The Experts below are selected from a list of 4176 Experts worldwide ranked by ideXlab platform
Hongguang Jin - One of the best experts on this subject based on the ideXlab platform.
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test of a Solar parabolic trough collector with rotatable axis tracking
Applied Energy, 2017Co-Authors: Ruilin Wang, Hui Hong, Jie Sun, Hongguang JinAbstract:Abstract The concentrating Solar power is a promising technology for scalable Solar electricity. The conversion of concentrated sunlight into heat is of paramount importance in the concentrating Solar power. The current commercial parabolic trough collector has an annual average efficiency of approximately 50%, and the poor efficiency mainly results from the cosine loss. In this paper, a 300-kWth Solar parabolic trough collector with north-south and rotatable axis tracking is originally presented. The rotatable steel-support frame and the slide rail can achieve the horizontal rotation of the parabolic trough collector. The rotation of the collector can change the surface azimuth Angle of the collector, further reducing the Solar Incidence Angle and thus reducing the cosine loss. Two patterns of tracking are adopted in this prototype. In summer, the Solar Incidence Angle is small, and the north-south axis tracking is adopted. In winter, the Solar Incidence Angle is large, and the cosine loss is serious, so using the rotatable axis tracking enables more Solar irradiation to be harvested. The experimental results show that, by using the rotatable axis tracking, the daily average efficiency can be enhanced from 43% to 48% in winter. This study provides a promising approach for effectively reducing the cosine loss for the scalable parabolic trough collector, providing the possibility of improving the annual average collector efficiency and realizing cost-effective Solar energy use.
Aldo Steinfeld - One of the best experts on this subject based on the ideXlab platform.
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an air based corrugated cavity receiver for Solar parabolic trough concentrators
Applied Energy, 2015Co-Authors: Roman Bader, Andrea Pedretti, Maurizio Barbato, Aldo SteinfeldAbstract:A tubular cavity-receiver that uses air as the heat transfer fluid is evaluated numerically using a validated heat transfer model. The receiver is designed for use on a large-span (9m net concentrator aperture width) Solar parabolic trough concentrator. Through the combination of a parabolic primary concentrator with a nonimaging secondary concentrator, the collector reaches a Solar concentration ratio of 97.5. Four different receiver configurations are considered, with smooth or V-corrugated absorber tube and single- or double-glazed aperture window. The collector’s performance is characterized by its optical efficiency and heat loss. The optical efficiency is determined with the Monte Carlo ray-tracing method. Radiative heat exchange inside the receiver is calculated with the net radiation method. The 2D steady-state energy equation, which couples conductive, convective, and radiative heat transfer, is solved for the solid domains of the receiver cross-section, using finite-volume techniques. Simulations for Sevilla/Spain at the summer solstice at Solar noon (direct normal Solar irradiance: 847Wm−2, Solar Incidence Angle: 13.9°) yield collector efficiencies between 60% and 65% at a heat transfer fluid temperature of 125°C and between 37% and 42% at 500°C, depending on the receiver configuration. The optical losses amount to more than 30% of the incident Solar radiation and constitute the largest source of energy loss. For a 200m long collector module operated between 300 and 500°C, the isentropic pumping power required to pump the HTF through the receiver is between 11 and 17kW.
Bjorn Karlsson - One of the best experts on this subject based on the ideXlab platform.
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minimizing the impact of shading at oblique Solar Angles in a fully enclosed asymmetric concentrating pvt collector
Energy Procedia, 2014Co-Authors: Joao Gomes, Linkesh Diwan, Ricardo Bernardo, Bjorn KarlssonAbstract:PVT collectors produce both electricity and heat from the same area. PVT collectors with low concentration factor allow both stationary and tracking configurations. For stationary or single axis tracking, the daily variation in the Solar Incidence Angle can cause significant shading in concentrating collectors. Shading has a larger impact on PV than on thermal collectors and thus the evaluations was more focused on the electrical part. Several prototype versions of a novel design for a concentrating asymmetric PVT collector have been tested and compared. One tested improvement was replacing the reflective end gables with transparent end gables. Another improvement was to use different cell sizes. These actions were expected to minimize the impact of the shading at oblique Solar Incidence Angles. The second action was found to be more beneficial than the first. Measurements were also performed in the Solar simulator to fully understand the impact of shading in cell strings with 1/6 the size of standard cells. The latest version of the PVT was found to have, at 25oC and 1000w/m 2 , a collector efficiency of 13,7%, a cell area efficiency of 20,3% and an electrical power output of 237W. Lower side of the receiver was producing 58% of the total power.
Ruilin Wang - One of the best experts on this subject based on the ideXlab platform.
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test of a Solar parabolic trough collector with rotatable axis tracking
Applied Energy, 2017Co-Authors: Ruilin Wang, Hui Hong, Jie Sun, Hongguang JinAbstract:Abstract The concentrating Solar power is a promising technology for scalable Solar electricity. The conversion of concentrated sunlight into heat is of paramount importance in the concentrating Solar power. The current commercial parabolic trough collector has an annual average efficiency of approximately 50%, and the poor efficiency mainly results from the cosine loss. In this paper, a 300-kWth Solar parabolic trough collector with north-south and rotatable axis tracking is originally presented. The rotatable steel-support frame and the slide rail can achieve the horizontal rotation of the parabolic trough collector. The rotation of the collector can change the surface azimuth Angle of the collector, further reducing the Solar Incidence Angle and thus reducing the cosine loss. Two patterns of tracking are adopted in this prototype. In summer, the Solar Incidence Angle is small, and the north-south axis tracking is adopted. In winter, the Solar Incidence Angle is large, and the cosine loss is serious, so using the rotatable axis tracking enables more Solar irradiation to be harvested. The experimental results show that, by using the rotatable axis tracking, the daily average efficiency can be enhanced from 43% to 48% in winter. This study provides a promising approach for effectively reducing the cosine loss for the scalable parabolic trough collector, providing the possibility of improving the annual average collector efficiency and realizing cost-effective Solar energy use.
Hui Hong - One of the best experts on this subject based on the ideXlab platform.
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test of a Solar parabolic trough collector with rotatable axis tracking
Applied Energy, 2017Co-Authors: Ruilin Wang, Hui Hong, Jie Sun, Hongguang JinAbstract:Abstract The concentrating Solar power is a promising technology for scalable Solar electricity. The conversion of concentrated sunlight into heat is of paramount importance in the concentrating Solar power. The current commercial parabolic trough collector has an annual average efficiency of approximately 50%, and the poor efficiency mainly results from the cosine loss. In this paper, a 300-kWth Solar parabolic trough collector with north-south and rotatable axis tracking is originally presented. The rotatable steel-support frame and the slide rail can achieve the horizontal rotation of the parabolic trough collector. The rotation of the collector can change the surface azimuth Angle of the collector, further reducing the Solar Incidence Angle and thus reducing the cosine loss. Two patterns of tracking are adopted in this prototype. In summer, the Solar Incidence Angle is small, and the north-south axis tracking is adopted. In winter, the Solar Incidence Angle is large, and the cosine loss is serious, so using the rotatable axis tracking enables more Solar irradiation to be harvested. The experimental results show that, by using the rotatable axis tracking, the daily average efficiency can be enhanced from 43% to 48% in winter. This study provides a promising approach for effectively reducing the cosine loss for the scalable parabolic trough collector, providing the possibility of improving the annual average collector efficiency and realizing cost-effective Solar energy use.