端面锥形参数对锥-孔组合型机械密封性能的影响  

Effect of tapered face parameters on performance of cone-pore-combined mechanical seal

作　　者：程香平[1] 孟祥铠[2] 彭旭东[2] 张友亮[1] 付远[1] 康林萍[1] 

机构地区：[1]江西省科学院应用物理研究所,江西南昌330029 [2]浙江工业大学过程装备及其再制造教育部工程研究中心,浙江杭州310032

出　　处：《化工学报》2016年第11期4762-4770,共9页CIESC Journal

基　　金：国家自然科学基金青年项目(51505203);国家自然科学基金面上项目(51375449);江西省科技开发和产业化开发项目(20151BBE51065);2015年江西省科学院博士启动基金项目(2014-YYB-18;2014-XTPH1-18)~~

摘　　要：给出新型锥-孔组合型端面密封,考虑液膜压场的变化规律与环受力变形的相互作用关系,构建机械密封3D流、固耦合数学模型,并给出相关的数值计算方法,获得了膜压分布规律及端面变形情况,分析锥面结构参数在各工况下对密封性能的影响规律。结果表明：由菱形孔所引起的动压效应可使端面产生周向和径向波状变形,而静压效应随锥度Ф和锥宽比γ的变化,在端面区域范围内所起作用也发生相应变化;对压强较低和低、中转速设备,应选取Ф=5～6或Ф=2～4的收敛锥面密封,且γ=0.8～1.0。对高压和高速设备,应选用Ф=2～3的收敛锥面密封,且γ=1.0或γ=0.2;通过改变锥面结构可有效改变机械密封的特性参数,实现密封运行中的自动调节,特别适合变工况条件。另外,由于锥面结构的变化所引起平衡系数B和膜厚h的变化,低速时可弥补动压效应较小的缺陷,获得较大开启力,也可在大h下工作,故可降低密封端面对平整度和光洁度的要求。A three-dimensional fluid-solid coupling mathematic model of a cone-pore-combined mechanical seal was established by considering interactions of pressure distribution change of fluid film between two end faces and stress deformation of sealing rings. A numerical iteration method was developed to solve the coupling model so as to obtain pressure distribution of the fluid film and surface deformation. The influence of structural parameters of the tapered end face on sealing performance was analyzed at various working conditions. The results showed that diamond-shaped pores created dynamic pressure effect, which produced circular and radial wave deformation at the end faces, and static pressure effect, which changed impact accordingly within the end face region with the increase of taper Ф and cone width ratio γ. The convergent seal of the tapered end face at Ф=5—6 or Ф=2—4 and γ=0.8—1.0 should be selected for low pressure and low to medium speed equipment. The convergent seal of the cone end face at Ф=2—3 and γ=1.0 or γ=0.2 should be selected for high pressure and high speed equipment. Changing tapered end face structure could effectively modify characteristic parameters of the cone-hole combined mechanical seal and automatically adjust seal performance during operation, which is especially suitable for variable work conditions. In addition, the change of balance coefficient B and film thickness h caused by structure change of the tapered end face could made up defects of small dynamic pressure effect at low speed to achieve large opening force and could also work under large h so that the flatness and polish requirement for seal end face might be reduced.

关 键 词：数值模拟 流体动力学 端面变形 层流 

分 类 号：TU831.3[建筑科学—供热、供燃气、通风及空调工程]