Experimental Examination of Cooling System Performance with Eutectic Water-Salt Solutions as Phase Change Materials

Abstract

Household refrigerators are responsible for a huge amount of energy consumption due to their widespread use as household appliances and continuous operation. A laboratory-scale cooling system was operated at an average temperature of 4°C to investigate the performance of a household refrigerator without phase change material (PCM) and with various PCMs. Dipotassium hydrogen phosphate (K2HPO4) and sodium thiosulfate (Na2S2O3) solutions were integrated into the system at different concentrations as eutectic water-salt solution PCMs. It was revealed that the running time, determined to be 18.8% without PCM, decreased with the eutectic water-salt solutions prepared at suitable concentrations as PCMs. The running time (%) was minimized with 2.0 wt.% K2HPO4 solution. The running time was determined to be 11.1% with 2.0 wt.% K2HPO4 solution. The energy consumption was reduced by approximately 46% with 2.0 wt.% K2HPO4 solution than that of the case without PCM for a 4-hour operating period of the system. In the case of simulating a power failure, it was also determined that the time for reaching the cabin air temperature to ambient temperature (16℃) was prolonged with PCMs, and it was maximized to a value of approximately 5 times longer than that of the case without PCM. All evaluations indicate that the integration of suitable PCM into household refrigeration is of great importance in terms of reducing energy consumption. The integration of PCMs into systems will provide another advantage by ensuring the long-term preservation of products inside the cabinet during a power failure period.

Keywords

• Cooling system performance
• eutectic water-salt solutions
• household refrigerator
• phase change materials

Faz Değiştiren Malzeme Olarak Ötektik Su-Tuz Çözeltileri ile Soğutma Sistem Performansının Deneysel İncelenmesi

Abstract

Ev-tipi buzdolapları yaygın kullanılan beyaz eşyalar arasında yer alması ve sürekli çalışmaları sebebiyle yüksek miktarda enerji tüketiminden sorumludurlar. Ev-tipi buzdolabının performansını incelemek için laboratuvar ölçekli bir soğutma sistemi ortalama 4°C sıcaklıkta faz değiştiren malzemesiz (FDM’siz) ve çeşitli FDM’lerle test edilmiştir. FDM olarak ötektik su-tuz çözeltilerinden dipotasyum hidrojenfosfat (K2HPO4) ve sodyum tiyosülfat (Na2S2O3) çözeltileri farklı konsantrasyonlarda sisteme entegre edilmiştir. FDM’siz durumda %18,8 tespit edilen çalışma süresinin FDM olarak, uygun konsantrasyonlarda hazırlanan ötektik su-tuz çözeltileri ile azaldığı ortaya konulmuştur. FDM olarak ağırlıkça (ağ.) %2,0 K2HPO4 çözeltisi ile çalışma süresi (%) minimize edilmiştir. Çalışma süresi ağ. %2,0 K2HPO4 çözeltisi ile %11,1 olarak tespit edilmiştir. FDM’siz durumda sistemin 4 saatlik çalışma süresinde belirlenen toplam enerji tüketimi ağ. %2,0 K2HPO4 çözeltisi ile yaklaşık %46 oranında azaltılmıştır. Elektrik kesintisinin simüle edildiği durumda ise FDM’ler sisteme entegre edildiğinde kabin iç hava sıcaklığının ortam sıcaklığına (16℃) yükselme süresinin uzadığı ve maksimim olduğu durumda bu süresinin FDM’siz duruma göre yaklaşık 5 kat uzadığı belirlenmiştir. Tüm değerlendirmeler uygun FDM’nin ev-tipi buzdolaplarına entegrasyonun enerji tüketiminin azaltılmasında önemli rol oynacağı ortaya konulmuştur. Elektrik kesintisi periyodunda, kabin içindeki ürünlerin uzun süre bozunmadan muhafaza edilmesi FDM’lerin sistemlere entegrasyonunda sağlanacak diğer bir avantaj olacaktır.

Keywords

• Ev-tipi buzdolabı
• faz değiştiren malzemeler
• soğutma sistem performansı
• ötektik su-tuz çözeltileri

References

1. D. Coulomb, Refrigeration and cold chain serving the global food industry and creating a better future: two key IIR challenges for improved health and environment, Trends in Food Science & Technology 19 (8) (2008) 413–417.
2. Energy Information Administration (EIA), Residential Energy Consumption Survey (2001), https://www.eia.gov/consumption/residential/data/2001/index.php?view=consumption, Accesed 4 Nov 2023.
3. T. M. I, Mahlia, H. H. Masjuki, R. Saidur, I. A. Choudhury, A. R. NoorLeha, Projected electricity savings from implementing minimum energy efficiency standard for household refrigerators in Malaysia, Energy 28 (7) (2003) 751–754.
4. A. C. Marques, G. F. Davies, G. G. Maidment, J. A. Evans, I. D. Wood, Novel design and performance enhancement of domestic refrigerators with thermal storage, Applied Thermal Engineering 63 (2) (2014) 511–519.
5. D. Y. Liu, W. R. Chang, J. Y. Lin, Performance comparison with effect of door opening on variable and fixed frequency refrigerators/freezers, Applied Thermal Engineering 24 (14-15) (2004) 2281–2292.
6. P. K. Bansal, Developing new test procedures for domestic refrigerators: harmonisation issues and future R&D needs—a review, International Journal of Refrigeration 26 (7) (2003) 735–748.
7. M. I. H. Khan, Conventional refrigeration systems using phase change material: a review, International Journal of Air-Conditioning and Refrigeration 24 (03) (2016) 1630007 16 pages.
8. L. Abdolmaleki, S. M. Sadrameli, A. Pirvaram, Application of environmental friendly and eutectic phase change materials for the efficiency enhancement of household freezers, Renewable Energy 145 (2020) 233–241.

9. B. Kiran Yildirim, Performance evaluation of a laboratory-scale cooling system as a household refrigerator with phase change materials, Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 44 (3) (2022) 5852–5867.
10. A. Pirvaram, S. M. Sadrameli, L. Abdolmaleki, Optimization of energy consumption and temperature fluctuations for a household freezer using non‐toxic and non‐flammable eutectic phase change materials with a cascade arrangement, International Journal of Energy Research 45 (2) (2021) 1775–1788.
11. E. Oró, A. De Gracia, A. Castell, M. M. Farid, L. F. Cabeza, Review on phase change materials (PCMs) for cold thermal energy storage applications, Applied Energy 99 (2012) 513–533.
12. W. Su, J. Darkwa, G. Kokogiannakis, Review of solid–liquid phase change materials and their encapsulation technologies, Renewable and Sustainable Energy Reviews 48 (2015) 373–391.
13. K. Azzouz, D. Leducq, D. Gobin, Enhancing the performance of household refrigerators with latent heat storage: An experimental investigation, International Journal of Refrigeration 32 (7) (2009) 1634–1644.
14. G. Li, Y. Hwang, R. Radermacher, H. H. Chun, Review of cold storage materials for subzero applications, Energy 51 (2013) 1–17.
15. G. A. Lane, Solar heat storage: Volume I: Latent heat material, Boca Raton, CRC Press, 1983.
16. H. P. Garg, S. C. Mullick, A. K. Bhargava, Solar thermal energy storage, D. Reidel Publishing Company, Dordecht, 1985.
17. Y. Tek, Synthesis, characterization and physicochemical properties of urea and thiourea-fatty acid condensation compounds, Master’s Thesis Tokat Gaziosmanpaşa Universiy (2009) Tokat.
18. B. Kiran Yildirim, T. Noya, E. Mancuhan, S. Titiz Sargut, Investigation of energy consumption for a PCM integrated laboratory scale cooling system: An experimental ctudy, in: N. Yücel, R. Yumrutaş, M. S. Söylemez, M. Kanoğlu, Â. Atmaca, H. Yağlı (Eds.), 23rd Congress on Thermal Science and Technology with International Participation, 2021, Gaziantep, pp. 1002–1008.
19. Y. Yusufoglu, T. Apaydin, S. Yilmaz, H. O. Paksoy, Improving performance of household refrigerators by incorporating phase change materials, International Journal of Refrigeration 57 (2015) 173–185.
20. M. A. Ezan, E. O. Doganay, F. E. Yavuz, I. H. Tavman, A numerical study on the usage of phase change material (PCM) to prolong compressor off period in a beverage cooler, Energy Conversion And Management 142 (2017) 95–106.
21. M. I. H. Khan, H. M. Afroz, Effect of phase change material on compressor on-off cycling of a household refrigerator, Science and Technology for the Built Environment 21 (4) (2015) 462–468.
22. D. S. Niyaj, S. N. Sapali, Performance evaluation of a domestic refrigerator with a thermal storage arrangement using propane as a refrigerant, Energy Procedia 109 (2017) 34–39.
23. I. H. Khan, H. M. Afroz, M. A. Karim, Effect of PCM on temperature fluctuation during the door opening of a household refrigerator, International Journal of Green Energy 14 (4) (2017) 379–384.