Study On The Performance Of PV/T Solar Energy System With Blown Microchannel

PV/T-photovoltaic/thermal system is an energy system that combines solar photoelectricity and thermal technology to greatly improve solar energy utilization efficiency.The research of this subject is of great significance to promote the application of renewable energy and realize the sustainable development of energy in China.In our study,the actual comprehensive utilization efficiency index of solar photoelectric and thermal composite utilization system considering water pump power consumption is proposed;the change rule between the actual comprehensive utilization efficiency of PV/T system in winter and spring and the inclination angle with the ground and circulating water flow rate of PV/T component in Shanghai area is studied using the blown microchannel PV/T solar system experimental bench.For optimizing PV/T solar system operations.The inner blown microchannel heat exchanger structure of PV/T component is optimized using the CFD numerical simulation method.According to the experiments and numerical simulation,the following conclusions are drawn:1.In the winter experiments,the actual comprehensive efficiency of the system is 43.31%,47.08% and 37.96%,respectively,when the circulating water flow rate is increasing by 60 L/h,80 L/h and 100 L/h using an 18 ° inclination angle as the initial condition of the experiments;in the spring experiments,the actual comprehensive efficiency of the system is 43.52%,48.96% and 41.32%,respectively.When the experimental inclination angle is 25 ° and 32 °,the actual comprehensive efficiency of the system also shows a trend of first increase and then decrease.The experimental results show that 80 L/h circulating water flow rate is the optimal operating parameter of this PV/T system.2.In the winter experiments,under the operational condition of 80 L/h circulating water flow rate,the inclination angle of PV/T component increased from 18 ° to 25 °and then 32 °,and the actual comprehensive efficiency of the system first increased from 47.08% to 56.71% and then decreased to 52.48%;in the spring experiments,the actual comprehensive efficiency of the system first increased from 48.96% to 52.1% and then up to 59.38%.The experimental results show that the actual comprehensive efficiency of the system is different due to the increase of PV/T component inclination angle in different seasons within the test range,and the optimal inclination angle of the system is also inconsistent.The better tilt angle is 25 ° in winter and 32 ° in spring.3.Operating the system with 80 L/h circulating water flow rate and 25 ° inclination angle can achieve the highest actual comprehensive efficiency in winter experiments,and the result is 56.71%;in spring experiments,with the combination of 80 L/h circulating water flow rate and 32 °inclination angle,the actual comprehensive efficiency of the system is the highest,the result is 59.38%.4.The optimized symmetrical microchannel model can effectively improve the velocity field distribution,and the heat flux of the channel is 50.23% higher than that of the asymmetric structure.The research results of this subject are to provide basic experimental support and numerical model reference for the operation and structure optimization of blown microchannel PV/T system in spring and winter.It has experimental guiding significance and engineering application value for the research and development and promotion of the same type of PV/T system.