Study On Smoke Flowing And Ventilation Modes In Guangzhou Metro Interzone Tunnel

Taking a certain commonly long tunnel and a certain specially long one ofGuangzhou Metro as research representatives, study several contents as following:the pressure distribution and velocity values of piston wind in tunnel on normalcondition; the different temperature & velocity distribution of the heated air at thedifferent supply wind velocities in tunnel on obstruction condition, gain the optimalsupply wind velocity, which can guarantee the air conditioners above train to worknormally and economically; on the fire condition in tunnel, introduce the character ofsmoke flowing in tunnel, and utilize PHOENICS simulation software to simulate fivedifferent fire situations, and put forward corresponding ventilation measures andpassenger evacuation measures based on the simulation results. At last, set up areduced scale model tunnel according to resemble theory to validate the correctnessof PHOENICS simulation results by the comparison between the experimentalpicture and the simulation pictures.Research results show that:On the normal condition, the piston wind velocity in both the commonly longtunnel and specially long tunnel is about 40% of train running velocity. The pistonwind velocity involves with the train velocity,tunnel length,tunnel section-crossingarea, train section-crossing area,obstruction rate,coarseness of tunnel wall and trainsurface. When train running at high speed (exceeding 100km/h) in tunnel, pressurefluctuation ratio will exceed the standard at some special zone, such as the wind wellat the middle of tunnel and the rapidly changed section-crossing in tunnel, which willcause the rapidly changed wind pressure, and cause the passengers' ear ache.On the obstruction condition, the train and passengers give out heat, which heatthe air in tunnel continuously. The high temperature air will affect the normal work ofair conditioners on train. So it is necessary and important to supply the outsidc fresh air into tunnel to take away the extra heat and guarantee the air conditioners worknormally. PHOENICS simulation results show that 8m/s is the optimal supply airvelocity, which is not only economical, but also practical.On the fire condition, based on the Hear Release Rate (HRR) of 10 MW,introduce the smoke flowing character in tunnel, utilize five different kinds of firesoccurring on a commonly long tunnel and specially long tunnel respectively, and putup with corresponding ventilation measures and passengers evacuation measures. Atlast, set up a reduced scale model tunnel according to resemble theory, validate thecorrectness of PHOENICS simulation results by the comparison between theexperimental pictures and the simulation pictures. It shows that the experimentalpictures accord with the simulation ones well, which means the CFD simulationresults are correct and reliable.Three main research ways in this dissertation: Theory formulae calculation, CFDsimulation and reduced scale model experiment.