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A Steam Odyssey (Part 2): Midco Low-NOx Burner

MarkSMarkS Posts: 462Member ✭✭✭
The first Odyssey thread was getting rather long so I've started another specifically for the Midco burner and controls.



I'll let JStar comment on any specifics, but from my perspective the burner installation was pretty straightforward. The burner came in four pieces: the Midco controls cabinet, burner, blower, and valve train. I had to make a few modifications to the cabinet wiring to tie in my own controls cabinet, the flame rollout safety, and the solid state relay that acts as the "call for heat".



The valve train, starting from the blower, consists of a gas orifice, manual ball valve, Dungs FRG6 ratio regulator/zero governor, another gas orifice plate, and a Honeywell redundant combo gas valve. The blower is an ebm-papst RG175 electronically controlled centrifugal fan. Flame safeguard is via a Fenwal DS3565 gas ignition control. The only proprietary part is an RTC electronics board customized for Midco that regulates the blower speed. Except for the RTC board, everything is off-the-shelf parts.



Here are some photos of the burner installed on my Utica Starfire SFE steamer.
Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
· ·
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Comments

  • MarkSMarkS Posts: 462Member ✭✭✭
    More Midco photos

    More photos of the installed Midco burner
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    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Modulating Control Cabinet

    Here are some pics of the modulating control cabinet and hardware.



    The 12 volt supply powers the single-board computer and sensors.



    The 24 volt supply powers the thermostat and vaporstat lockout circuits. The Midco burner has its own 24 volt power on board, but that's only active when the burner is on, so I needed a separate 24 volt supply for the t-stat and v-stat.



    The 24 volt relays on the left side of the cabinet are for:



    1) Vaporstat high-high pressure interval lockout timer relay,

    2) Thermostat on/off (the computer's digital inputs are 5 vdc so need an isolation relay here),

    3) Midco burner firing status,

    4) Midco burner fault status.



    Didn't really need the last two but I had the sockets and relays lying around and room in the cabinet, so I figured why not?
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    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Midco Burner Operation and Control

    Here are some details on the controls for the Midco burner.



    A call for heat activates a solid-state relay that puts 120V power to the Midco burner cabinet. A Fenwal HSI (Hot Surface Ignition) control unit in the Midco cabinet handles the ignition and burner management functions. Once the Midco goes through its ignition sequence and low fire is confirmed, my controls take over, modulating the burner firing rate with a 2 to 10 vdc signal, with a minimum output of 100 MBH and a maximum of 500 MBH on the LNB-500 (the LNB-1000 model goes up to 1000 MBH). There's a software-adjustable high limit in my control system that restricts the modulating voltage it to the boiler's max Btu input rating, in this case 280 MBH or about 3 vdc. The modulating control has several modes of controlling the voltage to the burner:



    Modulating Control with Override



    The initial output voltage to the burner is set to the high limit value and begins modulating on pressure from there. Since the pressure at startup is zero, the output will stay at maximum until pressure builds. This should yield the quickest preheat time, and as pressure increases the control will cut back the voltage to maintain the steam pressure setpoint, in this case 0.4 kPa (about 1 oz/in2 or 0.06 psi) . If the stack temperature drops below its setpoint, it will override the pressure control and modulate based on stack temp. This is intended to keep the stack temperature high enough to prevent condensation. It will automatically switch back to the pressure signal when the stack temperature is above setpoint.



    I set up this control anticipating the burner at low fire might have condensing issues with the stack temperature. So far though, stack temperatures have been high enough at low fire that the override may not even be necessary.



    Modulating Control without Override



    Works the same as Modulating With Override, except that the stack temperature is removed from the control strategy and the system controls exclusively on pressure.



    Fixed Output



    In addition to the modulating output, there is a separate power supply that delivers a fixed voltage to the burner. This is intended to be used when the system is in "Thermostat" mode. In this mode, the system operates as if it were a single-stage non-modulating burner.



    Manual Output



    For testing and experimentation purposes, the modulating control can be put into "manual" and the output set anywhere between the low and high operating limits.



    On/Off



    This is left over from my original single-stage oil burner controls and won't be used with the Midco burner.
    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • SWEISWEI Posts: 4,508Member ✭✭✭
    Fun project

    been watching this one and really look forward to seeing how it performs...
    · ·
  • LarryCLarryC Posts: 331Member
    Electrical question

    MarkS,

    If your thermostat uses a mechanical switch contact for generating the heat call, does the Solid State Relay draw enough current to keep the switch contacts clean?  I have run into issues when driving digital inputs with mechanical switches, I did not draw enough "wetting" current and the switch operation became erratic after several hundred cycles.



    LarryC
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Solid State Relay

    Hi Larry, the solid state relay is driven by a 5 vdc output from the single board computer in my modulating control cabinet that manages the outdoor reset control, DHW (I have a tankless coil), and burner modulation. I also have the wall thermostat as backup; when the system is in "thermostat mode", the thermostat activates a 24 vdc relay that switches 5 vdc to the SSR.
    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Videos of the Midco LNB-500

    I've made three videos of the burner and controls in operation. The first and second videos include a look through the viewport while the burner is operating.



    In the first video, the Midco Low-NOx burner goes through its ignition cycle, then maintains low fire at about 120 MBH.



    In the second video, the burner goes through its ignition cycle, then ramps up to high fire at about 275 MBH.



    The third video is of the modulating control. Here I've already raised a head of steam and am modulating the burner to maintain 0.4 kPa (just under 1 ounce per square inch) steam pressure in the boiler.



    Here are the links to the videos on YouTube:



    Low Fire Test



    High Fire Test



    Modulation Test
    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • SWEISWEI Posts: 4,508Member ✭✭✭
    edited April 2013
    modulation test

    Seems to be hovering around what looks like 225 MBTU/hr (am I reading that right)?



    I'm curious what outdoor and indoor temps that rate is associated with.





    thanks~
    Post edited by SWEI on
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Modulation

    That's right, between 225 and 230 MBH seems to be the sweet spot. I haven't finished tuning the pressure controller yet, but it seems to control pretty well seeing how the accuracy of the pressure transmitter is +/- 0.02 kPa. When the video was taken it was between 45 and 50 degrees outside and 70 degrees indoors. It will be interesting to see how it performs in colder weather.
    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Combustion results

    About the same as when you were here, Joe. Neil from Midco brought his suitcase analyzer yesterday and spent a lot of time trying to dial it in. We get very good NOx numbers out of the burner, but stack temps are still running hot so efficiency suffers. Neil is taking the results back to his engineers to look over; we'll see what they come up with.
    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • JStarJStar Posts: 2,322Member ✭✭✭
    edited April 2013
    Midco

    I have a theory...



    The burner runs so damn hot, that you could probably grossly undersize the firing rate. 100K worth of ol is 200K to this burner.



    You are making a hotter flame with less BTUH's.
    Post edited by JStar on
    · ·
  • ChrisJChrisJ Posts: 2,820Member ✭✭✭
    edited April 2013
    Ugh

    This is really making me wish I installed a Mega-steam instead of going super simple like I did with an atmospheric.





    I love the control cabinet and your software!!!



    How does that burner work? It looks like it has a sausage made out of mesh that acts as a burner?
    Post edited by ChrisJ on
    Weil-McLain EG-40 connected to 392sqft of radiation via two 2" risers into a 3" drop header and 2" equalizer. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment Typical operating pressure 0.5 - 1.0 inch wc.

    Steam system pictures updated 1/25/15.
    https://picasaweb.google.com/thetube0a3/Boiler?authkey=Gv1sRgCImUxIqv9436MQ#

    Don't push the envelope, eliminate it.
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Radial burner

    The radial burner is a tube about 20" long and 3" in diameter. It's covered in some sort of fuzzy metal mesh which I think showed up better in the high fire video. The centrifugal fan is bolted onto the end of the tube. Gas goes into the blower on the right side, and the fuel/air mixture is injected (?) into the radial burner.



    Your post reminded me that I forgot to post a photo of the burner before it was installed. Here it is.
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    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • ChrisJChrisJ Posts: 2,820Member ✭✭✭
    Interesting

    Is there any maintenance needed for that type of burner?





    One thing is for sure. I could not have installed this type of burner my self. I was able to do the atmospheric type fine but this is way beyond that.
    Weil-McLain EG-40 connected to 392sqft of radiation via two 2" risers into a 3" drop header and 2" equalizer. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment Typical operating pressure 0.5 - 1.0 inch wc.

    Steam system pictures updated 1/25/15.
    https://picasaweb.google.com/thetube0a3/Boiler?authkey=Gv1sRgCImUxIqv9436MQ#

    Don't push the envelope, eliminate it.
    · ·
  • JStarJStar Posts: 2,322Member ✭✭✭
    Burner

    The maintenance is rather simple. Clean the flame sensor and electrodes. Clean the burner as needed. Fire and test. I think this burner is was beyond most of the population. You would need MarkS on every maintenance/service just to go through the controls!
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Yeah, but I'm a controls geek

    and my system is designed for flexibility and experimentation. No way you'd put that in the average home.



    But it doesn't have to be that complicated. To set up a basic pressure control scheme, all you'd need is a pressure transmitter and a single loop controller with a 2-10 vdc output, both of which are readily available. The call-for-heat can be a wall thermostat, a Tekmar or other outdoor reset control, or even a Nest thermostat (if their adaptive algorithms for steam actually work). This all assumes that any problems with the steam system itself, main venting and the like, have been corrected. Otherwise a modulating burner probably won't help. As Mr. Scott once said, "I canna change the laws of physics!"
    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Real world conditions

    Overnight temperatures were in the 30's so I got to see the burner perform under real world conditions. Here are the statistics for two runs this morning. The Preheat cycle is the time it takes to heat the mains and see steam at the condensate sensor on the farthest radiator.



    First run

    Preheat: 8:42 / 35.0 MBtu

    Heat On: 31:13 / 122.4 MBtu

    Total Cycle: 39:55 / 157.4 MBtu



    Second run

    Preheat: 7:42 / 31 MBtu

    Heat On: 19:49 / 75.4 MBtu

    Total Cycle: 27:31 / 106.4 MBtu



    Both Runs

    Preheat: 16:24 / 66.6 MBtu

    Heat On: 51:02 / 197.8 MBtu

    Total: 1:07:26 / 264.4 MBtu



    The Beckett oil burner was rated at 245 MBH. For the same total time, that's 273.6 MBtu. There's not enough data yet to tell if the difference is significant.



    I've attached a plot of the two runs. I need to spend some more time tuning the pressure controller to eliminate the oscillation when the pressure first comes up.
    JPG
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    MidcoModulation.JPG
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    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • EastmanEastman Posts: 616Member ✭✭
    edited April 2013
    Question

    What is the difference between this burner and what one would typically find mated to  say a Giannoni style heat exchanger or other water tube style mod/con?
    Post edited by Eastman on
    · ·
  • SWEISWEI Posts: 4,508Member ✭✭✭
    differences

    It's a low volume product, has discrete gas train parts ahead of it, and has a mounting plate like an oil burner.



    Oh, and it costs a bit less than half what a similarly sized mod/con boiler does.
    · ·
  • EastmanEastman Posts: 616Member ✭✭
    So nothing a little duct tape won't resolve?

    Does the burner length need to be pretty close to the depth of the boiler?
    · ·
  • EastmanEastman Posts: 616Member ✭✭
    What were...

    the stack temperatures before the conversion?



    Does gas produce a higher volume of combustion products versus oil at similar temperatures?
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    This burner

    is right up against the Kaowool liner in the firebox.
    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Stack temps

    with the oil burner were between 465 and 500 degF. Note that my thermocouple is in the flue pipe about 30" from the boiler. Combustion analyzers probes are inserted much closer to the boiler and read higher temps..
    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • EastmanEastman Posts: 616Member ✭✭
    Sounds like it's

    working pretty good.  What is the heat loss for your home?
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Heat Loss

    I used the Slant-Fin Heat Loss Express software to calculate the heat loss for the outdoor reset model. It's 133 MBH if you count the 3rd floor (used for storage; there are two radiators up there, one's turned off), and 106 MBH for just the 1st & 2nd floors. The model has been more accurate at predicting the heat-on time using the lower number.
    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • BioBio Posts: 174Member ✭✭
    Wondering

    Wondering if your radiators are fully hot or top half hot in order to satisfy the thermostat, any difference with the change of burners
    · ·
  • ChrisJChrisJ Posts: 2,820Member ✭✭✭
    Adapt

    Will the software learn and adapt to changes?



    Such as if ts really windy one day and calm the next?
    Weil-McLain EG-40 connected to 392sqft of radiation via two 2" risers into a 3" drop header and 2" equalizer. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment Typical operating pressure 0.5 - 1.0 inch wc.

    Steam system pictures updated 1/25/15.
    https://picasaweb.google.com/thetube0a3/Boiler?authkey=Gv1sRgCImUxIqv9436MQ#

    Don't push the envelope, eliminate it.
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Depends

    on how long the system runs. During recovery from setback (4 degF) most of the rads will be hot all the way across. On a normal heat cycle maybe half to 2/3 of the way across. In mild weather it's even less than that.



    It'll be a while before I have enough data to tell what difference the burner makes. What I know right now is that I'm controlling the burner at just under an ounce of pressure and am getting steam to the rads, where with the oil burner it was at 1.75 ounces. That's got to be saving fuel and $$$. But I think that's more a function of the corrected near-boiler piping than the burner.
    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • EastmanEastman Posts: 616Member ✭✭
    What's preventing...

    the burner from dropping to an even lower btu output?  What's the road block in the train of components there?
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Sort of

    The outdoor reset model I've developed knows the heat loss of the building and the heating capacity of the boiler. During a cycle, when the system transitions from Preheat (heating the mains) to Heat On, the software fetches the current wind chill temperature from a local WeatherBug station over the internet. The model uses the lower of the wind chill and outdoor sensor values in the equations that calculate the btu input and run time required to achieve setpoint. Lower temperature = greater heat loss = longer heat-on cycle time.



    So while the software adapts to current conditions, it doesn't really learn from one cycle to the next.
    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • BioBio Posts: 174Member ✭✭
    Another thought

    It will be interesting If you could follow Boilerpro's theory, you could under fire and vent very small on the rads, longer fires at lower btu's, confortable heat, no overshooting and efficient just a thought....
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Limits

    The low fire output of the burner is 120 MBH (the specs say 100, but we clocked 120 on the gas meter). That's controlled by the RTC electronics in the Midco cabinet. It's probably limited by the ability to maintain a good fuel/air mix at lower blower speeds. I'd guess the limiting factor is the gas regulator; those electronically controlled motors can be driven accurately over virtually their entire range.



    On Thursday we ran at low fire for 45 minutes while we did some initial testing. In that time we raised a head of steam, heated the mains, and started heating a few of the rads. One of the experiments for this fall when the weather is colder is to see just how low I can run the steam pressure while still getting adequate performance from the radiators.
    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    That's a plan

    That's in my plans for the fall, I've been fascinated by Boilerpro's theory and would love to try it for myself.



    JStar had an idea about running the system like a coal boiler; run the burner on "simmer" to keep the mains warm and then ramp up when there's a call for heat.



    I built the controls to be flexible and configurable just so I could do experiments of this sort.
    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • EastmanEastman Posts: 616Member ✭✭
    edited April 2013
    What did Boilerpro say?

    He was talking about orifices?



    **********************************

    Are there any electrically activated valves that are compatible with one pipe steam?  I was thinking perhaps one could stage the delivery of steam into the rads over the cycle in such a manner as to maintain system balance throughout the range of modulation.
    Post edited by Eastman on
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Boilerpro's article

    Boilerpro wrote an article in 2009 with an interesting perspective on sizing steam boilers and venting. Here's the link:



    http://www.heatinghelp.com/article/323/Boilers/1551/Taking-Another-Look-at-Steam-Boiler-Sizing-Methods-by-Dave-Boilerpro-Bunnell
    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • MarkSMarkS Posts: 462Member ✭✭✭
    Payback's a

    wonderful thing. I know we don't talk price here, but did want to provide some idea of the expected payback period since the initial outlay is pretty hefty.



    I prepay for 1100 gallons of fuel oil each year. Around these parts, natural gas (including supply, distribution, and other surcharges) is less than 40% of last year's prepaid cost of oil. That'll save me an estimated $2500 a year at current prices. Counting the cost of the burner, installation (excluding the piping rework), and the electronic & hardware components for the modulating control, the payback is less than three years. Maybe even sooner if you figure a modulating burner ought to use less fuel than a single-stage burner under similar conditions.



    Incidentally, this made it a relatively easy sell to She Who Must Be Obeyed, although what really got her attention was the "greener" aspect of lower emissions from the Midco Low-NOx burner.
    Links: EcoSteam | A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz | 4 mains, 135 ft | All Gorton vents
    · ·
  • SWEISWEI Posts: 4,508Member ✭✭✭
    How's the sound level when the LNB is firing?

    I'm hoping that ECM proves less annoying than a typical induction fan.
    · ·
  • vaporvacvaporvac Posts: 826Member ✭✭✭
    71dcbls

    Mark addressed this issue in Part 1 of his steam odyssey near the end of the thread under  "We have ignition". He also then responded to my query  "quieter...but quiet?"

    http://www.heatinghelp.com/forum-thread/145950/A-Steam-Odyssey-Midco-Low-NOx-Burner-Oil-to-Gas-Conversion-Project



    It's near the end of the thread.



    "As for the Midco burner - absolutely smooth install and startup. And

    quiet - at my boiler's rated input I measured 71 dB 18" behind the

    blower, compared to 86 dB for the Beckett oil burner."





    Quieter...but quiet?

    Thank you for posting the decibels. I've been worried about the loudness

    of the power burners, but the  two (2) x Riello  #G400 series #C8554115

    gas power burners I've ordered for the SF TR50s are rated by Riello at

    66dcbls. I didn't have anything to compare that to so it looks like it

    shouldn't be too bad. I know the Becket oil burner was louder, but would

    you consider the 71dcbls to be quiet?



    Fantastic job, Jstar.



    Looking forward to studying the burner install.

















    Reply

    Edit











    MarkS

    MarkS

    April 20, 2013

    @ 4:47 PM









    Contact this user











    Quiet

    Of course it's all relative but yes, I'd consider 71 db to be pretty

    quiet for a running motor. You could hear the Beckett running on the

    first floor, and feel it too. Can't hear the Midco on the first floor at

    all, except for the 15 second purge cycle when the blower runs at high

    speed. In fact, when the Midco is at low fire it's hard to tell it's

    running even when you're standing right next to it.
    Two-pipe Trane vaporvacuum system; 1466 edr
    Twinned, staged Slantfin TR50s piped into 4" header with Riello G400 burners; 240K lead, 200K lag Btus. Controlled by Taco Relay and Honeywell RTH6580WF
    · ·
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