送风模式对挥发性有机物在动车组客室内的扩散特性影响机制研究OA

Due to the requirements of lightweight high-speed trains and the development of advanced materials,a large amount of lightweight decorative materials have been inevitably used,which has increased the emission of volatile organic compounds(TVOC)in the passenger compartments of newly built trains.If adequate ventilation is not carried out,it can lead to a large accumulation of pollutants or even exceed the standard.To investigate the influence mechanism of the spatio-temporal distribution pattern of TVOC concentration in the passenger compartment under train operation and determine whether the TVOC concentration complies with the current standard specifications,it is necessary to explore the propagation characteristics of TVOC under different air supply modes,providing a theoretical basis for improving the air environment in the compartment.This article took the middle car of a certain type of EMU train as the research object,established a full-scale three-dimensional numerical model covering the passenger compartment space and the air duct system,simulated the flow field distribution and TVOC concentration field in the passenger compartment,and analyzed the influence of different air supply modes on the distribution characteristics of TVOC in the train passenger compartment.Some conclusions are drawn as follows.Under the two air supply modes of winter air supply and summer air supply,the TVOC concentration in the corridors at both ends of the passenger compartment is higher than that in the passenger seat area of the passenger compartment.The accumulation of TVOC occurs in some local areas due to the influence of vortices.By analyzing the inter-row transmission of TVOC in the seats,it is found that the TVOC concentration in the seat area of row C located in the middle of the passenger compartment is much lower than that in the other rows.By comparing the two air supply modes,in the winter air supply mode,TVOC is prone to accumulate in the middle and bottom of the passenger compartment,while the summer air supply mode has a better removal effect on TVOC.Under the summer air supply mode,the average concentration of TVOC in the passenger compartment is 0.003 8 mg/m3,and the maximum concentration is 0.012 mg/m3.Under the winter air supply mode,the average concentration of TVOC in the passenger compartment is 0.004 0 mg/m3,and the maximum concentration is 0.017 mg/m3.This study can demonstrate that the ventilation modes of the current ventilation system can all maintain the concentration of TVOC in the passenger compartment within the range stipulated by the current standards.The results can compare the differences in the removal efficiency of TVOC among different air supply modes,and propose an engineering reference idea for the rapid and efficient removal of TVOC in new high-speed trains.