Composite heat insulation layer of combustion chamber of solid rocket engine

Abstract

The utility model belongs to the field of solid rocket engine design, and provides a composite heat insulation layer of a solid rocket engine combustion chamber, which mainly comprises a combustion chamber base body, an outer surface layer, an aerogel layer, an inner interface layer and a washing-resistant layer, and the outer surface layer, the aerogel layer, the inner interface layer and the washing-resistant layer are sequentially adhered on the combustion chamber base body. The combustion chamber base body is a force bearing structure and a charging cavity of the solid rocket engine, and the aerogel layer is a main functional layer for isolating gas heat and is completely adhered to the combustion chamber base body through the external surface layer; the scouring-resistant layer is a functional layer resistant to scouring and ablation, has a partial heat insulation function and is tightly adhered to the aerogel layer through the inner interface layer. According to the utility model, the heat insulation and anti-scouring capabilities of the composite heat insulation layer of the combustion chamber are effectively improved, the weight is relatively smaller, the charging space of an engine is increased, and the mass ratio of the engine is improved.

Description

Technical Field

[0001] This utility model belongs to the field of solid rocket engine design, specifically relating to a composite insulation layer for the combustion chamber of a solid rocket engine. Background Technology

[0002] During solid rocket motor ignition, the combustion chamber must withstand high-temperature, high-pressure combustion gases. To prevent the combustion chamber shell from weakening due to heat and affecting engine operation, an insulation layer is typically attached to the inside of the shell for thermal protection. This inner insulation layer is a critical component for the reliable operation of a solid rocket motor, significantly hindering the transfer of heat from the combustion gases to the combustion chamber shell. Poor performance of the inner insulation layer can lead to thermal runaway and burn-through of the combustion chamber shell, severely jeopardizing the operational safety of the solid rocket motor.

[0003] Currently, commonly used materials for internal insulation layers include EPDM rubber, nitrile rubber, and carbon fiber / phenolic resin. Among these, EPDM rubber is the most commonly used, as it has good thermal insulation performance, with a thermal conductivity of approximately 0.23 W / (m·K) and a density of about 1.1 g / cm³. 3 However, it has weak erosion resistance, with an oxyacetylene ablation rate of 0.1 mm / s. Nitrile rubber has good thermal insulation properties, but it is brittle and has poor compatibility with dual-base propellants. Carbon fiber / phenolic materials have strong erosion resistance, but poor thermal insulation properties and low elasticity, making them prone to cracking due to exhaust gas erosion. Furthermore, for long-endurance engines, a thicker insulation layer is required to resist exhaust gas ablation, and its weight is also significant.

[0004] Since conventional insulation materials cannot simultaneously meet the requirements of excellent thermal insulation performance, erosion resistance, and light weight, this utility model patent proposes a composite insulation layer for the combustion chamber of a solid rocket engine. Summary of the Invention

[0005] The purpose of this invention is to provide a composite insulation layer for the combustion chamber of a solid rocket engine, so as to solve the problem that the existing technology cannot meet the requirements of solid rocket engines for good heat insulation performance, erosion resistance, and ablation resistance of the insulation layer in the combustion chamber.

[0006] The technical solution of this utility model:

[0007] A composite insulation layer for a solid rocket motor combustion chamber mainly consists of a combustion chamber substrate, an outer interface layer, an aerogel layer, an inner interface layer, and an erosion-resistant layer. The outer interface layer, aerogel layer, inner interface layer, and erosion-resistant layer are sequentially bonded to the combustion chamber substrate. The erosion-resistant layer is the topmost insulation layer and is in direct contact with the propellant loading cavity 6 of the solid rocket motor.

[0008] The combustion chamber substrate, made of metal or composite shell, serves as the load-bearing structure and propellant cavity of the solid rocket engine. The outer interface layer is the bonding layer between the combustion chamber substrate and the aerogel layer, completely adhering the aerogel layer to the combustion chamber substrate. The aerogel layer is fully bonded to the combustion chamber substrate using organic adhesive as the outer interface layer, and is the main functional layer for isolating the heat from the combustion gases. The inner interface layer is the bonding layer between the aerogel layer and the erosion-resistant layer, ensuring a tight bond between the two layers. The erosion-resistant layer, covering the aerogel layer and bonded to the two layers by the inner interface layer, is a functional layer resistant to erosion and ablation, and also provides some thermal insulation.

[0009] Furthermore, the combustion chamber substrate is made of 30 steel, 30Cr3 steel, or carbon fiber material.

[0010] Furthermore, the outer interface layer uses organic adhesive, and it will not debond due to internal or external loads, environmental changes, or other factors.

[0011] Furthermore, the aerogel layer is made of nanoporous material with a large number of uniform nanoporous structures inside, which can prevent convective heat transfer, block radiative heat transfer, greatly extend the heat conduction path and reduce the contact area, resulting in an extremely low macroscopic thermal conductivity.

[0012] Furthermore, the aerogel layer is made of silica aerogel, alumina aerogel, or zirconium dioxide aerogel.

[0013] Furthermore, the inner interface layer uses high-temperature putty or organic adhesive materials.

[0014] Furthermore, the erosion-resistant layer is made of carbon fiber / phenolic material or graphite cloth / phenolic material.

[0015] The beneficial effects of this utility model are:

[0016] (1) Aerogel materials have a thermal conductivity and density much lower than traditional insulation materials, which can effectively improve the insulation capacity of the insulation layer and reduce its mass. At the same time, aerogel has a low elastic modulus, greater elasticity, and good mechanical properties. It can be used to release the stress concentration caused by the scour layer due to the scour of the gas, reduce the risk of cracking of the scour layer, and improve the reliability of the engine.

[0017] (2) The erosion-resistant layer is made of erosion-resistant material, which has good ablation resistance and erosion resistance, and can partially block the heat transferred from the high-temperature gas to the aerogel layer, thus slowing down the decrease in the heat insulation performance of the aerogel layer due to excessive temperature.

[0018] The composite insulation layer of this application has better heat insulation and erosion resistance, while being lighter, allowing for a larger engine propellant loading space and thus improving the engine's mass ratio. Attached Figure Description

[0019] Figure 1 A schematic diagram of a composite insulation layer for a solid rocket combustion chamber.

[0020] Figure 2 A partial schematic diagram of a composite insulation layer in a solid rocket combustion chamber.

[0021] Wherein: 1—combustion chamber substrate; 2—outer interface layer; 3—aerogel layer; 4—inner interface layer; 5—erosion resistant layer; 6—charge cavity. Detailed Implementation

[0022] The specific embodiments of this utility model are described clearly and completely below with reference to the accompanying drawings:

[0023] like Figure 1 , Figure 2 As shown, a composite insulation layer for a solid rocket motor combustion chamber mainly consists of a combustion chamber substrate 1, an outer interface layer 2, an aerogel layer 3, an inner interface layer 4, and an erosion-resistant layer 5. The outer interface layer 2, aerogel layer 3, inner interface layer 4, and erosion-resistant layer 5 are sequentially bonded to the combustion chamber substrate 1. The erosion-resistant layer 5 is the topmost insulation layer and is in direct contact with the propellant loading cavity 6 of the solid rocket motor.

[0024] The mass of the combustion chamber substrate 1 should be as small as possible to reduce the negative mass of the solid rocket motor. High-strength or ultra-high-strength metal shells or composite shells, such as 30 steel, 30Cr3 steel or carbon fiber materials, can be used. The combustion chamber substrate 1 is the load-bearing structure and propellant cavity of the solid rocket motor. It serves as the load-bearing substrate for the inner insulation layer, which is then bonded to it.

[0025] The outer interface layer 2 is the bonding interface layer between the combustion chamber substrate 1 and the aerogel layer 3. The aerogel layer 3 is completely bonded to the combustion chamber substrate. The outer interface layer 2 can be made of organic adhesive and will not debond due to internal or external loads, environmental changes, or other factors.

[0026] The aerogel layer 3 is completely bonded to the combustion chamber substrate 1 via organic adhesive as the outer interface layer 2, and is the main functional layer for isolating the heat of the combustion gas. The aerogel layer 3 can be made of nanoporous material, with a large number of uniform nanoporous structures inside, which can prevent convective heat transfer, block radiative heat transfer, greatly extend the heat conduction path and reduce the contact area, resulting in an extremely low macroscopic thermal conductivity. The aerogel layer is made of silica aerogel, alumina aerogel or zirconium dioxide aerogel material.

[0027] The inner interface layer 4 is the bonding interface layer between the aerogel layer 3 and the erosion-resistant layer 5, which makes the aerogel layer 3 and the erosion-resistant layer 5 tightly bonded; the inner interface layer 4 can be made of high-temperature putty or organic adhesive material.

[0028] The erosion-resistant layer 5, formed by the inner interface layer 4 covering the aerogel layer 3, is a functional layer that resists erosion and ablation, and also provides some thermal insulation. The erosion-resistant layer 5 can be made of carbon fiber / phenolic resin or graphite cloth / phenolic resin. This allows the entire composite insulation layer to possess good erosion and ablation resistance. The erosion-resistant layer 5 is the topmost layer of the insulation layer and is in direct contact with the propellant loading cavity 6 of the solid rocket motor.

[0029] When the solid rocket motor ignites, the combustion of the propellant in the propellant cavity 6 generates a large amount of continuous high-temperature gas. This high-temperature gas directly erodes the erosion-resistant layer 5 of the composite insulation layer. The erosion-resistant layer 5 resists the erosion and provides a certain degree of heat insulation. Heat is then transferred to the aerogel layer 3 through the inner interface layer 4. The aerogel layer 3 has strong heat insulation capabilities, preventing the large amount of heat transferred from being transferred to the combustion chamber substrate 1. This prevents thermal runaway and burn-through of the combustion chamber substrate 1, ensuring the safe operation of the solid rocket motor.

[0030] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the scope of protection of this application is intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application. Obviously, those skilled in the art can make various alterations and variations to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of protection of this application and its equivalents, this application also intends to include these modifications and variations.

Claims

1. A composite insulation layer for a solid rocket motor combustion chamber, characterized in that, It includes a combustion chamber substrate (1), an outer interface layer (2), an aerogel layer (3), an inner interface layer (4), and an erosion-resistant layer (5), wherein the outer interface layer (2), the aerogel layer (3), the inner interface layer (4), and the erosion-resistant layer (5) are sequentially attached to the combustion chamber substrate (1); The combustion chamber substrate (1) is made of metal shell or composite shell and is the load-bearing structure and propellant cavity of the solid rocket engine; The outer interface layer (2) is the bonding interface layer between the combustion chamber substrate (1) and the aerogel layer (3), and the aerogel layer (3) is completely bonded to the combustion chamber substrate (1); The aerogel layer (3) is completely bonded to the combustion chamber substrate by organic glue as the outer interface layer, and is the main functional layer for isolating the heat of the gas. The inner interface layer (4) is the bonding interface layer between the aerogel layer (3) and the erosion-resistant layer (5), so that the aerogel layer (3) and the erosion-resistant layer (5) are tightly bonded together. The erosion-resistant layer (5) covers the aerogel layer and is bonded to the two materials through the inner interface layer. It is a functional layer that resists erosion and ablation and also undertakes part of the heat insulation function.

2. The composite insulation layer of the solid rocket motor combustion chamber according to claim 1, characterized in that: The combustion chamber substrate (1) is made of 30 steel, 30Cr3 steel or carbon fiber material.

3. The composite insulation layer of the solid rocket motor combustion chamber according to claim 1, characterized in that: The outer interface layer (2) uses organic adhesive and does not debond due to internal or external loads or environmental changes.

4. The composite insulation layer of the solid rocket motor combustion chamber according to claim 1, characterized in that: The aerogel layer (3) is a nanoporous material with a large number of uniform nanoporous structures inside, which can prevent convective heat transfer, block radiative heat transfer, extend the heat conduction path and reduce the contact area, resulting in extremely low macroscopic thermal conductivity.

5. The composite insulation layer of the solid rocket motor combustion chamber according to claim 1, characterized in that: The aerogel layer (3) can be made of silica aerogel, alumina aerogel or zirconium dioxide aerogel.

6. The composite insulation layer of the solid rocket motor combustion chamber according to claim 1, characterized in that: The inner interface layer (4) uses high-temperature putty or organic adhesive material.

7. The composite insulation layer of the solid rocket motor combustion chamber according to claim 1, characterized in that: The erosion resistant layer (5) is made of carbon fiber / phenolic material or graphite cloth / phenolic material.

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