A device and method for reducing the degree of slow cook-off response of a solid motor

Abstract

The present application relates to the technical field of slow cook-off of solid rocket engine, and particularly relates to a device and method for reducing the response degree of slow cook-off of solid rocket engine, which comprises a device body, a wireless control module, an ignition element, a medicine groove, low-temperature ignition medicine, a safety agent and a sealing material, the device body comprises a sealed upper chamber and a lower chamber with an open bottom, the wireless control module is located in the sealed upper chamber and used for controlling the on and off of the circuit, the medicine groove is located in the lower chamber, the low-temperature ignition medicine is fixed in the medicine groove and an opening is arranged at the bottom of the medicine groove, the sealing material is used for sealing the opening at the bottom of the lower chamber, the ignition element is embedded in the low-temperature ignition medicine and the sealing material and connected with the wireless control module, and the safety agent is located at the periphery of the medicine groove in the lower chamber. The device has simple principle, is convenient to make and use, does not affect the normal use function of the solid rocket engine, and can greatly reduce the violent degree of the slow cook-off response of the solid rocket engine.

Description

Technical Field

[0001] This invention relates to the field of solid rocket motor slow combustion technology, specifically to an apparatus and method for reducing the slow combustion response of a solid rocket motor. Background Technology

[0002] Solid-propellant engines are the power source for rockets and missiles. During transportation, storage, maintenance, and use, solid-propellant engines may encounter various external stimuli, among which thermal stimulation is one of the most common stimuli throughout their entire life cycle. Slow-burn testing is considered the most difficult thermal safety test for solid-propellant engines to pass. US military standards such as MIL-STD-2105D and QJ20152-2012 require that solid-propellant engines not exhibit a response exceeding the level of combustion during slow-burn testing. Currently, the severe slow-burn response of solid-propellant engines restricts the application of numerous weapons systems in harsh environments such as shipborne and airborne operations, attracting widespread attention from various research institutions.

[0003] Current research indicates that ammonium perchlorate, the main oxidizer in solid propellants, forms numerous porous structures under slow combustion, such as... Figure 1 As shown, this structure dramatically increases the propellant's combustion surface area, leading to violent combustion during slow burn-out responses, often resulting in explosions or more severe reactions. Currently, almost all composite solid propellants use ammonium perchlorate as the primary oxidizer, but technologies to reduce the intensity of slow burn-out responses are severely lacking. Foreign reports suggest prefabricating weak pressure relief grooves on the solid rocket motor casing to release some pressure during reactions, thus reducing their intensity. Domestically, Beijing Institute of Technology adds 1%–5% additives to the propellant, using the melted additives to form a protective film and reduce the response intensity. However, these methods all negatively impact the performance of solid rocket motors to some extent, hindering large-scale engineering applications. Summary of the Invention

[0004] To address the aforementioned problems, the first objective of this invention is to provide a device for reducing the degree of slow combustion response of a solid rocket motor. This device is simple in principle, easy to manufacture and use, does not affect the normal operation of the solid rocket motor, and can significantly reduce the severity of the slow combustion response of the solid rocket motor.

[0005] The second objective of this invention is to provide a method for reducing the slow-burn response of a solid rocket motor. This method involves placing a device for reducing the slow-burn response of a solid rocket motor at the head of the motor. When the solid rocket motor is subjected to slow-burn heat stimulation, the solid rocket motor is ignited before the propellant inside it generates a large number of porous combustion surfaces, thereby significantly reducing the response combustion surface. At the same time, a safety agent is released to cover the combustion surface and reduce the combustion rate, thereby reducing the severity of the slow-burn response.

[0006] The first technical solution adopted in this invention is: a device for reducing the slow combustion response of a solid rocket motor, comprising a device body, a wireless control module, an ignition element, a propellant tank, a cryogenic ignition propellant, a safety agent, and a sealing material, wherein the device body comprises a sealed upper chamber and a lower chamber with an open bottom.

[0007] The wireless control module is located in the sealed upper chamber and is used to control the connection and disconnection of the circuit; the propellant tank is located in the lower chamber, and a low-temperature ignition propellant is fixed in the propellant tank, with an opening at the bottom; the sealing material is used to seal the opening at the bottom of the lower chamber; the ignition element is embedded in the low-temperature ignition propellant and the sealing material, and is connected to the wireless control module; the safety agent is located on the outer periphery of the propellant tank inside the lower chamber.

[0008] Preferably, the ignition element is a heating resistor.

[0009] Preferably, the medicine tank is made of metal.

[0010] Preferably, the low-temperature ignition propellant is an energetic ignition propellant with an ignition temperature range of 120℃~200℃.

[0011] Preferably, the low-temperature ignition propellant is one of the following: high-burning-rate propellant modified ammonium copper, 1-oxyphospha-4-hydroxymethyl-2,6,7-trioxabicyclo[2.2.2]octane / ammonium perchlorate agent, nitrocellulose, or nitroglycerin-based agent.

[0012] Preferably, the safety agent is a flame retardant with a melting point of less than 150°C.

[0013] Preferably, the safety agent is one of paraffin, stearic acid, or glyceryl monostearate.

[0014] Preferably, the melting point of the sealing material is in the range of 120°C to 250°C.

[0015] Preferably, the sealing material is one of tin-bismuth alloy and tin-zinc alloy.

[0016] The second technical solution adopted in this invention is: a method for reducing the slow-speed combustion response of a solid rocket motor, comprising:

[0017] The device for reducing the slow combustion response of the solid rocket motor as described in the first technical solution is placed at the head of the solid rocket motor;

[0018] When the solid propellant ammonium perchlorate-filled engine is subjected to slow-burning, if the wireless control module is functioning properly, the power is switched on via the wireless control module, the ignition element heats up and melts the sealing material to release the safety agent, and ignites the low-temperature ignition charge to ignite the solid propellant.

[0019] If the wireless control module fails to function properly, when the temperature rises to the melting point of the sealing material and the ignition temperature of the cryogenic propellant, the sealing material will automatically melt and release the safety agent, while the cryogenic propellant will ignite at high temperature and set off the solid rocket motor.

[0020] The beneficial effects of the above technical solution are as follows:

[0021] (1) The present invention provides a device for reducing the slow combustion response of a solid rocket motor. The principle is simple, the manufacturing and use are convenient, it does not affect the normal use function of the solid rocket motor, and it can significantly reduce the intensity of the slow combustion response of the solid rocket motor. That is, the device for reducing the slow combustion response of a solid rocket motor provided by the present invention can be used to reduce the intensity of the slow combustion response of the solid rocket motor, and does not change the propellant formula and performance of the solid rocket motor. It has better applicability and practicality.

[0022] (2) The present invention provides a method for reducing the slow-burn response of a solid combustion engine by placing a device for reducing the slow-burn response of a solid combustion engine at the head of the solid combustion engine. When the solid combustion engine is subjected to slow-burn heat stimulation, the solid combustion engine is ignited before the explosive charge inside it generates a large number of porous combustion surfaces, thereby significantly reducing the response combustion surface. At the same time, a safety agent is released to cover the combustion surface and reduce the combustion rate, thereby reducing the intensity of the slow-burn response. Attached Figure Description

[0023] Figure 1 The images provided in the background section of this invention show the porosity (burning surface area) of the oxidizer ammonium perchlorate in the propellant at different response temperatures.

[0024] Figure 2 A schematic diagram of a device for reducing the slow burn-out response of a solid rocket motor, provided in one embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of a slow-burn test temperature curve provided in one embodiment of the present invention;

[0026] Figure 4 This is a partial schematic diagram of the slow-burn test temperature curve provided in one embodiment of the present invention;

[0027] Among them, 1-device body; 2-wireless control module; 3-ignition element; 4-propellant tank; 5-low temperature ignition propellant; 6-safety agent; 7-sealing material. Detailed Implementation

[0028] The present invention will be further illustrated below with specific embodiments. It should be noted that those skilled in the art can make several modifications and improvements without departing from the principle of the present invention, and these should also be considered to fall within the protection scope of the present invention.

[0029] The contents not described in detail in this specification are common knowledge to those skilled in the art.

[0030] Example 1

[0031] like Figure 2 As shown, this invention discloses a device for reducing the slow combustion response of a solid rocket motor, comprising a device body 1, a wireless control module 2, an ignition element 3, a propellant tank 4, a cryogenic ignition propellant 5, a safety agent 6, and a sealing material 7. The device body 1 includes a sealed upper chamber and a lower chamber with an open bottom. The wireless control module 2 is located in the sealed upper chamber, and the propellant tank 4 is located in the lower chamber. The cryogenic ignition propellant 5 is fixed in the propellant tank 4, and the sealing material 7 is used to seal the opening at the bottom of the lower chamber. The ignition element 3 is embedded in the cryogenic ignition propellant 5 and the sealing material 7, and is connected to the wireless control module 2. The safety agent 6 is located on the outer periphery of the propellant tank 4 in the lower chamber.

[0032] Among them, the wireless control module 2 can realize the connection and disconnection of the wireless control circuit (i.e., the connection and disconnection of the power supply). When the wireless control module 2 is connected to the power supply, the ignition element 3 heats up and melts the sealing material 7 and ignites the low-temperature ignition powder 5.

[0033] The ignition element 3 is a heating resistor embedded in the low-temperature ignition propellant 5 and the sealing material 7. When energized, it generates the heat required for the ignition of the low-temperature ignition propellant 5 and melts the sealing material 7 to release the safety agent.

[0034] The flammable tank 4 is made of metal. The bottom of the flammable tank 4 has an opening for fixing the low-temperature ignition powder 5 and for ejecting the flame generated by the low-temperature ignition powder 5 through the opening at the bottom. The opening at the bottom of the flammable tank corresponds to the opening at the bottom of the lower chamber. The flame ejected from the opening of the flammable tank can be ejected from the device body 1 through the opening at the bottom of the lower chamber.

[0035] Low-temperature ignition propellant 5 is an energetic ignition propellant, including but not limited to high-burning-rate propellant modified ammonium copper (GATo), 1-oxyphospha-4-hydroxymethyl-2,6,7-trioxabicyclo[2.2.2]octane / ammonium perchlorate (PEPA / AP) propellant (PEPA / AP is a PEPA / AP paste propellant) and other propellants that can be ignited at low temperatures (such as propellants based on nitrocellulose and nitroglycerin). The ignition temperature of low-temperature ignition propellant 5 is adjustable, with an ignition temperature range of 120℃~200℃ and a usage range of 5-20g.

[0036] Safety Agent 6 is an insensitive, inert, high-boiling-point flame retardant that does not chemically react with cryogenic ignition propellants. Its melting point is adjustable, less than 150°C. Safety Agent 6 includes, but is not limited to, paraffin wax, stearic acid, and glyceryl monostearate. Its usage range is greater than 50g, and the usage can be adjusted according to the size of the engine. Safety Agent 6 prevents accidental triggering of cryogenic ignition propellants at room temperature. After melting and releasing at high temperatures, it can cover the combustion surface of the solid rocket motor, thus reducing the response combustion rate of the solid rocket motor.

[0037] The sealing material 7 is a high-temperature fusible material, including but not limited to tin-bismuth alloy, tin-zinc alloy and other metals and non-metals that meet the melting point range; its melting point is adjustable, with a melting point range of 120℃~250℃; the sealing material seals the ignition port to prevent accidental ignition (ignition of solid rocket motor) and leakage of safety agent at low temperatures.

[0038] Example 2

[0039] This invention discloses a method for reducing the slow burn-out response of a solid rocket motor, comprising:

[0040] The device for reducing the slow burn response of the solid rocket motor as described in Example 1 is placed at the head of the solid rocket motor;

[0041] When the solid propellant engine loaded with ammonium perchlorate is subjected to slow-speed combustion, if the wireless control module is functioning properly, the power is switched on via the wireless control module. The ignition element heats up and melts the sealing material, thereby releasing the safety agent and igniting the low-temperature ignition charge to ignite the solid propellant engine. This achieves the goal of igniting the solid propellant engine before the ammonium perchlorate forms a large burning surface, while simultaneously releasing the safety agent to cover the burning surface and reduce the combustion rate, thus preventing violent responses beyond combustion.

[0042] If the wireless control module fails to function properly, when the temperature rises to the melting point of the sealing material and the ignition temperature of the cryogenic propellant, the sealing material will automatically melt upon heating, releasing the safety agent. At the same time, the cryogenic propellant will ignite at high temperature and ignite the solid propellant to prevent violent reactions such as combustion.

[0043] Example 3

[0044] The slow-burn response temperature of a solid rocket motor with hydroxyl-butadiene propellant (HPP) is generally around 190℃ (heating rate 1℃ / min). To reduce its porous structure (burning surface area) at high temperatures and decrease the intensity of the response, this example sets the pre-ignition temperature of the HPP solid rocket motor to around 160℃ (the temperature can be determined based on the results of the slow-burn test of the solid rocket motor). For this purpose, 50g of paraffin flame retardant (melting point 90℃) is used as the safety agent, 5g of GATo agent (ignition temperature approximately 160℃) is used as the cryogenic ignition agent, and a tin-bismuth alloy (melting point 140℃) is used as the sealing material. After processing and integrating the device, it is placed at the Φ100mm×200mm solid rocket motor head.

[0045] like Figure 3 and Figure 4 As shown, a slow-burn test device was used to heat a solid rocket motor equipped with the low-temperature ignition device of the present invention (i.e., a device that reduces the degree of slow-burn response of the solid rocket motor) and without the low-temperature ignition device of the present invention at a heating rate of 1℃ / min. After installing the low-temperature ignition device of the present invention, the response temperature of the solid rocket motor decreased by 34℃, and the solid rocket motor responded to combustion. The solid rocket motor without the low-temperature ignition device of the present invention responded to detonation. This shows that the low-temperature ignition device of the present invention can reduce the severity of the slow-burn response of the solid rocket motor.

[0046] Example 4

[0047] The slow-burn response temperature of a certain high-energy propellant solid rocket motor is 150℃ (heating rate 3.3℃ / h). To reduce its porous structure (burning surface area) at high temperatures and decrease the intensity of the response, the pre-ignition temperature of the solid rocket motor is set to approximately 130℃ in this example. Therefore, 100g of paraffin flame retardant (melting point 70℃) is used as the safety agent, 20g of PEPA / AP agent (ignition temperature approximately 130℃) is used as the cryogenic ignition propellant, and a tin-zinc alloy (melting point 117℃~119℃) is used as the sealing material. After processing and integrating the device, it is placed at the Φ100mm×200mm solid rocket motor head.

[0048] Using a slow-burn test device, solid rocket motors equipped with and without the low-temperature ignition device of the present invention were heated at a heating rate of 3.3℃ / h. The solid rocket motor with the low-temperature ignition device of the present invention exhibited a combustion response, while the solid rocket motor without the low-temperature ignition device of the present invention exhibited a deflagration response. This indicates that the low-temperature ignition device of the present invention can reduce the severity of the slow-burn response of solid rocket motors.

[0049] The present invention has been described in detail above with reference to specific embodiments and exemplary examples. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments; the above descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and implementation methods of the present invention without departing from the spirit and scope of the present invention, and all such modifications and improvements fall within the scope of the present invention; the scope of protection of the present invention is determined by the appended claims.

Claims

1. A device for reducing the slow-burn response of a solid rocket motor, characterized in that, The device includes a device body (1), a wireless control module (2), an ignition element (3), a propellant tank (4), a low-temperature ignition propellant (5), a safety agent (6), and a sealing material (7). The device body (1) includes a sealed upper chamber and a lower chamber with an open bottom. The wireless control module (2) is located in the sealed upper chamber and is used to control the connection and disconnection of the circuit; the ignition tank (4) is located in the lower chamber, and a low-temperature ignition powder (5) is fixed in the ignition tank (4) and has an opening at the bottom; the sealing material (7) is used to seal the opening at the bottom of the lower chamber; the ignition element (3) is embedded in the low-temperature ignition powder (5) and the sealing material (7) and is connected to the wireless control module (2); the safety agent (6) is located on the outer periphery of the ignition tank (4) in the lower chamber.

2. The apparatus for reducing the slow-burn response of a solid rocket motor according to claim 1, characterized in that, The ignition element (3) is a heating resistor.

3. The apparatus for reducing the slow-burn response of a solid rocket motor according to claim 1, characterized in that, The medicine tank (4) is made of metal.

4. The apparatus for reducing the slow-burn response of a solid rocket motor according to claim 1, characterized in that, The low-temperature ignition propellant (5) is an energetic ignition propellant with an ignition temperature range of 120℃~200℃.

5. The apparatus for reducing the slow-burn response of a solid rocket motor according to claim 4, characterized in that, The low-temperature ignition propellant (5) is one of the following: high-burning-rate propellant modified ammonium copper, 1-oxyphospha-4-hydroxymethyl-2,6,7-trioxabicyclo[2.2.2]octane / ammonium perchlorate agent, nitrocellulose, or nitroglycerin-based agent.

6. The apparatus for reducing the slow burn-out response of a solid rocket motor according to claim 1, characterized in that, The safety agent (6) is a flame retardant with a melting point of less than 150°C.

7. The apparatus for reducing the slow burn-out response of a solid rocket motor according to claim 6, characterized in that, The safety agent (6) is one of paraffin, stearic acid, and glyceryl monostearate.

8. The apparatus for reducing the slow burn-out response of a solid rocket motor according to claim 1, characterized in that, The melting point of the sealing material (7) is in the range of 120℃~250℃.

9. The apparatus for reducing the slow burn-out response of a solid rocket motor according to claim 8, characterized in that, The sealing material (7) is one of tin-bismuth alloy and tin-zinc alloy.

10. A method for reducing the slow-speed burn-in response of a solid rocket motor, characterized in that, include: The device for reducing the slow burn response of a solid rocket motor as described in any one of claims 1-9 is placed at the head of the solid rocket motor. When the solid propellant ammonium perchlorate-filled engine is subjected to slow-burning, if the wireless control module is functioning properly, the power is switched on via the wireless control module, the ignition element heats up and melts the sealing material to release the safety agent, and ignites the low-temperature ignition charge to ignite the solid propellant. If the wireless control module fails to function properly, when the temperature rises to the melting point of the sealing material and the ignition temperature of the cryogenic propellant, the sealing material will automatically melt and release the safety agent, while the cryogenic propellant will ignite at high temperature and set off the solid rocket motor.

Images