大型水库帷幕水温分层取水效果研究

发布时间：2018-02-05 05:07

  本文关键词： 水库水温 分层取水 帷幕　出处：《工程科学与技术》2017年S1期 　论文类型：期刊论文

【摘要】：为探索减缓已建水库对下游产生的低温水不利影响的新措施,以某已建大型水库为例,开展不同帷幕布设方式对改善下泄低温水效果的研究。采用立面2维数学模型计算某大型水库坝前垂向水温结构及下泄水温过程,设计不同遮挡高度、淹没深度及距坝轴线距离等6个帷幕方案,并对各方案的流场及温度场进行对比分析。结果表明:帷幕设置将显著影响库区的浮力流动及垂向温度分布,3种局部遮挡方案下取水口的抽吸作用导致底层低温水体绕过帷幕被较多地引用,均不能有效提高下泄水温,底部全遮挡方案的设置对提高水库下泄水温效果明显,但同时由于持续取用表层温水,库区水温显著降低。淹没水深应结合取水层厚度确定,当淹没水深与帷幕上层取水层厚度相近时有较好的低温水改善效果。坝前1 km范围内帷幕轴线位置对下泄水温的影响不明显。建议水温控制帷幕的设计采用底部全遮挡,中底部全遮挡帷幕方案的下泄水温5—8月较无措施时分别升高了3.4、2.1、1.1、0.4℃,帷幕提高下泄水温效果明显。
[Abstract]:In order to explore the new measures to mitigate the adverse effects of the built reservoir on the downstream low temperature water, a large reservoir has been built as an example. The vertical water temperature structure in front of a large reservoir dam and the process of drainage temperature are calculated by using two dimensional elevation mathematical model, and different shielding heights are designed. Six curtain schemes, such as submerged depth and distance from the dam axis, are compared and analyzed. The results show that the curtain setting will significantly affect the buoyancy flow and vertical temperature distribution in the reservoir area. The suction of the water intake under three local occlusion schemes leads to the low temperature water at the bottom of the water being used more frequently to bypass the curtain, which can not effectively raise the temperature of the drainage. The setting of the bottom complete occlusion scheme has obvious effect on increasing the temperature of the reservoir drainage, but at the same time, the water temperature of the reservoir decreases significantly because of the continuous use of the surface warm water. The depth of the submerged water should be determined in combination with the thickness of the water intake layer. When the depth of submerged water is close to the thickness of the intake layer of the curtain upper layer, the improvement effect of low temperature water is better. In the range of km, the influence of the position of the curtain axis on the discharge temperature is not obvious. It is suggested that the design of the water temperature control curtain should adopt the bottom full occlusion. In May to August, the temperature of draining water in the middle and bottom complete shielding curtain was increased by 3.4 ~ 2.1L ~ (1.1) ~ 0.4 鈩，

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