Oil Mass Flow Rate Research Articles

Study on Distribution Performance of a New Oil-Air Distributor in Oil-Air Lubrication System

The fluid domain model of a new oil-air distributor in oil-air lubrication system is built and the phase distribution of oil and air two-phase flow on distribution interface is simulated based on the CFD model in Fluent, the mass flow rate of oil and air are collected from three different cross sections when the structures of oil-air guidance slot are designed as a plane, sphere and cone shape respectively, then the influence of oil-air guidance slot structure on the performance of distributor is analyzed in the oil-air lubrication system in this paper. The results show that the spherical surface and conical surface of oil-air guidance slot can improve the uniformity and stability of the oil and air two-phase flow distribution, promote the flow pattern to form a continuous annular oil film. Among these three structures of oil-air guidance slot, we also find that the distribution performance of conical surface is the best.

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.

Analysis of Shiraz Solar Thermal Power Plant Response Time

Shiraz pilot solar thermal power plant is the first Iranian solar power plant constructed near the city of Shiraz, Iran. The main purpose of constructing this pilot plant was to acquire the technology of developing parabolic trough solar thermal power plants for future energy production from solar energy. This plant consists of 48 parabolic trough collectors; each one has 25m long and 3.4 m wide. The plant consists of two cycles, oil heat absorbing cycle and steam production cycle. The plant performance and transition period to reach steady state condition or damping some disturbances as well as oil cycle heating and steam generation rate depends on several factors such as oil cycle response time. Response time is a parameter that can be used for efficient control of solar power plant. To study response time, field experimental measurements have been made during the years 2009 to 2010 based on the standard procedure and plant simulation. The experiments include: plant start up, evaluation of oil temperature increase in the field of collectors, solar radiation measurements, temperature and pressure changes in the heat exchangers, weather temperature changes and wind speed and the effect of above changes on the system response time are determined. Two modeling methods (based on the recommended standards) of finding response time are employed. Results show that response time of the oil cycle varies from 150 seconds to 400 seconds by measurements, while by modeling simulation it is about 400-500 seconds. Response time is strongly depends on the environmental conditions such as oil temperture, wind and ambient temperature and specially the oil mass flow rate.

HYDROCYCLONE APPLICATIONS IN PRODUCED WATER: A STEADY-STATE NUMERICAL ANALYSIS

Hydrocyclones are devices used to treat produced water in the petroleum industry. These gadgets are employed especially at offshore fields, due to restrictions of charge and space. Several factors may affect the performance of the oil/water separation by hydrocyclones. Among these factors are the geometry and processing capacity of the hydrocyclones, oil droplet size, density difference between the phases, pressure drops, and temperature fluctuation. This paper aims to analyze the effects of inlet fluid mixture temperature and oil droplet size on hydrocyclone performance in separating dispersed heavy oil from continuous streams of water. The experiment used a commercial package, ANSYS CFX 11. Numerical results clearly indicate that superficial velocity and oil mass flow rate in the overflow have a positive relationship with oil droplet size and temperature. The pressure drop decreased from 155.857 to 141.966kPa and the separation efficiency changed from 58.97 to 60.11% when the inlet temperature increased from 20 to 100°C using a 40μm oil droplet diameter.

In situ oil flow measurements in fired engine compared to one-dimensional lube circuit simulation

This article describes the measurement methodology employed to determine oil mass flowrate through internal combustion (IC) engine oil circuits. Comparisons with one-dimensional (1D) simulations of oil circuits are shown and potential applications to the development of optimized oil circuits are outlined. Lubricant mass flowrates at different lube circuit locations are not well known. For optimized engine friction development, oil mass flowrates have been measured along the engine lube circuit in motored and fired engine to better understand the real oil feeding conditions of the main mechanical parts. These measurements show that not only oil mass flowrates, but also oil distributions in the lube circuit evolve with the engine speed and load. This has to be taken into account for engine mechanical part design. The constant temperature anemometry method, used in this study, proved to be an appropriate way to better investigate engine lube circuit behaviour. A 1D fluid-flow model of the engine lube circuit has been made and results were compared to measurement data. Simulation results were found to be consistent with measurement data.

CO2용 실외열교환기의 오일 영향에 따른 성능변화에 대한 실험적 연구

In order to investigate the effects of PAG oil concentration on heat transfer performance and pressure drop during gas cooling process of <TEX>$CO_2$</TEX>, the experiments on fin-tube heat exchanger of <TEX>$CO_2$</TEX> heat pump were performed. The experimental apparatus consists of a gas cooler, a heater, a chiller, a mass flow meter, a pump and measurement system. Experiments were conducted in various experimental conditions, which were inlet temperature(<TEX>$110^{\circ}C$</TEX>), mass flow rates (50, 55, 60, 65, 70 g/s) and PAG oil concentration(0 to 2.6 wt%). Heat transfer rate decreased with the increase of the oil concentration and the decrease of inlet pressure. And pressure drop increased with the increase of the oil concentration and mass flow rate of refrigerant. The COP reduction by deterioration of gas cooler performance with oil concentration was analyzed. When inlet pressure of gas cooler is 100 bar, the COP reduction was estimated by 6% under 1 wt% of oil concentration.

Thermodynamic optimization of fluidized catalytic cracking (FCC) units

In this paper, a thermodynamic optimization procedure for FCC riser units has been developed. The formulation uses a 2D fluid flow and kinetic model to provide the necessary information for the optimization process. The thermodynamic analysis is based on the unit entropy generation minimization, i.e., the minimization of the destroyed exergy in the system. This kind of analysis has been widely used in power generation plants, with large benefits. It was verified that for any given catalyst mass flow rate, there exists an optimum value for the catalyst to oil mass flow rate ratio, COR, for maximum mass flow rate production of gasoline, or any other desired product. Next, the objective function (net exergy production rate) was maximized through the minimization of the destroyed exergy inside the FCC unit. The optimization was conducted with respect to the catalyst to oil ratio (COR). It is important to stress that all optima are sharp, i.e., for example with H/D=50, the variation of E∼net is greater than 50%, calculated from (E∼net,max-E∼net,min)/E∼net,max for 5<COR<25. Based on the lack of second law analysis related works for FCC plants in the technical literature and in view of the potential gains suggested by the results, the authors believe that thermodynamic optimization could bring new insight in the quest for better FCC plants. Therefore, a low computational time tool is made available for simulation, control, design and optimization of FCC units.

대형 상용차용 수동변속기내 윤활시스템의 유동특성에 관한 연구

This study has conducted numerical analysis for lubrication system of transmission for commercial vehicle. The lubrication oil system in transmission can be applied to a large scale commercial vehicle which is over 15tons. The flow rate of lubricating oil has been obtained for each of branch port from the lubrication pipe. The results from numerical simulation are mainly suggested for the mass flow rate of lubrication oil in the rotating main shaft of transmission system. It has been found that the mass flow rate from oil hole increased with an rotating rate of main shaft. The flow characteristic from oil hole has been presented for the lubricating system in the manual transmission.

Control of an oil-heated, fractal-like branching microchannel desorber

A PID controller was designed to improve the performance of an oil-heated, fractal-like branching microchannel desorber for use in an ammonia-absorption refrigeration system. System identification techniques were employed to develop single-input, single-output reduced order models relating the oil mass flow rate and the rectified circulation ratio ( f * ) for four different operating conditions. PID controllers were designed for each of these reduced order system models and the closed-loop response of the desorber was simulated for various operating conditions and controller combinations. The preliminary controller designs were refined by examining controlled desorber performance in an experimental flow loop. The resulting PID controller yielded a closed-loop response with a faster rise time and lower overshoot than the simulated controllers. The tuned controller regulated the desired rectified circulation ratio under the operating conditions studied, controlling both the amount and concentration of the ammonia refrigerant generated. Prescribed variations in f * were tracked by the controlled system with a settling time of approximately 10 min. Controlled performance was robust to external disturbances in the strong solution flow rate and the oil temperature, regulating f * about the desired value with a settling time similar to that observed during the tracking tests.

Comparative trials and an empirical model to assess throughput indices in olive oil extraction by decanter centrifuge

Interesting performance indices for a decanter centrifuge used in oil extraction from olive paste were found through an empirical black box approach to oil extraction using a decanter centrifuge validated with experimental data. The performance indices identified were: oil recovery efficiency, the separation coefficient and husk water content. Two decanter centrifuges were compared and based on our experimental data we identified an empirical model of the decanter centrifuge suitable for use both as a comparison between two or more machines and as automatic control of the machine in order to adapt it to the olive paste. The average RMSEP% when forecasting the mass flow rate of the outgoing oil was 4.4% for decanter A and 4.3% for decanter B. When using the empirical model to measure oil recovery efficiency against the mass flow rate of the olive paste, on varying the paste dilution, there is an “indifference point” where the oil recovery efficiency is invariant with respect to the dilution coefficient of the olive paste. Both the oil recovery efficiency and the mass flow rate of the olive paste at this point are two fundamental performance factors that allow two or more decanter centrifuges to be compared.

Analysis of oil pumping in a reciprocating compressor

The immediate provision of lubricant oil to the radial and thrust bearings and to the piston–cylinder gap in reciprocating refrigeration compressors is a crucial reliability issue following compressor start-up. The aim of this paper is to present a hydrodynamic analysis of the lubricant oil pumping system of a reciprocating compressor using computational fluid dynamics (CFD). In the present system, oil is pumped from the sump through a reed-type centrifugal pump located at the bottom end of the shaft. The oil flows initially as a climbing film on the internal surface of the shaft before it is directed to the external surface where it flows along a helix channel carved on the shaft wall. The model was implemented on the commercial package Fluent using the volume of fluid (VOF) method to resolve the free-surface oil flow. Parameters regarding the oil behavior during start-up, such as the time required to reach steady-state operation and the associated oil mass flow rate are explored in the manuscript.

Deacidification and recovery of distillates in the physical refining of edible oils

AbstractA pilot plant‐scale continuous deodorization installation was developed to simultaneously test several technological changes in the classical deodorization process: use of nitrogen as stripping gas, heating of the gas above the liquid oil, and use of shell‐and‐tube condensers for the recovery of distillates. Deacidification trials were first carried out on mixtures of commercial refined sunflower oil and high‐oleic distillates, and subsequently on bleached olive and sunflower oils. The performance of usual working conditions was analyzed: nitrogen mass flow rate, oil temperature and oil mass flow rate. Marked differences were not observed in the results of the final acidity, compositions of free fatty acids and sterols in the deacidified oil. However, the use of shell‐and‐tube condensers makes it possible to recover liquid distillates in better conditions than in the classical process for their further concentration, while at the same time reducing process pollution.

Optimization of Deacidification of Mixtures of Sunflower Oil and Oleic Acid in a Continuous Process

AbstractMixtures of refined sunflower seed oil and oleic acid were deacidified using nitrogen as stripping gas in a pilot‐plant scale continuous deodorizer. To optimize the process, two different levels were tested for the classical operating parameters of oil temperature, nitrogen flow rates, oil mass flow rates and initial free fatty acid contents. In addition, two heating procedures were tested, including one using separate electrical heating of the oil and gas distillates to maintain the same temperature in both parts of the deodorizer, and another in which only the oil was heated and controlled, resulting in a temperature difference between the oil and the gas distillates. The statistical technique of blocking with paired comparisons was used to analyze the final free fatty acid content, rate of free fatty acid loss with respect to the processed oil flow rate, free fatty acid content in the distillates recovered by condensation, and efficiency. The results showed that the oil temperature and maintaining the same temperature in the oil and the gas distillates produced the most relevant effects, having a positive effect on most of the responses.

Performance evaluation of a helix tube solar collector system

In this paper we evaluated the performance of a helix tube solar collector. This helix tube collector increases the absorbed radiation of diffuse and ground reflection. The inner and outer diameters of the helix tube are 8 and 12 mm, respectively. The helix tube was designed as a copper tube which is coated with a nanocarbon composite. A cylindrical glass, length 1.2 m, outer diameter 1.397 × 10−1 m and thickness 6.4 × 10−3 m, was used as a cover. The performance of the collector was in Phitsanulok province, Thailand, which is located at latitude 16.783°N with an average wind velocity of 3 m s−1. Solar absorbance was 0.94 and the IR emission of nanocarbon was 0.15. The heat transfer fluid was Paratherm MG™ oil at 32°C and the oil mass flow rate was 9.5 kg h−1. These were used to evaluate the performance of the collector. The performance of the helix tube collector and the temperature difference of oil (inlet and outlet) were 50.32% and 47.43°C, respectively. Copyright © 2007 John Wiley & Sons, Ltd.

Investigation of oil-air two-phase mass flow rate measurement using Venturi and void fraction sensor

Oil-air two-phase flow measurement was investigated with a Venturi and void fraction meters in this work. This paper proposes a new flow rate measurement correlation in which the effect of the velocity ratio between gas and liquid was considered. With the pressure drop across the Venturi and the void fraction that was measured by electrical capacitance tomography apparatus, both mixture flow rate and oil flow rate could be obtained by the correlation. Experiments included bubble- slug-, wave and annular flow with the void fraction ranging from 15% to 83%, the oil flow rate ranging from 0.97 kg/s to 1.78 kg/s, the gas flow rate ranging up to 0.018 kg/s and quality ranging nearly up to 2.0%. The root-mean-square errors of mixture mass flow rate and that of oil mass flow rate were less than 5%. Furthermore, coefficients of the correlation were modified based on flow regimes, with the results showing reduced root-mean-square errors.

Cooling of oil injected screw compressors by oil atomisation

This paper addresses the effect of oil atomisation in an oil-injected screw compressor. A test rig was built to assess the performance of different types of atomisers. Atomisers varying from fine atomisation to coarse atomisation were tested. Experiments on the test rig show that lowering the oil droplet diameter results in a considerably higher heat transfer. Growing oil flow rate, also gives a better cooling effectiveness. In parallel with the experiments, a thermodynamic model is developed by which the compression process can be calculated for every degree of revolution of the male-rotor. This way the influence of cooling oil temperature, cooling oil mass flow rate and injection point can be analysed. Having a better heat transfer effectiveness does not give a considerable gain in specific work. Lowering oil temperature gives better results, while changing the oil flow rate only gives small gains. Furthermore it is shown that cooling oil coming from the bearings has a negative influence on the performance. This paper shows that trying to reach isothermal compression through oil atomisation is not possible. The importance of the cooling effectiveness in the thermodynamic process is too small to have a significant influence.

Study of Hybrid Lubrication at the Tooth Contact of a Wormgear Transmission: Part 2—Results and Discussion

Part 2 begins by describing the numerical solution procedures of the hybrid lubrication problem. Results of the computation are then presented that include the detailed pressure and temperature distribution in the oil film, the required supply pressure for maintaining the prescribed minimum oil film thickness, the fluid friction acting on the worm coil surface, the mass flow rate of supply oil, and the power loss associated with the restrictor flow. The feasibility of the hydrostatically lubricated wormgear transmission is discussed in light of these results.

Production of high-quality gasoline by catalytic cracking over rare-earth metal exchanged Y-type zeolites of heavy oil from waste plastics

The effects of reaction conditions and properties of the catalysts used on the product yields and quality of the gasoline fraction from the catalytic cracking of heavy oil obtained from waste plastics over rare-earth metal exchanged Y-type (REY) zeolites were examined. Gasoline with high contents of isoparaffins and low contents of n-paraffins and aromatics is desired in order to increase the research octane number and to achieve complete burning. A large amount of gasoline with these favorable components was obtained by the catalytic cracking of heavy oil over a REY zeolite catalyst under the condition of a time factor (ratio of the mass of the catalyst to the mass flow rate of the feed oil) of 0.75-1 kg-cat.kg-oil −1 .h, a reaction temperature of 673 K, and a catalyst of small crystal size that has a moderate amount of sites of strong acid strength