A New Computational Tool for the Development of Advanced Exergy Analysis and LCA on Single Effect LiBr–H2O Solar Absorption Refrigeration System

José Cabrera César,Guillermo Valencia Ochoa,Rafael Ramírez Restrepo,Jean Caratt Ortiz,José R Nuñez Alvarez

doi:10.3390/lubricants9080076

José Cabrera César, Guillermo Valencia Ochoa + Show 3 more

Open Access

https://doi.org/10.3390/lubricants9080076

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Journal: Lubricants	Publication Date: Aug 5, 2021
Citations: 5	License type: CC BY 4.0

Affiliation: University of Atlántico, University of the Coast

Abstract

A single effect LiBr–H2O absorption refrigeration system coupled with a solar collector and a storage tank was studied to develop an assessment tool using the built-in App Designer in MATLAB®. The model is developed using balances of mass, energy, and species conservation in the components of the absorption cooling system, taking into account the effect of external streams through temperature and pressure drop. The whole system, coupled with the solar energy harvesting arrangement, is modeled for 24 h of operation with changes on an hourly basis based on ambient temperature, cooling system load demand, and hourly solar irradiation, which is measured and recorded by national weather institutes sources. Test through simulations and validation procedures are carried out with acknowledged scientific articles. These show 2.65% of maximum relative error on the energy analysis with respect to cited authors. The environmental conditions used in the study were evaluated in Barranquilla, Colombia, with datasets of the Institute of Hydrology, Meteorology and Environmental Studies (IDEAM), considering multiannual average hourly basis solar irradiation. This allowed the authors to obtain the behavior of the surface temperature of the water in the tank, COP, and exergy efficiency of the system. The simulations also stated the generator as the biggest source of irreversibility with around 45.53% of total exergy destruction in the inner cycle without considering the solar array, in which case the solar array would present the most exergy destruction.

Highlights

Most of the air conditioning systems used globally are based on vapor compression refrigeration systems (VCRs), a thermal cycle that is widely used in the refrigeration field
These systems are known as vapor absorption refrigeration systems (VARs), being the most common temperature operated system, and typically use water–ammonium or lithium bromide–water as the refrigerant pairs
A vapor absorption refrigeration (VAR) system is a thermodynamic cycle similar to the popular vapor compression refrigeration (VCR) system that consists of four main components: evaporator, condenser, valve, and compressor

Summary

Introduction

Most of the air conditioning systems used globally are based on vapor compression refrigeration systems (VCRs), a thermal cycle that is widely used in the refrigeration field. There are thermally driven air conditioning systems that can be powered by heat from industrial exhaust gases, energy from waste heat from processes, among others, which replace the compressor and electrical energy that drives it from the power grid. These systems are known as vapor absorption refrigeration systems (VARs), being the most common temperature operated system, and typically use water–ammonium or lithium bromide–water as the refrigerant pairs. Both types can be adapted for space conditioning and can be combined with waste heat, geothermal, cogeneration plants, among others [4,5]

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