Anh văn Chuyên ngành Nhiệt
English for thermal engineering

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Contents
1

Introduction to thermodynamics

2

Psychrometrics

3

The laws of thermodynamics

4

Reversed cycles and refrigeration air conditioning

5

Boiler and thermal power plant


Tài liệu tham khảo
1. Fundamentals of thermal-fluid science, Y. A. Çengel.
2. Fundamentals of thermodynamics (sixth edition),

Sonntag, Borgnakke and van Wylen.

3. Fundamentals of engineering thermodynamics (Fifth
edition), Michael J. Moran, Howard N. Shapiro.
4. English for thermal engineering, Đặng Thành Trung,
ĐHQG-HCM


Những trang Web tra từ chuẩn
1. Cambridge:
dictionary.cambridge.org/Default.asp?dict=CALD

2. Oxford:
www.oup.com/elt/catalogue/teachersites/oald7/?cc=global

3. Longman:
www.ldoceonline.com

4. dictionary.reference.com
5. www.merriam-webster.com
6. www.thefreedictionary.com
7. www.yourdictionary.com


Chapter 1: Introduction to thermodynamics

1.System
Definition:
A system is defined as a quantity of matter or a region in
space chosen for study.

The mass or region outside the system the surroundings.
The real or imaginary surface that separates the system
from its surroundings is called the boundary.

Classification
* Closed system (control mass)
* Open system (control volume)


Chapter 1: Introduction to thermodynamics

1.System
Classification
* Closed system (control mass):
- A fixed amount of mass, and no mass can cross its boundary.

- Energy, in the form of heat or work, can cross the boundary;
And the volume of a closed system does not have to be fixed.

- An isolated system which is not allowed mass and energy to
cross the boundary.


Chapter 1: Introduction to thermodynamics

1.System
Classification
* Open system (control volume):
Both mass and energy can cross the boundary of a control volume
It usually encloses a device that involves mass flow such as a

compressor, turbine, or nozzle.


Chapter 1: Introduction to thermodynamics
Absolute pressure

Atmospheric pressure

The force of a fluid acting on
unit area
p, [Pascal, Pa]

The pressure due to the force
by the atmosphere’s mass
pa = 760 mmHg (at sea level,
150C)

2.Pressure
Gage pressure
The difference between the
absolute pressure and the
atmospheric pressure, and
the difference is positive.
pg= p – pa > 0

Vacuum pressure
The difference between the
absolute pressure and the
atmospheric pressure, and
the difference is negative.

pv= p – pa < 0


Chapter 1: Introduction to thermodynamics
Pressure’s units:


Chapter 1: Introduction to thermodynamics

3.Temperature
Definition:

The measurement of the degree of hotness or
coolness is temperature
Temperature scales:
Celsius (0C), Fahrenheit (0F), Kelvin (K)

Conversion of temperature scales:
0C

= 5/9(0F-32); K = 0C + 273.15; 0F = 9/50C + 32


Chapter 1: Introduction to thermodynamics

3.Temperature
The Zeroth Law of thermodynamics:
Two bodies each in thermal equilibrium with a third
body will be in thermal equilibrium with each other.
:


Notice: The Zeroth Law of thermodynamics is a basis
for the validity of temperature measurement.


Chapter 1: Introduction to thermodynamics

3.Temperature
Thermometer:
A device is used to measure temperature, by using
materials that change in some way when they are
heated or cooled.

Thermometers.
(a) Liquid-in-glass; (b) Infrared - sensing ear
thermometer.


Chapter 1: Introduction to thermodynamics

4.Heat transfer
Definition
Heat is defined as the form of energy that is transferred between two
systems (or a system and its surroundings) by virtue of a temperature
difference (t  0).
Heat exists only as it crosses the boundary of a system and the
direction of heat transfer is from higher temperature to lower
temperature.

Units:

Calorie (Cal), Joule (J), Btu

Unit conversion:
1 Btu = 1055.056 J; 1 cal = 4.184 J; 1N.m = 1 J


Chapter 1: Introduction to thermodynamics

4.Heat transfer
Sensible Heat is an interaction energy related to changes in
temperature of a gas or object with no change in phase.
Latent Heat is defined as the energy absorbed by or released from

a substance during a phase change from a gas to a liquid or a solid.
Heat transferred to a system.
Heat transferred from a system.


Chapter 1: Introduction to thermodynamics

4.Heat transfer
Specific heat: the measure of the amount of heat required
to raise the temperature of a unit mass of a substance one
degree.

Cp is specific heat of the object at constant pressure.
Cv is specific heat of the object at constant volume.


Chapter 1: Introduction to thermodynamics


4.Heat transfer
Ideal-gas specific heats of various common gases:


Chapter 1: Introduction to thermodynamics

4.Heat transfer
Modes of heat transfer
Conduction:

Heat transferred between two bodies in direct contact.
Convection:
Heat transfer between a solid surface and an adjacent gas or liquid.

Thermal Radiation:
The energy emitted by matter in the form of electromagnetic waves
as a result of the changes in the electronic configurations of the
atoms or molecules.


Chapter 1: Introduction to thermodynamics

4.Heat transfer
Modes of heat transfer


Chapter 1: Introduction to thermodynamics

5. Work, W [J]:

Definition:
Work, like heat, is an energy interaction between a system
and its surroundings.
In other word, work is the energy transfer associated with
a force acting through a distance.
W > 0: Work transferred out of a system
W < 0: Work transferred in a system


Chapter 1: Introduction to thermodynamics

5. Work, W [J]:
Formula:
For a change in volume from V1 to V2, the work is obtained:


Vocabulary
Thermodynamics (θɜ:məudai'næmiks): Nhiệt động học
System (ˈsɪs.təm): Hệ nhiệt động
Boundary (ˈbaʊn.dər.i): Biên hệ NĐ Text
Surrounding (səˈraʊnd): Môi trường xung quanh
Pressure ('preʃə): Áp suất
Absolute (ˈæb.sə.luːt):Tuyệt đối
Absolute pressure (n): Áp suất tuyệt đối
Text
Vacuum ('vækjuːm) : Chân không
Vacuum pressure (n): Áp suất chân không
Text
Atmosphere (ˈæt.mə.sfɪə): Khí quyển.
Temperature (ˈtem.prə.tʃər): Nhiệt độ

Fluid (ˈfluː.ɪd): Chất lỏng
Conduction (kənˈdʌk.ʃən): Dẫn nhiệt
Convection (kənˈvek.ʃən): Đối lưu nhiệt
Radiation (ˌreɪ.diˈeɪ.ʃən): Bức xạ nhiệtText
Sensible (ˈsen.sə.bəl) heat: Nhiệt hiện
Latent (ˈleɪ.tənt) heat: Nhiệt ẩn


Passive

Text

Text
Text

Text




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