Cold Start Emission Characteristics of Diesel Engine at High Altitude and Low Temperature 2022-01-0563

The diesel engine is the core in the field of engineering machine power plants. While both at home and abroad for the cold start of diesel engine, the transient emission characteristics below 0 °C and above 2000m is almost a blank. Therefore, aimed at high altitude and low-temperature environment emission characteristics of cold start, this article has carried on the systematic analysis and research. In this paper, a simulation test system for the cold start of the diesel engine at low temperature at high altitude is established. The cold start experiments of a heavy diesel engine at different ambient temperatures (10°C, 0°C, -10°C and -20°C) and different altitudes (0m, 3000m, and 4000m) is carried out. In this paper, the gas emission of the diesel engine during the speed-up period of cold start is studied. The main conclusions are as follows: (1) With the increase of altitude and the decrease of ambient temperature, HC emission of the diesel engine during cold start speed-up period is obviously increased, and NOx emission increases gradually. HC emission mainly concentrated in the cycle with high cylinder pressure and increased significantly when the rotation speed fluctuated violently during the starting process, The NOx emission mainly occurs after the cycle of high pressure in the cylinder. (2) At 3000m and below -10°C, the total HC emission at cold start is 18~1280 times that at 0m and 10°C. The total NOx emission rises to 15~190 times.