为了确定影响车用跨临界 CO2 空调系统性能的因素,构建了车用跨临界 CO2 空调系统的仿真模型,并利用仿真数据对系统及各部件进行了热力学分析.研究了不同的压缩机转速、气体冷却器进风风速、气体冷却器进风温度、蒸发器进风量和蒸发器进风温度对系统㶲损、㶲效率和各部件相对㶲损的影响.结果表明:在所研究的工况范围内,压缩机转速、气体冷却器进风风速和温度对系统㶲损影响较大;系统最大的㶲损来自膨胀阀,在各工况下平均占系统总㶲损的36.54％,其次分别是气体冷却器、压缩机和蒸发器,分别占系统总㶲损的24.24％、20.47％和18.81％;系统的总㶲损随压缩机转速增加和气体冷却器进风温度升高而增大,随气体冷却器进风风速增加和蒸发器进风温度升高而减小,随蒸发器进风风速的增加先减后增;系统的㶲效率随压缩机转速增加和蒸发器进风温度升高而降低,随气体冷却器进风风速增加和风温的升高而升高,随蒸发器进风风速先增后减.
Exergy Analysis of Trans-Critical CO2 Air Conditioning System for Vehicle
To determine the factors affecting the performance of the vehicular trans-critical CO2 air-conditioning system,the simulation model of trans-critical CO2 air-conditioning system for vehicle is established,and the thermodynamic analysis of the system and its components is carried out by using the simulation data.This paper studies the effects of variable compressor speed,air inlet speed of gas cooler,air inlet temperature of gas cooler,air inlet volume of evaporator,and air inlet temperature of evaporator on exergy loss and efficiency of the system and relative loss of each component.The results show that the compressor's rotating speed,air inlet velocity and temperature greatly influence the system's exergy loss.The maximum exergy loss of the system comes from the expansion valve,which accounts for 36.54％of the total exergy loss of the system on average under each working condition,followed by the gas cooler,compressor,and evaporator,which accounts for 24.24％,20.47％and 18.81％of the total exergy loss of the system respectively.The total exergy loss of the system increases with the increase of the compressor speed and the air inlet temperature of the gas cooler,decreases with the increase of the air inlet velocity of the gas cooler and the air inlet temperature of the evaporator,decreases first and then increases with the increase of the inlet air speed of the evaporator.The exergy efficiency of the system decreases with the increase of the compressor speed and the inlet air temperature of the evaporator,and increases with the increase of the inlet air speed and temperature of the gas cooler,and increases first and then decreases with the inlet air speed of the evaporator.
trans-critical CO2air conditioning for vehicleexergy lossexergy efficiency
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