Research Of Heat Transfer Characteristics Of Automotive Exhaust-based Thermoelectric Generator Cold End

National car ownership is increasing,and so is energy consumption.The energy saving and emission reduction technology of automobiles has always been the focus of the research.Thermoelectric generation technology based on automotive exhaust,which is considered to have great prospects for development,can convert low-grade waste heat in exhaust into electric energy and improve the fuel efficiency of vehicle.In the thermoelectric generator system,the cold end is an important part.The cooling capacity of the cold end directly determines the thermoelectric conversion efficiency of the entire system.Therefore,the study of cold end is of great significance for the application of the thermoelectric generator system.In this paper,firstly,the heat transfer model of thermoelectric generation system is established based on the structure of thermoelectric generation system and the heat transfer theory.The evaluation criteria of the cold end are put forward,which can provide the theoretical basis for the later numerical simulation analysis.Secondly,the multi-inlet cooling water tank structure is proposed by analyzing the shortage of the single inlet cooling water tank.The cooling water tanks with different inlet numbers are compared in terms of the cooling capacity,the pump power consumption caused by the coolant pressure drop,and the power difference between the module output power and the pump power consumption.Combined with the actual situation,the double inlet cooling water tank is considered to have relatively good comprehensive performance.At the same time,the height and width of the double inlet cooling water tank are also studied,and the theoretical basis for the design of height and width is proposed.Subsequently,the influence of the dimpled structure on the performance of cold end is studied,and the conclusion that the dimpled structure can improve the performance of the cold end is indicated.The comprehensive performance of the local dimpled cooling water tank and the uniform dimpled cooling water tank are compared and analyzed.The results show that the two cooling water tanks have similar comprehensive performance.The local dimpled cooling water tank with a relatively simple structure is selected as a further research object.Optimized design of the diameter and depth of the dimple is carried out.The central composite design method is used to design the experimental scheme,and the response surface model is used as the approximate model.The adaptive simulated annealing algorithm is used to screen the optimal solution.The localized dimple structure with excellent comprehensive performance is obtained.Finally,the model of thermoelectric generation system based on automotive exhaust was established,which includes the exhaust waste heat collection channel,the thermoelectric modules and the cooling water tank.And there is a comparative analysis of the thermoelectric generation system using single inlet cooling water tank and double inlet local dimpled cooling water tank.The results show that the comprehensive performance of the double inlet local dimpled cooling water tank is improved by 8% to 11%,compared to the thermoelectric generation system using a single inlet cooling water tank.