GE upgrades 9E gas turbine at Italian CHP plant

GE applied its Axial Fuel Staging (AFS) technology upgrade on its 9E gas turbine at Raffineria di Milazzo (RaM)’s Termica Milazzo combined heat and power plant (CHP) in Milazzo, Italy. The modernization was part of a broader project to extend the plant’s operational flexibility, achieve major integration, and decrease total emissions at turndown.

Until this project, RaM and Termica Milazzo plant, located approximately 500 meters from the refinery, were totally separated from both an electrical and automation standpoint. Now, all electrical energy consumption of the Italian refinery (770 GWh in 2018) is supplied by the 9E gas turbine.

The lower load allows Termica Milazzo to respond faster to bidding opportunities in a region that experiences frequent shifts in grid demand due to renewable power fluctuations.  It is now possible to modulate net exported energy production (of the whole complex Refinery and Termica Milazzo) in an extended range—between and potentially to participate in the Italian Balancing Services & Capacity Market.

By performing the AFS upgrade, GE’s gas turbine on-site now has alone a turndown of less than 40% ISO nominal power, corresponding to a target of about 50-55% of the entire thermal combined-cycle performance, compared to the previous 80% turndown level. In addition by derating exhaust masslow at turndown, AFS also improves the gas turbine’s part load efficiency, thus improving the emissions sustainability of the plant and leading to an estimated savings of about 20%, in carbon dioxide emissions (CO2) and similarly in monoxide (CO) and nitrous oxide (NOx) on total amount for year.

The modernization of GE’s gas turbine was part of a broader project, including electrical and automation integration led by TERNA for Electrical Interconnecting work, while ABB supplied the plant Distributed Control System (DCS) and integrated it with the Substation Control System (SCS). The duration of the project since its preliminary phase was about three years. The main gas turbine modifications have been assembled and installed during a gas turbine major overhaul by Fieldcore. The project has spanned almost a year, including the first start-up, operational commissioning and tuning, and test validations.

Axial Fuel Staging has been deployed on the 7HA.01, 7HA.02, 7EA, 7F, 9E and 9HA.02. These fleets have compiled over 415,000 fired hours and 6,000 fired starts.