Description
ABSTRACT
Engine health diagnosis through oil analysis is widely used across various industries as a method for accessing engine health. This study is aimed at investigating the health of Perkins engine power plant through oil analysis program, emphasizing its effectiveness as a predictive maintenance tool. Oil analysis using the OSA4 Analyzer was conducted on samples taken from Parkins’s engine at various operational stages. The analyzer is a spectrometer that integrates an optical emission spectrometer (OES) and an infrared module. The OES excites a portion of the used oil samples and measure the concentration of sub-microscopic metals in the solution, while the infrared module scans a portion of the used oil sample to measure the physical properties of the oil and look for contaminants. The results obtained demonstrated early signs of the engine wear, contamination and oil deterioration. Wear metals such as iron and iron and copper, which are indicators of specific component wear, were consistently monitored. The findings of this study can be applied in power plants and other industries using Parkins’s engines or similar machinery to enhance maintenance strategies, improve engine reliability, and minimize operational downtimes through a proactive approach to engine health monitoring.
CHAPTER ONE
INTRODUCTION
- Background to the Study
The internal combustion engine used in many industries is an assembly that includes both fixed and moving parts. In the operation of the engine, different types of friction may appear (dry, semi-dry, liquid and semi-liquid). To minimize the effects of friction (overheating and wear of parts), various lubricating oils are used that provide a protective film that reduces contact between the moving components of the engine (Rațiu et al., 2020). Besides the lubrication role, the engine oil also performs a series of other functions, such as cooling certain parts of the engine, sealing possible clearances that could appear (especially in pistons and cylinders), offering protection against corrosion and cleaning the residue that otherwise would clog the engine. During these operations, the lubricant absorbs various contaminants and is subjected to physico-chemical and thermal processes that degrade its structure, ultimately leading to oil breakdown and the formation of used engine oil, which if not changed in time is harmful to the components and impedes the proper operation of the engine. Contaminants that lead to engine oil degradation are of a wide variety. From particles of sand and dust absorbed through the intake air to water, fuel or drops of coolant, including metal fragments and oxidation products, all these substances destroy the structure of the lubricant, affecting the additives that improved its properties and modifying their chemical composition. Thus, the oil not only can no longer fulfill its function of protection of engine components, but also acts as a factor of enhancing engine wear and endangers the entire operation of the engine (Rațiu et al., 2020).
In industry, it is important to ensure that all equipment are properly maintained. Whether a fleet of trucks or heavy equipment on a job site, it’s vital to ensure engines are functioning efficiently at all times. When one knows that engines are free of mechanical issues and contaminants, it will give the confident that equipment will continue delivering reliable performance with every job (Wang et al., 2015).
One of the most effective ways to confirm your engines are operating at their best is to schedule oil analyses for your equipment. Testing oil periodically helps identify potential problems at the source and prevent costly issues from occurring before they impact machine functionality and productivity. By detecting an issue early, you can also plan for maintenance instead of dealing with unexpected downtime. Additionally, oil sampling maximizes savings by allowing you to increase and optimize oil change intervals (Wang et al., 2015).
Oil analysis is a common preventive maintenance process used to procure valuable information regarding your equipment’s operating conditions by analyzing its oil health. These laboratory analyses typically examine three aspects of an engine’s lubricant, including:
- Oil properties, such as the base oil and its additives.
- The presence of common contaminants.
- Signs of machine wear and debris.
Oil analyses are used to identify abnormalities and other signs of bad engine health before they negatively impact a machine or even cause equipment failure. When you test your oil through oil analysis, you can take action and correct potential mechanical issues before they require costly repairs.
Oil analysis is essential in determining an engine’s health. When you book scheduled oil sampling services, you can ensure your engine is well-maintained and functioning properly at all times through comprehensive analyses performed by knowledgeable and experienced professionals (Macian et al., 2015).
Over time, your engine’s mechanical parts and components release a metal particulate that seeps into your oil. When you take your equipment to a trusted service provider, a team of skilled technicians monitor these particle levels to determine engine health. Likewise, these particulates notify a technician of abnormalities you might not otherwise notice. This all contributes to a longer machine expectancy and life. Technicians also assesses relevant oil and fluid trends, such as wear metals like iron, copper and aluminum, and harmful contaminants like coolant entry, air, soot, water, fuel and debris.
- Statement of the Problem
Engine oil contamination can reduce the oil’s lubrication and protection properties over time. As such, it is highly detrimental to machinery, causing equipment breakdown and even critical machine failures. Consequently, that results in unexpected downtime, costly machinery repair costs, and company reputation loss due to missed deadlines (Wang et al., 2015).
There are four primary methods of monitoring equipment’s condition: vibration, thermography, acoustic emission, and oil analysis. The first two present several limitations for application in reciprocating internal combustion engines; the last one is the most commonly applied technique in these cases. Thus, oil analysis is one of the most important techniques applied for condition monitoring and must be understood as a diagnostic maintenance tool. Used oil testing provides interesting information about the condition of the oil, the equipment in which it is being used, and oil suitability for further use. Used oil analysis is comparable to a medical analysis with a blood test (Wang et al., 2015). Like blood, lubricating oil contains a good deal of information about the lubricated system in which it circulates.
- Aim and Objectives of the Study
This study is aimed at investigating the health of Perkins engine power plant through oil analysis program, emphasizing its effectiveness as a predictive maintenance tool.
The objectives of the Study:
- To obtain information about the optimum functionality of an engine.
- To assess the condition of the oil – to provide recommendations on its suitability for further use and optimisation of the oil change intervals.
- To assess the condition of the engine – to enable the detection and thus prevention of issues which left unattended may impact the reliable operation of the engine.
- Significance of the Study
This study will serve as a means of providing information about the condition of the oil, its suitability for further use and to a certain extent information about the condition of the machinery lubricated by the oil.
The analysis of engine oil is a very easy way to obtain information about the optimum functionality of an engine. It is mainly used by the main oil manufacturer industries but its application field spreads to the automotive and aircraft industries, railway servicing and machine industry (Sillion et al., 2023).
The study will serve as a means of becoming familiar with two principal engine diagnoses. One is the oil quality by determination of the physicochemical properties. The other is an estimation of the engine’s health by measurement of metal contamination in function of time.
The study will as served as a tool used in identifying abnormalities and other signs of bad engine health before they negatively impact a machine or even cause equipment failure. Analyzing these components will help you gain insights into your engine’s mechanical condition and determine the proper course of action or most effective maintenance schedule (Wolska, 2022).
The study of evaluating engine health through oil analysis will serve as a means of:
- Identifying potential problems before they occur.
- Minimizing downtime.
- Preventing costly repairs.
- Maximizing equipment life.
- Increasing resale value.
- Saving money.
- Scope of the Study/Delimitation
The scope of this work covers investigating the health of Perkins engine power plant through oil analysis program, emphasizing its effectiveness as a predictive maintenance tool. Oil analysis is a quick test that can detect a potential failure of an engine and reduce its maintenance costs. Therefore, many industries can benefit from it, both directly and indirectly. In order to obtain an accurate diagnosis, it is important to establish the engine profile with a large number of tests. The Oil analysis was done using the OSA4 Analyzer was conducted on samples taken from Parkins’s engine at various operational stages. The analyzer is a spectrometer that integrates an optical emission spectrometer (OES) and an infrared module. The OES excites a portion of the used oil samples and measure the concentration of sub-microscopic metals in the solution, while the infrared module scans a portion of the used oil sample to measure the physical properties of the oil and look for contaminants.
CHAPTER THREE
MATERIALS AND METHODS
- Research Design / study area
Oil analysis in an engine enables the operator or user to see whether the engine is functioning normally or whether there is a possibility of a future breakdown, which the test may prevent from happening without having to dismantle the engine beforehand. Perkins diesel engine power plant located at the engineering department of our institution is used in this study. This Perkins diesel engine is suitable for large facilities that require constant operation. Perkins diesel engine have a high load capacity, are economically fuel efficient, and meet international quality and safety standards.
- Procedure for used oil analysis
This deals with oil analysis (routine and non-routine), key actions required for a correct analysis, oil sampling procedure, sample turnaround time, oil sampling intervals, and interpretation of oil diagnosis & test results.
- Routine Analyses
The physical & chemical characteristics of an in-service oil are obviously linked back to the specific type of oil, its age and the conditions under which it operates. For engine oils, the tests carried out under “Routine Analyses” will typically include:
1) Viscosity
2) Water content
3) Base Number (BN) or Alkalinity reserve
4) Insolubles
5) Flash Point
6) Elements (measuring the concentration of additives and levels of wear metals, etc.)
All these tests are out in highly automated specialised laboratories. Only a small volume of oil is needed- typically less than 250 ml for a full Routine Analysis, and fully automated equipment can be used. This makes Routine Analysis quick, easy & economical to run. Normally the test method used will be according to conventional ISO or ASTM standards but where in-house specialised test methods are used these can have the advantage that the tests are specifically designed for their relevance to ‘used oil’ based on many years field experience. In cases of a dispute the ISO or ASTM methods are used as the referee method.
- Non Routine Analyses
Sometimes more sophisticated testing is needed to investigate an ongoing problem or to obtain a better diagnosis of the condition of the engine or its components. These analyses are known as “Non Routine” analyses. Such tests can be carried out as part of an investigation or indeed be done as part of an oil based condition monitoring programme. Extended analysis suites can include tests carried out on engine deposits, debris & fuel samples as well as the oil samples themselves. Non routine analyses typically require larger sample volumes (1 litre or so), and the analyses performed are chosen on a case by case basis with guidance from the oil supplier and / or engine manufacturer. Use of a different laboratory may also be required. It is necessary to provide specific and detailed information on the history of the engine & practical working details in order to determine which analysis is most useful to provide the most relevant diagnosis. As such Non Routine analyses are more time consuming and specialised, they are also more costly so it is important to provide as much background information on the nature of the problem at the point of submitting the sample.
In order to enable a full and proper routine or non-routine analysis it is essential that:
- The oil sample bottles are clean
- The oil sample taken is representative of the oil in service,
- All supporting details (e.g. sampling point, date, oil name and hours of service) are attached to the sample container and so are made available to the laboratory
- The sample is quickly dispatched to the laboratory
3.3 SAMPLING PROCEDURE
How, when and where a sample is taken from within the lubrication system is very important. This is because only a very small amount of oil is taken during sampling. A 250 ml sample represents only a very small percentage of the total oil capacity which can be up to 100,000 litres. It goes without saying that it is essential to be sure that the sample taken is truly representative of the full oil volume and take the necessary precautions when sampling oils which may be hot and contained within pressurised systems, the use of gloves and face protection is advisory. Some general, but key points regarding the acquisition of representative oil samples include:
- Sample when the machine is running at normal operating temperature, never when the equipment is stationary or cold, or after any significant addition of fresh oil.
- Sample from the main supply line of the engine, if necessary arrange to fit dedicated sampling valves that can be accessed easily and safely.
- Always sample from the same sampling point for any particular piece of equipment.
- Sample after flushing a small quantity of oil (0.5 – 1.0l) through the sampling point – and without operating the sampling valve between flushing and sampling.
- Whenever possible fill the sample directly into the sampling bottle to avoid any unnecessary contamination.
- Use only dedicated clean and dry sampling equipment intended for the sampling of used oils.
To avoid leakage fill the sample bottle to 90% capacity and ensure it is properly sealed before despatch to the laboratory.
3.4 Data Analysis
The main test is the analysis of different metallic elements that the oil contains. Indeed, the measurement of the amounts of Fe, Cr, Al, Cu, and other metals indicate the level of wear of the engine and show which the most damaged parts are. Also, by knowing the amount of K, Na, and Si, it is possible to establish whether there is any contamination by the cooling fluid.
A second test is the determination of other physicochemical parameters, such as viscosity. This test reveals a lot of other information [3] such as oil oxidation, oil dilution by fuel or water, dirty engine and so on.
3.5 ANALYSIS OF THE SAMPLE USED
To guarantee that sample will be analysed without delay, it is vital that the label attached to the sample bottle is accurate and complete. Key information includes the name of the power plant, the specific name of the engine, type of lubricant, type of engine, date of sampling and the number of hours of service. Omission or mistakes made in labelling may delay the analysis of the sample and make a correct assessment and recommendation impossible.
Analysis test kits are routinely delivered to engine and contain all the equipment & bottles necessary for taking the samples. Additionally, many kits now contain pre-labelled sample bottles and pre-paid express mail postage bags. Samples can be packaged and couriered to the nominated laboratory for testing, but care must be taken to ensure that they are labelled appropriately. Also it should be clearly stated that the package contains used oil samples for testing to destruction with a flash point greater that 60ºC, otherwise it is possible that the samples could be held in transit due to transport safety concerns. Most laboratories can now operate on a 24hr testing turnaround time from the time of sample receipt if this is required.
Pre-labelling sample bottles considerably eases this process and reduces the number of errors that can be made. However, care must still be taken to ensure that the correct pre-labelled empty bottle is used and so therefore contains the oil from the correct sampling point. It should be stressed that the interpretation of the used oil analysis results requires a precise knowledge of the equipment, its operating conditions and a range of other complimentary information in order to offer a diagnosis of machinery condition. This can include historical data from any known operating incidents that may have affected the equipment in service, plus environmental information and performance data. The value of having good additional information from the engineering staff is essential to making an appropriate diagnosis. It is also important to realise that a full and proper diagnosis cannot be achieved from the results of just one analysis.
3.6 Interpretation of the oil analyses
Correct interpretation of the oil analyses results requires monitoring the individual test parameters as a function of time or operating hours. This allows graphs to be plotted which can be extrapolated to indicate the normal operating trends of a piece of equipment and therefore what future results would be called “normal”. Any significant deviation from these trends can be highlighted by the analyst so that on-site investigations (by the engine staff) can be carried out to find the cause. Any analysis made outside this context is very often difficult to interpret. When sampling for oil based Condition Monitoring (CM) the sampling frequency for systems will vary according to the result of the risk assessment that is made when the maintenance review is carried out; however in the main it will most likely be prudent to take samples on a monthly basis until sufficient trends have been established to allow optimisation and thus adjusting the sampling frequency thereafter as appropriate.
Note: Care must be taken however, to ensure that where a condition monitoring tool such as oil analysis is being used as a protective device, i.e. to highlight the development of a known failure condition, the sampling frequency must be shorter than the “mean time to failure”.
