The Injector Matching Test Research Of NC4110Z-15Diesel Engine

Lacking of energy and the pollution of environmental become two big problems of theworld facing. saving energy resources， protecting the ecological environment anddecreasing pollution have become the common consciousness. Therefore, every countrysets down stricter and stricter rules on the amount of the harmful waste gas emission by theengines. Our country also set out imperative standards on the limitation of emission gas bythe diesel engines used in vehicles. vehicles．According to the standard，the diesel engineshould achieve the emission target which is equal to the standard of EuroⅡsinceSeptember1,2004. But now diesel engine is facing the challenges of NOx and sootemission because of the more and more stricter regulations. Because of this, optimizing itscombustion is very necessary. Fuel injection system is the key part to control thecombustion of the engine, as the important component of the diesel fuel supply system, theinjector makes the decisive functions to the performance and emission of the diesel. Thethesis tests on NC4110Z-15diesel, investigate the influence of the structure parameters ofthe diesel to the performance of the diesel,such as the number of injection holes, thediameter of injection nozzle, protruding distance, opening pressure and injection angle,through the whole engine performance matching experimentations and then analyse theresults of the matching experimentations, finally reach to the conclusions. And in the end,optimize the parameters of the injection system to improve the diesel engine performance.The principal results of this thesis were listed as follows. It’s found from the experimentsthat the proper choice of injector protruding distance can attain a better balance betweenfuel economy, torque, NOx and soot emission; the injector with smaller nozzle diameter isless dependent on the gas flow of in cylinder, and is good to improving the performance ofdiesel engine at low speed; Increase the number of holes, to improve fuel atomizationquality to improve mixture uniformity, burning more concentrated in the combustionchamber, in favour of complete combustion but sprayed too many holes, more fuel isburned at the top of the piston, not easily lead to high in-cylinder temperature, nitrogenoxides and soot generated more; Appropriate to increase the injector opening pressures canreduce the rate of fuel consumption and smoke, NOx emissions increase, increase openingpressure can increase injection rate, increase speed burning combustible mixture of unitsduring the period of time, of improved economic and power; Nozzle angle too big and toosmall would not be conducive to combustion and emission characteristics, only reasonablechoice nozzle angle size can get better fuel properties and emission characteristics of low.