Numerical Simulation Study on Ventilation Optimization Design of Extra-Long Double-Line Mountain Tunnels with Parallel Heading: A Case Study

There are many issues affecting multi-hole parallel tunneling and long tunnel ventilation, such as insufficient fresh air supplied at the face, pollution by contaminated winds, uncoordinated work among multiple fans. In view of these issues, this paper uses numerical simulation software Fluent combined with orthogonal analysis test method, and, based on actual working conditions Yuelongmen Tunnel Chenglan Line, simulates parameters duct, installation position jet fan cross channel, operation status The main conclusions follows: (1) primary factor CO discharge from face is distance between exit duct secondary diameter while least influential factor; (2) intersection channel should be set close to source in a way prevent hitting windward side thereby avoid causing wind contaminate adjacent tunnel; (3) tunnels which blasting operations do not occur, simultaneous use high-power supplies fans will reduce pressure tunnel, generate an difference trap polluted air, ventilation effect.