Numerical Simulation Of Dry Gas Seal Moving Ring Of Natural Gas Centrifugal Compressor

The dry gas sealing technology originated from abroad.It is to open a dynamic pressure groove on the end face of the mechanical seal moving ring and set a corresponding auxiliary sealing system to achieve non-contact sealing at the shaft end.Although the dry gas seal technology is developed from the mechanical seal technology,it has significant advantages compared to the mechanical seal.Because it is a noncontact seal,it has less wear and energy consumption and can be applied to shaft end seals for high-speed rotating equipment.Therefore,dry gas seals have developed extremely rapidly in China in recent years,especially on centrifugal compressors for petrochemical equipment.But because of the research on dry gas seal technology,most of them come from abroad,and their domestic development is still relatively backward.Therefore,the research on dry gas sealing technology has far-reaching significance for improving China's sealing technology.This article proposes a new type of spiral groove dry gas seal with connected ring groove(published patent).It is to add a communication ring groove to the spiral groove dry gas seal moving ring to connect all the dynamic pressure grooves and let each dynamic pressure The grooves communicate with each other.The combination of Fluent numerical simulation and experimental research is used to study the dry gas seal.In the part of numerical simulation research,Gambit was used to establish the geometric model,mesh division and boundary setting of the calculation basin.Finally,the model was imported into Fluent simulation software,and the model was calculated under given operating parameters.The analysis of the simulation results showed that the pressure distribution of the gas film on the end face of the spiral groove dry gas seal with connected annular grooves was found to be more uniform.Analysis of the simulation results of spiral groove dry gas seals with connected annular grooves with different geometric parameters.It is found that the width of the connected annular groove is 6mm,the weir width ratio ? is 0.6,the film thickness ho is 2?m,the groove depth hg is 4?m and the helix angle ? The sealing performance of spiral grooves with connected annular grooves at 15 ° is the best.The simulation results of the dry gas seals with connected annular grooves with different cross section grooves are analyzed.Under the circumstances,the rigidity is relatively large,and it has strong antiinterference ability.The triangular cross-section spiral groove dry gas seal has a small leakage,which is suitable for the application where the leakage is required.The trapezoidal cross-section spiral groove dry groove seal.When the gas seal is at high speed and low pressure,the leakage is relatively large,so it has better comprehensive sealing performance in high speed and low pressure conditions.The experimental study used the dry gas seal test platform of Xi'an Shiyou University,and measured the leakage and torque at a pressure of 0.2Mpa-0.5Mpa and a speed of 1500-4000 rpm.The influence of a single variable of speed and pressure on the performance of the dry gas seal is obtained.The experimental results show that changing the speed and pressure alone will cause an increase in leakage and power,which is consistent with the simulation results,verifying the reliability of the simulation results.