JP7344019B2 - Marine internal combustion engine - Google Patents

Description

The technology disclosed herein relates to a marine internal combustion engine.

For example, Patent Document 1 discloses a drain tank (fuel drain recovery tank) for recovering fuel drain discharged from an internal combustion engine. The drain tank disclosed in this document is connected to an internal combustion engine via a three-way switching valve.

Japanese Unexamined Patent Publication No. 6-10785

By the way, the drain tank as described in Patent Document 1 is connected to a fuel injection valve via a tubular member (so-called fuel drain pipe). If the configuration is such that one cylinder has multiple fuel injection valves, such as a marine internal combustion engine, a funnel-shaped hopper can be installed in the middle of the fuel drain pipe to drain the fuel from each fuel injection valve. It is conceivable to collect the fuel drains. Such hoppers were usually configured to be open to the atmosphere in order to visually check the discharge status of the fuel drain.

However, when using a fuel such as ammonia that evaporates at room temperature and pressure, using a hopper that is open to the atmosphere may cause the vaporized fuel to diffuse into the engine room.

The technology disclosed herein has been developed in view of this point, and its purpose is to suppress the diffusion of fuel into the engine room.

Specifically, the present disclosure relates to marine internal combustion engines. This marine internal combustion engine includes a plurality of fuel injection valves that are provided in a cylinder and inject volatile fuel, a drain tank that stores fuel drain discharged from the plurality of fuel injection valves, and a plurality of fuel injection valves that inject volatile fuel. a fuel drain pipe that connects the valve and the drain tank; and a merging section that is provided in the middle of the fuel drain pipe and where fuel drain discharged from each of the plurality of fuel injection valves joins, The section is constructed in an airtight manner.

Here, "the fuel is volatile" refers to the fact that at least a portion of the fuel can evaporate at normal temperature and pressure. Note that "normal temperature" refers to a temperature within the range of 20±15° C. as specified by Japanese Industrial Standards (JIS). Moreover, "normal pressure" refers to a pressure near standard atmospheric pressure (1013.25 hPa).

According to the above configuration, the fuel drain discharged from each of the plurality of fuel injection valves joins together at the joining part. By configuring this merging portion in an airtight manner, it is possible to suppress diffusion of fuel into the engine room in which the marine internal combustion engine is installed.

Furthermore, the merging section may include a hopper for draining fuel.

This configuration is advantageous in suppressing the diffusion of fuel into the engine room.

Further, the volatile fuel may be water-soluble, and water may be stored in the drain tank in advance.

Here, "the fuel is water-soluble" means that at least a portion of the fuel can be dissolved in water at normal temperature and pressure.

According to the above configuration, the fuel drain (particularly the fuel drain containing water-soluble fuel) supplied to the drain tank via the fuel drain pipe dissolves in the water stored in the drain tank. . Thereby, diffusion of fuel into the air can be suppressed.

Further, the plurality of fuel injection valves inject at least a first fuel made of diesel fuel and a second fuel made of the volatile fuel in a layered manner, and the drain tank includes an oil-water separation tank. It may be connected.

According to this configuration, a mixture of fuel drain and water can be separated into water in which the second fuel is dissolved and an oil component made of the first fuel. Thereby, the first fuel and the second fuel can be reused separately, or at least one can be incinerated.

Further, the marine internal combustion engine may include a boiler that incinerates the volatile fuel, and a first vaporized fuel supply pipe that connects the boiler and the drain tank.

According to this configuration, vaporized fuel (volatile fuel) out of the fuel drain supplied to the drain tank can be supplied to the boiler. Thereby, the fuel can be incinerated.

In addition, by removing gas from the drain tank, the pressure inside the tank can be kept low. This is effective in smoothly guiding fuel drain to the drain tank.

Further, the marine internal combustion engine includes a compressor that compresses air and a turbine that drives the compressor, and the compressor and the drain tank are connected to a supercharger that supplies the air compressed by the compressor to the cylinder. The second vaporized fuel supply pipe may include and.

According to this configuration, vaporized fuel (volatile fuel) out of the fuel drain supplied to the drain tank can be supplied to the compressor. Thereby, fuel can be supplied to the cylinder via the supercharger and reused for combustion within the cylinder.

In addition, by removing gas from the drain tank, the pressure inside the tank can be kept low. This is effective in smoothly guiding fuel drain to the drain tank.

In addition, since fuel drain is basically discharged from the fuel injection valve while the marine internal combustion engine is operating, during that time, fuel is discharged from the cylinder via the supercharger ( By supplying volatile fuel), the fuel can be reused in a timely manner.

As explained above, according to the marine internal combustion engine, diffusion of fuel into the engine compartment can be suppressed.

FIG. 1 is a schematic diagram illustrating the configuration of a marine internal combustion engine. FIG. 2 is a schematic diagram illustrating a drain system. FIG. 3 is a schematic diagram showing a modification of the drain system. FIG. 4 is a schematic diagram illustrating a drain system according to the second embodiment. FIG. 5 is a schematic diagram showing a modification of the drain system according to the second embodiment.

Embodiments of the present disclosure will be described below based on the drawings. Note that the following explanation is an example. In addition, in the following description, the first and second embodiments and modifications of each embodiment will be described, but elements that are the same or similar in each embodiment and modification are denoted by common reference numerals. and do not repeat the explanation.

<First embodiment>
FIG. 1 is a schematic diagram illustrating the configuration of a marine internal combustion engine 1, and FIG. 2 is a diagram illustrating a drain system 100. Hereinafter, the marine internal combustion engine 1 will be simply referred to as "engine 1."

The engine 1 is an in-line multi-cylinder diesel engine including a plurality of cylinders 16. This engine 1 is configured as a two-stroke, one-cycle engine that employs a uniflow scavenging system, and is installed on large ships such as tankers, container ships, and car carriers.

An engine 1 mounted on a ship is used as a main engine for propelling the ship. That is, the output shaft of the engine 1 is connected to a propeller (not shown) of a ship via a propeller shaft (not shown). When the engine 1 is operated, its output is transmitted to the propeller to propel the ship.

In particular, the engine 1 according to the present embodiment is configured as a so-called crosshead type internal combustion engine in order to realize a long stroke. That is, in this engine 1, a piston rod 22 that supports a piston 21 from below and a connecting rod 24 that is connected to a crankshaft 23 are connected by a crosshead 25.

(1) Main configuration The main parts of the engine 1 will be explained below.

As shown in FIG. 1, the engine 1 includes a base plate 11 located below, a frame 12 provided on the base plate 11, and a cylinder jacket 13 provided on the frame 12. The base plate 11, the frame 12, and the cylinder jacket 13 are fastened together by a plurality of tie bolts and nuts that extend in the vertical direction. The engine 1 also includes a cylinder 16 provided within a cylinder jacket 13, a piston 21 provided within the cylinder 16, and an output shaft (for example, a crankshaft 23) that rotates in conjunction with the reciprocating motion of the piston 21. There is.

The base plate 11 constitutes the crankcase of the engine 1, and accommodates a crankshaft 23 and a bearing 26 that rotatably supports the crankshaft 23. A lower end portion of a connecting rod 24 is connected to the crankshaft 23 via a crank 27 .

The frame 12 accommodates a pair of guide plates 28, a connecting rod 24, and a crosshead 25. Among these, the pair of guide plates 28 are made of a pair of plate-like members provided along the piston axial direction, and are arranged at intervals in the width direction of the engine 1 (in the left-right direction in the paper of FIG. 1). The connecting rod 24 is disposed between a pair of guide plates 28, with its lower end connected to the crankshaft 23. The upper end of the connecting rod 24 is connected to the lower end of the piston rod 22 via a crosshead 25.

Specifically, the crosshead 25 is disposed between a pair of guide plates 28 and slides along each guide plate 28 in the vertical direction. That is, the pair of guide plates 28 are configured to guide the sliding movement of the crosshead 25. The crosshead 25 is connected to the piston rod 22 and the connecting rod 24 via a crosshead pin 29. The crosshead pin 29 is connected to the piston rod 22 so as to move up and down integrally with the piston rod 22, while the crosshead pin 29 is connected to the connecting rod 24 to rotate the connecting rod 24 using the upper end of the connecting rod 24 as a fulcrum. are connected like this.

The cylinder jacket 13 is provided with a cylinder liner 14 as an inner cylinder. The piston 21 described above is arranged inside the cylinder liner 14. This piston 21 reciprocates in the vertical direction along the inner wall of the cylinder liner 14. Further, a cylinder cover 15 is fixed to the upper part of the cylinder liner 14. The cylinder cover 15 and the cylinder liner 14 constitute a cylinder 16.

Further, the cylinder cover 15 is provided with an exhaust valve 18 that is operated by a valve operating device (not shown). The exhaust valve 18 defines a combustion chamber 17 together with a cylinder 16 made up of a cylinder liner 14 and a cylinder cover 15, and the top surface of a piston 21. The exhaust valve 18 opens and closes the space between the combustion chamber 17 and the exhaust pipe 19. The exhaust pipe 19 has an exhaust port (not shown) communicating with the combustion chamber 17, and the exhaust valve 18 is configured to open and close the exhaust port.

Further, the cylinder cover 15 defines a ceiling surface (not shown) of the combustion chamber 17. A plurality of fuel injection valves 30 are provided on this ceiling surface. In this first embodiment, each cylinder 16 is provided with two fuel injection valves 30 (see FIG. 2). Hereinafter, one of the two fuel injection valves 30 may be referred to as a first injection valve 30a, and the other may be referred to as a second injection valve 30b. Each fuel injection valve 30 can inject at least the second fuel made of volatile fuel.

Here, as the second fuel, for example, a fuel consisting of ammonia, methanol, ethanol, gasoline, etc. can be used. The fuel injection valve 30 according to the first embodiment injects fuel made of ammonia as the second fuel. In particular, when ammonia is used as the second fuel, the second fuel has water solubility in addition to volatility.

The engine 1 also includes a fuel pump 41 that pumps a first fuel such as diesel fuel to the fuel injection valve 30, and an injection pump 51 that injects a second fuel such as ammonia into a path through which the first fuel is pumped. It is equipped with.

With this configuration, the fuel injection valve 30 can inject the second fuel injected by the injection pump 51 into the combustion chamber 17 in addition to the first fuel pumped from the fuel pump 41 (see FIG. (See F1 in 2). For example, the fuel injection valve 30 supplies diesel fuel and ammonia to the combustion chamber 17 to cause combustion within the combustion chamber 17 . This combustion causes the piston 21 to reciprocate in the vertical direction. At this time, when the exhaust valve 18 is operated to open the combustion chamber 17, exhaust gas generated by combustion is pushed out to the exhaust pipe 19, and gas is introduced into the combustion chamber 17 from a scavenging port (not shown).

Further, when the piston 21 reciprocates due to combustion, the piston rod 22 reciprocates in the vertical direction together with the piston 21. As a result, the crosshead 25 connected to the piston rod 22 reciprocates in the vertical direction. The crosshead 25 is configured to allow the connecting rod 24 to rotate, and the connecting rod 24 is rotated using the connecting portion with the crosshead 25 as a fulcrum. Then, the crank 27 connected to the lower end of the connecting rod 24 makes a crank movement, and the crankshaft 23 rotates in accordance with the crank movement. In this way, the crankshaft 23 converts the reciprocating motion of the piston 21 into rotational motion, and rotates the propeller of the ship together with the propeller shaft. This propels the ship.

Here, at least a portion of the ammonia supplied to the fuel injection valve 30 is discharged from the fuel injection valve 30 as a fuel drain. The engine 1 is equipped with a drain system 100 for recovering such fuel drain.

(2) Configuration related to drain system The configuration related to the drain system 100 will be described below.

As illustrated in FIG. 2, the drain system 100 includes, as main components, a drain tank 70 that stores fuel drain discharged from a plurality of fuel injection valves 30, and a plurality of fuel injection valves 30 and a drain tank 70. A connecting fuel drain pipe 60 is provided. A merging portion 62 is provided in the middle of the fuel drain pipe 60, where the fuel drain discharged from each of the plurality of fuel injection valves 30 joins.

Specifically, the fuel drain pipe 60 includes a first branch pipe 61a connected to the first injection valve 30a, a second branch pipe 61b connected to the second injection valve 30b, and a first branch pipe 61a and a second branch pipe 61a connected to the second injection valve 30b. It has a merging section 62 for merging the branch pipes 61b, and an engine-side relay pipe 63 connected to this merging section 62.

Note that one first branch pipe 61a, one second branch pipe 61b, one merging portion 62, and one engine-side relay pipe 63 are provided for each cylinder 16. Therefore, for example, in the case of a four-cylinder engine 1, four of these members will be provided. In FIG. 2, the first branch pipe 61a, the second branch pipe 61b, and the merging portion 62 are shown for only one cylinder 16, and the engine-side relay pipe 63 is shown for four cylinders 16. The four engine-side relay pipes 63 join together at a common pipe 64 and are connected to a drain tank 70 via a tank-side relay pipe 65.

Here, the merging section 62 consists of a hopper for fuel drain, has a predetermined volume, and is formed in a funnel shape. This merging portion 62 is configured to be airtight.

Specifically, the first and second branch pipes 61a and 61b are connected to the merging portion 62 via a biting joint 66. By doing so, the connecting portion between the first branch pipe 61a and the merging portion 62 and the connecting portion between the second branch pipe 61b and the merging portion 62 are both hermetically sealed.

Similarly, the engine-side relay pipe 63 is connected to the merging portion 62 via a biting joint 66. By doing so, the connecting portion between the engine-side relay pipe 63 and the merging portion 62 is also hermetically sealed.

In this way, by connecting the first branch pipe 61a, the second branch pipe 61b, and the engine-side relay pipe 63 to the confluence section 62 in an airtight manner, the confluence section 62 can be constructed in an airtight manner. I can do it.

Further, in the example shown in FIG. 2, the drain tank 70 has a tank main body 71 connected to a tank-side relay pipe 65 in the fuel drain pipe 60. The tank body 71 can store fuel drain supplied from the fuel drain pipe 60.

The drain system 100 further includes an incineration system 80 that is connected to the drain tank 70 and incinerates ammonia as the second fuel. Specifically, the incineration system 80 includes a boiler 81 that incinerates ammonia as a second fuel, a first vaporized fuel supply pipe 82 that connects the boiler 81 and the tank body 71, and a first vaporized fuel supply pipe 82. It has a first on-off valve 83 that opens and closes.

Of these, the first vaporized fuel supply pipe 82 opens near the ceiling of the tank body 71 and sends ammonia, which has been volatilized and turned into gas, out of the ammonia supplied into the tank body 71 to the boiler 81. be able to. Ammonia sent to the boiler 81 is incinerated in the boiler 81.

Further, the first on-off valve 83 is opened and closed according to the internal pressure of the tank body 71. Specifically, when the internal pressure of the tank body 71 exceeds a predetermined value, the first on-off valve 83 is opened. By doing so, vaporized ammonia can be properly discharged.

As described above, according to the first embodiment, the fuel drain discharged from the first injection valve 30a and the second injection valve 30b join together at the joining part 62. By configuring the merging portion 62 in an airtight manner, it is possible to suppress the diffusion of fuel into the engine room in which the engine 1 is installed.

Further, as shown in FIG. 2, vaporized ammonia out of the fuel drain supplied to the tank body 71 of the drain tank 70 can be supplied to the boiler 81. Thereby, the second fuel made of ammonia can be incinerated.

In addition, by removing gas from the drain tank 70, the pressure inside the tank body 71 can be kept low. This is effective in smoothly guiding the fuel drain to the drain tank 70.

-Modified example of the first embodiment-
FIG. 3 is a schematic diagram showing a modification of the drain system 100.

Although the first embodiment described the configuration in which the incineration system 80 was connected to the drain tank 70, the present disclosure is not limited to this configuration. For example, as shown in FIG. 3, a supercharging system 90 may be connected to the drain tank 70.

Specifically, the drain system 100 according to the modification of the first embodiment includes a supercharging system 90 configured to supercharge outside air when the engine 1 is operated. The supercharging system 90 illustrated in FIG. 3 includes a compressor 92 that compresses air (especially outside air taken in from the outside) and a turbine 93 that drives the compressor 92. It has a supercharger 91 to supply, a second vaporized fuel supply pipe 94 that connects the compressor 92 and the tank body 71, and a second on-off valve 95 that opens and closes the second vaporized fuel supply pipe 94. .

Of these, the second vaporized fuel supply pipe 94 opens near the ceiling of the tank body 71 and connects the tank body 71 and the compressor 92 (specifically, the silencer in the compressor 92) to each other. ing. This second vaporized fuel supply pipe 94 can send ammonia, which has been volatilized and turned into a gas, out of the ammonia supplied into the tank body 71 to the compressor 92 . The ammonia sent to the compressor 92 is compressed in the compressor 92 together with air (outside air) introduced from the outside, and is sent into the cylinder 16.

Further, the second on-off valve 95 is kept open at least when the engine 1 is operating. By doing so, the tank body 71 and the compressor 92 are communicated with each other at least while the engine 1 is operating.

In this way, according to the modification of the first embodiment, vaporized ammonia out of the fuel drain supplied to the tank body 71 of the drain tank 70 can be supplied to the compressor 92. Thereby, ammonia can be supplied to the cylinder 16 via the supercharger 91 and reused for combustion within the cylinder 16.

In addition, by removing gas from the drain tank 70, the pressure inside the tank body 71 can be kept low. This is effective in smoothly guiding the fuel drain to the drain tank 70.

In addition, since fuel drain is basically discharged from the fuel injection valve 30 while the engine 1 is operating, the fuel drain is discharged from the fuel injection valve 30 to the cylinder 16 via the supercharger 91. By supplying ammonia, the ammonia can be reused in a timely manner.

<Second embodiment>
FIG. 4 is a schematic diagram illustrating a drain system 100 according to the second embodiment.

As illustrated in FIG. 4, the fuel injection valve 30 according to the second embodiment pumps the above-described first fuel using the fuel pump 41, and also provides the above-described injection into the path for pumping the first fuel. The pump 51 injects a second fuel made of volatile fuel (in this embodiment, "ammonia") and water. By doing so, the fuel injection valve 30 can inject the second fuel and water in a layered manner in addition to the first fuel.

Here, as the first fuel, for example, a fuel consisting of diesel fuel, distillate oil, residual oil, etc. can be used. The fuel injection valve 30 according to the second embodiment injects diesel fuel as the first fuel. Therefore, in FIG. 4, the diesel fuel indicated by the symbol F2 is injected into the combustion chamber 17 in a form in which ammonia indicated by the symbol F1 and water indicated by the symbol W3 are sandwiched.

With this configuration, the fuel injection valve 30 injects diesel fuel, ammonia, diesel fuel, water, and diesel fuel in a layered manner in order from the leading side (so-called " "Layered injection") is possible. Generally, ammonia has inferior ignitability compared to diesel fuel. Therefore, by injecting diesel fuel together with ammonia, the ignitability of ammonia can be supplemented. Furthermore, by injecting water together with diesel fuel, it is possible to suppress the generation of NOx associated with combustion.

Here, the merging section 62 according to the second embodiment is composed of a hopper as in the first embodiment, and is configured in an airtight manner using a biting joint 66. This merging portion 62 is provided in the middle of the fuel drain pipe 60 so that the fuel drain discharged from each fuel injection valve 30 merges.

In this case, the fuel drain discharged through the fuel drain pipe 60 is a mixture of ammonia as the second fuel, diesel fuel as the first fuel, and water used for stratified injection. Here, the inventors of the present application focused on the fact that ammonia as the second fuel has water solubility, and created a new method of dissolving the fuel drain containing ammonia in water.

That is, water (hereinafter referred to as "reserved water" and given the symbol "W") is stored in advance in the drain tank 70 according to the present embodiment. Specifically, a predetermined amount of stored water W is accommodated in the tank body 71 of the drain tank 70, and the tank-side relay pipe 65 of the fuel drain pipe 60 extends so as to be immersed in this stored water W. By doing so, ammonia contained in the fuel drain will dissolve into the stored water W.

Here, depending on the capacity of the stored water W, ammonia may not be sufficiently dissolved.

Therefore, the drain tank 70 according to the second embodiment includes a water supply path 72 that is connected to a tank body 71 and supplies stored water W to the tank body 71, and a third opening/closing valve 73 that opens and closes this water supply path 72. , and a level sensor 77 that detects the level of the stored water W in the tank body 71.

Among these, the water supply path 72 is connected to a water tank (not shown) and opens near the bottom of the tank body 71. Further, the third on-off valve 73 is opened and closed according to the detection result of the level sensor 77. Specifically, when the water level of the stored water W becomes less than "Low", the third on-off valve 73 is opened, and when the water level of the stored water W becomes "Middle" or higher, the third on-off valve 73 is opened. Closed state. By doing so, the water level of the stored water W can be maintained at a predetermined level or higher.

In addition, the drain tank 70 in 2nd Embodiment is connected to the incineration system 80 similarly to the said 1st Embodiment. By doing so, ammonia evaporated from the stored water W can be appropriately discharged.

Furthermore, since the fuel drain contains diesel fuel and water in addition to ammonia, there is a possibility that the capacity of the stored water W mixed with such fuel drain becomes excessive compared to the volume of the tank body 71. be.

Therefore, the drain tank 70 according to the second embodiment includes a drainage path 74 that is connected to the tank body 71 and discharges the stored water W from the tank body 71, and a fourth opening/closing valve 75 that opens and closes this drainage path 74. , and a drainage tank 76 connected to the tank body 71 via a drainage path 74.

Among these, the drainage path 74 connects the tank body 71 and the drainage tank 76, and opens near the bottom of the tank body 71. Further, the fourth on-off valve 75 is opened and closed according to the detection result of the level sensor 77. Specifically, when the water level of the stored water W becomes "HIGH" or higher, the fourth on-off valve 75 is opened, and when the water level of the stored water W becomes less than "Middle", the fourth on-off valve 75 is closed. state. By doing so, the water level of the stored water W can be maintained below a predetermined level.

Moreover, the drainage tank 76 according to the second embodiment is configured as an oil-water separation tank. That is, the drain tank 76 separates the stored water W mixed with the fuel drain into an oil component caused by diesel fuel as the first fuel and a water content in which ammonia is dissolved as the second fuel. The oil thus separated can be sent to the incineration system 80 to be incinerated, or can be reused for stratified injection from the fuel injection valve 30. The separated water can also be reused for stratified injection from the fuel injection valve 30.

As described above, according to the second embodiment, the fuel drain (particularly the fuel drain containing ammonia) supplied to the drain tank 70 via the fuel drain pipe 60 is drained from the water stored in the tank body 71. It will blend into W. Thereby, diffusion of ammonia into the air can be suppressed.

Further, as shown in FIG. 4, by providing a drainage tank 76 configured as an oil-water separation tank, the mixture of fuel drain and stored water W is divided into water in which ammonia is dissolved and oil made of diesel fuel. Can be separated. This allows ammonia and diesel fuel to be reused separately, or at least one of them can be incinerated.

-Modification of the second embodiment-
FIG. 5 is a schematic diagram showing a modification of the drain system 100 according to the second embodiment.

Although the second embodiment described the configuration in which the incineration system 80 was connected to the drain tank 70, the present disclosure is not limited to this configuration. Similar to the modification of the first embodiment, a supercharging system 90 may be connected to the drain tank 70 (see FIG. 5).

<Other embodiments>
In the first and second embodiments, the merging section 62 includes a hopper for fuel drain, but the present disclosure is not limited to such a configuration. The merging portion 62 according to the present disclosure also includes a member that is not formed in a funnel shape and a member that does not have a predetermined volume.

Further, in the first and second embodiments, the configuration using the biting joint 66 to configure the merging portion 62 in an airtight manner is exemplified, but the present disclosure is not limited to this configuration. For example, the merging portion 62 may be sealed using a resin seal member, a metal seal, or the like.

Further, in the first and second embodiments, a configuration in which the incineration system 80 and the supercharging system 90 are alternatively provided is illustrated, but the present disclosure is not limited to this configuration. For example, the drain system 100 may include both the incineration system 80 and the supercharging system 90.

1 Engine (marine internal combustion engine)
16 Cylinder 30 Fuel injection valve 30a First injection valve 30b Second injection valve 60 Fuel drain pipe 62 Merging section 66 Biting joint 70 Drain tank 71 Tank body 76 Drainage tank (oil/water separation tank)
80 Incineration system 81 Boiler 82 First vaporized fuel supply pipe 90 Supercharging system 91 Supercharger 92 Compressor 93 Turbine 94 Second vaporized fuel supply pipe W Reserved water (water)

Claims (5)

a plurality of fuel injection valves provided in the cylinder and injecting volatile fuel;
a drain tank that stores fuel drain discharged from the plurality of fuel injection valves;
a fuel drain pipe connecting the plurality of fuel injection valves and the drain tank;
a merging section provided at a midway point in the fuel drain pipe, where fuel drain discharged from each of the plurality of fuel injection valves joins;
The marine internal combustion engine is characterized in that the merging section includes a hopper for draining fuel and is configured in an airtight manner. a plurality of fuel injection valves provided in the cylinder and injecting volatile fuel;
a drain tank that stores fuel drain discharged from the plurality of fuel injection valves;
a fuel drain pipe connecting the plurality of fuel injection valves and the drain tank;
a merging section provided at a midway point in the fuel drain pipe, where fuel drain discharged from each of the plurality of fuel injection valves joins;
The merging portion is configured in an airtight manner,
The volatile fuel has water solubility,
A marine internal combustion engine, wherein water is stored in the drain tank in advance. In the marine internal combustion engine according to claim 2 ,
The plurality of fuel injection valves inject at least a first fuel made of diesel fuel and a second fuel made of the volatile fuel in a layered manner,
A marine internal combustion engine, wherein an oil-water separation tank is connected to the drain tank. a plurality of fuel injection valves provided in the cylinder and injecting volatile fuel;
a drain tank that stores fuel drain discharged from the plurality of fuel injection valves;
a fuel drain pipe connecting the plurality of fuel injection valves and the drain tank;
a merging section provided at a midway point in the fuel drain pipe, where fuel drain discharged from each of the plurality of fuel injection valves joins;
The merging portion is configured in an airtight manner,
a boiler that incinerates the volatile fuel;
A marine internal combustion engine comprising: a first vaporized fuel supply pipe connecting the boiler and the drain tank. The marine internal combustion engine according to any one of claims 1 to 4 ,
A supercharger comprising a compressor that compresses air and a turbine that drives the compressor, and supplies the air compressed by the compressor to the cylinder;
A marine internal combustion engine comprising: a second vaporized fuel supply pipe connecting the compressor and the drain tank.

Images