KR20230172056A - Ammonia fuel vessel - Google Patents

Abstract

An ammonia fueled vessel is provided by one embodiment of the present invention.
An ammonia fuel ship according to an embodiment of the present invention includes a hull, a fuel tank installed on the hull and storing liquid ammonia, and liquid ammonia or ammonia generated by vaporizing liquid ammonia from a first fuel supply pipe connected to the fuel tank. A boiler that receives the supply and combusts it to generate steam, a first post-treatment device installed on the first exhaust pipe connected to the boiler to reduce at least one of nitrous oxide and nitrogen oxide contained in the exhaust gas generated from the boiler, and a fuel tank. A first reducing agent supply pipe connects the first post-processing device to supply liquid ammonia or ammonia inside the fuel tank to the first post-processing device as a reducing agent, and receives liquid ammonia or ammonia from a second fuel supply pipe connected to the fuel tank. It may include a combustion engine, and a recovery pipe for recovering liquid ammonia or ammonia remaining inside the first reducing agent supply pipe and supplying it to the engine or boiler.

Description

Ammonia fuel vessel

The present invention relates to ammonia-fueled ships, and more specifically, to a reducing agent supply pipe when the operation of the after-treatment device for reducing at least one of nitrous oxide and nitrogen oxide contained in exhaust gas discharged from an ammonia-driven boiler is stopped. This relates to an ammonia-fueled ship that can effectively dispose of residual ammonia.

In general, various engines installed on ships generate power by burning fossil fuels, and exhaust gases generated during the combustion process of fuel contain nitrogen oxides, sulfur oxides, carbon dioxide, etc. As air pollution due to pollutants contained in exhaust gases increases, there is a demand for the development of eco-friendly ships that generate power using low-carbon or decarbonized fuels. Ammonia, which does not emit carbon dioxide when burned, is one of the next-generation eco-friendly fuels. It is emerging. Recently, attempts have been made to use ammonia fuel not only in engines but also in boilers.

Meanwhile, ammonia does not emit carbon dioxide when burned, but the emissions of nitrous oxide and nitrogen oxides are greater than those of fossil fuels, so it is essential to install a selective catalytic reduction reactor to reduce nitrous oxide and nitrogen oxides on the exhaust pipe. The selective catalytic reduction reactor reduces nitrous oxide and nitrogen oxides by passing exhaust gas mixed with a reducing agent through a catalyst layer installed inside the reactor, and ammonia can be used as a reducing agent. In a conventional ship using ammonia as fuel, when the operation of the selective catalytic reduction reactor is stopped, the residue in the pipe supplying ammonia to the selective catalytic reduction reactor is quickly purged and discharged into the atmosphere. However, since ammonia is a toxic substance and does not disperse instantly when released into the atmosphere, releasing ammonia into the atmosphere poses a safety issue. Accordingly, a method of dissolving ammonia in water to lower its concentration and then releasing it has been proposed, but it is difficult to dissolve a large amount of ammonia in a certain amount of water in the tank, and the pH of the water in which ammonia is dissolved is high, so it cannot be discharged as is into the sea. There are also problems that are difficult to deal with.

Republic of Korea Patent Publication No. 10-2022-0034270 (2022.03.18.)

The technical problem to be achieved by the present invention is to effectively remove ammonia remaining in the reducing agent supply pipe when the operation of the post-treatment device that reduces at least one of nitrous oxide and nitrogen oxide contained in the exhaust gas discharged from an ammonia-driven boiler is stopped. The goal is to provide ammonia fuel ships that can process it.

The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below.

An ammonia fuel ship according to an embodiment of the present invention for achieving the above technical problem includes a hull, a fuel tank installed on the hull and storing liquid ammonia, and a first fuel supply pipe connected to the fuel tank to supply liquid ammonia or A boiler that receives ammonia generated by vaporizing the liquid ammonia and burns it to generate steam, and is installed on a first exhaust pipe connected to the boiler and at least one of nitrous oxide and nitrogen oxide contained in the exhaust gas generated from the boiler. a first post-treatment device that reduces , and a first reducing agent supply pipe that connects the fuel tank and the first post-treatment device to supply the liquid ammonia or the ammonia inside the fuel tank as a reducing agent to the first after-treatment device. and an engine that receives the liquid ammonia or the ammonia from a second fuel supply pipe connected to the fuel tank and combusts it, and recovers the liquid ammonia or the ammonia remaining inside the first reducing agent supply pipe and supplies it to the engine or the boiler. Includes a return pipe that supplies

The ammonia fuel ship includes a urea tank that stores urea water inside, and

It further includes a urea water supply pipe connecting the urea water tank and the first post-treatment device to supply the urea water to the first post-treatment device, wherein the first post-treatment device is through the first reducing agent supply pipe. The liquid ammonia or the ammonia may be supplied as a reducing agent, or the urea water may be supplied as a reducing agent through the urea water supply pipe.

In the ammonia fuel ship, the first fuel supply pipe and the second fuel supply pipe further include a pretreatment device for preprocessing the liquid ammonia or the ammonia, and the recovery pipe is configured to provide the first fuel in front of the pretreatment device. It may include a first recovery pipe connected to the supply pipe, and a second recovery pipe connected to the second fuel supply pipe at the front of the pretreatment device.

The ammonia fuel vessel includes a second after-treatment device installed on a second exhaust pipe connected to the engine to reduce at least one of nitrous oxide and nitrogen oxide contained in the exhaust gas generated by the engine, and a second post-treatment device that branches off from the recovery pipe. It may further include a branch pipe for supplying the liquid ammonia or the ammonia as a reducing agent to the second post-treatment device.

The ammonia fuel ship further includes a second reducing agent supply pipe that connects the fuel tank and the second post-treatment device to supply the liquid ammonia or the ammonia inside the fuel tank as a reducing agent to the second after-treatment device, , the branch pipe may supply the liquid ammonia or the ammonia to the second reducing agent supply pipe.

The first post-processing device and the second post-processing device are respectively installed at a rear end of the selective catalytic reduction reactor for nitrous oxide and a selective catalytic reduction reactor for nitrous oxide to remove the nitrogen oxides. It may include a selective catalytic reduction reactor for oxides.

The selective catalytic reduction reactor for nitrous oxide includes at least one of cobalt (Co), rhodium (Rh), and cerium-cobalt complex oxide (Ce-Co-O) supported on a carrier made of aluminum oxide (Al ₂ O ₃ ). Including a catalyst, or a catalyst in which rhodium (Rh) is supported on a carrier made of aluminum oxide (Zn-Al ₂ O ₃ ) impregnated with zinc, or a catalyst in which iron (Fe) is supported on a carrier made of zeolite. , when the liquid ammonia or the ammonia is supplied as a reducing agent, the nitrous oxide can be reduced to nitrogen and oxygen.

The ammonia fuel vessel includes an exhaust gas circulation pipe branched from the first exhaust pipe to circulate exhaust gas generated from the boiler to the air supply pipe of the boiler, and an exhaust gas circulation pipe branched from the return pipe to exhaust the liquid ammonia or the ammonia. It may further include a water return pipe supplying to the gas circulation pipe.

According to the present invention, when the operation of the first after-treatment device installed on the first exhaust pipe connected to the boiler is stopped, the liquid ammonia or ammonia remaining in the first reducing agent supply pipe connected to the first after-treatment device is recovered and the running engine is used. Alternatively, it can be used as fuel for a boiler, or as a reducing agent in a second after-treatment device installed on the second exhaust pipe connected to the engine, or incinerated in the boiler, so ammonia can be effectively treated without a separate ammonia vent system, as well as improving space utilization within the ship. It can be increased.

1 is a diagram illustrating an ammonia-fueled ship according to an embodiment of the present invention.
Figure 2 is an enlarged view of the selective catalytic reduction reactor for nitrous oxide of Figure 1.
Figures 3 to 5 are operational diagrams for explaining the operation of an ammonia fuel ship.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. The present embodiments are merely provided to ensure that the disclosure of the present invention is complete and to be understood by those skilled in the art. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, with reference to FIGS. 1 to 5, an ammonia-fueled ship according to an embodiment of the present invention will be described in detail.

The ammonia fuel ship according to an embodiment of the present invention is a ship that uses ammonia as fuel. For example, ammonia can be supplied as fuel to engines and boilers to generate propulsion, electricity, steam, etc.

When the operation of the first after-treatment device installed on the first exhaust pipe connected to the boiler is stopped, the ammonia-fueled ship recovers the liquid ammonia or ammonia remaining in the first reducing agent supply pipe connected to the first after-treatment device, and the running engine or It is used as fuel in the boiler, as a reducing agent in the second post-processing device installed on the second exhaust pipe connected to the engine, or incinerated in the boiler, so ammonia can be treated effectively without a separate ammonia vent system and increases space utilization within the ship. There is a feature that allows you to do this.

Hereinafter, with reference to FIGS. 1 and 2, the ammonia fuel ship 1 will be described in more detail.

FIG. 1 is a diagram illustrating an ammonia-fueled ship according to an embodiment of the present invention, and FIG. 2 is an enlarged diagram illustrating the selective catalytic reduction reactor for nitrous oxide of FIG. 1.

The ammonia fuel ship (1) according to the present invention includes a hull (10), a fuel tank (20), a boiler (30), a first post-treatment device (40), a first reducing agent supply pipe (50a, 50b), and an engine (60). , and a recovery pipe 70.

The hull 10 forms the external shape of the ammonia fuel ship 1, and the outer surface is formed in a streamlined shape to minimize resistance due to seawater. The hull 10 is propelled by power generated by an engine 60, which will be described later, and at least one fuel tank 20 is installed therein.

The fuel tank 20 is a tank that stores liquid ammonia and may be formed as a membrane-type normal pressure tank in which the internal pressure is maintained constant. Liquid ammonia stored in the fuel tank 20 or ammonia generated by vaporizing liquid ammonia can be supplied to the boiler 30 and the engine 60, respectively.

The boiler 30 receives liquid ammonia or ammonia generated by vaporizing liquid ammonia from the first fuel supply pipe 31 connected to the fuel tank 20 and burns it to generate steam. For example, it may be an ammonia boiler. . Hereinafter, the structure in which the boiler 30 receives liquid ammonia and burns it to generate steam will be described in more detail. One end of the first fuel supply pipe 31 penetrates the fuel tank 20 and is connected to the low pressure pump 21 installed inside the fuel tank 20, and the other end extends outside the fuel tank 20 to connect to the boiler 30. can be connected A pretreatment device 32 is installed on the first fuel supply pipe 31 to preprocess liquid ammonia or ammonia, and the pretreatment device 32 heats liquid ammonia or ammonia by heat exchange with at least one of seawater, fresh water, and glycol water. It may contain one heater. Liquid ammonia or ammonia heated in the pretreatment device 32 is supplied to the boiler 30 through the first fuel supply pipe 31, and the boiler 30 supplies liquid ammonia or ammonia and air supply pipe 43. Steam is generated by burning external air. Since the boiler 30 generates steam by burning liquid ammonia or ammonia, no carbon dioxide is generated, thereby satisfying the emission regulations of the International Maritime Organization. In addition to its original function of generating steam, the boiler 30 can also be used as a gas combustion unit (GCU) to incinerate excess liquid ammonia or ammonia.

The exhaust gas generated from the boiler 30 is discharged to the first exhaust pipe 41, and on the first exhaust pipe 41 is a first post-processing device 40 that reduces at least one of nitrous oxide and nitrogen oxide contained in the exhaust gas. ) can be installed. The first post-treatment device 40 reduces at least one of nitrous oxide and nitrogen oxide using liquid ammonia or ammonia as a reducing agent, and the specific structure will be described in more detail later. The first post-processing device 40 may have first reducing agent supply pipes 50a and 50b connected to one side. The first reducing agent supply pipes (50a, 50b) connect the fuel tank 20 and the first after-treatment device 40 to supply liquid ammonia or ammonia inside the fuel tank 20 as a reducing agent to the first after-treatment device 40. can be supplied. Hereinafter, the structure in which the first reducing agent supply pipes 50a and 50b supply ammonia to the first post-treatment device 40 will be described in more detail. As described above, if the fuel tank 20 is formed as an atmospheric pressure tank, there is an advantage in reducing tank design cost and weight, but the internal pressure is not high, so liquid ammonia can easily vaporize naturally. Alternatively, liquid ammonia may naturally vaporize due to sloshing or the like. Ammonia generated by vaporization of liquid ammonia causes various problems such as increasing the pressure inside the tank and promoting vaporization of liquid ammonia, so it is discharged through the first reducing agent supply pipes (50a, 50b) and used in the first post-treatment device (40). can be supplied. An exhaust gas circulation pipe 42 is branched from the first exhaust pipe 41 at the front or rear end of the first post-processing device 40, and the exhaust gas circulation pipe 42 stores at least some of the exhaust gas generated from the boiler 30. can be circulated through the air supply pipe (43). The exhaust gas circulated through the air supply pipe 43 lowers the temperature of the combustion chamber of the boiler 30, and thus the generation of nitrogen oxides can be suppressed.

Additionally, the first post-treatment device 40 may receive urea water as a reducing agent. That is, the first post-treatment device 40 can receive liquid ammonia or ammonia as a reducing agent through the first reducing agent supply pipes (50a, 50b), or receive urea water as a reducing agent through the urea water supply pipes (81a, 81b). there is. The urea water supply pipes (81a, 81b) connect the urea water tank 80 and the first post-treatment device 40 and supply the urea water stored inside the urea water tank 80 to the first post-treatment device 40. , when it is difficult to supply liquid ammonia or ammonia through the first reducing agent supply pipes (50a, 50b), they can be selectively opened to supply urea water. The urea water supply pipes (81a, 81b) selectively supply urea water only when it is difficult to supply liquid ammonia or ammonia through the first reducing agent supply pipes (50a, 50b), so only a small amount of urea water needs to be provided, so the urea water tank (80) ) can be reduced in size, and the energy consumed in operating the temperature control system to prevent deterioration of urea water can also be reduced.

The engine 60 receives liquid ammonia or ammonia from the second fuel supply pipe 61 connected to the fuel tank 20 and burns it to generate power. For example, it may be an ammonia engine. Hereinafter, the structure in which the engine 60 receives liquid ammonia and burns it to generate steam will be described in more detail. One end of the second fuel supply pipe 61 penetrates the fuel tank 20 and is connected to the low-pressure pump 21, and the other end extends outside the fuel tank 20 to be connected to the engine 60. In the drawing, the second fuel supply pipe 61 is shown as branched from the first fuel supply pipe 31, but it is not limited to this, and one end of the second fuel supply pipe 61 may be directly connected to the low pressure pump 21. there is. A pre-treatment device 62 for pre-processing liquid ammonia or ammonia is installed on the second fuel supply pipe 61, and the pre-treatment device 62 includes at least one boosting pump for pressurizing liquid ammonia or ammonia, and compressing liquid ammonia or ammonia into seawater. It may include at least one heater that heats by exchanging heat with at least one of , fresh water, and glycol water. In the drawing, the heater is shown as installed at the rear of the booster pump, but it is not limited to this, and the arrangement of the booster pump and heater can be modified in various ways. Liquid ammonia or ammonia pressurized and heated in the pretreatment device 62 is supplied to the engine 60 through the second fuel supply pipe 61, and the engine 60 generates power by burning the liquid ammonia or ammonia. Since the engine 60 generates power by burning liquid ammonia or ammonia, no carbon dioxide is generated, thereby satisfying the International Maritime Organization's emission regulations.

The exhaust gas generated from the engine 60 is discharged through the second exhaust pipe 91, and on the second exhaust pipe 91, there is a second post-processing device 90 that reduces at least one of nitrous oxide and nitrogen oxide contained in the exhaust gas. ) can be installed. The second post-treatment device 90 reduces at least one of nitrous oxide and nitrogen oxide using liquid ammonia or ammonia as a reducing agent, and the specific structure will be described in more detail later. The second post-processing device 90 may have second reducing agent supply pipes 100a and 100b connected to one side. The second reducing agent supply pipes (100a, 100b) connect the fuel tank 20 and the second after-treatment device 90 to supply liquid ammonia or ammonia inside the fuel tank 20 as a reducing agent to the second after-treatment device 90. can be supplied. In the drawing, the second reducing agent supply pipes (100a, 100b) are shown as branched from the first reducing agent supply pipes (50a, 50b), but this is not limited to this, and the second reducing agent supply pipes (100a, 100b) are connected to the fuel tank (20). It can also be directly connected to . Hereinafter, the structure in which the second reducing agent supply pipes 100a and 100b supply ammonia to the second post-treatment device 90 will be described in more detail.

The first post-processing device 40 and the second post-processing device 90 may include a selective catalytic reduction reactor (40a, 90a) for nitrous oxide and a selective catalytic reduction reactor (40b, 90b) for nitrogen oxide, respectively. there is.

The selective catalytic reduction reactor (40a, 90a) for nitrous oxide is a catalytic reactor that reduces nitrous oxide contained in exhaust gas to nitrogen and oxygen using liquid ammonia or ammonia as a reducing agent. Liquid ammonia or exhaust gas mixed with ammonia is fed into the reactor. Nitrous oxide can be reduced to nitrogen and oxygen by passing it through an installed catalytic filter. As shown in FIG. 2, the catalyst filter may be formed in a honeycomb structure or a plate structure, and at least one may be installed inside the reactor. More specifically, the catalyst filter is a catalyst in which at least one of cobalt (Co), rhodium ( _Rh ), and cerium-cobalt composite oxide (Ce-Co-O) is supported on a carrier made of aluminum oxide (Al ₂ O 3 ), Alternatively, it may include a catalyst in which rhodium (Rh) is supported on a carrier made of aluminum oxide (Zn-Al ₂ O ₃ ) impregnated with zinc, or a catalyst in which iron (Fe) is supported on a carrier made of zeolite. . The selective catalytic reduction reactor (40a) for nitrous oxide of the first post-treatment device (40) is connected to a first reducing agent supply pipe (50a) and a urea water supply pipe (81a) on one side, and the second post-treatment device (90) The selective catalytic reduction reactor for nitrous oxide (90a) may be connected to a second reducing agent supply pipe (100a) and a urea water supply pipe (81b) on one side. Selective catalytic reduction reactors (40b, 90b) for nitrogen oxide may be installed at the rear of the selective catalytic reduction reactors (40a, 90a) for nitrous oxide.

The selective catalytic reduction reactor (40b, 90b) for nitrogen oxides is a catalytic reactor that reduces nitrogen oxides contained in exhaust gas to nitrogen and water using liquid ammonia or ammonia as a reducing agent. Nitrogen oxides can be reduced to nitrogen and water by passing them through a catalytic filter. Since the reduction reaction temperature of nitrogen oxides is lower than the reduction reaction temperature of nitrous oxide, the selective catalytic reduction reactors (40b, 90b) for nitrogen oxides can be installed at the rear of the selective catalytic reduction reactors (40a, 90a) for nitrous oxide. The catalyst filter may be formed in a honeycomb structure or a plate structure, and at least one may be installed inside the reactor. Since the selective catalytic reduction reactors (40b, 90b) for nitrogen oxides that reduce nitrogen oxides are known technologies, a detailed description of the catalyst filter will be omitted. The selective catalytic reduction reactor (40b) for nitrogen oxides of the first post-processing device (40) is connected to a first reducing agent supply pipe (50b) on one side, and the selective catalytic reduction reactor (40b) for nitrogen oxides of the second post-processing device (90) (90b) may be connected to a second reducing agent supply pipe (100b) on one side.

Meanwhile, when the operation of the first post-treatment device 40 is stopped, the liquid ammonia or ammonia remaining in the first reducing agent supply pipes 50a and 50b must be quickly treated. The recovery pipe 70 can recover the liquid ammonia or ammonia remaining inside the first reducing agent supply pipes 50a and 50b and supply it to the engine 60 or boiler 30. Liquid ammonia or ammonia recovered through the recovery pipe 70 is first supplied as fuel to the running engine 60, and when the engine 60 is not running, it can be supplied as fuel to the boiler 30. The recovery pipe 70 is connected to the first recovery pipe 71 connected to the first fuel supply pipe 31 in front of the pretreatment device 32 and the second fuel supply pipe 61 in front of the pretreatment device 62. Including the second recovery pipe 72, liquid ammonia or ammonia can be supplied to the first fuel supply pipe 31 and the second fuel supply pipe 61, respectively. In addition, the liquid ammonia or ammonia recovered through the recovery pipe 70 may be supplied as a reducing agent to the second post-treatment device 90 through the branch pipe 73 branched from the recovery pipe 70. The branch pipe 73 is connected to the second reducing agent supply pipes 100a and 100b and can supply the recovered liquid ammonia or ammonia to the second reducing agent supply pipes 100a and 100b. Additionally, the liquid ammonia or ammonia recovered through the recovery pipe 70 may be supplied to the exhaust gas circulation pipe 42 through the return pipe 74 branched from the recovery pipe 70.

On the other hand, when the driving of the engine 60 is stopped and the second after-treatment device 90 installed in the second exhaust pipe 91 is not driven and the boiler 30 is not driven, the water recovered into the recovery pipe 70 Liquid ammonia or ammonia may be supplied to the boiler 30 through the first recovery pipe 71 or the return pipe 74 and incinerated. That is, the boiler 30 can be used as a gas incineration device to incinerate liquid ammonia or ammonia. The exhaust gas resulting from the incineration of liquid ammonia or ammonia in the boiler 30 is supplied to the first post-treatment device 40 through the first exhaust pipe 41, and at this time, urea is supplied through the urea water supply pipes 81a and 81b. Urea water is supplied from the water tank 80, so that nitrous oxide and nitrogen oxides contained in the exhaust gas can be removed. In this way, the liquid ammonia or ammonia remaining in the first reducing agent supply pipes 50a and 50b is recovered and used as fuel for the running engine 60 or boiler 30, or as a reducing agent for the second post-treatment device 90. Alternatively, by incinerating it in the boiler 30, ammonia can be effectively treated without a separate ammonia vent system and space utilization within the ship can be increased.

Hereinafter, with reference to FIGS. 3 to 5, the operation of the ammonia fuel vessel 1 will be described in more detail.

Figures 3 to 5 are operational diagrams for explaining the operation of an ammonia fuel ship.

FIG. 3 is an operation diagram for explaining the operation when the first post-processing device is normally operated, and FIGS. 4 and 5 are operation diagrams for explaining the operation when the first post-processing device is not normally operated.

First, referring to FIG. 3, the liquid ammonia stored in the fuel tank 20 is pressurized by the low pressure pump 21 and flows into the first fuel supply pipe 31 and the second fuel supply pipe 61, respectively, and the fuel tank ( Ammonia generated by vaporizing the liquid ammonia stored in 20) flows into the first reducing agent supply pipes (50a, 50b) and the second reducing agent supply pipes (100a, 100b), respectively.

The liquid ammonia flowing into the first fuel supply pipe 31 is heated in the pretreatment device 32 and then supplied to the boiler 30, and the boiler 30 combines the air supplied through the air supply pipe 43 with the first fuel supply pipe. Steam is generated by burning the liquid ammonia supplied through (31). The exhaust gas resulting from the combustion of liquid ammonia in the boiler 30 is discharged through the first exhaust pipe 41 and supplied to the selective catalytic reduction reactor for nitrous oxide (40a), and the selective catalytic reduction reactor for nitrous oxide (40a) is the first exhaust gas. Ammonia supplied through the reducing agent supply pipe 50a is used as a reducing agent to reduce nitrous oxide into nitrogen and oxygen. The exhaust gas from which nitrous oxide has been removed is supplied to the selective catalytic reduction reactor for nitrogen oxides (40b), and the selective catalytic reduction reactor for nitrogen oxides (40b) uses ammonia supplied through the second reducing agent supply pipe (50b) as a reducing agent to produce nitrogen. Reduces oxides to nitrogen and water. The exhaust gas from which nitrogen oxides have been removed is discharged into the atmosphere through the first exhaust pipe 41.

The liquid ammonia flowing into the second fuel supply pipe 61 is pressurized and heated in the pretreatment device 62 and then supplied to the engine 60, and the engine 60 generates power by burning the liquid ammonia. The exhaust gas resulting from the combustion of liquid ammonia in the engine 60 is discharged through the second exhaust pipe 91 and supplied to the selective catalytic reduction reactor for nitrous oxide (90a), and the selective catalytic reduction reactor for nitrous oxide (90a) is the first. Ammonia supplied through the reducing agent supply pipe 100a is used as a reducing agent to reduce nitrous oxide into nitrogen and oxygen. The exhaust gas from which nitrous oxide has been removed is supplied to the selective catalytic reduction reactor for nitrogen oxides (90b), and the selective catalytic reduction reactor for nitrogen oxides (90b) uses ammonia supplied through the second reducing agent supply pipe (100b) as a reducing agent to produce nitrogen. Reduces oxides to nitrogen and water. The exhaust gas from which nitrogen oxides have been removed is discharged into the atmosphere through the second exhaust pipe 91.

Next, referring to FIG. 4, when the operation of the first after-treatment device 40 and the boiler 30 is stopped and the engine 60 and the second after-treatment device 90 are normally operated, the first reducing agent supply pipe The liquid ammonia or ammonia remaining in (50a, 50b) is recovered into the recovery pipe (70) and then supplied to the second fuel supply pipe (61) in front of the pretreatment device (62) through the second recovery pipe (72) to the engine ( 60), or it can be supplied to the second reducing agent supply pipes 100a and 100b through the branch pipe 73 and used as a reducing agent in the second post-treatment device 90. When liquid ammonia or ammonia is supplied to the second fuel supply pipe (61) and the second reducing agent supply pipe (100a, 100b) through the second recovery pipe (72) and the branch pipe (73), respectively, the second fuel supply pipe (61) And the second reducing agent supply pipes 100a and 100b may stop supplying liquid ammonia or ammonia from the fuel tank 20.

Next, referring to FIG. 5, when the operation of the first post-processing device 40, the engine 60, and the second post-processing device 90 is all stopped, the remaining in the first reducing agent supply pipes 50a and 50b Liquid ammonia or ammonia is recovered into the recovery pipe 70 and then supplied to the first fuel supply pipe 31 in front of the pretreatment device 32 through the first recovery pipe 71 to be used as fuel for the boiler 30. . At this time, the first fuel supply pipe 31 may stop supplying liquid ammonia or ammonia from the fuel tank 20. Meanwhile, when the operation of the boiler 30 is stopped, the liquid ammonia or ammonia recovered through the recovery pipe 70 is discharged to the first fuel supply pipe 31 or exhaust gas through the first recovery pipe 71 or the return pipe 74. It can be supplied to the circulation pipe 42 and incinerated in the boiler 30. When the boiler 30 burns liquid ammonia or ammonia, exhaust gas containing nitrous oxide and nitrogen oxide is discharged, so the urea water inside the urea water tank 80 through the urea water supply pipes 81a and 81b is first and then It can be supplied to the processing device 40. The first post-treatment device 40 can reduce nitrous oxide and nitrogen oxides contained in the exhaust gas using urea water as a reducing agent.

Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention can be implemented in other specific forms without changing its technical idea or essential features. You will be able to understand it. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive.

1: Ammonia fueled ships
10: Hull 20: Fuel tank
21: low pressure pump 30: boiler
31: first fuel supply pipe 32: pretreatment device
40: First post-processing device
40a: Selective catalytic reduction reactor for nitrous oxide
40b: Selective catalytic reduction reactor for nitrogen oxides
41: first exhaust pipe 42: exhaust gas circulation pipe
43: air supply pipe 50a, 50b: first reducing agent supply pipe
60: Engine 61: Second fuel supply pipe
62: pretreatment device 70: recovery pipe
71: first recovery pipe 72: second recovery pipe
73: branch pipe 74: water return pipe
80: Urea tank 81a, 81b: Urea water supply pipe
90: Second post-processing device
90a: Selective catalytic reduction reactor for nitrous oxide
90b: Selective catalytic reduction reactor for nitrogen oxides
91: second exhaust pipe 100a, 100b: second reducing agent supply pipe

Claims (8)

hull;
A fuel tank installed on the hull and storing liquid ammonia;
A boiler that receives the liquid ammonia or ammonia generated by vaporizing the liquid ammonia from a first fuel supply pipe connected to the fuel tank and combusts it to generate steam;
a first post-treatment device installed on a first exhaust pipe connected to the boiler to reduce at least one of nitrous oxide and nitrogen oxide contained in exhaust gas generated from the boiler;
a first reducing agent supply pipe connecting the fuel tank and the first after-treatment device to supply the liquid ammonia or the ammonia inside the fuel tank as a reducing agent to the first after-treatment device;
An engine that receives the liquid ammonia or the ammonia from a second fuel supply pipe connected to the fuel tank and combusts it, and
An ammonia fuel ship comprising a recovery pipe for recovering the liquid ammonia or ammonia remaining inside the first reducing agent supply pipe and supplying it to the engine or the boiler. According to claim 1,
A urea water tank that stores the urea water inside, and
It further includes a urea water supply pipe that connects the urea water tank and the first post-treatment device to supply the urea water to the first post-treatment device,
The first post-treatment device is an ammonia fuel vessel that receives the liquid ammonia or the ammonia as a reducing agent through the first reducing agent supply pipe or supplies the urea water as a reducing agent through the urea water supply pipe. According to claim 1,
The first fuel supply pipe and the second fuel supply pipe each further include a pretreatment device for preprocessing the liquid ammonia or the ammonia,
The recovery pipe is,
An ammonia fuel vessel comprising a first recovery pipe connected to the first fuel supply pipe in front of the pretreatment device, and a second recovery pipe connected to the second fuel supply pipe in front of the pretreatment device. According to claim 1,
A second after-treatment device installed on a second exhaust pipe connected to the engine to reduce at least one of nitrous oxide and nitrogen oxide contained in the exhaust gas generated by the engine, and
An ammonia fuel vessel further comprising a branch pipe branched from the recovery pipe to supply the liquid ammonia or the ammonia as a reducing agent to the second post-treatment device. According to clause 4,
It further includes a second reducing agent supply pipe that connects the fuel tank and the second post-treatment device to supply the liquid ammonia or the ammonia inside the fuel tank as a reducing agent to the second after-treatment device,
The branch pipe is an ammonia fuel ship that supplies the liquid ammonia or the ammonia to the second reducing agent supply pipe. The method of claim 4, wherein the first post-processing device and the second post-processing device each have,
An ammonia fuel ship comprising a selective catalytic reduction reactor for nitrous oxide that removes the nitrous oxide, and a selective catalytic reduction reactor for nitrogen oxides installed at a rear end of the selective catalytic reduction reactor for nitrous oxide to remove the nitrogen oxides. The method of claim 6, wherein the selective catalytic reduction reactor for nitrous oxide,
A catalyst containing at least one of cobalt (Co), rhodium (Rh), and cerium-cobalt composite oxide (Ce-Co-O) supported on a carrier made of aluminum oxide (Al ₂ O ₃ ), or aluminum oxide impregnated with zinc ( Including a catalyst in which rhodium (Rh) is supported on a carrier made of Zn-Al ₂ O ₃ ), or a catalyst in which iron (Fe) is supported on a carrier made of zeolite, the liquid ammonia or the ammonia is used as a reducing agent. An ammonia-fueled vessel in which, when supplied, the nitrous oxide is reduced to nitrogen and oxygen. According to claim 1,
An exhaust gas circulation pipe branched from the first exhaust pipe and circulating exhaust gas generated in the boiler to the air supply pipe of the boiler, and
Ammonia fuel vessel further comprising a water return pipe branched from the return pipe to supply the liquid ammonia or the ammonia to the exhaust gas circulation pipe.

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