NO(x) REDUCTION STRATEGY IN GE10 HYDROGEN - FUELLED HEAVY DUTY GAS TURBINE

In December 2006 Enel promoted a project oriented towards Environment and Innovation including the development of zero emission plants. The hydrogen project foresees the construction of a I I MW,, hydrogen-fed gas turbine able to couple high efficiency (fuel utilization) with low nitrogen-oxide emissions. The project (partly funded by Regione Veneto, a local authority in the North-East of Italy), will be built at Enel's coal-fired Fusina Power Plant [1]. The aim of a first demonstrative phase is to verify the correct operation of the gas turbine supplied by pure hydrogen and to acquire know-how of hydrogen combustion, safety aspects and control technologies in gas turbine cycles. In the second phase, the goal will be to optimize the combustion technology, paying particular attention to NO(x) emissions. To make hydrogen suitable for the electricity generation in an environmentally compatible manner, Enel is developing the Fusina's experimental power plant project. Since currently no commercial hydrogen burners are suitable for gas turbine power plants, both Enel and Nuovo Pignone are investigating feasible solutions for a hydrogen-fuelled low-NO(x) diffusion burner design. In this context, this paper presents the results from a CFD analysis showing the NO(x) reduction based on steam injection and burner minor modifications. An initial model with a coarse mesh and simple aerodynamic treatment was used to evaluate the NO(x) emissions with varying amount of steam injected into the combustion chamber. In the view of the following experimental campaign, some solutions have been selected after an initial tuning of the CFD model. Furthermore, a second CFD model based on a finer mesh and a detailed geometry discretization will enable a more precise investigation of the fluidynamic field. Results of the numerical model, which simulates a GE10 gas turbine combustor fuelled with pure hydrogen, are presented and compared with experimental tests at full scale and full pressure conditions.