Making a virtue from a vice.

Discussion in 'Hybrid' started by Pericles, Oct 11, 2007.

  1. Pericles
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    Pericles Senior Member

    Charmc,

    Steam locomotives had an thermal efficiency of around 8%, that, in effect means that 92% of the energy in the coal was not turned into mechanical work, but was released to the atmosphere. Andre Chapelon's rebuilds of existing French compound locomotives through the 30s were able to raise the figure to 12%. As a comparison, coal fired power stations get between 33% to 39% by the use of triple expansion turbines and condensers.

    If the waste heat from power stations is sold and used for district heating then that reduces the cost of electricity generation for the utility company Major companies generate their own electricity, then use the steam for processes and the hot water for space heating, sometimes achieving thermal efficiencies of 90%. The http://www.5at.co.uk/ project is working towards 14% thermal efficiency!

    Thermal efficiency in my design would be based upon the steam generating electricity and then using it to warm the boat. However, the used deep fryer oil would only cost me for its collection and filtration and some restaurants pay to have it taken away. :D

    Danish Bagger,

    Try http://www.asterhobby.com/ Have a look at the Berkshire

    The only British commercially available butane fired boiler, that I know of, was used in the three and a half inch gauge Rocket manufactured by Hornby in the 80s. I have one. :D :D :D

    http://www.toycollectors.fsnet.co.uk/rocket.htm

    Now live steam locos from Hornby are electrically fired!

    http://www.railway-models.co.uk/1243_1.html

    The G1MRA http://www.gaugeone.org/ might be able to give you more information.


    Pericles
     
  2. DanishBagger
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    DanishBagger Never Again

    Thanks, Pericles :)

    LOL, at this one: http://www.toycollectors.fsnet.co.uk/rocket.htm

    About the coal fired power stations, I seem to remember that our coal fired power stations efficiency are at about 65 percent. But that it is only so much because it makes both heat and electricity (and loads of technology). Unfortunately it was in an interview on the telly one of the power plant blokes were saying it. Anyways, it's still rather low.

    How about doing what the aussies did, and build a huge array of mirrors, warming up a black bowl of water on a stick (well, that's how it works, anyway)?
     
  3. DanishBagger
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    DanishBagger Never Again

    Btw, what's the point in a electrically fired steam plant? That has got to be inefficient, especially considering how much more energy it takes to make water boil compared to heating it.
     
  4. Pericles
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    Pericles Senior Member

    It's a very small locomotive that runs on an electrified railway track. Power consumption is not very great. During WWII the Swiss put pantographs on steam locos to raise steam, because they could not import coal. It was incredibly inefficient, but they had hydro-electricity. As for power station efficiency, I read somewhere that waste heat is used to raise tomatoes at some British sites.

    I believe all Norwegian power is hydro-electric.

    Pericles
     
  5. Pericles
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    Pericles Senior Member

    From Lars Josefsson site under fuel atomizing methods. Blue Flame Burner. http://www.steamesteem.com/

    In the blue flame burner some of the hot gases from the flame are recirculated back to the inlet where they mix with and heat the combustion air. The fuel oil is, during normal firing, introduced into the hot recirculating gases and vaporizes. When the hot flue gases and gaseous fuel mix with the combustion air it burns with a blue flame without visible smoke. This is the closest to stoichiometric combustion one can get with a commercial burner today.

    http://www.oilon.com/products/

    Here is information about feed water treatment.

    http://www.portatreatment.com/

    Pericles
     
  6. Pericles
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    Pericles Senior Member

    More information about Thoosa 17000

    DanishBagger,

    Something to think about. From Asmo Marine.

    The price for a THOOSA 17000, included Motor Controller is € 5.800,00., then you would need a Throttle, € 499,00 and a battery monitor € 382,00

    All prices are excl.VAT and excl. freight cost.

    On the picture I can see it’s an old single cylinder steam engine, with a flywheel and I would guess the efficiency for such one are maybe max. 70% at max. speed and loaded 50%; depending of how it’s measured. If we assume it’s 70%, the machine will then deliver about 17kW; enough for one THOOSA 17000 full loaded. But you have to take care about the DC output, because this generator, as I see it, don’t have any kind of electronic device for making the 110VDC stabilized, which is needed for our E-Motor controller system, but only a flywheel. That means when the generator are getting loaded, the rotation speed will get reduced (depending of the weight of flywheel) and DC voltage will be reduced. So if no stabilizing, the DC voltage will swish up and down depending of load factor. The motor controller will feel it, as the “battery” is weak or nearly discharged, so after a certain time it will probably close down because it will protect the equipment. . Ok, if we would like to stabilize the DC voltage easily, would it then be possible with a battery bank ?. Yes, it will help, but the problem is that if only the battery bank will be charged with maybe 110VDC (2,29V/cell) or even lower because of no electronic control system, the batteries will never get fully charged and you will experience the battery bank will loose capacity and life time. So you will need to invest in a grid connected 3-step charger also, to get the batteries topped up and in good conditions. A battery bank that should be able to manage the peak power loads for lets say 5~10 minutes, will be very big, heavy and costly. And another thing, if the batteries are fully discharged (75%), the steam generator will feel a that a big load is connected; the speed goes down, voltage goes down for a period of time.

    All modern DC generators are equipped with electric controller systems.

    Regards

    Birger

    The information above prompts me to think about a direct connection between the Thoosa 17000 and the dynamo, so that as the steam engine speeds up, more current is produced and the electric motor responds accordingly. No batteries needed. It seems simple enough, but I bet I'm missing something vital here. Do we have any electrical engineers in the house? :D

    Pericles
     
  7. DanishBagger
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    DanishBagger Never Again

    From what Birger says, it looks like you would need some sort of electronic DC-DC converter to stabilise it. Isn't that basically what he's saying?

    I find this talk rather difficult –the subject, that is. It really is complex, and on top of that, it's in english.

    However, it seems to me, that he's saying that the easy choice would be a modern electronicly controlled generator, _because_ it is electronically controlled.
    From the information that 17kw would be enough to drive the Thoosa fully loaded, then it seems a 25kw modern generator certainly is too much. (think of the electric engine only going at half it's max). From that, I'd propably go for two much smaller generators: 2x10kw, for instance, controlled more or less automatically. That is, unless I could get some fun steam-machine going, of course!
     
  8. Pericles
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    Pericles Senior Member

    Yes, it's no fun with a modern diesel DC generator. It's the steam driven dynamo that I'd want to use. :D

    If there were a voltmeter in the circuit between the dynamo and the Thoosa 17000, just keeping the dynamo output to 96 volts should be all the boat speed control necessary. Am I right?

    Pericles
     
  9. DanishBagger
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    DanishBagger Never Again

    Well, I guess you _could_ be right. That it sounds plausible. But I really don't know.
     
  10. Pericles
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    Pericles Senior Member

    Have learned that a rule of thumb about steam consumption is 25 lbs of steam per hp per hour, thus a 50 hp steam engine requires a boiler capable of raising 1250 lbs of steam per hour at around 175 to 200 lbs per square inch. Saturated steam rather than superheated steam is preferred in order to minimise lubrication difficulties, however a steam dryer to eliminate water carry over could be useful.

    Pericles
     
  11. DanishBagger
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    DanishBagger Never Again

    A steam dryer? Yikes, I obviously need to read up on this stuff …
     
  12. Pericles
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    Pericles Senior Member

    Otherwise known as a low temperature superheater as first fitted to Great Western Railway locomotives early in the 20th century. It was later found that for railway service, greater superheat temperatures resulted in more economic working. Whilst I have books detailing these improvements they are in storage in preparation to moving house. However, the King class information here, http://en.wikipedia.org/wiki/GWR_6000_Class shows that only one superheater element of 194 square feet was fitted, whilst an LNER A3 Gresley Pacific had superheater elements totalling 525 square feet.http://en.wikipedia.org/wiki/LNER_Class_A3

    Later, in their service lives, Kings were fitted with bigger superheaters. Steam locomotives and their performances are a specialist subject with as many opinions as there are enthusiasts. Here is a modern design , which may be built one day. http://www.5at.co.uk/

    Pericles
     
  13. juiceclark

    juiceclark Previous Member

    interesting post

    Since this electric motor turns a belt, it could turn my big prop as a trolling motor allowing me to turn the big engine off. It takes a 17KW motor to run it and puts out about 50hp. Something tells me it won't use must less diesel than my big motor. TC
     
  14. Pericles
    Joined: Sep 2006
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    Location: Heights of High Wycombe, not far from River Thames

    Pericles Senior Member


  15. juiceclark

    juiceclark Previous Member

    yes

    I have a 7.5KW on the boat I use now. I use it so seldom it's more ballast than functional.
    The boat I'm building now is very flat at the transom and should be very fuel efficient:
    http://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/22690

    But I'm trying to learn the most efficient way to move it at trolling speed (5 - 8 knots) other than running the main engine. I've considered two small sail drives, perhaps a small diesel running a hydraulic pump to move the main shaft, etc. The new electronic diesels are pretty efficient near idle...so I'm growing skeptical that these other "alternative" power sources will actually save me money.

    Tony
     
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