PV （photovoltaic） solar panels generally produce electricity in the 6% to 12% efficiency range, the rest is being dissipated in thermal losses. To recover this amount, hybrid photovoltaic thermal systems （PV/T） ha...PV （photovoltaic） solar panels generally produce electricity in the 6% to 12% efficiency range, the rest is being dissipated in thermal losses. To recover this amount, hybrid photovoltaic thermal systems （PV/T） have been devised. These are devices that simultaneously convert solar energy into electricity and heat. It is thus interesting to study the PV/T system as part of a closed loop single phase water CDU （coolant distribution unit） in laminar forced convection. In particular, the analysis was conducted on the optimal cooling performance of the thermal part, testing polynomial channel profiles of varying order （from zero to fourth） for channels of a real industrial module heat sink, under the following conditions： ideal flux of 1,000 W/m2 on one side, insulation on the opposite side, periodic conditions on the remaining sides, fully developed thermal and velocity profile in laminar flow of water. Through the use of a genetic algorithm, we have optimized the shape of the channel＇s sidewalls in terms of heat transfer maximization. In terms of Nusselt number, results show that fourth order profiles are the most efficient. When limits to allowable pressure loss and module weight are introduced, these bring generally to a lower efficiency of the system than the unconstrained case.展开更多
直膨式太阳能光伏光热(photovoltaic-thermal,PVT)热泵是一种综合利用太阳能资源的新型高效技术。为探究不同环境条件以及系统配置方式对直膨式太阳能PVT热泵热水系统运行性能的影响,基于能量平衡原理在Matlab平台上建立了系统的仿真模...直膨式太阳能光伏光热(photovoltaic-thermal,PVT)热泵是一种综合利用太阳能资源的新型高效技术。为探究不同环境条件以及系统配置方式对直膨式太阳能PVT热泵热水系统运行性能的影响,基于能量平衡原理在Matlab平台上建立了系统的仿真模型,基于临港地区的环境数据,分析了各季节典型日下不同配置系统的热水供应性能以及发电增益的全年波动情况。结果表明,随压缩机理论输气量的减小,热水系统的性能系数(coefficient of performance,COP)有所提高,但所需的加热时间增加,系统的全年发电增益随理论输气量的减小而减小。展开更多
文摘PV （photovoltaic） solar panels generally produce electricity in the 6% to 12% efficiency range, the rest is being dissipated in thermal losses. To recover this amount, hybrid photovoltaic thermal systems （PV/T） have been devised. These are devices that simultaneously convert solar energy into electricity and heat. It is thus interesting to study the PV/T system as part of a closed loop single phase water CDU （coolant distribution unit） in laminar forced convection. In particular, the analysis was conducted on the optimal cooling performance of the thermal part, testing polynomial channel profiles of varying order （from zero to fourth） for channels of a real industrial module heat sink, under the following conditions： ideal flux of 1,000 W/m2 on one side, insulation on the opposite side, periodic conditions on the remaining sides, fully developed thermal and velocity profile in laminar flow of water. Through the use of a genetic algorithm, we have optimized the shape of the channel＇s sidewalls in terms of heat transfer maximization. In terms of Nusselt number, results show that fourth order profiles are the most efficient. When limits to allowable pressure loss and module weight are introduced, these bring generally to a lower efficiency of the system than the unconstrained case.
文摘直膨式太阳能光伏光热(photovoltaic-thermal,PVT)热泵是一种综合利用太阳能资源的新型高效技术。为探究不同环境条件以及系统配置方式对直膨式太阳能PVT热泵热水系统运行性能的影响,基于能量平衡原理在Matlab平台上建立了系统的仿真模型,基于临港地区的环境数据,分析了各季节典型日下不同配置系统的热水供应性能以及发电增益的全年波动情况。结果表明,随压缩机理论输气量的减小,热水系统的性能系数(coefficient of performance,COP)有所提高,但所需的加热时间增加,系统的全年发电增益随理论输气量的减小而减小。
