Ammonia abatement system, floating body, and ammonia abatement method

Abstract

To secure absorbency of ammonia in purging.SOLUTION: An ammonia detoxifying system includes a gas distribution line for distributing purge gas containing ammonia and inert gas, a dilution tank which stores an absorption liquid capable of absorbing the ammonia and can temporarily store the purge gas supplied from the gas distribution line, an outlet line which can send out gas of a gaseous phase in the dilution tank to outside the dilution tank, a detoxifying device which is connected to the outlet line and detoxifies the ammonia contained in the gas sent out through the outlet line, a flow rate control valve provided on the outlet line, and a control device for controlling opening / closing operation of the flow rate control valve, wherein the control device transits the flow rate control valve from a close state to an open state, when ammonia concentration of the gaseous phase in the dilution tank where the purge gas is temporarily stored is lower than a predetermined value.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an ammonia abatement system, a floating body, and an ammonia abatement method. [Background technology]

[0002] In floating bodies such as ships, when ammonia is used as fuel for the main engine, it is expected that the ammonia will be switched between other fuels such as heavy oil. When such a fuel switch is performed or when some kind of trouble occurs in the main engine, it is necessary to discharge the ammonia from the piping of the fuel system by purging the piping with an inert gas such as nitrogen. However, ammonia may have an impact on the surrounding environment, so it is not desirable to release the ammonia discharged from the piping during the purging process directly into the water or atmosphere surrounding the floating body.

[0003] Patent Document 1 discloses an ammonia gas abatement system that detoxifies ammonia gas leaked from a refrigerator unit before it is released into the atmosphere. In this abatement system, the ammonia-containing gas is introduced into a closed space such as a scrubber or cooling tower, and is brought into sufficient contact with water, causing the ammonia component to be absorbed into the water. Patent Document 2 describes an ammonia dilution device that dissolves ammonia gas discharged when purging an ammonia device in dilution water and then treats the water as wastewater. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-026555 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-028431 Summary of the Invention [Problem to be solved by the invention]

[0005] When purging as described above, an inert gas, such as nitrogen, introduced for purging is discharged from the piping along with ammonia. For example, if this inert gas is nitrogen, nitrogen is not easily absorbed by water. Therefore, in the abatement systems and ammonia dilution devices described in Patent Documents 1 and 2, the inert gas discharged from the piping is hardly absorbed by water that absorbs ammonia components in enclosed spaces such as scrubbers and cooling towers, and in the dilution tank, and is instead released to the outside. Because the flow rate of the inert gas during such purging is high, this large amount of inert gas flowing in may reduce the absorbability of ammonia components in enclosed spaces and the dilution tank.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an ammonia detoxification system, a float, and an ammonia detoxification method that can ensure ammonia absorbency during purging. [Means for solving the problem]

[0007] In order to solve the above problems, the ammonia detoxification system according to the present disclosure includes a gas distribution line through which a purge gas containing ammonia and an inert gas flows; The method includes: a detoxification device that detoxifies the ammonia; and a dilution tank, a delivery line, and a flow rate control valve that are provided between the gas distribution line and the detoxification device and that perform batch processing. The dilution tank includes: an absorption liquid capable of absorbing the ammonia is stored, and the purge gas supplied from the gas distribution line is capable of being temporarily stored; The delivery line is The gas in the gas phase in the dilution tank The flow rate control valve is configured to be capable of sending the gas to the abatement device. The delivery line is provided with And, The apparatus further includes a control device that controls the opening and closing operation of the flow control valve, and the control device transitions the flow control valve from a closed state to an open state when the ammonia concentration in the gas phase in the dilution tank in which the purge gas is temporarily stored falls below a predetermined value.

[0008] The float according to the present disclosure comprises a float body and the above-described ammonia abatement system.

[0009] The ammonia detoxification method in the ammonia detoxification system according to the present disclosure includes the steps of introducing a purge gas, absorbing ammonia with an absorption liquid, and sending the gas from the gas phase in a dilution tank to a detoxification device. In the step of introducing the purge gas, the purge gas is introduced into the dilution tank from the gas distribution line. In the step of absorbing ammonia with an absorption liquid, the purge gas introduced into the dilution tank is temporarily stored in the dilution tank. In the step of absorbing ammonia with an absorption liquid, the ammonia contained in the purge gas is absorbed by the absorption liquid. In the step of sending the gas from the gas phase in the dilution tank to the detoxification device, when the ammonia concentration in the gas phase in the dilution tank falls below a predetermined value, the flow control valve is switched from a closed state to an open state, and the gas is sent from the gas phase in the dilution tank to the detoxification device through the delivery line. [Effects of the Invention]

[0010] According to the ammonia abatement system, float, and ammonia abatement method of the present disclosure, it is possible to ensure ammonia absorption during purging. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a side view of a floating body equipped with an ammonia abatement system, a floating body, and an ammonia abatement method according to an embodiment of the present disclosure. FIG. [Figure 2] 1 is a diagram illustrating a configuration of an ammonia detoxification system according to an embodiment of the present disclosure. [Figure 3] FIG. 2 is a diagram illustrating a hardware configuration of a control device of an ammonia detoxification system according to an embodiment of the present disclosure. [Figure 4] FIG. 2 is a functional block diagram of a control device according to an embodiment of the present disclosure. [Figure 5] 1 is a flowchart of an ammonia abatement method according to an embodiment of the present disclosure. [Figure 6] FIG. 10 illustrates a process for introducing a purge gas according to an embodiment of the present disclosure. [Figure 7]10A-10C illustrate a process for terminating the introduction of purge gas according to an embodiment of the present disclosure. [Figure 8] FIG. 1 illustrates a process for transferring a gas phase according to an embodiment of the present disclosure. [Figure 9] FIG. 1 is a diagram showing the configuration of an ammonia detoxification system according to a first modified example of an embodiment of the present disclosure. [Figure 10] 1 is a flowchart of an ammonia detoxification method according to a first modified example of an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an ammonia detoxification system, a floating body, and an ammonia detoxification method according to an embodiment of the present disclosure will be described with reference to FIGS.

[0013] (Overall structure of the floating body) As shown in FIG. 1 , a float 1 according to an embodiment of the present disclosure includes a float main body 2, a superstructure 4, a combustion device 8, and an ammonia abatement system 100. The float 1 according to this embodiment will be described as a ship capable of navigation using a main engine or the like. The type of ship that the float 1 is used for is not limited to a specific type of ship. Examples of ship types that the float 1 can be used for include a liquefied gas carrier, a ferry, a roll-on / roll-off ship, a car carrier, and a passenger ship. While this embodiment describes a case where the float 1 is a ship, the float 1 is not limited to a ship and may also be an FSU (Floating Storage Unit), FSRU (Floating Storage and Regasification Unit), or the like that is not capable of navigation using a main engine or the like.

[0014] The floating body 2 is formed so as to float on seawater. The floating body 2 has a pair of side panels 5A, 5B and a bottom 6 that form its outer hull. The side panels 5A, 5B are provided with a pair of side shell plates that form the port and starboard sides, respectively. The bottom 6 is provided with a bottom shell plate that connects the side panels 5A, 5B. The pair of side panels 5A, 5B and the bottom 6 give the outer hull of the floating body 2 a U-shape in a cross section perpendicular to the bow-stern direction FA.

[0015] The floating body main body 2 further comprises an upper deck 7, which is a full-length deck located at the topmost level. The superstructure 4 is formed on this upper deck 7. Accommodation areas and the like are provided within the superstructure 4. In the floating body 1 of this embodiment, for example, a cargo space (not shown) for carrying cargo is provided closer to the bow 2a in the bow-stern direction FA than the superstructure 4.

[0016] The combustion device 8 is a device that generates thermal energy by burning fuel, and is provided inside the floating body main body 2. Examples of the combustion device 8 include an internal combustion engine used as the main engine for propelling the floating body 1, an internal combustion engine used in a power generation facility that supplies electricity on board, and a boiler that generates steam as a working fluid. The combustion device 8 used as the main engine in the floating body 1 of this embodiment is capable of switching between ammonia and other fuels different from ammonia, such as heavy oil, as fuel. A fuel system (not shown) that supplies fuel is connected to the combustion device 8. Ammonia and other fuels circulate through the fuel system.

[0017] When switching the fuel for the combustion device 8 from ammonia to another fuel or when performing maintenance, ammonia remaining in a piping system including the fuel system of the combustion device 8 is replaced with an inert gas (purge gas) such as nitrogen, a process known as purging. Here, the ammonia remaining in the piping system may be liquefied ammonia or ammonia gas. To perform purging, an inert gas supply device (not shown) is connected to the piping system. The inert gas supply device is capable of supplying an inert gas to the piping system. Note that the inert gas may be any gas that does not chemically react when in contact with ammonia, and an example of such a gas is nitrogen. When the inert gas supply device supplies an inert gas from an inert gas supply source (not shown) to the piping system, the ammonia in the piping system is pushed out by the inert gas. As a result, a purge gas containing ammonia (liquefied ammonia, ammonia gas) and the inert gas is discharged from the piping system.

[0018] (Configuration of ammonia abatement system) FIG. 2 is a diagram showing the configuration of an ammonia detoxification system according to an embodiment of the present disclosure. 2, the ammonia detoxification system 100 includes at least a gas distribution line 10, a dilution tank 20, a delivery line 30, and a detoxification device 40. When ammonia in a piping system is purged, the ammonia detoxification system 100 detoxifies the ammonia contained in the purge gas discharged from the piping system.

[0019] The gas distribution line 10 forms a flow path for circulating the purge gas discharged from the piping system of the combustion device 8 (see FIG. 1) during purging. The gas distribution line 10 guides the circulating purge gas to the ammonia abatement system 100. The purge gas flowing through the gas distribution line 10 contains ammonia and an inert gas.

[0020] An on-off valve 15 is provided in the gas distribution line 10. The on-off valve 15 is capable of opening and closing the flow path in the gas distribution line 10. The on-off valve 15 has its opening and closing operation controlled by a control device 60, which will be described later.

[0021] The dilution tank 20 has a hollow structure and stores therein an absorption liquid L capable of absorbing ammonia. The dilution tank 20 may be a pressure vessel. A plurality of dilution tanks 20 may be provided. Fresh water or seawater is supplied to the dilution tank 20 from the outside as the absorption liquid L through a water intake pipe (not shown). As a result, a liquid in a liquid phase containing the absorption liquid L is stored in the lower part of the dilution tank 20. A gas in a gas phase is stored above the liquid phase in the dilution tank 20. A purge gas is introduced into the dilution tank 20 through the gas distribution line 10. The ammonia component contained in the purge gas introduced into the dilution tank 20 is absorbed by the absorption liquid L. As a result, the liquid in the liquid phase in the dilution tank 20 contains the absorption liquid L and the ammonia component.

[0022] The dilution tank 20 is provided with an absorption promoter 22. The absorption promoter 22 promotes the absorption of ammonia by the absorption liquid L in the dilution tank 20. The absorption promoter 22 in this embodiment includes a circulation line 23, a spray 24, and a circulation pump 25. One end of the circulation line 23 is connected to the lower part of the dilution tank 20. The other end of the circulation line 23 is disposed in the gas phase in the upper part of the dilution tank 20. The spray 24 is provided at the other end of the circulation line 23 in the dilution tank 20. The circulation pump 25 is provided midway along the circulation line 23. The circulation pump 25 draws the liquid phase in the dilution tank 20 into the circulation line 23 and circulates it to the gas phase in the upper part of the dilution tank 20. The liquid phase drawn into the circulation line 23 is sprayed into the gas phase in the upper part of the dilution tank 20 through the spray 24. As a result, the absorption liquid L contained in the liquid phase comes into contact with ammonia in the gas phase in the dilution tank 20, promoting the absorption of ammonia.

[0023] For example, a pressure sensor 27p is provided inside the dilution tank 20. The pressure sensor 27p detects the pressure of the gas phase inside the dilution tank 20. The pressure sensor 27p outputs the detection data to the control device 60, which will be described later.

[0024] The delivery line 30 is capable of delivering the gas phase gas in the dilution tank 20 to the outside of the dilution tank 20. One end of the delivery line 30 is connected to the upper part of the dilution tank 20. The other end of the delivery line 30 is connected to the detoxification device 40. The delivery line 30 is capable of delivering the gas phase gas in the dilution tank 20 to the detoxification device 40.

[0025] A flow rate adjustment valve 35 is provided in the delivery line 30. The flow rate adjustment valve 35 is capable of adjusting the flow rate of the gas flowing through the flow path in the delivery line 30. The operation of the flow rate adjustment valve 35 is controlled by a control device 60.

[0026] A flow rate sensor 27f is provided in the delivery line 30. The flow rate sensor 27f detects the flow rate of the gas delivered from the dilution tank 20 through the delivery line 30. The flow rate sensor 27f outputs the detection data to the control device 60.

[0027] The abatement device 40 is connected to the delivery line 30. The abatement device 40 abats the ammonia contained in the gas delivered through the delivery line 30 to a standard value or less. The abatement device 40 is, for example, an absorption tower 41. The absorption tower 41 absorbs the ammonia contained in the gas delivered through the delivery line 30 into an absorbing liquid. The absorption tower 41 includes a tower body 41a and a nozzle (not shown) that sprays the absorbing liquid from the upper part of the tower body 41a. The other end of the delivery line 30 is connected to the lower part of the tower body 41a. The gas delivered from the dilution tank 20 is sent into the tower body 41a through the delivery line 30. The absorption tower 41, for example, drops fresh water or seawater as an absorbing liquid from a nozzle in the tower body 41a and brings the liquid into contact with the gas introduced into the absorption tower 41, thereby absorbing the ammonia contained in the gas into the absorbing liquid.

[0028] The abatement device 40 is not limited to the absorption tower 41, but may also be, for example, a dilution fan, a GCU (Gas Combustion Unit), a catalytic combustion device, etc. The dilution fan reduces the ammonia concentration in the gas by mixing outside air taken in from the outside with the gas discharged from the dilution tank 20 through the discharge line 30. The GCU (Gas Combustion Unit) and catalytic combustion device reduce the ammonia concentration in the gas by burning the ammonia contained in the gas.

[0029] An exhaust line 50 is connected to the abatement device 40. The exhaust line 50 discharges the gas from which ammonia has been abattoidized by the abatement device 40 into the atmosphere. As the exhaust line 50, for example, a vent post provided on the upper deck 7 of the floating body main body 2, a funnel 9 (see FIG. 1), or the like can be used.

[0030] The control device 60 controls the opening and closing operation of the flow rate control valve 35. In this embodiment, the control device 60 also controls the opening and closing operation of the on-off valve 15. By controlling the operation of the on-off valve 15 and the flow rate control valve 35, the control device 60 temporarily stores the purge gas in the dilution tank 20 until the gas phase and the liquid phase in the dilution tank 20 reach gas-liquid equilibrium, thereby performing so-called batch processing. When the ammonia concentration in the gas phase in the dilution tank 20 falls below a predetermined value, the control device 60 transitions the flow rate control valve 35 from a closed state to an open state. In this embodiment, when the gas phase and the liquid phase in the dilution tank 20 reach gas-liquid equilibrium, the control device 60 delivers the gas in the dilution tank 20 from the dilution tank 20 to the abatement device 40. The predetermined value is an ammonia concentration higher than the ammonia concentration when gas-liquid equilibrium is reached, and when it is estimated that gas-liquid equilibrium is reached, the ammonia concentration in the gas phase in the dilution tank 20 is below the predetermined value. The specified value can be, for example, an ammonia concentration that is slightly higher than the ammonia concentration in the gas-liquid equilibrium state. Generally, the gas-liquid equilibrium state is a state in which mass transfer between the gas phase and the liquid phase has completely ceased. However, strictly speaking, since the temperature is constantly changing, even if only slightly, mass transfer is always occurring. In this embodiment, for example, when the pressure of the gas phase falls within a predetermined range from the saturated vapor pressure (for example, within a range of saturated vapor pressure + 20%), it is considered to be a gas-liquid equilibrium state.

[0031] (Hardware configuration diagram) FIG. 3 is a diagram illustrating a hardware configuration of a control device according to an embodiment of the present disclosure. 3, the control device is a computer including a CPU 61 (Central Processing Unit), a ROM 62 (Read Only Memory), a RAM 63 (Random Access Memory), a storage 64, and a signal transmission / reception module 65. The signal transmission / reception module 65 receives detection signals from the pressure sensor 27p and the flow rate sensor 27f.

[0032] (Function block diagram) FIG. 4 is a functional block diagram of a control device according to an embodiment of the present disclosure. As shown in FIG. 4, the CPU 61 of the control device 60 executes a program pre-stored in a storage device such as a ROM 62 or a storage 64, thereby realizing the components of a signal input unit 70, an information acquisition unit 71, a valve control unit 72, and an output unit 75. The signal input unit 70 receives detection signals from the pressure sensor 27p and the flow rate sensor 27f via a signal transmission / reception module 65, which is hardware.

[0033] When purge gas is being introduced into the dilution tank 20, the information acquiring unit 71 acquires detection data of the pressure inside the dilution tank 20 detected by the pressure sensor 27p based on the signal received by the signal input unit 70. Furthermore, when gas in the gas phase of the dilution tank 20 is being sent out through the delivery line 30, the information acquiring unit 71 acquires detection data of the flow rate of the gas inside the delivery line 30 detected by the flow rate sensor 27f based on the signal received by the signal input unit 70.

[0034] The valve control unit 72 closes the flow rate control valve 35 when purge gas is introduced into the dilution tank 20 from the gas distribution line 10. The valve control unit 72 controls the operation of the flow rate control valve 35 based on detection data of the pressure inside the dilution tank 20 and detection data of the gas flow rate in the delivery line 30, both acquired by the information acquisition unit 71. Specifically, the valve control unit 72 determines whether the gas and liquid phases inside the dilution tank 20 have reached gas-liquid equilibrium based on the amount of change in pressure inside the dilution tank 20 detected by the pressure sensor 27p. If it is determined that the gas and liquid phases inside the dilution tank 20 have reached gas-liquid equilibrium, the valve control unit 72 transitions the flow rate control valve 35 from a closed state to an open state. Furthermore, the valve control unit 72 reduces the aperture of the flow rate control valve 35 when the gas flow rate detected by the flow rate sensor 27f exceeds a reference flow rate.

[0035] Furthermore, the valve control unit 72 opens the on-off valve 15 when the purge gas is introduced into the dilution tank 20 from the gas distribution line 10. The valve control unit 72 closes the on-off valve 15 when the gas is delivered from the gas phase in the dilution tank 20 to the outside through the delivery line 30. The valve control unit 72 outputs command signals for switching the open / close states of the on-off valve 15 and the flow rate adjustment valve 35 . The output unit 75 outputs the command signal output from the valve control unit 72 to the on-off valve 15 and the flow rate adjustment valve 35 .

[0036] (Ammonia detoxification method) Next, a method for detoxifying ammonia from a floating body according to an embodiment of the present disclosure will be described with reference to the drawings. Figure 5 is a flowchart of an ammonia detoxification method according to an embodiment of the present disclosure. Figure 6 is a diagram illustrating a process of introducing a purge gas according to an embodiment of the present disclosure. Figure 7 is a diagram illustrating a process of terminating the introduction of a purge gas according to an embodiment of the present disclosure.

[0037] As shown in FIG. 5, the ammonia detoxification method S10 of this embodiment includes a step S11 of introducing a purge gas, a step S12 of determining the end of purging, a step S13 of terminating the introduction of the purge gas, a step S14 of absorbing ammonia, a step S15 of determining whether or not a gas-liquid equilibrium state has been reached, a step S16 of feeding gas in the gas phase into the detoxification device, a step S17 of determining whether or not the flow rate has exceeded a reference flow rate, a step S18 of reducing the flow rate of the gas, and a step S19 of terminating the ammonia detoxification treatment.

[0038] Prior to carrying out the ammonia detoxification method S10, in the ammonia detoxification system 100, the absorbing liquid L is stored in advance in the dilution tank 20. The absorbing liquid L is obtained by taking in fresh water or seawater from outside the dilution tank 20 through a water intake pipe (not shown). In addition, the on-off valve 15 and the flow rate adjusting valve 35 are kept closed.

[0039] In the step S11 of introducing a purge gas, when an inert gas is fed into the piping system to perform purging, a purge gas containing ammonia and an inert gas is introduced into the dilution tank 20. To do this, as shown in Fig. 6, the on-off valve 15 of the gas distribution line 10 is opened under the control of the valve control unit 72 (see Fig. 4) of the control device 60. Then, the purge gas is introduced into the dilution tank 20 through the gas distribution line 10.

[0040] In step S12 of determining whether or not the purge has been completed, the control device 60 determines whether or not the supply of the inert gas that has been carried out for purging the piping system has been completed. As a result, if it is determined that the supply of the inert gas has not been completed and the purging has not been completed ("No" in step S12), the state of step S11 continues. On the other hand, if it is determined that the supply of the inert gas has finished and the purging has finished ("Yes" in step S12), the process proceeds to step S13.

[0041] In step S13 of terminating the introduction of the purge gas, once the supply of the inert gas to the piping system has been completed, the on-off valve 15 is closed as shown in Fig. 7. As a result, the inside of the dilution tank 20 to which the purge gas has been supplied becomes a closed space between the on-off valve 15 and the flow rate control valve 35, both of which are in a closed state.

[0042] In step S14 of absorbing ammonia, the ammonia contained in the purge gas introduced into dilution tank 20 is absorbed into absorption liquid L. At this time, in absorption promotion section 22, circulation pump 25 is operated to suck the liquid in the liquid phase in dilution tank 20 into circulation line 23, and the liquid is sprayed from spray 24 into the gas phase in the upper part of dilution tank 20. As a result, absorption liquid L contained in the liquid phase comes into contact with ammonia in the gas phase in dilution tank 20, and absorption of ammonia is promoted. Note that step S14 may be performed in parallel with steps S11 to S13.

[0043] In step S15, which determines whether or not a gas-liquid equilibrium state has been reached, the pressure sensor 27p detects the gas phase pressure in the dilution tank 20 at preset unit time intervals while step S14 is in progress. The gas phase pressure data detected by the pressure sensor 27p is output to the control device 60. The valve control unit 72 of the control device 60 determines whether or not the gas phase and liquid phase in the dilution tank 20 have reached a gas-liquid equilibrium state. In this embodiment, when the valve control unit 72 of the control device 60 acquires data on the gas phase pressure detected by the pressure sensor 27p two or more times, it determines whether or not the amount of change in these pressures per unit time is less than a preset threshold value. If the result of this determination is that the amount of change per unit time in the gas phase pressure in the dilution tank 20 detected by the pressure sensor 27p is equal to or greater than the threshold value ("No" in step S15), step S14 continues as is.

[0044] On the other hand, if the amount of change per unit time in the gas phase pressure in the dilution tank 20 detected by the pressure sensor 27p is less than the threshold value ("Yes" in step S15), the process proceeds to step S16. If the amount of change per unit time in the gas phase pressure in the dilution tank 20 detected by the pressure sensor 27p is less than the threshold value, it can be estimated that the absorption of ammonia into the absorption liquid L has reached a saturated state. In other words, if the amount of change per unit time in the gas phase pressure in the dilution tank 20 detected by the pressure sensor 27p is less than the threshold value, it can be determined that the gas phase and liquid phase in the dilution tank 20 have reached a gas-liquid equilibrium state.

[0045] FIG. 8 illustrates a process for transferring a gas phase according to an embodiment of the present disclosure. In step S16 of sending the gas phase gas to the detoxification device, the flow rate adjustment valve 35 is opened under the control of the valve control unit 72 (see FIG. 4) of the control device 60, as shown in FIG. 8. Then, the gas phase gas in the dilution tank 20 is sent to the detoxification device 40 through the delivery line 30. The gas sent to the detoxification device 40 undergoes a predetermined detoxification process in the detoxification device 40, and the ammonia contained in the gas is removed. The gas from which the ammonia has been removed by the detoxification device 40 is discharged into the atmosphere through an exhaust line 50.

[0046] In this step S16, when the flow rate adjustment valve 35 is in an open state, the flow rate of the gas being sent to the abatement device 40 through the delivery line 30 is detected by the flow rate sensor 27f at preset unit time intervals. The data of the gas flow rate detected by the flow rate sensor 27f is output to the control device 60.

[0047] In step S17 for determining whether the flow rate of the gas detected by the flow sensor 27f has exceeded the reference flow rate, the valve control unit 72 determines whether the flow rate of the gas detected in the delivery line 30 is equal to or less than the reference flow rate (step S17: No), the flow rate is not adjusted by the flow control valve 35 and the gas continues to be sent to the detoxification device 40. On the other hand, if the detected flow rate of the gas in the delivery line 30 has exceeded the reference flow rate (step S17: Yes), the process proceeds to step S18.

[0048] In step S18 of reducing the gas flow rate, the valve control unit 72 reduces the opening of the flow rate adjustment valve 35 to make the gas flow rate in the delivery line 30 equal to or less than the reference flow rate. As a result, the gas in the gas phase is sent from the dilution tank 20 to the detoxification device 40 at a flow rate equal to or less than the reference flow rate.

[0049] In step S19 of terminating the ammonia detoxification treatment, the ammonia detoxification treatment is terminated in the ammonia detoxification system 100 when a predetermined termination condition is satisfied. Examples of conditions for terminating the ammonia detoxification treatment include the pressure inside the dilution tank 20 decreasing below a predetermined lower limit, the flow rate of the gas detected by the flow sensor 27f decreasing below a predetermined lower limit, or the time elapsed since the introduction of the purge gas was terminated in step S13 reaching a predetermined reference time.

[0050] (Action and effect) In the ammonia detoxification system 100, the floating body 1, and the ammonia detoxification method S10 of the above embodiment, when purging a pipe or the like through which ammonia flows with an inert gas, a purge gas containing ammonia and an inert gas is supplied to the dilution tank 20. The purge gas supplied to the dilution tank 20 is temporarily stored in the dilution tank 20. Furthermore, an absorption liquid L is stored in the dilution tank 20, and the ammonia contained in the purge gas temporarily stored in the dilution tank 20 is absorbed by the absorption liquid L. This allows the ammonia concentration in the gas phase in the dilution tank 20 to decrease over time. When the ammonia concentration in the gas phase in the dilution tank 20 falls below a specified value, the control device 60 transitions the flow rate adjustment valve 35 from a closed state to an open state, and the gas in the gas phase in the dilution tank 20 is sent through the delivery line 30 to the detoxification device 40 outside the dilution tank 20.

[0051] In this way, by temporarily storing in the dilution tank 20 the purge gas that flows in in large quantities through the gas distribution line 10 during purging, the process of absorbing the ammonia contained in the purge gas can be performed in the dilution tank 20 as a so-called batch process rather than a continuous process, and therefore the ammonia concentration in the gas phase of the dilution tank 20 can be sufficiently reduced without using a mixer or the like. In addition, the purge gas that flows in in large quantities through the gas distribution line 10 can be prevented from suddenly flowing into the detoxification device 40.

[0052] Furthermore, since a large amount of gas is not continuously sent from the dilution tank 20 to the detoxification device 40, there is no need for the detoxification device 40 to treat a large amount of ammonia in a short period of time, and the detoxification device 40 can be made smaller. Also, for example, a device that takes time to start up when detoxifying ammonia can be used as the detoxification device 40. Furthermore, if the detoxification device 40 is an absorption tower (scrubber), it is possible to prevent the occurrence of so-called flooding, in which water sprayed downward in the absorption tower flows back upward due to the inflow of a large amount of inert gas.

[0053] In the above embodiment, when the gas phase and the liquid phase in the dilution tank 20 reach a gas-liquid equilibrium state, the control device 60 transitions the flow rate adjustment valve 35 from the closed state to the open state. This allows the diluted solution in the dilution tank 20 to absorb the maximum amount of ammonia contained in the purge gas temporarily stored in the dilution tank 20. Therefore, gas in a gas phase with a sufficiently reduced ammonia concentration can be sent from the dilution tank 20 to the detoxification device 40.

[0054] In the above embodiment, the control device 60 determines whether or not the gas phase and the liquid phase in the dilution tank 20 have reached a gas-liquid equilibrium state based on the amount of change in pressure in the dilution tank 20 detected by the pressure sensor 27p. This makes it possible to easily determine whether or not the gas-liquid equilibrium state has been reached.

[0055] In the above embodiment, when the flow rate of the gas detected by the flow rate sensor 27f exceeds the reference flow rate, the opening degree of the flow rate adjustment valve 35 is reduced. This makes it possible to prevent the flow rate of the gas sent to the detoxification device 40 from becoming excessive, regardless of the pressure level of the gas phase in the dilution tank 20. Therefore, it is possible to prevent the flow of gas at an excessive flow rate that exceeds the processing capacity of the detoxification device 40.

[0056] In the above embodiment, when the purge gas is introduced into the dilution tank 20 from the gas distribution line 10, the flow rate adjustment valve 35 is in a closed state. This prevents the purge gas introduced into the dilution tank 20 from being sent to the detoxification device 40 without being sufficiently diluted. Furthermore, the ammonia contained in the purge gas can be batch-treated in the dilution tank 20, and the ammonia concentration in the gas phase of the dilution tank 20 can be sufficiently reduced.

[0057] In the above embodiment, when the gas is delivered from the gas phase in the dilution tank 20 to the outside through the delivery line 30, the on-off valve 15 that opens and closes the gas distribution line 10 is closed. This prevents the gas phase gas temporarily stored in the dilution tank 20 from flowing back through the gas distribution line 10.

[0058] When the dilution tank 20 of the above embodiment is formed of a pressure vessel, the purge gas can be stored at an elevated pressure when it is temporarily stored in the dilution tank 20. This allows the dilution tank 20 to be made smaller, which contributes to the miniaturization of the ammonia detoxification system 100 as a whole.

[0059] (First Modification of the Embodiment) Next, a first modified example of the embodiment of the present disclosure will be described with reference to the drawings. This first modified example differs from the above-described embodiment only in that it includes a bypass line 10a. Therefore, the same parts as those in the above-described embodiment will be denoted by the same reference numerals and will not be described again. Fig. 9 is a diagram showing the configuration of an ammonia detoxification system according to a first modified example of the embodiment of the present disclosure, and Fig. 10 is a flowchart of an ammonia detoxification method according to the first modified example of the embodiment of the present disclosure.

[0060] The floating body 1 of this first modified example includes a floating body main body 2, an upper structure 4, a combustion device 8, and an ammonia detoxification system 100. As shown in FIG. 9, the ammonia detoxification system 100 includes a gas distribution line 10, a dilution tank 20, a delivery line 30, a detoxification device 40, and a bypass line 10a.

[0061] The bypass line 10a branches off from the gas distribution line 10 on the side closer to the combustion device 8 (see FIG. 1 ) than the on-off valve 15 (in other words, the upstream side), and is connected to merge with the delivery line 30 on the side closer to the abatement device 40 than the flow rate control valve 35 (in other words, the downstream side). The bypass line 10a is provided with a valve 15a midway. The flow path in the bypass line 10a can be opened and closed by opening and closing the valve 15a. The valve 15a is normally closed and is opened only when necessary.

[0062] 10, the ammonia detoxification method S10 of this first modification includes the steps of introducing a purge gas S11, determining the end of the purge S12, terminating the introduction of the purge gas S13, releasing the residual pressure in the gas supply line S21, absorbing ammonia S14, determining whether a gas-liquid equilibrium state is reached S15, sending the gas phase gas to the detoxification device S16, determining whether the flow rate exceeds a reference flow rate S17, reducing the flow rate of the gas S18, and terminating the ammonia detoxification process S19. Note that steps S10 to S13 and S14 to S19 are the same as those in the first embodiment described above, and therefore detailed description thereof will be omitted.

[0063] In step S21 of releasing the residual pressure in the gas supply line, the residual pressure in the gas distribution line 10 is released after step S13 of terminating the introduction of the purge gas. Here, the above-mentioned gas distribution line 10 becomes a line with pressure due to the back pressure of the dilution tank 20. Therefore, in order to release the pressure in the gas distribution line 10, after step S13 of terminating the introduction of the purge gas, the valve control unit 72 of the control device 60 opens the valve 15a while the on-off valve 15 and the flow rate control valve 35 are closed. With this configuration, the residual pressure in the gas distribution line 10 can be released to the detoxification device 40 via the bypass line 10 a and the delivery line 30 .

[0064] (Other embodiments) The above describes in detail the embodiments of the present disclosure with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present disclosure. In the above embodiment, the control device 60 determines whether the gas phase and the liquid phase in the dilution tank 20 have reached gas-liquid equilibrium based on the amount of change in pressure in the dilution tank 20 detected by the pressure sensor 27p, but this is not limited to this. 4, a concentration sensor 27c may be provided that detects the ammonia concentration in at least one of the gas phase and the liquid phase in the dilution tank 20. In this case, in step S15, the control device 60 determines whether or not the gas phase and the liquid phase in the dilution tank 20 have reached a gas-liquid equilibrium state, based on the ammonia concentration detected by the concentration sensor 27c.

[0065] When the ammonia concentration detected by concentration sensor 27c is used as a criterion for determining whether or not gas-liquid equilibrium has been achieved, transitioning flow control valve 35 from a closed state to an open state after gas-liquid equilibrium has been achieved prevents gas with an excessively high ammonia concentration from being sent to detoxification device 40. Therefore, the load on detoxification device 40 that detoxifies ammonia can be prevented from becoming excessively high.

[0066] As shown in FIG. 4, a temperature sensor 27t for detecting the temperature of the gas phase in the dilution tank 20 may be provided. When ammonia contained in the purge gas is absorbed by the treatment liquid in the dilution tank 20, the heat of reaction increases the temperatures of the gas and liquid in the dilution tank 20. Some detoxification devices 40 do not allow high-temperature gas to be fed into them. Therefore, the control device 60 may prohibit control of the flow control valve 35 from transitioning from the closed state to the open state unless the gas-liquid temperature detected by the temperature sensor 27t is below a reference temperature. Specifically, even if it is determined in step S16 shown in FIG. 5 that the gas and liquid phases in the dilution tank 20 have reached a gas-liquid equilibrium state, so-called interlock control may be performed to prevent the flow control valve 35 from transitioning from the closed state to the open state unless the gas-liquid temperature detected by the temperature sensor 27t is below the reference temperature. This prevents excessively high-temperature gas from being fed into the detoxification device 40. As a result, the detoxification function of the detoxification device 40 can be fully utilized.

[0067] Furthermore, in the above embodiment, when the gas phase and the liquid phase in the dilution tank 20 reach a gas-liquid equilibrium state, the gas in the gas phase in the dilution tank 20 is sent from the dilution tank 20 to the abatement device 40. However, this is not limited to when complete gas-liquid equilibrium is reached, and for example, the control device 60 may transition the flow rate adjustment valve 35 from a closed state to an open state when the ammonia concentration in the gas phase in the dilution tank 20 falls below a preset value that can be estimated to be close to a gas-liquid equilibrium state.

[0068] In addition, in the above embodiment, the opening and closing operation of the on-off valve 15 is controlled by the control device 60, but the on-off valve 15 may also be opened and closed by an operator at the start and end of purging.

[0069] Furthermore, in the above embodiment, the absorption liquid L is sprayed from a nozzle provided in the upper part of the dilution tank 20, but this is not limiting. For example, when a purge gas is supplied into the dilution tank 20 through the gas distribution line 10, the purge gas may be supplied into the liquid phase in the dilution tank 20.

[0070] The order of the steps in the ammonia detoxification method described in the above embodiment can be changed as appropriate. Also, a plurality of steps may be performed in parallel.

[0071] In the above embodiment, an example was given in which so-called interlock control is performed, in which control to transition the flow rate control valve 35 from a closed state to an open state is prohibited when the gas phase temperature in the dilution tank 20 detected by the temperature sensor 27t is not below the reference temperature. However, the present invention is not limited to the case in which only interlock control is performed. For example, a heat exchanger may be provided in the circulation line 23 to remove the heat of reaction. This prevents gas with an excessively high temperature from being sent to the detoxification device 40. As a result, the detoxification function of the detoxification device 40 can be fully exerted.

[0072] <Additional Notes> The ammonia detoxification system 100, the floating body, and the ammonia detoxification method described in the embodiment can be understood, for example, as follows.

[0073] (1) An ammonia detoxification system 100 according to a first aspect includes a gas distribution line 10 through which a purge gas containing ammonia and an inert gas flows, a dilution tank 20 in which an absorption liquid L capable of absorbing the ammonia is stored and which can temporarily store the purge gas supplied from the gas distribution line 10, a delivery line 30 which can deliver gas in the gas phase in the dilution tank 20 to the outside of the dilution tank 20, a detoxification device 40 connected to the delivery line 30 and which detoxifies the ammonia contained in the gas delivered through the delivery line 30, a flow control valve 35 provided on the delivery line 30, and a control device 60 which controls the opening and closing operation of the flow control valve 35, and the control device 60 transitions the flow control valve 35 from a closed state to an open state when the ammonia concentration in the gas phase in the dilution tank 20 in which the purge gas is temporarily stored falls below a predetermined value. Examples of the abatement device 40 include an absorption tower, a dilution fan, a GCU, and a catalytic combustion device. An example of the inert gas is nitrogen. Examples of the absorption liquid L include fresh water and seawater.

[0074] In this ammonia abatement system 100, when purging a pipe or the like through which ammonia flows with an inert gas, the inert gas is sent into the pipe or the like, and a purge gas containing ammonia and the inert gas is supplied to the dilution tank 20 through the gas distribution line 10. At this time, the flow rate control valve 35 provided in the delivery line 30 is closed, so the purge gas in the dilution tank 20 is not sent out of the dilution tank 20 via the delivery line 30, and the purge gas supplied from the gas distribution line 10 is temporarily stored in the dilution tank 20. Since the dilution tank 20 stores the absorption liquid L, the ammonia contained in the purge gas temporarily stored in the dilution tank 20 is absorbed by the absorption liquid L. As a result, the ammonia concentration in the gas phase in the dilution tank 20 decreases over time. When the ammonia concentration in the gas phase in the dilution tank 20 falls below a specified value, the control device 60 transitions the flow rate control valve 35 from a closed state to an open state. Then, the gas in the gas phase inside the dilution tank 20 is sent through the delivery line 30 to the detoxification device 40 outside the dilution tank 20. In the detoxification device 40, ammonia contained in the sent gas is detoxified. In this way, by temporarily storing in the dilution tank 20 the purge gas that flows in large quantities through the gas distribution line 10 during purging, the ammonia contained in the purge gas is absorbed by the absorption liquid L in the dilution tank 20, and the ammonia concentration in the gas phase in the dilution tank 20 decreases over time, making it possible to sufficiently reduce the ammonia concentration in the gas phase. Furthermore, since the process of absorbing ammonia contained in the purge gas in the dilution tank 20 can be performed not continuously but as a so-called batch process, the ammonia concentration in the gas phase of the dilution tank 20 can be sufficiently reduced without using a mixer or the like. In addition, the purge gas flowing in large quantities through the gas distribution line 10 can be prevented from suddenly flowing into the detoxification device 40. Furthermore, since a large amount of gas is not continuously sent from the dilution tank 20 to the detoxification device 40, there is no need for the detoxification device 40 to treat a large amount of ammonia in a short period of time, which also makes it possible to reduce the size of the detoxification device 40. Furthermore, even if the detoxification device 40 requires a long time to start up when detoxifying ammonia, for example, it is possible to employ such a device.

[0075] (2) The ammonia detoxification system 100 according to the second aspect is the ammonia detoxification system 100 of (1), wherein the control device 60 transitions the flow control valve 35 from a closed state to an open state when the gas phase in the dilution tank 20 and the liquid phase in the dilution tank 20 reach a gas-liquid equilibrium state.

[0076] In this way, when the gas phase and the liquid phase in the dilution tank 20 reach a gas-liquid equilibrium state, the flow control valve 35 is transitioned from a closed state to an open state, so that the ammonia contained in the purge gas can be absorbed to the maximum extent by the dilution liquid in the dilution tank 20. Therefore, the ammonia concentration of the gas in the gas phase in the dilution tank 20 can be sufficiently reduced before it is sent to the abatement device 40.

[0077] (3) The ammonia detoxification system 100 according to the third aspect is the ammonia detoxification system 100 of (2), further comprising a pressure sensor 27p for detecting the pressure of the gas phase in the dilution tank 20, or a concentration sensor 27c for detecting the ammonia concentration in at least one of the gas phase and liquid phase in the dilution tank 20, and the control device 60 determines whether the gas-liquid equilibrium state has been reached based on at least one of the amount of change in pressure in the dilution tank 20 detected by the pressure sensor 27p and the ammonia concentration detected by the concentration sensor 27c.

[0078] This allows the amount of change in pressure inside the dilution tank 20 detected by the pressure sensor 27p to be used as a criterion for determining whether or not gas-liquid equilibrium has been achieved, making it possible to easily determine whether or not gas-liquid equilibrium has been achieved. Also, the ammonia concentration detected by the concentration sensor 27c can be used as a criterion for determining whether or not gas-liquid equilibrium has been achieved, making it possible to easily determine whether or not gas-liquid equilibrium has been achieved.

[0079] (4) The ammonia detoxification system 100 according to the fourth aspect is any one of the ammonia detoxification systems 100 of (1) to (3), and further includes a temperature sensor 27t that detects the temperature of the gas phase in the dilution tank 20, and the control device 60 prohibits control of the flow control valve 35 to transition from a closed state to an open state when the temperature of the gas phase in the dilution tank 20 detected by the temperature sensor 27t is not below a reference temperature.

[0080] When ammonia contained in the purge gas is absorbed by the treatment liquid in the dilution tank 20, the heat of reaction increases the temperatures of the gas in the gas phase and the liquid in the liquid phase in the dilution tank 20. Some detoxification devices 40 do not allow high-temperature gas to be fed into them. In response to this, by prohibiting control of the flow rate control valve 35 to transition from a closed state to an open state when the gas-phase temperature in the dilution tank 20 detected by the temperature sensor 27t is not below a reference temperature, it is possible to prevent gas of an excessively high temperature from being fed into the detoxification device 40. This allows the detoxification function of the detoxification device 40 to be fully exerted.

[0081] (5) The ammonia detoxification system 100 according to the fifth aspect is any one of the ammonia detoxification systems 100 of (1) to (4), and further includes a flow sensor 27f that detects the flow rate of the gas discharged from the dilution tank 20 through the discharge line 30, and the control device 60 reduces the opening of the flow control valve 35 when the flow rate of the gas detected by the flow sensor 27f exceeds a reference flow rate.

[0082] When the flow rate of the gas detected by the flow rate sensor 27f exceeds the reference flow rate, the flow rate of the gas sent to the detoxification device 40 can be suppressed to be equal to or lower than the reference flow rate.

[0083] (6) The sixth aspect of the ammonia detoxification system 100 is any one of the ammonia detoxification systems 100 of (1) to (5), and the control device 60 closes the flow control valve 35 when the purge gas is introduced from the gas distribution line 10 into the dilution tank 20.

[0084] In this configuration, when purge gas is introduced into the dilution tank 20 from the gas distribution line 10, the flow rate control valve 35 is closed, so that the purge gas introduced into the dilution tank 20 can be temporarily stored in the dilution tank 20. Therefore, the ammonia contained in the purge gas can be sufficiently absorbed by the absorption liquid L in the dilution tank 20, and the ammonia concentration in the gas phase of the dilution tank 20 can be sufficiently reduced. In addition, the purge gas that flows in in large amounts during purging can be prevented from reaching the detoxification device 40 from the dilution tank 20.

[0085] (7) The seventh aspect of the ammonia detoxification system 100 is any one of the ammonia detoxification systems 100 of (1) to (6), further comprising an on-off valve 15 for opening and closing the gas distribution line 10, and the on-off valve 15 is closed when gas is discharged from the gas phase in the dilution tank 20 to the outside through the discharge line 30.

[0086] This prevents the gas phase gas temporarily stored in the dilution tank 20 from flowing back through the gas distribution line 10.

[0087] (8) The ammonia detoxification system 100 according to an eighth aspect is any one of the ammonia detoxification systems 100 according to (1) to (7), in which the dilution tank 20 is formed by a pressure vessel. This allows the purge gas to be stored at an increased pressure when it is temporarily stored in the dilution tank 20. This makes it possible to reduce the size of the dilution tank 20, thereby contributing to the reduction in size of the ammonia detoxification system 100 as a whole.

[0088] (9) The ammonia detoxification system 100 according to the ninth aspect is any one of the ammonia detoxification systems 100 according to (1) to (8), and further includes an on-off valve 15 that opens and closes the gas distribution line 10, and a bypass line 10a that bypasses the dilution tank 20 and can connect the gas distribution line 10 upstream of the on-off valve 15 to the gas distribution line 10 downstream of the flow control valve 35. This allows residual pressure remaining in the gas distribution line 10 due to the internal pressure of the dilution tank 20 to be released to a downstream side of the flow rate adjustment valve 35, such as the detoxification device 40, etc.

[0089] (10) A float according to a tenth aspect includes a float body and any one of the ammonia detoxification systems 100 according to (1) to (9). This makes it possible to provide a float equipped with an ammonia detoxification system that can ensure ammonia absorption during purging.

[0090] (11) An ammonia detoxification system 100 according to an eleventh aspect is a method for detoxifying ammonia in the ammonia detoxification system 100 of any one of (1) to (10), and includes the steps of: a step S11 of introducing the purge gas from the gas circulation line into the dilution tank 20; a step S14 of temporarily storing the purge gas introduced into the dilution tank 20 in the dilution tank 20 and causing the absorption liquid L to absorb the ammonia contained in the purge gas; and a step S16 of transitioning the flow control valve 35 from a closed state to an open state when the ammonia concentration in the gas phase in the dilution tank 20 falls below a predetermined value, and sending the gas from the gas phase in the dilution tank 20 through the delivery line 30 to the detoxification device 40. This ensures ammonia absorption during purging. [Explanation of symbols]

[0091] 1...floating body 2...floating body main body 2a...bow 4...superstructure 5A, 5B...shipside 6...bottom of the vessel 7...upper deck 8...combustion device 9...funnel 10...gas distribution line 15...on-off valve 20...dilution tank 22...absorption promotion section 23...circulation line 24...spray 25...circulation pump 27c...concentration sensor 27f...flow rate sensor 27p...pressure sensor 27t...temperature sensor 30...discharge line 35...flow rate control valve 40...ammonia removal device 41...absorption tower 41a...tower main body 50...exhaust line 60...control device 61...CPU 62...ROM 63...RAM 64...storage 65...signal transmission / reception module 70...signal input section 71...information acquisition section 72...valve control section 75...output section 100...ammonia removal system FA...fore-aft direction L...absorption liquid S10...Ammonia detoxification method S11...Step of introducing purge gas S12...Step of determining the end of purging S13...Step of terminating the introduction of purge gas S14...Step of absorbing ammonia S15...Step of determining whether or not a gas-liquid equilibrium state is reached S16...Step of sending gas in the gas phase to the detoxification device S17...Step of determining whether or not the reference flow rate has been exceeded S18...Step of reducing the flow rate of the gas S19...Step of terminating the ammonia detoxification treatment

Claims

1. a gas distribution line through which a purge gas containing ammonia and an inert gas flows; a detoxification device that detoxifies the ammonia; a dilution tank, a delivery line, and a flow control valve for batch processing, which are provided between the gas distribution line and the detoxification device; Equipped with the dilution tank stores an absorption liquid capable of absorbing the ammonia and is capable of temporarily storing the purge gas supplied from the gas distribution line, the delivery line is capable of delivering the gas in the gas phase in the dilution tank to the detoxification device, the flow rate adjusting valve is provided in the delivery line, A control device for controlling the opening and closing operation of the flow rate adjustment valve is further provided, The control device When the ammonia concentration in the gas phase in the dilution tank in which the purge gas is temporarily stored falls below a predetermined value, the flow rate adjustment valve is transitioned from a closed state to an open state. Ammonia abatement system.

2. The control device When the gas phase in the dilution tank and the liquid phase in the dilution tank reach a gas-liquid equilibrium state, the flow rate adjustment valve is transitioned from a closed state to an open state.

10. The ammonia abatement system of claim 1.

3. Further provided is a pressure sensor for detecting the pressure of the gas phase in the dilution tank, or a concentration sensor for detecting the ammonia concentration in at least one of the gas phase and the liquid phase in the dilution tank, The control device Whether or not the gas-liquid equilibrium state has been reached is determined based on at least one of the amount of change in pressure in the dilution tank detected by the pressure sensor and the ammonia concentration detected by the concentration sensor. The ammonia abatement system of claim 2 .

4. Further provided is a temperature sensor for detecting the temperature of the gas phase in the dilution tank; The control device When the temperature of the gas phase in the dilution tank detected by the temperature sensor is not lower than a reference temperature, control for transitioning the flow rate adjustment valve from a closed state to an open state is prohibited.

3. The ammonia abatement system according to claim 1 or 2.

5. a flow rate sensor for detecting a flow rate of the gas delivered from the dilution tank through the delivery line; The control device When the flow rate of the gas detected by the flow rate sensor exceeds a reference flow rate, the opening of the flow rate adjustment valve is reduced.

3. The ammonia abatement system according to claim 1 or 2.

6. The control device When the purge gas is introduced into the dilution tank from the gas distribution line, the flow rate adjustment valve is closed.

3. The ammonia abatement system according to claim 1 or 2.

7. further comprising an on-off valve for opening and closing the gas distribution line; When the gas is discharged from the gas phase in the dilution tank to the outside through the delivery line, the on-off valve is closed.

3. The ammonia abatement system according to claim 1 or 2.

8. The dilution tank is formed by a pressure vessel.

3. The ammonia abatement system according to claim 1 or 2.

9. an on-off valve that opens and closes the gas distribution line; 3. The ammonia detoxification system according to claim 1, further comprising a bypass line that bypasses the dilution tank and connects the gas distribution line upstream of the on-off valve to the gas distribution line downstream of the flow control valve.

10. A floating body; The ammonia detoxification system according to claim 1 or 2. Floating body.

11. 3. An ammonia detoxification method in an ammonia detoxification system according to claim 1 or 2, introducing the purge gas into the dilution tank through the gas distribution line; a step of temporarily storing the purge gas introduced into the dilution tank in the dilution tank and absorbing ammonia contained in the purge gas with the absorption liquid; and when the ammonia concentration in the gas phase in the dilution tank falls below a predetermined value, transitioning the flow rate control valve from a closed state to an open state, and sending gas from the gas phase in the dilution tank to the detoxification device through the delivery line. Ammonia detoxification method.

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