Solid-liquid hybrid propellant and method for preparing the same

Abstract

The present application relates to solid-liquid mixed propellant technical field, specifically disclose a kind of solid-liquid mixed propellant and its preparation method, including solid propellant and liquid oxidant, solid propellant includes binder system by mass percentage: 15%~20%;Solid fuel: 60%~70%;Auxiliary metal fuel: 10%~20%;Combustion modifier: 1.5%~3%;Performance modifier: 0.2%~1%;Wherein, combustion modifier includes tetramethylammonium octahydrotriborate and auxiliary combustion modifier.The solid-liquid mixed propellant has the advantage that ignition delay period is small.

Description

Technical Field

[0001] This invention relates to the field of solid-liquid hybrid propellant technology, specifically to a solid-liquid hybrid propellant and its preparation method. Background Technology

[0002] Hybrid rocket engines represent an important development direction in rocket propulsion systems and are gradually becoming significant competitors to solid and liquid engines, with broad application prospects. A hybrid rocket engine is a propulsion system that falls between liquid and solid rocket engines. The liquid oxidizer system is similar to that of a liquid rocket engine, while the propellant grain, engine casing, and nozzle are similar to those of a solid rocket engine. Compared to liquid engines, hybrid engines have only half the number of pipes, pumps, and other moving parts, resulting in relatively higher reliability. Compared to solid engines, they allow for thrust adjustment, multiple start-ups, and shutdowns. Therefore, this propulsion system offers advantages such as high safety and reliability, excellent performance, and the ability to perform multiple shutdowns and restarts.

[0003] Solid-liquid hybrid propellants consist of solid fuel and liquid oxidizer, but the low burning rate and long ignition delay of solid fuel propellants currently limit their application. Current research attempts to improve burning rate include using novel binders such as polydicyclopentadiene (DCPD), adding metal hydrides, and adding small amounts of KClO4. Studies have also been conducted on hybrid propellants, developing solid fuel formulations and performing solid-liquid engine tests with diameters of 100mm, 120mm, 300mm, and 500mm, achieving average burning rates of 0.96–1.10 mm / s and ignition delays of 126 ms. However, no research reports have yet emerged on solid-liquid hybrid propellants that can shorten the ignition delay. Summary of the Invention

[0004] To address the aforementioned problems, the first objective of this invention is to provide a solid-liquid hybrid propellant that has the advantage of a short ignition delay period.

[0005] A second objective of this invention is to provide a method for preparing the aforementioned solid-liquid hybrid propellant.

[0006] The first technical solution adopted in this invention is: a solid-liquid hybrid propellant, comprising a solid propellant and a liquid oxidizer, wherein the solid propellant comprises the following components by mass percentage: Adhesive system: 15%–20%; Solid fuel: 60%–70%; Auxiliary metal fuel: 10%~20%; Combustion regulator: 1.5%–3%; Performance modifier: 0.2%~1%; The combustion regulator comprises tetramethylammonium octahydrotriborate and an auxiliary combustion regulator, wherein the mass ratio of tetramethylammonium octahydrotriborate and the auxiliary combustion regulator is 4:1.

[0007] Preferably, the liquid oxidant is fuming nitric acid, and the mass ratio of the liquid oxidant to the solid propellant is 3:1.

[0008] Preferably, the auxiliary combustion regulator is one or more of ferric oxide, catoxine, copper chromite, and n-octylferrocene.

[0009] Preferably, the adhesive system comprises an adhesive, a curing agent, and a plasticizer, wherein the mass ratio of the adhesive, curing agent, and plasticizer is 13.10–16.15:0.95–1.05:3; the adhesive is hydroxyl-terminated polybutadiene; the curing agent is one or more of toluene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate; and the plasticizer is one or more of diisooctyl sebacate and tributyl acetylacetonate.

[0010] Preferably, the solid fuel is octahydropyridine-(1,2-a)-pyridine.

[0011] Preferably, the octahydropyridine-(1,2-a)-pyridine is prepared by the following method: Octahydropyridine-(1,2-a)-pyridine can be prepared by reacting hydrazine and formaldehyde at 30℃~50℃.

[0012] Preferably, the auxiliary metal fuel is one or more of aluminum powder and magnesium powder.

[0013] Preferably, the performance modifier is one or more of tris(-2-methylaziridine-1)phosphine oxide, triphenylbismuth, iron acetylacetone, boron trifluoride triethanolamine, and methylene 4426-S.

[0014] The second technical solution adopted in this invention is: a method for preparing a solid-liquid hybrid propellant as described in the first technical solution, comprising the following steps: S1: In a dry environment, weigh each component according to the proportion, and add the combustion modifier, performance modifier, and plasticizer to the binder, and add auxiliary metal fuel for premixing to obtain a premixed slurry; S2: Add the premixed slurry to the mixer, and add solid fuel in batches for mixing. After the components are fully mixed, add the curing agent and continue mixing until uniform to obtain the slurry. S3: The slurry is poured into the engine through the wall to obtain a solid propellant, and the liquid oxidant is stored separately in the oxidant tank to obtain a solid-liquid mixed propellant.

[0015] The beneficial effects of the above technical solution are as follows: (1) Compared with similar solid-liquid hybrid propellants in China, the solid-liquid hybrid propellant disclosed in this invention has the advantage of a small ignition delay period.

[0016] (2) The present invention provides a solid-liquid hybrid propellant with a short ignition delay period for a solid-liquid hybrid engine, which adopts a novel high-efficiency combustion regulator to improve the burning rate of the solid-liquid hybrid propellant and significantly shorten the ignition delay time of the solid-liquid hybrid propellant.

[0017] (3) The solid-liquid hybrid propellant provided by the present invention introduces a novel high-efficiency combustion regulator to improve the combustion performance of the solid-liquid hybrid propellant and shorten the ignition delay time. The burning rate of the solid-liquid hybrid propellant is further increased by keeping the ratio of liquid oxidizer and solid propellant unchanged. The invention solves the problems of long ignition delay time and low burning rate of solid-liquid hybrid propellant, expands the application range of solid-liquid hybrid propellant, lays a solid foundation for the development of power device of solid-liquid hybrid rocket engine, and can also significantly enhance my country's national defense strength. Attached Figure Description

[0018] Figure 1 This is a process flow diagram of a method for preparing a solid-liquid hybrid propellant according to the present invention. Detailed Implementation

[0019] The present invention will be further illustrated below with specific embodiments. It should be noted that those skilled in the art can make several modifications and improvements without departing from the principle of the present invention, and these should also be considered to fall within the protection scope of the present invention.

[0020] The contents not described in detail in this specification are common knowledge to those skilled in the art.

[0021] This invention discloses a solid-liquid hybrid propellant, comprising a solid propellant and a liquid oxidizer, wherein the solid propellant comprises the following components by mass percentage: Adhesive system: 15%–20%; Solid fuel: 60%–70%; Auxiliary metal fuel: 10%~20%; Combustion regulator: 1.5%–3%; Performance modifier: 0.2%~1%; The mass ratio of the liquid oxidizer to the solid propellant is 3:1.

[0022] The novel high-efficiency combustion regulator is based on tetramethylammonium octahydrogen triborate, and the auxiliary combustion regulator is one or more of ferric oxide (Fe2O3), cattoxin (GFP), copper chromite (CC), and n-octylferrocene (T27); that is, the combustion regulator includes tetramethylammonium octahydrogen triborate and auxiliary combustion regulator, and the mass ratio of tetramethylammonium octahydrogen triborate and auxiliary combustion regulator is 4:1.

[0023] The adhesive system includes an adhesive, a curing agent, and a plasticizer, wherein the mass ratio of the adhesive, curing agent, and plasticizer in the adhesive system is 13.10–16.15:0.95–1.05:3; the adhesive is hydroxyl-terminated polybutadiene (HTPB); the curing agent is one or more of toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), and hexamethylene diisocyanate (HDI); and the plasticizer is one or more of diisooctyl sebacate (DOS) and tributyl acetylacetonate (ATBC).

[0024] The solid fuel is octahydropyridine-(1,2-a)-pyridine, which is prepared by the following method: Octahydropyridine-(1,2-a)-pyridine can be prepared by reacting hydrazine and formaldehyde at 30℃~50℃; the mass ratio of hydrazine to formaldehyde is 4:5.

[0025] The auxiliary metal fuel is one or more of aluminum powder and magnesium powder.

[0026] The performance modifier is one or more of tris(-2-methylaziridine-1)phosphine oxide (MAPO), triphenylbismuth (TPB), iron acetylacetone (FeAA), boron trifluoride triethanolamine (TEA), and methylene 4426-S (Hs).

[0027] The liquid oxidant is fuming nitric acid (FNA).

[0028] like Figure 1 As shown, a solid-liquid hybrid propellant is prepared through the following steps: S1: In a dry environment, weigh each component according to the proportion, and add the combustion modifier, performance modifier, and plasticizer to the binder, and add auxiliary metal fuel for premixing to obtain a premixed slurry; S2: Add the premixed slurry to the mixer, and add solid fuel octahydropyridine-(1,2-a)-pyridine in batches for mixing. After the components are fully mixed, add the curing agent and continue mixing until uniform to obtain the slurry. S3: The slurry is poured into the engine through a wall-mounted method (vacuum-cast into the engine and placed in a dry environment at about 60°C to cure for 7 days) to obtain a solid propellant; and the liquid oxidizer is stored separately in an oxidizer tank to obtain a solid-liquid mixed propellant; when the engine needs to work, the liquid oxidizer is sprayed onto the surface of the solid propellant, and the liquid oxidizer can be combusted upon contact with the solid propellant.

[0029] The prepared solid-liquid hybrid propellant was characterized as follows: 1) Density, determined according to standard QJ 917A-1997 "Method for Determination of Density of Composite Solid Propellants, Liners and Insulation Materials"; 2) Ignition delay time shall be measured in accordance with the standards GJB96A-2020 "Standard Test Engine Types and Dimensions" and GJB97A-2020 "Standard Test Engine Technical Requirements and Data Processing"; 3) Maximum tensile strength and maximum elongation shall be determined in accordance with the standard GJB770B-2022 "Test Methods for Gunpowder".

[0030] Example 1 Weigh each material according to the formula in Table 1 (calculated as a percentage by mass): Table 1. Composition and Formulation of Solid-Liquid Hybrid Propellants The weighed combustion modifier, performance modifier, and plasticizer are added to the binder, and auxiliary metal fuel is added for premixing to obtain a premixed slurry. The premixed slurry is added to a mixer, and solid fuel octahydropyridine-(1,2-a)-pyridine is added in batches for mixing. After the components are fully mixed, a curing agent is added and the mixture is further mixed until homogeneous to obtain a slurry. The slurry is vacuum-cast into the engine and placed in a dry environment at about 60°C for curing for 7 days to obtain a solid propellant. The liquid oxidizer is stored separately in an oxidizer tank. When the engine needs to be operated, the liquid oxidizer is sprayed onto the surface of the solid propellant, and combustion occurs upon contact with the solid propellant.

[0031] The properties of the prepared solid-liquid hybrid propellant were measured, and the results are shown in Table 2.

[0032] Table 2 Performance of Solid-Liquid Hybrid Propellants Example 2 Weigh each material according to the formula in Table 3 (calculated as a percentage by mass): Table 3. Composition and Formulation of Solid-Liquid Hybrid Propellants The weighed combustion modifier, performance modifier, and plasticizer are added to the binder, and auxiliary metal fuel is added for premixing to obtain a premixed slurry. The premixed slurry is added to a mixer, and solid fuel octahydropyridine-(1,2-a)-pyridine is added in batches for mixing. After the components are fully mixed, a curing agent is added and the mixture is further mixed until homogeneous to obtain a slurry. The slurry is vacuum-cast into the engine and placed in a dry environment at about 60°C for curing for 7 days to obtain a solid propellant. The liquid oxidizer is stored separately in an oxidizer tank. When the engine needs to be operated, the liquid oxidizer is sprayed onto the surface of the solid propellant, and combustion occurs upon contact with the solid propellant.

[0033] The properties of the prepared solid-liquid hybrid propellant were measured, and the results are shown in Table 4.

[0034] Table 4 Performance of Solid-Liquid Hybrid Propellants Example 3 Weigh each material according to the formula in Table 5 (calculated as a percentage by mass): Table 5. Composition and Formulation of Solid-Liquid Hybrid Propellants The weighed combustion modifier, performance modifier, and plasticizer are added to the binder, and auxiliary metal fuel is added for premixing to obtain a premixed slurry. The premixed slurry is added to a mixer, and solid fuel octahydropyridine-(1,2-a)-pyridine is added in batches for mixing. After the components are fully mixed, a curing agent is added and the mixture is further mixed until homogeneous to obtain a slurry. The slurry is vacuum-cast into the engine and placed in a dry environment at about 60°C for curing for 7 days to obtain a solid propellant. The liquid oxidizer is stored separately in an oxidizer tank. When the engine needs to be operated, the liquid oxidizer is sprayed onto the surface of the solid propellant, and combustion occurs upon contact with the solid propellant.

[0035] The properties of the prepared solid-liquid hybrid propellant were measured, and the results are shown in Table 6.

[0036] Table 6 Performance of Solid-Liquid Hybrid Propellants Example 4 Weigh each material according to the formula in Table 7 (calculated as a percentage by mass): Table 7. Composition and Formulation of Solid-Liquid Hybrid Propellants The weighed combustion modifier, performance modifier, and plasticizer are added to the binder, and auxiliary metal fuel is added for premixing to obtain a premixed slurry. The premixed slurry is added to a mixer, and solid fuel octahydropyridine-(1,2-a)-pyridine is added in batches for mixing. After the components are fully mixed, a curing agent is added and the mixture is further mixed until homogeneous to obtain a slurry. The slurry is vacuum-cast into the engine and placed in a dry environment at about 60°C for curing for 7 days to obtain a solid propellant. The liquid oxidizer is stored separately in an oxidizer tank. When the engine needs to be operated, the liquid oxidizer is sprayed onto the surface of the solid propellant, and combustion occurs upon contact with the solid propellant.

[0037] The properties of the prepared solid-liquid hybrid propellant were measured, and the results are shown in Table 8.

[0038] Table 8 Performance of Solid-Liquid Hybrid Propellants Example 5 Weigh each material according to the formula in Table 9 (calculated as a percentage by mass): Table 9. Composition and Formulation of Solid-Liquid Hybrid Propellants The weighed combustion modifier, performance modifier, and plasticizer are added to the binder, and auxiliary metal fuel is added for premixing to obtain a premixed slurry. The premixed slurry is added to a mixer, and solid fuel octahydropyridine-(1,2-a)-pyridine is added in batches for mixing. After the components are fully mixed, a curing agent is added and the mixture is further mixed until homogeneous to obtain a slurry. The slurry is vacuum-cast into the engine and placed in a dry environment at about 60°C for curing for 7 days to obtain a solid propellant. The liquid oxidizer is stored separately in an oxidizer tank. When the engine needs to be operated, the liquid oxidizer is sprayed onto the surface of the solid propellant, and combustion occurs upon contact with the solid propellant.

[0039] The properties of the prepared solid-liquid hybrid propellant were measured, and the results are shown in Table 10.

[0040] Table 10 Performance of Solid-Liquid Hybrid Propellants Example 6 Weigh each material according to the formula in Table 11 (calculated as a percentage by mass): Table 11 Composition and Formulation of Solid-Liquid Hybrid Propellants The weighed combustion modifier, performance modifier, and plasticizer are added to the binder, and auxiliary metal fuel is added for premixing to obtain a premixed slurry. The premixed slurry is added to a mixer, and solid fuel octahydropyridine-(1,2-a)-pyridine is added in batches for mixing. After the components are fully mixed, a curing agent is added and the mixture is further mixed until homogeneous to obtain a slurry. The slurry is vacuum-cast into the engine and placed in a dry environment at about 60°C for curing for 7 days to obtain a solid propellant. The liquid oxidizer is stored separately in an oxidizer tank. When the engine needs to be operated, the liquid oxidizer is sprayed onto the surface of the solid propellant, and combustion occurs upon contact with the solid propellant.

[0041] The properties of the prepared solid-liquid hybrid propellant were measured, and the results are shown in Table 12.

[0042] Table 12 Performance of Solid-Liquid Hybrid Propellants Example 7 Weigh each material according to the formula in Table 13 (calculated as a percentage by mass): Table 13 Composition and Formulation of Solid-Liquid Hybrid Propellants The weighed combustion modifier, performance modifier, and plasticizer are added to the binder, and auxiliary metal fuel is added for premixing to obtain a premixed slurry. The premixed slurry is added to a mixer, and solid fuel octahydropyridine-(1,2-a)-pyridine is added in batches for mixing. After the components are fully mixed, a curing agent is added and the mixture is further mixed until homogeneous to obtain a slurry. The slurry is vacuum-cast into the engine and placed in a dry environment at about 60°C for curing for 7 days to obtain a solid propellant. The liquid oxidizer is stored separately in an oxidizer tank. When the engine needs to be operated, the liquid oxidizer is sprayed onto the surface of the solid propellant, and combustion occurs upon contact with the solid propellant.

[0043] The properties of the prepared solid-liquid hybrid propellant were measured, and the results are shown in Table 14.

[0044] Table 14 Performance of Solid-Liquid Hybrid Propellants Comparative Example 1 The table below shows the formulation composition and performance of the closest solid-liquid hybrid propellant for comparison.

[0045] (1) Composition of solid-liquid hybrid propellant (2) Performance of solid-liquid hybrid propellants The data from Example 1 and Comparative Example 1 show that the density, maximum tensile strength, and maximum elongation of the solid-liquid hybrid propellants prepared in Comparative Example 1 and Example 1 are comparable. However, the ignition delay period of the solid-liquid hybrid propellant disclosed in this invention is significantly shortened: the ignition delay period of Comparative Example 1 is 686 ms, while the ignition delay period of the solid-liquid hybrid propellant of this invention is no more than 50 ms.

[0046] The present invention has been described in detail above with reference to specific embodiments and exemplary examples. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments; the above 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 implementation methods of the present invention without departing from the spirit and scope of the present invention, and all such modifications and improvements fall within the scope of the present invention; the scope of protection of the present invention is determined by the appended claims.

Claims

1. A solid-liquid hybrid propellant, comprising a solid propellant and a liquid oxidizer, characterized in that, The solid propellant comprises the following components by mass percentage: Adhesive system: 15%–20%; Solid fuel: 60%–70%; Auxiliary metal fuel: 10%~20%; Combustion regulator: 1.5%–3%; Performance modifier: 0.2%~1%; The combustion regulator comprises tetramethylammonium octahydrotriborate and an auxiliary combustion regulator, wherein the mass ratio of tetramethylammonium octahydrotriborate and the auxiliary combustion regulator is 4:

1.

2. The solid-liquid hybrid propellant according to claim 1, characterized in that, The liquid oxidant is fuming nitric acid, and the mass ratio of the liquid oxidant to the solid propellant is 3:

1.

3. The solid-liquid hybrid propellant according to claim 1, characterized in that, The auxiliary combustion regulator is one or more of ferric oxide, catoxine, copper chromite, and n-octylferrocene.

4. The solid-liquid hybrid propellant according to claim 1, characterized in that, The adhesive system includes an adhesive, a curing agent, and a plasticizer, wherein the mass ratio of the adhesive, curing agent, and plasticizer is 13.10–16.15:0.95–1.05:3; the adhesive is hydroxyl-terminated polybutadiene; the curing agent is one or more of toluene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate; and the plasticizer is one or more of diisooctyl sebacate and tributyl acetylacetonate.

5. The solid-liquid hybrid propellant according to claim 1, characterized in that, The solid fuel is octahydropyridine-(1,2-a)-pyridine.

6. The solid-liquid hybrid propellant according to claim 5, characterized in that, The octahydropyridine-(1,2-a)-pyridine was prepared by the following method: Octahydropyridine-(1,2-a)-pyridine can be prepared by reacting hydrazine and formaldehyde at 30℃~50℃.

7. The solid-liquid hybrid propellant according to claim 1, characterized in that, The auxiliary metal fuel is one or more of aluminum powder and magnesium powder.

8. The solid-liquid hybrid propellant according to claim 1, characterized in that, The performance modifier is one or more of tris(-2-methylaziridine-1)phosphine oxide, triphenylbismuth, iron acetylacetone, boron trifluoride triethanolamine, and methylene 4426-S.

9. A method for preparing a solid-liquid hybrid propellant as described in any one of claims 1-8, characterized in that, Includes the following steps: S1: In a dry environment, weigh each component according to the proportion, and add the combustion modifier, performance modifier, and plasticizer to the binder, and add auxiliary metal fuel for premixing to obtain a premixed slurry; S2: Add the premixed slurry to the mixer, and add solid fuel in batches for mixing. After the components are fully mixed, add the curing agent and continue mixing until uniform to obtain the slurry. S3: The slurry is poured into the engine through the wall to obtain a solid propellant, and the liquid oxidant is stored separately in the oxidant tank to obtain a solid-liquid mixed propellant.

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