Study on CO Comprehensive Altitude Coefficient of Diesel Vehicle Based on Safety Dilution Method
In order to accurately carry out the construction ventilation design for high-altitude tunnels,a study was con-ducted on the calculation method and parameters for the air volume required for high-altitude tunnel construction ventila-tion.Through the multi-altitude tests on the CO emissions of diesel vehicles,the CO altitude coefficient of diesel vehicles was obtained.Based on the safety dilution method,the required air volume per unit power k at different altitudes and the comprehensive altitude coefficient considering the changes in CO emissions and control standards were derived.The re-sults show that the CO concentration of diesel vehicles increases with the increase of altitude.At an altitude of 3 172 meters the CO concentration released by diesel vehicles is about twice that in plain areas(at an altitude of 590 m).The CO al-titude coefficient of diesel vehicles in the existing specifications is obviously higher,and the measured value at an alti-tude of 3 000 m is 25.61％lower than the standard value.The air volume required for construction ventilation based on safety dilution method can be calculated in 3 sections according to altitude.The results show a significant increase in air volume required compared to those calculated by the rated power method.Based on the field test results,a calculation model was proposed for CO comprehensive altitude coefficient of diesel vehicles at different altitudes(below 2 000 m,between 2 000～3 000 m and above 3 000 m)was proposed.The CO emissions at the work surface can be reduced by 80％by installing DOC exhaust purifier.At a purification efficiency of only 60％,the calculated air volume required at an altitude of 5 000 m calculated based on the safe dilution method is only 6.59 m3/(kW·min).
万方数据
维普
