JP5422843B2 - Connection joint for piping for cryogenic fluid - Google Patents

Description

  The present invention relates to a connection joint for piping for cryogenic fluid, and more particularly to a connection joint used for liquid hydrogen supply piping.

  A pipe that uses a bayonet joint has been proposed to connect pipes in which the inner pipe of a double pipe with a heat insulation layer formed between the outer pipe and the inner pipe is used as a cryogenic fluid flow passage. Yes. However, in the case of the prior art, when the joint is separated, the flow path of the cryogenic fluid in the inner pipe is exposed to the outside air. The atmosphere is mixed in. Further, when the joint is separated while the joint and the inner pipe are cooled by the cryogenic fluid, condensation and frost formation occur in the joint and the inner pipe. For this reason, there is a problem that a gas purge or a heating operation is required every connection operation.

  Therefore, in order to suppress dew condensation and frost formation at the joint part, the connecting part between the inner pipes is set at a position different from the connecting part of the outer pipe, and a shutter for shutting off the outside air is connected to the connecting part between the outer pipes. The thing which has arrange | positioned the provided sheath tube is proposed. (Patent Document 1)

Japanese Patent Publication No. 07-018519

  However, in the above-described prior art, both the supply-side joint portion and the equipment-side joint portion to be connected are located at locations where they enter from the opening (shutter position) of the sheath tube. As a result, when connecting a pipe constructed of a double pipe, at least one outer pipe and the sheath pipe must be relatively slid to advance one joint part to the other joint part. . For this reason, the airtightness between one outer tube and the sheath tube is broken, and the gas that flows out when the inner tubes are connected or disconnected may leak from between the sheath tube and the outer tube. If the leaking gas is an inert gas such as liquid nitrogen, only economic loss is sufficient, but in the case of a flammable gas such as liquid hydrogen, the problem of gas leakage can cause an explosion. There is.

  The present invention has been proposed in view of such points, and can be easily connected before and after the transfer operation of the cryogenic liquefied gas without performing the gas purging or the heating operation. An object of the present invention is to provide a connection joint for a cryogenic fluid pipe capable of suppressing leakage into the pipe.

In order to achieve the above-mentioned object, the present invention as set forth in claim 1 comprises a cryogenic fluid supply pipe comprising an inner pipe through which a cryogenic fluid flows and an outer pipe covering the outside of the inner pipe. A connection joint of a cryogenic fluid pipe configured to connect and separate a pair of cryogenic fluid supply pipes,
An open / close mechanism is arranged at the connection end of the outer pipe of the liquid receiving side connection joint communicating with the container side pipe connected to the liquid receiving container side,
The connection end of the inner pipe of the liquid-receiving side connection joint is enlarged from the middle, and this enlarged diameter part is positioned at a position retracted from the connection end of the outer pipe, and the supply described later is supplied to the enlarged diameter part of the inner pipe. Locate the valve opening operation part of the self-sealing shut-off valve attached to the side connection joint,
The tip side of the supply side connection joint that communicates with the supply source side pipe connected to the cryogenic fluid supply source is inserted into the inner pipe of the liquid reception side connection joint through the open / close mechanism in the valve open state. A self-sealing type shut-off valve that is elastically biased toward the valve closing side is positioned at the tip of the supply side connection joint,
The outer periphery of the insertion part of the supply side connection joint that is inserted into the liquid receiving side connection joint is covered with an outer tube configured to be extendable, and the inner peripheral surface of the connector mounted on the distal end portion of this outer tube and the supply side The outer peripheral surface of the connection joint is configured to be relatively slidable through an airtight seal, and the outer peripheral surface near the tip of the connector is airtightly fitted to the opening formed in the box portion of the open / close mechanism of the liquid receiving side connection joint Configure as possible
Leakage that flows between the supply-side connection joint and the outer tube by arranging a relief valve on the gas return tube between the base end of the outer tube and the connection part of the supply-source side pipe. It is characterized in that the gas is returned into the inner pipe of the supply side connection joint.

According to the second aspect of the present invention, a cryogenic fluid supply pipe is constituted by an inner tube through which a cryogenic fluid flows and an outer tube covering the outside of the inner tube, and a pair of cryogenic fluids are provided. A connection joint for cryogenic fluid pipes that can be connected and disconnected from the supply pipe,
An open / close mechanism is arranged at the connection end of the outer pipe of the supply side connection joint communicating with the supply side pipe connected to the cryogenic fluid supply source,
The connection end of the inner pipe of the supply side connection joint is enlarged from the middle, and the enlarged diameter part is positioned at a position retracted from the connection end of the outer pipe. Locate the valve opening operation part of the self-sealing shut-off valve attached to the side connection joint,
The tip side of the container-side connection joint communicating with the container-side pipe connected to the liquid-receiving container side can be inserted into the inner pipe of the supply-side connection joint through the valve opening and closing mechanism. Then, the self-sealing shutoff valve) is positioned in a state of being elastically biased toward the valve closing side at the tip of the liquid receiving side connection joint,
The outer periphery of the insertion part of the liquid-receiving-side connection joint that is inserted into the supply-side connection joint is covered with an outer tube that can be expanded and contracted, and the inner peripheral surface of the connector mounted on the distal end portion of this outer tube and the supply side The outer peripheral surface of the connection joint can be slid relative to the outer periphery of the connector through an airtight seal, and the outer peripheral surface near the tip of the connector can be hermetically fitted into the opening formed in the box of the opening and closing mechanism of the supply-side connection joint To configure
A gas return pipe is connected between the base end of the outer tube and the connection part of the vessel side pipe, and a leak valve is disposed on the gas return pipe to leak between the liquid-receiving side connection joint and the outer tube. It is characterized in that the gas is returned into the inner pipe of the liquid-receiving side connection joint.

  In the present invention, the supply connected to the supply end pipe connected to the connection end portion of the outer pipe of the liquid receiving side connection joint connected to the container side pipe connected to the liquid receiving container side or the cryogenic fluid supply source An open / close mechanism is arranged at the connection end of the outer connection joint at the outer pipe, and the connection end of the inner pipe of the liquid-receiving connection joint or the connection end of the inner pipe of the supply connection joint is connected to the connection end of the outer pipe. Therefore, when the pair of cryogenic fluid supply pipes are not connected, operating the open / close mechanism to the closed state prevents contact with the outside air inside the inner pipe and the connection end. Thus, frost formation and dew condensation at the connection end of the inner pipe can be prevented, and connection work can be easily performed without performing gas purging or heating work at the next connection operation.

  Further, in the present invention, the outer periphery of the insertion portion of the supply side connection joint that is inserted into the liquid reception side connection joint or the outer periphery of the insertion portion of the liquid reception side connection joint that is inserted into the supply side connection joint can be expanded and contracted. The outer peripheral surface of the coupling member attached to the distal end portion of the outer tube and the outer peripheral surface of the supply side connection joint or the liquid reception side connection joint can be slid relative to each other via an airtight seal. In addition, the outer peripheral surface near the distal end of the coupler is configured to be airtightly fitted into an opening formed in the box portion of the opening and closing mechanism of the liquid receiving side connection joint or the supply side connection joint, and the base end of the outer tube A gas return pipe is connected between the connection with the supply source side pipe, and a relief valve is arranged on the gas return pipe, and the leakage gas flowing through the pipe between the supply side connection joint or the liquid reception side connection joint and the mantle pipe To return to the inner pipe of the supply side connection joint or liquid reception side connection joint Therefore, even if cryogenic fluid leaks from the connection part during connection operation or during connection, the leaked gas is sent between the outer tube and the outer tube through the gas return tube. Since it is returned to the inner pipe of the liquid side cryogenic fluid supply pipe or the liquid receiving side cryogenic fluid supply pipe, the leaked gas is not released to the outside.

It is the schematic sectional drawing which omitted a part showing one embodiment of the connection joint concerning the present invention. It is a longitudinal cross-sectional view of the liquid receiving side connection coupling which shows one Embodiment of the connection coupling which concerns on this invention. It is a longitudinal cross-sectional view of the liquid feeding side connection coupling which shows one Embodiment of the connection coupling which concerns on this invention. FIG. 4 is an enlarged vertical sectional view of a part IV in FIG. 1. It is a longitudinal cross-sectional view which shows another embodiment of a liquid receiving side connection coupling. FIG. 2 is a view corresponding to FIG. 1 showing an embodiment of a connection joint according to the present invention.

  The connection joint (C) shown in FIG. 1 is connected to the tip of the container-side pipe (1) connected from a cryogenic fluid receiver such as a fuel hydrogen tank (not shown). Side connection joint (2) and a supply side connection joint (4) connected in communication with the tip of a supply side pipe (3) led out from a cryogenic fluid storage container such as a liquid hydrogen storage container (not shown) ) And.

  The liquid-receiving side connection joint (2) and the supply-side connection joint (4) include an inner pipe (5) through which a cryogenic fluid such as liquid hydrogen flows and an outer pipe covering the outside of the inner pipe (5). (6), and the space (7) between the inner pipe (5) and the outer pipe (6) is constituted by a cryogenic fluid supply pipe having a double-pipe structure with vacuum insulation.

  As shown in FIG. 2, the liquid-receiving side connection joint (2) has a ball valve (opening / closing mechanism) (8) attached to the connection side end of the outer pipe (6). Further, the diameter of the connection end of the inner pipe (5) is increased from the middle, and the diameter-expanded part is positioned at a position retracted from the connection side end of the outer pipe (6). A valve opening operation portion (11) for opening a self-sealing shutoff valve (10) mounted on a supply side connection joint (4) described later is positioned on the diameter portion (9).

  As shown in FIGS. 3 and 4, the supply side connection joint (4) urges the valve element (12) at the tip of the inner pipe (5) in the closing direction by the valve closing spring (13). A self-sealing shut-off valve (10) is mounted, and an outer tube (15) in which an outer periphery of an insertion tube portion (14) composed of an inner tube (5) and an outer tube (6) is constituted by an expansion tube such as a bellows. It is covered with. The outer tube (15) has its base end fixed to the outer tube (6) of the supply side connection joint (4) with a fixing rod (16) and assembled so as to be airtightly slidable with respect to the outer tube (6). The connected connector (17) is attached to the tip portion.

  Further, the base end side of the supply side connection joint (4) is formed in a cup shape for receiving the leading end portion (3a) of the supply side pipe (3), and the base end portion of the supply side connection joint (4) A gas return pipe between the connecting flange (18) provided on the pipe and a fixing rod (16) for fixing the base end portion of the outer tube (14) to the outer pipe (6) of the supply side connection joint (4) (20) is connected to a pipe, and a relief valve (21) is arranged in the middle of the gas return pipe (20).

  The gas return pipe (20) has a space located between the outer pipe (6) and the outer pipe (15) of the supply side connection joint (4) in the portion corresponding to the inner pipe at the connecting flange (18). It is comprised so that it may communicate with the inside.

  When connecting using the supply side connection joint (4) and the liquid reception side connection joint (2) having the above-described configuration, the connection side end of the outer pipe (6) of the liquid reception side connection joint (2) is used. With the ball valve (8) provided open, the supply side connection joint (4) passes through the opening (22) of the ball valve (8) through the insertion pipe portion (14) of the supply side connection joint (4). The self-sealing type shut-off valve (10) mounted at the tip of the inner pipe (5) of the supply side connection joint (4) is inserted into the inner pipe (5) of the liquid supply side connection joint (2). The valve of the self-sealing type shut-off valve (10) is brought into contact with the valve opening operation part (11) mounted on the enlarged diameter part (9) of the inner pipe (5). By pushing the child (12) against the valve closing biasing spring (13), the inner pipes (5) of the supply side connection joint (4) and the liquid receiving side connection joint (2) are connected in communication.

  At the time of this connection operation, the outer tube (15) fitted on the outer periphery of the outer tube (6) of the insertion tube portion (14) of the supply side connection joint (4) is, as shown in FIG. Insertion pipe that is inserted and moved by the connector (17) attached to the pipe is received by the box part (23) of the ball valve (8) attached to the open end of the outer pipe of the liquid receiving side connection joint (2) It will slide relative to the part (14). In addition, the code | symbol (24) in FIG. 4 is the sealing material arrange | positioned between a connector (17) and a box part (23), and a code | symbol (25) is a connector (17) and an insertion pipe part (14). It is the sealing material arrange | positioned between the outer periphery of this outer pipe | tube (6).

  Then, during this connection work, the valve body (12) of the self-sealing shutoff valve (10) starts to open until the connection joints (2) and (4) are completely connected, or the pole During the transfer of the cryogenic fluid, or between the start of the separation of the connecting joints (2) and (4) and until the valve body (12) of the self-sealing shutoff valve (10) is completely closed The leaked cryogenic fluid is separated from the outer peripheral surface of the outer pipe (6) of the insertion pipe portion (14) of the supply side connection joint (4) and the inner peripheral surface of the inner pipe (5) of the liquid receiving side connection joint (2). Between the outer tube (15) and the outer peripheral surface of the outer tube (6) of the insertion tube portion (14). 6) Since the space formed between the outer peripheral surface of the outer tube and the inner peripheral surface of the outer tube (15) communicates with the gas return tube (20), it is connected to the supply side via the gas return tube (20). It will be returned to the inner pipe (5) of the joint (4). At this time, the cryogenic fluid flowing in the space formed between the outer peripheral surface of the outer tube of the insertion tube portion (14) and the inner peripheral surface of the outer tube (15) is caused by heat input from the outside in the flow. The pressure is increased by gasification, and the pressure is returned to the inner pipe (5) at a pressure higher than the relief set pressure (for example, 0.6 MPa) by the action of the relief valve (21) mounted on the gas return pipe (20). .

  FIG. 5 shows a modified embodiment of the liquid-receiving side connection joint (2), which is a valve opening mounted on the diameter-enlarged portion (9) of the inner pipe (5) of the liquid-receiving side connection joint (2). The operation part (11) is composed of a self-sealing valve body (26) elastically biased toward the valve closing side, and the tip of the valve body (26) is connected to the supply side connection joint (4). The valve element (12) and the valve opening operation part (11) of the self-sealing type shut-off valve (10) are brought into contact with the self-sealing type shut-off valve (10) mounted at the tip of the inner pipe (5). The valve body (26) is opened so that the inner pipe (5) of the supply side connecting joint (4) and the inner pipe (5) of the liquid receiving side connecting joint (2) are connected in communication.

  FIG. 6 is a view corresponding to FIG. 1 showing another embodiment of the present invention. In this embodiment, a ball valve (8) is attached to the connection side end of the outer pipe (6) of the supply side connection joint (4), and the diameter of the connection end of the inner pipe (5) is increased from the middle. The diameter-expanded portion is positioned at a position retracted from the connection-side end of the outer pipe (6), and is attached to the liquid-receiving-side connection joint (2) described later on the diameter-expanded section (9) of the inner pipe (5). The valve-opening operation part (11) for opening the self-sealing shut-off valve (10) is positioned, and the liquid-receiving side connection joint (2) is connected to the valve element (12 at the tip of the inner pipe (5). ) Is mounted with a self-sealing shut-off valve (10) urged in the closing direction by a valve-urging spring (13), and an insertion tube portion (inner tube (5) and outer tube (6)) The outer periphery of 14) is covered with an outer tube (15) made of an expansion tube such as a bellows.

In this embodiment, the base end portion of the outer tube (15) is fixed to the outer tube (6) of the liquid-receiving-side connection joint (4) with the fixing rod (16) and is airtight with respect to the outer tube (6). Attach a slidably assembled connector (17) to the distal end of the connector, and connect the flange (18) to the proximal end of the receiver connection joint (4) and the proximal end of the outer tube (14) A gas return pipe (20) is connected to the fixed rod (16) that fixes the pipe to the outer pipe (6) of the supply side connection joint (4), and a relief valve ( 21) is arranged.
Other configurations are the same as those in the above-described embodiment.

  INDUSTRIAL APPLICABILITY The present invention can be used as a connection joint in a cryogenic fluid transfer path in a liquid hydrogen supply facility such as a hydrogen vehicle, a fuel cell vehicle, or an industrial application.

  DESCRIPTION OF SYMBOLS 1 ... Container side piping, 2 ... Liquid receiving side connection joint, 3 ... Supply source side piping, 4 ... Supply side connection coupling, 5 ... Inner pipe, 6 ... Outer pipe, 8 ... Opening / closing mechanism, 9 ... Expanding part, 10 DESCRIPTION OF SYMBOLS: Self-sealing type shut-off valve, 11 ... Valve opening operation part, 14 ... Insertion part, 15 ... Outer tube, 17 ... Connector, 20 ... Gas return pipe, 21 ... Relief valve, 23 ... Box part of opening / closing mechanism, 25 ... Airtight seal, 26 ... Self-sealing shut-off valve.

Claims (5)

The inner pipe (5) through which the cryogenic fluid flows and the outer pipe (6) covering the outside of the inner pipe (5) constitute a cryogenic fluid fluid supply pipe, and a pair of cryogenic fluid supply pipes Is a connection joint of piping for cryogenic fluid that can be connected and separated,
An opening / closing mechanism (8) is arranged at the connection end of the outer pipe (6) of the liquid receiving side connection joint (2) communicating with the container side pipe (1) connected to the liquid receiving container side,
The diameter of the connection end of the inner pipe (5) of the liquid-receiving side connection joint (2) is increased from the middle, and this diameter expansion part (9) is positioned at a position retracted from the connection end of the outer pipe (6). The valve opening operation part (11) of the self-sealing shutoff valve (10) attached to the supply side connection joint (4) described later is positioned on the enlarged diameter part (9) of the inner pipe (5),
The tip side of the supply side connection joint (4) communicating with the supply source side pipe (3) connected to the cryogenic fluid supply source passes through the open / close mechanism (8) in the open state to receive liquid. It is constructed so that it can be inserted into the inner pipe (5) of the connection joint (2), and the self-sealing shutoff valve (10) is elastically biased toward the valve closing side at the tip of this supply side connection joint (4) Positioned in a state,
The outer periphery of the insertion portion (14) of the supply side connection joint (4) to be inserted into the liquid receiving side connection joint (2) is covered with an extendable outer tube (15), and this outer tube (15) The inner peripheral surface of the connector (17) attached to the distal end of the connector and the outer peripheral surface of the supply side connection joint are configured to be slidable relative to each other via an airtight seal (25), and closer to the tip of the connector (17). The outer peripheral surface of the part is configured to be airtightly fitted into an opening formed in the box part (23) of the opening / closing mechanism (8) of the liquid-receiving side connection joint (2),
A gas return pipe (20) is piped between the base end of the mantle pipe (15) and the connection part of the supply source side pipe (3), and a relief valve (21) is arranged in the gas return pipe (20). The leakage gas flowing between the supply side connection joint (4) and the outer tube (15) is returned to the inner pipe (5) of the supply side connection joint (4). Connection joint for piping for cryogenic fluid. The inner pipe (5) through which the cryogenic fluid flows and the outer pipe (6) covering the outside of the inner pipe (5) constitute a cryogenic fluid fluid supply pipe, and a pair of cryogenic fluid supply pipes Is a connection joint of piping for cryogenic fluid that can be connected and separated,
An open / close mechanism (8) is arranged at the connection end of the outer pipe (6) of the supply side connection joint (4) communicating with the supply side pipe (3) connected to the cryogenic fluid supply source,
The diameter of the connecting end of the inner pipe (5) of the supply side connecting joint (4) is increased from the middle, and this enlarged diameter part (9) is positioned at a position retracted from the connecting end of the outer pipe (6). Position the valve opening operation part (11) of the self-sealing shut-off valve (10) attached to the liquid receiving side connection joint (2) described later on the enlarged diameter part (9) of the inner pipe (5),
A portion near the tip of the container-side connection joint (2) communicating with the container-side pipe (1) connected to the liquid-receiving container side passes through the open / close mechanism (8) in the open state to supply-side connection joint ( 4) It is constructed so that it can be inserted into the inner pipe (5), and the self-sealing shut-off valve (10) is elastically biased toward the valve closing side at the tip of the liquid receiving side connection joint (2). Position
The outer periphery of the insertion portion (14) of the liquid-receiving-side connection joint (2) to be inserted into the supply-side connection joint (4) is covered with an outer tube (15) configured to be extendable, and this outer tube (15) The inner peripheral surface of the connector (17) attached to the distal end of the connector and the outer peripheral surface of the supply side connection joint are configured to be slidable relative to each other via an airtight seal (25), and closer to the tip of the connector (17). The outer peripheral surface of the part is configured to be airtightly fitted into an opening formed in the box part (23) of the opening / closing mechanism (8) of the supply side connection joint (2),
A gas return pipe (20) is piped between the base end of the outer tube (15) and the connection part of the container side pipe (3), and a relief valve (21) is arranged in the gas return pipe (20). The leakage gas flowing between the liquid-receiving side connection joint (2) and the outer tube (15) is returned to the inner pipe (5) of the liquid-receiving side connection joint (2). Connection joint for cryogenic fluid piping.   Connection joint of piping for cryogenic fluid according to claim 1 or 2, wherein the outer tube (15) configured to be expandable / contracted is configured by a bellows.   A protrusion that pushes the valve element (12) of the self-sealing shut-off valve (10) is attached to the enlarged diameter part (9), and the valve opening operation part (11) of the self-sealing shut-off valve (10) is attached by this protrusion. The connection joint of piping for cryogenic fluids described in any one of claims 1 to 3.   The self-sealing shut-off valve (26) is attached to the enlarged diameter portion (9), and the valve-opening operation portion (11) is constituted by the self-sealing shut-off valve (26). Connection joint for piping for cryogenic fluid as described in the section.

Images