导流板布置方式对空冷单元流场影响的数值模拟

Numerical Simulation of the Influence of Flow Guide Plate Layout on the Flow Field of Air Cooling Unit

空冷单元内部流场不均匀,A字架散热管束底角区域冷却不充分,导致凝汽器换热效率差.通过改变空冷单元内部导流板的布置方式,可改善其内部冷却空气的流场,提高空冷凝汽器的传热性能.采用RNG κ-ε湍流模型,对不同布置方式的导流板空冷单元进行数值模拟,分析对比了导流板倾角在20°~50°和导流板数量在2块-10块范围内散热管束表面的温度场.结果表明:加装导流板的空冷单元内部流场均匀性显著提高;当风机出口安装倾角为30°的导流板时,散热管束表面局部高温区域消失;当风机出口安装8块导流板时,散热管束表面平均温度最低,凝汽器换热效果最佳.

The non-uniformity of internal flow field in air cooling unit and the insufficiency of cooling in bottomcorners region of A-shape cooling tubes leads to the poor heat transfer efficient of the condenser. Changing thearrangement of internal guide plates in air cooling unit will improve flow field of cooling air,thus resulting inthe promoting in heat transfer efficiency of the condenser. By using standard κ-ε turbulence model for numeri-cally simulating guide plates air cooling units with different arrangement,it can analyze and compare coolingtubes surface temperature fields when the guide plates incline at 20° ~ 50°and the plate number is 2 ~ 10. Theresults show that the uniformity of internal flow field in air cooling units with guide plates significantlyimprove;The local high temperature region of cooling tubes surface disappears when installing the 30° guideplates at the outlet of fan;Lowest average temperature of cooling tubes and best heat transfer efficiency of con-denser will be found when installing 8 guide plates at the fan outlet.