Research On Spray Nozzle Inner Wall Quality For Effects Of Emulsified Diesel Engine Performance

Nozzle, which is the core component of the engine, its inner wall surface quality directly related to the fuel atomization effect and the nozzle flow coefficient, fuel spray shape and degree of micronization, and then it has greater impact on power performance, fuel economical efficiency and emissions of the engine, so studying the effect of nozzle inner surface quality on engine performance has important significance. Spray nozzle hole has smaller diameter and it form the cross hole connected with the inner cavity. The conventional polishing process is difficult to finish the smaller hole, which has become a bottleneck problem to further improve the inner wall quality of nozzle on engine. For that reason this paper adopts a new finishing machining technology-Liquid magnetic abrasive finishing machining technology, and carry on the theoretical analysis and experimental research on the affects of the performance of emulsified diesel engine with Inner wall quality of processed nozzle.This topic comes from the NSFC (Natural Science Foundation of China)(51075294) and Shanxi Province Natural Science Fund Projects (2010011034-1)"the research on the liquid magnetic abrasive tool honing hole technology", the main research contents are as follows:1) According to the rheological properties of liquid magnetic abrasive tool, with the action of a magnetic field, flexible grinding layer can be formed along the wall of inner hole. Develop a new type of extrusion honing device of smaller holes, establish the material removal model of liquid magnetic abrasive finishing the smaller hole, and analyzed the influence of the inlet pressure, processing time, magnetic field intensity and the size of abrasive particle for the finished surface quality, Sequentially optimize the main process parameters of finishing the smaller hole.2) Analyze the different inner wall quality of nozzle (the inlet corner radius and the roughness of inner wall) on the influence of fuel flow in the hole, average speed and mass flow rate of outlet the atomization effect through the three-dimensional fluid software. With the increase of nozzle inlet fillet radius, negative pressure area became smaller inside the nozzle, velocity is well-distributed, average velocity and mass flow rate is getting higher in outlet, nozzle flow coefficient increased; With the inner wall roughness value of Spray nozzle change in0.4μm to0.8μm, the average velocity and mass flow rate of outlet changes little, and when the roughness value is1.6μm, the average velocity and mass flow rate of outlet separately falls8%and7.5%comparing with Ra is0.4μm.3) On the QBZL4100engine of burning emulsified diesel, by changing the nozzle with different surface quality, perform the experiment of Performance Testing on the engine, the results prove that:the nozzle with better surface quality can improve the average pressure and temperature in cylinder; power Performance improve and fuel consumption slightly drop at the same time; The emission of HC,CO and PM has dramatic decline, Especially under the high speed and high load condition, the biggest drop is50%for the emission of HC,PM.71.4for the emission of CO, the emission of NOx has a slight increase.Through the method of theoretical analysis, numerical analysis and experimental research, Research the influence of engine performance with inner wall surface quality of spray nozzle. Results indicate that inner wall surface quality of nozzle is improved, the engine performance has a great improvement, which will do great significance on studying the subject of energy conservation and emissions reduction of engine.