The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Satha Aphornratana - One of the best experts on this subject based on the ideXlab platform.
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cfd simulation on the effect of primary nozzle geometries for a steam ejector in refrigeration cycle
International Journal of Thermal Sciences, 2013Co-Authors: Natthawut Ruangtrakoon, Satha Aphornratana, Tongchana Thongtip, Thanarath SriveerakulAbstract:Abstract In this study, the CFD technique was employed to investigate the effect of the primary nozzle geometries on the performance of an ejector used in the steam jet refrigeration cycle. In all cases, only one fixed-geometry Mixing Chamber together with eight different primary nozzles was investigated numerically using the commercial CFD package, FLUENT 6.3. The effects on the primary fluid pressure, mass flow rate and Mach number were observed and analyzed. The Mach number contour lines were used to explain the Mixing process occurring inside the ejector. It was found that shock's position of the mixed fluid and the expansion angle of the primary fluid jet stream within the Mixing Chamber played a very important role in the ejector performance.
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cfd simulation on the effect of primary nozzle geometries for a steam ejector in refrigeration cycle
International Journal of Thermal Sciences, 2013Co-Authors: Natthawu Ruangtrakoo, Satha Aphornratana, Tongchana Thongtip, Thanarath SriveerakulAbstract:Abstract In this study, the CFD technique was employed to investigate the effect of the primary nozzle geometries on the performance of an ejector used in the steam jet refrigeration cycle. In all cases, only one fixed-geometry Mixing Chamber together with eight different primary nozzles was investigated numerically using the commercial CFD package, FLUENT 6.3. The effects on the primary fluid pressure, mass flow rate and Mach number were observed and analyzed. The Mach number contour lines were used to explain the Mixing process occurring inside the ejector. It was found that shock's position of the mixed fluid and the expansion angle of the primary fluid jet stream within the Mixing Chamber played a very important role in the ejector performance.
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theoretical study of a steam ejector refrigerator
International Energy Journal, 2007Co-Authors: Satha AphornratanaAbstract:This paper provides a theoretical analysis of a seam-ejector. An ejector model is developed based on one-dimensional ideal gas theory which was first introduced by Keenan. This theory is modified to include losses associated with the primary nozzle, Mixing Chamber, and diffuser. This ejector model is then used to analyse thermodynamic performance of a steam ejector refrigeration cycle over a range of operating temperatures. The theoretical results are compared with the experimental results obtained from the literatures.
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experimental investigation of an ejector refrigerator effect of Mixing Chamber geometry on system performance
International Journal of Energy Research, 2001Co-Authors: Satha Aphornratana, Supachart Chungpaibulpatana, Pongsid SrikhirinAbstract:This paper describes an experimental study of an ejector refrigeration cycle using R11 as the working fluid. The system was tested with boiler temperature from 100 to 110°C, the condenser temperature from 35 to 41°C, and the evaporator temperature up to 12°C. Two different Mixing Chambers with throat diameter of 8 mm were used. Choking of the fluid was always found in the first Mixing Chamber, but not in the second one. The system was more flexible to operate when there was no choking in the Mixing Chamber. A cooling temperature as low as −5°C could be obtained with COP between 0.1 and 0.25 and cooling capacity between 500 and 1700 W. Copyright © 2001 John Wiley & Sons, Ltd.
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a small capacity steam ejector refrigerator experimental investigation of a system using ejector with movable primary nozzle
International Journal of Refrigeration-revue Internationale Du Froid, 1997Co-Authors: Satha Aphornratana, Ian W. EamesAbstract:Abstract This paper describes an experimental study of a steam-ejector refrigerator using an ejector with a primary nozzle that could be moved axially within the Mixing Chamber section. The effects on coefficient of performance and cooling capacity produced by adjusting the position of the nozzle were studied. The experimental rig and method are described and results are presented which clearly show the benefit of using such a primary nozzle.
Yanxia Li - One of the best experts on this subject based on the ideXlab platform.
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numerical study for the influences of primary steam nozzle distance and Mixing Chamber throat diameter on steam ejector performance
International Journal of Thermal Sciences, 2018Co-Authors: Weina Fu, Hongqiang Wu, Yanxia Li, Yongzhi TangAbstract:Abstract The geometry and operation parameters have important influences on the performance of steam ejectors. An axisymmetric two-dimensional mathematical model for transonic compressible flow inside a steam ejector has been established in this paper to investigate the flow characteristics inside steam ejectors aiming at optimizing primary steam nozzle exit section distance and Mixing Chamber throat diameter simultaneously. The results show that there are an optimum value for the primary steam nozzle distance ratio and an optimum diameter ratio of Mixing Chamber throat to primary nozzle throat at which the steam ejector acquires its best entrainment performance under the given design conditions. With the optimized primary steam nozzle distance, the optimization of the diameter ratio of the Mixing Chamber throat to primary nozzle throat is significant. In our case, the improvement of the entrainment ratio is as large as 25%. Deviation from its optimized value may result in a serious degeneration in the ejector performance. Therefore, to ensure the steam ejector performance, the primary steam nozzle distance should be designed at its optimum value and the diameter ratio of the Mixing Chamber throat to primary nozzle throat be within a narrow vicinity of its optimum value.
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numerical investigation of the influences of Mixing Chamber geometries on steam ejector performance
Desalination, 2014Co-Authors: Hongqiang Wu, Yanxia LiAbstract:Abstract In this study, computational fluid dynamics (CFD) method is employed to investigate the effects of the Mixing Chamber geometries on the performance of steam ejectors used for multi-effect distillation systems. The internal flow characteristics of the steam ejector and the effects of the length and convergence angle of the Mixing Chamber were obtained. It is found that there is an optimum range of the Mixing Chamber length at which the ejector will acquire its largest entrainment ratio and the Mixing Chamber also has an optimum convergence angle at which the steam ejector performance is the best.
Hongqiang Wu - One of the best experts on this subject based on the ideXlab platform.
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numerical study for the influences of primary steam nozzle distance and Mixing Chamber throat diameter on steam ejector performance
International Journal of Thermal Sciences, 2018Co-Authors: Weina Fu, Hongqiang Wu, Yanxia Li, Yongzhi TangAbstract:Abstract The geometry and operation parameters have important influences on the performance of steam ejectors. An axisymmetric two-dimensional mathematical model for transonic compressible flow inside a steam ejector has been established in this paper to investigate the flow characteristics inside steam ejectors aiming at optimizing primary steam nozzle exit section distance and Mixing Chamber throat diameter simultaneously. The results show that there are an optimum value for the primary steam nozzle distance ratio and an optimum diameter ratio of Mixing Chamber throat to primary nozzle throat at which the steam ejector acquires its best entrainment performance under the given design conditions. With the optimized primary steam nozzle distance, the optimization of the diameter ratio of the Mixing Chamber throat to primary nozzle throat is significant. In our case, the improvement of the entrainment ratio is as large as 25%. Deviation from its optimized value may result in a serious degeneration in the ejector performance. Therefore, to ensure the steam ejector performance, the primary steam nozzle distance should be designed at its optimum value and the diameter ratio of the Mixing Chamber throat to primary nozzle throat be within a narrow vicinity of its optimum value.
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numerical investigation of the influences of Mixing Chamber geometries on steam ejector performance
Desalination, 2014Co-Authors: Hongqiang Wu, Yanxia LiAbstract:Abstract In this study, computational fluid dynamics (CFD) method is employed to investigate the effects of the Mixing Chamber geometries on the performance of steam ejectors used for multi-effect distillation systems. The internal flow characteristics of the steam ejector and the effects of the length and convergence angle of the Mixing Chamber were obtained. It is found that there is an optimum range of the Mixing Chamber length at which the ejector will acquire its largest entrainment ratio and the Mixing Chamber also has an optimum convergence angle at which the steam ejector performance is the best.
Eduardo Lincheta - One of the best experts on this subject based on the ideXlab platform.
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analysis and prediction of the spray produced by an internal Mixing Chamber twin fluid nozzle
Fuel Processing Technology, 2014Co-Authors: Jorge Barroso, Antonio Lozano, Felix Barreras, Eduardo LinchetaAbstract:Abstract Internal Mixing Chamber twin-fluid nozzles can advantageously replace traditional Y type nozzles to atomize high viscosity fluids. This is the case of power plants consuming heavy crude oils, where the use of this type of nozzles allows to obtain the smallest possible droplets with reduced gas flow rates. This work, based on previous experiments and new additional results, analyzes the flow in a specific twin-fluid nozzle of our own design and finally proposes some correlations to describe the flow conditions inside the Mixing Chamber, and subsequently, the characteristics of the final spray, represented by its Sauter mean diameter (SMD). These correlations include all the relevant variables, and the influence of each of them is discussed for different values of the inlet variables. Particular attention is focused on the situation in which the gas entrance to the Mixing Chamber is choked. The analysis and procedures here described could be easily applied to any twin-fluid nozzle with an internal Mixing Chamber.
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design optimization of twin fluid atomizers with an internal Mixing Chamber for heavy fuel oils
Fuel Processing Technology, 2009Co-Authors: German Ferreira, Antonio Lozano, Felix Barreras, Juan Antonio Garcia, Eduardo LinchetaAbstract:The present work is devoted to determine the magnitude of the main parameters that yield the optimum results for twin-fluid nozzles with an internal Mixing Chamber. The focus is placed on the study of the interaction of both air and liquid flows at the internal Chamber and its effects on the resulting spray. To this end, some experiments have been performed for different air central channel diameters and liquid ports, as well as for several experimental conditions (air and liquid mass flow rates), in order to understand the influence of the flow conditions at the Mixing Chamber on the size of the droplets produced. It has been demonstrated that under certain experimental conditions the atomizing fluid discharged to the internal Chamber is choked. The sonic condition is achieved for different air and liquid mass flow rates as a function of the air central channel diameter. It has also been obtained that to achieve the best results with moderate atomizing fluid flow rates, it is convenient to operate in choked conditions. This is an important result that will help in the optimum design of this type of nozzles.
Daliong Liang - One of the best experts on this subject based on the ideXlab platform.
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numerical investigation on the influence of Mixing Chamber length on steam ejector performance
Applied Thermal Engineering, 2020Co-Authors: Jingming Dong, Qiuyu Hu, Mengqi Yu, Daliong LiangAbstract:Abstract A steam ejector can effectively utilize waste heat resources, which is widely used in the fields of air conditioning, refrigeration, and seawater desalination. The structure of the steam ejector’s Mixing Chamber has a critical influence on its performance. In this paper, the effects of the Mixing Chamber length on the steam ejector performance under different Mach numbers at the nozzle exit, constant area section length, and diffuser length are studied using three-dimensional (3D) numerical simulations. The numerical simulation results show that the entrainment ratio and critical back pressure of the steam ejector rise first and then decrease with the increasing of the Mixing Chamber length under different Mach numbers, constant area section lengths and diffuser lengths. The steam ejector can achieve a better performance with the Mixing Chamber length in the range of 40–80 mm, when the nozzle throat diameter is 2.5 mm under a typical working condition of steam ejector refrigeration.