Determination of natural draft wet-cooling tower loss coefficient

2018 ◽  
Author(s):  
Tomáš Hyhlík
Keyword(s):  
Cooling Tower ◽  
Loss Coefficient ◽  
Natural Draft

Computational Fluid Dynamics Analysis of Cooling Tower Inlets

2011 ◽  
Vol 133 (8) ◽  
Author(s):  
H. C. R. Reuter ◽  
D. G. Kröger
Keyword(s):  
Cooling Tower ◽  
Flow Patterns ◽  
Full Scale ◽  
Loss Coefficient ◽  
Cooling Towers ◽  
Cfd Model ◽  
Shell Wall ◽  
Natural Draft ◽  
Flow Losses ◽  
Loss Coefficients

Cooling tower inlet losses are the flow losses or viscous dissipation of mechanical energy affected directly by the cooling tower inlet design, which according to the counterflow natural draft wet-cooling tower performance analysis example given in Kröger (Kröger, 2004, Air-Cooled Heat Exchangers and Cooling Towers: Thermal-Flow Performance Evaluation, Pennwell Corp., Tulsa, OK), can be more than 20% of the total cooling tower flow losses. Flow separation at the lower edge of the shell results in a vena contracta with a distorted inlet velocity distribution that causes a reduction in effective fill or heat exchanger flow area. In this paper, a two-dimensional (axi-symmetric) computational fluid dynamic (CFD) model is developed using the commercial CFD code ANSYS FLUENT, to simulate the flow patterns, loss coefficients and effective flow diameter of circular natural draft cooling tower inlets under windless conditions. The CFD results are compared with axial velocity profile data, tower inlet loss coefficients and effective diameters determined experimentally by Terblanche (Terblanche, 1993, “Inlaatverliese by Koeltorings,” M. Sc. Eng. thesis, Stellenbosch University, Stellenbosch, South Africa) on a cylindrical scale sector model as well as applicable empirical relations found in Kröger, determined using the same experimental apparatus as Terblanche. The validated CFD model is used to investigate the effects of Reynolds number, shell-wall thickness, shell wall inclination angle, fill loss coefficient, fill type, inlet diameter to inlet height ratio and inlet geometry on the flow patterns, inlet loss coefficient and effective diameter of full-scale cooling towers. Ultimately, simple correlations are proposed for determining the cooling tower inlet loss coefficient and inlet effective flow diameter ratio of full-scale cooling towers excluding the effect of rain zones and the structural supports around the cooling tower entrance.

Numerical investigation of swirl effects on a short natural draft dry cooling tower under windless and crosswind conditions

2021 ◽  
Vol 188 ◽  
pp. 116628 ◽  
Author(s):  
Yuchen Dai ◽  
Yuanshen Lu ◽  
Alexander Y. Klimenko ◽  
Ying Wang ◽  
Kamel Hooman
Keyword(s):  
Numerical Investigation ◽  
Cooling Tower ◽  
Natural Draft ◽  
Dry Cooling Tower ◽  
Dry Cooling

Improving Natural Draft Cooling Tower Performance With Heat Injection

2002 ◽  
Author(s):  
Eugene Grindle ◽  
John Cooper ◽  
Roger Lawson
Keyword(s):  
Water Temperature ◽  
Computer Model ◽  
Cooling Tower ◽  
Ambient Air ◽  
Combined Cycle ◽  
Steam Boiler ◽  
Natural Draft ◽  
Circulating Water ◽  
Vapor Stream ◽  
Heat Injection

This paper presents an assessment of heat injection as a means of improving natural draft cooling tower performance. The concept involves injecting heat into the cooling tower exit air/vapor stream immediately above the drift eliminators in order to increase the difference between the density of the exit air/vapor stream and the ambient air. The density difference between the air/vapor in the cooling tower stack and the ambient air is the engine that drives airflow through the cooling tower. The enhancement of the airflow through the cooling tower (the natural draft) results in more evaporation and thus lowers the circulating water temperature. Because the heat is injected above the drift eliminators, it does not heat the circulating water. To evaluate the cooling tower performance improvement as a function of heat injection rate, a thermal/aerodynamic computer model of Entergy’s White Bluff 1 & 2 and Independence 1 & 2 (approximately 840 MW each) natural draft cooling towers was developed. The computer model demonstrated that very substantial reductions in cold water temperature (up to 7°F) are obtainable by the injection of heat. This paper also discusses a number of possible heat sources. Sources of heat covered include extraction steam, auxiliary steam, boiler blow-down, and waste heat from a combustion turbine. The latter source of heat would create a combined cycle unit with the combination taking place in the condensing part of the cycle (bottom of the cycle) instead of the steam portion of the cycle (top of the cycle).

scholarly journals Wind-break walls with optimized setting angles for natural draft dry cooling tower with vertical radiators

2017 ◽  
Vol 112 ◽  
pp. 326-339 ◽  
Author(s):  
Huan Ma ◽  
Fengqi Si ◽  
Yu Kong ◽  
Kangping Zhu ◽  
Wensheng Yan
Keyword(s):  
Cooling Tower ◽  
Natural Draft ◽  
Dry Cooling Tower ◽  
Dry Cooling

Ventilation enhancement for a natural draft dry cooling tower in crosswind via windbox installation

2018 ◽  
Vol 137 ◽  
pp. 93-100 ◽  
Author(s):  
Weiliang Wang ◽  
Hai Zhang ◽  
Junfu Lyu ◽  
Qing Liu ◽  
Guangxi Yue ◽  
...  
Keyword(s):  
Cooling Tower ◽  
Natural Draft ◽  
Dry Cooling Tower ◽  
Dry Cooling
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