Karbondioksitli Kaskad Soğutma Sistemlerinin Enerji Performans Değerlendirilmesi

Year 2020, , 22 - 32, 13.03.2020

Tuğba Kovacı

https://doi.org/10.31200/makuubd.669252

Abstract

Bu
çalışmada, R744 + R717 / R1234ze / R134a / R152a soğutkanları kullanılan dört
farklı kaskad sisteminin karşılaştırılması sunulmuştur. Analiz -45°C’den
-20°C’ye değişen farklı evaporatör sıcaklıklarında ve 30°C’den 50°C’ye değişen
farklı kondenser sıcaklıklarında gerçekleştirilmiştir. Evaporatör sıcaklığı
25°C arttırıldığında, tüm sistemin soğutma performansı (COP_SYS)
değeri yaklaşık %60 ila %64 arasında artmış ve kompresör gücü de yaklaşık %38
oranında azalmıştır. Kondenser sıcaklığının 20°C arttırılması, COP_SYS'de
%29 34 oranında bir azalmaya ve kompresör gücünde yaklaşık %38-50 oranında bir
artışa neden olmuştur. Sonuçlara göre, düşük küresel ısınma potansiyeli (GWP)
ve yüksek soğutma performansı değerine sahip olan R744/R717 soğutucu
akışkanları kullanılan "sistem 1" kombinasyonunun, incelenen diğer
kaskad soğutma sistemlerinden daha verimli olduğunu belirlenmiştir. 

Keywords

Kaskad Soğutma, R744, COP

Energy Performance Assessment of CO2 Cascade Refrigeration Systems

Abstract

In
this study, a comparison of the four different cascade systems using
R744+R717/R1234ze/R134a/R152a refrigerant pairs has been presented. The
analysis has been performed for different evaporator temperatures ranged from
-45 up to -20°C, and different condenser temperatures ranged from 30 up to
50°C. When the evaporator temperature has been increased by 25°C, the system
cooling performance (COP_SYS) value has increased by about 60% to
64%, and the compressor work has decreased by about 38%. Increasing the
condenser temperature by 20°C has resulted in a decrease in COP_SYS
of 29-34% and an increase in compressor work by about 38% to 50%. According to
the results, the combination of “system 1” using R744/R717 refrigerants which
having low GWP and high cooling performance has been determined more efficient
than other examined cascade refrigeration systems. 

Keywords

Cascade Refrigeration, R744, COP

References

• Alhamid, M. I. & Syaka, D. R. (2010). Exergy and energy analysis of a cascade refrigeration system using R744+ R170 for low temperature applications. International Journal of Mechanical & Mechatronics Engineering, 10(6),1-8.
• Aminyavari, M., Najafi, B., Shirazi, A., & Rinaldi, F. (2014). Exergetic, economic and environmental (3E) analyses, and multi-objective optimization of a CO2/NH3 cascade refrigeration system. Applied Thermal Engineering, 65(1-2), 42-50.
• Başaran, A., & Özgener, L. (2013). Doğaya zararlı halokarbon soğutkanların çevresel etkileri ve alınan önlemler. Engineer & the Machinery Magazine, 640.
• Boyaghchi, F. A., & Asgari, S. (2017). A comparative study on exergetic, exergoeconomic and exergoenvironmental assessments of two internal auto-cascade refrigeration cycles. Applied Thermal Engineering, 122, 723-737.
• da Silva, A., Bandarra Filho, E. P., & Antunes, A. H. P. (2012). Comparison of a R744 cascade refrigeration system with R404A and R22 conventional systems for supermarkets. Applied Thermal Engineering, 41, 30-35.
• Dopazo, J. A., Fernández-Seara, J., Sieres, J., & Uhía, F. J. (2009). Theoretical analysis of a CO2–NH3 cascade refrigeration system for cooling applications at low temperatures. Applied Thermal Engineering, 29(8-9), 1577-1583.
• EES, 2016. Engineering Equation Solver, F-Chart Software.
• Khanmohammadi, S., Goodarzi, M., Khanmohammadi, S., & Ganjehsarabi, H. (2018). Thermoeconomic modeling and multi-objective evolutionary-based optimization of a modified transcritical CO2 refrigeration cycle. Thermal Science and Engineering Progress, 5, 86-96.
• Lizarte, R., Palacios-Lorenzo, M. E., & Marcos, J. D. (2017). Parametric study of a novel organic Rankine cycle combined with a cascade refrigeration cycle (ORC-CRS) using natural refrigerants. Applied Thermal Engineering, 127, 378-389.
• Llopis, R., Sánchez, D., Sanz-Kock, C., Cabello, R., & Torrella, E. (2015). Energy and environmental comparison of two-stage solutions for commercial refrigeration at low temperature: Fluids and systems. Applied Energy, 138, 133-142.
• Mancuhan, E., Tunç, B., Yetkin, K., & Çelik, C. (2019). Comparative analysis of cascade refrigeration systems’ performance and enviromental impacts, Journal of the Turkish Chemical Society Section B: Chemical Engineering, 2 (2), 97-108.
• Messineo, A. (2012). R744-R717 cascade refrigeration system: performance evaluation compared with a HFC two-stage system. Energy Procedia, 14, 56-65.
• Mishra, R.S., 2018. Thermodynamic analysis of two stages cascade refrigeration system using r-1234ze in high temperature circuit and r1234yf in low temperature circuit for replacing HFC (R-134a) refrigerant, International Journal of Research in Engineering and Innovation, 2 (4), 364-373.
• Oruç, V., Devecioğlu, A. G., & Ender, S. (2018). Improvement of energy parameters using R442A and R453A in a refrigeration system operating with R404A. Applied Thermal Engineering, 129, 243-249.
• Parmar, G. G., & Kapadia, D. R. (2015). Thermodynamic analysis of cascade refrigeration system using a natural refrigerants for supermarket application. International Journal of Innovative Research in Science, Engineering and Technology. 4(6), 1839- 1846.
• Singh, S., & Dasgupta, M. S. (2016). Thermodynamic analysis of a low TEWI (R1234yf-R744) cascade system, National Conference on Recent Trends in Mechanical Engineering, India.
• Yilmaz, B., Erdonmez, N., Sevindir, M. K., & Mancuhan, E. (2014). Thermodynamic analysis and optimization of cascade condensing temperature of a CO2 (R744)/R404A cascade refrigeration system. International Refrigeration and Air Conditioning Conference. ABD
• Yılmaz, F. & Selbaş, R. (2017). Energy and exergy analyses of CO2/HFE7000 cascade cooling system, Süleyman Demirel Üniversitesi Fen Bilimleri Enstitüsü Dergisi, 21 (3), 854-860.