Combined Cycle - Features

In single shaft solutions, the power train is designed to house all the main equipment in the same building, with a compact arrangement that optimises operation in terms of accessibility, maintainability and health and safety criteria. To minimize the maintenance schedule, the loading bay is located on one side of the shaft line, with two bridge cranes installed on the same runway.

Both cranes are needed for electrical generator maintenance, but they can also be used separately for gas and steam turbine maintenance. The same approach is used for the multi-shaft 2+1 layout, where the plant arrangement includes two separate power islands, a gas turbine area and a steam turbine area. All electrical and control equipment required for start-up and normal gas turbine operation is installed in three prefabricated and factory tested containers located outside the gas turbine building.

Table 1 Single-shaft Multi shaft 2+1 Gas turbine model V94.3A V94.3A Steam turbine type MT 15 C axial exhaust RT 30 lateral exhaust Generator type H2 THRL 63 Top Air HRSG Reheat triple pressure natural circulation Reheat triple pressure natural circulation Condenser pressure (bar) 0.05 0.05 Net power (MW) 803.6 810.9 Net efficiency (%) 56.8 57.3