the S.W.Hawking found the black holes emit light at the future null infinity as a thermal radiation \\cite{H}, we think that the black holes may be vanish. However, to prove this problem, we should solve field equation, i.e. forth order partial differential equations \\cite{Ford}\\cite{BD}. However, we can find a method to solve this equation, and we could prove that the black holes finally vanish. To solve this problem we use dynamical horizons equation in the Vaidya spacetime.

Shintaro Sawayama

2011-02-15T23:59:59.000Z

320

A field evaporation deuterium ion source for neutron generators  

E-Print Network (OSTI)

Proof-of-principle experiments have demonstrated an electrostatic field evaporation based deuterium ion source for use in compact, high-output deuterium-tritium neutron generators. The ion source produces principally atomic deuterium and titanium ions. More than 100 monolayers of deuterated titanium thin film can be removed and ionized from a single tip in less than 20 ns. The measurements indicate that with the use of microfabricated tip arrays the deuterium ion source could provide sufficient ion current to produce 10^9 to 10^10 n/cm^2 of tip array area.

Reichenbach, Birk; Schwoebel, P R; 10.1063/1.2913331

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

On the interface instability during rapid evaporation in microgravity  

Science Conference Proceedings (OSTI)

The rapid evaporation of a superheated liquid (vapor explosion) under microgravity conditions is studied by direct numerical simulation. The time-dependent Navier-Stokes and energy equations coupled to the interface dynamics are solved using a two-dimensional finite-difference/front-tracking method. Large interface deformations, topology change, latent heat, surface tension and unequal material properties between the liquid and vapor phases are included in the simulations. A comparison of numerical results to the exact solution of a one-dimensional test problem shows excellent agreement. For the two-dimensional rapid evaporation problem, the vapor volume growth rate and unstable interface dynamics are studied for increasing levels of initial liquid superheat. As the superheat is increased the liquid-vapor interface experiences increasingly unstable energetic growth. These results indicate that heat transfer plays a very important role in the instability mechanism leading to vapor explosions. It is suggested that the Mullins-Sekerka instability could play a role in the instability initiation mechanism.

Juric, D. [Los Alamos National Lab., NM (United States). Theoretical Div.

1997-05-01T23:59:59.000Z

322

Enhanced Mechanical Properties of Surface Modified Inconel 718 ...  

Science Conference Proceedings (OSTI)

Presentation Title, Enhanced Mechanical Properties of Surface Modified Inconel 718 ... and Recovery Process of Rare Metals from Oil Desulfurization Spent Catalyst ... Pulsed Laser Evaporation: An Enabling Technology for Organic Thin Films ... Redox Investigation of NiFe2O4 Supported on Al2O3 and Yttria- Stabilized ...

323

SERI Desiccant Cooling Test Facility. Status report. Preliminary data on the performance of a rotary parallel-passage silica-gel dehumidifier  

DOE Green Energy (OSTI)

This report describes the SERI Desiccant Cooling Test Facility. The facility can test bench-scale rotary dehumidifiers over a wide range of controlled conditions. We constructed and installed in the test loop a prototype parallel-passage rotary dehumidifier that has spirally wound polyester tape coated with silica gel. The initial tests gave satisfactory results indicating that approximately 90% of the silica gel was active and the overall Lewis number of the wheel was near unity. The facility has several minor difficulties including an inability to control humidity satisfactorily and nonuniform and highly turbulent inlet velocities. To completely validate the facility requires a range of dehumidifier designs. Several choices are available including constructing a second parallel-passage dehumidifier with the passage spacing more uniform.

Schultz, K.J.

1986-04-01T23:59:59.000Z

324

EVAPORATIVE METAL BONDING OF CM247LC TO KANTHAL APMT John P...  

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

joining alloys tested, one of which evaporates from the structures. Project Overview * Welding of advanced alloys is not possible because critical structures are destroyed. *...

325

Characterizing the Variability of the Indian Monsoon: Changes in the Evaporative Sources for Summertime Rainfall Events.  

E-Print Network (OSTI)

?? This study focuses on the interannual and intraseasonal variability of evaporative sources for rainfall events during the Indian monsoon. The monsoon is an important… (more)

Pantina, Peter

2010-01-01T23:59:59.000Z

326

The use of carbonation and fractional evaporative crystallization in the pretreatment of Hanford nuclear wastes.  

E-Print Network (OSTI)

??The purpose of this work was to explore the use of fractional evaporative crystallization as a technology that can be used to separate medium-curie waste… (more)

Dumont, George Pierre, Jr.

2007-01-01T23:59:59.000Z

327

Geothermal: Sponsored by OSTI -- Study of falling-jet flash evaporator...  

Office of Scientific and Technical Information (OSTI)

Study of falling-jet flash evaporators Geothermal Technologies Legacy Collection HelpFAQ | Site Map | Contact Us | Admin Log On HomeBasic Search About Publications Advanced...

328

Vibration Induced Droplet Generation from a Liquid Layer for Evaporative Cooling in a Heat Transfer Cell .  

E-Print Network (OSTI)

??During this investigation, vibration induced droplet generation from a liquid layer was examined as a means for achieving high heat flux evaporative cooling. Experiments were… (more)

Pyrtle, Frank, III

2005-01-01T23:59:59.000Z

329

Fixture for forming evaporative pattern (EPC) process patterns  

DOE Patents (OSTI)

A method of casting metal using evaporative pattern casting process patterns in combination with a fixture for creating and maintaining a desired configuration in flexible patterns. A pattern is constructed and gently bent to the curvature of a suitable fixture. String or thin wire, which burns off during casting, is used to tie the pattern to the fixture. The fixture with pattern is dipped in a commercially available refractory wash to prevent metal adherence and sticking to the fixture. When the refractory wash is dry, the fixture and pattern are placed in a flask, and sand is added and compacted by vibration. The pattern remains in position, restrained by the fixture. Metal that is poured directly into the pattern replaces the pattern exactly but does not contact or weld to the fixture due to the protective refractory layer. When solid, the casting is easily separated from the fixture. The fixture can be cleaned for reuse in conventional casting cleaning equipment.

Turner, Paul C. (Albany, OR); Jordan, Ronald R. (Albany, OR); Hansen, Jeffrey S. (Corvallis, OR)

1993-01-01T23:59:59.000Z

330

A graphics processor-based intranuclear cascade and evaporation simulation  

E-Print Network (OSTI)

Monte Carlo simulations of the transport of protons in human tissue have been deployed on graphics processing units (GPUs) with impressive results. To provide a more complete treatment of non-elastic nuclear interactions in these simulations, we developed a fast intranuclear cascade-evaporation simulation for the GPU. This can be used to model non-elastic proton collisions on any therapeutically relevant nuclei at incident energies between 20 and 250 MeV. Predictions are in good agreement with Geant4.9.6p2. It takes approximately 2 s to calculate $1\\times 10^6$ 200 MeV proton-$^{16}$O interactions on a NVIDIA GTX680 GPU. A speed-up factor of $\\sim$20 relative to one Intel i7-3820 core processor thread was achieved.

H. Wan Chan Tseung; C. Beltran

2013-09-30T23:59:59.000Z

331

Transparent electrical conducting films by activated reactive evaporation  

DOE Patents (OSTI)

Process and apparatus for producing transparent electrical conducting thin films by activated reactive evaporation is disclosed. Thin films of low melting point metals and alloys, such as indium oxide and indium oxide doped with tin, are produced by physical vapor deposition. The metal or alloy is vaporized by electrical resistance heating in a vacuum chamber, oxygen and an inert gas such as argon are introduced into the chamber, and vapor and gas are ionized by a beam of low energy electrons in a reaction zone between the resistance heater and the substrate. There is a reaction between the ionized oxygen and the metal vapor resulting in the metal oxide which deposits on the substrate as a thin film which is ready for use without requiring post deposition heat treatment. 1 fig.

Bunshah, R.; Nath, P.

1982-06-22T23:59:59.000Z

332

Transparent electrical conducting films by activated reactive evaporation  

DOE Patents (OSTI)

Process and apparatus for producing transparent electrical conducting thin films by activated reactive evaporation. Thin films of low melting point metals and alloys, such as indium oxide and indium oxide doped with tin, are produced by physical vapor deposition. The metal or alloy is vaporized by electrical resistance heating in a vacuum chamber, oxygen and an inert gas such as argon are introduced into the chamber, and vapor and gas are ionized by a beam of low energy electrons in a reaction zone between the resistance heater and the substrate. There is a reaction between the ionized oxygen and the metal vapor resulting in the metal oxide which deposits on the substrate as a thin film which is ready for use without requiring post deposition heat treatment.

Bunshah, Rointan (Los Angeles, CA); Nath, Prem (Troy, MI)

1982-01-01T23:59:59.000Z

333

Growth study of ion assisted evaporated molybdenum thin films  

Science Conference Proceedings (OSTI)

We reported optimization of ion-to-atom ratios and ion energy for growth of molybdenum thin film on oxidized silicon substrate using ion assisted electron beam evaporation system. The ion-to-atom ratio is varied by independently adjusting the ion current density and deposition rate. The structural characterization of the films is carried out by hard X-ray reflectivity. We observed improvement in film density from 85.5% to 98.2% and film roughness from {approx}2 nm to 0.84nm on {approx}26 nm thick Mo film by optimizing ion parameters. The observed results are discussed considering the effect of kinetic of adatoms during growth of film.

Yadav, P. K.; Nayak, M.; Lodha, G. S.; Rai, S. [X-ray Optics Section, Indus Synchrotrons Utilization Division, Raja Ramanna Centre For Advanced Technology, Indore-452013 (India)

2012-06-25T23:59:59.000Z

334

A note on the evaporation of a stagnant liquid  

SciTech Connect

The main objective of this report was the understanding of the effect of higher pressures on the velocity of the gas-liquid interface. Experimental evidence (Le Romancer et al.) suggests that high-pressure gas injection results under certain conditions in a decrease of the rate of the interface motion, a result that may be due to gas dissolution and diffusion in the liquid phase. To explore this possibility, it was considered in this paper a simple 1-D model of this process as illustrated schematically in a figure. A liquid A, originally occupying a semi-infinite medium, is subject to evaporation and diffusion in a flowing gas B, the composition of which at the top of the medium (at z = 0) remains constant. Due to the possible high pressure in the gas, component B may solubilize and counter-diffuse in the liquid phase.

Tsimpanogiannis, Ioannis N.; Yortsos, Yanis C.; Stubos, A.K.

2000-03-06T23:59:59.000Z

335

Improvement to Air2Air Technology to Reduce Fresh-Water Evaporative Cooling Loss at Coal-Based Thermoelectric Power Plants  

Science Conference Proceedings (OSTI)

This program was undertaken to enhance the manufacturability, constructability, and cost of the Air2Air{TM} Water Conservation and Plume Abatement Cooling Tower, giving a validated cost basis and capability. Air2Air{TM} water conservation technology recovers a portion of the traditional cooling tower evaporate. The Condensing Module provides an air-to-air heat exchanger above the wet fill media, extracting the heat from the hot saturated moist air leaving in the cooling tower and condensing water. The rate of evaporate water recovery is typically 10% - 25% annually, depending on the cooling tower location (climate). This program improved the efficiency and cost of the Air2Air{TM} Water Conservation Cooling Tower capability, and led to the first commercial sale of the product, as described.

Ken Mortensen

2011-12-31T23:59:59.000Z

336

Stochastic modeling of evaporating sprays within a consistent hybrid joint PDF framework  

SciTech Connect

In the present study, a framework for modeling two-phase evaporating flow is presented, which employs an Eulerian-Lagrangian-Lagrangian approach. For the continuous phase, a joint velocity-composition probability density function (PDF) method is used. Opposed to other approaches, such PDF methods require no modeling for turbulent convection and chemical source terms. For the dispersed phase, the PDF of velocity, diameter, temperature, seen gas velocity and seen gas composition is calculated. This provides a unified formulation, which allows to consistently address the different modeling issues associated with such a system. Because of the high dimensionality, particle methods are employed to solve the PDF transport equations. To further enhance computational efficiency, a local particle time-stepping algorithm is implemented and a particle time-averaging technique is employed to reduce statistical and bias errors. In comparison to previous studies, a significantly smaller number of droplet particles per grid cell can be employed for the computations, which rely on two-way coupling between the droplet and gas phases. The framework was validated using established experimental data and a good overall agreement can be observed.

Anand, Gaurav [Institute of Fluid Dynamics, Sonneggstrasse 3, ETH Zurich, Zuerich CH-8092 (Switzerland)], E-mail: anand@ifd.mavt.ethz.ch; Jenny, Patrick [Institute of Fluid Dynamics, Sonneggstrasse 3, ETH Zurich, Zuerich CH-8092 (Switzerland)], E-mail: jenny@ifd.mavt.ethz.ch

2009-04-01T23:59:59.000Z

337

CORRELATING EVAPORATION HEAT TRANSFER COEFFICIENT OF REFRIGERANT R-134a IN A PLATE HEAT EXCHANGER  

E-Print Network (OSTI)

1 CORRELATING EVAPORATION HEAT TRANSFER COEFFICIENT OF REFRIGERANT R-134a IN A PLATE HEAT EXCHANGER for evaporation heat transfer coefficient of refrigerant R-134a flowing in a plate heat exchanger. Correlation heat exchanger are found to result in large discrepancies with their own experimental data

Kandlikar, Satish

338

Stochastic modeling of evaporating sprays within a consistent hybrid joint PDF framework  

Science Conference Proceedings (OSTI)

In the present study, a framework for modeling two-phase evaporating flow is presented, which employs an Eulerian-Lagrangian-Lagrangian approach. For the continuous phase, a joint velocity-composition probability density function (PDF) method is used. ... Keywords: Evaporation, Hybrid algorithm, Multi-phase flow, PDF method, Particle local time-stepping, Spray, Stochastic method, Time-averaging, Turbulent flow

Gaurav Anand; Patrick Jenny

2009-04-01T23:59:59.000Z

339

EVAPORATION OF CAI LIQUIDS INTO SOLAR GAS. A. V. , L. Grossman1,2  

E-Print Network (OSTI)

EVAPORATION OF CAI LIQUIDS INTO SOLAR GAS. A. V. Fedkin1 , L. Grossman1,2 and S. B. Simon1 , 1-like liquids evaporating into more general gas compositions. In this work, we assume that a CAI precursor liquid is immersed in a gas whose composition is solar except for the amounts of CMAS components which

Grossman, Lawrence

340

Temperature Effect on Pump Oil and Alkanes Evaporation Nathaniel A. Waldstein and Alex A. Volinsky  

E-Print Network (OSTI)

Temperature Effect on Pump Oil and Alkanes Evaporation Nathaniel A. Waldstein and Alex A. Volinsky rates of pump oil and several alkanes, which have a wide range of applications. Both static and dynamic systems. Pump oil was also evaporated from two types of microchannels. Developed testing procedures help

Volinsky, Alex A.

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

An Analytical Model of Evaporation Efficiency for Unsaturated Soil Surfaces with an Arbitrary Thickness  

Science Conference Proceedings (OSTI)

Analytical expressions of evaporative efficiency over bare soil (defined as the ratio of actual to potential soil evaporation) have been limited to soil layers with a fixed depth and/or to specific atmospheric conditions. To fill the gap, a new ...

Olivier Merlin; Ahmad Al Bitar; Vincent Rivalland; Pierre Béziat; Eric Ceschia; Gérard Dedieu

2011-02-01T23:59:59.000Z

342

Organic emission calculations for the 242-A evaporator vessel vent system  

Science Conference Proceedings (OSTI)

This document contains historical calculations originally published in the 242-A Evaporator Dangerous Waste Permit Application, DOE/RL-90-42, Rev 0. They are being released as a supporting document, along with brief explanatory information, to be used as a reference in Rev 1 of the permit application and in other supporting documents, such as the 242-A Evaporator Data Quality Objectives.

Bowman, M.R.

1996-06-20T23:59:59.000Z

343

Comparative Detoxification of Vacuum Evaporation/Steam Stripping Combined with Overliming on Corn Stover Prehydrolyzate  

Science Conference Proceedings (OSTI)

Tow kinds of physical methods, vacuum evaporation and steam stripping, combined with overliming (calcium hydroxide) were applied to remove inhibitors which were produced simultaneously during the pretreatment of lignocellulosic biomass. Corn stover was ... Keywords: vacuum evaporation, steam stripping, overliming, corn stover prehydrolyzate, detoxification

Jun-jun Zhu; Qiang Yong; Yong Xu; Shi-yuan Yu

2009-10-01T23:59:59.000Z

344

A Model and Experimental Study of Evaporation from Bare-Soil Surfaces  

Science Conference Proceedings (OSTI)

A model is constructed for estimating evaporation from bare-soil surfaces. In the model, the evaporation is parameterized with the soil-water content for the upper 2 cm of the soil (Kondo et al.), and the heat and water transport within the soil ...

Junsei Kondo; Nobuko Saigusa; Takeshi Sato

1992-03-01T23:59:59.000Z

345

The Study of Solar Desalination System with Falling Film Evaporation and Its Operation  

Science Conference Proceedings (OSTI)

The seawater desalination system with falling film evaporation was set up, which was driven by solar-wind energy. In addition, the basic principles of system operation were expounded?and the main factors affecting the system performance were discussed. ... Keywords: Seawater desalination, Solar energy, Falling film evaporation

Chen Zhi-li; He Qiang; Zheng Hong-fei; Long Xiang-yu; Wang Wen-biao; Zhuang Chun-long; Yi Qi-zhen

2009-10-01T23:59:59.000Z

346

Steam Oxidation and Chromia Evaporation in Ultra-Supercritical Steam Boilers and Turbines  

SciTech Connect

U.S. Department of Energy’s goals include power generation from coal at 60% efficiency, which requires steam conditions of up to 760 °C and 340 atm, so-called ultra-supercritical (USC) conditions. Evaporation of protective chromia scales is expected to be a primary corrosion mechanism. A methodology to calculate Cr evaporation rates from chromia scales was developed and combined with Cr diffusion calculations within the alloy (with a constant flux of Cr leaving the alloy from evaporation) to predict Cr concentration profiles and to predict the time until breakaway oxidation. At the highest temperatures and pressures, the time until breakaway oxidation was predicted to be quite short for the turbine blade, and of concern within the steam pipe and the higher temperature portions of the superheater tube. Alloy additions such as Ti may allow for a reduction in evaporation rate with time, mitigating the deleterious effects of chromia evaporation.

Gordon H. Holcomb

2009-01-01T23:59:59.000Z

347

Microsoft PowerPoint - 3-04_Tedeschi_Wiped Film Evaporator.pptx  

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

of a Thin Film Evaporator for Development of a Thin Film Evaporator for of a Thin Film Evaporator for Development of a Thin Film Evaporator for Deployment at Hanford Tank Farms Deployment at Hanford Tank Farms EM Waste Processing Technical Exchange November, 2010 Atlanta, GA Allan R. "Rick" Tedeschi Washington River Protection Solutions, LLC Contractor to the United States Department of Energy Print Close Agenda Page 2 Summary Development and Project Background Pilot-scale Development Laboratory-scale Development Full-scale Development and Deployment Print Close Summary Report on thin-film evaporative technology development effort, and describe path forward for technology deployment Page 3  Pilot-scale testing has successfully demonstrated concentration of supernatant simulants to 1.4 - 1.5 specific gravity (sp gr)  Pilot-scale testing has refined and confirmed

348

Compact Liquid Waste Evaporator for Cleanup on Hanfords Hot Cells [FULL PAPER  

SciTech Connect

Removal of radionuclide and hazardous contaminants from hot cells in Hanford's 324 Building will produce an aqueous waste stream requiring volume reduction and packaging. This paper describes a compact and remotely-operated evaporator system that was designed for use in the 324 Building's B-Cell (a shielded hot cell) to volume-reduce the waste waters that are generated from pressure washing of hot cell ceiling, wall, and floor surfaces. The evaporator incorporates an electric-heated reboiler to provide evaporation and drying to allow disposal of waste material. Design features of the evaporator system were strongly influenced by the need for remote handling and remote maintenance. Purified water vapor from the evaporation process will be released directly to the hot cell ventilation air.

HOBART, R.L.

2003-11-14T23:59:59.000Z

349

Steam oxidation and chromia evaporation in ultrasupercritical steam boilers and turbines  

Science Conference Proceedings (OSTI)

The U.S. Department of Energy's goals include power generation from coal at 60% efficiency, which requires steam conditions of up to 760 {sup o}C and 340 atm, so-called ultrasupercritical conditions. Evaporation of protective chromia scales is a primary corrosion mechanism. A methodology to calculate Cr evaporation rates from chromia scales was developed and combined with Cr diffusion calculations within the alloy (with a constant flux of Cr leaving the alloy from evaporation) to predict Cr concentration profiles and to predict the time until breakaway oxidation. At the highest temperatures and pressures, the time until breakaway oxidation was quite short for the turbine blade, and of concern within the steam pipe and the higher temperature portions of the superheater tube. Alloy additions such as Ti may allow for a reduction in evaporation rate with time, mitigating the deleterious effects of chromia evaporation.

Holcomb, G.R. [US DOE, Albany, OR (United States)

2009-07-01T23:59:59.000Z

350

Enhanced Micellar Catalysis LDRD.  

SciTech Connect

The primary goals of the Enhanced Micellar Catalysis project were to gain an understanding of the micellar environment of DF-200, or similar liquid CBW surfactant-based decontaminants, as well as characterize the aerosolized DF-200 droplet distribution and droplet chemistry under baseline ITW rotary atomization conditions. Micellar characterization of limited surfactant solutions was performed externally through the collection and measurement of Small Angle X-Ray Scattering (SAXS) images and Cryo-Transmission Electron Microscopy (cryo-TEM) images. Micellar characterization was performed externally at the University of Minnesota's Characterization Facility Center, and at the Argonne National Laboratory Advanced Photon Source facility. A micellar diffusion study was conducted internally at Sandia to measure diffusion constants of surfactants over a concentration range, to estimate the effective micelle diameter, to determine the impact of individual components to the micellar environment in solution, and the impact of combined components to surfactant phase behavior. Aerosolized DF-200 sprays were characterized for particle size and distribution and limited chemical composition. Evaporation rates of aerosolized DF-200 sprays were estimated under a set of baseline ITW nozzle test system parameters.

Betty, Rita G.; Tucker, Mark David; Taggart, Gretchen; Kinnan, Mark K.; Glen, Crystal Chanea; Rivera, Danielle; Sanchez, Andres; Alam, Todd Michael

2012-12-01T23:59:59.000Z

351

2F and 2H evaporator loop evaluation closure report  

SciTech Connect

As a result of the Concentrate Transfer System (CTS) tank ventilation system contamination event, a task team was formed to evaluate instrument loops associated with waste reduction equipment. During the event a conductivity probe designed to provide an alarm and initiate an interlock failed to respond to the presence of liquid. An investigation revealed that the probe had become disconnected from the loop. The daily functional check of the conductivity probe circuit only tested the circuit continuity from the ventilation unit to the control room and did not actually test the probe. To test the continuity, a test switch was used to simulate the conducting probe. Because the functional check did not test each part of the loop, the test could be satisfactorily completed even though the probe itself was inoperable. The function of the task team was to develop a list of loops and interlocks prioritized by importance and likelihood of similar failure. The team evaluated the associated loop calibration and functional test procedures to verify that they are adequate to ensure loop performance on a periodic frequency. This report documents the evaluation findings and associated actions required prior to startup of the 2F and 2H evaporators.

Bates, W.F.

1994-01-28T23:59:59.000Z

352

Heat exchanger efficiently operable alternatively as evaporator or condenser  

DOE Patents (OSTI)

A heat exchanger adapted for efficient operation alternatively as evaporator or condenser and characterized by flexible outer tube having a plurality of inner conduits and check valves sealingly disposed within the outer tube and connected with respective inlet and outlet master flow conduits and configured so as to define a parallel flow path for a first fluid such as a refrigerant when flowed in one direction and to define a serpentine and series flow path for the first fluid when flowed in the opposite direction. The flexible outer tube has a heat exchange fluid, such as water, flowed therethrough by way of suitable inlet and outlet connections. The inner conduits and check valves form a package that is twistable so as to define a spiral annular flow path within the flexible outer tube for the heat exchange fluid. The inner conduits have thin walls of highly efficient heat transfer material for transferring heat between the first and second fluids. Also disclosed are specific materials and configurations.

Ecker, Amir L. (Dallas, TX)

1981-01-01T23:59:59.000Z

353

Failure Analysis of 6.8 Evaporator Thermowell  

SciTech Connect

The Savannah River Technology Center Materials technology Section was requested to determine the cause of failure for a resistance temperature device and thermowell assembly that was used in the 6.8 Low Activity Waste evaporator. A methodical and well planned approach was used for the failure analysis task with special precautions because of the high radiation and contamination levels. Two sections of the failed assembly were selected for thorough analysis, the bottom of the inner tube with the end-cap and a piece of inner tube at the vapor/waste interface. The failure analysis consisted of macroscopic examination and metallographic analysis. Intergranular attack (IGA) was found to be the primary corrosion mechanism that led to eventual failure. IGA of the end cap occurred because of a presumed preferential microstructure and accelerated the corrosion rate over that of inner-tube side wall. Once the end cap was breached, the waste quickly attacked the RTD components, leading to the low resistance to ground readings that indicated the initial RTD malfunction. A metallographic analysis of an unexposed end cap is recommended to confirm the suspect microstructure.

MICKALONIS, JOHNI.

2004-06-01T23:59:59.000Z

354

An Analysis of the Effect of Local Heat Advection on Evaporation over Wet and Dry Surface Strips  

Science Conference Proceedings (OSTI)

The effect of local advection on evaporation and Bowen ratio over alternating crosswind infinite dry-warm and wet-cool surface strips (patches), by redistribution of surface heat, is analysed. The analysis shows that evaporation over the region ...

Ya Guo; Peter H. Schuepp

1994-05-01T23:59:59.000Z

355

ACID EVAPORATION OF ULTIMA GOLD TM AB LIQUID SCINTILLATION COCKTAIL RESIDUE  

SciTech Connect

Prior analyses of samples from the F/H Lab solutions showed the presence of diisopropylnapthalene (DIN), a major component of Ultima Gold{trademark} AB liquid scintillation cocktail (LSC). These solutions are processed through H-Canyon Tank 10.5 and ultimately through the 17.8E evaporator. Similar solutions originated in SRNL streams sent to the same H Canyon tanks. This study examined whether the presence of these organics poses a process-significant hazard for the evaporator. Evaporation and calorimetry testing of surrogate samples containing 2000 ppm of Ultima Gold{trademark} AB LSC in 8 M nitric acid have been completed. These experiments showed that although reactions between nitric acid and the organic components do occur, they do not appear to pose a significant hazard for runaway reactions or generation of energetic compounds in canyon evaporators. The amount of off-gas generated was relatively modest and appeared to be well within the venting capacity of the H-Canyon evaporators. A significant fraction of the organic components likely survives the evaporation process primarily as non-volatile components that are not expected to represent any new process concerns during downstream operations such as neutralization. Laboratory Waste solutions containing minor amounts of DIN can be safely received, stored, transferred, and processed through the canyon waste evaporator.

Kyser, E.; Fondeur, F.; Crump, S.

2011-12-21T23:59:59.000Z

356

SIMULATED WASTE TESTING OF GLYCOLATE IMPACTS ON THE 2H-EVAPORATOR SYSTEM  

SciTech Connect

Glycolic acid is being studied as a total or partial replacement for formic acid in the Defense Waste Processing Facility (DWPF) feed preparation process. After implementation, the recycle stream from DWPF back to the high-level waste tank farm will contain soluble sodium glycolate. Most of the potential impacts of glycolate in the tank farm were addressed via a literature review, but several outstanding issues remained. This report documents the non-radioactive simulant tests impacts of glycolate on storage and evaporation of Savannah River Site high-level waste. The testing for which non-radioactive simulants could be used involved the following: the partitioning of glycolate into the evaporator condensate, the impacts of glycolate on metal solubility, and the impacts of glycolate on the formation and dissolution of sodium aluminosilicate scale within the evaporator. The following are among the conclusions from this work: ? Evaporator condensate did not contain appreciable amounts of glycolate anion. Of all tests, the highest glycolate concentration in the evaporator condensate was 0.38 mg/L. A significant portion of the tests had glycolate concentration in the condensate at less than the limit of quantification (0.1 mg/L). ? At ambient conditions, evaporator testing did not show significant effects of glycolate on the soluble components in the evaporator concentrates. ? Testing with sodalite solids and silicon containing solutions did not show significant effects of glycolate on sodium aluminosilicate formation or dissolution.

Martino, C. J.

2013-08-13T23:59:59.000Z

357

Plasma-Assisted Co-evaporation of S and Se for Wide Band Gap Chalcopyrite Photovoltaics: Final Subcontract Report, December 2001 -- April 2005  

DOE Green Energy (OSTI)

In this work, ITN Energy Systems (ITN) and lower-tier subcontractor Colorado School of Mines (CSM) explore the replacement of the molecular chalcogen precursors during deposition (e.g., Se2 or H2Se) with more reactive chalcogen monomers or radicals (e.g., Se). Molecular species are converted to atomic species in a low-pressure inductively coupled plasma (ICP). This program explored the use of plasma-activated chalcogen sources in CIGS co-evaporation to lower CIGS deposition temperature, increase utilization, increase deposition rate, and improve S:Se stoichiometry control. Plasma activation sources were designed and built, then operated and characterized over a wide range of conditions. Optical emission and mass spectrometry data show that chalcogens are effectively dissociated in the plasma. The enhanced reactivity achieved by the plasma processing was demonstrated by conversion of pre-deposited metal films to respective chalcogen-containing phases at low temperature and low chalcogen flux. The plasma-assisted co-evaporation (PACE) sources were also implemented in CIGS co-evaporation. No benefit from PACE was observed in device results, and frequent deposition failures occurred.

Repins, I.; Wolden, C.

2005-08-01T23:59:59.000Z

358

An area-dependent wind function for estimating open water evaporation using land-based meteorological data  

Science Conference Proceedings (OSTI)

We propose a generally applicable formula for estimating evaporation rate from open water bodies which utilizes readily available land-based meteorological data. We follow the well-known aerodynamic approach in which evaporation rate is modelled as the ... Keywords: Evaporation, Lake, Open water, Pond, Uncertainty, Water body, Wind function, Wind speed

D. L. McJannet; I. T. Webster; F. J. Cook

2012-05-01T23:59:59.000Z

359

Evaporation of Picolitre Droplets on Surfaces with a Range of Wettabilities and Thermal Conductivities  

E-Print Network (OSTI)

of inkjet droplets ranges between 10 µm and 100 µm. Evaporation should still be limited by dif- fusion at this scale. Convection occurs in evaporating sessile droplets [12] where, in order to conserve mass, evaporating liquid is replenished by a convective... at 10 W for 5 minutes at different lo- cations in the reactor, resulting in different roughnesses. S1 showed a root mean squared (rms) roughness of ?130 nm by AFM (Digital Instruments Nanoscope III scanning probe microscope), whereas S2 had an RMS...

Talbot, E.L.; Berson, A.; Brown, P.S.; Bain, C.D.

2012-01-01T23:59:59.000Z

360

Design and testing a solar cooling system employing liquid desiccants: Dehumidifier experiments in Colorado State University Solar House II: Final report, 1986--1987  

DOE Green Energy (OSTI)

A nominal 3-ton (10.5-kW) lithium bromide, open-cycle desiccant cooling system has been designed, installed, and operated. This experimental system dehumidifies ambient air in a packed bed utilizing an aqueous solution of lithium bromide. The absorbent solution is distributed by spray nozzles and flows countercurrent to the air. The dilute solution exiting the dehumidifier is concentrated in a packed bed regenerator by solar heated air. The strong solution is cooled by two heat exchangers before reentering the dehumidifier. Provisions to simulate conditions of high ambient humidity and temperature have been made. Experiments on the dehumidifier operating in a decoupled mode (without countercurrent regenerator operation) have been carried out. Cooling capacities in the range of 1.0--4.0 refrigeration tons have been achieved, depending upon the operating conditions. The effect of different independent variables on the capacity of the dehumidifier has been studied. An empirical equation correlating the variables have been obtained by statistical analysis of the data. The equation obtained indicates that the capacity of the dehumidifier depends strongly on the solution concentration, solution flow rate, air inlet temperature and the air humidity. Two other variables studied, the solution inlet temperature and the air flow rate, did not affect the cooling capacity greatly. The dependence of condensation rate on each of the variables is analyzed. 22 refs., 17 figs., 3 tabs.

Lenz, T.G.; Loef, G.O.G.; Patnaik, S.

1987-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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.


361

Dew Point Evaporative Comfort Cooling: Report and Summary Report  

Science Conference Proceedings (OSTI)

The project objective was to demonstrate the capabilities of the high-performance multi-staged IEC technology and its ability to enhance energy efficiency and interior comfort in dry climates, while substantially reducing electric-peak demand. The project was designed to test 24 cooling units in five commercial building types at Fort Carson Army Base in Colorado Springs, Colorado.

Dean, J.; Herrmann, L.; Kozubal, E.; Geiger, J.; Eastment, M.; Slayzak, S.

2012-11-01T23:59:59.000Z

362

Comparative Study of Various Formulations of Evaporations from Bare Soil Using In Situ Data  

Science Conference Proceedings (OSTI)

Vajious formulations of surface evaporation are tested against in situ data collected over a plot of loamy bare ground. Numerical simulations lasting seven days are compared with observations of near-surface water content and cumulative ...

J. F. Mahfouf; J. Noilhan

1991-09-01T23:59:59.000Z

363

Modeling the Effect of Land Surface Evaporation Variability on Precipitation Variability. Part I: General Response  

Science Conference Proceedings (OSTI)

This is the first of a two-part article that investigates the impact of land surface evaporation variability on the interannual variability of precipitation and compares it with the impact caused by sea surface temperature variability. Previous ...

Oreste Reale; Paul Dirmeyer

2002-08-01T23:59:59.000Z

364

Estimating the Role of Local Evaporation in Precipitation for a Two-Dimensional Region  

Science Conference Proceedings (OSTI)

Budyko's model for estimating the contributions of locally evaporated and advected moisture to regional precipitation is extended to two dimensions. It is shown that a simple extension by analogy of the one-dimensional Budyko's formula to a two-...

Georgy I. Burde; Abraham Zangvil; Peter J. Lamb

1996-06-01T23:59:59.000Z

365

Wind-evaporation feedback, angular momentum conservation, and the abrupt onset of monsoons  

E-Print Network (OSTI)

This thesis examines the mechanisms responsible for the abrupt onset of monsoon circulations, focusing on the role played by wind-evaporation feedback and its interaction with angular momentum conserving flow. The first ...

Boos, William R. (William Ronald), 1975-

2008-01-01T23:59:59.000Z

366

Numerical Investigations of the Roles of Radiative and Evaporative Feedbacks in Stratocumulus Entrainment and Breakup  

Science Conference Proceedings (OSTI)

When the surface buoyancy flux is small and the shear is weak, turbulence circulations within a stratus-topped boundary layer are driven by two buoyancy-generating processes at cloud top: radiative cooling and evaporative cooling. These two ...

Chin-Hoh Moeng; Don H. Lenschow; David A. Randall

1995-08-01T23:59:59.000Z

367

Examining Rapid Onset Drought Development Using the Thermal Infrared–Based Evaporative Stress Index  

Science Conference Proceedings (OSTI)

Reliable indicators of rapid drought onset can help to improve the effectiveness of drought early warning systems. In this study, the evaporative stress index (ESI), which uses remotely sensed thermal infrared imagery to estimate ...

Jason A. Otkin; Martha C. Anderson; Christopher Hain; Iliana E. Mladenova; Jeffrey B. Basara; Mark Svoboda

2013-08-01T23:59:59.000Z

368

Global Variations in Oceanic Evaporation (1958–2005): The Role of the Changing Wind Speed  

Science Conference Proceedings (OSTI)

Global estimates of oceanic evaporation (Evp) from 1958 to 2005 have been recently developed by the Objectively Analyzed Air–Sea Fluxes (OAFlux) project at the Woods Hole Oceanographic Institution (WHOI). The nearly 50-yr time series shows that ...

Lisan Yu

2007-11-01T23:59:59.000Z

369

Comparing Evaporative Sources of Terrestrial Precipitation and Their Extremes in MERRA Using Relative Entropy  

Science Conference Proceedings (OSTI)

A quasi-isentropic back trajectory scheme is applied to output from the Modern Era Retrospective-analysis for Research and Applications and a land-only replay with corrected precipitation to estimate surface evaporative sources of moisture ...

Paul A. Dirmeyer; Jiangfeng Wei; Michael G. Bosilovich; David M. Mocko

370

Sensitivity of Annual Evaporation to Soil and Root Properties in Two Models of Contrasting Complexity  

Science Conference Proceedings (OSTI)

Simulations of soil water and evapotranspiration with physically based models at broad scales vary in both complexity of processes modeled and in parameterization of soil and root properties. Sensitivity of annual evaporation Eann to some of ...

C. A. Federer; C. Vörösmarty; B. Fekete

2003-12-01T23:59:59.000Z

371

Establishing feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys  

DOE Green Energy (OSTI)

The solar updraft and a natural evaporative downdraft tower built onto an existing residence structure and a greenhouse were completed and operating. Performance data for the hottest days of June, July, and August, 1985 are included. (MHR)

Cunningham, W.A.; Migon, G.V.

1985-01-01T23:59:59.000Z

372

Trends of Calculated and Simulated Actual Evaporation in the Yangtze River Basin  

Science Conference Proceedings (OSTI)

Actual evaporation in the Yangtze River basin is calculated by the complementary relationship approach—that is, the advection–aridity (AA) model with parameter validation from 1961 to 2007—and simulated by the general circulation model (GCM) ...

Yanjun Wang; Bo Liu; Buda Su; Jianqing Zhai; Marco Gemmer

2011-08-01T23:59:59.000Z

373

The Melting Layer: A Laboratory Investigation of Ice Particle Melt and Evaporation near 0°C  

Science Conference Proceedings (OSTI)

Melting, freezing, and evaporation of individual and aggregates of snow crystals are simulated in the laboratory under controlled temperature, relative humidity, and air velocity. Crystals of selected habit are grown on a vertical filament and ...

R. G. Oraltay; J. Hallett

2005-02-01T23:59:59.000Z

374

Estimating the Evaporative Cooling Bias of an Airborne Reverse Flow Thermometer  

Science Conference Proceedings (OSTI)

Airborne reverse flow immersion thermometers were designed to prevent sensor wetting in cloud. Yet there is strong evidence that some wetting does occur and therefore also sensor evaporative cooling as the aircraft exits a cloud. Numerous ...

Yonggang Wang; Bart Geerts

2009-01-01T23:59:59.000Z

375

An Automated Microlysimeter to Study Dew Formation and Evaporation in Arid and Semiarid Regions  

Science Conference Proceedings (OSTI)

The development of a simple and low-cost portable weighing microlysimeter that makes use of a load cell for automated recording and for studying daily dew formation, rate of accumulation, and subsequent evaporation in arid or semiarid regions ...

Bert G. Heusinkveld; Simon M. Berkowicz; Adrie F. G. Jacobs; Albert A. M. Holtslag; Willy C. A. M. Hillen

2006-08-01T23:59:59.000Z

376

Floating dry cooling: a competitive alternative to evaporative cooling in a binary cycle geothermal power plant  

DOE Green Energy (OSTI)

The application of the floating cooling concept to non-evaporative and evaporative atmospheric heat rejection systems was studied as a method of improving the performance of geothermal powerplants operating upon medium temperature hydrothermal resources. The LBL thermodynamic process computer code GEOTHM is used in the case study of a 50 MWe isobutane binary cycle power plant at Heber, California. It is shown that operating a fixed capacity plant in the floating cooling mode can generate significantly more electrical energy at a higher thermodynamic efficiency and reduced but bar cost for approximately the same capital investment. Floating cooling is shown to benefit a plant which is dry cooled to an even greater extent than the same plant operating with an evaporative heat rejection system. Results of the Heber case study indicate that a dry floating cooling geothermal binary cycle plant can produce energy at a bus bar cost which is competitive with the cost of energy associated with evaporatively cooled systems.

Pines, H.S.; Green, M.A.; Pope, W.L.; Doyle, P.A.

1978-07-01T23:59:59.000Z

377

What Drives the Variability of Evaporative Demand across the Conterminous United States?  

Science Conference Proceedings (OSTI)

To understand the sources of temporal and spatial variability of atmospheric evaporative demand across the conterminous United States (CONUS), a mean-value, second-moment uncertainty analysis is applied to a spatially distributed dataset of daily ...

Michael Hobbins; Andrew Wood; David Streubel; Kevin Werner

2012-08-01T23:59:59.000Z

378

Use of DOE-2 to Evaluate Evaporative Cooling in Texas Correctional Facilities  

E-Print Network (OSTI)

This study investigates the feasibility of using direct and indirect evaporative cooling systems for correctional facilities in two different Texas climatic regions with the DOE-2.1E hourly energy simulation program. The analysis is based on adding user defined functions to the DOE-2 SYSTEMS subprogram to simulate direct and indirect evaporative cooling configurations. The DOE-2 program was run with two weather tapes, one for Kingsville, Texas and one for Abilene, Texas during April, July, and October to resemble neutral, summer and winter weather conditions. The results showed that direct evaporative cooling is applicable in April for Abilene and October for Kingsville. The indirect evaporative cooling is feasible in July for Abilene and April for Kingsville.

Saman, N.; Heneghan, T.; Bou-Saada, T. E.

1996-01-01T23:59:59.000Z

379

A New Metric for Estimating the Influence of Evaporation on Seasonal Precipitation Rates  

Science Conference Proceedings (OSTI)

The objective of this paper is to introduce a diagnostic metric—termed the local-convergence ratio—that can be used to quantify the contribution of evaporation (and transpiration) to the atmospheric hydrologic cycle, and precipitation in ...

Bruce T. Anderson; Guido Salvucci; Alex C. Ruane; John O. Roads; Masao Kanamitsu

2008-06-01T23:59:59.000Z

380

Evaporation and Condensation of Large Droplets in the Presence of Inert Admixtures Containing Soluble Gas  

Science Conference Proceedings (OSTI)

In this study the mutual influence of heat and mass transfer during gas absorption and evaporation or condensation on the surface of a stagnant droplet in the presence of inert admixtures containing noncondensable soluble gas is investigated ...

T. Elperin; A. Fominykh; B. Krasovitov

2007-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

The Sensitivity of the ECMWF Model to the Parameterization of Evaporation from the Tropical Oceans  

Science Conference Proceedings (OSTI)

Stimulated by the results of a simple SST anomaly experiment with the ECMWF forecast model, a study was carried out to examine the model parameterization of evaporation from the tropica] oceans. In earlier versions of the model, these fluxes were ...

M. J. Miller; A. C. M. Beljaars; T. N. Palmer

1992-05-01T23:59:59.000Z

382

An experimental study of evaporative cooling from liquid droplets impinging on a hot surface  

E-Print Network (OSTI)

We have performed a series of experiments to characterize the different regimes observed in drop impacts during evaporative cooling of heated surfaces. We found four regimes which were named splashing, fizzing, flat film, ...

Koveal, Catherine Helene

2005-01-01T23:59:59.000Z

383

A New Shipborne Microwave Refractometer for Estimating the Evaporation Flux at the Sea Surface  

Science Conference Proceedings (OSTI)

After a brief description of humidity measurement and a short presentation of methods of microwave refractometry for evaporation flux, a new X-band refractometer system is presented. Based on a new design and a new material for the microwave ...

J.-Y. Delahaye; C. Guerin; J. P. Vinson; H. Dupuis; A. Weill; H. Branger; L. Eymard; J. Lavergnat; G. Lachaud

2001-03-01T23:59:59.000Z

384

Triode electron bombardment evaporation source for ultrahigh vacuum thin film deposition  

Science Conference Proceedings (OSTI)

A new electron bombardment evaporation source for ultrahigh vacuum (UHV) thin film deposition is presented. It is based on an original electrodes configuration (modeled on that of a vacuum triode) featuring

R. Verucchi; S. Nannarone

2000-01-01T23:59:59.000Z

385

Fusion-evaporation reactions: a tool for gamma-ray spectroscopy on light nuclei  

SciTech Connect

We have studied the weak-decay channels of fusion/evaporation in light projectile/light target systems in order to provide reliable predictions for gamma-spectroscopy experiments.

Gibelin, J.; Phair, L.; Wiedeking, M.; Clark, R. M.; Cromaz, M.; Deleplanque, M.-A.; Fallon, P.; Lee, I.-Y.; Macchiavelli, A. O.; McMahan, M. A. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Bernstein, L. A.; Burke, J. T.; Bleuel, D. L.; Lesher, S. R. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Hatarik, R. [Rutgers University, New Brunswick, NJ 08854 (United States); Lake, P. T.; Rodriguez-Vieitez, E.; Moretto, L. G. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); University of California, Berkeley CA 94720 (United States); Lyles, B. F. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); University of California, Berkeley CA 94720 (United States)

2008-04-17T23:59:59.000Z

386

LITERATURE REVIEW ON IMPACT OF GLYCOLATE ON THE 2H EVAPORATOR AND THE EFFLUENT TREATMENT FACILITY  

Science Conference Proceedings (OSTI)

Glycolic acid (GA) is being studied as an alternate reductant in the Defense Waste Processing Facility (DWPF) feed preparation process. It will either be a total or partial replacement for the formic acid that is currently used. A literature review has been conducted on the impact of glycolate on two post-DWPF downstream systems - the 2H Evaporator system and the Effluent Treatment Facility (ETF). The DWPF recycle stream serves as a portion of the feed to the 2H Evaporator. Glycolate enters the evaporator system from the glycolate in the recycle stream. The overhead (i.e., condensed phase) from the 2H Evaporator serves as a portion of the feed to the ETF. The literature search revealed that virtually no impact is anticipated for the 2H Evaporator. Glycolate may help reduce scale formation in the evaporator due to its high complexing ability. The drawback of the solubilizing ability is the potential impact on the criticality analysis of the 2H Evaporator system. It is recommended that at least a theoretical evaluation to confirm the finding that no self-propagating violent reactions with nitrate/nitrites will occur should be performed. Similarly, identification of sources of ignition relevant to glycolate and/or update of the composite flammability analysis to reflect the effects from the glycolate additions for the 2H Evaporator system are in order. An evaluation of the 2H Evaporator criticality analysis is also needed. A determination of the amount or fraction of the glycolate in the evaporator overhead is critical to more accurately assess its impact on the ETF. Hence, use of predictive models like OLI Environmental Simulation Package Software (OLI/ESP) and/or testing are recommended for the determination of the glycolate concentration in the overhead. The impact on the ETF depends on the concentration of glycolate in the ETF feed. The impact is classified as minor for feed glycolate concentrations {le} 33 mg/L or 0.44 mM. The ETF unit operations that will have minor/major impacts are chlorination, pH adjustment, 1st mercury removal, organics removal, 2nd mercury removal, and ion exchange. For minor impacts, the general approach is to use historical process operations data/modeling software like OLI/ESP and/or monitoring/compiled process operations data to resolve any uncertainties with testing as a last resort. For major impacts (i.e., glycolate concentrations > 33 mg/L or 0.44 mM), testing is recommended. No impact is envisaged for the following ETF unit operations regardless of the glycolate concentration - filtration, reverse osmosis, ion exchange resin regeneration, and evaporation.

Adu-Wusu, K.

2012-05-10T23:59:59.000Z

387

Projected Benefits of New Residential Evaporative Cooling Systems: Progress Report #2  

SciTech Connect

The use of conventional evaporative cooling has rapidly declined in the United States despite the fact that it has high potential for energy savings in dry climates. Evaporative systems are very competitive in terms of first cost and provide significant reductions in operating energy use, as well as peak-load reduction benefits. Significant market barriers still remain and can be addressed through improved systems integration. This report investigates the first of these approaches, exploring innovative components. The U.S. Department of Energy (DOE) Building America research teams are investigating the use of two promising new pieces of residential cooling equipment that employ evaporative cooling as a part of their system design. The OASys unit, which is a combination of direct and indirect evaporative cooling stages developed by Davis Energy Group (DEG) and manufactured by Speakman CRS, is used to ultimately provide outside air to the living space. The outdoor air provided is indirectly and directly evaporatively cooled in two stages to a condition that can be below the wet-bulb (wb) temperature of the outside air, thus outperforming a conventional single-stage direct evaporative cooler.

Kutscher, C.; Eastment, M.; Hancock, E.; Reeves, P.

2006-10-01T23:59:59.000Z

388

Arabidopsis AtSerpin1, Crystal Structure and in Vivo Interaction with Its Target Protease RESPONSIVE TO DESICCATION-21 (RD21)  

Science Conference Proceedings (OSTI)

In animals, protease inhibitors of the serpin family are associated with many physiological processes, including blood coagulation and innate immunity. Serpins feature a reactive center loop (RCL), which displays a protease target sequence as a bait. RCL cleavage results in an irreversible, covalent serpin-protease complex. AtSerpin1 is an Arabidopsis protease inhibitor that is expressed ubiquitously throughout the plant. The x-ray crystal structure of recombinant AtSerpin1 in its native stressed conformation was determined at 2.2 {angstrom}. The electrostatic surface potential below the RCL was found to be highly positive, whereas the breach region critical for RCL insertion is an unusually open structure. AtSerpin1 accumulates in plants as a full-length and a cleaved form. Fractionation of seedling extracts by nonreducing SDS-PAGE revealed the presence of an additional slower migrating complex that was absent when leaves were treated with the specific cysteine protease inhibitor l-trans-epoxysuccinyl-l-leucylamido (4-guanidino)butane. Significantly, RESPONSIVE TO DESICCATION-21 (RD21) was the major protease labeled with the l-trans-epoxysuccinyl-l-leucylamido (4-guanidino)butane derivative DCG-04 in wild type extracts but not in extracts of mutant plants constitutively overexpressing AtSerpin1, indicating competition. Fractionation by nonreducing SDS-PAGE followed by immunoblotting with RD21-specific antibody revealed that the protease accumulated both as a free enzyme and in a complex with AtSerpin1. Importantly, both RD21 and AtSerpin1 knock-out mutants lacked the serpin-protease complex. The results establish that the major Arabidopsis plant serpin interacts with RD21. This is the first report of the structure and in vivo interaction of a plant serpin with its target protease.

Lampl, Nardy; Budai-Hadrian, Ofra; Davydov, Olga; Joss, Tom V.; Harrop, Stephen J.; Curmi, Paul M.G.; Roberts, Thomas H.; Fluhr, Robert (WIS-I); (Macquarie); (New South)

2010-05-25T23:59:59.000Z

389

Procedure for Applying an Open-Cycle Heat Pump to An Existing Evaporator  

E-Print Network (OSTI)

An open-cycle heat pump, or mechanical vapor compression (MVC) system, is often an attractive technique for increasing the energy efficiency of an evaporator. With proper design, an MVC system is capable of dramatic cost savings when retrofitted to an existing evaporator. This is especially true if the evaporator is a single or double effect design. Many such evaporators were built when energy was cheap, or because a particular process is not amenable to modern designs incorporating many effects. Advances in compressor design have made MVC applicable to a broader range of processes than ever before. This paper discusses the basic steps required to apply MVC as a retrofit to an existing evaporator. Because of their importance to identification of candidate applications, this paper emphasizes the preliminary analysis and premonitoring steps. For illustration purposes the authors refer to an MVC retrofit in progress at a plant operated by Kraft, Inc. The project is cofunded by the New York State Energy Research and Development Authority (Albany, NY), and will serve as a demonstration site to facilitate increased adoption of MVC by other industrial firms.

Wagner, J. R.; Brush, F. C.

1984-01-01T23:59:59.000Z

390

Economic and Technical Tradeoffs Between Open and Closed Cycle Vapor Compression Evaporators  

E-Print Network (OSTI)

Evaporators are used extensively in the chemical, pulp and paper, food and beverage, and related industries. Mechanical vapor recompression (MVR) evaporators are a type using an open heat pump cycle with steam as the working fluid. The technology is widely used and time-proven. Closed cycle vapor compression is an emerging technology. A secondary working fluid such as a halocarbon is used in a closed heat pump cycle to transfer heat from the steam condenser to the hottest surface. Advantages of closed cycle evaporation include flexibility in working fluid selection, potential savings in compressor first cost, and isolation of the compressor from potentially corrosive or troublesome gases and liquid droplets in the suction vapor. A major disadvantage of closed cycle evaporation is that the driving force developed by the compressor (temperature difference) must be shared between two heat transfer surfaces, vs. one in the open cycle design. This paper explores the advantages and disadvantages of open and closed cycle evaporators. Factors considered include working fluid physical properties and thermodynamics, compressor operating limits and cost, and surface area sizing and cost.

Timm, M. L.

1986-06-01T23:59:59.000Z

391

Preliminary experimental studies with seawater on OTEC spout evaporator thermal effectiveness and phase transition in upcomer  

Science Conference Proceedings (OSTI)

An experimental open-cycle ocean thermal energy conversion (OC-OTEC) test facility has been erected to perform spout evaporator experiments with seawater. The facility, located at Ke-ahole Point, Kona, Hawaii, consists of a spout evaporator, a spray condenser and an on-line deaerator. Warm seawater at 25-27/sup 0/C from 8 m depth and cold deep seawater at 7-10/sup 0/C from 580 m depth is available throughout the year to the facility. The results of thermal effectiveness tests are reported. The error due to instrumental uncertainties in thermal effectiveness measurements has been estimated to be of the order +-5.5 percent. The effect of design parameters; spout height, spout diameter and liquid loading on thermal effectiveness have been observed and compared with the existing theoretical predictions. A modified thermodynamic approach is proposed to evaluate average heat transfer characteristics of spout evaporators using a three component heat transfer coefficient approach. It adequately describes heat transfer characteristics of the spout evaporator under study. Results essentially agree with data obtained by others for fresh water, but clearly indicate the need for improvement of the existing model to take into account a number of identified factors associated with the real life OC-OTEC conditions, such as the transience in evaporator performance associated with the ocean-generated flow and pressure fluctuations and effects of noncondensable gases.

Sonwalkar, N.; Larsen-Basse, J.

1987-01-01T23:59:59.000Z

392

Applications of geothermal resources in the evaporation and crystallization industry. Final report, September 1976--October 1977  

DOE Green Energy (OSTI)

The objective in this study was to determine the technical and economic feasibility of using low-temperature geothermal energy (hot brines) in place of steam from conventional sources in the evaporation and crystallization industry. A survey of major industries was carried out in order to choose three industries that were significant users of energy, could utilize geothermal brine, and demonstrate the broad range of industrial evaporation and crystallization operations. The selected industries were the preserved fruit and vegetable, sugar and confectionary products, and chemical industries. From among each of the selected industries, an example case was chosen for technical and economic evaluation. This evaluation included use of the ''feed-and-bleed'' process for energy extraction from the low-temperature geothermal brine. This process was chosen as the best process to use because it provides one of the most efficient means of utilizing geothermal brine in evaporation/crystallization operations. This study concludes that, under certain conditions, geothermal energy could be used economically in the evaporation and crystallization industry. The factors that would most affect cost include geothermal resource characteristics (well flow, temperature, and distance of transportation); the energy extraction process chosen (the feed-and-bleed process uses the least amount of brine); and the duration of the evaporation/crystallization process. A program to aid in implementing the use of geothermal energy is included.

May, S.C.; Basuino, D.J.; Doyle, P.T.; Rogers, A.N.

1977-10-01T23:59:59.000Z

393

Literature survey of heat transfer enhancement techniques in refrigeration applications  

Science Conference Proceedings (OSTI)

A survey has been performed of the technical and patent literature on enhanced heat transfer of refrigerants in pool boiling, forced convection evaporation, and condensation. Extensive bibliographies of the technical literature and patents are given. Many passive and active techniques were examined for pure refrigerants, refrigerant-oil mixtures, and refrigerant mixtures. The citations were categorized according to enhancement technique, heat transfer mode, and tube or shell side focus. The effects of the enhancement techniques relative to smooth and/or pure refrigerants were illustrated through the discussion of selected papers. Patented enhancement techniques also are discussed. Enhanced heat transfer has demonstrated significant improvements in performance in many refrigerant applications. However, refrigerant mixtures and refrigerant-oil mixtures have not been studied extensively; no research has been performed with enhanced refrigerant mixtures with oil. Most studies have been of the parametric type; there has been inadequate examination of the fundamental processes governing enhanced refrigerant heat transfer, but some modeling is being done and correlations developed. It is clear that an enhancement technique must be optimized for the refrigerant and operating condition. Fundamental processes governing the heat transfer must be examined if models for enhancement techniques are to be developed; these models could provide the method to optimize a surface. Refrigerant mixtures, with and without oil present, must be studied with enhancement devices; there is too little known to be able to estimate the effects of mixtures (particularly NARMs) with enhanced heat transfer. Other conclusions and recommendations are offered.

Jensen, M.K.; Shome, B. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Mechanical Engineering, Aeronautical Engineering and Mechanics

1994-05-01T23:59:59.000Z

394

The Effect of Reduced Evaporator Air Flow on the Performance of a Residential Central Air Conditioner  

E-Print Network (OSTI)

This paper discusses the measured degradation in performance of a residential air conditioning system operating under reduced evaporator air flow. Experiments were conducted using a R-22 three-ton split-type cooling system with a short-tube orifice expansion device. Results are presented here for a series of tests in which the evaporator air flow was reduced from 25 to 90% below what is normally recommended for this air conditioner. At present, very little information is available which quantifies the performance of a residential cooling system operating under degraded conditions such as reduced evaporator air flow. Degraded performance measurements can provide information which could help electric utilities evaluate the potential impact of system-wide maintenance programs.

Palani, M.; O'Neal, D.; Haberl, J.

1992-05-01T23:59:59.000Z

395

Vacuum-evaporated ferroelectric films and heterostructures of vinylidene fluoride/trifluoroethylene copolymer  

SciTech Connect

The potential of the vacuum method for preparing ferroelectric films and photonic heterostructures from organic materials is studied. Vacuum-evaporated films of fluoropolymers and heterostructures on their basis are obtained and their ferroelectric and spectral properties are studied. In particular, homogeneous films of the well-known piezoelectric polymer polyvinylidene fluoride and ferroelectric material vinylidene fluoride/trifluoroethylene copolymer (P(VDF/TFE)) are produced. Experimental studies of vacuum-evaporated P(VDF/TFE) films confirmed their ferroelectric properties. The heterostructures composed of alternating layers of P(VDF/TFE) copolymer molecules and azodye molecules are fabricated by vacuum evaporation. Owing to the controlled layer thickness and a significant difference in the refractive indices of the P(VDF/TFE) copolymer and azodyes, these heterostructures exhibit properties of photonic crystals. This finding is confirmed by the occurrence of a photonic band in the absorption spectra of the heterostructures.

Draginda, Yu. A., E-mail: lbf@ns.crys.ras.ru; Yudin, S. G.; Lazarev, V. V.; Yablonskii, S. V.; Palto, S. P. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

2012-05-15T23:59:59.000Z

396

Evaporation and wetting dynamics of sessile water droplets on submicron-scale patterned silicon hydrophobic surfaces  

SciTech Connect

The evaporation characteristics of 1 l sessile water droplets on hydrophobic surfaces are experimentally examined. The proposed hydrophobic surfaces are composed of submicron diameter and 4.2- m-height silicon post arrays. A digital image analysis algorithm was developed to obtain time-dependent contact angles, contact diameters, and center heights for both non-patterned polydimethylsiloxane (PDMS) surfaces and patterned post array surfaces, which have the same hydrophobic contact angles. While the contact angles exhibit three distinct stages during evaporation in the non-patterned surface case, those in the patterned silicon post array surface case decrease linearly. In the case of post array hydrophobic surfaces, the initial contact diameter remains unchanged until the portion of the droplet above the posts completely dries out. The edge shrinking velocity of the droplet shows nonlinear characteristics, and the velocity magnitude increases rapidly near the last stage of evaporation.

Choi, Chang Kyoung [Michigan Technological University; Shin, Dong Hwan [Chung-Ang University; Lee, Seong Hyuk [Chung-Ang University; Retterer, Scott T [ORNL

2010-01-01T23:59:59.000Z

397

Spallation process with simultaneous multi-particle emission in nuclear evaporation  

SciTech Connect

High energy probes have been used currently to explore nuclear reaction mechanism and nuclear structure. The spallation process governs the reaction process around 1 GeV energy regime. A new aspect introduced here to describe the nuclear reaction is the in-medium nucleonnucleon collision framework. The nucleon-nucleon scattering is kinematically treated by using an effective mass to represent the nuclear binding. In respect to the evaporation phase of the reaction, we introduce the simultaneous particles emission decay. This process becomes important due to the rise of new channels at high excitation energy regime of the compound nucleus. As results, the particles yields in the rapid and evaporation phases are obtained and compared to experimental data. The effect and relevance of these simultaneous emission processes in the evaporation chain is also discussed.

Santos, B. M. [Instituto de Fisica/UFF - Av. Gal. Milton Tavares de Souza, Praia Vermelha, Niteroi - RJ (Brazil); Goncalves, M. [Comissao Nacional de Energia Nuclear/CNEN - Rua Gal Severiano, nr. 90, Botafogo - RJ (Brazil); Assis, L. P. G. de; Duarte, S. B. [Centro Brasileiro de Pesquisas Fisicas/CBPF - Rua Dr. Xavier Sigaud, nr.150, Urca - RJ (Brazil)

2013-05-06T23:59:59.000Z

398

Evaporation system and method for gas jet deposition of thin film materials  

DOE Patents (OSTI)

A method and apparatus for depositing thin films of materials such as metals, oxides and nitrides at low temperature relies on a supersonic free jet of inert carrier gas to transport vapor species generated from an evaporation source to the surface of a substrate. Film deposition vapors are generated from solid film precursor materials, including those in the form of wires or powders. The vapor from these sources is carried downstream in a low pressure supersonic jet of inert gas to the surface of a substrate where the vapors deposit to form a thin film. A reactant gas can be introduced into the gas jet to form a reaction product with the evaporated material. The substrate can be moved from the gas jet past a gas jet containing a reactant gas in which a discharge has been generated, the speed of movement being sufficient to form a thin film which is chemically composed of the evaporated material and reactant gases.

Schmitt, Jerome J. (New Haven, CT); Halpern, Bret L. (Bethany, CT)

1994-01-01T23:59:59.000Z

399

Optimization of hybrid-water/air-cooled condenser in an enhanced turbine  

Open Energy Info (EERE)

Optimization of hybrid-water/air-cooled condenser in an enhanced turbine Optimization of hybrid-water/air-cooled condenser in an enhanced turbine geothermal ORC system Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Optimization of hybrid-water/air-cooled condenser in an enhanced turbine geothermal ORC system Project Type / Topic 1 Recovery Act: Enhanced Geothermal Systems Component Research and Development/Analysis Project Type / Topic 2 Air-Cooling Project Description The technical approaches are: -UTRC shall develop a lab-based analysis of hybrid-water/air-cooled condensers with minimal water consumption, focusing on combined mist evaporative pre-cooling and mist deluge evaporative cooling technology applied to microchannel heat exchangers. Models to predict evaporative cooling performance will be validated by sub-scale testing. The predicted performance will be compared to that of state-of-the-art commercial evaporative coolers. -UTRC shall analyze the interaction of turbine design and cooling needs and specifically address how an enhanced turbine, which features variable nozzles and diffuser boundary layer suction, would further improve the ORC system performance and enable full utilization of the hybrid-cooled system. UTRC shall design, procure and test the enhanced turbine in an existing 200 kW geothermal ORC system for a technology demonstration. -UTRC shall complete a detailed design of the hybrid-cooled geothermal ORC system with an enhanced turbine that complies with its performance, cost, and quality requirements, and use this system design to prescribe subsystem/component technology requirements and interfaces. UTRC shall optimize UTC's PureCycle® geothermal ORC system integrated with a hybrid-water/air-cooled condenser and an enhanced turbine for net power output, efficiency and water consumption. -UTRC shall analyze the feasibility of addressing pure water supply for hybrid-water/aircooled condenser by using geothermal-driven Liquid-Gap-Membrane-Distillation (LGMD) technology, as an alternative to conventional Reverse Osmosis/De-Ionized treatment.

400

Advances in the application of passive down-draft evaporative cooling technology in the cooling of buildings.  

E-Print Network (OSTI)

??A passive down-draft evaporative cooling (PDEC) tower is a component that is designed to capture the wind at the top of a tower and cool… (more)

Kang, Daeho

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

Demolition of the waste evaporator facility at Oak Ridge National Laboratory  

SciTech Connect

Lockheed Martin Energy Systems, in conjunction with Allied Technology Group, Inc., successfully executed the decommissioning of a former waste evaporator facility at ONRL. This project was conducted as a non-time critical removal action under CERCLA. The decommissioning alternative selected for the Waste Evaporator Facility was partial dismantlement. This alternative provided for the demolition of all above-grade structures; concrete which did not exceed pre-established radiological levels were eligible for placement in the below-grade portion of the facility. This project demonstrated a coordinated team approach that allowed the successful completion of one of the first full-scale decommissioning projects at ORNL.

Mandry, G.J. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States); Becker, C.L. [Allied Technology Group, Inc., Oak Ridge, TN (United States)

1997-08-01T23:59:59.000Z

402

Feasibility Study – Using a Solar Evaporator to Reduce the Metalworking Fluid (MWF) Waste Stream  

DOE Green Energy (OSTI)

A solar evaporator was designed, built, and operated to reduce the water-based metalworking fluid waste stream. The evaporator was setup in Waste Management’s barrel lot inside one of the confinement areas. The unit processed three batches of waste fluid during the prototype testing. Initial tests removed 13% of the fluid waste stream. Subsequent modifications to the collector improved the rate to almost 20% per week. Evaluation of the risk during operation showed that even a small spill when associated with precipitation, and the unit placement within a confinement area, gave it the potential to contaminate more fluid that what it could save.

Lazarus, Lloyd

2008-12-03T23:59:59.000Z

403

Role of the target orientation angle and orbital angular momentum in the evaporation residue production  

E-Print Network (OSTI)

The influence of the orientation angles of the target nucleus symmetry axis relative to the beam direction on the production of the evaporation residues is investigated for the $^{48}$Ca+$^{154}$Sm reaction as a function of the beam energy. At low energies ($E_{\\rm c.m.}orientation angles ($\\alpha_Torientation angles $\\alpha_T$ can contribute to the evaporation residue cross section $\\sigma_{ER}$ in the 10--100 mb range, and at $E_{c.m.}>$180 MeV $\\sigma_{ER}$ ranges around 0.1--10 mb because the fission barrier for a compound nucleus decreases by increasing its excitation energy and angular momentum.

Giovanni Fazio; Giorgio Giardina; Francis Hanappe; Giuseppe Mandaglio; Marina Manganaro; Akhtam I. Muminov; Avazbek K. Nasirov; Carmelo Sacca

2008-09-22T23:59:59.000Z

404

Establish feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys  

DOE Green Energy (OSTI)

Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some application.

Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

1987-01-01T23:59:59.000Z

405

Establish feasibility for providing passive cooling with solar updraft and evaporate downdraft chimneys  

DOE Green Energy (OSTI)

Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some applications.

Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

1987-01-01T23:59:59.000Z

406

Environmental sampling program for a solar evaporation pond for liquid radioactive wastes  

Science Conference Proceedings (OSTI)

Los Alamos Scientific Laboratory (LASL) is evaluating solar evaporation as a method for disposal of liquid radioactive wastes. This report describes a sampling program designed to monitor possible escape of radioactivity to the environment from a solar evaporation pond prototype constructed at LASL. Background radioactivity levels at the pond site were determined from soil and vegetation analyses before construction. When the pond is operative, the sampling program will qualitatively and quantitatively detect the transport of radioactivity to the soil, air, and vegetation in the vicinity. Possible correlation of meteorological data with sampling results is being investigated and measures to control export of radioactivity by biological vectors are being assessed.

Romero, R.; Gunderson, T.C.; Talley, A.D.

1980-04-01T23:59:59.000Z

407

Spectral Lags of Gamma-Ray Bursts from Primordial Black Hole (PBH) Evaporations  

E-Print Network (OSTI)

Primordial Black Holes (PBHs), which may have been created in the early Universe, are predicted to be detectable by their Hawking radiation. PBHs with an initial mass of 5.0 * 10^14 g should be expiring today with a burst of high energy particles. Evaporating PBHs in the solar neighborhood are candidate Gamma-Ray Bursts (GRBs) progenitors. We propose spectral lag, which is the temporal delay between the high energy photon pulse and the low energy photon pulse, as a possible method to detect PBH evaporation events with the Fermi Gamma-ray Space Telescope Observatory.

T. N. Ukwatta; J. H. MacGibbon; W. C. Parke; K. S. Dhuga; A. Eskandarian; N. Gehrels; L. Maximon; D. C. Morris

2009-01-05T23:59:59.000Z

408

ANALYSIS OF 2H-EVAPORATOR SCALE POT BOTTOM SAMPLE [HTF-13-11-28H  

SciTech Connect

Savannah River Remediation (SRR) is planning to remove a buildup of sodium aluminosilicate scale from the 2H-evaporator pot by loading and soaking the pot with heated 1.5 M nitric acid solution. Sampling and analysis of the scale material from the 2H evaporator has been performed so that the evaporator can be chemically cleaned beginning July of 2013. Historically, since the operation of the Defense Waste Processing Facility (DWPF), silicon in the DWPF recycle stream combines with aluminum in the typical tank farm supernate to form sodium aluminosilicate scale mineral deposits in the 2H-evaporator pot and gravity drain line. The 2H-evaporator scale samples analyzed by Savannah River National Laboratory (SRNL) came from the bottom cone sections of the 2H-evaporator pot. The sample holder from the 2Hevaporator wall was virtually empty and was not included in the analysis. It is worth noting that after the delivery of these 2H-evaporator scale samples to SRNL for the analyses, the plant customer determined that the 2H evaporator could be operated for additional period prior to requiring cleaning. Therefore, there was no need for expedited sample analysis as was presented in the Technical Task Request. However, a second set of 2H evaporator scale samples were expected in May of 2013, which would need expedited sample analysis. X-ray diffraction analysis (XRD) confirmed the bottom cone section sample from the 2Hevaporator pot consisted of nitrated cancrinite, (a crystalline sodium aluminosilicate solid), clarkeite and uranium oxide. There were also mercury compound XRD peaks which could not be matched and further X-ray fluorescence (XRF) analysis of the sample confirmed the existence of elemental mercury or mercuric oxide. On ?as received? basis, the scale contained an average of 7.09E+00 wt % total uranium (n = 3; st.dev. = 8.31E-01 wt %) with a U-235 enrichment of 5.80E-01 % (n = 3; st.dev. = 3.96E-02 %). The measured U-238 concentration was 7.05E+00 wt % (n=3, st. dev. = 8.25E-01 wt %). Analyses results for Pu-238 and Pu-239, and Pu-241 are 7.06E-05 ? 7.63E-06 wt %, 9.45E-04 ? 3.52E-05 wt %, and <2.24E-06 wt %, respectively. These results are provided so that SRR can calculate the equivalent uranium-235 concentrations for the NCSA. Because this 2H evaporator pot bottom scale sample contained a significant amount of elemental mercury (11.7 wt % average), it is recommended that analysis for mercury be included in future Technical Task Requests on 2H evaporator sample analysis at SRNL. Results confirm that the uranium contained in the scale remains depleted with respect to natural uranium. SRNL did not calculate an equivalent U-235 enrichment, which takes into account other fissionable isotopes U-233, Pu-239 and Pu-241.

Oji, L.

2013-07-15T23:59:59.000Z

409

Lignite Fuel Enhancement  

SciTech Connect

Pulverized coal power plants which fire lignites and other low-rank high-moisture coals generally operate with reduced efficiencies and increased stack emissions due to the impacts of high fuel moisture on stack heat loss and pulverizer and fan power. A process that uses plant waste heat sources to evaporate a portion of the fuel moisture from the lignite feedstock in a moving bed fluidized bed dryer (FBD) was developed in the U.S. by a team led by Great River Energy (GRE). The demonstration was conducted with Department of Energy (DOE) funding under DOE Award Number DE-FC26-04NT41763. The objectives of GRE's Lignite Fuel Enhancement project were to demonstrate reduction in lignite moisture content by using heat rejected from the power plant, apply technology at full scale at Coal Creek Station (CCS), and commercialize it. The Coal Creek Project has involved several stages, beginning with lignite drying tests in a laboratory-scale FBD at the Energy Research Center (ERC) and development of theoretical models for predicting dryer performance. Using results from these early stage research efforts, GRE built a 2 ton/hour pilot-scale dryer, and a 75 ton/hour prototype drying system at Coal Creek Station. Operated over a range of drying conditions, the results from the pilot-scale and prototype-scale dryers confirmed the performance of the basic dryer design concept and provided the knowledge base needed to scale the process up to commercial size. Phase 2 of the GRE's Lignite Fuel Enhancement project included design, construction and integration of a full-scale commercial coal drying system (four FBDs per unit) with Coal Creek Units 1 and 2 heat sources and coal handling system. Two series of controlled tests were conducted at Coal Creek Unit 1 with wet and dried lignite to determine effect of dried lignite on unit performance and emissions. Wet lignite was fired during the first, wet baseline, test series conducted in September 2009. The second test series was performed in March/April 2010 after commercial coal drying system was commissioned. Preliminary tests with dried coal were performed in March/April 2010. During the test Unit 2 was in outage and, therefore, test unit (Unit 1) was carrying entire station load and, also, supplying all auxiliary steam extractions. This resulted in higher station service, lower gross power output, and higher turbine cycle heat rate. Although, some of these effects could be corrected out, this would introduce uncertainty in calculated unit performance and effect of dried lignite on unit performance. Baseline tests with dried coal are planned for second half of 2010 when both units at Coal Creek will be in service to establish baseline performance with dried coal and determine effect of coal drying on unit performance. Application of GRE's coal drying technology will significantly enhance the value of lignite as a fuel in electrical power generation power plants. Although existing lignite power plants are designed to burn wet lignite, the reduction in moisture content will increase efficiency, reduce pollution and CO{sub 2} emissions, and improve plant economics. Furthermore, the efficiency of ultra supercritical units burning high-moisture coals will be improved significantly by using dried coal as a fuel. To date, Great River Energy has had 63 confidentiality agreements signed by vendors and suppliers of equipment and 15 utilities. GRE has had agreements signed from companies in Canada, Australia, China, India, Indonesia, and Europe.

Charles Bullinger; Nenad Sarunac

2010-03-31T23:59:59.000Z

410

Results from evaporation tests to support the MWTF heat removal system design  

Science Conference Proceedings (OSTI)

An experimental tests program was conducted to measure the evaporative heat removal from the surface of a tank of simulated waste. The results contained in this report constitute definition design data for the latest heat removal function of the MWTF primary ventilation system.

Crea, B.A.

1994-12-22T23:59:59.000Z

411

Pasquill’s Influence: On the Evaporation from Various Liquids into the Atmosphere  

Science Conference Proceedings (OSTI)

A theory of evaporation from a plane, free-liquid surface was first introduced by O. G. Sutton. However, in recognizing the shortcomings of Sutton’s theory, F. Pasquill proposed a generalized theory—that is, to modify Sutton’s theory by replacing ...

C. H. Huang

1997-08-01T23:59:59.000Z

412

CFD Simulation and Analysis of the Combined Evaporative Cooling and Radiant Ceiling Air-conditioning System  

E-Print Network (OSTI)

Due to such disadvantages as large air duct and high energy consumption of the current all- outdoor air evaporative cooling systems used in the dry region of Northwest China, as well as the superiority of the ceiling cooling system in improving thermal comfort and saving energy, a combined system is presented in this paper. It combines an evaporative cooling system with ceiling cooling, in which the evaporative cooling system handles the entire latent load and one part of the sensible loads, and the ceiling cooling system deals with the other part of sensible loads in the air-conditioned zone, so that the condensation on radiant panels and the insufficiency of cooling capacity can be avoided. The cooling water at 18? used in the cooling coils of ceiling cooling system can be ground water, tap water or the cooled water from cooling towers in the summer. This new air-conditioning system and existing all- outdoor air evaporative cooling system are applied to a project in the city of Lanzhou. Energy consumption analysis of the building is carried out using the energy consumption code. Velocity and temperature distribution in the air-conditioned zone is computed using CFD. According to the results, the energy consumption and indoor human thermal comfort of both systems are then compared. It is concluded that the new system occupies less building space, reduces energy consumption, improves indoor human thermal comfort and saves initial investment.

Xiang, H.; Yinming, L.; Junmei, W.

2006-01-01T23:59:59.000Z

413

The Effect of Manganese Additions on the Reactive Evaporation of Chromium in Ni-Cr Alloys  

DOE Green Energy (OSTI)

Chromium is used as an alloy addition in stainless steels and nickel-chromium alloys to form protective chromium oxide scales. Chromium oxide undergoes reactive evaporation in high temperature exposures in the presence of oxygen and/or water vapor. The deposition of gaseous chromium species onto solid oxide fuel cell electrodes can reduce the efficiency of the fuel cell. Manganese additions to the alloy can reduce the activity of chromium in the oxide, either from solid solution replacement of chromium with manganese (at low levels of manganese) or from the formation of manganese-chromium spinels (at high levels of manganese). This reduction in chromium activity leads to a predicted reduction in chromium evaporation by as much as a factor of 35 at 800 C and 55 at 700 C. The results of evaporation loss measurements on nickel-chromium-manganese alloys are compared with the predicted reduction. Quantifying the effects of manganese additions on chromium evaporation should aid alloy development of metallic interconnects and balance-of-plant alloys.

Holcomb, Gordon R.; Alman, David E.

2004-10-20T23:59:59.000Z

414

Evaporation-Wind Feedback and Low-Frequency Variability in the Tropical Atmosphere  

Science Conference Proceedings (OSTI)

A mechanism by which feedback between zonal wind perturbations and evaporation can create unstable, low-frequency modes in a simple two-layer model of the tropical troposphere is presented. The modes resemble the 30–50 day oscillation. A series ...

J. David Neelin; Isaac M. Held; Kerry H. Cook

1987-08-01T23:59:59.000Z

415

The evaporation rate, free energy, and entropy of amorphous water Robin J. Speedy  

E-Print Network (OSTI)

The evaporation rate, free energy, and entropy of amorphous water at 150 K Robin J. Speedy can be interpreted as giving a measure of their free energy difference, i a G 150 K 1100 100 J of amorphous water (a) and ice (i) near 150 K and suppose that their ratio gives a measure of their free energy

416

Under consideration for publication in J. Fluid Mech. 1 Evaporation and combustion  

E-Print Network (OSTI)

Under consideration for publication in J. Fluid Mech. 1 Evaporation and combustion of thin films the tendency to destabilize the planar interface, combustion acts to reduce this effect. In particular, when the heat release by combustion is substantial, all disturbances are obliterated, the film remains nearly

417

The Impact of Sea Spray Evaporation in a Numerical Weather Prediction Model  

Science Conference Proceedings (OSTI)

Strong winds above the sea lead to large amounts of spray in the lowest part of the boundary layer. Through their evaporation, spray droplets influence the exchange of sensible and latent heat between sea and air. In this study, the impact of ...

Jan F. Meirink; Vladimir K. Makin

2001-12-01T23:59:59.000Z

418

Heat-transfer characteristics of climbing film evaporation in a vertical tube  

SciTech Connect

Heat-transfer characteristics of climbing film evaporation were experimentally investigated on a vertical climbing film evaporator heated by tube-outside hot water. The experimental setup was designed for determining the effect of the height of feed water inside a vertical tube and the range of temperature difference on local heat transfer coefficient inside a vertical tube (h{sub i}). In this setup, the height of feed water was successfully controlled and the polypropylene shell effectively impedes the heat loss to the ground. The results indicated that a reduction in the height of feed water contributed to a significant increase in h{sub i} if no dry patches around the wall of the heated tube appeared inside the tube. The height ratio of feed water R{sub h} = 0.3 was proposed as the optimal one as dry patches destroyed the continuous climbing film when R{sub h} is under 0.3. It was found that the minimum temperature difference driving climbing film evaporation is suggested as 5 C due to a sharp reduction in h{sub i} for temperature difference below 5 C. The experiment also showed that h{sub i} increased with an increase in temperature difference, which proved the superiority of climbing film evaporation in utilizing low-grade surplus heating source due to its wide range of driving temperature difference. The experimental results were compared with the previous literature and demonstrated a satisfactory agreement. (author)

Yang, Luopeng; Chen, Xue; Shen, Shengqiang [Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, School of Energy and Power Engineering, Dalian University of Technology, Dalian 116024 (China)

2010-09-15T23:59:59.000Z

419

Thermally Evaporated Iron (Oxide) on an Alumina Barrier Layer, by XPS  

SciTech Connect

We report the XPS characterization of a thermally evaporated iron thin film (6 nm) deposited on an Si/SiO_2/Al_2O_3 substrate using Al Ka X-rays. An XPS survey spectrum, narrow Fe 2p scan, narrow O 1s, and valence band scan are shown.

Madaan, Nitesh; Kanyal, Supriya S.; Jensen, David S.; Vail, Michael A.; Dadson, Andrew; Engelhard, Mark H.; Linford, Matthew R.

2013-09-06T23:59:59.000Z

420

Direct Numerical Simulation of Evaporative Cooling at the Lateral Boundary of Shallow Cumulus Clouds  

Science Conference Proceedings (OSTI)

This study investigates the dynamics of the subsiding shell at the lateral boundary of cumulus clouds, focusing on the role of evaporative cooling. Since the size of this shell is well below what large-eddy simulations can resolve, the authors ...

Dick Abma; Thijs Heus; Juan Pedro Mellado

2013-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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 Studies of Droplet Evaporation Kinetics: Validation of Models for Binary and Ternary Aqueous Solutions  

Science Conference Proceedings (OSTI)

Experiments were conducted with an electrodynamic levitation system to study the kinetics of droplet evaporation under chemically rich conditions. Single solution droplets of known composition (HNO3/H2O or H2SO4/HNO3/H2O) were introduced into an ...

Huiwen Xue; Alfred M. Moyle; Nathan Magee; Jerry Y. Harrington; Dennis Lamb

2005-12-01T23:59:59.000Z

422

242-16H 2H EVAPORATOR POT SAMPLING FINAL REPORT  

Science Conference Proceedings (OSTI)

Due to the materials that are processed through 2H Evaporator, scale is constantly being deposited on the surfaces of the evaporator pot. In order to meet the requirements of the Nuclear Criticality Safety Analysis/Evaluation (NCSA/NCSE) for 2H Evaporator, inspections of the pot are performed to determine the extent of scaling. Once the volume of scale reaches a certain threshold, the pot must be chemically cleaned to remove the scale. Prior to cleaning the pot, samples of the scale are obtained to determine the concentration of uranium and plutonium and also to provide information to assist with pot cleaning. Savannah River National Laboratory (SRNL) was requested by Liquid Waste Organization (LWO) Engineering to obtain these samples from two locations within the evaporator. Past experience has proven the difficulty of successfully obtaining solids samples from the 2H Evaporator pot. To mitigate this risk, a total of four samplers were designed and fabricated to ensure that two samples could be obtained. Samples had previously been obtained from the cone surface directly below the vertical access riser using a custom scraping tool. This tool was fabricated and deployed successfully. A second scraper was designed to obtain sample from the nearby vertical thermowell and a third scraper was designed to obtain sample from the vertical pot wall. The newly developed scrapers both employed a pneumatically actuated elbow. The scrapers were designed to be easily attached/removed from the elbow assembly. These tools were fabricated and deployed successfully. A fourth tool was designed to obtain sample from the opposite side of the pot under the tube bundle. This tool was fabricated and tested, but the additional modifications required to make the tool field-ready could not be complete in time to meet the aggressive deployment schedule. Two samples were obtained near the pot entry location, one from the pot wall and the other from the evaporator feed pipe. Since a third sampler was available and all of the radiological controls were in place, the decision was made to obtain a third sample. The third sampler dropped directly below the riser to obtain a scrape sample from the evaporator cone. Samples were obtained from all of these locations in sufficient quantities to perform the required analysis.

Krementz, D; William Cheng, W

2008-06-11T23:59:59.000Z

423

Effect of adding flash tank on the evaporator's thermal load of the combined ejector-absorption cooling system  

Science Conference Proceedings (OSTI)

A modified combined absorption-ejector cooling system using aqua-ammonia (NH3-H2O) refrigerant has been investigated. Removable flash tank was added between the condenser and the evaporator. The modified cycle brings the advantage of improving in the ... Keywords: absorption system, combined absorption cooling system, ejectors, evaporators

Ranj Sirwan; Yusoff Ali; A. Zaharim; K. Sopian

2011-10-01T23:59:59.000Z

424

Original papers: Aerodynamic analysis and CFD simulation of several cellulose evaporative cooling pads used in Mediterranean greenhouses  

Science Conference Proceedings (OSTI)

The present work makes an aerodynamic analysis and computational fluid dynamics (CFD) simulation of the four commercial models of corrugated cellulose evaporative cooling pads that are most widely used in Mediterranean greenhouses. The geometric characteristics ... Keywords: Aerodynamic analysis, CFD, Evaporative cooling, Fan and pad, Greenhouse, Pressure drop

A. Franco; D. L. Valera; A. Peña; A. M. Pérez

2011-05-01T23:59:59.000Z

425

VELOCITY CHARACTERISTICS OF EVAPORATED PLASMA USING HINODE/EUV IMAGING SPECTROMETER  

Science Conference Proceedings (OSTI)

This paper presents a detailed study of chromospheric evaporation using the EUV Imaging Spectrometer (EIS) onboard Hinode in conjunction with hard X-ray (HXR) observations from Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI). The advanced capabilities of EIS were used to measure Doppler shifts in 15 emission lines covering the temperature range T = 0.05-16 MK during the impulsive phase of a C-class flare on 2007 December 14. Blueshifts indicative of the evaporated material were observed in six emission lines from Fe XIV-XXIV (2-16 MK). Upflow velocity (v{sub up}) was found to scale with temperature as v{sub up} (km s{sup -1}) {approx} 8-18T(MK). Although the hottest emission lines, Fe XXIII and Fe XXIV, exhibited upflows of >200 km s{sup -1}, their line profiles were found to be dominated by a stationary component in contrast to the predictions of the standard flare model. Emission from O VI-Fe XIII lines (0.5-1.5 MK) was found to be redshifted by v{sub down} (km s{sup -1}) {approx} 60-17T (MK) and was interpreted as the downward-moving 'plug' characteristic of explosive evaporation. These downflows occur at temperatures significantly higher than previously expected. Both upflows and downflows were spatially and temporally correlated with HXR emission observed by RHESSI that provided the properties of the electron beam deemed to be the driver of the evaporation. The energy flux of the electron beam was found to be {approx}>5 x 10{sup 10} erg cm{sup -2} s{sup -1}, consistent with the value required to drive explosive chromospheric evaporation from hydrodynamic simulations.

Milligan, Ryan O.; Dennis, Brian R. [Solar Physics Laboratory (Code 671), Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2009-07-10T23:59:59.000Z

426

Desiccant-Based Combined Systems  

E-Print Network (OSTI)

and designers to consider HAVC system designs that can meet ASHRAE 62 and control space humidity. Previously

Oak Ridge National Laboratory

427

Does Evaporation over the Arabian Sea Play a Crucial Role in Moisture Transport across the West Coast of India during an Active Monsoon Period?  

Science Conference Proceedings (OSTI)

In the present study interannual variability of the contributions of evaporation and moisture flux from the Southern Hemisphere towards the moisture transport across the west coast of India is examined. The mean rates of evaporation and ...

Y. Sadhuram; M. R. Ramesh Kumar

1988-02-01T23:59:59.000Z

428

Design of a Solar Thermal Powered Cooling System.  

E-Print Network (OSTI)

??Abstract The main objective of the thesis was to design a mechanical structure for a desiccant evaporative cooling, to apply solar thermal powered air conditioning… (more)

Hurri, Olli

2011-01-01T23:59:59.000Z

429

An evaporation-based model of thermal neutron induced ternary fission of plutonium  

E-Print Network (OSTI)

Ternary fission probabilities for thermal neutron induced fission of plutonium are analyzed within the framework of an evaporation-based model where the complexity of time-varying potentials, associated with the neck collapse, are included in a simplistic fashion. If the nuclear temperature at scission and the fission-neck-collapse time are assumed to be ~1.2 MeV and ~10^-22 s, respectively, then calculated relative probabilities of ternary-fission light-charged-particle emission follow the trends seen in the experimental data. The ability of this model to reproduce ternary fission probabilities spanning seven orders of magnitude for a wide range of light-particle charges and masses implies that ternary fission is caused by the coupling of an evaporation-like process with the rapid re-arrangement of the nuclear fluid following scission.

J. P. Lestone

2007-03-10T23:59:59.000Z

430

Evaporation-Induced Buckling and Fission of Microscale Droplet Interface Bilayers  

Science Conference Proceedings (OSTI)

Droplet interface bilayers (DIBs) are a robust platform for studying synthetic cellular membranes; however, to date no DIBs have been produced at cellular length scales. Here, we create microscale droplet interface bilayers ( DIBs) at the interface between aqueous femtoliter-volume droplets within an oil-filled microfluidic channel. The uniquely large area-to-volume ratio of the droplets results in strong evaporation effects, causing the system to transition through three distinct regimes. First, the two adjacent droplets shrink into the shape of a single spherical droplet, where an augmented lipid bilayer partitions two hemi-spherical volumes. In the second regime, the combined effects of the shrinking monolayers and growing bilayer force the confined bilayer to buckle to conserve its mass. Finally, at a bending moment corresponding to a critical shear stress, the buckling bilayer fissions a vesicle to regulate its shape and stress. The DIBs produced here enable evaporation-induced bilayer dynamics reminiscent of endo- and exocytosis in cells.

Boreyko, Jonathan B [ORNL; Mruetusatorn, Prachya [ORNL; Sarles, Stephen A [ORNL; Retterer, Scott T [ORNL; Collier, Pat [ORNL

2013-01-01T23:59:59.000Z

431

Green Data Center Cooling: Achieving 90% Reduction: Airside Economization and Unique Indirect Evaporative Cooling  

Science Conference Proceedings (OSTI)

The Green Data Center Project was a successful effort to significantly reduce the energy use of the National Snow and Ice Data Center (NSIDC). Through a full retrofit of a traditional air conditioning system, the cooling energy required to meet the data center's constant load has been reduced by over 70% for summer months and over 90% for cooler winter months. This significant change is achievable through the use of airside economization and a new indirect evaporative cooling system. One of the goals of this project was to create awareness of simple and effective energy reduction strategies for data centers. This project's geographic location allowed maximizing the positive effects of airside economization and indirect evaporative cooling, but these strategies may also be relevant for many other sites and data centers in the U.S.

Weerts, B. A.; Gallaher, D.; Weaver, R.; Van Geet, O.

2012-01-01T23:59:59.000Z

432

Concentration of Melton Valley Storage Tank surrogates with a wiped film evaporator  

SciTech Connect

This report describes experiments to determine whether a wiped film evaporator (WFE) might be used to concentrate low-level liquid radioactive waste (LLLW). Solutions used in these studies were surrogates that contain no radionuclides. The compositions of the surrogates were based on one of Oak Ridge National Laboratory`s (ORNL`s) Melton Valley Storage Tanks (MVSTs). It was found that a WFE could be used to concentrate LLLW to varying degrees by manipulating various parameters. The parameters studied were rotor speed, process fluid feed temperature and feed rate, and evaporator temperature. Product consistency varied from an unsaturated liquid to a dry powder. Volume reductions up to 68% were achieved. System decontamination factors were consistently in the range of 10{sup 4}.

Boring, M.D.; Farr, L.L.; Fowler, V.L.; Hewitt, J.D.

1994-08-01T23:59:59.000Z

433

Co-Evaporated Cu2ZnSnSe4 Films and Devices  

DOE Green Energy (OSTI)

The use of vacuum co-evaporation to produce Cu2ZnSnSe4 photovoltaic devices with 9.15% total-area efficiency is described. These new results suggest that the early success of the atmospheric techniques for kesterite photovoltaics may be related to the ease with which one can control film composition and volatile phases, rather than a fundamental benefit of atmospheric conditions for film properties. The co-evaporation growth recipe is documented, as is the motivation for various features of the recipe. Characteristics of the resulting kesterite films and devices are shown in scanning electron micrographs, including photoluminescence, current-voltage, and quantum efficiency. Current-voltage curves demonstrate low series resistance without the light-dark cross-over seen in many devices in the literature. Band gap indicated by quantum efficiency and photoluminescence is roughly consistent with that expected from first principles calculation.

Repins, I.; Beall, C.; Vora, N.; DeHart, C.; Kuciauskas, D.; Dippo, P.; To, B.; Mann, J.; Hsu, W. C.; Goodrich, A.; Noufi, R.

2012-06-01T23:59:59.000Z

434

Emerging Technologies for Efficient Data Centers: Uninterruptible Power Supply Eco Mode, Liquid Cooling, and Evaporative Cooling  

Science Conference Proceedings (OSTI)

This report summarizes research in emerging technologies that improve data center energy efficiency, including evaporative cooling, liquid cooling, and high-efficiency eco mode operation of the uninterruptible power supply. The report describes the efficiency gains of these technologies and their impact on total data center energy use. It also identifies market barriers for each technology and potential next steps to promote adoption of these efficient technologies.

2013-12-09T23:59:59.000Z

435

A feasibility study of internal evaporative cooling for proton exchange membrane fuel cells  

E-Print Network (OSTI)

An investigation was conducted to determine the feasibility of using the technique of ultrasonic nebulization of water into the anode gas stream for evaporative cooling of a Proton Exchange Membrane (PEM) fuel cell. The basic concept of this form of internal evaporative cooling of the PEM fuel cell is to introduce finely atomized liquid water into the anode gas stream, so that the finely atomized liquid water adsorbs onto the anode and then moves to the cathode via electro-osmotic drag, where this water then evaporates into the relatively dry cathode gas stream, carrying with it the waste thermal energy generated within the fuel cell. The thermal and electrical performance of a 50 cm2 PEM fuel cell utilizing this technique was compared to the performance obtained with conventional water management. Both techniques were compared over a range of humidification chamber temperatures for both the anode and cathode gas streams so as to determine the robustness of the proposed method. The proposed method produced only meager levels of evaporative cooling (at best 2 watts, for which a minimum of 30 watts was required for adequate cooling), but the average cell voltage increased considerably (as much as a 10% gain), and the technique increased the fault tolerance of the fuel cell (the Nafion� membrane did not dry out even if cell temperature went well in excess of 70° C despite both anode and cathode humidification temperatures of 55° C). An interesting phenomena was also observed wherein the fuel cell voltage oscillated regularly with a period of tens of seconds, and that the amplitude of this oscillation corresponded inversely with the level of humidification received by the fuel cell.

Snyder, Loren E

2004-12-01T23:59:59.000Z

436

Determination of uranium distribution in the evaporation of simulated Savannah River Site waste  

SciTech Connect

The results of an experimental program addressing the distribution of uranium in saltcake and supernate for two Savannah River Site waste compositions are presented. Successive batch evaporations were performed on simulated H-Area Modified Purex low-heat and post-aluminum dissolution wastes spiked with depleted uranium. Waste compositions and physical data were obtained for supernate and saltcake samples. For the H-Area Modified Purex low-heat waste, the product saltcake contained 42% of the total uranium from the original evaporator feed solution. However, precipitated solids only accounted for 10% of the original uranium mass; the interstitial liquid within the saltcake matrix contained the remainder of the uranium. In the case of the simulated post-aluminum dissolution waste; the product saltcake contained 68% of the total uranium from the original evaporator feed solution. Precipitated solids accounted for 52% of the original uranium mass; again, the interstitial liquid within the saltcake matrix contained the remainder of the uranium. An understanding of the distribution of uranium between supernatant liquid, saltcake, and sludge is required to develop a material balance for waste processing operations. This information is necessary to address nuclear criticality safety concerns.

Barnes, M.J.; Chandler, G.T.

1995-01-01T23:59:59.000Z

437

NNSA orders security enhancements  

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

orders security enhancements NNSA orders security enhancements Because of this government order, until further notice all vehicles entering government property will be required to...

438

Modification of the Thermodynamic Structure of the Lower Troposphere by the Evaporation of Precipitation: A GEWEX Cloud System Study  

Science Conference Proceedings (OSTI)

The importance of subcloud evaporation to the thermodynamics and movement of cold fronts is investigated through inclusion of an explicit cloud scheme within a 30-km resolution limited-area model. Two cases are examined: 18 November 1984 and 26 ...

J. J. Katzfey; B. F. Ryan

1997-07-01T23:59:59.000Z

439

Modeling the Effect of Land Surface Evaporation Variability on Precipitation Variability. Part II: Time- and Space-Scale structure  

Science Conference Proceedings (OSTI)

This is the second of a two-part article investigating the impact of variations of land surface evaporability on the interannual variability of precipitation. The first goal of this part is to analyze the relationship between the atmospheric ...

Oreste Reale; Paul Dirmeyer; Adam Schlosser

2002-08-01T23:59:59.000Z

440

Establishing feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys. Progress report, March 1985--September 1985  

DOE Green Energy (OSTI)

The solar updraft and a natural evaporative downdraft tower built onto an existing residence structure and a greenhouse were completed and operating. Performance data for the hottest days of June, July, and August, 1985 are included. (MHR)

Cunningham, W.A.; Migon, G.V.

1985-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "desiccant enhanced evaporative" 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

A Resistance Representation of Schemes for Evaporation from Bare and Partly Plant-covered Surfaces for Use in Atmospheric Models  

Science Conference Proceedings (OSTI)

In the parameterization of land surface processes, attention must be devoted to surface evaporation, one of the main processes in the air-land energy exchange. One of the most used approaches is the resistance representation which requires the ...

Dragutin T. Mihailovi?; Roger A. Pielke; Borivoj Rajkovi?; Tsengdar J. Lee; Milan Jefti?

1993-06-01T23:59:59.000Z

442

Does the Influence of Oblate-Like Distortions in Larger Raindrops Make a Difference in Collection and Evaporation Parameterizations?  

Science Conference Proceedings (OSTI)

This note documents the results of more exact parameterizations for continuous-collection growth and evaporation against simpler traditional ones. Although the main focus is on improving research models, the research results also apply to high-...

Jerry M. Straka; Matthew S. Gilmore

2006-11-01T23:59:59.000Z

443

Spatially resolved temperature and heat flux measurements for slow evaporating droplets heated by a microfabricated heater array  

E-Print Network (OSTI)

The evaporation phenomenon of a liquid droplet was investigated by using microfabricated heaters. All 32 microheaters were designed to have the same resistance. Gold microheaters worked both as temperature indicators and as heaters. The first experiment was performed under a constant voltage mode to investigate the temperature and heat flux variation of the heated surface by the evaporating droplet. The second experiment was performed under constant temperature mode to investigate the spatial and temporal heat flux variation of the constant temperature heater surface by the evaporating droplet heater. Droplet evaporation was recorded with a CCD camera. Experimental data showed temperature and heat flux variations inside and outside of the droplet with respect to time and radial position from the center of the droplet by tomographic deconvolution.

Paik, Sokwon

444

Preliminary evaluation of the performance, water use, and current application trends of evaporative coolers in California climates  

SciTech Connect

This paper describes the latest results of an ongoing analysis investigating the potential for evaporative cooling as an energy-efficient alternative to standard air-conditioning in California residences. In particular, the study uses detailed numerical models of evaporative coolers linked with the DOE-2 building energy simulation program to study the issues of indoor comfort, energy and peak demand savings with and without supplemental air-conditioning and consumptive water use. In addition, limited surveys are used to assess the current market availability of evaporative cooling in California, typical contractor practices and costs, and general acceptance of the technology among engineers, contractors, and manufacturers. The results show that evaporative coolers can provide significant energy and peak demand savings in California residences, but the impact of the increased indoor humidity on human comfort remains an unanswered question that requires further research and clarification. Evaluated against ASHRAE comfort standards developed primarily for air-conditioning both direct and two-stage evaporative coolers would not maintain comfort at peak cooling conditions due to excessive humidity. However, using bioclimatic charts that place human comfort at the 80% relative humidity line, the study suggests that direct evaporative coolers will work in mild coastal climates, while two-stage models should provide adequate comfort in Title 24 houses throughout California, except in the Imperial Valley. The study also shows that evaporative coolers will increase household water consumption by less than 6% on an annual basis, and as much as 23% during peak cooling months, and that the increases in water cost are minimal compared to the electricity savings. Lastly, a survey of engineers and contractors revealed generally positive experiences with evaporative coolers, with operational cost savings, improved comfort, unproved air quality as the primary benefits in their use.

Huang, Y.J.; Hanford, J.W.; Wu, H.F.

1992-09-01T23:59:59.000Z

445

Project C-018H, 242-A Evaporator/PUREX Plant Process Condensate Treatment Facility, functional design criteria. Revision 3  

Science Conference Proceedings (OSTI)

This document provides the Functional Design Criteria (FDC) for Project C-018H, the 242-A Evaporator and Plutonium-Uranium Extraction (PUREX) Plant Condensate Treatment Facility (Also referred to as the 200 Area Effluent Treatment Facility [ETF]). The project will provide the facilities to treat and dispose of the 242-A Evaporator process condensate (PC), the Plutonium-Uranium Extraction (PUREX) Plant process condensate (PDD), and the PUREX Plant ammonia scrubber distillate (ASD).

Sullivan, N.

1995-05-02T23:59:59.000Z

446

APPLICATION OF A THIN FILM EVAPORATOR SYSTEM FOR MANAGEMENT OF LIQUID HIGH-LEVEL WASTES AT HANFORD  

Science Conference Proceedings (OSTI)

A modular, transportable evaporator system, using thin film evaporative technology, is planned for deployment at the Hanford radioactive waste storage tank complex. This technology, herein referred to as a wiped film evaporator (WFE), will be located at grade level above an underground storage tank to receive pumped liquids, concentrate the liquid stream from 1.1 specific gravity to approximately 1.4 and then return the concentrated solution back into the tank. Water is removed by evaporation at an internal heated drum surface exposed to high vacuum. The condensed water stream will be shipped to the site effluent treatment facility for final disposal. This operation provides significant risk mitigation to failure of the aging 242-A Evaporator facility; the only operating evaporative system at Hanford maximizing waste storage. This technology is being implemented through a development and deployment project by the tank farm operating contractor, Washington River Protection Solutions (WRPS), for the Office of River Protection/Department of Energy (ORP/DOE), through Columbia Energy & Environmental Services, Inc. (Columbia Energy). The project will finalize technology maturity and install a system at one of the double-shell tank farms. This paper discusses results of pre-project pilot-scale testing by Columbia Energy and ongoing technology maturation development scope through fiscal year 2012, including planned additional pilot-scale and full-scale simulant testing and operation with actual radioactive tank waste.

TEDESCHI AR; WILSON RA

2010-01-14T23:59:59.000Z

447

OTEC performance tests of the Union Carbide flooded-bundle evaporator  

DOE Green Energy (OSTI)

Results of performance tests conducted on a Union Carbide flooded-bundle evaporator with High Flux titanium tubes are reported. At design operating conditions (a heat duty of 3.2 million Btu/hr, an inlet water temperature of 80/sup 0/F, and a water flow rate of 3200 gpm) the steady-state value of the overall heat transfer coefficient (U/sub 0/) was found to be 785 Btu/hr ft/sup 2/ /sup 0/F, and the ammonia-side and water-side heat transfer coefficients were 4800 and 1400 Btu/hr ft/sup 2/ /sup 0/F, respectively. The water-side pressure drop was 2.7 psi. Variations in heat duty (+-25%) and liquid ammonia feed temperature (over the range of 48 to 64/sup 0/F) did not affect thermal performance significantly. On the other hand, U/sub 0/ was reduced appreciably by operational shutdowns during which nonboiling ammonia remained in contact with the High Flux surface for periods of 30 minutes or more. During a one-hour shutdown the value of U/sub 0/ decreased to 690 Btu/hr ft/sup 2/ /sup 0/F, and values as low as 600 Btu/hr ft/sup 2/ /sup 0/F were reached for longer shutdowns. Such contact appears to deactivate some of the nucleate boiling sites, thus reducing the heat transfer coefficient. Although operation of the evaporator under boiling conditions reverses this effect, reactivation takes place much more slowly than deactivation. Procedures for avoiding this problem in the operation of the High Flux flooded-bundle evaporator are given.

Lewis, L G; Sather, N F

1978-12-01T23:59:59.000Z

448

Abstract - Enhancing Trust by Enhancing the Audit Process  

Science Conference Proceedings (OSTI)

... including network security requirements Topic: Enhancing Trust by Enhancing the Audit Process Authors: Kerstin Schönherr ...

2013-03-12T23:59:59.000Z

449

Self-organized Archimedean Spiral Pattern: Regular Bundling of Fullerene through Solvent Evaporation  

E-Print Network (OSTI)

We report the spontaneous generation of an Archimedean spiral pattern of fullerene via the evaporation of solvent. The self-organized spiral pattern exhibited equi-spacing on the order of micrometer between neighboring stripes. The characteristics of the spirals, such as the spacing between stripes, the number of stripes and the band width of stripes, could be controlled by tuning the thickness of the liquid bridge and the concentration of solution. The mechanism of pattern formation is interpreted in terms of a specific traveling wave on the liquid-solid interface accompanied by a stick-slip process of the contact line.

Yong-Jun Chen; Kosuke Suzuki; Hitoshi Mahara; Kenichi Yoshikawa; Tomohiko Yamaguchi

2013-03-16T23:59:59.000Z

450

Literature survey on vertical tube evaporators (VTE's). Part I. Bibliographical entries  

DOE Green Energy (OSTI)

A bibliography of the literature pertinent to vertical tube heat exchangers for OTEC application has been prepared. More than 200 references from different sources (journals, books, companies and government reports) on heat exchanger design, operation and performance have been identified and surveyed for a two part report on the state-of-the-art of vertical tube evaporators. This bibliography represents Part I. Each bibliographical entry has been coded to facilitate references to particular articles in the narrative account of the survey represented in Part II.

Rothfus, R.R.; Neuman, C.P.; Lavi, G.H.; Farthing, G.A. Jr.; Prengaman, R.

1977-07-01T23:59:59.000Z

451

Blue Emission Peak of GeO{sub 2} Particles Grown Using Thermal Evaporation  

Science Conference Proceedings (OSTI)

In this paper we report a simple thermal evaporation technique (horizontal tube furnace) to grow large quantities of GeO{sub 2} particles with diameters ranging from tens of nanometer to 500 nm on n-type (100) Si substrate free of catalyst. The particles were grown at temperature about 1000 degree sign C for 2 hrs and characterized by scanning electron microscopy (SEM), X-Ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and photoluminescence (PL) spectroscopy. The photoluminescence spectrum reveals several emission peaks around 400 nm at room temperature. Raman measurement also measured at room temperature for this GeO{sub 2} particles.

Sulieman, Kamal Mahir [School of Physics, Universiti Sains Malaysia (USM), 11800 Minden, Penang (Malaysia); Physics Department, Alzaiem Alazhary University, 1432-Khartoum (Sudan); Jumidali, M. M. [School of Physics, Universiti Sains Malaysia (USM), 11800 Minden, Penang (Malaysia); Faculty of Applied Science, Universiti Teknologi MARA, 13500 Penang (Malaysia); Hashim, M. R. [School of Physics, Universiti Sains Malaysia (USM), 11800 Minden, Penang (Malaysia)

2010-07-07T23:59:59.000Z

452

Sodium waste technology: A summary report. [Melt-drain-evaporation-calcination (MEDEC)  

SciTech Connect

The Sodium Waste Technology (SWT) Program was established to resolve long-standing issues regarding disposal of sodium-bearing waste and equipment. Comprehensive SWT research programs investigated a variety of approaches for either removing sodium from sodium-bearing items, or disposal of items containing sodium residuals. The most successful of these programs was the design, test, and the production operation of the Sodium Process Demonstration Facility at ANL-W. The technology used was a series of melt-drain-evaporate operations to remove nonradioactive sodium from sodium-bearing items and then converting the sodium to storable compounds.

Abrams, C.S.; Witbeck, L.C.

1987-01-01T23:59:59.000Z

453

Giant Magnetoresistance In Ni/Cu Multilayers Fabricated By Electron-Beam Evaporation  

Science Conference Proceedings (OSTI)

Electron beam evaporation technique has been used to deposit the multilayers of Ni-Cu, represented by Si[BL{sub t}/[Ni(t{sub FM})/Cu(t{sub NM})]xn] where Si is used as a substrate and BL is buffer layer, n is the number of bilayers, t, t{sub FM} and t{sub NM} are thicknesses of buffer layer, ferromagnetic (Ni) and nonmagnetic (Cu) layers, respectively. We characterize the multilayers using M-H curves, magnetoresistance measurement (at room temperature)

Vikram, V.; Rahman, Md. Rizwanur; Katiyar, Monica [Department of Materials and Metallurgical Engineering Indian Institute of Technology Kanpur, Uttar Pradesh, 208016 (India)

2008-04-24T23:59:59.000Z

454

Establishing feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys  

DOE Green Energy (OSTI)

At the present time all experimental towers (chimneys) are completed and operating. This consists of both a solar updraft and a natural-evaporative downdraft tower retrofitted to an existing residence structure and a greenhouse. The residential, experimental, natural-draft cooling system was completed in May, 1985, and five months of summer data on a Hewlet Packard 85 data acquisition computer with a digital voltmeter were acquired. The cooling tower and solar chimney on the experimental greenhouse became operational in September of 1985. A conceptual drawing of both the greenhouse and the residence natural-draft towers is included in the appendix along with the September 85 progress report.

Cunningham, W.A.; Mignon, G.V.

1986-01-01T23:59:59.000Z

455

Sensitivity of the FERMI Detectors to Gamma-Ray Bursts from Evaporating Primordial Black Holes (PBHs)  

E-Print Network (OSTI)

Primordial Black Holes (PBHs), which may have been created in the early Universe, are predicted to be detectable by their Hawking radiation. The Fermi Gamma-ray Space Telescope observatory offers increased sensitivity to the gamma-ray bursts produced by PBHs with an initial mass of $\\sim 5\\times 10^{14}$ g expiring today. PBHs are candidate progenitors of unidentified Gamma-Ray Bursts (GRBs) that lack X-ray afterglow. We propose spectral lag, which is the temporal delay between the high and low energy pulses, as an efficient method to identify PBH evaporation events with the Fermi Large Area Telescope (LAT).

T. N. Ukwatta; Jane H. MacGibbon; W. C. Parke; K. S. Dhuga; S. Rhodes; A. Eskandarian; N. Gehrels; L. Maximon; D. C. Morris

2010-03-23T23:59:59.000Z

456

OTEC performance tests of the Carnegie-Mellon University vertical fluted-tube evaporator  

DOE Green Energy (OSTI)

Performance tests were conducted with the Carnegie-Mellon University (C-MU) vertical fluted-tube evaporator. Under nominal operating conditions (3200 gpm water flow, 3.2 million Btu/hr heat duty, and 100 gpm ammonia feed rate), the overall heat transfer coefficient (U/sub 0/) was 825 Btu/hr ft/sup 2/ /sup 0/F and the ammonia-side and water-side heat transfer coefficients were 1800 and 2610 Btu/hr ft/sup 2/ /sup 0/F, respectively. The water-side pressure drop was 3.2 psi. Tests were conducted at heat duties ranging from 2.4 million to 4.0 million Btu/hr and ammonia feed rates from 30 to 110 gpm. Over these ranges, U/sub 0/ increased with ammonia feed rate and decreased with heat duty. For all runs the quality of the ammonia vapor leaving the evaporator exceeded 99.9%. The measured U/sub 0/ values were very stable and repeatable for any continuous run at fixed operating conditions; however, they were not always repeatable following operating state changes or shutdown of the ammonia feed. These repeatability problems were attributed to variations in tube wetting and to the poor design of the ammonia applicator. Test results suggested that to ensure sufficient wetting and good thermal performance, the system should be started with a high ammonia feed rate and then cut back to the desired operating value.

Lorenz, J J; Yung, D T; Hillis, D L; Sather, N F

1979-07-01T23:59:59.000Z

457

One-Step Growth of Ge doped ZnO Tubes by Thermal Evaporation  

Science Conference Proceedings (OSTI)

In this paper we report a simple thermal evaporation technique (horizontal tube furnace) to grow the bulk-quantity of germanium (Ge) doped zinc oxide (ZnO) tubes on the Si substrate by using one-step thermal evaporation of a mixed powder of Ge and ZnO. The microstructure and optical properties of the Ge doped ZnO tubes have been investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction, photoluminescence (PL) spectrometer and Raman spectrometer. The investigation of structural properties indicated that the structures consist of bulk quantities of cylindrical rod and tube with diameter around 1micron. EDX reveals that the tube structures have Ge, Zn and O{sub 2} compositions and XRD analysis indicated the product is mainly composed of Ge, zinc germanium oxide (Zn{sub 2}GeO{sub 4}) and small proportion of ZnO. Room temperature photoluminescence (PL) spectrum shows broad emission peaks around 400 nm, opening up a route to potential applications in future optoelectronic devices. Raman measurement also measured at room temperature for these tubes.

Jumidali, M. M. [School of Physics, Universiti Sains Malaysia (USM), 11800 Minden, Penang (Malaysia); Faculty of Applied Science, Universiti Teknologi MARA, 13500 Penang (Malaysia); Hashim, M. R. [School of Physics, Universiti Sains Malaysia (USM), 11800 Minden, Penang (Malaysia); Sulieman, K. M. [Faculty of Applied Science, Universiti Teknologi MARA, 13500 Penang (Malaysia)

2011-03-30T23:59:59.000Z

458

Crystallization Temperature of Aqueous Lithium Bromide Solutions at Low Evaporation Temperature  

Science Conference Proceedings (OSTI)

Water- aqueous Lithium Bromide (LiBr) solutions have shown superior performance as working fluid pairs for absorption refrigeration cycles. Most of the available literature (e.g. ASHRAE Handbook of Fundamentals, etc.) provide crystallization behavior down to only 10 C. The typical evaporating temperature for an absorption chiller system is usually lower than 10 C. Hence, it is essential to have an accurate prediction of the crystallization temperature in this range in order to avoid crystallization during the design phase. We have therefore conducted a systematic study to explore the crystallization temperatures of LiBr/Water solutions that fall below an evaporating temperature of 10 C. Our preliminary studies revealed that the rate of cooling of the sample solution influences the crystallization temperature; therefore we have performed a quasi steady test where the sample was cooled gradually by reducing the sample temperature in small steps. Results from this study are reported in this paper and can be used to extend the data available in open literature.

Kisari, Padmaja [ORNL; Wang, Kai [ORNL; Abdelaziz, Omar [ORNL; Vineyard, Edward Allan [ORNL

2010-01-01T23:59:59.000Z

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Evaporative Concentration of 100x J13 Ground Water at 60% Relative Humidity and 90C  

Science Conference Proceedings (OSTI)

In these experiments we studied the behavior of a synthetic concentrated J13 solution as it comes in contact with a Ni-Cr-Mo-alloy selected for waste canisters in the designated high-level nuclear-waste repository at Yucca Mountain, Nevada. Concentrated synthetic J13 solution was allowed to drip slowly onto heated test specimens (90 C, 60% relative humidity) where the water moved down the surface of the spe