Vehicle Emission Characteristics Studied

To know the trend of the automobile's emission factors varying with the velocity and load. In the article, we use the dynamometer to imitate the vehicle's constant velocity driving in actual road. In the three conditions, we measured Flyer EFI car's emission consistency separately, then calculate the emission factors (g/km). In the two conditions of the identical load, different shift and different load, identical shift, we dealt with the data, then made the analysis, so that to get the trend of the automobile's emission factors varying with the velocity and load well. For example, in the condition of empty-load and the 4th shift, we can use the least square method toformulate the CO,HC ,NO_x and total emission factors with the velocity. In the result, we cansee that when the velocity is 95km / h, the total emission factors are in the minimum. From the analysis of the data, we can also conclude that when the test car is driving with the velocity of 70km / h, the total emission factor is in the minimum in the conditions of mid-load and all-load.From the analysis of the article, we can make a conclusion that the automobile's emission is determined by the matching of the engine, the catalyst and the transmission. For example, in the empty-load condition, to make the HC in the minimum, we can calculate that the velocity should be 65km / h in the third shift and the velocity should be 100km / h in the 4th shift. Others, we can infer that the application of CVT can eliminate the increasing of the emission by shift's varying, and keep the emission in a low condition. Moreover, the emission regular can also be the theory of highway circumstance evaluation.