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以国内某2?300 MW直接空冷机组为例,利用FLUENT软件,数值模拟空冷平台下部加装防风网对空冷岛换热性能的影响,并对比分析了加装防风网前后,空冷岛附近的空气流场以及温度场变化规律。结果表明:加装防风网能够提高大风天气下风机出力,抑制“热风回流”的产生,提高空冷岛换热性能。分别分析了在不同风速的炉后来风和侧边来风下,安装不同开孔率和网高的防风网对空冷岛换热效率的影响规律,发现加装开孔率为6%、13%防风网的空冷岛换热效率一般低于开孔率为25%、44%的换热效率;空冷岛换热效率随着防风网高度的增大呈现先上升后下降的趋势,最优防风网结构是开孔率为25%、网高为12 m。研究结果为直接空冷机组加装合适结构的防风网提供了理论依据。
Taking a domestic 2? 300 MW direct air-cooled unit as an example, using FLUENT software, numerical simulation of air-cooled cooling towers under the lower part of the installation of air-cooled island heat exchange performance, and comparative analysis of the air before and after the installation of air-cooled island Flow Field and Temperature Field Variation. The results show that the installation of windbreaking net can increase the output of fan in windy days and restrain the occurrence of hot air backflow and improve the heat transfer performance of air-cooled island. The influence of wind-proof mesh with different opening ratio and mesh height on heat transfer efficiency of air-cooled island was analyzed respectively under wind and side wind coming from different wind speed furnaces. It was found that the opening rate was 6%, 13% Air-cooled island heat exchange efficiency of air-cooled island is generally lower than the opening rate of 25%, 44% of the heat transfer efficiency; air-cooled island heat exchange efficiency increases with the height of the windbreak showed a trend of rising first and then decreasing, the optimal windbreak The structure is 25% open hole, net height of 12 m. The results provide a theoretical basis for the direct air-cooled unit to install a wind-proof net with a suitable structure.