Discuss of Important Issues in Numerical Simulation for Natural Draft Counter Flow Cooling Tower

2012 ◽  
Vol 516-517 ◽  
pp. 267-270
Author(s):  
Li Song ◽  
Rui Tian ◽  
Song Li ◽  
Ya Hui Wang

natural draft counter flow cooling tower heat and mass transfer numerical simulation has been widely used to optimize the cooling tower design and to improve the thermal efficiency, but in published papers, a few important problems is not attracted attention, such as how does impact grid density to the calculation results; how does impact change of atmospheric density to the calculation results; drop diameter is an important parameter in numerical simulation, but it is not a exact experimental data, it is important to discuss how does impact drop size to the calculation results. This paper will explore and analyze these issues in the numerical simulation.

2012 ◽  
Vol 562-564 ◽  
pp. 1032-1035
Author(s):  
Shui Hua Zheng ◽  
Tai Jin ◽  
Jian Ren Fan

Based on the heat and mass transfer theory and characteristics of the FLUENT software, a three-dimensional numerical simulation platform composed by user defined functions had been developed to simulate the thermal performance in a natural draft wet cooling tower. This platform was used to study a typical hyperbolic natural draft wet cooling tower with different fill types. The variations of the flow and temperature field in the cooling tower caused by the two different methods of fill were investigated. It is found that the outlet water temperature will decrease due to the non-uniform fill depth. The non-uniform fill depth is beneficial to increasing the efficiency of the cooling tower.


2012 ◽  
Vol 614-615 ◽  
pp. 169-173
Author(s):  
Shui Hua Zheng ◽  
Tai Jin ◽  
Jian Ren Fan

Based on the heat and mass transfer theory and characteristics of the CFD software, a three-dimensional numerical simulation platform had been developed to study the thermal performance in a natural draft wet cooling tower. This platform was validated using the measured results of a running cooling tower. The flow and temperature field in the cooling tower were investigated. It is found that the water temperature and flow field can be correctly calculated using this platform. The cooling efficiency could be improved due to non-uniform fill and water distribution methods.


Akustika ◽  
2021 ◽  
pp. 100-106
Author(s):  
sergey Timushev ◽  
Alexey Yakovlev ◽  
Petr Moshkov

The problem of simulation the noise generated during the operation of the propeller is considered. Calculation methods are described and numerical simulation of the noise of a light aircraft propeller by the acoustic-vortex method is performed. The results of numerical modeling of the tonal components of the propeller noise when operating under static conditions are compared with experimental data and calculation results based on a semiempirical model.


2007 ◽  
Vol 19 (6) ◽  
pp. 762-768 ◽  
Author(s):  
Xiang-liang Yang ◽  
Feng-zhong Sun ◽  
Kai Wang ◽  
Yue-tao Shi ◽  
Nai-hua Wang

1990 ◽  
Vol 55 (2) ◽  
pp. 409-425 ◽  
Author(s):  
Helena Sovová

Six published correlations for Sauter diameter d32 in pulsed and reciprocating plate columns are compared with drop size measurements from seven different data sources. The correlation of Kumar and Hartland gives the best fit of data in the whole range of agitation rates. Also the semiempiric equations of Misek and of Boyadzhiev and Spassov are of general validity at higher agitation levels. A new semiempiric equation covering the whole range of agitation rates and describing experimental data with a standard deviation of 10% is presented.


Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6174
Author(s):  
Wei Yuan ◽  
Fengzhong Sun ◽  
Ruqing Liu ◽  
Xuehong Chen ◽  
Ying Li

The measures to reduce the impact of evaporation loss in a natural draft counter-flow wet cooling tower (NDWCT) have important implications for water conservation and emissions reduction. A mathematical model of evaporation loss in the NDWCT was established by using a modified Merkel method. The NDWCTs in the 300 MW and 600 MW power plant were taken as the research objects. Comparing experimental values with calculated values, the relative error was less than 3%. Then, the effect of air parameters on evaporation loss of NDWCT was analyzed. The results showed that, with the increase of dry bulb temperature, the evaporation heat dissipation and the evaporation loss decreased, while the rate of evaporation loss caused by unit temperature difference increased. The ambient temperature increased by 1 °C and the evaporation loss was reduced by nearly 26.65 t/h. When the relative air humidity increased, the evaporation heat dissipation and evaporation loss decreased, and the rate of evaporation loss caused by unit temperature difference decreased. When relative air humidity increased by 1%, the outlet water temperature rose by about 0.08 °C, and the evaporation loss decreased by about 5.63 t/h.


2018 ◽  
Vol 180 ◽  
pp. 02037
Author(s):  
Tomáš Hyhlík

The article deals with the development of incompressible ideal gas like model, which can be used as a part of mathematical model describing natural draft wet-cooling tower flow, heat and mass transfer. It is shown, based on the results of a complex mathematical model of natural draft wet-cooling tower flow, that behaviour of pressure, temperature and density is very similar to the case of hydrostatics of moist air, where heat and mass transfer in the fill zone must be taken into account. The behaviour inside the cooling tower is documented using density, pressure and temperature distributions. The proposed equation for the density is based on the same idea like the incompressible ideal gas model, which is only dependent on temperature, specific humidity and in this case on elevation. It is shown that normalized density difference of the density based on proposed model and density based on the nonsimplified model is in the order of 10-4. The classical incompressible ideal gas model, Boussinesq model and generalised Boussinesq model are also tested. These models show deviation in percentages.


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