Abstract:Steamlubricated dry gas seal is a special kind of dry gas seal,and the lubricating gas is steam.To study the performance of steamlubricated dry gas seals,the infinitegroove theory was used,and the RK equation was used to express the actual gas behavior of water vapor.The gas film pressure control equation of the spiral groove was modified to analyze the opening force,gas film stiffness,leakage rate,film friction torque and thermal equilibrium film thickness of the vaporlubricated dry gas seal.The results show that the leakage rate is first decreased and then increased with the increasing of film thickness at low pressure,and is increased with the increasing of film thickness at medium and high pressure.The actual gas behavior has much influence on the leakage rate.The friction moment is decreased with the increasing of film thickness,and the actual gas behavior has no influence on the friction moment.When the temperature is 300 ℃,and the pressure is 0.5 MPa,within the scope of the common working film thickness,the shear heating rate is always greater than the expansion heat absorption rate,and the heat balance film thickness cannot been obtained.When the pressure is 2 MPa and 5 MPa,the heat equilibrium film thickness of the actual gas is less than that of the ideal gas,and the difference between them is 0.886% and 2.932%,respectively.
