Holistic approach to improve air quality and provide smoke management for Chicago Union Station and tunnels using hybrid longitudinal and semi-transverse ventilation

摘要

Chicago Union Station and Tunnel Complex has an existing ventilation system for diesel smoke removal; however, the ventilation system was not initially designed for fire emergency, and the existing diesel smoke removal ventilation is insufficient to meet possible proposed requirements set forth in new air quality standards. The proposed ventilation design discussed in the paper serves both normal station operation diesel smoke removal and fire smoke management. The proposed ventilation system uses the hybrid longitudinal and semi-transverse ventilation scheme, which is a unique 2-step transit tunnel ventilation approach. Heat and smoke transport within the exhaust air plenums was simulated in the CFD analysis in which the platform exhaust system with louvers, plenums, and in-line exhaust fans was modeled as a nodal network and coupled with the CFD model to solve for conservation of mass, energy, and momentum. Noise analysis is performed using the SoundPLAN software to evaluate alternatives and to locate fans in compliance with sound pressure level limits in the station.