Making a high efficency 3 Kw DC Generator

Discussion in 'DIY Marinizing' started by kistinie, Mar 8, 2009.

  1. kistinie
    Joined: Aug 2007
    Posts: 493
    Likes: 8, Points: 0, Legacy Rep: -74
    Location: france

    kistinie Hybrid corsair

    Take care !
    It is just like drugs...You start with a beer, finish in a carbon racer with solar panels, windmill and lithium batteries :)
     
  2. kistinie
    Joined: Aug 2007
    Posts: 493
    Likes: 8, Points: 0, Legacy Rep: -74
    Location: france

    kistinie Hybrid corsair

    Running a diesel without flywheel ?

    Does anyone knows if a 400cc 7 Kw monocylinder diesel (1GM10 yanmar by exemple) can run without the flywheel, so with just the generator/motor connected to the crank ?


    Minimum rpm can be 1500/1800 Rpm as the use is generator.
    A good damper pulley can be added on the crankshaft to clear vibrations.

    The idea behing this is to save 15 Kg...

    Of course you will tell me how do you start it ?

    So here is the second question :

    Can an 5 Kw electric BLDC motor with the controler, without reduction, directly connected to the crank can start a diesel ?

    The idea behind is to get a light and inexpensive generator...
     
  3. marshmat
    Joined: Apr 2005
    Posts: 4,127
    Likes: 148, Points: 0, Legacy Rep: 2043
    Location: Ontario

    marshmat Senior Member

    Without the rotational inertia of the flywheel, a single-cylinder diesel will not run very well, if at all. The connected equipment would have to be heavy enough, with enough rotational inertia, to compensate for the loss of the flywheel. I don't really see much of a point to this line of reasoning- if saving 15 kg is that critical, forget about diesel and find a ten-horse Honda gas engine.
    May I ask what, exactly, is a 5 kW BLDC motor doing connected to the crank of such an engine? That's an awfully expensive motor and controller, to do a job that could be done just as well and at much lower cost by a couple of big alternators.
     
  4. masalai
    Joined: Oct 2007
    Posts: 6,823
    Likes: 120, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    kistinie, a German? product that I hope to use - try googling "Torqeedo" there is 2 models that may suit you at 2000w and 4000w peak draw to deliver 6 to 9.9 hp equivalent hp - talk is that will soon be able to regen and when not needed just tilt up as one would for an outboard... Australian website http://www.torqeedoaustralia.com/To...les/CruiseRemote_4kW_1pager_US-letter_fin.pdf will get you the product in pdf - it has the German head office at the very bottom...

    If you are determined to use a small gas engined genset there is a honda based one http://www.olbis.com.au/ap_template/subcat_generators.asp or in diesel http://www.onsitepower.com.au/products/marine/dc100m.htm sorry no European websites but I am sure you could find a local source. The Kubota has a good reputation as does the honda and parts are everywhere...
     
  5. Fanie
    Joined: Oct 2007
    Posts: 4,603
    Likes: 170, Points: 63, Legacy Rep: 2484
    Location: Colonial "Sick Africa"

    Fanie Fanie

    Sjeees... 6 pages and you guys haven't figured out an efficient genny.
    How big is a diesel ? On some cars they are integrating the starter motor to double as an alternator, however, this is not the thing anyone can just bolt on to the motor and you sail off into the sunset. It is specially and carefully designed to do that and is only a recent development.

    A 5kW BLDC motor is a big mawer and as Matt said friggin expensive. A starter is designed to produce high torque for a short time. An alternator is designed to only generate power, all the time. A motor does generate some power, but the energy required to use it as a generator makes it unefficient.

    There is a reason the starter doesn't double as a generator. Usually if the motor has high torque characteristics it generates less power. If it generates more power the torque may be up to...

    He he.. if you don't believe me swap the starter and the alternator in your car :D

    There is no real efficient way of generating power or energy that is commercially available...
     
  6. masalai
    Joined: Oct 2007
    Posts: 6,823
    Likes: 120, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    OK fanie I did not see the part where a starter-motor was used as the DC generator, but some maring electric motors have regen capabilities when the screw is put into the flow whilst the boat is under sail-power - "re-epower" and I think "FischerPanda" & "PolarPower" as well as "AfricanCats", have that option in their pulse-mode electric drive motors.

    I think the lady was after a small cheap petrol/gas air cooled wet exhaust DC genset up to 4000w at 48v to charge batteries on her lightweight small trimaran.

    I also am looking for same but for me liquid (seawater) cooled diesel and preferably using the FischerPanda or PolarPower alternator 12 or 16 poles brushless direct connect "replacing" the flywheel (as is done by PolarPower & a 2 cyl volvo engine now) on a 902cc Kubota 3 cyl diesel for 8KW peak at 48 V DC nominal to charge spiral wound AGM style batteries, for house and primary propulsion (2 x Torqeedo cruise 4000W units).... Otherwise I will have to settle for the less efficient 24v truck alternators set in series to give 48V and off a v or flat grooved belt system (a pair of smaller engines with 2 x 24V 166 - 200A alternators? can that be done? )
     
  7. kistinie
    Joined: Aug 2007
    Posts: 493
    Likes: 8, Points: 0, Legacy Rep: -74
    Location: france

    kistinie Hybrid corsair

    i was thinking of diesel as i already own 2, 1GM10 yanmar in good working condition

    Reason of BLDC+controller is to have regulation of current and the starter function. This combination will give a true "inverter generator" for very low additional cost

    Looking closer to my diesel, without flywheel, unnecessary bits... and flywheel carter ... the 1GM10 equipped in running order goes gown to 55 Kg

    Of course i agree, an electric start Honda motor is a great choice with just 28Kg.
    this kind of very light diesel could be a solution too
    http://secure.genquip.com.au/specsheets/pdf/186E.pdf

    Torqueedo is fine, but quite expensive and is using high speed motor that brings me a few interrogations about longevity and also i really think a CPP is compulsory for regenerating on boats like mine going most of the time over 12 Knts.
    it seems impossible to do regeneration and propulsion with the same pitch if your ship sails 2 to 3 times faster than it motors.

    48v alternator exists, no need to use two 24v :
    http://www.electrodyne.com/models.html
    others can be found from Leroy sonner



    http://www.polarpowerinc.com/products/generators/2-3,5kw_propane.htm
    with this
    http://www.polarpowerinc.com/products/heat_exchanger/heat_exchanger.htm
    Perfect !
    Maybe not on propane as my ship configuration is too dangerous to stock propane

    Exactly what i was looking for...
    to be perfect i would like a fuel injection instead of a carburettor.

    Just need to find a little more $$ €€ but total price could be under 4000$
    Many thanks Masalai !
     
  8. masalai
    Joined: Oct 2007
    Posts: 6,823
    Likes: 120, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    Do you have more information on the torqeedo r4 or r2 series like detail on the drive units and any other specifications beyond the pdf link? I have seen the r2 (very light and appropriate for my boat design - which has a maximum design weight of 4800kg at 11.9m x 6.2m cat)

    On a diesel you MUST have a flywheel - preferable to the weight of the original manufacture or more as Marshmat suggested and Fanies advice (stater-motor / generator are NOT congruent in one unit. - lighter weight is achieved with each part doing its designed function separately...

    Can you weld (or do a training course, which has as a component at a "skills development college" to make something useful - and make your wet exhaust (what is shown is an exhaust gas heat exchanger - slightly different function) but both can be made with expert tuition in a training session....

    Polar Power has nice stuff, but their website is very-much out of date as the Lombardini diesels and lots of other stuff is not available???????? Wake up America...

    Be weary of the high speed diesels single cylinder as they are basically 12month throw-away - shake themselves apart and very noisy (I do not know the ones in your link) - but the ones we used in PNG, were from China, cheap and justified on basis of low cost during exploration for minerals, then sell/dispose...

    Thank you for the electrodyne link for alternators - I don't know if they are carried by any distributors/OEM's in Australia????
     
  9. kistinie
    Joined: Aug 2007
    Posts: 493
    Likes: 8, Points: 0, Legacy Rep: -74
    Location: france

    kistinie Hybrid corsair

    A diesel CAN be started by a generator just the way i imagined

    http://www.steyr-motors.com/products/pdf/hybrid.pdf

    Bad news if flywheel is compulsory on diesel...it is not going in the weight reduction direction i was looking for

    On petrol race engines flywheel it is optional !
    i run TR3 2.4Liter engine (Massey Ferguson Tractor engine from Standard) with a 4 or 6 Kg (done long ago not shure) aluminium flywheel...

    And by the way, a motorcycle high performance 125 to 250cc scooter engine redlined 5/6000 Rpm, used at 4500rpm (that should be max torque) could be a smart solution to improve Watt/weight ratio of a generator
    Runs with fuel injection, weight nothing, part available worldwide
    With good synthetic oils, high speed engines last for long.

    I weld TIG/MIG so i could make my own exhaust.
    i think it also could be done just by machining titanium tubes for a very moderate price
    Titanium can be cut, drilled, and milled with SS316 tools and speeds. No change, just the tubes to pay 45€/Kg for grade 2 (density is 4) so metal will cost 5 times more and if no welding is possible labour will be the same.




    About torqueedo, i will have a look but i recall the best i found was on a Belgium site giving more info.
    you can write directly as they also reply to questions very kindly

    For a 5 tons cat, with low windage, two 5Kw engines should be ok, but i underline that i am now certain that looking for a good CPP is the very best investment for an electric propulsion/regen on a fast cat or tri

    About Polarpower site is last revised in 2005 just like price list...Are they out of business ?
     
  10. masalai
    Joined: Oct 2007
    Posts: 6,823
    Likes: 120, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    Neither have responded to emails yet (sent a week ago)... Australia is too hard/far away?
     
  11. kistinie
    Joined: Aug 2007
    Posts: 493
    Likes: 8, Points: 0, Legacy Rep: -74
    Location: france

    kistinie Hybrid corsair

    Rather too far ...from reason and mankind

    http://www.theatlantic.com/doc/200905/imf-advice

    Short term behaviour, fast money big profits only, for friends mainly.
    The 15% you give to fund hedges will not go in research and development ...what we exactly do here.
    No time, no money to loose with guys like you and me.
    Futur ? They do not care, they will serve us the same soup, the same GM 3 tons truck till 2020 if possible


    We all have the same problem as long as we deal with one off project and new behaviour

    Even a builders like Tournier
    http://www.tourniermarine.com/
    Do not get answer when they ask info for their 70' hybrid project...

    Come back to torqueedo with a 500 units boat project, they will be your best friend.

    To be honest, i am fed up with this general attitude so i now avoid manufacturers too tired to answer questions and start to think about manufacturing my own products :)
     
  12. Fanie
    Joined: Oct 2007
    Posts: 4,603
    Likes: 170, Points: 63, Legacy Rep: 2484
    Location: Colonial "Sick Africa"

    Fanie Fanie

    If you buy a gen set you have to decide what it is that you buy.

    Most gen sets output 230V AC, which is ok if you run mains things. On a boat if it is 24V then it would be better to get a 24V gen set.

    4000W at 230VAC = 17Amp
    4000W at 24VDC = 166Amp
    4000W at 12VDC = 330Amp

    Quite a bit of difference between their current capabilities. If you would be happy with the extra weight of a transformer, go for the 230VAC gen set, you can have 230VAC, 24VAC and 12VAC. You will have to get a rectifier and some smoothing to make the low voltages usable.
     
  13. steele m.a.
    Joined: Dec 2007
    Posts: 44
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Victoria B.C. Canada

    steele m.a. Designer/Engineer

    Hydraulic powered alternators are probably what you need . They are either 12V 24V , or , in your case 48V DC , but they are specialty sealed units .
    They are powered by , oddly enough , a propellor at the end of a line ,
    which is left trailing behind the boat . They can cost upwards of $2,300.00
    because they are above deck - in the elements . An alternator on an engine
    needs a certain RPM to generate electricity . Maybe 1,200 -1,400 RPM .
    It needs a constant application of this . If you stop rotating it , or
    it slows below charging RPM , it doesn't produce any charge at all .
    Unlike a fixed magnet generator , an alternator uses field EMF interaction
    to generate charge . The field charge (from battery) must be there , and
    the RPM must be there . A rare earth (magnetic) generator doesn't need
    a charge present to generate , and also doesn't need high RPM's like an
    alternator does . A fixed magnet generator needs lower RPM , and will
    charge a system that is completely depleated . It sounds as though this may
    be what you need . I'm assuming that you're trying to avoid situations
    where your radios and lights no longer work because your battery is depleated
    from long applied loads .
    markalfredsteele@yahoo.ca
     
  14. kistinie
    Joined: Aug 2007
    Posts: 493
    Likes: 8, Points: 0, Legacy Rep: -74
    Location: france

    kistinie Hybrid corsair

    No compromize

    :!:
    No i can't accept a transformer or any other heavy solution
    i am rather in a kind of spirit to cut my tooth brush's handle ...

    i already have a trailing generator
    Great for safety, but maladapted for long term (sharks, sae weeds, plastics bags...)

    Rpm just changes frequency, and as i produce DC current...no problemo

    Polar power is a perfect exemple of what i am looking for
     

  15. apex1

    apex1 Guest

    its a pity

    Matt, Masalai, Fanie: your valuable contribution to this thread is just a waste of time. This guy will never comprehend that his ideas are just phantasy. Nor does he accept your input if the result is´nt as he likes it to be.

    and: "machining titanium tubes for a very moderate price"
    or: "i underline that i am now certain that looking for a good CPP is the very best investment for an electric propulsion/regen"
    or: "BLDC+controller is to have regulation of current and the starter function. This combination will give a true "inverter generator" for very low additional cost"

    show very clear, this bloke asks for high tech at bargain prices and he will not accept technical restrictions or contradictions. He will continue to ask his idiotic questions as long as one answers.

    He´s replacing a reliable, cheap, low weight Diesel with a electric propulsion and CPP system to save weight and cost (installation and operational). And if thats not possible (as many of us told him in the past 6 weeks), well he opens another discussion `cos he likes to make it possible.
    He is a proven ***** thats all, do´nt waste your precious time.

    Regards
    Richard
     
Loading...
Similar Threads
  1. graywolf
    Replies:
    5
    Views:
    2,795
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.