new member start o matic chp

[sababennie]

Goodday folks,
I have noticed that running big engines is not so populair anymore. Maybe i can start it up a little.
I am busy with making my own chp for about three years now. I bought from ebay england a start o matic 6-1 from a scrap dealer. I live in the middle city center of an old town in a very old house (300 years) and I have the engine indoors.
Very fast threw the developments, my bigest problems were exhaust noise and fibrations and just general noise.  I bought a second hand freezing cell covered the walls with rockfon ceeling pannels and you can not tell if the engine is running. The exhaust I made a labyrinth exhaust box with the same rockwhool pannels and there is only smoke from the exhaust. No sound at all.
I am left with one huge problem, vibrations.
I have a 5/12 meter man cave on ground floor and a few years ago I got a new concrete foor with floor heating, due to it beeing an old house I could not dig deep enough to poor in the concrete I wanted so I am stuck with 10/12cm concrete. and you can feel the engine running. And in the living room you can hear the cutlery vibrating along (one floor up).
I have been experimenting a lot with rubber tyles, engine mounts. Extra weight . Its sort of excaptible but far from perfect.
I sort of made a decision to penetrate my new concrete floor with four concrete studs and put a serious heavy base on top but I am afraid that the thick clay underneath my house will transport the fibrations non the less.
It has been like that all the time, one step forward two steps back. But with this heavy engine and parts every idea takes a few days to try.


I have been threw all the balancing I could find on internet, beeing it an original lister with the extreme heavy flywheels is there any inprovement to gain you think. I think tommorow I will give it a testrun with normal 6-1 flywheels to see if it improves.

Now the engine is on a start o matic base and that is mounted on a very stiff steel base about two meters long 1 meter wide. Each corner of the base is resting on approx 20cm2 rubber playground tyle. This gave the best result i could get. Engine sorts of floats above the "rigid"concrete. At full load after one hour its almost acceptable but when you get two floors up in the bathroom your toothbrush is slightly rathling in the glass.

I could seriously need some good advice.

Kind regards

Bernhard

[BruceM]

Adding weight to the counterbalance in 2 oz per wheel increments (4 oz total) would be the first place to start, since in this case you may be better off somewhat overbalanced if the vibration being transmitted through the house is vertical, and sideways movement may not couple to the house as much.  Lighter flywheels would be a waste of time, I think.  Search for 38AC's method of matching the flywheels if that doesn't do the trick.  Also search for messages here on using a cell phone accelerometer.

It's not clear from your message- is the CS mounted on your ground floor concrete?  Does "ground floor" mean basement or below grade?

My experience was that large rubber pads aren't helpful, but tuning the flywheel balance is.  A true soft mount might be needed for your application which requires some more serious engineering as the mounts must have sufficient softness and movement to absorb the vibration.

[sababennie]

Thank you for your answer I will have a go at adding lead to the heavy side of the flywheel. Seems like a good plan. I already tried the telephone app, but since I got the engine floating on rubber you have an idea of the readouts you get.
Groundfloor in my case means street level. it's on 4 pads of aprox 20/20 cm (10cm thick) of rubber and then on the concrete floor it's trial and error the best result until now. If i add more rubber you get like a frequency resonance it amplifies itself. If I reduce rubber my house will collapse within the year.
Your idea to find the best compromise with moving up and down and sideways is a good plan. I'll give it a go and feed back the result.
Alternative that I have to drill holes in my new floor and trying to avoid the heating coils inside. And what will happen if you transport these thuds into the clay.

regards

Bernhard

[sababennie]

Once again thank you,
It's not perfect yet but it allready made some significant changes,  the scale went missing so I did some gues work with the lead. I think I am on the right track.

For people who are interested, I have a 800liter boiler connected (it looked more like 400 on the picture....) two way valve to central heating. I feed back power to the grid with a three fase motor. It's a two speed dahlander motor so I also use it for starting. Been pretty busy with arduino, temperature sensors, flow sensors. Electrical current sensors. Automation in general.
I use a nice size pipe cooler to soak up exhaust heat, big enough to be condensing but if the return temperature of my boiler starts rising he starts condensing further on in the exhaust, still need to work on that.
Because the whole set is mounted in a cooling cell I have to use an exhaust fan to keep the temperature down. It's a waste of heat somewhere in the future need to find a way to recover this heat.
Fiddling with old vedgetable is not really my thing so  started with mixing propane/butane mix from mobile bottles 12kg. Works fine, I have a natural gas connection think I will make a connection to the engine.

Thats it for now


Kind regards

Bernhard

[BruceM]

Glad you had some good improvement already.  You can use your feet and your house as your vibration sensor if you have time and patience to keep fiddling with the balance.  My whole engine shed was shaking before I spent an afternoon on balancing. I got it to where a cup of water will sit on the valve cover and just ripple the water.  You might also look at some articles on the Mr X method, which should work nicely with your rubber under the frame.

Carlb has a nice natural gas fed Listeroid 6/1 setup.  Perhaps you can find his old posts on it.

I'd love to see your automation work when you have time.  My 6/1 Listeroid is has remote start, control by Picaxe (a few years before the Arduino). Full manual operation is still supported, with the automation turned off. 

Best Wishes,
Bruce
Concho, Arizona

[sababennie]

Goodday,

I am pretty happy with the new situation, when it's on working temperature i think the rubber pads soften and it's really unnoticable in the house.
About showing of my automation, I first want to have everything finished before I put anything on Youtube.
I can tell you about my explorations though. I have 5 DS18B20b  temp sensors for coolingwater, nice thing about these sensors is that each has his own adress all on one cable. I have a thermocouple in the exhaust.
I use amp/power measuring from openenergy.com that sell a shield for the arduino,( youtube .. 1r5XoiM_s_M...). took me a tremendous amount of time to get this working.
Had an inductive pickup on the flywheel for rpm but since there are only three gaps in the flywheel the resolution was to small to get an accurate reading, now busy with a hall pick up and want to put 60 small neodium magnets on the flywheel, did a dry test and it seemed to be working. For automatic starting it's important to kick in the breaker at the right rpm otherwise I pop the thermal relay.
I had thoughts about installing a watermist system, cheap karcher HP cleaner watervalve two relays and a fire detector. Also was busy with fueltank level, pingers in the tank.
Still enough to keep me busy.

In general I still don't see why CHP is not more popular, the big grean beast in your gardenshed scaring people i can understand but I think it must be really feasable to have a small natural gas engine running a chp extremely economical.

Oh about my location, think about windmills and tullips.

regards

Bernhard

[BruceM]

Sounds like you're going to have a very nice system regarding instrumentation/automation!

[sababennie]

like to wish everybody nice hollidays and all the best for the new year.
haven't done much until the last posting except running the engine, and consume the heat. Am looking for heat recovery system to extract the heat from the ventilation air. I am now blowing out 40/50 degr celcius air to outside air to keep the engine space sort of cool. Waste of heat of course. My "automation" still has some glitches. The automatic starting and stopping works but after a while decides its going to live its own live. So everything is still manual .
For the rest nothing new. Still just wondering why not more people are in to this, oil prices will go up eventually...
Started adding natural gas to the inlet, Works fine.

regards

Bernhard