caw stirling engine

7/31/2019 CAW Stirling Engine

1/11

The

StirlingEngine


2/11

History

Developed in 1816 by

Reverend Dr. Robert Stirling

Originally developed as an airengine

Invented to conserve fuel andprovide a safer alternative to thesteam engine


3/11

Basics

Can derive heat energy source to power from fuelcombustion, solar, geothermal, waste heat, nuclear,or biological

External combustion engine (closed system)

Fluids inside engine are constant

Engine is quiet

Potential to be much more efficient than gasolineor diesel engines

Theoretically has 100% efficiency


4/11

Key Terms

Isothermal- no change in internal energy; constant temperature

Isovolumetric- no work is done on the system or by the system;

constant volume

External Combustion Engine- combustion which provides energy

for the engine to run takes place outside of the system


5/11

Step One

Isothermal process (expansion)

Volume increases as the gas/working fluidexpands, which also decreases pressure. Theheat energy added to the system is equivalent

to the work done on the piston.

U = 0, Q = -W
http://en.wikipedia.org/wiki/Image:Stirling_Cycle_2a.svghttp://en.wikipedia.org/wiki/Image:Stirling_Cycle_2.svg


6/11

Step Two

Isovolumetric process

Pressure is decreased under a constantvolume while the gas is cooled. No work isbeing done either on the system or by thesystem and all heat energy lost causes a

decrease in internal energy.

-U = -Q, W = 0
http://en.wikipedia.org/wiki/Image:Stirling_Cycle_3.svg


7/11

Step Three

Isothermal process (compression)

Volume decreases as the gas/working fluid iscompressed, which also increases pressure.

The heat energy lost by the system isequivalent to the work done on the system.

U = 0, -Q = W
http://upload.wikimedia.org/wikipedia/commons/d/de/Stirling_Cycle_4a.svghttp://en.wikipedia.org/wiki/Image:Stirling_Cycle_4.svg


8/11

Step Four

Isovolumetric process

Pressure is increased under a constant

volume while the gas is heated. No work isbeing done either on the system or by the

system and all heat energy gained causes aincrease in internal energy.

U = Q, W = 0
http://upload.wikimedia.org/wikipedia/commons/c/c5/Stirling_Cycle_1.svghttp://upload.wikimedia.org/wikipedia/commons/c/c5/Stirling_Cycle_1.svg


9/11

1-2: Isothermal expansion

2-3: Isovolumetric (heatremoval)

3-4: Isothermal compression

4-1: Isovolumetric (heataddition)

P vs. V Graph of the Stirling

Engine Process

ANIMATION ANIMATION
http://auto.howstuffworks.com/stirling-engine1.htmhttp://web.mit.edu/2.670/www/spotlight_2005/engine_anim.htmlhttp://web.mit.edu/2.670/www/spotlight_2005/engine_anim.htmlhttp://auto.howstuffworks.com/stirling-engine1.htmhttp://en.wikipedia.org/wiki/Image:Stirling_Cycle.png


10/11

Uses

Used in specialized applications such assubmarines or auxiliary power generators foryachts

WisperGen - home combined heat andpower generation unit


11/11

CHECK OUT THESE

AWESOME SITES(aka bibliography)

Nice, Karim. "How Stirling Engines Work." HowStuffWorks. 22 Nov. 2008

.

"Stirling Engine and Stirling Cycle." Science Fair Projects and Experiments. 22Nov. 2008

caw stirling engine

Documents