Title: Comparative energetic and exergetic studies of vapour compression and vapour absorption refrigeration cycles

Authors: Suman Chattopadhyay; Dibyendu Roy; Sudip Ghosh

Addresses: Department of Mechanical Engineering, Indian Institute of Engineering Science and Technology, Shibpur, P.O. – B. Garden, Howrah-711103, W.B., India ' Department of Mechanical Engineering, Indian Institute of Engineering Science and Technology, Shibpur, P.O. – B. Garden, Howrah-711103, W.B., India ' Department of Mechanical Engineering, Indian Institute of Engineering Science and Technology, Shibpur, P.O. – B. Garden, Howrah-711103, W.B., India

Abstract: In this study, two types of refrigeration cycles, a vapour compression refrigeration (VCR) cycle and a vapour absorption refrigeration (VAR) cycle, have been modelled and analysed. Both the cycles have same operating cooling loads and both operate between the same temperature limits. R134a has been considered as refrigerant for the VCR cycle whereas LiBr-H₂O has been considered as the working fluid for the VAR cycle. Energetic and exergetic performances have been evaluated for both the cycles and compared. The effects of condenser temperature, evaporator temperature and environmental dead state temperature on the performances of these cycles are also discussed. Energy analysis reveals that the coefficient of performance (COP) of the VCR cycle is considerably higher than that of VAR cycle. However, exergy analysis reveals that the exergetic coefficient of performance (ECOP) of the VAR cycle is very close to that of VCR cycle. For environmental dead state temperature beyond 35°C, the exergetic performance of VAR cycle is better than that of VCR cycle. The maximum exergy destruction occurs at the evaporator for the VCR cycle but for VAR cycle, the maximum exergy destruction occurs at the generator.

Keywords: coefficient of performance; COP; energy; exergy; refrigeration; vapour compression refrigeration; VCR; vapour absorption refrigeration; VAR.

DOI: 10.1504/IJRET.2017.088965

International Journal of Renewable Energy Technology, 2017 Vol.8 No.3/4, pp.222 - 238

Received: 05 Jan 2017
Accepted: 12 May 2017
Published online: 03 Jan 2018 *

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