FlameSheet is Hanwha Power’s advanced combustion system for operators seeking lower emissions, greater fuel flexibility, and extended inspection intervals from their gas turbines. Designed as a drop-in retrofit for GE, Siemens-Westinghouse, and MHI engines, including 7F, 501F, 7EA, 6B,Frame 5, and OP16, FlameSheet is commercially proven with 33 units operating or under contract worldwide. Four units are actively burning hydrogen fuel blends, including a Frame 7E installation that achieved the industry’s first 60% hydrogen by volume at base load with single-digit NOx and CO emissions.
FlameSheet Technical Specifications
Specification
Value
NOx Emissions
Single-digit ppm on natural gas; sub-5 ppm achievable
CO Emissions
Single-digit ppm across premix operating range
Hydrogen Capability
Up to 60% H2 by volume demonstrated at baseload (industry record); 80% H2 demonstrated in high-pressure rig testing; HyFlex version supports variable H2/NG blends
Alternative Fuels
Ethane (up to 40%), propane (up to 20%), butanes (up to 10%), LNG, shale gas, refinery off-gas
Operating Range
Up to 30% wider than OEM standard combustion; 30% Modified Wobbe Index (MWI) range
Turndown
25-30% of baseload for 7F; 35-40% for 501F (with AutoTune + inlet bleed heat). Additional 5-10% with exhaust bleed system
Inspection Interval
32,000 factored hours or 1,250 factored starts
Compatible Frames
GE 7F, 7EA, 6B, Frame 5; Siemens/Westinghouse 501F; MHI; OPRA OP16
Installation
Drop-in retrofit; modular installation during standard combustion inspection outage; compatible with existing turbine controllers and fuel skids
Installed Base
36 units operating and under contract (through 2027); 4 units actively burning hydrogen
Flashback Protection
Active flashback monitor with fast runback; restores emissions compliance within 40 seconds
How FlameSheet Works
FlameSheet uses an aerodynamic trapped vortex mechanism tostabilize combustion across a wide range of fuel compositions and operatingconditions. The flame is anchored at a geometric vortex point rather than beingdependent on fuel properties, which is what enables FlameSheet to burn fuelsranging from natural gas to 60%+ hydrogen blends without hardware changes. Thesystem uses four fuel circuits (pilot, pilot tune, main 1, and main 2) that areindependently controlled by Hanwha Power’s AutoTune system. This multi-circuitarchitecture allows precise fuel/air ratio management across the entireoperating range, from baseload to deep turndown. FlameSheet Gen VI incorporatesmicro-mixer technology in the pilot circuit, reducing flame length andimproving fuel/air uniformity. This design specifically addresses thechallenges of highly reactive fuels like hydrogen, where conventional premixcombustors face stability and flashback limitations. An active flashbackmonitoring system with fast runback capability protects combustor hardware. Ifa fuel quality event occurs, the system cuts fuel to the affected circuit andrestores emissions compliance within 40 seconds.
Durability and maintenance Features
FlameSheet is engineered to lower lifecycle costs and extend plant asset value:
- Designed to reduce cycling fatigue with broad turndown capability
- Minimizes wear with fewer hot combustion components
- Streamlines outage scope with modular installation
- Enhances operational flexibility across a wide fuel spectrum
- Includes optional HRSG protection settings for low-load scenarios
- AutoTune integration included with every FlameSheet installation for automated combustion tuning and emissions optimization
FlameSheet and Alternative Fuels: Proven Performance
FlameSheet is one of the few commercially proven combustion systems capable of burning high hydrogen fuel blends in existing heavy-duty gas turbines, without water, steam, or nitrogen injection. In July 2023, Hanwha Power achieved an industry record: a Frame7E gas turbine operating at baseload with 60% hydrogen by volume, achieving single-digit NOx and CO emissions. The installation at the Hanwha/Total Energies site in Daesan, South Korea, demonstrated that existing gas turbines equipped with FlameSheet can deliver deep decarbonization while maintaining emissions compliance and dispatch reliability. High-pressure rig testing has demonstrated FlameSheet performance at up to 80% hydrogen. Hanwha Power’s development roadmap targets 0 to 100% hydrogen capability, positioning FlameSheet-equipped gas turbines as fully future-proofed assets in the energy transition. Hanwha Power has also demonstrated hydrogen co-firing with the LEC III combustion system, successfully operating three Frame 9E turbines in the Netherlands with up to 25% hydrogen since 2018.
Want to learn more about upgrade options?
FlameSheet FAQs
FlameSheet is compatible with GE 7F (7F.03, 7F.04, 7F.05),GE 7EA, GE 6B, GE Frame 5, Siemens/Westinghouse 501F, and MHI platforms.FlameSheet has also been tested on the OPRA OP16 engine. It is designed as adrop-in retrofit that works with existing turbine controllers and fuel skids.
Yes. FlameSheet has demonstrated up to 60% hydrogen byvolume at baseload with single-digit NOx and CO emissions, an industry recordachieved on a Frame 7E gas turbine at a Hanwha/TotalEnergies site in Daesan,South Korea. High-pressure rig testing has demonstrated up to 80% hydrogen. TheHyFlex version of FlameSheet supports variable hydrogen/natural gas blends. HanwhaPower’s development roadmap targets 0 to 100% hydrogen capability.
As of 2026, 33 FlameSheet units are operating or under contractworldwide, including 4 units actively burning hydrogen fuel blends.Installations span GE 7F, 501F, 7EA, and other B-, E-, and F-class platformsacross multiple countries.
FlameSheet is rated for 32,000 factored hours or 1,250factored starts between inspections. This represents a significant extensionbeyond OEM standard combustion system intervals, reducing total lifecyclemaintenance costs.
When paired with Hanwha Power’s AutoTune and inlet bleedheat, FlameSheet achieves turndown to 25-30% of baseload on the 7F and 35-40%on the 501F, compared to 65-70% with OEM standard combustion systems. Adding HanwhaPower’s exhaust bleed system extends turndown an additional 5-10%. This enablesflexible dispatch in markets with high renewable penetration.
FlameSheet supports a wide range of fuels including naturalgas, LNG, shale gas, ethane (up to 40%), propane (up to 20%), butanes (up to10%), refinery off-gas, and hydrogen blends. It operates within a 30% ModifiedWobbe Index (MWI) range, accommodating significant fuel composition variabilitywithout hardware changes.
Related Technologies and Services
Complementary Technologies:
AutoTune: Automated Combustion Tuning
GTOP: Gas Turbine Optimization Package
