Watercraft

Abstract

To reduce cost by suppressing an increase in the number of part items, and to secure an installation space for a tank and a pump.SOLUTION: The ship includes a hull, a storage tank configured to store liquid fuel, a fuel line connected to the storage tank, a pump provided in the fuel line and configured to pump the liquid fuel in the storage tank, a heat engine connected to the fuel line and configured to be driven by the liquid fuel supplied via the fuel line, a return line through which the liquid fuel having passed through the heat engine flows together with lubricating oil of the heat engine, a return tank connected to the return line and including a first chamber into which the liquid fuel and the lubricating oil are introduced and a second chamber into which the liquid fuel overflowing the first chamber is introduced, and a connection line configured to connect the second chamber and the fuel line on an upstream side closer to the storage tank than the pump.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a configuration in which ammonia, which is a liquid fuel stored in a storage tank, is supplied to an engine by a supply pump. In this configuration, liquid ammonia returned from the main engine is passed through a filter to remove foreign matter, and then returned to the storage tank. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Utility Model Registration No. 3234399 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when returning liquid fuel returned from the heat engine, which is the main engine, to a storage tank as in Patent Document 1, foreign matter is removed from the liquid fuel through a filter, but the filter cannot completely remove lubricating oil and the like from the heat engine, so when the liquid fuel is returned to the storage tank, there is a possibility that the liquid fuel stored in the storage tank will be contaminated with lubricating oil.

[0005] On the other hand, a service tank for temporarily storing liquid fuel may be provided between the storage tank and the heat engine driven by the liquid fuel. For example, when heavy oil is used as the liquid fuel, the liquid fuel returned from the heat engine is temporarily stored in the service tank together with the liquid fuel supplied from the storage tank, and after being treated, it is supplied to the heat engine as liquid fuel. In this configuration, lubricating oil and the like do not get mixed into the liquid fuel stored in the storage tank. However, the provision of a service tank requires multiple pumps, including a transfer pump for transferring the liquid fuel from the storage tank to the service tank and a supply pump for supplying the liquid fuel from the service tank to the heat engine. This increases the number of parts, which may increase costs. Furthermore, when using a service tank such as the one described above, all of the liquid fuel supplied to the heat engine must pass through the service tank, which requires a large service tank, which may make it difficult to secure the space to install the tank, pump, etc.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a ship that reduces costs by minimizing the increase in the number of parts and that can secure installation space for tanks, pumps, etc. [Means for solving the problem]

[0007] In order to solve the above problems, a ship according to the present disclosure includes a hull, a storage tank, a fuel line, a pump, a heat engine, a return line, a return tank, and a connecting line. The storage tank stores liquid fuel. The fuel line is connected to the storage tank. The pump is provided in the fuel line and pumps the liquid fuel from the storage tank. The heat engine is connected to the fuel line. The heat engine is driven by the liquid fuel supplied via the fuel line. The return line allows the liquid fuel that has passed through the heat engine to flow together with lubricating oil for the heat engine. The return tank has a first chamber and a second chamber. The first chamber is connected to the return line and receives the liquid fuel and the lubricating oil. The second chamber receives the liquid fuel that has overflowed the first chamber. The connecting line connects the second chamber to the fuel line upstream, closer to the storage tank than the pump. [Effects of the Invention]

[0008] According to the ship of the present disclosure, it is possible to reduce costs by suppressing an increase in the number of parts, and to secure installation space for tanks, pumps, etc. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of a vessel according to an embodiment of the present disclosure. [Figure 2] FIG. 1 is a diagram illustrating a configuration of a ship according to a first embodiment of the present disclosure. [Figure 3] FIG. 10 is a diagram illustrating a configuration of a ship according to a second embodiment of the present disclosure. [Figure 4] FIG. 10 is a diagram illustrating a configuration of a ship according to a third embodiment of the present disclosure. [Figure 5] FIG. 10 is a diagram illustrating a configuration of a ship according to a modified example of an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] First Embodiment Hereinafter, a vessel according to an embodiment of the present disclosure will be described with reference to FIGS. (Vessel configuration) As shown in FIG. 1, the ship 1A is fueled by liquid fuel F. In this embodiment, the ship 1A uses methanol as the liquid fuel F. The type of ship 1A is not limited to a specific one. Examples of the type of ship 1A include carriers of liquefied gases such as liquefied natural gas (LNG), carbon dioxide, ammonia, and methanol, ferries, RORO ships (roll-on / roll-off ships), PCTCs (pure car & truck carriers), and passenger ships. As shown in FIGS. 1 and 2, the ship 1A mainly includes a hull 2 ​​(see FIG. 2), a heat engine 10, a storage tank 11, a return tank 12, and a pump 13.

[0011] (Hull configuration) As shown in FIG. 1, the hull 2 ​​has a pair of side walls 3A, 3B, a bottom wall 4, and an upper deck 5, which form its outer hull. The side walls 3A, 3B have a pair of side wall shells that form the port and starboard sides, respectively. The bottom wall 4 has a bottom wall shell that connects the side walls 3A, 3B. The upper deck 5 illustrated in this embodiment is a full-length deck that is exposed to the outside. A superstructure 7 having accommodation areas is formed on the hull 2. Note that the location of the superstructure 7 is merely an example, and it may be located, for example, on the bow 2a side of the hull 2.

[0012] The heat engine 10 is provided inside the hull 2. As shown in FIG. 2, the heat engine 10 is driven by methanol as liquid fuel F stored in a storage tank 11. The heat engine 10 is, for example, an engine (internal combustion engine) that burns the liquid fuel F as fuel. The heat engine 10 is, for example, a main engine that generates propulsive force to propel the ship 1A, or an auxiliary engine that drives a generator that generates electricity used in the ship 1A. The heat engine 10 may also be a boiler that generates steam to be supplied to a steam turbine that drives the generator. The heat engine 10 may be equipped with one or more of these types. The heat engine 10 may also be equipped with a plurality of the same type of heat engines 10.

[0013] The storage tank 11 stores the liquid fuel F. In this embodiment, the storage tank 11 is provided, for example, inside the hull 2. The storage tank 11 may be provided, for example, above the upper deck 5. The storage tank 11 has a rectangular, spherical, cylindrical, or other shape. The storage tank 11 may be provided to store the liquid fuel F to be supplied to the heat engine 10, or may be provided to store the liquid fuel F as cargo. Furthermore, the storage tank 11 is not limited to being separate from the hull 2, and may be configured as part of the hull 2.

[0014] The storage tank 11 and the heat engine 10 are connected via a fuel line 101. The fuel line 101 supplies liquid fuel F to the heat engine 10. One end of the fuel line 101 is connected to the storage tank 11. The other end of the fuel line 101 is connected to the heat engine 10.

[0015] The pump 13 is provided in the fuel line 101. The pump 13 pumps the liquid fuel F from the storage tank 11 to the heat engine 10.

[0016] Liquid fuel F remaining unburned in the heat engine 10 is introduced into the return tank 12 through a return line 102, which will be described later. The liquid fuel F remaining unburned in the heat engine 10 is mixed with the lubricating oil L used in the heat engine 10. Hereinafter, the liquid fuel F mixed with the lubricating oil L may be referred to as a mixed fluid. The return tank 12 is, for example, a rectangular tank. The interior of the return tank 12 is connected to the interior of the storage tank 11 via a connection line 103 and a fuel line 101, which will be described later. The return tank 12 is preferably installed at a height that overlaps at least a portion of the storage tank 11 in the vertical direction Dv. This allows the liquid level in the return tank 12 and the liquid level in the storage tank 11 to be balanced.

[0017] The return tank 12 has a partition wall 12w extending upward from the bottom 12b. The partition wall 12w divides the interior of the return tank 12 into a first chamber 121 and a second chamber 122. The first chamber 121 is formed on one side of the partition wall 12w within the return tank 12. The second chamber 122 is formed on the other side of the partition wall 12w within the return tank 12.

[0018] The return tank 12 further has a guide wall 12g. The guide wall 12g is provided between the partition wall 12w and one side wall portion 12s of the return tank 12. The guide wall 12g extends downward from the top surface portion 12t and is inserted into the first chamber 121. The lower end of the guide wall 12g is located lower than the upper end of the partition wall 12w. The guide wall 12g divides the upper portion of the first chamber 121 into a first region 121a on one side of the guide wall 12g and a second region 121b on the other side of the guide wall 12g.

[0019] The return line 102 sends the liquid fuel F that remains unburned in the heat engine 10, mixed with the lubricating oil L used in the heat engine 10, from the heat engine 10 to the return tank 12. One end of the return line 102 is connected to the heat engine 10. The other end of the return line 102 penetrates the top surface 12t of the return tank 12 and communicates with the first region 121a in the first chamber 121 between the guide wall 12g and the side wall 12s. Note that, although the configuration in which the other end of the return line 102 penetrates the top surface 12t has been shown as an example, the portion through which the other end of the return line 102 penetrates is not limited to the top surface 12t. For example, the other end of the return line 102 may be configured to penetrate an upper portion of the side wall 12s.

[0020] A mixed fluid of the liquid fuel F that remains unburned in the heat engine 10 and the lubricating oil L used in the heat engine 10 is introduced into a first region 121a in a first chamber 121 in the return tank 12 through a return line 102. In the mixed fluid introduced into the first region 121a, the liquid fuel F and the lubricating oil L are separated into upper and lower parts due to the difference in specific gravity between the liquid fuel F and the lubricating oil L.

[0021] In this embodiment, methanol used as the liquid fuel F has a smaller specific gravity than the lubricating oil L. Therefore, the liquid fuel F is separated above the lubricating oil L in the first chamber 121. A waste oil line 105 is connected to the bottom of the return tank 12. The lubricating oil L accumulated at the bottom of the first chamber 121 of the return tank 12 is discharged to the outside of the return tank 12 through the waste oil line 105 at an appropriate time.

[0022] The connection line 103 connects the second chamber 122 of the return tank 12 with the fuel line 101 on the upstream side, which is closer to the storage tank 11 than the pump 13. Here, the return tank 12 is disposed higher in the vertical direction Dv than the connection line 103 and the pump 13. As a result, when the pump 13 is operated, the liquid fuel F introduced into the second chamber 122 of the return tank 12 is sucked by the pump 13 and efficiently flows into the fuel line 101 through the connection line 103 by the action of gravity. The liquid fuel F from the return tank 12 that has flowed into the fuel line 101 joins with the liquid fuel F from the storage tank 11 and is pressure-fed to the heat engine 10 by the pump 13.

[0023] In this configuration, the liquid fuel F stored in the storage tank 11 is sucked by the pump 13 and pumped to the heat engine 10 through the fuel line 101 . A mixed fluid of the liquid fuel F that has passed through the heat engine 10 and remains unburned in the heat engine 10 and the lubricating oil L used in the heat engine 10 is sent to the return tank 12 through the return line 102. In the first chamber 121 in the return tank 12, the mixed fluid of the liquid fuel F and the lubricating oil L is introduced into a first region 121a between the guide wall 12g and the side wall portion 12s.

[0024] The mixed fluid introduced into the first region 121a separates into the liquid fuel F and the lubricating oil L due to the difference in specific gravity between the liquid fuel F and the lubricating oil L. Within the first chamber 121, the liquid fuel F separates above the lubricating oil L. The lubricating oil L that has accumulated at the bottom of the first chamber 121 of the return tank 12 is discharged to the outside of the return tank 12 through the waste oil line 105 at an appropriate time.

[0025] The liquid fuel F accumulated above the lubricating oil L in the first region 121a passes between the lower end of the guide wall 12g and the bottom 12b, and flows into the second region 121b between the guide wall 12g and the partition wall 12w. The liquid fuel F that has flowed into the second region 121b overflows the partition wall 12w and is introduced into the second chamber 122.

[0026] The liquid fuel F introduced into the second chamber 122 flows through the connecting line 103 into the upstream fuel line 101, which is closer to the storage tank 11 than the pump 13, and is pumped by the pump 13 to the heat engine 10 together with the liquid fuel F from the storage tank 11. As the liquid fuel F is consumed in the heat engine 10, the liquid level of the liquid fuel F in the storage tank 11 and the liquid level of the liquid fuel F in the second chamber 122 of the return tank 12 decrease while maintaining equilibrium.

[0027] (Action and effect) In the ship 1A of the above embodiment, the liquid fuel F stored in the storage tank 11 and the liquid fuel F in the second chamber 122 of the return tank 12 are pressure-fed by the pump 13 through the fuel line 101 to the heat engine 10. This allows the liquid fuel F stored in the storage tank 11 to be pressure-fed to the heat engine 10 with a single pump 13, thereby suppressing an increase in the number of parts. Furthermore, the second chamber 122 of the return tank 12 only receives the liquid fuel F that has passed through the heat engine 10 and the first chamber 121, and does not have a function of temporarily storing the liquid fuel F stored in the storage tank 11. This eliminates the need for all of the liquid fuel F supplied to the heat engine 10 to pass through a service tank, allowing the return tank 12 to be made smaller. As a result, it is possible to suppress an increase in the number of parts, reduce costs, and ensure installation space for the return tank 12, the pump 13, etc.

[0028] Second Embodiment Next, a second embodiment of the marine vessel according to the present disclosure will be described. The second embodiment described below differs from the first embodiment only in that it includes a supply switching unit 30. Therefore, the same components as those in the first embodiment will be denoted by the same reference numerals and will not be described again. FIG. 3 is a diagram illustrating a configuration of a marine vessel according to a second embodiment of the present disclosure. As shown in FIG. 3, a ship 1B of the second embodiment includes a supply switching unit 30 in addition to the components of the ship 1A shown in the first embodiment.

[0029] The supply switching unit 30 includes a liquid level sensor 31 and a switching valve 32. The liquid level sensor 31 detects the liquid level in the second chamber 122 of the return tank 12. The switching valve 32 is a so-called three-way valve provided at the connection between the connection line 103 and the fuel line 101. The switching valve 32 is capable of switching between supplying the liquid fuel F from the storage tank 11 to the heat engine 10 through the fuel line 101 and supplying the liquid fuel F from the return tank 12 to the heat engine 10 through the connection line 103. The switching valve 32 may be opened and closed manually or remotely by an operator based on the liquid level detected by the liquid level sensor 31, or may be automatically opened and closed by a controller (not shown). This allows the liquid fuel F to be supplied from the return tank 12 regardless of the liquid level of the liquid fuel F in the storage tank 11.

[0030] Specifically, for example, when the liquid level of the liquid fuel F in the second chamber 122 detected by the liquid level sensor 31 is below a preset level, the switching valve 32 supplies the liquid fuel F from the storage tank 11 to the heat engine 10 through the fuel line 101, and does not supply the liquid fuel F from the return tank 12 to the heat engine 10 through the connection line 103. Also, when the liquid level of the liquid fuel F in the second chamber 122 detected by the liquid level sensor 31 is equal to or higher than the preset level, the switching valve 32 does not supply the liquid fuel F from the storage tank 11 to the heat engine 10 through the fuel line 101, and supplies the liquid fuel F from the return tank 12 to the heat engine 10 through the connection line 103.

[0031] According to the ship 1B of the second embodiment described above, by being equipped with a liquid level sensor 31 and a supply switching unit 30, it is possible to switch between supplying liquid fuel F from the storage tank 11 to the heat engine 10 and supplying liquid fuel F from the return tank 12 to the heat engine 10 depending on the liquid level. Furthermore, in the ship 1B, similarly to the first embodiment, an increase in the number of parts can be suppressed to reduce costs, and installation space for the return tank 12, the pump 13, etc. can be secured.

[0032] Third Embodiment Next, a third embodiment of a marine vessel according to the present disclosure will be described. The third embodiment described below differs from the first and second embodiments only in that it includes an on / off switching unit 40. Therefore, the same components as those in the first and second embodiments will be denoted by the same reference numerals and will not be described again. FIG. 4 is a diagram illustrating a configuration of a marine vessel according to a third embodiment of the present disclosure. As shown in FIG. 4, a boat 1C according to the third embodiment includes an on / off switching unit 40 in addition to the components of the boat 1A shown in the first embodiment.

[0033] The on / off switching unit 40 includes a liquid level sensor 41 and an on / off valve 42. The liquid level sensor 41 detects the liquid level in the second chamber 122 of the return tank 12. The on / off valve 42 is provided midway along the connection line 103. The on / off valve 42 is capable of opening and closing the flow path in the connection line 103. The on / off valve 42 interrupts the flow of liquid fuel F from the second chamber 122 of the return tank 12 that flows through the connection line 103. The on / off switching unit 40 opens and closes the on / off valve 42 based on the liquid level detected by the liquid level sensor 41, thereby interrupting the supply of liquid fuel F from the return tank 12 to the heat engine 10. This allows the liquid fuel F to be supplied from the return tank 12 regardless of the liquid level of the liquid fuel F in the storage tank 11.

[0034] Specifically, for example, when the liquid level of the liquid fuel F in the second chamber 122 detected by the liquid level sensor 41 is below a preset level, the on-off valve 42 is closed and the connection line 103 is cut off. As a result, the liquid fuel F is not supplied from the return tank 12 to the heat engine 10 through the connection line 103, and only the liquid fuel F is supplied from the storage tank 11 to the heat engine 10 through the fuel line 101. Furthermore, when the liquid level of the liquid fuel F in the second chamber 122 detected by the liquid level sensor 41 is equal to or higher than the preset level, the on-off valve 42 is opened. As a result, in addition to the supply of liquid fuel F from the storage tank 11 to the heat engine 10 through the fuel line 101, the liquid fuel F is supplied from the return tank 12 to the heat engine 10.

[0035] In the marine vessel 1C of the third embodiment, the on / off switching unit 40 is provided, so that the supply of the liquid fuel F from the return tank 12 to the heat engine 10 can be switched on and off as needed. Furthermore, in the ship 1C, similarly to the first embodiment, an increase in the number of parts can be suppressed to reduce costs, and installation space for the return tank 12, the pump 13, etc. can be secured.

[0036] (Other embodiments) The above describes in detail the embodiments of the present disclosure with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present disclosure. FIG. 5 is a diagram illustrating a configuration of a ship according to a modified example of the embodiment of the present disclosure. In the above embodiments, the fuel line 101 is provided with the pump 13. However, as shown in FIG. 5, the fuel line 101 may be provided with a plurality of pumps 13A, 13B in series. According to this configuration, the liquid fuel F sent to the heat engine 10 through the fuel line 101 is pressurized by the first-stage pump 13A, and then further pressurized by the second-stage pump 13B. This makes it possible to increase the pressure of the liquid fuel F supplied to the heat engine 10.

[0037] <Additional Notes> The ships 1A to 1C described in each embodiment can be understood, for example, as follows.

[0038] (1) Ships 1A to 1C according to a first aspect of the present invention comprise a hull 2, a storage tank 11 for storing liquid fuel F, a fuel line 101 connected to the storage tank 11, a pump 13 provided in the fuel line 101 for pumping the liquid fuel F from the storage tank 11, a heat engine 10 connected to the fuel line 101 and driven by the liquid fuel F supplied via the fuel line 101, a return line 102 through which the liquid fuel F that has passed through the heat engine 10 flows together with lubricating oil L for the heat engine 10, a return tank 12 connected to the return line 102 and having a first chamber 121 into which the liquid fuel F and the lubricating oil L are introduced and a second chamber 122 into which the liquid fuel F that has overflowed the first chamber 121 is introduced, and a connection line 103 connecting the second chamber 122 to the fuel line 101 upstream and closer to the storage tank 11 than the pump 13.

[0039] In these ships 1A to 1C, liquid fuel F stored in a storage tank 11 is pressure-fed to a heat engine 10 through a fuel line 101 by a pump 13. The liquid fuel F that has passed through the heat engine 10 is introduced into a first chamber 121 of a return tank 12 through a return line 102 together with lubricating oil L for the heat engine 10. In the first chamber 121 of the return tank 12, the liquid fuel F and the lubricating oil L are separated into upper and lower parts due to the difference in specific gravity. The liquid fuel F that has overflowed the first chamber 121 is introduced into a second chamber 122 of the return tank 12. The liquid fuel F introduced into the second chamber 122 of the return tank 12 flows through a connecting line 103 into the fuel line 101 on the upstream side, which is closer to the storage tank 11 than the pump 13, and is pressure-fed to the heat engine 10 by the pump 13 together with the liquid fuel F from the storage tank 11. In this way, the liquid fuel F stored in the storage tank 11 can be pumped to the heat engine 10 with a single pump 13, thereby suppressing an increase in the number of parts. Furthermore, only the liquid fuel F that has passed through the heat engine 10 and the first chamber 121 is introduced into the second chamber 122 of the return tank 12, and does not have the function of temporarily storing the liquid fuel F stored in the storage tank 11. Therefore, it is no longer necessary for all of the liquid fuel F supplied to the heat engine 10 to pass through the service tank, and the return tank 12 can be made smaller than a service tank. As a result, it is possible to suppress an increase in the number of parts, reduce costs, and ensure installation space for the return tank 12, pump 13, etc.

[0040] (2) The ship 1B according to the second aspect is the ship 1B of (1), further comprising a supply switching unit 30 that can switch between the supply of the liquid fuel F from the storage tank 11 to the heat engine 10 and the supply of the liquid fuel F from the return tank 12 to the heat engine 10.

[0041] Thus, by providing the supply switching unit 30, it is possible to switch between supplying the liquid fuel F from the storage tank 11 to the heat engine 10 and supplying the liquid fuel F from the return tank 12 to the heat engine 10 as needed.

[0042] (3) The ship 1C according to the third aspect is the ship 1C of (1) or (2), further comprising an on / off switching unit 40 that enables the supply of the liquid fuel F from the return tank 12 to the heat engine 10 to be switched on and off.

[0043] Thus, by providing the on / off switching unit 40, the supply of the liquid fuel F from the return tank 12 to the heat engine 10 can be switched on and off as needed.

[0044] (4) The ships 1A to 1C according to a fourth aspect are any one of the ships 1A to 1C according to (1) to (3), in which the liquid fuel F is methanol.

[0045] As a result, when the liquid fuel F is methanol, it is possible to suppress an increase in the number of parts, thereby reducing costs, and also to ensure installation space for the tank, pump 13, etc. [Explanation of symbols]

[0046] 1A~1C…Ship 2...Hull 2a…bow 3A, 3B...Side 4... Bottom of the ship 5...Upper deck 7...Superstructure 10...Heat engine 11...Storage tank 12...Return tank 12b…Bottom 12g...Guide wall 12s...Side wall part 12t…Top section 12w...Partition wall 13, 13A, 13B...Pump 30...Supply switching unit 31...Liquid level sensor 32...Switching valve 40...Intermittent switching section 41...Liquid level sensor 42...Shut-off valve 101...Fuel line 102...Return line 103...connection line 105…Abandoned oil イン 121…First Room 121a…First Domain 121b…Second Domain 122…Second Room F…liquid fuel L…lubricating oil

Claims

1. The hull and a storage tank for storing liquid fuel; a fuel line connected to the storage tank; a pump provided in the fuel line for pumping the liquid fuel in the storage tank; a heat engine connected to the fuel line and driven by the liquid fuel supplied through the fuel line; a return line through which the liquid fuel that has passed through the heat engine flows together with lubricating oil for the heat engine; a return tank having a first chamber connected to the return line into which the liquid fuel and the lubricating oil are introduced, and a second chamber into which the liquid fuel that has overflowed the first chamber is introduced; a connecting line connecting the second chamber and the fuel line on an upstream side closer to the storage tank than the pump; A vessel equipped with:

2. a supply switching unit that can switch between supplying the liquid fuel from the storage tank to the heat engine and supplying the liquid fuel from the return tank to the heat engine.

2. The watercraft of claim 1.

3. an on / off switching unit that can interrupt the supply of the liquid fuel from the return tank to the heat engine.

3. A vessel according to claim 1 or 2.

4. The liquid fuel is methanol.

3. A vessel according to claim 1 or 2.

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