Performance Optimization Of PV/T System Based On The Field Synergy Theory

In recent years,the sustainable application of solar energy has attracted wide attention all over the world.In 2020,the state proposed"3060 double carbon"plan,and the sustainable application of solar energy in buildings would usher in new opportunities and challenges.As a zero carbon and sustainable development technology,photovoltaic power generation has developed rapidly.At present,the field of photovoltaic power generation is facing a challenge,that is,the high temperature generated by photovoltaic modules would lead to the reduction of power generation efficiency.In order to solve this problem,researchers put forward the photovoltaic photothermal integration technology,namely PV/T technology.The birth of this technology made it possible to use the electric energy and heat energy of the system at the same time.This paper mainly focused on the design and application of cooling channel.The innovation of this study:Based on the field synergy theory and bionics theory,three new cooling channel structures were proposed,which provided technical support for the promotion of solar thermal conversion.In this study,two types of cooling channels are proposed,one is channel,the other is pipe.Based on the field synergy theory,a wedge-shaped porous channel and a corrugated channel were proposed.Based on the bionics theory,a leaf like bionics cooling pipe was proposed.The heat transfer process and energy conversion efficiency of the PV/T system were analyzed and discussed in detail.According to the structural characteristics of three new cooling channels,the model was established and verified by using the existing literature.After verifying the reliability of the model,this paper carried out the related simulation research.1)The structure of the channel was optimized,and the influence of structural parameters on the heat transfer performance of the channel was explored.The effect of the size,number and distribution of the holes on the temperature field was studied.The optimal structural parameters of the wedge-shaped porous channel were obtained.2)Based on the optimal structure parameters,the effects of solar radiation,inlet mass flow rate and inlet temperature on the thermoelectric output performance of PV/T system were discussed.The research results focused on the influence of the structure size and external parameters of the new channel on the efficiency of the new PV/T system.For the wedge-shaped porous channel,it was recommended that the holes close to the outlet should be arranged densely.The optimized hole diameter is 0.005 m.For the shark dorsal fin type channel,the optimal structure is that the channel thickness is 0.03～0.05m,the serrated peak is 0.02～0.035m,and the serrated width is 0.01m.The total efficiency of the PV/T system with the new channels is 4%～5%higher than that of the traditional PV/T system.For the bionic leaf like channel,its structure should be primary branch,and the bifurcation angle should be 15°～40°.The cooling performance of the three new channels is better when the solar radiation is high,so it is recommended that the solar radiation is greater than 1000 W/m~2.In comparison,the leaf-like channel has better energy gain.However,the wedge-shaped porous channel and the shark dorsal fin type channel are widely used in both air cooling and water cooling.