Experimental determination of the efficiency of an air injection device in flowing water

流水中空气喷射装置效率的实验测定

• 批准号: 488506-2015
• 负责人: Etienne, Stéphane
• 金额: $ 1.82万
• 依托单位: École Polytechnique de Montréal
• 依托单位国家: 加拿大
• 项目类别: Engage Grants Program
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=586278
• 关键词: Experimental; determination; efficiency; air; injection

In North America, for ecological as well as economical reasons, fish-friendly hydroelectric equipment is preferred. In particular, the question of how much oxygen is contained in released waters from hydroelectric plants has been raised since it conditions the presence and health of fishes downstream of these structures. This, indeed, has an immediate effect on the river fish industry and biodiversity. More specifically, released waters are meant to meet standards on surface waters dissolved oxygen rates which must not fall beyond a prescribed threshold. On average, a minimum of 5 mg/l is required. For several locations, depending on seasons, oxygen depleted water is released by dams (natural dissolved oxygen gradient, leaf decomposition). Governments stiffen their legislations such that surface water dissolved oxygen standards are more and more enforced by the law. Hydroelectric turbine manufacturers need to re-oxygen water before release. In order to improve efficiently the oxygen content, they need to inject small air bubbles. The specific problem that Alstom faces is how to design and assemble air injection devices such that they generate bubbles of very small diameters that will be distributed uniformly downstream of the turbine. To fulfill the needs of Alstom, injection devices must be designed and tested for varying air and water flow rates. In particular the apertures that constitute the interface between water and air to be injected are a critical aspect of the injection device. As such, size and shape of various apertures will be tested for air injection. The experiments will be monitored to precisely measure air and water flow rates and pressures at inlet. Pressure transducers and optical probes will be used to this aim. Based on experimental results, correlations will be identified that will serve selecting best sizes and shapes. These correlations will serve to deduce partial similitude laws that will help devising injection apertures at real scale.

在北美，出于生态和经济原因，对鱼类友好的水力发电设备 首选。特别是水力发电释放的水中含有多少氧气的问题 人们之所以饲养植物，是因为它决定了这些建筑物下游鱼类的存在和健康。 这确实对河流渔业和生物多样性产生了直接影响。更具体地说，发布了 水域应满足地表水溶解氧率的标准，该标准不得超过 规定的阈值。平均而言，至少需要 5 毫克/升。对于多个位置，取决于 季节变化时，水坝会释放缺氧水（自然溶解氧梯度、树叶分解）。 各国政府加强立法，地表水溶解氧标准越来越高 依法强制执行。水轮机制造商需要在释放水之前对水进行重新充氧。为了 为了有效提高氧气含量，需要注入小气泡。 阿尔斯通面临的具体问题是如何设计和组装空气喷射装置，使其能够 产生直径非常小的气泡，这些气泡将均匀分布在涡轮机的下游。到 为了满足阿尔斯通的需求，喷射装置必须针对不同的空气和水流量进行设计和测试。 特别是构成要注入的水和空气之间的界面的孔是一个关键方面 注射装置的。 因此，将测试各种孔的尺寸和形状以进行空气注入。实验将受到监控 精确测量入口处的空气和水流量和压力。压力传感器和光学探头将 习惯于这个目标。 根据实验结果，将确定相关性，这将有助于选择最佳尺寸和形状。 这些相关性将有助于推导出部分相似定律，这将有助于设计实际的注入孔径。 规模。