中南大学学报（自然科学版）2017，Vol.48Issue(10)：2572-2582,11.DOI:10.11817/j.issn.1672-7207.2017.10.003
喷淋层组合方式对大型脱硫塔内流动和热湿交换过程影响的数值模拟
Numerical simulation of impact of spraying layers scheme on gas-liquid two phases flow, heat and mass transfer in large scale desulphurization absorption tower
摘要
Abstract
The impact of different spraying layers scheme on gas-liquid two phases flow, heat and mass transfer in the large scale desulphurization tower with four spraying layers was investigated by numerical simulation. The Euler-Lagrange approach was adopted for the numerical calculation and the inter-exchange of momentum, mass and energy between the two phases was fully considered; the effect of instantaneous turbulent velocity fluctuations on the particle trajectories was also taken into account. Dependability of the simulation was validated via actual on-site data. The results show that large vortex region on the upper left of the tower inlet occurs when only the bottom spraying layer opens. But when only the top spraying layer or multiple layers operate, the gas-liquid contact is much greater and the above-mentioned non-uniformity in the flue gas distribution will not appear. The more spraying layers operate, the higher the pressure loss in the tower is. When only the top spraying layer operates, the pressure loss in the spraying zone is twice as much as that when only the bottom spraying layer is employed. In the absorption tower, the highest turbulence kinetic energy region is located in the spraying zone. With more spraying layers are put into operation, the region of high turbulence kinetic energy is enlarged and its value increases also. When multiple layers operate, area-weighted mean turbulence kinetic energy on the 2nd spraying layer reaches to maximum in the whole spaying zone, while the value on the top spraying layer is even lower than that on the 3rd layer. With regard to the heat and mass transfer in the desulphurization tower, no matter what kind of spraying layer scheme is adopted, the location corresponding to the biggest flue gas quenching rate and the location corresponding to the biggest water vapor generating rate are found coincident, which are located just above the upper plane of the flue gas inlet and beneath the bottom spraying layer. The simulation result also shows that the latent heat transferred through droplet evaporation and the sensible heat transferred via droplet heating up account for 87% and 13% of the total heat transfer capacity in the spraying tower respectively, which is in good agreement with the actual on-site water consumption data.关键词
湿法脱硫/喷淋层组合/气液两相流/热湿交换/数值模拟Key words
wet flue gas desulfurization/spraying layers scheme/gas-liquid two phases flow/heat and mass transfer/numerical simulation分类
能源科技引用本文复制引用
林瑜,陈德珍,尹丽洁..喷淋层组合方式对大型脱硫塔内流动和热湿交换过程影响的数值模拟[J].中南大学学报（自然科学版）,2017,48(10):2572-2582,11.基金项目
国家高技术研究发展计划(863计划)项目(2012AA063504)(Project(2012AA063504) supported by National High Technology Research and Development Program (863 Program) of China) （863计划）
