A secondary powder starter

Abstract

The application discloses a secondary firecracker starter, which comprises a total casing and a nozzle seat, the total casing and the nozzle seat are connected through a flange structure and a combustion chamber is formed in the total casing and the nozzle seat; the flange structure comprises a first flange arranged on an end face of the total casing and a second flange arranged on an end face of the nozzle seat, and the first flange and the second flange are fixed through fastening bolts; the temperature rise in the firecracker starter is controlled through the water vaporization in the ring cavity of the nozzle seat to take away heat and the radiation heat transfer of the flange structure of the total casing and the nozzle seat, and the technical problem that the secondary firecracker starter cannot isolate high-temperature and high-pressure gas to cause the secondary firecracker starter to burn earlier than the predetermined time in the first starting and working process of a liquid rocket engine is avoided, and the technical problem that the manufacturing and installation process of the heat insulation structure in the existing secondary starting firecracker starter is complex, the falling probability is high, the cost of the starter is high, and the reliability is low is solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of liquid rocket engines, and relates to a powder starter, in particular to a secondary powder starter. BACKGROUND

[0002] The secondary starting of a liquid rocket engine is one of the key technologies of a recoverable liquid carrier rocket. The current technical approach is to provide two powder starters for the liquid rocket engine, which are respectively used for the primary starting and the secondary starting of the engine. The two powder starters are physically installed in parallel and work in series in time sequence. The powder starter used for the primary starting of the liquid rocket engine works, and high-temperature and high-pressure gas is generated in the working process of the liquid rocket engine. The high-temperature and high-pressure gas is applied to the secondary powder starter for the engine throughout the process.

[0003] In order to ensure that the secondary powder starter can withstand the above harsh gas environment and reliably ignite itself, an isolation device needs to be designed and heat insulation measures need to be taken. A Chinese invention patent with the authorization announcement number CN 114439648 B discloses a secondary powder starter for an engine. The invention partially isolates the high-temperature gas from the outside from being conducted to the total casing through the nozzle seat by setting a heat insulation pad between the flanges of the total casing and the nozzle seat; and the first heat insulation layer and the second heat insulation layer are respectively set on the inner walls of the total casing and the nozzle seat, so as to ensure that the temperature in the casing is below the combustible temperature of the propellant column. The above measures can effectively isolate heat, but there are the following problems: first, the cost is high. Since the heat insulation pad, the first heat insulation layer and the second heat insulation layer are made of high-temperature-resistant materials, the manufacturing and installation process is complex, resulting in high cost and poor economic affordability; second, the first heat insulation layer and the second heat insulation layer are adhered to the inner walls of the total casing and the nozzle seat by an adhesive. The quality of the adhesive itself and the quality of the coating construction will affect the adhesion quality of the heat insulation layer to the casing and the nozzle seat. The probability of the first heat insulation layer and the second heat insulation layer falling off is high. Once the heat insulation layer falls off, the heat insulation function will be lost, and the reliability of heat insulation will be affected. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the present application is to provide a secondary powder starter to solve the technical problems of the prior art, such as the complex manufacturing and installation process of the heat insulation structure, the high probability of falling off, the high cost of the starter and the low reliability.

[0005] In order to solve the above technical problems, the present application adopts the following technical solutions:

[0006] A secondary powder starter, comprising a total casing and a nozzle seat, the total casing and the nozzle seat are connected through a flange structure and form a combustion chamber inside;

[0007] The flange structure comprises a first flange arranged on the end face of the total casing and a second flange arranged on the end face of the nozzle seat, the first flange and the second flange are fixed by fastening bolts; there is a gap between the first flange and the second flange, and a matched groove and a tenon are arranged on the end faces of the first flange and the second flange respectively, and a second sealing ring is further arranged between the tenon and the groove;

[0008] The axial front end of the total casing is provided with an electric igniter; the ignition support and the propellant blocking plate are arranged in the combustion chamber in sequence along the axial direction, and the ignition support and the propellant blocking plate divide the combustion chamber into a first cavity, a second cavity and a third cavity; the ignition support is provided with an ignition charge box in the first cavity, and the propellant blocking plate is provided with a main charge in the second cavity;

[0009] The nozzle seat comprises a nozzle seat shell and a nozzle seat inner cone shell, an annular cavity is formed between the nozzle seat shell and the nozzle seat inner cone shell, and water is arranged in the annular cavity; an air vent is arranged on the nozzle seat shell, and a rubber plug is arranged in the air vent; a nozzle is arranged in the nozzle seat, one end of the nozzle is communicated with the third cavity, the other end of the nozzle is provided with a gas diaphragm assembly fixed on the inner wall of the nozzle seat, and an outlet flange of the nozzle seat is arranged at the axial rear end of the nozzle seat.

[0010] The application also comprises the following technical features:

[0011] The rubber plug is in the shape of a circular truncated cone, and the end face with a smaller diameter is close to the annular cavity.

[0012] A first sealing ring is arranged between the total casing and the electric igniter.

[0013] A buffer pad is arranged between the ignition support and the main charge.

[0014] An elastic pad is arranged between the main charge and the propellant blocking plate.

[0015] The gas diaphragm assembly comprises a baffle and a diaphragm arranged in sequence along the axial direction.

[0016] The diaphragm is provided with a notch in the shape of a "Wen" character on the side close to the outlet of the nozzle seat.

[0017] The baffle and the diaphragm are both in the shape of a "concave" character.

[0018] A plurality of through holes are arranged on the baffle.

[0019] Compared with the prior art, the application has the beneficial technical effects that:

[0020] (I) In the present application, the temperature rise in the internal of the fire starter is controlled by the water vaporization in the ring cavity of the nozzle seat to take away heat and the radiation heat transfer of the flange structure between the total casing and the nozzle seat, and the technical problem that the secondary fire starter burns earlier than the scheduled time in the first starting and working process of the liquid rocket engine due to the failure to isolate the high-temperature and high-pressure combustion gas is avoided, and the technical problem that the manufacturing and installation process of the heat insulation structure in the existing secondary fire starter is complex, the probability of falling off is high, the cost of the starter is high, and the reliability is low is solved.

[0021] (II) In the present application, the flange structure connection between the total casing and the nozzle seat is changed from the contact connection in the prior art to the gap connection, and correspondingly, the heat transfer mode between the flanges is changed from the conduction heat transfer in the prior art to the radiation heat transfer, which significantly reduces the heat transfer efficiency; at the same time, due to the existence of the gap, the end surface of the first flange is fully open, which increases the channel for external radiation heat transfer while absorbing heat, greatly reducing the heat transfer between the casing and the nozzle seat.

[0022] (III) In the present application, the ring cavity is arranged on the nozzle seat, and the water in the ring cavity absorbs a large amount of heat by evaporation, vaporization, sublimation and the like, so that the heat transferred by the nozzle seat outlet flange is carried away from the fire starter in time through the air holes on the nozzle seat shell with steam as the carrier, which on the one hand prevents the temperature rise of the nozzle seat itself, reduces the temperature difference between the nozzle seat and the total casing, and greatly reduces the heat continuously transferred to the total casing; on the other hand, the steam takes away heat, which reduces the total heat value that promotes the temperature rise of the fire starter, and ensures the total temperature rise limit of the fire starter.

[0023] (IV) Compared with the prior art, the functional parts such as the heat insulation pad, the first heat insulation layer and the second heat insulation layer are omitted in the present application, which on the one hand greatly reduces the product cost, and on the other hand makes the structure simple and the reliability higher. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the present application;

[0025] Figure 2 It is a schematic diagram of the connection gap between the total casing and the nozzle seat in the present application;

[0026] Figure 3 It is a schematic diagram of the cross-sectional structure of the nozzle seat in the present application;

[0027] Figure 4 It is a schematic diagram of the overall structure of the baffle in the present application;

[0028] Figure 5 It is a schematic diagram of the cross-sectional structure of the baffle in the present application;

[0029] Figure 6The assembly structure diagram of the diaphragm and the baffle in the application is shown in the figure.

[0030] Figure 7 The assembly structure diagram of the diaphragm, the baffle and the nozzle seat in the application is shown in the figure.

[0031] Figure 8 The structure diagram of the diaphragm in the application is shown in the figure.

[0032] Figure 9 The structure diagram of the rubber plug in the application is shown in the figure.

[0033] The meanings of the respective numbers in the figure are as follows: the total shell 1, the nozzle seat 2, the combustion chamber 3, the first flange 4, the second flange 5, the fastening bolt 6, the electric igniter 7, the ignition support 8, the baffle 9, the main charge 10, the nozzle 11, the gas diaphragm assembly 12, the second sealing ring 13, the buffer pad 14, the elastic pad 15, the ignition powder box 16, the nozzle seat outlet flange 17, the through hole 18, the groove 19, the tenon 20.

[0034] The nozzle seat shell 201, the nozzle seat inner conical shell 202, the ring cavity 203, the air hole 204, the rubber plug 205.

[0035] The first cavity 301, the second cavity 302, the third cavity 303.

[0036] The baffle 1201, the diaphragm 1202.

[0037] The specific content of the application is further explained and described in detail in the following combined with the embodiments. DETAILED DESCRIPTION

[0038] It should be noted that all the parts in the application, without special description, adopt the parts known in the art.

[0039] The specific embodiments of the application are given below, and it should be noted that the application is not limited to the following specific embodiments, and any equivalent transformation made on the basis of the technical solutions of the application falls within the protection scope of the application.

[0040] The application gives a secondary powder starter, as shown in the figure, which comprises a total shell 1 and a nozzle seat 2, and the total shell 1 and the nozzle seat 2 are connected through a flange structure and form a combustion chamber 3 inside. Figures 1 to 9

[0041] The flange structure comprises a first flange 4 arranged on the end face of the total shell 1 and a second flange 5 arranged on the end face of the nozzle seat 2, and the first flange 4 and the second flange 5 are fixed through a fastening bolt 6; there is a gap between the first flange 4 and the second flange 5, and a groove 19 and a tenon 20 matched with each other are arranged on the end faces of the first flange 4 and the second flange 5 respectively, and a second sealing ring 13 is further arranged between the tenon 19 and the groove 20. ​

[0042] The axial front end of the total shell 1 is provided with an electric igniter 7; the ignition support 8 and the propellant blocking plate 9 are sequentially arranged in the axial direction in the combustion chamber 3, and the ignition support 8 and the propellant blocking plate 9 divide the combustion chamber 3 into a first cavity 301, a second cavity 302 and a third cavity 303; the ignition support 8 is provided with an ignition charge box 16 in the first cavity 301, and the main charge 10 is arranged in the second cavity 302;

[0043] The nozzle seat 2 comprises a nozzle seat outer shell 201 and a nozzle seat inner cone shell 202, and an annular cavity 203 is formed between the nozzle seat outer shell 201 and the nozzle seat inner cone shell 202, and water is arranged in the annular cavity 203; the nozzle seat outer shell 201 is provided with a vent hole 204, and a rubber plug 205 is arranged in the vent hole 204; the nozzle seat 2 is provided with a nozzle 11 which is in communication with the third cavity 303 at one end, and the other end of the nozzle 11 is provided with a gas diaphragm assembly 12 which is fixed to the inner wall of the nozzle seat 2, and the axial rear end of the nozzle seat 2 is provided with a nozzle seat outlet flange 17.

[0044] In the above technical solution, when the secondary propellant starter does not need to be ignited, the high-temperature and high-pressure gas generated during the working process of the primary propellant starter of the liquid rocket engine and the working process of the liquid rocket engine is applied to the secondary propellant starter for the engine, and specifically acts on the nozzle seat outlet flange 17 and the gas diaphragm assembly 12.

[0045] Heat insulation principle: the heat brought by the gas is conducted to the nozzle seat 2 and the gas diaphragm assembly 12, and as the conducted heat increases, the temperature of the nozzle seat 2 and the gas diaphragm assembly 12 increases, and then: approach one: the gas diaphragm assembly 12 heats the surrounding air, and conducts heat to the combustion chamber 3 in a convection manner (very small); approach two: the nozzle seat 3 conducts heat to the water, and the temperature of the water slowly increases, and starts to evaporate, vaporize and sublimate, and the pressure of the cavity increases, when the temperature increases to boiling or higher, the rubber plug 205 in the vent hole 204 is ejected under the action of the pressure, and the water vapor is also ejected, thereby limiting the increase of the temperature of the nozzle seat 2. In addition, a small part of the heat continues to be conducted along the nozzle seat 2 to the second flange 5 of the nozzle seat, causing the temperature of the second flange 5 to increase, and since the amount of heat is small, the temperature rise is not high, and the temperature difference between the second flange 5 and the first flange 4 is not large, and since the heat transfer between the two is radiation, the heat transfer is small, and the temperature rise of the total shell is smaller.

[0046] When the secondary propellant starter needs to be ignited: the electric igniter 7 is electrified to ignite, igniting the ignition cartridge 16, which burns to generate fuel gas. Under the sealing effect of the fuel gas diaphragm assembly 12, the pressure continuously increases. When the pressure value meets the critical pressure value of the main charge 10, the main charge 10 is ignited, and the pressure in the combustion chamber 3 further increases to a certain value, at which point the fuel gas diaphragm assembly 12 is broken, and the fuel gas is ejected from the outlet of the nozzle 11 to do work.

[0047] In summary, by means of water vaporization in the annular cavity 203 of the nozzle seat 2 to take away heat and radiation heat transfer between the flange structure of the total casing 1 and the nozzle seat 2, the increase in the internal temperature of the propellant starter is controlled, and the technical problem of early combustion of the secondary propellant starter in the liquid rocket engine during the first start and work process is avoided. The technical problems of complex manufacturing and installation process, high probability of falling off, high cost, and low reliability of the existing secondary propellant starter are solved.

[0048] In the present scheme, the flange structure connection between the total casing and the nozzle seat changes from contact connection in the prior art to gap connection. Correspondingly, the heat transfer mode between the flanges changes from conduction heat transfer in the prior art to radiation heat transfer, which significantly reduces the heat transfer efficiency. At the same time, due to the existence of the gap, the end face of the first flange is fully open, which increases the channel for external radiation heat transfer while absorbing heat, greatly reducing the heat transfer between the casing and the nozzle seat.

[0049] In the present scheme, the annular cavity is provided on the nozzle seat, and the water in the annular cavity absorbs a large amount of heat through evaporation, vaporization, sublimation, etc. The heat transferred by the nozzle seat outlet flange is carried away from the propellant starter in the form of steam through the air holes on the nozzle seat shell, which prevents the temperature of the nozzle seat from rising, reduces the temperature difference between the nozzle seat and the total casing, and greatly reduces the heat transferred to the total casing. On the other hand, the steam takes away heat, which reduces the total heat value that promotes the temperature rise of the propellant starter, and ensures the overall temperature rise limit of the propellant starter.

[0050] Specifically, the rubber plug 205 is a circular truncated cone, and the end face with a smaller diameter is close to the annular cavity 203.

[0051] In the above technical scheme, the circular truncated rubber plug 205 is convenient to install.

[0052] Specifically, a first sealing ring is arranged between the total casing 1 and the electric igniter 7.

[0053] In the above technical scheme, the first sealing ring can realize reliable sealing between the electric igniter 3 and the total casing 101. The first sealing ring and the second sealing ring are made of flexible graphite material or soft metal material, and the soft metal material includes but is not limited to aluminum and copper.

[0054] Specifically, the ignition bracket 8 and the main charge 10 are provided with a buffer pad 14.

[0055] In the above technical solution, the buffer pad 14 can compensate for the deformation mismatch of each component caused by the change of the ambient temperature, and is generally made of elastic non-metallic material, such as aviation sponge rubber material.

[0056] Specifically, the main charge 10 and the baffle plate 9 are provided with an elastic pad 15.

[0057] In the above technical solution, the elastic pad 15 is used to buffer the vibration, shock and impact load between the charge 10 and the baffle plate 8, and the buffer pad is generally made of elastic non-metallic material, such as aviation sponge rubber material.

[0058] Specifically, the gas diaphragm assembly 12 includes a baffle 1201 and a diaphragm 1202 arranged in sequence along the axial direction.

[0059] Specifically, the diaphragm 1202 is provided with a notch engraved with a "W" shape on the side close to the outlet of the nozzle seat 2, which ensures that the diaphragm can be more easily broken by the combustion chamber gas.

[0060] Specifically, the baffle 1201 and the diaphragm 1202 are both "concave" shapes, which ensures that the diaphragm will not fall apart when it is broken, avoiding damage to downstream components.

[0061] Specifically, the baffle 1201 is provided with a plurality of through holes 18.

[0062] In the above technical solution, the gas diaphragm assembly 12 makes the effective area of the diaphragm 1202 different by providing a plurality of through holes 18 on the baffle 1201, so that the gas generated by the liquid rocket engine during the first start and work will not break the diaphragm and enter the combustion chamber 3, while the gas generated by the charge during the second start of the liquid rocket engine can reliably open the diaphragm 1202 and be ejected from the nozzle 11 to do work.

Claims

1. A secondary powder starter comprising a general casing (1) and a nozzle seat (2), characterized in that, The total casing (1) and the nozzle seat (2) are connected by a flange structure and form a combustion chamber (3) inside. The flange structure comprises a first flange (4) arranged on the end face of the total casing (1) and a second flange (5) arranged on the end face of the nozzle seat (2), the first flange (4) and the second flange (5) are fixed by fastening bolts (6); there is a gap between the first flange (4) and the second flange (5) and a matching groove (19) and a tenon (20) are arranged on the end faces of the first flange (4) and the second flange (5) respectively, and a second sealing ring (13) is further arranged between the tenon (20) and the groove (19). An electric igniter (7) is arranged on the axial front end of the total casing (1); an ignition support (8) and a propellant blocking plate (9) are arranged in the combustion chamber (3) in sequence along the axial direction, the ignition support (8) and the propellant blocking plate (9) divide the combustion chamber (3) into a first cavity (301), a second cavity (302) and a third cavity (303), an ignition propellant box (16) is arranged in the first cavity (301), and a main charge (10) is arranged in the second cavity (302). The nozzle seat (2) comprises a nozzle seat shell (201) and a nozzle seat inner conical shell (202), an annular cavity (203) is formed between the nozzle seat shell (201) and the nozzle seat inner conical shell (202), and water is arranged in the annular cavity (203); an air vent (204) is arranged on the nozzle seat shell (201), a rubber plug (205) is arranged in the air vent (204); a nozzle (11) is arranged in the nozzle seat (2) and one end of the nozzle (11) communicates with the third cavity (303), the other end of the nozzle (11) is provided with a gas diaphragm assembly (12) fixed on the inner wall of the nozzle seat (2); a nozzle seat outlet flange (17) is arranged on the axial rear end of the nozzle seat (2).

2. The secondary powder initiator of claim 1 wherein, The rubber plug (205) is in the shape of a circular truncated cone, and the end face with a smaller diameter is close to the annular cavity (203).

3. The secondary powder initiator of claim 1 wherein, A first sealing ring is arranged between the total casing (1) and the electric igniter (7).

4. The secondary powder initiator of claim 1 wherein, A buffer pad (14) is arranged between the ignition support (8) and the main charge (10).

5. The secondary powder initiator of claim 1 wherein, An elastic pad (15) is arranged between the main charge (10) and the propellant blocking plate (9).

6. The secondary powder initiator of claim 1 wherein, The gas diaphragm assembly (12) comprises a baffle (1201) and a diaphragm (1202) arranged in sequence along the axial direction.

7. The secondary powder initiator of claim 6 wherein, An "m" shaped notch is arranged on one side of the diaphragm (1202) close to the outlet of the nozzle seat (2).

8. The secondary powder initiator of claim 6 wherein, The baffle (1201) and the diaphragm (1202) are both in the shape of a "concave" character.

9. The secondary propellant starter according to claim 6, a plurality of through holes (18) are arranged on the baffle (1201).

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