Oil Ring Research Articles

Porous supraparticle assembly through self-lubricating evaporating colloidal ouzo drops

The assembly of colloidal particles from evaporating suspension drops is seen as a versatile route for the fabrication of supraparticles for various applications. However, drop contact line pining leads to uncontrolled shapes of the emerging supraparticles, hindering this technique. Here we report how the pinning problem can be overcome by self-lubrication. The colloidal particles are dispersed in ternary drops (water, ethanol, and anise-oil). As the ethanol evaporates, oil microdroplets form (‘ouzo effect’). The oil microdroplets coalesce and form an oil ring at the contact line, levitating the evaporating colloidal drop (‘self-lubrication’). Then the water evaporates, leaving behind a porous supraparticle, which easily detaches from the surface. The dispersed oil microdroplets act as templates, leading to multi-scale, fractal-like structures inside the supraparticle. Employing this method, we could produce a large number of supraparticles with tunable shapes and high porosity on hydrophobic surfaces.

Synthesis of a Fully Biobased Polyfunctional Vinyl Oligomer and Their UV Cured Films Prepared via Thiol-ene Coupling

In this paper, a fully bio-based vinyl oligomer with high functionalities was successfully prepared by three steps: epoxidation of rapeseed oil, solvent-free and catalyst-free ring opening by 10-undecylenic acid, and esterification with 10-undecenoyl chloride. Then, the renewable polymers were prepared by photo-polymerization of these modified vegetable oils and typical thiol monomers (pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tris (3-mercaptopropionate) and 1,2-ethanedithiol). The synthesis of the vinyl oligomer was monitored by nuclear magnetic resonance and Fourier-transform infrared spectroscopy. The average number of the carbon-carbon double bonds of the resulting vinyl oligomer is high to be 7.2. The kinetic of thiol-ene photo-polymerization of vegetable oil based vinyl oligomer was studied by FTIR-ATR analyses. In addition, the thermo-physical properties and thermal stability of UV-curable films were characterized. The resulting polymers exhibit excellent water resistance and thermals stability, which is promising to find application in coatings and adhesives.

Dynamical analysis of an elastic ring squeeze film damper-rotor system

In this paper, a calculation procedure is proposed to investigate the dynamic characteristics and response of an elastic ring squeeze film damper supported rotor system (ERSFD-rotor). First, the oil film pressure and force of ERSFD are analyzed by solving the Reynolds equations. Next, deformation of elastic ring is calculated by using the finite element method (FEM) based on Kirchhoff assumption. Then the dynamical equations of rotor system are numerically simulated with cooperation of the former two steps. Using the procedure, both the response of rotor and the oil film coefficients of the ERSFD can be determined simultaneously. Calculations show that the nonlinearity of oil coefficients of ERSFD are smaller than that of classic squeeze film damper (SFD). Thus, the ERSFD behaves better than the SFD in preventing bi-stable vibration of rotor by suppressing nonlinear effects of the oil film. Influences of the ERSFD parameters, namely the oil film thickness, ring thickness and number of elastic ring bosses, on the dynamical characteristics and response of the rotor are also discussed. The study reveals that the elastic ring enable better dynamical performance of the ERSFD than the SFD in three aspects.

Influence of the Position of Oil Drain Holes of a Piston on Lubricating Oil Consumption

An increase in lubricating oil consumption in a gasoline engine causes an increase in particulate matters in exhaust gases, poisoning the catalyst after treatment devices, abnormal combustion in a turbo-charged gasoline engine, and so on. Recent trend of low friction of a piston and piston ring tends to increase in lubricating oil consumption. Therefore, reducing oil consumption is required strongly. In this study, the effect of the position of oil drain holes on oil pressure under the oil ring and lubricating oil consumption was investigated. The oil pressure under the oil ring is measured using fiber optic pressure sensors and pressure generation mechanisms were investigated. Lubricating oil consumption was also measured using sulfur tracer method and the effects of oil drain holes hence the oil pressure were evaluated. Four types of arrangement of oil drain holes were tested. The oil pressure variations under the oil ring in the circumferential direction was measured. An increase in oil pressure was found during down-stroke of the piston. The lowest oil pressure was found for the piston with four oil drain holes. Two holes nearby the front/rear end of the piston skirt showed relatively lower pressure. The measured results of oil consumption showed good agreement to measured oil pressure under the oil ring. It was found that oil pressure under the oil ring affected oil consumption, and oil drain holes set near the front/rear end of the piston skirt were effective for reducing oil consumption.

Determination of critical parameters in the EAST subcooled helium system

The cryogenic system at the Experimental Advanced Superconducting Tokamak (EAST) is designed for a capacity of 1050 W/3.5 K + 200 W/4.5 K + 13 g/s liquid helium+ 13 kW/80 K. The 3.5 K subcooled helium is obtained from an oil ring pump. The cryogenic system is now being upgraded with a centrifugal cold compressor that should reduce the helium-tank pressure and temperature. This article discusses the determination of critical parameters for the cold compressor, including the efficiency of heat exchange, the location of the thermal anchor, and the length of the tip clearance between the impeller and shroud. Developing the centrifugal cold compressor is a significant aspect of the EAST cryogenic system upgrades, and the preliminary tests reported herein demonstrate the promise of the retrofit project.

Evaporating pure, binary and ternary droplets: thermal effects and axial symmetry breaking

The Greek aperitif Ouzo is not only famous for its specific anise-flavoured taste, but also for its ability to turn from a transparent miscible liquid to a milky-white coloured emulsion when water is added. Recently, it has been shown that this so-called Ouzo effect, i.e. the spontaneous emulsification of oil microdroplets, can also be triggered by the preferential evaporation of ethanol in an evaporating sessile Ouzo drop, leading to an amazingly rich drying process with multiple phase transitions (Tan et al., Proc. Natl Acad. Sci. USA, vol. 113 (31), 2016, pp. 8642–8647). Due to the enhanced evaporation near the contact line, the nucleation of oil droplets starts at the rim which results in an oil ring encircling the drop. Furthermore, the oil droplets are advected through the Ouzo drop by a fast solutal Marangoni flow. In this article, we investigate the evaporation of mixture droplets in more detail, by successively increasing the mixture complexity from pure water over a binary water–ethanol mixture to the ternary Ouzo mixture (water, ethanol and anise oil). In particular, axisymmetric and full three-dimensional finite element method simulations have been performed on these droplets to discuss thermal effects and the complicated flow in the droplet driven by an interplay of preferential evaporation, evaporative cooling and solutal and thermal Marangoni flow. By using image analysis techniques and micro-particle-image-velocimetry measurements, we are able to compare the numerically predicted volume evolutions and velocity fields with experimental data. The Ouzo droplet is furthermore investigated by confocal microscopy. It is shown that the oil ring predominantly emerges due to coalescence.

Oil Emission Measurements with a Gasoline Engine Influence of Design Measures on the Oil Ring Groove

Oil Emission Measurements with a Gasoline Engine Influence of Design Measures on the Oil Ring Groove

Present status and one upgrading method with a cold compressor of the EAST sub-cooling helium cryogenic system

Since 2006, the superconducting toroidal field (TF) coils of the Experimental Advanced Superconducting Tokomak (EAST) have been successfully cooled by supercritical helium at a temperature of 4.5 K and a pressure of 4 bara in eleven experiments. To obtain higher operating currents and magnetic fields it is necessary to lower the operating temperature of the TF coils. The EAST sub-cooling helium cryogenic system, with a warm oil ring pump (ORP), was tested twice in cool-down experiments, which made the TF coils operate at 3.8 K. However, the long term operational stability of the sub-cooling system cannot be guaranteed because of the ORP’s poor mechanical and control performance. In this paper, the present status of the EAST sub-cooling helium cryogenic system is described, and then several cooling methods below 4.2 K and their merits are presented and analyzed. Finally, an upgrading method with a cold compressor for an EAST sub-cooling helium cryogenic system is proposed. The new process flow and thermodynamic calculation of the sub-cooling helium system, and the main parameters of the cold compressor, are also presented in detail. This work will provide a reference for the future upgrading of the sub-cooling helium system for higher operation parameters of the EAST device.

The Effect of the Position and Number of Oil Drain Hole on the Oil Pressure Generating under the Oil Ring with Relation to Oil Consumption

The Effect of the Position and Number of Oil Drain Hole on the Oil Pressure Generating under the Oil Ring with Relation to Oil Consumption

复杂断块凝析气-油层A区井型井网确定及参数优化研究

本文首先对复杂断块油气藏A区储层特性和地质概况进行分析，然后利用Petrel地质建模软件和Eclipse数值模拟技术软件对油气藏井型井网进行确定，最后对水平井井距、水平井水平段长度进行了优化。研究结果表明：凝析气藏凝析气和油环采用直井进行衰竭式开采，近东西向伴生断层以南油藏采用水平井进行衰竭式开采；平行四边形井网，井距为200 m，最佳水平段长为300 m。所得结论对该区的认识和开发具有重要的指导意义。 Firstly, we analysis the reservoir characteristics and the geological condition in complex fault block condensate oil and gas zone A. Then we use the Petrel software and Eclipse software to determine the well type and well pattern. Finally we optimize the two parameters of horizontal well’s well spacing and horizontal well’s horizontal section length. The results show that the condensate gas and oil ring of condensate gas reservoir fits using vertical well in depletion development. The oil reservoir south of the early east-west associated mining fault fits using horizontal well to develop. The shape of well pattern is a parallelogram, and the well spacing is 200 m, and the horizontal section length is 300 m. The conclusion is of great significance to the realization and development of this zone.

Evaporation-triggered microdroplet nucleation and the four life phases of an evaporating Ouzo drop

Evaporating liquid droplets are omnipresent in nature and technology, such as in inkjet printing, coating, deposition of materials, medical diagnostics, agriculture, the food industry, cosmetics, or spills of liquids. Whereas the evaporation of pure liquids, liquids with dispersed particles, or even liquid mixtures has intensively been studied over the past two decades, the evaporation of ternary mixtures of liquids with different volatilities and mutual solubilities has not yet been explored. Here we show that the evaporation of such ternary mixtures can trigger a phase transition and the nucleation of microdroplets of one of the components of the mixture. As a model system, we pick a sessile Ouzo droplet (as known from daily life-a transparent mixture of water, ethanol, and anise oil) and reveal and theoretically explain its four life phases: In phase I, the spherical cap-shaped droplet remains transparent while the more volatile ethanol is evaporating, preferentially at the rim of the drop because of the singularity there. This leads to a local ethanol concentration reduction and correspondingly to oil droplet nucleation there. This is the beginning of phase II, in which oil microdroplets quickly nucleate in the whole drop, leading to its milky color that typifies the so-called "Ouzo effect." Once all ethanol has evaporated, the drop, which now has a characteristic nonspherical cap shape, has become clear again, with a water drop sitting on an oil ring (phase III), finalizing the phase inversion. Finally, in phase IV, all water has evaporated, leaving behind a tiny spherical cap-shaped oil drop.

Fluid interface moving for the concurrent production of gas cap and oil ring of gas cap reservoirs

Abstract The pressure balance between gas cap and oil ring is likely to be broken during their concurrent production in gas cap reservoirs. In order to increase the whole development efficiency of the concurrent production of gas cap and oil ring, the Zhanzhol gas cap reservoir of Kazakhstan was taken as example to carry out the research, a three-dimensional visualization physical model was established based on the similarity criterion of oil phase, gas phase and water phase, and a reservoir engineering model of fluid interface moving rate was also set up according to the material balance principle. The calculation results of reservoir engineering model tally with the results of physical simulation experiment and reservoir dynamic test data. The moving rate template of fluid interface under three development modes, depletion development, barrier water injection development and barrier plus pattern water injection development have been also established by reservoir engineering method. The main controlling factors under different development modes have been figured out: for depletion development, the main controlling factors on the stabilization of oil-gas contact are oil recovery rate and gas recovery rate; for barrier water injection development, the main controlling factors are oil recovery rate, gas recovery rate and production-injection ratio; and for barrier plus pattern water injection development, the main controlling factors are oil recovery rate, gas recovery rate, production-injection ratio and the ratio of barrier water injection to pattern water injection.

Piston ring-cylinder liner tribology investigation in mixed lubrication regime: part I-correlation with bench experiment

Purpose – The purpose of this paper is to improve the environment and save energy, friction reduction, lower oil consumption and emissions demand that are the chief objectives of the automotive industry. The piston system is the largest frictional loss source, which accounts for about 40 per cent of the total frictional loss in engine. In this paper, the reciprocating tribometer, which is updated, was used to evaluate the friction and wear performances. Design/methodology/approach – An alternate method is introduced to investigate the effect of reciprocating speed, normal load, oil pump speed and ring sample and oil temperature on friction coefficient with the ring/liner of a typical inline diesel engine. The orthogonal experiment is designed to identify the factors that dominate wear behavior. To understand the correlations between friction coefficients and wear well, different friction coefficient results were compared and explained by oil film build-up and asperity contact theory, such as the friction coefficient over a long period and averaged the friction coefficient over one revolution. Findings – The friction coefficient changes little but fluctuates with a small amplitude in the stable stage. The sudden change of frequency, load and stroke will lead to the oil film rupture. The identification for the factors that dominates the wear loss is ranged as F (ring sample) > , E (oil sample) > , B (stroke) > , D (temperature) > , A (load) > , G (liner) > and C (frequency). Originality/value – This paper develops and verifies a methodology capable of mimicking the real engine behavior at boundary and mixed lubrication regimes which can minimize frictional losses, wear, reduce much work for the experiment and reduce the cost. The originality of the work is well qualified, as very few papers on a similar analysis have been published, such as: The friction coefficient values fluctuating in the whole stage may be caused by the vibration of the system; suddenly, boundary alternation may help the oil film to form the lubrication; and weight loss mainly comes from the contribution of the friction coefficient value fluctuation. The paper also found that the statistics can gain more information from less experiment time based on a design of experiment.

Mixed Lubrication and Friction Power Loss of Piston Ring Pack

With consideration of asperity contact, the minimum oil film thickness and friction power loss are calculated by simultaneous solution of the dynamics, blow-by and lubrication of piston ring pack. Take the piston ring pack in the first cylinder from the free end of a six-cylinder diesel engine for example, results show that the asperity contact takes place at all of the compression rings and oil ring; the minimum oil film thickness is 1.04μm at the top ring; the total friction loss power is 0.94kW, the top ring accounts for 37.2%, the second ring accounts for 33.0%, the oil ring accounts for 29.8%.

Prediction Technology for Top Gas Reservoir of Oil and Gas Reservoir of Three-Dimensional Seismic Pre-Stack Parameters: Application in Jinzhou South Oil and Gas Field in Bohai Sea

It is the key of using the oil layer efficiently to avoid the top gas reservoir of the oil and gas reservoir in the development of the offshore oilfield. The oil reservoir in the second member of the Shahejie Formation of the Jinzhou South Oilfield in the Bohai Sea is a complex oil and gas reservoir of top gas, narrow oil ring and edge water. The oil and gas reservoir is longitudinally divided into multiple sets of fluid systems, and the gas-oil interfaces of different fault blocks are not consistent with large differences. The positions of the gas-oil interfaces and oil-water interfaces need to be determined precisely in the development and design of the horizontal wells on the drilling platforms, so as to prevent the premature gas channeling and water invasion of the production wells. Thus the identification of the top gas reservoir is particularly important. In this paper, we used seismic attribute analysis, pre-stack elastic parameter coordinate rotation method fluid detection and other technologies to identify the top gas reservoir of the oil and gas reservoir in the second member of the Shahejie Formation of the Jinzhou South Oilfield in the Bohai Sea, and obtained good application effects. Key words : Oil and gas reservoir; Top gas reservoir; Three-dimensional seismic high resolution amplitude preservation processing; Seismic attributes; Pre-stack elastic parameter coordinate rotation method; Fluid detection

A Study on Measurement of Conformability of the Piston Oil Ring on the Cylinder Bore Under Engine Operating Condition by Laser Induced Fluorescence Method Using Optical Fiber

It is known that a cylinder-bore shape affects engine oil consumption. This study aimed clarifying the conformability of an oil-ring under engine operating condition. Oil film thickness at the sliding surface of oil-ring rails was measured by laser induced fluorescence (LIF) method using optical fiber embedded in the oil-ring. Findings showed that the piston tilting motion affected oil film thickness. Furthermore, thicker oil film was found at the following rail than that at former rail. It suggested that oil was supplied to the following rail from not only the former ring sliding surface but also somewhere, for example, the oil ring groove.

Using gum arabic тo form oil-water emulsions in food products

Despite the large number of studies on using gum arabic in various fields of the food industry, little attention has been paid to the study of this stabilizer in food emulsions for beverages. In this paper, the influence of the physical and chemical properties of gum arabic when using it in food products was determined. Using the dependence theory of the emulsion stability on the ratio of water gum arabic stabilizer and the oil phase, the process of obtaining pre-emulsion and the homogenization mode of the emulsion system, the formulations of food emulsions with varied amount of stabilizers and the fat phase were developed. The results of the samples of food emulsions using different amounts of gum arabic (at the constant oil phase) and the samples of emulsions with the variable oil phase and a constant amount of gum arabic were considered in detail. The analysis of the prepared emulsion indicators, such as the measured particle size, viscosity, turbidity and dependence on the ratio of water and oil phases of the system, the process parameters, was carried out. The indicators of each emulsion were measured: viscosity by the Brookfield viscometer, particle size by a microscope EASTCOLIGHT 92012-ES (100x, 250x, 550x, 750x) , turbidity by a turbidimeter 2100P. The optimal ratio between water stabilizer and oil phase of the emulsion, which is characterized by obtaining the maximum amount of emulsion particles of up to 1 micron was determined. Emulsion has a highly reliable stability if the particle size is less than 1 micron and has some turbidity, but the more particles are smaller than 1 micron, the less turbidity is. If there is insufficient amount of stabilizer, a small number of particles larger than 1 micron is formed, leading to the appearance of “oil ring” during long-term storage. The results can form the basis for the establishment of production technology for beverage emulsions as a class of food products. Creating a stable emulsion system is a relevant issue in the food industry, that is why the studies are useful and important for the development of new food products.

The Development and Technology Policy for a Gas Cap and Edge Water Reservoir with Narrow Oil Ring

Reservoir with gas cap, edge water is complex. And the oil-water and oil-gas interface will seriously influence the performance. Once out of control, gas and water invasion may occur, then oil productivity will fall sharply and oil recovery will become low. In addition, the oil penetrating into gas cap would lead to oil loss. So, the controlling methods are crucial. In this paper, we study the productive characteristics of a certain reservoir with gas cap, edge water and narrow oil ring. For the phenomenon several productive wells appeared gas breakthrough and water invasion after putting into production, this paper puts up a strategy shutting in high gas-oil ratio wells and blocking off gas breakthrough layers that proved effective. At the same time, adjusting oil and gas distribution underground by gas-water alternate also be proved practicable.

Surface and Wear Analysis of Zinc Phosphate Coated Engine Oil Ring and Cylinder Liner Tested with Commercial Lubricant

The objective of this study was to evaluate the tribological performance through investigating protective additive layer and friction coefficient and implementing the quantitative wear measurements on the rubbed surface of the sliding pairs. The specimens of oil ring were rubbed against cast iron engine cylinder liner under boundary lubrication conditions. The ring and liner surfaces were examined by optical, scanning electron microscope and atomic force microscopy. The elemental analysis of surfaces was performed by using energy dispersive X-ray spectroscopy. Surface observations showed that coating was removed from the ring surface. Higher levels of Ca, Zn, P, and S elemental ratios (0.93%, 0.45%, 1.55%, and 1.60% as atomic percent) were detected on the cylinder liner surface. Wear width, length, and depth measurements were performed by optical and atomic force microscopies on the ring and cylinder liner surface. The results showed that wear widths for oil ring were 1.59 μm and 1.65 μm; wear widths for cylinder liner were 3.20 μm and 3.18 μm; wear depths for oil ring were 100 nm; and wear depths for cylinder liner were 482 nm. Wear data were taken mostly from the additive layer points detected by SEM and X-ray measurements.

Mapping lubricating film thickness, film extent and ring twist for the compression-ring in a firing internal combustion engine

Experiments were conducted on a firing, 1.6l, Ford Duratec petrol engine fitted with a number of miniature transducers to record the capacitance between the sensor and piston rings. The apparatus can record ring data with high accuracy, good repeatability and very low noise allowing data capture from a 1.2mm width piston-ring travelling at up to 20ms−1. Novel post-processing has enabled the authors to map oil film thickness, oil-film extent and ring twist, simultaneously, across the cycle of a firing engine for a range of operating conditions. The compression ring is shown to sometimes exhibit a high frequency oscillation normal to the cylinder wall—a behaviour which has not been reported before.