Simulation Study on Influence of Installation Height of Mist Eliminator on Liquid Holdup of Flue Gas in Desulfurization Tower

doi:10.12096/j.2096-4528.pgt.20039

Abstract

Abstract:

During the operation of a power plant, there is a periodic phenomenon of mist eliminator resistance rising and scaling, which results in the partial collapse of the mist eliminator. In order to solve this problem, the gas-liquid two-phase flow field in the desulfurization tower was simulated by numerical simulation method, and the condition of flue gas carrying spray droplets at the bottom of the mist eliminator was further studied, as affected by the varying heights (2.0-3.5m) from the top spray layer center to the bottom and the different misting drop sizes (1500-2500μm) of the particular nozzles. The results show that with the increase of the distance from the mist eliminator to the spray layer, the mass concentration of spray drops decreases, and the flow field inside the desulphurization tower becomes more uniform. The quantitative data were obtained by numerical simulation, which can provide a diagnostic thought and optimization basis for domestic coal-fired power plants with similar phenomena such as mist eliminator blocking and collapsing.

Key words: desulphurization tower, flow field simulation, mist eliminator, spray layer

CLC Number:

TK09

Shuangping ZHANG, Weixiong CHEN, Xibu JIA, Yuan YUAN. Simulation Study on Influence of Installation Height of Mist Eliminator on Liquid Holdup of Flue Gas in Desulfurization Tower[J]. Power Generation Technology, 2021, 42(2): 247-253.

Figures/Tables 10

Tab. 1 Relevant calculation parameters of numerical simulation for desulphurization tower

参数	数值
喷淋浆液温度/℃	50
喷淋层数	3
烟气进口流速/(m/s)	15.95
烟气进口温度/℃	100
烟气出口压力/Pa	50

Fig.1 Desulphurization tower structure

Fig.2 Mesh generation and irrelevance validation

Fig.3 Mesh generation of calculation zone for desulphurization tower

Fig.4 Flat oval droplet

Fig.5 Relationship between droplet mass concentration and flue gas velocity in mist eliminator

Fig.6 Relationship between droplet limit size and flue gas velocity in mist eliminator

Fig.7 Critical velocity of spraying droplet size under different models

Fig.8 Distribution graphs of droplet mass concentration along the bottom of mist eliminator at different heights

Fig.9 Variation curve of droplet mass concentration at the bottom edge of mist eliminator

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