高速列车空调系统及车内流场分析

为检验高速列车空调系统设计的合理性,针对高速列车新风入口负压大、空调管路系统复杂、密封性好 的特点,建立了车厢内部与空调系统的整体模型.用有限体积法求解计算流体力学的控制微分方程,对整体流场 进行数值模拟,得到了风速、温度、湿度和CO2 体积浓度在客室内的分布,并用流场指标和热舒适性指标对客室 内的热舒适性进行了评价.结果表明:夏季列车以350km/h的速度行驶时,车厢内温度场分布比较均匀,CO2 体积浓度平均值为0.07%,满足不大于0.15%的舒适性要求;过道处风速高,导致有效温度差最大为-4.5C, 低于舒适指标标准值2.8C;送、回风方式是保证流场参数均匀分布及热舒适性的关键. 

Analysis of Air Flow Field in Air Conditioning System and Compartments of High-Speed Trains

In order to test the rationality of the air-conditioning system design of high-speed trains,an entire geometry model for compartment and air-conditioning system of high-speed trains was built considering the characteristics of negative pressure at fresh-air inlet,complicated air-conditioning pipes and good airtightness.The airflow field in the entire geometry was simulated by solving the governing differential functions of computational fluid dynamics（CFD） using the finite volume method.The distributions of velocity field,temperature field,humidity field,and CO₂ concentration in the chamber were obtained,and the thermal comfort was evaluated by flow field indexes and comfort indexes.The results show that when a train is running at 350 km/h in summer,the temperature distribution is uniform in compartments;the average value of CO₂ concentration is 0.07% to meet the demand for comfort（less than 0.15%）;because of the high wind velocity,effective temperature difference at aisle is-4.5 ℃,which is 2.8 ℃ below the standard value of the thermal comfort index;and an appropriate air supply and recycle mode is crucial to obtain uniform flow field and good thermal comfort.