Research On Heat Dissipation Method Of Semiconductor Refrigeration System Based On Solar Energy

China is a big consumer of fossil fuels.The import rate of fossil fuels has always been high,although China has a vast territory and abundant resources.This energy structure is very unfavorable for economic development,and the burning of fossil fuels brings a series of environmental problems,which is completely contrary to the policy of Peak Carbon Dioxide Emissions and Carbon Neutrality proposed by China.However,solar energy resources are very rich in the country.The use of solar power is not only inexpensive,but also environment-friendly,without generating waste gas,water or residue.It can not only protect the environment,but also change the energy structure of the country and reduce the import rate of fossil fuels.According the Peltier Effect,semiconductor refrigeration chips are used to achieve rapid cooling without refrigerants and the sliding of mechanical parts,which save energy and protect the environment.This paper combines PV and semiconductor refrigeration to build a semiconductor refrigeration system based on solar energy.Firstly,the cooling load of the system and the inclination of the solar panel are calculated,which is convenient for the subsequent selection of the energy supply part,the cooling device part and the heat dissipation part,and an experimental platform is built.Then,an experimental study was carried out.In order to find the best working current of the system,the experiment of the change of the cooling effect with the current was carried out.The results show that when the total current is 20A（that is,the current through each semiconductor cooling chip is 4A）,the cooling effect of the semiconductor cooling chip is the best.After that,experiments were carried out by changing the water temperature,the number of fans at the cold end of the semiconductor cooling chips,and the number of the semiconductor cooling chips to increase the cooling capacity of the system.Experimental results show that the cooling capacity of the system can achieve the best when the water temperature is10°C,the number of fans is 4,and the number of semiconductor refrigeration chips is5.Finally,in order to improve the heat dissipation effect of the hot end of the semiconductor refrigeration chips,the thermal simulation software Fluent was used to carry out simulation optimization,mainly from the internal structure of the water block and the different inlet flow rates.The simulation results show that structure 3 has better effect than other structures because of significantly improving eddies on the left and right ends of the water block and more uniform temperature at the position of No.1 semiconductor cooling chip.Compared with the original structure,in Structure 3,the temperature difference decreased from 2.90℃ to 0.99℃,a decrease of 65.86%;the average temperature decreased from 15.55℃ to 13.89℃,a decrease of 10.68%;the maximum temperature difference at No.5 position decreased from 3.66℃ to 2.91℃,a decrease of 20.49%;and the average temperature from 14.64℃ to 12.85℃,a decrease of 12.23%.It can be seen that the effect of the structural optimization in the water block is obvious,and the problems existing in the original structure can be perfectly solved.With the increase of the flow velocity,the maximum temperature difference and the average temperature of No.1 and No.5 positions both decrease,but the effects of1.0m/s and 1.5m/s are obviously better than that of 0.5m/s.At the interface,the average temperatures at flow rates of 1.0m/s and 1.5m/s are 13.72°C and 13.18°C,respectively;at Position 1,the maximum temperature differences are 0.94°C and0.83°C and the average temperatures are 14.66°C and 14.08°C,respectively;at Position 5,the maximum temperature difference are 2.96°C and 2.48°C and the average temperature is 13.57°C and 13.05°C,respectively.It can be seen from the data that the effects of 1.0m/s and 1.5m/s are not much different,and the effect of1.5m/s is slightly better.Because the cooling rate of the constant temperature water tank is limited,it is more suitable to choose the flow velocity of 1.0m/s considering the compatibility with the constant temperature water tank.