Query on several habitual concepts and schemes in smoke control system of underground railway transit engineering

While the domestic smoke control system design is under the transition from prescriptive to performance-based, the basic theoretical and evaluation system is yet to be set-up in underground railway engineering domain, of which the smoke control system design principle is still ambiguously between prescriptive and performance-based. Under the performance-based approach, smoke control system design shall focus on maintaining the tenable environment along the occupant evacuation path rather than others. From this prospective, discusses the issues of underground railway tunnel ventilation principle, HRR of train fire, and calculation of smoke exhaust mass rate, etc.