热能与动力工程专业英语译文第二章.doc

Chapter 2 Boiler 2.1 Introduction Boilers use heat to convert water into steam for a variety of applications. Primary among these are electric power generation and industrial process heating. Steam has become a key resource because of its wide availability, advantageous properties and nontoxic nature. 锅炉利用热量使水转变成蒸汽以进行各种利用。其中主要是发电和工业供热。由于蒸汽具有有利的参数和无毒特性，因此蒸汽作为一种关键的工质（资源）被广泛的应用。 The steam flow rates and operating conditions can vary dramatically: from 1000 lb/h (0.126kg/s) in one process use to more than 10 million lb/h (1260kg/s) in large electric power plants; from about 14.7 psi (1 bar) and 212℉(100℃) in some heating applications to more than 4500 psi (310 bar ) and 1100℉(593℃) in advanced cycle power plant 蒸汽流量和运行参数的变化很大：从某一过程里1000磅/小时（0.126kg/s）到大电厂超过10×106磅/小时（1260 kg/s），压力从一些加热应用的14.7 psi (1.0135bar), 212 ℉ （100℃）到先进循环电厂的4500 psi （310bar）1100 ℉ （593℃）。 Modern steam generating systems can be classified by various criteria. These include end use, firing method, operating pressure, fuel and circulation method. 现代蒸汽发生系统可根据不同的标准分类。这些包括最终用途、燃烧方式、运行压力、燃料和循环方式。 Utility boilers are used primarily to generate electricity in large central power stations. They are designed to optimise overall thermodynamic efficiency at the highest possible availability. A key characteristic of newer units is the use of a reheater section to increase overall cycle efficiency. 大型中心电站的电站锅炉主要用来发电。经过优化设计，使最大可能可用性时有最高的热效率。新机组的关键特性是利用再热器提高整个循环效率。 Other steam producing systems A variety of additional systems also produce steam for power and process applications. These systems usually take advantage of low cost or free fuels, a combination of power cycles and processes, and recovery of waste heat in order to reduce overall costs. Examples of these include: 各种附加的系统也产生蒸汽用于发电及过程应用。这些系统常常利用廉价或免费燃料，联合动力循环和过程，余热回收以减少总费用。这些例子包括： Gas turbine combined cycle (CC) Advanced gas turbines with heat recovery steam generators as part of a bottoming cycle to use waste heat recovery and increase