Views: 0 Author: Site Editor Publish Time: 2026-07-21 Origin: Site
Why high-power generators adopt hydrogen cooling instead of air cooling
Air has low thermal conductivity and high wind friction loss. For generators above 200MW, pure air cooling leads to excessive winding temperature, large fan power consumption and limited unit output.
Hydrogen features outstanding thermal performance:
1. Heat transfer efficiency of hydrogen is 7 times higher than air; it rapidly takes away heat from stator windings, rotor and iron core.
2. Low density reduces ventilation wind loss, saving auxiliary power consumption and improving overall generator efficiency.
3. Inert hydrogen avoids winding oxidation aging, extending insulation service life under long-term full-load operation.
Therefore, all large-capacity turbo generators (200MW, 300MW, 600MW, 1000MW thermal & nuclear power units universally adopt closed hydrogen circulation cooling systems matched with fin-tube hydrogen surface coolers.
Core working principle of hydrogen cooler
1. Hot hydrogen absorbing generator internal heat flows through the finned tube bundle of the hydrogen cooler.
2. Closed-cycle cooling water circulates inside metal tubes and conducts heat exchange with hydrogen outside tubes.
3. Cooled low-temperature hydrogen flows back into the generator to continuously cool electromagnetic components.
4. The cooling water carrying waste heat is sent to the secondary cooling water heat exchanger for heat dissipation to the circulating water system.
Supporting matching auxiliary cooling equipment for high-power hydrogen-cooled generators
1. Generator seal oil hydrogen side cooler: Cool hydrogen-side sealing oil to maintain shaft sealing and prevent hydrogen escape
2. Stator water heat exchanger: Cool deionized water circulating inside hollow stator bars
3. Cooling water heat exchanger: Isolate raw circulating water to avoid scaling and corrosion inside hydrogen coolers
