Analysis of air conditioning energy consumption in subway stations with closed integrated systems in hot summer and cold winter zone

The closed integrated system is a commonly-adopted form in the ventilation and air conditioning (VAC) system of subway stations, with the advantages of simple system form and low construction investment. However, the energy consumption is higher than that of the platform screened door system. This study investigates the VAC energy data of 23 subway stations with closed integrated systems in a city in the hot summer and cold winter zone, according to which the energy use level is given. Then the representative stations with medium energy consumption level are selected as the research objects, and energy-related data of the VAC system on typical days of the air conditioning season are researched and tested in detail, including unorganized air infiltration volume, mechanical outdoor air volume, operating parameters of chillers, sub-system energy consumption, etc. Based on the actual data, the reasons for the relatively high cooling load and energy use of stations with closed integrated systems are analysed, and the energy saving potential is calculated. The results show that the VAC energy consumption of a typical summer day can be reduced by approximately 31% via reducing the mechanical outdoor air volume and improving the energy efficiency. The research results can provide data support for the energy consumption level and energy-saving potential of subway stations with closed integrated systems.