#140_Разговорные_темы(I-II)

Figure 1. Shell and tube heat exchanger.

1.shell (cylindrical ),

2.header, water box,

3.cooling fluid,

4.cover seal,

5.separation plate (for 2-pass arrangement),

6.header cover,

7.tube plate,

8.gaskets (between tube plate and shell, tube plate and header),

9.hot fluid, (to be cooled),

10.baffle (to direct the flow of hot fluid back and forth across the tube bundle),

11.tube bundle, tube nest, tube stack,

12.shell branches,

13.elastomer seals (on both sides of a safety leakage ring).

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Figure 2. Plate type heat exchanger.

1.end plate, head plate, clamping plate,

2.tie-bolt

3.fluid branches, fluid connections (in line with ports in the plates),

4.stack of exchange plates (with dimples pressed in the plate surface),

5.peripheric [Ãq'ÏÁÇqÏÁÐ] elastomer seal (периферическое tie-bolt,

уплотнение из эластомера),

6.ports and seals

Vocabulary:

alternate – ['² lt´neIt] v.– поочередно сменяться baffle ['bxfql] n.– перегородка

due to [ÌÓ³ 't³ ] prep.– благодаря/вследствие engine ['enGIn] n. – двигательная установка extremely [ÁÐ'sËÏ°ÅÎI] adv. – крайне/чрезвычайно fluid ['Çγ ÁÌ] n.– текучая среда

heat exchanger [hJt Iks'CeIGq] – теплообменник; heat transfer area [h°t "trxnsfq 'eqrIq] – поверхность теплообмена/теплопередачи

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heat transfer efficiency [h°t"trxnsfq Á'ÇÁS¶ÍÉÁ] – коэффициент

теплопередачи

leak tight seal ["l°k ËÕÁË 's°l] – непроницаемая перемычка/прокладка low pressure application [lqu "pÏÂS¶ "xplI'keISn] – установка, работающая

под низким давлением

plate type heat exchanger ["pleIt taIp "h°t Iks'CeIGq] – пластинчатый

теплообменник

press-fitted tube [pres"fItId 'ËjV:Ä] – запрессованная труба

shell and tube heat exchanger [Sel qnd "tj³ b h°t Iks'CeIGq] – кожухотрубный

теплообменник

shell side fluid ['Sel said "fl³ Id] – межтрубная текучая среда tube side fluid ['tj³ b said "fl³ Id] – внутритрубная текучая среда

Answer the following questions:

1.What two main types of constructions are mentioned in the text?

2.What does shell and tube heat exchanger consist of?

3.What does plate type heat exchanger consist of?

4.What is the advantage of plate type heat exchanger?

5.Why is plate type heat exchanger capable of transferring much more heat?

6.Why is plate type heat exchanger used in small, low pressure applications only?

7.What type of heat exchanger is becoming more common?

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ТЭ, ЭЭ, ТСБ, ПВ (III семестр)

BOILERS

Boilers can be classified in various ways, depending on firing method used, fuel fired, field of application, type of water circulation employed, and pressure of steam. Depending on their construction boilers can be divided into: fire tube boilers (Figure 3.), water tube boilers (Figure 4.).

Fire tube boilers have been used in various early forms to produce steam for industrial purposes. The fire tube boiler is a special form of the shell tube type boiler. A shell type boiler is a closed, usually cylindrical vessel that contains water. Hot gases pass through the tubes during the heat transfer process. The shell boiler evolved into modern forms such as the electric boiler, in which heat is supplied by electrodes embedded in the water.

Figure 3. Fire tube boilers.

The difference between fire tubes and water tubes is simple; water flows through water tubes instead of fire. The advantage of the water tube boiler is that it can work in high steam pressure and capacities. With higher steam pressure and capacities, fire tube boilers would need large diameter of shell. With such large diameter, the shell would have to operate under such extreme pressure and thermal stresses that their thickness would have been too large.

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Figure 4. Water tube boilers.

The basic purpose of any boiler is to convert the chemical energy in fuel into thermal energy that can be used to generate steam or hot water. Inside the combustion chamber, two fundamental processes must occur to achieve this objective. First, the fuel must be mixed with sufficient oxygen to allow sustained combustion. The heated gases produced by the combustion process must then transfer the thermal energy to a fluid such as water or steam. The design of the boilers depends on factors such as the type of fuel and the method selected to transfer thermal energy. Boilers are manufactured in a wide range of sizes to burn coal, oil, natural gas, biomass as well as other fuels and fuel combinations.

Vocabulary:

biomass ['ÄÕIqÅ·É] – биомасса;

chemical energy ["ÐÂÅIÐqÎ 'enqGI] – химическая энергия;

combustion chamber [kqÅ"ĵÉÀqÍ 'CeImbq] chamber – камера сгорания; combustion process [kqÅ"ĵÉÀqÍ 'prquses] – процесс горения; cylindrical vessel [ÉI"ÎIÍdÏIÐqÎ 'vesl] – цилиндрический сосуд; diameter of shell [dÕI"·ÅIËq qv 'Sel] – диаметр кожуха

electric boiler [I"lektrIk 'bOIlq] – электрический бойлер field of application [f°ld qv "xplI'keISn] – область применения

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fire tube boiler ["faIq tj³ b 'bOIlq] – дымогарный котел firing method ["ÇÕI¶ÏIN'meTqd] – способ/метод горения

fuel combination ["Çj³ ¶Î "kPmbI'neISn] – горючая/топливная смесь fuel fired ['Çj³ ¶Î 'faIqd] – работающий на минеральном топливе fundamental process ["ЗµНd¶'ЕВНЛО 'prquses] – основной процесс high steam pressure [haI stJm 'ÃÏ¿q] – высокое давление пара; oxygen ['PÐÉI»qÍ] n.– кислород;

sustained combustion [ÉqÉ'ËÂIÍÌ kqm'bAsCqn] – устойчивое /равномерное

горение

thermal energy ["¾WÅqÎ 'enqGI] – термическая энергия thermal stress ["¾WÅqÎ 'stres] – термическое напряжение water circulation ["w² tq "ÉWÐÓq'ÎÂi¿Í] – циркуляция воды; water tube boiler ['wLtq tjHb "bPIlq] – водотрубный котел

Answer the following questions:

1.How can boilers be classified?

2.How can boilers be divided depending on their construction?

3.What have fire tube boilers been used for?

4.What is the difference between fire tubes and water tubes?

5.What is the advantage of the water tube boiler?

6.What is the basic purpose of any boiler?

7.What two fundamental processes must occur to achieve this objective?

8.What does the design of the boilers depend on?

9.How are boilers manufactured?

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ТЭ, ЭЭ, ТСБ, ПВ (IVсеместр)

AIR CONDITIONING

An air-conditioning cycle comprises several air-conditioning processes that are connected in a sequential order. The working substance to condition air may be chilled or hot water, refrigerant, desiccant, etc.

Air-conditioning cycles can be grouped into two categories: 1. Open cycle, in which the moist air at its end state does not resume its original state. An air conditioning cycle with all outdoor air is an open cycle. 2. Closed cycle, in which moist air resumes its original state at its end state. Air-conditioning cycle that conditions the mixture of recirculating and outdoor air, supplies it; recirculates part of the return air, and mixes it again with outdoor air is a closed cycle.

A basic air-conditioning system is a packaged system of supply air at a constant volume flow rate, serving a single zone, equipped with only a single supply/return duct.

Figure 5. A basic air-conditioning schematic for summer mode.

Here, return air from the conditioned space (2) mixes with required amount of outdoor air (1) at point (3) for acceptable indoor air quality and energy saving. The mixture is then cooled and dehumidified to (Apparatus Dew Point) ADP (4) at the cooling coil. The actual off-coil condition is represented (5) due to inefficiency (bypass) of cooling coil. The conditioned air is supplied to the room through the supply fan, supply duct, and ceiling diffuser (6). Supply air then absorbs the sensible and latent

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load from the space, becoming the space air (2). Room air is returned back to the cooling unit again and forms a closed cycle. Part of the return air is exhausted to balance the outdoor air intake and infiltration.

Figure 6. The psychrometric diagram below shows a typical winter cycle.

An air conditioning system has to handle a large variety of energy inputs and outputs in and out of the building where it is used. The efficiency of the system is essential to maintain proper energy balance. The system will operate properly if well maintained and operated.

Vocabulary:

cycle ['ÉÕIÐÎ] n.– цикл;

sequential order [ÉÁ"ÐÆÂÍ¿Î'² dq] – последовательный порядок; working substance ['wWkIN "sAbstqns] – рабочая среда;

refrigerant [ÏI'ÇÏI»qÏqÍË] n.– холодильная установка; desiccant ['ÌÂÉIÐqÍË] n.– поглотитель влаги/осушитель;

return air [rI'tWn 'eq] – отработанный/рециркулирующий воздух; supply air [sq'plaI 'eq] – поступающий/подаваемый воздух;

constant volume flow rate ["kPnstqnt "vPlj³ m "flqu 'reIt] – постоянная

величина скорости потока;

exhaust [ÁÑ'ʸ:ÉË] v.– выпускать/разрежать.

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Answer the following questions:

1.What working substance do you know ?

2.What can air-conditioning cycles be grouped into?

3.What cycle is called a closed cycle?

4.What is a basic air-conditioning system?

5.What does an air-conditioning cycle comprise?

6.How does a basic air-conditioning system work?

7.How is the conditioned air supplied to the room?

8.What forms a closed cycle?

9.Why is part of the return air exhausted?

10.What does an air conditioning system have to handle?

11.Why is the efficiency of the system essential?

12.In what case will the system operate properly?

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Оглавление

ABOUT MYSELF AND MY STUDY	3
BUILDING MATERIALS	6
SHEAR WALL AND FRAME SYSTEMS	7
BOULTON HOUSE, CAMBRIDGE, ENGLAND	9
SAINT PETERSBURG	12
URBAN DESIGN	15
ECO-ARCHITECTURE	17
COMPUTER SYSTEMS	19
THE WIDE WORLD WEB	21
COMPUTER SOFTWARE AND HARDWARE	23
INTERNAL COMBUSTION ENGINE	25
AUTOMOBILE SAFETY	26
HYBRID CARS	27
CRANES	29
EXCAVATORS	30
POWER INSTALLATIONS OF CONSTRUCTION
MACHINERY	32
PRICE ELASTICITY OF DEMAND AND SUPPLY	34
FISCAL POLICY	35
FOREIGN TRADE	36
HEAT EXCHANGERS	38
BOILERS	42
AIR CONDITIONING	45

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