This article is part of our series on “Transition 2 Hydrogen”, covering suppliers whose technologies and solutions will contribute to the switch to burning 100% hydrogen in gas turbines, and to the rollout of hydrogen solutions in power generation, energy storage, electrolyzer technology, and pipeline/distribution. To register for monthly updates, CLICK HERE
Ansaldo Hydrogen Gas Turbine Technology
Ansaldo Energia offers the following hydrogen capabilities for its gas turbine engine portfolio:
• Up to 50% vol. Hydrogen blend natural gas for the GT36 H-class engine,
• Up to 30% or up to 45% vol. Hydrogen blend in natural gas depending on the particular GT26 F-class engine rating, and
• Up to 25% vol. Hydrogen blend in in natural gas for the AE94.3A F-class engine.
The AE94.3A F-class engine acquired broad commercial operating experience with two units accumulating 245,000 Equivalent Operating Hours on various hydrogen and natural gas blends up to 25% vol. Hydrogen.
The advantage of the Ansaldo GT26 F-class engine with reheat technology is an additional degree of freedom balancing the power of the two combustion chambers. A variation of flame temperature of the first burner is an effective parameter to maintain low Nox emissions and offsetting the impact of fuel reactivity on the auto-ignition delay time of the downstream reheat burner.
Extensive single burner high pressure tests at full scale were performed for existing Ansaldo GT26 standard premix and reheat burners with 15 to 60% vol. H. in natural gas. This confirmed that the latest rating (2011) can cope with contents of up to 30% vol. Hydrogen with no changes in hardware and without performance penalty. With further validation and minimal de-rating, this limit can be extended to 45% vol. Hydrogen.
This additional freedom is exploited to an even larger extent in the Ansaldo Energia GT36. Since this can-annular engine does not have a high pressure turbine separating the two combustors, the system is called Constant Pressure Sequential Combustion (CPSC) design.
Thanks to this, no efficiency or power penalty is incurred when lowering the temperature between the two combustion stages. The GT36 is available for commercial operation with hydrogen contents of up to 50% vol. Further validation is ongoing, including full scale, high pressure tests.
With the hardware as is, operation on up to 70% vol. H2 was demonstrated with minimal or no de-rating and without dilution or selective catalytic reduction (SCR). With further optimization this H2 level is expected to be further extended. In principle, since the CPSC system is a can-combustor design, retrofits to other can-type engines are possible.
Recently, Ansaldo Energia and Norway’s Equinor announced a collaboration regarding development of a 100% Hydrogen gas turbine combustor. With this, Ansaldo Energia predicts that by 2030 its entire portfolio of gas turbines will be 100% hydrogen capable.