Combined rotary detonation combustion chamber and control method thereof

Abstract

The application provides a combined rotary detonation combustion chamber and a control method thereof, which can overcome the problems of low efficiency, high emission and large pressure drop of a traditional combustion chamber, so that a gas turbine has the characteristics of low pollution, high efficiency and compact structure under high load working conditions, and the traditional combustion chamber can effectively prevent the operation failure of the gas turbine caused by unsuccessful detonation or flameout, the cooling design is considered, a unified cooling system can be shared by the inner wall of the annular combustion chamber and the wall surface of the cylindrical combustion chamber, and the complexity of the cooling design and the processing cost are reduced.In addition, when the gas turbine is in the transition stage of switching between the annular combustion chamber and the cylindrical combustion chamber, the higher fuel air ratio of the detonation combustion is preferentially ensured.The combustion chamber of the application can combine the advantages of rotary detonation combustion and traditional constant pressure combustion, and realize high efficiency while ensuring stability.

Description

Technical Field

[0001] This invention relates to the field of gas turbine technology, and in particular to a combined rotating detonation combustor for gas turbines and its control method. Background Technology

[0002] The most common combustion mode in nature is slow combustion, where flame propagation depends on the diffusion of mass and heat, typically at speeds of several to tens of meters per second. Currently, almost all gas turbines employ isobaric combustion, a method known for its high stability and technological maturity. Detonation, on the other hand, is a combustion mode characterized by strong coupling between shock waves and chemical reactions, propagating at supersonic speeds on the order of km / s. Compared to isobaric combustion heat engines, it boasts higher cycle thermal efficiency, thus improving fuel economy. Rotating detonation gas turbines typically employ an annular combustion chamber with continuous fuel and oxidizer injection. One or more detonation waveheads propagate circumferentially within the combustion chamber, and the high-temperature, high-pressure products following the detonation wave rapidly expand and are expelled at high speed from the turbine's exhaust, generating continuous power output. Compared to pulse detonation, rotating detonation gas turbines require only a single ignition to form a stable, continuous rotating detonation wave, resulting in less vibration and noise. In summary, rotating detonation gas turbines offer advantages such as high thermal cycle efficiency, rapid heat release rate, high thermal density, and compact structure. However, they are prone to detonation failure at low fuel-air equivalence ratios, exhibiting stability issues.

[0003] Therefore, combining the advantages of traditional isobaric combustion with rotating detonation combustion has become a key research direction for technical personnel. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a combined rotating detonation combustor that can be used in gas turbines. It utilizes the advantages of rotating detonation combustion and conventional combustion to solve problems such as the difficulty of initiation in rotating detonation combustors and the large entropy increase in conventional combustors.

[0005] To achieve the above and other related objectives, the present invention provides a combined rotating detonation combustion chamber, comprising:

[0006] A cylindrical combustion chamber, wherein the cylindrical combustion chamber is used for isobaric combustion;

[0007] An annular combustion chamber surrounds the outer perimeter of the cylindrical combustion chamber and is used for rotary detonation combustion;

[0008] An intake assembly, located at the front end of the combustion chamber, is used to provide oxidant to the cylindrical combustion chamber and the annular combustion chamber.

[0009] Preferably, the intake assembly includes an inlet, a cylindrical connecting part, and a conical connecting part. The cylindrical connecting part and the conical connecting part are coaxially arranged and communicate with the inlet. The rear ends of the cylindrical connecting part and the conical connecting part are respectively connected to the cylindrical combustion chamber and the annular combustion chamber. The inlet is connected to a compressor to provide compressed air or compressed oxygen as an oxidant.

[0010] Preferably, the front end of the cylindrical combustion chamber is connected to a slow-burning nozzle for supplying fuel to the cylindrical combustion chamber, and the slow-burning nozzle is coaxially disposed on the inner side of the inlet; the slow-burning nozzle includes one of a single-hole nozzle, a multi-hole nozzle, a premixed nozzle, and a combined multi-stage nozzle.

[0011] Preferably, a cyclone separator is provided on the inner wall of the cylindrical connecting part near the rear end of the cylindrical combustion chamber, so that the oxidant passes through the cyclone separator to form an airflow with a certain swirl angle and form a main recirculation zone, thereby forming the main combustion zone; the rear end side wall of the cylindrical combustion chamber has several mixing holes, and the fuel undergoes a chemical reaction in the main combustion zone to form high-temperature flue gas. After mixing with the cold air in the mixing holes, it reaches the turbine inlet temperature requirement of the gas turbine and is discharged from the first outlet connected to the rear end of the cylindrical combustion chamber, thereby generating output power.

[0012] Preferably, the first conical connecting part is connected to the annular combustion chamber through an inlet contraction section and a first throat section. The first throat section is provided with a detonation nozzle in the radial direction. The detonation nozzle is used to provide fuel to the annular combustion chamber. The detonation nozzle includes one of a direct injection ring, an annular array orifice, and a swirl atomizer.

[0013] Preferably, it also includes a pre-detonation tube tangentially installed on the outer wall of the annular combustion chamber.

[0014] Preferably, the rear end of the annular combustion chamber is sequentially connected to an outlet contraction section and a second throat section, wherein the outlet contraction section is used to control the ambient pressure inside the annular combustion chamber.

[0015] Preferably, the outer wall of the cylindrical combustion chamber is provided with a cooling channel.

[0016] Preferably, each of the cylindrical combustion chamber and the annular combustion chamber is equipped with a set of intake control valves to control the opening degree of the oxidant.

[0017] The present invention also provides a control method for the combined rotating detonation combustion chamber, comprising the following steps:

[0018] S1: During the gas turbine start-up phase, the starter motor drives the compressor to reach the ignition speed. Before the ignition speed, the intake control valve of the annular combustion chamber is closed, so that all the oxidant at the compressor outlet enters the cylindrical combustion chamber to participate in the traditional slow combustion process.

[0019] S2: After successful ignition, gradually increase the fuel quantity and increase the turbine speed; until 100% speed is reached, the condition of minimum fuel quantity and maximum air quantity is reached; gradually increase the load until 30% of the rated load is reached, and prepare to open the intake control valve of the annular combustion chamber. At this time, control the intake control valve of the annular combustion chamber at the pre-adjusted set opening, and at the same time adjust the intake control valve of the cylindrical combustion chamber to ensure that there is no flameout or high fuel-air ratio.

[0020] S3: Open the fuel passage of the annular combustion chamber and the intake control valve of the annular combustion chamber. Then, start the pre-detonation tube for ignition. At this time, the total fuel flow can theoretically bring the gas turbine to about 80% of its rated load. Maintain this condition for a period of time. After ensuring that there are no abnormalities in the various indicators of the gas turbine, gradually close the fuel passage and intake control valve in the cylindrical combustion chamber, so that all the fuel enters from the annular combustion chamber and all the air enters the annular combustion chamber and the cooling passage. Observe the various dynamic indicators. After ensuring that all static and dynamic indicators are normal, gradually increase the gas turbine load until it reaches 100% load.

[0021] S4: During the gas turbine shutdown phase, the gas turbine load is gradually reduced to 80%. At this time, the intake control valve of the cylindrical combustion chamber is opened, and the fuel flow in the annular combustion chamber is gradually reduced to the theoretical flow rate of 50% load. The fuel flow in the cylindrical combustion chamber is gradually increased to keep the gas turbine at around 80% load. The fuel flow in the annular combustion chamber is further reduced until the combustion chamber is shut off, and then the fuel passage and intake valve of the annular combustion chamber are closed. At this time, the operation of the cylindrical combustion chamber puts the gas turbine at 30% load. The load of the cylindrical combustion chamber is gradually reduced until it is no load. The fuel quantity is gradually reduced, and the turbine speed is gradually reduced. After reaching below 30% speed, all fuel passages are closed. Finally, the gas turbine is turned over to purge residual fuel and cool all components to near room temperature.

[0022] As described above, this invention provides a combined rotating detonation combustor and its control method. This combined rotating detonation combustor overcomes the problems of low efficiency, high emissions, and large pressure drop of traditional combustors, enabling gas turbines to exhibit low pollution, high efficiency, and compact structure under high load conditions. Traditional combustors effectively prevent gas turbine failure due to unsuccessful initiation or flameout. This invention also considers cooling design; the inner wall of the annular combustor and the wall of the cylindrical combustor can share a unified cooling system, reducing the complexity of cooling design and manufacturing costs. Furthermore, when the gas turbine is in the transition phase between these two methods, a higher fuel-air ratio for detonation combustion is prioritized. The combustor of this invention combines the advantages of rotating detonation combustion and traditional isobaric combustion, achieving high efficiency while ensuring stability. Attached Figure Description

[0023] Figure 1The diagram shown is a cross-sectional view of the combustion chamber of this invention.

[0024] Component designation explanation

[0025] 1. Slow-burning nozzle

[0026] 2. Hydrocyclone

[0027] 3. Air film cooling holes

[0028] 4. Mixing pores

[0029] 5. Cylindrical Combustion Chamber

[0030] 6 Second Export Section

[0031] 7. Pre-explosion tube

[0032] 8 Detonation Nozzle

[0033] 9. Annular Combustion Chamber

[0034] 10. Annular combustion chamber exterior wall

[0035] 11 Import Department

[0036] 12. Tapered connecting part

[0037] 13. Columnar connection part

[0038] 51 First Export Department

[0039] 91 Imported contraction segment

[0040] 92 First laryngeal segment

[0041] 61 Export contraction section

[0042] 62 Second larynx segment Detailed Implementation

[0043] The following specific examples illustrate the implementation 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 embodiments, and 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.

[0044] In the detailed description of embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged and not to scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0045] For ease of description, spatial relation terms such as “below,” “under,” “lower than,” “below,” “above,” and “upper” may be used herein to describe the relationship between one element or feature shown in the accompanying drawings and other elements or features. It will be understood that these spatial relation terms are intended to include directions other than those depicted in the drawings for the device in use or operation. Furthermore, when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or there may be one or more layers in between. The phrase “between” as used herein includes both endpoint values.

[0046] In the context of this application, the structure described above the first feature may include embodiments in which the first and second features are formed in direct contact, or embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0047] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0048] Example 1

[0049] like Figure 1 As shown, this embodiment provides a combined rotary detonation combustion chamber, specifically including:

[0050] A cylindrical combustion chamber 5 is used for isobaric combustion;

[0051] An annular combustion chamber 9 surrounds the cylindrical combustion chamber 5 and is used for rotary detonation combustion;

[0052] An intake assembly, located at the front end of the combustion chamber, is used to provide oxidant to the cylindrical combustion chamber 5 and the annular combustion chamber 9; the oxidant may be oxygen, air, etc.

[0053] Furthermore, the intake assembly includes an inlet 11, a cylindrical connecting portion 13, and a conical connecting portion 12. The cylindrical connecting portion 13 and the conical connecting portion 12 are coaxially arranged and communicate with the inlet 11. The rear ends of the cylindrical connecting portion 13 and the conical connecting portion 12 are respectively connected to the cylindrical combustion chamber 5 and the annular combustion chamber 9. The inlet 11 is connected to a compressor to provide compressed air or compressed oxygen as an oxidant.

[0054] The front end of the cylindrical combustion chamber 5 is connected to a slow-burning nozzle 1, which is used to supply fuel to the cylindrical combustion chamber 5. The slow-burning nozzle 1 is coaxially arranged inside the inlet portion 11. The slow-burning nozzle 1 can be a single-hole nozzle, a multi-hole nozzle, a premixed nozzle, a combined multi-stage nozzle, etc.

[0055] Furthermore, a swirler 2 is provided on the inner wall of the cylindrical connecting part 13 near the rear end of the cylindrical combustion chamber 5, so that the oxidant passes through the swirler 2 to form an airflow with a certain swirling angle and form a main recirculation zone, thereby forming the main combustion zone. Several mixing holes 4 are opened on the rear side wall of the cylindrical combustion chamber 5. The fuel undergoes a chemical reaction in the main combustion zone to form high-temperature flue gas, which mixes with the cold air in the mixing holes 4 to reach the turbine inlet temperature requirement of the gas turbine and is discharged from the first outlet 51 connected to the rear end of the cylindrical combustion chamber 5, thereby generating output power.

[0056] Furthermore, the outer wall of the cylindrical combustion chamber 5 is provided with a cooling channel, which is a film cooling hole 3. The basic principle of film cooling is to draw a portion of high-pressure cold air from the compressor, transport it to the film cooling hole 3 and spray it out, forming a thin film of cold air on the wall surface, thereby achieving a cooling effect. The cooling channel provided here is located between the outer wall of the cylindrical combustion chamber 5 and the inner wall of the annular combustion chamber 9, which can cool both combustion chambers.

[0057] Furthermore, the first conical connecting part 12 is connected to the annular combustion chamber 9 via an inlet contraction section 91 and a first throat section 92, with a detonation nozzle 8 arranged radially in the first throat section 92. Its working principle is that after the oxidant is throttled from the inlet contraction section 91, a high-speed airflow is formed in the first throat section 92, causing the liquid fuel in the detonation nozzle 8 to be fully broken up, evaporated, and mixed, and also ensuring the gaseous fuel is fully mixed. The detonation is initiated by the tangentially installed pre-detonation tube 7, forming a detonation wave propagating circumferentially. The combustible reactants undergo a rapid chemical reaction under the compression of the leading shock wave, and the energy released by the fuel can support the continuous propagation of the leading shock wave.

[0058] The annular combustion chamber 9 is sequentially connected to an outlet contraction section 61 and a second throat section 62 at its rear end. The outlet contraction section 61 is mainly used to control the ambient pressure inside the annular combustion chamber 9. A second outlet section 6 is connected to the rear end of the second throat section 62, and the second outlet section 6 is coaxially arranged around the first outlet section 51. Both the first outlet section 51 and the second outlet section 6 are conical and contracted. The rear end of the first outlet section 51 is in contact with the rear end of the second outlet section 6, that is, the outer wall of the rear end of the first outlet section 51 and the inner wall of the rear end of the second outlet section 6 share a common wall surface.

[0059] Furthermore, the pre-detonation tube 7 comprises a spark plug, a pre-detonation tube swirler, a fuel injection orifice, an air injection orifice, and a pressure sensor. The pre-detonation tube swirler thoroughly mixes the fuel in the fuel injection orifice with the air in the air injection orifice, allowing for electric ignition by the spark plug, and can select appropriate ignition energy according to different fuel types. The pressure sensor provides feedback on the pressure in the pre-detonation tube 7, providing ignition feedback. When the peak pressure in the pre-detonation tube 7 reaches the theoretical value of the detonation wave CJ, detonation waves with different propagation modes are formed.

[0060] Specifically, during detonation combustion, the fuel-air mixture in the pre-detonation tube 7 is first ignited. After the slow combustion to detonation transition is completed in the pre-detonation tube 7, the combustible mixture is tangentially introduced into the main detonation path of the annular combustion chamber 9, typically generating one or more circumferentially propagating detonation waves in the combustion chamber. During the propagation of the detonation waves, the combustible mixture formed by fuel and oxidizer is continuously introduced into the combustion chamber from the head. Unburned propellant formed in front of the detonation wave is supplied for combustion by the detonation wave. The high-temperature, high-pressure detonation products expand primarily along the axial direction of the combustion chamber and are ultimately accelerated out to generate thrust.

[0061] Furthermore, the detonation nozzle 8 can be a direct injection ring, an annular array of orifices (for gaseous fuel), or a swirling atomizer, which can provide better atomization. The opening of the detonation nozzle 8 and the slow-burning nozzle 1 can be controlled by the same fuel control unit to flexibly distribute the fuel entering the cylindrical combustion chamber 5 and the annular combustion chamber 9.

[0062] Furthermore, the oxidizer supply to the cylindrical combustion chamber 5 and the annular combustion chamber 9 can be controlled by two sets of intake control valves. That is, one set of intake control valves is provided for each of the cylindrical combustion chamber 5 and the annular combustion chamber 9, allowing the gas turbine combustion chambers to operate in different combustion states. The opening degree of the two sets of intake control valves can be controlled by the same intake control unit, which is also used to control the intake air volume of the cooling channel. When the gas turbine requires rotating detonation combustion, the oxidizer supply to the cylindrical combustion chamber 5 is shut off, and the fuel supply is also shut off. When the gas turbine requires conventional slow combustion, the oxidizer supply to the annular combustion chamber 9 is shut off, and the fuel supply is also shut off. During the intermediate transition phase, priority is given to ensuring the stability of detonation combustion, maintaining a high fuel-air equivalence ratio, and preventing detonation failure.

[0063] Example 2

[0064] Based on the combustion chamber of Embodiment 1 above, this embodiment provides a control method for the combustion chamber, the control method comprising the following steps:

[0065] S1: During the gas turbine start-up phase, the starter motor drives the compressor to reach the ignition speed. Before the ignition speed, the intake control valve of the annular combustion chamber 9 is closed, so that all the oxidant at the compressor outlet enters the cylindrical combustion chamber 5 to participate in the traditional slow combustion process.

[0066] S2: After successful ignition, gradually increase the fuel quantity and increase the turbine speed; until 100% speed is reached, the condition of minimum fuel quantity and maximum air quantity is reached; gradually increase the load until 30% of the rated load is reached, and prepare to open the intake control valve of the annular combustion chamber 9. At this time, the intake control valve of the annular combustion chamber 9 should be controlled at the pre-adjusted set opening degree. The cylindrical combustion chamber 5 should be at one end of the adjusted opening degree curve. This opening degree curve ensures that the air distribution in the cylindrical combustion chamber 5 is always at a reasonable value under any operating condition, and there will be no flameout or high fuel-air ratio.

[0067] S3: Open the fuel passage (i.e., detonation nozzle 8) of the annular combustion chamber 9, open the intake control valve of the annular combustion chamber 9, and then start the pre-detonation tube 7 for ignition. At this time, the total fuel flow can theoretically bring the gas turbine to about 80% of its rated load. Maintain this condition for a period of time. After ensuring that there are no abnormalities in the various indicators of the gas turbine, gradually close the fuel passage (i.e., slow combustion nozzle 1) and intake control valve in the cylindrical combustion chamber 5, so that all the fuel enters from the annular combustion chamber 9 and all the air enters the annular combustion chamber 9 and the cooling passage. Observe the various dynamic indicators. After ensuring that all static and dynamic indicators are normal, gradually increase the gas turbine load until it reaches 100% load.

[0068] S4: During the gas turbine shutdown phase, the gas turbine load is gradually reduced to 80%. At this time, the intake control valve of the cylindrical combustion chamber 5 is opened, and a reverse opening curve (opposite to the control curve during the startup phase) is used. The fuel flow in the annular combustion chamber 9 is gradually reduced to the theoretical flow rate of 50% load. The fuel flow in the cylindrical combustion chamber 5 is gradually increased to keep the gas turbine at around 80% load. The fuel flow in the annular combustion chamber 9 is further reduced until the combustion chamber is shut down. Then, the fuel passage and intake valve of the annular combustion chamber 9 are closed. At this time, the operation of the cylindrical combustion chamber 5 can keep the gas turbine at 30% load. The load of the cylindrical combustion chamber 5 is gradually reduced until it is unloaded. The fuel quantity can be gradually reduced, and the turbine speed is gradually reduced. After reaching below 30% speed, all fuel passages are closed. Finally, the gas turbine is turned over to purge residual fuel and cool all components to near room temperature.

[0069] In the above control method, the fuel supply and oxidizer supply of the cylindrical combustion chamber and the annular combustion chamber are reasonably regulated to avoid flameout. At the same time, detonation combustion is given the highest priority to ensure high thermal efficiency.

[0070] In summary, this invention provides a combined rotating detonation combustor and its control method. This combined rotating detonation combustor overcomes the problems of low efficiency, high emissions, and large pressure drop of traditional combustors, enabling gas turbines to exhibit low pollution, high efficiency, and compact structure under high load conditions. Traditional combustors effectively prevent gas turbine failure due to unsuccessful initiation or flameout. This invention also considers cooling design; the inner wall of the annular combustor and the wall of the cylindrical combustor can share a unified cooling system, reducing the complexity of cooling design and manufacturing costs. Furthermore, when the gas turbine is in the transition phase between these two methods, a higher fuel-air ratio for detonation combustion is prioritized. The combustor of this invention combines the advantages of rotating detonation combustion and traditional isobaric combustion, achieving high efficiency while ensuring stability.

[0071] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method of controlling a combined rotary detonation combustion chamber, characterized by, The combined rotating detonation combustion chamber includes: A cylindrical combustion chamber, wherein the cylindrical combustion chamber is used for isobaric combustion; An annular combustion chamber surrounds the outer perimeter of the cylindrical combustion chamber and is used for rotary detonation combustion. A pre-detonation tube is installed on the outer wall of the annular combustion chamber. An intake assembly, located at the front end of the combustion chamber, is used to provide oxidant to the cylindrical combustion chamber and the annular combustion chamber. The intake assembly includes an inlet, a cylindrical connecting part, and a conical connecting part. The cylindrical connecting part and the conical connecting part are coaxially arranged and communicate with the inlet. The rear ends of the cylindrical connecting part and the conical connecting part are respectively connected to the cylindrical combustion chamber and the annular combustion chamber. The inlet is connected to a compressor to provide compressed air or compressed oxygen as oxidant. Each of the cylindrical combustion chamber and the annular combustion chamber is provided with a set of intake control valves to control the opening degree of the oxidant. The annular combustion chamber is connected in sequence to an outlet contraction section and a second throat section at its rear end. The outlet contraction section is used to control the ambient pressure inside the annular combustion chamber. The control method includes the following steps: S1: During the gas turbine start-up phase, the starter motor drives the compressor to reach the ignition speed. Before the ignition speed, the intake control valve of the annular combustion chamber is closed, so that all the oxidant at the compressor outlet enters the cylindrical combustion chamber to participate in the traditional slow combustion process. S2: After successful ignition, gradually increase the fuel quantity and increase the turbine speed; until 100% speed, the condition of minimum fuel quantity and maximum air quantity is reached; gradually increase the load until 30% of the rated load is reached, and prepare to open the intake control valve of the annular combustion chamber. At this time, control the intake control valve of the annular combustion chamber at the pre-adjusted set opening, and at the same time adjust the intake control valve of the cylindrical combustion chamber to ensure that there is no flameout or high fuel-air ratio. S3: Open the fuel passage of the annular combustion chamber and the intake control valve of the annular combustion chamber. Then, start the pre-detonation tube for ignition. At this time, the total fuel flow can theoretically bring the gas turbine to about 80% of its rated load. Maintain this condition for a period of time. After ensuring that there are no abnormalities in the various indicators of the gas turbine, gradually close the fuel passage and intake control valve in the cylindrical combustion chamber, so that all the fuel enters from the annular combustion chamber and all the air enters the annular combustion chamber and the cooling passage. Observe the various dynamic indicators. After ensuring that all static and dynamic indicators are normal, gradually increase the gas turbine load until it reaches 100% load. S4: During the gas turbine shutdown phase, the gas turbine load is gradually reduced to 80%. At this time, the intake control valve of the cylindrical combustion chamber is opened, and the fuel flow in the annular combustion chamber is gradually reduced to the theoretical flow rate of 50% load. The fuel flow in the cylindrical combustion chamber is gradually increased to keep the gas turbine at around 80% load. The fuel flow in the annular combustion chamber is further reduced until the combustion chamber is shut off, and then the fuel passage and intake valve of the annular combustion chamber are closed. At this time, the operation of the cylindrical combustion chamber puts the gas turbine at 30% load. The load of the cylindrical combustion chamber is gradually reduced until it is no load. The fuel quantity is gradually reduced, and the turbine speed is gradually reduced. After reaching below 30% speed, all fuel passages are closed. Finally, the gas turbine is turned over to purge residual fuel and cool all components to near room temperature.

2. The combined rotary detonation combustion chamber of claim 1, wherein: The front end of the cylindrical combustion chamber is connected to a slow-burning nozzle for supplying fuel to the cylindrical combustion chamber. The slow-burning nozzle is coaxially disposed on the inner side of the inlet. The slow-burning nozzle is one of a single-hole nozzle, a multi-hole nozzle, a premixed nozzle, or a combined multi-stage nozzle.

3. The combined rotary detonation combustion chamber of claim 1, wherein: A swirler is installed on the inner wall of the cylindrical connecting part near the rear end of the cylindrical combustion chamber, so that the oxidant passes through the swirler to form an airflow with a certain swirling angle and forms the main recirculation zone, thereby forming the main combustion zone; the rear end side wall of the cylindrical combustion chamber has several mixing holes. The fuel undergoes a chemical reaction in the main combustion zone to form high-temperature flue gas, which mixes with the cold air in the mixing holes to reach the turbine inlet temperature requirement of the gas turbine, and is discharged from the first outlet connected to the rear end of the cylindrical combustion chamber, thereby generating output power.

4. The combined rotary detonation combustion chamber according to claim 1, characterized in that: The conical connecting part is connected to the annular combustion chamber through an inlet contraction section and a first throat section. The first throat section is provided with a detonation nozzle in the radial direction. The detonation nozzle is used to provide fuel to the annular combustion chamber. The detonation nozzle is one of a direct injection ring, an annular array orifice, or a swirl atomizer.

5. The combined rotary detonation combustion chamber according to claim 1, characterized in that: The outer wall of the cylindrical combustion chamber is provided with cooling channels.

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