Most manufacturer provided generator capability curves usually contain curves with certain parameters at different temperatures(ambient temperature, cold gas temperature, cold air temperature are the ones I've seen the most). What is the difference between ambient and cold gas temperature?

thanks,
nic

 

nic,

There are air-cooled generators and hydrogen-cooled generators. Air temperature is air temperature--the air that's beings used to cool the generator, the "incoming" air if you will.

Hydrogen-cooled generators have gas-to-water heat exchangers('gas' being hydrogen gas), so the temperature of the gas (hydrogen) leaving the gas-to-water heat exchanger is measured.

I would estimate that ambient temperature would be the same as cold air temperature for air-cooled generators.

There are also generators that use air-to-water heat exchangers, and it would seem logical to measure the temperature of the air leaving the heat exchanger.

The temperature of the air/gas being used to cool the generator is helpful when trying to determine the cooling efficiency when troubleshooting generator heating issues. That's why it's important to track (trend) these temperatures because they can tell if the heat exchangers are working correctly or if there is some other problem with cooling flows.