Supercritical Turbine

Sounds very interresting. So If i understand it right Co² is the "fuel" which drives the turbine? Couldnt one just hook it up to a diesel engine and let it generate tons of energy ?
 
kqcke for you said:
Point taken but you still could right? Let an diesel engine work and use the exhaust as working Fluid.? Or well any combustion engine that produce (clean) Co². It could be very interresting for ships.
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The idea is that you heat the CO2 with a specified fuel, this could be gas, wood pellet, concentrated solar or nuclear etc., the benefit is that you no longer waste energy due to the heat of evaporation, which is present for non-supercritical working fluids. This means that the overall efficiency of the power generation is improved substatially. Steam turbines generally provide 44-48% overall efficiency, so this could boost efficiency to over 50%.

1635yankee said:
Is it related to this project?
www.powermag.com

Supercritical CO2 Pilot Power Plant Gearing Up for 2021 Demonstration

Construction of the 10-MW Supercritical Transformational Electric Power (STEP) pilot plant in San Antonio, Texas, is inching along, and developers in July announced that the building to house the innovative
www.powermag.com www.powermag.com
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Both 10MW, so quite possibly.
 
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Forest Green said:
The idea is that you heat the CO2 with a specified fuel, this could be gas, wood pellet, concentrated solar or nuclear etc., the benefit is that you no longer waste energy due to the heat of evaporation, which is present for non-supercritical working fluids. This means that the overall efficiency of the power generation is improved substatially. Steam turbines generally provide 44-48% overall efficiency, so this could boost efficiency to over 50%.
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Okay thanks so i did understand something wrong. But couldnt one use something like an gas turbine to heat it Up? With the right combination one could get some pretty huge Energy out of it which is perfect for ships. I think that was called combined powerplants or so.
 
I wonder why it is called supercritical turbine and not CO2 cycle XY, given that all modern steam turbine/boilers in coal/gas power plants allready run with supercritical steam. Its different for nuclear power plants due to the much lower steam temperatures, but here, the constant heat adsorbtion by evaporation is not a bug but a feature!

Supercritical steam cycles are not only more efficient, but they avoid any problems with to phases mixtures of gas and liquid.
 
Did anybody come across description of how the system operates with some hard numbers?
Everything I found is full of hype but lacking details. And they like to mix metaphors, comparing to gas turbines or steam turbines, based on which makes their system look better.
 
My idea is, it works more or less like a conventional supercritical steam cycle in which H20 is replaced by CO2. Despite that, there are some more unusual ideas which (quite like suggested from @kqcke for you ) use in fact the the CO2 from exhaust gases from a pure oxygen combustion. Such systems are proposed for CO2 capture and storage coal burning power plants.
 
kqcke for you said:
Okay thanks so i did understand something wrong. But couldnt one use something like an gas turbine to heat it Up? With the right combination one could get some pretty huge Energy out of it which is perfect for ships. I think that was called combined powerplants or so.
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One could use any source of heat: gas turbine exhaust, fossil fuels, nuclear, solar, biomass, geothermal.

Combined cycle plants are fairly common, and have nameplate efficiencies pushing (or exceeding) 50%. Frequently, they use gas turbine exhaust to heat water. A combined cycle plant was proposed as an improvement for the USN's Burke class destroyers but was canceled due to worries about reliability and maintainability.

This supercritical CO2 cycle may be a great bottoming cycle, as it may be able to use a fairly low temperature heat source. Supercritical CO2 is much easier than supercritical H2O, which is fairly common for modern utility plants, as the pressure can be lower that with water.

As an aside, binary cycles (where this CO2 turbine may be used) are fairly old technology, e.g., HELCO's South Meadow station (mercury Rankine cycle topping a conventional steam cycle) which was commissioned in 1929 and decommissioned sometime in the 1960s.

There have been a number of alternatives to water proposed as working fluids for Rankine cycles, including ammonia, mercury, potassium, cesium, organics, e.g., Freon, and sulfur. There have also been cycles built around mixtures, such as the Kalina cycle, and various absorption cycles. Overall, I think I'd much rather have a CO2 turbine running in my neighborhood than one using ammonia, sulfur, or (God help us), mercury.
 
1635yankee said:
This supercritical CO2 cycle may be a great bottoming cycle, as it may be able to use a fairly low temperature heat source.
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Quite the opposite. This system will have similar parameters to gas turbines. Because it is compressing a compressible fluid (CO2), compressor will absorb about half the power produced by the turbine. To get proposed efficiency, it will need to run well above 1000 C.
 
I dont think so, very likely it will be a high pressure cycle were it will condense, note there are even some CO2 compressors for air conditioning of cars which can do that (the pressure is of course much higher compared to conventionel cooling fluids).
 
kqcke for you said:
Okay thanks so i did understand something wrong. But couldnt one use something like an gas turbine to heat it Up? With the right combination one could get some pretty huge Energy out of it which is perfect for ships. I think that was called combined powerplants or so.
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An aircraft gas turbine works on air, the combustor heats up the air by burning fuel. A power station steam turbine works with steam, a boiler using a given fuel (e.g. coal, wood pellets etc.) heats the steam. A supercritical CO2 turbine works with supercritical CO2, you could use any fuel or heat source to heat up the CO2 in the combustor/boiler.
 

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