thinking of exploring another option

[rcavictim]

What kind of fuel can a gas turbine be run on?

Jet-A, Jet-B, kerosene, pump diesel, home heating oil thinned with kerosene.

[Henry W]

For what we would use it for it would not be practical. The only way you will get any effency out of it the unit has to be ran at full 100% output at all times.

And if you think Diesel engines are expensive to rebuild. You will have to get a second mortgage to rebuild this puppy. And to run it you better have deep pockets.

Henry

[mbryner]

And deal with complaints from neighbors about the noise!

[BioHazard]

I like this "my generator is too big, what else can I hook it up to?" mentality. At this point turning hot to cold would be like turning lead to gold. I'm pretty sure I've seen waste oil fired commercial A/C units somewhere...maybe that would be a start.

Sometimes I wonder how the neighbors would react if I tried to sell excess heat/cooling/electricity to them. I'd love to be the neighborhood utility company. They already think I'm crazy enough though. I guess there are worse things a guy could do with his free time...

[TimSR2]

Random thoughts regarding this thread....     Of course we are all trying to reinvent the wheel here as others have stated. There are great old technology units on offer cheap.....Shipchief has noted the Onans from old motor homes, or pleasure craft are quite heavily built, and I must agree. If MCCK's could be found from fresh water environments and the heads planed a bit... they would be excellent dry gas engines. But Onan parts are expensive, even more than English Listers.

There are also the Honda watercooled motorhome sets....  Expensive, but  long lived. I've seen 5000 hour units in mobile kitchens that are still running well.

But do we really want to put all our eggs in one basket ? We want more heat than power here, right? Let's think like a power engineer for a minute .  In a large boiler installation if the 'call for heat' exceeds the supply they just bring another boiler online. So maybe two or three tiny engines could fill our requirements?  2 , 3, or 4 easily replaceable, drop in units, that can be swapped out quickly with spares.  Units that will synchronize their electrical production with each other automatically......

What about Honda EU1000's, or even EU2000's?  They are reasonably priced, standardized, can synchronize with each other, and are common as dirt. We only have to build a rack to mount them in,  and an air to air,  (this is off the shelf; it's called an air exchanger, my house has one)  or air to water heat exchange system. Easy tri fuel conversions available, also off the shelf.  We could have complete generator units stocked in case of failures, rotate the units for service, and to keep the hours distributed evenly .

Standardization, compact size, reliability, inverter built in..  90% of the engineering already done for us...   All we have to do is get over our water cooling bias  here  and engineer a heat exchanger solution to suit the base module.  My preference would be the EU1000.

[mobile_bob]

we certainly have kicked several idea's all over the parking lot with this discussion, however my original thought was more inline with
trying to agree to a common platform  that several folks could work with to develop the ancillary parts that are needed to make a cogen unit.

i guess the problem will always come down to choice of fuel, sizing issues, and personal preferences to some degree or other.

for me at least, i have been kicking this idea around for some time, while i may still build up a cogen power by a 4banger fueled by nat gas, it would probably
be more for the R&D experience, but more likely would only be used intermittently or during times of the year that it can be used to best effect.

at the end of the day, sticking with the s195 changfa and simply dual fueling it with nat gas makes probably more sense, would be far simpler and could seamlessly  change from diesel only operation to dual fuel without any changes to the engine.

the changfa is sized most appropriately for my end use, in that it could be ran over a longer period of the year at max efficiency than would a 4 cylinder driven
cogen,, at least from what i think at this time.

bob g

[wiebe]

Timsr2 wrote,What about Honda EU1000's, or even EU2000's?.

Wel just seen on youtube that the engine is a new type ,with timing belt ,no head to remove .
i am not so happy with them ,dont say that there not good but not for me.
The old engines are great gx/v series .but at the track [gokart]were had new honda,s 20 gxv200.
on the box was printed made in korea???.
Cheaper ok but after 2 jears of driving ,its not the same as made in japan .
Little more ware on them .

Greetings Wiebe.

[BioHazard]

What about Honda EU1000's, or even EU2000's?  They are reasonably priced, standardized, can synchronize with each other, and are common as dirt.

I guess you and I have a different idea of "reasonably priced".  While I really like the idea of multiple parallel generators, I don't think air cooled engines are a good choice. It's going to be a lot of work to catch that heat and I would have concerns about how efficient that is. One EU1000 cost more than a 4 cylinder engine would.

The other issue is that water cooled engines simply live longer, since they are much more thermally stable. What I'm thinking is that I'd want to entirely insulate my engine so that it never cools off, at least not for a few days, so it doesn't have to warm up again. The other thing about the EU generators is they run at pretty high RPMs for full output, more than 3600 I think. They are long lasting compared to, say, "Chonda" generators, I don't know if they're quite up this task though.

Then again, if you could get the air/air heat exchanger worked out, maybe you could simply get a $299 Harbor Freight generator with a 2 year unlimited hour warranty, and plan on buying a new one every two years...

[BioHazard]

we certainly have kicked several idea's all over the parking lot with this discussion, however my original thought was more inline with
trying to agree to a common platform  that several folks could work with to develop the ancillary parts that are needed to make a cogen unit.

i guess the problem will always come down to choice of fuel, sizing issues, and personal preferences to some degree or other.

Certainly we could share a lot of ancillary parts between different engines - specifically stuff like carburetors and governors. Even though we're all interested in different engines, we're usually all looking for roughly the same amount of HP...

[BioHazard]

This could be an option to look at for air conditioning...
http://www.econoheat.com/waste-oil-equipment/air-conditioners/
I wonder how hard it would be to simply replace the oil burner with an exhaust pipe? I bet they aren't cheap...though the oil burner part is probably the most expensive.

[BioHazard]

How about this - what if you used a manual transmission with overdrive to drive your generator? (engine/trans come in pairs cheap) This way the engine would only run ~1400 RPM - BUT - you could also easily use the stock cruise control setup for a governor! No?

How (in)efficient would a small manual trans be in overdrive vs a belt drive? And, would a normal cruise control setup have tight enough tolerances to keep a generator at the right speed? "Old car parts" are cheap and plentiful. "Generator parts" are custom and expensive.

(seriously, it's 4AM, this cogen idea IS keeping me up at night!)

[BioHazard]

One last thought before I go to bed.  

The GM Ecotec 2.2L engine.
Available "off the shelf" here:
http://www.jegs.com/i/GM-Performance/809/19156263/10002/-1?parentProductId=956489

A reputation for performance, durability and adaptability has made the Ecotec the "small-block" of four-cylinder engines.

(since it's a GM performance parts crate engine I assume all parts are available through any GM dealer)
They are probably available from your local junkyard significantly cheaper, I haven't checked yet.

Better yet, this engine comes stock at 10:1 compression and more stroke than bore!
http://en.wikipedia.org/wiki/GM_Family_II_engine#Displacement:_2.2_litre

Unlike its notably harsh predecessor, the L61 was designed for smoothness. Dual in-block balance shafts were integral to the design, and all accessories were mounted directly to the engine block to reduce vibration.

[rl71459]

I like the Idea of a self regulating (kw sizing) system.

Somewhat like Bio mentioned with the transmission to set the rpm... I do not think using a transmission of any type (Mechanical) will suffice, due to losses. Although if it was acceptable to do, I feel one could use an Automatic Trans with the converter "Locked" and by doing so a control could shift the unit as needed to attain the desired load matching. I still think the mechanical inefficiency would still kill the concept.

What if we build a system using an engine sized for the highest expected "Typical" load and direct couple it to a generatoring device (The optimal type for the job) that can output useable power from IDLE to MAX RPM. Then Via Electronics (Inverters, Rectifiers, Regulators, Controllers...) we throttle (size) the unit to match the demand. By using this approach we could also have engine driven AC when desired.

The engine could be Multifueled if so desired in your favorite flavor's to suit the situation at hand. e.g.  Woodgas, Gasoline. or Diesel, Waste whatever, Woodgas, Nat or Pro Fumigated/Ratioing.

O.K. I will quit rambling on now... Sorry
Rob

[Chris]

There is a product out their that i saw for sail boats that had a variable speed belt drive system hooked up that kept the generator at 60 hertz.
I tried to find it, but can't seem to locate it.
There are many variable speed belt drive systems that adjust by cranking a handle.
What would be cool was if a system could be developed that would adjust the belts to suite the load. Small load and the engine just idles along.
Increase the load and the engine speeeds up, the belts adjust to keeps 60 hertz on the gen.
Sort of like and mechanical inverter generator.

Chris

[Chris]

Just a thought on engine options for natural/propane gas.
How about forklift engines. There must be a bunch of those around. Propane and probably about the right size.
I see many of them running aroud wharehouses etc.