制冷压缩机排气压力计算方法研究

Research on Calculation Method for Discharge Pressure of Refrigeration Compressor

排气压力是压缩机运行可靠性的重要指标。在排气压力传感器发生故障时,基于换热器管温计算排气压力无法保证压缩机的可靠运行。本文提出并推导了一种基于压缩机系数模型的计算方法,根据吸气压力、压缩机功率及压缩机频率计算排气压力,每30 Hz一个标定频率点情况下,其理论最大误差仅为4.2%。在动态运行测试中,模型的最大误差也仅为10.8%,可以保证系统在排气压力传感器故障时稳定运行。

Discharge pressure is an important index of compressor reliability.When the discharge pressure sensor fails,the discharge pressure calculated by the heat exchanger temperature can’t guarantee the reliable operation of the compressor.In this paper,a calculation method based on the compressor coefficient model is proposed and derived.The main input parameters include the suction pressure,compressor power and compressor frequency.The theoretical analysis shows that the average error between theoretical value and calculated value is just 2.4%.In the dynamic operation test,the maximum error of the model is 10.8%,which can ensure the stable operation of the system when the discharge pressure sensor fails.