Power generation system

Abstract

This prevents the accumulation of flammable gas in the fuel cell housing that contains the fuel cell. [Solution] The power generation system comprises a fuel cell 51, a fuel gas pipe 46, a pipe housing 80, and a third ventilation section 81. The fuel cell 51 supplies power to the ship's electrical equipment. The fuel gas pipe 46 carries the fuel gas supplied to the fuel cell 51. The pipe housing 80 houses only a portion of the fuel gas pipe 46. The third ventilation section 81 ventilates the inside of the pipe housing 80.

Description

Technical Field

[0001] The present invention relates to a power generation system.

Background Art

[0002] The traffic route formation structure of a liquefied gas fuel ship described in Patent Document 1 includes a vehicle loading area and a fuel supply station. The fuel supply station houses a bunker manifold connected to a fuel tank for storing liquefied gas fuel. The valve of the bunker manifold is a gas generation source where fuel gas evaporated from the liquefied gas fuel may leak into the atmosphere. Therefore, the fuel supply station is a gas generation chamber in which the gas generation source is housed.

[0003] An airlock space and small compartments are provided between the fuel supply station and the vehicle loading area. The airlock space is adjacent to the fuel supply station. The small compartments are adjacent to the airlock space. That is, the airlock space is located between the small compartments and the fuel supply station.

[0004] And the pressure in the airlock space is always maintained at a higher pressure than that of the fuel supply station and the small compartments. Therefore, the diffusion of fuel gas from the fuel supply station, which is the gas generation source, to the vehicle loading area is prevented.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Incidentally, fuel cell ships, which are powered by fuel cells, are known. Fuel cells generate electricity by consuming fuel gas. Fuel gas is a flammable gas. Therefore, in fuel cell ships, it is sometimes required to house the fuel cell in a containment. When a fuel cell is housed in a containment, compared to when the fuel cell is placed in an open space inside the ship, fuel gas that leaks or enters due to force majeure is more likely to accumulate in the containment.

[0007] The present invention has been made in view of the above problems, and its objective is to provide a fuel cell ship that can suppress the accumulation of combustible gas in a fuel cell housing that contains a fuel cell. [Means for solving the problem]

[0008] According to one aspect of the present invention, the power generation system comprises a fuel cell, a fuel gas pipeline, a pipeline housing, and a ventilation unit. The fuel cell supplies power to electrical equipment on board the ship. The fuel gas pipeline carries the fuel gas supplied to the fuel cell. The pipeline housing houses only a portion of the fuel gas pipeline. The ventilation unit ventilates the inside of the pipeline housing. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a fuel cell ship that can suppress the accumulation of fuel gas in the fuel cell housing that contains the fuel cell. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows a schematic configuration of a fuel cell ship according to Embodiment 1 of the present invention. [Figure 2] This is a block diagram showing the fuel cell system and first ventilation unit according to Embodiment 1. [Figure 3] This is a flowchart showing the fuel gas shutoff method according to Embodiment 1. [Figure 4] This is a block diagram showing a fuel cell system, a first ventilation unit, and a first external gas detection unit according to Embodiment 2 of the present invention. [Figure 5]This is a flowchart showing the fuel gas shutoff method according to Embodiment 2. [Figure 6] This is a block diagram showing a fuel cell system, a first ventilation unit, a first external gas detection unit, and a second external gas detection unit according to Embodiment 3 of the present invention. [Figure 7] This is a flowchart showing the fuel gas shutoff method according to Embodiment 3. [Figure 8] This figure shows a part of the internal structure of a fuel cell ship according to Embodiment 4 of the present invention. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference numerals and will not be repeated in the description.

[0012] (Embodiment 1) The fuel cell ship 100 according to Embodiment 1 of the present invention will be described with reference to Figures 1 to 3. First, the fuel cell ship 100 according to Embodiment 1 will be described with reference to Figure 1. Figure 1 is a diagram showing the schematic configuration of the fuel cell ship 100.

[0013] As shown in Figure 1, the fuel cell ship 100 comprises a hull 1, a cabin 3, a fuel cell system 5, a fuel gas storage unit 6, a battery system 7, a propulsion system 9, a number of auxiliary machines 11, an exhaust fan 13, a duct 15, and a control device 17. The cabin 3 is located on the upper surface of the hull 1.

[0014] The control device 17 controls the fuel cell system 5, the fuel gas storage unit 6, the battery system 7, the propulsion system 9, the multiple auxiliary devices 11, and the exhaust fan 13. The control device 17 is composed of, for example, one or more computers. The computers are, for example, ECUs (Electronic Control Units). The control device 17 is powered by the battery.

[0015] Specifically, the control device 17 includes a control unit 171 and a storage unit 173. The control unit 171 includes a processor such as a CPU (Central Processing Unit). The storage unit 173 includes a storage device and stores data and computer programs. Specifically, the storage unit 173 includes a main storage device such as a semiconductor memory, and an auxiliary storage device such as a semiconductor memory, a solid state drive, and / or a hard disk drive. The storage unit 173 may include a removable medium. The storage unit 173 corresponds to an example of a non-transitory computer-readable storage medium.

[0016] By executing the computer program stored in the storage device of the storage unit 173, the processor of the control unit 171 controls the fuel cell system 5, the fuel gas storage unit 6, the battery system 7, the propulsion device 9, the plurality of auxiliary machines 11, and the exhaust fan 13.

[0017] The fuel cell system 5 functions as a main power source. The fuel cell system 5 consumes fuel gas to generate electric power (specifically, direct current power). Then, the fuel cell system 5 supplies electric power to the propulsion device 9, the auxiliary machines 11, and the exhaust fan 13. Also, the fuel cell system 5 supplies electric power for charging the battery system 7 to the battery system 7.

[0018] The fuel gas storage unit 6 stores fuel gas. Then, the fuel gas storage unit 6 supplies the fuel gas to the fuel cell system 5. The fuel gas is flammable. The fuel gas is an example of the "flammable gas" of the present invention. Typically, the fuel gas is hydrogen gas.

[0019] The battery system 7 functions as an auxiliary power source. The battery system 7 stores electrical power (specifically, DC power) and supplies it to the propulsion device 9, auxiliary equipment 11, and exhaust fan 13 in order to compensate for a shortage in the power supplied by the fuel cell system 5. The battery system 7 may supply power to the control device 17. The battery system 7 has a battery. The battery is, for example, a lithium secondary battery, nickel-cadmium battery, or nickel-metal hydride battery.

[0020] The propulsion device 9 is driven by electric power and generates propulsion force for the hull 1. The propulsion device 9 includes a power conversion device 91, a propulsion motor 93, and a propeller 95. The power conversion device 91 converts the power supplied from the fuel cell system 5 into power according to the specifications of the propulsion motor 93. For example, the power conversion device 91 converts DC power into AC power. In this case, for example, the power conversion device 91 has an inverter. The propulsion motor 93 is driven by the power (e.g., AC power) supplied from the power conversion device 91. When the propulsion motor 93 is driven, the rotational force of the propulsion motor 93 is transmitted to the propeller 95. As a result, the propeller 95 rotates and generates propulsion force for the hull 1.

[0021] The exhaust fan 13 is driven by electric power and exhausts air from the inside to the outside of the hull 1 through the duct 15.

[0022] ' The auxiliary equipment 11 is equipment driven by electric power and is different from the propulsion device 9 and the control device 17. The auxiliary equipment 11 is, for example, a compressor, solenoid valve, pump, lighting equipment, or air conditioning equipment. However, the type of the auxiliary equipment 11 is not particularly limited. The exhaust fan 13 is also an example of the auxiliary equipment 11.

[0023] Next, the details of the fuel cell system 5 will be described with reference to Figure 2. Figure 2 is a block diagram of the fuel cell system 5. As shown in Figure 2, the fuel cell system 5 includes a fuel cell 51, an oxidizer gas flow rate adjustment unit 53, a shut-off unit 57, an off-gas circulation unit 59, a gas-liquid separation unit 60, a discharge unit 61, a cooling medium circulation unit 67, a cooling medium storage unit 69, and a heat exchange unit 71. The fuel cell system 5 also includes an oxidizer gas piping 55, a first discharge piping 56, a fuel gas piping 63, an off-gas circulation piping 65, a second discharge piping 66, a third discharge piping 68, a first cooling medium piping 73, and a second cooling medium piping 75. Furthermore, a manifold for circulating fuel gas, oxidizer gas, and the first cooling medium is formed inside the fuel cell 51. The oxidizer gas flow rate adjustment unit 53, the shut-off unit 57, the off-gas circulation unit 59, and the discharge unit 61 are examples of auxiliary equipment 11. Furthermore, the control unit 171 controls the oxidizer gas flow rate adjustment unit 53, the shut-off unit 57, the off-gas circulation unit 59, and the discharge unit 61.

[0024] The fuel cell 51 generates electricity (specifically DC electricity) through an electrochemical reaction between a fuel gas and an oxidizer gas. Typically, the oxidizer gas is air, and the oxidizer is oxygen.

[0025] The fuel cell 51 supplies power to the propulsion system 9, exhaust fan 13, and auxiliary equipment 11. Alternatively, the fuel cell 51 may indirectly supply power to the propulsion system 9, exhaust fan 13, and auxiliary equipment 11 via a circuit such as a DC / DC converter.

[0026] Specifically, the fuel cell 51 is a fuel cell stack composed of multiple stacked cells. For example, each cell of the fuel cell 51 has a solid polymer electrolyte membrane, an anode electrode, a cathode electrode, and a pair of separators. The anode electrode and the cathode electrode are separated by the solid polymer electrolyte membrane. The anode electrode is the negative electrode (fuel electrode). The anode electrode includes an anode catalyst layer and a gas diffusion layer. The cathode electrode is the positive electrode (air electrode). The cathode electrode includes a cathode catalyst layer and a gas diffusion layer. The anode electrode, the solid polymer electrolyte membrane, and the cathode electrode constitute a membrane electrode assembly (MEA). The pair of separators sandwich the membrane electrode assembly. Each separator has multiple grooves. Each groove in one separator forms a flow path for the fuel gas. Each groove in the other separator forms a flow path for the oxidizer gas.

[0027] The oxidant gas flow rate adjustment unit 53 supplies oxidant gas to the cathode electrode of the fuel cell 51. Specifically, the oxidant gas flow rate adjustment unit 53 adjusts the flow rate of oxidant gas supplied to the fuel cell 51. Typically, the oxidant gas flow rate adjustment unit 53 is an air compressor that compresses the oxidant gas and supplies the compressed oxidant gas to the fuel cell 51.

[0028] The oxidant gas piping 55 connects the oxidant gas flow rate adjustment unit 53 to the fuel cell 51 and guides the compressed oxidant gas supplied from the oxidant gas flow rate adjustment unit 53 to the cathode electrode of the fuel cell 51. In other words, the oxidant passes through the oxidant gas piping 55. The first discharge piping 56 is connected to the cathode-side discharge manifold installed inside the fuel cell 51 and guides the oxidant off-gas and water discharged from the fuel cell 51 to the atmosphere. The oxidant off-gas represents the exhaust from the cathode. In other words, the oxidant off-gas is the cathode off-gas. The cathode represents the cathode electrode of the fuel cell 51.

[0029] The fuel cell system 5 may further include an oxidant gas diversion section (not shown) and a bypass pipe (not shown). The oxidant gas diversion section is located in the oxidant gas piping 55 downstream of the oxidant gas flow rate adjustment section 53 and upstream of the fuel cell 51. One end of the bypass pipe is connected to the oxidant gas diversion section, and the other end of the bypass pipe is connected to the first discharge pipe 56.

[0030] The oxidant gas diversion section adjusts the amount of oxidant gas supplied from the oxidant gas flow rate adjustment section 53 to be supplied to the oxidant gas piping 55 and to the bypass piping. Typically, the oxidant gas diversion section is a diversion valve. The bypass piping then guides the oxidant gas supplied from the oxidant gas flow rate adjustment section 53 via the oxidant gas diversion section to the first discharge piping 56 without supplying it to the fuel cell 51.

[0031] The shut-off unit 57 is located in the fuel gas piping 63 and opens or closes the flow path of the fuel gas piping 63. Specifically, the shut-off unit 57 switches the supply of fuel gas to the fuel cell 51 on and off. Therefore, the shut-off unit 57 can shut off the fuel gas supplied to the fuel cell 51. Typically, the shut-off unit 57 is a shut-off valve. The fuel gas piping 63 is connected to the fuel gas storage unit 6 (Figure 1).

[0032] The fuel gas pipeline 63 supplies fuel gas from the fuel gas storage unit 6 to the anode of the fuel cell 51. In other words, the fuel gas passes through the fuel gas pipeline 63.

[0033] The gas-liquid separation unit 60 separates water contained in the fuel off-gas discharged from the fuel cell 51 and discharges the water into the second discharge pipe 66. In addition, the gas-liquid separation unit 60 discharges the excess fuel gas, which is the fuel off-gas after the water has been separated, into the off-gas circulation pipe 65. Typically, the gas-liquid separation unit 60 is a gas-liquid separator. The fuel off-gas represents the exhaust from the anode. In other words, the fuel off-gas is the anode off-gas. The anode represents the anode electrode of the fuel cell 51.

[0034] The off-gas circulation unit 59 is located in the off-gas circulation piping 65. The off-gas circulation unit 59 discharges excess fuel gas discharged from the gas-liquid separation unit 60 to the fuel gas piping 63. The fuel gas piping 63 then supplies the excess fuel gas to the fuel cell 51. Typically, the off-gas circulation unit 59 is a pump. However, for example, the off-gas circulation unit 59 may be an ejector.

[0035] The discharge section 61 is located at the boundary between the second discharge pipe 66 and the third discharge pipe 68. The discharge section 61 discharges the water separated by the gas-liquid separation section 60 into the third discharge pipe 68. In addition, the discharge section 61 discharges a portion of the fuel off-gas discharged from the fuel cell 51, i.e., the remaining gas and water that was not supplied to the off-gas circulation pipe 65, into the third discharge pipe 68. Typically, the discharge section 61 is a purge valve.

[0036] The third discharge pipe 68 connects the discharge section 61 and the first discharge pipe 56, guiding the water and fuel off-gas discharged from the discharge section 61 to the first discharge pipe 56. The first discharge pipe 56 then guides the water and fuel off-gas to the atmosphere.

[0037] The cooling medium circulation unit 67 circulates the first cooling medium in the first cooling medium piping 73. Typically, the cooling medium circulation unit 67 is a pump. The first cooling medium is, for example, water. Alternatively, the first cooling medium may be, for example, antifreeze. Antifreeze is, for example, a liquid obtained by mixing pure water and ethylene glycol in a predetermined ratio. The first cooling medium circulates in the first cooling medium piping 73. The first cooling medium piping 73 is connected to the fuel cell 51 and supplies the first cooling medium to the fuel cell 51. Therefore, the fuel cell 51 is cooled by the first cooling medium. The first cooling medium piping 73 corresponds to an example of the "cooling medium piping" of the present invention. The first cooling medium corresponds to an example of the "cooling medium" of the present invention.

[0038] The cooling medium storage section 69 stores the first cooling medium. The cooling medium storage section 69 is, for example, a tank. When the temperature of the first cooling medium changes, the first cooling medium expands or contracts. Therefore, the cooling medium storage section 69 suppresses the change in internal pressure of the first cooling medium piping 73 caused by the expansion or contraction of the first cooling medium. As a result, the first cooling medium can be smoothly supplied to the fuel cell 51 by the first cooling medium piping 73. The upper part of the cooling medium storage section 69 may be open or closed.

[0039] The first cooling medium piping 73 is connected to the cooling medium storage unit 69. The first cooling medium piping 73 supplies the first cooling medium from the cooling medium storage unit 69 to the fuel cell 51. The first cooling medium piping 73 then discharges the first cooling medium, which has cooled the fuel cell 51, back towards the cooling medium storage unit 69.

[0040] Specifically, the first cooling medium piping 73 includes a cooling medium supply pipe 731 and a cooling medium discharge pipe 732. The cooling medium supply pipe 731 extends from the cooling medium storage section 69 to the fuel cell 51. That is, one end of the cooling medium supply pipe 731 is connected to the cooling medium storage section 69, and the other end of the cooling medium supply pipe 731 is connected to the fuel cell 51. The cooling medium circulation section 67 is located in the cooling medium supply pipe 731. The cooling medium circulation section 67 supplies the first cooling medium stored in the cooling medium storage section 69 to the fuel cell 51 via the cooling medium supply pipe 731. The first cooling medium then absorbs heat from the fuel cell 51 as it passes through it. In other words, the first cooling medium cools the fuel cell 51.

[0041] The first cooling medium, having absorbed heat, is then discharged into the cooling medium discharge pipe 732. The cooling medium discharge pipe 732 extends from the fuel cell 51 to the cooling medium storage section 69. In other words, one end of the cooling medium discharge pipe 732 is connected to the fuel cell 51, and the other end of the cooling medium discharge pipe 732 is connected to the cooling medium storage section 69. The cooling medium circulation section 67 guides the first cooling medium through the cooling medium discharge pipe 732 to the cooling medium storage section 69.

[0042] The second cooling medium flows through the second cooling medium piping 75. The second cooling medium is, for example, water (e.g., seawater, river water, or lake water).

[0043] The heat exchange unit 71 is located in the first cooling medium piping 73 and the second cooling medium piping 75. Specifically, the heat exchange unit 71 is located in the cooling medium discharge pipe 732. The heat exchange unit 71 cools the first cooling medium, which has absorbed heat from the fuel cell 51, by performing heat exchange between the first cooling medium and the second cooling medium. The heat exchange unit 71 is typically a heat exchanger.

[0044] Furthermore, as shown in Figure 2, the fuel cell ship 100 further includes a fuel cell housing 19, a first ventilation unit 21, a first internal gas detection unit 23, and a first fire detection unit 25.

[0045] The fuel cell housing 19 houses the fuel cell 51. In other words, the fuel cell housing 19 has a space for housing the fuel cell 51. In the example in Figure 2, in addition to the fuel cell 51, the fuel cell housing 19 houses a first internal gas detection unit 23, a first fire detection unit 25, a shutoff unit 57, an off-gas circulation unit 59, a gas-liquid separation unit 60, a discharge unit 61, part of the oxidizer gas piping 55, part of the first discharge piping 56, part of the fuel gas piping 63, off-gas circulation piping 65, a second discharge piping 66, a third discharge piping 68, and part of the first cooling medium piping 73.

[0046] On the other hand, the oxidizer gas flow rate adjustment unit 53, the cooling medium storage unit 69, and the heat exchange unit 71 are located outside the fuel cell housing 19. However, at least one of the oxidizer gas flow rate adjustment unit 53, the cooling medium storage unit 69, and the heat exchange unit 71 may be housed within the fuel cell housing 19.

[0047] The material of the fuel cell housing 19 is, for example, fiber-reinforced plastic (FRP). Fiber-reinforced plastics include, for example, glass fiber reinforced plastic, glass fiber mat reinforced thermoplastic, carbon fiber reinforced plastic, boron fiber reinforced plastic, aramid fiber reinforced plastic, Kevlar fiber reinforced plastic, Dyneema fiber reinforced plastic, or Zylon reinforced plastic. However, as long as the airtightness of the fuel cell housing 19 can be ensured, the material of the fuel cell housing 19 is not particularly limited, and for example, a steel plate may also be used.

[0048] The fuel cell housing 19 has a hollow shape. For example, the fuel cell housing 19 has a hollow, substantially rectangular parallelepiped shape. In this case, the fuel cell housing 19 has, for example, a top wall 19a, a bottom wall 19b, a front wall (not shown), a rear wall (not shown), side walls 19c, and side walls 19d. However, the top, bottom, front, rear, and sides of the fuel cell housing 19 can be arbitrarily determined. Furthermore, the shape of the fuel cell housing 19 is not particularly limited as long as it has space to accommodate the fuel cell 51. The fuel cell housing 19 can also be considered as a container, chamber, or box that houses the fuel cell 51. The fuel cell housing 19 is, for example, located below the deck 1a (Figure 1) of the hull 1. For example, the fuel cell housing 19 may be located on the deck 1a.

[0049] The first ventilation unit 21 ventilates the inside of the fuel cell housing 19. Therefore, according to Embodiment 1, even if fuel gas (combustible gas) leaks inside the fuel cell housing 19 due to force majeure, the fuel gas can be discharged to the outside of the fuel cell housing 19. Also, even if combustible gas (fuel gas or other combustible gas) enters the fuel cell housing 19 due to force majeure, the combustible gas can be discharged to the outside of the fuel cell housing 19.

[0050] Therefore, according to Embodiment 1, the accumulation of combustible gas in the fuel cell housing 19 containing the fuel cell 51 can be suppressed. In this specification, combustible gas refers to fuel gas or other combustible gases. "Fuel gas" is typically hydrogen gas, and "other combustible gases" are, for example, methane, ethane, propane, or carbon monoxide.

[0051] Specifically, the first ventilation unit 21 has a first ventilation opening 211 and a second ventilation opening 213.

[0052] The first ventilation opening 211 is located in the fuel cell housing 19 and connects the inside and outside of the fuel cell housing 19. In Embodiment 1, the first ventilation opening 211 is located at the bottom of the fuel cell housing 19. In the example shown in Figure 2, the first ventilation opening 211 is located at the bottom of the side wall 19d. For example, the first ventilation opening 211 may be located on the bottom wall 19b on the side of the side wall 19d. However, the location of the first ventilation opening 211 is not particularly limited as long as ventilation is possible. The first ventilation opening 211 is, for example, a ventilation opening for supplying air. However, exhaust may also be performed through the first ventilation opening 211.

[0053] The second ventilation opening 213 is located in the fuel cell housing 19 and connects the inside and outside of the fuel cell housing 19. In Embodiment 1, the second ventilation opening 213 is located at the top of the fuel cell housing 19. In the example in Figure 2, the second ventilation opening 213 is located on the top wall 19a on the side of the side wall 19c. For example, the second ventilation opening 213 may be located at the top of the side wall 19c. However, the location of the second ventilation opening 213 is not particularly limited as long as ventilation is possible. The second ventilation opening 213 is, for example, a ventilation opening for exhaust. However, supply air may also be provided through the second ventilation opening 213. The second ventilation opening 213 corresponds to an example of a "ventilation opening".

[0054] One or both of the first ventilation opening 211 and the second ventilation opening 213 may be fitted with one or more filters (not shown). The filters remove, for example, dust or sea salt particles.

[0055] The first internal gas detection unit 23 is located inside the fuel cell housing 19. For example, the first internal gas detection unit 23 is located on the upper inner surface of the fuel cell housing 19. This is because fuel gas is lighter than air and rises. The first internal gas detection unit 23 is an example of the "internal gas detection unit" of the present invention.

[0056] The first internal gas detection unit 23 detects the fuel gas. Typically, the fuel gas is hydrogen gas, so the first internal gas detection unit 23 is, for example, a hydrogen gas sensor. The first internal gas detection unit 23 outputs a signal indicating the fuel gas concentration (hydrogen gas concentration) to the control unit 171.

[0057] When the first internal gas detection unit 23 detects fuel gas, the control unit 171 controls the shut-off unit 57 to shut off the fuel gas supplied to the fuel cell 51. Accordingly, the shut-off unit 57 shuts off the fuel gas in the fuel gas piping 63. As a result, the supply of fuel gas to the fuel cell 51 is stopped. For example, if the first internal gas detection unit 23 detects fuel gas, there is a possibility that fuel gas has leaked inside the fuel cell housing 19 due to force majeure. Therefore, by shutting off the fuel gas in the fuel gas piping 63, further leakage of fuel gas can be prevented.

[0058] Specifically, when the first internal gas detection unit 23 detects a fuel gas at a predetermined concentration TH1 or higher, the control unit 171 controls the shut-off unit 57 to shut off the fuel gas. The predetermined concentration TH1 is determined in advance experimentally and / or empirically.

[0059] The first fire detection unit 25 is located inside the fuel cell housing 19. Specifically, the first fire detection unit 25 is located on the upper inner surface of the fuel cell housing 19. In the example shown in Figure 2, the first fire detection unit 25 is located on the top wall 19a of the fuel cell housing 19.

[0060] The first fire detection unit 25 detects a fire occurring inside the fuel cell housing 19 and outputs a signal to the control unit 171 indicating that a fire has occurred. The first fire detection unit 25 includes, for example, one or more sensors such as a smoke sensor for detecting smoke, a heat sensor for detecting heat, or a flame sensor for detecting flames.

[0061] When the first fire detection unit 25 detects a fire, the control unit 171 controls the shut-off unit 57 to shut off the fuel gas supplied to the fuel cell 51. As a result, the shut-off unit 57 shuts off the fuel gas in the fuel gas piping 63.

[0062] Next, the fuel gas shutoff method according to Embodiment 1 will be described with reference to Figures 2 and 3. Figure 3 is a flowchart of the fuel gas shutoff method. As shown in Figure 3, the fuel gas shutoff method includes steps S1 to S3.

[0063] As shown in Figures 2 and 3, first, in step S1, the control unit 171 determines whether or not the first internal gas detection unit 23 has detected fuel gas.

[0064] If it is determined in step S1 that no fuel gas is detected (No), the process proceeds to step S2. For example, if the first internal gas detection unit 23 detects a fuel gas at a predetermined concentration of less than TH1 (including cases where the first internal gas detection unit 23 does not detect any fuel gas), the process proceeds to step S2.

[0065] On the other hand, if it is determined in step S1 that fuel gas has been detected (Yes), the process proceeds to step S3. For example, if the first internal gas detection unit 23 detects fuel gas at a predetermined concentration TH1 or higher, the process proceeds to step S3.

[0066] Next, in step S2, the control unit 171 determines whether or not the first fire detection unit 25 has detected a fire.

[0067] If it is determined in step S2 that no fire has been detected (No), the process proceeds to step S1.

[0068] On the other hand, if it is determined in step S2 that a fire has been detected (Yes), the process proceeds to step S3.

[0069] Next, in step S3, the control unit 171 controls the shut-off unit 57 to shut off the fuel gas flowing through the fuel gas piping 63. As a result, the shut-off unit 57 shuts off the fuel gas supplied to the fuel cell 51. Then the process ends.

[0070] The order of steps S1 and S2 is not particularly limited and can be any order, and they may be executed in parallel.

[0071] Furthermore, for example, the control unit 171 may perform the following processes. For example, when the fuel gas concentration detected by the first internal gas detection unit 23 reaches "20% LEL", the control unit 171 issues a warning signal. Also, for example, when the fuel gas concentration detected by the first internal gas detection unit 23 reaches "40% LEL", the control unit 171 issues an alarm signal and controls the shut-off unit 57 to shut off the fuel gas supplied to the fuel cell 51.

[0072] (Embodiment 2) A fuel cell vessel 100 according to Embodiment 2 of the present invention will be described with reference to Figures 4 and 5. Embodiment 2 differs from Embodiment 1 mainly in that it performs ventilation by supplying fresh air. The configuration of the fuel cell vessel 100 according to Embodiment 2 is the same as the configuration of the fuel cell vessel 100 shown in Figure 1. The differences between Embodiment 2 and Embodiment 1 will be mainly described below.

[0073] First, with reference to Figure 4, the first ventilation unit 21A according to Embodiment 2 will be described. Figure 4 is a block diagram showing the fuel cell system 5, the first ventilation unit 21A, and the first external gas detection unit 24. As shown in Figure 4, the fuel cell ship 100 is equipped with the first ventilation unit 21A. The first ventilation unit 21A ventilates the inside of the fuel cell housing 19.

[0074] The first ventilation unit 21A includes a first ventilation opening 211, a second ventilation opening 213, a duct 214, and a first air supply unit 215. The duct 214 is connected to the first ventilation opening 211.

[0075] The first air supply unit 215 is, for example, an air supply fan. The control unit 171 controls the first air supply unit 215. The first air supply unit 215 corresponds to an example of the "air supply unit" of the present invention.

[0076] The first air supply unit 215 supplies air from outside the fuel cell housing 19 to the inside of the fuel cell housing 19 through the first ventilation opening 211. Therefore, the inside of the fuel cell housing 19 is ventilated by the supply of air. As a result, the accumulation of combustible gases (fuel gas and other combustible gases) in the fuel cell housing 19 containing the fuel cell 51 can be effectively suppressed. The first air supply unit 215 is preferably a non-explosion-proof air supply fan because it is inexpensive. However, the first air supply unit 215 may also be an explosion-proof air supply fan.

[0077] Specifically, the first air supply unit 215 supplies air, so outside air is supplied to the inside of the fuel cell housing 19 through the first ventilation opening 211. Then, exhaust air is carried out through the second ventilation opening 213. As a result, the inside of the fuel cell housing 19 is ventilated.

[0078] In this case, the second ventilation opening 213 functions as an exhaust vent. Therefore, it is preferable to place the first internal gas detection unit 23 in the second ventilation opening 213. Alternatively, it is preferable to place the first internal gas detection unit 23 upstream of the exhaust (air) flow relative to the second ventilation opening 213 and in the vicinity of the second ventilation opening 213. According to these preferred examples, fuel gas can be effectively detected because fuel gas that leaks or enters due to force majeure will concentrate in the second ventilation opening 213, which functions as an exhaust vent.

[0079] In the example shown in Figure 4, the first air supply unit 215 is located in the duct 214. The first air supply unit 215 supplies air from outside the fuel cell housing 19 to the inside of the fuel cell housing 19 through the duct 214 and the first ventilation opening 211. The location of the first air supply unit 215 is not particularly limited, as long as it is possible to supply air to the fuel cell housing 19 through the first ventilation opening 211. For example, the first air supply unit 215 may be located in the first ventilation opening 211.

[0080] In particular, in Embodiment 2, it is preferable that the fuel cell ship 100 further comprises a first external gas detection unit 24. The first external gas detection unit 24 is located outside the fuel cell housing 19. The first external gas detection unit 24 detects combustible gas (fuel gas or other combustible gas) flowing into the fuel cell housing 19 from the outside. The first external gas detection unit 24 is, for example, a combustible gas sensor. In this specification, the combustible gas sensor may be, for example, a hydrogen gas sensor. The first external gas detection unit 24 outputs a signal indicating the combustible gas concentration to the control unit 171.

[0081] Specifically, the first external gas detection unit 24 is positioned outside the fuel cell housing 19, corresponding to the first air supply unit 215. More specifically, the first external gas detection unit 24 is positioned upstream of the airflow relative to the first air supply unit 215. In the example shown in Figure 4, the first external gas detection unit 24 is positioned outside the first air supply unit 215, near the air inlet 215a of the first air supply unit 215. The first external gas detection unit 24 detects combustible gas flowing from outside the fuel cell housing 19 into the first ventilation opening 211. In other words, the first external gas detection unit 24 detects combustible gas flowing from outside the fuel cell housing 19 toward the first air supply unit 215.

[0082] The control unit 171 stops the first air supply unit 215 when the first external gas detection unit 24 detects a flammable gas. Therefore, according to Embodiment 2, it is possible to suppress the intrusion of flammable gas into the fuel cell housing 19 through the first ventilation opening 211. As a result, unintended interactions between the fuel cell system 5 and the flammable gas can be prevented. In addition, even if the first air supply unit 215 does not have an explosion-proof structure, unintended interactions between the flammable gas and the first air supply unit 215 can be prevented.

[0083] Specifically, when the first external gas detection unit 24 detects a flammable gas at a predetermined concentration TH2 or higher, the control unit 171 stops the first air supply unit 215. The predetermined concentration TH2 is determined in advance experimentally and / or empirically.

[0084] In addition, if the first external gas detection unit 24 detects a flammable gas, the control unit 171 controls the shut-off unit 57 to shut off the fuel gas supplied to the fuel cell 51. Consequently, the shut-off unit 57 shuts off the fuel gas in the fuel gas piping 63. As a result, the supply of fuel gas to the fuel cell 51 is stopped, and the power generation of the fuel cell 51 stops. For example, if the first external gas detection unit 24 detects a flammable gas, it is possible that the flammable gas has flowed into the fuel cell housing 19 through the first ventilation opening 211. Therefore, by shutting off the fuel gas in the fuel gas piping 63 and stopping the fuel cell 51, unintended interaction between the fuel cell system 5 and the flammable gas can be prevented.

[0085] Specifically, when the first external gas detection unit 24 detects a combustible gas at a predetermined concentration of TH2 or higher, the control unit 171 controls the shut-off unit 57 to shut off the fuel gas.

[0086] The first air supply unit 215 may be equipped with one or more filters (not shown). The filters remove, for example, dust or sea salt particles.

[0087] Next, the fuel gas shutoff method according to Embodiment 2 will be described with reference to Figures 4 and 5. Figure 5 is a flowchart of the fuel gas shutoff method. As shown in Figure 5, the fuel gas shutoff method includes steps S11 to S15.

[0088] As shown in Figures 4 and 5, first, in step S11, the control unit 171 determines whether or not the first internal gas detection unit 23 has detected fuel gas. This is the same as in step S1 in Figure 3.

[0089] If it is determined in step S11 that fuel gas has been detected (Yes), the process proceeds to step S15.

[0090] On the other hand, if it is determined in step S11 that no fuel gas is detected (No), the process proceeds to step S12.

[0091] Next, in step S12, the control unit 171 determines whether or not the first external gas detection unit 24 has detected a flammable gas.

[0092] If it is determined in step S12 that a flammable gas has been detected (Yes), the process proceeds to step S14. For example, if the first external gas detection unit 24 detects a flammable gas at a predetermined concentration TH2 or higher, the process proceeds to step S14.

[0093] On the other hand, if it is determined in step S12 that no combustible gas is detected (No), the process proceeds to step S13. For example, if the first external gas detection unit 24 detects a combustible gas at a predetermined concentration of less than TH2 (including cases where the first external gas detection unit 24 does not detect any combustible gas), the process proceeds to step S13.

[0094] Next, in step S13, the control unit 171 determines whether or not the first fire detection unit 25 has detected a fire.

[0095] If it is determined in step S13 that no fire has been detected (No), the process proceeds to step S11.

[0096] On the other hand, if it is determined in step S13 that a fire has been detected (Yes), the process proceeds to step S14.

[0097] Next, in step S14, the control unit 171 controls the first air supply unit 215 to stop it. As a result, the first air supply unit 215 stops supplying air to the fuel cell housing 19. In other words, if it is determined in step S12 that a flammable gas has been detected, or if it is determined in step S13 that a fire has been detected, the first air supply unit 215 will stop.

[0098] Next, in step S15, the control unit 171 controls the shut-off unit 57 to shut off the fuel gas flowing through the fuel gas piping 63. As a result, the shut-off unit 57 shuts off the fuel gas supplied to the fuel cell 51. In other words, if it is determined in step S11 that fuel gas has been detected, if it is determined in step S12 that flammable gas has been detected, or if it is determined in step S13 that a fire has been detected, the shut-off unit 57 shuts off the fuel gas supplied to the fuel cell 51. Then the process ends.

[0099] The order of steps S11, S12, and S13 is not particularly limited and can be any order, and they may be executed in parallel. In this case, for example, if a positive result (Yes) is obtained in any of steps S11 to S13, the process proceeds to steps S14 and S15. The order of steps S14 and S15 is also not particularly limited and can be any order, and they may be executed in parallel. Therefore, for example, if a positive result (Yes) is obtained in any of steps S11 to S13, the process in step S14 and the process in step S15 may be executed simultaneously, or one of the processes may be executed slightly earlier by a split second.

[0100] Furthermore, for example, the control unit 171 may perform the following processes. For example, if the concentration of fuel gas detected by the first internal gas detection unit 23 reaches "20% LEL", or if the concentration of combustible gas detected by the first external gas detection unit 24 reaches "20% LEL", the control unit 171 will issue a warning signal. Then, for example, if the concentration of fuel gas detected by the first internal gas detection unit 23 reaches "40% LEL", or if the concentration of combustible gas detected by the first external gas detection unit 24 reaches "40% LEL", the control unit 171 will issue an alarm signal, control the shut-off unit 57 to shut off the fuel gas supplied to the fuel cell 51, and stop the first air supply unit 215.

[0101] (Embodiment 3) A fuel cell vessel 100 according to Embodiment 3 of the present invention will be described with reference to Figures 6 and 7. Embodiment 3 differs from Embodiment 2 mainly in that it detects fuel gas that may be released from the cooling medium storage section 69. The configuration of the fuel cell vessel 100 according to Embodiment 3 is the same as the configuration of the fuel cell vessel 100 shown in Figure 1. The differences between Embodiment 3 and Embodiment 2 will be mainly described below.

[0102] First, with reference to Figure 6, the second external gas detection unit 27 according to Embodiment 3 will be described. Figure 6 is a block diagram showing the fuel cell system 5, the first ventilation unit 21A, the first external gas detection unit 24, and the second external gas detection unit 27. As shown in Figure 6, the fuel cell ship 100 is equipped with the second external gas detection unit 27.

[0103] The second external gas detection unit 27 is located outside the fuel cell housing 19. The second external gas detection unit 27 detects fuel gas flowing from the inside to the outside of the fuel cell housing 19. Typically, the fuel gas is hydrogen gas, so the second external gas detection unit 27 is, for example, a hydrogen gas sensor. The second external gas detection unit 27 outputs a signal indicating the fuel gas concentration (hydrogen gas concentration) to the control unit 171. The fuel gas corresponds to an example of the "combustible gas" of the present invention.

[0104] In particular, in Embodiment 3, the second external gas detection unit 27 is located outside the fuel cell housing 19, corresponding to the cooling medium storage unit 69. Also in Embodiment 3, the upper part of the cooling medium storage unit 69 is open. That is, the cooling medium storage unit 69 has an upper opening 69a. The second external gas detection unit 27 is located above the second external gas detection unit 27. In other words, the second external gas detection unit 27 is located at a distance from the cooling medium storage unit 69, while facing the upper opening 69a of the cooling medium storage unit 69. In the example in Figure 6, the second external gas detection unit 27 is located near the upper opening 69a of the cooling medium storage unit 69.

[0105] For example, if fuel gas leaks from the fuel cell 51 due to force majeure, the fuel gas may enter the first cooling medium piping 73 (specifically, the cooling medium discharge pipe 732). In this case, the fuel gas may move through the first cooling medium piping 73 (specifically, the cooling medium discharge pipe 732) to the cooling medium storage unit 69 and be released from the first cooling medium WA stored in the cooling medium storage unit 69. As a result, the second external gas detection unit 27 detects the fuel gas released from the first cooling medium WA.

[0106] When the second external gas detection unit 27 detects fuel gas, the control unit 171 controls the shut-off unit 57 to shut off the fuel gas supplied to the fuel cell 51. Accordingly, the shut-off unit 57 shuts off the fuel gas in the fuel gas piping 63. As a result, the supply of fuel gas to the fuel cell 51 is stopped. For example, if the second external gas detection unit 27 detects fuel gas, there is a possibility that fuel gas is leaking from the fuel cell 51 due to force majeure. Therefore, by shutting off the fuel gas in the fuel gas piping 63, further leakage of fuel gas can be prevented.

[0107] Specifically, when the second external gas detection unit 27 detects a fuel gas at a predetermined concentration TH3 or higher, the control unit 171 controls the shut-off unit 57 to shut off the fuel gas. The predetermined concentration TH3 is determined in advance experimentally and / or empirically.

[0108] Furthermore, if the second external gas detection unit 27 detects fuel gas, the first air supply unit 215 continues to supply air to the fuel cell housing 19. As a result, the inside of the fuel cell housing 19 is ventilated by the air supply. Consequently, fuel gas that has leaked due to force majeure is exhausted from the second ventilation port 213. Thus, the accumulation of fuel gas in the fuel cell housing 19 containing the fuel cell 51 can be effectively suppressed.

[0109] Next, the fuel gas shutoff method according to Embodiment 3 will be described with reference to Figures 6 and 7. Figure 7 is a flowchart of the fuel gas shutoff method. As shown in Figure 7, the fuel gas shutoff method includes steps S21 to S26.

[0110] As shown in Figures 6 and 7, first, in step S21, the control unit 171 determines whether or not the first internal gas detection unit 23 has detected fuel gas. This is the same as in step S1 shown in Figure 3.

[0111] If it is determined in step S21 that fuel gas has been detected (Yes), the process proceeds to step S26.

[0112] On the other hand, if it is determined in step S21 that no fuel gas is detected (No), the process proceeds to step S22.

[0113] Next, in step S22, the control unit 171 determines whether or not the second external gas detection unit 27 has detected fuel gas.

[0114] If it is determined in step S22 that fuel gas has been detected (Yes), the process proceeds to step S26. For example, if the second external gas detection unit 27 detects fuel gas at a predetermined concentration of TH3 or higher, the process proceeds to step S26.

[0115] On the other hand, if it is determined in step S22 that no fuel gas is detected (No), the process proceeds to step S23. For example, if the second external gas detection unit 27 detects fuel gas at a concentration of less than a predetermined TH3 (including cases where the second external gas detection unit 27 does not detect fuel gas), the process proceeds to step S23.

[0116] Next, in step S23, the control unit 171 determines whether the first external gas detection unit 24 has detected a flammable gas. This is the same as in step S12 in Figure 5.

[0117] If it is determined in step S23 that a flammable gas has been detected (Yes), the process proceeds to step S25.

[0118] On the other hand, if it is determined in step S23 that no flammable gas is detected (No), the process proceeds to step S24.

[0119] Next, in step S24, the control unit 171 determines whether or not the first fire detection unit 25 has detected a fire.

[0120] If it is determined in step S24 that no fire has been detected (No), the process proceeds to step S21.

[0121] On the other hand, if it is determined in step S24 that a fire has been detected (Yes), the process proceeds to step S25.

[0122] Next, in step S25, the control unit 171 controls the first air supply unit 215 to stop it. As a result, the first air supply unit 215 stops supplying air to the fuel cell housing 19. In other words, if it is determined in step S23 that a flammable gas has been detected, or if it is determined in step S24 that a fire has been detected, the first air supply unit 215 will stop.

[0123] Next, in step S26, the control unit 171 controls the shut-off unit 57 to shut off the fuel gas flowing through the fuel gas piping 63. As a result, the shut-off unit 57 shuts off the fuel gas supplied to the fuel cell 51. In other words, if it is determined in step S21 that fuel gas has been detected, if it is determined in step S22 that fuel gas has been detected, if it is determined in step S23 that combustible gas has been detected, or if it is determined in step S24 that a fire has been detected, the shut-off unit 57 shuts off the fuel gas supplied to the fuel cell 51. Then the process ends.

[0124] The order of steps S21, S22, S23, and S24 is not particularly limited and can be any order, and they may be executed in parallel. In this case, for example, if a positive result (Yes) is obtained in any of steps S21 to S24, the process proceeds to steps S25 and S26. The order of steps S25 and S26 is also not particularly limited and can be any order, and they may be executed in parallel. Therefore, for example, if a positive result (Yes) is obtained in any of steps S21 to S24, the process in step S25 and the process in step S26 may be executed simultaneously, or one of the processes may be executed slightly earlier by a split second.

[0125] Furthermore, the control unit 171 may perform the following processing, for example. For example, if the concentration of fuel gas detected by the first internal gas detection unit 23 reaches "20%LEL", if the concentration of fuel gas detected by the second external gas detection unit 27 reaches "20%LEL", or if the concentration of combustible gas detected by the first external gas detection unit 24 reaches "20%LEL", the control unit 171 will issue a warning signal. Then, for example, if the concentration of fuel gas detected by the first internal gas detection unit 23 reaches "40%LEL", if the concentration of fuel gas detected by the second external gas detection unit 27 reaches "40%LEL", or if the concentration of combustible gas detected by the first external gas detection unit 24 reaches "40%LEL", the control unit 171 will issue an alarm signal, control the shut-off unit 57 to shut off the fuel gas supplied to the fuel cell 51, and stop the first air supply unit 215.

[0126] (Embodiment 4) Referring to Figure 8, a fuel cell vessel 100 according to Embodiment 4 of the present invention will be described. Embodiment 4 differs from Embodiment 3 in that the fuel cell vessel 100 is equipped with a fuel container 40 and piping containers 70 and 80. The configuration of the fuel cell vessel 100 according to Embodiment 4 is the same as the configuration of the fuel cell vessel 100 shown in Figure 1. The differences between Embodiment 4 and Embodiment 3 will be mainly described below.

[0127] Figure 8 shows a part of the internal structure of the fuel cell ship 100 according to Embodiment 4. In Figure 8, the airflow is indicated by dashed arrows.

[0128] As shown in Figure 8, the fuel cell ship 100 further comprises an engine room 18 and bulkheads W1 and W2. The engine room 18 is located below the deck 1a. The fuel cell housing 19 is located in the engine room 18. The engine room 18 is separated from other spaces by bulkheads W1 and W2. The material of bulkheads W1 and W2 is, for example, fiber-reinforced plastic or sheet metal.

[0129] The duct 214 connected to the fuel cell housing 19 extends from the first ventilation opening 211 to the deck 1a and is exposed from the upper surface of the deck 1a. The first air supply unit 215 is located at the deck 1a side end of the duct 214. The first air supply unit 215 and the first external gas detection unit 24 are located above the deck 1a. The first air supply unit 215 and the first external gas detection unit 24 may also be located in the engine room 18. The first exhaust pipe 56 connected to the fuel cell 51 extends outside the vessel. The first exhaust pipe 56 may, for example, extend into an open space above the deck 1a.

[0130] As shown in Figure 8, the fuel cell ship 100 further comprises a fuel container 40, a second ventilation unit 41, a third external gas detection unit 42, a gas piping 45, a fuel gas piping 46, a shutoff unit 47, a second internal gas detection unit 48, and a second fire detection unit 49.

[0131] The fuel container 40 houses the fuel gas storage section 6. In other words, the fuel container 40 has a space for housing the fuel gas storage section 6. In the example shown in Figure 8, in addition to the fuel gas storage section 6, the fuel container 40 houses the shut-off section 47, the second internal gas detection section 48, the second fire detection section 49, a portion of the gas piping 45, and a portion of the fuel gas piping 46.

[0132] The fuel container 40 is made of, for example, fiber-reinforced plastic or sheet metal. The fuel container 40 has a hollow shape. For example, the fuel container 40 has a hollow, substantially rectangular parallelepiped shape. In this case, the fuel container 40 has, for example, a top wall 40a, a bottom wall 40b, a front wall (not shown), a rear wall (not shown), side walls 40c, and side walls 40d. However, the top, bottom, front, rear, and sides of the fuel container 40 can be arbitrarily determined. Furthermore, the shape of the fuel container 40 is not particularly limited as long as it has space to accommodate the fuel gas storage unit 6. The fuel container 40 can also be considered as a container, chamber, or box that houses the fuel gas storage unit 6. The fuel container 40 is located below the deck 1a of the hull 1.

[0133] One end of the fuel gas piping 46 is connected to the fuel gas storage unit 6. The other end of the fuel gas piping 46 is connected to one end of the fuel gas piping 63. The other end of the fuel gas piping 63 is connected to the fuel cell 51. Therefore, fuel gas is supplied from the fuel gas storage unit 6 to the fuel cell 51 through the fuel gas piping 46 and the fuel gas piping 63. In other words, the fuel gas piping 46 and the fuel gas piping 63 are pipes that supply fuel gas to the fuel cell 51.

[0134] The shut-off unit 47 is located in the fuel gas piping 46 and opens or closes the flow path of the fuel gas piping 46. Specifically, the shut-off unit 47 switches the supply of fuel gas to the fuel cell 51 on and off. Therefore, the shut-off unit 47 can shut off the fuel gas supplied to the fuel cell 51. Typically, the shut-off unit 47 is a shut-off valve.

[0135] The second ventilation unit 41 ventilates the inside of the fuel container 40. Therefore, according to Embodiment 4, even if fuel gas (combustible gas) leaks inside the fuel container 40 due to force majeure, the fuel gas can be discharged to the outside of the fuel container 40. Also, even if combustible gas (fuel gas or other combustible gas) enters the fuel container 40 due to force majeure, the combustible gas can be discharged to the outside of the fuel container 40.

[0136] Therefore, according to Embodiment 4, it is possible to suppress the accumulation of combustible gas (fuel gas or other combustible gas) in the fuel container 40.

[0137] Specifically, the second ventilation unit 41 has a third ventilation opening 411, a fourth ventilation opening 412, and a second air supply unit 413. The second ventilation unit 41 may further have a duct 414 and a duct 415.

[0138] The third ventilation opening 411 is located in the fuel container 40 and connects the inside and outside of the fuel container 40. In Embodiment 4, the third ventilation opening 411 is located at the bottom of the fuel container 40. In the example shown in Figure 8, the third ventilation opening 411 is located at the bottom of the side wall 40c. For example, the third ventilation opening 411 may be located on the bottom wall 40b on the side of the side wall 40c. However, the location of the third ventilation opening 411 is not particularly limited as long as ventilation is possible. The third ventilation opening 411 is a ventilation opening for supplying air.

[0139] The duct 414 is connected to the fuel container 40. The duct 414 extends from the third ventilation opening 411 of the fuel container 40 to the deck 1a and is exposed from the deck 1a. The second air supply unit 413 is located at the deck 1a side end of the duct 414. The second air supply unit 413 and the third external gas detection unit 42 are located above the deck 1a. The second air supply unit 413 and the third external gas detection unit 42 may also be located in the fuel chamber 22.

[0140] The second air supply unit 413 is, for example, an air supply fan. One or more filters (not shown) may be placed in the second air supply unit 413. The second air supply unit 413 is preferably a non-explosion-proof air supply fan because it is inexpensive. However, the second air supply unit 413 may also be an explosion-proof air supply fan. The filters remove, for example, dust or sea salt particles. The control unit 171 shown in Figure 1 controls the second air supply unit 413.

[0141] The second air supply unit 413 supplies outside air to the fuel container 40 through the duct 414 and the third ventilation opening 411. Therefore, the inside of the fuel container 40 is ventilated by the supply of air. As a result, the accumulation of combustible gases (fuel gas or other combustible gases) in the fuel container 40 can be effectively suppressed. The arrangement of the second air supply unit 413 is not particularly limited as long as it is possible to supply air to the fuel container 40 through the third ventilation opening 411. For example, the second air supply unit 413 may be located at the third ventilation opening 411.

[0142] Specifically, the second air supply unit 413 supplies air, so outside air is supplied to the inside of the fuel container 40 through the third ventilation opening 411. Then, exhaust is carried out through the fourth ventilation opening 412. As a result, the inside of the fuel container 40 is ventilated.

[0143] The fourth ventilation opening 412 is located in the fuel container 40 and connects the inside and outside of the fuel container 40. In Embodiment 4, the fourth ventilation opening 412 is located at the top of the fuel container 40. In the example in Figure 8, the fourth ventilation opening 412 is located on the top wall 40a on the side of the side wall 40d. For example, the fourth ventilation opening 412 may be located at the top of the side wall 40d. However, the location of the fourth ventilation opening 412 is not particularly limited as long as ventilation is possible. The fourth ventilation opening 412 is a ventilation opening for exhaust.

[0144] Duct 415 is connected to the fuel container 40. Duct 415 extends from the fourth ventilation opening 412 to the outside of deck 1a. Therefore, exhaust is carried out through the fourth ventilation opening 412 and duct 415.

[0145] Specifically, air is supplied to the inside of the fuel container 40 by the second air supply unit 413 through the duct 414 and the third ventilation opening 411. The air is then exhausted through the fourth ventilation opening 412 and the duct 415.

[0146] The third external gas detection unit 42 is located outside the fuel container 40. The third external gas detection unit 42 detects combustible gas (fuel gas or other combustible gas) flowing into the fuel container 40 from the outside. The third external gas detection unit 42 is, for example, a combustible gas sensor. The third external gas detection unit 42 outputs a signal indicating the combustible gas concentration to the control unit 171.

[0147] Specifically, the third external gas detection unit 42 is positioned outside the fuel container 40, corresponding to the second air supply unit 413. More specifically, the third external gas detection unit 42 is positioned upstream of the airflow relative to the second air supply unit 413. In the example shown in Figure 8, the third external gas detection unit 42 is positioned outside the second air supply unit 413, near the air inlet 413a of the second air supply unit 413. The third external gas detection unit 42 detects combustible gas flowing from outside the fuel container 40 into the third ventilation opening 411. In other words, the third external gas detection unit 42 detects combustible gas flowing from outside the fuel container 40 toward the second air supply unit 413.

[0148] The control unit 171 (Figure 1) stops the second air supply unit 413 when the third external gas detection unit 42 detects a flammable gas. Therefore, according to Embodiment 4, it is possible to prevent the flammable gas from entering the fuel container 40 through the third ventilation opening 411. In addition, even if the second air supply unit 413 does not have an explosion-proof structure, it is possible to prevent unintended interactions between the flammable gas and the second air supply unit 413.

[0149] Specifically, when the third external gas detection unit 42 detects a flammable gas at a predetermined concentration TH4 or higher, the control unit 171 stops the second air supply unit 413. The predetermined concentration TH4 is determined in advance experimentally and / or empirically.

[0150] In addition, if the third external gas detection unit 42 detects a combustible gas, the control unit 171 controls the shut-off unit 47 to shut off the fuel gas supplied to the fuel cell 51. Consequently, the shut-off unit 47 shuts off the fuel gas in the fuel gas piping 46. As a result, the supply of fuel gas to the fuel cell 51 is stopped, and the power generation of the fuel cell 51 stops.

[0151] Specifically, when the third external gas detection unit 42 detects a combustible gas at a predetermined concentration of TH4 or higher, the control unit 171 controls the shut-off unit 47 to shut off the fuel gas.

[0152] The second internal gas detection unit 48 is located inside the fuel container 40. For example, the second internal gas detection unit 48 is located on the upper inner surface of the fuel container 40.

[0153] The second internal gas detection unit 48 detects the fuel gas. Typically, the fuel gas is hydrogen gas, so the second internal gas detection unit 48 is, for example, a hydrogen gas sensor. The second internal gas detection unit 48 outputs a signal indicating the fuel gas concentration (hydrogen gas concentration) to the control unit 171.

[0154] When the second internal gas detection unit 48 detects fuel gas, the control unit 171 controls the shut-off unit 47 to shut off the fuel gas supplied to the fuel cell 51. Accordingly, the shut-off unit 47 shuts off the fuel gas in the fuel gas piping 46. For example, if the second internal gas detection unit 48 detects fuel gas, there is a possibility that fuel gas has leaked inside the fuel container 40 due to force majeure. Therefore, by shutting off the fuel gas in the fuel gas piping 46, further leakage of fuel gas can be prevented.

[0155] Specifically, when the second internal gas detection unit 48 detects a fuel gas at a predetermined concentration TH5 or higher, the control unit 171 controls the shut-off unit 47 to shut off the fuel gas. The predetermined concentration TH5 is determined in advance experimentally and / or empirically.

[0156] The second internal gas detection unit 48 may be located, for example, in the fourth ventilation opening 412. Alternatively, the second internal gas detection unit 48 may be located upstream of the exhaust (air) flow to the fourth ventilation opening 412 and in the vicinity of the fourth ventilation opening 412.

[0157] The second fire detection unit 49 is located inside the fuel container 40. Specifically, the second fire detection unit 49 is located on the upper inner surface of the fuel container 40. In the example shown in Figure 8, the second fire detection unit 49 is located on the top wall 40a of the fuel container 40.

[0158] The second fire detection unit 49 detects a fire occurring inside the fuel container 40 and outputs a signal to the control unit 171 indicating that a fire has occurred. The configuration of the second fire detection unit 49 is the same as that of the first fire detection unit 25.

[0159] When the second fire detection unit 49 detects a fire, the control unit 171 controls the shut-off unit 47 to shut off the fuel gas supplied to the fuel cell 51. As a result, the shut-off unit 47 shuts off the fuel gas in the fuel gas piping 46.

[0160] Here, the control unit 171 may perform the same processing as shown in the flowchart of Figure 5 based on the detection results of the third external gas detection unit 42, the second internal gas detection unit 48, and the second fire detection unit 49.

[0161] Furthermore, if the second internal gas detection unit 48 detects fuel gas, the third external gas detection unit 42 detects combustible gas, or the second fire detection unit 49 detects a fire, the control unit 171 may control the shut-off unit 57 to shut off the fuel gas.

[0162] Furthermore, if the first internal gas detection unit 23 detects fuel gas, the first external gas detection unit 24 detects combustible gas, the second external gas detection unit 27 detects fuel gas, or the first fire detection unit 25 detects a fire, the control unit 171 may control the shut-off unit 47 to shut off the fuel gas.

[0163] Furthermore, if the second internal gas detection unit 48 detects fuel gas, the third external gas detection unit 42 detects combustible gas, the second fire detection unit 49 detects a fire, the first internal gas detection unit 23 detects fuel gas, the first external gas detection unit 24 detects combustible gas, the second external gas detection unit 27 detects fuel gas, or the first fire detection unit 25 detects a fire, the control unit 171 may simultaneously control the shut-off unit 57 and the shut-off unit 47 to shut off the fuel gas. As a result, the shut-off unit 57 and the shut-off unit 47 shut off the fuel gas substantially simultaneously.

[0164] Furthermore, if the second internal gas detection unit 48 detects fuel gas, the third external gas detection unit 42 detects combustible gas, the second fire detection unit 49 detects a fire, the first internal gas detection unit 23 detects fuel gas, the first external gas detection unit 24 detects combustible gas, the second external gas detection unit 27 detects fuel gas, or the first fire detection unit 25 detects a fire, the control unit 171 may simultaneously control the shut-off unit 57 and the shut-off unit 47 to shut off the fuel gas, while simultaneously controlling the opening / closing unit 86 to open the flow path of the gas piping 85. As a result, substantially simultaneously, the shut-off unit 57 and the shut-off unit 47 shut off the fuel gas, and the opening / closing unit 86 opens the flow path of the gas piping 85. Therefore, the fuel gas remaining in the fuel gas piping 46, 63 between the shut-off unit 47 and the shut-off unit 57 can be released overboard through the gas piping 85, thus more effectively stopping the supply of fuel gas to the fuel cell 51.

[0165] As shown in Figure 8, the fuel cell ship 100 further comprises a fuel room 22 and bulkhead W3. The fuel room 22 is located below the deck 1a. The fuel container 40 is located in the fuel room 22. The fuel room 22 is separated from other spaces by bulkheads W2 and W3. The material of bulkheads W2 and W3 is, for example, fiber-reinforced plastic or sheet metal. In the example in Figure 8, the fuel room 22 and the engine room 18 are adjacent to each other, and bulkhead W2 is located between the fuel room 22 and the engine room 18.

[0166] Furthermore, the fuel cell ship 100 also includes a piping housing 80, a third ventilation unit 81, a fourth external gas detection unit 82, a gas pipe 85, an opening / closing unit 86, and a third internal gas detection unit 87.

[0167] The piping housing 80 is located in the engine room 18. The piping housing 80 houses a portion of the fuel gas piping 46, a portion of the fuel gas piping 63, a portion of the gas piping 45, a portion of the gas piping 85, and the opening / closing section 86 (hereinafter referred to as "a portion of the fuel gas piping 46, etc.").

[0168] The material of the piping housing 80 is, for example, fiber-reinforced plastic or sheet metal. The piping housing 80 has a hollow shape. For example, the piping housing 80 has a hollow, substantially rectangular parallelepiped shape. In this case, the piping housing 80 has, for example, a top wall 80a, a bottom wall 80b, a front wall (not shown), a rear wall (not shown), side walls 80c, and side walls 80d. However, the top, bottom, front, rear, and sides of the piping housing 80 can be arbitrarily determined. Furthermore, the shape of the piping housing 80 is not particularly limited as long as it has space to accommodate a part of the fuel gas piping 46, etc. The piping housing 80 can also be considered as a container, chamber, or box that accommodates a part of the fuel gas piping 46, etc. The piping housing 80 is, for example, located below the deck 1a of the hull 1.

[0169] One end of the gas pipe 85 is connected to the fuel gas pipe 46 and the fuel gas pipe 63. The other end of the gas pipe 85 is located inside the duct 415.

[0170] The opening / closing unit 86 is located in the gas piping 85. The opening / closing unit 86 opens or closes the flow path of the gas piping 85. The opening / closing unit 86 is, for example, an on / off valve.

[0171] The third ventilation unit 81 ventilates the inside of the pipe housing 80. Therefore, according to Embodiment 4, even if fuel gas (combustible gas) leaks inside the pipe housing 80 due to force majeure, the fuel gas can be discharged to the outside of the pipe housing 80. Also, even if combustible gas (fuel gas or other flammable gas) enters the pipe housing 80 due to force majeure, the combustible gas can be discharged to the outside of the pipe housing 80.

[0172] Therefore, according to Embodiment 4, it is possible to suppress the accumulation of combustible gas (fuel gas and other combustible gases) in the piping housing 80 that houses a part of the fuel gas piping 46.

[0173] Specifically, the third ventilation unit 81 has a fifth ventilation opening 811, a sixth ventilation opening 812, and a third air supply unit 813. The third ventilation unit 81 may further have a duct 814.

[0174] The fifth ventilation opening 811 is located in the pipe housing 80 and connects the inside and outside of the pipe housing 80. In Embodiment 4, the fifth ventilation opening 811 is located at the bottom of the pipe housing 80. In the example in Figure 8, the fifth ventilation opening 811 is located at the bottom of the side wall 80d. For example, the fifth ventilation opening 811 may be located on the bottom wall 80b on the side of the side wall 80d. However, the location of the fifth ventilation opening 811 is not particularly limited as long as ventilation is possible. The fifth ventilation opening 811 is a ventilation opening for supplying air.

[0175] The duct 814 is connected to the piping housing 80. The duct 814 extends from the fifth ventilation opening 811 of the piping housing 80 to the deck 1a and is exposed from the deck 1a. The third air supply unit 813 is located at the deck 1a side end of the duct 814. The third air supply unit 813 and the fourth external gas detection unit 82 are located above the deck 1a. The third air supply unit 813 and the fourth external gas detection unit 82 may also be located in the fuel chamber 22.

[0176] The third air supply unit 813 is, for example, an air supply fan. Preferably, the third air supply unit 813 is a non-explosion-proof air supply fan because it is inexpensive. However, the third air supply unit 813 may be an explosion-proof air supply fan. One or more filters (not shown) may be placed in the third air supply unit 813. The filters remove, for example, dust or sea salt particles. The control unit 171 controls the third air supply unit 813.

[0177] The third air supply unit 813 supplies outside air to the inside of the piping housing 80 through the duct 814 and the fifth ventilation opening 811. As a result, the inside of the piping housing 80 is ventilated by the supply of air. Consequently, the accumulation of flammable gas (fuel gas or other flammable gases) in the piping housing 80, which houses part of the fuel gas piping 46, can be effectively suppressed. The arrangement of the third air supply unit 813 is not particularly limited as long as it is possible to supply air to the piping housing 80 through the fifth ventilation opening 811. For example, the third air supply unit 813 may be located at the fifth ventilation opening 811.

[0178] Specifically, the third air supply unit 813 supplies air, so outside air from the piping housing 80 is supplied to the inside of the piping housing 80 through the fifth ventilation opening 811. Then, exhaust air is carried out through the sixth ventilation opening 812. As a result, the inside of the piping housing 80 is ventilated.

[0179] The sixth ventilation opening 812 is located in the pipe housing 80 and connects the inside and outside of the pipe housing 80. In Embodiment 4, the sixth ventilation opening 812 is located at the top of the pipe housing 80. In the example in Figure 8, the sixth ventilation opening 812 is located on the top wall 80a. For example, the sixth ventilation opening 812 may be located at the top of the side wall 80c. However, the location of the sixth ventilation opening 812 is not particularly limited as long as ventilation is possible. The sixth ventilation opening 812 is a ventilation opening for exhaust.

[0180] The fourth external gas detection unit 82 is located outside the piping housing 80. The fourth external gas detection unit 82 detects combustible gas (fuel gas or other combustible gas) flowing into the piping housing 80 from the outside. The fourth external gas detection unit 82 is, for example, a combustible gas sensor. The fourth external gas detection unit 82 outputs a signal indicating the combustible gas concentration to the control unit 171.

[0181] Specifically, the fourth external gas detection unit 82 is positioned outside the piping housing 80, corresponding to the third air supply unit 813. More specifically, the fourth external gas detection unit 82 is positioned upstream of the airflow relative to the third air supply unit 813. In the example shown in Figure 8, the fourth external gas detection unit 82 is positioned outside the third air supply unit 813, near the air inlet 813a of the third air supply unit 813. The fourth external gas detection unit 82 detects combustible gas flowing from outside the piping housing 80 into the fifth ventilation opening 811. In other words, the fourth external gas detection unit 82 detects combustible gas flowing from outside the piping housing 80 toward the third air supply unit 813.

[0182] The control unit 171 (Figure 1) stops the third air supply unit 813 when the fourth external gas detection unit 82 detects a flammable gas. Therefore, according to Embodiment 4, it is possible to prevent the flammable gas from entering the piping housing 80 through the fifth ventilation opening 811. In addition, even if the third air supply unit 813 does not have an explosion-proof structure, it is possible to prevent unintended interactions between the flammable gas and the third air supply unit 813.

[0183] Specifically, when the fourth external gas detection unit 82 detects a flammable gas at a predetermined concentration TH6 or higher, the control unit 171 stops the third air supply unit 813. The predetermined concentration TH6 is determined in advance experimentally and / or empirically.

[0184] In addition, if the fourth external gas detection unit 82 detects a combustible gas, the control unit 171 controls the shut-off unit 47 to shut off the fuel gas supplied to the fuel cell 51. Consequently, the shut-off unit 47 shuts off the fuel gas in the fuel gas piping 46. As a result, the supply of fuel gas to the fuel cell 51 is stopped, and the power generation of the fuel cell 51 stops.

[0185] Specifically, when the fourth external gas detection unit 82 detects a combustible gas at a predetermined concentration of TH6 or higher, the control unit 171 controls the shut-off unit 47 to shut off the fuel gas.

[0186] The third internal gas detection unit 87 is located inside the piping housing 80. For example, the third internal gas detection unit 87 is located on the upper inner surface of the piping housing 80.

[0187] The third internal gas detection unit 87 detects the fuel gas. Typically, the fuel gas is hydrogen gas, so the third internal gas detection unit 87 is, for example, a hydrogen gas sensor. The third internal gas detection unit 87 outputs a signal indicating the fuel gas concentration (hydrogen gas concentration) to the control unit 171.

[0188] When the third internal gas detection unit 87 detects fuel gas, the control unit 171 controls the shut-off unit 47 to shut off the fuel gas supplied to the fuel cell 51. Accordingly, the shut-off unit 47 shuts off the fuel gas in the fuel gas piping 46. For example, if the third internal gas detection unit 87 detects fuel gas, there is a possibility that fuel gas has leaked inside the piping housing 80 due to force majeure. Therefore, by shutting off the fuel gas in the fuel gas piping 46, further leakage of fuel gas can be prevented.

[0189] Specifically, when the third internal gas detection unit 87 detects a fuel gas at a predetermined concentration TH7 or higher, the control unit 171 controls the shut-off unit 47 to shut off the fuel gas. The predetermined concentration TH7 is determined in advance experimentally and / or empirically.

[0190] The third internal gas detection unit 87 may be located, for example, at the sixth ventilation port 812. Alternatively, the third internal gas detection unit 87 may be located upstream of the exhaust (air) flow to the sixth ventilation port 812, and in the vicinity of the sixth ventilation port 812. The fuel cell ship 100 does not necessarily have to be equipped with the third internal gas detection unit 87. Even if fuel gas leaks within the piping housing 80, the fuel gas will flow out into the piping housing 70, and the fourth internal gas detection unit 94 can detect the fuel gas.

[0191] Here, the control unit 171 may perform the same processing as shown in the flowchart of Figure 5 (excluding step S13) based on the detection results of the fourth external gas detection unit 82 and the third internal gas detection unit 87.

[0192] Furthermore, if the third internal gas detection unit 87 detects fuel gas, or if the fourth external gas detection unit 82 detects combustible gas, the control unit 171 may control the shut-off unit 57 to shut off the fuel gas.

[0193] As shown in Figure 8, the fuel cell ship 100 further comprises a piping housing 70, a fourth ventilation section 72, a fuel gas inlet 74, a first check valve 76, an inert gas inlet 77, an opening / closing section 78, a second check valve 79, an inert gas piping 92, and a fourth internal gas detection section 94.

[0194] The piping housing 70 is located on the upper part of deck 1a. The piping housing 70 houses a portion of the gas piping 45, a portion of the gas piping 85, the inert gas piping 92, the first check valve 76, the opening / closing section 78, and the second check valve 79 (hereinafter referred to as "a portion of the gas piping 45, etc.").

[0195] The material of the pipe housing 70 is, for example, fiber-reinforced plastic. The pipe housing 70 has a hollow shape. For example, the pipe housing 70 has a hollow, substantially rectangular parallelepiped shape. In this case, the pipe housing 70 has, for example, a top wall 70a, a bottom wall 70b, a front wall (not shown), a rear wall (not shown), side walls 70c, and side walls 70d. However, the top, bottom, front, rear, and sides of the pipe housing 70 can be arbitrarily determined. Furthermore, the shape of the pipe housing 70 is not particularly limited as long as it has space to accommodate a part of the gas piping 45, etc. The pipe housing 70 can also be considered as a container, chamber, or box that accommodates a part of the gas piping 45, etc. Note that the pipe housing 70 and the pipe housing 80 may be formed as the same housing and communicate with each other.

[0196] One end of the gas pipe 45 is connected to the fuel gas storage unit 6, and the other end of the gas pipe 45 is connected to the fuel gas inlet 74. The first check valve 76 is located upstream of the gas pipe 45. Fuel gas is supplied to the fuel gas inlet 74. The fuel gas is then introduced into the fuel gas storage unit 6 through the first check valve 76 and the gas pipe 45. As a result, fuel gas is stored in the fuel gas storage unit 6. Since the fuel gas passes through the gas pipe 45, the gas pipe 45 can also be considered as the "fuel gas pipe". The first check valve 76 prevents backflow of fuel gas.

[0197] When fuel gas is supplied to the fuel gas inlet 74, the opening / closing section 78 closes the flow path of the inert gas pipe 92.

[0198] One end of the inert gas pipe 92 is connected upstream of the gas pipe 45, and the other end of the inert gas pipe 92 is connected to the inert gas inlet 77. An on / off section 78 and a second check valve 79 are provided in the inert gas pipe 92. The second check valve 79 is located downstream of the on / off section 78. The on / off section 78 opens or closes the flow path of the inert gas pipe 92. The on / off section 78 is, for example, an on / off valve. However, the fuel cell ship 100 does not need to have an on / off section 78, because the fuel cell ship 100 has a second check valve 79.

[0199] When fuel gas is not supplied to the fuel gas inlet 74, inert gas is supplied to the inert gas inlet 77. The inert gas is typically nitrogen gas. When the opening / closing unit 78 opens the flow path of the inert gas piping 92, the inert gas is introduced into the fuel gas storage unit 6 through the second check valve 79 and the gas piping 45. Furthermore, when the shut-off unit 47 opens the flow path of the fuel gas piping 46, the opening / closing unit 86 opens the flow path of the gas piping 85, and the shut-off unit 57 closes the flow path of the fuel gas piping 63, the inert gas is discharged from the fuel gas storage unit 6 through the fuel gas piping 46, the gas piping 85, the eighth ventilation opening 721, and the duct 724 to the duct 415. In other words, the fuel gas is purged by the inert gas. Note that during purging, the gas piping 85 can also be considered as the "fuel gas piping" because the fuel gas passes through it.

[0200] The fourth ventilation unit 72 ventilates the inside of the pipe housing 70. Therefore, according to Embodiment 4, even if fuel gas (combustible gas) leaks inside the pipe housing 70 due to force majeure, the fuel gas can be discharged to the outside of the pipe housing 70. Also, even if combustible gas (fuel gas or other flammable gas) enters the pipe housing 70 due to force majeure, the combustible gas can be discharged to the outside of the pipe housing 70.

[0201] Therefore, according to Embodiment 4, it is possible to suppress the accumulation of combustible gas (fuel gas and other combustible gases) in the pipe housing 70 that houses a part of the gas pipe 45.

[0202] Specifically, the fourth ventilation section 72 has an eighth ventilation opening 721 and a ninth ventilation opening 722. The fourth ventilation section 72 may further have a duct 724.

[0203] The eighth ventilation opening 721 is located in the pipe housing 70 and connects the inside and outside of the pipe housing 70. In Embodiment 4, the eighth ventilation opening 721 is located at the bottom of the pipe housing 70. In the example in Figure 8, the eighth ventilation opening 721 is located in the bottom wall 70b. However, the location of the eighth ventilation opening 721 is not particularly limited as long as ventilation is possible. The eighth ventilation opening 721 is a ventilation opening for supplying air.

[0204] The ninth ventilation opening 722 is located in the pipe housing 70 and connects the inside and outside of the pipe housing 70. In Embodiment 4, the ninth ventilation opening 722 is located on the upper inside of the pipe housing 70. However, the location of the ninth ventilation opening 722 is not particularly limited as long as ventilation is possible. The ninth ventilation opening 722 is a ventilation opening for exhaust.

[0205] The base end of duct 724 is connected to the ninth ventilation opening 722. The tip of duct 724 is located inside duct 415. Therefore, air flows from the eighth ventilation opening 721 into the piping housing 70 and is exhausted into duct 415 through the ninth ventilation opening 722 and duct 724. The exhaust from piping housing 70 may be directed independently outwards without joining duct 415.

[0206] The fourth internal gas detection unit 94 is located inside the piping housing 70. For example, the fourth internal gas detection unit 94 is located on the upper inner surface of the piping housing 70.

[0207] The fourth internal gas detection unit 94 detects the fuel gas. Typically, the fuel gas is hydrogen gas, so the fourth internal gas detection unit 94 is, for example, a hydrogen gas sensor. The fourth internal gas detection unit 94 outputs a signal indicating the fuel gas concentration (hydrogen gas concentration) to the control unit 171.

[0208] When the fourth internal gas detection unit 94 detects fuel gas, the control unit 171 controls the shut-off unit 47 to shut off the fuel gas supplied to the fuel cell 51. Accordingly, the shut-off unit 47 shuts off the fuel gas in the fuel gas piping 46. For example, if the fourth internal gas detection unit 94 detects fuel gas, there is a possibility that fuel gas has leaked inside the piping housing 70 due to force majeure. Therefore, by shutting off the fuel gas in the fuel gas piping 46, further leakage of fuel gas can be prevented.

[0209] Specifically, when the fourth internal gas detection unit 94 detects a fuel gas at a predetermined concentration TH8 or higher, the control unit 171 controls the shut-off unit 47 to shut off the fuel gas. The predetermined concentration TH8 is determined in advance experimentally and / or empirically.

[0210] The fourth internal gas detection unit 94 may be located, for example, in the ninth ventilation opening 722. Alternatively, the fourth internal gas detection unit 94 may be located upstream of the exhaust (air) flow to the ninth ventilation opening 722 and in the vicinity of the ninth ventilation opening 722.

[0211] Here, the control unit 171 may perform the same processing as shown in the flowchart of Figure 3 (excluding step S2) based on the detection result of the fourth internal gas detection unit 94.

[0212] Furthermore, if the fourth internal gas detection unit 94 detects fuel gas, the control unit 171 may control the shut-off unit 57 to shut off the fuel gas.

[0213] As shown in Figure 8, the fuel cell ship 100 further comprises a connecting section 98 and a connecting section 99. The connecting section 98 connects the pipe housing 70 and the pipe housing 80. Specifically, it connects the eighth ventilation opening 721 of the pipe housing 70 and the sixth ventilation opening 812 of the pipe housing 80. The connecting section 98 is, for example, a pipe. In other words, the connecting section 98 is a hollow member that connects the pipe housing 70 and the pipe housing 80.

[0214] According to Embodiment 4, by providing the communication section 98, exhaust from the piping housing 80 can be carried out via the communication section 98 and the piping housing 70.

[0215] Specifically, air is supplied to the interior of the piping housing 80 by the third air supply unit 813 through the duct 814 and the fifth ventilation opening 811. The air is then exhausted into the duct 415 through the sixth ventilation opening 812, the connecting section 98, the eighth ventilation opening 721, the ninth ventilation opening 722, and the duct 724. The air is then exhausted through the duct 415.

[0216] Gas piping 45 extends from the fuel gas storage unit 6 to the piping housing 80, and further extends to the piping housing 70 through the sixth ventilation opening 812, the connecting section 98, and the eighth ventilation opening 721. Gas piping 85 extends from the piping housing 70 to the piping housing 70 through the sixth ventilation opening 812, the connecting section 98, and the eighth ventilation opening 721. Fuel gas piping 46 extends from the fuel gas storage unit 6 to the piping housing 80 and connects to gas piping 85 and fuel gas piping 63 inside the piping housing 80.

[0217] The connecting section 99 connects the piping housing 80 and the fuel cell housing 19. Specifically, it connects the second ventilation opening 213 of the fuel cell housing 19 to the piping housing 70. More specifically, the connecting section 99 connects the opening 80x of the piping housing 70 to the second ventilation opening 213 of the fuel cell housing 19. The opening 80x is located, for example, in the side wall 80d of the piping housing 80. The connecting section 98 is, for example, a pipe. In other words, the connecting section 99 is a hollow member that connects the piping housing 80 and the fuel cell housing 19.

[0218] According to Embodiment 4, by providing the communication section 99, exhaust gas from the fuel cell housing 19 can be discharged via the communication section 99 and the piping housing 80.

[0219] Specifically, air is supplied to the inside of the fuel cell housing 19 by the first air supply unit 215 through the duct 214 and the first ventilation opening 211. The air then enters the piping housing 80 through the second ventilation opening 213, the connecting section 99, and the opening 80x. Furthermore, the air is exhausted into the duct 415 through the sixth ventilation opening 812, the connecting section 98, the eighth ventilation opening 721, the ninth ventilation opening 722, and the duct 724. The air is then exhausted through the duct 415.

[0220] The fuel gas piping 63 extends from the fuel cell 51 through the second ventilation opening 213, the communication section 99, and the opening 80x to the piping housing 80. Inside the piping housing 80, the fuel gas piping 63 is connected to the fuel gas piping 46 and the gas piping 85.

[0221] As shown in Figure 8, the fuel cell ship 100 further includes a gas detection unit 50. The gas detection unit 50 is located inside the duct 415. The duct 415 extends from the fourth ventilation opening 412 of the fuel container 40, through the deck 1a and the piping container 70, to the outside of the piping container 70. The gas detection unit 50 is located inside the duct 415, above the duct 724.

[0222] The gas detection unit 50 detects the fuel gas. Typically, the fuel gas is hydrogen gas, so the gas detection unit 50 is, for example, a hydrogen gas sensor. The gas detection unit 50 outputs a signal indicating the fuel gas concentration to the control unit 171, for example.

[0223] When the gas detection unit 50 detects fuel gas, the control unit 171 controls the shut-off unit 47 to shut off the fuel gas supplied to the fuel cell 51. Accordingly, the shut-off unit 47 shuts off the fuel gas in the fuel gas piping 46. As a result, the supply of fuel gas to the fuel cell 51 is stopped.

[0224] Specifically, when the gas detection unit 50 detects a fuel gas at a predetermined concentration TH9 or higher, the control unit 171 controls the shut-off unit 47 to shut off the fuel gas. The predetermined concentration TH9 is determined in advance experimentally and / or empirically.

[0225] Furthermore, the control unit 171 may control the shut-off unit 57 to shut off the fuel gas when the gas detection unit 50 detects fuel gas. Note that the fuel cell ship 100 does not necessarily have to be equipped with a gas detection unit 50.

[0226] Embodiments and examples of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from the spirit of the invention (for example, (1) to (4) below). Furthermore, the multiple components disclosed in the above embodiments can be modified as appropriate. For example, some components from all the components shown in one embodiment may be added to the components of another embodiment, or some components from all the components shown in one embodiment may be deleted from the embodiment.

[0227] Furthermore, the drawings schematically show each component in order to facilitate understanding of the invention, and the thickness, length, number, spacing, etc. of each component shown may differ from the actual dimensions due to the convenience of drawing creation. Also, the configuration of each component shown in the above embodiments is merely an example and is not particularly limiting, and it goes without saying that various modifications are possible without substantially departing from the effects of the present invention.

[0228] (1) In Figure 6, the fuel cell ship 100 does not need to be equipped with the first air supply unit 215 and the first external gas detection unit 24. Also, in Figure 6, the fuel cell ship 100 does not need to be equipped with the first external gas detection unit 24.

[0229] (2) In Figure 8, the fuel cell ship 100 may have some of the sets of the first air supply unit 215 and the first external gas detection unit 24, the second air supply unit 413 and the third external gas detection unit 42, and the third air supply unit 813 and the fourth external gas detection unit 82, or it may not have all of the sets. The fuel cell ship 100 may also have an exhaust fan corresponding to at least one of the ventilation openings among the second ventilation opening 213, the fourth ventilation opening 412, the sixth ventilation opening 812, and the ninth ventilation opening 722. The exhaust fan is preferably explosion-proof. However, the exhaust fan may be non-explosion-proof.

[0230] Furthermore, in Figure 8, the fuel cell ship 100 may be equipped with some of the detection units among the first internal gas detection unit 23, first external gas detection unit 24, first fire detection unit 25, second external gas detection unit 27, third external gas detection unit 42, second internal gas detection unit 48, second fire detection unit 49, fourth external gas detection unit 82, third internal gas detection unit 87, fourth internal gas detection unit 94, and gas detection unit 50, or it may not be equipped with all of the detection units.

[0231] (3) In Figure 8, the fuel cell ship 100 may have one or more filters (not shown) in some or all of the first air intake section 215, the second air intake section 413, and the third air intake section 813. The filters remove, for example, dust or sea salt particles.

[0232] (4) In the present invention, the fuel cell ship 100 may have a second ventilation opening 213 of the fuel cell housing 19 that communicates with one of the housings, the piping housing 80 (Figure 8) and the fuel housing 40 (Figure 8), via a communication section (hereinafter referred to as "communication section P").

[0233] For example, in Embodiment 4 described with reference to Figure 8, the communication section P is the communication section 99. The communication section 99 connects the second ventilation opening 213 of the fuel cell housing 19 to the piping housing 80.

[0234] For example, the connecting part P (not shown) may connect the second ventilation opening 213 of the fuel cell housing 19 shown in Figure 8 to the fuel container 40 shown in Figure 8. In other words, the connecting part P may connect the fuel cell housing 19 and the fuel container 40 shown in Figure 8. In this case, for example, the fuel container 40 is placed next to the fuel cell housing 19. Alternatively, for example, the connecting part P connects the opening (not shown) of the fuel container 40 to the second ventilation opening 213 of the fuel cell housing 19. The opening of the fuel container 40 is located, for example, on the side wall 40d of the fuel container 40. The connecting part P is, for example, a pipe. In other words, the connecting part P is a hollow member that connects the fuel container 40 and the fuel cell housing 19.

[0235] (5) In addition to the fuel cell system 5 and the battery system 7, the fuel cell ship 100 may also be equipped with power sources other than the fuel cell system 5 and the battery system 7. The power source may be, for example, an engine-driven generator equipped with a power converter.

[0236] <Notes on the invention> According to one aspect of the present invention, a fuel cell ship comprises a propulsion system, a fuel cell, a fuel cell housing, and a first ventilation unit. The propulsion system generates propulsion force on the hull. The fuel cell supplies power to the propulsion system. The fuel cell housing houses the fuel cell. The first ventilation unit ventilates the inside of the fuel cell housing. [Industrial applicability]

[0237] This invention relates to a power generation system and has industrial applicability. [Explanation of symbols]

[0238] 1. Hull 6. Fuel gas storage section 9 Propulsion device 51 Fuel Cell 19 Fuel cell housing 21, 21A First ventilation section 24. First external gas detection unit (external gas detection unit) 27. Second external gas detection unit (external gas detection unit) 40 Fuel containers 45. Gas piping (fuel gas piping) 46 Fuel gas piping 41. Second Ventilation Unit 47, 57 Interruption section 63 Fuel gas piping 69 Cooling medium storage section 80 Pipe housing 73 1st coolant pipe (coolant pipe) 81 Third Ventilation Unit 85. Gas piping (fuel gas piping) 100 fuel cell ship 171 Control Unit 211 First ventilation opening 213 Second ventilation opening 215 1st air supply section (air supply section)

Claims

1. A fuel cell that supplies power to the ship's electrical equipment, A fuel gas pipeline through which the fuel gas supplied to the fuel cell passes, A piping housing that accommodates only a portion of the aforementioned fuel gas piping, A ventilation section for ventilating the inside of the aforementioned pipe housing and A power generation system equipped with the following features.

2. The power generation system according to claim 1, wherein the piping housing has a gas detection unit for detecting combustible gas.

3. A shut-off section that opens or closes the flow path of the fuel gas piping, A control unit that controls the aforementioned blocking unit and Furthermore, The power generation system according to claim 2, wherein when the gas detection unit detects the combustible gas, the control unit controls the shut-off unit to shut off the fuel gas.

4. The power generation system according to claim 2, wherein the gas detection unit is located outside the piping housing and detects the concentration of the combustible gas flowing into the piping housing from outside.

5. The aforementioned ventilation unit is A ventilation opening that connects the inside and outside of the aforementioned piping housing, An air supply unit that supplies air from outside the pipe housing into the inside of the pipe housing through the ventilation opening. A power generation system according to claim 1 or claim 2, comprising:

6. A fuel gas storage unit for storing the aforementioned fuel gas, The system further comprises a fuel container that houses the aforementioned fuel gas storage section, The fuel container has a gas detection unit for detecting combustible gas leaking into the fuel container, The power generation system according to claim 3, wherein when the gas detection unit of the fuel container detects the combustible gas, the control unit controls the shut-off unit to shut off the fuel gas.

Images