双并联冷凝器水冷热泵系统模拟与试验研究

运用EES编程建立了水冷热泵系统的数学模型,对系统的制热性能进行了模拟计算,主要分析了室内环境温度、冷却水进口温度和流量对系统制热量性能系数和能效比的影响。模拟结果表明:室内环境温度对系统性能系数和能效比影响很大,随着温度的升高制热系数降低;在一定范围内随着进水温度和流量的升高,系统性能系数和能效比急剧增大,但随后趋于平缓,存在最佳流量。通过模拟研究了运行参数对性能的影响,为实际的开发设计和验证提供了依据。根据理论设计,搭建试验样机,利用空调焓差室对该机组进行试验研究,对试验样机在名义工况下的制冷、制热性能进行了测试,水侧和制冷剂侧热平衡偏差在5%以内,进一步验证了测试的准确性。测试结果表明,制冷工况时的性能系数和能效比均低于制热时的,采用双并联冷凝器设计,对于较大制冷量和制热量热泵系统具有明显优势。

Simulation and Experimental Study on the Water-to-water Heat Pump with Two Parallel Condensers

The mathematical model for a heat pump system is developed by EES( Engineering Equation Solver) in this paper and the heating performance is simulated. The effect of ambient temperature,the inlet temperature of cooling water and its mass flow rate on the system heating coefficient of performance and energy efficiency ratio are analyzed. The simulation results show that the ambient temperature has a great influence on coefficient of performance and energy efficiency ratio. With the increase of ambient temperature,the heating coefficient of performance decreased. Both the heating coefficient of performance and energy efficiency ratio increased sharply in some range with the increase of inlet water temperature and its mass flow rate,but then flatten out. There exists an optimum flow rate. The influence of operation parameters on the performance are studied and provide the basis for theoretical design. According to the theoretical design,an experimental prototype are set up and studied under nominal working conditions of cooling and heating performance test. Water side and refrigerant heat balance deviation is within 5% and further verified the accuracy of the test. The experimental results show that both the cooling coefficient of performance and energy efficiency ratio are lower than the heating mode,and the design of double parallel condenser has an advantage on heat pump system.