Efeito dos solventes acetona, etanol e suas soluções aquosas sobre o decaimento térmico em sistemas psicrométricos

Abstract

Humanity nowadays ends up using methods that are often polluting and require very high energy expenditure restlessly searching to cool the environment around them, such as refrigerators and air conditioning systems. Therefore, science has been looking for sustainable and low-cost alternatives for refrigeration, mainly in internal environments such as offices, living rooms and bedrooms. The main alternatives currently are evaporative refrigeration systems (psychrometric systems) that use thermal decay from the natural evaporation of water to cool air currents, as the system proposed by DIAS et al. (2020) which uses a cyclone separator as an evaporative cooler. However, only a few studies deal with these systems in terms of the natural evaporation of water in the presence of solvents or even other pure fluids. This work aimed to investigate the effect of the presence of solvents on the thermal decay of psychrometric systems, using acetone, ethanol and their mixture with water, investigating the possibility of using them in the Dias system, and evaluating their use in refrigeration. of domestic environments. The results obtained showed that pure alcohol and acetone generate a significant increase in thermal decay, which varies from 2.4°C to 24.5°C depending on the conditions and solvents. However, mixing these with water results in intermediate thermal decays, which strongly depend on the molar ratio. Furthermore, the use of these in cooling cyclones was analyzed via simulation for the cooling of a 14m² room, which resulted in final temperatures between 26.7°C and 5.6°C depending on the solution and conditions used. Despite of this, the theoretically calculated solvent usage makes the application of such systems for refrigeration of domestic environments unfeasible, unless a solvent recovery system is developed.