Static And Dynamic Numerical Simulation Of Piston Rod Cap Seal Structure At Different Temperatures

The sealing performance of Stirling engine piston rods seriously restricts the promotion of dish solar power generation.In this paper,the Sterling piston rod cap seal is taken as the research object,and the influence of temperature on its sealing performance is taken as the starting point.The static and dynamic sealing performance of the cap type seal seal at different temperatures is explored.In this case,the influence law of working conditions on the cap seal is revealed,which provides theoretical basis and scientific guidance for the improvement of piston rod sealing performance.This paper uses a combination of theoretical research,numerical simulation and experimental verification.Firstly,based on the mechanism of the cap seal,the static and dynamic sealing principle of the piston rod cap seal is analyzed.The conditions of the static and dynamic seal are obtained.The influence mechanism of the working condition on the cap seal is analyzed theoretically.The post-simulation simulation and experimental research laid the theoretical foundation.Secondly,the static and dynamic sealing performance analysis was carried out at different temperatures by establishing a cap seal finite element model.Based on the study of the cap seal structure and materials,the finite element software ABAQUS was used to establish the cap seal finite element model through mechanical analysis and temperature field analysis;the actual application conditions of the simulated cap seal were static at stop(20℃)and Under the working steady state(120℃)working condition,the numerical simulation of the static temperature sealing performance of the cap seal is carried out.The stress distribution and variation law of each seal are analyzed,and the effects of different temperatures on the sealing performance are obtained.Thirdly,numerical simulation studies were carried out on the effects of pre-compression rate,working medium pressure,reciprocating speed and friction factor.Taking the maximum Von Mises stress and contact stress of the cap seal structure as the analysis standard,the influence law under different working conditions was studied,and the influence curves of various influencing factors on the cap seal were drawn.Finally,the failure mode of the cap seal was In practical applications,it is pointed out that the pre-compression rate and the working medium pressure have a great influence on the cap seal,and the reduction of the friction factor and the reciprocating speed is beneficial to prolong the service life.Finally,the piston rod seal test rig was built to verify the simulation results.Thewear state and leakage amount under different top chamber pressures and reciprocating speeds were analyzed by preparing multiple sets of cap seal samples.Comparing the simulated temperature rise and the test temperature rise,the relationship between the different working temperatures and the top chamber pressure was discussed.In summary,through theoretical research and experimental verification,temperature has a great influence on the performance of the cap seal.At normal temperature,the static sealing performance is better.At high temperature,the steady-state dynamic sealing performance is superior;the study of working conditions shows that: As the pressure increases,the radial wear of the C-ring becomes larger,the leakage becomes larger,and the seal failure is accelerated.As the speed increases,the wear amount becomes larger and the sealing life is shortened;the high ambient temperature rises faster than the room temperature,at 20 ℃,The sealing system reaches thermal equilibrium within 10 min,while at 120℃,equilibrium is reached within 6 min.In short,mastering the speed of temperature rise and the time of heat balance,understanding the influence law of temperature and various working conditions is of great significance for controlling sealing performance and reducing friction and wear,and predicting seal life.