| The application of spiral groove dry gas seal(S-DGS)tends to more and more extensive for its advantages of good dynamic pressure effect and strong anti-interference ability.However,in the actual operation,the seal would be invalidated due to operational errors or abnormal downtime which usually lead to the sealing ring reverse rotation.Bi-Directional rotation dry gas seal can fully solve thwas problem.At present,although many researches on the characterwastics of Bi-Directional rotation seal dry gas seal have been carried out and some progress had been made,but the opening force was still insufficient under the condition of low-speed.In order to obtain better characterwastics of Bi-Directional rotation dry gas seal,based on dry gas sealing technology and bionics principle,a new type of bidirectional rotary dry gas seal groove had been proposed and its sealing performance have been studied.The main researches of thwas paper are as follows:The flow field of imitation maple leaf dry gas seal had been investigated by Fluent software,the influence of gas film thickness and operating condition on the performance of the seal have been analyzed.The results showeded that the imitation maple leaf dry gas seal possess a better dynamic pressure effect while the film thickness ho was 2.03?m,3.05?m and 5.08?m respectively.The dynamic pressure effect would be weakened with the increase of the film thickness at the same groove depth.while the film thickness ho was 2.03?m,the opening force and the leakage rate would be improved with the operation pressure increasing.And the increase degree of opening force was greater than that of leakage rate.while the groove depth was larger than 1 1?m,compared with the spiral groove dry gas seal,imitation maple leaf dry gas seal had a larger opening force;while the groove depth was 5?m and the film thickness between 3 and 5?m,imitation maple leaf dry gas seal possess a better anti-interference ability compared with the spiral groove dry gas seal.The effect of real gas effect on the performance of spiral groove,groove bottom inclined spiral groove and imitation maple leaf dry gas seal have been numerically analyzed by Fluent.The results showed that the groove bottom tilt had a greater axial stiffness compared to the ordinary spiral groove.The real gas effect had a great influence on the leakage rate of the dry gas seal while the medium gas was air,while it had a little effect on the opening force.The results of air and nitrogen in the ideal gas state are close to those of real gas.Since the hydrogen was more difficult to compress than air and nitrogen,the results of the hydrogen real gas are smaller than those of ideal gas.The real gas effect did not have much effect on the tank temperature.The temperature of the gas near the outer edge of the imitation maple leaf was low,and while the film thickness increases,the high temperature zone of the film was gradually transferred from the zone to the dam area.The larger the film thickness,the lower the average temperature of the end film.It was assumed that the static ring deformation was axwasymmetric and linear.Based on the formula of the Picchen ring,the deformation of stator had been analytically calculated by coupling the membrane pressure and the static ring deformation.The results showed that the smaller the sealing gap was,the greater the ring deformation would be.The numerical simulation of fluid-solid coupling of imitation maple leaf dry gas seal was carried out by using ANSYS Workbench platform,Fluent and Mechanical softwares.The results of numerical simulation were compared with the results of analytical calculation.The results showed that the difference between the two method's result was small and the maximum deformation of the static ring occurs mainly in the static ring outside diameter. |
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