Lesson-9-Marine-Boilers.doc

Lesson 9 Marine Boilers第9课 船用锅炉1. Boilers are used on board ship for producing steam. This steam may be used for driving the main engines, when steam turbines are fitted, or for driving auxiliary machinery such as the windlass. There are two basic types of boiler in use in ships: the fire-tube boiler the （terms “smoke tube” and “donkey boiler” are also in use), and the water-tube boiler. Both are illustrated in Fig. 9-1船用锅炉用来产生蒸汽。蒸汽在装有蒸汽轮机的船上可用于驱动主机，也可用于驱动辅助机械，如锚机。船用锅炉有两种基本类型：火管锅炉（也使用“烟管锅炉”和“辅锅炉”这两个术语）和水管锅炉。分别图示如下9-1。2. Now if you look at the diagram of the fire-tube boiler you will see that it consists of a cylindrical steel shell, which contains a furnace at the bottom. Two or more furnaces may be fitted, depending on the size of the boiler. The furnace is connected to a combustion chamber, situated in the middle part of the boiler. Leading from this combustion chamber to a smoke box are a large number of horizontal tubes. Some of these are used for supporting the middle section of the boiler and the combustion chamber. Connected to the smoke box are the uptakes for the waste gases. The furnace, the combustion chamber and the tubes are all surrounded by water.在火管锅炉的图中可以看到，它由一个圆筒形的钢外壳构成，其底部有炉膛。根据锅炉的大小，可以安装两个或更多的炉膛。炉膛和位于锅炉中间位置的燃烧室相通。燃烧室和烟箱之间设有许多水平烟管。一部分烟管用来支撑锅炉中部和燃烧室。与烟箱相连的是废气的上升烟道。炉膛、燃烧室和烟管都被水包围着。3.The fire-tube boiler is usually of both riveted and welded construction. It is strong and is capable of operating with poor quality feed water. But there are more efficient types of boiler, which can generate more power; therefore fire-tube boilers are now mainly chosen for low-pressure steam production on vessels requiring steam for auxiliary purposes.火管锅炉一般为铆接和焊接结构，结构坚固，能够使用劣质给水工作。但是，有些类型的锅炉效率更高，能够产生更大量的蒸汽；因此，苏格兰式锅炉(火管锅炉)现在主要为需要蒸汽驱动辅助机械的船舶提供低压蒸汽。4.Water-tube boilers have replaced fire-tube boilers for generating high-pressure, high-temperature, high-capacity steam for main engines or cargo pump turbines. From the diagram you will see that they have a steam drum at the top, which is partly filled with water, and water drums at a lower level. These drums are connected by banks of tubes, which also contain water. The furnace is located at the bottom and the whole system is contained in a fireproof casing. Downcomer tubes are placed outside the gas system to act as feeders to the water drums.水管锅炉已经取代了火管锅炉，产生高压高温大流量的蒸汽，以驱动主机或货油泵透平。从图上可以看到，水管锅炉的顶部有一个汽鼓，部分注水；下部有多个水鼓。汽鼓和水鼓由管束连接，管内有水。炉膛位于底部，整个系统由耐火外壳包围。下降管安装在燃气系统之外，用作水鼓的给水管。5.Gases are heated in the furnace and pass upwards through the banks of tubes, transferring their heat to the water in the tubes. Because the steam drum provides a reservoir of relatively cool water, convection currents are set up causing the water to circulate round the system. The banks of tubes (generating tubes) offer a large surface area to the radiant heat of the furnace gases. This makes them very efficient. Superheaters are added to the system to increase its efficiency. These are located between the rows of tubes.在炉膛内加热的燃气向上通过管束，将热量传递给管内的水。因为汽鼓里存储的水温度相对较低，系统内就形成对流，使水得以循环。管束（蒸发管）提供了一个较大的炉膛燃气辐射受热面，使蒸发效率很高。过热器加装到系统中，进一步提高了效率，它们一般设置在管排间。6.Various valves and gauges are fitted to the boilers. Those attached directly to the pressure parts of the boiler are known as boiler mountings. The mountings usually found on a boiler are: safety valves, which are needed to protect the boiler against overpressure; a main s top valve in order to control the passage of steam to the engines; feed check valves to control the final entry of water into the boiler; water level indicators to show the level of water in the boiler; a blow down valve enables water to be blown down or emptied from the boiler; a scum valve enables the blowing down or removal of scum and impurities from the water surface and thermometers for showing the temperature inside the boiler. In order to be able t o blow away soot and the products of combustion from the tube surfaces, soot blowers are fitted which are operated by steam or compressed air. Salinometer valves are also fitted to allow samples of water to be drawn off for testing. Chemical dosing valves are also necessary so that chemicals can be added directly into the boiler锅炉上装有各种阀和测量仪表。直接与锅炉压力部件相连的称为锅炉附件。通常的锅炉附件有：防止锅炉超压的安全阀，控制通向发动机的蒸汽的主停汽阀，控制锅炉进水量的给水止回阀，显示锅炉水位的水位指示器，排出或放空锅炉水的下排污阀，排出或除去水面浮渣和杂质的上排污阀，以及显示锅炉内部温度的温度计。为了吹除管壁上的烟灰和燃烧产物，安装了用蒸汽或压缩空气工作的吹灰器。盐度计阀（取样阀）也安装在锅炉上，以便可以提取样水进行检测。还需要安装投药阀，这样化学制剂就能直接加入锅炉中。B.Multiple Choice B.选择题Questions 1-3 are based on paragraphs 1-3. 根据课文第，1-3段回答问题，1-31.Marine boilers are used for producing steam which may be used for . 船用锅炉产生的蒸汽是用来_。答案;DA.driving auxiliary machinery驱动辅机B.driving the main engines驱动主机C.heating heavy oil加热重油D.all of the above上述任何一种2.A fire-tube boiler comprises the following components except . 火管锅炉包括以下部件，除了_。答案:BA. uptakes上升烟道B. downcomers下降管C. a smoke box烟箱D. furnaces炉膛3.Which of the following statements is not true concerning a fire-tube boiler? 关于火管锅炉以下哪种说法是不正确的?答案;CA.The fire-tube boiler is usually of both riveted and welded construction. 火管锅炉通常兼有铆合和焊接两种结构。B.It can operate with poor quality feed water. 火管锅炉能够使用劣质给水运行。C.It is the most efficient type of boilers. 火管锅炉是最有效率的一种锅炉。D.It is now mainly chosen for low-pressure steam production. 火管锅炉现在主要用来产生低压蒸汽Questions 4-7 are based on paragraphs 4-5.根据课文第4-5段回答问题4-74.In a boiler the water flows through the inside of the tubes while the hot gases pass around the outside4. 在_锅炉中，水流经管内而炽热烟气从管外通过。答案.AA. water-tub烟管B. fire-tubee水管C. exhaust gas废气D. none of the above以上都不是5.Gases are heated in the furnace and pass upwards through , which offer a large surface area to the radiant heat of the furnace gases. 燃气在炉膛内被加热上行经过，它给炉膛燃气提供了很大的辐射受热面积。 答案:CA. the uptakes上升烟道B. the downcomers下降管C. the banks of tubes管束(蒸发管)D. the smoke boxes烟箱6.A water-tube boiler may have the following components except . .水管锅炉可能包括以下部件，除了_。答案.AA.the smoke box烟箱B.the downcomers下降管C.the generating tubes蒸发管D.the water drums and the steam drum水鼓和汽鼓7.Which of the following components may increase the boiler efficiency? 下列哪种部件可能提高锅炉效率答案:AA. The superheaters. 过热器B. The downcomers. 下降管C. The steam drum. 汽鼓 D. The water drums. 水鼓Questions 8 -13 are based on paragraph 6.根据课文第6段回答问题8-138.The valve that prevents water from backing out the boiler into the feedline is the . 阻止从锅炉返回的水进人给水管路的是_。答素.CA. bottom-blow valve下排污阀B. skin valve皮肤阀C. feed check valve给水止回阀D. feed-stop valve截止阀9. enables the blowing down or removal of scum and impurities from the water surface.9._可以除掉水面的浮渣和杂质。答素:DA. A blow-down valve下排污阀B. A soot blower.吹灰器C. A feed check valve给水止回阀D. A scum valve上排污阀10.The is fitted in the steam supply line and is usually of the non-return type_安装在供汽管上并且通常是止回型的。答素;A.A. main steam stop valve主停汽阀B. auxiliary steam stop valve辅停汽阀C.feed check or control valve给水止回/控制阀 D. blow-down valve下排污阀.11. are also fitted to allow samples of water to be drawn off for testing the chlorides. _也被安装，使得水样得以提取来检测氯化物。答素.AA. Salinometer valves盐度计阀 B. Water level gauges水位计C.Viscometers 黏度计 D. Tachometers转速表12. are mounted in pairs to protect the boiler against overpressure. _成对安装以保护锅炉免于超压。答素.AA. Safety valves安全阀 B. Water tubes水管C.Steam stop valves 停汽阀 D. Blow-down valves下排污阀13. enables water to be blown down or emptied from the boiler. 使水从锅炉中放出或者排空。答案;CA. A scum valve上排污阀 B. A soot blower吹灰器C.A blow-down valve 下排污阀 D. A vent cock放气阀Task 2 Vocabulary and Structure任务2词汇与结构A. Technical Terms专业术语Translate the following into Chinese.1.烟箱 2.燃烧室 3.汽鼓 4.水鼓5.下降管 6.蒸发管 7.过热器 8.安全阀9.主停汽阀 10.给水阀 11.水位计 12.上排污阀13.吹灰器 14.盐度计阀 15投药阀1.smoke bustion