new project r175 microcogen

[mobile_bob]

been a long time since i posted any project progress so i thought it about time to do so

the project i have in mind is a small cogen more inline with the needs of my place here in town.

the 195 based trigen is just a bit oversized for what i am thinking my needs are, and a smaller unit would be easier physically for me to build and probably easier to do some serious R&D with. i already have some good numbers on the 195 unit so having the ability to do the same testing on a smaller unit might be interesting and informative.

i have a pair of R175 changfa (water cooled ~4.4kw diesel) so my thinking is to use one of them and build up a unit to charge a 48volt bank and also drive a cold plate refrigeration system (alternating between the two)

the biggest drawback to the smaller changfa is it is a crank start engine only, and would need fitting with some sort of starter system.

what i came up with was using a 12volt liftgate motor which i have on hand and marry it to a A/C clutch so that it can be used to spin the motor over and then disengage and just freewheel while the engine is running.  so i picked up a leaking sanden and removed the 6groove pulley and cast iron nose housing and the rest of the clutch pack and input/drive shaft.  didn't take too much to make a nice little clutched starter out of the misc parts.

originally i had thought of using one of those ESC modules that the RC guys use to convert alternators to motors, thinking i would switch from start to generate mode with the microcontroller/autostart system i have on hand.  however i figure i need to do more study on that topic before investing in parts that likely would not work well with my ignorance of how and what i really need at this point... so maybe later we can go there.

anyway, i started the frame rails and want the unit to be very compact, and have figured a way of using one 6groove micro/serp belt to connect the starter, the 48volt alternator, a sanden or equivalent a/c compressor and a tensioner idler unit.

i also plan on removing the water tank, install a block off plate, tstat to 195, bosch water pump to move the coolant to the hot water storage exchanger and also through the exhaust heat exchanger.  the removal of the fuel and water tank effectively reduces the physical size about 40% or more, and allows me access to mounting holes for the accessories to be driven.

what i am really keen to test and find out is the following

1.  how effective and efficient can i make this thing into an inverter/generator, using the battery bank more for surge capacity than for storage

2. how well a refer system can be driven with this unit

3. because i have ready access to nat/gas, how well will the 175 operated and how efficient in dual fuel mode

4. this will also be a really good test bed for the automation/control system, with all sorts of things to learn along the way.

5. i also want to rework the oil system of the little changfa to include full flow filtration as well as a bypass filter... i think it can be done and the result ought to be dramatically increased lifespan especially if the dual fuel thing with nat/gas can become a reality.

i promise to start posting some pictures, but i must also admit this project will likely take quite some time as my physical health now limits me to not much over an hour or two every other day or so... this last week i have been unable to do anything as my pain levels have escalated due to inflammation of several bulged disc's leaving my left arm feeling like i have severely racked my funny bone and my left leg aching horribly.

its driving me crazy that i can't do what i once was able to do, but oh well, my hope is a much smaller unit might be easier for me to manage and fit my end need better anyway.

not much to show yet, but i will get out and start posting some pic's

bob g   

[glort]

Hi Bob,

First let me say I understand your difficulties in not being able to work as you did. I have diabetes and it has sure killed my stamina. Like you, some days half an hour's work is all I can manage. Sometimes I get fed up and try to keep going but all that achieves is me being unable to do much more than walk for the next 3 days.
There is nothing more frustrating than looking at what you want to do and not being able to do it.
I guess only those of us in that boat would understand.

WIth the Dual Fuel thing, are you looking to fumigate the engine with gas, IE, feed a supply of gas into the engine while it is running on diesel to offset the diesel use or are you going to try running it on Nat gas alone?

I have been into the veg oil thing a long time now and my little 165 As well as my vertical China engines run real happy on straight, unheated veg. It might be something to look at if you are interested in keeping your running costs right down.

I'll be interested to see how you go about silencing the engine. Mine is a noisy little thing although I note induction noise is as significant as exhaust ( although harder to quieten) and the 3rd element is the mechanical clatter.
For mine I'm looking at adapting a car air cleaner as the original allows a lot of noise and I also got an induction box which is just a hollow air cleaner like thing which is empty and non tuned as it were.  Apparently it's original job was to take the induction noise out of the vehicle it was on although I'm not sure if it went before or after the air cleaner box.  Probably doesn't matter a lot.

I also got an aircon a while back with a view to using the clutch for a starter for my lister. I currently use a serpentine belt on the flywheel to a pulley I welded onto a starter motor. It works real well but is very redneck as once the engine is running I have to flick the belt off to prevent the starter bearings literally smoking due to the excessive speed. Like you the plan was to use the clutch as an idle and just wire it in so it locks when the starter is activated.  The things seems amazingly strong but I suppose they have to be  when they slam a compressor into motion.

I have also thought of using a car aircon system for my house but haven't got around to much with that yet. Getting the evaporators out is such a pain on most vehicles and I haven't been that motivated as yet.

I hope it all comes together for you well and I certainly look forward to seeing what you come up with.
No doubt we will all learn a lot from your project.   

[mobile_bob]

update

got the thing assembled to the point to where it can be started and ran long enough to test some speeds

the engine runs remarkably well and and acceptably smoothly at 1400rpm, it however does not like 1300rpm but seems to do quite well at between 1000-1200rpm which is a real surprise... not sure i need that low of a speed operation, but nice to know it can do this without sounding like it is beating itself to death.

the starter i made up out of a lift gate motor and an a/c clutch does a very good job of starting the engine, provided i either allow the motor to spin up before engaging the clutch or if i make sure the engine is not approaching compression stroke.

because this setup will be controlled with my engine controller system, i can provide a stepped timing function to allow enough milliseconds to spin up before engaging the clutch, and/or...

i can engage both at the same time, for a few milliseconds to get the flywheel to approach compression, release and allow it to rock back, and arrest its position with full fielding the alternator for a few milliseconds... this will position the engine far enough off of compression stroke to allow a startup without problems.

not that i am having problems as it is, but having full control via microcontroller of all aspects of the unit allows me to do things that i cannot do any other way, at least not as easily.

still owe the forum some pictures and will try to post some tomorrow

bob g

[mobile_bob]

got a few more minor tweaks out of the way, mainly things like adjusting the length of spacers and such to get the belt to near perfect alignment... close enough for the girls i run with anyway.

yesterday i pushed myself a bit too far physically and really paid the price last night, just hard to accept that things are likely not going to get better over time, but steadily worse.  oh well, such is life.

i scaled down my design for the exhaust heat exchanger that worked so well on the s195, hopefully it scales well enough to learn things like "can it be scaled to work with a 6/1"?

set out to find the bits and pieces to make the darn thing, and had to fabricate things that i could have just picked up off the shelf in tacoma... sadly  there is no shelf here to pick from. if i don't have it, or can't make it, i either have to travel 60 miles for a 50/50 chance it would have to be ordered anyway... that is always something that pisses a guy off.

anyway, at the end of the day i got the heat exchanger built and finished mounting it today.

fabricated a new exhaust header and intake header to make stuff fit, and fabricated a new thermostat riser housing and welded it to the block off plate...

next will be fitting the bosch auxiliary water pump to cool the engine and remove the heat from the exhaust exchanger, getting closer and closer.

my hope is to have it together enough to start fuel consumption testing, heat recovery rates, and power production from this unit by mid next week.

i really like working with a smaller engine, something that is about a quarter the finished weight of the 195 trigen makes life much easier for me to work around.  i am thinking the finished weight should come in at less than 225 lbs, something easily managed with my cherry picker.

more to come...

bob g

[mobile_bob]

finally got around to taking a couple of pictures of the latest project

try not to be too critical of my build quality, my back is just not very cooperative when it comes to standing for any length of time, and it only gets worse when it comes to welding.

fwiw

the A/C compressor is mounted down on the right side, the liftgate motor with A/C clutch is the starter motor (lower left)  the upper right is the leece neville to be tested in 48volt nominal operation,  the rest are idlers and tensioners... all driven with a 6groove belt.

all driven and drive components are over 180 degree belt contact, and the tensioner is made for an 8 groove belt on a c15 cat engine (an extra i had laying around that needs new brgs installed in it, it squeals a bit).

the silver canister looking thing is the exhaust heat exchanger, the silver is a section of 4inch galvanized stove pipe which is used to cover the exchanger and contain the insulation pack.

the intake manifold i made and is quite a long runner for this engine, we shall see if that has any effect, my goal was to just get it up out of the way... the air cleaner is off a B&S 16hp horizontal engine that i cleaned up and reused. the exhaust manifold is also a fabricated piece using the same steel pipe weld fittings (i really like those)

the t/stat housing is a dodge neon (2000-2005) and i used the dodge seal ring with another centered/standard type t/stat 195degree F.

the frame albeit a bit light for my liking has two pipes used as torque tubes welded to the outer ends of the frame, these to control twist and keep the rails inline with one another.  everything is more or less tack welded together, i have to take it all apart and finish the welding once i get more gas for my mig.

well that's the basics for now

just a side note, at about 1600rpm there is no gear clatter, and no diesel knock?  i can have a conversation with another person while standing over the running engine... of course i expect more knock as load is applied, but heck this thing is a fraction of the noise of a 195!  my target was to operate at 1400rpm for refrigeration compressor drive, but now am considering going up to 1600rpm because of the lower noise.

more later
bob g

[veggie]

Looking good !
That's quite a belt arrangement you have there !
A lot of thought goes into that type of setup long before any steel is cut.

keep the pics coming...

veggie

[Henry W]

Very nice Bob, You accomplished a lot in the amount of time spent.

I just got off of my but this morning and starting to work on my genset once again. I hope to stay motivated and come up with something.

Henry

[EBI-WPO]

Nice work Bob.
i haven't really had much time to do much but check in briefly on the site lately, work has kept me hopping. Good to see you're still at it, even at a reduced pace, always look forward to seeing/hearing about your work. See you still have your 55.

Any chance of sharing your Heat-X design? Please?

Anyway, keep at it, always good to see your posts.

Terry