A Study On The Mass Of Air In Ventilation Of The Super Long Tunnel

With the continuous development of modernization process in China, the highwaynetwork in China is also in constant expansion, long and super long highway tunnelconstruction in large-scale also carrying out. Ventilation has always been a big and keyproblem of long and super long highway tunnel’s development. Not only relates to theoperation cost of the tunnel after completion, but also closely related to the safety or notof the operation environment in the tunnel. Because accidents of safety have beenemerge in endlessly for the ventilation problems of tunnel, been ranked first in all acci-dents of safety in tunnel, so the problem of tunnel ventilation research has also been thekey content studying by the experts and scholars from many countries all over theworld.This paper introduces the development of road tunnel ventilation, from the natureventilation first to the mechanical ventilation present in the tunnel, and the concentra-tion of pollutants as a standard for solution the demand of air for ventilation. At thesame time, this paper also introduces mechanism and operation of the mechanical ven-tilation and the basis for solution the demand of air for ventilation. On this basis, thispaper made the following research:1）State the theoretical basis of calculation for air demand, namely ventilation oftunnel need to satisfy the four assumptions of gaseous fluid, comparative and analysisthe differences of the need to air volume calculation between the 《Specifications forDesign of Ventilation and Lighting of Highway Tunnel》 JTJ026.1-1999andPIARC2012.2）Through the concrete engineering instance, respectively according to the《Specifications for Design of Ventilation and Lighting of Highway Tunnel》JTJ026.1-1999and PIARC2012related calculation of pollutants and the correspondingneed air volume calculation of pollutants and the corresponding need air volume calcu-lation of the related formula, and in accordance with their respective provisions allowthe pollutants concentration, calculated three characteristics years corresponding threeworking speed situation need to air. Through the Fluent module belong to the ANSYS,the three characteristics years working speed60km/h of the need to air in numerical si-mulation, the corresponding observations out the effect of pollutants.3）Focus on two kinds of specification different calculation method and make the need to air volume calculation of differences, combined with the results of numericalsimulation, analysis of causes of this kind of differentiation.4）According to the results of the comparison and analysis, combined with theactual situation, I think some formula and coefficient of determination in the《Specifications for Design of Ventilation and Lighting of Highway Tunnel》JTJ026.1-1999is worth further discussing.