Theoretical analysis of a novel liquid-vapor separation condensation ejector refrigeration cycle with zeotropic mixtures

The trans-critical CO2 refrigeration cycle involving a regenerative process is analyzed in this paper. The thermodynamic performance of the cycles with regeneration and without regeneration has been compared. The optimal circumstance for the regenerative process set in the trans-critical CO2 cycle is given. The impact of the regeneration on the performance of the system under difference operating conditions is also discussed in this article.

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Theoretical analysis of vapour refrigeration cycle with hybrid refrigerant of different types and mixing ratios

University of Thi-Qar Journal for Engineering Sciences ◽

10.31663/tqujes.11.2.389(2021) ◽

2021 ◽

Author(s):

Mushtaq Ismael Hasan ◽

Jasim Mohsin Chitheer

Keyword(s):

Theoretical Analysis ◽

Refrigeration Cycle ◽

Mixing Ratios ◽

Different Types

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Investigation of the Liquid–Vapor Separator Efficiency on the Performance of the Ejector Used as an Expansion Device in the Vapor-Compression Refrigeration Cycle

Journal of Energy Resources Technology ◽

10.1115/1.4044354 ◽

2019 ◽

Vol 142 (1) ◽

Author(s):

Ayşe Uğurcan Atmaca ◽

Aytunç Erek ◽

Orhan Ekren

Keyword(s):

Performance Improvement ◽

Separation Efficiency ◽

Area Ratio ◽

Refrigeration Cycle ◽

Entrainment Ratio ◽

Operation Conditions ◽

Vapor Compression Refrigeration Cycle ◽

The Difference ◽

Ejector Cycle ◽

Liquid Vapor

Abstract Ejector expansion refrigeration cycle with reference to the constant pressure mixing theory is investigated to display the effects of the liquid–vapor separator efficiency on the performance, entrainment ratio, and area ratio at various operation conditions. Reversible ejector assumption is used for the highest theoretical performance limit, whereas efficiency of the liquid–vapor separator and all ejector components is added to the model to calculate more realistic performance improvement potentials. R1234yf and R1234ze(E) having low global warming potential values are used in the analyses. Zero-dimensional thermodynamic models are constructed applying the conservation equations between the inlets and outlets of the refrigeration cycle and ejector components. Percentage performance decrease is higher when the mixing section and the separator efficiency is added to the model at higher condenser temperatures compared with the lower evaporator temperatures according to the investigated operation ranges. Vapor and liquid separation efficiency affects not only the performance but also the design of the ejector although it is an external component since it has influence on the area ratio and entrainment ratio. Finally, the difference between the percentage performance improvement of the reversible ejector cycle and the realistic ejector cycle including the separator and ejector components efficiencies is as high as 35% at the highest investigated condenser temperature for R1234yf.

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Theoretical Analysis of Effects of Solution Heat Exchanger on the Performance of Mixed Absorption Refrigeration Cycle

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.170-173.2521 ◽

2012 ◽

Vol 170-173 ◽

pp. 2521-2524

Author(s):

Wen Li ◽

Jun Hua Wan ◽

Jing Liu ◽

Zu Yi Zheng ◽

Wen Ming Xu

Keyword(s):

Heat Exchanger ◽

Theoretical Analysis ◽

Temperature Difference ◽

Heat Exchangers ◽

Water Flow Rate ◽

Cooling Water ◽

Solution Temperature ◽

Refrigeration Cycle ◽

Absorption Refrigeration ◽

Cooling Water Flow Rate

The model of solution heat exchangers of mixed absorption refrigeration cycle was developed. The effects of strong solution temperature difference between inlet and outlet of solution heat exchanger on the coefficient of performance (COP) and cooling water flow rate of mixed absorption refrigeration cycle were analyzed, at the same time, the effects of temperature difference on the unit heat exchange area of counter-flow and cross-flow solution heat exchangers were analyzed. The theoretical analysis results showed that there was an optimal value for the strong solution temperature difference, for the mixed absorption system, the optimal temperature difference was about 12°C, the corresponding COP was 11.2% higher and the cooling water flow rate was 7.8% less than that of system without heat exchanger.

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