经济器补气压力对双螺杆制冷压缩机性能影响的试验研究

在制冷系统中使用经济器提高了系统制冷量，但由于中间补气使压缩机耗功增加，制冷系统的COP并不会随制冷量成正比增长，其增长幅度依赖于补气压力、补气孔口位置等参数。通过实测补气工况下双螺杆制冷压缩机的P—V图，分析了不同补气压力下压缩机的热力过程特征，研究了补气压力对双螺杆制冷压缩机性能及COP的影响。研究结果表明：压缩机工作腔内气体压力在开始补气时会大幅上升，随后上升幅度逐渐变缓甚至略有下降，压缩机效率和系统COP随补气压力的上升出现先升后降的趋势，结果，存在一个最佳补气压力使制冷系统的COP增加幅度最大。

Experimental study on effects of superfeed pressure of economizer on twin-screw refrigeration compressor performance

The capacity of the refrigeration system could be increased by using the economizer, but the COP would not be improved equally due to the increased compressor power consumption from super feeding, and the improvement of COP depends mainly upon the parameters such as superfeed pressure, superfeed port location. In this study, the thermodynamic processes of the twin-screw refrigeration compressor at different superfeed pressures were investigated by analyzing the indication diagrams recorded in the twin-screw refrigeration compressor with an economizer, and the influence of the super-feed pressure on the compressor efficiency and system COP was obtained. The results show that the gas pressure in working chamber experiences a rapid increase as super-feed gas enters the chamber, and then a slow rise, and finally the pressure has a slight drop at the late phase of the super-feeding process. Correspondingly, the compressor efficiency and COP rise first and then drop, depending upon the superfeed pressure. As a result, there is an optimum superfeed pressure under which the system COP reaches the best.