使用光学电子显微镜,对比分析了新喷油器和积碳喷油器的喷孔形貌.图像表明:喷油器喷孔积碳后,喷孔出口有明显的不规则积碳,喷孔圆度发生变化,喷孔结构改变;喷孔内部粗糙度增大,有少量不规则积碳.利用单缸柴油机试验台架,分别使用新喷油器和积碳喷油器进行了外特性燃烧试验,分析了燃烧特性的变化规律.试验结果表明:喷油器喷孔积碳后,柴油机功率、扭矩下降,小时油耗、燃油消耗率增大,发动机动力性、经济性下降;由于积碳影响雾化质量,导致燃烧状况变差,缸内压力有所下降,同时造成滞燃期增长,预混合燃烧阶段放热量增多,压升率与放热率峰值明显增大,燃烧过程粗暴,排气温度升高.%The nozzle morphology of new injector and carbon deposition injector were compared and analyzed by using the optical electron microscope.The image revealed that there are obviously irregular deposit in nozzle external,nozzle hole roundness and nozzle structure were changed,nozzle internal roughness increases with a small amount of irregular deposit.The combustion experiments of external characteristics with new injector and carbon deposition injector were carried out in a single cylinder diesel engine test bench.The change of combustion characteristics was analyzed.The results showed that diesel engine power and torque were decreased,and the fuel consumption and specific fuel consumption were increased after injector nozzle deposited,dynamic property and fuel economy decline.The combustion performance becomes worse due to the effect of deposit on atomization,and the cylinder pressure decreases.As the ignition period delay,heat release in premixing period increases,maximum pressure rise rate and heat release rate increase significantly,the combustion process becomes rude and exhaust temperature increases.
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