Patent ID: 7866140

Claim:
A method of purging an exhaust stream from and exhaust gas recirculation (EGR) system, wherein the exhaust stream exits a gas turbine; the method comprising: providing the gas turbine comprising: an inlet, an external combustion system, and an exhaust section; wherein the gas turbine operatively produces an exhaust stream; providing the EGR system comprising: a first zone, a second zone; an EGR skid, an EGR inlet damper, and an EGR outlet damper; wherein the EGR system reduces the level of a constituent within the exhaust stream and facilitates the sequestration and removal of concentrated CO2; providing an EGR purge system for purging the exhaust stream from the EGR system, the EGR purge system comprising: a first purge flow modulation device located within the first zone, and a second purge flow modulation device located within the second zone; wherein first purge flow modulation device and the second purge flow modulation device move a begin fluid through the EGR system to remove remnants of the exhaust stream remaining when the EGR system is not in operation; establishing a pressure differential between the first zone and the second zone of the EGR system; modulating the first purge flow modulation device and the second purge flow modulation device to allow for the exhaust stream to exit the EGR system; and determining whether an oxygen concentration of air within the EGR system is within a range.