Ammonia gas pipe facility, floating body, and control method of ammonia gas pipe facility

Abstract

To provide an ammonia gas pipe facility which enables reduction of condensation of an ammonia gas and damage risk of a burning appliance and a pipe while enabling replacement of the leaking ammonia gas with a fluid.SOLUTION: An ammonia gas pipe facility includes: an inner pipe forming an inner space in which an ammonia gas circulates; an outer pipe which encloses the inner pipe from the outer periphery side and forms an outer space with the inner pipe; a fluid introduction part for introducing a replacing fluid to be replaced with the ammonia gas leaking from the inner pipe into the outer space; a fluid discharge part which is provided spaced apart from the fluid introduction part in an ammonia gas circulation direction and discharges the replacing fluid from the outer space; and a temperature control part which heats the replacing fluid before it is introduced into the outer space.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an ammonia gas piping facility, a floating body, and a method for controlling an ammonia gas piping facility. [Background technology]

[0002] Patent Document 1 describes a ship that generates navigational power by burning fuel gas such as LNG (liquefied natural gas) in a gas engine. Patent Document 1 also describes a configuration that employs a so-called double-pipe structure in which a fuel supply pipe (in other words, an inner pipe) is covered with a duct (in other words, an outer pipe) in a gas fuel supply system from the viewpoint of preventing accidents caused by leakage, and constantly ventilates the space between the fuel supply pipe and the duct. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-97162 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in combustion devices such as engines and boilers, ammonia may be used as a decarbonized fuel. Even when ammonia is used as the fuel in this way, it is recommended to use a double-pipe structure piping as described in Patent Document 1 from the viewpoint of preventing leakage. Ammonia as a fuel may be supplied to a consumer in a gaseous state, more specifically, in a superheated steam state. However, in the case of a double-pipe structure as in Patent Document 1, that is, in which the space between the inner pipe and the outer pipe is constantly ventilated to allow ammonia gas leaking from the inner pipe to be replaced with a fluid, the saturation temperature of ammonia gas at the same pressure is higher than that of natural gas, so there is a possibility that the ammonia gas will undergo a phase change and condense. If ammonia liquid is produced inside the inner pipe, it will not be possible to supply ammonia as a gas to the combustion device, and there is a possibility that the combustion device that uses ammonia gas as fuel and the piping through which the ammonia gas flows will be damaged due to the water hammer phenomenon, etc.

[0005] The present disclosure has been made in consideration of the above circumstances, and provides an ammonia gas piping facility, a float, and a method for controlling an ammonia gas piping facility that can replace leaked ammonia gas while reducing the risk of ammonia gas condensation and damage to combustion equipment and piping. [Means for solving the problem]

[0006] In order to solve the above problems, the following configuration is adopted. According to one aspect of the present disclosure, an ammonia gas piping system includes an inner pipe forming an inner space inside through which ammonia gas flows, an outer pipe surrounding the inner pipe from the outer periphery and forming an outer space between the inner pipe and the outer pipe, a fluid inlet portion introducing a replacement fluid to replace ammonia gas leaked from the inner pipe into the outer space, a fluid outlet portion provided at a distance from the fluid inlet portion in the flow direction of the ammonia gas and discharging the replacement fluid from the outer space, and a temperature adjustment portion heating the replacement fluid before being introduced into the outer space.

[0007] According to one aspect of the present disclosure, a floating body includes an ammonia gas piping facility, an ammonia gas supply device that supplies the ammonia gas, and a combustion device that uses the ammonia gas as fuel.

[0008] According to one aspect of the present disclosure, a method for controlling an ammonia gas piping system includes a step of heating the replacement fluid so that a temperature of the replacement fluid discharged from the inner pipe is equal to or lower than a temperature of the replacement fluid introduced into the inner pipe.

[0009] According to one aspect of the present disclosure, a method for controlling an ammonia gas piping system includes a step of heating the replacement fluid so that a temperature of the ammonia gas in a downstream portion of the inner pipe is equal to or higher than a temperature of the ammonia gas in an upstream portion of the inner pipe. Effect of the Invention

[0010] According to the present disclosure, it is possible to condense ammonia gas and replace leaked ammonia gas, while reducing the risk of damage to combustion equipment and piping. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a diagram showing a schematic configuration of a floating body in the first embodiment of the present disclosure. [Diagram 2] FIG. 1 is a diagram showing a schematic configuration of an ammonia gas piping facility according to a first embodiment of the present disclosure. [Diagram 3] FIG. 2 is a diagram illustrating a hardware configuration of a control device in the first embodiment of the present disclosure. [Figure 4] FIG. 2 is a functional block diagram of a control device according to the first embodiment of the present disclosure. [Diagram 5] 1 is a flowchart of a method for controlling an ammonia gas piping facility in the first embodiment of the present disclosure. [Figure 6] 11 is a flowchart of a method for controlling an ammonia gas piping facility in a first modified example of the first embodiment of the present disclosure. [Figure 7] 13 is a flowchart of a method for controlling an ammonia gas piping facility in a second modified example of the first embodiment of the present disclosure. [Figure 8] FIG. 11 is a diagram showing a schematic configuration of an ammonia gas piping facility according to a second embodiment of the present disclosure. [Figure 9] FIG. 13 is a diagram showing a schematic configuration of an ammonia gas piping facility according to a third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an ammonia gas piping facility, a float, and a method for controlling an ammonia gas piping facility according to an embodiment of the present disclosure will be described with reference to the drawings. First Embodiment (Floating body) FIG. 1 is a diagram showing a schematic configuration of a floating body according to a first embodiment of the present disclosure. As shown in FIG. 1, the float 1 of the first embodiment includes at least a float body 2, an upper structure 4, a combustion device 8, an ammonia tank 10, an ammonia fuel adjustment room 20, and an ammonia gas piping system 30. The float 1 of the present embodiment will be described as an example of a ship that can navigate by a main engine or the like. The type of ship of the float 1 is not limited to a specific type of ship. Examples of the ship type include a liquefied gas carrier having a combustion device that uses ammonia as fuel, a ferry, a RORO ship, a car carrier, a passenger ship, an ammonia transport ship, and a multipurpose gas carrier that can transport ammonia and liquefied gas other than ammonia. Examples of the float 1 include an ammonia FSU (Floating Storage Unit), an ammonia FSRU (Floating Storage and Regasification Unit), and the like.

[0013] (Floating body) The floating body 2 has a pair of side panels 5A, 5B that form its outer hull, and a ship bottom 6. The side panels 5A, 5B each have a pair of side panel shells that form the starboard and port sides, respectively. The ship bottom 6 has a ship bottom panel that connects the side panels 5A, 5B. The floating body 2 of this embodiment further has an upper deck 7, which is a full-length deck located at the topmost layer. The superstructure 4 is formed on the upper deck 7, and has accommodation areas and the like provided therein. In the floating body 1 of this embodiment, for example, a cargo space (not shown) for carrying cargo is provided on the bow 3a side in the bow-stern direction FA from the superstructure 4.

[0014] (Combustion equipment) The combustion device 8 is a device that generates thermal energy by burning fuel, and is provided inside the floating body 2. Examples of the combustion device 8 include an internal combustion engine that serves as a power source for propelling the floating body 1, an internal combustion engine used in a power generation facility that supplies electricity to the ship, and a boiler that generates steam as a working fluid. The combustion device 8 exemplified in this embodiment is an internal combustion engine that serves as a power source for propelling the floating body 1, and is capable of switching between ammonia and other fuels different from ammonia, such as heavy oil, as the fuel.

[0015] (Ammonia tank) The ammonia tank 10 is a tank that stores liquid ammonia (hereinafter referred to as liquefied ammonia). The ammonia tank 10 of this embodiment is a fuel tank that stores liquefied ammonia that serves as fuel for the combustion device 8. The ammonia tank 10 illustrated in this first embodiment is installed on the upper deck 7 on the bow 3a side of the superstructure 4, but this arrangement of the ammonia tank 10 is only an example, and the arrangement of the ammonia tank 10 is not limited to being on the upper deck 7 on the bow 3a side of the superstructure 4.

[0016] (Ammonia fuel conditioning chamber) The ammonia fuel preparation chamber 20 is equipped with various ammonia fuel devices (not shown) that vaporize the liquefied ammonia supplied from the ammonia tank 10. In the ammonia fuel preparation chamber 20, the pressure and temperature of the ammonia gas Ga are adjusted so that the vaporized ammonia gas Ga is in a superheated vapor region. In addition, in the ammonia fuel preparation chamber 20, the temperature of the ammonia gas Ga is adjusted so as to be within the temperature range required by the combustion device 8. The ammonia fuel preparation chamber 20 corresponds to the ammonia gas supply device in this disclosure.

[0017] (Ammonia gas piping equipment) FIG. 2 is a diagram showing a schematic configuration of an ammonia gas piping facility in the first embodiment of the present disclosure. The ammonia gas piping equipment 30 supplies ammonia gas Ga as fuel to the combustion device 8. The ammonia gas piping equipment 30 of this embodiment guides the ammonia gas Ga vaporized by the ammonia fuel adjustment chamber 20 to the combustion device 8. The ammonia gas piping equipment 30 includes an inner pipe 31, an outer pipe 32, a fluid introduction section 33, a fluid discharge section 34, a temperature adjustment section 35, a plurality of sensors 50, and a control device 51.

[0018] The inner pipe 31 forms an inner space 40 inside, through which the ammonia gas Ga flows. The inner pipe 31 of the present embodiment guides the ammonia gas Ga, the temperature and pressure of which have been adjusted, from the ammonia fuel preparation chamber 20 to the combustion device 8. Here, the temperature and pressure of the ammonia gas Ga are adjusted in the ammonia fuel preparation chamber 20 so as to be within the temperature and pressure ranges required by the combustion device 8.

[0019] The outer pipe 32 surrounds the inner pipe 31 from the outer periphery side and forms an outer space 41 between the inner pipe 31 and the outer pipe 32. That is, the inner pipe 31 and the outer pipe 32 form a so-called double pipe structure. The outer pipe 32 can be formed so as to surround the inner pipe 31 in, for example, a region that cannot handle ammonia leakage, among the region between the ammonia fuel conditioning chamber 20 and the combustion device 8. The outer pipe 32 may, for example, cover the entire inner pipe 31 in the extending direction of the inner pipe 31, or may cover a part of the inner pipe 31 in the extending direction of the inner pipe 31.

[0020] The fluid introduction section 33 introduces a replacement fluid Fr to replace the ammonia gas Ga leaked from the inner tube 31 into the outer space 41. The replacement fluid Fr is a fluid for replacing the leaked ammonia gas Ga when the ammonia gas Ga leaks from the inner tube 31 into the outer space 41. In this embodiment, outside air (ventilation air) taken in by a fan or the like for ventilation in the floating body 1 is used. The fluid introduction section 33 in this embodiment is provided at a position close to one end in the extension direction of the outer tube 32. The fluid introduction section 33 in this embodiment is provided on the side closer to the combustion device 8, in other words, near the end of the most downstream side Dfd in the flow direction Df of the ammonia gas Ga. The fluid introduction section 33 may be provided, for example, at the end of the outer tube 32 on the most downstream side Dfd in the flow direction Df of the ammonia gas Ga.

[0021] The fluid discharge part 34 discharges the replacement fluid Fr from the outer space 41. The fluid discharge part 34 is provided apart from the fluid introduction part 33 in the flow direction Df of the ammonia gas Ga. The fluid discharge part 34 in this embodiment is provided at a position close to the other end, which is the end opposite to the one end, in the extension direction of the outer tube 32. The fluid discharge part 34 in this embodiment is provided on the side close to the ammonia fuel conditioning chamber 20, in other words, near the end of the most upstream side Dfu in the flow direction Df of the ammonia gas Ga. The fluid discharge part 34 may be provided, for example, at the end of the outer tube 32 at the most upstream side Dfu in the flow direction Df of the ammonia gas Ga.

[0022] That is, the replacement fluid Fr of this embodiment flows into the outer space 41 from the fluid introduction part 33, flows in the outer space 41 from the downstream side Dfd to the upstream side Dfu in the flow direction Df of the ammonia gas Ga, and is discharged from the fluid discharge part 34 to the outside of the outer space 41. In this embodiment, the replacement fluid Fr flows countercurrently to the ammonia gas Ga, but is not limited to the countercurrent. The replacement fluid Fr may flow parallel to the ammonia gas Ga. In addition, the flow rate of the replacement fluid Fr flowing through the outer space 41 of this embodiment is always constant, but the flow rate of the replacement fluid Fr flowing through the outer space 41 may change.

[0023] The temperature adjustment unit 35 heats the replacement fluid Fr before it is introduced into the outer space 41. In other words, the temperature adjustment unit 35 is capable of increasing the temperature of the replacement fluid Fr to a desired temperature before it is introduced into the outer space 41. The temperature adjustment unit 35 of this embodiment is capable of increasing the temperature of the replacement fluid Fr to a temperature equal to or higher than the temperature of the ammonia gas Ga flowing through the inner space 40. Examples of the temperature adjustment unit 35 include a heater and a heat exchanger. The temperature adjustment unit 35 is controlled by a control device 51.

[0024] (sensor) The multiple sensors 50 detect at least one of the temperature of the replacement fluid Fr and the temperature of the ammonia gas Ga in the inner space 40. The detection results by the multiple sensors 50 are input to the control device 51. In this embodiment, the multiple sensors 50 include a first temperature sensor 50a that detects a temperature T1 of the replacement fluid Fr in the fluid inlet portion 33, a second temperature sensor 50b that detects a temperature T2 of the replacement fluid Fr in the fluid outlet portion 34, a third temperature sensor 50c that detects a temperature Ta1 of the ammonia gas Ga in the upstream portion of the inner pipe 31, a fourth temperature sensor 50d that detects a temperature Ta2 of the ammonia gas Ga in the downstream portion of the inner pipe 31, a first pressure sensor 50e that detects a pressure Pa1 of the ammonia gas Ga in the upstream portion of the inner pipe 31, and a second pressure sensor 50f that detects a pressure Pa2 of the ammonia gas Ga in the downstream portion of the inner pipe 31. In this embodiment, the first temperature sensor 50a detects the temperature T1 of the replacement fluid Fr immediately before it is introduced into the outer space 41, and the second temperature sensor 50b detects the temperature T2 of the replacement fluid Fr immediately after it is discharged from the outer space 41.

[0025] Here, the upstream part of the inner pipe 31 is a part of the inner pipe 31 adjacent to an end part of the outer space 41 on the most upstream side Dfu in the flow direction Df. The downstream part of the inner pipe 31 is a part of the inner pipe 31 adjacent to an end part of the outer space 41 on the most downstream side Dfd in the flow direction Df. In other words, the temperature Ta1 and the pressure Pa1 are the temperature and pressure of the ammonia gas Ga immediately before it flows into the double pipe structure, and the temperature Ta2 and the pressure Pa2 are the temperature and pressure of the ammonia gas Ga immediately after it flows out of the double pipe structure.

[0026] (Control device) Fig. 3 is a diagram illustrating a hardware configuration of the control device in the first embodiment of the present disclosure Fig. 4 is a functional block diagram of the control device in the first embodiment of the present disclosure. As shown in FIG. 3, the control device 51 is a computer including a central processing unit (CPU) 61, a read only memory (ROM) 62, a random access memory (RAM) 63, a storage 64 such as a hard disk drive (HDD), and a signal transmission / reception module 65.

[0027] As shown in FIG. 4, the CPU 61 of the control device 51 executes programs stored in the ROM 62 or storage 64 to realize the functional configurations of a temperature acquisition unit 71, a pressure acquisition unit 72, a temperature control unit 73, and a command signal output unit 74.

[0028] The temperature acquisition unit 71 acquires at least one of the temperature of the replacement fluid Fr and the temperature of the ammonia gas Ga. As shown in Fig. 2 and Fig. 4, the temperature acquisition unit 71 of this embodiment acquires the temperatures T1, T2 of the replacement fluid Fr and the temperatures Ta1, Ta2 of the ammonia gas Ga from the first temperature sensor 50a, the second temperature sensor 50b, the third temperature sensor 50c, and the fourth temperature sensor 50d, respectively. Note that in the first embodiment, acquisition of the temperature Ta1 may be omitted.

[0029] The pressure acquisition unit 72 acquires the pressure of the ammonia gas Ga. The pressure acquisition unit 72 in this embodiment acquires the pressures Pa1 and Pa2 of the ammonia gas Ga from the first pressure sensor 50e and the second pressure sensor 50f, respectively. Note that in the first embodiment, acquisition of the pressure Pa1 may be omitted. For example, when the pressure Pa1 is acquired, it can be confirmed that the ammonia gas Ga flowing in the upstream part of the inner pipe 31 is superheated steam based on the temperature Ta1 and the pressure Pa1.

[0030] The temperature control unit 73 controls the temperature adjustment unit 35 based on the temperature acquired by the temperature acquisition unit 71. The temperature control unit 73 of this embodiment controls the temperature adjustment unit 35 based on the temperature acquired by the temperature acquisition unit 71 and the pressure acquired by the pressure acquisition unit 72. The temperature control unit 73 of this embodiment also controls the temperature adjustment unit 35 so that the temperature T2 of the replacement fluid Fr in the fluid discharge unit 34 is equal to or lower than the temperature T1 of the replacement fluid Fr in the fluid introduction unit 33 (T1≧T2).

[0031] Furthermore, the temperature control unit 73 of this embodiment controls the temperature adjustment unit 35 based on the pressure P2 of the ammonia gas Ga at the downstream part of the inner pipe 31 and the temperature Ta2 of the ammonia gas Ga at the downstream part of the inner pipe 31 while satisfying the above-mentioned condition T1 ≧ T2, so that the temperature Ta2 of the ammonia gas Ga at the downstream part of the inner pipe 31 is in the superheated steam region. Here, since the saturation temperature of the ammonia gas Ga can be obtained from the pressure P2, the temperature control unit 73 controls the temperature adjustment unit 35 so that the temperature Ta2 is in the superheated steam region with a predetermined margin from the saturation temperature while satisfying the condition T1 ≧ T2. Note that, when the upper limit temperature of the ammonia gas Ga is determined at the supply destination (combustion device 8) of the ammonia gas Ga, the temperature control unit 73 may control the temperature adjustment unit 35 so that the temperature Ta2 does not exceed this upper limit temperature.

[0032] The command signal output unit 74 outputs a command signal for controlling the temperature adjustment unit 35 output from the temperature control unit 73 to the temperature adjustment unit 35 .

[0033] (Control method for ammonia gas piping equipment) FIG. 5 is a flowchart of a method for controlling an ammonia gas piping facility in the first embodiment of the present disclosure. As shown in FIG. 5, the control method for the ammonia gas piping equipment 30 in the first embodiment includes a step S10 of heating the replacement fluid so that the temperature of the replacement fluid discharged from the outer space is equal to or lower than the temperature of the replacement fluid introduced into the outer space, and a step S11 of heating the replacement fluid so that the temperature of the ammonia gas Ga in the downstream part of the inner tube is in the superheated vapor region.

[0034] In step S10, in which the replacement fluid is heated so that the temperature of the replacement fluid discharged from the outer space is equal to or lower than the temperature of the replacement fluid introduced into the outer space, the replacement fluid Fr is heated so that the temperature T2 is equal to or lower than the temperature T1. That is, in step S10, the temperature of the replacement fluid Fr is increased so that the replacement fluid Fr introduced into the outer space 41 does not take away the thermal energy of the ammonia gas Ga in the inner space 40. For example, when the temperature T2 is higher than the temperature T1, it is estimated that the thermal energy of the ammonia gas Ga is transferred to the replacement fluid Fr. Therefore, in step S10, when the temperature T2 is higher than the temperature T1, the temperature of the replacement fluid Fr before being introduced into the outer space 41 is increased by the temperature adjustment unit 35. On the other hand, when the temperature T2 is equal to or lower than the temperature T1, the process proceeds to the next step.

[0035] In step S11, the replacement fluid is heated so that the temperature of the ammonia gas Ga in the downstream part of the inner tube is in the superheated steam region. The saturation temperature of the ammonia gas Ga is calculated based on the pressure Pa2, and the replacement fluid Fr is heated so that the temperature Ta2 is in the superheated steam region based on the calculated saturation temperature. In this step S11, if the temperature Ta2 is not in the superheated steam region, the temperature of the replacement fluid Fr is increased until the temperature Ta2 is in the superheated steam region. On the other hand, if the temperature Ta2 is in the superheated steam region, the process returns to step S10.

[0036] (Action and effect) In the above-described first embodiment, the ammonia gas piping equipment 30 is provided with a temperature adjustment unit 35 that heats the replacement fluid Fr before it is introduced into the outer space 41 between the inner pipe 31 and the outer pipe 32 that form the double pipe structure. With this configuration, for example, a decrease in temperature of the replacement fluid Fr can be suppressed, and therefore a decrease in temperature of the ammonia gas Ga caused by heat exchange between the ammonia gas Ga flowing through the inner space 40 of the inner pipe 31 and the replacement fluid Fr can be suppressed. Therefore, the ammonia gas Ga flowing through the inner space 40 of the inner pipe 31 can be suppressed from condensing and liquefying. Therefore, while making it possible to replace the ammonia gas Ga leaked from the inner pipe 31 to the outer space 41 with the replacement fluid Fr, it is ensured that ammonia is supplied in a gaseous state to the combustion device 8, and the risk of damage to the combustion device 8 or the piping system through which the ammonia gas Ga flows due to ammonia droplets can be reduced.

[0037] Furthermore, in the above first embodiment, the control device 51 is provided with a temperature acquisition unit 71 that acquires the temperature of at least one of the replacement fluid Fr and the ammonia gas Ga, and a temperature control unit 73 that controls the temperature adjustment unit 35 based on the temperature acquired by the temperature acquisition unit 71. By configuring in this manner, in a situation where the replacement fluid Fr takes away the thermal energy of the ammonia gas Ga and the temperature of the ammonia gas Ga drops, the replacement fluid Fr can be automatically heated to suppress the drop in temperature of the ammonia gas Ga.

[0038] In the first embodiment, the temperature acquisition unit 71 acquires the temperature T1 of the replacement fluid Fr in the fluid inlet portion 33 and the temperature T2 of the replacement fluid Fr in the fluid outlet portion 34. The temperature control unit 73 controls the temperature adjustment unit 35 so that the temperature T2 of the replacement fluid Fr in the fluid outlet portion 34 is equal to or lower than the temperature T1 of the replacement fluid Fr in the fluid inlet portion 33. This makes it possible to suppress the temperature of the replacement fluid Fr introduced from the fluid introduction part 33 into the outer space 41 from increasing when it is discharged from the fluid discharge part 34, that is, to suppress the enthalpy of the replacement fluid Fr from increasing as a result of flowing through the outer space 41. Therefore, it is possible to suppress the thermal energy of the ammonia gas Ga from being transferred to the replacement fluid Fr.

[0039] Furthermore, in the first embodiment, a pressure acquisition unit 72 is provided that acquires a pressure Pa2 of the ammonia gas Ga in the downstream portion of the inner pipe 31. The temperature acquisition unit 71 further acquires a temperature Ta2 of the ammonia gas Ga in the downstream portion of the inner pipe 31. The temperature control unit 73 controls the temperature adjustment unit 35 based on the pressure Pa2 and the temperature Ta2 so that the temperature Ta2 of the ammonia gas Ga in the downstream portion of the inner pipe 31 is in the superheated steam range. This makes it possible to maintain the state of the ammonia gas Ga flowing through the inner pipe 31 in a superheated vapor state. Therefore, condensation of the ammonia gas Ga flowing through the inner pipe 31 can be further suppressed.

[0040] First Modification of the First Embodiment FIG. 6 is a flowchart of a method for controlling an ammonia gas piping system in a first modified example of the first embodiment of the present disclosure. In the above-described first embodiment, the temperature T1 and temperature T2 of the replacement fluid Fr are acquired, and the temperature adjustment unit 35 is controlled so that the temperature T2 is equal to or lower than the temperature T1. However, the present invention is not limited to this configuration. For example, the temperature control unit 73 may control the temperature adjustment unit 35 so that the temperature Ta2 of the ammonia gas Ga is equal to or higher than the temperature Ta1. In other words, as shown in FIG. 6, instead of the step S10 in FIG. 5, a step S20 may be performed in which the replacement fluid is heated so that the temperature of the ammonia gas at the downstream part of the inner tube is equal to or higher than the temperature of the ammonia gas at the upstream part of the inner tube.

[0041] Furthermore, without being limited to the configuration of the first modified example, for example, the temperature control unit 73 may control the temperature adjustment unit 35 so that the temperature T2 is equal to or lower than the temperature T1 (T1≧T2) and the temperature Ta2 is equal to or higher than the temperature Ta1 (Ta2≧Ta1). The temperature control unit 73 may also control the temperature adjustment unit 35 so that the above T1≧T2 and Ta2≧Ta1 and the temperature Ta2 of the ammonia gas Ga in the downstream part of the inner tube 31 is equal to the temperature of the superheated steam region based on the pressure Pa2 and temperature Ta2 of the ammonia gas Ga in the downstream part of the inner tube 31. In this way, redundancy can be provided.

[0042] Second Modification of First Embodiment FIG. 7 is a flowchart of a method for controlling an ammonia gas piping system in a second modified example of the first embodiment of the present disclosure. In the above-described first embodiment and the first modified example of the first embodiment, the control for heating the replacement fluid Fr has been described based on the temperatures T1, T2 of the replacement fluid Fr and the temperatures Ta1, Ta2 of the ammonia gas Ga. However, the present invention is not limited to this configuration, and for example, when it is estimated that the ammonia gas Ga flowing through the inner pipe 31 is not superheated steam, the temperature control unit 73 may control the replacement fluid Fr to be heated by the temperature adjustment unit 35 so that the ammonia gas Ga becomes superheated steam.

[0043] As shown in FIG. 7, the control method for an ammonia gas piping system in the second modified example of the first embodiment includes a step S30 of determining whether or not the ammonia gas is in a superheated vapor state, and a step S31 of heating the replacement fluid so that the temperature of the ammonia gas in the downstream portion is in the superheated vapor region. In step S30, it is determined whether the ammonia gas Ga is in a superheated vapor state in the downstream portion. Specifically, the saturation temperature of the ammonia gas Ga is calculated based on the pressure Pa2, and it is determined whether the temperature Ta2 is in a superheated vapor region with a predetermined margin from the saturation temperature. If it is determined in step S30 that the temperature Ta2 of the ammonia gas Ga is not in a superheated vapor region with a predetermined margin from the saturation temperature ("No" in S30), the process proceeds to step S31. In step S31, the temperature of the replacement fluid Fr is increased until the temperature Ta2 is in the superheated vapor region, while the heating of the replacement fluid Fr is stopped when the temperature Ta2 is in the superheated vapor region with a predetermined margin from the saturation temperature, and the process returns to step S30.

[0044] According to this second modified example, when the temperature of the ammonia gas Ga in the downstream portion of the inner tube 31 drops and it is likely to no longer be superheated vapor, the replacement fluid Fr can be heated to increase the temperature of the ammonia gas Ga in the downstream portion, thereby maintaining the state of superheated vapor, thereby suppressing condensation of the ammonia gas Ga.

[0045] Second Embodiment Next, a second embodiment of the present disclosure will be described with reference to the drawings. This second embodiment differs from the first embodiment described above only in that the humidity of the replacement fluid Fr is reduced. Therefore, the same parts as those in the first embodiment described above are denoted by the same reference numerals and will not be described again.

[0046] FIG. 8 is a diagram showing a schematic configuration of an ammonia gas piping facility in the second embodiment of the present disclosure. 8, the ammonia gas piping equipment 130 in the second embodiment includes an inner pipe 31, an outer pipe 32, a fluid inlet section 33, a fluid outlet section 34, a temperature adjustment section 35, a plurality of sensors 50, and a control device 51, similar to the ammonia gas piping equipment 30 in the first embodiment described above. The ammonia gas piping equipment 130 in the second embodiment further includes a dehumidifier 80 in addition to the above configuration. The ammonia gas piping equipment 130 in the second embodiment uses ventilation air as the replacement fluid Fr.

[0047] The dehumidifier 80 dehumidifies the ventilation air, which is the replacement fluid Fr introduced from the fluid introduction section 33 into the outer space 41. The dehumidifier 80 of this embodiment is installed upstream of the replacement fluid Fr (opposite the outer pipe 32) from the temperature adjustment section 35. Examples of the dehumidifier 80 include dehumidifiers of an adsorption type or a refrigeration type. The location of the dehumidifier 80 is not limited to the above installation position, and it may be installed, for example, between the temperature adjustment section 35 and the outer pipe 32.

[0048] (Action and effect) According to the second embodiment, since the humidity of the replacement fluid Fr can be reduced, for example, it is possible to suppress condensation of moisture in the replacement fluid Fr in the outer space 41. Therefore, when the ammonia gas Ga leaks, it is possible to suppress water (ammonia water) that has absorbed the ammonia gas Ga from remaining in the outer space 41.

[0049] Modification of the Second Embodiment In the second embodiment, the case where the dehumidifier 80 is provided has been described. However, this is not limited to the above. For example, a gas with a low dew point may be used as the replacement fluid Fr without providing the dehumidifier 80. Here, the gas with a low dew point is obtained by increasing the pressure of the ventilation air to condense and separate the moisture contained in the ventilation air. For example, in a floating body 1 such as a ship, starting compressed air for starting an internal combustion engine that has been decompressed can be used as the gas with a low dew point.

[0050] Third Embodiment Next, a third embodiment of the present disclosure will be described with reference to the drawings. The third embodiment differs from the first embodiment described above only in that a heat shield is provided. Therefore, the same parts as those in the first embodiment described above are denoted by the same reference numerals and will not be described again.

[0051] FIG. 9 is a diagram showing a schematic configuration of an ammonia gas piping system according to the third embodiment of the present disclosure. 9, the ammonia gas piping equipment 230 in the third embodiment includes an inner pipe 31, an outer pipe 32, a fluid inlet section 33, a fluid outlet section 34, a temperature adjustment section 35, a plurality of sensors 50, and a control device 51, similar to the ammonia gas piping equipment 30 in the first embodiment described above. The ammonia gas piping equipment 230 in the third embodiment further includes a heat insulating section 90 in addition to the above configuration.

[0052] The heat insulating part 90 suppresses heat radiation from the outer surface of the outer pipe 32. The heat insulating part 90 in this embodiment is installed so as to cover the outer surface of the outer pipe 32. Examples of the heat insulating part 90 include glass wool and a foam material of a synthetic resin (e.g., urethane). Note that the heat insulating part 90 may have any configuration as long as it is capable of preventing heat radiation from the outer surface of the outer pipe 32.

[0053] (Action and effect) According to the third embodiment, it is possible to keep warm the replacement fluid Fr flowing through the outer space 41. Therefore, it is possible to reduce the energy required to heat the replacement fluid Fr. In addition, a heat insulating portion 90 may be provided on the outer pipe 32 of the ammonia gas piping equipment 130 of the second embodiment.

[0054] Other Embodiments The present disclosure is not limited to the configurations of the above-described embodiments, and design changes are possible without departing from the spirit of the present disclosure. For example, in each of the above-mentioned embodiments and the modified examples of each embodiment, the case where the ammonia gas piping equipment 30 is provided on the floating body 1 has been described as an example, but the ammonia gas piping equipment 30 is not limited to being provided on the floating body 1. For example, the ammonia gas piping equipment 30 may be applied to a land-based facility having a combustion device that uses ammonia as fuel.

[0055] Furthermore, in the above-mentioned embodiments and the modified examples of the embodiments, the float 1 is mainly used to navigate on the water, but the float 1 is not limited to a float mainly used to navigate on the water. The float 1 may be, for example, an ammonia FSU or an ammonia FSRU, which is not used to navigate on the water, or is rarely used to navigate on the water. In this case, for example, liquefied ammonia stored in a storage tank (not shown) provided in the float body of the float 1 may be supplied to the ammonia fuel conditioning chamber 20 to be turned into superheated steam, and the ammonia gas turned into superheated steam in the ammonia fuel conditioning chamber 20 may be supplied to a fuel device (not shown) outside the float 1 through the ammonia gas piping equipment 30, or may be supplied to a combustion device such as a power generation equipment inside the float that is not a power source. The arrangement of the storage tank (not shown) in the float body is not limited in any way.

[0056] Further, in each of the above embodiments and the modified examples of each embodiment, the case where the ammonia tank 10 is a fuel tank has been described. However, the ammonia tank 10 may be a cargo tank (not shown) that stores liquefied ammonia as cargo. Furthermore, in the above-mentioned embodiments and the modified examples of the embodiments, the case where one combustion device 8, one piping equipment 30, 130, 230, and one ammonia tank 10 are provided on one floating body 1 is illustrated, but the number is not limited to one. The combustion device 8, the piping equipment 30, 130, 230, and the ammonia tank 10 may each be provided in a plurality as necessary.

[0057] In addition, in each of the above-described embodiments and each of the modified examples of each embodiment, the temperature control unit 73 adjusts the temperature adjustment unit 35 so that the ammonia gas Ga is in the superheated vapor region, but this is not limited to the configuration. For example, the temperature control unit 73 may control the temperature adjustment unit 35 based only on the temperatures T1 and T2, or may control the temperature adjustment unit 35 based only on the temperatures Ta1 and Ta2.

[0058] Furthermore, in the above-described embodiments and the modified examples of the embodiments, the replacement fluid Fr is the outside air, but the replacement fluid Fr may be a liquid. Examples of the replacement fluid Fr that is a liquid include fresh water and antifreeze containing a rust inhibitor. In addition, a part of the replacement fluid Fr discharged from the fluid discharge portion 34 may be returned to the fluid introduction portion 33 and circulated (circulated) in the outer space 41. Furthermore, in each of the above embodiments and modified examples, a case has been described in which the temperature Ta2 is raised so that it becomes a temperature in the superheated steam region with a predetermined margin from the saturation temperature, but the predetermined margin may be set appropriately or may be omitted.

[0059] <Additional Notes> The ammonia gas piping equipment, the float, and the control method for the ammonia gas piping equipment described in each embodiment can be understood, for example, as follows.

[0060] (1) According to the first aspect, the ammonia gas piping equipment 30, 130, 230 includes an inner pipe 31 forming an inner space 40 inside through which ammonia gas Ga flows, an outer pipe 32 surrounding the inner pipe 31 from the outer periphery side and forming an outer space 41 between the inner pipe 31 and the outer pipe 32, a fluid inlet 33 for introducing a replacement fluid Fr to replace the ammonia gas Ga leaked from the inner pipe 31 into the outer space 41, a fluid outlet 34 provided at a distance from the fluid inlet 33 in the flow direction Df of the ammonia gas Ga and for discharging the replacement fluid Fr from the outer space 41, and a temperature adjustment unit 35 for heating the replacement fluid Fr before being introduced into the outer space 41. Examples of replacement fluids include ventilation air, fresh water, antifreeze, and the like.

[0061] This makes it possible to prevent the temperature of the ammonia gas Ga from decreasing, making it possible to replace the ammonia gas Ga leaking from the inner tube 31 into the outer space 41 with the replacement fluid Fr, while reducing the risk of damage to the combustion device 8 or the piping system through which the ammonia gas Ga flows due to ammonia droplets.

[0062] (2) According to a second aspect, the ammonia gas piping equipment 30, 130, 230 is the ammonia gas piping equipment 30, 130, 230 of (1), and is provided with a control device 51 that controls the temperature adjustment unit 35, and the control device 51 is provided with a temperature acquisition unit 71 that acquires a temperature of at least one of the replacement fluid Fr and the ammonia gas Ga, and a temperature control unit 73 that controls the temperature adjustment unit 35 based on the temperature acquired by the temperature acquisition unit 71.

[0063] As a result, in a situation where the thermal energy of the ammonia gas Ga is taken away and the temperature of the ammonia gas Ga drops, the replacement fluid Fr is automatically heated, making it possible to suppress the temperature drop of the ammonia gas Ga.

[0064] (3) According to a third aspect, the ammonia gas piping equipment 30, 130, 230 is the ammonia gas piping equipment 30, 130, 230 of (2), wherein the temperature acquisition unit 71 acquires a temperature T1 of the replacement fluid Fr at the fluid inlet portion 33 and a temperature T2 of the replacement fluid Fr at the fluid outlet portion 34, and the temperature control unit 73 controls the temperature adjustment unit 35 so that the temperature T2 of the replacement fluid Fr at the fluid outlet portion 34 is equal to or lower than the temperature T1 of the replacement fluid Fr at the fluid inlet portion 33. This makes it possible to suppress an increase in the enthalpy of the replacement fluid Fr due to the flow through the outer space 41. Therefore, it is possible to suppress the thermal energy of the ammonia gas Ga from being transferred to the replacement fluid Fr.

[0065] (4) According to a fourth aspect, the ammonia gas piping equipment 30, 130, 230 is the ammonia gas piping equipment 30, 130, 230 of (3), further comprising a pressure acquisition unit 72 that acquires the pressure of the ammonia gas Ga in the downstream portion of the inner pipe 31, the temperature acquisition unit 71 further acquires the temperature Ta2 of the ammonia gas Ga in the downstream portion, and the temperature control unit 73 controls the temperature adjustment unit 35 based on the pressure Pa2 of the ammonia gas Ga in the downstream portion and the temperature Ta2 of the ammonia gas Ga in the downstream portion so that the temperature Ta2 of the ammonia gas Ga in the downstream portion becomes a superheated steam range. This makes it possible to maintain the state of the ammonia gas Ga flowing through the inner pipe 31 in a superheated vapor state. Therefore, condensation of the ammonia gas Ga flowing through the inner pipe 31 can be further suppressed.

[0066] (5) According to a fifth aspect, the ammonia gas piping equipment 30, 130, 230 is the ammonia gas piping equipment 30, 130, 230 of (2), wherein the temperature acquisition unit 71 acquires a temperature Ta1 of the ammonia gas Ga at the upstream portion of the inner pipe 31 and a temperature Ta2 of the ammonia gas Ga at the downstream portion of the inner pipe 31, and the temperature control unit 73 controls the temperature adjustment unit 35 so that the temperature Ta2 of the ammonia gas Ga at the downstream portion is equal to or higher than the temperature Ta1 of the ammonia gas Ga at the upstream portion. This makes it possible to suppress the thermal energy of the ammonia gas Ga from being transferred to the replacement fluid Fr.

[0067] (6) According to a sixth aspect, the ammonia gas piping equipment 30, 130, 230 is the ammonia gas piping equipment 30, 130, 230 of (5), further comprising a pressure acquisition unit 72 that acquires a pressure Pa2 of the ammonia gas Ga in the downstream portion, and the temperature control unit 73 controls the temperature adjustment unit 35 based on the pressure Pa2 of the ammonia gas Ga in the downstream portion and the temperature Ta2 of the ammonia gas Ga in the downstream portion so that the temperature Ta2 of the ammonia gas Ga in the downstream portion becomes a superheated vapor range. This makes it possible to maintain the state of the ammonia gas Ga flowing through the inner pipe 31 in a superheated vapor state. Therefore, condensation of the ammonia gas Ga flowing through the inner pipe 31 can be further suppressed.

[0068] (7) According to a seventh aspect, the ammonia gas piping equipment 30, 130, 230 is the ammonia gas piping equipment 30, 130, 230 of (2), and further includes a pressure acquisition unit 72 that acquires a pressure Pa2 of the ammonia gas Ga in a downstream portion of the inner pipe 31, the temperature acquisition unit 71 further acquires a temperature Pa2 of the ammonia gas Ga in the downstream portion, and the temperature control unit 73 controls the temperature adjustment unit 35 based on the pressure Pa2 of the ammonia gas Ga in the downstream portion and the temperature Ta2 of the ammonia gas Ga in the downstream portion so that the temperature Ta2 of the ammonia gas Ga in the downstream portion becomes a superheated steam range. As a result, when the ammonia gas Ga in the downstream part of the inner tube 31 is likely to cease to be superheated vapor due to a decrease in temperature Ta2, the replacement fluid Fr can be heated to increase the temperature of the ammonia gas Ga in the downstream part, thereby maintaining the state of superheated vapor, thereby suppressing condensation of the ammonia gas Ga.

[0069] (8) According to an eighth aspect, the ammonia gas piping equipment 30, 130, 230 is any one of the ammonia gas piping equipment 30, 130, 230 of (1) to (7), and the replacement fluid Fr is ventilation air, and further includes a dehumidifier 80 that dehumidifies the ventilation air introduced from the fluid introduction part 33 into the outer space 41. This makes it possible to prevent water that has absorbed the ammonia gas Ga from remaining in the outer space 41 when the ammonia gas Ga leaks.

[0070] (9) According to a ninth aspect, the ammonia gas piping equipment 30, 130, 230 is any one of the ammonia gas piping equipment 30, 130, 230 of (1) to (8), and the replacement fluid Fr is a low dew point gas. This makes it possible to prevent water that has absorbed the ammonia gas Ga from remaining in the outer space 41 when the ammonia gas Ga leaks.

[0071] (10) According to a tenth aspect, the ammonia gas piping equipment 30, 130, 230 is any one of the ammonia gas piping equipment 30, 130, 230 according to (1) to (9), and further includes a heat insulating part 90 for suppressing heat radiation from the outer surface of the outer pipe 32. This makes it possible to keep the replacement fluid Fr flowing through the outer space 41 warm, thereby reducing the energy required to heat the replacement fluid Fr.

[0072] (11) According to an eleventh aspect, the floating body 1 includes any one of the ammonia gas piping facilities 30, 130, 230 of (1) to (10), an ammonia gas supply device 20 that supplies the ammonia gas Ga, and a combustion device 8 that uses the ammonia gas Ga as fuel. Examples of the ammonia gas supply device include various ammonia fuel devices provided in an ammonia fuel conditioning chamber. This makes it possible to prevent the configuration of the floating body 1 from becoming complicated, and to suppress condensation of the ammonia gas Ga serving as fuel.

[0073] (12) According to a twelfth aspect, the control method for an ammonia gas piping system is a control method for any one of the ammonia gas piping systems 30, 130, 230 according to (1) to (10), and includes a step S10 of heating the replacement fluid Fr so that a temperature T2 of the replacement fluid Fr discharged from the inner pipe 31 becomes equal to or lower than a temperature T1 of the replacement fluid Fr introduced into the inner pipe 31. This makes it possible to suppress the thermal energy of the ammonia gas Ga from being transferred to the replacement fluid Fr.

[0074] (13) According to a thirteenth aspect, the control method for an ammonia gas piping system is a control method for any one of the ammonia gas piping systems 30, 130, 230 according to (1) to (10), and includes a step S20 of heating the replacement fluid Fr so that a temperature Ta2 of the ammonia gas Ga in the downstream portion of the inner pipe 31 becomes equal to or higher than a temperature Ta1 of the ammonia gas Ga in the upstream portion of the inner pipe 31. This makes it possible to suppress the thermal energy of the ammonia gas Ga from being transferred to the replacement fluid Fr.

[0075] (14) According to a fourteenth aspect, the control method for ammonia gas piping equipment is a control method for ammonia gas piping equipment 30, 130, 230 of (12) or (13), and includes a step S11 of heating the replacement fluid Fr so that a temperature Ta2 of the ammonia gas Ga in the downstream portion of the inner pipe 31 becomes a superheated vapor region. This makes it possible to maintain the state of the ammonia gas Ga flowing through the inner space 40 of the inner pipe 31 in a superheated vapor state.

[0076] (15) According to a fifteenth aspect, the control method for ammonia gas piping equipment is the control method for ammonia gas piping equipment 30, 130, 230 of (1), and includes a step S31 of heating the replacement fluid Fr so that the temperature Ta2 of the ammonia gas Ga in the downstream portion of the inner pipe 31 becomes a superheated vapor region. As a result, when the ammonia gas Ga in the downstream part of the inner tube 31 is likely to cease to be superheated vapor due to a decrease in temperature Ta2, the replacement fluid Fr can be heated to increase the temperature of the ammonia gas Ga in the downstream part, thereby maintaining the state of superheated vapor, thereby suppressing condensation of the ammonia gas Ga. [Explanation of symbols]

[0077] 1...float 2...float body 3a...bow 3b...stern 4...superstructure 5A, 5B...shipside 6...bottom 7...upper deck 8...combustion device 10...ammonia tank 20...ammonia fuel adjustment room 30, 130, 230...ammonia gas piping equipment 31...inner pipe 32...outer pipe 33...fluid inlet 34...fluid outlet 35...temperature adjustment section 40...inner space 41...outer space 50...sensor 50a...first temperature sensor 50b...second temperature sensor 50c...third temperature sensor 50d...fourth temperature sensor 50e...first pressure sensor 50f...second pressure sensor 51...control device 61...CPU 62...ROM 63...RAM 64...storage 65...signal transmission / reception module 71...temperature acquisition section 72...pressure acquisition section 73...temperature control section 74...command signal output section 80: Dehumidifier 90: Heat-insulating section Fr: Replacement fluid Ga: Ammonia gas

Claims

1. an inner tube forming an inner space through which ammonia gas flows; an outer tube that surrounds the inner tube from an outer periphery side and forms an outer space between the inner tube and the outer tube; a fluid introduction section for introducing a replacement fluid into the outer space to replace the ammonia gas leaked from the inner tube; a fluid discharge portion that is provided apart from the fluid inlet portion in a flow direction of the ammonia gas and discharges the replacement fluid from the outer space; A temperature adjusting unit that heats the replacement fluid before it is introduced into the outer space; Ammonia gas piping equipment equipped with:

2. A control device for controlling the temperature adjustment unit is provided, The control device includes: a temperature acquisition unit that acquires a temperature of at least one of the replacement fluid and the ammonia gas; a temperature control unit that controls the temperature adjustment unit based on the temperature acquired by the temperature acquisition unit. The ammonia gas piping system according to claim 1.

3. The temperature acquisition unit is the temperature of the replacement fluid in the fluid inlet; and and a temperature of the replacement fluid in the fluid discharge portion; The temperature control unit is The temperature adjustment unit is controlled so that the temperature of the replacement fluid in the fluid discharge unit is equal to or lower than the temperature of the replacement fluid in the fluid introduction unit. The ammonia gas piping system according to claim 2.

4. a pressure acquiring unit that acquires a pressure of the ammonia gas at a downstream portion of the inner pipe, The temperature acquisition unit further acquires a temperature of the ammonia gas in the downstream portion, The temperature control unit is The temperature adjusting unit is controlled based on the pressure of the ammonia gas in the downstream portion and the temperature of the ammonia gas in the downstream portion so that the temperature of the ammonia gas in the downstream portion is in a superheated steam range. The ammonia gas piping system according to claim 3.

5. The temperature acquisition unit is the temperature of the ammonia gas at the upstream portion of the inner tube; and a temperature of the ammonia gas at a downstream portion of the inner tube; The temperature control unit is The temperature adjustment unit is controlled so that the temperature of the ammonia gas in the downstream portion is equal to or higher than the temperature of the ammonia gas in the upstream portion. The ammonia gas piping system according to claim 2.

6. a pressure acquiring unit that acquires a pressure of the ammonia gas in the downstream portion, The temperature control unit is The temperature adjusting unit is controlled based on the pressure of the ammonia gas in the downstream portion and the temperature of the ammonia gas in the downstream portion so that the temperature of the ammonia gas in the downstream portion is in a superheated steam range. The ammonia gas piping system according to claim 5.

7. a pressure acquiring unit that acquires a pressure of the ammonia gas at a downstream portion of the inner pipe, The temperature acquisition unit acquires a temperature of the ammonia gas in the downstream portion, The temperature control unit is The temperature adjusting unit is controlled based on the pressure of the ammonia gas in the downstream portion and the temperature of the ammonia gas in the downstream portion so that the temperature of the ammonia gas in the downstream portion is in a superheated steam range. The ammonia gas piping system according to claim 2.

8. The replacement fluid is ventilation air, The ventilation air introduced into the outer space from the fluid introduction portion is further provided with a dehumidifier. The ammonia gas piping facility according to any one of claims 1 to 7.

9. The replacement fluid is a low dew point gas. The ammonia gas piping facility according to any one of claims 1 to 7.

10. The outer tube further includes a heat insulating portion for suppressing heat radiation from the outer surface thereof. The ammonia gas piping facility according to any one of claims 1 to 7.

11. The ammonia gas piping equipment according to any one of claims 1 to 7; an ammonia gas supplying device for supplying the ammonia gas; A combustion device that uses the ammonia gas as fuel; A floating body comprising:

12. The method for controlling an ammonia gas piping facility according to claim 1, a step of heating the replacement fluid so that the temperature of the replacement fluid discharged from the outer space is equal to or lower than the temperature of the replacement fluid introduced into the outer space. A method for controlling ammonia gas piping equipment.

13. The method for controlling an ammonia gas piping facility according to claim 1, a step of heating the replacement fluid so that the temperature of the ammonia gas in the downstream portion of the inner pipe is equal to or higher than the temperature of the ammonia gas in the upstream portion of the inner pipe. A method for controlling ammonia gas piping equipment.

14. a step of heating the replacement fluid so that the temperature of the ammonia gas in the downstream portion of the inner tube is in a superheated vapor region. The method for controlling an ammonia gas piping facility according to claim 12 or 13.

15. The method for controlling an ammonia gas piping facility according to claim 1, a step of heating the replacement fluid so that the temperature of the ammonia gas in the downstream portion of the inner tube is in a superheated vapor region. A method for controlling ammonia gas piping equipment.

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