Computational Analysis of Closed Wet Cooling Towers

Zhu, Dongsheng; Zheng, Wandong; Zhou, Guo‐Yan; Wu, Jiangbo; Shi, Yun-Yi

doi:10.1080/10407782.2013.733270

Cited by 9 publications

(2 citation statements)

References 17 publications

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“…So, in this research, the macro heat exchanger model for the finned tube bundles are adopted, so as to specifically investigate the thermo-flow characteristics of the air-cooled sectors and cooling deltas with the numerical method, which differs from the CFD method with the previous radiator model. It is worth noting that the natural draft dry cooling system (NDDCS) possesses a complicated large-scale structure, like the closed wet cooling tower (CWCT), and for the large-scale CWCT, Zhu et al [18] proposed a CFD model and compared the numerical and experimental results, which shows good agreement. For the large-scale air-cooled heat exchanger model of the NDDCS in this research, the simulation results with the two numerical models were also compared with the experimental results, which showed a better prediction of the thermo-flow performances of NDDCS using the proposed macro heat exchanger model, since the thermo-hydraulic characteristics of the heat exchanger bundle for airside was coupled with waterside.…”

Section: Introductionmentioning

confidence: 99%

Influencing Mechanisms of a Crosswind on the Thermo-Hydraulic Characteristics of a Large-Scale Air-Cooled Heat Exchanger

et al. 2019

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For the large scale air-cooled heat exchanger of a natural draft dry cooling system (NDDCS) in power plants, its thermo-flow characteristics are basically dominated by crosswinds. Unfortunately however, the detailed mechanisms of the crosswind effects have yet to be fully uncovered. Therefore, in this research, the local flow and heat transfer performances of the cooling deltas, which are also termed as the fundamental cells of the large-scale air-cooled heat exchanger, are specifically investigated with full consideration for the cell structure and the water-side temperature distribution at various wind speeds. A 3D CFD method with a realizable k-ε turbulence model, heat exchanger model, and porous media model is developed, and the accuracy and credibility of the numerical model are experimentally validated. With the numerical simulation, the overall 3D outlet air temperature of the large-scale air-cooled heat exchanger, and the corresponding local air velocity and temperature fields of the cooling deltas are qualitatively analyzed. Furthermore, the air-mass flow rate and heat rejection are also quantitatively studied at both the global and local views. The results depict that with an increase in the wind speed, the air mass flow rate and heat rejection will increase greatly for the frontal deltas; however, they will drop dramatically for the middle-front deltas. As for the middle- as well as the middle-rear deltas, the thermo-flow performances vary markedly at various wind speeds, which behave in the most deteriorated manner at a wind speed of 12 m/s. The rear deltas show the best thermo-flow performances at a wind speed of 12 m/s, but the worst at 16 m/s. A detailed analysis of the variable fields for each cooling delta may contribute to the performance improvement of the large-scale air-cooled heat exchanger of NDDCS.

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Section: Introductionmentioning

confidence: 99%

Influencing Mechanisms of a Crosswind on the Thermo-Hydraulic Characteristics of a Large-Scale Air-Cooled Heat Exchanger

et al. 2019

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“…Heat transfer and fluid flow analysis over tube banks is of great importance in various design applications such as cooling towers [1], boilers [2], various heat exchangers [3][4][5], chemical filtration [6], and nuclear reactors [7]. Heat exchanger design depends on such parameters as the number of pipes of various lengths and diameters, geometric dimensions, arrangement of tubes, and fluids that carry heat [8,9].…”

Section: Introductionmentioning

confidence: 99%

A Hybrid Finite-Element/Finite-Difference Scheme for Solving the 3-D Energy Equation in Transient Nonisothermal Fluid Flow over a Staggered Tube Bank

Alavi

Safaei

Mahian

et al. 2015

Numerical Heat Transfer, Part B: Fundamentals

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This article presents a hybrid finite-element=finite-difference approach. The approach solves the 3-D unsteady energy equation in nonisothermal fluid flow over a staggered tube bank with five tubes in the flow direction. The investigation used Reynolds numbers of 100 and 300, Prandtl number of 0.7, and pitch-to-diameter ratio of 1.5. An equilateral triangle (ET) tube pattern is considered for the staggered tube bank. The proposed hybrid method employs a 2-D Taylor-Galerkin finite-element method, and the energy equation perpendicular to the tube axis is discretized. On the other hand, the finitedifference technique discretizes the derivatives toward the tube axis. Weighting the 3-D, transient, convection-diffusion equation for a cube verifies the numerical results. The L 2 norm of the error between numerical and exact solutions is also presented for three different hybrid meshes. A grid independence study for the energy equation preceded the final mesh. The outcome is found to be in acceptable concurrence with those from the previous studies. After the temperature field is attained, the local Nusselt number is computed for the tubes in the bundle at different times. The isotherms are also obtained at different times until a steady-state solution is reached. The numerical results converge to the exact results through refining the mesh. The implemented hybrid scheme requires less computation time compared with the conventional 3-D finite-element method, requiring less program coding.

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Heat transfer enhancement for the coil zone of closed wet cooling towers through field synergy analysis

Xie

Zhang

et al. 2018

13th International Symposium on Process Systems Engineering (PSE 2018)

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Computational Analysis of Closed Wet Cooling Towers

Cited by 9 publications

References 17 publications

Influencing Mechanisms of a Crosswind on the Thermo-Hydraulic Characteristics of a Large-Scale Air-Cooled Heat Exchanger

Influencing Mechanisms of a Crosswind on the Thermo-Hydraulic Characteristics of a Large-Scale Air-Cooled Heat Exchanger

A Hybrid Finite-Element/Finite-Difference Scheme for Solving the 3-D Energy Equation in Transient Nonisothermal Fluid Flow over a Staggered Tube Bank

Heat transfer enhancement for the coil zone of closed wet cooling towers through field synergy analysis

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