Energy Evaluation of an Absorption Heat Transformer Operating with Water-Carrol Solution by Means of Mathematical Programming

Abstract

The objective of this work is an energy evaluation based on the coefficient of performance (COP) of an experimental absorption heat transformer (AHT) operating with Water–Carrol solution. The COP is a measure of the thermal efficiency of the system. An optimization tool was used, as it is mathematical programming. The mathematical model was obtained by means of mass and energy balances for each stage of thermodynamic cycle and global balances of AHT. Design parameters (i.e. effectiveness of the economizer), correlations of thermodynamic properties of water and Water-Carrol solution (i.e. specific enthalpy (H), equilibrium temperatures and concentrations) have been used. The optimal values of decision variables to maximize the COP (objective function) are determined using a mathematical programming formulation. The model was programmed in the General Algebraic Modelling System (GAMS) software. Energy performance curves were developed in order to show and establish the best behaviour of the COP in function of the decision variables.