A CFD-based investigation of the energy performance of two-phase R744 ejectors to recover the expansion work in refrigeration systems: An irreversibility analysis

Banasiak, Krzysztof; Palacz, Michał; Hafner, Armin; Buliński, Zbigniew; Smołka, Jacek; Nowak, Andrzej J.; Fic, A.

doi:10.1016/j.ijrefrig.2013.12.002

Cited by 82 publications

(34 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Of particular importance is the dissipative effect of the shock trains as it produces a compression and a shift from supersonic to subsonic conditions. There is considerable research concerning experimental [46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65] and numerical [66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81] studies of the flow phenomena inside an ejector. Even further detailed knowledge and modeling of these phenomena should allow for better component design.…”

Section: Supersonic Ejectormentioning

confidence: 99%

Ejector refrigeration: A comprehensive review

Besagni

Mereu

Inzoli

2016

Renewable and Sustainable Energy Reviews

404

View full text Add to dashboard Cite

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.

show abstract

Section: Supersonic Ejectormentioning

confidence: 99%

Ejector refrigeration: A comprehensive review

Besagni

Mereu

Inzoli

2016

Renewable and Sustainable Energy Reviews

404

View full text Add to dashboard Cite

show abstract

“…Most recent investigations have been concentrated on transcritical R744 ejector-expansion refrigeration cycles (EECs) because of the large improvement potential owing to the high throttling loss [1][2][3][4][5][6][7][8][9][10][11]. Subcritical EECs have received much less attention because these cycles offer relatively lower improvement potential through the ejector action.…”

Section: Introductionmentioning

confidence: 99%

Energetic and Exergetic Analysis of an Ejector-Expansion Refrigeration Cycle Using the Working Fluid R32

Zhang

Tong

Chang

et al. 2015

Entropy

View full text Add to dashboard Cite

Abstract:The performance characteristics of an ejector-expansion refrigeration cycle (EEC) using R32 have been investigated in comparison with that using R134a. The coefficient of performance (COP), the exergy destruction, the exergy efficiency and the suction nozzle pressure drop (SNPD) are discussed. The results show that the application of an ejector instead of a throttle valve in R32 cycle decreases the cycle's total exergy destruction by 8.84%-15.84% in comparison with the basic cycle (BC). The R32 EEC provides 5.22%-13.77% COP improvement and 5.13%-13.83% exergy efficiency improvement respectively over the BC for the given ranges of evaporating and condensing temperatures. There exists an optimum suction nozzle pressure drop (SNPD) which gives a maximum system COP and volumetric cooling capacity (VCC) under a specified condition. The value of the optimum SNPD mainly depends on the efficiencies of the ejector components, but is virtually independent of evaporating temperature and condensing temperature. In addition, the improvement of the component efficiency, especially the efficiencies of diffusion nozzle and the motive nozzle, can enhance the EEC performance.

show abstract

“…D  can be used to pinpoint the losses in energy quality across a specific process. This is readily done using the exergy destruction index ξ defined by Banasiak et al [21]: where the subscripts i and ejector represent the exergy destruction rate between the entrance and the i-section and for the total ejector respectively. In this analysis, the following dead state was assumed: T o = 300 K and P o = 1 atm.…”

Section: Exergy Analysismentioning

confidence: 99%

“…Even if all models provide similar results in terms of global performance, they pointed out that the results differed significantly regarding the local flow features (sonic line, shock position). Recently, Banasiak et al [21] were the first to use a CFD model to perform an exergy balance across the ejector, showing that the mixing and shock expansion processes are the most important contributors to the overall energy losses. This paper is the second part of a numerical investigation based on the supersonic ejector recently designed by Garcia et al [2] and working with R134a.…”

mentioning

confidence: 99%