Порівняльний аналіз вертикальних поверхонь з різними типами оребрення в умовах природної конвекції
Abstract
COMPARATIVE ANALYSIS OF VERTICAL SURFACES WITH VARIOUS TYPES OF WATER IN CONDITIONS OF NATURAL CONVECTION
V. Gorobets
Vertical surfaces with different types of fins in the conditions of natural convection have been widely used in various fields in the development of heat-exchange equipment. Such surfaces are used for cooling electronic and computer equipment, in heating devices, in heat exchangers for cooling transformers, and so on. At the same time, an important factor is the size and mass of such devices, which to a large extent depends on the type and geometry of the fineness used in it. The most common and investigated is the flat-parallel continuous fins. However, this type of sharpening has the deteriorated characteristics of heat transfer for surfaces with large vertical dimensions due to the heating of the cooling coolant in the upper part of the razor. In order to increase the thermal efficiency of heat transfer surfaces, a discrete fins were proposed, the geometry of which involves the use of fins of small size, arranged in chess.
The purpose of research - perform a comparative analysis of the heat transfer of vertical surfaces with a fineness of different types under free convection conditions. A comparative analysis of the heat exchange of continuous vertical, discrete vertical and sloping fines under free convection conditions is carried out. It is shown that the use of discrete sharpening significantly intensifies the processes of heat exchange on vertical surfaces. The comparison of the discrete vertical and sloping fines indicates the advantage of the first type of sharpening for surfaces with small vertical dimensions and deterioration of the heat transfer conditions compared to the second type of sharpening for surfaces of a large length.
As a result, the following conclusions can be drawn:
1) A comparative analysis of the thermal efficiency of surfaces with different types of fines - a continuous flat-parallel sharpening, a discrete fineness with a chess arrangement, an inclined discrete fineness of the type of "Christmas tree".
2) It is shown that the sampling of the fineness with its chess arrangement allows to increase the thermal efficiency of the surface in 1,3-2,5 times.
3) Discrete tongue-like "fir tree" has advantages over chess discrete fines for surfaces with large vertical dimensions. The value of the drained heat flux for such surfaces in 1,6-1,8 times increases compared with the plane-parallel fineness.
References
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