The large longitudinal impact of heavy-haul trains is the main factor limiting their development,and the asynchronous nature of train-braking systems is the main cause of this longitudinal impact.In this paper,a segme...The large longitudinal impact of heavy-haul trains is the main factor limiting their development,and the asynchronous nature of train-braking systems is the main cause of this longitudinal impact.In this paper,a segmented electro-pneumatic braking solution fully compatible with the existing freight-train braking system in China is proposed to improve the synchrony of train-braking systems.A simulation model for this braking system is developed based on air-flow theory,the 120 distribution valve and electronic control devices.The braking characteristics obtained from simulations are compared to those from the train-brake testing platform,and show high fidelity.On this basis,the effects of the new braking system on the braking capacity and longitudinal impact of a 20000 t heavy-haul train are analysed by further simulation.The results show that during service brakes,the segmented electro-pneumatic braking system can increase the braking capacity by 4.2–24.7%and reduce the coupler force by 21.6–68.0%.Therefore,it can be seen that the segmented electro-pneumatic braking system is a new type of electro-pneumatic brake that meets the needs of the Chinese railway network.It solves the problem of the longitudinal impact of heavy-haul trains satisfactorily,and its compatibility with the existing braking system(resulting in a reduced modification workload)makes it possible to maintain normal operations on heavy-haul lines while trains undergo modification.展开更多
文摘The large longitudinal impact of heavy-haul trains is the main factor limiting their development,and the asynchronous nature of train-braking systems is the main cause of this longitudinal impact.In this paper,a segmented electro-pneumatic braking solution fully compatible with the existing freight-train braking system in China is proposed to improve the synchrony of train-braking systems.A simulation model for this braking system is developed based on air-flow theory,the 120 distribution valve and electronic control devices.The braking characteristics obtained from simulations are compared to those from the train-brake testing platform,and show high fidelity.On this basis,the effects of the new braking system on the braking capacity and longitudinal impact of a 20000 t heavy-haul train are analysed by further simulation.The results show that during service brakes,the segmented electro-pneumatic braking system can increase the braking capacity by 4.2–24.7%and reduce the coupler force by 21.6–68.0%.Therefore,it can be seen that the segmented electro-pneumatic braking system is a new type of electro-pneumatic brake that meets the needs of the Chinese railway network.It solves the problem of the longitudinal impact of heavy-haul trains satisfactorily,and its compatibility with the existing braking system(resulting in a reduced modification workload)makes it possible to maintain normal operations on heavy-haul lines while trains undergo modification.
