A flip test system for liquid cryogenic propellants and method of use

Abstract

The embodiment of the present application relates to the technical field of rocket recovery, in particular to a kind of liquid cryogenic propellant's turnover test system and application method.The system includes: storage tank, with the engine of gas propelling device is communicated, for storing the cryogenic propellant required by engine propulsion;Refrigeration assembly, in communication with the storage tank, for cooling treatment to the cryogenic propellant stored in the storage tank;Accumulator, at the position where the storage tank is communicated with the engine, for storing part of the cryogenic propellant stored in the storage tank in the accumulator;Turnover assembly, electrically connected with the storage tank, for turning over the storage tank, so that the cryogenic propellant stored in the accumulator flows back to the storage tank;A plurality of pressure sensors are distributed at different height positions on the inner wall of the storage tank, for measuring the pressure of the cryogenic propellant at the bottom of the storage tank before and after turning over.The technical scheme of the present application can measure the volume of the cryogenic propellant stored in the accumulator by turning over the storage tank, and then analyze the flow accumulation capacity of the accumulator.

Description

Technical Field

[0001] This invention relates to the field of rocket recovery technology, and in particular to a flipping test system and application method for liquid cryogenic propellants. Background Technology

[0002] Rocket recovery and reuse is a key development direction in aerospace engineering. Specifically, after a rocket completes its mission of launching a satellite into orbit, a series of technical means are used to safely return it to Earth for reuse. Because the weightless environment during rocket recovery can cause instability in the liquid state within the cryogenic propellant tanks, leading to gas-liquid mixing and affecting the rocket engine's startup. To ensure normal engine startup during rocket recovery, a portion of the cryogenic propellant stored in the tanks is typically stored in an accumulator. Therefore, evaluating the accumulator's storage capacity is a pressing technical problem that needs to be solved. Summary of the Invention

[0003] This invention provides a flipping test system and application method for liquid cryogenic propellants, which can measure the volume of cryogenic propellant stored in the accumulator by flipping the storage tank, and then analyze the accumulator's storage capacity.

[0004] In a first aspect, the present invention provides a flipping test system for liquid cryogenic propellants, comprising:

[0005] The storage tank, connected to the engine of the gas-powered propulsion system, is used to store the cryogenic propellant required for engine propulsion.

[0006] A refrigeration component, connected to the storage tank, is used to cool the cryogenic propellant stored in the storage tank using a refrigerant.

[0007] An accumulator, disposed inside the storage tank and located at the position where the storage tank communicates with the engine, is used to store a portion of the cryogenic propellant stored in the storage tank within the accumulator;

[0008] A flipping assembly, electrically connected to the storage tank, is used to flip the storage tank so that the cryogenic propellant stored in the accumulator flows back into the storage tank;

[0009] Multiple pressure sensors are distributed at different heights on the inner wall of the tank to measure the pressure of the cryogenic propellant at the bottom of the tank before and after the tank is overturned.

[0010] In a second aspect, the present invention provides an application method for a liquid cryogenic propellant overturning test system, applied to the system described in the first aspect, comprising:

[0011] The storage tank stores the cryogenic propellant required for engine propulsion.

[0012] The refrigeration component uses a refrigerant to cool the cryogenic propellant stored in the tank, so that the volume ratio of liquid cryogenic propellant to gaseous cryogenic propellant stored in the tank reaches a preset threshold.

[0013] The accumulator stores a portion of the cryogenic propellant stored in the tank within the accumulator, and when the cryogenic propellant in the tank separates from the engine, the internally stored cryogenic propellant is supplied to the engine.

[0014] The first pressure value of the cryogenic propellant at the bottom of the tank is measured by a pressure sensor located at the bottom of the tank.

[0015] The tank is flipped by the flipping assembly, allowing the cryogenic propellant stored in the accumulator to flow back into the tank;

[0016] The second pressure value of the cryogenic propellant at the bottom of the tank is measured by a pressure sensor located at the bottom of the tank after it has been overturned.

[0017] The performance of the storage tank is tested based on the first pressure value and the second pressure value.

[0018] This invention provides a system and method for testing the flipping of liquid cryogenic propellants. The system adjusts the cooling level of the cryogenic propellant within the storage tank using refrigeration components, thereby controlling the gas-liquid ratio and simulating different operating conditions during rocket recovery. The volume of cryogenic propellant stored in the accumulator is measured by flipping the tank, and the liquid volume is calculated using pressure sensors. This allows for analysis of the accumulator's storage capacity under different operating conditions, yielding accurate storage capacity test results. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a structural block diagram of a liquid cryogenic propellant flipping test system provided in an embodiment of the present invention.

[0021] Figure label:

[0022] 1-Compressor;

[0023] 2-Cooler;

[0024] 3-Regenerator;

[0025] 4-Turbine expander;

[0026] 5-Cold screen;

[0027] 6- Flip component;

[0028] 7-Storage tank;

[0029] 8-Accumulator;

[0030] 9-Injection tube;

[0031] 10 - First solenoid valve;

[0032] 11-Drain pipe;

[0033] 12-Second solenoid valve;

[0034] 13-Pressure sensor. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0036] Please refer to Figure 1 This invention provides a system for testing the overturning of liquid cryogenic propellants, comprising:

[0037] Storage tank 7 is connected to the engine of the gas propulsion system and is used to store cryogenic propellant required for engine propulsion.

[0038] A refrigeration unit, connected to the storage tank 7, is used to cool the cryogenic propellant stored in the storage tank 7 using a refrigerant.

[0039] Accumulator 8 is installed inside tank 7 and located at the position where tank 7 is connected to engine, and is used to store part of the cryogenic propellant stored in tank 7 in accumulator 8;

[0040] The flipping component 6 is electrically connected to the storage tank 7 and is used to flip the storage tank 7 so that the cryogenic propellant stored in the accumulator 8 flows back into the storage tank 7;

[0041] Multiple pressure sensors 13 are distributed at different heights on the inner wall of the tank 7 to measure the pressure of the cryogenic propellant at the bottom of the tank 7 before and after the tank is overturned.

[0042] This invention provides a flip-up cryogenic propellant testing platform, comprising: a storage tank 7, a refrigeration assembly, an accumulator 8, a flipping assembly 6, and multiple pressure sensors 13. The storage tank 7 stores cryogenic propellant, preferably methane. The refrigeration assembly cools the cryogenic propellant in the storage tank 7, and can adjust the ratio of gaseous to liquid cryogenic propellant in the tank 7 by regulating the refrigeration capacity to simulate various operating conditions during the recovery process of a gas-propelled vehicle. The accumulator 8 temporarily stores a portion of the cryogenic propellant in the storage tank 7. The accumulator 8 is a device located at the point where the storage tank 7 connects to the engine, capable of temporarily storing a portion of the cryogenic propellant. During the recovery process of a gas-propelled vehicle (e.g., a rocket), if the cryogenic propellant in the storage tank 7 separates from the engine inlet, resulting in a failure to provide cryogenic propellant to the engine, the temporarily stored cryogenic propellant is supplied to the engine. The flipping assembly 6 (preferably a motor) flips the storage tank 7, allowing the cryogenic propellant in the accumulator 8 to flow back into the storage tank 7. Multiple pressure sensors 13 are distributed at different heights on the inner wall of the storage tank 7. Before and after the tank 7 is overturned, the pressure values ​​are collected by the pressure sensor 13 located at the bottom of the tank 7. The volume of cryogenic propellant in the tank 7 before and after the overturn is calculated using the pressure value, the density of the cryogenic propellant, and the dimensions of the tank 7. It can be understood that the difference in volume of cryogenic propellant in the tank 7 before and after the overturn is the volume of cryogenic propellant temporarily stored in the accumulator 8. This value reflects the storage capacity of the accumulator 8, i.e., the performance of the accumulator 8.

[0043] The specific experimental procedure is as follows: The accumulator 8 to be tested is installed at the bottom of the storage tank 7. After injecting a preset volume of cryogenic propellant into the storage tank 7, the parameters of each instrument are adjusted. After the instrument parameters reach the preset threshold and operate normally, the refrigeration component is activated to supply cold energy to the cryogenic propellant in the storage tank 7, so that the cryogenic propellant in the storage tank 7 reaches the preset gas-liquid ratio. At this time, the pressure value caused by the cryogenic propellant liquid surface at the bottom of the storage tank 7 is measured by the sensor at the bottom of the storage tank 7 among multiple pressure sensors 13. Based on this pressure value, the liquid level height of the cryogenic propellant in the storage tank 7 is calculated, and then the volume of the cryogenic propellant in the storage tank 7 is calculated. At this time, a portion of the cryogenic propellant is stored in the accumulator 8, which is in an accumulator state. This state is maintained for 3-4 minutes, and the flipping component 6 is run to flip the storage tank 7, so that the cryogenic propellant in the accumulator 8 flows back into the storage tank 7. Then, the pressure sensor 13 located at the bottom of the storage tank 7 at this time completes the steps of measuring the pressure value, calculating the liquid level height, and calculating the volume of the cryogenic propellant in the storage tank 7. The difference between the cryogenic propellant volume before and after the flip is the volume of liquid stored in accumulator 8. Record the liquid volume in accumulator 8 obtained during this experiment. Based on the operating parameters required for the next test experiment, adjust the volume of cryogenic propellant in tank 7 (injecting or removing some cryogenic propellant), and adjust the power of the cooling components to the cooling capacity required for the new operating conditions. This allows the cryogenic propellant in tank 7 to reach a new gas-liquid ratio and liquid level. Repeat the above experimental steps, recording the measured liquid volume in accumulator 8, until all operating condition measurements are completed.

[0044] In one embodiment of the present invention, the storage tank 7 has a spherical structure.

[0045] In this embodiment, the storage tank 7 is designed as a spherical structure. This ensures that during the flipping process, regardless of the angle to which it is flipped, the relationship between the cryogenic propellant level at the bottom of the storage tank 7 and the liquid volume remains consistent. That is, the liquid volume can be calculated based on the liquid level and the radius of the spherical structure. It is understood that the conversion relationship between pressure and liquid level is established using the formula... P=ρgh get, P The pressure value collected by pressure sensor 13. ρ The density of the cryogenic propellant inside storage tank 7. h This refers to the liquid level height. g Gravitational acceleration.

[0046] In one embodiment of the present invention, the cooling component includes: a cooling screen 5 and a circulating cooling unit;

[0047] The circulating refrigeration unit is connected to the cold screen 5 and is used to cool the refrigerant and deliver the cooled refrigerant to the cold screen 5.

[0048] The cold shield 5 is installed outside the storage tank 7 and is used to cool the cryogenic propellant in the storage tank 7 with the refrigerant delivered by the circulating refrigeration unit, and to return the refrigerant after cooling the cryogenic propellant to the circulating refrigeration unit.

[0049] In this embodiment, the circulating refrigeration unit is a reverse Brayton cycle refrigeration unit, which can deliver cooling energy to the cryogenic propellant in the storage tank 7 according to the parameters required by the experiment, so as to achieve a given gas-liquid ratio in the cryogenic propellant in the storage tank 7. The refrigerant flows into the cold shield 5, and heat exchange occurs between the cold shield 5 and the cryogenic propellant in the storage tank 7, thereby cooling the cryogenic propellant in the storage tank 7.

[0050] In one embodiment of the present invention, the cold screen 5 is a coil structure.

[0051] In this embodiment, the cold shield 5 is a coil structure that wraps around the outside of the storage tank 7 and does not affect the rotation of the storage tank 7.

[0052] In one embodiment of the present invention, the cyclic refrigeration unit includes: a compressor 1, a cooler 2, a regenerator 3, and a turbine expander 4;

[0053] The outlet of compressor 1 is connected to the cold end inlet of cooler 2, which is used to compress the refrigerant flowing into compressor 1 and deliver the compressed refrigerant to cooler 2.

[0054] The cold end outlet of the cooler 2 is connected to the cold end inlet of the regenerator 3, which is used to cool down the refrigerant flowing out of the compressor 1 and then transport the cooled refrigerant to the regenerator 3.

[0055] The cold end outlet of the regenerator 3 is connected to the inlet of the turbine expander 4, and the hot end inlet is connected to the outlet of the cold screen 5. It is used to cool the refrigerant flowing out of the cooler 2 with the refrigerant flowing out of the cold screen 5, and then return the refrigerant from the cold screen 5 to the hot end inlet of the cooler 2. The refrigerant from the cold end outlet of the cooler 2 is transported to the inlet of the turbine expander 4. The refrigerant flowing into the hot end inlet of the cooler 2 flows out through the hot end outlet of the cooler 2 and flows into the inlet of the compressor 1.

[0056] The outlet of the turbo expander 4 is connected to the inlet of the cold screen 5, which is used to expand and cool the refrigerant flowing out of the regenerator 3, and then transport the expanded and cooled refrigerant to the cold screen 5.

[0057] In this embodiment, compressor 1, cooler 2, regenerator 3, turbine expander 4, and cold shield 5 constitute a reverse Brayton cycle refrigeration unit. Compressor 1 adiabatically compresses and increases the temperature and pressure of the circulating refrigerant (preferably nitrogen), then cools it in cooler 2, reheats it in regenerator 3, expands and cools it in turbine expander 4 to reach the target temperature, and then enters cold shield 5 to exchange heat with the cryogenic propellant alkyl in storage tank 7. By controlling the power of compressor 1, the refrigeration capacity of the cycle is controlled, and the gas-liquid ratio is dynamically adjusted.

[0058] In one embodiment of the present invention, it further includes:

[0059] Injection pipe 9 is connected to storage tank 7 and is used to deliver cryogenic propellant into storage tank 7;

[0060] The drain pipe 11 is connected to the storage tank 7 and is used to drain the cryogenic propellant in the storage tank 7.

[0061] In this embodiment, the injection pipe 9 and the drain pipe 11 are connected to the storage tank 7 via flexible hoses, without affecting the tilting of the storage tank 7. During the experiment, after the accumulator 8 is installed inside the storage tank 7, liquid cryogenic propellant can be injected into the storage tank 7 through the injection pipe 9. After the cryogenic propellant reaches the designated height in the storage tank 7, subsequent experimental steps are performed. After the experiment, according to another operating condition required by the experiment, a portion of the working fluid is discharged through the drain pipe 11, and the reverse Brayton cycle system is adjusted to the cooling capacity required for the new operating condition.

[0062] In one embodiment of the present invention, it further includes:

[0063] The first solenoid valve 10 is installed on the injection pipe 9 and is used to adjust the flow rate of cryogenic propellant delivered by the injection pipe 9.

[0064] The second solenoid valve 12 is installed on the drain pipe 11 and is used to adjust the flow rate of cryogenic propellant discharged from the drain pipe 11.

[0065] In this embodiment, the injection pipe 9 is controlled by the first solenoid valve 10, and the drainage pipe 11 is controlled by the second solenoid valve 12. The first solenoid valve 10 and the second solenoid valve 12 are normally open when de-energized to prevent pressure buildup and explosion in case of accidents.

[0066] Furthermore, the application method of the liquid cryogenic propellant overturning test system of the present invention is applied to a liquid cryogenic propellant overturning test system, comprising:

[0067] The cryogenic propellant required for engine propulsion is stored in storage tanks;

[0068] The cryogenic propellant stored in the tank is cooled by a refrigerant using a refrigeration component, so that the volume ratio of liquid cryogenic propellant to gaseous cryogenic propellant stored in the tank reaches a preset threshold.

[0069] A portion of the cryogenic propellant stored in the tank is stored in the accumulator, and when the cryogenic propellant in the tank is separated from the engine, the internally stored cryogenic propellant is delivered to the engine.

[0070] The first pressure value of the cryogenic propellant at the bottom of the tank is measured by a pressure sensor located at the bottom of the tank.

[0071] The storage tank is flipped by the flipping component, allowing the cryogenic propellant stored in the accumulator to flow back into the storage tank;

[0072] The second pressure value of the cryogenic propellant at the bottom of the tank was measured by a pressure sensor located at the bottom of the overturned tank.

[0073] The performance of the storage tank was tested based on the first and second pressure values.

[0074] In one embodiment of the present invention, testing the performance of the storage tank based on a first pressure value and a second pressure value includes:

[0075] Based on the first pressure value, the density and pressure formula of the cryogenic propellant, the first storage volume of the cryogenic propellant in the tank before overturning is obtained;

[0076] Based on the second pressure value, the density and pressure formula of the cryogenic propellant, the second storage volume of the cryogenic propellant in the tank after the overturning is obtained;

[0077] Based on the first and second storage volumes, the third storage volume when the accumulator stores cryogenic propellant is obtained.

[0078] In one embodiment of the present invention, the system further includes: an injection pipe and a drain pipe, the injection pipe and the drain pipe being respectively connected to a storage tank;

[0079] Cryogenic propellant is delivered into the storage tank via an injection pipe;

[0080] The cryogenic propellant in the storage tank is discharged through the drain pipe.

[0081] It is understood that the method embodiments and apparatus embodiments provided by the present invention are based on the same inventive concept and have the same beneficial effects. The beneficial effects of the method embodiments will not be elaborated here.

[0082] In summary, the liquid cryogenic propellant overturning test system and application method provided by the embodiments of the present invention have the following technical effects:

[0083] By adjusting the cooling level of the cryogenic propellant within the storage tank using refrigeration components, the gas-liquid ratio of the cryogenic propellant can be controlled, simulating different operating conditions during rocket recovery. Furthermore, the volume of cryogenic propellant stored in the accumulator is measured by flipping the tank, and the liquid volume is calculated using pressure sensors. This allows for analysis of the accumulator's storage capacity under different operating conditions, yielding accurate storage capacity test results and filling a gap in the field of cryogenic propellant flipping testing.

[0084] It should be noted that, in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0085] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A system for testing the overturning of liquid cryogenic propellants, characterized in that, include: The storage tank, connected to the engine of the gas-powered propulsion system, is used to store the cryogenic propellant required for engine propulsion. A refrigeration component, connected to the storage tank, is used to cool the cryogenic propellant stored in the storage tank using a refrigerant. An accumulator, disposed inside the storage tank and located at the position where the storage tank communicates with the engine, is used to store a portion of the cryogenic propellant stored in the storage tank within the accumulator; A flipping assembly, electrically connected to the storage tank, is used to flip the storage tank so that the cryogenic propellant stored in the accumulator flows back into the storage tank; Multiple pressure sensors are distributed at different heights on the inner wall of the tank to measure the pressure of the cryogenic propellant at the bottom of the tank before and after the tank is overturned.

2. The system according to claim 1, characterized in that, The storage tank has a spherical structure.

3. The system according to claim 1, characterized in that, The refrigeration components include: a cold shield and a circulating refrigeration unit; The circulating refrigeration unit is connected to the cold screen and is used to cool the refrigerant and deliver the cooled refrigerant to the cold screen. The cold shield is located outside the storage tank and is used to cool the cryogenic propellant in the storage tank with the refrigerant supplied by the circulating refrigeration unit, and to return the cooled refrigerant to the circulating refrigeration unit.

4. The system according to claim 3, characterized in that, The cold shield has a coil structure.

5. The system according to claim 3, characterized in that, The circulating refrigeration unit includes: a compressor, a cooler, a regenerator, and a turboexpander; The compressor outlet is connected to the cold end inlet of the cooler, and is used to compress the refrigerant flowing into the compressor and deliver the compressed refrigerant to the cooler. The cold end outlet of the cooler is connected to the cold end inlet of the regenerator, which is used to cool down the refrigerant flowing out of the compressor and then deliver the cooled refrigerant to the regenerator. The cold end outlet of the regenerator is connected to the inlet of the turbine expander, and the hot end inlet is connected to the outlet of the cold screen. It is used to cool the refrigerant flowing out of the cooler with the refrigerant flowing out of the cold screen, and then return the refrigerant from the cold screen to the hot end inlet of the cooler. The refrigerant from the cold end outlet of the cooler is delivered to the inlet of the turbine expander. The refrigerant flowing into the hot end inlet of the cooler flows out through the hot end outlet of the cooler and flows into the inlet of the compressor. The outlet of the turbine expander is connected to the inlet of the cold screen, and is used to expand and cool the refrigerant flowing out of the regenerator, and then transport the expanded and cooled refrigerant to the cold screen.

6. The system according to claim 1, characterized in that, Also includes: The injection pipe is connected to the storage tank and is used to deliver cryogenic propellant into the storage tank; A drain pipe, connected to the storage tank, is used to drain the cryogenic propellant from the storage tank.

7. The system according to claim 6, characterized in that, Also includes: A first solenoid valve is installed on the injection pipe and is used to adjust the flow rate of the cryogenic propellant delivered by the injection pipe. A second solenoid valve is installed on the drain pipe and is used to adjust the flow rate of the cryogenic propellant discharged from the drain pipe.

8. An application method for a liquid cryogenic propellant overturning test system, characterized in that, Applied to the system according to any one of claims 1-7, comprising: The storage tank stores the cryogenic propellant required for engine propulsion. The refrigeration component uses a refrigerant to cool the cryogenic propellant stored in the tank, so that the volume ratio of liquid cryogenic propellant to gaseous cryogenic propellant stored in the tank reaches a preset threshold. The accumulator stores a portion of the cryogenic propellant stored in the tank within the accumulator, and when the cryogenic propellant in the tank separates from the engine, the internally stored cryogenic propellant is supplied to the engine. The first pressure value of the cryogenic propellant at the bottom of the tank is measured by a pressure sensor located at the bottom of the tank. The tank is flipped by the flipping assembly, allowing the cryogenic propellant stored in the accumulator to flow back into the tank; The second pressure value of the cryogenic propellant at the bottom of the tank is measured by a pressure sensor located at the bottom of the tank after it has been overturned. The performance of the storage tank is tested based on the first pressure value and the second pressure value.

9. The application method according to claim 8, characterized in that, The performance test of the storage tank based on the first pressure value and the second pressure value includes: Based on the first pressure value, the density and pressure formula of the cryogenic propellant, the first storage volume of the cryogenic propellant in the tank before overturning is obtained; Based on the second pressure value, the density and pressure formula of the cryogenic propellant, the second storage volume of the cryogenic propellant in the tank after the overturning is obtained; Based on the first and second storage volumes, the third storage volume of the accumulator when storing cryogenic propellant is obtained.

10. The application method according to claim 8, characterized in that, The system also includes an injection pipe and a drain pipe, which are respectively connected to the storage tank; Cryogenic propellant is delivered into the storage tank through the injection pipe; The cryogenic propellant in the storage tank is discharged through the drain pipe.

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