Effect of air supply mode on the airflow distribution inside soft sleeper compartments of air-conditioned trains

摘要

Trains are an important means of transportation for people to travel. The train's soft sleeper compartment space is relatively small, and the density of people is relatively large. Therefore, improving the thermal comfort and air quality of the compartment is of great significance for ensuring a healthy travel environment. To analyze the appropriate mode of conditioned air supply in train soft sleeper compartments, the airflow distribution inside soft sleeper compartments is simulated numerically at four different air supply modes, namely, sidewall air supply with slot diffusers, perforated ceiling air supply, bedside task-ambient air conditioning, and displacement ventilation. The reliability of the numerical simulation models is verified with the experimental data in the literature. Comparative analysis is made in terms of the compartment temperature, velocity, predicted mean vote and predicted percentage dissatisfied (PMV-PPD), and ventilation efficiency among various modes of air supply. The four air supply schemes are evaluated comprehensively by stochastic multicriteria acceptability analysis (SMAA-2). As the computational results show, bedside task-ambient air conditioning is the best air supply mode in terms of comprehensive performance indicators, followed by the sidewall slot air supply. The perforated ceiling air supply ranks third, and is superior to displacement ventilation.