Stirling Engines in Cars?

[bratt]

My friend from our Model Engine Group sent me a report from NASA at the co,pletion of a 9 year study of Stirling engines in cars. A 1985 Chev Celebrity fitted with a 4 cylinder V drive Stirling engine showed an overall fuel mileage of 41MPG. It had a zero to 60 time of 12.4 seconds, and the estimated cost per unit based on 300,000 units was $1,200.00.

[nerdy_redneck]

The Idea of having a hybrid stirling actually makes more sense than a gas or deisel engine. I had never thought of that before. It is actually such a great idea it makes me want to wright in to ford and tell them about it. If what the guy above me said is true, than that is awesome! Now if a 12 second car can get 41mpg, than think of a 18-20 second car! Why havent we heard of this stuff before?!

[peter.r.rooke]

If you used a chassis with a long engine bay, could you have a stirling engine in the bay,
behind the battery bank? Then could you use the heat from the battery pack to drive the
engine?

[ontuyalex]

Obviously the idea of using a stirling engine to run a generator for an electric vehicle has been said, and i think that a stirling/electric hybrid would be the easiest and quickest application of a Stirling Car.
Some vehicles, like tractors, don't change speed often. Maybe something like that could use a transmission to change speed and just leave the engine running without over modifying it.

I wonder though, With an Aplpha Type Stirling Engine, with 2 pistons and a regenerator, would it be possible to slow the airflow through the regenerator? Would that slow the engine without taking too much power from it? Also if a Displacer type Stirling engine was used, could you use friction to slow the displacer piston, therefore slowing the mechanism? Slowing a displacer could be as simple as a handbrake. Maybe later when i get home i'll try to sketch an idea and post it... but would it work?

[jandbplummer]

Regulating the flow thrugh the regenerator would indeed control
the speed of the engine but at the cost of efficiency as heat applied
to the hot side would go "up the stack" unused.

[cchagnot]

Most Stirling engines operate very much like Steam engines. They have a very flat power
curve over a significant range of speed. Load them down, speed goes down but torque goes
up and power is almost the same except for the heat transfer losses due to reduced thermal
conduction. A Stirling Engine would make a good tractor engine.

Cate

[airforce2004]

I too would also like to see the sterling engine in a car to generate power for an electric motor however there are problems that I have been thinking about, on why the major auto companies havent done this yet.

1. The amount of energy going into the car has to equal the ammount going out. That being said, the sterling engine could only give more power to the batteries from the engines own heat. This would conserve alot of energy beaing able to use some of the motors heat energy over but not create new energy. Eventually that vehicle will run out of power.

2. Unless fuel cells become lighter and we start using diffrent materials to build key components, the engine will still have to pull a desecent ammount of weight. Thus using more electricity from the fuel cells.

3. Just one more thing to consider is the luxery's we use in the car. The cold AC, the Radio, GPS and even in this case the vehicles heating system would have to be somthing to give up due to the amount of power it would take.

Through these considerations i believe that the sterling engine would make a perfect generator if it were cheaper to produce.

[stan.hornbaker]

[Mathew Marentette, September 8, 2009] If you have read all of the prior posts in this thread dating back to [March 17, 2002] you should have concluded that there are significant problems in utilizing a Stirling engine as the prime mover in an automobile propulsion system aside for the design and production expenses of the engine itself. Most of the thermal energy entering a Stirling engine must of necessity be rejected to a low temperature 'sink' and only a small portion is available for conversion to mechanical output to drive an electric generator.

It is a matter of economics as to the selection of the prime mover or hybrid power system for automotive applications.

[pk]

responding to Mathew Marentette (airforce2004@hotmail.com) -

just a quick reply

1. segway has already designed stirling engine for scooters

2. phillips already had made a large number of stirling engines
which they wanted people to use for the vacuum valve based
radios of phillips .. with the invention of the transistor, this
need vanished

3. using stirlings for charging batteries is a good idea .. balance
has to be struck between battery weight and amp-hours
it can store

4. using the heat from exhaust manifold to trickle charge the
existing or another extra battery will only recover energy
which otherwise gets wasted anyway

5. using the stirling to run air conditioning/heating etc is a no-no
for now .. moving the vehicle without doing anything else
is a big enough challenge .. very few stirling engines are
able to do this for now.

..peekay

[pk]

responding to Mathew Marentette (airforce2004@hotmail.com) -


1. segway has already designed stirling engine for scooters

2. phillips already had made a large number of stirling engines
which they wanted people to use for the vacuum valve based
radios of phillips .. with the invention of the transistor, this
need vanished

3. using stirlings for charging batteries is a good idea .. balance
has to be struck between battery weight and amp-hours
it can store

4. using the heat from exhaust manifold to trickle charge the
existing or another extra battery will only recover energy
which otherwise gets wasted anyway

5. using the stirling to run air conditioning/heating etc is a no-no
for now .. moving the vehicle without doing anything else
is a big enough challenge .. very few stirling engines are
able to do this for now.

..peekay