| A heat pipe solar PV/T(photovoltaic/thermal)heat pump system was proposed in this paper.This system combined heat pipe PV/T collection system with heat pump system,the performance of heat collection mode and heating mode of this system was tested in sunny condition and cloudy condition.A mathematic model of heat pipe solar PV/T heat pump system was established and validated by the experimental data in this paper.This mathematic model consists of a dynamic distributed parameter model of heat pipe solar PV/T collection system and a quasi-steady state distributed parameter model of heat pump system.The effect of solar radiation,ambient temperature and supply temperature in condenser on the performance of system was analyzed based on the validated mathematic model.Finally,the structure optimization of the heat pipe solar PV/T heat pump system was carried out,a large capacity compressor and three heat pipe solar PV/T collectors was used in the optimized mathematic model.The effect of PV cells coverage ratio,distance between heat pipes and absorptivity of backboard on the performance of system was analyzed by the optimized mathematical model.The results are as follows:(1)This system has higher heat and electrical output power,condensation capacity and COP in sunny conditions than the cloudy conditions in both heating and heat collection mode,but the thermal and electrical efficiency was lower in sunny conditions.The electrical performance of the experimental group was higher than that of the control group both in sunny and cloudy conditions.(2)A reasonable accuracy in predicting the system's dynamic performance with a relative error of simulation and experimental value range from-14.9% to +11.5% could be obtained.The mathematical model could predict the performance of this system well and truly.(3)The heat output power,electrical output power and performance of heat pump increased,while the thermal and electrical efficiency decreased with the increasing solar radiation.The heat performance and heat pump performance increased,while the electrical performance decreased with the increasing ambient temperature.The supply temperature in the condenser has little influence of thermal and electrical performance,but the performance of heat pump decreased with the increasing supply temperature in the condenser.(4)The performance of heat pipe solar PV/T heat pump system could improve to expected level by replacing a large capacity compressor and increasing the number of heat pipe solar PV/T collectors.The thermal performance and heat pump performance increased,while the electrical performance decreased with the increasing PV packing factor.The thermal performance and heat pump performance increased,while the electrical performance decreased with the increasing PV backboard absorptivity.The performance of this system comprehensively improved with the decreasing heat pipe pitch.The experimental research and numerical simulation was carried out in this paper,which has certain reference value for the research on the optimization design and performance of heat pipe solar PV/T heat pump system. |
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