叠梁门分层取水对下泄水温的改善效果

水库升温期泄放低温水现象是大中型水电工程普遍面临的环境问题.叠梁门分层取水是提高水库下泄水温的有效工程措施,也是水电工程生态环境保护尤其是水生态保护的重要手段.以滩坑水电站叠梁门分层取水设施投入运行前后的水温观测为基础,从水库调度过程和不同取水口形式等方面分析了叠梁门运行对下泄水温的改善效果.针对库区坝前水温和发电下泄水温对分层取水措施的响应规律,探讨了通过调整门顶水深进一步改善下泄水温的可行性.认为滩坑水库较大的垂向温差是形成下泄低温水的主要原因,叠梁门门顶水深对下泄水温具有决定性影响,应尽可能降低门顶水深以提高下泄水温.提出了优化叠梁门设计及运行管理的建议.

Raising Discharge Water Temperature by Using Water-Level-Selection with Stoplog Gate

The discharging of low temperature water during the air temperature rising period becomes a general environmental problem that the large and middle hydropower works are facing. Taking water from different layers with stoplog gate is effectively applied to warming up the discharged water and protecting the environment, especially the aquatic environment of the hydropower works. Based on the observed water temperature data before and after the use of stoplog gate in Tankeng hydropower station, the rise in the discharged water temperature was analyzed by using the stoplog gate, from the aspects of the reservoir operation process and different water intake types. Furthermore, considering the temperature＇s feedback to the use of taking water from different layers with stoplog gate, we discussed the feasibility of rising discharged water temperature by adjusting water depth above the top of stoplog gate. Results suggest that the vertical temperature difference of Tankeng hydropower station is mainly influenced by the discharging of low temperature water. The water depth above the top of stoplog gate has a decisive influence on the discharge water temperature. So we should decrease water depth above the top of stoplog gate as much as possible to raise the discharge water temperature. Some further suggestions about design and operation management of the stoplog gate are also proposed in this research.