Ships

Abstract

To provide a vessel capable of recovering ammonia as ammonia water, suppressing discharging of recovered ammonia out of the vessel by recycling the recovered ammonia, and suppressing enlargement of a hull.SOLUTION: The vessel comprises: a combustion device that discharges exhaust gas by combusting fuel; an ammonia recovery unit that absorbs ammonia in water and recovers it as recovered ammonia; a recovered ammonia water tank that stores the recovered ammonia water recovered by the ammonia recovery unit; a denitration device that executes denitration treatment for the exhaust gas discharged from the combustion device; a denitration ammonia water tank that stores denitration ammonia water as a catalyst of the denitration device; and a recovered ammonia water supply line that supplies the recovered ammonia water of the recovered ammonia water tank to the denitration ammonia water tank.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. In the recovery device of Patent Document 2, the ammonia water stored in the ammonia water tank is distilled, and the ammonia gas obtained by the distillation is dehumidified and liquefied to produce high-purity ammonia. [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] However, in order to apply a recovery device such as that described in Patent Document 2 to a ship, it is necessary to secure additional installation space within the hull of the ship, which poses the problem of increasing the size of the hull. 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 the ammonia water tank exceeds the upper limit, it becomes necessary to neutralize or dilute the ammonia contained in the water before discharging it overboard, which poses the problem of the need for separate equipment for neutralization or dilution. 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 while reducing the discharge of recovered ammonia overboard by reusing the recovered ammonia, thereby preventing the ship from becoming larger. [Means for solving the problem]

[0006] In order to solve the above problems, the ship of the present disclosure has a structure in which the ship is sunk by burning fuel. Propelling the ship and Emitting exhaust gases Internal combustion engine and, an ammonia tank in which fuel ammonia, which is a fuel for the internal combustion engine, is stored; a fuel ammonia supply line that supplies the liquid fuel ammonia stored in the ammonia tank to the denitration ammonia water tank; an inert gas supply device that supplies an inert gas to a distribution path through which the fuel for the internal combustion engine flows, to purge the fuel ammonia remaining in the distribution path; an ammonia recovery unit that absorbs the ammonia into water and recovers it as recovered ammonia water; a recovered ammonia water tank that stores the recovered ammonia water recovered by the ammonia recovery unit; Internal combustion engine the denitration system includes a denitration device that performs a denitration treatment on exhaust gas discharged from a denitration plant, a denitration ammonia water tank that stores denitration ammonia water used as a reducing agent in the denitration device, and a recovered ammonia water supply line that supplies the recovered ammonia water in the recovered ammonia water tank to the denitration ammonia water tank. Effect of the Invention

[0007] According to the ship of the present disclosure, by recovering ammonia as ammonia water and reusing the recovered ammonia, it is possible to reduce the discharge of recovered ammonia overboard and prevent the ship from becoming larger. [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 denitration ammonia water tank of the denitration device according to 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 within the hull 2, closer to the bow 3a in the bow-stern direction FA than the superstructure 4 and below the upper deck 7.

[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 and recovers it as recovered ammonia water. The ammonia recovery unit 60 of this embodiment is disposed on the upper deck 7 on the stern 3b side of 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. Water (e.g., fresh water) stored in a water tank (not shown) provided in the hull 2 ​​is supplied to this ammonia recovery unit 60. 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 a fuel ammonia supply line 85 (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 93 and an ammonia heat exchanger 94 (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 dry 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 when the combustion device 8 is switched over to a fuel or when the combustion device 8 is stopped in an emergency. In other words, the valve 53 is operated from a closed state to an open state when the fuel ammonia remaining in the purging target area 20p is purged. When such purging is performed, the on-off valve 23 is first closed and the supply pipe 21 is 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. Then, when the inert gas is supplied from the inert gas supply unit 51, the fuel ammonia in the pipe of the purging target area 20p is pushed out by the inert gas to the ammonia buffer tank 40 side, and the liquid fuel ammonia is collected in the ammonia buffer tank 40. After that, the on-off valve 24 is closed and the return pipe 22 is blocked. As a result, the inert gas and the fuel ammonia remaining in the flow path R are led to the vent pipe 38. Here, the on-off valve 24 is closed when most of the remaining fuel ammonia is recovered in the ammonia buffer tank 40. Such a state can be detected, for example, by using various sensors, timers, etc. Although the case where the remaining fuel ammonia is recovered in the ammonia buffer tank 40 has been described, the present invention is not limited to this configuration. For example, the on-off valves 23 and 24 may be simultaneously closed to simultaneously block the supply pipe 21 and the return pipe 22, and then the inert gas may be supplied by the inert gas supply unit 51.

[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 connects the purged region 20p of the recovery pipe 71 (flow path R) 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 of the denitrification equipment) FIG. 3 is a diagram showing a piping system around a denitration ammonia water tank of a denitration apparatus according to an embodiment of the present disclosure. As shown in FIG. 3, the ship 1 of this embodiment further includes an exhaust pipe 80, a denitration device 81, a denitration ammonia water tank 82, a denitration ammonia water supply line 83, a recovered ammonia water supply line 84, and a fuel ammonia supply line 85.

[0028] The exhaust pipe 80 guides the exhaust gas G discharged from the combustion device 8 to the outside of the hull 2. The exhaust gas G flowing through this exhaust pipe 80 immediately after being discharged from the combustion device 8 contains nitrogen oxides. The denitration device 81 performs a denitration process on the exhaust gas G discharged from the combustion device 8. This denitration device 81 is a selective catalytic reduction denitration device (SCR) that converts nitrogen oxides into nitrogen and water using a catalyst. This denitration device 81 is provided midway through the exhaust pipe 80, and brings the exhaust gas G sprayed with ammonia water for denitration into contact with a catalyst (not shown). The exhaust gas G that has been subjected to the denitration process is released into the atmosphere, for example, through a funnel (not shown) provided on the hull 2.

[0029] The denitration ammonia water tank 82 stores the denitration ammonia water used in the denitration device 81. Here, the denitration ammonia water is ammonia water adjusted to a predetermined ammonia concentration (for example, several tens of percent) required for use as a reducing agent in the denitration device 81. The denitration ammonia water tank 82 of this embodiment includes a circulation pipe 86 for stirring the denitration ammonia water and a stirring pump 87. Furthermore, the circulation pipe 86 is provided with a concentration meter 88 for measuring the ammonia concentration of the denitration ammonia water stored in the denitration ammonia water tank 82. Note that the denitration ammonia water tank 82 may be provided with a water level meter or the like so that the amount of the denitration ammonia water stored therein can be measured. Note that the circulation pipe 86 and the stirring pump 87 are not provided, and the denitration ammonia water tank 82 may be provided with a stirrer of a different type. Also, the above-mentioned configuration for stirring the denitration ammonia water may be provided as necessary, and may be omitted, for example. In this case, a concentration meter 88 for measuring the ammonia concentration of the denitration ammonia water may be provided in the denitration ammonia water tank 82 .

[0030] The denitration ammonia water supply line 83 forms a flow path for supplying the denitration ammonia water stored in the denitration ammonia water tank 82 to the denitration device 81. The denitration ammonia water supply line 83 is provided with a denitration ammonia water pump 89.

[0031] The recovered ammonia water supply line 84 forms a flow path for supplying the recovered ammonia water in the recovered ammonia water tank 70 to the denitration ammonia water tank 82. The recovered ammonia water supply line 84 is provided with a recovered ammonia water pump 90. Here, the ammonia concentration of the recovered ammonia water stored in the recovered ammonia water tank 70 is lower (for example, about several ppm to several %) than the ammonia concentration of the above-mentioned denitration ammonia water.

[0032] The fuel ammonia supply line 85 includes a first line 85A that supplies the fuel ammonia stored in the ammonia tank 10 to the ammonia buffer tank 40, and a second line 85B that supplies the fuel ammonia stored in the ammonia tank 10 to the denitrification ammonia water tank 82. As described above, the fuel ammonia is liquefied ammonia. Therefore, the ammonia concentration of the fuel ammonia is higher than the ammonia concentration of the recovered ammonia water. Note that, although the second line 85B in this embodiment is exemplified as being branched and connected to the first line 85A, the second line 85B may be capable of supplying the fuel ammonia to the denitrification ammonia water tank 82, and may be configured to connect the ammonia tank 10 and the denitrification ammonia water tank 82, for example.

[0033] In the present embodiment, the second line 85B is provided with a flow rate control valve 91 capable of adjusting the flow rate of the fuel ammonia flowing from the first line 85A to the second line 85B. The flow rate control valve 91 is capable of gradually adjusting the valve opening from a fully closed state to a fully open state. The valve opening of the flow rate control valve 91 may be manually operated by an operator, but may also be automatically adjusted by a control device (not shown) based on the measurement result of the ammonia concentration by the concentration meter 88, for example.

[0034] In the first line 85A in this embodiment, a feed pump 92 for feeding fuel ammonia toward the combustion device 8 is provided on a side closer to the ammonia tank 10 than the branch point P1 of the second line 85B. In other words, the second line 85B illustrated in this embodiment branches off from the first line 85A between the feed pump 92 and the ammonia buffer tank 40. Note that a pump for feeding fuel ammonia toward the denitrification ammonia water tank 82 may be provided in the second line 85B.

[0035] Further, the supply pipe 21 of this embodiment is provided with an ammonia pressure pump 93 and an ammonia heat exchanger 94, which are not shown in FIG. 2. The ammonia pressure pump 93 pressurizes the fuel ammonia supplied from the ammonia buffer tank 40 to the combustion device 8. The ammonia heat exchanger 94 adjusts the temperature of the fuel ammonia pressurized by the ammonia pressure pump 93. The ammonia buffer tank 40 and the ammonia recovery section 60 of this embodiment are connected by a buffer tank vent pipe 95, 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.

[0036] (Action and effect) The ship 1 of the above embodiment is equipped with a combustion device 8 that discharges exhaust gas G by burning fuel, an ammonia recovery section 60 that absorbs ammonia into water and recovers it as recovered ammonia water, a recovered ammonia water tank 70 that stores the recovered ammonia water recovered in the ammonia recovery section 60, a denitration device 81 that performs a denitration process on the exhaust gas G discharged from the combustion device 8, a denitration ammonia water tank 82 that stores denitration ammonia water used as a reducing agent in the denitration device 81, and a recovered ammonia water supply line 84 that supplies the recovered ammonia water from the recovered ammonia water tank 70 to the denitration ammonia water tank 82.

[0037] According to such a ship 1, the recovered ammonia water recovered by the ammonia recovery section 60 can be supplied to the denitration ammonia water tank 82 through the recovered ammonia water supply line 84. Therefore, the recovered ammonia water is used in the denitration ammonia water tank 82 to produce denitration ammonia water, and the denitration ammonia water in the denitration ammonia water tank 82 can be used as a reducing agent for the denitration device 81. This allows the recovered ammonia water to be effectively used, eliminating the need for equipment to treat the recovered ammonia water and making it possible to prevent the size of the hull 2 ​​from increasing while still allowing ammonia to be recovered as ammonia water.

[0038] The ship 1 of the above embodiment further includes an ammonia tank 10 in which fuel ammonia, which is fuel for the combustion device 8, is stored, and a fuel ammonia supply line 85 that supplies the fuel ammonia in the ammonia tank 10 to the denitrification ammonia water tank 82. Therefore, by mixing the recovered ammonia water supplied to the denitration ammonia water tank 82 with fuel ammonia having a higher ammonia concentration than the denitration ammonia water, it is possible to produce denitration ammonia water having a higher ammonia concentration than the recovered ammonia water.

[0039] The combustion device 8 of the ship 1 in the above embodiment is a main engine that propels the hull 2, and the ship 1 includes an inert gas supply device 50 that supplies an inert gas to a flow path through which fuel of the main engine flows, to purge fuel ammonia remaining in the flow path. The ammonia recovery unit 60 absorbs the purged fuel ammonia into water and recovers it as recovered ammonia water. That is, when the ship 1 is a so-called ammonia-fueled ship that sails using ammonia as fuel, the fuel ammonia remaining in the distribution route R can be purged and recovered as recovered ammonia water by the ammonia recovery unit 60. Then, since this recovered ammonia water is used as part of the ammonia water for denitration for performing a denitration treatment on the exhaust gas G of the main engine, it becomes possible to effectively use the purged fuel ammonia for the main engine as a reducing agent for the denitration device 81 for the main engine. Therefore, the cost of generating ammonia water for denitration can be reduced compared to the case where ammonia for generating ammonia water for denitration is separately prepared.

[0040] In addition, in the ship 1, since the fuel ammonia can be diluted with the recovered ammonia water, the amount of water used in the fresh water tank provided in the hull 2 ​​can be reduced when producing ammonia water for denitration, making it possible to provide a sufficient amount of fresh water. This makes it possible to reduce the volume of the fresh water tank and the capacity of the fresh water production system, and thus makes it possible to prevent the size of the hull 2 ​​from increasing.

[0041] (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.

[0042] In the above embodiment, the combustion device 8 is described as a main unit that uses ammonia as fuel. However, the combustion device 8 may be any device that burns fuel to discharge exhaust gas G, and may be, for example, a combustion device that burns a fuel other than ammonia to discharge exhaust gas G, or a combustion device that can switch between ammonia and a fuel other than ammonia.

[0043] In the above embodiment, the case where the fuel ammonia in the ammonia tank 10 is supplied to the denitration ammonia water tank 82 has been described. However, liquefied ammonia may be supplied to the denitration ammonia water tank 82 from a tank provided separately from the ammonia tank 10.

[0044] <Additional Notes> The ship 1 described in the embodiment can be understood, for example, as follows.

[0045] (1) The ship 1 according to the first embodiment includes a combustion device 8 that discharges exhaust gas G by burning fuel, an ammonia recovery section 60 that absorbs ammonia into water and recovers it as recovered ammonia water, a recovered ammonia water tank 70 that stores the recovered ammonia water recovered in the ammonia recovery section 60, a denitration device 81 that performs a denitration process on the exhaust gas G discharged from the combustion device 8, a denitration ammonia water tank 82 that stores denitration ammonia water used as a reducing agent in the denitration device 81, and a recovered ammonia water supply line 84 that supplies the recovered ammonia water from the recovered ammonia water tank 70 to the denitration ammonia water tank 82. The combustion device 8 may be, for example, an internal combustion engine used in a main engine and a generator, or a boiler.

[0046] With this configuration, the recovered ammonia water recovered by the ammonia recovery section 60 can be supplied to the denitration ammonia water tank 82 through the recovered ammonia water supply line 84. Therefore, the recovered ammonia water is used in the denitration ammonia water tank 82 to produce denitration ammonia water, and this denitration ammonia water in the denitration ammonia water tank 82 can be used as a reducing agent for the denitration device 81. This allows the recovered ammonia water to be used effectively, eliminating the need for equipment to treat the recovered ammonia water and making it possible to prevent the size of the hull 2 ​​from increasing while still allowing the ammonia to be recovered as ammonia water.

[0047] (2) The ship 1 according to a second aspect is the ship 1 of (1), and includes an ammonia tank 10 in which fuel ammonia, which is fuel for the combustion device 8, is stored, and a fuel ammonia supply line 85 that supplies the fuel ammonia in the ammonia tank 10 to the denitrification ammonia water tank 82.

[0048] With this configuration, the recovered ammonia water supplied to the denitration ammonia water tank 82 can be mixed with fuel ammonia having a higher ammonia concentration than the denitration ammonia water to produce denitration ammonia water having a higher ammonia concentration than the recovered ammonia water.

[0049] (3) The ship 1 according to a third aspect is the ship 1 of (1) or (2), wherein the combustion device 8 is a main engine that propels the hull 2, and is equipped with an inert gas supply device 50 that supplies inert gas to a distribution path R through which fuel for the main engine flows, to purge the fuel ammonia remaining in the distribution path R, and the ammonia recovery section 60 absorbs the purged fuel ammonia into water and recovers it as recovered ammonia water.

[0050] As a result, when the ship 1 is a so-called ammonia-fueled ship that sails using ammonia as fuel, the fuel ammonia remaining in the distribution route R can be purged and recovered as recovered ammonia water by the ammonia recovery unit 60. And, since this recovered ammonia water is used as part of the ammonia water for denitration for performing a denitration treatment on the exhaust gas G of the main engine, it becomes possible to effectively use the purged fuel ammonia for the main engine as a reducing agent for the denitration device 81 for the main engine. Therefore, the cost of generating ammonia water for denitration can be reduced compared to the case where ammonia for generating ammonia water for denitration is separately prepared. [Explanation of symbols]

[0051] 1...ship 2...hull 4...superstructure 5A, 5B...shipside 6...ship bottom 7...upper deck 8...combustion system 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 system 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...denitrification system 82...ammonia water tank for denitrification 83...ammonia water supply line for denitrification 84...recovered ammonia water supply line 85...fuel ammonia supply line 85A...first line 85B... Second line 86... Circulation piping 87... Mixing pump 88... Concentration meter 89... Denitrification ammonia water pump 90... Recovered ammonia water pump 91... Flow control valve 92... Feed pump 93... Ammonia pressure pump 94... Ammonia heat exchanger 95... Buffer tank vent pipe G... Exhaust gas R... Distribution route

Claims

[Claim 1] An internal combustion engine that burns fuel to propel the ship and emits exhaust gas; An ammonia tank in which fuel ammonia which is a fuel for the internal combustion engine is stored; a fuel ammonia supply line that supplies the fuel ammonia stored in the ammonia tank to the denitration ammonia water tank; an inert gas supplying device that supplies an inert gas to a flow path through which fuel of the internal combustion engine flows, thereby purging the fuel ammonia remaining in the flow path; an ammonia recovery section that absorbs the fuel ammonia purged from the distribution path into water and recovers it as recovered ammonia water; a recovered ammonia water tank for storing the recovered ammonia water recovered in the ammonia recovery section; a denitration device that performs a denitration treatment on exhaust gas discharged from the internal combustion engine; a denitration ammonia water tank for storing denitration ammonia water used as a reducing agent for the denitration device; a recovered ammonia water supply line that supplies the recovered ammonia water in the recovered ammonia water tank to the denitrification ammonia water tank; A vessel equipped with:

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