Inlet Oil Research Articles

High Precision Synchronous Mechanical Motion Hydraulic Compensation Method

Auxiliary hydraulic system being based on sensor detection is designed to control two execution parts synchronization precision work in main hydraulic lines. To design a servo drive control valve with three working positions, its each position have an oil inlet and two outlets. This valve can come true compensation flow for the single cylinder or all cylinders of the main lines at the same time. Have designed a device is used to control the auxiliary valve-control compensating device by the grating sensor comparison circuit.

Analytical Research on Characteristics of Deep-shallow Journal Bearings with Orifice Restrictors

Hydrodynamic-static hybrid journal bearing with orifice restrictor is a kind of bearing that the throttling effect is realized by orifice restrictor and the second throttling effect is realized by shallow recess. There is a shortage of the existing theory that can not study the load characteristics which are affected by the recess structure parameters and operation parameters in analytical method. It is inconvenient for engineers to use the computational fluid dynamics software, due to the disadvantage of long period of calculation. On the assumption of subsection linearization of pocket pressure, a method is proposed to analyze the deep-shallow bearing characteristics, such as load capacity, bearing stiffness, flow rate and temperature ascending relationship. The analytical method is used to study bearing characteristics with the different structure parameters and working parameters, such as supply pressure, spindle speed, oil inlet aperture, shallow depth and initial oil film thickness. It is demonstrated that stiffness is close to the biggest value and temperature rising is close to the lowest one, when the shallow depth is thicker than the initial oil film by twice or three times, in the conditions that all other structural parameters and operating parameters are unchanged. The reliability of the analytical method has been verified by comparing experimental results with the analytical values.

S1150305 油圧ベーンポンプのカムリングの温度と振動の計測 : ベーンの離間現象との関連性

Temperature distributions and vibration acceleration of the cam-ring of a hydraulic vane type test pump were measured simultaneously under real operating conditions. Four thermocouples were embedded in the cam-ring and the side-plate; one acceleration pickup was implanted in the cam-ring. A hydraulic oil with ISO VG32 was used as the test fluid and the inlet oil temperature was specified at 30 to 50℃. The discharge pressure was up to 10 MPa and the rotational speed was set between 6.7 and 15 rps. In the vicinity of the condition when the vane tip detached from the sliding surface of the cam-ring, the temperatures and acceleration were measured. The salient conclusions are as follows: The vane-tip detachment was appeared at lower discharge pressure for higher oil temperature and lower rotational speed. The detachment was caused marked changes in vibration and temperature of the cam-ring.

Monitoring the Petrol Engine Oil Viscosity: Investigation of the Capability of the Metal Magnetic Memory Technology

An engine lubrication system is one of the main factors which influence engine life span, and it can be easily determined based on the viscosity of the engine oil. The current and common technology for monitoring and the determination of the engine oil viscosity using the oil analysis method is found to be uneconomical and ineffective. On the same vein, this paper presents an investigation of the capability of the Metal Magnetic Memory (MMM) technology in the processes of monitoring and detecting the variation of petrol engine lubricant viscosity via in-situ operation. A few investigations were conducted on a Robin Engine 126 cc EX 13D single cylinder of four strokes with water cooling. One multi-grade engine lubricant oil condition has been put to the test; namely, SAE 15W-40. During the investigation of the petrol engine oil viscosity, the magnetic field signal is captured when the engine oil in-service age is 0 km (fresh oil), 250 km, 500 km, 750 km and 1,000 km, with the crankshaft rotational speed of 2500 rpm at three different locations such as at the Bottom Dead Centre (BDC), oil sump A (engine oil inlet), and oil sump B. The lubrication condition in the petrol engine is successfully monitored based on the magnetic field signatures generated by the interaction between the piston surface and the layer of the lubricant during the time when the engine was in operation. The generated MMM signatures were captured using a type 2 scanning device with two ferroprobe sensors and a length measuring sensor and recorded by the TSC-3M-12 type device. The waveform signatures captured were displayed as length domain signal and then were analysed using the MATLAB software to determine the magnetic field energy (EH). In addition, the real viscosity value at room temperature was determined using the Haake Viscotester 6 L, each time after the magnetic field signal was captured. The results of these studies have shown that the magnetic field energy (EH) is inversely proportional to engine oil viscosity. Finally, the MMM technology can be utilised in promoting economic development and effective planning of the maintenance schedule of the petrol engine oil.

The Characteristics of Boiling Heat Transfer of R-600a-oil Mixture in a Circular Tube with Porous Inserts

This investigation was carried out to study the characteristics of boiling heat transfer for hydrocarbon refrigerant R600a (isobutane)/oil mixtures flowing in a circular pipe within dispersed-copper porous inserts. The oil was the EMKARATE RL 32H with a viscosity 150 SUS. The test was conducted at a saturation temperature of 10 , vapor qualities from 0.076 to 0.87, inlet oil concentration from 0 to 3 mass% oil, mass flux of 120 1100 and heat flux of 12-65 . The effects of the concentration of the refrigerant/oil mixtures, and the sizes of inserts on the heat transfer of R-600a for present study were presented.

Prediction of Chemical Inhibitors Efficiency for Reducing Deposition Thickness Using Artificial Neural Network

Prediction of efficiency of chemical inhibitors to mitigation of deposition thickness is a key to developing crude oil transportation process. In this work, a feed-forward artificial neural network (ANN) algorithm has been applied to predict the influence of the mitigation effect of ethylene-co-vinyl acetate (EVA) copolymer and its combination with chloroform (C), acetone (A), P-xylene (PX), and petroleum ether (PE) on the deposition thickness in the pipeline. An optimized three-layer feed-forward ANN model using properties of the oil pipeline such as: inlet oil temperature, environmental (coolant mixture) temperature, oil Reynolds numbers; properties of injected inhibitor such as molecular weight, boiling point, and amount of injection; and time is presented. Different networks are considered and trained using 62661 data sets; the accuracy of the network is validated by 20888 testing data sets. To verify the network generalization, 29 different experiment data sets of four different set of inhibitors have been considered. It is found that the proposed ANN model is an alternative to experimentation and predicts deposition thickness without experimentation, vast information, and tedious and time-consuming calculations.

TURBYLEC: DEVELOPMENT AND EXPERIMENTAL VALIDATION OF AN INNOVATIVE CENTRIFUGAL OIL – WATER SEPARATOR

ABSTRACT An innovative oil/water separator (TURBYLEC) has been developed in the frame of the HOVERSPILLTM European project (Fast Air Cushion platform for Oil Spill Remediation), partly funded by the European Commission's 7th Framework Program. Conventional separation solutions are not appropriate to the remediation scenarios targeted by the HOVERSPILLTM project, mainly because low weight and compactness are absolutely required for transportation on a hovercraft. Namely, high separation efficiency, imposed to satisfy environmental legislation for water release, is particularly difficult to achieve with a compact separator when skimmed flow rate, oil content and density contrast are submitted to large variations. This paper describes the development of a customized patented centrifuge separator devoted to the specific needs of the HOVERSPILLTM project. Conceptual studies, prototype manufacturing and experimental validation are described. The TURBYLEC prototype tested at CEDRE's facilities has a bulk (size and weight) compatible with its integration on the HOVERSPILLTM platform. Tests results show that TURBYLEC matches with expected use (i.e. downstream of a non-selective skimmer). In this configuration, TURBYLEC separator shows very good oil / water separation performances for inlet oil contents up to 25%. In this range of operating conditions its cut diameter has been evaluated to 60 μm. In order to achieve the same separation performances as with TURBYLEC, which weighs only 70 kg (with liquids), it would be necessary to install an 8 m3 gravity separator. TURBYLEC separator has been developed for a very specific duty (i.e. for integration on an Hovercraft for Oil Spill remediation). Nevertheless, its proven performances render it particularly attractive, as a standalone system, for many other specific tasks in the field of oil spill remediation. It could also interest various other water treatment applications.

Optimization of Fish Oil Spray Drying Using a Protein:Inulin System

The aim of this work was to investigate the use of an unconven-tional polymeric material, inulin, in fish oil spray drying. The influence of inlet air temperature, oil load, and carrier substitution (whey protein isolate by inulin) on the physical properties of particles containing fish oil was investigated. Increasing the oil load caused an increase in the surface oil; however, the presence of inulin favorably decreased the particle surface oil when a high oil lad was applied. The parameters hygroscopicity and wettability were also influenced by the inulin fraction. The higher inlet air temperature produced larger particles with lower densities. The best operating conditions were determined to be an air temperature of 185°C, a 40% inulin fraction, and a 6% oil load. The results indicate that inulin is an alternative carrier in the fish oil spray-drying process.

Thermodynamic analysis and optimization of a solar-powered transcritical CO2 (carbon dioxide) power cycle for reverse osmosis desalination based on the recovery of cryogenic energy of LNG (liquefied natural gas)

A solar-powered transcritical CO2 (carbon dioxide) power cycle for reverse osmosis desalination based on the recovery of cryogenic energy of LNG (liquefied natural gas) is proposed. The system consists of a solar collector subsystem, a transcritical CO2 power cycle subsystem, a LNG subsystem and a RO (reverse osmosis) desalination subsystem. A thermal storage unit is introduced into the system to guarantee continuous and stable operation of the system. A mathematical model is developed to simulate the system based on several assumptions. The effects of several key thermodynamic parameters on the system performance are examined based on the performance criteria, including daily exergy efficiency, daily mechanical work output and daily fresh work output. Parametric optimization is conducted by genetic algorithm to maximize the daily fresh water output. The results show that the CO2 turbine inlet pressure has an optimal value to reach the daily maximum exergy efficiency under the given conditions. The daily exergy efficiency could decrease with an increase in condenser temperature, and increase with an increase in mass flow rate of oil and NG turbine inlet pressure. Through parametric optimization, the system can reach the daily exergy efficiency of 4.90% and provide 2537.33 m3 fresh water per day under the given conditions.

Direct liquid-immersion cooling of concentrator silicon solar cells in a linear concentrating photovoltaic receiver

Direct liquid-immersion cooling of solar cells using dimethyl silicon oil is proposed as a heat dissipation solution for linear CPV (concentrating photovoltaic) systems. To reduce the liquid holdup, a narrow rectangular channel receiver was designed and its heat transfer performance was investigated experimentally at an energy flux ratio of 9.1 suns. Long-term stability of mono-crystalline concentrator silicon solar cells immersed in dimethyl silicon oil with viscosity of 2 mm2/s was monitored under real climate conditions. Experimental results show that the liquid-immersion cooling capacity in the designed receiver is favorable. The cell temperature can be controlled in the range of 20–31 °C at a 910 W/m2 DNI (direct normal irradiance), 15 °C silicon oil inlet temperature and Re numbers (Reynolds) variation from 13,602 to 2720. The cell temperature distribution is quite uniform, and a general correlation of Nu number (Nusselt) was obtained. The electrical performance of the cells immersed in the silicon oil is stable and no obvious efficiency degradation was observed after immersed for 270 days.

Intensification of heat transfer in a liquid film evaporator

AbstractInfluence of the heat exchanger shape on the heat transfer efficiency investigated. Heat transfer efficiency of two vertical pipe-in-pipe heat exchangers, one with a straight wall and the other with a twisted wall were compared. Both heat exchangers worked on the principle of liquid falling film. Electric transformer oil was used as the heated liquid and water vapor at atmospheric pressure was used as the heating agent. Oil was just heated, not evaporated during the experiments. Oil inlet and outlet temperature were measured at six different oil mass flows. Heat flux and heat flux density in the straight- and twisted-wall heat exchangers were compared. Mathematical model was built to verify the possibility of the oil outlet temperature prediction.

Rotordynamic Evaluation of Full Scale Rotor on Tilting Pad Bearings with 0.1 and 0.3 Preload

A system identification method for rotating machinery stability evaluation is investigated based on sine sweep excitation testing with electromagnetic actuator. The traditional MIMO FRF is transformed into dFRF from real number field to complex field with a transformation matrix, eliminating the influence of forward and backward modal overlap and providing higher accuracy to identify rotor’s first forward modal parameters using the rational polynomial method. The modal parameters are acquired for stability estimation. Furthermore, two sets of bearing with preloads of 0.1 and 0.3 under both load-on-pad (LOP) and load-between-pad (LBP) conditions are investigated. The effects of oil inlet pressure (1.0 bar–1.75 bar) and temperature (43°C–51°C) on the stability of rotor are investigated in detail. Results indicate that the stability of rotor will be improved by increasing the oil inlet temperature and pressure. It is found that the rotor is more stable on bearing with 0.1 preload than that of 0.3 preload. Load-on-pad provides more damping to rotor than load-between-pad. The method and outcomes of this paper can provide both theory basis and technology foundation for improving the rotor stability of centrifugal compressors.

Numerical Investigation of Temperature Distribution in an Eroded Bend Pipe and Prediction of Erosion Reduced Thickness

Accurate prediction of erosion thickness is essential for pipe engineering. The objective of the present paper is to study the temperature distribution in an eroded bend pipe and find a new method to predict the erosion reduced thickness. Computational fluid dynamic (CFD) simulations with FLUENT software are carried out to investigate the temperature field. And effects of oil inlet rate, oil inlet temperature, and erosion reduced thickness are examined. The presence of erosion pit brings about the obvious fluctuation of temperature drop along the extrados of bend. And the minimum temperature drop presents at the most severe erosion point. Small inlet temperature or large inlet velocity can lead to small temperature drop, while shallow erosion pit causes great temperature drop. The dimensionless minimum temperature drop is analyzed and the fitting formula is obtained. Using the formula we can calculate the erosion reduced thickness, which is only needed to monitor the outer surface temperature of bend pipe. This new method can provide useful guidance for pipeline monitoring and replacement.

Numerical and Experimental Stability Investigation of a Flexible Rotor on Two Different Tilting Pad Bearing Configurations

Rotordynamic stability is crucial for high performance centrifugal compressors. In this paper, the weighted instrumental variable (WIV) based system identification method for rotating machinery stability is investigated based on a sine sweep forward excitation with an electromagnetic actuator. The traditional multiple input multiple output (MIMO) frequency response function (FRF) is transformed into a directional frequency response function (dFRF). The rational polynomial method (RPM) combined with WIV is developed to identify the rotor’s first forward mode parameters. This new approach is called the COMDYN method. Experimental work using the COMDYN method is carried out under different rotating speeds, oil inlet temperatures, and pressure conditions. Two sets of bearings with preloads 0.1 and 0.3 are investigated. A numerical rotor-bearing model is also built. The numerical results correlate reasonably well with the experimental results. The investigation results indicate that the new method satisfies the desired features of rotating machine stability identification. Furthermore, the system log decrement was improved somewhat with the increase of oil inlet temperature. The increase of oil supply pressure affects the rotor-bearing system stability very slightly. The results of this paper provide new and useful insights for potentially avoiding instability faults in centrifugal compressors.

Mathematical model and experiment validation of fluid torque by shear stress under influence of fluid temperature in hydro-viscous clutch

The current design of hydro-viscous clutch(HVC) in tracked vehicle fan transmission mainly focuses on high-speed and high power. However, the fluid torque under the influence of fluid temperature can not be predicted accurately by conventional mathematical model or experimental research. In order to validate the fluid torque of HVC by taking the viscosity-temperature characteristic of fluid into account, the test rig is designed. The outlet oil temperature is measured and fitted with different rotation speed, oil film thickness, oil flow rate, and inlet oil temperature. Meanwhile, the film torque can be obtained. Based on Navier-Stokes equations and the continuity equation, the mathematical model of fluid torque is proposed in cylindrical coordinate. Iterative method is employed to solve the equations. The radial and tangential speed distribution, radial pressure distribution and theoretical flow rate are determined and analyzed. The models of equivalent radius and fluid torque of friction pairs are introduced. The experimental and theoretical results indicate that tangential speed distribution is mainly determined by the relative rotating speed between the friction plate and the separator disc. However, the radial speed distribution and pressure distribution are dominated by pressure difference at the lower rotating speed. The oil film fills the clearance and the film torque increases with increasing rotating speed. However, when the speed reaches a certain value, the centrifugal force will play an important role on the fluid distribution. The pressure is negative at the outer radius when inlet flow rate is less than theoretical flow, so the film starts to shrink which decreases the film torque sharply. The theoretical fluid torque has good agreement with the experimental data. This research proposes a new fluid torque mathematical model which may predict the film torque under the influence of temperature more accurately.

MODELING OF A VAPOR-COMPRESSION CHILLER FOR PERFORMANCE STUDY

A variable speed refrigeration system was designed to supply chilled liquid for cooling high-power electronic devices to maintain the temperature at an acceptable level. Fin-plate heat exchangers were adopted to save space. The paper presents the simulation of the refrigeration system to study its steady performance. The simulation model was developed by using a detailed thermodynamic model and containing a series of heat transfer correlations for specific parameters. The cooling capacity of the refrigeration system under different working conditions is investigated. The simulation results keep in agreement with experimental data. The cooling capacity increases with the rise of cooled oil inlet temperature. Besides, condenser cooling liquid inlet temperature affects the cooling capacity greatly. The cooling capacity and the coefficient of performance (COP) of the system under different motor speeds are studied subsequently. The simulation results have been validated by experiments. The mean relative error of the cooling capacity and the COP between simulation results and experimental data is 12.6% and 4.8%, respectively. The results can be used to develop control strategy for regulating refrigeration flow rate to offer adequate cooling capacity and supply cooled oil of constant temperature.

Removal of oil from electric desalting wastewater using centrifugal contactors

To solve the problem of over-standard oil content in electric desalting wastewater (EDW), a new process for removing oil was designed based on centrifugal contactors. In addition, an industrial sidetrack tester was established. The effects of rotor speed, inlet flow rate, water temperature, oil content, and crude oil density on separating performance were studied. Results show that oil removal efficiency increases with the decreasing inlet flow rate, increasing oil concentration, or decreasing oil density. At 50–90 °C, oil removal efficiency remains stable but initially rises first and then falls with increasing rotor speed, whereas the water content in separated waste oil (SWO) initially decreases and then increases. Oil concentrations ranging from 4000 mg/L to 60,000 mg/L can be reduced to below 200 mg/L using centrifugal contactors. The proposed process is highly efficient for separating oil from EDW.

Influence of Clearances and Thermal Effects on the Dynamic Behavior of Gear-Hydrodynamic Journal Bearing Systems

A global model of mechanical transmissions is introduced which deals with most of the possible interactions between gears, shafts, and hydrodynamic journal bearings. A specific element for wide-faced gears with nonlinear time-varying mesh stiffness and tooth shape deviations is combined with shaft finite elements, whereas the bearing contributions are introduced based on the direct solution of Reynolds' equation. Because of the large bearing clearances, particular attention has been paid to the definition of the degrees-of-freedom and their datum. Solutions are derived by combining a time step integration scheme, a Newton–Raphson method, and a normal contact algorithm in such a way that the contact conditions in the bearings and on the gear teeth are simultaneously dealt with. A series of comparisons with the experimental results obtained on a test rig are given which prove that the proposed model is sound. Finally, a number of results are presented which show that parameters often discarded in global models such as the location of the oil inlet area, the oil temperature in the bearings, the clearance/elastic couplings interactions, etc. can be influential on static and dynamic tooth loading.

A microscale combustor recuperator and oil heat exchanger – design and thermofluidic characterization

A two-dimensional numerical model of an integrated microscale hydrogen–air catalytic combustor, recuperator, and oil heat exchanger is presented. Catalytic combustion occurs on the walls of the microchannel in the presence of a platinum catalyst. The performance of the combustor is documented using validated CFD simulations for variations in geometric and fluidic parameters. Varied geometric parameters include the length and location of the catalyst bed, length of the device, and the height of the combustion channel. Varied fluidic parameters include the oil inlet temperature, flow rates of oil and reactants, and the equivalence ratio of the reactants. Performance is characterized using a global efficiency, heat transfer effectiveness and hydrogen conversion. The parametric variations are captured non-dimensionally as variations in Damkohler and Peclet numbers, which are in turn used to describe the changes in hydrogen conversion and efficiency. Performance maps for hydrogen conversion and pressure drop in the combustion channel are presented based on values of the Damkohler and Peclet numbers and regions of desired operability of the combustor are identified.

Characteristics of integrated micro packed bed reactor-heat exchanger configurations in the direct synthesis of dimethyl ether

The performance of three integrated micro packed bed reactor-heat exchangers (IMPBRHEs) for direct DME synthesis over physical mixtures of CuO–ZnO–Al2O3 and γ-Al2O3 catalysts was experimentally investigated. Systematic variations in reactor and slit dimensions and configuration were analyzed in terms of thermal behaviour, mass transfer, pressure drop and residence time distribution (RTD). The pressure drop was always small (<0.12bar) relative to the total pressure (50bar), and linear dependence with GHSV confirms the predicted laminar flow for Re=0.1–2. A narrow RTD was estimated by the dispersion analysis. Careful temperature measurements confirmed that the reaction temperature is mainly controlled by the oil heat exchange to give a practically uniform temperature profile for set inlet oil temperatures of 220–320°C. The micro packed beds were found free of the internal as well as external mass transfer limitations, as showed by no significant change in the CO conversion and DME yield for different catalyst particle sizes, no effect of varying the linear gas velocity, and no effect of manipulating reactant diffusion coefficient. Packed bed microstructured reactors hence provide an isobaric and isothermal environment free from transport limitations for the direct DME synthesis, in the kinetic regime as well as at equilibrium conversion.