System and method for load control with diffusion combustion in a stoichiometric exhaust gas recirculation gas turbine system

Patent metadata

Field	Value
Publication number	US-10215412-B2
Application number	US-201314067563-A
Country	US
Kind code	B2
Filing date	Oct 30, 2013
Priority date	Nov 2, 2012
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

A system is provided with a turbine combustor having a first diffusion fuel nozzle, wherein the first diffusion fuel nozzle is configured to produce a diffusion flame. The system includes a turbine driven by combustion products from the diffusion flame in the turbine combustor. The system also includes an exhaust gas compressor, wherein the exhaust gas compressor is configured to compress and route an exhaust gas from the turbine to the turbine combustor along an exhaust recirculation path. In addition, the system includes a control system configured to control flow rates of at least one oxidant and at least one fuel to the turbine combustor in a stoichiometric control mode and a non-stoichiometric control mode, wherein the stoichiometric control mode is configured to change the flow rates and provide a substantially stoichiometric ratio of the at least one fuel with the at least one oxidant, and the non-stoichiometric control mode is configured to change the flow rates and provide a non-stoichiometric ratio of the at least one fuel with the at least one oxidant.

First claim

The invention claimed is:

1. A system, comprising:
an oxidant compressor configured to produce a compressed stream of an oxidant;
a turbine combustor receiving the compressed stream of the oxidant from the oxidant compressor and comprising a first diffusion fuel nozzle and a second diffusion fuel nozzle, wherein the first diffusion fuel nozzle is configured to inject separate streams of a first portion of the oxidant, a first diluent, and a first fuel at first flow rates into the turbine combustor to produce a first diffusion flame at a first substantially stoichiometric ratio, and wherein the second diffusion fuel nozzle is configured to inject separate streams of a second portion of the oxidant, a second diluent, and a second fuel at second flow rates into the turbine combustor to produce a second diffusion flame at a second substantially stoichiometric ratio;
a turbine driven by combustion products from the first and second diffusion flames in the turbine combustor;
an exhaust gas compressor, wherein the exhaust gas compressor is configured to compress and route only an exhaust gas from the turbine to the turbine combustor along an exhaust recirculation path, and wherein at least a portion of the exhaust gas is directed to the first diffusion fuel nozzle as the first diluent and to the second diffusion fuel nozzle as the second diluent;
wherein a first ratio of the first flow rates of the first fuel and the first portion of the oxidant through the first diffusion fuel nozzle is different from a second ratio of the second flow rates of the second fuel and the second portion of the oxidant through the second diffusion fuel nozzle, and wherein the first ratio of the first flow rates of the first fuel and the first portion of the oxidant through the first diffusion fuel nozzle produce the first diffusion flame at the first substantially stoichiometric ratio and the second ratio of the second flow rates of the second fuel and the second portion of the oxidant through the second diffusion fuel nozzle produce the second diffusion flame at the second substantially stoichiometric ratio;
wherein the first diffusion fuel nozzle comprises a first passage, a second passage, a third passage, and a fourth passage configured to inject separate streams of the first portion of the oxidant, the first diluent, and the first fuel into the turbine combustor to produce the first diffusion flame at the stoichiometric ratio.

2. The system of claim 1 , wherein the first substantially stoichiometric ratio and the second substantially stoichiometric ratio each comprise an equivalence ratio of between 0.95 and 1.05.

3. The system of claim 1 , wherein the first diffusion fuel nozzle is coupled to a first fluid supply circuit and the second diffusion fuel nozzle is coupled to a second fluid supply circuit, and the first flow rates are independent of the second flow rates.

4. The system of claim 1 , wherein the first passage, the second passage, the third passage, and the fourth passage are isolated from one another along a length of the first diffusion fuel nozzle.

5. The system of claim 1 , wherein the first passage, the second passage, the third passage, and the fourth passage are concentrically arranged with one another.

6. A method, comprising:
compressing an oxidant with an oxidant compressor to produce a compressed stream of an oxidant;
injecting a first portion of the compressed stream of the oxidant, a first diluent, and a first fuel as separate streams at first flow rates into a chamber of a turbine combustor using a first diffusion fuel nozzle, wherein the first portion of the oxidant, the first diluent, and the first fuel mix and combust as a first diffusion flame to generate first combustion products at a first substantially stoichiometric ratio;
injecting a second portion of the compressed stream of the oxidant, a second diluent, and a second fuel as separate streams at second flow rates into the chamber of the turbine combustor using a second diffusion fuel nozzle, wherein the second portion of the oxidant, the second diluent, and the second fuel mix and combust as a second diffusion flame to generate second combustion products at a second substantially stoichiometric ratio;
driving a turbine with the first and second combustion products and outputting an exhaust gas;
recirculating the exhaust gas along an exhaust recirculation path to an exhaust gas compressor;
compressing and routing only the exhaust pas to the turbine combustor with the exhaust gas compressor, wherein at least a portion of the exhaust gas is directed to the first diffusion fuel nozzle as the first diluent and to the second diffusion fuel nozzle as the second diluent;
wherein a first ratio of the first flow rates of the first fuel and the first portion of the oxidant through the first diffusion fuel nozzle is different from a second ratio of the second flow rates of the second fuel and the second portion of the oxidant through the second diffusion fuel nozzle, and wherein the first ratio of the first flow rates of the first fuel and the first portion of the oxidant through the first diffusion fuel nozzle produce the first diffusion flame at the first substantially stoichiometric ratio and the second ratio of the second flow rates of the second fuel and the second portion of the oxidant through the second diffusion fuel nozzle produce the second diffusion flame at the second substantially stoichiometric ratio; and
wherein injecting the first portion of the compressed stream of the oxidant, the first diluent, and the first fuel as separate streams into the chamber of the turbine combustor using the first diffusion fuel nozzle comprises separately flowing the first portion of the compressed stream of the oxidant, the first diluent, and the first fuel through a first passage, a second passage, a third passage, or a fourth passage of the first diffusion fuel nozzle.

7. The method of claim 6 , wherein the first substantially stoichiometric ratio and the second substantially stoichiometric ratio each comprise an equivalence ratio of between 0.95 and 1.05.

8. The method of claim 6 , comprising changing the first flow rates, the second flow rates, or both from a first set of flow rates to a second set of flow rates while maintaining the first substantially stoichiometric ratio and the second substantially stoichiometric ratio, thereby changing a power output of the turbine from a first power output to a second power output.

9. The method of claim 8 , wherein the second set of flow rates is less than the first set of flow rates, and the second power output is less than the first power output, or wherein the second set of flow rates is greater than the first set of flow rates, and the second power output is greater than the first power output.

10. The method of claim 8 , comprising maintaining emissions in the exhaust gas within one or more target emissions ranges while changing the first flow rates, the second flow rates, or both from the first set of flow rates to the second set of flow rates.

11. The method of claim 6 , comprising changing the first flow rates, the second flow rates, or both among a plurality of sets of flow rates while:
maintaining the substantially stoichiometric ratio;
progressively reducing the first flow rates, the second flow rates, or both among the plurality of sets of flow rates;
progressively reducing a power output of the turbine among a plurality of power outputs; and
maintaining emissions in the exhaust gas within one or more target emissions ranges.

12. The method of claim 6 , comprising:
progressively changing the first flow rates, the second flow rates, or both among a plurality of sets of

Assignees

• Gen Electric
• Exxonmobil Upstream Res Co

Inventors

• Huntington Richard A
• Dhanuka Sulabh K
• Slobodyanskiy Ilya Aleksandrovich

Classifications

• F23C9/00

  Combustion apparatus characterised by arrangements for returning combustion products or flue gases to the combustion chamber (fluidised bed combustion apparatus with means for recirculation of particles entrained from the bed F23C10/02; fluidised bed combustion apparatus with devices for removal and partial reintroduction of material from the bed F23C10/26) · CPC title

• F23R3/28 Primary

  characterised by the fuel supply (burners F23D) · CPC title

• F02C1/06

  using reheated exhaust gas (F02C1/08 takes precedence) · CPC title

• F23J2215/50

  Carbon dioxide · CPC title

• F23J15/006

  Layout of treatment plant · CPC title