Is storage a "must" with a gasifier?

[McKraut]

A couple things I think are important if you do have storage;

You should have enough storage capacity to carry your heatload for a long enough time to make it worthwhile.Like charging storage once a day or every other day.

You should have a big enough boiler to charge the storage in a reasonable amount of time to fit a persons schedule.

I have only 500gallons,so it won't carry my load to long,but it works nice in the spring and fall.This time of year not so much. The boiler runs pretty much steady,because it's not oversized.

As far as wood consumption goes,not so sure more storage(or any at all)would help me with current sized boiler.
The past few days I have had the storage valves turned off just to see how things go.It does go into idle once and a while,but it doesn't really smoke a lot. I think I use slightly less wood doing it this way.
With the storage turned on,seems like the boiler runs and runs and unless the firebox is kept full,the output is lower and storage temps don't rise with zones steadily calling for heat. With storage off,seems like a load of wood goes a long way. I don't know,maybe it's just me.

I suppose the thing to do would be to weigh the wood loads a week or so each way and compare to heating degree days.

In any event,not sure storage helps too much if the boiler is closely matched to the heatload.

I think the ideal would be modulating output like the pellet boilers,but but you can only turn the air down so far.
Maybe the thing to try would be throttling the output(nozzle size and air)to match demand more so it can run steady with good gasification at different outputs. Probably not as simple as it seems.

When you have your storage valves turned off, how often do you have to fill your boiler? How big an area are you heating?

Your signature looks like you're heating with an Eko and you have 45,000 gallons of storage. I had to look at that twice.....

 

[McKraut]

A couple things I think are important if you do have storage;

You should have enough storage capacity to carry your heatload for a long enough time to make it worthwhile.Like charging storage once a day or every other day.

You should have a big enough boiler to charge the storage in a reasonable amount of time to fit a persons schedule.

I have only 500gallons,so it won't carry my load to long,but it works nice in the spring and fall.This time of year not so much. The boiler runs pretty much steady,because it's not oversized.

As far as wood consumption goes,not so sure more storage(or any at all)would help me with current sized boiler.
The past few days I have had the storage valves turned off just to see how things go.It does go into idle once and a while,but it doesn't really smoke a lot. I think I use slightly less wood doing it this way.
With the storage turned on,seems like the boiler runs and runs and unless the firebox is kept full,the output is lower and storage temps don't rise with zones steadily calling for heat. With storage off,seems like a load of wood goes a long way. I don't know,maybe it's just me.

I suppose the thing to do would be to weigh the wood loads a week or so each way and compare to heating degree days.

In any event,not sure storage helps too much if the boiler is closely matched to the heatload.

I think the ideal would be modulating output like the pellet boilers,but but you can only turn the air down so far.
Maybe the thing to try would be throttling the output(nozzle size and air)to match demand more so it can run steady with good gasification at different outputs. Probably not as simple as it seems.

I just read the last line of your signature. You're not kidding. I just got 190 gallons of heating oil delivered and paid almost $800. It's the first time in 3 years that I've had to order oil. If it wasn't for my woodburning boiler, I would have a lot less money in the bank. With this old house I figure I save at least $4000 a year.

 

[mr.fixit]

From what I know the lambda units alter the primary and secondary air on the fly.
I think a pellet boiler alters the feed rate of the fuel going in.

With a wood boiler,I envisioned some way of throttling the fuel via adjusting the size of the nozzle opening and the air settings on the fly.
It would take some redneck engineering I guess.

 

[velvetfoot]

It's too bad pellets can be so expensive compared to wood-the boiler can be as controlable as oil.

 

[mr.fixit]

When you have your storage valves turned off, how often do you have to fill your boiler? How big an area are you heating?

Your signature looks like you're heating with an Eko and you have 45,000 gallons of storage. I had to look at that twice.....

I probably fill it 3 times a day,but there is usually some left in there. With the storage turned on the the boiler is always completely empty(when reloading) because it keeps running to heat storage and loads till it fuels out.

I heat around 4000 sq ft in 3 separate buildings(4 if you count the garage that the boiler is in) so a pretty good load for a 40.

 

[Duetech]

If you can go to an outside gasifier you might want to look at Portage and Main. The Optimizer 250 is a gasifier that has its own storage built in like a regular OWB but burns like like a gasifier (very little smoke), shuts down when heat demand is met and is very efficient compared to an OWB. They have larger models if you need one but the 250 is rated for up to 5000 sq ft. Outdoors the mess is kept out of the house but the wood has to have special protection from the elements to be prime for use in a gasifier.

 

[chuck172]

lately I've turned down my boiler aquastat to aprox. 180/160. I've been using my 500 gallon storage as sort of a buffer tank.
The boiler cycles on and off often. I used to always keep the boiler aquastat on the highest setting. The storage would be 195*.
I know the boiler will require more frequent cleaning, but the wood usage has dropped. The system seems to run very even and efficient.

 

[KenLockett]

lately I've turned down my boiler aquastat to aprox. 180/160. I've been using my 500 gallon storage as sort of a buffer tank.
The boiler cycles on and off often. I used to always keep the boiler aquastat on the highest setting. The storage would be 195*.
I know the boiler will require more frequent cleaning, but the wood usage has dropped. The system seems to run very even and efficient.

Chuck, here is a trend of my TarmSolo Plus 40 over a six hour window. My boiler temperature setpoint is set at approximately 186 DegF. The yellow and red pins trend the idle and firing periods respectively while the green pen is trending the actual boiler temp. Even with the swing between the firing and idle cycles I am able to maintain the home temperature at almost 70 DegF dead-on with temps down to around 0 DegF. More idle/firing cycles over a 24 hours period when the outside temps are colder obviously.

Ken

 

[Clarkbug]

Ken,

I think its awesome that you are using a seat of WonderWare to trend your boiler.

 

[KenLockett]

Ken,

I think its awesome that you are using a seat of WonderWare to trend your boiler.

Thanks. Got a pretty cool setup at this point. As I mentioned to you before I have an Automation Direct Click Micro-PLC with RS-232/485 capability (two ports) interfacing to the Wonderware HMI using a generic Modbus RTU driver. Was able to finally interface to my boiler supply TC using a Tx Controller also from Automation Direct with RS-485 communications. Anyhow, the first Tx Controller I bought I returned for the relay version (remember you sent me the data sheet on the solid state output variety that I could never get to work) and I use strictly for the alarm contacts. With the Click PLC and floating point capability I am actually able to detect when a reload is required based upon temperature versus firing profiles that I generated based upon the firing cycles. I generate audible alarms when I begin each idle cycle and a different audible when a reload is required. Still tweaking the prediction curves but is working very well. Being able to trend the supply Tx provides amazing insight with regard to combustion patterns. I can now tell from the trends when I have extended idle cycles and thus how best to load. I can even gauge reduced heat output due to bridging. Have not had to restart a fire since we had that warm weather over a week ago. I will post some pics when I get a chance.

 

[EffectaBoilerUser (USA)]

I would never be without storage for all of the reasons listed prior to my post. Having used my gasifier with storage for 5 years now I just wanted to summarize the benefits of using storage:

1.) Allows the boiler to burn WOT (wide open throttle) for a more efficient/cleaner burn. When a boiler idles it is less efficient and produces more emissions.
2.) Allows the user to go much longer between burns and to make fires when they want to vs. when they have to. I am able to heat my 1000 gallon water battery up to 190-195 Friday night and return home Sunday night to find the house only a few degrees lower than the set temp. of 73F. However, the storage allows me to heat my 4,000 sq. ft and hot tub for the entire weekend without using a drop of propane!
3.) Reduction in the amount of wood used per season.
4.) Allows me to provide for all my DHW in the summer time for 5-6 days on only ONE 5 hour fire!
5.) Shortens the ROI of the entire system.
6.) Allows the integration of solar thermal in the future thus reducing wood usage even more!

Many of the wood boilers mentioned on hearth.com are made in Europe and Europe has been using this technology much longer than most of us in North America. The fact that most of the systems in Europe use storage (and many use solar thermal) tells me that storage is very important.

 

[peakbagger]

I am currently going through "withdrawal" due to a temporary lack of storage due to a problem with one of my components. I still can heat the house in the evening with the boiler unless I want to run the boiler with its damper closed and turn it into a smoke dragon I have to put up with overheating the house. I don't have the time in the AM to get it fired back up again, so the oil boiler is running during the day. I have used more oil in the last two weeks than I have in a year.

I heated with a wood stove and oil for 15 plus years prior to the wood boiler and storage and boy is it easy to get spoiled to have working thermostats and the need to only run the boiler once a day instead of frequent trips to the wood stove. I use more wood than before but up until the recent problem I really didnt use any oil.

 

[stee6043]

I would never be without storage for all of the reasons listed prior to my post. Having used my gasifier with storage for 5 years now I just wanted to summarize the benefits of using storage:

3.) Reduction in the amount of wood used per season.

5.) Shortens the ROI of the entire system.

Point three might be true but it would depend entirely on the application. Adding storage to a properly sized, properly operated existing gasser system may not reduce wood consumption in a measurable way. Adding storage to a grossly oversized boiler with a massive firbox may indeed provide a measurable reduction in wood consumption.

Point five is flat out wrong. There is no way that adding significant cost to a new system for the PRIMARY purpose of added burning convenience is going to accelerate ROI. It's going to extend it, considerably.

 

[Coal Reaper]

Point three might be true but it would depend entirely on the application. Adding storage to a properly sized, properly operated existing gasser system may not reduce wood consumption in a measurable way. Adding storage to a grossly oversized boiler with a massive firbox may indeed provide a measurable reduction in wood consumption.

Point five is flat out wrong. There is no way that adding significant cost to a new system for the PRIMARY purpose of added burning convenience is going to accelerate ROI. It's going to extend it, considerably.

five COULD MAYBE be true if using storage for DHW in summer instead of fossils or electric. gotta figure out if summer saving warrants extra cost.

 

[EffectaBoilerUser (USA)]

Sorry about that on point 5.

Points 4, 5 and 6 all go together.

I use my system with storage 12 months out of a year and thus by using it all summer I am able to reduce my hot water bill by approx. $250 (6 months at $40-$50 per month for a family of 4). The (2) 500 gallon tanks cost me $250 each and thus in 3 years (this covers the cost of the additional piping also) I have saved enough in propane costs for summer hot water to pay for the 2 tanks. In addition, I have been able to use this storage for the 6 months of winter heating season which lets me reap the benefits of items 1, 2 and 3.

This summer I will be adding a solar thermal system to my Effecta boiler with water batteries and will be able to make FREE hot water when the sun is shining. See attached drawing.

Hope this helps in clarifying the benefits of water batteries (thermal storage).

Brian

 

[kopeck]

I guess it's all about your setup (heat load) and what works for your schedule.

My boiler is the smallest Tarm makes, I use it with 820 gallons of storage. I have an old farm house that's been renovated so it's insulated, not super insulated but we're talking R-20ish walls, plus new windows and doors.

With this setup, during the prime heating season (Dec-March) I load up twice a day. On really cold days I usually have to throw and extra armful in before I go to bed, on warm days I can get away with on fire a day but those are the extremes in that season.

I could have gone bigger on every thing and probably avoided starting fires as much but I don't think it's that big of a deal and I save my self some cost up front. Either way I would be burning the same amount of wood.

I think I would have liked to try a 1000 gallon tank if I was going to do it again, just to have a little more head room but the 820 takes care of my work day and then some so I can't complain.

Needless to say I like storage. It also gives you opportunities to try other things, like I'm debating installing a Geyser to keep my water temp up for DHW during the summer. Solar would be another option.

K

 

[Clarkbug]

Thanks. Got a pretty cool setup at this point. As I mentioned to you before I have an Automation Direct Click Micro-PLC with RS-232/485 capability (two ports) interfacing to the Wonderware HMI using a generic Modbus RTU driver. Was able to finally interface to my boiler supply TC using a Tx Controller also from Automation Direct with RS-485 communications. Anyhow, the first Tx Controller I bought I returned for the relay version (remember you sent me the data sheet on the solid state output variety that I could never get to work) and I use strictly for the alarm contacts. With the Click PLC and floating point capability I am actually able to detect when a reload is required based upon temperature versus firing profiles that I generated based upon the firing cycles. I generate audible alarms when I begin each idle cycle and a different audible when a reload is required. Still tweaking the prediction curves but is working very well. Being able to trend the supply Tx provides amazing insight with regard to combustion patterns. I can now tell from the trends when I have extended idle cycles and thus how best to load. I can even gauge reduced heat output due to bridging. Have not had to restart a fire since we had that warm weather over a week ago. I will post some pics when I get a chance.

It sounds like you and NoFossil could collaborate on a few things. He may have some helpful insight on the prediction curves if you wanted to pick his brain. Glad to hear that so far its working out for you!

 

[Floydian]

Another benefit of storage: No fire overnight and no fire when no one is home. Peace of mind and high approval rating with the wife.

Noah

 

[Fred61]

Another benefit of storage: No fire overnight and no fire when no one is home. Peace of mind and high approval rating with the wife.

Noah

That benefit rates very high in this houshold too. There has been no overnight fire here for 4 years and only two or three during the day before 4:00 PM. One of those was when I used hot water for about an hour to de-ice a flight of concrete steps with a water hose.