水平挡板改善直接空冷凝汽器流场特性的数值模拟

Numerical Simulation on Flow Field of Direct Air-cooled Condenser Improved by Horizontal Baffles

以某1000 MW直接空冷机组凝汽器的一组空冷单元为研究对象,建立了物理模型和数学模型,通过计算流体力学模拟分析,研究横向风对空冷机组凝汽器的影响规律和水平挡板改善风机入口侧流场的机理.结果表明:加装水平挡板可以使空冷凝汽器横向风迎风侧第一单元风机入口的负压区前移,有效削弱横向风的不利影响,增加空冷单元进风的质量流量;对于所研究的直接空冷机组凝汽器,水平挡板的最佳长度为15 m.

Taking the direct air-cooled condenser（DACC） of a 1 000 MW unit as an object of study,physical and mathematical models have been built so as to study the influence of ambient crosswind on the DACC and the improving mechanism of horizontal baffles on the inlet flow field,through analysis based on computational fluid dynamics.Results show that the installed horizontal baffle makes the negative pressure zone at fan inlet of cell 1 move forward on the side facing the crosswind,which therefore effectively weakens the impact of ambient crosswind and raise the mass flow rate of air intake.For the DACC studied,the optimal length of the horizontal baffle is recommended as 15 m.