适用于制冷系统动态仿真的全封闭式压缩机准动态模型

Quasi-dynamic Hermetical Compressor Model Suitable for Dynamic Simulation of Refrigeration System

制冷系统动态仿真中要求压缩机模型能够适用于吸入制冷剂状态从两相到气相的宽变化范围,并且能够快速地反映其关键的动态特性,为了解决这个问题,提出了可覆盖进口状态从气相到两相制冷剂的准动态压缩机模型。此模型按其热力过程分解为吸入气相或两相制冷剂与腔内制冷剂混合过程的动态模型、壳体换热过程的动态模型和气缸内制冷剂压缩过程的稳态模型。此压缩机模型克服了通常压缩机模型中忽略腔内制冷剂混合过程所导致预测的流量大于实际流量的缺点,以及全部采用动态模型导致计算复杂的问题。通过某压缩机厂生产的全封闭式压缩机的稳态实验数据和模型预测值的比较,结果表明:模型预测的稳定工况时的质量流量和输入功率与实验数据误差小于5%;开机过程质量流量和输入功率与实验测量值趋势一致,误差小于10%。

The compressor model used in the dynamic simulation of refrigeration system should not only be applicable in the case that the state of the sucked refrigerant varies in a wide range of vapor to two-phase,and also be quick enough in predicting the major dynamic characteristics of the compressor.In order to meet these requirements,a quasi-dynamic hermetic compressor model covering the suction state from vapor to two-phase was presented in this paper.According to its thermodynamic process,the compressor model includes,a dynamic model for the mixing process of refrigerant inside compressor and sucked two-phase or vapor refrigerant,a dynamic model for the compressor shell heat transfer model,and a steady state model for the polytropic compression.The compressor model overcomes the flaw of unreasonable mass flow of the existing models caused by neglecting the mixing process of refrigerant inside of compressor.The maximum differences of steady state mass flow rate and input power of a hermetic compressor between the experimental data and the predicted results are less than 5%,while the deviations of the predicted transient mass flow rate and input power from the experimental data are within 10%.