低流速潮流能捕能桨叶动力优化设计

发布时间：2018-07-07 22:27

本文选题：低流速 + 能量捕获　；参考：《太原科技大学》2015年硕士论文

【摘要】：在20世纪,以石油为主的化石能源推动了人类社会文明的高速发展。但随着人口膨胀和对地球资源不加节制的过度开发,能源供应日益紧张。同时,大量化石能源的使用带来的环境污染问题也越来越严重。人类必须阻止问题的进一步恶化,推广绿色可再生能源的使用。在走可持续发展道路和发展低碳经济成为全球各国共识的今天,开发利用新能源成为新的经济增长点。而中国是一个人口众多,人均能源拥有量很低的国家。开发和利用新能源势在必行。高效利用潮流能发电能极大缓解人均能源不足的问题。在水平轴潮流能发电装置部件中,桨叶作为能量捕获的部分,其重要性不言而喻。桨叶的设计直接关系到装置的发电效率的高低。而我国沿海大部分水道的海水流速较低,优化在低流速条件下水平轴潮流能发电桨叶的设计势在必行。传统桨叶设计是直接套用风力发电装置,利用的是流体经过桨叶产生升力。翼型周围存在绕流,其外表面上的流体流速是不同的,致使下表面压力较上表面大,即产生一个方向垂直来流合速度的升力。而其分量即是所要捕获的动力。但用在低流速近海的条件下是行不通的。压差升力的大小与流速的平方成正比;随着来流速度的减小,使桨叶的捕能效率急剧下降。本文提出一种桨叶设计方法,不同于传统的按风力发电设计潮流能发电桨叶的方法。由于桨叶的作用,水流通过桨叶时速度会发生分解。使桨叶转动的作用来自于方向垂直于出流速度的海水对桨叶的冲击,基于叶素理论,分析桨叶受到的冲击力,建立动力学模型。在能量捕获效率最大的条件下,运用非线性优化方法求得桨叶设计参数,由此可得到桨叶外形。本文设计制作了两种潮流能发电桨叶,一种是按捕获冲击动力进行设计,另一种是按捕获压差动力进行设计,详细分析了两种桨叶的弦长与桨距角的差别,并且实际加工了两种桨叶。通过设计的桨叶测试系统进行试验,对优化后桨叶和未优化桨叶的实验数据进行分析对比,证明按捕获冲击动力进行设计的桨叶在低流速条件下能获得更大的功率。证明了此优化设计方法的可行性和有效性。
[Abstract]:In the 20 th century, petroleum-based fossil energy promoted the rapid development of human civilization. But with population expansion and uncontrolled overexploitation of the planet's resources, energy supplies are becoming increasingly tight. At the same time, the environmental pollution caused by the use of a large amount of fossil energy is becoming more and more serious. Humans must stop the problem from getting worse and promote the use of green renewable energy. Nowadays, with the development of low-carbon economy and sustainable development, the development and utilization of new energy has become a new economic growth point. China is a country with a large population and low energy per capita. It is imperative to develop and utilize new energy. Efficient use of tidal power generation can greatly alleviate the problem of energy shortage per capita. The importance of blade as the part of energy capture is self-evident in the component of horizontal axis power generation device. The design of blade is directly related to the efficiency of power generation. However, the velocity of sea water in most waterways of our country is low, so it is imperative to optimize the design of horizontal axis tidal current power generation blade under low velocity. Traditional blade design is a direct application of wind power equipment, the use of fluid through the blade to generate lift. There is a flow around the airfoil, and the flow velocity on the outer surface is different, which results in a higher pressure on the lower surface than on the upper surface. And its component is the power to capture. However, it is not feasible to use it in low velocity offshore conditions. The lift of the pressure difference is proportional to the square of the velocity of flow, and the efficiency of energy capture of the blade decreases sharply with the decrease of the velocity of the incoming flow. In this paper, a blade design method is presented, which is different from the traditional wind power design method. As a result of the blade action, the velocity of flow through the blade will decompose. The effect of blade rotation is derived from the impingement of seawater perpendicular to the velocity of outlet flow on the blade. Based on the theory of blade element, the impact force on the blade is analyzed and a dynamic model is established. Under the condition of maximum energy capture efficiency, the blade design parameters are obtained by nonlinear optimization method, and the blade shape can be obtained. In this paper, two kinds of tidal current power generation blades are designed, one is designed according to the capture impact force, the other is the capture pressure differential force. The difference between the chord length and the pitch angle of the two kinds of blades is analyzed in detail. And two kinds of blades are actually processed. The experimental data of the optimized blade and the unoptimized blade are analyzed and compared by the designed blade test system. It is proved that the blade designed according to the capture impact force can obtain greater power under the condition of low velocity of velocity. The feasibility and effectiveness of the optimal design method are proved.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM612

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