1. Thermodynamics An Engineering Approach Yunus A. Çengel
Third Edition
Yunus A. Çengel
Michael A. Boles
WCB/McGraw-Hill
© The McGraw-Hill Companies, Inc.,1998

2. 1
CHAPTER
Basic Concepts of Thermodynamics

3. Applications of Thermodynamics
1-1
Applications of Thermodynamics
Power plants
The human body
Air-conditioning systems
Airplanes
Car radiators
Refrigeration systems

4. Crossing Closed-System Boundries
1-2
Crossing Closed-System Boundries
Energy, not mass, crosses closed-system boundries
(Fig. 1-13)

5. Closed System with Moving Boundry
1-3
Closed System with Moving Boundry

6. Crossing Control Volume Boundaries
1-4
Crossing Control Volume Boundaries
Mass and Energy Cross Control Volume Boundaries

7. System’s Internal Energy
1-5
System’s Internal Energy
System’s Internal Energy = Sum of Microscopic Energies
(Fig. 1-19)

8. Quasi-Equilibrium, Work-Producing Devices
1-6
Quasi-Equilibrium, Work-Producing Devices
Quasi-Equilibrium, Work-Producing Devices Deliver the Most Work
(Fig. 1-30)

9. Compressed Process P-V Diagram
1-7
Compressed Process P-V Diagram
(Fig. 1-31)

10. Absolute, Gage, and Vacuum Pressures
1-8
Absolute, Gage, and Vacuum Pressures
(Fig. 1-36)

11. 1-9
The Basic Manometer

12. Temperature Scales Comparison
1-10
Temperature Scales Comparison
(Fig. 1-48)

13. Many Ways to Supply the Same Energy
1-11
Many Ways to Supply the Same Energy
Ways to supply a room with energy equalling a 300-W electric resistance heater
(Fig. 1-52)

14. Bomb Calorimeter Used to Determine Energy Content of Food
1-12
Bomb Calorimeter Used to Determine Energy Content of Food
(Fig. 1-53)

15. 1-13
Chapter Summary
Thermodynamics is the science that primarily deals with energy.

16. 1-14
Chapter Summary
The first law of thermodynamics is simply an expression of the conservation of energy principle, and it asserts that energy is a thermodynamic property.
The second law of thermodynamics asserts that energy has quality as well as quantity, and actual processes occur in the direction of decreasing quality of energy.

17. 1-15
Chapter Summary
A system of fixed mass is called a closed system, or control mass, and a system that involves mass transfer across its boundaries is called an open system, or control volume.

18. 1-16
Chapter Summary
The mass-dependent properties of a system are called extensive properties and the others, intensive properties. Density is mass per unit volume, and specific volume is volume per unit mass.

19. 1-17
Chapter Summary
The sum of all forms of energy of a system is called total energy, which is considered to consist of internal, kinetic, and potential energies. Internal energy represents the molecular energy of a system and may exist in sensible, latent, chemical, and nuclear forms.

20. 1-18
Chapter Summary
A system is said to be in thermodynamic equilibrium if it maintains thermal, mechanical, phase, and chemical equilibrium.

21. 1-19
Chapter Summary
Any change from one state to another is called a process.
A process with identical end states is called a cycle.

22. 1-20
Chapter Summary
During a quasi-static or quasi-equilibrium process, the system remains practically in equilibrium at all times.

23. 1-21
Chapter Summary
The state of a simple, compressible system is completely specified by two independent, intensive properties.

24. 1-22
Chapter Summary
Force per unit area is called pressure, and its unit is the pascal. The absolute, gage, and vacuum pressures are related by

25. 1-23
Chapter Summary
Small to moderate pressure differences are measured by a manometer, and a differential fluid column of height h corresponds to a pressure difference of where  is the fluid density and g is the local gravitational acceleration.

26. 1-24
Chapter Summary
The atmospheric pressure is measured by a barometer and is determined from where h is the height of the liquid column above the free surface.

27. 1-25
Chapter Summary
The zeroth law of thermodynamics states that two bodies are in thermal equilibrium if both have the same temperature reading even if they are not in contact.

28. 1-26
Chapter Summary
The temperature scales used in the SI and the English system today are the Celsius scale and the Fahrenheit scale, respectively.

29. 1-27
Chapter Summary
The absolute temperature scale in the SI is the Kelvin scale, which is related to the Celsius scale by

30. 1-28
Chapter Summary
In the English system, the absolute temperature scale is the Rankine scale, which is related to the Fahrenheit scale by

31. 1-29
Chapter Summary
The magnitudes of each division of 1 K and 1 0C are identical, and so are the magnitude of each division of 1 R and 10F. Therefore, and

32. 1-30
Chapter Summary
An important application area of thermodynamics is the biological system. Most diets are based on the simple energy balance: the net energy gained by a person in the form of fat is equal to the difference between the energy intake from food and the energy expended by exercise.