A hydrogen and magnesium releasing system for a bimodal consubstantial space propulsion system

Abstract

This invention belongs to the field of dual-mode comass space propulsion technology, and particularly relates to a magnesium hydride hydrogen and magnesium release system for a dual-mode comass space propulsion system, comprising a nuclear electric thruster, a magnesium hydride storage tank, a nuclear reactor, and a nuclear thermal thruster. Utilizing the high temperature of the nuclear reactor, the magnesium hydride storage tank is heated by controlling the temperature of He gas, pyrolyzing the magnesium hydride into hydrogen and magnesium, providing hydrogen for the nuclear thermal thruster. After the hydrogen release from the magnesium hydride storage tank is largely complete, the residual hydrogen in the tank is completely emptied through a hydrogen venting valve. The magnesium in the tank is then melted by heating with He gas, and the surface tension of the liquid magnesium is used to achieve controlled release of liquid magnesium, providing liquid magnesium for the nuclear electric thruster. This achieves controlled hydrogen and magnesium release in the magnesium hydride hydrogen and magnesium release system, enabling the application of a nuclear-electric and nuclear-thermal dual-mode comass propulsion system for spacecraft.

Description

Technical Field

[0001] This invention belongs to the field of dual-mode comass space propulsion technology, and particularly relates to a magnesium hydride hydrogen release and magnesium release system for dual-mode comass space propulsion systems. Background Technology

[0002] The current chemical combustion propulsion method for spacecraft is gradually failing to meet the requirements of high energy density, high specific impulse, long duration, and long distance deep space flight and exploration missions. Space nuclear propulsion will become the main power source for future deep space probes. Currently, space nuclear propulsion mainly includes two types: nuclear thermal propulsion and nuclear electric propulsion. (1) Nuclear thermal propulsion refers to using the heat released by nuclear reaction to heat the propellant to above 2500K, and then ejecting it in the nozzle to obtain thrust. It has the advantage of high thrust-to-weight ratio, but the specific impulse is relatively small (800-1000s). (2) Nuclear electric propulsion refers to converting the heat released by the nuclear reactor into thermoelectricity, and then driving a high-power electric thruster to accelerate charged particles under the action of an electromagnetic field to obtain thrust. It has the advantage of high specific impulse (3000-10000s), but the thrust-to-weight ratio is relatively low and the thrust is small. Therefore, in order to meet the demand for high thrust and high specific impulse power in the complex space environment of deep space exploration, it is urgent to study nuclear thermal-nuclear power dual-mode propulsion technology, which can switch the working mode according to the power needs of the mission and realize the efficient propulsion of spacecraft.

[0003] Hydrogen, due to its small molecular weight, is commonly used as the working fluid in nuclear thermal propulsion. Current technologies primarily employ liquid hydrogen for storage. However, this method suffers from drawbacks such as excessively low storage temperatures (~20K) and the volatile nature of liquid hydrogen. Therefore, it necessitates the use of insulation materials to reduce heat leakage or cryogenic refrigerators (with an efficiency of <5%) for heat removal. These additional insulation structures beyond the liquid hydrogen working fluid itself increase system complexity, structural weight, and power consumption, making it difficult to meet the operational requirements of nuclear-powered aircraft with a lifespan of 5-10 years or even longer. Therefore, nuclear thermal propulsion requires a hydrogen storage technology that enables long-term safe storage and efficient release of hydrogen.

[0004] Nuclear propulsion utilizes a variety of working fluids, including solid working fluids such as lithium, magnesium, zinc, bismuth, and iodine; liquid working fluids such as mercury, cesium, and ammonia; and gaseous working fluids such as argon, krypton, and xenon. Currently, existing spacecraft use xenon as their working fluid, which suffers from low volumetric density in high-pressure storage tanks and high safety risks. Solid working fluids generally offer higher storage density and are safer and more convenient. International research has been conducted on solid working fluids other than xenon, comparing specific impulse, velocity increment, and storage density, revealing that some metallic working fluids have performance advantages over xenon. The future development direction for nuclear propulsion is towards solid working fluids, especially Mg (whose specific impulse can reach 2.3 times that of xenon), which can achieve even higher specific impulse.

[0005] In summary, hydrogen is a typical propellant for space nuclear thermal propulsion, while magnesium is a suitable solid working fluid for nuclear electric propulsion. MgH2 is a high-density, long-term storable hydrogen storage material with a hydrogen storage density of up to 7.6 wt.%, higher than that of high-pressure hydrogen and liquid hydrogen storage. Simultaneously, the hydrogen release products are only H2 and Mg, making it suitable as a working fluid for nuclear thermal and nuclear electric propulsion, respectively. Lin Qingguo et al. from the Shanghai Space Propulsion Institute conducted theoretical research on dual-mode comass propulsion technology based on magnesium hydride. Their results show that continuous propulsion using magnesium hydride through simultaneous decomposition and heating results in a maximum thrust of 1196 N (~120 N / MWe) due to limited thermal power. However, if the decomposed hydrogen is stored in a buffer tank, a large thrust can be provided through long pulses, thus achieving even higher thrust. If magnesium nuclear electric propulsion is used, a specific impulse of over 7000 s can be obtained, but the thrust is only 14 N / MWe. These results provide preliminary theoretical evidence for the feasibility of dual-mode comass propulsion technology based on magnesium hydride from an energy perspective.

[0006] However, there are currently no publicly available reports on how to utilize magnesium hydride materials to design a suitable magnesium hydride hydrogen and magnesium storage system with controlled hydrogen and magnesium release capabilities, enabling the supply of high-pressure hydrogen and liquid magnesium to the nuclear power / nuclear thermal dual-mode comass propulsion system of spacecraft. Existing magnesium hydride storage tank designs are geared towards civilian hydrogen storage and supply applications on the ground, with hydrogen release temperatures <400℃ and release pressures <1MPa. These designs are unsuitable for the high-temperature, high-pressure hydrogen (≥450℃, 4-8MPa) requirements of nuclear thermal propulsion under microgravity conditions in space. Furthermore, since liquid magnesium floats under microgravity conditions, its flow is difficult to control, and nuclear power propulsion cannot contain hydrogen. Therefore, how to completely release the hydrogen from magnesium hydride and controllably supply liquid magnesium to the nuclear power propulsion system is also a key aspect of designing a magnesium hydride hydrogen and magnesium release system. Summary of the Invention

[0007] To address the aforementioned problems, the inventors designed a He gas heat transfer pipe and inner and outer guide plates in the magnesium hydride storage tank. On the one hand, this increases the thermal conductivity and enhances the hydrogen release rate of magnesium hydride; on the other hand, under the action of the surface tension of liquid magnesium, it enables the controllable flow of liquid magnesium along the guide plates, thereby achieving the controllable release of hydrogen and magnesium from the magnesium hydride storage tank, thus completing the present invention.

[0008] Therefore, in one aspect, the present invention provides a magnesium hydride hydrogen and magnesium release system for a dual-mode comass space propulsion system, comprising a nuclear electric thruster, a magnesium hydride storage tank, a nuclear reactor, and a nuclear thermal thruster. The magnesium hydride storage tank is connected to the nuclear reactor via a He loop flowing through it. The He loop includes a He gas heat transfer pipe, a He circulation pump, a He gas inlet valve, and a He gas outlet valve. The nuclear electric thruster and the magnesium hydride storage tank are connected via a liquid magnesium pipeline. The magnesium hydride storage tank and the nuclear thermal thruster are connected via a hydrogen pipeline.

[0009] In a preferred embodiment, the magnesium hydride hydrogen release system for the dual-mode comass space propulsion system comprises multiple magnesium hydride storage tanks connected in parallel, preferably 5-8 magnesium hydride storage tanks connected in parallel.

[0010] In a preferred embodiment, the magnesium hydride storage tank is provided with an inner guide plate and an outer guide plate. More preferably, each magnesium hydride storage tank is provided with four curved inner and outer guide plates. Most preferably, the inner and outer guide plates are made of stainless steel. The inner and outer guide plates are configured for flow control of liquid magnesium within the magnesium hydride storage tank under microgravity conditions in space.

[0011] In a preferred embodiment, the He gas heat transfer pipe is located inside the magnesium hydride storage tank, between the inner and outer guide plates, and does not directly contact them, for heating magnesium hydride and solid magnesium particles. More preferably, the He gas heat transfer pipe is spiral or U-shaped; more preferably, the magnesium hydride storage tank contains multiple He gas heat transfer pipes, for example, three U-shaped He gas heat transfer pipes.

[0012] In a preferred embodiment, the magnesium hydride storage tank is equipped with a He gas inlet valve and a He gas outlet valve. In another preferred embodiment, the magnesium hydride storage tank is further provided with a porous column to serve as a flow channel for liquid magnesium.

[0013] In a preferred embodiment, the liquid magnesium pipeline is equipped with a liquid magnesium metering and controller, a liquid magnesium valve, and an electromagnetic pump.

[0014] In a preferred embodiment, the hydrogen pipeline is equipped with a hydrogen valve, a buffer tank, a hydrogen meter and controller, and a hydrogen discharge valve.

[0015] In a preferred embodiment, the magnesium hydride storage tank contains magnesium hydride material, preferably high-purity magnesium hydride, i.e., magnesium hydride with a purity of 99% or higher. The magnesium hydride material is in the form of pressed blocks / granules or powder, and is uniformly filled into the magnesium hydride storage tank by means of vibration compaction or external force compaction on the ground.

[0016] In another aspect, the present invention provides a method for the release of magnesium hydride and magnesium for a dual-mode comass space propulsion system, the method comprising:

[0017] S1: He gas is heated to 470-600°C using a nuclear reactor, and magnesium hydride in the magnesium hydride storage tank is heated using the He gas heat transfer tube in the He circuit.

[0018] S2: The magnesium hydride storage tank decomposes hydrogen upon heating and supplies hydrogen to the nuclear thermal propulsion unit at a pressure of 4-8 MPa.

[0019] S3: After the magnesium hydride storage tank has finished releasing hydrogen, the remaining gaseous hydrogen in the magnesium hydride storage tank is discharged through the hydrogen discharge valve, and the residual magnesium hydride is decomposed until the hydrogen pressure in the magnesium hydride storage tank drops to below 0.1 Pa.

[0020] S4: Use a nuclear reactor to heat He gas to above 650°C, so that the solid magnesium particles in the magnesium hydride storage tank melt.

[0021] S5: Using an electromagnetic pump, the liquid magnesium released from the magnesium hydride storage tank is supplied to the nuclear electric propulsion unit.

[0022] In a preferred embodiment, the heating temperature of He gas in S1 does not exceed 600°C, and the actual heating temperature T is calculated using the following formula:

[0023]

[0024] Wherein, ΔH = 74400 J / mol H2, which represents the enthalpy change of the magnesium hydride hydrogen release reaction; ΔS = 135 J / mol / K H2, which represents the entropy change of the magnesium hydride hydrogen release reaction; C is the temperature correction coefficient; P is the hydrogen release pressure (MPa); and R = 8.314 J / mol / K, which represents the standard gas constant. Preferably, C is 30–120 °C, and its value depends on the hydrogen supply rate requirements of the nuclear thermal propulsion unit, as well as the size and structure of the magnesium hydride storage tank.

[0025] In a preferred embodiment, when hydrogen is supplied at a pressure of 4 MPa in S2, He gas needs to be heated to 520°C in S1; when hydrogen is supplied at a pressure of 8 MPa in S2, He gas needs to be heated to 581°C in S1.

[0026] In a preferred embodiment, in step S4, the He gas is heated to 670-720°C.

[0027] Technical effect

[0028] (1) The present invention designs a He gas heat transfer pipe and inner and outer guide plates in the magnesium hydride storage tank. On the one hand, it increases the thermal conductivity and enhances the hydrogen release rate of magnesium hydride. On the other hand, under the action of the surface tension of liquid magnesium, it realizes the controllable flow of liquid magnesium along the guide plates, thereby realizing the controllable release of hydrogen and magnesium from the magnesium hydride storage tank. This solves the problem that the liquid magnesium in the existing ground-based magnesium hydride storage tank moves disorderly and cannot be controlled in the microgravity environment of space. After the magnesium hydride storage tank releases hydrogen at high temperature and high pressure, the liquid magnesium can provide magnesium propulsion medium for nuclear power propulsion.

[0029] (2) Based on the numerical simulation results and the hydrogen release equilibrium pressure of magnesium hydride, this invention provides a suitable hydrogen release temperature range, which avoids the melting of magnesium during hydrogen release and releases the hydrogen in magnesium hydride as quickly and completely as possible, thereby achieving effective hydrogen release from the magnesium hydride storage tank.

[0030] (3) Due to the high hydrogen release pressure of the magnesium hydride storage tank, it is impossible to completely decompose the magnesium hydride. This invention solves the problem of residual hydrogen between hydrogen release and magnesium release through process design, and realizes the controllable hydrogen release and magnesium release of the magnesium hydride storage tank.

[0031] In summary, this invention provides a magnesium hydride hydrogen and magnesium release system and its usage method for a dual-mode comass space propulsion system. Utilizing the high-temperature heat of a nuclear reactor, the magnesium hydride storage tank is heated by controlling the temperature of He gas, pyrolyzing the magnesium hydride into hydrogen and magnesium to provide hydrogen for the nuclear thermal propulsion unit. After the hydrogen release from the magnesium hydride storage tank is largely complete, the residual hydrogen in the tank is completely emptied through a hydrogen venting valve. The magnesium in the tank is then melted by heating with He gas, and the surface tension of the liquid magnesium is used to achieve controlled release of liquid magnesium to provide liquid magnesium for the nuclear electric propulsion unit. This enables the controlled hydrogen and magnesium release of the magnesium hydride hydrogen and magnesium release system, facilitating its application in a nuclear-electric / nuclear-thermal dual-mode comass propulsion system for spacecraft.

[0032] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a magnesium hydride hydrogen release and magnesium release system according to a preferred embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the magnesium hydride storage tank structure according to a preferred embodiment of the present invention;

[0035] Reference numerals in the attached diagram: 1. Magnesium hydride storage tank; 2. Hydrogen valve; 3. Buffer tank; 4. Hydrogen metering and controller; 5. Nuclear thermal thruster; 6. Hydrogen discharge valve; 7. Liquid magnesium valve; 8. Electromagnetic pump; 9. Liquid magnesium metering and controller; 10. Nuclear electric thruster; 11. He gas outlet valve; 12. He gas inlet valve; 13. He gas circulation pump; 14. Nuclear reactor; 15. He gas heat transfer pipe; 16. Inner guide plate; 17. Outer guide plate; 18. Porous column; 19. Outer wall of the storage tank; 20. Magnesium hydride; 21. Hydrogen valve of the storage tank; 22. Liquid magnesium valve of the storage tank; 23. He gas inlet valve of the storage tank; 24. He gas outlet valve of the storage tank. Detailed Implementation

[0036] The following description, with reference to the accompanying drawings, illustrates several preferred embodiments of the present invention to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0037] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of some components has been appropriately exaggerated in the drawings.

[0038] Example 1

[0039] Magnesium hydride hydrogen release and magnesium release systems for dual-mode comass space propulsion systems, such as Figure 1 As shown, the system includes a nuclear electric thruster 10, a magnesium hydride storage tank 1, a nuclear reactor 14, and a nuclear thermal thruster 5. The magnesium hydride storage tank 1 is connected to the nuclear reactor 14 via a He loop flowing through it. The He loop includes a He gas heat transfer pipe 15, a He circulation pump 13, a He gas inlet valve 12, and a He gas outlet valve 11. The nuclear electric thruster 10 and the magnesium hydride storage tank 1 are connected via a liquid magnesium pipeline. The liquid magnesium pipeline is equipped with a liquid magnesium metering and controller 9, a liquid magnesium valve 7, and an electromagnetic pump 8. The magnesium hydride storage tank 1 and the nuclear thermal thruster 5 are connected via a hydrogen pipeline. The hydrogen pipeline is equipped with a hydrogen valve 2, a buffer tank 3, a hydrogen metering and controller 4, and a hydrogen discharge valve 6.

[0040] The magnesium hydride release system for the dual-mode coherent space propulsion system comprises five magnesium hydride storage tanks 1. Each magnesium hydride storage tank is uniformly filled with 200 kg of high-purity magnesium hydride powder on the ground using external force compaction. The magnesium hydride storage tanks 1 are as follows... Figure 2 As shown, the tank contains four stainless steel outer guide plates 17 and inner guide plates 16 with a certain curvature, used for flow control of liquid magnesium in the magnesium hydride storage tank 1 under microgravity conditions. A porous column 18 serves as a flow channel for the liquid magnesium. A spiral-shaped He gas heat transfer pipe 15 is installed inside the magnesium hydride storage tank 1, located between the outer guide plates 17 and the inner guide plates 16, without direct contact with them, for heating the magnesium hydride 20 and solid magnesium particles. The magnesium hydride storage tank 1 is also equipped with a He gas inlet valve 23, a He gas outlet valve 24, a hydrogen valve 21, and a liquid magnesium valve 24.

[0041] He gas circulates between nuclear reactor 14, He circulation pump 13, He inlet valve 12, He gas inlet valve 23 of storage tank, He gas heat transfer pipe 15, He gas outlet valve 24 of storage tank, and He gas outlet valve 11, continuously heating magnesium hydride storage tank 1 using the heat from nuclear reactor 14. During the hydrogen release phase of magnesium hydride storage tank 1, the tank is heated by He, and the stored magnesium hydride 20 decomposes upon heating, producing hydrogen gas and solid magnesium particles. Hydrogen gas enters the nuclear thermal propulsion unit 5 at a pressure of 4 MPa through storage tank hydrogen valve 21, hydrogen valve 2, buffer tank 3, and hydrogen metering and controller 4. Based on the hydrogen supply rate requirements of the nuclear thermal thruster 5 and the size and structure of the magnesium hydride storage tank, the C value is taken as 80℃, and the temperature of He gas to be controlled is calculated to be 520℃ according to the following formula (ΔS=135J / mol / K H2, ΔH=74400J / mol H2, P=4MPa, C=80℃, R=8.314J / mol / K).

[0042]

[0043] When the hydrogen release rate of magnesium hydride storage tank 1 under a hydrogen release pressure of 4 MPa cannot meet the minimum rate requirement of 1 Nm³ for nuclear thermal propulsion... 3 When the flow rate reaches a certain threshold ( / min), it can be determined that hydrogen release from magnesium hydride storage tank 1 is complete, and magnesium hydride storage tank 1 enters the magnesium release stage. Before magnesium release, the remaining gaseous hydrogen in magnesium hydride storage tank 1 is discharged through the hydrogen discharge valve, and the residual magnesium hydride 20 is decomposed until the hydrogen pressure in magnesium hydride storage tank 1 drops below 0.1 Pa, leaving only solid magnesium particles. By adjusting the He circulation flow rate, the He gas temperature is increased to 720℃, heating and melting the solid magnesium particles in magnesium hydride storage tank 1 to form liquid magnesium. This liquid magnesium then enters the nuclear power thruster 10 through the liquid magnesium valve 7, electromagnetic pump 8, and liquid magnesium metering and controller 9, providing the working fluid for the nuclear power thruster 10. In summary, the basic steps of hydrogen and magnesium release from the magnesium hydride storage tank are as follows:

[0044] S1: Nuclear reactor 14 heats He gas to 520°C and uses He gas circulation to heat magnesium hydride storage tank 1;

[0045] S2: Magnesium hydride storage tank 1 decomposes hydrogen by heating and supplies hydrogen to nuclear thermal propulsion unit 5 at a pressure of 4MPa;

[0046] S3: After the magnesium hydride storage tank 1 has finished releasing hydrogen, the remaining gaseous hydrogen in the magnesium hydride storage tank 1 is discharged through the hydrogen discharge valve 6, and the residual magnesium hydride is decomposed until the hydrogen pressure in the magnesium hydride storage tank 1 drops to below 0.1 Pa.

[0047] S4: Using nuclear reactor 14, the He gas is heated to 720°C to melt the solid magnesium particles in magnesium hydride storage tank 1;

[0048] S5: Magnesium hydride storage tank 1 releases magnesium to supply liquid magnesium to nuclear power thruster 10.

[0049] Example 2

[0050] Magnesium hydride hydrogen release and magnesium release systems for dual-mode comass space propulsion systems, such as Figure 1 As shown, the system includes a nuclear electric thruster 10, a magnesium hydride storage tank 1, a nuclear reactor 14, and a nuclear thermal thruster 5. The magnesium hydride storage tank 1 is connected to the nuclear reactor 14 via a He loop flowing through it. The He loop includes a He gas heat transfer pipe 15, a He circulation pump 13, a He gas inlet valve 12, and a He gas outlet valve 11. The nuclear electric thruster 10 and the magnesium hydride storage tank 1 are connected via a liquid magnesium pipeline. The liquid magnesium pipeline is equipped with a liquid magnesium metering and controller 9, a liquid magnesium valve 7, and an electromagnetic pump 8. The magnesium hydride storage tank 1 and the nuclear thermal thruster 5 are connected via a hydrogen pipeline. The hydrogen pipeline is equipped with a hydrogen valve 2, a buffer tank 3, a hydrogen metering and controller 4, and a hydrogen discharge valve 6.

[0051] The magnesium hydride hydrogen release system for the dual-mode coherent space propulsion system comprises eight magnesium hydride storage tanks 1. Each magnesium hydride storage tank is uniformly filled with 100 kg of high-purity magnesium hydride powder, pressed into a block shape, using a vibratory compaction method on the ground. Each magnesium hydride storage tank 1 is equipped with four stainless steel outer guide plates 17 and inner guide plates 16 with a certain curvature for controlling the flow of liquid magnesium within the tank under microgravity conditions. Porous columns 18 are provided as flow channels for the liquid magnesium. Three U-shaped He gas heat transfer pipes 15 are installed inside each magnesium hydride storage tank 1, located between the outer guide plates 17 and inner guide plates 16, without direct contact with them, for heating magnesium hydride 20 and solid magnesium particles. Each magnesium hydride storage tank 1 is also equipped with a He gas inlet valve 23, a He gas outlet valve 24, a hydrogen valve 21, and a liquid magnesium valve 24.

[0052] He gas circulates between the nuclear reactor 14, He circulation pump 13, He inlet valve 12, He gas inlet valve 23 of the storage tank, He gas heat transfer pipe 15, He gas outlet valve 24 of the storage tank, and He gas outlet valve 11, continuously heating the magnesium hydride storage tank 1 using the heat from the nuclear reactor 14. During the hydrogen release phase of the magnesium hydride storage tank 1, the tank is heated by He, and the stored magnesium hydride 20 decomposes upon heating, producing hydrogen gas and solid magnesium particles. Hydrogen gas enters the nuclear thermal propulsion unit 5 at a pressure of 8 MPa through the storage tank hydrogen valve 21, hydrogen valve 2, buffer tank 3, and hydrogen metering and controller 4. Based on the hydrogen supply rate requirements of nuclear thermal thruster 5 and the size and structure of the magnesium hydride storage tank, the value of C is taken as 110℃, and the temperature of He gas to be controlled is calculated to be 581℃ according to the following formula (ΔS=135J / mol / K H2, ΔH=74400J / mol H2, P=8MPa, C=100℃, R=8.314J / mol / K).

[0053]

[0054] When the hydrogen release rate of magnesium hydride storage tank 1 under a hydrogen release pressure of 8 MPa cannot meet the minimum rate requirement of 0.2 Nm for the nuclear thermal propulsion system... 3 When the flow rate reaches a certain threshold (e.g., a certain velocity), it can be determined that hydrogen release from magnesium hydride storage tank 1 is complete, and the tank enters the magnesium release stage. Before magnesium release, the remaining gaseous hydrogen in magnesium hydride storage tank 1 is discharged through the hydrogen discharge valve, and the residual magnesium hydride 20 is decomposed until the hydrogen pressure in magnesium hydride storage tank 1 drops below 0.1 Pa, leaving only solid magnesium particles. By adjusting the He circulation flow rate, the He gas temperature is increased to 670℃, heating and melting the solid magnesium particles in magnesium hydride storage tank 1 to form liquid magnesium. This liquid magnesium then enters the nuclear power thruster 10 through the liquid magnesium valve 7, electromagnetic pump 8, and liquid magnesium metering and controller 9, providing the working fluid for the nuclear power thruster 10. In summary, the basic steps of hydrogen and magnesium release from the magnesium hydride storage tank are as follows:

[0055] S1: Nuclear reactor 14 heats He gas to 581°C and uses He gas circulation to heat magnesium hydride storage tank 1;

[0056] S2: Magnesium hydride storage tank 1 decomposes hydrogen by heating and supplies hydrogen to nuclear thermal propulsion unit 5 at a pressure of 8 MPa;

[0057] S3: After the magnesium hydride storage tank 1 has finished releasing hydrogen, the remaining gaseous hydrogen in the magnesium hydride storage tank 1 is discharged through the hydrogen discharge valve 6, and the residual magnesium hydride is decomposed until the hydrogen pressure in the magnesium hydride storage tank 1 drops to below 0.1 Pa.

[0058] S4: Using nuclear reactor 14, the He gas is heated to 670°C to melt the solid magnesium particles in magnesium hydride storage tank 1;

[0059] S5: Magnesium hydride storage tank 1 releases magnesium to supply liquid magnesium to nuclear power thruster 10.

[0060] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for releasing magnesium hydride hydrogen and magnesium for a dual-mode coherent space propulsion system, wherein the system used in the microgravity environment of space includes a nuclear electric thruster, a magnesium hydride storage tank, a nuclear reactor, and a nuclear thermal thruster. The magnesium hydride storage tank is connected to the nuclear reactor via a He loop flowing through it. The He loop includes a He gas heat transfer pipe, a He circulation pump, a He gas inlet valve, and a He gas outlet valve. The nuclear electric thruster and the magnesium hydride storage tank are connected via a liquid magnesium pipeline. The magnesium hydride storage tank and the nuclear thermal thruster are connected via a hydrogen pipeline. An inner guide plate and an outer guide plate are provided inside the magnesium hydride storage tank. The method includes: S1: He gas is heated to 470℃-600℃ using a nuclear reactor, and magnesium hydride in the magnesium hydride storage tank is heated using the He gas heat transfer tube in the He circuit. S2: The magnesium hydride storage tank decomposes hydrogen upon heating and supplies hydrogen to the nuclear thermal propulsion unit at a pressure of 4-8 MPa. S3: After the magnesium hydride storage tank has finished releasing hydrogen, the remaining gaseous hydrogen in the magnesium hydride storage tank is discharged through the hydrogen discharge valve, and the residual magnesium hydride is decomposed until the hydrogen pressure in the magnesium hydride storage tank drops to below 0.1 Pa. S4: Use a nuclear reactor to heat He gas to above 650°C, so that the solid magnesium particles in the magnesium hydride storage tank melt. S5: Using an electromagnetic pump, the liquid magnesium released from the magnesium hydride storage tank is supplied to the nuclear electric thruster; The heating temperature T of He gas in S1 is calculated using the following formula: Wherein, ΔH = 74400 J / mol H2, which means the enthalpy change of the magnesium hydride hydrogen release reaction; ΔS = 135 J / mol / K H2, which means the entropy change of the magnesium hydride hydrogen release reaction; C is the temperature correction coefficient; P is the hydrogen release pressure (MPa); R = 8.314 J / mol / K, which means the standard gas constant.

2. The method for releasing hydrogen and magnesium from magnesium hydride according to claim 1, wherein, The system comprises multiple magnesium hydride storage tanks connected in parallel.

3. The method for releasing hydrogen and magnesium from magnesium hydride according to claim 1, wherein, The inner and outer guide vanes are made of stainless steel.

4. The method for releasing hydrogen and magnesium from magnesium hydride according to claim 1, wherein, The He gas heat transfer pipe is located inside the magnesium hydride storage tank, between the inner guide plate and the outer guide plate, and does not directly contact the inner guide plate and the outer guide plate.

5. The method for releasing hydrogen and magnesium from magnesium hydride according to claim 4, wherein, The He gas heat transfer tube is spiral or U-shaped.

6. The method for releasing hydrogen and magnesium from magnesium hydride according to claim 1, wherein, The liquid magnesium pipeline is equipped with a liquid magnesium metering and controller, a liquid magnesium valve, and an electromagnetic pump.

7. The method for releasing hydrogen and magnesium from magnesium hydride according to claim 1, wherein, The hydrogen pipeline is equipped with a hydrogen valve, a buffer tank, a hydrogen meter and controller, and a hydrogen discharge valve.

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