冬季工况下活塞式制冷压缩机输气量实验研究

Study on volumetric displacement of reciprocating refrigeration compressor in winter

依托冷库制冷系统性能实验台,基于不同的风冷冷凝器风机频率,对冷库降温过程中的制冷剂流量进行监测,定量分析压缩机输气量变化规律。结果表明:冬季工况下,冷库从-2~-18℃的降温过程中,压缩机输气量先较快升至某一最大值,然后再缓慢下降并趋于稳定;库温高于极值点时,冷凝器风机频率变化对输气量影响较大,提高风机频率可使输气量增大约10%;低于极值点时,则影响较小。应用SPSS软件,建立压缩机输气量与蒸发压力、冷凝压力的二次多项式回归模型,56组测试数据与预测值的相对误差均<±3%。

Based on the different frequencies of air-cooled condenser fan and refrigeration system performance test bench,the refrigerant volume flow state was monitored in the cooling process of cold storage and quantitative analysis on volumetric displacement of the compressor was conducted.The results show that while temperature of the cold storage decreases from-2 to-18℃in winter,compressor volumetric displacement first rises to a certain maximum value at a high speed,and then decreases slowly and tends to be stable.When cold storage temperature exceeds the extreme value point,the change of condenser fan frequency has a great influence on the compressor volumetric displacement.Increasing the fan frequency can raise the compressor volumetric displacement by about 10%.When the value is under the extreme point,it is less affected.Through the application of SPSS software,a quadratic polynomial regression model on compressor volumetric displacement and evaporating pressure and condensing pressure was established,which made the relative error of test data and predicted values in 56 groups be in the range of±3%.