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Load Bank?

Discussion in 'Electronics' started by Ken Bracewell, Jan 29, 2013.

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  1. Ken Bracewell

    Ken Bracewell Senior Member

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    We've just finished installing new generators and now the contractor has informed be that our new soot filters won't work because we're not getting enough load to get the temperatures high enough!

    You would think that said contractor would have been able to calculate all of this before ripping out the old gear! And, he was the guy who sold and installed the previous units too :mad:

    Anyhow, does anyone have any suggestions for a way to add load (appr. 10-15Kva), or for manufacturers of a small load bank? The pricing from the contractor is appr. $20K before installation.
  2. Capt Ralph

    Capt Ralph Senior Member

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    MAybe it's the rum

    Woa
    Your inquiring into an artificial electrical load, so your generators exhaust will run hotter?
    How large of units are we talking here?
  3. Capt J

    Capt J Senior Member

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    That doesn't sound right. But, higher exhaust temperatures will be created by a higher load. However, creating an artificial load is going to burn more fuel. Who sized your new generators for your application? How oversized are they? How many KW do you typicall use and what size are the generators?
  4. Ken Bracewell

    Ken Bracewell Senior Member

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    99kw

    They're 99KW, and we use between 40 and 70 on a regular basis. Our bowthruster is hydraulic, and the pumps require that size engine to create thrust.
  5. Capt Bill11

    Capt Bill11 Senior Member

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    I looked into this on the 140' I was engineering on with similar size gensets. Not so much because of soot but due to light loading. But between the cost and size of load banks we decided against it.

    Loadbank Power House AC load bank

    I would be pretty pissed if after all that the installer is just now telling you this. Seems like they should have figured that out before they even started.
  6. Ken Bracewell

    Ken Bracewell Senior Member

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    Yup...
  7. wdrzal

    wdrzal Senior Member

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    Fuel oil burns/combusts at the same temperature,(+/- the difference in the air to fuel ratio,compression)the main difference is the flow rate. Higher flow,higher total Btu output but the combustion temperature will be the same.

    And Yes Total heat(btu's) temperature ,CO,CO2,oxygen,excess air(excess air is needed in any combustion process) nitrates of oxide can all be calculated (combustion analysis). So can the heat transfer through any heat exchanger.

    Adding load is going to add unnecessary cost. If you want/decide to add the load through a electracal load bank go to http://www.chromalox.com/ they will have what ever you will need. Their online catalog is extensive, their service is great, Order their free paper catalog. Just reading through it you will give you a education.
  8. rgsuspsa

    rgsuspsa Member

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    Generator Load Bank?

  9. Old Phart

    Old Phart Senior Member

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    I dunno
    Did anyone mention the desired temperature range for the dpf in use or the temperature range produced by the new generator(s)?
  10. Ken Bracewell

    Ken Bracewell Senior Member

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    I believe the optimum minimum is 350 degrees C. We are running about 300. These numbers vary depending on load.
  11. Capt Ralph

    Capt Ralph Senior Member

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    Yep...
  12. Capt Ralph

    Capt Ralph Senior Member

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    40 to 70% load is not enough to achieve the required heat? How close are the scrubbers to the exhaust outlet? I don't have any answers but want to understand a lil bit more and learn something.
  13. Old Phart

    Old Phart Senior Member

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    I dunno
  14. Ken Bracewell

    Ken Bracewell Senior Member

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  15. Capt Bill11

    Capt Bill11 Senior Member

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    70% or above should give you the right temps I would think. But I'm guessing the problem is they don't run often or long enough at those loads to maintain the proper temps for the scrubbers to work properly.

    Here's a crazy, maybe, idea. I wondering if there is any way to put an inline heating element of some kind in the exhaust gas stream before the scrubbers to raise the temps to the proper level?
  16. Marmot

    Marmot Senior Member

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    That is a pretty good overview. We have found that despite the manufacturer's claims, the filters really need a consistent high temperature of 400C or so to function. One problem is that periods of low temperature allows soot to build up then when the filter regenerates, its internal temperature goes very high very quickly and there is a risk of damaging the element.

    Most of them are Cordeirite ceramic that is pretty brittle and subject to cracking from rapid temperature excursions or even melting from uncontrolled regeneration if they are dirty. A nice steady constant high temperature should be the goal.

    The precious metal wash on the elements can be varied according to the manufacturer's spec and may be a mix of metals intended to meet a particular goal or cost. The automotive and trucking applications are drivig the industry and most of the elements are coated to meet US or EU emmissions standards.

    The best way to insure clean exhaust is to match the generator to the load, maintain high loading one way or another, use a fuel oxidation catalyst which not only reduces soot production at the source but also enhances filter regeneration. If you are stuck with a bad match and marginal temperatures, using a fuel catalyst and exhaust heating (active regeneration or "encouraged regeneration") is a practical and cost effective solution.

    Unfortunately, exhaust treatment and combustion enhancement doesn't solve the root cause which we all know is chronic underloading. We can cure the symptoms though and since everything behind the engine room bulkhead is a compromise, it is an acceptable and economical way to keep the air the paint and the water around the boat clean.

    I am particularly fond of the method CaptBill suggested ... electrical heating of the exhaust can be seen as attacking the problem from both sides.
  17. Minnow

    Minnow New Member

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    Hi Ken,

    Yes...the never ending problem of generator emissions. Are your new gens Tier 3?

    Curious what kind of soot filters you are using that are dependent on load/temp.

    Here is a load bank which I have seen advertised (fairly small)
    Technicold.com

    And a soot filter system which works.
    Centek Industries - Gen-Kleen Filtration

    I'm sure there are others as well.

    Let us know what you discover
  18. wdrzal

    wdrzal Senior Member

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    I never could figure out why the industry doesn't move to clean burning propane gensets.:confused: Other than that you already have a diesel fuel tank.
  19. Marmot

    Marmot Senior Member

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    Plus the fact that heavier than air propane gas safety, storage, gasification, control, and availability creates its own rather long list of problems when considering that type of use on a boat.
  20. Capt Bill11

    Capt Bill11 Senior Member

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    I forgot to mention that on the 140' I started adding this product to the fuel: https://yachting.cerionenergy.com/
    and we did see a significant reduction in the soot output of the gensets.