- Unitary power: 254 MW.
- Speed: 3.000 r.p.m.
- Compression ratio: 15,4:1
- Output gas flow: 640 kg/s.
- Combustion temperature: 1.300 °C.
- Temperature of gases: 609 °C.
MS 9001 FA gas turbines, designed and built by General Electric, are installed. The electrical generator is connected to the gas turbine by a rigid coupling and is located at the end of the turbine compressor. The gas turbine compressor comprises 18 stages fitted with variable geometry stator vanes for optimal performance at partial loads. Low NOx turbine burners have been installed. The gas turbine is a three-stage model. The turbine-compressor is housed in a horizontally sectioned type casing in order to make inspections and maintenance quicker and easier. The turbine-generator set is started up by the generator acting as a motor (LCI). The gas turbine runs on natural gas only (although it is equipped to burn diesel oil as well) and the exhaust gases pass through the heat recovery steam generators which convert them into energy.
Heat recovery steam generator
- HP vapour pressure: 127 barg.(*)
- HP vapour temperature: 567 °C.
- Hot reheating pressure: 26 barg.(*)
- Hot reheating temperature: 568 °C
- LP vapour pressure: 4 barg.(*)
- LP vapour temperature: 274 °C.
(*) Relative pressure.
The plant boasts two natural-circulation heat recovery steam generators, designed and manufactured by BWE. The boilers are housed in the same building and feature three pressure levels and a heater chamber.
The boilers follow ASME design criteria and meet the start-up, shutdown and load-change requirements for gas turbines.
The boiler unit comprises the following sections:
- A high-pressure secondary superheater.
- Secondary and primary heater chamber.
- Steam turbine: 281.823 kW.
- High-pressure evaporator unit.
- High-pressure, high-temperature economizer.
- Intermediate-pressure superheater.
- Intermediate-pressure evaporator unit.
- High-pressure, low-temperature economizer.
- Intermediate-pressure economizer.
- Low-pressure superheater.
- Low-pressure evaporator unit.
- Water supply economizer.
The boiler drums and level-monitoring system have been designed to ensure a suitable operating level without excessive venting flows.
- Unitary power: 281 MW
- Speed: 3.000 r.p.m.
- HP vapour flow: 540 t/h.
- Hot reheating flow: 640 t.
- LP vapour flow (total): 670 t/h.
The condensing steam turbine enables reheating and comprises three stages: high, intermediate and low pressure. All the turbine models have been selected for their specific steam conditions and volumetric flow rates and are fitted with the necessary shutdown and control valves for the high, intermediate and low phases.
The steam originating from the two boilers feeds into a single pipe and is led to the corresponding turbine stage (HP, IP, LP).
The low-pressure stage exhaust is positioned lower down and the steam produced is routed to a condenser located underneath the turbine.
In order to assist start-up and shutdown procedures and to enable the gas turbines to operate should the steam turbine trip, it is equipped with HP, IP an LP bypass systems to discharge 100% of the production capacity of the heat recovery steam generator.
- Condensed flow: 200 l/s.
- Exchanged heat: 471.000 kJ/s.
- Design pressure: 44,5 mbar.
- Cooling water temperature: 19 °C.
- Heat jump in cooling water: 8 °C.
- Dimensions: 19X8,6X8,4(h)m.
- Absolute weight: 260 t.
The single-pass steam surface condenser is fitted with titanium pipes and a seawater cooling circuit. It has been designed, manufactured and tested in accordance with the Heat Exchange Institute (HEI) Standard. The plant has been designed to condense the maximum exhaust steam flow from the steam turbine, receive the drain-off from the steam system and to condense the steam flows from the HP, IP and LP bypass systems during the start-up of the heat recovery steam generator, the start-up of the turbine and the tripping of the steam turbine.
The water boxes and the condenser pipes have been designed and hydraulically tested to withstand the pressures exerted as a result of a possible surge in the water circuit.