Numerical And Experimental Study On The Aerodynamic Operating Characteristics And Prediction Model Of Dry Gas Seal

Dry gas seal is a kind of non-contact mechanical seal using gas as a sealing medium,which has lower leakage,less wear and lower energy consumption and other advantages.It has solved the problem that mechanical seal has been unable to dry running over the years,and been widely used in the field of petroleum,chemical and metallurgy.In this paper,the aerodynamic characteristics of the spiral groove dry gas seal were studied.The numerical calculation method was used to calculate the classic example of Gabriel,and the numerical results were compared with the Gabriel's results.The results are in good agreement and verify the feasibility of the CFD numerical method.Taking the Gabriel example as the research object,the influence of the working conditions and the thickness of the film on its aerodynamic characteristics were studied.Then,the numerical results were numerically fitted to establish the aerodynamic prediction model which using operating parameters(inlet pressure and rotational speed)and film thickness as independent variables.In addition,numerical fitting method was applied to an actual sealing product to determine the aerodynamic prediction model.Then,the characteristic parameters of other operating conditions were calculated by using the prediction model.The results indicates that the leakage calculation values of prediction model are in good agreement with the measured data.The reliability of the numerical method and the prediction model was further verified.The influence of groove structure parameters on the aerodynamic characteristics of spiral groove dry gas seal was studied,and the response surface model and variance analysis were introduced to analyze the main effect and interaction effect of groove parameters on aerodynamic characteristics qualitatively and quantitatively.The numerical simulation of the bi-direction dovetail groove dry gas seal was carried out.The influence of the operating conditions and the thickness of the film on its aerodynamic characteristics was studied.The aerodynamic prediction model was determined by fitting the numerical results.Furthermore,the aerodynamic characteristics of spiral groove and bi-directional dovetail groove were compared and analyzed.In this paper,the aerodynamic performance of dry gas seal under different working conditions,film thickness and groove structure parameters was studied,and the prediction model of aerodynamic performance of dry gas seal was obtained.The influence of working condition parameters and groove structure parameters on dry gas sealing performance was clarified.The results provides a quick and accurate method for the aerodynamic prediction and it is instructive to optimize the dry gas seal groove.