Free Convection — Study of the Regular Thermal Mode in Different Layers at the Liquid Height

Authors

  • O. V. Vlasenko National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”
  • S. Yo. Tkachenko Vinnytsia National Technical University

DOI:

https://doi.org/10.31649/1997-9266-2023-166-1-29-34

Keywords:

cooling (heating) rate, regular thermal mode, thermocouple, excess temperature

Abstract

The rate of cooling (heating) of experimental liquids is investigated separately for five thermocouples located at different heights of the experimental probe.

Research is carried out on an experimental stand in the system "environment I — body II", where "environment I" is water, and "body II" is the investigated liquid medium in a thin metal cylindrical shell under conditions of free convection.

The rate of cooling (heating) is studied for test liquids: water, sunflower oil, distilled glycerin.

The analysis of cooling (heating) processes during free convection of non-stationary heat exchange is carried out. This paper presents research carried out on an experimental stand, which consists of an external metal vessel, containing the environment with a temperature of t1, an internal cylindrical metal vessel containing an experimental liquid medium with a temperature of t2. Accordingly, probes with five thermocouples are placed in hot and cold liquids to take temperature values at a fixed time

Non-stationary heat conduction processes occur during heating or cooling of bodies, substances, gaseous media and are accompanied by a change in enthalpy. Non-stationary and stationary processes of body heating due to the internal heat source, the electric heater, are considered in laboratory practice to determine the thermophysical properties of materials, bodies of substances and where cooling occurs due to the surrounding air.

The analysis of the excess temperature, carried out separately for each thermocouple, placed along the height of the cylindrical volume, shows that the linearity of the dependence Ln ϑ = f(τ) is preserved, while the influence of free convection on the value of m is manifested. The value of m depends on the height of the liquid layer in which the temperature is measured.

Author Biographies

O. V. Vlasenko, National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”

Researcher of the Chair of Thermal and Alternative Energy

S. Yo. Tkachenko, Vinnytsia National Technical University

Dr. Sc. (Eng.), Professor, Professor of the Chair of Power Engineering

References

Г. М. Кондратьев, Регулярный тепловой режим. М.: Государственное издательство технико-теоретической литературы, 1954, 408 с.

В. А. Осипова, Экспериментальное исследование процессов теплообмена, М. П. Вукалович, Ред.. М-Л : Энергия, 1964.

В. П. Исаченко, В. А. Осипова, и А. С. Сукомел, Теплопередача, учеб. для вузов, изд. 3-е, перераб. и доп. М.: Энергия, 1975, 488 с.

С. Й. Ткаченко, О. В. Власенко, і В. О. Задоян, «Темп охолодження (нагрівання) соняшникової олії в різних шарах по висоті циліндричного об’єму,» у Тези наук.-техн. конф. підрозділів Вінницького національного технічного університету (НТКП ВНТУ). Факультет будівництва, теплоенергетики та газопостачання, 2021.

С. Й. Ткаченко, і О. В. Власенко, «Темп охолодження (нагрівання) рідинних середовищ з різними значеннями коефіцієнтів теплопровідності і теплоємності,» у Тези наук.-техн. конф. підрозділів Вінницького національного технічного університету (НТКП ВНТУ). Факультет будівництва, теплоенергетики та газопостачання, 2021.

С. Й. Ткаченко, і Н. В. Пішеніна, Нові методи визначення інтенсивності теплообміну в системах переробки органічних відходів, моногр. Вінниця, Україна: ВНТУ, 2017, 148 с.

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Published

2023-02-28

How to Cite

[1]
O. V. . Vlasenko and S. Y. Tkachenko, “Free Convection — Study of the Regular Thermal Mode in Different Layers at the Liquid Height”, Вісник ВПІ, no. 1, pp. 29–34, Feb. 2023.

Issue

No. 1 (2023)

Section

ENERGY GENERATION, ELECTRIC ENGINEERING AND ELECTROMECHANICS

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