Modelagem do desempenho de um sistema de refrigeração por absorção misto

Abstract

This work has as its main goal the analysis of a mixed absorption refrigeration system that used lithium bromide (LiBr) and water (H2O) as working fluids. Mass balances, solution concentration and energy were specified for the equipment. Thermodynamic modeling was performed using the Engineering Equation Solver (EES) software. As its heat source, the system possesses exhaust gases and hot water from an internal combustion engine and, for cooling, cooling water is used. The analysis has as main indicator the Coefficient of Performance (COP) of the refrigeration system, with a value of 0.9884 achieved for normal conditions. By changing the hot water and exhaust gas mass flow, a metric called the heat ratio was developed for analysis, variations in this ratio shows a change in the COP. By varying the ratio from 0.16:1 to 1:0,2, COP values between 2.34 and 0.45 were found. One of the conclusions was that the COP is inversely proportional to the heat ratio, indicator developed from the heat input in the generators. The COP tended to be larger when that ratio decreased. This work was compared with an article by Wang and Wu (2015).