Research On Emission And Fuel Consumption Characteristics Of Typical Hybrid Electric Vehicle

With the deterioration of ecological environment and the shortage of oil resources,energy saving and emission reduction have become two major themes in the development of modern automobile technology.At present,the new energy vehicles are difficult to completely replace the traditional fuel vehicles for various reasons,and the latest emission and fuel consumption regulations in China are strict.Therefore,the development of hybrid vehicle technology has become the focus of automobile development Direction.In this paper,a typical hybrid electric vehicle with national V emission standard is taken as the research object.According to the latest national VI emission regulations,the emissions of hybrid electric vehicle are tested and the fuel consumption level of vehicle is calculated by the carbon balance method.In this way,the emissions and fuel consumption characteristics of Hybrid Electric vehicle in NEDC cycle and WLTC cycle are specifically analyzed.The main research contents and conclusions are as follows:（1）The difference between NEDC cycle and WLTC cycle is compared.The results show that compared with the NEDC cycle,the WLTC cycle test time is longer,and the driving speed is faster,and the change of speed and acceleration is more drastic.As a result,the working condition of WLTC cycle is more in line with the actual road demand in people’s travel.（2）The emission performance of hybrid vehicle under NEDC test cycle and WLTC test cycle with GB VIb limit is compared.The results show that the HC,CO and NOx corresponding to the nedc cycle and the wltc cycle of hybrid vehicles meet the GB VIb.Although the value of PN is exceed the GB VIb,the transition limit value(6×10¹²#/km)is satisfied at the present stage（before July 1,2020）.（3）The transient emission performance of hybrid vehicle is analyzed.The results show that the emission pollution of CO,HC and NOx is more serious in the cold start-up phase of the hybrid vehicle,and the emission of CO is higher in the high-speed phase,and the emission of PN is mainly concentrated in the frequent start-up and stop phase of the engine,and the emission pollution of other conditions is lower.（4）The effects of speed and acceleration conditions on the emissions and fuel consumption of hybrid electric vehicles are studied.The results show that,with the increase of speed,the CO emission factor is increased,and the HC emission factor is decreased,and the NOx and PN emission factors are increased first and then decreased.The fuel consumption level increases gradually with the increase of speed,and the fuel consumption of NEDC cycle and WLTC cycle reached peak in the maximum velocity range.With the increase of acceleration,the CO,NOx and PN emission factors,and the HC emission factors are increased first and then decreased.As the acceleration increases,the fuel consumption level is increased first and then decreased,and the fuel consumption of NEDC cycle and WLTC cycle reached the peak value in the acceleration range of 0～0.5m/s².（5）The isokinetic fuel consumption test was carried out for the hybrid vehicle.In the speed range of 20 km/h～160 km/h,the oil consumption of the whole vehicle is tested,and the optimum economic speed range of the hybrid vehicle is 60 km/h-80 km/h.This paper studies the emission and fuel consumption characteristics of typical hybrid vehicles,which provides data support and guidance for the future development of hybrid vehicles,and plays a good role in promoting the development of hybrid vehicle technology.At the same time,it also makes contribution to the cause of energy conservation and emission reduction.