Evaporative cooling technology more suitable for the Three Gorges' generators

The worldwide experience on the operation of large or high speed hydrogenerators with direct water cooling are accepted by both suppliers and utilities, and they are operating satisfactorily even if there are some disadvantages. According to the operational experience on evaporative cooling in China, the most common problems (or disadvantages) encountered with direct water cooling, such as water leakage, manufacturing and installing cost, and extensive maintenance of the water and water purifying system etc., can be eliminated by using the evaporative coolant F113, FF31L or Fla instead of the water. Four machines with evaporative cooling systems have been installed and operated very satisfactorily though their ratings are relatively small. A decision has been made at least one 400 MW hydrogenerator with evaporative cooling system will be manufactured and installed at Lijiaxia power station, Gansu Province, China. Putting this hydrogenerator into operation will further demonstrate the advantages of evaporative cooling-system and dispel the misgivings of the utilities, and finally to push one of the world largest hydrogenerator which are under designing with water cooled stator windings, to use the evaporative cooling technology.