Performance Investigation Of Solar Photovoltaic Loop Heat Pipe Heat Pump Heating System

A new type of solar PV/LHP heat pump heating system was designed with the combination of hybrid photovoltaic/thermal technology,loop heat pipes and solar/air dual source heat pump technology in this paper.The system,which based on the solar PV-loop heat pipe technology,utilized of layout flexibility,high heat transfer efficiency,anti-freezing properties of loop heat pipe as well as the stability and widely adaptability for air temperature,are the combination of heat pump and solar PV/LHP technology.The fine mathematical model of PV/LHP operating mode and empirical models of dual heat source heat pump operating mode were designed respectively for this system.The simulation program of this PV/LHP system was programmed through Visual Basic6.0.The influence of three kinds of typical meteorological years(TRNSYS,and DEST,and China building hot environment analysis dedicated meteorological data set)data on the system's operating performance were simulated and analyzed based on the model.The influence of structural parameters like installation angle of solar collector,tube spacing and photovoltaic cover percentage on the operating performance of PV/LHP mode was analyzed based on the typical meteorological year data of TRNSYS.Besides,the influence of operating parameters like the type of refrigeration,solar radiation,air temperature and cooling water temperature on the thermoelectric properties of the model were also compared.According to the operation control method of PV/LHP and dual source heat pump,the variation of annual system operating performance and energy consumption were analyzed to meet the needs of 45 degree hot water for dwelling consumers.The outdoor experimental platform were designed to test the operating mode of PV/LHP on winter working condition.The results indicated that the TRNSYS typical meteorological years matches better than others,In the Beijing area of the collector installation angle should be adjusted according to the season two times a year;from the economic perspective,as far as possible to reduce heat pipe spacing;PV coverage rate is low,the better the performance of thermal system,but the power is reduced;the refrigerant heat transfer coefficientgreatly helps to improve the heat transfer performance system.Quantity of heat pump system in power mode power consumption of 23.41% solar photovoltaic-loop heat pipe heating mode of the annual average percentage is about 54.4%,the average annual double source heat pump system COP up to 4.3,significantly higher than the performance of air source heat pump in the area.By comparing the experimental data with the simulation results,it is found that the two are in good agreement,thus verifying the accuracy of the model and the simulation program.