In this paper, the real driving particle number (PN) emissions from two China-6 compliant hybrid electrical vehicles (HEVs) were measured using a certification-level portable emission measurement system (PEMS) and strict adherence to the regulatory procedures for real driving emission (RDE) testing. The results show that the trip-averaged PN emission factors for the port fuel injection (PFI) HEV and the gasoline direct injection (GDI) HEV were 1.15E+12 and 1.71E+12#/km respectively, much higher than the engine-only counterparts and failing the existing RDE limits. Enriched air-fuel mixtures and probably lowered catalyst conversion efficiencies as a result of more frequent engine stop-and-goes of the HEVs are found to be the underlying reasons for the extra PN emissions. The test results also suggest the necessity to amend the power management strategy currently widely used in HEVs to deal with the PN issue.

中文翻译：

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符合国六标准的 PFI 和 GDI 混合动力汽车的实际行驶粒子数 (PN) 排放

在本文中，使用认证级便携式排放测量系统 (PEMS) 并严格遵守实际驾驶排放的监管程序，测量了两辆符合国六标准的混合动力汽车 (HEV) 的实际行驶颗粒数 (PN) 排放。 (RDE) 测试。结果表明，进气道燃油喷射（PFI）HEV和汽油直喷（GDI）HEV的行程平均PN排放因子分别为1.15E+12和1.71E+12#/km，远高于发动机-只有对应物并且没有达到现有的 RDE 限制。发现由于混合动力汽车更频繁的发动机停停而导致的浓缩空气燃料混合物和可能降低的催化剂转化效率是额外 PN 排放的根本原因。