JP6326165B1 - Ship and its power system and operation method - Google Patents

Abstract

Provided are a ship, a power system, and an operation method thereof that can reduce the cost of operation while suppressing the pressure on the space due to the installation of a desulfurization device in order to suppress the discharge amount of sulfur. Power generation is performed by a main engine 3 that can be driven by a high sulfur fuel F2, a shaft generator 4 that generates power in conjunction with the driving of the main engine 3, and a low sulfur fuel F1 that has a lower sulfur content than the high sulfur fuel F2. And a desulfurization device 8 that removes sulfur from the exhaust gas G obtained by burning the high sulfur fuel F2. [Selection] Figure 2

Description

  The present invention relates to a power system for supplying energy to a ship, a ship to which the power system is applied, and a method for operating the ship.

  Generally, in addition to a main engine (main engine) for generating propulsive power, a ship has a generator for supplying electric power to equipment provided at various locations, and a boiler for generating steam when the main engine is stopped. Such a power device is provided. In such a power unit, an oil fuel such as heavy oil is used as the fuel.

  By the way, in recent years, from the viewpoint of environmental consideration, severe restrictions are being imposed on the sulfur content discharged from the power unit. A measure to clear this restriction is to use a low-sulfur fuel with a low sulfur content as the fuel, but in addition, a desulfurization unit (scrubber) that removes sulfur in the exhaust gas is installed. There is also a way to do it.

  In addition, as a document which described the technique regarding the ship which uses a low sulfur fuel, there exists the following patent document 1, etc., for example. Further, as a document describing a technique relating to a desulfurization apparatus mounted on a ship, there is the following Patent Document 2.

Japanese Patent Laying-Open No. 2015-91699 JP, 2006-168574, A

  However, the low-sulfur fuel that has undergone the desulfurization process is expensive, and if it is used for ship operation, the running cost is high. Further, when a desulfurization apparatus is installed as an alternative, the desulfurization apparatus itself occupies a large space, and if the exhaust gas of each power unit described above is to be treated without leakage by the desulfurization unit, each of the power units It is necessary to extend the exhaust pipe to the desulfurization apparatus. As a result, the piping between the power units becomes complicated, and the space in the ship is further compressed.

  In view of such circumstances, the present invention is to provide a ship, a power system, and an operation method thereof that can reduce operating costs while suppressing the pressure on the space due to the installation of a desulfurization device in order to reduce the amount of sulfur emissions. It is what.

The present invention includes a main engine that can be driven by high sulfur fuel, a shaft generator that generates electric power in conjunction with the driving of the main engine, and a main generator that generates electric power using low sulfur fuel having a lower sulfur content than high sulfur fuel. A desulfurization device that removes sulfur from the exhaust gas burned with the high sulfur fuel, and a boiler capable of burning the high sulfur fuel, driving the main engine with the high sulfur fuel and generating power with the shaft generator, A navigation mode in which the exhaust gas of the main engine is processed by the desulfurization device, and high sulfur fuel is combusted by the boiler, the exhaust gas of the boiler is processed by the desulfurization device, and the main generator is processed by low sulfur fuel. It is applied to the power system of the ship comprised so that switching to the berthing mode which drives is carried out .

  The ship power system according to the present invention is configured so that the exhaust gas of the main engine and the exhaust gas of the boiler are processed by the same desulfurization apparatus, and in the navigation mode, the exhaust flow path from the main engine to the desulfurization apparatus While the exhaust passage from the boiler to the desulfurization apparatus is shut off, and in the anchoring mode, the main engine is stopped and the exhaust flow path from the main machine to the desulfurization apparatus is shut off, while the boiler It is possible to configure so as to open the exhaust flow path extending from to the desulfurization apparatus.

  The present invention also relates to a ship to which the aforementioned ship power system is applied.

  The present invention also relates to a main machine that can be driven by high-sulfur fuel, a shaft generator that generates power in conjunction with the driving of the main machine, a boiler that can burn high-sulfur fuel, and a main machine that generates power using low-sulfur fuel. A generator, and a desulfurization device that removes sulfur from the exhaust gas of the main engine and the exhaust gas of the boiler. In the navigation mode, the main engine is driven with high sulfur fuel and the shaft generator generates power. The exhaust gas of the main engine is processed by the desulfurization device, and in the anchoring mode, the high sulfur fuel is burned by the boiler, the exhaust gas of the boiler is processed by the desulfurization device, and the low sulfur fuel is used for the combustion. The present invention relates to a ship operating method for driving a main generator.

  According to the ship of the present invention and its power system and operation method, it is possible to reduce the cost of operation while suppressing the pressure on the space due to the installation of the desulfurization device in suppressing the discharge amount of sulfur. obtain.

It is a schematic diagram which shows an example of arrangement | positioning of the power equipment etc. in the ship by implementation of this invention. It is a block diagram which shows an example of the power system of the ship by implementation of this invention. It is a schematic diagram explaining the flow of the fuel and exhaust gas in the navigation mode of the first embodiment of the present invention. It is a schematic diagram explaining the flow of the fuel and exhaust gas in the anchorage mode of the first embodiment of the present invention. It is a flowchart explaining the procedure of the transition between the berthing mode in the 1st Example of this invention, and a voyage mode. It is a block diagram which shows another example of the power system of the ship by implementation of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 to 4 show an example of a ship power system according to an embodiment of the present invention and a form of a ship to which the ship power system is applied. As shown in FIG. 1, an engine room 2 provided at the stern of a ship 1 is provided with a main engine (main engine) 3 connected with a propeller as a propulsion device, and the shaft of the main engine 3 is connected to the main engine 3. A shaft generator 4 that generates power in conjunction with the operation is connected, and electric power is supplied from the shaft generator 4 to each device (not shown) installed in the ship.

  As the generator, a plurality of main generators 5 are provided in addition to the shaft generator 4. When the shaft generator 4 is stopped or when the amount of power generated by the shaft generator 4 is insufficient, the main generator is provided. 5 is driven to supplement the power. Also, on the ship, steam is made using the heat of the exhaust gas generated in the main engine 3 and used in various places, but the heat amount of the exhaust gas discharged from the main engine 3 is insufficient for the required steam volume. At this time, a boiler 6 is installed to supplement the heat quantity.

  In the power units such as the main engine 3, the main generator 5, and the boiler 6, the fuel F stored in the fuel tank 7 provided adjacent to the engine room 2 is used. The fuel F is an oil fuel such as heavy oil, for example, but other types of fuel can be used as appropriate in accordance with the specifications of the power units. The fuel tank 7 may be provided in the engine room 2 or may be installed in a place away from the engine room 2.

  In the case of the ship 1 of the first embodiment, two kinds of fuels F having different sulfur contents are used as the fuel F, and the low sulfur fuel F1 and the high sulfur fuel F2 are used as the fuel tank 7. Are stored in the low sulfur fuel storage section 7a and the high sulfur fuel storage section 7b, respectively. As described later in detail, the main engine 3 and the boiler 6 mainly use the high sulfur fuel F2, and depending on the scene, the low sulfur fuel F1 is used. In addition, the main generator 5 uses the low sulfur fuel depending on the scene. F1 is used. A scrubber (desulfurization device) 8 for removing sulfur from the exhaust gas is installed in the exhaust passage above the engine room 2. A mechanism that pumps seawater as a solvent from a sea chest near the bottom of the ship through a pump 9, injects it into exhaust gas flowing through the exhaust passage, dissolves sulfur, and discharges seawater containing sulfur to the outside of the ship It is. Alternatively, instead of pumping up seawater as a solvent, a circulating desulfurization device 8 that circulates seawater or fresh water to which a basic substance is added in the ship may be employed (not shown). Further, when the ship 1 is a tanker or the like that loads crude oil or the like as a cargo, for example, the scrubber 8 may also have a function as an inert gas scrubber that purifies exhaust gas that is sent as an inert gas to the cargo. In that case, a pipe for guiding the exhaust gas purified by the scrubber 8 to the load is separately installed (not shown).

  The arrangement of the piping system between the above devices is schematically shown in FIG. A fuel pipe 10 for supplying fuel from the fuel tank 7 to the main engine 3 branches into a branch pipe 10a and a branch pipe 10b on the upstream side, and the branch pipes 10a and 10b are connected to a low sulfur fuel storage section 7a, Each communicates with the high sulfur fuel storage section 7b. A branching point to the branch pipes 10a and 10b in the fuel pipe 10 is provided with a three-way valve 11, and by operating the three-way valve 11, the low-sulfur fuel storage section 7a or the high-sulfur fuel storage section 7b depending on the scene. It is possible to switch so that the fuel F is supplied from either one of them to the main engine 3.

  Similarly, a fuel pipe 12 for supplying fuel from the fuel tank 7 to the boiler 6 branches into a branch pipe 12a and a branch pipe 12b on the upstream side, and the branch pipes 12a and 12b store low sulfur fuel. Each communicates with the compartment 7a or the high sulfur fuel storage compartment 7b. A three-way valve 13 is provided at a branch point of the fuel pipe 12 to the branch pipes 12a and 12b, and the supply source of the fuel F supplied to the boiler 6 is between the low sulfur fuel storage section 7a or the high sulfur fuel storage section 7b. Can be switched with.

  Here, the three-way valve 11 is used to switch the flow path between the branch pipes 10a and 10b in the fuel pipe 10, but the present invention is not limited to this, and for example, each of the branch pipes 10a and 10b includes an on-off valve. The flow path of the fuel pipe 10 can be switched by switching the opening and closing of the on-off valve. As long as the flow path of the fuel F supplied to the fuel pipe 10 can be switched between the branch pipe 10a and the branch pipe 10b, anything may be used. The same applies to the three-way valve 13 in the fuel line 12.

  The fuel F is supplied to the plurality of main generators 5 from the low sulfur fuel storage section 7 a via the fuel pipe 14. The fuel pipe 14 branches into a plurality of pipes 14 a on the downstream side, and is connected to each main generator 5.

  An exhaust passage 15 for exhaust gas discharged from the main engine 3 extends upward in the hull, and its downstream side communicates with an exhaust passage 16 in which the desulfurization device 8 is installed. The exhaust flow path 16 further branches to another exhaust flow path 17 where no desulfurization apparatus is installed on the upstream side of the desulfurization apparatus 8. That is, the downstream of the exhaust passage 15 connected to the main unit 3 branches into an exhaust passage 16 where the desulfurization device 8 is installed and an exhaust passage 17 which is not installed, and the exhaust gas discharged from the main unit 3 G is discharged from the exhaust passage 16 or the exhaust passage 17 to the upper side of the hull. An exhaust purification device (not shown) for purifying the exhaust gas G combusted with the low sulfur fuel F1 may be provided near the outlet of the exhaust passage 17.

  On / off valves 18 and 24 are respectively provided on the upstream side and the downstream side of the branch point of the exhaust channel 16 to the exhaust channel 17 so that the exhaust channel 16 can be opened and closed at any position.

  The exhaust passage 20 for the exhaust gas G discharged from the boiler 6 is connected to the exhaust passage 17 downstream. The connection position of the exhaust flow path 20 to the exhaust flow path 17 is opposite to the branch position of the exhaust flow path 17 from the exhaust flow path 16 with the on-off valve 19 interposed therebetween.

  Open / close valves 19, 25, and 26 are provided on the upstream side and the downstream side of the joining point with the exhaust passage 20 in the exhaust passage 17 and the upstream side of the joining point with the exhaust passage 17 in the exhaust passage 20, respectively. The exhaust passage 17 or the exhaust passage 20 can be opened and closed at each position.

  The exhaust gas G discharged from each main generator 5 is discharged from an exhaust passage 21 extending upward in the hull. The exhaust passage 21 is not provided with a desulfurization device, but may be equipped with an exhaust purification device (not shown) for purifying the exhaust gas G combusted with the low sulfur fuel F1.

  The operation of each device such as the main machine 3, the shaft generator 4, the main generator 5, the boiler 6, and the desulfurization device 8 is operated by control signals 3a, 4a, 5a, 6a, and 8a that are input to and output from the control device 22. Is done. Each device such as the shaft generator 4, the main generator 5, the boiler 6, and the desulfurization device 8 is provided with an individual control device (not shown), and the control signals 3 a, 4 a, 5 a, 6 a, and 8 a are controlled by the control device 22. And between the individual control devices. In addition, the control device 22 is a device for operating various devices related to the operation of the ship 1 (see FIG. 1). The three-way valves 11 and 13 and the on-off valves 18, 19, 24, 25, and 26 are also respectively It is operated by input of switching signals 11a, 13a and open / close signals 18a, 19a, 24a, 25a, 26a from the control device 22.

  Further, a concentration sensor 23 for detecting the concentration of the sulfur content in the exhaust gas G is installed downstream of the desulfurization device 8 in the exhaust flow path 16, and the concentration of the sulfur content is monitored here. When the concentration of the sulfur component detected by the concentration sensor 23 is higher than a prescribed value, a concentration signal 23a is input from the concentration sensor 23 to the individual control device provided in the desulfurization device 8, and from the individual control device. The control signal 8a indicating a state abnormality is output to the control device 22. In addition, the control device 22 monitors various state abnormalities in the desulfurization device 8 through a control signal 8a.

  Next, the operation of the first embodiment will be described.

  As described above, the ship 1 (see FIG. 1) of the first embodiment stores two types of fuel F as a low-sulfur fuel F1 and a high-sulfur fuel F2 in the fuel tank 7. It is characterized in that it is used properly.

  First, the case of navigating the high seas will be described with reference to FIG. During this time, the ship 1 (see FIG. 1) is propelled by the main engine 3 (hereinafter, this operation state is referred to as “navigation mode”). At this time, the main engine 3 is operated mainly by the high sulfur fuel F2. The three-way valve 11 is operated to supply the high sulfur fuel F2 from the high sulfur fuel storage section 7b of the fuel tank 7 to the main engine 3 downstream of the fuel pipe 10 via the branch pipe 10b. In the main engine 3, the high sulfur fuel F2 is burned, and the propeller shaft is rotated to generate a propulsive force. At the same time, the shaft generator 4 is driven in conjunction with the main engine 3, and electric power is supplied from the shaft generator 4 to various parts of the ship. Further, steam is made using the heat of the exhaust gas G discharged from the main engine 3 and sent to various places on the ship.

  During this time, the on-off valves 18 and 24 provided in the exhaust passage 16 are opened, and the on-off valve 19 of the exhaust passage 17 is closed. That is, the flow path from the exhaust flow path 15 downstream of the main engine 3 to the exhaust flow path 16 provided with the desulfurization device 8 is opened, while the flow path from the boiler 6 to the desulfurization device 8 is blocked. The exhaust gas G generated by the combustion of the high sulfur fuel F2 in the main engine 3 is discharged after the sulfur content is removed by the desulfurization device 8 in the exhaust passage 16.

  Here, during the navigation mode, the output of the main engine 3 may decrease, for example, when the ship 1 is decelerated. At that time, the amount of the exhaust gas G discharged from the main engine 3 decreases, and there may occur a situation where the amount of steam produced by the heat of the exhaust gas G is insufficient with respect to the amount of steam required in the ship. In this case, the shortage can be compensated by burning the fuel F in the boiler 6 to generate steam.

  At this time, the boiler 6 uses the low sulfur fuel F1. The three-way valve 13 is operated, and the low-sulfur fuel F1 is supplied from the low-sulfur fuel storage section 7a of the fuel tank 7 to the boiler 6 downstream of the fuel line 12 through the branch pipe 12a, as indicated by the broken arrow in FIG. Supply and burn. Here, in the navigation mode, among the on-off valves 18, 19, 24, 25, and 26 provided in the exhaust passages 16, 17, and 20, the on-off valve 19 is closed and the exhaust valves 25 and 26 are opened. The exhaust gas G generated from the boiler 6 flows from the exhaust flow path 20 to the exhaust flow path 17 as indicated by the dashed arrows in FIG. Although the exhaust passage 17 is not equipped with a desulfurization device, since the exhaust gas G generated by the combustion of the low sulfur fuel F1 originally has a low sulfur content, the amount of the exhausted sulfur can be suppressed. .

  Similarly, during the voyage mode, the power generation amount of the shaft generator 4 that is linked to the main engine 3 may decrease. In this case, as shown by the broken arrow in FIG. The low-sulfur fuel storage section 7a is supplied with the low-sulfur fuel F1 to the main generator 5 through the fuel pipe 14, and the main generator 5 is driven to generate power to compensate for the shortage of the power generation amount. At this time, the exhaust flow passage 21 downstream of the main generator 5 is not provided with a desulfurization device, but the main generator 5 uses the low sulfur fuel F1 as a fuel, so that the amount of sulfur content to be discharged is minimized. Can be suppressed.

  Next, the case where the ship is anchored at a port or the like, or cargo handling is performed will be described with reference to FIG. During this time, since the ship 1 is not propelled, the main engine 3 is stopped. On the other hand, when the main machine 3 is stopped, the shaft generator 4 linked with the main machine 3 does not operate, so during this time, the main generator 5 is activated to generate electric power, and the electric power is sent to various places on the ship. Further, since no exhaust gas is generated from the main engine 3, the boiler 6 is operated to generate steam (hereinafter, this operation state is referred to as “berthing mode”). At this time, the boiler 6 mainly burns the high sulfur fuel F2, and the main generator 5 is driven by the low sulfur fuel F1.

  The three-way valve 13 is operated to supply the high sulfur fuel F2 from the high sulfur fuel storage section 7b of the fuel tank 7 to the boiler 6 downstream of the fuel line 12 through the branch pipe 12b as shown in FIG. In the boiler 6, steam is generated by the heat generated by the combustion of the high sulfur fuel F <b> 2 and supplied to various places in the ship.

  During this time, among the on-off valves 18, 19, 24, 25, and 26 provided in the exhaust passages 16, 17, and 20, the on-off valves 18 and 25 are closed and the on-off valves 19, 24, and 26 are opened. That is, the flow path from the exhaust flow path 20 downstream of the boiler 6 to the exhaust flow path 16 through the exhaust flow path 17 is opened, while the flow path from the main engine 3 to the desulfurization device 8 is blocked. The exhaust gas G generated by the combustion of the high sulfur fuel F2 in the boiler 6 is discharged after the sulfur content is removed by the desulfurization device 8 in the exhaust passage 16. On the other hand, since the exhaust gas G discharged from the main generator 5 driven by the low-sulfur fuel F1 has a low sulfur content, even in this anchoring mode, the amount of sulfur discharged should be minimized. Can do.

  Thus, in the first embodiment, in the navigation mode, the main engine 3 generates energy by burning the high sulfur fuel F2 to obtain the propulsive force of the ship 1, and the shaft generator 4 linked to the main engine 3 is used. While generating electricity, in the berthing mode, the boiler 6 burns the high sulfur fuel F2, and the main generator 5 is driven by the low sulfur fuel F1.

  That is, among the power units (main machine 3, shaft generator 4, main generator 5, boiler 6) provided in the ship 1, the shaft generator 4 that generates power in the voyage mode is linked to the main machine 3, Since the main generator 5 uses the low sulfur fuel F1, only the main machine 3 and the boiler 6 require the use of the desulfurization device 8 for the exhaust gas G. And by processing the exhaust gas G discharged from the main engine 3 with the combustion of the high sulfur fuel F2 and the exhaust gas G discharged with the combustion of the high sulfur fuel F2 from the boiler 6 by the same desulfurization device 8, The space related to the installation of the desulfurization apparatus 8 is reduced.

  In other words, if the main generator 5 is configured to be driven by the high sulfur fuel F2 or the shaft generator 4 is configured to be driven independently of the main engine 3 by the high sulfur fuel F2, In addition to the boiler 3 and the boiler 6, the exhaust gas discharged from the shaft generator 4 and the main generator 5 also needs to be processed by the desulfurization device 8. In that case, it is necessary to separately install an exhaust passage for guiding the exhaust gas from the shaft generator 4 or the main generator 5 to the desulfurization device 8, and the flow passage configuration of the exhaust passage and the positional relationship between the exhaust ducts are complicated. The space in the ship 1 is compressed. Therefore, as in the first embodiment, the shaft generator 4 is interlocked with the main engine 3, the high sulfur fuel F2 is used by the shaft generator 4 and the boiler 6, and the main generator 5 is driven by the low sulfur fuel F1. By doing so, it is possible to avoid complication of the flow path configuration of the piping to suppress the compression of the space, and to reduce the cost for installing the desulfurization device 8 and the piping.

  Here, since the main generator 5 exclusively uses the low-sulfur fuel F1, it cannot be denied that the running cost is higher than when the high-sulfur fuel F2 is used. Since a certain main engine 3 mainly uses high sulfur fuel F2, the amount of low sulfur fuel F1 used can be kept to a minimum. Moreover, since the generator corresponding to the low sulfur fuel F1 is generally cheaper than the generator of the high sulfur fuel F2 specification, the initial cost for installing the main generator 5 can be reduced when the ship 1 is constructed. . Further, since the main generator 5 is stopped during the voyage mode, the maintenance labor that occurs according to the accumulated operation time can be minimized, and the cost for the maintenance can be suppressed.

  Further, in the first embodiment, the desulfurization device 8 is disposed between the main engine 3 and the boiler 6 by shifting the timing of use of the high sulfur fuel F2 in the main engine 3 and the timing of use of the high sulfur fuel F2 in the boiler 6. Sharing is possible. That is, the back pressure of the exhaust gas G generated from the main engine 3 as an engine is generally significantly higher than the back pressure of the exhaust gas G of the boiler 6. For this reason, if the main sulfur 3 and the boiler 6 simultaneously burn the high sulfur fuel F2 and attempt to guide the exhaust gas G to the desulfurization device 8, the back pressure of the exhaust gas G that can be allowed in the exhaust flow path 15; Unlike the back pressure of the exhaust gas G that can be tolerated in the exhaust flow path 20, the back pressure of the exhaust gas G is greatly different. As a result, a situation in which the boiler 6 misfires may occur. Therefore, in the first embodiment, in the navigation mode as described above, the high sulfur fuel F2 is combusted in the main engine 3 and the exhaust gas G is guided to the desulfurization device 8, while the low sulfur fuel is used when the boiler 6 is used. In the anchoring mode, the main engine 3 is stopped and the exhaust passage is switched, and the high sulfur fuel F2 is combusted by the boiler 6 so that the exhaust gas G is guided to the desulfurization device 8. By doing so, the above-mentioned problems caused by the back pressure difference of the exhaust gas G can be avoided, and the exhaust gas G of the main engine 3 and the exhaust gas G of the boiler 6 can be processed by the single desulfurization device 8. It is.

  Further, a procedure for shifting from the anchoring mode to the navigation mode and from the navigation mode to the anchoring mode will be described with reference to the flowchart of FIG. In the anchoring mode in which the ship 1 (see FIG. 1) is anchored at a port or the like, or the cargo handling is being performed, the main engine 3 is stopped as described above, and the shaft generator 4 linked to the main engine 3 is also stopped. Yes. The main generator 5 is operated to supply electric power to the ship instead of the shaft generator 4, and the boiler 6 is also operated to generate steam instead of the main engine 3. The main generator 5 is driven by the low-sulfur fuel F1, the high-sulfur fuel F2 is supplied to the boiler 6, and the exhaust gas G of the boiler 6 is guided to the desulfurization device 8 and processed (see FIG. 4, step S1). ).

  When the berthing mode is terminated and the mode is shifted to the voyage mode, the ship is first maneuvered such as turning the ship 1 (see FIG. 1) in a harbor or the like. At this time, the main engine 3 is started as step S2 to generate a propulsive force (see FIG. 2). However, at this stage, the boat speed is slow and the speed of the main engine 3 is low. Therefore, the shaft generator 4 is stopped and the operation of the main generator 5 is continued. Steam production is supplemented by operation of the boiler 6.

  At this time, high sulfur fuel F2 is supplied to the main engine 3 (see FIG. 2). The boiler 6 is operated by switching the three-way valve 13 and using the low sulfur fuel F1. Accordingly, the on-off valves 18, 19, 24, 25, and 26 are switched to open the on-off valves 18, 24, 25, and 26, and the on-off valve 19 is closed. The exhaust gas G of the main machine 3 is processed by the desulfurization device 8, and the exhaust gas G of the boiler 6 is discharged without passing through the desulfurization device 8.

  When leaving the port or the like and the rotation speed of the main machine 3 can be sufficiently increased, the shaft generator 4 linked to the main machine 3 is started and the main generator 5 is stopped as step S3. Thus, the operation state shifts to the navigation mode, and as described above, the main engine 3 is operated by the high sulfur fuel F2, the shaft generator 4 is driven in conjunction with the main engine 3, and the main generator 5 and the boiler 6 are in principle. Stop. When the main generator 5 and the boiler 6 are operated, the operation is performed with the low sulfur fuel F1. In the desulfurization apparatus 8, the exhaust gas G of the main machine 3 is processed (refer FIG. 3, step S4).

  When entering the harbor or the like from the voyage mode and shifting to the anchoring mode again, the ship speed decreases and the rotational speed of the main engine 3 decreases. Therefore, in step S5, the shaft generator 4 is stopped, and the main generator is used instead. 5 is started. Further, as step S6, the main machine 3 is stopped and the boiler 6 is operated. The boiler 6 is supplied with high-sulfur fuel F2, and the desulfurization device 8 switches the on-off valves 18, 19, 24, 25, and 26 so as to process the exhaust gas G of the boiler 6 and shifts to the anchoring mode (FIG. 4). See step S1).

  Furthermore, depending on conditions, during the navigation mode as described above (see step S4 in FIG. 5 and FIG. 3), it may be desired to stop the combustion of the high sulfur fuel F2 in the main engine 3. For example, some sea areas where regulations on pollutant emissions are particularly strict. When entering such a sea area, the three-way valve 11 may be switched to supply the low-sulfur fuel F1 to the main engine 3. During this time, the boiler 6 and the desulfurization device 8 can be stopped, and the low sulfur fuel F1 can be burned in the boiler 6 if necessary. At that time, the on-off valves 18, 19, 24, 25, and 26 are switched, the exhaust gas G from the main engine 3 is discharged from the exhaust passage 16 via the desulfurization device 8, and the exhaust gas G from the boiler 6 is What is necessary is just to discharge from the exhaust flow paths 20 and 17. Note that some desulfurization apparatuses 8 can pass the exhaust gas G as it is without purifying the exhaust gas G during stoppage. Therefore, if such a desulfurization apparatus 8 is installed, low sulfur can be obtained. There is no problem in discharging the exhaust gas G obtained by burning the fuel F1 through the stopped desulfurization device 8.

  When the sea area is removed, the three-way valve 11 is switched again to supply the high-sulfur fuel F2 to the main engine 3 and the exhaust gas G is processed by the desulfurizer 8.

  Furthermore, various problems may occur in the power system as described above during the voyage. For example, the performance of the desulfurization device 8 is deteriorated for some reason, or the amount of exhaust gas G exceeding the purification performance of the exhaust gas G by the desulfurization device 8 is exhausted from the main engine 3. It is assumed that the concentration of the sulfur content in the exhaust gas G increases.

  In this case, the increase in the sulfur content is detected by the concentration sensor 23, notified to the control device 22 via the individual control device of the desulfurization device 8, and detected as an abnormality. When the sulfur concentration in the exhaust gas G is high, possible main causes are a decrease in the function of the desulfurization device 8 as described above or an excessive amount of the exhaust gas G discharged from the main engine 3. In the control device 22, the control signal 4 a is input to the individual control device provided in the shaft generator 4 so as to reduce the power generation amount of the shaft generator 4, or the load on the main unit 3 is reduced. A control signal 3a is input to the individual control device provided in the main machine 3 (both operations may be performed). The reduced power generation amount is covered by starting the main generator 5.

  When the sulfur concentration downstream of the desulfurization device 8 is particularly high, the desulfurization device 8 is stopped and the desulfurization device 8 is inspected together with the reduction in the power generation amount of the shaft generator 4 and the load on the main engine 3 described above. . At this time, the three-way valve 11 is switched, low sulfur fuel F1 is supplied to the main engine 3, and the open / close valves 18, 19, 24, 25, 26 are switched, and the exhaust gas G of the main engine 3 is discharged from the exhaust passage 17. Discharge. And when abnormality is discovered in the desulfurization apparatus 8, it sails, driving the main machine 3 with the low sulfur fuel F1 in the state which stopped this desulfurization apparatus 8. FIG.

  Note that the above-described operation method (operation mode switching or the like) is merely an example, and various procedures and methods other than those described above may be employed when actually operating the ship 1. For example, the timing for executing the operation in the voyage mode is not limited to the time when navigating on the high seas, and the ship 1 can be operated in the voyage mode in a timely manner according to the situation and conditions. Similarly, the ship 1 can be operated in a berthing mode as necessary, for example, other than during berthing in a harbor or during cargo handling.

  As described above, in the first embodiment, the main engine 3 that can be driven by the high sulfur fuel F2, the shaft generator 4 that generates power in conjunction with the driving of the main engine 3, and the high sulfur fuel F2 are burned. A possible boiler 6, a main generator 5 that generates power using a low-sulfur fuel F <b> 1 having a lower sulfur content than the high-sulfur fuel F <b> 2, and a desulfurizer 8 that removes sulfur from the exhaust gas G that burns the high-sulfur fuel F <b> 2. It has. While the shaft generator 4 is linked to the main engine 3, the high sulfur fuel F2 is used by the shaft generator 4, and the main generator 5 is driven by the low sulfur fuel F1, thereby avoiding complicated piping flow path configuration. Thus, the pressure on the space can be suppressed, and the cost for installing the desulfurization device 8 and piping can be reduced. In addition, the initial cost and maintenance cost related to the installation of the main generator 5 can be reduced.

  The first embodiment also includes a boiler 6 capable of burning high-sulfur fuel F2, drives the main engine 3 with the high-sulfur fuel F2, generates power with the shaft generator 4, and desulfurizes the exhaust gas G of the main engine 3. The navigation mode to be processed by the apparatus 8 and the high sulfur fuel F2 are combusted by the boiler 6, the exhaust gas G of the boiler 6 is processed by the desulfurization apparatus 8, and the main generator 5 is driven by the low sulfur fuel F1. Since the berthing mode can be switched, the timing of using the high-sulfur fuel F2 in the main engine 3 and the timing of using the high-sulfur fuel F2 in the boiler 6 are shifted so that the main engine 3 and the boiler 6 can be switched. When the desulfurization device 8 is shared, problems due to the back pressure difference of the exhaust gas G can be avoided.

  Further, in the first embodiment, the exhaust gas G of the main engine 3 and the exhaust gas G of the boiler 6 are processed by the same desulfurization device 8, and the main engine 3 reaches the desulfurization device 8 in the navigation mode. While the exhaust passages 15 and 16 are opened, the exhaust passage 17 from the boiler 6 to the desulfurization device 8 is shut off, and in the anchoring mode, the main unit 3 is stopped and the exhaust passage from the main unit 3 to the desulfurization device 8 Since the exhaust passages 20 and 17 extending from the boiler 6 to the desulfurization device are opened while the desulfurization device 8 is shared between the main engine 3 and the boiler 6, Problems caused by the back pressure difference can be avoided more reliably.

  Therefore, according to the first embodiment, the cost for operation can be reduced while suppressing the pressure on the space due to the installation of the desulfurization device when suppressing the discharge amount of the sulfur content.

  FIG. 6 shows another example of a ship power system according to an embodiment of the present invention. In the second embodiment, the desulfurization device 8 is not shared by the main machine 3 and the boiler 6, and the exhaust gas G of the main machine 3 is always led to the desulfurization device 8, while the exhaust gas G of the boiler 6 is always desulfurized. The power system is configured to discharge without passing through.

  That is, the point that the exhaust passage 15 connected to the main engine 3 communicates with the exhaust passage 16 provided with the desulfurization device 8 downstream is the same as the first embodiment (see FIG. 2). In the case of the second embodiment, the exhaust passage 17 through which the exhaust gas G from the main engine 3 bypasses the desulfurization device 8 is not provided, and the exhaust passage 20 connected to the boiler 6 It connects to the outside of the ship without being connected to the road 16. Along with this, the exhaust passages 17 and 20 are not provided with an on-off valve or the like for switching the passages.

  In this way, when the high sulfur fuel F2 is burned in the main engine 3, the exhaust gas G is guided to the exhaust passage 16 and processed by the desulfurization device 8. On the other hand, when the low sulfur fuel F1 is burned in the main engine 3, desulfurization is performed. The apparatus 8 is stopped and the exhaust gas G is discharged from the exhaust passage 16 without being processed by the desulfurization apparatus 8, and only the low-sulfur fuel F1 is burned in the boiler 6, and the exhaust gas G is discharged into the exhaust passage 20 It comes to discharge from.

  With such a configuration, the configuration of the piping is not complicated because the main engine 3 and the boiler 6 do not share the exhaust flow path, so that an increase in cost for installing the piping and pressure on the space can be kept small. Further, since the exhaust passages 15 and 16 through which the exhaust gas G of the main engine 3 flows and the exhaust passage 20 through which the exhaust gas G of the boiler 6 flows are independent from each other, the back of the exhaust gas G as described above. There is no problem of pressure difference.

  Since other configurations and operational effects are the same as those in the first embodiment (see FIG. 2), description thereof will be omitted. However, in the second embodiment, a desulfurization unit is installed to reduce the amount of sulfur emissions. The cost of driving can be reduced while suppressing the pressure on the space.

  The ship of the present invention and its power system and operation method are not limited to the above-described embodiments, and various changes can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Ship 3 Main machine 4 Shaft generator 5 Main generator 6 Boiler 8 Desulfurization apparatus 15 Exhaust flow path 16 Exhaust flow path 17 Exhaust flow path F1 Fuel (low sulfur fuel)
F2 fuel (high sulfur fuel)
G exhaust gas

Claims (4)

A main engine that can be driven by high-sulfur fuel;
A shaft generator that generates power in conjunction with the drive of the main engine;
A main generator that generates power with a low sulfur fuel having a lower sulfur content than a high sulfur fuel;
A desulfurizer that removes sulfur from the exhaust gas combusted with high sulfur fuel ;
A boiler capable of burning high sulfur fuel ,
A navigation mode in which the main engine is driven with high-sulfur fuel and power is generated by the shaft generator, and the exhaust gas of the main engine is processed by the desulfurization device;
A berthing mode in which high sulfur fuel is combusted in the boiler, exhaust gas of the boiler is processed in the desulfurization device, and the main generator is driven with low sulfur fuel;
A ship power system that is configured to be switchable . The exhaust gas of the main engine and the exhaust gas of the boiler are configured to be processed by the same desulfurization device,
In the navigation mode, the exhaust passage from the main engine to the desulfurizer is opened, while the exhaust passage from the boiler to the desulfurizer is shut off,
In the anchoring mode, the main engine is stopped and an exhaust flow path from the main machine to the desulfurization apparatus is shut off, while an exhaust flow path from the boiler to the desulfurization apparatus is opened. 2. A power system for a ship according to 1 . A ship to which the ship power system according to claim 1 or 2 is applied. A main engine that can be driven by high sulfur fuel
A shaft generator that generates power in conjunction with the drive of the main engine;
A boiler capable of burning high sulfur fuel;
A main generator that generates electricity with a low sulfur fuel having a lower sulfur content than a high sulfur fuel;
A desulfurizer that removes sulfur from the exhaust gas of the main engine and the exhaust gas of the boiler,
In the voyage mode, the main engine is driven with high sulfur fuel and the shaft generator is used to generate power, and the exhaust gas of the main engine is processed by the desulfurizer,
In the berthing mode, a high sulfur fuel is burned by the boiler, the exhaust gas of the boiler is processed by the desulfurization device, and the main generator is driven by the low sulfur fuel.

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