CN119953592A - Composite thermal control structure and use method thereof, space cryogenic storage tank - Google Patents

Abstract

The present invention provides a composite thermal control structure and a method for using the same, and a space low-temperature storage tank. The composite thermal control structure includes a thermal resistance layer, a thermal radiation layer, and an isolation layer. The thermal resistance layer is coated on the outside of the thermal control object, and the thermal resistance layer includes a support frame and a volatile material. The volatile material is filled in the gap of the support frame, and is used to provide thermal resistance in a ground environment and is volatile in a vacuum environment. The isolation layer is coated on the outside of the thermal resistance layer, and is used to isolate the thermal resistance layer from the external atmosphere in a ground environment. The thermal radiation layer is coated on the outside of the isolation layer, and is used to block external thermal radiation heat flow in a vacuum environment. In the present invention, after the volatile material is vaporized and volatilized during the change of the external vacuum degree, the radiation layer has almost no contact with the thermal control object under vacuum, and can provide thermal conductivity resistance in the ground state, reduce contact thermal resistance in a vacuum environment, and provide cold during the vaporization process, further increasing the applicability of the thermal control object in both the ground normal pressure environment and the vacuum environment.

Description

Composite thermal control structure, application method thereof and low-volume Wen Zhuxiang

Technical Field

The invention relates to the technical field of low-temperature storage tanks, in particular to a composite thermal control structure, a using method thereof and a space low-temperature storage tank.

Background

The low-temperature propellant liquid hydrogen, liquid oxygen, methane and the like belong to low-temperature fluid, the boiling point of the low-temperature fluid is low, and is usually lower than 120K, the low-temperature propellant liquid hydrogen, the liquid oxygen, the methane and the like have a larger temperature difference from a normal-temperature environment, and the propellant temperature can be vaporized after absorbing the environmental heat when rising to a saturated state. Therefore, the low-temperature rocket and the spacecraft need to be coated with the thermal control material in the ground test and space flight processes, so that the heat leakage of the ground and universe environment is reduced.

The common thermal control cladding structure of the current low Wen Zhuxiang and pipeline system is a super heat insulation structure with polyurethane foam outside the storage tank and multilayer aluminum foil (MLI) outside the polyurethane foam. Polyurethane foam mainly improves the thermal resistance in the thermal environment of the ground, because MLI has poor heat insulation effect in the atmosphere environment, and the heat leakage quantity caused by the convection and heat conduction of gas is large. If the thermal resistance is not raised by coating the foam, direct contact of the inner MLI layer with the low temperature outer wall of the tank can cause water vapor condensation inside the MLI, affecting the performance of the MLI. In the space environment, the outside of the aircraft is a vacuum environment, no convection and heat conduction of gas exist, and the MLI plays a main role in heat control at the moment and is used for isolating heat brought by solar and earth radiation, and heat leakage of heat conduction is avoided as much as possible. When a cryogenic propellant is in space, the amount of heat input is decisive for the effective amount of propellant used, and therefore it is most critical to reduce the heat input.

The problem in the current thermal control structure is that (1) polyurethane foam, which plays a major role in thermal resistance on the ground, reaches the space and instead causes the heat conduction between the multilayer MLI and the storage tank and pipeline to increase. In a vacuum environment, the heat radiation layer can well isolate external heat flow due to no gas convection. (2) When the MLI heat insulating material is coated on the surface of polyurethane foam, a plurality of layers are coated because radiation heat leakage is reduced as much as possible, which can lead to slow gas escape on the inner side of the MLI and reduce the performance of multi-layer heat insulation.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a composite thermal control structure, a using method thereof and a space low-temperature storage box.

The composite heat control structure comprises a heat resistance layer, a heat radiation layer and an isolation layer which are arranged in a laminated mode;

The thermal resistance layer is coated outside the thermal control object and comprises a supporting framework and a volatilizable material, wherein the volatilizable material is filled in a gap of the supporting framework and is used for providing thermal resistance in a ground environment and has volatility in a vacuum environment;

the thermal insulation layer is coated outside the thermal insulation layer and used for insulating the thermal insulation layer from the external atmosphere in a ground environment, and the heat radiation layer is coated outside the thermal insulation layer and used for blocking external heat radiation heat flow in a vacuum environment.

Preferably, when the thermal control object is located in a vacuum environment, the volatilizable material in the thermal resistance layer volatilizes, and the heat radiation layer is supported on the outer surface of the thermal control object through the supporting framework.

Preferably, the heat radiation layer comprises a plurality of aluminized film reflecting layers which are arranged in a laminated manner, and the temperature of each aluminized film reflecting layer is different.

Preferably, a woven spacer layer is arranged between the aluminized film reflective layers of the multilayer laminated arrangement, the woven spacer layer being used to reduce the contact area between the aluminized film reflective layers.

Preferably, through holes are drilled on the aluminized film reflecting layers, and the through holes on each aluminized film reflecting layer are staggered.

Preferably, the volatizable material comprises a solid volatizable material or a semi-solid volatizable material.

Preferably, the isolation layer comprises a plastic film, and the support skeleton comprises an integrally formed carbon fiber skeleton

According to the application method of the composite thermal control structure provided by the invention, the composite thermal control structure is adopted, and the application method comprises the following steps:

The ground environment using step is that the composite thermal control structure is in a normal pressure atmosphere environment, the thermal resistance layer is sealed by the isolating layer, and the thermal resistance layer is isolated from the atmosphere;

the vacuum environment using step is that the composite thermal control structure is in the vacuum environment, the isolation layer is broken, the volatilizable material of the thermal resistance layer volatilizes, and the thermal radiation layer is supported on the outer surface of the thermal control object through the supporting framework.

Preferably, in the vacuum environment using step, the method for breaking the isolation layer includes any one of the following steps:

actively removing the isolation layer;

actively manufacturing an opening on the isolation layer;

The original gas inside the isolation layer damages the isolation layer in the process of reducing the external air pressure.

The space low-temperature storage tank provided by the invention comprises a spherical storage tank body, wherein the outer surface of the spherical storage tank body is coated with the composite heat control structure.

Compared with the prior art, the invention has the following beneficial effects:

1. the thermal resistance layer is a variable phase substance, the heat transfer thermal resistance between the radiation layer and the surface of the low-temperature container can be increased under the normal pressure of the ground, the volatilization of the thermal resistance layer is realized under the vacuum environment of the space, and the contact between the radiation layer and the surface of the low-temperature container is reduced.

2. After the thermal resistance layer volatilizes in the space, the part, close to the wall surface of the container, of the inner side of the heat radiation layer is in a vacuum environment, so that release of inner-layer gas is facilitated.

Drawings

Other features, objects and advantages of the present invention will become more apparent upon reading of the detailed description of non-limiting embodiments, given with reference to the accompanying drawings in which:

FIG. 1 is a schematic cross-sectional view of the present invention;

fig. 2 is a schematic view of a partial cross-sectional structure of the present invention.

The figure shows:

Thermal barrier layer 1 isolation layer 3

Radiation layer 2 tank 4

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the present invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications could be made by those skilled in the art without departing from the inventive concept. These are all within the scope of the present invention.

The invention discloses a composite thermal control structure, a using method thereof and a space low-temperature storage box, wherein a thermal resistance layer comprises a volatilizable material and a supporting framework, the heat transfer thermal resistance between a radiation layer and the surface of a low-temperature container can be increased under the normal pressure of the ground, the volatilizable material volatilizes under the vacuum environment of the space, the contact between the radiation layer and the surface of the low-temperature container is reduced, and a thermal control object has good applicability in the normal pressure environment and the vacuum environment of the ground.

According to the composite thermal control structure provided by the invention, as shown in figures 1 and 2, the composite thermal control structure comprises a thermal resistance layer 1, a heat radiation layer 2 and an isolation layer 3 which are arranged in a laminated manner;

When the thermal control object is in a vacuum environment, the volatilizable material in the thermal resistance layer 1 volatilizes, the heat radiation layer 2 is supported on the outer surface of the thermal control object through the supporting framework, the supporting framework can keep the heat radiation layer 2 from contacting or avoid heat conduction between the heat radiation layer 2 and the wall surface of the storage tank in a form of less point contact, and the volatilizable material can pass through a saturated state to reach a gaseous state when the pressure is reduced, and volatilize, and can be a pure working medium or a compound, a hydrate, a gel or the like.

The isolation layer 3 is coated outside the thermal resistance layer 1 and is used for isolating the thermal resistance layer 1 from the atmosphere in the ground normal pressure environment of 0.1MPa, so that moisture is prevented from entering or unnecessary volatilization is avoided. The isolation layer 3 can be mechanically removed or opened in a vacuum environment, or the original part of gas in the interior damages the isolation layer 3 in the process of reducing the external air pressure, so that the thermal resistance layer 1 is volatilized when contacting with vacuum;

The heat radiation layer 2 is coated outside the isolation layer 3 and used for blocking external heat radiation heat flow in a vacuum environment, the heat radiation layer 2 comprises a plurality of aluminized film reflecting layers which are arranged in a laminated mode, the temperature of each aluminized film reflecting layer is different, through holes are formed in the aluminized film reflecting layers, and the through holes in each aluminized film reflecting layer are staggered, so that internal gas can be released conveniently, and high vacuum is achieved. And a braiding spacing layer is arranged between the aluminized film reflecting layers in multi-layer lamination arrangement and is used for reducing the contact area between the aluminized film reflecting layers, so that the heat conduction resistance is reduced.

The composite heat control structure can be used for a space low-temperature propellant storage tank, can realize that the heat radiation layer 2 does not contact the wall surface of the storage tank in the ground and space stages, provides heat resistance in the ground stage, improves the temperature of the innermost layer of the heat radiation layer 2, avoids icing inside the heat radiation layer 2, simultaneously ensures that the heat radiation layer 2 is prevented from contacting the wall surface of the storage tank in the space stage, and reduces heat conduction.

According to the application method of the composite thermal control structure provided by the invention, the composite thermal control structure is adopted, and the application method comprises the following steps:

The ground environment using step is that the composite thermal control structure is in a normal pressure atmosphere environment, the thermal resistance layer 1 is sealed by the isolation layer 3, the thermal resistance layer 1 is isolated from the atmosphere, and the thermal resistance layer 1 keeps the structural stability under the cladding of the isolation layer 3, thereby playing a role in heat conduction and resistance;

the vacuum environment using step is that the composite heat control structure is in the vacuum environment, the isolation layer 3 is broken, the volatilizable material of the thermal resistance layer 1 volatilizes, the volatilizable layer volatilizes gradually, the heat radiation layer 2 is supported on the outer surface of a heat control object through the supporting framework, the contact heat conduction between the radiation layer and the wall surface of the container is reduced, and the heat flow is reduced. The breaking method of the isolation layer 3 comprises any one of actively removing the isolation layer 3, actively manufacturing an opening on the isolation layer 3, and breaking the isolation layer 3 by original gas inside the isolation layer 3 in the process of reducing the external gas pressure.

The space low-temperature storage tank provided by the invention comprises a spherical storage tank body, wherein the outer surface of the spherical storage tank body is coated with the composite heat control structure as claimed in any one of claims 1 to 7.

Example 1

In this embodiment, the thermal control object is a spherical container, a working medium accommodating space is arranged inside the spherical container, the working medium is liquid oxygen, the volatilizable material is solid carbon dioxide (which is in a gaseous state and a solid state below 0.1MPa, when the temperature is lower than-56.6 ℃ and is solid, the temperature of a low Wen Zhuxiang metal wall surface is 100K and is far lower than-56.6 ℃, according to the gas-solid saturation line of the carbon dioxide, the gas state is reached through the saturation state when the pressure is reduced and the volatilizing occurs), and the composite thermal control structure is coated on the outer side of the spherical container. The thermal resistance layer 1 comprises a carbon fiber 3d printing framework and a volatilizable material which are integrally formed, the formed framework is arranged in the volatilizing layer, and after the volatilizing layer volatilizes, the framework can support the heat radiation layer 2 to avoid collapsing so as to cause the condition of contacting the wall surface of the container in a large area. The tank may be equipped with a refrigerator that provides the thermal barrier with the necessary amount of cooling to maintain its solid state characteristics in addition to the cooling provided by the cryogenic tank. The barrier layer 3 is made of an ultra-thin plastic film, and discharges the internal air at the time of coating. The heat radiation layer 2 is coated on the isolation layer 3 and is formed by compounding an aluminum foil and a fiber layer, and the aluminum foil and the fiber layer are both perforated with small holes so as to facilitate the release of internal gas and achieve high vacuum. The radiation layer of the liquid oxygen storage tank is designed into a variable density structure, the lower the temperature is, the lower the density is, namely the number of aluminum foils in the unit distance of the inner layer is small, the number of aluminum foils in the unit distance of the position close to the outer layer is large, and the aluminum foils are separated by fiber layers to avoid direct contact heat conduction.

In the ground environment, after filling liquid oxygen into the spherical container, the thermal resistance layer 1 plays a role in thermal resistance, nitrogen is introduced into the external environment of the container, the content of water vapor is reduced, and no water vapor is frozen. When the heat radiation layer is in a space outside the atmosphere, the isolation layer 3 is destroyed, the heat resistance layer 1 gradually becomes gas to volatilize, the gas in the heat radiation layer 2 is released to the outside and the inside through the perforated multi-layer aluminum foil, the interlayer gradually reaches a high vacuum state, and the effect of radiation heat resistance is better exerted.

In the description of the present application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

The foregoing describes specific embodiments of the present application. It is to be understood that the application is not limited to the particular embodiments described above, and that various changes or modifications may be made by those skilled in the art within the scope of the appended claims without affecting the spirit of the application. The embodiments of the application and the features of the embodiments may be combined with each other arbitrarily without conflict.

Claims (10)

1. A composite thermal control structure, characterized in that it comprises a thermal resistance layer (1), a heat radiation layer (2) and an isolation layer (3) which are stacked; The thermal resistance layer (1) is coated on the outside of the thermal control object, and the thermal resistance layer (1) comprises a support frame and a volatile material, wherein the volatile material is filled in the gap of the support frame, is used to provide thermal resistance in a ground environment, and is volatile in a vacuum environment; The insulating layer (3) is coated on the outside of the thermal resistance layer (1) and is used to isolate the thermal resistance layer (1) from the external atmosphere in a ground environment; the thermal radiation layer (2) is coated on the outside of the insulating layer (3) and is used to block external thermal radiation heat flow in a vacuum environment. 2. The composite thermal control structure according to claim 1 is characterized in that, when the thermal control object is located in a vacuum environment, the volatile material in the thermal resistance layer (1) volatilizes, and the thermal radiation layer (2) is supported on the outer surface of the thermal control object by a supporting skeleton. 3. The composite thermal control structure according to claim 1 is characterized in that the heat radiation layer (2) comprises a plurality of stacked aluminum-plated thin film reflective layers, and the temperature of each layer of the aluminum-plated thin film reflective layer is different. 4. The composite thermal control structure according to claim 3 is characterized in that a woven spacer layer is arranged between the multiple stacked aluminum-plated film reflective layers, and the woven spacer layer is used to reduce the contact area between the aluminum-plated film reflective layers. 5. The composite thermal control structure according to claim 3 is characterized in that through holes are punched on the multiple layers of the aluminum-plated film reflective layer, and the through holes on each layer of the aluminum-plated film reflective layer are staggered. 6 . The composite thermal control structure according to claim 1 , wherein the volatile material comprises a solid volatile material or a semi-solid volatile material. 7. The composite thermal control structure according to claim 1, characterized in that the isolation layer (3) comprises a plastic film, and the support frame comprises an integrally formed carbon fiber frame. 8. A method for using a composite thermal control structure, characterized in that the composite thermal control structure according to any one of claims 1 to 7 is used, comprising the following steps: Ground environment use steps: the composite thermal control structure is placed in a normal pressure atmospheric environment, the isolation layer (3) seals the thermal resistance layer (1), and isolates the thermal resistance layer (1) from the atmosphere; The steps of using the composite thermal control structure in a vacuum environment are as follows: the composite thermal control structure is placed in a vacuum environment, the isolation layer (3) is broken, the volatile material of the thermal resistance layer (1) is volatilized, and the thermal radiation layer (2) is supported on the outer surface of the thermal control object by a supporting frame. 9. The method for using the composite thermal control structure according to claim 8, characterized in that, in the step of using the composite thermal control structure in a vacuum environment, the method for breaking the isolation layer (3) comprises any one of the following: Actively removing the isolation layer (3); Actively creating openings in the isolation layer (3); The original gas inside the isolation layer (3) destroys the isolation layer (3) during the process of external air pressure reduction. 10. A space cryogenic storage tank, characterized in that it comprises a spherical storage tank body, the outer surface of which is coated with the composite thermal control structure according to any one of claims 1 to 7.