GURPREET Eme Presentation 97-2003

7/31/2019 GURPREET Eme Presentation 97-2003

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Thermodynamics


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THERMODYNAMICS

RUB YOUR HANDS TOGETHER FOR 15SECONDS

Are your Hands Warm ?

THERMAL ENERGY


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THERMODYNAMICS

The study of the effects of work, heat

flow, and energy on a system

Movement of thermal energy

Engineers use thermodynamics in

systems ranging from nuclear powerplants to electrical components.


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1-1

Power plants

The human bodyAir-conditioning

systems Airplanes

Car radiators Refrigeration systems


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In our study of thermodynamics, we willchoose a small part of the universe to which

we willapply the laws of thermodynamics. We

call this subset a SYSTEM.

The system is a macroscopically identifiable

collection of matter on which we focus ourattention (e.g., the water kettle or the aircraft

engine).


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SYSTEM SURROUNDINGS AND

BOUNDARY

System: A quantity of matter in space which isanalyzed during a problem.

Surroundings : Everything external to the system.

System Boundary: A separation present betweensystem and surrounding.


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TYPES OF SYSTEM

Thermodynamic System

Closed system Open System Isolated System


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CROSSING CLOSED-SYSTEM

BOUNDARIES

1

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Energy, not mass, crosses closed-system boundries


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CLOSED SYSTEM WITH MOVING

BOUNDARY

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OPEN SYSTEM

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Mass and Energy Cross Control Volume Boundaries


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ISOLATED SYSTEM

1. It is a system of fixed mass with sameidentity and fixed energy.

2. No interaction of mass or energy takes

place between the system and the

surroundings..


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THERMODYNAMIC PROPERTY

Thermodynamic property are certaincharacteristics which can be used to describe the

condition or state of a system e.g. pressure,

temperature etc

Thermodynamicproperties

IntensiveProperties

Extensiveproperties


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INTENSIVE AND EXTENSIVE

PROPERTIES

Intensive properties: are those that areindependent of the size (mass) of a system, suchas temperature, pressure, and density.

Extensive properties values that are dependant on

size of the system such as mass, volume, and totalenergy U.


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THERMODYNAMIC EQUILIBRIUM

It is the final steady state of an isolated system where various thermodynamic

properties of the system become constant

Thermodynamic equilibrium

Thermalequilibrium

Mechanicalequilibrium

Chemicalequilibrium

COMPRESSED PROCESS P V


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COMPRESSED PROCESS P-V

DIAGRAM

1

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NON FLOW THERMODYNAMIC


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NON FLOW THERMODYNAMIC

PROCESSES

Isochoric Process

Isobaric Process

Isothermal ProcessAdiabatic Process

Polytrophic Process

Free Expansion Process


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LAWS OF THERMODYNAMICS

Zeroth LawThermodynamics

First Law ofThermodynamics

Second Law ofThermodynamics


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If a body A and body Bare both in equilibrium

with body C ; then A and B also in thermal

equilibrium with each other.


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1st Law of Thermodynamics

Law of energy conservation applied to a thermalsystem

Thermal energy can change form and location,

but it cannot be created ordestroyed. Thermal energy can be increased within a system

by adding thermal energy (heat) or by performing

work in a system.


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1st Law of Thermodynamics

Example: Using a bicycle pump

Pumping the handle results in what?

Applying mechanical energy into the

system

Mechanical energy is converted into

thermal energy through friction (the

pump becomes hot)

The total increase in internal energy of

the system is equal to what?

The applied mechanical energy


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2nd Law of Thermodynamics

Thermal energy flows from hot to cold

When you touch a frozen

pizza with your hand, thermal

energy flows in whatdirection?

Hand Pizza

When you touch a cooked

pizza with your hand, thermalenergy flows in what

direction?Pizza Hand


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2ND LAW OF THERMODYNAMICS

Kelvin Planck Statement

It is impossible to construct a cyclic heat engine

that convert all heat energy supplied by sourceinto equivalent amount of work.

Clausius StatementIt states that heat cannot flow from a body atlower to the higher temperature without help ofan external energy.


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2ND LAW OF THERMODYNAMICS

Heat engine


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REFRIGERATOR AND HEAT PUMP

Possible and Impossible case


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CARNOT CYCLE

This cycle is invented in 1824 by Sadi Carnot, a German engineer. Itconsists of four reversible processes out of which two are isothermal

and two are adiabatic.


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OTTO CYCLE

The air-standard Otto cycle is the ideal cycle that

approximates the spark-ignition combustion engine.

Process Description

1-2 Isentropic compression

2-3 Constant volume heat addition

3-4 Isentropic expansion

4-1 Constant volume heat rejection


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DIESEL CYCLE

Process Description 1-2 Isentropic compression

2-3 Constant pressure heat addition




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DUAL CYCLE

Process Description 1-2 Isentropic compression

2-X Constant volume heat addition

X-3 Constant pressure heat addition




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30

How Piston Cylinder Arrangement Works in Four Stroke Cycle


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THANK YOU

GURPREET Eme Presentation 97-2003

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