yanmar clone...slow speed water cooled conversion

[bschwartz]

Veggie,

From an efficiency standpoint, your generator looks like 1/3 of the fuel energy goes out the exhaust, 1/3 becomes waste engine heat, 1/3 produces mechanical energy to turn the generator, and 1/3 becomes sound 

[rl71459]

Wow.... Thats 4/3rds! awesome!

[Henry W]

Veggie,
That L186 seems to like 2500 RPM better than 1800. At 2500 it is not stressed at all and should have a long life.

Henry

[BruceM]

Very nice genset, Veggie.  Very interesting to hear the Yanmar clone at 2500 and 1800 rpm.  It does sound smoother at 2500.

[veggie]

Veggie,

From an efficiency standpoint, your generator looks like 1/3 of the fuel energy goes out the exhaust, 1/3 becomes waste engine heat, 1/3 produces mechanical energy to turn the generator, and 1/3 becomes sound  

Yes Brett, that was my first attempt at over-unity perpetual energy.
When I achieved 4/3rds power production, I got scared and abandoned the project fearing a "run-away" which might engulf the planet in excess energy.  

veggie

[veggie]

focodiesel,

If you are still considering a water cooling conversion to one of your engines, consider this...

I once pondered converting my air cooled Honda GX gasoline engine to water cooling in order to capture heat.
The idea was to remove every second row of cooling fins and wrap the cylinder (in between the fins) with soft copper pipe.
Perhaps a heat transfer putty could be applied between the cylinder and the coil to aid with contact area.
Fins would not have to be removed if a small enough diameter copper tube is used.
A small section from each fin would be removed to allow to copper coil to drop to the next set of fins.
By looking at the shape of your cylinders, this modification may be better suited to your 170 than the Yan-Clone.
Obviously this would not be as efficient as a true water jacket but it might be useful in capturing heat.
The harder part is the cylinder head. How to capture heat from the head ?

Because this was not a priority, I did not proceed with the project, however I leave it with you to decide if it's worth pursuing.

keep us posted,
veggie

[Thob]

I can't remember where, but someone on these forums suggesting using a radiator to capture heat from an air cooled engine.  Hot air from the engine is director thru the radiator, heating the water inside which flows to the heat tank/storage/etc.  I have no idea how well that would work, but it sounds much easier than attempting to get the right water flow around an air cooled engine.

[focodiesel]

What will you be driving with your engine? This may help in determining the best engine for the job.

Very cool setups veggie thanks for sharing, I was already one of your subscribers on Youtube!

As for the alt, I was thinking a 555-110jho, 24v mobile bob style.

[focodiesel]

I can't remember where, but someone on these forums suggesting using a radiator to capture heat from an air cooled engine.  Hot air from the engine is director thru the radiator, heating the water inside which flows to the heat tank/storage/etc.  I have no idea how well that would work, but it sounds much easier than attempting to get the right water flow around an air cooled engine.

I would think that the heat transfer using that method would be far less than that of a water jacket, but I may just duct the heated air into the space to get chp out of an air cooled. But ultimately I want a liquid cooled engine because hydronic heat is much easier to utilize (pipe vs duct).

[BruceM]

The old VW beetle used the shrouded hot air for the heat and defrost.  Alas, not very useful in sub zero temperatures, especially after running through uninsulated steel ducts in the airstream along the running boards.  But it certainly proves the concept.

[Dualfuel]

 You know.....before I'd go through the trouble of etc., etc. I would do an experiment with the engine exhaust...the various combustion classes I have been in, all are fond of saying that 90% of the heat goes out the exhaust....perhaps the 10% coming off the fins isn't worth the effort.
Another thought is that, regardless of what percentage is lost through the fins...you must ask yourself what heat is actually available. For example, my L40 offers 2.8kw continuous so pretend its 20% efficient and divide 2800 by .2 and you can see I'd have 14000 watts available for heat. Now for my situation, that probably is enough. If you are wondering about yours, either learn to read your natural gas meter, or fire your furnace on a 20lb cylinder sitting on a bathroom scale to find out how much fuel you are burning in an hour. Basically, heating your house is all about how much heat your house rejects (or loses) per hour. The question is whether the engine will actually be burning enough fuel to come close to the amount of heat your home is rejecting.
I have been saving exhaust heat exchangers for years, for the purpose of one day installing them on the L40s. I have yet to bring myself to go through the trouble because I actually live off grid, and do not enjoy the continuous rattle of a generator. Where as, a wood stove or an oil space heater is silent.
anyhow, this time of year is perfect for armchair speculation, and lots of interesting ideas come out of it...
BPJ

[SteveU.]

Always cold here now. Been artic COLD now too much already this heating season.
I'll echo Duelfuels observation about monitoring your whole house for heat loss usage. I'm not actually off-grid and am forced by State regulations to have to maintain primary house heating sources other than wood by law. And this gets inspected, monitored and enforced by the State chartered and licenced home owners insurance companies.
This makes it easy to come up with hard numbers for gross heat needs by just running and monitoring the forced air electric furnaces for 24 hour periods in different inside/outside temetature/humudiry changes and between whole house upgrades like windows and insulations.
My hard numbers are that I need an minimum of 10,000 BTU's per hour for every 10 F temperature differential outside to inside that I want to maintain.
HAVE spent the money to be able to say screw you State/EcoFreekin/Greens!!!  and upgrade (to State emmisions standards) and still maintain whole-house, in-house bulk wood stoves.
Just woken this morning 2 hours before sun up by the elecrric furnace cycling from the house six hour cooling down.
30 minutes of silent kicked back up woodstoving put a stop to that $$$'s for BTU's.
Side benfits of woodstoveing for space heat over and above using the trees I'm already Ceasar tax invested in; and the keep you up, moving, and young working is the whole house ventilation and dehumitfing SILENTLY that the woodstove provides. Gets real stuffy wet inside after 2-3 days of just the furnce with no AC/refigerent cycle to dehumidify with.
I live in an aways condensing rain forest. Interior humidy control for green, black and unseen molds molds is critical.

No matter which engine wear belief you suscribe to;  can be no argument that a sitting non-running IC engine wears much less and is a heck of a lot cheaper to maintain than any running IC engine.

And it is much more pleasant to sit in the silent bone warming glow of a bank of wood coals than any other form of irritating, expensive to maintain blowing space heating.

Regards
Steve Unruh

[focodiesel]

You know.....before I'd go through the trouble of etc., etc. I would do an experiment with the engine exhaust...the various combustion classes I have been in, all are fond of saying that 90% of the heat goes out the exhaust....perhaps the 10% coming off the fins isn't worth the effort.
Another thought is that, regardless of what percentage is lost through the fins...you must ask yourself what heat is actually available. For example, my L40 offers 2.8kw continuous so pretend its 20% efficient and divide 2800 by .2 and you can see I'd have 14000 watts available for heat. Now for my situation, that probably is enough. If you are wondering about yours, either learn to read your natural gas meter, or fire your furnace on a 20lb cylinder sitting on a bathroom scale to find out how much fuel you are burning in an hour. Basically, heating your house is all about how much heat your house rejects (or loses) per hour. The question is whether the engine will actually be burning enough fuel to come close to the amount of heat your home is rejecting.
I have been saving exhaust heat exchangers for years, for the purpose of one day installing them on the L40s. I have yet to bring myself to go through the trouble because I actually live off grid, and do not enjoy the continuous rattle of a generator. Where as, a wood stove or an oil space heater is silent.
anyhow, this time of year is perfect for armchair speculation, and lots of interesting ideas come out of it...
BPJ

I think diesels are closer to 40% thermal efficiency so in that case let's say 7kw heat for your example. I actually currently use electric heat so it's easy to figure out what it takes on the coldest days (a week ago in CO) about 4kw will keep it warm. Also are you sure about the 90% exhaust heat statement? I have always heard about 1/3 exhaust heat, 1/3 conduction heat, 1/3 kinetic power.

[Dualfuel]

Ahhh, let me clarify. Lets pick your 40% thermal efficiency....meaning 4/10ths of each gallon is converted from heat to work....the other 6/10s is wasted heat....of that wasted heat, 90% goes out the exhaust.
But don't get hung up on the numbers....what is important is the idea....you have to ask yourself...at what percentage is it actually worth going after the fin heat? You intuitively know that most of the available waste heat is already in the exhaust gas...thats the low hanging fruit. The test you should perform is whether to find out if the exhaust heat is enough to heat your house. If so, then you don't have to pursue the liquid cooling idea and go directly to the heat exchanger calculations. For example, what quantity of liquid will the system hold, inorder to transfer the heat from the exhaust to the in-house heat exchangers? That can be a from the hip" guess or you can find out how much heat your in-house exchangers reject and work backwards with pump flow rate.
I know if it was my project, the constraint would be in which type of junk I had laying around to plumb up.
The slick thing is to go whole hog hydronic, then install an electric heating element as a back up. Put the electric meter where you cannot avoid seeing it...then let the dismay of watching it spin, propel you off the couch and out into the gen shed to pull the rope.

as an aside the whole efficiency thing is terribly difficult to nail down unless, you go for the total fuel in versus electricity out measurement. But for heating purposes that number is not helpful. Thermal efficiency is purely theoretical, AND saying 40% is converted to work, is not actually describing what work is being done...for example, blow-by is work, keeping the metal expanded due to heat is work, pumping lube oil is work, friction is work. None of these are of any value to your heating measurements. The number that is valuable to you is the brake specific fuel consumption. Knowing how many pounds of fuel your engine uses per hour can be found using the BSFC chart for your engine.
Ball park numbers for what you  need can be found at the Beckett Oil burner site...typically .4 to 3 gallons per hour.  Good BSFC for a yanmar is .4 lbs/hp*hour  so 2 lbs/hour for 5hp.....so you might be coming in low at 5hp, seeing as 2lbs is .3 gallons.
There in lies the rub....my engine will not actually burn enough fuel to make it worth setting up a heat exchanger for a house. Perhaps heating a battery room would be more practical, or heating the wood shed...but unless I start burning enough fuel to operate an engine somewhere above the 5hp output range, it simply would be an auxiliary, which means I'd be burning wood anyhow.
Its a very interesting problem in itself, with most of the data available through the internet and ASHRAE. I think the problem becomes moot when you do a cost benefit analysis on the money spent versus heat input.
DF

[focodiesel]

Ahhh, let me clarify. Lets pick your 40% thermal efficiency....meaning 4/10ths of each gallon is converted from heat to work....the other 6/10s is wasted heat....of that wasted heat, 90% goes out the exhaust.

Yes I understand what you are saying, but I think you may be incorrect about your 90% statement, I have typically heard 2/3rds of combustion energy content is converted to heat, half conducts through the cylinder to the coolant and/or air , half goes out the exhaust, or as common rule of 1/3,1/3,1/3. I think it is important to clarify this.

But don't get hung up on the numbers....what is important is the idea....you have to ask yourself...at what percentage is it actually worth going after the fin heat? You intuitively know that most of the available waste heat is already in the exhaust gas...

No, that's where the confusion was, I did not intuitively think most of the heat was in exhaust gas, It is very reasonable to think there is a sizable amount of heat lost to conduction when you observe the size of radiators on liquid cooled engines.

So if there is equal heat lost to exhaust and conduction, It then comes down to what is easier to harness, In my eyes it is a liquid cooling system, once that has been built, than try and go after some of that heat in the exhaust.

Thermal efficiency is purely theoretical, AND saying 40% is converted to work, is not actually describing what work is being done...for example, blow-by is work, keeping the metal expanded due to heat is work, pumping lube oil is work, friction is work. None of these are of any value to your heating measurements. 

No, no...thermal efficiency can be very specifically described, calculated, and measured. it is not arbitrary or subjective. The "work" is power produced off of the crankshaft. I don't quite know what you mean by blow-by and keeping the metal expanded due to heat as being work, but as for pumping lube, yes it takes power but ultimately parasitic loads turn into heat, sound, or some other form of energy, and yes these "lost" loads are factored in to thermal efficiency mainly turning up as heat. Friction, again mainly turns into heat which is conducted away into the coolant/air.

The number that is valuable to you is the brake specific fuel consumption. Knowing how many pounds of fuel your engine uses per hour can be found using the BSFC chart for your engine.
Ball park numbers for what you  need can be found at the Beckett Oil burner site...typically .4 to 3 gallons per hour.  Good BSFC for a yanmar is .4 lbs/hp*hour  so 2 lbs/hour for 5hp.....so you might be coming in low at 5hp, seeing as 2lbs is .3 gallons.

Good to know, thanks I will look into that.

There in lies the rub....my engine will not actually burn enough fuel to make it worth setting up a heat exchanger for a house. Perhaps heating a battery room would be more practical, or heating the wood shed...but unless I start burning enough fuel to operate an engine somewhere above the 5hp output range, it simply would be an auxiliary, which means I'd be burning wood anyhow.
Its a very interesting problem in itself, with most of the data available through the internet and ASHRAE. I think the problem becomes moot when you do a cost benefit analysis on the money spent versus heat input.
DF

You may be right, your engine may not be ideal for heating your place, for me, 4 kw of heat is very attainable through waste heat capture. Another strategy I will employ is to have an electric water heater in series of my hydronic system, if there isn't enough heat output from the prime mover, and spare power capacity, you add the load of the heating element, further heating the water directly and loading up the engine which will in turn create more engine heat...

As for the cost benefit analysis, that has been covered earlier in this post. If we didn't factor in the enjoyment of creating, tinkering, and engineering this stuff and actually calculated the "labor" costs, none of us could justify this stuff. But that being said, there can also be huge savings, If I eliminate my utility bills, that is a substantial amount of money, and how can you put a price on freedom, or peace of mind?