JP2015531450A - How to operate a multi-stage flame sheet combustor - Google Patents

Abstract

The present invention discloses a novel method for controlling a gas turbine engine to reduce emissions levels when power demand from the gas turbine engine is reduced. The operating system provides a series of operating modes for the gas turbine combustor, through which fuel is staged to gradually increase engine power, but harmful emissions such as carbon monoxide. Is maintained at an acceptable level.

Description

  The present invention generally relates to a method of operating a combustion system to reduce emissions in a gas turbine combustor. More specifically, improvements in fuel staging for combustors are provided.

BACKGROUND OF THE INVENTION In an effort to reduce the amount of pollutant emissions from gas-driven turbines, government ministries have enacted a number of rules that require a reduction in the amount of nitrogen oxides (NOx) and carbon monoxide (CO). . Less combustion emissions can often be attributed to a more efficient combustion process, particularly with respect to fuel injector position and mixing efficiency.

  Early combustion systems utilized diffusion nozzles. In a diffusion nozzle, fuel is mixed with air outside the fuel nozzle by diffusion near the flame area. Diffusion nozzles generate large amounts of emissions by stoichiometric combustion of fuel and air at high temperatures to maintain sufficient combustor stability and low combustion dynamics.

  An improvement in combustion technology is the use of premixing, where fuel and air are mixed prior to combustion to form a homogeneous mixture. A homogeneous mixture burns at a lower temperature than a diffusion flame and generates less NOx emissions. Premixing can take place inside or outside the fuel nozzle as long as it is upstream of the combustion zone. An example of a conventional premix combustor is shown in FIG. The combustor 8 has a plurality of fuel nozzles 18, and each fuel nozzle 18 injects fuel into a premixing cavity 19. In the premix cavity 19, the fuel enters the combustion chamber 20 after being mixed with the compressed air 6 from the plenum 10. By premixing the fuel and air before combustion, the fuel and air form a more homogeneous mixture, and this homogeneous mixture burns more completely, resulting in less emissions. However, in this configuration, the fuel is injected in relatively the same plane of the combustor, hindering any possible improvement by changing the mixing length.

  An alternative to premixing and less emissions can be achieved with multiple combustion stages, which increases premixing as the load increases. Referring now to FIG. 2, an example of a conventional multistage combustor is shown. The combustor 30 has a first combustion chamber 31 and a second combustion chamber 32 separated by a venturi 33 having a narrow throat region 34. Depending on the load conditions, combustion can occur in the first or second combustion chamber or in both combustion chambers, but the fuel injected through the nozzle region 35 is first combusted before burning in the second combustion chamber 32. The lowest emission level occurs when fully mixed with compressed air in the combustion chamber 31 of the engine. Thus, this multi-stage combustor with a venturi tube is more effective at higher load conditions.

  Gas turbine engines are required to operate at various power settings. When a gas turbine engine is connected to drive a generator, the required output of the engine is often measured according to the magnitude of the load on the generator or the power that must be generated by the generator. The full load condition is a state in which the maximum output is drawn from the generator, and therefore requires the maximum power from the engine to drive the generator. This is the most common operating condition for onshore gas turbines used for power generation. However, often the power demand does not require the full capacity of the generator and the operator wants to run the engine at a lower load setting, so only the required load is generated, thereby saving fuel and reducing operating costs. Have reduced. Conventional combustion systems are known to be unstable at lower load settings, particularly less than 50%, and also produce unacceptable levels of NOx and CO emissions. This is mainly due to the fact that most combustion systems are staged for the most efficient operation at high load settings. The combination of potentially unstable combustion and higher emissions often prevents engine operators from operating the engine at lower load settings, causing the engine to operate at higher settings, thereby providing additional The fuel is burned or shut down, thereby losing valuable revenue that could have been generated from part load demand.

  One problem with stopping the engine is that additional cycles are performed by the engine hardware. A cycle is generally defined as the engine passing through a normal operating envelope. That is, by stopping the engine, the engine hardware accumulates additional cycles. Engine manufacturers typically rate hardware life with respect to operating hours or equivalent operating cycles. Thus, performing additional cycles can reduce hardware life, which requires early repair or replacement at the expense of the engine operator. What is needed can provide flame stability and low emissions benefits at partial and full load conditions, which allows the engine to operate efficiently at lower load conditions, which A system that eliminates fuel disposal when no load operation is required or generates an additional cycle in engine hardware upon shutdown.

SUMMARY OF THE INVENTION The present invention discloses a method of operating a gas turbine engine, and more particularly a method of operating a gas turbine combustor to improve engine turndown efficiency. In one embodiment of the invention, a method for operating a combustor includes supplying fuel to a pilot nozzle, igniting fuel from the pilot nozzle, and supplying additional fuel to a pilot tune injector. The method supplies fuel to a first portion of a combustor main fuel injector, ignites this fuel to form a main combustion flame, supplies fuel to a second portion of the combustor main fuel injector, It is also disclosed to ignite this fuel to maintain the main combustion flame.

  In an alternative embodiment of the present invention, a computerized method for staging fuel in a gas turbine combustor is provided. This method provides a method of operating a combustor having a pilot nozzle, a set of pilot tune injectors, and a main set of fuel injectors in four different modes of operation. Each successive mode of operation adds additional fuel flow to the combustor.

  In yet another embodiment of the present invention, a method for improving the turndown capability of a gas turbine combustor while controlling carbon monoxide production is disclosed. The method regulates fuel flow to the first and second portions of the annular array of fuel injectors, regulates fuel flow to the one or more injectors in the core section of the gas turbine combustor, The core section has a pilot nozzle and a set of injectors for tuning the pilot nozzle. By adjusting these fuel circuits, the overall fuel flow can be reduced, and turndown capability can be maintained while maintaining operation within an acceptable emission level range.

  In another embodiment of the present invention, a method of operating a combustor includes supplying fuel to a stage of a pilot fuel nozzle and a pilot tune injector. The fuel injected through these circuits is ignited and then additional fuel is added through the first portion of the main fuel injector, which is ignited and generates a main combustion flame. The fuel is then supplied to the second portion of the main fuel injector, and this additional fuel is then ignited to further maintain the main combustion flame.

  In an additional embodiment of the present invention, a method for operating a combustor includes supplying fuel to a pilot nozzle and igniting the fuel to form a pilot. By supplying fuel to the first portion of the main fuel injector, additional fuel is added to the combustor. Fuel added through the first portion of the main injector is ignited to form a main combustion flame. Fuel is then supplied to the second portion of the main fuel injector and ignited to further maintain the main combustion flame.

  Additional advantages and features of the present invention will be set forth in part in the description that follows, and in part will be apparent to those of ordinary skill in the art upon review of the following description or may be learned by practice of the invention. The present invention will now be described with particular reference to the accompanying drawings.

  The present invention will be described in detail below with reference to the accompanying drawings.

It is sectional drawing of the conventional gas turbine combustor. It is sectional drawing of the conventional alternative combustor. 1 is a cross-sectional view of a gas turbine combustor according to one embodiment of the present invention. FIG. 2 is an end view of the gas turbine combustor of FIG. 1 according to one embodiment of the present invention. 2 is a flow diagram illustrating a method for controlling a gas turbine according to one embodiment of the present invention. 1 is a cross-sectional view of a gas turbine combustor according to an embodiment of the present invention operating in a first mode. FIG. 2 is a cross-sectional view of a gas turbine combustor according to one embodiment of the present invention operating in a second mode. FIG. FIG. 4 is a cross-sectional view of a gas turbine combustor operating in a third mode according to one embodiment of the present invention. 6 is a cross-sectional view of a gas turbine combustor according to one embodiment of the present invention operating in a fourth mode. FIG. 6D is a cross-sectional view of a gas turbine combustor according to one embodiment of the present invention operating in a modified mode of the fourth mode of FIG. 6D. FIG. 1 is an end view of a gas turbine combustor operating in a first mode according to one embodiment of the present invention. FIG. 2 is an end view of a gas turbine combustor according to one embodiment of the present invention operating in a second mode. FIG. FIG. 6 is an end view of a gas turbine combustor according to one embodiment of the present invention operating in a third mode. FIG. 6 is an end view of a gas turbine combustor according to one embodiment of the present invention operating in a fourth mode. 3 is a flow diagram illustrating a method for controlling a gas turbine according to an alternative embodiment of the present invention. 6 is a flow diagram illustrating a method for controlling a gas turbine according to yet another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION By reference, this application is incorporated by reference in US Pat. No. 6,935,116, US Pat. No. 6,986,254, US Pat. No. 7,137,256, US Pat. No. 7,237,384, US Pat. No. 7,308,793. , U.S. Pat. No. 7,513,115 and U.S. Pat. No. 7,767,025.

  The present invention discloses a method of operating a combustion system to improve the turndown capability of a gas turbine engine. That is, embodiments of the disclosed invention provide improved combustion stability in a gas turbine combustor when the demand for power from the generator is smaller and the required power from the engine is smaller. Provide the means.

  The present invention will now be described with respect to FIGS. One embodiment of a gas turbine combustor to which the improved method of operation of the present invention can be applied is shown in FIG. Combustion system 300 extends about a longitudinal axis AA and has a flow sleeve 302 for directing a predetermined amount of compressed air along the outer surface of combustion liner 304. The main fuel injector 306 is positioned radially outward of the combustion liner 304 and supplies fuel for mixing with compressed air along a portion of the outer surface of the combustion liner 304 before entering the combustion liner 304. Designed to be The fuel injected by the main fuel injector 306 is mixed with compressed air and travels forward toward the inlet region of the combustion liner 304 where the fuel / air mixture then reverses direction and enters the combustion liner 304. enter in. A pilot fuel nozzle 308 for providing and maintaining a pilot for the combustion system generally extends along the longitudinal axis AA. The flash is used to ignite, support and maintain multiple stages of the fuel injectors of combustion system 300.

  The combustion system 300 also has a premixer 310 that is stepped radially. The premixer 310 has an end cover 312 that includes a first fuel plenum 314 that extends about a longitudinal axis AA of the combustion system 300 and a first fuel plenum 314. And has a first fuel plenum 314 and a concentric second fuel plenum 316. The radially stepped premixer 310 also has a radial inflow swirler 318 that is at least partially perpendicular to the longitudinal axis AA of the combustion system 300. A plurality of vanes 320 oriented in different directions.

  The pilot fuel nozzle 308 is connected to a fuel supply (not shown) and provides fuel to the combustion system 300 to supply a pilot 350, which is generally in the longitudinal axis AA. Are positioned along. A radially stepped premixer 310 having fuel plenums 314 and 316, a radial inflow swirler 318, and a plurality of vanes 320 provides a fuel-air mixture and additional fuel to the pilot 350. Through a vane 320 for providing a pilot tune stage or P tune 352.

  As described above, the combustion system 300 also has a main fuel injector 306. In the embodiment of the present invention shown in FIG. 3, the main fuel injector 306 is disposed radially outward of the combustion liner 304 and extends in an annular arrangement around the combustion liner 304. The main fuel injector 306 may have one or more portions and stages that extend evenly or unevenly around the periphery of the main fuel stage. As one application for the described invention, the main fuel injector is divided into two stages, a first part and a second part. The first portion extends over about 120 degrees, while the second portion extends over approximately the remaining 240 degrees span. As shown in FIG. 4, the first portion of the main fuel injector 306 generates a main 1 flame 354, and the second portion of the main fuel injector 306 generates a main 2 flame 356.

  Referring to FIG. 4, a rear view of the inside of the gas turbine combustor of FIG. 3 as viewed from the front is shown. FIG. 4 clearly shows the respective radial and circumferential positions of the flame positions within the combustion system 300, with a pilot flame 350 in the center and a pilot tune stage 352 disposed radially outward of the pilot flame 350. And a main 1 flame 354 and a main 2 flame 356 arranged on the radially outer side of the pilot tune stage 352 are shown.

  As described above, a gas turbine engine has a plurality of combustors. In general, for discussion purposes, a gas turbine engine may have a low emission combustor as disclosed herein and may be disposed in a can-type annular configuration around the gas turbine engine. One type of gas turbine engine (eg, a heavy duty gas turbine engine) may typically be provided with 6-18 individual combustors, but is not limited to such a number. Each combustor is attached by the components outlined above. Thus, based on the type of gas turbine engine, there can be multiple different fuel circuits utilized to operate the gas turbine engine. In one form of the invention, four fuel circuits are used. However, it is contemplated that certain fuel circuits and associated control mechanisms can be modified to have fewer or additional fuel circuits.

  Having described the physical arrangement of the combustion system 300 in which the present invention operates, reference is now made to FIGS. 5-9 for a detailed description of the method of operation for the combustion system. The present invention utilizes four fuel stages for tuning and operational flexibility. More specifically, with reference to FIG. 5, a method 500 for operating the combustion system 300 of FIG. 3 is shown, in which four different methods are used to increase combustion stability to allow operation at lower load settings. Different fuel stages are used. First, at step 502, fuel is supplied to a pilot fuel nozzle of a gas turbine combustor. Next, in step 504, fuel from the pilot fuel nozzle is ignited to form a seed fire. This ignition can be caused by various ignition sources such as spark igniters or torch igniters. The pilot fuel nozzle is generally positioned along the longitudinal axis of the combustor, and the resulting fire is also generally positioned along the longitudinal axis. These steps of supplying fuel to the pilot fuel nozzle to ignite the fuel and igniting the fuel are considered as mode 1 of operation of the combustion system, and the operating range starting with ignition or "light off" of the pilot fuel nozzle And continue through “no full speed load” or “FSNL” conditions. FSNL, as described above, is the engine operating condition where the turbine and compressor are operating at the maximum design speed, which is about 3600 revolutions per minute for a 60 Hz engine. But the load is not applied by the generator. A description of Mode 1 operation of the combustion system is shown in FIGS. 6A and 7A.

  As those skilled in the art will appreciate, a flame inherently includes a shear layer. Generally speaking, a shear layer or boundary layer is a region of flow where a large velocity gradient may exist. The flame shear layer is a shared area between the outermost edge of the flame and the non-flammable surrounding or adjacent flame.

  Ignition of fuel from the main set of fuel injectors can occur more easily and reliably by being able to control the fuel / air ratio of the seed fire shear layer. More specifically, locally increasing the fuel supply at the outermost radial location in the premixing passage increases the concentration of fuel in the resulting seed fire shear layer. As a result, the concentrated shear layer allows the main injector to ignite more easily and reliably without requiring much energy, and as a result, pulsation during ignition of the main fuel injector. The level drops.

  An additional advantage of being able to locally concentrate the fuel flow to the shear layer is that a stable process of igniting the fuel injected by the main injector can be maintained. That is, in premixed combustion systems, fuel flow levels are conventionally kept as lean as possible to reduce emissions. By locally adding fuel to the shear layer during a selective time, a more fuel-rich mixture is formed, thereby increasing the fuel / air ratio in the shear layer region. A more fuel-rich mixture provides more favorable conditions for generating ignition and enhances flame stability. When the flame is ignited, the level of fuel concentration can be reduced to a leaner mixture without compromising flame stability.

  In step 506, fuel continues to be supplied to the pilot fuel nozzle while also being supplied to the set of pilot tune stage injectors as in step 502. Pilot tune stage injectors are located in the plurality of vanes 320 of the radial inflow swirler 318, located radially outward of the pilot fuel nozzle 308, from the end cover fuel plenum to mix with the ambient air flow. Inject fuel. This fuel-air mixture is then used to pass along the fire, enhance and assist the fire, and to concentrate the shear layer of the fire. The operation of the pilot fuel nozzle and the set of pilot tune stage injectors together is considered mode 2 of operation of the combustion system. Mode 2 can operate from light off to about 10% load. A description of the mode 2 operation of the combustion system is shown in FIGS. 6B and 7B, where the fuel / air mixture from the pilot tune stage surrounds the seed fire radially outward of the fire. Shown to be.

  Next, in step 508, the combustion system enters mode 3 of operation. In mode 3, fuel is supplied to the first portion of the main fuel injector while still being supplied to the pilot fuel nozzle and the set of pilot tune stage injectors. As described above, the main fuel injector 306 of the combustion system is arranged in an annular arrangement around the combustion liner, and includes two parts, a first part extending about 120 degrees around the combustion liner 304; It is divided into a second portion extending about 240 degrees around the combustion liner 304. In step 510, the fuel injected by the first portion of the main fuel injector in step 508 is ignited to form a main combustion flame. As a result of the pilot fire formed through modes 1 and 2, ignition of the main combustion flame occurs. However, to ignite this main combustion flame, the combustion system is usually raised to this point by adding fuel to the pilot tune stage at the transition to mode 3 (at the end of mode 2). The fuel added through the stage is then transferred to the first part of the main fuel injector. This ensures an efficient and quiet transition to mode 3. Starting at light off, fuel can be supplied to the first portion of the main injector through an approximately 10% load condition. A description of the mode 3 operation of the combustion system is shown in FIGS. 6C and 7C, where the main combustion flame formed in mode 3 is radially outward of the fuel-air mixture from the pilot tune stage of the injector. Is arranged.

  In step 512, the combustion system operates in mode 4, where fuel is supplied to the second portion of the main fuel injector and the first portion of the main fuel injector, the pilot fuel nozzle and the pilot of the injector. Also supplied to the tune stage. That is, in mode 4 of operation, fuel is flowing through all four circuits of the combustion system and is now flowing to all main fuel injectors. As a result, a 360 degree ring of fuel is injected radially outward of the combustion liner from the main fuel injector into the passing air stream. In step 514, the fuel injected by the second portion of the main fuel injector is ignited by a main combustion flame formed by the fuel injected from the first portion of the main fuel injector. This is mode 4 operation. Starting at light off, fuel can be injected through the second portion of the main fuel injector through an approximately 25% load condition. Fuel continues to flow through these circuits to conditions that are also referred to as approximately 100% load conditions or base load conditions. Operation in mode 4 provides a wide and stable operating range for the combustion system. A description of the mode 4 operation of the combustion system is shown in FIGS. 6D and 7D, where the main combustion flame is augmented by the fuel injection in mode 4 and extends circumferentially around the seed fire. Yes.

  When the combustion system reaches base load or 100% load conditions and fuel is flowing through all four circuits, the fuel flow to one or more of the circuits supplying fuel to the combustor core is reduced. Can be adjusted. This is a regulated flow to the conditioned pilot fuel nozzle stream 360 and / or pilot tune stage 362, as shown in FIG. 6E. When lower loads are required, it is desirable to reduce the amount of fuel. Conventionally, however, where the fuel flow level is reduced, the flame temperature tends to decrease, which results in a corresponding increase in CO emissions. For example, referring again to FIG. 5, in step 516, the fuel flow to the core injection region, which is a pilot fuel nozzle and / or a pilot tune stage injector, can be adjusted. However, as shown in FIG. 6E, maintaining the fuel flow to the first and second portions of the main fuel injector while regulating the fuel flow to the pilot tune stage of the pilot fuel nozzle and / or injector By this, the main combustion flame stays at a higher temperature than the seed fire in a complete ring. That is, the higher temperature main combustion flame consumes the CO generated by the lower temperature seed flame. This adjustment of mode 4 is shown in FIG. 6E and occurs during normal premixing operation of the combustion system.

  As those skilled in the art will appreciate, when the power required from the engine is reduced or turned down, it is desirable to effectively reduce engine power while still maintaining engine operation. When less engine power is required, less fuel is required in the combustion process. Therefore, in order to turn down the engine, the fuel flow must also be reduced. However, as described above, when the fuel flow level is reduced, the flame temperature tends to decrease, which correspondingly results in increased CO emissions. Therefore, this additional CO must be burned down sufficiently to keep the engine within emission regulations. One way to burn off CO emissions is to keep the main combustion flame generated by the first and second portions of the main fuel injector as hot as possible. This can be achieved by careful adjustment of the fuel flow to the fuel injector. More specifically, the fuel flow to the core region (pilot fuel nozzle and / or pilot tune stage injector) is reduced and the fuel flow to the first and second portions of the main stage injector is slightly increased. The The net overall effect is a lower total fuel flow to the combustor, but since the fuel flow to the pilot region is reduced or eliminated, a higher ratio of fuel than the pilot and / or pilot tune stage is the main Oriented to maintain the flame.

  The step of supplying the fuel flow and ignition of the injected fuel will continue to be described, but those skilled in the art will not be able to continue the fuel flow in order to maintain the flame resulting from the ignition of the just injected fuel. Nonetheless, you will understand that the resulting flame will disappear. That is, the fuel supply / injection step needs to occur before and simultaneously with fuel ignition.

  In an alternative embodiment of the present invention, the combustion system 300 includes a pilot fuel nozzle, a set of pilot tuned injectors, and two main to main 1 and main 2 flames forming a main combustion flame, as described above. It has four main fuel circuits for providing fuel to one circuit. However, improvements in combustion noise and emissions do not initially direct fuel to only the pilot fuel nozzle, but instead provide fuel to the pilot fuel nozzle and pilot tune stage injector set to achieve initial light-off. By doing so, it has been determined that it can be accomplished using current hardware.

  With reference to FIG. 8, an alternative process for operating a gas turbine combustor is disclosed in process 800. In step 802, fuel is first supplied to a pilot fuel nozzle and a set of pilot tune stage injectors in a gas turbine combustor. Next, at step 804, the fuel injected by the pilot fuel nozzle and pilot tune stage injector is ignited. When a flame is formed in the pilot zone, fuel supply to the pilot fuel nozzle and the stage of the pilot tune injector continues through a load condition of about 10%. Then, at step 806, fuel is supplied to the first portion of the set of main fuel injectors. As described above, the first portion of the main fuel injector set consists of an approximately 120 degree arcuate section of the fuel injector. Fuel continues to flow to the pilot fuel nozzle and pilot tune stage while fuel is being supplied to the first portion of the set of main fuel injectors. In step 808, the fuel injected by the first portion of the main fuel injector set ignites to form a main combustion flame. The fuel injected by the first part of the main fuel injector can start simultaneously with light-off through an approximately 10% load condition. Once the main fuel flame is formed, then in step 810, the main fuel injector set is maintained while continuing to supply fuel to the first portion of the main injector set, the pilot fuel nozzle, and the pilot tune stage injector. Fuel is supplied to the second portion. Starting at light-off and about 25% load conditions, fuel can be supplied to the second portion of the main fuel injector. Next, at step 812, the fuel injected by the second portion of the set of main fuel injectors is ignited to augment the main combustion flame. As in the other embodiments described above, in step 814, fuel flows to the pilot tune stage injector and the pilot fuel nozzle can then be adjusted to enhance flame stability.

  In yet another embodiment of the present invention, a method for operating a gas turbine combustor has been developed, as described above, where fuel is supplied to the three circuits but not to the pilot tune stage of the injector. Referring now to FIG. 9, a method 900 for operating a gas turbine combustor includes supplying fuel 902 to a pilot fuel nozzle of the gas turbine combustor. Next, in step 904, the fuel injected by the pilot fuel nozzle is ignited to form a seed fire. Then, in step 906, fuel is supplied to the first portion of the set of main fuel injectors while continuing to supply fuel to the pilot fuel nozzle. Starting at light-off and about 10% load conditions, fuel can be supplied to the first portion of the main fuel injector. Then, at step 908, fuel from the first portion of the main injector is ignited to form a main combustion flame.

  In step 910, fuel is supplied to the second portion of the set of main fuel injectors while also being supplied to the first portion of the main fuel injector and the pilot fuel nozzle. Starting between light-off and about 25% load conditions, fuel can be supplied to the second portion of the main injector. In one such embodiment of the present invention, the first portion of the main injector extends over about 120 degrees in the arcuate passage, while the second portion of the main injector is in the arcuate passage. It extends over about 240 degrees. In step 912, the fuel supplied to the combustor by the second portion of the main injector is ignited and functions to augment the main combustion flame. As mentioned above, fuel continues to flow through these various circuits to about 100% load. Depending on the operating conditions of the engine, the process can continue at step 914, where fuel flow to the pilot nozzle can be adjusted. As described above, this adjustment can include reducing the amount of fuel flow to the pilot fuel nozzles to assist in engine turndown while controlling CO emissions.

  As will be appreciated by one skilled in the art, the present invention may be embodied in particular as a method, system or computer program product. Accordingly, the embodiments may take the form of a hardware embodiment, a software embodiment or an embodiment combining software and hardware. In one embodiment, the invention takes the form of a computerized method, such as a computer program product comprising computer-usable instructions embodied in one or more computer-readable media.

  Computer-readable media includes both volatile and non-volatile media, removable and non-removable media and contemplates media that can be read by databases, switches, and various other network devices. Network switches, routers and related components are essentially conventional because they are the means to communicate with them. By way of example, and not limitation, computer-readable media includes computer storage media and communication media.

  Computer storage media or machine readable media includes media implemented in any method or technique for storing information. Examples of stored information are computer-usable instructions, data structures, program modules and other data representations. Computer storage media include RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD), holographic media or other optical disk storage, magnetic cassette, magnetic tape, magnetic Including but not limited to disk storage devices and other magnetic storage devices. These memory components can store data instantaneously, temporarily or permanently.

  Communication media typically stores computer-usable instructions, including data structures and program modules, in a coordinated data signal. A “conditioned data signal” refers to a propagated signal having one or more characteristics that are set or changed to encode information in the signal. A typical conditioned data signal includes a carrier wave or other transport mechanism. Communication media includes any information delivery media. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, infrared, wireless, microwave, spread spectrum and other wireless media technologies. Combinations of the above are included within the scope of computer-readable media.

  The computerized method may be a free-standing software program stored in its own piece of hard wafer that can be incorporated into the operating system of the gas turbine engine, or an existing method that governs the operating system of the gas turbine engine It can be a software program designed to be incorporated into software.

  Although the present invention has been described with respect to what are presently known as preferred embodiments, the invention is not limited to the disclosed embodiments, but instead is within the scope of the following claims. It is intended to encompass various modifications and equivalent sequences. The invention has been described with reference to particular embodiments that are illustrative rather than restrictive in all respects. Alternative embodiments and required operation, such as machining of shroud surfaces other than the hardened surface and wear caused by operation of the hardened surface, are within the technical scope of the present invention without departing from the scope of the invention. Will be apparent to those skilled in the art.

  From the foregoing description, it can be seen that the present invention is well adapted to accomplish all its objectives and challenges, with other advantages that are apparent and inherent to the system and method. It will be understood that certain features and subcombinations are available and may be used without reference to other features and subcombinations. This is considered by the claims and in the claims.

Claims (31)

In a method of operating a gas turbine combustor,
Supplying fuel to a pilot fuel nozzle of the gas turbine combustor;
Igniting the fuel injected by the pilot fuel nozzle;
Supplying fuel to a set of pilot tune stage injectors and a pilot fuel nozzle, the pilot tune stage injector being positioned radially outward of the pilot fuel nozzle;
Supplying fuel to a first portion of a set of main fuel injectors, the pilot fuel nozzle, and the pilot tune stage injector;
Igniting the fuel injected by the first part of the set of main fuel injectors to form a main combustion flame;
Supplying fuel to a second portion of the set of main fuel injectors, a first portion of the set of main fuel injectors, the pilot fuel nozzle, and a pilot tune stage injector;
A method of operating a gas turbine combustor, characterized by igniting fuel injected by a second portion of the set of main fuel injectors to augment the main combustion flame.   The method of claim 1, further comprising adjusting fuel to the pilot fuel nozzle and / or the pilot tune stage injector.   The method of claim 1, wherein during the gas turbine combustor light-off, fuel is supplied only to the pilot fuel nozzles up to full speed no load (FSNL) conditions.   4. The method of claim 3, wherein fuel is supplied to the pilot tune stage injector from light off to about 10% load condition.   5. The method of claim 4, wherein fuel is supplied to the first portion of the main fuel injector beginning at light off and up to about a 10% load condition.   6. The method of claim 5, wherein fuel is supplied to the second portion of the main fuel injector starting at light off and up to about 25% load condition.   The first portion of the set of main fuel injectors includes an arc segment of a fuel injector extending about 120 degrees, and the second portion of the set of main fuel injectors is an arc shape of the fuel injector extending about 240 degrees. The method of claim 1, comprising a segment. A computer implemented by a processing unit for staging fuel in a gas turbine combustor having a pilot fuel nozzle, a set of pilot tune stage injectors for tuning the pilot fuel nozzle, and a main set of fuel injectors In a simplified way,
Operating the combustor in a first mode in which fuel is injected by the pilot fuel nozzle;
Operating the combustor in a second mode in which fuel is injected by the pilot fuel nozzle and an injector for the pilot tune stage;
Operating the combustor in a third mode in which fuel is injected by the pilot fuel nozzle, an injector for the pilot tune stage, and a first portion of the main set of the fuel injector;
Fuel is injected by the pilot fuel nozzle, an injector for the pilot tune stage, a first portion of the main set of fuel injectors, and a second portion of the main set of fuel injectors A computerized method comprising operating the combustor in a mode.   The first portion of the main set of fuel injectors extends over an arcuate span of about 120 degrees, and the second portion of the main set of fuel injectors extends over an arcuate span of about 240 degrees. Item 9. The method according to Item 8.   The method of claim 8, wherein the first mode provides a starter to the gas turbine combustor.   The method of claim 10, wherein the fuel injected by the pilot tune stage provides an additional fuel source to condition and assist the pilot.   9. The method of claim 8, wherein the fuel injected by the third mode and the fourth mode is injected axially upstream, causing a direction reversal prior to ignition.   9. The method of claim 8, wherein fuel flow to the pilot fuel nozzle and the pilot tune stage injector is adjustable after operating the combustor in the fourth mode. In a method for improving the turndown capability of the gas turbine combustor while controlling carbon monoxide production from the gas turbine combustor,
Adjusting the fuel flow to the first and second portions of the annular array of main fuel injectors to assist the main combustion flame;
A method for improving the turndown capability of a gas turbine combustor, comprising adjusting fuel flow to one or more fuel injectors in a core section of the gas turbine combustor.   Adjusting the fuel flow to the first and second portions of the annular array of the main fuel injectors includes increasing fuel flow to the first and second portions. Item 15. The method according to Item 14.   The method of claim 15, wherein adjusting the fuel flow to one or more fuel injectors in the core section includes reducing at least the fuel flow to a pilot fuel nozzle.   The method of claim 16, wherein a ratio of fuel flow to the main fuel injector as compared to at least fuel flow to the pilot fuel nozzle increases while a total fuel flow to the engine decreases.   15. The first portion has an annular array of main fuel injectors extending about 120 degrees, and the second portion has an annular array of main fuel injectors extending about 240 degrees. Method.   The core section of the gas turbine combustor includes a pilot fuel nozzle and an injector of a pilot tune stage, the pilot tune stage of the fuel injector providing a fuel flow to assist a spark. 14. The method according to 14. In a method of operating a gas turbine combustor,
Supplying fuel to a pilot fuel nozzle and a set of pilot tune stage injectors of the gas turbine combustor;
Igniting the fuel injected by the pilot fuel nozzle and the pilot tune stage injector;
Supplying fuel to a first portion of a set of main fuel injectors, the pilot fuel nozzle, and the pilot tune stage injector;
Igniting the fuel injected by the first part of the set of main fuel injectors to form a main combustion flame;
Supplying fuel to a second portion of the set of main fuel injectors, a first portion of the set of main fuel injectors, the pilot fuel nozzle, and the pilot tune stage injector;
A method of operating a gas turbine combustor, characterized by igniting fuel injected by a second portion of the set of main fuel injectors to augment the main combustion flame.   21. The method of claim 20, further comprising adjusting fuel to the pilot fuel nozzle and / or the pilot tune stage injector to increase stability to the main combustion flame.   21. The method of claim 20, wherein only the pilot fuel nozzle and the pilot tune stage injector are fueled to about 10% load condition during gas turbine combustor light-off.   23. The method of claim 22, wherein fuel is supplied to the first portion of the main fuel injector beginning at light off to about 10% load condition.   24. The method of claim 23, wherein fuel is supplied to the second portion of the main fuel injector beginning at light off and up to about 25% load condition.   The first portion of the set of main fuel injectors includes an arcuate segment of the fuel injector that extends approximately 120 degrees, and the second portion of the set of main fuel injectors also includes a circle of fuel injectors that extends approximately 240 degrees. 21. The method of claim 20, comprising an arc segment. In a method of operating a gas turbine combustor,
Supplying fuel to a pilot fuel nozzle of the gas turbine combustor;
Igniting the fuel injected by the pilot fuel nozzle;
Supplying fuel to a first portion of a set of main fuel injectors and the pilot fuel nozzle;
Igniting the fuel injected by the first part of the set of main fuel injectors to form a main combustion flame;
Supplying fuel to a second portion of the set of main fuel injectors, a first portion of the set of main fuel injectors, and the pilot fuel nozzle;
A method of operating a gas turbine combustor, characterized by igniting fuel injected by a second portion of the set of main fuel injectors to augment the main combustion flame.   27. The method of claim 26, further comprising adjusting fuel to the pilot fuel nozzle.   27. The method of claim 26, wherein only the pilot fuel nozzle and the pilot tune stage injector are fueled up to about 10% load condition during gas turbine combustor light-off.   29. The method of claim 28, wherein fuel is supplied to the first portion of the main fuel injector beginning at light off to about 10% load condition.   30. The method of claim 29, wherein fuel is supplied to the second portion of the main fuel injector beginning at light off and up to about 25% load condition.   The first portion of the set of main fuel injectors includes an arcuate segment of the fuel injector that extends approximately 120 degrees, and the second portion of the set of main fuel injectors also includes a circle of fuel injectors that extends approximately 240 degrees. 27. The method of claim 26, comprising arcuate segments.

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