A method for preventing backflow impact in high-altitude simulation tests of solid rocket motors

Abstract

This invention discloses a method for preventing backflow impact in high-altitude simulation tests of solid rocket motors. A bidirectional sealing gate valve is installed between the diffuser and the ejector pipe. At the start of the test, after the ejector system is activated, the gate valve opens, the engine ignites, maintaining a low pressure of 1 kPa within the test chamber and allowing exhaust gases to escape, forming a stable flow field. The gate valve closes at the end of ignition, and nitrogen is injected into the test chamber in stages to restore atmospheric pressure, preventing sudden pressure changes that could damage the engine structure. This invention, through the bidirectional sealing gate valve structure and the nitrogen staged replenishment system, utilizes the sealing and isolation characteristics of the gate valve to solve the backflow impact problem in high-altitude simulation tests of solid rocket motors, maintaining a constant low-pressure environment in the test chamber, completely eliminating exhaust gas backflow, protecting the structural integrity of the engine after the test, and improving the test success rate.

Description

Technical Field

[0001] This invention belongs to the field of aerospace engine testing technology, specifically relating to a method for preventing backflow impact during high-altitude simulation testing of solid rocket motors. Background Technology

[0002] Active ejection high-altitude simulation test is used to evaluate the structure and performance of an engine in a vacuum environment. Its core is to use high-speed gas from the gas generator group to carry out the air and engine gas in the test chamber, maintain the low-pressure environment of the test chamber, and simulate high-altitude working conditions.

[0003] Existing technical problem: In high-altitude simulation tests of solid rocket motors, after engine ignition, the combustor stops working. During the shutdown process of the ejector system, the test chamber cannot maintain a high-altitude low-pressure environment. Atmospheric pressure outside the ejector pipe flows back into the test chamber, causing a reverse impact on the engine, resulting in engine structural damage and affecting the analysis of the product structure after the test.

[0004] Therefore, there is a need to develop a low-cost, high-reliability method that simultaneously maintains a low-pressure seal and blocks backflow at the end of engine ignition. Summary of the Invention

[0005] To address the aforementioned issues, this invention discloses a method for preventing backflow impact during high-altitude simulation testing of solid rocket motors. By improving the ejector system shutdown process and pressure control mechanism, the backflow path is simultaneously blocked after engine ignition, maintaining a low-pressure seal in the test chamber and safely restoring the normal pressure environment.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A method for preventing backflow impact in high-altitude simulation tests of solid rocket motors involves installing a bidirectional sealing gate valve between the diffuser and the ejector pipe. This valve remains open during engine ignition and closes at the end of ignition. After closing, nitrogen is injected into the test chamber in stages to restore atmospheric pressure. The staged process is as follows:

[0008] Phase 1: Increase the pressure to 30% of atmospheric pressure at a rate of 2 kPa / s;

[0009] Second stage: pressurize to atmospheric pressure at a rate of 1 kPa / s.

[0010] A backflow protection system for high-altitude simulation testing of a solid rocket motor includes a test chamber, diffuser, ejector pipe, annular burner, a two-way sealed gate valve structure, and a nitrogen staged replenishment system.

[0011] The test chamber is equipped with an engine.

[0012] The diffuser is located at the engine nozzle exit.

[0013] The bidirectional sealing gate valve structure is disposed between the diffuser and the extended ejector pipe;

[0014] The annular igniter is located on the outside of the injector pipe;

[0015] The nitrogen staged pressurization system is connected to the test chamber.

[0016] Furthermore, the bidirectional sealing gate valve structure includes a valve body, a valve plate, a water-cooling duct, and a drive mechanism.

[0017] The valve body is made of high-temperature alloy casting, and the internal flow channels are coated with a silicon carbide ceramic layer.

[0018] The valve plate has a built-in spiral water-cooling conduit.

[0019] The drive mechanism includes a motor and a sliding rod, and the motor is connected to the valve plate through the sliding rod.

[0020] The motor is connected to a remote control box.

[0021] Furthermore, a limit switch is provided at the rear end of the sliding rod, and the limit switch is connected to the remote control box.

[0022] Furthermore, the nitrogen staged pressurization system connects high-pressure nitrogen to the test chamber via a pneumatic valve controlled by a solenoid valve.

[0023] Furthermore, the remote control box integrates a PLC controller for time-sequential control of automatically triggered valve switching commands, eliminating the risks and dangers of manual operation delays.

[0024] The beneficial effects of this invention are as follows:

[0025] This invention has a reasonable structure and ingenious design. By closing the gate valve after engine ignition, the low-pressure environment of the test chamber is maintained, completely eliminating the problem of gas backflow, protecting the structural integrity of the engine after the test, and improving the success rate of the test. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the backflow impact method in the high-altitude simulation test of a solid rocket motor in this invention;

[0027] Figure 2 This is a schematic diagram of the gate valve structure in this invention.

[0028] List of identifiers in attached diagrams:

[0029] 1. Test chamber, 2. Engine, 3. Diffuser, 4. Gate valve, 5. Ejector pipe, 6. Nitrogen replenishment device, 7. Annular gas generator, 8. Valve body, 9. Water cooling pipe, 10. Valve plate, 11. Sliding connecting rod, 12. Internal flow channel, 13. Limit switch, 14. Remote control box. Detailed Implementation

[0030] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0031] As shown in the figure, the solid rocket motor high-altitude simulation test backflow prevention system of the present invention includes a test chamber, a diffuser, an ejector pipe, an annular burner, a two-way sealed gate valve structure, and a nitrogen staged replenishment system.

[0032] The test chamber is equipped with an engine.

[0033] The diffuser is located at the engine nozzle outlet for the exhaust gas flow from engine nozzle 2.

[0034] The bidirectional sealing gate valve structure is disposed between the diffuser and the extended ejector pipe;

[0035] The annular igniter is located outside the ejector pipe. It ignites high-pressure alcohol and oxygen to form a high-speed airflow, which is used to draw in engine combustion gases and air from the test chamber to create and maintain a low-pressure environment and smoothly discharge the combustion gases.

[0036] The nitrogen staged pressurization system is connected to the test chamber. After the ejector system is shut down, nitrogen is injected into the test chamber 1 to restore normal pressure in stages.

[0037] The bidirectional sealing gate valve structure includes a valve body, a valve plate, a water-cooling duct, and a drive mechanism.

[0038] The valve body 8 is made of high-temperature alloy casting, and the internal flow channels are coated with a silicon carbide ceramic layer.

[0039] The valve plate 10 has a built-in spiral water-cooled conduit 9. The cooling water inlet pressure of the water-cooled conduit 9 is 0.8-1.5MPa, and the flow velocity is ≥2m / s.

[0040] The drive mechanism includes a motor and a sliding rod 11. The motor is connected to the valve plate 10 through the sliding rod 11 and is used to adjust the position of the gate valve. A sensing limit switch 13 is set at the rear end of the sliding rod 11 to detect the opening and closing position of the valve plate 10 in real time and feed it back to the remote control box 14. The sensing limit switch 13 adopts a magnetic induction sensor with an accuracy error ≤0.1mm.

[0041] Its backflow impact prevention method is controlled by the coordinated operation of the two-way sealing gate valve 4 structure and the nitrogen staged replenishment system 6:

[0042] Ignition phase: Engine 2 is running, the gate valve 4 remains open, the ejector system maintains the chamber pressure of the test chamber at 1 kPa; the water cooling system continues to operate, and the valve plate temperature is stable below 200°C.

[0043] Engine shutdown and valve closure phase: When the engine ignition ends, the PLC controller in the remote control box sends a command to close the gate valve at that moment; the sliding rod 11 drives the valve plate 10 to close, and the inductive limit switch 13 provides feedback confirmation signal that the valve is closed.

[0044] Nitrogen recovery phase: After the ejector system is shut down, the nitrogen pressurization system 6 injects nitrogen according to a preset program, which is divided into two phases:

[0045] Phase 1: Increase the pressure to 30% of atmospheric pressure at a rate of 2 kPa / s;

[0046] Second stage: pressurize to atmospheric pressure at a rate of 1 kPa / s.

[0047] It should be noted that the above content merely illustrates the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. For those skilled in the art, various improvements and modifications can be made without departing from the principle of the present invention, and all such improvements and modifications fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preventing backflow impact in a solid motor high altitude simulation test, characterized in that: A two-way sealing gate valve structure (4) is set between the diffuser (3) and the ejector pipe (5). It is kept open during the ignition of the engine (2) and closed when the ignition ends. After closing, nitrogen is injected into the test chamber in stages to restore the normal pressure. The staged nitrogen injection process is as follows: Phase 1: Increase the pressure to 30% of atmospheric pressure at a rate of 2 kPa / s; Second stage: pressurize to atmospheric pressure at a rate of 1 kPa / s.

2. A solid rocket motor high-altitude simulation test backflow impact prevention system for implementing the backflow impact prevention method as described in claim 1, characterized in that: Its system includes a test chamber (1), a diffuser (3), an ejector pipe (5), an annular igniter (7), a two-way sealed gate valve structure (4), and a nitrogen staged replenishment system (6). The test chamber (1) is equipped with an engine (2). The diffuser (3) is located at the nozzle outlet of the engine (2). The bidirectional sealing gate valve structure (4) is located between the diffuser 3 and the extended ejector pipe (5); The annular igniter (7) is located outside the ejector pipe (5); The nitrogen staged replenishment system (6) is connected to the test chamber (1).

3. The anti-backflow impact system for high-altitude simulation testing of solid rocket motors according to claim 2, characterized in that: The bidirectional sealing gate valve structure (4) includes a valve body (8), a valve plate (10), a water-cooling duct (9), and a drive mechanism. The valve body (8) is made of high-temperature alloy casting, and the internal flow channel is coated with a silicon carbide ceramic layer. The valve plate (10) has a built-in spiral water-cooling conduit (9). The drive mechanism includes a motor and a sliding rod (11), and the motor is connected to the valve plate (10) through the sliding rod (11). The motor is connected to the remote control box (14).

4. The anti-backflow impact system for high-altitude simulation testing of solid rocket motors according to claim 3, characterized in that: A sensing limit switch (13) is provided at the rear end of the sliding rod (11), and the sensing limit switch (13) is connected to the remote control box (14).

5. The anti-backflow impact system for high-altitude simulation testing of solid rocket motors according to claim 2, characterized in that: The nitrogen staged replenishment system (6) connects high-pressure nitrogen to the test chamber (1) via a pneumatic valve controlled by a solenoid valve.

6. The anti-backflow impact system for high-altitude simulation testing of solid rocket motors according to claim 3 or 4, characterized in that: The remote control box (14) integrates a PLC controller.

7. The anti-backflow impact system for high-altitude simulation testing of solid rocket motors according to claim 3, characterized in that: The cooling water inlet pressure of the water-cooled conduit (9) is 0.8-1.5MPa, the flow rate is ≥2m / s, and the working temperature of the valve plate (10) surface is ≤200℃.

8. The anti-backflow impact system for high-altitude simulation testing of solid rocket motors according to claim 4, characterized in that: The inductive limit switch (13) uses a magnetic induction sensor with an accuracy error of ≤0.1mm. It sends the gate valve position signal to the remote control box (14) in real time according to the characteristic position.

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