直接空冷机组雾化增湿系统的数值研究

Numerical Study on Spray Humidification System Used in the Direct Air-cooled Unit

为研究雾化增湿降温法在大型电站直接空冷机组中应用的可行性,基于标准湍流模型和离散相模型,采用计算流体动力学技术对雾化增湿系统进行了三维数值模拟,讨论了雾滴的雾化过程和雾滴在空冷单元内热湿交换效果。结果表明,含有雾化增湿装置的空冷单元,空冷散热器入口和出口的空气温度都有明显的降低。直接空冷机组应用雾化增湿系统使空冷散热器的散热效率和真空度得到明显提高,不仅显著提高机组的经济性,而且有利于机组的安全运行,具有较高的推广应用价值。

To study the feasibility of the spray humidification applied in direct air-cooled unit of large power plant, using computational fluid dynamics （CFD） technique the spray humidification system had been 3-D numerically simulated, based on standard turbulence model and discrete phase model （DPM）. The process of atomization about the droplet and the exchange effect of heat and humidity in air-cooled cell had been discussed in detail. The results indicate that the air temperature of air-cooled radiator＇s inlet and outlet declines remarkably in the air-cooled cell which contains spray humidification device. In the direct air-cooled unit applying spray humidification system, the efficiency of heat exchange and the vacuum in the air-cooled radiator increased obviously. This method not only can significantly enhance the economical efficiency of the unit, but also keep the unit operating safely, which is worth widely popularizing and applying.