Numerical investigation of a two-phase CO2 ejector

Lucas, Christian; Rusche, Henrik; Schröeder, Andreas; Koehler, Juergen

doi:10.1016/j.ijrefrig.2014.03.003

Cited by 82 publications

(43 citation statements)

References 13 publications

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“…Moreover, droplet nucleation and the subsequent development of condensation result in an energy transfer that cannot be accurately simulated when assuming the steam to be a perfect gas. Therefore, recent computational fluid dynamics, CFD, simulations of steam ejector performance have incorporated droplet nucleation and condensation using the homogeneous model [92][93][94]. For the ejector shape, a re-design of the nozzle is required to account for the nucleation downstream of the throat to provide a sufficient distance for avoiding the presence of flow oscillations across the sonic section [91].…”

Section: Number Of Phasesmentioning

confidence: 99%

Ejector refrigeration: A comprehensive review

Besagni

Mereu

Inzoli

2016

Renewable and Sustainable Energy Reviews

407

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a b s t r a c tThe increasing need for thermal comfort has led to a rapid increase in the use of cooling systems and, consequently, electricity demand for air-conditioning systems in buildings. Heat-driven ejector refrigeration systems appear to be a promising alternative to the traditional compressor-based refrigeration technologies for energy consumption reduction. This paper presents a comprehensive literature review on ejector refrigeration systems and working fluids. It deeply analyzes ejector technology and behavior, refrigerant properties and their influence over ejector performance and all of the ejector refrigeration technologies, with a focus on past, present and future trends. The review is structured in four parts. In the first part, ejector technology is described. In the second part, a detailed description of the refrigerant properties and their influence over ejector performance is presented. In the third part, a review focused on the main jet refrigeration cycles is proposed, and the ejector refrigeration systems are reported and categorized. Finally, an overview over all ejector technologies, the relationship among the working fluids and the ejector performance, with a focus on past, present and future trends, is presented.

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Section: Number Of Phasesmentioning

confidence: 99%

Ejector refrigeration: A comprehensive review

Besagni

Mereu

Inzoli

2016

Renewable and Sustainable Energy Reviews

407

View full text Add to dashboard Cite

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“…Similarly, Lucas et al (2014) investigated CO 2 ejectors numerically. As in the work of Smolka et al (2013), thermodynamic and mechanical equilibria were assumed for the two-phase flow.…”

Section: Introductionmentioning

confidence: 99%

“…In that study, an energy equation was formulated in the same manner as in the model described previously. However, in the Lucas et al (2014) study, OpenFOAM solver was used instead of commercial software. The TEMO-media library was used to obtain the physical properties of the real fluid.…”

Section: Introductionmentioning

confidence: 99%

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Application range of the HEM approach for CO2 expansion inside two-phase ejectors for supermarket refrigeration systems

Palacz

Smołka

Fic

et al. 2015

International Journal of Refrigeration

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Application range of the HEM approach for CO 2 expansion inside two-phase ejectors for supermarket refrigeration systems, International Journal of Refrigeration (2015), http://dx.doi.org/ HighlightsThe accuracy of the HEM approach for the R744 expansion inside ejectors was assessed.The HEM accuracy decrease with the decreasing motive nozzle inlet temperature.The HEM guarantee accurate results for operating regimes close to the CO2 critical point. AbstractIn this study, the accuracy of the homogeneous equilibrium (HEM) applied to 3-D CFD-based simulations of CO 2 expansion inside two-phase ejectors is presented. The HEM approach previously reported in the literature were assessed by comparing the computed and measured mass flow rates that pass through an ejector motive nozzle. In addition, the HEM approach implemented using CFD was tested over a vast range of ejector operating regimes. To ensure that all of the computations were performed consistently, a validated CFD model combined within an in-house developed script was used. The comparison of the experimental and computational results showed that the HEM accuracy varied for the different sets of operating parameters. Accurate results were obtained for operating regimes near or above the CO 2 critical point. The model accuracy decreased with the decreasing temperature and decreasing distance to the saturation line.

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“…Varga et al (8) 은 CFD를 이용하여 노즐위치에 따른 이젝터의 성능을 확인하였다. 또한, Lucas et al (9) 은 CFD를 이용 하여 CO₂사이클에서의 이상 이젝터의 최적 설계 디자 인을 고찰하였다. Li and Groll …”

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Experimental Analysis on the Performance Characteristics of an Ejector according to Inlet Pressure and Nozzle Position

Lee¹,

Jeon²,

Kim³

et al. 2015

Korean Journal of Air-Conditioning and Refrigeration Engineerin

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In this study, the performance of an ejector in the refrigeration cycle was experimentally studied using R600a. The performance of the ejector is analyzed according to the inlet pressure and nozzle position. The increase in the primary nozzle pressure decreased the pressure difference across the ejector. In the low entrainment region, the increased suction flow pressure led to an increase in the pressure difference. In the high entrainment region, the pressure difference was inversely proportional to the suction pressure. The effects of nozzle position (Ln) were also analyzed and for Ln < 0, the decreased suction chamber volume led to a large pressure drop with the small increase in the suction mass flow rate. For Ln > 0, the increased Ln disturbed the primary nozzle flow and thus an increase in the primary nozzle flow increased the pressure lifting effect. In contrast, the increased suction mass flow rate decreased the pressure difference. When the nozzle outlet was located at the mixing part entrance (Ln = 0), the ejector showed the highest pressure lifting effect.

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Numerical investigation of a two-phase CO2 ejector

Cited by 82 publications

References 13 publications

Ejector refrigeration: A comprehensive review

Ejector refrigeration: A comprehensive review

Application range of the HEM approach for CO2 expansion inside two-phase ejectors for supermarket refrigeration systems

Experimental Analysis on the Performance Characteristics of an Ejector according to Inlet Pressure and Nozzle Position

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