A single-sided single-inlet trapped-vortex cavity interstage combustor

Abstract

The application discloses a single-sided single-air-inlet trapped-vortex cavity interstage combustion chamber, which comprises an outer casing, an inner casing, N cavity modules, N main flow oil injection rods and a flow regulation module; the cavity module comprises a shell, a cavity oil injection rod, an evaporation pipe, a flow distribution plate, a first flow guide pipe, a second flow guide pipe and a radial support plate. The application guarantees flame stability and combustion efficiency through the trapped-vortex cavity flame stabilization technology, and can increase unit thrust and improve thermal efficiency under the condition that the fuel consumption rate is reduced compared with a conventional afterburner.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aero-engine, in particular to a single-sided single-inlet trapped-vortex cavity interstage combustion chamber. BACKGROUND

[0002] Modern comprehensive high-performance aero-gas turbine engine develops towards high-pressure ratio, high turbine inlet temperature, low pollution, high reliability and long life. According to the Brayton cycle, the improvement of engine performance must increase the overall pressure ratio of the engine while increasing the turbine inlet temperature. At present, the flow instability phenomena such as rotating stall and surge of the compressor at high pressure ratio are difficult to solve, and the turbine inlet temperature is also limited by the turbine material, which restricts the development of aero-engine technology. According to the current research, adding an interstage combustion chamber between the high and low pressure turbines is an effective method to improve the performance of the engine under the existing technical conditions.

[0003] The inlet of the interstage combustion chamber is located at the outlet of the high-pressure turbine rotor, and its speed is usually much higher than the outlet speed of the conventional compressor, which is difficult to stabilize the flame. At the same time, the interstage combustion chamber is located in the transition section between the high and low pressure turbines, and the axial distance is limited, so it is impossible to install a diffuser for speed reduction. In order to meet the requirements of the overall loss of the engine, it is also impossible to use a conventional swirler to organize the flame and stabilize the combustion. At present, most of the researches use trapped-vortex cavity flame stabilization technology.

[0004] The trapped-vortex combustion chamber mainly uses the recirculation zone generated by the trapped-vortex cavity structure to stabilize the flame. Foreign researches have found that the trapped-vortex combustion chamber has very good performance: compared with conventional technology, the ignition performance, lean blowout performance and high-altitude ignition performance are improved by 50%; the nitrogen oxide emission is reduced by 40% to 60% compared with the 1996 ICAO standard CAEP2; and the working range of the combustion efficiency reaching or exceeding 99% is widened by more than 40%. The United States Air Force, Navy, Department of Energy and NASA are exploring the transplantation of this technology to possible military small-bypass-ratio turbofan engines, commercial large-bypass-ratio turbofan engines, industrial and ship gas turbines. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a single-sided single-inlet trapped-vortex cavity interstage combustion chamber to improve the low-pressure turbine power to increase the unit thrust and improve the thermal efficiency under the condition that the specific fuel consumption is approximately unchanged.

[0006] The present application adopts the following technical solutions to solve the above technical problems:

[0007] A single-sided single-inlet trapped-vortex cavity interstage combustion chamber, comprising an outer casing, an inner casing, N cavity modules, N main flow oil injection rods, and a flow regulation module, N is a natural number greater than or equal to 3.

[0008] The outer casing and the inner casing are both open at both ends, have a circular cross section, and gradually increase from upstream to downstream, and the outer casing and the inner casing are coaxially arranged;

[0009] The outer casing is circumferentially and uniformly provided with N mounting through slots corresponding to the recess cavity modules one by one;

[0010] The recess cavity module comprises a shell, a recess cavity oil injection rod, an evaporation pipe, a flow distribution plate, a first flow guide pipe, a second flow guide pipe and a radial support plate;

[0011] The shell comprises a front wall, a rear wall, an outer wall, a first side wall and a second side wall, wherein the front wall and the rear wall are fan-shaped, the first side wall and the second side wall are symmetrical rectangles, the outer wall is an arc surface coaxial with the outer casing, the four sides of the outer wall are respectively and perpendicularly fixedly connected with the front wall, the first side wall, the rear wall and the second side wall, and the front wall, the first side wall, the rear wall and the second side wall are sequentially and first fixedly connected;

[0012] The inner side of the shell and the outer casing are fixedly and tightly connected at the corresponding mounting through slots;

[0013] The front wall is provided with a first through slot for mounting the evaporation pipe and a second through slot for cooperating with the first flow guide pipe, and the first through slot and the second through slot are both strip-shaped and arranged in parallel, and the second through slot is located inside the first through slot;

[0014] The evaporation pipe is closed at both ends and fixedly and tightly connected with the shell through the first through slot, and both ends and the side wall of the evaporation pipe are partially located outside the shell and partially located inside the shell, and a plurality of air outlets are uniformly arranged on the side wall of the evaporation pipe inside the shell along the length direction of the evaporation pipe;

[0015] The inlet of the first flow guide pipe is arranged on the inner wall of the outer casing, the outlet penetrates through the outer casing and is fixedly and tightly connected with the second through slot of the front wall of the shell, and the outlet width of the first flow guide pipe is greater than or equal to the length of the evaporation pipe;

[0016] The second flow guide pipe is arranged outside the outer casing, one end of the second flow guide pipe is communicated with the first flow guide pipe, and the other end of the second flow guide pipe is communicated with the part of the evaporation pipe located outside the shell;

[0017] The recess cavity oil injection rod extends into the second flow guide pipe and is used for supplying oil to the recess cavity module;

[0018] The flow distribution plate is arranged in the evaporation pipe, is fixedly connected with the inner wall of the evaporation pipe and is coplanar with the front wall, and is used for distributing the oil gas of the second flow guide pipe entering the part of the evaporation pipe located outside the shell, so that the oil gas enters the part of the evaporation pipe located inside the shell from both sides of the flow distribution plate;

[0019] The radial support plate adopts a bluff body stabilizer, is arranged between the outer casing and the inner casing, is fixedly connected to the inner wall of the outer casing at one end and is fixedly connected to the outer wall of the inner casing at the other end, the outer edge of the radial support plate faces upstream, the inner edge is coplanar with the inner wall of the front wall, and the radial support plate is circumferentially staggered with the second through groove;

[0020] The N main flow oil injection rods are circumferentially and uniformly arranged on the outer casing upstream of the cavity module shell, and each rod has one end extending into the space between the outer casing and the inner casing for main flow oil supply;

[0021] The flow regulation module is arranged downstream of the N cavity modules and comprises a plurality of flow regulation vanes.

[0022] The plurality of flow regulation vanes are circumferentially arranged between the outer casing and the inner casing, each vane has one end fixedly connected to the outer casing and the other end fixedly connected to the inner casing, and the plurality of flow regulation vanes are used in cooperation with the radial support plates of the N cavity modules for flow regulation.

[0023] As a further optimization scheme of the single-sided single-inlet trapped-vortex cavity inter-stage combustion chamber, N is 5.

[0024] As a further optimization scheme of the single-sided single-inlet trapped-vortex cavity inter-stage combustion chamber, the scheme further comprises a plurality of stabilizing vanes arranged downstream of the N cavity modules.

[0025] The plurality of stabilizing vanes are circumferentially arranged between the outer casing and the inner casing, each vane has one end fixedly connected to the outer casing and the other end fixedly connected to the inner casing, and the plurality of stabilizing vanes are used for reinforcing the connection between the outer casing and the inner casing and for flow regulation.

[0026] Compared with the prior art, the technical scheme of the present application has the following technical effects:

[0027] 1. The turbine inter-stage combustion chamber added between the high-pressure turbine and the low-pressure turbine first rotor can make the gas with energy loss after passing through the high-pressure turbine further combust and heat up, thereby improving the work capacity of the low-pressure turbine.

[0028] 2. The trapped-vortex cavity flame stabilization technology guarantees the flame stabilization performance and the combustion efficiency.

[0029] 3. The present application can increase the unit thrust and improve the thermal efficiency under the condition of reducing the fuel consumption rate compared with the conventional afterburner. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a schematic diagram of the three-dimensional structure of the present application;

[0031] Figure 2 is a schematic diagram of the half-section structure of the outer casing of the present application;

[0032] Figure 3This is a schematic diagram of the structure of the present invention in half section;

[0033] Figure 4 This is a schematic diagram of a partial cross-section of the cavity module in this invention;

[0034] Figure 5 This is a schematic diagram of the airflow direction in the cross-section without radial support plates in this invention;

[0035] Figure 6 This is a schematic diagram of the airflow direction of the radial support plate section in this invention.

[0036] In the figure, 1-outer casing, 2-inner casing, 3-housing of the cavity module, 4-cavity injector rod, 5-mainstream injector rod, 6-rectifier blade, 7-stabilizing blade, 8-first guide pipe, 9-radial support plate, 10-second guide pipe, 11-evaporator pipe, 12-split plate, 13-air outlet on the evaporator pipe, 14-front wall of the housing, 15-outer wall of the housing, 16-rear wall of the housing. Implementation

[0037] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings:

[0038] This invention can be implemented in many different forms and should not be considered limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully express the scope of the invention to those skilled in the art. In the drawings, components are enlarged for clarity.

[0039] It should be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, and / or parts, these elements, components, and / or parts are not limited by these terms. These terms are merely used to distinguish elements, components, and / or parts from one another. Therefore, the first element, component, and / or part discussed below may be a second element, component, or part without departing from the teachings of this invention.

[0040] like Figure 1 , Figure 2 As shown, the present invention discloses a single-sided single-intake vortex concave cavity interstage combustion chamber, including an outer casing, an inner casing, N cavity modules, N main fuel injection rods, and a rectifier module, where N is a natural number greater than or equal to 3;

[0041] Both the outer casing and the inner casing are open at both ends, have a circular cross-section that gradually increases in size from upstream to downstream, and are coaxially arranged.

[0042] The outer casing is uniformly provided with N mounting slots that correspond one-to-one with the cavity modules in the circumferential direction;

[0043] like Figure 3As shown, the cavity module comprises a shell, a cavity oil injection rod, an evaporation pipe, a flow distribution plate, a first flow guide pipe, a second flow guide pipe and a radial support plate;

[0044] The shell comprises a front wall, a rear wall, an outer wall, a first side wall and a second side wall, wherein the front wall and the rear wall are fan-shaped, the first side wall and the second side wall are symmetrical rectangles, the outer wall is an arc surface coaxial with the outer casing, the four sides of the outer wall are respectively and perpendicularly fixedly connected with the front wall, the first side wall, the rear wall and the second side wall, and the front wall, the first side wall, the rear wall and the second side wall are sequentially and perpendicularly fixedly connected;

[0045] The inner side of the shell and the outer casing are fixedly and tightly connected at the corresponding installation through slots thereof;

[0046] As shown, Figure 4 the front wall is provided with a first through slot for mounting the evaporation pipe and a second through slot for cooperating with the first flow guide pipe, the first through slot and the second through slot are both strip-shaped and arranged in parallel, and the second through slot is located inside the first through slot;

[0047] The evaporation pipe is closed at both ends and fixedly and tightly connected with the shell through the first through slot, the two ends and the side wall of the evaporation pipe are both partially located outside the shell and partially located inside the shell, and a plurality of air outlets are uniformly arranged on the side wall of the evaporation pipe inside the shell along the length direction of the evaporation pipe;

[0048] The inlet of the first flow guide pipe is arranged on the inner wall of the outer casing, the outlet is fixedly and tightly connected with the second through slot of the front wall of the shell after penetrating through the outer casing, and the outlet width of the first flow guide pipe is greater than or equal to the length of the evaporation pipe;

[0049] The second flow guide pipe is arranged outside the outer casing, one end of the second flow guide pipe is communicated with the first flow guide pipe, and the other end of the second flow guide pipe is communicated with the part of the evaporation pipe located outside the shell;

[0050] The cavity oil injection rod extends into the second flow guide pipe and is used for supplying oil to the cavity module;

[0051] The flow distribution plate is arranged in the evaporation pipe, fixedly connected with the inner wall of the evaporation pipe and coplanar with the front wall, and used for distributing the oil gas of the second flow guide pipe entering the part of the evaporation pipe located outside the shell to enter the part of the evaporation pipe located inside the shell from both sides of the flow distribution plate;

[0052] The radial support plate is a bluff body stabilizer, arranged between the outer casing and the inner casing, fixedly connected with the inner wall of the outer casing at one end and fixedly connected with the outer wall of the inner casing at the other end, the outer edge of the radial support plate faces the upstream, the inner edge of the radial support plate is coplanar with the inner wall of the front wall, and the radial support plate is circumferentially staggered with the second through slot;

[0053] The N main flow oil injection rods are circumferentially and uniformly arranged on the outer casing upstream of the cavity module shell, and one end of each rod extends into the space between the outer casing and the inner casing for main flow fuel supply;

[0054] The rectification module is arranged downstream of the N cavity modules, and comprises a plurality of rectification vanes;

[0055] The plurality of rectification vanes are circumferentially arranged between the outer casing and the inner casing, and one end of each vane is fixed to the outer casing and the other end is fixed to the inner casing, for rectification in cooperation with the radial support plates of the N cavity modules.

[0056] N is preferably 5, and a plurality of stabilizing vanes can be further arranged downstream of the N cavity modules;

[0057] The plurality of stabilizing vanes are circumferentially arranged between the outer casing and the inner casing, and one end of each vane is fixed to the outer casing and the other end is fixed to the inner casing, for reinforcing the connection between the outer casing and the inner casing and rectification.

[0058] Please refer to Figure 1 , Figure 5 and Figure 6 , the working process of the present application is as follows: air enters the combustion chamber from the inlet, and is divided into main flow and cavity flow after passing through the first flow guide pipe; the cavity flow is further divided into a flow directly entering the cavity and a flow entering the evaporation pipe; the shell of the cavity module stabilizes the flame; the radial support plate transmits the flame; the main flow oil injection rod provides fuel for the main flow; the fuel provided by the cavity oil injection rod is mixed with air in the evaporation pipe and then enters the shell of the cavity module through the gas outlet of the evaporation pipe.

[0059] Please refer to Figure 5 , the gas entering the shell of the cavity module through the first flow guide pipe forms a counterclockwise stationary vortex, and the fuel supplied through the evaporation pipe can be stably combusted.

[0060] Please refer to Figure 6 , the radial support plate not only transmits the flame, but also acts as a main flow ignition source. Similarly, a low-speed backflow area is formed in the wake flow of the radial support plate, which is beneficial to flame transmission and flame stability, and increases the contact area between the high-temperature mixed gas in the cavity and the main flow mixed gas, thereby increasing the ignition source area and improving the efficiency.

[0061] As can be understood by those skilled in the art, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with those in the context of the prior art, and unless otherwise defined, should not be interpreted in an idealized or overly formal sense.

[0062] The above detailed description of the specific embodiments of the present application is provided for the purpose of further explaining the objects, technical solutions and advantages of the present application, and it should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A single-sided single-inlet trapped-vortex cavity interstage combustor characterized by, The outer casing, the inner casing, N cavity modules, N main flow oil injection rods, and a flow straightening module, wherein N is a natural number greater than or equal to 3; Both the outer casing and the inner casing are open at both ends, have a circular cross section, and gradually increase from upstream to downstream, and the outer casing and the inner casing are coaxially arranged; The outer casing is uniformly provided with N installation through grooves corresponding to the cavity modules; The cavity module comprises a shell, a cavity oil injection rod, an evaporation pipe, a flow distribution plate, a first flow guide pipe, a second flow guide pipe, and a radial support plate; The shell comprises a front wall, a rear wall, an outer wall, a first side wall, and a second side wall, wherein the front wall and the rear wall are fan-shaped, the first side wall and the second side wall are symmetrical rectangles, the outer wall is an arc surface coaxial with the outer casing, the four edges of the outer wall are perpendicularly and fixedly connected with the front wall, the first side wall, the rear wall, and the second side wall, and the front wall, the first side wall, the rear wall, and the second side wall are sequentially and fixedly connected; The inner side of the shell is fixedly connected with the outer casing at the corresponding installation through groove; The front wall is provided with a first through groove for installing the evaporation pipe and a second through groove for cooperating with the first flow guide pipe, and the first through groove and the second through groove are both strip-shaped and arranged in parallel, and the second through groove is located inside the first through groove; The evaporation pipe is closed at both ends and fixedly connected with the shell through the first through groove, and both ends and the side wall of the evaporation pipe are partially located outside the shell and partially located inside the shell, and a plurality of air outlets are uniformly arranged on the side wall of the evaporation pipe inside the shell along the length direction of the evaporation pipe; The inlet of the first flow guide pipe is arranged on the inner wall of the outer casing, the outlet penetrates through the outer casing and is fixedly connected with the second through groove of the front wall of the shell, and the outlet width of the first flow guide pipe is greater than or equal to the length of the evaporation pipe; The second flow guide pipe is arranged outside the outer casing, one end of the second flow guide pipe is communicated with the first flow guide pipe, and the other end of the second flow guide pipe is communicated with the midpoint of the evaporation pipe outside the shell; The cavity oil injection rod extends into the second flow guide pipe and is used for supplying oil to the cavity module; The flow distribution plate is arranged in the evaporation pipe, fixedly connected with the inner wall of the evaporation pipe, and coplanar with the front wall, and is used for distributing the oil gas of the second flow guide pipe entering the evaporation pipe outside the shell to the part of the evaporation pipe inside the shell through both sides of the flow distribution plate; The radial support plate is a blunt body stabilizer, arranged between the outer casing and the inner casing, one end of the radial support plate is fixedly connected with the inner wall of the outer casing, the other end of the radial support plate is fixedly connected with the outer wall of the inner casing, the outer edge of the radial support plate faces the upstream, the inner edge of the radial support plate is coplanar with the inner wall of the front wall, and the radial support plate is circumferentially staggered with the second through groove; The N main flow oil injection rods are circumferentially and uniformly arranged on the outer casing upstream of the shell of the cavity module, one end of each main flow oil injection rod extends into the space between the outer casing and the inner casing, and the main flow oil injection rods are used for supplying oil to the main flow; The flow straightening module is arranged downstream of the N cavity modules and comprises a plurality of flow straightening blades; The plurality of flow straightening blades are circumferentially arranged between the outer casing and the inner casing, one end of each flow straightening blade is fixedly connected with the outer casing, the other end of each flow straightening blade is fixedly connected with the inner casing, and the flow straightening blades are used for cooperating with the radial support plates of the N cavity modules to straighten the flow.

2. The single-sided, single-inlet trapped-vortex cavity interstage combustor of claim 1, wherein, N is 5.

3. The single-sided, single-inlet trapped-vortex cavity interstage combustor of claim 1, wherein, A plurality of stabilizing blades are arranged downstream of the N cavity modules. The several stabilizing blades are arranged circumferentially between the outer casing and the inner casing, and are fixed at one end to the outer casing and at the other end to the inner casing, for reinforcing the connection between the outer casing and the inner casing and for straightening.

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