Research On Vibration Characteristics And Thermal Deformation Of Hydrostatic Dry Gas Seal

Research of mechanical seal technology is one of the focuses of domestic scientific research topics recent years, which involves engineering mechanics, fluid dynamics, tribology, heat transfer, fluid lubrication theory and other disciplines. Currently mechanical seal technology is relatively mature abroad, while domestic research still remain in the field of mechanical seal principle, structure, the sealing flow field simulation and seal rings thermal analysis, but the study results on the dynamic characteristics of the mechanical seal rings is relatively small. Mechanical seal system will be inevitably by its own or the external factors in the stable operation of the process such as seal face wear, leakage, sealing face medium cavitation effect, and it will lead to the axial vibration and coupled vibration which will accelerate the leakage, reduce the service life, and even make the sealing device failure. This paper selects static pressure dry gas seal of the mechanical seal systems, analyses and studies closely on sealing principle and structure, the seal faces pressure distribution, the dynamic characteristics and thermal stress deformation.(1) Introduce the principle and structure of the static pressure dry gas seal; Analysis the forces of the seal faces, derive the Reynolds equation solving seal face pressure distribution, and describe related parameters; Finally the orifice flow and the calculation formula of leakage is derived.(2) Describe the solution process of the pressure distribution on external static pressure dry gas seal sealing end faces in detail by studying and using the fluid analysis CFD module of the finite element software ANSYS, and solve the pressure distribution on sealing end surfaces of different thickness dielectric films by ANSYS software. Pressure on the seal faces within the groove for only a slight change can be almost ignored in constant outer pressurized conditions; Analysis the curve of pressure change with the thickness of the dielectric film on a particular node, and derive the fitting polynomial equation of the change of the pressure and film thickness by fitting the curve of pressure with the dielectric film thickness on the node through the application of data processing software MATLAB.(3) Establish and solve stationary ring axial vibration and coupled vibration analysis models of a system for static pressure dry gas seal. With the help of the rotating coordinate system, considering the impact of various parameters on the dynamic nature of law in the process of stable operation, analysis detailed and derivation simplify the conclusion that the dynamic characteristic equation solving for the law of motion. Solve and draw its law of motion through the MATLAB software.(4) Analysis dynamic and static rings of static pressure dry gas seal from the overall of temperature field by using thermal analysis module of ANSYS software and draw overall temperature distribution law. At the same time, obtain the thermal stress and deformation law under specific constraints by the conversion unit type and loading the temperature field solution results.This paper studied the pressure distribution, dynamic characteristics of the axial vibration and coupled vibration, and thermal stress deformation on the dynamic and stationary rings of the dry gas seal system in static pressure, which provides the certain reference for the research of mechanical seal system.