Liquid fuel-using equipment, floating structures, and operating methods for liquid fuel-using equipment

Abstract

The liquid fuel discharged through purging can be easily reused. [Solution] The liquid fuel usage equipment comprises a fuel tank having a fuel storage space, a combustion device driven by liquid fuel, a fuel supply line that supplies liquid fuel from the fuel tank to the combustion device, a purge liquid supply unit capable of supplying a purge liquid soluble in the liquid fuel to the liquid fuel flow path, a recovery line that recovers the discharge liquid pushed out from the liquid fuel flow path by the supply of purge liquid by the purge liquid supply unit, a recovery tank having a liquid storage space capable of storing the discharge liquid recovered through the recovery line, and a mixing line that mixes the discharge liquid in the recovery tank with the liquid fuel supplied to the combustion device through the fuel supply line, wherein the horizontal cross-sectional area of ​​the fuel storage space at the same height in the vertical direction is larger than the horizontal cross-sectional area of ​​the liquid storage space.

Description

Technical Field

[0001] The present disclosure relates to liquid fuel using equipment, floating bodies, and a method for operating liquid fuel using equipment.

Background Art

[0002] Patent Document 1 discloses a configuration in which combustible gas remaining in a pipe or the like of an engine driven by combustible gas (fuel) is purged with nitrogen gas or the like and discharged into the atmosphere outside the ship through a vent post.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, fuels harmful to the human body such as methanol may be used as fuels for engines and the like. Such fuels need to be purged using a purge fluid before engine maintenance. Thus, since fuels harmful to the human body cannot be discharged into the atmosphere, the sea, or the like, it is desired to reuse the fuel discharged by purging without discarding it. However, since the fuel discharged by purging is discharged together with the purge fluid, complicated device configurations, controls, and the like are required to reuse the fuel discharged by purging, and there is a problem that the fuel discharged by purging cannot be easily reused.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a liquid fuel using equipment, a floating body, and a method for operating a liquid fuel using equipment that can easily reuse the liquid fuel discharged by purging.

Means for Solving the Problems

[0006] To solve the above problems, the liquid fuel-using equipment, floating body, and operating method for the liquid fuel-using equipment according to this disclosure comprises a fuel tank, a combustion device, a fuel supply line, a purge liquid supply unit, a recovery line, a recovery tank, and a mixing line. The fuel tank has a fuel storage space capable of storing liquid fuel. The combustion device is driven by the liquid fuel. The fuel supply line supplies the liquid fuel from the fuel tank to the combustion device. The purge liquid supply unit can supply a purge liquid soluble in the liquid fuel to the liquid fuel flow path. The recovery line recovers the discharge liquid pushed out of the liquid fuel flow path by the supply of the purge liquid by the purge liquid supply unit. The recovery tank has a liquid storage space capable of storing the discharge liquid recovered through the recovery line. The mixing line mixes the discharge liquid in the recovery tank with the liquid fuel supplied to the combustion device through the fuel supply line. The horizontal cross-sectional area of ​​the fuel storage space at the same vertical height is larger than the horizontal cross-sectional area of ​​the liquid storage space.

[0007] The floating structure relating to this disclosure comprises a floating structure body and liquid fuel-using equipment as described above.

[0008] The method for operating a liquid fuel-using equipment according to this disclosure is a method for operating a liquid fuel-using equipment as described above, and includes the steps of: driving a combustion device with liquid fuel; supplying a purge liquid to the liquid fuel flow path; recovering discharge liquid in a recovery tank; and mixing the discharge liquid with liquid fuel and driving the combustion device. In the step of driving the combustion device with liquid fuel, the liquid fuel in the fuel tank is supplied to the combustion device through the fuel supply line and the combustion device is driven. In the step of supplying a purge liquid to the liquid fuel flow path, the operation of the combustion device is stopped and the purge liquid is supplied from the purge liquid supply unit to the liquid fuel flow path. In the step of recovering discharge liquid in a recovery tank, the discharge liquid pushed out by the purge liquid supplied to the liquid fuel flow path is recovered in the recovery tank through the recovery line. In the step of mixing the discharge liquid with liquid fuel to drive the combustion device, the discharge liquid stored in the recovery tank is mixed with the liquid fuel circulating in the fuel supply line and supplied to the combustion device to drive the combustion device. [Effects of the Invention]

[0009] According to the liquid fuel-using equipment, floating body, and operating method of the liquid fuel-using equipment described herein, the liquid fuel discharged by purging can be easily reused. [Brief explanation of the drawing]

[0010] [Figure 1] This is a side view of a floating body equipped with a liquid fuel usage facility according to an embodiment of the present disclosure. [Figure 2] This figure shows the configuration of a liquid fuel-using equipment according to an embodiment of this disclosure. [Figure 3] This figure shows a recovery tank and a service tank according to an embodiment of the present disclosure. [Figure 4] This flowchart shows the procedure for operating a liquid fuel-using facility according to the embodiment of this disclosure. [Figure 5] This figure shows the step of driving a combustion device with liquid fuel in the operating method of a liquid fuel-using equipment according to the embodiment of this disclosure. [Figure 6] This figure shows the steps of supplying a purge liquid to the liquid fuel flow path and recovering the discharge liquid in a recovery tank, in an operating method for a liquid fuel-using facility according to an embodiment of the present disclosure. [Figure 7] This figure shows a step in the operation method of a liquid fuel-using equipment according to an embodiment of the present disclosure, in which the discharge liquid is mixed with liquid fuel to drive the combustion device. [Figure 8] This figure shows a state in which the liquid level in the service tank is higher than the liquid level in the recovery tank in a liquid fuel usage facility according to the embodiment of this disclosure. [Figure 9] This figure shows a liquid fuel usage system according to an embodiment of the present disclosure, where the liquid level in the service tank is lower than the lower end of the liquid storage space in the recovery tank. [Figure 10] This figure shows a recovery tank and a service tank according to a modified embodiment of the present disclosure. [Modes for carrying out the invention]

[0011] <Embodiment> Hereinafter, a liquid fuel-using equipment and an operating method for the liquid fuel-using equipment according to the embodiments of this disclosure will be described with reference to Figures 1 to 10. In this embodiment, the case in which the liquid fuel-using equipment is installed on a floating body will be described as an example. (Structure of the floating body) As shown in Fig. 1, the floating body 1 includes at least a floating body main body 2 and a liquid fuel-using facility 10. The floating body 1 in this embodiment is a ship that can navigate by means of a main engine or the like. The type of the floating body 1 is not limited to a specific one. Examples of the type of the floating body 1 include carriers for 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), passenger ships, and the like. In this embodiment, the case where the floating body 1 is a ship will be described, but the floating body 1 is not limited to a ship and may be an FSU (Floating Storage Unit), an FSRU (Floating Storage and Regasification Unit), etc. that cannot navigate by means of a main engine or the like.

[0012] (Configuration of the floating body main body) The floating body main body 2 has a pair of side plates 3A and 3B, a bottom plate 4, and an upper deck 5 that form its outer shell. The upper deck 5 illustrated in the first embodiment is an all-through deck exposed to the outside. An upper structure 7 having a living area is formed on the floating body main body 2. Note that the position of the upper structure 7 is merely an example and is not limited to the arrangement shown in Fig. 1.

[0013] (Configuration of the liquid fuel-using facility) Fig. 2 is a diagram showing the configuration of the liquid fuel-using facility according to the embodiment of the present disclosure. As shown in Fig. 2, the liquid fuel-using facility 10 in this embodiment is housed in a section such as an engine area or a fuel preparation area in the floating body main body 2. The liquid fuel-using facility 10 mainly includes a combustion device 11, a storage tank 12, a service tank (fuel tank) 13, a purge liquid supply unit 14, and a recovery tank 15.

[0014] The combustion device 11 is operated by liquid fuel. The combustion device 11 in this embodiment uses methanol as the liquid fuel. The combustion device 11 is provided, for example, inside the floating body main body 2. The combustion device 11 is installed, for example, in an engine room (not shown) of the floating body main body 2.

[0015] As an example of the combustion device 11, there is one that generates thermal energy by burning methanol, which is a liquid fuel. Examples of such a combustion device include an internal combustion engine used as a main engine for propelling the floating body 1, an internal combustion engine used for a power generation facility that supplies electricity into the floating body 1, and the like. The combustion device 11 may be, for example, a boiler or the like that generates steam as a working fluid.

[0016] The storage tank 12 can store the methanol L1. The storage tank 12 may store the methanol L1 for use as fuel in the floating body 1. Further, the storage tank 12 may store the methanol L1 as a cargo. The storage tank 12 may be installed below the upper deck 5 of the floating body main body 2 (see FIG. 1), or may be installed on the upper deck 5. In this embodiment, the case where the storage tank 12 is installed at a position close to the stern 2b on the upper deck 5 (see FIG. 1) is illustrated. The storage tank 12 is provided with a pump 102 for discharging the methanol L1 in the storage tank 12 through a transfer line 101 described later.

[0017] The service tank 13 can temporarily store the methanol L1 supplied to the combustion device 11. The service tank 13 is installed in the floating body main body 2, for example, in an engine room where the combustion device 11 is installed, a fuel preparation room, or the like. The service tank 13 is connected to the storage tank 12 via the transfer line 101. A pump 102 is provided in the middle of the transfer line 101. The pump 102 transfers the methanol L1 in the storage tank 12 to the service tank 13 through the transfer line 101. By driving this pump 102, the methanol L1 is intermittently supplied from the storage tank 12 to the service tank 13 through the transfer line 101.

[0018] The service tank 13 has a fuel storage space 13S inside which methanol L1 can be stored. The shape of the service tank 13 can be a cylindrical or rectangular tube extending in the vertical direction Dv. In this embodiment, the fuel storage space 13S has the same cross-sectional shape along the vertical direction Dv. In other words, the fuel storage space 13S has a constant horizontal cross-sectional area along the vertical direction Dv.

[0019] The service tank 13 is connected to the combustion device 11 via a fuel supply line 103. The first end 103a of the fuel supply line 103 is connected to the bottom of the service tank 13. The second end 103b of the fuel supply line 103 is connected to the fuel inlet of the combustion device 11.

[0020] A pump 104 is provided in the middle of the fuel supply line 103. The pump 104 supplies methanol L1 from the service tank 13 to the combustion device 11 through the fuel supply line 103. A shut-off valve 103v is also provided in the middle of the fuel supply line 103. By opening and closing this shut-off valve 103v, the supply of methanol L1 to the combustion device 11 through the fuel supply line 103 can be intermittently controlled. Although the explanation has used the case where a pump 104 is provided in the middle of the fuel supply line 103 as an example, the pump 104 can be omitted if methanol L1 can be supplied to the combustion device 11 by gravity alone.

[0021] The purge liquid supply unit 14 is capable of supplying purge liquid L2, which is soluble in methanol L1 (liquid fuel), to the methanol L1 flow path. In this embodiment, the purge liquid supply unit 14 supplies clean water as the purge liquid L2, which is soluble in methanol L1. The purge liquid supply unit 14 comprises a purge liquid storage tank 141, a purge liquid supply line 142, and a pump 143.

[0022] The purge liquid storage tank 141 is located inside the floating body 2 and is capable of storing purge liquid L2 (fresh water). The purge liquid storage tank 141 is connected to the middle of the fuel supply line 103 via the purge liquid supply line 142. The purge liquid supply line 142 is connected to the fuel supply line 103 at the point between the on-off valve 103v and the combustion device 11.

[0023] Pump 143 is located in the middle of the purge fluid supply line 142. Pump 143 supplies purge fluid L2 (fresh water) from the purge fluid storage tank 141 to the combustion device 11 through the purge fluid supply line 142 and a portion of the fuel supply line 103. An on-off valve 142v is also provided in the middle of the purge fluid supply line 142, and by opening and closing the on-off valve 142v, the supply of purge fluid L2 through the purge fluid supply line 142 can be intermittently controlled. Note that another tank (not shown) may be provided between pump 143 and on-off valve 142v.

[0024] The purge liquid L2 supplied from the purge liquid storage tank 141 is capable of purging at least a portion of the methanol L1 flow path in the liquid fuel usage equipment 10, for example, prior to maintenance of the combustion device 11. In this embodiment, the purge liquid L2 purges the methanol L1 flow path in the combustion device 11 and the methanol L1 flow path in the fuel supply line 103 on the combustion device 11 side of the on-off valve 103v. The area to be purged by the purge liquid L2 may include other parts as well.

[0025] The recovery tank 15 stores the discharge liquid L3 that is pushed out of the methanol L1 flow path by the supply of purge liquid L2 by the purge liquid supply unit 14. The recovery tank 15 is connected to the combustion device 11 via the recovery line 107. The first end 107a of the recovery line 107 is connected to the outlet of the methanol L1 flow path in the combustion device 11. The second end 107b of the recovery line 107 is connected to the recovery tank 15. The recovery line 107 recovers the discharge liquid L3 that is pushed out of the outlet of the methanol L1 flow path in the combustion device 11 by the supply of purge liquid L2 by the purge liquid supply unit 14. This discharge liquid L3 contains the purge liquid L2 and methanol L1 that remained in the methanol L1 flow path of the combustion device 11 and part of the fuel supply line 103.

[0026] A shut-off valve 107v is provided in the middle of the recovery line 107, and by opening and closing the shut-off valve 107v, the discharge of the waste liquid L3 through the recovery line 107 can be intermittently controlled. Note that the shut-off valve 107v is not limited to the middle of the recovery line 107, but may also be provided, for example, inside the engine (combustion device 11).

[0027] The recovery tank 15 has a liquid storage space 15S capable of storing the discharged liquid L3 recovered through the recovery line 107. The shape of the recovery tank 15 can be, for example, a cylindrical or rectangular shape extending in the vertical direction Dv. In this embodiment, the liquid storage space 15S has the same cross-sectional shape along the vertical direction Dv. In other words, the liquid storage space 15S has a uniform horizontal cross-sectional area along the vertical direction Dv.

[0028] Figure 3 shows a recovery tank and a service tank according to an embodiment of the present disclosure. As shown in Figure 3, in the vertical direction Dv, the entire liquid storage space 15S of the recovery tank 15 is located within the range where the fuel storage space 13S of the service tank 13 is situated. In other words, when viewed from the horizontal direction, the entire liquid storage space 15S overlaps with the fuel storage space 13S. In this embodiment, the fuel storage space 13S extends above the liquid storage space 15S of the recovery tank 15 in the vertical direction Dv. Also, in this embodiment, the fuel storage space 13S extends below the liquid storage space 15S of the recovery tank 15 in the vertical direction Dv.

[0029] At the same height in the vertical direction Dv, the horizontal cross-sectional area A1 of the fuel storage space 13S is larger than the horizontal cross-sectional area A2 of the liquid storage space 15S. Furthermore, the ratio A2 / A1 of the horizontal cross-sectional area A1 of the fuel storage space 13S to the horizontal cross-sectional area A2 of the liquid storage space 15S at the same height in the vertical direction Dv is set to be less than or equal to the upper limit mixing ratio of the discharge liquid L3 to methanol L1 that can be burned by the combustion device 11. Here, if the upper limit mixing ratio of the discharge liquid L3 to the methanol L1 that can be burned by the combustion device 11 of this embodiment is, for example, 0.1, then it is preferable that the ratio A2 / A1 of the horizontal cross-sectional area A1 of the fuel storage space 13S and the horizontal cross-sectional area A2 of the liquid storage space 15S at the same height in the vertical direction Dv be 0.1 or less over the entire vertical direction Dv of the liquid storage space 15S.

[0030] The first end 109a of the mixing line 109 is connected to the recovery tank 15. The second end 109b of the mixing line 109 is connected to the fuel supply line 103 at a point on the service tank 13 side of the on-off valve 103v (see Figure 1). The mixing line 109 mixes the discharge liquid L3 in the recovery tank 15 with methanol L1 supplied to the combustion device 11 through the fuel supply line 103.

[0031] A check valve 21 is provided in the middle of the mixing line 109. The check valve 21 prevents the backflow of methanol L1 from the fuel supply line 103 to the recovery tank 15.

[0032] In a liquid fuel-using facility 10 with this configuration, during normal operation, the combustion device 11 is driven by methanol L1 in the service tank 13, which is supplied through the fuel supply line 103 by the drive of the pump 104.

[0033] Furthermore, for example, when performing maintenance on the combustion device 11, prior to maintenance, the methanol L1 passage in the combustion device 11 and the methanol L1 passage in a portion of the fuel supply line 103 are purged with purge liquid L2. To do this, the purge liquid supply unit 14 supplies the purge liquid L2 to the methanol L1 passages in the combustion device 11 and a portion of the fuel supply line 103.

[0034] The supply of the purging liquid L2 pushes methanol L1 out of the methanol L1 flow path and purges (replaces) it with the purging liquid L2. The discharged liquid L3 pushed out of the methanol L1 flow path by the supply of purging liquid L2 by the purging liquid supply unit 14 is stored in the liquid storage space 15S of the recovery tank 15 through the recovery line 107. After purging the methanol L1 flow path with the purging liquid L2 in this manner, maintenance of the combustion device 11 is performed.

[0035] When restarting the combustion device 11 after performing maintenance on it, the wastewater L3 stored in the recovery tank 15 is mixed with the methanol L1 supplied to the combustion device 11 and then supplied to the combustion device 11. The methanol L1 contained in the wastewater L3 that is pushed out of the methanol L1 flow path is mixed with the methanol L1 supplied to the combustion device 11 and consumed by the combustion device 11.

[0036] (Operating procedures for equipment using liquid fuel) Next, we will explain the operating method for the liquid fuel-using equipment described above. Figure 4 is a flowchart showing the procedure for operating a liquid fuel-using equipment according to an embodiment of this disclosure. Figure 5 is a diagram showing the step of driving the combustion device with liquid fuel in the operating method of the liquid fuel-using equipment according to an embodiment of this disclosure. Figure 6 is a diagram showing the step of supplying purge liquid to the liquid fuel flow path and the step of recovering the discharge liquid in a recovery tank in the operating method of the liquid fuel-using equipment according to an embodiment of this disclosure. Figure 7 is a diagram showing the step of mixing the discharge liquid with liquid fuel to drive the combustion device in the operating method of the liquid fuel-using equipment according to an embodiment of this disclosure.

[0037] As shown in Figure 4, the operating method S10 of the liquid fuel-using equipment 10 includes the steps of: driving the combustion device with liquid fuel S11; supplying purge liquid to the liquid fuel flow path S12; recovering the discharge liquid in a recovery tank S13; and mixing the discharge liquid with the liquid fuel and driving the combustion device S14. The opening and closing operations of the on-off valves 103v, 107v, and 142v, and the driving and stopping operations of the pumps 102, 104, and 143 in each of the following steps S11 to S14 can be performed manually by the crew of the floating body 1 or by automatic control.

[0038] Step S11, which drives the combustion device with liquid fuel, is performed when the liquid fuel-using equipment 10 is in normal operation. As shown in Figure 5, in step S11, which drives the combustion device with liquid fuel, valves 107v and 142v are closed and valve 103v is opened. With this in place, the pump 104 is started and methanol L1 is supplied from the service tank 13 to the combustion device 11, thereby driving the combustion device 11.

[0039] The steps from S12 onward, which involve supplying purge fluid to the liquid fuel flow path, are performed, for example, when performing maintenance on the combustion device 11. As shown in Figure 6, in step S12, which involves supplying purge fluid to the liquid fuel flow path, the pump 104 is stopped and the on-off valve 103v is closed. This stops the operation of the combustion device 11. Next, purge liquid L2 is supplied from the purge liquid supply unit 14 to the methanol L1 flow path. This is done by opening the on-off valves 142v and 107v and driving the pump 143. As a result, the purge liquid L2 is supplied from the purge liquid storage tank 141 through the purge liquid supply line 142 to the portion of the fuel supply line 103 on the combustion device 11 side of the on-off valve 103v and to the methanol L1 flow path in the combustion device 11. This purge liquid L2 pushes out methanol L1 from the portion of the fuel supply line 103 on the combustion device 11 side of the on-off valve 103v and from the methanol L1 flow path in the combustion device 11, and purges (replaces) it with the purge liquid L2.

[0040] When the purge liquid L2 is supplied to the methanol L1 flow path in step S12, the discharge liquid L3 is pushed by the supplied purge liquid L2 and discharged from the purge liquid L2 outlet of the combustion device 11. In step S13, which involves recovering the discharged liquid into a recovery tank, the discharged liquid L3 that is pushed into the recovery line 107 by step S12 is recovered and stored in the recovery tank 15. This step S13 is performed in parallel with step S12.

[0041] After the purging of the methanol L1 flow path with the purge liquid L2 is complete, close the on-off valves 142v and 107v. Alternatively, the pump 143 may be stopped after closing the on-off valve 142v. After that, maintenance will be performed on the combustion device 11.

[0042] After the maintenance of the combustion device 11 is completed, step S14 is performed to mix the discharge liquid with liquid fuel and drive the combustion device. As shown in Figure 7, in step S14 to mix the discharge liquid with liquid fuel and drive the combustion device, valves 107v and 142v are closed and valve 103v is opened. In this state, pump 104 is driven. As a result, a mixture L4 of discharge liquid L3 and methanol L1 is supplied to the combustion device 11 and the combustion device 11 is driven.

[0043] Figure 8 shows a liquid fuel usage facility according to an embodiment of the present disclosure, in which the liquid level in the service tank is higher than the liquid level in the recovery tank. When carrying out step S14, the liquid level of methanol L1 in the service tank 13 is set higher than the liquid level of discharged liquid L3 in the recovery tank 15, as shown in Figure 8. Then, first, only methanol L1 is supplied from the service tank 13 to the combustion device 11 through the fuel supply line 103. After that, as shown in Figure 3, the liquid level of methanol L1 in the service tank 13 becomes the same height as the liquid level of discharged liquid L3 in the recovery tank 15 in the vertical direction Dv. Although the example given shows the liquid level of methanol L1 in the service tank 13 being higher than the liquid level of discharged liquid L3 in the recovery tank 15 in the vertical direction Dv, the liquid level of methanol L1 in the service tank 13 may be set to match the liquid level of discharged liquid L3 in the recovery tank 15 from the beginning.

[0044] When the liquid level of methanol L1 in the service tank 13 reaches the same height as the liquid level of discharged liquid L3 in the recovery tank 15 in the vertical direction Dv, the discharged liquid L3 stored in the recovery tank 15 is supplied to the fuel supply line 103 through the mixing line 109. As a result, the discharged liquid L3 is mixed with the methanol L1 supplied to the combustion device 11. At this time, the discharged liquid L3 contained in the liquid containment space 15S and the methanol L1 contained in the fuel containment space 13S are mixed while maintaining the same liquid level in the vertical direction Dv. The methanol L1 passing through the fuel supply line 103 and the discharged liquid L3 containing the purge liquid L2 passing through the mixing line 109 are mixed in a mixing ratio corresponding to the ratio A2 / A1 of the horizontal cross-sectional area A1 of the fuel containment space 13S and the horizontal cross-sectional area A2 of the liquid containment space 15S at the same height in the vertical direction Dv. The mixture L4, which is a mixture of the discharge liquid L3 and methanol L1, is supplied to the combustion device 11 (see Figure 7) through the fuel supply line 103 and drives the combustion device 11.

[0045] Figure 9 shows a liquid fuel usage facility according to an embodiment of the present disclosure, in which the liquid level in the service tank is lower than the lower end of the liquid storage space in the recovery tank. Subsequently, as shown in Figure 9, once all of the discharge liquid L3 from the recovery tank 15 has been discharged and the level of methanol L1 in the service tank 13 is lower than the lower end of the liquid storage space 15S of the recovery tank 15, only methanol L1 will be supplied from the service tank 13 to the combustion device 11 through the fuel supply line 103. At this point, if the liquid level in the service tank 13 falls below a predetermined level, methanol L1 may be automatically replenished from the storage tank 12 to the service tank 13.

[0046] (Effects and Benefits) In the liquid fuel-using equipment 10 and floating body 1 of the above embodiment, the combustion device 11 is driven by methanol L1 in the service tank 13 supplied through the fuel supply line 103. By supplying purge liquid L2 to the methanol L1 flow path by the purge liquid supply unit 14, methanol L1 is pushed out of the methanol L1 flow path and purged (replaced) by the purge liquid L2. The discharged liquid L3 pushed out of the methanol L1 flow path by the supply of purge liquid L2 by the purge liquid supply unit 14 is stored in the liquid storage space 15S of the recovery tank 15 through the recovery line 107. The discharged liquid L3 stored in the recovery tank 15 can be mixed with methanol L1 supplied to the combustion device 11 through the mixing line 109. At this time, the discharged liquid L3 stored in the liquid storage space 15S and the methanol L1 stored in the fuel storage space 13S are mixed while maintaining the same liquid level in the vertical direction Dv. Since the purge liquid L2 is soluble in methanol L1, the separation of the purge liquid L2 and methanol L1 contained in the discharge liquid L3 is suppressed, and they are mixed well. The mixed discharge liquid L3 and methanol L1 are supplied to the combustion device 11 through the fuel supply line 103, and are burned in the combustion device 11 to drive the combustion device 11. In this way, methanol L1 contained in the discharge liquid L3 discharged from the combustion device 11 by purging can be burned in the combustion device 11. At this time, the methanol L1 passing through the fuel supply line 103 and the discharge liquid L3 containing the purge liquid L2 passing through the mixing line 109 are mixed in a mixing ratio corresponding to the ratio A2 / A1 of the horizontal cross-sectional area A1 of the fuel storage space 13S and the horizontal cross-sectional area A2 of the liquid storage space 15S at the same height in the vertical direction Dv. Since the horizontal cross-sectional area A1 of the fuel storage space 13S at the same height in the vertical direction Dv is larger than the horizontal cross-sectional area A2 of the liquid storage space 15S, more methanol L1 is supplied to the combustion device 11 via the fuel supply line 103 than the discharge liquid L3 containing the purge liquid L2 passing through the mixing line 109. Therefore, even if the purge liquid L2 (clean water) contained in the discharge liquid L3 is not flammable, it is less likely to hinder the combustion of methanol L1 in the combustion device 11. As a result, methanol L1 discharged by purging can be easily reused.

[0047] Furthermore, in the above embodiment, the ratio A2 / A1 of the horizontal cross-sectional area A2 of the liquid storage space 15S to the horizontal cross-sectional area A1 of the fuel storage space 13S at the same height in the vertical direction Dv is set to be less than or equal to the upper limit mixing ratio of the discharge liquid L3 to the methanol L1 that can be burned by the combustion device 11. Therefore, the combustion of methanol L1 can be properly burned in the combustion device 11 while suppressing the inhibition of methanol L1 combustion by the purge liquid L2 contained in the discharge liquid L3.

[0048] Furthermore, in the above embodiment, in the vertical direction Dv, the entire liquid storage space 15S of the recovery tank 15 is located within the range where the fuel storage space 13S of the service tank 13 is located. Therefore, the entire amount of discharged liquid L3 stored in the liquid storage space 15S of the recovery tank 15 can be mixed with methanol L1 stored in the fuel storage space 13S of the service tank 13 at a mixing ratio corresponding to the ratio A2 / A1 of the horizontal cross-sectional area A2 of the liquid storage space 15S and the horizontal cross-sectional area A1 of the fuel storage space 13S, and supplied to the combustion device 11.

[0049] Furthermore, in the above embodiment, the fuel storage space 13S of the service tank 13 extends upward in the vertical direction Dv compared to the liquid storage space 15S of the recovery tank 15. As a result, when the liquid level in the service tank 13 is higher than the liquid level in the recovery tank 15, only methanol L1 is supplied to the combustion device 11. When the liquid level in the service tank 13 reaches the same height as the liquid level in the recovery tank 15, the discharged liquid L3 and methanol L1 are mixed while maintaining the same liquid level in the vertical direction Dv and supplied to the combustion device 11. In this way, the liquid level in the recovery tank 15 is prevented from becoming higher than the liquid level in the service tank 13, and the supply of only discharged liquid L3 to the combustion device 11 is prevented. As a result, the combustion of methanol L1 in the combustion device 11 can always be performed under optimal conditions.

[0050] Furthermore, in the above embodiment, the fuel storage space 13S of the service tank 13 extends lower than the liquid storage space 15S of the recovery tank 15 in the vertical direction Dv. As a result, after methanol L1 from the fuel storage space 13S and discharge liquid L3 from the liquid storage space 15S are mixed and supplied to the combustion device 11, when the liquid level of methanol L1 in the fuel storage space 13S is located lower in the vertical direction Dv than the lower end of the liquid storage space 15S, only methanol L1 is supplied to the combustion device 11. In this way, the entire amount of discharge liquid L3 contained in the liquid storage space 15S can be supplied to the combustion device 11 while being mixed with methanol L1.

[0051] Furthermore, in the above embodiment, the liquid fuel usage equipment 10 is equipped with a check valve 21. This prevents methanol L1 from flowing back from the fuel supply line 103 to the recovery tank 15, for example, when there is no discharge liquid L3 in the liquid storage space 15S, or when the liquid level in the service tank 13 is higher than the liquid level in the recovery tank 15, due to the difference in pressure between the liquid storage space 15S and the fuel supply line 103.

[0052] Furthermore, in the above embodiment, the purge liquid supply unit 14 includes a purge liquid storage tank 141 and a purge liquid supply line 142, so that the purge liquid L2 in the purge liquid storage tank 141 can be supplied to the methanol L1 flow path through the purge liquid supply line 142.

[0053] Furthermore, in the above embodiment, when methanol L1 is used as the liquid fuel, by using fresh water as the purge liquid L2, methanol L1 can be purged effectively while the methanol L1 and fresh water can be well mixed and supplied to the combustion device 11. In addition, by using fresh water as the purge liquid L2, corrosion of the members forming the methanol L1 flow path can be suppressed.

[0054] In the operating method S10 of the liquid fuel-using equipment 10 of the above embodiment, methanol L1 discharged by purging can be easily reused.

[0055] (Modified examples of the embodiment) Figure 10 shows a modified example of a liquid fuel-using equipment according to an embodiment of the present disclosure. In the above embodiment, a check valve 21 is provided in the mixing line 109, but the embodiment is not limited to this. For example, as shown in Figure 10, a power valve 23 may be provided in the middle of the mixing line 109. The power valve 23 sends the discharged liquid L3 from the recovery tank 15 through the mixing line 109 to the fuel supply line 103. As a result, the power valve 23 allows the discharged liquid L3 through the mixing line 109 to flow into the fuel supply line 103 even when the liquid level of methanol L1 in the service tank 13 is above the liquid level of the discharged liquid L3 from the recovery tank 15.

[0056] As a result, by providing the power valve 23, even if the liquid level in the service tank 13 is above the liquid level in the recovery tank 15, the discharged liquid L3 can flow into the fuel supply line 103 through the mixing line 109.

[0057] (Other embodiments) Although embodiments of this disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and may include design changes and the like that do not depart from the gist of this disclosure. In the above embodiment, the fuel storage space 13S of the service tank 13 extends upward in the vertical direction Dv compared to the liquid storage space 15S of the recovery tank 15, but this is not limited to this configuration. The upper end of the fuel storage space 13S may be at the same height as the upper end of the liquid storage space 15S of the recovery tank 15 in the vertical direction Dv.

[0058] In the above embodiment, the fuel storage space 13S of the service tank 13 extends lower than the liquid storage space 15S of the recovery tank 15 in the vertical direction Dv, but the embodiment is not limited to this. The lower end of the fuel storage space 13S may be at the same height as the lower end of the liquid storage space 15S of the recovery tank 15 in the vertical direction Dv.

[0059] In the above embodiment, the fuel storage space 13S and the liquid storage space 15S each have the same cross-sectional shape along the vertical direction Dv, but this is not limited to this. For example, the fuel storage space 13S and the liquid storage space 15S may have their horizontal cross-sectional areas A1 and A2 gradually decreasing or gradually expanding toward the downward side of the vertical direction Dv, respectively. In this case, only one of the horizontal cross-sectional areas A1 and A2 may be gradually decreased, or only one of the horizontal cross-sectional areas A1 and A2 may be gradually expanded. Furthermore, the service tank 13 and the recovery tank 15 are not limited to cylindrical or rectangular shapes, but may also have spherical or other irregular shapes, for example. Here, when the horizontal cross-sectional areas A1 and A2 are gradually reduced or gradually increased as described above, or when the service tank 13 or recovery tank 15 is made spherical or other irregularly shaped, the horizontal cross-sectional area A1 of the fuel storage space 13S is formed to be larger than the horizontal cross-sectional area A2 of the liquid storage space 15S at the same height in the vertical direction Dv, similar to the embodiment described above. The ratio A2 / A1 of the horizontal cross-sectional area A1 of the fuel storage space 13S to the horizontal cross-sectional area A2 of the liquid storage space 15S at the same height in the vertical direction Dv is set to be within a predetermined range, for example, less than or equal to the upper limit mixing ratio of discharge liquid L3 to methanol L1 that can be burned by the combustion device 11.

[0060] In the above embodiment, methanol L1 was used as an example of the liquid fuel, but it is not limited to this. The liquid fuel may also be ethanol, butane, propane, hydrogen, ammonia, etc.

[0061] In the above embodiment, fresh water was used as an example of the purge liquid L2, but it is not limited to this. The purge liquid L2 can be any liquid that is soluble in liquid fuel, such as heavy oil, light oil, seawater, lubricating oil, glycerin, etc.

[0062] <Note> The liquid fuel-using equipment 10, the floating body 1, and the operating method of the liquid fuel-using equipment 10 described in each embodiment can be understood, for example, as follows.

[0063] (1) The liquid fuel usage equipment 10 according to the first embodiment includes a fuel tank 13 having a fuel storage space 13S capable of storing liquid fuel L1, a combustion device 11 driven by the liquid fuel L1, a fuel supply line 103 that supplies the liquid fuel L1 in the fuel tank 13 to the combustion device 11, a purge liquid supply unit 14 capable of supplying a purge liquid L2 soluble in the liquid fuel L1 to the flow path of the liquid fuel L1, a recovery line 107 that recovers the discharge liquid L3 pushed out from the flow path of the liquid fuel L1 by the supply of the purge liquid L2 by the purge liquid supply unit 14, a recovery tank 15 having a liquid storage space 15S capable of storing the discharge liquid L3 recovered through the recovery line 107, and a mixing line 109 that mixes the discharge liquid L3 in the recovery tank 15 with the liquid fuel L1 supplied to the combustion device 11 through the fuel supply line 103. The fuel storage space 13S has a horizontal cross-sectional area A1 at the same height in the vertical direction Dv that is larger than the horizontal cross-sectional area A2 of the liquid storage space 15S. Examples of liquid fuels L1 include methanol, ethanol, butane, propane, hydrogen, and ammonia. Examples of purge fluid L2 include fresh water, heavy oil, light oil, seawater, lubricating oil, and glycerin.

[0064] With this configuration, the discharged liquid L3 stored in the recovery tank 15 can be mixed with the liquid fuel L1 supplied to the combustion device 11 through the mixing line 109. Furthermore, the discharged liquid L3 and the liquid fuel L1 can be mixed at a mixing ratio corresponding to the ratio A2 / A1 of the horizontal cross-sectional area A1 of the fuel storage space 13S and the horizontal cross-sectional area A2 of the liquid storage space 15S. As a result, the liquid fuel L1 discharged by purging can be easily reused without complex equipment configurations or control systems.

[0065] (2) The liquid fuel-using equipment 10 according to the second embodiment is the liquid fuel-using equipment 10 of (1), wherein the ratio A2 / A1 of the horizontal cross-sectional area A2 of the liquid storage space 15S to the horizontal cross-sectional area A1 of the fuel storage space 13S at the same height in the vertical direction Dv is set to be less than or equal to the upper limit mixing ratio of the discharge liquid L3 to the liquid fuel L1 that can be burned by the combustion device 11.

[0066] As a result, the ratio A2 / A1 of the horizontal cross-sectional area A2 of the liquid storage space 15S to the horizontal cross-sectional area A1 of the fuel storage space 13S at the same height in the vertical direction Dv is set to be less than or equal to the upper limit mixing ratio of discharge liquid L3 to liquid fuel L1 that can be burned by the combustion device 11. Therefore, the combustion device 11 can burn the liquid fuel L1 well while suppressing the obstruction of the combustion of the liquid fuel L1 by the purge liquid L2 contained in the discharge liquid L3.

[0067] (3) The liquid fuel-using equipment 10 according to the third embodiment is the liquid fuel-using equipment 10 of (1) or (2), wherein in the vertical direction Dv, the entire liquid storage space 15S is located within the range in which the fuel storage space 13S is located.

[0068] With this configuration, the entire amount of discharge liquid L3 stored in the liquid storage space 15S of the recovery tank 15 can be mixed with the liquid fuel L1 stored in the fuel storage space 13S of the fuel tank 13 at a mixing ratio corresponding to the ratio A2 / A1 of the horizontal cross-sectional area A2 of the liquid storage space 15S and the horizontal cross-sectional area A1 of the fuel storage space 13S, and supplied to the combustion device 11.

[0069] (4) The liquid fuel usage equipment 10 according to the fourth embodiment is the liquid fuel usage equipment 10 of (3), wherein the fuel storage space 13S of the fuel tank 13 extends upward in the vertical direction Dv than the liquid storage space 15S of the recovery tank 15.

[0070] With this configuration, when the liquid level in the fuel tank 13 is higher than the liquid level in the recovery tank 15, only the liquid fuel L1 is supplied to the combustion device 11. When the liquid level in the fuel tank 13 reaches the same height as the liquid level in the recovery tank 15, the discharged liquid L3 and the liquid fuel L1 are mixed while maintaining the same liquid level in the vertical direction Dv and supplied to the combustion device 11. In this way, the liquid level in the recovery tank 15 is prevented from becoming higher than the liquid level in the fuel tank 13, and the supply of only the discharged liquid L3 to the combustion device 11 is prevented. As a result, the combustion of the liquid fuel L1 in the combustion device 11 can always be performed under optimal conditions.

[0071] (5) The liquid fuel usage equipment 10 according to the fifth embodiment is the liquid fuel usage equipment 10 of (3) or (4), wherein the fuel storage space 13S of the fuel tank 13 extends downward in the vertical direction Dv than the liquid storage space 15S of the recovery tank 15.

[0072] With this configuration, the liquid fuel L1 from the fuel storage space 13S and the discharge liquid L3 from the liquid storage space 15S are mixed and supplied to the combustion device 11. When the liquid level of the liquid fuel L1 in the fuel storage space 13S is located below the lower end of the liquid storage space 15S in a vertical direction Dv, only the liquid fuel L1 is supplied to the combustion device 11. In this way, the entire amount of discharge liquid L3 contained in the liquid storage space 15S can be supplied to the combustion device 11 while being mixed with the liquid fuel L1.

[0073] (6) The liquid fuel usage equipment 10 according to the sixth embodiment is any one of the liquid fuel usage equipment 10 from (1) to (5), and further comprises a check valve 21 provided in the mixing line 109 to suppress the backflow of the liquid fuel L1 from the fuel supply line 103 side to the recovery tank 15 side.

[0074] This prevents backflow of liquid fuel L1 from the fuel supply line 103 to the recovery tank 15, for example, when there is no discharged liquid L3 in the liquid storage space 15S, or when the liquid level in the fuel tank 13 is higher than the liquid level in the recovery tank 15, due to the difference in pressure between the liquid storage space 15S and the fuel supply line 103.

[0075] (7) The liquid fuel usage equipment 10 according to the seventh embodiment is any one of the liquid fuel usage equipment 10 of (1) to (5), further comprising a power valve 23 provided in the mixing line 109 that allows the discharge liquid L3 through the mixing line 109 to flow into the fuel supply line 103 when the liquid level in the fuel tank 13 is at or above the liquid level in the recovery tank 15.

[0076] This allows the discharged liquid L3, which has passed through the mixing line 109, to flow into the fuel supply line 103 even if the liquid level in the fuel tank 13 is higher than or equal to the liquid level in the recovery tank 15.

[0077] (8) The liquid fuel equipment 10 according to the eighth embodiment is any one of the liquid fuel equipment 10 from (1) to (7), wherein the purge liquid supply unit 14 comprises a purge liquid storage tank 141 for storing the purge liquid L2 and a purge liquid supply line 142 for supplying the purge liquid L2 in the purge liquid storage tank 141 to the flow path of the liquid fuel L1.

[0078] This allows the purge liquid L2 in the purge liquid storage tank 141 to be supplied to the liquid fuel L1 flow path through the purge liquid supply line 142.

[0079] (9) The liquid fuel-using equipment 10 according to the ninth embodiment is any one of the liquid fuel-using equipment 10 from (1) to (8), wherein the liquid fuel L1 is methanol and the purging liquid L2 is clean water.

[0080] This allows for effective purging of the liquid fuel L1 while properly mixing methanol and fresh water and supplying it to the combustion device 11. Furthermore, using fresh water as the purging liquid L2 suppresses corrosion of the components forming the flow path for the liquid fuel L1.

[0081] (10) The floating body 1 according to the tenth embodiment comprises a floating body body 2 and one of the liquid fuel usage equipment 10 from (1) to (9).

[0082] This makes it possible to provide a floating body 1 equipped with a liquid fuel usage facility 10 that can easily reuse the liquid fuel L1 discharged by purging.

[0083] (11) An operating method for a liquid fuel-using equipment 10 according to the 11th embodiment is an operating method for a liquid fuel-using equipment 10 according to any one of (1) to (9), comprising: step S11 of supplying the liquid fuel L1 in the fuel tank 13 to the combustion device 11 through the fuel supply line 103 and driving the combustion device 11; step S12 of stopping the driving of the combustion device 11 and supplying the purge liquid L2 from the purge liquid supply unit 14 to the flow path of the liquid fuel L1; step S13 of recovering the discharge liquid L3 pushed out by the purge liquid L2 supplied to the flow path of the liquid fuel L1 to the recovery tank 15 through the recovery line 107; and step S14 of mixing the discharge liquid L3 stored in the recovery tank 15 with the liquid fuel L1 flowing in the fuel supply line 103 and supplying it to the combustion device 11 and driving the combustion device 11.

[0084] According to the operating method of this liquid fuel-using equipment 10, the liquid fuel L1 discharged by purging can be easily reused. [Explanation of symbols]

[0085] 1. Floating body 2. Floating body 10 Equipment using liquid fuel 11 Combustion device 13. Service tank (fuel tank) 13S Fuel Compartment 14. Purge liquid supply unit 15 Recovery Tanks 15S Liquid containment space 21 Check valve 23 Power valve 103 Fuel supply line 107 Recovery Line 109 Mixing Line 141 Purge liquid storage tank 142 Purge fluid supply line L1 Methanol (liquid fuel) L2 Purge fluid (clean water)

Claims

1. A fuel tank having a fuel storage space capable of storing liquid fuel, A combustion device driven by the aforementioned liquid fuel, A fuel supply line that supplies the liquid fuel in the fuel tank to the combustion device, A purge liquid supply unit capable of supplying a purge liquid soluble in the liquid fuel to the liquid fuel flow path, A recovery line for recovering the discharge liquid pushed out of the liquid fuel passage by the supply of the purge liquid by the purge liquid supply unit, A recovery tank having a liquid storage space capable of storing the discharged liquid recovered through the recovery line, A mixing line for mixing the discharged liquid in the recovery tank with the liquid fuel supplied to the combustion device through the fuel supply line, Equipped with, The horizontal cross-sectional area of ​​the fuel storage space at the same vertical height is larger than the horizontal cross-sectional area of ​​the liquid storage space. Equipment using liquid fuel.

2. The ratio of the horizontal cross-sectional area of ​​the liquid storage space to the horizontal cross-sectional area of ​​the fuel storage space at the same vertical height is set to be less than or equal to the upper limit mixing ratio of the discharge liquid to the liquid fuel that can be burned by the combustion device. Liquid fuel usage equipment according to claim 1.

3. In the vertical direction, the entire liquid storage space is located within the range in which the fuel storage space is situated. Liquid fuel usage equipment according to claim 1 or 2.

4. The fuel storage space of the fuel tank extends upward in the vertical direction compared to the liquid storage space of the recovery tank. Liquid fuel usage equipment according to claim 3.

5. The fuel storage space of the fuel tank extends downward in the vertical direction compared to the liquid storage space of the recovery tank. Liquid fuel usage equipment according to claim 3.

6. The mixing line is further provided with a check valve that prevents the backflow of the liquid fuel from the fuel supply line side to the recovery tank side. Liquid fuel usage equipment according to claim 1 or 2.

7. The mixing line further includes a power valve that allows the discharged liquid, which has passed through the mixing line, to flow into the fuel supply line when the liquid level in the fuel tank is equal to or higher than the liquid level in the recovery tank. Liquid fuel usage equipment according to claim 1 or 2.

8. The aforementioned purge liquid supply unit is, A purge liquid storage tank for storing the aforementioned purge liquid, A purge liquid supply line that supplies the purge liquid in the purge liquid storage tank to the liquid fuel flow path, It is equipped with Liquid fuel usage equipment according to claim 1 or 2.

9. The aforementioned liquid fuel is methanol, The purging fluid is clean water. Liquid fuel usage equipment according to claim 1 or 2.

10. The floating body and A liquid fuel usage device according to claim 1 or 2, comprising A floating object.

11. A method for operating a liquid fuel-using facility according to claim 1 or 2, The process of supplying the liquid fuel in the fuel tank to the combustion device through the fuel supply line and driving the combustion device, The steps include stopping the operation of the combustion device and supplying the purge liquid from the purge liquid supply unit to the liquid fuel flow path, A step of recovering the discharged liquid, which is pushed out by the purge liquid supplied to the liquid fuel flow path, into the recovery tank through the recovery line, The process includes mixing the discharged liquid stored in the recovery tank with the liquid fuel flowing through the fuel supply line and supplying it to the combustion device to drive the combustion device. Operating procedures for equipment using liquid fuels.

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