JP6979335B2 - Marine diesel engine - Google Patents

Description

The present invention relates to a marine diesel engine mounted on a ship.

Conventionally, in the field of ships, a marine diesel engine to which a plurality of turbochargers such as a two-stage turbocharger is applied is known as a means for improving the output of the engine body and the fuel efficiency. For example, in Patent Documents 1 and 2, by rotating a compressor together with a turbine using the exhaust gas discharged from the engine body as a power source, combustion gas such as air is compressed in two stages and supplied to the engine body. A two-stage supercharged diesel engine equipped with a high-pressure stage supercharger and a low-pressure stage supercharger is disclosed.

The diesel engine described in Patent Document 1 has a structure in which a high-pressure turbocharger and a low-pressure turbocharger are integrated and arranged on one side of an engine body. In this diesel engine
The low-pressure turbocharger is arranged in a state of being close to one side of the engine body in consideration of being larger and heavier than the high-pressure turbocharger. The high-pressure turbocharger is arranged so as to be aligned with the side of the low-pressure turbocharger (that is, in the direction perpendicular to the rotation axis of the turbine and the compressor) while being separated from one side surface of the engine body to the outside. Has been done.

The diesel engine described in Patent Document 2 has a structure in which a high-pressure turbocharger and a low-pressure turbocharger are distributed and arranged on both end faces in the width direction of the engine body. In this diesel engine, the high-pressure turbocharger and the low-pressure turbocharger are arranged side by side in a state of being separated from each other by the width dimension of the engine body.

Japanese Patent No. 6109040 Japanese Patent No. 6109041

By the way, the exhaust gas generated in the engine body is sequentially discharged to each turbine of the high-pressure stage supercharger and the low-pressure stage supercharger through piping in order to drive the high-pressure stage supercharger and the low-pressure stage supercharger. In this process, the heat dissipation and pressure loss of the exhaust gas tend to increase with the distribution of the exhaust gas through the piping. Therefore, from the viewpoint of reducing heat dissipation and pressure loss (hereinafter collectively referred to as “energy loss”) of the exhaust gas that is the power source of the turbine, it is preferable to shorten the exhaust gas piping.

However, in the prior art described in Patent Documents 1 and 2, shortening of the exhaust gas pipe is restricted due to the arrangement relationship between the high-pressure stage turbocharger and the low-pressure stage turbocharger described above. For example, in the prior art described in Patent Document 1, since the high-pressure stage turbocharger and the low-pressure stage turbocharger are arranged so as to be laterally separated from each other, a pipe for connecting these turbines is provided. It is difficult to shorten. In particular, in the prior art described in Patent Document 2, since the high-pressure stage turbocharger and the low-pressure stage turbocharger are arranged apart from each other by the width dimension of the engine body, a pipe for connecting these turbines is provided. It is extremely difficult to shorten it. Therefore, with the prior art described in Patent Documents 1 and 2, it is difficult to reduce the energy loss of the exhaust gas that is the power source of the turbine of each supercharger exemplified by the high-pressure stage supercharger and the low-pressure stage supercharger. Is.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a marine diesel engine capable of reducing the energy loss of exhaust gas which is a power source of a turbine of each turbocharger.

In order to solve the above-mentioned problems and achieve the object, the marine diesel engine according to the present invention has an engine body that burns fuel and outputs the propulsive force of a ship from an output shaft, and an exhaust gas discharged from the engine body. A first turbocharger with a radial turbine that receives and rotates,
A second supercharger having an axial flow turbine which is arranged so as to face the radial turbine in the rotation axis direction of the radial turbine and rotates by receiving the exhaust gas sent from the radial turbine, and the radial turbine. It is characterized by comprising a distribution pipe which is arranged between the axial flow turbine and circulates the exhaust gas from the radial turbine to the axial flow turbine.

Further, the marine diesel engine according to the present invention is characterized in that, in the above invention, the marine diesel engine includes an exhaust pipe that discharges the exhaust gas from the engine body toward the radial turbine in the radial direction of the radial turbine.

Further, the marine diesel engine according to the present invention is characterized in that, in the above invention, the rotating shaft of the radial turbine and the rotating shaft of the axial flow turbine are located on the same axis.

Further, the marine diesel engine according to the present invention is characterized in that, in the above invention, the rotation shaft of the radial turbine and the rotation shaft of the axial flow turbine are parallel to the output shaft of the engine body. do.

Further, in the above-mentioned invention, the marine diesel engine according to the present invention includes a first cooler for cooling the combustion gas compressed by the compressor of the second supercharger and the first supercharger. A second cooler, which cools the combustion gas further compressed by the compressor of the above, is provided.
The second supercharger is arranged above the first cooler, and the first supercharger is arranged above the second cooler.

Further, in the marine diesel engine according to the present invention, in the above invention, the engine body includes an exhaust manifold, and the first supercharger and the second supercharger have an exhaust manifold as compared with the exhaust manifold. It is characterized in that it is arranged on the lower side in the height direction of the engine body.

Further, in the marine diesel engine according to the present invention, in the above invention, the distribution pipe is
It is characterized by including an expansion / contraction tube that can be expanded / contracted in the direction of the rotation axis.

Further, the marine diesel engine according to the present invention is characterized in that, in the above invention, the second turbocharger is a larger turbocharger than the first turbocharger.

According to the present invention, it is possible to reduce the energy loss of the exhaust gas that is the power source of the turbine of each turbocharger.

FIG. 1 is a schematic diagram showing a configuration example of a marine diesel engine according to an embodiment of the present invention. FIG. 2 is a schematic view showing an example of the arrangement configuration of the high-pressure stage turbine and the low-pressure stage turbine according to the embodiment of the present invention.

Hereinafter, preferred embodiments of the marine diesel engine according to the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the present embodiment.
In addition, it should be noted that the drawings are schematic, and the relationship between the dimensions of each element, the ratio of each element, etc. may differ from the actual ones. Even between the drawings, there may be parts where the relationship and ratio of the dimensions are different from each other. Further, in each drawing, the same components are designated by the same reference numerals.

(Composition of marine diesel engine)
First, the configuration of the marine diesel engine according to the embodiment of the present invention will be described. Figure 1
Is a schematic diagram showing a configuration example of a marine diesel engine according to an embodiment of the present invention. As shown in FIG. 1, the marine diesel engine 10 according to the present embodiment includes an engine body 1 and an engine body 1.
A two-stage turbocharger 11 that supercharges the combustion gas to the engine body 1, an intercooler 15 that cools the combustion gas after the first-stage compression by the two-stage turbocharger 11, and a two-stage system. A cooler 16 for cooling the combustion gas after the second stage compression by the supercharger 11 is provided. Further, the marine diesel engine 10 includes air supply pipes 101, 102, 103 as air supply pipes and exhaust pipes 111, 112, 113, 114 as exhaust pipes. Of these pipes, the exhaust pipe 1
Reference numerals 12 and 113 are pipes for the two-stage turbocharger 11. In FIG. 1, the solid line arrow indicates the flow of the exhaust gas from the engine body 1, and the broken line arrow indicates the flow of the combustion gas.

Although not shown, the engine body 1 is a propulsion engine (main engine) that drives and rotates a propulsion propeller of a ship via a propeller shaft. The engine body 1 is a two-stroke diesel engine such as a uniflow sweep-exhaust type crosshead diesel engine. Specifically, as shown in FIG. 1, the engine body 1 is located below the D11 in the height direction of the engine body 1 (
It includes a base plate 2 located on the lower side), a frame 3 provided on the base plate 2, and a cylinder jacket 4 provided on the frame 3. The base plate 2, the frame 3, and the cylinder jacket 4 are integrally fastened and fixed by connecting members such as a plurality of tie bolts (not shown) and nuts (not shown) extending in the height direction D11. Has been done.

The base plate 2 constitutes a crankcase. Although not shown, the base plate 2 is provided with a propeller shaft, a crankshaft, and the like for driving and rotating the propulsion propeller. The crankshaft is rotatably supported by bearings. A lower end of a connecting rod (not shown) is rotatably connected to the crankshaft via a crank.

The frame 3 is provided with the above-mentioned connecting rod, a piston rod (not shown), and a crosshead (not shown) that rotatably connects the piston rod and the connecting rod. Specifically, the lower end of the piston rod and the upper end of the connecting rod are connected to the crosshead. The crosshead is arranged between a pair of guide plates (not shown) fixed to the frame 3, and is slidably supported along the pair of guide plates.

As shown in FIG. 1, the cylinder jacket 4 is provided with a cylinder liner 5 extending from the inside to the upper part of the cylinder jacket 4, and a cylinder cover 6 is provided at the upper end portion of the cylinder liner 5. There is. These cylinder liner 5 and cylinder cover 6
And so on, the cylinder of the engine body 1 is formed. In the present embodiment, a plurality of cylinders (six in FIG. 1) are formed in the engine main body 1. Fuel is supplied to each of these plurality of cylinders from a fuel injection pump (not shown). On the other hand, in the internal space of the cylinder, a piston (not shown) is provided so as to reciprocate along the inner wall of the cylinder. The upper end of the piston rod described above is attached to the lower end of the piston.

Further, the engine body 1 includes a scavenging trunk 7 and an exhaust manifold 8. As shown in FIG. 1, the scavenging trunk 7 is provided in the cylinder jacket 4 and communicates with the combustion chamber in each cylinder via the scavenging port (not shown) of the engine body 1. The scavenging trunk 7 receives combustion gas such as compressed air and sends the received combustion gas to the combustion chamber in each cylinder. As shown in FIG. 1, the exhaust manifold 8 is provided above the cylinder jacket 4 (for example, in the vicinity of the cylinder cover 6), and is provided with a combustion chamber in each cylinder via an exhaust port (not shown) of the engine body 1. Communicating. The exhaust manifold 8 receives the exhaust gas generated by the combustion of the fuel from the combustion chamber in each cylinder and temporarily stores the exhaust gas, whereby the dynamic pressure of the exhaust gas is changed to the static pressure.

The engine body 1 having the above-described configuration reciprocates the piston by burning fuel together with the combustion gas sent from the scavenging trunk 7 in the combustion chamber in each cylinder. The engine body 1 outputs the propulsive force of the ship from this output shaft by converting this reciprocating motion into the rotational motion of an output shaft such as a propeller shaft or a crankshaft. At this time, the engine main body 1 makes the flow of intake and exhaust in each cylinder one direction from the lower side to the upper side so as to eliminate the residual exhaust gas. Specifically, combustion gas is supplied from the scavenging trunk 7 to the combustion chambers in each cylinder, and the exhaust gas after combustion is discharged from the combustion chambers in each cylinder to the exhaust manifold 8.

In the present embodiment, the height direction D11 of the engine body 1 is the vertical direction, and is parallel to, for example, the direction of the reciprocating movement of the piston. The width direction D12 of the engine body 1 is
It is parallel to the output axial direction D2 shown in FIG. The output shaft direction D2 is the longitudinal direction of the output shaft of the engine body 1. These height direction D11 and width direction D12 are perpendicular to each other. Further, in the present embodiment, the exhaust gas is a gas discharged from the engine body 1 to the outside through piping or the like.

The two-stage turbocharger 11 is an example of a multi-stage turbocharger that can use exhaust gas from the engine body 1 to gradually compress combustion gas such as air and supply it to the engine body 1. .. In the present embodiment, as shown in FIG. 1, the two-stage turbocharger 11 includes a high-pressure stage turbocharger 12 and a low-pressure stage turbocharger 1.
3, the silencer 14, and the exhaust pipes 112 and 113 are provided.

The high-pressure turbocharger 12 is a first turbocharger that supercharges combustion gas using exhaust gas discharged from the engine body 1. Specifically, as shown in FIG. 1, the high-pressure stage turbocharger 12 includes a high-pressure stage turbine 12a and a high-pressure stage compressor 12b. Further, although not shown in FIG. 1, the high-pressure turbocharger 12 includes a high-pressure turbine 12a and a high-pressure compressor 12b.
A rotating shaft (rotating shaft 12c shown in FIG. 2 to be described later) is provided. High pressure stage turbine 12a
And the high-pressure stage compressor 12b is configured so that it can rotate integrally with this rotation axis as a central axis.

The high-pressure stage turbine 12a is a radial turbine that rotates by receiving the exhaust gas discharged from the engine main body 1, and is provided in the engine main body 1 in a state of being housed in the casing. In the present embodiment, as shown in FIG. 1, an exhaust pipe 111 is connected to the gas inlet side of the casing of the high-pressure stage turbine 12a. The high-pressure stage turbine 12a receives the exhaust gas from the engine body 1 in the radial direction of the high-pressure stage turbine 12a (hereinafter, abbreviated as the turbine radial direction) through the exhaust pipe 111, and can rotate using the energy of the exhaust gas as a power source. It is configured as follows. Further, as shown in FIG. 1, on the gas outlet side of the casing of the high-pressure stage turbine 12a,
The exhaust pipes 112 and 113 are connected in series with the rotation axis direction D1 of the high pressure stage turbine 12a. As described above, the high-pressure stage turbine 12a is configured to send the exhaust gas received in the radial direction of the turbine to the rotation axis direction D1 and distribute it in the exhaust pipes 112 and 113.

The rotation axis direction D1 is the longitudinal direction of the rotation axis of the high-pressure stage turbine 12a. The turbine radial direction is the radial direction of the radial turbine constituting the high-pressure stage turbine 12a (specifically, the radial direction of the turbine disk). The rotational axis direction D1 and the turbine radial direction are perpendicular to each other.

The high-pressure stage compressor 12b is a compressor that performs a second-stage compression of the combustion gas in the two-stage turbocharger 11. The high-pressure stage compressor 12b is composed of an impeller or the like integrally connected to the high-pressure stage turbine 12a via a rotating shaft, and is housed in a casing so as to be able to rotate integrally with the high-pressure stage turbine 12a. It is provided in 1. Specifically, as shown in FIG. 1, the high-pressure stage compressor 12b is arranged on the opposite side of the high-pressure stage turbine 12a described above from the low-pressure stage supercharger 13. An intercooler 1 is located on the gas inlet side of the casing of the high-pressure compressor 12b.
The air supply pipe 102 leading to 5 is connected. Further, an air supply pipe 103 leading to the cooler 16 is connected to the gas outlet side of the casing of the high-pressure stage compressor 12b.

The low-pressure turbocharger 13 is a second turbocharger that supercharges the combustion gas using the exhaust gas sent from the high-pressure turbocharger 12. Specifically, as shown in FIG.
The low-pressure stage turbocharger 13 includes a low-pressure stage turbine 13a and a low-pressure stage compressor 13b. also,
Although not shown in FIG. 1, the low-pressure stage turbocharger 13 includes a low-pressure stage turbine 13a and a low-pressure stage compressor 13.
A rotating shaft (rotating shaft 13c shown in FIG. 2 to be described later) for connecting to b is provided. Low pressure stage turbine 13
The low-pressure stage compressor 13b and a and the low-pressure stage compressor 13b are configured to be able to rotate integrally with this rotation axis as a central axis.

The low-pressure stage turbine 13a is an axial flow turbine that rotates by receiving exhaust gas sent from the high-pressure stage turbine 12a (radial turbine), and is provided in the engine main body 1 in a state of being housed in a casing. Specifically, as shown in FIG. 1, the low-pressure stage turbine 13a is arranged so as to face the high-pressure stage turbine 12a in the rotation axis direction D1 of the high-pressure stage turbine 12a. That is, the rotation axis direction (longitudinal direction of the rotation axis) of the low-pressure stage turbine 13a is the same as the rotation axis direction D1 of the high-pressure stage turbine 12a. Exhaust pipes 112 and 113 leading to the high-pressure stage turbine 12a are connected to the gas inlet side of the casing of the low-pressure stage turbine 13a. The low-pressure stage turbine 13a uses the exhaust gas sent from the high-pressure stage turbine 12a as exhaust pipes 112 and 11.
It is configured to be received in the rotation axis direction D1 through 3 and to be able to rotate using the energy of this exhaust gas as a power source. Further, as shown in FIG. 1, an exhaust pipe 114 leading to a chimney or the like (not shown) for discharging exhaust gas to the outside is connected to the gas outlet side of the casing of the low-pressure stage turbine 13a. As described above, the low-pressure stage turbine 13a is configured to circulate the exhaust gas received in the rotation axis direction D1 into the exhaust pipe 114.

The low-pressure stage compressor 13b is a compressor that performs the first stage compression of the combustion gas in the two-stage turbocharger 11. The low-pressure stage compressor 13b is composed of an impeller or the like integrally connected to the low-pressure stage turbine 13a via a rotating shaft, and is housed in a casing so as to be able to rotate integrally with the low-pressure stage turbine 13a. It is provided in 1. Specifically, as shown in FIG. 1, the low-pressure stage compressor 13b is arranged on the opposite side of the high-pressure stage turbocharger 12 with respect to the above-mentioned low-pressure stage turbine 13a. The silencer 1 is located on the gas inlet side of the casing of the low-pressure compressor 13b.
4 is provided. The silencer 14 reduces noise when inhaling air (fresh air) from the outside. The suction port of the silencer 14 is provided with a filter (not shown) for preventing the suction of foreign matter. On the other hand, an air supply pipe 101 leading to the intercooler 15 is connected to the gas outlet side of the casing of the low pressure stage compressor 13b.

The exhaust pipe 111 is a pipe that discharges exhaust gas in the radial direction of the turbine from the engine main body 1 toward the high-pressure stage turbine 12a. In this embodiment, as shown in FIG. 1, the exhaust pipe 111
One end is connected to the exhaust manifold 8 and the other end is connected to the gas inlet portion of the casing of the high-pressure stage turbine 12a, and the exhaust manifold 8 and the inside of the casing of the high-pressure stage turbine 12a are communicated with each other in the turbine radial direction. Such an exhaust pipe 111 discharges the exhaust gas generated in the engine body 1 from the exhaust manifold 8 toward the high-pressure stage turbine 12a in the turbine radial direction.

The exhaust pipes 112 and 113 are pipes arranged between the high-pressure stage turbine 12a and the low-pressure stage turbine 13a to form a distribution pipe for flowing exhaust gas from the high-pressure stage turbine 12a to the low-pressure stage turbine 13a. Specifically, as shown in FIG. 1, the exhaust pipes 112 and 113 are connected in series in the rotation axis direction D1 over a region from the gas outlet side of the high-pressure stage turbine 12a to the gas inlet side of the low-pressure stage turbine 13a. Has been done. Such exhaust pipes 112 and 113 communicate the internal spaces of the casings of the high-pressure stage turbine 12a and the low-pressure stage turbine 13a facing each other in the rotation axis direction D1 in the rotation axis direction D1 and deliver the exhaust pipes 112 and 113 from the high-pressure stage turbine 12a. It is possible to circulate the exhaust gas to the low pressure stage turbine 13a in the rotation axis direction D1.

The intercooler 15 is a cooler for cooling the combustion gas after the first stage compression by the two-stage turbocharger 11. Specifically, as shown in FIG. 1, the intercooler 15 is the air supply pipe 101.
It is configured to communicate with the inside of the casing of the low-pressure stage compressor 13b and to the inside of the casing of the high-pressure stage compressor 12b via an air supply pipe 102 or the like, and is provided in the engine main body 1. The intercooler 15 is a combustion gas that flows from the low-pressure stage compressor 13b through the air supply pipe 101 and flows from the air supply pipe 102 to the high-pressure stage compressor 12b side, that is, the low-pressure stage compressor 13b.
The high-temperature combustion gas compressed by the above is cooled by, for example, heat exchange with cooling water.

The cooler 16 is for cooling the combustion gas after the second stage compression by the two-stage turbocharger 11. Specifically, as shown in FIG. 1, the cooler 16 communicates with the inside of the casing of the high-pressure stage compressor 12b through the air supply pipe 103 and passes through an internal space or the like (not shown) to the scavenging trunk of the engine body 1. It is configured to communicate with 7 and is provided in the engine body 1. The cooler 16 flows from the high-pressure stage compressor 12b through the air supply pipe 103 and flows into the scavenging trunk 7.
The combustion gas flowing to the side, that is, the high-temperature combustion gas further compressed by the high-pressure stage compressor 12b is cooled by, for example, heat exchange with cooling water.

Here, in the marine diesel engine 10 according to the present embodiment, the rotation axes of the high-pressure turbocharger 12 and the low-pressure turbocharger 13 constituting the two-stage turbocharger 11 may be parallel to each other. However, it is preferable that they are located on the same axis. Further, with respect to the rotation axis direction D1 shown in FIG. 1, the high-pressure stage turbocharger 12, the low-pressure stage turbocharger 13, the silencer 14, and the exhaust pipes 112, 11
It is preferable that each central axis of 3 is located on the same axis. Further, in the present embodiment, the rotation axis direction D1 of the high-pressure stage turbocharger 12 and the low-pressure stage turbocharger 13 is the output shaft direction D of the engine body 1.
It is parallel to 2 (width direction D12). That is, the rotation shaft of the high-pressure stage turbine 12a and the rotation shaft of the low-pressure stage turbine 13a are parallel to the output shaft of the engine body 1. Further, the two-stage turbocharger 11 is arranged between the exhaust manifold 8 and the intercooler 15 and the cooler 16 in the height direction D11 of the engine body 1. Specifically, as shown in FIG. 1, the high-pressure turbocharger 12 and the low-pressure turbocharger 13 are arranged below the exhaust manifold 8 in the height direction D11. Moreover, the high-pressure stage compressor 12b is arranged above the cooler 16, and the low-pressure stage compressor 13b is arranged above the intercooler 15.

The arrangement configuration of the two-stage turbocharger 11 in the marine diesel engine 10 is as described above (
Although not limited to FIG. 1), it is said that the length of the exhaust gas pipe, which is the power source of the two-stage turbocharger 11, is shortened to reduce the energy loss of the exhaust gas, and the marine diesel engine 10 is downsized. From the viewpoint, the above-mentioned one is preferable.

Further, from the viewpoint of improving the supercharging efficiency of the combustion gas by the two-stage turbocharger 11, the low-pressure turbocharger 13 may be a larger turbocharger than the high-pressure turbocharger 12. preferable. That is, it is preferable that the low-pressure stage turbine 13a is a larger turbine than the high-pressure stage turbine 12a, and the low-pressure stage compressor 13b is a larger-sized compressor than the high-pressure stage compressor 12b.

(Supercharging operation of combustion gas)
Next, the supercharging operation of the combustion gas to the engine main body 1 in the marine diesel engine 10 according to the present embodiment will be described with reference to FIG. 1. Marine diesel engine 10
The two-stage turbocharger 11 supercharges combustion gas such as air to the engine body 1 by operating the exhaust gas discharged from the engine body 1 as a power source.

Specifically, as shown in FIG. 1, the exhaust gas generated in the combustion chamber in each cylinder of the engine body 1 is temporarily stored in the exhaust manifold 8 and then from the exhaust manifold 8 to the exhaust pipe 111.
It is supplied to the high-pressure stage turbine 12a through. The high-pressure stage turbine 12a receives the exhaust gas from the exhaust pipe 111 in the radial direction of the turbine and rotates, while delivering the exhaust gas used for this rotation in the rotation axis direction D1. The exhaust gas sent from the high-pressure stage turbine 12a is the exhaust pipe 112, 1
It is supplied to the low pressure stage turbine 13a through 13. The low-pressure stage turbine 13a has an exhaust pipe 11
The exhaust gas from 2, 113 is received in the rotation axis direction D1 and rotates. The exhaust gas used for this rotation is sent from the low-pressure stage turbine 13a to the exhaust pipe 114, and then discharged to the outside from the chimney (not shown) through the exhaust pipe 114 or the like.

The rotation of the low-pressure stage turbine 13a powered by the exhaust gas from the high-pressure stage turbine 12a is transmitted to the low-pressure stage compressor 13b via the rotation shaft. As a result, the low-pressure stage compressor 13b rotates with the rotation of the low-pressure stage turbine 13a. The low-pressure stage compressor 13b in the rotated state sucks air (fresh air) from the outside as a combustion gas through the suction port (suction port provided with a filter) of the silencer 14, and the sucked combustion gas. Compress the gas (first stage compression). The low-pressure stage compressor 13b pumps the combustion gas boosted by this compression action to the intercooler 15 through the air supply pipe 101. The combustion gas after compression by the low-pressure stage compressor 13b flows into the intercooler 15 through the air supply pipe 101, is cooled by the intercooler 15, and then is compressed by the high-pressure stage from the intermediate cooler 15 through the air supply pipe 102 and the like. It is supplied to the machine 12b.

On the other hand, the rotation of the high-pressure stage turbine 12a powered by the exhaust gas from the engine body 1 is transmitted to the high-pressure stage compressor 12b via the rotation shaft. As a result, the high-pressure stage compressor 12b rotates with the rotation of the high-pressure stage turbine 12a. The high-pressure stage compressor 12b in the rotated state further compresses the combustion gas supplied through the air supply pipe 102, that is, the combustion gas after compression by the low-pressure stage compressor 13b described above (second stage). compression). The high-pressure stage compressor 12b pumps the combustion gas further boosted by this compression action to the cooler 16 through the air supply pipe 103. The combustion gas after compression by the high-pressure stage compressor 12b is the air supply pipe 103.
After flowing into the cooler 16 through the cooler 16 and being cooled by the cooler 16, the air is supplied from the cooler 16 to the scavenging trunk 7 of the engine body 1 through an internal space or the like.

In this way, the engine body 1 is supercharged with a required amount of combustion gas. The supercharged combustion gas is supplied (scavenged) from the scavenging trunk 7 to the combustion chamber in each cylinder of the engine body 1 and burned together with the fuel.

(Turbine layout)
Next, the arrangement configuration of the high-pressure stage turbine 12a and the low-pressure stage turbine 13a in the present embodiment will be described in detail. FIG. 2 is a schematic view showing an example of the arrangement configuration of the high-pressure stage turbine and the low-pressure stage turbine according to the embodiment of the present invention. In FIG. 2, the solid arrow indicates the distribution of exhaust gas, which is the power source for turbine rotation.

As shown in FIG. 2, the high-pressure stage turbine 12a is a radial turbine that receives exhaust gas in the radial direction of the turbine and rotates, and is housed in a casing 12d. An exhaust pipe 111 is connected to the gas inlet portion of the casing 12d. Inside the casing 12d, a flow passage leading from the gas inlet side to the gas outlet side via the high-pressure stage turbine 12a is formed. The high-pressure stage turbine 12a receives exhaust gas from both sides in the turbine radial direction through the flow passages in the exhaust pipe 111 and the casing 12d. The high-pressure stage turbine 12a rotates around the rotation shaft 12c due to the pressure of the exhaust gas from the turbine radial direction, and sequentially sends out the exhaust gas used for this rotation in the rotation axis direction D1. Although not particularly shown in FIG. 2, the high-pressure stage turbine 12a is integrally connected to the high-pressure stage compressor 12b (see FIG. 1) via a rotary shaft 12c.

Further, as shown in FIG. 2, the low-pressure stage turbine 13a is an axial-flow turbine that receives exhaust gas in the rotation axis direction D1 and rotates, and is housed in a casing (not shown). The low-pressure stage turbine 13a receives the exhaust gas sent from the high-pressure stage turbine 12a in the rotation axis direction D1, and is rotated around the rotation shaft 13c by the pressure of the exhaust gas. Although not particularly shown in FIG. 2, the low-pressure stage turbine 13a is integrally connected to the low-pressure stage compressor 13b (see FIG. 1) via a rotary shaft 13c.

As shown in FIG. 2, the high-pressure stage turbine 12a and the low-pressure stage turbine 13a are arranged so as to face each other in the rotation axis direction D1. At this time, the high-pressure stage turbine 12a and the low-pressure stage turbine 13a face each other on the turbine blade side in the rotation axis direction D1. With such a facing arrangement, the distribution path from the exhaust gas sent from the high-pressure stage turbine 12a in the rotation axis direction D1 to being supplied to the axial flow turbine blade of the low-pressure stage turbine 13a can be shortened as much as possible. Further, from the viewpoint of simply shortening the flow pipe forming the flow path, it is preferable that the rotary shaft 12c of the high-pressure stage turbine 12a and the rotary shaft 13c of the low-pressure stage turbine 13a are located on the same shaft. Further, the rotary shaft 12 of the high-pressure stage turbine 12a
It is preferable that the central axis C1 of c and the central axis C2 of the rotating shaft 13c of the low pressure stage turbine 13a coincide with each other on the same axis.

In the present embodiment, the distribution pipe forming the exhaust gas flow path from the high-pressure stage turbine 12a to the low-pressure stage turbine 13a described above is composed of the exhaust pipes 112 and 113 as shown in FIG. One exhaust pipe 112 is a telescopic pipe that can be expanded and contracted in the rotation axis direction D1. One end of the exhaust pipe 112 is connected to the gas outlet portion of the casing 12d of the high-pressure stage turbine 12a, and the other end is connected to the other exhaust pipe 113, so that the casing 12d and the exhaust pipe 113 communicate with each other in the rotation axis direction D1. .. The other exhaust pipe 113 is a pipe that is a part of the gas inlet side in the casing of the low pressure stage turbine 13a. The exhaust pipe 113 has one end of the exhaust pipe 112 described above.
And the other end is connected to the turbine nozzle 13d of the casing of the low pressure stage turbine 13a, and the exhaust pipe 112 and the turbine nozzle 13d are communicated with each other in the rotation axis direction D1. Further, as shown in FIG. 2, a distribution path is formed inside the exhaust pipe 113 so as to branch from the high-pressure stage turbine 12a side to the low-pressure stage turbine 13a side on both sides of the low-pressure stage turbine 13a in the turbine radial direction. There is.

These exhaust pipes 112 and 113 are arranged between the high-pressure stage turbine 12a and the low-pressure stage turbine 13a so as to extend in the rotation axis direction D1, for example, and allow exhaust gas to flow from the high-pressure stage turbine 12a to the low-pressure stage turbine 13a. .. Specifically, as shown in FIG. 2, one exhaust pipe 1
12 distributes the exhaust gas sent from the high-pressure stage turbine 12a in the rotation axis direction D1 from the gas outlet portion of the casing 12d of the high-pressure stage turbine 12a toward the other exhaust pipe 113 in the rotation axis direction D1. The other exhaust pipe 113 distributes the exhaust gas sent from the exhaust pipe 112 in the rotation axis direction D1 in the rotation axis direction D1 while diversion toward the turbine nozzle 13d of the casing of the low-pressure stage turbine 13a. Further, the exhaust pipe 112, which is a telescopic pipe, absorbs the thermal stress received by the exhaust pipes 112 and 113 due to the flow of high-temperature exhaust gas by the expansion and contraction in the rotation axis direction D1. As a result, the exhaust pipe 112 prevents deformation and breakage of the exhaust pipes 112 and 113 due to thermal stress.

The exhaust gas supplied from the turbine nozzle 13d to the low-pressure stage turbine 13a through the exhaust pipes 112 and 113 flows into the exhaust pipe 114 in the casing of the low-pressure stage turbine 13a after rotating the low-pressure stage turbine 13a. After that, this exhaust gas is discharged to the outside from the chimney through the exhaust pipe 114 and the like.

As described above, in the marine diesel engine 10 according to the embodiment of the present invention, the high-pressure stage turbine 12a included in the high-pressure stage supercharger 12 (first supercharger) is exhausted from the engine body 1. The low-pressure stage turbine 13a of the low-pressure stage supercharger 13 (second supercharger) is used as an axial flow turbine that rotates by receiving the exhaust gas sent from the high-pressure stage turbine 12a. The high-pressure stage supercharger 12 and the low-pressure stage supercharger 13 are arranged so that the high-pressure stage turbine 12a and the low-pressure stage turbine 13a face each other in the rotation axis direction D1, and are between the high-pressure stage turbine 12a and the low-pressure stage turbine 13a. Distribution pipe (for example, exhaust pipe 112) arranged in
, 113), the exhaust gas is circulated from the high-pressure stage turbine 12a to the low-pressure stage turbine 13a.

Therefore, the gas outlet portion of the exhaust gas sent from the high-pressure stage turbine 12a in the rotation axis direction D1 and the gas inlet portion of the low-pressure stage turbine 13a that receives the exhaust gas in the rotation axis direction D1 are separated as much as possible in the rotation axis direction D1. Can be placed in close proximity. As a result, the high-pressure stage turbine 12
The length of the distribution pipe (distribution path length) for flowing the exhaust gas from a to the low-pressure stage turbine 13a can be shortened as much as possible. As a result, heat dissipation and pressure loss due to the flow of exhaust gas through the distribution pipe can be reduced, so that the energy loss of the exhaust gas that is the power source of the turbine of each turbocharger can be reduced.

Further, since the high-pressure turbocharger 12, the low-pressure turbocharger 13, and the above-mentioned distribution pipe can be arranged close to each other in the rotation axis direction D1, the occupied area required for arranging each turbocharger with respect to the engine body 1 can be secured. Can be reduced. As a result, the scale of the marine diesel engine 10 can be reduced, for example.
It can be made smaller than the conventional diesel engine disclosed in Patent Documents 1 and 2 described above.

Further, in the marine diesel engine 10 according to the embodiment of the present invention, an exhaust pipe 111 for discharging exhaust gas in the turbine radial direction from the engine main body 1 toward the high-pressure stage turbine 12a is provided. Therefore, from the engine body 1 (for example, the exhaust manifold 8) to the high pressure stage turbine 1
The distribution route of exhaust gas to 2a can be shortened as much as possible. As a result, shortening of the exhaust pipe 111 forming the distribution path can be promoted, so that the engine body 1 to the exhaust pipe 11 can be shortened.
By reducing the heat dissipation and pressure loss of the exhaust gas discharged to the high-pressure stage turbine 12a through 1,
The energy loss of the exhaust gas, which is the power source of the high-pressure stage turbine 12a, can be reduced as much as possible.

Further, in the marine diesel engine 10 according to the embodiment of the present invention, the high-pressure stage turbine 12
The high-pressure turbocharger 12 and the low-pressure turbocharger 13 are arranged so that the rotary shaft of a and the rotary shaft of the low-pressure stage turbine 13a are located on the same shaft. Therefore, the exhaust gas flow pipe between the high-pressure stage turbine 12a and the low-pressure stage turbine 13a arranged so as to face each other in the rotation axis direction D1 can be easily shortened. As a result, the length of the flow path of the exhaust gas from the high-pressure stage turbine 12a to the low-pressure stage turbine 13a can be easily shortened, so that the energy loss of the exhaust gas can be reduced.

Further, in the marine diesel engine 10 according to the embodiment of the present invention, the high-pressure stage turbine 12
A high-pressure turbocharger 12 and a low-pressure turbocharger 13 are provided in the engine body 1 so that the rotary shaft of a and the rotary shaft of the low-pressure turbine 13a are parallel to the output shaft of the engine body 1. ing. Therefore, it is necessary to arrange each supercharger with respect to the engine body 1 while shortening the flow path length of the exhaust gas that is the power source of the high-pressure stage turbine 12a and the low-pressure stage turbine 13a to reduce the energy loss of the exhaust gas. The occupied area is reduced as much as possible, and the engine body 1
It is possible to suppress the bias of the load applied to the joint portion between the turbocharger and each turbocharger. As a result, compared to the conventional diesel engine disclosed in Patent Documents 1 and 2 described above, the scale of the marine diesel engine 10 can be reduced in size, and the joint portion between the engine body 1 and each supercharger is excessive. Each supercharger can be arranged on the engine body 1 in a well-balanced manner so that an unbalanced load is not applied.

Specifically, in the conventional diesel engine disclosed in Patent Document 1, the high-pressure stage turbocharger and the low-pressure stage turbocharger are perpendicular to each other in the direction of the rotation axis of the turbine (that is, laterally).
It is arranged on one side of the engine body together with related devices such as a cooler in a manner of being arranged apart from each other. In this case, a load excessively biased to one side of the engine body is applied to the joint portion between each of these turbochargers and related devices (hereinafter, abbreviated as "devices such as each supercharger" as appropriate) and the engine body. May be loaded. Therefore, in order to secure the joint between the device such as each turbocharger and the engine main body, it is necessary to firmly reinforce these joint portions. Due to this, there arises a problem that the labor and cost required for arranging the device such as each supercharger with respect to the engine main body increases.

Further, in the conventional diesel engine disclosed in Patent Document 2, a high-pressure stage turbocharger and a low-pressure stage turbocharger are separately arranged on both end faces in the width direction of the engine body together with related devices such as a cooler. There is. In this case, since the device such as each supercharger protrudes from both end faces in the width direction of the engine body, the width dimension of the diesel engine (for example, the length in the output shaft direction of the engine body) increases, and this causes the increase. There is a problem that it becomes difficult to miniaturize the diesel engine. As a result, there is a risk that the space in the engine room where the diesel engine will be installed must be expanded, and as a result, important spaces other than the engine room in the ship, such as cargo and cabin space, must be reduced. ..

In contrast to these conventional diesel engines, the marine diesel engine 10 according to the embodiment of the present invention can promote miniaturization and can arrange each supercharger in the engine body 1 in a well-balanced manner as described above. It can solve all the problems of diesel engine.

Further, in the marine diesel engine 10 according to the embodiment of the present invention, the low-pressure turbocharger 13 is arranged above the intercooler 15, and the high-pressure turbocharger 12 is arranged above the cooler 16.
Therefore, the compressor of the low-pressure turbocharger 13 (low-pressure stage compressor 13b) does not hinder the shortening of the pipe (exhaust pipe 111) that circulates the exhaust gas from the engine body 1 to the high-pressure stage turbine 12a.
Combustion gas after compression from the pipe (air supply pipe 101) that circulates the compressed combustion gas to the intercooler 15 and from the compressor (high pressure stage compressor 12b) of the high-pressure turbocharger 12 to the cooler 16. It is possible to shorten the length of both the pipe (air supply pipe 103) for circulating the gas. As a result, the piping between the high-pressure stage turbocharger 12, the low-pressure stage turbocharger 13, the intercooler 15 and the cooler 16 can be easily configured to be short, and as a result, the scale of the marine diesel engine 10 can be increased. Miniaturization can be easily realized.

Further, in the marine diesel engine 10 according to the embodiment of the present invention, the high-pressure turbocharger 12 and the low-pressure turbocharger 13 are installed in the height direction D11 as compared with the exhaust manifold 8 of the engine body 1.
It is placed on the lower side. Therefore, the exhaust pipe 111 that communicates between the exhaust manifold 8 and the inside of the high-pressure turbine 12a is shortened, and the high-pressure turbocharger 12 and the low-pressure turbocharger 13 are installed from the upper end of the engine body 1. It can be arranged so that it does not protrude. As a result, the height dimension (length in the height direction D11) of the marine diesel engine 10 can be shortened, so that the scale of the marine diesel engine 10 can be further reduced.

Further, in the marine diesel engine 10 according to the embodiment of the present invention, the high-pressure stage turbine 12
The flow pipe that circulates the exhaust gas from a to the low-pressure stage turbine 13a includes a telescopic pipe (exhaust pipe 112) that can be expanded and contracted in the rotation axis direction D1 of these turbines. Therefore, the expansion and contraction due to the heat received by the flow pipe from the high-temperature exhaust gas can be absorbed by the exhaust pipe 112, which is the expansion and contraction pipe. As a result, it is possible to prevent deformation and breakage of the flow pipe due to thermal stress, and as a result, it is possible to extend the life of the flow pipe.

Further, in the marine diesel engine 10 according to the embodiment of the present invention, the low-pressure turbocharger 13 is made larger than the high-pressure turbocharger 12. Therefore, the compression ratio when the combustion gas is compressed stepwise can be easily optimized, and thereby the supercharging efficiency of the combustion gas can be improved.

In the above-described embodiment, two turbochargers (high-pressure turbocharger 12 and low-pressure turbocharger 1) are used.
Although the case where the two-stage turbocharger 11 having 3) is applied to the engine main body 1 is exemplified, the present invention is not limited thereto. For example, a multi-stage turbocharger that gradually compresses the combustion gas by a plurality of (two or more) superchargers may be applied to the engine body 1. In this case, among the high-pressure turbocharger 12 and the low-pressure turbocharger 13 constituting the multi-stage turbocharger, a plurality of high-pressure turbochargers 12 may be provided, or a plurality of low-pressure turbochargers 13 may be provided. It may be provided or it may be a combination thereof.

Further, in the above-described embodiment, as an example of the distribution pipe for circulating the exhaust gas from the high-pressure stage turbine 12a to the low-pressure stage turbine 13a, the exhaust pipe 112 which is a telescopic pipe and the low-pressure stage turbine 13
Although a distribution pipe configured by connecting an exhaust pipe 113 which is an end portion on the gas inlet side of the casing of a is illustrated, the present invention is not limited thereto. For example, the flow pipe may not be provided with a telescopic pipe, and in this case, the gas inlet portion of the exhaust pipe 113 may be connected to the gas outlet portion of the casing 12d of the high-pressure stage turbine 12a. Further, the distribution pipe has two exhaust pipes 112.
, 113 is not limited to, and may be composed of a single exhaust pipe or may be composed of a plurality of (two or more) exhaust pipes.

Further, in the above-described embodiment, the pipe on the high-pressure stage turbine 12a side in the distribution pipe is a telescopic pipe, but the present invention is not limited to this. In the present invention, the pipe (for example, the exhaust pipe 113) on the low pressure stage turbine 13a side in the distribution pipe may be an expansion / contraction pipe.

Further, in the above-described embodiment, the gas inlet portion of the exhaust pipe 111 that circulates the exhaust gas from the engine body 1 to the high-pressure stage turbine 12a is connected to the exhaust manifold 8, but the present invention is limited to this. It's not a thing. For example, the gas inlet portion of the exhaust pipe 111 may be connected to each cylinder of the engine body 1 without passing through the exhaust manifold 8. In this case, the engine body 1 does not have to include the exhaust manifold 8.

Further, in the above-described embodiment, the air (fresh air) sucked from the outside is used as the combustion gas, but the present invention is not limited to this. For example, an EGR system that recirculates a part of the exhaust gas from the engine body 1 to the engine body 1 is further provided, and this EGR is provided.
The mixed gas of the recirculated gas by the system and the air from the outside may be used as the combustion gas.

Further, the present invention is not limited to the above-described embodiment, and the present invention also includes a configuration in which the above-mentioned components are appropriately combined. In addition, other embodiments, examples, operational techniques, and the like made by those skilled in the art based on the above-described embodiments are all included in the scope of the present invention.

1 Engine body 2 Base plate 3 Frame 4 Cylinder jacket 5 Cylinder liner 6 Cylinder cover 7 Sweeping trunk 8 Exhaust manifold 10 Marine diesel engine 11 Two-stage turbocharger 12 High-pressure stage turbocharger 12a High-pressure stage turbine 12b High-pressure stage compressor 12c , 13c Rotating shaft 12d Casing 13 Low pressure stage turbocharger 13a Low pressure stage turbocharger 13b Low pressure stage compressor 13d Turbine nozzle 14 Silencer 15 Intermediate cooler 16 Cooler 101, 102, 103 Air supply pipe 111, 112, 113, 114 Exhaust pipe C1 , C2 Central axis D1 Rotation axis direction D2 Output axis direction D11 Height direction D12 Width direction

Claims (8)

The engine body that burns fuel and outputs the propulsive force of the ship from the output shaft,
A first turbocharger having a radial turbine that rotates by receiving the exhaust gas discharged from the engine body, and
A second supercharger having an axial flow turbine arranged so as to face the radial turbine in the rotation axis direction of the radial turbine and rotating by receiving the exhaust gas sent from the radial turbine.
A distribution pipe arranged between the radial turbine and the axial flow turbine to circulate the exhaust gas from the radial turbine to the axial flow turbine.
A first cooler that cools the combustion gas compressed by the compressor of the second turbocharger, and
A second cooler for cooling the combustion gas further compressed by the compressor of the first turbocharger, and a second cooler.
Equipped with
The engine body includes an exhaust manifold and has an exhaust manifold.
The first cooler and the second cooler are arranged side by side in the longitudinal direction of the output shaft of the engine body.
The first turbocharger, the second turbocharger, and the flow pipe are located between the exhaust manifold and the first cooler and the second cooler in the height direction of the engine body. A marine diesel engine characterized by being located in. The marine diesel engine according to claim 1, further comprising an exhaust pipe for discharging the exhaust gas in the radial direction of the radial turbine from the engine body toward the radial turbine. The marine diesel engine according to claim 1 or 2, wherein the rotary shaft of the radial turbine and the rotary shaft of the axial flow turbine are located on the same shaft. The marine diesel according to any one of claims 1 to 3, wherein the rotating shaft of the radial turbine and the rotating shaft of the axial flow turbine are parallel to the output shaft of the engine body. engine. Claims 1 to 4, wherein the second turbocharger is arranged above the first cooler, and the first turbocharger is arranged above the second cooler. The marine diesel engine described in any one of. Any of claims 1 to 5, wherein the first supercharger and the second supercharger are arranged below the exhaust manifold in the height direction of the engine body. The marine diesel engine described in one. The marine diesel engine according to any one of claims 1 to 6, wherein the distribution pipe includes a telescopic pipe that can be expanded and contracted in the direction of the rotation axis. The marine diesel engine according to any one of claims 1 to 7, wherein the second supercharger is a supercharger having a larger size than the first supercharger.

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