Study on the Performance of Adjustable Platform Screen Door in Subway Stations

In the last decades, the construction of subway systems has been in rapid progress in metropolis. Former studies have pointed out that substantial amount of energy is consumed by subway stations. Thus, the adjustable platform screen door (APSD) system is widely adopted, which is characterized by the energy-saving in both the cooling season and the transitional season. However, the installation of APSD system might result in thermal discomfort for passengers, which lacks investigation. This study aims to study the performance on the thermal comfort of subway station with APSD system. In this process, Computational Fluid Dynamics (CFD) Simulation was conducted using PHOENICS to obtain the velocity and temperature distribution under 3 kinds of train arrival patterns. Furthermore, Relative Warmth Index (RWI) was used to assess thermal comfort. The results show that the velocities of the platform and station hall are below 2.5m/s and 3.7m/s respectively, which is closely related to the train arrival pattern. With regard to the platform occupied zone, the RWI is between 0.04 to 0.19, which is almost within the thermal comfort zone according to the ASHRAE comfort classification. Nevertheless, for the occupied zone of the hall, the RWI is between 0.15 to 0.52, indicating relatively warm.

FORECASTING THE HEAT COMFORT OF PASSENGERS IN THE ELECTRIC TRAIN SHOPS. THEORY AND PRACTICE

Introduction. The purpose of the presented work was to determine the cause of complaints of passengers dissatisfied with the thermal comfort in electric trains equipped with modern air conditioning systems. In order, this work to be done both practical and theoretical research was carried out in two stages. This work includes the estimation of microclimate parameters in cars and passengers thermal comfort parameters. Material and methods. At the first stage, direct measurements of microclimate on passenger seats were conducted while the train was in operation. Subsequent analysis of the obtained figures indicates the average values of the studied parameters to correspond to their normative values. At the second stage, Fanger calculation method of determining passenger comfort or discomfort was used to analyze passengers’ assessment of various microclimatic situations in electric trains, both in local areas and in the salons of cars as a whole. Using the Fanger method, based on the results of theoretical calculations, a diagram was constructed. It contains curves showing the warmth index of passengers under different combinations of air temperature and velocity. Results. PMV indices were calculated by using the first stage measurements. Afterward, passengers heating comfort area was drawn on the diagram. It was made for each car and the passengers’ complaints were taken into consideration. Conclusion. The diagram analysis of passengers heating comfort area location relatively to zero point shows the percentage of dissatisfied passengers and it helps to explain the reason it occurs.

Analysis of the Wind Environment to Improve the Thermal Comfort in the Colonnade Space of a Qilou Street Based on the Relative Warmth Index

By analyzing measurements of the thermal environment of a qilou (arcade building) street, this study used the relative warmth index (RWI) to evaluate the thermal comfort in the colonnade space of a qilou. The analysis of the influence of the temperature, humidity, and wind speed on the thermal comfort in the colonnade space of a qilou street was conducted, and it was shown that the ambient wind speed had a strong influence on the RWI, indicating that a proper increase in the wind speed positively affected thermal comfort in this space. Then, this study also analyzed the effects of different forms of qilou streets on the wind environment by employing computational fluid dynamics (CFD) and summarized the architectural design measures that can improve the thermal comfort, including adopting back chamfer, street gaps, and the appropriate sizing of building components. It was concluded that the wind environment of a qilou could be optimized in terms of these measures, and the average RWI value decreased by 0.06, effectively enhancing the thermal comfort in the colonnade space. The research findings are applicable toward designing a thermally comfortable environment in the transitional space.

Preserving Passenger Comfort Through RWI Analysis

The air conditioning systems designed for passenger rail cars typically exchange heat with the outside air environment; when the trains operate within tunnels, the effectiveness of the air conditioning systems may diminish if the tunnel is too warm. Therefore, one of the traditional activation modes associated with rail tunnel ventilation systems is summertime cooling — for the purpose of maintaining onboard passenger comfort. However, summertime cooling modes can be problematic from the standpoints of fan operating pressure (i.e. an opposing air pressure is created whenever trains approach ventilation shafts), energy consumption and emergency preparedness (i.e. fans operating in the wrong direction when a fire is detected). In this paper, the thermal comfort of rail transportation passengers was studied in detail using the Relative Warmth Index (RWI) analyses to determine if the combination of: warm outdoor weather, the tunnel heat-sink effect, the rail coach design air temperature and typical commuting scenarios necessitated running the tunnel fans in a summertime cooling mode to preserve passenger comfort. If the summertime cooling mode could be eliminated, or even minimized, the tunnel ventilation usage/operating costs would be reduced, the fans would have a longer service life and the system would have greater overall availability for emergency events.