One-dimensional Flow Simulation Of Long Highway Tunnel Ventilation In Construction And Operation Period

With the rapidly carried out of infrastructure in recent years，the national highwaynetwork in national plan is gradually completed, a large number of highway tunnelsappeared in the large-scale highway construction. In the construction of the long and largehighway tunnel, there is a sound technical guidance, but, the ventilation has been in aneglected state. And with the completion of highway tunnel, the operating ventilation and fireprevention will become a very big problem.With the help of the software bases on the method of node network which is a calculationof ventilation in tunnel compiled on the VC++platform, it solvers the ventilation ofconstruction and operational phase in Mi Xiliang special long highway tunnel. In the paper, itfits the tunnel traffic pressure as a cubic polynomial to the iterative calculation process of theprogram. It can accurately express the traffic pressure changes with the wind speed inside thetunnel.In the Construction Ventilation solver, the tunnel is divided into five ventilation section.The ventilation mode is changed with the progress of construction. The fitted ventilationmethod is chosen for the different section by the calculation of different ventilation systemand a ventilation program is developed. The results show that the diameter of air supply tubehas a great impact for the pressure loss, so it must try to use the tube of great diameter; theventilation method which supplies and exhausts air through tunnels can not only reduces thepressure but ensures a good construction environment for the follow-up operations in the airsupply tunnel.Using the software to solve the tunnel ventilation design of the normal operation, andverify the rationality of the design of ventilation. Get the size of the tunnel traffic pressure bycalculating with analytical formula. It shows that the traffic pressure accounted for a smallerproportion in the total pressure. The tunnel line is divided into11fire partition. Solve thetunnel ventilation according to the different regions where a fire broke out to develop acontrol program of ventilation.