Analysis of the occurrence of natural convection in a bed of bars in vertical temperature gradient conditions

Archives of Thermodynamics

Rafa? Wyczó?kowskiCzestochowa University of Technology, Faculty of Process and Materials Engineering and Applied Physics, Department of Industrial Furnaces and Environmental Protection al. Armii Krajowej 19, 42-200 Cz?stochowa, PolandOther articles by this author:De Gruyter OnlineGoogle Scholar¹  Dorota Musia?Corresponding authorCzestochowa University of Technology, Faculty of Process and Materials Engineering and Applied Physics, Department of Industrial Furnaces and Environmental Protection al. Armii Krajowej 19, 42-200 Cz?stochowa, PolandEmailOther articles by this author:De Gruyter OnlineGoogle Scholar¹ 

[1] Czestochowa University of Technology, Faculty of Process and Materials Engineering and Applied Physics, Department of Industrial Furnaces and Environmental Protection al. Armii Krajowej 19, 42-200 Cz?stochowa, Poland

关键词: Keywords: Natural convection;    Bed of bars;    Porous material;   

DOI  :  10.2478/aoter-2013-0005

学科分类：能源（综合）

来源: Polska Akademia Nauk * Oddzial w Gdansku, Instytut Maszyn Przeplywowych / Polish Academy of Sciences, Institute of Fluid-Flow Machinery

【 摘 要 】

The reason for undertaking this study was to determine the possible involvement of natural convection in the global heat transfer, that occurs in the heated steel rods bed. This problem is related to the setting of the effective thermal conductivity of the bars bed. This value is one of the boundary conditions for heating modeling of steel rods bundles during heat treatment. The aim of this study was to determine for which geometry of the bed bars, there will be no free convection. To analyze the problem the Rayleigh criterion was used. It was assumed that for the value of the number Ra < 1700 convection in the bed bars does not occur. For analysis, the results of measurements of the temperature distribution in the unidirectionally heated beds of bars were used. It has been shown, that for obtained, during the test, differences of temperature between the surfaces of adjacent rods, convection can occur only when the diameter of the rod exceeds 18 mm.

【 授权许可】

Unknown