Emission And Performance Simulation Of Turbocharged Gasoline Engine At High Altitude

With the decrease of ambient air pressure at high altitudes,the engine intake air mass declined significantly,and then the engine combustion is deteriorated,which resulting in deterioration of power output,fuel economy and emission characteristics.However,the current emission regulations for light-duty vehicle in China does not take the impacts of altitude on gasoline engines into account.Taken a 1.4 t supercharged gasoline engine as the research object,this article establish the engine and vehicle simulation model to analyze its combustion characteristic,emission characteristics and fuel consumption per 100-kilometers at different altitudes.This article have a simulation on 5 different altitudes,different altitude simulation research results showed that:the power output of gasoline engine decrease as altitude increase,so as the torque at full load of engine.Specific fuel consumption increases as the altitude rise,the thermal efficiency decrease as the altitude rise.According to the gasoline engine cylinder pressure and combustion heat release rate at different altitude,you can see that with the increase of altitude,at the same operating point,the engine maximum combustion pressure drop,burn ward,exhaust temperature rise.The simulation results also show that the HC and CO emissions of the turbocharged gasoline engine increase with the increase of altitude,NOx decrease along with the increase of altitude;under the same operating conditions,CO emissions rise along with the rising of altitude,the engine behave severe at high speed under high load,HC emissions decrease along with the rising of altitude at low speed,rise along with the rising of altitude at high speed high load,NOx emissions increase along with the rising of altitude at low speed,decrease along with the rising of altitude at high speed and high load.By establishing vehicle simulation model,the influence of different altitudes on vehicle fuel consumption per 100-kilometer was investigated the simulation results showed that at different altitudes,the constant speed fuel consumption per kilometers increase as altitude increase at low speeds,at the speed of 20 km/h,every 1000 m as altitude increase,the constant speed fuel consumption per 100-kilometers rises about 0.05 L.the constant speed fuel consumption per 100-kilometers decrease with altitude at high speed of 100 km/h,every 1000 m as altitude increase,the constant speed fuel consumption per 100-kilometers falls by about 0.2 L.