Ships

Abstract

To provide a vessel capable of recovering ammonia as ammonia water and suppressing enlargement of a hull.SOLUTION: The vessel comprises: an ammonia recovery unit that absorbs ammonia in water and recovers it as recovered ammonia water; a regeneration tower that heats the recovered ammonia water and separates the recovered ammonia water into ammonia removed water and ammonia steam; a gas-liquid separation unit that separates the ammonia steam separated at the regeneration tower into an ammonia gas and a separated liquid; and a separated liquid circulation unit that circulates the separated liquid to the regeneration tower.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to marine vessels. [Background technology]

[0002] Ships carrying fuel for ship propulsion or flammable gas as cargo are provided with vent posts for discharging the flammable gas into the atmosphere outside the ship. For example, Patent Document 1 discloses a configuration in which flammable gas remaining in the piping of a gas engine driven by flammable gas (gas fuel) is purged with nitrogen gas or the like and released to the atmosphere through the vent post. It is being considered to load ammonia as a gas fuel on the above-mentioned ship. Ammonia may not diffuse sufficiently even if it is purged with an inert gas and released into the atmosphere through a vent post. One of the reasons why ammonia does not diffuse easily into the atmosphere is that ammonia reacts more easily with moisture in the air than other flammable gases such as methane gas and butane gas, and reacts with moisture in the air to become mist-like (droplet-like) ammonia water, which has a higher specific gravity than the air.

[0003] On the other hand, Patent Document 2 discloses a recovery device that recovers ammonia from exhaust gas. The recovery device disclosed in Patent Document 2 includes a dissolution tank that dissolves exhaust gas in water, and an ammonia water tank that stores the ammonia water formed in the dissolution tank. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-11332 A [Patent Document 2] JP 2008-7378 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the recovery device of Patent Document 2, high-purity ammonia is recovered by dehumidifying the ammonia gas obtained by distilling ammonia water and then liquefying it, and the water generated in the process of distilling ammonia water is returned to the dissolving device, which is an upstream process rather than to the ammonia water tank. However, in a ship, returning the water generated in the process of distilling ammonia water to the dissolving device requires additional space for installing piping inside the hull, which leads to an increase in the size of the ship, which is a problem. Furthermore, the recovery device of Patent Document 2 requires thermal energy to regenerate ammonia. In addition, since the water returned to the dissolving device of Patent Document 2 contains a small amount of ammonia, the water from which the ammonia has been separated cannot be discharged overboard for reasons such as preventing marine pollution. For example, if the amount of ammonia water in an ammonia water tank exceeds an upper limit, it becomes necessary to neutralize or dilute the ammonia contained in the water before discharging it overboard, which poses the problem of requiring separate equipment for neutralization or dilution and / or a larger ammonia water tank. The present disclosure has been made to solve the above-mentioned problems, and aims to provide a ship that is capable of recovering ammonia as ammonia water, suppressing the discharge of recovered ammonia overboard, while saving energy and suppressing the increase in size of the hull. [Means for solving the problem]

[0006] A ship according to the present disclosure includes an ammonia tank provided in a hull and storing ammonia, a combustion device driven by the ammonia stored in the ammonia tank, an ammonia recovery section that absorbs the ammonia into water and recovers it as recovered ammonia water, a regeneration tower that heats the recovered ammonia water and separates the recovered ammonia water into ammonia-removed water and ammonia vapor, a gas-liquid separation section that separates the ammonia vapor separated in the regeneration tower into ammonia gas and a separated liquid, a separated liquid reflux section that refluxes the separated liquid to the regeneration tower, and an inert gas supply device that supplies an inert gas to a fuel flow path of the combustion device to purge fuel ammonia remaining in the fuel flow path. an ammonia-removed water tank for storing the ammonia-removed water separated by the regeneration tower; a removed water return line for returning the ammonia-removed water in the ammonia-removed water tank to the regeneration tower; an ammonia-removed water delivery pump provided in the removed water return line for delivering the ammonia-removed water from the ammonia-removed water tank; and an overboard discharge line branching off from the removed water return line closer to the regeneration tower than the ammonia-removed water delivery pump and discharging the ammonia-removed water in the ammonia-removed water tank overboard to be discharged into the ocean.The ammonia recovery section absorbs the purged fuel ammonia in water and recovers it as recovered ammonia. Effect of the Invention

[0007] According to the ship of the above aspect, it is possible to recover ammonia as ammonia water, and it is possible to reduce energy consumption and prevent the ship from becoming larger while suppressing the discharge of recovered ammonia overboard. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a side view of a marine vessel according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a diagram showing a piping system for performing fuel purging in a marine vessel according to an embodiment of the present disclosure. [Diagram 3] FIG. 2 is a diagram showing a piping system around a regenerator according to an embodiment of the present disclosure. [Figure 4] FIG. 5 is a diagram corresponding to FIG. 3 in a modified example of the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A marine vessel according to an embodiment of the present disclosure will now be described with reference to the drawings. Fig. 1 is a side view of a marine vessel according to an embodiment of the present disclosure. (Vessel configuration) As shown in Fig. 1, the ship 1 of this embodiment includes a hull 2, a superstructure 4, a combustion device 8, an ammonia tank 10, a piping system 20, a vent post 30, an ammonia recovery section 60, and a recovered ammonia water tank 70. The type of the ship 1 is not limited to a specific one. Examples of the type of the ship 1 include a liquefied gas carrier, a ferry, a RORO ship, a car carrier, and a passenger ship.

[0010] The hull 2 ​​has a pair of side walls 5A, 5B and a ship bottom 6 that form its outer hull. The side walls 5A, 5B each have a pair of side shell plates that form the starboard and port sides, respectively. The ship bottom 6 has a bottom shell plate that connects the side walls 5A, 5B. The pair of side walls 5A, 5B and the ship bottom 6 give the outer hull 2 ​​a U-shape in a cross section perpendicular to the bow-stern direction FA.

[0011] The hull 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 ship 1 of this embodiment, for example, a cargo space (not shown) for carrying cargo is provided closer to the bow 3a in the bow-stern direction FA than the superstructure 4.

[0012] The combustion device 8 is a device that generates thermal energy by burning fuel, and is provided inside the hull 2. Examples of the combustion device 8 include an internal combustion engine used in a main engine for propelling the ship 1, an internal combustion engine used in a generator or the like that supplies electricity to the ship, and a boiler that generates steam as a working fluid. The combustion device 8 of this embodiment uses ammonia (hereinafter referred to as fuel ammonia) as fuel.

[0013] The ammonia tank 10 stores liquefied ammonia as fuel ammonia. The ammonia tank 10 illustrated in this embodiment is installed on the upper deck 7 on the stern 3b side of the superstructure 4, but the location of the ammonia tank 10 is not limited to on the upper deck 7 on the stern 3b side of the superstructure 4. The piping system 20 connects the combustion device 8 and the ammonia tank 10. The piping system 20 supplies the fuel ammonia stored in the ammonia tank 10 to the combustion device 8.

[0014] The vent post 30 guides gas, such as vent gas discharged from a cargo tank, above the upper deck 7 and releases it into the atmosphere. The vent post 30 of this embodiment is provided on the upper deck 7 and extends upward from the upper deck 7. The vent post 30 is tubular and extends in the vertical direction Dv, and is open at the top.

[0015] The ammonia recovery unit 60 absorbs the ammonia to be recovered into water W and recovers it as recovered ammonia water. The ammonia recovery unit 60 of this embodiment is disposed on the upper deck 7 closer to the stern 3b than the ammonia tank 10. As the ammonia recovery unit 60, for example, a so-called scrubber that injects water into gas containing ammonia to absorb the ammonia into the water can be used. The ammonia recovery unit 60 is supplied with water (e.g., fresh water) stored in a water tank (not shown) provided in the hull 2. Note that the ammonia recovery unit 60 is not limited to the above configuration and arrangement as long as it is configured to absorb ammonia into water and recover it as recovered ammonia water.

[0016] The recovered ammonia water tank 70 stores the recovered ammonia water recovered by the ammonia recovery section 60. In this embodiment, the recovered ammonia water tank 70 is disposed inside the hull 2 ​​below the upper deck 7 on which the ammonia recovery section 60 is installed. Note that the recovered ammonia water tank 70 is not limited to the above-mentioned arrangement as long as it is configured to recover the ammonia recovered by the ammonia recovery section 60 as recovered ammonia water.

[0017] (Configuration of piping system related to purging) FIG. 2 is a diagram showing a piping system for performing fuel purging in a marine vessel according to an embodiment of the present disclosure. As shown in Fig. 2, the ship 1 of this embodiment includes an ammonia buffer tank 40 that temporarily stores fuel ammonia supplied from the ammonia tank 10. The ammonia buffer tank 40 is installed in the middle of a piping system 20 between the ammonia tank 10 and the combustion device 8. The piping system 20 includes an ammonia fuel supply line 115 (see Fig. 3), which will be described later, a supply pipe 21, a return pipe 22, and on-off valves 23 and 24. An inert gas supply device 50 and an ammonia recovery section 60 are connected to the piping system 20.

[0018] The supply pipe 21 and the return pipe 22 respectively connect the ammonia buffer tank 40 and the combustion device 8. The supply pipe 21 supplies fuel ammonia from the ammonia buffer tank 40 to the combustion device 8. The return pipe 22 returns surplus fuel ammonia that has not been used as fuel in the combustion device 8 to the ammonia buffer tank 40. Note that the supply pipe 21 is provided with an ammonia pressure pump 117 and an ammonia heat exchanger 118 (see FIG. 3), which will be described later, but are omitted from FIG. 2.

[0019] The on-off valve 23 is provided in the supply pipe 21. The on-off valve 24 is provided in the return pipe 22. These on-off valves 23, 24 are constantly open when the combustion device 8 is in operation. On the other hand, the on-off valves 23, 24 are closed when the combustion device 8 is stopped, etc. When these on-off valves 23, 24 are closed, the flow paths formed inside the supply pipe 21 and the return pipe 22 are shut off.

[0020] The inert gas supplying device 50 replaces the fuel ammonia in the flow path R through which the fuel ammonia flows as the fuel for the combustion device 8 with an inert gas such as nitrogen, so-called purging. The inert gas supplying device 50 includes an inert gas supplying unit 51, an inert gas supplying pipe 52, and an inert gas supplying valve 53. As the inert gas, for example, an inert gas generated inside the hull 2 ​​by an inert gas generating device (not shown) or an inert gas stored in advance in an inert gas tank (not shown) provided in the hull 2 ​​can be used. Note that the inert gas may be any gas that does not chemically react when it comes into contact with the fuel ammonia.

[0021] The inert gas supply unit 51 supplies an inert gas to the inert gas supply pipe 52 . The inert gas supply pipe 52 connects the inert gas supply unit 51 and the flow path R. More specifically, the inert gas supply pipe 52 connects the inert gas supply unit 51 and a purging target area 20p of the flow path R. The purging target area 20p in this embodiment is the supply pipe 21 on the combustion device 8 side of the on-off valve 23, the return pipe 22 on the combustion device 8 side of the on-off valve 24, and the flow path R formed in the combustion device 8. The inert gas supply pipe 52 illustrated in this embodiment is connected to the purging target area 20p of the supply pipe 21 among the purging target areas 20p.

[0022] The inert gas supply valve 53 is provided in the inert gas supply pipe 52. The inert gas supply valve 53 is normally closed to block the supply of inert gas from the inert gas supply unit 51 to the purging target area 20p. Here, the normal state refers to a state in which fuel ammonia can be supplied to the combustion device 8, such as when the combustion device 8 is operating. During this normal state, the on-off valves 23 and 24 are open to allow fuel ammonia to be supplied from the ammonia buffer tank 40 to the combustion device 8 through the supply pipe 21, and excess fuel ammonia is returned from the combustion device 8 to the ammonia buffer tank 40.

[0023] The inert gas supply valve 53 is changed from a closed state to an open state during an emergency stop or long-term stop of the combustion device 8. In other words, it is operated from a closed state to an open state when purging the fuel ammonia remaining in the purging target area 20p. When performing such purging, the on-off valves 23 and 24 are first changed to a closed state, and the supply pipe 21 and the return pipe 22 are blocked. This stops the supply of fuel ammonia from the ammonia buffer tank 40 to the combustion device 8. Next, when the inert gas supply valve 53 is changed from a closed state to an open state, this allows the inert gas to be supplied from the inert gas supply unit 51 to the purging target area 20p.

[0024] The vent pipe 38 guides the fuel ammonia remaining in the flow path R to the outside together with the inert gas supplied by the inert gas supply device 50. The fuel ammonia flows out to the vent pipe 38 together with the inert gas, so that the fuel ammonia in the purged region 20p (flow path R) is replaced with the inert gas.

[0025] The vent pipe 38 of this embodiment includes an upstream vent pipe 38A and a downstream vent pipe 38B. The upstream vent pipe 38A is , Pa The upstream vent pipe 38A connects the target region 20p and the ammonia recovery section 60. The upstream vent pipe 38A illustrated in this embodiment is connected to the return pipe 22. The downstream vent pipe 38B connects the ammonia recovery section 60 and the vent post 30. That is, a mixed fluid of an inert gas and ammonia fuel flows through the upstream vent pipe 38A, and the remaining fluid from which the ammonia fuel has been recovered by the ammonia recovery section 60 flows through the downstream vent pipe 38B.

[0026] The ammonia recovery section 60 in this embodiment is connected to a recovered ammonia water tank 70 via a recovery pipe 71. This recovery pipe 71 is provided with a recovery pipe on-off valve 72. The ammonia water generated in the ammonia recovery section 60 moves to the recovered ammonia water tank 70 via the recovery pipe 71 when this recovery pipe on-off valve 72 is in an open state. In this embodiment, since the recovered ammonia water tank 70 is disposed below the ammonia recovery section 60, the ammonia water generated by the ammonia recovery section 60 can flow down to the recovered ammonia water tank 70 by its own weight.

[0027] (Configuration for removing ammonia from recovered ammonia water) FIG. 3 is a diagram showing a piping system around a regenerator according to an embodiment of the present disclosure. As shown in FIG. 3, the ship 1 of this embodiment further includes an exhaust gas economizer 81, a steam generating section 82, a heater section 83, a recovered ammonia water supply line 84, a recovered ammonia water delivery pump 85, a regeneration tower 86, a condenser 87, a gas-liquid separation section 88, a separated liquid reflux section 89, an ammonia gas dehumidifier 90, an ammonia gas recovery and reuse section 91, an ammonia removed water tank 92, an ammonia removed water delivery pump 93, a removed water reflux line 94, and an overboard discharge line 95, as a configuration for removing ammonia from the recovered ammonia water described above.

[0028] The exhaust gas economizer 81 recovers heat from the exhaust gas G of the combustion device 8. The exhaust gas economizer 81 of this embodiment is installed in the middle of an exhaust pipe that leads the exhaust gas G from the combustion device 8 to the outside of the ship. The exhaust gas economizer 81 recovers heat from the exhaust gas G by exchanging heat between the exhaust gas G and a heat medium. The heat medium that has exchanged heat with the exhaust gas G in the exhaust gas economizer 81 is supplied to a steam generating section 82. The exhaust gas economizer 81 of this embodiment is connected to the steam generating section 82 via a pipe 81a that circulates the heat medium. In addition, a pump 81b for circulating the heat medium is provided in the pipe 81a.

[0029] The steam generating unit 82 generates steam from the heat recovered by the exhaust gas economizer 81. A boiler or a steam separator can be used as the steam generating unit 82. The steam generated by the steam generating unit 82 is supplied to the heater body 103 of the heater unit 83 via a steam supply pipe 82a.

[0030] The heater unit 83 uses the steam supplied from the steam generating unit 82 to heat the liquid stored in the lower part of the regenerator 86. The heater unit 83 in this embodiment includes a circulation pipe 101 capable of circulating the liquid stored in the lower part of the regenerator 86, a circulation pump 102 provided midway through the circulation pipe 101, and a heater main body 103 that heats the liquid stored in the lower part of the regenerator 86 by exchanging heat between the steam supplied from the steam generating unit 82 and the liquid circulated by the circulation pipe 101.

[0031] The recovered ammonia water supply line 84 connects the recovered ammonia water tank 70 and the regeneration tower 86. The inside of the recovered ammonia water tank 70 and the inside of the regeneration tower 86 are communicated with each other via the recovered ammonia water supply line 84. The recovered ammonia water supply line 84 in this embodiment is connected to the upper part of the regeneration tower 86. The recovered ammonia water delivery pump 85 is provided on the recovered ammonia water supply line 84. The recovered ammonia water delivery pump 85 delivers the recovered ammonia water stored in the recovered ammonia water tank 70 toward the regeneration tower 86.

[0032] The regeneration tower 86 heats the recovered ammonia water to separate it into ammonia-removed water and ammonia vapor. More specifically, the regeneration tower 86 heats the recovered ammonia water supplied via the recovered ammonia water supply line 84 with the heater unit 83, and separates ammonia vapor from the recovered ammonia water by utilizing the difference in boiling points between ammonia and water. Here, the ammonia-removed water means the remainder of the recovered ammonia water from which the ammonia vapor has been separated in the regeneration tower 86. That is, the ammonia concentration of the ammonia-removed water is lower than the ammonia concentration of the recovered ammonia water. The ammonia-removed water may be mixed with newly supplied recovered ammonia water inside the regeneration tower 86.

[0033] The condenser 87 cools the ammonia vapor separated in the regenerator 86 to reduce the volume of the ammonia vapor. The condenser 87 is provided in the middle of the ammonia vapor line 104. One end of the ammonia vapor line 104 is connected to the upper part of the regenerator 86, and the other end of the ammonia vapor line 104 is connected to the gas-liquid separation section 88. In other words, the condenser 87 condenses the ammonia vapor separated in the regenerator 86 while sending the ammonia vapor to the gas-liquid separation section 88. The ammonia vapor supplied to the condenser 87 contains moisture.

[0034] The gas-liquid separation unit 88 separates the ammonia vapor into ammonia gas and a separated liquid. The ammonia gas separated by the gas-liquid separation unit 88 is sent to the ammonia gas dehumidifier 90 via an ammonia gas supply line 108. Here, the separated liquid is the remainder obtained when the ammonia gas is separated from the ammonia vapor. The separated liquid is water containing a small amount of ammonia. The gas-liquid separation by the gas-liquid separation unit 88 can be exemplified by a method of cooling the ammonia vapor to separate the gas and liquid, but the gas-liquid separation by the gas-liquid separation unit 88 is not limited to a method of cooling the ammonia vapor.

[0035] The separated liquid reflux section 89 refluxes the separated liquid obtained by gas-liquid separation in the gas-liquid separation section 88 to the regenerator 86. In this embodiment, the separated liquid reflux section 89 includes a reflux line 105, a reflux on-off valve 106, and a reflux pump 107. The reflux line 105 connects the gas-liquid separation section 88 to the regenerator 86. The reflux on-off valve 106 opens and closes a flow path formed inside the reflux line 105. The reflux pump 107 is provided in the reflux line 105 and pumps the separated liquid from the gas-liquid separation section 88 toward the regenerator 86.

[0036] The ammonia gas dehumidifier 90 dehumidifies the ammonia gas separated by the gas-liquid separation unit 88. The ammonia gas dehumidified by the ammonia gas dehumidifier 90 is sent to the ammonia gas recovery and reuse unit 91 via a dehumidified gas supply line 109. Since the ammonia gas separated by the gas-liquid separation unit 88 contains a small amount of moisture, the ammonia gas dehumidifier 90 dehumidifies the ammonia gas as a preliminary step to liquefying the ammonia gas. Note that if the humidity of the ammonia gas separated by the gas-liquid separation unit 88 is sufficiently low, the ammonia gas dehumidifier 90 may be omitted.

[0037] The ammonia gas recovery and recycling section (ammonia gas liquefaction section) 91 liquefies the ammonia gas and supplies it to the ammonia tank 10. The ammonia liquefied by the ammonia gas recovery and recycling section 91 is sent to the ammonia tank 10 via the ammonia return line 110. In the ammonia gas recovery and recycling section 91, a method of increasing the pressure of the ammonia gas by a gas compressor (not shown) and then cooling the ammonia gas by heat exchange with seawater can be exemplified as a method of liquefying the ammonia gas. In addition, the ammonia gas can be liquefied by increasing the pressure of the ammonia gas by a gas compressor (not shown) and then expanding the ammonia gas by an expansion valve (not shown), flowing the ammonia gas into the ammonia tank 10, and contacting the liquefied ammonia stored in the ammonia tank 10. In addition, as the ammonia gas recovery and recycling section 91, for example, in the case where the ship 1 has a cargo tank, a reliquefaction device (not shown) that reliquefies boil-off gas generated in the cargo tank may be used.

[0038] The ammonia-removed water tank 92 stores the ammonia-removed water separated by the regeneration tower 86 . The removed water reflux line 94 forms a flow path for refluxing the ammonia-removed water stored in the ammonia-removed water tank 92 to the regeneration tower 86 .

[0039] The ammonia-removed water delivery pump 93 delivers the ammonia-removed water from the ammonia-removed water tank 92. The ammonia-removed water delivery pump 93 in the present embodiment is disposed in the removed water return line 94 near the ammonia-removed water tank 92.

[0040] The overboard discharge line 95 discharges the ammonia-removed water from the ammonia-removed water tank 92 overboard. In this embodiment, the overboard discharge line 95 branches off from the removed water return line 94 which is closer to the regeneration tower 86 than the ammonia-removed water delivery pump 93 is.

[0041] Here, the removed water return line 94 is provided with an on-off valve 111 on the side closer to the regenerator 86 than the branch point P1 with the overboard discharge line 95. In addition, the overboard discharge line 95 is provided with an on-off valve 112. The on-off valve 111 provided in the removed water return line 94 is opened when the ammonia-removed water is returned from the ammonia-removed water tank 92 to the regenerator 86, and is closed when the ammonia-removed water is discharged from the ammonia-removed water tank 92 to the overboard. In addition, the on-off valve of the overboard discharge line 95 is closed when the ammonia-removed water is returned from the ammonia-removed water tank 92 to the regenerator 86, and is opened when the ammonia-removed water is discharged from the ammonia-removed water tank 92 to the overboard. In this embodiment, when the ammonia concentration of the ammonia-removed water stored in the ammonia-removed water tank 92 is a concentration that allows for release overboard, the ammonia-removed water is discharged overboard, and when the release overboard is not allowed, the ammonia-removed water is returned to the regenerator to separate ammonia vapor again.

[0042] Furthermore, in this embodiment, an ammonia fuel supply line 115 connecting the ammonia tank 10 and the ammonia buffer tank 40 is provided with a feed pump 116 that feeds the fuel ammonia toward the combustion device 8. 2, the supply pipe 21 of this embodiment is provided with an ammonia pressure pump 117 and an ammonia heat exchanger 118. The ammonia pressure pump 117 pressurizes the fuel ammonia supplied from the ammonia buffer tank 40 to the combustion device 8. The ammonia heat exchanger 118 heats the fuel ammonia pressurized by the ammonia pressure pump 117. The ammonia buffer tank 40 and the ammonia recovery section 60 of this embodiment are connected by a buffer tank vent pipe 119, and are configured to be able to supply the vent gas of the ammonia buffer tank 40 to the ammonia recovery section 60. This allows the ammonia contained in the vent gas of the ammonia buffer tank 40 to be recovered in the ammonia recovery section 60.

[0043] (Action and effect) The ship 1 of the above embodiment is equipped with an ammonia recovery section 60 that absorbs ammonia into water and recovers it as recovered ammonia water, a regeneration tower 86 that heats the recovered ammonia water and separates it into ammonia-removed water and ammonia vapor, a gas-liquid separation section 88 that separates the ammonia vapor separated in the regeneration tower 86 into ammonia gas and separated liquid, and a separated liquid reflux section 89 that refluxes the separated liquid to the regeneration tower 86.

[0044] According to such a ship 1, in the process of extracting ammonia from the recovered ammonia water, the ammonia vapor is separated into ammonia gas and a separated liquid by the gas-liquid separation unit 88, and the separated liquid can be returned to the regeneration tower 86, which separates the ammonia into ammonia-removed water and ammonia vapor, and can be processed again. Therefore, it is possible to reduce the installation space of the piping inside the hull 2 ​​compared to, for example, a case in which the separated liquid is used as water for absorbing ammonia in the ammonia recovery unit 60. Furthermore, since it is not necessary to discharge the separated liquid outside the ship, a device for neutralizing or diluting the ammonia contained in the separated liquid is not required. Therefore, it is possible to prevent the size of the hull 2 ​​from increasing while recovering ammonia as recovered ammonia water. Furthermore, since ammonia can be regenerated from this recovered ammonia water by utilizing the exhaust gas energy of the ship 1, it is possible to achieve energy saving. Furthermore, since ammonia can be regenerated from this recovered ammonia water by utilizing the exhaust gas energy of the ship 1, it is possible to prevent the discharge of the recovered ammonia water outside the ship.

[0045] The ship 1 of the above embodiment further includes an ammonia tank 10 provided in the hull 2 ​​and storing fuel ammonia, and a combustion device 8 driven by the fuel ammonia stored in the ammonia tank 10. The regenerator 86 heats the recovered ammonia water by utilizing exhaust heat from the combustion device 8, and separates the recovered ammonia water into ammonia-removed water and ammonia vapor. In this way, in a ship 1 equipped with a combustion device 8 such as a main engine that uses ammonia as fuel, the exhaust heat of the combustion device 8 can be effectively utilized when separating ammonia from recovered ammonia water. In addition, the separated ammonia can be used as fuel ammonia for the combustion device 8 or for other purposes (for example, as a reducing agent for a denitration device, etc.).

[0046] The ship 1 of the above embodiment further includes an exhaust gas economizer 81 that recovers heat from the exhaust gas of the combustion device 8, a steam generating unit 82 that generates steam from the heat recovered by the exhaust gas economizer 81, and a heater unit 83 that uses the steam generated by the steam generating unit 82 to heat the liquid stored in the lower part of the regenerator 86. In this way, the heat recovered by the exhaust gas economizer 81 can be transferred to the ammonia-removed water or the like, which is a liquid stored in the lower part of the regenerator 86, using steam as a heat medium. Therefore, when the ship 1 has the exhaust gas economizer 81, it becomes possible to easily utilize the exhaust heat of the combustion device 8 in the regenerator 86.

[0047] The ship 1 of the above embodiment further includes an ammonia gas recovery and reuse unit 91 that liquefies the ammonia gas separated in the gas-liquid separation unit 88 and supplies the liquefied ammonia gas to the ammonia tank 10. In this way, it becomes possible to use the ammonia tank 10 as a tank for storing the ammonia extracted from the recovered ammonia water. Therefore, a dedicated tank for storing the ammonia liquefied in the ammonia gas recovery and reuse unit 91 can be omitted.

[0048] The ship 1 of the above embodiment further includes a condenser 87 that cools the ammonia vapor separated in the regenerator 86 to reduce the volume of the ammonia vapor. In this way, the gas-liquid separation process in the gas-liquid separator 88 can be carried out efficiently.

[0049] The separated liquid reflux section 89 of the ship 1 in the above embodiment includes a reflux line 105 that connects the gas-liquid separation section 88 and the regenerator 86, and a reflux pump 107 that pumps the separated liquid toward the regenerator 86. In this manner, the separated liquid separated in the gas-liquid separation section 88 can be actively sent to the regeneration tower 86 by the reflux pump 107 .

[0050] The ship 1 of the above embodiment further includes a recovered ammonia water tank 70 for storing the recovered ammonia water recovered by the ammonia recovery section 60, a recovered ammonia water supply line 84 connecting the recovered ammonia water tank 70 and the regeneration tower 86, and a recovered ammonia water delivery pump 85 provided in the recovered ammonia water supply line 84 for delivering the recovered ammonia water from the recovered ammonia water tank 70 to the regeneration tower 86. In this manner, the recovered ammonia water recovered by the ammonia recovery section 60 can be temporarily stored in the recovered ammonia water tank 70. Then, the recovered ammonia water stored in the recovered ammonia water tank 70 can be sent to the regeneration tower 86 by the recovered ammonia water delivery pump 85. Therefore, the step of separating the recovered ammonia water performed in the regeneration tower 86 can be less affected by the generation status of the recovered ammonia water in the ammonia recovery section 60.

[0051] The ship 1 of the above embodiment further includes an ammonia-removed water tank 92 for storing the ammonia-removed water separated by the regeneration tower 86, an ammonia-removed water delivery pump 93 for pumping out the ammonia-removed water from the ammonia-removed water tank 92, a removed water return line 94 for returning the ammonia-removed water in the ammonia-removed water tank 92 to the regeneration tower 86, and an overboard discharge line 95 for discharging the ammonia-removed water in the ammonia-removed water tank 92 overboard. In this manner, when the ammonia concentration of the ammonia-removed water is high, the ammonia-removed water can be returned to the regeneration tower 86 to separate ammonia vapor again. When the ammonia concentration of the ammonia-removed water has decreased to a level at which it can be discharged into the ocean, the ammonia-removed water can be discharged overboard.

[0052] The ship 1 of the above embodiment further includes an inert gas supplying device 50 that supplies an inert gas to the fuel flow passage of the combustion device 8 to purge fuel ammonia remaining in the fuel flow passage. Then, the ammonia recovery unit 60 absorbs the purged fuel ammonia into water and recovers it as recovered ammonia water. In this manner, the fuel ammonia purged with the inert gas can be used as the fuel ammonia for driving the combustion device 8. Therefore, it is possible to reduce the waste of the fuel ammonia, and thus to suppress an increase in the size of the ammonia tank 10.

[0053] <Modifications of the embodiment> FIG. 4 is a diagram corresponding to FIG. 3 in a modified example of the embodiment of the present disclosure. In the above-described embodiment, the ammonia gas separated in the gas-liquid separation unit 88 and dehumidified by the ammonia gas dehumidifier 90 is liquefied by the ammonia gas recovery and reuse unit (ammonia gas liquefaction unit) 91 and supplied to the ammonia tank 10. However, the destination of the ammonia gas separated in the gas-liquid separation unit 88 and dehumidified by the ammonia gas dehumidifier 90 is not limited to the ammonia gas recovery and reuse unit (ammonia gas liquefaction unit) 91. For example, as shown in FIG. 4, the dehumidified gas supply line 109 may be connected to the ammonia reuse unit 96 or the ammonia incineration unit 97 instead of the ammonia gas recovery and reuse unit (ammonia gas liquefaction unit) 91. The ammonia reuse unit 96 reuses the ammonia gas sent through the dehumidified gas supply line 109. In the ammonia reuse unit 96, the ammonia gas may be reused as it is in the gaseous state, or may be reused by compressing or liquefying the ammonia gas. The ammonia reuse unit 96 may be, for example, a denitrification device or a hydrogen generation device. The ammonia incineration section 97 incinerates the ammonia gas fed through the dehumidified gas supply line 109 in a gaseous state. According to the modified example of the above embodiment, the ammonia gas separated in the gas-liquid separation section 88 can be reused in various ammonia reuse sections 96 other than the combustion device 8, or incinerated in the ammonia incineration section 97.

[0054] In the modified example of the above embodiment, the case where either the ammonia reuse section 96 or the ammonia incineration section 97 is provided has been described, but at least one of the ammonia reuse section 96 and the ammonia incineration section 97 may be provided. For example, both the ammonia reuse section 96 and the ammonia incineration section 97 may be provided. In this case, the connection destination of the dehumidified gas supply line 109 may be configured to be switchable between the ammonia reuse section 96 and the ammonia incineration section 97 as necessary, or the dehumidified gas supply line 109 may be branched and connected to the ammonia reuse section 96 and the ammonia incineration section 97, respectively.

[0055] Furthermore, at least two of the ammonia gas recovery and reuse section (ammonia gas liquefaction section) 91 of the first embodiment, the ammonia reuse section 96 of the above-mentioned modified example, and the ammonia incineration section 97 of the above-mentioned modified example may be provided. In this case, similarly to the above, the connection destination of the dehumidified gas supply line 109 may be selectable from at least two of the ammonia gas recovery and reuse section (ammonia gas liquefaction section) 91, the ammonia reuse section 96, and the ammonia incineration section 97 as necessary, or the dehumidified gas supply line 109 may be branched and connected to at least two of the ammonia gas recovery and reuse section (ammonia gas liquefaction section) 91, the ammonia reuse section 96, and the ammonia incineration section 97.

[0056] Other Embodiments Although the embodiments of the present disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like that do not depart from the gist of the present disclosure are also included. In the above embodiment, a case has been described in which the ammonia recovered by the ammonia recovery unit 60 is fuel ammonia purged from the distribution path R of the combustion device 8. However, the ammonia recovered by the ammonia recovery unit 60 is not limited to fuel ammonia purged from the distribution path R. The ammonia recovered by the ammonia recovery unit 60 may be any ammonia used in the ship 1.

[0057] In the above embodiment, the combustion device 8 is a main unit that uses ammonia as fuel. However, the combustion device 8 is not limited to a device that burns only ammonia, and may be, for example, a combustion device 8 that can switch between ammonia and a fuel other than ammonia (for example, heavy oil, etc.).

[0058] In the above embodiment, the recovered ammonia water tank 70 is provided. However, the recovered ammonia water tank 70 may be omitted. In this case, the recovered ammonia water recovered by the ammonia recovery unit 60 may be introduced into the regeneration tower 86.

[0059] In the above embodiment, the case where the exhaust heat of the combustion device 8 is used in the regenerator 86 has been described, but thermal energy supplied from a heat source other than the combustion device 8 may also be used. Furthermore, although the case has been described where steam is generated using heat recovered by the exhaust gas economizer 81, a heat medium other than steam may be used as the heat medium.

[0060] In the above embodiment, the case where the separated liquid reflux section 89 includes the reflux pump 107 has been described, but as long as it is possible to send the separated liquid to the regenerator 86, the configuration is not limited to including the reflux pump 107. For example, if the separated liquid can move to the regenerator 86 by its own weight, the reflux pump 107 may be omitted. Similarly, in the above embodiment, a case has been described in which the recovered ammonia water delivery pump 85 is provided in the recovered ammonia water supply line 84, but if the recovered ammonia water can be sent to the regeneration tower 86, the recovered ammonia water delivery pump 85 may be omitted.

[0061] In the above embodiment, a configuration has been described in which the ammonia-removed water can be returned to the regeneration tower 86. However, if the ammonia concentration in the ammonia-removed water is at a level that allows it to be constantly discharged into the ocean, the ammonia-removed water does not need to be allowed to be returned to the regeneration tower 86.

[0062] <Additional Notes> The ship 1 described in the embodiment can be understood, for example, as follows.

[0063] (1) According to the first aspect, the ship 1 includes an ammonia recovery section 60 that absorbs ammonia into water and recovers it as recovered ammonia water, a regeneration tower 86 that heats the recovered ammonia water and separates the recovered ammonia water into ammonia-removed water and ammonia vapor, a gas-liquid separation section 88 that separates the ammonia vapor separated in the regeneration tower 86 into ammonia gas and separated liquid, and a separated liquid reflux section 89 that refluxes the separated liquid to the regeneration tower 86.

[0064] As a result, in the process of extracting ammonia from the recovered ammonia water, the ammonia vapor is separated into ammonia gas and a separated liquid by the gas-liquid separation unit 88, and this separated liquid can be returned to the regeneration tower 86, which separates the ammonia into ammonia-removed water and ammonia vapor, and processed again. Therefore, it is possible to reduce the installation space for piping inside the hull 2 ​​compared to, for example, a case in which the separated liquid is used as water for absorbing ammonia in the ammonia recovery unit 60. Furthermore, since it is not necessary to discharge the separated liquid outside the ship, a device for neutralizing or diluting the ammonia contained in the separated liquid is not required. Therefore, it is possible to prevent the size of the hull 2 ​​from increasing while recovering ammonia as recovered ammonia water.

[0065] (2) The ship 1 according to the second aspect is the ship of (1), and includes an ammonia tank 10 provided in the hull in which the ammonia is stored, and a combustion device 8 driven by the ammonia stored in the ammonia tank 10, and the regeneration tower 86 heats the recovered ammonia water by utilizing exhaust heat from the combustion device 8, and separates the recovered ammonia water into the ammonia-removed water and the ammonia vapor. The combustion device 8 may be, for example, an internal combustion engine used in a main engine and a generator, or a boiler.

[0066] As a result, in the ship 1 equipped with a combustion device 8 that uses ammonia as fuel, the exhaust heat of the combustion device 8 can be effectively utilized when separating ammonia from the recovered ammonia water. In addition, the separated ammonia can be used as fuel ammonia for the combustion device 8.

[0067] (3) The ship 1 according to a third aspect is the ship of (2), and includes an exhaust gas economizer 81 that recovers heat from the exhaust gas of the combustion device 8, a steam generating unit 82 that generates steam from the heat recovered by the exhaust gas economizer 81, and a heater unit 83 that uses the steam generated by the steam generating unit 82 to heat the liquid stored in the lower part of the regeneration tower 86.

[0068] This allows the heat recovered by the exhaust gas economizer 81 to be transferred to the liquid stored in the lower part of the regenerator 86, using the steam as a heat medium. Therefore, when the ship 1 has the exhaust gas economizer 81, the exhaust heat of the combustion device 8 can be easily utilized in the regenerator 86.

[0069] (4) The ship 1 according to a fourth aspect is the ship of (2) or (3) and is provided with an inert gas supply device 50 that supplies an inert gas to the fuel flow path of the combustion device 8 to purge the fuel ammonia remaining in the fuel flow path, and the ammonia recovery section 60 absorbs the purged fuel ammonia into water and recovers it as recovered ammonia.

[0070] This makes it possible to use the fuel ammonia purged with the inert gas as the fuel ammonia for driving the combustion device 8. Therefore, it is possible to reduce the waste of the fuel ammonia, and thus to suppress an increase in the size of the ammonia tank 10.

[0071] (5) The ship 1 according to a fifth aspect is the ship of (2) to (4), further comprising an ammonia gas recovery and reuse unit 91 that liquefies the ammonia gas separated in the gas-liquid separation unit 88 and supplies the liquefied ammonia gas to the ammonia tank 10.

[0072] This allows the ammonia tank 10 to be used as a tank for storing the ammonia extracted from the recovered ammonia water. Therefore, a dedicated tank for storing the ammonia liquefied in the ammonia gas recovery and reuse unit 91 can be omitted.

[0073] (6) The ship 1 according to a sixth aspect is a ship of (2) to (4), further comprising at least one of an ammonia recycling section 96 that reuses the ammonia gas separated in the gas-liquid separation section 88, and an ammonia incineration section 97 that incinerates the ammonia gas separated in the gas-liquid separation section 88.

[0074] As a result, the ammonia gas separated in the gas-liquid separation section 88 can be reused by the ammonia reuse section 96 or incinerated by the ammonia incineration section 97.

[0075] (7) The ship 1 according to a seventh aspect is any one of the ships (1) to (6), further comprising a condenser 87 that cools the ammonia vapor separated in the regeneration tower 86 to reduce the volume of the ammonia vapor. This enables the gas-liquid separation process in the gas-liquid separator 88 to be carried out efficiently.

[0076] (8) The ship 1 in the eighth aspect is any one of the ships (1) to (7), and the separated liquid return section 89 is provided with a return line connecting the gas-liquid separation section 88 and the regenerator 86, and a return pump 107 that pumps the separated liquid toward the regenerator 86. This allows the reflux pump 107 to actively send the separated liquid separated in the gas-liquid separation section 88 to the regeneration tower 86.

[0077] (9) The ship 1 according to a ninth aspect is any one of the ships (1) to (8), and includes a recovered ammonia water tank 70 for storing the recovered ammonia water recovered by the ammonia recovery section 60, a recovered ammonia water supply line 84 connecting the recovered ammonia water tank 70 and the regeneration tower 86, and a recovered ammonia water delivery pump 85 provided on the recovered ammonia water supply line 84 for delivering the recovered ammonia water from the recovered ammonia water tank 70 to the regeneration tower 86.

[0078] This allows the recovered ammonia water recovered by the ammonia recovery section 60 to be temporarily stored in the recovered ammonia water tank 70. The recovered ammonia water stored in the recovered ammonia water tank 70 can then be sent to the regeneration tower 86 by the recovered ammonia water delivery pump 85. This makes it possible to reduce the effect of the generation status of the recovered ammonia water in the ammonia recovery section 60 on the process of separating the recovered ammonia water performed in the regeneration tower 86.

[0079] (10) The ship 1 according to the tenth aspect is any one of the ships (1) to (9), and further includes an ammonia-removed water tank 92 for storing the ammonia-removed water separated by the regeneration tower 86, an ammonia-removed water delivery pump 93 for pumping out the ammonia-removed water from the ammonia-removed water tank 92, a removed water return line 94 for returning the ammonia-removed water in the ammonia-removed water tank 92 to the regeneration tower 86, and an overboard discharge line 95 for discharging the ammonia-removed water in the ammonia-removed water tank 92 overboard.

[0080] As a result, when the ammonia concentration in the ammonia-removed water is high, the ammonia-removed water can be returned to the regeneration tower 86 to separate ammonia vapor again. When the ammonia concentration in the ammonia-removed water has decreased to a level at which it can be discharged into the ocean, the ammonia-removed water can be discharged overboard. [Explanation of symbols]

[0081] 1...ship 2...hull 4...superstructure 5A, 5B...shipside 6...ship bottom 7...upper deck 8...combustion device 10...ammonia tank 20...piping system 20p...area to be purged 21...supply pipe 22...return pipe 23, 24...on-off valve 30...vent post 38...vent pipe 38A...upstream vent pipe 38B...downstream vent pipe 40...ammonia buffer tank 50...inert gas supply device 51...inert gas supply section 52...inert gas supply pipe 53...inert gas supply valve 60...ammonia recovery section 70...recovered ammonia water tank 71...recovery pipe 72...recovery pipe on-off valve 80...exhaust pipe 81...exhaust gas economizer 81a...piping 81b...pump 82...steam generation section 82a...steam supply pipe 83...heater section 84...recovered ammonia water supply line 85...Recovered ammonia water delivery pump 86...Regeneration tower 87...Condenser 88...Gas-liquid separation section 89...Separated liquid reflux section 90...Ammonia gas dehumidifier 91...Ammonia gas recovery and reuse section 92...Ammonia removed water tank 93...Ammonia removed water delivery pump 94...Removed water reflux line 95...Overboard discharge line 96...Ammonia reuse section 97...Ammonia incineration section 101...Circulation piping 102...Circulation pump 103...Heater body 104...Ammonia vapor line 105...Reflux line 106...Reflux on-off valve 107...Reflux pump 108...Ammonia gas supply line 109...Dehumidified gas supply line 110...Ammonia return line 111,112...On-off valve 115...Ammonia fuel supply line 116...Feed pump 117...Ammonia pressure pump 118...Ammonia heat exchanger 119...Buffer tank vent pipe G: Exhaust gas R: Distribution route

Claims

1. an ammonia tank provided in the hull and storing ammonia; a combustion device driven by the ammonia stored in the ammonia tank; an ammonia recovery section that absorbs the ammonia into water and recovers it as recovered ammonia water; a regeneration tower for heating the recovered ammonia water and separating the recovered ammonia water into ammonia-removed water and ammonia vapor; A gas-liquid separation section that separates the ammonia vapor separated in the regeneration tower into ammonia gas and a separated liquid; A separated liquid reflux section that refluxes the separated liquid to the regeneration tower; an inert gas supplying device that supplies an inert gas to a fuel flow path of the combustion device to purge fuel ammonia remaining in the fuel flow path; an ammonia-removed water tank for storing the ammonia-removed water separated by the regeneration tower; a removed water reflux line for refluxing the ammonia removed water in the ammonia removed water tank to the regeneration tower; an ammonia-removed water delivery pump provided in the removed water return line and configured to deliver the ammonia-removed water from the ammonia-removed water tank; an overboard discharge line that branches off from the removed water return line on a side closer to the regeneration tower than the ammonia-removed water delivery pump and discharges the ammonia-removed water in the ammonia-removed water tank outside the ship to be discharged into the ocean; Equipped with The ammonia recovery section absorbs the purged fuel ammonia in water and recovers it as recovered ammonia. ship.

2. The regeneration tower uses exhaust heat from the combustion device to heat the recovered ammonia water and separates the recovered ammonia water into the ammonia-removed water and the ammonia vapor.

2. The watercraft of claim 1.

3. an exhaust gas economizer for recovering heat from the exhaust gas of the combustion device; a steam generating unit that generates steam from the heat recovered by the exhaust gas economizer; A heater unit that uses the steam generated by the steam generating unit to heat the liquid stored in the lower part of the regeneration tower.

3. The watercraft of claim 2.

4. The ammonia gas recovery and reuse unit further comprises an ammonia gas recovery and reuse unit that liquefies the ammonia gas separated in the gas-liquid separation unit and supplies the liquefied ammonia gas to the ammonia tank. A vessel as claimed in any one of claims 1 to 3.

5. The system further includes at least one of an ammonia recycling unit that reuses the ammonia gas separated in the gas-liquid separation unit, and an ammonia incineration unit that incinerates the ammonia gas separated in the gas-liquid separation unit. A vessel as claimed in any one of claims 1 to 4.

6. The ship according to any one of claims 1 to 5, further comprising a condenser that cools the ammonia vapor separated in the regeneration tower to reduce a volume of the ammonia vapor.

7. The separated liquid reflux section includes a reflux line that connects the gas-liquid separation section and the regeneration tower, and a reflux pump that pumps the separated liquid toward the regeneration tower. A watercraft as claimed in any one of claims 1 to 6.

8. a recovered ammonia water tank that stores the recovered ammonia water recovered by the ammonia recovery unit; a recovered ammonia water supply line connecting the recovered ammonia water tank and the regeneration tower; a recovered ammonia water delivery pump provided in the recovered ammonia water supply line for delivering the recovered ammonia water from the recovered ammonia water tank to the regeneration tower. A vessel as claimed in any one of claims 1 to 7.

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