Можливості підвищення ефективності роботи плівкових градирень при використанні зрошувачів з профільованою поверхнею

• Date: 2011
• Main Authors: Dubrovskyi V.V., Pidvysotskyi O.M.
• Format: Article
• Language: Ukrainian
• Published: General Energy Institute of the National Academy of Sciences of Ukraine 2011
• Subjects: інтенсифікація теплообміну; профільована поверхня; сферичні лунки; градирня.
• Online Access: https://systemre.org/index.php/journal/article/view/408
• Journal Title: System Research in Energy

The aim of the present work is to analyze the possibilities and ways of enhancing the efficiency of water cooling in film cooling towers by means of the use of sprinklers with profiled surface.Our experimental investigations of heat transfer between water and surrounding air, performed earlier, show that the application of spherical dimples on the sprinkler sheets increases substantially the heat transfer intensity and, correspondingly, the degree of water cooling. Depending on the sizes of spherical dimples on the surface, where water flows down, and hydrodynamic conditions, the heat transfer coefficient becomes 1,5 – 3 times greater as compared with a smooth surface.Based on the obtained empirical formula for dimensionless heat transfer coefficient (Nusselt number), we have analyzed the influence of different factors on the intensification of heat transfer between a water film flowing down and surrounding air. We give some examples of calculations of the degree of water cooling for its flow along a profiled surface with spherical dimples, which guarantees the best results as to the cooling intensity.These data enable us to conclude that the degree of cooling of a technological liquid in film flow along a profiled surface depends most strongly (as compared with a smooth surface) on the relative velocity of interacting phases.Our calculations show that, depending on the requirements to the construction of a cooling tower, the same results on the degree of water cooling can be obtained by different combinations of determining parameters. The choice of variant of the solutions is determined, in the end, by economic considerations.