An analysis of the performances of a vapour compression plant working both as a water chiller and a heat pump using R22 and R417A

The aim of this paper is to study the performances of a vapour compression experimental plant working both as a water chiller and as a heat pump, using as refrigerant fluids R22 and its substitute R417A (R125/R134a/R.600 46.6/50/3.4% in mass). This kind of system is used in industrial processing or air conditioning plants where a supply of refrigerated and heated water is required. As for the R22 substitution there is not a unanimous solution. So in this paper the non-azeotropic mixture R417A is experimentally tested as a substitute of the R22. The R417A is a non-ozone depleting long-term replacement for the R22, and can be also adopted in existing and new direct expansion systems using the traditional R22 lubricants. This substitute provides a simple solution to the legislation since it has an ozone depletion potential equal to zero and, besides, it does not require a change of lubricant type, equipment redesign or significant modifications. The experimental plant has allowed to verify the best performances of R22 in comparison with R417A in terms of coefficient of performance, exergetic efficiency, exergy destroyed in the components and of more important variables influencing the vapour compression plant performance. (C) 2003 Elsevier Ltd. All rights reserved.