Gas-liquid two-phase rotary detonation combustion chamber for inhibiting pressure return

Abstract

The invention discloses a gas-liquid two-phase rotary detonation combustion chamber for inhibiting pressure return, relates to the technical field of pressure return inhibition of combustion chambers of air-breathing rotary detonation engines, and aims to solve the problem that pressure return inhibition and ram loss cannot be considered in the conventional rotary detonation combustion. The combustor comprises an air inlet pressure stabilizing section, a pressure restraining section and a combustion section which are sequentially communicated, one side of a Tesla valve flow channel in the pressure restraining section is communicated with a gas oxidizing agent channel of the air inlet pressure stabilizing section, and the other side of the Tesla valve flow channel is communicated with a combustion channel of the combustion section. A main flow channel of the Tesla valve flow channel is formed by a gap between the Tesla valve shell and the pressure restraining section shell, a pressure return channel of the Tesla valve flow channel is formed by a gap between the Tesla valve shell and the combustion chamber inner column, and the liquid fuel cavity is located between the Tesla valve flow channel and the combustion channel. According to the rotary detonation combustion chamber, the fluid diode characteristic of the Tesla valve is used for effectively restraining detonation pressure return, the total pressure loss of air inlet is reduced, and the performance of the rotary detonation combustion chamber is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of air-breathing rotating detonation engines, and particularly to the pressure feedback suppression technology of gas-liquid two-phase rotating detonation combustors. Background Art

[0002] With the rapid development of the field of power propulsion, the performance requirements for thermal engines are increasing day by day. In conventional power propulsion systems, the combustor mostly adopts the isobaric combustion mode. The isobaric combustion process is accompanied by a large entropy increase, which directly leads to the fact that the cycle efficiency of modern Brayton cycle thermal engines is difficult to break through the existing level and is severely restricted by the development of new material technologies. Detonation combustion is a new type of pressurized combustion mode, and its combustion characteristics are that the leading shock wave is highly coupled with the chemical reaction zone. During the combustion process, the pressure and temperature increase suddenly, and the volume remains basically unchanged, approximately equal to isochoric combustion, with obvious pressurization characteristics, which can greatly reduce the entropy increase during the combustion process and theoretically can significantly improve the cycle thermal efficiency of the power propulsion system. The rotating detonation combustor is a pressurized combustor based on detonation combustion, which has the advantages of single ignition, compact structure, stable power output, etc., and has received extensive attention and research in recent years.

[0003] During the actual operation of the rotating detonation combustor, there are high-frequency and high-intensity detonation wave pressure signals, and the pressure feedback will seriously affect the normal air intake of the combustor and the stable operation of the upstream components. Suppressing the inlet pressure feedback is an essential step for the two-phase rotating detonation engine to move towards application. Traditional methods mostly use a converging-diverging inlet to generate a normal shock wave in the diverging section to suppress the pressure feedback. However, this method will bring a large total pressure loss and is not conducive to improving the total pressure gain of the combustor. Reducing the shock wave intensity at the diverging section to reduce the total pressure loss, but the result is a stronger detonation wave pressure feedback. Therefore, it is necessary to combine an effective pressure feedback suppression structure to improve the overall performance of the combustor. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that the existing rotating detonation combustion cannot take into account both the pressure feedback suppression and the ram pressure loss, resulting in the decline of the overall performance of the combustor, and to provide a new type of gas-liquid two-phase rotating detonation combustor for suppressing pressure feedback.

[0005] A gas-liquid two-phase rotating detonation combustor for suppressing pressure backflow according to the present invention includes an intake air pressure stabilizing section, a pressure suppression section, and a combustion section that are connected in sequence; the intake air pressure stabilizing section includes a gas oxidant inlet and a gas oxidant passage connected to the gas oxidant inlet; the combustion section includes a combustion passage; the pressure suppression section includes a liquid fuel inlet, a liquid fuel chamber, liquid fuel holes, and a Tesla valve flow passage. The liquid fuel inlet, the liquid fuel chamber, and the liquid fuel holes are connected in sequence. One side of the Tesla valve flow passage is connected to the gas oxidant passage, and the other side is connected to the combustion passage. The gap between the Tesla valve housing and the outer shell of the pressure suppression section forms the main flow passage of the Tesla valve flow passage, and the gap between the Tesla valve housing and the inner column of the combustor forms the pressure backflow passage of the Tesla valve flow passage. The liquid fuel chamber is located between the Tesla valve flow passage and the combustion passage.

[0006] Optionally, the central axis of the pressure backflow passage coincides with the central axis of the combustion passage, and the included angle between the main flow passage and the central axis of the combustion passage is 30°-45°.

[0007] Optionally, the number of the liquid fuel holes is 90-120, and they are arranged circumferentially around the inner column of the combustor in the combustion chamber.

[0008] Optionally, the diameter of the liquid fuel hole is 0.3-0.5 mm.

[0009] Optionally, a pressure sensor mounting hole is provided on the outer shell of the combustion section.

[0010] Optionally, the diameter of the pressure sensor mounting hole is 14 mm.

[0011] By adding a Tesla valve injection structure to the gas-liquid two-phase rotating detonation combustor in the present invention, this structure is divided into two parts: a main flow passage and a reflux passage, and has the characteristics of a "fluid diode", which can effectively suppress the detonation pressure backflow, reduce the total intake air pressure loss, and improve the performance of the rotating detonation combustor. Description of the Drawings

[0012] Figure 1 is a schematic diagram of the overall structure of a gas-liquid two-phase rotating detonation combustor for suppressing pressure backflow according to an embodiment of the present application;

[0013] Figure 2 is a schematic sectional structure diagram of a gas-liquid two-phase rotating detonation combustor for suppressing pressure backflow according to an embodiment of the present application;

[0014] Figure 3 is a schematic structural diagram of a Tesla valve flow passage according to an embodiment of the present application. Detailed Embodiments

[0015] The following specific examples illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0016] As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be further understood that the terms "comprising", "including" indicate the presence of the stated features, operations, elements, components, items, kinds, and / or groups, but do not exclude the presence, occurrence or addition of one or more other features, operations, elements, components, items, kinds, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or meaning any one or any combination. Thus, "A, B or C" or "A, B and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". Exceptions to this definition occur only when the combination of elements, functions or operations are mutually exclusive in some way.

[0017] Aiming at the problem that the existing rotating detonation combustion cannot take into account both the suppression of pressure feedback and the ram loss, resulting in the decline of the overall performance of the combustion chamber, the present invention provides a gas-liquid two-phase rotating detonation combustion chamber for suppressing pressure feedback, which can effectively suppress the detonation pressure feedback, reduce the total intake pressure loss, and improve the performance of the rotating detonation combustion chamber.

[0018] As Figure 1 and Figure 2 shown, the gas-liquid two-phase rotating detonation combustion chamber for suppressing pressure feedback in the embodiment of the present application includes: an intake pressure stabilizing section 1, a pressure suppressing section 2, and a combustion section 3.

[0019] Fixed flanges are welded on the outer wall surfaces of the outlet of the intake pressure stabilizing section 1, the inlet and outlet of the pressure suppressing section 2, and the inlet and outlet of the combustion section 3 for connecting the three. A fixed flange is welded at the outlet of the combustion section 3 for connecting the tail gas recovery device.

[0020] The intake pressure stabilizing section 1 includes a gas oxidant inlet 11 and a gas oxidant channel 12. The inner column 4 of the combustion chamber is divided into a head, a middle part, and a tail part. The head is conical, the tip of the cone faces the outside of the combustion chamber, and the tip of the cone is located at the center of the end face of the pressure stabilizing section housing 13. The end of the pressure stabilizing section housing 13 serves as the gas oxidant inlet 11 of the intake pressure stabilizing section 1. Inside the pressure stabilizing section housing 13, the gap between the pressure stabilizing section housing 13 and the head of the inner column 4 of the combustion chamber serves as the gas oxidant channel 12.

[0021] The combustion section 3 includes a combustion channel 31, and an annular channel formed between the combustion section outer shell 32 and the middle part of the inner column 4 in the combustion chamber serves as the combustion channel 31. The combustion section outer shell 32 is provided with a pressure sensor mounting hole 5, and the aperture of the pressure sensor mounting hole 5 is preferably 14 mm.

[0022] Between the intake air pressure stabilizing section 1 and the combustion section 3 is a pressure suppression section 2. As Figure 2 and Figure 3 shown, the pressure suppression section 2 includes a liquid fuel inlet 21, a liquid fuel chamber 22, liquid fuel holes 23, and a Tesla valve flow channel 24.

[0023] The liquid fuel inlet 21, the liquid fuel chamber 22, and the liquid fuel holes 23 are all cavities / channels machined on the pressure suppression section outer shell 25. The liquid fuel inlet 21, the liquid fuel chamber 22, and the liquid fuel holes 23 are connected in sequence. The liquid fuel inlet 21 extends outward to the outer surface of the pressure suppression section outer shell 25, and the liquid fuel holes 23 extend inward to the combustion channel 31. The liquid fuel chamber 22 is located between the Tesla valve flow channel 24 and the combustion channel 31, and the Tesla valve flow channel 24 is located between the gas oxidant channel 12 and the combustion channel 31. The Tesla valve flow channel 24 is formed by the gap between the pressure suppression section outer shell 25, the inner column 4 in the combustion chamber, and the Tesla valve housing 26. Specifically, the gap between the Tesla valve housing 26 and the pressure suppression section outer shell 25 forms the main flow channel 27 of the Tesla valve flow channel 24, and the gap between the Tesla valve housing 26 and the inner column 4 in the combustion chamber forms the pressure feedback channel 28 of the Tesla valve flow channel 24. The pressure feedback channel 28 is coaxial with the combustion channel 31, and the included angle between the main flow channel 27 and the central axis of the combustion channel 31 is 30° - 45°. The liquid fuel holes 23 connect the liquid fuel chamber 22 and the combustion channel 31. The number of the liquid fuel holes 23 is 90 - 120, and they are arranged circumferentially around the inner column 4 in the combustion chamber. The diameter of the fuel holes is about 0.3 - 0.5 mm.

[0024] The working process and principle of the embodiments of the present invention are described below to facilitate the understanding of the advantages of the present invention. The gaseous fuel enters the intake pressure stabilization section 1 through the gas oxidant inlet 11 and enters the main flow channel 17 of the Tesla valve through the pressure suppression section 2, and finally enters the combustion channel 31. The liquid fuel enters the combustion channel 31 through the liquid fuel holes 23 on the liquid fuel chamber 22 and is mixed and burned with the gaseous fuel. When the detonation pressure is transmitted back, most of the transmitted-back pressure first enters the Tesla valve pressure transmission-back channel 28 from the combustion channel 31. During the propagation of the transmitted-back pressure inside the pressure transmission-back channel (28), complex reflections and refractions will occur. When it propagates to the intersection with the main flow channel 27, the remaining transmitted-back pressure is already very small. Then, through the flow guiding effect of the Tesla valve housing 25, it is incorporated into the forward flow (entering the main flow channel 27). Finally, the remaining transmitted-back pressure is extremely small. This part of the transmitted-back pressure enters the gas oxidant channel 12 of the intake pressure stabilization section 1. With the effect of a long transmission-back distance, the transmitted-back pressure is further dissipated, which can effectively suppress the disturbance of the detonation pressure transmitted back to the gas oxidant inlet 11. Part of the transmitted-back pressure can be further weakened in the intake pressure stabilization section 1, further enhancing the uniformity and stability of the gas fuel injection and improving the operating performance of the rotating detonation combustor.

[0025] In the present invention, the combination of the intake pressure stabilization section 1 and the pressure suppression section 2 can effectively weaken the detonation pressure transmitted back, reduce the total pressure loss at the inlet, improve the stability of the inlet flow field and the overall total pressure gain of the combustor, and can also improve the intake uniformity of the rotating detonation combustor and reduce the intake recovery time.

[0026] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly explaining the present invention and are not limitations on the embodiments of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the embodiments here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A gas-liquid two-phase rotating detonation combustor for suppressing pressure backpropagation, characterized in that, It includes an intake pressure stabilizing section (1), a pressure suppressing section (2), and a combustion section (3) that are connected in sequence. The intake pressure stabilizing section (1) includes a gas oxidant inlet (11) and a gas oxidant passage (12) connected to the gas oxidant inlet (11). The combustion section (3) includes a combustion passage (31). The pressure suppressing section includes a liquid fuel inlet (21), a liquid fuel chamber (22), liquid fuel holes (23), and a Tesla valve passage (24). The liquid fuel inlet (21), the liquid fuel chamber (22), and the liquid fuel holes (23) are connected in sequence. One side of the Tesla valve passage (24) is connected to the gas oxidant passage (12), and the other side is connected to the combustion passage (31). The gap between the Tesla valve housing (26) and the pressure suppressing section outer shell (25) forms the main passage (27) of the Tesla valve passage (24). The gap between the Tesla valve housing (26) and the combustion chamber inner column (4) forms the pressure feedback passage (28) of the Tesla valve passage (24). The liquid fuel chamber (22) is located between the Tesla valve passage (24) and the combustion passage (31).

2. The combustion chamber according to claim 1, characterized in that, The central axis of the pressure feedback passage (28) coincides with the central axis of the combustion passage (31), and the angle between the main passage (27) and the central axis of the combustion passage (31) is 30° - 45°.

3. The combustion chamber according to claim 1, characterized in that, The number of the liquid fuel holes (23) is 90 - 120, and they are arranged circumferentially around the combustion chamber inner column (4) of the combustion chamber.

4. The combustion chamber according to claim 3, characterized in that, The diameter of the liquid fuel hole (23) is 0.3 - 0.5 mm.

5. The combustion chamber according to claim 1, characterized in that, A pressure sensor mounting hole (5) is provided in the outer shell of the combustion section (3).

6. The combustion chamber according to claim 5, characterized in that, The diameter of the pressure sensor mounting hole (5) is 14 mm.

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