Microwave plasma combustion-supporting composite solid propellant experiment system

Abstract

The invention discloses a microwave plasma combustion-supporting composite solid propellant experiment system. An air inlet and an air outlet in a main combustion chamber cavity are communicated with a first air source through an air inlet pneumatic ball valve, an air outlet pneumatic ball valve, an air inlet electromagnetic valve and an air outlet electromagnetic valve respectively; the cavity of the main combustion chamber is divided into an upper cavity and a lower cavity, the upper cavity is an ignition chamber, and two ignition electrodes are connected with a 24V direct-current power supply through wires respectively; the lower cavity is a combustion chamber; a layer of cover plate on which small holes are distributed is arranged between the upper cavity and the lower cavity to isolate the upper cavity from the lower cavity; the main combustion chamber cavity is provided with a microwave inlet connected with a microwave source; the main combustion chamber cavity can be compatible with high pressure, microwave environment and ignition, the effect of greatly improving the combustion speed of the solid propellant is achieved through energy deposition of microwave plasma, and the combustion speed of the solid propellant can be controlled in real time by controlling the microwave source in real time; compared with an existing solid propellant burning rate increasing method, the method has the incomparable advantages that the effect is remarkable, and real-time control can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of solid rocket engines, and in particular to a microwave plasma combustion-assisted composite solid propellant experimental system for solid propellants under normal pressure and high pressure. Background Art

[0002] As the main power unit of modern rocket missiles, solid rocket engines have a wide range of applications. Different from liquid rocket engines, the fuel of solid rocket engines is a solid propellant pre-loaded in the combustion chamber, so the performance of the propellant seriously affects the performance of rocket missiles. At the same time, countries around the world have developed a variety of air defense missiles to respond to missile attacks. Therefore, how to break through the interception of the increasingly improved air defense system and ensure the survival rate of missiles has also become a difficult problem in the development of rocket missiles.

[0003] Microwave plasma can inject energy into composite solid propellants, eventually forming energy deposition. Therefore, under the same other conditions, the burning rate of composite solid propellants after microwave plasma combustion can be greatly improved, so that the instantaneous pressure of the combustion chamber can also be greatly improved. If this technology is applied to the corresponding solid engine, the instantaneous thrust generated by its tail nozzle will also be greatly enhanced, so it has a very bright prospect in the penetration of missiles. However, there are very few studies on the combustion-supporting effect of microwave plasma on solid propellants in China. At present, most of the research on solid propellant combustion at home and abroad considers the technical methods of applying some physical or chemical means to achieve it. The effects of these means are usually not obvious, and the burning rate of solid propellants cannot be controlled in real time. For example, the patent application with the publication number CN111440073A discloses a method for synthesizing a burning rate regulator and its application, and a method for adjusting the burning rate of propellants using energetic materials, but there are defects that the degree of adjustment is uncontrollable and cannot be regulated in real time. Summary of the invention

[0004] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide a microwave plasma combustion-assisted composite solid propellant experimental system, in which the main combustion chamber cavity is compatible with high pressure, microwave environment and ignition, and can explore the combustion enhancement effect of microwave plasma on composite solid propellant, and fill the gap in this research direction in China.

[0005] In order to achieve the above object, the object of the present invention is achieved through the following technical solutions:

[0006] A microwave plasma combustion-assisted composite solid propellant experimental system, comprising a main combustion chamber cavity 1, an air inlet and an air outlet on the main combustion chamber cavity 1 are respectively connected to an air inlet pneumatic ball valve 9 and an air outlet pneumatic ball valve 11; the A\B ports on the air inlet pneumatic ball valve 9 and the air outlet pneumatic ball valve 11 are respectively connected to the corresponding A\B ports on the air inlet solenoid valve 10 and the air outlet solenoid valve 12;

[0007] The respective P ports on the air inlet solenoid valve 10 and the air outlet solenoid valve 12 are connected to the first air source 5-1 and the second air source 5-2 through the first pressure reducing valve 8-1 and the second pressure reducing valve 8-2 respectively;

[0008] The inlet of the air intake pneumatic ball valve 9 is connected to the third air source 5-3 through the supercharger 6 and the third pressure reducing valve 8-3 in sequence; the driving air inlet on the supercharger 6 is connected to the outlet of the air compressor 7;

[0009] The main combustion chamber cavity 1 is divided into two cavities, the upper cavity is the ignition chamber, and the two ignition electrodes are connected to the two terminals of the 24V DC power supply 2 through wires; the lower cavity is the combustion chamber; a cover plate covered with small holes is placed between the upper and lower cavities to isolate them;

[0010] The main combustion chamber cavity 1 is provided with a pressure measuring hole and connected to a pressure sensor 13, and the pressure sensor 13 is connected to a data acquisition port on a Dewesoft data acquisition instrument 14 through a data acquisition line; the signal output end on the Dewesoft data acquisition instrument 14 is connected to a computer 15;

[0011] The main combustion chamber cavity 1 is provided with a microwave inlet connected to the microwave source 3; the cooling water circulation channel on the microwave source 3 is connected to the cooling water inlet and outlet on the chiller 4 through a water pipe; and the signal input port on the microwave source 3 is connected to the computer 15.

[0012] The power of the microwave source 3 can be infinitely regulated within the range of 0-3000W.

[0013] The air outlet pneumatic ball valve 9 and the air inlet pneumatic ball valve 11 are normally closed valves.

[0014] The air outlet solenoid valve 10 and the air inlet solenoid valve 12 are two-position five-way reversing valves.

[0015] The model of the pressure sensor 13 is Da9420, the output signal is 1-5V, and the measuring range is 0-10MPa.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The method of the present invention uses microwaves to adjust the burning rate of composite solid propellants. The microwaves can be adjusted in real time through a microwave source, and the real-time microwave power and microwave action mode can be adjusted according to different needs. Therefore, it has the advantages of significant control effect and easy real-time adjustment.

[0018] 2. The present invention perfectly solves the problem of the heating wire igniting after microwave injection, thus affecting normal ignition, due to the design of separating the main combustion cavity into an ignition chamber and a combustion chamber.

[0019] 3. The present invention is designed with control valves on key gas paths. For example, a pressure reducing valve is provided at the gas source interface, and pneumatic ball valves are provided at the air inlet and the air outlet. Therefore, the on / off of each path can be controlled by a valve, which greatly increases the safety of the experiment. At the same time, when problems occur in the experiment, they can be quickly located and iterated.

[0020] In summary, the present invention achieves the effect of greatly improving the burning rate of solid propellants through the energy deposition of microwave plasma, and can control the burning rate of solid propellants in real time by real-time control of microwave sources, such as changing the power of microwaves, changing the working mode of microwaves, etc. The main combustion chamber cavity of the present invention is compatible with high pressure, microwave environment and ignition, and has proposed major innovations in both scheme and structure. Compared with the existing solid propellant burning rate improvement methods, it has incomparable advantages such as significant effect and real-time control. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a system principle diagram of the present invention. DETAILED DESCRIPTION

[0022] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0023] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0024] like Figure 1The microwave plasma combustion-assisted composite solid propellant experimental system includes a main combustion chamber cavity 1, and an air inlet and an air outlet on the main combustion chamber cavity 1 are respectively connected to an air inlet pneumatic ball valve 9 and an air outlet pneumatic ball valve 11. The air inlet pneumatic ball valve 9 and the air outlet pneumatic ball valve 11 are both normally closed valves. When the combustion chamber cavity needs to be pressurized before the experiment, the air inlet pneumatic ball valve 9 is opened, and the air outlet pneumatic ball valve 11 does not move and remains normally closed during this period; when the exhaust gas in the combustion chamber needs to be discharged after the experiment, the air outlet pneumatic ball valve 9 is opened, and the air inlet pneumatic ball valve 11 does not move and remains normally closed during this period;

[0025] The A\B ports on the air inlet pneumatic ball valve 9 and the air outlet pneumatic ball valve 11 are respectively connected to the corresponding A\B ports on the air inlet solenoid valve 10 and the air outlet solenoid valve 12. When the air inlet solenoid valve 10 and the air outlet solenoid valve 12 are powered on, the gas flows through the A port to the air inlet pneumatic ball valve 9 and the air outlet pneumatic ball valve 11 connected thereto, and pushes the internal ball valve to rotate to open the gas channel, and then flows out from the B port; when the air inlet solenoid valve 10 and the air outlet solenoid valve 12 are not powered on, the gas is blocked in front of the solenoid valve, and the ball valve inside the air inlet pneumatic ball valve 9 and the air outlet pneumatic ball valve 11 automatically resets and closes the gas channel under the action of the spring tension; the P ports on the air inlet solenoid valve 10 and the air outlet solenoid valve 12 are respectively connected to the first gas source 5-1 and the second gas source 5-2 through the first pressure reducing valve 8-1 and the second pressure reducing valve 8-2. Because the solenoid valve needs to be actuated multiple times and the gas required is only the driving gas, the pressure reducing valve 8 controls the flow of low-pressure gas to the inlet solenoid valve 10 and the outlet solenoid valve 12, which can prevent the solenoid valve from being subjected to excessive impact and extend its service life;

[0026] The inlet of the air intake pneumatic ball valve 9 is connected to the third air source 5-3 through the supercharger 6 and the third pressure reducing valve 8-3 in turn. The pressure range required in the experiment is 0-7MPa. The air source can be barely supplied when it is sufficient, but after many experiments, it is difficult to meet such high-pressure conditions. Therefore, a supercharger 6 is connected in series between the air source 5 and the air intake pneumatic ball valve 9. When the initial low-pressure air source enters from the inlet of the supercharger 6, it is compressed and pressurized by the internal pump, and then flows from the outlet to the inlet of the air intake pneumatic ball valve 9; the three pressure reducing valves are connected to the three air sources respectively; the purpose of this is mainly to reduce the gas pressure to prevent the high-pressure gas directly ejected from the air source 5 from damaging the air intake solenoid valve 10 and the air outlet solenoid valve 12, and it is also for experimental safety;

[0027] The driving air inlet on the supercharger 6 is connected to the outlet of the air compressor 7. The pump inside the supercharger 6 needs to provide a certain driving pressure, so the air compressor 7 compresses the outside air to form a driving air of 0.6MPa to drive the supercharger 6 to work;

[0028] The two ignition electrodes on the main combustion chamber cavity 1 are connected to the two terminals of the 24V DC power supply 2 through wires. One end of the two wires is connected to the two electrodes, and the other end is connected to the two terminals of the 24V DC power supply. After the power is turned on, the heating wires wound around the two electrodes inside the combustion chamber cavity will heat up quickly to ignite the propellant splines connected thereto, thereby achieving the ignition function.

[0029] The main combustion chamber cavity 1 is provided with a pressure measuring hole and connected to a pressure sensor 13. The burning of the ignited propellant spline in the combustion chamber will inevitably cause the pressure in the combustion chamber to rise. When the spline burns, the pressure in the combustion chamber will drop again. Therefore, the voltage and current output values ​​of the pressure-sensitive material of the pressure sensor 13 can reflect the pressure change inside the entire combustion chamber, and the combustion time of the propellant spline can be obtained from the time from the pressure rise point to the pressure drop point; the pressure sensor 13 is connected to the data acquisition port on the Dewesoft data acquisition instrument 14 through a data acquisition line. The Dewesoft data acquisition instrument 14 can convert the real-time voltage and current signals of the pressure sensor 13 into a visual pressure image; the signal output end on the Dewesoft data acquisition instrument 14 is connected to the computer 15.

[0030] The main combustion chamber cavity 1 is provided with a microwave inlet connected to the microwave source 3. The microwave source can generate microwaves of a specific frequency and power, and feed the microwaves into the main combustion chamber cavity 1 through a waveguide, thereby achieving the effect of microwave combustion-supporting propellant; the cooling water circulation channel on the microwave source 3 is connected to the cooling water inlet and outlet on the chiller 4 through a water pipe; the continuously working microwave source 3 generates a large amount of heat. In order to prevent the microwave source 3 from being burned, a chiller 4 is additionally provided to continuously absorb heat from the microwave source 3, thereby ensuring its normal operation; the signal input port on the microwave source 3 is connected to the computer 15.

[0031] The main combustion chamber cavity 1 is divided into two cavities, the upper cavity is an ignition chamber, which is used to ignite solid propellant; the lower cavity is a combustion chamber, which is used for burning solid propellant and feeding microwaves; a cover plate covered with small holes is placed between the two cavities to isolate them, and windows are opened on three sides of the lower cavity. The rear window is used for lighting, the front window is used for shooting, and the right window matches the size of the microwave source 3 outlet and is used as the microwave entrance.

[0032] The power of the microwave source 3 can be infinitely regulated within the range of 0-3000W; in addition, it can be regulated to realize two working modes: continuous triggering and pulse triggering.

[0033] The air outlet pneumatic ball valve 9 and the air inlet pneumatic ball valve 11 are normally closed valves.

[0034] The air outlet solenoid valve 10 and the air inlet solenoid valve 12 are two-position five-way reversing valves.

[0035] The pressure sensor 13 is of model Da9420, with an output signal of 1-5V and a measuring range of 0-10Mpa.

[0036] The working principle of the present invention is:

[0037] (1) Preliminary loading of propellant: Open the upper end cover of the main combustion chamber cavity 1, pass the heating wire through the propellant and wrap it around the two ignition electrodes, use a special polytetrafluoroethylene clamping block to clamp the bottom of the propellant on the suspended polytetrafluoroethylene clamping plate and fix it, then cover the upper end cover, and finally tighten it with screws to ensure the sealing of the combustion chamber.

[0038] (2) Inject gas to simulate high-pressure environment: Connect the air intake solenoid valve 10 to a 24V DC power supply. After power is turned on, the low-pressure gas reduced by the first pressure reducing valve 8-1 pushes the ball valve in the air intake pneumatic ball valve 9 to rotate, so that the air intake channel is opened, and the air outlet pneumatic ball valve 11 is kept closed during this period. Then, let the air compressor 7 work first to provide low-pressure driving gas for the supercharger 6, and then set the outlet pressure of the supercharger (that is, the pressure in the combustion chamber), wait for the supercharger to continue working so that the entire combustion chamber is filled with high-pressure gas, and finally disconnect the power supply of the air intake solenoid valve 10, the ball valve in the air intake pneumatic ball valve 9 is reset, and the air intake channel is closed.

[0039] (3) Feeding into the microwave environment: first turn on the chiller 4 to keep it working, then turn on the microwave source 3, adjust the three pins on the microwave source to adjust the reflected power of the microwave so that it does not exceed 50% and is as low as possible, wait for the microwave source to work stably, and finally successfully feed the microwave into the main combustion chamber cavity 1.

[0040] (4) Ignition: Under high-voltage, microwave conditions, the propellant needs to be ignited and burned. One end of the two wires is connected to the electrode on the upper end cover of the combustion chamber, and the other end is connected to a 24V DC power supply. After the power is turned on, the heating wire inside the combustion chamber heats up and ignites the propellant spline. At the same time, the pressure measurement curve on the Devesoft is observed, and it is found that the pressure inside the combustion chamber begins to rise.

[0041] (5) Exhaust: Observe the pressure measurement curve. When the pressure curve stops rising and tends to be stable, it indicates that the propellant spline combustion is over. At this time, connect the outlet solenoid valve 12 to the 24V DC power supply. After power is turned on, the low-pressure gas reduced by the second pressure reducing valve 8-2 pushes the ball valve in the outlet pneumatic ball valve 11 to rotate, so that the outlet channel is opened. During this period, the inlet pneumatic ball valve 9 is kept closed. After the combustion exhaust gas in the combustion chamber is exhausted, one experimental cycle is completed.

[0042] The present invention designs a microwave plasma composite solid propellant combustion-supporting experimental system by itself, and feeds microwaves into the combustion cavity to achieve microwave combustion enhancement of composite solid propellants. Compared with the traditional method of influencing the burning rate of propellants through various physical and chemical means, microwave combustion-supporting can turn on microwaves at any time to achieve real-time burning rate regulation, and at the same time, infinite burning rate regulation can be achieved by adjusting the microwave power, which provides a more effective means for propellant combustion enhancement and can provide a new strategy for missile penetration.

[0043] The embodiments described above are only preferred specific implementations of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A microwave plasma combustion-assisted composite solid propellant experimental system, comprising a main combustion chamber cavity (1), characterized in that: The air inlet and the air outlet on the main combustion chamber cavity (1) are respectively connected to the air inlet pneumatic ball valve (9) and the air outlet pneumatic ball valve (11); the A\B ports on the air inlet pneumatic ball valve (9) and the air outlet pneumatic ball valve (11) are respectively connected to the corresponding A\B ports on the air inlet solenoid valve (10) and the air outlet solenoid valve (12); The respective P ports on the air inlet solenoid valve (10) and the air outlet solenoid valve (12) are connected to the first air source (5-1) and the second air source (5-2) through the first pressure reducing valve (8-1) and the second pressure reducing valve (8-2); The inlet of the air intake pneumatic ball valve (9) is connected to the third air source (5-3) through the supercharger (6) and the third pressure reducing valve (8-3) in sequence; the driving air inlet on the supercharger (6) is connected to the outlet of the air compressor (7); The main combustion chamber cavity (1) is divided into two cavities, the upper cavity being an ignition chamber, and the two ignition electrodes are respectively connected to the two terminals of a 24V DC power supply (2) through wires; the lower cavity is a combustion chamber; A cover plate covered with small holes is placed between the upper and lower cavities to isolate them; The main combustion chamber cavity (1) is provided with a pressure measuring hole and is connected to a pressure sensor (13); the pressure sensor (13) is connected to a data acquisition port on a Dewesoft data acquisition instrument (14) via a data acquisition line; the signal output end on the Dewesoft data acquisition instrument (14) is connected to a computer (15); The main combustion chamber cavity (1) is provided with a microwave inlet connected to the microwave source (3); a cooling water circulation channel on the microwave source (3) is connected to a cooling water inlet and outlet on a chiller (4) via a water pipe; and a signal input port on the microwave source (3) is connected to a computer (15).

2. A microwave plasma combustion-assisted composite solid propellant experimental system according to claim 1, characterized in that: The power of the microwave source (3) can be infinitely regulated within the range of 0-3000W.

3. The microwave plasma combustion-assisted composite solid propellant experimental system according to claim 1, characterized in that: The air outlet pneumatic ball valve (9) and the air inlet pneumatic ball valve (11) are normally closed valves.

4. The microwave plasma combustion-assisted composite solid propellant experimental system according to claim 1, characterized in that: The air outlet solenoid valve (10) and the air inlet solenoid valve (12) are two-position five-way reversing valves.

5. The microwave plasma combustion-assisted composite solid propellant experimental system according to claim 1, characterized in that: The model of the pressure sensor (13) is Da9420, the output signal is 1-5V, and the measurement range is 0-10MPa.

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