Patent ID: 8386147
Filing Date: 2013-02-26
Classification: F02C,F05D

Abstract:
1. An apparatus for controlling intake air heating of a gas turbine comprising: a heat exchanger which is supplied with self-generated steam whose supply amount is controlled in response to a valve opening of a self-generated steam control valve and auxiliary steam whose supply amount is controlled in response to a valve opening of an auxiliary steam control valve to heat air which is taken by a gas turbine utilizing supplied steam; a thermometer which measures the temperature of air which is heated by the heat exchanger and taken by the gas turbine; a steam source switching signal generating unit which outputs a first steam source switching signal when output of a generator rotationally driven by the gas turbine decreases from a value equal to or higher than a predetermined prescribed value to a value less than the prescribed value and which outputs a second steam source switching signal when the output of the generator increases from a value less than the predetermined prescribed value to a value equal to or higher than the prescribed value; a self-generated steam usage coefficient generating unit which outputs a self-generated steam usage coefficient whose value gradually changes from 1 to 0 along time elapsing in a predetermined set time when the first steam source switching signal is outputted and whose value gradually changes from 0 to 1 along time elapsing in a predetermined set time when the second steam source switching signal is outputted; a self-generated steam control unit which feeds a self-generated steam correction valve opening instruction obtained by adding a self-generated steam valve opening correction instruction for performing feedback control so as to make a deviation between a measurement temperature measured by the thermometer and a preset target temperature zero and a self-generated steam valve opening preceding instruction for performing preceding control such that the measurement temperature reaches the target temperature to the self-generated steam control valve, thereby controlling a valve opening of the self-generated steam control valve; and an auxiliary steam control unit which feeds an auxiliary steam correction valve opening instruction obtained by adding an auxiliary steam valve opening correction instruction for performing feedback control so as to make a deviation between the measurement temperature and the preset target temperature zero and an auxiliary steam valve opening preceding instruction for performing preceding control such that the measurement temperature reaches the target temperature to the auxiliary steam control valve, thereby, controlling a valve opening of the auxiliary steam control valve, wherein when the first steam source switching signal is outputted, the self-generated steam control unit maintains a value of the self-generated steam correction valve opening instruction at a time point when the first steam source switching signal is outputted and gradually decreases the value of the self-generated steam correction valve opening instruction from a held value of the self-generated steam correction valve opening instruction to zero in a predetermined set time, while the auxiliary steam control unit controls a valve opening of the auxiliary steam control valve according to an auxiliary steam adjustment valve opening instruction obtained by multiplying the auxiliary steam correction valve opening instruction by a difference value obtained from subtracting the self-generating steam usage coefficient from a value of 1, and when the second steam source switching signal is outputted, the auxiliary steam control unit maintains a value of the auxiliary steam correction valve opening instruction at a time point when the second steam source switching signal is outputted and gradually decreases the value of the auxiliary steam correction valve opening instruction from the held value of the self-generated steam correction valve opening instruction to 0 in a predetermined set time, while the self-generated steam control unit controls a valve opening of the self-generated steam control valve according to a self-generated steam adjustment valve opening instruction obtained by multiplying the self-generated steam correction valve opening instruction by the self-generated steam usage coefficient.