A variable sliding arc plasma center staged combustion chamber head

Abstract

The present invention discloses a variable sliding arc plasma center-graded combustion chamber head, which relates to the field of aero-engine combustion chamber structure. The first-stage swirler and the second-stage swirler are both removable and replaceable, which can reduce the repeated processing of test pieces. The function of single duty class discharge and simultaneous discharge of main combustion class and duty class can be realized, and it has the advantages of simple structure, high reliability and low consumption. The combustion chamber head includes a first-stage swirler, a second-stage swirler and a third-stage swirler from the inside to the outside, and a duty class nozzle is fixedly connected to the center of the first-stage swirler, and a venturi is provided between the first-stage swirler and the second-stage swirler; a main combustion stage nozzle is provided between the second-stage swirler and the third-stage swirler. The present invention can perform parametric research by installing swirlers of different angles and different rotation directions, avoiding various defects caused by the integrated processing of multiple sets of swirler model test pieces, and can greatly shorten the processing cycle and save economic costs.

Description

Technical Field

[0001] The invention relates to the field of aero-engine combustion chamber structures, in particular to a variable sliding arc plasma central staged combustion chamber head. Background Art

[0002] As the combustion chamber continues to develop towards high temperature rise and high heat capacity, the design requirements for the combustion chamber are also constantly increasing, such as better ignition and flameout performance, higher combustion efficiency, and lower pollutant emissions. The solution to the above is usually to improve the fuel nozzle, design a more complex combustion chamber head, and adopt new combustion technology. However, the improvement effect is often limited. At the same time, advanced combustion chambers face the technical challenge of achieving a higher outlet temperature distribution with very little mixed gas volume. The application of non-equilibrium plasma ignition and combustion technology can overcome the above difficulties. Plasma is the fourth state of matter in nature after gas, liquid and solid. Its existence provides a new solution for the ignition, combustion control and pollutant emission control of the combustion chamber.

[0003] In response to the above requirements, technicians in this field have conducted a lot of research, such as the patent "A DBD plasma blade axial swirler for the combustion chamber head of an aircraft engine", patent number CN113669757B, which includes an inner ring grounding electrode, an outer ring high-voltage electrode, a swirler main body, and a wire; a high concentration of active particles is generated at the airflow channel position of the swirler blades, thereby achieving the purpose of strengthening combustion in the combustion chamber, expanding the flameout boundary, and improving combustion efficiency. The patent "A rotating sliding arc plasma enhanced combustion swirling device", patent number CN115597058A, includes a fuel nozzle, an insulating sleeve, and a swirler, which simplifies the structure of the combustion chamber swirler based on plasma excitation and enhances the strength of the swirler. Patent CN115218222A "A burner and method for suppressing combustion oscillation by rotating sliding arc discharge plasma", patent number CN115218222A, drives the arc through the arc channel between the anode shell and the cathode truncated cone electrode through the swirl airflow to form a three-dimensional rotating sliding arc, and forms a three-dimensional space discharge plasma area, which regulates and suppresses the combustion oscillation state of the flame. Patent "A sliding arc plasma duty flame head in the combustion chamber of an aircraft engine", patent number, CN113898974B, its fuel nozzle is located in the cathode sleeve, and the anode venturi is sleeved on the first-stage swirler. Through the sliding arc, the service life of the aircraft engine turbine is improved. Patent "A three-dimensional rotating sliding arc plasma exciter with single and double paths", patent number CN113153539A, adopts two layers of inner and outer swirlers, two sets of inner and outer electrodes, can generate plasma arcs at the same time, broaden the ignition boundary of the combustion chamber of the aircraft engine, and improve combustion efficiency.

[0004] However, the above plasma cyclone structure is relatively simple and is only used for duty class combustion. There are duty class and main combustion stage in the head of advanced combustion chamber, and there is still not much mention of plasma enhanced combustion of main combustion stage. At the same time, the current plasma cyclone is an integrated structure and cannot be adjusted. For different plasma cyclone schemes, traditional combustion chamber test pieces need to undergo a large number of repetitive tests to change the structural parameters, which increases the research cost and resources to a certain extent. Summary of the invention

[0005] In view of the above problems, the present invention proposes a variable sliding arc plasma center-graded combustion chamber head, wherein both the first-stage cyclone and the second-stage cyclone are removable and replaceable, which can reduce the repeated processing of the test piece. The duty class adopts the sliding arc plasma combustion-supporting method, and the main combustion stage adopts the sliding arc plasma combustion-supporting method. The functions of the duty class discharge alone and the main combustion stage and the duty class discharge simultaneously can be realized, and the advantages of simple structure, high reliability and low consumption are combined.

[0006] The technical solution of the present invention is as follows: the combustion chamber head includes a primary swirler 1, a secondary swirler 2 and a tertiary swirler 3 from the inside to the outside, a primary swirler nozzle 4 is fixedly connected to the center of the primary swirler 1, a venturi 6 is provided between the primary swirler 1 and the secondary swirler 2; a main combustion nozzle 5 is provided between the secondary swirler 2 and the tertiary swirler 3;

[0007] The primary cyclone 1 is detachably connected to the inner wall of the venturi 6, and the secondary cyclone 2 is detachably connected to the outer wall of the venturi 6. A sleeve 15 detachably connected to the venturi 6 is also provided at the front end of the venturi 6. The outer wall of the secondary cyclone 2 is threadedly connected to the inner wall of the tertiary cyclone 3, and the main combustion stage nozzle 5 penetrates the tertiary cyclone 3. In this way, the primary cyclone 1 and the secondary cyclone 2 can be detachable, and the primary cyclone 1 and the secondary cyclone 2 of different shapes and structures can be installed according to the research content.

[0008] The first-stage cyclone 1 and the second-stage cyclone 2 are both made of insulating materials, and the sleeve 15 is made of insulating materials or conductive materials. The sleeve 15 structure can be made of metal materials and ceramic materials to adjust the plasma discharge mode. By replacing the sleeve, it is possible to perform the on-duty plasma combustion alone and the on-duty plasma combustion and the main combustion plasma combustion at the same time. Specifically:

[0009] When the sleeve 15 is made of ceramic material, the venturi tube 6 is insulated from the main combustion stage nozzle 5, and the duty class nozzle 4 discharges with the venturi tube 6 to form a duty class plasma combustion support alone;

[0010] When the sleeve 15 is made of metal, the venturi 6 discharges with the main combustion stage nozzle 5, and the duty class nozzle 4 discharges with the venturi 6, and the duty class plasma combustion and the main combustion stage plasma combustion are formed simultaneously.

[0011] The primary cyclone 1 and the secondary cyclone 2 are made of ceramic material, and the venturi 6 is made of metal material, which effectively isolates the metal from conducting electricity and realizes the function of sliding arc plasma discharge.

[0012] Regarding the detachable connection between the primary cyclone 1 and the venturi 6:

[0013] The front part of the inner wall of the venturi tube 6 has an annular limiting protrusion, and the rear part of the venturi tube 6 has a lead terminal 8;

[0014] The front part of the primary cyclone 1 abuts against the limiting protrusion, and the rear part abuts against the ceramic mounting edge 9, the ceramic mounting edge 9 includes a ring-shaped mounting edge body and a lead receiving tube, the lead receiving tube is sleeved on the lead terminal 8, and the mounting edge body is attached to the end surface of the rear part of the venturi tube 6;

[0015] The rear end of the lead terminal 8 is provided with a through hole, and the rear end of the lead terminal 8 is provided with a lead interface 10, the lead interface 10 is sleeved on the rear end of the lead terminal 8, and fits on the end surface of the rear part of the lead accommodating tube, and a bolt 11 is provided in the lead interface 10 to penetrate the through hole, and the lead interface 10, the ceramic mounting edge 9, the primary cyclone 1 and the venturi 6 are axially locked by the bolt 11. In this way, during assembly, the primary cyclone 1 can be placed in the venturi 6 first, and then the ceramic mounting edge 9 and the lead interface 10 can be sequentially sleeved along the lead terminal 8, so that the primary cyclone 1 is pressed between the limiting protrusion and the ceramic mounting edge 9, and finally the bolt 11 is inserted to achieve the axial locking of the primary cyclone 1.

[0016] Regarding the detachable connection between the secondary cyclone 2 and the venturi 6:

[0017] The outer diameter of the mounting edge body of the ceramic mounting edge 9 is larger than the outer diameter of the venturi tube 6. The sleeve 15 is sleeved on the front part of the venturi tube 6 and fits with the secondary cyclone 2, so that the secondary cyclone 2 is locked between the sleeve 15 and the ceramic mounting edge 9.

[0018] A plurality of steps 7 are fixedly connected to the front of the outer wall of the venturi tube 6, and a plurality of snap-in grooves corresponding to the steps 7 are provided at the rear of the sleeve 15, and the snap-in grooves include an introduction groove arranged parallel to the axial direction of the sleeve 15 and a snap-in groove arranged circumferentially of the sleeve 15, the introduction groove and the snap-in groove are kept in communication, and the snap-in groove is adapted to the step 7. In this way, during assembly, the ceramic mounting edge 9 and the venturi tube 6 can be fixed first, and then the secondary cyclone 2 can be installed from front to back, and finally the sleeve 15 can be installed, and the sleeve can be rotated so that the step 7 passes through the introduction groove and enters the snap-in groove, completing the axial locking of the sleeve 15 and the secondary cyclone 2.

[0019] The beneficial effects of the present invention are:

[0020] The present invention includes a primary cyclone and a secondary cyclone, and the primary cyclone and the secondary cyclone are designed to be detachable, and other structures remain unchanged, so that parametric research can be carried out by installing cyclones of different angles and different rotation directions, avoiding various defects caused by the integrated processing of multiple sets of cyclone model test pieces, which can greatly shorten the processing cycle and save economic costs. In addition, the primary cyclone and the secondary cyclone of the present invention are made of ceramic materials, which effectively isolate the metal from conducting electricity and realize the function of sliding arc plasma discharge. At the same time, the working mode of the sliding arc can be changed by using the sleeve structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of plasma discharge.

[0022] Figure 2 This is the structural diagram of this case.

[0023] Figure 3 yes Figure 2 A cross-sectional view of

[0024] Figure 4 This is a schematic diagram of a Venturi tube.

[0025] Figure 5 This is a schematic diagram of the ceramic installation edge.

[0026] Figure 6 This is a schematic diagram of the lead interface.

[0027] Figure 7 This is a schematic diagram of the metal installation edge.

[0028] Figure 8 This is a schematic diagram of the secondary and tertiary cyclones.

[0029] Fig. 9 It is a schematic diagram of the sleeve;

[0030] In the figure, 1 is a first-stage cyclone, 2 is a second-stage cyclone, 3 is a third-stage cyclone, 4 is a duty-stage nozzle, 5 is a main combustion-stage nozzle, 6 is a venturi tube, 7 is a step, 8 is a lead terminal, 9 is a ceramic mounting edge, 10 is a lead interface, 11 is a bolt, 12 is a metal mounting edge, 13 is an external thread, 14 is an internal thread, 15 is a sleeve, and 16 is a slot. Implementation

[0031] In order to clearly illustrate the technical features of this patent, this patent is elaborated in detail below through a specific implementation method and in combination with its accompanying drawings.

[0032] like Figure 1 As shown, sliding arc discharge is a typical form of plasma discharge. In the cyclone, the rotating airflow increases the residence time of the gas in the rotating sliding arc exciter. The plasma active particles generated by the circumferentially distributed rotating sliding arc are evenly distributed, allowing all dielectric gases to fully interact with the plasma.

[0033] According to the principle of three-dimensional sliding arc combustion assistance, a cyclone plasma scheme is designed, which mainly consists of a first-stage cyclone 1, a second-stage cyclone 2, a third-stage cyclone 3, a duty-stage nozzle 4, a main combustion-stage nozzle 5, a sleeve 15, a metal mounting edge 12, a ceramic mounting edge 9, and a venturi 6. This is the basic structure of the head of the sliding arc plasma central graded combustion chamber.

[0034] Since the plasma combustion-supporting process requires the aid of an external power source for the discharge process, certain insulating materials are required, and its combustion method is still in the form of graded combustion of the duty class and the main combustion stage. Specific implementation method: The duty class nozzle 4 is made of metal material, as the negative electrode, fixed on the first-stage cyclone 1, the venturi 6 is the positive electrode, and the first-stage cyclone 1 is made of ceramic material, the venturi 6 is insulated from the nozzle 4, forming positive and negative two levels, and discharges between the nozzle 4 and the venturi 6 to form a sliding arc to strengthen combustion. This part is the duty class combustion-supporting combustion. The second-stage cyclone 2 is also made of ceramic material, and the venturi 6 is insulated from the third-stage cyclone 3. The second-stage cyclone 2 is positioned axially by the mounting edge 12. The main combustion stage nozzle 5 is the negative electrode, forming two levels with the venturi 6, and discharges between the main combustion stage nozzle 5 and the sleeve 15 to form a sliding arc to strengthen combustion. This part is the main combustion stage combustion-supporting combustion.

[0035] The structure of this case is as follows:

[0036] The primary cyclone 1 is fixed by the venturi 6 and the ceramic mounting edge 9, and the primary cyclone 1 is placed in the venturi 6. The venturi 6 is provided with a step 7 structure, which is used to cooperate with the slot 16 on the sleeve 15 structure for fixing, and the secondary cyclone 2 is placed, and then the ceramic mounting edge 9 is inserted to perform axial positioning of the primary cyclone 1 and the secondary cyclone 2. The tertiary cyclone 3 and the main combustion stage nozzle 5 are an integral structure, and are connected to the internal thread 14 on the tertiary cyclone 3 through the external thread 13 on the metal mounting edge 12. The sleeve 15 can be designed as a ceramic material and a metal material. When the sleeve 15 is a ceramic material, the venturi 6 is insulated from the secondary cyclone 2, the tertiary cyclone 3 and the main combustion stage nozzle 5, and only the duty class plasma discharge combustion-supporting exists at this time. When the sleeve 15 is a metal material, there is plasma discharge combustion-supporting between the venturi 6 and the main combustion stage nozzle 5, and the duty class and the main combustion stage plasma discharge combustion-supporting are carried out simultaneously. Therefore, the combustion-supporting form can be adjusted. The venturi tube 6 is used as the positive electrode, connected to the lead terminal 8, and connected to the external power supply through the lead interface 10 and the bolt 11 to form a positive electrode. At the same time, the primary cyclone 1 and the secondary cyclone 2 are both replaceable, and different structural schemes can be studied. Through plasma combustion, the atoms and molecules in the reactants are excited to produce a large number of active components, which will directly regulate the chemical reaction rate. On the other hand, plasma combustion can increase the mixing degree between the fuel and the fresh air, which undoubtedly provides a new idea for optimizing the performance of the combustion chamber.

[0037] There are many specific implementation ways of the present invention. The above is only the preferred implementation mode of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A variable sliding arc plasma center staged combustion chamber head, characterized in that: The combustion chamber head comprises, from the inside to the outside, a primary swirler (1), a secondary swirler (2) and a tertiary swirler (3); the venturi (6) is made of metal material; a combustion stage nozzle (4) is fixedly connected to the center of the primary swirler (1); a venturi (6) is provided between the primary swirler (1) and the secondary swirler (2); and a main combustion stage nozzle (5) is provided between the secondary swirler (2) and the tertiary swirler (3); The first-stage cyclone (1) is detachably connected to the inner wall of the venturi tube (6), the second-stage cyclone (2) is detachably connected to the outer wall of the venturi tube (6), a sleeve (15) detachably connected to the venturi tube (6) is provided at the front end of the venturi tube (6), the outer wall of the second-stage cyclone (2) is threadedly connected to the inner wall of the third-stage cyclone (3), and the main combustion stage nozzle (5) penetrates the inner wall of the third-stage cyclone (3); The primary cyclone (1) and the secondary cyclone (2) are both made of insulating material, and the sleeve (15) is made of insulating material or conductive material; When the sleeve (15) is made of ceramic material, the venturi tube (6) is insulated from the main combustion stage nozzle (5), and the duty stage nozzle (4) and the venturi tube (6) discharge to form a duty stage plasma for combustion support alone; When the sleeve (15) is made of metal material, the venturi (6) discharges with the main combustion stage nozzle (5), and the duty stage nozzle (4) discharges with the venturi (6), thereby forming duty stage plasma combustion-supporting and main combustion stage plasma combustion-supporting.

2. A variable sliding arc plasma central staged combustion chamber head according to claim 1, characterized in that: The first-stage cyclone (1) and the second-stage cyclone (2) are made of ceramic material, and the venturi (6) is made of metal material.

3. A variable sliding arc plasma central staged combustion chamber head according to claim 1, characterized in that: The front portion of the inner wall of the venturi tube (6) has an annular limiting protrusion, and the rear portion of the venturi tube (6) has a lead terminal (8); The front part of the primary cyclone (1) abuts against the limiting protrusion, and the rear part abuts against the ceramic mounting edge (9), the ceramic mounting edge (9) comprising an annular mounting edge body and a lead receiving tube, the lead receiving tube is sleeved on the lead terminal (8), and the mounting edge body is attached to the end surface of the rear part of the Venturi tube (6); A through hole is provided at the rear end of the lead terminal (8), and a lead interface (10) is provided at the rear end of the lead terminal (8). The lead interface (10) is sleeved on the rear end of the lead terminal (8) and fits onto the end surface of the rear portion of the lead receiving tube. A bolt (11) is provided in the lead interface (10) and passes through the through hole. The bolt (11) is used to axially lock the lead interface (10), the ceramic mounting edge (9), the primary cyclone (1) and the venturi tube (6).

4. A variable sliding arc plasma central staged combustion chamber head according to claim 3, characterized in that: The outer diameter of the mounting edge body of the ceramic mounting edge (9) is greater than the outer diameter of the venturi tube (6); the sleeve (15) is sleeved on the front part of the venturi tube (6) and fits with the secondary cyclone (2), so that the secondary cyclone (2) is locked between the sleeve (15) and the ceramic mounting edge (9); A plurality of steps (7) are fixedly connected to the front portion of the outer wall of the venturi tube (6), and a plurality of clamping grooves corresponding to the steps (7) are provided at the rear portion of the sleeve (15). The clamping grooves include an introduction groove arranged parallel to the axial direction of the sleeve (15) and a clamping groove arranged along the circumference of the sleeve (15). The introduction groove and the clamping groove are connected, and the clamping groove is adapted to the steps (7).

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