Design And Simulation Of High-speed Locking Railway Retarder Second Critic Speed Valve

The marshalling yard is responsible for the dismantling and marshalling of freight trains.The realization of marshalling yard operation automation plays an important role in promoting railway transportation safety and capacity.As a kind of station equipment,railway rolling stock anti-running device play an important role in the process of marshalling,but at the same time,it also brings safety risks.Therefore,the high-speed locking railway retarder is developed instead of the traditional railway rolling stock anti-running device,which can give consideration to the station operation automation and safety,and has a good engineering application prospect.Through the in-depth analysis of the existing high-speed locking railway retarder piston components,especially the structure and working principle of the second critic speed valve,the reason for the large error of the second critic speed valve in the judgment of the second critical speed is found.On this basis,the improvement scheme of the second critic speed valve and improved formula for calculating the second critical speed is proposed,and detailed design is carried out.The structural parameter calculation and strength check of the piston components and the second critic speed valve of the high-speed locking railway retarder are completed.In order to analyze the performance of high-speed locking railway retarder,the displacement equation of vertical sliding stroke of sliding cylinder was established.At the same time,Fluent software was used to establish the transient simulation model of high-speed locking railway retarder based on the dynamic mesh model and volume of fluid model.The transient simulation model can be used to complete the simulation calculation and analysis of the flow field in the high-speed locking railway retarder and the pressure difference between the upper and lower surfaces of the second critic speed valve plate,then analyze the performance of high-speed locking railway retarder.The transient simulation model is used to calculate and analyze the improved design of high-speed locking railway retarder.The results show that the braking energy meets the requirements and the speed error of the second critic speed valve is reduced,which also verifies the correctness of the model and method in this thesis.At the same time,the transient simulation model can be used as a design method of high-speed locking railway retarder,which has certain reference value for the development of high-speed locking railway retarder.