Exergy Calculations and Refrigerant Selection Using Flue Gas Waste Heat in Organic Rankine Cycle

Year 2025, Volume: 28 Issue: 3, 1019 - 1033, 13.06.2025

Muhsine Saru , Adnan Sözen , Erhan Pulat

https://doi.org/10.2339/politeknik.1699559

Abstract

In this study, the second law efficiency of the organic Rankine cycle (ORC) designed was calculated for each of refrigerants, and the exergies of the ORC components were examined separately. Candidate refrigerants were determined for comparison. When determining candidate refrigerants, the first thing to consider was the low boiling point temperature. Five candidate refrigerants were determined for comparison purposes, namely R290, R600a, R32, R125, R143a. When determining candidate refrigerants, importance was given to the criterion that their boiling temperature should be lower than the boiling temperature of water. The refrigerant with the highest exergy efficiency was selected as the most suitable refrigerant among the candidate refrigerants. The temperature of sink has been taken as a value that lower than the boiling point temperature o the refrigerant that has the lowest boiling point temperature among the others instead of ambient temperature.The power generation, first law efficiency and second law efficiency of R32were found to be 170,3 kJ/kg, 0,3049 and 0,284, respectively.The thermal efficiency and second law efficiency values of the ORC using R32 are higher than those using other refrigerants for conditions in the considered textile plant.

Keywords

Second law Efficiency , ORC , Exergy Analysis , working refrigerant

Organik Rankine Çevriminde Baca Gazı Atık Isısının Kullanılmasıyla Ekserji Hesaplamaları ve Soğutucu Seçimi

Abstract

Bu çalışmada, tasarlanan organik Rankine çevriminin (ORÇ) ikinci yasa verimliliği her bir soğutucu için hesaplanmış ve ORC bileşenlerinin ekserjileri ayrı ayrı incelenmiştir. Karşılaştırma için aday soğutucular belirlenmiştir. Aday soğutucular belirlenirken, dikkate alınması gereken ilk şey düşük kaynama noktası sıcaklığıdır. Karşılaştırma amacıyla beş aday soğutucu belirlenmiştir: R290, R600a, R32, R125, R143a. Aday soğutucular belirlenirken, kaynama sıcaklıklarının suyun kaynama sıcaklığından düşük olması kriterine önem verilmiştir. Aday soğutucular arasında en yüksek ekserji verimliliğine sahip soğutucu en uygun soğutucu olarak seçilmiştir. Soğuk kaynak sıcaklığı, ortam sıcaklığı yerine diğerleri arasında en düşük kaynama noktası sıcaklığına sahip olan soğutucunun kaynama noktası sıcaklığından daha düşük bir değer olarak alınmıştır. R32'nin güç üretimi, birinci yasa verimi ve ikinci yasa verimi sırasıyla 170,3 kJ/kg, 0,3049 ve 0,284 olarak bulunmuştur. R32 kullanan ORC'nin termal verimi ve ikinci yasa verimi değerleri, ele alınan tekstil tesisindeki koşullar için diğer soğutucularınkinden daha yüksek bulunmuştur.

Keywords

İkinci yasa Verimliliği , ORÇ , Ekserji Analizi , çalışma soğutucu akışkanı

References

• [1] Abdallah, L. and El-shennawy, T., “A Feasibility Study for Utilizing Waste Heat to Generate Electrical Power Using Organic Rankine Cycle (ORC).” (May). (2023).
• [2] Ahmed, A. M. and Imre, A. R., “Investigation of Thermal Efficiency for Subcritical ORC and TFC Using Super Dry Working Fluids.” 711–26., (2023).
• [3] Al-Badri ,D. H., Al-Hamadani, A. A. F. and Ridha, H., “The Influence of Condenser Temperature on the Energy and Exergy Efficiencies of the ORC.” Wasit Journal of Engineering Sciences 10(3):134–44. (2022).
• [4] Araya, S., Wemhoff, A. P., Jones, G. F. and Fleischer, A. S., “Study of a Lab-Scale Organic Rankine Cycle for the Ultra-Low-Temperature Waste Heat Recovery Associated with Data Centers.” Journal of Electronic Packaging, Transactions of the ASME 143(2). (2021).
• [5] Asim, M., Kashif, F., Umer, J., Alvi, J. Z., Imran, M., Khan, S.., Zia, A. W. and Leung, M. K. H., “Performance Assessment and Working Fluid Selection for Novel Integrated Vapor Compression Cycle and Organic Rankine Cycle for Ultra Low Grade Waste Heat Recovery.” (2021).
• [6] Caglar, A. and Bahadır, M. B., “Thermodynamic Analysis of Solar Organic Rankine Cycle Using Evacuated Tubular Collector “,Politeknik Dergisi, 26(4) :1341-1347, (2023).
• [7] Dominguez, J. G., Marigorta, A. M. B. and Marcos, J. D., “Analysis of a Solar Driven ORC-Absorption Based CCHP System from a Novel Exergy Approach Energy Conversion and Management : X Analysis of a Solar Driven ORC-Absorption Based CCHP System from a Novel Exergy Approach.” Energy Conversion and Management: X. (2023).
• [8] Hakim, A. T., Jasmine, A. P. P, Juwari, J. and Renanto, H., “Analysis of Geothermal Power Plant Process Design for Lahendong Expansion Area, Politeknik Dergisi, (2024).
• [9] Kaska, O., “Energy and Exergy Analysis of an Organic Rankine for Power Generation from Waste Heat Recovery in Steel Industry.” 77:108–17., (2014).
• [10] Meneses, L. R., Silva, J. C., Cota, S. and Kikas ,T. , “Thermodynamic, Environmental and Economic Simulation of an Organic Rankine Cycle (ORC) for Waste Heat Recovery: Terceira Island Case Study.” Environmental and Climate Technologies 23(2):347–65. (2019).
• [11] MiniREFPROP9.5https://minirefprop.software.informer.com/9.5/ (Accessed in May 23, 2023)
• [12] Obi, J. B., “State of Art on ORC Applications for Waste Heat Recovery and Micro-Cogeneration for Installations up to 100kWe.” Energy Procedia 82:994–1001, (2015).
• [13] Petrollese, M., Oyekale, J., Tola, V. and Cocco, D., “Optimal ORC Configuration for the Combined Production of Heat and Power Utilizing Solar Energy and Biomass.” ECOS 2018 - Proceedings of the 31st International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems ,(2018).
• [14] Kılıc, A. E. and Arcaklioglu, E., Doğalgaz Yakıtlı Bir Kombine Çevrim Santralinin Enerji ve Ekserji Analizi: Parametrik Çalışma, Politeknik Dergisi, 26(2): 721-730, (2023).
• [15] Siddiqui, M. E., Almatrafi,E., Saeed , U. and Taimoor, A. A., “Selection of Organic Fluid Based on Exergetic Performance of Subcritical Organic Rankine Cycle (ORC) for Warm Regions.”, (2023).
• [16] URL‐1, https://www.hrai.ca/uploads/userfiles/files/refrigerant_table, 06 March, (2025).
• [17] URL‐2, https://www.daikinchem.de/sites/default/files/pdf/Refrigerants/Daikin_R407H_introduction_171128.pdf, 06 March, (2025).