Optimization Study On Non-duct Inducement Ventilation Of Controlling Fire Smoke In An Underground Garage

With the increasing of car ownership, cars’storage has become an important issue in traffic management. Underground garage has been popularized gradually due to its large building area and centralized management. Underground garage brings convenience to people, but at the same time brings a series of security issues, especially the fire issues. Fire smoke is hardly to spread because of the high tightness in underground garage, designing the right ventilation system is particularly important. This paper based on computational fluid dynamics theory and software FDS as the operational platform, numerical simulation studies on non-duct inducement ventilation of controlling fire smoke in an underground garage, and optimizing the system based on the results of the CO density field, the temperature field and the visibility. We finally find out the best system.In order to obtain the correct mathematical model and boundary conditions, this paper first numerical simulated the velocity field of a single inducement fan, and compared the simulation results with the empirical formula, determined the correct mathematical model and boundary conditions ultimately, all these were the reliable foundation for latter simulations.Compared with traditional duct ventilation system, non-duct inducement ventilation is more and more popular for its space-saving and high ventilation efficiency. However, its design method is lack of mature theoretical support. On this basis, this paper simulated the non-duct inducement ventilation in an underground garage, we put forward two improved systems by varying the relative position between air-feeding ventilator and air-exhausting ventilator, adjusting the directions of jet fans to change the airflow in the underground garage. We carried out simulation studies on improved systems based on the results of the CO density field, the temperature field and the visibility, and determined the most optimal design system. All the analysis method and the results presented in this paper can be used in engineering design.