Study On End Face Structure And Characteristics Of Mechanical Seal With Spiral Wave Face

With the increasing shortage of non-renewable energy in the world,the development of nuclear power is a major choice for every country.Nuclear main pump mechanical seal is a very important part of nuclear power equipment.In this paper,a new type of mechanical seal with spiral surface is proposed,which is applied to the mechanical seal of the nuclear main pump as the research object.First of all,the mathematical model of mechanical seal with spiral surface is established,and the influence of various structural parameters on the model is analyzed.Secondly,based on the mathematical model,the Reynolds equation is solved by the finite difference method,and then the theoretical model of the characteristic of the lubrication film between the seal faces is established.Again,the computation program is programmed by MATLAB software,seal between the end surfaces of the liquid film pressure distribution is obtained,and then obtained the opening force,leakage,liquid stiffness and ratio of stiffness to leakage.finally,research the influence of mechanical seal structure parameters and operating parameters on the opening force,leakage,liquid stiffness and of ratio of stiffness to leakage,and it is concluded the relevant rules.The research reveals the working mechanism of the mechanical seal,and provides a theoretical basis for the design and research of mechanical seal in the future.The research analysis indicates that:(1)When the film thickness is 1-3μm,the leakage could be ensured to meet the requirements,and at the same time,the ratio of stiffness to leakage,the liquid film stiffness and the opening force have a greater value.Therefore,the best value range of the liquid film thickness is 1-3μm,the priority value is 2μm.(2)When the wave amplitude is 2-6μm,the leakage could be ensured to meet the requirements,and at the same time,the ratio of stiffness to leakage,the liquid film stiffness and the opening force have a greater value,and the liquid film stiffness reaches a peak value when the wave amplitude is 4μm.Therefore,the best value range of the wave amplitude is 2-6μm,the priority value is 4μm.(3)When the wave number is 6-30,the leakage could be ensured to meet the requirements,and in consideration of reducing the processing difficulty at the same time,the ratio of stiffness to leakage,the liquid film stiffness and the opening force have a greater value.Therefore,the best value range of the wave number is 6-30,the priority value is 20.(4)When the helix angle is 10-30°,the leakage could be ensured to meet the requirements,and at the same time,the ratio of stiffness to leakage,the liquid film stiffness and the opening force have a greater value,and the ratio of stiffness to leakage and the liquid film stiffness reaches a peak value when the helix angle is 18°.Therefore,the best value range of the helix angle is 10-30°,the priority value is 18°.(5)When the dam width ratio is 0.3-0.6,the leakage could be ensured to meet the requirements,and at the same time,the ratio of stiffness to leakage,the liquid film stiffness and the opening force have a greater value.Therefore,the best value range of the dam width ratio is 0.3-0.6,the priority value is 0.4.