III. Read the text “Widespread commercial use” and add some information in this table.

АНГЛИЙСКИЙ ЯЗЫК

ЛОПУХОВА В.Н.

УЧЕБНОЕ ПОСОБИЕ

для студентов II курса

специальности «Холодильная, криогенная техника и кондиционирование»

Астрахань 2010

 

Составитель:

В.Н.Лопухова, ассистент кафедры «Иностранные языки в инженерно-техническом образовании»

 

Рецензент:

О.В. Фёдорова, кандидат педагогических наук, заведующий кафедрой «Иностранные языки в инженерно-техническом образовании»,доцент

 

 

Учебное пособие предназначено для аудиторной и самостоятельной работы студентов II курса Механико-технологического института специальности «Холодильная, криогенная техника и кондиционирование». Основной целью пособия является овладение навыками чтения текстов профессиональной направленности.

В учебное пособие входят десять тематических разделов, каждый из разделов проиллюстрирован соответствующим текстами и комплексом упражнений, направленным на овладение навыками чтения, перевода и развития устной речи по определённым темам. Предлагаемые тексты содействуют дальнейшему закреплению полученных навыков и усвоению специальной терминологии.

Данное учебное пособие предоставляет широкий диапазон для активной аудиторной и внеаудиторной работы, имеет практическую ценность, отвечает современным требованиям методики обучения иностранному языку в вузе и может быть использован для студентов, углубленно изучающих язык по специальности: «Холодильная, криогенная техника и кондиционирование».

 

Сборник иностранных текстов утвержден на заседании кафедры “ИЯИТО” протокол №11 от 26.05.10.

© Астраханский государственный технический университет

UNIT 1

 

I. Read and translate the text:

[Show more]

Historical applications

The use of ice to refrigerate and thus preserve food goes back to prehistoric times. Through the ages, the seasonal harvesting of snow and ice was a regular practice of most of the ancient cultures: Chinese, Hebrews, Greeks, Romans, Persians. Ice and snow were stored in caves or dugouts lined with straw or other insulating materials. Rationing of the ice allowed the preservation of foods over the hot periods. This practice worked well down through the centuries, with icehouses remaining in use into the twentieth century.

In the 16th century, the discovery of chemical refrigeration was one of the first steps toward artificial means of refrigeration. Sodium nitrate or potassium nitrate, when added to water, lowered the water temperature and created a sort of refrigeration bath for cooling substances. In Italy, such a solution was used to chill wine.

The first known method of artificial refrigeration was demonstrated by William Cullen at the University of Glasgow in Scotland in 1748. Cullen used a pump to create a partial vacuum over a container of ethyl ether, which then boiled, absorbing heat from the surrounding air. The experiment even created a small amount of ice, but had no practical application at that time.

In 1805, American inventor Oliver Evans designed but never built a refrigeration system based on the vapor-compression refrigeration cycle rather than chemical solutions or volatile liquids such as ethyl ether.

Jacob Perkins, obtained the first patent for a vapor-compression refrigeration system in 1834. Perkins built a prototype system and it actually worked, although it did not succeed commercially.

In 1842, an American physician, John Gorrie, designed the first system for refrigerating water to produce ice. He also conceived the idea of using his refrigeration system to cool the air for comfort in homes and hospitals (i.e., air-conditioning). His system compressed air, then partially cooled the hot compressed air with water before allowing it to expand while doing part of the work required to drive the air compressor. That isentropic expansion cooled the air to a temperature low enough to freeze water and produce ice, or to flow "through a pipe for effecting refrigeration otherwise" as stated in his patent granted by the U.S. Patent Office in 1851. Gorrie built a working prototype, but his system was a commercial failure.

James Harrison introduced commercial vapor-compression refrigeration to breweries and meat packing houses. By 1861, a dozen of his systems were in operation. Australian, Argentinean and American concerns experimented with refrigerated shipping in the mid 1870s, the first commercial success coming when William Soltau Davidson fitted a compression refrigeration unit to the vessel in 1882.

The first gas absorption refrigeration system using gaseous ammonia dissolved in water was developed by Ferdinand Carrй of France in 1859 and patented in 1860. Due to the toxicity of ammonia, such systems were not developed for use in homes, but were used to manufacture ice for sale. In the United States, the consumer public at that time still used the ice box with ice brought in from commercial suppliers, many of whom were still harvesting ice and storing it in an icehouse.

Thaddeus Lowe, an American, held several patents on ice making machines. His "Compression Ice Machine" would revolutionize the cold storage industry. In 1869 he and other investors loaded one of Lowe’s refrigeration units onto an old steamship and began shipping fresh fruit from New York to the Gulf Coast area, and fresh meat from Galveston, Texas back to New York. Because of Lowe’s lack of knowledge about shipping, the business was a costly failure, and it was difficult for the public to get used to the idea of being able to consume meat that had been so long out of the packing house.

Domestic mechanical refrigerators became available in the United States around 1911.

 

 

Words to the text

to refrigerate - 1) охлаждать; замораживать; 2) хранить в холоде

harvesting - заготовка

to preserve - хранить (овощи, продукты)

insulating materials - изоляционные материалы

icehouse - ледник, льдохранилище (погреб со льдом или снегом, заготавливаемыми зимой для хранения продуктов в течение всего года)

artificial - искусственный

Sodium nitrate - нитрат натрия, натриевая селитра

cooling - охлаждение

substance - вещество

to chill - охлаждать, замораживать;

a pump - насос; помпа;

ethyl ether - этиловый эфир

to absorb - поглощать

heat - тепло; теплота

application - применение, использование,

vapor-compression refrigeration cycle - цикл паровой компрессионной холодильной машины

chemical solution - химический раствор

commercial - коммерческий, торговый;

brewery - пивоваренный завод

vessel - корабль, судно;

gas absorption - абсорбция газа, поглощение газов

ice box - холодильник

 

II. Fulfill the table using information from the text. (work in pairs or groups)

 

Date	Inventor / country	Refrigeration system	How does it work?	Application
Ancient ages	Chinese, Hebrews, Greeks, Romans, Persians	Harvesting of snow and ice	Snow & ice were stored in caves lined with straw or other insulating material	The preservation of foods over the hot periods
16 century	-
		The first method of artificial refrigeration
	Oliver Evans / the USA
				It didn’t succeed comercially
		The first system for refrigerating water
	James Harrison

 

I group (Yes/No-questions)

Was harvesting of snow and ice a regular practice of ancient cultures?

 

 

II group (Wh-questions)

What did Italian use to chill wine?

 

III group (Tag-question)

Ice harvesting became big business, didn’t it?

 

V. Skim through the text and say in one sentence what the message of the text is. Answer the questions which follow the text.

Refrigeration

Refrigeration is the process of removing heat from an enclosed space, or from a substance, and rejecting it elsewhere for the primary purpose of lowering the temperature of the enclosed space or substance and then maintaining that lower temperature. The term cooling refers generally to any natural or artificial process by which heat is dissipated. The process of artificially producing extreme cold temperatures is referred to as cryogenics.

Cold is the absence of heat, hence in order to reduce a temperature, one does not "add cold", rather one "removes heat." In order to satisfy the Second Law of Thermodynamics, some form of work must be performed to accomplish this. This work is traditionally done by mechanical work but can also be done by magnetism, laser or other means. However, all refrigeration uses the three basic methods of heat transfer: convection, conduction, or radiation.

Methods of refrigeration can be classified as non-cyclic, cyclic and thermoelectric.

Non-cyclic refrigeration: in these methods, refrigeration can be accomplished by melting ice or by subliming dry ice. These methods are used for small-scale refrigeration such as in laboratories and workshops, or in portable coolers.

Ice owes its effectiveness as a cooling agent to its constant melting point of 0 °C (32 °F). In order to melt, ice must absorb 333.55 kJ/kg (approx. 144 Btu/lb) of heat. Foodstuffs maintained at this temperature or slightly above have an increased storage life. Solid carbon dioxide, known as dry ice, is used also as a refrigerant. Having no liquid phase at normal atmospheric pressure, it sublimes directly from the solid to vapor phase at a temperature of -78.5 °C (-109.3 °F). Dry ice is effective for maintaining products at low temperatures during the period of sublimation.

Cyclic refrigeration: this consists of a refrigeration cycle, where heat is removed from a low-temperature space or source and rejected to a high-temperature sink with the help of external work, and its inverse, the thermodynamic power cycle. In the power cycle, heat is supplied from a high-temperature source to the engine, part of the heat being used to produce work and the rest being rejected to a low-temperature sink. This satisfies the second law of thermodynamics.

A refrigeration cycle describes the changes that take place in the refrigerant as it alternately absorbs and rejects heat as it circulates through a refrigerator. It is also applied to HVACR work, when describing the "process" of refrigerant flow through an HVACR unit, whether it is a packaged or split system.

Heat naturally flows from hot to cold. Work is applied to cool a living space or storage volume by pumping heat from a lower temperature heat source into a higher temperature heat sink. Insulation is used to reduce the work and energy required to achieve and maintain a lower temperature in the cooled space. The operating principle of the refrigeration cycle was described mathematically by Sadi Carnot in 1824 as a heat engine.

The most common types of refrigeration systems use the reverse-Rankine vapor-compression refrigeration cycle although absorption heat pumps are used in a minority of applications.

Cyclic refrigeration can be classified as:

1. Vapor cycle, and

2. Gas cycle

Vapor cycle refrigeration can further be classified as:

1. Vapor compression refrigeration

2. Gas absorption refrigeration

Thermoelectric refrigeration: thermoelectric cooling uses the Peltier effect to create a heat flux between the junction of two different types of materials. This effect is commonly used in camping and portable coolers and for cooling electronic components and small instruments.

Magnetic refrigeration (or adiabatic demagnetization) is a cooling technology based on the magnetocaloric effect, an intrinsic property of magnetic solids. The refrigerant is often a paramagnetic salt, such as cerium magnesium nitrate. The active magnetic dipoles in this case are those of the electron shells of the paramagnetic atoms.

A strong magnetic field is applied to the refrigerant, forcing its various magnetic dipoles to align and putting these degrees of freedom of the refrigerant into a state of lowered entropy. A heat sink then absorbs the heat released by the refrigerant due to its loss of entropy. Thermal contact with the heat sink is then broken so that the system is insulated, and the magnetic field is switched off. This increases the heat capacity of the refrigerant, thus decreasing its temperature below the temperature of the heat sink.

Because few materials exhibit the required properties at room temperature, applications have so far been limited to cryogenics and research.

Other methods of refrigeration include the Air cycle machine used in aircraft; the Vortex tube used for spot cooling, when compressed air is available; and Thermoacoustic refrigeration using sound waves in a pressurised gas to drive heat transfer and heat exchange.

 

ACTIVE VOCABULARY

refrigeration – охлаждение; замораживание

to remove – удалять, устранять

heat – теплота

to reject – отбрасывать

cooling – охлаждение

artificial - искусственный

to dissipate – рассеивать

to reduce - ослаблять, понижать, сокращать, уменьшать

to accomplish - совершать, выполнять; достигать

mechanical work - механическая работа

heat transfer - теплообмен; теплоотдача; теплопередача;

convection - конвекция

conduction - проводимость

radiation - излучение

non-cyclic – непериодический, нецикличный

cyclic - циклический, цикличный

thermoelectric - термоэлектрический

dry ice - сухой лёд

melting point - точка плавления

to absorb - абсорбировать; поглощать

refrigerant - охлаждающее вещество, охладитель

vapor - пар; пары; испарения;

to supply - поставлять; доставлять

engine - машина, двигатель; мотор

heat source - источник теплоты, тепловой источник

heat sink - теплоотвод, радиатор

insulation – изоляция, изоляционный материал

heat engine - тепловой двигатель

 

VII. Find the Russian equivalents for the English ones:

Second Law of Thermodynamics, subliming dry ice, a cooling agent, thermodynamic power cycle, HVACR, gas absorption refrigeration, thermoelectric cooling, adiabatic demagnetization, Vortex tube, spot cooling.

 

VIII. Find the English equivalents for the Russian ones:

талая вода, передвижная холодильная камера, точка плавления, атмосферное давление, уменьшать, абсорбционный тепловой насос, компрессионное охлаждение испарением холодильного агента, тепловой поток, парамагнитная соль, магнитное поле, теплоёмкость, теплообмен.

 

IX. Translate the following sentences into Russian:

 

1) The process of artificially producing extreme cold temperatures is referred to as cryogenics.

2) Ice owes its effectiveness as a cooling agent to its constant melting point of 0 °C (32 °F).

3) Dry ice is effective for maintaining products at low temperatures during the period of sublimation.

4) Heat is removed from a low-temperature space or source and rejected to a high-temperature sink with the help of external work.

5) Heat is pumped from a lower temperature heat source into a higher temperature heat sink.

6) The most common types of refrigeration systems use the reverse-Rankine vapor-compression refrigeration cycle.

7) Magnetic refrigeration is a cooling technology based on the magnetocaloric effect, an intrinsic property of magnetic solids.

8) The active magnetic dipoles are those of the electron shells of the paramagnetic atoms.

9) A heat sink absorbs the heat released by the refrigerant due to its loss of entropy.

10) Thermoacoustic refrigeration uses sound waves in a pressurised gas to drive heat transfer and heat exchange.

 

X. Fill in the blanks with appropriate words:

1) The term cooling refers generally to any … process.

2) All refrigeration uses the three basic methods of …: convection, conduction, or radiation.

3) Refrigeration can be accomplished by … or by … in the non-cyclic method.

4) Heat is supplied from a high-temperature … to the ….

5) The operating principle of the refrigeration cycle was described mathematically by … in 1824 as ….

6) Thermoelectric cooling uses the … effect.

7) The paramagnetic salt is often a refrigerant by … refrigeration.

8) Thermal contact with … is broken so that the system is insulated, and … is switched off.

9) … is used for spot cooling, when … air is available.

10) Foodstuffs maintained at low temperature have an increased ….

 

XI. Translate into English, using the active vocabulary:

 

1) Охлаждение – это процесс удаления теплоты из закрытого пространства.

2) Холод – это отсутствие тепла.

3) Методы охлаждения можно систематизировать как нецикличный, цикличный и термоэлектрический.

4) Нецикличные методы используются в лабораториях и мастерских для охлаждения небольших размеров.

5) Твёрдая углекислота, известная как сухой лед, используется в качестве охладителя.

6) Изоляционный материал уменьшает энергию, которая требуется для достижения низкой температуры.

7) Абсорбционный тепловой насос используется в меньшем объеме.

8) Эффект Пельтье как правило используют при охлаждении электронных компонентов и небольшого оборудования.

9) Сильное магнитное поле направляется на охладитель.

10) Когда магнитное поле отключается, это повышает теплоёмкость охладителя.

 

XII. Answer the questions:

 

1) What is refrigeration?

2) What process is cooling? What is cryogenics?

3) What form of work must be performed to reduce a temperature?

4) What methods of heat transfer does refrigeration use?

5) Where is non-cyclic refrigeration used? What is its refrigerant?

6) How does a refrigeration cycle work?

7) What is insulation used to?

8) How can cyclic refrigeration be classified?

9) What kinds of vapor cycle refrigeration do you know?

10) What does thermoelectric refrigeration use? Where is it used?

11) What is magnetic refrigeration based on? How does it work?

12) What other methods of refrigeration do you know?

 

XIII. Fulfill the table using information from the text:

 

Method	Refrigerant	How does it work?	Application

 

XIV. Tell in short about methods of refrigeration.

 

UNIT 2

 

I. Read and translate the text:

Boiling point

The boiling point of a liquid is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid. A liquid in a vacuum environment has a lower boiling point than when the liquid is at atmospheric pressure. And a liquid in a high pressure environment has a higher boiling point than when the liquid is at atmospheric pressure. In other words, all liquids have an infinite number of boiling points.

The normal boiling point (also called the atmospheric boiling point or the atmospheric pressure boiling point) of a liquid is the special case at which the vapor pressure of the liquid equals the ambient atmospheric pressure. At that temperature, the vapor pressure of the liquid becomes sufficient to overcome atmospheric pressure and lift the liquid to form bubbles inside the bulk of the liquid.

The heat of vaporization is the amount of heat required to convert or vaporize a saturated liquid (i.e., a liquid at its boiling point) into a vapor.

Liquids may change to a vapor at temperatures below their boiling points through the process of evaporation. Evaporation is a surface phenomenon in which molecules located near the vapor/liquid surface escape into the vapor phase. On the other hand, boiling is a process in which molecules anywhere in the liquid escape, resulting in the formation of vapor bubbles within the liquid.

A saturated liquid contains as much thermal energy as it can without boiling (or conversely a saturated vapor contains as little thermal energy as it can without condensing).

Saturation temperature means boiling point. The saturation temperature is the temperature for a corresponding saturation pressure at which a liquid boils into its vapor phase. The liquid can be said to be saturated with thermal energy. Any addition of thermal energy results in a phase change.

If the pressure in a system remains constant (isobaric), a vapor at saturation temperature will begin to condense into its liquid phase as thermal energy (heat) is removed. Similarly, a liquid at saturation temperature and pressure will boil into its vapor phase as additional thermal energy is applied.

The boiling point corresponds to the temperature at which the vapor pressure of the liquid equals the surrounding environmental pressure. Thus, the boiling point is dependent on the pressure. Usually, boiling points are published with respect to atmospheric pressure (101.325 kilopascals or 1 atm). At higher elevations, where the atmospheric pressure is much lower, the boiling point is also lower. The boiling point increases with increased pressure up to the critical point, where the gas and liquid properties become identical. The boiling point cannot be increased beyond the critical point. Likewise, the boiling point decreases with decreasing pressure until the triple point is reached. The boiling point cannot be reduced below the triple point.

Saturation Pressure, or vapor point, is the pressure for a corresponding saturation temperature at which a liquid boils into its vapor phase. Saturation pressure and saturation temperature have a direct relationship: as saturation pressure is increased so is saturation temperature.

If the temperature in a system remains constant (an isothermal system), vapor at saturation pressure and temperature will begin to condense into its liquid phase as the system pressure is increased. Similarly, a liquid at saturation pressure and temperature will tend to flash into its vapor phase as system pressure is decreased.

Note: The boiling point of water is 100 °C (212 °F) at standard pressure. On top of Mount Everest the pressure is about 260 mbar (26 kPa) so the boiling point of water is 69 °C. (156.2 °F). The normal boiling point of water is 99.97 degrees Celsius at a pressure of 1 atm (i.e., 101.325 kPa).

The element with the lowest boiling point is helium. Both the boiling points of rhenium and tungsten exceed 5000 K at standard pressure. Due to the experimental difficulty of precisely measuring extreme temperatures without bias, there is some discrepancy in the literature as to whether tungsten or rhenium has the higher boiling point.

 

ACTIVE VOCABULARY

boiling point – точка кипения

vapor pressure – давление пара

to equal – быть одинаковым, равным

atmospheric pressure – атмосферное давление

infinite – бесконечный, бесчисленный

sufficient – достаточный

to overcome (overcame, overcome) – побороть, победить

heat of vaporization – теплота испарения, теплота парообразования

to convert – преобразовывать; превращать

to contain – содержать в себе, включать

saturated vapor – насыщенный пар

saturation temperature – температура насыщения

saturation pressure – давление насыщения

vapor phase – паровая фаза

to remain – оставаться

constant – неизменный, устойчивый, константный

to correspond (to) – соответствовать; согласовываться, соотноситься

dependent on – обусловленный, зависящий (от обстоятельств)

with respect to – относительно, по отношению к

identical – такой же, одинаковый, идентичный

to reduce – понижать, уменьшать

isothermal – изотермический, изотермичный, равнотемпературный

helium – гелий

rhenium – рений

tungsten – вольфрам

to exceed – превышать; выходить за пределы

without bias – объективно

 

II. Find the Russian equivalents for the English ones:

saturated liquid, environmental pressure, discrepancy, a phase change, a liquid phase, atmospheric boiling point, the triple point, ambient atmospheric pressure, vapor point

 

III. Find the English equivalents for the Russian ones:

непосредственная связь, парообразная фаза, нормальное давление, точка кипения жидкости, насыщенный пар, бесконечное число, поверхностное явление, критическая точка

 

IV. Say whether these sentences are True or False:

1) A saturated vapor contains as little thermal energy as it can with boiling.

2) A liquid in a high pressure environment has a higher boiling point than when the liquid is at atmospheric pressure.

3) A vapor at saturation temperature and pressure will begin to condense into its liquid phase as thermal energy is removed.

4) At saturation pressure a vapor is converted into its liquid phase.

I group (Yes/No-questions)

Do all liquids have an infinite number of boiling points?

 

 

II group (Wh-questions)

What do all liquids have?

 

III group (Tag-question)

 

 

All liquids have an infinite number of boiling points, don’t they?

VII. Read and translate the text:

 

Cyclic refrigeration

 

The vapor-compression cycle is used in most household refrigerators as well as in many large commercial and industrial refrigeration systems.

The thermodynamics of the cycle can be analyzed on a diagram as shown in Figure 1. Figure 1

In this cycle, a circulating refrigerant such as Freon enters the compressor as a vapor. From point 1 to point 2, the vapor is compressed at constant entropy and exits the compressor superheated. From point 2 to point 3 and on to point 4, the superheated vapor travels through the condenser which first cools and removes the superheat and then condenses the vapor into a saturated liquid by removing additional heat at constant pressure and temperature. Between points 4 and 5, the saturated liquid refrigerant goes through the expansion valve (also called a throttle valve) where its pressure abruptly decreases. That process results in the adiabatic flash evaporation and auto-refrigeration of a portion of the liquid (typically, less than half of the liquid flashes). The adiabatic flash evaporation process is isenthalpic (i.e., occurs at constant enthalpy).

That results in a mixture of liquid and vapor at a lower temperature and pressure as shown at point 5. The cold liquid-vapor mixture then travels through the evaporator coil or tubes and is completely vaporized by cooling the warm air (from the space being refrigerated) being blown by a fan across the evaporator coil or tubes. The evaporator operates at essentially constant pressure. The resulting refrigerant vapor returns to the compressor inlet at point 1 to complete the thermodynamic cycle.

The above discussion is based on the ideal vapor-compression refrigeration cycle, and does not take into account real-world effects like frictional pressure drop in the system, slight thermodynamic irreversibility during the compression of the refrigerant vapor, or non-ideal gas behavior (if any).

Vapor absorption cycle: In the early years of the twentieth century, the vapor absorption cycle using water-ammonia systems was popular and widely used but, after the development of the vapor compression cycle, it lost much of its importance because of its low coefficient of performance (about one fifth of that of the vapor compression cycle). Nowadays, the vapor absorption cycle is used only where waste heat is available or where heat is derived from solar collectors.

The absorption cycle is similar to the compression cycle, except for the method of raising the pressure of the refrigerant vapor. In the absorption system, the compressor is replaced by an absorber which dissolves the refrigerant in a suitable liquid, a liquid pump which raises the pressure and a generator which, on heat addition, drives off the refrigerant vapor from the high-pressure liquid. Some work is required by the liquid pump but, for a given quantity of refrigerant, it is much smaller than needed by the compressor in the vapor compression cycle. In an absorption refrigerator, a suitable combination of refrigerant and absorbent is used. The most common combinations are ammonia (refrigerant) and water (absorbent), and water (refrigerant) and lithium bromide (absorbent).

Gas cycle: When the working fluid is a gas that is compressed and expanded but doesn't change phase, the refrigeration cycle is called a gas cycle. Air is most often this working fluid. As there is no condensation and evaporation intended in a gas cycle, components corresponding to the condenser and evaporator in a vapor compression cycle are the hot and cold gas-to-gas heat exchangers in gas cycles.

The gas cycle is less efficient than the vapor compression cycle because the gas cycle works on the reverse Brayton cycle instead of the reverse Rankine cycle. As such the working fluid does not receive and reject heat at constant temperature. In the gas cycle, the refrigeration effect is equal to the product of the specific heat of the gas and the rise in temperature of the gas in the low temperature side. Therefore, for the same cooling load, a gas refrigeration cycle will require a large mass flow rate and would be bulky.

Because of their lower efficiency and larger bulk, air cycle coolers are not often used nowadays in terrestrial cooling devices. The air cycle machine is very common, however, on gas turbine-powered 'jet' aircraft because compressed air is readily available from the engines' compressor sections. These jet aircrafts' cooling and ventilation units also serve the purpose of pressurizing the aircraft.

The Peltier effect uses electricity directly to pump heat; refrigerators using this effect are sometimes used for camping, or where noise is not acceptable. They are totally silent, but less energy-efficient than other methods.

Other alternatives to the vapor-compression cycle but not in current use include thermionic, vortex tube, magnetic cooling, Stirling cycle, acoustic cooling, pulse tube and water cycle systems.

 

ACTIVE VOCABULARY

vapor-compression cycle – парокомпрессионный цикл

compressor – компрессор

vapor – пар

to superheat – перегревать

condenser – конденсатор

liquid – жидкость

а expansion valve (a throttle valve) – регулирующий вентиль (для жидкого холодильного агента)

to decrease –уменьшаться

flash evaporation – мгновенное испарение

evaporator – испаритель

coil – спираль, змеевик

inlet – впуск, вход; входное отверстие

coefficient of performance – холодильный коэффициент (в компрессионной холодильной машине); тепловой коэффициент (в абсорбционной холодильной машине)

UNIT 3

I. Read and translate the text:

Icebox

An Icebox was the common appliance for providing refrigeration in the home before safe refrigerants made compact mechanical refrigerators useful.

Commonly iceboxes were made of wood, most probably for ease of construction, insulation, and aesthetics: many were handsome pieces of furniture.

Iceboxes had hollow walls that were lined with tin or zinc and packed with various insulating materials such as cork, sawdust, straw or seaweed. A large block of ice was held in a tray or compartment near the top of the box. Cold air circulated down and around storage compartments in the lower section. Some finer models had spigots for draining ice water from a catch pan or holding tank. In cheaper models a drip pan was placed under the box and had to be emptied at least daily.

Iceboxes date back to the days of ice harvesting which in a growing America had hit an industrial high that ran from the mid-19th century to the 1930s when the refrigerator was introduced into the home. Most municipally-consumed ice was harvested in winter from snow-packed areas or frozen lakes. Even Thoreau's Walden Pond was not spared from ice harvesting. The ice was stored in ice houses, or shipped as far as India by Frederic Tudor, the "Ice King".

With metropolitan growth many of the sources of natural ice became contaminated from industrial pollution or sewer runoff. As early mechanical refrigerators became available, they were installed as large industrial plants producing ice for home delivery. Able to produce clean, sanitary ice year-round, their product gradually replaced ice harvested from ponds.

With wide-spread electrification and safer refrigerants, mechanical refrigeration in the home became possible. With the development of the chlorofluorocarbons (along with the succeeding hydrochlorofluorocarbons and hydrofluorocarbons), that came to replace the use of toxic ammonia gas, the refrigerator replaced the icebox. However, because of the prevalence of the icebox in recent human history, the name "icebox" is still used colloquially for the modern home refrigerator by older Americans in some regions.

The horse-drawn ice wagon and the daily occupation of the iceman, who made regular door-to-door deliveries of block ice for iceboxes, was as much a social institution as the milk man.

Apartment buildings had small doors that opened to the ice box from the back porch. The ice man would bring the block of ice and insert it into the ice box through this door. Ice was delivered on a regular basis to these buildings and the people would pay for the ice. Children would go on the ice wagon and take chips of fallen ice as treats during the summer.

 

Words to the text:

I group (Yes/No-questions)

Was an icebox the common appliance for refrigerating in the home?

 

ACTIVE VOCABULARY

vapor-compression refrigeration – паровое компрессионное (парокомпрессионное) охлаждение

oil refinery – нефтеочистительный завод

to utilize – использовать, расходовать, употреблять

a device – устройство, приспособление

to perform – исполнять, выполнять; делать, совершать

a heat pump – тепловой насос

а expansion valve (a throttle valve) – регулирующий вентиль (для жидкого холодильного агента)

condensing coil – змеевиковый конденсатор

evaporator coil – испарительный змеевик; змеевик испарителя

refrigerator – рефрижератор, холодильник, холодильная установка

freezer – рефрижератор, холодильник, холодильная установка

interior – внутренняя часть

to drive (drove, driven) – приводить (к какому-л. состоянию)

evaporation – испарение

condensation – сжижение; конденсирование, конденсация

a compartment – отделение

a liquid – жидкость

heat exchanger – теплообменник

fan – вентилятор

medium – среда

a saturated vapor – насыщенный пар a superheated vapor – перегретый пар

to reject – отвергать, отклонять; отказываться

to undergo (underwent; undergone) – испытывать, переносить

adiabatic – адиабатический, адиабатный

to lower – снижать, уменьшать

to transfer – переносить, перемещать

to complete – завершать, заканчивать

refrigeration cycle – холодильный цикл

reciprocating – возвратно-поступательный

rotary screw – ротационный винтовой

centrifugal – центробежный

piston – поршень

displacement – объём чего-л.

to rotate – вращаться

velocity – скорость; быстрота

impeller – рабочее колесо

to convert – преобразовывать; превращать

a spiral – спираль,

to orbit – вращаться (по орбите)

 

V. Find the Russian equivalents for the English ones:

 

air-conditioning, to trap, large-scale warehouse, an abrupt reduction, condensing coil, to impart, a lower temperature source, discharge point, an impeller, saturation pressure, stationary spiral, heat exchange coil, piston-style, a saturated liquid, scroll compressor

 

VI. Find the English equivalents for the Russian ones:

 

Холодильный цикл, тепловой насос, энергия давления, испарительный змеевик, теплоотвод, воздушный карман, электродвигатель, температура насыщения, динамический компрессор, термодинамическое состояние, насыщенный пар, динамическая энергия, желательный, объёмный компрессор, объем охладителя

 

VII. Translate the following sentences into Russian:

 

1) Сhemical processing plants and natural gas processing plants often utilize large vapor-compression refrigeration systems.

2) Refrigeration may be defined as lowering the temperature of an enclosed space by removing heat from that space and transferring it elsewhere.

3) In an automobile the compressor is usually driven by a belt connected to a pulley on the engine's crankshaft, with both using electric motors for air circulation.

4) Air conditioners are designed to use a compressor to cause pressure changes between two compartments, and actively pump a refrigerant around.

5) In the condenser the refrigerant vapour is compressed and forced through another heat exchange coil, condensing into a liquid.

6) Circulating refrigerant enters the compressor in the thermodynamic state known as a saturated vapor and is compressed to a higher pressure.

7) The hot vapor is routed through a condenser where it is cooled and condensed into a liquid by flowing through a coil or tubes with cool water or cool air flowing across the coil or tubes.

UNIT 4

I. Read and translate the text:

 

History of the refrigerator

The first known artificial refrigeration was demonstrated by William Cullen at the University of Glasgow in 1748, and relied on the vapor-compression refrigeration process explained by Michael Faraday. Between 1805, when Oliver Evans designed the first refrigeration machine that used vapor instead of liquid, and 1902 when Willis Haviland Carrier demonstrated the first air conditioner, scores of inventors contributed many small advances in cooling machinery. In 1850 or 1851, Dr. John Gorrie demonstrated an ice maker. In 1857, Australian James Harrison introduced vapor-compression refrigeration to the brewing and meat packing industries. The absorption refrigerator was invented by Baltzar von Platen and Carl Munters in 1922, while they were still students at the Royal Institute of Technology in Stockholm, Sweden. It became a worldwide success and was commercialized by Electrolux. Other pioneers included Charles Tellier, David Boyle, and Raoul Pictet.

In a few exceptional cases, mechanical refrigeration systems had been adapted by the start of the 20th century for use in the homes of the very wealthy, and might be used for cooling both living and food storage areas. One early system was installed at the mansion of Walter Pierce, an oil company executive.

Marcel Audiffren of France championed the idea of a refrigerating machine for cooling and preserving foods at home. His U.S. patents, issued in 1895 and 1908, were purchased by the American Audiffren Refrigerating Machine Company. Machines based on Audiffren's sulfur dioxide process were manufactured by General Electric in Fort Wayne, Indiana and marketed by the Johns-Manville company. The first unit was sold in 1911. Audiffren machines were expensive, selling for about $1,000 — about twice as much as an automobile cost at the time.

General Electric sought to develop refrigerators of its own, and in 1915 the first unit was assembled. In 1916 Kelvinator and Servel came out with two units among a field of competing models. This number increased to 200 by 1920. In 1918, Kelvinator had a model with automatic controls.

These home units usually required the installation of the mechanical parts, motor and compressor, in the basement or an adjacent room while the cold box was located in the kitchen. There was a 1922 model that consisted of a wooden cold box, water-cooled compressor, an ice cube tray and a 9 cubic foot compartment for $714. (A 1922 Model-T Ford cost about $450.) In 1923 Frigidaire introduced the first self-contained unit. About this same time porcelain covered metal cabinets began to appear. Ice cube trays were introduced more and more during the 1920s; up to this time freezing was not a function of the modern refrigerator.

The first refrigerator to see widespread use was the General Electric "Monitor-Top" refrigerator introduced in 1927. The compressor assembly, which emitted a substantial amount of heat, was placed above the cabinet, and surrounded with a decorative ring. Over 1,000,000 units were produced. This refrigerator used sulfur dioxide refrigerant. Many units are still functional today.

The introduction of freon expanded the refrigerator market during the 1930s, and freezer units became a little more common and requested during the 1940s. Home units did not go into mass production until after WWII. The 1950s and 60s saw technical advances like automatic defrosting and automatic ice making. Developments of the 1970s and 80s brought about more efficient refrigerators, and environmental issues banned the use of CFC (freon) refrigerants.

Refrigerators used to consume more energy than any other home appliance, but in the last twenty years, great strides have been made to make refrigerators more energy efficient. Current models that are Energy Star qualified use 50 percent less energy than models made before 1993.

Introduction of home freezer units occurred in the United States in 1940, and frozen foods began to make the transition from luxury to necessity.

 

Words to the text

to rely – полагаться, надеяться

scores – множество

to contribute – вносить вклад

brewing – пивоварение

to install – устанавливать

mansion – большой особняк, большой дом

to issue – выходить

to purchase – покупать

sulfur dioxide – диоксид серы, сернистый ангидрид

to seek – искать, разыскивать; пытаться найти

 

competing – конкурирующий

adjacent – расположенный рядом, смежный, соседний

self-contained – смонтированный в общем корпусе

cabinet – шкаф

porcelain – фарфор

defrosting – размораживание

to bann – налагать запрет; запрещать

to consume - расходовать, тратить

Energy Star – стандарт экономичного энергопотребления электроприборов

 

II. Fulfill the table using information from the text. (work in pairs or groups)

 

Date	Inventor / firm	Refrigeration system	Features of refrigerator
Start of the 20^th century
1895 – 1908
1930s – 1940s
1950s – 1960s
1970s – 1980s
2000s

 

III. Make up different kinds of questions to the text. Ask your partner about historical application of refrigeration. (Work in pair or group)

 

I group (Yes/No-questions)

Did Carrier demonstrate the first air conditioner?

II group (Wh-questions)

When did Oliver Evans design the first refrigeration machine?

 

III group (Tag-question)

 

Dr. John Gorrie demonstrated an ice maker, didn’t he?

IV. Skim through the text and say in a few sentences what the message of the text is. Answer the questions which follow.

 

Refrigerator

A refrigerator (often called a "fridge" for short) is a cooling appliance comprising a thermally insulated compartment and a mechanism to transfer heat from it to the external environment, cooling the contents to a temperature below ambient. Refrigerators are extensively used to store foods which deteriorate at ambient temperatures; spoilage from bacterial growth and other processes is much slower at low temperatures. A device described as a "refrigerator" maintains a temperature a few degrees above the freezing point of water; a similar devices which maintains a temperature below the freezing point of water is called a "freezer". The refrigerator is a relatively modern invention amongst kitchen appliances. It replaced the common icebox which had been placed outside for almost a century and a half prior, and is sometimes still called by the original name "icebox".

Freezers keep their contents, usually foods, frozen. They are used both in households and for commercial use. Most freezers operate at around -18 °C (0 °F). Domestic freezers can be included as a compartment in a refrigerator, sharing the same mechanism or with a separate mechanism, or can be standalone units. Domestic freezers are generally upright units, resembling refrigerators, or chests, resembling upright units laid on their backs. Many modern freezers come with an icemaker.

Domestic refrigerators and freezers for food storage are made in a range of sizes. Amongst the smallest is a 4 L Peltier fridge advertised as being able to hold 6 cans of beer. A large domestic fridge stands as tall as a person and may be about 1 m wide with a capacity of 600 L. Some models for small households fit under kitchen work surfaces, usually about 86 cm high. Fridges may be combined with freezers, either stacked with fridge or freezer above, below, or side by side. A fridge without a true freezer may have a small compartment to make ice. Freezers may have drawers to store food in, or they may have no divisions (chest freezers).

Fridges and freezers may be free-standing, or built into a kitchen.

Compressor refrigerators are by far the most common type; they make a noticeable noise. Absorption or Peltier units are used where quiet running is required; Peltier coolers are used in the smallest refrigerators as they have no bulky mechanism.

Compressor and Peltier refrigerators are invariably powered by electricity; absorption units can in principle be designed to be powered by any heat source. Gas-only and dual power gas/electricity units are available.

Refrigeration units for commercial and for non-food use are made in a huge range of sizes and styles.

Newer refrigerators may include following features:

· Automatic defrosting: In any refrigerator, over time, water vapor in the air condenses onto the cooling coils as frost, eventually building up into a thick layer of ice. This ice acts as an insulator, reducing cooling efficiency. In the past, the ice was removed by periodically emptying the refrigerator and turning it off to let the ice melt, perhaps aided by hot water applied by the user (a process known as defrosting). In a refrigerator equipped for frost-free operation, however, a heater and a thermostat are fitted around the cooling coils. The cooling is periodically switched off (with the period varying between every 6 to 24 hours depending on the model) and the heater is turned on until the temperature around the coils slightly exceeds the freezing point of water, after which normal cooling resumes. This melts any frost which has collected around the coils. Melt water drops into a small gulley, through a small pipe which drains into a tray on the top of the compressor from which it is then evaporated into the surrounding air by residual heat generated by the operation of the compressor.

· A power failure warning, alerting the user by flashing a temperature display. The maximum temperature reached during the power failure may be displayed, along with information on whether the frozen food has defrosted or may contain harmful bacteria;

· Chilled water and ice available from an in-door station, so the door need not be opened;

· Adjustable shelves and trays that can be moved around to suit the user;

· A cooling zone in the refrigerator door shelves. Air from the freezer section is diverted to the refrigerator door, to better cool milk or juice stored in the door shelf.

Early freezer units accumulated ice crystals around the freezing units. This was a result of humidity introduced into the units when the doors to the freezer were opened. This build up of frost required periodic thawing of the units to maintain their efficiency. Advances in frost-free refrigeration eliminating the thawing task were introduced in the 1950s. Also, early units featured freezer compartments located within the larger refrigerator, and accessed by opening the refrigerator door, and then the smaller internal freezer door; units featuring entirely separate freezer compartment were introduced in the early 1960s, becoming the industry standard by the middle of that decade.

Old refrigerators have freon as coolant, which damages the ozone layer. Now modern refrigerators usually use a refrigerant called HFC-134a (1,2,2,2-tetrafluoroethane) instead of freon, which has no ozone layer depleting properties.

ACTIVE VOCABULARY

 

refrigerator (a "fridge") – рефрижератор, холодильник, холодильная установка

to deteriorate – ухудшать; портить

a compartment – отделение

standalone – автономный

freezer – морозильная камера

upright – вертикальный

icemaker – льдогенератор

to transfer – переносить, перемещать

to store – хранить, сохранять

spoilage – порча или гниение пищевых и скоропортящихся продуктов

a device – устройство, приспособление; механизм

to maintain – поддерживать, сохранять

appliance – аппарат, прибор;

a capacity – вместимость, ёмкость

to power – приводить в действие

defrosting – размораживание; оттаивание

to empty – осушать

a heater – обогреватель; нагревательный прибор

exceed – превышать; переступать пределы, границы; выходить за пределы

freezing point – точка замерзания

to resume – возобновлять, продолжать

to melt – таять

to drain – отводить воду

to chill – охлаждать, замораживать

to accumulate – накапливать; собирать

thawing – таяние, оттаивание

coolant – смазочно-охлаждающая эмульсия

 

VI. Find the Russian equivalents for the English ones:

comprising, icebox, a cooling appliance, a thermally insulated compartment, а upright unit, drawer, free-standing, Peltier cooler, dual power gas/electricity unit, frost-free operation, freezing unit.

 

VII. Find the English equivalents for the Russian ones:

внешняя среда, температура окружающей среды, отдельный механизм, автономное устройство, хранение продовольствия, приводить в действие электричеством, автоматическое размораживание, холодопроизводительность, водосток, остаточное тепло, сигнал о нарушении энергоснабжения.

 

VIII. Translate the following sentences into Russian:

 

1) A refrigerator has a mechanism to transfer heat from it to the external environment, cooling the contents to a temperature below ambient.

2) Domestic freezers are generally upright units, resembling refrigerators, or chests, resembling upright units laid on their backs.

3) A large domestic fridge stands as tall as a person and may be about 1 m wide with a capacity of 600 L.

4) Fridges and freezers may be free-standing, or built into a kitchen.

5) Peltier coolers are used in the smallest refrigerators as they have no bulky mechanism.

6) In any refrigerator, over time, water vapor in the air condenses onto the cooling coils as frost, eventually building up into a thick layer of ice.

7) By frost-free operation the cooling is periodically switched off and the heater is turned on until the temperature around the coils slightly exceeds the freezing point of water, after which normal cooling resumes.

8) A power failure warning alerts the user by flashing a temperature display.

9) Air from the freezer section is diverted to the refrigerator door, to better cool milk or juice stored in the door shelf.

10) The accumulation of ice crystals was a result of humidity introduced into the units when the doors to the freezer were opened.

 

IX. Fill in the blanks with appropriate words:

 

1) … from bacterial growth and other processes is much slower at ….

2) Freezers keep their … frozen.

3) Freezers may have … to store food in, or they may have no ….

4) … are used where quiet running is required.

5) Аbsorption units can in principle be designed to be powered by ….

6) Тhe ice was removed by … the refrigerator and … to let the ice melt.