Efficient combustion organization system based on supercritical kerosene

Abstract

The invention relates to the technical field of aero-engines, in particular to an efficient combustion organization system based on supercritical kerosene. The device is characterized by comprising a combustion chamber outer ring arranged on the outer side of a combustion chamber and a floating wall arranged on the inner side of the combustion chamber, the floating wall and the combustion chamber outer ring are coaxially installed, and a supercritical kerosene injection circular seam, a cooling air injection circular seam and a stud hole are formed in the combustion chamber outer ring in the circumferential direction; the floating wall comprises floating tiles, the floating tiles are provided with studs, turbulent flow columns and gas film holes, and the studs fixedly connect the floating tiles to the combustion chamber outer ring through nuts and stud holes in the combustion chamber outer ring. According to the device, the characteristic that supercritical kerosene is easy to atomize is utilized, a floating wall structure is adopted, rotating detonation combustion is organized, and the problems that a conventional combustion chamber is high in air injection pressure drop, high in organization rotating detonation combustion atomization requirement, short in flame tube service life and the like are solved. The engine performance is improved, and the service life of the flame tube is prolonged.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, and in particular to a high-efficiency combustion organization device. Background Technology

[0002] Supercritical state is a special fluid state. Taking kerosene as an example, when both temperature and pressure exceed critical values, it is considered supercritical kerosene. At this point, the density of supercritical kerosene is close to that of liquid kerosene, while its energy density is higher than that of gaseous kerosene. Simultaneously, the viscosity of supercritical kerosene is only 1 / 12 to 1 / 4 that of liquid kerosene, and its diffusion coefficient is similar to that of gaseous kerosene, making it easy to atomize. Therefore, these excellent properties of supercritical kerosene are beneficial for kerosene injection and blending, enabling better efficient combustion and meeting the combustion requirements of future aerospace power plants.

[0003] The floating wall cooling structure is an advanced cooling technology. Its core lies in the fact that the outer layer and the inner layer serve as load-bearing and heat-bearing components, respectively. That is, the outer layer is an integral ring that bears mechanical loads, while the inner layer consists of multiple independently installed floating tiles that bear thermal loads. The two are connected by structures such as slots or studs. This solves the problem of uneven wall temperature of conventional combustion chamber flame tubes under high load conditions and the problem of low-cycle fatigue cracks caused by bearing both mechanical and thermal loads simultaneously.

[0004] Combustion processes in nature can be categorized into two forms based on the propagation characteristics of combustion waves: slow combustion and detonation. The self-sustaining detonation wave can be viewed as a shock wave carrying a chemical reaction; the leading shock wave compresses the reactants and triggers a violent chemical reaction behind the induction zone. Compared to slow combustion waves, detonation waves propagate faster, have a higher heat release rate, and lower entropy increase. Therefore, power plants based on detonation combustion possess higher thermal cycle efficiency and have become a research hotspot in the aerospace propulsion field.

[0005] In traditional aero-engine combustion chambers, to promote liquid kerosene atomization and good mixing with air, a portion of the incoming air is used for liquid kerosene shear atomization, resulting in a certain degree of air injection pressure drop and reducing engine performance. Furthermore, the inner wall of the traditional flame tube bears both mechanical and thermal loads, reducing its service life. Therefore, this invention proposes a high-efficiency combustion organization system based on supercritical kerosene. Utilizing the easy atomization characteristic of supercritical kerosene, it improves the mixing effect, reducing air injection pressure drop, enhancing engine performance, and solving the problem of high kerosene atomization requirements during detonation combustion. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-efficiency combustion organization system based on supercritical kerosene. By utilizing the easy atomization characteristics of supercritical kerosene, a floating wall cooling structure is adopted to organize rotary detonation combustion and an injection structure suitable for rotary detonation combustion is designed, which can improve engine performance and is expected to increase the total pressure recovery coefficient of the combustion chamber.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a high-efficiency combustion organization system based on supercritical kerosene, comprising an outer ring of combustion chamber disposed on the outer side of combustion chamber and a floating wall disposed on the inner side of combustion chamber, the floating wall being coaxially installed with the outer ring of combustion chamber, the outer ring of combustion chamber being provided with a supercritical kerosene injection ring slit, a cooling air injection ring slit and a stud hole along the circumferential direction, the supercritical kerosene injection ring slit being used to inject supercritical kerosene radially into combustion chamber; The floating wall includes floating tiles, which are provided with studs, turbulence columns and air film holes. The studs are fixed to the outer ring of the combustion chamber by nuts and stud holes on the outer ring of the combustion chamber.

[0008] Furthermore, multiple floating walls, supercritical kerosene injection ring seams, and cooling air injection ring seams are correspondingly arranged along the outer annular axis of the combustion chamber, and the number of supercritical kerosene injection ring seams is equal to the number of floating tiles in the axial direction; the supercritical kerosene injection ring seams are respectively arranged at the head of the combustion chamber and at axial intervals between adjacent floating tiles. The outer ring of the combustion chamber is divided into multiple segments in the axial direction by supercritical kerosene injection ring seams and cooling air injection ring seams. The outer ring of the combustion chamber is positioned by connecting and assembling with the outer casing of the combustion chamber. The stud holes are used to position the floating wall. The number of stud holes in the axial direction is equal to the number of floating tiles in the axial direction, and the number of stud holes in the circumferential direction is three times the number of floating tiles in the circumferential direction.

[0009] Furthermore, the number of cooling air injection annular slots is twice the number of floating tiles along the axial direction. The cooling air injection annular slots are respectively set on both sides of the stud of the floating tile in the axial direction. The axial distance between the cooling air injection annular slot and the central axis of the stud of the floating tile is 1 / 5 to 1 / 3 of the axial length of the floating tile. The cooling air injection ring is used to inject 20-25% of the total air volume of cooling air into the floating tiles radially to cool the floating wall and perform the first shearing and mixing with supercritical kerosene.

[0010] Furthermore, the floating tile has a circular arc structure along the circumference, and the floating tile has an angle of 5° to 15° with the central axis of the combustion chamber along the axial direction; the studs are evenly distributed in three places along the circumference of a floating tile, and the baffle column is located on the outside of the floating tile, with a gap of 1.5 to 2 mm between the top of the baffle column and the inner surface of the outer ring of the combustion chamber. The air film pores penetrate from the outer surface to the inner surface of the floating tile, and are used to allow cooling air to form an air film on the inner surface of the floating tile.

[0011] Furthermore, an inner column is coaxially arranged inside the outer ring of the combustion chamber, and a mainstream air inlet is provided at the head of the combustion chamber; the mainstream air inlet is coaxially arranged with the outer ring of the combustion chamber and is used to inject mainstream air, accounting for 75-80% of the total air volume, into the combustion chamber along the axial direction for a second shearing and mixing with supercritical kerosene.

[0012] Furthermore, the inner column is located at the center of the outer ring of the combustion chamber and is fixedly connected to the end of the combustion chamber. An annular channel is formed between the inner column and the floating wall to organize rotating detonation combustion in the form of an annular combustion chamber, suppressing the radial expansion of the rotating detonation wave and promoting the stable propagation of the rotating detonation wave.

[0013] The beneficial effects of this invention are as follows: The high-efficiency combustion organization system based on supercritical kerosene utilizes the excellent properties of supercritical kerosene, such as its easy atomization. It employs a floating wall cooling structure, organizes rotating detonation combustion, and designs an injection structure that facilitates increasing the axial height of the rotating detonation wave. This solves problems inherent in conventional combustion chambers, such as high air injection pressure drop during atomization, high requirements for liquid kerosene atomization in organizing rotating detonation combustion, and short service life due to the harsh operating environment of the combustion chamber flame tube. By organizing rotating detonation combustion and designing an injection structure that increases the axial height of the rotating detonation wave, it improves engine performance and extends the service life of the flame tube. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the isometric sectional view of the present invention; Figure 2 For the present invention Figure 1 Front view structural diagram; Figure 3 For the present invention Figure 2 Schematic diagram of the cross-sectional structure at point AA; Figure 4 For the present invention Figure 3 A magnified schematic diagram of the central part of the structure; Figure 5 For the present invention Figure 2 Schematic diagram of the cross-sectional structure at point BB; Figure 6 For the present invention Figure 5 A magnified schematic diagram of the central part of the structure; Figure 7 For the present invention Figure 1 A schematic diagram of the floating tile isometric structure.

[0015] In the diagram: 1. Outer ring of the combustion chamber; 1-1. Supercritical kerosene injection ring seam; 1-2. Cooling air injection ring seam; 1-3. Stud hole; 2. Floating wall; 2-1. Floating tile; 2-2. Stud; 2-3. Turbidity column; 2-4. Film gas hole; 3. Nut; 4. Main air intake inlet; 5. Inner column. Detailed Implementation

[0016] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0017] To achieve the above objectives, the present invention provides the following specific embodiments: Figure 1 , 2 As shown in Figure 3, the high-efficiency combustion organization system based on supercritical kerosene is characterized by including an outer combustion chamber ring 1 disposed on the outer side of the combustion chamber and a floating wall 2 disposed on the inner side of the combustion chamber. The floating wall 2 is coaxially installed with the outer combustion chamber ring 1. The outer combustion chamber ring 1 is provided with a supercritical kerosene injection ring slit 1-1, a cooling air injection ring slit 1-2 and a stud hole 1-3 along the circumferential direction. The supercritical kerosene injection ring slit 1-1 is used to inject supercritical kerosene radially into the combustion chamber. The floating wall 2 includes floating tiles 2-1. The floating tiles 2-1 are provided with studs 2-2, turbulence columns 2-3 and gas film holes 2-4. The studs 2-2 are fixed to the outer combustion chamber ring 1 by nuts 3 and stud holes 1-3 on the outer combustion chamber ring 1.

[0018] like Figure 4As shown, multiple floating walls 2, supercritical kerosene injection annular seams 1-1, and cooling air injection annular seams 1-2 are correspondingly arranged along the axial direction of the outer ring 1 of the combustion chamber. The number of supercritical kerosene injection annular seams 1-1 is equal to the number of floating tiles 2 along the axial direction. The supercritical kerosene injection annular seams 1-1 are respectively arranged at the head of the combustion chamber and at axial intervals between adjacent floating tiles. The outer ring 1 of the combustion chamber is divided into multiple segments along the axial direction by supercritical kerosene injection annular seams 1-1 and cooling air injection annular seams 1-2. The outer ring 1 of the combustion chamber is positioned by connecting and assembling with the outer casing of the combustion chamber. The number of cooling air injection annular seams 1-2 is twice the number of floating tiles along the axial direction. 2. The studs 2-2 of the floating tile 2-1 are respectively set on both sides in the axial direction. The axial distance between the cooling air injection annular slit 1-2 and the central axis of the stud 2-2 of the floating tile is 1 / 5 to 1 / 3 of the axial length of the floating tile 2-1. The cooling air injection annular slit 1-2 is used to inject cooling air accounting for 20 to 25% of the total air volume into the floating tile 2-1 radially to cool the floating wall 2 and perform the first shearing and mixing with supercritical kerosene. The stud holes 1-3 are used to position the floating wall 2. The number of stud holes 1-3 in the axial direction is equal to the number of stud holes 2-1 in the axial direction. The number of stud holes 1-3 in the circumferential direction is 3 times the number of stud holes 2-1 in the circumferential direction.

[0019] like Figure 7 As shown, the floating tile 2-1 has a circular arc structure along the circumference, and the floating tile 2-1 has an angle of 5° to 15° with the central axis of the combustion chamber along the axial direction; three studs 2-2 are evenly distributed around the circumference of a floating tile 2-1; the baffle column 2-3 is located on the outside of the floating tile 2-1, and there is a gap of about 1.5 to 2 mm between the top of the baffle column 2-3 and the inner surface of the outer ring 1 of the combustion chamber; the air film hole 2-4 penetrates through the outer surface to the inner surface of the floating tile 2-1, and is used to form an air film of cooling gas on the inner surface of the floating tile.

[0020] like Figure 5 , 6As shown, an inner column 5 is coaxially arranged inside the outer ring 1 of the combustion chamber, and a mainstream air inlet 4 is provided at the head of the combustion chamber. The mainstream air inlet 4 is coaxially arranged with the outer ring 1 of the combustion chamber and is used to inject mainstream air, accounting for 75-80% of the total air volume, into the combustion chamber along the axial direction for a second shearing and mixing with supercritical kerosene. The inner column 5 is located at the center of the outer ring of the combustion chamber and is fixedly connected to the head of the combustion chamber. An annular channel is formed between the inner column 5 and the floating wall 2, which organizes rotating detonation combustion in the form of an annular combustion chamber, suppresses the radial expansion of the rotating detonation wave, and promotes the stable propagation of the rotating detonation wave. When the inner column 5 is removed, the floating wall 2 forms a radial expansion channel, which organizes rotating detonation combustion in the form of an empty cylinder combustion chamber. The radial expansion of the rotating detonation wave leads to an increased tendency for decoupling, but it reduces the weight of the combustion chamber to a certain extent and avoids the cooling problem of the inner column 5.

[0021] See Figure 1 and Figure 3 Supercritical kerosene is radially injected into the combustion chamber through supercritical kerosene injection annular slot 1-1. For the incoming air, 20% is injected into the combustion chamber through cooling air injection annular slot 1-2, extending the service life of the floating tiles 2-1 through impact cooling and film cooling, and performing the first shear mixing of the supercritical kerosene. The remaining 80% is axially injected into the combustion chamber through the main air intake inlet 4, performing the second shear mixing of the supercritical kerosene. When the inner column 5 is present, the mixture is ignited by a spark plug or pre-explosion tube, organizing rotational detonation combustion in the annular combustion chamber. At this time, the use of supercritical kerosene reduces the air injection pressure drop caused by atomization, the floating wall cooling structure extends the service life of the combustion chamber flame tube, and the organization of rotational detonation combustion improves the engine thermal cycle efficiency. By setting the axial injection structure, the axial height of the rotational detonation wave is increased, which is expected to improve the total pressure recovery coefficient of the combustion chamber.

[0022] The aforementioned high-efficiency combustion organization system based on supercritical kerosene utilizes the easy atomization characteristics of supercritical kerosene during operation, employs a floating wall cooling structure, organizes rotary detonation combustion, and designs an injection structure suitable for rotary detonation combustion, which can improve engine performance and is expected to increase the total pressure recovery coefficient of the combustion chamber.

[0023] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-efficiency combustion organization system based on supercritical kerosene, characterized in that, The combustion chamber outer ring is provided with a supercritical kerosene injection ring slot, a cooling air injection ring slot and a stud hole in the circumferential direction, the supercritical kerosene injection ring slot is used for radially injecting supercritical kerosene into the combustion chamber, and the cooling air injection ring slot is used for radially injecting cooling air into the combustion chamber. The floating wall comprises floating tiles, the floating tiles are provided with studs, spoiler columns and air film holes, the studs are fixedly connected to the combustion chamber outer ring through nuts and the stud holes in the combustion chamber outer ring.

2. A high efficiency combustion organization system based on supercritical kerosene as claimed in claim 1, characterized in that, The floating wall, the supercritical kerosene injection ring slot and the cooling air injection ring slot are correspondingly provided in multiple in the axial direction of the combustion chamber outer ring, the number of the supercritical kerosene injection ring slots is equal to the number of the floating tiles in the axial direction, and the supercritical kerosene injection ring slots are arranged at the axial interval positions of the combustion chamber head and the adjacent floating tiles. The combustion chamber outer ring is divided into multiple segments in the axial direction by the supercritical kerosene injection ring slots and the cooling air injection ring slots, and the combustion chamber outer ring is positioned through the connection assembly with the casing outside the combustion chamber. The stud holes are used for positioning the floating wall, the number of the stud holes in the axial direction is equal to the number of the floating tiles in the axial direction, and the number of the stud holes in the circumferential direction is 3 times the number of the floating tiles in the circumferential direction.

3. A high efficiency combustion organization system based on supercritical kerosene as claimed in claim 2, wherein, The number of the cooling air injection ring slots is 2 times the number of the floating tiles in the axial direction, the cooling air injection ring slots are arranged on both sides of the studs of the floating tiles in the axial direction, and the axial distance between the cooling air injection ring slots and the central axis of the studs of the floating tiles is 1 / 5 to 1 / 3 of the axial length of the floating tiles. The cooling air injection ring slots are used for radially injecting 20 to 25% of the total amount of cooling air into the floating tiles to cool the floating wall and to perform the first shearing and mixing with the supercritical kerosene.

4. A high efficiency combustion organization system based on supercritical kerosene as claimed in claim 1, wherein, The floating tiles are in the form of a circular arc in the circumferential direction, and the floating tiles form an angle of 5 to 15 degrees with the central axis of the combustion chamber in the axial direction; the studs are uniformly distributed in three in the circumferential direction of one floating tile, the spoiler columns are located outside the floating tiles, and the top of the spoiler columns is spaced apart from the inner surface of the combustion chamber outer ring by a gap of 1.5 to 2 mm. The air film holes penetrate through the outer surface to the inner surface of the floating tiles, and are used for forming an air film on the inner surface of the floating tiles.

5. A high efficiency combustion organization system based on supercritical kerosene according to any one of claims 1 to 4, characterized in that, The inner column is coaxially arranged in the combustion chamber outer ring, and the combustion chamber head is provided with a main flow air inlet; the main flow air inlet is coaxially arranged with the combustion chamber outer ring, and is used for axially injecting 75 to 80% of the total amount of main flow air into the combustion chamber to perform the second shearing and mixing with the supercritical kerosene.

6. A high efficiency combustion organization system based on supercritical kerosene as claimed in claim 5, wherein, The inner column is arranged at the center of the combustion chamber outer ring and is fixedly connected to the end of the combustion chamber, an annular channel is formed between the inner column and the floating wall, the rotary detonation combustion is organized in the form of an annular combustion chamber, the radial expansion of the rotary detonation wave is inhibited, and the stable propagation of the rotary detonation wave is promoted.

Images