Exergy Investigation of R410A as a ‘Drop In’ Refrigerant in a Water-Cooled Mechanical Vapor Compression Cycle

The urge to replace hydrofluorocarbons which possess high global warming potentials has taken center stage in the air conditioning industry due to both international and local policies such as the Kigali Amendment and Japan’s revised Fluorinated Gas law. This has prompted the exploration of novel refrigerants as well as their mixtures to create high performance environmentally friendly alternatives. These refrigerants can be integrated into existing systems as ‘drop in’ refrigerants, which provide a simpler and low cost substitution process to replace environmentally harmful refrigerants such as R410a. R410a is currently a widely used refrigerant in air conditioning systems, but is to be phased out of use under the Kigali Amendment by the late 2040s. Thus to compare the suitability of replacing this refrigerant with environmentally friendly ‘drop in’ alternatives, a preliminary baseline investigation on a mechanical vapor compression chiller with R410a is conducted via performance and exergy indicators. The testing procedure utilized Air Conditioning, Heating and Refrigeration Standard 551/591 which revealed an optimum charge amount of 0.70 kg with a peak performance near 88% of full capacity. The heat exchanger overall heat transfer coefficients showed varying trends, whilst the exergy destruction was as expected highest for the compressor.