Conceptual gas turbine modeling for oxy-fuel power cycles

Lund University / Chalmers University of Technology Klas Jonshagen, started my PhD work at Lund University in Plan on presenting my thesis in December 2010 Hanna Persson will start her PhD work the 1st of June 2010 at Lund University Egill Maron Thorbergsson, started my PhD work at Chalmers University in January Who are we

Lund University / Chalmers University of Technology Cycle analysis of Graz cycle and SCOC Conceptual turbomachinery design Component optimization Full cycle optimization Project objectives

Lund University / Chalmers University of Technology Graz cycle

Lund University / Chalmers University of Technology Collaboration in NEWAC with Graz University –Received IPSEpro model from Wolfgang Sanz (Institute for Thermal Turbomachinery and Machine Dynamics) Graz model Oxygen production and compression, and compression of CO 2 taken into account

Lund University / Chalmers University of Technology Cooling of turbine The Graz cycle uses a simple stage-by-stage cooling model. * The cycle efficiency is dependent on gas turbine cooling flow The Stanton number depends on the conceptual gas turbine design –Blade chord => Re number => Stanton number => Cooling flow => Cycle efficiency * Sanz, W., Jericha, H., Bauer, B., Göttlich, E., 2007, "Qualitative and Quantitative Comparison of Two Promising Oxy-Fuel Power Cycles for CO2 Capture“, ASME Paper GT , ASME Turbo Expo 2007, Montreal, Canada

Lund University / Chalmers University of Technology Cooling of turbine Validity of Graz cooling model was questioned: In particular sensitivity towards design choices was feared (Fixed St number was used in Graz publication) Conceptual design of a large range of turbines resulted in +/-20% variation in Stanton number Impact on cycle efficiency was +/-0.3% It is, at the time of writing, considered that a cooling system predicted by the simple expression can in general be designed

Lund University / Chalmers University of Technology One of the aspect of oxy-fuel cycles is the high pressure Beyond bars gases no longer follow the ideal gas law IPSEpro (heat and mass balance program) limit is 30 bars To be able to calculate cycle at high pressures we are working on implementation of REFPROP to IPSEpro REFPROP is an acronym for REFerence fluid PROPerties, program from NIST. Extend thermodynamic modelling of gases

Lund University / Chalmers University of Technology SCOC H2O CO2 O2 Fuel

Lund University / Chalmers University of Technology SCOC – Turbine design  LUAX-T modified for SCOC/OXUFUEL adaption Power density driven by SOT High SOT results is advanced cooling and 4 th generation materials Radiation issues? High effectiveness levels results in careful optimization of V1 aspect ratio, loading, flow fcn and reaction (Aero 1) – modified m-star model required for cooling assessment. Penultimate cooling feed for rotor #1 – some SAS modeling required.  REFPROP

Lund University / Chalmers University of Technology GTSCOCGRAZ AR 1.3 % (kg/kg) 4.8 % (kg/kg) 0 % (kg/kg) O2O2 11 %~0 % CO %88 %23 % H2OH2O6.4 %6.2 %76 % N2N %1 % Isentropic exp Gas constant Exhaust gas composition

Lund University / Chalmers University of Technology EGT versus firing- and pressure level SCOC EGTGT EGT PR 18,5 COT1500 ºC 825 ºC 640 ºC

Lund University / Chalmers University of Technology A reduced specific gas constant corresponds to an increased density For a specific component a increased density will increase the mass flow Specific Gas Constant

Lund University / Chalmers University of Technology Cooling with CO 2 / steam, radiation High pressure ratios requires real gas calculations How much gas dissolves in H 2 O in the exhaust gas condenser? And so forth… Oxy-fuel cycle Issues

Lund University / Chalmers University of Technology Establish a conceptual design tool for the turbomachinery components of the gas turbine topping cycle Near future work