Safety control device and ammonia fuel ship

Abstract

According to the embodiments, a safety control device comprises an acquisition unit that acquires detection results for ammonia gas in a compartment of an ammonia fuel ship in which an ammonia fuel supply system is installed, an inference unit that infers a site of ammonia leakage from the ammonia fuel supply system on the basis of the detection results, a selection unit that selects a safety control sequence for the ammonia fuel supply system on the basis of the inferred leakage site, and a control unit that switches the operation mode of at least one of a principal engine and a generator of the ammonia fuel ship from an ammonia mode to a non-ammonia mode in accordance with the selected safety control sequence.

Description

Safety control device and ammonia-fueled ship

[0001] An embodiment of the present invention relates to a safety control device and an ammonia-fueled ship.

[0002] As one of the efforts to reduce carbon dioxide emissions, ammonia-fueled ships that use ammonia as fuel are being considered.

[0003] Ammonia, whether in liquid or gas form, has a high potential for adverse effects on the human body. Therefore, ammonia-fueled ships are required to implement measures not only to prevent ammonia leakage, but also to take measures in the event of an ammonia leak.

[0004] Patent Document 1 discloses that, as a measure to be taken in the event of an ammonia leak, a ventilation fan is installed in a room in which an ammonia fuel supply system is installed.

[0005] Japanese Patent Application Publication No. 2023-9884

[0006] The room where the ammonia fuel supply system is installed is an area with a relatively high risk of ammonia leakage because it contains equipment such as pumps, chambers, and vaporizers. On the other hand, the room where the ammonia fuel supply system is installed is designed so that people cannot enter under normal circumstances. Therefore, if an ammonia leak occurs in the ammonia fuel supply system, it is desirable to be able to accurately block the leak point without people entering and quickly remove the remaining fuel.

[0007] An object of the embodiments of the present invention is to provide a technology that can shut off an ammonia leak site and remove residual fuel without requiring human entry.

[0008] A safety control device of a first aspect according to an embodiment is a safety control device including: an acquisition unit that acquires detection results of ammonia gas within a compartment of an ammonia-fueled ship in which an ammonia fuel supply system is arranged; an estimation unit that estimates a leakage location of ammonia from the ammonia fuel supply system based on the detection results; a selection unit that selects a safety control sequence for the ammonia fuel supply system based on the estimated leakage location; and a control unit that switches the operating mode of at least one of a main engine and a generator of the ammonia-fueled ship from an ammonia mode to a non-ammonia mode in accordance with the selected safety control sequence.

[0009] In a second aspect of the embodiment, in the safety control device described in the first aspect, the control unit isolates the estimated leakage point from the ammonia fuel supply system in accordance with the selected safety control sequence, and removes ammonia remaining in the isolated leakage point.

[0010] In a third aspect of the embodiment, in the safety control device described in the second aspect, the control unit performs the isolating and removing while the compartment is closed to the outside of the compartment.

[0011] In a fourth aspect of the embodiment, in the safety control device according to the second aspect, the control unit removes ammonia remaining in the isolated leakage location with water.

[0012] In a fifth aspect according to the embodiment, in the safety control device according to the first aspect, the estimation unit further estimates a degree of ammonia leakage from the ammonia fuel supply system, and the selection unit selects a safety control sequence for the ammonia fuel supply system based on the estimated degree of leakage.

[0013] An ammonia-fueled ship of a sixth aspect according to the embodiment is an ammonia-fueled ship equipped with the safety control device according to any one of the first to fifth aspects, the ammonia fuel supply system, the main engine, and the generator.

[0014] According to the embodiment, it is possible to shut off the ammonia leakage point and remove the remaining fuel without requiring human entry.

[0015] Fig. 1 is a block diagram showing an example of the configuration of an ammonia-fueled ship according to an embodiment. Fig. 2 is a diagram showing an example of the configuration of an ammonia fuel supply system of an ammonia-fueled ship according to an embodiment. Fig. 3 is a block diagram showing an example of the hardware configuration of a safety control device of an ammonia-fueled ship according to an embodiment. Fig. 4 is a block diagram showing an example of the functional configuration of the safety control device of an ammonia-fueled ship according to an embodiment. Fig. 5 is a flowchart showing an example of safety control operation in the safety control device of an ammonia-fueled ship according to an embodiment.

[0016] The embodiments will be described with reference to the drawings. Note that the scale of each part in the drawings used in the following description of the embodiments may be changed as appropriate. Also, for the sake of explanation, the drawings used in the following description of the embodiments may omit components.

[0017] 1. Configuration First, the configuration of the ammonia-fueled ship according to the embodiment will be described.

[0018] 1.1 Main Configuration FIG. 1 is a block diagram showing an example of the configuration of an ammonia-fueled ship according to an embodiment.

[0019] The ammonia-fueled ship 1 is a ship that uses ammonia as fuel for propulsion. The ammonia-fueled ship 1 can use a substance other than ammonia (for example, heavy oil) as fuel in addition to ammonia. Hereinafter, the operation mode in which the ship is propelled using ammonia as fuel will be referred to as the "ammonia mode," and the operation mode in which the ship is propelled using a substance other than ammonia as fuel will be referred to as the "non-ammonia mode" (particularly, when heavy oil is used as fuel, it will be referred to as the "diesel mode"), and they may be distinguished from each other.

[0020] As shown in FIG. 1 , the ammonia-fueled ship 1 includes a safety control device 10 , an ammonia fuel supply system 100 , a fuel tank 200 , a main engine 300 , and a generator 400 .

[0021] The ammonia fuel supply system 100 is a system for supplying ammonia as fuel from a fuel tank 200, which is a supply source, to the main engine 300 and the generator 400, which are supply destinations, when propelling in ammonia mode. The ammonia fuel supply system 100 is also referred to as an AFSS (ammonia fuel supply system). The ammonia fuel supply system 100 is collected in a compartment different from the safety control device 10, the fuel tank 200, the main engine 300, and the generator 400. Hereinafter, the compartment where the ammonia fuel supply system 100 is collected will be referred to as an "ammonia fuel supply system room AFSSRM." In addition to a piping system, the ammonia fuel supply system 100 includes various devices such as a pump and a heater for controlling the ammonia at a predetermined pressure and temperature. Details of the ammonia fuel supply system 100 will be described later.

[0022] The fuel tank 200 is a supplier of ammonia as fuel and mainly stores liquid ammonia. The fuel tank 200 is arranged on the ammonia-fueled ship 1 as, for example, a cargo tank.

[0023] The main engine 300 is a primary engine for propelling the ammonia-fueled ship 1. The main engine 300 is configured to be switchable between being powered by ammonia and being powered by heavy oil. That is, the main engine 300 is powered by ammonia when operating in ammonia mode, and is powered by heavy oil when operating in diesel mode. When operating in ammonia mode, the main engine 300 receives liquefied ammonia as fuel from the ammonia fuel supply system 100, and discharges the liquefied ammonia that is not used as fuel to the ammonia fuel supply system 100. Although not shown in FIG. 1 , when operating in diesel mode, the main engine 300 receives heavy oil as fuel from a diesel fuel supply system (not shown), and discharges the heavy oil that is not used as fuel to the diesel fuel supply system.

[0024] The generator 400 is a power source for supplying electricity to the inside of the ammonia-fueled ship 1. The generator 400 is configured to be switchable between being driven by ammonia and being driven by heavy oil. That is, the generator 400 is driven by ammonia when operated in ammonia mode, and is driven by heavy oil when operated in diesel mode. When operated in ammonia mode, the generator 400 receives vaporized ammonia from the ammonia fuel supply system 100 as fuel. Although not shown in FIG. 1 , when operated in diesel mode, the generator 400 receives heavy oil as fuel from a diesel fuel supply system (not shown).

[0025] The safety control device 10 is, for example, an information processing device such as a computer. The safety control device 10 controls the ammonia fuel supply system 100 so as to minimize leakage of ammonia from the ammonia fuel supply system 100. The safety control device 10 acquires various pieces of information for predicting leakage of ammonia from the ammonia fuel supply system 100, and generates various pieces of information for controlling the ammonia fuel supply system 100 based on the acquired information.

[0026] 1.2 Ammonia Fuel Supply System FIG. 2 is a diagram showing an example of the configuration of an ammonia fuel supply system of an ammonia-fueled ship according to an embodiment.

[0027] 2, the ammonia fuel supply system 100 includes a low-pressure pump 101, a heat exchanger 102, a chamber 103, a high-pressure pump 104, a heat exchanger 105, a vaporizer 106, a chamber 107, a plurality of shut-off valves 108, a plurality of purge material supply valves 109, and a plurality of purge material discharge valves 110. Furthermore, a plurality of detectors 111 and a fan 112 are provided in the ammonia fuel supply system room AFSSRM.

[0028] The low-pressure pump 101 is a pump that pumps out liquefied ammonia at a predetermined pressure from the fuel tank 200. The low-pressure pump 101 pumps out the liquefied ammonia from the fuel tank 200 at a pressure lower than the pressure of the ammonia supplied to the main engine 300.

[0029] The heat exchanger 102 is a heater that heats the liquefied ammonia supplied from the low-pressure pump 101 to a predetermined temperature. The heat exchanger 102 sends the heated liquefied ammonia to the chamber 103.

[0030] The chamber 103 is a tank that temporarily stores the liquefied ammonia to be supplied to the main engine 300. The chamber 103 also functions as a recovery tank that recovers the liquefied ammonia that has not been used for combustion in the main engine 300. In other words, a circulation path for the liquefied ammonia is formed between the chamber 103 and the main engine 300.

[0031] The high-pressure pump 104 is a pump that pumps out the liquefied ammonia at high pressure from the chamber 103. The high-pressure pump 104 supplies the pumped out high-pressure liquefied ammonia to the main engine 300.

[0032] The heat exchanger 105 is a heater that heats the liquefied ammonia discharged from the main engine 300 to a predetermined temperature. The heat exchanger 105 sends the heated liquefied ammonia to the chamber 103.

[0033] The vaporizer 106 is a device that heats the liquefied ammonia supplied from the low-pressure pump 101 to produce vaporized ammonia. The vaporizer 106 sends the vaporized ammonia to the chamber 107.

[0034] The chamber 107 is a tank that temporarily stores vaporized ammonia to be supplied to the generator 400 .

[0035] A plurality of shut-off valves 108 are disposed in the piping that connects the various devices 101 to 107 described above. The plurality of shut-off valves 108 have the function of connecting the piping when in an open state and disconnecting the piping when in a closed state. The states of the plurality of shut-off valves 108 are remotely controlled by the safety control device 10. In the example of Fig. 2, the plurality of shut-off valves 108 include shut-off valves 108a, 108b, 108c, 108d, 108e, 108f, 108g, 108h, 108i, and 108j.

[0036] The shutoff valve 108a is provided between the fuel tank 200 and the low-pressure pump 101. The shutoff valve 108b is provided between the low-pressure pump 101 and the heat exchanger 102. The shutoff valve 108c is provided between the heat exchanger 102 and the chamber 103. The shutoff valve 108d is provided between the chamber 103 and the high-pressure pump 104. The shutoff valve 108e is provided between the high-pressure pump 104 and the main engine 300. The shutoff valve 108f is provided between the chamber 103 and the heat exchanger 105. The shutoff valve 108g is provided between the heat exchanger 105 and the main engine 300. The shutoff valve 108h is provided between the low-pressure pump 101 and the carburetor 106. The shutoff valve 108i is provided between the carburetor 106 and the chamber 107. The shutoff valve 108j is provided between the chamber 107 and the generator 400.

[0037] For example, by closing the shutoff valves 108c, 108d, and 108f, it is possible to isolate the chamber 103 and the piping portion connected to the chamber 103 from the ammonia fuel supply system 100. By closing the shutoff valves 108h and 108i, it is possible to isolate the vaporizer 106 and the piping portion connected to the vaporizer 106 from the ammonia fuel supply system 100.

[0038] In addition to the above-described fuel supply piping configuration, the ammonia fuel supply system 100 is further provided with a piping configuration used during a purging process. The purging process is a process of removing (purging) ammonia in the fuel supply piping configuration using a purging substance. Examples of the piping configuration used during the purging process include a piping configuration for supplying the purging substance and a piping configuration for discharging ammonia in the piping together with the purging substance. Note that, for example, nitrogen gas is used as the purging substance. Since nitrogen is an inert gas, it is unlikely to combine with ammonia, and there is little concern about corrosion of the piping.

[0039] The piping configuration for supplying the purge material is provided with a plurality of purge material supply valves 109. By opening each purge material supply valve 109, the purge material can be supplied to a predetermined portion of the fuel supply piping. The states of the plurality of purge material supply valves 109 are remotely controlled by the safety control device 10.

[0040] The piping configuration for discharging ammonia together with the purge material is provided with a plurality of purge material discharge valves 110. By opening each purge material discharge valve 110, ammonia in a specific fuel supply piping section can be sent to an abatement device (not shown) together with the purge material supplied to that piping section. The ammonia sent to the abatement device is rendered harmless and then discharged overboard. The states of the plurality of purge material discharge valves 110 are remotely controlled by the safety control device 10.

[0041] The multiple detectors 111 have a function of detecting ammonia. The multiple detectors 111 are, for example, at least one type of sensor selected from an ammonia gas concentration measuring device, an odor sensor, a gas detection camera, a pressure sensor, etc. The multiple detectors 111 are distributed and arranged at predetermined positions in the ammonia fuel supply system chamber AFSSRM so as to be able to detect ammonia leakage from any location in the ammonia fuel supply system 100. Measurement data by the multiple detectors 111 is sent to the safety control device 10 as sensor information.

[0042] The fan 112 is configured to exhaust ammonia in the ammonia fuel supply system chamber AFSSRM to the outside of the ammonia fuel supply system chamber AFSSRM. In the event of ammonia leakage, the fan 112 functions to exhaust the leaked ammonia gas as much as possible to reduce the concentration of ammonia remaining in the ammonia fuel supply system chamber AFSSRM. By arranging a detector 111 in the intake passage of the fan 112, the accuracy of detecting leaked gas can be improved. The operating state of the fan 112 is monitored by the safety control device 10.

[0043] 1.3 Safety control device FIG. 3 is a block diagram showing an example of the hardware configuration of a safety control device for an ammonia-fueled ship according to an embodiment.

[0044] As shown in FIG. 3 , the safety control device 10 includes a control circuit 11 , a storage 12 , a communication module 13 , a user interface 14 , a drive 15 , and a storage medium 16 .

[0045] The control circuit 11 is a circuit that controls the overall components of the safety control device 10. The control circuit 11 includes a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), etc. The CPU of the control circuit 11 controls the entire safety control device 10 in accordance with a program stored in the ROM of the control circuit 11. The RAM of the control circuit 11 has a working area for the CPU of the control circuit 11. The ROM of the control circuit 11 stores programs and the like used by the safety control device 10.

[0046] The storage 12 includes, for example, a hard disk drive (HDD) or a solid state drive (SSD). The storage 12 stores information used in various processes in the safety controller 10.

[0047] The communication module 13 is a circuit used for transmitting and receiving information between the safety control device 10 and the ammonia fuel supply system 100 .

[0048] The user interface 14 is a device that controls communication between the safety control device 10 and a user. The user interface 14 includes input devices and output devices. The input devices include, for example, a touch panel and operation buttons. The output devices include, for example, a printer, a speaker, and a display.

[0049] The drive 15 is a device for reading software stored in the storage medium 16. The drive 15 includes, for example, a CD (Compact Disk) drive or a DVD (Digital Versatile Disk) drive.

[0050] The storage medium 16 is a medium that stores software electrically, magnetically, optically, mechanically, or chemically. The storage medium 16 may store a program used by the safety controller 10.

[0051] FIG. 4 is a block diagram showing an example of the functional configuration of the safety control device for the ammonia-fueled ship according to the embodiment.

[0052] 4, the CPU of the control circuit 11 loads a program stored in the ROM of the control circuit 11 or the storage medium 16 into the RAM of the control circuit 11. The CPU of the control circuit 11 then interprets and executes the program loaded into the RAM of the control circuit 11. As a result, the safety control device 10 functions as a computer including a sensor information acquisition unit 21, a leakage location estimation unit 22, a sequence selection unit 23, an AFSS control unit 24, a purge control unit 25, and an operation mode control unit 26. In addition, sequence information 31 is stored in the storage 12.

[0053] The sensor information acquisition unit 21 is a functional block that acquires, as sensor information, data measured by a plurality of detectors 111 arranged in the ammonia fuel supply system chamber AFSSRM. The sensor information acquisition unit 21 sends the acquired sensor information to the leakage point estimation unit 22.

[0054] The leakage location estimation unit 22 detects leakage of ammonia in the ammonia fuel supply system chamber AFSSRM based on the sensor information. When leakage of ammonia in the ammonia fuel supply system chamber AFSSRM is detected, the leakage location estimation unit 22 estimates the location of the leakage of ammonia in the ammonia fuel supply system 100.

[0055] Specifically, for example, the leak location estimation unit 22 detects an ammonia leak when the ammonia gas concentration, the value of the odor sensor, or the concentration measured by the gas detection camera is equal to or greater than a threshold, or when the value of the pressure sensor is equal to or less than a threshold. Furthermore, for example, the leak location estimation unit 22 may generate a concentration distribution of ammonia gas leaking in the ammonia fuel supply system chamber AFSSRM by integrally processing measurement data from the multiple detectors 111. Examples of measurement data processing methods include reverse simulation using computational fluid dynamics (CFD) calculation results. The leak location estimation unit 22 may then estimate a high-concentration region in the generated concentration distribution as the ammonia leak location. Furthermore, the leak location estimation unit 22 may further estimate the degree of leakage at the leak location (e.g., whether the leakage is severe or mild) based on the concentration distribution. Furthermore, the leak location estimation unit 22 may visualize the ammonia leakage status based on the concentration distribution.

[0056] The ammonia leakage location only needs to be narrowed down to an area that allows isolation of the leakage location and removal of residual fuel from the isolated piping portion, and does not need to be estimated at a pinpoint on the ammonia fuel supply system 100. For example, the leakage location estimation unit 22 only needs to be able to estimate the ammonia leakage location at the granularity of piping portions that are divided by a plurality of shutoff valves 108 among the piping that constitutes the ammonia fuel supply system 100.

[0057] Based on the estimated ammonia leak location, the sequence selection unit 23 selects a safety control sequence from the sequence information 31. A plurality of types of safety control sequences that differ depending on the ammonia leak location are stored in the sequence information 31. The safety control sequence includes, for example, specific procedures for shutting off the shutoff valve 108, purging, and switching the operation mode.

[0058] The AFSS control unit 24 is a functional block that controls the ammonia fuel supply system 100, including the shutoff valves 108, based on the selected safety control sequence. Specifically, during the shutoff process, the AFSS control unit 24 closes predetermined shutoff valves 108 by remote control, thereby isolating the leak location. The AFSS control unit 24 also controls the operating states of the low-pressure pump 101, the heat exchanger 102, the high-pressure pump 104, the heat exchanger 105, and the vaporizer 106 by remote control. For example, when a safety control sequence for emergency shutdown of the ammonia fuel supply system 100 is selected, the AFSS control unit 24 remotely stops all of the low-pressure pump 101, the heat exchanger 102, the high-pressure pump 104, the heat exchanger 105, and the vaporizer 106.

[0059] The purge control unit 25 is a functional block that controls the purge material supply valves 109 and the purge material discharge valves 110 based on the selected safety control sequence. Specifically, during the purging process, the purge control unit 25 opens predetermined purge material supply valves 109 and purge material discharge valves 110 by remote control, and removes ammonia remaining in the piping portions isolated by the shut-off process. Furthermore, for example, when a safety control sequence that completely removes ammonia from the ammonia fuel supply system 100 is selected, the purge control unit 25 opens all purge material supply valves 109 and purge material discharge valves 110 by remote control, and completely removes ammonia from the ammonia fuel supply system 100.

[0060] The operation mode control unit 26 is a functional block that switches the operation mode based on the selected safety control sequence. Specifically, during the switching process, the operation mode control unit 26 switches the operation mode of at least one of the main engine 300 and the generator 400 from the ammonia mode to the diesel mode.

[0061] 2. Operation Next, the operation of the ammonia-fueled ship according to the embodiment will be described.

[0062] 2.1 Flowchart FIG. 5 is a flowchart showing an example of the safety control operation in the safety control device for an ammonia-fueled ship according to the embodiment.

[0063] When the operation of the ammonia mode starts (START), the sensor information acquisition unit 21 acquires sensor information from the plurality of detectors 111 in the ammonia fuel supply system chamber AFSSRM (S1).

[0064] The leakage location estimation unit 22 estimates the location of the ammonia leakage based on the sensor information acquired in the process of S1 (S2).

[0065] The sequence selection unit 23 selects a safety control sequence to be executed from the sequence information 31 based on the location and extent of the ammonia leak estimated in the process of S2 (S3).

[0066] The AFSS control unit 24 executes shutoff processing of the shutoff valve 108 so as to remotely isolate the ammonia leakage point estimated in the processing of S2 based on the safety control sequence selected in the processing of S3 (S4). Furthermore, if the safety control sequence selected in the processing of S3 includes stopping part or all of the ammonia fuel supply system 100, the AFSS control unit 24 remotely stops the equipment to be stopped.

[0067] The purge control unit 25 executes a process of purging ammonia from the piping portion including the leak location isolated in the process of S4 (S5). Furthermore, when the safety control sequence selected in the process of S3 includes a purge process for the entire ammonia fuel supply system 100, the purge control unit 25 also executes a process of purging ammonia from the piping portion other than the leak location.

[0068] In parallel with the shut-off process of S4 and the purge process of S5, the operation mode control unit 26 executes an operation mode switching process for at least one of the main engine 300 and the generator 400 based on the safety control sequence selected in the process of S3 (S6).

[0069] After the processing of S5 and the processing of S6, the safety control operation ends (end).

[0070] 2.2 Specific Examples Specific examples of the above-mentioned safety control operations are given below.

[0071] (First Example) For example, when an ammonia leak is detected near the vaporizer 106, there is a possibility that there is a problem in the ammonia fuel supply system to the generator 400, but there is no problem in the ammonia fuel supply system to the main engine 300. However, when the level of the leak is severe, in consideration of safety, the sequence selection unit 23 may select a safety control sequence that stops the entire ammonia fuel supply system 100.

[0072] In this case, the AFSS control unit 24 closes the shutoff valves 108h and 108i to isolate the periphery of the vaporizer 106 from the ammonia fuel supply system 100. Then, the AFSS control unit 24 stops the operation of the low-pressure pump 101, the heat exchanger 102, the high-pressure pump 104, and the heat exchanger 105, as well as the vaporizer 106, to stop the entire ammonia fuel supply system 100.

[0073] Thereafter, the purge control unit 25 executes a purge process to selectively remove ammonia remaining around the vaporizer 106 isolated from the ammonia fuel supply system 100. Furthermore, when predetermined conditions are met, the AFSS control unit 24 closes the shutoff valve 108a. Thereafter, the purge control unit 25 further executes a purge process to purge ammonia from all piping portions other than those around the vaporizer 106. The predetermined conditions include the lapse of a predetermined period of time since the ammonia fuel supply system 100 was stopped, the pressure in the ammonia fuel supply system 100 becoming equal to or higher than a threshold, and the like.

[0074] In addition, the operation mode control unit 26 executes a switching process to switch the operation modes of the main engine 300 and the generator 400 to the diesel mode in parallel with the above-mentioned shutoff process and purging process.

[0075] This completes the safety control sequence for shutting down the entire ammonia fuel supply system 100.

[0076] (Second Example) Furthermore, even if an ammonia leak is detected near the vaporizer 106 as in the above specific example, if the degree of the leak is minor, the sequence selection unit 23 may select a safety control sequence that stops part of the ammonia fuel supply system 100, taking operational aspects into consideration.

[0077] In this case, the AFSS control unit 24 closes the shutoff valves 108h and 108i to isolate the periphery of the vaporizer 106 from the ammonia fuel supply system 100. Then, the AFSS control unit 24 stops the operation of the vaporizer 106, while continuing the operation of the low-pressure pump 101, the heat exchanger 102, the high-pressure pump 104, and the heat exchanger 105.

[0078] The purge control unit 25 executes a purge process to selectively remove ammonia remaining around the vaporizer 106 isolated from the ammonia fuel supply system 100 .

[0079] Furthermore, the operation mode control unit 26 maintains the operation mode of the main engine 300 in the ammonia mode while executing a switching process to switch the operation mode of the generator 400 to the diesel mode.

[0080] This completes the safety control sequence for shutting down part of the ammonia fuel supply system 100.

[0081] 3. Effects of the Embodiment According to the embodiment, the sensor information acquisition unit 21 acquires, as sensor information, the detection results of ammonia gas in the ammonia fuel supply system room AFSSRM, which is a compartment within the ammonia-fueled ship 1 in which the ammonia fuel supply system 100 is arranged. The leak location estimation unit 22 estimates the location of the ammonia leak from the ammonia fuel supply system 100 based on the detection results. The sequence selection unit 23 selects a safety control sequence for the ammonia fuel supply system 100 from the sequence information 31 based on the leakage location estimation result. The operation mode control unit 26 switches the operation mode of at least one of the main engine 300 and the generator 400 of the ammonia-fueled ship 1 from the ammonia mode to the non-ammonia mode in accordance with the selected safety control sequence. This makes it possible to stop part or all of the ammonia fuel supply system 100 while maintaining the power of the ammonia-fueled ship 1. Therefore, it is possible to investigate the leak location without affecting the operation of the ammonia-fueled ship 1.

[0082] Furthermore, the AFSS control unit 24 isolates the estimated leakage location from the ammonia fuel supply system 100 in accordance with the selected safety control sequence. The purge control unit 25 removes any ammonia remaining in the isolated leakage location in accordance with the selected safety control sequence. The AFSS control unit 24 and the purge control unit 25 perform these processes with the ammonia fuel supply system room AFSSRM closed. This allows the ammonia leakage location to be remotely shut off and the remaining fuel to be removed without personnel having to enter the ammonia fuel supply system room AFSSRM, even in the event of an ammonia leak. This improves the safety of the ammonia-fueled ship 1. Furthermore, by selectively isolating the leakage location rather than the entire ammonia fuel supply system room AFSSRM, the amount of ammonia leakage and the amount of purge can be minimized.

[0083] Furthermore, the leak location estimation unit 22 estimates the extent of the leak in addition to the location of the ammonia leak. The sequence selection unit 23 selects a safety control sequence based on the location and extent of the ammonia leak. This enables a more flexible response, such as stopping only some of the functions rather than all of them, even if a leak occurs, if the impact of the leak location on the ammonia fuel supply system 100 is limited.

[0084] 4. Modifications, etc. Various modifications can be applied to the above embodiment.

[0085] In the above embodiment, the sequence selection unit 23 selects a safety control sequence based on the location and extent of the ammonia leak. However, the present invention is not limited to this. The sequence selection unit 23 may select a safety control sequence based on various other conditions. Specific examples of the various other conditions include a power outage, the ammonia concentration in the ammonia fuel supply system chamber AFSSRM exceeding a threshold value, the fan 112 stopping, the pressure and temperature of the piping of the ammonia fuel supply system 100 exceeding a threshold value, and the emergency stop button being pressed. This makes it possible to continue operation while suppressing the risk of further ammonia leakage, even in cases other than when an ammonia leak is detected, such as an emergency.

[0086] Furthermore, in the above embodiment, the safety control device 10 automatically and remotely controls the shutoff valve 108, the purge material supply valve 109, and the purge material discharge valve 110, but this is not limiting. For example, the shutoff valve 108, the purge material supply valve 109, and the purge material discharge valve 110 may be manually remotely controlled (e.g., by pressing a button) by a person to control the open and closed states. In this case, the safety control device 10 may display the estimated leak location on a display so that a person can easily understand the situation inside the ammonia fuel supply system chamber AFSSRM. Then, a person may select a safety control sequence based on information about the estimated leak location displayed on the display and execute the subsequent shutoff process and purge process.

[0087] Furthermore, in the above embodiment, nitrogen is used as the purge substance, but the present invention is not limited to this. For example, water may be used as the purge substance. When water is used as the purge substance, the property of ammonia that easily adsorbs to water can be utilized. Therefore, ammonia remaining in the piping can be purged more quickly and reliably than when nitrogen is used.

[0088] The purging process may be performed multiple times. In this case, control may be performed such that the purging process using nitrogen is performed first, and if the ammonia concentration in the piping does not decrease to a predetermined level, the purging process using water is performed.

[0089] Furthermore, as a configuration for efficiently performing the purging process, a heat trace may be provided along the piping of the ammonia fuel supply system 100. Hot water at, for example, about 40°C is constantly flowed through the heat trace. This makes it easier to vaporize the ammonia in the piping during the purging process, and makes it possible to efficiently reduce the ammonia concentration in the piping.

[0090] Furthermore, in the above-described embodiment, the main engine 300 and the generator 400 are exemplified as equipment driven by ammonia fuel supplied from the ammonia fuel supply system 100, but this is not limiting. For example, the ammonia-fueled ship 1 may further include a boiler as equipment driven by ammonia fuel supplied from the ammonia fuel supply system 100. The boiler may be configured to be switchable between an ammonia mode and a non-ammonia mode. In this case, the safety control device 10 is configured to switch the operation mode of at least one equipment selected from the main engine 300, the generator 400, and the boiler from the ammonia mode to the non-ammonia mode in accordance with the safety control sequence.

[0091] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention.

[0092] 1...ammonia-fueled ship, 10...safety control device, 11...control circuit, 12...storage, 13...communication module, 14...user interface, 15...drive, 16...storage medium, 21...sensor information acquisition unit, 22...leak location estimation unit, 23...sequence selection unit, 24...AFSS control unit, 25...purge control unit, 26...operation mode control unit, 31...sequence information, 100...ammonia fuel supply system, 101...low-pressure pump, 102, 105...heat exchanger, 103, 107...chamber, 104...high-pressure pump, 106...vaporizer, 108...shutoff valve, 109...purge material supply valve, 110...purge material discharge valve, 111...detector, 112...fan, 200...fuel tank, 300...main engine, 400...generator.

Claims

1. A safety control device comprising: an acquisition unit that acquires detection results of ammonia gas within a compartment of an ammonia-fueled ship in which an ammonia fuel supply system is arranged; an estimation unit that estimates a leak location of ammonia from the ammonia fuel supply system based on the detection results; a selection unit that selects a safety control sequence for the ammonia fuel supply system based on the estimated leak location; and a control unit that switches the operating mode of at least one of a main engine and a generator of the ammonia-fueled ship from an ammonia mode to a non-ammonia mode in accordance with the selected safety control sequence.

2. The safety control device according to claim 1, wherein the control unit isolates the estimated leak location from the ammonia fuel supply system in accordance with the selected safety control sequence, and removes ammonia remaining in the isolated leak location.

3. The safety control device according to claim 2, wherein the control unit performs the isolating and removing while the compartment is closed from the outside.

4. The safety control device according to claim 2, wherein the control unit removes ammonia remaining in the isolated leak location with water.

5. The safety control device according to claim 1, wherein the estimation unit further estimates a degree of ammonia leakage from the ammonia fuel supply system, and the selection unit selects a safety control sequence for the ammonia fuel supply system based on the estimated degree of leakage.

6. An ammonia-fueled ship comprising: a safety control device according to any one of claims 1 to 5; the ammonia fuel supply system; the main engine; and the generator.

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