I am a new engineer at this company and don't know the background of the GE Frame 6 (45MW) unit. But I heard after we installed the new IGV, the minimum load has to run at 18 MW instead of 5MW.

Please explain why this is.
Thanks!

 

John Look,

Hmmm.... Doesn't sound logical does it?

It would seem if there was a requirement for Minimum Load to be 18 MW, that would mean that during starting and loading the load would have to increase at a pretty fast rate to get to and maintain 18 MW. Breaker closure usually occurs around 3.375 MW (100.3% TNH for a $% MW machine), so are you also being told the unit must be loaded very quickly to 18 MW?

Could this Minimum Load Requirement be in place because the unit is equipped with DLN-I combustors and this the approximate lowest load the unit can reach while remaining in Pre-Mix Steady State Combustion mode--the mode with the lowest emissions?

Unless there is something very unusual about the new IGVs, and/or the application (some kind of "science experiment" going on where your site has agreed to be a test site for some GE development program), then this requirement to not run below 22% of rated power seems very unusual. Unless there's more to this story than we've been told.