The most recent part of the process facility is
located close to the larger GTGs, and all of the process steam
requirements are produced from the associated HRSGs.
Since it is not possible, or desirable, to regulate the GTG
output based on process steam requirements, it was
necessary to fit the boilers with auxiliary burners [3] for both
supplementary and independent operation. The design
premise was that the maximum steam demand should be met
by 1 GTG operating at full load supplemented by auxiliary
firing, or from 2 HRSGs operating independently as boilers
with no GTG exhaust heat input, including an automatic fast
changeover between integrated and independent HRSG
configuration.