大型烟气脱硫塔的流体动力学模拟及优化设计

Flow simulation for large scale FGD scrubbers and optimization design

对大型烟气喷淋脱硫塔进行合理简化,并结合浆液液滴随机生成模型.采用基于kε的湍流方程和基于雷诺平均的NavierStocks控制方程,对喷淋脱硫塔进行了空塔和喷淋状态下的热态流场计算.计算结果表明脱硫塔内入口处流场变化最剧烈,压降损失最大,因此对入口处进行改造可减小压降损失;喷淋浆液液滴对烟气流场具有强烈的整流作用,可以使空塔中的烟气漩涡强度和规模减小.根据计算结果对脱硫塔的来流烟道加以改造,并对改造后的脱硫塔进行了流场计算,计算结果表明,改造后烟气因塔内结构而产生的漩涡已明显减小,流场分布更为合理.

A numerical simulation for large scale spray scrubber flue gas desulfurization (FGD) tower was conducted based on Renold based Navier-Stocks and k-Ε turbulent equation. Stochastic model was used to imitate the initial condition of the slurry droplets. Both under spray and without spray conditions were simulated. The calculation results show that the flue gas flow field changes fast in the entrance of the tower and maximum pressure loss takes place in this stage. Therefore improvements on the tower entrance structure can achieve a reduction of the pressure loss of the whole tower. The comparison results imply that the moving slurry droplets bring huge influence on the flue gas flow by cutting down the scale of the eddy of the flue gas. An amendment of the entrance structure of the tower was also simulated and results show that the eddy resulted from the structure of the entrance is decreased.