Performance analysis of a centrifugal compressor in a vapor compression refrigeration cycle with an energy-based approach

Authors

1 Faculty of Mechanical Engineerig, Shahrood Unoversity of Technology

2 Faculty of Mechanical Engineering, Shahrood University of Technology

Abstract

Despite the advantages of centrifugal chillers, such as high capacity, high energy efficiency, and stable performance, these systems have been less studied. Therefore, this research investigates the performance of centrifugal chillers under various conditions. Considering the sensitivity of centrifugal compressors to the mass flow rate, this study examines not only the thermodynamic aspects of the chiller cycle but also the operation of the centrifugal compressor. Thermodynamic and numerical modeling were conducted using the EES and CFX software, respectively.The results from the EES modeling showed that under identical mass flow rates and pressure ratios, the coefficient of performance (COP) of the cycle with the R134a refrigerant in a two-stage configuration was 8% higher than that of a single-stage configuration, while for the R744 refrigerant, the COP increased by 23%. Additionally, the examination of intermediate pressure in two-stage cycles revealed that the highest COP under the same conditions occurs when the intermediate pressure is 1.7 times the evaporator pressure.The analysis of different refrigerants indicated that R134a had the highest COP, while R744 exhibited the lowest COP. The effect of cycle mass flow rate on compressor performance was numerically investigated; the results demonstrated that increasing or decreasing the chiller cooling capacity by 50% brings the compressor performance closer to the surge and choke points. Furthermore, numerical analysis examined the Mach number in the impeller for different mass flow rates.

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References

[1] Teresa Sani , Fiorella Prada , Giulia Radi,(2024), “ Ocean warming and acidification detrimentally affect coral tissue regeneration at a Mediterranean CO2 vent”, Science of The Total Environment Volume 906, January 2024, 167789.
[2] Chang Zhen,(2022), “ Centrifugal Chiller vs Screw Chiller (Chiller Selection Guide)”, aircondlounge, 26 March 2024.
[3] gesonchiller, “ Advantages and Disadvantages of Screw Type Chiller and Centrifugal Chiller”, 2010-2021 GESON REFRIGERATION EQUIPMENT CO.
[4]  Junnan Song ,  Guangbin Liu,(2022), “ Simulation on performance and regulation strategy of centrifugal refrigeration compressor with gas bearings in water chiller”, Applied Thermal Engineering Volume 236, Part B, 5 January 2024, 121650.
[5] Kuo‐ShuHung,Wei‐ChungHsiao,(2022), “ 150USRT Class R-513A Refrigerant Two-Stage Centrifugal Compressor Design Point and Separation Point Flow Field Simulation Analysis”, January 2023Processes 11(1):253.
[6]  Zhiping Zhang, Hongye Qiu,(2022), “ Development of Ultra-High-Efficiency Medium-Capacity Chillers with Two-Stage Compression and Interstage Vapor Injection Technologies”, December 2022Energies 15(24):9562.
[7]  F.W. Yu, K.T. Chan,(2008), “ Improved energy performance of air cooled centrifugal chillers with variable chilled water flow”, Energy Conversion and Management 49 (2008) 1595–1611.
[8] SELAHATTIN GOKTUN,(1995), “ AN OVERVIEW OF CHLORINE-FREE REFRIGERANTS FOR CENTRIFUGAL CHILLERS ”, Energy Vol. 20, No. 9, pp. 937-940, 1995.
[9] Mahdi Deymi, Mehdi Farahnak,(2019), “ Energy Saving and Environmental Impact of Optimizing the Number of Condenser Fans in Centrifugal Chillers under Partial Load Operation ”, Int. J. Refrigeration (2019).
[10] Weihua Lyu , Zhichao Wang,(2022), “ Energy efficiency and economic analysis of utilizing magnetic bearing chillers for the cooling of data centers”, J. Building Engineering Volume 48, 1 May 2022, 103920.
[11] David F , Juliana ,(2023), “ Performance prediction of a centrifugal compressor for a cogeneration microturbine”, Int. J. Thermofluids 17 100272.
[12] Andrea Giuffre , Piero Colonna,(2022), “ The Effect of Size and Working Fluid on the Multi-Objective Design of High-Speed Centrifugal Compressors”, Int. J. Refrigeration 143 (2022) 43–56.
[13] V.V. Neverov, Y.V. Kozhukhov(2017), “ Optimization of a centrifugal compressor impeller using CFD: The choice of simulation model parameters”, IOP Conf. Ser.: Mater. Sci. Eng. 232.
 
[14] Pekka Ro¨ytta ,Teemu Turunen-Saaresti,(2009), “ Optimising the refrigeration cycle with a two-stage centrifugal compressor and a flash intercooler”, int. J. refrigeration 32 (2009) 1366–1375.
[15] LG company catalog,” 2015 LG HVAC Solution”, 2015 LG Electronics. Printed in Korea. May. 2015 (Ver. 201505).
Journal of Solid and Fluid Mechanics
Volume 14, Issue 6
May and June 2025
Pages 1-18

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