Improved Turbomachinery Heat Transfer System

Abstract

The present invention is titled "Improved Turbomachinery Heat Transfer System". The present invention provides a thermal management system (17) for a turbomachine (10). The thermal management system (17) includes a heat transfer system (18) configured to provide heating, cooling, or a combination thereof to the turbomachine (10). The heat transfer system (18) includes a first heat transfer conduit (152) and a second heat transfer conduit (154). The second heat transfer conduit (154) is disposed adjacent to the first heat transfer conduit (152) on the turbomachine (10). The thermal management system (17) further includes a controller (14) operatively coupled to the heat transfer system (18) and configured to control heating, cooling, or a combination thereof of the turbomachine (10) via the heat transfer system (18).

Description

BACKGROUND OF THE INVENTION

[0001] The subject matter disclosed herein relates to heat transfer systems, and more particularly, to heat transfer systems in turbomachinery.

[0002] Turbomachinery, such as gas turbine systems, can provide power for generating electricity. For example, many gas turbine systems typically include: a compressor section for compressing a working fluid, such as air; a combustor for combusting the compressed working fluid with fuel; and a turbine section for converting the combusted fluid into rotational power. Compressed air is injected into the combustor, where the compressed air combines with fuel to produce combustion gases that expand as the combustion gases enter the turbine section. The expanded fluid is forced through the turbine section. Then, for example, through a series of blade stages, the turbine section can convert the expanded fluid into rotational power. This rotational power can then be used to drive a load, which can include a generator for generating electricity and can be electrically connected to a power distribution network.

[0003] Turbomachinery can generate heat during operation. Improving heat transfer in turbomachinery can be useful. SUMMARY OF THE INVENTION

[0004] Certain embodiments are outlined below that are equivalent in scope to the originally claimed subject matter. These embodiments are not intended to limit the scope of the claimed subject matter, but rather these embodiments are only intended to provide a brief overview of possible forms of the subject matter. In fact, the systems of the present invention can include various forms that can be similar or different from the embodiments set forth below.

[0005] In a first embodiment, a thermal management system includes a heat transfer system configured to provide heating, cooling, or a combination thereof to turbomachinery. The heat transfer system includes a first heat transfer conduit and a second heat transfer conduit disposed on the turbomachinery adjacent to the first heat transfer conduit. The thermal management system further includes a controller operatively coupled to the heat transfer system and configured to control heating, cooling, or a combination thereof of the turbomachinery via the heat transfer system.

[0006] In a second embodiment, a method includes: providing heating, cooling, or a combination thereof to turbomachinery via a first heat transfer conduit and a second heat transfer conduit included in a heat transfer system, where the second heat transfer conduit is disposed on the turbomachinery adjacent to the first heat transfer conduit. The method further includes: controlling heating, cooling, or a combination thereof of the turbomachinery via a controller operatively coupled to the heat transfer system to minimize or eliminate position changes, structural changes, or a combination thereof in one or more turbomachinery components due to thermal energy.

[0007] In a third embodiment, a non-transitory computer-readable medium includes executable instructions that, when executed by a processor, cause the processor to: provide heating, cooling, or a combination thereof to a turbomachine via a first heat transfer conduit and a second heat transfer conduit included in a heat transfer system, wherein the second heat transfer conduit is disposed on the turbomachine adjacent to the first heat transfer conduit. The instructions also cause the processor to: control the heating, cooling, or a combination thereof of the turbomachine via a controller operatively coupled to the heat transfer system to minimize or eliminate position changes, structural changes, or a combination thereof in one or more turbomachine components due to thermal energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] These and other features, aspects, and advantages of the subject matter of the present invention will be better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters represent like parts throughout the drawings, wherein:

[0009] Figure 1 is a side elevational block diagram view of an embodiment of a turbine having a thermal management system;

[0010] Figure 2 is a front and rear elevational block diagram view of an embodiment of a turbine having a thermal management system;

[0011] Figure 3 is Figure 1 and Figure 2 a block diagram of an embodiment of a gas turbine system having a multistage axial compressor;

[0012] Figure 4 is a side view of an embodiment of a gas turbine engine showing an internal plume of hot air;

[0013] Figure 5 is a schematic view of an embodiment of two heat transfer systems that may be disposed on a bottom section of a housing of a turbomachine;

[0014] Figure 6 is a perspective view depicting an embodiment of a heating blanket of one of the heat transfer systems;

[0015] Figure 7 is a front view of a block diagram showing an embodiment of conduits that may be used to operatively and communicatively couple an embodiment of a heat transfer system to a controller;

[0016] Figure 8 is a bottom view of an embodiment of a housing or casing having a set of two heat transfer conduits disposed in a circumferential strip around a casing area;

[0017] Figure 9 is Figure 9Side view of an embodiment of a housing or casing having a set of two heat transfer conduits disposed in a circumferential strip around a casing region;

[0018] Figure 10 Front view of an embodiment of the enclosed heat transfer conduits and adjacent sensors;

[0019] Figure 11A Bottom block diagram depicting the region (e.g., bottom of the casing) heated by two heating elements; and

[0020] Figure 11B Bottom block diagram showing the region (e.g., bottom of the casing) heated by a heating element, where phases A, B, and C have been intertwined. DETAILED DESCRIPTION

[0021] One or more specific embodiments of the subject matter of the present invention will be described below. To provide a concise description of these embodiments, not all features of an actual implementation may be described in the specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Additionally, it should be understood that such development work may be complex and time-consuming, but would still be a routine task of design, fabrication, and manufacture for those of ordinary skill in the art who would benefit from this disclosure.

[0022] When introducing elements of the various embodiments of the subject matter of the present invention, the articles "a", "an", "the", and "said" are intended to mean that there is one or more of the elements. The terms "comprising", "including", and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0023] The disclosed embodiments include heat transfer or thermal management systems that can be used by a variety of turbomachines. For example, a gas turbine system can include a thermal management system that can provide heating and / or cooling to certain components (e.g., the casings or housings of compressors, burners, turbines, etc.) during certain operations, such as shutdown operations. For example, during a shutdown operation, the lower housing of a gas turbine system can cool faster than the upper housing, which can cause expansion / contraction of certain components and consequent casing deformation. The thermal management system can provide heating and / or cooling to compensate for the thermal differential, thereby improving the operation of the turbomachine.

[0024] In one embodiment, the thermal management system includes heat transfer conduits (e.g., wires, pipes) that can be symmetrically routed to improve heat transfer reliability. The heat transfer conduits can include certain ranges of spacing between the heat transfer conduits themselves and certain ranges of spacing relative to certain components (e.g., the housing) of the turbomachine to improve heat transfer. The thermal management system can also include reflective foil and insulating covers. In addition to controlling the spacing between the heat transfer conduits and the insulating material, the reflective foil or other wrap can also be used to moderately isolate shorter heat transfer conduits from attached sensors (e.g., thermocouples). The thermal management system can be fastened to the turbomachine using single fastener technology.

[0025] In some embodiments, the thermal management system can include a controller communicatively coupled to one or more sensors, such as thermocouples, disposed in various parts of a turbomachine (e.g., a gas turbine system). The controller is operably coupled to one or more heating and / or cooling systems disposed in the turbomachine. The controller can use zone control to control heating and / or cooling of one or more zones in the turbomachine.

[0026] In one embodiment, the zone control can include dual redundant application of heating / cooling and / or dual redundant sensing. For example, if there is a maintenance issue with the heating / cooling equipment in a second zone, the first zone adjacent to the second zone can provide heating and / or cooling redundancy for the second zone. Similarly, a first sensor disposed in a first zone, region, or subsystem of the turbomachine can provide redundancy for a second sensor disposed in a second zone, region, or subsystem. For example, the first sensor can be disposed in a first subsystem and the second sensor can be disposed in a second subsystem, but by using the techniques described herein, if the second sensor is not working, the first sensor can provide data for determining the condition of the second subsystem. By providing dual redundant application of heating / cooling and / or dual redundant sensing for the heating system, the techniques described herein can increase the service life and efficiency of the turbomachine.

[0027] The mechanical systems described herein can achieve more uniform heating of certain components (e.g., the housing) and provide redundancy during heating operations. For example, heat conduits can be provided adjacent to other conduits. In one example, two conduits can be parallel to each other but offset by a small amount (e.g., between 0.25 inches and 5 inches). The conduits can also be adjacent and / or contiguous to the housing. For example, the conduits can be from 0 inches to 0.2 inches away from the housing. Reflective foil can be used to aid in heat transfer, for example, by reflecting radiation and thus reducing heat transfer that can occur by radiation. In certain embodiments, "wraps" can be used to partially or fully encapsulate the conduits and / or temperature sensors to improve temperature delivery and / or measurement, as further described below.

[0028] Now turning toFigure 1 , this figure is a side view of a block diagram of a turbomachine 10 having a top shell 11 and a bottom shell 13. A plane 15 separates the top shell 11 from the bottom shell 13. Although the turbomachine 10 is described below with reference to a gas turbine system, the turbomachine 10 can be any type of turbomachine, such as a turboexpander, a compressor, a rotary pump, a wind turbine, a hydraulic turbine, etc. In the illustrated embodiment, a thermal management system 17 is also shown. The thermal management system 17 can include a control system 14 (also referred to herein as "controller 14"), sensors 16, and a heat transfer system 18. For example, the sensors 16 can be communicatively coupled to the control system 14 and transmit signals representative of temperature. Thus, the sensors 16 can include thermocouples, infrared sensors, thermistors, etc. In certain embodiments, the sensors 16 can be arranged to provide signals representative of temperature in various zones of the housing 11 and / or 13. Additionally, the sensors 16 can be sensors used by other systems of the turbomachine 10. For example, the sensors can be used for creep detection, clearance measurement, stress measurement, etc.

[0029] The controller 14 is operatively coupled to the heat transfer system 18 to provide heating and / or cooling of certain zones within the turbomachine 10, such as locations on the top shell 11 and the bottom shell 13. The heat transfer system 18 can include heating blankets (e.g., electric heating blankets) suitable for generating heat and / or dissipating heat, heat exchangers (e.g., fluid-based heat exchangers), refrigeration systems, radiant heating systems, etc.

[0030] In use, the turbomachine 10 can experience thermal gradients. For example, when the turbomachine 10 is a gas turbine system, the bottom shell 13 can cool faster than the top shell 11 during shutdown. That is, as heat rises due to buoyancy, the bottom shell 13 can be at a lower temperature compared to the top shell 11, which can result in undesirable effects. For example, the bottom shell 13 can contract while the top shell 11 can expand, which can cause the housing to bend. The controller 14 can receive a plurality of signals representative of the temperature at each sensor 16 from the sensors 16 and apply certain heating and / or cooling via the heat transfer system 18, as described in more detail below, to minimize or eliminate certain heating-related effects, such as housing bending. Thus, the controller 14 can include one or more processors 19 and a memory 21. The memory 21 can store computer code or instructions executable by the processor 19.

[0031] Figure 2 is an axial view of a block diagram of an embodiment of the turbomachine 10, which shows sensors 16 placed at various positions of the turbomachine 10. Since this figure includes elements Figure 1 similar to those in Figure 2Also depicted are sensors 16 disposed on the top shell 11, the bottom shell 13, and various locations of the turbomachine 10. In some embodiments, the sensor 16 can be used in conjunction with the thermal management system 17.

[0032] For example, when the turbomachine 10 is a gas turbine system, some sensors 16 can be used to provide temperature and / or other measurements during operation of the turbomachine 10. For example, the sensor 16 can include wheel space thermocouples, exhaust gas temperature thermocouples, compressor discharge temperature thermocouples, combustion temperature thermocouples, etc. Additionally or alternatively, sensors that measure clearances (e.g., rotor clearances, clearances between two or more components) can be used.

[0033] The heat transfer system 18 can also be disposed at various locations of the turbomachine 10. In one embodiment, the heat transfer system 18 can be disposed on the bottom shell 13 and used to heat the bottom shell 13 to provide more uniform heating to the top shell 11 and the bottom shell 13. That is, by heating the bottom shell 13 at one or more zones, one or more zones of the bottom shell 13 can be maintained at a temperature similar to that of the regions of the top shell 11, which would otherwise experience more heat without the techniques described herein. By maintaining a more optimized top-to-bottom temperature difference, the turbomachine 10 can, for example, experience a shutdown cycle with minimal or no clearance eccentricity.

[0034] In other embodiments, the heat transfer system 18 can be disposed on both the top shell 11 and the bottom shell 13. In these embodiments, the heat transfer system 18 on the top shell 11 can provide cooling, such as via a heat exchanger (e.g., a system with conduits that move a cooling fluid into a zone and out with a heated fluid to extract heat). By combining heating on the bottom shell 13 with cooling on the top shell 11, certain operations, such as turbine shutdown operations, can be improved while extending the life cycle of the device.

[0035] In other embodiments, the heat transfer system 18 can provide both heating and cooling, for example, by circulating a heated fluid and a cooling fluid based on the heat to be added or extracted. The heat transfer system 18 can be disposed on the outer shells 11, 13, or at any location of the turbomachine 10 that would benefit from heating and / or cooling during certain operations. In fact, the heat transfer system 18 can be disposed in various subsystems of the turbomachine 10 and is operatively coupled to the controller 14. The heat transfer system 18 can include an electrically heated "blanket", heat exchangers, heat exchangers, radiant heaters, etc.

[0036] It may be advantageous to describe an embodiment of a turbomachine, namely a gas turbine system. Thus, Figure 3Is a block diagram of an embodiment of a turbomachine 10 as a turbine system, which may include a gas turbine engine 12 and a thermal management system 17. A controller 14 is shown communicatively coupled to various sensors 16 and a heat transfer system 18 disposed in various components of the gas turbine engine 12. Signals received via the sensors 16 can be used to derive thermal operations that can be performed via the heat transfer system 18. The illustrated gas turbine engine 12 includes a compressor 20 (e.g., a multi-stage axial compressor or compressor section), a turbine 22 (e.g., a multi-stage turbine or turbine section), and a fuel nozzle 24 coupled to one or more burners 26 (e.g., a burner section). The compressor 20 and the turbine 22 can each have any number of rows or orders of magnitude of rotor blades and stator vanes (e.g., 1 to 20).

[0037] In operation, the compressor 20 is configured to compress a compressible fluid (e.g., a gas such as air, oxygen, and / or exhaust gas) and deliver the compressed fluid to the fuel nozzle 24 and / or the burner 26. While the compressible fluid can include any suitable gas, as a non-limiting example, the following discussion will generally refer to the compressible fluid as an oxidizer (e.g., air). The fuel nozzle 24 is configured to supply fuel (e.g., from one or more fuel sources) into one or more burners 26 (e.g., into a combustion chamber), and the one or more burners combust the fuel with the oxidizer (e.g., air) to generate high-temperature combustion gases to drive the turbine 22.

[0038] The fuel nozzle 24 can be designed as a premix fuel nozzle 24 and / or a diffusion fuel nozzle 24. Within the fuel nozzle 24, the premix fuel nozzle 24 mixes the fuel with the oxidizer (e.g., air) to produce a premixed flame. When the fuel and air are introduced into the combustion zone separately, the diffusion fuel nozzle 24 does not premix the fuel with the oxidizer, thus producing a diffusion flame. Regardless of the type of flame, the hot combustion gases flow from the burner 26 into the turbine 22, thereby driving the rotation of one or more stages of the turbine blades coupled to the turbine rotor and shaft 30 along the axis 32. Eventually, the hot combustion gases leave the turbine 22 through an exhaust outlet 28 (e.g., an exhaust stack, an exhaust end).

[0039] In the illustrated embodiment, the shaft 30 is coupled to the compressor 20 and the load 36 such that the rotation of the shaft 30 also drives the rotation of the compressor 20 and the load 36. The compressor 20 can draw in an oxidizer (e.g., air) through an inlet 34, which can include a filter, a thermal control system, or any other pretreatment system. The load 36 can include a generator, a rotating machine, a propulsion system of a vehicle, or any other suitable device. It should be noted that the thermal management systems and methods described herein are also applicable to a two-shaft (or more-shaft) turbine in which the load is coupled to a power turbine, which can be independent of the compressor and / or the gas generator.

[0040] During shutdown, the heat dissipation rate of the bottom case 13 can be faster than that of the top case 11. Heat from the bottom case 13 rises towards the top case 11, as shown by the arrow 50 in Figure 4 . More specifically, Figure 4 is a side view of an embodiment of a gas turbine engine 12 (shown in Figure 3 ), showing an internal plume of hot air 50 that may flow upward from the bottom case 13 towards the top case 11, for example, during a shutdown operation. After shutdown, the bottom case 13 can immediately be at approximately the same temperature as compared to the top case 11, and an air flow 52 (e.g., a stack exhaust flow) can enter the gas turbine engine 12 through the intake section 34, pass through the compressor section 20, the nozzle / burner sections 24, 26, the turbine section 22, and be discharged through the exhaust section 28. Over time, heat can be transferred from the bottom case 13 into the top case 11 via the internal plume of hot air 50.

[0041] To maintain a more even temperature, it would be advantageous to heat the bottom case 13 and / or cool the top case 11. Thus, the thermal management system 17 (shown in Figure 1 ) can apply heat and / or remove heat from certain areas, as shown in Figure 5 . More specifically, Figure 5 is a schematic view of an embodiment of two heat transfer systems 18 that can be disposed on sections of the bottom case 13. For example, the heat transfer system 18 disposed on the bottom case 13 of the compressor section 20 includes a heating and / or cooling zone in which two heating / cooling units 1, 2 are provided. The heat transfer system 18 disposed on the bottom case 13 of the turbine section 22 includes two heating and / or cooling zones: a first zone in which a heating / cooling unit 3 is provided, and a second zone in which heating / cooling units 4, 5, 6, and 7 are provided. In fact, a zone can include one or more sub-zones, where each sub-zone corresponds to a heating / cooling unit.

[0042] For example, based on a thermal study analyzing the materials, thickness, manufacturing data, and / or geometry of the outer casing (e.g., casings 11, 13), zones and sub-zones can be selected to heat and / or cool subsystems (e.g., the rotor 30, components of the intake section 34, the compressor section 20, the fuel nozzle 24, the burner 26, the turbine 22, the exhaust section 28, etc.) in order to determine the heat flow through the gas turbine engine 12 or otherwise model it. Then the heat flow can be used to determine the zones and sub-zones for heating and / or cooling. The heat flow can also be used to determine the heating schedule for the heating and / or cooling zones and / or sub-zones. For heating purposes, each heating / cooling unit can include an axial heating "strip" that can use electrical heating. Other heating embodiments can include heat exchangers, heat recovery units, radiant heaters, microwave heating elements, etc. For cooling purposes, heat exchangers, refrigeration systems, etc. can be used.

[0043] In some embodiments, each subzone (or zone having a single subzone) can be independently controlled by the controller 14. That is, a heating and / or cooling schedule that may be different from other subzones can be provided for each subzone (or zone having a single subzone). In some embodiments, some subzones (e.g., adjacent subzones) may follow the same heating and / or cooling schedule. The heating and / or cooling schedule can be used to determine the number of heating and / or cooling applications at a given point in time (e.g., the time after shutdown begins).

[0044] Zones and / or subzones can also be used to provide redundant operation. For example, if an operational problem occurs with a heating / cooling unit, an adjacent heating / cooling unit can enter a redundant mode, where the adjacent heating / cooling unit can provide additional heating or cooling to compensate for the heat loss of heating or cooling of the heating / cooling unit experiencing the problem. In some embodiments, a redundant mode heating and / or cooling schedule can be provided, which can be derived based on a thermal analysis of the zone and / or subzone where the heating / cooling unit problem (e.g., heating / cooling unit failure) is occurring.

[0045] That is, a redundant mode heating and / or cooling schedule can be derived that increases the heating and / or cooling of a given workspace and / or subzone based on the problem occurring in adjacent zones and / or subzones. For example, the heating and / or cooling schedule can be used to: apply heating and / or cooling via a time-based mode without using sensors. That is, a heating and / or cooling blanket can be turned on (at full power, partial power, or a desired power level) for a given time to provide heating and / or cooling, and then turned off without sensing the temperature. Thus, the controller 14 can switch from normal operation to redundant operation, for example, by switching to use the redundant mode heating and / or cooling schedule.

[0046] Figure 6 is a perspective view depicting a heating blanket embodiment of one of the heat transfer systems 18, showing the use of contour and shape design to more conformally fit the heat transfer system 18 to an external portion of, for example, a housing such as the top shell 11 or the bottom shell 13. In the depicted embodiment, the cutout 60 can provide quick access to certain components (e.g., protruding nozzles, mechanical inspection ports). The contour 62 can conformally follow the underlying geometry of the housing 11 and / or 13 to improve the fit (e.g., by more closely following the geometries of multiple components to increase coverage) and thus provide enhanced heat transfer.

[0047] In some embodiments, the heat transfer system 18 may be added after the turbomachinery 10 is installed. For example, the heat transfer system 18 may be provided as a post-installation kit or as an upgrade kit and installed in place. For example, the illustrated heating blanket embodiment of the heat transfer system 18 may be placed on the outer walls of the housings 11 and / or 13 and secured via fasteners such as straps, nuts and bolts, welds, adhesives, etc. The sensors 16 and the conduits for operating the heating elements may then be connected to the controller 14. For example, various conduits that may be used are described below Figure 7 describes the various conduits that may be used.

[0048] Figure 7 is a front view of a block diagram depicting an embodiment of conduits 70, 72, and 74 that may be used to operatively and communicatively couple an embodiment of the heat transfer system 18 (e.g., a heating blanket embodiment) to the controller 14 ( Figure 1 shown). In the illustrated embodiment, the conduit 70 may be used to operate the heating blanket 76. For example, sending electricity through the conduit 70 may heat the heating element 78 included in the heating blanket 76. The insulation layers 80 and 82 may be used to retain the added heat.

[0049] In use, the controller 14 may receive a signal representing temperature in a region of the housing from the sensor 16 (e.g., the region is shown as being embedded in a section of the bottom housing 13). Thus, the controller 14 may adjust the electricity through the conduit 70 to increase or decrease the heat provided by the heat transfer system 18. Although two insulation layers 80 and 82 are shown, one, three, four, or more layers may be used. The sensor 16 senses the temperature delivered via the heating blanket 76, e.g., to prevent the heating blanket 76 itself from overheating, and transmits such signals to the controller 14 via the conduits 72, 74. It should be understood that the illustrated heating blanket is merely one embodiment of the heat transfer system 18, and other embodiments may include heat exchangers and the like adapted to add heat to a region.

[0050] Now turning to Figure 8 , this figure is a bottom view of an embodiment of a housing or casing 150 having a set of two heat transfer conduits 152, 154 disposed in a circumferential strip around a region of the casing 150. The casing 150 may be formed, for example, from the housings 11 and / or 13 as described above with reference to the appended Figure 1 、 Figure 2 and Figure 5 described. The heat transfer conduits 152 and / or 154 may be pipes adapted to move fluid or may be heating elements (e.g., wires), such as the heating element 78 described above with reference to Figure 7 described.

[0051] In the depicted embodiment, the heat transfer conduits 152, 154 are disposed side by side with respect to each other. That is, the heat transfer conduit 152 may follow the same profile (e.g., curvature) as the heat transfer conduit 154, and the heat transfer conduits 152, 154 may be parallel with respect to each other and / or may be offset from each other by a certain amount. In one embodiment, the heat transfer conduit 152 may be the same as the heat transfer conduit 154 (e.g., having the same dimensions and shape), but may be offset and / or placed parallel with respect to the heat transfer conduit 154. For example, the heat transfer conduits 152, 154 may be spaced from each other between 0.25 inches and 5 inches. The heat transfer conduits 152, 154 may be placed in certain profiles (e.g., blanket profile, housing profile) and may thus include curved portions. In certain embodiments, the conduits 152, 154 may cover a specific area in the circumferential direction (e.g., an arc area between, such as + or - 45°) to cover a zone or sub-zone such that the absence of the zone or sub-zone does not cause the housing or enclosure to bend laterally.

[0052] In the depicted embodiment, the heat transfer conduits are operatively coupled to the controller 14 via circuitry 156, such as a pulse width modulation (PWM) circuitry 156 and more specifically a silicon controlled rectifier (SCR)-based circuitry. In operation, the PWM circuitry 156 may deliver three-phase power to each of the heat transfer conduits 152, 154, for example, at a voltage between 360 volts - 660 volts. Due to lateral symmetry, if one of the heat transfer conduits 152, 154 experiences a heating problem, the other heat transfer conduit 152, 154 is configured to provide redundancy in operation.

[0053] That is, if the heat transfer conduit 152 or 154 fails, the other heat transfer conduit 152 or 154 may still provide sufficient heat to continue the operation of the gas turbine engine 12 (e.g., a shutdown operation). For example, if the heat transfer conduit 152 fails, the adjacent heat transfer conduit 154 may adjust the heating schedule (as described above) to compensate for the absence of the heat transfer conduit 152 and continue operation to prevent rotor friction. Although the depicted embodiment shows two heat transfer conduits 152, 154, three, four, five, six, or more heat transfer conduits may be disposed symmetrically with respect to each other laterally. It should also be noted that the heat transfer conduits 152, 154 (or more) may be arranged to cover the desired areas of the housing 150, such as the zones and / or sub-zones described in the figures above.

[0054] Now turning to Figure 9 , this figure is a front cross-sectional view of an embodiment of the housing 150, which shows the heat transfer conduit 152, as well as other details of other elements of the heat transfer system as arranged around the housing 150. In the depicted embodiment, the heat transfer conduit 152 is disposed at a distance d1 from the housing 150. The distanced2 It can also be used as the intermediate distance that separates the heating elements of the heat transfer conduit 152 from each other (or from the heat transfer conduit 154), as shown in the figure. The distance d 1 can be between 0 inches and 0.2 inches. The distance d2 can be between 0.25 inches and 5 inches.

[0055] The reflective foil layer 160 is also depicted. The reflective foil layer 160 can reduce heat transfer by radiation by reflecting the thermal radiation back to the housing 150. The reflective foil layer 160 can also control the spacing between the insulation layer 162 and the heat transfer conduit 152. The heat transfer conduits 152 (optionally, 154) of the thermal management system can be fastened to the housing 150 via fasteners 164 (such as nuts and bolts, screws, etc.).

[0056] Figure 10 FIG. depicts an embodiment of a "wrap" portion 172 disposed within the heat transfer conduit 152. In the depicted embodiment, a single wrapper 173 can be used. For example, the wrapper 173 can completely encapsulate both the heat transfer conduit 152 and the sensor 16 (such as a thermocouple) in a portion of the heat transfer conduit 152. The wrapped length of the heat transfer conduit 152 can be between 1 inch and 5 inches, and the sensor 16 and the heat transfer conduit 152 can be spaced apart from each other within the wrapper 173 by a distance d3 .

[0057] In one embodiment, each heat transfer conduit 152 can include a wrap portion 172 disposed in the middle of the heat transfer conduit 152. For example, if the length of the heat transfer conduit 152 is 6 feet, the wrap portion 172 can be disposed in the middle, such as approximately three feet from the starting point of the heat transfer conduit 152. In other embodiments, multiple wrap portions 172 can be disposed along the length of the heat transfer conduit 152. In some embodiments, each of the multiple wrap portions 172 can be disposed to divide the heat transfer conduit 152 into generally equal or equal segments between the wrap portions 172.

[0058] In the depicted embodiment, the wrapper 173 can cover all sides of the heat transfer conduit 152 in a single layer and can also encapsulate the sensor 16. In use, the wrap portion 172 can improve the temperature sensing of the heat transfer conduit 152. For example, if the sensor 16 is not wrapped, the sensor 16 may be less accurate in sensing the heat transfer conduit 152 because the applied heat can be transferred into the housing, and thus the sensor 16 can obtain a lower heat reading. Accordingly, the techniques described herein provide improved thermal manipulation, which is applicable to increasing the housing life and minimizing and / or eliminating housing bending or deformation.

[0059] Figure 11AA bottom block diagram depicting an area 200 (e.g., the bottom of a housing) heated by two heating elements is shown. More specifically, area 200 is bounded by two vectors 202, 204 that may intersect the bottom dead center (BDC) of the housing, having an angle α of approximately 90°, such that area 200 provides coverage of approximately 45° from the middle of the housing BDC on either side of the BDC (e.g., sides 206, 208). In some embodiments, the angle α may be between 45° and 180°.

[0060] The heating elements may be three-phase heating elements having a phase A, a phase B, and a phase C. In the depicted embodiment, 1A depicts phase A of heating element 1, 1B depicts phase B of heating element 1, and 1C depicts phase C of heating element 1. Similarly, 2A depicts phase A of heating element 2, 2B depicts phase B of heating element 2, and 2C depicts phase C of heating element 2. In some embodiments, each of the phases A, B, and C may be controlled independently, while in other embodiments, the phases A, B, and C may be controlled as a whole. In the latter embodiment, if it is found that phase A, B, or C is not functioning as needed, then all phases of the heating element may be turned off.

[0061] Figure 11A Lateral thermal symmetry is shown, as any problems with the heater (or phases of the heater) should not result in uneven lateral heating (or when the heater is a cooling system such as a cooling fluid conduit, should not result in uneven lateral cooling). For example, turning off heater 1 only results in less overall heating, but the lateral heating (e.g., heating along the Y-axis) is not uneven or asymmetric.

[0062] Lateral thermal symmetry is provided because the heater can span completely from one side (e.g., side 206) to the other side (e.g., side 208). That is, if a heater or heater phase is turned off, no side should heat (or cool) in a different manner than the other side. In fact, the techniques described herein do not heat (or cool) via "patches" covering area 200, but can heat (or cool) uniformly from one side to the other, thus maintaining lateral symmetry. In embodiments where all three phases are controlled together, it may be advantageous to interleave certain phases, as Figure 11B shown.

[0063] More specifically, Figure 11B an embodiment of heaters 1, 2 is shown where the phases A, B, and C have been interleaved. In the depicted embodiment, phase A of the second heater is set after phase A of the first heater, rather than phase B of the first heater after phase A of the first heater. In Figure 11BIn the illustrated embodiment, the sequence is now 1A, 2A, 1B, 2B, 1C, and then 2C. Thus, if the first heater (phases 1A, 1B, 1C) is turned off, then, for example, the second heater (phases 2A, 2B, 2C) can heat the housing area 200 more evenly. It should also be understood that in other embodiments, more than two heaters may be used, and when three heaters (or coolers) are used, the phases are interwoven in a similar manner, such as 1A, 2A, 3A, 1B, 2B, 3B, 1C, 2C, 3C.

[0064] This written description uses examples to disclose the subject matter, including the best mode, and also enables any person skilled in the art to practice the subject matter, including making and using any device or system and performing any incorporated method. The scope of the patentable subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are determined to be within the scope of the claims if they have structural elements that are the same as the literal language of the claims, or if they include equivalent structural elements that are not materially different from the literal language of the claims.

Claims

1. A thermal management system (17), the thermal management system comprising: a heat transfer system (18) configured to provide heating, cooling, or a combination thereof to a turbomachine (10), the heat transfer system (18) comprising: a first heat transfer conduit (152); and a second heat transfer conduit (154) disposed adjacent to the first heat transfer conduit; a thermal sensor (16) disposed adjacent to a section of the first heat transfer conduit (152); and a controller (14) operatively coupled to the heat transfer system (18) and communicatively coupled to the thermal sensor, the controller being configured to control heating, cooling, or a combination thereof of the turbomachine (10) via the heat transfer system (18) at least based on a reading from the thermal sensor, wherein the section of the first heat transfer conduit comprises an insulating wrap that encapsulates only the section of the first heat transfer conduit and the thermal sensor and is in direct contact with the thermal sensor and the section of the first heat transfer conduit.

2. The system according to claim 1, wherein the second heat transfer conduit (154) is disposed parallel to the first heat transfer conduit (152).

3. The system according to any one of the preceding claims, wherein the first heat transfer conduit (152) is offset from the second heat transfer conduit (154) by a distance between 0.25 inches and 5 inches.

4. The system according to any one of the preceding claims, wherein the first heat transfer conduit (152) comprises a first electric heating element (78), and the second heat transfer conduit (154) comprises a second electric heating element (78); and wherein the controller (14) is configured to independently control the first electric heating element (78) and the second electric heating element (78).

5. The system according to claim 4, wherein the controller (14) is configured to provide redundant operation by adjusting control of the first electric heating element (78) when the second electric heating element (78) is inoperative, or by adjusting control of the second electric heating element (78) when the first electric heating element (78) is inoperative.

6. The system according to claim 1, wherein the wrap (173) comprises a single layer wrap.

7. The system according to any one of the preceding claims, wherein the heat transfer system (18) comprises a radiation shield layer (160) radially disposed outside the first heat transfer conduit (152) and the housing (150) of the turbomachine (10).

8. The system according to any one of the preceding claims, wherein the turbomachine (10) comprises a gas turbine engine (12); and wherein the controller (14) is configured to control a shutdown operation of the gas turbine engine (12) and to control the heat transfer system (18) during the shutdown operation.

9. A method, the method comprising: Heating, cooling, or a combination thereof is provided to the turbomachine (10) via a first heat transfer conduit (152) and a second heat transfer conduit (154) included in a heat transfer system (18), wherein the second heat transfer conduit (154) is disposed adjacent to the first heat transfer conduit (152) on the turbomachine (10), and wherein a section of the first heat transfer conduit includes an insulating wrap that encapsulates only the section of the first heat transfer conduit and a heat sensor and is in direct contact with the heat sensor and the section of the first heat transfer conduit; and Heating, cooling, or a combination thereof of the turbomachine (10) is controlled via a controller (14) operatively coupled to the heat transfer system (18) to minimize or eliminate a positional change, a structural change, or a combination thereof in one or more components of the turbomachine (10) due to thermal energy, wherein the controller uses at least a reading from the heat sensor to control the heating, cooling, or a combination thereof.

10. The method according to claim 9, wherein the second heat transfer conduit (154) is disposed parallel to the first heat transfer conduit (152), offset relative to the first heat transfer conduit (152), or a combination thereof.

11. The method according to claim 9 or 10, wherein the first heat transfer conduit (152) includes a first electric heating element (78), and the second heat transfer conduit (154) includes a second electric heating element (78); and wherein the controller (14) is configured to independently control the first electric heating element (78) and the second electric heating element (78).

12. The method according to claim 11, including providing redundant operation via the controller (14) by adjusting the control of the first electric heating element (78) when the second electric heating element (78) is inoperative, or by adjusting the control of the second electric heating element (78) when the first electric heating element (78) is inoperative.

13. The method according to any one of claims 9 to 12, wherein at least the first heat transfer conduit (152) provides lateral symmetry for heating, cooling, or a combination thereof of a housing (150) of the turbomachine (10).

14. The method according to any one of claims 9 to 13, wherein the length of the section is between 0.5 inches and 10 inches.

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