Effects of Air Supply Modes on Ventilation and Respiratory Pollutant Dispersion Characteristics of High-Speed Trains
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摘要:
高速列车交通网络发达且载客量大，但车厢环境封闭易造成污染物的堆积，为提高乘车舒适性和安全性，基于计算流体动力学理论（CFD），建立满载工况的全尺寸车厢通风计算模型. 针对排风口位于两侧车窗上端的排风方式，采用速度不均匀系数、温度不均匀系数、能量利用系数和通风效率作为列车通风系统的评价指标，对比研究6种送风方式对车厢内流场特性和呼吸污染物扩散特性的影响，包括多孔顶板送风、下部送风、多孔顶板送风 + 下部送风、局部多孔顶板送风、侧顶送风、局部多孔顶板送风 + 侧顶送风. 研究结果表明：通过调整风口之间的流量分配比例可以使送风气流均匀地流向客室两侧，改善车内温度均匀性；采用下部送风时，有助于提高通风系统的能量利用系数和通风效率，分别高达1.38和1.21，但会恶化车内乘坐舒适性；通过研究乘客之间呼吸污染物的相互影响情况发现，第C列乘客的呼吸污染物容易向第B列乘客的呼吸区域进行扩散，加剧乘客之间的交叉感染；通过减小多孔顶板的送风口尺寸，采用局部多孔顶板送风可以有效缓解该现象，使污染物的体积浓度下降至0.0019.
Abstract:High-speed trains carry a large number of passengers and have a well-developed transportation network. However, the closed compartment environment is likely to cause the accumulation of pollutants. In order to improve the comfort and safety of the train, a full-scale compartment ventilation model of the train under full load conditions was established based on computational fluid dynamics (CFD). For the exhaust mode where the exhaust vent was located above the window, the coefficients of velocity non-uniformity, temperature non-uniformity, and energy utilization, as well as ventilation efficiency were used as the evaluation indexes of the train’s ventilation system. The effects of six air supply modes on the flow field characteristics and diffusion characteristics of respiratory pollutants in the compartment were comparatively studied, including perforated ceiling air supply, lower air supply, perforated ceiling air supply combined with lower air supply, local perforated ceiling air supply, side roof air supply, and local perforated ceiling air supply combined with side roof air supply. The results show that by adjusting the flow distribution ratio between the air vents, the air supply can flow evenly to both sides of the passenger compartment, thereby improving the temperature uniformity in the train. When the lower air supply is used, it helps to improve the energy utilization coefficient and ventilation efficiency of the ventilation system, which are as high as 1.38 and 1.21, respectively. However, it will deteriorate the riding comfort of the train. By studying the interaction of respiratory pollutants among passengers, it is found that the respiratory pollutants of passengers in column C tend to diffuse to the breathing area of passengers in column B, thereby aggravating cross-infection among passengers. Reducing the size of the air supply outlet of the perforated ceiling and using local perforated ceiling air supply mode can effectively alleviate this phenomenon and reduce the volumetric concentration of pollutants to 0.0019.
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Key words:
- high-speed trains /
- tracer gas /
- internal flow field /
- pollutant diffusion /
- numerical simulation
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图 7 速度和污染物浓度的数值模拟结果和实验数据对比
Figure 7. Comparison of velocity and pollutant concentration by numerical simulation with experimental data
图 13 不同位置垂直面上的平均污染物浓度
Figure 13. Average pollutant concentration in vertical planes at different positions
图 15 乘客呼吸区域的污染物平均浓度
Figure 15. Average pollutant concentration in breathing area of passengers
表 1 通风参数
Table 1. Ventilation parameters
通风方案 送风口位置 单个风口尺寸 送风流量比例/% 排风流量比例/% 左侧 右侧 方案 1 多孔顶板送风 1000 mm × 18300 mm 100 40 60 方案 2 下部送风 150 mm × 18300 mm 100 40 60 方案 3 多孔顶板送风 1000 mm × 18300 mm 50 50 50 下部送风 150 mm × 18300 mm 50 方案 4 局部多孔顶板送风 500 mm × 18300 mm 100 40 60 方案 5 侧顶送风 100 mm × 18300 mm 100 40 60 方案 6 局部多孔顶板送风 500 mm × 18300 mm 50 40 60 侧顶送风 100 mm × 18300 mm 50 
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表 2 评价指标
Table 2. Evaluation indicators
通风
方案通风
方式速度
不均匀系数温度
不均匀系数能量
利用系数通风
效率方案 1 多孔顶板送风 0.46 0.06 1.17 1.11 方案 2 下部送风 0.74 0.12 1.38 1.21 方案 3 多孔顶板送风 + 下部送风 0.46 0.07 1.23 1.07 方案 4 局部多孔顶板送风 0.69 0.07 1.00 0.95 方案 5 侧顶送风 0.53 0.06 1.09 1.02 方案 6 局部多孔顶板送风 + 侧顶送风 0.51 0.07 1.27 1.04
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