Retrofit of an internal heat exchanger in a R404A refrigeration system using R452A: Experimental assessment on the energy efficiency and CO2 emissions

The experimental investigation on using R452A in refrigeration system operating with R404A is conducted in this study. A tube-in tube internal heat exchanger is also utilized to retrofit the system for improving its energy performance. The evaporation temperatures are adjusted as − 3, 0 and + 3 °C while the condenser temperatures are studied for the cases of 25, 40 and 55 °C. The coefficient of performance, discharge temperature as well as volumetric efficiency of the compressor and total equivalent warming impact values are determined and compared in the investigation for the covered cases. Generally, the coefficient of performance of R404A is detected to be greater for condenser temperature of 25 °C while that of R452A is better for 40 and 55 °C cases. Hence, R452A may be suggested to use in R404A refrigeration systems for hot climate regions. Additionally, the energy performance of the system further enhanced for both tested refrigerants when the system is retrofitted with the internal heat exchanger. The environmental warming impact amounts of the refrigerants are also considered in the study. According to the computations, R452A has been determined to be more environmental-friendly compared to R404A. Hence, R452A can be suggested to be a suitable candidate as an alternative to R404A in a refrigeration system in the medium term considering its better energetic performance as well as lower environmental impact. Additionally, utilizing a tube-in-tube type internal heat exchanger should provide further both improvement on energy efficiency of the system and reduced carbon dioxide emissions to the environment.