往复式活塞压缩机中间喷液制冷系统的火用分析

Exergy Analysis of an Intermediate Spray Refrigeration System with Reciprocating Piston Compressor

通过对往复式活塞压缩机进行改造,在单级活塞压缩系统的基础上搭建了一种中间喷液冷却的准两级压缩系统并在蒸发温度为-20℃的工况下进行实验测量,根据实验数据对单级活塞压缩系统和新型中间喷液冷却活塞压缩系统的COP、火用损失和火用效率进行计算。结果表明:加入中间喷液冷却系统后,系统的COP由1.27提升至1.36,单位制冷量由155.1 kJ/kg提升至176.7 kJ/kg;单级活塞压缩系统火用损失较大的部分是压缩机和膨胀阀,分别占压缩机输入火用的16.2%和14.8%,加入中间喷液冷却系统后压缩机部分的火用损失明显降低,仅占压缩机输入火用的3.6%,冷凝器及膨胀阀的火用损比也有所下降。

Through the modification of the reciprocating piston compressor,a quasi-two-stage compression system with intermediate liquid injection was built based on the single-stage piston compression system,and the experimental measurement was carried out under the condition of evaporating temperature of-20 ℃.The COP,exergy loss and exergy efficiency of the single-stage piston compression system and the quasi-two-stage compression system with intermediate liquid injection were calculated based on experimental data.It has been found that after adding the intermediate liquid injection,the COP of the system was increased from 1.27 to 1.36,and the unit cooling capacity was increased from 155.1 kJ/kg to 176.7 kJ/kg.The main exergy loss of the single-stage piston compression system was the compressor and the expansion valve,which account for 16.2% and 14.8% of the input exergy of the compressor,respectively.After adding the intermediate liquid injection,the exergy loss of the compressor was significantly reduced,only accounting for 3.6% of the compressor input exergy,and the exergy loss ratio of the condenser and expansion valve was also decreased.