| Thermoelectric air-conditioning system is a new type of air-conditioning system which is based on thermoelectric modules and integrates thermoelectric components to provide refrigeration / heating services.On the basis of the exist ing thermoelectric air-conditioning system,this paper presents a new type of building integrated thermoelectric air-conditioning system,which skillfully integrates the thermoelectric heat pump unit into the double-layer ventilation facade and integrates the functions of refrigeration / heating and ventilation.it can be operated by direct current by photovoltaic panel(or municipal electricity).The new system uses encapsulated phase change material(PCM)as the storage heater,which can store the saturat ed electric energy generated by the solar volt plate in the form of heat / cold energy,and can also utilize the high density waste heat generated in the refrigeration mode,thus significantly improving the total performance of the system in the refrigerat ion mode(its total coefficient of performance =(cooling capacity + waste heat utilization)/power consumption).In addition,the new system also has the ability to recover cold /heat from indoor exhaust air,which will improve its COP.This paper makes a simulation study on the main components of the new building integrated thermoelectric air conditioning system(thermoelectric module and finned radiator).The optimal design(selection)of thermoelectric module and finned radiator provides a reference basis for the overall performance simulation of thermoelectric system.In addition,the C++ program is used to simulate and analyze the thermal performance of the new building integrated thermoelectric air-conditioning system with or without waste heat utilization,different operating conditions and weather conditions.Under the condition of no heat storage and no waste heat utilization,indoor ventilation and heat recovery can recover cold / heat in the refrigeration / heating mode,which can reduce / increase the temperature of the hot / cold side of the thermoelectric module,thus reduce the temperature difference between the hot and cold side of the module and improve the COP of the system.Und er the working conditions of the system with heat storage capacity: 1)in the refrigeration mode,when the room temperature is 21 ℃,the cooling capacity is 100 W,and the ambient temperature is 25 ℃,the COP of the system is 0.77 when there is no waste heat utilization,and the COP of the system is 2.0 when there is waste heat utilization.When the summer ambient temperature increased from 25 ℃ to 30 ℃,the COP of the waste heat utilization system decreased from 2.0 to 1.65,and the COP of the non-waste heat utilization system decreased from 0.77 to 0.53.2)in the heating mode,the utilization of waste heat does not affect the heating performance,and the performance under the two working conditions is completely the same.Under the condition of room temperature 18 ℃,heat supply 120 W,and the ambient temperature5 ℃,the best COP of the system is about 1.27.Taking Beijing and Changsha as an example,the average ambient temperature is-2 ℃ and 6 ℃ respectively.The simulation results show that the system COP of Beijing and Changsha are 1.10 and1.31 respectively.The waste heat utilization in the refrigeration mode significantly improves the overall performance of the system;the higher the ambient temperature in summer,the smaller the COP of the system;the higher the ambient temperature in winter,the greater the COP of the system.The proposal of a new type of building integrated thermoelectric air-conditioning system will become an ideal way to popularize thermoelectric air-conditioning,and the waste heat utilization under its refrigeration mode has great potential in improving the comprehensive performance of thermoelectric system. |
