JP2013228060A - Double pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double pipe having high thermal insulation properties and reducing its damage rate.SOLUTION: A double pipe includes an inner pipe 3 for allowing an internal fluid to pass through the inside and an outer pipe 4 provided on an outer circumference of the inner pipe 3. An enclosed fluid is enclosed between the inner pipe 3 and the outer pipe 4. When it does not pass through the inside of the inner pipe 3, the internal fluid is assumed as a vaporization state. When the internal fluid passes through the inside of the inner pipe 3 and the enclosed fluid is cooled down to the neighborhood of the liquid temperature of the internal fluid, the enclosed fluid is solidified.

Description

  The present invention particularly relates to a double tube used in transferring a cryogenic fluid.

  A pipe used for transferring a cryogenic fluid such as liquid hydrogen is required to have high heat insulating properties because the amount of evaporation increases when the amount of heat input increases, resulting in a loss.

  Therefore, conventionally, as shown in FIG. 2, the metal flexible hoses 23 and 24 made of a metal bellows are doubled and the space between the flexible hoses 25 is in a vacuum state to be insulated and used. Thus, in order to maintain the space between the flexible hoses 25 in a vacuum state, the metal flexible hoses 23 and 24 are made of a highly airtight metal material.

JP-A-4-254300

  However, the metal flexible hoses 23 and 24 made of a metal bellows as shown in FIG. 2 have a problem that they are vulnerable to external impact and have a high damage rate.

  This invention is made | formed in view of such a situation, Comprising: It aims at providing the double tube | pipe which has high heat insulation and can have impact resistance.

In order to solve the above problems, the double pipe of the present invention employs the following means.
That is, according to the double pipe according to the present invention, an inner pipe through which an internal fluid passes and an outer pipe provided on the outer periphery of the inner pipe are provided between the inner pipe and the outer pipe. The sealed fluid is sealed, and when the internal fluid does not pass through the inner tube, the sealed fluid is in a vaporized state, and the internal fluid passes through the inner tube and When the sealed fluid is cooled to near the liquid temperature of the internal fluid, it is solidified.

  When the internal fluid does not pass through the inner pipe, the inner pipe and the outer pipe are in a vaporized state. In some cases, the solidified sealing fluid was sealed. As a result, when the sealed fluid is solidified, the inner tube and the outer tube can be insulated from each other by a vacuum state. When the sealed fluid is in a gas state, the gas is interposed between the inner tube and the outer tube. Since the sealed fluid is in a state, the atmosphere can be prevented from flowing into the space between the inner tube and the outer tube from the outer periphery of the double tube. Therefore, it is possible to use an outer tube made of a material excellent in impact resistance without using a conventionally used outer tube made of a highly airtight material. Therefore, the damage rate of the double pipe can be reduced.

  According to the double tube of the present invention, the outer tube is made of resin.

  A resin outer tube was used. Therefore, even when an impact is generated on the outer tube from the outside, deformation of the outer tube can be allowed. Therefore, the damage rate of the double pipe can be reduced.

  The double pipe according to the present invention is characterized in that the sealed fluid is at normal pressure or higher in a vaporized state.

  The sealed fluid was set to normal pressure or higher in the vaporized state. Thereby, the pressure difference between the sealed fluid between the outer tube and the inner tube and the atmosphere on the outer periphery of the outer tube can be made substantially equal or higher in the sealed fluid. For this reason, it is possible to prevent the air from flowing between the outer tube and the inner tube through the resin. Therefore, it is possible to suppress a decrease in heat insulation due to the sealed fluid between the outer tube and the inner tube.

  The double tube according to the present invention is characterized in that the outer tube and / or the inner tube are flexible.

  The outer tube and / or inner tube was made flexible. Thereby, it can be set as the double tube excellent in vibration and expansion / contraction.

  According to the present invention, between the inner tube and the outer tube, when the internal fluid does not pass through the inner tube, the inner tube is in a vaporized state. The sealed fluid that solidifies when cooled to near the temperature was sealed. As a result, when the sealed fluid is solidified, the inner tube and the outer tube can be insulated from each other by a vacuum state. When the sealed fluid is in a gas state, the gas is interposed between the inner tube and the outer tube. Since the sealed fluid is in a state, the atmosphere can be prevented from flowing into the space between the inner tube and the outer tube from the outer periphery of the double tube. Therefore, it is possible to use an outer tube made of a material excellent in impact resistance without using a conventionally used outer tube made of a highly airtight material. Therefore, the damage rate of the double pipe can be reduced.

The umbilical flexible hose used when filling the rocket which concerns on this embodiment with fuel is shown, (A) is the fragmentary longitudinal cross-section block diagram, (B) is the cross section in the aa part of (A). It is a block diagram. It is a fragmentary longitudinal cross-section block diagram of the conventional flexible hose.

Hereinafter, the configuration of an umbilical flexible hose according to an embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 1, an umbilical flexible hose (double tube) 1 is provided on the outer periphery of an inner tube bellows (inner tube) 3 through which liquid hydrogen, which is an internal fluid in a liquid state, passes and an inner tube bellows 3. A flexible tube (outer tube) 4 is provided. Between the inner tube bellows 3 and the flexible tube 4, carbon dioxide (encapsulated fluid) in a gas state (vaporized state) is enclosed.

  The umbilical flexible hose 1 of this embodiment is used when, for example, a rocket (not shown) is filled with liquid hydrogen as fuel. The umbilical flexible hose 1 is structured to be detached from the rocket when the rocket is launched.

  The inner tube bellows 3 is provided on the inner periphery of the flexible tube 4 so as to be substantially concentric with the flexible tube 4 and is flexible.

  The flexible tube 4 is provided on the outer peripheral side of the inner tube bellows 3. The flexible tube 4 is formed of a resin such as a polyethylene film, for example. The outer periphery of the flexible tube 4 is covered with a net-like outer wire 4a. Further, a net-like inner wire 4 b is also provided on the inner peripheral side of the flexible tube 4 along the inner peripheral wall. The flexible tube 4 is tightened from the outer peripheral side and the inner peripheral side by the outer wire 4a and the inner wire 4b to form a bellows-like flexible tube as shown in FIG.

  These space portions 5 between the inner tube bellows 3 and the flexible tube 4 are filled with gaseous carbon dioxide. Carbon dioxide sealed in the space 5 has a purity of about 95% or more. The carbon dioxide enclosed in this manner is sealed in the space part 5 at a normal pressure (normal pressure or higher) in a gas state so that the space part 5 does not become a negative pressure. As a result, even when liquid hydrogen does not pass through the inner tube bellows 3 as will be described later, the resin forming the outer tube 3 is permeated to the space 5 and the outer periphery of the umbilical flexible hose 1 is Inflow of air can be suppressed.

  In the case of filling the rocket with liquid hydrogen using the umbilical flexible hose 1 having such a structure, the gas state dioxide gas sealed in the space 5 by the cryogenic liquid hydrogen passing through the inside of the inner tube bellows 3 is used. The carbon is cooled. When liquid hydrogen passes through the inner tube bellows 3 and the gaseous carbon dioxide is cooled to near the liquid temperature of the liquid hydrogen, the carbon dioxide is solidified.

  As the carbon dioxide in a gas state sealed in the space portion 5 is solidified, the space portion 5 is in a vacuum state. When the inside of the space portion 5 is in a vacuum state, the heat insulating performance for insulating heat from the outer periphery of the umbilical flexible hose 1 is improved.

  Here, the degree of vacuum in the space portion 5 due to the solidification of carbon dioxide is affected by the remaining gas component that does not solidify. However, as described above, a decrease in the degree of vacuum can be prevented by setting the purity of the carbon dioxide sealed in the space 5 to about 95% or more.

As described above, according to the umbilical flexible hose 1 according to the present embodiment, the following operational effects can be obtained.
Between the inner tube bellows (inner tube) 3 and the flexible tube (outer tube) 4, when liquid hydrogen (inner fluid) does not pass through the inner tube bellows 3, it is in a gas state (vaporized state), When liquid hydrogen passes through the inner tube 2 and the inner tube bellows 3 and is cooled to near the liquid temperature of the liquid hydrogen, carbon dioxide that is solidified (encapsulated fluid) is sealed. When solidified, the space portion 5 (between the inner tube bellows 3 and the flexible tube 4) can be insulated by being in a vacuum state. When carbon dioxide is in a gas state, the space portion 5 is in a gas state. Since it has carbon dioxide, it can suppress that air | atmosphere flows in into the space part 5 from the outer periphery of the umbilical flexible hose (double pipe | tube) 1. FIG. Therefore, a material having excellent impact resistance, for example, a resin flexible tube 4 can be used without using a highly airtight material, for example, a metal flexible tube (not shown). . Therefore, the damage rate of the umbilical flexible hose 1 can be reduced.

  Resin flexible tube 4 was used. Therefore, when the rocket (not shown) launches, the flexible tube 4 comes off the rocket and collides with the mast (not shown) of the launch pad (not shown) (impact from outside). However, the deformation of the flexible tube 4 can be allowed. Therefore, the damage rate of the umbilical flexible hose 1 can be reduced.

  Carbon dioxide was brought to atmospheric pressure (normal pressure or higher) in a gaseous state. Thereby, the pressure difference of the carbon dioxide of the space part 5 and the outer periphery of the flexible tube 4 can be made substantially equivalent (substantially equivalent or the space part 5 has a higher pressure). Therefore, it is possible to prevent the air from flowing into the space portion 5 from the flexible tube 4 through the resin. Therefore, the heat insulation fall by the carbon dioxide of the space part 5 can be suppressed.

  The flexible tube 4 and / or the inner tube bellows 3 are made flexible. Thereby, it can be set as the umbilical flexible hose 1 excellent in vibration and expansion / contraction.

In this embodiment, liquid hydrogen is used as the internal fluid. However, the present invention is not limited to this, and liquid oxygen may be used.
The sealed fluid may be any fluid that solidifies when the sealed fluid reaches the liquid temperature due to the internal fluid, and may be ammonia, for example.
Further, the double pipe is not limited to the umbilical flexible hose 1.

  In addition, although it has been described that carbon dioxide, which is normal pressure in a gas state, is sealed in the space portion 5 of the umbilical flexible hose 1 and sealed, as a modification, the sealed fluid in the space portion 5 is replaced. For example, a joint portion (not shown) may be provided on a part of the outer periphery of the flexible tube 4.

1 Double pipe (umbilical flexible hose)
3 Inner pipe (inner pipe bellows)
4 Outer tube (flexible tube)

Claims (4)

An inner pipe through which the internal fluid passes;
An outer tube provided on the outer periphery of the inner tube,
Between the inner tube and the outer tube, a sealed fluid is sealed,
When the internal fluid does not pass through the inner pipe, the sealed fluid is in a vaporized state, and the internal fluid passes through the inner pipe and the sealed fluid is in the vicinity of the liquid temperature of the internal fluid. A double tube characterized by solidifying when cooled down.   The double pipe according to claim 1, wherein the outer pipe is made of resin.   The double pipe according to claim 2, wherein the sealed fluid is at normal pressure or higher in a vaporized state. The double tube according to any one of claims 1 to 3, wherein the outer tube and / or the inner tube is flexible.

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