1000 liter IBC Tote for thermal storage

[veggie]

Has anyone used an IBC Tote for thermal storage ?
Apparently the HDPE plastic is rated for continuous duty temperatures of 110C (230f).
I think that's a bit of a stretch and I would never intend to operate near those temps.
I am considering the possibility of using one inside a well insulated (outdoor) enclosure as a store for thermal heat.
This way I could push heat from my generator and solar hot water panels into the same low level heat storage tank.
I suspect my target temp would be 140f.

From the tote, I could circulate water through the wall radiators in my cabin.

Anyone have experience with this ?

veggie

[BruceM]

Polypropylene is more common for higher temps.  HDPE structural strength is going to seriously deform well below it's melting point at 260F.   I'll be very interested to know how your setup holds up if you do use the IBE. 

More common is the use of epdm rubber sheet lined wood/plywood tank.  EPDM will take the heat for 20 years.  Typically foam board is used to line the wood box, then EPDM goes inside that.  Another approach is a band of sheet metal to make a round tank, with ripped foam board planks and  EPDM or other liner inside that.  I like the latter for extremely low cost, the thin sheet galvanized is entirely in tension. 

See-

builditsolar.com 

Great website, really nice retired aero engineer owns it and has provided a lot of good data on his designs

[Jens]

Hey Veggie, I hear that things are a tad nippy out your way these days ..... not a vegcickle yet ?

I did at one point look into that but if I recall correctly the temperature rating was more in the 80 degree C range. I think you would be ok at 140F.
I agree with Bruce, much better to build a wooden tank to maximize volume for the available location. It's also inherently more secure and if you plan to build an outdoor enclosure, you are already half way there anyway!

[veggie]

Hey guys,

(Jens,...  -29C here this morning)   

I did a bit more digging around. It seems that 140f-175f is quite safe for totes.
Companies such as this...
http://www.kapton-silicone-flexible-heaters.com/TOTE%20HEATERS-Brochure.pdf
make industrial tote heaters.

The nice thing about the totes is that they are free ! (in my case) and I can fit them into a small skid enclosure that is not much bigger than the tote.
Was thinking that I could insulate the heck out of it (Enclosure and tote) and drag it beside the outside wall of my mechanical room.

Jens, what was the temperature of the low level heat that you used to maintain in your hydronic system ?
I was planning to circulate 150f water through my wall radiators.

veggie

PS:
Found this on an HDPE Tote mfr's website...

Plastic Properties of High Density Polyethylene (HDPE):
A linear polymer, High Density Polyethylene (HDPE) is prepared from ethylene by a catalytic process. The absence of branching results in a more closely packed structure with a higher density and somewhat higher chemical resistance than LDPE. HDPE is also somewhat harder and more opaque and it can withstand rather higher temperatures (120° Celsius for short periods, 110° Celsius continuously).

[DanG]

Is the tote carrier, the wire cage that lets it be hauled by forklift, included?

The limits suggested may be to keep the molded plastic from deforming and bulging beyond the cage mesh.

How about cutting the top(s) off and lining with foam board and the membrane, make a nice double-walled safety container...

[veggie]

My plan is to keep the plastic tank within it's metal frame for strength.
Push heated water in thru the bottom connection and draw water from the top to circulate.

veggie

[Jens]

The nice thing about the totes is that they are free ! (in my case)

Jens, what was the temperature of the low level heat that you used to maintain in your hydronic system ?
I was planning to circulate 150f water through my wall radiators.

veggie

PS:
Found this on an HDPE Tote mfr's website...

Plastic Properties of High Density Polyethylene (HDPE):
A linear polymer, High Density Polyethylene (HDPE) is prepared from ethylene by a catalytic process. The absence of branching results in a more closely packed structure with a higher density and somewhat higher chemical resistance than LDPE. HDPE is also somewhat harder and more opaque and it can withstand rather higher temperatures (120° Celsius for short periods, 110° Celsius continuously).

I feel the sudden urge to come to Calgary (in the spring though!) to pick up a truck load of free totes. I paid around $100 for mine and sold them for $75.
Keep in mind that there is all kinds of different plastic and just because one outfit spec's high temperature it doesn't mean that what you have available will be the same plastic.

I would suggest that 150F is too hot for open wall radiators (from the 'burn your fingers view) unless they are screened. You might also run into issues with erratic heat. I ran my hot water into a water to air heat exchanger that was in the plenum of my central hot air furnace. By the time it came out of the registers it was about the same temperature as if the electric furnace had kicked in. My heat storage system went up to about 180F maximum before the engine would shut down so the actual water going into the water to air exchanger could be up to that temperature but was usually considerably less. Flow though the heat exchanger was turned on by the regular house thermostat and would last longer with colder water.

If burning of body parts is not an issue, I would try 150F especially at the current temperatures out there. You got nothing to loose and setting up a tempering system if 150F is too hot is fairly straight forward.

[Jens]

Is the tote carrier, the wire cage that lets it be hauled by forklift, included?

The limits suggested may be to keep the molded plastic from deforming and bulging beyond the cage mesh.

How about cutting the top(s) off and lining with foam board and the membrane, make a nice double-walled safety container...

The plastic liners are not strong enough without the cage. Cutting off the top only serves to reduce physical strength and encourages quicker cooling by evaporation.

[veggie]

Running the system at 150f is what I had in mind,
I am sure I will have lots more questions as I finalize the design.
My evacuated tube solar panels make 2600 btu/hr each. There are five of them.
I am also incorporating engine coolant heat and electric element head from the generator.
This system has real "dollars in the pocket" value because the current heating for the building is done totally by electric baseboard heat.
In the coldest months the electric bills can be fairly high. If I can cut the demand on the electric elements by 50% it will make a huge difference to heating costs.

veggie

[veggie]

By the way....
is it ok to send 150f water back to the engine for cooling ? or do I need to temper (cool) the engine coolant to a lower value ?

or .. to put it another way...

Assuming a 195 thermostat, what is the max temp for coolant returning to the engine ?


veggie

[mobile_bob]

i don't recall exactly but my 195 trigen from memory had a return temperature of about 180F
and the fan did not kick on till 214F, and cut off at 205F

in my opinion i see no reason why one would need to or would it be beneficial to the engine to have return water any cooler than that.

many large engine's run with ~5-10 degree differential

fwiw

bob g

[Ronmar]

Return temp limit is dependent on flow.  IE: with a higher starting/inlet temp, you will need to move a greater weight of water to transfer a given BTU out of the engine with a fixed outlet temperature.

[glort]

I think Sunlight and UV degradation is more of a problem with IBC's than hot water.

I used one for a test of my oil burner fitted to an old gas heater and had the water in an IBC boiling.  Admitedly, I didn't keep it there constantly for days on end but I don't see a problem with that.
The cages on the IBC's are very supportive and on slone you could even get a thin sheet of ply or something down the sides to support it even more. Not needed I don't think.
It would be easy to insulate the whole thing with roof batt type material or sheet Expanded polystyrene.
You might even be able to get some old cool room panels and use those as a box which you could screw together as the stuff has enough structural  integrity.
That stuff has a really high insulation value.

[Jens]

By the way....
is it ok to send 150f water back to the engine for cooling ? or do I need to temper (cool) the engine coolant to a lower value ?

or .. to put it another way...

Assuming a 195 thermostat, what is the max temp for coolant returning to the engine ?


veggie

No problem at all on the 150F. As mentioned by Ronmar, flow will determine the maximum temperature. Of course engine load also counts.
You will probably be ok up to about 200F on the cold side (more if you have any kind of pressure coolant system going)

[mobile_bob]

you might consider dropping the tote down into a reinforced plywood box, leaving a couple inches all around and then pouring in some of that expandable foam?

it would expand and fill the void, insulate pretty well and give excellent support to the tots plastic side walls.

just a thought anyway.

i think you can buy the expandable foam as a two part sort of thing you mix and dump where you want it, or maybe you just hire an insulation company to come out and fill the thing?

alternatively,

build the box, line it with styro blue board or whatever similar that is available, bed the tank down in some sand, fill it with water and then pour sand all around the sides to fill the void... the sand would support the plastic tank side walls and also add a bit of thermal mass?

it might be possible to also incorporate a cooling loop in the sand around the perimeter, that  way you would have a good degree of separation so that the loop could be used for domestic hot water without the risk of poisoning yourself with antifreeze that might be used in the tank?

just some thoughts

bob g