Optimization Method of Low Exhaust Temperature Emissions of City Buses Meet China V$1;

摘要

Emission problem of city bus running under low speed and low load is gradually becoming a research hotspot. The city buses were taken as research object in this paper. Emissions of two city bus were tested on heavy duty chassis dynamometer under CCBC. Test results showed that under low speed and low load conditions, because of low transformation efficiency of SCR, NOx emission of engine was serious, but the NOx emission of test vehicle can be significantly reduced by using the method of fixing heat insulating material on the exhaust pipe and ECU calibration according to low speed and load conditions of city buses. Test results also showed that after rehabilitation, emission reduction effect of NOx was above 40%, other emissions do not deteriorate significantly.