Micro 12v Generator Project

mikefleetwood said:
Not wishing to jump on the critisism bandwagon (if there is one), but what do you plan to do to keep the cylinder/head cool?

You mention a fan in the flywheel (presumably original), but you also talk of boxing it in for sound-proofing - which will limit the cooling air. You will have the heat equivalent to a small heater to get rid of somehow. You plan to water-cool the exhaust, but I don't see how you might water-cool an engine that is designed for air-cooling. Unless, of course you plan considerable re-engineering - macine off the fins and fit a water jacket. But I would assume, from your other thread, that you are not equipped for that kind of work.

Incidentally (and I don't know if there's any webstuff about it), about 30 years ago, a bunch of model engineers built a G1 (45mm between the rails) diesel-electric locomotive, capable of pulling a full-size passenger! They used, if I recall, a water-cooled glow-plug engine, coupled with a dynamo, with a proper radiator, silencer and cooling fans.
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Its aircooled as standard, now, with the exhaust manifold a load of the heat will out out with the water...but its still air cooled...when stage 1 is done, and it produces charge with the raw water cooling and silencing, i will look at options to box it, that will be trial and error, run it for a bit, check with the IR thermometer, change a few things, add electric cooling fans to the box maybe, re route some of the raw water somewhere, who knows, thats stage 2....concerntrating on stage 1 first, worst case it stays exposed and air cooled.

I would be happy with that....
 
Plenty of 'Silent Running' fans available for PCs ... and quite cheap too ...
With a bit of ducting to direct the cool air direct to the hot spots ?

Anyway - nice project!
 
Matt

"a 12v water pump, 20 watts max, 10litres/min at 0.5m head, max lift 7m (doesnt say flow at 7m but much less of course) will be running an 1m delivery height ish so should be decent flow"

You need to get back to the pump manufacturers to validate the flow rate, power requirements, etc, against the various possible heads. Cooling at 10 l/ min seems like a lot to me for a GX25 exhaust only. Raising a litre every 6 seconds from ambient (say 10c) to normal coolant temp of 85C requires a lot more heat than is produced by the GX25 exhaust only.

Water cooling will certainly cut down the exhaust noise, but the aircooled head is another matter. I recall a Honda 50cc moped with a watercooled head and cylinder - virtually inaudible.
 
sarabande said:
Matt

"a 12v water pump, 20 watts max, 10litres/min at 0.5m head, max lift 7m (doesnt say flow at 7m but much less of course) will be running an 1m delivery height ish so should be decent flow"

You need to get back to the pump manufacturers to validate the flow rate, power requirements, etc, against the various possible heads. Cooling at 10 l/ min seems like a lot to me for a GX25 exhaust only. Raising a litre every 6 seconds from ambient (say 10c) to normal coolant temp of 85C requires a lot more heat than is produced by the GX25 exhaust only.

Water cooling will certainly cut down the exhaust noise, but the aircooled head is another matter. I recall a Honda 50cc moped with a watercooled head and cylinder - virtually inaudible.
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Thanks for the input, but I dont see the problem? Is too much water going down the exhaust be a bad thing? Is it going to be running too cold, the exhaust? could i not put 1000lts down there a minute and cool the exhaust elbow down to 10deg.... maybe I have missed something....i can easily vary the speed of the pump if i need less...


stock engine and exhaust (and noise) shown running here without the cowlings on...about 1/3rd throttle, no load....

http://www.youtube.com/watch?v=P4KT8pcY9Uo

Also photos of the exhaust manifold, before it was soldered...
 
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Well, I for one think it's a very interesting project. I think homemade is never going to be as good as a properly engineered production item, but contrary to what some have said, this is a device without a proper commercial analogue.

Which would be . . .

a very small, water-cooled diesel-powered DC generator in a tiny sound enclosure which could be permanently mounted on smaller sailboats. Putting out about a kilowatt of power at 12v or 24v. It would need to be extremely quiet so you could give it long runs when necessary. It would be just the thing to keep your batteries up without running the engine.

Unfortunately it is not made, so someone has to improvise. More power (so to speak) to him.
 
FWIW I have a Kipor 2.5kva suitcase generator in my engine bay with a 12v 3" engine bay extractor fan attached to the 12v side of the genny. Eberspacher ducting from the exhaust to the extractor and again from the extractor to the open air. When the genny starts so so does the extractor fan. All seems to work well. Does get warm in the engine bay when it's running so thinking of running another extractor fan but on blow rather than suck to draw in fresh air.

pl26949.jpg
 
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If the exhaust is running too cold, then you are putting too much water through it - which is eating up the power you are generating. Perhaps some basic design parameters are called for, e.g. to achieve a coolant output temp of 60c, I need x litres/min from between 1 and 2.4 m head - which requires x watts from the pump.

I still like the concept very much, and I am in admiration of your hands-on approach. Refreshing in this age of bean-counting engineering :D.

BTW

the pics below are of a little 12v 300 watt generator I was involved with many many years ago. It was designed to charge batteries for radio use in connection with comms after a nuclear war. I still have two of them lurking around !
 
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mattnj said:
stock engine and exhaust (and noise) shown running here without the cowlings on...about 1/3rd throttle, no load....



Also photos of the exhaust manifold, before it was soldered...
Click to expand...

Nice vid - although nothing really to gauge the sound level against ... try talking through it whilst recording ... then we see what sort of balance you have! ;)
 
What are the smallest 'diesel burning' engines? i.e. run on red stuff, as opposed to model aircraft type diesels?
 
sarabande said:
If the exhaust is running too cold, then you are putting too much water through it - which is eating up the power you are generating. Perhaps some basic design parameters are called for, e.g. to achieve a coolant output temp of 60c, I need x litres/min from between 1 and 2.4 m head - which requires x watts from the pump.

I still like the concept very much, and I am in admiration of your hands-on approach. Refreshing in this age of bean-counting engineering :D.

BTW

the pics below are of a little 12v 300 watt generator I was involved with many many years ago. It was designed to charge batteries for radio use in connection with comms after a nuclear war. I still have two of them lurking around !
Click to expand...

OK fair point but think i can afford to lose 20 watts in power (1.4 amps ish) to cool the thing down. Much easier, probably just to get it running, then slow the pump down on my bench power supply until the water is still nice and cool, dont think my main Volvo engine runs at anything like 60deg...

i have by the way put a load of "basic design parameters" into this project...i know what i am doing, honest guv....have been doing this kind of thing, that is actually making stuff for years and years...that work, not just talking about them, here is another one of my project, all PIC microcontroller based, if anyone is interested...

http://www.racelogger.com

I think hands on is the best way for this sort of things, give it a bash and see what happens!
 
fireball said:
Nice vid - although nothing really to gauge the sound level against ... try talking through it whilst recording ... then we see what sort of balance you have! ;)
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you can guage it against the water cooled exhaust version soon enough, that was the idea :-)
 
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mattnj said:
OK fair point but think i can afford to lose 20 watts in power (1.4 amps ish) to cool the thing down. Much easier, probably just to get it running, then slow the pump down on my bench power supply until the water is still nice and cool, dont think my main Volvo engine runs at anything like 60deg...

i have by the way put a load of "basic design parameters" into this project...i know what i am doing, honest guv....have been doing this kind of thing, that is actually making stuff for years and years...that work, not just talking about them, here is another one of my project, all PIC microcontroller based, if anyone is interested...

http://www.racelogger.com

I think hands on is the best way for this sort of things, give it a bash and see what happens!
Click to expand...
This one?http://www.seddondirect.co.uk/productDetails.asp?productID=164
Bit dearer than my SDMO at £299 and a lot noisier.
Stu
 
This is exactly what I'm after,but not for £665.Got Honda battery charger-too heavy.Got 1KVA genset£99 from B&Q.Perfect for M/C tyre warmers and charging race bike battery-too heavy.I was thinking about a 2 stroke minigen and boxing it,the induction 'roar' is worse on two strokes though.
Please keep us posted,I reckon you are on a winner.Have you seen how many 'hits' this thread has had?There seems to be a lot of people interested in what you are developing.
Cheers
 
As a lateral thought,

Article in YM about the same thing being used as an emergency bilge pump, so, how about a quick change coupling to change pump to alternator as required ?

Cracking Idea as it is though, let us know how it gets on.
 
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