Wood fired boiler to power air conditioner/chiller

[Buzz-sawyer]

Nothing new or novel about this idea.......just need some help in the practical side of scaling it down and making it work ....here are the basics.

Using existing wood fired boiler to run a loop of regulated 160-180 degree water to a chiller.

The chiller is water/ammonia type used in industry, often powered by waste heat.

I AM NOT a HVAC guy by trade but am pretty familiar with plumbing, thermo-dynamics, vac.ETAL.

Any wild suggestions from your own MAD schemes .......or something in this order you have seen somewhere....???

[ronwood]

Buzz,

I just made a post asking for an explaination of what yopu just described. I bought a Central Boiler a couple of months ago and am in the process of installing it. The model that I have you can control the temperature. Quit interested in the subject.

Thanks
Ron

[Buzz-sawyer]

OK
The idea is to use CONTINUOUS-CYCLE ABSORPTION SYSTEM , the continuous-cycle absorption cooling unit is operated by the application of a limited amount of heat.

This heat is furnished in this case by wood waste. No moving parts are employed.
The operation of the refrigerating mechanism is based on Dalton's Law.

Absorption chillers come in two commercially available designs: single-effect and double-effect the solar powered chillers are venturing into triple effect efficiencies.

absorption chillers can substantially reduce operating costs because they are powered by low-grade waste heat. Vapor compression chillers, by contrast, must be motor- or engine-driven........But there are NO moving parts in an absorbtion system.......the BEAUTY OF SIMPLICITY!

[SwampDonkey]

What are you up to now Buzz???  ;D  8)  :P

[maple flats]

Good luck on this one, I used to sell outdoor wood fired units and the mfgr had a cooler they were working on to do just that. Their engineer got it to cool but they had to keep the water temp up to 208 degrees and it cooled. They kept having the problem of the unit frosting up when the humidity got high and they were never able to find a solution. They eventually gave up after spending over 5 years on building test models and trying different ideas and I'm sure spending literally hundreds of thousands of dollars to no avail. BUT, many great inventions have followed a long list of failures. Good Luck.

[wiam]

Buzz, I know nothing about this but I am quite interested.

Will

[Buzz-sawyer]

I dont consider the workability or viability of doing this an issue..........

First of all I am NOT an engineer.....so I dont know what I CANT do... :D :D :D

Second.....Thousands of these units are in operation all over the world........mostly LARGER.........but in for a penny in for a pound.......

Third.........I wont be spending hundreds of thousands of dollars.......so that wont be a problem


Fourth.... Literally milions of absorbtion units are functioning on RV"S and remote cabins all over the world....powered by propane karosene etc.......They burn at a consistent temp.....
Solar refrigeration units of the type I described are in use ALL OVER the world........If I can mimic then Just might work

Fifth......Im to ignorant to know better :D :D :D

[wiam]

Buzz I have done things and found out after that they were not possible : :

Will

[Buzz-sawyer]

Out of 2500 members of this forum there has to be at least one HVAC type that produces wood waste that has had the same idea?!?! :D :D :D

[trim4u2nv]

My freinds dad had some natural gas powered refrigeration when we were kids.   He worked for the gas company.  I think these were ammonia, not cfc based systems.  Got me wondering if I took apart my old butchers freezer (NH3) and my  proposed  truck wood gasifier and combined the two.  So many ideas so little time!

[ronwood]

Buzz,

What if you could use a refrigeration unit from a tractor trailer that carrys frozen food. I not sure how they work but I think they are power with diseal fuel. 

Ron
 

[Buzz-sawyer]

Well Ron
I like the idea but that is kinda different type project

.they have a diesel engine, compressor, cfc refrigerant..........basically a standard unit with a zillion moving parts........the one I am talking about has NO moving parts.......which is part of the fun ;) :D :D

[JimBuis]

In a former life, I was a heating mechanic, i.e. did everything on the heating side of things.  What equipment do you have versus what you need to acquire?  What are you going to heat and/or cool?  House, garage, something else, all of the above? ???

Jim

[Buzz-sawyer]

My goal , in more practical terms, is to be able to cool one households freezer needs and refrigerator as well as a 2500 foot home .....recon about 5 tons?

Can common black pipe be used with hydrous ammonia ?

I am a competant welder, (was a certified welder)........

refrigerant temperatures of 45° to 50° F (7.2° to 10° C) are suitable. In this temperature range, water can be used as a refrigerant with an aqueous salt solution, usually lithium bromide, as the absorbent material...........this seems like a good possibility!?!?

[Corley5]

I'm interested   I have no idea how this works but I'd sure like to be able to use my wood boiler for air conditioning ;D

[Corley5]

Is this the same principle that gas refrigerators work on ??? 

[Buzz-sawyer]

Yep

[J_T]

Buzz course I have  8) The old ice house used amonia not sure the type . I scraped one once they had a pipe inside a pipe been a long time. They had huge compressors also I mean big 8). With the wood fire idia I just got off on sompthing else and never came back .. In case of over heat I think you would need to dump in an accumalator as a bypass and at the same time pressure regulated at around 70lbs low side and not exceed 500 high side . The gas units at least the older ons were trouble . Mane thing I think you would need is a bunch of time  copper tube if using R 22 which you could blow real cold off of and a bunch of sealfoss and t stats . Hope I didn't over bore everyone   Pm me some time Buzz or call

[Buzz-sawyer]

JT
Thanks.....but you aint boring no one.....thats what this thread is about 8) 8) 8) 8)
What I am needing is some plain ideas about what kind of material, amount of coolant etc...
I want to go with a absorber...no moving parts type unit...........

[Don_Papenburg]

Black pipe would work ,but nitrogen  is corrosive to steel and aluminum  . However the tanks are made of thick steel. The corrosion comes in when oxygen gets involved.If you plan to keep it for a long time try to find a deal on stainless.

[Buzz-sawyer]

Thanks Don
About the nitrogen in the NH3....how does the oxygen get in a closed system?
Have you built anything likr this?
Buzz

[Kirk_Allen]

Buzz we need to spend a day over at Dads. I have some stuff stored over there that would blow your mind. 

On thing that comes to mind to make the WATER BETTER is long chain polymers.  We patented a process for rapidly disolving water based polymers, thus making the water thicker or more viscous.  Lots of advantages to that.  The problem has always been getting the polymers to go into solution.  We fixed that. 

Its on the shelf right now waiting on $$$$ to take it to market.  We do the same thing with both petrochemical based products and acids. 

Like I said, we should go play for a day.  I think you would have a ball! 

[Fla._Deadheader]

  CAN I COME ???  CAN I COME ??????

[SwampDonkey]

We live in exciting times. ;D :D

[J_T]

Buzz using R22 all you would be doing is making a sustem like an rv refrigretor uses .Things to control would be exess heat or low heat of the R22 .Got to keep pressures right .Don't rember how the gas fired rv unit worked gitting old . You wouldn't need to get as cold as they do. I beleve a back yard engeenner could build one and keep it going but would be hard to make for everyone as some can't keep a pet rock alive : And it could drive a repair Co up a wall and the cost would kill them. I get lots my sensors and contactors and transformers from old central units .Might consider putting a compressor in line to conpensatet for ballance of odd temp. As in holding low side pressure at 65lbs. On that old ice house they used amoinia like someone said in a closed loop and chilled brine and set large bucketts in a vat and made huge ice blocks.Buddy of mine helped install unit in Plano Tx on JC penny building if I rember right it is a large icemaker  makes ice in off peak hours and dumps it in a ben and blows air across it to cool the whole place . So I am sure you can make sompthing that will work using your boller . I got some high and low side coils and a large compressor that will pump most types freons been thinking about building a kiln one thees days . But my round tuit is square at present  :D :D Can't have air in any theese systems. Kirk may be on to sompthing too. If you can put a bunch of idia's together no telling what you can come up with  8) Rember Coloumbus took a chance and look at us now :D :D Using freon you just need good filters and pull a good vachum any time you break into the lines on a high mosture day or if open long. You can build a vacum pump in a few mimetts if you don;t have one and it will work as a compressor too. Or I can loan you my store bought one  ??? On the heat side of a boller we used a high side coil from an old ac unit to heat a house trayler and it wooks good and was free has been working two years so far.Much cheeper than the ones they want to sell you.

[Buzz-sawyer]

Any body recognize this???
It was sold in the 1930's as a simply kitchen appliance .....THE ICE BALL ...just set one side in hot water an wa'la'........ice


Kirk sounds interesting :P :P........actually I have been experimenting with a similair process with vegitable oil in the process of making bio diesel more simply.

Deadhead YES 8) 8)

JT
It sounds like ya are in the same book on this thing...........I primarily need some "Brass tacks"....simplified practical pointers ta set this up.........book learning is one thing actual experience, such as yours is GOLD ;)

[Fla._Deadheader]

  DAT looks like a good Solar project.  8)

[Buzz-sawyer]

Intermittent Solar Ammonia Absorption Cycle Refrigerator

[SwampDonkey]

Buzz, good thing it's the weekend cause ya wouldn't have any time to run the saw with all this brain storm'in. ;D :D

[Fla._Deadheader]

  Donk, Ya gotta admit, he's GOOD at it though.   ;) ;D

[Buzz-sawyer]

Swampy .......A valid point.........If I am indoors....I am reading and studying this forum and one or two topics of intererst Simultaneously.............PROBABLY altogether too much!!!!
However, being that this is my principale excess.I often excuss myself :D :D :D
When it is rather hot (100) here..........you will see my posts OFTEN! 8) 8) ;)
EDIT
Hey nobody is on here more than YOU swampter :D

[SwampDonkey]

Me? !  ;D :D :D ;D

Big brother must be watching me again. Or there's a hidden time clock I forgot to punch out at.  Err, hmmm : Don't let them posting numbers fool ya, they can be edited. ;D :D

[Don_Papenburg]

The O2 gets in if a valve is left open ,say in an empty tank. or the valves on the tank where the hose connects tends to rust if the dust caps are left off.
I never did any thing that compicated  . I have just graduated to Ice House . Hope it will work . I have been interested in heat activated cooling since I was a Kid and my grandfather had a natural gas fridge. Boggled my mind that a fire under the fridge could make it cool. That just wasn't logical to a young fella.

[wiam]

The guy I bought my Central Boiler from claimed to have the technology, but not the time to hook it up to his walk-in cooler.  I might have to call him.

Will

[Buzz-sawyer]

JT
I want to build a 5 ton unit, capable cooling the house and food.
Tell me some more about your a/c projects

[dail_h]

   I been keeping up with this the whole time,still don't understand the fire to ice thingy. Anyway when I got home from church today,my buddy Ben was here messin with his tractor.He lives at the beach,his JD 50 lives with me ;D ;D ;DHe is an industrial refridgeration contractor or some such thing. I asked him about this thread,his reply was oh h%^%$ thats simple as droppin dead,and proceded to 'splain in great detail the theory and howto,'course it was lost on me. I know he knowes what he's talking about though, 'cause he built his own ice plant several years ago,and made a living with it for several years. He'e just now finishing up a portable ice plant for cooling sweetcorn,and brocili.
   I tried to get him to come on here and help out,but he's currently offline,has some foreign(Russian)students living in his apartment. If you guys are really interested in talkin wif him ,im me,and I'll get your # to him. Told him I was thinking of puttin in a boiler for heat,he said he could do the ac easy. Would have to use ammonia,and black iron pipe,copper,and brass can't stand ammonia. Hope this helps

[Buzz-sawyer]

Well, it could help If ........................I could pick his brain about the particular practical things I need to build my 5 ton system. like Him jawing with me saying,"This is how I would do it Buzz!"............ ;) :D ;D

[DouginUtah]

Back in the early 70s I lived in an apartment building with natural gas air conditioners. All summer long, at least twice a week I would see the Gas Company guys up on the roof trying to get them working.  :(  Maybe they are better now, but I doubt it.

-Doug

[Buzz-sawyer]

Well Doug, Every high rise in the entire world uses chillers powered by gas..................???
Maybe a few heat the ammonia with eklectric...but thts VERY expensive.

[Buzz-sawyer]

We have lots of newer members and chiller specialists out there???

[Don_Papenburg]

They better show up it's getting to that time of the year when we need to cool our beer.

[Buzz-sawyer]

Plus, Don, I like to cool off the ole Buzz whenits hot too 8) 8) 8)

[SwampDonkey]

Go jump in the river. :D :D :D

[Don_Papenburg]

Then you have to go take a bath  , the river is poluted.

[electromech]

   I drew up a sketch. Even with lower pressure at the evaporation point I'm not sure aqueous ethylene glycol at any percentage would create a cool enough solution to refrigerate. Even with a really hard vacuum the solution boils at lowest around 150F. No CFCs, non-corrosive, not explosive, not much pressure, built in antifreeze etc. Only down side I can tell (If it would cool) is that it's toxic if you drink it.

Any speculation on ammonia or methanol for this system.  Ammonia being corrosive to most metals and methanol explosive when mixed with oxygen.

Address to aqueous ethylene glycol data sheet http://www.meglobal.biz/media/produc...Global_MEG.pdf
Feel free to shoot holes in my sketch. Tips welcome

[Al_Smith]

Absortion types of chillers have been around for decades .Nothing new about them .It's the way a gas refridgerater works .Fact the main chillers on the U-boats were large lithium bromide units .

How to regulate such a system I have no idea but I do know they work .

[bandmiller2]

Buzz,seems to me you just have to substitute wood for gas in the old servell system. Frank C.

[SwampDonkey]

Buzz hasn't been around since the year that post was made I believe.

[submarinesailor]

Here is a little info on absortion chillers:  http://en.wikipedia.org/wiki/Absorption_refrigerator.

Bruce

[barbender]

I miss Buzz and many others that have moved on.

[sawdust]

Electromech, question for you. Pressure being equal on all sides of a vessel, what is to allow the cold return line to flow? The pressure on both sides of the evaporation restriction would be the same, no?

When I get home I have some good links. I really like this discussion thank you. I would like to see a pumped system with a wind turbine and use propane as the refrigerant.

Somewhere on the forum there was a discussion along these line and a reference to the movie Mosquito Coast.

[pyrocasto]

Electromech, welcome to the forum and what an interesting topic you decided to revive. I've wanted to build an absorption cooler running off solar or wood for many years, just never found the DIY examples to do it.

I will do it one day. :D One day.

[electromech]

     Sorry about the late reply.
     After I had posted I noticed the original post dates were 2005.  Sorry to hear that Buzz isn't around anymore.  A real loss when the experienced are gone.
   
      Sawdust: Response to pressure -  That pipe coming out of the top of the cold chamber probably shouldn't be there. I'd been looking at an ammonia setup before making that figure.  This thing would have to be more of a forced pressure setup. 
      The whole idea is to convert heat from a boiler to cold using heat(cold) of evaporation in a closed system without having to use CFCs so anyone can make one.  Wishing I had tools,time and finances to do some real experimentation.  Propane as you suggest (though explosive when mixed with oxygen) may be the best bet. (the stuff is even manufactured with odor thrown in for leak detection)

[electromech]

     I found a commercial site that has some kind of lithium bromide cooler that runs off of waste heat.
     No clue what the cost is or if they would even sell it to just anyone.  Has a nice illustration of how the thing works.

http://www.yazakienergy.com/waterfired.htm

    Maybe the best thing to do would be to just use the heat from a good wood gassifier to either generate steam or cook wood to make charcoal and woodgas (mostly CO) to power an engine hooked up to an alternator/inverter.  Then use the electric from that to power a regular air conditioner or refrigerator.
   Tough call. Any way you go it gets challenging.

[pitotshock]

Interesting old thread that was dug up here. I have toyed with the idea of a wood fired absorbtion cycle, but I think the problem with the standard outdoor wood furnace is that it doesn't maintain a water temperature high enough to sufficiently drive the ammonia out of solution from the water. Those RV fridges use propane/NG flame or electrical heating element to heat the boiler directly and drive the cycle.

Theoretically, whether you use propane or wood to heat the cycle it wouldn't matter, but directly firing the boiler with a wood fire would be a dirty business compared to the clean propane flame. Cycling off the wood flame when the fridge is cold enough is a bit trickier though.

I see DIY construction of an absorption cycle would involve using stainless steel tubing, vessels and pressure gauges as well as ammonia, hydrogen gas and distilled water: tinkering around with chemical quantities and pressures until something gets going in the right direction, probably outside so you don't gas yourself with the ammonia.
As for basing this on a commercial design, they seem to be open with the generic cycle info, but pretty tight on real information on chemical volumes, operating pressures, temperatures and flow rates. Typical way to define a thermodynamic cycle is to determine your operating temperatures required at the absorber, chiller and boiler. Then from your required rate of cooling (i.e. how many "tons" your unit needs) size the flow rates to achieve that cooling. Absorption cooling is a bit more complicated than a standard refridgeration cycle as there are chemical reactions occuring rather than just liquid/gas phase changes.

Payoff would be good for a backwoods cabin - having a woodstove going means the fridge is cooling with no moving parts. Kinda neat.

Have to dig deep into my brain for those university thermodynamics courses, ouch!