diesel gensets

[turbodieselfreak]

Originally Posted By: Gary Allan
Yeah ..sawing your own legs out from under you for gain just doesn't make a whole lot of sense ..but no one wants to "float" someone else on their nickle either. So we are where we are.

Q: Do any of you water cooled diesel owners co-gen with the coolant and/or exchanging (or outright using) the exhaust?

On my long range (never probably ever to be completed) plans was to get a smaller water cooled diesel that I would vent the exhaust through my steam boiler ..recirc the coolant too. It's a low pressure system so it remains just above boiling. I just don't know if I can balance the thermal output with the heat demands ..or if I'll be way mismatched on the size of the diesel and therefore the gen set capacity.

If you can see what I'm struggling to communicate.

I'd hate to waste all that heat when I have a place to soak it up.
I didn't know tecumseh folded, wonder if I can get parts for my snowblower now. Am I dreaming, or did walmart once embrace a "made in the USA" theme on the products they carried? I also buy from the little guy for a few more bucks when possible. As for recovering waste heat from a genset, I think the most practical approach would be to harness exhaust heat into some form of liquid-based heat exchanger for room/garage heating, or maybe water heating, but I would think a boiler setup is asking too much from a residential unit. Commercial might be another story. Another approach might be to apply the otherwise wasted exhaust heat to a fabricated system for heating svo/wvo for fueling, as opposed to wasting generated power to heat and burn the stuff. Anyone have any input on the three cylinder mitsubishi/perkins/isuzu generators, before I drop a bunch of coin?

 

[boraticus]

A buddy of mine at camp has a 10kw Isuzu power plant. The engine has been fantastic but according to him, the generator end might be subject to bearing failure. Now, I don't know how much of his fears are real or imagined. He's never had a bearing go on his but he has acquaintances who own the same machine as his who have experienced extensive damage as a result of bearing failure. He also said that it wasn't an isolated case. According to him, others who own similar machines have had the same problem.

The generator on most of these these direct drive machines run one bearing only at the end opposite the engine mount. If properly aligned, they should last the life of the machine. I can't understand why the Isuzu generator would be hard on bearings. My Kubota has an Aircraft Appliance brushless alternator (no longer in business) and the bearing seems to be just fine after 6000 hours/27 years of time on it.

Either way, you might want to research that aspect.

Speaking of power plant issues, has anyone out there ever had a problem with the Yanmar three cylinder diesel? The same guy said that he knows of a couple people with Yanmar powered generators that had engine failure. I'm having trouble with that one.

I'd like to add that this information is from a stand up guy. He's a industrial tradesman and has very good mechanical knowledge.

 

[Cup of Joe]

Originally Posted By: marco246

T&N,

My Generac is identical to yours. I'm surprised to hear your engine will bog rather than trip one of the breakers. When I connect my genset to the house (inverter) via a cable connected to the three-prong locking 120V, 30 Amp AC plug, it runs fine until (inevitably) my wife finds a reason to switch on the 1/2 HP garbage disposal. Trips the far left breaker every time. You might want to check the appropriate breaker. I'd think your voltage regulator might be in danger. There are a couple of ways to adjust the genset's output: a screw on the master control board and the engine's governor. The former controls the voltage range. The latter the engine rpm, voltage, and herz. But if you've not adjusted them previously, they probably don't require it. Once you get it squared away, you should run it under load periodically. I do it monthly for an hour.

I really like the idea of hooking up a generator to a tractor's PTO. The downsides are you lose the use of the tractor and you usually have to run the tractor at or near 3000 rpm. Nevertheless, once my Generac plays out, it's an attractive option.

Cheers!


Well after some checking I have found 2 problems with my plan.

Problem #1 my Trane heat pump outside half is 4 ton 208/230V 30amp minimum, 50amp preferably.

Prolbem #2 the intake valve on the GN410 is more then twice the spec limit and the exhaust valve is extremely tight and was actually bouncing back open at TDC. This would explain my bog and power loss. It turns out I need the only allen wrench I do not already own to adjust the valves, strange how that happens.

I am going to adjust the valves back to spec but I am seriously going to have to look at my power needs.

 

[marco246]

T&N,

Regarding your power needs. Can you get along without the heat pump? Of course it gets pretty chilly there on the coast; have you considered a wood stove?

 

[boraticus]

I have two high efficiency air tight wood burning fire place inserts in my house. One on the main floor one in the basement. Each can handle 80 lbs. of wood. I've had my furnace go out in the middle of January and at 30 below zero F. for a few days. No problem.

The beauty of a wood burner is simplicity. Not much to go wrong if you keep a good supply of well dried wood and a clean chimney.

Same thing at camp. Wood is our only heat source out there. Nothing like sitting in a camp looking out the window at a sunny forty below day and having to open a window to cool things down a bit. yeah.... gotta love wood burners.

 

[turbodieselfreak]

Originally Posted By: boraticus
A buddy of mine at camp has a 10kw Isuzu power plant. The engine has been fantastic but according to him, the generator end might be subject to bearing failure. Now, I don't know how much of his fears are real or imagined. He's never had a bearing go on his but he has acquaintances who own the same machine as his who have experienced extensive damage as a result of bearing failure. He also said that it wasn't an isolated case. According to him, others who own similar machines have had the same problem.

The generator on most of these these direct drive machines run one bearing only at the end opposite the engine mount. If properly aligned, they should last the life of the machine. I can't understand why the Isuzu generator would be hard on bearings. My Kubota has an Aircraft Appliance brushless alternator (no longer in business) and the bearing seems to be just fine after 6000 hours/27 years of time on it.

Either way, you might want to research that aspect.

Speaking of power plant issues, has anyone out there ever had a problem with the Yanmar three cylinder diesel? The same guy said that he knows of a couple people with Yanmar powered generators that had engine failure. I'm having trouble with that one.

I'd like to add that this information is from a stand up guy. He's a industrial tradesman and has very good mechanical knowledge.


OK, thanks. Think I'll be going with the mitsu unit. It's the cheaper engine option, same generator otherwise. I've heard nothing but good about yanmar engines, but I don't have any personal experience of my own. You're probably only hearing one side of the story-I'm sure there's a lack of oil/maintenance issue there that the owners "forgot" to mention when cussin' about engine failure.

 

[Cup of Joe]

Originally Posted By: marco246
T&N,

Regarding your power needs. Can you get along without the heat pump? Of course it gets pretty chilly there on the coast; have you considered a wood stove?


The problem is less about providing heat and more focused on providing ac during outages. During hurricane season it is rather warm and very hummid which makes the house just unpleasant, to the point its cooler outside. I have used this same unit to power 3 window ac units during an extended outage, they made the smallest of differences. It does not get all that cold around here for very long, if we get 2 inches of snow the area comes to a hault. I have a fire place and a exorbitant number of heaters for this area I can use in a pinch to keep the house warm. Another problem I was facing was providing a shelter to keep the generator in while it was providing power during a storm.

It just hit me all this heat and ac talk, don't we seem a bit soft these days?

 

[turbodieselfreak]

Originally Posted By: TaterandNoodles
Originally Posted By: marco246
T&N,

Regarding your power needs. Can you get along without the heat pump? Of course it gets pretty chilly there on the coast; have you considered a wood stove?


The problem is less about providing heat and more focused on providing ac during outages. During hurricane season it is rather warm and very hummid which makes the house just unpleasant, to the point its cooler outside. I have used this same unit to power 3 window ac units during an extended outage, they made the smallest of differences. It does not get all that cold around here for very long, if we get 2 inches of snow the area comes to a hault. I have a fire place and a exorbitant number of heaters for this area I can use in a pinch to keep the house warm. Another problem I was facing was providing a shelter to keep the generator in while it was providing power during a storm.

It just hit me all this heat and ac talk, don't we seem a bit soft these days?
I think being soft is a relative term. I hate summer with a passion, anything over 75 degrees and I sweat like a pig, hence my need for a generator to power a/c. On the same note, cold weather doesn't bug me a bit, I don't even start to get cold until it's about ten degrees or less, and think those who do are "soft". If I live to retire, I'll be moving north, not south. You can keep florida. I am jealous of boraticus though, I'd love to have a wood burner-might have to look into it.

 

[boraticus]

Wood burners aren't for everyone. If you're an outdoors kind of guy, like to use a chain saw and not afraid of laborious work, a wood burner is great. Personally, I love to cut and stack fire wood. Don't do too much of it in town because there are only so many trees on my lot and I only process the trees that either die or get blown over in a storm. That's normally just a couple a year. I'm happy to burn gas until I need to use the wood burners. Occasionally though, during a real nasty, howling snow storm I'll put a fire on just for enjoyment. Sort of taunting the elements you might say....

 

[416Rigby]

Those Detroit 2-71 engines are bullet-proof, but they run loud. The blowers on them make most of the racket. The Delco genheads on those units are some of the toughest you'll ever find. They are 6-pole, 1200rpm units made mostly of cast-iron. The genhead alone weighs 1000 pounds! You won't find that level of quality on any modern machine.

 

[JTK]

Yep, you can definitely pick out a screaming banshee Detroit from quite a distance. Burrr...WuuuhhhhhhhhhhhAAAAAAAAAAAA!

Joel

 

[Gary Allan]

Quote:
I know that diesels like to run at a certain temperature. If you try to capture too much heat from the cooling system, the diesel might not run at it's optimum temperature preference.


Well, you wouldn't do it without some thought to that. If your boiler (if one had a boiler) is of low enough mass (water volume) then it's just a matter of run time before you need your radiator in addition to it. You can't transmit much of the energy in a steam system below 212F at ambient pressure ..so you should always be operating around that temp. For that matter, put it on the rad side of the engine. You would just be wasting the heat that the rad rejects.

The biggest challenge would be regulating your dwelling temp with full time steam production and not having it turn off so that the pressurized energy mass could collapse and return to the water to the boiler in condensate. There aren't too many residential (as in single dwelling) steam systems that are truly intended to be "at pressure" constantly. It's a wash tub effect in that you cycle the boiler just above and just below boiling so that the system just stays energized and de-energized enough to push enough heat to maintain setpoint. It's really efficient at really cold temps where you just cycle in really closely spaced pulses. When it's not that cold ..then the cycles spread out and the boiler drops too far below boiling ..requiring a lot of energy to bring it back to producing usable heat.

My system is, more or less, a "dead end" steam system that it requires that tidal action to work best. It's got drain points for the condensate to return to the boiler. Condensate and live steam don't coexist too well in the same conduit. That's the hammer you hear if you've ever experienced it.

In any event, it appears that no body is considering snagging the waste heat in the event of a power loss. I guess wood, if one indeed has a fireplace or wood stove, would serve their needs if heat is required.

It would be a no brainer for someone with an indoor pool.

 

[flacoman]

I could see this working with a two radiator system, not unlike a car's heater. One radiator outside,dumping heat not needed for the house, and one inside. A PID moving a valve could do the trick for control ,with the heat added into the air handler plenum.
my2c
Jorge

 

[wapacz]

why even bother with steam. Just set it up like a non steam based boiler. The thermostat would open a valve diverting some of the hot coolant to a secondary pump. That pump would push the hot coolant around the loop and back into the engine.

Not sure if you would need a secondary pump or not. It would really depend on if the internal pump was up for that task of moving the coolant through all that extra tubing.


The only real downside would be having to change coolant for the whole system every few years.

 

[flacoman]

I thought that's what I'd said ..

 

[Gary Allan]

You would use a heat exchanger with a secondary circulation pump. Not uncommon in marine and even something like a stationary sprinkler system. We had electric motors for our sprinkler system at the plant. Some insurance requirement (or so I imagine) had them install a V8 Caterpillar to drive the pump. It had a not all that big heat exchanger that was tapped to the fire system water tank.


The reason to make steam is that I have a steam system. This is a 100 year old house and refitting for a recirculating hot water system would cost more than the genset. It would be preferred, surely ..just for the simplicity.

The boggle, if you will, is not wasting anything. We ran into this at work. We bought $70k/month in electricity ..we also bought $70/month in NG to run the boilers. How much electricity could you produce with $70k of NG while producing enough heat to produce the 600k of steam you needed for plant operations. Cogen was a no brainer ..unfortunately we got bought and shut down before we could get the project going.

I can get electricity on interruptable service for $0.057 vs. $0.18x..so I can run the entire house on it at about a 50%+ discount after the added tidbits they throw in. The problem is the potential interruptions 4:30-7:00pm most week days during the 9months of the year and 1:00-9:00pm in the summer. They haven't interrupted that service for about 2 years due to having no place to sell the shifted demand on the grid. Now in the summer there would be no avoiding the waste heat, but in the winter there would be little sense of paying for either grid electricity to heat and back up electricity to run an oil fired steam boiler. I could go to all electric ..but it would be a shame to run a heat source and not use it where I can soak it up.

There's always complications in "you can't get there from here" in refitting in some situations.

So it's a matter of wasting money or wasting fuel. I'll work it out eventually.

If it was new construction I'd have heat loops put in everything ...the garage ..build a small green house ..have big storage tanks...

 

[Fordiesel69]

With central air plus other refrigerators and lights, you need 17KW surge to get the inductive loads (motors) started. If you undersize your generator, you will also use more fuel as it will be working too hard. Idealy you need to calculate.

 

[turbodieselfreak]

Originally Posted By: Fordiesel69
With central air plus other refrigerators and lights, you need 17KW surge to get the inductive loads (motors) started. If you undersize your generator, you will also use more fuel as it will be working too hard. Idealy you need to calculate.
You and I think alike, but understand I live in a very small house. My a/c is not one of the 3 ton units you see on mcmansions today, it is sized for the home. This place was built before anyone heard of JFK (my dad was a tyke), and thus only has 60 amp utility service, upgraded from fuses to breakers, with two hots and a neutral for 240v service. If my math is right, that means a maximum of 15000 watts or so from my power company before I trip the breakers, so I think a 17,000 watt unit is too large. Against the advice of boraticus, I will admit I purchased a kubota lowboy 11kw unit. I would've preferred an 1800 rpm machine myself, but I found one with zero hours on the meter at a steal due to cosmetic warehouse damage, which took more than a grand off the price-I couldn't resist for a deal like that. Guess I need you guys to chime in on transfer panels. Space is limited for a seperate transfer box, so I'm eyeballing one of the reliance panels with everything housed in one box. Have at it! ***Edited to add that I am happily unmarried

, so even with the a/c, there isn't much turned on except for a few lights and the tv, occasional laundry/microwave/compressor use excepted.

 

[turbodieselfreak]

Originally Posted By: boraticus
Wood burners aren't for everyone. If you're an outdoors kind of guy, like to use a chain saw and not afraid of laborious work, a wood burner is great. Personally, I love to cut and stack fire wood. Don't do too much of it in town because there are only so many trees on my lot and I only process the trees that either die or get blown over in a storm. That's normally just a couple a year. I'm happy to burn gas until I need to use the wood burners. Occasionally though, during a real nasty, howling snow storm I'll put a fire on just for enjoyment. Sort of taunting the elements you might say....
Love the outdoors and chainsaws, but to borrow from "a christmas story", my chainsaw is a chainsaw in theoretical sense-it was once made of iron, and has a chain to cut wood. The chainbrake quit working along with the chain oiler years ago, I should probably retire the thing. Taunting the elements is exactly what I had in mind, along with a lower gas bill, but I would have to buy my wood as I don't have enough trees on my current lot. Don't know how it is up your way, but the gas stations around here usually have a good deal on cords of wood, stacked between the pumps. Do they make four stroke saws? I've seen the four stroke trimmers, and am trying to consolidate my fuel storage. If I can narrow it down to diesel and straight unleaded, I can eliminate two stroke mix from the lineup.