Van hanh sua chua thiet bi lanh 14 179

UBND THÀNH PHỐ CẦN THƠ TRƯỜNG CAO ĐẲNG NGHỀ CẦN THƠ GIÁO TRÌNH MƠN HỌC: ANH VĂN CHUN NGÀNH NGHỀ: VẬN HÀNH SỬA CHỮA THIẾT BỊ LẠNH TRÌNH ĐỘ: CAO ĐẲNG Ban hành kèm theo Quyết định số: /QĐ-CĐNCT ngày ….tháng năm 2021 Hiệu trưởng trường Cao đẳng nghề Cần Thơ Cần Thơ, năm 2021 (Lưu hành nội bộ) TUYÊN BỐ BẢN QUYỀN Tài liệu thuộc loại sách giáo trình nên nguồn thơng tin phép dùng nguyên trích dùng cho mục đích đào tạo tham khảo Mọi mục đích khác mang tính lệch lạc sử dụng với mục đích kinh doanh thiếu lành mạnh bị nghiêm cấm LỜI GIỚI THIỆU Trong chương trình đào tạo nghề Kỹ thuật máy lạnh điều hịa khơng khí, tiếng Anh chun ngành có vị trí đặc biệt quan trọng, bối cảnh hội nhập hợp tác quốc tế tiếng Anh chun ngành cịn phục vụ trực tiếp cho việc học tập nghiên cứu sinh viên lĩnh vực điện lạnh Giáo trình ANH VĂNCHUYÊN NGÀNH biên soạn dành cho sinh viên ngành Vận hành sửa chữa thiết bị lạnh, học tiếp sau học môn học Ngoại ngữ (Tiếng Anh bản) để đáp ứng nhu cầu học tập nghiên cứu sinh viên Giáo trình biên soạn với thời lượng 45 gồm có bài: Unit 1: Engineering - what's it all about? Unit 2: Engineering materials Unit 3: Safety at work Unit 4: Fundamentals of refrigeration Unit 5: Compressors Unit 6: Air-conditioning Unit 7: Refrigerator Giáo trình biên soạn với tham khảo tài liệu đóng góp tận tình đồng nghiệp mơn Tuy nhiên giáo trình khơng thể tránh khỏi thiếu sót Rất mong đóng góp ý kiến đồng nghiệp, sinh viên bạn đọc quan tâm đến giáo trình Cần Thơ, ngày .tháng năm 2021 Tham gia biên soạn Lê Thanh Tuyền Trần Minh Khoa MỤC LỤC Trang Lời giới thiệu Unit 1: Engineering - what's it all about? Unit 2: Engineering materials Unit 3: Safety at work 14 Unit 4: Fundamentals of refrigeration 20 Unit 5: Compressors 26 Unit 6: Air-conditioning 33 Unit 7: Refrigerator 41 Reference 48 GIÁO TRÌNH MƠN HỌC Tên mơn học: ANH VĂN CHUYÊN NGÀNH Mã môn học: MH 20 Vị trí, tính chất, ý nghĩa vai trị mơn học: - Vị trí: Mơn học Anh văn chun ngành môn học áp dụng khối đào tạo kỹ thuật cụ thể thường bố trí thực sau học sinh học xong phần tiếng Anh bản; - Tính chất: mơn học bắt buộc - Vai trị: Ngoại ngữ ln quan trọng lĩnh vực tiếng Anh không giúp cho người học tìm hiểu chun sâu lĩnh vực mình, mà cịn giúp người học mở rộng cánh cửa cho đường tương lai nghề nghiệp Mục tiêu môn học: ➢ Về kiến thức: - Củng cố lại kiến thức kỹ mà sinh viên học học phần tiếng Anh - Hiểu đựơc mở rộng cấu trúc ngữ pháp từ vựng chuyên ngành Vận hành sửa chữa thiết bị lạnh thông dụng, ý tới yếu tố liên kết văn tiếng Anh - Mở rộng đựợc vốn từ vựng chuyên ngành Vận hành sửa chữa thiết bị lạnh ➢ Về kỹ - Phát triển kỹ theo hệ thống chủ điểm gắn liền với hoạt động chuyên ngành Vận hành sửa chữa thiết bị lạnh, đặc biệt phát triển kỹ đọc, dịch, hiểu - Xây dựng rèn luyện kỹ học tập ngoại ngữ đồng thời hình thành phát triển khả độc lập suy nghĩ sáng tạo giao tiếp tiếng Anh cho sinh viên - Phát triển kỹ làm việc theo cặp, theo nhóm - Định hướng cho sinh viên tầm quan trọng tiếng Anh sống công việc tương lai ➢ Về lực tự chủ trách nhiệm - Rèn luyện tính cẩn thận, xác q trình làm việc - Rèn luyện tính khoa học, tính sáng tạo giao tiếp Nội dung môn học: UNIT 1: ENGINEERING – WHAT’S IT ALL ABOUT ? Mã bài: MH 20- 01 Giới thiệu: Ngành kỹ thuật vơ rộng, bao gồm loạt lĩnh vực kỹ thuật đặc thù, lĩnh vực nhấn mạnh đến lĩnh vực công nghệ kiểu ứng dụng riêng Hiện có nhiều ngành nghề liên quan đến kỹ thuật người hành nghề kỹ thuật gọi kỹ sư Mục tiêu: Sau học xong người học có khả năng: - Trình bày ngành kỹ thuật - Xác định mục đích trước đọc - Sử dụng cấu trúc deals/is concerned with Nội dung: Tuning - in Task 1: List the main branches of engineering Combine your list with others in your group Then read this text to find out how many of the branches listed are mentioned Engineering is largely a practical activity It is about putting ideal into action Civil engineering is concerned with making bridges, roads, airports, etc Mechanical engineering deals with the design and manufacture of tools and machines Electrical engineering is about the generation and distribution of electricity and its many applications Electronic engineering is concerned with developing components and equipment for communications, computing, and so on Mechanical engineering includes marine, automobile, aeronautical, heating and ventilating, and others Electrical engineering is includes electricity generating, electrical installation, lighting, etc Mining and medical engineering belong to partly to mechanical and partly to electrical Task 2: Complete the blanks in this diagram using information from the text Engineering Civil _ _ Automobile Electrical Heating and ventilating Electricity _ _ Electrical installation _ _ Medical Reading Introduction In your study and work, it is important to think about what you are going to read before you read This helps you to link old and new knowledge and to make guesses about the meaning of the text It is also important to have a clear purpose so that you choose the best way to read In this book, you will find tasks to make you think before you read and tasks to help you to have a clear purpose when you read Task 3: Study these illustrations They show some of the areas in which engineers work Can you identify them? What kinds of engineers are concerned with these areas - electrical, mechanical, or both? Task 4: Now read the following texts to check your answers to Task Match each text to one of the illustrations above Transport: Cars, trains, ships, and planes are all products of mechanical engineering Mechanical engineers are also involved in support services such as roads, rail track, harbours, and bridges Food processing: Mechanical engineers design, develop, and make machines and processing equipment for harvesting, preparing, and preserving the foods and drinks that fill the supermarkets Medical engineering: Body scanners, X-ray machines, life-support systems, and other high-tech equipment result from mechanical and electrical engineers combining with medical experts to convert ideals into life-saving and life-preserving products Building services: Electrical engineers provide all the services we need in our homes and places of work include lighting, ventilation, air-conditioning, refrigeration, and lifts Energy and power: Electrical engineers are concerned with the production and distribution of electricity to homes, offices, industry, hospitals, colleges and schools, and the installation and maintenance of the equipment involved in these processes Language study: deals / is concerned with What is the link between column A and column B? A B Mechanical machines Electrical electricity Column A lists a branch of engineering or a type of engineer Column B lists things they are concerned with We can show the link between them in a number of ways: Mechanical engineering deals with machines Mechanical engineers deal with machines Mechanical engineering is concerned with machines Mechanical engineers are concerned with machines Machines are the concern of mechanical engineers Task 5: Match each item in column A with an appropriate item from column B and link the two in a sentence A B marine a air-conditioning aeronautical b roads and bridges heating and ventilating c body scanners electricity generating d cables and switchgear automobile e communications and equipment civil f ships electronic g planes electrical installation h cars and trucks medical i power stations Writing: describing diagrams Task 7: Fill in the gaps in the following description of the different branches of engineering using information from this diagram and language you have studied in this unit The main branches of engineering are civil,1 ,electrical, and electronic Mechanical engineering is with machinery of all kinds This branch of engineering includes , automobile, aeronautical, and heating and ventilating The first three are concerned with transport: _, cars and planes The last with air- conditioning, refrigeration, etc Electrical engineering deals with from generation to use Electricity generating is concerned with to _stations Electrical installation deals cables, switchgear, and connecting electrical equipment Two branches of engineering include both mechanical and _ engineers These are mining and 10 engineering The former deals with mines and mining equipment, the latter with hospital machinary of all kinds HOMEWORK FURTHER READING What is Engineering? Engineers use science and math to come up with practical solutions to problems (Image credit: Ollyy | Shutterstock ) Engineering is the application of science and math to solve problems Engineers figure out how things work and find practical uses for scientific discoveries Scientists and inventors often get the credit for innovations that advance the human condition, but it is engineers who are instrumental in making those innovations available to the world In his book, "Disturbing the Universe" (Sloan Foundation, 1981), physicist Freeman Dyson wrote, "A good scientist is a person with original ideas A good engineer is a person who makes a design that works with as few original ideas as possible There are no prima donnas in engineering." The history of engineering is part and parcel of the history of human civilization The Pyramids of Giza, Stonehenge, the Parthenon and the Eiffel Tower stand today as monuments to our heritage of engineering Today's engineers not only build huge structures, such as the International Space Station, but they are also building maps to the human genome and better, smallercomputer chips Engineering is one of the cornerstones of STEM education, an interdisciplinary curriculum designed to motivate students to learn about science, technology, engineering and mathematics Yêu cầu đánh giá kết học tập chương Nội dung: + Về kiến thức: Nhận biết ngành kỹ thuật thông qua công việc đặc trưng + Về kỹ năng: Biết cách sử dụng cấu trúc ngữ pháp đề cập + Năng lực tự chủ trách nhiệm: Tỉ mỉ, cẩn thận, xác, ngăn nắp công việc Phương pháp: + Về kiến thức: Được đánh giá hình thức kiểm tra viết, trắc nghiệm + Về kỹ năng: Ứng dụng kiến thức để đọc tài liệu liên quan + Năng lực tự chủ trách nhiệm: Tỉ mỉ, cẩn thận, xác, ngăn nắp công việc Figure 6.2: Central air conditioning systems A refrigerator works in much the same way, as it pumps the heat out of the interior and into the room in which it stands This cycle takes advantage of the way phase changes work, where latent heat is released at a constant temperature during a liquid/gas phase change,and where varying the pressure of a pure substance also varies its condensation/ boiling point UNDERSTANDING THE PASSAGE Task Answer the following questions What is an air conditioning ? ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… What is the cooling done ? ……………………………………………………………………….…………………………… ………………………………………………………………………… ………………………… Where would heat naturally flow? ……………………………………………………………………………… …………………… ………………………………………………………………………………………………….… Where is a refrigerant pumped? ………………………………………………………………………………………….…………… ………………………………………………………………………………………………….…… What is usually called a heat pump? ………………………………………………………………………………………….…………… ………………………………………………………………………………………………….…… What are the cylinder unloaders ? ………………………………………………………………………………………….…………… 34 ………………………………………………………………………………………………….…… Where can the heads be fitted with unloaders? ………………………………………………………………………………………….…………… ………………………………………………………………………………………………….…… Where is the refrigerant vapor compressed? …………………………………………….………………………………………………………… ……………………………………………….……………………………………………………… What is a heat pump capable of doing? ………………………………………….…………………………………………………………… ………………………………………….…………………………………………………………… 10 What can unloaders be ? ……………………………………………… …………………………………………………… …………………………………………… ……………………………………………………… Task Are the following statements true or false? Correct the false sentences An air conditioner (often referred to as AC) is a home appliance ………………………………………………….…………………………………………… …………………………………………………….………………………………………… In installation, a complete system of heating, ventilation and air conditioning is referred to as "HVAC" ………………………………………………… …………………………………………… ………………………………………………… …………………………………………… A heat pump transfers heat from a higher-temperature heat source into a lower -temperature heat sink ………………………………………………………… …………………………………… ………………………………………………………… …………………………………… The compressor is driven by a belt over a pulley, the belt being driven by the engine's crankshaft …………………………………………………… ………………………………………… ……………………………………………………………………………………………… The refrigerant liquid is compressed and forced through another heat exchange coil, condensing the refrigerant into a vapor ………………………………………………………… …………………………………… …………………………………………………………… ………………………………… A heat source is capable of heating a home to comfortable temperatures 35 ……………………………………………………………… ……………………………… ………………………………………………………………… …………………………… A refrigerant is pumped into the evaporator coil ………………………………………………………… …………………………………… The evaporator releases heat in the ambient environment ………………………………………………………………… …………………………… ……………………………………………………………… ……………………………… The unloaders keep a portion of the load from the compressor …………………………………………………………… ………………………………… …………………………………………………………… ………………………………… 10 Whether in a car or building, both use electric fan motors for air circulation …………………………………………………………… ………………………………… ……………………………………………………………… ……………………………… Task Choose the best answer A heat …………… is capable of heating a home to comfortable temperatures A refrigerator B compressor C pump D pressure The is driven by a belt over a pulley, the belt being driven by the engine's crankshaft A pump B pressure C refrigerator D compressor A refrigerator the heat out of the interior and into the room A transfers B causes C pumps D use The low pressure the refrigerant to evaporate into a vapor A causes B use C transfers D pumps A heat pump … heat from a lower-temperature heat source into a highertemperature heat sink A pumps B use C causes D transfers The air conditioners … a compressor to cause pressure changes between two compartments A transfers B causes C pumps D use The refrigerant vapor is … and forced through another heat exchange coil A released B fitted C compressed D pumped The latent heat is ……… at a constant temperature during a liquid/gas phase change A pumped B released C fitted D compressed The heads can be …… with unloaders which remove a portion of the load from the compressor A fitted B released C compressed D pumped 10 A refrigerant is into the evaporator coil A released B fitted C pumped D compressed 36 Language study Prepositions of place and direction Preposition Use Examples among in a group I like being among people below lower than sth Death Valley is 86 metres below sea level beside Our house is beside the supermarket Our house is between the supermarket and the school He lives in the house by the river Do you come from Tokyo? from next to sth./sb is on each side near the place where it starts inside opposite of outside You shouldn't stay inside the castle into entering sth You shouldn't go into the castle next to beside Our house is next to the supermarket onto moving to a place The cat jumped onto the roof opposite on the other side Our house is opposite the supermarket out of leaving sth The cat jumped out of the window outside opposite of inside Can you wait outside? over above sth./sb The cat jumped over the wall between by through to going from one point You shouldn't walk through the forest to the other point I like going to Australia Can you come to me? towards sth./sb I've never been to Africa Examples - A refrigerator works in much the same way, as it pumps the heat out of the interior and into the room in which it stands - At the opposite side of the cycle is the condenser, which is located outside of the cooled compartment - By placing the condenser (where the heat is rejected) inside a compartment, and the evaporator (which absorbs heat) in the ambient environment (such as outside), or merely running a normal air conditioner's refrigerant in the opposite direction, the overall effect is the opposite, and the compartment is heated PRACTICE Exercise Rearrange these words to make the sentences plant /Paper/ at/ stock/ the /would/ absorb / moisture /sometimes /from/ 37 summer/ the /air./warm ………………………………………………………………………………………………… ………………………………………………………………………………………………… refrigerant/ pumped /A / coil/ is /into /evaporator / the ……………………………………………………………………………………………… ……………………………………………………………………………………………… evaporation /occurs /Since / is /when/ absorbed./ heat ……………………………………………………………………………………………… ……………………………………………………………………………………………… of/ heat/ is /A /pump /capable /heating/ home/ a /to / temperatures./comfortable ……………………………………………………………………………………………… ……………………………………………………………………………………………… remove / unloaders /a/ The/ of/ portion /the/ compressor./ load/ the/ from ……………………………………………………………………………………………… ……………………………………………………………………………………………… Exercise Match the words in A to the appropriate phrase in B A B An air conditioner a heat is absorbed HVAC b capable of heating a home to comfortable temperatures A refrigerator c the side temperature evaporation d heating, ventilation and air conditioning condensation e pumps the heat out of the interior a heat pump f reduces the humidity of the air Cylinder unloaders g a home appliance unloaders h a method of load control Reducing the humidity i heat is released 10 Air equipment benefit of lowering the air conditioning j remove a portion of the load from the compressor Exercise Put a word to a suitable space to complete the passage units ; evaporator ; water; exchanger; humidity; cooler ; Humidity Air conditioning equipment usually reduces the …… of the air processed by the system The relatively cold (below the dew point) 38 ……… coil condenses water vapor from the processed air, much as a cold drink will condense water on the outside of a glass The water is drained, removing ……… vapor from the cooled space and thereby lowering its relative humidity Some air conditioning………… dry the air without cooling it These work like a normal air conditioner, except that a heat ………… is placed between the intake and exhaust In combination with convection fans, they achieve a similar level of coolness as an air ……… in humid tropical climates, but only consume about one-third the energy Exercise Translate the sentences into Vietnamese The first modern air conditioning system was developed in 1902 by a young electrical engineer named Willis Haviland Carrier It was designed to solve a humidity problem at the Sackett-Wilhelms Lithographing and Publishing Company in Brooklyn, N.Y ……………………………………………… …………………………………… ……………………………………………………………………… …………… ……………………………………………………………………………………… .……………………………………………………………………………………… In the refrigeration cycle, a heat pump transfers heat from a lowertemperature heat source into a higher-temperature heat sink Heat would naturally flow in the opposite direction This is the most common type of air conditioning A refrigerator works in much the same way, as it pumps the heat out of the interior and into the room in which it stands ……………………………………………… …………………………………… ……………………………………………………………………… …………… ……………………………………………………………………………………… .……………………………………………………………………………………… The most common refrigeration cycle uses an electric motor to drive a compressor In an automobile, the compressor is driven by a belt over a pulley, the belt being driven by the engine's crankshaft (similar to the driving of the pulleys for the alternator, power steering, etc.) …………………………………………… ………… …………………………… …………………………………………………… ………………… …………… ……………………………………………………………………………………… .……………………………… …………………… ……………………………… By placing the condenser (where the heat is rejected) inside a compartment, and the evaporator (which absorbs heat) in the ambient environment (such as outside), or merely running a normal air conditioner's refrigerant in the opposite direction, the overall effect is the opposite, and the compartment is heated ……………………………………………… …………………………………… ……………………………………………………………………… …………… ……………………………………………………………………………………… .……………………………………………………………………………………… Cylinder unloaders are a method of load control used mainly in commercial air conditioning systems On a semi-hermetic (or open) compressor, the heads can be fitted with unloaders which remove a portion of the load from the compressor so that it can run better when full cooling is not needed Unloaders can be electrical or mechanical 39 …………………………………………………… ……………………………… …………………………………………………………………………… ……… ……………………………………………………………………………………… ……………………………………………………………………………………… …………………………………………………………………… ……………… ……………………………………………………………………………………… A refrigerator works in much the same way, as it pumps the heat out of the interior and into the room in which it stands ……………………………………………………………………… ………………… ………………………………………………………………………………………… ………………………………………………………………………………………… HOMEWORK FURTHER READING HOW DOES AIR CONDITIONING WORK? Air conditioning units work by removing the warm air from inside your home and pumping it outside, while releasing the cool air back into the room, reducing the temperature When liquid becomes gas, it absorbs heat, and in principle, this is how they function Air conditioning systems work very much in the same way as your standard refrigerator, in that heat is absorbed inside the system and then removed from the room Here’s the process: • Firstly, the warm air from the room is drawn into the system • This air flows over the cold evaporator pipes inside, which cools the air down while a dehumidifier removes excess moisture • Meanwhile, the coolant flowing through the chiller pipes absorbs the heat from the air blowing past and evaporates, turning from a cool liquid to a warm gas • This warm air is pumped outside while the coolant flows through a compressor unit and a condenser, which turn it back into a cool liquid • Cold air is then re-circulated into the room where it mixes with the existing air and reduces the temperature and humidity Inside a unit, there are a number of different components that manipulate the state, pressure, and temperature of the refrigerant, allowing the unit to its job and cool the room Yêu cầu đánh giá kết học tập chương Nội dung: + Về kiến thức: Trình bày ngun lý hoạt động điều hịa khơng khí + Về kỹ năng: Biết cách sử dụng cấu trúc ngữ pháp đề cập + Năng lực tự chủ trách nhiệm: Tỉ mỉ, cẩn thận, xác, ngăn nắp cơng việc Phương pháp: + Về kiến thức: Được đánh giá hình thức kiểm tra viết, trắc nghiệm + Về kỹ năng: Ứng dụng kiến thức để đọc tài liệu liên quan + Năng lực tự chủ trách nhiệm: Tỉ mỉ, cẩn thận, xác, ngăn nắp cơng việc 40 UNIT 7: REFRIGERATOR Mã bài: MH 20- 07 Giới thiệu: Hiện nay, tủ lạnh thiết bị thiếu gia đình Tủ lạnh thiết bị điện lạnh mà hầu hết gia đình sở hữu với lợi ích như: Giúp dự trữ thực phẩm thời gian dài, tươi lâu, đảm bảo dưỡng chất Trữ đông loại thực phẩm, thịt, cá ngăn đơng ln tươi ngon Có thể làm đá uống nước làm mát nước Mục tiêu: - Trình bày nguyên lý làm việc tủ lạnh - Trình bày cách sử dụng cấu trúc If/When để mơ tả ngun lý - Trình bày bước để mơ tả q trình Nội dung: Tuning - in Task 1: Study this diagram It explains how a refrigerator works In your group try to work out the function of each of the numbered components using the information in the diagram Figure 7.1: Refrigerator Reading: Dealing with unfamiliar words, You are going to read a text about refrigerators Your purpose is to find out how they operate Read the first paragraph of the text below Underline any words which are unfamiliar to you 41 Refrigeration preserves food by lowering its temperature It slows down the growth and reproduction of micro-organisms such as bacteria and the action of enzymes which cause food to rot You may have underlined words like micro-organisms, bacteria, or enzymes These are words which are uncommon in engineering Before you look them up in a dictionary or try to find translations in your own language, think! Do you need to know the meaning of these words to understand how refrigerators operate? You can ignore unfamiliar words which not help you to achieve your reading purpose Task 2: Now read the text to check your explanation of how a refrigerator works Ignore any unfamiliar words which will not help you to achieve this purpose Fridge Refrigeration preserves food by lowering its temperature It slows down the growth and reproduction of micro-organisms such as bacteria and the action of enzymes which cause food to rot Refrigeration is based on three principles Firstly, if a liquid is heated, it changes to a gas or vapour When this gas is cooled, it changes back into a liquid Secondly, if a gas is allowed to expand, it cools down If a gas is compressed, it heats up Thirdly, lowering the pressure around a liquid helps it to boil To keep the refrigerator at a constant low temperature, heat must be transferred from the inside of the cabinet to the outside A refrigerant is used to this It is circulated around the fridge; where it undergoes changes in pressure and temperature, a changes from a liquid to a gas and back again One common refrigerant is a compound of carbon, chlorine, and fluorine is known as R12 This has a very low boiling point: -290C at normal room temperature (about 200C) the liquid quickly turns into gas However, newer refrigerants which are less harmful to the environment, such as KLEA 134a, are gradually replacing R12 The refrigeration process begins in the compressor This compresses the gas so that it heats up It then pumps the gas into condenser, a long tube in the shape of a zigzag As the warm gas passes through the condenser, it heats the surroundings and cools down By the time it leaves the condenser, it has condensed back into a liquid Liquid leaving the condenser has to flow down a very narrow tube (a capillary tube) This prevents liquid from leaving the condenser too quickly, and keeps it at a high pressure As the liquid passes from the narrow capillary tube to the larger tubes of the evaporator, the pressure quickly drops The liquid turns to vapour, which expands and cools The cold vapour absorbs heat from the fridge It is then sucked back into the compressor and the process begins again The compressor is switched on and off by a thermostat, a device that regulates temperature, so that the food is not over-frozen Language study: Principles and laws Study these extracts from the text above What kind of statements are they? If a liquid is heated, it changes to a gas or vapour If a gas is allowed to expand, it cools down If a gas is compressed, it heats up Each consists of an action followed by a result For example: Action Result a liquid is heated it changes to a gas or vapour 42 These statements are principles They describe things in science and engineering which are always true The action is always followed by the same result Principles have this form: If / When (action - present tense), (result - present tense) Task 3: Link each action in column A with a result from column B to describe an important engineering principle A Action B Result a liquid is heated a it heats up a gas is cooled b there is an equal and opposite a gas expands reaction a gas is compressed c it changes to a gas a force is applied to a body d it extends in proportion to the force a current passes through a wire e it is transmitted equally throughout a wire cuts a magnetic field f a current is induced in the wire the fluid pressure is applied to the surface g it cools down of an enclosed fluid a force is applied to a spring fixed h it sets up a magnetic field around at one end the wire i it changes to a liquid Word study: Verbs and related nouns Task 4: Each of the verbs in column A has a related noun ending in -er or -or in column B Complete the blanks You have studied these words in this and earlier units Use a dictionary to check any spellings which you are not certain about A Verbs For example: refrigerate B Nouns A Verbs B Nouns refrigerator condense generate evaporator conduct compress resist radiate charger 10 control Writing: Describing a process, 2: location Study this diagram It describes the refrigeration process 43 exchanger Figure 7.2: Refrigerant circulation diagram In Unit we learnt that when we write about a process, we have to: Sequence the stages Locate the stages Describe what happens at each stage Explain what happens at each stage For example: sequence location description explanation The refrigeration process This compresses the gas so that it heats up begins in the compressor In this unit we will study ways to locate the stages Task 5: Put these stages in the refrigeration process in the correct sequence with the help of the diagram above The first one has been done for you a The liquid enters the evaporator _ b The gas condenses back into a liquid _ c The vapour is sucked back into the compressor _ d The gas is compressed e The liquid turns into a vapour _ f The gas passes through the condenser _ g The liquid passes through a capillary tube _ h The high pressure is maintained _ There are two ways to locate a stage in a process Using a preposition + noun phrase For example: The liquid turns to vapour in the evaporator The gas cools down in the condenser Using a where-clause, a relative clause with where rather than which or who, to link a stage, its location and what happens there For example: 44 The warm gas passes through the condenser, where it heats the surroundings and cools down The refrigerant circulates around the fridge, where it undergoes changes in pressure and temperature Task 6: Complete each of these statements The gas passes through the compressor, where _ It passes through the condenser, where The liquid passes through a capillary tube, where The liquid enters the evaporator, where The cold vapor is sucked back into the compressor, where _ HOMEWORK FURTHER READING HOW TO REPAIR A REFRIGERATOR A refrigerator is one of the few appliances in your home that runs continuously, day or night, keeping your food cold If you consider how hard a refrigerator has to work, it is actually quite amazing that they break down so infrequently On the rare occasion your refrigerator does stop working, you may face a high repair bill and the expense of replacing all your lost food Have no fear! This article is here to tell you everything you need to know about repairing your refrigerator and freezer yourself You might be surprised to learn that repairs are actually quite easy, requiring only a little knowledge about the appliance and a little patience Let's get started with some basic information Refrigerators and freezers consist of two basic components: a condenser coil and an evaporator coil A liquid coolant is circulated through these coils by a compressor and a motor The refrigerant liquid is cooled in the condenser; it then flows to the evaporator At the evaporator, the air in the unit is cooled by contact with the liquidfilled coil The condenser of a refrigerator or freezer is the coil on the outside of the unit; the evaporator is the coil on the inside The coolant is circulated through the system by a compressor 45 Most refrigerators and freezers are frost-free In this type of unit, a heater is automatically turned on by a timer in order to melt the frost inside the unit Frost is melted by the heater at several different spots in the unit, starting with the coldest and most frosted areas When the frost is completely melted, the thermostat automatically switches to a cooling cycle in order to maintain the standard freezing temperature Because this process is automatic, frost does not build up inside the box The unit's compressor system, which forces the coolant through the coil system, is driven by a capacitor-type motor Other basic parts of the cooling/defrosting system include switches, thermostats, heaters, condensers, and fans A do-it-yourselfer can test and replace many of these refrigerator components However, there are exceptions, as explained later, that are best left to a professional repair person Caution: Before doing any work on a refrigerator or freezer, make sure it's unplugged After unplugging the unit, check to see if the motor/compressor has a capacitor; this component is located in a housing on the top of the motor Capacitors store electricity, even when the power to the unit is turned off Before you any work on a capacitor-type refrigerator or freezer, you must discharge the capacitor, or you could receive a severe shock 46 Yêu cầu đánh giá kết học tập chương Nội dung: + Về kiến thức: Trình bày nguyên lý làm việc tủ lạnh + Về kỹ năng: Biết cách sử dụng cấu trúc ngữ pháp đề cập + Năng lực tự chủ trách nhiệm: Tỉ mỉ, cẩn thận, xác, ngăn nắp công việc Phương pháp: + Về kiến thức: Được đánh giá hình thức kiểm tra viết, trắc nghiệm + Về kỹ năng: Ứng dụng kiến thức để đọc tài liệu liên quan + Năng lực tự chủ trách nhiệm: Tỉ mỉ, cẩn thận, xác, ngăn nắp cơng việc Điều kiện dự thi kết thúc môn học - Điều kiện để hồn thành mơ đun để dự thi kết thúc mơ đun: + Người học tham dự 70% thời gian học lý thuyết đầy đủ học tích hợp, học thực hành, thực tập + Điểm trung bình chung điểm kiểm tra đạt từ 5,0 điểm trở lên theo thang điểm 10; + Người học có giấy xác nhận khuyết tật theo quy định hiệu trưởng xem xét, định ưu tiên điều kiện dự thi sở sinh viên phải bảo đảm điều kiện điểm trung bình điểm kiểm tra + Số lần dự thi kết thúc mô đun theo quy định khoản Điều 13 Thông tư 09/2017/TT-BLĐTBXH, ngày 13 tháng năm 2017 - Điều kiện để công nhận, cấp chứng nhận đạt mô đun đào tạo: Người học công nhận cấp chứng nhận đạt mơ đun có điểm trung bình mơ đun theo thang điểm 10 đạt từ 4,0 trở lên 47 REFERENCE - Eric H Glendinning, Norman Glendinning, Oxford English for Electrical and Mechanical Engineering, Oxford University Press – 1995 Raymond Murphy, English grammars in use, New edition – 2005 Hooman Gohari, Air Conditioning and refrigeration repair made easy, 2009 edition -THE END - 48