Apparatus and method of operating a forced flow once-through vapor generating power plant

Claim 1

IN A FORCED FLOW MODIFIED ONCE-THROUGH TYPE STEAM POWER PLANT HAVING A STEAM GENERATING SECTION, A STEAM SUPERHEATING SECTION AND A STEAM TURBINE SERIALLY CONNECTED IN THE ORDER NAMED, MEANS FOR SUPPLYING FEEDWATER TO SAID STEAM GENERATING SECTION, MEANS DE-AERATING THE FEEDWATER, MEANS FOR STARTING UP SAID STEAM BOILER AND SAID TURBINE WITH ONLY STEAM FLOWING THROUGH SAID STEAM SUPERHEATING SECTION COMPRISING A CUTOFF VALVE ARRANGED TO CONTROL FLUID FLOW BETWEEN SAID STEAM GENERATING AND STEAM SUPERHEATING SECTIONS, A SOURCE OF AUXILIARY STEAM, A CONDUIT CONNECTING SAID AUXILIARY STEAM SOURCE WITH SAID DE-AERATING MEANS AND ARRANGED TO CONVEY STEAM FROM SAID STEAM SOURCE TO SAID DE-AERATING MEANS WHEN SAID CUTOFF VALVE IS CLOSED, A CONDUIT CONNECTING SAID SUPERHEATING SECTION TO SAID AUXILIARY STEAM SOURCE AND ARRANGED TO CONVEY STEAM FROM SAID AUXILIARY STEAM SOURCE TO SAID SUPERHEATING SECTION AND TO SAID TURBINE WHEN SAID CUTOFF VALVE IS CLOSED, A RECIRCULATING CONDUIT CONNECTING A POINT DOWNSTREAM OF SAID STEAM GENERATING SECTION WITH RESPECT TO WATER FLOW WITH A POINT UPSTREAM THEREOF, AND MEANS FOR RECIRCULATING WATER THROUGH SAID RECIRCULATING CONDUIT AROUND SAID STEAM GENERATING SECTION WHEN SAID CUTOFF VALVE IS CLOSED.