Supercritical CO2 (Liquid Carbon Monoxide Steam Turbine)

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by Doggzilla, Jul 21, 2019.

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  1. Jul 21, 2019 #1

    Doggzilla

    Doggzilla

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    In another thread the topic of new supercritical steam turbines came up and I thought this deserved its own thread.

    A new type of steam turbine (From industrial giant GE) which replaces the water with CO2 has been shown to produce 10,000kw from a small tabletop turbine. The total weight and size of the system is dramatically reduced.

    This is due to the fluid density being so high under such pressure that it can use a turbine designed for fluid instead of gas.

    https://www.ge.com/reports/call-eco...ed-turbine-generates-10-megawatts-fits-table/
     
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  2. Jul 21, 2019 #2

    Vigilant1

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    CO2 is carbon dioxide.
    So, to use this in an airplane, we just need a tank of liquid CO2 (which isn't our fuel, just a working fluid) and a way to heat it to very high temperatures (that's where we'll need the fuel). Then we can benefit from this efficient turbine. Easy!
     
    Last edited: Jul 21, 2019
  3. Jul 21, 2019 #3

    henryk

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    -turbine is very exciting...+source of thermal energy ,high temperature .

    (hydrogen ?)

    BTW=superFLYWHEEL is very good kinetic energy accumulator=light,allmost 100% efficiancy, no need in chemical reactions !

    https://www.kest-gmbh.com/prof-dr-nurbei-gulia
     
    Last edited: Jul 21, 2019
  4. Jul 21, 2019 #4

    Doggzilla

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    This theory actually works with steam as well. The reason they use CO2 is that above 2000psi it is superior in efficiency to steam.

    The only difference is that instead of having a vacuum condenser and a heat exchanger afterwards...it just recycles waste heat immediately and keeps it at high pressure.
     
  5. Jul 21, 2019 #5

    Doggzilla

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    It can be done with pistons as well to get the proper RPM. And it can use steam under 2000 psi. CO2 is only more efficient above 2000.
     
  6. Jul 22, 2019 #6

    pictsidhe

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    It's a bit of a stretch calling it a steam turbine. Increasing the working fluid density is not a new concept. Closed cycle engines do have some advantages, but low total weight is not usually seen as one of them. That's why you only find them in power stations and boats.
     
  7. Jul 22, 2019 #7

    Doggzilla

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    For standard systems with 50 stages and a massive condenser. But this has a single stage and the condenser is far smaller because it operates at a higher temperature.

    Per given power output this is vastly lighter.
     
  8. Jul 22, 2019 #8

    Vigilant1

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    This turbine could definitely prove practical in powering an airplane -- with the right 2-stage series hybrid architecture:
    1) Use the CO2 turbine to drive a transmission with many gear sets that eventually powers a drill bit at low RPM/high torque
    2) Use that drill bit to dig a hole in the earth until oil is found. Refine that oil into aircraft fuel appropriate for an airplane.
     
  9. Jul 22, 2019 #9

    pictsidhe

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    A single stage? Do you have a citation for that?
     
  10. Jul 22, 2019 #10

    bmcj

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    I believe the (Cessna) Citation uses two turbines. :p
     
  11. Jul 22, 2019 #11

    Doggzilla

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    The article that you did not read.
     
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  12. Jul 23, 2019 #12

    pictsidhe

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    I did read it. this jumped out: "The turbine features a rotor that is 4.5 feet long, 7 inches in diameter, and only weighs 150 pounds."
    I did not see the number of stages mentioned. A 7" diameter single stage is not going to to be 4 1/2 feet long...
     
  13. Jul 24, 2019 #13

    Doggzilla

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    There is a picture included. Its a single stage with a long shaft attached. They even have a picture of the single stage casing and its like a turbo casing.
     
  14. Jul 24, 2019 #14

    pictsidhe

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    My knowledge of thermodynamics suggests that a single stage would be very unlikely in a ground power plant. The pressure ratio and work ratio will be very low. That's not good for efficiency. A picture of one isolated part isn't good evidence.
     
  15. Jul 24, 2019 #15

    RonL

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    This adds a wee bit of info...

     

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  16. Jul 25, 2019 #16

    Doggzilla

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    As Ive stated, it keeps the pressure high so that the density is more like liquid than gas. It is several times the maximum pressure inside the highest compression aircraft turbine available today. The thickness of the working fluid is the key to such power density.
     
  17. Jul 25, 2019 #17

    Doggzilla

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    That is not the turbine they are talking about, they even show the completed single stage turbine in the video. What he is holding is very clearly a plastic model of an axial turbine.
     
  18. Jul 25, 2019 #18

    RonL

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    Unless they are implying two different machines, the plastic (?) mock-up shows (to me) the power extraction area. This is clearly a very high-speed unit with a fast cycle loop time.
     

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