Experiments of Load Effects on the NOx Emission Characteristics of an Euro VI Heavy Duty Vehicle

Abstract

Abstract. Load experiment (0%, 50%, 100% load) was carried out on a heavy duty diesel engine vehicle which meet EU/VI exhaust emission standard and the vehicle was drove on the heavy chassis dynamometer based on C-WTVC cycle. During the test period, the NO, NO 2 , N 2 O on the exhaust were analyzed by sophisticated measuring equipment. The results show that the NOx emission value on all 3 loads satisfy the EU/VI standard. As load rise up, the concentration of NO, NO 2 before/after Selective Catalytic Reduction system increase too. The NOx conversion efficiency under the 3 loads are 89%, 92%, 92% respectively. While the NO 2 concentration under the whole test cycle is low, the maximum can up to 19.5ppm under full load condition. The N 2 O concentration was effected by exhaust temperature and the load indirectly impacts the NO 2 concentration through the temperature. The concentration of N 2 O is positively related to load and driving condition, the N 2 O concentration increases when the load and speed rise up. During the 100% full load, the NO, NO 2 and N 2 O account of the total NO x is about 84.6%, 1.8% and 13.6% respectively.