Simulation On Combustion Process Of 16V240ZJE Diesel Engine

Along with oil resource day-by-day depletion and environmental pollution day after day aggravating, as well as emissions laws and regulations even more strict, internal combustion engine's development is facing more and more stern challenge. The diesel engine has the characteristics of high efficiency, the energy conservation and the big torque, but it's high NOx and PM discharges restrict its development. Therefore, taking the effective action to reduce diesel engine's harmful emissions and to promote its application, has the important theory significance and the actual value to the enhancement of environmental pollution and the postponement of energy crisis. Diesel engine's combustion process couples directly with its prime task characteristic, power, efficiency and emissions, as well as part's machinery and heat load, noise, vibration and so on. Therefore, it must first work hard in the combustion process's improvement and optimization to improve and consummate the diesel engine's overall performance and certain partial characteristics. To research combustion's process research, besides the traditional testing method, the numerical simulation established in the experimental foundation is a powerful measure.This dissertation has elaborated the internal combustion process's three dimensional computation model and the combustion theory. It has also carried on the concrete analysis on the gas phase rapids model, the oil atomization model and the internal combustion model theoretically. By the three dimensional simulating software FIRE, we carry on the numerical simulation on the air current moving process, the atomization process and the combustion process of the 16V240ZJE diesel engine. By simulating, such things have been demonstrated in detail, as the flow field, the pressure field and the temperature field as well as the emission density's distribution.Using FIRE, this article has mainly carried on the exhaustive analog computation and analysis of 16V240ZJE diesel engine's combustion process:Regarding the same chamber, different spraying parameters, like the advance angle of fuel, the nozzle hole's cone angle, the nozzle diameter as well as the convexity's height, were investigated. The following solutions were obtained:①As the advance angle of fuel retarding, the NOx reduces. But it's easy to cause the combustion not to be full, the soot increasing, the fuel consumption's rate elevating. Through the generalized analysis, the best advance angle of fuel is 13°BTDC.②Nozzle hole's cone angle influences fuel's distribution in the cylinder. whenα=165°, the oil's descent point is transited arc place of the cylinder's sidewall, which's advantageous for emissions. ③If the nozzle diameter is small, the oil tie's penetration is a big way, which's easy to cause the oil to hit the wall; whereas if the nozzle diameter is big, the oil tie's penetration is small, which's easy to cause the combustion not to be full. Through the analysis, d=0.35mm is designated, at which the combustion is full, and the emission is few.④Convexity's height influences oil's distribution in the cylinder. If it stretches out too small, the oil ties easily sprays to the cylinder cover's bottom, which causes the combustion isn't full and the emission increases. If it stretches out too big, the nozzle is easy overheated. By analysis,the best convexity's height is 3mm.Further deep research to the combustion process has been forecasted finally.