Title: Investigation of the component exergy efficiencies of a two stage vapour compression cycle

Authors: Sertac Samed Seyitoglu; Ali Kilicarslan

Addresses: Department of Mechanical Engineering, Hitit University, Corum 19030, Turkey ' Department of Mechanical Engineering, Hitit University, Corum 19030, Turkey

Abstract: The exergy efficiencies of the components (compressor I and II, condenser, evaporator and flash tank) of a two stage vapour compression refrigeration cycle were analysed with respect to evaporator and condenser temperatures for various refrigerants such a R1234ze, R1234yf, R236fa, R227ea and R134a. In the analysis, a computer program was developed by means of engineering equation solver (EES). The exergy efficiencies of components such as the evaporator, condenser, flash tank and compressor I increased while the exergy efficiency of compressor II decreased for the refrigerants used in the cycle for the evaporator temperatures ranging between -30°C to 0°C. The exergy efficiencies of the components such as compressor I and II increased while the exergy efficiency of condenser decreased, and the exergy efficiency of the evaporator stayed almost constant for the refrigerants used in the cycle for the condenser temperatures ranging between 40°C and 55°C. For all refrigerants, the highest exergy efficiencies (around 0.99) were obtained in the flash tank of the cycle while the lowest ones (around 0.15) were obtained in the condenser.

Keywords: vapour compression refrigeration; two-stage; exergy efficiency; R1234ze; R1234yf; R236fa; R227ea; R134a.

DOI: 10.1504/IJEX.2018.093899

International Journal of Exergy, 2018 Vol.27 No.1, pp.43 - 61

Received: 11 Aug 2017
Accepted: 27 Feb 2018
Published online: 08 Aug 2018 *

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