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Combustion and Carbon Cycle 2.0 Robert K. Cheng Combustion Technologies Group Environmental Energy Tech. Div Feb 3, 2010. Combustion Provides > 83% of Our Energy. Burning fossil fuels will be a major energy source for the foreseeable future Near term carbon reduction by fuel switching
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Combustion and Carbon Cycle 2.0 Robert K. ChengCombustion Technologies Group Environmental Energy Tech. Div Feb 3, 2010
Combustion Provides > 83% of Our Energy Burning fossil fuels will be a major energy source for the foreseeable future Near term carbon reduction by fuel switching efficiency enhancement of combustion systems Long term carbon reduction from combustion by renewable fuel sources advanced combustion for renewable fuels carbon capture and storage 2008 U.S. Energy consumption
Combustion Technologies Vary by Energy Sector Land & Sea Transport –Reciprocating engines60 kW – 7 MW Metrics – fuel efficient,durable, low emissions Aviation – Jet engines 5 - 22 MW Metrics – highly reliable, high power density, fuel efficient Electricity Generation Gas turbines & Coal Boilers 100-400 MW Metrics – long duty cycle (20,000+ hrs), highly reliable, fuel-flexible, ultra-low emissions Residential –Gas burners 10 – 100 kWMetrics – safe, durable,ultra-low emissions Commercial & Industrial – gas & oil burners 1 – 30 MWMetric – high efficiency, ultra-low emissionslong duty cycle (24/7 operation)
Wide Spectrum of Combustion Science & Engineering Topics • Combustion is humankind’s oldest technology – reducing emissions and increasing efficiency present many challenges • Combustion integrates multi-scale dynamic interactions between chemistry, thermodynamics, and fluid mechanics • Combustion R&D targets specific needs of each energy sector Combustion mode: Premixed, Non-premixed, Partially premixed Chemistry:Fuel Type: solid, liquid, gasOxidizer: air, O2, diluents Fluid mechanics :steady flows, transient flows,velocity, turbulence, & shear Thermodynamics : Phase change, heat releaseInflow temperature and pressure
Near Term – Carbon Reduction by Fuel Switching • Burning gaseous fossil fuel is cleanest and most efficient • Replacing coal with natural gas for electricity generation • Producing syngases from coal gasification • Vaporizing liquid fuels • Fueling land vehicles with gaseous fuels • Reciprocating engines or fuel-cells • Charging electric land vehicles with electricity generated from natural gas and syngases • Technology challenges • Developing fuel-flexible combustion systems • Meeting stringent emissions standards for stationary combustion systems • Fuel distribution and storage
Near term – Increasing Efficiency to Reduce Carbon • Increased firing pressure & temperature and reduce system losses • Gas turbines • Ultra-low emissions combustion concepts • Advance materials for higher temperature combustion • Waste heat recovery • Technology integration: gas/steam turbines, gas turbines/fuel cells, gas turbine/steam boilers • Advanced reciprocating engines • Direct injection, homogeneous charge compression ignition & active controls • Challenges • Optimize emissions/efficiency trade-off
Combustion Research at LBNL • Chemistry • Combustion chemistry at the molecular scale (CSD and EETD) • Detailed chemical measurements of low pressure flames using soft X-ray probes (ALS) • Chemical mechanisms for flame modeling (EETD) • Premixed Turbulent Flames • Numerical simulations (CRD) • Fundamental studies of flame/turbulence interactions and technology transfer (EETD)
Bridging Science-Technology Gap • LBNL’s low-swirl burner evolved from laboratory tool to clean combustion technology • Developed for basic studies of flame/turbulence interactions • supports stable ultra-low NOx lean premixed flames • Scientific underpinnings facilitate adaptation to 5 kW to 200 MW systems • residential furnaces & water heaters • commercial & industrial heaters • gas turbines operating on natural gas, digester gas, syngases & H2 • Petroleum refining process heaters • Enabling technology for next-generation advanced combustion systems Low-swirl injector for Taurus 70 gas turbine
Low-Swirl Burner Exploits Self-Propelling Natureof Turbulent Premixed Flame Quartzcombustor LSB swirler
Technology Transfer Provides Useful Feedback toPrioritize Basic Research • Natl. Labs./University/Industry collaboration to develop low-swirl burner for high-hydrogen fuel gas turbines in clean coal power plants • Turbulent flame studies at gas turbine conditions • Chemical kinetics of H2 and syngases • Heat release models for H2 and syngas • Laminar and turbulent flames • Turbulence effects on NOx • High fidelity computational tools for engineering design • Challenges • High-hydrogen fuel systems operate in combustion regimes outside of traditional engineering design practices Simulations (top) gives a window into combustion processes that cannot be measured by experiments (bottom)
Carbon Cycle 2.0Combustion Science & Technology Loop chemical kinetics and transport Feedback Transfer * Exclude direct coal-fired systems
Long Term – Examples of Combustion Technology Needs • Reciprocating and jet engines for bio-fuels • Combustion properties of biofuels dictate their suitability for advanced concepts (e.g. HCCI engines) • Near-zero emissions coal power plants • gasification and separation technologies • ultra-low emission fuel-flexible gas turbines • carbon capture and storage technologies • Fuel-cell/gas-turbines hybrid systems • Opportunities for LBNL • New simulation capabilities offer game-changing possibilities for designing new combustion systems • Combustion chemistry of bio-fuels and renewable fuels • Advance materials and electro-chemistry