外文翻译--风能介绍

附录 英文文献 Wind Energy Introduction 1.1 Historical Development Windmills have been used for at least 3000 years, mainly for grinding grain or pumping water, while in sailing ships the wind has been an essential source of power for even longer. From as early as the thirteenth century, horizontal-axis windmills were an integral part of the rural economy and only fell into disuse with the advent of cheap fossil-fuelled engines and then the spread of rural electrification.The use of windmills (or wind turbines) to generate electricity can be traced back to the late nineteenth century with the 12 kW DC windmill generator constructed by Brush in the USA and the research undertaken by LaCour in Denmark. However, for much of the twentieth century there was little interest in using wind energy other than for battery charging for remote dwellings and these low-power systems were quickly replaced once access to the electricity grid became available. One notable exception was the 1250 kW SmithPutnam wind turbine constructed in the USA in 1941. This remarkable machine had a steel rotor 53 m in diameter, full-span pitch control and flapping blades to reduce loads. Although a blade spar failed catastrophically in 1945, it remained the largest wind turbine constructed for some 40 years (Putnam, 1948). Golding (1955) and Shepherd and Divone in Spera (1994) provide a fascinating history of early wind turbine development. They record the 100 kW 30 m diameter Balaclava wind turbine in the then USSR in 1931 and the Andrea Enfield 100 kW 24 m diameter pneumatic design constructed in the UK in the early 1950s. In this turbine hollow blades, open at the tip, were used to draw air up through the tower where another turbine drove the generator. In Denmark the 200 kW 24 m diameter Gedser machine was built in 1956 while Electricite de France tested a 1.1 MW 35 m diameter turbine in 1963. In Germany, Professor Hutter constructed a number of innovative, lightweight turbines in the 1950s and 1960s. In spite of these technical advances and the enthusiasm, among others, of Golding at the Electrical Research Association in the UK there was little sustained interest in wind generation until the price of oil rose dramatically in 1973. The sudden increase in the price of oil stimulated a number of substantial Government-funded programme of research, development and demonstration. In the USA this led to the construction of a series of prototype turbines starting with the 38 m diameter 100 kW Mod-0 in 1975 and culminating in the 97.5 m diameter 2.5 MW Mod-5B in 1987. Similar programme were pursued in the UK, Germany and Sweden. There was considerable uncertainty as to which architecture might prove most cost-effective and several innovative concepts were investigated at full scale. In Canada, a 4 MW vertical-axis Darrieus wind turbine was constructed and this concept was also investigated in the 34 m diameter Sandia Vertical Axis Test Facility in the USA. In the UK, an alternative vertical-axis design using straight blades to give an H type rotor was proposed by Dr Peter Musgrove and a 500 kW prototype constructed. In 1981 an innovative horizontal-axis 3 MW wind turbine was built and tested in the USA. This used hydraulic transmission and, as an alternative to a yaw drive, the entire structure was orientated into the wind. The best choice for the number of blades remained unclear for some while and large turbines were constructed with one, two or three blades. Much important scientific and engineering information was gained from these Government-funded research programmes and the prototypes generally worked as designed. However, it has to be recognized that the problems of operating very large Figure 1.1 1.5 MW, 64 m diameter Wind Turbine (Reproduced by permission of NEG MICON) wind turbines, unmanned and in difficult wind climates were often under- estimated and the reliability of the prototypes was not good. At the same time as the multi-megawatt prototypes were being constructed private companies, often with considerable state support, were constructing much smaller, often simpler,turbines for commercial sale. In particular the financial support mechanisms in California in the mid-1980s resulted in the installation of a very large number of quite small(100 kW) wind turbines. A number of these designs also suffered from various problems but, being smaller, they were in general easier to repair and modify. The so-called Danish wind turbine concept emerged of a three-bladed,stall-regulated rotor and a fixed-speed, induction machine drive train. This decep-tively simple architecture has proved to be remarkably successful and has now been implemented on turbines as large as 60 m in diameter and at ratings of 1.5 MW. The machines of Figures 1.1 and 1.2 are examples of this design. However, as the sizes of commercially available turbines now approach that of the large prototypes of the 1980s it is interesting to see that the concepts investigated then of variable-speed operation, full-span control of the blades, and advanced materials are being used increasingly by designers. Figure 1.3 shows a wind farm of direct-drive, variable-speed wind turbines. In this design, the synchronous generator is coupled directly to the aerodynamic rotor so eliminating the requirement for a gearbox. Figure 1.4 shows a more conventional, variable-speed wind turbine that uses a gearbox, while a small wind farm of pitch-regulated wind turbines, where full-span control of the blades is used to regulate power, is shown in Figure 1.5. Figure 1.2 750 kW, 48 m diameter Wind Turbine, Denmark (Reproduced by permission of NEG MICON) Figure 1.3 Wind Farm of Variable-Speed Wind Turbines in Complex Terrain (Reproduced by permission of Wind Prospect Ltd) Figure 1.4 1 MW Wind Turbine in Northern Ireland (Reproduced by permission of Renew-able Energy Systems Ltd) The stimulus for the development of wind energy in 1973 was the price of oil and concern over limited fossil-fuel resources. Now, of course, the main driver for use of wind turbines to generate electrical power is the very low C 错误 !未找到引用源。 emissions (over the entire life cycle of manufacture, installation, operation and de-commissioning) Figure 1.5 Wind Farm of Six Pitch-regulated Wind Turbines in Flat Terrain (Reproduced by permission of Wind Prospect Ltd) and the potential of wind energy to help limit climate change. In 1997 the Commis-sion of the European Union published its White Paper (CEU, 1997) calling for 12 percent of the gross energy demand of the European Union to be contributed from renewables by 2010. Wind energy was identified as having a key role to play in the supply of renewable energy with an increase in installed wind turbine capacity from 2.5 GW in 1995 to 40 GW by 2010. This target is likely to be achievable since at the time of writing, January 2001, there was some 12 GW of installed wind-turbine capacity in Europe, 2.5 GW of which was constructed in 2000 compared with only 300 MW in 1993. The average annual growth rate of the installation of wind turbines in Europe from 1993-9 was approximately 40 percent (Zervos, 2000). The distribution of wind-turbine capacity is interesting with, in 2000, Germany account- ing for some 45 percent of the European total, and Denmark and Spain each having approximately 18 percent. There is some 2.5 GW of capacity installed in the USA of which 65 percent is in California although with increasing interest in Texas and some states of the midwest. Many of the California wind farms were originally constructed in the 1980s and are now being re-equipped with larger modern wind turbines. Table 1.1 shows the installed wind-power capacity worldwide in January 2001 although it is obvious that with such a rapid growth in some countries data of this kind become out of date very quickly. The reasons development of wind energy in some countries is flourishing while in others it is not fulfilling the potential that might be anticipated from a simple consideration of the wind resource, are complex. Important factors include the financial-support mechanisms for wind-generated electricity, the process by which the local planning authorities give permission for the construction of wind farms,and the perception of the general population particularly with respect to visual impact. In order to overcome the concerns of the rural population over the environ-mental impact of wind farms there is now increasing interest in the development of sites offshore. 1.2 Modern Wind Turbines The power output, P, from a wind turbine is liven by the well-known expression: P=错误 !未找到引用源。 where is the density of air (1.225 kg/错误 !未找到引用源。 ), 错误 !未找到引用源。 is the power coefficient, A is the rotor swept area, and U is the wind speed. The density of air is rather low, 800 times less than that of water which powers hydro plant, and this leads directly to the large size of a wind turbine. Depending on the design wind speed chosen, a 1.5 MW wind turbine may have a rotor that is more than 60 m in diameter. The power coefficient describes that fraction of the power in the wind that may be converted by the turbine into mechanical work. It has a theoretical maximum value of 0.593 (the Betz limit) and rather lower peak values are achieved in practice (see Chapter 3). The power coefficient of a rotor varies with the tip speed ratio (the ratio of rotor tip speed to free wind speed) and is only a maximum for a unique tip speed ratio. Incremental improvements in the power coefficient are continually being sought by detailed design changes of the rotor and, by operating at variable speed, it is possible to maintain the maximum power coefficient over a range of wind speeds. However, these measures will give only a modest increase in the power output. Major increases in the output power can only be achieved by increasing the swept area of the rotor or by locating the wind turbines on sites with higher wind speeds. Hence over the last 10 years there has been a continuous increase in the rotor diameter of commercially available wind turbines from around 30 m to more than 60 m. A doubling of the rotor diameter leads to a four-times increase in power output. The influence of the wind speed is, of course, more pronounced with a doubling of wind speed leading to an eight-fold increase in power. Thus there have been considerable efforts to ensure that wind farms are developed in areas of the highest wind speeds and the turbines optimally located within wind farms. In certain countries very high towers are being used (more than 60-80 m) to take advantage of the increase of wind speed with height. In the past a number of studies were undertaken to determine the optimum size of a wind turbine by balancing the complete costs of manufacture, installation and operation of various sizes of wind turbines against the revenue generated (Mollyet al. 1993). The results indicated a minimum cost of energy would be obtained with wind turbine diameters in the range of 35-60 m, depending on the assumptions made. However, these estimates would now appear to be rather low and there is no obvious point at which rotor diameters, and hence output power, will be limited particularly for offshore wind turbines. All modern electricity-generating wind turbines use the lift force derived from the blades to drive the rotor. A high rotational speed of the rotor is desirable in order to reduce the gearbox ratio required and this leads to low solidity rotors (the ratio of blade area/rotor swept area). The low solidity rotor acts as an effective energy concentrator and as a result the energy recovery period of a wind turbine, on a good site, is less than 1 year, i.e., the energy used to manufacture and install the wind turbine is recovered within its first year of operation (Musgrove in Freris, 1990). 英文翻译 风能介绍 1.1 发展历史 风车的使用至少已有三千年，主要用于磨粒或泵站水，而在帆船风已成为不可缺少的电力来源甚至更 长的一段时间。从早在 13 世纪，水平轴风力发电的一个组成部分是农村经济，只有随着廉价的矿物燃料的引擎落入废弃，农村电气化才蔓延出来。利用风力发电（或风力发电机）发电可以追溯到十九世纪末期的12 千瓦直流风力发电机，建造在美国的丹麦 LaCour 研究所。然而， 20 世纪大部分时期人们对使用风能没有兴趣，除了用于偏远住宅电力供应，并且一旦并入电网成为可能，这些低功耗系统很快就被取代。一个突出的例子是 1941 年史密斯普特南在美国建造的 1250 千瓦的风力发电机组，这台机组刚性转子直径是 53米，充分跨度间距控制和扑叶片，以减 少负载。虽然这种叶片风机在 1945 年失败了，但是它仍然是最大的风机在之后的约 40 年间。 Golding (1955 年 ),Shepherd 和 Divone 在 Spera （ 1994 ）提供了一个令人着迷的早期风力发电机的发展史。 1931 年他们记录了 100 千瓦 30 米直径的苏联巴拉克拉风力发电机组和 1950 年代初英国 Andrea Enfield 100 千瓦 24 米直径风力发电机组的气动设计建造。在这空心涡轮叶片，展开着，被用来吸收空气动能透过机身推动另一端的发电机， 1956年在丹麦生产出了 200千瓦 24米直径 Gedser机型，而后，在 1963 年法国的一家电力公司已完成了 1.1 兆瓦 35 米直径风力发电机的测试。五十年代和六十年代，德国的 Hutter 教授有了一些轻型涡轮机的创新。尽管有这些技术进步和研究热情，等等，但是 Golding 在英国的电气研究协会对风力机很少有持续的兴趣直到 1973 年石油价格显著上升时。 突然增加的石油价格刺激了一些实质性的政府资助方案的研究 , 开发和示范。 1975 年，这直接导致美国设计了以 100 千瓦 38 米直径 0 型风机为开始的一系列风机模型，并且最终在 1987 年设计出 2.5 兆瓦 97.5 米直径 5B 的风力机 模型。类似的方案同样在英国，德国和瑞典受到热捧。由于这些设计在最符合成本效益和一些创新的概念方面可能会有不确定性，因此，需要对其进行充分规模的调查。在加拿大，生产出了一台 4 兆瓦垂直轴 Darrieus 型风力机， 并且这种 概念也在美国和英国的 34 米直径 Sandia 垂直轴试验设备中进行测试， Peter Musgrove博士提出使用直叶片做出的 H 型转子替代垂直轴的设计建造了一个 500 千瓦的样机。 1981 年美国的一台创新型 3 兆瓦水平轴的风力发电机组被生产出来并进行了测试。它使用液压传动以用来替代偏航驱动器，使整个结构导 向对风。叶片数量最好的选择在某些方面仍然不是很明确，基本上大的风机都是使用单叶片，双叶片或者是三叶片。 许多重要的科学和工程信息都是从这些政府资助的研究方案和一般的原型设计工作中获得的。但是，必须认识到运行一个没有人工操作，大型的风力机的问题，这种恶劣的风气候经常是不可估计的，并且设备的可靠性不是很好。同时，多兆瓦的风机也在私人的公司中建造，往往相当多的国家支持，建设要小得多，往往很简单的风力机作为商业销售。 20 世纪 80 年代中期在加利福尼亚州，特别 是财政支持机制催生了大量小型（ 100 千瓦）风力发电机的安装。 其中的一些设 计也有遇到了各种各样的问题，但是由于是小型的，可以利用普通简便的方法来修理和改进，所谓的 Danish 风力机概念出现了三叶片，失速调节转子和一个恒定的速率，感应电机驱动。这个简单的架构已被证明是非常成功的，并且有现在60 米直径风力机一样大的直径和 1.5 兆瓦的功率。图 1.1 和图 1.2 这种设计的两个例子。然而，随着商用风力机的规模引用 20 世纪 80 年代的大型模型成为可能，有趣的是看到当时变速操作的概念调查，充分跨度控制叶片和增强的材料越来越多的被设计者使用到。图 1.3 显示了一个采用变速直趋的风力机的风 场。在 图 1.1 1.5 兆瓦， 64 米直径风力机 这种设计中，同步发电机是直接耦合的气动转子，所以这样的就不需要齿轮变速箱了，图 1.4 显示了一个更传统，使用变速齿轮箱的变速风力机，而一个小风电场的音高调节风力发电机，叶片充分跨度控制是用来限制功率的，如图 1.5。 图 1.2 750 千瓦， 48 米直径风力机 图 1.3 在复杂地形上的变速调节风力发电场 图 1.4 北爱尔兰 1 兆瓦风力发电机 刺激风力发电发展的是 1973 年的石油价格和对有限的化石燃料资源的关注，利用风力发电机发电的主要驱动力量 是非常低的二氧化碳排放量（在制造，安装，操作和去调试的整个生命周期）和用来帮助限制气候变化影响的风能的潜力。 1997 年，欧洲联盟委员会出版了名为欧盟成员国在 2010 年 12%的能源需求将从可再生能源中获得的白皮书。 随着从 1995 年已安装的容量为 2.5 万千瓦的风力发电机组到 2010 年的 40 万千瓦这样的增长，风力发电已被确定为在可再生能源供应方面可发挥关键作用。这个目标是可能实现的，因为在