The Use of Acoustic Emission to Diagnosis of Fuel Injection Pumps of Marine Diesel Engines

Abstract

The article draws attention to the problems of maintaining fuel injection pumps of marine diesel engines in the conditions of the use of residual fuels in which the quality is steadily deteriorating. The analysis of tribological processes occurring in hydraulic precision pairs of fuel injection pumps, such as a barrel-plunger, is presented. Problems occurring regarding the operation of injection pumps and the possibilities of their avoidance on board are discussed. The means of condition monitoring, including the application of thermography methods, are characterized. The authors have done research concerning diagnosing injection systems of high and medium power engines by using acoustic emission (AE) signals. The experiment results obtained with the use of acoustic emission and wavelet analysis confirmed the dependency of the frequency components contained in the acoustic emission signal on the condition state of the injector pumps’ tribological pair.

Method to Increase the Accuracy of Large Crankshaft Geometry Measurements Using Counterweights to Minimize Elastic Deformations

“…We propose performing crankshaft measurements with a device that is a special, versatile counterweight that supplements the basic version of the shaft with an additional mass to stabilize the reaction forces on supported main journals. The main element of the device (Figure 16) is the vee block (1), which, using an elastic band 4 (clamp), is fixed (attached) on the crank web (3) opposite the crankpin (11).…”

“…The weights (counterweight) on both sides of the guide strip (2) are chosen so that the center of gravity of the device with the weights is as recommended in points 2 to 4 of section (c). They are also located in the plane containing the axes of symmetry of the main journal (17) and the crankpin (11), which are part of the crank on which the device is installed. The measuring system supplementing the proposed device is also useful for correctly positioning the entire device on the crank, to ensure that its center of gravity is situated opposite the center of gravity of the crank-forming masses.…”

“…Additionally, their manufacture requires high geometric precision, causing crankshafts to account for an estimated 20-25% of the total engine cost [7,8]. Crankshaft manufacturing precision largely determines whether a crank-and-piston system will function correctly and, consequently, the entire working machine's reliability, safety, and operating costs [9][10][11].…”

A New Method of Identifying the Limit Condition of Injection Pump Wear in Self-Ignition Engines

“…Besides, the spectrum of generated acoustic emission pulses is strictly dependent on phenomena occurring in the macro and microstructure of the material (e.g., the fuel injection pump). The spectral analysis allows us to determine the correlation of signal functions with various frequencies [14,15]. In the case of high correlation (high correlation coefficients for sine or cosine) the occurrence of visible periodicity in the given frequency can be expected.…”

The Use of Acoustic Emission Elastic Waves for Diagnosing High Pressure Mud Pumps Used on Drilling Rigs

“…In the AE source the function of amplitude changes in the stress field has a form of a unit/single peak, the sensor is placed in the pump body (housing of the valve unit, and the elastic wave propagates in a homogeneous medium. The basic equation describing the signal propagation path can have this form [11][12][13][14][15][16][17][18][19]:…”