What is a hydrogen cooler in a steam turbine generator?

A hydrogen cooler in a steam turbine generator is a water-to-hydrogen heat exchanger used to remove heat from the hydrogen gas circulating inside a hydrogen-cooled generator.

Purpose

In large steam turbine generators, hydrogen gas is used as the internal cooling medium. As the generator operates, hydrogen absorbs heat from the rotor, stator windings, and core. The hydrogen cooler transfers this heat to cooling water, keeping the generator within safe operating temperatures.

How it works

• Hot hydrogen gas flows over the outside of finned or bare tubes

• Cooling water flows inside the tubes

• Heat is transferred from hydrogen to water

• The cooled hydrogen is recirculated back into the generator

The hydrogen circuit and water circuit are completely separated.

Why it is important

The hydrogen cooler:

• Maintains stable generator temperature

• Enables higher power output and efficiency

• Reduces windage losses compared with air cooling

• Extends the life of insulation, bearings, and generator components

• Improves overall reliability of the steam turbine generator

Typical design

Hydrogen coolers are usually:

• Finned tube or shell-and-tube heat exchangers

• Installed inside the generator casing or in dedicated cooler compartments

• Designed for high safety standards to prevent hydrogen leakage

In summary, a hydrogen cooler is a critical component that allows large steam turbine generators to operate efficiently and safely using hydrogen as the cooling medium.