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Air-Electric Drive System

Discussion in 'Technical Discussion' started by TRY, Oct 23, 2006.

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  1. TRY

    TRY Senior Member

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    Hi all,

    This reply is a bit aside from the main "diesel-electric" discussions, but it fits well within the alternative-drive philosophy.

    With a small team of thermo-dynamic engineers we're currently working on an "air-only" or "air-electric" drive solution.

    In the "air-only" solution - which we will first apply to catamarans, because they're much less power-hungry - 2 compressed-air engines will drive the props via shafts.
    The engines run since more than 5 years in a car, a genset, a mini-tractor, etc.
    We plan to install 2 x 25kw engines in a 40-45 ft cat by next summer (in Europe).

    In the "air-electric" solution the main drive will come from electric motors, with electricity being supplied by one (or more) compressed-air gensets.
    This solution will apply to larger vessels, first stage will be a 65 ft cat.

    In both configurations range will be increased by heating the compressed air between tank and engine with an external heater-burner, using any kind of fuel, at a rate of 2-3 liters / 24 hours.

    Interesting?;)
  2. K1W1

    K1W1 Senior Member

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    Hi,

    Try ,how do you plan on getting your motive force (compressed air)in the first place?

    How large are your Air Receivers going to be and at what pressure will these be maintained or charged up to by your compressors?

    Lets face it the calorific value of 2-3 lts/24hr of "any kind of fuel" is not going to be enough to expand much compressed air if it is required to deliver 50 kW of power through Air Motors.

    Nothing is for free in this world. You will have to expend energy in the form of some type of fuel driving reciprocating or rotating machinery to compress the Air in the first place if you are going to do it onboard to enable the boat to cruise further than the length of it's air hose or shore power cable from the dock.
  3. brian eiland

    brian eiland Senior Member

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    Air-Motor Power

    Makes me think of those air starter motors for some truck diesel engines and/or air motor tools....not very quite, nor efficient, nor long lasting without lots of maintenance
  4. K1W1

    K1W1 Senior Member

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    Hi,

    I apologise if my questions don't seem to be polite to you.

    Brian you are right in your recollection of diesel engine starters and air tools these rotary vane type motors are noisy and sadly have a short service life( approx 1500 hrs) even shorter if not properly lubricated when in service(approx 500 hrs).

    I am always keen to expand my knowledge and embrace new technologies, I will be waiting with baited breath for the expanded explanation of the system that TRY has given us a teaser of.

    Hopefully TRY will be able to kick this off by answering my opening questions in my first post on this subject.

    Carl, Maybe you would like to move this and other posts related to TRY's new propulsion package to their own thread to avoid confusion as it seems to have deviated somewhat from the original thread theme.
  5. YachtForum

    YachtForum Publisher/Admin

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    Guys,

    This discussion has been moved under it's own heading, seperate from the Diesel Electric Propulsion thread... in order to maintain subject continuity. Interesting thread. Look forward to learning more. :)

    I'm off to a big flotilla of boats for sale. Good week to all!

    Carl
  6. TRY

    TRY Senior Member

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    Some indications

    Engine "fuel": air
    engine power (at this stage): 25 kw
    type: flat twin (boxer)
    weight: 32 kgs
    tank type: compressed air 300 bars (multiple tanks possible)
    working pressure: 30 bars
    refilling: by compressor-side of the same engine, when connected to mains.

    Pls forget existing air-tools and the like.
    This is brand new, fully patented technology.
    It works.

    I'll keep you all posted.:)
  7. K1W1

    K1W1 Senior Member

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    Hi,

    Thanks for your answers.

    If I understand correctly you are intending to charge the Air Receivers whilst at the dock and then cruise around on this stored air.

    Can you please confirm if this is what you intend to do as it is not 100% clear in your post above how you intend to raise the pressure of the Air to 300 Bar.
  8. TRY

    TRY Senior Member

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    Compressor = engine

    When powered by mains the engine acts as a compressor.
    More cannot be said at this time.

    For longer endurance electric motors will drive the prop with an air-genset producing the electricity via a dual-energy air-motor.
    Again that's all to be said for the time being.

    Advantages:
    - 75% (economical) economy in fuel (at today's average fuel costs)
    - 100% clean (rivers - lakes - canals)
    - weight (especially critical on a cat) with 10 kw engine (complete) at 12kgs and the 25 kw at 38 kgs complete; improvements expected with many plastic parts instead of today's development in alloys.
    - 6kw genset complete at 66kgs
    - volume: 10 kw is approx 400 x 250 x 150 mm
  9. wdrzal

    wdrzal Senior Member

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    TRY

    I wish you all the best and a revolutionary efficient drive solution.

    But what I know about mechanical engineering and gases & hydraulics tells me to tell you to fire your engineers. I hope I just made a wrong statement and I'm to old to understand your solution.

    Hmmmm I just looked at your public profile and I made another wrong statement,you are my elder.

    lets hope 2 wrongs make a right, good luck !!!;)
  10. TRY

    TRY Senior Member

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    No!

    Dear Wdrzal,

    No, the engineers will NOT be fired, but thanks for the advice.
    We're not discussing an engineering phantasy or a technical dream.
    As I stated before: this engine runs!

    But I accept that anything beyond known territory is likely to be rejected as nonsense.

    Stay tuned as they say!;)
  11. MacMcL

    MacMcL Senior Member

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    Try,

    I have no doubt that your new concept runs, but at what efficiency? You are using one source of power to compress air and then using the compressed air to run another source of power. Good Luck, it sounds like you will need it.
  12. TRY

    TRY Senior Member

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    About efficiency:

    We have run comparative models of alll and every available "fuel", from it's source untill the exhaust of the "engine", in comparable "vehicles".
    Overall (but then I will have to prove this, I suppose) we come out as most efficient; only electricity can be produced more economically, but then the "vehicle" is much heavier due to the weight of the batteries.

    Having said this, I must admit to a certain disappointment about the reactions received so far.
    I thought this community had an interest (certainly in this technical section) in very complicated machines we call yachts.

    All replies show either disbelief or compassion.

    In other fields of application - be it automotive or industrial - we enjoy a lot more enthusiasm.
    But then, yachting - in line with aviation - is a very conservative environment.

    I'll keep you posted and I'll reply - within reason - to your questions.;)
  13. Castlerock

    Castlerock Senior Member

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    Courious and quiet

    Try,

    I am one of probably many people who are just waiting for the engineering and design to be presented before commenting on the system. I am anxoius to see what you are working on and will wait untill you are ready. I am for a new propulsion design, I have done a few different ones myself but nothing like what you described.

    Carry on, without innovation we have no future.
  14. wdrzal

    wdrzal Senior Member

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    After I see more details,I can evaulate the direction your going better and maybe be able to give you advice or explanation of why or why not part or all of your design will or will not work..I do hope ,Sincerely, you are on the right track for a break thru.
  15. C4ENG

    C4ENG Senior Member

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    Try
    Can you tell me if I have this straight?

    You will have a diesel engine attached to an air compressor.

    The air compressor will then feed a storage tank.

    The storage of compressed air will then be used to turn a genorator.

    The genorator will then produce electricity to power two electric motors to propel the vessel.

    It is a little bit difficult to follow the small bits of info here and there you have written. I can see how people (myself included) could be suspect to the fact of some one not being true when they lay down the info in an hard to follow spotty manner. But you have caught my interest.
  16. K1W1

    K1W1 Senior Member

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    Hi,

    I will attempt to explain what I understand of the Air/ Electric Drive he is talking about.

    As we don't know if the intended current is AC or DC I have used the terms Alternator/Generator to indicate that it could be either.

    From what I understand the Alternator/Generator that will power the drive motor is itself used as a motor when connected to the mains to charge the receivers. The motive force here being electricity from the mains

    It and the motors roles are reversed when what was initially the compressor now becomes the motor driving what had initially been the motor which is now converted to Alternator/Generator which supplies the electrical driving force to the motor attached to the shaft. The motive force being the air that was compressed and stored in the first stage

    TRY, please don't be afraid to correct or clarify this as you have piqued many peoples interest here and we all like new and interesting ideas.
  17. TRY

    TRY Senior Member

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    I'll TRY

    A few flow-charts to TRY and explain more clearly than the bits and pieces mentioned in earlier posts:

    compressed air stored in tanks at 300 bars (could be more in near future)
    >>> "engine" (no combustion but uses pistons-rods-valves-crankshaft) at 30 bars >> drives anything (gearbox, genset, prop,etc).
    available now are 10kw and 25kw units. up to 200-300kw in 22-24 months.

    mains (220-110) >> drive compressor-pistons of same "engine" via an electric motor to compress air >> air tanks.

    to facilitate the filling of the expansion chamber at higher revs (comparable to combustion chamber in a classic engine), the piston is stopped at top during 40% of crankshaft turn (crankshaft keeps turning of course).

    overall "cost" = 25% of comparable diesel engine (75% economy, exactly!);)
    no toxic emissions.
  18. TRY

    TRY Senior Member

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    One more detail

    to get all engineers' brains cooking!

    to improve the "work" part of the crankshaft-turn to 270° (yes!) the latest generation of "engines" now use 2 pistons (of different diameter) on the same crank. ;) ;) ;)
  19. Castlerock

    Castlerock Senior Member

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  20. TRY

    TRY Senior Member

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    Exactly!

    That's exactly what we're doing and who we are!
    Any further questions still?
    I'll reply.