Research On The Actual Road Emission Characteristics Of Heavy-duty Vehicles Based On PEMS

China has become the world's largest motor vehicle production and sales for eight consecutive years,motor vehicle pollution has become an important source of air pollution in China,is an important cause of fine particulate matter,photochemical smog pollution,motor vehicle pollution prevention and control is becoming increasingly urgent.In recent years,the emission standards of motor vehicles have been continuously improved,but the number of motor vehicles in China is large,and there are still some problems in the emission supervision.At present,the emission regulation of heavy diesel oil mainly uses fixed cycle to evaluate the emission on engine bench.However,due to the use of the vehicle on the road environment,the operating conditions of the engine are quite different from the bench,which will cause the engine on the bench to meet the emission requirements,but to the vehicle emissions exceed the standard risk is greater.Based on the vehicle PEMS,this study conducted a detailed study of vehicle emissions on the actual road.The whole Lane emission test system,data processing method,power window method and NTE method are introduced in detail.The typical application of heavyduty diesel engine,the whole-lane emission of bus,dump truck and tractor are measured and analyzed in detail.The effect of increasing heat preservation material to improve the temperature of SCR upstream exhaust is studied.The relationship between instantaneous working conditions and road emission is studied by using the characteristic parameters of instantaneous working conditions such as speed,acceleration and specific power.The influence of high altitude on engine emissions was studied.The effects of different altitudes on engine bench were studied.The emission of two altitudes were compared.