The Separation And Optimization Analysis Of Combustion Noise With Electronic Injection Diesel Engine

The combustion noise of the diesel engine was studied in this paper from the following aspects: its mechanism, characteristics, influenced factors, controlled methods and its present and future research at home and abroad. Based on the research, DENSO ECD-U2 high pressure common rail electric system and the pilot injection technology were adopted to control the combustion noise of the diesel engine. A basic control method and its realization of the high pressure common rail diesel Engine was proposed according to the burning process and exhaust requirement of the diesel engine. The fast starting and smoothly running of the diesel engine was achieved by the calibration of the engine's injection timing MAP and the goal common rail pressure MAP.The experiments about the effect that the one-shot injection and pilot injection had on the combustion noise were made. Moreover the effect the parameters of the pilot injection having on the combustion noise was analyzed too. The conclusion was that by adjusting the pressure of common rail, the main injection timing, pilot injection timing and pilot injection volume, the engine noise could be well reduced in different speed and load, and at the same time, the NOx and smoke could meet the requirement, too; The pilot injection was more effective to the low speed and low load working condition's noise reducing.The recognition and separation of the noise sources of the diesel engine was also studied by using ICA. And FastICA was realized in MATLAB to separate the different noise sources from the experiment data of the varying engine working conditionsThis paper gives the relationship between the signals of the cylinder pressure, the heat release rate and combustion noise. Also the spectrum of cylinder pressure is done in MATLAB environment. Based on these, a conclusion could be made according to the experiments' data, which is adopting appropriate pre-injection strategy, can reduce the highest cylinder pressure, pressure rise rate and the heat release rate effectively. As a result, the combustion condition of the diesel engine was improved; the medium and high frequency cylinder pressure was also decreased. Consequently, combustion noise of the diesel engine was reduced, and then the noise of the diesel engine did so.