往复压缩机流量无级调节系统动态特性研究

Dynnamic Performance of Reciprocating Compressor with Capacity Stepless Regulation System

基于主动控制吸气阀原理的流量调节系统具备调节范围宽、速度快、稳定可靠等优点,在大型工艺往复压缩机中具有较大优势,调节系统动态特性是衡量调节性能的重要指标。建立了耦合控制系统、液压系统、执行机构等组件的数学模型,分析了排气储罐内气体压力、阀片位移、缸内气体压力、控制角度等特性参数的变化规律。结果表明:调节工况下阀片打开过程早于执行机构,随后共同复位,且复位过程中存在微小碰撞。利用排气储罐内气体压力间接控制压缩机排气量的方法存在调节滞后性,造成罐内压力脉动增大,低流量时更加明显。调节过程中阀片位移与缸内气体压力均具有周期性变化规律,PID参数的欠优化导致调节过程中多次出现最小控制角度,降低了调节系统的稳定性。

The capacity regualiton system based on the principle of active control suction valve is suitable to be used on the large-scale reciprocating compressors due to its large adjustment range, sensitivity, stability and reliability. The system dynamic performance is a very important index to evaluate this system performance. A mathematical model coupled with control system, hydraulic system, actuators and other components is set up, and the gas pressure in tank, valve plate displacement, gas pressure in cylinder and control angle are analyzed. The results show that the open process of valve plate is earlier than actuator but they reset together, and there is weak impact in reset process. Regulation capacity by controlling the gas pressure in tank leads to the delayed adjustment, which increases the pressure pulsation especially under low flow rate operating conditions. All the delay time of valve plate and compression process periodically change with control time. Optimazing PID parameters can reduce the times of minimum delay angle and improve the regulation stable of this system.