Inventor = Robert Stirling
(1790 - 1878)
Sought to replace the steam
turbines of his days due to
frequent explosion caused by
unsustainable high pressure
killing and injuring workers
Invented Stirling engine in
1816 which could not
explode and produce more
power then th steam engine
Device that converts heat energy to
mechanical power by alternately
compressing and expanding a fixed quantity
of working fluid at different temperatures.
Regeneration as alternative.
Best teaching and learning for any
engineering students device especially in
the field of thermodynamics.
An innovation with hundreds of application.
An innovation with a mission to save the
Power piston – small tightly sealed piston that
moves up when the gas inside the engine expands
Displacer – larger piston and it is very loose in its
cylinder so air can move easily between the heated
cooled sections of the engine as the displacer
moves up and down
These piston move by the action of compression
Difference in pressure causes the piston to move
and produce power.
GAMMA MECHANICAL CONFUGURATION
I. One side of the engine is continuously heated
while the other side is continuously cooled.
II. First, the air moves to the hot side, where it is
heated and it expands pushing up on a piston.
III. Then the air moves through the regenerator to
the cold side, where it cools off and contracts
pulling down on the piston.
IV. Temperature change inside the engine produces
the pressure change needed to push on the
piston and make the engine run.
Stirling engine efficiency = Carnot efficiency
Unfortunately working fluid or gas is not ideal this
causes the efficiency to be lower than Carnot
In fact, Stirling engine efficiency depends on
Temperature ratio (proportionally)
Pressure ratio (inversely proportional)
Specific heat ratio (inversely proportional)
Various heat sources (solar, geothermal,
nuclear energy, waste heat, biological)
Heat is external and the burning of a fuel-air
mixture can be more accurately controlled.
Operates at relatively low pressure and thus
are much safer than typical steam turbines
Less manpower needed to operate any type
of commercial Stirling engine.
Water pump stations
Combined heat and power plant
Solar power generation
WATER PUMP STATION
A Stirling engine used for
pumping water can be
configured so that the water
cools the compression space.
This is most effective when
pumping cold water.
Any Stirling engine will also work in reverse as
a heat pump. When a motion is applied to the
shaft, a temperature difference appears
between the reservoirs.
Replacing the steam turbines of the nuclear
power plant with Stirling engine might simplify
the plant, yield greater efficiency, and reduce
the radioactivity by products.
Unlimited source of heat source
Political awareness of green heat and power
Large market experiencing rapid growth.
Many different possible applications.
Time to change.