一种过冷器耦合的准二级压缩热泵系统特性分析及优化

Analysis and optimization on coupling sub-cooler vapor injection air source heat pump system

提出了一种过冷器耦合的准二级压缩空气源热泵系统,该系统由两个三套管换热器将两个带过冷器的准二级压缩热泵系统耦合成一个系统,其除霜方式为基于热气旁通除霜的系统耦合除霜,解决了热气旁通除霜时室外换热器产生液态制冷剂的蒸发问题,提高了空气源热泵在低温高湿环境下运行的性能;对新系统正常制热工况进行仿真优化,找出低温工况的最佳中间温度及相应补气系数;对最佳中间温度进行关于冷凝温度和蒸发温度二元线性拟合并得到经验拟合公式。

A coupling sub-cooler vapor injection air source heat pump system is proposed,which consists of two sub-cooler vapor injection air source heat pumps and two triple tube heat exchangers.The defrost method involves a coupling defrost system based on traditional hot gas bypass defrost,so that the problem of liquid refrigerant evaporation is solved,which is usually encountered in the outdoor heat exchanger with traditional hot gas bypass defrost.The operation reliability of air source heat pump is improved in the environment of low temperature and high humidity.The simulation and optimization for the new system under normal heating conditions give the optimal medium temperatures and corresponding injection ratios in low temperature environment.A binary linear fitting formula for optimal medium temperatures from condensing temperature and evaporating temperature is obtained.