An experimental and computational study of the flow pattern in a refrigerant ejector. Validation of turbulence models and real-gas effects

Valle, J. García del; Sierra-Pallares, José; Carrascal, P. García; Ruíz, Francisco

doi:10.1016/j.applthermaleng.2015.06.064

Cited by 40 publications

(10 citation statements)

References 30 publications

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“…Further work [203,209,234] under different conditions and fluids found SST k-ω to best represent their case studies.…”

Section: Turbulence Modelingmentioning

confidence: 98%

“…With the new developments in computers and data-processing technologies, recent studies have become more comprehensive on mixing chamber geometry, local flow structure, shock wave formation and irreversibility [138,[201][202][203][204][205][206]. A number of these studies were devoted to turbulence model evaluation and selection with respect to specific requirements in ejector operation based on comparison with local/global data and generating valuable information on local flow structure [75,203,[207][208][209]. Other works generated fields of isobars and Mach contours along the mixing chamber (typically in Figure 19).…”

Section: Numerical Ejector Modelingmentioning

confidence: 99%

“…For this reason, a simplified form of theses equations, the Reynolds-averaged Navier-Stokes (RANS) formulation is almost always solved instead. For cases where time is taken into account URANS is then used [203,218].…”

Section: Equations Of Conservationmentioning

confidence: 99%

“…Rusly et al [72] simulated on-design operation of ejectors based on Huang et al [70] results for R141b with remarkable success (less than 3.5% discrepancy on ω). Recent comparisons with various refrigerants and conditions were performed by many authors [15,78,88,92,158,203,230,238] with fairly good predictions for ω and outlet pressure in the respective ranges of (5-24%) and (7-11%).…”

Section: Global Validationmentioning

confidence: 99%

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Current Advances in Ejector Modeling, Experimentation and Applications for Refrigeration and Heat Pumps. Part 1: Single-Phase Ejectors

et al. 2019

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Ejectors used in refrigeration systems as entrainment and compression components or expanders, alone or in combination with other equipment devices, have gained renewed interest from the scientific community as a means of low temperature heat recovery and more efficient energy use. This paper summarizes the main findings and trends, in the area of heat-driven ejectors and ejector-based machines, using low boiling point working fluids, which were reported in the literature for a number of promising applications. An overall view of such systems is provided by discussing the ejector physics principles, as well as a review of the main developments in ejectors over the last few years. Recent achievements on thermally activated ejectors for single-phase compressible fluids are the main focus in this part of the review. Aspects related to their design, operation, theoretical and experimental approaches employed, analysis of the complex interacting phenomena taking place within the device, and performance are highlighted. Conventional and improved ejector refrigeration cycles are discussed. Some cycles of interest employing ejectors alone or boosted combinations are presented and their potential applications are indicated.

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“…Further work [203,209,234] under different conditions and fluids found SST k-ω to best represent their case studies.…”

Section: Turbulence Modelingmentioning

confidence: 98%

Section: Numerical Ejector Modelingmentioning

confidence: 99%

Section: Equations Of Conservationmentioning

confidence: 99%

Section: Global Validationmentioning

confidence: 99%

See 2 more Smart Citations

Current Advances in Ejector Modeling, Experimentation and Applications for Refrigeration and Heat Pumps. Part 1: Single-Phase Ejectors

et al. 2019

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“…Results indicated that the stagnation degree of superheating of inflows does not affect the mass ratio for values higher than 10℃. Also during a computational study (del Valle et al, 2015) they evaluated the effects of real gas model and different turbulence models on flow pattern inside the ejector. In seeking for alternatives refrigerants for the widely used refrigerant R134a, other studies were carried out (Lawrence and Elbel, 2014;Li et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Numerical Investigation of a Refrigeration Ejector: Effects of Environment-Friendly Refrigerants and Geometry of the Ejector Mixing Chamber

Moghaddam

Shafaee

Riazi

2019

European Journal of Sustainable Development Research

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In refrigeration cycles, ejectors are employed as thermo-compressors. To improve their performance, the operational conditions and geometrical parameters could be evaluated. In this numerical study firstly, the effects of refrigerants R1234ze(E) and R1234yf as replacements for R134a are investigated. Results showed that using R1234yf, the entrainment ratio and the coefficient of performance (COP) increase 10% and 1.7% respectively. When R1234ze is used, the entrainment ratio and the COP decrease 3.4% and 7% respectively compared with R134a. For the boiler operating temperature, an optimum value was found at which the entrainment ratio and the COP are maximum. However, the entrainment ratio and the COP enhance by increment of the evaporator temperature. In the second part, the effect of the mixing chamber convergence angle is studied. Results illuminated that by increment of the converging angle up to a certain value, the entrainment ratio and the COP enhance, but beyond the optimum angle, a reverse behavior is observed. However, by increment of the convergence angle, the critical back temperature declines continually. By increase of the convergence angle, the flow field inside the ejector is affected, and weaker shock waves are established at the end of mixing chamber that influence the critical back temperature.

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Ejector CFD Modeling

Grazzini

Milazzo

Mazzelli

2018

Ejectors for Efficient Refrigeration

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An experimental and computational study of the flow pattern in a refrigerant ejector. Validation of turbulence models and real-gas effects

Cited by 40 publications

References 30 publications

Current Advances in Ejector Modeling, Experimentation and Applications for Refrigeration and Heat Pumps. Part 1: Single-Phase Ejectors

Current Advances in Ejector Modeling, Experimentation and Applications for Refrigeration and Heat Pumps. Part 1: Single-Phase Ejectors

Numerical Investigation of a Refrigeration Ejector: Effects of Environment-Friendly Refrigerants and Geometry of the Ejector Mixing Chamber

Ejector CFD Modeling

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