JP6216297B2 - Insertion connection structure, refrigerant piping, and superconducting equipment - Google Patents

Description

  The present invention relates to an insertion type connection structure used in a state where a cryogenic liquid refrigerant is disposed therein, and a refrigerant pipe and a superconducting device using the insertion type connection structure.

  A refrigerant container in which a cryogenic liquid refrigerant is disposed, and an insertion member partially inserted into the open end of the refrigerant container are connected, and the refrigerant container and the insertion member are There is known an insertion type connection structure in which a clearance is formed at a portion overlapping in the insertion axis direction. In this insertion type connection structure, the side of the clearance in which the refrigerant container is disposed in the insertion axis direction has a cryogenic temperature, and the side in which the insertion member is disposed in the insertion axis direction has a non-cryogenic temperature. For example, Patent Document 1 shows an example in which the insertion type connection structure is applied to a terminal structure of a superconducting cable.

  FIG. 8 is a schematic half vertical sectional view of the terminal structure 100 of the superconducting cable connecting the superconducting cable SC and the normal conducting lead 2. The superconducting cable SC has a configuration in which the cable core 4 is housed inside a cable heat insulating tube 5 having a double tube structure (simplified and shown as a single tube structure in the drawing). A typical cable core 4 includes a former, a superconducting conductor layer 41, an internal semiconductive layer, a cable insulating layer 42, an external semiconductive layer, a cable shielding layer 43, and a protective layer (in the drawing, the layer 41, Only 42 and 43 are shown).

  The terminal structure 100 of the superconducting cable SC used at an extremely low temperature includes a joint-shaped heat insulating structure 3 including a cable side heat insulating container 31, a lead side heat insulating container 32, and an insulating member 33. The cable-side heat insulation container 31 is provided at the end in the lead direction of the cable heat insulation pipe 5 of the superconducting cable SC. The lead side heat insulating container 32 is attached to the end of the normal conducting lead 2 in the core direction. The end portion in the core direction of the lead side heat insulating container 32 is inserted into the end portion in the lead direction of the cable side heat insulating container 31, and the end portions of both the heat insulating containers 31, 32 are inserted in the direction of the insertion axis of both the heat insulating containers 31, 32. It overlaps (up and down direction on the page). The insulating member 33 is interposed in an overlap portion between the cable side heat insulating container 31 and the lead side heat insulating container 32, and the cable side heat insulating container 31 having a ground potential, and the lead side heat insulating container 32 having a high potential. , Exhibit a predetermined insulation performance. The insulating member 33 is formed integrally with the lead-side heat insulating container 32. The insulating member 33 may be formed integrally with the cable-side heat insulating container 31.

  In the above configuration, a clearance (a radial gap between the members) is formed between the insulating member 33 and the cable-side heat insulating container 31 and between the lead-side heat insulating container 32 and the normal conducting lead 2. That is, in this terminal structure 100, an insertion type connection structure in which a part of the insulating member 33 is inserted into the opening end of the cable-side heat insulating container 31, and a part of the normal conducting lead 2 is inserted into the opening end of the lead-side heat insulating container 32 It can be considered that the insertion type connection structure is formed. Incidentally, when the insulating member 33 is formed integrally with the cable-side heat insulating container 31, an insertion type connection structure in which the lead-side heat insulating container 32 is inserted into the opening end of the insulating member 33 is formed.

  Of the clearance of the insertion type connection structure, the end of the member in the insertion axis direction on the cable side (the lower side in the drawing) faces the inside of the heat insulating structure 3 and is in a cryogenic state by the liquid refrigerant 10L. . On the other hand, the end of the clearance in the insertion axis direction on the lead side (upper side in the drawing) faces the outside of the heat insulating structure 3 and is in a non-cryogenic state where the temperature is higher than the cryogenic temperature. . The vicinity of the end portion of the non-cryogenic side 1HS of the clearance is sealed so that the inside and outside of the heat insulating structure 3 do not communicate with each other through the clearance.

  In the clearance, there is heat penetration from the non-cryogenic side 1HS of the clearance. Therefore, the liquid refrigerant 10L that has entered the clearance from the cryogenic temperature side 1LS is vaporized by heat penetration from the non-cryogenic temperature side 1HS, and a temperature gradient along the insertion axis direction is formed in the clearance. If this temperature gradient is steep, the movement of heat through the clearance increases, and if the temperature gradient is loose, the movement of heat through the clearance decreases.

JP 2013-59211 A

  In order to stabilize the boundary position between the liquid refrigerant and the vaporized gas in the clearance and form a gradual temperature gradient in the clearance, if the clearance length in the insertion axis direction is the same, It is effective to reduce the vaporized gas, that is, to make the clearance as narrow as possible. However, when the heat insulation container is enlarged, the clearance must be increased so that the insertion member can be inserted into the end of the refrigerant container even if the dimensional variation or distortion of each component member occurs. When the clearance becomes large, it is difficult to form a gentle temperature gradient in the clearance, and problems such as increased heat penetration through the clearance arise.

  In addition, when the insertion axis direction is inclined from the vertical direction, such as when the insertion axis direction is oriented horizontally, when the insertion type connection structure is filled with liquid refrigerant, the vertical lower side of the clearance The liquid refrigerant flows into the clearance from this part. Although the liquid refrigerant is vaporized in the clearance, the vaporized gas escapes from the vertically upper side of the clearance to the inside of the insertion-type connection structure, and thus the force to push back the liquid refrigerant flowing in from the vertically lower side of the clearance is hard to work. Therefore, the inflow of the liquid refrigerant to the clearance is difficult to be suppressed, and it is difficult to form a gentle temperature gradient in the clearance. Similarly, even if the insertion axis direction is the vertical direction, when the non-cryogenic side of the clearance is directed vertically downward (that is, when the configuration of FIG. 8 is upside down), the liquid refrigerant to the clearance Since inflow is difficult to suppress, it is difficult to form a gentle temperature gradient in the clearance.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide a gentle temperature gradient in the clearance formed between the refrigerant container and the insertion member inserted into the opening end of the refrigerant container. It is to provide an insertion type connection structure that can be formed.

  An insertion type connection structure according to an aspect of the present invention connects a refrigerant container in which a cryogenic liquid refrigerant is disposed, and an insertion member, a part of which is inserted into an open end of the refrigerant container. Of the clearance formed in a portion where the refrigerant container and the insertion member overlap in the insertion axis direction, the side on which the refrigerant container is arranged in the insertion axis direction becomes extremely low temperature, and the insertion member is The present invention relates to an insertion type connection structure in which the side to be arranged is non-cryogenic. This insertion type connection structure includes an inlet forming member provided at a position in contact with the liquid refrigerant on the cryogenic temperature side in the clearance, and forming a refrigerant inlet at a part of the clearance in the circumferential direction. .

  According to the insertion type connection structure, a gentle temperature gradient can be formed in the clearance between the refrigerant container and the insertion member.

It is a schematic longitudinal cross-sectional view which shows the basic composition of an insertion type connection structure. It is a schematic explanatory drawing of the insertion type connection structure using the hollow elongate body shown in Embodiment 1. FIG. It is a schematic explanatory drawing explaining the state of the liquid refrigerant in a bottleneck. It is a schematic explanatory drawing of the insertion type connection structure using the corrugated board material shown in Embodiment 3. It is a schematic explanatory drawing of the insertion type connection structure using the solid elongate body shown in Embodiment 4. It is a schematic explanatory drawing of the insertion type connection structure using the sealing member shown in Embodiment 5. It is an insertion type connection structure shown in Embodiment 7, Comprising: It is a schematic explanatory drawing of the insertion type connection structure applied to the terminal structure of a superconducting cable. It is a schematic explanatory drawing of the conventional insertion type connection structure in the terminal structure of a superconducting cable.

[Description of Embodiment of the Present Invention]
First, the contents of the embodiment according to the present invention will be listed and described.

The insertion type connection structure of <1> embodiment connects a refrigerant container in which a cryogenic liquid refrigerant is disposed, and an insertion member partially inserted into the open end of the refrigerant container. Among the clearances formed in the portion where the refrigerant container and the insertion member overlap in the insertion axis direction, the side where the refrigerant container is arranged in the insertion axis direction is extremely low temperature, and the insertion member is arranged This relates to an insertion type connection structure in which the side to be processed is non-cryogenic. This insertion type connection structure includes an inlet forming member provided at a position in contact with the liquid refrigerant on the cryogenic temperature side in the clearance, and forming a refrigerant inlet at a part of the clearance in the circumferential direction. .

  When the liquid refrigerant enters the clearance, the liquid refrigerant lowers the temperature of the gas part of the clearance and the liquid refrigerant vaporizes. This vaporized gas increases the volume of the gas part of the clearance. While the vaporization of the liquid refrigerant and the liquefaction of the gas part are balanced, the boundary between the liquid refrigerant and the gas part in the clearance is maintained. The exchange of heat between the liquid refrigerant and the gas part is accompanied by the movement of the boundary between the liquid refrigerant and the gas part in the clearance part, and a heat balance is generated according to the volume of the moving liquid refrigerant. If the volume of the moving liquid refrigerant is small, the heat balance is also small, and the position of the boundary is stabilized. Therefore, like the insertion type connection structure according to the above-described embodiment, by arranging the inlet forming member at a position where the liquid refrigerant contacts in the clearance and forming a narrow refrigerant inlet, the liquid refrigerant and the gas portion The boundary position can be stabilized at a position closer to the cryogenic temperature side. As a result, the temperature gradient of the clearance can be moderated and the increase in intrusion heat can be suppressed.

<2> As an embodiment of the insertion type connection structure of the embodiment, the inflow port forming member partitions the clearance in the circumferential direction to form a bottleneck that extends from the cryogenic side toward the non-cryogenic side. It is a member, Comprising: The form in which the said refrigerant | coolant inflow port is formed by the edge part of the said cryogenic temperature side of the said bottleneck can be mentioned. In the insertion type connection structure of this embodiment, the end portion on the non-cryogenic side of the bottleneck is closed.

  By forming a bottleneck that is closed on the non-cryogenic side, when the liquid refrigerant that has entered the bottleneck from the cryogenic side vaporizes, the volume of the gas part in the bottleneck expands, and the liquid refrigerant is cooled to the cryogenic side by the gas part. Pressed. As a result, the boundary between the liquid refrigerant and the gas part in the bottleneck, that is, the boundary between the liquid refrigerant and the gas part in the clearance is stabilized at a position closer to the cryogenic temperature side. If the cross-sectional area of the bottleneck is not more than a predetermined cross-sectional area, it is possible to make it difficult for liquid refrigerant to enter the bottleneck by the action of surface tension.

<3> As one form of the insertion type connection structure of an embodiment provided with a partition member, the said partition member can mention the form which is a hollow elongate body.

  By forming the hollow long body in the clearance so that the axial direction of the hole is along the insertion axis direction of the insertion type connection structure, a narrow path extending from the cryogenic temperature side to the non-cryogenic temperature side in the clearance is formed. Can do. For example, when a plurality of hollow long bodies are arranged in the circumferential direction of the clearance, a hole between each hollow long body and a gap between adjacent hollow long bodies becomes a bottleneck. The hollow long body is preferably elastic in the thickness direction, and is preferably inserted into the clearance in a state where the hollow long body is deformed. As shown in Embodiment 1 described later, the outer peripheral surface of the hollow long body can be brought into close contact with the member forming the clearance, and each bottleneck constituted by the gaps between adjacent hollow long bodies is It is because it can suppress connecting. Further, the deformation of the hollow elongated body also contributes to reducing the clearance volume.

<4> As one form of the insertion type connection structure of an embodiment provided with a partition member, the said partition member can mention the form which is a corrugated board | plate material.

  A plurality of clearances along the insertion axis direction can be formed by arranging the corrugated plate material in the clearance such that the extending direction of the peak portion is along the insertion axis direction of the insertion type connection structure. Specifically, a bottleneck formed by a space surrounded by adjacent peaks in the corrugated plate material is formed in the clearance. The corrugated plate material may be a corrugated plate having a corrugated plate on both sides, or may have a corrugated plate only on one side of the plate. The corrugated plate material is also preferably elastic in the thickness direction, and is preferably inserted into the clearance in a deformed state.

<5> As one form of the insertion type connection structure of the embodiment including a partition member, the inflow port forming member spirals from the cryogenic side toward the non-cryogenic side by being spirally provided in the clearance. It is a partition member that forms a narrow channel extending in a shape, and the refrigerant inlet is formed by an end portion on the cryogenic side of the narrow channel. In the insertion type connection structure of this embodiment, the end portion on the non-cryogenic side of the bottleneck is closed.

  By forming a bottleneck that spirally extends from the cryogenic side toward the non-cryogenic side, and closing the end of the bottleneck on the non-cryogenic part side, the clearance for the same reason as in the above configuration <2> The boundary between the liquid refrigerant and the gas part is stabilized at a position closer to the cryogenic temperature side. As shown in Embodiment 4 described later, this configuration is particularly effective when the insertion axis direction is inclined from the vertical direction.

<6> As one form of the insertion type connection structure of an embodiment provided with a partition member, the form provided with the obstruction | occlusion member which obstruct | occludes the edge part of the said non-cryogenic temperature side of the said bottleneck can be mentioned.

  The non-cryogenic side of the bottleneck formed by the partition member can be closed by twisting or bending the non-cryogenic side of the partition member, for example. However, with such a method, there is a possibility that the bottleneck is not sufficiently blocked or that the blocked state is resolved over time. For such a problem, by using a closing member that is a separate member from the partition member in order to close the non-cryogenic side of the bottleneck, the end on the non-cryogenic side of the bottleneck can be reliably blocked. it can.

<7> As one form of the insertion type connection structure of an embodiment provided with a partition member, the said blocking member is a form comprised with the high viscosity material inject | poured into the position of the edge part of the said non-cryogenic temperature side in the said bottleneck. Can be mentioned.

  A high-viscosity material is preferable because it can be easily injected into the end portion of the non-cryogenic portion side of the bottleneck, and the end portion can be easily closed without a gap.

<8> As one form of the insertion type connection structure according to the embodiment, the inflow port formed by a seal member that seals the end portion on the cryogenic temperature side of the clearance, wherein the insertion axis direction is inclined from the vertical direction. A member may be provided, and the seal member may include a communication hole serving as the refrigerant inlet at the position of the lower end in the vertical direction.

  As already described in the problem section, when the insertion axis direction is inclined from the vertical direction, such as when the insertion axis direction of the insertion type connection structure is oriented in the horizontal direction, the inflow of liquid refrigerant into the clearance is difficult to be suppressed. . With respect to such a problem, in the configuration of <7> above, the end portion on the cryogenic temperature side of the clearance is sealed with the seal member, and the communication hole (refrigerant inlet) is intentionally placed at the position of the lower end in the vertical direction of the seal member. ) Is formed. In such a configuration, when the liquid refrigerant flows into the clearance from the communication hole and the liquid refrigerant is vaporized in the clearance, the seal member blocks the release of the vaporized gas into the refrigerant container. The internal pressure increases, and a force for pushing the liquid refrigerant out of the clearance is generated. As a result, the amount of liquid refrigerant in the clearance can be reduced. Further, in the configuration <8>, the possibility of breakage of the seal member can be reduced by forming the communication hole in the seal member. If the communication hole is not formed in the seal member, an excessive pressure difference may occur between the one surface side and the other surface side of the seal member, and the seal member may be damaged. This seal member is preferably used in combination with a partition member.

<9> The refrigerant pipe according to the embodiment is a refrigerant pipe configured by connecting a plurality of tubular heat insulating containers, and the connection structure of the two heat insulating containers to be connected to the insertion type connection structure of the above embodiment. It is refrigerant piping using.

  By applying the insertion type connection structure of the embodiment to the joint structure of the tubular heat insulating container in the refrigerant pipe, it is possible to suppress an increase in heat penetration through the joint between the two heat insulating containers.

The superconducting device according to the <10> embodiment is a superconducting device comprising a superconducting member and a vacuum heat insulating structure that covers the outer periphery of the superconducting member, and the insertion type of the above embodiment is part of the vacuum heat insulating structure. A superconducting device using a connection structure.

  By applying the insertion type connection structure of the embodiment to the vacuum heat insulating structure of the superconducting device, it is possible to suppress an increase in heat penetration through the joint between the two heat insulating containers in the vacuum heat insulating structure.

<11> As one form of the superconducting device of the embodiment, a form in which the superconducting member is a cable core of a superconducting cable can be mentioned.

  By applying the insertion type connection structure of the embodiment to the power line (superconducting equipment) using the superconducting cable, the intrusion heat to the superconducting cable can be reduced. The application part may be an intermediate connection part of a power line or a terminal connection part.

[Details of the embodiment of the present invention]
Hereinafter, the insertion type connection structure according to the embodiment and the refrigerant pipe using the insertion type connection structure will be described. In addition, a terminal structure of a superconducting cable using the insertion type connection structure according to the embodiment will be described as an example of a superconducting device using the insertion type connection structure. In addition, this invention is not necessarily limited to these illustrations, is shown by the claim, and intends that all the changes within the claim, the meaning equivalent, and the range are included.

<Embodiment 1>
Embodiment 1 demonstrates the example which applied the insertion type connection structure of embodiment to the nested joint structure in the refrigerant | coolant piping which distribute | circulates a cryogenic liquid refrigerant. In the description, first, a general basic configuration of the joint structure will be described with reference to FIG. 1, and the problems will be pointed out. Next, a configuration for solving the problems of the basic structure will be described with reference to FIGS.

≪Basic structure≫
FIG. 1 is a schematic longitudinal sectional view showing a basic configuration of a joint structure (hereinafter referred to as an insertion type connection structure 1) in which two vacuum heat insulating tubes are connected. In FIG. 1, the dimensions of each part of the insertion type connection structure 1 are exaggerated, and members and the like that maintain the connection of the insertion type connection structure 1 are not shown. As shown in FIG. 1, in the insertion type connection structure 1, the end of the vacuum heat insulating tube (insertion member) 12 is inserted into the end of the vacuum heat insulating tube (refrigerant container) 11. The ends are overlapped in the insertion axis direction and connected. An extremely low temperature liquid refrigerant 10L such as liquid nitrogen is circulated in the insertion type connection structure 1 applied to the refrigerant pipe.

  In this insertion type connection structure 1, a clearance 10 c is formed between the inner peripheral surface of the vacuum heat insulating tube 11 and the outer peripheral surface of the vacuum heat insulating tube 12 at a portion where the vacuum heat insulating tube 11 and the vacuum heat insulating tube 12 overlap. ing. Of the clearance 10c, the side facing the inside of the insertion type connection structure 1 in the insertion axis direction (left and right direction on the paper surface) of the vacuum heat insulating tubes 11 and 12, that is, the side on which the vacuum heat insulating tube 11 is disposed is poled by the liquid refrigerant 10L. The temperature is low. On the other hand, of the clearance 10c, the side facing the outside of the insertion type connection structure 1 in the insertion axis direction, that is, the side where the vacuum heat insulating tube 12 is arranged is sealed with a seal structure (not shown), and the liquid is passed through the clearance 10c. The refrigerant 10L does not leak. A part of the liquid refrigerant 10L that has entered the clearance 10c is vaporized, and a vaporized gas 10G is present in the clearance 10c. Hereinafter, the side facing the inside of the insertion type connection structure 1 in the insertion axis direction is referred to as a cryogenic side 1LS, and the side facing the outside of the insertion type connection structure 1 is referred to as a non-cryogenic side 1HS.

  In the clearance 10c, the vaporized gas 10G pushes back the liquid refrigerant 10L flowing into the clearance 10c, and a temperature gradient is formed in which the temperature gradually increases from the extremely low temperature side 1LS to the non-low temperature side 1HS of the clearance 10c. Yes. By this temperature gradient, an increase in heat penetration into the insertion type connection structure 1 via the clearance 10c is suppressed. As the boundary position between the liquid refrigerant 10L and the vaporized gas 10G moves to the non-low temperature side 1HS, the temperature gradient formed in the clearance 10c becomes steeper, and the effect of suppressing the increase in heat penetration becomes smaller.

  The clearance 10 c is formed by a dimensional difference between the inner diameter of the end of the vacuum heat insulating tube 11 and the outer diameter of the end of the vacuum heat insulating tube 12. In particular, when the tube diameters of both the vacuum heat insulating tubes 11 and 12 are increased, it is necessary to set the dimensional difference larger in consideration of the fitting property of the vacuum heat insulating tube 12 to the vacuum heat insulating tube 11. If the dimensional difference is increased, the clearance 10c is increased, and heat penetration through the clearance 10c is increased.

≪Configuration to solve problems of basic structure≫
In order to solve the problems of the above basic configuration, in this example, an insertion type connection structure 1α in which a plurality of hollow long bodies 13 are inserted into a clearance 10c as shown in FIG. FIG. 2 is a schematic explanatory view of the insertion type connection structure 1α schematically showing the arrangement state of the hollow long body 13 in the clearance 10c. In FIG. 2, the vacuum heat insulating tube 11 is indicated by a dotted line, and the clearance 10c is exaggerated.

  The hollow long body 13 is a partition member that partitions the clearance 10c in the circumferential direction. In this example, a plurality of the hollow long bodies 13 are arranged along the circumferential direction of the clearance 10c. The plurality of hollow long bodies 13 may be independent from each other, or may be integrally formed on one side of the sheet material. The hollow long body 13 has a function of forming a plurality of bottlenecks 13i extending from the cryogenic temperature side 1LS toward the non-cryogenic temperature side 1HS and reducing the volume of the clearance 10c. The end of the narrow path 13i formed by the hollow long body 13 at the end of the cryogenic temperature side 1LS that is in contact with the liquid refrigerant 10L allows inflow of the liquid refrigerant 10L from the inside of the insertion type connection structure 1α toward the clearance 10c. Functions as a refrigerant inlet 13e. The refrigerant inlet 13e has a narrow spot shape compared to the area of the cross section of the clearance 10c (the cross section perpendicular to the insertion axis direction of the heat insulating tubes 11 and 12).

  The bottleneck 13i formed by the hollow long body 13 will be described in more detail with reference to the encircled enlarged view of FIG. First, the hollow elongate body 13 has a hollow hole extending along its longitudinal direction, and a narrow path 13i is formed by the hollow hole (refer to FIG. 3 together). In addition, the hollow long body 13 in this example is elastically deformed and is in close contact with the inner peripheral surface of the vacuum heat insulating tube 11 and the outer peripheral surface of the vacuum heat insulating tube 12, so that the gap between adjacent hollow long members 13 is also increased. A bottleneck 13i is formed.

The refrigerant inflow port 13e that is an end opening of the extremely low temperature side 1LS of the bottleneck 13i has a function of suppressing the inflow of the liquid refrigerant 10L into the clearance 10c. As the area of the refrigerant inlet 13e becomes smaller, the influence of the surface tension becomes stronger, and the inflow of the liquid refrigerant 10L through the refrigerant inlet 13e is easily suppressed. The area of the refrigerant inlet 13e is preferably 20 mm ² or less, more preferably 15 mm ² or less, and most preferably 10 mm ² or less.

  On the other hand, a blocking member 13s is provided on the non-cryogenic side 1HS portion of the bottleneck 13i as shown in the longitudinal sectional view of FIG. The blocking member 13s has a function of sealing the vaporized gas 10G generated when the liquid refrigerant 10L flowing into the narrow passage 13i is vaporized into the narrow passage 13i. The closing member 13s may be provided in the hollow long body 13 in advance, or may be formed after the hollow long body 13 is inserted into the clearance 10c. For example, the closing member 13s is preferably formed of a high viscosity material such as silicone grease. In the case of a high-viscosity material, the blocking member 13s can be formed simply by inserting the hollow elongated body 13 into the clearance 10c and then injecting the high-viscosity material from the non-cryogenic side 1HS of the clearance 10c. Moreover, if it is a method which inject | pours a high-viscosity material into the clearance 10c, the edge part of the non-cryogenic side 1HS of the bottleneck 13i formed in the clearance gap (refer the encircled enlarged view of FIG. 2) of the adjacent hollow elongate body 13 is shown. Can be simultaneously occluded. In addition, the end portion may be closed by pushing a ring-shaped seal member into the end portion of the non-cryogenic side 1HS of the clearance 10c shown in FIG. The closing member arranged on the non-cryogenic side is not required to have the cryogenic resistance as required for the hollow elongated body 13. In addition, by increasing the amount of material injected into the non-cryogenic side 1HS and reducing the volume in the clearance 10c, the position of the boundary between the liquid refrigerant 10L and the vaporized gas 10G is moved closer to the cryogenic side 1LS. Can be expected.

  The hollow long body 13 forming the bottleneck 13i is preferably made of an elastic material that does not change in quality due to the liquid refrigerant and facilitates insertion into the clearance 10c. For example, silicone rubber, fluororesin, carbon fiber, or the like can be used as the material for the hollow elongated body 13. In addition, as a material for the hollow long body 13, a thin fibrous resin (for example, polyethylene or polypropylene) is made into a woven shape and then pressed one or more times, or a pipe shape is used. Can also be used. By using a fibrous resin, it can be used even at extremely low temperatures, and the elasticity of the hollow elongated body 13 can be increased. If the hollow long body 13 has elasticity, the hollow long body 13 can be inserted into the clearance 10c in a flattened state, and the inserted hollow long body 13 is brought into close contact with both the heat insulating tubes 11 and 12. Can do.

The dimension of the hollow long body 13 can be appropriately selected according to the clearance 10c. For example, the length of the hollow long body 13 may be shorter, the same, or longer than the length of the clearance 10c (length in the left-right direction on the paper surface). However, it is preferable to select the length of the hollow long body 13 so that the end of the hollow long body 13 (refrigerant inlet 13e) is arranged near the end of the cryogenic temperature side 1LS of the clearance 10c. . Moreover, it is preferable that the cross-sectional area of the hollow hole formed in the hollow elongate body 13 shall be 20 mm < ² > or less, for example. However, when the elastic hollow long body 13 is used, since the hollow hole of the hollow long body 13 inserted into the clearance 10c is deformed, the preferable cross-sectional area of the hollow hole is only a guide.

  The arrangement method of the hollow long body 13 in the clearance 10c is not particularly limited. For example, after inserting the vacuum heat insulation pipe | tube 12 into the edge part of the vacuum heat insulation pipe | tube 11, the hollow long body 13 can be arrange | positioned by inserting the hollow long body 13 in the clearance 10c. Alternatively, the vacuum heat insulating tube 12 is inserted into the end portion of the vacuum heat insulating tube 11 in a state where the hollow long body 13 is locked to the inner peripheral surface of the end portion of the vacuum heat insulating tube 11, or the outer peripheral surface of the end portion of the vacuum heat insulating tube 12 The hollow long body 13 can also be disposed in the clearance 10c by inserting the vacuum heat insulating tube 12 into the end of the vacuum heat insulating tube 11 with the hollow long body 13 being locked. In order to lock the hollow long body 13 to the heat insulating pipes 11 and 12, for example, a recess for fitting the hollow long body 13 into the heat insulating pipes 11 and 12 may be formed.

<< Effects of Embodiment >>
According to the insertion type connection structure 1α described above, a gentle temperature gradient can be formed in the clearance 10c. The main reason is as follows.

  In the insertion type connection structure 1 of the first embodiment, the hollow long body 13 is inserted into the clearance 10c, so that it comes into contact with the liquid refrigerant 10L on the cryogenic temperature side 1LS of the clearance 10c from the area of the cross section of the clearance 10c. A narrow refrigerant inlet 13e is formed. The narrow refrigerant inlet 13e is strongly influenced by the surface tension, so that it is difficult for the liquid refrigerant 10L to flow into the clearance 10c via the refrigerant inlet 13e.

  Further, in the insertion type connection structure 1 of the embodiment, a plurality of bottlenecks 13i are formed in the clearance 10c, and the non-cryogenic side 1HS of the bottleneck 13i is sealed with a closing member 13s (see FIG. 3). Thus, the position of the boundary between the liquid refrigerant 10L and the vaporized gas 10G in the clearance 10c can be stabilized. For example, if the bottle 13i formed inside the hollow long body 13 shown in FIG. 3 is described as an example, the liquid refrigerant 10L flows into the bottle 13i (that is, the clearance 10c) via the refrigerant inlet 13e. Then, the liquid refrigerant 10L is vaporized and the vaporized gas 10G is generated. Since the end of the non-cryogenic side 1HS of the bottleneck 13i is sealed by the closing member 13s, the vaporized gas 10G cannot escape outside the bottleneck 13i, and strongly pushes the liquid refrigerant 10L back to the refrigerant inlet 13e side. Therefore, it is difficult for the liquid refrigerant 10L to enter the clearance 10c, and the boundary position between the liquid refrigerant 10L and the vaporized gas 10G in the clearance 10c is more stable at the position 1LS on the cryogenic temperature side of the clearance 10c than in the conventional configuration. As a result, a gentle temperature gradient is formed in the clearance 10c, and an increase in heat penetration through the clearance can be suppressed.

  Furthermore, in the insertion type connection structure 1 of Embodiment 1, the some hollow elongate body 13 is inserted in the clearance 10c, and the volume of the clearance 10c is reduced. That is, the clearance 10c can be substantially reduced by the hollow elongated body 13. Therefore, the liquid refrigerant 10L and the vaporized gas 10G that can exist in the clearance 10c are reduced, and an increase in heat penetration through the clearance 10c can be suppressed.

<Embodiment 2>
Instead of the hollow long body 13 of the first embodiment, a solid long body (partition member) may be used. In that case, if a solid long body having a diameter larger than the width of the clearance 10c is inserted into the clearance 10c in a flattened state, a bottleneck is formed by the gap between the vacuum heat insulating tubes 11 and 12 and the solid long body. Can be formed. As a result, an effect similar to that of the configuration of the first embodiment can be obtained.

<Embodiment 3>
In the third embodiment, an insertion type connection structure 1β in which a corrugated plate member (partition member) 14 is inserted into the clearance 10c will be described with reference to FIG. 4 is the same as FIG. 2 of the first embodiment.

  The corrugated plate 14 is a partition member having a form different from that of the hollow long body 13 of the first embodiment, and forms a narrow path 14 i in the clearance 10 c like the hollow long body 13. The corrugated plate 14 of this example is a corrugated plate in which corrugations are formed on one side and the other side. As the material of the corrugated plate material 14, the same material that can be used for the hollow elongated body 13 can be used.

  When the corrugated plate material 14 is inserted into the clearance 10c, as shown in the enlarged circled view of FIG. 4, the crest portion on the one surface side of the corrugated plate material 14 contacts the inner peripheral surface of the vacuum heat insulating tube 11, and the vacuum The crest portion on the other surface side of the corrugated plate 14 contacts the outer peripheral surface of the heat insulating tube 12. As a result, a narrow path 14i configured by a space surrounded by the inner peripheral surface of the vacuum heat insulating tube 11 and the corrugated plate member 14 and a space surrounded by the outer peripheral surface of the vacuum heat insulating tube 12 and the corrugated plate member 14 are configured. A bottleneck 14i is formed in the clearance 10c. The end portion of the low temperature side 1LS of the bottleneck 14i functions as a refrigerant inlet 14e that allows the liquid refrigerant 10L to flow into the clearance 10c. The preferred area of the refrigerant inlet 14e is the same as the preferred area of the refrigerant inlet 13e described in the first embodiment.

  Although not shown, a blocking member is provided on the non-cryogenic side 1HS of the bottleneck 14i. As the closing member, those exemplified in the first embodiment can be used.

<< Effects of Embodiment >>
Also in the configuration of the third embodiment, the narrow refrigerant inlet 14e can be formed at a position where the volume of the clearance 10c is reduced by the corrugated plate member 14 and in contact with the liquid refrigerant 10L on the cryogenic temperature side 1LS of the clearance 10c. . Therefore, as in the first embodiment, an increase in heat penetration through the clearance 10c can be suppressed.

<Modified Embodiment 3-1>
Instead of the corrugated plate 14 of the third embodiment, a single corrugated plate in which at least one arch-shaped peak portion is arranged on one surface side of the flat plate can be used. For example, a corrugated plate formed by joining a peak portion on one surface side of a corrugated plate to one surface side of a flat plate can be used. In the case of such a single wave plate, it is preferable that both materials are made different so that the thermal expansion coefficient of the flat plate is larger than the thermal expansion coefficient of the peak portion. When such a corrugated plate is cooled to a very low temperature, the height of the peak portion becomes higher than before the cooling. This is because the amount of contraction of the flat plate is larger than the amount of contraction of the ridge at an extremely low temperature, so that the ridge is deformed as if it is raised. Such a single-wave material is easy to insert into the clearance, and the crest can be brought into close contact with the tube wall when cooled after being inserted.

<Embodiment 4>
In the fourth embodiment, an insertion type connection structure 1γ in which a solid long body (partition member) 15 is spirally arranged in a clearance 10c will be described with reference to FIG. 5 is the same as FIG. 2 of the first embodiment. The intermediate portion of the solid long body 15 is not shown.

  The solid long body 15 is spirally disposed in the clearance 10 c and is in close contact with the inner peripheral surface of the vacuum heat insulating tube 11 and the outer peripheral surface of the vacuum heat insulating tube 12. As a result, a spiral narrow path 15i is formed in the clearance between the turns of the solid long body 15 in the clearance 10c. The end portion of the extremely low temperature side 1LS of the spiral bottleneck 15i functions as a refrigerant inlet 15e that allows the liquid refrigerant 10L to flow into the clearance 10c. The preferred area of the refrigerant inlet 15e is the same as the preferred area of the refrigerant inlet 13e described in the first embodiment. On the other hand, although not shown, a blocking member is provided on the non-cryogenic side 1HS of the bottleneck 15i. As the closing member, those exemplified in the first embodiment can be used.

  The same material that can be used for the hollow long body 13 can be used as the material for the solid long body 15. By giving the solid elongate body 15 elasticity, the solid elongate body 15 can be brought into close contact with both the heat insulating pipes 11 and 12, and each turn of the bottleneck 15i extending spirally becomes independent. Here, a hollow long body can be used instead of the solid long body 15.

<< Effects of Embodiment >>
Also in the configuration of the fourth embodiment, the volume of the clearance 10c is reduced by the solid elongated body 15, and the narrow refrigerant inlet 15e is formed at a position in contact with the liquid refrigerant 10L on the cryogenic temperature side 1LS of the clearance 10c. Can do. Therefore, as in the first embodiment, an increase in heat penetration through the clearance 10c can be suppressed.

  Here, when the insertion axis direction is inclined from the vertical direction, the intrusion position of the liquid refrigerant 10L is closer to the non-cryogenic side 1HS in the vertically lower part than the vertically upper part of the clearance 10c, and the vertical Heat penetration through the clearance 10c tends to increase in the lower portion. On the other hand, in the configuration of the fifth embodiment in which the bottleneck 15i is spirally formed, the liquid refrigerant 10L moves spirally, so that the liquid refrigerant 10L enters between the vertically upper side and the vertically lower side of the clearance 10c. It is difficult to make a difference in position. Therefore, it is possible to suppress an increase in heat intrusion in the vertically lower portion of the clearance 10c.

<Embodiment 4-1>
There is no need for the single solid long body 15 to be spirally disposed in the clearance 10c. For example, two, three, or four or more solid elongated bodies 15 may be spirally arranged in the clearance 10c in a state where they are arranged in parallel. That is, another turn of the solid elongate body 15 may be arranged between the turns of a certain solid elongate body 15. In that case, a plurality of spiral bottlenecks 15i independent of each other are formed.

<Embodiment 5>
In the fifth embodiment, an insertion type connection structure 1δ in which a seal member 16 is provided on the cryogenic temperature side 1LS of the clearance 10c will be described with reference to FIG. 6 is the same as FIG. 2 of the first embodiment.

  The seal member 16 is a member that seals the end of the cryogenic temperature side 1LS of the clearance 10c, and is integrally formed with the end of the vacuum heat insulating tube 12 on the cryogenic temperature side 1LS. The seal member 16 may be made of an elastic material such as silicone rubber. By doing so, when the end portion of the vacuum heat insulation tube 12 is inserted into the end portion of the vacuum heat insulation tube 11, the inner peripheral surface of the vacuum heat insulation tube 11 is hardly damaged by the seal member 16. Further, since the seal member 16 has elasticity, the seal member 16 can be in close contact with the inner peripheral surface of the vacuum heat insulating tube 11, and the cryogenic temperature side 1LS of the clearance 10c can be hermetically sealed. In order to ensure airtightness by the seal member 16, the outer shape of the seal member 16 may be the same as or larger than the inner shape of the vacuum heat insulating tube 11.

  The seal member 16 includes a communication hole 16e at the lower end position in the vertical direction. The communication hole 16e functions as a refrigerant inlet that allows the liquid refrigerant 10L to flow from the inside of the insertion type connection structure 1γ toward the clearance 10c.

  On the other hand, the end of the clearance 10c on the non-cryogenic side 1HS is sealed with a closing member 16s. As the closing member 16s, for example, an O-ring or the high-viscosity material described in the first embodiment can be used. When an O-ring is used, an annular groove is formed on the inner peripheral surface of the vacuum heat insulating tube 11 and the O-ring is fitted in the annular groove, and then the end of the vacuum heat insulating tube 12 is fitted to the end of the vacuum heat insulating tube 11. What is necessary is just to insert a part. The O-ring may be pushed in from the non-cryogenic side 1HS of the clearance 10c after connecting both the heat insulating tubes 11 and 12.

  With the insertion-type connection structure 1δ having the above-described configuration, it is possible to suppress an excessive flow of liquid refrigerant into the clearance 10c. In flowing the liquid refrigerant through the refrigerant pipe provided with the insertion type connection structure 1δ, when the refrigerant gas is first blown into the refrigerant pipe, the refrigerant gas flows into the clearance 10c through the communication hole 16e. Next, when the liquid refrigerant is gradually circulated through the refrigerant pipe, the liquid refrigerant flows into the clearance 10c through the communication hole 16e. At this time, the clearance 10c is filled with the refrigerant gas, and the liquid refrigerant in the clearance 10c is vaporized to generate vaporized gas. Since the clearance 10c is sealed by the sealing member 16 and the closing member 16s, the clearance 10c cannot escape out of the clearance 10c, and the pressure in the clearance 10c increases. As a result, the gas in the clearance 10c suppresses the inflow of the liquid refrigerant from the communication hole 16e, the excessive inflow of the liquid refrigerant into the clearance 10c is suppressed, and a gentle temperature gradient is formed in the clearance 10c.

<Embodiment 6>
The partition member described in Embodiments 1 to 4 and the seal member described in Embodiment 5 can be used in combination. In that case, it can be set as the insertion type connection structure which can suppress the increase in the heat penetration through clearance rather than the insertion type connection structure which used the partition member and the sealing member independently.

<Embodiment 7>
In the seventh embodiment, a terminal structure of a superconducting cable including the insertion type connection structure 1ε according to one embodiment of the present invention will be described with reference to FIG. Since the terminal structure of the superconducting cable has already been described with reference to the conventional diagram of FIG. 8, the superconducting cable and the normal conducting lead are not shown in FIG. 7 according to the seventh embodiment.

  The insertion type connection structure 1ε is configured by connecting the vacuum heat insulating tube 11 and the vacuum heat insulating tube 12 via an insulating member 12I. The vacuum heat insulating tube 11, the vacuum heat insulating tube 12, and the insulating member 12I correspond to the cable side heat insulating container 31, the lead side heat insulating container 32, and the insulating member 33 in FIG. That is, the vacuum heat insulating tube 11 is at ground potential, the vacuum heat insulating tube 12 is at high potential, and the two tubes 11 and 12 are insulated by the insulating member 12I.

  In the insertion type connection structure 1ε of this example, the insulating member 12I is integrally formed at the end of the vacuum heat insulating tube 12 that is at a high potential, and therefore, between the vacuum heat insulating tube 11 and the insulating member 12I that is at the ground potential. A clearance 10c is formed. Therefore, the partition member described in Embodiments 1 to 4 and the seal member described in Embodiment 5 are provided in the clearance 10c to suppress an increase in heat penetration through the clearance 10c. Of course, as described in the fifth embodiment, an increase in heat penetration through the clearance 10c may be suppressed by combining the partition member and the seal member, and in that case, an increase in heat penetration through the clearance 10c is suppressed. The effect is the highest. The non-cryogenic side 1HS of the clearance 10c is preferably sealed by forming a metal layer on the outer peripheral surface of the insulating member 12I and welding the metal layer to the vacuum heat insulating tube 11.

  Here, the insulating member 12I may be integrated with the vacuum heat insulating tube 11, and a clearance may be formed between the vacuum heat insulating tube 12 and the insulating member 12I.

  In addition, the application location of the insertion type connection structure of the embodiment in the superconducting cable is not limited to the terminal structure, and may be an intermediate connection structure. Moreover, when connecting two heat insulation containers in a superconducting apparatus such as a superconducting motor, the insertion type connection structure of the embodiment may be applied.

<Eighth embodiment>
In the first to seventh embodiments, the insertion type connection structure in which the insertion axis direction of the vacuum heat insulating tube 11 and the vacuum heat insulating tube 12 is directed in the horizontal direction has been described. On the other hand, even if the insertion type connection structure of Embodiments 1 to 7 is a vertically placed structure in which the heat insulating container (insertion member) 12 is arranged vertically upward, the heat insulation container (insertion member) 12 is vertically downward. A reverse placement structure may be used. In both the vertically placed structure and the reversely placed structure, by providing the partition members 13, 14, 15 and the like in the clearance 10c, it is possible to suppress an increase in heat penetration through the clearance 10c.

  The insertion type connection structure of the present invention can be suitably used for connecting two heat insulating containers in refrigerant piping and superconducting equipment.

1,1α, 1β, 1γ, 1δ, 1ε Insertion type connection structure 1LS Cryogenic side 1HS Non-Cryogenic side 11 Vacuum insulation tube (refrigerant container)
12 Vacuum insulation tube (insertion member)
12I Insulation member 10c Clearance 1LS Cryogenic side 1HS Non-cryogenic side 10L Liquid refrigerant 10G Vaporized gas 13 Hollow long body (partition member) 13s Closure member 14 Corrugated plate member (partition member)
13e, 14e Refrigerant inlet 13i, 14i Kushiro 15 Solid long body (partition member)
15e refrigerant inlet 15i bottleneck 16 seal member 16e communication hole (refrigerant inlet) 16s closing member 100 terminal structure 2 normal conducting lead 3 heat insulation structure (insertion type connection structure)
31 Cable side heat insulation container 32 Lead side heat insulation container 33 Insulation member 4 Cable core 41 Superconducting conductor layer 42 Cable insulation layer 43 Cable shielding layer 5 Cable insulation tube SC Superconducting cable

Claims (11)

A refrigerant container in which a cryogenic liquid refrigerant is disposed is connected to an insertion member partially inserted into the open end of the refrigerant container, and the refrigerant container and the insertion member are Of the clearances formed in the overlapping portion in the insertion axis direction, the insertion type connection structure in which the side where the refrigerant container is arranged in the insertion axis direction is extremely low temperature and the side where the insertion member is arranged is non-cryogenic Because
An insertion type connection structure comprising an inlet forming member provided at a position in contact with the liquid refrigerant on the cryogenic temperature side in the clearance and forming a refrigerant inlet at a part of the clearance in the circumferential direction. The inflow port forming member is a partition member that forms a narrow channel extending from the cryogenic temperature side toward the non-cryogenic temperature side by partitioning the clearance in a circumferential direction, and an end portion of the narrow channel on the cryogenic temperature side The refrigerant inlet is formed by
The insertion type connection structure according to claim 1, wherein an end of the non-cryogenic side in the bottleneck is closed.   The insertion type connection structure according to claim 2, wherein the partition member is a hollow long body.   The insertion type connection structure according to claim 2, wherein the partition member is a corrugated plate member. The inlet forming member is a partition member that spirally extends from the cryogenic temperature side to the non-cryogenic temperature side so as to spirally extend from the cryogenic temperature side to the non-cryogenic temperature side. The refrigerant inlet is formed by the end on the side,
The insertion type connection structure according to claim 1, wherein an end of the non-cryogenic side in the bottleneck is closed.   The insertion type connection structure according to any one of claims 2 to 5, further comprising a closing member that closes an end portion of the non-low temperature side of the bottleneck.   The insertion type connection structure according to claim 6, wherein the closing member is made of a high-viscosity material that is injected into a position of the end portion on the non-cryogenic side in the bottleneck. The insertion axis direction is inclined from the vertical direction;
The inflow port forming member configured by a seal member that seals an end portion of the clearance on the cryogenic side,
The insertion type connection structure according to any one of claims 1 to 7, wherein the seal member includes a communication hole serving as the refrigerant inlet at a position of a lower end in a vertical direction. A refrigerant pipe constructed by connecting a plurality of tubular heat insulating containers,
The refrigerant | coolant piping which used the insertion type connection structure of Claim 1 for the connection structure of the two said heat insulation containers connected. A superconducting device comprising a superconducting member and a vacuum heat insulating structure covering the outer periphery of the superconducting member,
A superconducting device using the insertion type connection structure according to claim 1 as a part of the vacuum heat insulating structure.   The superconducting device according to claim 10, wherein the superconducting member is a cable core of a superconducting cable.

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