Steam turbine
The steam turbine is of the condensing type with two casings, produced by the Steam Turbine Factory ABB from the town of Karlovac, Croatia. One casing comprises high and medium pressure. The low pressure casing is of the double-flow inlet type with direct steam exhaust into the condenser. The steam turbine comprises seven levels of unregulated extraction used for heating the boiler feedwater and the air heater.
Fresh steam enters the steam turbine through stop and control valves and expands through a group of high pressure stages. From the high pressure section of the steam turbine, steam comes into the reheater. After additional heating, steam flows through appropriate stop and control valves and comes into the medium pressure section of the steam turbine where it expands through a group of medium pressure stages. After release from the medium pressure part, steam flows into the low pressure double circulating casing. The exhaust steam is condensed in the surface condenser, while the condensate is sent back to the thermal cycle by condensate pumps.
The condenser is cooled by sea water. The sea cooling-water pumping station is placed in Plomin Bay, some 2.5 km away from the Plant. Pumps take water from a depth of 25 m and pump it into an open concrete water duct where the water flows by gravity to the filter station situated by the Plant. Water flows through closed piping from the filter station to the Plant.
The main technical data: gross steam turbine power (measured on the generator terminals) 210 MW unit auxiliaries 18.8 MW net thermal efficiency of the unit >37% condenser pressure 4.6 kPa sea cooling-water flow 8.4 m3/s.
COAL SUPPLY SYSTEM
The coal is brought by a ship of the Panamax type with a capacity of 60,000 tons into Plomin Bay where the quay 210 m long is placed.
Unloading is performed by a closed ship-worm-type unloader that moves on rails along the quay. From the vessel unloader coal comes to the rubber quay conveyor that transports it to the weighing machine and the magnetic separator. From there to the coal depot, coal is transported by the so-called “tube” conveyor.
Storing on the depot and taking of coal for further transport to the boiler bunkers is performed by a combined loader/ unloader that moves on rails along the depot.