Thermodynamic and Exergy Analysis of an Absorptıon Cooling System for Different Refrigerants

Yıl 2020, Cilt: 7 Sayı: 1, 93 - 103, 31.01.2020

Dilek Nur Özen , Kemal Çağrı Yağcıoğlu

https://doi.org/10.31202/ecjse.594641

Cited By: 1

Öz

In absorption cooling systems, the compression of the working fluid is
not made by the compressor but by a system consisting of absorbers, pumps and
generators. The fact that the compressor is not used for compression reduces
the power required for this process. In this case, absorption cooling systems
are very useful when used with renewable energy sources. In this study,
thermodynamic and exergy analysis of the system was performed to see the
effects of different refrigerant solutions on the performance of an absorption
cooling system. In the absorption cooling system for Lithium bromide-Water
(LiBr-H₂O), ammonia-water (NH₃-H₂O),
ammonia-lithium nitrate (NH₃-LiNO₃) and ammonia-sodium
thiocyanate (NH₃-NaSCN) fluid couples, the Coefficient of
Performance (COP) and Exergy Efficiency (%) of the system were examined for
each fluid pair by analyzing at different generator, evaporator and absorber
temperatures. Analysis results indicate that the LiBr-H₂O solution
pair showed better performance (higher COP and exergy efficiency) than the
other solution pairs (NH₃-H₂O, NH₃-LiNO₃,
NH₃-NaSCN).

Anahtar Kelimeler

Exergy, ammonia/NH3, LiBr/H2O, ammonia/NaSCN, absorption refrigeration system

Farklı Soğutucu Akışkanlar için Bir Absorbsiyonlu Soğutma Sisteminin Termodinamik ve Ekserji Analizi

Öz

Absorpsiyonlu soğutma sistemlerinde çalışma
akışkanının sıkıştırma işlemi kompresörle değil absorber, pompa ve generatörden
oluşan bir sistemle yapılmaktadır. Sıkıştırma işlemi için kompresör
kullanılmaması bu işlem için ihtiyaç duyulan gücü azaltmaktadır. Bu durumda
absorbsiyonlu soğutma sistemleri yenilenebilir enerji kaynakları ile
kullanıldığında oldukça kullanışlı olmaktadır. Bu çalışmada farklı soğutucu
akışkan çözeltilerinin bir absorpsiyonlu soğutma sisteminin performansı
üzerindeki etkilerini görebilmek için sistemin termodinamik ve ekserji analizi
yapılmıştır. Lityum bromür-Su (LiBr-H₂0), amonyak-su (NH₃-H₂0),
amonyak-lityum nitrat (NH₃-LiNO₃) ve amonyak-sodyum
tiyosiyanat (NH₃-NaSCN) akışkan çiftleri için absorbsiyonlu soğutma
sisteminde farklı jeneratör, buharlaştırıcı ve absorber sıcaklıklarında analiz
yapılarak sistemin Soğutma Tesir Katsayısı (STK) ve Ekserji Verimleri (%) her
bir akışkan çifti için incelenmiştir. Analiz sonuçları LiBr-H₂O
çözelti çiftinin diğer akışkan çiftlerine (NH₃-H₂O, NH₃-LiNO₃,
NH₃-NaSCN) göre daha iyi bir performansa sahip olduğunu
göstermiştir.

Anahtar Kelimeler

Ekserji, NH3, LiBr/H2O, NH3/NaSCN, absobsiyonlu soğutma sistemi

Kaynakça

• [1] Kaita, Y. "Thermodynamic properties of lithium bromide–water solutions at high temperatures." International Journal of refrigeration, 2001, 24 (5): 374-390. https://doi.org/10.1016/S0140-7007(00)00039-6
• [2] Florides, Georgios A., et al. "Design and construction of a LiBr–water absorption machine." Energy conversion and management, 2003, 44 (15): 2483-2508. https://doi.org/10.1016/S0196-8904(03)00006-2
• [3] Abdulateef, J. M., Sopian, K., Alghoul, M. A., Sulaiman, M. Y., Zaharim, A., & Ahmad, I. "Solar absorption refrigeration system using new working fluid pairs." International Journal of Energy, 2007, 1 (3): 82-87.
• [4] Crepinsek, Z., D. Goricanec, and J. Krope. "Comparison of the performances of absorption refrigeration cycles." Wseas transactions on heat and mass transfer, 2009, 4 (3): 65-76.
• [5] Manu, S., T. B. Prasad, and T. K. Chandrashekar. "Nagendra. Theortical Model of Absorber for Miniature LiBr-H2O Vapor Absorption Refrigeration System." Int J Mod Eng Res, 2012, 2: 10-7.
• [6] Patel, H. A., Patel, L. N., Jani, D., & Christian, A., “Energetic Analysis of Single Stage Lithium Bromide Water Absorption Refrigeration System.” Procedia Technology, 2016, 23: 488-495. https://doi.org/10.1016/j.protcy.2016.03.054
• [7] Farshi, L. G., Ferreira, C. I., Mahmoudi, S. S., & Rosen, M. A., “First and second law analysis of ammonia/salt absorption refrigeration systems.” international journal of refrigeration, 2014, 40: 111-121. https://doi.org/10.1016/j.ijrefrig.2013.11.006
• [8] Bouaziz, N., & Lounissi, D., “Energy and exergy investigation of a novel double effect hybrid absorption refrigeration system for solar cooling.” International journal of hydrogen energy, 2015, 40 (39): 13849-13856. https://doi.org/10.1016/j.ijhydene.2015.05.066
• [9] Ganesh, N. S., & Srinivas, T., “Evaluation of thermodynamic properties of ammonia-water mixture up to 100 bar for power application systems.” Journal of mechanical engineering research, 2011, 3 (1): 25-39.
• [10] Ziegler B, Trepp CH. “Equation of state for ammonia-water mixtures” Refrig., 1984, 7: 101-106.
• [11] Pa Patek, J., & Klomfor, J., “Simple Functions for Fast Calculations of Selected Thermodynamic Properties of the Ammonia-Water System.” Int.J.Refring, 1995, 4 (18): 228-234. https://doi.org/10.1016/0140-7007(95)00006-W
• [12] Anusha, B., & Chaitanya, B., “Performance Analysis of Absorption Refrigeration Cycles.” International Journal of Advanced Engineering Research and Science, 2017, 4 (1).
• [13] Kaushik, S., & Arora, A., “Energy and Exergy analysis of single effect and series flow double effect water lithium bromide absorption refrigeration systems.” International Journal of Refrigeration, 2009, 32: 1247-1258. https://doi.org/10.1016/j.ijrefrig.2009.01.017
• [14] Cai, D., He, G., Tian, Q., & Tang, W., “Exergy analysis of a novel air-cooled non-adiabatic absorption refrigeration cycle with NH3–NaSCN and NH3–LiNO3 refrigerant solutions.” Energy conversion and management, 2014, 88: 66-78. https://doi.org/10.1016/j.enconman.2014.08.025
• [15] Uemura, T., and S. Hasaba. "Studies on the lithium bromide-water absorption refrigerating machine." Technol. Rep. Kansai Univ, 1964, 6: 31-55.
• [16] Patterson MR, Perez-Branco H., “Numerical fits of the properties of lithium bromide-water solutions.” ASHRAE Trans, 1988, 94:2379-2388.
• [17] Ferreira, I., “Thermodynamic and Physical Property Data Equations for Ammonia-Lihtium Nitrate and Ammonia-Sodium Thiocyanate Solutions.” Solar Energy, 1984, 32 (2): 231-236.
• [18] Zhu, Linghui, and Junjie Gu. "Second law-based thermodynamic analysis of ammonia/sodium thiocyanate absorption system." Renewable Energy, 2010, 35 (9): 1940-1946. https://doi.org/10.1016/j.renene.2010.01.022
• [19] Bourseau, P., & Bugarel, R.. “Absorption-Diffusion Machines: Comparison of the Performances of NH3-H2O and NH3-NaSCN.” International Journal of Refrigeration, 1986, (9): 206-214. https://doi.org/10.1016/0140-7007(86)90092-7
• [20] K. Ç. Yağcıoğlu, “Thermodynamic and Exergy Analysis of An Absorption Cooling System For Different Refrigerants” , Master Thesis, Necmettin Erbakan University, Institute of Science, Mechanical Engineering, Konya, 2018.