张旺^1,2，刘俊霆^1,2，贾春富^1,2，刘强^1,2，吴撼明^1,2，李振国^1,2*

1.中汽研汽车检验中心（天津）有限公司，天津 300300；

2.中国汽车技术研究中心有限公司移动源污染排放控制技术国家工程实验室，天津 300300

摘要：针对发动机进、排气系统漏气影响碳平衡偏差问题，分别对进、排气系统不同管路漏气进行万有特性、稳态循环、瞬态循环试验，测试和分析碳平衡偏差随漏气位置和漏气量的变化规律。结果表明：压气机后进气管或排气管路漏气时，测试工况点的碳平衡偏差均为正值，其中压气机后进气管漏气的最大碳平衡偏差为35%、排气管路漏气的最大碳平衡偏差为1.7%；压气机前进气管路漏气时，碳平衡偏差为负值，最大为-6.3%；碳平衡偏差的绝对值随进气系统漏气量的增加而增大，但排气系统漏气量不影响碳平衡偏差。碳平衡偏差主要受进气管漏气影响，当碳平衡偏差超过3%时，若碳平衡偏差为正，应优先排查压气机后进气管路；若偏差为负，应优先排查压气机前进气管路。

关键词：碳平衡；碳平衡偏差；发动机进气和排气系统漏气

Abstract：In order to study the influence of air leakage from engine intake and exhaust system on carbon flow, the universal characteristic, steady-state cycle and transient cycle tests are carried out for the air leakage of different pipelines of the intake and exhaust system respectively, and the carbon flow deviation with the change law of air leakage position and amount is tested and analyzed. The results show that the carbon flow deviation of the test condition points is positive when the air is leaking from the intake pipe or exhaust pipe after the compressor, the maximum carbon flow deviation is 35% when the air is leaking from the intake pipe after the compressor, and 1.7% when the air is leaking from the exhaust pipe; the carbon flow deviation is negative when the air is leaking from the intake pipe before the compressor, and the maximum is -6.3%; The absolute value of the carbon flow deviation increases with the increasing of the air leakage of the intake system, but the air leakage of the exhaust system does not affect the carbon flow deviation. The carbon flow deviation is mainly affected by the air leakage from the intake pipe, when the carbon flow deviation exceeds 3%, the air inlet line after the compressor shall be checked first if the carbon flow deviation is positive, the air inlet line before the compressor shall be checked if the deviation is negative.

Keywords:carbon balance; carbon flow deviation; air leakage from engine intake and exhaust system