Periodic Reporting for period 1 - FLEX4H2 (Flexibility for Hydrogen)
Reporting period: 2023-01-01 to 2024-06-30
The EU has committed to achieving climate neutrality by 2050 and reducing greenhouse gas emissions by at least 55% by 2030. To reach these ambitious targets, there is a need for deploying renewable energy sources and improving energy efficiencies. Hydrogen (H2) offers reliability, independence from weather conditions, and potential for decarbonization, but challenges arise with high hydrogen content, such as flashback risk, complying with emission limits, and material challenges. To tackle these challenges, FLEX4H2 aims at moving technological frontiers for low-emission hydrogen combustion in modern gas turbines at high firing temperatures and pressures. FLEX4H2 will design, develop, and validate a highly fuel-flexible sequential combustion system operating with any concentration of hydrogen admixed with natural gas (NG) up to 100% at H-Class operating temperatures, maximizing power and efficiency, while meeting emission targets. FLEX4H2 will tackle the challenges related to H2 combustion by maturing the sequential combustion technology through a combination of design optimisation, analytical research, and validation in a relevant environment. FLEX4H2 will validate scaled and full-size prototypes of the combustor through dedicated atmospheric and high-pressure test campaigns up to TRL6. During the tests, the combustor’s capability of operating at any mixture of hydrogen and natural gas will be demonstrated, without diluents while complying with emission limits. In addition, the possibility to start-up the engine on any amount of H2 in natural gas will be demonstrated.
The design of the first generation of an H2-optimised combustor has been completed successfully. Operation at 100% H2 at full pressure resulted in a stable and reliable flame. The tests highlighted the combustor's ability to seamlessly switch between natural gas and hydrogen, demonstrating its remarkable fuel and operational flexibility, while NOx emissions were minimised. Main limitations were the development of flashback, which restricted the hot gas temperature for the current prototype hardware. Currently, development of the second generation, aiming for a wider flashback margin and higher exit temperature, is underway.
To develop a 2-stage combustor, FLEX4H2 is predicting auto-ignition, flame propagation and flame stabilisation in both combustion stages through advanced numerical modelling (high-resolution Large Eddy Simulations with a sub grid-scale combustion model and well-established chemical kinetics). A platform for burner geometry/data exchange has been established, and the simulations are validated with experimental results. For the 2nd combustion stage, a first validation case has been selected and the rig geometry was transferred, initial testing on commercially-relevant configurations has been carried out. The simulations will also guide the next developmental steps.
Thermoacoustic instabilities are a major challenge for stable and reliable H2 combustion. FLEX4H2 aims to identify these instabilities and develop countermeasures. For a reliable thermoacoustic characterisation, the project is developing algorithms to predict flame dynamics (i.e. Flame Transfer Matrices), which will be validated based on experimental data. The experimental rig geometry for two-stage combustion has been finalized through the network modelling tool and measurements in Full Can Setup have been carried out. Currently, the simulations are being optimised.
To develop a 2-stage combustor, FLEX4H2 is predicting auto-ignition, flame propagation and flame stabilisation in both combustion stages through advanced numerical modelling (high-resolution Large Eddy Simulations with a sub grid-scale combustion model and well-established chemical kinetics). A platform for burner geometry/data exchange has been established, and the simulations are validated with experimental results. For the 2nd combustion stage, a first validation case has been selected and the rig geometry was transferred, initial testing on commercially-relevant configurations has been carried out. The simulations will also guide the next developmental steps.
Thermoacoustic instabilities are a major challenge for stable and reliable H2 combustion. FLEX4H2 aims to identify these instabilities and develop countermeasures. For a reliable thermoacoustic characterisation, the project is developing algorithms to predict flame dynamics (i.e. Flame Transfer Matrices), which will be validated based on experimental data. The experimental rig geometry for two-stage combustion has been finalized through the network modelling tool and measurements in Full Can Setup have been carried out. Currently, the simulations are being optimised.
FLEX4H2 aims to overcome the existing technological challenges in combustion systems towards 100% H2 operation. This will be achieved by the further development and optimisation of Ansaldo Energia’s current sequential combustion system to better control auto-ignition and flame stabilisation for hydrogen volumetric contents up to 100% and broader safety margins for flashback free operation, while minimising NOx emissions, maintaining GT Class operating temperature, and avoiding engine performance loss. FLEX4H2 will advance the understanding of sequential combustion through high pressure experimental data for hydrogen content up to 100% and related numerical modelling. FLEX4H2 will obtain unique experimental dataset on pressurised flames at typical sequential combustor conditions focusing on hydrogen fractions between 70-100% providing an accurate model representation of hydrogen enriched flames at high pressure. FLEX4H2 will demonstrate fuel flexibility at full-scale and engine representative conditions for the full range of hydrogen / natural gas blends to compensate the major changes in fuel properties by accurately tuning the fuel splits, and optimising the nozzle positioning and fuel injection strategy. Additionally, the mixing section design and the combustor residence time will be optimised for low NOx operation with very high H2 contents and the combustor start-up procedure will be tuned to ignite and ramp-up the engine with any amount of H2. FLEX4H2 will pave the way for future R&D activities at higher TRL levels with clear perspective for replication, uptake and operation with the ultimate goal for commercialisation beyond the completion of FLEX4H2. The new combustor technology will have a direct impact on the balancing of the electric power system and, hence, determine the amount and fraction of both intermittent and fluctuating electric energy feeding the grid. The project will push gas turbine fuel and load flexibility beyond state of the art, enabling larger amounts of renewable energy to be exploited. FLEX4H2 will reduce Europe’s dependency on fossil fuels by contributing extensive carbon-free, on-demand response power. Developing a retrofittable system, the project aims at the refurbishment of existing assets, thus offering great opportunities of commercial development and job creation.
A technology roadmap towards commercialisation by 2030 (cf. D5.5) will be developed, assessing positioning until 2030 and the transition beyond. FLEX4H2 will evaluate a wider application of the results to Ansaldo Energia’s product portfolio, inclduing retrofit potentials for existing gas turbines. In this respect, a transfer into the EDISON plants in Porto Marghera or Presenzano could be considered for an integrated demonstration project around 2030. Additionally, the roadmap will support European supply chain actors to develop a portfolio of solutions providing clean, renewable and flexible power generation for all end users’ needs and across all system sizes. Based on the results of FLEX4H2 the impact of Hydrogen combustion on NOx emission levels will be assessed and can be used as a base for a future European emission regulatory and standardization framework.
Further research for a broader application of sequential combustion in smaller engines platforms should be supported to enhance the impact of the FLEX4H2 technology on gas turbine power plants.
A technology roadmap towards commercialisation by 2030 (cf. D5.5) will be developed, assessing positioning until 2030 and the transition beyond. FLEX4H2 will evaluate a wider application of the results to Ansaldo Energia’s product portfolio, inclduing retrofit potentials for existing gas turbines. In this respect, a transfer into the EDISON plants in Porto Marghera or Presenzano could be considered for an integrated demonstration project around 2030. Additionally, the roadmap will support European supply chain actors to develop a portfolio of solutions providing clean, renewable and flexible power generation for all end users’ needs and across all system sizes. Based on the results of FLEX4H2 the impact of Hydrogen combustion on NOx emission levels will be assessed and can be used as a base for a future European emission regulatory and standardization framework.
Further research for a broader application of sequential combustion in smaller engines platforms should be supported to enhance the impact of the FLEX4H2 technology on gas turbine power plants.