KR20240018883A - 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, a combustion engine that receives liquid ammonia from the fuel tank through a fuel supply pipe and burns it to generate power; , a discharge line that opens in the event of a trip or abnormality of the combustion engine and discharges liquid ammonia remaining in the combustion engine or ammonia produced by vaporizing liquid ammonia, and a knock installed on the discharge line to separate liquid ammonia from ammonia. A fuel supply line that connects the out drum, an oil tanker or a fuel tank terminal, and the fuel tank to supply liquid ammonia to the fuel tank, a first purge line that injects the first purge gas into the fuel tank, and oil supply at the rear end of the first purge line. It may include a branch line that branches off from the line and supplies the liquid ammonia and first purge gas remaining in the fuel supply line to the knockout drum.

Description

Ammonia fuel vessel

The present invention relates to an ammonia-fueled ship, and more specifically, to an ammonia-fueled ship capable of easily processing liquid ammonia and purge gas in a fuel supply pipe.

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. It is one of the next-generation eco-friendly fuels, which does not emit carbon dioxide when burned and has a low liquefaction point. Ammonia, which is high and easy to store, is emerging.

Liquid ammonia stored in a fuel tanker or oil terminal is supplied to the fuel tank through a fuel tank line. When a certain amount of liquid ammonia is stored in the fuel tank, the fuel tank line must be separated and the liquid ammonia remaining in the tank tank must be disposed of. Conventionally, liquid ammonia was purged into the fuel tank by injecting a purge gas such as nitrogen into the fuel supply line. As a result, there was a problem that nitrogen was injected into the fuel tank together with liquid ammonia. Not only is nitrogen not used as fuel, but it also increases the pressure inside the tank, so it must be discharged from the fuel tank. Accordingly, nitrogen mixed with ammonia was supplied to the reliquefaction device to control the pressure inside the tank. However, since the reliquefaction device is designed based on the liquefaction temperature of ammonia, nitrogen with a lower liquefaction temperature is not reliquefied and is converted into nitrogen. As a result, there is a problem that reliquefaction efficiency is reduced.

Republic of Korea Patent Publication No. 10-2022-0034270 (2022. 03. 18.)

The technical problem to be achieved by the present invention is to provide an ammonia fuel vessel that can easily process liquid ammonia and purge gas in the fuel supply pipe.

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 receiving liquid ammonia from the fuel tank through a fuel supply pipe. A combustion engine that burns to generate power, a discharge line that opens when the combustion engine trips or malfunctions and discharges the liquid ammonia remaining in the combustion engine or ammonia generated by vaporizing the liquid ammonia, and A knockout drum installed on the discharge line to separate the liquid ammonia from the ammonia, a fuel supply line connected between a fuel tanker or oil supply terminal and the fuel tank to supply the liquid ammonia to the fuel tank, and a fuel supply line connected to the fuel tank. It includes a first purge line that injects the first purge gas, and a branch line that branches off from the oil supply line at the rear end of the first purge line and supplies the liquid ammonia remaining in the fuel supply line and the first purge gas to the knockout drum. do.

The ammonia fuel vessel includes a fuel processing unit installed on the fuel supply pipe to heat and pressurize the liquid ammonia, and a second purge gas that is injected into the fuel supply pipe at the rear end of the fuel processing unit to remain in the fuel supply pipe and the combustion engine. It may further include a second purge line for purging the liquid ammonia, the ammonia, and the second purge gas to the discharge line,

The ammonia fuel vessel further includes a fuel circulation pipe that circulates unburned liquid ammonia inside the combustion engine to the fuel supply pipe, and the discharge line may branch from the fuel circulation pipe.

The ammonia fuel vessel includes a cooler installed on the fuel circulation pipe at a rear end of the discharge line to cool the unburned liquid ammonia, and a cooler installed on the fuel circulation pipe at a rear end of the cooler to depressurize the unburned liquid ammonia. It may further include a pressure reducing valve.

The ammonia fuel vessel has a first discharge line connected to the top of the knockout drum to discharge the first purge gas or the second purge gas and the ammonia, and a first discharge line connected to the bottom of the knockout drum to discharge the liquid ammonia. It may further include a second discharge line supplying to the fuel tank.

The ammonia fuel vessel may further include a buffer tank installed on the second discharge line to temporarily store the liquid ammonia discharged from the knockout drum.

According to the present invention, the liquid ammonia and the first purge gas remaining in the fuel supply line are supplied to the liquid ammonia remaining in the combustion engine or a knockout drum installed on the discharge line for discharging ammonia to produce liquid ammonia and the first purge gas. By separating, it is possible to prevent an increase in the internal pressure of the fuel tank due to the first purge gas, thereby minimizing the vaporization of liquid ammonia stored in the fuel tank, and also to increase the purity of the fuel, thereby increasing the fuel efficiency of the combustion engine. In particular, since only the ammonia in the fuel tank is supplied to the re-liquefaction device and re-liquefied, the tank pressure can be controlled more easily and re-liquefaction efficiency can be increased.

In addition, the liquid ammonia separated from the knockout drum is supplied to the fuel tank and used as fuel, so the ship can be operated more economically.

1 is a diagram showing an ammonia-fueled ship according to the present invention.
Figures 2 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 the present invention supplies the liquid ammonia and the first purge gas remaining in the fueling line to a knockout drum installed on the discharge line that discharges the liquid ammonia or ammonia remaining in the combustion engine, thereby producing liquid ammonia and the first purge gas. By separating the purge gas, it is possible to minimize the vaporization of liquid ammonia stored in the fuel tank by preventing an increase in internal pressure of the fuel tank due to the first purge gas, as well as increase the purity of the fuel, thereby improving the fuel efficiency of the combustion engine. there is. In particular, since only the ammonia in the fuel tank is supplied to the re-liquefaction device and re-liquefied, the tank pressure can be controlled more easily and re-liquefaction efficiency can be increased. In addition, the liquid ammonia separated from the knockout drum is supplied to the fuel tank and used as fuel, allowing the ship to be operated more economically.

Hereinafter, with reference to FIG. 1, the ammonia fuel ship 1 will be described in detail.

1 is a diagram showing an ammonia-fueled ship according to the present invention.

The ammonia fuel ship (1) according to the present invention includes a hull (10), a fuel tank (20), a combustion engine (30), a discharge line (40), a knockout drum (50), a refueling line (60), and a first purge. It includes a line 70 and a branch line 80.

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 from a combustion engine 30, 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. For example, the fuel tank 20 may be formed as a membrane-type normal pressure tank in which the internal pressure is maintained constant. However, the fuel tank 20 is not limited to being formed as a membrane type normal pressure tank, and the type of fuel tank 20 may be modified in various ways.

Liquid ammonia stored in the fuel tank 20 is supplied to the combustion engine 30 through the fuel supply pipe 31, and the combustion engine 30 burns the supplied liquid ammonia to generate power necessary for propulsion of the hull 10. can do. Since the fuel processing unit 90 that heats and pressurizes liquid ammonia is installed on the fuel supply pipe 31, the liquid ammonia stored in the fuel tank 20 is heated and pressurized to the temperature and pressure required by the combustion engine 30 before being supplied. It can be. The fuel processing unit 90 includes, for example, a first heater 91 that heats liquid ammonia, a booster pump 92 that pressurizes the liquid ammonia heated in the first heater 91, and a booster pump 92. It may include a second heater 93 that heats the pressurized liquid ammonia. However, the fuel processing unit 90 is not limited to including the first heater 91, the booster pump 92, and the second heater 93, and the configuration and arrangement of the fuel processing unit 90 may be modified in various ways. You can.

The liquid ammonia supplied to the combustion engine 30 is burned at only about 80 to 90% of the total amount supplied, and about 10 to 20% of the unburned liquid ammonia inside the combustion engine 30 is transferred to the fuel through the fuel circulation pipe 110. It can be circulated to the supply pipe (31). Since a cooler 111 to cool the unburned liquid ammonia and a pressure reducing valve 112 disposed at the rear of the cooler 111 to reduce the pressure of the unburned liquid ammonia are installed on the fuel circulation pipe 110, the unburned liquid ammonia is stored appropriately. After being cooled and decompressed by temperature and pressure, it can join the liquid ammonia flowing through the fuel supply pipe 31. In the drawing, the fuel circulation pipe 110 is shown as connected to the fuel supply pipe 31 between the first heater 91 and the booster pump 92, but the connection point of the fuel circulation pipe 110 is not limited to this. It can be modified as needed.

Meanwhile, in the event of an abnormality such as a trip or shutdown of the combustion engine 30, the liquid ammonia remaining in the combustion engine 30 must be quickly discharged. Liquid ammonia remaining in the combustion engine 30 or ammonia generated by vaporization of liquid ammonia is discharged through the discharge line 40, and the discharge line 40 branches off from the fuel circulation pipe 110 in front of the cooler 111. It can be. That is, liquid ammonia or liquid ammonia remaining in the combustion engine 30 may be discharged to the discharge line 40 through the fuel circulation pipe 110. Since a control valve (not shown) whose opening and closing is controlled in connection with the combustion engine 30 is installed on the discharge line 40, the flow of liquid ammonia or ammonia can be controlled. More specifically, the liquid ammonia or ammonia remaining in the combustion engine 30 is discharged to the discharge line 40 by a second purge gas, for example, an inert gas such as nitrogen, and the second purge gas is the second purge gas. It can be supplied through line 100. The second purge line 100 injects the second purge gas into the fuel supply pipe 31 at the rear end of the fuel processing unit 90 to purge the liquid ammonia or ammonia remaining in the fuel supply pipe 31 and the combustion engine 30 and the second purge. Gas can be purged into the discharge line 40. Liquid ammonia or ammonia purged through the discharge line 40 and the second purge gas are supplied to the knockout drum 50 installed on the discharge line 40.

The knockout drum 50 separates the liquid ammonia discharged from the combustion engine 30, ammonia, and the second purge gas, and can be formed as a typical gravity separator. Ammonia and the second purge gas separated from the knockout drum 50 are discharged to the first discharge line 51 connected to the top of the knockout drum 50 and are released into the atmosphere or used as fuel for a boiler (not shown). , the liquid ammonia separated from the knockout drum 50 may be discharged to the second discharge line 52 connected to the bottom of the knockout drum 50 and supplied to the fuel tank 20. The second discharge line 52 is connected to the refueling line 60 and supplies liquid ammonia to the fuel tank 20 through the refueling line 60, and is supplied to the knockout drum 50 on the second discharge line 52. A buffer tank 53 is installed to temporarily store discharged liquid ammonia, so that liquid ammonia can be supplied to the oil supply line 60 at a constant pressure. The recovery pipe 54 branched from the fuel circulation pipe 110 at the rear end of the pressure reducing valve 112 is connected to the buffer tank 53 and can supply cooled and reduced pressure liquid ammonia to the buffer tank 53. A control valve (not shown) is installed on the recovery pipe 54 to control the flow of liquid ammonia. However, the second discharge line 52 is connected to the oil supply line 60, and the buffer tank 53 is installed on the second discharge line 52. If necessary, the second discharge line 60 (52) may be directly connected to the fuel tank 20, and the buffer tank 53 and return pipe 54 may be omitted.

The above-mentioned fuel tank 20 can be refueled with liquid ammonia through the oil supply line 60. One end of the refueling line 60 is detachably coupled to a supply line (not shown) installed on a refueling ship (not shown) or a refueling terminal (not shown), and the other end may be fixed to the fuel tank 20. A control valve (not shown) is installed on the oil supply line 60 to control the flow of liquid ammonia. When liquid ammonia is supplied through the refueling line 60, the supply conditions of the refueling ship or refueling terminal do not perfectly match the supply conditions of the fuel tank 20, so the liquid ammonia refueled in the fuel tank 20 is vaporized and a large amount of it is vaporized. Ammonia may be generated. Ammonia increases the pressure inside the tank and promotes vaporization of liquid ammonia, so it can be discharged through the exhaust line 120.

The exhaust line 120 is a line that opens when liquid ammonia is refueled into the fuel tank 20 and exhausts the ammonia inside the fuel tank 20 to the oil tanker or fuel tank terminal. One end is fixed to the top of the fuel tank 20. The other end may be detachably coupled to the supply line. When liquid ammonia is supplied to the fuel tank 20, the exhaust line 120 is opened to exhaust the ammonia, thereby controlling the internal pressure of the fuel tank 20 and suppressing evaporation of the liquid ammonia. A control valve (not shown) is installed on the exhaust line 120 to control the flow of ammonia. A reliquefaction line 130 may be branched from the exhaust line 120 at the rear of the control valve.

The reliquefaction line 130 is a line that reliquefies the ammonia inside the fuel tank 20 and supplies it to the fuel supply line 60. On the reliquefaction line 130, there is a compressor (not shown) and a cooler (not shown). A reliquefaction device 130 including an expansion valve (not shown), an expansion valve (not shown), or a pressure reducing device (not shown) may be installed. A control valve (not shown) is installed on the reliquefaction line 130 at the front of the reliquefaction device 130 to control the flow of ammonia, and if necessary, the reliquefaction line at the rear of the reliquefaction device 130. A gas-liquid separator (not shown) may be installed on (130).

A first purge line 70 may be connected to the oil supply line 60. The first purge line 70 is a line that purges the liquid ammonia remaining in the fuel supply line 60 by injecting a first purge gas, for example, an inert gas such as nitrogen, into the fuel tank (60). It can be opened after refueling of liquid ammonia is completed in 20). That is, the control valve installed in the oil supply line 60 and the control valve (not shown) installed in the first purge line 70 to control the flow of the first purge gas can be selectively opened. A branch line 80 may be branched from the oil supply line 60 at the rear end of the first purge line 70.

The branch line 80 is a line that supplies liquid ammonia and the first purge gas remaining in the oil supply line 60 to the knockout drum 50, and can be opened together with the first purge line 70. That is, the control valve installed in the first purge line 70 and the control valve (not shown) installed in the branch line 80 may be opened simultaneously. The liquid ammonia remaining in the fuel supply line 60 and the first purge gas are supplied to the knockout drum 50 through the branch line 80 and separated, thereby preventing an increase in internal pressure of the fuel tank 20 due to the first purge gas. By preventing this, the vaporization of liquid ammonia stored in the fuel tank 20 can be minimized, and the fuel efficiency of the combustion engine 30 can be improved by increasing the purity of the fuel. In addition, the first purge gas and ammonia are not supplied to the reliquefaction device 130 together as in the past, but only the ammonia in the fuel tank 20 is supplied to the reliquefaction device 130, making it easier to control the pressure inside the tank. This can be achieved and the reliquefaction efficiency can be increased. The first purge gas and ammonia separated from the knockout drum 50 are discharged to the first discharge line 51 and released into the atmosphere or used as fuel for a boiler, and the liquid ammonia separated from the knockout drum 50 is discharged into the first discharge line 51. 2 It can be discharged through the discharge line 52 and supplied to the fuel tank 20 after passing through the buffer tank 53.

Hereinafter, with reference to FIGS. 2 to 5, the operation of the ammonia fuel vessel 1 will be described in more detail.

Figures 2 to 5 are operational diagrams for explaining the operation of an ammonia fuel ship.

The ammonia fuel ship (1) according to the present invention supplies the liquid ammonia and the first purge gas remaining in the refueling line (60) to the knockout drum (50) installed on the discharge line (40) to produce liquid ammonia and the first purge gas. By separating the purge gas, it is possible to prevent an increase in the internal pressure of the fuel tank 20 due to the first purge gas, thereby minimizing the vaporization of liquid ammonia stored in the fuel tank 20, and also to increase the purity of the fuel, thereby increasing the combustion engine (30) Fuel efficiency can also be improved. In particular, since only the ammonia in the fuel tank 20 is supplied to the re-liquefaction device 130 and re-liquefied, the tank internal pressure can be adjusted more easily and re-liquefaction efficiency can be increased. In addition, since the liquid ammonia separated from the knockout drum 50 is supplied to the fuel tank 20 and used as fuel, the ship can be operated more economically.

FIG. 2 is an operation diagram for explaining the operation of refueling liquid ammonia into the fuel tank, and FIG. 3 is an operation diagram for explaining the operation of purging with the first purge gas after the refueling of liquid ammonia is completed. Figure 4 is an operation diagram to explain the operation of supplying liquid ammonia to the combustion engine, and Figure 5 is an operation diagram to explain the operation of purging with the second purge gas when the combustion engine trips or malfunctions.

When the oil supply line 60 is connected to a supply line installed in a fuel tanker or oil supply terminal, liquid ammonia is supplied from the oil tanker or oil tank terminal to the fuel tank 20, as shown in FIG. Simultaneously or sequentially, the exhaust line 120 may be opened to exhaust the ammonia inside the fuel tank 20 to a fuel tanker or a fuel tank terminal. When liquid ammonia is supplied to the fuel tank 20, the exhaust line 120 is opened, and the ammonia generated by vaporizing the liquid ammonia in the fuel tank 20 is exhausted, thereby controlling the internal pressure of the fuel tank 20. It can suppress the vaporization of liquid ammonia.

When a certain amount of liquid ammonia is supplied to the fuel tank 20, as shown in FIG. 3, the fuel supply line 60 and the exhaust line 120 connected to the supply line are separated and closed, and the first purge line 70 is closed. ) and branch line (80) are opened. As the first purge line 70 and the branch line 80 are opened, the liquid ammonia remaining in the fuel supply line 60 can be purged to the knockout drum 50 together with the first purge gas. Liquid ammonia and the first purge gas purged through the knockout drum 50 may be separated into gas and liquid and discharged into the second discharge line 52 and the first discharge line 51, respectively. Liquid ammonia discharged to the second discharge line 52 is stored in the buffer tank 53, and ammonia and first purge gas discharged to the first discharge line 51 can be discharged into the atmosphere or used as fuel for a boiler. .

When all the liquid ammonia remaining in the fuel supply line 60 is purged, the first purge line 70 and the branch line 80 are closed, and as shown in FIG. 4, the liquid ammonia stored in the fuel tank 20 is purged. It is supplied to the combustion engine (30). At the same time or sequentially, the ammonia generated by vaporizing the liquid ammonia in the fuel tank 20 moves to the re-liquefaction line 130 through the exhaust line 120 and undergoes a re-liquefaction process in the re-liquefaction device 130. Afterwards, it can be recovered to the fuel tank 20 through the refueling line 60. The liquid ammonia sequentially passes through the first heater 91, the booster pump 92, and the second heater 93 of the fuel processing unit 90 installed on the fuel supply pipe 31, and is heated and pressurized before being transferred to the combustion engine 30. It is supplied to, and the combustion engine 30 generates power by burning liquid ammonia. At this time, the unburned liquid ammonia inside the combustion engine 30 is discharged into the fuel circulation pipe 110, sequentially passes through the cooler 111 and the pressure reducing valve 112, and is cooled and depressurized, and then some of it is discharged into the fuel supply pipe 31. It joins the flowing liquid ammonia, and the remaining part can be recovered to the buffer tank 53 through the recovery pipe 54.

Meanwhile, when the combustion engine 30 trips or malfunctions, as shown in FIG. 5, the discharge line 40 and the second purge line 100 are opened, respectively, to remove the liquid ammonia or ammonia remaining in the combustion engine 30. is discharged to the discharge line (40). Liquid ammonia or ammonia purged to the discharge line 40 through the fuel circulation pipe 110 and the second purge gas are supplied to the knockout drum 50 to separate gas and liquid. Ammonia and second purge gas discharged through the first discharge line 51 are discharged into the atmosphere or used as fuel for a boiler, and liquid ammonia discharged through the second discharge line 52 can be stored in the buffer tank 53. there is. When a certain amount of liquid ammonia is stored in the buffer tank 53, it can be recovered to the fuel tank 20 through the second discharge line 52 and the refueling line 60.

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
30: Combustion engine 31: Fuel supply pipe
40: discharge line 50: knockout drum
51: first discharge line 52: second discharge line
53: buffer tank 54: recovery pipe
60: Oil supply line 70: First purge line
80: branch line 90: fuel processing unit
91: first heater 92: boosting pump
93: second heater 100: second purge line
110: Fuel circulation pipe 111: Cooler
112: pressure reducing valve 120: exhaust line
130: Reliquefaction line 131: Reliquefaction device

Claims (6)

hull;
A fuel tank installed on the hull and storing liquid ammonia;
A combustion engine that receives the liquid ammonia from the fuel tank through a fuel supply pipe and combusts it to generate power;
a discharge line that opens when the combustion engine trips or malfunctions, and discharges the liquid ammonia remaining in the combustion engine or ammonia generated by vaporization of the liquid ammonia;
A knockout drum installed on the discharge line to separate the liquid ammonia and the ammonia;
A fuel supply line connected between a fuel tanker or oil supply terminal and the fuel tank to supply the liquid ammonia to the fuel tank;
A first purge line for injecting a first purge gas into the oil supply line, and
An ammonia fuel ship comprising a branch line that branches off from the fuel supply line at a rear end of the first purge line and supplies liquid ammonia and first purge gas remaining in the fuel supply line to a knockout drum. According to claim 1,
A fuel processing unit installed on the fuel supply pipe to heat and pressurize the liquid ammonia, and
A second purge line is provided to inject a second purge gas into the fuel supply pipe at the rear end of the fuel processing unit to purge the liquid ammonia remaining in the fuel supply pipe and the combustion engine, the ammonia, and the second purge gas to the discharge line. Ammonia-fueled ships containing more. According to clause 2,
It further includes a fuel circulation pipe that circulates unburned liquid ammonia inside the combustion engine to the fuel supply pipe,
An ammonia fuel ship in which the discharge line branches off from the fuel circulation pipe. According to clause 3,
A cooler installed on the fuel circulation pipe at the rear end of the discharge line to cool the unburned liquid ammonia,
An ammonia fuel vessel further comprising a pressure reducing valve installed on the fuel circulation pipe at a rear end of the cooler to reduce the pressure of the unburned liquid ammonia. According to clause 2,
A first discharge line connected to the top of the knockout drum to discharge the first purge gas or the second purge gas and the ammonia,
Ammonia fuel vessel further comprising a second discharge line connected to the bottom of the knockout drum to supply the liquid ammonia to the fuel tank. According to clause 5,
An ammonia fuel vessel further comprising a buffer tank installed on the second discharge line to temporarily store the liquid ammonia discharged from the knockout drum.