Low emission vortex fuel nozzle

Abstract

A fuel nozzle and a method of operating the fuel nozzle may include a set of chambers in the fuel nozzle, wherein the chambers may include an inner mixing chamber and an outer mixing chamber. The inner and outer mixing chambers may each receive air and fuel, respectively, and combine the air and fuel to form a mixture of air and fuel. The first hole pattern and the second hole pattern may be configured in the fuel nozzle, wherein fuel enters the inner mixing chamber through the first hole pattern and enters the outer mixing chamber through the second hole pattern. Further, an angled discharge port may be included with the inner mixing chamber, where the angled discharge port slows the exit velocity of the mixture of air and fuel prior to exiting the fuel nozzle through the discharge end of the fuel nozzle. The set of chambers, together with the first and second pattern of holes and the angled vent, can promote flame stabilization at two different points downstream of the fuel nozzle, depending on the flow rate of fuel and air.

Description

Technical Field

[0001] Embodiments generally relate to industrial burner technology. Embodiments also relate to low emission burners used in industrial applications. Embodiments also relate to fuel nozzles utilized in the burners. Background Art

[0002] Some industrial single burner applications require significant amounts of thermal turndown to provide the desired operating performance (e.g., air heating, thermal oxidizers, etc.). Thermal turndown in single burner industrial processes is often limited by the burner. Conventional industrial burners in these applications can operate at a thermal turndown of, for example, 50:1 (e.g., maximum capacity to minimum capacity). This degree of turndown allows these processes to operate flexibly in terms of production volume and operating conditions. However, low emission industrial burners are often unable to meet this degree of thermal turndown. The emission reduction technologies used by these burners often limit their window of stable fuel and air ratios, as well as their thermal turndown.

[0003] As limits on NOx and CO emissions increase, low emission burners become more and more prominent. Users and customers often have no choice but to accept a reduction in thermal turndown to meet emission requirements. If industrial burners could be designed in a way that maintains the highest possible flexibility while still producing ultra-low NOx and CO emissions, this would achieve significant advantages over conventional approaches. Summary of the invention

[0004] The following summary of the invention is provided to facilitate understanding of some features of the embodiments disclosed in the present invention, and is not intended to be a complete description. A comprehensive understanding of the various aspects of the embodiments disclosed herein can be obtained by taking the specification, claims, drawings and abstract as a whole.

[0005]

[0011] Accordingly, one aspect of an embodiment is to provide improved burner technology that can be used in industrial and other applications.

[0006] Another aspect of the embodiments is to provide an improved low emission burner.

[0007] Yet another aspect of the embodiments is to provide an improved fuel nozzle for a combustor.

[0008] It is yet another aspect of the embodiments to provide a low emissions swirl fuel nozzle.

[0009] Another aspect of the embodiments is to provide a method of operating a low emissions swirl fuel nozzle.

[0010] The above aspects and other objectives can now be achieved as described herein. In one embodiment, a fuel nozzle may include: a plurality of chambers located in the fuel nozzle, wherein the plurality of chambers include an inner mixing chamber and an outer mixing chamber, wherein the inner mixing chamber and the outer mixing chamber each receive air and fuel, respectively, and combine the air and fuel to form an air and fuel mixture; a first hole pattern and a second hole pattern formed in the fuel nozzle, wherein the fuel enters the inner mixing chamber through the first hole pattern and enters the outer mixing chamber through the second hole pattern; an angled discharge port included with the inner mixing chamber, wherein the angled discharge port slows the exit velocity of the air and fuel mixture before it exits the fuel nozzle through a discharge end of the fuel nozzle, wherein the plurality of chambers together with the first hole pattern and the second hole pattern and the angled discharge port promote flame stabilization at two different points downstream of the fuel nozzle, depending on the flow rate of the fuel and air.

[0011] In one embodiment, the outer mixing chamber may include a combination of spaces created between a plurality of vanes and an air housing.

[0012] In one embodiment, a plurality of vanes may be positioned at an angle to the long axis of the combustor to create a swirling flow at the discharge end of the fuel nozzle.

[0013] In one embodiment, a plurality of vanes may be positioned at an angle to the long axis of the combustor to create a swirling flow at the discharge end of the nozzle.

[0014] In one embodiment, fuel may enter the fuel nozzle through a fuel inlet and proceed to the inner mixing chamber where the fuel is distributed to both the inner and outer mixing chambers.

[0015] In one embodiment, fuel enters the inner mixing chamber through a first hole pattern at a desired amount and velocity.

[0016] In one embodiment, fuel may enter the outer mixing chamber through the second hole pattern at a desired amount and velocity.

[0017] In one embodiment, the vortex is stabilized downstream of the fuel nozzle.

[0018] In one embodiment, as fuel capacity decreases, the flame undergoes a stability transition immediately downstream of the discharge end of the fuel nozzle.

[0019] In one embodiment, a fuel nozzle may include: a plurality of chambers located in the fuel nozzle, wherein the plurality of chambers include an inner mixing chamber and an outer mixing chamber, wherein the inner mixing chamber and the outer mixing chamber each receive air and fuel, respectively, and combine the air and fuel to form an air and fuel mixture; and an angled discharge port included with the inner mixing chamber, wherein the angled discharge port slows down the exit velocity of the air and fuel mixture before it exits the fuel nozzle through a discharge end of the fuel nozzle, wherein the plurality of chambers and the angled discharge port promote flame stabilization at two different points downstream of the fuel nozzle, depending on the flow rate of the fuel and air.

[0020] In one embodiment, a first hole pattern and a second hole pattern may be configured by a fuel nozzle, wherein fuel enters an inner mixing chamber through the first hole pattern and enters an outer mixing chamber through the second hole pattern.

[0021] In one embodiment, a method of operating a fuel nozzle may involve the following steps or operations: receiving air and fuel in an inner mixing chamber and an outer mixing chamber, respectively, among a plurality of chambers located in the fuel nozzle; combining the air and the fuel to form a mixture of air and fuel, wherein the fuel enters the inner mixing chamber through a first hole pattern formed in the fuel nozzle and enters the outer mixing chamber through a second hole pattern formed in the fuel nozzle; and utilizing an angled discharge port included with the inner mixing chamber to slow down the exit velocity of the mixture of air and fuel before it exits the fuel nozzle through a discharge end of the fuel nozzle.

[0022] In one embodiment of the method, multiple chambers along with first and second hole patterns and angled discharge ports may facilitate flame stabilization at two different points downstream of the fuel nozzle, depending on the flow rates of fuel and air.

[0023] In one embodiment of the method, the outer mixing chamber may include a combination of spaces created between the plurality of vanes and the air housing.

[0024] In one embodiment of the method, a plurality of vanes may be positioned at an angle to the long axis of the combustor to produce a swirling flow at the discharge end of the fuel nozzle.

[0025] An embodiment of the method may also involve generating a swirling flow at a discharge end of the nozzle, wherein a plurality of vanes are positioned at an angle to a long axis of the combustor.

[0026] In one embodiment of the method, fuel may enter the fuel nozzle through a fuel inlet and may proceed to the inner mixing chamber where the fuel is distributed to both the inner and outer mixing chambers.

[0027] In one embodiment of the method, fuel may enter the inner mixing chamber through the first hole pattern in a desired amount and velocity.

[0028] In one embodiment of the method, fuel may enter the outer mixing chamber through the second hole pattern in a desired amount and velocity.

[0029] In one embodiment of the method, the flame may be swirl stabilized downstream of the fuel nozzle and further, as fuel capacity decreases, the flame may undergo a stabilization transition immediately downstream of the discharge end of the fuel nozzle. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings also illustrate the present embodiment and together with the detailed description serve to explain the principles of the embodiment, wherein like reference numerals refer to identical or functionally similar elements throughout the several views and are incorporated into and form a part of the specification.

[0031] Figure 1 A cross-sectional view showing an air housing and a fuel nozzle located therein that may be implemented according to one embodiment;

[0032] Figure 2 A cross-sectional view of only a fuel nozzle is shown according to one embodiment.

[0033] Figure 3 According to one embodiment, Figure 1 and Figure 2 A perspective view of a fuel nozzle shown in ;

[0034] Figure 4 shows a side view of an air casing relative to a flame according to one embodiment; and

[0035] Figure 5 A flow chart depicting the operation of a method of operating a fuel nozzle according to one embodiment is shown.

[0036] In the drawings described herein and shown, the same or similar parts and elements are generally indicated by the same reference numerals. DETAILED DESCRIPTION

[0037] The specific values ​​and configurations discussed in these non-limiting examples may vary, and are cited merely to illustrate one or more embodiments, and are not intended to limit the scope thereof.

[0038] The subject matter will now be described more fully below with reference to the accompanying drawings, which form a part of the subject matter and show specific exemplary embodiments by way of example. However, the subject matter can be embodied in a variety of different forms, and therefore the subject matter covered or claimed is intended to be construed as not limited to any exemplary embodiment listed herein; the exemplary embodiments are provided for illustration only. Likewise, the subject matter intended to be claimed or covered has an appropriately broad scope. Among other things, the subject matter may be embodied as a method, device, component, or system. Thus, the embodiments may, for example, take the form of hardware, software, firmware, or a combination thereof. Therefore, the following specific embodiments are not intended to be construed as having a limiting meaning.

[0039] Throughout the specification and claims, in addition to the meanings explicitly stated, terms may have slightly different meanings suggested or implied by the context. Likewise, phrases such as "in one embodiment" or "in an exemplary embodiment" and variations thereof as used herein may not necessarily refer to the same embodiment, and phrases "in another embodiment" or "in another exemplary embodiment" and variations thereof as used herein may or may not necessarily refer to different embodiments. For example, the claimed subject matter is intended to include, in whole or in part, a combination of the exemplary embodiments.

[0040] Generally speaking, terms may be understood at least in part from usage in context. For example, terms such as "and", "or" or "and / or" as used herein may include multiple meanings that may depend at least in part on the context in which such terms are used. Generally speaking, "or", if used in an association list, such as A, B or C, is intended to represent A, B and C used in an inclusive sense here, and A, B or C used in an exclusive sense here. In addition, the term "one or more" as used herein depends at least in part on the context and may be used to describe any feature, structure or characteristic in a singular sense, or may be used to describe a combination of features, structures or characteristics in a plural sense. Similarly, terms such as "one", "a kind of" or "the" also depend at least in part on the context and may be understood to convey singular usage or express plural usage. In addition, the term "based on" may be understood to not necessarily be intended to convey a set of exclusive factors, but may depend at least in part on the context, allowing for the presence of additional factors that are not necessarily explicitly described again.

[0041] The disclosed embodiments relate to a fuel nozzle design characterized by several key components, including the use of multiple chambers and hole patterns. That is, the fuel nozzle may include various chambers, including an inner mixing chamber and an outer mixing chamber. These chambers may receive air and fuel, respectively, and combine them to form a mixture of air and fuel. The fuel nozzle may be configured to include at least two different hole patterns: a first hole pattern may allow fuel to enter the inner mixing chamber, while a second hole pattern may direct fuel into the outer mixing chamber.

[0042] As will be discussed in more detail, another key component of the fuel nozzle includes the use of an angled discharge port. That is, inside the inner mixing chamber, an angled discharge mechanism can be implemented. This component can be used to reduce the exit velocity of the air-fuel mixture just before it leaves the fuel nozzle through its discharge end. This velocity reduction can help stabilize the flame downstream of the nozzle. Depending on the rate of fuel and air flow, the flame can stabilize at two different points downstream of the nozzle.

[0043] The fuel nozzle may also be used in conjunction with an external mixing chamber design. The external mixing chamber may be formed by an arrangement of blades and an air housing. The blades may be at an angle to the long axis of the burner to induce a swirling flow at the discharge end of the nozzle. The fuel nozzle may also enable swirl flow generation. In addition to the external mixing chamber design, multiple blades are placed at an angle to the long axis of the burner to generate a swirling flow at the discharge end of the nozzle.

[0044] Other components of the fuel nozzle may include a unique fuel entry feature, where fuel may enter the fuel nozzle through a fuel inlet. The fuel may then be distributed to both the inner mixing chamber and the outer mixing chamber simultaneously. The fuel entering the inner mixing chamber may do so in a specific amount and at a specific velocity through a first hole pattern, while the fuel entering the outer mixing chamber may follow a similar controlled pattern through a second hole pattern.

[0045] The disclosed fuel nozzle design can help stabilize the flame vortex downstream of the nozzle, which can improve combustion efficiency and control. Interestingly, as fuel capacity may decrease, the flame can shift its stability point immediately downstream of the discharge end of the fuel nozzle. Thus, the disclosed embodiments relate to an improved fuel nozzle with carefully designed components and designs that can optimize the mixing of air and fuel, control combustion, and stabilize the flame under various operating conditions.

[0046] Figure 1 A cross-sectional view of an air housing 3 and a fuel nozzle 6 located therein is shown as can be realized according to one embodiment. Figure 1 The fuel nozzle 6 shown in FIG. 1 is depicted as being enclosed within or by the air housing 3 such that air can pass through the inner chamber 10 and the outer chamber 14 . A stabilization point 15 is shown on the right hand side of the air housing 3 . Figure 1 Also depicted is a fuel inlet 4 through which fuel may enter. The fuel nozzle 6 may be used as a low emissions swirl fuel nozzle.

[0047] Figure 2 A cross-sectional view of only the fuel nozzle 6 is shown according to one embodiment. Figure 2As shown, the fuel can enter the inner chamber 10 through the hole pattern 8 in a desired amount and speed. In addition, the fuel can enter the outer chamber 14 through the hole pattern 7 in a desired amount and speed. Figure 2 Also depicted is the discharge end 12 shown on the right side of the figure. Figure 2 A common fuel chamber 9 for hole pattern 8 and hole pattern 7 is depicted.

[0048] Figure 3 According to one embodiment, Figure 1 and Figure 2 A perspective view of a fuel nozzle 6 is shown in FIG. A hole pattern 8 is shown on the left side of the figure. The fuel nozzle 6 may include one or more vanes, such as Figure 3 The blade 13 is shown.

[0049] Figure 4 A side view of the air housing 3 relative to the flame is shown according to one embodiment. Generally, the fuel nozzle 6 can be enclosed in the air housing 3 so that the air 1 passes through the inner chamber 10 and the outer chamber 14. The inner chamber 10 has an angled discharge port 11 that reduces the exit velocity of the air and fuel mixture before leaving the fuel nozzle through the discharge end 12. The outer chamber 14 is a combination of the space formed between the blades 13 and the air housing 3. These blades can be set at a specific angle to the long axis of the combustor to produce a swirling flow at the discharge end 12 of the fuel nozzle. The fuel 2 enters through the fuel inlet 4 and continues to the inner fuel chamber 9, where the fuel is distributed to the two chambers 10 and 14 at the same time.

[0050] Fuel may enter the inner chamber 10 through the hole pattern 8 at a desired amount and velocity. Fuel may enter the outer chamber 14 through the hole pattern 7 at a desired amount and velocity. At rated capacity, the flame swirls and stabilizes downstream of the nozzle 5. As the volume decreases, the flame transitions 15 to stabilize immediately downstream of the nozzle discharge end 12. The stabilization point 15 may be similar to other nozzle-mixed burners in that the flame may be anchored just downstream of the fuel nozzle and will not stabilize behind the fuel nozzle, thereby damaging the fuel nozzle.

[0051] Embodiments relate to a unique fuel nozzle that can provide ultra-low NOx and CO emissions while still maintaining flexibility in fuel and air ratios and thermal turndown. This can be achieved by implementing a multi-chamber design that forms two flame fronts that can alternately dominate depending on the burning rate (or volume). At higher burning rates, the air flow rate of the outer chamber is sufficient to form a vortex-stabilized flame. At lower burning rates, the flame front can move immediately downstream of the nozzle face and can be stabilized primarily by flow from the inner chamber. Each chamber can be designed so that the fuel and air ratios in these chambers cannot stabilize the flame alone.

[0052] The flame can only be stable when the outlet combination of the two chambers is flame stable. This situation may result in very stable combustion, similar to a nozzle mixing burner, in which the flame cannot flash back into the interior of the burner and cause damage. Multi-chamber designs can combine stability and flexibility with low emissions. Note that some conventional technologies may adopt multi-chamber fuel nozzle designs, which can also improve thermal downregulation by providing secondary flame stabilization points. However, in these types of devices, the flame only moves to the first chamber at low fuel flow rates and high air flow rates. The embodiments disclosed herein are different from these types of devices in terms of shape and flame stability technology. That is, in these conventional devices, vortex flow is not induced, and the flame is surrounded by perforations of air flow at low fuel flow rates and high air flow rates. When compared with the flame dynamics of the disclosed embodiments, the geometric structure differences produce completely different flame dynamics.

[0053] Some conventional devices may also include swirler geometry that utilizes inner and outer rings, swirl vanes, and flow balancing inserts in the inner ring to create a swirl-stabilized flame. These types of devices may include parameters responsible for creating a "diffuse flow" or swirl-stabilized flame. However, these devices are only swirlers, and no Fuel nozzles, such as fuel nozzle 6. Conventional devices of these types are designed to receive a premixed flow of fuel and air.

[0054] On the other hand, the embodiment can realize the flame of vortex stabilization using the fuel nozzle 6, which receives the air flow and injects the fuel into the air flow in a predetermined mode, speed and ratio. The swirler used in the conventional device receives the premix of fuel and air, and forms the vortex flow by mechanical means. By controlling the way of injecting the fuel into the air flow, the distribution pattern of the fuel, and by introducing a multi-chamber design, the total proportion of the fuel in each chamber is controlled to produce the above-mentioned effect (that is, to achieve low emissions with high heat reduction), these embodiments are further different from these conventional technologies.

[0055] The implementation of the fuel nozzle 6 with a burner (e.g., an industrial burner) achieves several significant advantages, especially in terms of environmental sustainability, operating efficiency, and cost savings. The advantages of the fuel nozzle 6 include reduced emissions and improved combustion efficiency. With regard to reduced emissions, the main advantage of using a low-emission swirl fuel nozzle 6 is a significant reduction in harmful emissions such as nitrogen oxides (NOx), carbon monoxide (CO), and particulate matter (PM). This emission reduction can help various industries meet strict environmental regulations and reduce their carbon footprint, thereby helping to achieve cleaner air and a healthier environment.

[0056] The swirl fuel nozzle is designed to produce a controlled swirling air flow within the combustion chamber. This enhanced mixing of air and fuel enables more efficient and complete combustion, maximizing heat transfer and energy conversion. The improved combustion efficiency translates into lower fuel consumption and reduced operating costs.

[0057] Another advantage of the fuel nozzle 6 includes the production of a stable flame. The swirl fuel nozzle 6 can promote flame stability, even in challenging conditions such as low fuel flow rates or changing fuel compositions. This stability ensures continuous and reliable combustion, thereby reducing the risk of flame extinguishing and downtime. Another advantage of the fuel nozzle 6 is its flexibility and versatility. The low emission swirl fuel nozzle 6 is suitable for a variety of fuel types and compositions, making it versatile for a wide range of industrial applications. This flexibility enables industries to switch between different fuels as needed, including cleaner alternative fuels such as natural gas or biofuels.

[0058] The fuel nozzle 6 may also result in reduced maintenance. That is, improving combustion efficiency and stabilizing the flame by swirl fuel nozzle 6 may result in less wear and tear on combustor components. This may result in longer equipment life and reduced maintenance requirements, saving time and money. The fuel nozzle 6 also achieves energy conservation advantages. Improving combustion efficiency is directly related to energy conservation. Industries can reduce their fuel consumption while achieving the same heat output, resulting in lower energy costs and improved competitiveness.

[0059] The fuel nozzle 6 also helps meet regulatory compliance. Many regions have strict emission regulations that industrial facilities must meet. Implementing a low emission swirl fuel nozzle 6 can ensure compliance with these regulations and avoid potential fines and penalties.

[0060] Other advantages achieved by the fuel nozzle 6 include heat transfer optimization and enhanced process control. With regard to heat transfer optimization, the swirl fuel nozzle 6 can improve heat transfer in the combustion chamber, which is critical in processes that require heat, such as in industrial furnaces and boilers. This results in faster heat-up times and more uniform temperature distribution. The swirl fuel nozzle 6 also enables greater control over the combustion process. In addition, the enhanced control system can be used to adjust the air-fuel ratio and other parameters in real time, thereby optimizing combustion to adapt to changing operating conditions and load requirements.

[0061] Implementing low emission swirl fuel nozzles with industrial burners provides a range of overall benefits, ranging from reduced emissions and increased efficiency to cost savings and regulatory compliance. These benefits make it a compelling choice for industries looking to improve their environmental performance and operating efficiency while remaining competitive in today's environmentally conscious world.

[0062] Figure 5A flow chart depicting the operation of a method 100 for operating a fuel nozzle 6 according to one embodiment is shown. As indicated by block 102, steps or operations may be performed to receive air and fuel in an inner mixing chamber and an outer mixing chamber, respectively, located in the fuel nozzle 6. Next, as indicated by block 104, steps or operations may be performed to combine the air and fuel to form an air and fuel mixture, wherein the fuel may enter the inner mixing chamber through a first hole pattern formed in the fuel nozzle 6, and may enter the outer mixing chamber through a second hole pattern formed in the fuel nozzle 6.

[0063] Then, as indicated at block 106, steps or operations may be performed to utilize angled discharge ports included with the inner mixing chamber to slow the exit velocity of the air and fuel mixture prior to exiting the fuel nozzle 6 through the discharge end of the fuel nozzle 6. As indicated at block 108, these chambers, along with the first and second hole patterns and the angled discharge ports, can facilitate flame stabilization at two different points downstream of the fuel nozzle 6, depending on the flow rates of the fuel and air.

[0064] Based on the foregoing, it can be understood that many different embodiments, including preferred and alternative embodiments, are disclosed herein. For example, in one embodiment, a fuel nozzle may include: a plurality of chambers located in the fuel nozzle, wherein the plurality of chambers include an inner mixing chamber and an outer mixing chamber, wherein the inner mixing chamber and the outer mixing chamber each receive air and fuel respectively and merge the air and fuel to form a mixture of air and fuel; a first hole pattern and a second hole pattern, the first hole pattern and the second hole pattern are formed in the fuel nozzle, wherein the fuel enters the inner mixing chamber through the first hole pattern and enters the outer mixing chamber through the second hole pattern; an angled discharge port, the angled discharge port is included with the inner mixing chamber, wherein the angled discharge port slows down the exit velocity of the mixture of air and fuel before it exits the fuel nozzle through the discharge end of the fuel nozzle, wherein the plurality of chambers together with the first hole pattern and the second hole pattern and the angled discharge port promote the stabilization of the flame at two different points downstream of the fuel nozzle, depending on the flow rate of the fuel and air.

[0065] In one embodiment, the outer mixing chamber may include a combination of spaces created between a plurality of vanes and an air housing.

[0066] In one embodiment, a plurality of vanes may be positioned at an angle to the long axis of the combustor to create a swirling flow at the discharge end of the fuel nozzle.

[0067] One embodiment may include a plurality of vanes positioned at an angle to the long axis of the combustor to create a swirling flow at the discharge end of the nozzle.

[0068] In one embodiment, fuel may enter the fuel nozzle through a fuel inlet and may proceed to the inner mixing chamber where the fuel may be distributed to both the inner and outer mixing chambers.

[0069] In one embodiment, fuel may enter the inner mixing chamber through the first hole pattern at a desired amount and rate.

[0070] In one embodiment, fuel may enter the outer mixing chamber through the second hole pattern at a desired amount and velocity.

[0071] In one embodiment, the flame may be swirl stabilized downstream of the fuel nozzle.

[0072] In one embodiment, as fuel capacity decreases, the flame may undergo a stability transition immediately downstream of the discharge end of the fuel nozzle.

[0073] In one embodiment, a fuel nozzle may include: a plurality of chambers located in the fuel nozzle, wherein the plurality of chambers include an inner mixing chamber and an outer mixing chamber, wherein the inner mixing chamber and the outer mixing chamber each receive air and fuel, respectively, and combine the air and fuel to form an air and fuel mixture; and an angled discharge port included with the inner mixing chamber, wherein the angled discharge port slows down the exit velocity of the air and fuel mixture before it exits the fuel nozzle through a discharge end of the fuel nozzle, wherein the plurality of chambers and the angled discharge port promote flame stabilization at two different points downstream of the fuel nozzle, depending on the flow rate of the fuel and air.

[0074] In one embodiment, the first hole pattern and the second hole pattern may be configured by the fuel nozzle such that fuel may enter the inner mixing chamber through the first hole pattern and enter the outer mixing chamber through the second hole pattern.

[0075] In one embodiment, a method of operating a fuel nozzle may involve: receiving air and fuel in an inner mixing chamber and an outer mixing chamber, respectively, among a plurality of chambers located in the fuel nozzle; combining the air and the fuel to form a mixture of air and fuel, wherein the fuel enters the inner mixing chamber through a first hole pattern formed in the fuel nozzle and enters the outer mixing chamber through a second hole pattern formed in the fuel nozzle; and utilizing an angled discharge port included with the inner mixing chamber to slow down an exit velocity of the mixture of air and fuel before it exits the fuel nozzle through a discharge end of the fuel nozzle.

[0076] In one embodiment of the method, multiple chambers along with first and second hole patterns and angled discharge ports may facilitate flame stabilization at two different points downstream of the fuel nozzle, depending on the flow rates of fuel and air.

[0077] In one embodiment of the method, the outer mixing chamber may include a combination of spaces created between the plurality of vanes and the air housing.

[0078] In one embodiment of the method, a plurality of vanes may be positioned at an angle to the long axis of the combustor to produce a swirling flow at the discharge end of the fuel nozzle.

[0079] One embodiment of the method may involve generating a swirling flow at a discharge end of a nozzle wherein a plurality of vanes are positioned at an angle to a long axis of the combustor.

[0080] In one embodiment of the method, fuel may enter the fuel nozzle through a fuel inlet and may proceed to the inner mixing chamber where the fuel may be distributed to both the inner mixing chamber and the outer mixing chamber.

[0081] In one embodiment of the method, fuel may enter the inner mixing chamber through the first hole pattern in a desired amount and velocity.

[0082] In one embodiment of the method, fuel may enter the outer mixing chamber through the second hole pattern in a desired amount and velocity.

[0083] In one embodiment of the method, the flame may be swirl stabilized downstream of the fuel nozzle and as fuel capacity decreases, the flame may transition to stability immediately downstream of the discharge end of the fuel nozzle.

[0084] In the above description, the specific details of various embodiments are provided. However, some embodiments may be implemented with less than all of these specific details. In other cases, for the sake of brevity and clarity, the specific methods, procedures, components, structures and / or functions of implementing various embodiments are no longer described in detail.

[0085] Although the operation of method is shown and described in a particular order herein, the order of operation of each method can be changed so that some operations can be performed in reverse order, or some operations can be performed at least partially simultaneously with other operations. In another embodiment, the instructions or sub-operations of different operations can be implemented in an intermittent and / or alternating manner.

[0086] It should also be noted that at least some of the operations of the methods described herein can be implemented using software instructions stored on a computer-usable storage medium for execution by a computer. For example, one embodiment of a computer program product includes a computer-usable storage medium for storing a computer-readable program.

[0087] A computer usable or computer readable storage medium may be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device). Examples of non-transitory computer usable and computer readable storage media include semiconductor or solid-state memory, magnetic tape, removable computer disk, random access memory (RAM), read-only memory (ROM), rigid disk, and optical disk. Current examples of optical disks include compact disk with read-only memory (CD-ROM), compact disk with read / write (CD-R / W), digital video disk (DVD).

[0088] Alternatively, the embodiments may be implemented entirely in hardware or in a specific implementation comprising both hardware elements and software elements. In embodiments using software, the software may include but is not limited to firmware, resident software, microcode, etc.

[0089] It will be appreciated that the variations disclosed above and other features and functions or their alternatives may be advantageously combined into many other different systems or applications. It will also be appreciated that various currently unforeseen or unanticipated alternatives, modifications, variations or improvements may be subsequently made by those skilled in the art, which are also intended to be covered by the following claims.

Claims

1. A fuel nozzle, comprising: a plurality of chambers located in the fuel nozzle, wherein the plurality of chambers include an inner mixing chamber and an outer mixing chamber, wherein the inner mixing chamber and the outer mixing chamber each receive air and fuel, respectively, and combine the air and the fuel to form a mixture of the air and the fuel; a first hole pattern and a second hole pattern, the first hole pattern and the second hole pattern formed in the fuel nozzle, wherein the fuel enters the inner mixing chamber through the first hole pattern and enters the outer mixing chamber through the second hole pattern; as well as angled discharge ports included with the inner mixing chamber, wherein the angled discharge ports slow down an exit velocity of the mixture of the air and the fuel prior to exiting the fuel nozzle through a discharge end of the fuel nozzle, wherein the plurality of chambers together with the first and second hole patterns and the angled discharge ports facilitate flame stabilization at two different points downstream of the fuel nozzle depending on flow rates of the fuel and the air. 2 . The fuel nozzle of claim 1 , wherein the outer mixing chamber comprises a combination of spaces formed between a plurality of vanes and an air casing. 3 . The fuel nozzle of claim 2 , wherein the plurality of vanes are positioned at an angle to a long axis of a combustor to produce a swirling flow at the discharge end of the fuel nozzle.

4. The fuel nozzle of claim 1 further comprising a plurality of vanes positioned at an angle to a long axis of the combustor to produce a swirling flow at the discharge end of the nozzle.

5. The fuel nozzle of claim 1, wherein the fuel enters the fuel nozzle through a fuel inlet and continues to the inner mixing chamber where the fuel is distributed to both the inner mixing chamber and the outer mixing chamber. The fuel nozzle of claim 1 , wherein the flame is swirl-stabilized downstream of the fuel nozzle.

7. The fuel nozzle of claim 1, wherein the flame undergoes a stability transition immediately downstream of the discharge end of the fuel nozzle as the fuel capacity decreases.

8. A fuel nozzle, comprising: a plurality of chambers located in the fuel nozzle, wherein the plurality of chambers include an inner mixing chamber and an outer mixing chamber, wherein the inner mixing chamber and the outer mixing chamber each receive air and fuel, respectively, and combine the air and the fuel to form a mixture of the air and the fuel; as well as angled discharge ports included with the inner mixing chamber, wherein the angled discharge ports slow the exit velocity of the mixture of the air and the fuel prior to exiting the fuel nozzle through a discharge end of the fuel nozzle, wherein the multiple chambers and the angled discharge ports promote flame stabilization at two different points downstream of the fuel nozzle, depending on the flow rates of the fuel and the air.

9. A method of operating a fuel nozzle, comprising: receiving air and fuel in inner and outer mixing chambers, respectively, of a plurality of chambers located in the fuel nozzle; combining the air and the fuel to form a mixture of the air and the fuel, wherein the fuel enters the inner mixing chamber through a first hole pattern formed in the fuel nozzle and enters the outer mixing chamber through a second hole pattern formed in the fuel nozzle; and An angled discharge port included with the inner mixing chamber is utilized to slow down an exit velocity of the mixture of the air and the fuel prior to exiting the fuel nozzle through a discharge end of the fuel nozzle.

10. The method of claim 9, wherein the plurality of chambers, along with the first and second hole patterns and the angled discharge ports, facilitate flame stabilization at two different points downstream of the fuel nozzle, depending on flow rates of the fuel and the air.

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