Conceptual Gas Turbine Modeling for OxyFuel Power Cycles

Conceptual Gas Turbine Modeling for Oxy-Fuel Power Cycles TURBO POWER Program Conference 14 April 2011 Egill Maron Thorbergsson Department of Applied Mechanics Chalmers

Project objectives • Cycle analysis of Graz cycle and SCOC • Conceptual turbomachinery design • Component optimization • Full cycle optimization Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Introduction • Joint Chalmers University/Lund University project – Project started 18 th Jan. 2010 • Design components for two cycles; the Graz cycle and the semi-closed oxy-fuel combustion combined cycle • Develop design tools to design turbomachinery components in oxy-fuel cycles. Conceptual design work is divided according to: – Chalmers focuses on compressor design – Lund University focuses on turbine design Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

What is an oxy-fuel combustion cycle? • Oxygen is separated from air before combustion – Working fluid is different – Carbon dioxide in semi closed oxy-fuel combustion combined cycle (SCOC-CC) – Water (steam) in the Graz cycle different design principles for the gas turbine Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

What is a conceptual design tool? • One step beyond traditional thermodynamic analysis by estimating the key dimensions of the gas turbine • Thermodynamics, aerodynamics and mechanics constraints Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Conceptual compressor design • In-house tool – Mean line design tool • Handles non-ideal fluids (REFPROP) – Wright & Miller loss correlations • • • Adapted to oxy-fuel gas composition Implemented in MATLAB Calibrated against NASA data (Ideal gases) Transonic compressors Suitable for double circular arc profile Selection of incidence angles and pitch-cord and aspect ratio based on Mc. Kenzie Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

SCOC-CC – Compressor Meanline design Sammak, M. et al. ”CONCEPTUAL DESIGN OF A MID-SIZED, SEMI-CLOSED OXY-FUEL COMBUSTION COMBINED CYCLE” ASME TURBO EXPO 2010 Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Conceptual optimization approach • ISABE conference in Göteborg september 2011. – Multicriteria optimization of conceptual compressor aerodynamic design Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Master Thesis • Multidisciplinary conceptual design of a transonic high pressure compressor – Funda Ersavas – Started in November and will finish in June (60 credits) Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Project objectives • Cycle analysis of Graz cycle and SCOC • Conceptual turbomachinery design • Component optimization • Full cycle optimization Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

SCOC-CC Semi-Closed Oxy-fuel Combustion Combined Cycle TURBO POWER Program Conference, Gothenburg 14 April 2011 Majed Sammak Lund University Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Topics • • Introduction Calculations Results Papers Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Introduction • Purpose – Combined cycle – CO 2 capture system • Description • Requirements – Competes with other CO 2 capture systems • Post combustion – Chilled Ammonia – Advanced Ammine • Pre combustion • Oxy fuel combustion Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Introduction • Requirements – CO 2 capture efficiency – Impact on environments – Energy consumption • ASU • CO 2 compression • Integration – Availability • Integration • Components design Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Calculations 1. Changing the working fluid from Air to CO 2 Thermodynamic properties Units Air Carbon dioxide Cp k. J/kg C 1. 005 0. 846 Cv k. J/kg C 0. 718 0. 657 R k. J/kg C 0. 287 0. 189 γ - 1. 4 1. 289 ρ kg/m 3 1. 2 1. 84 M kg/kmol 28. 9 44. 01 2. Heavier gas, Lower speed of sound Impact both in the cycle design and gas turbine design Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Calculations 1. Cycle simulation: IPSEpro+REFPROP – Impact on cycle • Oxy combustion • COT around 1400 o. C • Gas turbine cooling from the compressor 30% from turbine inlet flow – Work done • Mid-sized, semi-closed dual-pressure oxy-fuel combustion combined cycle 136 MW ( Gross power), 108 MW (Net power). • Gas turbine cooling • Optimization Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Calculations Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Calculations Single shaft + Simple - Bigger compressor - Lower rotations speed Twin shaft - Complex + Higher rotations speed + Less stages Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Calculations • Single shaft (Turbine design) – Lower Speed of sound Higher Mach number – Mach number limitations to 0. 6 Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Results SCOC-CC Compressor mass flow kg/s 190 - 39 o. C 1400 Gas turbine power, Turbine MW 156 Gas turbine power, Compressor MW Compressor pressure ratio Combustor outlet temp. Gas turbine power MW 67 87 Total heat input MW 230 Steam turbine power MW 49 Gross power output MW 136 % 59 O 2 generation + Compression MW 23 CO 2 compression to 200 bar MW 5 Net power output MW 108 % 47 Gross efficiency Net efficiency Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Results • Turbine design – – N=5200 rpm U=380 m/s AN 2= 40 106 4 stages Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Papers Work Done: • ASME paper: Conceptual Design of A mid-sized Semi. Closed Oxy-Fuel Combustion Combined Cycle , Draft. GT 2011 -46299 • Accepted • Master thesis: ”Parametric Blade Profiling Methods and Improvements on LUAX-T With Emphasis on Oxy-Fuel Cycles”, Jonas Svensson – Rapid 11 parameter blade profiling with start-value recommendations – Radiation from three-atomic gas Chalmers – Egill Thorbergsson / Lund University – Majed Sammak

Parametric blade profiling Chalmers – Egill Thorbergsson / Lund University – Majed Sammak