Pressure Wave Control Scheme for Metro Vehicle at Speed of 120 km/h

Abstract

Objective With the increasing demand for passenger comfort in urban rail transit, pressure wave control inside metro trains at speed of 120 km/h and above has become a an essential function of train air-conditioning system. Although high-speed EMUs and 160 km/h city railway trains already have mature pressure wave protection devices, most of them use pneumatic methods, complex in structure and relatively costly, therefore unsuitable for metro vehicles. Therefore, it is necessary to study pressure wave protection schemes suitable for metro vehicles based on their characteristics. Method Sampling tests are conducted on the pressure wave dynamics inside existing metro trains with speed of 120 km/h. Based on the test results and factors such as the operating routes and station layout, the primary influencing factors causing pressure wave dynamics inside the train are summarized, and a scheme using electric fresh air valves in the air conditioning system to control pressure wave dynamics inside the train is proposed. Validation of pressure waves inside the train is conducted under different opening degrees of the fresh air valve. Result & Conclusion Experimental results demonstrate that metro vehicles can utilize favorable factors such as fixed routes, fixed stations, and fixed dwell time to adopt an active pressure wave control scheme. The air-conditioning system controls the opening and closing of fresh air valves by using station information through the train network and speed signals, thereby controlling pressure wave dynamics inside the train. This scheme is relatively simple in structure, low in cost, and flexible in control compared to high-speed EMUs and 160 km/h city railway trains.

Keywords

• metro train
• pressure wave
• pressure wave control scheme