Thermo‐economic optimization and comparison study of LiBr‐H ₂ O and LiCl‐H ₂ O working pair in absorption cooling systems based on genetic algorithm

Abstract

Summary The major intention of this study is to reduce the total expenditure of a vapor absorption cooling system (VACS) by developing an optimization model with an alternative working pair LiCl‐H2O and compares it with the traditional LiBr‐H2O system. Considering the cooling capacity of 50 kW, two working pairs were to compare parametrically at various operating conditions. The model comprises of three parts, viz. a thermodynamic model for the estimation of coefficient of performance, exergetic efficiency, and availability destruction of system components; an economic model for computing expenditure flow rate and capital investing expenditure rate; and the minimization of the total expenditure using genetic algorithm. The parametric study suggests that a LiCl‐H2O system performs better from both thermodynamic and expenditure‐effective aspects under all working conditions involved in this study. Especially, a low generator temperature produces a noticeable difference. The present global optimization technique assesses the optimal operating temperatures of generator, absorber, condenser, and evaporator. An optimal operating condition provides a system with a 1.20% of decrement in total expenditure rate and 5.39% of reduction in total capital investing expenditure rate using LiCl‐H2O solutions with respect to LiBr‐H2O solutions. Finally, results derived from this study may assist to designers to choose an alternative working fluid for enhancing the performance of VACS.