CHAPTER 1a: BASIC CONCEPTS OF THERMODYNAMICS

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CONTENTS
 Thermodynamics and Energy  Dimensions and Units  Systems and Properties  State, Processes and Cycles  Temperature  Pressure and Measuring Devices  Problem Solving Technique
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LESSON OBJECTIVES
At the end of the lesson, you should be able to:

Identify application of thermodynamics

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Define & differentiate between closed system and control volume (open system)
Differentiate between intensive and extensive properties

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What Is Thermodynamics?
Greek Words
Therme (heat) Dynamis (Power)

It is a science of energy.

Early description: Convert heat into power. Current Definition: The study of energy and energy transformations, including power generation, refrigeration and relationship among the properties of matter. Thermodynamics involve the conservation of energy principle.
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APPLICATION
 House-hold utensils:  Air-conditioner, heater, refrigerator  Humidifier, pressure cooker, water heater, shower, iron  Computer & TV  Engines:  Automotive, aircraft, rocket  Plant/ Factory  Refinery, power plants, nuclear power plant
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DIMENSIONS & UNITS

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SYSTEMS & CONTROL VOLUMES
Thermodynamic system (system)

quantity of matter or a region in space chosen for study.

Surroundings

the mass or region outside the system (external)

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SYSTEMS & CONTROL VOLUMES (cont’d)
Boundary

 the real or imaginary surface that separates the system
  from its surrounding contact surface shared by both the system & surroundings has zero thickness & can either contain any mass nor occupy volume in space.

fixed Boundary movable

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SYSTEMS & CONTROL VOLUMES (cont’d)
TYPES OF SYSTEM Closed System (control mass) No mass transfer across boundary Isolated System No mass or energy transfer Open System (control volume) Mass transfer across boundary