燃气机热泵流量控制策略研究

The Flow Control Strategy of the Gas Engine Heat Pump

针对燃气机热泵控制系统适应环境温度和系统负荷的变化,需要合适的控制策略改变电子膨胀阀的开度来调节制冷剂的流量。通过对电子膨胀阀的工作原理和控制策略的分析,利用MATLAB比较不同控制策略的控制效果得到最优的控制器参数从而确定控制系统的最优传递函数;利用西门子S7-200给出温度、过热度检测和热物理参数实时监控的PLC监控设计方案和通过触摸屏显示温度、压力、过热度等相关数据及历史变化曲线,实现燃气机热泵控制系统中蒸发器过热度的自动检测、PID控制、监控和存储;通过仿真对比了几种策略控制效果,并通过实际试验数据的采集和图像显示,表明了基于遗传算法最优PID参数整定方法确定的控制器参数的控制效果最优。

For gas engine heat pump control system to adapt to the changes of the ambient temperature and system load. It is necessavy to has appropriate control strategies to change the electronic expansion valve opening degree for adjusting the flow of refrigerant. Through the analysis of the electronic expansion valve working principle and control strategy,and the comparison of the effect of different control strategies to get the optimal controller parameters to determine the optimal control system transfer function from using MATLAB; The PLC control design scheme of temperature, superheat detection and the real time monitoring of thermal physical parameters, and via touch-screen display of temperature,pressure, superheat or other relevant data and historical curve given by using Siemens S7-200, the evaporator superheat automatic detection, PID control of the gas engine heat pump control system are achieved. The simulation results of several strategies to control effect, and through practical test data acquisition and image display, shows that the control effect determined by controller parameters based on the method of genetic algorithm optimal PID parameters tuning is optimal.