Enhancement of cooling tower performance by manipulation of rain zone drop size
Date
1995-03
Authors
Oosthuizen, Henry Randolph
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
AFRIKAANSE OPSOMMING: Die moontlikheid om die warmteoordrag in die reensone van 'n natuurlike trek nat koeltoring
te vcrbeter deur die gemiddelde druppel diameter van die sproei te verminder is ondersoek.
Eksperimentele wcrk was daarop gerig om tipiese druppelgrootte verspreidings onder
druppakking te bepaal, asook die verkryging van werklike verrigtings-data vir verskiJlende
pakking en reensone kombinasies in 'n koeltoring toetsfasiliteit. 'n Fotografiese metode wat
gebruik maak van beeldverwerkingstegniekc is ontwikkel om die druppelgrootte verspreidings
wat in die )meltoring toetsfasiliteit gevind word te bepaal. 'n Rekenaar simulasieprogram wat
ontwikkel is deur Dreyer [940Rl] is verder gebruik om reensone verrigtingsdata
( oordragskarakteristieke en druppelgrootte verspreidings) teoreties te vcorspel, vir vergelyking
met en evalusie van die eksperimentele resultate.
Dit is bewys dat die plasing van 'n laag spatroosters reg onder druppakking die gerniddelde
druppeldiameter in die reensone verrninder het, wat gelei het tot 'n ooreenstemmende toename
in oordragskarakteristiek. Met die gebruik van 'n rekenaar simulasie program is bereken dat
hierdie opstelling die termiese kapasiteit van 'n koeltoring met tot 5 % kan verbeter.
ENGLISH ABSTRACT: The possibility of improving the heat transfer in the rain zone of large natural draft wet cooling towers, by decreasing the mean drop diameter in this region, has been investigated. Experimental studies were aimed at determining typical drop size distributions under trickle packs and obtaining actual performance data for packing and rain zone combinations in a cooling tower test facility. A photography-based method, which utilizes image processing techniques, was develo!Jed t() determine the drop size distributions found in the test facility. A computer simulation program developed by Dreyer [94DRI] was used to theoretically predict rain zone performance data (i.e., transfer coefficients and drop size distribution data) for comparison with and evaluation of the experimental data. I: was found that by placing a layer of splash grids beneath a trickle pack the mean drop diameter in the rain zone was decreased, resulting in corresponding increases in transfer characteristic. Using a computer simulation program it was calculated that this arrangement could increase the thermal capacity of a large natural draft cooling tower by up to 5 %.
ENGLISH ABSTRACT: The possibility of improving the heat transfer in the rain zone of large natural draft wet cooling towers, by decreasing the mean drop diameter in this region, has been investigated. Experimental studies were aimed at determining typical drop size distributions under trickle packs and obtaining actual performance data for packing and rain zone combinations in a cooling tower test facility. A photography-based method, which utilizes image processing techniques, was develo!Jed t() determine the drop size distributions found in the test facility. A computer simulation program developed by Dreyer [94DRI] was used to theoretically predict rain zone performance data (i.e., transfer coefficients and drop size distribution data) for comparison with and evaluation of the experimental data. I: was found that by placing a layer of splash grids beneath a trickle pack the mean drop diameter in the rain zone was decreased, resulting in corresponding increases in transfer characteristic. Using a computer simulation program it was calculated that this arrangement could increase the thermal capacity of a large natural draft cooling tower by up to 5 %.
Description
Thesis (MEng)--University of Stellenbosch, 1995.
Keywords
Cooling towers -- Computer simulation, Drops -- Computer simulation, Image processing, Dissertations -- Mechanical engineering, Theses -- Mechanical engineering