Case study of train-induced airflow inside underground subway stations with simplified field test methods

With the rapid development of subway construction in developing countries like China, energy conservation in subway stations is gaining popularity within society. Generally, ventilation and air-conditioning play important roles in the total energy consumption. As a major feature of subway stations, the train-induced airflow (TIA) driven by moving trains has been recognized for years, having a great influence on indoor environment and energy consumption. However, there is a lack of case study on real amount of train-induced airflow inside stations. In order to get extensive knowledge of the real situation, this paper proposes a set of simplified methods to measure and calculate train-induced airflow rates. Using these methods, field tests were conducted in several typical underground subway stations in China during the spring of 2016. This paper presents the basic situation of train-induced airflow in these stations and the influence of different ventilation modes. Based on the fact that there exists unneglectable amount of train-induced airflow, and considering the demand-supply analysis of fresh air, the potential for high levels of energy savings could be identified in the mechanical ventilation systems of these stations. These new findings are of great benefit for energy-efficient operation of existing stations.