System and method for supplying a working fluid to a combustor

System and method for supplying working fluid to combustor

Technical field

[0001] The present invention generally relates to systems and methods for supplying working fluid to a combustor.

Background technique

[0002] Burners are generally used in industrial and power generation operations to ignite fuels to generate combustion gases with high temperatures and pressures. For example, gas turbines typically include one or more combustors to generate power or thrust. A typical gas turbine used for power generation includes an axial compressor at the front, one or more combustors around the middle, and a turbine at the rear. Ambient air may be supplied to the compressor, and the rotating blades and stationary guide vanes in the compressor gradually impart kinetic energy to the working fluid (air) to generate a compressed working fluid in a high-energy state. The compressed working fluid leaves the compressor and flows through one or more fuel nozzles into the combustion chambers in each combustor, where the compressed working fluid is mixed with fuel and ignited to generate combustion gas with high temperature and high pressure. The combustion gases are expanded in the turbine to perform work. For example, the expansion of the combustion gases in the turbine may rotate a shaft connected to a generator to generate electricity.

[0003] Various parameters affect the design and operation of the combustor. For example, higher combustion gas temperatures generally improve the thermodynamic efficiency of the burner. However, the higher combustion gas temperature also promotes flame stabilization conditions, in which the combustion flame migrates toward the fuel supplied by the fuel nozzles, which may cause damage to the fuel nozzles in a relatively short amount of time. In addition, higher combustion gas temperatures generally increase the dissociation rate of diatomic nitrogen, thereby increasing the production of nitrogen oxides (NO5^A). Conversely, the lower combustion gas temperature associated with reduced fuel flow and/or part load operation (weakening) generally reduces the chemical reaction rate of the combustion gas, thereby increasing the production of carbon monoxide and unburned hydrocarbons.

[0004] In a particular combustor design, one or more injectors, also called late lean injectors, may be circumferentially arranged around the combustion chamber downstream of the fuel nozzle. A portion of the compressed working fluid leaving the compressor may be diverted through the injector to mix with fuel to produce a lean fuel-air mixture. The lean fuel-air mixture can then be injected into the combustion chamber for additional combustion to increase the combustion gas temperature and increase the thermodynamic efficiency of the combustor.

[0005] Late lean injectors are effective in increasing combustion gas temperature without producing a corresponding increase in NOx products. However, the diverted compressed working fluid flowing through the injector necessarily reduces the amount and speed of compressed working fluid that is feasible to flow through the fuel nozzle. The reduced flow rate and/or velocity of the compressed working fluid passing through the fuel nozzle creates conditions that are more conducive to flame stability in the fuel nozzle. In addition, the reduced amount and speed of the compressed working fluid flowing through the fuel nozzle can affect the use of liquid fuel to operate the combustor without implementing additional NOx reduction measures (such as a richer fuel-air ratio and/or emulsification of liquid fuel). ability. Therefore, improved systems and methods that can vary the amount of working fluid diverted through the ejector would be useful.

Summary of the invention

[0006] The aspects and advantages of the present invention are set forth in the following description, or can be obvious from this description, or can be learned through the practice of the present invention.

[0007] One embodiment of the present invention is a system for supplying a working fluid to a combustor, which includes a fuel nozzle, a combustion chamber downstream of the fuel nozzle, and a flow sleeve circumferentially surrounding the combustion chamber. A plurality of injectors arranged circumferentially around the flow sleeve provide fluid communication through the flow sleeve and into the combustion chamber. The valve upstream of at least one of the plurality of injectors has a first position that allows working fluid to flow to the at least one injector and a second position that prevents the working fluid from flowing to the at least one injector.

[0008] Another embodiment of the present invention is a system for supplying a working fluid to a combustor, which includes a combustion chamber, a liner circumferentially surrounding the combustion chamber, and a flow sleeve circumferentially surrounding the liner. A plurality of injectors arranged circumferentially around the flow sleeve provide fluid communication through the flow sleeve and the liner and into the combustion chamber. The valve upstream of at least one of the plurality of injectors has a first position that allows working fluid to flow to the at least one injector and a second position that prevents the working fluid from flowing to the at least one injector.

[0009] The present invention may also include a method for supplying working fluid to the combustor. The method includes: flowing a working fluid from a compressor through a combustion chamber; diverting a portion of the working fluid through a plurality of injectors circumferentially arranged around the combustion chamber; and operating upstream of at least one of the plurality of injectors Valve to control the working fluid flowing through at least one ejector.

[0010] A system for supplying a working fluid to a combustor, comprising: a. a fuel nozzle; b. a combustion chamber downstream of the fuel nozzle; c. a flow sleeve circumferentially surrounding the combustion chamber; d. A plurality of injectors arranged radially around the flow sleeve, wherein the plurality of injectors provide fluid communication through the flow sleeve and into the combustion chamber; and e. a valve upstream of at least one of the plurality of injectors , Wherein the valve has a first position that allows working fluid to flow to the at least one ejector and a second position that prevents the working fluid from flowing to the at least one ejector.

[0011] Preferably, the system further includes a device for positioning the valve.

[0012] Preferably, the valve is biased in the first position.

[0013] Preferably, the system further includes a fluid reservoir in fluid communication with the valve outside the combustor.

[0014] Preferably, the system further comprises a first fluid connection between the fluid reservoir and the valve and a second fluid connection between the fluid reservoir and the inner side of the combustor.

[0015] Preferably, the system further includes a distribution manifold circumferentially surrounding the plurality of ejectors and a fluid passage through the distribution manifold, wherein the fluid passage provides fluid communication through the distribution manifold to the plurality of ejectors.

[0016] Preferably, the valve is upstream of the fluid passage through the distribution manifold.

[0017] Preferably, the system further includes a fuel passage in fluid communication with the injector in the flow sleeve.

[0018] A system for supplying a working fluid to a combustor, comprising: a. a combustion chamber; b. a liner circumferentially surrounding the combustion chamber; c. a flow sleeve circumferentially surrounding the liner; d. A plurality of injectors arranged circumferentially around the flow sleeve, wherein the plurality of injectors provide fluid communication into the combustion chamber through the flow sleeve and the liner; and e. at least one of the plurality of injectors The upstream valve, wherein the valve has a first position that allows working fluid to flow to at least one ejector and a second position that prevents working fluid to flow to at least one ejector.

[0019] Preferably, the system further includes a device for positioning the valve.

[0020] Preferably, the valve is biased in the first position.

[0021] Preferably, the system further includes a fluid reservoir in fluid communication with the valve outside the combustor.

[0022] Preferably, the system further comprises a first fluid connection between the fluid reservoir and the valve and a second fluid connection between the fluid reservoir and the inner side of the combustor.

[0023] Preferably, the system further includes a distribution manifold circumferentially surrounding the plurality of ejectors and a fluid passage through the distribution manifold, wherein the fluid passage provides fluid communication through the distribution manifold to the plurality of ejectors.

[0024] Preferably, the valve is upstream of the fluid passage through the distribution manifold.

[0025] Preferably, the system further includes a fuel passage in fluid communication with the injector in the flow sleeve. [0026] A method for supplying a working fluid to a combustor, comprising: a. allowing the working fluid to flow from the compressor through the combustion chamber; b. turning a part of the working fluid through the more circumferentially arranged around the combustion chamber Jets; and

c. Operate a valve upstream of at least one of the plurality of ejectors to control the working fluid flowing through the at least one ejector.

[0027] Preferably, the method further includes biasing the valve to increase the working fluid flowing through the at least one ejector.

[0028] Preferably, the method further includes supplying a control pressure from the outside of the combustor to the valve to operate the valve.

[0029] Preferably, the method further includes distributing the diverted portion of the working fluid to be substantially uniformly around the combustion chamber.

[0030] After reading the specification, those of ordinary skill in the art will better understand the features and aspects of such embodiments and others.

Description of the drawings

[0031] In the rest of the specification, including reference to the accompanying drawings, more specifically the disclosure of the present invention that is complete and achievable is described, including its best mode for those skilled in the art, in the accompanying drawings:

Figure 1 is a simplified side cross-sectional view of an exemplary gas turbine;

Fig. 2 is a simplified side perspective view of a part of the burner shown in Fig. 1 according to the first embodiment of the present invention

Figure;

Figure 3 is a side cross-sectional view of the injector shown in Figure 2 that supplies working fluid to the combustion chamber;

4 is a side cross-sectional view of the injector shown in FIG. 2 that prevents the working fluid from flowing to the combustion chamber; and FIG. 5 is a view of the combustor shown in FIG. 1 according to a second embodiment of the present invention A simplified side perspective view of a part.

[0032] Reference signs:

10 Gas turbine

12 compressor

14 burner

16 turbine

18 Rotor

20 generator

twenty two Working fluid

twenty four Static guide vane (compressor)

26 Rotating blade

28 Compressor housing

30 Compressor discharge pressure chamber (plenum)

32 Combustor housing 34 Fuel nozzle 36 End cover 38 Combustion chamber 40 Transition piece 42 Stator 44 Moving vane 46 Bushing 48 Flow sleeve 50 Annular passage 60 Injector 62 Fuel passage 64 Fuel port 70 Valve 72 Pressure chamber or pipeline 74 Fluid storage 76 First fluid connection 78 Second fluid connection 80 Third fluid connection 82 Isolation valve 84 Valve body 86 Chamber 88 Piston 90 Upper part of the chamber 92 Lower part of the chamber 94 Ventilation hole 96 Spring 98 Disk 100 Socket 110 Distribution manifold Tube 112 Annular pressure chamber 114 fluid passage.

Detailed ways

[0033] Reference will now be made in detail to the proposed embodiments of the present invention, one or more examples of which are shown in the accompanying drawings. The detailed description uses numbers and letters to refer to features in the drawings. The same or similar symbols have been used to refer to the same or similar parts of the present invention in the drawings and specification. As used herein, the terms "first,""second, and "third may be used interchangeably to distinguish one component from another, and are not intended to indicate the location or importance of individual components . In addition, the terms "upstream" and "downstream" refer to the relative positions of components in the fluid path. For example, if fluid flows from component A to component B, component A is upstream of component B. Conversely, if component B receives fluid flow from component A, component B is downstream of component A.

[0034] Each example is provided as an explanation of the present invention, not a limitation of the present invention. In fact, it will be obvious to those skilled in the art that modifications and variations can be made in the present invention without departing from its scope or spirit. For example, features shown or described as part of one embodiment can be used on another embodiment to yield yet another embodiment. Therefore, the present invention intends to cover such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0035] Various embodiments of the invention include systems and methods for supplying working fluid to a combustor. Typically, the system includes multiple late lean injectors circumferentially surrounding the combustion chamber. The system diverts or flows a portion of the working fluid through the late lean injector and into the combustion chamber. A valve upstream of one or more of the late lean injectors controls the amount of working fluid diverted through one or more of the late lean injectors. In certain embodiments, the distribution manifold may circumferentially surround the late lean injector to reduce changes in the pressure and/or flow rate of the working fluid reaching the late lean injector, and the valve may control the steering into the distribution manifold The amount of working fluid in. Therefore, the systems and methods disclosed herein enable the amount of working fluid diverted through the late lean injector to be changed as desired to support liquid fuel combustion and/or in response to flame stabilization conditions in the combustion chamber. Although for illustrative purposes, the exemplary embodiments of the present invention will be generally described in the context of being incorporated into a gas turbine, those of ordinary skill in the art will readily understand that the embodiments of the present invention can be applied to any combustor without Limited to gas turbine combustors, unless explicitly stated in the claims.

[0036] FIG. 1 provides a simplified cross-sectional view of an exemplary gas turbine 10 that may incorporate various embodiments of the present invention. As shown in the figure, the gas turbine 10 may include a compressor 12 at the front, one or more combustors 14 radially arranged around the middle, and a turbine 16 at the rear. The compressor 12 and turbine 16 typically share a common rotor 18 that is connected to a generator 20 to generate electricity.

[0037] The compressor 12 may be an axial compressor in which a working fluid 22 such as ambient air enters the compressor 12 and travels through alternating stages of stationary guide vanes 24 and rotating vanes 26. The compressor housing 28 contains the working fluid 22, and the stationary guide vanes 24 and the rotating blades 26 accelerate and redirect the working fluid 22 to produce a continuous flow of compressed working fluid 22. Most of the compressed working fluid 22 flows to the combustor 14 through the compressor discharge pressure chamber 30.

[0038] The combustor 14 may be any type of combustor known in the art. For example, as shown in FIG. 1, the combustor housing 32 may circumferentially surround some or all of the combustor 14 to contain the compressed working fluid 22 flowing from the compressor 12. One or more fuel nozzles 34 may be radially arranged in the end cover 36 to supply fuel to the combustion chamber 38 downstream of the fuel nozzles 34. Possible fuels include, for example, one or more of blast furnace gas, coke oven gas, natural gas, vaporized liquefied natural gas (LNG), hydrogen, and propane. The compressed working fluid 22 may flow from the compressor discharge pressure chamber 30 along the outside of the combustion chamber 38 before reaching the end cover 36 and reversing the direction to flow through the fuel nozzle 34 to mix with the fuel. The mixture of fuel and compressed working fluid 22 flows into the combustion chamber 38, where it is ignited to generate combustion gases having high temperature and high pressure. The combustion gases flow through the transition piece 40 to the turbine 16.

[0039] Turbine 16 may include alternating stages of stator 42 and rotating buckets 44. The first stage of the stator 42 redirects and concentrates the combustion gas on the first stage of the rotating bucket 44. When the combustion gas passes through the first stage of the rotating bucket 44, the combustion gas expands, thereby causing the rotating bucket 44 and the rotor 18 to rotate. The combustion gas then flows to the next stage of the stator 42, which redirects the combustion gas to the next stage of the rotating bucket 44, and the process is repeated for the next stage.

[0040] FIG. 2 provides a simplified perspective view of a portion of the combustor 14 shown in FIG. 1. As shown, the combustor 14 may include a liner 46 that circumferentially surrounds at least a portion of the combustion chamber 38. The flow sleeve 48 may circumferentially surround at least a portion of the bushing 46 to define an annular passage 50 surrounding the bushing 46. In this way, the compressed working fluid 22 from the compressor discharge chamber 30 can flow through the annular passage 50 along the outside of the liner 46 to flow through the fuel nozzle 34 in the reverse direction (shown in FIG. 1) And before entering the combustion chamber 38, convective cooling of the liner 46 is provided.

[0041] The combustor 14 may also include a plurality of pipes or injectors 60 that may provide late lean injection of fuel and working fluid 22 into the combustion chamber 38. The injector 60 may be circumferentially arranged around the combustion chamber 38, the liner 46, and the flow sleeve 48 downstream of the fuel nozzle 34 to provide fluid communication for at least a portion of the working fluid 22 to flow through the flow sleeve 48 and the liner 46 And enter the combustion chamber 38. As shown in FIG. 2, the flow sleeve 48 may include an internal fuel passage 62, and each injector 60 may include one or more fuel ports 64 circumferentially arranged around the injector 60. The internal fuel passage 62 may supply the same or different fuel to the fuel port 64 as the fuel supplied to the fuel nozzle 34. The fuel port 64 may therefore provide fluid communication for the flow of fuel into the injector 60 to allow fuel and working fluid 22 to mix as they flow through the injector 60 and into the combustion chamber 38. In this way, the injector 60 may supply a lean mixture of fuel and working fluid 22 for additional combustion to increase the temperature and therefore efficiency of the combustor 14.

[0042] One or more of the ejectors 60 may include a valve 70 upstream of the ejector 60 to allow, prevent, and/or throttle the amount of working fluid 22 that may flow through the ejector 60. The valve 70 may be any type of valve known to those of ordinary skill in the art for allowing, preventing, and/or throttling fluid flow. For example, the valve 70 may be a ball valve, a butterfly valve, a gate valve, a throttle valve, or other suitable types of valves. As shown in FIG. 2, a device for positioning the valve 70 may be operably connected to each valve 70. The structure for the positioning valve 70 may include any hydraulic, pneumatic or mechanical linkage device for positioning valves known to those of ordinary skill in the art. For example, a gear assembly may be connected to each valve 70 through the combustor housing 32 to allow manual or automatic operation of each valve 70. Alternatively, as shown in the specific embodiment shown in FIG. 2, the means for positioning the valve 70 may include a fluid pressure chamber or pipe 72 that is operably connected to each valve 70 to supply fluid pressure to the valve. 70. In this way, the fluid pressure supplied by the pipe 72 can create a pressure difference across a portion of the valve 70 to reposition the valve 70 between the first position and the second position, the first position allowing the working fluid 22 to flow to the ejector 60. The second position prevents the working fluid 22 from flowing to the ejector 60.

[0043] A pressure chamber or duct 72 may circumferentially surround the flow sleeve 48 to connect to the valves 70 circumferentially arranged around the flow sleeve 48 before traveling through the combustor housing 32. Once located outside the combustor housing 32, the pressure chamber or duct 72 can receive fluid pressure from any one of several possible sources. For example, as shown in FIG. 2, the pressure chamber or pipe 72 may be connected to a fluid reservoir 74 outside the combustor 14. The first fluid connection 76 between the fluid reservoir 74 and the valve 70 may provide fluid communication between the fluid reservoir 74 and the valve 70. The second fluid connection 78 between the fluid reservoir 74 and the compressor discharge pressure chamber 30 may provide fluid communication between the fluid reservoir 74 and the inside of the combustor 14. In this way, the compressed working fluid 22 flowing through the compressor discharge pressure chamber 30 can supply fluid pressure to the fluid reservoir 74 and then to the pressure chamber or pipe 72 to operate the valve 70, thereby reducing undesirable external materials. Or the probability of the fluid being introduced into the compressor discharge chamber 30 and/or the combustion chamber 38. As further shown in FIG. 2, the third fluid connection 80 to the fluid reservoir 74 may provide an additional source of fluid pressure to the fluid reservoir 74. In any case, the isolation valve 82 associated with each fluid connection may allow the desired fluid pressure to be applied to each valve 70 through the pressure chamber or pipe 72.

[0044] FIGS. 3 and 4 provide side cross-sectional views of the injector 60 shown in FIG. 2 in the first and second positions, respectively. As shown in FIGS. 3 and 4, the valve 70 may be attached or connected to the ejector 60 to alternately allow or prevent fluid flow into the ejector 60. In the specific embodiment shown in FIGS. 3 and 4, the valve 70 includes a valve body 84 defining a chamber 86 and a piston 88 within the chamber 86 that divides the chamber 86 into an upper portion 90 and a lower portion 92. The upper portion 90 of the chamber 86 includes a vent 94 to allow the fluid pressure of the compressor discharge chamber 30 to be applied to the top of the piston 88. A pressure chamber or pipe 72 is connected to the lower portion 92 of the chamber 86 to allow fluid pressure from the fluid reservoir 74 to be applied to the bottom of the piston 88. The pressure difference between the top and bottom of the piston 88 therefore provides a measure for positioning the valve 70 between the first and second positions. In addition, the valve 70 may also include a spring 96 or other means known to those of ordinary skill in the art for biasing the valve 70 in the first or second position.

[0045] As shown in FIG. 3, when the fluid pressure in the duct 72 and the force applied by the spring 96 exceed the fluid pressure applied through the vent hole 94, the piston 88 moves upward. The disk 98 connected to the piston 88 then moves upward away from the seat 100 formed by the valve body 84 and/or the injector 60. In this first position, the working fluid 22 from the compressor discharge pressure chamber 30 can flow into and through the injector 60 and into the combustion chamber 38. The working fluid 22 flowing through the ejector 60 may provide dilution and/or quenching to the combustion gases generated in the combustion chamber 38 and flowing through the transition piece 40 to the turbine 16. In addition, the fuel supplied into the injector 60 through the fuel passage 62 and the fuel port 64 may be mixed with the working fluid 22 for additional combustion before being injected into the combustion chamber 38 to increase the combustion gas temperature and increase the burner 14 The thermodynamic efficiency.

[0046] In FIG. 4, the fluid pressure in the duct 72 and the force applied by the spring 96 are less than the fluid pressure applied through the vent hole 94, causing the piston 88 to move downward. Therefore, the disk 98 connected to the piston 88 moves downward and engages with the socket 100 formed by the valve body 84 and/or the injector 60. In this second position, the working fluid 22 from the compressor discharge chamber 30 bypasses the injector 60 and flows toward the end cover 36 and the fuel valve 34. The additional working fluid 22 flowing through the fuel valve 34 may provide additional margin to prevent flame stabilization and/or provide additional mixing and dilution of liquid fuel combustion. According to the teachings herein, those skilled in the art can easily understand that the valve 70 shown in FIGS. 2 to 4 can be between the first position shown in FIG. 3 and the second position shown in FIG. 4 Operate consistently or independently at any position of the Therefore, the valve 70 may be positioned to achieve a desired fuel-air ratio through each injector 60 to provide the best emission performance at all operating levels of the combustor 14.

[0047] FIG. 5 provides a simplified side perspective view of a portion of the combustor 14 shown in FIG. 1 according to a second embodiment of the invention. The combustor 14 also includes a liner 46, a sleeve 48, an annular passage 50, an injector 60, a fuel passage 62, and a fuel port 64 as previously described with respect to the embodiment shown in FIGS. 2 to 4. In addition, the distribution manifold 110 circumferentially surrounds the ejector 60 to protect the ejector 60 from the direct impact of the compressed working fluid 22 flowing out of the compressor 12. The distribution manifold 110 may be press-fitted or otherwise connected to the circumference of the combustor housing 32 and/or flow sleeve 48 to provide a substantially closed volume or ring shape between the distribution manifold 110 and the flow sleeve 48Pressure chamber112. Pressure room 112. The distribution manifold 110 may extend axially along a portion or the entire length of the flow sleeve 48. In the particular embodiment shown in FIG. 5, for example, the distribution manifold 110 extends axially along the entire length of the flow sleeve 48 such that the distribution manifold 110 and the flow sleeve 48 are substantially coextensive.

[ 0048] One or more fluid passages 114 through the distribution manifold 110 may provide fluid communication through the distribution manifold 110 to the annular pressure chamber 112 between the distribution manifold 110 and the flow sleeve 48. A portion of the compressed working fluid 22 may thus be diverted or flow through the fluid passage 114 and into the annular pressure chamber 112. Since the compressed working fluid 22 flows around the flow sleeve 48 in the annular pressure chamber 112, the change in the pressure and/or flow rate of the working fluid 22 reaching the ejector 60 is reduced, resulting in more injection into the combustion chamber 38. Homogeneous fuel-air mixture.

[0049] The embodiment shown in FIG. 5 may also include a valve 70 and a device for positioning the valve 70, as described above with respect to FIGS. 2 to 4. Valve 70 may be attached or connected upstream of fluid passage 114 in distribution manifold 110 to allow, prevent, and/or throttle the amount of working fluid 22 that may flow through fluid passage 114, annular pressure chamber 112, and ejector 60. In this way, a single valve 70 can control the working fluid 22 flowing through multiple ejectors 60 surrounded by the distribution manifold 110. In addition, a single valve 70 can reduce the amount of pipes 72 or other devices required to locate multiple valves 70 circumferentially arranged around the flow sleeve 48.

[0050] The system shown and described in relation to FIGS. 1 to 5 may also provide a method for supplying the working fluid 22 to the combustor 14. The method may include: flowing the working fluid 22 from the compressor 12 through the combustion chamber 38; turning or flowing a portion of the working fluid 22 through one or more injectors 60 circumferentially arranged around the combustion chamber 38; and operating at The valve 70 upstream of the ejector controls the working fluid 22 flowing through the ejector 60. In certain embodiments, the method may further include biasing the valve 70 to a certain position and/or supplying control pressure from the outside of the combustor 14 to the valve 70 to operate the valve 70. Alternatively or in addition, the method may include distributing the diverted portion of the working fluid 22 to be substantially uniform around the combustion chamber 38. [0051] Various embodiments of the present invention may provide one or more technical advantages over existing late lean injection systems. For example, the systems and methods described herein may be used to adjust the amount of working fluid 22 diverted through the injector 60 during liquid fuel operation and/or reduce flame stabilization conditions near the fuel nozzle 34. In addition, the embodiments described herein can be used to fine-tune the working fluid 22 flowing through the ejectors 60 to reduce the pressure and pressure of the working fluid 22 passing through the ejectors 60.

/ Or changes in flow.

[0052] This written description uses examples to disclose the invention, including the best mode, and also enables any person skilled in the art to practice the invention, including preparing and using any device or system and performing any combined method. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. If such other examples include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not substantially differ from the literal language of the claims, such other examples are expected to be within the scope of the claims.