高海拔地区轻型车排放特性研究

More than 65% of China territory is over 1 km above sea level. The vehicle actual emission characteristics at high altitudes have a large difference from the emission results for vehicle type approval during to different atmospheric environment conditions. Study on the vehicle emission characteristics at high altitudes has important theoretical significance and scientific value for revealing the status of motor vehicle emission at high altitudes and development of effective vehicle emission control measures at high altitude environment..In this project, light duty vehicle coastdown resistance will be measured at about 10 different altitudes within 0-5000m altitude range, and the coastdown resistance curve and coastdown resistance coefficients will be obtained by using numerical analysis methods; At the same time, the emission characteristics of light duty gasoline vehicles and light duty diesel vehicles under actual road conditions will be measured using SEMTECH-DS and ELPI; Based on the analysis of the main influence factors on the light duty vehicle emissions and vehicle road coastdown resistance at high altitudes and based on the analysis of atmospheric conditions, the standard for light duty vehicle emission test conditions at high altitudes will be developed, and based on this high-altitude emission test conditions, the emission characteristics of light duty gasoline vehicles and light duty diesel vehicles will be measured in the high-altitude environment simulation lab to simulate different conditions of atmospheric pressure, temperature and humidity. Based on the light duty vehicles’ emission characteristics under actual road conditions and their emission characteristics tested in the high-altitude environment simulation lab at different altitudes, the impact mechanism of the high altitude conditions including atmospheric pressure, temperature, humidity and Light intensity on the emission characteristics of light-duty gasoline vehicle and light-duty diesel vehicle will be analyzed.

我国高原区域广阔，高原环境下机动车排放与型式认证工况排放差别较大。研究高原地区机动车排放特性对揭示高原区域机动车排放状况及制定有效的机动车污染控制措施具有重要理论意义和科学价值。本课题拟在0-5000m海拔范围内，选择10个左右的不同海拔地区进行轻型车道路滑行阻力测定，运用数值分析方法拟合汽车滑行阻力曲线，得到滑行阻力系数；同时，利用SEMTECH-DS和ELPI车载排放测试设备测量轻型车实际道路行驶条件下排放特性；基于高海拔环境下轻型车排放特性及道路滑行阻力主要影响因素及高海拔条件下机动车行驶的大气环境条件分析，制定高海拔条件下机动车排放测试试验条件规范；依据此高海拔环境机动车排放测试试验条件规范，采用海拔环境仓模拟不同海拔环境对轻型车排放特性进行试验研究；通过对不同海拔条件下轻型车实际道路排放特性及海拔环境仓轻型车排放特性分析，揭示轻型汽油车及轻型柴油车排放及油耗随海拔环境变化规律。

通过实际道路测试，完成了不同海拔条件下轻型车道路滑行阻力测试研究，得到了不同海拔条件下轻型车道路行驶阻力特性、修正方法及计算函数；基于海拔仓实验室试验测试和实际道路排放测试，揭示了不同海拔条件下轻型汽油车及轻型柴油车实际道路排放特性，包括气态污染物和颗粒物排放特性，颗粒物的数量排放浓度和粒径分布特性；通过对海拔仓实验室设备测试及影响因素研究分析，制定了高海拔环境下机动车排放测试试验条件规范；通过高海拔环境下轻型车实际工况排放测试及海拔环境仓轻型车排放测试结果，揭示了轻型车排放及油耗随海拔环境变化规律。基于本项目轻型车滑行阻力、燃油经济性和排放特性研究结果，研究影响实际RDE试验结果的因素，包括海拔高度、环境温度、驾驶行为、等对实际道路排放（RDE）实验结果的影响，为研究和制定国六轻型车标准中RDE的试验流程，完善相关数据处理方法提供了技术支持。