Research On Performance Of Membrane-thermoelectric Coupling Total Heat Recovery System

In the process of rapid economic and technological development,the issues of environmental governance and sustainable energy use have come into the public eye,people’s requirements for the living environment are also increasing,not only to get a high quality,healthy living environment,but also to reduce energy consumption.The fresh air supply technology using waste heat recovery can alleviate the contradiction between increasing energy consumption and ensuring high quality fresh air.However,the former heat exchanger has the problems of low thermal efficiency and large energy consumption,which limits the development and application of heat exchanger.Therefore,it is of great significance to improve the performance of heat exchanger.Membrane-thermocoupling ventilation heat exchange system is based on membrane full heat exchanger and thermoelectric refrigeration technology,the use of membrane full heat exchanger to recover indoor exhaust energy to cool or heat the outdoor new air,and then through the thermoelectric refrigeration module for the secondary treatment of new air delivery.In this paper,a membrane-thermoelectrically coupled ventilation heat exchange system is established,which is intended to meet the thermal comfort requirements of the room by adjusting the input current of the thermoelectric device,and on this basis,the film heat exchanger model and the thermoelectric model are calculated numerically using the finite differential method and iterative method respectively,and the influence of parameter changes such as membrane core runner height and new wind volume flow in the coupling system on the operating capacity of the system is analyzed.The performance factor of the system is defined and can be used to evaluate the overall heating/cooling capacity of the coupled system.The simulation results show that the optimal channel height of the membrane core is1.5m,considering the performance of the coupling system and the heating/cooling capacity.In summer working conditions,the optimal inlet flow of fresh air in the system is 80m~3/h,the optimal input current value of thermoelectric module is 1.5A when the indoor air supply temperature is set at 24℃,the average summer cooling capacity can reach 680 W,and the treatment temperature difference of fresh air is 9.13℃.In winter,the optimal inlet flow of fresh air in the system is 100 m ~3 /h,and the optimal input current value of thermoelectric module is 2A when the indoor air supply temperature is set at 18℃.In summer,the average heat generation can reach 592 W,and the temperature difference of fresh air treatment is 9.7℃.Thus,it can be seen that the coupled heat exchange system has good performance advantages.The larger the processing temperature difference of the thermoelectric system is,the smaller the COP of the system is,and vice versa.When the fresh air flow rate is fixed,the heat and humidity exchange efficiency of the system decreases with the increase of the channel height of the membrane core,while the decrease of the fresh air flow rate increases the heat and humidity exchange efficiency of the system.Therefore,in the selection of system parameters,the purpose and conditions of use should be comprehensively considered,and the maximization of heat and moisture exchange efficiency should not be blindly pursued.The simulation results also provide a theoretical basis for the structural optimization and practical application of the membrane-thermoelectric coupling ventilation system.