scholarly journals Spectral Analysis of Torsional Vibrations Measured by Optical Sensors, as a Method for Diagnosing Injector Nozzle Coking in Marine Diesel Engines

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 775
Author(s):  
Sebastian Drewing ◽  
Kazimierz Witkowski
Keyword(s):  
Spectral Analysis ◽  
Optical Sensors ◽  
Power Plants ◽  
Marine Diesel Engine ◽  
Torsional Vibrations ◽  
Electric Generator ◽  
Injector Nozzle ◽  
Marine Diesel ◽  
Unique Method ◽  
Harmonic Components

The study aimed to verify whether it is possible to diagnose the coking of a marine diesel engine injector nozzle by performing a spectral analysis of the crankshaft’s torsional vibrations. The measurements were taken using laser heads, clocked at 16 MHz. The reasons for selecting this type of optical sensors are described as well. The tests were carried out under laboratory conditions, using a test stand with a Sulzer 3AL 25/3 engine, operating under a load created by a Domel GD8 500–50/3 electric generator. A unique method is presented in the paper, which enables the measuring and calculation of torsional vibrations of engine crankshafts. The method was developed at the Chair of Marine Power Plants at the Maritime University of Gdynia. It has been proven that the distribution of differences in the values of individual harmonic components depends on the location of a defective injector nozzle in the cylinder.

Transient and Unstable Torsional Vibrations on a 4-Stroke Marine Diesel Engine

2003 ◽  
Author(s):  
D. C. Lee ◽  
J. D. Yu
Keyword(s):  
Diesel Engine ◽  
Torsional Vibration ◽  
Marine Diesel Engine ◽  
Torsional Vibrations ◽  
Steady State Condition ◽  
Marine Propulsion ◽  
Friction Clutch ◽  
Marine Diesel ◽  
Noise Measurements ◽  
Unstable Vibration

Under steady state condition, unstable torsional vibration normally does not occur in shafting systems using 4stroke diesel engine due to hysteresis damping of shafting system and relative damping of standard fitted damper. However, the unstable torsional vibration occurs on marine propulsion shafting systems due to slippage of a multi-friction clutch installed between increasing gear box and shaft generator. To identify this unstable vibration and make proper counter measure, the simulation for transient torsional vibration using the Newmark method is introduced in this paper. The mechanism of this unstable vibration is verified by vibration and noise measurements of the shafting system.

Selection of a Waste Heat Recovery System for a Marine Diesel Engine Based on Exergy Analysis

2016 ◽  
Vol 25 ◽  
pp. 36-51
Author(s):  
Salman Abdu ◽  
Song Zhou ◽  
Malachy Orji
Keyword(s):  
Diesel Engine ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Marine Diesel Engine ◽  
Exergetic Efficiency ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System ◽  
Marine Diesel

Highly increased fuel prices and the need for greenhouse emissions reduction from diesel engines used in marine engines in compliance with International Maritime Organization (IMO) on the strict regulations and guidelines for the Energy Efficiency Design Index (EEDI) make diesel engine exhaust gas heat recovery technologies attractive. The recovery and utilization of waste heat not only conserves fuel, but also reduces the amount of waste heat and greenhouse gases dumped to the environment .The present paper deals with the use of exergy as an efficient tool to measure the quantity and quality of energy extracted from waste heat exhaust gases in a marine diesel engine. This analysis is utilized to identify the sources of losses in useful energy within the components of the system for three different configurations of waste heat recovery system considered. The second law efficiency and the exergy destroyed of the components are investigated to show the performance of the system in order to select the most efficient waste heat recovery system. The effects of ambient temperature are also investigated in order to see how the system performance changes with the change of ambient temperature. The results of the analysis show that in all of the three different cases the boiler is the main source of exergy destruction and the site of dominant irreversibility in the whole system it accounts alone for (31-52%) of losses in the system followed by steam turbine and gas turbine each accounting for 13.5-27.5% and 5.5-15% respectively. Case 1 waste heat recovery system has the highest exergetic efficiency and case 3 has the least exergetic efficiency.

Stress Distribution Analysis on Alloy Layer of High Power Marine Diesel Engine Bearing Bush

2013 ◽  
Vol 331 ◽  
pp. 148-152
Author(s):  
Xiu Xu Zhao ◽  
Zhi Xiang Hu ◽  
An Jian Huang
Keyword(s):  
Diesel Engine ◽  
High Power ◽  
Alloy Layer ◽  
Marine Diesel Engine ◽  
Oil Film ◽  
Marine Diesel ◽  
Bearing Alloy ◽  
Stress And Strain Distribution ◽  
Engine Bearing ◽  
Oil Film Pressure

According to the characteristics of large size, small clearance ratio, high oil film pressure and thin oil film thickness in the actual conditions of high power marine diesel engine bearing, this Paper analyzes oil film pressure distribution on inner surface of bearing bush based on the finite difference method, uses finite element method to establish the hierarchical model, and analyzes stress and strain distribution on bearing alloy. In addition, this Paper researches the changes of stress and strain distribution on bearing alloy layer when alloy layer thickness changes for the optimization design of high power marine diesel engine bearing bush.

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