Modular combustion chamber

Abstract

The application discloses a modular combustion cavity, belongs to the field of power technology, and can solve the problem that the existing combustion cavity with complex shape and extreme size is difficult to be engineered in performance, quality and cost. The combustion cavity is divided into N segmented cavities in the axial direction, and each segmented cavity is divided into M segmented cavity walls in the circumferential direction; wherein N is greater than or equal to 1, and M is greater than or equal to 2; adjacent segmented cavities are sealingly connected through a first connecting structure; and adjacent segmented cavity walls are sealingly connected through a second connecting structure. The application is used for manufacturing the combustion cavity.

Description

Technical Field

[0001] This invention relates to a modular combustion chamber, belonging to the field of power technology. Background Technology

[0002] Combustion chambers are used in detonation engines, aero-engines, space engines, and heavy-duty gas turbines, serving as crucial components for converting chemical energy into thermal and kinetic energy. Aero-engine combustion chambers can withstand prolonged high-temperature combustion without damage, requiring high-temperature resistant materials, thermal barrier coatings, and film cooling structures, resulting in complex structures and high costs. Space engine combustion chambers typically do not utilize film cooling and are generally single-use. As an emerging type of engine, detonation engines have the potential for higher combustion efficiency compared to conventional aero-engines, but their relatively elongated combustion chambers present significant challenges in thermal control. Currently, to ensure the stability of the detonation wave, the combustion chamber has been greatly simplified compared to aero-engine combustion chambers, generally featuring a circumferentially integrated rotating body. The difficulty in effectively protecting the elongated chamber with film cooling makes it challenging for detonation engines to operate at high temperatures for extended periods (greater than one hour), hindering the practical application of this new type of engine.

[0003] For elongated or more complex combustion chambers, achieving optimal combustion efficiency is necessary. However, manufacturing them using thin-shell structures similar to those in aero engines is difficult, resulting in significant material waste and challenges in applying thermal protection structures. This makes it impossible to manufacture many combustion chambers or difficult to implement film protection. Furthermore, for some ultra-long and ultra-large combustion chambers, such as those exceeding twice the size of current commercial aero-engine combustion chambers, manufacturing costs increase dramatically with size and complexity, limiting the implementation of design solutions. For small and ultra-small combustion chambers, the enclosed structure makes applying active film protection difficult; without it, the long-term stability of the combustion chamber is hard to guarantee. Summary of the Invention

[0004] This invention provides a modular combustion chamber that can solve the problem that existing combustion chambers with complex shapes and extreme sizes are difficult to engineer in terms of performance, quality and cost.

[0005] This invention provides a modular combustion chamber, which is divided into N segmented chambers along the axial direction, and each segmented chamber is divided into M block-shaped chamber walls along the circumferential direction; wherein, N≥1, M≥2;

[0006] The adjacent segmented cavities are sealed together by a first connecting structure;

[0007] The adjacent segmented cavity walls are sealed together by a second connecting structure.

[0008] Optionally, air film pores are provided on the wall of the segmented cavity;

[0009] The air film pore includes a groove portion disposed on the outer wall of the segmented cavity wall and an inclined hole portion disposed on the inner wall of the segmented cavity wall; the top end of the inclined hole portion communicates with the bottom end of the groove portion.

[0010] Optionally, air film pores are provided on the wall of the segmented cavity;

[0011] The elevation angle of the hole axis of the air film hole relative to the inner wall sectional surface of the segmented cavity wall is 12° to 90°.

[0012] The projection of the bore axis of the gas film pore onto the inner wall section of the segmented cavity wall has an axial deviation angle of 0° to 180° relative to the combustion cavity.

[0013] Optionally, the segmented cavity wall is provided with air film holes; the air film holes are straight holes or inclined holes.

[0014] Optionally, after all the segmented cavity walls are assembled, the air film pores on them are distributed in an array or extended in a spiral shape along the axial direction of the combustion cavity.

[0015] Optionally, the cross-section of the combustion chamber is circular, elliptical, multi-lobed, or an irregular closed shape.

[0016] Optionally, the combustion chamber has a multi-lobed cross-section, and the multi-lobed cross-section extends spirally along the axial direction of the combustion chamber to form the inner wall of the combustion chamber.

[0017] Optionally, each of the segmented cavities is provided with the first connecting structure on the non-combustion side, and adjacent segmented cavities are sealed together through the first connecting structure;

[0018] Each of the segmented cavity walls is provided with a second connecting structure on its non-combustion side, and adjacent segmented cavity walls are sealed together through the second connecting structure.

[0019] Optionally, the first connection structure of adjacent segmented cavities adopts an interlocking structure;

[0020] And / or,

[0021] The second connection structure of the adjacent segmented cavity walls adopts an interlocking structure.

[0022] Optionally, the first connecting structure and / or the second connecting structure is an outer edge structure located at the end of the segmented cavity wall, and the outer edge structure is connected by fastening bolts or welding.

[0023] The beneficial effects that this invention can produce include:

[0024] (1) The modular combustion chamber provided by the present invention can transform the slender combustion structure into modules that can be processed both internally and externally due to modular decomposition. This enables low-cost and high-quality manufacturing of complex chambers and narrow, extreme chambers. At the same time, it can easily apply active thermal protection functions, which is of great help to the performance breakthrough of power systems such as detonation engines and aerospace engines.

[0025] (2) The modular combustion chamber provided by the present invention can easily implement spiral gas film protection, and the angle variation range of the gas film protection structure can be far greater than that of the overall closed combustion chamber.

[0026] (3) The modular combustion chamber provided by the present invention can be appropriately decomposed to realize a combustion chamber with a non-circular circumferential cross section and a variable diameter axial cross section, and conveniently realize complex combustion inner walls such as spirals.

[0027] (4) The modular combustion chamber provided by the present invention can be used to realize combustion chambers of extreme sizes, including ultra-large diameter, ultra-small diameter, and ultra-long axial dimension, due to the appropriate modular decomposition. At the same time, since the manufacturing task is decomposed from large closed parts into significantly reduced open processing shapes, the quality of the blank can be better guaranteed and the processing cost can be significantly reduced. Attached Figure Description

[0028] Figure 1 This is an exploded view of the modular combustion chamber structure provided in an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the segmented cavity wall structure provided in an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the segmented cavity wall connection structure provided in an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the composite tilt angle air film pore structure provided in an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the spiral distribution of air film pores provided in an embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of the irregularly shaped combustion chamber structure provided in an embodiment of the present invention;

[0034] Figure 7 These are schematic diagrams of four cross-sectional structures of combustion chambers provided in embodiments of the present invention;

[0035] Figure 8 This is a schematic diagram of a modular, slender combustion chamber structure provided in an embodiment of the present invention;

[0036] Figure 9 A schematic diagram of a modular irregular cross-section combustion chamber structure provided in an embodiment of the present invention;

[0037] Figure 10 This is a schematic diagram of a modular variable diameter combustion chamber structure provided in an embodiment of the present invention.

[0038] List of components and reference numerals:

[0039] 10. Combustion chamber; 11. Segmented chamber; 12. Segmented chamber wall; 13. Gas film hole; 14. Groove section; 15. Inclined hole section; 16. Fastening bolt; 17. Outer edge structure. Detailed Implementation

[0040] The present invention will now be described in detail with reference to the embodiments, but the present invention is not limited to these embodiments.

[0041] This invention provides a modular combustion chamber 10, which is divided into N segmented chambers 11 along the axial direction, and each segmented chamber 11 is divided into M segmented chamber walls 12 along the circumferential direction; wherein, N≥1, M≥2; adjacent segmented chambers 11 are sealed together by a first connecting structure; and adjacent segmented chamber walls 12 are sealed together by a second connecting structure.

[0042] like Figure 1 As shown, the combustion chamber 10 is divided into modular components suitable for manufacturing along the circumferential and axial directions. These modules are connected to each other, taking into account both strength and sealing requirements. Through the combination of modules, all functions of the combustion chamber 10 are realized, especially the active cooling function, the thermal barrier coating function, the axial and circumferential expansion function, and the fuel and oxygen supply function.

[0043] Furthermore, each segmented cavity 11 has a first connecting structure on its non-combustion side, and adjacent segmented cavities 11 are sealed together by the first connecting structure; each segmented cavity wall 12 has a second connecting structure on its non-combustion side, and adjacent segmented cavity walls 12 are sealed together by the second connecting structure. In practical applications, the first connecting structure and / or the second connecting structure can be an outer edge structure 17 located at the end of the segmented cavity wall 12, and the outer edge structure 17 is connected or welded by fastening bolts 16.

[0044] For details, please refer to Figure 1 As shown, the combustion chamber 10 is divided into N segments along its axial direction, N1-NS, where N≥1. Each axial segment is further divided into M parts along its circumference, where M≥2, preferably M≥4.

[0045] like Figure 2As shown, one of the segmented cavity walls 12, according to functional requirements, has the function of convenient connection with other modules on the non-combustion side, including but not limited to mechanical connection. For example, in practical applications, fastening bolts 16 or welding can be used for connection. After the above-mentioned segmented cavity walls 12 are connected, they meet the requirements of combustion, strength, and sealing. The segmented cavity walls 12 are manufactured discretely, and functional structural processing such as coating, gas film hole 13 processing, reinforcement, and combustion medium introduction are completed. Then they are assembled to form a complete combustion chamber component.

[0046] The connection between the segmented cavity walls 12 needs to simultaneously meet the requirements of strength, thermal protection, and sealing. Therefore, the joint between the segmented cavity walls 12 preferably adopts an interlocking structure, such as... Figure 3 As shown, once the assembly is complete, the requirements for sealing and combustion heat protection can be fully guaranteed.

[0047] refer to Figure 4 As shown, in this embodiment of the invention, the segmented cavity wall 12 is provided with an air film hole 13; the air film hole 13 includes a groove portion 14 provided on the outer wall of the segmented cavity wall 12 and an inclined hole portion 15 provided on the inner wall of the segmented cavity wall 12; the top end of the inclined hole portion 15 is connected to the bottom end of the groove portion 14.

[0048] To ensure the strength of the combustion chamber 10 and to apply gas film protection structures in various directions, the combustion chamber 10 of the present invention can use a thin-walled structure, but a structure with sufficient thickness is preferred. When the thickness is large, the machining of the inclined gas film protection structure becomes difficult. Therefore, the present invention uses a method of machining a sufficiently thick connecting blind hole (i.e., the groove portion 14) and then adding a gas film protection structure (i.e., the oblique hole portion 15). A segmented module is used, and the degree of segmentation depends on the requirements for applying the coating and machining the gas film holes 13. For example, dividing the circular cavity into four sections along the circumference allows for the drilling of inclined holes along the circumference, while a relatively long and narrow closed cavity can be machined along the axial direction, making it easier to machine the gas film holes 13 at all angles. The annulus can be divided into a uniform number of sections. Due to structural interference, if some large-angle holes still cannot be machined, the number of sections can be further increased if necessary.

[0049] The aforementioned technological breakthroughs have enabled the easy fabrication and realization of large-scale inclined air-film protective structures distributed along a spiral line, such as... Figure 5As shown. For example, the circumference is divided into four sections, and the elevation angle of the hole axis of the air film hole 13 on each section cavity wall 12 relative to the inner wall sectional surface of the section cavity wall 12 is 12° to 90°; the projection of the hole axis of the air film hole 13 onto the inner wall sectional surface of the section cavity wall 12 has an axial deviation angle of 0° to ±180° relative to the combustion chamber 10, forming a composite tilted air film cooling structure. Such a composite tilted air film cooling structure forms an array, which can promote the formation of a spiral continuous air film, and can have better air film adhesion compared to the conventional air film protection structure with only axial tilt.

[0050] It should be noted that, in this embodiment of the invention, the air film holes 13 on the segmented cavity wall 12 can also be straight holes or inclined holes; when all the segmented cavity walls 12 are assembled, the air film holes 13 on them can be distributed in an array, or they can be distributed in a spiral shape along the axial direction of the combustion chamber 10. Those skilled in the art can make settings according to actual conditions, and this embodiment of the invention does not limit them.

[0051] like Figure 7 As shown, the circumferential shape of the combustion chamber 10 can be a circular rotating body, or an ellipse, a multi-lobed shape, or other irregular closed shape, with the goal of achieving optimal combustion, and is not limited to a smooth circular rotating body.

[0052] Furthermore, the combustion chamber 10 has a multi-lobed cross-section, and the multi-lobed cross-section extends spirally along the axial direction of the combustion chamber 10 to form the inner wall of the combustion chamber 10.

[0053] refer to Figure 6 As shown, the shape of the combustion chamber 10 along the axial direction can be of equal size or unequal size, such as tapered reduced size, size with intermediate platform, size with multiple intermediate structures, etc.

[0054] Another embodiment of the present invention provides a modular, elongated combustion chamber 10, such as... Figure 8 As shown, the combustion chamber 10 has a uniform cylindrical inner wall with a diameter of 50 mm and a length of 1000 mm, and is used in detonation engines. Without film cooling, relying solely on external water cooling, it is difficult to ensure the surface integrity of the inner wall of this combustion chamber 10 for extended periods when exposed to temperatures of 1500–3000 K. However, applying suitable film cooling to such a slender combustion chamber 10, as is done in current aero-engine combustion chambers, is extremely difficult. While additive manufacturing can approximate the fabrication of related components, subsequent finishing is extremely challenging.

[0055] In this embodiment, the combustion chamber 10 is decomposed into segmented chambers 11, divided into four circumferentially segmented chamber walls 12, and axially divided into five parts, each segment measuring 200 mm. The first part serves as both ignition and detonation initiation, while subsequent parts constitute the length required for detonation wave propagation. The structure of each segmented chamber wall 12 is similar to... Figure 2 Similarly, it can be quickly connected to other adjacent segmented cavity walls 12 via fastening bolts 16. The gas required for the gas film is supplied from the cavities on the non-combustion side of each module.

[0056] The air film pore 13 preferably uses a complex irregular pore, with the pore axis at an elevation angle of 30° relative to the inner wall sectional surface, and the pore axis projected onto the inner wall sectional surface at a relative axial deviation angle of 60°. The circumferential spacing between the pores is approximately 10 mm, and the axial spacing is arranged in a spiral pattern to form a spiral air film coating.

[0057] Furthermore, the extension section can be lengthened or shortened as needed. For example, using 5 more sections can result in a 2-meter-long combustion chamber 10, while using 2 fewer sections results in a 600-millimeter-long combustion chamber 10.

[0058] Another embodiment of the present invention provides a modular irregular cross-section combustion chamber 10, see reference. Figure 9 As shown, a moderately non-circular cross-section is beneficial for achieving better combustion efficiency. For example, by adding a certain frequency of cross-sectional fluctuations to a circular cross-section, such as... Figure 9 The diagram shows a slightly off-circular four-lobed cross-section, with the lobes extending spirally along the axial direction, resembling the rifling of a gun, designed to help form a stable spiral distribution of combustion energy, such as a standing wave distribution. Along the axial direction, the combustion chamber 10 has a diameter contraction in the middle section, then expands into a conical shape. The maximum inner diameter of the first section is 500 mm, the minimum inner diameter of the contraction section is 200 mm, the overall length is 1200 mm, and the deviation of the four-lobed cross-section from the circular trajectory is 5 mm. This type of structure helps improve the efficiency of the combustion medium in converting thermal energy into kinetic energy. Manufacturing this type of structure with a complete shell is extremely difficult to achieve high quality; adding a film gas protection structure to ensure stable operation over a long period is even more challenging.

[0059] Another embodiment of the present invention provides a modular variable diameter combustion chamber 10, such as... Figure 10 As shown, the combustion chamber 10 is divided into 8 equal parts along the circumference and, according to dimensional variations along the axial direction, into 7 sections of varying lengths, as shown in the figure. The individual chamber walls 12, after being decomposed, become units that can be precisely assembled together, similar to... Figure 2 The structure shown is modified, but the size and shape are adjusted appropriately according to the requirements of the current segmented cavity wall 12. Each segmented cavity wall 12 is machined with air film holes 13 at a 20° angle along the axial direction, with a circumferential spacing of 10 mm and an axial spacing of 20 mm.

[0060] Since each segment wall 12 of the combustion chamber 10 is a double-sided open structure, taking into account the chord height of the arc segment and the wall thickness of the non-combustion surface, the starting dimensions required for processing each module are within the common processing range of conventional machining centers (in this example, approximately circumferential length <260 mm and axial length approximately 200 mm). The significant reduction in the size of the blank material can greatly improve the uniformity of the material, laying the foundation for improving the overall system quality.

[0061] Because of the appropriate modular decomposition, this invention can be used to realize combustion chambers 10 of extreme dimensions, including ultra-large diameter, ultra-small diameter, and ultra-long axial dimensions. At the same time, because the manufacturing task is decomposed from large closed parts into significantly reduced open processing shapes, the quality of the blanks can be better guaranteed and the processing cost can be significantly reduced.

[0062] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A modular combustion chamber, characterized in that, The combustion chamber is used in a detonation engine. The combustion chamber is divided into N segmented chambers along the axial direction. Each segmented chamber is divided into M block cavity walls along the circumferential direction, where N≥3 and M≥4. Adjacent segmented chambers are sealed together by a first connecting structure, and adjacent block cavity walls are sealed together by a second connecting structure. The combustion chamber has a multi-lobed cross-section, which extends spirally along the axial direction to form the inner wall of the combustion chamber. The combustion chamber has a diameter contraction in the middle part along the axial direction. The shape of the combustion chamber along the axial direction is not equal in size, with an equal diameter structure at the front, a diameter contraction structure in the middle, and a conical enlargement structure at the rear. Gas film pores are provided on the block cavity walls. After all the block cavity walls are assembled, the gas film pores on them are distributed in an array or spirally extended along the axial direction of the combustion chamber.

2. The modular combustion chamber according to claim 1, characterized in that, The air film pore includes a groove portion disposed on the outer wall of the segmented cavity wall and an inclined hole portion disposed on the inner wall of the segmented cavity wall; the top end of the inclined hole portion communicates with the bottom end of the groove portion.

3. The modular combustion chamber according to claim 1, characterized in that, The elevation angle of the hole axis of the air film hole relative to the inner wall section of the segmented cavity wall is 12° to 90°; the projection of the hole axis of the air film hole onto the inner wall section of the segmented cavity wall is 0° to 180° relative to the axial angle of the combustion chamber.

4. The modular combustion chamber according to claim 1, characterized in that, The air film pores are straight or inclined.

5. The modular combustion chamber according to claim 1, characterized in that, Each of the segmented cavities is provided with the first connecting structure on its non-combustion side, and adjacent segmented cavities are sealed together through the first connecting structure; each of the segmented cavity walls is provided with the second connecting structure on its non-combustion side, and adjacent segmented cavity walls are sealed together through the second connecting structure.

6. The modular combustion chamber according to claim 5, characterized in that, The first connecting structure of adjacent segmented cavities adopts an interlocking structure; and / or, the second connecting structure of adjacent segmented cavity walls adopts an interlocking structure.

7. The modular combustion chamber according to claim 5 or 6, characterized in that, The first connecting structure and / or the second connecting structure are outer edge structures located at the ends of the segmented cavity walls, and the outer edge structures are connected by fastening bolts or welding.

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