Systems and methods to improve shut-down purge flow in a gas turbine system

Patent metadata

Field	Value
Publication number	US-10082089-B2
Application number	US-201615247146-A
Country	US
Kind code	B2
Filing date	Aug 25, 2016
Priority date	Aug 25, 2016
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

A system includes a controller including a memory storing instructions to perform operations of a power generation system and a processor that executes the instructions. The instructions cause the controller to control purging fluid flow to an inlet of a gas turbine, an exhaust of the gas turbine, or a combustion section of the gas turbine. The instructions cause the controller to receive a first temperature at the inlet, a rotational speed of the gas turbine, and a purging fluid flow rate. The instructions cause the controller to calculate an exhaust flow rate of the system based on at least the first temperature, the rotational speed, and the purging fluid flow rate. The instructions cause the controller to control the system to isolate a fuel source from the gas turbine at a portion of normal operating speed sufficient to achieve a purging volume during coast down.

First claim

The invention claimed is:

1. A system, comprising:
a controller of a gas turbine and heat recovery steam generator (HRSG) system, comprising:
a memory storing instructions to perform operations of the gas turbine and HRSG system; and
a processor configured to execute the instructions, wherein the instructions, when executed by the processor, cause the controller to:
control purging fluid flow from at least one purging fluid flow source to an inlet of a compressor section of a gas turbine of the gas turbine and HRSG system, an exhaust of the gas turbine, or a combustion section of the gas turbine during deceleration of the gas turbine;
receive a first input signal representative of a first temperature at the inlet of the compressor section of the gas turbine, a second input signal representative of a rotational speed of the gas turbine, and a third input signal representative of a purging fluid flow rate during deceleration of the gas turbine of the at least one purging fluid flow source;
calculate an exhaust flow rate of the gas turbine and HRSG system based on at least the first input signal, the second input signal, and the third input signal; and
control the gas turbine and HRSG system, during shut-down of the gas turbine and HRSG system, to isolate a fuel source from the gas turbine at a portion of normal operating speed of the gas turbine sufficient to achieve a predetermined purging volume during coast down of air flow through the gas turbine and HRSG system based on the exhaust flow rate.

2. The system of claim 1 , wherein the instructions, when executed by the processor, cause the controller to receive a fourth input signal representative of a second temperature at an exhaust of the gas turbine or an exhaust stack of an HRSG of the gas turbine and HRSG system, and the exhaust flow rate is based at least in part on the fourth input signal in addition to the first input signal, the second input signal, and the third input signal.

3. The system of claim 1 , wherein controlling the at least one purging fluid flow source to provide the purging fluid flow to the inlet of the gas turbine or to the exhaust of the gas turbine increases the exhaust flow rate of the gas turbine and HRSG system.

4. The system of claim 1 , comprising:
a first temperature sensor that provides the first input signal;
a rotational speed sensor that provides the second input signal; and
a fluid flow sensor that provides the third input signal.

5. The system of claim 1 , wherein the at least one purging fluid flow source comprises a blower, a water wash system, and a diluent source.

6. The system of claim 1 , wherein the at least one purging fluid flow source comprises a diluent source configured to provide diluent flow to the combustion section of the gas turbine.

7. The system of claim 1 , wherein the at least one purging fluid flow source comprises a water wash system, wherein the water wash system is configured to provide a water wash to the inlet of the compressor section of the gas turbine.

8. The system of claim 7 , wherein the instructions, when executed by the processor, cause the controller to control the water wash system to cease providing the water wash to the inlet when the gas turbine reaches a minimum speed beyond which the water wash stops vaporizing.

9. The system of claim 1 , wherein the at least one purging fluid flow source comprises a blower, wherein the blower is configured to provide additional purging fluid flow to the inlet of the compressor section of the gas turbine, to the exhaust of the gas turbine, or to an exhaust stack of an HRSG of the gas turbine and HRSG system.

10. The system of claim 1 , wherein the instructions, when executed by the processor, cause the controller to control the gas turbine and HRSG system to isolate the fuel source from the gas turbine when the purging fluid flow is provided to the gas turbine, and the gas turbine reaches the portion of normal operating speed of the gas turbine sufficient to achieve the purging volume while the gas turbine operates at a speed greater than a minimum purge flow requirement of the gas turbine.

11. A method, comprising:
utilizing a controller to:
control at least one purging fluid flow source to provide a supplemental purging fluid flow to a gas turbine or a heat recovery steam generator (HRSG) of a gas turbine and HRSG system;
receive a first measurement of a first temperature of the gas turbine and HRSG system from a first sensor, wherein the first measurement of the first temperature comprises at least a temperature at an inlet of the gas turbine;
receive a second measurement of a rotational speed of the gas turbine from a second sensor;
receive a third measurement of a supplemental purging fluid flow rate of the supplemental purging fluid flow during deceleration of the gas turbine from a third sensor;
calculate an exhaust volume flow rate of the gas turbine and HRSG system based on at least the first temperature, the rotational speed of the gas turbine, and the purging fluid flow rate;
obtain a purging volume of the gas turbine and HRSG system that is based on at least a volume of an HRSG of the gas turbine and HRSG system; and
control the gas turbine and HRSG system, during shut-down of the gas turbine and HRSG system, to isolate a fuel source from the gas turbine at a portion of normal operating speed of the gas turbine sufficient to achieve the purging volume during coast down of air flow through the gas turbine and HRSG system based on the exhaust volume flow rate.

12. The method of claim 11 , wherein the first sensor comprises a temperature sensor positioned at an inlet of a compressor section of the gas turbine, and the second sensor comprises a rotational speed sensor of the gas turbine.

13. The method of claim 11 , comprising utilizing a controller to receive a fourth measurement of a second temperature of the gas turbine and HRSG system from a fourth sensor, wherein the fourth sensor comprises a temperature sensor positioned at an exhaust of the gas turbine or an exhaust stack of the HRSG, and calculating the exhaust volume flow rate of the gas turbine and HRSG system is based on at least the fourth parameter.

14. The method of claim 11 , wherein the at least one purging fluid flow source comprises a blower, a water wash system, a diluent source, or any combination thereof.

15. The method of claim 11 , wherein the at least one purging fluid flow source provides the supplemental purging fluid flow to an inlet of a compressor section of the gas turbine, to a combustion section of the gas turbine, to an exhaust of the gas turbine, to an exhaust stack of the HRSG, or any combination thereof.

16. A tangible, non-transitory, machine-readable-medium, comprising machine-readable instructions to:
control at least one purging fluid flow source to provide a supplemental purging fluid flow to a gas turbine of a power generation system;
receive a first measurement of a first temperature of the power generation system from a first sensor, wherein the first measurement of the first temperature comprises at least a temperature at an inlet of the gas turbine;
receive a second measurement of a rotational speed of the gas turbine from a second sensor;
receive a third measurement of a supplemental purging fluid flow rate of the supplemental purging fluid flow during deceleration of the gas turbine from a third sensor;
calculate an exhaust flow rate of the power generation system based on at least the first temperature, the rotational speed of the gas turbine, and the supplemental purging fluid flow rate; and
control the po

Assignees

• Gen Electric

Inventors

• Alexander Michael Joseph
• Davis Jr Lewis Berkley
• Snider David August

Classifications

• G05D7/0623

  characterised by the set value given to the control element · CPC title

• G05B2219/34315

  Power supply turning on or shutting off · CPC title

• F02C7/04

  Air intakes for gas-turbine plants or jet-propulsion plants · CPC title

• F01D21/003

  Arrangements for testing or measuring (for measuring vibrations G01H) · CPC title

• F01K13/003

  Arrangements for measuring or testing (in general G01) · CPC title