Análise termodinâmica de um condensador evaporativo para melhoria da eficiência de um sistema de refrigeração

Abstract

The industrial sector has one of the largest energy consumptions in Brazil, mainly in the refrigeration systems, where there is a considerable use of thermal energy, which influences the increase in the environmental impact. If the system does not work effectively, the energy required to fulfill the cooling objective will be much greater. One of the most significant components in this process is the condenser, responsible for the thermal exchange in order to prepare the refrigerant fluid to cool the internal environments of the refrigerator. In view of this, the objective of this work is to analyze the thermodynamics of the evaporative ammonia condenser that makes up the refrigeration system of a refrigerator located in Alto Uruguai in Rio Grande do Sul. local study of the refrigeration system, identifying the main problems that could possibly affect the thermal exchange efficiency of the evaporative condenser, such as scale and corrosion in the tubes of the ammonia coil. Through the psychrometric mathematical model, an analysis of the heat transfer in the condensation process was carried out, its efficiency was evaluated, and from the CoolPack software, alternatives to change properties in search of greater efficiency were simulated. In this way, it was possible to perceive the negative effect of incrustations on the global heat transfer coefficient, and starting from the study of its behavior and the heat transfer rate as a function of the most significant variables in the heat exchange process, it was suggested proposals for the condenser to operate more efficiently. These were basically related to changes in air flow, coil surface area and ammonia condensing temperature, which, according to the simulation, made it possible to obtain a better performance coefficient for the refrigeration cycle.