THERMAL SCIENCE

International Scientific Journal

Thermal Science - Online First

online first only

Enhancing microwave oven performance and transformer quality through efficient high voltage transformer cooling

ABSTRACT
This paper describes a method and device for effectively cooling a high voltage transformer inside a microwave oven, with the aim of swiftly removing heat generated during operation, hence improving both the microwave oven's and the transformer's performance and quality. The device incorporates corrugated tank surfaces, electrical connection lines with protrusions, and epoxy to prevent cooling oil leakage. The transformer is inserted into a designated tank and sealed to separate the coil and core from the outside environment, allowing for better cooling and protection against electrical shock. Additionally, an oil is injected to absorb heat generated by the high temperature of the core and coil. The effectiveness of this method is validated through the finite element method and computational fluid dynamics techniques. Numerical analysis revealed a significant decrease in the maximum temperature rise of the transformer by around 44.2°C. This finding suggests that transformer oil cooling is a more effective method for controlling temperature rise in microwave ovens compared to traditional cooling methods.
KEYWORDS
PAPER SUBMITTED: 2023-10-21
PAPER REVISED: 2024-03-01
PAPER ACCEPTED: 2024-03-11
PUBLISHED ONLINE: 2024-05-18
DOI REFERENCE: https://doi.org/10.2298/TSCI231021109O
REFERENCES
  1. El Wakil, N., et al., Numerical Study of Heat Transfer and Fluid Flow in a Power Transformer, International Journal of Thermal Sciences, 45 (2006) ,6, pp. 615-626
  2. Smolka, J., et al., Numerical Modelling of Thermal Processes in an Electrical Transformer Dipped into Polymerized Resin by using Commercial CFD Package Fluent, Computers and Fluids, 33 (2004), 5-6, pp. 859-868
  3. Smolka, J., et al., Enhanced Numerical Model of Performance of An Encapsulated Three-Phase Transformer in Laboratory Environment, Applied Thermal Engineering, 27 (2007),1, pp.156-166
  4. Smolka, J., et al., Experimental Validation of The Coupled Fluid Flow, Heat Transfer and Electromagnetic Numerical Model of The Medium-Power Dry-Type Electrical Transformer, International Journal of Thermal Sciences, 47 (2008),10, pp. 1393-1410
  5. Hannun, R. M., et al., Heat Transfer Enhancement From Power Transformer Immersed In Oil By Earth Air Heat Exchanger, Thermal Science, 23 (2019), 6A, pp. 3591-3602
  6. D, XU., et al., Analysis of Winding Temperature Field under Dynamic Variable Load uf Oil-Immersed Transformer, Thermal Science, 25 (2021), 4B, pp.3009-3019
  7. Wang Zeng-ping., Calculation of Leakage Inductance in Transformer Based on ANSYS, Journal of Shantou University, 23(2008), pp. 63-68
  8. Jing, F., Simulation and Calculation of ANSYS-based Magnetic Leakage Transformer, Modern Electronics Technique, 2011
  9. Pierce, L., Predicting Hottest Spot Temperatures in Ventilated Dry Type Transformer Windings, IEEE Transactions on Power Delivery, 9 (1994), 2, pp.1160-1172
  10. teNyenhuis, Ed. G., et al., Calculation of Core Hot-Spot Temperature in Power and Distribution Transformers, IEEE Transactions on Power Delivery, 17 (2002) , 4, pp. 991-995
  11. Hwang, C. C., et al., Thermal Analysis of High Frequency Transformers Using Finite Elements Coupled with Temperature Rise Method, IEE Proceedings - Electric Power Applications, 152 (2005), 4, pp. 832-836
  12. Lefevre, A., et al., 3-D Computation of Transformers Overheating under Nonlinear Loads, IEEE Transactions on Magnetics, 41(2005), 5, pp. 1564-1567
  13. Tsili, M. A., et al., Hybrid Numerical-Analytical Technique for Power Transformer Thermal Modeling, IEEE Transactions on Magnetics, 45 (2009) , 3, pp. 1408-1411
  14. Rosas, C., et al., Improvement of The Cooling Process of Oil-Immersed Electrical Transformers Using Heat Pipes, IEEE Transactions on Power Delivery, 20 (2005), 3, pp. 1955-1961
  15. Nakata, T., Takahashi, N., Finite Element Analysis of Transformer Cores, Memoirs of the School of Engineering, 18(1984),1, pp. 1-31
  16. Enokizono, M., Soda, N., Core Loss Analysis of Transformer by Improved FEM, Journal of Magnetism and Magnetic Materials, 196(1999),1, pp. 910-912
  17. Ding, L., et al., Temperature Field Simulation Research on The Leakage Inductance Transformer, Thermal Science, 22 (2018), 2, pp.649-654
  18. C.P, Steinmetz., On the law of hysteresis, Proceedings of The IEEE, 72(1964), 2, pp.197-221
  19. A,Brooks.,T.J.R, Hughes.,Streamline upwind/petrov-galerkin formulations for convection dominated flows with particular emphasis on the incompressible navier-stokes equations. Computer Methods in Applied Mechanics and Engineering. 32(2015), 1-3, pp.199-259
  20. Heinrich, J.C., et al., A.R. An ‘upwind' finite element scheme for two-dimensional convective transport equation. Int. J. Numer. Methods Eng. 11(1977), 131-143.
  21. Lahame, M., et al.,. Optimization of a three-phase tetrahedral high voltage transformer used in the power supply of microwave. International Journal of Advanced Computer Science and Applications,10(2019), 5, pp. 268-273.
  22. Chraygane, M., et al.,. Improved modeling of new three-phase high voltage transformer with magnetic shunts. Archives of Electrical Engineering, 64(2015), 1, pp. 157-172.