PDF Publication Title:
Text from PDF Page: 018
TA 4.R: Supercritical Carbon Dioxide Brayton Cycle sCO2 is nearly twice as dense as supercritical steam and moves 11 times faster (in terms of mass flow rate) than supercritical steam in their respective systems. Thus, the compact size of the turbomachinery in the sCO2 cycles results in a flow of a high density fluid at very high velocities. Owing to turbine speeds remaining constant, the issue of erosion is expected to be encountered in scale-up. In addition, inspection of the printed circuit heat exchanger within the closed Brayton Cycle system found an agglomeration of hydrocarbons and erosion products at the inlet. To address the erosion issues in gas and steam turbines, a wide variety of coating systems have been explored by industry and various erosion-resistant coatings are in commercial use today. The selection of an appropriate coating system depends on the underlying substrate metal as well as (perhaps more importantly) on the source and properties of the particulate causing the erosion. For example, Bettis employs a procedure that filters the CO2 five times before use. Creep and Fatigue: Creep, the tendency of a solid material to deform slowly and permanently as a result of mechanical stresses below its yield strength at elevated temperatures, and fatigue, a failure mechanism that occurs when the component experiences cyclic stresses or strains that produce permanent damage, are primary potential limitations that must be accommodated in the design of sCO2 systems. R&D to better understand creep and fatigue associated with sCO2 turbomachinery and heat exchange components is necessary. In the turbomachinery, the gaps between the turbine and compressor wheels and their housings are small, the tip speeds are large, and the temperature (in the turbine) is high. Thus, creep and fatigue become lifetime issues. In the compact heat exchangers used as recuperators or primary heaters in the sCO2 cycles, the pressure difference between the hot and cold legs is large (up to about 25 MPa), and the design goal is to minimize the wall thickness between them to maximize heat transfer and minimize cost while keeping flow passages small and numerous. If the system design constraints drive designs to more-corrosion resistant materials (e.g., due to CO2 interactions), there may be a need to obtain creep rate data for those materials if sufficient data are not available from the manufacturer. Furthermore, diffusion bonding or brazing is used to join the layers of sheets to construct these compact heat exchangers. The diffusion bonded regions (usually less than 50μm thick) of the sheet material may have different chemical composition and microstructure compared to the rest of the sheet material resulting in different mechanical properties. Creep and fatigue behavior of joints (diffusion bonded or brazed) may need to be investigated as a part of the design methodology of compact heat exchangers. In addition to creep and fatigue as purely mechanical considerations as discussed, above the effect of the environment on these mechanical properties may need to be evaluated. For example, how carburization and oxidation of alloys in sCO2 affect the creep rate and fatigue crack growth rate should be investigated. Also, for wall thicknesses below 0.5mm it should be recognized that creep behavior can be significantly different than for bulk material and relatively little information is available on some classes of material in thin sections, particularly the precipitation strengthened Ni-base alloys. Considerable expertise in evaluating creep properties of thin-walled steels and conventional Ni-base alloys for gas turbine recuperators (i.e. heat exchangers) was developed during the development of the Mercury 50 turbine and that information and expertise would be useful for the development of sCO2 recuperators. Valves Any closed Brayton Cycle will require three valve functions: isolation, modulating/throttling, and pressure relief. The isolation and throttling valves are highly engineered and are, therefore, the highest cost valves. Operating mechanisms for these systems exist, but the valve body, internal components, and seat will be immersed in hot sCO2 and subject to materials effects that create uncertainty regarding the design of the valves, requiring R&D. The valve actuator seals will require R&D to demonstrate that they can survive the hot sCO2 environment. 17 QuadrennialTechnologyReview2015PDF Image | Advancing Clean Electric Power Technologies
PDF Search Title:
Advancing Clean Electric Power TechnologiesOriginal File Name Searched:
QTR2015-4R-Supercritical-Carbon-Dioxide-Brayton Cycle.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |