Open AccessModeling of a Spray Assisted Natural Draft Cooling Tower
Author(s) -
O.K. Kaunde
Publication year - 2008
Publication title -
tanzania journal of engineering and technology/tanzania journal of engeering and technology
Language(s) - English
Resource type - Journals
eISSN - 1821-536X
pISSN - 2619-8789
DOI - 10.52339/tjet.v31i1.423
Subject(s) - cooling tower , heat transfer , mechanics , tower , injector , environmental science , mass transfer , entrainment (biomusicology) , volumetric flow rate , hull , nuclear engineering , meteorology , materials science , water cooling , engineering , marine engineering , mechanical engineering , physics , structural engineering , rhythm , acoustics
Cooling towers are one of the largest heat and mass transfer devices that are in common use. A novel type of cooling tower has been proposed in which air flow rate into the tower is drawn by ejector action of sprays instead of fans as is done in conventional mechanical forced or induced draft cooling towers. This novel design offers the potential of savingthe energy cost for driving the fan. The paper presents mathematical models for momentum transfer which is the driving force causing the entrainment of air. Also the heat transfer model for co-current flow of liquid and gas in the tower has been presented. The liquid to gas ratio tend to decrease as liquid rate increases. The ratio attained in the experimentallaboratory tower was 3.3, correspondingly the Momentum transfer efficiency for the tower was 60% and was the highest. Experiments for cooling water initially at 45 o C to final water temperature 27 o C showed that the cooling tower efficiency was 54% and number of transfer unit 0.8.