Numerical Simulation Of Air Conditioning Ventilation System Of Subway And Carriage Air-flow Field

The subway is an efficient traffic tool with high communicating quantity, which caneffectively solve traffic jam of urban ground. At present, people not only enjoy fast andconvenient life, but also initiating low-carbon and environment protection. Air-conditioningsystem is the important auxiliary equipment of the train, which performance directly affectsthe thermal comfort of the passengers. Using of CFD technology to the train interior flowfield numerical simulation, we can obtain a more comprehensive quantitative result, withgood practical significance in solving specific engineering problems.This paper to certain mid-carriage as the research object, establishes the3-D modelcontaining supply air duct, no-loaded carriage, fully-loaded carriage and gangway, usingstandard turbulence model and the SIPLE algorithm for numerical calculation, allwithin the flow field.The supply air duct exit of original design has poor blast uniformity, individual outlet ofthat appears reflux outlet, all of which need to be improved. First remove the outlet of theirrational in the optimization process is not ideal, because there is still the reflux outlet.Basing on analysis of the supply air duct for the wind principle, a perforated baffle need to beadded on both sides of the air inlet, which can provide more cold wind for outlet near the airconditioning unit, thus greatly improve the uniformity of air duct.The no-load calculation results demonstrated that the performance of the air conditioningunit. The cold blowing rate is very adequate and the fluidity of the air in the passenger area isbetter. It can realize the air recirculation by means of the system of the exhaust outlet and airreturn, while improving the activeness about the indoor air distribution movement. After putthe human body heat source into the carriage, the air fluidity become worse, consequently, theheat dissipation of passenger has an effect on the environment. In this paper, with theintroduced European EN14750-1standard, it contrasted and analyzed each specific area of theenvironment. As a whole, the thermal comfort of passengers is better, and the air conditioningand ventilation system meet the design requirements.It is shown two flow field of the intersection intuitively by numerical calculation of thegangway. It provides more comprehensive reference information on the design anddevelopment of the air conditioning system.