Research Of Real Driving Emission For Light-duty Vehicles In China

Faced with serious environmental pollution resulting from vehicle emissions,governments have launched a series of mandatory emission regulations,in which the emission limits are associated with a standard cycle.There is substantial evidence that the standard cycle cannot cover the operating conditions under real driving conditions.“Volkswagen emission incident”urged European Union to envisage the defects of the present laboratory emission test,and speeded up the introduction of the Real Driving Emission?RDE?test procedure.This thesis,in strict accordance with the latest EU Real Driving Emission?RDE?test procedures,measured the emissions emitted from seven vehicles with different brands,different emission standards,different fuels and different mileage on the actual road of Beijing and obtained 42,000 emission test data.CO₂ moving averaging window method and power binning method were applied to analyze the real driving emission test results,respectively.Emission factors in line with conformity factor for these vehicles are presented in this thesis as well.Test results of diesel vehicles show that:CO and THC emission factors for RDE,NEDC,FTP75 and WLTC are lower than the applicable emission limits,while NO_X emission factors for all conditions other than NEDC exceed applicable emission limits,up to 7.09 times.The biggest gap between RDE and the laboratory cycle comes from NO_X emission.Test results of gasoline vehicles show that:NO_X emission factors of RDE tests for all vehicles except one do not exceed applicable limits.However,the emissions behavior of CO is relatively bad,with emission factors exceeding the limit up to 3.61times.The biggest gap between RDE and the laboratory cycle comes from CO emission.The emission behavior of the hybrid vehicle is in good condition,none of emission factors exceed applicable emission limits.