Study On Dual Air Source System And Hydraulic Characteristics Of 300 KM/H Electric Multiple Units

300km/h EMU remove the split air conditioning of the cab in the original 200EUD, and lead the duct of passenger compartment to the cab. There are great changes in the structure of the air conditioning system as follows: Increasing the cooling capacity of unit, leading the duct of passenger compartment to the cab, designing the air supply mode of the cab and the layout of the pipeline, and changing the number of the air supply outlet. All of these aim to improve the traveling environment and driving environment, provide a comfortable environment for drivers, improve the safety of drivers,and improve train design efficiency of air conditioning system at the same time. 300km/h two-stage air-conditioning system is still use Double-ring air duct unit. Currently, in the field of domestic train air conditioning systems, double ring structure of the duct is rarely applied, relevant theoretical basis and design basis is still relatively small. These need relevant studies in the operational characteristics of dual source circular air channel, for the future providence of the basis for design and research.Taking Double-loop air-conditioning unit air supply system and Passenger compartment air distribution of the 300km/h EMU first due as examples in this paper, researches are studied as follows:Firstly, the CFD simulation of the Air supply system and the Passenger compartment air distribution is done. Adjusting the air supply volume by regulating the connection area between the vertical pipe and the under -floor duct, the unbalance rate is controlled in less than 10%. The simulation results of temperature and velocity fields in the car are that: both of them are well distributed, which satisfies the comfort demands.Secondly, the experiment mockup is established by the simulation results of the area between the vertical pipe and the under floor duct. The volumes of the outlets have been tested. By contrast, the simulation and the experiment results are very close, and the tendency is accordant. The results satisfy the engineering demand. This air supply volume adjusting solution by changing the simulation model is proved to be feasible and effective.Lastly, two-unit circular duct have been made corresponding adjustments. The air diffuser of air velocity are tested that circular duct are under the condition of normal running in double unit and single unit. Test results show the air duct of the air ring uniformity and stability.