clark

Claim 1

IN A REHEAT TURBINE POWERPLANT HAVING CONDUITS CONNECTING IN SERIES STEAM GENERATING MEANS, A HIGH PRESSURE TURBINE, A REHEATER, A LOWER PRESSURE TURBINE, AND CONDENSER, FIRST VALVE MEANS CONTROLLING THE FLOW OF MOTIVE FLUID TO THE HIGH PRESSURE TURBINE, SECOND VALVE MEANS CONTROLLING THE FLOW OF MOTIVE FLUID FROM THE REHEATER TO THE LOWER PRESSURE TURBINE, AND GOVERNING MEANS CONTROLLING THE OPERATION OF THE FIRST AND SECOND VALVE MEANS AND ADAPTED TO CLOSE THEM UPON OCCURRENCE OF A PREDETERMINED OPERATING CONDITION, THE COMBINATION OF BYPASS CONDUIT MEANS WITH BYPASS VALVE MEANS COMMUNICATING BETWEEN THE HIGH PRESSURE TURBINE AND CONDENSER, MEANS CONTROLLED BY SAID GOVERNING MEANS FOR OPENING THE BYPASS VALVE WHEN THE FIRST AND SECOND VALVES ARE CLOSED AND CHECK VALVE MEANS IN THE CONDUIT BETWEEN THE HIGH PRESSURE TURBINE AND REHEATER, WHEREBY THE FLUID TRAPPED BETWEEN THE FIRST VALVE MEANS AND THE CHECK VALVE MEANS IS VENTED TO THE CONDENSER TO PREVENT OVERHEATING OF THE TURBINE COMPONENTS BY FRICTION HEATING OF THE TRAPPED FLUID.