A variable geometry combustion chamber with adjustable two-stage vortex generator

Abstract

The present application belongs to the technical field of aero-engines, and particularly relates to a variable geometry combustion chamber with an adjustable two-stage vortex finder, which can automatically adjust the outlet geometric areas of the middle and outer two-stage swirlers according to the incoming flow temperature, so as to realize the automatic adjustment of the air intake amount at the flame tube head, and realize the variable air intake geometry of the combustion chamber through an adaptive air intake device, so as to ensure the ignition start and combustion stability, and control the combustion temperature in the typical working state, so as to realize low pollution emission. The air intake device mainly comprises an SMA spring with temperature-varying elastic force and a bias spring, which jointly push the cooling structure to change the outlet size of the swirler, and realizes the function of automatically adjusting the air intake geometry of the combustion chamber and adjusting the air intake amount at the head by adapting to the air intake temperature. Compared with the fixed geometry combustion chamber of staged combustion and the variable geometry combustion chamber of active adjustment, the combustion chamber has a simple structure, light weight, low cost and high reliability.

Description

Technical Field

[0001] The present application belongs to the technical field of aero-engines, and in particular relates to a variable geometry combustion chamber with an adjustable two-stage vortex finder. Background Art

[0002] As people's awareness of environmental protection and health continues to increase, people's requirements for emissions are becoming increasingly stringent. Low-emission combustion chambers have become one of the main signs of advanced technology and strong market competitiveness of aircraft engines and gas turbines. Various organizations and localities have made clear regulations on the pollution emission standards for aircraft engines and gas turbines. Among the products of combustion emissions, there are relatively strict requirements for nitrogen oxides (NOx) and carbon monoxide (CO). These two gaseous pollutants are not only toxic, but also can lead to the formation of photochemical smog and damage the earth's ozone layer. In order to achieve low-pollution combustion in the combustion chamber, the method usually adopted is to control the combustion temperature of the main combustion zone within the range of 1670K to 1900K. Within this temperature range, nitrogen oxides (NOx) and carbon monoxide (CO) are very small. The combustion temperature of the main combustion zone is mainly determined by the ratio of air and fuel in the zone. However, in addition to controlling the combustion temperature in the working state, the combustion chamber must also take into account ignition and combustion stability. In a fixed geometry combustion chamber, these two are contradictory in design. Simply reducing the combustion temperature by increasing the amount of air in the main combustion zone will cause the ignition and combustion stability of the combustion chamber to deteriorate.

[0003] In order to ensure that the combustion chamber has both low pollution emissions and good ignition and flameout performance, the staged combustion method is currently widely used, that is, the combustion zone in the combustion chamber is divided into a duty class and a main combustion class. The duty class is used to ensure ignition and combustion stability, and the main combustion class is used to control the combustion temperature to achieve low pollution emissions. Typical staged combustion methods include axial staged combustion, radial staged combustion, circumferential staged combustion, etc. These staged structures will greatly increase the complexity of the combustion chamber, and the length, volume, weight, and cooling area of ​​the combustion chamber will also increase accordingly. It is also prone to problems such as uneven temperature distribution and reduced turbine efficiency. In addition, there are some variable geometry combustion chamber solutions that actively adjust the intake area of ​​the combustion chamber through complex mechanisms, but due to the need to add an adjustment mechanism, there are problems such as high complexity, heavy weight, high cost, and low reliability of the mechanism due to the harsh working environment of high temperature and high pressure, and they have not been widely used. Summary of the invention

[0004] In order to solve the above problems, the present application provides a variable geometry combustion chamber with adjustable two-stage vortex finders, comprising:

[0005] A flame tube and an adaptive air intake device installed on the flame tube head, wherein the adaptive air intake device comprises: an inner swirler, a cooling ring, an outer swirler, an SMA spring and a bias spring;

[0006] The external cyclone is cylindrical, and has an external cyclone channel on the rear end wall of the external cyclone for introducing air outside the external wall into the wall;

[0007] The inner swirler comprises an inner swirling flow channel, the front edge of the outer wall of the inner swirling flow channel is connected to the incoming airflow surface, and an annular groove is provided on the side away from the incoming airflow surface, and the outer wall surface of the annular groove is connected to the front end of the outer swirler;

[0008] The inner wall surface of the outer swirler, the annular groove and the outer wall of the inner swirling flow channel form a narrow annular cavity for installing the SMA spring, the bias spring and the cooling ring. The front end of the cooling ring is sleeved in the narrow annular cavity. The outer wall surface of the cooling ring has a flange. One end of the SMA spring abuts against the bottom of the annular groove, and the other end abuts against the flange. One end of the bias spring abuts against the step surface of the inner wall surface of the outer swirler, and the other end abuts against the flange. The SMA spring and the bias spring respectively provide axial forces in opposite directions to the flange.

[0009] The outer wall of the cooling ring has an outer conical surface that forms an outer swirl channel outlet with the outer swirl channel, and the inner wall of the cooling ring has an inner conical surface that forms an inner swirl channel outlet with the inner swirl channel. The elastic coefficient of the SMA spring changes with temperature. When the temperature changes, the combined force of the SMA spring and the bias spring pushes the cooling ring to move axially. The axial movement of the cooling ring increases or decreases the outlet area of ​​the inner swirl channel outlet and the outlet area of ​​the outer swirl channel outlet.

[0010] Preferably, the annular groove has an air inlet for introducing air into the annular groove, the cooling ring is a ring cavity structure, the cavity opening of the cooling ring's annular cavity faces the position of the SMA spring in the annular groove, and the cavity bottom of the cooling ring's annular cavity has an exhaust hole. The air in the annular groove passes through the annular cavity of the cooling ring and is discharged through the exhaust hole, thereby reducing the temperature on the flame side of the cooling ring 2.

[0011] Preferably, the inner swirl channel of the inner swirler includes an inner ring channel and a middle ring channel, the inner ring channel has a plurality of inner ring blades distributed circumferentially, the middle ring channel has a plurality of middle ring blades distributed circumferentially, the inner ring channel and the middle ring channel are separated by a venturi tube, and the venturi tube extends behind the airflow and forms an inner swirl channel outlet with the inner cone surface for discharging the gas from the middle ring channel.

[0012] Preferably, the SMA spring has a series of multiple SMA spring adjustment pads with different thicknesses, and the bias spring has a series of multiple bias spring adjustment pads with different thicknesses.

[0013] Preferably, the inner wall surface of the outer cyclone is provided with a groove, and the groove cooperates with the anti-rotation boss of the flange to prevent the flange and the cooling ring from rotating during operation.

[0014] Preferably, the SMA spring is made of a high temperature shape memory alloy.

[0015] Preferably, the axial displacement of the cooling ring includes a first limit position formed by the abutment between the front end surface of the cooling ring and the step surface of the inner swirler, and a second limit position formed by the abutment between the flange and the step surface of the outer swirler.

[0016] Preferably, the ratio of the maximum outlet area of ​​the outer swirl channel to the minimum outlet area of ​​the outer swirl channel is 1.1 to +∞; the ratio of the maximum outlet area of ​​the inner swirl channel to the minimum outlet area of ​​the inner swirl channel is 1.1 to 3.

[0017] Preferably, the inner ring channel, the middle ring channel and the outer swirl channel all have circumferentially distributed curved blades.

[0018] Preferably, the outer wall surface of the annular groove is connected to the front end of the external cyclone through threads.

[0019] The present application mainly realizes the automatic adjustment function of the combustion chamber air intake, that is, automatically adjusts the outlet geometric area of ​​the middle and outer two-stage swirlers according to the incoming flow temperature, and realizes the automatic adjustment of the air intake amount at the flame tube head, which can ensure the ignition start-up and combustion stability, and control the combustion temperature of the typical working state to achieve low pollution emissions. The advantages of this method are as follows: 1. It realizes the function of automatically adjusting the combustion chamber air intake geometry and adjusting the head air intake amount; 2. The SMA spring can quickly exchange heat with the incoming flow temperature, and the adjustment time is short; 3. The initial elastic force of the spring can be adjusted as needed; 4. There is no complex active adjustment mechanism, the structure is simple, the weight is light, the cost is low, and the reliability is high; 5. The flow adjustment range is wider than that of the single-stage adjustable vortex generator. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a cross-sectional view of a variable geometry combustion chamber with adjustable two-stage vortex finders in a preferred embodiment of the present application;

[0021] Figure 2 is a cross-sectional view of the adaptive air intake device of the present application;

[0022] Figure 3 It is a three-dimensional diagram of the adaptive air intake device of the present application;

[0023] Figure 4 is a schematic diagram of an assembly in an embodiment of the present application;

[0024] Figure 5 This is a schematic diagram of the mode switching of the flame tube air intake device of the present application;

[0025] Figure 6 It is a cross-sectional view of the cooling ring of the present application;

[0026] Figure 7 It is a three-dimensional diagram of the cooling ring of this application;

[0027] Figure 8 It is a cross-sectional view of the flange of this application;

[0028] Fig. 9 It is a three-dimensional diagram of the flange of this application;

[0029] Fig.10 is a cross-sectional view of the external cyclone of the present application;

[0030] Fig.11 It is a stereoscopic diagram of the external cyclone of the present application;

[0031] Fig.12 is a cross-sectional view of the cyclone in the present application;

[0032] Fig.13 It is a stereoscopic diagram of the internal cyclone of the present application. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0034] like Figure 1 As shown, in order to solve the above problems, the present application provides a variable geometry combustion chamber A with adjustable two-stage vortex finders, comprising:

[0035] The flame tube and the adaptive air intake device B installed on the flame tube head, such as Figure 2 Figure 3 The adaptive air intake device B is assembled on the flame tube head through the mounting surface 4-1 on the outer swirler 4 and fixed by the pressure plate C. The outer anti-rotation boss 4-2 of the outer swirler 4 is used to prevent the adaptive air intake device B from rotating with the airflow. The fuel nozzle D is installed in the inner hole 1-2 on the inner swirler 1; the adaptive air intake device B is composed of the inner swirler 1, the cooling ring 2, the flange 3, the outer swirler 4, the SMA spring 5, the bias spring 6, the SMA spring adjustment pad 7, and the bias spring adjustment pad 8; first, the cooling ring 2, the flange 3, the outer swirler 4, the bias spring 6, and the bias spring adjustment pad 8 are mutually connected to form an assembly E through the thread 2-3 and the thread 3-1, as shown Figure 4As shown, the assembly E is connected with the inner swirler 1, the SMA spring 5, and the SMA spring adjustment pad 7 through the first thread 1-4 and the second thread 4-4 to form an adaptive air intake device B.

[0036] The outer cyclone 4 is cylindrical, such as Fig.10 Fig.11 As shown, the rear end wall surface of the external cyclone 4 is provided with an external cyclone channel for introducing the air outside the outer wall into the wall;

[0037] The inner cyclone 1 includes an inner cyclone channel, such as Fig.12 Fig.13 As shown, the front edge of the outer wall of the inner vortex channel is connected to the incoming airflow surface 1-5, and an annular groove is provided on the side away from the incoming airflow surface 1-5, and the outer wall surface of the annular groove is connected to the front end of the outer vortex device 4;

[0038] The inner wall surface of the outer cyclone 4, the annular groove and the outer wall of the inner cyclone channel form a narrow ring cavity for installing the SMA spring 5, the bias spring 6 and the cooling ring 2. The front end gap of the cooling ring 2 is sleeved in the narrow ring cavity. The outer wall surface of the cooling ring 2 has a flange 3, such as Figure 8 Fig. 9 As shown, one end of the SMA spring 5 is against the bottom of the annular groove, and the other end is against the flange 3; one end of the bias spring 6 is against the step surface of the inner wall of the outer cyclone 4, and the other end is against the flange 3; the SMA spring 5 and the bias spring 6 respectively provide axial forces in opposite directions to the flange 3; the flange 3 is pressed and fixed by the SMA spring 5 and the bias spring 6, and the flange 3 can drive the cooling ring 2 to move within a certain range along the central axis of the inner cyclone 1;

[0039] like Figure 6 Figure 7 As shown, the outer wall of the cooling ring 2 has an outer conical surface 2-4 which forms an outer swirl channel outlet with the outer swirl channel, and the inner wall of the cooling ring 2 has an inner conical surface 2-5 which forms an inner swirl channel outlet with the inner swirl channel. The elastic coefficient of the SMA spring 5 changes with temperature. When the temperature changes, the combined force of the SMA spring 5 and the bias spring 6 pushes the cooling ring 2 to move axially. The axial movement of the cooling ring 2 increases or decreases the outlet area of ​​the inner swirl channel outlet and the outlet area of ​​the outer swirl channel outlet; as shown Figure 5 As shown, an alternative is that the inner swirl channel of the inner swirler 1 includes an inner ring channel and a middle ring channel, the inner ring channel has a plurality of inner ring blades 1-6 distributed circumferentially, the middle ring channel has a plurality of middle ring blades 1-7 distributed circumferentially, the inner ring channel and the middle ring channel are separated by a venturi 1-8, the venturi 1-8 extends along the rear of the airflow and forms an inner swirl channel outlet with the inner cone 2-5 for discharging the gas from the middle ring channel;

[0040] In some optional embodiments, the annular groove has an air inlet 1-1 for introducing air into the annular groove, the cooling ring 2 is a ring cavity structure, the cavity opening of the annular cavity of the cooling ring 2 faces the position of the SMA spring 5 in the annular groove, and the cavity bottom of the annular cavity of the cooling ring 2 has an exhaust hole. The air in the annular groove passes through the annular cavity of the cooling ring 2 and is discharged through the exhaust hole. The incoming air can flow through the spring cavity where the SMA spring 5 is located through the air inlet 1-1, and the SMA spring 5 in the spring cavity can quickly exchange heat with the incoming temperature to adjust its own temperature. In addition, the air can also cool the surface of the cooling ring 2 after flowing out from the air outlet 2-2 to prevent ablation.

[0041] In some optional embodiments, the axial displacement of the cooling ring 2 includes a first limit point 1-3 formed by the abutment between its front end face and the step surface of the inner swirler 1, and a second limit point 4-3 formed by the abutment between the flange 3 and the step surface of the outer swirler 4; wherein the elastic force of the SMA spring 5 is greatly affected by its own temperature, and its characteristic is that the spring force decreases when its own temperature is lower than the phase change temperature, and the spring force increases when its own temperature is higher than the phase change temperature; the bias spring 6 is made of ordinary alloy, and the spring force is less affected by its own temperature. When the temperature of the SMA spring 5 itself is lower than the phase change temperature, the combined force of the bias spring 6 and the SMA spring 5 pushes the flange 3 and the cooling ring 2 to the left until they reach the first limit position 1-3, and the outlet areas of the middle swirler and the outer swirler switch to the small flow states Ar1 and Br1, and the air flow entering the flame tube head decreases; when the temperature of the SMA spring 5 itself is higher than the phase change temperature, the SMA spring 5 pushes the flange 3 and the cooling ring 2 to the right until they reach the second limit position 4-3, and the outlet areas of the middle swirler and the outer swirler switch to the large flow states Ar2 and Br2, and the air flow entering the flame tube head increases.

[0042] In some optional embodiments, the SMA spring 5 has a series of SMA spring adjustment pads 7 with different thicknesses, and the bias spring 6 has a series of bias spring adjustment pads 8 with different thicknesses. The initial elastic force of the SMA spring 5 and the bias spring 6 can be adjusted by replacing pads of different thicknesses.

[0043] In some optional embodiments, the inner wall surface of the outer cyclone 4 is provided with a groove 4-5, and the groove 4-5 cooperates with the anti-rotation boss 3-2 of the flange 3 to prevent the flange 3 and the cooling ring 2 from rotating during operation.

[0044] In some optional embodiments, the ratio of the maximum outlet area of ​​the outer swirl channel to the minimum outlet area of ​​the outer swirl channel is 1.1 to +∞; the ratio of the maximum outlet area of ​​the inner swirl channel to the minimum outlet area of ​​the inner swirl channel is 1.1 to 3.

[0045] In some optional embodiments, the inner ring channel, the middle ring channel and the outer swirl channel all have circumferentially distributed curved blades.

[0046] On the one hand, the inner swirler 1 is used to fix and wrap the SMA spring 5, and is connected to the second thread 4-4 on the outer swirler 4 through the first thread 1-4. Its airflow surface 1-5 is streamlined to reduce airflow loss; on the other hand, the inner ring blades 1-6 and the middle ring blades 1-7 are curved blades, which are used to rotate the airflow, thereby stabilizing combustion and assisting atomization.

[0047] In some optional embodiments, 1 to 30 adaptive air intake devices B are installed on the variable geometry combustion chamber A.

[0048] In some optional embodiments, the movement distance of the flange 3 and the cooling ring 2 on the adaptive air inlet device B along the central axis of the inner cyclone 1 is 1 to 10 mm, the outlet area ratio Ar2 / Ar1 of the middle cyclone in the large flow state and the small flow state is 1.1 to 3, and the outlet area ratio Br2 / Br1 of the outer cyclone is 1.1 to +∞.

[0049] In some optional embodiments, the number of the external anti-rotation bosses 4 - 2 on the external cyclone 4 is 1 to 5, and the number of the grooves 4 - 5 is 1 to 6.

[0050] In some optional embodiments, the number of the air inlets 1 - 1 on the inner cyclone 1 is 1 to 20, and the width of the inlets is 0.5 to 5 mm.

[0051] In some optional embodiments, the number of the annular grooves 2-1 on the cooling ring 2 is 1 to 8, the groove width is 0.5 to 5 mm, the number of the air outlet holes 2-2 is 10 to 100, and the diameter is 0.5 to 3 mm.

[0052] In some optional implementations, the number of the anti-rotation bosses 3 - 2 on the flange 3 is 1 to 6.

[0053] In some optional embodiments, the number of the outer ring blades 4 - 6 on the outer swirler 4 is 10 to 60.

[0054] In some optional embodiments, the number of the inner ring blades 1-6 and the middle ring blades 1-7 on the inner cyclone 1 is 5 to 30.

[0055] In some optional embodiments, the pitch of the threads 2-3 and 4-4 on the cooling ring 2 and the external cyclone 4 is 0.5 to 3 mm.

[0056] In some optional embodiments, the wire diameter of the SMA spring 5 and the bias spring 6 is 1 to 8 mm, and the pitch is 2 to 10 mm.

[0057] In some optional implementations, the thickness of the SMA spring adjustment pad 7 and the bias spring adjustment pad 8 is in the range of 0.1 to 5 mm.

[0058] The present application mainly realizes the automatic adjustment function of the combustion chamber air intake, that is, automatically adjusts the outlet geometric area of ​​the middle and outer two-stage swirlers according to the incoming flow temperature, and realizes the automatic adjustment of the air intake amount at the flame tube head, which can ensure the ignition start-up and combustion stability, and control the combustion temperature of the typical working state to achieve low pollution emissions. The advantages of this method are as follows: 1. It realizes the function of automatically adjusting the combustion chamber air intake geometry and adjusting the head air intake amount; 2. The SMA spring can quickly exchange heat with the incoming flow temperature, and the adjustment time is short; 3. The initial elastic force of the spring can be adjusted as needed; 4. There is no complex active adjustment mechanism, the structure is simple, the weight is light, the cost is low, and the reliability is high; 5. The flow adjustment range is wider than that of the single-stage adjustable vortex generator.

[0059] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A variable geometry combustion chamber with two-stage vortexers, characterized in that: include: A flame tube and an adaptive air intake device (B) installed at the head of the flame tube, wherein the adaptive air intake device (B) comprises: an inner swirler (1), a cooling ring (2), an outer swirler (4), an SMA spring (5) and a bias spring (6); The external cyclone (4) is cylindrical, and has an external cyclone channel on the rear end wall surface of the external cyclone (4) for introducing air outside the outer wall into the wall; The inner swirler (1) comprises an inner swirling flow channel, the front edge of the outer wall of the inner swirling flow channel is connected to the oncoming airflow surface (1-5), and an annular groove is provided on the side facing away from the oncoming airflow surface (1-5), and the outer wall surface of the annular groove is connected to the front end of the outer swirler (4); The inner wall surface of the outer swirler (4), the annular groove and the outer wall of the inner swirling channel form a narrow annular cavity for installing an SMA spring (5), a bias spring (6) and a cooling ring (2); the front end of the cooling ring (2) is sleeved in the narrow annular cavity; the outer wall surface of the cooling ring (2) has a flange (3); one end of the SMA spring (5) abuts against the bottom of the annular groove and the other end abuts against the flange (3); one end of the bias spring (6) abuts against a step surface on the inner wall surface of the outer swirler (4) and the other end abuts against the flange (3); the SMA spring (5) and the bias spring (6) respectively provide axial forces in opposite directions to the flange (3); The outer wall of the cooling ring (2) has an outer conical surface (2-4) which forms an outer swirl channel outlet with the outer swirl channel, and the inner wall of the cooling ring (2) has an inner conical surface (2-5) which forms an inner swirl channel outlet with the inner swirl channel. The elastic coefficient of the SMA spring (5) changes with temperature. When the temperature changes, the combined force of the SMA spring (5) and the bias spring (6) pushes the cooling ring (2) to move axially. The axial movement of the cooling ring (2) increases or decreases the outlet area of ​​the inner swirl channel outlet and the outlet area of ​​the outer swirl channel outlet.

2. The variable geometry combustion chamber with two-stage vortex finders as claimed in claim 1, characterized in that: The annular groove has an air inlet (1-1) for introducing air into the annular groove. The cooling ring (2) is a ring cavity structure. The cavity opening of the annular cavity of the cooling ring (2) faces the position of the SMA spring (5) in the annular groove. The cavity bottom of the annular cavity of the cooling ring (2) has an exhaust hole. The air in the annular groove passes through the annular cavity of the cooling ring (2) and is discharged through the exhaust hole, thereby reducing the temperature of the flame side of the cooling ring (2).

3. The variable geometry combustion chamber with two-stage vortex finders as claimed in claim 1, characterized in that: The inner swirl channel of the inner swirler (1) comprises an inner ring channel and a middle ring channel, the inner ring channel having a plurality of inner ring blades (1-6) distributed circumferentially, the middle ring channel having a plurality of middle ring blades (1-7) distributed circumferentially, the inner ring channel and the middle ring channel being separated by a venturi tube (1-8), the venturi tube (1-8) extending behind the airflow and forming an inner swirl channel outlet with an inner conical surface (2-5) for discharging gas from the middle ring channel.

4. The variable geometry combustion chamber with two-stage vortex finders as claimed in claim 1, characterized in that: The SMA spring (5) has a series of multiple SMA spring adjustment pads (7) with different thicknesses, and the bias spring (6) has a series of multiple bias spring adjustment pads (8) with different thicknesses.

5. The variable geometry combustion chamber with two-stage vortex finders as claimed in claim 1, characterized in that: The inner wall surface of the outer cyclone (4) is provided with a groove (4-5), and the groove (4-5) cooperates with the anti-rotation boss (3-2) of the flange (3) to prevent the flange (3) and the cooling ring (2) from rotating during operation.

6. The variable geometry combustion chamber with two-stage vortex finders as claimed in claim 1, characterized in that: The SMA spring (5) is manufactured from a high temperature shape memory alloy.

7. The variable geometry combustion chamber with two-stage vortex finders as claimed in claim 1, characterized in that: The axial displacement of the cooling ring (2) includes a first limit position (1-3) formed by the abutment between its front end surface and the step surface of the inner swirler (1), and a second limit position (4-3) formed by the abutment between the flange (3) and the step surface of the outer swirler (4).

8. The variable geometry combustion chamber with two-stage vortex finders as claimed in claim 1, characterized in that: The ratio of the maximum outlet area of ​​the outer swirl channel to the minimum outlet area of ​​the outer swirl channel is 1.1 to +∞; the ratio of the maximum outlet area of ​​the inner swirl channel to the minimum outlet area of ​​the inner swirl channel is 1.1 to 3.

9. The variable geometry combustion chamber with two-stage vortex finders as claimed in claim 3, characterized in that: The inner ring channel, the middle ring channel and the outer vortex flow channel are all provided with circumferentially distributed curved blades.

10. The variable geometry combustion chamber with two-stage vortex finders as claimed in claim 1, characterized in that: The outer wall surface of the annular groove is connected to the front end of the external cyclone (4) via threads.

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