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A critical evaluation and refinement of the performance prediction of wet-cooling towersKloppers, Johannes Christiaan 12 1900 (has links)
Thesis (PhD (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2003. / The thermal performance prediction of wet-cooling towers is critically analyzed and refined. Natural draft
counterflow towers and mechanical draft counterflow and crossflow towers are considered. The Merkel,
Poppe and e-NTU heat and mass transfer methods of analysis are derived from first principles, as these
methods form the cornerstone of wet-cooling tower performance evaluation. The critical differences
between these methods, when applied to fill performance analyses and cooling tower performance
evaluations, are highlighted. The reasons for these differences are discussed with the aid of psychrometric
charts. A new extended empirical relation for the loss coefficient of fills is proposed where the viscous
and form drag effects are accounted for as well as the buoyancy, momentum and fill height effects. The
empirical equation for the transfer characteristic of fills is extended to include the effects of fill height and
the inlet water temperature. Empirical equations to predict the temperature inversion profile, height of the
temperature inversion and the height from which air is drawn into the cooling tower are developed. The
influence of temperature and humidity inversions on the performance of wet-cooling towers is
subsequently investigated. A comprehensive analytical computer program is developed to predict and
optimize the performance of wet-cooling towers. Computer programs are also developed to generate
cooling tower performance curves, analyze fill performance test data and plot psychrometric charts.
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Návrh chladícího okruhu pro odvod tepla z kondenzátoru parní turbíny / Design of a cooling circuit for heat removal from a steam turbine condenserSusna, David January 2018 (has links)
This thesis deals with the problems of wounding of low potential transferred from steam turbine condenser. First, in the theoretical part variations of steam condenser design are described. Then there is a description of variations of cooling cycles and possibilities of their operation range. In second part of the thesis there are two common cooler options chosen. Those are wet cooling tower with natural draft and dry chiller with forced draft. Two types of cooling liquid are chosen to be used for dry cooling. These are water and the other one is 50 % mixture of water and propylene glycol. Based on the calculation results of both cooling cycle variations appropriate pumps are chosen, fan for forced convection respectively. Parts of the thesis are also projection drawings for both calculated variations.
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