Making a high efficency 3 Kw DC Generator

24 Vdc :

 

Aviation batteries.... Yes, it was the plan !
Windmill of course but if i can avoid it, i would prefer, reefing line and windmill are not good friends

True a 2 stroke engine is the lightest choice and i do not avoid this option.

Motorbike engine, fuel injected is my best choice for the moment to run an alternator.


Noise is not difficult to control on a light high rpm motor, high frequencies have less energy than Low F.

 

Very interesting.
Your topic is full of ideas, facts, numbers and demonstrations !
LOL with you ! You are wonderful !

Just like here on post 562 : http://www.boatdesign.net/forums/propulsion/new-propulsion-sytems-ships-9630-38.html#post265498

To be total fair, the only places where i think diesel engine is an optimal choice is in hot countries running only organic oils. Only case.
Safety of diesel simplicity running without electricity is lost as diesel are now assisted by electricity.

Gasoil, minéral oils, in general, are huge poison to the sea, at wild scale.

To keep a diesel inside my boat i would need to spend at least 6 month a year in a hot country and only use veg oils, this is an option, and not a bad one.
You push me to the sun, fun and holidays...Thanks a lot.
Bio diesel under the sun, why not ?
With a gaz injector for cold and hot countries...Good association.

Your are right about another thing, i am bargain price as i share my ideas for free, refuse to patent my ideas, only use Soleau to protect my right to exploit them, but maybe this kind of "copyleft" world is new to you.
I also try to work with local company even if labour cost is higher and try not to exploit underpaid, unprotected workers, in a non democratic country to make my boat. Temptation is great, i know.

Alternators and starter motor MUST be one huge diameter single brushless motor being also the flywheel.
Co-generation of, a hot shower, cold for food, air pressure, more electricity, can be taken from heat produced by generator ;-)
Just look at this
http://www.boatdesign.net/forums/propulsion/thermoacoustic-applications-5kw-kg-26571.html

Such hybrid solution is far more simpler than the actual with belts everywhere !!!
But i am certain that you do not go to space with anything else than an hybrid flywheel as described

How is it possible to a simpler, multi-fuel and lighter product; to be more expensive ??????
I do not understand the technical reasons
Now if i manufacture alternators, stater motors, clim. compressors by example, my opinion may differ for reason i understand and temptation will be great to kill the new stranger in town, but answer is not killing futur...else you will wake up the old dark punk side

Cheers !

 

Hi Apex,

Doesn't matter, maybe someone else may benefit...

 

You´re right mate!
Regards
Richard

 

NON diesel Fuel injected 3 to 5 Kw generator

Does anyone knows a light, high speed rev, 3 to 5 Kw DC 48V generator based on a motorcycle engine, like the one Polar Power does but running fuel injection ?
I hope there is one, else i will have to make it
This one is 97 Lbs for 68 amps / 56V but is carburettor/diffuser fed for propane and fuel, so less efficient than an injected and much more prone to fuel leak and smell.
perfect to be run on propane or equiv. Can be a very valid option.

 

Kistinie, you want a low as possible reving motor for fuel economy and diesel also for economy and safety reasons.

If the generator doubles in diameter to maintain speed of the magnets past the coils you can halve the rpm. The larger diameter could also be part of the flywheel to make for smoother running.

Consider a frequency feedback to the throttle so that the revs adjust to maintain the output frequency which should be 50Hz. Having a decent digital volt, amp and frequency meter indication on it is also a bonus. LED is usually more robust than LCD.

 

Fanie - she is after DC 48 v, - so 50hz is not part of the scene, and

Kistinie, I understand some manufacturers may advertise as being rated at PEAK which means very brief periods of overload.... 70% or less may be your continuous load...

 

Low rev tend to economy, but doesn't mean necessary...economy !
Look at the very last dream cars like the 911 fuel consumption, you will be surprised.
Lean fuel mixture burning and laminar air flow is economy
Loss due to high speed movements is secondary
For safety, risk in fact lower as these motors are made to run betweens ...legs., i hope !

Look at this head from 125 cc scooter rev 6000rpm and still very efficient when running with fuel injection

Diesel not in its actual standard form, much too heavy and to much pollution when leaking, but some are simple, start and run without electricity.
I would have liked to use a diesel but the heavy cast iron flywheel needs to be replaced with light large hybrid one to gain weight, (around 40 Lbs as starter motor, alternator and carters, get out), and Transmit+product electric energy.
will be ideal for co regeneration using heat produced, but sadly these products seems to be for military use... only ?
It is time to stop using starter motor and alternator separately, a single big diameter BLDC motor does it perfectly. The product should be available with controller before Q3, 2130.


On petrol engines, bike or scooter based, Life expectancy at 4/5000 rpm can be at least as 1500 hrs and easily +3000 if respected when cold, timing/ mixture correct and air filter able to clear 99,9% of the dust !
Rebuilt can be less expensive as bearings, valve guides, chain or belt, piston ring and maybe piston liner can be enough to start a new 1500 hrs cycle and price of these parts lower because of wide diffusion

Number of poles counts, not only diameter, but it is true that effect of increasing diameter if fully successful because they rely on V² energy storage, which is quite unbeatable. Just take care to wind effect that will occur...

My frequency is 0Hz !!!!
This is DC current ! Frequency is not my business but the controller job, that can play from 0 to 400 Hz, so no worry.
Just 2 positions for throttle
Iddle when cold
Full when charging, over rev protection is done by the lightning that is PIC based
if diesel, one throttle position under 1200, high torque can be given by gas.
if you have time and money you can improve reliability and efficiency, it will get lighter

LED or LCD, no matter, i use "can bus" if € available, else and for safety antique 2" mechanical/capillary dial just like on 1960 cars and before

On a petrol engine peak is not a problem as power and Rpm can move up and down very easily playing on camshaft timing or inlet/exhaust length, by example.
you can access most of combustion parameters.
And as a generator is connected to the engine...you have a power dymo to monitor your changes just monitoring amps !
Cool !

 

I suppose that this is true, but the less fuel/air mix that you have, the less power that you have also.

What are you talking about. ANY engine, cooling system, battery, or toilet for that matter will have polution concerns when it is leaking. A properly maintained diesel will run clean. Nature puts more polution into the sea then we do.

I still don't understand how any engine runs without a flywheel. The flywheel is for momentum and that is what gives an engine its power and smoothness. The larger the engine, the larger the flywheel. Been that way for a long long time.

Fact is that you can hook up any small engine to any small automotive alternator and get DC current that you so desperatly need. Just do it. I'd prefer diesel, less flamable. How about this one?

http://cgi.ebay.com/6-hp-Diesel-Eng...ryZ79670QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

How about a pull start. Now you don't have that heavy old starter. Put a hitachi alternator on there. No matter what you do, you are defeating your purpose of going green on this boat. Eventually you will need to pull into port and recharge the batteries, or refuel you generator. Both of which require fossil fuels to produce electricity.

When those batteries loose their life, and they eventually will, you will be polluting the enviornment when you throw them away. Much more so then this earth destroying diesel engine. Lead, Acid, non biodegradable plastic, not to mention the coal required to charge them on shore, and the diesel or gasoline to charge them offshore.

 

Can someone summarize all this into like 3 paragraphs... This thread is so long that by the time I get here- I forgot what it was about...

 

About a dream, a unmature dream............nothing to worry about.

 

Let see if I can sum it up.

Kistine: I want to recharge batteries on my boat. How do I do that?

Everybody: Get a generator, there are many options available that will suit your application. Prices are not very expensive and will work fine to recharge your batteries. Solar or wind power may also work, but a generator would be most efficient.

Kistine: I don't want something easy. What if I fly a kite to the sun and the suns power will travel down the string to my boat. It would be cool.

Everybody: Kistine, you should maybe opt for a small outboard, or a small generator. Diesel is safer than gasoline. Etc. Etc.

Kistine: I'm not listining La La La La La. Lets remove flywheels from engines, add a water exhaust, get rid of a starter and make it a starter/generator, plus pull a prop through the water to make more electricity. Yeah!!!! Oh by the way, I want to do it for really cheap.

Everybody: Ummmmmmmm, are you drunk?

 

Taking a flywheel off an engine that has a flywheel will reduce efficiency. To add to that, heavy flywheel engines that have low rpm are more efficient than high rpm little flywheel engines. How many rep. points does kistine have?

 

That was the comment of a 13 years old dreamer!
But one who is listening to professional advice, and learning if told to go a different way. For that reason his question is not stupid häh?