内检测器调速旁通阀流场特性仿真

旁通阀是内检测器实现速度控制的关键部件,其直接决定内检测器的运行安全及检测精度。为实现旁通阀结构最优化,进而制定合理的速度调节策略,本文通过数值模拟的方法研究了流体介质通过不同结构旁通阀时所具有的流场特性。仿真结果表明：当流体介质通过厚孔式旁通阀时,旁通孔前后压差、压力损失系数与泄流面积均成反比,且与理论计算值趋势一致且误差逐渐递减；当流体介质通过厚孔圆盘式旁通阀时,旁通孔前后压差与泄流面积成反比,而压力损失系数与泄流面积成正比；当流体介质通过转动式旁通阀时,旁通泄流尺寸越大,前后压差和压力损失系数均减小,与厚孔式旁通阀规律一致。可见,旁通阀前后压差与泄流面积呈绝对反比关系,而压力损失系数不仅受泄流面积影响,还与旁通阀自身结构有关。

Simulation of flow characteristics of internal detector bypass valve

Simulation of flow field characteristics of internal detector speed regulating bypass valve is a key component of internal detector speed control, which directly determines the operation safety and detection accuracy of internal detector. In order to optimize the structure of by-pass valves and develop a reasonable velocity regulation strategy, the flow field characteristics of fluid passing through different structures of by-pass valves are studied by numerical simulation. The simulation results show that when the fluid passes through the thick hole bypass valve, the pressure difference before and after the bypass valve, the pressure loss coefficient and the discharge area are all inversely proportional, and the trend is consistent with the theoretical calculation value and the error decreases gradually. When the fluid passes through the thick hole disc bypass valve, the pressure difference before and after the bypass hole is inversely proportional to the discharge area, while the pressure loss coefficient is proportional to the discharge area. When the fluid passes through the rotary bypass valve, the larger the size of bypass discharge, the lower the pressure difference and pressure loss coefficient, which is consistent with the rule of the thick hole bypass valve. It can be seen that the pressure difference before and after the bypass valve is inversely proportional to the discharge area, and the pressure loss coefficient is not only affected by the discharge area, but also related to the structure of the bypass valve.