The plant also comprises the following main auxiliary systems:
Main cooling system
The main cooling system supplies seawater to cool the condenser and the closed cooling water circuit.
It comprises a filter system consisting of fixed and moving grilles (2×50%) and two water circulation pumps (2×50%). It also has a smaller auxiliary pump used for cooling during plant shutdowns.
If one of the filter systems breaks down or needs to be serviced, the plant can continue to function at full capacity with only one filter unit operating.
If one of the water circulation pumps breaks down, the plant can continue at full capacity with a reduction in the power of the steam turbine through loss of vacuum in the condenser.
The system also comprises a pump located in the seawater tank which provides minimum cooling services when the plant is not operating.
The cooling water system also includes a “Tapproge” condenser cleaning system.
Auxiliary cooling circuit
The closed auxiliary cooling circuit serves equipment in the plant that requires a cooling source.
It essentially consists of a raised tank, circulation pumps (3 x 50%), plate-type heat exchangers (2×100%) , pipes, valves, etc.
The system uses demineralised water which has a corrosion inhibitor added to it.
The raised tank is used as an expansion tank and to keep the circuit in overpressure.
Natural gas system
Natural gas is supplied from the regasification terminal (BBG). The gas enters the BBE plant at a single point on the perimeter after passing through the regulating and metering station on the BBG site (2 x 100% lines).
Two fine-mesh filters (2×100%) are installed upstream from the gas turbine.
Two gas heaters (one for each turbine) are programmed to operate before the gas is injected in the turbine for the purposes of improving plant efficiency.
Compressed air system
The compressed air system comprises oil-free centrifugal compressors (2×100%) and two air circuits, one for the instruments and the other for the service system. A storage unit is installed in each of the circuits.
The instrument air circuit comprises a drying unit (2×100%).
Although the two circuits are connected to each other, if the pressure in the services air circuit drops it is cut off and priority is given to the instrument air circuit.
The demineralisation plant, which consists of two demineralisation lines (2×100%), produces high-purity demineralised water.
The plant treats drinking water from the Consorcio de Aguas del Gran Bilbao network. The demineralised water is stored in two 500 m3 tanks.
Waste treatment plant
The various types of water produced at the plant are separated into four categories for treatment prior to its disposal: oily water, process water, rain water and waste water.
Chemical dosing unit
Phosphates are added in the boiler drums. The system comprises six piston dosing pumps, one for each boiler drum, in addition to a reserve pump.
Proportioning of hydrazine and ammonia is carried out the degasifier and is driven by condenser pumps. Each system features two double diaphragm pumps (2×100%).
The chemical dosing units are mounted on a bed and consist of a diluting tank, pumps to fill the tank, a stirring paddle, dosing pumps, etc.
Chlorine and bromide is dispensed in the water circuit by five pumps located in the pump house.
The water and steam samples are taken from the water/steam cycle. The samples are conditioned, analysed and monitored to ensure the plant operates reliably and safely. The analyser is fitted on a sample rack in a room adjacent to the chemical laboratory.
Monitoring of emissions
The plant is equipped with a complete gas emission monitoring system for measuring SO2, CO, CO2, NOx in line with the standards and regulations currently in force.