WO2024127451A1

WO2024127451A1 - Piping equipment and piping equipment control method

Info

Publication number: WO2024127451A1
Application number: PCT/JP2022/045633
Authority: WO
Inventors: 宏之武田; 貴志下垣; 晴彦冨永; 麻子三橋; 翔樋渡; まり子 ▲高▼須賀
Original assignee: 川崎重工業株式会社
Priority date: 2022-12-12
Filing date: 2022-12-12
Publication date: 2024-06-20

Abstract

Piping equipment according to one aspect of the present disclosure is for connecting a liquefied gas tank for storing liquefied gas and related equipment, and comprises: a first pipe that has a first extending/retracting joint which can extend/retract in response to external force and that conveys, from the liquefied gas tank to the related equipment or from the related equipment to the liquefied gas tank, low-temperature fluid which is the liquefied gas or vaporized gas generated by vaporization of the liquefied gas; and a second pipe that has a second extending/retracting joint which can extend/retract in response to external force, that is disposed in parallel to the first pipe, and that conveys the same low-temperature fluid in the same direction as the first pipe.

Description

Piping equipment and method for controlling piping equipment

This disclosure relates to piping equipment and a method for controlling piping equipment.

Patent Document 1 discloses a tank for storing liquefied hydrogen and hydrogen piping connected to the tank for transporting the liquefied hydrogen.

JP 2022-103902 A

Liquefied gas tanks that store low-temperature liquefied gas such as liquefied hydrogen expand or contract depending on the amount of liquefied gas stored and the outside temperature. As the liquefied gas tank expands and contracts, it displaces relative to other equipment other than the liquefied gas tank. For this reason, the piping equipment connecting the liquefied gas tank to related equipment is equipped with an expansion joint that can expand and contract to absorb this displacement. However, the expansion joint is thinner than other parts of the piping equipment and is therefore susceptible to damage. If the expansion joint is damaged, the transport of liquefied gas must be stopped until the expansion joint is repaired. Note that the piping equipment connecting the liquefied gas tank to related equipment may transport not only liquefied gas, but also vaporized gas that is the result of vaporization of liquefied gas. In the following, the above liquefied gas and liquefied gas will be collectively referred to as "low-temperature fluid".

In light of these circumstances, the present disclosure aims to provide a piping system that connects a liquefied gas tank to related equipment and that can continue to transport cryogenic fluid even if an expansion joint is damaged.

The piping equipment according to one embodiment of the present disclosure is a piping equipment that connects a liquefied gas tank that stores liquefied gas to related equipment, and includes a first pipe having a first expansion joint that can expand and contract in response to an external force, and transporting a cryogenic fluid, which is liquefied gas or a vaporized gas obtained by vaporizing liquefied gas, from the liquefied gas tank to the related equipment or from the related equipment to the liquefied gas tank, and a second pipe having a second expansion joint that can expand and contract in response to an external force, positioned in parallel to the first pipe, and transporting the same cryogenic fluid in the same direction as the first pipe.

With this configuration, even if the first expansion joint or the second expansion joint is damaged, the transport of the low-temperature fluid can continue.

FIG. 1 is a schematic side view of a piping installation. FIG. 2 is a schematic plan view of the piping installation. FIG. 3 is a block diagram of the electrical system of the piping fixture. FIG. 4 is a flow diagram of the monitoring program.

(Outline of piping equipment)
Hereinafter, an embodiment will be described. Fig. 1 is a schematic side view of a piping equipment 100 according to an embodiment. As shown in Fig. 1, the piping equipment 100 according to the embodiment is equipment that connects a liquefied gas tank 101 and related equipment 102.

The liquefied gas tank 101 is a tank that stores liquefied gas. The liquefied gas stored in the liquefied gas tank 101 is, for example, liquefied hydrogen, but is not limited thereto. The liquefied gas tank 101 of this embodiment is mounted on a liquefied gas carrier 103. However, the liquefied gas tank 101 does not have to be mounted on the liquefied gas carrier 103, and may be installed on the ground, for example. The upper portion of the liquefied gas tank 101 of this embodiment is located above the upper deck 104 of the liquefied gas carrier 103. The liquefied gas tank 101 has a dome 105 at the top, and the piping equipment 100 is connected to this dome 105.

The related equipment 102 is equipment that exchanges low-temperature fluid with the liquefied gas tank 101. In this embodiment, the related equipment 102 is a manifold with a collection of connection ports that connect to equipment such as ground equipment. However, the related equipment 102 is not limited to a manifold, and may be, for example, an engine that uses liquefied gas as fuel, or equipment for re-liquefying vaporized gas that has evaporated from liquefied gas. The related equipment 102 in this embodiment is installed on the upper deck 104 of the liquefied gas carrier 103, but may also be installed inside the liquefied gas carrier 103 or on land.

The liquefied gas tank 101 expands or contracts depending on the amount of liquefied gas stored therein, the outside air temperature, etc. As a result, the liquefied gas tank 101 displaces relative to the associated equipment 102. For example, the dome 105 in this embodiment displaces up and down relative to the associated equipment 102. Therefore, the piping equipment 100 is provided with

piping

10, 20 having

expandable expansion joints

11, 21 to absorb this displacement. Details of the piping equipment 100 will be described later.

(Overall structure of piping equipment)
Next, the overall structure of the piping equipment 100 according to this embodiment will be described. Fig. 2 is a schematic plan view of the piping equipment 100. The piping equipment 100 includes a first pipe 10, a second pipe 20, a tank-side common pipe 30, a related equipment-side common pipe 40, and a drip tray 50 (see Fig. 1). These components and components related to these components will be described in order below.

<First piping>
The first pipe 10 has a first expansion joint 11 and is a pipe for transporting a cryogenic fluid from the liquefied gas tank 101 to the related equipment 102 or from the related equipment 102 to the liquefied gas tank 101. The first expansion joint 11 is expandable and contractible in response to an external force, and is, for example, a bellows or a flexible hose. The first pipe 10 of this embodiment is a double pipe and includes a first inner pipe 12 and a first outer pipe 13 covering the first inner pipe 12. The cryogenic fluid passes through the first inner pipe 12, and a vacuum is maintained between the first inner pipe 12 and the first outer pipe 13, that is, a state in which the air pressure is lower than the external air pressure. By making the first pipe 10 a double pipe, it is possible to suppress a temperature change of the cryogenic fluid passing through the first inner pipe 12 and to suppress a decrease in the surface temperature of the first pipe 10.

In addition, since the first piping 10 is a double pipe, the first expansion joint 11 is also formed double correspondingly. Specifically, the first expansion joint 11 includes an expandable first inner joint 14 located in the first inner pipe 12, and an expandable first outer joint 15 located in the first outer pipe 13 and covering the first inner joint 14. Of these, the first inner joint 14 is not visible from the outside of the first piping 10, so damage to the first inner joint 14 cannot be confirmed visually.

A pair of first shutoff valves 16 are located upstream and downstream of the first inner fitting 14 of the first inner pipe 12. Hereinafter, the section located between the pair of first shutoff valves 16 of the first inner pipe 12 is referred to as the "first shutoff section 17." By closing the pair of first shutoff valves 16, the first shutoff section 17 in which the first inner fitting 14 is located can be fluidically shut off.

The first pipe 10 is provided with a first thermometer 60. The first thermometer 60 measures the first gap temperature, which is the temperature between the first inner pipe 12 and the first outer pipe 13. If the first inner pipe 12 is damaged and the cryogenic fluid leaks from the first inner pipe 12, the air between the first inner pipe 12 and the first outer pipe 13 is cooled by the cryogenic fluid, and the first gap temperature drops. In other words, by monitoring the first gap temperature, it is possible to determine whether or not the cryogenic fluid has leaked from the first inner pipe 12.

A first gas supply pipe 61 is connected to the first isolation section 17 of the first inner pipe 12. The first gas supply pipe 61 can supply inert gas to the first isolation section 17. In this embodiment, the first gas supply pipe 61 is always connected to an inert gas tank that stores inert gas. However, the first gas supply pipe 61 may be connected to the inert gas tank depending on the situation.

A first gas supply valve 62 is located in the first gas supply pipe 61. By opening the first gas supply valve 62, inert gas can be supplied to the first isolation section 17. On the other hand, by closing the first gas supply valve 62, the supply of inert gas to the first isolation section 17 can be stopped.

A first gas exhaust pipe 63 is further connected to the first isolation section 17 of the first inner pipe 12. The first gas exhaust pipe 63 can exhaust gas (vaporized gas and inert gas) within the first isolation section 17. In this embodiment, the first gas exhaust pipe 63 is constantly connected to a treatment facility such as a vent mast that processes (including exhausting) gas. However, the first gas exhaust pipe 63 may be connected to a treatment facility depending on the situation.

A first gas exhaust valve 64 is located in the first gas exhaust pipe 63. By opening the first gas exhaust valve 64, gas can be exhausted from the first cut-off section 17. On the other hand, by closing the first gas exhaust valve 64, the exhaust of gas from the first cut-off section 17 can be stopped.

A first safety pipe 65 is further connected to the first cut-off section 17 of the first inner pipe 12. The first safety pipe 65 can exhaust gas (vaporized gas and inert gas) within the first cut-off section 17. The first gas exhaust pipe 63 is constantly connected to a treatment facility such as a vent mast that processes (including exhausting) the gas.

A first safety valve 66 is located in the first safety pipe 65. The first safety valve 66 is configured to open when a pressure equal to or greater than a predetermined pressure is applied. As a result, if the internal pressure of the first cutoff section 17 rises too much, the first safety valve 66 opens and the internal pressure of the first cutoff section 17 decreases. As a result, damage to the first inner pipe 12 can be prevented.

<Second piping>
The second pipe 20 is located in parallel to the first pipe 10 and transports the same cryogenic fluid in the same direction as the first pipe 10. For example, when the first pipe 10 transports liquefied gas from the liquefied gas tank 101 to the related equipment 102, the second pipe 20 also transports liquefied gas from the liquefied gas tank 101 to the related equipment 102. For example, when the first pipe 10 transports vaporized gas from the cryogenic fluid from the related equipment 102 to the liquefied gas tank 101, the second pipe 20 also transports vaporized gas from the related equipment 102 to the liquefied gas tank 101. As shown in FIG. 2, the first pipe 10 and the second pipe 20 are located symmetrically with respect to a reference plane 99 and have shapes symmetrical with respect to the reference plane. Note that the reference plane 99 in this embodiment is a vertical plane passing through the center of the liquefied gas tank 101. By configuring the first pipe 10 and the second pipe 20 in this manner, the pipe resistances of the first pipe 10 and the second pipe 20 can be made approximately the same.

The second pipe 20 is basically configured in the same way as the first pipe 10. The second expansion joint 21, second inner pipe 22, second outer pipe 23, second inner joint 24, second outer joint 25, second shutoff valve 26, and second shutoff section 27 of the second pipe 20 shown in FIG. 2 correspond to the first expansion joint 11, first inner pipe 12, first outer pipe 13, first inner joint 14, first outer joint 15, first shutoff valve 16, and first shutoff section 17 of the first pipe 10, respectively, and therefore will not be described here.

Similarly, the second thermometer 70, second gas supply pipe 71, second gas supply valve 72, second gas exhaust pipe 73, second gas exhaust valve 74, second safety pipe 75, and second safety valve 76 around the second pipe 20 correspond to the first thermometer 60, first gas supply pipe 61, first gas supply valve 62, first gas exhaust pipe 63, first gas exhaust valve 64, first safety pipe 65, and first safety valve 66 around the first pipe 10, respectively, and therefore will not be described here. The second thermometer 70 measures the second gap temperature, which is the temperature between the second inner pipe 22 and the second outer pipe 23.

<Tank side common piping>
The tank side common pipe 30 is a pipe located between the first pipe 10 and the second pipe 20 and the liquefied gas tank 101. One end of the tank side common pipe 30 is connected to the liquefied gas tank 101. The other end of the tank side common pipe 30 is connected to both the end of the first pipe 10 on the liquefied gas tank 101 side and the end of the second pipe 20 on the liquefied gas tank 101 side.

More specifically, the tank side common piping 30 of this embodiment includes a tank side inner pipe 31 and a tank side outer pipe 32 that covers the tank side inner pipe 31. Of these, the tank side inner pipe 31 has one end connected to the liquefied gas tank 101 and the other end connected to both the first inner pipe 12 and the second inner pipe 22. In addition, the tank side outer pipe 32 has one end connected to the liquefied gas tank 101 and the other end connected to both the first outer pipe 13 and the second outer pipe 23.

In this way, the first pipe 10 and the second pipe 20 are connected to the liquefied gas tank 101 via the tank side common pipe 30. Therefore, the piping equipment 100 according to this embodiment can reduce the area occupied near the liquefied gas tank 101. However, the first pipe 10 and the second pipe 20 may each be directly connected to the liquefied gas tank 101 without going through the tank side common pipe 30.

<Common piping for related equipment>
The related equipment side common pipe 40 is a pipe located between the first pipe 10 and the second pipe 20 and the related equipment 102. One end of the related equipment side common pipe 40 is connected to both the end of the first pipe 10 on the related equipment 102 side and the end of the second pipe 20 on the related equipment 102 side. The other end of the related equipment side common pipe 40 is connected to the related equipment 102.

More specifically, the related equipment side common piping 40 in this embodiment includes a related equipment side inner pipe 41 and a related equipment side outer pipe 42 that covers the related equipment side inner pipe 41. Of these, the related equipment side inner pipe 41 has one end connected to both the first inner pipe 12 and the second inner pipe 22, and the other end connected to the related equipment 102. In addition, the related equipment side outer pipe 42 has one end connected to both the first outer pipe 13 and the second outer pipe 23, and the other end connected to the related equipment 102.

In this way, the first pipe 10 and the second pipe 20 are connected to the related equipment 102 via the related equipment side common pipe 40. Therefore, the piping equipment 100 according to this embodiment can reduce the area occupied near the related equipment 102. However, the first pipe 10 and the second pipe 20 may each be directly connected to the related equipment 102 without going through the related equipment side common pipe 40.

<Drip tray>
As shown in Fig. 1, the drip tray 50 is located vertically below the first expansion joint 11 and the second expansion joint 21. If each

expansion joint

11, 21 is damaged, for example, if the first internal joint 14 or the second internal joint 24 is damaged, the air around the damaged area is cooled and liquid air is generated. The drip tray 50 can receive the liquid air that falls from the damaged area. Therefore, it is possible to prevent the upper deck 104 from being damaged due to temperature deformation caused by the liquid air falling onto the upper deck 104.

(Configuration of electrical system of piping equipment)
Next, the configuration of the electrical system of the piping equipment 100 according to this embodiment will be described. Fig. 3 is a block diagram of the piping equipment 100 according to this embodiment. As shown in Fig. 3, the piping equipment 100 includes a control device 90. The control device 90 includes a processor, a volatile memory, a non-volatile memory, an I/O interface, and the like. The non-volatile memory of the control device 90 stores a monitoring program and various data, which will be described later, and the processor performs arithmetic processing using the volatile memory based on each program.

The control device 90 is connected to the first thermometer 60 and the second thermometer 70, and can obtain the first gap temperature and the second gap temperature, respectively, based on signals received from these devices. Furthermore, the control device 90 is electrically connected to the first shutoff valve 16, the first gas supply valve 62, the first gas exhaust valve 64, the second shutoff valve 26, the second gas supply valve 72, and the second gas exhaust valve 74, and can open and close these valves by sending control signals to these valves.

The functions of the elements disclosed herein may be performed using circuits or processing circuits, including general purpose processors, special purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and/or combinations thereof, configured or programmed to perform the disclosed functions. Processors are considered processing circuits or circuits because they include transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and/or the processor.

(Monitoring Program)
Next, a monitoring program of this embodiment will be described. The monitoring program is a program for monitoring leakage of cryogenic fluid in the piping equipment 100 and taking appropriate measures. The monitoring program is executed by the control device 90. Fig. 4 is a flow diagram of the monitoring program.

As shown in FIG. 4, when the monitoring program is started, the control device 90 first acquires the first gap temperature and the second gap temperature (step S1). The first gap temperature and the second gap temperature can be acquired from the first thermometer 60 and the second thermometer 70.

The control device 90 then determines whether the first gap temperature acquired in step S1 is lower than a first reference temperature (step S2). As described above, if the first inner pipe 12 (particularly the first inner joint 14) is damaged and the low-temperature fluid leaks, the first gap temperature drops. Therefore, it is possible to determine whether a low-temperature fluid leak has occurred in the first inner pipe 12 depending on whether the first gap temperature is lower than a predetermined first reference temperature.

If the control device 90 determines in step S2 that the first gap temperature is lower than the first reference temperature (YES in step S2), that is, if it determines that a low-temperature fluid leak has occurred in the first inner pipe 12, it closes the pair of first shut-off valves 16 (step S3). If a low-temperature fluid leak has occurred in the first inner pipe 12, the leak is likely to be located in the first inner fitting 14. In this embodiment, the pair of first shut-off valves 16 located upstream and downstream of this first inner fitting 14 are closed, and the first shut-off section 17 in which the first inner fitting 14 is located is fluidly shut off.

After performing step S3, the control device 90 supplies inert gas to the first isolation section 17 (step S4). Specifically, the control device 90 sends a control signal to the first gas supply valve 62, which opens the first gas supply valve 62, thereby supplying inert gas to the first isolation section 17. Note that in this embodiment, the control device 90 opens the first gas exhaust valve 64 at the same time as opening the first gas supply valve 62. As a result, the low-temperature fluid in the first isolation section 17 is pushed out by the inert gas, which is then exhausted to the outside via the first gas exhaust pipe 63.

When steps S3 and S4 are carried out by the control device 90, the cryogenic fluid is discharged from the first shutoff section 17, so that repair work that may generate sparks, such as welding, can be carried out on the first internal fitting 14. At this time, it is no longer possible to transport the cryogenic fluid via the first piping 10, but it is possible to transport the cryogenic fluid via the second piping 20. Therefore, the transport of the cryogenic fluid in the piping equipment 100 can continue.

Returning to step S2, if the control device 90 determines that the first gap temperature is not lower than the first reference temperature (is equal to or higher than the first reference temperature) (NO in step S2), it proceeds to step S5. In step S5, the control device 90 determines whether the second gap temperature acquired in step S1 is lower than the second reference temperature. As in the case of step S2, whether a leak of low-temperature fluid has occurred in the second inner tube 22 can be determined depending on whether the second gap temperature is lower than the predetermined second reference temperature.

If the control device 90 determines in step S5 that the second gap temperature is not lower than the second reference temperature (is equal to or higher than the second reference temperature) (NO in step S5), it returns to step S1 and repeats each step.

On the other hand, if the control device 90 determines in step S5 that the second gap temperature is lower than the second reference temperature (YES in step S5), that is, if it determines that a low-temperature fluid leak has occurred in the second inner pipe 22, it closes the pair of second shutoff valves 26 (step S6). As a result, the second shutoff section 27 in which the second inner joint 24 is located is fluidically shut off by the second shutoff valves 26.

After performing step S6, the control device 90 supplies inert gas to the second cut-off section 27 (step S7). Specifically, the control device 90 supplies inert gas to the second cut-off section 27 by opening the second gas supply valve 72. In this embodiment, the control device 90 opens the second gas exhaust valve 74 at the same time as opening the second gas supply valve 72. This causes the low-temperature fluid in the second cut-off section 27 to be pushed out by the inert gas, which is then exhausted to the outside via the second gas exhaust pipe 73.

When steps S5 and S6 are carried out by the control device 90, the cryogenic fluid is discharged from the second cutoff section 27, so that repair work that may generate sparks, such as welding, can be carried out on the second internal fitting 24. At this time, it is no longer possible to transport the cryogenic fluid via the second piping 20, but it is possible to transport the cryogenic fluid via the first piping 10. Therefore, the transport of the cryogenic fluid in the piping equipment 100 can continue.

(Modification)
In the above, the control device 90 has been described as controlling the opening and closing of each valve based on the first gap temperature and the second gap temperature, but the opening and closing of each valve may be performed manually by an operator. When the opening and closing of each valve is performed manually, the control device 90 may be configured to output an alarm signal to a device such as a monitor or an alarm device when the first gap temperature becomes lower than the first reference temperature or when the second gap temperature becomes lower than the second reference temperature. With this configuration, the operator can easily grasp the timing to close each valve from the monitor, alarm device, etc.

In addition, in step S4 of the above monitoring program, the control device 90 opens the first gas supply valve 62 and the first gas exhaust valve 64 at the same time, so that the low-temperature fluid in the first cut-off section 17 is discharged to the outside via the first gas exhaust pipe 63. However, the low-temperature fluid in the first cut-off section 17 does not have to be discharged to the outside from the first gas exhaust pipe 63. For example, the low-temperature fluid in the first cut-off section 17 may be discharged via the first gas supply pipe 61. According to this method, the first gas exhaust pipe 63 and the first gas exhaust valve 64 can be omitted. For the same reason, the second gas exhaust pipe 73 and the second gas exhaust valve 74 can also be omitted.

In the above embodiment, the control device 90 judges whether or not the cryogenic fluid has leaked from the first inner tube 12 based on the temperature between the first inner tube 12 and the first outer tube 13 measured by the first thermometer 60, and judges whether or not the cryogenic fluid has leaked from the second inner tube 22 based on the temperature between the second inner tube 22 and the second outer tube 23 measured by the second thermometer 70. However, whether or not the cryogenic fluid has leaked from the first inner tube 12 and whether or not the cryogenic fluid has leaked from the second inner tube 22 may be judged by another method. For example, whether or not the cryogenic fluid has leaked from the first inner tube 12 may be judged based on the pressure or the concentration of the cryogenic fluid between the first inner tube 12 and the first outer tube 13, and whether or not the cryogenic fluid has leaked from the second inner tube 22 may be judged based on the pressure or the concentration of the cryogenic fluid between the second inner tube 22 and the second outer tube 23.

(summary)
A first item disclosed in this specification is a piping system connecting a liquefied gas tank that stores liquefied gas to related equipment, the piping system comprising: a first piping having a first expansion joint that can expand and contract in response to an external force, and transporting a cryogenic fluid, which is liquefied gas or a vaporized gas obtained by vaporizing liquefied gas, from the liquefied gas tank to the related equipment or from the related equipment to the liquefied gas tank; and a second piping having a second expansion joint that can expand and contract in response to an external force, positioned in parallel to the first piping, and transporting the same cryogenic fluid in the same direction as the first piping.

According to this configuration, even if the first expansion joint is damaged, the transport of the cryogenic fluid can continue through the second piping. Also, even if the second expansion joint is damaged, the transport of the cryogenic fluid can continue through the first piping.

The second item disclosed in this specification is the piping equipment described in the first item, in which the first piping includes a first inner pipe and a first outer pipe covering the first inner pipe, the second piping includes a second inner pipe and a second outer pipe covering the second inner pipe, the first expansion joint includes a first inner joint located on the first inner pipe and capable of expanding and contracting in response to an external force, the second expansion joint includes a second inner joint located on the second inner pipe and capable of expanding and contracting in response to an external force, a pair of first shutoff valves located upstream and downstream of the first inner joint of the first inner pipe and capable of fluidically isolating the first inner pipe, and a pair of second shutoff valves located upstream and downstream of the second inner joint of the second inner pipe and capable of fluidically isolating the second inner pipe.

With this configuration, if the pair of first shutoff valves are closed when the first internal joint is damaged, leakage of cryogenic fluid from the first internal joint can be prevented. Similarly, if the pair of second shutoff valves are closed when the second internal joint is damaged, leakage of cryogenic fluid from the first internal joint can be prevented.

The third item disclosed in this specification is the piping equipment described in the second item, which includes a first gas supply pipe connected to a first cut-off section located between the pair of first cut-off valves of the first inner pipe and capable of supplying an inert gas to the first cut-off section, and a second gas supply pipe connected to a second cut-off section located between the pair of second cut-off valves of the second inner pipe and capable of supplying an inert gas to the second cut-off section.

With this configuration, when the first internal joint is damaged, the pair of first shutoff valves can be closed to shut off the first shutoff section, and inert gas can be supplied to the first shutoff section via the first gas supply pipe. As a result, low-temperature fluid can be discharged from the first shutoff section where the first internal joint is located, and repair work can be performed that generates sparks for the first internal joint. For the same reason, when the second internal joint is damaged, low-temperature fluid can be discharged from the second shutoff section, and repair work can be performed that generates sparks for the second internal joint.

The fourth item disclosed in this specification is the piping equipment described in the third item, which includes a first gas exhaust pipe connected to a first cut-off section of the first inner pipe and capable of exhausting gas within the first cut-off section, and a second gas exhaust pipe connected to a second cut-off section of the second inner pipe and capable of exhausting gas within the second cut-off section.

With this configuration, when inert gas is supplied to the first isolation section, the low-temperature fluid in the first isolation section can be easily discharged to the outside via the first exhaust pipe. Similarly, when inert gas is supplied to the second isolation section, the low-temperature fluid in the second isolation section can be easily discharged to the outside via the second exhaust pipe.

The fifth item disclosed in this specification is the piping equipment described in any one of the second to fourth items, which includes a first safety pipe connected to a first shutoff section located between the pair of first shutoff valves of the first inner pipe, a second safety pipe connected to a second shutoff section located between the pair of second shutoff valves of the second inner pipe, a first safety valve located in the first safety pipe and opening when a pressure equal to or greater than a predetermined pressure is applied, and a second safety valve located in the second safety pipe and opening when a pressure equal to or greater than a predetermined pressure is applied.

This configuration makes it possible to prevent damage to the first and second inner tubes due to an excessive increase in the internal pressure of the first and second inner tubes.

The sixth item disclosed in this specification is the piping equipment described in any one of the first to fifth items, in which the first pipe and the second pipe are positioned symmetrically with respect to a vertical reference plane passing through the center of the liquefied gas tank and have a symmetrical shape with respect to the reference plane.

With this configuration, even if the liquefied gas tank is displaced relative to the associated equipment, the piping resistance of the first piping and the second piping can be kept at the same level.

The seventh item disclosed in this specification is the piping equipment described in any one of the first to sixth items, which is provided with a tank-side common pipe having one end connected to the liquefied gas tank and the other end connected to both the end of the first pipe on the liquefied gas tank side and the end of the second pipe on the liquefied gas tank side.

This configuration makes it possible to reduce the area occupied by the piping equipment near the liquefied gas tank.

The eighth item disclosed in this specification is the piping equipment described in any one of the first to fifth items, which is equipped with a control device that outputs a predetermined alarm signal when the low-temperature fluid leaks from the first inner pipe or when the low-temperature fluid leaks from the second inner pipe.

With this configuration, when a cryogenic fluid leak occurs in the first or second inner pipe, for example, an operator can recognize the occurrence and take appropriate action.

The ninth item disclosed in this specification is the piping equipment described in any one of the second to fifth items, which is equipped with a control device that closes the pair of first shutoff valves when the low-temperature fluid leaks from the first inner pipe, and closes the pair of second shutoff valves when the low-temperature fluid leaks from the second inner pipe.

　With this configuration, when the first or second internal joint is damaged and a cryogenic fluid leaks, the pair of first shutoff valves or the pair of second shutoff valves are automatically closed, thereby preventing the cryogenic fluid from leaking from the first or second internal joint.

The tenth item disclosed in this specification is a method for controlling piping equipment as described in claim 2, which closes the pair of first shutoff valves when the cryogenic fluid leaks from the first inner pipe, and closes the pair of second shutoff valves when the cryogenic fluid leaks from the second inner pipe.

　With this method, when the first or second internal joint is damaged and a cryogenic fluid leaks, the pair of first shutoff valves or the pair of second shutoff valves are closed, thereby preventing the cryogenic fluid from leaking from the first or second internal joint.

The eleventh item disclosed in this specification is a control method for piping equipment described in any one of the third to fifth items, in which, when the cryogenic fluid leaks from the first inner pipe, the pair of first shutoff valves are closed and an inert gas is supplied to the first shutoff section via the first gas supply pipe, and, when the cryogenic fluid leaks from the second inner pipe, the pair of second shutoff valves are closed and an inert gas is supplied to the second shutoff section via the second gas supply pipe.

　According to this method, when the first internal joint is damaged and a cryogenic fluid leaks, the cryogenic fluid can be discharged from the first blocking section where the first internal joint is located, and repair work can be performed that generates sparks for the first internal joint. Similarly, when the second internal joint is damaged and a cryogenic fluid leaks, the cryogenic fluid can be discharged from the second blocking section where the second internal joint is located, and repair work can be performed that generates sparks for the second internal joint.

10 First pipe 11 First expansion joint 12 First inner pipe 13 First outer pipe 14 First inner joint 15 First outer joint 16 First shutoff valve 17 First shutoff section 20 Second pipe 21 Second expansion joint 22 Second inner pipe 23 Second outer pipe 24 Second inner joint 25 Second outer joint 26 Second shutoff valve 27 Second shutoff section 30 Tank side common pipe 50 Drip tray 60 First thermometer 61 First gas supply pipe 63 First gas exhaust pipe 65 First safety pipe 66 First safety valve 70 Second thermometer 71 First gas supply pipe 73 Second gas exhaust pipe 75 Second safety pipe 76 Second safety valve 90 Control device 99 Reference plane 100 Piping equipment 101 Liquefied gas tank 102 Related equipment

Claims

A piping system that connects a liquefied gas tank that stores liquefied gas to related equipment,
A first pipe having a first expansion joint that can expand and contract in response to an external force, and transporting a cryogenic fluid that is a liquefied gas or a vaporized gas obtained by vaporizing the liquefied gas from the liquefied gas tank to the related equipment or from the related equipment to the liquefied gas tank;
a second piping having a second expansion joint that can expand and contract in response to an external force, the second piping being positioned in parallel to the first piping and transporting the same cryogenic fluid in the same direction as the first piping.
the first piping includes a first inner pipe and a first outer pipe covering the first inner pipe,
the second piping includes a second inner pipe and a second outer pipe covering the second inner pipe,
The first expansion joint includes a first inner joint located in the first inner pipe and capable of expanding and contracting in response to an external force,
The second expansion joint includes a second inner joint located in the second inner pipe and capable of expanding and contracting in response to an external force,
a pair of first shutoff valves located upstream and downstream of the first inner joint of the first inner pipe and capable of fluidly shutting off the first inner pipe;
The piping equipment according to claim 1 , further comprising: a pair of second shutoff valves located upstream and downstream of the second inner joint of the second inner pipe and capable of fluidly shutting off the second inner pipe.
a first gas supply pipe connected to a first isolation section located between the pair of first isolation valves of the first inner pipe and capable of supplying an inert gas to the first isolation section;
3. The piping equipment according to claim 2, further comprising: a second gas supply pipe connected to a second isolation section located between the pair of second isolation valves of the second inner pipe and capable of supplying an inert gas to the second isolation section.
a first gas exhaust pipe connected to a first cut-off section of the first inner pipe and capable of exhausting gas within the first cut-off section;
The piping equipment according to claim 3 , further comprising: a second gas exhaust pipe connected to a second blocked section of the second inner pipe and capable of exhausting gas within the second blocked section.
a first safety pipe connected to a first shutoff section located between the pair of first shutoff valves of the first inner pipe;
a second safety pipe connected to a second shutoff section located between the pair of second shutoff valves of the second inner pipe;
a first safety valve located in the first safety pipe and opening when a pressure equal to or greater than a predetermined pressure is applied;
3. The piping equipment according to claim 2, further comprising: a second safety valve located in the second safety pipe and opening when a pressure equal to or greater than a predetermined pressure is applied.
The piping equipment according to claim 1, wherein the first pipe and the second pipe are positioned symmetrically with respect to a vertical reference plane passing through the center of the liquefied gas tank and have a symmetric shape with respect to the reference plane.
The piping equipment according to claim 1, further comprising a tank-side common pipe having one end connected to the liquefied gas tank and the other end connected to both the end of the first pipe on the liquefied gas tank side and the end of the second pipe on the liquefied gas tank side.
The piping equipment according to claim 1, further comprising a control device that outputs a predetermined alarm signal when the low-temperature fluid leaks from the first inner pipe or when the low-temperature fluid leaks from the second inner pipe.
The piping equipment according to claim 2, further comprising a control device that closes the pair of first shutoff valves when the low-temperature fluid leaks from the first inner pipe, and closes the pair of second shutoff valves when the low-temperature fluid leaks from the second inner pipe.
The method for controlling piping equipment according to claim 2,
closing the pair of first shutoff valves when the cryogenic fluid leaks from the first inner pipe;
and closing the pair of second shutoff valves when the cryogenic fluid leaks from the second inner pipe.
The method for controlling piping equipment according to claim 3,
when the cryogenic fluid leaks from the first inner pipe, the pair of first shutoff valves are closed and an inert gas is supplied to the first shutoff section via the first gas supply pipe;
a second gas supply pipe for supplying an inert gas to the second shutoff section via the second gas supply pipe when the cryogenic fluid leaks from the second inner pipe;