金属硬密封球阀粗糙接触平面的密封性能研究

Research on Sealing Performance of Rough Interface of Hard-Sealed Metal Ball Valve

以煤气化系统中锁渣阀的主密封结构为研究对象,采用不可压缩平均流动模型,建立了球面缝隙流动的泄漏量模型;提出了粗糙平面下的平均泄漏量计算方法,通过等效接触方程计算粗糙平面的接触压力,揭示了球阀表面粗糙度、表面纹理结构对阀门泄漏量的影响规律,以及阀门泄漏量与密封比压的对应关系。结果表明:在满足密封的前提下,横向纹理特征所需密封比压远小于纵向纹理特征表面;密封宽度越大,所需密封比压越小;相同泄漏量情况下,高温所需的密封比压明显大于常温时的密封比压。该研究结果对工程中球阀表面加工精度、纹理结构及密封比压的选择具有一定的参考价值。

Main sealing structure of lock hopper valve in coal gasification system served as the object of study. Incompressible average flow model was applied to establish leakage model of spherical gap flow. This paper put forward the average leakage calculation method in rough surface, calculated the contact pressure of rough surface by means of equivalent contact equation, and revealed the influence law of surface roughness and surface texture of ball valve on valve leakage and the corresponding relationship between valve leakage and sealing pressure. The results show that： under the premise of meeting sealing, the sealing pressure of transverse texture feature is far less than that of longitudinal texture feature. The larger the sealing width is, the less the sealing pressure will be. Under the same leakage condition, the sealing pressure at high temperature is significantly larger than that at room temperature. The results of the study have certain reference value for the surface machining accuracy, texture structure and sealing pressure of ball valve in engineering practice.