International Scientific Journal


The mid-high temperature heat pump provides hot water at a relatively high temperature using some industrial waste heat as its source. Now, the main refrigerants in this application are CFC114, HCFC123, and HCFC142b, etc., which are scheduled to be phased out due to their high ozone depletion potential and global warmth potential. Some studies have been conducted to find an eco-friendly alternative. In this paper, the natural non-azeotropic mixtures R744/R600a and R744/R600 are analyzed as alternatives. The performance of the heat pump system using new mixture is discussed and compared with those with CFC114, HCFC123, and HCFC142b. Under the given operating conditions, the maximum heating COP should occur at the mass fractions of 18/82 for R744/R600a and 10/90 for R744/R600. Both of their COP are higher than those with the refrigerants of CFC114, HCFC123, and HCFC142b. The COP and volumetric heating capacity of the system with R744/R600a are superior to those with R744/R600.
PAPER REVISED: 2014-03-06
PAPER ACCEPTED: 2014-07-13
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THERMAL SCIENCE YEAR 2014, VOLUME 18, ISSUE Issue 5, PAGES [1655 - 1659]
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© 2023 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence