加装导流网以改善横向风对直接空冷凝汽器的影响

Effects of Using Wind Guiding Nets to Improve Prevailing Ambient Wind on Direct Air-cooled Condensers

横向风是造成直接空冷凝汽器迎风侧空冷单元风机进气量降低甚至空气倒灌的主要原因,解决横向风对直接空冷凝汽器的不良影响具有重要意义。该文提出了一种改善横向风对直接空冷凝汽器不良影响的新方法,即在空冷凝汽器的迎风侧挡风墙下方加装导流网。以某1000MW直接空冷凝汽器的一组典型单元为研究对象,建立几何模型和数学模型,通过计算流体力学(computational fluid dynamics,CFD)模拟分析,阐明了加装导流网以提高风机入口进气流量的机制。研究表明:加装导流网可以有效地减弱空冷凝汽器横向风迎风侧上游单元风机入口的负压,增大进气量,同时避免了加装导流板对下游风机的不利影响。

Prevailing ambient wind is the main reason that causes inlet flow rate decreasing and air flowing backward to the air-cooled condenser fans upward to the wind, so it is very important to improve the detrimental effect of prevailing ambient wind on direct air-cooled condensers （DACC）. On the purpose of this a new method to install a wind guiding net under the windwall was presented. On the bases of geometrically and mathematically modeling to a set of typical units of a 1000MW air-cooled condenser with the wind guiding net installed, the air flow and heat transfer were simulated based on computational fluid mechanics （CFD）, and finally the fan inlet flow rate increasing mechanism was studied and expounded. The simulation study shows that if a set of wind guiding nets are installed, the vacuum under the windward DACC units reduces and the inlet flow rate increases, meanwhile unlike wind guiding plates to be installed, the downstream fans will not be affected.