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Архитектура Аудит Военная наука Иностранные языки Медицина Металлургия Метрология Образование Политология Производство Психология Стандартизация Технологии |
Furnace, funnel, superheater, drum, tube, economizer, air heaterСтр 1 из 6Следующая ⇒
Give English equivalents. Котел; в той или иной форме; вырабатывать пар; дизельное судно, теплоход; различные судовые нужды; топка котла; давление; камера сгорания, топка, топочная камера; подавать; горение; происходить; в виде; процесс выработки пара; поступать в котел; превращаться в пар; циркулировать; паровой барабан; водяной барабан; проходить по трубам; снаружи; отработавшие, выхлопные газы; таким образом; тепловая энергия.
2.Ask questions according to the models.
1. The steam is produced in a steam boiler. 2. Temperature and pressure are stored in the steam. 3. Air is supplied to the boiler furnace. 4. The superheater is located within the boiler. 5. The hot gases are produced in the furnace.
1. A steam boiler produces steam from feed water. 2. Air enables combustion of the fuel. 3. Downcomer tubes join the steam and water drums. 4. Hot gases produce steam. 5. The feed water enters the boiler. Supply prepositions. 1. Steam is produced … very high temperatures and pressures. 2. Fuel is burnt … the furnace. 3. The feed water circulates … the steam drum … the water drum. 4. There is a large area … the combustion chamber and the water … the boiler. 5. The energy of combustion is transferred … the water. 6. Hot gases are exhausted … the funnel.
4. Complete the sentences. Choose the right word from the list. There are more words than necessary! Furnace, funnel, superheater, drum, tube, economizer, air heater 1. A part of the steam boiler that burns fuel is …. 2. A device of the boiler that heats the feed water is the …. 3. A device of the steam boiler that warms the steam is the …. 4. A device of the boiler that heats air for combustion is the …. 5. A device of the boiler that provides separation of steam and water is the ….
Answer the questions. 1. Where are large water-tube boilers installed? 2. What is a smaller boiler fitted for? 3. Do all boilers have a furnace? 4. In what form is the energy of combustion transferred to the water? 5. Where do steam and water separate? 6. Describe the steam generation process. 7. What are large-bore downcomer tubes used for? 8. What kind of steam is produced in the steam drum? 9. What happens to the steam in the superheater? 10. What are hot gases produced in the furnace used for? 11. What is the function of an air heater?
Translate into English. 1. Котлы устанавливаются на любом судне. 2. Если в энергетической установке принят паросиловой цикл, то на судне устанавливают один или несколько водотрубных котлов. 3. На дизельном судне один небольшой котел обеспечивает получение пара для различных судовых нужд. 4. При сгорании топлива выделяется энергия. 5. Котел должен иметь топку. 6. В барабане отделяются пар и вода. 7. Вода в процессе циркуляции нагревается. 8. Во влажном паре содержатся небольшие капельки влаги. 9. В пароперегревателе пар подогревается, и вода превращается в пар. 10. Горячие газы, образующиеся в топке, служат для нагрева питательной воды. 11. Воздухопогреватель подогревает воздух перед подачей в топку.
Write a dictation. Boilers can be found on every type of a ship. A boiler is used to produce steam feed water. The main parts of a boiler are: a furnace where fuel is burnt to release its energy; a drum where steam and water can separate; downcomer tubes which join the steam and water drums and are used to circulate feed water between them; an economizer which is used to heat the feed water and an air heater which warms the combustion air before it enters the furnace.
TEXT B MARINE BOILERS –A GENERAL OVERVIEW
Boilers are one of the most important items of equipment aboard ships. They are used for numerous purposes. Whether it is steam powered or has a diesel engine as the main form of propulsion, a ship without a boiler is really difficult to imagine. A boiler is a machine with the simplest arrangement of the internal parts. The main job of a boiler is to make high pressure steam. The feed water supplied to the boiler drum utilizes the heat of the energy released by burning the fuel. This energy of burning fuel is stored in the form of the steam with high temperature and pressure. The fuel is burnt in a combustion chamber inside the boiler. To attain high efficiency and complete combustion, air is supplied to this combustion chamber through a separate arrangement. The heat generated in this combustion chamber is transferred to the water from the boiler drum through a large area, which enables the highest rate of energy transfer. The process of steam generation starts when the feed water enters the steam drum through both internal tubes and the tubes that surround the furnace. The system of tubes that surrounds the furnace is known as water-wall or floor tubes. The feed water gets heated when passed through these tubes. In addition to this, there are large-bore downcomer tubes that pass outside of the furnace and are used to circulate water between the drums, to which the tubes are attached from outside of the furnace. The steam produced in the steam drum is known as wet or saturated steam. This steam cannot be used directly as it contains moisture. To make this steam usable, it is first dried and heated with the help of a superheater located within the boiler. When all moister is removed, the superheated steam can be supplied to other systems. To increase the efficiency of the boiler, the feed water that enters the boiler is pre-heated with the help of an economizer through which the feed water passes before entering the boiler. The exhaust gases of the boiler pass over an air heater, which heats up the combustion air entering the furnace. Thus, the energy of the exhaust gases does not go waste.
E X E R C I S E S
1. Learn the following word combinations and their translation. Make up your own sentences with them.
2. Complete the sentences. 1. The main job of a boiler is …. 2. The feed water utilizes …. 3. The fuel is burnt in …. 4. The heat produced in the furnace is …. 5. Water-wall or floor tubes are the system of …. 6. Large-bore downcomer tubes are used to …. 7. A superheater is located …. 8. Before entering the boiler the feed water passes through … 9. An air heater heats up ….
TEXT C A STEAM POWER PLANT
A steam power plant is used to propel a ship. It consists of a steam producing plant and a steam consuming unit. The steam power plant operates as follows: oil fuel is injected into the boiler furnace through burners which may vary in number in different types of boilers. The combustion of fuel generates heat radiated to the boiler tubes. This heat is absorbed by water and thus steam is formed. After that the heat is transmitted to the additional heating surfaces of the boiler. To convert the heat energy of the steam into useful work steam is admitted to the turbine. The steam enters nozzles where the energy of steam is converted into the kinetic energy. The steam expands and when it leaves the nozzles the kinetic energy is converted into mechanical energy at the turbine moving blades. In passing through the turbine the steam is reduced in temperature and pressure. The steam from the turbine passes to the condenser where it is changed into water. The water is pumped into the steam-water drum and the cycle is repeated. The whole arrangement which includes a water-tube boiler and a steam turbine is known as a steam power plant and is installed in turbo-driven ships.
Vocabulary
use, v использовать propel, v приводить в движение steam producing plant паропроизводящая установка steam consuming plant паропотребляющая установка burner, n форсунка vary, v изменяться surface, n поверхность moving blades движущиеся рабочие лопатки turbo-driven ship турбоход
e x e r c I s e s Answer the questions. 1. What is a steam power plant used for? 2. What units does s steam power plant consist of? 3. How is the steam in the steam power plant formed? 4. Where is the energy of steam converted into kinetic energy? 5. What energy is the kinetic energy converted into at the turbine moving blades? 6. Where is the steam from the turbine changed into water? 7. What ships is the steam power plant installed in? UNIT 2
TEXT A CLASSIFICATION OF MARINE BOILERS
Marine boilers are classified in different ways: 1. By the purpose they are designed for marine boilers are classified as main and auxiliary, or donkey boilers. The main steam boilers generate steam for the main engines, driving the propeller and for auxiliaries. The auxiliary boilers generate steam only for the auxiliaries, heating of oil and fuel tanks and other ship’s needs. 2. By their structure boilers are classified as the fire-tube boilers and the water-tube boilers. The fire-tube boiler, or a Scotch boiler, 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. The furnace, the combustion chamber and the tubes are all surrounded by water. Water-tube boilers have replaced fire-tube boilers. In the water-tube boiler feed water passes through the tubes surrounded by hot gases. It is used for high pressure, high temperature, and high capacity steam applications, e.g. providing steam for the main propulsion turbine or cargo pump turbines. 3. By the principle of water and steam water mixture motion the boilers are classified as natural and forced circulation boilers. The process of natural circulation occurs due to density difference of water and steam water mixture. If the working fluid is forced through the boiler by an external pump, the circulation is called the forced one. 4.By the way they are supplied with air boilers are classified as natural draft, forced draft and supercharged boilers. In natural draft boilers fuel is burnt under the pressure equal to the atmospheric pressure; forced draft is produced by placing a fan in the uptake, and exhausting through the furnaces; in supercharged boilers the pressure is much higher than the atmospheric pressure.
NOTES: depending on – в зависимости от e.g. = for example – например
Vocabulary
auxiliary (donkey) boiler вспомогательный котел propeller, n гребной винт; движитель shell, n кожух natural circulation boiler котел с естественной циркуляцией forced circulation boiler котел с принудительной циркуляцией density difference разность плотностей rate, n скорость; степень natural draft boiler котел на естественной тяге forced draft boiler котел с вентиляционным дутьем supercharged boiler котел с наддувом fan, n вентилятор uptake, n дымоход
E X E R C I S E S
1. Give English equivalents: По назначению; классифицировать; главный двигатель; обогрев топливных и масляных цистерн; судовые нужды; цилиндрической формы; внизу; средняя часть котла; заменять; движение воды и пароводяной смеси; происходить; по способу подачи воздуха; под давлением; равный; атмосферное давление. 2. Complete the sentences: 1. By the purpose they are designed for marine boilers can be classified as …. 2. By their structure boilers are classified as …. 3. In a Scotch boiler the furnace …. 4. The number of furnaces in the fire-tube boilers depends on …. 5. The water-tube boiler is used for …. 6. The process of natural circulation occurs due to …. 7. The circulation in the boiler is called the forced one because …. 8. By the way they are supplied with air boilers are classified as ….
3. Give English equivalents to the words in brackets: 1. (По назначению котлы делятся на) main and auxiliary boilers. 2. (По конструктивному исполнению) boilers may be classified as the fire-tube and the water-tube boilers. 3. (По принципу движения воды и пароводяной смеси) all boilers can be classified as natural and forced circulation boilers. 4. (По способу подачи воздуха на горение топлива, т.е. по давлению в топке) boilers are classified as natural draft, forced draft and supercharged boilers.
4. Self-assessment questions: 1. How are marine boilers classified by the purpose they are designed for? 2. Can you compare main and auxiliary boilers? 3. How are boilers classified by their structure? 4. Explain the difference between the fire-tube and the water-tube boilers. 5. What can you say about natural and forced circulation boilers? 6. What do you know about natural draft, forced draft and supercharged boilers? 5. Translate into English: 1. Главные котлы обеспечивают паром главный двигатель, приводящий в движение гребной винт. 2. Вспомогательный котел выдает пар только для вспомогательных механизмов. 3. По конструктивному исполнению котлы могут быть разделены на огнетрубные и водотрубные. 4. В огнетрубном котле топка со всех сторон окружена водой. 5. В водотрубных котлах питательная вода движется внутри труб, которые окружены горячими газами. 6. По принципу движения воды и пароводяной смеси все котлы можно разделить на агрегаты с естественной циркуляцией и с принудительным током воды. 7. Процесс естественной циркуляции происходит за счет разности плотностей воды и пароводяной смеси. 8. По способу подачи воздуха на горение топлива котлы можно разделить на обычные и с наддувом. TEXT B BOILER CLASSIFICATION
Boilers vary considerably in detail and design. In the following paragraphs, the classification of marine boilers according to intended service, location of fire and water spaces, type of circulation are considered. Intended service By this method of classification, marine boilers are divided into two classes, propulsion boilers and auxiliary boilers. Propulsion boilers are used to provide steam for ships' propulsion and for vital auxiliaries’ services. Auxiliary boilers are installed in diesel-driven ships and in many steam-driven ships. They supply the steam and hot water for galley, heating etc. and for other auxiliary requirements in port. Location of fire and water spaces One of the basic classifications of boilers is according to the location of the fire and water spaces. By this method of classification, boilers are divided into two classes, fire-tube boilers and water-tube boilers. In the fire-tube boilers, the gases of combustion flow through the tubes and heat the water that surrounds the tubes. In water-tube boilers, the water flows through the tubes and is heated by the gases of combustion that fill the furnace and heat the outside metal surfaces of the tubes. All propulsion boilers are of the water-tube type. Auxiliary boilers may be either fire-tube or water-tube boilers. Type of circulation Water-tube boilers are further classified according to the method of water circulation. Water-tube boilers may be classified as natural circulation boilers or forced circulation boilers. In natural circulation boilers, the circulation of water depends on the difference between the density of an ascending mixture of hot water and steam and a descending body of relatively cool and steam-free water. Forced circulation boilers are quite different in design from the boilers that use natural circulation. Forced circulation boilers depend upon pumps, rather than upon natural differences in density, for the circulation of water within the boiler.
E X E R C I S E S Translate into English. Двигатель внутреннего сгорания, теплообменник, таким образом, терять, пучок труб, отдавать тепло, оснащать, питательная вода, требовать, все еще, свыше, теплотворность, варьироваться, градусов Цельсия, тихоходный (низкооборотный) двухтактный двигатель, среднеоборотный четырехтактный двигатель, разрабатывать, тяжелые условия эксплуатации, теплоход. Translate into English. 1. Качество топлива определяется его элементарным составом, теплотой сгорания, вязкостью, удельным весом, температурой вспышки, температурой воспламенения и застывания, а также некоторыми другими характеристиками. 2. Топливо состоит из следующих химических элементов – углерода, водорода, кислорода, азота и частично серы. 3. Теплота сгорания топлива – это тепловая энергия, высвобождаемая во время сгорания. 4. Различают две теплоты сгорания: высшую и низшую. 5. Вязкость – это сопротивление при течении жидкости. 6. Вязкость определяют с помощью вискозиметров. 7. Тяжелое топливо обычно характеризуется высокой вязкостью. 8. Удельный вес - это соотношение веса определенных равных объемов топлива и воды. 9. При температуре воспламенения топливо начинает гореть. 10. Температура застывания – это самая низкая температура, при которой топливо можно перекачивать. 11. Следует также принимать во внимание следующие характеристики топлива: содержание золы, серы, влаги, содержание механических примесей, общую кислотность и некоторые другие характеристики.
TEXT B Fuel oils characteristics
Fuel oils have various characteristics which determine their performance and are quoted in specifications. The specific gravity is the weight of a given volume of fuel compared to the weight of the same volume of water expressed as a ratio, and measured at a fixed temperature. Viscosity is a resistance to flow. A highly viscous fuel will therefore require heating in order to make it flow. Measurement of viscosity is by Redwood, Saybolt seconds for a given volume of fuel. The ignition quality of fuel is measured by the time delay between injection and combustion, which should be short for good controlled burning. The flash point is the temperature at which the fuel is ignited with a small open flame. The pour point is slightly above the temperature at which the fuel just flows under its own weight. It is the lowest temperature at which the fuel can be easily handled. Sulphur content is of importance since it is considered a cause of engine wear. A maximum limitis usually included in specifications. The calorific value of a fuel is the heat energy released during combustion. Two values are used, the more common being the Higher Calorific Value, which is the heat energy resulting from combustion. The Lower Calorific Value is a measure of the heat energy available and does not include the heat energy contained in steam produced during combustion but passing away as exhaust. The measurement is obtained from a calorimeter test where a small fuel quantity is burnt under controlled conditions.
E X E R C I S E S E x e r c I s e s Supply prepositions. 1. Fuel oil characteristics should be taken … consideration when burning fuel. 2. A furnace fuel oil system consists … a fuel tank from which fuel is drawn … a strainer … a pump. 3. Fuel is ignited … the furnace. 4. Fuel is delivered … pressure … the burners. 5. Suction system is used … transferring fuel … remote tanks. 6. The fuel passes … the holes and then through the orifice … a conical spray … the furnace. Answer the questions. 1. What does a furnace provide? 2. What fuel oil characteristics should be taken into consideration when burning fuel? 3. Where is fuel drawn from? 4. Where does fuel mix with air? 5. What does the complete furnace fuel oil system consist of? 6. What is oil fuel filling system used for? 7. What system is used to deliver fuel under pressure to the burners? 8. What is the principle of burner operation?
UNIT 5
TEXT A FEED WATER
Feed water is the water supplied to a boiler to generate steam or hot water. It is delivered to the boiler by the feed pump. As the water is evaporated, the impurities in it remain in the boiler in the form of the salt deposits. Water containing impurities may lead to the following problems in boilers: scale, foaming, priming and corrosion. The chief salts forming scale are those of calcium and magnesium. Magnesium sulphate is a salt commonly found in boiler water and it forms a soft, sludgy mass, not very harmful, which can be removed by blowing down. Calcium sulphate produces a hard brittle scale. Alkalis or phosphate are sometimes put into marine boilers to prevent scale. Foaming may be the result of dirty water, certain types of organic matter, oils in solution, the presence of excess alkalinity. Oil is very injurious to a boiler: it adheres to the tube surfaces and causes overheating and rupture of tubes. Priming may be due to improper construction of boiler or extremely high ratings. The most common measure to prevent foaming and priming is to maintain the water at the lowest level. Avoiding high water levels, excessive boiler loads, and sudden load changes also helps. If foaming and priming occur, the blow off is opened several times, and fresh water is added. The main cause of boiler corrosion results from the dissolved gases, oxygen and carbon dioxide, found in feed water. They will react with the metals in the boiler system and lead to boiler corrosion. In order to protect the boiler from these contaminants, they should be controlled or removed, usually by use of a deaerator. Acids due to oils in solution may be neutralized by the addition of sodium carbonate. For efficient boiler operation a chemical analysis of the feed water must be run at least once a day.
Vocabulary
feed water питательная вода evaporate, v испаряться impurity, n примесь; загрязнение remain, v оставаться salt deposits отложения солей scale накипь foaming вспенивание priming вскипание soft sludge мягкий шлак; шлам brittle scale хрупкая, ломкая накипь harmful, adj вредный blowing down нижнее продувание alkali, n щелочь organic matter органическое вещество solution, n раствор excess alkalinity избыточная щелочность injurious, adj вредный adhere, v прилипать; приставать rupture, n разрыв rating, n мощность load, n нагрузка blow off верхнее продувание fresh water свежая; пресная вода dissolve, v растворять contaminant, n загрязняющее вещество; примесь deaerator, n деаэратор acid, n кислота sodium chloride хлорид натрия
E X E R C I S E S 1. Give English equivalents:
Питательная вода; подавать; питательный насос; содержать примеси; приводить к проблемам; коррозия; образовывать; кальций; магний; сульфат магния; мягкая масса; предотвращать образование накипи; наличие; вызывать перегрев; мера; избегать; чрезмерные нагрузки; углекислый газ; карбонат натрия, проводить химический анализ.
2.Change these sentences using the modal verbs may, can, must:
1. Foaming is due to the presence of dirty water in the boiler. 2. Oil in the feed water is very injurious to the boiler. 3. Priming is also due to a poorly designed steam drum. 4. Acids are neutralized by the addition of sodium carbonate. 5. A little of the chemicals is added at a time. 3. Change these sentences into the passive:
1. The addition of alkalis prevents scale formation. 2. The presence of oils in solution causes foaming. 3. Some of the salts produce a soft sludge. 4. The chlorides of sodium and magnesium and the sulphate of iron cause corrosion. 5. We may neutralize acids by the addition of sodium carbonate.
4. Supply prepositions: 1. Feed water is the water supplied … a boiler … the feed pump. 2. The impurities … the boiler remain … the form of the salt deposits. 3. Alkalis or phosphate are put … marine boilers to prevent scale. 4. Oil is very injurious … a boiler as it adheres … the tube surfaces. 5. Priming may be due … improper construction of boiler. 6. To prevent priming it is necessary to maintain the water … the lowest level. 7. Corrosion results … the dissolved gases found … feed water. 8. Acids may be neutralized … the addition of sodium carbonate. 5. Answer the questions: 1. What is feed water? 2. By what device is the feed water supplied to the boiler? 3. What substances remain in the boiler as the water is evaporated? 4. What problems may water containing impurities lead to? 5. How can a soft sludge be removed? 6. What salt produces a hard scale? 7. What may foaming be the result of? 8. What may priming be due to? 9. What gases cause corrosion? 10. How often must a chemical analysis of the feed water be run? 6. Translate into English: 1. Питательная вода подается в котел насосом. 2. Примеси воды остаются в котле в виде отложений. 3. Мягкий шлак может быть удален из котла продуванием. 4. Некоторые соли образуют твердую накипь. 5. Для предотвращения накипи в котле используются щелочи и фосфаты. 6. Содержание в воде органических веществ может привести к вспениванию. 7. В случае вскипания применяется продувание и добавляется свежая вода. 8. Растворенные в питательной воде кислород и углекислота вызывают коррозию стенок котлов. 9. Химический анализ питательной воды должен производиться на судне не реже одного раза в день.
TEXT B Purity of boiler feed water
Modern boilers require very pure feed water. The water required for boiler feed purposes, i.e. for steam generation should be of very high quality and thus requires a lot of treatment. Untreated water, containing impurities may lead to the following problems in boilers. Most pure water will contain some dissolved salts. These salts then adhere to the heating surfaces as a scale and reduce heat transfer, which can result in local overheating and failure of the tubes. Other salts remain in solution and may produce acids which will attack the metal of the boiler. An excess of alkaline salts in a boiler will cause cracking of the metal which may lead to serious failure. The presence of dissolved oxygen and carbon dioxide in boiler feed water can cause considerable corrosion of the boiler and feed systems. When boiler water is contaminated by suspended matter, an excess of salts or oil, foaming may occur. This is foam which collects on the water surface in the boiler drum. Foaming leads to priming which is the carry-over of water with the steam leaving the boiler drum. Any water present in the steam entering a turbine will do considerable damage. Various amounts of different metal salts can be found in water. These include the chlorides, sulphates and carbonates of calcium, magnesium. These dissolved salts in water make up the 'hardness' of the water. Calcium and magnesium salts are the main causes of hardness.
E X E R C I S E S 1. Find the corresponding Russian translation. Memorize the phrases.
Complete the sentences. 1. Boiler feed water is required for …. 2. Untreated water leads to …. 3. Dissolved salts may lead to such problems as …. 4. An excess of alkaline salts in a boiler causes …. 5. Foaming occurs when …. 6. Such metal salts as … make up the 'hardness' of the water.
TEXT C CONTAMINATION OF FEED water
The quality of boiler water plays an important role in boiler operation. Contamination of boiler water leads to several types of problems, including the main ones – corrosion and scale formation. Inside the boiler system, the boiler feed water passes through a series of tubes and equipment. The feed water is always chemically treated to reduce the effects of harmful minerals and gases. The main problem starts when a lot of this boiler feed water is lost through leakages and processes such as boiler blow down, soot blowing etc., and make-up water is added to compensate this loss. This make-up water brings in a lot of the impurities into the boiler system. How is the make-up feed water contaminated? Boiler feed water is mainly taken from the fresh water generator. The sea water contains a large amount of salts and other dissolved minerals and gases. Many of them are harmful and eventually lead to boiler problems. Saltdeposits act as insulators and lower the heat transfer rate. The insulating effect of deposits also causes the boiler metal temperature to rise and lead to tube-failure by overheating. Large amounts of such deposits throughout the boiler can reduce the heat transfer and decrease the overall boiler efficiency.
Vocabulary contamination, v загрязнение treat feed water подготавливать питательную воду harmful, adj вредный, опасный leakage, n утечка, течь boiler blow down продувание котла sootblowing сажеобдувание fresh water generator опреснитель; опреснительная установка dissolve, v растворять salt deposits отложение солей insulator, n изолятор heat transfer rate скорость теплоотдачи overall, adj общий
E X E R C I S E S 1. Change these sentences using the modal verbs may, can, must:
1. Foaming is due to the presence of dirty water in the boiler. 2. Oil in the feed water is very injurious to the boiler. 3. Priming is also due to a poorly designed steam drum. 4. Acids are neutralized by the addition of sodium carbonate. 5. A little of the chemicals is added at a time. 2. Change these sentences into the passive:
1. The addition of alkalis prevents scale formation. 2. The presence of oils in solution causes foaming. 3. Some of the salts produce a soft sludge. 4. The chlorides of sodium and magnesium and the sulphate of iron cause corrosion. 5. We may neutralize acids by the addition of sodium carbonate.
UNIT 6
TEXT A BOILER PARTS. THE FURNACE
A furnace provides steady burning of fuel. The furnaces of marine water-tube boilers are lined with refractory firebrick backed up by the insulating bricks. This brickwork acts as furnace insulation and also, by maintaining a high furnace wall temperature, assists combustion. Water walls are used in water-tube boilers to contain the heat of the furnace and reduce the amount of refractory material required. Water walls consist of a number of tubes and extend along the sides of the furnace setting. To provide the efficient combustion process of burning oil fuel, a certain set of conditions is necessary: maintenance of high furnace temperature, provision of continuous oil fuel and air supply and removing products of combustion. The oil is first heated in steam or electric fuel oil heaters. This reduces its viscosity and makes it easier to pump, filter, and finally to atomize. The heated oil passes through the burners where it is atomized; this process breaks it up into a fine spray of droplets presenting a very large surface area of oil to the combustion processes. Different types of burners have been designed for burning liquid fuel. Mechanical oil burners and steam-assisted ones are employed to obtain efficient atomization. Mechanical atomizing oil burners may be classified according to their method of atomization as centrifugal atomizers and rotary cup atomizers. Steam-assisted oil burners are widely spread in marine practice. Their advantages are high quality atomization and a wide range of fuel oil feed control.
Vocabulary steady, adj устойчивый firebrick, n огнеупорный кирпич brickwork, n кирпичная кладка insulation, n изоляция assist, v помогать; способствовать water wall экран из водогрейных трубок amount, n количество setting, n кладка; обмуровка set of conditions комплекс условий maintenance, n поддержание atomize, v распылять; тонко измельчать to break up разбивать(ся) droplet, n капля surface, n поверхность mechanical oil burner механическая форсунка steam-assisted oil burner паромеханическая форсунка centrifugal atomizer центробежный распылитель rotary cup atomizer форсунка с вращающимся распылителем range, n диапазон oil feed подача топлива
E X E R C I S E S
Give English equivalents. Обеспечивать; горение топлива; облицовывать (футеровать); выступать в качестве; горение; тянуться; поддерживать; высокая топочная температура; непрерывная подача; продукты сгорания; топливоподогреватель; уменьшать вязкость; проходить; мелкораспыленная струя; по методу распыления; преимущество; регулирование.
Supply prepositions. 1. Water-tube boilers are lined … refractory firebrick. 2. The brickwork acts … furnace insulation. 3. Water walls consist … a number of tubes and extend … the sides of the furnace setting. 4. The oil is first heated … steam or electric fuel oil heaters. 5. The heated oil passes … the burners where it is atomized. 6. Mechanical atomizing oil burners may be classified … … their method of atomization. 7. Steam-assisted oil burners are widely spread … marine practice. 3.Self-assessment questions. 1. What does a furnace provide? 2. What are furnace walls lined with? 3. What is the function of water walls? 4. What set of conditions is necessary to provide the efficient burning of oil fuel? 5. Why should the oil be heated? 6. What types of burners do you know? 7. What are the advantages of steam-assisted oil burners? UNIT VI. THE SUPERHEATER
The efficiency of the steam power plant is influenced by the steam conditions, i.e. pressure and temperature. That is why the superheater is an essential part of the modern marine boiler. Steam is superheated by being heated above the temperature of saturation. Superheaters may be divided into several types: - the convection type installed in one of the gas passages of the boiler; - the radiant type installed in the boiler furnace; - the multi-loop type placed remote from the furnace in the lower part of the uptake. The convection type superheater usually consists of two headers into which seamless steel tubes are rolled. The tubes are connected to the steam inlet header and to the superheater outlet header. Steam from the boiler circulates through these tubes. Superheater tubes range from 1 to 2 in. in diameter; the temperature rarely exceeds 550°C, as the tensile strength of most metals decreases rapidly after passing 350°C. With increased evaporation rates and higher superheat temperatures, many modern boilers use multi-loop type superheaters. These superheaters consist of a number of multi-loop tube elements. The steam enters all the tubes together, but makes several passes across the gas stream through each element. The boiler drums are designed for a certain maximum operating pressure. When the steam pressure gets above the safe minimum, the safety valve should open and steam discharged. So all superheaters must have one or more safety valves.
Vocabulary superheater, n пароперегреватель efficiency, n производительность; КПД steam conditions параметры пара saturation, n насыщение convection type superheater конвективный тип пароперегревателя radiant type superheater радиационный тип пароперегревателя multi-loop type superheater змеевиковый тип пароперегревателя remote отдельно uptake, n дымоход seamless, adj бесшовный roll, v вальцевать; прокатывать inlet header входной коллектор outlet header выходной (выпускной) коллектор range, v колебаться в пределах inch (in.), n дюйм exceed, v превышать tensile strength предел прочности decrease, v уменьшать evaporation rate скорость или интенсивность испарения; паропроизводительность gas stream поток газа
E X E R C I S E S 1. Give English equivalents: Паросиловая установка, влиять, давление, выше температуры, устанавливать, размещать, соединять с, редко, быстро, использовать, поступать в, рабочее давление, слегка перегретый пар, вспомогательные механизмы, установка/агрегат, при необходимости, потребность в паре, существовать, в случае продувки котла.
2. Complete the statements. Choose the proper word from the list: E X E R C I S E S
1. Give English equivalents: Подогреватель питательной воды, топочные газы, греющая среда, поступать в котел, отработавшие газы, проходить через, состоять из, коллектор, с помощью, в одном направлении, в противоположном направлении, приводить к, теплопередача, при необходимости, поверхность теплообмена.
2. Insert prepositions and conjunctions: 1. … the economizer flue gases are used … a heating medium. 2. The economizer is interposed … the boiler and stack. 3. The economizer is placed … the uptakes. 4. Feed water passes … the economizer … its way … the steam drum. 5. The tubes are rolled … the headers. 6. Return bends are usually connected … flange joints … straight run … tubing. 7. The counterflow results … a greater heat transfer. 8. Drain valves enable the economizer to be emptied … water when required.
3. Answer the questions: 1. What is an economizer? 2. What is used as a heating medium in the economizer? 3. What is the economizer used for? 4. Where is the economizer interposed? 5. Does the economizer increase boiler efficiency? 6. What does a typical economizer consist of? 7. What is used when headers are not employed? 8. What is the diameter of the economizer steel tubes? 9. What can occur if the fed temperature falls below 115°C? 10. How are economizers classified according to their gas and water flow? 11. What are parallel and counterflow economizers? 12. Which flow is considered to be the more effective in economizers? 13. What must air vents be provided for? 14. What arrangements must be fitted to keep the heat exchange surfaces free from soot?
4. Translate the phrases containing comparatives and superlatives: A great heat transfer – a greater heat transfer – the greatest heat transfer; effective – more effective – the most effective; a large heating surface – a larger heating surface – the largest heating surface.
5. Translate into English: 1. Экономайзер – это подогреватель питательной воды. 2. Экономайзер увеличивает КПД котла. 3. Трубки экономайзера омываются с внешней стороны горячими топочными газами. 4. Возвратные колена подсоединены к прямому трубопроводу с помощью фланцев. 5. Противоток более эффективен, так как приводит к большей отдаче тепла. 6. На экономайзере устанавливают предохранительные клапаны, спускные дренажные клапаны и сажеобдувочные устройства.
UNIT 7 TEXT A A Procedure for Starting a Boiler
A boiler is one of those machineries that gets the ship going. It is dangerous equipment which generates steam at extremely high pressure, and it is for this reason that proper care should be taken while operating it. Starting a Boiler The following steps may not apply to all types of boilers and each boiler requires some additional steps to be followed as for its system design. However, the basic steps remain the same: 1. Ensure that the vent valve on the boiler is open and check there is no pressure in the boiler. 2. Check that the steam stop valve is closed. 3. Check that all the valves for fuel are open, and let the fuel circulate through the system until it comes to the temperature required by the manufacturer recommendation. 4. Check and open the feed water valves to the boiler and fill the water inside the boiler drum to just above the low water level. This is done because it is not possible to start the boiler below the low water level due to safety feature which prevent boiler from starting. Also, the level is not filled much because if filled too much, the water inside the boiler might expand and over pressurize the boiler. 5. Start the boiler in automatic mode. The burner fan will start the purging cycle which will remove any gases present in the furnace by forcing it out through the funnel. 6. After the pre-set purge time the pilot burner will ignite. 7. The main burner which is supplied by heavy oil catches fire with the help of pilot burner. 8. Check the combustion chamber from the sight glass to ensure the burner has lit and the flame is satisfactory. 9. Keep a close eye on the water level as the pressure increases and open the feed water when the level of water inside the gauge glass is stable. 10. Close the vent valve after the steam starts coming outside. 11. Open the steam stop valve. 12. Once the working steam pressure is reached, blow down the gauge glass and check for the alarms.
E x e r c I s e s
E X E R C I S E S Translate into English. 1. Остановка котла может быть запланированной или вынужденной из-за поломки оборудования. 2. В случае упуска воды котел должен быть немедленно остановлен. 3. Течи в трубах котла ликвидируются с помощью пробок или сваркой. 4. Для уменьшения давления пара в котле следует открыть предохранительный клапан. 5. Очистите трубы и коллекторы от накипи. 6. Водомерную колонку следует снять и очистить. 7. Проверьте и замените сальники клапанов.
TEXT C IRREGULARITIES IN OPERATION, CAUSES AND REMEDIES
Vocabulary
remedy, nспособ устранения неисправности faulty, adj неисправный penetration, n проникновение cut-off valve запорный (секущий) клапан valve disc тарелка клапана shut down, v выключить; остановить light (lit; lit), v зажигать sediment, n осадок; отложение E X E R C I S E S 1. Replace the imperative sentences (REMEDY) by the following structures:
· it is possible – возможно · it is important – важно · it is necessary – необходимо · it is desirable – желательно · it is preferable – предпочтительно · it is imperative – обязательно, необходимо · it is evident/obvious – очевидно · it is advisable – желательно · it is sufficient – достаточно
2. Translate these phrases into Russian: it is usual – it is unusual; it is common – it is uncommon; it is equal –it is unequal; it is possible – it is impossible; it is important – it is unimportant; it is necessary – it is unnecessary; it is desirable- it is undesirable; it is convenient – it is inconvenient; it is effective – it is ineffective; it is sufficient – it is insufficient; it is essential – it is inessential; it is practical – it is impractical; it is practicable – it is impracticable.
Give English equivalents. Котел; в той или иной форме; вырабатывать пар; дизельное судно, теплоход; различные судовые нужды; топка котла; давление; камера сгорания, топка, топочная камера; подавать; горение; происходить; в виде; процесс выработки пара; поступать в котел; превращаться в пар; циркулировать; паровой барабан; водяной барабан; проходить по трубам; снаружи; отработавшие, выхлопные газы; таким образом; тепловая энергия.
2.Ask questions according to the models.
1. The steam is produced in a steam boiler. 2. Temperature and pressure are stored in the steam. 3. Air is supplied to the boiler furnace. 4. The superheater is located within the boiler. 5. The hot gases are produced in the furnace.
1. A steam boiler produces steam from feed water. 2. Air enables combustion of the fuel. 3. Downcomer tubes join the steam and water drums. 4. Hot gases produce steam. 5. The feed water enters the boiler. Supply prepositions. 1. Steam is produced … very high temperatures and pressures. 2. Fuel is burnt … the furnace. 3. The feed water circulates … the steam drum … the water drum. 4. There is a large area … the combustion chamber and the water … the boiler. 5. The energy of combustion is transferred … the water. 6. Hot gases are exhausted … the funnel.
4. Complete the sentences. Choose the right word from the list. There are more words than necessary! Furnace, funnel, superheater, drum, tube, economizer, air heater 1. A part of the steam boiler that burns fuel is …. 2. A device of the boiler that heats the feed water is the …. 3. A device of the steam boiler that warms the steam is the …. 4. A device of the boiler that heats air for combustion is the …. 5. A device of the boiler that provides separation of steam and water is the ….
Answer the questions. 1. Where are large water-tube boilers installed? 2. What is a smaller boiler fitted for? 3. Do all boilers have a furnace? 4. In what form is the energy of combustion transferred to the water? 5. Where do steam and water separate? 6. Describe the steam generation process. 7. What are large-bore downcomer tubes used for? 8. What kind of steam is produced in the steam drum? 9. What happens to the steam in the superheater? 10. What are hot gases produced in the furnace used for? 11. What is the function of an air heater?
Translate into English. 1. Котлы устанавливаются на любом судне. 2. Если в энергетической установке принят паросиловой цикл, то на судне устанавливают один или несколько водотрубных котлов. 3. На дизельном судне один небольшой котел обеспечивает получение пара для различных судовых нужд. 4. При сгорании топлива выделяется энергия. 5. Котел должен иметь топку. 6. В барабане отделяются пар и вода. 7. Вода в процессе циркуляции нагревается. 8. Во влажном паре содержатся небольшие капельки влаги. 9. В пароперегревателе пар подогревается, и вода превращается в пар. 10. Горячие газы, образующиеся в топке, служат для нагрева питательной воды. 11. Воздухопогреватель подогревает воздух перед подачей в топку.
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