Oil Nozzle Research Articles

Physics-data fusion for digital metering of gas-liquid two-phase flow in oil nozzles

Oil well production metering is an important basis for assessing resource reserves and production capacity. Existing metering methods require high investment and involve significant implementation difficulties and high computational costs. A new method of multiphase flow metering method was proposed by combining the fluctuation of pressure drop and temperature difference generated after throttling through the oil nozzle. The throttling equation coupling differential pressure, flow rate and gas fraction was derived. By regulating the gas and liquid superficial velocity, we carried out the experimental test for true nozzle aperture of 10 mm in the loop system, covering various flow patterns. In addition, the deep neural network was constructed for inversion prediction of mass gas fraction. The proposed flow metering equation has an adaptable gas mass fraction range of 0 to 100%, unaffected by the variations in flow patterns, gas-liquid velocities, and system pressure changes. The metering errors of gas mass fraction and mass flow rate is below ±10%. The proposed metering method only relies on the existing temperature and pressure measurement system in the gathering and transportation system, and no additional measuring devices are required. It can be widely used in oil filed production to realize the virtual metering.

ИЗМЕНЕНИЕ ТЕХНИЧЕСКОГО СОСТОЯНИЯ ДВИГАТЕЛЕЙ ЛЕГКОВЫХ АВТОМОБИЛЕЙ В УСЛОВИЯХ ЭКСПЛУАТАЦИИ

This study presents the results of collecting and analyzing statistics on the wear of pistons of budget-class passenger car engines during active operation. The devices and methods of collecting experimental data on the wear of the cylinder-piston group of engines are described. The main ones were: measuring piston wear in four projections with a micrometer MK-100 GOST 6507-90 with a measurement error of ± 0.005 mm and measuring the compression properties of engines with a compressor, the latter showed low accuracy of displaying the technical condition according to the results of the study. The purpose of the study was to verify the effectiveness of common methods of diagnosing internal combustion engines, as well as to identify the dependence of wear on the frequency of oil change, the design features of the engine lubrication system (the presence of oil nozzles cooling pistons). As a result of the study, the inefficiency of the diagnostic method by measuring compression with various devices was revealed, since when the cylinder-piston group wears out with simultaneous wear of the rubber seals of the valves, the oil acts as an additional seal in the engine cylinder and "masks" the actual compression index of the internal combustion engine. In addition, the results of the study confirmed the effectiveness of the presence in the design of the lubrication system of piston cooling oil injectors designed to supply oil when a certain pressure in the lubrication system is reached to a more loaded cylinder wall and piston bottom – based on the revealed fact, it becomes possible to make recommendations on the refinement of the engine design during major repairs at automobile enterprises, service stations by introducing oil injectors into the engine block, which will lead to an increase in the life of the cylinder-piston group and longer trouble-free operation of the engines.

Establishment of Risk Prediction Model for Soil and Groundwater Pollution of Gas Station with Machine Learning Techniques

With the rapid development of network technology and the digital economy, the wave of the era of artificial intelligence has swept the world. Facing the era of big data and artificial intelligence, data-oriented technologies are undoubtedly served as the practical research trend. Therefore, the precise analysis provided by big data and artificial intelligence can provide effective and accurate knowledge and decision-making references for all sectors. In order to effectively and appropriately evaluate the potential risk to soil and groundwater for gas station industry, this study focuses on the potential risk factors affecting soil and groundwater pollution. In the past, our team has evaluated the risk factors affecting the remediation cost of soil and groundwater pollution for possible potential pollution sources such as gas stations, this study proceeds with the existing industrial database for in-depth discussion, uses machine learning technology to evaluate the key factors of pollution risk for soil and groundwater, and compares the differences, applicability and relative importance of the three machine learning techniques (such as neural networks, random forests and support vector machine). The performance indicators reveal that the random forest algorithm is better than support vector machine and artificial neural network. The relative importance of parameters of different machine learning models is not consistent, and the first five dominant parameters are location, number of gas monitoring wells, age of gas station, numbers of gasoline oil nozzle, and number of fuel dispenser for random forest model.

Evaluation of Reservoir Parameters and Well Productivity Based on Production Data: A Field Case in Xinjiang Oilfield, China

The understanding of formation has always been a challenge for field development. In this paper, we evaluate the reservoir parameters and gas well productivity based on production data. The model of nonuniform conductivity of fractures in multistage fracturing horizontal wells (MFHW) is used to interpret the transient pressure data. Binomial and exponential deliverability equations and pressure dimensionless productivity formula are combined to evaluate the gas well productivity. After that, the key factors that influence gas well production are analyzed, and the gas rate vs. oil nozzle is presented. Results show that the fracture half-length and conductivity for high- and low-conductivity fractures, respectively, are obtained, apart from the reservoir pressure, permeability, skin factor, etc. The test time in each oil nozzle is recommended to extend to achieve stability and to obtain a more accurate absolute open flow potential. The findings of this study provides a guidance for the production data analysis of nonuniform conductivity of fractures in MFHW in the future work. And it can help for the better understanding of predicting gas production rates in MFHW.

Performance characteristics of the direct spray oil cooling system for a driving motor of an electric vehicle

In the present work, the performance characteristics of direct spray oil cooling system with spiral, and two full cone nozzles and three cooling oils of mineral oil, dielectric oil and transmission oil are experimentally investigated. The temperature, temperature uniformity, injection pressure, spray resistance, heat transfer coefficient, Nusselt number and spray power consumption are evaluated as the performance characteristics of direct spray oil cooling system. The influences of heating capacities of 1.3 kW and 2.6 kW, nozzle to heating surface distances of 3 cm, 5 cm and 8 cm and cooling oil flow rates of 2 LPM, 3 LPM and 4 LPM are studied on the performance characteristics of direct spray oil cooling system. The lowest maximum surface temperature is obtained for spiral nozzle with 5 cm distance and both full cone nozzles with 8 cm distance. The maximum temperature is maintained within 140 °C at low heating capacity of 1.3 kW and different combinations of nozzles and cooling oils are tested considering flow rate range of 2 LPM to 4 LPM to maintain the maximum temperature within cut-off limit of 200 °C at high heating capacity of 2.6 kW. The maximum performance characteristics are obtained at 4 LPM flow rate followed by 3 LPM and 2 LPM flow rates, respectively in decreasing order. The dielectric oil shows superior performance characteristics compared to mineral oil and transmission oil for all nozzles. Furthermore, in each case of cooling oil, the performance characteristics are excellent for full cone-1 nozzle compared to spiral and full cone-2 nozzles. The combination of dielectric oil and full cone-1 nozzle shows superior performance characteristics of direct spray oil cooling system with heat transfer coefficient of 67420.20 W/m2-K, Nusselt number of 2385.64, spray resistance of 0.0132 K/W and spray power consumption of 29.73 W. The data base generated for a direct spray oil cooling system will be implemented for cooling of an electric vehicle driving motor.

Influence of pad geometry and method of oil supply on the thermal state of GTE rotor tilting-pad journal bearing

High heat generation in the hydrodynamic wedge is one of the main factors limiting application of pad journal bearings as bearings for rotors of aircraft gas turbine engines. The goal of the research is to study the influence of the oil supply method on the bearing thermal state and to determine the design factors reducing the bearing temperature. The study was carried out with the use of bearings with diameters of 100320 mm with different design of the oil supply: through oil dispensing grooves in the pads, through oil nozzles in the inter-pad space, using lead-in chamfers for the pads, with oil bypass channels. The tasks posed were solved by using volumetric geometric models with the tools of computational fluid dynamics in the ANSYS CFX package in which differential equations describing the model are solved by the finite element method. The patterns of temperature and pressure distribution over the surface of the lower, most loaded bearing pad were obtained for various options of oil supply and different geometry of bearing pads; values of the bearing load carrying capacity, maximum pressure in the working gap, the oil mass flow through the elements of the oil supply; dependences of the bearing static performance on the distance between the shaft and nozzles. Oil supply through oil dispensing grooves made in pads is a factor that negatively affects the bearing thermal state, which is associated with so-called locking of the working gap. It is shown that implementation of oil supply through the space between the pads is more efficient. The use of a lead-in chamfer with plain inserts simplifies oil supply to the working gap. The design solutions described make it possible to reduce the maximum oil temperature in the bearing by 36 degrees Celsius.

Generation of ash particles from different lube oil mists

Ash and soot particles are generated during engine combustion and are deposited in particulate filters. In order to understand the basic processes that occur in a particulate filter during the filtration process the particles have to be generated quickly and replicably. In this study, fundamental investigations are conducted on the generation of ash particles independently of an engine to produce a defined aerosol. The formation of ash particles from engine oils with differences in sulfate ash content (SAC; 0.7%, 2.6%, 4.5%) as well as the variation of process parameters (oil temperature, nozzle volume flow) are investigated. The ash particles are produced by nebulizing engine oil and a subsequent thermal conversion in a furnace. The SAC of the oil does influence the ash particles that are generated. With the increase of the SAC, the ash mass flow and the number weighted median diameter increase. Raising the nozzle volume flow as well as the oil temperature leads to an increase in total number concentration and mass flow of the ash particles. The number median diameter of the oil mist and ash particles decrease with the increase of oil temperature and nozzle volume flow. For the fast loading of a particulate filter, the SAC of the oil should be 4.5%. The oil temperature and nozzle volume flow should be set at 30 °C and 6 L·min−1. In conclusion, the ash generation method can be used for the rapid loading of a particulate filter.

Analysis of Grooves Used for Bearing Lubrication Efficiency Enhancement under Multiple Parameter Coupling

Adding axial groove structures to the surface of bearing inner ring is an effective way to enhance the bearing lubrication efficiency. In this paper, the angular contact ball bearing H7006C was taken as the research object, and through visual simulations and quantitative experiments, systematic analyses and discussions were carried out to find out the relationship between groove-enhancing performance and working conditions. Firstly, simulation models of standard bearing and groove-added bearing were established. By combining the Volume of Fluid (VOF) model, the enhancing mechanism of grooves was found. Secondly, the trend of groove-enhancing performance with the change of rotation speed was studied through simulations and quantitative experiments. On this basis, through multiple parameter coupling, the effects of oil supply amount and nozzle diameter on the groove performance were discussed. The results show that the bottom oil layer is the key for grooves to achieve the lubrication efficiency enhancement, and its distribution can reflect the groove-enhancing performance. The groove width that best adapts to the change of working conditions increases with the increase of oil supply amount and nozzle diameter. To maintain the stability of bottom oil layer, the nozzle diameter should be larger than the groove width. This research is of great significance to the application of grooves in the lubrication efficiency enhancement of high-speed bearing.

The Electrode Wear and Effective Energy Detection in Micro-EDM Drilling of Micro-hole Array

With the micro-hole array structure more and more used in industrial areas, such as oil nozzle, spinneret and so on, its machining accuracy significantly affects the performance of the product. In the machining of micro-hole array by micro-EDM drilling, unavoidable tool electrode wear is one key factor affecting machining geometric and dimensional accuracy, and the effective energy of the discharge gap directly determines the amount of electrode wear. In present study, the characteristics of electrode wear and gap effective discharge energy were explored to meet the requirements of machining accuracy of micro-hole array machining. The effect of pulse generator parameters and electrode eccentric radius on electrode wear were concerned, and the electrode wear was reduced by optimizing pulse generator parameters and electrode eccentric radius. The geometry evolution rule of electrode was investigated, and the electrode wear model was established based on the electrode wear characteristic. The experimental result show that the electrode tip morphology tended to be stable and the axial wear of the tool electrode could be compensated evenly. In order to realize the accurate calculation of the gap effective discharge energy, a gap effective discharge energy detection system was built based on Lab VIEW. And the variation rule of gap effective discharge energy was obtained by micro-hole array machining experiment. In addition, the relationship between electrode wear and gap effective discharge energy was also studied in this paper. It was found that there was a parabolic relationship between electrode wear and effective energy before electrode wear was stable, and there was a linear relationship between them after electrode wear was stable.

Research and method of air burst fracturing

At present, shale gas pressure fracturing volume development technology tends to be mature, shale gas backlog fracturing ends and enters the trial production stage. Due to the improper control of oil nozzle or its causes, the output drops sharply, or the drainage in the production process makes the funnel effect near the wellbore zone, resulting in the closure of the main fracture passage near the wellbore. However, the far-end complex sealing network structure produced by volume fracturing technology is still not fully closed, or secondary fractures occur in the absence of support for the original wellbore fractures or new complex fractures occur in the vicinity of the wellbore. The simple use of high-energy gas fracturing requires low cost, safety and simple and efficient characteristics, and the requirements for surface equipment are not too high. Existing methods mainly include well testing, sand washing by coiled tubing, gas lifting by coiled tubing, wellbore plugging removal, pumping and drainage by supplementary pressure well operator, etc. They can not fundamentally solve the need of closing or reopening new fractures in wellbore, and can not make new complex unclosed fractures near wellbore zone (without secondary fracturing). If the investment of surface equipment for secondary fracturing is similar to that of the first volume fracturing, and the investment is similar, the more complex situation will arise because of filtration and other reasons. At present, low concentration methane in air and wellbore is used to oxidize and exothermic to produce CO2 and H2O, and release energy at the same time. Temperature and pressure are the main means of energy in limited space. High energy gas formed after volume work can help to reopen the original fracture and form a new type of high energy gas fracturing method by means of air ignition and explosion, because the effect of high energy gas fracturing is not affected by stress, new cracks can be produced, and this crack can avoid overlapping with previous cracks. In particular, it can be pointed out that due to the improvement of thermal recovery of heavy oil and other means, the ground operation equipment has the commonality, and reasonable optimization of the construction plan can achieve the established purpose.

Experimental study on oil supply efficiency of under-race lubrication based on radial oil scoop

Under-race lubrication is an efficient lubrication method of aeroengine bearings for achieving high DN values. In this paper, an experimental study on oil supply efficiency of under-race lubrication structure based on high rotation speed and small size radial oil scoop is carried out. The influence of rotation speed, nozzle diameter and oil temperature on oil supply efficiency are analysed. The research results can be used to guide the design of oil nozzle and under-race lubrication structure.

Micro-electrode wear and compensation to ensure the dimensional consistency accuracy of micro-hole array in micro-EDM drilling

The micro-hole array machined by microelectrical discharge machining (micro-EDM) has been widely used in industrial fields, such as inkjet nozzle, oil nozzle, spinneret, and so on. However, it is difficult to guarantee the dimensional consistency accuracy of micro-hole array. In the present study, the characteristic and compensation strategy of microelectrode wear were explored to meet the requirements of dimensional consistency accuracy of micro-hole array machining. The effect of pulse generator parameters on microelectrode wear was studied, and the microelectrode wear was reduced by optimizing pulse generator parameters. The geometry evolution rule of microelectrode was investigated, and the microelectrode wear model was established based on the wear characteristic of microelectrode. By analyzing the wear characteristic of microelectrode, single-hole quantitative compensation strategy was adopted during the machining process. Meanwhile, grouping detection variable compensation strategy was proposed to adjust axial position of microelectrode periodically in order to eliminate the cumulative compensation errors. The array of 256 (16 × 16) micro-holes with an average diameter of 45.28 μm was machined on a 50-μm-thick stainless steel. The dimensional consistency accuracy of micro-hole array was assured by showing a standard deviation of 0.15 μm. In addition, the array of 64 (8 × 8) micro-holes and the array of 25 (5 × 5) micro-holes with an average diameter of less than 20 μm were machined to explore the performance of micro-hole array machining with smaller size, and the dimensional consistency accuracy was shown by the standard deviation of 0.25 and 0.4 μm, respectively.

The Tool Electrode Wear and Gap Fluid Field Simulation Analysis in Micro-EDM Drilling of Micro-hole Array

With the micro-hole array structure has been widely used in industrial areas, such as inkjet printer nozzle, oil nozzle, spinneret and so on, its processing accuracy significantly affects the performance of the product. In the machining of micro-hole array by micro-EDM drilling, unavoidable tool electrode wear and frequent occurrence of abnormal discharges such as short circuit and secondary discharge caused by the difficulty in removing discharge debris are the main factors affecting machining geometric and dimensional accuracy. In this study, the flow velocity simulation analysis of working fluid playing a crucial role in the flushing of discharge debris and the experimental study on the axial wear of tool electrode are explored in order to ensure the machining accuracy of micro-hole array. By changing the parameters of tool electrode diameter and machining depth in the fluid field simulation analysis, the gap velocity distribution under different depth-diameter ratios is obtained. Simulation results show that the gap flow velocity decreases with depth-diameter ratios increasing. For different depth-diameter ratios in the micro-hole array processing, the tip morphology evolution and the wear of tool electrode are considered, which show that the electrode tip morphology tends to be stable and the axial wear of the tool electrode could be compensated evenly. In addition, the characteristics of tool electrode axial wear are explained based on the simulation results of gap flow field, which verifies the effectiveness of the flow field simulation and provides a reference for formulating electrode wear compensation strategy and improving machining accuracy to some extent.

Influence of oil nozzle structure parameters on oil injection direction

PurposeThe purpose of this paper is to provide an analytical method of jet flow injection direction and to determine the influence of oil nozzle structure parameters on oil injection direction, thus providing the design method of oil nozzle structure parameters.Design/methodology/approachA model of oil injection loss is established to analyze the influence of oil nozzle structure parameters on oil injection direction. The computational fluid dynamics method is used to simulate the process of the deviation of jet flow injection direction. The deviation of jet flow injection direction with different oil nozzle structure parameters is calculated and their variations are obtained. Moreover, the deviation of jet flow injection direction with different oil nozzle structure parameters is tested to verify the analysis results.FindingsResults indicate that radial velocity caused the deflection of the oil injection direction. The deviation of jet flow increased as the nozzle slenderness ratio decreased. The design method of the nozzle slenderness ratio (greater than five) is proposed to avoid the deviation of injection direction, and it is necessary to consider the matching between the nozzle slenderness ratio and pipeline pressure. The computational results coincide well with the experimental results.Originality/valueThe research presented here analyzed the influence of oil nozzle structure parameters on oil injection direction via a numerical analysis method. It also leads to a design reference guideline that could be used in jet lubrication, thus controlling the direction of the injection jet accurately.

Cooled Pads for Tilting-Pad Journal Bearings

Tilting-pad journal bearings (TPJBs) are widely installed in rotating machines owing to their high stability, but some drawbacks can be noted, such as higher cost with respect to cylindrical journal bearings and thermal issues. High temperatures in the pads correspond to low oil-film thicknesses and large thermal deformations in the pads. Therefore, the restriction of the maximum temperature of the bearing is a key aspect for oil-film bearings. The temperature reduction is generally obtained by adopting higher oil inlet flowrates or suitable oil nozzles. In this paper, the idea of using cooled pads with internal channels in which an external cooling fluid is circulated will be applied to a TPJB for the first time. The three-dimensional TEHD model of the TPJB, equipped with a cooled pad, will be introduced, and the results of the numerical simulations will be discussed. Several analyses have been performed in order to investigate the influence of cooling conditions, such as the type, flowrate, inlet temperature and number of cooled pads. Two types of pad geometry with different cross-sections of the cooling circuit, namely, circular and six-square multi-channel sections, have been compared to the reference bearing with solid pads. Simple experimental tests were performed by means of a test rig equipped with a cooled pad bearing obtained with the additive manufacturing process, thus showing the effectiveness of the solution and the agreement with the predictions.

Internal Combustion Engine Fault Identification Based on FBG Vibration Sensor and Support Vector Machines Algorithm

State monitoring and fault diagnosis of an internal combustion engine are critical for complex machinery safety. In the present study, a high-frequency vibration system was proposed based on Fiber Bragg Grating (FBG) cantilever sensor and intelligent algorithm. Structural vibration signal containing fault information of engine valves and oil nozzle was identified by FBG sensors and preprocessed using wavelet decomposition and reconstruction. Moreover, vibration energy was taken as fault characteristics. Subsequently, a fault identification model was built based on multiclass υ-support vector classification (υ-SVC). Experimental tests on the valve fault and fuel injection advance angle fault were performed and presented to verify the efficacy of the proposed approach. The results here reveal that the proposed method exhibits excellent fault detection performance for ICE fault identification. Furthermore, the proposed method can achieve higher performance than other methods in the fault identification accuracy.

3D numerical simulation of clastic reservoir with bottom water drive using various ior techniques for maximizing recovery

In most reservoirs with oil rims, as the production begins, the gas–oil and oil–water fluid interfaces start deforming because of the imbalance between viscous and gravitational forces, leading to coning or cusping. This can be overcome using proper withdrawal rate, offset from water–oil contact and horizontal length. Further smart horizontal wells require optimization of nozzle size and compartment length also. To see the effect of these parameters on recovery, a three-dimensional geological model of a clastic reservoir from Upper Assam Basin has been used. This model was history matched for a period of 16 years on 46 wells. After successful validation of model on field scale and well level, performance prediction was carried out to see the effect of withdrawal rate, offset from water–oil contact, horizontal length, compartment length and nozzle size using vertical/horizontal and ICD completion. From the analysis, it is evident that application of advanced well completion, ICD, is suitable for such reservoir. Depending on the scenario, maximum cumulative oil production was obtained from ICD wells with 1.08 MMm3 compared to vertical well with cum oil production of 0.63 MMm3. Economic analysis has been carried out for the examined scenarios.

Performance of mechanical co-extraction of Jatropha curcas L. kernels with rapeseed, maize or soybean with regard to oil recovery, press capacity and product quality

Jatropha curcas L. shelled seeds (kernels) have been gaining attention as protein source due to their high protein content. However, due to the soft texture, screw pressing the kernels resulted in a low performance, which was indicated by high residual oil content in the press cake. In order to overcome the low oil recovery from the extraction process, J. curcas kernels blended with rapeseed, maize or soybean as additives were studied. The blending effects on the performance of mechanical oil extraction, along with the quality of oil and press cake were evaluated. To achieve the maximum oil recovery, blending ratio, nozzle diameter and screw speed were optimised using response surface methodology. Higher blending ratio showed significantly higher oil recovery (p<0.05). Soybean blend exhibited highest oil recovery of 91.0%. Specific energy requirement and oil recovery were negatively correlated with throughput. Oil from maize blend generated the highest acid value and free fatty acid of 8.39mg KOH/g and 4.19%, respectively. Carbon residue of the sedimented oil from all material blends fulfilled the standard threshold of German Institute for Standardization (DIN 51605). The highest press head temperature of 104.6°C was observed from soybean blend. The ash content of the press cake from pure J. curcas kernels was lower than the other material blends. Press cake from soybean blend revealed low pepsin insoluble nitrogen and high crude protein content, pepsin plus trypsin digestibility and available lysine. Regarding the antinutritional factors, press cake from rapeseed blend showed highest phytate and trypsin inhibitors of 4.1% and 22.7mg trypsin inhibited/100mg sample, respectively. In terms of oil recovery and press cake quality, soybean appears to be the most suitable additive compared with rapeseed and maize.

Pollutant Emissions from Boilers with Different Oil Nozzles

Pollutant Emissions from Boilers with Different Oil Nozzles

Thermal effect of lubricating oil in positive-displacement air compressors

The isentropic efficiency of positive-displacement compressors may be improved in order to follow an increasing demand for energy savings. This work analyzes the thermal effect of the lubricating oil presence in the air during compression with the scope of exploiting it as a thermal ballast to mitigate both the gas temperature rise and its compression work. The bibliographic review shows that other authors suggested that oil can have positive effects if properly injected. Here an energy balance analysis is executed with the scope of deriving relations for the gas–liquid compression in analogy with those typical for the gas-only compression and of confirming that ideally the liquid presence may have beneficial effects, making the gas–liquid compression even better than 1- and 2-time intercooled gas compressions. Given these positive results, a heat transfer analysis is conducted to model the thermal interaction between gas and oil droplets within a mid-size rotary vane air compressor. A droplet diameter of the order of 100 μm leads to large reductions of both temperature increase and compression work: air can exit the discharge port at a temperature as low as 60 °C and compression work can be lowered by 23–28% with respect to conventional compressors. Finally, a test rig is constructed and operated to investigate a large-flow and large-angle oil nozzle taken from the market showing that, at the operating conditions of a compressor, oil breaks up into small droplets and undefined structures with large exchange surfaces.