选取一辆符合国六排放标准的轻型汽油车作为研究对象,基于实际道路运行数据、自主开发耦合“速度与坡度”的自定义RS 803测试循环工况,在国家高原机动车质量检验检测中心轻型整车环境模拟排放实验室(海拔1 914 m)开展常温环境下油耗和污染物排放测试,通过对比带坡度与无坡度测试条件,研究分析车辆运行工况及道路坡度对轻型汽油车的油耗及污染物排放特性的影响规律。结果表明:道路坡度对车辆油耗影响较小,带有坡度与不带有坡度的RS 803循环工况下CO2排放及油耗相对偏差分别为1%和2%;但坡度对污染物排放影响较大,带坡度工况的THC,CO,N2O和NOx排放较无坡度工况分别增加27%,58%,50%和3%;油耗及CO2排放与速度、加速度和机动车比功率(VSP)呈强正相关,与VSP相关度分别达到0.55和0.53;CO排放与速度呈现极强相关性,且速度越快CO排放量越大;N2O和NOx排放与速度、加速度和VSP的相关度较低。优化高速工况燃烧策略可降低CO排放,但需平衡NOx与N2O的局部升高趋势。
To study the impact of road conditions and gradients on fuel consumption and pollutant emission characteristics of light-duty gasoline vehicles in plateau environment, a China Ⅵ light-duty gasoline vehicle was selected as the subject. Based on the custom RS 803 test cycle that was independently developed by coupling "speed and gradient" by using real-world road operation data, fuel consumption and pollutant emission tests were conducted under normal temperature conditions at the Light-Duty Vehicle Environmental Simulation Emission Laboratory of the National Plateau Motor Vehicle Quality Inspection and Testing Center (altitude 1 914 m). By comparing test conditions with and without gradients, the influences of vehicle operating conditions and road gradients on fuel consumption and pollutant emission characteristics of light-duty gasoline vehicles were analyzed. The results indicate that the relative deviations in CO2 emissions and fuel consumption between the RS803 cycle with and without gradients are 1% and 2% respectively, suggesting that road gradients have a minor impact on vehicle fuel consumption. However, gradients have a significant effect on pollutant emissions. Under gradient conditions, THC, CO, N2O and NOx emissions increase by 27%, 58%, 50% and 3% respectively compared to conditions without gradients. The fuel consumption and CO2 emissions show a strong positive correlation with speed, acceleration and vehiclespecific power (VSP), with correlation coefficients of 0.55 and 0.53 for VSP respectively. CO emissions exhibit an extremely strong correlation with speed, and higher speeds will lead to more CO emissions. N2O and NOx emissions show lower correlations with these factors. Optimizing combustion strategies under highspeed conditions can reduce CO emissions, but this requires balancing the local increasing trends of NOx and N2O.