Fault Diagnosis Of Marine Common Rail High Pressure Fuel Pump Based On Pressure Signal Of Accumulator Chamber

As the hydraulic power source of high pressure common rail system,High pressure fuel pump is of vital importance to the reliability of common rail system.High pressure fuel pump is with high fault rate and great fault influence,once the high pressure fuel pump fails,the rail pressure is unable to be established normally,the high efficiency and stable operation of diesel engine is unable to be guaranteed.The existing diesel engine is difficult to monitor the high pressure fuel pump effectively,the fault diagnosis of high pressure fuel pump relies on the experienced knowledge of engineers,which has high requirements on engineers,consumes time and energy,and is not able to evaluate the state of high pressure fuel pump in an ideal manner.As a consequence,it is difficult to effectively guide maintenance.So it is of great engineering application value to carry out research on fault diagnosis technology of high pressure fuel pump.Combined with the engineering application background,this paper studies the fault diagnosis technology of marine common rail high pressure fuel pump based on the pressure signal of the accumulator chamber.The research objective of this paper is to isolate the failure mode to the fault one of the two pumps according to the characteristics of marine common rail system and actual engineering requirements.Based on the failure mode effectiveness analysis(FMEA)method,the potential failure mode of the marine common rail high pressure fuel pump is systematically analyzed.The simulation model of high pressure fuel pump is established and calibrated,and the pressure signal of the accumulator chamber in fault state is simulated by injecting faults.Based on the dimensionless waveform parameter analysis method in time domain and FFT method in frequency domain,the pressure signal of the accumulator chamber of the high pressure fuel pump in fault state is analyzed.As a result,the faults of high pressure fuel pump are classified into two types: metering valve stuck fault and fuel pumping fault.The fault characteristics of the two types are analyzed in detail and fault diagnosis strategies are developed respectively.A metering valve stuck fault diagnosis method based on the pressure signal of the accumulator chamber and the control current signal of the high pressure fuel pump is proposed for the metering valve stuck fault,which proves to be effective by simulation and can effectively diagnose the metering valve stuck fault.Fault diagnosis method based on optimization factor,waveform factor and energy entropy are proposed for the fuel pumping fault.The proposed methods prove to be effective by simulation and test and can effectively diagnose the fuel pumping fault.