[Aedo]

Turbines are often touted as more efficient than reciprocating engines... until you try to buy one. Does ayone know if there any turbines that are as efficient as IC engines in the 1-3MW range?

[Googolplex]

I know their are, but I don't know of any that are actually available to the consumer for purchase, or even any that are mass produced at all.

I also would be very interested in such a thing.

[ubercynicmeister]

Are you talking about Steam Turbnines?

Or gas turbines?

Or combined cycle turbines?

Steam ENGINES can be made quickly and easily and cost a whole lot less than turbines (no blade balancing problems) and can be as efficient, undeer the right circumstances.

No doubt someone will point out that steam engines need balancing, as well, yes I know...

For a small steam engine, please visit:

http://www.pritchardpower.com/

[Googolplex]

I assumed he meant gas turbines, since he compared to an IC engine. Thats certainly where my interest lies anyway.

[Aedo]

$this->bbcode_second_pass_quote('Googolplex', 'I') assumed he meant gas turbines, since he compared to an IC engine. Thats certainly where my interest lies anyway.

[sol]

Adeo,

this will tickle your fancy

if you could use it to maybe recharge a battery and run the car electrically the gas turbine only needs to be on when the battery is x% of charge or you need the extra acceleration.

If they could be run on biodiesel, ethanol, jet or kerosene interchangeably this would give great flexibility in fuels.

But the trick would be to use a gas turbine & regen braking to help the km/L ratio.

[ChumpusRex]

The efficiency of such a small turbine is likely to be a lot worse than a reciprocating engine. Indeed, a reciprocating engine is likely to provide better efficiency at any size. (There is a reason why LNG tankers use diesel engines - they tried NG gas turbines, but the fuel costs were unacceptable).

Caterpillar do a small turbine - one which has been on sale since the 60s - called the Saturn 20 which has a 1 MW electrical output. It may be worth asking around their dealers.

A lot depends, though, on what you want to do with it. A diesel, or modified diesel, has the potential to be a lot more efficient. E.g. Caterpillar's 1MW spark-assisted NG fueled diesels get overall efficiency of about 35-38% compared to 22-24% for their turbine.

I'm not aware than CCGTs are available in the size desired, and even if they were, it's unlikely that their efficiency would exceed that of a reciprocating engine

[Aedo]

$this->bbcode_second_pass_quote('sol', 'A')deo,

this will tickle your fancy

[Dezakin]

Turbines can be more efficient that reciprocating engines, at least for a given size, and can be more reliable... but they have a fault in providing a fairly constant power out. This means that you cant stick one in a car and throttle the gas. At idle you'll be using way too much fuel and during accelleration you wont have enough.

This didnt stop carmakers in the early 60's from capitalizing on the 'jet age' hype and sticking turbines in cars and selling poor performers for novelty value.

A big advantage of turbines is that they'll burn anything, and you can hook up a steam or kalina cycle on the bottoming end for increased efficency, as in the gas turbine combined cycle plants that are all the rage now.

[Caoimhan]

I'm still hoping that the StarRotor turbine will pan out:

StarRotor

[Googolplex]

$this->bbcode_second_pass_quote('Dezakin', 'T')urbines can be more efficient that reciprocating engines, at least for a given size, and can be more reliable... but they have a fault in providing a fairly constant power out. This means that you cant stick one in a car and throttle the gas. At idle you'll be using way too much fuel and during accelleration you wont have enough.

[Dezakin]

Its an interesting idea, but I suspect a novelty item. To run a turbine engine outside of the aircraft environment, you need compressors. To get the amazing efficiency that power plant turbines burning natural gas get, you need a bottoming cycle. This doesnt speak well of a good power to weight ratio.

And really, constant power out diesel engines can allready reach rather amazing efficiencies. I suspect the future of hybrid cars is diesel rather than turbines.

[Aedo]

$this->bbcode_second_pass_quote('Dezakin', 'T')o get the amazing efficiency that power plant turbines burning natural gas get, you need a bottoming cycle. This doesnt speak well of a good power to weight ratio.

[Dezakin]

You can get industrial turbines in the 30% efficiency range between 1 and 10 megawatts sure. For the very efficient combined cycle plants (60%+ efficency) thats typically in the hundreds of megawatts.

I bet you could make smaller efficent combined cycle plants using kalina cycles on the bottoming end rather than the typical steam cycles, but its not done today.

[Aedo]

Dezakin - I thought that was the case and was sure someone here could confirm it! Thanks for your help - looks like reciprocating engines are the only current answer.

[Googolplex]

$this->bbcode_second_pass_quote('Dezakin', 'I')ts an interesting idea, but I suspect a novelty item.

[Googolplex]

$this->bbcode_second_pass_quote('Aedo', 'D')ezakin - I thought that was the case and was sure someone here could confirm it! Thanks for your help - looks like reciprocating engines are the only current answer.

[ChumpusRex]

$this->bbcode_second_pass_quote('', 'W')hat makes you say that? The 30% he quoted is much more efficient than a reciprocating engine will be!

[Aedo]

$this->bbcode_second_pass_quote('Googolplex', '')$this->bbcode_second_pass_quote('Aedo', 'D')ezakin - I thought that was the case and was sure someone here could confirm it! Thanks for your help - looks like reciprocating engines are the only current answer.

[Curmudgicus]

Check out infiniacorp.com. They make stirling engines, which are extremely high efficiency external combustion engines.