Patent Application
20240125564
The present disclosure relates to heat exchangers and methods of design, and, more specifically, to a segmented heat exchanger with variable heat-transfer properties for each segment.
As heat is transferred through a heat exchanger, material of the heat exchanger experiences thermal structural fatigue due to the temperature difference between a hot side and a cold side of the heat exchanger. This temperature difference is largest at a corner of the heat exchanger where hot air and cold air both enter. To prevent structure fatigue, the temperature differences throughout the heat exchanger are kept below the maximum stress limit the material can endure before yielding. However, constraining the temperature difference also limits the maximum total heat that can be transferred through the heat exchanger.
A method is disclosed herein. In various embodiments, the method comprises: dividing a heat exchanger design into a plurality of modules, the plurality of modules arranged in a grid, each module in the plurality of modules including: a first fluid conduit defining an inlet, an outlet, and a heat-transfer surface, and a first flow direction, and a second fluid conduit defining a second inlet, a second outlet, a second heat-transfer surface, and a second flow direction, the second flow direction different from the first flow direction; and determining a heat-transfer augmenter arrangement for the first fluid conduit and the second fluid conduit of each module in the plurality of modules based on a stress threshold of the module in the plurality of modules.
In various embodiments, the method further comprises manufacturing a heat exchanger based on the heat exchanger design.
In various embodiments, the first fluid conduit of each module in the plurality of modules forms a first heat exchanger fluid conduit extending from a first side of the heat exchanger design to a second side of the heat exchanger design, and the second fluid conduit of each module in the plurality of modules form together a second heat exchanger fluid conduit extending from a third side of the heat exchanger design to a fourth side of the heat exchanger design. In various embodiments, in response to determining the heat-transfer augmenter arrangement, the first fluid conduit in a first module of the plurality of modules has a first heat-transfer coefficient and the first fluid conduit in a second module of the plurality of modules has a second heat-transfer coefficient, the second heat-transfer coefficient being different than the first heat-transfer coefficient. In various embodiments, in response to determining the heat-transfer augmenter arrangement, the first fluid conduit in a first module of the plurality of modules includes a first wave and the first fluid conduit in the second module of the plurality of modules has a second wave, the second wave having a different wavelength than the first wave. In various embodiments, the first fluid conduit is disposed vertically adjacent to the second fluid conduit.
In various embodiments, the determining the heat-transfer augmenter arrangement further comprises simulating each module in the plurality of modules as an independent heat exchanger in the heat exchanger design.
In various embodiments, the heat exchanger design is a plate heat exchanger design.
A design process is disclosed herien. In various embodiments, the design process comprises: receiving, via a processor, boundary conditions for designing a modular heat exchanger, the modular heat exchanger comprising an M×N grid of modules, each module including at least two of a first fluid conduit defining a first flow direction interleaved and at least two off a second fluid conduit defining a second flow direction, the at least two of the first fluid conduit interleaved between the at least two of the second fluid conduit, the boundary conditions including a stress threshold envelope; determining, via the processor and through a simulator, a desired heat-transfer coefficient for each heat-transfer surface in each fluid conduit of the modular heat exchanger based on the boundary conditions; and in response to determining the desired heat-transfer coefficient, designing a heat-transfer arrangement for each fluid conduit in each module of the modular heat exchanger.
In various embodiments, the boundary conditions further include an inlet temperature of a first fluid at a first side of the modular heat exchanger and a second inlet temperature of a second fluid at a second side of the modular heat exchanger.
In various embodiments, M×N is at least 3×3.
In various embodiments, the first fluid conduit of each module in the plurality of modules forms a first heat exchanger fluid conduit extending from a first side of the modular heat exchanger to a second side of the modular heat exchanger, and the second fluid conduit of each module in the plurality of modules form together a second heat exchanger fluid conduit extending from a third side of the modular heat exchanger to a fourth side of the modular heat exchanger. In various embodiments, the designing the heat-transfer arrangement includes designing a first wave in the first fluid conduit of a first module and designing a second wave in the first fluid conduit of a second module, the first wave having a different wavelength than the second wave. In various embodiments, the designing the heat-transfer arrangement includes designing a first heat-transfer augmenter in the first fluid conduit of the first module and designing a second heat-transfer augmenter in the first fluid conduit of the second module, wherein the first heat-transfer augmenter is different from the second heat-transfer augmenter.
A modular heat exchanger is disclosed herein. In various embodiments, the modular heat exchanger comprises: a grid of heat exchanger modules, the grid of heat exchanger modules comprising: a first side disposed laterally opposite a second side, a first plurality of fluid conduits, each fluid conduit in the first plurality of fluid conduits extending from the first side to the second side, each fluid conduit in the first plurality of fluid conduits extending through a first set of modules in the grid of heat exchanger modules, a first fluid conduit of a first module in the grid of heat exchanger modules, a second fluid conduit of a second module in the grid of heat exchanger modules, and a third fluid conduit of a third module in the grid of heat exchanger modules defining a respective fluid conduit in the first plurality of fluid conduits, and a first heat-transfer arrangement of a first heat-transfer surface in the first fluid conduit being different from a second heat-transfer arrangement of a second heat-transfer surface of the second fluid conduit.
In various embodiments, a third heat-transfer arrangement of a third heat-transfer surface of the third fluid conduit is different from the first heat-transfer arrangement and the second heat-transfer arrangement.
In various embodiments, the grid of heat exchanger modules further comprises a third side disposed laterally opposite a fourth side, a second plurality of fluid conduits extending from the third side to the fourth side, each fluid conduit in the second plurality of fluid conduits extending through a second set of modules in the grid of heat exchanger modules. In various embodiments, a fourth fluid conduit of a fourth module in the grid of heat exchanger modules, a fifth fluid conduit of a fifth module in the grid of heat exchanger modules, and the first module in the grid of heat exchanger modules defines a sixth fluid conduit in the second plurality of fluid conduits. In various embodiments, a fourth heat-transfer arrangement of a fourth heat-transfer surface in the fourth fluid conduit is different from a fifth heat-transfer arrangement of a fifth heat-transfer surface of the fifth fluid conduit. In various embodiments, a sixth heat-transfer arrangement of a sixth heat-transfer surface of the sixth fluid conduit is different from the fourth heat-transfer arrangement and the fifth heat-transfer arrangement.
The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. A more complete understanding of the present disclosure, however, may best be obtained by referring to the following detailed description and claims in connection with the following drawings. While the drawings illustrate various embodiments employing the principles described herein, the drawings do not limit the scope of the claims.
The following detailed description of various embodiments herein refers to the accompanying drawings, which show various embodiments by way of illustration. While these various embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, it should be understood that other embodiments may be realized and that changes may be made without departing from the scope of the disclosure. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Also, any reference to attached, fixed, connected, or the like may include permanent, removable, temporary, partial, full or any other possible attachment option. Additionally, any reference to without contact (or similar phrases) may also include reduced contact or minimal contact. It should also be understood that unless specifically stated otherwise, references to “a,” “an” or “the” may include one or more than one and that reference to an item in the singular may also include the item in the plural. Further, all ranges may include upper and lower values and all ranges and ratio limits disclosed herein may be combined.
Typical heat exchangers are designed and configured to meet desired heat-transfer and desired pressure drop metrics. After the design is modeled, structural simulations are performed to determine whether structural criteria for the heat exchanger has been met. In response to the simulations, the heat exchanger model often goes through various design iterations and modifications to reduce a stress impact due to thermal loads throughout the heat exchanger during operation. Heat exchangers designed in this manner typically include consistent heat-transfer features throughout the heat exchanger (i.e., one section is designed and configured identical to an adjacent section) within the heat exchanger.
Disclosed herein is a heat exchanger comprising a plurality of heat exchanger modules. The plurality of heat exchanger modules can be arranged in a grid (e.g., a four×four grid, a five by five grid, a six by six grid, etc.). The present disclosure is not limited in this regard. Each module in the plurality of heat exchanger modules can have similar external parameters (i.e., can be approximately a same size and shape externally). However, each module in the plurality of heat exchanger modules can comprise variable internal parameters (i.e., variable heat-transfer augmentors within a fluid conduit disposed therethrough). In this regard, each heat exchanger module can be designed and configured to optimize a total heat-transfer through the heat exchanger module, in accordance with various embodiments, as described further herein.
In typical heat exchanger modeling, heat exchangers are designed and sized based on a total heat-transfer threshold (e.g., a heat-transfer coefficient threshold) and pressure drop threshold (e.g., a change in pressure from an inlet to the heat exchanger to an outlet of the heat exchanger). In typical heat exchanger model, the constraints are often added afterwards, and thermal stress analysis is performed on the design to determine whether the heat exchanger meet deterministic stress criteria (i.e., as a function of material properties of the heat exchanger). The typical heat exchanger model then goes through design iterations with modifications to reduce the stress impact until the heat exchanger meets the deterministic stress criteria. Disclosed herein is a heat exchanger design process that tailors an initial heat exchanger design for heat-transfer and stress reduction to ensure that the heat exchanger design meets a deterministic-criteria for stress and heat-transfer. The design process disclosed herein allows for a more rigorous and tailored design process making the process significantly faster by reducing the number of iterations on the heat exchanger design, in accordance with various embodiments.
Referring to
Multiple sections of the gas turbine engine 100 generate heat during engine operation, including the fan 140, the compressor sections 150, 160, the combustion section 180, the turbine sections 190, 191, and mechanical components such as bearings 115 and gearboxes. The heat may be carried by fluids that are communicated throughout these and other portions of the engine 100. For example, fuel and oil may be circulated throughout the gas turbine engine 100 and carry a portion of the heat generated during engine operation. Various fluids and media may be circulated throughout an engine during operation and may carry engine heat including, without limitation, air, fuel, oil, lubricating fluid, hydraulic fluid, thermally neutral heat-transfer fluid, or any other fluid suitable for circulating in a gas turbine engine 100.
In various embodiments of the present disclosure, the gas turbine engine 100 comprises a thermal management system utilizing one or more heat exchangers designed in accordance with the processes disclosed herein. Various heat exchangers may be incorporated into the thermal management system including, without limitation, air to air heat exchangers, air to fluid heat exchangers, and fluid to fluid heat exchangers. The present disclosure is not limited in this regard.
Referring now to
In various embodiments, the heat exchanger 200 is an air-to-air heat exchanger. In this regard, the heat exchanger 200 is configured to receive a first airflow 201 that travels from a first side 202 laterally (e.g., substantially parallel to Y-axis of an XYZ coordinate system as shown in
In various embodiments, the first airflow 201 comprises a first temperature and the second airflow 205 comprises a second temperature. In various embodiments, the first airflow 201 is a higher temperature than the second airflow 205. In this regard, in accordance with various embodiments, the heat exchanger 200 can be designed and configured to reduce a temperature of the first airflow 201 and/or to increase a temperature of the second airflow. In various embodiments, an inlet temperature of the first airflow 201 can be significantly greater than an inlet temperature of the second airflow. In this regard, the heat exchanger 200 can be susceptible to a significant temperature gradient, resulting in thermal growth differences between colder areas of the heat exchanger relative to hotter areas of the heat exchanger. In this regard, thermal stresses can have a significant impact on a life of a heat exchanger (e.g., due to low cycle fatigue from thermal stresses), in accordance with various embodiments.
In various embodiments, the heat exchanger 200 comprises a plurality of plates 210 (e.g., plates 212, 214, 216, 218, 219). Each plate in the plurality of plates can be spaced apart vertically (e.g., along the Z-axis) from an adjacent plate in the plurality of plates. For example, plate 212 can be spaced apart vertically from plate 214, plate 214 can be spaced apart vertically from plate 216, etc. In various embodiments, the heat exchanger 200 further comprises a plurality of sidewalls 220. In various embodiments, the two plates in the plurality of plates 210 and two sidewalls in the plurality of sidewalls 220 can define a fluid conduit therethrough. For example, plate 212, plate 214, sidewall 222, and sidewall 224 can define a fluid conduit 232 extending therethrough from the first side 202 laterally to the second side 204. In various embodiments, as described further herein, each fluid conduit in the heat exchanger 200 can comprise heat-transfer augmentors (e.g., fins, protrusions, turbulators, corrugations, etc.). The present disclosure is not limited in this regard.
Referring now to
In various embodiments, the method 300 further comprises dividing the heat exchanger design into a plurality of modules (step 304). With reference now to
In various embodiments, each module in the plurality of modules 10 can be configured, and modeled, as an independent heat exchanger. For example, with reference now to
Referring back to
With reference now to
In various embodiments, a heat-transfer augmenter arrangement (e.g., heat-transfer augmenter arrangement 1161, 1151, etc.) can comprise a heat-transfer augmenter (or a plurality of heat-transfer augmenters). In various embodiments, the heat-transfer augmenter arrangement 1161 comprises a fin 410 that defines a wave 412 laterally (e.g., in the X-direction) from a first side 401 to a second side 402). Although illustrated as a sinusoidal wave, the present disclosure is not limited in this regard. For example, the wave 412 can comprise a square wave (
In various embodiments, the wave 412 extends through the conduit from the inlet to the outlet. For example, the wave 412 can extend from the inlet 1611 of the fluid conduit 161 to the outlet 1612 of the fluid conduit 161. In various embodiments, the wave 412 can comprise a uniform cross-sectional shape from the inlet 1611 to the outlet 1612. In this regard, the module 16 can be easier to manufacture. However, the present disclosure is not limited in this regard. For example, the wave 412 can have a variable cross-sectional shape (e.g., having a variable amplitude, a variable wavelength, a variable height, etc.). In various embodiments, the variable cross-sectional shape can vary in a smooth (or continuous manner) (i.e., a wavelength can vary continuously along a length of the wave 412). In various embodiments, the variable cross-sectional shape can vary in a discrete manner (i.e., a first section can have a first wavelength over a first length and can transition to a second section that has a second wavelength where the second wavelength is different from the first wavelength). The present disclosure is not limited in this regard.
In various embodiments, a heat-transfer augmenter arrangement (e.g., heat-transfer augmenter arrangement 1161, 1151, etc.) can comprise a plurality of fins. For example, with reference now to
In various embodiments, as described previously herein, each conduit of each module in the plurality of modules 10 can comprise a heat-transfer augmenter arrangement that is different from an adjacent conduit in the respective module, or an adjacent conduit in an adjacent module. For example, with reference back to
Referring back to
Referring now to
In various embodiments, the processor can determine a threshold stress envelope for the heat exchanger based on the material properties (i.e., the processor can retrieve data from a material property database and determine a threshold stress envelope (e.g., as a function of temperature or the like). In various embodiments, the threshold stress envelope can be provided as an input to the processor, instead of the material properties. The present disclosure is not limited in this regard. In various embodiments, the threshold stress envelope can be based on a yield stress of a material of the heat exchanger, an ultimate tensile stress of the material of the heat exchanger, or the like. The present disclosure is not limited in this regard. In various embodiments, the threshold stress envelope can be based on a margin of safety. In this regard, the threshold stress envelope can factor in potential deficiencies in the material, potential estimation deficiencies from a simulator, or the like.
In various embodiments, the process 700 further comprises determining, via the processor, a desired heat-transfer coefficient for each heat-transfer surface (e.g., a surface of plate 214 within fluid conduit 161 from
In various embodiments, in response to determining the desired heat-transfer coefficient, designing a heat-transfer arrangement of each heat-transfer surface for each fluid conduit of each module in the plurality of modules. In this regard, each conduit of each module can include a different heat-transfer augmenter arrangement, in accordance with various embodiments.
Benefits, other advantages, and solutions to problems have been described herein regarding specific embodiments. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the disclosure. The scope of the disclosure is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” Moreover, where a phrase similar to “at least one of A, B, or C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C. Different cross-hatching is used throughout the figures to denote different parts but not necessarily to denote the same or different materials.
Systems, methods, and apparatus are provided herein. In the detailed description herein, references to “one embodiment,” “an embodiment,” “various embodiments,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments.
Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112(f) unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
Finally, any of the above-described concepts can be used alone or in combination with any or all the other above-described concepts. Although various embodiments have been disclosed and described, one of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. Accordingly, the description is not intended to be exhaustive or to limit the principles described or illustrated herein to any precise form. Many modifications and variations are possible considering the above teaching.
