Reflux air inlet structure of engine and engine

Abstract

The invention relates to the technical field of engines, in particular to a backflow air inlet structure of an engine and the engine, and the backflow air inlet structure of the engine comprises an inner casing, an outer casing, a centrifugal impeller, a detonation tube and a flow guide part, an annular cavity is defined by the inner casing and the outer casing; a radial diffuser and an axial diffuser are arranged between the centrifugal impeller and the annular cavity in a communicating manner; the detonation pipes are evenly distributed in the circumferential direction of the annular cavity. The flow guide part surrounds the multiple detonation pipes and forms a first flow guide channel and a second flow guide channel which communicate with each other with the inner wall of the annular cavity and the outer walls of the detonation pipes in a surrounding mode, the communicating position is located at the end, away from the axial diffuser, of the annular cavity, and an air inlet is formed in the end, away from the communicating position, of each detonation pipe. And the combustion chamber is communicated with the second flow guide channel through the air inlet. According to the technical scheme, back propagation pressure can be effectively restrained, the outer wall of the detonation tube is cooled, the ignition detonation difficulty is lowered, the ignition detonation distance is shortened, and then the overall performance of the engine is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of engines, and particularly relates to a backflow intake structure of an engine and the engine. BACKGROUND

[0002] The pulse detonation turbine engine has high cycle thermal efficiency, unit power and low fuel consumption, and its self-pressurization characteristic can reduce the number of engine compressor stages, thereby improving the engine performance.

[0003] The existing pulse detonation turbine engine mainly consists of a pulse detonation combustion chamber, a compressor and a turbine. Since it is based on constant volume combustion and has a self-pressurization characteristic, it has higher cycle thermal efficiency, higher power-to-weight ratio and lower fuel consumption compared with conventional turbine engines. However, the pressure of the detonation wave formed by the self-pressurization characteristic during detonation combustion will be higher than the outlet air flow pressure of the compressor, so that the detonation wave will propagate upstream, thereby easily affecting the normal operation of the compressor located upstream. In addition, when the engine uses liquid fuel, the atomization and mixing effect between the liquid fuel and air at normal temperature and pressure is poor, which increases the ignition initiation difficulty and distance, resulting in a longer length of the components of the pulse detonation combustion chamber, affecting the overall performance of the engine. At the same time, after a long time of work, the wall temperature of the pulse detonation combustion chamber will rise sharply, resulting in a shortened service life and affecting the stable reliability of the engine. SUMMARY

[0004] In view of the above problems, the present application provides a backflow intake structure of an engine, comprising: An inner casing and an outer casing coaxially arranged, and an annular cavity is formed between the inner casing and the outer casing; A centrifugal impeller rotationally arranged at the end of the inner casing, and a radial diffuser and an axial diffuser are sequentially arranged between the centrifugal impeller and the annular cavity; A plurality of detonation tubes are arranged, and the plurality of detonation tubes are uniformly distributed along the circumference of the annular cavity, and a combustion chamber is arranged in each of the plurality of detonation tubes; A flow guide part is arranged outside the plurality of detonation tubes, and the flow guide part and the inner wall of the annular cavity form a first flow guide channel along the axial direction of the annular cavity, and the flow guide part and the outer wall of the plurality of detonation tubes form a second flow guide channel along the axial direction of the annular cavity; The first flow guide channel and the second flow guide channel are in communication, and the communication position of the first flow guide channel and the second flow guide channel is located at one end of the annular cavity away from the axial diffuser; One end of the detonation tube away from the communication position of the first flow guide channel and the second flow guide channel is provided with an air inlet, and the combustion chamber is in communication with the second flow guide channel through the air inlet; A fuel pipe is provided in the annular cavity, and the fuel pipe is communicated with the combustion chamber.

[0005] In some specific embodiments, the guide portion includes: There are multiple cylinders, each corresponding to the multiple detonation tubes, and each cylinder is disposed around the outside of the corresponding detonation tubes; The outer walls of the plurality of cylinders and the inner wall of the annular cavity are arranged to form the first flow guide channel, and the inner walls of the plurality of cylinders and the outer walls of the corresponding detonation tubes are arranged to form the second flow guide channels; The plurality of second flow guide channels are respectively communicated with the first flow guide channel through the opening ends of the plurality of cylinders.

[0006] In some specific embodiments, the outer walls of the plurality of cylinders are provided with a gap from the inner wall of the annular cavity, and there is a gap between the outer walls of two adjacent cylinders, so that the first flow guide is provided around the outer periphery of the plurality of cylinders; The inner walls of the plurality of cylinders are each provided with a gap from the outer wall of the corresponding detonation tube, so that the plurality of second flow guides are arranged around the outer circumference of the corresponding detonation tube.

[0007] In some specific embodiments, an accommodating cavity is provided at one end of the detonation tube away from the open end of the cylinder, the accommodating cavity is coaxially connected to the combustion chamber, and the air inlet is opened in the radial direction of the accommodating cavity; The accommodating cavity is provided with a swirl blade.

[0008] In some specific embodiments, a plurality of the air inlets are provided, and the plurality of the air inlets are evenly distributed along the circumference of the accommodating cavity.

[0009] In some specific embodiments, a spray port is provided on one side of the accommodating cavity; The fuel pipe is provided with a plurality of output ports, and the plurality of output ports of the fuel pipe correspond one-to-one to the plurality of detonation tubes. The output ports of the fuel pipe are communicated with the corresponding accommodating chambers through the corresponding injection ports.

[0010] In some specific embodiments, the open end of the cylinder is located at an end of the annular cavity away from the axial diffuser, and a baffle is provided at the end of the annular cavity away from the axial diffuser.

[0011] In some specific embodiments, a side of the baffle close to the open end of the cylinder is recessed in a direction away from the open end of the cylinder.

[0012] In some specific embodiments, the detonation tube is arranged through the baffle and in communication with the turbine guide at an end away from the cylinder bottom of the cylinder body; The detonation tube is arranged in communication with the turbine guide at an end away from the cylinder bottom of the cylinder body, and is sequentially arranged with an exhaust transition section and an exhaust mixing section.

[0013] An engine based on the same concept comprises the backflow intake structure of the engine as described in any of the above specific embodiments.

[0014] Compared with the prior art, the backflow intake structure of the engine has at least the following advantages: the flow path of the air is extended through the first and second flow channels, so that the back transmission pressure of the detonation wave generated during detonation combustion can be continuously attenuated through the first and second flow channels, thereby effectively suppressing the back transmission pressure, reducing or even eliminating the influence on the upstream compressor, and when the air passes through the second flow channel formed by the flow guide part and the outer wall of the detonation tube, the air can exchange heat with the outer wall of the detonation tube, thereby cooling the outer wall of the detonation tube to ensure the service life of the detonation tube and avoid affecting the stable reliability of the engine. Meanwhile, the high-temperature air that has completed heat exchange through the second flow channel and reaches the intake port can heat the liquid fuel used after entering the combustion chamber in the detonation tube, thereby increasing the evaporation rate of the liquid fuel, quickly converting the liquid fuel into a gaseous state, improving the atomization and mixing effect between the fuel and the air, reducing the ignition initiation difficulty, and shortening the ignition initiation distance, thereby ensuring the overall performance of the engine.

[0015] The engine of the present application has the same advantages as the backflow intake structure of the engine described above, and thus the detailed description is omitted here.

[0016] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application will be realized and achieved by the structures particularly pointed out in the description and the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0018] Figure 1 The schematic diagram of the backflow intake structure of the engine in the embodiments of the present application is shown. Figure 2 Fig. 3 shows an axial sectional schematic view of the backflow intake structure of the engine in the embodiment of the present application; Figure 3 Fig. 4 shows a partial axial sectional schematic view of the knock pipe and the flow guide in the embodiment of the present application; Figure 4 Fig. 5 shows an enlarged schematic view of A in Fig. 3; Figure 3 Fig. 6 shows an enlarged schematic view of B in Fig. 3. Figure 5 Figure 3 Fig. 7 shows an enlarged schematic view of C in Fig. 3.

[0019] In the figure, 100, outer casing; 200, inner casing; 210, rotating shaft; 300, centrifugal impeller; 310, impeller cover; 320, radial diffuser; 330, axial diffuser; 400, knock pipe; 410, fuel pipe; 420, injection port; 430, swirl vane; 440, venturi; 500, flow guide; 600, baffle; 700, exhaust transition section; 800, exhaust mixing section; 900, turbine guide vane. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0021] Reference Signs List Figure 1 ​The embodiment of the present application provides a backflow air intake structure of an engine, which comprises: coaxially arranged inner casing 200 and outer casing 100, centrifugal impeller 300, knock pipe 400 and flow guide part 500. The annular cavity is formed by surrounding the inner casing 200 and the outer casing 100. The centrifugal impeller 300 is rotationally arranged at the end of the inner casing 200, and the centrifugal impeller 300 and the annular cavity are sequentially communicated with the radial diffuser 320 and the axial diffuser 330. The knock pipe 400 is provided with a plurality of knock pipes 400, which are uniformly distributed along the circumference of the annular cavity, and the plurality of knock pipes 400 are provided with combustion chambers. The flow guide part 500 is arranged outside the plurality of knock pipes 400, and the flow guide part 500 and the inner wall of the annular cavity form a first flow guide channel along the axial direction of the annular cavity, and the flow guide part 500 and the outer wall of the plurality of knock pipes 400 form a second flow guide channel along the axial direction of the annular cavity. The first flow guide channel and the second flow guide channel are communicated, and the communication position of the first flow guide channel and the second flow guide channel is located at one end of the annular cavity away from the axial diffuser 330. The knock pipe 400 is provided with an air inlet at one end away from the communication position of the first flow guide channel and the second flow guide channel, and the combustion chamber is communicated with the second flow guide channel through the air inlet. The annular cavity is provided with a fuel pipe 410, and the fuel pipe 410 is communicated with the combustion chamber.

[0022] Specifically, the inner casing 200 and the outer casing 100 are coaxially arranged, and the outer casing 100 is arranged around the inner casing 200, so that the outer wall of the inner casing 200 and the inner wall of the outer casing 100 form an annular cavity. The shaft 210 is rotationally arranged in the inner casing 200 along the axial direction of the inner casing 200, and the centrifugal impeller 300 is located at the end of the inner casing 200 and connected with one end of the shaft 210, so as to realize the rotational arrangement of the centrifugal impeller 300 at the end of the inner casing 200. The impeller cover 310 is arranged outside the centrifugal impeller 300, so as to transport air to the centrifugal impeller 300 through the air inlet, thereby generating an air flow with circumferential velocity. One end of the impeller cover 310 is communicated with one end of the annular cavity in the axial direction through the sequentially communicated radial diffuser 320 and axial diffuser 330, so that the generated air flow with circumferential velocity can reach the annular cavity after passing through the radial diffuser 320 and the axial diffuser 330.

[0023] The plurality of detonation tubes 400 are uniformly distributed along the circumferential direction of the annular cavity, and each detonation tube 400 is arranged along the axial direction of the annular cavity. Each detonation tube 400 is provided with a combustion chamber for introducing air flow for detonation combustion. The flow guide part 500 is arranged along the axial direction of the annular cavity and surrounds the plurality of detonation tubes 400. The flow guide part 500 is spaced apart from the inner wall of the annular cavity and the outer wall of the detonation tube 400, so that the outer wall of the flow guide part 500 and the inner wall of the annular cavity form a first flow guide channel, and the inner wall of the flow guide part 500 and the outer wall of the detonation tube 400 form a second flow guide channel. The first flow guide channel and the second flow guide channel are in communication with each other, and the communication part of the first flow guide channel and the second flow guide channel is located at one end of the annular cavity away from the axial diffuser 330. The detonation tube 400 is provided with an air inlet at one end away from the communication part of the first flow guide channel and the second flow guide channel. The combustion chamber is in communication with the second flow guide channel through the air inlet, so that the air flow entering the annular cavity can first pass through the first flow guide channel along the axial direction of the annular cavity, then turn back and flow into the second flow guide channel, and after passing through the second flow guide channel along the axial direction of the annular cavity, the air flow reaches the combustion chamber of the detonation tube 400 through the air inlet. The fuel pipe 410 is arranged in the head of the detonation tube 400 and is in communication with the combustion chamber, and is used for outputting liquid fuel. The air flow entering the combustion chamber can contact the liquid fuel output by the fuel pipe 410 to ignite and burn.

[0024] The air flow reaching the annular cavity needs to pass through the first flow guide and the second flow guide in the axial direction of the annular cavity in turn before entering the combustion chamber through the air inlet of the detonation tube 400 to perform detonation combustion, and similarly, the detonation wave generated during detonation combustion needs to pass through the second flow guide and the first flow guide in the axial direction of the annular cavity in reverse order before reaching the centrifugal impeller 300, thereby prolonging the overall flow path, so that the back transmission pressure of the detonation wave generated during detonation combustion can be continuously attenuated through the first flow guide and the second flow guide, thereby effectively suppressing the back transmission pressure to reduce or even eliminate the influence on the upstream compressor, thereby widening the stable working margin of the engine. Moreover, when the air passes through the second flow guide formed by the inner wall of the flow guide part 500 and the outer wall of the detonation tube 400, the air can contact and exchange heat with the outer wall of the detonation tube 400, thereby cooling the outer wall of the detonation tube 400 and effectively reducing the thermal load of the outer wall of the detonation tube 400 to ensure the service life of the detonation tube 400 and avoid affecting the stable reliability of the engine. At the same time, the high-temperature air flow that contacts the outer wall of the detonation tube 400 and completes heat exchange through the second flow guide and reaches the air inlet can heat the liquid fuel output by the fuel pipe 410 after entering the combustion chamber of the detonation tube 400, thereby increasing the evaporation rate of the liquid fuel, enabling the liquid fuel to be converted into a gaseous state more quickly, thereby improving the atomization and mixing effect between the fuel and the air, reducing the ignition initiation difficulty, shortening the ignition initiation distance, improving the service life and reliability of the detonation tube 400, and improving the energy utilization rate to ensure the overall performance of the engine such as the power-to-weight ratio.

[0025] In some embodiments of the present application, the arrows in Figure 1 and Figure 2 , Figure 2 are the airflow flow trajectories during operation, and the flow guide part 500 comprises a plurality of cylinder bodies. The plurality of cylinder bodies are in one-to-one correspondence with the plurality of detonation tubes 400, and the cylinder bodies are arranged outside the corresponding detonation tubes 400. The outer walls of the plurality of cylinder bodies and the inner wall of the annular cavity form the first flow guide, and the inner walls of the plurality of cylinder bodies and the outer walls of the corresponding detonation tubes 400 form the plurality of second flow guides. The plurality of second flow guides are in communication with the first flow guide through the opening ends of the plurality of cylinder bodies.

[0026] Specifically, the plurality of barrels are arranged along the axial direction of the annular cavity, and the plurality of barrels are uniformly distributed along the circumferential direction of the annular cavity, so that the plurality of barrels correspond to the plurality of detonation tubes 400 one by one, and each barrel is arranged around the corresponding detonation tube 400 along the axial direction of the annular cavity by the end of the corresponding detonation tube 400 provided with the air inlet, so that the air inlet of the detonation tube 400 is located at the barrel bottom of the corresponding barrel. The inner wall of the barrel and the outer wall of the corresponding detonation tube 400 are arranged at intervals, so that the inner wall of each barrel and the outer wall of the corresponding detonation tube 400 form a second flow guide channel, and the outer wall and the inner wall of the annular cavity are arranged at intervals, so that the outer wall of the plurality of barrels and the inner wall of the annular cavity form a first flow guide channel. The end of each barrel away from the air inlet of the corresponding detonation tube 400 is an open structure, so that the first flow guide channel communicates with the plurality of second flow guide channels through the open ends of the plurality of barrels. The air flow reaching the annular cavity can first pass through the first flow guide channel along the axial direction of the annular cavity, then turn and flow back into each second flow guide channel through the open end of each barrel, and after passing through the second flow guide channel along the axial direction of the annular cavity, reach the combustion chamber through the air inlet of the corresponding detonation tube 400 for detonation combustion.

[0027] In some embodiments of the present application, the arrows in Figure 1 and Figure 2 , Figure 2 are the airflow flow trajectories during operation, the outer walls of the plurality of barrels are arranged at intervals with the inner wall of the annular cavity, and the outer walls of the adjacent two barrels have gaps, so that the first flow guide channel is arranged around the outer periphery of the plurality of barrels. The inner wall of the plurality of barrels is arranged at intervals with the outer wall of the corresponding detonation tube 400, so that the plurality of second flow guide channels are arranged around the outer periphery of the corresponding detonation tube 400.

[0028] Specifically, the outer walls of the plurality of barrels are arranged at intervals with the inner wall of the annular cavity, and the outer walls of every adjacent two barrels are also arranged at intervals, so that the first flow guide channel can completely cover the outer periphery of each barrel, thereby expanding the flow space of the air flow, so as to facilitate the smooth passage of the air flow through the first flow guide channel, and also can disperse the back transmission pressure when the detonation wave generated during detonation combustion is back transmitted, so as to facilitate the attenuation of the back transmission pressure. At the same time, the inner walls of the plurality of barrels are arranged at intervals with the outer walls of the corresponding detonation tubes 400, so that the second flow guide channels can completely cover the outer periphery of the corresponding detonation tubes 400, thereby expanding the flow space of the air flow, so as to facilitate the smooth passage of the air flow through the second flow guide channel, and also can disperse the back transmission pressure when the detonation wave generated during detonation combustion is back transmitted, so as to facilitate the attenuation of the back transmission pressure. At the same time, because the inner wall of the open end of the barrel and the outer wall of the detonation tube 400 are arranged at intervals, the air flow can reach the second flow guide channel from the first flow guide channel.

[0029] In some embodiments of the present application, with reference to Figure 3 , Figure 4 and Figure 5 , Figure 4 and Figure 5 , the arrow is the airflow flow trajectory during operation, the end of the detonation tube 400 away from the open end of the cylinder is provided with a containing cavity coaxially communicated with the combustion chamber, and the air inlet is arranged in the radial direction of the containing cavity. The containing cavity is provided with a swirl vane 430.

[0030] Specifically, the end of the detonation tube 400 close to the cylinder bottom of the cylinder is provided with a containing cavity, the containing cavity is coaxially arranged with the combustion chamber and communicated with each other, wherein the air inlet is located in the radial direction of the containing cavity, so that the air flow passing through the second flow guide can enter the containing cavity from the radial direction of the containing cavity. The containing cavity is provided with a swirl vane 430, which is coaxially arranged with the combustion chamber, so that the structure of the swirl vane 430 can guide the air flow entering the containing cavity to have a circumferential velocity, forming a swirling air flow, so as to improve the atomization and mixing effect after contacting with the liquid fuel output by the fuel pipe 410, so that the liquid fuel and the air flow can form a uniform and high-quality premixed gas in a short distance, thereby reducing the difficulty of ignition and detonation, shortening the length of the detonation chamber, and improving the overall performance of the engine power-to-weight ratio.

[0031] And, because the air inlet is located in the radial direction of the containing cavity, the air flow passing through the second flow guide can enter the containing cavity from the radial direction of the containing cavity, thereby forming circumferential air inlet instead of axial air inlet. Therefore, from the axial direction, the end of the detonation tube 400 close to the cylinder bottom of the cylinder forms a closed structure, which not only can enhance the shock wave reflection and promote the detonation initiation, but also can effectively suppress the pressure reflection, further reducing or even eliminating the influence on the upstream compressor.

[0032] Further, the containing cavity and the combustion chamber are communicated with a venturi 440, which can reduce the difficulty of detonation initiation and promote the formation of detonation wave.

[0033] In some embodiments of the present application, with reference to Figure 4 , Figure 4 , the arrow is the airflow flow trajectory during operation, the air inlet is arranged in multiple, and the multiple air inlets are uniformly distributed along the circumference of the containing cavity.

[0034] Specifically, the air inlet is arranged in multiple, and the multiple air inlets are uniformly distributed along the circumference of the containing cavity, so that the air flow passing through the second flow guide can enter the containing cavity from any position on the circumference of the containing cavity, to ensure smooth flow of the air flow.

[0035] In some embodiments of the present application, with reference to Figure 4 ,Figure 4 The arrow in the figure is the airflow flow trajectory when working, and one side of the accommodating cavity is provided with an injection port 420. The fuel pipe 410 is provided with a plurality of output streams, and the output ports of the fuel pipe 410 correspond to the plurality of cylinder bodies one by one. The output port of the fuel pipe 410 is arranged in the head of the corresponding detonation pipe and is connected with the corresponding accommodating cavity through the corresponding injection port 420.

[0036] Specifically, one side of the accommodating cavity is provided with an injection port 420, and the output end of the injection port 420 is coaxially arranged with the accommodating cavity and the combustion chamber. The output port of the fuel pipe 410 is arranged in the head of the corresponding detonation pipe to the injection port 420 and is connected with the input end of the injection port 420, so that the liquid fuel output by the fuel pipe 410 can be sprayed in the axial direction of the accommodating cavity. Wherein, the air flow passing through the second flow guide can enter the accommodating cavity from the radial direction of the accommodating cavity, and after contacting the swirl vane 430, the air flow reaching the accommodating cavity is guided by the swirl vane 430 to have a circumferential velocity, forming a swirl air flow, and the liquid fuel output by the output port of the fuel pipe 410 can be sprayed in the axial direction of the accommodating cavity. The axial injection of the liquid fuel makes part of the air flow have an axial velocity, forming an axial flow air flow. Due to the velocity difference between the swirl air flow and the axial flow air flow, the atomization and mixing effect between the liquid fuel and the air flow can be further improved, and the liquid fuel and the air flow can form a uniformly distributed and high-quality premixed gas in a shorter distance, thereby further reducing the ignition difficulty, shortening the length of the detonation chamber, and improving the overall performance of the engine power-to-weight ratio.

[0037] In some embodiments of the present application, with reference to Figure 1 and Figure 2 , Figure 2 The arrow in the figure is the airflow flow trajectory when working, and the open end of the cylinder body is located at one end of the annular cavity away from the axial diffuser 330, and the one end of the annular cavity away from the axial diffuser 330 is provided with a baffle 600.

[0038] Specifically, the open end of the cylinder is located at one end of the annular cavity away from the axial diffuser 330, so that the communication between the first flow guide channel and the second flow guide channel is also located at one end of the annular cavity away from the axial diffuser 330, so that the air flow reaching the annular cavity can only flow in the first flow guide channel along the axial direction of the annular cavity to reach the communication between the first flow guide channel and the second flow guide channel and enter the second flow guide channel, and because the air inlet of the detonation tube 400 is located at the bottom of the cylinder, the air flow reaching the second flow guide channel can only flow in the second flow guide channel along the axial direction of the annular cavity to reach the air inlet of the detonation tube 400 and enter the containing cavity. Furthermore, the one end of the annular cavity away from the axial diffuser 330 is also provided with a baffle 600, the baffle 600 is arranged opposite to the first flow guide channel and the second flow guide channel, and the open end of the cylinder is spaced apart from the baffle 600, so that the space between the open end of the cylinder and the baffle 600 forms the communication between the first flow guide channel and the second flow guide channel. The air flow reaching the annular cavity flows in the first flow guide channel along the axial direction of the annular cavity, and when the air flow reaches the communication between the first flow guide channel and the second flow guide channel, the air flow will impact the side wall of the side of the baffle 600 close to the open end of the cylinder, so that the air flow is turned and enters the second flow guide channel from the open end of the cylinder under the action of the baffle 600, thereby realizing the turning and rotation of the air flow between the first flow guide channel and the second flow guide channel, so that the flow path of the air flow can be lengthened.

[0039] In some embodiments of the present application, referring to the arrows in Figure 1 and Figure 2 , Figure 2 , the arrow is the airflow flow trajectory when working, and the side of the baffle 600 close to the open end of the cylinder is recessed away from the open end of the cylinder.

[0040] Specifically, when the air flow reaches the communication between the first flow guide channel and the second flow guide channel, the air flow will impact the side wall of the side of the baffle 600 close to the open end of the cylinder, so that the air flow is turned and enters the second flow guide channel from the open end of the cylinder under the action of the baffle 600, thereby realizing the turning and rotation of the air flow between the first flow guide channel and the second flow guide channel, so that the flow path of the air flow can be lengthened.

[0041] In some embodiments of the present application, referring to the arrows in Figure 1 and Figure 2 , Figure 2 , the arrow is the airflow flow trajectory when working, and the one end of the detonation tube 400 away from the bottom of the cylinder is threaded through the baffle 600 and communicated with the turbine guide 900. The one end of the detonation tube 400 away from the bottom of the cylinder and the turbine guide 900 are sequentially communicated with the exhaust transition section 700 and the exhaust mixing section 800.

[0042] Specifically, the detonation tube 400 is arranged in the baffle 600 and sequentially communicates with the exhaust transition section 700, the exhaust mixing section 800 and the turbine guide 900. After the liquid fuel and the air flow form the pre-mixed gas with uniform distribution and high quality, the slow combustion wave generated after the ignition and combustion of the pre-mixed gas can develop into a stable detonation wave in the combustion chamber under the action of the obstacles in the combustion chamber, and high-temperature and high-pressure gas is formed. The high-temperature and high-pressure gas can be discharged from the end of the detonation tube 400 away from the bottom of the cylinder, and pass through the exhaust transition section 700 and the exhaust mixing section 800 in sequence to reach the turbine guide 900. Under the action of the turbine guide 900, the flow direction of the high-temperature and high-pressure gas is changed to axial, and the high-temperature and high-pressure gas in the axial flow direction can impact the turbine blades, so that the turbine blades work, and the power generated by the working of the turbine blades is transmitted through the shaft 210 to drive the compressor and the accessory drive device, and finally the gas is discharged into the atmosphere.

[0043] It should be noted that the baffle 600 does not completely seal the annular cavity, so that part of the air flow passing through the first flow channel can be diverted back into the second flow channel through the recess of the baffle 600, and another part of the air flow passing through the first flow channel can directly flow to the turbine blades through the baffle 600, thereby cooling the turbine blades.

[0044] The embodiment of the present application also provides an engine, which comprises the backflow intake structure of the engine according to any one of the above embodiments.

[0045] Specifically, by arranging the first flow guide channel and the second flow guide channel of the backflow intake structure of the engine, the air flow reaching the annular cavity needs to pass through the first flow guide channel and the second flow guide channel in the axial direction of the annular cavity in turn before entering the combustion chamber through the intake port of the detonation tube 400 to perform detonation combustion. Similarly, the detonation wave generated during detonation combustion needs to pass through the second flow guide channel and the first flow guide channel in the axial direction of the annular cavity in reverse order before reaching the centrifugal impeller 300, thereby prolonging the overall flow path, so that the back transmission pressure of the detonation wave generated during detonation combustion can be continuously attenuated through the first flow guide channel and the second flow guide channel, thereby effectively suppressing the back transmission pressure to reduce or even eliminate the influence on the upstream compressor, thereby widening the stable working margin of the engine. Moreover, when the air passes through the second flow guide channel formed by the inner wall of the flow guide part 500 and the outer wall of the detonation tube 400, the air can contact and exchange heat with the outer wall of the detonation tube 400, thereby cooling the outer wall of the detonation tube 400 and effectively reducing the thermal load of the outer wall of the detonation tube 400 to ensure the service life of the detonation tube 400 and avoid affecting the stable reliability of the engine. At the same time, the high-temperature air flow that contacts and completes heat exchange with the outer wall of the detonation tube 400 through the second flow guide channel and reaches the intake port can heat the liquid fuel output by the fuel pipe 410 after entering the combustion chamber of the detonation tube 400, thereby increasing the evaporation rate of the liquid fuel and enabling the liquid fuel to be converted into a gaseous state more quickly, thereby improving the atomization and mixing effect between the fuel and the air, reducing the ignition initiation difficulty, shortening the ignition initiation distance, improving the service life and reliability of the detonation tube 400, and improving the energy utilization rate to ensure the overall performance of the engine such as power-to-weight ratio.

[0046] Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents; and such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A reflux air intake structure of an engine, characterized in that: include: An inner casing (200) and an outer casing (100) are coaxially arranged, and an annular cavity is formed between the inner casing (200) and the outer casing (100); a centrifugal impeller (300) rotatably disposed at the end of the inner casing (200), and a radial diffuser (320) and an axial diffuser (330) are sequentially disposed between the centrifugal impeller (300) and the annular cavity; A plurality of detonation tubes (400) are provided, the plurality of detonation tubes (400) being evenly distributed along the circumference of the annular cavity, and a combustion chamber being provided in each of the plurality of detonation tubes (400); A flow guide portion (500) is arranged outside the plurality of detonation tubes (400), wherein the flow guide portion (500) and the inner wall of the annular cavity are arranged along the axial direction of the annular cavity to form a first flow guide channel, and the flow guide portion (500) and the outer walls of the plurality of detonation tubes (400) are arranged along the axial direction of the annular cavity to form a second flow guide channel; The first flow guide channel and the second flow guide channel are in communication, and the communication point between the first flow guide channel and the second flow guide channel is located at an end of the annular cavity away from the axial diffuser (330); An air inlet is provided at one end of the detonation tube (400) away from the connection point between the first flow guide channel and the second flow guide channel, and the combustion chamber is connected to the second flow guide channel through the air inlet; A fuel pipe (410) is provided in the annular cavity, and the fuel pipe (410) is communicated with the combustion chamber.

2. The engine return air intake structure according to claim 1, characterized in that: The flow guide (500) comprises: A plurality of cylinders are provided, the plurality of cylinders corresponding to the plurality of detonation tubes (400) on a one-to-one basis, and the cylinders are arranged around the outside of the corresponding detonation tubes (400); The outer walls of the plurality of cylinders and the inner wall of the annular cavity are arranged to form the first flow guide channel, and the inner walls of the plurality of cylinders and the outer walls of the corresponding detonation tubes (400) are arranged to form the second flow guide channels; The plurality of second flow guide channels are respectively communicated with the first flow guide channel through the opening ends of the plurality of cylinders.

3. The engine return air intake structure according to claim 2, characterized in that: The outer walls of the plurality of cylinders are provided with gaps from the inner wall of the annular cavity, and there is a gap between the outer walls of two adjacent cylinders, so that the first flow guide is provided around the outer periphery of the plurality of cylinders; The inner walls of the plurality of cylinders are each provided with a gap from the outer wall of the corresponding detonation tube (400), so that the plurality of second flow guides are arranged around the outer periphery of the corresponding detonation tube (400).

4. The engine return air intake structure according to claim 3, characterized in that: An accommodating cavity is provided at one end of the detonation tube (400) away from the open end of the cylinder, the accommodating cavity is coaxially connected to the combustion chamber, and the air inlet is opened in the radial direction of the accommodating cavity; A swirl blade (430) is provided in the accommodating cavity.

5. The engine return air intake structure according to claim 4, characterized in that: There are multiple air inlets, and the multiple air inlets are evenly distributed along the circumference of the accommodating cavity.

6. The engine return air intake structure according to claim 4, characterized in that: A spray port (420) is provided on one side of the accommodating cavity; The fuel pipe (410) is provided with a plurality of output ports, the plurality of output ports of the fuel pipe (410) corresponding one-to-one to the plurality of detonation tubes (400), and the output ports of the fuel pipe (410) are connected to the corresponding accommodating chambers through the corresponding injection ports (420).

7. The engine return air intake structure according to claim 2, characterized in that: The open end of the cylinder is located at an end of the annular cavity away from the axial diffuser (330), and a baffle (600) is provided at the end of the annular cavity away from the axial diffuser (330).

8. The engine return air intake structure according to claim 7, characterized in that: The baffle (600) is arranged to be recessed on a side close to the open end of the cylinder in a direction away from the open end of the cylinder.

9. The engine return air intake structure according to claim 7, characterized in that: One end of the detonation tube (400) away from the bottom of the cylinder body is passed through the baffle (600) and is connected to a turbine guide (900); An exhaust transition section (700) and an exhaust mixing section (800) are sequentially connected between the end of the detonation tube (400) away from the bottom of the cylinder and the turbine guide (900).

10. An engine, characterized in that: include: The engine return air intake structure according to any one of claims 1 to 9.

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