Method for controlling cooling system of gas turbine, control device performing the same, and gas turbine plant comprising the control device

Patent metadata

Field	Value
Publication number	US-10465563-B2
Application number	US-201313774409-A
Country	US
Kind code	B2
Filing date	Feb 22, 2013
Priority date	Sep 27, 2012
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

A gas turbine cooling system of the present invention includes a cooler that cools compressed air extracted from an air compressor to make cooling air, a cooling air compressor that supplies the cooling air to a combustion liner of a combustor, and an IGV that regulates a flow rate of the cooling air. The control device of the gas turbine cooling system includes a target value setting part that determines a target value with respect to a flow rate equivalent value of the cooling air according to detected temperature of the cooling air, a correction driving amount calculation part that obtains a correction driving amount which reduces a deviation of detected flow rate equivalent value of the cooling air with respect to the target value, and a drive command output part that outputs a drive command corresponding to the correction driving amount to the IGV.

First claim

What is claimed is:

1. A method for controlling a cooling system of a gas turbine, the cooling system being provided with a cooler which cools compressed air extracted from an air compressor of the gas turbine to make cooling air, and a cooling air compressor that supplies the cooling air to a high temperature portion exposed to a combustion gas in the gas turbine, the method comprising the steps of:
determining a differential pressure target value with respect to a flow rate equivalent value of the cooling air supplied to the high temperature portion corresponding to a detected temperature of the cooling air supplied to the high temperature portion by using a differential pressure target value setting function that determines a relationship between the differential pressure target value and the temperature of the cooling air, the differential pressure target value being a differential pressure between a first pressure at a first position where the compressed air is extracted from the air compressor of the gas turbine and a second pressure at a second position where the cooling air is supplied to the high temperature portion;
determining a preceding driving amount of a cooling air flow regulator using the detected temperature of the cooling air and a preceding driving amount setting function that indicates a relationship between the temperature of the cooling air and the preceding driving amount of the cooling air flow regulator that regulates a flow rate of the cooling air, the preceding driving amount which is used to perform a feed-forward control of the flow rate of the cooling air;
calculating a correction driving amount which reduces a deviation of a detected flow rate equivalent value of the cooling air with respect to the differential pressure target value, as a correction driving amount of the cooling air flow regulator; and
outputting a drive command by which the cooling air flow regulator is driven, the drive command corresponding to the preceding driving amount and the correction driving amount to the cooling air flow regulator.

2. The method for controlling a cooling system of a gas turbine according to claim 1 ,
wherein the differential pressure target value setting function determines a relationship among the differential pressure target value, the temperature of the cooling air, and a gas turbine output equivalent value, and
in the step of determining the differential pressure target value, a differential pressure target value corresponding to the detected temperature of the cooling air and the gas turbine output equivalent value is determined using the differential pressure target value setting function.

3. The method for controlling a cooling system of a gas turbine according to claim 1 ,
wherein the drive command corresponding to a driving amount, in which the correction driving amount is added to the preceding driving amount determined by the step of determining the preceding driving amount, is output as the drive command corresponding to the preceding driving amount and the correction driving amount in the step of outputting the drive command.

4. The method for controlling a cooling system of a gas turbine according to claim 3 ,
wherein the preceding driving amount setting function determines a relationship among the temperature of the cooling air, a gas turbine output equivalent value, and the preceding driving amount of the cooling air flow regulator, and in the step of determining the preceding driving amount, the preceding driving amount corresponding to the detected temperature of the cooling air and the gas turbine output equivalent value is determined using the preceding driving amount setting function.

5. The method for controlling a cooling system of a gas turbine according to claim 1 ,
wherein the cooling air flow regulator is disposed in an inlet port of the cooling air compressor to regulate the flow rate of the cooling air that is sucked by the cooling air compressor.

6. A control device of a cooling system of a gas turbine, the cooling system being provided with a cooler which cools compressed air extracted from an air compressor of the gas turbine to make cooling air, and a cooling air compressor that supplies the cooling air to a high temperature portion exposed to a combustion gas in the gas turbine, a thermometer which detects a temperature of the cooling air supplied to the high temperature portion, and a flow rate equivalent value meter which detects a flow rate equivalent value of the cooling air, comprising:
a differential pressure target value setting unit including a differential pressure target value setting function that indicates a relationship between a differential pressure target value and a temperature of the cooling air, the differential pressure target value setting unit determining the differential pressure target value with respect to the flow rate equivalent value of the cooling air corresponding to the detected temperature of the cooling air, by using the differential pressure target value setting function, the differential pressure target value being a differential pressure between a first pressure at a first position where the compressed air is extracted from the air compressor of the gas turbine and a second pressure at a second position where the cooling air is supplied to the high temperature portion;
a preceding driving amount setting unit that determines a preceding driving amount of a cooling air flow regulator using the detected temperature of the cooling air and a preceding driving amount setting function that indicates a relationship between the temperature of the cooling air and the preceding driving amount of the cooling air flow regulator that regulates a flow rate of the cooling air, the preceding driving amount which is used to perform a feed-forward control of the flow rate of the cooling air;
a correction driving amount calculation unit that obtains a correction driving amount, which reduces a deviation of the detected flow rate equivalent value of the cooling air with respect to the differential pressure target value, as a correction driving amount of the cooling air flow regulator, and that is connected to the differential pressure target value setting unit; and
a drive command output unit that outputs a drive command corresponding to the preceding driving amount and the correction driving amount to the cooling air flow regulator, and that is connected to the correction driving amount calculation unit.

7. The control device of a cooling system of a gas turbine according to claim 6 ,
wherein the differential pressure target value setting function determines a relationship among the differential pressure target value, the temperature of the cooling air, and a gas turbine output equivalent value, and
the differential pressure target value setting unit determines a target value corresponding to the detected temperature of the cooling air and the gas turbine output equivalent value, by using the differential pressure target value setting function.

8. The control device of a cooling system of a gas turbine according to claim 6 ,
wherein the differential pressure target value setting function is a function that indicates a relationship in which the differential pressure target value is increased as the temperature of the cooling air is increased.

9. The control device of a cooling system of a gas turbine according to claim 6 ,
wherein the drive command output unit outputs the drive command corresponding to a driving amount in which the correction driving amount is added to the preceding driving amount determined by the preceding driving amount setting unit.

10. The control device of a cooling system of a gas turbine according to claim 9 ,

Assignees

• Mitsubishi Heavy Ind Ltd
• Mitsubishi Hitachi Power Sys

Inventors

• KUNIHIRO Akihito

Classifications

• F01K19/10 Primary

  Cooling exhaust steam other than by condenser; Rendering exhaust steam invisible · CPC title

• F01K23/10 Primary

  with exhaust fluid of one cycle heating the fluid in another cycle (F01K17/025 takes precedence) · CPC title

• F02C7/185

  Cooling means for reducing the temperature of the cooling air or gas · CPC title

• F02C6/18

  using the waste heat of gas-turbine plants outside the plants themselves, e.g. gas-turbine power heat plants (using waste heat as source of energy for refrigeration plants F25B27/02; using the waste heat of a gasturbine for steam generation or in a steam cycle see F01K23/10) · CPC title

• F02C9/18

  by bleeding, bypassing or acting on variable working fluid interconnections between turbines or compressors or their stages {(F02C3/113 takes precedence)} · CPC title