水-水燃气机热泵是一个复杂的过程对象,具有多变量、非线性、强耦合和时滞性的特点,如果通过机理建模法得到动态模型比较复杂,也不容易实现,且模型的精度也较低。因此,为了提高水-水燃气机热泵控制系统的仿真精度,本文实验测取了系统输出的阶跃响应曲线,采用阶跃响应曲线法建立燃气机热泵的过程模型,并对所建立的模型进行精度校验,模型精度达到工程设计要求。根据所建立的系统动态模型,利用模糊-PID控制器对系统进行仿真。仿真结果表明,采用模糊-PID控制算法能较好地实现对蒸发器平均出水温度和冷凝器出水温度的控制。
Water-Water Gas Engine Driven Heat Pump (WWGEHP) is complex process model, which has characteristics of multi-variable, nonlinear, strong-coupling and time lag. Establishing dynamic model by mechanism modeling is complicated, and it is difficult to realize and has low accuracy. In order to improve simulation accuracy of WWGEHP, step responses of system is measured; system dynamic model of WWGEHP is established by step response curve method; accuracy of dynamic model that has established is verification; and model accuracy satisfies engineering design demands. On the base of system dynamic model that has established, fuzzy PID controller is adopted in WWGEHP, and the simulation results show fuzzy PID arithmetic realizes well to control average outlet water temperature of evaporator and outlet water temperature of condenser.