Lesson 1 Types of Diesel Engine.doc

Lesson 1 Types of Diesel Engine第1课柴油机的种类1. The invention of the diesel engine in 1892 has been attributed to Rudolf Diesel, a German mechanical engineer and inventor. Since then diesel engines have played an important role in the shipping industry because of their improved engine efficiencies and designs compared to other forms of propulsion such as steam or gas turbines. Diesel engines are known by the name of compression ignition engines due to technical reasons. There are several ways of classification of diesel engines based on various parameters. According to their speeds, diesel engines may be divided into three types: slow speed, medium speed and high speed diesel engines.1.1892年柴油机的问世归功于德国机械工程师、发明家鲁道夫狄塞尔。自此，由于与其他形式的推进装置比如蒸汽机或燃气轮机相比，柴油机在效率和设计上更具优势，在航运业发挥了很重要的作用。川出于技术原因，柴油机也叫压燃机。基于不同的参数柴油机有若干种分类方法。柴油机根据速度可分三类:低速、中速和高速柴油机。Slow Speed Diesel Engines低速柴油机2. Slow speed diesel engines are large, especially tall, and heavy and operate on the two-stroke cycle. They are the largest diesel engines ever built. Engine power up to 100,000 kW is available from a single engine. They are tall to allow for long strokes which improve engine efficiency. The large physical size of the engine and components leads to slow rotational speed with speeds up to 300 r/min considered to be slow. For equivalent power output, the two-stroke diesel engine is significantly lighter than the four-stroke one. This is most apparent for large power requirements where the two-stroke engine produces much more power for the same weight.2.低速柴油机体积大，高度特别高，而且重量大，以二冲程循环运转。这是迄今为止建造出的最大型的柴油机。单独一台发动机就能提供高达100 000 kW的功率。这类柴油机之所以高是为了容许长冲程，从而提高发动机的效率。大体积的柴油机和部件使得转速较慢，为300 r/min，这被视为低速。对于相同的输出功率，二冲程柴油机明显轻于四冲程柴油机。这一点对于满足大功率的需求是非常明显的，相同重量时二冲程柴油机能产生更大的功率。3. Large, slow speed, two-stroke marine diesel engines offer the advantages of burning poorer quality, cheaper fuel; providing large power from a single, less complicated machine comprising fewer individual cylinders and moving parts having a low rotational speed allowing them to be directly coupled to the propeller and removing the need for gearboxes; and being reversible and thus eliminating the need for reversing gear or controllable pitch propellers.3.大型低速二冲程船用柴油机有以下优点:燃烧质量较差、价格低廉的燃料;由单台不太复杂的发动机提供大功率，分段气缸和运动部件数量较少;具有低转速，能够直接连接螺旋桨，不需要变速箱;以及可倒转，从而无需换向装置或可调螺距螺旋桨。4. Merchant ships driven by slow speed diesel engine will usually have a single large main engine directly coupled to a single fixed pitch propeller. The thrust forces from the propeller will be transferred to the hull of the ship through a thrust bearing.4.由低速柴油机驱动的商船通常有一台大型主机直接连接到一个固定螺距螺旋桨。来自螺旋桨的推力通过推力轴承传送到船体。Medium Speed, Four-Stroke Diesel Engines中速四冲程柴油机5. Medium speed engines operate in speed ranges from 300 to 1,000 r/min. The majority of medium speed engines operate on the four-stroke cycle. They are most common as the propulsion engines in smaller ships, ro-ro and passenger ships. They are used widely as the electrical power generation engines in most merchant cargo ships5.中速柴油机的速度范围是300至1 000 r/min。大多数中速柴油机以四冲程循环运行。它们是小型船舶、滚装船和客船上常见的推进发动机。在大多数商用货船上，它们被广泛用作发电机。6. Four-stroke engines have more moving parts, are more complex and produce less power for equivalent weight compared to two-stroke slow speed engines. Medium speed engines do, however, offer several advantages.Fig. 1-1 A four-stroke diesel engine图1-1四冲程柴油机 The engines are compact-they are not long or high, this allows them to fit in engine rooms with low head space such as those in ro-ro ships. Medium speed engines use less oil than slow speed engines. Recent developments have produced medium speed engines capable of burning low quality heavy fuel oil. Engines of considerable power, to 25,000 kW and more, have been developed, allowing a large power system to be achieved with compact engines and engine room. This makes them suitable for passenger ship applications where the smaller the space provided for engines and machinery the more space is available for paying passengers.6.与同等重量的二冲程低速柴油机相比，四冲程柴油机(见图1-1)的运动部件更多，结构更复杂，产生的功率更低。但是，中速柴油机有以下几个方面的优势。发动机结构紧凑-其长度或高度不大，能够安装在净空高度较低的机舱内，如滚装船的机舱。中速柴油机比低速柴油机油耗低。最近研制生产出了能够燃烧低质量重油的中速柴油机。已开发了功率大于等于25 000 kW的大功率发动机，这使得结构紧凑的发动机和狭小的机舱都能实现大功率系统。这也使得这些发动机适用于客船，在客船上发动机和机器占的空间越小，可容纳乘客的空间就越大。7. Most medium-speed diesel engines are non-reversible meaning that a controllable pitch propeller is usually employed to cater for astern thrust.7.大多数中速柴油机是不可倒转的，这意味着，通常要使用可调螺距螺旋桨来实现倒车推进。High Speed Diesel Engines高速柴油机8. the most common diesel engine throughout the world is the high-speed engine. The majority of these engines operate on the four-stroke cycle but a significant proportion utilize the two-stroke cycle. These engines have running speeds over 1,000 r/min and are ideally suited to driving land-based vehicles such as buses and trucks. The application of high-speed diesel engines as propulsion engines at sea is limited to smaller vessels such as tugs, ferries and barges etc. They are regularly used for electrical power generation in support of a medium-speed propulsion engines and on large ships their use is limited to emergency power generation to small applications such as diesel driven emergency pumps and compressors8.全世界最常见的柴油机是高速柴油机。这类发动机大多数以四冲程循环运行，但也有相当大的比例利用二冲程循环。这些发动机运行速度在1 000 r/min以上，适于驱动陆地上的车辆，如公共汽车和卡车。应用高速柴油机在海上作为推进发动机只限于较小的船只，如拖船、渡船和驳船等。这类柴油机经常用于发电，以支持中速推进发动机，而在大型船舶上的应用仅限于小型装置的应急发电，如柴油驱动的应急泵和压缩机。Task 1 Reading Comprehension任务1阅读理解A. Topics for Discussion讨论话题1. What advantages do large, slow speed, two-stroke marine diesel engines offer?1.大型低速二冲程船用柴油机有哪些优点?Large，slow-speed，two-stroke marine diesel engines offer the advantages of burning poorerquality, cheaper fuel ;providing large power from a single，less complicated machine comprising fewer individual cylinders and moving parts; having a low rotational speed allowing them to be directly coupled to the propeller and removing the need for gear boxes ;and being reversible and thus eliminating the need for reversing gear or controllable pitch propellers.2. What advantages do medium speed engines offer?2.中速柴油机有哪些优点?Medium-speed engines offer the advantages of being compact-allowing them to fit in engine rooms with low head space ; using less oil than slow-speed engines ;being capable of burning lowquality heavy fuel oil; achieving a large power system with compact engines and engine room which makes them suitable for passenger ship applications where the smaller the space provided for engines and machinery the more space is available for paying passengers.3. What is the application of high-speed diesel engines?3.高速柴油机有哪些应用?High-speed diesel engines can be used to drive land-based vehicles such as buses and trucks. They can also be used as propulsion engines on smaller vessels such as tugs，ferries and barges etc.，and they are regularly used for electrical power generation in support of a medium-speed propulsion engines and on large ships their use is limited to emergency power generation to small applications such as diesel driven emergency pumps and compressors.D. Multiple Choices Questions 1-3 are based on paragraph 1. 根据课文第，段回答问题，1-31. Of all types of commercial internal combustion engines now built, which one usually gives the best performance, and hence it is quite commonly used in marine applications, especially in larger sizes? 所有目前建造的商用内燃机中，哪一种内燃机的性能最好，因此在船上的使用非常普遍，尤其在大型船舶上?答案:DA. Steam engine. 蒸汽机B. Gasoline engine. .汽油机。C. Gas turbine. 燃气轮机D. Diesel engine. 柴油机2. Which of the following statements is not true? 下列哪个表述是不正确的?答案.BA. Diesel engine was named after its inventor. 柴油机是以它的发明者的名字来命名的B. There is only one way to classify diesel engines based on various parameters.根据不同的参数，只有一种柴油机的分类方法C. Diesel engines are also called compression ignition engines.柴油机也被称作压燃机D. The diesel engine was invented in 1892.柴油机是在1892年发明的。3. Which form of propulsion engine used on ships is not mentioned in the text? 课文中没有提到的船用推进发动机是哪一种?答案.BA. Steam engine. 蒸汽机B. Nuclear power engine. 核动力发动机C. Gas turbine. 燃气轮机D. Diesel engine. 柴油机Questions 4-7 are based on paragraphs 2-4. 根据课文第2 -4段回答问题4 -74. Large, slow speed, two-stroke marine diesel engines offer the advantages of the following except .大型低速二冲程船用柴油机有下列优点，除了_。答案:DA. burning poorer quality, cheaper fuel燃烧质量较差价格低廉的燃料B. providing large power提供大功率C. being reversible可倒转D. using less oil than medium speed engines用油量少于中速柴油机5. Where will the thrust t forces from the propeller be transferred to through a thrust t bearing? 来自螺旋桨的推力通过推力轴承传送到哪里?答案.AA. The hull of the ship.船体B. The engine. 发动机C. The gearbox. 变速箱D. The crankshaft. 曲轴6. Why are slow speed diesel engines especially tall? 为什么低速柴油机特别高?答案CA. Because in this way the piston can be withdrawn downwards. 因为这样可以从下部拉出活塞。B. The engine can occupy larger space. 因为发动机可占据较大的空间。C. The engine may have long strokes which improve engine efficiency. 因为柴油机可以有长冲程以提高发动机的效率。D. More maintenance is provided. 因为要为柴油机提供较多的维护。7. Large, slow speed, two-stroke marine diesel engines are directly coupled to the propeller and do not require 大型低速二冲程船用柴油机直接连接螺旋桨，不需要_。答案:BA. pistons 活塞B. gearboxes变速箱C. crankshafts曲轴 D. thrust blocks推力块Questions 8-10 are based on paragraphs 5-7.根据课文第5 -7段回答问题8-108. If a diesel engine operates at about 700 r/min, then what is it known as? 如果柴油机在大约700 r/min的速度下运行，那么它可以被称作什么?答案;CA. A slow speed diesel engine. 低速柴油机B. A high speed diesel engine. 高速柴油机C. A medium speed diesel engine. .中速柴油机D. None of the above is true. 以上都不是9. Since most medium-speed diesel engines are non-reversible, what is usually used to cater for astern thrust? 由于大多数中速柴油机是不可倒转的，通常要使用什么来实现倒车推进?答案.BA. A reversing gear.换向机构B. A controllable pitch propeller. 可调螺距螺旋桨C. A fixed pitch propeller. 固定螺距螺旋桨D. A clutch. 离合器10. Medium speed engines have the following advantages except . 中速柴油机有如下优点，除了_答案 ; CA. medium speed engines use less oil than slow speed engines.中速柴油机比低速柴油机油耗低B. medium speed engines of later type are capable of burning low quality heavy fuel oil新型的中速柴油机可燃用低质量的重油C. the engines have long strokes which improve engine efficiency中速柴油机有长冲程以提高发动机效率D. the engines are compact. , thus providing more spaces for cargoes and passengers中速柴油机结构紧凑，这样为货物和乘客提供了更多的空间Questions 11-12 are based on paragraphs 811. Which of the following statements is not true according to the text? 根据课文，下列哪个表述是不正确的?答案.AA. The slow speed engine is the most common diesel engine throughout the world.低速柴油机是世界上最常见的柴油机。B. High speed engines may operate on the 4-stroke cycle or the 2-stroke one.高速柴油机可靠四冲程或二冲程运转C. High speed engines are suitable for driving trucks and buses.高速柴油机适合于驱动卡车和公共汽车。D. If the rotational speed of an engine is over 1, 200 r/min, then it is a high speed diesel engine. 转速高于1 200 r/min的柴油机是高速柴油机12. What is the application of high-speed diesel engines at sea? 高速柴油机在海上的应用有哪些?答案.DA. They are used for emergency power generation to small applications on large ships. 用于大型船舶上为小型装置应急发电。B. They are used for electrical power generation on board ships driven by medium- speed propulsion engines. 在中速柴油机驱动的船舶上用于发电C. They can be used on tugs, ferries and barges etc. as propulsion engines. 在拖船、渡船和驳船上用作推进发动机。D. All of the above. 以上全部。Task 2 Vocabulary and StructureA. Technical Terms A.专业术语Translate the following into Chinese. 将下列词组译成汉语。1. gas turbine燃气轮机2. compression ignition engine压燃机3. medium-speed diesel engine中速柴油机4. slow speed diesel engine低速柴油机5. two-stroke cycle二冲程循环6. reversing gear换向装置7. controllable pitch propeller可调螺距螺旋桨8. fixed pitch propeller固定螺距螺旋桨9. thrust bearing推力轴承10. ro-ro ship滚装船11. emergency pump应急泵B. Active WordsComplete the following sentences by filling in the blanks with the words in the table. Change the form of the words if necessary从框中选词完成句子，如有必要改变词的形式。.Comprise couple eliminate pump cater for transfer achieve1. The slow-speed diesel engine rotates at this low speed and the crankshaft is thus directly to the propeller shafting.coupled低速柴油机以这样低的速度运转，因此曲轴直接与螺旋桨轴相连。2. The United States fifty poses美国由50个州组成。3. The diesel engine operates with a fixed sequence of events, which may be either in four strokes or two.achieved柴油机按冲程固定顺序运转，可以是四冲程或二冲程4. The monowall construction the problems of refractory and expanded joints.eliminates整体式水冷壁结构消除了耐火材料和膨胀接头的问题。5. In cities, urban, social, cultural and educational policies often have to highly contrasting populations.cater for在城市里，城市、社会、文化以及教育等政策经常要满足极度不同的全体居民。6. A large surface area between the combustion chamber and the water enables heat to be to the water.transferred燃烧室和水之间大的表面积使得热量能够传递给水。7. Oil is drawn from the drain tank through strainers and to the coolers.pumped通过过滤器从泄放柜中吸收油再将其泵入冷却器。C. Handy PhrasesUnderstand the phrases by studying the sentences below and translate the phrases into Chinese. 通过学习下面的句子理解短语，并将短语译成汉语。1. attributed to: e. g. But the increased risk is small. Only five percent of the increased risk is attributed to maternal age.1.归因于例如:增加的危险很小，其中只有5%是由于母亲年龄引起的。2. due to: e. g. The scientists found that half of the 421 deaths were clearly due to carbon monoxide poisoning. 2.由于例如:科学家发现:421例死亡中有一半是由于一氧化碳中毒。3. based on: e. g. All Pm saying is that, based on recent evidence, we might need some new ones. 3.基于例如:我所说的是基于最近的证据，我们可能需要一些新的证据。4. lead to e. g. The loss of cooling water from an air compressor could lead to an overheated air discharge. 4.导致例如:空压机冷却水的损失可能导致排放的空气过热。5. play a role in: e. g. Now, no one is going to say that money doesnt play a role in politics. 5.在发挥作用例如:现在没有人会说金钱在政治上不起作用。Task 3 Translation Exercise任务3翻译练习A. Translate the following sentences into Chinese.将下列句子译成汉语。.1. The invention of the diesel engine in 1892 has been attributed to Rudolf Diesel