太阳能增效的复叠式空气源热泵系统能量分析与及(火用)分析

Energy Analysis and Exergy Analysis of Solar Energy Enhanced Cascade Air-Source Heat Pump System

为了提高空气源热泵的效率和稳定性,提出一种太阳能增效的复叠式空气源热泵系统,建立系统的能量模型和(火用)模型,以R134a为制冷剂进行计算分析.结果表明:随着中间冷凝温度的升高,系统机械性能系数先增大后减小,当中间冷凝温度为38℃时,系统机械性能系数达到最优值;随着中间冷凝温度的升高,(火用)效率先增大后减小,当中间冷凝温度为22℃时,(火用)效率达到最优值;系统机械性能系数、制热量、(火用)损失随着蒸发温度的升高而增大;随着太阳辐射照度的增大,系统机械性能系数、(火用)效率及制热量均有明显提升;系统中(火用)损失最大的部件为集热发生器,提高集热效率、采用合理的运行参数是提高系统(火用)效率的关键.

In order to improve the efficiency and stability of the air-source heat pump,a solar energy enhanced cascade air-source heat pump system is proposed,the energy model and exergy model of the system are established,and R134 a is used as the cryogen for calculation and analysis.The results show that with the increase of the intermediate condensation temperature,the system mechanical performance coefficient first increases and then decreases,when the intermediate condensation temperature is 38℃,the system mechanical performance coefficient reaches the optimal value.With the increase of intermediate condensation temperature,the exergy efficiency first increases and then decreases,when the intermediate condensation temperature is 22℃,the exergy efficiency reaches the optimal value.The system mechanical performance coefficient,heating capacity and exergy destruction increase with the increase of evaporation temperature.With the increase of solar irradiance,the system mechanical performance coefficient,exergy efficiency and heating capacity of the system are significantly improved.The most exergy destruction component in the system is the heat collector,improving the heat collection efficiency and adopting reasonable operating parameters are the key to improve the exergy efficiency of the system.