基于状态空间的制冷系统动态建模

Dynamic modeling for refrigeration system based on state-space

为了建立适用于先进控制的制冷系统模型,对单级蒸气压缩式制冷系统的各个部件建立动态方程,通过合理的简化和推导,选取合适的参数作为状态变量,建立制冷系统状态空间模型。以某制冷系统为对象,首先通过动态仿真结果与试验数据比较,修正模型中的换热关联式,然后利用修正后的动态模型模拟某复杂扰量下该制冷系统载冷液和冷却液出口温度、压缩机功率、制冷量以及COP动态响应过程。再次对比模拟结果与试验数据,结果表明,载冷液出口温度和冷却液出口温度模拟值与试验数据之间的相对平均偏差在5%以内,压缩机功率、制冷量、COP模拟值与试验数据的相对平均偏差在10%以内,模型计算结果比较准确地反映制冷系统动态过程。

In order to establish the refrigeration system model for advanced control,dynamic equations of every part of single-stage vapor compressed refrigeration system are established.Through rational simplification and deduction,chosing appropriate parameters as state variables,the state-space model of refrigeration system is established.Taking one refrigeration system as object,through the comparison of dynamic simulation results and experimental results,the heat transfer correlation of the model are revised.The revised dynamic model is used to simulate the dynamic response process of seondary refrigeration and cooling liquid＇s outlet temperature,compressor power,cooling capacity and COPfor refrigeration system under some complex disturbances.A second comparison of calculated results and experimental results shows that the relative average deviation between the simulation results and experimental results of outlet temperature of secondary refrigeration and cooling liquid is within5%,and that of compressor power,cooling capacity and COPis within 10%.The modeling results can reflect the dynamic process of refrigertion system exactly.