1. Introduction To Thermodynamics
ERT 206/4 Thermodynamics
CHAPTER 1
Introduction To Thermodynamics
Miss. Rahimah Bt. Othman

2. COURSE OUTCOME 1 CO1) Chapter 1: Introduction to Thermodynamics
Identify and analyze scope, dimensions and units, measure of amount or size, force, temperature, pressure, work, energy and heat.
2. Chapter 2: The First Law and Other Basic Concepts
3. Chapter 3: Volumetric properties of pure fluids
4. Chapter 4: Heat effects
5. Chapter 5: Second law of thermodynamics
6. Chapter 6: Thermodynamics properties of fluids

3. THERMODYNAMICS: Definition
(from the Greek θέρμη therme, meaning "heat“ and δύναμις, dynamis, meaning "power")
- is the study of energy conversion between heat and mechanical work,
and subsequently the macroscopic variables such as temperature, volume
and pressure.
THERMO =
HEAT AND TEMPERATURE
DYNAMICS =
MOTION

4. THERMODYNAMICS: Definition
* Initially, thermodynamics is the study of the flow of heat to
produce mechanical energy that could be used for locomotive;
- after that is used for steam engines, turbines, pumps, air
conditioners etc.
* Because such equipment also used in chemical/ bioprocess
plant, it is also important for those engineers to learn the
fundamental of such equipment.

5. THERMODYNAMICS: Example
The production of chemicals, polymers, pharmaceuticals and other
biological materials, and oil and gas processing, all involve chemical or
biochemical reaction that produce a mixture of reaction product.
(e.g:Production of acetic acid from ethanol using Acetobacter aceti bacteria)
These must be separated from the mixture and purified to result in
product of societal, commercial, or medicinal value.
These is the area where thermodynamics plays a central role in
bioprocess eng.
Separation processes, e.g. distillation are designed based on information
from thermodynamics

7. Measures of amount or size
Thermodynamics
Dimensions and Units
Measures of amount or size
Force
Temperature
Pressure
Work
Energy
Heat

8. Measures of amount or size
Thermodynamics
Dimensions and Units
Measures of amount or size
Force
Temperature
Pressure
Work
Energy
Heat

9. Dimensions and Units
Dimension is recognize through our sensory perceptions and not
definable without the definition of arbitrary scales of measure,
divided into specific units of size.
The units have been set by international agreement, and are
codified as the International System of Units (SI).
Note: See Table 1.1 for Prefixes (eg: deca, hecto, kilo, etc.) of SI
units. (eg: 1 cm = 10-2 m, 1 kg = 103 g)

10. Measures of amount or size
Thermodynamics
Dimensions and Units
Measures of amount or size
Force
Temperature
Pressure
Work
Energy
Heat

11. Measures of amount or size
Three measures of amount or size are in common use:
Mass, m ; Number of moles, n ; Total volume, Vt
Mass, m divided by the molar mass M (molecular weight) to yield
number of moles;
Total volume, divided by the mass or number of moles of the system to yield specific or molar volume. or
Specific volume: or
Molar volume: or

12. Measures of amount or size
Thermodynamics
Dimensions and Units
Measures of amount or size
Force
Temperature
Pressure
Work
Energy
Heat

13. Metric engineering system units
Force
SI unit
Metric engineering system units
Newton (N)
Kilogram force (kgf)
F = ma
* Note : The kilogram force is equivalent to N

14. Force Example 1.1 With a = g, Newton’s law is : F = mg. Hence;
An astronaut weighs 730 N in Houston, Texas, where the local acceleration of gravity is g = ms-2. What are the astronaut’s mass and weight on the moon, where g = 1.67 ms-2.
Solution
With a = g, Newton’s law is : F = mg. Hence;
Because the newton N has the unit kg m s-2,
This mass of the astronaut is independent f location, but weight depends on the local acceleration of gravity. Thus on the moon the astronaut’s weight is;

15. Measures of amount or size
Thermodynamics
Dimensions and Units
Measures of amount or size
Force
Temperature
Pressure
Work
Energy
Heat

16. Temperature
Temperature is commonly measured with liquid-in-glass thermometers,
wherein the liquid expands when heated.

17. Measures of amount or size
Thermodynamics
Dimensions and Units
Measures of amount or size
Force
Temperature
Pressure
Work
Energy
Heat

18. Metric engineering system units
Pressure
The pressure P exerted by a fluid on a surface is defined as the normal
force exerted by the fluid per unit area of the surface.
SI unit
Metric engineering system units
Pascal (Pa)
Kilogram force per square centimeter (kgf cm-2)
The primary standard for pressure measurement is the dead-weight
gauge in which a known force is balanced by a fluid pressure acting
on a known area.

19. Force Example 1.2
A dead-weight gauge with a 1 cm diameter piston is used to measure pressures very accurately. In a particular instance a mass of 6.14 kg (including piston and pan) brings it into balance. If the local acceleration of gravity is 8.82 ms-2, what is the gauge pressure being measured? If the barometric pressure is 748 Torr, what is the absolute pressure?
Solution
The force exerted by gravity on the piston, pan and weights is
The absolute pressure is therefore;

20. Force Example 1.3
At 27oC ( K) the reading on a manometer filled with mercury is 60.5 cm. The local acceleration of gravity is ms-2. To what pressure does this height of mercury correspond?
Solution
Recall the equation in the preceding text, P = hρg. At 27 oC ( K) the density of mercury is g cm-3. Then,

21. Measures of amount or size
Thermodynamics
Dimensions and Units
Measures of amount or size
Force
Temperature
Pressure
Work
Energy
Heat

22. Work
Work, W is performed whenever a force acts through a distance.
* Note: The minus sign ‘-’ the volume change is positive, and the minus sign is required to make the work negative.

23. Measures of amount or size
Thermodynamics
Dimensions and Units
Measures of amount or size
Force
Temperature
Pressure
Work
Energy
Heat

24. THANK YOU

25. TUTORIAL 1 - QUESTIONS Problems : 1.3, 1.4, 1.11, 1.14, 1.22
Reference Book:
Smith, J.M., Van Ness, H.C. and Abbort, M.M., Introduction to Chemical Engineering Thermodynamics, Seventh Edition, McGraw-Hill, 2005.