PURPOSE: To provide a steam temperature controlling technique for a composite power generation plant which can control the steam temperature to a same constant value as a rated point in the partial load running without pouring in spray water.
CONSTITUTION: The deviation of a actual steam received heat amount calculated from a set value 89 of steam side heat receiving energy corresponding to loads required by steam using facilities 30, 32 and the detecting value of steam temperature Ts in an exhaust heat recovering boiler 11 is calculated, and at least one of fuel flow and compressor passing air flow for satisfying a limiting condition for cancelling the deviation and fixing burning temperature Texh and steam temperature Ts from a rated point to partial load is calculated. At least one of the openings of a fuel flow adjusting valve 6 of a gas turbine 1 and the opening of a compressor inlet guide blade 4 is controlled according to the calculated value.
SHIMANE YASUSHI
MATSUMURA JUBE
AKIYAMA KOSEI
HITACHI ENG CO LTD