Oil Burner Question

Constantin

Hi Everyone,

I had a silly set of questions regarding oil boiler designs that I hope the rest of you can put a light on. As I am a homeowner with very little oil combustion appliance experience, please allow me to display my grandiose ignorance in this particular field.

The marketplace on the oil side seems divided between those with proprietary oil burning appliances (Viessmann, et. al) and those who make a boiler that a burner gets bolted onto (Buderus, Smith, etc.). My focus is on the latter, i.e. the seperates.

It appears that the burner and boiler manufacturers have a hard time ensuring that the settings they recommend as starting points will actually work in all conditions. That is, not produce too much smoke, a negative draft, etc. Yet, none of the burners seem to adapt their behavior on their own, which puzzles me.

For example, would it not be possible to employ feedback control on a combustion system much like an engine management computer does via the O₂ sensor?

Perhaps this is impossible considering the gamut of boilers that burners are attached to? Or is even this minute amount of modulation outside the reach of most burner manufacturers? ...I was thinking of just modulating the fan blower to meet the required smoke/CO₂/etc. specs over a wide range of environmental conditions so that the burner is efficient under all conditions.

It just seems crazy that setting up a oil burner should be that difficult (Note the recent thread re: alleged Buderus woes). From what I read in Carrying the Torch, the process is somewhat involved and does not necessarily ensure best efficiency over a wide set of conditions. Now if there is a $5 solution to this problem (rather than the $30 one I guess I am proposing above), please let me know. I'm simply curious....

Ken_8

$$$

Connie,

The technology is old. The prices too high.

When a $250 Beckett goes to $1,200 with a simple feedback controller - you can hear the death knell all the way from Elyria, OH.

Strikingly, the Euros won't pay for it either - and God knows, the Euros can afford anything!

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Robert O'Connor_6

oil success

Lots of oem oil applications are set up with success. That thread just highlighted one potential problem area. What you should really look at is what the reps had to say and how manufacturers conduct themselves when they have trouble.

Regards,

Robert

ME

DaveC

If you modulate the fan motor...

then you would also be modulating the pump speed, and consequently the pump pressure and oil flow. I don't know if the resulting air/fuel ratio would stay in proportion by doing this (over a wide range of blower speed) - but a significant reduction in pump pressure could occur as the unit tries to respond to the sensor(s).

Just offering this thought based on theory, not experience, though.

J.C.A._3

I saw an example,

Of which you speak, last summer at the Brookhaven National Labs. It was a Japanese modulating oil burner. It was controled by the same parameters as a Munchkin, feed temp., and return temp.. The DC variable speed motor increased and decreased with the temp curve, and what looked like (to me)a fairly primitive form of fuel injection was adjusted accordingly.As a side note.... Dr.Tom told us that the original version was shipped with a voice activated control, but no-one in the lab spoke Japanese very well, so they sent for the digital control package.

The things you speak of are not far off. From seeing them, and talking with field personal, the biggest PERCEIVED problem is the field techs themselves. The feedback ran the gamut from awe, to....you won't get these guys to understand anything like that, anytime soon.(which I TOTTALLY disagree with!!!!) Oil techs ARE NOT a bunch of dirty handed knuckle draggers, there are some of us who can suck this stuff up with a bit of training. The ones that refuse to learn it....Godspeed. Your gonna be left in the dust buckeroos! The future is bright, the people who repair and install oil equipment have to be the same. Chris

Constantin

I'm surprised this is the case...

... remember, I'm not talking about modulating the oil flow, merely ensuring good combustion via controlling the flow of air with a O₂ or CO₂ sensor. A negative feedback loop then adjusts the air flow to ensure proper combustion, which should lead to no smoke, etc. In other words, I'm only talking about modulating the easy part, i.e. the combustion air flow, not the oil. Am I missing something?

Such technology does not have to be expensive. I doubt it would cost more than $30 to add it, considering that a DC blower-motor is probably a wash vis-a-vis a comparable AC model, a VR-regulated pwer supply is peanuts, and the only additional wiring/logic would be the comparator and the O₂ or CO₂ sensor.

Granted, it would cost extra. But it might save the consumer and the installer sufficient amounts of time to make it all worthwhile. After all, I bet your billing rates aren't going down like the costs of these components. Cheers!

Constantin

Hear Hear!

After all, setting up a boiler should not take hours. The proper starting settings should be indicated (at the very least) on a web-site that is easily accessible.

In fact, a really good manufacturer would put together a Java-program or something for a pocket computer where you can input the various factors and thus find the right nozzle faster. I don't think this would be that hard to do. The equations are out there, the environmental conditions can be noted, etc.

I mean, if the heating manufacturers give away heat-loss programs for free, why cannot they give away an installation program as well? I'm sure that a program that hits the right nozzle on the head 95% of the time would be popular indeed!

Constantin

Are they coupled?

I thought the fan and the pump motors were independent entities...

Constantin

Long-term,

I see no reason why modulation will not come to the oil side. The benefits to low-mass systems are simply too great. However, cost, reliability, and survivability will be large factors in determining when this technology will come to fruition.

After all, other attempts at full modulation have died infant deaths before (see the Carrier Infinity scroll as an example, I am told). Cheers!

ed wallace

modulating oil systems

yes the manufactures can provide programs but how is a tech supposed to axcess them in a basement most techs i know cannot grasp the idea of using the internet

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Ken_8

They are coupled!

To have it any other way would be very expensive. Gas power burners are much easier to do this with and it is done. We have done it many times. The problems are that it is not cost effective on small boilers. The one's we did were $5,000 a pop full mod Power Flame 'C' burners.

Two separate servos driving completely independent air and gas inputs and controlled by an e-prom we had to manually program. Took 8 hrs. each to dial in!

As you already suggested, this is outside your area of expertise, but you're smarter than most and tou need to know the end cone, combustion chamber, oil viscosity, fan speed, static pressure and clean burn are extremely inter-dependent.

Having gone to Brookhaven National Labs last month to see the latest technology, I can assure you, oil burners with the features you mention on a residential burner are as likely as winning the lottery. It is possible. But don't hold your breath.

The costs exceed the ability to conserve/save oil. Hell, we're already at near condensing efficiencies now, how much better can they make them without re-inventing the boilers?

We have a few 100+ HP C/B's that get near 90% efficiency with modulating oil and air that arec NOT coupled. But that's only because of the three pass scotch marine design of the boiler - not the bruner's separation of fuel and air supplies.



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Unknown

We offer this for free

Look at page 11

http://www.slantfin.com/boilerpdf/XL40.pdf

Noel

Slant/Fin Corporation

oil-2-4-6-gas

.

the new commercial burners are starting to come out with this technology-- individual servo motors-work independent combustion air oil metering and gas metering --controlled by a stack mounted 02 trim system ---in these applications the combustion air is seperate w/a constant oil pressure ,the oil to the burner is a metering pin and a valve that controls gas --you would need a different type of oil suppy system then what is currently available for residential burners

Unknown

Lo/hi fire burners already exist

Cost effectively, too, I might add.

What would full modulation gain over a dual rate burner, in a small, say, 0.50/1.50 GPH application?

What more would it cost?

Since there would be no gain in combustion efficiency, how long would it take to pay back the more complicated design?

Noel

Slant/Fin Corporation

DaveGateway

I'm suprised we don't see

more use of HeatWise's Hi/Lo firing burner. Here again the issue must be getting optimized adjustments for both fire ratings. Other problem is the Pioneer is a 1GPH plus burner so 140K BTU boilers and under couldn't use it anyway.

Robert O'Connor_6

Beckett and Carlin

have theirs on the webb and available at supply houses in a book. Riello hasn't had one in a few years and have taken it off the web, Not sure why.

Robert O'Connor_6

Slant fin L30

Has a chart rght on the boiler showing different nozzle specs etc.

Robert

ME

Robert O'Connor_6

Yeah Chris and Noel that Hermann

burner we saw last month was modulating too.

I think that rig that was in the french aluminum hx was modulating too.

I heard that was the same hx as the Munchkin but I've not seen the munchkin so I'm not sure.

Anyway I'm very sure it's in the future but how far out I have to wonder.

Look at the new truck engines that run on eight cylinders when accelerating and then four when cruising. Wow


All the best

Robert

Constantin

Point well taken

The benefits of full modulation are unlikely to be significantly better than a 2-3 step program. However, even a simple hi/lo burner could be very beneficial at allowing the system not to short cycle.

Another possibility is the changing of the AFUE testing regimen. If testing was along the lines of typical homes across seasons, you may see the same divergences in efficiency design philosophy as we can observe in the AC industry today. SEER and EER are no longer necessarily related...

Under "more realisitic" circumstances, a low mass boiler may show better results than a comparable large mass boiler due to less warmup and standby losses (much like an on-demand vs. storage water heater). Granted, adequate insulation will negate the advantage to a large extent and greater thermal mass makes control a lot easier when the burner only allows a on/off firing sequence.

Note how I used the term "more realistic" with quotation marks. After all, I have never seen a statistic regarding the ON/OFF cycling of boilers across the season. For all I know, they simply don't short cycle much even in balmy weather unless they have been grossly oversized.

Bill Nye

It does

take a great deal of time to set up a burner. When you need to do nozzle comparison you have to run the burner take your test and then replace the nozzle, run another test etc. etc.

The problem here is, unless it is the dead of winter your boiler or water heater or furnace is going to reach high limit very quickly and you will be lucky to complete your test before the burner shuts off.

You may need to try 4 or 5 nozzles . Different brands , patterns, spray angles, flow rates, pump pressures, etc. Once the heat exchanger or refractory is warmed up it may mask some problems with your later tests. A hot combustion chamber is going to burn better than a cold one. A warm chimney is going to pull more draft than a cold one etc.

Oil is a very small portion of what the boiler people produce. Mostly gas. Warm air is almost always gas. New England and the mid atlantic coast is where the oil is for the most part the rest of the US is gas or electric or [shudder] heat pumps.

The money to re-tool and r&d this type of burner would not be recouped by the manufacturer. Most people would not want to pay for it. Unless uncle sam mandates it and taxpayers pay for it............. I doubt you will see it.

Maybe in a few years you will have your own reactor and every few years we will come around in white suit and change your pellet.

Weezbo

I like your thought..... *~/:)

theres my thinking cap /snow hat:) it helps my brain keep from freezing up in cold weather ..sortta like WWSD cepts different:) Long time ago i considered my self fairly savey with the boiler burner instead of modulation control i considered using lag relays they are cheap:) eh hemmm.. inexpensive:) i tried bumping up fuel pressures lowering fuel pressures considered maybe building my own motor with like a rheostat that let some thing of a modulation in a fairly narrow range,considered using a sheet metal zone valve in the flue,.. noticed many things.....with the burners we have with a motor driving the pump and fan,lagging the burn causes smoke issues. sorta you would think that once you had the temperature comming up that to back off the burn you would get better atomization because of the heat increase in the chamber. however,a certain amount of fuel is not going to burn off quite like youd hope for so you think well maybe if i increase the pressure a bit more ....hee hee ) ok there goes another pump:)) so ...what if i drop back the pressure well that too brings up smoke ok so what if i change the draw crank up the combustion air? I had lots of fun and often looked like rory racoon:)))oil solenoilds were fun too :)))) I am not altogether satisfied that the burners we have are doing the best of jobs how ever...they are fairly reliable an a bit better than the previous Blast Furnaces we called The New Retention head Burners:))) i am interested in the Herman modulation boiler and have kept my ear to the rail and the oil tech talk guy is open and honest about things and has consideration for many of the details and minor technicalities...He has certain reservations and is concerned that he says right and doesnt send anyone off in the wrong direction....it takes experience and lots of unbiased objectivity when doing experimentation..the min you want certain results you gotta step back and listen to the questions others have .some times from a kid comes an obviously sane objection 'The King! He aint wearing any Clothes!' so ,...while the idea you have sounds intriguing mmm cha nope,there are physical restrictions built directly into our trade burners. if" fixed" settings to get a tech into the ball park can be rough to deal with ,consider(a).seperate motor for the oil pump,(b) a seperate air blower with its own motor,(c) a motor to move the gun back and forth in the draw,(d)stack Sensors to communicate with these parts water sensors to communicate with the entire assembly .the minor technicalities could be monitored with a diagnostic Brain however just these few changes arent going to be inexpensive and the gain well could go kina pricey. now say you added a speed controller to the oil pump motor,an air shutter that opens wider or closes tighter see? my engineer buddy could build me one of whatever i think up however i have to say it could be Really Pricey he d go with some fancy robotic control to mix and move all kinds of parts about due to various in puts and make some sorta chip to manage this masterpiece )) umm i think for reasonable rates and all however then if we were going to have to jump the hoops on all kinds of government agentcies to determine if this is this and that is that i can see this particular burner going into the numbers a guy such as myself would find slightly off the charts! here is the basic nut to make as the old timers would say once you got the nut to your axel back then you gotta market the thing .....if its too spendy who wants to buy one? sure it is year 2000 and can sing and dance and carry a happy tune however who is gonna want one of these gizmoes ? and who is gonna fix it when something goes awry? i am already stressed an i am only Thinking about it.*~/:)

Firedragon_4

Noel, did you get the package???

Firedragon_4

True except for the fuel pump cut-off problem.

Firedragon_4

I've had a two-stage in my home

for 19 years, 15% overall savings over same single-stage burner. Burner is stepped lo-hi-lo for heat (below 22 F) and DHW. Burner is not listed, but is MA approved with special exemption, not available in US, YET!

Unknown

yes, thanks

Would you like yellow pages that aren't the most current, but close, for your project?

Noel

Firedragon_4

Absolutely and thank you!!!

Ken D.

Combustion set up.

The present system is not perfect, but a heck of a lot better than it used to be. Boiler and furnaces were not sold as packages at all. You bought a boiler and then you bought a burner. The dizzying array of combinations were never tested and it was pot luck on weather your combination would burn cleanly or efficiently. (I never did get a good fire out of a SilentFlame burner.)It has been so much better in these days of packaged units. I will not install anything else. Once in a while a combination will not burn properly and it usually is with a new package. If it is too much of a problem, I will not use them anymore. But, progress is not remaining static.

Ken_8

Connie,

What you suggest is already achieved. Not by modulation, but by existing fixed firing rate design!

The existing "plain jane" burners, Beckett & Carlin, attain 85+% easily in most boilers. The reason they are not more efficient is not because of their design - but because the boilers cannot handle the condensate!

The only way to make an on/off, johnny homeowner burner attain more efficiency is to have condensation take place.

The properties of small firing rate (under 50 MBTU's) has yet to be resolved. Air atomization has some promise but nobody makes air atomized small firing rate burners.

I know Bola, the CEO of Heat-Wise and he DOES make the only truly small oil burner I am aware of. It comes in the Monitor FCX and gets an AFUE rating of 92+.

Step-mod burners and full mod units abound. However, they are attached to 1MMBTU boilers and cost is relatively higher.

I guess the rhetorical question is, "Why make the burner modulate when it is already getting 84% AFUE (which actually means the entire efficiency - including short cycling or when 'on' AND 'OFF'? While no one makes a boiler that it could condense in?

IMHO, oil will have to go to one-hundred bucks a gallon to justify even thinking about a three or five percentage point savings.

It ain't happenin' because it can't be done, it ain't happenin' - because it is a costly solution to a problem that doesn't exist.

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