| In view of the lubrication occasions at high speed, the gas-liquid two-phases lubrication became the promising way of lubrication due to its high efficiency, accuracy and economy. The seal used now existed these problems of large leakedge, poor application and low reliability, restricting the development of two-phase lubrication. the gas-liquid two-phases hydrodynamic seal is presented in this paper. Fristly, according to the liquid-gas ratio, the low liquid-gas ratio hydrodynamic seal and the high liquid-gas ratio hydrodynamic seal was divided. And then the flow field distribution of the seal face was analyzed both the low liquid-gas ratio hydrodynamic seal and the high liquid-gas ratio hydrodynamic seal. According to different of liquid-gas ratio working condition, the flow field distribution of the seal face, the gas-liquid two-phase hydrodynamic seal performance, optimization of structural parameters, variable pressure difference operation and start up performance were reserched systemly and deeply.Dring the low liquid-gas ratio hydrodynamic seal study, assume that the small liquid droplets distributed in the gas uniformly, the equivalence viscosity and density expressions was deduced and the gas-liquid pressure control equation was built. A finite element program was compiled by MATLAB to solve the gas-liquid pressure control equation to obtain pressure distrubution and sealing performance parameters in the actual work condition. The flow of the the low liquid-gas ratio hydrodynamic seal was analyzed by the DPM model of the FLUENT. The rationality of gas-liquid two phase pressure control equation and the correctness of the MATLAB program to solve the control equations were verified.The influence of operating parameters on the sealing performances were analyzed by the method of finite element programs by MATLAB to solve the gas-liquid pressure control equation. And using orthogonal experiment method, the influence of seal performance related to the structural parameters of spiral groove was comprehensively analyzed and comprehensive multi-parameter optimization results were obtained. The performance were analyzed under the differential pressure (-0.02MPa-0.05MPa) the running conditions and The starting up process was studied. The results showed that within the scope of the variable pressure difference, the seal was able to maintain the opening and closing force of dynamic balance, and the woking thickness were within the appropriate scope.The flow of the the high liquid-gas ratio hydrodynamic seal was analyzed by the MIXTURE model of the FLUENT softwere. Seal face clearance model was established and the clearance flow field distribution was obtained. The two kinds of outside diameter slot and the inner diameter slot structure were comparatively researched. The outside diameter slot was chosen considering high fluid film stiffness and opening force. The inner diameter slot was chosen considering low leakadge and friction torque. The operation parameters and structure parameters on the influence of sealing performance were studied. the performance were analyzed under the differential pressure (-0.02MPa～0.05MPa) the running conditions. The results showed that within the scope of the variable pressure difference, The seals was able to maintain the opening and closing force of dynamic balance, and the woking thickness were within the appropriate scope. The starting up process shows that the outside diameter slot structure was easily opened the hydrodynamic seal.The high speed gas-liquid two-phase hydrodynamic seal test system was ablished and the design and installation rationality of the gas-liquid hydrodynamic seal was verified. The static test and hydrodynamic test were complished. Good sealing effect and performance of the high speed gas-liquid two-phase seal were presented in actual working condition. At the same time, based on the test results, the validity of the numerical analysis was verified compared with the conclusion of numerical analysis.Through sealing performance analysis and test research, the feasibility of high speed gas-liquid two-phase hydrodynamic seal was verified. The study laid a solid foundation application of gas liquid two phase lubrication and development. The engineering application field of hydrodynamic seal was broaden. The Gas-iquid two-phase flow theory for the micro clearance was abundanted. |
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