High-efficiency heat-exchange surface for film processes

Dubrovskyi V.V., Cand. Sci. (Eng.), Senior Researcher
Institute of General Energy of the National Academy of Sciences of Ukraine, 172 Antonovycha str., Kyiv, 03150, Ukraine
Language: Ukrainian
Source: Problemy zahal`noi enerhetyky - The Problems of General Energy, 2017, 3(50):68-73
Section: Study and optimization of the technological objects and systems of the energy sector
UDC: 536.24
Received: 12.09.2017
Abstract: We have proposed to introduce a new profiled surface with spherical dimples, which is characterized by a high-efficiency heat transfer from a flowing down liquid film to surrounding air. Such a surface can be used for heat exchangers of contact type. The characteristics of such surfaces are based on our experimental studies of the heat exchange between water and air phases on surfaces with dimples of different sizes. We have found the optimal geometric characteristics of surface where the most intense heat transfer from a liquid film to air is achieved. We have derived generalized dependences that enable one to calculate the effective coefficient of heat transfer taking into account the total effect of heat exchange of a water film to air due to convection and liquid evaporation.
We present an example of the use of heat-exchange surface as a sprinkler for film cooling towers, a list of the drawbacks accompanying typical energy cooling towers, and a series of advantages of a profiled sprinkler as compared with a smooth one as to their cooling efficiency.
Keywords: profiled surface, heat transfer, film processes.
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