Analysis of Aqueous Lithium Bromide Absorption Refrigeration Systems

2021 ◽  
pp. 1-18
Author(s):  
Dongchuan You ◽  
Hameed Metghalchi
Keyword(s):  
Lithium Bromide ◽  
Double Effect ◽  
Environmental Safety ◽  
Coefficient Of Performance ◽  
Low Grade ◽  
Absorption Refrigeration ◽  
Solution Energy ◽  
Exit Temperature ◽  
Single Effect ◽  
Aqueous Lithium Bromide

Abstract Aqueous lithium bromide absorption refrigeration systems have been studied in recent years and their advantages like environmental safety and utilization of low-grade energy have been proved. Research on improving their performance has been increasing lately. In this paper, single effect and parallel flow double-effect aqueous lithium bromide absorption refrigeration systems have been studied. Mass, energy, entropy and exergy balances have been used to model the absorption refrigeration systems. Parametric studies have been done to investigate effects of cooling load, evaporator exit temperature, condenser exit temperature, generator vapor exit temperature, absorber exit temperature, solution energy exchanger effectiveness on the performance of the system. The analyses show coefficient of performance and exergetic efficiency of double-effect absorption refrigeration is higher than those of a single-effect refrigeration. The effect of other parameters on performance of both single and double-effect systems have been described in detail in the article.

A theoretical and experimental study of a novel recompression absorption refrigeration cycle

2001 ◽  
Vol 215 (1) ◽  
pp. 75-87 ◽  
Author(s):  
I. W. Eames ◽  
S Wu
Keyword(s):  
Experimental Study ◽  
Theoretical Study ◽  
Lithium Bromide ◽  
Coefficient Of Performance ◽  
Refrigeration Cycle ◽  
Absorption Refrigeration ◽  
Corrosion Rates ◽  
Steam Ejector ◽  
Single Effect ◽  
Absorption Cycle

This paper describes a novel vapour absorption refrigeration cycle which uses a steam ejector to enhance the concentration process of the cycle. The paper provides a complete description of the cycle and presents the results of a theoretical study before going on to describe and evaluate the outcomes of an experimental programme. The results of this investigation showed that with the addition of a steam ejector as described the coefficient of performance (COP) of the single-effect lithium bromide absorption cycle can be increased from about 0.7 to at least 1.0 without any increase in corrosion rates often associated with high temperature vapour generators used in conventional machines of this type.

Exergy analysis: Parametric study on lithium bromide—water absorption refrigeration systems

2007 ◽  
Vol 221 (11) ◽  
pp. 1345-1351 ◽  
Author(s):  
K Sedighi ◽  
M Farhadi ◽  
M Liaghi
Keyword(s):  
Exergy Analysis ◽  
Water Solution ◽  
Lithium Bromide ◽  
Cooling Water ◽  
Coefficient Of Performance ◽  
Absorption Refrigeration ◽  
Exergetic Efficiency ◽  
Evaporator Temperature ◽  
Cooling Water Temperature ◽  
Single Effect

In the current study, an exergy analysis of a single-effect absorption refrigeration cycle using lithium bromide-water solution is carried out. The cycle has been analysed by considering the mass and energy conservation based on the first and second laws of thermodynamics. This analysis provides a detailed information on the effect of different parameters on the system performance. The coefficient of performance (COP), exergetic efficiency (ECOP), and exergy destruction are determined. The results show that a reduction in cooling water temperature caused an improvement in the COP and ECOP. Increasing the evaporator temperature has also improved the COP, but it caused a reduction in the ECOP of the system. Also it can be seen that the parameters' variation at the solution side has a more significant effect on cycle performances.

THERMODYNAMIC ANALYSIS OF SINGLE- AND DOUBLE-EFFECT ABSORPTION REFRIGERATION SYSTEMS FOR COOLING ETHANOL FERMENTATION PROCESS

2014 ◽  
Vol 22 (04) ◽  
pp. 1450020 ◽  
Author(s):  
HUGO VALENÇA DE ARAÚJO ◽  
JOSÉ VICENTE HALLAK D'ANGELO
Keyword(s):  
Thermodynamic Analysis ◽  
Fermentation Process ◽  
Alcoholic Fermentation ◽  
Double Effect ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Second Law ◽  
Base Case ◽  
Absorption Refrigeration ◽  
Single Effect

Alcoholic fermentation is one of the most important stages in industrial ethanol production process, involving a biochemical and exothermic reaction. Sometimes cooling towers are not capable of supplying a cold utility with a temperature low enough to maintain the fermentative medium temperature in a desirable range. Absorption Refrigeration Systems (ARS) appears to be a good alternative to obtain the necessary refrigeration for the fermentation process. The aim of the present paper was to carry out a thermodynamic analysis of ARS, evaluating their performance through the First and Second Laws of Thermodynamics. ARS with different configurations were studied (single-effect and double-effect with series, parallel and reverse parallel flows), all of them operating with water/lithium bromide mixture as working pair, under different operating conditions in order to satisfy the cooling load required by an industrial alcoholic fermentation process. Another objective of this paper was to investigate the risk of LiBr crystallization, which can result in scaling formation, with the aid of the solid–liquid phase equilibrium curve of H 2 O / LiBr mixture. Among the double-effect configurations studied, it was observed that series flow presents the more significant crystallization risk, which represents a limit to improve its First and Second Law performances. It was verified that the Second Law performance for the single-and double-effect ARS analyzed are similar, but their First Law performance are considerably different. This is due to the amount and quality of the heat consumed in the first effect generators of these systems. For a base case studied, First Law performance measured by coefficient of performance (COP) of double-effect ARS is 72% greater than the one for single-effect, while for Second Law performance, measured by exergetic efficiency, an increase of 5% was observed.

Configuration optimization of series flow double-effect water-lithium bromide absorption refrigeration systems by cost minimization

2018 ◽  
Vol 158 ◽  
pp. 359-372 ◽  
Author(s):  
Sergio F. Mussati ◽  
Stefano Cignitti ◽  
Seyed Soheil Mansouri ◽  
Krist V. Gernaey ◽  
Tatiana Morosuk ◽  
...  
Keyword(s):  
Cost Minimization ◽  
Lithium Bromide ◽  
Double Effect ◽  
Absorption Refrigeration ◽  
Configuration Optimization

Simulation of a Double-Effect Solar Absorption System for Traditional House in Yemen

2014 ◽  
Vol 695 ◽  
pp. 797-800 ◽  
Author(s):  
Osamah Zaid Ahmed ◽  
Farid Nasir Ani
Keyword(s):  
High Pressure ◽  
Lithium Bromide ◽  
Double Effect ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Absorption System ◽  
Alternative Source ◽  
Solar Absorption ◽  
Lithium Bromide Solution ◽  
Pressure Generator

During the last few years, the awareness of the pollution and the global warming has dramatically increased which encourage the researchers around the world to find an alternative source of energy. One of the most efficient sources of energy is the solar energy especially for cooling and heating applications. This paper, described the simulation of a double-effect solar absorption system in Yemen using water lithium bromide solution as a working fluid. The system will be applied to a typical traditional house in Yemen. The performance of the system will be analyzed based on different high pressure generator temperature for the yearly solar radiation data. At higher pressure generator temperature, the results show a higher coefficient of performance of the system. This simulation also estimate high pressure generator heat transfer required to operate the system. As a result, the size of solar collector area and the cost of such system will be calculated.

Use of low grade heat sources in combined ejector–double effect absorption refrigeration systems

2012 ◽  
Vol 226 (5) ◽  
pp. 607-622 ◽  
Author(s):  
Leili Garousi Farshi ◽  
SM Seyed Mahmoudi ◽  
Marc A Rosen ◽  
Morteza Yari
Keyword(s):  
Double Effect ◽  
Low Grade ◽  
Heat Sources ◽  
Absorption Refrigeration ◽  
Low Grade Heat

Combined Desalination and Refrigeration Systems Driven by Low-Grade Heat

2008 ◽  
Author(s):  
Yongqing Wang ◽  
Noam Lior
Keyword(s):  
Heat Pump ◽  
Gas Turbines ◽  
Air Conditioning ◽  
Saturation Pressure ◽  
Coefficient Of Performance ◽  
Saturated Steam ◽  
Low Grade ◽  
Absorption Refrigeration ◽  
Wide Range ◽  
Low Grade Heat

There is often a need for both water desalination and cooling (refrigeration/air-conditioning). The cooling can be used to significantly raise system efficiency by compressor inlet cooling in a dual-purpose power-generation and desalination system using gas turbines, or simply to supply refrigeration or air conditioning beside fresh water. Motivated by the good synergetic potential of energy/exergy utilization through the combination of the LiBr-H2O refrigeration unit, LiBr-H2O heat pump, and low-temperature multi-effect evaporation desalter, two combined refrigeration and water systems, ARHP-MEE (Absorption Refrigeration Heat Pump and Multi-Effect Evaporation desalter) system and ARHP-AHP-MEE (Absorption Refrigeration Heat Pump + Absorption Heat Pump + Multi-Effect Evaporation desalter) system, driven by low-grade heat were configured, modeled and analyzed in detail in the paper. Typically, driving steam with saturation pressure of 0.15–0.35 MPa and correspondingly saturation temperature of 111.4–138.9°C is applicable to run the systems. The main results are: (1) the combined systems have good synergy, with an energy saving rate of 42% in a case study of ARHP-MEE; (2) the refrigeration-heat cogenerated ARHP subsystem is the main reason for the synergy, where the coefficient of performance is around 1.6 and exergy efficiency above 60% when driven by 0.25 MPa saturated steam; (3) at the cost of a more complex configuration, the ARHP-AHP-MEE system has the ability of varying its outputs in very wide range, offering good flexibility on design and operation; (4) the ARHP-MEE system is predicted to have good economics, and its outputs can be varied in a wide range but not independently because their ratio remains almost constant. A parametric analysis was also performed for the ARHP-MEE, further improving the understanding of the system performance.

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