Normal-temperature aluminum-water metal fuel propellant and preparation method thereof

Abstract

The application provides a normal-temperature aluminum water metal fuel propellant and a preparation method thereof, and belongs to the technical field of solid propellants. The application uses aluminum powder as fuel, which can save the cost of propellant and improve the energy characteristics of the propellant. The application uses aluminum hydride as a fuel additive, which increases the hydrogen content in the fuel, reduces the flame temperature of the propellant, and improves the specific impulse of the propellant. The application uses perchlorate and sodium sulfate hydrate as an oxidizing agent. The sodium sulfate hydrate stores water in the form of crystal water in the propellant, which overcomes the disadvantage that the aluminum / ice propellant needs to be stored at low temperature. Under normal temperature conditions, the sodium sulfate hydrate has good stability and is not easy to decompose or lose crystal water, thereby prolonging the service life of the propellant. In the combustion process, the sodium sulfate hydrate can be dehydrated to provide an oxidizing agent for the propellant and can be decomposed to generate a working medium, thereby improving the specific impulse of the propellant.

Description

Technical Field

[0001] This invention belongs to the field of solid propellant technology, specifically relating to a room-temperature molten aluminum metal fuel propellant and its preparation method. Background Technology

[0002] Aluminum is the most abundant metal on Earth. Due to its advantages of high energy density, low price, stable chemical properties, non-toxicity, and large amount of hydrogen produced during reaction, it has potential applications in energy storage and transportation. Aluminum can release a large amount of energy when it reacts with water or ice, so it can provide power for underwater and space aerospace systems. Aluminum-ice solid propellant is made by mixing nano-aluminum powder with water to form a slurry with a viscosity similar to clay, and then filling it into a mold and cooling it to about -28°C. The purpose of freezing the aluminum / water mixture is to prevent aluminum particles from reacting with water. Compared with traditional propellants, aluminum-ice solid propellant has the following characteristics: (1) It is simple to manufacture and has no requirements for the manufacturing location, as long as there is a water source, aluminum powder, and mixing equipment; (2) It is safe to use, with a low probability of accidental ignition and negligible danger from electrostatic discharge; (3) The combustion products of aluminum-ice solid propellant are hydrogen and aluminum oxide, which have relatively low toxicity and are pollution-free; (4) It has low production costs.

[0003] However, the storage requirements of aluminum ice propellants are strictly dependent on cryogenic environments, which introduces additional complexity and increases related costs. Because of the extremely high chemical reactivity of nano-aluminum powder, it must be passivated before contact with water. Furthermore, the storage conditions for solid aluminum ice propellants are demanding; aluminum ice mixtures can be stored for over 200 days at -25°C, but only for a few days at room temperature. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a room-temperature molten aluminum metal fuel propellant and its preparation method. This invention enables the safe storage of the metal fuel propellant at room temperature, and the resulting room-temperature molten aluminum metal fuel propellant has good combustion performance and energy characteristics.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a room-temperature aluminum-water metal fuel propellant, comprising fuel, fuel additives, and an oxidant. The fuel comprises aluminum powder, the fuel additives comprise aluminum trihydride, and the oxidant comprises sodium sulfate hydrate and perchlorate.

[0007] Preferably, the room-temperature molten aluminum metal fuel propellant comprises the following components in weight percentage:

[0008] Aluminum powder: 35~45%;

[0009] Aluminum trihydride: 8~12%;

[0010] Sodium sulfate hydrate: 35~45%;

[0011] Perchlorate: 8~10%.

[0012] Preferably, the aluminum powder includes ultrafine aluminum powder and conventional aluminum powder; the particle size of the ultrafine aluminum powder is 100 nm to 1 μm; the particle size of the conventional aluminum powder is 1 to 100 μm, excluding 1 μm.

[0013] Preferably, the mass ratio of ultrafine aluminum powder in the aluminum powder is ≤60%.

[0014] Preferably, the aluminum trihydride has a particle size of 1~100μm.

[0015] Preferably, the particle size of the sodium sulfate hydrate is 1~100μm.

[0016] Preferably, the sodium sulfate hydrate includes one or more of sodium sulfate decahydrate, sodium sulfate heptahydrate, and sodium sulfate dodecahydrate.

[0017] Preferably, the perchlorate includes potassium perchlorate or ammonium perchlorate.

[0018] This invention also provides a method for preparing the room-temperature molten aluminum metal fuel propellant described in the above technical solution, comprising the following steps:

[0019] The fuel, fuel additives, and oxidant are mixed and pressed in sequence to obtain the room-temperature aluminum molten metal fuel propellant.

[0020] Preferably, the mixing method includes grinding; after grinding, the resulting material is preferably screened; the pressing is preferably performed using a press, and the pressing pressure is preferably 200 MPa.

[0021] This invention provides a room-temperature aluminum-ice metal fuel propellant, comprising fuel, fuel additives, and an oxidant. The fuel comprises aluminum powder, the fuel additive comprises aluminum trihydride, and the oxidant comprises sodium sulfate hydrate and perchlorate. This invention uses aluminum powder, aluminum trihydride, sodium sulfate hydrate, and perchlorate, all of which are abundant and readily available. The use of aluminum powder as the main fuel is advantageous due to its high energy density, low cost, availability, and good combustion stability, thus saving propellant costs and improving its energy characteristics. Aluminum trihydride is used as the fuel additive, generating more combustion products and working fluid during combustion, thereby increasing the propellant's thrust. Simultaneously, aluminum trihydride increases the combustion stability of aluminum powder, reducing instability and violent oscillations during combustion, and improving the reliability of the propulsion system. The use of water of crystallization from sodium sulfate hydrate as the oxidant solves the problem of requiring aluminum ice propellant to be stored in a low-temperature environment, reducing storage costs. Furthermore, sodium sulfate decomposes during propellant combustion to generate working fluid, effectively increasing the specific impulse and improving propellant performance. Sodium sulfate hydrate has advantages such as simple preparation process, stable chemical properties, low cost, high water of crystallization content, and easy storage. It not only solves the temperature sensitivity problem faced by traditional aluminum ice propellants but also achieves safe storage at room temperature, while improving propulsion efficiency and performance, showing broad application prospects in the modern aerospace field. The results of the examples show that the room-temperature aluminum hydrate metal fuel propellant obtained by this invention significantly reduces propellant cost and improves specific impulse and storage performance.

[0022] This invention also provides a method for preparing the room-temperature molten aluminum metal fuel propellant described in the above technical solution, comprising the following steps: sequentially mixing and pressing fuel, fuel additives, and oxidant to obtain the room-temperature molten aluminum metal fuel propellant. This invention employs a pressing molding process, which is simple to manufacture and exhibits good storage stability. Detailed Implementation

[0023] This invention provides a room-temperature aluminum-water metal fuel propellant, comprising fuel, fuel additives, and an oxidant. The fuel comprises aluminum powder, the fuel additives comprise aluminum trihydride, and the oxidant comprises sodium sulfate hydrate and perchlorate.

[0024] In this invention, unless otherwise specified, all components are commercially available products well known to those skilled in the art.

[0025] The room-temperature molten aluminum metal fuel propellant provided by this invention, by mass percentage, preferably comprises 35-45% aluminum powder, more preferably 36-41%, and even more preferably 38%. In this invention, the aluminum powder preferably comprises ultrafine aluminum powder and conventional aluminum powder; the particle size of the ultrafine aluminum powder is preferably 100 nm to 1 μm, more preferably 500 nm; the particle size of the conventional aluminum powder is preferably 1-100 μm, excluding 1 μm, and more preferably 50 μm. In this invention, the mass ratio of ultrafine aluminum powder in the aluminum powder is preferably ≤60%. In this invention, ultrafine aluminum powder replaces a portion of the conventional aluminum powder, thereby obtaining a composite aluminum powder with different particle diameters. The ultrafine aluminum powder can improve the mixability of the propellant, increase the contact area between propellant particles, and improve combustion efficiency and thrust. During propellant combustion, the use of ultrafine aluminum powder can increase the heat transfer efficiency of the combustion zone, transferring heat to the environment surrounding the propellant more quickly and controlling the temperature of the combustion zone. Using conventional aluminum powder can slow down the combustion rate and alleviate the pressure peak during the combustion process.

[0026] The room-temperature aluminum-water metal fuel propellant provided by this invention, by weight percentage, preferably comprises 8-12% aluminum trihydride, more preferably 9-11%. In this invention, the particle size of the aluminum trihydride is preferably 1-100 μm. In this invention, the aluminum trihydride can serve as a fuel additive, generating more combustion products and working fluid during combustion, thereby increasing the propellant thrust. Simultaneously, aluminum trihydride can increase the stability of aluminum powder combustion, reduce instability and severe oscillations during combustion, and improve the reliability of the propulsion system.

[0027] The room-temperature aluminum-ice metal fuel propellant provided by this invention preferably comprises 35-45% sodium sulfate hydrate, more preferably 38-43% by mass percentage. In this invention, the particle size of the sodium sulfate hydrate is preferably 1-100 μm. In this invention, the sodium sulfate hydrate preferably comprises one or more of sodium sulfate decahydrate, sodium sulfate heptahydrate, and sodium sulfate dodecahydrate. In this invention, the water of crystallization in the sodium sulfate hydrate can act as a reducing agent, solving the problem that aluminum ice propellants must be stored in a low-temperature environment and reducing the storage cost of the propellant. Simultaneously, sodium sulfate can decompose to generate a working fluid during propellant combustion, effectively improving the specific impulse of the propellant and enhancing its performance. Sodium sulfate hydrate has advantages such as simple preparation process, stable chemical properties, low cost, high water of crystallization content, and easy storage. It not only solves the temperature sensitivity problem faced by traditional aluminum ice propellants but also achieves safe storage at room temperature, while improving propulsion efficiency and performance, showing broad application prospects in the modern aerospace field.

[0028] The room-temperature molten aluminum metal fuel propellant provided by the present invention preferably comprises 8-10% perchlorate, more preferably 9-10% by mass percentage. In the present invention, the perchlorate preferably comprises potassium perchlorate or ammonium perchlorate;

[0029] This invention also provides a method for preparing the room-temperature molten aluminum metal fuel propellant described in the above technical solution, comprising the following steps:

[0030] The fuel, fuel additives, and oxidant are mixed and pressed in sequence to obtain the room-temperature aluminum molten metal fuel propellant.

[0031] In this invention, the mixing method preferably includes grinding; after grinding, the method further preferably includes screening the obtained material. This invention does not impose any particular limitation on the grinding and screening processes; any process well known to those skilled in the art can be used.

[0032] In this invention, the pressing is preferably performed using a pressing machine; the pressing pressure is preferably 200 MPa; by using mechanical pressure, the propellant can be pressed into the desired shape and density.

[0033] After pressing, the present invention preferably includes post-processing of the obtained pressed material, the post-processing preferably including drying, cutting and trimming, and surface treatment; drying can remove moisture or other solvent residues that may be contained in the solid propellant, further ensuring the stability of the propellant; cutting and trimming can make the solid propellant reach the required shape and size; surface treatment can improve the smoothness, durability and mechanical properties of the propellant.

[0034] Following the post-processing, the present invention preferably includes a comprehensive inspection of the room-temperature molten aluminum metal fuel propellant to ensure that it meets all design specifications and safety standards.

[0035] This invention uses a compression molding process, which is simple to manufacture and has good storage stability.

[0036] To further illustrate the present invention, the following detailed description of the room-temperature aluminum molten fuel propellant and its preparation method provided by the present invention is provided in conjunction with embodiments, but these descriptions should not be construed as limiting the scope of protection of the present invention.

[0037] Example 1

[0038] The mass ratio of each component is as follows: aluminum powder (Al): 41.7%, aluminum trihydride (AlH3): 8.2%, sodium sulfate decahydrate (Na2SO4·10H2O): 40.0%, ammonium perchlorate (AP): 10.1%.

[0039] The aforementioned metallic aluminum powder is a composite aluminum powder composed of ultrafine aluminum powder and conventional aluminum powder. The ultrafine aluminum powder has a particle size of 100 nm to 1 μm, and the conventional aluminum powder has a particle size of 1 to 100 μm. In the composite aluminum powder, ultrafine aluminum powder accounts for 60% of the total mass, and the remainder is conventional aluminum powder. The purity of the ultrafine aluminum powder is greater than 99%.

[0040] The aluminum trihydride has a particle size of 1~100μm.

[0041] The particle size of the sodium sulfate decahydrate is 1~100μm.

[0042] The fuel, fuel additives, and oxidizer required for solid propellant are formulated according to the above proportions, and then thoroughly ground and screened to ensure that all components are fully mixed.

[0043] The mixed solid propellant raw materials are placed into a press, and the propellant is pressed using mechanical pressure, with a pressing pressure of approximately 200 MPa.

[0044] The solid propellant, after being molded and pressed, undergoes post-processing to meet precise requirements for size and quality.

[0045] The propellant undergoes comprehensive testing to ensure it meets all design specifications and safety standards.

[0046] The performance of the propellant was tested. This invention uses thermodynamic software to calculate the combustion state of the fuel in the combustion chamber and uses the isentropic equation to calculate the gas parameters at the nozzle exit, ultimately obtaining the specific impulse of the propellant. This software, based on rigorous thermodynamic principles and equations, comprehensively considers important factors such as the propellant's chemical composition, combustion reaction equations, thermodynamic properties, and combustion products, enabling accurate performance evaluation of the propellant. The test conditions of this invention are a combustion chamber pressure of 68.6 MPa and a nozzle expansion ratio of 70. This invention inputs the propellant's test conditions and relevant parameters into the software to simulate the propellant's specific impulse performance. This software can calculate the performance parameters of propellants with different formulations and obtain the corresponding specific impulse values.

[0047] Table 1 shows the formulation components and properties of the Al / AlH3 / Na2SO4·10H2O / AP room temperature aluminum molten metal fuel propellant obtained in this embodiment.

[0048] Table 1 Formulation and performance of Al / AlH3 / Na2SO4·10H2O / AP ambient temperature aluminum molten metal fuel propellant

[0049]

[0050] As shown in Table 1, when the propellant is prepared according to the formula in Table 1, the density of the Al / AlH3 / Na2SO4·10H2O / AP room-temperature aluminum molten metal fuel propellant is 1.87 g / cm³. 3 Its specific impulse is 2042.4 m / s, and its combustion chamber temperature is 2811.3 K.

[0051] Example 2

[0052] Table 2 shows the formulation components and properties of the Al / AlH3 / Na2SO4·10H2O / AP room temperature aluminum molten metal fuel propellant obtained in this embodiment.

[0053] The preparation was carried out in accordance with the method described in Example 1.

[0054] Table 2 Formulation and Performance of Al / AlH3 / Na2SO4·10H2O / AP Room Temperature Aluminum Molten Metal Fuel Propellant

[0055]

[0056] As shown in Table 2, when the propellant is prepared according to the formula in Table 2, the density of the Al / AlH3 / Na2SO4·10H2O / AP room temperature aluminum molten metal fuel propellant is 1.84 g / cm³. 3 The specific impulse is 2070.5 m / s, and the combustion chamber temperature is 2806.8 K.

[0057] Example 3

[0058] Table 3 shows the formulation components and properties of the Al / AlH3 / Na2SO4·10H2O / AP room temperature aluminum molten metal fuel propellant obtained in this embodiment.

[0059] The preparation was carried out in accordance with the method described in Example 1.

[0060] Table 3 Formulation and performance of Al / AlH3 / Na2SO4·10H2O / AP room temperature aluminum molten metal fuel propellant

[0061]

[0062] As shown in Table 3, when the propellant is prepared according to the formula in Table 3, the density of the Al / AlH3 / Na2SO4·10H2O / AP room temperature aluminum molten metal fuel propellant is 1.83 g / cm³. 3 Its specific impulse is 2092.5 m / s, and its combustion chamber temperature is 2782.6 K.

[0063] Example 4

[0064] Table 4 shows the formulation components and properties of the Al / AlH3 / Na2SO4·12H2O / AP room temperature aluminum molten metal fuel propellant obtained in this embodiment.

[0065] The preparation was carried out in accordance with the method described in Example 1.

[0066] Table 4 Formulation and Performance of Al / AlH3 / Na2SO4·12H2O / AP Room Temperature Aluminum Molten Metal Fuel Propellant

[0067]

[0068] As shown in Table 4, when the propellant is prepared according to the formula in Table 4, the density of the Al / AlH3 / Na2SO4·12H2O / AP room temperature aluminum molten metal fuel propellant is 1.83 g / cm³. 3 Its specific impulse is 2118.5 m / s, and its combustion chamber temperature is 2782.2 K.

[0069] Example 5

[0070] Table 5 shows the formulation components and properties of the Al / AlH3 / Na2SO4·12H2O / AP room temperature aluminum molten metal fuel propellant obtained in this embodiment.

[0071] The preparation was carried out in accordance with the method described in Example 1.

[0072] Table 5 Formulation and Performance of Al / AlH3 / Na2SO4·12H2O / AP Room Temperature Aluminum Molten Metal Fuel Propellant

[0073]

[0074] As shown in Table 5, when the propellant is prepared according to the formula in Table 5, the density of the Al / AlH3 / Na2SO4·12H2O / AP room temperature aluminum molten metal fuel propellant is 1.85 g / cm³. 3 The specific impulse is 2102.0 m / s, and the combustion chamber temperature is 2822.9 K.

[0075] Example 6

[0076] Table 6 shows the formulation components and properties of the Al / AlH3 / Na2SO4·12H2O / AP room temperature aluminum molten metal fuel propellant obtained in this embodiment.

[0077] The preparation was carried out in accordance with the method described in Example 1.

[0078] Table 6 Formulation and Performance of Al / AlH3 / Na2SO4·12H2O / AP Room Temperature Aluminum Molten Metal Fuel Propellant

[0079]

[0080] As shown in Table 6, when the propellant is prepared according to the formula in Table 6, the density of the Al / AlH3 / Na2SO4·12H2O / AP room temperature aluminum molten metal fuel propellant is 1.85 g / cm³. 3 Its specific impulse is 2099.3 m / s, and its combustion chamber temperature is 2814.3 K.

[0081] Example 7

[0082] Table 7 shows the formulation components and properties of the Al / AlH3 / Na2SO4·7H2O / AP room-temperature aluminum molten metal fuel propellant obtained in this embodiment.

[0083] The preparation was carried out in accordance with the method described in Example 1.

[0084] Table 7 Formulation and Performance of Al / AlH3 / Na2SO4·7H2O / AP Room Temperature Aluminum Molten Metal Fuel Propellant

[0085]

[0086] As shown in Table 7, when the propellant is prepared according to the formula in Table 7, the density of the Al / AlH3 / Na2SO4·7H2O / AP room-temperature aluminum molten metal fuel propellant is 1.83 g / cm³. 3 The specific impulse is 2025.6 m / s, and the combustion chamber temperature is 2805.9 K.

[0087] Example 8

[0088] Table 8 shows the formulation components and properties of the Al / AlH3 / Na2SO4·7H2O / AP room-temperature aluminum molten metal fuel propellant obtained in this embodiment.

[0089] The preparation was carried out in accordance with the method described in Example 1.

[0090] Table 8 Formulation and Performance of Al / AlH3 / Na2SO4·7H2O / AP Room Temperature Aluminum Molten Metal Fuel Propellant

[0091]

[0092] As shown in Table 8, when the propellant is prepared according to the formula in Table 8, the density of the Al / AlH3 / Na2SO4·7H2O / AP room-temperature aluminum molten metal fuel propellant is 1.84 g / cm³. 3 The specific impulse is 2006.0 m / s, and the combustion chamber temperature is 2764.4 K.

[0093] Example 9

[0094] Table 9 shows the formulation components and properties of the Al / AlH3 / Na2SO4·7H2O / AP room-temperature aluminum molten metal fuel propellant obtained in this embodiment.

[0095] The preparation was carried out in accordance with the method described in Example 1.

[0096] Table 9 Formulation and Performance of Al / AlH3 / Na2SO4·7H2O / AP Room Temperature Aluminum Molten Metal Fuel Propellant

[0097]

[0098] As shown in Table 9, when the propellant is prepared according to the formula in Table 9, the density of the Al / AlH3 / Na2SO4·7H2O / AP room-temperature aluminum molten metal fuel propellant is 1.85 g / cm³. 3 The specific impulse is 1981.5 m / s, and the combustion chamber temperature is 2757.3 K.

[0099] As can be seen from the above embodiments, the present invention greatly reduces the cost of propellants and improves the specific impulse and storage performance of propellants.

[0100] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A room-temperature molten aluminum metal fuel propellant, comprising fuel, fuel additive, and oxidant, characterized in that, The fuel is aluminum powder, the fuel additive is aluminum trihydride, and the oxidant is sodium sulfate hydrate and perchlorate; The room-temperature aluminum molten metal fuel propellant comprises the following components in weight percentage: Aluminum powder: 35~45%; Aluminum trihydride: 8~12%; Sodium sulfate hydrate: 35~45%; Perchlorate: 8~10%; The aluminum powder includes ultrafine aluminum powder and conventional aluminum powder; the particle size of the ultrafine aluminum powder is 100nm~1μm; the particle size of the conventional aluminum powder is 1~100μm, excluding 1μm; the mass ratio of ultrafine aluminum powder in the aluminum powder is ≤60%.

2. The room-temperature molten aluminum metal fuel propellant according to claim 1, characterized in that, The aluminum trihydride has a particle size of 1~100μm.

3. The room-temperature molten aluminum metal fuel propellant according to claim 1, characterized in that, The particle size of the sodium sulfate hydrate is 1~100μm.

4. The room-temperature molten aluminum metal fuel propellant according to claim 1, characterized in that, The sodium sulfate hydrate includes one or more of sodium sulfate decahydrate, sodium sulfate heptahydrate, and sodium sulfate dodecahydrate.

5. The room-temperature molten aluminum metal fuel propellant according to claim 1, characterized in that, The perchlorate includes potassium perchlorate or ammonium perchlorate.

6. The method for preparing the room-temperature molten aluminum metal fuel propellant according to any one of claims 1 to 5, characterized in that, Includes the following steps: The fuel, fuel additives, and oxidant are mixed and pressed in sequence to obtain the room-temperature aluminum molten metal fuel propellant.

7. The preparation method according to claim 6, characterized in that, The mixing method includes grinding; after grinding, the material is screened; the pressing is performed using a press, and the pressing pressure is 200 MPa.

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