1115 thermal cyphon cooling question

[glort]

I have a little Air cooled Horozontal China Diesel and it's by far my favourite engine, even over the lister clone.

The thing is rated at 3.5 HP but leaves the 6 HP verticals and a Hatz rated at 5 HP for dead.  I can drop way more on my generator with that engine than any other before it even looks like smoking.  Haven't tested it on the Roid, still have to get that thing to run like an engine not a Jackhammer before I hook it up to anything.

Only horozontal I have but it sure has endeared the type to me.

[dmarkh]

Well, I hooked it up to the house Sunday morning. I haven't got my permanent hookup in place yet so I just reinstalled my original 30 amp inlet plug I previously had for my little 7500KW generator before the mains panel was replaced. The 30 amp breaker I used was NOT braided wire friendly and I could not get all the wire in the breaker.

With the original panel, breaker, and 30 amp inlet, I was able to run my AC with the 7500KW gen. The AC is on the other side of the house too. I could even run a few lights and the AC would cycle without too much hurt on the gen. It certainly felt it but kept right on going.

The ST-10 would not start the AC. I did have a few lights on. 2 frigges and a deep freeze. I was only drawing about 15 amps at the time. The 1115 spit smoke for about 5 seconds until the AC gave up. I sure expected it to be able to handle the AC even on the other side of the house. The AC is a 2.5 ton. It is only 4 years old. So it's fairly modern. The compressor is a single stage but the air handler is a 3 stage. The compressor starts then the blower steps through it's speeds about 30 seconds per stage.

I hope the problem is just that inlet breaker connection. Shouldn't this thing be able to handle this AC fairly easily? Again my 7500KW gen seemed to be able to, but I did not hook it to the same inlet on Sunday to verify. May I'll have to. Or maybe I'll just go get a proper breaker.

Back on subject, While I had it on the house, AC breaker off, It certainly does get hotter quicker with a load. Without blocking off the rad it will easily reach the desired temps. My fans were not cycling at the right temps though. On at 211 and off at 193. And every time they shut off the temp even went down further. So far down the TS would close. So I thought I would try removing the thermal compound between the block and temp switch. So I shut it down and cleaned it all off and fired it back up. Then, for the first time for me, this thing was NOT going to siphon. At about 210d I felt the need to shut it down. I'm pretty sure the TS was open but not positive.

Could this be because I have no hole drilled in the TS?

Mark

[Ronmar]

Unless the thermostat is stuck, it should thermosiphon...  The laws of physics are not that easilly circumvented:)  You must have a temp difference to thermosyphon, heat input on the engine side to lower the density and cause the fluid to rise AND cooling on the radiator side to increase the density to cause that fluid to want to fall.  Think of it like a continous loop of rope run up and over a pully.  Helium ballons on one side that shift to water balloons on the other keep the rope in motion  IF the rad was heat saturated(helium baloons on both sides), that might delay the flow startup untill things warm/cool.

Are you sure the water levels are good, particularly in the upper rad tank?  The upper pipe into the rad must be completely submerged...

[playdiesel]

My 1115 would at times try to siphon backwards and other times not go either way and just sit there and get hot. Drove me crazy until I sat and thought about it a bit. Then l I extended the rerun line down below the plate about 2" and all those troubles ended.
I dont run a thermostat and I just let the thermostat on the fan control tend to the engine temps. It will come up to temp and turn the fan on in about 10-15 minutes depending on load and ambient temp.  My connections are further apart on the plate than yours being more or less in the corners with the hot exit pipe being the one closest to the head.  Both of my ST heads will deliver quite a bit over rated capacity for a second or two to start motor loads.  Mine is a 15KW but it effortlessly starts our whole house A/C  when everything else the ole woman can turn on is running. We don't have to mange loads at all when on the generator but stove and water heater are gas.

[Ronmar]

Oh crap, I forgot what type engine we were dealing with here...  Playdiesel brings up an excellent point.  How far down into the cylinder does your return pipe extend?  They need to be at different levels, the greater the distance the return pipe extends down into the cylinder the better.  If they are near the same height, the hot water dosn't know which one to go up.  With things warm, turning on the radiator fan to cool the downside might help to kickstart the flow.

If your little 7.5KW set starts your AC, the ST-10 sure as hell should.  Because of their spinning mass, the ST's usually excell at getting large inductive loads running.  What voltage are you running out of the ST, and also how are you setting the frequency/RPM?  Like you mentioned if you are having connection issues, a large slug of current pulled across a poor connection can cause a real voltage drop.  Does your AC have a junction box where you can sample the voltage?  If you can monitor it at the AC you can compare the starting voltage drop between commercial, the 7.5 and the ST-10.  This might shed some light on the situation.

[dmarkh]

Oh crap, I forgot what type engine we were dealing with here...  Playdiesel brings up an excellent point.  How far down into the cylinder does your return pipe extend?  They need to be at different levels, the greater the distance the return pipe extends down into the cylinder the better.  If they are near the same height, the hot water dosn't know which one to go up.  With things warm, turning on the radiator fan to cool the downside might help to kickstart the flow.

There was plenty of water at the top of the rad. Not a good picture but this is what I saw when I took it apart shortly after bringing it home. The return pipe extends down 4-5 inches. Can't tell by the pic but It still has the heat shrink around it too. I'm pretty sure this plate was purchased from UtterPower by the original owner. Actually I suspect the original owner frequented this forum too. That's another subject though. I actually did turn on the fans to see if it would help. Maybe I just panicked when I saw the 215 degree temp with no siphon and just didn't give it enough time? The missing "hole" in the TS was my first thought? Seems like a manual valve of some sort might be better than a TS? Maybe even what playdiesel does and run without one all together. At least one would know the state of things. 

http://s1273.photobucket.com/user/dmarkh/media/DSC03635_zps91763d6c.jpg.html?sort=2&o=74

If your little 7.5KW set starts your AC, the ST-10 sure as hell should.  Because of their spinning mass, the ST's usually excell at getting large inductive loads running.  What voltage are you running out of the ST, and also how are you setting the frequency/RPM?  Like you mentioned if you are having connection issues, a large slug of current pulled across a poor connection can cause a real voltage drop.  Does your AC have a junction box where you can sample the voltage?  If you can monitor it at the AC you can compare the starting voltage drop between commercial, the 7.5 and the ST-10.  This might shed some light on the situation.

I set the engine speed so that I'm at 60-62 Hz. Then I adjust the pot, that was originally on the dog house, so that the voltage is 240-245. I have not yet verified whether or not I have a balancing issue between the 2 120 legs. I was only drawing around 15 amps when the AC tried to start. I suppose if one leg was drawing that 15 amps, it could cause this? I'll have to verify all this this weekend. I installed 3 donuts in the internal breaker box so I could monitor the total amps and amps from each 120 leg.

I have a junction box out by the compressor. I will have to do some trouble shooting this weekend. First thing will be to insure that connection is proper. Just looking at it gives me the creeps. I actually have an additional 30 amp inlet out by the compressor. I put it there just in case the 7.5 couldn't start it from the other side of the house.

While I had this thing down, I removed the dog house and put a "western" style 70 amp rectifier in. Of coarse you know that that process required the splicing of the wires coming out of the head to reach my internal breaker box. I paid special attention there. I used copper barrel crimps, then soldered them using a small torch. So my fingers are crossed that this isn't my problem.

Thanks again guys for the input. It will be Saturday before I go further. It's to be a busy week.

Mark

[playdiesel]

It should work OK with a thermostat once you get things sorted out, I say that only because a lot of guys have run them and are happy with the set up, not from any personal experience 

My set up didn't happen by the initial thoughts and design, actually the first go was a joke .  It kinda evolved into something that works for me as I think most do?  I am not off grid, the 1115/15KW set is stand by at this time but when I retire and am broke but have lots of time on my hands the plan is to run some waste /recycled fuels.  One of the things I found early on was the 1115 was not the smoothest in operation and tended to shake apart what was attached to it and for that matter what it was attached to.  I figured that a thermostat was easy enough added if and when it proved necessary, if it wasn't necessary it was one less thing to be shaken apart. As it exists now my set up warms quickly enough (for me) without a 'stat and very nicely regulates itself.  If the temps are under 60 and the wife doesn't have the entire house turned on the fan never runs and the block temps run 180-200. On hot days or when the A/C is on it needs the fan and then the temp a bit hotter and spread is both a bit wider.

A somewhat fuzzy pic of my setup as it exists today.

[dmarkh]

no reason for the system to not be able to stand up to at least 10psi

if the gskt is leaking under very little pressure, replace it with a good gskt and double check
things like liner protrusion.

my testing has been on the 195's admittedly, however i can see no reason why an 1115 would be any different in its capability.

i run a 7lb cap in order to run between 205 and 214F without issues.

the cylinder liner orings can surely handle the pressure in my opinion.

as for thermosiphon systems, i am not sure having a pressurized system would have a detrimental effect on its operation.

thermosiphon certainly has its place, however the 1115 really lends itself to a radiator/pressurized system and a coolant pump.  efficiency goes up with coolant temperature in my experience, and once you get over about 195 relying on thermosyphon can be problematic, at least in my opinion.

another point worth mentioning, the engine being of horizontal design, makes it a bit more difficult to get sufficient circulation via thermosiphon through the cylinder head, the cyl head temps will be quite a bit higher than that which is measured in the main part of the block.  it is not unusual to see temperatures in the 240d F range in the cylinder head. at these temperatures air bubbles are likely to form in copious amounts, these bubbles can cause issue with thermosiphoning.  this is the primary reason the engine's are rated so conservatively because you can't get much more power out with an antiquated cooling system design (read that thermosiphon)

as an example the 195 is rated at ~12hp continuous, with thermosiphon and you can push it to ~13 for a 1 hour rating owing to the need to add copious amounts of makeup water. however with an inclosed system the same engine has no problem developing 15+ hp continuous without any issues save for replacement of the cheap oem head gasket with one supplied by the "gaskets to go" guy.

the efficiency is significantly improved at the higher temperatures and higher output levels.

back to bed, been sick for over a week now and its  getting really old!

bob g

Hi Bob. Hope your feeling better. I have been reading and re-reading this and another post by you at:

http://www.microcogen.info/index.php?topic=3159.msg35409#msg35409

I'm more and more intrigued by this setup. And from what I can tell all I would need is the water pump you describe in the above link, a new "less than 10lb" radiator cap, block off the cool side port on my plate, and a little plumbing. Everything else required is already installed on this unit. My rad fans are driven by a 12 volt power supply. The temp sensor switch is an AC switch driving an AC to AC relay that turns on the power supply. I would have to drive the pump from the battery and not that power supply so I would have to also get the battery charger installed, which I was going to do anyway.

I just have a couple of questions.

Would you hesitate doing this without changing the head gasket first?

When the TS is not opened and the pump is running, what happens? Does there need to be some sort of bypass plumbed in? Do you still drill a hole in the TS?

Thanks
Mark

[dmarkh]

It should work OK with a thermostat once you get things sorted out, I say that only because a lot of guys have run them and are happy with the set up, not from any personal experience 

My set up didn't happen by the initial thoughts and design, actually the first go was a joke .  It kinda evolved into something that works for me as I think most do?  I am not off grid, the 1115/15KW set is stand by at this time but when I retire and am broke but have lots of time on my hands the plan is to run some waste /recycled fuels.  One of the things I found early on was the 1115 was not the smoothest in operation and tended to shake apart what was attached to it and for that matter what it was attached to.  I figured that a thermostat was easy enough added if and when it proved necessary, if it wasn't necessary it was one less thing to be shaken apart. As it exists now my set up warms quickly enough (for me) without a 'stat and very nicely regulates itself.  If the temps are under 60 and the wife doesn't have the entire house turned on the fan never runs and the block temps run 180-200. On hot days or when the A/C is on it needs the fan and then the temp a bit hotter and spread is both a bit wider.

A somewhat fuzzy pic of my setup as it exists today.

The original owner of this thing set it up for WVO. When I picked it up he had 20 5 gallon cans full of WVO setting in his garage. The wife wouldn't let me take them. The fuel filter has a heater built in but a found no electrical connection to it.

http://s1273.photobucket.com/user/dmarkh/media/DSC03562_zpse2074c53.jpg.html?sort=2&o=7

So far I've found that the trailer this sits on seems to help but yes that thing is a shaker. I've also found that my little 7.5KW is louder than the 1115. That of coarse is running the 1115 with the doors closed and exhaust fan running. The gaps in the trailer bed allow for quite a bit of air flow so I can and will run it with the doors closed. The door in front of the st-10 remains cracked though. When I open all the doors you can no longer even hear the 7.5 running right next to it.

I had seen pics of your setup before while searching for info. nice..

Mark

[buickanddeere]

Hold it right there dude. running the exhaust into the shack instead of piping the exhaust out? Sorry but I just have to ask why would you do something so incredibly stupid ?

[dmarkh]

Hold it right there dude. running the exhaust into the shack instead of piping the exhaust out? Sorry but I just have to ask why would you do something so incredibly stupid ?

My engine exhaust runs out the bottom of the trailer into an automotive tail pipe/muffler. I was talking about exhausting the air inside the enclosure with an exhaust fan. Sorry for the confusion.

mark

[mobile_bob]

day 13 and counting of this dreadful "hooteria" and i thought i would check in.

went to the doc and got some antibiotics, and had the wife checked out, she is on the edge
of getting pneumonia from this crap... so i got to watch her closely over the next several days.

now the stepson is also showing signs of the same crap!  damn!

all this in august?  wth?

anyway let me answer a couple questions that the OP presented of late

1. i would replace the head gasket at your earliest convenience. if it is a small seep i would not let that stop me from modifying to a water pump and pressurized system.

2. yes i drill a ~1/16" hole in the outer flange of the Tstat,  and have also used an 1/8" hole with a small cotter pin inserted to reduce the leakage and to also keep the hole clear (its wriggling around keeps corrosion from clogging the hole.

with the pump working it allows some water to bypass the Tstat, reduces the pressure on the pump somewhat and aids in circulation around the Tstat bulb.

3. i use the little bosch auxilliary heater pumps typical of VW, mercedes, audi and other german cars and am convinced even though they are quite small they have enough capacity to keep up with at least 20hp.

i connect the pump so that it pushes coolant into the block up through the drain cock port, and i take the hot water off the top of the engine plate via a honda thermostat housing. from there to a small car radiator which has an electric fan and a thermal switch that turns on at about 214F and off at about 205F.

i use a 195F tstat

the theory of operation is as follows

the engine starts and the thermostat cycles until the engine temp exceeds the 195F rating, whereafter it stays fully open and the fan controls the temperature from then on maintaining between 205 and 214F

the cylinder head runs about 240F at these temperatures and at full load, which i set at 8kwe

the antifreeze is 50/50 mix

under full load operation, the fan will cycle on and off at approx 30 seconds on, 90 seconds off
in ~70F ambient temperatures. this tells me there is ample cooling capacity for either more hp or higher ambient temps, both.

as for the st10 and your 2.5 ton ac

i would +1 for Ronmar's comments
there should be no reason this setup shouldn't startup that load
apparently there is a voltage drop or something else going on here.

bob g

[buickanddeere]

Hold it right there dude. running the exhaust into the shack instead of piping the exhaust out? Sorry but I just have to ask why would you do something so incredibly stupid ?

My engine exhaust runs out the bottom of the trailer into an automotive tail pipe/muffler. I was talking about exhausting the air inside the enclosure with an exhaust fan. Sorry for the confusion.

mark

I see a picture of an exhaust stack inside a generator shack ?

[dmarkh]

I see a picture of an exhaust stack inside a generator shack ?

You must be looking at the intake?

[playdiesel]

I see a picture of an exhaust stack inside a generator shack ?

The picture is my set,

If I had stepped back 2" when I took that pic you could see the door jam for one of two 5 foot doors on the front of the shed that are kept wide open when the set is being used. The muffler is about 12" from one of the doors when closed. The eves of the shed are also opened up when it runs. That combined with the breezes created by the ST fan, the flywheel, belts and cooling fan  the engine is little different than being outside. A known problem with the China engines is breaking of the exhaust elbows or the four flimsy bolts that attach it to the head after some home brewed exhaust system is hung on it.   I am not real smart, but far from stupid, kinda in between actually.