[关键词]
[摘要]
哈密某电厂在其空冷岛中使用了一种新型消能导流装置来抵抗侧风影响、稳定机组背压。然而,该电厂冬季空冷单元散热管束冻结的情况依然存在。为了探究该装置对空冷岛冬季防冻的影响,利用Fluent软件对该电厂冬季大风时空冷岛的流动传热特性及各空冷单元的冻结风险进行了模拟研究。研究表明:空冷岛“消能导流装置”整体上对空冷单元的防冻起负面作用;在冬季大风条件下该装置迎风侧空冷单元的散热量平均超出警戒值27%以上,最高达到50%;消能导流装置主要通过提升轴流风机空气流速来增加对应空冷单元的换热量,该装置迎风侧空冷单元轴流风机的轴向空气流速甚至能达到与环境侧风相同的水平,这导致对应空冷单元换热量激增,更容易出现冻结事故;大风条件下该装置在空冷岛下方形成的高压区域分布并不均匀,临近主厂房与相邻空冷岛一侧的高压区域压力更高、面积更大,这些区域空冷单元的冻结风险更高。·
[Key word]
[Abstract]
Hami power plant used a new type of "energy dissipation diversion device" in its aircooling island to resist the crosswind influence and stabilize unit back pressure. However,the cooling tube bundle in the aircooling unit of the power plant still freezed in winter. In order to explore the effect of the device on the antifreezing of the aircooling island in winter,the simulation research on the flow and heat transfer characteristics of aircooling island and the freezing risk of each aircooling unit under the winter gale condition was carried out by using the Fluent software.The research result shows that the "energy dissipation diversion device" of aircooling island has a negative effect on antifreezing of aircooling unit integrally. Under the winter gale condition,the heat dissipation of the aircooling units on the windward side of the device is about 27% higher than the warning value on average,with the maximum value of more than 50%.The "energy dissipation diversion device" mainly increases the heat transfer of the corresponding aircooling unit by increasing the air velocity of the axial flow fan. The axial air velocity of the axial flow fan in the aircooling units at the windward side of the device can even reach to the same level as the ambient crosswind,which leads to a surge of the heat exchange of corresponding aircooling units,and makes it easier to be frozen. Under the strong wind conditions,the highpressure area formed by the device under the aircooling island is not evenly distributed. The highpressure area near the main plant and adjacent aircooling island has higher pressure and larger area,and the aircooling units in these areas have higher freezing risk.
[中图分类号]
TK121
[基金项目]
国家重点研发计划(2019YFB1505403)