Oil Flow Rate Research Articles

Thermal behavior in rolling bearing applications: Comparison of steel and ceramic materials applied to tapered rollers

Due to their properties, ceramic materials can improve both reliability and efficiency of rolling bearings. Most of the studies have investigated the power losses and temperatures of ball bearings with balls made of silicon nitride (Si3N4) versus steel ones. This study thus focuses on tapered rollers. Thanks to experimental and numerical means, the thermal behavior of tapered roller bearings is investigated for both steel and silicon nitride rollers. Various operating conditions (rotational speed, oil flow rate and oil temperature) are tested to allow the comparison of the behavior of both bearing set-ups (full-steel and hybrid). A thermal model is developed according to the thermal network method and is validated thanks to experimental results. It is then used to analyze behaviors observed during experiments, related to thermal exchanges and power losses. The effect of changing the mechanical and thermal properties of the roller material is investigated.

Dynamic Criteria for Physical Modeling of Oil Displacement by Gas Injection

In this work, slim tube displacement tests for minimum miscibility pressure MMP were carried out. Based on the displacement data, the MMP was calculated by statistical regression using linear and quadratic extrapolation with threshold values of 90% and 95% oil recovery as well as the intersection of trend lines for immiscible and miscible displacement regimes. The obtained data show a significant variation in the range of MMP values depending on the calculation method. To clarify the MMP value, an analysis of displacement dynamics was carried out. The ratio of the volume flow rate of reservoir oil to the volume flow rate of the injected gas—flow rates ratio (FFR)—was used as a new parameter. The MMP value calculated from the FRR value extrapolation was determined as 37.09 MPa. According to the results obtained, the proposed methodology based on the displacement dynamics can be useful as a criterion for clarifying the MMP value in slim tube displacement experiments.

Thermal analysis of the oil cooling motor according to the churning phenomenon

In this study, the flow field and temperature distribution in a 160-kW commercial electric vehicle motor according to the churning phenomenon were investigated to analyze the effect of the churning phenomenon on the cooling performance of motor. To this end, experimental and numerical analysis were conducted to analyze the relationship between flow field and cooling performance. First, this study analyzed the effect of oil temperature on the motor cooling performance, and the results revealed that the average temperature decreased by 48.9 °C with a decrease in the oil temperature from 100 to 50 °C, but the temperature variation is increased by 10.2 %. Second, this study analyzed the effect of oil flow rate on the motor cooling performance, and the results revealed that with an increase in the oil flow rate from 5 to 10 LPM, the average temperature decreased by 8.7 °C, and the temperature variation is increased by 3.6 %. Lastly, this study analyzed the effect of motor rotation speed on the motor cooling performance, and the results revealed that the average temperature increased by 8 °C with an increase in the motor rotation speed from 8,700 to 14,000 RPM, and the temperature variation is increased by 34.4 %. These results indicate that the churning phenomenon results in a non-uniform temperature distribution and decreased the cooling efficiency by disturbing oil flow from the cooling pipe.

Thermal effect of acoustic impact on the oil reservoir

The paper considers the effect of heating an oil-saturated reservoir during the propagation of high-frequency acoustic waves in it, due to their absorption by a saturated porous medium. It is assumed that in this case, volumetric heat sources are created in the reservoir. The density of distribution of heat sources in a porous medium at various capacities and frequencies of acoustic waves is shown. The paper presents a mathematical model for calculating the temperature field in a porous saturated medium under acoustic influence with an emitter located opposite the treated reservoir. It is assumed that the radius of the acoustic radiator is equal to the radius of the well, and the length of the radiator is equal to the power of the treated reservoir. In addition, the effect of increasing the effective thermal conductivity of the formation is taken into account when calculating the distribution of the temperature field. It is believed that the well works without stopping with a certain oil flow rate, depending on the viscosity of the oil. The problem is solved by the numerical method of finite differences according to an implicit scheme in a cylindrical coordinate system. In this paper, the author presents the results of studies of thermal effects occurring in the formation, namely, an increase in the effective thermal conductivity of the formation and the occurrence of heat sources during the propagation of acoustic waves in the formation. Thus, the article presents the results of computational studies that take into account only thermal effects during the treatment of the formation by the wave (acoustic) method. The treatment of the reservoir by wave methods (acoustic, sound, water hammer, elastic, and so on) is one of the promising methods for both increasing oil recovery and intensifying oil production, therefore, the theoretical study of the processes arising from the interaction of waves with a saturated porous medium is significant.

Experimental and numerical study of stator end-winding cooling with impinging oil jet

As an efficient cooling technology, impinging jet was utilized to reduce end-winding temperature of electric machine stator in this study. Infrared imaging and numerical simulation technologies were applied to investigate heat dissipation efficiency of silicone oil jet on a real electric machine stator. Infrared camera is possible to measure end-winding temperature without influence on flow pattern and heat exchange. Numerical simulation results for end-winding temperature were validated by comparing to experimental results. Then heat transfer coefficient was calculated by inverse method, which is very difficult to be obtained by experimental method. The testing stator had three configurations, among which one was covered by aluminum foil at external surface and the other one had extra internal surface in order to lead oil flow to contact all the end-windings. Moreover, effect of dissipated heat quantity and oil flow rate were considered in present study. According to experimental and simulation results, the configuration with internal surface reveals best cooling performance by impinging oil jet. For this stator configuration, the minimum and the most cost-effective oil flow rates were found which will provide insight for impinging jet system.

Multi-Objective Optimization of Plate-Fin Heat Exchangers via Non-Dominated Sequencing Genetic Algorithm (NSGA-II)

The rules of heat transfer and fluid flow in plate-fin heat exchanger are intricate and complex, and the selection of boundary conditions is the key to giving full play to the performance of heat exchanger. In this paper, a multi-objective optimization based on computational fluid dynamics (CFD) and non-dominated sequencing genetic algorithm (NSGA-II) was carried out to obtain the optimal performance of a plate-fin heat exchanger for an extended-range hybrid vehicle engine. The angle of serrated staggered fin, oil flow rate, and water flow rate were taken as input parameters, and the heat transfer quantity, oil pressure drop, and oil outlet temperature were taken as objective functions to perform the optimization analysis of the heat exchanger. Support vector machine regression (SVR) was used to establish the objective function, and the NSGA-II algorithm was adopted to obtain the Pareto optimal solution set. The optimal solution was determined in the Pareto optimal solution set by comprehensive evaluation based on technique for order preference by similarity to an ideal solution (TOPSIS). The results showed that the best comprehensive performance of the heat exchanger was achieved at a fin angle of 63.01°, an oil flow rate of 9.7 L/min, and a water flow rate of 6.45 L/min. At this time, the heat transfer quantity was 9.79 kW, the oil pressure drop was 13.63 kPa, and the oil outlet temperature was 65.11 °C.

Slip Characteristics in Cylindrical Roller Bearings. Part I: Influence of Cage Type on Rolling Set Slip

AbstractThe slip behavior of four cage types was studied for an NU215 cylindrical roller bearing under radial forces lower than the minimum recommended by the manufacturer by performing force, speed, and oil flow ramp tests. In comparison, a specially designed full complement bearing was also tested as an alternative to the caged bearing variant. All the tested bearings started to operate slip-free at higher forces than those recommended by the bearing manufacturers. In addition to that, the increase in oil flowrate or rotational speed would increase the set slip under insufficient radial forces. Single-part outer-ring-guided brass cage experienced lower slip than its two-part equivalent while roller guidance possessed the least slip tendency among the tested cages. The polyamide cage offered the lightest weight reduction at the expense of a higher slip, whereas the full complement bearings also offer higher load-carrying capacity at the expense of higher slip.

Slip Characteristics in Cylindrical Roller Bearings—Part III: Influence of Bearing Clearance on the Roller and Set Slip

Abstract The set and roller slip of an NU215 cylindrical roller bearing with medium clearance (MC) and tight clearance (TC) classes have been tested and compared to those of extensive clearance (EC) presented in Parts I and II of this publication. A total of two cages were tested in this part presenting the brass and polyamide single-part cages. The normal TC clearance under the tight fitting of the inner and outer rings resulted in preloading of all the rollers and hence no set slip. Under low oil flowrates, the roller experienced no slip even in the load free zone. For the MC clearance, the polyamide cage showed better behavior (less roller and rolling set slip tendency) than the brass cage contrasting the results obtained earlier under the EC clearance. It is concluded that the polyamide cage deforms under the unsymmetrical loading of the EC clearance resulting in this elevated slip however, under a more even loading in the MC clearance, its lightweight was reflected in a reduced slip behavior.

Mechanical formation damage control in permeability Biot’s effective stress-sensitive oil reservoirs with source/sink term

Geomechanical effects monitoring on reservoir rock and fluid properties response during the oil production curve are essential to improve oil recovery in a petroleum field. Incorporating geomechanics to flow models become the mathematical formulation regarding well-test and reservoir engineering more realistic because geomechanical parameters, e.g., in situ and overburden stress, as well as Biot’s coefficient, play a fundamental role in pressure response. Hence, permeability stress-sensitive oil reservoirs are the scope of various research in the petroleum industry for minimizing formation damage during drilling, completion, and stimulation operations. In this context, mechanical formation damage control plays a key role in preventing early-permeability loss that may result in reservoir compaction and oil field disinvestments. This work develops a new analytical solution for the nonlinear hydraulic diffusivity equation (NHDE) with instantaneous point-source/sink effects in permeability effective stress-sensitive oil reservoirs. The proposed model considers Biot’s effective stress change in the permeability response, and a new deviation factor is derived from comparing the nonlinear effect concerning the constant permeability classical solution and a decoupled case available in the literature. The calibration methodology is performed using a numerical simulator named IMEX®, widely used in formation evaluation works, and the results presented high convergence. The findings of this study allowed us to notice the role of overburden stress, oil flow rate, deviation factor, and Biot’s coefficient in permeability change during production in the diagnostic plots. Thereby, the modeling developed in this paper becomes a useful and attractive tool for predicting and monitoring permeability loss, oil flow rate specification, and reservoir history matching.

Scalable and high-throughput production of an injectable platelet-rich plasma (PRP)/cell-laden microcarrier/hydrogel composite system for hair follicle tissue engineering

BackgroundTissue engineering of hair follicles (HFs) has enormous potential for hair loss treatment. However, certain challenges remain, including weakening of the dermal papilla cell (DPC) viability, proliferation, and HF inducibility, as well as the associated inefficient and tedious preparation process required to generate extracellular matrix (ECM)-mimicking substrates for biomolecules or cells. Herein, we utilized gelatin methacryloyl (GelMA) and chitosan hydrogels to prepare scalable, monodispersed, and diameter-controllable interpenetrating network GelMA/chitosan-microcarriers (IGMs) loaded with platelet-rich plasma (PRP) and seeded with DPCs, on a high-throughput microfluidic chip.ResultsThe ECM-mimicking hydrogels used for IGMs exhibited surface nano-topography and high porosity. Mass production of IGMs with distinct and precise diameters was achieved by adjusting the oil and aqueous phase flow rate ratio. Moreover, IGMs exhibited appropriate swelling and sustained growth factor release to facilitate a relatively long hair growth phase. DPCs seeded on PRP-loaded IGMs exhibited good viability (> 90%), adhesion, spreading, and proliferative properties (1.2-fold greater than control group). Importantly, PRP-loaded IGMs presented a higher hair inducibility of DPCs in vitro compared to the control and IGMs group (p < 0.05). Furthermore, DPC/PRP-laden IGMs were effectively mixed with epidermal cell (EPC)-laden GelMA to form a PRP-loaded DPC/EPC co-cultured hydrogel system (DECHS), which was subcutaneously injected into the hypodermis of nude mice. The PRP-loaded DECHS generated significantly more HFs (~ 35 per site) and novel vessels (~ 12 per site) than the other groups (p < 0.05 for each).ConclusionTaken together, these results illustrate that, based on high-throughput microfluidics, we obtained scalable and controllable production of ECM-mimicking IGMs and DECHS, which simulate an effective micro- and macro-environment to promote DPC bioactivity and hair regeneration, thus representing a potential new strategy for HF tissue engineering.

Improvement of Oil Recovery in Hydrocarbon Fields by Developing Polymeric Gel-Forming Composition

The paper presents the results of laboratory and field experiments on a developed polymer gel-forming composition “PSB” that enhances oil recovery. In this composition, two aqueous solutions are used: a polymeric gelling agent and an inorganic crosslinker. An alternating injection of solutions that are mixed directly in the reservoir allows a bulk gel to be formed that blocks water or gas breakthroughs. This leads to an increase in oil production, and a decrease in water cut, resulting in more efficient wells. On five wells in a hydrocarbon field that was located within the Permian-Carboniferous deposits, a series of field tests were conducted. It has been observed that wells treated with this developed polymer gel-forming composition “PSB” show a decrease in water cut, a decrease in liquid flow rates, and an increase in oil production. This technology led to an increase in oil flow rates of 5 tonnes per day per well (2 times) and a decrease in water cut of 10-40%, confirming its effectiveness. According to the values of the cumulative effect as of February 2016, this effect continues to increase oil production by 20-600 tons per well.

Parallelization of Microfluidic Droplet Junctions for Ultraviscous Fluids.

The parallelization of multiple microfluidic droplet junctions has been successfully achieved so that the production throughput of the uniform microemulsions/particles has witnessed considerable progress. However, these advancements have been observed only in the case of a low viscous fluid (viscosity of 10-2 -10-3 Pa s). This study designs and fabricates a microfluidic device, enabling a uniform micro-emulsification of an ultraviscous fluid (viscosity of 3.5 Pa s) with a throughput of ≈330 000 droplets per hour. Multiple T-junctions of a dispersed oil phase, split from a single inlet, are connected into the single post-crossflow channel of a continuous water phase. In the proposed device, the continuous water phase undergoes a series circuit, wherein the resistances are continuously accumulated. The independent corrugations of the dispersed oil phase channel, under the theoretical guidance, compromise such increased resistances; the ratio of water to oil flow rates at each junction becomes consistent across T-junctions. Owing to the design being based on a fully 2D interconnection, single-step soft lithography is sufficient for developing the full device. This easy-to-craft architecture contrasts with the previous approach, wherein complicated 3D interconnections of the multiple junctions are involved, thereby facilitating the rapid uptake of high throughput droplet microfluidics for experts and newcomers alike.

Improvement of Oil Recovery in Hydrocarbon Fields by Developing Polymeric Gel-Forming Composition

The paper presents the results of laboratory and field experiments on a developed polymer gel-forming composition “PSB” that enhances oil recovery. In this composition, two aqueous solutions are used: a polymeric gelling agent and an inorganic crosslinker. An alternating injection of solutions that are mixed directly in the reservoir allows a bulk gel to be formed that blocks water or gas breakthroughs. This leads to an increase in oil production, and a decrease in water cut, resulting in more efficient wells. On five wells in a hydrocarbon field that was located within the Permian-Carboniferous deposits, a series of field tests were conducted. It has been observed that wells treated with this developed polymer gel-forming composition “PSB” show a decrease in water cut, a decrease in liquid flow rates, and an increase in oil production. This technology led to an increase in oil flow rates of 5 tonnes per day per well (2 times) and a decrease in water cut of 10-40%, confirming its effectiveness. According to the values of the cumulative effect as of February 2016, this effect continues to increase oil production by 20-600 tons per well.

Characterization of an Apparatus to Study Solid Deposit Formation in Lubricating Oils at High Temperatures

Abstract When exposed to excessively high temperatures, the lubricating oils in turbines undergo extreme oxidation and thermal degradation processes that eventually result in the formation of solid deposits that can, in turn, cause operational problems. This work describes the testing and characterization process of a newly constructed test rig that studies the propensity of lubricants to form such deposits. In the test rig, the lubricant flows through a heated tube, thermally degrades or oxidizes, and forms solid deposits that adhere to the heated surface. An oil flow rate calibration curve as a function of pump speed was developed using two oils, Castrol GTX 20W-50 and Mobil DTE 732. The steady-state axial temperature distribution along the heated tube was measured for temperature settings of up to 475 °C and flow rates of 10.4, 12.2, and 13.9 mL/min using Mobil DTE 732. The results showed that the surface temperature is not uniform, but that it varies axially as is expected from the heat transfer in the thermal entrance region of a pipe with laminar flow. Examples of the results of tests performed with the apparatus using Mobil DTE 732 and Castrol GTX 20W-50 flowing at 10.4 mL/min with surface temperatures between 328 and 489 °C are presented. Based on these tests, it is clear that the induction time for solid-deposit formation can be unambiguously determined using the experimental apparatus. The induction times of the sample tests described were found to be 638 ± 10 min and 86 ± 10 min for Mobil DTE 732 and Castrol GTX 20W-50, respectively.

Dynamic modeling and optimization of organic Rankine cycle in the waste heat recovery of the hydraulic system

The replacement of cooling system with the organic Rankine cycle could reduce cooling energy consumption and improve the overall energy efficiency in the hydraulic system. However, dynamic characteristics have a significant impact on stable operating and performance improvement of ORC systems in applications. Therefore, based on the physical prototype, the ORC dynamic model with whole process, including start-stop process, was established and calibration. Then the dynamic characteristics of the system were studied, and the response surface method was used to optimize the operating parameters with the dynamic model. The results show that the simulation model has sufficient accuracy under both steady and transient conditions. Compared with the oil flowrate, the connected-load affects the system performance more obvious. The evaporating pressure has increased by 3.4% as the connected-load increases from 60 W to 120 W. As to the response time of evaporating pressure and evaporator outlet temperature, they are 240 s and 290 s respectively in the starting stage, and are 210 s and 190 s respectively in the stopping stage. Through the optimization, the output power of the ORC system could reach the maximum value of 832 W, when the working medium pump and expander speed are 1500 rpm and 1400 rpm, respectively. The dynamic fluctuation of oil flowrate has relatively little influence on ORC system, it can work stably in the waste heat recovery of hydraulic system, and the operation and control should consider the long response time of ORC starting and stopping process.

Roller Bearing Skidding for Aero-Engine Applications: All-Steel Versus Hybrid Bearings

Abstract Roller bearings operating under light loads may suffer from skidding. The latter is more pronounced as the speed increases and may result in extensive wear and reduced service life of the bearing. The main objective of this study is to analyze skidding occurrence in a custom-made all-steel M50 bearing and a hybrid roller bearing subjected to the same operating conditions. The test bearings have a bore diameter of 90 mm, an outer diameter of 125 mm and 26 rollers. The hybrid bearing features silicon nitride (Si3N4) rollers and steel rings (M50 outer ring and M50-NIL inner ring). The bearings feature special channels to allow for under race lubrication of the bearing components in relative motion. A suite of sensors were used and installed to detect skidding and monitor the overall performance of the test bearing such as vibrations and temperature. The effect of the radial applied load, shaft rotational speed, and oil flowrate on roller skidding has been investigated and discussed. Slip ratio for each of the bearings under various speed–load combinations was also determined and analyzed. Turbo-Oil 2380 was used to lubricate the test bearings at a constant temperature of 77 °C. Tests were conducted on a high-speed rolling bearing test rig, and data were recorded using a 24-bit data acquisition system.

Multiphase Flow Analysis Using Piezoelectric Leaf-Cell Sensor Array

The composition of the multiphase flow rates from hydrocarbon reservoirs has direct impact on the programs to optimize hydrocarbon production and for the identification of problems with production. However, the accurate measurement of the flow rates of oil, brine, and gas in three-phase regimes remains an intractable problem for current state-of-the-art sensor technologies. Here, we describe a piezoelectric acoustic leaf-cell sensor array providing an in situ real-time measurement of the distribution in three-phase flow fluid density over the wellbore cross section. The sensor array measurements are evaluated from experimental three-phase flow loop test data under a range of flow regimes comprised of 0–95% gas volume fraction and water/liquid volume ratio between 0 and 100%. The experimental data include three-phase flow transitions well into the nonlinear subsonic gas velocity region predicted by the Wood equation and show an average absolute error in three-phase fluid density prediction less than 0.05 g/cc over the entire test regimen.

Dynamic analysis as a method of wells interaction evaluation in making technological decisions

The complexity of developing oil fields determines the creation and improvement of fundamentally new approaches to the analysis and management of various technological processes of oil production based on indirect methods of interpreting current geological and field information for making strategic and tactical decisions to rationalize it.This article discusses the formation of stagnant and poorly drained zones of oil deposits due to the redistribution of hydrodynamic flows of reservoir fluids.&#x0D; In order to analyze and evaluate the effectiveness of applying the technology to change the direction of filtration flows in the reservoir under consideration, it is necessary to study the influence of non-stationary processes on oil production.&#x0D; Based on the construction of operational maps of total oil and water production, water cut and the degree of interaction by periods of development, the state of the reservoir system is analyzed and conclusions are made about the characteristic features of the direction of water-oil flows with the subsequent formation of stagnant zones.&#x0D; The proposed approach to decision-making allows to carry out the dynamic regulation of hydrodynamic flows in order to stabilize and reduce oil production losses for the period under consideration and make the necessary decision on the issuance of technological recommendations for the impact on the operation of the exploitation object, taking into account the minimization of energy and resource costs.&#x0D; The proposed method was tested on the example of the analysis of the state of development of one of the fields in Azerbaijan, which is in the final stage of development. As an information array, the dynamics of changes in oil and water flow rates by wells in various periods of development was chosen.

STUDY OF THE ENERGY EFFICIENCY OF THE UDS 214 EXCAVATOR HYDRAULIC SYSTEM

The paper deals with the comparison of the energy consumption of hydraulic systems for controlling the moves of the UDS 214 telescopic excavator. To compare energy losses in the hydraulic circuits for controlling the UDS 214 excavator moves, the flow rates of hydraulic oil were measured with a Hydrotechnik MultiSystem 5060 digital meter in these hydraulic circuits. Firstly, for the state of the UDS 214 excavator before the hydraulic system upgrade and then for the state of the excavator after the hydraulic system innovation. For the each hydraulic circuit, the hydraulic oil flow rates between the Bosch Rexroth A8VO107 double axial piston pump and the Bosch Rexroth 7M8-22 manifold were measured firstly and subsequently between the manifold and the appliance. The total power losses of the individual hydraulic circuits were then determined from the values measured in this way and applying a number of calculations. From these calculated power losses, the efficiency of individual hydraulic circuits was evaluated in the excavator state before and after the hydraulic system innovation.

Implementation of Sustainable Vegetable-Oil-Based Minimum Quantity Cooling Lubrication (MQCL) Machining of Titanium Alloy with Coated Tools

The lubrication capacity and penetration ability of the minimum quantity cooling lubrication-based strategy is linked with lubrication specific parameters (oil flow rates and air pressure), cutting conditions, and chip formation. It points out the complex selection involved in the MQCL-assisted strategy to attain optimal machining performance. Lubrication during metal cutting operations is a complex phenomenon, as it is a strong function of the cutting conditions. In addition, it also depends on the physical properties of the lubricant and chemical interactions. Minimum Quantity Lubrication (MQL) has been criticized due to the absence of cooling parts; MQCL is a modified version where a cooling part in the form of sub-zero temperatures is provided. The aim of this paper was to investigate the influence of different lubrication flow parameters under minimum quantity cooling lubrication (MQCL) when machining aeronautic titanium alloy (Ti6Al4V) using Titanium Aluminum Nitride—Physical Vapor Deposition (TiAlN-PVD) coated cutting inserts. The machining experiments on the MQCL system were performed with different levels of oil flow rates (70, 90, and 100 mL/h) and the performance was compared with the conventional dry cutting and flood cooling settings. A generic trend was observed that increasing the oil flow rate from 70—mL/h to 100 h/h improved the surface finish and reduced thermal softening at a low feed of 0.1 mm/rev. The results revealed that many tool-wear mechanisms such as adhesion, micro-abrasion, edge chipping, notch wear, built-up edge (BUE), and built-up layer (BUL) existed.