Research on evaluation of diesel vehicle off-cycle NOx emissions comparing with the traditional emission evaluation method for vehicle diesel engines

an off-cycle NOx emission evaluation method was proposed. According to the test-bed measurement of the work-based emission intensity map of a diesel engine with a SCR system coupled to the distribution of the real-time operating conditions of the vehicles. The calculation of the emission data of the road vehicle under real-time operating conditions was performed

thus realizing the estimation of the real-time emissions from the road vehicle without using portable emissions monitoring system(PEMS)

In addition

the whole process of testing NOx work-based emission intensity map on the test bed was also introduced in detail

and the on-road NOx emission prediction of in-use vehicles was conducted based on the NTE method

while verified the feasibility of this method and the advantages of monitoring the actual emissions from vehicles. At the same time

it also pointed out that the existing NTE method or work base window method could not cover the high emission area in which the vehicle actually operated. This method provides a new technology choice for the relevant regulating agencies to monitor the real-time emissions of vehicles.