TURBINE ENGINE HAVING AN OPTICAL SENSOR

Description

TECHNICAL FIELD

The present subject matter relates generally to a turbine engine having a fuel nozzle assembly and an optical sensor.

BACKGROUND

Turbine engines are driven by a flow of combustion gases passing through the engine to rotate a multitude of turbine blades, which, in turn, rotate a compressor to provide compressed air to the combustor for combustion. A combustor can be provided within the turbine engine and is fluidly coupled with a turbine into which the combusted gases flow.

Historically, hydrocarbon fuels are used in the combustor of a turbine engine. Generally, air and fuel are fed to a combustion chamber, the air and fuel are mixed, and then the fuel is burned in the presence of the air to produce hot gas. The hot gas is then fed to a turbine where it cools and expands to produce power. Byproducts of the fuel combustion typically include environmentally unwanted byproducts, such as nitrogen oxide and nitrogen dioxide (collectively called NO_x), carbon monoxide (CO), unburned hydrocarbons (UHC) (e.g., methane and volatile organic compounds that contribute to the formation of atmospheric ozone), and other oxides, including oxides of sulfur (e.g., SO₂ and SO₃).

To reduce the environmentally unwanted byproducts, other fuels, such as hydrogen, are being explored. Hydrogen or hydrogen mixed with another element has a higher flame temperature than traditional hydrocarbon fuels. That is, hydrogen or a hydrogen mixed fuel typically has a wider flammable range and a faster burning velocity than traditional hydrocarbon-based fuels.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a schematic view of a turbine engine having a compression section, a combustion section, and a turbine section.

FIG. 2 is a schematic view of the combustion section of FIG. 1 along line II-II in accordance with various aspects described herein.

FIG. 3 is a schematic cross-sectional view of the fuel nozzle assembly and combustion chamber of FIG. 2 along line III-III in accordance with various aspects described herein.

FIG. 4 is a schematic cross-sectional view of the fuel nozzle body of FIG. 3 along line IV-IV.

FIG. 5 is a block diagram depicting an embodiment of a method of operating a turbine engine in accordance with various aspects described herein.

DETAILED DESCRIPTION

Aspects of the disclosure described herein are directed to a combustor and a fuel nozzle assembly for a combustor of a turbine engine. With some aspects, the disclosed combustors and fuel nozzle assemblies can be utilized with a translucent or transparent gaseous fuel, such as hydrogen. Gaseous fuels, including hydrogen, spread/disperse at a faster rate than liquid fuels that require atomization, which can involve less mixing time for the gaseous fuel, fuel mixing tube lengths can be shorter, and the flame from the gaseous fuel can be more likely to spread farther and faster, which can increase the risk of flashback and flameholding (e.g., in a nozzle or mixer), and increase the impact of controlling the flame and limiting flame spread by controlling the dispersion of the gaseous fuel.

A quick responding fuel control system can be used to control the flow of gaseous fuel in the turbine engine. Improved response times and control over the fuel flow can be accomplished by quick detection of lightoff of a combustion flame in a combustion chamber by a controller. An optical sensor submerged in the unburned hydrogen-based fuel can quickly detect the combustion flame. Hydrogen-based fuel is typically a colorless fuel that is translucent or even transparent. That is, an electromagnetic (EM) wave, including for example light, can be detected by the optical sensor circumscribed by the hydrogen-based fuel or other translucent or transparent fuel.

After an ignition attempt, the optical sensor immersed in the hydrogen-based fuel can detect an EM wave from the combustion flame and send a signal indicating confirmed lightoff to a controller. Based on the signal indicative of a confirmed lightoff, one or more components of a fuel control system can continue the flow of the hydrogen-based fuel. Conversely, if the optical sensor does not detect an EM wave from a combustion flame one or more components of a fuel control system can stop the flow of the hydrogen-based fuel. Quickly stopping the flow of the hydrogen-based fuel when no combustion flame is detected after an ignition attempt, prevents unburned hydrogen-based fuel from accumulating in one or more portions of the turbine engine.

Since the optical sensor can detect an EM wave within a predetermined range from within the unburned hydrogen-based fuel, the optical sensor remains in an environment that is in a range of −100° F. to 400° F. (−73° C. to 204° C.). As such, there is no need for high temperature resistant sheathing or coating on the optical sensor when compared to traditional optical sensors coupled to the combustion chamber. Traditional optical sensors coupled to the combustion chamber are in or near an environment that can have a temperature of 3000° F. (approximately 1649° C.) or more. Thus, the optical sensor as described herein benefits from the flow of hydrogen-based fuel around the optical sensor, which acts as a cooling medium and maintains the optical sensor at a relatively low temperature.

While described with respect to a turbine engine, it should be appreciated that the combustor as described herein can be for any engine having a combustor. The combustor as described herein can be implemented in various engines, including but not limited to engines with propeller sections or fan and booster sections, along with turbojet, turboprop, turboshaft, and turbofan engines. Aspects of the disclosure discussed herein can have general applicability within non-aircraft engines having a combustor, such as other mobile applications and non-mobile industrial, commercial, and residential applications.

With the combustors and fuel nozzle assemblies described herein, the hydrogen-based fuel can be gaseous hydrogen fuel used without the need of diluents. In some embodiments, no diluent is added to the combustion chamber and the fuel is substantially completely diatomic hydrogen without diluent. As used herein, the term “substantially completely,” as used to describe the amount of a particular element or molecule (e.g., diatomic hydrogen), refers to at least 99% by mass of the described portion of the element or molecule, such as at least 97.5%, such as at least 95%, such as at least 92.5%, such as at least 90%, such as at least 85%, or such as at least 75% by mass of the described portion of the element or molecule. In some examples, the fuel is entirely (e.g., 100%) hydrogen by mass.

The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations. Additionally, unless specifically identified otherwise, all embodiments described herein should be considered exemplary.

The terms “forward” and “aft” refer to relative positions within a turbine engine or vehicle, and are based on a normal operational attitude of the turbine engine or vehicle. More particularly, forward and aft are used herein with reference to a direction of travel of the vehicle and a direction of propulsive thrust of the turbine engine.

The terms “upstream” and “downstream” refer to the relative direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the direction from which the fluid flows, and “downstream” refers to the direction to which the fluid flows.

The term “fluid” can be a gas or a liquid. The term “fluidly coupled” means that a fluid is capable of making the connection between the areas specified.

The term “nozzle” has been used in various ways in the context of turbine engines. In the instant application, “nozzle” refers to a component having a portion for fluid coupling to a fuel supply and having at least one portion for fluidly coupling with a combustor portion, a combustor liner, a combustion chamber, or combinations thereof.

All directional references (e.g., radial, axial, upper, lower, upward, downward, left, right, front, back, top, bottom, above, below, vertical, horizontal, upstream, downstream, forward, aft, etc.) are only used for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of aspects of the disclosure described herein. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and can include intermediate structural elements between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to one another. The exemplary drawings are for purposes of illustration only, and the dimensions, positions, order, and relative sizes reflected in the drawings attached hereto can vary.

The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. Furthermore, as used herein, the term “set” or a “set” of elements can be any number of elements, including only one. Uses of “and” and “or” are to be construed broadly. For example and without limitation, uses of “and” do not necessarily require all elements or features listed, and uses of “or” are inclusive unless such a construction would be illogical.

Additionally, as used herein, a “controller” can include a component configured or adapted to provide instruction, control, operation, or any form of communication for operable components to effect the operation thereof. A controller can include any known processor, microcontroller, or logic device, including, but not limited to: field programmable gate arrays (FPGA), an application specific integrated circuit (ASIC), a full authority digital engine control (FADEC), a proportional controller (P), a proportional integral controller (PI), a proportional derivative controller (PD), a proportional integral derivative controller (PID controller), proportional resonant controller (PR), a hardware-accelerated logic controller (e.g. for encoding, decoding, transcoding, etc.), the like, or a combination thereof. Non-limiting examples of a controller can be configured or adapted to run, operate, or otherwise execute program code to effect operational or functional outcomes, including carrying out various methods, functionality, processing tasks, calculations, comparisons, sensing or measuring of values, or the like, to enable or achieve the technical operations or operations described herein. The operation or functional outcomes can be based on one or more inputs, stored data values, sensed or measured values, true or false indications, or the like. While “program code” is described, non-limiting examples of operable or executable instruction sets can include routines, programs, objects, components, data structures, algorithms, etc., that have the technical effect of performing particular tasks or implement particular abstract data types. In another non-limiting example, a controller can also include a data storage component accessible by the processor, including memory, whether transient, volatile or non-transient, or non-volatile memory.

Additional non-limiting examples of the memory can include Random Access Memory (RAM), Read-Only Memory (ROM), flash memory, or one or more different types of portable electronic memory, such as discs, DVDs, CD-ROMs, flash drives, universal serial bus (USB) drives, the like, or any suitable combination of these types of memory. In one example, the program code can be stored within the memory in a machine-readable format accessible by the processor. Additionally, the memory can store various data, data types, sensed or measured data values, inputs, generated or processed data, or the like, accessible by the processor in providing instruction, control, or operation to effect a functional or operable outcome, as described herein. In another non-limiting example, a controller can be configured for comparing a first value with a second value and operating and controlling operations of additional components based on the satisfying of that comparison. For example, when a sensed, measured, or provided value is compared with another value, including a stored or predetermined value, the satisfaction of that comparison can result in actions, functions, or operations controllable by the controller.

As used herein, while sensors can be described as “sensing” or “measuring” a respective value, sensing or measuring can include determining a value indicative of or related to the respective value, rather than directly sensing or measuring the value itself. The sensed or measured values can further be provided to additional components. For instance, the value can be provided to a controller module or processor as defined above, and the controller module or processor can perform processing on the value to determine a representative value or an electrical characteristic representative of said value.

FIG. 1 is a schematic view of a turbine engine 10. As a non-limiting example, the turbine engine 10 can be used within an aircraft. The turbine engine 10 can include, at least, a compressor section 12, a combustion section 14, and a turbine section 16. A drive shaft 18 rotationally couples the compressor section 12 and turbine section 16, such that rotation of one affects the rotation of the other, and defines a rotational axis that is an engine centerline 20 for the turbine engine 10.

The compressor section 12 can include a low-pressure (LP) compressor 22, and a high-pressure (HP) compressor 24 serially fluidly coupled to one another. The turbine section 16 can include an HP turbine 26, and an LP turbine 28 serially fluidly coupled to one another. The drive shaft 18 can operatively couple the LP compressor 22, the HP compressor 24, the HP turbine 26 and the LP turbine 28 together. Alternatively, the drive shaft 18 can include an LP drive shaft and an HP drive shaft. The LP drive shaft can couple the LP compressor 22 to the LP turbine 28, and the HP drive shaft can couple the HP compressor 24 to the HP turbine 26. An LP spool can be defined as the combination of the LP compressor 22, the LP turbine 28, and the LP drive shaft such that the rotation of the LP turbine 28 can apply a driving force to the LP drive shaft, which in turn can rotate the LP compressor 22. An HP spool can be defined as the combination of the HP compressor 24, the HP turbine 26, and the HP drive shaft such that the rotation of the HP turbine 26 can apply a driving force to the HP drive shaft which in turn can rotate the HP compressor 24.

The compressor section 12 can include a plurality of axially spaced stages. Each stage includes a set of circumferentially spaced rotating blades and a set of circumferentially spaced stationary vanes. The compressor blades for a stage of the compressor section 12 can be mounted to a disk, which is mounted to the drive shaft 18. Each set of blades for a given stage can have its own disk. The vanes of the compressor section 12 can be mounted to a casing which can extend circumferentially about and enshroud one or more sections of the turbine engine 10. It will be appreciated that the representation of the compressor section 12 is merely schematic and that there can be any number of blades, vanes and stages. Further, it is contemplated that there can be any number of other components within the compressor section 12.

Similar to the compressor section 12, the turbine section 16 can include a plurality of axially spaced stages, with each stage having a set of circumferentially spaced, rotating blades and a set of circumferentially spaced, stationary vanes. The turbine blades for a stage of the turbine section 16 can be mounted to a disk which is mounted to the drive shaft 18. Each set of blades for a given stage can have its own disk. The vanes of the turbine section 16 can be mounted to the casing in a circumferential manner. It is noted that there can be any number of blades, vanes and turbine stages as the illustrated turbine section 16 is merely a schematic representation. Further, it is contemplated that there can be any number of other components within the turbine section 16.

The combustion section 14 can be provided serially between the compressor section 12 and the turbine section 16. The combustion section 14 can be fluidly coupled to at least a portion of the compressor section 12 and the turbine section 16 such that the combustion section 14 at least partially fluidly couples the compressor section 12 to the turbine section 16. As a non-limiting example, the combustion section 14 can be fluidly coupled to the HP compressor 24 at an upstream end of the combustion section 14 and to the HP turbine 26 at a downstream end of the combustion section 14. The combustion section 14 can include a combustor 30.

During operation of the turbine engine 10, ambient or atmospheric air is drawn into the compressor section 12 via a fan upstream of the compressor section 12, where the air is compressed defining a pressurized air A (FIG. 3). The pressurized air A can then flow into the combustion section 14 where the pressurized air A is mixed with fuel F (FIG. 3) and ignited, thereby generating combustion gases. Some work is extracted from these combustion gases by the HP turbine 26, which drives the HP compressor 24. The combustion gases are discharged into the LP turbine 28, which extracts additional work to drive the LP compressor 22, and the exhaust gas is ultimately discharged from the turbine engine 10 via an exhaust section downstream of the turbine section 16. The driving of the LP turbine 28 drives the LP spool to rotate the fan and the LP compressor 22. The pressurized airflow and the combustion gases can together define a working airflow that flows through the fan, compressor section 12, combustion section 14, and turbine section 16 of the turbine engine 10.

FIG. 2 depicts a cross-sectional view of the combustion section 14 along line II-II of FIG. 1. The combustor 30 can include a circumferentially spaced set of combustor portions 31 disposed around the engine centerline 20 of the turbine engine 10 (e.g., circumferentially spaced from each other in an annular configuration) (FIG. 1). The set of combustor portions 31 can, in some configurations, include or be configured as combustor cups, fuel cups, or nozzle cups. The combustor 30 can have a can, can-annular, or annular arrangement depending on the type of engine in which the combustor 30 is located. In a non-limiting example, the combustor 30 can have a combination arrangement located with a shroud or casing 29 of the turbine engine 10 (FIG. 1). The shroud or casing 29 can enshroud or cover at least a portion of the combustion section 14.

A fuel nozzle assembly can be connected to each combustor portion 31 of the set of combustor portions 31. Particularly, a fuel nozzle assembly 48 as described herein can be a single fuel nozzle assembly 48 or a plurality of fuel nozzle assemblies 48 each connected to one of a critical subset of the set of combustor portions 31, or one of a non-critical subset of the set of combustor portions. The critical subset and the non-critical subset of the set of combustor portions 31 can each include one of the set of combustor portions 31, more than one but less than all of the set of combustor portions 31, or all of the set of combustor portions 31.

The combustor 30 can be at least partially defined by a combustor liner 40. In some examples, the combustor liner 40 can include an outer liner 41 and an inner liner 42 concentric with respect to each other and arranged in an annular fashion about the engine centerline 20. In some examples, the combustor liner 40 can have an annular structure about the combustor 30. In some examples, the combustor liner 40 can include multiple segments or portions collectively forming the combustor liner 40. In some examples, the combustor liner 40 can include the outer liner 41 radially spaced from the inner liner 42. In some examples, the combustor liner 40 can include a single liner.

The combustor liner 40 can at least partially define a combustion chamber 50 arranged annularly about the engine centerline 20. For example, a wall 46 (e.g., a dome wall) can be perpendicular to the engine centerline 20 and can cooperate with the outer liner 41, the inner liner 42, or both, to at least partially define the combustion chamber 50. A compressed air passage 32 can be defined at least in part by both the combustor liner 40 and the casing 29. As used herein, the term “perpendicular” refers to generally perpendicular, where the angle between a first line or first plane and a second line or second plane are in a range from 70° to 110°. For example, intersection of a plane defined by the wall 46 and the engine centerline 20 can form an angle in a range from 80° to 100°.

The combustor 30 can include or be fluidly coupled to a fuel supply 34 (e.g., a fuel manifold or conduit). The fuel nozzle assembly 48 is fluidly coupled with the fuel supply 34 by at least one fuel supply valve 36 (FIG. 3). The fuel nozzle assembly 48 is also fluidly coupled with one of the combustor portions 31 and the combustion chamber 50.

A fuel F can include any suitable transparent or translucent fuel, including gaseous fuel, such as hydrogen fuel, in non-limiting examples, which can include 100% H₂ (e.g., without a diluent). Transparent, as used herein, refers to having the property of allowing light to pass through without appreciable scattering such that any shape lying beyond is seen clearly. Translucent, as used herein, refers to the property of allowing light to pass through, but not detailed shapes. For example, the fuel nozzle assembly 48 can be a gaseous fuel nozzle assembly, such as a gaseous hydrogen fuel nozzle assembly, and the fuel supply 34 can be a hydrogen fuel supply. In some examples, other fuels can be utilized instead of or with hydrogen provided that the fuel is transparent or translucent. For example, the fuel F can comprise methane, such as in the form of natural gas, highly reactive fuels, or combinations thereof, with or without hydrogen and the fuel nozzle assembly 48 can be a translucent fuel, fuel nozzle assembly. The fuel F can have a temperature in the range of −100° F. to 400° F. (−73° C. to 204° C.).

The combustor portions 31 can be arranged in a circumferentially spaced configuration. The combustor portions 31 can be disposed at a radial distance from the engine centerline 20 that is greater than a radial distance of the inner liner 42 and less than a radial distance of the outer liner 41. A controller 60 can be connected to and at least partially control operation of the fuel supply 34 and the fuel nozzle assembly 48, or a combination thereof. The controller 60 can include a processor 62 and a memory 64.

FIG. 3 depicts a cross-sectional view of portions of the fuel nozzle assembly 48 and a combustor portion 31 along line III-III in FIG. 2. The fuel nozzle assembly 48 includes a fuel supply passage 70. The fuel supply passage 70 includes a fuel supply passage outlet 72 fluidly coupled to the combustion chamber 50. The fuel supply passage 70 can include one or more of a tube, channel, conduit, or other structures through which fuel F can flow. That is, the fuel nozzle assembly 48 provides fuel F to the combustion chamber 50 at the fuel supply passage outlet 72.

The fuel nozzle assembly 48 can further include an air supply passage 74 that provides air A. The air supply passage 74 can be coupled to an air supply, such as the compressor section 12.

To supply the fuel F and the air A to the combustion chamber 50, the fuel nozzle assembly 48 is illustrated, by way of example, as having the fuel supply passage 70 and the air supply passage 74. Additionally, or alternatively, the fuel nozzle assembly 48 can include a swirler, or any other structure or structures to supply fuel F, air A, or a mixture of fuel F and air A to the combustion chamber 50. It is contemplated that the swirler or other structures can supply fuel, air, or a combination of fuel and air from an additional fuel supply, additional air supply or conduit, or any combination thereof.

A portion of the fuel nozzle assembly 48 can pass through at least one of the combustor liner 40 or the wall 46. In some configurations, the fuel nozzle assembly 48 can be coupled to the combustor liner 40 via the wall 46. In other configurations, the fuel nozzle assembly 48 can be coupled directly to the combustor liner 40.

The fuel supply passage 70 defines a fuel supply passage centerline 78. As illustrated, by way of example, the fuel supply passage centerline 78 can extend axially, radially, or any combination thereof. An inner surface 79 of the fuel supply passage 70 circumscribes the fuel supply passage centerline 78 and defines an interior 80.

The fuel supply passage 70 is coupled with the fuel supply 34 at an upstream portion 76 of fuel supply passage 70. The fuel supply passage outlet 72 is the location at which the fuel F leaves the interior 80 of the fuel supply passage 70 and enters the combustion chamber 50.

The fuel supply passage outlet 72 defines an outlet plane 82. Optionally, the outlet plane 82 can be perpendicular to the engine centerline 20. An outlet centerline 84 is defined by the fuel supply passage outlet 72. The outlet centerline 84 extends perpendicular to the outlet plane 82 defined by the fuel supply passage outlet 72. Optionally, the outlet centerline 84 and the engine centerline 20 can be parallel or non-intersecting.

As illustrated by way of example, the fuel supply passage centerline 78 and the outlet centerline 84 can intersect or abut at the fuel supply passage outlet 72. However, it is contemplated that the outlet centerline 84 can be angled or radially spaced from the fuel supply passage centerline 78.

A set of fixture plates 86a, 86b, 86c are located within the fuel supply passage 70.

Although the set of fixture plates 86a, 86b, 86c is illustrated as having three fixture plates, it is contemplated that the set of fixture plates 86a, 86b, 86c can include any number of fixture plates, including one fixture plate. The set of fixture plates 86a, 86b, 86c can extend across the interior 80 of the fuel supply passage 70 and be oriented at a non-zero angle with respect to a direction of the flow of the fuel F in the fuel supply passage 70. Each fixture plate of the set of fixture plates 86a, 86b, 86c includes a set of fixture holes 88. The set of fixture holes 88 allow fuel F to flow through the set of fixture plates 86a, 86b, 86c along the fuel supply passage 70.

An igniter 90 is disposed at least partially within the combustion chamber 50 to ignite a mixture of fuel F and air A forming a combustion flame 92 in the combustion chamber 50, also known as lightoff. The igniter 90 can extend through the wall 46, the combustor liner 40, or a combination thereof. An optical sensor 100 detects the presence of the combustion flame 92.

The optical sensor 100 is at least partially located within the fuel supply passage 70. That is, the optical sensor 100 can be located in the interior 80 of the fuel supply passage 70. The optical sensor 100 can be circumscribed by the fuel F in the interior 80 such that the optical sensor 100 does not make direct physical contact with the inner surface 79 of the fuel supply passage 70. Alternatively or additionally, the optical sensor 100 can be embedded in the inner surface 79 of the fuel supply passage 70. It is contemplated that the optical sensor 100 can be embedded in the inner surface 79 of the fuel supply passage 70 such that the optical sensor 100 is still fuel F acts as a cooling medium.

The optical sensor 100 can, for example, detect an EM wave. The EM wave can have a wavelength in a range of 200 nanometers (nm) to 1100 nm, which includes visible light, but is not limited to the visual light spectrum because light generated by the combustion flame 92 can include ultraviolet (UV) light, visible light, infrared (IR) light, or a combination thereof. Further, the fuel F can include additives which can facilitate better flame visibility extending beyond visible light. The optical sensor 100 can generate and transmit a stable signal to the controller 60 (FIG. 2) within, for example, 10 milliseconds (ms) of the optical sensor 100 receiving an input from an EM wave in a detectable region 102 of the combustion chamber 50.

An EM wave having a wavelength in the range of 200 nm to 1100 nm is indicative of lightoff, illustrated as the combustion flame 92. The optical sensor 100 can include, for example, a fiber optic cable, an ultraviolet optical sensor, an infrared optical sensor, or a combination thereof connected to a photodetector such as a photodiode or photomultiplier. Optionally the optical sensor 100 can include a signal multiplier, an amplification device, or a combination thereof. For example, the optical sensor 100 can be made of silicon (Si), germanium (Ge), silicon carbide (SiC), indium gallium arsenide (InGaAs), gallium arsenide (GaAs), or a combination thereof, but is not limited hereto. It should be understood that any sensor capable of detecting an EM wave of a flame can be the optical sensor 100.

The optical sensor 100 is oriented to detect the presence of the combustion flame 92 within the detectable region 102 of the combustion chamber 50, also referred to as having a line of sight to the detectable region 102. The detectable region 102 can be defined as a volume of a portion of the combustion chamber 50 within a boundary 104. The boundary 104 and the outlet centerline 84 form an angle 106 in a range from 70° to 110°. A downstream terminal end 105 of the optical sensor 100 can be located upstream of the fuel supply passage outlet 72. That is, the downstream terminal end 105 can be a distance 107 that is in a range of 50% to 500% of a fuel supply passage diameter 108 measured at the fuel supply passage outlet 72. Optionally, a non-limiting example of the distance 107 is less than 20 millimeters (mm).

FIG. 4 shows a schematic cross-sectional view of the fuel supply passage 70 along line IV-IV in FIG. 3. The optical sensor 100 can be positioned in the interior 80 (FIG. 3) of the fuel supply passage 70 by passing the optical sensor 100 through a fixture hole 88a of the set of fixture holes 88 in at least one fixture plate 86a of the set of fixture plates 86a, 86b, 86c (FIG. 3).

The set of fixture holes 88 can be a set of through holes formed in the set of fixture plates 86a, 86b, 86c (FIG. 3). Although FIG. 4 depicts the set of fixture holes 88 as equally sized circles, the particular shape of the set of fixture holes 88 is not limited. Alternatively, the set of fixture holes 88 can be polygonal, elliptical, circular, or any combination thereof.

By way of non-limiting example, the optical sensor 100 can have a sensor diameter 110. The fixture hole 88a of the set of fixture holes 88 can have an aperture diameter 112. The sensor diameter 110 is less than the aperture diameter 112, which ensures that the optical sensor 100 is suspended within the fuel supply passage 70. The sensor diameter 110 must be small enough that it does not disrupt the flow of fuel F through the fuel supply passage 70. In non-limiting examples, the sensor diameter 110 can be in a range from 30 micrometers (μm) to 10 mm or more and the aperture diameter 112 can be in a range from 0.2 mm to 4 mm.

The particular fixture plate of the set of fixture plates 86a, 86b, 86c and particular fixture hole of the set of fixture holes 88 through which the optical sensor 100 passes is not limited as long as the optical sensor 100 maintains line of sight to the detectable region 102. For example, the optical sensor 100 can pass through a fixture hole 88a located along the fuel supply passage centerline 78 as shown in FIG. 4 or through another fixture hole 88b of the set of fixture holes 88 that is offset from the fuel supply passage centerline 78.

Although fixture plates 86a, 86b, 86c are illustrated, other means of positioning the optical sensor 100 within the fuel supply passage 70 are contemplated such as suspending the optical sensor 100 from the inner surface 79 of the fuel supply passage 70 by a tie or bracket, or rigidly suspending the optical sensor 100 within the fuel supply passage 70 (e.g., within a rigid conduit) without any additional supporting structure. The optical sensor 100 can extend along the fuel supply passage centerline 78, offset from the fuel supply passage centerline 78, or a combination thereof.

Regarding FIGS. 1-4, during operation of the turbine engine 10, the controller 60 is in communication with the fuel supply valve 36 and configured to actuate the fuel supply valve 36 between an opened position such that fuel F flows from the fuel supply 34 through the fuel nozzle assembly 48 to the combustion chamber 50 and a closed position such that fuel F does not flow from the fuel supply 34 to the fuel nozzle assembly 48. The controller 60 is also in communication with the air supply (e.g., the compressor section 12) such that air A can flow through the air supply passage 74 to the combustion chamber 50. The flow of fuel F and air A results in a mixture of fuel F and air A in the combustion chamber 50. Lightoff begins when the mixture of fuel F and air A is ignited by the igniter 90, generating the combustion flame 92. Using hydrogen-based fuel requires a high level of control over fuel flow. Effectively controlling fuel flow can include, for example, adjusting the flow of fuel F based on a signal sent by the optical sensor 100 confirming lightoff in the combustion chamber 50.

FIG. 5 is a block diagram illustrating a method 200 of operating the turbine engine 10 including the controller 60 that is in communication with the optical sensor 100. The method 200 can be utilized with the turbine engine 10 and components thereof, such as aspects illustrated in FIGS. 1-4.

The method 200 can include providing rotation to at least a portion of the turbine engine 10 (block 201), providing a flow of fuel F to the turbine engine (block 202), preparing to receive a signal generated by the optical sensor 100 (block 203), comparing the signal with a predetermined threshold value (block 204), and adjusting the flow of fuel F (block 205).

While block 203 is shown after blocks 201 and 202, the method 200 does not require that these blocks occur in succession. That is, blocks 201, 202, and 203 can occur simultaneously or successively in the order depicted or another order. While block 204 is shown after block 203, the method 200 can proceed from block 203 to block 205 without conducting block 204 (e.g. when no signal is received during block 203, the controller 60 can proceed directly to block 205 to shut off the flow of fuel F).

The method 200 can be implemented, at least in part, by the controller 60. That is, an amount of fuel provided to the fuel supply passage 70 is determined at least in part by the controller 60 receiving a signal from the optical sensor 100. The optical sensor 100 can generate and initiate transmission of a stable signal indicative of lightoff to the controller 60 within, for example, 10 ms of the optical sensor 100 receiving an input from an EM wave in the detectable region 102. The controller 60 can receive the signal and adjust the amount of fuel F provided to the fuel supply passage within, for example, 100 ms of the optical sensor 100 receiving the EM wave input indicative of lightoff.

By way of example, during the method 200, as the turbine engine 10 begins rotation (block 201) and the flow of fuel F to the turbine engine 10 begins (block 202), an exciter of the igniter 90 of each combustor portion 31 is provided a current for a step-up voltage circuit that is intended to generate high voltage that results in a spark or sparking, marking the beginning of a lightoff attempt. The controller 60 prepares to receive a signal from the optical sensor 100 detecting lightoff for a predetermined maximum length of detection time, hereinafter T_max, such as 100 ms (block 203). The value of T_max can be set based on combustor design and a length of time required to stabilize a combustion flame 92.

At block 204, the threshold value can be a value indicative of a stable combustion flame 92, and is dependent on the design of the system. For example, in configurations where a photodiode is part of the optical sensor 200, the threshold value is set to identify when the photodiode toggles between on and off.

At block 205, adjusting the flow of fuel F can include, for example, actuating the fuel supply valve 36 between an open position and a closed position to continue, adjust, or stop providing fuel F to the fuel nozzle assembly 48. However, the controller 60 can control the fuel supply 34, the fuel nozzle assembly 48, the fuel supply valve 36, or a combination thereof, to selectively provide fuel F (e.g. gaseous hydrogen fuel) to the fuel supply passage 70. If a lightoff attempt is considered confirmed (e.g., the signal from the optical sensor 100 is above a predetermined threshold within T_max), adjusting the flow of fuel F can include continuing the flow of fuel F. If a lightoff attempt is considered unconfirmed (e.g., the signal from the optical sensor 100 is below a predetermined threshold during T_max or no signal is received), adjusting the flow of fuel F can include stopping the flow of fuel F.

More specifically by way of example, the method 200 can include requiring confirmation of ignition of a combustion flame 92 in each of a critical subset of the set of combustor portions 31 within T_max for a lightoff attempt to be considered confirmed. That is, for a lightoff attempt to be considered confirmed and for the flow of fuel F to continue, the controller 60 must receive a signal from each optical sensor observing a critical combustor portion 31 that meets the predetermined threshold value within T_max. If any optical sensor 100 does not send a signal within T_max at block 203, the lightoff attempt is considered unconfirmed or no lightoff, and adjusting the flow of fuel F at block 205 can include stopping the flow of fuel F. If any optical sensor 100 sends a signal within T_max at block 203 that does not meet the threshold value at block 204, the lightoff attempt is considered unconfirmed or no lightoff and adjusting the flow of fuel F at block 205 can include stopping the flow of fuel F and exhausting any remaining fuel F and air A from the turbine engine.

In a different non-limiting example, the method 200 can include initially requiring confirmation of ignition of a combustion flame 92 in some of a non-critical subset of the set of combustor portions 31 within T_max and subsequently requiring confirmation of ignition of a combustion flame 92 in all of the non-critical subset of the set of combustor portions 31 within an additional time frame, hereinafter T_additional beyond T_max for a lightoff attempt to be considered confirmed. That is, for a lightoff attempt to be considered confirmed and for the flow of fuel F to continue, the controller 60 must receive a signal from each optical sensor observing a non-critical combustor portion 31 that meets the predetermined threshold value either initially within T_max or subsequently within T_additional. If any optical sensor 100 does not send a signal within T_max or within T_additional at block 203, the lightoff attempt is considered unconfirmed or no lightoff, and adjusting the flow of fuel F at block 205 can include stopping the flow of fuel F. If any optical sensor 100 sends a signal within T_max or within T_additional at block 203 that does not meet the threshold value at block 204, the lightoff attempt is considered unconfirmed or no lightoff and adjusting the flow of fuel F at block 205 can include stopping the flow of fuel F and exhausting any remaining fuel F and air A from the turbine engine 10.

The critical subset and the non-critical subset of the set of combustor portions 31 can each include one combustor portion 31, more than one but less than all of the set of combustor portions 31, or all of the combustor portions 31. Any combustor portion 31 that is not part of the critical subset or the non-critical subset of the set of combustor portions 31 is not connected to a fuel nozzle assembly 48 including an optical sensor 100 as described herein. That is, a combustor portion 31 that is not part of the critical subset or the non-critical subset of the set of combustor portions 31 is not observed by an optical sensor 100.

For example, the critical subset or the non-critical subset of the set of combustor portions 31 can include only a combustor portion 31 that is closest to the fuel supply 34 because detecting a flame in this combustor portion 31 can be indicative that fuel F has successfully reached a combustion chamber 50. In another example, the critical subset or the non-critical subset of combustor portions 31 can include only a combustor portion 31 that is closest to the fuel supply 34 and a combustor portion 31 that is furthest from the fuel supply 34 because detecting a flame in these two combustor portions 31 can be representative of flame propagation throughout the whole set of combustor portions 31. In yet another example, the critical subset or the non-critical subset of the set of combustor portions 31 can include all of the set of combustor portions 31.

In configurations where the fuel nozzle assembly 48 is a plurality of fuel nozzle assemblies 48 and more than one of the set of combustor portions 31 is connected to a respective fuel nozzle assembly 48 as described herein, the controller 60 can be adaptive to propagation speed. Since each optical sensor 100 sends a signal within, for example, 10 ms of a combustion flame 92 being generated in a respective combustor portion 31, the controller 60 can calculate a length of time between the controller's receipt of each signal, which can be used to determine propagation speed throughout the set of combustor portions 31. Based on the propagation speed, the controller 60 can be adaptable over time to better select an initial fuel flow rate in subsequent lightoff attempts. For example, if propagation speed is relatively slow in an initial unconfirmed lightoff attempt, the initial fuel flow rate in a subsequent lightoff attempt can be increased to lower the likelihood of another unconfirmed lightoff attempt.

To the extent not already described, the different features and structures of the various embodiments can be used in combination, or in substitution with each other as desired. That one feature is not illustrated in all of the embodiments is not meant to be construed that it cannot be so illustrated but is done for brevity of description. Thus, the various features of the different embodiments can be mixed and matched as desired to form new embodiments, whether or not the new embodiments are expressly described. All combinations or permutations of features described herein are covered by this disclosure.

This written description uses examples to describe aspects of the disclosure described herein, including the best mode, and also to enable any person skilled in the art to practice aspects of the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of aspects of the disclosure is defined by the claims, and can include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Further aspects are provided by the subject matter of the following clauses:

A turbine engine, comprising a compressor section, a combustion section, and a turbine section in a serial flow arrangement along an engine centerline, with the combustion section comprising a combustion chamber, a fuel nozzle assembly comprising a fuel supply passage defining a fuel supply passage centerline, and having a fuel supply passage outlet fluidly coupled to a combustion chamber, and an optical sensor located in the fuel supply passage and oriented to sense a combustion flame in the combustion chamber.

The turbine engine of any preceding clause, wherein the fuel nozzle assembly is a gaseous fuel nozzle assembly.

The turbine engine of any preceding clause, wherein the gaseous fuel nozzle assembly is a hydrogen fuel nozzle assembly.

The turbine engine of any preceding clause, wherein a fuel circumscribes the optical sensor and a temperature of the fuel is 400° F. (204° C.) or less.

The turbine engine of any preceding clause, wherein the fuel is transparent or translucent.

The turbine engine of any preceding clause, wherein the optical sensor is configured to transmit an electromagnetic wave having a wavelength from 200 nanometers to 1100 nanometers.

The turbine engine of any preceding clause, wherein the optical sensor includes a fiber optic cable and a photodetector.

The turbine engine of any preceding clause, wherein the optical sensor includes a signal multiplier, an amplification device, or a combination thereof.

The turbine engine of any preceding clause, wherein the optical sensor comprises silicon (Si), germanium (Ge), silicon carbide (SiC), indium gallium arsenide (InGaAs), gallium arsenide (GaAs), or a combination thereof.

The turbine engine of any preceding clause, further comprising a controller, wherein the optical sensor generates a signal within 10 milliseconds of the optical sensor receiving an input of an electromagnetic wave.

The turbine engine of any preceding clause, wherein an amount of fuel provided to the fuel supply passage is determined at least in part by the controller receiving the signal within 100 milliseconds of the optical sensor receiving an input of an electromagnetic wave.

The turbine engine of any preceding clause, wherein the optical sensor is configured to detect a flame within a detectable region of the combustion chamber.

The turbine engine of any preceding clause, wherein the fuel supply passage outlet defines an outlet centerline, and the detectable region is in a range of 70° to 110° with respect to the outlet centerline.

The turbine engine of any preceding clause, wherein the optical sensor extends along the fuel supply passage centerline, offset from the fuel supply passage centerline, or a combination thereof.

The turbine engine of any preceding clause, wherein the fuel nozzle assembly further comprises a set of fixture plates having a plurality of fixture holes disposed in an interior of the fuel supply passage.

The turbine engine of any preceding clause, wherein the set of fixture plates includes a single fixture plate.

The turbine engine of any preceding clause, wherein the set of fixture plates includes a plurality of fixture plates.

The turbine engine of any preceding clause, wherein the optical sensor passes through at least one of the plurality of fixture holes.

The turbine engine of any preceding clause, wherein the fixture holes are each a polygonal shape, an elliptical shape, a circular shape, or any combination thereof.

The turbine engine of any preceding clause, wherein the optical sensor has a sensor diameter, the at least one of the plurality of fixture holes has an aperture diameter, and the sensor diameter is less than the aperture diameter.

The turbine engine of any preceding clause, wherein the sensor diameter is in a range from 30 μm to 10 mm and the aperture diameter is in a range from 0.2 mm to 4 mm.

The turbine engine of any preceding clause, wherein a downstream terminal end of the optical sensor is disposed a distance less than 20 millimeters from the fuel supply passage outlet.

The turbine engine of any preceding clause, wherein a downstream terminal end of the optical sensor is located upstream of the fuel supply passage outlet a distance in a range of 50% to 500% of a diameter of the fuel supply passage measured at the fuel supply passage outlet.

The turbine engine of any preceding clause, wherein the fuel nozzle assembly is a plurality of fuel nozzle assemblies circumferentially spaced about the engine centerline, and the optical sensor is a plurality of optical sensors.

The turbine engine of any preceding clause, wherein each optical sensor of the plurality of optical sensors extends through a portion of a respective fuel supply passage to a portion of a respective fuel nozzle assembly upstream of a respective fuel supply passage outlet.

The turbine engine of any preceding clause, further comprising a controller, a fuel supply, and a fuel supply valve fluidly coupling the fuel nozzle assembly with the fuel supply, wherein the controller is in communication with the fuel supply valve and the optical sensor.

The turbine engine of any preceding clause, wherein the optical sensor has a non-destructive operational temperature greater than 250° F.

A method of operating a turbine engine using an optical sensor, the method including the steps of (a) providing rotation to at least a portion of the turbine engine, (b) providing a flow of fuel to the turbine engine, (c) preparing to receive a signal generated by the optical sensor for a predetermined length of time, (d) making a comparison between the signal and a predetermined threshold value, and (e) adjusting the flow of fuel based on the comparison, wherein if no signal is detected at step (c), adjusting the flow of fuel comprises stopping the flow of fuel, wherein if a signal is detected at step (c) and the signal is below the threshold value, adjusting the flow of fuel comprises stopping the flow of fuel and exhausting any remaining fuel in the turbine engine, wherein if a signal is detected at step (c) and the signal is equal to or greater than the threshold, adjusting the flow of fuel comprises continuing the flow of fuel.

A method of operating a turbine engine using a plurality of optical sensors, each optical sensor located in one of a plurality of critical combustor portions, the method including the steps of (a) providing rotation to at least a portion of the turbine engine, (b) providing a flow of fuel to the turbine engine, (c) preparing to receive a plurality of signals each generated by one of the plurality of optical sensors for a predetermined length of time T_max, (d) making a plurality of comparisons each between one of the plurality of signals and a predetermined threshold value, and (e) adjusting the flow of fuel based on the plurality of comparisons, wherein if any of the plurality of optical sensors do not generate a signal at step (c), adjusting the flow of fuel comprises stopping the flow of fuel, wherein if any signal is detected at step (c) that is below the threshold value, adjusting the flow of fuel comprises stopping the flow of fuel and exhausting any remaining fuel in the turbine engine, wherein if each of the plurality of signals detected at step (c) is equal to or greater than the threshold, adjusting the flow of fuel comprises continuing the flow of fuel.

A method of operating a turbine engine using a plurality of optical sensors, each optical sensor located in one of a plurality of non-critical combustor portions, the method including the steps of (a) providing rotation to at least a portion of the turbine engine, (b) providing a flow of fuel to the turbine engine, (c) preparing to receive a plurality of signals each generated by one of the plurality of optical sensors for a predetermined length of time T_max or subsequently within an additional pre-determined length of time T_additional, (d) making a plurality of comparisons each between one of the plurality of signals and a predetermined threshold value, and (e) adjusting the flow of fuel based on the plurality of comparisons, wherein if less than all of the plurality of optical sensors generate a signal within T_max at step (c) that is equal to or greater than the threshold, step (c) proceeds for an additional predetermined length of time T_additional, and if any of the plurality of optical sensors do not generate a signal within T_max or T_additional at step (c), adjusting the flow of fuel comprises stopping the flow of fuel, wherein if any signal is detected at step (c) that is below the threshold value, adjusting the flow of fuel comprises stopping the flow of fuel and exhausting any remaining fuel in the turbine engine, wherein if each of the plurality of signals detected at step (c) is equal to or greater than the threshold, adjusting the flow of fuel comprises continuing the flow of fuel.

A method of operating a turbine engine using a plurality of optical sensors of any preceding clause wherein one of the plurality of optical sensors is located in a combustor portion that is closest to a fuel supply.