Optimisation of the Topping-Up Process of Lubricating Oil in Medium-Speed Marine Engines

This article presents the influence of various ship’s operational conditions occurring during manoeuvres related to entering and leaving the ports and mooring operations. Frequent starts and stops of the ship’s propulsion unit are then required, which affect the variability of the energetic loads of the ship’s power plant, causing accelerated, non-design wear of the ship’s main propulsion engine. The effects of cold start-ups of the main ship engine are the subject of this study. Conditions of the engine inlet valve damage process are discussed. The physics of the degradation process leading to air inlet valve damage was considered. Laboratory tests of structure continuity and their results are discussed, and the valve material defects were excluded as the cause of the damage. The causes of repeated damage to the inlet air valves were identified. The effectiveness of the performed corrective measures was confirmed by a documented control test of the engine start-up. The article is a utilitarian premise for the requirements of the Classification Society.

Section: Introductionmentioning

confidence: 99%

Studies on the Effects of Cold Starts of the Ship Main Engine

Adamkiewicz

Fydrych²,

Drzewieniecki

2022

“…Despite this, shipowners continue to use mineral oil for fear of, among other things, EALs becoming old and possibly losing the required bearing capacity of stern bearings and intensifying bearing pan wear as a consequence. This phenomenon is clearly visible in the engine lubrication oils [8] The presented condition constitutes the primary motivation for the undertaken research, which seeks to compare the operation of a plain bearing, with a structure similar to that of a stern bearing of a ship, lubricated with either mineral oil or an EAL. Although the issue of EAL aging was presented in a multi-faceted manner in [9], an analysis of the literature on the subject confirms that there are relatively few studies that address this issue.…”

Section: Introductionmentioning

confidence: 99%

Assessing the Potential Replacement of Mineral Oil with Environmentally Acceptable Lubricants in a Stern Tube Bearing: An Experimental Analysis of Bearing Performance

Kowalski

Leśniewski

Piątek

et al. 2021

This study compares the performance of a plain bearing, with a similar structure to a tail shaft stern bearing, lubricated with either mineral oil or an environmentally acceptable lubricant (EAL). The main characteristic of the bearing is its length/diameter ratio of <1. Measurements are carried out with the bearing operating under loads from 0.5 to 1 MPa and seven speeds ranging from 1 to 11 rev/s. The bearing lubricated with either mineral oil with a viscosity grade of 100 or an environmentally acceptable lubricant (EAL) with a viscosity grade of 100 or 150 is investigated according to the ISO standard. Bearing wear is simulated by increasing the clearance circle by 0.1 mm. According to the results obtained, the use of an EAL in place of mineral oil does not cause significant changes in the bearing performance, regardless of the value of the clearance radius. The pressure distribution in the oil film, bearing load carrying capacity, eccentricity and friction coefficient have similar values for the entire load and speed ranges considered, and the discrepancies in the results are within the range of the measurement errors. Only an increase in EAL viscosity causes significant changes in bearing performance and these changes comply with the general theory of lubrication.

Concept of Vibroacoustic Diagnostics of the Fuel Injection and Electronic Cylinder Lubrication Systems of Marine Diesel Engines

Varbanets

Shumylo

Марченко

et al. 2022

Although direct measurements of the fuel injection pressure and the travel of the injector needle in conjunction with measurements of the valve train mechanism timing can provide complete diagnostic information about the technical conditions of the fuel injection and valve train systems, this requires the installation of sensors and other equipment directly into the systems, which is possible within research laboratories but is generally forbidden during operation of the ship. Malfunctions in the fuel injection and valve train systems can also be identified from the indicator diagrams of an engine operating cycle, expressed as P(V) and P(deg) diagrams. The basic parameters of the engine operating cycle, such as the maximum combustion pressure Pmax, compression pressure Pcompr, and indicated mean effective pressure IMEP, can also be used to indicate deviations from proper engine operation. Using a combination of a vibration sensor with an in-cylinder gas pressure sensor widens the capabilities of diagnostics for marine diesel engines under operational conditions. A vibration sensor with a magnetic base can help in determining the timings of the lifting and landing of the injector needle, fuel delivery by the fuel injection pump, opening and closing of the circulation of heated heavy fuel oil, and opening and closing of the gas distribution valves. This also offers a promising solution for diagnostics of the cylinder lubrication oil injectors. The proposed approach allows valuable information to be received during engine operation in accordance with the principle of non-destructive control, and can help in early detection of possible engine malfunctions.