Study On The Fire Heat Release Rate And Ventilation Of Highway Tunnel

At present, in order to analyse the temperature and smoke in the tunnel fire, we use numerical simulation to calculate the variable, which are all based on the fire heat release rate (HRR). Fire heat release rate (HRR) reflects the energy of the fire, which is the basic factor of the fire. Many countries had given the constant heat release rate for different fire scenario, although these models are very simple and the results are safe, but they can't simulate the growth and decay of the fire which are inconsistent to the actual. The fire growth phase is very important to the ventilation controlling, the escape time, and the location to escape when we study fire in the tunnel. French give the fire heat release rate, which can reflect the change of the entire fire, but the change is linear. In this paper, we use the mathematical model which is proposed by Ingason. H to give the corresponding heat release rate to describe the different fire scenarios, and use numerical simulation to research the change of temperature in the tunnel.In the recent ten years, longitudinal ventilation mode is still the main trend of long road tunnel ventilation. However, there is not a specifilication about application length of longitudinal ventilation tunnel in any country. We give the application of longitudinal length is 4000 meters from the perspective of disaster prevention. In order to enhance its application we research the complementary double-hole network ventilation of long tunnel. Finally, we study the ventilation model in this paper called two-hole ventilation in DaBie montain. According to the research we have given the design parameters of DaBie mountain road tunnel. By numerical calculation we analyse the temperature field, the velocity field and concentration field in this tunnel, which can demonstrate the feasibility and safety of the ventilation in the Dabie mountain tunnel.