往复压缩机气量调节系统气阀瞬态特性的研究

基于主动控制进气阀的气量调节系统具有调节范围大、节能效果好等优点,适用于工艺流程中大型压缩机。本文依据热、动力学理论建立了耦合阀片运动的往复压缩机热力学模型,模拟了气缸内气体瞬态压力变化规律及进气阀片运动特性。研究结果表明:调节工况下自动阀和强制阀方式同时存在,执行机构延迟关闭进气阀,使压力升高过程延迟,实现压缩机流量及功率的降低。执行机构在气阀完全打开后作用,不影响气阀打开过程,仅利用撤销时间控制压缩机气量。调节工况下阀片打开速度不变,但关闭速度增大,且阀片与阀座间的最大撞击速度随执行机构撤销角度的增大而增大。由于气阀打开及关闭存在时间延迟,执行机构撤销时间在主轴转角为160°~295°范围内变化时,已实现气量0~100%范围调节。

Study on Dynamic Process of Suction Valve in Reciprocating Compressor with Capacity Regulation System

Capacity regulation system based on controlling suction valve is suitable for large scale reciprocating compressor in industrial process due to its large regulation range and energy-saving. In this paper,a thermodynamic model coupled with the motion of suction valve is built,and the dynamic gas pressure in cylinder and the motion of valve plate are simulated. The results show that the automatic and controlled suction valves are existed in an adjustment cycle. Because the actuator preventing the suction valve from closing in order to delay the compressing process,the capacity and power of compressor decrease at the same time.The actuator only influences the closing process of suction valve because it motions after the valve is opened. The opening speed is constant but the closing speed is increased in the regulation condition,and the maximum impact speed is increased with the relax angle of actuator. The capacity of 0 ~ 100% can be adjusted when the actuator relaxs at the axis angle of 160° ~ 293° due to the motion time of vave plate.