Study on air distribution characteristics of air orifice plate in CRH6 intercity rail

Abstract

The train industry is developing quickly in China. At the same time, the comfort of carriages is getting more and more attention. As the dimension of carriage is quite limited, the supply air of air-conditioning system should be dispersed in very short distance to avoid draught sensation. Among the existing supplying systems, the orifice plate has the following advantages: short jet flow range, well diffused, and mix flow field. If orifice plate was mounted at the top of the carriage, piston flow can be formed easily and the thermal comfort can be improved. The diameter of hole on the orifice plate and percentage of open area on the plate are important factors affecting its flowing performance. In this paper, we studied the effect of perorate rate on flow characters inside the carriage. The CFD model of CRH6 intercity rail with orifice plate was set up to simulate the air distribution. Experiment was also carried out to verify the reliability of the CFD models. The effect of different open area on uniformity of air distribution was further investigated. The velocities on selected cross sections were compared. The results showed that as the percentage of perforate rate (PR) decreased, the difference of air velocity in the occupant zone became larger, the air distribution tended to worse. It was also found that the flow uniformity were quite similar when the open area was larger than 7.1 %. © Springer-Verlag Berlin Heidelberg 2014.