Turbine engine comprising a steam system

Abstract

A turbine engine for an aircraft includes a turbocharged engine having a core air flow path, a fan having a fan shaft coupled to the turbocharged engine to rotate the fan shaft, and a steam system. A combustor is positioned in the core air flow path to combust a fuel and produce a combustion gas. A steam system is fluidly coupled to the core air flow path to provide steam to the core air flow path. The steam system comprises a boiler generating steam, a water pump and a controller. A water pump is in fluid communication with the boiler for directing water flow into the boiler. A controller is operably coupled to the water pump to control an output of the water pump, a flow of water into the boiler, and an amount of steam injected into the core air flow path.

Description

Technical Field

[0001] The present disclosure generally relates to turbine engines including steam systems. Background Art

[0002] Turbine engines used in aircraft generally include a fan and a core section arranged in flow communication with each other. A combustor is arranged in the core section to generate combustion gases for driving a turbine in the core section of the turbine engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Features and advantages of the present disclosure will be apparent from the following description of various exemplary embodiments as illustrated in the drawings, wherein like reference numbers generally indicate identical, functionally similar, and / or structurally similar elements.

[0004] Figure 1 is a schematic cross-sectional view of a turbine engine including a steam system according to the present disclosure, taken along a longitudinal centerline axis of the turbine engine.

[0005] Figure 2 According to the present disclosure Figure 1 Schematic diagram of the turbine engine and steam system.

[0006] Figure 3 is a schematic diagram of a turbine engine and steam system according to an embodiment of the present disclosure.

[0007] Figure 4 It shows the control Figure 3 A flow chart of a method for a steam system is shown in FIG. DETAILED DESCRIPTION

[0008] Features, advantages and embodiments of the present disclosure are set forth or apparent through consideration of the following detailed description, drawings and claims.In addition, the following detailed description is exemplary and is intended to provide further explanation without limiting the scope of the present disclosure as claimed.

[0009] Various embodiments are discussed in detail below. Although specific embodiments are discussed, this is for illustrative purposes only. Those skilled in the relevant art will recognize that other components and configurations may be used without departing from the spirit and scope of the present disclosure.

[0010] As used herein, the terms "first," "second," and the like may be used interchangeably to distinguish one component from another, and are not intended to indicate the position or importance of each component.

[0011] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle and refer to the normal operating attitude of the gas turbine engine or vehicle. For example, for a gas turbine engine, front refers to a position closer to the engine inlet, while rear refers to a position closer to the engine nozzle or exhaust.

[0012] The terms "upstream" and "downstream" refer to relative directions with respect to the flow of a fluid in a fluid path. For example, "upstream" refers to the direction from which the fluid is flowing, and "downstream" refers to the direction to which the fluid is flowing.

[0013] The terms “coupled,” “fixed,” “attached,” “connected,” and the like refer to both direct coupling, fixing, attachment, or connection as well as indirect coupling, fixing, attachment, or connection through one or more intermediate components or features, unless otherwise specified herein.

[0014] As used herein, the terms "axial" and "axially" refer to directions and orientations extending substantially parallel to the centerline of the turbine engine. Additionally, the terms "radial" and "radially" refer to directions and orientations extending substantially perpendicular to the centerline of the turbine engine. Additionally, as used herein, the terms "circumferential" and "circumferentially" refer to directions and orientations extending in an arc around the centerline of the turbine engine.

[0015] When discussed in the context of radial directions, references to "inner" and "outer" refer to positions relative to the longitudinal centerline of the component.

[0016] As used herein, a "bypass ratio" of a turbine engine is the ratio of bypass air passing through a bypass of the turbine engine to core air passing through a core inlet of a turbo-engine of the turbine engine.

[0017] As used herein, the "compression ratio" of a compressor is the ratio of the compressor outlet pressure at the outlet of the compressor to the compressor inlet pressure at the inlet of the compressor. The compressor outlet pressure and the compressor inlet pressure are measured as static air pressures perpendicular to the direction of core air flow through the compressor.

[0018] As used herein, the "pressure expansion ratio" of a turbine is the ratio of the pressure at the inlet of the turbine to the pressure at the outlet of the turbine.

[0019] As used herein, a "core air flow path zone" is a portion (i.e., area or region) of a core air flow path where the core air flowing through the core air flow path has different or distinct thermodynamic properties than surrounding or adjacent areas of the core air flow path.

[0020] As used herein, the terms "low," "medium" (or "medium level"), and "high," or their respective comparatives (e.g., "lower" and "higher," where applicable), when used with a compressor, turbine, shaft, fan, or turbine engine component, refer to relative pressures, relative speeds, relative temperatures, and / or relative power outputs within an engine, unless otherwise specified. For example, a "low power" setting defines an engine configured to operate at a power output lower than a "high power" setting for the engine, while a "medium level power" setting defines an engine configured to operate at a power output higher than the "low power" setting and lower than the "high power" setting. The terms "low," "medium" (or "medium level"), or "high" in the above terms may additionally or alternatively be understood as relative to a minimum allowable speed, pressure, or temperature, or relative to a minimum or maximum allowable speed, pressure, or temperature for normal, desired, steady state, etc., operation of the engine.

[0021] The various power levels of the turbine engine described in detail herein are defined as percentages of the maximum engine rated thrust at sea level static (SLS). Low power operation includes, for example, less than thirty percent (30%) of the SLS maximum engine rated thrust of the turbine engine. Medium level power operation includes, for example, thirty percent (30%) to eighty-five percent (85%) of the SLS maximum engine rated thrust of the turbine engine. High power operation includes, for example, greater than eighty-five percent (85%) of the SLS maximum engine rated thrust of the turbine engine. The thrust values ​​for each of the low power operation, medium level power operation, and high power operation of the turbine engine are exemplary only, and other thrust values ​​can be used to define low power operation, medium level power operation, and high power operation.

[0022] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0023] Here and throughout the specification and claims, range limitations are combined and interchanged. Unless the context or language indicates otherwise, these ranges are identified and include all subranges contained therein. For example, all ranges disclosed herein include the endpoints, and the endpoints can be combined independently of each other.

[0024] As mentioned above, the burner is arranged in the core section of the turbine engine to produce combustion gases for driving the turbine in the core section. The energy and heat generated by the burner are not all used to drive the turbine of the turbine section. On the contrary, some waste heat is discharged through the jet exhaust nozzle section in the traditional turbine engine. The turbine engine discussed in this article includes a steam system, which is used to recover some energy from waste heat by generating steam and driving a steam turbine. After flowing through the steam turbine, the steam can be injected into the core air flow path. The required amount of steam can vary based on the operating conditions (such as power level) of the turbine engine, and the amount of steam injected into the core air flow path by the steam system can be controlled based on the operating conditions of the turbine engine. As discussed in this article, the steam injected into the core air flow path can be controlled by controlling a water pump, which guides the water flow to the boiler that produces steam.

[0025] Now referring to the accompanying drawings, Figure 1 is a schematic cross-sectional view of a turbine engine 10 including a steam system 100 taken along a longitudinal centerline axis 12 (provided for reference) of the turbine engine 10 in accordance with an embodiment of the present disclosure. Figure 1 As shown, the turbine engine 10 has an axial direction A (extending parallel to the longitudinal centerline axis 12 ) and a radial direction R orthogonal to the axial direction A. Generally, the turbine engine 10 includes a fan section 14 and a turbocharger engine 16 disposed downstream of the fan section 14 .

[0026] The turbocharger engine 16 includes an outer casing 18 that is substantially tubular and defines an annular core inlet 20. Figure 1 As schematically shown in FIG. 1 , outer casing 18 encloses, in series flow relationship, a compressor section 21 including a supercharger or low pressure compressor (LPC) 22 followed downstream by a high pressure compressor (HPC) 24; a combustor 26; a turbine section 27 including a high pressure turbine (HPT) 28 followed downstream by a low pressure turbine (LPT) 30; and one or more core exhaust nozzles 32. A high pressure (HP) shaft 34 or spool drivingly connects the HPT 28 to the HPC 24 so that the HPT 28 and the HPC 24 rotate in unison. The HPT 28 is drivingly coupled to the HP shaft 34 so that the HP shaft 34 rotates when the HPT 28 rotates. A low pressure (LP) shaft 36 drivingly connects the LPT 30 to the LPC 22 so that the LPT 30 and the LPC 22 rotate in unison. LPT 30 is drivingly coupled to LP shaft 36 to rotate LP shaft 36 when LPT 30 rotates. Compressor section 21 , combustor 26 , turbine section 27 , and one or more core exhaust nozzles 32 together define a core air flow path 33 .

[0027] for Figure 1 In the embodiment shown in FIG. 1 , the fan section 14 includes a fan 38 (eg, a variable pitch fan) having a plurality of fan blades 40 coupled to a disk 42 in a spaced-apart manner. Figure 1 As shown, fan blades 40 generally extend outwardly from disk 42 in a radial direction R. Each fan blade 40 is rotatable relative to disk 42 about pitch axis P by virtue of fan blades 40 being operably coupled to actuator 44, which is configured to collectively and in unison change the pitch of fan blades 40. Fan blades 40, disk 42, and actuator 44 together are rotatable about longitudinal centerline axis 12 via fan shaft 45, which is powered by LP shaft 36 across a power gearbox (also referred to as gearbox assembly 46). Gearbox assembly 46 is Figure 1 The gearbox assembly 46 includes a plurality of gears for adjusting the rotational speed of the fan shaft 45 , thereby adjusting the rotational speed of the fan 38 relative to the LP shaft 36 .

[0028] Still reference Figure 1 In an exemplary embodiment of the present invention, the disk 42 is covered by a rotatable fan hub 48 having an aerodynamic profile to facilitate airflow through the plurality of fan blades 40. In addition, the fan section 14 includes an annular fan casing or nacelle 50 that circumferentially surrounds the fan 38 and / or at least a portion of the turbocharger engine 16. The nacelle 50 is supported relative to the turbocharger engine 16 by a plurality of circumferentially spaced outlet guide vanes 52. In addition, a downstream section 54 of the nacelle 50 extends over an outer portion of the turbocharger engine 16 to define a bypass airflow channel 56 therebetween. One or more core exhaust nozzles 32 may extend through the nacelle 50 and be formed therein. In this embodiment, the one or more core exhaust nozzles 32 include one or more discrete nozzles that are circumferentially spaced around the nacelle 50. Other arrangements of the core exhaust nozzles 32 may also be employed, such as a single core exhaust nozzle that includes an annular or partially annular core exhaust nozzle around the nacelle 50.

[0029] During operation of the turbine engine 10, a volume of air 58 enters the turbine engine 10 through the nacelle 50 and / or the inlet 60 of the fan section 14. As the volume of air 58 passes through the fan blades 40, a first portion of the air (bypass air 62) is directed or directed into the bypass airflow passage 56, while a second portion of the air (core air 64) is directed or directed into the upstream section of the core air flow path 33, or more specifically, directed or directed into the core inlet 20. The ratio between the first portion of the air (bypass air 62) and the second portion of the air (core air 64) is generally referred to as the bypass ratio. In some embodiments, the bypass ratio is greater than 18:1, which is achieved by the steam system 100, which will be further described below. The LPC 22 then increases the pressure of the core air 64 to produce compressed air 65, and the compressed air 65 is directed through the HPC 24 and further compressed, and then directed into the combustor 26, where the compressed air 65 is mixed with the fuel 67 and combusted to produce combustion gases 66 (combustion products). One or more stages may be used in each of the LPC 22 and the HPC 24, where each subsequent stage further compresses the compressed air 65. The compression ratio of the HPC 24 is greater than 20:1, for example, in the range of 20:1 to 40:1. The compression ratio is the ratio of the pressure of the last stage of the HPC 24 to the pressure of the first stage of the HPC 24. The steam system 100 can achieve a compression ratio greater than 20:1, as described in further detail below.

[0030] The combustion gases 66 are directed into and expanded through the HPT 28, wherein a portion of the thermal and / or kinetic energy from the combustion gases 66 is extracted via sequential stages of HPT stator blades 68 coupled to the outer casing 18 and HPT rotor blades 70 coupled to the HP shaft 34, thereby causing the HP shaft 34 to rotate, thereby supporting the operation of the HPC 24. The combustion gases 66 are then directed into and expanded through the LPT 30. Here, a second portion of the thermal and / or kinetic energy is extracted from the combustion gases 66 via sequential stages of LPT stator blades 72 coupled to the outer casing 18 and LPT rotor blades 74 coupled to the LP shaft 36, thereby causing the LP shaft 36 to rotate, thereby supporting the operation of the LPC 22 and supporting the rotation of the fan 38 via the gearbox assembly 46. One or more stages may be used in each of the HPT 28 and the LPT 30. The compression ratio of the HPC 24 is in the range of 20:1 to 40:1, which results in a pressure expansion ratio of the HPT 28 in the range of 1.5:1 to 4:1, and a pressure expansion ratio of the LPT 30 in the range of 4.5:1 to 28:1.

[0031] The combustion gases 66, after being directed through the steam system 100 (discussed below), are then directed through one or more core exhaust nozzles 32 of the turbocharger engine 16 to provide propulsive thrust. While the core air 64 flows through the core air flow path 33, the bypass air 62 is directed through the bypass airflow passage 56 and then discharged from the fan bypass nozzle 76 of the turbine engine 10, also providing propulsive thrust. The HPT 28, the LPT 30, and the one or more core exhaust nozzles 32 at least partially define a hot gas path 78 for directing the combustion gases 66 through the turbocharger engine 16.

[0032] As described above, compressed air 65 (core air 64) is mixed with fuel 67 in combustor 26 to form a fuel and air mixture and combusted to produce combustion gases 66 (combustion products). Fuel 67 may include any type of fuel for turbine engines, such as sustainable aviation fuel (SAF), including biofuel, JetA or other hydrocarbon fuels. Fuel 67 may also be a hydrogen-based fuel (H 2 ), although hydrogen-based fuels may include mixtures with hydrocarbon fuels, the fuel 67 used herein is unmixed and is referred to herein as hydrogen fuel. In some embodiments, the hydrogen fuel may include substantially pure hydrogen molecules (i.e., diatomic hydrogen). The fuel 67 may also be a cryogenic fuel. For example, when hydrogen fuel is used, the hydrogen fuel may be stored in a liquid phase at low temperatures.

[0033] Turbine engine 10 includes a fuel system 80 for providing fuel 67 to combustor 26. Fuel system 80 includes a fuel tank 82 for storing fuel 67 therein and a fuel delivery assembly 84. Fuel tank 82 may be located on an aircraft (not shown) to which turbine engine 10 is attached. Figure 1 8, but the fuel system 80 may include any number of fuel tanks 82 as desired. The fuel delivery assembly 84 delivers the fuel 67 from the fuel tank 82 to the combustor 26. The fuel delivery assembly 84 includes one or more lines, conduits, pipes, tubes, etc., which are configured to deliver the fuel 67 from the fuel tank 82 to the combustor 26. The fuel delivery assembly 84 also includes a pump 86 to direct the flow of the fuel 67 through the fuel delivery assembly 84 to the combustor 26. In this way, the pump 86 pumps the fuel 67 from the fuel tank 82 through the fuel delivery assembly 84 and into the combustor 26. The fuel system 80, and more specifically, the fuel tank 82 and the fuel delivery assembly 84, whether together or separately, can be a fuel source for the combustor 26.

[0034] In some embodiments, for example, when the fuel 67 is a hydrogen fuel, the fuel system 80 includes one or more vaporizers 88 (illustrated by dashed lines) and a metering valve 90 (illustrated by dashed lines) in fluid communication with the fuel delivery assembly 84. In this example, the hydrogen fuel is stored in the fuel tank 82 as a liquid hydrogen fuel. The one or more vaporizers 88 heat the liquid hydrogen fuel flowing through the fuel delivery assembly 84. The one or more vaporizers 88 are positioned in the flow path of the fuel 67 between the fuel tank 82 and the combustor 26, and are located downstream of the pump 86. The one or more vaporizers 88 are thermally connected to at least one heat source, such as waste heat from the turbine engine 10 and / or from one or more systems of the aircraft (not shown). The one or more vaporizers 88 heat the liquid hydrogen fuel, and the liquid hydrogen fuel is converted into gaseous hydrogen fuel in the one or more vaporizers 88. The fuel delivery assembly 84 guides the gaseous hydrogen fuel to the combustor 26.

[0035] A metering valve 90 is positioned downstream of the one or more vaporizers 88 and the pump 86. The metering valve 90 receives the hydrogen fuel in a substantially complete gas phase or in a substantially complete supercritical phase. The metering valve 90 provides a fuel flow to the burner 26 in a desired manner. More specifically, the metering valve 90 provides a desired volume of hydrogen fuel at, for example, a desired flow rate to a fuel manifold that includes one or more fuel injectors that inject the hydrogen fuel into the burner 26. The fuel system 80 may include any components for supplying the fuel 67 from the fuel tank 82 to the burner 26 as needed.

[0036] Turbine engine 10 includes a steam system 100 in fluid communication with one or more core exhaust nozzles 32 and fan bypass nozzles 76. Steam system 100 extracts steam from combustion gases 66 as they flow through steam system 100, as described in further detail below.

[0037] Figure 1 The turbine engine 10 depicted in the drawings is for example only. In other exemplary embodiments, the turbine engine 10 may have any other suitable configuration. For example, in other exemplary embodiments, the fan 38 may be configured in any other suitable manner (e.g., as a fixed pitch fan) and may also be supported using any other suitable fan frame configuration. In addition, in other exemplary embodiments, any other suitable number or configuration of compressors, turbines, shafts, or combinations thereof may be provided. In other exemplary embodiments, aspects of the present disclosure may be incorporated into any other suitable turbine engine, such as a turbofan engine, a propfan engine, and / or a turboprop engine.

[0038] Figure 21 is a schematic diagram of a turbine engine 10 having a steam system 100a according to an embodiment of the present disclosure. For clarity of other steam systems discussed herein, the steam system 100a of this embodiment will be referred to as the first steam system 100a. The first steam system 100a can be used as Figure 1 1. The steam system 100 in the turbine engine 10 is shown in FIG. 1. For clarity, Figure 2 Various features of the turbine engine 10 described and illustrated above are schematically illustrated in FIG. Figure 2 Some components are not shown in FIG. 1 , but the description of these components also applies here. The first steam system 100 a includes a boiler 102 , a condenser 104 , a water separator 106 , a water pump 108 , and a steam turbine 110 .

[0039] The boiler 102 is a heat exchanger that vaporizes liquid water from a water source to produce steam or water vapor, as described in further detail below. Thus, the boiler 102 is a steam source. In particular, the boiler 102 is an exhaust gas-water heat exchanger. The boiler 102 is connected to the hot gas path 78 ( Figure 1 ) and is positioned downstream of the LPT 30. The boiler 102 is also in fluid communication with a water pump 108, as described in further detail below. The boiler 102 may include any type of boiler or heat exchanger for extracting heat from the combustion gases 66 and vaporizing the liquid water into steam or water vapor as the liquid water and the combustion gases 66 flow through the boiler 102.

[0040] The condenser 104 is a heat exchanger that further cools the combustion gases 66 as they flow through the condenser 104, as described in further detail below. In particular, the condenser 104 is an air-exhaust gas heat exchanger. The condenser 104 is in fluid communication with the boiler 102 and is positioned within the bypass air flow passage 56. The condenser 104 may include any type of condenser for condensing water (e.g., in liquid form) from the exhaust (e.g., the combustion gases 66).

[0041] The water separator 106 is in fluid communication with the condenser 104 for receiving the cooled exhaust gas (combustion gases 66) having condensed water entrained therein. The water separator 106 is also in fluid communication with one or more core exhaust nozzles 32 and with a water pump 108. The water separator 106 includes any type of water separator for separating water from the exhaust gas. For example, the water separator 106 may include a cyclone separator that uses vortex separation to separate water from air. In such an embodiment, the water separator 106 generates a cyclonic flow within the water separator 106 to separate water from the cooled exhaust gas. Figure 2, the water separator 106 is schematically depicted as being located in the nacelle 50, but the water separator 106 may be located elsewhere within the turbine engine 10, for example, radially inward of the nacelle 50, closer to the turbocharger engine 16. The water separator 106 may be driven to rotate by one of the engine shafts (e.g., the HP shaft 34 or the LP shaft 36). As described above, the boiler 102 receives liquid water from a water source to generate steam or water vapor. Figure 2 In the embodiment shown in , the condenser 104 and the water separator 106 , either individually or collectively, are the source of water for the boiler 102 .

[0042] The water pump 108 is in fluid communication with the water separator 106 and with the boiler 102. The water pump 108 is in fluid communication with the condenser 104 via the water separator 106. The water pump 108 can be any suitable pump, such as a centrifugal pump or a positive displacement pump. The water pump 108 directs the separated liquid water 124 through the boiler 102, where the water 124 is converted back into steam. The steam is transported through the steam turbine 110 and then injected into the core air flow path 33, such as into the combustor 26.

[0043] In operation, combustion gases 66 (also referred to as exhaust) flow from the LPT 30 into the boiler 102. The combustion gases 66 transfer heat to water 124 (e.g., in liquid form) within the boiler 102, as described in further detail below. The combustion gases 66 then flow into the condenser 104. The condenser 104 condenses the water 124 (e.g., in liquid form) from the combustion gases 66. The bypass air 62 flows through the bypass airflow passage 56 and flows through or through the condenser 104, and extracts heat from the combustion gases 66, cools the combustion gases 66 and condenses the water 124 from the combustion gases 66 to produce an exhaust-water mixture 120. The bypass air 62 then exits the turbine engine 10 through the fan bypass nozzle 76 to generate thrust, as described in detail above. Therefore, the condenser 104 can be positioned in the bypass airflow passage 56.

[0044] The exhaust-water mixture 120 flows into the water separator 106. The water separator 106 separates water 124 from the exhaust of the exhaust-water mixture 120 to produce separated exhaust gas 122 and water 124. The exhaust gas 122 is discharged from the turbine engine 10 through one or more core exhaust nozzles 32 to produce thrust, as described in detail above. The boiler 102, condenser 104, and water separator 106 thus also define a hot gas path 78 (see Figure 1 ) for directing the combustion gases 66, the exhaust-water mixture 120, and the exhaust gas 122 through the first steam system 100a of the turbine engine 10.

[0045] The water pump 108 passes through one or more water pipelines (such as Figure 2Water 124 (e.g., in liquid form) is pumped by a duct (as indicated by an arrow pointing to water 124) and flows through the boiler 102. As the water 124 flows through the boiler 102, the combustion gases 66 flowing through the boiler 102 transfer heat to the water 124 to vaporize the water 124 and generate steam 126 (e.g., steam). The steam turbine 110 includes one or more stages of steam turbine blades (not shown) and a steam turbine stator (not shown). The steam 126 is transferred from the boiler 102 through one or more steam lines (e.g., steam turbines). Figure 2 Steam 126 (indicated by arrows in FIG. 1 ) flows into the steam turbine 110 , causing the steam turbine blades of the steam turbine 110 to rotate, generating additional work in an output shaft (eg, one of the engine shafts) connected to the turbine blades of the steam turbine 110 .

[0046] As mentioned above, the turbocharger engine 16 includes a shaft, also referred to as an engine shaft, that couples the various rotating components of the turbocharger engine 16 and other thrust generating components such as the fan 38. Figure 1 In the turbocharger engine 16 shown in FIG. 1 , these engine shafts include an HP shaft 34 and an LP shaft 36. A steam turbine 110 is coupled to one of the engine shafts of the turbocharger engine 16, such as the HP shaft 34 or the LP shaft 36. In the illustrated embodiment, the steam turbine 110 is coupled to the LP shaft 36. As steam 126 flows from the boiler 102 through the steam turbine 110, the steam turbine 110 converts the kinetic energy of the gas into mechanical work in the LP shaft 36. The reduced temperature steam (as steam 128) leaving the steam turbine 110 is then injected into the core air flow path 33, such as into the combustor 26, upstream of the combustor 26, or downstream of the combustor 26. The steam 128 flows from the steam turbine 110 through one or more steam lines to the core air flow path 33. The steam 128 injected into the core air flow path 33 adds mass flow to the core air 64, so that less core air 64 is required to produce the same amount of work through the turbine section 27. In this way, the first steam system 100a extracts additional work from heat in the exhaust gases that would otherwise be wasted. The steam 128 injected into the core air flow path 33 is in the range of 20% to 50% of the mass flow through the core air flow path 33 .

[0047] The steam turbine 110 may have a pressure expansion ratio in the range of 2:1 to 6:1. The pressure expansion ratio is the ratio of the pressure at the inlet of the steam turbine 110 to the pressure at the outlet of the steam turbine 110. When the first steam system 100a recovers approximately 70% of the water 124 and converts the water 124 into steam 126, the steam turbine 110 may contribute approximately 25% of the power to the LP shaft 36 (or to the HP shaft 34). The pressure expansion ratio of the steam turbine 110 is in the range of 2:1 to 6:1, the pressure expansion ratio of the LPT 30 is in the range of 4.5:1 to 28:1, and the steam 128 contributes 20% to 50% of the mass flow through the core air flow path 33. The steam turbine 110 expands the steam 126, thereby reducing the energy of the steam 128 leaving the steam turbine 110, and reducing the temperature of the steam 128 to approximately 100% of the compressed air 65 exhausted from the HPC 24 (see Figure 1 ) temperature. This configuration enables the steam 128 to reduce hot spots in the combustor 26 that are created by the combustion of the fuel (e.g., particularly when the fuel is supercritical hydrogen or gaseous hydrogen).

[0048] The steam 128 injected into the core air flow path 33 also enables the HPT 28 to have a greater energy output using fewer stages of the HPT 28 as compared to an HPT without the benefit of the present disclosure. For example, the additional mass flow from the steam 128 through the turbine section 27 helps to produce a greater energy output. As such, due to the higher mass flow (created by the steam injection) exiting the combustor 26, the HPT 28 may have only one stage that is capable of sustainably driving more stages of the HPC 24 (e.g., ten, eleven, or twelve stages of the HPC 24). The steam 128 injected into the core air flow path 33 enables the HPT 28 to have only one stage that drives multiple stages of the HPC 24 without reducing the amount of work produced by the HPT 28 as compared to an HPT without the benefit of the present disclosure, while also reducing the weight of the HPT 28 and improving the efficiency of the HPT 28 as compared to an HPT without the benefit of the present disclosure.

[0049] Due to the added mass flow from steam 126, the required core air 64 (see Figure 1)Less. Compared to an HPC without the benefits of the present disclosure, the compression ratio of HPC 24 can be increased. Thus, the compression ratio of HPC 24 is greater than 20:1. In some embodiments, the compression ratio of HPC 24 is in the range of 20:1 to 40:1. Therefore, the increased compression ratio of HPC 24 increases the thermal efficiency of turbine engine 10 compared to an HPC and a turbine engine without the benefits of the present disclosure. Additionally, due to the added mass flow provided by the steam 126, 128 injected into the turbocharged engine 16, HPC 24 can have a reduced throat area. Thus, HPC 24 has a reduced size (e.g., outer diameter) and reduced weight compared to a turbine engine without the benefits of the present disclosure.

[0050] In some embodiments, at least two stages of the HPC stator vanes of HPC 24 are variable stator vanes that are controlled to pitch about a pitch axis to change the pitch of the HPC stator vanes. In some embodiments, HPC 24 includes one or more compressor bleed valves that are controlled to open to bleed off a portion of the compressed air 65 from HPC 24 (see Figure 1 ). One or more compressor bleed valves can be positioned between the fourth stage of HPC 24 and the last stage of HPC 24. The HPC stator vanes are variable stator vanes, and the one or more compressor bleed valves help balance the air flow (e.g., compressed air 65) through all stages of HPC 24. This balance, combined with the steam 128 injected into the core air flow path 33, enables the number of stages of HPC 24 to include ten to twelve stages to achieve a compression ratio greater than 20:1, e.g., in the range of 20:1 to 40:1.

[0051] The additional work extracted by the first steam system 100a and the steam 128 injected into the core air flow path 33 cause the size of the turbocharged engine 16 ( Figure 1 ) to be reduced, which increases the bypass ratio of turbine engine 10 compared to a turbine engine without the benefits of the present disclosure. Thus, the bypass ratio of turbine engine 10 is greater than 18:1, e.g., in the range of 18:1 to 100:1, in the range of 25:1 to 85:1, or in the range of 28:1 to 70:1. Thus, the first steam system 100a can achieve an increased bypass ratio compared to a turbine engine without the benefits of the present disclosure, where turbine engine 10 can move a greater mass of air through the bypass, thereby reducing the pressure ratio of the fan 38 and increasing the efficiency of turbine engine 10.

[0052] Figure 2The steam system 100 shown in [Figure] also includes a controller 150. The controller 150 can be a separate, stand-alone controller operable as described herein, or can be another controller of the turbine engine 10, such as an engine controller. The engine controller can be a full-authority digital engine control (FADEC). The controller 150 is configured to operate various aspects of the steam system 100a, including the first steam control valve 112, the second steam control valve 114, and the water pump 108 in this embodiment. In this embodiment, the controller 150 is a computing device having one or more processors 152 and one or more memories 154. The processor 152 can be any suitable processing device, including but not limited to a microprocessor, a microcontroller, an integrated circuit, a logic device, a programmable logic controller (PLC), an application specific integrated circuit (ASIC), and / or a field programmable gate array (FPGA). The memory 154 can include one or more computer-readable media, including but not limited to non-transitory computer-readable media, computer-readable non-volatile media (such as flash memory), RAM, ROM, hard disk drives, flash drives, and / or other memory devices.

[0053] The memory 154 can store information accessible by the processor 152, including computer-readable instructions that can be executed by the processor 152. The instructions can be any set of instructions or sequence of instructions that, when executed by the processor 152, cause the processor 152 and the controller 150 to perform operations. In some embodiments, the instructions can be executed by the processor 152 to cause the processor 152 to complete any operations and functions that the controller 150 is configured to perform, as will be further described below. The instructions can be software written in any suitable programming language, or can be implemented in hardware. Additionally, and / or alternatively, the instructions can be executed in logically and / or virtually independent threads on the processor 152. The memory 154 can also store data that can be accessed by the processor 152.

[0054] The techniques discussed herein relate to computer-based systems and actions taken by and information sent to and from computer-based systems. One of ordinary skill in the art will recognize that the inherent flexibility of computer-based systems allows for various possible configurations, combinations, and divisions of tasks and functions among and within components. For example, the processes discussed herein can be implemented using a single computing device or multiple computing devices working in combination. Databases, memories, instructions, and applications can be implemented on a single system or distributed across multiple systems. The distributed components can operate sequentially or in parallel.

[0055] The controller 150 may be coupled to one or more sensors 156, such as a plurality of sensors. These sensors 156 may be, for example, temperature sensors, pressure sensors, or flow sensors, such as flow meters 116, discussed further below. The sensors 156 may be positioned at various suitable locations within the turbine engine 10, including within the core air flow path 33. For example, one sensor 156 of the plurality of sensors may be positioned upstream of the combustor 26, such as at the compressor discharge outlet, in the mixing chamber, or as part of the mixer assembly 140. Another sensor 156 of the plurality of sensors may be positioned in the hot gas path 78 (i.e., the flow path of the combustion gas 66) downstream of the combustor 26, such as at the nozzle (inlet) or outlet of the HPT 28 or LPT 30. The controller 150 may receive input from one or more sensors 156 and determine the power level of the turbine engine 10 or the flow rate of the core air 64 based on the input received from the sensors 156.

[0056] As described above, the first steam system 100a includes a water pump 108, which is positioned to increase the flow rate of water 124 flowing into the boiler 102, thereby increasing the pressure of the water 124. The water pump 108 similarly provides an increase in the pressure of the steam 126 flowing into the steam turbine 110 and the pressure of the steam 128 flowing into the burner 26. The turbine engine 10 does not operate under stable operating conditions. Instead, the turbine engine 10 operates under various different operating conditions. For example, during the normal operating cycle of the aircraft, the turbine engine 10 can operate at high power (high power operation or condition) when taking off and climbing, and operate at low power (e.g., idle speed) when descending (low power operation or condition). In this context, high power and low power are relative. During flight, the turbine engine 10 can also operate under cruise, including power conditions (operations) between the high power conditions and the low power conditions discussed above. Under different operating conditions, the amount of steam injected into the burner 26 can be adjusted, for example, the amount of steam is small when the low power operation is performed, and the amount of steam is large when the high power operation is performed.

[0057] The flow of steam 128 into the core air flow path 33 may be controlled, at least in part, by one or more valves. Figure 2The first steam system 100a shown in FIG. 1 includes one or more flow control valves positioned between the boiler 102 and the combustor 26 to control the amount of steam flowing into the combustor 26. In this embodiment, the first steam control valve 112 is positioned in the flow path (e.g., pipeline) between the boiler 102 and the steam turbine 110, and the second steam control valve 114 is positioned in the flow path (e.g., pipeline) between the steam turbine 110 and the combustor 26. Therefore, the first steam control valve 112 is positioned upstream of the steam turbine 110 and downstream of the boiler 102 to control the flow of steam 126 into the steam turbine 110. Similarly, the second steam control valve 114 is positioned upstream of the combustor 26 and downstream of the steam turbine 110 to control the flow of steam 128 into the combustor 26. Any suitable flow control valve can be used as the first steam control valve 112 or the second steam control valve 114. Such a flow control valve can have a closed position and a plurality of open positions, including a fully open position. The flow control valve may be an electrically operated valve, a hydraulically operated valve, or a pneumatically operated valve. When the flow control valve is hydraulically operated, the hydraulic fluid may be a suitable fluid for the turbine engine 10, including, for example, fuel 67, lubricating oil, etc.

[0058] Various suitable water pumps can be used as the water pump 108, including variable speed water pumps. The water pump 108 can be, for example, a centrifugal pump. When the water pump 108 is a centrifugal pump, the flow rate of the steam 128 entering the combustor 26 is a function of the combustor pressure and the injector (e.g., nozzle) that injects the steam 128 into the combustor 26. The controller 150 can be communicatively and operably coupled to the second steam control valve 114 to change the position (i.e., move) of the second steam control valve 114 between a plurality of open positions and control the total flow rate of the steam 128 entering the combustor 26. When the water pump 108 is a centrifugal pump, the first steam control valve 112 can be used to control the pressure difference (pressure drop) across the steam turbine 110, and can directly control the rotation speed and other operating conditions of the steam turbine 110. Thus, this arrangement of first and second steam control valves 112 , 114 , along with water pump 108 being a centrifugal pump, may allow the pressure drop across steam turbine 110 to be controlled somewhat independently of the flow rate of steam 128 entering combustor 26 .

[0059] Alternatively, the water pump 108 may be a positive displacement pump. When the water pump 108 is a positive displacement pump, the speed of the water pump 108 and the displacement of the water pump 108 control the flow of steam 126 into the steam turbine 110 and the combustor 26. In this case, the first steam control valve 112 and / or the second steam control valve 114 may be used to control the pressure difference (pressure drop) across the steam turbine 110.

[0060] As described above, the controller 150 is communicatively and operably coupled to the first steam control valve 112 and the second steam control valve 114. The controller 150 may also be communicatively and operably coupled to the water pump 108 to control the speed and / or displacement of the water pump 108. Thus, the controller 150 may control the positions of the first steam control valve 112 and the second steam control valve 114 in response to inputs received by the controller 150 indicating changes in operating conditions of the turbine engine 10. For example, the controller 150 may receive inputs indicating changes in the throttle position or other inputs indicating changes in the amount of fuel 67 provided to the combustor 26, and the controller 150 may change the positions of the first steam control valve 112 and / or the second steam control valve 114 in response to the inputs. As described above, the controller 150 may also be coupled to sensors 156 positioned within the turbine engine 10 and / or on the aircraft. Such sensors 156 may include, for example, temperature sensors and / or pressure sensors positioned within the core air flow path 33 (e.g., the hot gas path 78). The temperature sensor and the pressure sensor are communicatively coupled to controller 150. Controller 150 is configured to receive an input from one of the temperature sensors indicating the temperature of turbine engine 10, and controller 150 is configured to receive an input from one of the pressure sensors indicating the pressure of turbine engine 10. The input received from the temperature sensor and / or the pressure sensor may be an input indicating a change in an operating condition of turbine engine 10.

[0061] As described above, the water pump 108 can be a variable speed water pump, a variable displacement water pump, or both. The controller 150 can also control the speed of the water pump 108, the displacement of the water pump 108, or both. The controller 150 is configured to change the output of the water pump 108 by, for example, changing the speed or displacement of the water pump 108. Increasing the speed or displacement of the water pump 108 will increase the mass flow rate of water output by the water pump 108, while reducing the speed or displacement of the water pump 108 will reduce the mass flow rate of water output by the water pump 108. The controller 150 can control the speed of the water pump 108, the displacement of the water pump 108, or both in response to inputs (such as the inputs discussed above) received by the controller 150 indicating changes in the operating conditions of the turbine engine 10.

[0062] The controller 150 may be configured to control the output of the water pump 108, such as the mass flow rate of the water 124 from the water pump 108, based on the current or desired operating conditions of the turbine engine 10. More specifically, the controller 150 may be configured to control the output of the water pump 108 to achieve a target mass flow rate based on the current or desired operating conditions of the turbine engine 10. The first steam system 100a may include a flow meter 116 located between the water pump 108 and the boiler 102 to measure the output of the water pump 108, such as in the flow path of the water 124 from the water pump 108 to the boiler 102. The controller 150 may be coupled to the flow meter 116 to receive input from the flow meter 116 and determine the mass flow rate of the water 124 output by the water pump 108. Based on the determined mass flow rate, the controller 150 may then be configured to control the output of the water pump 108 to achieve the target mass flow rate. Various suitable flow meters may be used as the flow meter 116, including, for example, a mass flow meter or a volume flow meter. If the flow meter 116 is a volume flow meter, the first steam system 100a may further include a temperature sensor 118 located between the water pump 108 and the boiler 102 to measure the temperature of the water 124 output from the water pump 108. The controller 150 is coupled to the temperature sensor 118 to receive input from the temperature sensor 118 and convert the volume flow measured by the flow meter 116 into a mass flow. The temperature sensor 118 may be located at the same location as the flow meter 116.

[0063] Figure 3 1 is a schematic diagram of a turbine engine 10 having a steam system 100b according to another embodiment of the present disclosure. For clarity of other steam systems discussed herein, the steam system 100b of this embodiment will be referred to as the second steam system 100b. The second steam system 100b can be used as Figure 1 The second steam system 100b is similar to the steam system 100b of the turbine engine 10 shown in FIG. Figure 2 The same reference numerals will be used for components of the second steam system 100b that are the same or similar to the components of the first steam system 100a discussed above. The above description of these components also applies to the present embodiment, and detailed descriptions of these components are omitted here. Similarly, reference numerals will be used for components of the second steam system 100b that are the same or similar to the components of the first steam system 100a discussed above. Figure 2 In the first steam system 100a described or referenced Figure 3 Any of the features described in the second steam system 100b may be used with the other of the first steam system 100b or the second steam system 100b.

[0064] In the first steam system 100a, the steam 128 is discussed as being injected into the core air flow path 33, wherein the first steam control valve 112 and the second steam control valve 114 control the flow of the steam 128 into the core air flow path 33. The steam 128 may be injected into the core air flow path 33 in a more complex manner, such as Figure 3 As shown in more detail in FIG. Figure 3 The second steam system 100b shown in the figure includes a steam injection system 200 and a steam delivery assembly 212. The second steam system 100b is fluidly coupled to the core air flow path 33 via the steam delivery assembly 212. The steam delivery assembly 212 includes one or more pipelines, conduits, pipes, tubes, etc., which are configured to deliver steam 128 from a steam source (such as a boiler 102) to the core air flow path 33. The steam delivery assembly 212 is fluidly connected to the core air flow path 33 to inject steam 128 into the core air flow path 33 at a plurality of steam injection zones 220, thereby adding mass flow to the core air 64, as discussed above. Each steam injection zone 220 in the plurality of steam injection zones 220 corresponds to one of the core air flow path zones.

[0065] Before discussing the steam injection region 220 in more detail, additional features of the turbine engine 10 will be discussed below. The combustor 26 is an annular combustor (i.e., annular about the longitudinal centerline axis 12) that includes a combustion chamber 130 defined between an inner liner 132 and an outer liner 134. Each of the inner liner 132 and the outer liner 134 is disposed about the turbine engine 10 ( Figure 1 ) is annular about the longitudinal centerline axis 12 and thus may extend in the circumferential direction of the turbine engine 10. The combustor 26 is an annular combustor (i.e., annular about the longitudinal centerline axis 12) and includes a combustion chamber 130 defined between an inner liner 132 and an outer liner 134. Each of the inner liner 132 and the outer liner 134 is circumferentially disposed about the turbine engine 10 ( Figure 1 ) is annular in shape and thus may extend in a circumferential direction of the turbine engine 10. The combustor 26 also includes a dome 136 mounted to the forward end of each of the inner liner 132 and the outer liner 134. The dome 136 defines the upstream (or forward end) of the combustion chamber 130.

[0066] Multiple mixer assemblies 140 ( Figure 3 A plurality of mixer assemblies 140 are spaced about the dome 136 (only one of which is shown). Figure 1 ) are circumferentially spaced about the longitudinal centerline axis 12. The mixer assembly 140 may be a swirler / fuel nozzle assembly that includes a fuel delivery assembly 84 ( Figure 1) receives a fuel nozzle 142 of the fuel 67. The fuel 67 is injected into the combustion chamber 130 through one or more orifices formed in the mixer assembly 140. The mixer assembly 140 can be any suitable mixer assembly, including a rich combustion mixer assembly or a lean combustion mixer assembly, such as a dual annular premixing swirler (TAPS). As described above, the compressor section 21 including the HPC 24 pressurizes the air, and the combustor 26 receives an annular flow of the pressurized air from the discharge outlet of the HPC 24. This air may be referred to as compressor discharge pressure air. The compressor discharge outlet may be positioned to discharge the compressor discharge pressure air into the mixing chamber, and then a portion of the compressor discharge air flows into the mixer assembly as the main air. The mixer assembly 140 may include a plurality of swirler vanes as part of a swirler, which is used to swirl the main air flowing through the mixer assembly 140 and generate turbulence in the main air flowing through the mixer assembly 140. The fuel nozzles 142 inject the fuel 67 into the turbulent flow of primary air, and the turbulence promotes rapid mixing of the fuel 67 with the primary air, creating a fuel-air mixture.

[0067] The fuel-air mixture is provided from the mixer assembly 140 to the combustion chamber 130 for combustion. Ignition of the fuel-air mixture is accomplished by an igniter (not shown), and the resulting combustion gases 66 flow toward and enter the annular turbine nozzle of the HPT 28 in the axial direction A of the turbine engine 10. Most of the fuel 67 injected by the mixer assembly 140 is burned in the main combustion zone 138 of the combustion chamber 130 in the area immediately downstream of the mixer assembly 140. The turbine nozzle is defined by an annular flow passage that includes a plurality of radially extending, circumferentially spaced HPT stator vanes 68 ( Figure 1 ), these HPT stator vanes turn the gas so that it flows at an angle and strikes the HPT rotor blades 70 ( Figure 1 ). The HPT 28 includes a rotor having a plurality of HPT rotor blades 70. The HPT rotor blades 70 are circumferentially spaced apart, and the HPT stator vanes 68 are located upstream of the HPT rotor blades 70. The rotor may be, for example, a disk or blisk drivingly connected to the HP shaft 34. As discussed above, the second steam system 100b can use a single-stage HPT 28, but other HPTs, including those having two or more stages, may also be used.

[0068] A portion of the compressor discharge pressure air may be used as dilution air (also referred to as secondary air). The dilution air flows around the outside of the inner liner 132 and the outer liner 134 and is introduced into the combustion chamber 130 through one or more dilution holes (not shown) formed in the inner liner 132 and the outer liner 134 at a location downstream of the mixer assembly 140. The dilution air helps quench the combustion gases from the primary combustion zone 138 before they are introduced into the turbine section 27. The dilution air bypasses the primary combustion zone 138 and is introduced into the combustion chamber 130 downstream of the primary combustion zone 138. Another portion of the compressor discharge pressure air may be directed into the HPT 28 as HPT cooling air. The HPT cooling air may be extracted from the dilution air and directed into the HPT rotor blades 70, and more specifically, through cooling passages formed within the HPT rotor blades 70 to cool the HPT rotor blades 70.

[0069] As the core air 64 flows through the core air flow path 33, the thermodynamics of the core air 64 (and the combustion gases 66) change, as discussed above. Therefore, the core air flow path 33 includes a plurality of core air flow path zones. As used herein, a core air flow path zone is a portion (i.e., a region or area) of the core air flow path in which the core air 64 has thermodynamic properties that are different or different from those of the surrounding or adjacent regions. For example, when the pressure and temperature of the core air 64 in each of the LPC 22 and the HPC 24 increase, the LPC 22 can be a core air flow path zone, and the HPC 24 can both be core air flow path zones. In addition, the LPC 22 and the HPC 24 can be multi-stage compressors, and each stage of the LPC 22 or the HPC 24 can also be a core air flow path zone. Similarly, the combustor 26, and more specifically, the main combustion zone 138 can be a core air flow path zone. Similar to LPC 22 and HPC 24, HPT 28 and LPT 30 may be core air flow path regions, and each stage of HPT 28 and LPT 30 may be a core air flow path region. A core air flow path 33 of turbine engine 10 is annular (i.e., annular about longitudinal centerline axis 12), and each core air flow path region may be an annular band of turbine engine 10, and more specifically, a core air flow path 33.

[0070] One of the plurality of steam injection zones 220 is a main steam injection zone 222 positioned to inject at least a portion of the steam 128 into the primary air. The steam 128 may be injected into the combustor 26, such as into the combustion chamber 130, and more specifically, into the main combustion zone 138. Figure 2As shown, the main steam injection zone 222 is the main combustion zone 138. The steam delivery assembly 212 is fluidly coupled to the mixer assembly 140 to provide the steam 128 to the mixer assembly 140 for mixing with the fuel 67 ( Figure 1 ) are injected into the main air and directly into the main combustion zone 138.

[0071] Additionally, or alternatively, the steam 128 may be injected into the combustor 26 by being injected into a steam injection zone upstream of the combustor 26, and this zone will be referred to herein as the upstream steam injection zone 224. The upstream steam injection zone 224 may be located downstream of the HPC 24, such as downstream of the mixing chamber. As discussed above, a portion of the primary air from the mixing chamber flows through the combustion chamber 130, and more specifically, through the primary combustion zone 138, and therefore, the steam 128 (or at least a portion thereof) injected into the upstream steam injection zone 224 may be injected into the primary air.

[0072] The first steam injection system 200 includes one or more steam flow control valves for selectively directing steam 128 into the core air flow path 33 and for controlling the flow of steam 128 into different injection zones. Each steam flow control valve discussed herein is a flow control valve that controls the flow rate of steam 128 through the flow control valve. The flow control valve may have a closed position and a plurality of open positions, including a fully open position. When moving from one of the plurality of open positions toward the closed position, the valve is closed, or when moving from one of the closed position or the open position toward a more open open position, the valve is opened. In addition, the steam control valve may be a proportional control valve that may be positioned to proportionally direct steam 128 to a plurality of different positions, such as a three-way valve that may be positioned to proportionally direct steam flowing through the steam flow control valve to one of the two outlets. The flow control valve may be an electrically operated valve, a hydraulically operated valve, or a pneumatically operated valve. When the flow control valve is hydraulically operated, the hydraulic fluid may be a suitable fluid of the turbine engine 10, including, for example, fuel 67, lubricating oil, etc. As will be discussed in greater detail below, these steam flow control valves are located in the steam delivery assembly 212 to direct a portion of the steam 128 to one or more steam injection locations 220 in the core air flow path 33 .

[0073] like Figure 2As shown, the steam injection system 200 includes a main steam flow control valve 226 operable to control the flow of the steam 128 into the main steam injection zone 222. Similarly, the steam injection system 200 includes an upstream steam flow control valve 228 operable to control the flow of the steam 128 into the upstream steam injection zone 224. Since the upstream steam flow control valve 228 also controls the flow of the steam 128 into the main air and main combustion zone 138, the upstream steam flow control valve 228 can also be regarded as a main flow steam flow control valve.

[0074] As discussed above, steam 128 can be injected into the core air flow path 33 in a range of 20% to 50% of the mass flow rate through the core air flow path 33. In order to achieve the benefits of waste heat recovery discussed herein, this amount of steam 128 (water vapor) is beneficial when flowing through the turbine section 27, and more specifically, flowing through the HPT 28 and the LPT 30. In addition, the required amount of steam can change throughout the flight of the aircraft based on operating conditions. Introducing the amount of steam discussed above so that all of the steam 128 flows through the main combustion zone 138 may cause flame stability and flame dynamics problems in the combustion chamber 130. Therefore, the main steam flow control valve 226 and the upstream steam flow control valve 228 can be used to control the steam 128 injected at the main steam injection zone 222, the upstream steam injection zone 224, or both to maintain the flow rate of steam flowing through the main combustion zone 138 at a desired level. With the flow rate of steam injected at the primary steam injection zone 222 and the upstream steam injection zone 224 limited to achieve the desired steam level, the remaining portion of the steam 128 is injected into the core air flow path 33 at one or more zones downstream of the primary combustion zone 138, which are referred to herein as downstream steam injection zones or secondary steam injection zones. One or more secondary steam flow control valves 230 may be located in the steam delivery assembly 212 to control the flow of steam 128 into the secondary steam injection zones.

[0075] Although the secondary steam flow control valve 230 can be an active valve, as described above, the secondary steam flow control valve 230 can alternatively be a pressure regulating valve. The pressure regulating valve is operable to inject steam at an output pressure proportional to a control pressure. The control pressure can be provided by another fluid of the turbine engine 10, such as the core air 64, and more specifically, the pressure of the compressed air 65. The secondary steam flow control valve 230 can be fluidly connected to the core air 64 (e.g., compressed air 65) to receive the control pressure.

[0076] As the steam 128 is injected into the mixing chamber, some of the steam 128 will be combined with the dilution air and HPT cooling air and injected into the combustor 26 and HPT 28, respectively, due to the natural distribution of the compressor discharge pressure air between the multiple flow paths of the compressor discharge pressure air downstream of the HPC 24. In this way, the steam 128 is introduced into the core air flow path 33 at a zone downstream of the main combustion zone 138, where the dilution air and HPT cooling air flow into the hot gas path 78. However, under certain operating conditions, such as high power conditions with relatively high steam demand, this natural flow distribution may not be sufficient to maintain the main air at the levels discussed above. Therefore, the steam delivery assembly 212 is fluidly connected to the core air flow path 33 to inject steam 128 at other downstream zones, regardless of the steam 128 injected into the main air (e.g., at the upstream steam injection zone 224).

[0077] The steam delivery assembly 212 may be fluidly connected to the HPT 28 to inject a portion of the steam 128 directly into the HPT 28. For example, the steam delivery assembly 212 may be fluidly connected to an outlet (e.g., an orifice) formed in the HPT stator vanes 68 of the HPT 28 to selectively inject the steam 128 into the core air flow path 33. This steam injection region is referred to herein as an HP turbine nozzle steam injection region 232. As described above, the HPT 28 may have one stage. If the HPT 28 has multiple stages, the HP turbine nozzle steam 234 and the HP turbine blade steam 236 may be directed through openings in any one or all stages.

[0078] The steam delivery assembly 212 may also be injected directly into the combustion chamber 130 at a location downstream of the primary combustion zone 138. A portion of the steam 128 may flow into a combustor liner passage around the combustor liner (e.g., the inner liner 132, the outer liner 134, or both) and then into the combustion chamber 130 through steam holes located in the combustor liner downstream of the primary combustion zone 138. This steam injection zone is referred to herein as a downstream combustor steam injection zone 234. In addition to adding mass flow to the combustion gases 66, the steam 128 may also be used to help cool the combustor liner, and the steam 128 injected in the downstream combustor steam injection zone 234 may be steam injected into a cooling flow path of the combustor 26.

[0079] The steam delivery assembly 212 may also be directly fluidly connected to a cooling passage formed in the HPT rotor blade 70, bypassing the mixing chamber, to inject a portion of the steam 128 into the HPT 28 via the HPT rotor blade 70. The steam 128 may be injected through an opening (e.g., an orifice) formed in the HPT rotor blade 70. This steam injection region is referred to herein as an HP turbine blade steam injection region 236.

[0080] Although all of the steam 128 may flow through the HPT 28, a portion of the steam 128 may be directed into the LPT 30 through openings formed in one or more LPT rotor blades 74 (e.g., a first stage LPT rotor). More specifically, the LPT rotor blades 74 may include cooling passages formed in the LPT rotor blades 74 through which cooling air (e.g., compressor bleed air extracted from one stage of the HPC 24) flows. The compressor bleed air may then be exhausted from the cooling air passages through a plurality of openings (e.g., orifices) formed in the LPT rotor blades 74. The steam 128 injected through the cooling passages formed in the LPT rotor blades 74 may be mixed with the compressor bleed air that is exhausted through the openings in the LPT rotor blades 74. Alternatively, the steam 128 may be injected as pure steam. The steam injection region is referred to herein as the LP turbine steam injection region 238. Although described as being injected through the LPT rotor blades 74 , the steam 128 injected in the LP turbine steam injection region 238 , or a portion thereof, may additionally or alternatively be injected into the LPT 30 through the LPT stator vanes 72 .

[0081] Figure 4 It shows the control Figure 3 100a. A flow chart of a method for a steam system shown in . More details about the operation of the aforementioned components and the described method are described above. The method can be implemented by a controller 150, and the controller 150 can be configured to perform the steps of the method discussed below. Although the following discussion relates to the second steam system 100b, the discussion is also applicable to the first steam system 100a, and when applied to the first steam system 100a, the valve positioning for controlling the flow of steam 128 can be achieved by positioning one or both of the first steam control valve 112 and the second steam control valve 114.

[0082] The method may start with monitoring any or all of the operating conditions of the aircraft, turbine engine 10, or ambient air in step S302. The operating conditions may include, for example, engine temperature and pressure, such as the temperature and pressure of various parts of the core air 64, bypass air 62, or ambient air around the turbine engine 10. These conditions may also be the rotational speed of various shafts, such as the engine shaft discussed above. Such conditions may be monitored to determine in step S304 whether the turbine engine 10 is in a steady state operating condition. The steady state operating condition may be a condition in which the turbine engine 10 is at a constant power level (taking into account average fluctuations) and is not accelerating or decelerating. If the turbine engine 10 is in a steady state, the positions of the main steam flow control valve 226 and the secondary steam flow control valve 230 are maintained in step S306. In step S306, the output of the water pump 108 may also be maintained. Although the discussion of the present method relates to the main steam flow control valve 226, the upstream steam flow control valve 228 can be the main steam flow control valve, and when used in this manner, the discussion of the upstream steam injection zone 224 also applies to the upstream steam flow control valve 228. Similarly, when the upstream steam flow control valve 228 is used as a secondary steam flow control valve, the discussion of the secondary steam flow control valve 230 also applies to the upstream steam flow control valve 228.

[0083] If the turbine engine 10 is changing its operating conditions, the method proceeds to step S310 to determine whether the change in the operating condition of the turbine engine 10 is an acceleration or a deceleration. When implemented by the controller 150, the controller 150 may receive inputs indicating or otherwise used to determine a change in the operating condition of the turbine engine 10. Such inputs may include inputs and control signals from a flight controller, such as a throttle input from a pilot. Other inputs include, for example, inputs related to conditions sensed by the controller 150, such as changes in pressure or speed of the turbine engine 10.

[0084] If turbine engine 10 is accelerating, the method moves to step S322 where fuel 67 flow is increased, such as by opening metering valve 90. As steam demand increases, in step S324, the output of water pump 108 is increased in the manner discussed above to increase the amount of steam 128 flowing to steam delivery assembly 212.

[0085] The main steam flow control valve 226 is opened to increase the amount of steam 128 entering the main steam injection zone 222. The steam flow rate can be increased in proportion to the flow rate of the fuel 67. In step S326, one or more steam flow control valves (e.g., the main steam flow control valve 226 or the secondary steam flow control valve 230) can then be opened to provide the required amount of steam 128 to the core air flow path 33. For example, the main steam flow control valve 226 can be opened to increase the amount of steam 128 entering the main steam injection zone 222, and the secondary steam flow control valve 230 can be opened to inject the remaining required amount of steam 128 into the core air flow path 33. Although this can be done actively, when a passive valve (e.g., the fluid dynamic pressure regulating valve discussed above) is used, the secondary steam flow control valve 230 can be passively operated in response to pressure changes in the control pressure. The target speed of the turbine engine 10 is checked in step S328. If the target speed has not been reached, the method returns to step S322, but if the target speed has been reached, the process returns to step S304.

[0086] If the turbine engine 10 is decelerating, the method moves to step S332, where the main steam flow control valve 226 is closed, thereby reducing the flow of steam 128 into the main combustion zone 138. Then, in step S333, the output of the water pump 108 is reduced. In step S334, the secondary steam flow control valve 230 can then be closed to reduce the amount of steam 128 entering the core air flow path 33. Although this can be done actively, when a passive valve (such as the fluid dynamic pressure regulating valve discussed above) is used, the secondary steam flow control valve 230 can be passively operated in response to pressure changes in the control pressure. The method then continues to step S336 to reduce the fuel 67 flow, such as by closing the metering valve 90. During the deceleration of the turbine engine 10, the amount of steam 128 injected into the main steam injection zone 222 can be reduced to minimize the possibility of flameout due to the reduction in fuel 67 flow. Steam 128 can be reduced before or at the same time as the fuel 67 flow is reduced. In step S338, the target speed of the turbine engine 10 is checked. If the target speed has not been reached, the method returns to step S332, but if the target speed has been reached, the process returns to step S304.

[0087] The turbine engine 10 discussed herein includes a steam system 100 for recovering some energy from waste heat by generating steam 126 and driving a steam turbine 110. After flowing through the steam turbine 110, the steam 128 may be injected into the core air flow path 33. The required amount of steam 126, 128 may vary based on the operating conditions of the turbine engine 10 (such as the power level), and the amount of steam 128 injected into the core air flow path 33 by the steam system 100 may be controlled based on the operating conditions of the turbine engine 10 to provide the required amount of steam 128. The embodiments discussed herein provide methods and systems for controlling the amount of steam 128 injected into the core air flow path 33, and the amount of steam 128 injected into the core air flow path 33 may be controlled by controlling a water pump that directs water flow to a boiler that generates steam.

[0088] Further aspects of the disclosure are provided by the subject matter of the following clauses.

[0089] A turbine engine for an aircraft. The turbine engine includes a turbocharger, a fan having a fan shaft, and a steam system, wherein the fan shaft is coupled to the turbocharger to rotate the fan shaft. The turbocharger includes a burner, an engine shaft, and a turbine. The burner is positioned in a core air flow path to receive compressed air. The core air flow path includes a plurality of core air flow path zones for core air to flow therethrough. The burner is fluidly coupled to a fuel source to receive fuel. The fuel is injected into the burner to mix with the compressed air to produce a fuel and air mixture. The fuel and air mixture is burned in a primary combustion zone of the burner to produce combustion gases. The turbine is located downstream of the burner for receiving the combustion gases and rotating the turbine. The turbine is coupled to the engine shaft to rotate the engine shaft when the turbine rotates. The steam system is fluidly coupled to the core air flow path to provide steam to the core air flow path, thereby adding mass flow to the core air. The steam system includes a boiler, a water pump, and a controller. The boiler is located downstream of the burner. The boiler receives water and is fluidly connected to the burner to receive the combustion gases and boil the water to produce the steam. The water pump is in fluid communication with the boiler for directing a flow of water into the boiler. The controller is operably coupled to the water pump to control an output of the water pump, the flow of water entering the boiler, and an amount of the steam injected into the core air flow path. The controller is configured to change the output of the water pump in response to an input received by the controller indicating a change in an operating condition of the turbine engine.

[0090] A turbine engine according to the preceding clause, wherein said steam system includes a condenser positioned downstream of said boiler to condense said water from said combustion gases, said water pump being fluidly connected to said condenser to receive said water therefrom.

[0091] A turbine engine according to the preceding clause, wherein the condenser produces an exhaust-water mixture, and the steam system includes a water separator, the water separator being located downstream of the condenser to receive the exhaust-water mixture, the water separator separating the water from the exhaust-water mixture, the water pump being fluidly connected to the water separator to receive the water from the water separator.

[0092] A turbine engine according to any preceding clause, further comprising a nacelle circumferentially surrounding said fan.

[0093] A turbine engine as described in any preceding clause, wherein the fan includes a plurality of fan blades that rotate to generate a volume of air.

[0094] A turbine engine according to the preceding clause, wherein the nacelle defines a bypass airflow passage between the nacelle and the turbocharger engine, wherein the volume of air from the fan is diverted into the bypass airflow passage as bypass air and into the core air flow path as core air.

[0095] A turbine engine according to the preceding clause, wherein the water separator is a cyclone separator.

[0096] A turbine engine as claimed in any preceding clause, wherein said condenser is located in said bypass air flow passage for bypass air cooling of said combustion gases and condensing said water therefrom.

[0097] A turbine engine as claimed in any preceding clause, wherein, to control the output of the water pump, the controller is operatively coupled to the water pump to control a speed of the water pump.

[0098] A turbine engine as claimed in any preceding clause, wherein the water pump is a centrifugal pump.

[0099] A turbine engine as described in any preceding clause, wherein the water pump is a positive displacement pump.

[0100] A turbine engine according to the preceding clause, wherein, in order to control the output of the water pump, the controller is operatively coupled to the water pump to control the displacement of the water pump.

[0101] A turbine engine according to any preceding clause, wherein the steam system includes a flow meter located between the water pump and the boiler for measuring the output of the water pump, and the controller is connected to the flow meter to: receive input from the flow meter, determine the mass flow rate of the water output by the water pump, and control the output of the water pump to achieve a target mass flow rate.

[0102] A turbine engine as claimed in any preceding clause, wherein the flow meter is a mass flow meter.

[0103] A turbine engine according to any preceding clause, wherein the flow meter is a volume flow meter and the steam system includes a temperature sensor located between the water pump and the boiler for measuring the temperature of the water output from the water pump, the controller being connected to the temperature sensor to receive input from the temperature sensor and converting the volume flow measured by the flow meter into a mass flow rate.

[0104] A turbine engine according to any preceding clause, wherein the steam system includes at least one steam control valve located downstream of the boiler and upstream of the core air flow path to control the flow of the steam into the core air flow path.

[0105] A turbine engine according to the preceding clause, wherein the controller is operably coupled to the at least one steam control valve to change the position of the at least one steam control valve in response to the input received by the controller indicative of a change in the operating condition of the turbine engine.

[0106] A turbine engine according to any preceding clause, wherein the steam system includes a steam turbine fluidly coupled to the boiler to receive the steam from the boiler and rotate the steam turbine, the steam turbine coupled to the engine shaft to rotate the engine shaft when the steam turbine rotates.

[0107] A turbine engine according to the preceding clause, wherein said at least one steam control valve is located upstream of said steam turbine.

[0108] A turbine engine as claimed in any preceding clause, wherein the at least one steam control valve is located downstream of the steam turbine.

[0109] A turbine engine according to any preceding clause, wherein the at least one steam control valve is one of a plurality of steam control valves, the plurality of steam control valves comprising a first steam control valve and a second steam control valve, the first steam control valve being located upstream of the steam turbine and the second steam control valve being located downstream of the steam turbine.

[0110] The turbine engine of any preceding clause, wherein the controller is communicatively coupled to a sensor that sends the input indicative of the change in the operating condition of the turbine engine to the controller.

[0111] A turbine engine according to any preceding clause, further comprising said sensor.

[0112] A turbine engine as claimed in any preceding clause, wherein the sensor is located in the core air flow path.

[0113] A turbine engine as claimed in any preceding clause, wherein the sensor is a temperature sensor and the input indicative of the change in the operating condition of the turbine engine is a temperature detected by the temperature sensor.

[0114] A turbine engine as claimed in any preceding clause, wherein the sensor is a pressure sensor and the input indicative of the change in the operating condition of the turbine engine is a pressure detected by the pressure sensor.

[0115] A turbine engine according to any preceding clause, wherein the core air flow path includes a plurality of core air flow path zones, and the steam system fluid is coupled to the core air flow path to inject the steam into the core air flow path at a plurality of steam injection zones, each of the plurality of steam injection zones corresponding to a core air flow path zone of the plurality of core air flow path zones.

[0116] A turbine engine according to the preceding clause, wherein the steam system includes a main steam flow control valve, which is operable to control the flow of the steam entering a main steam injection zone, the main steam injection zone being one of the multiple steam injection zones, the main steam injection zone being a steam injection zone positioned in the core air flow path so that the steam injected into the main steam injection zone flows into the main combustion zone, the controller being operably connected to the main steam flow control valve and configured to adjust the position of the main steam flow control valve to control the flow of the steam entering the main steam injection zone.

[0117] A turbine engine according to the preceding clause, wherein the steam system includes a secondary steam flow control valve, the secondary steam flow control valve being operable to control the flow of the steam entering a secondary steam injection zone, the secondary steam injection zone being one of the plurality of steam injection zones, the controller being operably connected to the secondary steam flow control valve and being configured to adjust the position of the secondary steam flow control valve to control the flow of the steam entering the secondary steam injection zone.

[0118] A turbine engine according to any preceding clause, wherein the controller is configured to determine whether the turbine engine is accelerating or decelerating, and when the controller determines that the turbine engine is accelerating or decelerating, the controller is configured to change the output of the water pump and adjust the position of the main steam flow control valve to change the flow of the steam entering the main steam injection zone.

[0119] A turbine engine according to any preceding clause, wherein the controller is configured to determine whether the turbine engine is accelerating, and when the controller determines that the turbine engine is accelerating, the controller is configured to change the output of the water pump and adjust the position of the main steam flow control valve to change the flow of the steam entering the main steam injection zone.

[0120] A turbine engine according to the preceding clause, wherein when the controller determines that the turbine engine is accelerating, the controller is configured to increase the output of the water pump and open the main steam flow control valve to increase the flow of the steam into the main steam injection zone.

[0121] A turbine engine according to any preceding clause, wherein the controller is configured to determine whether the turbine engine is decelerating, and when the controller determines that the turbine engine is decelerating, the controller is configured to change the output of the water pump and adjust the position of the main steam flow control valve to change the flow of the steam entering the main steam injection zone.

[0122] A turbine engine according to the preceding clause, wherein, when the controller determines that the turbine engine is decelerating, the controller is configured to close the main steam flow control valve to reduce the flow of the steam entering the main steam injection zone, and after closing the main steam flow control valve, reduce the output of the water pump.

[0123] A turbine engine according to any preceding clause, wherein the turbocharger engine includes a compressor positioned in the core air flow path, upstream of the combustor, to compress core air to produce the compressed air, a steam injection zone being located downstream of the compressor and upstream of the main combustion zone.

[0124] A turbine engine according to any preceding clause, wherein the turbocharger engine includes a compressor positioned in the core air flow path, upstream of the combustor, to compress core air to produce the compressed air, a steam injection zone being located downstream of the compressor and upstream of the combustor.

[0125] A turbine engine according to any preceding clause, wherein a steam injection zone is said primary combustion zone.

[0126] A turbine engine as claimed in any preceding clause, wherein the turbocharger engine comprises a combined fuel and steam nozzle assembly to inject both the steam and the fuel into the primary combustion zone.

[0127] A turbine engine as claimed in any preceding clause, wherein a steam injection zone is a portion of the combustor downstream of the main combustion zone.

[0128] A turbine engine as claimed in any preceding clause, wherein the combustor comprises a combustor cooling passage through which the steam is injected into the combustor.

[0129] A turbine engine according to any preceding clause, wherein a steam injection zone is located in the turbine downstream of the combustor.

[0130] A turbine engine as claimed in any preceding clause, wherein a steam injection zone is an inlet to the turbine.

[0131] A turbine engine as claimed in any preceding clause, wherein the turbine comprises a turbine cooling passage through which the steam is injected into the turbine.

[0132] A turbine engine according to any preceding clause, wherein the turbine is a high pressure turbine.

[0133] A turbine engine according to any preceding clause, wherein the turbine is a low pressure turbine.

[0134] A turbine engine according to any of the preceding clauses, wherein the steam system includes a main steam flow control valve, which is capable of operating to control the flow of the steam into a main steam injection zone, the main steam injection zone being one of the multiple steam injection zones, the main steam injection zone being a steam injection zone positioned in the core air flow path, so that the steam injected into the main steam injection zone flows into the main combustion zone.

[0135] A turbine engine as described in any preceding clause, wherein the steam system includes a secondary steam flow control valve, the secondary steam flow control valve being operable to control the flow of the steam into a secondary steam injection zone, the secondary steam injection zone being one of the plurality of steam injection zones.

[0136] A turbine engine as described in any preceding clause, wherein the primary steam injection zone is the primary combustion zone.

[0137] A turbine engine as described in any preceding clause, wherein the controller is operably coupled to the main steam flow control valve and configured to adjust a position of the main steam flow control valve to control a flow of the steam into the main steam injection zone.

[0138] A turbine engine as recited in the preceding clause, wherein said controller is operably coupled to said secondary steam flow control valve and configured to adjust a position of said secondary steam flow control valve to control flow of said steam into said secondary steam injection zone.

[0139] A turbine engine as claimed in any preceding clause, wherein the controller is configured to determine whether the turbine engine is accelerating or decelerating.

[0140] A turbine engine according to the preceding clause, wherein when the controller determines that the turbine engine is accelerating, the controller is configured to open the main steam flow control valve to increase the flow of the steam into the main steam injection zone.

[0141] A turbine engine as claimed in any preceding clause, wherein when the controller determines that the turbine engine is decelerating, the controller is configured to close the main steam flow control valve to reduce the flow of the steam into the main steam injection zone.

[0142] A turbine engine as claimed in any preceding clause, wherein the secondary steam flow control valve is a pressure regulating valve operable to inject steam at an output pressure proportional to a control pressure.

[0143] Turbine engine according to the preceding clause, wherein said control pressure is the pressure of said core air.

[0144] A turbine engine according to any preceding clause, wherein the turbocharger engine includes a compressor positioned in the core air flow path, upstream of the combustor, to compress core air to produce the compressed air, the control pressure being the pressure of the core air at the outlet of the compressor.

[0145] A turbine engine according to any preceding clause, wherein the turbine is a high pressure turbine and the steam injection zone is located in the high pressure turbine.

[0146] A turbine engine as claimed in any preceding clause, wherein the steam system comprises a high pressure turbine steam flow control valve to control the flow of the steam to the high pressure turbine.

[0147] A turbine engine according to any preceding clause, wherein the high pressure turbine comprises a turbine rotor comprising a plurality of rotor blades, and the steam injection region is the plurality of rotor blades.

[0148] The turbine engine according to the preceding clause, wherein cooling air is provided to said plurality of rotor blades, said steam being mixed with said cooling air.

[0149] A turbine engine according to any preceding clause, wherein the high pressure turbine comprises a plurality of stator blades and the steam injection zone is the plurality of stator blades.

[0150] A turbine engine as claimed in the preceding clause, wherein cooling air is provided to said plurality of stator blades, said steam being mixed with said cooling air.

[0151] A turbine engine as claimed in any preceding clause, wherein the turbocharger engine comprises a high pressure compressor positioned in the core air flow path upstream of the combustor to produce the compressed air.

[0152] A turbine engine according to any preceding clause, wherein the engine shaft is a high pressure shaft.

[0153] A turbine engine as described in any preceding clause, wherein the high pressure compressor is driven by the high pressure shaft to compress the core air flowing through the core air flow path and produce the compressed air.

[0154] A turbine engine as claimed in any preceding clause, wherein the turbocharged engine comprises a low pressure compressor positioned in the core air flow path upstream of the high pressure compressor to produce the compressed air.

[0155] A turbine engine according to any of the preceding clauses, wherein the turbocharged engine includes a low-pressure turbine positioned in the core air flow path downstream of the high-pressure turbine to receive the combustion gases and rotate the turbine.

[0156] A turbine engine according to any of the preceding clauses, wherein the turbocharged engine includes a low-pressure shaft to which the low-pressure turbine is coupled to rotate the low-pressure shaft when the low-pressure turbine rotates.

[0157] A turbine engine according to the preceding clause, wherein one of the plurality of steam injection zones is located in the low-pressure turbine.

[0158] A turbine engine according to the preceding clause, wherein the low-pressure turbine includes a turbine rotor including a plurality of rotor blades, and the steam injection zone is the plurality of rotor blades.

[0159] A turbine engine according to any of the preceding clauses, wherein the turbocharged engine includes a compressor positioned in the core air flow path upstream of the burner to compress core air to produce the compressed air.

[0160] A turbine engine according to the preceding clause, wherein the compressor is driven by the high-pressure shaft to compress the core air flowing through the core air flow path and produce the compressed air.

[0161] A turbine engine according to any of the preceding clauses, wherein the turbine is a low-pressure turbine and the steam injection zone is located in the low-pressure turbine.

[0162] A turbine engine according to the preceding clause, wherein the low-pressure turbine includes a turbine rotor including a plurality of rotor blades, and the steam injection zone is the plurality of rotor blades.

[0163] A turbine engine according to any of the preceding clauses, wherein the engine shaft is a low-pressure shaft and the turbine is a low-pressure turbine.

[0164] A turbine engine according to any of the preceding clauses, wherein the fan shaft is coupled to the low-pressure shaft to be driven by the low-pressure shaft.

[0165] A turbine engine according to any of the preceding clauses, wherein the steam system includes a steam delivery assembly fluidly coupled to the plurality of steam injection locations to inject the steam and the water into the core air flow path at the plurality of steam injection locations.

[0166] A turbine engine as described in any preceding clause, wherein the steam delivery assembly includes a steam inlet for receiving the steam generated by the steam system.

[0167] A turbine engine as in any preceding clause, wherein the steam flow control valve is located in the steam delivery assembly and is operable to vary the distribution of the steam injected into the core air flow path.

[0168] The turbine engine of any preceding clause, wherein the steam delivery assembly is fluidly coupled to the steam system downstream of the steam turbine to receive the steam from the steam turbine.

[0169] A method of operating a turbine engine for an aircraft having a steam system. The method includes injecting fuel into a burner positioned in a core air flow path to receive compressed air, mixing the fuel with the compressed air to produce a fuel and air mixture, and combusting the fuel and air mixture in a primary combustion zone of the burner to produce combustion gases. The method also includes boiling water in a boiler to produce steam, the boiler being located downstream of the burner and fluidly connected to the burner to receive the combustion gases and boil the water. The method further includes directing a flow of water into the boiler using a water pump, and controlling the output of the water pump to control the amount of the steam injected into the core air flow path.

[0170] The method of the preceding clause, further comprising condensing the water from the combustion gases in a condenser positioned downstream of the boiler, the water pump being fluidly connected to the condenser to receive the water therefrom.

[0171] A method according to the preceding clause, wherein the condenser produces an exhaust-water mixture, and the method further comprises separating the water from the exhaust-water mixture using a water separator, the water separator being located downstream of the condenser to receive the exhaust-water mixture, the water pump being fluidly connected to the water separator to receive the water from the water separator.

[0172] A method as in any preceding clause, wherein controlling the output of the water pump comprises controlling the speed of the water pump.

[0173] A method as in any preceding clause, wherein controlling the output of the water pump comprises controlling the displacement of the water pump.

[0174] A method as claimed in any preceding clause, further comprising determining a mass flow rate of the water output by the water pump, and controlling the output of the water pump to achieve a target mass flow rate.

[0175] A method according to any preceding clause, further comprising measuring the output of the water pump with a flow meter located between the water pump and the boiler, and controlling the output of the water pump based on the output of the flow meter.

[0176] A method according to the preceding clause, wherein the flow meter is a mass flow meter.

[0177] A method according to any preceding clause, wherein the flow meter is a volume flow meter that measures the volume flow rate of the water output by the water pump, and the method further comprises measuring the temperature of the water output from the water pump and converting the volume flow rate to a mass flow rate based on the measured temperature.

[0178] A method as described in the preceding clause, wherein measuring the temperature of the water output from the water pump comprises using a temperature sensor located between the water pump and the boiler.

[0179] A method as in any preceding clause, further comprising varying the output from the water pump when operating conditions of the turbine engine change.

[0180] A method as claimed in any preceding clause, further comprising increasing output of said water from said water pump when said engine is accelerating.

[0181] A method as claimed in any preceding clause, further comprising reducing output of said water from said water pump when said engine is decelerating.

[0182] A method as described in any preceding clause, further comprising operating a steam flow control valve to control the amount of said steam injected into said core air flow path.

[0183] A method according to the preceding clause, wherein the steam flow control valve is operated when operating conditions of the turbine engine change.

[0184] A method as in any preceding clause, further comprising injecting the steam into the core air flow path at a plurality of steam injection zones, thereby adding mass flow to the core air.

[0185] A method according to the preceding clause, wherein injecting the steam into the core air flow path includes injecting the steam into a main steam injection zone, wherein the main steam injection zone is a steam injection zone positioned in the core air flow path, such that the steam injected into the main steam injection zone flows into the main combustion zone.

[0186] A method as in any preceding clause, wherein injecting the steam into the core air flow path comprises injecting steam into a secondary steam injection zone.

[0187] A method as in any preceding clause wherein the secondary steam injection zone is located downstream of the combustor.

[0188] A method as in any preceding clause, wherein the secondary steam injection zone is a cooling air flow path for a component of the turbine engine.

[0189] A method as claimed in any preceding clause, wherein the turbine engine comprises a turbine as claimed in any preceding clause.

[0190] A method as in any preceding clause, further comprising determining whether the turbine engine is accelerating or decelerating.

[0191] A method as claimed in the preceding clause, further comprising increasing the flow of fuel to the burner when the engine is accelerating.

[0192] A method as in any preceding clause, wherein increasing the flow of fuel to the burner comprises opening a fuel metering valve.

[0193] A method as defined in any preceding clause, further comprising increasing the flow of said steam to said main steam injection zone when said engine is accelerating.

[0194] A method as defined in the preceding clause, wherein the flow rate of the steam to the main steam injection zone is increased in proportion to an increase in the amount of the fuel delivered to the combustor.

[0195] A method as described in any preceding clause, wherein increasing the flow of the steam to the main steam injection zone comprises opening a main steam flow control valve.

[0196] A method as claimed in any preceding clause, further comprising increasing the flow of said steam to said secondary steam injection zone when said engine is accelerating.

[0197] A method as described in the preceding clause, wherein increasing the flow of the steam to the secondary steam injection zone comprises opening a secondary steam flow control valve.

[0198] A method as claimed in the preceding clause, further comprising reducing the flow of fuel to the burner when the engine is decelerating.

[0199] A method as in any preceding clause, wherein reducing the flow of fuel to the burner comprises closing a fuel metering valve.

[0200] A method as claimed in any preceding clause, further comprising reducing the flow of steam to the main steam injection zone when the engine is decelerating.

[0201] A method as defined in the preceding clause, wherein the flow rate of said steam to said main steam injection zone is reduced in proportion to an increase in the amount of said fuel delivered to said combustor.

[0202] A method as in any preceding clause, wherein reducing the flow of the steam to the main steam injection zone comprises closing a main steam flow control valve.

[0203] A method as claimed in any preceding clause, further comprising reducing the flow of said steam to said secondary steam injection zone when said engine is decelerating.

[0204] The method of the preceding clause, wherein reducing the flow of the steam to the secondary steam injection zone comprises closing a secondary steam flow control valve.

[0205] A method as described in any preceding clause, wherein the secondary steam flow control valve is a pressure regulating valve operable to inject steam at an output pressure proportional to a control pressure.

[0206] A method as in any preceding clause, wherein the control pressure is the pressure of the core air.

[0207] A method as in any preceding clause, wherein the control pressure is the pressure of the compressed air.

[0208] A method as in any preceding clause, wherein the control pressure is the pressure of the core air at the outlet of a compressor.

[0209] A method according to the preceding clause, wherein the compressor is a compressor of a turbine engine according to any preceding clause.

[0210] A method according to any preceding clause, further comprising operating a turbine engine according to any preceding clause.

[0211] A turbine engine according to any preceding clause, further comprising a controller configured to perform a method according to any preceding clause.

[0212] A computer readable storage medium having stored thereon a series of instructions for use in a method according to any preceding clause.

[0213] Although the above description is directed to certain embodiments, other variations and modifications will be apparent to those skilled in the art and may be made without departing from the spirit or scope of the present disclosure. In addition, features described in conjunction with one embodiment may be used in conjunction with other embodiments, even if not explicitly stated above.

Claims

1. A turbine engine for an aircraft, characterized in that: The turbine engine comprises: A turbocharged engine, the turbocharged engine comprising: a combustor positioned in a core air flow path to receive compressed air, the core air flow path including a plurality of core air flow path zones for core air to flow therethrough, the combustor fluidly coupled to a fuel source to receive fuel, the fuel being injected into the combustor to mix with the compressed air to produce a fuel and air mixture, the fuel and air mixture combusting in a primary combustion zone of the combustor to produce combustion gases; engine shaft; and a turbine located downstream of the combustor for receiving the combustion gases and rotating the turbine, the turbine being coupled to the engine shaft to rotate the engine shaft when the turbine rotates; a fan having a fan shaft coupled to the turbocharger engine for rotation of the fan shaft; and a steam system fluidly coupled to the core air flow path to provide steam to the core air flow path to add mass flow to the core air, the steam system comprising: a boiler located downstream of the burner, the boiler receiving water and fluidly connected to the burner to receive the combustion gases and boil the water to generate the steam; a water pump in fluid communication with the boiler for directing a flow of water into the boiler; and a controller operably coupled to the water pump to control an output of the water pump, the flow of water entering the boiler, and an amount of the steam injected into the core air flow path, wherein the controller is configured to vary the output of the water pump in response to input received by the controller indicative of a change in an operating condition of the turbine engine.

2. The turbine engine according to claim 1, characterized in that The steam system includes a condenser positioned downstream of the boiler to condense the water from the combustion gas, and the water pump is fluidly connected to the condenser to receive the water from the condenser.

3. The turbine engine according to claim 2, characterized in that: wherein the condenser produces an exhaust-water mixture, and The steam system includes a water separator, which is located downstream of the condenser to receive the exhaust-water mixture, the water separator separates the water from the exhaust-water mixture, and the water pump is fluidly connected to the water separator to receive the water from the water separator.

4. The turbine engine according to claim 1, characterized in that: in, To control the output of the water pump, the controller is operably coupled to the water pump to control a speed of the water pump.

5. The turbine engine according to claim 4, characterized in that The water pump is a centrifugal pump.

6. The turbine engine according to claim 1, characterized in that Wherein the water pump is a positive displacement pump.

7. The turbine engine according to claim 6, characterized in that in, To control the output of the water pump, the controller is operably coupled to the water pump to control a displacement of the water pump.

8. The turbine engine according to claim 1, characterized in that The steam system includes a flow meter located between the water pump and the boiler for measuring the output of the water pump, and the controller is connected to the flow meter to: receive input from the flow meter, determine the mass flow rate of the water output by the water pump, and control the output of the water pump to achieve a target mass flow rate.

9. The turbine engine according to claim 8, characterized in that Wherein the flow meter is a mass flow meter.

10. The turbine engine according to claim 8, characterized in that wherein the flow meter is a volume flow meter for measuring the volume flow of the water output by the water pump, and The steam system includes a temperature sensor located between the water pump and the boiler for measuring the temperature of the water output from the water pump, and the controller is connected to the temperature sensor to receive input from the temperature sensor and convert the volume flow rate of the water output by the water pump measured by the flow meter into a mass flow rate of the water output by the water pump.

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