Generators cooling systems?

Question

a) Describe the constructive details and the materials of a typical hydrogen-cooled generator (rotor, stator, etc.). b) Which auxiliary systems are necessary for the operation of such a generator? Why? c) Which cooling alternatives to a hydrogen cooling system are there for larger generators?

Answer 1

Never heard of hydrogen cooling before (perhaps it's used in generators using superconducting materials?)

I'd guess all the parts which are to be cooled would be bathed in liquid hydrogen. Alternatively the hydrogen would flow in pipes. The hydrogen would boil absorbing heat. Would then need to be some way of getting the gaseous hydrogen out safely

A pressure/flow valve would be needed to regulate the rate the hydrogen enters the system. Safety would require some means of purging the hydrogen from the generator, and reducing the risk of a hydrogen/oxygen explosion (perhaps Helium, Nitrogen etc?) Also would need good seals to make sure the hydrogen didn't leak in places you didn't want it. Also would need some way of dealing with excess gaseous hydrogen (flame tower?)

If you don't need the low temperatures, but want evaporative cooling I'd try to use (pure) water running in completely enclosed pipes. It's difficult to beat water's thermal properties, but other liquids/gases could have more desirable properties for particular apps (CO2, NH3, other refrigerants?). Probably would need to consider things things like BPs, heat capacities, and viscosity. (turbo generators whizz around fairly fast, want to keep turbulence/drag to a minimum!)

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Thanks wingsdjf! Didn't realise it was gaseous hydrogen. running around as a coolant, in a sealed system.

a) probably aerodynamically shaped to allow gas to flow easily though it (may be a bit different from ones for air)

b) If the rotor/stator doesn't have a "fan" built into it then an external fan to push the gas through. ducting to/from a heat exchanger(to get the heat out of the gas), probably also a thermostat to turn fan on/off. Some kind of pressure relief valve. purging system as above.

Answer 2

Google them.

Hydrogen cooled generators better than air cooled due to superior hydrogen properties:

http://www.gepower.com/prod_serv/product...

Larger generators are liquid cooled:

http://www.gepower.com/prod_serv/product...