Patent ID: 7565792

Claim:
A fuel gas heating control equipment comprising: a heater heating a fuel gas to be supplied to a combustor; a first gas system supplying the fuel gas to the heater; a second gas system being diverged in a stage preceding the heater so as to bypass the heater and connected to the first gas system in a subsequent stage to the heater; a temperature-detecting element measuring a gas temperature of mixed fuel gas being produced by mixing a first fuel gas passing through the first gas system and being heated by the heater and a second fuel gas passing through the second gas system without being heated by the heater in a subsequent stage to the heater; a bypass flow control valve adjusting a flow rate of the second fuel gas; wherein the bypass flow control portion is provided with a specified-temperature-determining portion which determines an aimed specified temperature in accordance with an output of a generator, a subtracter which calculates a difference value in accordance with a comparison between the fuel gas temperature measured by the temperature-detecting element and the aimed specified temperature determined by the specified-temperature-determining portion, a gain-determining portion which determines a gain value in accordance with the output of the generator, a time-constant-determining portion which determines the value of a time constant in accordance with the output of the generator, and a PI calculation portion which determines a control input of the bypass flow control valve in accordance with the gain value determined by the gain-determining portion, the value of the time constant determined by the time-constant-determining portion, and the difference value calculated by the subtracter wherein a time constant is specified to be a first time constant when the generator is at a maximum output; and a time constant is specified to be a smaller value than the first time constant during load fluctuations excluding a maximum output of the generator.