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    A Steam Odyssey: Midco Low-NOx Burner Oil to Gas Conversion Project (50 Posts)

  • MarkS MarkS @ 11:34 AM
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    A Steam Odyssey: Midco Low-NOx Burner Oil to Gas Conversion Project

    Following a series of technical email exchanges with Charlie Aiello at Midco International, I took the plunge and ordered their LNB-500 low-NOx modulating gas burner to replace the oil burner on my Utica Starfire steamer.

    Joe Starosielec (JStar) from ecuacool was out to the house in March to scope out the job. In addition to the conversion, Joe will also be de-knuckleheading the near-boiler piping that the oil company installers put in when the boiler was replaced back in 2009, putting in a nice new 3" drop header, and fixing a few other off-boiler piping issues.

    The burner will modulate based on steam pressure in the boiler, with an override control on low stack temperature. I've spent the last several months re-writing the boiler control software that I described here back in November to run in firmware on a single-board computer, and to add new modulating control algorithms for the steam pressure and stack temperature. In March I finished the wiring and continuity checks for the new controls box, and the unit is now in bench testing with simulated sensors.

    The burner is scheduled to arrive on Monday; the conversion will be done over two days on April 17th & 18th. I'll post pictures and updates as the project progresses.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
  • ChrisJ ChrisJ @ 12:03 PM
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    Nice

    Look forward to seeing the pictures and hearing about the system in the future!

    Have you considered using temperature sensors in the boiler water to control pressure rather then pressure sensors?  I always thought it would be easier to measure temperature accurately then to measure steam pressure at just a few ounces.

    Will you have some sort of safety to take over in case of computer failure?
    Weil-McLain EG-45 connected to 392sqft of radiation via two 2" risers into a 3" drop header and 2" equalizer. Using Rectorseal Steamaster water treatment to greatly reduce corrosion in the boiler.

    Steam system pictures updated 6/5/14.
    https://picasaweb.google.com/thetube0a3/Boiler?authkey=Gv1sRgCImUxIqv9436MQ#
  • MarkS MarkS @ 12:57 PM
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    Pressure

    responds much more rapidly to changes in input than temperature, I've found. Also, the fact that the water in the boiler is boiling doesn't tell you what's happening out in the rest of the system. Could be pre-heating the mains, could be halfway through a heat cycle. On this system the boiling point versus pressure is negligible as I'm running at less than 2 ounces of pressure. Might be different if you were running at 1 PSI, there you're looking at a 3 degree difference, but I still think it would be hard to control to that.

    For ideal pressure control you'd probably want a pressure transmitter at the end of the mains, but I have four of those and even cheap pressure transmitters aren't cheap. The single one on the boiler seems to work OK; I can look at a pressure trend from my system and tell you within +/- one minute of when steam gets to the farthest radiator.

    Safety: I'm working on a series of posts describing the control system in detail, but for now I'll say that the system is set up to fail over to wall thermostat control in the event of a power failure, program crash, or computer failure.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
  • Rod Rod @ 1:17 PM
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    Wow!

    Hi Mark-
       Thanks for sharing your very exciting project with us.  When Chris mentioned temperature sensors, this triggered a memory of a discussion a while back that had me wondering why boiler manufacturers haven’t included a simple safety device of  thermocouple attached to the boiler well below the water line which would detect extraordinary high temperature and would shut off the burner in the case of a dry firing/water loss.  I just mention this in case the idea might be of use to you though I’m sure there is a pretty good chance you have already considered something like  it! :)
    Good luck with the project . We’ll all be anxiously waiting for an update once you have the new system running.
    - Rod
                    
                                       







                         
  • MarkS MarkS @ 1:42 PM
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    Interesting idea

    Would you place such a sensor in the water/air space in the boiler or on the casting? If the boiler was firing and there was a low water condition but there was still water in the boiler, I wonder what the air temperature would be. I'd think you'd see a measurable change in the casting temp if it was dry firing. Either case, I'm not real keen on dry firing the boiler to test it out :-)

    My boiler has a Hydrolevel Safegard-450 LWCO. It came with a CycleGard but I hated the intermittent level test "feature" so I replaced it (anybody want a gently used CycleGard?). Both of those use a conductivity probe, I believe. At any rate, it works well.

    It's probably worth noting that nothing I've done will replace or impede the safety limit controls already on the boiler - the pressuretrol and LWCO.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    This post was edited by an admin on April 7, 2013 2:27 PM.
  • Hap_Hazzard Hap_Hazzard @ 11:05 PM
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    CycleGard

    Mark, is that a 24v or 110v unit? I already have one for my boiler, but I'll. keep it in mind if anybody needs one.

    I'm also going to be watching this project. I've been dreaming about that burner since the first time I heard about it but never put much thought into how to control the modulation other than, uh... maybe a couple of Vaporstats or sumthin'. :-)
    1983(?) Peerless G-561-W-S

    3" drop header, CG400-1090, VXT-24
  • MarkS MarkS @ 5:56 AM
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    CycleGard

    It's the 120 vac unit. The probe has never been used; the CycleGard & Safgard use the same probe so I left the CycleGard probe in the boiler when I put the Safgard in.

    I'm really excited about this project (and I think JStar is too!). Looking forward to seeing how the Midco performs.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
  • Some expanded applications....

    It's great to see the Midco finally going into a real life application.  I've been hoping to install one here in Chicago, but oil fired boilers are not stocked here in Chicago, so winter replacements with that burner are out...for now. 
    I looked over your website with great interest and was wondering if you considered using pressure reset as a control strategy.  For one pipe steam this would be difficult to maintain balance in the system.  For two pipe systems, it has been done in the  past, but not with a direct control of a mod burner (that I am aware of).  This is something I have great interest in and am currenly working to set up several large systems to be able to operate in this way in the future.    The pressure reset could be based on outdoor temp or indoor temp feedback.  It would probably be much simplier to program than your current one pipe programming.
    The Steam Whisperer (Formerly Boilerpro)
    Chicago's Steam Heating Expert


    Noisy Radiators are a Cry for Help
  • MarkS MarkS @ 8:37 PM
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    Pressure reset control

    Hadn't considered a pressure reset control scheme, Dave, but I would be very interested in learning more about it. I have a variety of sensors on and off the boiler, and built a lot of flexibility into the controls in order to be able to try out new ideas like this. Not quite "plug-and-play", but if a control strategy uses the sensors I've got, it's a fairly simple matter to add it to the system. PM me if you'd like to discuss further.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
  • Jamie Hall Jamie Hall @ 8:25 PM
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    sigh... now if only

    someone would develop a modulating oil burner -- even say a 3 to 1 turndown... might almost be worth the money.  Mine is almost perfectly matched to the system (only very long runs cycle on pressure) but it would be nice to sort of kick-start the thing to get it boiling, then turn it down in accordance with pressure...

    Oh well.
    Jamie

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-McClain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • Charlie from wmass Charlie from wmass @ 12:28 PM
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    Jamie Riello has one

    the R series http://www.riello-burners.com/2_products/2_oil-burners/1a_2a_r-series-oil-fired.asp
    It goes down to 2.6 gph on low fire for two stage and down to 2.4 gph for modulating.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Eastman Eastman @ 5:24 PM
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    What are the specs on this burner?

    It's hard to tell from Midco's website.  What is the modulation range on this burner?
  • MarkS MarkS @ 6:36 PM
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    Midco specs

    The LNB-500 is rated 100 to 500 MBH. The LNB-1000 is 150 to 1000 MBH. In both cases, the burner is modulated with a 2 to 10 volt dc signal.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
  • Eastman Eastman @ 8:00 PM
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    What part of this range...

    can you utilize?  
  • MarkS MarkS @ 8:48 PM
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    My boiler

    is rated at 285 MBH input, so I'll be limiting the control voltage to run around that number. Won't know how much turndown we'll be able to achieve until we get the burner in and run combustion tests. The limiting factor will probably be stack temperature (got to keep it high enough to prevent condensation), which is why I've built in a low temperature override to the pressure control, but there's simply no data on this yet. If the stack temps are high enough at low fire, then I'll have full span of control between 100 and 285 MBH.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
  • Rod Rod @ 7:56 PM
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    TRV Cycle

    Hi Mark- I was helping a friend today with 1 pipe TRVs and it occurred to me that with a modulated 1 pipe system (with a burner that modulates rather than occasionally shuts completely OFF) maybe some sort of periodic "shut off cycle" function might be nice to have to allow air a chance to get back into the radiators so that the 1 pipe TRV(s)  would work properly. Just a thought
    - Rod
  • MarkS MarkS @ 8:39 PM
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    Don't see why not

    Hi Rod, that would be easy enough to do, it's a SMOP (Simple Matter Of Programming). If you wanted to get fancy and you knew the performance characteristics of the system, like how the pressure changes as the TRV's shut off, you could possibly calculate when, say 75% of the TRVs were shut and take that as your "breather" down time. Now, if all of the TRVs are shut you should shutdown the burner anyway since you can't put any more steam into a closed system, so continuing to run is just a waste of fuel.

    At what pressure does your friend's system run, and does it have a pressuretrol or a vaporstat? Does it short-cycle near the end of a heating cycle?
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
  • Eastman Eastman @ 8:59 PM
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    I'm not a steam guy, but...

    I've always wondered, hypothetically, is it possible to modulate the EDR of the rads with TRVs for one pipe?  I mean, say you went back to coal.  Would it be possible to use TRV's to achieve even heating at thermodynamic equilibrium?  (assuming you were down in the basement spoon feeding the boiler)
  • ChrisJ ChrisJ @ 9:26 PM
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    Don't think so

    A TRV can only stop the radiator from progressively getting hotter further across, but it cannot stop it from heating whatever amount it allowed during the cycle. The only way to stop it from heating or decrease its output is to stop the cycle and allow the radiator to completely fill with air.

    This is why Rod mentioned allowing the boiler to shut down completely at times. TRVs on single pipe steam do amazing things, but they are by no means perfect and do have some quirks.
    Weil-McLain EG-45 connected to 392sqft of radiation via two 2" risers into a 3" drop header and 2" equalizer. Using Rectorseal Steamaster water treatment to greatly reduce corrosion in the boiler.

    Steam system pictures updated 6/5/14.
    https://picasaweb.google.com/thetube0a3/Boiler?authkey=Gv1sRgCImUxIqv9436MQ#
  • Eastman Eastman @ 9:38 PM
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    Wouldn't it...

    eventually find the happy medium though?  When people talk about TRV's on one pipe, what does that look like?  Does the pipe connect at the bottom and the top, with the TRV at the top and something like a p-trap on the bottom?  And then there's a vent to allow air in and out?
    This post was edited by an admin on April 8, 2013 9:38 PM.
  • Dave in QCA Dave in QCA @ 11:28 AM
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    one-pipe TRV

    Here is a picture of a TRV for a one-pipe radiator.  
    [url=http://www.google.com/url?sa=i&source=images&cd=&cad=rja&docid=0oVYtmV-6DkGdM&tbnid=Hnke6TazXhRpNM:&ved=0CAgQjRwwAA&url=http%3A%2F%2Fwww.heatinghelp.com%2Fforum-thread%2F143953%2FOne-Pipe-Steam-System-Flooding&ei=-9VmUcyGLof09gT_rYCQAw&psig=AFQjCNErxCZxDaUjhUWQ_K9HMw8KWDTwJQ&ust=1365780347808387]
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
    This post was edited by an admin on April 11, 2013 11:49 AM.
  • Eastman Eastman @ 3:55 PM
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    Hold on here...

    That just restricts the air vent, right?  Doesn't this inherently require a cycle based system?
  • Rod Rod @ 5:15 PM
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    1 pipe TRV

    Yes, the one pipe TRV needs a what I called a "shut off" cycle to function properly. The system pressure needs to be zero or actually in a slight vacuum so that air can re enter the radiators through the vacuum breaker.  Since the OFF periods of a modulated burner could be much farther apart, it may then be necessary to introduce the occasional planned shut off period so that air can reenter the radiators.
    - Rod
  • Eastman Eastman @ 5:59 PM
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    Would this work?

    Would this work without requiring a cycle?
  • Dave in QCA Dave in QCA @ 6:12 PM
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    depends....

    It depends on the steam pressure in the main and the depth of the little trap that you've drawn.  1psi= approx 30" water column, so if you have your limite set at 2 psi, the trap would have to be 60" deep to prevent steam from blowing the water out.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • ChrisJ ChrisJ @ 7:04 PM
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    So

    Why not put a steam trap in place of the P trap, or whatever it is.
    Weil-McLain EG-45 connected to 392sqft of radiation via two 2" risers into a 3" drop header and 2" equalizer. Using Rectorseal Steamaster water treatment to greatly reduce corrosion in the boiler.

    Steam system pictures updated 6/5/14.
    https://picasaweb.google.com/thetube0a3/Boiler?authkey=Gv1sRgCImUxIqv9436MQ#
  • Eastman Eastman @ 7:17 PM
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    hmmm...

    Yeah, i can see that.  The steam would push through and chug back and forth right?
    This post was edited by an admin on April 11, 2013 7:17 PM.
  • Dave in QCA Dave in QCA @ 9:56 AM
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    Steam Trap not a solution

    If you installed a steam trap in the location you have shown a water seal trap, the flow would be backward through the trap.  That is, first air in the steam piping would flow into the radiator from the steam riser.  The, when steam arrived, the trap would close, although not real effectively because the pressure would be trying to push the trap open and the element that makes it close would be above where the steam is.  At any rate, any time the trap opened, the differential pressure would cause the flow to be moving from the steam main into the radiator, at least until there was enough condensate pooled in the bottom of the radiator to cool the trap, then it would open. steam would bubble and bang through the trap while condensate was also trying to flow out. 

    In short, to work properly a steam trap must be connected to a pipe which is connected to atmosphere. 
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • Dave in QCA Dave in QCA @ 10:03 AM
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    TRV on the inlet

    If you want to install a TRV on the supply to a radiator, it must be altered so that it operates as a two pipe system.  There are two options for the piping.
    One, connect a new outlet on the radiator with a steam trap connected to a vented return line and remove the vent from the radiator.   This would be the modern trapped 2-pipe system.
    Second option is to leave the vent in place and run a new return on the radiator and run it down to a wet return line with the connection below the NWL of the boiler.  This would be the very old vented 2-pipe system.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
    This post was edited by an admin on April 12, 2013 10:04 AM.
  • Eastman Eastman @ 6:44 PM
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    What about for vapor systems?

    A six inch water trap could handle about 3.4 ounces of pressure.  Can a vapor system operate below that value?
  • Eastman Eastman @ 1:25 PM
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    Variable EDR

    I'm interested in a true solution to the fixed EDR problem.  It seems that the advantages of full burner modulation of the boiler can not be fully utilized unless a variable EDR scheme is also incorporated.
  • Dave in QCA Dave in QCA @ 1:57 PM
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    Inlet Orifices and varying pressure

    It is possible to vary the effective EDR or a radiator by throttling the amount of steam that it receives.  In a 2-pipe system, this can be done by using TRV valves of course.  The total EDR of a system may also be affected if some of the radiators are turned off.  Thus, the firing rate of the boiler would have to vary if you were trying to maintain a constant pressure in the mains and boiler.

    Another way in which you can effectively modulate the entire system is through the use of inlet orifices on a 2-pipe system.  For example, if you have an orifice that is approximately 0.25", it will pass enough steam at 2 psi to nearly heat a radiator of approximately 92 EDR.  At a pressure of 1 psi, the same orifice will pass enough steam sufficient to heat about 65 EDR, or about a 1/3 reduction.  At 8 oz of pressure it will pass enough steam to heat 45 EDR, or 50% of the steam flow that existed when running at 2 psi. 

    Thus, if you are desiring to run a boiler in a continuous firing condition, but want to vary the capacity or effective EDR of the system, you could accomplish that with an orificed system and modulate the pressure in the mains.

    In all practicality, I would have to say from the observations of my orificed system, set up for 8 oz. and controlled by a Tekmar 279, that in mild weather some of the radiators only get mildly warm on the first radiator section.  From the time steam reaches the end of the main and pressure in the main begins to build, the cycle may end before the main even reaches 8 oz.  I think it would be very difficult to establish a continuous low pressure that would not overheat the building at moderate outdoor temperatures.  I also have to report that when set up for 1 cycle per hour, with cast iron radiators, inlet orifices, and Tekmar control, the space maintains a very even temperature.  Most of the time, the sensors do not indicate that there is any fluctuation in the room temperature at all, reading a constant 70F.   That causes me to wonder how much tighter the control could get.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • Eastman Eastman @ 2:26 PM
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    Very interesting...

    I had not thought about variable pressure in the context of an orifice based system.  It sounds like system balance is a moving target throughout the season.  Wouldn't a proportional control system at the rads solve this issue?

    I'm not directly interested in maintaining more precise occupant temps, but that would be an additional result.  If you look at boiler efficiency charts, it appears that much of the efficiency gains are direct result of operation at partial modulation, and not necessarily the result of low supply and return temps.  A system that can maintain thermal equilibrium between supply and load would remain at modulation minimums.
  • Dave in QCA Dave in QCA @ 2:55 PM
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    Varying Pressure

    I offered the possibility of modulating the effective total EDR by using orifices and then varying the main pressure in answer to your inquiry on how that might be done.  But, I do  not operate my system in that manner.  On mine, the orifices are sized for 8 oz main pressure and the boiler controls are setup to maintain that.  Actually, the firing rate has also been fine tuned to maintain 8 oz in the mains.

    My reason for installing orifices was because of a distribution and balance issue.  During partial steaming cycles, which are the norm about 80% of the time in our building, some radiators fully heated and others stayed cold.  Yes, this could have been resolved by installing TRVs on all of the radiators.  But, orifice plates were another way to skin that cat, and at a fraction of the cost.  It has taken a bit of time and the readjustments would have become quite costly if I was hiring a contractor to do all of the work.  But as a retired fellow who in my early working days used to get his hands dirty working as a maintenance mechanic in a hospital, it was well within my abilities to tackle.  The building is now fine tuned and has an incredibly even temperature throughout.

    Yes, in regard to efficiency, operating at a modulating output to match the load does yeild improvements in overall efficiency.  Studies of the savings of high turndown burners tend to account for those savings mostly because the pre and post fire purge cycles are reduced or eliminated and those are inherently wasteful.

    Overall system efficiency is also greatly affected by the systems performance in putting the heat where it is needed and not putting where it is not needed.  So, things like pipe insulation in basement areas and in-wall risers become very important.  Also, minimizing overheating of spaces greatly improves efficiency.  Reducing the occurance of overheating is affected by providing a comfortable space at the lowest possible temperature.  Local code requires 70F in apartments and I find that I get no complaints from tenants at that temperature.  However, if the space fluctuates from 68-71, I will get complaints that is is cold some of the time.  If my system was operating with a 3 degree swing, I would have to turn up the heat to the point that the swing would be 70-73 F.   And, for every degree above 70F that the space is heated to, it represents a loss in efficiency and an increase in cost.  Thus, in this case, added comfort as a result of maintaining constant even temperatures translates to added efficiency and reduced cost.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • Eastman Eastman @ 6:55 PM
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    Another thought...

    ...In the context of one pipe vacuum; there appears to be an unresolved issue with air accumulation in the rads.  At some point the system will certainly need to go positive, but between each purge cycle, perhaps a TRV based system could maintain balance.
  • MarkS MarkS @ 5:49 PM
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    How not to pipe a steam header

    Thought I'd post a series of photos of the piping issues JStar will be fixing this week in addition to the Midco burner install.

    When the boiler was replaced in 2009, the oil company installers wanted to do the classic no-no of piping the main takeoff between the risers. I talked them out of that but they still insisted on piping the main run and equalizer in opposite directions. Why? "Because we've always done it that way and we've never had a problem". Mm-hmm. Because you never got called back, maybe?
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    This post was edited by an admin on April 14, 2013 6:20 PM.
  • MarkS MarkS @ 6:02 PM
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    How not to pipe a Hartford Loop

    Here's a pic of the Hartford loop. It may have the world's longest close nipple. And it's below both the LWCO probe and the boiler's minimum water level.

    The wet return in the pic is about 14" off the floor. The wet return at the other end of the house is at floor level, and there's a vertical pipe joining the two just past the takeoff for the Hartford loop. It's odd, but haven't had any problems with it. Maybe it helps keep sediment out of the Hartford?
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
  • MarkS MarkS @ 8:57 PM
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    Mains piping - current and proposed

    Here's a schematic of the current system piping, and a couple photos of the mains and the main tee.

    The mains configuration has me wondering what the Dead Men were thinking when they installed this 120 years ago. It has what conventional wisdom tells us are two big no-no's; a vertical bullheaded tee from the header into the main, and a horizontal bullheaded tee into the mains along the wall.

    The main tee is 3x4x3. To the left is a 3" main serving 362 sq ft of radiation on two 2" branches totaling 95 feet in length. The right side is bushed down to 2" pipe serving the 32 foot long main along the wall with 251 sq ft of radiation. The 4" port is bushed down to 3" and again to 2". The original coal boiler was probably piped right into that 4" port, and the bushings added when old man coal was replaced.

    With the new header, we're going to tempt fate a little here and second-guess the Dead Man by capping the right hand side of that main tee to eliminate the bullhead, and running separate takeoffs to it and the mains along the front wall. The horizontal bullhead on the front wall will still be there; we think it's more trouble than it's worth to remove that tee and have three takeoffs from the header.

    Would appreciate comments/opinions on why it's piped that way to begin with, and/or if there are compelling reasons to NOT split the mains.

    Thanks,
    Mark
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    This post was edited by an admin on April 15, 2013 8:59 PM.
  • MarkS MarkS @ 6:44 PM
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    High drip line connection to return

    This drip line from the northeast main ties into a sloping return from the northwest main about 22" off the floor. When the old coal boiler was in place, the water line was well above this point so it was a wet return, As it happens, the current boiler's water line is also about 22" off the floor, so depending on where you are in the cycle and how much pressure is in the system, this tee is alternately wet and dry. There's usually some water hammer here for a couple of minutes about 10 to 15 minutes after the boiler fires.

    JStar is going to re-route the drip so that it ties into the wet return at floor level, which is off the right side of the picture.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    This post was edited by an admin on April 16, 2013 6:45 PM.
  • MarkS MarkS @ 10:52 PM
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    We have ignition!

     It's been an exciting couple of days here. Huge thanks to JStar and Edison for all their hard work. The de-knuckleheading of the near-boiler piping exceeded my expectations.  Not only did JStar "de-bull" the main tee, he managed to rotate it 90+ degrees clockwise so the steam enters from slightly above and to the left rather than directly below. And that horizontal bullheaded tee that I thought we'd have to leave as-is? Nope. JStar capped that tee and split the main to the left of it. No more bullheads!

    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. Biggest concern was whether my DIY controls would actually operate this burner, but weeks of bench testing paid off. It'll take some time to tune the pressure controller, but overall I'm quite happy with the performance of the system.

    Midco was interested enough in this project to send a rep to "site" (that's my basement). Their man stopped in briefly this afternoon and will be back tomorrow with his combustion analyzer to fine tune the burner controls. 

    Here are some pics of the de-knuckleheading. I'll post pics of the burner tomorrow, and maybe even a link to video of the burner in operation.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
  • Bio Bio @ 7:47 AM
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    Very nice

    Very Nice pipe work in a very tight space, No doubt, Joe sure does a great job
  • vaporvac vaporvac @ 3:37 PM
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    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.
  • MarkS MarkS @ 4:47 PM
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    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.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
  • tim smith tim smith @ 9:11 AM
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    Re: pics etc

    Nice looking repipe, also like your uss Enterprise control panel, the only thing missing is a interstellar out of phase gyroscope. Velly special.   Btw, I had talked to Midc about using that burner in some of our boilers and or new a few months ago. I am looking forward to hear the outcome. Good show.  Tim
  • MarkS MarkS @ 10:53 PM
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    duplicate post deleted

     
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
    This post was edited by an admin on April 18, 2013 10:53 PM.
  • Dave in QCA Dave in QCA @ 7:53 AM
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    Very Nice Indeed!

    Excellent job on correcting the piping!  How about some pictures of that new mysterious burner? I'd be very interested to know how you set it up and how you're controlling it.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • ChrisJ ChrisJ @ 8:11 AM
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    Lookin Good!

    Its nice to see everything coming along good.

    I do have a question regarding your king valve location though. With them in between the boiler and the header you're going to need something to keep it from pushing the water up the equalizer. I'm guessing you installed a valve on the return between the boiler and hartford loop\equalizer?
    Weil-McLain EG-45 connected to 392sqft of radiation via two 2" risers into a 3" drop header and 2" equalizer. Using Rectorseal Steamaster water treatment to greatly reduce corrosion in the boiler.

    Steam system pictures updated 6/5/14.
    https://picasaweb.google.com/thetube0a3/Boiler?authkey=Gv1sRgCImUxIqv9436MQ#
  • MarkS MarkS @ 1:41 PM
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    Equalizer

    Oops, the pic I posted was from before the equalizer valve was put in. Here's the as-installed pic.

    Midco pics and video coming later today.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | Odyssey 2014 | A Steam Enthusiast's Outdoor Reset Control
  • Charlie from wmass Charlie from wmass @ 2:30 PM
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    Next boiler save a valve and avoid a potential problem

    if you install the king valves post header on the system supplies you do not have to worry about the equalizer being shut off and two less joints on the near boiler piping. Looks a heck of a lot better then before though.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • JStar JStar @ 8:30 PM
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    Valves

    Here's the dirty truth...the valves were not in stock the first day. All of the main take offs went together so precisely that when we had the valves the second day, we installed them at their current location. Plus, two of the same sized valves looks more symmetrical. Yeah, that's my story.
    - Joe Starosielec
    732-494-4357
    j.star@thatcherhvac.com
    http://thatcherhvac
    http://facebook.com/thatcherhvac


    Guaranteed performance. Guaranteed energy savings.

    Serving all of NJ, NYC, Southern NY State, and eastern PA.
    Consultation anywhere.
    (Formerly "ecuacool")
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