Aeration of hydraulic turbines to increase downstream dissolved oxygen concentration

在温暖的气候中，温暖的温度会导致水电站水库中的热分层，从而抑制混合 并导致储层的低水层中的沃茨脱氧。抽水涡轮机. 从低水层的深度导致在下游流中几乎没有溶解氧， 对下游河流生态系统造成巨大负面影响。现在美国和其他地方的立法 要求水电运营商保证满足溶解氧浓度的最低限度， 下游流量。存在两大类对涡轮机流进行再充气的方法。第一类是 成功但导致收入和能源生产损失的监管办法。其次是 技术方法，被认为是更具有成本效益的行业。加拿大安德里茨水电公司拥有 启动了这个项目，以优化用于尾水管曝气手肘偏转器，这是一种改造方法 不会过度影响运营时间表。他们已经实现了第一个导流管的原型 在约翰H.克尔发电厂，证明了该系统的可行性。的 主要的交付成果将是通过对设计的参数研究，手肘偏转器进行优化 最大化气泡表面积和气泡浓度所涉及的参数， 溶解氧浓度，以及一组用于验证Andritz CFD模型的数据，这将使 生产符合DO规格的原型设计。手肘导流板的物理比例模型 将在麦吉尔实验室建造并测试参数研究将有助于理解 物理过程和一组定量数据，以获得CFD模型的验证。的 该项目将受益于加斯金教授15年的水电水力学研发经验。ANDRITZ 加拿大水电将自己定位为水电项目的领导者， 溶解氧很重要（气候温暖的国家，如美国，西班牙），能够保证会议（或 超过）溶解氧的规定要求，同时优化涡轮机性能。

In warm climates warm temperatures cause thermal stratification in hydropower reservoirs inhibiting mixing and leading to deoxygenation of waters in the hypolimnion of the reservoir. Turbines withdrawing water at depth from the hypolimnion results in little to no dissolved oxygen in the downstream flow which can have a large negative impact on the downstream riverine ecosystem. Legislation in the USA and elsewhere now requires hydropower operators to guarantee meeting minimum limits for dissolved oxygen concentrations in downstream flows. Two broad categories of methods for re-aerating turbine flows exist. The first are regulatory approaches that are successful but lead to a loss of revenue and energy production. The second are technological approaches that are viewed as more cost-effective in the industry. Andritz Hydro Canada has initiated this project to optimize the elbow deflectors used in draft tube aeration, which is a retrofit approach not excessively impacting operation schedules. They have implemented one of the first prototypes of draft tube aeration using elbow deflectors at the John H. Kerr power plant, demonstrating the viability of the system. The main deliverables will be the optimization of the elbow deflectors, through a parametric study of the design parameters involved in maximizing bubble surface area and bubble concentration to result in an increase in dissolved oxygen concentration, and a set of data for validation of Andritz's CFD model, which will enable them to produce prototype designs meeting DO specifications. A physical scale model of the elbow deflector will be built and tested in the McGill laboratory. A parametric study will allow for both an understanding of the physical processes and for a set of quantitative data to be obtained for validation of CFD models. The project will benefit from the 15 years of experience in R&D of hydropower hydraulics of Prof. Gaskin. Andritz Hydro Canada will position itself as a leader for hydropower projects in which environmental impacts of low dissolved oxygen are important (countries with warm climates, e.g. USA, Spain) able to guarantee meeting (or exceeding) the regulatory requirements for dissolved oxygen while optimizing turbine performance.