Influence of the geometrical characteristics of the surface with spherical wells on heat exchange of water and air

Dubrovskyi V.V., Cand. Sci. (Eng.), Senior Researcher, Pidvysotskyi O.M., Cand. Sci. (Eng.), Senior Researcher
Institute of General Energy of the National Academy of Sciences of Ukraine, 172 Antonovycha St., Kyiv, 03680, Ukraine
Language: Ukrainian
Source: Problemy zahal`noi enerhetyky - The Problems of General Energy, 2015, 3(42):50-56
Section: Study and optimization of the technological objects and systems of the energy sector
UDC: 536.24
Received: 23.09.2015
Published: 05.11.2015
Abstract: One of the ways of increasing the cooling capacity of film-type cooling towers is the use of sprinklers in the form of profiled surfaces with spherical dimples, which provide a high efficiency of heat transfer from water to air. The search for new shapes of sprinkler surfaces, which can enhance the efficiency of the operation of cooling towers, is an important scientific and technical problem.
The aim of the present work is to advance the geometric characteristics of sprinkler surfaces, namely, to study experimentally the influence of the depth of spherical dimples and the density of their position on the surface on heat transfer from water to air as well as to propose efficient profiled sprinkler surfaces for film-type cooling towers.
Experiments were carried out under different conditions of interaction between the phases water – air at transverse blow of the liquid film by air having different velocities, and also in quiescent air.
We found profiled surface that takes into account the assemblage of such factors as the sizes of spherical dimples, their depth, and distance between neighboring dimples and, hence provides the most efficient heat transfer. Such surface can be used as a sprinkler for film-type cooling towers.
Key words: film-type cooling tower, profiled surface of sprinklers, heat transfer, cooling degree.
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