Pulse detonation combustor with air guiding device and air-breathing pulse detonation engine

Abstract

To solve the problems of the complex structure of the mechanical valve type reverse transmission suppression mechanism of the air-breathing pulse detonation engine and the difficulties in valve driving and opening / closing control, the present invention proposes a pulse detonation combustion chamber with an air guiding device and an air-breathing pulse detonation engine. On the basis of the traditional pulse detonation combustion chamber, an air guiding transmission device and a transmission spring for rebounding and resetting the air guiding transmission device when it is depressurized are added to each detonation combustion device. Each air guiding transmission device is driven by a part of the energy gas led out from its corresponding detonation combustion device, compresses the transmission spring and generates an axial displacement; the output ends of all the air guiding transmission devices are cooperatively connected with the mechanical rotary valve, and convert their axial displacements into the circumferential rotation of the mechanical rotary valve. The present invention can adaptively realize the oncoming flow filling and reverse transmission isolation, without additionally arranging a driving motor, a signal acquisition unit and a motor control unit for the valve, and has a simpler structure, lower cost and higher reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and particularly to an anti-backflow suppression mechanism, a pulse detonation combustor, and a pulse detonation engine using the pulse detonation combustor. Background Art

[0002] An air-breathing pulse detonation engine is a power device that uses high-temperature and high-pressure gas generated by intermittent or pulsed detonation waves to obtain thrust. The pulse detonation cycle has characteristics such as high thermal cycle efficiency, low fuel consumption rate, wide working and applicable ranges, low pollution, and self-boost in the combustion process, and is considered to be the most likely thermal cycle method to replace the isobaric cycle in traditional turbine engines.

[0003] According to the working principle and structure of the engine, air-breathing pulse detonation engines are divided into two categories: "pure" air-breathing pulse detonation engines and pulse detonation turbine engines. Among them, the "pure" air-breathing pulse detonation engine mainly consists of an intake duct, a detonation combustor, and a nozzle. It directly discharges the high-temperature and high-pressure products generated by detonation combustion at high speed through the tail nozzle to generate thrust. The pulse detonation turbine engine uses a pulse detonation combustor to replace the isobaric combustors (including afterburners and main combustors) in traditional turbine engines. This type of engine combines the advantages of the detonation cycle with the high mechanical power extraction advantage of traditional turbine engines, greatly improving the performance of traditional gas turbine engines.

[0004] Due to the non-steady-state boosting characteristic of pulse detonation combustion, both "pure" air-breathing pulse detonation engines and pulse detonation turbine engines will generate periodic pressure and burned gas propagating upstream to the engine during the operation of the detonation combustor, that is, the backflow phenomenon. When the backflow pressure and gas act on the intake duct or the compressor outlet, it will affect the normal operation of the intake duct or the compressor, reduce the efficiency of the intake duct or the compressor, and even cause serious consequences such as non-starting of the intake duct or compressor surge in severe cases. At the same time, the change in the working characteristics of the intake duct or the compressor changes the intake conditions of the detonation combustor, resulting in the influence on the detonation initiation process and backflow characteristics of the detonation combustor, and even causing engine flameout in severe cases.

[0005] Regarding the problems of the pressure in the pulse detonation combustor and the reverse transmission of combustion gas, the vast majority of existing research is to design a suitable reverse transmission suppression mechanism in front of the detonation combustor to prevent the pressure and combustion gas from being reversed to the intake duct or the compressor. According to the structure and principle of the reverse transmission suppression mechanism, the reverse transmission suppression mechanism of the air-breathing pulse detonation engine can be divided into two types: pneumatic valve type and mechanical valve type. The pneumatic valve type reverse transmission suppression mechanism solves the problems of the periodic pressure and the reverse transmission of combustion gas in the pulse detonation combustor to a certain extent through reasonable and ingenious flow channel design. This scheme has a simple structure and is easy to achieve high-frequency operation, but the structural size is relatively large, and it cannot completely isolate the reverse transmission of the detonation combustor pressure. For example, the conical pneumatic valve proposed by Srnirnov et al., the cyclone type pneumatic valve proposed by Fan Yuxin, Wang Jiahua et al., and the bluff body with a cover pneumatic valve proposed by He Xiaomin et al. The mechanical valve type reverse transmission suppression mechanism solves the problems of the pressure and the reverse transmission of combustion gas in the detonation combustor by installing a periodically opened and closed mechanical valve in front of the detonation combustor. For example, the new rotary valve type multi-tube pulse detonation engine concept proposed by the American ASI Company, and the valve system of the pulse detonation engine proposed by Matsuoka et al. The mechanical valve type reverse transmission suppression mechanism can isolate the high-temperature and high-pressure combustion products from the upstream steady-state components. Compared with the pneumatic valve type structure, the reverse transmission suppression of the mechanical valve type structure is more thorough, and the structural size is smaller, but the structure is more complex, and currently, most mechanical valves use external motors to drive, and there is no effective solution for the reliable control of valve driving and opening and closing. Summary of the Invention

[0006] In order to solve the technical problems that the mechanical valve type reverse transmission suppression mechanism of the air-breathing pulse detonation engine is complex and there are difficulties in valve driving and opening and closing control, the present invention provides a pulse detonation combustor with a gas guiding device, which realizes the reverse transmission isolation of the detonation combustor and the adaptive filling of the detonation chamber. In addition, the present invention also provides a pulse detonation engine adopting the pulse detonation combustor. Further, the present invention also provides a reverse transmission suppression mechanism.

[0007] The technical solution of the present invention:

[0008] A reverse transmission suppression mechanism is used to prevent the pressure and combustion gas from being reversed to the intake duct or the compressor of the air-breathing pulse detonation engine; the reverse transmission suppression mechanism includes a mechanical rotary valve, and the mechanical rotary valve is used to realize the connection and disconnection between each group of detonation combustion units in the air-breathing pulse detonation engine and the air flow; each group of the detonation combustion units includes a plurality of detonation combustion devices.

[0009] The special feature is that:

[0010] The reverse transmission suppression mechanism further includes a gas guiding transmission device whose quantity matches the total quantity of the detonation combustion devices in the air-breathing pulse detonation engine and a transmission spring for making it rebound and reset when the gas guiding transmission device relieves pressure.

[0011] Each gas guiding transmission device is driven by a part of the energy gas led out from its corresponding knock combustion device, compresses the transmission spring and generates an axial displacement;

[0012] The output ends of all the gas guiding transmission devices are cooperatively connected with the mechanical rotary valve, and can convert their axial displacements into circumferential rotations of the mechanical rotary valve to drive its opening / closing and opening degree control.

[0013] Further preferably, the knock combustion device includes a knock tube, a spark plug, an injector and a gas guiding cylinder arranged on the knock tube; the gas guiding transmission device takes a part of the energy gas from the knock tube through the gas guiding cylinder as the driving gas.

[0014] Further preferably, the distance between the gas guiding cylinder and the spark plug is greater than or equal to 300 mm and less than or equal to 400 mm.

[0015] The present invention also provides a pulse detonation combustion chamber with a gas guiding device, which includes an anti-backflow suppression mechanism, multiple groups of knock combustion units and a support structure;

[0016] The anti-backflow suppression mechanism includes a mechanical rotary valve, and the mechanical rotary valve is used to realize the connection and disconnection between the knock combustion unit and the air inflow;

[0017] Each group of the knock combustion units includes a plurality of knock combustion devices for generating detonation waves;

[0018] The support structure is used to fixedly constrain the multiple groups of knock combustion units on the engine;

[0019] The special feature lies in that:

[0020] The anti-backflow suppression mechanism further includes a gas guiding transmission device with a quantity matching the total quantity of the knock combustion devices and a transmission spring for enabling the gas guiding transmission device to rebound and reset when the pressure is released;

[0021] Each gas guiding transmission device is driven by a part of the energy gas led out from its corresponding knock combustion device, compresses the transmission spring and generates an axial displacement;

[0022] The output ends of all the gas guiding transmission devices are cooperatively connected with the mechanical rotary valve, and can convert their axial displacements into circumferential rotations of the mechanical rotary valve to drive its opening / closing and opening degree control.

[0023] Further preferably, the knock combustion device includes a knock tube, a spark plug, an injector and a gas guiding cylinder; the output end of the gas guiding cylinder is connected with the gas guiding transmission device, and is used to lead out a part of the energy gas from the knock tube to drive the gas guiding transmission device to act.

[0024] Further preferably, the distance between the air guide cylinder and the spark plug is greater than or equal to 300 mm and less than or equal to 400 mm.

[0025] Further preferably, the mechanical rotary valve includes an annular valve body, a connection structure and a central bearing which are arranged in sequence from outside to inside; N holes are formed in the end face of the annular valve body and are evenly distributed along the same circumferential direction. The inner diameter of the holes matches the inner diameter of the detonation tube of the detonation combustion device. The number N of the holes is 1 / k of the total number of detonation combustion devices, where k is an integer greater than 1 and less than 5, and N is an integer greater than or equal to 2; a sliding groove is arranged on the inner wall surface of the inner ring of the annular valve body; the sliding groove extends in the form of a sine curve with a minimum period of 2π / kN. If the wave trough of the sine curve corresponds to the hole, the wave trough, the axis of the hole and the axis of the annular valve body are coplanar;

[0026] Each air guide transmission device includes a sliding pin box, a transmission rod and an air guide cylinder sleeve which are connected in sequence; the sliding pin box is composed of a sliding pin, a support spring and an outer cover of the sliding pin box. The sliding pin is installed in the middle of the outer cover of the sliding pin box and extends out of the outer cover of the sliding pin box. The sliding pin is used for cooperating with the sliding groove on the mechanical rotary valve for transmission. The support spring is installed in the outer cover of the sliding pin box and is located at the bottom of the sliding pin to apply pressure to it so that the sliding pin always keeps in close contact with the sliding groove; a boss is arranged in the middle of the transmission rod for limiting the transmission spring; the air guide cylinder sleeve includes an air guide cavity and a circumferential fixing structure. A plurality of pressure relief holes are evenly arranged on the side wall of the air guide cavity along the circumferential direction; the circumferential fixing structure has a plurality of insertion columns;

[0027] An annular disc with a plurality of clamping windows on its end face is sleeved in the middle of the air guide cylinder;

[0028] The insertion columns of the circumferential fixing structure are in one-to-one correspondence with the clamping windows of the annular disc to realize insertion connection, connecting the air guide cavity with the air guide cylinder;

[0029] Two types of transmission rod support structures are arranged on the side wall of the detonation tube. The first type of transmission rod support structure is located on the side wall of the end of the detonation tube and in the area close to the air guide cylinder, and is only used for supporting the transmission rod in the air guide transmission device; the second type of transmission rod support structure is located on the side wall of the end of the detonation tube and in the area close to the mechanical rotary valve, and is used for supporting the transmission rod in the air guide transmission device and for limiting the transmission spring;

[0030] The transmission spring is sleeved on the transmission rod, and the two ends are respectively limited by the boss and the second type of transmission rod support structure.

[0031] Further preferably, the inner ring side wall of the annular valve body extends axially outward by a certain distance to provide a sufficient installation surface for the connection structure, and the outer ring side wall of the annular valve body extends axially outward by a certain distance to form a radial limiting surface of the detonation tube.

[0032] Further preferably, the holes on the end face of the annular valve body are round holes.

[0033] In addition, the present invention also provides a pulse detonation engine with air intake, including a pulse detonation combustion chamber; the special feature is that: the pulse detonation combustion chamber adopts the above-mentioned pulse detonation combustion chamber with an air guiding device.

[0034] The beneficial effects of the present invention:

[0035] 1. The pulse detonation combustion chamber of the present invention adds an air guiding transmission device for each detonation combustion device on the basis of the traditional pulse detonation combustion chamber. Each air guiding transmission device is driven by a part of the energy gas led out from its corresponding detonation combustion device, compresses the transmission spring and generates an axial displacement. The output ends of all air guiding transmission devices are cooperatively connected with the mechanical rotary valve, and can convert its axial displacement into the circumferential rotation of the mechanical rotary valve, driving its opening and closing and opening degree control. When the mechanical rotary valve rotates to disconnect a certain detonation combustion unit from the oncoming flow path, it plays a role of isolation and reversal. At the same time, the position of the mechanical rotary valve will connect another detonation combustion unit with the oncoming flow, and this detonation combustion unit is in the self-adaptive filling stage. The present invention can achieve self-adaptive oncoming flow filling and reverse transmission isolation without additionally setting a driving motor, a signal acquisition unit and a motor control unit for the valve, with a simpler structure, lower cost and higher reliability.

[0036] 2. The pulse detonation combustion chamber of the present invention is specifically provided with a gas guide cylinder communicated with the side wall of the detonation tube of the detonation combustion device. The input end of the gas guide transmission device is connected and communicated with the gas guide cylinder on the side wall of the detonation tube of the detonation combustion device, and the output end of the gas guide transmission device is matched with the mechanical rotary valve. After the stable detonation wave is formed in the detonation tube of the detonation combustion device, the high-pressure gas after the detonation wave enters the input end of the gas guide transmission device through the gas guide cylinder on the side wall of the detonation tube, and under the action of the pressure difference, it drives the gas guide transmission device to generate an axial movement, thereby driving the mechanical rotary valve to rotate, realizing the opening and closing and opening degree control of the mechanical rotary valve. As the gas guide transmission device generates a displacement upstream (the air inflow direction), the transmission spring between the boss in the middle of the transmission rod in the gas guide transmission device and the transmission rod support structure on the side wall of the detonation tube in the detonation combustion device is gradually compressed. The pressure relief hole on the gas guide chamber in the gas guide transmission device is displaced to the left side of the gas guide cylinder on the side wall of the detonation tube, and the high-pressure gas in the gas guide chamber and the gas guide cylinder is released, reducing the internal and external pressure difference. The gas guide transmission device gradually returns to the initial position under the action of the transmission spring, and the mechanical rotary valve also continues to rotate to the closed position under its drive, realizing the function of cutting off the inflow flow path and isolating the reverse transmission. At the same time, the position of the mechanical rotary valve enables the adjacent detonation combustion units to be communicated with the inflow, realizing the self-adaptive filling of the detonation tube. Compared with the traditional pulse detonation combustion chamber with a pneumatic valve type reverse transmission suppression mechanism, the reverse transmission suppression of the present invention is more thorough and the structural size is smaller. Compared with the traditional pulse detonation combustion chamber with a mechanical type reverse transmission suppression mechanism, the present invention can realize the inflow filling and reverse transmission isolation self-adaptively, without additionally setting a driving motor, a signal acquisition unit and a motor control unit for the valve, with a simpler structure, lower cost and higher reliability.

[0037] 3. In the pulse detonation combustion chamber of the present invention, the gas guide cylinder is located in the middle of the detonation tube and the interval from the spark plug is between 300 mm and 400 mm. If the interval is too short, it may cause that a stable detonation wave cannot be formed in front of the spark plug, reducing the pressure entering the gas guide cylinder and unable to reliably drive the gas guide transmission device; while if the interval is too long, it will cause an increase in the length of the transmission rod and a reduction in the reliability of the transmission device.

[0038] 3. In the pulse detonation combustion chamber of the present invention: the number N of holes on the end face of the annular valve body is 1 / k of the total number of detonation combustion devices, k is an integer and 1 < k < 5, N is an integer and 2 ≤ N; the chute on the inner wall surface of the inner ring of the annular valve body extends in the form of a sine curve with a minimum period of 2π / kN. If there is a corresponding hole at the trough of the sine curve, the axis of the trough, the axis of the hole and the axis of the annular valve body are coplanar; the design of the above structural parameters can meet the requirement that when the mechanical rotary valve rotates, the intake air flow rates of the detonation tubes belonging to the same detonation combustion unit are the same, enabling the working states of the detonation combustion devices and the gas guide transmission devices in the same detonation combustion unit to be the same, and improving the reliability of the coordinated work of each component of the detonation combustion chamber.

[0039] 4. In the pulse detonation combustor of the present invention, the circular holes formed on the end face of the annular valve body enable the detonation chamber flow passage to closely fit with the annular valve body flow passage during the filling stage, reducing the total pressure loss to a certain extent. During the detonation initiation and propagation stages, the circular holes on the end face of the annular valve body can quickly cut off the flow path under the drive of the air guiding transmission device, timely suppressing the reverse transmission of the detonation combustor.

[0040] 5. The circumferential fixing structure in the air guiding transmission device of the pulse detonation combustor of the present invention matches the fan-shaped window on the end face of the annular disk in the middle of the air guiding cylinder in the detonation combustion device, which can avoid the circumferential displacement of the air guiding transmission device caused by engine vibration.

[0041] 6. The pulse detonation combustor of the present invention can directly replace the detonation combustor in the existing air-breathing pulse detonation engine (including the "pure" air-breathing pulse detonation engine and the pulse detonation turbine engine). It has strong replaceability and low improvement cost. Through actual verification, the comprehensive performance of the new air-breathing pulse detonation engine obtained after replacing the pulse detonation combustor has been significantly improved.

[0042] 7. The reverse transmission suppression mechanism of the present invention has thorough reverse transmission suppression, and is simple in structure, small in size, low in cost, and high in reliability. Description of the Drawings

[0043] Figure 1 It is the overall three-dimensional structure schematic diagram of the present invention.

[0044] Figure 2 It is the overall sectional schematic diagram of the present invention.

[0045] Figure 3 It is the three-dimensional structure schematic diagram of the mechanical rotary valve in the present invention.

[0046] Figure 4 It is the sectional schematic diagram of the mechanical rotary valve in the present invention.

[0047] Figure 5 It is the three-dimensional structure schematic diagram of the annular valve body in the mechanical rotary valve.

[0048] Figure 6 It is the sectional schematic diagram of the annular valve body in the mechanical rotary valve.

[0049] Figure 7 It is the three-dimensional structure schematic diagram of the detonation combustion device in the present invention.

[0050] Figure 8 It is the sectional schematic diagram of the detonation combustion device in the present invention.

[0051] Figure 9 It is the three-dimensional structure schematic diagram of the air guiding transmission device in the present invention.

[0052] Figure 10 It is a schematic cross-sectional view of the air guiding transmission device in the present invention.

[0053] Figure 11 It is a three-dimensional structure schematic diagram of the support structure in the present invention.

[0054] Figure 12 It is a three-dimensional structure schematic diagram of the assembly of the detonation combustion device and the air guiding transmission device.

[0055] Figure 13 It is a front view of the assembly structure of the detonation combustion device and the air guiding transmission device.

[0056] Figure 14 The first detonation combustion device and the second detonation combustion device are in the filling and expansion stages respectively.

[0057] Figure 15 It is a schematic diagram of the principle that after the detonation wave in the first detonation combustion device propagates downstream through the air guiding hole, the high-pressure burned mixture behind the detonation wave enters the air guiding cylinder through the air guiding hole and pushes the air guiding transmission device to displace upstream, thereby driving the mechanical rotary valve to rotate.

[0058] Figure 16 It is a schematic diagram of the principle that the incoming flow path of the first detonation combustion device is cut off by the mechanical rotary valve, and the incoming flow path of the second detonation combustion device is gradually opened. The pressure relief hole of the air guiding cavity is displaced to the left side of the air guiding cylinder, the internal and external pressure difference decreases, and the air guiding transmission device starts to rebound under the action of the transmission spring, driving the mechanical rotary valve to rotate.

[0059] Figure 17 The first detonation combustion device is in the expansion stage, and the second detonation combustion device is in the filling stage. Subsequently, the second detonation combustion device is filled, the circumferentially arranged spark plug ignites and detonates, and enters the next cycle.

[0060] Explanation of reference numerals:

[0061] 1. Mechanical rotary valve, 11. Ring-shaped valve body, 12. Slide groove, 13. Connection structure, 14. Central bearing;

[0062] 2. Detonation combustion device, 21. Detonation tube, 22. Air guiding cylinder, 23. Fuel injector, 24. Spark plug, 25. First type of transmission rod support structure, 26. Second type of transmission rod support structure, 27. Ring-shaped disc, 28. Air guiding hole, 29. Sector window;

[0063] 3. Air guiding transmission device, 31. Transmission rod, 32. Air guiding cylinder sleeve, 33. Boss, 34. Slide pin box, 35. Air guiding cavity, 36. Pressure relief hole, 37. Circumferential fixing structure, 38. Support spring, 39. Slide pin, 310. Slide pin box cover;

[0064] 4. Support structure;

[0065] 5. Transmission spring. Specific implementation mode

[0066] The present invention will be further described below with reference to the accompanying drawings.

[0067] As Figure 1 , 2 shown, the pulse detonation combustor with an air guiding device proposed by the present invention includes an anti-backflow suppression mechanism, multiple groups of detonation combustion units and a support structure; the anti-backflow suppression mechanism includes a mechanical rotary valve 1, multiple air guiding transmission devices 3 and a transmission spring 5 for resetting the air guiding transmission device 3; each group of detonation combustion units includes multiple detonation combustion devices 2, the number of air guiding transmission devices 3 matches the total number of detonation combustion devices 2, each detonation combustion device 2 is correspondingly provided with an air guiding transmission device 3, and each air guiding transmission device 3 is driven by a part of the energy gas led out from its corresponding detonation combustion device 2; the output ends of all the air guiding transmission devices 3 are cooperatively connected with the mechanical rotary valve 1, and can drive the mechanical rotary valve 1 to rotate, so as to realize the opening and closing and opening degree control of the mechanical rotary valve 1, and further realize the connection and disconnection of multiple groups of detonation combustion units with the air inflow, and anti-backflow isolation.

[0068] As Figures 3 - 6 shown, the mechanical rotary valve 1 includes an annular valve body 11, a connection structure 13 and a central bearing 14 which are arranged from outside to inside in sequence. N holes 15 are formed on the end surface of the annular valve body 11 and are uniformly distributed along the same circumferential direction, and the number N of the holes 15 is equal to the number 1 / k of the detonation tubes 21 (k is an integer greater than 1 and less than 5); preferably, the holes 15 are round holes, and when they are round holes, the inner diameter of the holes 15 is equal to the inner diameter of the detonation tubes 21 in the detonation combustion device 2; a sliding groove 12 for cooperating with the sliding pins in the air guiding transmission device 3 is arranged on the inner ring inner wall surface of the annular valve body 11, and the sliding groove 12 extends in the form of a sine curve with a minimum period of 2π / kN, and the most downstream position of the sliding groove 12 (the trough of the sine curve) corresponds to the circumferential position of the opening, that is: if a trough of the sine curve corresponds to a hole 15, then the axis of the trough, the axis of the hole 15 and the axis of the annular valve body 11 are coplanar. In order to match the connection structure 13 and the detonation tubes 21 in the detonation combustion device 2, the inner ring side wall of the annular valve body 11 extends axially outward by a certain distance to provide enough installation surface for the connection structure 13, and the outer ring side wall of the annular valve body 11 extends axially outward by a certain distance to form a radial limiting surface for the detonation tubes 21. The connection structure 13 is used to connect the annular valve body 11 with the central bearing 14. The central bearing 14 is used to be fixed on the engine casing to ensure the axial position of the mechanical rotary valve 1 is fixed.

[0069] As Figures 7 - 8As shown, the detonation combustion device 2 is used to generate detonation waves. There are a total of kN detonation combustion devices, which are evenly distributed along the same circumference. A single detonation combustion device 2 includes a detonation tube 21, an air guide cylinder 22, a spark plug 24, an injector 23, and a transmission rod support structure; the inner diameter of the detonation tube 21 corresponds to the inner diameter of the hole 15 on the end face of the mechanical rotary valve 1, and the outer wall surface of the detonation tube 21 is matched and attached to the axial extension section of the outer ring side wall of the annular valve body 11 in the mechanical rotary valve 1. An air guide cylinder 22, a spark plug 24, an injector 23, and a transmission rod support structure are arranged on the side wall of each detonation tube 21. Among them, the spark plug 24 and the injector 23 are located at the end of the detonation tube 21 closer to the mechanical rotary valve 1, and the air guide cylinder 22 is located in the middle of the detonation tube 21 and the distance from the spark plug 24 is greater than or equal to 300 mm and less than or equal to 400 mm, which can further improve the working reliability of the air guide transmission device 3 on the premise of ensuring the generation of stable detonation waves. The air guide cylinder 22 is connected to the inner cavity of the detonation tube 21 through an air guide hole 28, and the spark plug 24 is located between the injector 23 and the air guide cylinder 22 (that is, the spark plug 24 is located downstream of the injector 23). A ring-shaped disc 27 is installed in the middle of the air guide cylinder 22, and a plurality of fan-shaped windows 29 are evenly arranged on the end face of the ring-shaped disc 27; when working in cooperation with the air guide transmission device 3, the circumferential fixing structure at the right end of the air guide transmission device 3 is matched with the air guide cylinder 22 through the fan-shaped windows 29 on the ring-shaped disc 27. There are two types of transmission rod support structures: the first type of transmission rod support structure 25 is installed in the area of the end side wall of the detonation tube 21 close to the air guide cylinder 22, and only plays the role of supporting the transmission rod 31 in the air guide transmission device, and can reduce friction by reducing the contact area with the transmission rod 31; the second type of transmission rod support structure 26 is installed in the area of the end side wall of the detonation tube 21 closer to the mechanical rotary valve 1, and simultaneously plays the role of supporting the transmission rod 31 in the air guide transmission device 3 and fixing the transmission spring 5.

[0070] As Figure 1 , 9 -10 shows, the number of the air guide transmission devices 3 corresponds to the detonation combustion devices 2, and each detonation combustion device 2 is matched with an air guide transmission device 3. A single air guide transmission device 3 includes a sliding pin box 34, a transmission rod 31, and an air guide cylinder sleeve 32 that are connected in sequence. The transmission rod 31 is a straight rod with a constant diameter, and a boss 33 is arranged in the middle of the transmission rod 31 to play the role of fixing the transmission spring 5 when the air guide transmission device 3 works in cooperation with the detonation combustion device 2. The air guide cylinder sleeve 32 is composed of an air guide cavity 35, a pressure relief hole 36, and a circumferential fixing structure 37; the inner diameter of the air guide cavity 35 matches the outer diameter of the air guide cylinder 22 in the detonation combustion device 2, and the circumferential fixing structure 37 at its right end is matched and installed with the fan-shaped windows 29 on the end face of the ring-shaped disc 27 on the air guide cylinder 22; there are a plurality of pressure relief holes 36, which are evenly arranged along the circumferential direction on the side wall of the air guide cylinder sleeve 32 and communicate with the air guide cavity 35. As Figure 12 , 13As shown, after the air guide transmission device 3 is assembled with the knock combustion device 2 and the transmission spring 5, the air guide cylinder 22 in the knock combustion device 2 is inserted into the air guide cavity 35 in the air guide transmission device 3 and blocks the pressure relief hole on the side wall of the air guide cavity 35. The air guide cavity 35 in the air guide transmission device 3 is communicated with the inner cavity of the knock tube 21 (i.e., communicated with the knock chamber) through the air guide cylinder 22 in the knock combustion device 2. The transmission rod 31 in the air guide transmission device 3 is supported by the transmission rod support structure on the side wall of the knock tube 21 in the knock combustion device 2. The transmission spring 5 is limited by the boss 33 in the middle of the transmission rod 31 in the air guide transmission device 3 and one of the transmission rod support structures on the side wall of the knock tube 21. The sliding pin box 34 is composed of a sliding pin 39, a support spring 38 and an outer cover 310 of the sliding pin box. The sliding pin 39 is a cylinder with a diameter matching the width of the sliding groove 12 on the inner wall of the inner ring of the annular valve body 11 in the mechanical rotary valve 1. The sliding pin 39 is installed at the central position of the outer cover 310 of the sliding pin box and the end extends out of the outer cover 310 of the sliding pin box. The support spring 38 is installed in the outer cover 310 of the sliding pin box and is located at the bottom of the sliding pin 39 to apply pressure to it, ensuring that the sliding pin 39 is always in close contact with the sliding groove 12 of the mechanical rotary valve 1, ensuring the working reliability of the mechanical rotary valve. When the air guide transmission device 3 and the mechanical rotary valve 1 cooperate to work, the sliding pin 39 slides in the sliding groove 12 of the mechanical rotary valve 1, thereby driving the mechanical rotary valve 1 to rotate, and converting the axial reciprocating motion of the air guide transmission device 3 into the circumferential rotational motion of the mechanical rotary valve 1 through the cooperation of the sliding pin 39 and the sliding groove 12.

[0071] As Figure 1 , 11 shown, there are at least 3 support structures 4, which are arranged in parallel and installed on the engine casing for fixing and restricting the knock tube 21 in the knock combustion device 2.

[0072] The principle of the present invention is:

[0073] Define the oncoming flow direction as the upstream. Most of the energy of the shock wave generated by the knock combustion device 2 propagates downstream through the cavity of the knock tube itself to generate thrust, and the remaining energy enters the air guide cavity 35 of the air guide cylinder sleeve 32 in the air guide transmission device 3 through the air guide cylinder 22 on the side wall of the knock tube 21, pushing the transmission rod 31 to move axially, further driving the sliding pin 39 on the sliding pin box 34 to slide along the sliding groove 12 of the mechanical rotary valve 1, thereby driving the mechanical rotary valve 1 to rotate, realizing the adaptive control of the opening and closing and the opening degree of the mechanical rotary valve 1, and finally realizing the reverse transmission isolation of the knock chamber and the adaptive filling of the knock chamber through the adaptive adjustment of the mechanical rotary valve 1.

[0074] As Figure 14As shown, at this moment, two adjacent detonation combustion devices are respectively in the filling (the first detonation combustion device) and expansion (the second detonation combustion device) stages. At a subsequent moment, the spark plug 24 circumferentially arranged in the first detonation combustion device ignites, and a stable detonation wave is formed at a certain distance downstream of the spark plug 24 and propagates towards the outlet of the detonation chamber. Since there is no combustible mixture distribution upstream of the fuel injector 23, the detonation wave degenerates into a reverse wave without chemical reaction and propagates upstream in the upstream direction of the fuel injector 23.

[0075] As Figure 15 shown, after the detonation wave in the first detonation combustion device propagates downstream and passes through the air guide hole 28 on the side wall of its detonation tube 21, the high-pressure burned mixture after the detonation wave enters the air guide cylinder 22 through the air guide hole 28 and pushes the corresponding air guide transmission device 3 to displace upstream. The sliding pin 39 of the air guide transmission device 3 moves along the sliding groove 12 of the mechanical rotary valve 1, thereby converting the axial displacement of the air guide transmission device 3 into the circumferential displacement of the mechanical rotary valve 1 and driving the mechanical rotary valve 1 to rotate. At the same time, the reverse wave in the first detonation combustion device propagates upstream at a propagation speed much lower than that of the detonation wave, and the adjacent second detonation combustion device is still in the expansion stage. As the high-pressure burned mixture after the wave in the first detonation combustion device continuously enters the air guide cylinder 22, the air guide transmission device 3 continuously displaces upstream, and the transmission spring 5 between the boss 33 on the transmission rod 31 in the air guide transmission device 3 and the transmission rod support structure of the detonation combustion device 2 is gradually compressed.

[0076] Driven by the sliding pin 39 in the air guide transmission device 3 corresponding to the first detonation combustion device, the mechanical rotary valve 1 gradually rotates to the position as Figure 16 shown. At this time, the detonation tube 21 of the first detonation combustion device is not connected to the hole 15 on the end face of the mechanical rotary valve 1, and its incoming flow path is cut off by the mechanical rotary valve 1, realizing the isolation of the reverse wave. At the same time, the detonation tube 21 of the second detonation combustion device is connected to one of the holes 15 on the end face of the mechanical rotary valve 1, and its incoming flow path is gradually opened, and the second detonation combustion device enters the exhaust stage. At this time, the pressure relief hole 36 on the air guide cavity 35 of the air guide transmission device 3 corresponding to the second detonation combustion device is displaced to the left side of the air guide cylinder 22 in the second detonation combustion device, and the high-pressure gas in the air guide cavity 35 and the air guide cylinder 22 is released, and the internal and external pressure difference decreases. The air guide transmission device 3 corresponding to the second detonation combustion device starts to rebound to the initial position under the action of the transmission spring 5, and the sliding pin 9 moves relative to the sliding groove 12 of the mechanical rotary valve 1, thereby driving the mechanical rotary valve 1 to rotate.

[0077] When the mechanical rotary valve 1 gradually rotates to the position as Figure 17When in the shown position, the air guiding transmission device 3 corresponding to the second detonation combustion device rebounds to the initial position at this time. The first detonation combustion device is in the expansion stage, and the second detonation combustion device is in the filling stage. Subsequently, after the filling of the second detonation combustion device is completed, the circumferentially arranged spark plug 24 ignites and detonates, entering the next cycle.

Claims

1. An anti-backflow suppression mechanism is used to prevent pressure and gas from flowing back to the intake duct or compressor of a pulse detonation engine. The anti-backflow suppression mechanism includes a mechanical rotary valve, and the mechanical rotary valve is used to connect and cut off each detonation combustion unit in the pulse detonation engine with the air flow. Each detonation combustion unit includes a plurality of detonation combustion devices. It is characterized in that: The anti-backflow suppression mechanism further includes a gas guiding transmission device whose quantity matches the total quantity of the detonation combustion devices in the pulse detonation engine, and a transmission spring for making it rebound and reset when the gas guiding transmission device relieves pressure. Each gas guiding transmission device is driven by a part of the energy gas led out from its corresponding detonation combustion device, compresses the transmission spring and generates an axial displacement. The output ends of all the gas guiding transmission devices are cooperatively connected with the mechanical rotary valve, and can convert their axial displacements into the circumferential rotation of the mechanical rotary valve, driving its opening and closing and opening degree control.

2. The anti-feedback suppression mechanism according to claim 1, wherein: The detonation combustion device includes a detonation tube, a spark plug, an injector and a gas guiding cylinder arranged on the detonation tube. The gas guiding transmission device takes a part of the energy gas from the detonation tube through the gas guiding cylinder as the driving gas.

3. The anti-feedback suppression mechanism according to claim 2, characterized in that: The distance between the gas guiding cylinder and the spark plug is greater than or equal to 300 mm and less than or equal to 400 mm.

4. A pulse detonation combustion chamber with a gas guiding device includes an anti-backflow suppression mechanism, multiple groups of detonation combustion units and a support structure. The anti-backflow suppression mechanism includes a mechanical rotary valve, and the mechanical rotary valve is used to connect and cut off the detonation combustion unit with the air flow. Each group of detonation combustion units includes a plurality of detonation combustion devices for generating detonation waves. The support structure is used to fixedly constrain the multiple groups of detonation combustion units on the engine. It is characterized in that: The anti-backflow suppression mechanism further includes a gas guiding transmission device whose quantity matches the total quantity of the detonation combustion devices, and a transmission spring for making it rebound and reset when the gas guiding transmission device relieves pressure. Each gas guiding transmission device is driven by a part of the energy gas led out from its corresponding detonation combustion device, compresses the transmission spring and generates an axial displacement. The output ends of all the gas guiding transmission devices are cooperatively connected with the mechanical rotary valve, and can convert their axial displacements into the circumferential rotation of the mechanical rotary valve, driving its opening and closing and opening degree control.

5. The pulse detonation combustor with an air guiding device according to claim 4, characterized in that: The detonation combustion device includes a detonation tube, a spark plug, an injector and a gas guiding cylinder. The output end of the gas guiding cylinder is connected with the gas guiding transmission device, and is used to lead out a part of the energy gas from the detonation tube to drive the gas guiding transmission device to act.

6. The pulse detonation combustor with an air guiding device according to claim 5, characterized in that: The distance between the gas guiding cylinder and the spark plug is greater than or equal to 300 mm and less than or equal to 400 mm.

7. The pulse detonation combustion chamber with a gas guiding device according to claim 5 or 6, characterized in that: The mechanical rotary valve includes an annular valve body, a connection structure, and a central bearing arranged in sequence from outside to inside; N holes are provided on the end face of the annular valve body, which are evenly distributed along the same circumference. The inner diameter of the holes matches the inner diameter of the detonation tube of the detonation combustion device. The number N of the holes is 1 / k of the total number of detonation combustion devices, where k is an integer greater than 1 and less than 5, and N is an integer greater than or equal to 2; a chute is provided on the inner ring inner wall surface of the annular valve body; the chute extends in the form of a sine curve with a minimum period of 2π / kN. If the trough of the sine curve corresponds to the hole, the trough, the axis of the hole, and the axis of the annular valve body are coplanar. Each gas guiding transmission device includes a sliding pin box, a transmission rod, and a gas guiding cylinder sleeve connected in sequence; the sliding pin box consists of a sliding pin, a supporting spring, and an outer cover of the sliding pin box. The sliding pin is installed in the middle of the outer cover of the sliding pin box and extends out of the outer cover of the sliding pin box. The sliding pin is used to cooperate with the chute on the mechanical rotary valve for transmission. The supporting spring is installed inside the outer cover of the sliding pin box and is located at the bottom of the sliding pin to apply pressure to it so that the sliding pin always keeps in close contact with the chute; a boss is provided in the middle of the transmission rod for limiting the transmission spring; the gas guiding cylinder sleeve includes a gas guiding cavity and a circumferential fixing structure. A plurality of pressure relief holes are evenly distributed along the circumferential direction on the side wall of the gas guiding cavity; the circumferential fixing structure has a plurality of insertion posts. A ring-shaped disc with a plurality of clamping windows on its end face is sleeved in the middle of the gas guiding cylinder. The insertion posts of the circumferential fixing structure are in one-to-one correspondence with the clamping windows of the ring-shaped disc to achieve insertion connection, connecting the gas guiding cavity with the gas guiding cylinder. Two types of transmission rod support structures are provided on the side wall of the detonation tube. The first type of transmission rod support structure is located on the end side wall of the detonation tube and in the area close to the gas guiding cylinder, and is only used to support the transmission rod in the gas guiding transmission device; the second type of transmission rod support structure is located on the end side wall of the detonation tube and in the area close to the mechanical rotary valve, and is used to support the transmission rod in the gas guiding transmission device and to limit the transmission spring. The transmission spring is sleeved on the transmission rod, and the two ends are respectively limited by the boss and the second type of transmission rod support structure.

8. The pulse detonation combustor with an air guiding device according to claim 7, characterized in that: The inner ring side wall of the annular valve body extends axially outward by a certain distance to provide enough installation surface for the connection structure, and the outer ring side wall of the annular valve body extends axially outward by a certain distance to form a radial limiting surface for the detonation tube.

9. The pulse detonation combustor with an air guiding device according to claim 7, characterized in that: The holes on the end face of the annular valve body are round holes.

10. An air-breathing pulse detonation engine, comprising a pulse detonation combustor; characterized in that: The pulse detonation combustion chamber adopts the pulse detonation combustion chamber with a gas guiding device according to any one of claims 4-9.

Images