skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Evacuated tube solar collector with multifunctional absorber layers

Authors:
; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1397418
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Solar Energy
Additional Journal Information:
Journal Volume: 146; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-10-04 21:01:24; Journal ID: ISSN 0038-092X
Publisher:
Elsevier
Country of Publication:
United States
Language:
English

Citation Formats

Sobhansarbandi, Sarvenaz, Martinez, Patricia M., Papadimitratos, Alexios, Zakhidov, Anvar, and Hassanipour, Fatemeh. Evacuated tube solar collector with multifunctional absorber layers. United States: N. p., 2017. Web. doi:10.1016/j.solener.2017.02.038.
Sobhansarbandi, Sarvenaz, Martinez, Patricia M., Papadimitratos, Alexios, Zakhidov, Anvar, & Hassanipour, Fatemeh. Evacuated tube solar collector with multifunctional absorber layers. United States. doi:10.1016/j.solener.2017.02.038.
Sobhansarbandi, Sarvenaz, Martinez, Patricia M., Papadimitratos, Alexios, Zakhidov, Anvar, and Hassanipour, Fatemeh. Sat . "Evacuated tube solar collector with multifunctional absorber layers". United States. doi:10.1016/j.solener.2017.02.038.
@article{osti_1397418,
title = {Evacuated tube solar collector with multifunctional absorber layers},
author = {Sobhansarbandi, Sarvenaz and Martinez, Patricia M. and Papadimitratos, Alexios and Zakhidov, Anvar and Hassanipour, Fatemeh},
abstractNote = {},
doi = {10.1016/j.solener.2017.02.038},
journal = {Solar Energy},
number = C,
volume = 146,
place = {United States},
year = {Sat Apr 01 00:00:00 EDT 2017},
month = {Sat Apr 01 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.solener.2017.02.038

Citation Metrics:
Cited by: 1work
Citation information provided by
Web of Science

Save / Share:
  • An experimental study of an evacuated-tube, integral-collector-storage water heater was conducted in an indoor solar simulator. Useful collected energy, radiation-induced stratification and draw-induced mixing are characterized in eight trials in which test duration, initial tank water temperature, flow rate during withdrawal of heated water from the collector, withdrawal pattern and reflectance of the backplane were varied. All tests were performed at nominal irradiance of 900 W/m{sup 2}, normal incidence, and collector slope of 45 degrees. The capability of the TRNSYS integral collector storage model to predict performance for operating conditions for which data are assumed to be unavailable was assessed.more » Using data from one experimental trial, optical efficiency ({tau}{alpha}) of the collector was determined by matching predicted useful energy gain to measured gain. Effectiveness of the calibrated model was based on a comparison of predicted gains to measured values obtained in the remaining seven trials. For five of seven trials, predicted performance is within 9% of measured performance and less than experimental error. For the other two trials, predicted performance is within 15% of measured performance. The higher discrepancies may be partially due to experimental conditions not modeled such as heating of the piping connecting the collector to the test facility and inadequate characterization of back-plane reflectivity. The model does not predict radiation-induced stratification. Although the effect of mixing during draws can be approximated by specifying the number of fully mixed volume segments in the tanks, selection of number of nodes requires knowledge of the behavior of the system. The number of nodes selected has minimal impact on total energy gain, but does affect the temperature of water delivered to the load.« less
  • We investigated experimentally the pressure dependency of the gas heat conduction in an evacuated plate-in-tube solar collector. A stationary heat loss experiment was built up with an electrically heated real-size collector model. The gas pressure was varied from 10{sup -3} to 10{sup 4} Pa, the temperatures of the absorber and the casing were held at 150{degree}C (electrical heaters) and 30{degree}C (water cooling), respectively. Losses by radiation and solid conduction were determined experimentally at pressures below 0.1 Pa. At higher pressures these background losses were subtracted from the total heat losses, to receive the heat losses by gas heat conduction. Themore » experimental results were compared with approximate theoretical models. The onset of convection is in agreement with the usual theories for parallel plates taking the largest distance between the absorber and the gas tube as the plate distance. As a first approximation the pressure dependency of the gas heat conduction is described by the usual theory for parallel plates, taking the smallest distance between the absorber and the glass tube as the plate distance. 11 refs., 3 figs.« less
  • Theoretical calculations and experimental data on an evacuated tube solar collector with an air heat transfer medium are presented. The collector is a conventional flat plate design except that the front cover, instead of being made up of one or two sheets of flat glass, consists of a raft-like arrangement of evacuated glass tubes. The calculations indicate that an evacuated tube cover, together with a high heat transfer absorber, could give a solar collector with superior thermal performance. Experimental measurements are given for an air collector using uncoated evacuated tubes and a screen absorber. Results on internal temperatures are usedmore » to infer the effectiveness of the heat transfer between the absorber screen and the air flow. When account is taken of the measured absorber properties, the performance of the evacuated tube cover is in reasonable accord with the theory.« less
  • Analysis of an evacuated tubular solar collector is presented by developing a two-dimensional performance model. The collector uses a thin flat plate spanning its diameter as its absorbing surface. Energy balances are made on collector plate and tube, each considered as a separate unit. It has been found that a zero capacitance model is quite adequate when hourly meteorological data are used, and hence in this study steady state analysis of the collector is made (1). The overall loss coefficient has been assumed to be constant for the whole plate. The model also includes optical effects. The emphasis of themore » investigation is to study the two-dimensional effects in the absorber plate housed in evacuated glass cylinders. Performance curves obtained from the two-dimensional model has been compared with that of HW model. It was found that the HW model overestimates the performance.« less
  • A solar collector is disclosed comprising an elongate absorber centrally arranged in an evacuated, transparent, circular-cylindrical tube provided with a reflector in the form of a 1/3-circular cylinder in contact with the absorber.