Blending hopper, combustion chamber and aircraft engine

Abstract

The application discloses a mixing hopper which is arranged on the wall of a flame tube, and comprises an inner cone part, an outer ring part arranged outside the inner cone part, and a hopper cap used for connecting the wall of the flame tube. The inner cone part and the hopper cap enclose a mixing cavity used for mixing high-temperature gas and cooling gas flow. The inner cone part and the outer ring part enclose a cooling gap used for the flow of the cooling gas flow. Cooling holes are arranged on the inner cone part and are respectively communicated with the mixing cavity and the cooling gap, and are used for introducing the cooling gas flow into the cooling gap to impact cool the outer ring part and form a cooling gas film on the inner cone part. The outer ring part actively uses a small amount of cooling gas flow in cooperation with the cooling holes to effectively reduce the wall temperature of the mixing hopper and prevent the mixing hopper from ablation. Meanwhile, the outer ring part can also shield part of the wall of the inner cone part to prevent the inner cone part from ablation as much as possible, and the cooling effect is good, the service life of the mixing hopper is prolonged, and the mixing hopper can be used in the flame tube for a long time. In addition, the application further discloses a combustion chamber. In addition, the application further discloses an aero-engine.

Description

Mixing bucket, combustion chamber and aero engine Technical Field

[0001] This invention relates to the field of aero-engine technology, and in particular, to a mixing bucket. Furthermore, this invention also relates to a combustion chamber including the aforementioned mixing bucket. Additionally, this invention relates to an aero-engine including the aforementioned combustion chamber. Background Technology

[0002] With the advancement of aero-engine technology, high-performance aero-engine combustors typically require characteristics such as high temperature rise and compact design. High temperature rise refers to a combustor inlet temperature exceeding 800K and a temperature rise exceeding 1100K, significantly increasing the heat load on the combustor and making cooling difficult. Compact design refers to a small combustor size and volume, resulting in a short gas residence time and difficulty in achieving high-quality outlet temperatures. Therefore, to improve the combustor outlet temperature field, mixing hoppers are usually installed inside the combustor to effectively increase the mixing depth, thereby improving the mixing efficiency of cold gas with high-temperature combustion gas. However, existing mixing hoppers are prone to erosion within the high-temperature-rise combustor, resulting in a short service life.

[0003] For example, Chinese invention patent application CN111780165A proposes a flame tube, a recirculation combustion chamber, and an aero-engine. It uses a mixing bucket with a tangential angle within the flame tube, the bucket being a sloping bucket with a shorter side on the windward side and a longer side on the leeward side, to reduce the scouring effect of high-temperature combustion gases. However, due to the lack of an active cooling structure, it cannot actively reduce the impact of the high-temperature combustion gases, and prolonged operation still leads to the ablation of the mixing bucket. Another Chinese invention patent application CN114791109A proposes a ceramic matrix composite flame tube with an air intake bucket. The air intake bucket is installed using a floating structure, creating a circumferential gap between the wall of the air intake bucket and the flame tube wall for cooling. However, this cooling method results in a complex structure, low reliability, low cooling efficiency, and a large required cooling air volume, making it unsuitable for high-temperature combustion chambers. Summary of the Invention

[0004] This invention provides a mixing bucket, a combustion chamber, and an aero-engine to solve the technical problems of poor cooling effect, low reliability, and easy ablation in high-temperature combustion chambers of existing mixing buckets.

[0005] According to one aspect of the present invention, a mixing bucket is provided for being disposed on the wall of a flame tube. The mixing bucket includes an inner cone portion, an outer ring portion surrounding the inner cone portion, and a bucket cap for connecting to the wall of the flame tube. The inner cone portion and the bucket cap enclose a mixing cavity for mixing high-temperature combustion gas and cooling gas flow. The inner cone portion and the outer ring portion enclose a cooling gap for the flow of cooling gas flow. Cooling holes are provided on the inner cone portion, which are respectively connected to the mixing cavity and the cooling gap, for introducing cooling gas flow into the cooling gap to impact and cool the outer ring portion and form a cooling gas film on the inner cone portion.

[0006] As a further improvement to the above technical solution:

[0007] Furthermore, the axial length of the inner cone is greater than the axial length of the outer ring.

[0008] Furthermore, the axial length of the outer ring portion extending into the flame tube relative to the flame tube wall is K, where K is 1.0mm-2.0mm.

[0009] Furthermore, the difference between the axial length of the inner cone portion extending into the flame tube relative to the flame tube wall and the axial length of the outer ring portion extending into the flame tube relative to the flame tube wall is D, where D is 1.0mm-2.0mm.

[0010] Furthermore, the included angle between the end face of the bucket cap away from the flame tube wall and the axis of the cooling hole is β, where β is 50°-75°.

[0011] Furthermore, the inner cone angle of the inner cone is α, where α is 5°-13°.

[0012] Furthermore, the distance between the impact cooling point of the cooling airflow on the inner wall of the outer ring and the cooling gap outlet is H, where H is 1.0mm-1.5mm.

[0013] Furthermore, the outlet width of the cooling gap is B, which is 0.3mm-0.7mm.

[0014] According to another aspect of the invention, a combustion chamber is also provided, which includes the mixing hopper described above.

[0015] According to another aspect of the invention, an aircraft engine is also provided, which includes the combustion chamber described above.

[0016] The present invention has the following beneficial effects:

[0017] The mixing hopper of this invention is connected to the flame tube wall via a hopper cap for mounting on the flame tube wall. The inner cone and hopper cap enclose a mixing chamber for mixing high-temperature combustion gas and cooling gas flow. Most of the cooling gas flow entering the mixing chamber rapidly mixes with the high-temperature combustion gas to form a mixing jet, which is then introduced into the flame tube to improve the mixing efficiency of the cooling gas flow with the high-temperature combustion gas. A small portion of the cooling gas flow enters the cooling gap between the inner cone and the outer ring through cooling holes on the inner cone, impacting and cooling the outer ring and forming a cooling gas film on the inner cone. This reduces the wall temperature of the mixing hopper, thereby preventing mixing. To prevent mixing bucket erosion, this solution addresses this issue by creating cooling holes in the inner cone and then guiding the cold airflow through the outer ring. This allows the mixing process to be achieved in the inner cone while the outer ring, in conjunction with the cooling holes, actively uses a small amount of cooling airflow to effectively reduce the wall temperature of the mixing bucket, preventing erosion. Simultaneously, the outer ring can shield part of the inner cone wall to further prevent erosion. This superior cooling effect extends the service life of the mixing bucket, enabling it to be used for extended periods within the flame tube. Compared to existing technologies, this solution is suitable for high-temperature combustion chambers, highly practical, and suitable for widespread promotion and application.

[0018] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0020] Figure 1 is a cross-sectional schematic diagram of the mixing hopper according to a preferred embodiment of the present invention;

[0021] Figure 2 is a perspective view of the mixing hopper of a preferred embodiment of the present invention;

[0022] Figure 3 is a cross-sectional schematic diagram of the mixing hopper according to a preferred embodiment of the present invention.

[0023] Legend:

[0024] 100, Inner cone section; 200, Outer ring section; 300, Bucket cap; 400, Cooling hole. Detailed Implementation

[0025] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0026] Figure 1 is a cross-sectional schematic diagram of the mixing hopper of a preferred embodiment of the present invention; Figure 2 is a perspective schematic diagram of the mixing hopper of a preferred embodiment of the present invention; Figure 3 is a cross-sectional schematic diagram of the mixing hopper of a preferred embodiment of the present invention.

[0027] As shown in Figures 1-3, the mixing bucket of this embodiment is used to be arranged on the wall of the flame tube. The mixing bucket includes an inner cone portion 100, an outer ring portion 200 surrounding the inner cone portion 100, and a bucket cap 300 for connecting to the wall of the flame tube. The inner cone portion 100 and the bucket cap 300 enclose a mixing cavity for mixing high-temperature combustion gas and cooling airflow. The inner cone portion 100 and the outer ring portion 200 enclose a cooling gap for cooling airflow. The inner cone portion 100 is provided with cooling holes 400 that are respectively connected to the mixing cavity and the cooling gap, for introducing cooling airflow into the cooling gap to impact and cool the outer ring portion 200 and form a cooling air film on the inner cone portion 100. Specifically, the mixing hopper of the present invention is connected to the flame tube wall via a hopper cap 300 for mounting on the flame tube wall. The inner cone portion 100 and the hopper cap 300 enclose a mixing chamber for mixing high-temperature combustion gas and cooling airflow. Most of the cooling airflow entering the mixing chamber rapidly mixes with the high-temperature combustion gas to form a mixing jet, which is then introduced into the flame tube to improve the mixing efficiency of the cooling airflow with the high-temperature combustion gas. A small portion of the cooling airflow enters the cooling gap between the inner cone portion 100 and the outer ring portion 200 through cooling holes 400 on the inner cone portion 100, thereby impact-cooling the outer ring portion 200 and forming a cooling gas film on the inner cone portion 100, thus reducing the wall temperature of the mixing hopper and preventing... To prevent ablation of the mixing bucket, this solution involves creating cooling holes 400 on the inner cone 100 and then guiding the airflow through the outer ring 200. While the inner cone 100 achieves mixing, the outer ring 200, in conjunction with the cooling holes 400, actively uses a small amount of cooling airflow to effectively reduce the wall temperature of the mixing bucket, preventing ablation. Simultaneously, the outer ring 200 also shields part of the inner cone 100 wall to minimize ablation. This effective cooling extends the service life of the mixing bucket, allowing it to be used long-term within the flame tube. Compared to existing technologies, this solution is suitable for high-temperature combustion chambers, highly practical, and suitable for widespread application. Optionally, the thickness of the flame tube wall is C, where C is 1.0mm-2.0mm. Optionally, the thickness of the bucket cap 300 is A, where A is 1.0mm-2.0mm, providing appropriate structural strength and high reliability after connection to the flame tube wall.

[0028] As shown in Figures 1-3, in this embodiment, the axial length of the inner cone portion 100 is greater than the axial length of the outer ring portion 200. Specifically, the outer ring portion 200 protects the inner cone portion 100, while the shorter axial length of the outer ring portion 200 prevents it from extending too far into the flame tube, thus preventing erosion of the outer ring portion 200. The longer axial length of the inner cone portion 100 can hold the mixing jet, improving the mixing efficiency. It should be understood that by designing the inner cone portion 100 and the outer ring portion 200 to be of different lengths, the mixing effect and the self-cooling effect of the mixing bucket are separated, thereby enhancing both the mixing effect and the self-cooling effect.

[0029] As shown in Figures 1-3, in this embodiment, the axial length of the outer ring portion 200 extending into the flame tube relative to the flame tube wall is K, where K is 1.0mm-2.0mm. Specifically, when K is between 1.0mm and 2.0mm, the outer ring portion 200 provides cooling protection without excessively extending into the flame tube, resulting in low pressure from the cooling airflow impact. When K is less than 1.0mm, the outer ring portion 200 cannot provide cooling protection for the inner cone portion 100. When K is greater than 2.0mm, the outer ring portion 200 excessively extends into the flame tube, resulting in high pressure from the cooling airflow impact and making the outer ring portion 200 prone to ablation.

[0030] As shown in Figures 1-3, in this embodiment, the difference between the axial length of the inner conical portion 100 extending into the flame tube relative to the flame tube wall and the axial length of the outer ring portion 200 extending into the flame tube relative to the flame tube wall is D, where D is 1.0mm-2.0mm. Specifically, when D is between 1.0mm and 2.0mm, the axial length of the inner conical portion 100 is appropriate, resulting in good mixing and low pressure for gas film cooling; when D is less than 1.0mm, the axial length of the inner conical portion 100 is relatively small, leading to poor mixing; when D is greater than 2.0mm, the axial length of the inner conical portion 100 not protected by the outer ring portion 200 extending into the flame tube is relatively long, making the inner conical portion 100 prone to ablation.

[0031] As shown in Figures 1-3, in this embodiment, the angle between the end face of the cap 300 away from the flame tube wall and the axis of the cooling hole 400 is β, where β is 50°-75°. Specifically, when β is between 50° and 75°, the cooling airflow has a good impact cooling effect on the outer ring 200, and the flow coefficient of the cooling hole 400 is appropriate, resulting in high cooling efficiency. When β is less than 50°, the cooling airflow has a poor impact cooling effect on the outer ring 200. When β is greater than 75°, the flow coefficient of the cooling hole 400 is low, the flow rate of cooling air entering the cooling gap through the cooling hole 400 is small, and the cooling efficiency is low.

[0032] As shown in Figures 1-3, in this embodiment, the inner cone angle of the inner cone portion 100 is α, which is 5°-13°. Specifically, when α is between 5° and 13°, the mixing effect of the inner cone portion 100 is good, and the cooling effect of the cooling airflow on the inner cone portion 100 is good; when α is less than 5°, because the opening diameter of the inner cone portion 100 is fixed, the axial length of the inner cone portion 100 is too small, resulting in a poor mixing effect; when α is greater than 13°, the cooling gap between the inner cone portion 100 and the outer ring portion 200 is too large, resulting in the cooling airflow being unable to form an air film cooling on the outer wall of the inner cone portion 100, resulting in a poor cooling effect.

[0033] As shown in Figures 1-3, in this embodiment, the distance between the impact cooling point of the cooling airflow on the inner wall of the outer ring 200 and the cooling gap outlet is H, where H is 1.0mm-1.5mm. Specifically, when H is between 1.0mm and 1.5mm, the cooling airflow can form a film cooling on the inner cone 100 while simultaneously impacting and cooling the outer ring 200; when H is less than 1.0mm, the cooling airflow cannot form a film cooling on the inner cone 100; when H is greater than 1.5mm, the aperture and angle of the cooling hole 400 are limited, resulting in a low flow coefficient and low cooling efficiency.

[0034] As shown in Figures 1-3, in this embodiment, the outlet width of the cooling gap is B, which is 0.3mm-0.7mm. Specifically, when B is between 0.3mm and 0.7mm, the mixing bucket is easy to manufacture and the air film cooling effect is good; when B is less than 0.3mm, the mixing bucket is difficult to manufacture; when B is greater than 0.7mm, the cooling airflow may not be able to form an air film on the outer wall of the inner cone 100, resulting in poor cooling effect. Optionally, the corner between the inner cone 100 and the bucket cap 300 is chamfered to improve the flow coefficient of the inner cone 100. Optionally, the chamfer radius at the corner between the inner cone 100 and the bucket cap 300 is R1, which is 0.5mm-1.0mm. Optionally, the distance between the openings of the mixing chamber and the flame tube is φ.

[0035] The combustion chamber of this embodiment includes the mixing hopper described above. Specifically, by employing the mixing hopper in the combustion chamber, the airflow mixing effect is improved, and it can be used in the combustion chamber for a long time, making it suitable for high-temperature combustion chambers.

[0036] The aircraft engine of this embodiment includes the combustion chamber described above. Specifically, by employing the combustion chamber described above in the aircraft engine, long-term operation of the high-temperature combustion chamber can be achieved, which is highly practical and suitable for widespread promotion and application.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A mixing bucket, used for being installed on the wall of a flame tube, characterized in that, The mixing bucket includes an inner cone (100), an outer ring (200) surrounding the inner cone (100), and a bucket cap (300) for connecting the flame tube wall. The inner cone (100) and the bucket cap (300) enclose a mixing cavity for mixing high-temperature combustion gas and cooling gas flow. The inner cone (100) and the outer ring (200) enclose a cooling gap for cooling gas flow. The inner cone (100) is provided with cooling holes (400) that are respectively connected to the mixing cavity and the cooling gap for introducing cooling gas flow into the cooling gap to impact and cool the outer ring (200) and form a cooling gas film on the inner cone (100).

2. The mixing hopper according to claim 1, characterized in that, The axial length of the inner cone (100) is greater than the axial length of the outer ring (200).

3. The mixing hopper according to claim 2, characterized in that, The axial length of the outer ring (200) extending into the flame tube relative to the flame tube wall is K, where K is 1.0mm-2.0mm.

4. The mixing hopper according to claim 2, characterized in that, The difference between the axial length of the inner cone (100) extending into the flame tube relative to the flame tube wall and the axial length of the outer ring (200) extending into the flame tube relative to the flame tube wall is D, where D is 1.0mm-2.0mm.

5. The mixing hopper according to any one of claims 1-4, characterized in that, The included angle between the end face of the bucket cap (300) away from the flame tube wall and the axis of the cooling hole (400) is β, where β is 50°-75°.

6. The mixing hopper according to any one of claims 1-4, characterized in that, The inner cone angle of the inner cone (100) is α, where α is 5°-13°.

7. The mixing hopper according to any one of claims 1-4, characterized in that, The distance between the impact cooling point of the cooling airflow on the inner wall of the outer ring (200) and the cooling gap outlet is H, where H is 1.0mm-1.5mm.

8. The mixing hopper according to any one of claims 1-4, characterized in that, The outlet width of the cooling gap is B, which is 0.3mm-0.7mm.

9. A combustion chamber, characterized in that, Includes the mixing bucket as described in any one of claims 1-8.

10. An aircraft engine, characterized in that, Includes the combustion chamber as described in claim 9.

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