高速动压密封的气液两相性能对比分析和试验

Comparative analysis and experiment on gas-phase and liquid-phase performance of high-speed hydrodynamic seal

摘要:

为明确气相介质和液相介质分别对高速流体动压密封性能的影响,进行两种相态的密封性能对比分析与试验研究. 分别建立动压密封端面流体域的气相和液相数值分析模型,分析转速、压差、槽深、槽数、槽坝比等操作参数和端面结构参数对动压密封气相和液相的泄漏量、开启力等性能的影响. 自主研制动压密封试验装置,进行变转速、变压差和密封端面磨损试验,得出了转速、压差等操作参数对密封气相泄漏率、液相泄漏率和端面磨损率的影响. 数值模拟和试验研究结果表明:相同的转速和压力时,液相密封开启力和泄漏量都比气相密封更大；不同结构参数下,气相和液相密封开启力均有极大值,气相密封和液相密封开启力达到极大值的最优结构参数有所不同,液相密封的最优槽坝比、最优槽数较气相密封小,液相密封开启转速较气相密封低,说明液相动压密封比气相动压密封更容易开启；低速时密封端面磨损较严重,高速时密封端面几乎无磨损,动压密封更适合在高速工况下运行.

Abstract:

To clarify the effects of gas and liquid media on the performance of high-speed hydrodynamic seal, the comparison analysis and experimental research on the sealing performance of two phases were carried out. The numerical analysis models of gas and liquid phases in the end face fluid region of hydrodynamic seal were established. The effects of operating parameters such as rotational speed, pressure difference, groove depth, groove number, groove-dam ratio and end face structure parameters on gas and liquid leakage and opening force of hydrodynamic seal were analyzed. The test device of hydrodynamic seal was developed independently, and the tests of variable speed, pressure difference and seal face wear were carried out. The effects of operating parameters such as speed and pressure difference on gas leakage rate, liquid leakage rate and seal face wear rate were obtained. The results of numerical simulation and experiment show that the opening force and leakage of liquid seal are larger than those of gas seal at the same speed and pressure. Under different structural parameters, the opening forces of gas phase and liquid phase seal have maximum values. The optimal structural parameters are different for the gas and liquid phase seal when the opening forces reach maximum values. The optimum ratio of slot to dam and the number of optimal grooves in liquid phase seal are smaller than that in gas seal. The opening speed of liquid seal is lower than those of gas seal, indicating that liquid dynamic pressure seal is easier to open than gas dynamic pressure seal. Seal face wear is serious at low speed and almost no wear at high speed. Hydrodynamic seals are more suitable for high speed conditions.