Краткое описание

An on-board system capable of determining ppm level emissions of carbon monoxide (CO), total hydrocarbons (THC), and nitrogen oxides (NO_x) is developed. The data acquisition allows for the simultaneous retrieval of engine and vehicle parameters to calculate on-line mass based time resolved emissions that can be quickly linked to relevant parameters of the emission control system. The on-board system is validated by 160 comparative measurements on three Constant Volume Sampling (CVS) chassis dynamometers. The tests are executed on a Heavy Duty diesel truck and on three modern Light Duty vehicles. The differences in emissions are generally below 10% until 0.02 g/km. A real life performance evaluation is executed on a Eminox/Johnson Matthey Continuous Regenerating Trap (CRT) equipped VanHool A308 city bus. All tests are performed with, and without, CRT. The CRT reduces, almost eliminating, PM emissions to over 90% CO and THC to over 85%. It is found that the resulting THC ppm concentrations yield mass emissions as low as 0.03 g/km. No significant effect of fuel sulphur content was found in the tests without CRT.