Thermodynamic analysis of vapour compression refrigeration system with performance enhancing devices for alternative refrigerants

Abstract

In present time, refrigeration and air conditioning have become an essential newlinepart of life. The synthetic refrigerants used in these refrigeration systems cause ozone newlinelayer depletion, global warming and increase energy consumption. This has inspired the newlineresearchers to develop the novel refrigeration systems with high energy efficiency and newlinealso use natural environment-friendly refrigerants (Hydrocarbons, NH3, CO2, and N2O newlineetc.). Many methods have been reported in the literature to improve the performance of newlinethe vapour compression system with the use of performance enhancing devices as newlinesubcooler, expander, vortex tube and ejector etc. The literature review shows that newlinerefrigerant CO2 and performance enhancing devices as subcooler, expander and ejector newlinehave already gained their acceptance in refrigeration systems but use of refrigerant N2O newlinein vortex tube integrated refrigeration systems is still in its infant stage . newlineAccordingly, in the present research, thermodynamic analysis (First and newlinesecond law analysis) of modified single stage and two stage transcritical vapour newlinecompression systems integrated with vortex tube have been performed using N2O. Two newlinelayouts based on Maurer model (TSVT-1 i.e. Transcritical System with Vortex Tube-1) newlineand Keller model (TSVT-2 i.e. Transcritical System with Vortex Tube-2) have been newlineused for the single stage vortex tube integrated refrigeration systems. These two layouts newline(TSVT-1, TSVT-2) have been compared with the conventional single stage newlineTranscritical System with Expansion Valve (TSEV). The detailed thermodynamic newlineanalysis ofTSVT-1, TSVT-2 and TSEV shows that evaporator and gas cooler exit newlinetemperatures have significant effect on the maximum COP, exergy losses, and newlineexergetic efficiency of these systems. Application of the vortex tube in place of newlineexpansion valve in single stage transcritical system is favorable for higher COP, higher newlineexergetic efficiency and lower optimum gas cooler pressure at considered conditions. newlineThe COP and exergetic efficiency of the TSVT-1 are on average 10% to 12% h