Thermodynamics is the science that deals with the relationship between energy, work, and heat in systems. It has four main laws: 1) The first law relates to the concept of internal energy. 2) The second law indicates the limit of converting heat to work and introduces the concept of entropy. 3) The third law defines the absolute zero of entropy. Thermodynamics has many applications, including all heat engines like cars and power plants, as well as refrigerators, air conditioners, heat pumps, compressors, and devices involving heat transfer such as heat exchangers. Key terms include the system, boundaries, and different types of systems such as closed, open, and isolated

1. Applied Thermodynamics
Unit – One
Prof – Yogesh S. Khairnar
Sanjeevan College of Engineering and Technology Institute, Panhala

2. Basic Definitions
Definition – Thermodynamics is the science that deals with
integration between energy (heat and work) and material systems.
OR
- Thermodynamics is an axiomatic science which deals the
relations among heat, work and properties of system which are in
equilibrium.
Basis is experimental observations written down as laws.
• 1st law of thermodynamics relents to concept of Internal
Energy.
• Zeroth law of thermodynamics deals with thermal equilibrium.
• 2nd law of thermodynamics indicates the limit of converting heat
into work and introduces the principal of increase of entropy.
• 3rd law of thermodynamics defines the absolute zero of entropy.
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Sanjeevan Engineering and Technology Institute, Panhala

3. Applications of Thermodynamics
1) All types of vehicles that we use, cars, motorcycles, trucks, ships, aeroplanes, and
many other types work on the basis of second law of thermodynamics and
Carnot Cycle. They may be using petrol engine or diesel engine, but the law
remains the same.
2) All the refrigerators, deep freezers, industrial refrigeration systems, all types of
air-conditioning systems, heat pumps, etc work on the basis of the second law of
thermodynamics.
3) All types of air and gas compressors, blowers, fans, run on various
thermodynamic cycles.
4) One of the important fields of thermodynamics is heat transfer, which relates to
transfer of heat between two media. The concept of heat transfer is used in wide
range of devices like heat exchangers, evaporators, condensers, radiators,
coolers, heaters, etc.
5) Thermodynamics also involves study of various types of power plants like
thermal power plants, nuclear power plants, hydroelectric power plants, power
plants based on renewable energy sources like solar, wind, geothermal, tides,
water waves etc,
6) Renewable energy is an important subject area of thermodynamics that involves
studying the feasibility of using different types of renewable energy sources for
domestic and commercial use.
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Sanjeevan Engineering and Technology Institute, Panhala

4. Important Terms in Thermodynamics
• System – A system is a finite quantity of matter or a prescribed region of space.
• Boundary – The actual or hypothetical envelope enclosing the system is the
boundary of the system
Types of system –
• Close System – If the boundary of the
system is impervious to the flow of the
matter. ( i.e. Only heat can cross the
boundary of the system)
• Open System – A system in which
matter flows into or out of the system
• Isolated System – System which
exchanges neither energy nor matter with
any other system
• Adiabatic System – A system thermally
insulated from its surroundings. It can
however, exchange work with the
surroundings.
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Sanjeevan Engineering and Technology Institute, Panhala

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Sanjeevan Engineering and Technology Institute, Panhala