Supercritical carbon dioxide Brayton Cycle turbines promise giant leap

[OKIsItJustMe]

http://www.eurekalert.org/pub_releases/2011-03/dnl-scd030311.php

Public release date: 4-Mar-2011

Contact: Neal Singer
[e-mail]
505-845-7078
http://www.sandia.gov/">DOE/Sandia National Laboratories

Supercritical carbon dioxide Brayton Cycle turbines promise giant leap

ALBUQUERQUE, N.M. — Sandia National Laboratories researchers are moving into the demonstration phase of a novel gas turbine system for power generation, with the promise that thermal-to-electric conversion efficiency will be increased to as much as 50 percent — an improvement of 50 percent for nuclear power stations equipped with steam turbines, or a 40 percent improvement for simple gas turbines. The system is also very compact, meaning that capital costs would be relatively low.

Research focuses on supercritical carbon dioxide (S-CO₂) Brayton-cycle turbines, which typically would be used for bulk thermal and nuclear generation of electricity, including next-generation power reactors. The goal is eventually to replace steam-driven Rankine cycle turbines, which have lower efficiency, are corrosive at high temperature and occupy 30 times as much space because of the need for very large turbines and condensers to dispose of excess steam. The Brayton cycle could yield 20 megawatts of electricity from a package with a volume as small as four cubic meters.

The Brayton cycle, named after George Brayton, originally functioned by heating air in a confined space and then releasing it in a particular direction. The same principle is used to power jet engines today.

"This machine is basically a jet engine running on a hot liquid," said principal investigator Steve Wright of Sandia's Advanced Nuclear Concepts group. "There is a tremendous amount of industrial and scientific interest in supercritical CO₂ systems for power generation using all potential heat sources including solar, geothermal, fossil fuel, biofuel and nuclear."

Sandia currently has two supercritical CO₂ test loops. (The term "loop" derives from the shape taken by the working fluid as it completes each circuit.) A power production loop is located at the Arvada, Colo., site of contractor Barber Nichols Inc., where it has been running and producing approximately 240 kilowatts of electricity during the developmental phase that began in March 2010. It is now being upgraded and is expected to be shipped to Sandia this summer.

…

A competing system, also at Sandia and using Brayton cycles with helium as the working fluid, is designed to operate at about 925 degrees C and is expected to produce electrical power at 43 percent to 46 percent efficiency. By contrast, the supercritical CO₂ Brayton cycle provides the same efficiency as helium Brayton systems but at a considerably lower temperature (250-300 C). The S-CO₂ equipment is also more compact than that of the helium cycle, which in turn is more compact than the conventional steam cycle.

…

[phantom power]

1. 20 megawatts in 4 cubic meters...

wow

[eppur_se_muova]

2. K&R -- too "tech" for popular consumption, but potentially very important. nt

[txlibdem]

5. Should just mention "it's better" and be done with it

:hi:
I know what you mean about a (too large) segment of the populace being scientifically illiterate and/or uncaring of science (as if it doesn't affect their very lives day in and day out).

[Gregorian]

3. Rankine cycle brings back memories. I'm posting both thermodynamic cycles to look at.

Edit- Now that I've studied these again, I read the article. And it's quite interesting how it's essentially a turbine engine running a fluid instead of a gas. Otherwise, there's nothing new here. I look forward to seeing this. Although it's still just polishing a turd, as my dad used to say. Carbon footprint city.


I just want to see these side by side.

Rankine-


Brayton- key words here are adiabatic and isobaric.

[txlibdem]

4. Would this be good for geothermal, solar thermal, and nuclear power plants?

I think it would be usable across the board for green power generation.

Way to go!

[OKIsItJustMe]

6. From the release…

"There is a tremendous amount of industrial and scientific interest in supercritical CO₂ systems for power generation using all potential heat sources including solar, geothermal, fossil fuel, biofuel and nuclear."

[txlibdem]

7. Thanks

My reading skills must be slipping.

:hide: