Hydroxylamine nitrate monopropellant and method for preparing the same

Abstract

The application provides a hydroxylamine nitrate-based monopropellant and a preparation method thereof, and comprises the following components with mass percentage: HAN: 50%-70%; alcohol: 14%-25%; functional additive: 14%-35%; and water: 1%-5%; wherein the functional additive comprises high-energy additive and cosolvent additive, the mass percentage of the high-energy additive is 13.5%-34.8%, and the mass percentage of the cosolvent additive is 0.2%-0.5%. The hydroxylamine nitrate-based monopropellant provided by the application has the characteristics of green, low toxicity, high specific impulse performance, low sensitivity, clean and non-polluted combustion products and the like.

Description

Technical Field

[0001] This invention belongs to the field of propellant technology, and specifically relates to a hydroxylamine nitrate-based green high-energy single-component propellant and its preparation method. Background Technology

[0002] With the development of aerospace and space exploration technologies, propulsion technology is moving towards greener and higher-energy directions. Conventional hydrazine-based propellant technology can no longer meet the demands of this development. Hydroxylamine nitrate (HAN), with the molecular formula H4N2O4, is produced by reducing NH3OH. + and oxidizing NO3 - Molecules formed by electrostatic forces. Acute oral median lethal dose (LD50) of hydrazine and HAN (solid). 50 The toxicity data are 59 and 325 mg / kg, respectively. HAN is much less toxic than hydrazine, and its toxicity can be significantly reduced after being formulated into a solution. HAN propellants generally have low sensitivity; therefore, HAN-based propellants are often used as environmentally friendly, low-sensitivity monopropellants. Through special formulation design, the physicochemical properties of HAN-based propellants can be adjusted as needed. In propellant formulations, HAN generally acts as an oxidizer; catalytic decomposition or electric ignition decomposition releases heat, initiating the decomposition and combustion of fuel components. Complete combustion of the propellant produces gases such as water and nitrogen, achieving stable catalytic decomposition combustion, enabling monopropellant engines to have adjustable thrust and re-start characteristics.

[0003] Traditional HAN (Hydrogen-Induced Harmonic Drive) single-component propellants typically have a theoretical specific impulse between 210 and 260 seconds. Domestically and internationally, the introduction of high-energy substances can further improve the specific impulse performance of HAN propellants. Among high-performance HAN propellants, SHP-163 boasts the highest theoretical specific impulse at 276 seconds. High-performance HAN-based propellants are usually high-salt systems. Currently, conventional high-energy additives are primarily methanol or hydrazine salts, which have limited energy performance and thus limited impact on improving the overall specific impulse of the propellant. Furthermore, high-energy additives themselves have low solubility, and direct addition to the propellant can easily cause sedimentation, making the system unstable. Summary of the Invention

[0004] This invention proposes a high-performance green hydroxylamine nitrate-based monocomponent propellant and its preparation method, which can be used to improve the specific impulse performance of existing HAN-based propellants.

[0005] The technical solution provided by this invention is as follows:

[0006] In a first aspect, a hydroxylamine nitrate-based monocomponent propellant comprises the following components in weight percentages:

[0007] HAN: 50%-70%;

[0008] Alcohols: 14%-25%;

[0009] Functional additives: 14%-35%;

[0010] Water: 1%-5%;

[0011] The functional additives include high-energy additives and solubilizing additives, with high-energy additives accounting for 13.5%-34.8% by mass and solubilizing additives accounting for 0.2%-0.5% by mass.

[0012] Secondly, a method for preparing a hydroxylamine nitrate-based monocomponent propellant includes:

[0013] Mix the weighed HAN, water and alcohol, add a solubilizing additive, and mix thoroughly to obtain mixed solution A;

[0014] High-energy additives were added to mixed solution A in batches, and the mixture was stirred under sealed temperature to obtain a clear mixed solution B. Then, the temperature of mixed solution B was lowered to room temperature to obtain a hydroxylamine nitrate monocomponent propellant.

[0015] The present invention provides a hydroxylamine nitrate-based monocomponent propellant and its preparation method, which has the following characteristics:

[0016] Beneficial effects:

[0017] (1) The present invention provides a hydroxylamine nitrate-based monocomponent propellant and its preparation method. The functional additives can form hydrogen bonds with other components in the propellant, thereby stabilizing the system and improving the storage life of the propellant.

[0018] (2) The present invention provides a hydroxylamine nitrate-based single-component propellant and its preparation method, a functional additive, which can effectively improve the solubility of each component, improve the catalytic decomposition and combustion characteristics of the propellant, and enhance the specific impulse performance without affecting the physicochemical properties, flow characteristics and atomization performance of the propellant. It can achieve a theoretical specific impulse of HAN propellant of more than 290s, or even more than 300s.

[0019] (3) The present invention provides a hydroxylamine nitrate monocomponent propellant and its preparation method. The formulation is simple, the main raw materials are widely available and easy to prepare; the preparation process is simple, the cost is low and it is easy to scale up industrial production. Attached Figure Description

[0020] Figure 1 The theoretical specific impulse curves for propellants with different contents of DNOAF and HAN are shown (methanol content is fixed at 15%, water content is fixed at 1%, BMIMBF4 content is fixed at 0.2%, engine chamber pressure Pc = 1.0 MPa, and area ratio Ae / At = 80).

[0021] Figure 2 The theoretical specific impulse curves for propellants with different contents of DNTF and HAN are shown (ethanol content is fixed at 15%, water content is fixed at 1%, BMIMPF6 content is fixed at 0.2%, engine chamber pressure Pc = 1.0 MPa, and area ratio Ae / At = 80). Detailed Implementation

[0022] The features and advantages of the present invention will become clearer and more apparent from the following detailed description.

[0023] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0024] The present invention provides a hydroxylamine nitrate-based monocomponent propellant, the components of which include: hydroxylamine nitrate (HAN), alcohols, functional additives, and water.

[0025] Based on 100% of the total mass of this hydroxylamine nitrate monocomponent propellant, the mass percentage content of each component is as follows:

[0026] HAN: 50%–70%;

[0027] Alcohols: 14%-25%;

[0028] Functional additives: 14%-35%;

[0029] Water: 1%-5%;

[0030] Functional additives include high-energy additives and solubilizing additives.

[0031] Furthermore, the alcohol is one or a mixture of two of methanol and ethanol, both of which are of analytical grade.

[0032] Furthermore, the high-energy additive includes, but is not limited to, one or more of triazoles and furazolidones such as 3,5-dinitro-1,2,4-triazole, 3,3'-dinitro-4,4'-azofuran (DNOAF), and 3,4-dinitrofuranylfuran (DNTF). It is of superior purity and does not contain metal ions such as Fe and Ni. Preferably, it is one or two of 3,3'-dinitro-4,4'-azofuran (DNOAF) and 3,4-dinitrofuranylfuran (DNTF); the mass percentage of the high-energy additive is 13.5%-34.8%.

[0033] Furthermore, the solubilizing additive is mainly an imidazole ionic liquid that is liquid at room temperature, including but not limited to one or more imidazole ionic liquids composed of alkyl-substituted imidazole ring cations and nitrate anions, halide anions, tetrafluoroborate anions, hexafluorophosphate anions, etc.; preferably one or more of 1-methyl-3-butylimidazolium tetrafluoroborate (BMIMBF4) or 1-methyl-3-butylimidazolium hexafluorophosphate (BMIMPF6). The mass percentage of the solubilizing additive is 0.2%-0.5%. If the mass percentage of the solubilizing additive is higher than 0.5%, it can easily reduce the combustion performance of the propellant, causing ignition difficulties; if the mass percentage of the solubilizing additive is lower than 0.2%, it can easily reduce the solubility of other components, causing high-energy additives to precipitate and making the system unstable.

[0034] Furthermore, the water content is 1%-5%, preferably 1%-3%; too high a water content can easily reduce the specific impulse performance of the propellant, while too low a water content can easily cause combustion instability.

[0035] This invention also provides a method for preparing a hydroxylamine nitrate-based monocomponent propellant, comprising:

[0036] (1) Mix the weighed HAN, water and alcohol, stir manually for at least 5 minutes, add the weighed solubilizing additive, and sonicate for at least 30 minutes to obtain a mixed solution.

[0037] (2) Add the high-energy additive in 3-5 batches to the propellant mixture obtained in step 1), and stir with a mixer at a closed constant temperature of 40-50℃ for at least 30 minutes to obtain a clear mixture. Then lower the temperature of the mixture to room temperature to obtain hydroxylamine nitrate monocomponent propellant.

[0038] The order of feedstock addition is as follows: first, mix HAN, water, and alcohol, stir, then add the solubilizing additive, sonicate, and finally add the high-energy additive in batches at 40℃-50℃ before cooling. This dissolution sequence effectively ensures the uniformity of the components in the propellant and achieves homogeneous stability of the system.

[0039] Examples

[0040] Example 1

[0041] A hydroxylamine nitrate-based monocomponent propellant and its preparation method are disclosed in Table 1.

[0042] Table 1 Formulation Components of Example 1

[0043] Formulation composition Content (%wt) HAN 68.8 Methanol 15 3,3'-dinitro-4,4'-oxyazofurazan DNOAF 15 Water 1 1 -methyl-3-butyl imidazole tetrafluoroborate BMIMBF4 0.2

[0044] Weigh the raw materials according to the formula in Table 1;

[0045] Mix the weighed HAN, water and methanol, stir manually for 5 minutes, add the weighed solubilizing additive 1-methyl-3-butylimidazolium tetrafluoroborate, and sonicate for 30 minutes to obtain a mixed solution; add the high-energy additive 3,3'-dinitro-4,4'-azofuran in 3 batches to the propellant mixed solution obtained in the above steps, and stir with a stirrer at a closed constant temperature of 50°C for 30 minutes to obtain a mixed clear solution. Then lower the temperature of the mixed solution to room temperature to obtain the propellant.

[0046] Based on theoretical calculations, the performance indicators of this hydroxylamine nitrate-based monocomponent propellant are as follows:

[0047] Theoretical specific impulse: 301s;

[0048] Theoretical combustion flame temperature: 2645K;

[0049] Theoretical decomposition products (mole fraction): water vapor 43.8%, carbon dioxide 29.7%, nitrogen 25.9%, others: 0.6%.

[0050] The theoretical specific impulse curves of the propellant with different contents of DNOAF and HAN were obtained by adjusting the DNOAF and HAN content (methanol content fixed at 15%, water content fixed at 1%, BMIMBF4 content fixed at 0.2%, engine chamber pressure Pc = 1.0 MPa, area ratio Ae / At = 80). Figure 1 .

[0051] Example 2

[0052] A hydroxylamine nitrate-based monocomponent propellant and its preparation method are disclosed in Table 2. The formulation and mass fraction of the propellant are shown in Table 2.

[0053] Table 2 Formulation Components Table of Example 2

[0054] Formulation composition Content (%wt) HAN 59.8 Ethanol 15 3,4-dinitrofurazyl furazan DNTF 24 Water 1 1 -methyl-3-butyl imidazole hexafluorophosphate BMIMPF6 0.2

[0055] Weigh the raw materials according to the formula in Table 2;

[0056] Mix the weighed HAN, water and ethanol, stir manually for 5 minutes, add the weighed solubilizing additive 1-methyl-3-butylimidazolium hexafluorophosphate, and sonicate for 30 minutes to obtain a mixed solution. Add the high-energy additive 3,4-dinitrofurazanyloxyfurazanol in 5 batches to the propellant mixed solution obtained in the above steps, and stir with a stirrer at a closed constant temperature of 45°C for 30 minutes to obtain a mixed clear solution. Then lower the temperature of the mixed solution to room temperature to obtain the propellant.

[0057] Based on theoretical calculations, the performance indicators of the green hydroxylamine nitrate monocomponent propellant are as follows:

[0058] Theoretical specific impulse: 292s;

[0059] Theoretical combustion flame temperature: 2604K;

[0060] Theoretical decomposition products (mole fraction): water vapor 31.4%, carbon dioxide 23.7%, nitrogen 21.6%, hydrogen 21.4%, others 1.9%.

[0061] The theoretical specific impulse curves of the propellant with different contents of DNTF and HAN were obtained by adjusting the DNTF and HAN content (ethanol content fixed at 15%, water content fixed at 1%, BMIMPF6 content fixed at 0.2%, engine chamber pressure Pc = 1.0 MPa, area ratio Ae / At = 80). Figure 2 .

[0062] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0063] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A hydroxylamine nitrate-based monocomponent propellant, characterized in that, The components include the following components by mass percentage: HAN: 50%-70%; Alcohols: 14%-25%; Functional additives: 14%-35%; Water: 1%-5%; The functional additives include high-energy additives and solubilizing additives, with high-energy additives accounting for 13.5%-34.8% by mass and solubilizing additives accounting for 0.2%-0.5% by mass. The high-energy additive is selected from one or more of 3,5-dinitro-1,2,4-triazole, 3,3'-dinitro-4,4'-oxyazofuran, or 3,4-dinitrofuranyloxyfuran. The solubilizing additive is an imidazole ionic liquid that is liquid at room temperature.

2. The hydroxylamine nitrate-based monocomponent propellant according to claim 1, characterized in that, The alcohols are one or both of methanol and ethanol.

3. The hydroxylamine nitrate-based monocomponent propellant according to claim 1, characterized in that, The solubilizing additives include one or more of the following: alkyl-substituted imidazole ring cations and nitrate anions, halogen anions, tetrafluoroborate anions, and hexafluorophosphate anions in an imidazole ionic liquid.

4. A method for preparing a hydroxylamine nitrate-based monocomponent propellant according to any one of claims 1 to 3, characterized in that, include: Mix the weighed HAN, water and alcohol, add a solubilizing additive, and mix thoroughly to obtain mixed solution A; High-energy additives were added to mixed solution A in batches, and the mixture was stirred under sealed temperature to obtain a clear mixed solution B. Then, the temperature of mixed solution B was lowered to room temperature to obtain a hydroxylamine nitrate monocomponent propellant.

5. The method for preparing the hydroxylamine nitrate-based monocomponent propellant according to claim 4, characterized in that, Add the high-energy additive to the mixed solution A in 3-5 batches.

6. The method for preparing the hydroxylamine nitrate-based monocomponent propellant according to claim 4, characterized in that, Stirring in a sealed, constant-temperature environment at 40℃-50℃.

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