| With the rapid development of shipbuilding industry,the application of high power engine is becoming more and more.As the core part of the engine,fuel injection system is responsible for fuel transfer and injection.Under the demand of increasing power,the range of fuel injection used by the injector is increasing.The injection law and fuel injection amount of injector directly affect the combustion in cylinder,and ultimately affect the dynamic performance of engine.So it is very necessary to test the injection characteristics of this kind of large injection injector.In this paper,the injection law test method is selected for the high power Marine injector.Based on the constant volume method,the sound velocity measurement is introduced to build a platform suitable for the overall injection law test of the target injector.Based on the principle of momentum method and with the introduction of back pressure chamber,the single-hole injection law test device of porous injector is designed.Before the test experiment,the signal conditioning and data analysis were adjusted,and the target signal was processed with an anti-Chebyshev low-pass filter with a low cut-off frequency of 5khz.Before the test,confirm the installation position of the pressure sensor and the measurement range of the test cavity.When the back pressure in the cavity is 2MPa,a more reliable oil injection law curve can be obtained.The ef S-IFR 6000 test equipment was used to test the injection law of the injector.After the adjustment of the instrument,the measuring instrument and the control equipment fit perfectly on the overall injection law curve,and the measurement accuracy can be accurate to about 10 mg when the injection volume test range is 0-3000 mg,which can be considered as reliable.This topic uses two kinds of injection law measurement device designed to test the overall injection law and single hole injection law of the target injector,and the injection strategy adopts single injection and multiple injection.Injection pressure and injection pulse width directly affect the shape of injection law curve,peak injection rate and injection duration.In the case of multiple injection,the pressure fluctuation of the storage chamber at the nozzle after injection decreases the injection delay of the main injection,and the injection law curve will fluctuate.The single-hole injection law testing device was used to explore the influence of back pressure on the injection law.Under the same injection condition,the increase of back pressure inhibits jet diffusion of the jet hole to a certain extent,and the oil beam concentrates on the force sensor to improve the peak injection rate.The same injection conditions were ensured when the uniformity of jet holes was explored.It can be seen from the obtained injection rule curve that the injection rule curves of 10 jet holes basically coincide with each other in this condition,and the fitting degree is high.After the injection pressure and pulse width were changed,the curve consistency was still very good,which indicated that the injection regularity of each nozzle of the injector was very good. |
