Any such thing as small steam turbine ?

  1. Any such thing as "small steam turbine"?

    I've a C-Band satellite dish. I'm going to attach 2" mirrors to the entire reflecting surface and aim it at the sun. Where the feedhorn was, I'm going to design some type of coil to pump water through which the focused sunlight will boil the water producing steam.

    Now, what can I do with the steam?

    I'd like to have it power a small steam turbine - attached to a small generator - maybe just enough to light a 12volt bulb, just to prove to myself that this can be done. Is there such a thing as a small steam turbine? Is there one that I can just buy as opposed to having to engineer one from scratch? (my Solidworks programming skillz stink)
     
  2. jcsd
  3. FredGarvin

    FredGarvin 5,087
    Science Advisor

  4. small steam turbine

    I'm working on producing 1kW, 5kW and 10 kW bladeless slotted disc turbines.
    You can read my original writeup on the following website:

    www.green-trust.org/steamturbine/steamturbine

    I have a robust protype that has only been tested with compressed air that works as expected. I need to build a steam generator next.

    Another paper on Solar Steam Generation will be posted on that website soon.

    I would be pleased to hear from you.

    Bob Saunders
    nwwpa@yahoo.com
     
  5. Why not use a Stirling engine? Been done before aswell...
     
  6. I've wanted to do a similar idea with a copper coil that would attach to like a backpacking stove for instant hot water, but your idea is quite cool. Well, youd need to have the coil be fairly large actually to account for the necking down youd need to do to get any substantial pressure. If its just for a proof of concept, make a simple turbine and attach it to an alternator (the base for many homemade generator plans) Good luck and cool idea
     
  7. Yes small turbines exist - they are widely used for auxiliary power in facilities which have steam readily available. Dresser-Rand currently lists several used units in sizes starting at 8HP 1300 RPM on their website. Even used they are not cheap. Check junkyards around areas which have industries using steam or plants being demolished and you might pick up a rebuildable unit for scrap prices. They are also widely used in marine applications, so if you have any contacts around shipyards or ship refitters, you might get something there. You might even find one with generator and governor already attached.
    A note on the comment about 'necking down to achieve the pressure': the pressure in a system like this is set by the feed pump, which will consume significant amounts of the produced power output. Feed pump forces cold water into the coil, where it turns to steam. Positive displacement feed pump must be able to overcome the back pressure of the turbine in order to maintain the required hot side pressure.
    Another note: you can useable amounts of steam from a simpler horizontal parabolic / tube heater and it will have less stringent tracking requirements. Tracking with the dish will be a constant process reguiring automation to get anything approaching continuous duty, while the horizontal parabolic reflector needs only minor seasonal adjustment to get useable heat all through the day and the adjustment can easily be done manually.
    All in all though these thermal solar generation schemes are way more cost effective than photovoltaics. Be aware that there are lots of safety regulations relating to steam (you might want to familiarize yourself with them in the interest of personal safety...) and it is probably best to say it runs on hot water if you don't want a bunch of officials breathing down your neck.

    I have often wondered whether an automotive or truck turbocharger hot side might be made into a cheap but probably inefficient steam turbine -- but that is another project altogether. The turbos used on Cummins four cylinder diesels look to be a nice size to drive a high ooutput auto or bus alternator and it is relatively easy to get at the shaft.
     
    Last edited: Jan 29, 2008
  8. Solar Hot Water Evacuated tubes

    Hi,

    I'm enjoying your thread on Steam engines / turbines. Has anyone explored the merits of the solar hot water heaters (evacuated tube type) in conjunction with bio-mass, etc. The thought would be to use the Evac tubes as a pre-heater and then super heat the water to steam with minimal added thermal energy to then drive a piston or turbine. I first started thinking about using a concentrating collector to generate steam and drive an engine, but then thought about the potential to heat up the water first and then require minimal added energy to refine water to steam.

    Thanks,

    Jbemory
     
  9. Not quite sure what you mean by the 'evacuated tube' solar hot water heater. I have heard of some installations using an evacuated tube to insulate the collector tube in trough type parabolic collectors. But my limited experiments with the trough type collectors and plain black pipe tubes is that you get a lot of raging hot steam out of one of these things on a sunny day even without insulation on the collector tube. I would think for small scale experimentation or power generation that adding a few feet more collector would be much easier than fiddling around with a two stage system.

    As far as biomass is concerned, I think we are in two pretty different regimes here. The heat generated by biomass or that required to enhance methane production from same is mild compared to the heat from a trough type parabolic collector. It would require careful control if one used a trough collector to heat a biomass plant, to avoid sterilizing the mix with way too much heat. Probably a flat sheet metal and glass collector as used for heating swimming pools is the best match for heating a biomass plant.
     
  10. Any examples of this? I'm considering a project like this. I'm thinking of using a parabolic trough mirror to heat a black iron pipe suspended across it at the focal point. The water(might have to use other fluid due to temperature.) within this pipe will be fed in a closed loop to the hot side of the stirling, while another pump will pump cold water from my pool to the cold side of the stirling. I'm a mechanical engineer, but kind of clueless on stirlings. I understand their operation and the use of the regenerator, but not up on the most efficient designs, or important stuff like just how much more efficiency do I get if I do this versus that. That is the kind of stuff I'd like to know because often a slight change in design can lead to much better results, or conversely one can spend orders of magnitude more work on something to make it in theory more efficient while yielding only a small gain that really wasn't worth the trouble.

    Has anyone here built a sizeable stirling, or does anyone know of a good forum for people building serious Stirlings? I've seen so many of the websites about the toy engines, or very small engines, but I am planning on something capable of consuming about 2KW of energy from the hot water.(almost 3HP)
     
  11. I would like to get involved with a project. If anyone is interested in collaborating I can offer expertise with digital control system, ie labview programming, valves, sensors, etc... I am especially interested in solar boiler systems.
    I do have a question though. Why do most designs encorporate reflected light concentrated onto a black body? Would a lens focused into a closed container have benefits over this system. I would think that certain wavelength could be trapped in the container and maybe higher wavelengths could be lowered into the hotter radiation frequencies (IR). I am just curious, and would like to know about experiments with other types of collectors.
     
  12. Something else about steam turbines I have come across. On the exhaust side a vacumm is created by condensing the steam. This acts like a diffusion pump, especially efficient on the last stage of buckets (L-0) where the largest pressure drop occurs. I am not sure if this could be incorporated into the stirling engine design, but i thought it was interesting when I first learned of it:)
     
  13. re solar generator

    I am fascinated by this concept. Here is a link to one website I like. Look towards the bottom of the page for links with some info on constructing such. Unfortunately, the technical details are lacking... http://xenotechresearch.com/cgi/wp/index.php?cat=8
     
  14. small steam turbine

    Hi
    Any progress with your idea?
    Sounds very interesting and I'd like to see pictures in your site.
    Thanks
    Yaya1
     
  15. Re: small steam turbine

    I would like to read about your steam generator info. thanks.
     
  16. Re: Any such thing as "small steam turbine"?

    I'm not sure if this subject is still active, but I appreciated the information as it was "exactly" what I was looking for. Kground, I've looked and looked for small turbines, that do a reasonable amount of work, and found zip. Your site recommendation was right on target. Appreciate that piece of info.
    MIC, my weakest point on this issue is auto controls. I'd love some input from someone who knew the finer aspects. Also I'm a ham, and before moving did quite a bit of Moon Bounce, (EME) with a 1800 lb, 15' dish, (that weight is also with the counter weights). I pointed it with a TV camera, which is labor intensive. I have not put it up again because I want it to be computer controlled within a half of a degree. Anyway, if you see this, I'd like to pick your brain.
    I spent 35 years in the power generation industry, but that was running up to 1200MW machines. I'm now retired, live in a farming area on 4 acres, where you can see horizon to horizon.
    For the past year I've kicked around making either a steam car, or a 10KW generator connected to the grid. In fact that is how I stumbled on your posts, through Goggle.
    My only problem with a site generating plant is the concentrator pipes freezing, hence the draining and refilling bit. Other than that, it is either a steam plant, or buying a wind generator. Wind generator is good, but this area is considered marginal on payback cost. Solar generated steam also has more potential power capabilities. Solar panels are almost twice the cost of a wind machine of the same KW. So I was kicking around the solar steam bit. If any of you happen to still be interested in this idea, let me know.
    Boab
     
  17. Re: Any such thing as "small steam turbine"?

    yes ther are small turbines you will probible be perdusing wet steam and this wares on a reguler turbine but i seen a tulsa disk turbine that work for wet steam and can be ran off the steam produced in a tin can
    and as for the frezing of the solar boiler you can heat sintetick oil and use this to boil the water or you can use a drane back system that can tell when the temp drops belo 32 f and dranes the water into a storige tank that wont frezz
    some good ideas hear keep it up
     
  18. Science fair project

    I'm doing a project for a high school science fair and it involves a steam-driven turbine power plant. I would like to build two models: one demonstrating the workings of a normal power plant and another which will not release steam but will condense it and reuse it (don't ask how, it's a secret), therefore being better for the environment in three ways:
    1. It will not waste water.
    2: Water vapor is a greenhouse gas, so this will slow down global warming, if only very slightly.
    3: The steam that is released in a normal plant must cool from well over 100 degrees Celsius to the temperature of the surrounding air, thereby warming the atmosphere. If the steam is not released, it will only have to cool to just below 100 to condense, therfore releasing less heat and, again, slightly slowing down global warming.

    Anyway, I'm not very experienced with building power plants, and I could use some advice, so if you have any ideas, such as what materials I should use or where I could get them, I would appreciate your help.
     
  19. Re: Any such thing as "small steam turbine"?

    a large scale power plant has blade turbines they are hard to make without a cnc. but the tulsa can be bilt of large washers you can find at the hardware store and a bolt or thredid rod. her is a link to give you a idea of what it is http://en.wikipedia.org/wiki/Tesla_turbine
    or you can look at the book
    The Tesla Disc Turbine ISBN 0-9536523-2-7
    your in for a big project good luck
     
  20. Re: Any such thing as "small steam turbine"?

    Another good off the shelf turbine is a auto turbocharger. The problem is it won't like wet steam and it requires reduction gear to get power out.

    I begin to wonder what kids are being taught in school these days. Water Vapor is a greenhouse gas? Sure, but if you honestly think man has ANY control over the amount of water vapor in the air you are sadly mistake. It's not like we evaporate it and it stays up in the sky.

    Steam is not released in a normal power plant. The water is condensed and reused. The only exception to this is cooling towers seen on some power plants. These are not releasing steam but rather running cool water over a heat exchanger that then evaporates. It's rather usefull when no natural heat sink such as a river or lake exists.
     
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