Session: 30-09 Oxy-Fuel Combustion

Paper Number: 154107

Detailed Design and Cost Estimation of a 300 MWe Oxy-Fuel sCO2 Turbine 

The detailed design of a 300 MWe, utility scale oxy-fuel turbine has been completed as part of a development effort for 21^st century power plant advancement. The oxy-fuel turbine operates in the sCO₂ direct fired Allam-Fetvedt cycle, targeting near-zero emissions and a 43% LHV system efficiency. The turbine with its supporting plant aim to offer a lower cost per unit power produced than a natural gas combined cycle plant employing carbon capture. The oxy-fuel turbine conditions include an inlet temperature of 1150°C and inlet pressure of 305 bar. The density and heat transfer properties of sCO₂ allow for a compact design that can meet these challenging turbine inlet conditions, of temperatures near that of a gas turbine simultaneously with pressures near an ultra-supercritical steam turbine. The combustor housing and turbine designs were completed according to the ASME BPVC; the turbine case specifically incorporates a multi-body design with inner high-pressure barrel case and low-pressure (30 bar) horizontally split outer case. Cooling flow from recuperator outlet streams in the closed-loop cycle are used for housing and case thermal management to enable use of lower cost low-chromium steels. Lateral rotordynamic evaluation demonstrated acceptable vibration response for a range of imbalance conditions per API standards, with the required bearing span informing exhaust diffuser geometry. The cooling flow employed in the six-stage turbine flowpath for the stators and blades to meet a predicted hot-section component lifetime of 30,000 hrs. was determined by thermal and structural modeling of the first stage, incorporating component testing data of common internal cooling technologies at the higher Reynolds number regime exhibited by supercritical CO₂. The provided cost estimate of the turbine is formed through a combination of scaled up-costs from procured 10 MWe scale sCO₂ turbomachinery hardware, and vendor provided budgetary quotes of larger components including the turbine case requiring casting, welding, and final machining processes. The performance and cost estimation of the oxy-fuel turbine predicted for the completed detailed design provides important information towards future development needs for market penetration of utility scale direct fired sCO₂ power cycles further into the 21^st century.

Presenting Author: Michael Marshall Southwest Research Institute

Presenting Author Biography: Mr. Marshall is a senior research engineer at Southwest Research Institute in San Antonio, TX. He earned his Bachelors in Aerospace Engineering from the University of Virginia. His past experience includes experimental heat transfer testing, turbomachine and heat exchanger design, root cause failure analysis, and thermodynamic cycle modeling.

Authors:

Michael Marshall Southwest Research Institute
Mark Anguiano Southwest Research Institute
Jason Bensmiller Southwest Research Institute
Cole Replogle Southwest Research Institute
Thomas Kerr Southwest Research Institute
John Klaerner Southwest Research Institute
J. Jeffrey Moore Southwest Research Institute