Enhancement of the cooling performance of an electrical power transformer using geometrical parameters

Hashim, Marwa Mohammed; Basher, Hadi O.

doi:10.30772/qjes.2024.154157.1408

	Enhancement of the cooling performance of an electrical power transformer using geometrical parameters
Al-Qadisiyah Journal for Engineering Sciences
Volume 18, Issue 3, September 2025, Pages 272-280 PDF (16.64 M)
Document Type: Research Paper
DOI: 10.30772/qjes.2024.154157.1408
Authors
Marwa Mohammed Hashim; Hadi O. Basher^*
Department of Mechanical Engineering, College of Engineering, University of Wasit, Wasit, Iraq.
Abstract
This study investigates the influence of electrical transformer shape and fin configuration on the cooling process, emphasizing performance under varying ambient temperatures. Cooling efficiency is critical for transformer reliability, longevity, and operational safety. Traditional transformer shapes often face limitations in heat dissipation, leading to potential hotspots that can affect performance. This research utilized numerical simulations and experimental validation to compare various transformer shapes and fin configurations, focusing particularly on a 250 KVA Oil Natural Air Natural (ONAN) type transformer designed with real-world specifications. Key findings indicated that a hexagonal transformer shape and zigzag-shaped fins with rib configurations spaced at 7 cm intervals provided superior cooling efficiency. This optimized design resulted in a maximum stable temperature of approximately 332.31 K, significantly lower than that observed in traditional rectangular designs. The zigzag fins increased the effective surface area for heat dissipation, facilitating improved thermal performance. Numerical analysis using ANSYS Fluent demonstrated enhanced coolant flow and uniform pressure distribution, with higher coolant velocity reaching 0.252 m/s. This uniformity mitigated potential hotspots and mechanical stress, contributing to overall structural integrity. Experimental validation was conducted under Iraqi weather conditions, reinforcing the numerical results. Temperature tests confirmed that the optimized hexagonal design consistently maintained lower oil and component temperatures than traditional shapes. This study used Finite Element Analysis (FEA) to investigate the impact of changes in geometrical parameters. A theoretical approach based on classical mechanics was applied, where force distribution was modeled using elasticity theory. The percentage difference represents 5.26\% of Coil temperature, 5.1\% of Oil temperature, and 5.25 \% of fins temperature, where the percentage difference represents 1.52\% of all coil temperature, comparing the optimum case with previous research with experimental tests.
Keywords
Transformer cooling; ONAN; Numerical model validation; Fin shape optimization; Experimental, ANSYS fluent

References
Aich, Adnan, H. Almujibah, S. Shukhratovich Abdullaev, M. Z. Bani-Fwaz, and A.MHassan, “Thermal performance of radiated annular extended surface using advanced nanomaterials influenced by various physical controlling parameters for nucleate boiling case,” Case Studies in Thermal Engineering, vol. 51, p. 103524, 2023. [Online]. Available: https://doi.org/10.1016/j.csite.2023.103524 Almheidat, Z. Ullah, M. M. Alam, M. Boujelbene, A. Ebaid, M. Alsulami, S. Alhumaid, and A. O. Ibrahim, “Entropy generation analysis of oscillatory magnetized darcian flow of mixed thermal convection and mass transfer with joule heat over radiative sheet,” Case Studies in Thermal Engineering, vol. 61, p. 104921, 2024. [Online]. Available: https://doi.org/10.1016/j.csite.2024.104921 Stebel, K. Kubiczek, G. Rios Rodriguez, M. Palacz, L. Garelli, B. Melka, M. Haida, J. Bodys, A. J. Nowak, P. Lasek, M. Stepien, F. Pessolani, M. Amadei, D. Granata, M. Storti, and J. Smolka, “Thermal analysis of 8.5 mva disk-type power transformer cooled by biodegradable ester oil working in onan mode by using advancedemag–cfd–cfd coupling,” International Journal of Electrical Power Energy Systems, vol. 136, p. 107737, 2022. [Online]. Available: https://doi.org/10.1016/j.ijepes.2021.107737 Jusner, E. Schwaiger, A. Potthast, and T. Rosenau, “Thermal stability of cellulose insulation in electrical power transformers – a review,” Carbohydrate Polymers, vol. 252, p. 117196, 2021. [Online]. Available: https://doi.org/10.1016/j.carbpol.2020.117196 -M. Lai and J. Teh, “Comprehensive review of the dynamic thermal rating system for sustainable electrical power systems,” Energy Reports, vol. 8, pp. 3263–3288, 2022. [Online]. Available: https://doi.org/10.1016/j.egyr.2022.02.085 Khashaei, M. Ameri, and S. Azizifar, “Heat transfer enhancement and pressure drop performance of al2o3 nanofluid in a laminar flow tube with deep dimples under constant heat flux: An experimental approach,” International Journal of Thermofluids, vol. 24, p. 100827, 2024. [Online]. Available: https://doi.org/10.1016/j.ijft.2024.100827 E. Zayed, J. Zhao, A. H. Elsheikh, W. Li, S. Sadek, and M. M. Aboelmaaref, “A comprehensive review on dish/stirling concentrated solar power systems: Design, optical and geometrical analyses, thermal performance assessment, and applications,” Journal of Cleaner Production, vol. 283, p. 124664, 2021. [Online]. Available: https://doi.org/10.1016/j.jclepro.2020.124664 Ma, Y. Wang, W. Qin, H. Zhou, C. Yan, J. Jiang, and Y. Ju, “Optical sensors for power transformer monitoring: A review,” High Voltage, vol. 6, no. 3, pp. 367–386, 2021. [Online]. Available: https://doi.org/10.1049/hve2.12021 I. Abdelwanis, A. Abaza, R. A. El-Sehiemy, M. N. Ibrahim, and H. Rezk, “Parameter estimation of electric power transformers using coyote optimization algorithm with experimental verification,” IEEE Access, vol. 8, pp. 50 036–50 044, 2020. [Online]. Available: https://doi.org/10.1109/ACCESS.2020.2978398 H. Aziz, M. M. Azizan, Z. Sauli, and M. W. Yahya, “A review on harmonic mitigation method for non-linear load in electrical power system,” AIP Conference Proceedings, vol. 2339, no. 1, p. 020022, 05, 2021. [Online]. Available: https://doi.org/10.1063/5.0044251 Battal, S. Balci, and I. Sefa, “Power electronic transformers: A review,” Measurement, vol. 171, p. 108848, 2021. [Online]. Available: https://doi.org/10.1016/j.measurement.2020.108848 Chamarthi and S. Singh, “A comprehensive review of experimental investigation procedures and thermal performance enhancement techniques of solar air heaters,” International Journal of Energy Research, vol. 45, no. 4, pp. 5098–5164, 2021. [Online]. Available: https://doi.org/10.1002/er.6255 F. Yousif and M. A. Theeb, “A review of solar air collectors with baffles and porous medium: Types and applications,” Al-Qadisiyah Journal for Engineering Sciences, vol. 16, no. 1, pp. 37–41, 2023. [Online]. Available: https://doi.org/10.30772/qjes.v16i1.841 Yusupov, D.T., Ismoilov, I.K., Norboev, A.E., Beytullaeva, R.X., and Yuldashev, A.A., “Development of a simulation model for assessing the technical condition of oil power transformers by measuring vibroacoustic parameters,” E3S Web of Conf., vol. 510, p. 04014, 2024. [Online]. Available: https://doi.org/10.1051/e3sconf/202451004014 Toirov, Olimjon, Alimkhodjaev, Kamoliddin, and Pardaboev, Akhror, “Analysis and ways of reducing electricity losses in the electric power systems of industrial enterprises,” E3S Web Conf., vol. 288, p. 01085, 2021. [Online]. Available: https://doi.org/10.1051/e3sconf/202128801085 M. Emara, G. D. Peppas, and I. F. Gonos, “Two graphical shapes based on dga for power transformer fault types discrimination,” IEEE Transactions on Dielectrics and Electrical Insulation, vol. 28, no. 3, pp. 981–987, 2021. [Online]. Available: https://doi.org/10.1109/TDEI.2021.009415 Nada, H. Elattar, M. Mahmoud, and A. Fouda, “Performance enhancement and heat and mass transfer characteristics of direct evaporative building free cooling using corrugated cellulose papers,” Energy, vol. 211, p. 118678, 2020. [Online]. Available: https://doi.org/10.1016/j.energy.2020.118678 K. Mohsen and N. H. Hamza, “Investigation of laminar forced convection using a different shape of a heat sink,” Al-Qadisiyah Journal for Engineering Sciences, vol. 15, no. 2, pp. 73–79, 2022. [Online]. Available: https://doi.org/10.30772/qjes.v15i2.816 Soni and B. Mehta, “Review on asset management of power transformer by diagnosing incipient faults and faults identification using various testing methodologies,” Engineering Failure Analysis, vol. 128, p. 105634, 2021. [Online]. Available: https://doi.org/10.1016/j.engfailanal.2021.105634 Shiravand, J. Faiz, M. H. Samimi, and M. Djamali, “Improving the transformer thermal modeling by considering additional thermal points,” International Journal of Electrical Power Energy Systems, vol. 128, p. 106748, 2021. [Online]. Available: https://doi.org/10.1016/j.ijepes.2020.106748 Taghikhani, M. A. Taghikhani, and G. Gharehpetian, “A comprehensive investigation on the efficiency of alumina nanoparticles in onan and ofan cooling performance enhancement of transformers,” Powder Technology, vol. 387, pp. 466–480, 2021. [Online]. Available: https://doi.org/10.1016/j.powtec.2021.04.031 B. M. Taha, S. Ibrahim, and D.-E. A. Mansour, “Power transformer fault diagnosis based on dga using a convolutional neural network with noise in measurements,” IEEE Access, vol. 9, pp. 111 162–111 170, 2021. B. Taha and D.-E. A. Mansour, “Novel power transformer fault diagnosis using optimized machine learning methods,” Intelligent Automation & Soft Computing, vol. 28, no. 3, pp. 739–752, 2021. [Online]. Available: https://doi.org/10.32604/iasc.2021.017703 Zanella, C. Nore, X. Mininger, F. Bouillault, and J.-L. Guermond, “Numerical study of cooling by ferrofluids in an electrical transformer using an axisymmetric model,” IEEE Transactions on Magnetics, vol. 57, no. 7, pp. 1–4, 2021. [Online]. Available: https://doi.org/10.1109/TMAG.2021.3066412 Almosawy and H. Basher, “Numerical analysis of the impact of fin design and solar radiation on the cooling performance of a power transformer,” Wasit Journal of Engineering Sciences, vol. 11, no. 2, p. 1–11, Aug. 2023. [Online]. Available: https://doi.org/10.31185/ejuow.Vol11.Iss2.445 M. Azbar, H. M. Jaffal, and B. Freegah, “Enhancement of the thermal performance characteristics of an electrical power transformer,” Engineering Science and Technology, vol. 2, no. 1, p. 1–21, 2020. [Online]. Available: https://doi.org/10.37256/est.212021487 Jaffal and N. M. Azbar, “Experimental study of the thermal performance behavior of electric power transformers,” Journal of Engineering and Sustainable, 2020.
Statistics Article View: 942 PDF Download: 1,946