THERMODYNAMIC ANALYSIS OF A RESIDENTIAL AIR CONDITIONING OPERATING WITH ODP FREE AND LOW GWP REFRIGERANTS

Abstract

Throughout the evolution of air conditioning, the fluids commonly used have also undergone through changes. Firstly, the concern was chosing a refrigerant that allows the proper operation of the equipment. In the last forty years, the focus became environmental problems caused by refrigerants when released into the atmosphere. The search for an eco-friendly refrigerant that can result in air conditioning applications with satisfactory thermodynamic efficiency is an actual and developing field. The present work performs a thermodynamic analysis of a residential air conditioning operating with alternative refrigerants with ODP free and low GWP (less than 3). Computational modeling is developed in Python, focused on the thermodynamic analysis of the condenser and evaporator of the selected equipment, allowing a comparison between some promising fluids. The methodology developed allows selecting the best fluid to be used either in retrofitting old equipment to a new refrigerant or in developing a completely new refrigeration system. The performance and cooling capacity of the system working with ammonia (R717), isobutane (R600a), propane (R290), R1234yf, R1234ze(E), R22 and R134a for different operation conditions are studied. The results indicate that ammonia presents the best performance among the selected refrigerants for the conditions assumed here, although not suitable for residential applications due to its toxicity. Moreover, R290 and R1234yf showed to be thermodynamically suitable refrigerants to domestic air conditioning equipment.