Fuel supply system for ships

Abstract

A fuel supply system for ships according to the present invention comprises: a fuel storage tank for storing ammonia fuel; a fuel supply line for supplying the ammonia fuel in the fuel storage tank to an engine; a liquid fuel return line for supplying the ammonia fuel returned from the engine to a vent gas treatment system; and a purging gas supply line connected to the fuel supply line to supply purging gas. The liquid fuel return line is provided with a gas-liquid separation vertical pipe in which liquid ammonia and gaseous ammonia are separated.

Description

Marine fuel supply system

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0096345, filed July 22, 2024, Korean Patent Application No. 10-2024-0198954, filed December 27, 2024, Korean Patent Application No. 10-2025-0000061, filed January 2, 2025, Korean Patent Application No. 10-2025-0028179, filed March 5, 2025, Korean Patent Application No. 10-2025-0050035, filed April 17, 2025, and Korean Patent Application No. 10-2025-0050239, filed April 17, 2025, which are all hereby incorporated by reference. All matters disclosed in the literature are incorporated herein by reference.

[0003] The present invention relates to a fuel supply system for a ship, and more particularly, to a fuel supply system for a ship that omits a catch tank and a purge tank used for ammonia fuel return and venting.

[0004] As regulations on ships become more stringent, the fuel used for ships is shifting from conventional heavy oil to environmentally friendly fuels such as LNG, ammonia, methanol, and hydrogen.

[0005] For example, when ammonia is used as a fuel, due to the toxicity of the fuel, when the fuel supply to the engine is interrupted, the ammonia fuel inside the engine or fuel supply system must be sent to a vent gas treatment system for treatment and then discharged.

[0006] To this end, the purging gas supplied first is transferred to a catch tank along with the ammonia fuel returned from the engine and the ammonia fuel remaining in the fuel supply pipe. In the catch tank, liquid and gaseous ammonia are separated, and the gaseous ammonia is sent to a vent gas treatment system for processing and discharge. Furthermore, the purging gas supplied secondarily is transferred to a purge tank along with the gaseous ammonia remaining in the engine and fuel supply pipe, and the gaseous ammonia is also sent to the vent gas treatment system for processing and discharge.

[0007] Marine fuel supply systems incorporating such ammonia treatment systems have space constraints due to the volume of the separate catch and purge tanks. Furthermore, the operational sequence is complex, as the gaseous ammonia stored in the catch and purge tanks must be re-supplied to the vent gas treatment system.

[0008] The present invention is intended to solve the problems of the prior art discussed above, and to provide a fuel supply system for a ship that can increase space utilization and simplify the operation sequence by omitting a catch tank and a purge tank.

[0009] A fuel supply system for a ship according to one embodiment of the present invention comprises: a fuel storage tank for storing ammonia fuel; a fuel supply line for supplying ammonia fuel from the fuel storage tank to an engine; a liquid fuel return line for supplying ammonia fuel returned from the engine to a vent gas treatment system; and a purging gas supply line connected to the fuel supply line for supplying purging gas, wherein a gas-liquid separation vertical pipe for separating liquid ammonia and gaseous ammonia is provided in the liquid fuel return line.

[0010] In one embodiment, the liquid fuel return line is provided with the gas-liquid separation vertical pipe, a first return pipe between the engine and the gas-liquid separation vertical pipe, and a second return pipe between the gas-liquid separation vertical pipe and the vent gas treatment system, and the gas-liquid separation vertical pipe may have a pipe with a relatively enlarged diameter compared to the first return pipe.

[0011] In one embodiment, at least a portion of the second return pipe may have a first enlarged pipe having a relatively enlarged diameter compared to the first return pipe.

[0012] In one embodiment, the system further comprises a gaseous fuel return line branching from the liquid fuel return line and connected to a vent gas treatment system, through which purging gas and gaseous ammonia are returned, wherein at least a portion of the piping on the gaseous fuel return line may have a second enlarged piping having a relatively enlarged diameter.

[0013] In one embodiment, the extent to which the diameters of the gas-liquid separation vertical pipe and the second expansion pipe are expanded may be determined by at least one of the size of the engine, the size of the fuel supply line, and the size of the liquid fuel return line.

[0014] In one embodiment, the extent to which the diameter of the first expansion pipe is expanded may be determined by at least one of the amount of purging gas and the amount of gaseous ammonia separated in the gas-liquid separation vertical pipe.

[0015] In one embodiment, a return valve train may be provided at a point where the liquid fuel return line and the gaseous fuel return line are connected, and a supply valve train may be provided at the fuel supply line.

[0016] In one embodiment, the method may further include a fuel recovery line for supplying liquid ammonia separated from the gas-liquid separation vertical pipe to the fuel storage tank or engine.

[0017] In one embodiment, the fuel recovery line may be connected to the fuel supply line.

[0018] In one embodiment, the bunker station further comprises a main vapor line connected to the fuel storage tank; a first gaseous fuel return line branching from the liquid fuel return line and connected to the main vapor line; and a second gaseous fuel return line branching from the main vapor line and connected to the vent gas treatment system, wherein the purging gas and gaseous ammonia can be supplied to the vent gas treatment system along the first gaseous fuel return line, the main vapor line, and the second gaseous fuel return line.

[0019] In one example, the system further comprises a main vapor line connected to the fuel storage tank at the bunker station; a BOG line branching from the fuel supply line and connected to the vent gas treatment system; a first gaseous fuel return line branching from the liquid fuel return line and connected to the main vapor line; and a second gaseous fuel return line branching from the main vapor line and connected to the BOG line, wherein the purging gas and gaseous ammonia can be supplied to the vent gas treatment system along the first gaseous fuel return line, the main vapor line, the second gaseous fuel return line, and the BOG line.

[0020] The fuel supply system for a ship of the present invention can improve space utilization and simplify the operation sequence by replacing the catch tank and purge tank with pipes.

[0021] FIG. 1 is a drawing of a fuel supply system for a ship according to a first embodiment of the present invention.

[0022] FIG. 2 is a drawing of a fuel supply system for a ship according to a second embodiment of the present invention.

[0023] Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. When designating components in each drawing, it should be noted that, where possible, identical components are given the same reference numerals, even if they appear in different drawings. Furthermore, when describing embodiments of the present invention, detailed descriptions of known components or functions will be omitted if they are deemed to hinder understanding of the embodiments of the present invention.

[0024] Additionally, terms such as first, second, A, B, (a), (b), etc. may be used to describe components of embodiments of the present invention. These terms are only intended to distinguish the components from other components, and the nature, order, or sequence of the components are not limited by the terms. When it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, but another component may also be "connected," "coupled," or "connected" between each component.

[0025] In this specification, the forward / backward, left / right, and up / down directions are referred to for convenience of explanation and may be orthogonal to each other. However, these directions are determined relatively, and the up / down direction does not necessarily mean the vertical direction.

[0026]

[0027] <Example 1>

[0028] Referring to FIG. 1, a fuel supply system (100) for a ship according to a first embodiment of the present invention includes a fuel storage tank (10) for storing ammonia fuel; a fuel supply line (FSL) for supplying ammonia fuel in the fuel storage tank (10) to an engine (20); a liquid fuel return line (LFRL) for supplying ammonia fuel returned from the engine (20) to a vent gas treatment system (30); and a purging gas supply line (PSL) connected to the fuel supply line (FSL) for supplying purging gas, and a gas-liquid separation vertical pipe (50) for separating liquid ammonia and gaseous ammonia is provided in the liquid fuel return line (LFRL).

[0029] The above vent gas treatment system (30) may be an ammonia treatment system for treating toxic ammonia. For example, the vent gas treatment system (30) may be an ammonia dissolution system that dissolves ammonia, and may be at least one of an absorption tank that dissolves ammonia gas in water, a scrubber that sprays water onto the ammonia gas, or an integrated scrubber in which the absorption tank and the scrubber are combined.

[0030] The type of the vent gas treatment system (30) described above is only an example and is not limited thereto, and the vent gas treatment system (30) may be an ammonia treatment system for reducing the solubility of toxic ammonia.

[0031] A fuel storage tank (10) can store ammonia fuel in a liquid state. Since the fuel storage tank (10) must maintain a predetermined pressure and temperature to store ammonia fuel in a liquid state, it may be an insulated tank capable of blocking heat exchange with the outside.

[0032] A pump (12) may be installed inside the fuel storage tank (10). The pump (12) serves to transfer ammonia fuel to the engine (20). The ammonia fuel in the fuel storage tank (10) may be supplied to the engine (20) through a fuel supply line (FSL). The fuel supply line (FSL) may be defined as a line connecting the fuel storage tank (10) and the engine (20). A heat exchanger (14) and a pump (16) may be provided in the fuel supply line (FSL) to adjust the temperature and pressure of the fuel required for the engine (20). In addition, the pump (12) in the fuel storage tank (10) may be a low-pressure pump, and the pump (16) on the fuel supply line (FSL) may be a high-pressure pump.

[0033] The ammonia fuel that is not completely consumed in the engine (20) and is returned cannot be discharged as is due to its toxicity, but must be recovered and recycled or discharged by passing through a vent gas treatment system (30). To this end, the ammonia fuel returned from the engine (20) can be recovered and recycled or supplied to the vent gas treatment system (30) through a liquid fuel return line (LFRL). The liquid fuel return line (LFRL) can be defined as a line connecting the engine (20) and the vent gas treatment system (30).

[0034] In the event of a fuel supply interruption to the engine (20) or other emergency situations, a purging gas supply unit (40) may be provided to send ammonia fuel inside the engine (20) or the marine fuel supply system (100) to the vent gas treatment system (30). The purging gas may be supplied to the fuel supply line (FSL) and the engine (20) through a purging gas supply line (PSL). The purging gas supply line (PSL) may be defined as a line connecting the purging gas supply unit (40) and the fuel supply line (FSL).

[0035] In the liquid fuel return line (LFRL), a gas-liquid separation vertical pipe (50) is provided to separate liquid ammonia and gaseous ammonia. Purging gas and liquid ammonia can be supplied to the gas-liquid separation vertical pipe (50). The gas-liquid separation vertical pipe (50) is a vertically arranged pipe, and the gas-liquid separation vertical pipe (50) can function as a separator. Therefore, as the ammonia fuel moves along the gas-liquid separation vertical pipe (50), the relatively heavy liquid ammonia falls down due to its weight, and the relatively light gaseous ammonia and purging gas can pass through the gas-liquid separation vertical pipe (50).

[0036] The liquid fuel return line (LFRL) may be provided with a gas-liquid separation vertical pipe (50), a first return pipe (52) between the engine (20) and the gas-liquid separation vertical pipe (50), and a second return pipe (54) between the gas-liquid separation vertical pipe (50) and the vent gas treatment system (30). In this case, the gas-liquid separation vertical pipe (50) may have a pipe with a relatively larger diameter compared to the first return pipe (52).

[0037] Since the gas-liquid separation vertical pipe (50) replaces the role of a conventional catch tank, it can have a relatively enlarged pipe size compared to the existing pipe size to secure the volume of liquid ammonia and purging gas. Therefore, in the present invention, the role of a conventional catch tank can be replaced simply by expanding the pipe, thereby achieving the effects of space savings, cost reduction, and simplified operation sequence.

[0038] In this embodiment, the enlarged pipe of the gas-liquid separation vertical pipe (50) is described in terms of its relative size compared to the first return pipe (52), but it is not limited to the first return pipe (52), and the gas-liquid separation vertical pipe (50) may be an enlarged pipe compared to the second return pipe (54).

[0039] Since liquid ammonia is separated in the gas-liquid separation vertical pipe (50), purging gas and gaseous ammonia can be supplied to the second return pipe (54) after the gas-liquid separation vertical pipe (50). The second return pipe (54) may include both vertical pipes and horizontal pipes. At least a portion of the second return pipe (54) may have a first enlarged pipe (60) whose diameter is relatively enlarged compared to the first return pipe (52). In the present embodiment, the enlarged pipe of the second return pipe (54) has been described in terms of the relative size compared to the first return pipe (52), but is not limited to the first return pipe (52), and at least a portion of the second return pipe (54) may have a pipe that is enlarged compared to other portions of the second return pipe (54). Since the conventional catch tank is omitted, at least a portion of the second return pipe (54) may have an enlarged pipe in consideration of the amount of gas flowing.

[0040] According to the present invention, a gaseous fuel return line (GFRL) branching from the liquid fuel return line (LFRL) and connected to a vent gas treatment system (30) and through which purging gas and gaseous ammonia are returned may be further included.

[0041] As illustrated in FIG. 1, a return valve train (RVT) may be provided at a point where a liquid fuel return line (LFRL) and a gaseous fuel return line (GFRL) are connected, and a supply valve train (SVT) may be provided at a fuel supply line (FSL). The return valve train (RVT) may be provided with a valve for controlling the flow rate of fuel recovered from the engine (20), etc. The supply valve train (SVT) may be provided with a valve for controlling the flow rate of fuel supplied to the engine (20). The return valve train (RVT) and the supply valve train (SVT) may be integrated into a fuel valve train (80).

[0042] A gaseous fuel return line (GFRL) may be supplied with purging gas and gaseous ammonia. The piping on the gaseous fuel return line (GFRL) may include both vertical piping and horizontal piping. At least a portion of the piping on the gaseous fuel return line (GFRL) may have a second enlarged piping (70) with a relatively enlarged diameter. That is, at least a portion of the piping on the gaseous fuel return line (GFRL) may have an enlarged piping compared to other portions of the piping on the gaseous fuel return line (GFRL). Since the conventional purge tank is omitted, at least a portion of the piping on the gaseous fuel return line (GFRL) may have an enlarged piping considering the amount of gas flowing.

[0043] Therefore, in the present invention, the role of a conventional purge tank can be replaced simply by expanding the pipe, thereby achieving the effects of space saving, cost reduction, and simplification of the operation sequence.

[0044] The extent to which the diameters of the gas-liquid separation vertical pipe (50) and the second expansion pipe (70) are expanded can be determined by at least one of the size of the engine (20), the size of the fuel supply line (FSL), and the size of the liquid fuel return line (LFRL). The pipes can be expanded in consideration of the fact that the flow rate flowing through the pipes can relatively increase because the conventional catch tank and purge tank are omitted.

[0045] In addition, the extent to which the diameter of the first expansion pipe (60) is expanded can be determined by at least one of the amount of purging gas and the amount of gaseous ammonia separated from the gas-liquid separation vertical pipe (50). Since the gas-liquid separation vertical pipe (50) has been expanded, the second return pipe (54) after the gas-liquid separation vertical pipe (50) may also need to be expanded accordingly. Accordingly, the extent of expansion can be determined by considering at least one of the amount of purging gas and the amount of gaseous ammonia separated from the gas-liquid separation vertical pipe (50).

[0046] According to the present invention, a fuel recovery line (LFL) may be further included to supply liquid ammonia separated from the gas-liquid separation vertical pipe (50) to a fuel storage tank (10) or an engine (20). The liquid ammonia separated from the gas-liquid separation vertical pipe (50) may be supplied to the fuel storage tank (10) or the engine (20) for recycling. As illustrated in FIG. 1, the fuel recovery line (LFL) is connected to a fuel supply line (FSL) so that the recovered liquid ammonia may be supplied to the fuel storage tank (10) or the engine (20). In addition, the fuel recovery line (LFL) may be directly connected to the fuel storage tank (10) or the engine (20).

[0047] Hereinafter, the ammonia fuel treatment process inside the engine (20) or the ship fuel supply system (100) will be described. The primary purging gas is supplied from the purging gas supply unit (40) through the purging gas supply line (PSL), and the purging gas is transported together with the ammonia fuel along the liquid fuel return line (LFRL) in the return valve train (RVT) via the engine (20). At this time, the valve (81) on the fuel supply line (FSL) and the valve (83) on the gaseous fuel return line (GFRL) are closed, and the valve (82) on the liquid fuel return line (LFRL) is opened. The ammonia fuel is separated into liquid ammonia and gaseous ammonia in the gas-liquid separation vertical pipe (50). The separated gaseous ammonia is supplied to the vent gas treatment system (30) along the second return pipe (54) (via the first expansion pipe (60)) together with the purging gas. At this time, the valve (84) provided in the second return pipe (54) is opened. In addition, the separated liquid ammonia is supplied to the fuel supply line (FSL) along the fuel return line (LFL) and returned to the fuel storage tank (10) or engine (20). At this time, the valve (85) on the fuel return line (LFL) is opened.

[0048] Secondary purging gas is supplied from the purging gas supply unit (40) through the purging gas supply line (PSL), and the purging gas is transported together with gaseous ammonia along the gaseous fuel return line (GFRL) (via the second expansion pipe (70)) through the return valve train (RVT) via the engine (20). At this time, the valve (81) on the fuel supply line (FSL) and the valve (82) on the liquid fuel return line (LFRL) are closed, and the valve (83) on the gaseous fuel return line (GFRL) is opened.

[0049] Therefore, the ammonia fuel inside the engine (20) or the ship fuel supply system (100) by the primary and secondary purging gases can be recovered to the fuel storage tank (10) or supplied to the vent gas treatment system (30).

[0050]

[0051] <Example 2>

[0052] Referring to FIG. 1, a fuel supply system (100) for a ship according to a first embodiment of the present invention may further include a main vapor line (MVL) connected from a bunker station (90) to a fuel storage tank (10); a first gaseous fuel return line (GFRL1) branched from a liquid fuel return line (LFRL) and connected to the main vapor line (MVL); and a second gaseous fuel return line (GFRL2) branched from the main vapor line (MVL) and connected to a vent gas treatment system (30).

[0053] The separation and recycling of liquid ammonia according to the first purging gas is the same as in the first embodiment, so its description is omitted.

[0054] The main liquid line (MLL) is a line that supplies fuel from the bunker station (90) to the fuel storage tank (10), and the main vapor line (MVL) is a line that returns gas when supplying fuel.

[0055] The first gaseous fuel return line (GFRL1) may be defined as a line branching from the liquid fuel return line (LFRL) and connected to the main vapor line (MVL). In addition, the second gaseous fuel return line (GFRL2) may be defined as a line branching from the main vapor line (MVL) and connected to the vent gas treatment system (30).

[0056] The purging gas and gaseous ammonia according to the secondary purging gas can be supplied to the vent gas treatment system (30) along the first gaseous fuel return line (GFRL1), the main vapor line (MVL), and the second gaseous fuel return line (GFRL2). In the second embodiment, the volume of the main vapor line (MVL) can serve as a purge tank. Therefore, there is an advantage in that the existing main vapor line (MVL) can be utilized without a separate purge tank and expansion pipe.

[0057] Secondary purging gas is supplied from the purging gas supply unit (40) through the purging gas supply line (PSL), and the purging gas is transferred to the main vapor line (MVL) along the first gaseous fuel return line (GFRL1) from the return valve train (RVT) via the engine (20). At this time, the valve (81) on the fuel supply line (FSL) and the valve (82) on the liquid fuel return line (LFRL) are closed, and the valve (86) on the first gaseous fuel return line (GFRL1) is opened. The purging gas and gaseous ammonia can be supplied to the vent gas treatment system (30) through the second gaseous fuel return line (GFRL2) along the main vapor line (MVL). At this time, the valve (89) on the main vapor line (MVL) is closed, and the valve (87) on the second gaseous fuel return line (GFRL2) is open.

[0058] Additionally, the second embodiment may further include a BOG line (BOGL) branching from the fuel supply line (FSL) and connected to a vent gas treatment system. The second gaseous fuel return line (GFRL2) may not be directly connected to the vent gas treatment system (30), but may be connected to the BOG line (BOGL), as illustrated in FIG. 2.

[0059] In this case, the purging gas and gaseous ammonia according to the secondary purging gas can be supplied to the vent gas treatment system (30) along the first gaseous fuel return line (GFRL1), the main vapor line (MVL), the second gaseous fuel return line (GFRL2), and the BOG line (BOGL). At this time, the valve (89) on the main vapor line (MVL) is closed, and the valve (86) on the first gaseous fuel return line (GFRL1), the valve (87) on the second gaseous fuel return line (GFRL2), and the valve (88) on the BOG line (BOGL) are opened.

[0060] Therefore, in the second embodiment, the purging gas and gaseous ammonia according to the secondary purging gas can be supplied to the vent gas treatment system (30) by utilizing the existing main vapor line (MVL) without a separate purge tank and expansion pipe.

[0061]

[0062] The above description is merely an illustrative illustration of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate, rather than limit, the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

Claims

1. As a fuel supply system for ships, Fuel storage tank for storing ammonia fuel; A fuel supply line for supplying ammonia fuel from the above fuel storage tank to the engine; A liquid fuel return line that supplies ammonia fuel returned from the above engine to the vent gas treatment system; and Includes a purging gas supply line connected to the above fuel supply line and supplying purging gas, A fuel supply system for a ship, wherein the liquid fuel return line is provided with a gas-liquid separation vertical pipe for separating liquid ammonia and gaseous ammonia.

2. In claim 1, The liquid fuel return line is provided with the gas-liquid separation vertical pipe, a first return pipe between the engine and the gas-liquid separation vertical pipe, and a second return pipe between the gas-liquid separation vertical pipe and the vent gas treatment system. A fuel supply system for a ship, wherein the above-mentioned gas-liquid separation vertical pipe has a pipe with a relatively enlarged diameter compared to the above-mentioned first return pipe.

3. In claim 2, A fuel supply system for a ship, wherein at least a portion of the second return pipe has a first enlarged pipe having a relatively enlarged diameter compared to the first return pipe.

4. In claim 2, Further comprising a gaseous fuel return line branching from the liquid fuel return line and connected to a vent gas treatment system, through which purging gas and gaseous ammonia are returned; A fuel supply system for a ship, wherein at least a portion of the pipe on the above-mentioned gaseous fuel return line has a second enlarged pipe having a relatively enlarged diameter.

5. In claim 4, A fuel supply system for a ship, wherein the extent to which the diameters of the above-mentioned gas-liquid separation vertical pipe and the above-mentioned second expansion pipe are expanded is determined by at least one of the size of the engine, the size of the fuel supply line, and the size of the liquid fuel return line.

6. In claim 3, A fuel supply system for a ship, wherein the extent to which the diameter of the first expansion pipe is expanded is determined by at least one of the amount of purging gas and the amount of gaseous ammonia separated from the gas-liquid separation vertical pipe.

7. In claim 4, A return valve train is provided at the point where the liquid fuel return line and the gaseous fuel return line are connected. A fuel supply system for a ship having a supply valve train provided in the above fuel supply line.

8. In claim 1, A fuel supply system for a ship further comprising a fuel recovery line for supplying liquid ammonia separated from the above-mentioned gas-liquid separation vertical pipe to the above-mentioned fuel storage tank or engine.

9. In claim 8, The above fuel recovery line is a fuel supply system for a ship connected to the above fuel supply line.

10. In claim 1, A main steam line connecting the bunker station to the above fuel storage tank; A first gaseous fuel return line branching from the liquid fuel return line and connected to the main vapor line; and Further comprising a second gaseous fuel return line branching from the main steam line and connected to the vent gas treatment system; A fuel supply system for a ship, wherein purging gas and gaseous ammonia are supplied to the vent gas treatment system along the first gaseous fuel return line, the main vapor line, and the second gaseous fuel return line.

11. In claim 1, A main steam line connecting the bunker station to the above fuel storage tank; A BOG line branching from the above fuel supply line and connected to the above vent gas treatment system; A first gaseous fuel return line branching from the liquid fuel return line and connected to the main vapor line; and Further comprising a second gaseous fuel return line branching from the main steam line and connected to the BOG line; A fuel supply system for a ship, wherein purging gas and gaseous ammonia are supplied to the vent gas treatment system along the first gaseous fuel return line, the main steam line, the second gaseous fuel return line, and the BOG line.

Images