DEESIDE POWER - OPERATIONS - Gas Turbine
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Energy from burning natural gas turns the turbine.

Deeside has two Alstom Power plc GT13E2 gas turbines which each weigh 350 tonnes and can produce 166 megawatts of electricity. They work by compressing air, burning gas to increase the air's temperature and then using the high pressure, high temperature combustion gases to drive a turbine connected to a generator.

Air is drawn in through the intake filters at the front of the building at a rate of 25 tonnes a minute and is compressed to about 15 times atmospheric pressure in the 21-stage compressor. It is then mixed with natural gas and burned in the combustion chamber through an annular combustor with 72 double cone burners arranged in a 4-row ring pattern. The gas is ignited using two spark plugs, similar to those found in a car.

The power turbine is started by spinning it at 435 revolutions a minute using the generator as a starter motor. Then the hot gases at a temperature of 1100ºC are directed from the combustion chamber to the turbine where they expand, cool and give up some of their energy to turn the blades of the turbine. As the turbine shaft rotates at 3000 times a minute it turns the compressor and the generator, which is connected to the main shaft at the compressor end.

The type WY21Z generator, weighing 182 tonnes, consists of:-

The Rotor

A Large Electromagnet

(This produces a rotating electric field and generates electricity in the stator.)

The Stator

(A series of insulated copper conductor bars.)

The electricity is produced at a voltage of 16,000 volts, then stepped up to 400,000 volts in the generator transformer before being passed to the National Grid substation at Connah's Quay for transmission around the country.

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