控制幕运行方式改善下泄水温及其成因研究

控制幕取水方式能够有效地减缓温度分层型水库下泄低温水对下游生态环境的不利影响,但目前缺乏控制幕运行方式下泄水温规律的试验研究以及对下泄水温成因的分析。本文基于某水库水温资料,首先通过试验探讨不同控制幕运行方式对下泄水温的改善效果,总结下泄水温规律。其次,利用三维数学模型进行精细模拟,分析控制幕表层和底层同时过流运行方式的流动规律,探讨下泄水温成因。结果表明:控制幕表层过流运行方式能够显著提高下泄水温;采用控制幕表层底层同时过流运行方式时,主流区位于控制幕顶部和底部,下泄水体主要由表层高温水与底层低温水掺混而成,下泄水温取决于所取表层高温水和底层低温水的掺混比例。研究成果对温度分层型水库控制幕取水的运行调度具有重要意义。

Investigation on the response of discharged water temperature to operation mode of the temperature control curtain

A temperature control curtain could effectively mitigate the negative effects of discharged low temperature water on the river eco-environment downstream. However,the response of discharged water temperature to the operation mode of temperature control curtain and its formation mechanism are lacking. To investigate the effect of operation mode of temperature control curtain on the discharged water temperature, experiments were conducted based on a thermally stratified reservoir. Then,a 3-D numerical model was applied to analyze flow laws and explore the formation mechanism of discharged water temperature. The results indicateds that the operation mode of surface overcurrent significantly improves the discharged water temperature. When running the operation mode of surface and bottom overcurrent,the high temperature water and low temperature water flowed from top and bottom of the curtain owing to the barrier effect of curtain, and thus the discharged water temperature depended on the mixing ratio of the high temperature water to the low temperature water. These findings are meaningful for the operation of temperature control curtain in thermal stratified reservoirs.