In the light of the thermo-electric conversion principle, a model for predicting the performance of a solar thermophotovoltaic system is presented. The temperature distributions of the emitter for different concentrat...In the light of the thermo-electric conversion principle, a model for predicting the performance of a solar thermophotovoltaic system is presented. The temperature distributions of the emitter for different concentrator ratios are numerically computed and the influence of the concentrator ratio on the system performance is analyzed. Numerical results show that the emitter temperature and the system efficiency increase with increase of the concentrator ratio. The effects of some other factors such as the spectral filter, cell temperature, and the reflectivity of the top and bottom surfaces of the emitter on the conversion performance of the STPV system are discussed.展开更多
A model for predicting the performance of the emitter in the solar thermophotovoltaic (STPV) system is presented in this article. The effect of non-parallelism of sun rays on concentration capability is numerically ca...A model for predicting the performance of the emitter in the solar thermophotovoltaic (STPV) system is presented in this article. The effect of non-parallelism of sun rays on concentration capability is numerically calculated,also the flow field in the emitter cavity and the temperature distribution of the emitter with different inlet conditions are compared. Numerical results show that free convection of the air inside the emitter cavity has great effect on the emitter temperature and may reduce the electricity output of the cells. At last,a new kind of selective film is put forward. Through optimizing the cut-off wavelength of a selective film,radiation loss is further reduced and system efficiency is improved.展开更多
Based on the second law of thermodynamics,a theoretical model is established for efficiency analysis and optimization of a solar thermophotovoltaic (STPV) system. The entropy generation in the photo-electricity conver...Based on the second law of thermodynamics,a theoretical model is established for efficiency analysis and optimization of a solar thermophotovoltaic (STPV) system. The entropy generation in the photo-electricity conversion process is numerically calculated and analyzed for the component modules involved in the whole system assembly. The effects of the emitter temperature,concentration ratio,energy bandgap,cell temperature and the transmissivity of the filter on the entropy and the efficiency are investigated. Meanwhile,the conversion efficiencies of the modules are discussed. The following results are obtained:at first the entropy generation of the system reduces but then increases with the rise of the emitter temperature. When the concentration ratio improves,the entropy generation of the system falls. The increase of the bandgap value and chemical potential of the cell also causes the reduction of the entropy generation. Along with the increase of the cell temperature,the entropy generation increases and the conversion efficiency of the STPV system decreases.展开更多
Road tunnels consume a large amount of energy,especially in the Canadian cold climate,where the roads are heated electrically or deicing during the winter.For a more sustainable and resilient road tunnel energy system...Road tunnels consume a large amount of energy,especially in the Canadian cold climate,where the roads are heated electrically or deicing during the winter.For a more sustainable and resilient road tunnel energy system,we conducted an exploratory study on installing a semi-transparent photovoltaic(STPV)canopy at the entrances and exits of a tunnel under a river.The proposed system generates solar-powered electricity,improves thermal and visual conditions,and reduces energy loads.In this study,field measurements of road surface temperature and air temperature were conducted,and numerical simulations with and without STPV were performed to study air and road surface temperatures under different traffic speeds.The field measurements show the road surface temperatures are higher than the air temperature on average.The interior air and road surface temperature were measured to be above 0°C,even though the outdoor temperature is far below 0°C,thus significantly reducing the need for deicing in winter using salts.The simulations show that the air and surface temperatures elevate due to the solar transmission heat through the STPV canopy,thus reducing deicing energy consumption significantly.The fire safety analysis also showed that the proposed system's top opening should be located near the tunnel entrance instead of the canopy entrance for better smoke exhaust during a fire.展开更多
Contemporary office buildings have been calling attention for intense use of glass on their façades.This way,glazed areas in such buildings may favor the access to natural light and contribute to power generation...Contemporary office buildings have been calling attention for intense use of glass on their façades.This way,glazed areas in such buildings may favor the access to natural light and contribute to power generation through photovoltaic systems.However,the application of STPV(Semi-Transparent Photovoltaic)may interfere with the building’s energy performance and good use of daylight.So,this work aims to assess daylighting and thermoenergetic performances in an office room located in southern Brazil,with different types of STPV applied to the building’s glasses.This study was carried out through computer simulation,integrating software’s Rhinoceros with DIVA plugin and EnergyPlus.Results have shown that the application of STPV with proper transparency percentage provides access to daylighting and increases visual comfort for occupants,and also contributes to the building’s energy balance,as it may save from 9.6%to 28%in energy.Its use,in the climatic context analyzed,has boosted energy consumption for cooling and for artificial lighting;however,photovoltaic generation was higher and thus compensated for the increase caused by the system.展开更多
该文提出了1种半透明光伏窗太阳得热系数(Solar heat gain coefficient,SHGC)的简易室外测试方法。首先通过室外实验研究了不同运行状态下半透明光伏窗的SHGC,实验结果表明,光伏窗开路(Open circuit,OC)状态下的SHGC显著高于最大功率点(...该文提出了1种半透明光伏窗太阳得热系数(Solar heat gain coefficient,SHGC)的简易室外测试方法。首先通过室外实验研究了不同运行状态下半透明光伏窗的SHGC,实验结果表明,光伏窗开路(Open circuit,OC)状态下的SHGC显著高于最大功率点(Maximum power point,MPP)状态下的SHGC,两者的SHGC差异最高可达11.5%;其次,通过理论分析研究了电池覆盖率对不同运行状态下光伏窗SHGC的影响,同时探究了不同类型光伏窗在上述2种运行状态下的SHGC差异。该文的分析结果将为更准确地评价光伏窗的热工性能和空调负荷计算提供指导,并推动光伏建筑一体化技术发展。展开更多
基金the Natural Science Foundation of Jiangsu Province of China(Grant No.BK2007726)
文摘In the light of the thermo-electric conversion principle, a model for predicting the performance of a solar thermophotovoltaic system is presented. The temperature distributions of the emitter for different concentrator ratios are numerically computed and the influence of the concentrator ratio on the system performance is analyzed. Numerical results show that the emitter temperature and the system efficiency increase with increase of the concentrator ratio. The effects of some other factors such as the spectral filter, cell temperature, and the reflectivity of the top and bottom surfaces of the emitter on the conversion performance of the STPV system are discussed.
基金Supported by the Natural Science Foundation of Jiangsu Province of China (Grant No. BK2007726)
文摘A model for predicting the performance of the emitter in the solar thermophotovoltaic (STPV) system is presented in this article. The effect of non-parallelism of sun rays on concentration capability is numerically calculated,also the flow field in the emitter cavity and the temperature distribution of the emitter with different inlet conditions are compared. Numerical results show that free convection of the air inside the emitter cavity has great effect on the emitter temperature and may reduce the electricity output of the cells. At last,a new kind of selective film is put forward. Through optimizing the cut-off wavelength of a selective film,radiation loss is further reduced and system efficiency is improved.
文摘Based on the second law of thermodynamics,a theoretical model is established for efficiency analysis and optimization of a solar thermophotovoltaic (STPV) system. The entropy generation in the photo-electricity conversion process is numerically calculated and analyzed for the component modules involved in the whole system assembly. The effects of the emitter temperature,concentration ratio,energy bandgap,cell temperature and the transmissivity of the filter on the entropy and the efficiency are investigated. Meanwhile,the conversion efficiencies of the modules are discussed. The following results are obtained:at first the entropy generation of the system reduces but then increases with the rise of the emitter temperature. When the concentration ratio improves,the entropy generation of the system falls. The increase of the bandgap value and chemical potential of the cell also causes the reduction of the entropy generation. Along with the increase of the cell temperature,the entropy generation increases and the conversion efficiency of the STPV system decreases.
基金This research project was supported by the Ministry of Transport of Quebec and the NSERC Discovery Grants[#RGPIN-2018-06734]from Canada5s Natural Sciences and Engineering Research Council.
文摘Road tunnels consume a large amount of energy,especially in the Canadian cold climate,where the roads are heated electrically or deicing during the winter.For a more sustainable and resilient road tunnel energy system,we conducted an exploratory study on installing a semi-transparent photovoltaic(STPV)canopy at the entrances and exits of a tunnel under a river.The proposed system generates solar-powered electricity,improves thermal and visual conditions,and reduces energy loads.In this study,field measurements of road surface temperature and air temperature were conducted,and numerical simulations with and without STPV were performed to study air and road surface temperatures under different traffic speeds.The field measurements show the road surface temperatures are higher than the air temperature on average.The interior air and road surface temperature were measured to be above 0°C,even though the outdoor temperature is far below 0°C,thus significantly reducing the need for deicing in winter using salts.The simulations show that the air and surface temperatures elevate due to the solar transmission heat through the STPV canopy,thus reducing deicing energy consumption significantly.The fire safety analysis also showed that the proposed system's top opening should be located near the tunnel entrance instead of the canopy entrance for better smoke exhaust during a fire.
基金Thanks to GES3E for the support to the development of this research.
文摘Contemporary office buildings have been calling attention for intense use of glass on their façades.This way,glazed areas in such buildings may favor the access to natural light and contribute to power generation through photovoltaic systems.However,the application of STPV(Semi-Transparent Photovoltaic)may interfere with the building’s energy performance and good use of daylight.So,this work aims to assess daylighting and thermoenergetic performances in an office room located in southern Brazil,with different types of STPV applied to the building’s glasses.This study was carried out through computer simulation,integrating software’s Rhinoceros with DIVA plugin and EnergyPlus.Results have shown that the application of STPV with proper transparency percentage provides access to daylighting and increases visual comfort for occupants,and also contributes to the building’s energy balance,as it may save from 9.6%to 28%in energy.Its use,in the climatic context analyzed,has boosted energy consumption for cooling and for artificial lighting;however,photovoltaic generation was higher and thus compensated for the increase caused by the system.
文摘该文提出了1种半透明光伏窗太阳得热系数(Solar heat gain coefficient,SHGC)的简易室外测试方法。首先通过室外实验研究了不同运行状态下半透明光伏窗的SHGC,实验结果表明,光伏窗开路(Open circuit,OC)状态下的SHGC显著高于最大功率点(Maximum power point,MPP)状态下的SHGC,两者的SHGC差异最高可达11.5%;其次,通过理论分析研究了电池覆盖率对不同运行状态下光伏窗SHGC的影响,同时探究了不同类型光伏窗在上述2种运行状态下的SHGC差异。该文的分析结果将为更准确地评价光伏窗的热工性能和空调负荷计算提供指导,并推动光伏建筑一体化技术发展。
