Performance Study Of Heat Pipe PV/T System With Different Air Layer Structure

Loop heat pipe PV/T system has the advantages of flexible arrangement,high collector efficiency,easy building integration,and can be used in high latitude cold regions compared with traditional PV/T system.As a key component of the heat pipe PV/T system,the heat transfer characteristics of the internal air interlayer have an important impact on the temperature distribution of the PV panels and also determine the variation of the system thermoelectric performance.In this paper,we use theoretical analysis and numerical simulation to compare the performance of conventional loop heat pipe PV/T system with that of heat pipe PV/T system without air layer under typical operating conditions and longterm operating conditions,and to optimize the structure of conventional loop heat pipe PV/T system.The main research of this paper includes the following aspects.(1)Introduce the main structure and working principle of the conventional loop heat pipe PV/T system,and establish the numerical model of the system collector/evaporator with the help of CFD software.(2)The validity of the model was verified by comparing experimental and simulated data.Based on the climatic conditions in Beijing,typical daily and long-term operation performance simulations of the conventional loop heat pipe PV/T system and the airless heat pipe PV/T system were carried out by Fluent software.The temperature distribution characteristics of the collector/evaporator of the two systems under typical operating conditions were compared and analyzed,and it was found that the absorber plate temperature distribution of the airless heat pipe PV/T system was more uniform and the average temperature was lower than that of the conventional loop heat pipe PV/T system.And the typical working conditions and year-round operation performance change characteristics of the two systems were discussed from the system’s electrical and thermal conversion efficiency.The optimal installation inclination angle and optimal air layer thickness of the conventional loop heat pipe PV/T system in Beijing were also determined.(3)Based on the optimal installation tilt angle and optimal air layer thickness,electric water heater system and gas water heater system were selected as benchmark systems to further explore the advantages of conventional loop heat pipe PV/T system in terms of socioeconomic benefits in Beijing area.