Abstract: To improve the traditional ventilation method for the underground utility tunnel and air quality, and reduce the operating cost of the utility tunnel, the shortcomings of the traditional ventilation methods of the underground utility tunnel are analyzed and innovative design for the ventilation of the utility tunnel is carried out. An unpowered exhaust fan is added to each node well of a test section of an underground utility tunnel to address the problems such as insufficient natural ventilation capacity, poor air quality in the utility tunnel, high energy consumption of mechanical ventilation, and high operating cost. A mechanical exhaust fan is set in each ventilation section to address the problems of excessively high temperature in the utility tunnel and toxic smoke discharge in case of fire under the help of the automatic fire alarm system. The application results show that the ventilation in normal and abnormal conditions can both meet the requirements of the relevant specifications, and the project investment and the operation cost can be reduced, the air quality can be improved.

Key words: utility tunnel, ventilation design, unpowered ventilation, mechanical ventilation