Abstract: In order to ensure the accuracy of emission test results on the actual road of heavy-duty diesel vehicles, this article is based on the chassis testing method. A portable in vehicle emission testing system (PEMS) and a full flow dilution constant volume sampling (CVS) system are connected in series for synchronous emission testing, and the differences between in vehicle testing equipment and CVS test results are compared and analyzed. Research has shown that due to the CVS system being a full flow dilution sampling test, the mixing of dilution air and sampling gas will have a mixed average effect on the emission fluctuations of China world transient vehicle cycle (C-WTVC) transient conditions, thereby affecting the correlation between CVS emission test data and PEMS test data to a certain extent. By designing a constant speed stable operating condition test, the dilution effect of CVS can be eliminated to a certain extent, verifying the good correlation between the PEMS test results and the CVS system test results.

Key words: Heavy-duty diesel vehicles; Vehicular testing equipment; Full-flow dilution constant volume sampling system; Pollutant emissions

摘要： 为保证在重型柴油车实际道路中排放测试结果的准确性，文章基于底盘测试法，将便 携式车载排放测试系统（PEMS）与全流稀释定容取样（CVS）系统串联进行同步排放测试， 对比分析车载测试设备与 CVS 测试结果的差异性。研究表明：由于 CVS 系统是全流稀释采 样测试，稀释空气与采样气体的混合会对中国重型商用车瞬态工况瞬变工况（C-WTVC）的 排放波动产生混合平均效应，从而一定程度上会影响 CVS 排放测试数据与 PEMS 测试数据的 相关性结果。通过设计恒定车速稳定工况试验，可以在一定程度上消除 CVS 的稀释效应影响， 验证了 PEMS 测试结果和 CVS 系统测试结果有比较好的相关性。

关键词: 重型柴油车；车载测试设备；全流稀释定容取样系统；污染物排放