Composite heat insulation structure of low-temperature storage tank and application method

Abstract

The invention discloses a low-temperature storage tank composite heat insulation structure and an application method. The composite thermal insulation structure includes: a first thermal insulation layer; a second heat insulating layer and a third heat insulating layer; the second heat insulation layer is located in a middle interlayer area defined by the first heat insulation layer and the third heat insulation layer. The composite heat insulation structure meets the air supply replacement requirement of the second heat insulation layer on the ground stage through the air supply module. According to the low-temperature storage tank composite heat insulation structure and the application method, the integration degree is high, efficient heat insulation in the ground stage and the space flight stage is achieved, washing of the rising stage can be borne, the low-temperature storage tank can be arranged outside a fairing, and the length and weight of the fairing are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of low-temperature storage tanks for launch vehicles, in particular to a composite thermal insulation structure of a low-temperature storage tank and an application method thereof. Background Art

[0002] Cryogenic propellants have low boiling points (liquid hydrogen at 20K, liquid oxygen at 90K) and easily evaporate due to external heat leakage, causing the temperature and pressure of the cryogenic propellant inside the tank to rise. To effectively control the temperature and pressure of the cryogenic tank during long-term gliding, the use of high-efficiency thermal insulation structures to reduce heat leakage is a key approach.

[0003] The cryogenic tanks of launch vehicles need to go through the ground parking stage, propellant filling stage, takeoff and ascent stage, space flight stage, etc., and need to adapt to efficient thermal insulation in atmospheric pressure environment and in orbit vacuum. Traditional thermal insulation for cryogenic tanks that are suitable for long-term gliding adopts a combination of foam and multi-layer insulation components. Since the multi-layer insulation components need to be prevented from low-temperature suction and ice and condensation after the propellant is filled on the ground, and cannot withstand the aerodynamic scouring of the ascent stage, the traditional cryogenic tanks for long-term gliding are placed inside the fairing, and air is supplied through the fairing to maintain the nitrogen atmosphere required on the ground. During the ascent stage, the fairing protects the multi-layer insulation components from damage by aerodynamic scouring. In order to place the cryogenic tank inside the fairing, the traditional solution needs to significantly increase the length and weight of the fairing, reducing the carrying capacity. Summary of the Invention

[0004] The present invention provides a composite thermal insulation structure of a low-temperature storage tank and an application method thereof, the purpose of which is to reduce the length and weight of a fairing and increase the carrying capacity of an aircraft.

[0005] In a first aspect, a composite thermal insulation structure for a cryogenic storage tank is provided, characterized in that it comprises:

[0006] The first insulation layer is sprayed on the outside of the low-temperature storage tank wall;

[0007] A second thermal insulation layer is attached to the outer side of the first thermal insulation layer;

[0008] The third insulation layer is placed on the outside of the second insulation layer and is used to withstand the aerodynamic scour load of the ascending stage of the carrier rocket. The third insulation layer is provided with a boss structure on two side edges and one bottom edge; the boss structure is bonded to the first insulation layer, and the third insulation layer is bonded to the first insulation layer to form an intermediate interlayer space. The second insulation layer is located in the intermediate interlayer space, and the second insulation layer and the third insulation layer are spaced apart from the area other than the boss structure. When the composite insulation structure is on the ground, the intermediate interlayer space is used to introduce nitrogen. After the composite insulation structure enters a space vacuum state, the second insulation layer in the intermediate interlayer space is in a vacuum state.

[0009] In combination with the first aspect, in certain implementations of the first aspect, the third insulation layer is provided with a plurality of exhaust holes, and the exhaust holes are in gas communication with the open end of the intermediate interlayer space.

[0010] In combination with the first aspect, in certain implementations of the first aspect, the composite thermal insulation structure includes an insulating structure air supply main line (9) and an insulating structure air supply ring pipe (7); the composite thermal insulation structure realizes nitrogen air supply to the intermediate interlayer space (5) through an air supply module; the nitrogen output by the air supply module first enters the insulating structure air supply main line (9) and then enters the insulating structure air supply ring pipe (7); the insulating structure air supply ring pipe (7) is located at the open end of the intermediate interlayer space (5), and a plurality of air supply holes (8) are provided on the side wall of the insulating structure air supply ring pipe (7) facing the open end of the intermediate interlayer space (5); the nitrogen enters the intermediate interlayer space (5) through the air supply holes (8) and is finally discharged to the surrounding environment from the exhaust hole (10) of the third insulating layer (4).

[0011] In combination with the first aspect, in certain implementations of the first aspect, the air supply module includes a ground air source (11), a ground air supply pipeline (12), and a plug-in connector (13); when nitrogen air is supplied for replacement, the ground air source (11) provides nitrogen, and the nitrogen enters the insulation structure air supply main pipeline (9) after passing through the ground air supply pipeline (12); before takeoff, the plug-in connector (13) is disconnected from the ground air supply pipeline (12).

[0012] In combination with the first aspect, in certain implementations of the first aspect, a plurality of modular prefabricated structures of the second thermal insulation layer and the third thermal insulation layer are continuously arranged along the circumferential direction outside the first thermal insulation layer.

[0013] In combination with the first aspect, in certain implementations of the first aspect, the second thermal insulation layer and the first thermal insulation layer may be bonded together by Velcro.

[0014] In combination with the first aspect, in certain implementations of the first aspect, the first thermal insulation layer is a foam thermal insulation layer.

[0015] In combination with the first aspect, in certain implementations of the first aspect, the second insulation layer is a variable density multi-layer insulation assembly.

[0016] In combination with the first aspect, in certain implementations of the first aspect, the third insulation layer is a foam insulation layer.

[0017] In a second aspect, a method for applying the composite insulation structure of a cryogenic storage tank as described in any one of the implementations of the first aspect is provided, comprising:

[0018] Before filling the cryogenic tank on the ground, carry out ground nitrogen air replacement;

[0019] After the replacement is completed, cryogenic propellant filling is carried out. Until takeoff, the air supply module maintains nitrogen air supply to keep the second insulation layer in a nitrogen atmosphere;

[0020] Stop nitrogen injection during takeoff.

[0021] Compared with the prior art, the solution provided by the present invention includes at least the following beneficial technical effects:

[0022] The embodiment of the present invention provides a composite insulation structure for a cryogenic tank with high integration, achieving efficient insulation during the ground and space flight phases, and being able to withstand scouring during the ascent phase, so that the cryogenic tank can be placed outside the fairing, reducing the length and weight of the fairing. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural diagram of the composite insulation structure and air supply system implemented on the low-temperature storage tank.

[0024] Figure 2 Schematic diagram of the cross section of the composite insulation structure.

[0025] Explanation of the accompanying symbols: low-temperature storage tank 1, first insulation layer 2, second insulation layer 3, third insulation layer 4, intermediate interlayer space 5, boss structure 6, insulation structure air supply ring pipe 7, air supply hole 8, insulation structure air supply main line 9, exhaust hole 10, ground air source 11, ground air supply pipeline 12, plug-in connector 13. DETAILED DESCRIPTION

[0026] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0027] Reference Figure 1 and Figure 2 As shown, the present invention provides a composite insulation structure for a cryogenic storage tank, comprising a first insulation layer 2, a second insulation layer 3, and a third insulation layer 4. For ease of implementation, multiple modular prefabricated structures of the second insulation layer 3 and the third insulation layer 4 are continuously arranged circumferentially outside the first insulation layer 2.

[0028] The first insulation layer 2 is sprayed onto the exterior wall of the cryogenic storage tank 1. The first insulation layer 2 is a foam insulation layer. The second insulation layer 3 is a variable-density multi-layer insulation assembly, applied to the exterior of the first insulation layer 2. The second insulation layer 3 can be prefabricated into a single insulation assembly according to modular design dimensions. The second insulation layer 3 and the first insulation layer 2 can be bonded together using Velcro. The third insulation layer 4 is positioned outside the second insulation layer 3 to withstand the aerodynamic scour loads of the launch vehicle's ascent phase. The third insulation layer 4 can be a modular prefabricated structure made of foam insulation. The third insulation layer 4 is provided with boss structures 6 on two side edges and one bottom edge. The boss structures 6 are bonded to the first insulation layer 2. The bonding of the third insulation layer 4 and the first insulation layer 2 creates an intermediate interlayer space 5. The second insulation layer 3 is located within this intermediate interlayer space 5, and the second insulation layer 3 and the third insulation layer 4 are separated from each other in areas other than the boss structures 6. A plurality of exhaust holes 10 are provided at the bottom end of the third heat-insulating layer 4 , and the exhaust holes 10 are in gas communication with the open end of the middle interlayer space 5 .

[0029] In some embodiments, the cryogenic storage tank composite insulation structure further includes an insulation structure air supply main line 9 and an insulation structure air supply loop 7. The cryogenic storage tank composite insulation structure can supply air to the intermediate interlayer space 5 through the air supply module, preventing frost and condensation caused by moisture absorption from the second insulation layer 3 in the intermediate interlayer space 5.

[0030] like Figure 1 As shown, the air supply module includes a ground air source 11, a ground air supply pipeline 12, and a plug-in connector 13. The ground air source 11 provides nitrogen, which enters the insulation structure air supply main pipeline 9 after passing through the ground air supply pipeline 12, and then enters the insulation structure air supply ring pipe 7. The insulation structure air supply ring pipe 7 is located at the open end of the intermediate interlayer space 5. The insulation structure air supply ring pipe 7 has multiple air supply holes 8 on the side wall facing the open end of the intermediate interlayer space 5. The nitrogen enters the intermediate interlayer space 5 through the air supply holes 8 and is finally discharged to the surrounding environment through the exhaust holes 10 of the third insulation layer 4.

[0031] The present invention also provides an application method of a composite insulation structure for a cryogenic storage tank. Some time before the ground refueling of the cryogenic storage tank 1, the ground nitrogen air supply replacement is started through the above-mentioned air supply module. After the replacement is completed, the cryogenic propellant is filled. During the filling process, the first insulation layer 2 plays an insulating role under normal pressure to reduce the evaporation of the cryogenic propellant; until before takeoff, the air supply module keeps supplying air, and the air is finally discharged through the exhaust holes 10 of the third insulation layer 4, keeping the second insulation layer 3 in a nitrogen atmosphere. Before takeoff, the ground air supply pipeline 12 is disconnected through the plug-in connector 13; during takeoff, the third insulation layer 4 bears the aerodynamic scour load of the carrier rocket's ascending stage; after entering the space vacuum state, the exhaust holes 10 of the third insulation layer 4 discharge the residual gas in the intermediate interlayer space 5, so that the second insulation layer 3 in the intermediate interlayer space 5 is in a vacuum state, achieving its efficient insulation.

[0032] The composite insulation structure of the cryogenic tank provided by the present invention has a high degree of integration, realizes efficient insulation in the ground stage and the space flight stage, and can withstand the scouring of the ascent stage, so that the cryogenic tank can be placed outside the fairing, reducing the length and weight of the fairing.

[0033] Although the present invention is disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined by the claims of the present invention.

Claims

1. A composite thermal insulation structure for a low-temperature storage tank, characterized in that: include: A first heat-insulating layer (2) is sprayed on the outer wall of the cryogenic storage tank (1); A second heat-insulating layer (3) is attached to the outer side of the first heat-insulating layer (2); The third insulation layer (4) is arranged outside the second insulation layer (3) and is used to bear the aerodynamic scour load of the ascending stage of the carrier rocket. The third insulation layer (4) is provided with a boss structure (6) on both sides and one bottom side. The boss structure (6) is bonded to the first insulation layer (2). After the third insulation layer (4) and the first insulation layer (2) are bonded, an intermediate interlayer space (5) is formed. The second insulation layer (3) is located in the intermediate interlayer space (5), and the second insulation layer (3) and the third insulation layer (4) are spaced apart from the boss structure (6). When the composite insulation structure is on the ground, nitrogen is introduced into the intermediate interlayer space (5). After the composite insulation structure enters a vacuum state, the second insulation layer (3) in the intermediate interlayer space (5) is in a vacuum state.

2. The composite thermal insulation structure according to claim 1, characterized in that: The third heat-insulating layer (4) is provided with a plurality of exhaust holes (10), and the exhaust holes (10) are in gas communication with the open end of the middle interlayer space (5).

3. The composite thermal insulation structure according to claim 1, characterized in that: The composite thermal insulation structure comprises an insulation structure air supply main line (9) and an insulation structure air supply ring pipe (7); the composite thermal insulation structure realizes nitrogen air supply in the middle interlayer space (5) through an air supply module; the nitrogen output by the air supply module first enters the insulation structure air supply main line (9) and then enters the insulation structure air supply ring pipe (7); the insulation structure air supply ring pipe (7) is located at the open end of the middle interlayer space (5); a plurality of air supply holes (8) are provided on the side wall of the insulation structure air supply ring pipe (7) facing the open end of the middle interlayer space (5); the nitrogen enters the middle interlayer space (5) through the air supply holes (8) and is finally discharged to the surrounding environment from the exhaust hole (10) of the third insulation layer (4).

4. The composite thermal insulation structure according to claim 3, characterized in that: The air supply module comprises a ground air source (11), a ground air supply pipeline (12), and a plug-in connector (13); during nitrogen air supply replacement, the ground air source (11) provides nitrogen, and the nitrogen enters the heat-insulating structure air supply main pipeline (9) after passing through the ground air supply pipeline (12); before takeoff, the plug-in connector (13) is disconnected from the ground air supply pipeline (12).

5. The composite thermal insulation structure according to claim 1, characterized in that: A plurality of modular prefabricated structures of the second thermal insulation layer (3) and the third thermal insulation layer (4) are continuously arranged along the circumferential direction outside the first thermal insulation layer (2).

6. The composite thermal insulation structure according to claim 1, characterized in that: The second heat-insulating layer (3) and the first heat-insulating layer (2) can be bonded together by Velcro.

7. The composite thermal insulation structure according to claim 1, characterized in that: The first heat insulating layer (2) is a foam heat insulating layer.

8. The composite thermal insulation structure according to claim 1, characterized in that: The second thermal insulation layer (3) is a variable density multi-layer thermal insulation component.

9. The composite thermal insulation structure according to claim 1, characterized in that: The third thermal insulation layer (4) is a foam thermal insulation layer.

10. A method for using the composite insulation structure of a low-temperature storage tank according to any one of claims 1 to 9, characterized in that: include: Before filling the cryogenic storage tank (1) on the ground, nitrogen air is supplied and replaced on the ground; After the replacement is completed, cryogenic propellant filling is carried out, and until takeoff, the air supply module maintains nitrogen air supply, so that the second insulation layer (3) is in a nitrogen atmosphere; Stop nitrogen injection during takeoff.

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