Research On Thermal Comfort Of Air Conditioned Carriage With Semicushioned Seats

With the rapid development of China’s railway industry, the air conditioning train becomes one of the main transportation for people traveling. Because of the good sealing of air conditioning train, the thermal comfort in air conditioning train has been drawing more and more attentions. At present, it’s not optimistic about the thermal comfort environment of railway air-conditioned passenger compartment for China, specific outstanding summer cool, winter partial heat in air conditioning train. Due to thinking highly of the air transport, the research on the thermal comfort in air conditioning train is carried out by few scholars in the developed countries in the West. In recent years, the study on the thermal comfort in air conditioning train is promoted, but most of these are put emphasis on standard quota of staff and no-load, that has not been involved in overcrowding situation. According to the current situation of our country, the phenomenon of overcrowding is seriously common in railway, especially holidays and during winter and summer vacation. The distribution of air flow field in the carriage is seriously affected by the phenomenon of overcrowding,and so is the thermal comfort. Therefore, in order to research the thermal comfort in air conditioning train, the physical model of25G-air conditioning train is established. The simulation of air velocity and temperature distribution on the air conditioned railway carriage was carried out and the thermal comfort in air conditioning train is analyzed. In this study, including the following aspects:1.The physical model of25G-air conditioning train is established basing on the simplification of the carriage by CAD. Then, the simulation of air velocity and temperature distribution on the air conditioned railway in summer was carried out by using the turbulence model of RNGκ-ε for three cases that CFD (Computational Fluid Dynamics) in the conditions of no-load, officials said and indicated. The affections on air velocity and temperature distribution by return air grille, air supply outlet, solar radiation and passengers are studied. The analysis shows that the distribution of temperature and air velocity field is affected by the return air grille, air supply outlet, solar radiation and passengers.2. According to the distribution of temperature and air velocity field and the passenger’ different feelings in the uneven distribution of air conditioning air flow, the thermal comfort of the carriage of passengers is analyzed by Thermal comfort evaluation index that the PMV (Predicted Mean Vote) and PPD (Predicted Percent Dissatisfied) evaluation index system. The affections on distribution of temperature and air velocity field by different speed, temperature and air supply are analyzed. The analysis shows that while the bar supply air in air conditioning train is more appropriate than the orifice plate supply air, too big speed of air supply the compartment makes the passengers have local blowback feeling, though it improves the thermal comfort near the window. At present, the parameters of air supply are difficult to meet the thermal comfort of passengers in railway, especially in overcrowding situation.3.According to the current overcrowding situation of our country’s air conditioning train, focusing on study on how to meet the thermal comfort requirements of passengers inside in overcrowding situation. The return air grille, air supply outlet are improved. The comparative analysis of different sections in air conditioning train of overcrowding to achieve the best distribution of temperature and air velocity field, in order to provide the basis for the future of the thermal comfort study of the air conditioning railway inside.