Lubricating Oil Research Articles

Building The Health Monitoring and Fault Diagnosis Models For Stamping Press

A stamping press is widely used for the metal forming process. To achieve continuous automation and high precision forming, monitoring the press's health and diagnosing faults during stamping is necessary. The three primary types of faults that may occur in the stamping press are lack of lubrication oil, quality variation of lubrication oil, and clearance variation, which can lead to a decline in workpiece quality and reduced lifespan of the dies and presses. This study adopted the Prognostics and Health Management (PHM) technique to implement a predictive maintenance system for the stamping press. To extract relevant data, the National Instrument (NI) DAQ was used to acquire the three-phase currents and X, Y, and Z vibration signals. Six signals provided a total of seventy-two features, and the top three key features were selected for building a health assessment model using the Logistic regression and PCA algorithms. An early warning is triggered when the health indicator drops below the threshold, alerting the operators. Additionally, fault diagnosis was achieved using classification algorithms such as Support Vector Machine (SVM), K Nearest Neighbors (K-NN), and eXtreme Gradient Boosting (XGBoost). The fault diagnosis model achieved high accuracies of up to 99%.

Experimental Detection of Lubrication Characteristics in a Solid–Liquid Two-Phase Flow Supported Bearing-Rotor System Using Vibration Monitoring Techniques

This work aims to investigate the friction and vibration behaviors of a liquid–solid two-phase flow supported bearing-rotor system for the early monitoring and assessing of oil contamination resulting from externally ingested particles. Based on a Jeffcott rotor test rig, the lubricating oil in journal bearing was mixed with micron-scale silica particles of different sizes and concentrations. The vibration monitoring techniques utilizing eddy current, photoelectric, and piezoelectric sensors were conducted to detect the rotor displacement amplitude and bearing acceleration online. According to the quantitative evaluation, the vibration frequency spectrum, shaft trajectory, and the bearing surface characteristics were analyzed and classified at different conditions of particle parameters. Furthermore, the lubricating mechanism at bearing interface which possesses a strong interactive coupling effect with rotor vibration was deduced and illustrated. The results showed that although the sizes of ingested micron particles were less than the minimum oil-film thickness, they usually exhibited detrimental effects on the flow stability and fluid support. As the particle size or concentration increased, the interaction between particles and bearing surfaces led to the burrs in time-domain waveform, reverse displacements in rotor orbit, higher frequency harmonics in vibration spectrum, and the scratches on the bearing surface. The occurrence of continuous three-body friction could induce misalignment, blockage, oil starvation, and rub-impact fault. Furthermore, the detectability of particle contamination and damage microstructure of bearing surface was described for reference.

Determining the effect of anti-friction additive on the power of mechanical losses in a rotary piston engine

Experimental studies of the effect of adding the antifriction additive Multi-Tech-Conditioner to lubricating oil on the power of mechanical losses of a rotary piston engine were carried out, the purpose of which was to reduce the cost of potential energy of a compressed working fluid to overcome friction forces. The experimental data obtained make it possible to estimate the value of irretrievable losses of the available power of a rotary piston engine at the stage of its design and operation. Experimentally, a positive effect of the addition of the Multi-Tech-Conditioner antifriction additive to lubricating oil on the change in the power of mechanical losses of the engine was established, which was reflected in a decrease in total losses over the entire operational range of change in the rotor speed by 11.8 %. As a result of the research, it was determined that the losses for pumping strokes (gas exchange) in a rotary piston engine amount to 31.6 % of the total power of mechanical losses. An assessment was made of change in the mechanical efficiency of a rotary piston engine with a hinged-cam mechanism for converting motion under the conditions of applying an antifriction additive to lubricating oil. It has been established that the addition of the Multi-Tech-Conditioner additive to the lubricating oil in a ratio of 1:14 makes it possible to increase the mechanical efficiency of a rotary piston engine depending on the speed by 3.8–5.5 % for all operating pressures in the inlet receiver. Based on the generalization and systematization of the obtained experimental data on the use of the Multi-Tech-Conditioner additive, the most rational operating ranges of a new design rotary piston engine were identified. The maximum mechanical efficiency of a rotary piston engine is achieved in the load range of 65...75 % of the rated power, and the speed range is 63...70 %

A Technical Review on Performance and Emission Characteristics of Diesel Engine Fueled with Straight Vegetable Oil

As energy reserves are depleting day by day and the environment is polluted, finding an alternative to fossil fuel has become an essential task for the world community. Green fuel (straight vegetable oil) has been found to be a capable alternative to fossil fuel in many applications. Using unprocessed unblended straight vegetable oils (UUSVOs) as a fuel for diesel engine is advantageous in minimizing the processing time, energy, and cost associated with biodiesel production. However, the higher viscosity of vegetable oils limits their long-run use in diesel engine. A planned methodology is, however, required to resolve the issues of poor engine performance and affected emission parameters. This article aimed to present a critical review of the impact of UUSVOs on the performance and emission level of diesel engine during short and long-run engine operations. The crucial aim of this article is to find an eco-friendly alternative to fossil fuel that may serve the world community. The recent literature review shows that straight vegetable oils (SVOs) may become an excellent alternative to diesel engines during short-run operations. However, long-run operation with SVOs as a fuel creates many problems related to damage and maintenance of the engine parts, deteriorated engine performance, significant variation in emission, chocking of injector and fuel line, degraded lubricating oil quality, etc. Engine performance can be improved through the optimization of operation parameters and fuel preheating prior to the injector.

Dispersion of reduced nanodiamond and its application in lubrication

Nanodiamonds (ND) possess remarkable properties derived from both bulk diamonds and nanoparticles. However, their full potential has been impeded by spontaneous particle agglomeration caused by high surface energy. To address this, we have developed a facile, cost-effective, and contaminant-free method to homogenize the ND surface by incorporating sodium borohydride (NaBH4) reduction in a mechanochemical process. Throughout this study, we extensively investigated various influencing factors, such as grinding time, reducing agent ratio, and surface charge, to successfully modify the ND surface. The results demonstrated that the introduction of hydroxyl functional groups significantly improved dispersibility and enabled the re-dispersion of modified ND into the water and other common solvents, achieving particle sizes below 200 nm. Notably, our reduced ND exhibited potential as an additive in lubricating oil, contributing to energy saving and emission reduction. For instance, when 0.02% reduced ND was supplemented into PAO6 lubricant oil, it cannot only reduce the oil consumption by 7.72% but also significantly lower CO, HC, and NOX emissions by 20.2% and 12.7%, respectively. This suggests that the proposed strategy for ND surface chemical modification can enhance colloidal stability and find practical applications in the lubricating oil industry.

An alternate acid cleaning process for the regeneration of waste engine oil and a proposed procedure for the disposal of produced sludge

In Pakistan most of the used motor oil cleaning businesses is carried out in processing containers. They do the simple heating and after that a concentrated sulphuric acid is slowly mixed at a room temperature for the removal of the oxidized carbonized substances and other dirt stuff. This study is an attempt to propose an alternate relatively cleaner methodology for the cleaning of used lubricating oil. Briefly, the spent oil was heated till the knocking sound disappeared or in other words the water is fist removed. After that at a room temperature the dehydrated oil was treated with the glacial acetic acid (instead of sulphuric acid) for an hour. A settling time of 24 hours is provided after which reddish brownish (top) and black (bottom) layers were formed. The collected upper layer was then treated with fuller earth (Multani meti) under continuous stirring. Finally, after cooling to a room temperature the oil was filtered to a reasonably regenerated lubricating oil. This cleaning process recovers about 53% v/v of the lubricating oil. The remaining sludge containing the acetic acid is a biodegradable mixture. Moreover, the sludge of the acid treatment can be mixed with cement to prepare concrete blocks.

Synthesis of the Antioxidant Compounds from the Eugenol to the Lubricating Oils

In this study new antioxidant compounds were prepared by (thiol-ene) click chemistry, where these compounds were prepared using (1:1) mole ratio of (thiol : eugenol) in the presence of benzoyl peroxide as initiator and the reaction is carried out at (100 0C) for (9) hrs. 
 (FT-IR), (1HNMR), and mass spectroscopy were used to characterize the synthesized compounds. They were evaluated as antioxidants by adding compounds to base oil and lubricant oil, where they showed high antioxidant activity against lubricant oil oxidation processes.

Development of boiling flow pattern map and heat transfer correlation of R32-oil mixture inside a horizontal micro-fin tube

R32 has been widely applied in room air-conditioners (ACs) because of its low GWP, and its heat transfer characteristics in refrigeration cycles may be affected by the lubricating oil mixed in R32. To quantitatively evaluate the effect of oil on the flow boiling heat transfer characteristics of R32, the flow pattern map and heat transfer correlation of R32-oil mixture are needed. In this study, an experimental rig for R32-oil mixture is established, in which the boiling flow patterns are observed and the heat transfer coefficients are measured. The experimental conditions cover the evaporation temperature ranging from -5 to 15 °C, mass flux ranging from 100 to 400 kg m−2s−1, vapor quality ranging from 0.1 to 0.9 and oil concentration ranging from 0% to 5%. A total of 80 flow patterns and 336 heat transfer coefficients have been obtained under the above experimental conditions. The results show that the flow patterns of R32-oil mixture contain stratified wavy flow, intermittent flow, annular flow and dryout flow, and the presence of the oil could promote the transformation from stratified wavy flow to annular flow; the heat transfer would be enhanced by the oil under lower vapor qualities and be deteriorated under higher vapor qualities. The boiling flow pattern map is developed based on observation results, which could well predict the flow patterns under the experimental conditions. The heat transfer correlation is developed based on the flow patterns and could predict 82% of the experimental results within a deviation of ± 20%.

Adsorption limitation investigation on olefins for Cu-BTC

To utilize Cu-benzene-1,3,5-tricarboxylate (Cu-BTC) adsorbed lubricant oils in the self-lubricating field, the adsorption properties of Cu-BTC on different 1-olefins must be clarified. In this work, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene were studied by the Monte Carlo method and experimentally. The adsorption limit of Cu-BTC for n-olefins was determined as 1-undecene by the adsorption isotherms. This suggested a limit for even straight-chain molecules to the adsorption of Cu-BTC. The maximum ratio of the olefin length of the largest pore diameter (L/D) of Cu-BTC was approximately 1.57. Furthermore, theoretical calculations (radial distribution function (RDF)) and experiments (infrared (IR) spectra) confirmed the interaction of n-olefin adsorbates and the Cu-BTC framework occurred between the -CH= of olefins and the Cu and O atoms of the Cu-BTC framework. This work adds to the understanding and investigation of the adsorption of liquid lubricants using Cu-BTC as a metal-organic framework (MOF).

Biodegradation of Waste Lubricant Oil by a Novel Isolated Biosurfactant Producer- Achromobacter xylosoxidans PSA5

Waste lubricant oil (WLO) is a critical environmental issue because of its recycle and disposal challenges. A potent biosurfactant-producing bacterial strain was isolated by the enrichment culture technique using WLO as the sole carbon source from the oil-contaminated soils. The strain was identified as Achromobacter xylosoxidans (NCBI GenBank accession number: MW673656) based on the morphological, biochemical, and 16S rRNA gene sequencing. The preliminary characterization of the produced biosurfactant by biochemical methods revealed its glycolipid nature. The strain possessed extensive biodegradative potential and degraded various components present in WLO. The gas chromatography-mass spectrometry (GC-MS) analysis showed that the strain could degrade hydrocarbons (C7-C22) and diethyl phthalate, a priority pollutant, with a relative degradation of 43.87% within 7 days of incubation. The biodegradation of WLO by the strain confers its use in the bioremediation of oil-polluted environments, and the simultaneous biosurfactant production is undoubtedly a step toward greener technology.

Thermodynamic analysis of integrated ammonia fuel cells system for maritime application

This paper presents a novel multigeneration system that utilizes ammonia as the primary fuel for marine vessel applications. The system integrates and thermodynamically investigates various components, including solid oxide fuel cells (SOFC), gas turbines (GT), proton exchange membrane fuel cells (PEMFC), organic Rankine cycle (ORC), steam Rankine cycle (SRC), Kalina cycle (KC), and waste heat boiler (WHB). The primary objective of the integration strategy is to recover waste heat from the SOFC and harness the power generated by the PEMFC, resulting in improved thermal efficiency, reduced vessel startup time, and enhanced environmental sustainability. Mathematical models have been developed to facilitate the examination of the system’s thermodynamic performance. Comprehensive thermodynamic modeling employing energy and exergy analysis methods is employed to evaluate the effectiveness of both the proposed system and its subsystem. Moreover, the exergy destruction of all system components and integrated subsystems is quantified to provide a comprehensive understanding of their impact. The projected system exhibits an energy efficiency of 60.69% and an exergy efficiency of 57.50%. The waste heat recovery combined systems generate 1634.46 kW, accounting for 30.07% of the total power output of the integrated SOFC system. The performance of the system was analyzed through parametric studies, where different values of current density, distribution ratio (β) (from 0.1–0.4), and δ parameter (from 0–0.5) were examined. The findings revealed that increasing the current density led to a decrease in energy and exergy efficiency, despite an overall rise in the power output of the cogeneration system. Moreover, the waste heat boiler is capable of providing 1081 kg/h of superheated steam at 162 °C and 405 kPa to fulfill the heating requirements of marine lubricating oil, devices, and accommodation for seafarers on board the ship.

Development of nano biochar as a lubricating oil additive for tribological applications

Nano-materials, given their excellent anti-friction and anti-wear characteristics, have attracted significant attention in tribological applications. However, conventional nano-materials have difficulty meeting the development requirements of the eco-friendly lubricants. In this study, nano biochar derived from sesame stalk was synthesized and used as a lubricant additive in poly-alpha olefin-6 (PAO6). The tribological properties were evaluated by four ball tribological tests with steel and ceramic balls as the friction pair. Following the friction experiment, the worn surface on the steel ball was analyzed by X-ray photoelectron spectrometry. The steel ball friction results showed that the lubricants containing 0.2 wt% nano biochar achieved a maximum wear volume reduction of 46% compared to PAO6, and the friction coefficient decreased by 34.6% for the ceramic balls. Analysis indicated that the enhanced wettability of nano biochar lubricant contributed to improving the anti-wear properties. Characterization of the worn surface revealed that the addition of nano biochar facilitated the formation of strong Fe3O4 tribofilms. This study demonstrated that nano biochar could serve as an environmentally friendly additive in the liquid lubricant industry.

Highly stable fluorine-free slippery liquid infused surfaces

A promising Slippery Liquid Infused Surface (SLIS) has been developed, that is both easy-to-produce and environmentally friendly. Using a double replication method, a 200 µm-thick texturized cross-linked PDMS film was obtained, leading to a grid of micrometric hills and deep wells. A comparison between perfluoropolyether (PFPE) lubricant and silicone oil of different viscosities highlights the advantage of silicone oil, which penetrates the cross-linked PDMS matrix even at high viscosity. Chemical modification with OTS (octadecyltrichlorosilane) and introduction of secondary structures through plasma etching, increased the surface's shear resistance. As a result, stable sliding properties were maintained after hundreds of cycles of immersion in water and, more originally still after tests under wind blowing exposure up to 78 m/s. Furthermore, addition of water sprayed during wind blowing exposure allows partial fouling release of the surface.

Emission Characterization of Petrol, Ethanol and Spent Engine Oil Blends for Two-Stroke Spark Ignition Engine

Exhaust emission has remained a big global concern in atmospheric change, and has thus, lead to stiffer polices on emission. To achieve the set emission targets different fuel mix and combustion process are continuously been investigated. This work is used to practically model the condition of a two-stroke engine that has run over time whose used lubricating oil finds its way from the sump to the combustion chamber and thus resulting to greater rate of incomplete combustion and higher emission. An exhaust analyser with a deep probe was deployed to access the out-going burnt gasses from a two-stroke spark ignition engine that is fed with multi blends of petrol, ethanol and spent engine oil. The characteristics of the emission constituents were investigated and compared to the global limits set by different organizations such as California Air Resources Board, Environmental Protection Agency in USA, International Council on Clean Transportation, Road Transport Bureau- in Japan, and European Emission Standard Agency, among others. The result shows an increase in , and emissions with samples that contain spent oil as against those with new engine oil which is also more effective. It was also found that samples with higher quantity of ethanol show lower emission of , and gases. This is likely due to interstation of ethanol molecules with that of the spent oil, thus making it more potent for further combustion. This was also supported with the fact that emission was higher in blends with higher quantity of ethanol. Thus, the presence of ethanol in fuel blend used in two-stroke spark ignition engine may be considered to be a source of improvement in combustion and hence a means of reducing emission in two-stroke port operated spark ignition engines.

The structural, electronic, optical, mechanical and vibrational properties of Te2W with HSE03 functional

The structural, electronic, optical, mechanical and vibrational properties of hexagonal Di-Tellurium-Tungsten (Te2W) are exploited with a hybrid Heyd–Scuseria–Ernzerhof 2003 (HSE03) functional and semi-local general gradient approximation (GGA) scheme using ab initio density functional theory (DFT) calculations. The structural and electronic properties have been analyzed with the band structure and electron orbitals from the partial density of states (PDOS). Our reflectivity data from optical spectra explain its applications over mechanical engineering such as lubricant oils, further with the fact that the refractive index results obtained suggest the possibility of deploying Te2W material over optical displays. Our work finalizes by testifying the physical and mechanical stability, with our DFT-calculated elastic coefficients along with its criteria, mechanical moduli and phonon data provided. In general, our non-local hybrid functional corrects the band structure and bandgap energy [Formula: see text] extremely well, over the traditional semi-local exchange-correlation functional.

Robust SiO2/polymer hybrid microcapsule synthesized via emulsion photo-polymerization and its application in self-lubricating coatings

In this work, a novel kind of SiO2/polymer hybrid microcapsule encapsulating lubricant oil was prepared via a facile one-pot emulsion photo-polymerization method. In our strategy, an emulsion with the oil phase composed of SiO2 particles, photo-curable prepolymer, dichloromethane, photo-initiator and lubricant oil was firstly prepared. In the process of solvent evaporation, phase separation occurred between the photo-curable prepolymer and lubricant oil, and SiO2 particles migrated to the oil-water interface. After UV irradiation, the photo-curable prepolymer was photo-polymerized to form microcapsule shell, and SiO2/polymer hybrid microcapsule was yielded. The whole process could be finished within several minutes at room temperature, which was energy-saving and time-saving. The surface morphology of the microcapsule and the element distribution on the surface of the shell were investigated by SEM and EDS. The solvent resistance and mechanical property of hybrid microcapsules were tested. The morphology, the solvent resistance and the mechanical properties of SiO2/polymer hybrid microcapsule was controlled by adjusting the amount of SiO2 particles added in the oil phase. It was found that the introduction of SiO2 in the microcapsule shell could significantly improve the solvent resistance and mechanical properties of microcapsule. The synthesized hybrid microcapsule was embedded into epoxy resin for fabricating self-lubricating coatings. The friction and wear test results showed that the tribological property of the epoxy resin coating was significantly improved with the incorporation of the microcapsule. When the content of SiO2/polymer microcapsules was 10 wt%, the friction coefficient of the composite coating was 0.062, almost one-tenth of that of the pure epoxy coating (0.53).

Coking of gas turbine lubrication oils at elevated temperatures

Over the last several decades, turbine efficiency has improved significantly, resulting in higher turbine operating temperatures that negatively affect the lubricating oil circulating through the system. Exposure to high temperatures results in oil degradation and the eventual formation of solid deposits in the oil which greatly limit the oil’s ability to reduce wear and cool the turbine components. An experimental apparatus was designed and built to allow for the studying and better understanding of this phenomenon. The apparatus consists of a flow loop with a heated test section through which the oil is pumped. The oil that comes into contact with the hot surfaces degrades and forms solid deposits. As time passes, the deposit buildup decreases the heat transfer that occurs at the test section. The bulk oil temperatures into and out of the test section are used as indicators of the deposit induction time and buildup rate, and the deposits may be analyzed at the end of the experiment. Air or an inert gas may be used to pressurize the system up to 69 bar, while test section surface temperatures may be as high as 650°C. Data from one of the initial tests performed with the apparatus using a gas turbine lube oil are included in this paper. The test resulted in the clear formation of solid deposits on the heated surfaces and in the data that show the decrease in the bulk oil temperature over time due to their formation. Assembly and testing of the apparatus have been completed, and it is now fully operational and ready for future studies on lubricating oil thermal degradation and oxidation.

Effects of a hierarchical pore structure on the tribological properties of an oil-containing iron-based composite

Oil-containing materials depend on micropore structures to store lubricating oil. However, the micropore structure, an important component of such materials, is difficult to control. Herein, a porous iron-based oil-containing material was successfully prepared via powder metallurgy with TiH2 and polyamide 66 short fiber as dual pore formers. Scanning electron microscopy observations and analyses indicated that the complementary effect of dual pore formers enabled the formation of an interconnected hierarchical pore structure with two pore types, which not only provided abundant oil storage spaces but also facilitated the transfer of oil within the materials. Based on ring-on-block friction and wear tests, the iron-based oil-containing composite presented a low coefficient of friction (about 0.078) under a contact pressure of 1.2 MPa.

Experimental study on the performance of a great progress 10 kW organic Rankine cycle for low-grade heat source based on scroll-type expander

Based on the experimental experience of the previous 3 kW and original 10 kW organic Rankine cycle (ORC) systems, an improved 10 kW ORC experimental prototype using a scroll-type expander is built incorporating improvements to the lubricant oil loop and expander. The heat source temperature is 120 °C, while the heat supply is in range of 34–77 kW. The effects of heat supply, expander pressure difference, and degree of superheat on net power and net power-generating efficiency are discussed, and a comparison between the improved 10 kW ORC system and the original 10 kW ORC system is conducted. Results indicate that the net power and net power-generating efficiency exhibit a sharp increasing trend with the expander pressure difference for a certain mass flow rate, and the optimum degree of superheat for achieving the highest net power of 4.0 kW is found to be 10 °C. The improved 10 kW ORC system achieves an optimal net power-generating efficiency of 7.9%, which is 72.11% higher than the original 10 kW ORC system of 4.59%. Compared to the original 10 kW ORC system, the improved 10 kW ORC system achieves a net power increase of 188.79%–414.29% and a net power-generating efficiency improvement of 178.34%–416.89%. This study provides a guide for the design of the ORC experimental prototype, and has important academic significance and application value for enhancing the system efficiency.

MMP Net: A feedforward neural network model with sequential inputs for representing continuous multistage manufacturing processes without intermediate outputs

Machine learning models that are used for the prediction and control of production can improve quality and yield. However, developing models that are highly accurate and reflective of real-world processes is challenging. We propose a feedforward neural network model specifically designed for continuous Multistage Manufacturing Processes (MMPs) without intermediate outputs. This model, which is termed “MMP Net,” can accurately represent the control mechanism of continuous MMPs. Whereas existing studies on learning MMPs assume an intermediate output data, the MMP Net does not require such an unrealistic assumption. We use the MMP Net to develop prediction models for the lubricant base oil production process of a world-leading lubricant manufacturer. Evaluation results show that the MMP Net is superior to other deep neural network and machine learning models. Consequently, the MMP Net was actually implemented in a real factory in 2022 and is expected to save 900,000 dollars per year for each production line. We believe that our work can serve as a basis to develop customized machine learning solutions for improving continuous MMPs.