Study With Test On Cold Start Electronic Controlled High Pressure Common Rail Diesel Engine

With the advent of the energy crisis and environmental protection consciousness strengthened by the public,diesel engine is paid more and more attention by people.To reduce the incomplete combustion emission pollution to enviroment during cold start, and to meet increasingly stringent emission regulations,at the same time to decrease the diesel engine cold start cranking time,to improve the cold start reliability,and red- uce the damage for engine.The diesel engine cold start's research and improvement is a such urgenr problem.The research of this paper is to study the cold start reliability of the Electronic-controlld high-pressure common rail engine.Starting diesel engine to be reliable must have the following three basic conditions: the fuel and the air into the combustion chamber must be mixed into certain proportion combustible gas;the mixed gas must reach certain temperature;the certain temperature can be hold long enough.This paper illustrates the low temperature cold start test for a vehicle which mounted a new developed diesel engine with CPN2.2+ electronic-controlled high-pressure pump in Heihe city HeiLongjiang province ,using INCA6.0 calibration system which made by ETAS Co., in Germany. Have done some research for the cold start influence elements of this electronic-controlled high-pressure common rail diesel engine, including batteries, starter, starting fuel quantity,coolant temperature and oil characteristic.Optimized the start system like starter and etc;tested the cranking time and the emission of HC and smoke in diferent pilot injection advanced angle and injection quantity, starting fuel injection quantity,pre-heating time and rail pressure.optimized the Maps of pilot injection advanced angle and injection quantity,cold-start basic-torque and pre-heating time also. Concluded related parameters of stable and quick start for diesel engine in low temperature.Related experiments show: Oil is the most influencing factor to the cold start performance, the higher temperature the more difficult to cold start;Battery capacity's using efficiency is more important in low temperature,and in this condition big continuous Electronic's discharge ability also affects cold start;choosing good fuel is also very important ,to ensure the fuel is not wax and so it can't block pipe,this is the prerequisites for the enginestarting smoothly;There is a minnum and the best start speed,thus it can balance the minnum start power and the minnum speed;Pilot injection can rise combustion chamber temperature,main injection can fire after brief delay,so it can improve diesel engine cold start,Preheating intake air by preheater can improve effectivly starting performance and the HC emissions;Start can be more smooth ,fuel consumption and incomplete emission can be reduced by adjusting the start base torque and the start transition torque.Based on the cold-start test and the parameters adjusted,solved the problems of long cranking time,high HC emission and black smoking,improved the vehicle starting characteristics.