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
của Hiệu trưởng trường Cao đẳng nghề Cần Thơ

Cần Thơ, năm 2021
(Lưu hành nội bộ)



TUYÊN BỐ BẢN QUYỀN
Tài liệu này thuộc loại sách giáo trình nên các nguồn thơng tin có thể được phép
dùng nguyên bản hoặc trích dùng cho các mục đích về đào tạo và tham khảo.
Mọi mục đích khác mang tính lệch lạc hoặc sử dụng với mục đích kinh doanh
thiếu lành mạnh sẽ bị nghiêm cấm.
LỜI GIỚI THIỆU
Trong chương trình đào tạo nghề Kỹ thuật máy lạnh và điều hòa khơng khí, tiếng
Anh chun ngành có một vị trí đặc biệt quan trọng, trong bối cảnh hội nhập và hợp
tác quốc tế thì tiếng Anh chun ngành cịn phục vụ trực tiếp cho việc học tập và
nghiên cứu của sinh viên về lĩnh vực điện lạnh.
Giáo trình ANH VĂNCHUYÊN NGÀNH được biên soạn dành cho sinh viên
ngành Vận hành sửa chữa thiết bị lạnh, được học tiếp sau khi đã học môn học Ngoại
ngữ (Tiếng Anh cơ bản) để đáp ứng nhu cầu học tập và nghiên cứu của sinh viên.
Giáo trình được biên soạn với thời lượng 45 giờ gồm có 7 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 này được biên soạn với sự tham khảo các tài liệu và sự đóng góp tận
tình của các đồng nghiệp trong bộ mơn. Tuy nhiên giáo trình khơng thể tránh khỏi
những thiếu sót. Rất mong sự đóng góp ý kiến của các đồng nghiệp, của các sinh viên
và các bạn đọc quan tâm đến giáo trình này.
Cần Thơ, ngày.......tháng ...... năm 2021
Tham gia biên soạn
1. Lê Thanh Tuyền
2. Trần Minh Khoa

1


MỤC LỤC
Trang
Lời giới thiệu
Unit 1: Engineering - what's it all about? ............................................................ 4
Unit 2: Engineering materials ............................................................................... 9
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


2


GIÁO TRÌNH MƠN HỌC
Tên mơn học: ANH VĂN CHUN NGÀNH
Mã mơn học: MH 20
Vị trí, tính chất, ý nghĩa và vai trị của mơn học:
- Vị trí: Mơn học Anh văn chuyên ngành là môn học áp dụng trong các khối đào tạo về
kỹ thuật cụ thể và thường được bố trí thực hiện sau khi học sinh đã học xong phần
tiếng Anh cơ bản;
- Tính chất: là mơn học bắt buộc.
- Vai trị: Ngoại ngữ ln quan trọng trong mọi lĩnh vực và tiếng Anh không chỉ giúp
cho người học có thể tìm hiểu chun sâu hơn về lĩnh vực của mình, mà cịn giúp
người học mở rộng cánh cửa cho con đường tương lai nghề nghiệp.
Mục tiêu môn học:
➢ Về kiến thức:
- Củng cố lại kiến thức và kỹ năng mà sinh viên đã được học ở học phần tiếng
Anh cơ bản
- Hiểu đựơc và mở rộng các cấu trúc ngữ pháp và từ vựng chuyên ngành Vận
hành sửa chữa thiết bị lạnh thông dụng, chú ý tới các yếu tố liên kết văn bản tiếng Anh
- Mở rộng đựợc vốn từ vựng về chuyên ngành Vận hành sửa chữa thiết bị lạnh.
➢ Về kỹ năng
- Phát triển các kỹ năng theo một hệ thống các chủ điểm gắn liền với các hoạt
động chuyên ngành về Vận hành sửa chữa thiết bị lạnh, đặc biệt phát triển kỹ năng
đọc, dịch, hiểu.
- Xây dựng và rèn luyện các kỹ năng học tập ngoại ngữ đồng thời hình thành và
phát triển khả năng độc lập suy nghĩ và sáng tạo trong giao tiếp bằng tiếng Anh cho
sinh viên
- Phát triển kỹ năng làm việc theo cặp, theo nhóm
- Định hướng cho sinh viên tầm quan trọng của tiếng Anh trong cuộc sống và

trong công việc tương lai
➢ Về năng lực tự chủ và trách nhiệm
- Rèn luyện tính cẩn thận, chính xác trong q trình làm việc
- Rèn luyện tính khoa học, tính sáng tạo trong giao tiếp.
Nội dung mơn học:

3


UNIT 1: ENGINEERING – WHAT’S IT ALL ABOUT ?
Mã bài: MH 20- 01
Giới thiệu:
Ngành kỹ thuật vơ cùng rộng, nó bao gồm một loạt các lĩnh vực kỹ thuật đặc thù,
mỗi lĩnh vực nhấn mạnh đến những lĩnh vực công nghệ và những kiểu ứng dụng riêng.
Hiện nay có rất nhiều ngành nghề liên quan đến kỹ thuật và những người hành nghề kỹ
thuật được gọi là kỹ sư
Mục tiêu:
Sau khi học xong bài này người học có khả năng:
- Trình bày đúng các ngành kỹ thuật chính.
- Xác định mục đích trước khi đọc.
- Sử dụng được 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

1_________

3_______ Automobile 4__________

Electrical

Heating
and
ventilating

Electricity
5_________

7_________

Electrical
installation

2_________


6_________

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.

4


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 3. 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.
5


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:
1 Mechanical engineering deals with machines.
2 Mechanical engineers deal with machines.
3 Mechanical engineering is concerned with machines
4 Mechanical engineers are concerned with machines.
5 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
1
marine

a air-conditioning
2
aeronautical
b roads and bridges
3
heating and ventilating
c body scanners
4
electricity generating
d cables and switchgear
5
automobile
e communications and equipment
6
civil
f ships
7
electronic
g planes
8
electrical installation
h cars and trucks
9
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 2________________with machinery of all kinds.
This branch of engineering includes 3________________, automobile, aeronautical,
and heating and ventilating. The first three are concerned with transport:

6


4

___________, cars and planes. The last 5 ________________ with air- conditioning,
refrigeration, etc.
Electrical engineering deals with 6______________from generation to use.
Electricity generating is concerned with to 7_______________stations. Electrical
installation deals 8______________ cables, switchgear, and connecting electrical
equipment.
Two branches of engineering include both mechanical and 9_________________
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 về đánh giá kết quả học tập chương 1
Nội dung:
+ Về kiến thức: Nhận biết các ngành kỹ thuật thông qua các công việc đặc trưng
7


+ Về kỹ năng: Biết cách sử dụng các cấu trúc ngữ pháp đã được đề cập trong bài
+ Năng lực tự chủ và trách nhiệm: Tỉ mỉ, cẩn thận, chính xác, ngăn nắp trong cơng
việc.
Phương pháp:
+ Về kiến thức: Được đánh giá bằng hình thức kiểm tra viết, trắc nghiệm.
+ Về kỹ năng: Ứng dụng được kiến thức để đọc các tài liệu liên quan.
+ Năng lực tự chủ và trách nhiệm: Tỉ mỉ, cẩn thận, chính xác, ngăn nắp trong công
việc.

8



UNIT 2: ENGINEERING MATERIALS
Mã bài: MH 20- 02
Giới thiệu:
Vật liệu kỹ thuật theo cách hiểu phổ biến nhất là những vật liệu mà con người
dùng để chế tạo ra các máy móc, thiết bị, dụng cụ, v.v… trong các ngành công nghiệp,
nông nghiệp, giao thông vận tải, trong xây dựng các cơng trình, nhà cửa hay thay thế
các bộ phận cơ thể con người hoặc để thể hiện các ý đồ nghệ thuật. Hiện nay có rất
nhiều loại vật liệu được chế tạo nhằm phục vụ nhu cầu ngày càng cao của con người
bên cạnh các loại vật liệu truyền thống.
Mục tiêu:
- Trình bày được các loại vật liệu dùng trong kỹ thuật .
- Áp dụng được cách đọc scanning.
- Trình bày được cách định nghĩa vật liệu, thêm thơng tin để làm rõ tính chất
vật liệu .
Nội dung:

Tuning - in
Task 1: List the materials you know which are used in engineering. Combine your list
with the others in your group and classify the materials as metals,
thermoplastics, etc.
Reading: Scanning tables
In engineering, it is important to practice reading tables, charts, diagrams, and
graphs because so much information is presented in these ways. We will start in this
unit with a table.
Scanning is the best strategy for finding information in a table. With scanning, you
know before you read what sort of information you are searching for. To scan a table,
you move your eyes up and down the columns until you find the word or words you
want. To scan quickly, you must learn to ignore any information which will not help

you with your task.
Task 2: Scan the table which follows to find a material which is:
1 soft
6 conductive and malleable
2 ductile
7 durable and hard
3 malleable
8 stiff and brittle
9


4 tough
5 scratch-resistant
Materials
Metals

9 ductile and corrosion-resistant
10 heat-resistant and chemical-resistant
Properties

Uses

Light, soft, ductile, highly
conductive, corrosion-resistant.
Very malleable, tough and
ductile, highly conductive,
corrosion-resistant.
Very corrosion-resistant. Casts
well, easily machined. Can be
work

hardened.
Good
conductor.
High strength, ductile, tough,
fairly malleable. Cannot be
hardened and tempered. Low
cost. Poor corrosion resistance.
Hardest of the carbon steels but
less ductile and malleable. Can
be hardened and tempered.

Aircraft, engine components,
foil, cooking utensils

High impact strength and
ABS (Acrylonitrile
toughness,
scratch-resistant,
Butadien Styrene)
light and durable.
Stiff, hard, very durable, clear,
Acrylic
can be polished easily. Can be
formed easily.
Hard, tough, wear-resistant,
Nylon
self- lubricating.
Thermosetting plastics
High strength when reinforced,
Epoxy resin

good chemical and wear
resistance.
Stiff, hard, very durable, clear,
Polyester resin
can be polished easily. Can be
formed easily.
Stiff, hard, strong, brittle, heatUrea formaldehyde resistant, and a good electrical
insulator.

Safety
helmets,
car
components,
telephones,
kitchenware.

Aluminium
Copper

Brass
(65%
copper, 35% zinc)
Mild steel (iron
with 0.15% to
0.3% carbon)
High carbon steel
(iron with 0.7% to
1.4% carbon)
Thermoplastics


Task 3: Scan the table to find:
1 A metal used to make aircraft.
2 Plastics used for adhesives.
3 Steel which can be hardened.
4 An alloy suitable for castings.
5 A plastic with very low friction.
6 A material suitable for safety helmets.
10

Electric wiring, PCBs, tubing

Valves, taps casting, ship,
fittings, electrical contacts

General purpose

Cutting tools such as drills,
files, saws.

Aircraft canopies,
double glazing

baths,

Bearings, gears, casings for
power tools
Adhesives, encapsulation of
electronic components
Moulding,
bodies


boat

and

car

Electrical fittings, adhesives


7 A metal suitable for a salt-water environment.
8 A metal for general construction use but which should be protected from
corrosion.
9 A plastic for car bodies.
10 The metal used for the conductors in printed circuit boards.
Language study: Making definitions
Study these facts from the table about aluminum:
1 Aluminum is a light metal.
2 Aluminum is used to make aircraft.
We can link these facts to make a definition of aluminum.
1+2 Aluminum is a light metal which is used to make aircraft.
Task 4: Use the table on the previous page to make definitions of each of the materials
in column A. Choose the correct information in columns B and C to describe
the materials in column A.
A
1 An alloy
2 A thermoplastic
3 Mild steel
4 A conductor
5 An insulator

6 High carbon steel
7 Brass
8 A thermosetting plastic

B

a metal
a material
an alloy

C
allows heat or current to flow easily
remains rigid at high temperatures
does not allow heat or current to flow easily
contains iron and 0.7% to 1.4% carbon
becomes plastic when heated
contains iron and 0.15% to 0.3% carbon
formed by mixing other metals or elements
consists of copper and zinc

Writing: Adding information to a text
Study this text about aluminum.
Aluminum is used to make aircraft, engine components, and many items for the
kitchen.
We can add extra information to the text like this:
Aluminum, which is light, soft, and ductile, is used to make aircraft, engine
components - for example, cylinder heads - and many items for the kitchen, such
as pots.
Note that the extra information is marked with commas or dashes:
, which...

-for example..., such as ...,
Task 5: Add this extra information to the following text about plastics.
1. Plastics can be moulded into plates, car components, and medical aids.
2. Thermoplastics soften when heated again and again.
3. Thermosetting plastics set hard and do not alter if heated again.
4. ABS is used for safety helmets.
5. Nylon is self-lubricating.
6. Nylon is used for motorized drives in cameras.
7. Acrylic is a clear thermoplastic.
8. Acrylic is used for aircraft canopies and double glazing.
9. Polyester resin is used for boat and car bodies.
10. Polyester resin is hard and has good chemical and heat resistance.

11


Plastics are synthetic materials. They can be softened and moulded into useful
articles. They have many applications in engineering. There are two types of plastics:
thermoplastics and thermosetting plastics.
ABS is a thermoplastic which is tough and durable. Because it has high impact
strength, it has applications where sudden loads may occur.
Nylon is a hard, tough thermoplastic. It is used where silent, low-friction operation
is required.
Acrylic can be formed in several ways. It is hard, durable, and has many uses.
Polyester resin is a thermosetting plastic used for castings. It has a number of useful
properties.
HOMEWORK
FURTHER READING
Metals
Metals are the most commonly used class of engineering material. Metal alloys are

especially common, and they are formed by combining a metal with one or more other
metallic and/or non-metallic materials. The combination usually occurs through a
process of melting, mixing, and cooling. The goal of alloying is to improve the
properties of the base material in some desirable way.
Metal alloy compositions are described in terms of the percentages of the various
elements in the alloy, where the percentages are measured by weight.
Ferrous Alloys
Ferrous alloys have iron as the base element. These alloys and include steels and
cast irons. Ferrous alloys are the most common metal alloys in use due to the
abundance of iron, ease of production, and high versatility of the material. The biggest
disadvantage of many ferrous alloys is low corrosion resistance.
Carbon is an important alloying element in all ferrous alloys. In general, higher
levels of carbon increase strength and hardness, and decrease ductility and weldability.
Carbon Steel
Carbon steels are basically just mixtures of iron and carbon. They may contain
small amounts of other elements, but carbon is the primary alloying ingredient. The
effect of adding carbon is an increase in strength and hardness.
Most carbon steels are plain carbon steels, of which there are several types.
Low-Carbon Steel
Low-carbon steel has less than about 0.30% carbon. It is characterized by low
strength but high ductility. Some strengthening can be achieved through cold working,
but it does not respond well to heat treatment. Low-carbon steel is very weldable and
is inexpensive to produce. Common uses for low-carbon steel include wire, structural
shapes, machine parts, and sheet metal.
Medium-Carbon Steel
Medium-carbon steel contains between about 0.30% to 0.70% carbon. It can be
heat treated to increase strength, especially with the higher carbon contents. Mediumcarbon steel is frequently used for axles, gears, shafts, and machine parts.
High-Carbon Steel
High-carbon steel contains between about 0.70% to 1.40% carbon. It has high
strength but low ductility. Common uses include drills, cutting tools, knives, and

springs.

12


Yêu cầu về đánh giá kết quả học tập chương 2
Nội dung:
+ Về kiến thức: Nhận biết các vật liệu kỹ thuật thơng qua các tính chất đặc trưng
+ Về kỹ năng: Biết cách sử dụng các cấu trúc ngữ pháp đã được đề cập trong bài
+ Năng lực tự chủ và trách nhiệm: Tỉ mỉ, cẩn thận, chính xác, ngăn nắp trong công
việc.
Phương pháp:
+ Về kiến thức: Được đánh giá bằng hình thức kiểm tra viết, trắc nghiệm.
+ Về kỹ năng: Ứng dụng được kiến thức để đọc các tài liệu liên quan.
+ Năng lực tự chủ và trách nhiệm: Tỉ mỉ, cẩn thận, chính xác, ngăn nắp trong công
việc.

13


UNIT 3: SAFETY AT WORK
Mã bài: MH 20- 03
Giới thiệu:
An tồn lao động là giải pháp phịng, chống tác động của các yếu tố nguy hiểm
nhằm bảo đảm không xảy ra thương tật, tử vong đối với con người trong q trình lao
động. Nói cách khác an tồn lao động chính là giải pháp để khơng xảy ra tai nạn trong
q trình lao động. An tồn lao động là bắt buộc khi tham gia lao động. Điều này được
quy định trong luật vì thế thực hiện các biện pháp an tồn lao động là điều kiện bắt
buộc trong q trình làm việc. Lợi ích thứ 2 mà an tồn vệ sinh lao động đem đến đó là
đảm bảo được quyền lợi và nghĩa vụ của cả người lao động lẫn người lao động.

Mục tiêu:
- Trình bày được các quy tắc an toàn khi làm việc ở phân xưởng.
- Sử dụng được mệnh đề thời gian.
- Trình bày được cách thiết lập các quy tắc an toàn khi làm việc ở phân
xưởng.
Nội dung:

Figure 3.1: Electric welding

Tuning - in
Task 1: What do these warning labels on chemicals mean? Match each label to the
correct warning.
a Highly flammable
d Corrosive
b Harmful
e Oxidizing
c Explosive
f Toxic

14


Figure 3.2: warning labels

Task 2: List some of the potential dangers in your laboratory, workshop, or place of
work. How is the risk of these hazards reduced?
Task 3: Study the safety instructions from a workshop below, and then answer these
questions.
a Who are the instructions for?
b Who wrote them?

c What was the writer's purpose?
1 Wear protective clothing at all times.
2 Always wear eye protection when operating lathes, cutters, and
grinders and ensure the guard is in place.
3 Keep your workplace tidy.
4 The areas between benches and around machines must be kept clear.
5 Tools should be put away when not in use and any breakages and
losses reported.
6 Machines should be cleaned after use.
Reading Understanding the writer's purpose
Knowing what the writer's purpose is, who the writer is, and who the intended
readers are can help us to understand a text. The safety instructions in Task 3 are
clearly intended to encourage employees to be safety conscious and reduce the risk of
accidents. The writer is perhaps a supervisor or the company safety officer, and the
intended readers are machine operatives. Knowing these things can help us to work out
the meaning of any part of the text we may not understand.
Task 4: Study the company document on safety on the next page, and then answer
these questions.
1 Who is this document for?
a machine operatives
b managers
c all employees
d injured employees
2 Who wrote this document?
15


a trade union representative
b technician
c manager

d medical staff
3 What is the writer's intention?
a to prevent accidents
b to ensure speedy help for injured employees
c to protect the company
d to warn about dangers
Accident investigation
Whenever an accident occurs that results in an injury (medical case), damage of
equipment and material, or both, prompt accident investigation by the immediate
manager is required. A written preliminary investigation will be completed by the
end of the particular shift or business day on which the accident occurred.
In no event should there be a delay of more than 24 hours. Failure to comply with
this requirement may subject the immediate manager to disciplinary action up to and
including discharge.
Without adequate accident investigation data, the Company may be subjected to
costs, claims, and legal action for which it has no defence.
As a minimum, the preliminary accident investigation report will include the
following:
1 Name, occupation, and sex of injured worker.
2 Place and date / time of accident.
3 Description of how the accident happened.
4 Immediate causes of the accident -unsafe acts and unsafe conditions.
5 Contributing causes - manager safety performance, level of worker training,
inadequate job procedure, poor protective maintenance, etc.
6 Witness(es) - name and department.
7 Corrective action taken- when.
The employee who was injured and any employee(s) who witnessed the incident
should be separately interviewed as soon as possible. A copy of the report must be
submitted to the Manager - Human Resources for review. Another copy of the report
is to be retained for a period of not less than the injured employee's length of

employment plus five (5) years.
Task 5: Study this brief report of an accident. In which points does it not meet
company policy on reporting accidents?

16


Figure 3.3: report of an accident

Language study: Making safety rules
What are the differences in meaning, if any, between these statements?
1 Wear protective clothing.
2 Always wear protective clothing.
3 Protective clothing must be worn.
We can make safety rules in these ways:
1 Using an imperative.
Wear protective clothing.
Do not wear loose-fitting clothing.
2 Always / never are used to emphasize that the rule holds in all cases.
Always wear protective clothing.
Never wear loose-fitting clothing.
3 We can use a modal verb for emphasis
Protective clothing must be worn.
Protective clothing should be worn.
Task 6: Study this list of unsafe environmental conditions (hazards). Write safety rules
to limit these hazards using the methods given above. For example:
inadequate lighting
Lighting must be adequate. or
Lighting should be adequate.
1. uneven floors

2. unguarded machinery
3. untidy workbenches
4. untidy workplaces
5. badly maintained machinery
6. carelessly stored dangerous materials
7. inadequate ventilation
8. damaged tools and equipment
9. machinery in poor condition
10. equipment used improperly
11. equipment operated by untrained personnel
12. apprentices working without supervision

17


Writing: Ways of linking ideas
To make our writing effective, we have to make sure our readers can follow our
ideas. We learnt how to mark reasons, results, and contrasts in our writing.
What are the links between these ideas? What words can we use to mark the links?
1 The accident happened.
2 The operator's carelessness.
3 The supervisor was not present.
Sentence 2 is a reason for sentence 1. Sentence 3 is an additional reason. We can
mark the links between them like this:
The accident happened because of the operator's carelessness. In addition /
moreover, the supervisor was not present.
We use because of to introduce a reason which is a noun or noun phrase. We use in
addition or moreover to introduce an additional reason.
What are the links between these ideas? What words can we use to mark the links?
4 Suitable protection should be worn.

5 Safety helmets should be used where there is a danger of falling objects.
Sentence 5 is an example to illustrate sentence 4. We can mark this in this way:
Suitable protection should be worn. For example / For instance, safety helmets
should be used where there is a danger of falling objects.
Task 7: Show the links between these sets of ideas using appropriate linking words
below.
Because / since / as / so / therefore / but / because of / In addition / moreover / for
example / for instance
1 Many accidents happen.
Workers' carelessness.
2 Education can reduce accidents.
It is important that all workers receive training in basic safety.
3 Eye injuries can be serious.
Goggles must be worn for grinding and cutting.
4 Safety gloves provide protection for the hands.
They prevent burns.
They reduce the danger of cuts.
5 Safety shoes protect the feet against falling objects.
They prevent the feet getting caught in machinery.
6 Respirators should be worn in dusty conditions.
Dust can damage the lungs.
7 Safety gear exists for every danger.
Each year people are injured.
They refuse or forget to wear the right gear.

HOMEWORK
FURTHER READING
Why Workplace Safety Is Important

18



Safety training benefits workers and companies alike.
If someone were to ask you why safety is important, how would you respond? You
may "know" that it's important to keep safety in mind as we go about your daily
activities, but how would you explain the reasons why this is the case. Here are some
things to think about.
Why Safety Is Important in the Workplace
Companies that employ workers have an interest in keeping the workplace safe.
Job-related injuries are something that responsible employers avoid. They take the
time and use company resources to make sure that the people who come to work each
day are safe.
They may offer on-the-job safety training or have safety procedures included in
their company policies. In some workplaces, a person or a group of workers are
designated as the company safety team. These people are responsible for ensuring that
the premises are in compliance with safety regulations set out by law.
Not only does this make good sense from a moral standpoint, but it also
makes good financial sense. If a worker is injured on the job, it costs the company in
terms of lost man hours, increased insurance costs, workers' compensation premiums,
and legal costs.
Productivity is lost when other workers have to stop doing their job to deal with
the situation. Even after the injured worker has been sent home or taken to hospital,
other employees may be distracted or need to take time off from work in the aftermath
of the incident.
Yêu cầu về đánh giá kết quả học tập chương 3
Nội dung:
+ Về kiến thức: Nhận biết các biểu tượng cảnh báo, thiết lập và tuân thủ các qui tắc an
toàn trong lao động
+ Về kỹ năng: Biết cách sử dụng các cấu trúc ngữ pháp đã được đề cập trong bài
+ Năng lực tự chủ và trách nhiệm: Tỉ mỉ, cẩn thận, chính xác, ngăn nắp trong cơng

việc.
Phương pháp:
+ Về kiến thức: Được đánh giá bằng hình thức kiểm tra viết, trắc nghiệm.
+ Về kỹ năng: Ứng dụng được kiến thức để đọc các tài liệu liên quan.
+ Năng lực tự chủ và trách nhiệm: Tỉ mỉ, cẩn thận, chính xác, ngăn nắp trong cơng
việc.

19


UNIT 4: FUNDAMENTALS OF REFRIGERATION
Mã bài: MH 20- 04
Giới thiệu:
Sự làm lạnh nói chung được coi là quy trình giải nhiệt từ khơng gian hoặc vật liệu
và duy trì khơng gian hoặc vật liệu đó ở nhiệt độ thấp hơn mơi trường. Nói chung,
mạch (hệ thống) làm lạnh kín được dùng để lấy nhiệt bên trong không gian hoặc vật
liệu và đưa đến nơi khác. Khi hệ thống tiếp tục vận hành, nhiệt được lấy ra càng
nhiều, không gian hoặc vật liệu tiếp tục được làm lạnh. Quy trình có thể được dùng để
làm lạnh các loại thực phẩm, rau xanh, trái cây, hoặc các loại sản phẩm khác, để có
thể bảo quản chúng trong thời gian dài…
Mục tiêu:
- Trình bày được các kiến thức cơ bản về sự làm lạnh, nhiệt và sự truyền
nhiệt, đơn vị của nhiệt.
- Cách sử dụng thì hiện tại đơn ở thể chủ động và bị động.
Nội dung
Task 1
READING COMPREHENSION
Fundamentals of refrigeration
Refrigeration is the process of removing heat from an area or a substance and is
usually done by an artificial means of lowering the temperature, such as the use of ice

or mechanical refrigeration.
Nature of Heat
Heat is a form of energy contained to some extent in every substance on earth.
All known elements are made up of very small particles, known as atoms, which, when
joined together, form molecules. These molecules are particular to the form they
represent. For example, carbon and hydrogen in certain combinations form sugar and
in others form alcohol.

Figure 4.1: States of water

When heat is added to a substance, the rate of molecular motion increases, causing
20


the substance to change from a solid to a liquid, and then to a gas (vapor). For
example, in a cube of ice, molecular motion is slow, but as heat is added, molecular
activity increases, changing the solid "ice" to a liquid "water" (Fig. 6-1).
Units of Heat
The amount of heat added to, or subtracted from, a body can best be measured by
the rise or fall in temperature of a known weight of a substance. The standard unit of
heat measure is the amount of heat necessary to raise the temperature of 1 pound of
water 1°F at sea level when the water temperature is between 32°F and 212°F.
Conversely, it is also the amount of heat that must be extracted to lower by 1oF the
temperature of a pound of water between the same temperature limits. This unit of heat
is called a British thermal unit (Btu). The Btu's equivalent in the metric system is the
calorie, which is the amount of heat required to raise one gram of water 1 o Celsius.

Figure 4.2: Unit of heat

UNDERSTANDING THE PASSAGE

Task 2. Answer the following questions
1. What is refrigeration?
…………………………………………………………………………………
…………………………………………………………………………………
2. What is heat?
…………………………………………………………………………………
…………………………………………………………………………………
3. What happens when heat is added to a substance?
…………………………………………………………………………………
…………………………………………………………………………………
4. Why does the substance change from a solid to a liquid?
21


…………………………………………………………………………………
…………………………………………………………………………………
5. What is the unit of heat called?
…………………………………………………………………………………
…………………………………………………………………………………
Task 3. Are these sentences true or false? Correct the false sentences.
1. Refrigeration is the process of adding heat from an area or a substance.
…………………………………………………………………………………
….………………………………………………………………………………
2. Carbon and hydrogen in certain combinations form sugar and in
others form alcohol.
…………………………………………………………………………………
….………………………………………………………………………………
3. When heat is remove from a substance, the rate of molecular motion
increases.
…………………………………………………………………………………

….………………………………………………………………………………
4. The standard unit of heat measure is the amount of heat necessary to
raise the temperature.
…………………………………………………………………………………
….………………………………………………………………………………
5. The calorie is the amount of heat required to fall one gram of water 1
Celsius.
…………………………………………………………………………………
….………………………………………………………………………………

o

Task 4. Choose the best answer
1.
Refrigeration is usually done by an artificial means of ............. the
temperature.
A.
adding
B. lowering
C. removing
D. causing
2. All known elements are ................. up of very small particles
A.
adding
B. done
C. certain
D. made
3. Carbon and hydrogen in certain combinations ................. sugar.
A.
form

B. metric
C. measured
D. causing
4. A body can best be .................by the rise or fall in temperature .
A.
adding
B. lowering
C. measured
D. metric
5. The Btu's equivalent in the .................. system is the calorie.
A.
rise
B. metric C. removing
D. certain
FORM
[VERB] + s/es in third person
Use the Simple Present to express the idea that an action is repeated or
usual. The action can be a habit, a hobby, a daily event, a scheduled event or
something that often happens. It can also be something a person often forgets
or usually does not do.
Examples:
- Heat is a form of energy contained to some extent in every substance
on earth.

22


- REFRIGERATION is the process of removing heat from an area or a
substance
ACTIVE / PASSIVE

Examples:
- Molecules are in a constant state of motion.
ACTIVE
- All known elements are made up of very small particles
PASSIVE
PRACTICE
Exercise 1. Rearrange these words to make the sentences
1. is /Refrigeration / the /of /heat./ process/ removing
…………………………………………………………………………………
…..……………………………………………………………………………
2. is /Heat/ a / energy. / form/ of
…………………………………………………………………………………
…..……………………………………………………………………………
3. molecular / rate / The /of / increases./ motion
…………………………………………………………………………………
…..……………………………………………………………………………
4. best / body/ A/ can /be /by / measured /the /in /rise/ fall /temperature ./ or
…………………………………………………………………………………
…..……………………………………………………………………………
5. unit /heat /This /of /is /a /thermal /called / unit./ British
………………………………………………………………………………
…..……………………………………………………………………………
Exercise 2. Match the words in A to the appropriate phrase in B
A

B

1. refrigeration
2. Btu


a. a form of energy expands and fills whatever
space
b. the amount of heat necessary to raise the
temperature

3. Heat

c. British thermal unit

4. substances

d. the process of removing heat from an area or a
substance

5. The standard unit of
heat measure

e. solid, liquid, and gas

Exercise 3. Put a word to complete the passage
a glass tube ;

scales ;

a thermometer; the controls ;

these liquids

Measurement of Heat
The usual means of measuring temperature is …………. It measures the

degree or intensity of heat and usually consists of ………. with a bulb at the
lower portion of the tube that contains mercury, colored alcohol, or a volatile
liquid. The nature of ....................................... causes them to rise or fall
uniformly in
23