Research On Smoke Exhaust Effect Of Highway Tunnel One-side Concentrated Extraction System

In recent years,with the accelerating development of transportation industry,the growth of our country highway tunnel is very rapidly.Because highway tunnel isalways located in the remote area and its structure is narrow and closed,and tunnel fire will pose a threat to personnel as well asgoods in the tunnel,so the smoke problem of highway tunnel fire has always been highly valued by relevant personnel.It is very rich that tunnel central smoke extract system usually set the independent exhaust duct at the top,but if the tunnel is restricted in height or the top independent exhaust duct is unable to set,it can be set on the one-side of the tunnel.Compared to the top central smoke extract system,the one-side concentrated extraction systemhas less related research.Therefore,it is necessary to study the smoke exhaust effect of the highway tunnel.Based on the background of a highway tunnel,the simplifiedtunnel model is established and simulated by using the Fire Dynamics Simulator(FDS).In order to obtain the reasonable parameters of the smoke vent,the smoke exhaust rate and longitudinal wind speed,the tunnel model are studied to reserch the influence of the one-side concentrated extraction system in the highway tunnel.The main work of this paper is as follows:?In order to study the effect of the arrangement,size and the group number smoke vent on one-side concentrated extraction system,40 MW fire scale is selected,through different smoke vent arrangement,sizes and the group number for FDS numerical simulation analysis.It is concluded thatthe way ofsmoke vent arrangementfor the one-side concentrated extraction system has influence on the effect of smoke extraction system at the beginning of the tunnel fire.Uniform arrangement way of smoke vent is better than that way of according to the group.The size of2? 1.5 ? is better than the size of 2 ? 1 ? and the arrangement of five groups is better than the four groups.?In order to study the effect of smoke exhaust rate tothe one-side concentrated extraction system,40 MW fire scale is selected.The smoke emission of tunnel fire is simulated under different smoke exhaust rate which is increased on basisof 160m3/s.Come to conclusion when the fire scale is 40 MW,with the smoke exhaust rate gradually increased the exhaust effect is also increased,but when it add to 280 m3/s the smoke exhaust effect is weakened.?For the study of the effect of longitudinal wind speed on the one-side concentrated extraction system,40 MW fire scale is selected.On the basis of 220 m3/s,analyzingthe effect of the one-side concentrated extraction system under different longitudinal wind speed.It is conclude that longitudinal wind speed 1.5 m/s and 2 m/s can make smoke control in a certain range.So taking the longitudinal wind speed 1.5 m/s is more economic and energy saving.Through the above content analysis,this paper further enrich and perfect the study of the one-side concentrated extraction system,which provides a certain reference for the safety of tunnel fire as well as the one-side concentrated extraction system design.