潮流水轮机发电效率及潮流能资源估算研究

发布时间：2018-01-22 16:37

本文关键词： 潮流水轮机水动力性能改进爬山法潮流能资源估算　出处：《山东大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着全球能源问题日益严峻,人类势必要寻找新的可再生清洁能源。潮流能是指海水水平运动所含有的动能,具有分布广、储量大、可再生、无污染等特点,作为一种新兴的海洋能获取方式,受到人类的广泛重视。潮流水轮机是获取潮流能的关键设备,按结构不同主要分为水平轴和垂直轴两种,垂直轴水轮机虽然直接获能功率不如水平轴水轮机,但随着近年来研究的深入,逐渐体现出它的优势。开发潮流能资源首先要对其储量进行估算,不同水域需要不同的潮流能资源估算方法。选择适当的方法估算潮流能资源,对于资源开发整体规划、潮流能开发装置以及技术的选择都具有重要的指导作用。本文首先介绍了国外水平轴和垂直轴水轮机的研究和应用现状,然后结合风机系统经典贝茨理论和动量定理等基本原理,分别分析了水平轴和垂直轴水轮机叶片受力状况,建立水轮机水动力性能模型：推导经典叶素—动量理论,并引入叶尖、叶根损失,根据叶片受力和转矩的表达式确定叶片参数与诱导因子a、b的关系,并通过迭代方法来计算诱导因子,从而确定水轮机叶片参数的取值；以无量纲参数的形式给出水轮机各参数的数学表达式,并具体分析了叶尖速比和偏角对水动力性能的影响,然后以单盘面多流管模型(SDMT)为例,以无量纲参数形式给出其动量方程的表达式。在此基础上,对水轮机发电效率进一步研究,基于已有最大功率跟踪(MPPT)方法,对比分析几种方法优劣,将三步法和爬山搜索法(HCS)优点相结合,采用变步长求导对传统爬山搜索法加以改进,克服了其易震荡收敛慢的缺点,提高其收敛速度,Matlab/Simulink仿真结果表明,在误差允许范围内该方法能够准确地辨识出水轮机参数,确定符合最大潮流能捕获策略的最佳转速值,并且系统响应潮流流速变化快,实现最大潮流能捕获。本文还对国内外潮流能资源估算方法展开讨论。首先介绍了国内外潮流能资源估算的几种方法,然后对比分析了几种方法的优劣：Farm方法计算思路明确,但是随着水轮机效率的提高和装置不断改进,该方法存在较大不确定性；Flux方法与设备无关,但是SIF因子需要依赖经验取值；Garrett方法克服了常规计算方法的一些弊端,但可靠性仍有待检验；国内郑志南方法公式简单明确,对于中国潮流能资源估算具有一定的实用性,然而由于该公式计算的是正规半日潮往复流的可开发量,应用范围较窄。最后,指出潮流能资源评估应有规范的标准,并展望了未来潮流能资源的调查和评估重点。
[Abstract]:With the global energy problem becoming more and more serious, mankind is bound to look for new renewable clean energy. Tidal energy refers to the kinetic energy contained in the horizontal movement of seawater, which has the characteristics of wide distribution, large reserves, renewable, no pollution and so on. As a new way of obtaining ocean energy, people pay more and more attention to it. Tidal current turbine is the key equipment to obtain tidal current energy, which can be divided into horizontal axis and vertical axis according to different structure. Although the direct power of vertical shaft turbine is lower than that of horizontal shaft turbine, with the development of research in recent years, it gradually reflects its advantages. In order to develop tidal energy resources, it is necessary to estimate its reserves. Different water areas need different methods of estimating tidal current energy resources. Selecting appropriate methods to estimate tidal current energy resources is the overall planning of resource development. Power flow energy development device and the choice of technology have important guiding role. This paper first introduces the research and application of horizontal and vertical axis turbines abroad, and then combines the classical Bates theory and momentum theorem of fan system. The hydraulic performance model of horizontal and vertical shaft turbine blades is established. The classical theory of vane momentum is derived and the loss of blade tip and blade root is introduced. According to the expression of blade force and torque, the relationship between blade parameters and induction factor ab is determined, and the induction factor is calculated by iterative method, so as to determine the value of blade parameters of hydraulic turbine. The mathematical expressions of hydraulic turbine parameters are given in the form of dimensionless parameters, and the effects of tip speed ratio and deflection angle on hydrodynamic performance are analyzed in detail. The expression of its momentum equation is given in the form of dimensionless parameters. On this basis, the turbine generation efficiency is further studied, based on the existing maximum power tracking MPPTs, the advantages and disadvantages of several methods are compared and analyzed. By combining the advantages of the three-step method and the mountain-climbing search method, the traditional mountain-climbing search method is improved by using variable step length derivation, which overcomes its shortcoming of easy concussion and slow convergence, and improves its convergence speed. The Matlab/Simulink simulation results show that the method can accurately identify the turbine parameters and determine the optimal speed value in accordance with the maximum power flow energy capture strategy. And the system changes fast in response to the power flow velocity, realizing the maximum power flow energy capture. This paper also discusses the estimation methods of power flow energy resources at home and abroad. Firstly, several methods of power flow energy resource estimation at home and abroad are introduced. Then the comparison and analysis of the advantages and disadvantages of the several methods: the thinking of calculation is clear, but with the increase of turbine efficiency and the continuous improvement of the device, there is greater uncertainty in this method. The Flux method has nothing to do with the device, but the SIF factor depends on the empirical value. The Garrett method overcomes some disadvantages of the conventional calculation method, but the reliability still needs to be tested. The formula of Zheng Zhinan's method is simple and clear in China, which has some practicability for estimating the energy resource of tidal current in China. However, because the formula is used to calculate the available amount of normal half-day tidal reciprocating flow, the application range is relatively narrow. It points out that the evaluation of tidal current energy resources should be standardized, and looks forward to the investigation and evaluation of tidal current energy resources in the future.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM312

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