温度分层水库下泄水温研究

发布时间：2018-07-06 08:42

本文选题：温度分层水库 + 分层取水　；参考：《天津大学》2014年博士论文

【摘要】：高坝大库的修建形成了大面积的停滞水域，加之太阳辐射以及其他理化作用，水库内水温沿水深呈明显的季节性分层分布。传统底层取水的下泄水温较低，会对下游水生生物的生长和繁殖造成危害，并产生水库放流浊水长期化等问题。因此，如何有效的提高水库下泄水温，减免下泄低温水带来的生态环境影响已经成为人们日益关注的问题和学者研究的焦点。分层取水措施可以提高下泄水温，进而有效缓解低温水对下游生态环境带来的负面影响，因此被越来越多的应用于大型水利工程中。常见的分层取水措施有很多种，如侧式孔流型取水口、溢流式叠梁门取水口、浮式管型取水口和控制幕取水等。本文的主要工作分为三部分：第一部分为下泄水温模型试验相似理论的介绍、扩展及相应温度分布转化理论的提出。第二部分为利用试验手段，针对侧式孔流型取水口和浮式管型取水口进行了下泄水温研究，试验选用多种水温分布、取水口淹没深度以及下泄流量，通过大量试验成果，分析下泄水温的变化规律和影响因素。第三部分为利用PIV系统，针对侧式孔流型取水口的流场进行初步研究。本文主要研究内容及成果如下：（1）介绍了水库水温分层的形成机理、低温下泄水的影响、减免下泄低温水影响的相应措施以及常见的分层取水形式。对水库水温结构判别、水库水温的预测和模拟方法进行了归纳。从数值模拟研究和试验研究两个方面总结了分层取水的研究成果。（2）对现有水库分层取水水温模型试验相似理论进行了扩展，增加了新的模型相似条件。结合实际操作中遇到的问题，提出了模型与原型底层基础水温不同时，模型满足相似条件所需要进行的水温分布转化方法，并对转化后的原型模型下泄水温换算公式进行了推导。（3）结合水温模型试验相似理论，建立了相应的模型，利用试验方法，对侧式孔流型取水口和浮式管型取水口的下泄水温进行研究。试验以某水库三个典型月份水温分布资料为背景，选取多种淹没深度取水口结合多种下泄流量的组合工况进行研究。结合试验成果，分析水库水温分层对取水的影响，探讨分层取水的取水范围，研究水温分布、取水口淹没深度以及下泄流量对下泄水温的影响，比较两种不同类型取水口的取水特点，总结下泄水温变化规律，提出了侧式孔流型取水口下泄水温预测公式。（4）针对侧式孔流型取水口，采用PIV系统对温度分层条件下取水口附近的流场进行了初步研究。对水温分层是否会引起水库内的流场变化进行了判断，分析了侧式孔流型取水口附近水体的流动规律，，总结了侧式孔流型取水口的取水特点。
[Abstract]:With the construction of the large reservoir of high dam, a large area of stagnant water area is formed, together with the solar radiation and other physicochemical effects, the water temperature in the reservoir is obviously distributed in seasonal stratification along the water depth. The lower water temperature of the traditional bottom water will harm the growth and reproduction of aquatic organisms in the lower reaches, and cause problems such as the long-term development of the reservoir discharge turbidity water and so on. Therefore, how to effectively improve the reservoir drainage temperature, reduce the impact of low-temperature water drainage ecological environment has become a growing concern and the focus of scholars. Stratified water intake measures can increase the temperature of water discharge, and then effectively alleviate the negative impact of low temperature water on the ecological environment downstream, so it is more and more used in large-scale water conservancy projects. There are many kinds of stratified water intake measures, such as side orifice, overflow beam gate, floating pipe and control screen, etc. The main work of this paper is divided into three parts: the first part is the introduction of the similarity theory of the model test, the extension and the theory of the corresponding temperature distribution transformation. The second part is to use the test method to study the outlet temperature of the side orifice and the floating pipe. A variety of distribution of water temperature, submerged depth of the intake and discharge of the outlet are selected in the experiment, and a large number of experimental results are obtained. The variation law and influencing factors of the temperature of the downdraining water are analyzed. In the third part, the flow field of the side orifice is studied by using PIV system. The main contents and achievements of this paper are as follows: (1) the formation mechanism of reservoir water temperature stratification, the influence of low temperature water discharge, the corresponding measures of reducing and reducing the influence of low temperature drain water and the common layering water intake form are introduced. The structure of reservoir water temperature, the prediction and simulation methods of reservoir water temperature are summarized. The research results of stratified water intake are summarized from two aspects of numerical simulation and experimental research. (2) the similarity theory of model test for stratified water intake temperature of existing reservoirs is extended and a new model similarity condition is added. According to the problems encountered in practical operation, the method of water temperature distribution transformation is proposed, which is different from the model and prototype bottom water temperature, and the model meets the similar conditions. The conversion formula of the converted prototype model is deduced. (3) combined with the similarity theory of water temperature model test, the corresponding model is established, and the test method is used. The downdraining temperature of lateral orifice and floating pipe is studied. Based on the data of water temperature distribution in three typical months of a reservoir, the combined working conditions of various submergence depth intake and discharge are selected. Based on the experimental results, the influence of water temperature stratification on water intake is analyzed, and the range of water intake by stratification is discussed. The distribution of water temperature, the depth of water intake submerged and the effect of discharge on the water discharge temperature are studied. This paper compares the characteristics of two different types of water intake, sums up the variation law of outlet temperature, and puts forward a formula for predicting the outlet temperature of side orifice. (4) aiming at the side orifice, The PIV system is used to study the flow field near the water intake under the condition of temperature stratification. Whether the stratification of water temperature will cause the change of the flow field in the reservoir is judged, the flow law of the water body near the side orifice is analyzed, and the characteristics of the water intake of the side orifice are summarized.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TV697.21

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