论文部分内容阅读
以2×600MW直接空冷机组为例,利用CFD软件对其空冷岛外部流场进行数值模拟。分析了不同高度的下挡风墙对直接空冷凝汽器风机风量的影响。在风速大于7m/s时,空冷凝汽器换热效率的降低是热风回流与“倒灌”现象综合作用的结果。提出了加装曲面下挡风墙的方案,并计算了加装不同高度的曲面下挡风墙对背风面风机的风量和风机换热效果的影响。结果表明,最佳下挡风墙高度为8.5m,此时的风机风量达到最大,换热效果最好,前2排风机平均换热效率比没有安装下挡风墙时提高了17.03%。研究成果为进一步完善空冷岛的结构设计提供了理论依据。
Take the 2 × 600MW direct air-cooled unit as an example, the CFD software is used to simulate the flow field outside the air-cooled island. The influence of the different height of the lower wind wall on the air volume of the direct air-cooled condenser fan was analyzed. When the wind speed is more than 7m / s, the decrease of the heat transfer efficiency of the air-cooled condenser is the result of the combined effect of the hot air return and the “backflow” phenomenon. The scheme of installing a curved wall under the curved surface is proposed. The influence of the lower surface curved wall with different heights on the air volume of the leeward side fan and the heat transfer effect of the fan is also calculated. The results show that the optimal height of the lower windshield is 8.5m, and the air volume of the fan reaches the maximum at this moment, and the heat exchange effect is the best. The average heat transfer efficiency of the first two exhaust fans is 17.03% higher than that without the lower windshield. The research results provide a theoretical basis for further improving the structural design of air-cooled island.