A grain for end-face combustion solid-liquid gas generator

Abstract

The application provides a grain for end-face combustion of a solid-liquid fuel gas generator, which comprises a body; one end of the body is a conical surface structure, and a group of vanes for improving the combustion rate of the grain are arranged in the body; the body and the vanes are made of the same material; and the body is fully nested with combustion medium. The application has simple and reasonable structure, solves the problem that the burning surface shape is difficult to maintain during the end-face combustion of a paraffin-based grain, and meets the supply demand of large-flow rich fuel gas, and is suitable for promotion and application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas generator, in particular to a grain for end-face combustion solid-liquid gas generator. BACKGROUND

[0002] The solid-liquid gas generator adopts separated storage of solid-liquid two-phase propellants, which is generally in the form of combination of solid fuel and liquid oxidizer. Therefore, the solid-liquid gas generator combines many advantages of liquid gas generator and solid gas generator, such as relatively simple structure, excellent safety, repeatable start, adjustable flow, green and non-toxic, and low cost. Based on the above advantages, the solid-liquid gas generator can be widely used in commercial fields as a fuel-rich gas supply system. Among them, the solid-liquid gas generator in the form of end-face combustion is an important structure. This combustion organization form is concerned by researchers due to its constant combustion surface and relatively stable combustion working condition.

[0003] Similar to the solid-liquid rocket engine, the traditional end-face combustion solid-liquid gas generator generally uses polymers such as end-hydroxyl polybutadiene, polyethylene and polymethyl methacrylate as solid fuel. Affected by the low conventional solid combustion regression rate, the end-face combustion solid-liquid gas generator is subject to the core problem of being difficult to produce large flow fuel-rich gas. In order to provide abundant fuel-rich gas, the method of increasing the diameter of the grain combined with the swirling injection can be used to increase the combustion surface area and improve the regression rate. This causes the disadvantages of increasing the structure size and weight of the gas generator. At the same time, affected by the swirling field, the grain combustion surface usually changes in shape, thereby affecting the stability of the combustion working condition.

[0004] Therefore, as a high regression rate fuel, the paraffin fuel shows its unique advantages in the application of the solid-liquid gas generator. Its regression rate is several times that of the conventional fuel (such as end-hydroxyl polybutadiene), which makes it have the potential to realize large flow fuel-rich gas supply by using a small grain diameter, effectively solves the difficulty of increasing the gas flow of the end-face combustion solid-liquid gas generator, and improves the volume utilization rate. At the same time, the purchase and processing cost of paraffin is low, and the test and use cost of the gas generator can be greatly reduced. In addition, the combustion heat value of paraffin is basically the same as that of end-hydroxyl polybutadiene, and the liquid film after liquefaction has excellent thermal protection capability.

[0005] However, the mechanical properties of paraffin fuel are obviously worse than those of hydroxyl-terminated polybutadiene, which makes it at risk of softening and collapsing in long-time combustion process. Although the addition of adhesives and hardening agents in paraffin improves the mechanical properties, it loses most of the advantages of high regression rate. In end-face combustion process, paraffin fuel is also affected by the fluidity of the surface liquid film, which makes it more difficult to maintain the end-face structure. Especially when combined with the swirling injection mode, the surface structure often becomes uneven, which makes the actual working condition deviate greatly.

[0006] These problems hinder the further development of paraffin-based fuel, and if it is actually applied to end-face combustion solid-liquid gas generator, the above problems must be solved. However, the current research on the performance improvement of end-face combustion solid-liquid gas generator is still very scarce, and the traditional grain design cannot well solve the problems in end-face combustion, and it is also difficult to find a grain material or additive that can meet the needs of high regression rate and good mechanical properties.

[0007] In view of the above, it is necessary to make further innovations to the prior art. SUMMARY

[0008] In view of the technical problems in the above background art, the present application provides a grain for end-face combustion solid-liquid gas generator, which has a simple and reasonable structure design, solves the problem of difficult maintenance of the combustion surface shape of paraffin-based grain in end-face combustion process, and meets the demand for supply of large-flow rich combustion gas.

[0009] To solve the above technical problems, the present application provides a grain for end-face combustion solid-liquid gas generator, which comprises a body; one end of the body is a conical surface structure, and a group of vanes for improving the combustion rate of the grain are arranged inside; the body and the vanes are made of the same material; and the body is fully nested with combustion medium.

[0010] The grain for end-face combustion solid-liquid gas generator, wherein the conical angle of the conical surface structure at one end of the grain is greater than or equal to 45°.

[0011] The grain for end-face combustion solid-liquid gas generator, wherein the shape of the vane conforms to the Archimedes spiral equation.

[0012] The grain for end-face combustion solid-liquid gas generator, wherein the materials of the body and the vanes can both be ABS material; the ABS material is composed of 43% acrylonitrile, 50% butadiene and 7% styrene by mass percentage.

[0013] The grain for the end-face combustion solid-liquid gas generator, wherein: the material of the body and the blade can also be aluminum-magnesium alloy; the aluminum-magnesium alloy comprises AlSi 10 Mg and Al 90 Mg 10 .

[0014] The grain for the end-face combustion solid-liquid gas generator, wherein: the paraffin-based fuel is included in the combustion medium (3); the paraffin-based fuel is composed of 58% low-melting paraffin, 20% high-molecular paraffin, 10% adhesive, 10% hardener and 2% carbon powder in terms of mass percentage.

[0015] The grain for the end-face combustion solid-liquid gas generator, wherein: the mass fraction of the paraffin-based fuel is higher than 75%.

[0016] The grain for the end-face combustion solid-liquid gas generator, wherein: the combustion medium further includes aluminum powder and magnesium powder.

[0017] The grain for the end-face combustion solid-liquid gas generator, wherein: the length-to-diameter ratio of the grain is between 0.1 and 5.0.

[0018] The grain for the end-face combustion solid-liquid gas generator, wherein: the forming mode of the grain at least includes one of the following: pouring or additive manufacturing.

[0019] With the above technical solution, the present application has the following beneficial effects:

[0020] The grain structure for the end-face combustion solid-liquid gas generator of the present application is simple and reasonable in design, solves the problem that the burning surface shape of the paraffin-based grain of the end-face combustion solid-liquid gas generator is difficult to maintain, and greatly improves the burning rate of the paraffin-based fuel by setting the spiral blade conforming to the Archimedes spiral equation, so that the solid-liquid gas generator can provide a larger flow of rich combustion gas under a smaller combustion chamber volume, effectively improving the volume utilization rate; secondly, the body and the blade made of ABS or aluminum-magnesium alloy greatly improve the mechanical properties of the grain, and at the same time improve the safety of the solid-liquid gas generator, and are suitable for promotion and application. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the following specific embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0022] Figure 1Structure diagram of the propellant grain for the solid-liquid gas generator according to the present application;

[0023] Figure 2 Structure diagram of the propellant grain for the solid-liquid gas generator according to the present application;

[0024] Figure 3 Structure diagram of the propellant grain for the solid-liquid gas generator according to the present application;

[0025] Figure 4 Structure diagram of the propellant grain for the solid-liquid gas generator according to the present application;

[0026] Figure 5 Comparison diagram of the propellant grain for the solid-liquid gas generator according to the present application and the conventional propellant grain. DETAILED DESCRIPTION

[0027] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0028] The present application will be further explained below with reference to specific embodiments.

[0029] As shown in the drawings, the present embodiment provides a propellant grain for an end-face combustion solid-liquid gas generator, which comprises a body 1, a blade 2 and a combustion medium 3. Figures 1-4 The body 1 has a conical surface structure at one end with a conical angle greater than or equal to 45 degrees, which is used to increase the burning surface area and reduce the diameter of the propellant grain; a group of blades 2 for increasing the burning rate of the propellant grain are arranged in the body 1; the shape of the blade 2 is constructed according to the Archimedes spiral equation to form an initial profile and then the blade thickness is extrapolated to form the shape; and the combustion medium 3 is nested between the body 1 and the blade 2, the combustion medium 3 comprises a paraffin-based fuel, and the mass fraction of the paraffin-based fuel is higher than 75%; the combustion medium can also comprise aluminum powder and magnesium powder; the mass percentage of the replaceable part of low-melting-point paraffin and high-molecular paraffin is less than or equal to 25%, and the mass percentage of the aluminum powder and the magnesium powder is less than or equal to 25%, which is used to increase the combustion heat value of the combustion medium 3.

[0030] The materials of the body 1 and the blade 2 are consistent, both of which are ABS or aluminum-magnesium alloy; the aluminum-magnesium alloy comprises AlSi 10 Mg and Al 90 Mg 10 .

[0031]

[0032] ​The thickness of the blade 2 is 0.5-5mm, and the blade 2 rotates 4-10 turns along the radial direction of the grain, the rotating direction of the blade 2 matches the injection mode of the oxidizer injector of the solid-liquid gas generator, if the injector is clockwise injection, the rotating direction of the blade 2 is opposite to the rotating injection direction, and the grain retreat rate can be further improved.

[0033] In the embodiment, the thickness of the body 1 is 1.5mm, and the length is 104mm; the thickness of the blade 2 is 1.2mm, the profile of the blade 2 meets the Archimedes spiral equation r=θ / 50, r represents the radius coordinate in the polar coordinate, θ represents the radian coordinate in the polar coordinate, the outer diameter of the grain is 84mm, and the ratio of the grain length to the diameter is about 1.24. The body 1 and the blade 2 are made of ABS material with low burning speed and high mechanical property, and the ABS material is composed of 43% acrylonitrile, 50% butadiene and 7% styrene in mass percentage. The combustion medium 3 comprises a paraffin-based fuel, and the paraffin-based fuel is composed of 58% low-melting-point paraffin, 20% high-molecular paraffin, 10% adhesive, 10% hardener and 2% carbon powder in mass percentage, and the mass percentage of the paraffin-based fuel is between 75% and 95%. In addition, in order to improve the calorific value of the paraffin-based fuel, high-performance materials such as aluminum powder or magnesium powder can be added to the combustion medium 3.

[0034] The length to diameter ratio of the grain of the present application is between 0.1 and 5.0; and the forming mode of the grain of the present application at least includes one of the following: pouring or additive manufacturing technology.

[0035] Based on the solid-liquid gas generator ground test bench with an oxidizer flow of 10g / s, the rotating direction of the grain blade is set to the clockwise direction, and excellent experimental performance effect can be achieved. The experimental results are shown in Figure 5 , which greatly improves the retreat rate of the grain based on the paraffin-based fuel.

[0036] In an embodiment of the present application, the body 1 and the blade 2 are integrally formed by additive manufacturing technology, and then the body 1 and the blade 2 are used as a mold to pour the combustion medium 3, finally ensuring that the grain is integrally formed, and there is no gap between the body 2, the blade 3 and the combustion medium 3.

[0037] The present application couples the advantages of high retreat rate paraffin-based fuel and high mechanical property material such as ABS, not only solves the problem that the burning surface shape is difficult to maintain in the end face combustion process of the paraffin-based grain, but also meets the demand of supplying large flow rich fuel gas for the end face combustion solid-liquid gas generator. The spiral blade improves the burning rate of the paraffin-based fuel, effectively improves the volume utilization rate of the engine; secondly, the body 1 and the blade 2 made of ABS material greatly improve the mechanical property of the grain, strengthen the burning surface structure maintaining ability, and improve the safety of the solid-liquid rocket engine.

[0038] The present application has simple and reasonable structure, solves the problem of difficult maintenance of burning surface shape during the burning process of paraffin-based propellant end face, and meets the supply demand of large-flow rich combustion gas.

[0039] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A grain for a face-burning solid-liquid-gas generator, characterized in that: The propellant grain comprises a body (1); one end of the body (1) is provided with an outer conical surface structure, and a set of vanes (2) for improving the burning rate of the propellant grain are arranged inside; the body (1) and the vanes (2) are made of the same material; the body (1) is fully nested with a combustion medium (3) inside; the shape of the vanes (2) conforms to the Archimedes spiral equation.

2. The grain for the end-burning solid-liquid fuel gas generator of claim 1, wherein: The conical angle of the outer conical surface structure at one end of the propellant grain is greater than or equal to 45°.

3. The grain for the end-burning solid-liquid fuel gas generator of claim 1, wherein: The materials of the body (1) and the vanes (2) are both ABS materials; the ABS material is composed of 43% of acrylonitrile, 50% of butadiene and 7% of styrene by mass percentage.

4. The grain for a head-fired solid-liquid fuel gas generator of claim 1, wherein: The material of the body (1) and the blade (2) is aluminum magnesium alloy; the aluminum magnesium alloy includes AlSi 10 Mg and Al 90 Mg 10 .

5. The grain for a head-fired solid-liquid fuel gas generator of claim 1, wherein: The combustion medium (3) comprises a paraffin-based fuel; the paraffin-based fuel is composed of 58% of low-melting paraffin, 20% of high-molecular paraffin, 10% of adhesive, 10% of hardener and 2% of carbon powder by mass percentage.

6. The grain for the end-burning solid-liquid fuel gas generator of claim 5, wherein: The mass percentage of the paraffin-based fuel is higher than 75%.

7. The grain for a head-fired solid-liquid fuel gas generator of claim 1, wherein: The combustion medium (3) comprises aluminum powder and magnesium powder, and the mass percentage of the aluminum powder and the magnesium powder is less than or equal to 25%.

8. The grain for a head-fired solid-liquid fuel gas generator of claim 1, wherein: The length-to-diameter ratio of the propellant grain is between 0.1 and 5.

0.

9. The grain for a head-fired solid-liquid fuel gas generator of claim 1, wherein The forming mode of the propellant grain at least comprises one of the following: pouring or additive manufacturing.

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