- •Vocabulary
- •Give English equivalents.
- •2. Ask questions according to the models.
- •3. Supply prepositions.
- •4. Complete the sentences. Choose the right word from the list. There are more words than necessary!
- •5. Answer the questions.
- •6. TranslateintoEnglish.
- •7. Write a dictation.
- •Vocabulary
- •1. Choose the proper verb form.
- •2. Answer the questions.
- •Vocabulary
- •1. GiveEnglishequivalents:
- •2. Complete the sentences:
- •3. Give English equivalents to the words in brackets:
- •4.Self-assessment questions:
- •5. Translate into English:
- •1. Translate the word combinations into Russian and use them in your own sentences.
- •2. Choose the proper verb form, active or passive.
- •Vocabulary
- •1. TranslateintoEnglish.
- •2. Supply the proper preposition.
- •Vocabulary
- •Give English equivalents:
- •Answer the questions according to the models:
- •Match the type of the boiler with its principle of classification:
- •Self-assessment questions:
- •5.Translate into English:
- •1. Find the corresponding English translation in the text and memorize the words.
- •2. Put questions to the sentences.
- •Vocabulary
- •1. Give answers to the questions:
- •2. Translate into English:
- •Vocabulary
- •1.Give English equivalents:
- •2. Ask questions according to the model:
- •3. Complete the sentences:
- •4. Answer the questions:
- •5. Translate into English.
- •2. Translate the word combinations and use them in your own sentences.
- •Vocabulary
- •1. Supply prepositions.
- •2. Answer the questions.
- •Vocabulary
- •1. GiveEnglishequivalents:
- •2.Change these sentences using the modal verbs may, can, must:
- •3. Change these sentences into the passive:
- •4. Supply prepositions:
- •5. Answer the questions:
- •6. TranslateintoEnglish:
- •2. Complete the sentences.
- •Vocabulary
- •1. Change these sentences using the modal verbs may, can, must:
- •2. Change these sentences into the passive:
- •Vocabulary
- •1. Give English equivalents.
- •2. Supply prepositions.
- •3.Self-assessment questions.
- •4. Translate the words into Russian.
- •5. Choose the proper verb and put it into the correct form. There are more verbs than necessary.
- •6. Translate into English:
- •Unit VI. The superheater
- •Vocabulary
- •1. GiveEnglishequivalents:
- •Saturation, inlet, tubes, outlet, drums, safety valve, uptake, headers
- •3. Answer the questions:
- •Vocabulary
- •1. GiveEnglishequivalents:
- •2. Insert prepositions and conjunctions:
- •3. Answer the questions:
- •4. Translate the phrases containing comparatives and superlatives:
- •5. Translate into English:
- •1. Find English equivalents in the text.
- •2. Write down all the imperative phrases typical for this instruction.
- •3. Put questions to the sentences.
- •Vocabulary
- •1. Combine these pairs of sentences by using “if”.
- •2. TranslateintoEnglish.
- •Irregularities in operation, causes and remedies
- •Vocabulary
- •1. Replace the imperative sentences (remedy) by the following structures:
- •2. Translate these phrases into Russian:
2. Supply the proper preposition.
1. Exhaust gas heat exchanger is mounted … the main engine uptake.
2. The exhaust gases are sent to the funnel … lower temperatures.
3. The exhaust gas boiler is equipped … an economizer and a superheater.
4. Thermal energy contained in the exhaust gases of diesel engines is superior … 30% of the total heating value … the fuel.
5. The temperatures of the exhaust gases vary … 270°C … 320°C for slow two- stroke engines.
6. This residual energy is recovered … using exhaust gas boilers.
UNIT 3
TEXT A
WATER-TUBE BOILER DESIGN
One of the most commonly used types of marine boilers is a water-tube boiler. In the water-tube boiler the gases pass around a number of small diameter tubes through which steam-water mixture circulates.
In a modern water-tube boiler burners are located in front of the furnace.
Thefurnaceisthe placewhereairandfuelaremixedforthecombustionthatheatsthewater in thedrums, tubesandheaders. Itislinedonthefloorandwalls withrefractorymaterialwhichpreventstheheatlossduetoradiation.
Thefurnaceissurroundedonallsidesbytubes. Thesetubesareconnectedeithertoupperandlowerheadersor a lowerheaderandthesteamdrum.
Betweenthesteamdrumandthesmallerwaterdrumbelow, largenumbersof smaller-diameter generatingtubesarefitted.Theyprovidethemainheattransfersurfacesforsteamgeneration.Large-borepipesordowncomersarefittedbetweenthesteamandwaterdrumtoensuregoodnaturalcirculationofthewater.
Superheatersareessentially a bankoftubesusedtoheatthesteamabovethesaturationtemperature.Superheater tubing is used to further cool the gases; as gases are cooled, the steam is superheated.
Economizersareheatexchangerswhicharefitted in a boilertoincreasetheefficiencyoftheboiler. Thisisdonebyextractingtheheatfromthegasesandusingittoheatthefeedwaterenteringtheboiler.
Air heaters are used to heat combustion air and to recover more of the heat energy from the exhaust gases before they are sent to the stack.
There are two types of water-tube boilers - main boilers and auxiliary boilers.
The circulation in water-tube boilers is either natural or forced.
According to the pressure they are classed as low, intermediate and high pressure boilers. The boilers generating steam under the pressure up to 15 atm. are called low pressure boilers, up to 28 atm. intermediate pressure boilers, and those generating steam under the pressure higher than 28 atm. may be called high pressure marine water-tube boilers.
As to more detailed classification of water-tube boilers they may be classed:
а) according to the number of drums as single-drum, two-drum and three-drum boilers;
b) according to the tube inclination as horizontal – those having tube inclination up to 30, and vertical – with tube inclination of 45-90;
c) according to the superheater location as horizontal and vertical;
d) according to the arrangement of gas flow as single-flow and double flow.
Vocabulary
mixture, nсмесь
front of the boiler фронт (передняячасть) котла
header, n коллектор
line (with), v облицовывать; футеровать; выкладывать
floor, n под (топки)
refractory, adj огнеупорный; жаростойкий
duetoradiation из-за излучения
generatingtubes водогрейные (испарительные) трубы котла
provide, v обеспечивать
heattransfersurface теплопередающая поверхность
steamgeneration парообразование
large-borepipes трубы с большим (внутренним) диаметром
superheater, n пароперегреватель
bankoftubes пучок труб
saturation temperature температуранасыщения
economizer, n экономайзер
heatexchanger теплообменник
efficiency, n производительность; КПД
extract, v извлекать
recover, v утилизировать
stack, n дымовая труба
intermediatepressure среднее (промежуточное) давление
single-drumоднобарабанный
inclination, n наклон
arrangement of gas flow способтечениягаза
single-flowоднопроточный (одноходовой)
E X E R C I S E S