REHEATER PROTECTION UPON LOSS OF LOAD

STOPAGGE OF STEAM FLOW THROUGH THE REHEATER WHEN THE ENTERING GAS TEMPERATURE IS HIGH CAN RESULT IN OVERHEATING AND DAMAGE TO THE REHEATER TUBING.TO PREVENT THIS CONDITION,MEASURES TO BE TAKEN.TURBINE VALVE CLOSURE-IF LOSS OF LOAD SHOULD CAUSE THE TURBINE VALVES TO CLOSE.ALL FUEL SHOULD BE TRIPPED AUTOMATICALLY.UNDER A MFT RESULTING FROM TURBINE CONTROL VALVE CLOSURE AN IMMEDIATE RESTART IS IS FEASIBLE IN SOME INSTANCES,AS THE TURBINE IS STILL ROLLING AND WILL BE AVAILABLE TO TAKE STEAM AS SSON AS THE GOVERNER HAS THE TURBINE SPEED UNDER CONTROL.

TURBINE TRIP-IF LOSS OF LOAD OCCURS IN WHICH THE TURBINE IS TRIPPED THE REHEATER SHOULD BE AUTOMATICALLY AND INSTANTANEOUSLY TRIPPED.
REHEATER SAFETY VAVLES WILL PROTECT AGAINST OVERPRESSURE IN THE REHEATER.THE REHEATER CONDENSER DRAINS SHOULD BE OPENED TO VACUATE THE STEAM IN THE REHEATER.