自然通风湿式冷却塔加装斜面挡风墙的数值研究

Numerical Study on Natural Draft Wet Cooling Tower Fixed with Tilted Windbreak Walls

以火电厂冷却塔相关理论为基础,借助Fluent模拟软件,建立了某1 000MW机组湿式自然通风冷却塔的三维传热传质模型,采用离散相模型分析了循环冷却水的流动与热力特性,模拟了冷却塔内部气水流场及其传热过程.结果表明:在雨区加装斜面挡风墙可使外界部分空气直接进入中心区域与冷却水发生传热,改善了冷却塔的传热效率;且当加装与竖直方向呈30°夹角的斜面挡风墙附加外围导流板时,出塔水温最低,比加装十字挡风墙的冷却塔出塔水温降低了0.96K.

Based on relevant theories of wet cooling tower, a 3D heat and mass transfer model was estab- lished for the natural draft cooling tower of a 1 000 MW power unit using Fluent software, with which the flow and thermal characteristics of circulating cooling water were analyzed on the basis of discrete phase model, while the air/water flow field and air-water heat transfer in the tower simulated. Results show that by installing tilted windbreak walls in the rain zone, a part of outer air may directly enter into the center area to exchange heat with cooling water there, and thus the heat-transfer efficiency is raised. Minimum outlet water temperature may be obtained when the angle is 30 between titled windbreak wall and the verti- cal plane, in the case that baffle plates are fixed, under which condition the outlet water temperature will be 0.96 K lower than the case that cross windbreak wall is mounted.