Research On The Emissions And Fuel Consumption Characteristics Of Light-duty Gasoline Vehicle At High Altitude

The automobile industry has become one of the pillar industries of China's industry,and in recent years,car ownership is an explosive growth,followed by the motor vehicle exhaust pollution is the problem.For high-altitude areas with large-scale car ownership,there is currently no restriction on the development of emission regulations.In order to promote the development and implementation of standards as soon as possible,it is necessary to study the fuel consumption and emission characteristics of light vehicles at high altitudes.This paper first determines the drag coefficient by the glide test of the light gasoline vehicle.The test selected a number of different elevations,ranging from 21m to 5000m.Each test is carried out according to the standard enough times to ensure the accuracy of the test data.Finally,the skidding data obtained are processed according to the average time and then the average resistance method,and the SAE and ECE two kinds of sliding resistance elevation correction methods are selected and compared with the experimental data.The results show that the SAE method is more suitable for each altitude and speed,and can be used in the follow-up work.After that,a simulation model of the gasoline engine for the test vehicle was established and corrected by external characteristics.The results show that with the increase of altitude and the increase of the inlet temperature,the P_e and T_e of the external characteristic curve are greatly reduced and the fuel consumption rate is increased.The maximum burst pressure P_maxax of the gasoline engine is reduced,the combustion start point is delayed,the combustion duration is shortened,the indicated efficiency is decreased,the effective efficiency is also decreased,and the effective efficiency is directly related to the speed.BSCO and BSHC show rising trend of emissions,and the higher the elevation,the greater the slope of the rising curve.The BSNO_x decreases with the increase of altitude,and the maximum decrease in the maximum torque point and the maximum power point is the largest,and the variation range is low at low speed.Finally,a complete vehicle model was established for a light gasoline pilot vehicle,and a high altitude fuel consumption and emission study were carried out using the established vehicle model.Then,the fuel consumption test and the laboratory discharge test were carried out accordingly.Through the fuel consumption test found that vehicle fuel consumption with the elevation of the basic show a downward trend,at the same time,also affected by temperature.By comparing the simulation results and experimental results,it is found that the pollutant changes are consistent.With the rise of elevation,THC,CO emission factors show an increasing trend,and the higher the altitude,the greater the increase.The decrease of NO_x at low altitude is lower than that at 0 m,and increases at 0 m above sea level,and the higher the altitude is,the higher the increase is.