汽轮机技术的历史
History of steam turbine technology
Early precursors
The first device that can be classified as a reaction steam turbine is the aeolipile proposed by Hero of Alexandria, during the 1st century ce. In this device, steam was supplied through a hollow rotating shaft to a hollow rotating sphere. It then emerged through two opposing curved tubes, just as water issues from a rotating lawn sprinkler. The device was little more than a toy, since no useful work was produced.
可以归类为反应蒸汽轮机的第一台设备是 汽转球提出希罗1世纪时,行政长官。在该装置中,蒸汽通过空心旋转轴供应到空心旋转球。然后,水从两个相对的弯曲管中流出,就像旋转的草坪洒水喷出的水一样。该设备只不过是玩具,因为没有进行任何有用的工作。
Another steam-driven machine, described in 1629 in Italy, was designed in such a way that a jet of steam impinged on blades extending from a wheel and caused it to rotate by the impulse principle. Starting with a 1784 patent by James Watt, the developer of the steam engine, a number of reaction and impulse turbines were proposed, all adaptations of similar devices that operated with water. None were successful except for the units built by William Avery of the United States after 1837. In one such Avery turbine two hollow arms, about 75 centimetres long, were attached at right angles to a hollow shaft through which steam was supplied. Nozzles at the outer end of the arms allowed the steam to escape in a tangential direction, thus producing the reaction to turn the wheel. About 50 of these turbines were built for sawmills, cotton gins, and woodworking shops, and at least one was tried on a locomotive. While the efficiencies matched those of contemporary steam engines, high noise levels, difficult speed regulation, and frequent need for repairs led to their abandonment.
另一台蒸汽驱动的机器(于1629年在意大利描述)的设计方式是使蒸汽射流撞击从轮子延伸的叶片上,并根据脉冲原理使其旋转。与1784专利通过启动詹姆斯·瓦特,该开发商蒸汽机,一些反应和冲击式涡轮机的提出,所有的修改与水操作类似装置。除了由1837年后的美国威廉·艾弗里(William Avery)。 Avery涡轮机的两个空心臂(长约75厘米)以直角安装在空心轴上,蒸汽通过空心轴供应。臂外端的喷嘴使蒸汽沿切线方向逸出,从而产生使车轮转动的反作用力。这些涡轮机中约有50台是为锯木厂,轧花厂和木工车间建造的,至少有一台在机车上试用过。尽管效率与现代蒸汽机相当,但噪音高,调速困难以及维修频繁,导致人们放弃了这种效率。
Development of modern steam turbines
No further developments occurred until the end of the 19th century when various inventors laid the groundwork for the modern steam turbine. In 1884 Sir Charles Algernon Parsons, a British engineer, recognized the advantage of employing a large number of stages in series, allowing extraction of the thermal energy in the steam in small steps. Parsons also developed the reaction-stage principle according to which a nearly equal pressure drop and energy release takes place in both the stationary and moving blade passages. In addition, he subsequently built the first practical large marine steam turbines. During the 1880s Carl G.P. de Laval of Sweden constructed small reaction turbines that turned at about 40,000 revolutions per minute to drive cream separators. Their high speed, however, made them unsuitable for other commercial applications. De Laval then turned his attention to single-stage impulse turbines that used convergent-divergent nozzles, such as the one shown in Figure 3. From 1889 to 1897 de Laval built many turbines with capacities from about 15 to several hundred horsepower. His 15-horsepower turbines were the first employed for marine propulsion (1892). C.E.A. Rateau of France first developed multistage impulse turbines during the 1890s. At about the same time, Charles G. Curtis of the United States developed the velocity-compounded impulse stage.
现代蒸汽轮机的发展
直到19世纪末,各种发明者为现代蒸汽轮机奠定了基础,才有了进一步的发展。1884年英国工程师Charles Algernon Parsons爵士认识到串联使用大量级的优势,从而可以分步提取蒸汽中的热能。帕森斯还发展了反应阶段原理,根据该原理,固定和移动叶片通道中的压降和能量释放几乎相等。此外,他随后建造了第一个实用的大型海洋蒸汽涡轮机。在1880年代瑞典卡尔·拉瓦尔(Carl GP de Laval)修建了小型反应堆涡轮以每分钟40,000转的速度旋转以驱动奶油分离器。但是,它们的高速度使其不适用于其他商业应用。然后,德拉瓦勒将注意力转向使用会聚-发散喷嘴的单级脉冲式涡轮机,如图3所示。从1889年到1897年,德拉瓦勒制造了许多涡轮机,容量从15马力到几百马力。他的15马力涡轮机是最早用于船舶推进的涡轮机(1892年)。法国的CEA Rateau在1890年代首先开发了多级脉冲涡轮机。大约在同一时间,美国的查尔斯·柯蒂斯(Charles G. Curtis)开发了速度复合的脉冲级。
By 1900 the largest steam turbine-generator unit produced 1,200 kilowatts, and 10 years later the capacity of such machines had increased to more than 30,000 kilowatts. This far exceeded the output of even the largest steam engines, making steam turbines the principal prime movers in central power stations after the first decade of the 20th century. Following the successful installation of a series of 68,000-horsepower turbines in the transatlantic passenger liners Lusitania and Mauretania, launched in 1906, steam turbines also gained preeminence in large-scale marine applications, first with vessels burning fossil fuels and then with those using nuclear power. Steam generator pressures increased from about 1,000 kilopascals gauge in 1895 to 1,380 kilopascals gauge by 1919 and then to 9,300 kilopascals gauge by 1940. Steam temperatures climbed from about 180 °C (saturated steam) to 315 °C (superheated steam) and eventually to 510 °C over the same time period, while heat rates decreased from about 38,000 to below 10,000 Btus per kilowatt-hour.
到1900年,最大的蒸汽轮发电机组产生了1200千瓦,而十年后,这种机器的容量已增加到30,000千瓦以上。这远远超过了甚至最大的蒸汽机的产量,使蒸汽轮机成为20世纪前十年后中央电站的主要原动力。在1906年启动的跨大西洋客轮Lusitania和Mauretania成功安装了一系列68,000马力的涡轮机之后,蒸汽轮机也获得了大规模的应用在海上应用中,首先是使用燃烧化石燃料的船只,然后是使用核能的船只。蒸汽发生器的压力从1895年的约1000千帕斯卡升高到1919年的1380千帕斯卡,然后到1940年增至9300千帕斯卡。蒸汽温度从约180°C(饱和蒸汽)升至315°C(过热蒸汽),最终升至510。相同时间段的摄氏温度,而热效率从每千瓦时38,000降低到10,000 Btus以下。
Recent developments and trends
By 1940, single turbine units with a power capacity of 100,000 kilowatts were common. Ever-larger turbines (with higher efficiencies) have been constructed during the last half of the century, largely because of the steadily rising cost of fossil fuels. This required a substantial increase in steam generator pressures and temperatures. Some units operating with supercritical steam at pressures as high as 34,500 kilopascals gauge and at temperatures of up to 650 °C were built before 1970. Reheat turbines that operate at lower pressures (between 17,100 to 24,100 kilopascals gauge) and temperatures (540–565 °C) are now commonly installed to assure high reliability. Steam turbines in nuclear power plants, which are still being constructed in a number of countries outside of the United States, typically operate at about 7,580 kilopascals gauge and at temperatures of up to 295 °C to accommodate the limitations of reactors. Turbines that exceed one-million-kilowatt output require exceptionally large, highly alloyed steel blades at the low pressure end.
到1940年,功率为100,000千瓦的单涡轮机已经很普遍。在本世纪后半叶,建造了越来越大的涡轮机(效率更高),这主要是由于化石燃料的价格不断上涨。这需要大量增加蒸汽发生器压力和温度。在1970年前建造了一些使用超临界蒸汽,压力高达34,500千帕斯卡,温度高达650°C的机组。在较低压力(17,100至24,100千帕斯卡之间)和温度(540–565°C)下运行的再热涡轮机C)现在通常安装以确保高可靠性。在美国以外的许多国家/地区中仍在建造的核电站蒸汽轮机通常在约7580千帕的压力下运行,最高温度为295°C,以适应反应堆的限制。功率超过一百万千瓦的涡轮机在低压端需要非常大的高合金钢叶片。
Slightly more efficient units with a power capacity of more than 1.3 million kilowatts may eventually be built, but no major improvements are expected within the next few decades, primarily because of the temperature limitations of the materials employed in steam generators, piping, and high-pressure turbine components and because of the need for very high reliability.
最终可能会制造出效率更高的机组,功率容量超过130万千瓦,但在未来几十年内,预计不会有重大改进,这主要是因为蒸汽发生器,管道和高功率蒸汽炉所用材料的温度限制。并且由于需要非常高的可靠性。
Although the use of large steam turbines is tied to electric power production and marine propulsion, smaller units may be used for cogeneration when steam is required for other purposes, such as for chemical processing, powering other machines (e.g., compressors of large central air-conditioning systems serving many buildings), or driving large pumps and fans in power stations or refineries. However, the need for a complete steam plant, including steam generators, pumps, and accessories, does not make the steam turbine an attractive power device for small installations.
尽管大型蒸汽轮机的使用与电力生产和船舶推进相关,但是当需要蒸汽用于其他目的(例如用于化学处理,为其他机器(例如,大型中央空调的压缩机)提供动力)时,较小的单元可以用于热电联产用于许多建筑物的空调系统),或在电站或精炼厂中驱动大型泵和风机。但是,对于包括蒸汽发生器,泵和配件在内的完整的蒸汽设备的需求,并未使蒸汽轮机成为小型设备的有吸引力的动力装置。