Heat exchanger with cooling structure

Abstract

A heat exchanger and a method for forming the heat exchanger, the heat exchanger including a cooling structure, the cooling structure including at least one cell having a set of walls having a thickness, the set of walls defining a fluidly separated conduit having a plurality of openings, each of the plurality of openings having a hydraulic diameter, wherein an average fluid temperature (T f ) to a material temperature limit (T m ) ratio (T f / T m ) is greater than 0 and less than or equal to 1.25 (0 < T f / T m ≤ 1.25), and wherein the thickness (T) and the hydraulic diameter (D H ) are related to one another by an equation to define a cell performance factor (UCPF).

Description

[0001] Cross-references to related applications

[0002] This application is a continuation of and claims priority to U.S. Application No. 17 / 716,712, entitled “Heat Exchanger with Cooling Structure,” filed April 8, 2022, which is expressly incorporated herein by reference in its entirety. Technical Field

[0003] This topic generally relates to a heat exchanger with cooling conduits. Background Technology

[0004] A gas turbine engine typically consists of a fan and a turbine. The turbine typically includes an inlet, one or more compressors, a combustor, and at least one turbine. The compressor compresses air directed to the combustor, where it is mixed with fuel. The mixture is then ignited to produce hot combustion gases. The combustion gases are directed to the turbine, which extracts energy from the combustion gases to power the compressor and to generate useful work to propel an aircraft in flight or power a load (such as a generator). Attached Figure Description

[0005] The complete and enabling disclosure of this disclosure, including its best mode, is set forth in the specification with reference to the accompanying drawings, for those skilled in the art, wherein:

[0006] Figure 1 This is a perspective view of an aircraft including at least one heat exchanger, according to aspects of this disclosure.

[0007] Figure 2 yes Figure 1 A schematic cross-sectional view of the heat exchanger, including cells.

[0008] Figure 3 yes Figure 2 A magnified view of the cells, including cell borders and shading to distinguish layered volumes.

[0009] Figure 4 yes Figure 3 A magnified view of a single cell, 132, where the shadow and borders have been removed.

[0010] Figure 5 It is a three-dimensional side view of continuous cells, showing the cooling fluid flow through the first set of conduits and the heating fluid flow through the second set of conduits.

[0011] Figure 6 It shows Figure 6 The bifurcation path of the heated fluid flow in the middle.

[0012] Figure 7 It shows Figure 6The branching paths of the cooling fluid flow in the medium.

[0013] Figure 8 A method is shown for cooling an engine component having at least one cell based on a cell performance factor (UCPF) associated with at least one cell.

[0014] Figure 9 This is a flowchart illustrating a method for forming cells.

[0015] Figure 10 It is a graph showing the UCPF along the y-axis and the temperature ratio (TR) along the x-axis. Detailed Implementation

[0016] The aspects disclosed herein relate to cooling structures located within engine components, and more specifically, to cells, wherein the performance of the cells is a function of geometric parameters driving heat transfer and pressure drop. For illustrative purposes, this disclosure describes cooling structures defining at least a portion of a heat exchanger, which may be located within any suitable part of an aircraft, including but not limited to engines, avionics systems, or any aircraft system requiring the transfer of heat from one location to another. However, it should be understood that the aspects disclosed herein are not limited thereto and may have general applicability in non-aircraft applications, such as other mobile applications and non-mobile industrial, commercial, and residential applications.

[0017] Reference will now be made in detail to the cooling structure, particularly to the cells that define at least a portion of the heat exchanger, one or more examples of which are shown in the accompanying drawings. Detailed descriptions use numbers and letters to refer to the features in the drawings.

[0018] The term "exemplary" as used herein means "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as superior to or advantageous to other implementations. Furthermore, unless specifically stated otherwise, all embodiments described herein should be considered exemplary.

[0019] As used herein, the terms “first,” “second,” and “third” are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of the individual components.

[0020] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle, and specifically to the normal operating posture of the gas turbine engine or vehicle. For example, in the case of a gas turbine engine, "front" refers to the position closer to the engine inlet, while "rear" refers to the position closer to the engine nozzle or exhaust port.

[0021] As used herein, the term "upstream" refers to the direction opposite to the direction of fluid flow, and the term "downstream" refers to the direction in the same direction as the direction of fluid flow. The terms "front" or "forward" indicate being in front of something, and "back" or "rear" indicate being behind something. For example, when used for fluid flow, front / forward can indicate upstream, while back / rear can indicate downstream.

[0022] The term "fluid" can refer to a gas or a liquid, or a multiphase system. The term "fluid connectivity" refers to the ability of fluids to establish connections between specified areas.

[0023] Furthermore, as used herein, the term "radial" or "radially" refers to a direction away from a common center. For example, in the overall context of a turbine engine, radial refers to the direction along a ray extending between the engine's central longitudinal axis and its outer circumference.

[0024] All directional references (e.g., radial, axial, proximal, distal, up, down, upward, downward, left, right, lateral, front, rear, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, forward, backward, etc.) are for identification purposes only to aid the reader's understanding of this disclosure and do not constitute a limitation, particularly on the position, orientation, or purpose of the aspects of this disclosure described herein. Unless otherwise stated, connection references (e.g., attachment, coupling, connection, and joining) are to be interpreted broadly and may include intermediate structural elements between sets of elements and relative movement between elements. Therefore, a connection reference does not necessarily imply that two elements are directly connected and have a fixed relationship with each other. Exemplary figures are for illustrative purposes only, and the dimensions, positions, order, and relative sizes reflected in the accompanying figures may vary.

[0025] Unless the context clearly specifies otherwise, the singular forms “a,” “an,” and “the” include plural references. Furthermore, as used herein, the term “group” or “set” of elements can refer to any number of elements, including only one.

[0026] As used in this article, “base” refers to any wall of an engine component.

[0027] As used in this article, a "cell" is a conduit block formed by openings connected by walls. Each cell consists of the wall thickness (t) and the hydraulic diameter (D) of the opening within the cell. H The geometry of both is used to define them. Figure 4 and Figure 5 These are all representative illustrations of cells.

[0028] As used in this article, “thickness” (t) refers to the thickness of the wall that defines the cell.

[0029] As used in this article, “diameter” (D) HThe term "hydraulic diameter" refers to the hydraulic diameter of the opening within a cell. Hydraulic diameter is a commonly used term when dealing with flow in non-circular pipes and channels. When the cross-section is uniform along the length of the pipe or channel, it is defined as... Where “a” is the cross-sectional area of ​​the flow and “p” is the wetting perimeter of the cross-section.

[0030] As used in this article, “high” and “low” are descriptors related to the number of performance metrics described in this article.

[0031] The "pressure drop" on an obstacle refers to the change in fluid pressure that occurs when a fluid passes over an obstacle. Pressure drop is calculated as the difference between the static pressure of the fluid immediately upstream of the obstacle and the static pressure of the fluid immediately downstream of the obstacle, divided by the static pressure of the fluid immediately upstream of the obstacle, and expressed as a percentage.

[0032] As used in this article, “heat transfer” refers to a certain amount of energy that moves between at least two media in the form of heat.

[0033] As used in this paper, "solid volume fraction" is the ratio of the volume of solid material to the combined total volume of the solid and fluid domains. The solid volume fraction of a cell increases with increasing wall thickness and decreasing hydraulic diameter.

[0034] As used in this article, "average flow area" refers to the cross-sectional area traversed by the fluid flowing within a cell. The average flow area increases with increasing hydraulic diameter. Compared to a smaller hydraulic diameter, a higher average flow area corresponds to a lower pressure drop, but this comes at the cost of an increased amount of heat transfer that may occur in the heat exchanger.

[0035] The term "fluid temperature" (T) used in this article f () refers to the highest average operating temperature of the fluid flowing through the heat exchanger described in this article.

[0036] As used in this article, “material temperature” (T) m The ultimate tensile strength (TST) refers to the ultimate tensile strength of a material, which decreases as temperature increases. The maximum temperature limit is the temperature at which the material's performance degrades, preventing the component from meeting its lifespan requirements. As used herein, the material temperature refers to the temperature at which the material's ultimate tensile strength decreases by 90% from its maximum value. Material temperature values ​​can be determined using an ultimate tensile strength curve or through testing.

[0037] As used in this paper, "UCPF" refers to the Cell Performance Factor. UCPF represents the combined effects of heat transfer, pressure drop, solids volume fraction, and average flow area. High heat transfer and / or low pressure drop will result in a higher UCPF value, while low heat transfer and / or high pressure drop will result in a lower UCPF value. There exists an optimal range where the solids volume fraction is high enough to indicate a large number of cells and heat transfer areas within a given volume, but not so high that small cells produce high pressure drops. By combining these effects, UCPF allows for the evaluation of trade-offs when determining the size of a cell heat exchanger for a given set of operating conditions and requirements.

[0038] During the operation of a gas turbine engine, various systems may generate a relatively large amount of heat. For example, significant amounts of heat may be generated during the operation of the thrust generation system, lubrication system, electric motor and / or generator, hydraulic system, or other systems. Therefore, cooling structures located within engine components in these various systems are advantageous in this field.

[0039] The cells of a heat exchanger can be modified and customized to meet various operating conditions of the aircraft, including startup, steady state, and maximum load. Optimizing a heat exchanger typically aims to meet the minimum heat transfer capacity from a relatively hot fluid to a relatively cold fluid, ensuring an acceptable pressure drop across the heat exchanger. Key factors to consider include the available volume of the cells and associated geometric constraints, the maximum pressure the cell walls must withstand, and operational limitations associated with the system or component providing the heat exchanger.

[0040] The inventors' practice is carried out by designing a heat exchanger (by way of a non-limiting example, a heat exchanger located in an aircraft cooling system). The heat exchanger is formed by an assembly of cells. The design of the cells is optimized using the Cell Performance Factor (UCPF) described herein, thereby optimizing the performance of the heat exchanger within the aircraft system.

[0041] Figure 1This is a perspective view of aircraft 10. The aircraft may include multiple engines, such as gas turbine engine 12. The aircraft also includes a fuselage 14, a cockpit 16 located within the fuselage 14, and wing assemblies 18 extending outward from the fuselage 14. A heat exchanger 20 may be located anywhere suitable within aircraft 10. For example, a heat exchanger 20 may be located within the engine components of the gas turbine engine 12 for cooling the engine components. Systems within aircraft 10 may also include heat exchangers 20. As a non-limiting example, the aircraft may include an auxiliary power unit (APU) system 22 and an avionics system 24. One or both of these systems may include a heat exchanger 20. It should be understood that any component or system within aircraft 10 that requires the transfer of heat from one medium to another may be provided with the heat exchanger 20 described herein.

[0042] Although the commercial aircraft 10 has been described, it is conceivable that the heat exchanger described herein can be used in any type of aircraft 10. Furthermore, although two gas turbine engines 12 have been shown on the wing assembly 18, it should be understood that any number of gas turbine engines 12 can be considered, including a single gas turbine engine 12 on the wing assembly 18, or even a single gas turbine engine mounted on the fuselage 14.

[0043] Figure 2 This is a schematic cross-sectional view of heat exchanger 20. Heat exchanger 20 may be coupled to a base 110 including a first wall 112 and a second wall 114. The first wall 112 may be spaced apart from the second wall 114 to define a wall gap 116. The base 110 may be any wall of the component, including but not limited to an inner wall, a top wall, a combustion liner wall, or the housing of the heat exchanger component itself. The first wall 112 may face the heat flow (Hf). The second wall 114 may face the cooling fluid flow (Cf). The cooling fluid flow (Cf) may be supplied from any cooling supply via exhaust air from a non-limiting example of the gas turbine engine 12. The heat flow (Hf) and the cooling fluid flow (Cf) may be gaseous, liquid, or two-phase flows.

[0044] A cooling structure 122 may be disposed within a base 110 between a first wall 112 and a second wall 114. The cooling structure 122 may include a set of fluid-separated cooling conduits 124 for exchanging heat between fluid flows within the conduits 124. A first set of conduits 124c and a second set of conduits 124h may be defined every other conduit 124. A relatively cooler fluid (C) may flow through the first set of conduits 124c relative to the second set of conduits 124h. A set of walls 138 may separate the fluids in the continuous first set of conduits 124c and the second set of conduits 124h.

[0045] At least one cell 132, indicated by a dashed line indicating cell boundary 146, may define a cooling structure 122. At least one cell 132 may be a plurality of cells 132 defining a complex network of conduits 124. A plurality of cells 132 may be replicated within an available envelope volume (V) to fill wall gaps 116, the available envelope volume (V) extending between a first wall 112 and a second wall 114, as shown. The number of cells 132 depends on the available envelope volume (V) at least partially defined by the first wall 112 and the second wall 114.

[0046] The cooling structure 122 may be defined by a set of walls 138 formed of a temperature-limiting material 118. The temperature limit of the material 118 is referred to herein as the material temperature (T). m Material temperature (T) m The value of ) is a known value associated with the material 118 that forms the cooling structure 122.

[0047] The materials used to form the substrate 110 and the cooling structure 122 can include, but are not limited to, steel, refractory metals (e.g., titanium), or nickel, cobalt, or iron-based superalloys, as well as ceramic matrix composites. The substrate 110 and the cooling structure 122 can be formed by a variety of methods, including, in non-limiting examples, casting, electroforming, or additive manufacturing methods such as direct metal laser melting. As used herein, an "additive manufacturing" part refers to a part formed by an additive manufacturing (AM) process, where the part is built layer by layer by the continuous deposition of material. AM is an appropriate name to describe the technique of building 3D objects by adding material layer by layer, regardless of whether the material is plastic, ceramic, or metal. AM technology can utilize computers, 3D modeling software (computer-aided design or CAD), machinery, and layered materials. Once a CAD model is generated, an AM device can read the data generated from the CAD model and place or add layers of liquid, powder, sheet, or other materials layer by layer to create a 3D object. It should be understood that the term "additive manufacturing" encompasses a wide range of technologies, including subsets such as 3D printing, rapid prototyping (RP), direct digital manufacturing (DDM), layered manufacturing, and additive construction. Non-limiting examples of additive manufacturing that can be used to form additively manufactured parts include powder bed melting, reduction photopolymerization, binder jetting, material extrusion, directional energy deposition, material jetting, or sheet lamination. It is also conceivable that the process used may include printing a substrate of a part using refractory metals, ceramics, or printable plastics, and then using that substrate to cast the part.

[0048] Figure 3For a single cell 132, a cell boundary 146 has been added for clarity. Although the illustration shows a typical nut shape or hexagonal prism, it should be understood that any repeating shape, including but not limited to pyramids, cubes, triangular prisms, etc., is acceptable. For clarity, the first and second group fluid separation conduits 124c, 124h are shown in a darker shade with the first group conduit 124c shown.

[0049] As can be seen more clearly, the first and second sets of fluid-separating conduits 124c and 124h are stratified volumes 147 separated by a set of walls 138. The first set of conduits 124c (darker shade) defines the cooling stratified volume 147c, while the second set of conduits 124h (lighter shade) defines the heating stratified volume 147h. The average temperature of the fluid defining the stratified volumes 147c and 147h is referred to herein as the fluid temperature (T). f Fluid temperature (T) f The value of ) is a representative snapshot of the entire fluid flowing within the cooling structure.

[0050] Go to Figure 4 , Figure 4 An enlarged view of a single cell 132, where shading and cell boundaries 146 have been removed. Cell 132 may include a set of walls 138 that divide the fluid-separating conduits 124 into a first set of conduits 124c and a second set of conduits 124h. This set of walls 138 may define a wall thickness (t). For each cell 132, the wall thickness (t) may be constant. Cell 132 may include varying wall thicknesses (t), in which case the wall thickness used for the calculations described herein will be the average wall thickness (t).

[0051] Each catheter 124 may include multiple openings 140. As a non-limiting example, a first set of catheters 124c may include a first opening 140a. As a non-limiting example, a second set of catheters 124h may include a second opening 140b.

[0052] The set of conduits 124 can define bifurcated flow paths 142 that diverge at the junction 144. As shown, the bifurcated flow paths 142 can be dichotomously or trichotomously branched. Each of the plurality of openings 140 can define a diameter (D). H Although shown as a circle, it should be understood that the multiple openings 140 can have any shape and diameter (D) H The diameter (D) is the hydraulic diameter. The diameter of the first opening, 140a... A The diameter of the first opening (140a) can be equal to the diameter of the other openings. For example, the diameter of the first opening (D) can be equal to the diameter of the other openings. A ) equals the diameter (D) of the second opening 140b. BThe diameter of the second opening 140b (D) B This is also equal to the diameter (D) of the exemplary opening 140. H And so on. It should be understood that the hydraulic diameter (D) H The opening can also vary among multiple openings 140, in which case the hydraulic diameter (D) used for the calculations described herein... H ) will be the average hydraulic diameter (D H ).

[0053] This paper will show the thickness (t) of the wall 138 of cell 132 and the diameter (D) of the opening 140 in cell 132. H ), material temperature (T) m ) and fluid temperature (T f The relationship between these parameters can be referred to as the cell performance factor, or simply "UCPF" in this paper. Similarly, the thickness (t) may vary slightly, so the thickness (t) used in the calculations described herein will be the average thickness (t).

[0054] Turn Figure 5 ,from Figure 3 The view of line V shows multiple layers of cells 132. It can be seen more clearly that the layered volume 147 is separated by a set of walls 138. The first set of conduits 124c (darker shade) defines the cooling layered volume 147c, while the second set of conduits 124h (lighter shade) defines the heating layered volume 147h.

[0055] Figure 6 The heated stratified volume 147h is shown, in which a set of walls 138 and most of the cooled stratified volume 147c have been removed. This more clearly illustrates the bifurcated flow path 142 along which the heated fluid (H) can flow. The bifurcated flow path 142 can be three-branched, as exemplarily shown by the arrows. Figure 6 This is a representation of heated fluid (H) flow without the structure of cell 132.

[0056] Figure 7 A cooled stratified volume 147c is shown, in which a set of walls 138 and most of the heated stratified volume 147h are removed. This more clearly illustrates the bifurcated flow path 142 along which the relatively cooler fluid (C) can flow. The bifurcated flow path 142 can be tetrafid (four separate fluid paths), as exemplarily shown by the arrows. It should be understood that the bifurcated path as described herein can be divided into more than four separate fluid paths. Figure 7 It is a representation of a relatively cold fluid (C) flow without the structure of cell 132.

[0057] Turn Figure 8This illustrates a method 200 for transferring heat from one location to another within an aircraft system having cell 132, based on the cell performance factor (UCPF). Method 200 may include introducing cooling fluid (Cf) at 202 into a first set of conduits 124c. The cooling fluid (Cf) may be introduced from another cell 132a (dashed line) adjacent to the illustrated cell 132, or from a cooling supply conduit. Consecutive cells 132, 132a may together define a cooling structure 122. Figure 2 It should be understood that multiple openings 140 fluidly connect consecutive cells 132, 132a to further define fluid-separated conduits 124c, 124h. The method may include cooling a second set of cooling conduits 124 at 204 by allowing a cooling fluid (Cf) to flow through the first set of cooling conduits 124c. The cooling fluid (Cf) is a relatively cool fluid (C) relative to the heated fluid (H) flowing through the second set of cooling conduits 124h. Therefore, heat (Q) can move from the heated fluid (H) to the cooling fluid (Cf). It should be understood that, depending on the relative temperature of the surrounding environment, both fluids can be present in the cooling structure 122 (…). Figure 2 Cooling fluid flow (Cf) at any location within the system. For example, fluid flowing in the second set of cooling conduits 124h, once cooled by the fluid in the first set of cooling conduits 124, can then be used to cool other components within the system.

[0058] At 206, the cooling fluid flow (Cf) may be branched at junction 144. At 208, discharging the cooling fluid flow (Cf) may include discharging the cooling fluid flow (Cf) as a discharged fluid flow (E) into another cell 132a. It should be appreciated that, in the case that the discharged fluid (E) is introduced into another cell 132a, the method may be repeated itself, wherein the discharged fluid (E) is now the fluid (H) used for heating the adjacent cell 132b.

[0059] Figure 9 This is a flowchart illustrating a method 300 for forming a heat exchanger 20 having the cooling structure 122 described herein. Method 300 may include, at block 302, a material having a temperature (T) m The material forms at least one cell 132 with a wall 138 having a thickness (t). At frame 304, a flow path is formed extending through at least one cell 132 for fluid flow (i.e., cooling fluid (Cf) and / or heating fluid (H)), wherein the fluid has a fluid temperature (T). f ), and the flow path has a hydraulic diameter (D) HIt can be envisioned that the flow path is a bifurcated flow path 142 as described herein. At box 308, at least one cell is manufactured to have a cell performance factor (UCPF) between 0 and 0.15. The UCPF is represented as:

[0060]

[0061] As will be discussed further in this paper, UCPF considers heat transfer and pressure drop by relating the temperature ratio (the left side of the UCPF equation) to a geometry-based performance factor (the right side of the UCPF equation). A higher temperature ratio means a higher fluid temperature relative to material limitations. A higher temperature ratio means higher performance. In other words, when components in a system or engine can operate at higher temperatures, the overall efficiency of the system, engine, or both increases.

[0062] It has been found that, for any given wall thickness (t), the geometry-based performance factor (GPF) has a hydraulic diameter (D) that falls within the optimal range. H Similarly, for any given hydraulic diameter (D) H The performance factor (GPF) based on geometry has a thickness (t) that falls within the optimal range. In other words, for a given wall thickness (t), there exists a hydraulic diameter (D). H The optimal range for the hydraulic diameter (D) balances the need for maximum heat transfer at minimum pressure drop. H Below this range, the pressure drop becomes excessive. At hydraulic diameters (D...) H Above this range, the ability to optimize heat transfer by packing the maximum number of cells into a given volume decreases.

[0063] It should be understood that the number, size, and configuration of cells are provided by way of example only, and in other exemplary embodiments, cells may have any other suitable configuration.

[0064] As described herein, optimizing the geometry of the cooling structure 122 improves the performance of the heat exchanger 20 within the system and / or engine. This facilitates optimal heat transfer while maintaining a low pressure drop. It has been found that the optimal geometry for each cell 132 lies in the diameter (D) of the opening 140. H And a specific range of wall thicknesses (t) of 138. Finding the optimal balance (if any) previously could only be done through trial and error. This could be a labor- and time-intensive process, as it is iterative and involves selecting different diameters (D). HMultiple cells 132 with a thickness (t) and a total thickness (t). Aircraft and other exemplary systems are designed to operate under a range of conditions, and it is advantageous to have a method for designing heat exchangers with selected cells 132 that avoids redesigning multiple components or systems when requirements at a particular operating point are not met. This optimal geometry defined by UCPF will enable improved cell performance under specific operating conditions. Furthermore, the use of UCPF can aid the heat exchanger design process by determining the optimal range of cell dimensions early in the design process.

[0065] During the aforementioned time-consuming iterative process, the inventors discovered that the thickness (t) of the wall 138 of cell 132 and the diameter (D) of the opening 140 in cell 132 are related. H The relationship between the cell 132 described herein enables a highly compact and efficient heat exchanger due to its ability to accommodate a large heat transfer surface area within a given volume. The bifurcated flow path 142 allows for superior heat transfer performance with very low pressure drop losses compared to known heat exchangers. This relationship, referred to herein as the cell performance factor, or simply “UCPF,” was an unexpected discovery during the heat exchanger design process (i.e., designing heat exchangers for aircraft and other systems and evaluating the impact of cooling structures on heat transfer and pressure drop).

[0066] Fluid temperature (T) f ) and material temperature (T) m The ratio (TR) of ) is expressed as:

[0067]

[0068] The optimal TR is between 5% and 125%, and more narrowly between 5% and 90%. A higher TR corresponds to a more efficient engine component.

[0069] Furthermore, it was found that the geometry of a cell can be represented by a geometry-based performance factor (GPF), expressed as:

[0070]

[0071] Generally, GPF values ​​between 0 and 0.12 are associated with optimal geometry. More specifically, GPF values ​​between 0.01 and 0.12 have been found to provide the desired voltage drop. The optimal GPF value is equal to 0.11.

[0072] UCPF is a combination of TR and GPF factors:

[0073]

[0074] In other words, a UCPF of 0.1375 is equivalent to a high TR value (125%) and an optimal GPF value (0.11).

[0075] Using this relationship, the inventors are able to obtain a heat exchanger with better performance in terms of heat transfer efficiency while having an acceptable pressure drop. The inventors have found that the UCPF of a set of cells can be narrowed to a UCPF range between 0.000245 and 0.15 (0.000245<UCPF<0.15), which defines a cooling structure in an engine component that satisfies both heat transfer requirements and pressure drop requirements. In some embodiments described herein, the UCPF value is greater than or equal to 0.000776 and less than or equal to 0.11 (0.000776≤UCPF≤0.11). Narrowing the UCPF range allows for a deeper understanding of the requirements of a given engine before fully developing specific technology, integration and system requirements. Furthermore, knowing the UCPF range can prevent or minimize late-stage redesign, reduce material costs and save time.

[0076] The UCPF value represents the combined effect of heat transfer and pressure drop. Both high heat transfer and / or low pressure drop will / each will result in a higher UCPF value. Narrowing the UCPF range enables evaluation during the design phase of the trade-off effects of accepting a greater amount of pressure drop in exchange for more heat transfer, and vice versa. The UCPF range relates to the combined effect of heat transfer and pressure drop, so that a designer can understand the trade-offs involved in determining cell dimensions under a specific set of conditions, which enables the designer to produce airfoil members that are better than those previously known.

[0077] Generally, as both the hydraulic diameter and the thickness increase, the GPF also increases. Likewise, as TR increases, UCPF also increases. Increasing the hydraulic diameter (D H ) while keeping the thickness at a minimum minimizes material usage. The reduction in weight and improvement in performance enable the realization of a heat exchanger with excellent performance, which in turn enables a more efficient system and / or engine.

[0078] Taking the TR value into account, it is possible to narrow down the optimal engine performance based on the selected material. For example, a heat exchanger made of a superalloy can operate at temperatures up to 1652°F to 1751°F (900°C to 955°C). Ceramic materials can withstand temperatures up to 2500°F (1371°C). Refractory alloys can reach temperatures close to 3002°F (1650°C). These temperatures are used as the material reference temperature T in Equation 1 m . The fluid temperature T fIt can be within a range of 5% to 100% of the temperature limit for any given material. For example, the TR value of an engine component made of a ceramic material for the hot zone of an engine can be determined, where the material reference temperature T of the ceramic material is located. m 1360℃ (T) m =1360), where the fluid temperature T f Approximately the material reference temperature T m 90% (T) f =1224). Therefore, the TR value is 0.90 or 90%. The higher the TR value, all other things being constant, the higher the UCPF value, which is equivalent to the higher operating limit of the heat exchanger formed by cell 132.

[0079] When the thickness (t) and hydraulic diameter (D) H When both thickness and GPF increase together, the GPF approaches its upper limit of 0.12. However, at approximately t = 5 mm, the GPF begins to decrease with further increases in thickness. The upper limits of both thickness and GPF indicate the maximum weight. Similarly, a higher GPF with lower thickness results in a higher (D) GPF. H This is equivalent to a reduced GPF value. The lower limits of both thickness and GPF indicate the minimum structural integrity. In other words, the closer the GPF is to the upper limit of 0.12, all other things being constant, the higher the UCPF value, which is equivalent to a more compact heat exchanger (a larger heat transfer area per unit volume).

[0080] Therefore, heat exchangers typically become more compact and / or can operate under higher operating limits as the UCPF value reaches its upper limit of 0.15. UCPF balances these two optimal performance factors.

[0081] For example, as shown in Table I below, those with relatively small diameters (D) H A relatively large thickness (t = 5 mm) of cell 132, with a thickness of 0.2 mm, is equivalent to a small GPF (GPF = 0.02), which is undesirable. This combination produces a UCPF value of 0.026. Designers may want to reduce weight while improving efficiency, and this can be achieved by simply reducing the thickness to (t = 0.1 mm), resulting in a UCPF of 0.146, while keeping all other factors constant. Therefore, designers can quickly reduce the required geometry simply by changing one factor, increasing the UCPF to its maximum value of 0.15, while keeping all other variables constant.

[0082] Table 1

[0083]

[0084]

[0085] Turn Figure 10 The graph shows the UCPF along the y-axis and the temperature ratio (TR) along the x-axis. It has been found that the small boundary region 148 and the large boundary region 150 best represent the desired balance described herein, each range depending on the heat exchanger where cell 132 described herein is located.

[0086] The upper boundary line 152 has a slope representing the maximum GPF of 0.12, which defines both the small boundary region 148 and the large boundary region 150. The first lower boundary line 154 has a slope representing the first minimum GPF of 0.017, which defines the small boundary region 148. The second lower boundary line 156 has a slope representing the second minimum GPF of 0.004, which defines the small boundary region 148.

[0087] Both the small boundary region 148 and the large boundary region 150 have a minimum temperature ratio of 5% (TR). min The boundary is defined as 148, where the minimum temperature ratio (TR) is the minimum. min The large boundary region 150 extends between the first maximum temperature ratio (TR1) and 90%. The minimum temperature ratio (TR1) is also within this range. min It extends between 125% and the second maximum temperature ratio (TR2).

[0088] Both the small boundary region 148 and the large boundary region 150 are affected by the minimum cell performance factor (UCPF). min The graph represents the constraints of the two largest cell performance factors: the first largest cell performance factor (UCPF1) for the small boundary region of 148 and the second largest performance area factor (UCPF2) for the large boundary region of 150.

[0089] Turning to Tables II, III, and IV, different thicknesses (0.1, 1, and 2 mm, respectively) and diameters (0.25, 2, and 6 mm, respectively) resulted in minimal changes in the geometry performance factor (GPF). However, combining GPF with temperature ratio (TR) provides a wider range of UCPF values. A smaller TR value (5%) indicates a relatively colder system, while a larger TR value (125%) indicates a relatively hotter region of the system. The resulting UCPF range between 0 and 0.15 provides the optimal variable range for cell 132 described herein, independent of engine location.

[0090] Table II

[0091] Thickness (mm) Diameter (mm) GPF TR(%) UCPF .1 .25 0.116 5 0.0058 1 2 0.118 5 0.0059 2 6 0.114 5 0.0057

[0092] Table III

[0093]

[0094]

[0095] Table IV

[0096] Thickness (mm) Diameter (mm) GPF TR(%) UCPF .1 .25 0.116 125 0.146 1 2 0.118 125 0.148 2 6 0.114 125 0.142

[0097] While a UCPF close to the upper limit of 0.15 is desirable, design constraints (including, but not limited to, manufacturing capability and available envelope volume (V) for heat transfer) can reduce the thickness (t) and diameter (D) of the set of walls 138 associated with cell 132 described herein. H The available range of ) . Using the results described in this paper, Table V below lists the variables (t), (D) discussed in this paper. H The ranges are categorized into small and large ranges for (TR) and (UCPF). Small ranges encompass known prior art thin-wall manufacturing capabilities and low-risk operating temperature ranges relative to the limitations of a given material. Large ranges include a wider range of cell sizes, based on known capabilities and more aggressive operating temperature ranges, which may introduce higher manufacturing risks.

[0098] Table V

[0099]

[0100] Benefits associated with the UCPF described herein include the rapid visualization of tradeoffs in heat transfer and pressure drop, which are constrained by the materials used, the available envelope volume (V) (determined by the configuration of the component or system housing and surrounding components), or any other design constraints. UCPF enables the fabrication of high-performance heat exchangers with peak performance at available factors. While narrowing these multiple factors down to a possible range can save time, money, and resources, the greatest benefit lies at the system level, where a more efficient heat exchanger can improve system performance. Previously developed heat exchangers may peak in one performance domain at design time but lose efficiency or lifetime benefits in another. In other words, UCPF enables the development and production of higher-performance heat exchangers across multiple performance metrics under a given set of constraints.

[0101] This written description uses examples to disclose this disclosure, including best practices, and also enables any person skilled in the art to practice this disclosure, including making and using any apparatus or system and methods of performing any combination. The patentable scope of this disclosure is defined by the claims, but may include other examples that would occur to a person skilled in the art. Such other examples are intended to fall within the scope of the claims if they include structural elements that are not indistinguishable from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

[0102] The following items provide a further aspect: a heat exchanger for a gas turbine engine, the heat exchanger comprising: a cooling structure including at least one cell having a set of walls having a thickness (t), the set of walls defining a fluid-separating conduit having a plurality of openings, each of the plurality of openings having a hydraulic diameter (D). H ), where the average fluid temperature (T) f ) and material temperature limit (T m The ratio of (T) f / T m ) greater than 0 and less than or equal to 1.25 (0 <T f / T m ≤1.25), and wherein the thickness (t) and the hydraulic diameter (D) H ) through equations Interrelated to define the cell performance factor (UCPF), wherein the UCPF is greater than 0 and less than or equal to 0.15 (0 ≤ ... <UCPF≤0.15)。

[0103] The heat exchanger according to any of the foregoing clauses, wherein the cooling structure is disposed within the substrate.

[0104] According to any of the preceding clauses, the heat exchanger wherein the fluid separation conduit defines a branched flow path.

[0105] According to any of the preceding clauses, the heat exchanger wherein the at least one cell is a plurality of cells.

[0106] According to any of the preceding clauses, the heat exchanger wherein the plurality of cells are replicated within an envelope volume to define the cooling structure.

[0107] According to any of the preceding clauses, the heat exchanger wherein the plurality of open fluid-connected cells further define the fluid-separated conduits.

[0108] According to any of the preceding clauses, the heat exchanger wherein the UCPF is greater than 0 and less than or equal to 0.11 (0 <UCPF<0.11)。

[0109] According to any of the preceding clauses, the heat exchanger wherein the thickness (t) is greater than or equal to 0.05 mm and less than or equal to 5 mm (0.05 mm) <t<5mm)。

[0110] According to any of the preceding clauses, the heat exchanger wherein the thickness (t) is greater than or equal to 0.1 mm and less than or equal to 2 mm (0.1 mm) <t<2mm)。

[0111] According to any of the preceding clauses, the heat exchanger, wherein the diameter (D) H ) Greater than or equal to 0.25 mm and less than or equal to 10 mm (0.25 mm) <t<10mm)。

[0112] According to any of the preceding clauses, the heat exchanger, wherein the diameter (D) H ) Greater than or equal to 0.75 mm and less than or equal to 6 mm (0.75 mm) <DH<6mm)。

[0113] According to any of the preceding clauses, the heat exchanger, wherein the T f / T m Greater than or equal to 0.05 and less than or equal to 0.9 (0.05 ≤ T) A / T L ≤0.9).

[0114] A cooling structure for a heat exchanger, the cooling structure comprising: at least one cell having a set of walls having a thickness (t), the set of walls defining a fluid-separating conduit having a plurality of openings, each of the plurality of openings having a hydraulic diameter (D). H ), where the average fluid temperature (T) f ) and material temperature limit (T m The ratio of (T) f / T m ) greater than or equal to 0.05 and less than or equal to 1.25 (0.05 ≤ T) f / T m ≤1.25), wherein the thickness (t) and the hydraulic diameter (D) H ) through equations They are correlated to limit the cell performance factor (UCPF), wherein the UCPF is greater than 0 and less than or equal to 0.15 (0 ≤ UCPF ≤ 0.15).

[0115] According to any of the preceding clauses, the cooling structure wherein the fluid-separating conduit defines a branched flow path.

[0116] According to any of the preceding clauses, the cooling structure wherein the at least one cell is a plurality of cells.

[0117] According to any of the preceding clauses, the cooling structure wherein the plurality of cells are replicated within the envelope volume to define the cooling structure.

[0118] According to any of the preceding clauses, the cooling structure wherein the plurality of openings are fluidly connected to a continuous cell to further define the fluid-separated conduit.

[0119] The cooling structure according to any preceding clause, wherein the UCPF is greater than 0 and less than or equal to 0.11 (0<UCPF≤0.11).

[0120] The cooling structure according to any preceding clause, wherein the thickness (t) is greater than or equal to 0.05mm and less than or equal to 5mm (0.05mm≤t≤5mm).

[0121] The cooling structure according to any preceding clause, wherein the diameter (D H ) is greater than or equal to 0.25mm and less than or equal to 10mm (0.25mm≤t≤10mm).

[0122] A method of forming a heat exchanger, the method comprising: forming at least one cell having a wall, the wall having a thickness (t), the thickness (t) being greater than or equal to 0.05mm and less than or equal to 5mm (0.05mm≤t≤5mm), the at least one cell being formed from a material; forming a flow path extending through the at least one cell, the flow path having a hydraulic diameter (D H ), the hydraulic diameter (D H ) being greater than or equal to 0.25mm and less than or equal to 10mm (0.25mm

Claims

1. A heat exchanger for a gas turbine engine, characterized in that, The heat exchanger includes: A cooling structure comprising at least one cell having a set of walls having a thickness (t), the set of walls defining a fluid-separating conduit having a plurality of openings, each of the plurality of openings having a hydraulic diameter (D). H ), The average fluid temperature (T) f ) and material temperature limit (T m The ratio of () ) greater than 0 and less than or equal to 1.25 (0 < ≤ 1.25), and The thickness (t) and the hydraulic diameter (D) are mentioned. H ) through equation Interrelated to constrain the cell performance factor (UCPF), and The UCPF is greater than 0 and less than or equal to 0.15 (0 < UCPF ≤ 0.15).

2. The heat exchanger according to claim 1, characterized in that, The cooling structure is disposed within the substrate.

3. The heat exchanger according to claim 1, characterized in that, The fluid separation conduit defines a branching flow path.

4. The heat exchanger according to claim 1, characterized in that, The at least one cell mentioned therein can be multiple cells.

5. The heat exchanger according to claim 4, characterized in that, The plurality of cells are replicated within the envelope volume to define the cooling structure.

6. The heat exchanger according to claim 5, characterized in that, The plurality of openings are fluidly connected to consecutive cells to further define the fluid-separating conduit.

7. The heat exchanger according to claim 1, characterized in that, The UCPF is greater than 0 and less than or equal to 0.11 (0 ≤ UCPF ≤ 0.11).

8. The heat exchanger according to claim 1, characterized in that, The thickness (t) is greater than or equal to 0.05 mm and less than or equal to 5 mm (0.05 mm ≤ t ≤ 5 mm).

9. The heat exchanger according to claim 1, characterized in that, The thickness (t) is greater than or equal to 0.1 mm and less than or equal to 2 mm (0.1 mm ≤ t ≤ 2 mm).

10. The heat exchanger according to claim 1, characterized in that, The diameter (D) H ) Greater than or equal to 0.25 mm and less than or equal to 10 mm (0.25 mm ≤ D) H ≤ 10 mm).

11. The heat exchanger according to claim 1, characterized in that, The diameter (D) H ) Greater than or equal to 0.75 mm and less than or equal to 6 mm (0.75 mm ≤ D) H ≤ 6 mm).

12. The heat exchanger according to claim 1, characterized in that, The above Greater than or equal to 0.05 and less than or equal to 0.9 (0.05 ≤ ≤ 0.9).

13. A cooling structure for a heat exchanger, characterized in that, The cooling structure includes: At least one cell having a set of walls having a thickness (t), the set of walls defining a fluid-separating conduit having a plurality of openings, each of the plurality of openings having a hydraulic diameter (D). H ), The average fluid temperature (T) f ) and material temperature limit (T m The ratio of () ) greater than or equal to 0.05 and less than or equal to 1.25 (0.05 ≤ ≤ 1.25), The thickness (t) and the hydraulic diameter (D) are mentioned. H ) through equation Interrelated to constrain the cell performance factor (UCPF), and The UCPF is greater than 0 and less than or equal to 0.15 (0 < UCPF ≤ 0.15).

14. The cooling structure according to claim 13, characterized in that, The fluid separation conduit defines a branching flow path.

15. The cooling structure according to claim 13, characterized in that, The at least one cell mentioned therein can be multiple cells.

16. The cooling structure according to claim 15, characterized in that, The plurality of cells are replicated within the envelope volume to define the cooling structure.

17. The cooling structure according to claim 16, characterized in that, The plurality of openings are fluidly connected to consecutive cells to further define the fluid-separating conduit.

18. The cooling structure according to claim 13, characterized in that, The UCPF is greater than 0 and less than or equal to 0.11 (0 < UCPF ≤ 0.11).

19. The cooling structure according to claim 13, characterized in that, The thickness (t) is greater than or equal to 0.05 mm and less than or equal to 5 mm (0.05 mm ≤ t ≤ 5 mm).

20. The cooling structure according to claim 13, characterized in that, The diameter (D) H ) Greater than or equal to 0.25 mm and less than or equal to 10 mm (0.25 mm ≤ D) H ≤ 10 mm).

21. A method for forming a heat exchanger, characterized in that, The method includes: Form at least one cell having a wall having a thickness (t) greater than or equal to 0.05 mm and less than or equal to 5 mm (0.05 mm ≤ t ≤ 5 mm), the at least one cell being formed of a material; Forming a flow path extending through the at least one cell, the flow path having a hydraulic diameter (D) H The hydraulic diameter (D) H ) greater than or equal to 0.25 mm and less than or equal to 10 mm (0.25 mm ≤ t ≤ 10 mm); and The at least one cell is manufactured, wherein the at least one cell has a cell performance factor (UCPF) greater than or equal to 0.000245 and less than or equal to 0.15 (0.000245 ≤ UCPF ≤ 0.15).

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