升降式止回阀动态特性分析与改进

Analysis and Improvement of Dynamic Characteristics of Lift Check Valves

针对升降式止回阀不能回落至正常位置的问题,用PumpLinx软件对开启和回落过程进行非定常流动的数值模拟,并对阀体结构进行改进设计,获得原型和改进型止回阀的动态响应和内部流场分布.结果表明:与原型止回阀相比,改进型止回阀在动态开启和小间隙回落时间显著缩短,均减少了50%以上.改进型止回阀增开的4个导流槽在动态开启时能及时将阀芯受挤压流体排出,在回落时能及时进行流体补充,从而使其所受流体力较小且脉动性有所降低,流速振荡减弱,阀芯在动态过程中不易发生偏斜.该改进型止回阀能使流动稳定性有所改善,有效解决止回阀不能正常回落的问题.

Aimed at the problem that lift check valves cannot fall back to the normal position, the dynamic simulation of unsteady flow in the process of opening and falling back are conducted by using PumpLinx, and the structure of the valve body is proposed and improved. The dynamic response and internal flow field distribution of the prototype and the improved check valves are obtained. The results show that the dynamic opening time and small gap falling time of the improved check valve are significantly reduced by more than 50% compared with those of the prototype. The four additional guide grooves of the improved check valve can promptly discharge the squeezed fluid from the valve core during dynamic opening, and can promptly supplement the fluid when it falls back, so that the fluid force, the pulsation, and the velocity oscillation are weakened, which can make the valve core stable without easy deflection in the dynamic process. Therefore, the check valve proposed can improve the flow stability and solve the problem that the check valve cannot fall back normally.