海流能利用技术研究进展与展望

首先介绍了海流能的定义、成因和我国海流能资源的分布情况,在此基础上,指出海流能的主要利用方式是发电,然后介绍了国内外利用海流能发电的发展进程.从海流能发电站、发电装置和所涉及的一些关键问题等方面阐述了海流能发电技术的研究现状,最后对海流能开发技术的发展趋势和前沿技术进行了展望,指出未来的海流能发电将向大型化发展.     

海流发电发展方向及技术路线思考

海流能作为海洋能的重要组成部分,越来越多的受到世界各国新能源开发的关注,海流发电两大主要发展方向是作为常规能源补充的近水面的大规模开发利用和深海的特种设备能源补充。介绍了二者的国内外研究现状以及各自的技术问题。构想了深海锚泊系统能源补充的小型海流能发电装置,并给出未来中国发展海流能发电技术的建议。     

海流能开发利用技术发展及关键技术思考

主要介绍了海流能的可利用价值,并在此基础上阐述了国内外海流能发电装置的研究进展。从叶片、功率控制方式、自对流方式、传动方式以及安装维修等方面简述了世界各国对海流能发电装置关键技术的改进措施,并提出了目前开发利用海流能仍需解决的一些关键技术问题。     

链斗式海流发电船的设计方案

本文概述了当今世界利用海洋能的成果。提出初步设计方案，并论证在我国发展海流发电船的可行性和经济性。     

风力发电技术讲座(六) 风电场及风力发电机并网运行

风电场（即风力发电场）是大规模利用风能的有效方式.风电场是在风能资源良好的较大范围内,将几台、或几十台、或几百台单机容量数十千瓦、数百千瓦,乃至兆瓦的风力发电机,按一定的阵列布局方式,成群安装组成的向电网供电的群体.     

丹再和风力发电机

简单回顾了丹麦开发风力发电机的历史，介绍了丹麦风国委电机的主要特性、国内安装情况和出口情况，评价了丹麦风力发电机的经济性和环境效益。列了了丹麦风力发电机的主要制造商和产品。     

小波分析法在汽轮发电机转子绕组匝间短路故障诊断中的应用

提出了基于小波变换的汽轮发电机转子绕组匝间短路故障检测的一种诊断方法。这种方法是在探测线圈法的基础上，把小波变换用于突变信号的检测，对气隙中感应电势信号的故障特征进行提取和信号的消噪，可实现对发电机转子绕组匝间短路故障的检测。仿真实例表明，小波分析方法适合于转子绕组匝间短路故障的检测。图3参5     

美国拨款开发潮汐能、海流能和波浪能

美国能源部于2008年5月中旬宣布,拨款750万美元用于开发潮汐能、海流能和波浪能。海洋占地球表面超过70％,采用环境适用的技术就可能从海洋波浪、潮汐或海流取得能量。美国能源部正在推进开发新一代技术,以应用于增加使用清洁的可再生能源,实现2025年减少温室气体排放的国家目标。     

Marine current energy resource assessment and design of a marine current turbine for Fiji

Pacific Island Countries (PICs) have a huge potential for renewable energy to cater for their energy needs. Marine current energy is a reliable and clean energy source. Many marine current streams are available in Fiji's waters and large amount of marine current energy can be extracted using turbines. Horizontal axis marine current turbine (HAMCT) can be used to extract marine current energy to electrical energy for commercial use. For designing a HAMCT, marine current resource assessment needs to done. A potential site was identified and resource assessment was done for 3 months. The coordinates for the location are 18°12′1.78″S and 177°38′58.21″E; this location is called Gun-barrel passage. The average depth is 17.5 m and the width is nearly 20 m – the distance from land to the location is about 500 m. A multi cell aquadopp current profiler (ADCP) was deployed at the site to record marine currents. Strong marine currents are recorded at this location, as a combination of both tidal and rip currents. The maximum current velocity exceeds 2.5 m/s, for days with large waves. The average velocity was 0.85 m/s and power density for the site was 525 W/m². This site has good potential for marine current and HAMCT can be installed to extract power. A turbine with diameter between 5 and 8 m would be suitable for this site. Therefore, a 5 m HAMCT is designed for this location. The HF10XX hydrofoils were used from blade root (r/R = 0.2) to tip (r/R = 1.0). HF10XX series hydrofoil sections were designed to operate at varying turbine operating conditions; these hydrofoils have good hydrodynamic characteristics at the operating Reynolds number. The turbine is designed to operate at rated marine current speed of 1.5 m/s, cut in speed of 0.5 m/s and cut off speed of 3 m/s at a tip speed ratio (TSR) of 4.2.     

某型船用燃气轮机低压压气机的结构设计

本文作为文献[1]的姊妹篇,论述某型船用燃气轮机新型低压压气机的结构设计特点。经试制、部件试验及全台压气机试验表明,该压气机满足了第二代船用机组可靠性、长寿命、易维护性和可调整性等方面的要求。     

Blade sections for wind turbine and tidal current turbine applications–current status and future challenges

The designers of horizontal axis wind turbines and tidal current turbines are increasingly focusing their attention on the design of blade sections appropriate for specific applications. In modern large wind turbines, the blade tip is designed using a thin airfoil for high lift : drag ratio, and the root region is designed using a thick version of the same airfoil for structural support. A high lift to drag ratio is a generally accepted requirement; however, although a reduction in the drag coefficient directly contributes to a higher aerodynamic efficiency, an increase in the lift coefficient does not have a significant contribution to the torque, as it is only a small component of lift that increases the tangential force while the larger component increases the thrust, necessitating an optimization. An airfoil with a curvature close to the leading edge that contributes more to the rotation will be a good choice; however, it is still a challenge to design such an airfoil. The design of special purpose airfoils started with LS and SERI airfoils, which are followed by many series of airfoils, including the new CAS airfoils. After nearly two decades of extensive research, a number of airfoils are available; however, majority of them are thick airfoils as the strength is still a major concern. Many of these still show deterioration in performance with leading edge contamination. Similarly, a change in the freestream turbulence level affects the performance of the blade. A number of active and passive flow control devices have been proposed and tested to improve the performance of blades/turbines. The structural requirements for tidal current turbines tend to lead to thicker sections, particularly near the root, which will cause a higher drag coefficient. A bigger challenge in the design of blades for these turbines is to avoid cavitation (which also leads to thicker sections) and still obtain an acceptably high lift coefficient. Another challenge for the designers is to design blades that give consistent output at varying flow conditions with a simple control system. The performance of a rotating blade may be significantly different from a non‐rotating blade, which requires that the design process should continue till the blade is tested under different operating conditions. Copyright © 2012 John Wiley & Sons, Ltd.     

船用三轴燃气轮机故障方程的通用计算及分析

本文基于船用三轴燃气轮机的实际热力模型,推导出通用的故障方程。并采用Delphi7．0软件编写了该故障方程的小偏差系数的可视化计算程序。该计算程序适用于不同机型的三轴燃气轮机,减少了计算故障方程时的重复工作量;基于程序进行了仿真分析,着重研究了环境温度对故障方程系数的影响,所得结果可为燃气轮机故障诊断理论的实际应用提供参考。     

On the definition of the power coefficient of tidal current turbines and efficiency of tidal current turbine farms

During the last decade, the development of tidal current industries has experienced a rapid growth. Many devices are being prototyped. For various purposes, investors, industries, government and academics are looking to identify the best device in terms of of cost of energy and performance. However, it is difficult to compare the cost of energy of new devices directly because of uncertainties in the operational and capital costs. It may however be possible to compare the power output of different devices by standardizing the definition of power coefficients. In this paper, we derive a formula to quantify the power coefficient of different devices. Specifically, this formula covers ducted devices, and it suggests that the duct shape should be considered. We also propose a procedure to quantify the efficiency of a tidal current turbine farm by using the power output of the farm where no hydrodynamic interaction exists between turbines, which normalizes a given farm's power output. We also show that the maximum efficiency of a farm can be obtained when the hydrodynamic interaction exists.     

An analysis of subsynchronous resonance in hybrid marine current and wind farms with squirrel cage induction generator

Subsynchronous resonance (SSR) is a well-known phenomenon in series-compensated systems with synchronous generators. With the rapid growth of renewable energy systems, it is likely that with its integration to series-compensated system for the transmission of bulk power may lead to the problem of SSR. This paper conducts an analysis of SSR phenomena in the squirrel cage induction generator-based hybrid wind farm and marine current farm connected to series-compensated system with power variation due to the addition or removal of small turbine units. A dynamic model has been developed to analyse the induction generator effect and torsional interaction of SSR on the IEEE first bench mark model for SSR studies. The eigenvalue analysis was performed on the developed model with MATLAB and the time domain electro magnetic transient simulation performed on DiGSILENT Power Factory confirms the predicted results by the eigenvalue analysis.     

Experimental study of the turbulence intensity effects on marine current turbines behaviour. Part I: One single turbine

The ambient turbulence intensity in the upstream flow plays a decisive role in the behaviour of horizontal axis marine current turbines.Experimental trials, run in the IFREMER flume tank in Boulogne-Sur-Mer (France) for two different turbulence intensity rates, namely 3% and 15%, are presented. They show, for the studied turbine configuration, that while the wake of the turbine is deeply influenced by the ambient turbulence conditions, its mean performances turn out to be slightly modified.The presented conclusions are crucial in the view of implanting second generation turbines arrays. In addition, complete and detailed data sets (wake profiles and performance graphs) are made available to the scientific community in order to encourage further comparisons.     

Effects of blade geometry on performance of wells turbine for wave power conversion

IntroductionThe fossil fuel energy with the problem of airpollution might run out by the middle of the 21stcentury. So many researchers have studied forscores of years on alternative, renewable energysources11] such as tidal, wave, salinity gradient,current, wind and solar energy.The energy density level of waves is higherthan the other energy sources stated above. Thereare various techniques for extraction of energyfrom waves[2]. Several of the wave energydevices using the principle of an os…     

Design of bare and ducted axial marine current turbines

To convert the kinetic energy of marine current into electricity, the most sensible generator is a horizontal axis turbine. The know-how and the tools used for marine propulsion devices find a new range of applications in this field. An academic panel method code developed for the design of bare and ducted marine propellers was applied to design a marine current turbine. The turbine dimension and the tidal current velocity have been taken to fit the conditions in the Race of Alderney. The wing section theory and the optimum rotor theory based on the blade element momentum were used to obtain the design condition and a first geometry approaching the Betz limit for a bare rotor. The panel method was then used to verify the power coefficient obtained in the presence of the 3D effects and if the cavitation constraints are respected. Subsequently, the same panel code was used to verify if the addition of a duct could improve the power output per unit surface.