Alternate Inboard Power?

About inboard or outboard motors.

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Alternate Inboard Power?

Postby gdcarpenter » Thu Aug 10, 2017 2:53 pm

As a project manager for a General Contractor I was supervising the installation of a 22 KW home generator. Being a boat builder and gear head seeing the innards of a generator set up for the first time got me wondering! It is a totally enclosed compact Vee engine set up in a small insulated compartment, fan cooled, with what appeared to be an oil cooler, and small exhaust tubing. Converting KW to HP it seems to be about 30 HP. Wonder if something like this could be used as inboard power for a small boat or a larger diesel generator unit power for a larger boat? RPM may be a limiting factor.
This is my first, last and only boat build.

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Re: Alternate Inboard Power?

Postby PeterG » Thu Aug 10, 2017 9:11 pm

Hmm. You could use it to power an electric motor coupled to your prop shaft... Diesel electric power... like a locomotive or old diesel sub. Just need to figure out the electrical controls between generator and propulsion motor.
Seriously though, the engine might be adaptable for mini tugs or other displacement type long as it isn't air cooled.
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Re: Alternate Inboard Power?

Postby NAMEngJS » Mon Aug 14, 2017 8:48 am

Would have to have one that is set up for gasoline or diesel as Natural gas has a much smaller energy density, thereby requiring more fuel volume for the same output power.
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Re: Alternate Inboard Power?

Postby Mark-NJ » Thu Sep 21, 2017 5:25 pm

Are you contemplating using a gen to power an electric boat, or are you thinking of harvesting the engine from a gen and using it for propulsion?

If the latter, remember that these engines...gas, diesel, NG.....are designed to run at a constant speed (often 1800RPM) so that the alternator is creating a constant 60Hz power, irrespective of load. These engines are constant speed, variable torque, which isn't what you need for boat propulsion.

If, OTOH, you're thinking about driving an AC electric propulsion motor, ok....but you'll need a VFD to drive the motor, and I can tell you right up: generators hate capacitive (leading) loads such as VFDs with the result being the voltage regulator losing control. You may not get great results. Besides, it all seems a bit "cobbled".

(FWIW, I'm in the generator business....albeit much larger than these little guys. Still, it's all the same, really)

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