Influence of Base Emission Factor Update on Tunnel Fresh-Air Demand
To solve the design waste and idle operation of ventilation systems in urban tunnels caused by the continuous update of traffic vehicles,the influence of base emission factor update on tunnel fresh-air demand was studied,and two calculation methods of base emission factor in response to vehicle update were established.To begin with,the key parameters updating over time in the fresh-air demand formula were determined as base emission factors through theoretical analysis.Then,the influence of base emission factors and gradient-speed factor update on fresh-air demand was obtained based on quantitative analysis.Finally,according to foreign concepts and actual design experience,two calculation methods for base emission factors considering time were proposed.The results show that Chinese road tunnel ventilation design standards refer to the PIARC ventilation report when formulating the base emission factors,with the reasons explained.Compared with those in 2000,the base CO,NOx,and PM emission limits in 2021 are reduced by 81.6%,76.7%,and 97.9% respectively.The most unfavorable design method using vehicle pollutant emission limits as base emission factors is established,and the base emission factors of each pollutant in 2018 are calculated as follows:the base CO emission factor is 0.0011 m3/(veh·km),and the base PM emission factor is 0.4610 m2/(veh·km),which are reduced by 84.3% and 77.0% compared with China Standard in 2014.The research results establish and verify the calculation method of base emission factors,which provides a reference for the design of urban road tunnel ventilation systems.
万方数据
维普
