METHOD OF INDIRECT DETERMINATION OF THERMAL LOAD PARAMETER

An indirect method for determining the effectiveness of the transformers operating in a distribution network with variable load schedules, according to the parameter of their thermal load as a ratio of heat accumulated by transformer oil to the maximum permissible heat is proposed provided the thermal stability of the insulation. a mathematical model is developed which allows establishing analytically the forced temperature value and time invariable of heating or cooling on the section of the time dependence of the oil temperature, as well as an algorithm for calculating the amount of heat accumulated by the oil and the coefficient of heat transfer from the oil to the transformer tank is compiled. approbation of the indirect method indicates that the divergence between the transformer oil heating time invariable which was obtained by solving the differential equation of thermal balance and calculated using the part of temperature dependence of its heating for two minutes, is 3.6%, and at determination of the forced temperature value - 0.8%.

Keywords:

Transformer, Thermal Subsystem, Energy Efficiency Thermal Load, Timing Diagrams of Temperatures,

PDF

___

[1] Yildiran, R., Atas, S., Kahraman, M. (2016). Design and performance analysis of a district heating system utilizing waste heat of a thermal power plant. Journal of Thermal Engineering, Vol. 2, No. 5, 940-954.
[2] Lienhard, John H. IV; Lienhard, John H. V (2008). A Heat Transfer Textbook (3rd ed.). Cambridge, Massachusetts: Phlogiston Press. ISBN 978-0-9713835-3-1.
[3] Incropera, F. et al. (2012). Fundamentals of heat and mass transfer (7th ed.). Wiley. 2012. 710 p. ISBN 978-0-470-64615-1.
[4] Maurya, R.S, Singh, S.(2017).Numerical investigation of isothermal flow around impingement plates in a shell and tube exchanger. Journal of Thermal Engineering, Vol. 3, No. 5. 1442-1452.
[5] Matukhno V., Baidak Yu., Tomlein P. (2016). Thermal subsystem of voltage distribution transformer. Refrigeration engineering and technology. Vol 52(6) URL: file:///C:/Users/User/Downloads/477-1152-1-PB (4).pdf