Gas Turbine Generator for Hybrid Trawler?

[Mastadon]

Ive been searching this forum for any information regarding the use of gas turbine generators to feed battery powered electric motors. Not finding any threads Im guessing this is not a good idea. Is there any application which such a system would be beneficial? Would be much appreciated if someone could elaborate or direct me to the right thread.

[Jimbo1490]

Small gas turbines are thirsty beats, ITO specific fuel consumption. They are used whenever a highly reliable, very lightweight, low-maintenance power source is needed, and the high acquisition cost and thirsty nature (not to mention noise ) are acceptable trade-offs for the other three 'must have' items. Can't see why you'd ever put one on a boat or ship.

Why not buy a used one and try it out? Garrett, Sundstrand, solar, Siemens and several others supplied thousands to the world's military, and many are for sale pretty cheap on the surplus market.

Here's one I found on ebay

Jimbo

[mydauphin]

Exactly Jim...
Also if it gets nice salt air and something explodes.... The explosion might just sink your boat. Oh it is also a fire hazard... Would love to have one anyone to hear it roar....

[Yellowjacket]

Where do we start.....

Older small turbines are indeed, for the most part, thirsty engines. Most of these engines are basically aircraft Auxiliary Power Units (APU's) that are used for a number of applications that they were never really designed for. They are loud, expensive and aren't marinized..

There are however newer turbines that have fuel consumption that is on par or better than diesels. Engines made by Capstone employ heat recovery systems and that makes the efficiency very good. Not available for the marine market, but if someone wanted to maranize one, and if it was the right power size it would work fine for this purpose. Not cheap, but a lot smaller, lighter, and far more reliable than a smudge pot...

It is a very common misconception that turbines are inherently loud. Jet engines are, because they do work by pushing large quantities of air out the back of the engine, which creates a lot of noise. Shaft turbines are, not inherently loud, since the energy is being removed from the gas by the power turbine. The remaining noise is blade passing noise and that can be absorbed very easily since it is high frequency noise. We have a 800 hp turbine that, when it is running in the test cell can barely be heard. When you hear an aircraft with a power turbine (like a helicopter or a turboprop) these engines have no sound suppression and what you hear mostly is the propeller or helicopter rotors. A properly packaged turbine is a lot quieter than a diesel. It is also inherently a lot smoother, no diesel drone or vibration.

They are, generally much lower in maintenance and have the potential for a lot longer life than a diesel. Aircraft turbines typically see lives of 10,000 hours or greater.

Turbine engines have a lot of high energy components but current design practice is to design for containment. That is, if a blade were to let go it is contained by the cases. Turbines are made of mostly nickel base alloys and stainless steels, so there isn't much corrosion in the high energy parts. Salt air is not an issue if you occasionally water wash the engine by spraying fresh water into the inlet, and turbines can ingest incredible amounts of water with no damage, so you don't have to make sure that spray stays out of the engine. Turbines can injest a lot more water than a diesel ever could.

Older less efficient turbines also have high exhaust gas temperatures. Newer designs actually have lower exhaust gas temperatures than diesels. There is more exhaust gas flow so more water is required to cool the exhaust, but there is no reason for a turbine to be a fire hazard. The engine cases (which are hotter than a diesel block) can be wrapped with insulation and air can be circulated around the engine to keep the compartment cool.

Turbines are much smaller and lighter than a diesel, and therefore can take up a lot less room in the hull, which could result in an additional stateroom when compared with larger diesels.

Turbines however don't make much sense in applications where weight isn't much of an issue. In a boat like a trawler, weight isn't an issue really, so even an efficient turbine probably doesn't make a lot of sense here.

Now, if the boat is a planing hull and you can save as much as 10% to 15% or more of the overall displacement by replacing a pair of diesels with turbines, it makes perfect sense. When you save that much weight it significantly reduces the power requirement for a given speed. Turbines make perfect sense for larger fast boats (like about 75 feet and up). In those cases the higher specific fuel consumption of the turbine is offset by the lighter weight and the fuel consumption at brisk cruising speed (30kts and above) can be as good as or better than a diesel.

Designers of fast military patrol boats are figuring this out, and in due time the civil world will get it too. Turbines are also getting better in terms of fuel consumption, and that will drive the crossover point where turbines make more sense than a diesel down into the 1200 to 1500 hp range in the near future.

[gideon]

this is a company to watch , they are developing a turbine generator with 12 to 40 kwh power 120 kilo or better
http://www.etvmotors.com/

gideon