Turbine Generator Set
GE Steam Power Systems will deliver Hanhikivi 1 unit’s turbine generator set. The set consists of a high pressure turbine, intermediate pressure turbine, three low pressure turbines and a generator which is on the same shaft as the turbines.
- The turbine-generator is based on Alstom’s technology: turbine is based on Arabelle technology and generator is Gigatop 4 technology.
- Overall length almost 80 metres
- The whole turbine-generator weights almost 2500 tons (high and intermediate pressure turbines weight about 450 tons and three low pressure turbines and the generator weight about 500-600 tons each)
- The length of the low pressure turbine's last stage blades is about 1.8 metres and the span almost 6 meters
- The turbine-generator shaft will rotate 1500 rpm
- The capacity is 1200 megawatts and the plant will produce altogether about 10 TWh per year. This is over twice of the electricity consumption of Helsinki, the capital of Finland, and covers about 13% of Finland’s electricity needs.
The turbine-generator will be manufactured in France. GE Steam Power Systems is a well-known and experienced supplier that bought Alstom’s energy business in 2015. Alstom’s steam turbine-generators with Arabelle (turbine) and Gigatop 4 (generator) technologies have been delivered to a number of nuclear power plants all over the world.
Operating Principle of a Steam Turbine Generator
The turbine generator is a conventional part of a power plant so to say – it is used to convert the steam generated in the reactor island into electricity to be distributed to the national grid.
In practice, almost dry steam from the reactor unit is piped to the turbines. This heat energy makes the turbines rotate and the generator – which is on the same shaft as the turbines – converts the kinetic energy of the turbines into electricity.
Similar type of turbine generators can be found in any other condensing power plants, even if the steam is generated differently, for example, by burning coal.