International Scientific Journal


In this paper, an advanced exergetic study is carried out to improve the exergy efficiency and minimize the exergy losses of an absorption refrigerator. Two thermal processes based on rectification and distillation were proposed to meet this critical requirement. A numerical simulation model was established in the FORTRAN language, building on the analytical Gibbs free energy equations. This model was validated from a thermodynamic point of view by previously published results. Preliminary results showed that when the efficiency of the absorber and boiler is increased, the vapors produced by the boiler become enriched in ammonia, and the overall exergy efficiency increases, which reduces considerably the irreversibility of the components of the studied absorption system. A comparative study of the effect of these two thermal processes on the overall exergy efficiency and total exergy losses was evaluated simultaneously. The results show that the refrigerator with a distiller has a higher exergy efficiency (ηex = 24.37% at 86°C), and at the same time has a lower total exergy loss (Exl,tot = 457.45 kW) than the refrigerator with a rectifier (ηex = 22.34% at 85°C; Exl,tot = 532.37 kW). This study reveals that the distillation process can contribute more to the exergy improvement and exergy loss minimization of the studied absorption refrigerator than the rectification process.
PAPER REVISED: 2022-07-11
PAPER ACCEPTED: 2022-07-18
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THERMAL SCIENCE YEAR 2023, VOLUME 27, ISSUE Issue 2, PAGES [1597 - 1610]
  1. Nikbakhti, R., et al., Absorption Cooling Systems - Review of Various Techniques for Energy Performance Enhancement, Alexandria Engineering Journal, 59 (2020), 2, pp. 707-738
  2. He, Y., Chen, G., Equivalent Cycle and Optimization of Auto-Cascade Absorption Refrigeration Systems, Journal Therm. Sci., 29 (2020), 4, pp. 1053-1062
  3. Wen, T., et al., Review on the Fundamentals and Investigations of Falling Film Dehumidification/Absorption Refrigeration Based on CFD Technology, International Journal of Heat and Mass Transfer, 171 (2021), 121042
  4. Papadopoulos, A. I., et al., Systematic Assessment of Working Fluid Mixtures for Absorption Refrigeration Based on Techno-Economic, Environmental, Health and Safety Performance, Energy Conversion and Management, 223 (2020), 113262
  5. Yang, L., et al., Dynamic Characteristics of an Environment-Friendly Refrigerant: Ammonia-Water Based TiO2 Nanofluids, International Journal of Refrigeration, 82 (2017), Oct., pp. 366-380
  6. Malaine,S., et al., Enhancing Benefits by Rectification in the Absorption Refrigeration Systems, International Journal of Thermodynamics, 25 (2022), 1, pp. 29-37
  7. Trubyanov, M. M., et al., A Hybrid Batch Distillation/Membrane Process for High Purification - Part 1: Energy Efficiency and Separation Performance Study for Light Impurities Removal, Separation and Purification Technology, 241 (2020), 116678
  8. Blahušiak, M., et al., Quick Assessment of Binary Distillation Efficiency Using a Heat Engine Perspective, Energy, 116 (2016), Dec., pp. 20-31
  9. Magaril, E., Magaril, R., Effect of Pressure on the Rectification Sharpness in Rectifying Sections of Tray Distillation Columns in Oil and Gas Refining, Separation and Purification Technology, 223 (2019), Sept., pp. 49-54
  10. Fernandez-Seara, J., Sieres, J., The Importance of the Ammonia Purification Process in Ammonia-Water Absorption Systems, Energy Conversion and Management, 47 (2006), 13, pp. 1975-1987
  11. Fernandez-Seara, J., et al., Distillation Column Configurations in Ammonia-Water Absorption Refrigeration Systems, International Journal of Refrigeration, 26 (2003), 1, pp. 28-34
  12. Sieres, J., Fernandez-Seara, J., Evaluation of the Column Components Size on the Vapour Enrichment and System Performance in Small Power NH3-H2O Absorption Refrigeration Machines, International Journal of Refrigeration, 29 (2006), 4, pp. 579-588
  13. Adewusi, S. A., Zubair, S. M., Second Law Based Thermodynamic Analysis of Ammonia-Water Absorption Systems, Energy Conversion and Management, 45 (2004), 15-16, pp. 2355-2369
  14. Guzman, G., et al., Thermal Optimization of a Dual Pressure Goswami Cycle for Low Grade Thermal Sources, Entropy, 21 (2019), 7, 711
  15. Belman-Flores, M., et al., Energetic Analysis of a Diffusion-Absorption System: A Bubble Pump under Geometrical and Operational Conditions Effects, Applied Thermal Engineering, 71 (2014), 1, pp. 1-10
  16. Aman, J., et al., Bubble-Pump-Driven LiBr-H2O and LiCl-H2O Absorption Air-Conditioning Systems, Thermal Science and Engineering Progress, 6 (2018), June, pp. 316-322
  17. Ahachad, M., et al., Study of an Improved NH3-H2O Solar Absorption Refrigerating Machine in Rabat (Morocco), Solar Energy Materials and Solar Cells, 28 (1992), 1, pp. 71-79
  18. Dardouch, J., et al., Study of a Solar Absorption Refrigeration Machine in the Moroccan Climate, Materials Today: Proceedings, 13 (2019), Part 3, pp. 1197-1204
  19. Rosa, A. C., et al., Quantitative Risk Analysis Applied to Refrigeration's Industry Using Computational Modelling, Results in Engineering, 9 (2021), 100202
  20. Sencan, A., et al., Prediction of Liquid and Vapor Enthalpies of Ammonia-Water Mixture, Energy Sources - Part A: Recovery, Utilization, and Environmental Effects, 33 (2011), 15, pp. 1463-1473
  21. Taboas, F., et al., Flow Boiling Heat Transfer of Ammonia/Water Mixture in a Plate Heat Exchanger, International Journal of Refrigeration, 33 (2010), 4, pp. 695-705
  22. Alsarayreh, A. A., et al., Energy and Exergy Analyses of Adsorption Chiller at Various Recooling-Water and Dead-State Temperatures, Energies, 14 (2021), 8, 2172
  23. Alamdari, G. S., Simple Equations for Predicting Entropy of Ammonia-Water Mixture, IJE Transactions B: Applications, 20 (2007), 1, pp. 97-106
  24. Khaliq, A., et al., Energetic and Exergetic Analyses of a Solar Powered Combined Compression-Absorption Refrigeration System, International Journal of Exergy, 34 (2021), 4, pp. 448-474
  25. Okwose, C. F., et al., Performance Analysis of Compressor-Assisted Two-Stage Triple Effect Absorption Refrigeration Cycle for Power and Cooling, Energy Conversion and Management, 227 (2021), 113547
  26. Kherris, S., et al., Contribution Study of the Thermodynamics Properties of the Ammonia-Water Mixtures, Thermal Science, 17 (2013), 3, pp. 891-902
  27. Mejbri, K., Bellagi, A., Modelling of the Thermodynamic Properties of the Water-Ammonia Mixture by Three Different Approaches, International Journal of Refrigeration, 29 (2006), 2, pp. 211-218
  28. Ziegler, B., Trepp, C., Equation of State for Ammonia-Water Mixtures, International Journal of Refrigeration, 7 (1984), 2, pp. 101-106
  29. Mazouz, S., et al., System Modelling and Parameter Effects on Design and Performance of a New Refrigeration Machine, International Journal on Energy Conversion (IRECON), 2 (2004), 3
  30. Hasan, A., Dincer, I., An Ocean Thermal Energy Conversion Based System for District Cooling, Ammonia and Power Production, International Journal of Hydrogen Energy, 45 (2020), 32, pp. 15878-15887
  31. Bellos, E., et al., Yearly Investigation of a Solar-Driven Absorption Refrigeration System with Ammonia-Water Absorption Pair, Thermal Science and Engineering Progress, 23 (2021), 100885
  32. Chen, J., et al., A Sustainable Syngas Cryogenic Separation Process Combined with Ammonia Absorption Refrigeration pre-Cooling Cycle, Journal of Cleaner Production, 313 (2021), Sept., 127612
  33. Yilmaz, f., Energy, Exergy and Economic Analyses of a Novel Hybrid Ocean Thermal Energy Conversion System for Clean Power Production, Energy Conversion and Management, 196 (2019), Sept., pp. 557-566
  34. Kalla, S. K., Usmani, J. A., Performance Analysis of Vapour Compression Refrigeration System with R502 and its Substitutes, International Journal on Energy Conversion (IRECON), 1 (2013), 4
  35. Valles, M., et al., Solar-Driven Absorption Cycle for Space Heating and Cooling, Applied Thermal Engineering, 168 (2020), 114836
  36. Satyro, M. A., et al., Temperature Change from Isenthalpic Expansion of Aqueous Triethylene Glycol Mixtures for Natural Gas Dehydration, Fluid Phase Equilibria, 305 (2011), 1, pp. 62-67
  37. Fakheri, A., Heat Exchanger Efficiency, Journal of Heat Transfer, 129 (2007), 9, pp. 1268-1276
  38. Ebrahimi, A., et al., Novel Integrated Structure Using Solar Parabolic Dish Collectors for Liquid Nitrogen Production on Offshore Gas Platforms (Exergy and Economic Analysis), Sustainable Energy Technologies and Assessments, 7 (2020), 100606

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