Study Of The Impact Of Multi-injection On The Characterisitic Of The Combustion And Matching In Cylinder Of Diesel

With the advancement of technology and development, consumption of oil and gasand other energy constantly increase, people put forward high requirements about theutilization of energy economy.Achieving segmentation by high-pressure common rail fuelinjection diesel engine is precisely to meet this requirements,the research about using thepressure common rail diesel split injection to improve power performance and economy isseldom done by by scholars at home.With the increasing of energy consumption and highperformance requirements for diesel power,the need for further in-depth study anddiscussion for the split injection cylinder combustion becomes more necessary.Firstly, Building a132mm bore single-cylinder diesel engine in order to achieveinjection segments through a common rail fuel. Analyzing the connection between thedifferent parameters of the segmentation injection(the injection quantity and the injectioninterval between pilot injection and main injection and the injection timing) and dieselengine dynamic performance, at1500r/min,1800r/min at different speed.These conclusionscomes:1) the appropriate amount of pre-injection diesel engine can improve dynamicperformance,with the increasing amount of pre-injection, the indicated power of dieselengine first increases and then decreases. Because temperature and pressure in the cylindercan be increased by heat released by the preliminary injection，the pilot injection have someeffect on the ignition of the main injection.so the indicated power can be improved.2)Theinterval between pilot injection and main injection have a significant impact on thecombustion characteristic.With the increasment of the interval,the combustion pressure hasincreased,the peak constantly after the shift,increasing the main pre-spray interval，thus thecombustion noise can be reduced significantly.3) The swirl also has an important impact onthe combustion characteristic, compared to the eddy current analysis shows that more thanone cylinder combustion, the swirl can promote the efficiency of mixing of oil and gas,thereby improving diesel combustion efficiency, enhance the performance of diesel power.Secondly, building a132mm bore single-cylinder diesel engine combustion systemsimulation model by using the software FIRE. Complete the verification model checking in1800r/min,100%load conditions point. exploring relationships between the injector sprayholes and the speed,to match the number of with swirl ratio in1600r/min,1800r/min,2000r/min,2200r/min. completed six holes,8holes and10-hole injector matchingsegmentation parameters and swirl ratio of injection,meanwhile research the optimization advance angle and optimum the split injection parameters at1600r/min,1800r/min,2000r/min,2200r/min,four different load speed (50%,100%) properties. Conclusions:1) At thesame speed, the indicated power decreases with the increase of the number of the nozzleholes, six holes plan achieve the highest indicated power.2) The same number of nozzleholes, the best indication of the diesel engine corresponding to the power swirl ratiodecrease with the increase of the engine speed.3)The engine’s low-speed all load conditions,the maximum indicated power decrease as the engine speed increases, the advance angleof main injection is gradually increasing. The best interval corresponding to the maximumindicated power increases as the load increases.