Objective At present, public areas of metro station generally adopt the traditional mixed ventilation airflow organization mode, resulting in significant energy waste in air-conditioning systems. In large station spaces, it is only necessary to ensure that the environmental parameters of personnel activity areas remain within a suitable range. Therefore, an optimization of the airflow organization in metro station large spaces is required.

Method The theories of cylindrical wall-attached jet ventilation, the air supply mode of vertical wall-attached jet with deflectors, and the principles and characteristics of the variable working zone air supply mode are briefly introduced. A variable working zone air supply method suitable for large spaces in metro stations is proposed. For the three air supply modes of traditional mixed ventilation, wall-attached jet airflow, and variable working zone air supply, numerical simulation calculations are conducted using CFD (computational fluid dynamics) software. Key airflow organization indicators in the working zone (elevation of personnel activity area ≤ 2.0 m above ground), including velocity field, temperature field, and air age field, are systematically analyzed and comprehensively evaluated.

Result & Conclusion  The variable working zone air supply mode can effectively deliver cooling capacity to the personnel activity area. Compared with the other two air supply modes, this mode achieves the highest ventilation efficiency and the shortest air age while ensuring human comfort, enabling the fastest removal of heat and pollutants and improving the air quality in the personnel activity area effectively.