行驶档位与发动机运行工况对重型柴油货车NO_x、CO_2、CO排放的影响

INFLUENCE OF DRIVING GEAR AND ENGINE CONDITION ON ROAD EMISSION OF HEAVY DUTY DIESEL TRUCKS

使用便携式排放测试系统(PEMS)在一辆状态良好的重型柴油货车上进行实际道路排放试验,研究发动机转速、负荷、行驶档位、车速与排放的关系。结果表明:NO_x、CO_2排放速率随发动机转速、负荷的上升而增加。NO_x、CO_2、CO排放因子随档位升高呈先急后缓的降低趋势,随传动比减小呈较为线性的降低趋势;同一档位行驶时,NO_x、CO_2排放因子、排放速率均随车速的升高而增加。因此,对于此类重型柴油车辆,为降低排放,应尽量使用高档位在相应的中、低车速下行驶。

The Portable Emissions Test System(PEMS) was used to conduct actual road emissions test on a well-conditioned heavy duty diesel truck, to study the relationship between engine speed, load, driving gear, vehicle speed and emissions. The results showed that: the NOx and CO2 emission rates increased with increase of the engine speed and load, the NOx, CO2, and CO emission factors showed a trend of rapid firstly and then slowly decrease with the increase of gear, and showed a relatively linear decrease trend with decrease of the transmission ratio;when driving in the same gear, NOx and CO2 emission factors and emission rates all increased with increase of the vehicle speed;therefore, to reduce emissions, high gear should be applied in driving at the corresponding medium and low speeds.