关键词: 冷启动；PEMS；重型柴油车；污染物排放

Abstract: In order to analyze the emission characteristics of various pollutants under the condition of cold-start of heavy-duty diesel vehicles, 5 heavy-duty diesel vehicles were selected for actual road vehicle testing. The test results show that, NOX accounts for a relatively large share in the cold start phase, while CO and PN account for a relatively small share in the cold-start phase, from the perspective of cumulative emissions. The specific emissions of NOX and CO during the cold start phase are relatively large, from the perspective of specific emissions. However, the specific emission of PN during the cold start phase was not always the larger one. Comparing the changes in the concentration of various pollutants before and after the cold start, it is found that NOX has a clear downward trend before and after the cold start, while the change trend of PN and CO is not obvious, indicating that the situation of the vehicle itself play a role in the emission of the PN and CO. It should be paid more attention to the NOX and CO emissions of vehicles during the cold start phase in the future.

Key words: Cold-start phase; PEMS; Heavy-duty diesel vehicles; Pollutants emission