补气增焓系统中补气量控制方式的应用分析

Application analysis on injecting vapor flow control methods to system of increasing enthalpy by vapor injection

补气增焓系统在低温热泵领域得到越来越广泛的应用,在补气增焓技术的实际应用中,如何控制补气量是系统高效运行的关键。本文结合市场上产品应用现状,对使用电子膨胀阀同时控制排气温度和补气过热度、热力膨胀阀控制排气过热度及电磁阀控制排气温度这3种常用的补气量控制方式的优缺点及使用成本进行对比分析,并进一步通过试验定量地研究其应用效果。结果表明:以补气过热度为控制目标的系统制冷能力最高,高于其他方式10%以上。

The system of increasing enthalpy by vapor injection is applied to the lowtemperature heat pump field more and more widely.In the application of increasing enthalpy by vapor injection technology,how to control injecting vapor flow is the key to make system operate efficiently.Combined with products' application situation,the advantages,shortcomings and use cost of three common control methods of injecting vapor flow are analyzed comparatively,including controlling simultaneously discharge temperature and economizer's superheat degree using electronic expansion valve,controlling discharge superheat degree using thermostatic expansion valve and controlling discharge temperature using electromagnetic valve.Furthermore,the experimental study on the application effects is carried out.The results show that the system's cooling capacity with the control method of economizer's superheat degree is the largest,which is larger than the other two methods by over 10%.