JP5965019B1 - Fuel supply device - Google Patents

Abstract

The present invention efficiently recovers exhaust gas energy of a diesel engine when an exhaust gas recirculation device is stopped. A diesel engine, an exhaust gas recirculation device that compresses a part of the exhaust of the diesel engine and then supplies the air to an intake pipe of the diesel engine, and a supercharger that compresses the air that is driven by the exhaust and is supplied to the diesel engine The exhaust control unit is configured to recirculate exhaust gas in a power unit having a compressor, an exhaust energy recovery device that recovers energy from the exhaust, and an exhaust control unit that adjusts the supply amount of exhaust gas to the supercharger and the exhaust gas recirculation device When the supply of exhaust gas to the apparatus is stopped, driving of the exhaust energy recovery apparatus is started. [Selection] Figure 1

Description

  The present invention relates to a fuel supply device that supplies fuel gas to a diesel engine mounted on a ship.

In Annex VI of the Marine Pollution Control Convention adopted by the International Maritime Organization (IMO) and entered into force in 2005, requirements for the prevention of air pollution of diesel engines with an output of 130 kW or more (NOx emissions, SOx emissions etc.) are defined. These regulations are planned to be strengthened every five years after the Annex comes into effect. The second regulation (Tier II) from 2011 was adopted and the third regulation (IMO Tier III) from 2016 was adopted. ing. Tier III applies to ships built on or after January 1, 2016.
In Tier III, nitrogen oxides (NOx) in the exhaust gas are regulated for each engine speed. The regulation value is determined as a function of the rated rotational speed (rpm) of the engine per minute, and the regulation value of the engine that rotates at a low speed becomes high.

In general, the NOx emission is determined by the reaction rate of nitrogen and oxygen. When the reaction rate is large, the NOx emission amount becomes large. Since the reaction rate increases as the temperature rises, NOx emissions can be reduced by lowering the combustion temperature of the engine.
For this reason, part of the engine exhaust gas is taken into the intake air and supplied to the combustion chamber, thereby reducing the ratio of compressed air, thereby lowering the combustion temperature and lowering the combustion speed. An EGR (Exhaust Gas Recirculation) device that reduces NOx emissions has been proposed (see, for example, Patent Document 1).

  By the way, in a supercharger that sends compressed air to a combustion chamber of a diesel engine, a compressor that sucks and compresses outside air is driven by rotating a turbine with exhaust from the engine. However, when the engine load is high, the energy of the exhaust becomes larger than the energy required to compress the intake air, which is wasted. Thus, it has been proposed to recover surplus energy of the exhaust gas by driving the hydraulic pump with a force that rotates the turbine of the supercharger (see, for example, Patent Document 2).

JP 2012-47056 A JP 2011-214458 A

  Since the NOx emission restriction is determined by the engine speed, the EGR device may not be used depending on the engine speed. Further, for the time being, Tier III is applied only to the designated NOxECA (Emission Control Area), and Tier II is applied to other sea areas. For this reason, the EGR device may not be used outside the NOxECA. Further, in the sea area outside the NOxECA, since the engine output is increased, the exhaust energy becomes larger than the energy used for driving the compressor in the supercharger, and thus the intake air is excessively compressed. On the other hand, if part of the exhaust gas is discharged to the outside without being supplied to the supercharger to prevent this, the energy of the exhaust gas is wasted.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to efficiently recover the energy of exhaust gas from a diesel engine when the exhaust gas recirculation device is stopped, and effectively use the recovered energy. It is to provide a power unit that can be used.

In order to solve the above problems, a first aspect of the present invention is a power plant,
A diesel engine,
A turbocharger that is driven by the exhaust of the diesel engine and compresses the air supplied to the diesel engine;
An exhaust gas recirculation device that compresses the exhaust gas when the exhaust gas is supplied and then supplies the exhaust gas to an intake pipe of the diesel engine;
An exhaust energy recovery device that recovers the energy of the exhaust and supplies the recovered energy to a load device;
A load device that uses the energy recovered by the exhaust energy recovery device;
An exhaust control unit for adjusting a supply amount of the exhaust gas to the supercharger and the exhaust gas recirculation device;
Have
When the exhaust control unit decreases the supply of exhaust gas to the exhaust gas recirculation device, increases the amount of exhaust gas supplied to the supercharger and increases the supply of exhaust gas to the exhaust gas recirculation device Further, the amount of exhaust gas supplied to the supercharger is reduced.

When the exhaust control unit stops supplying exhaust gas to the exhaust gas recirculation device, driving of the exhaust energy recovery device may be started.
The exhaust energy recovery device may be stopped when the exhaust control unit starts to supply exhaust gas to the exhaust gas recirculation device.

The supercharger is
A turbine driven by the exhaust;
A compressor driven by the turbine and compressing the air;
The exhaust energy recovery device includes:
It is preferable that the exhaust control unit includes an auxiliary drive device that assists in driving the compressor when the exhaust gas is supplied to the exhaust gas recirculation device.

  The exhaust energy recovery device may be a generator driven by the supercharger.

The exhaust energy recovery device includes a hydraulic pump driven by the supercharger,
The load device may be a first hydraulic motor that is driven by hydraulic oil boosted by the hydraulic pump and assists in driving the diesel engine.

The exhaust energy recovery device includes a hydraulic pump driven by the supercharger,
A second hydraulic motor driven by hydraulic oil boosted by the hydraulic pump;
And a generator driven by the second hydraulic motor.

A second aspect of the present invention is a power plant,
A diesel engine,
A first supercharger that is driven by the exhaust of the diesel engine and compresses air supplied to the diesel engine;
An exhaust gas recirculation device that compresses the exhaust gas when the exhaust gas is supplied and then supplies the exhaust gas to an intake pipe of the diesel engine;
A second supercharger that is driven by the exhaust when the exhaust is not supplied to the exhaust recirculation device, compresses air and supplies it to the diesel engine through the exhaust recirculation device;
An exhaust energy recovery device that is driven by the second supercharger and recovers energy from the exhaust;
A load device that uses the energy recovered by the exhaust energy recovery device;
An exhaust control unit for adjusting a supply amount of the exhaust gas to the second supercharger and the exhaust gas recirculation device;
Have
The exhaust control unit increases the amount of exhaust gas supplied to the second supercharger when reducing the supply of exhaust gas to the exhaust gas recirculation device, and supplies the exhaust gas to the exhaust gas recirculation device. When increasing, the amount of exhaust gas supplied to the second supercharger is reduced.

When the exhaust control unit stops supplying exhaust gas to the exhaust gas recirculation device, driving of the exhaust energy recovery device may be started.
The exhaust energy recovery device may be stopped when the exhaust control unit starts to supply exhaust gas to the exhaust gas recirculation device.

The second supercharger is
A turbine driven by the exhaust;
A compressor driven by the turbine and compressing the air;
The exhaust energy recovery device includes:
It is preferable that the exhaust control unit includes an auxiliary drive device that assists in driving the compressor when the exhaust gas is supplied to the exhaust gas recirculation device.

  The exhaust energy recovery device may be a generator driven by the second supercharger.

The exhaust energy recovery device includes a hydraulic pump driven by the second supercharger;
A second hydraulic motor driven by hydraulic oil boosted by the hydraulic pump;
And a generator driven by the second hydraulic motor.

The exhaust gas recirculation device includes an exhaust compressor that compresses a part of the exhaust gas,
A third hydraulic motor that is driven by hydraulic pressure of the hydraulic oil and drives the exhaust compressor may be provided.

A fuel pump that pressurizes the fuel in the fuel tank and supplies the fuel to the diesel engine;
A fourth hydraulic motor driven by hydraulic oil pressure and driving the fuel pump may be further provided.

A fuel valve for injecting fuel into the combustion chamber of the diesel engine;
An exhaust valve for discharging the gas in the combustion chamber;
A hydraulic control unit that controls opening and closing of the fuel valve and the exhaust valve by hydraulic pressure of hydraulic oil;
May be provided.

  ADVANTAGE OF THE INVENTION According to this invention, the energy of the exhaust_gas | exhaustion of a diesel engine can be collect | recovered efficiently at the time of a stop of an exhaust gas recirculation apparatus, and the collect | recovered energy can be utilized effectively.

It is a block diagram showing the whole power unit composition of a 1st embodiment of the present invention. 1 is a block diagram of a fuel supply device 10 according to a first embodiment. It is a block diagram of main engine 20, exhaust control part 90A, supercharger 40A, and exhaust energy recovery device 70A concerning a 1st embodiment. It is a block diagram of 50 A of exhaust gas recirculation apparatuses which concern on 1st Embodiment. It is a block diagram of exhaust energy recovery device 70A concerning a 1st embodiment. It is a block diagram which shows the whole structure of the power plant of 2nd Embodiment of this invention. It is a block diagram of the main engine 20, the exhaust control part 90B, and the supercharger 40A which concern on 2nd Embodiment. FIG. 7 is a block diagram of an exhaust gas recirculation device 50B, an exhaust control unit 90B, a supercharger 40B, and an exhaust energy recovery device 70B according to a second embodiment. FIG. 6 is a block diagram of a main engine 20, an exhaust control unit 90A, a supercharger 40A, a turbine 42C, and an exhaust energy recovery device 70C according to a modification of the first embodiment.

Hereinafter, an outline of a power plant according to an embodiment of the present invention will be described.
[First Embodiment]
FIG. 1 is a block diagram showing the overall configuration of the power plant according to the first embodiment. The power plant according to the first embodiment includes a fuel supply device 10, a main engine 20, a supercharger 40A, an exhaust control unit 90A, an exhaust gas recirculation device 50A, an exhaust energy recovery device 70A, a load device (not shown), and the like. All the components of the power plant are mounted on the ship.

The fuel supply device 10 supplies fuel to the main engine 20.
The main engine 20 includes an internal combustion engine (diesel engine) that burns fuel supplied from the fuel supply device 10 together with compressed air supplied from the supercharger 40A. Exhaust gas discharged from the internal combustion engine is discharged to the exhaust control unit 90A.
The supercharger 40A includes a turbine driven by the exhaust supplied from the exhaust control unit 90A, and a compressor driven by the turbine to compress outside air and supply the compressed air to the internal combustion engine.
The exhaust gas recirculation device 50A purifies the exhaust gas supplied from the exhaust gas control unit 90A, compresses it, and supplies it to the internal combustion engine of the main engine 20.
The exhaust energy recovery device 70A recovers this surplus energy as oil pressure or electric power when the power obtained from the exhaust of the turbine of the supercharger 40A is larger than the energy required to drive the compressor, and this recovered energy Supply to the load device to use. The load device is, for example, an auxiliary drive device that assists in driving the diesel engine, a fuel pump 12 used in the fuel supply device 10, a motor 65 that drives the exhaust compressor 64 by the exhaust gas recirculation device 50A, or the like.

  The exhaust control unit 90A supplies part or all of the exhaust from the main engine 20 to the supercharger 40A, and also drives the other part of the exhaust to the exhaust recirculation device 50A when driving the exhaust recirculation device 50A. Supply. In this case, when the exhaust control unit 90A decreases the supply of exhaust gas to the exhaust gas recirculation device 50A, the exhaust control unit 90A increases the amount of exhaust gas supplied to the supercharger 40A and supplies the exhaust gas to the exhaust gas recirculation device 50A. When increasing, it adjusts so that the quantity of the exhaust_gas | exhaustion supplied to 40 A of superchargers may be decreased.

In the present embodiment, even when the exhaust gas is supplied to the exhaust gas recirculation device 50A as much as possible, the remaining exhaust gas can provide sufficient power to drive the compressor from the turbine of the supercharger 40A. A compressor is selected.
In this case, when stopping the exhaust gas recirculation device 50A or reducing the amount of exhaust gas supplied to the exhaust gas recirculation device 50A, if all the exhaust gas is supplied to the supercharger, the compressed air is excessively supplied to the internal combustion engine. Will be. For this reason, conventionally, excessive exhaust gas is discharged into the atmosphere without being supplied to the supercharger.
In contrast, in the present embodiment, when the exhaust gas recirculation device 50A is stopped or when the amount of exhaust gas supplied to the exhaust gas recirculation device 50A is reduced, the surplus exhaust energy is used as the exhaust energy recovery device 70A. Collect with. For this reason, the energy of the exhaust gas of the internal combustion engine can be efficiently recovered.
Hereinafter, each configuration of the fuel supply device 10, the main engine 20, the supercharger 40A, the exhaust control unit 90A, the exhaust gas recirculation device 50A, and the exhaust energy recovery device 70A will be described in detail.

[Fuel supply device]
FIG. 2 is a block diagram showing the fuel supply device 10. The fuel supply device 10 is a device that supplies fuel to the main engine 20. In the present embodiment, an apparatus for supplying high-pressure fuel obtained by heating liquid fuel will be described, but the present invention is not limited to this.
The fuel supply device 10 includes a liquid fuel tank 11, a fuel pump 12, a hydraulic motor 13, a heat exchanger 14, and the like.

The liquid fuel tank 11 stores liquid fuel before the fuel supplied to the main engine 20 is vaporized. As the liquid fuel, liquefied natural gas (LNG), liquefied petroleum gas (LPG), or the like can be used. In the following description, the case where LNG is used as the liquid fuel will be described as an example.
The pressure in the liquid fuel tank 11 is, for example, about 0.1 MPa (atmospheric pressure). When the liquid fuel is LNG, its temperature is about -160 ° C.
The lower end of the liquid fuel tank 11 is connected to the fuel pump 12 by a pipe 15.

The fuel pump 12 is connected to the lower end of the liquid fuel tank 11 by a pipe 15 and is connected to the heat exchanger 14 by a pipe 16. The fuel pump 12 is driven by a hydraulic motor 13 to increase the pressure of the liquid fuel in the liquid fuel tank 11 and send it to the heat exchanger 14.
As the fuel pump 12, for example, a reciprocating pump of a type in which the movable portion reciprocates can be used. In this case, the rotational motion of the hydraulic motor 13 that drives the fuel pump 12 is converted into a reciprocating motion of the movable portion by, for example, a crank mechanism (not shown).
The rotational speed of the fuel pump 12 is controlled so that the pressure of the fuel supplied to the main engine 20 is constant.

  The heat exchanger 14 heats the liquid fuel delivered from the fuel pump 12. As the heat exchanger 14, for example, a multi-tube cylindrical heat exchanger can be used. Hot water can be used as a heat source. The fuel heated by the heat exchanger 14 is supplied to the main engine 20 shown in FIG. In addition, when the fuel pump 12 compresses and sends out the heated fuel, the heat exchanger 14 is unnecessary.

  The hydraulic motor 13 is connected to a high hydraulic pipe 1 whose internal hydraulic pressure is relatively high and a low hydraulic pipe 2 whose internal hydraulic pressure is lower than the hydraulic pressure inside the high hydraulic pipe 1. Here, the high hydraulic piping 1 and the low hydraulic piping 2 are used for controlling the hydraulic drive mechanism in common with the fuel supply device 10, the main engine 20, the exhaust gas recirculation device 50A, and the exhaust energy recovery device 70A. The hydraulic motor 13 rotates using the hydraulic pressure difference (differential pressure) between the high hydraulic pipe 1 and the low hydraulic pipe 2 to drive the fuel pump 12. The hydraulic motor 13 is a variable capacity type, and the rotation speed of the hydraulic motor 13 is adjusted according to the pressure of the liquid fuel in the pipe 16. The pipe 17 is provided with a pressure gauge (not shown) that measures the pressure of the liquid fuel in the pipe 16, and the rotational speed of the hydraulic motor 13 is adjusted based on the measurement result of the pressure gauge.

FIG. 3 is a block diagram showing the main engine 20, the exhaust control unit 90A, and the supercharger 40A.
[Main engine]
The main engine 20 includes an internal combustion engine 21, a pilot fuel valve 22, a gas fuel valve 23, a gas control unit 24, an intake manifold 25, an exhaust valve 26, a cooler 30, and the like.
The internal combustion engine 21 is an engine that uses an alternative fuel such as methanol or natural gas. For example, a low-speed diesel engine having a two-stroke cycle cylinder can be used. The internal combustion engine 21 rotates a main shaft 100 that is a power source of a ship.
The pilot fuel valve 22 is a fuel valve that injects pilot fuel into the combustion chamber of the internal combustion engine 21 when the internal combustion engine 21 is started. The opening and closing of the pilot fuel valve 22 is controlled by the hydraulic control unit 8.
The gas fuel valve 23 is a fuel valve that injects fuel supplied from the fuel supply device 10 into the combustion chamber of the internal combustion engine 21. The opening and closing of the gas fuel valve 23 is controlled by the hydraulic control unit 8.
The gas control unit 24 has an original valve for fuel supplied from the fuel supply device 10 through the pipe 17, and controls the supply of fuel to the gas fuel valve 23.

  The intake manifold 25 is connected to the supercharger 40A by the intake pipe 32, is connected to the combustion chamber of the internal combustion engine 21 by the intake pipe 33, and is connected to the exhaust gas recirculation device 50A shown in FIG. The intake manifold 25 mixes the compressed air supplied from the intake pipe 32 and the exhaust supplied from the exhaust circulation pipe 53, stores the obtained mixed gas, and supplies it to the combustion chamber of the internal combustion engine 21 through the intake pipe 33. To do.

The exhaust valve 26 is connected to the combustion chamber of the internal combustion engine 21 by the exhaust pipe 34 and is connected to the exhaust receiver 91 by the exhaust pipe 35. The exhaust valve 26 is a valve for discharging the gas in the combustion chamber of the internal combustion engine 21. The opening and closing of the exhaust valve 26 is controlled by the hydraulic control unit 8.
The hydraulic control unit 8 performs opening / closing control of the pilot fuel valve 22, the gas fuel valve 23, and the exhaust valve 26 using the differential pressure between the high hydraulic pipe 1 and the low hydraulic pipe 2. The differential pressure between the high hydraulic pipe 1 and the low hydraulic pipe 2 is increased by the hydraulic pump 3. The hydraulic pump 3 is connected to a transmission 101 provided on the main shaft 100. As the main shaft 100 rotates, the hydraulic pump 3 is driven to increase the differential pressure between the high hydraulic pipe 1 and the low hydraulic pipe 2.

  The cooler 30 cools the compressed air passing through the intake pipe 32. The compressed air passing through the intake pipe 32 is heated to a high temperature by being adiabatically compressed by the compressor 41. By performing heat exchange between the compressed air and a refrigerant (for example, seawater) passing through the cooler 30, the compressed air in the intake pipe 32 is cooled. As the cooler 30, for example, a multi-tube cylindrical heat exchanger can be used.

[Exhaust control unit]
The exhaust control unit 90A includes an exhaust receiver 91, a bypass valve 92, a bypass exhaust valve 93, an on-off valve 94, and the like.
The exhaust receiver 91 is connected to the exhaust valve 26 through the exhaust pipe 35, connected to the supercharger 40 </ b> A through the exhaust pipe 37, and connected to the exhaust gas recirculation device 50 </ b> A through the exhaust circulation pipe 51. The exhaust receiver 91 stores the exhaust discharged from the combustion chamber of the internal combustion engine 21.
The exhaust receiver 91 is connected to the intake pipe 32 by a bypass pipe 36. A bypass valve 92 is provided in the bypass pipe 36. The opening degree of the bypass valve 92 is adjusted based on the pressure in the intake manifold 25. For example, when the exhaust gas recirculation device 50 </ b> A is not driven, the bypass valve 92 is opened to discharge the compressed air in the intake pipe 32 to the exhaust receiver 91 in order to prevent the pressure in the intake manifold 25 from rising excessively.
The exhaust receiver 91 is connected to the exhaust pipe 38 by a bypass exhaust pipe 39. A bypass exhaust valve 93 is provided in the bypass exhaust pipe 39. The opening degree of the bypass exhaust valve 93 is adjusted based on the pressure in the intake manifold 25. For example, when the exhaust gas recirculation device 50A is not driven, the bypass exhaust valve 93 is opened in order to prevent the turbine 42 from excessively rotating due to exhaust gas and excessively supplying compressed air into the intake manifold 25 by the compressor 41. The exhaust in the exhaust receiver 91 is exhausted from the exhaust pipe 38 to the outside through the bypass exhaust pipe 39.
The on-off valve 94 is provided in the exhaust circulation pipe 51. Exhaust gas is supplied to the exhaust gas recirculation device 50A by opening the on-off valve 94, and supply of exhaust gas to the exhaust gas recirculation device 50A is stopped by closing the on-off valve 94.
In the exhaust control unit 90A, opening and closing of the bypass valves 92 and 93 and the on-off valve 94 is controlled by a control unit (not shown).

[Supercharger]
The supercharger 40A includes a compressor 41A, a turbine 42A, and a rotating shaft 43A. The compressor 41A is connected to the intake pipes 31 and 32. The compressor 41A sucks outside air from the intake pipe 31 and compresses it. The intake pipe 32 passes through the cooler 30, and outside air (compressed air) compressed by the compressor 41 </ b> A is cooled by the cooler 30 and then supplied to the intake manifold 25 through the intake pipe 32.
The turbine 42 </ b> A is connected to the exhaust pipes 35 and 37. The turbine 42 </ b> A rotates by receiving the exhaust supplied from the exhaust pipe 35. The exhaust gas that has rotated the turbine 42 </ b> A is discharged to the outside through the exhaust pipe 37.
The rotating shaft 43A transmits the rotation of the turbine 42A to the compressor 41A and drives the compressor 41A. The rotating shaft 43A is connected to the hydraulic pump 73 of the exhaust energy recovery device 70A shown in FIG. 5 and transmits the rotation of the turbine 42A to the hydraulic pump 73.

[Exhaust gas recirculation system]
FIG. 4 is a block diagram showing the exhaust gas recirculation device 50A. The exhaust gas recirculation device 50A includes an on-off valve 94, a dust collector 62, a cooler 63, an exhaust compressor 64, a motor 65, and the like.
The dust collector 62 is connected to the exhaust circulation pipe 51 and the exhaust circulation pipe 52 and removes environmental pollutants in the exhaust gas supplied from the exhaust circulation pipe 51. For example, in the dust collector 62, sulfur oxides in the exhaust gas are neutralized and removed with sodium hydroxide mixed water. The exhaust gas from which environmental pollutants have been removed is discharged to the exhaust circulation pipe 52.
The cooler 63 cools the exhaust in the exhaust circulation pipe 52 by exchanging heat between the exhaust passing through the exhaust circulation pipe 52 and a refrigerant (for example, seawater) passing through the cooler 63. As the cooler 30, for example, a multi-tube cylindrical heat exchanger can be used.
The exhaust compressor 64 is connected to the exhaust circulation pipe 52 and the exhaust circulation pipe 53 and compresses exhaust gas supplied from the exhaust circulation pipe 52. The compressed exhaust gas is supplied to the intake manifold 25 of FIG.
The exhaust compressor 64 is driven by a motor 65. The rotational speed of the motor 65 is adjusted according to the oxygen concentration in the intake manifold 25. The intake manifold 25 is provided with an oxygen concentration meter (not shown) that measures the oxygen concentration in the intake manifold 25, and the number of revolutions of the motor 65 is adjusted based on the measurement result of the oxygen concentration meter. The exhaust gas recirculation device 50 </ b> A is driven by driving the motor 65 with the on-off valve 94 opened, and exhaust gas is supplied to the intake manifold 25 through the exhaust gas circulation pipes 51 to 53.
Instead of the motor 65, the exhaust compressor 64 may be driven using a variable displacement hydraulic motor that rotates using a differential pressure between the high hydraulic pipe 1 and the low hydraulic pipe 2. Further, a plurality of dust collectors may be provided in the front stage of the exhaust compressor 64. In this case, the cooler 63 can be provided at an arbitrary position. In addition, by providing a dust collector in the subsequent stage of the cooler 63, it is possible to further remove environmental pollutants in the cooled exhaust gas.
Further, in parallel with the exhaust compressor 64, one or a plurality of other exhaust compressors that supply exhaust gas from which environmental pollutants have been removed by the dust collector 62 to the intake manifold 25 may be provided.

[Exhaust energy recovery system]
The exhaust energy recovery device 70A includes a speed reducer 71, a rotary shaft 72, hydraulic pumps 73 and 74, a hydraulic motor 75, an on-off valve 76, a generator 77, and the like.
The speed reducer 71 is attached to the rotation shaft 43A of the supercharger 40A in FIG. 3 and transmits the rotation speed of the rotation shaft 43A to the rotation shaft 72 as appropriate.

  The hydraulic pump 73 is connected to the hydraulic pipe 81 and the hydraulic pipe 82. The hydraulic pump 73 is driven by the rotation of the rotary shaft 72 and sends hydraulic oil from the hydraulic pipe 82 to the hydraulic pipe 81. The hydraulic pipe 81 may be connected to the high hydraulic pipe 1 and the hydraulic pipe 82 may be connected to the low hydraulic pipe 2.

  The hydraulic pump 74 is connected to the hydraulic pipe 81 and the hydraulic pipe 82, and is connected to the main shaft 100 via a transmission (not shown). The hydraulic pump 74 is driven by the rotation of the main shaft 100 and sends hydraulic oil from the hydraulic pipe 82 to the hydraulic pipe 81. The hydraulic pump 74 is a variable displacement pump. The hydraulic pump 74 may be used as a hydraulic motor that assists the rotation of the main shaft 100. Further, the hydraulic pump 74 may be arranged side by side with the hydraulic pump 3 of the main engine 20.

The hydraulic motor 75 is connected to the hydraulic pipe 83 and the hydraulic pipe 84. The hydraulic pipe 83 is connected to the hydraulic pipe 81, and the hydraulic pipe 84 is connected to the hydraulic pipe 82. The hydraulic motor 75 is driven by a differential pressure between the hydraulic pipe 83 and the hydraulic pipe 84.
A bypass pipe 85 is provided between the hydraulic pipe 81 and the hydraulic pipe 82 to connect them. The on-off valve 76 is provided in the bypass pipe 85.
The generator 77 is driven by a hydraulic motor 75 and converts the rotational force of the hydraulic motor 75 into electric power. For example, the power generated by the generator 77 may be charged in a secondary battery (not shown) and used to drive the motor 65 of the exhaust gas recirculation device 50A. Further, the generator 77 may be used as an electric motor, and the hydraulic motor 75 may be used as a hydraulic pump.

In the present embodiment, when the exhaust gas recirculation device 50A is being driven, the exhaust energy recovery by the exhaust energy recovery device 70A may be stopped.
Specifically, when the on-off valve 94 of the exhaust gas recirculation device 50A is opened and the motor 65 is driven, the on-off valve 76 is opened so that no pressure difference is generated between the hydraulic pipe 81 and the hydraulic pipe 82. To do. The power transmission from the rotating shaft 43 to the rotating shaft 72 by the speed reducer 71 may be canceled. Further, power transmission from the main shaft 100 to the hydraulic pump 74 may be canceled.

On the other hand, when the exhaust gas recirculation device 50A is stopped, the energy obtained from the exhaust gas by the turbine 42 is recovered by the exhaust energy recovery device 70A.
Specifically, when the driving of the exhaust gas recirculation device 50A is stopped by closing the open / close valve 94 of the exhaust gas recirculation device 50A and stopping the motor 65, the open / close valve 76 is closed and the hydraulic pump 73 is driven. A pressure difference is generated between the hydraulic pipe 81 and the hydraulic pipe 82. Then, the hydraulic motor 75 is driven and the generator 77 is driven. Thereby, the energy of the exhaust is recovered as electric power.

  The faster the boat speed and the greater the load on the internal combustion engine 21, the greater the amount of exhaust from the internal combustion engine 21. On the other hand, the emission regulation region to which Tier III is applied is the near sea, and it is not necessary to drive the exhaust gas recirculation device 50A in the open ocean that navigates at a high boat speed. For this reason, especially in the open ocean, when the exhaust gas recirculation device 50 </ b> A is stopped, the energy obtained from the exhaust gas by the turbine 42 becomes very large compared to the energy used to drive the compressor 41. In the present embodiment, when the exhaust gas recirculation device 50A is stopped, the exhaust energy recovery device 70A is driven, and excess energy is recovered by the exhaust energy recovery device 70A, thereby effectively using the recovered energy. Can do.

In selecting the supercharger 40A, power sufficient to drive the compressor 41 when the turbine 42 is rotated by all exhaust gas in a state where the exhaust gas from the internal combustion engine 21 is not supplied to the exhaust gas recirculation device 50A. So that the compressor 41 and the turbine 42 may be selected.
In this case, when the exhaust gas recirculation device 50A is driven, sufficient power to drive the compressor 41 can be obtained even if the turbine 42 is rotated by the remaining exhaust gas supplied to the exhaust gas recirculation device 50A. I can't. Therefore, the hydraulic pump 73 can be used as an auxiliary drive device that assists in driving the compressor 41. In other words, the drive of the compressor 41 can be assisted by using the hydraulic pump 73 as a hydraulic motor driven by the differential pressure between the hydraulic pipe 81 and the hydraulic pipe 82.

Further, in selecting the supercharger 40A, when the amount of exhaust gas supplied to the exhaust gas recirculation device 50A is set to a predetermined reference amount smaller than the maximum amount, the turbine 42 is rotated by the remaining exhaust gas, and the compressor 41 is turned on. The compressor 41 and the turbine 42 may be selected so as to obtain sufficient power for driving.
In this case, when exhaust gas less than the reference amount is supplied to the exhaust gas recirculation device 50A, the energy obtained from the exhaust gas by the turbine 42 becomes larger than the energy used for driving the compressor 41, and the exhaust gas is exhausted by the hydraulic pump 73. The hydraulic oil pressure can be increased when the recirculation device 50A is stopped. On the other hand, when exhaust gas larger than the reference amount is supplied to the exhaust gas recirculation device 50A, sufficient power to drive the compressor 41 even if the turbine 42 is rotated by the remaining exhaust gas supplied to the exhaust gas recirculation device 50A. Cannot be obtained. Therefore, the drive of the compressor 41 can be assisted by using the hydraulic pump 73 as a hydraulic motor.

  Further, the hydraulic pump 73 may be used to increase the hydraulic pressure difference of the hydraulic oil between the high hydraulic pipe 1 and the low hydraulic pipe 2. Thereby, the energy recovered from the exhaust can be used in the fuel pump 12 and the hydraulic control unit 8.

  In the exhaust energy recovery device 70A, instead of driving the generator 77 via the hydraulic pump 74 and the hydraulic motor 75, the rotary shaft 72 is directly connected to the generator 77, and the generator 77 is driven by the rotation of the rotary shaft 43A. May be.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and description is omitted.
FIG. 6 is a block diagram showing the overall configuration of the power plant according to the second embodiment. The power plant according to the second embodiment includes a fuel supply device 10, a main engine 20B, superchargers 40A and 40B, an exhaust gas recirculation device 50B, an exhaust energy recovery device 70B, an exhaust control unit 90B, and the like. The second embodiment is different from the first embodiment in that the exhaust energy recovery device 70B is connected to the supercharger 40A instead of the supercharger 40A.
In the second embodiment, the exhaust control unit 90B supplies a part of the exhaust from the main engine 20 to the supercharger 40A and supplies the other part of the exhaust to the exhaust gas recirculation device 50B or the supercharger 40B. To do. In this case, when the exhaust control unit 90B decreases the supply of exhaust gas to the exhaust gas recirculation device 50B, the exhaust control unit 90B increases the amount of exhaust gas supplied to the supercharger 40B and supplies the exhaust gas to the exhaust gas recirculation device 50B. When increasing, it adjusts so that the quantity of the exhaust_gas | exhaustion supplied to the supercharger 40B may be decreased.
The supercharger 40B includes a turbine driven by the exhaust supplied from the exhaust control unit 90B, and a compressor driven by the turbine to compress outside air and supply the compressed air to the exhaust gas recirculation device 50B.
The exhaust gas recirculation device 50B purifies the exhaust gas supplied from the exhaust gas control unit 90B, compresses it, and supplies it to the internal combustion engine of the main engine 20. Further, the exhaust gas recirculation device 50 </ b> B supplies the compressed air supplied from the supercharger 40 </ b> B to the internal combustion engine of the main engine 20.

FIG. 7 is a block diagram showing the main engine 20, the exhaust control unit 90B, and the supercharger 40A of the second embodiment. Also in the second embodiment, a supercharger 40A similar to that in the first embodiment is provided. However, the point that the exhaust energy recovery device 70A is not connected to the supercharger 40A of the second embodiment is different from the first embodiment.
The exhaust receiver 91 of the second embodiment is connected to the exhaust gas recirculation device 50 </ b> B through the exhaust pipe 56 together with the exhaust circulation pipe 51. A part of the exhaust discharged from the exhaust receiver 91 is supplied from the exhaust circulation pipe 51 or the exhaust pipe 56 to the exhaust gas recirculation device 50B shown in FIG.

  FIG. 8 is a block diagram showing the exhaust gas recirculation device 50B, the exhaust control unit 90B, the supercharger 40B, and the exhaust energy recovery device 70B of the second embodiment. The exhaust gas recirculation device 50B according to the second embodiment includes exhaust pipes 56 and 57, intake pipes 58 and 59, and the like in addition to the configuration of the exhaust gas recirculation device 50A according to the first embodiment. Further, the exhaust control unit 90B of the second embodiment includes on-off valves 95 and 96 in addition to the exhaust control unit 90A of the first embodiment.

The supercharger 40B includes a compressor 41B, a turbine 42B, and a rotating shaft 43B. The supercharger 40B may have the same capacity as the supercharger 40A or may have a capacity smaller than that of the supercharger 40A. The compressor 41B is connected to the intake pipes 58 and 59. The turbine 42B is connected to the exhaust pipes 56 and 57. The rotating shaft 43B transmits the rotation of the turbine 42B to the compressor 41B and drives the compressor 41B. The rotating shaft 43B is connected to the hydraulic pump 73 of the exhaust energy recovery device 70B similar to that shown in FIG. 5, and transmits the rotation of the turbine 42B to the hydraulic pump 73 of the exhaust energy recovery device 70B.
The exhaust pipe 56 is provided with an open / close valve 95, and the intake pipe 59 is provided with an open / close valve 96.

Next, operation | movement of the exhaust gas recirculation apparatus 50B of 2nd Embodiment is demonstrated.
When the exhaust gas recirculation device 50B is being driven, the open / close valve 94 is opened, the open / close valves 95 and 96 are closed, and the motor 65 is being driven. The operation at this time is the same as that when driving the exhaust gas recirculation device 50A of the first embodiment.

When stopping the driving of the exhaust gas recirculation device 50B, the on-off valve 94 is closed, the on-off valves 95 and 96 are opened, and the driving of the motor 65 is stopped. At this time, the exhaust from the exhaust receiver 91 is supplied to the turbine 42B through the exhaust pipe 56, rotates the turbine 42B, and is discharged from the exhaust pipe 57 to the outside.
On the other hand, the compressor 41 </ b> B driven by the turbine 42 </ b> B sucks outside air from the intake pipe 58, compresses it, and supplies it from the intake pipe 59 to the exhaust circulation pipe 52. The compressed air supplied to the exhaust circulation pipe 52 is cooled by the cooler 63 and then supplied to the intake manifold 25 via the exhaust circulation pipe 53. At this time, if necessary, the motor 65 drives the exhaust compressor 64 to further compress the compressed air and supply it to the intake manifold 25.
When the energy obtained from the exhaust by the turbine 42B is larger than the energy used to drive the compressor 41B, the rotation of the turbine 42B is transmitted to the exhaust energy recovery device 70B by the rotary shaft 43B, thereby the first As in the embodiment, exhaust energy is recovered.

Thus, in the second embodiment, whether the exhaust control unit 90B supplies and circulates part of the exhaust to the exhaust circulation pipes 51, 52, 53 by controlling the opening / closing of the on-off valves 94, 95, 96. Or switching to supply to the supercharger 40B and discharging, and driving the exhaust gas recirculation device 50B to stop the exhaust energy recovery device 70B, or stopping the exhaust gas recirculation device 50B and exhaust gas recovery device Whether to drive 70B can be switched.
Further, the exhaust control unit 90B adjusts the opening / closing of the on-off valves 94, 95, and 96 so that the exhaust gas to be recirculated and the compressed air supplied from the compressor 41B are mixed at a desired ratio and supplied to the intake manifold 25. can do.

  As in the first embodiment, an exhaust energy recovery device 70A different from the exhaust energy recovery device 70B of the supercharger 40B may be provided in the supercharger 40A of the main engine 20B of the second embodiment. Further, the exhaust energy recovery device 70A may be provided only in the supercharger 40A, and the exhaust energy recovery device 70B may not be provided in the supercharger 40B of the exhaust gas recirculation device 50B.

<Modification>
FIG. 9 is a block diagram of the main engine 20, the exhaust control unit 90A, the supercharger 40A, the turbine 42C, and the exhaust energy recovery device 70C according to a modification of the first embodiment. The configurations of the main engine 20, the exhaust control unit 90A, and the supercharger 40A are the same as those in the first embodiment shown in FIG.

In this modification, a turbine 42C is connected to bypass exhaust pipes 39a and 39b that connect the bypass exhaust valve 93 and the exhaust pipe 38. In this modification, instead of the exhaust energy recovery device 70A being attached to the rotating shaft 43A of the supercharger 40A, the exhaust energy recovery device 70C is attached to the rotating shaft 43C of the turbine 42C.
The turbine 42C is driven by the exhaust supplied from the bypass exhaust valve 93, and rotates the rotating shaft 43C. An exhaust energy recovery device 70C is attached to the rotation shaft 43C, and the rotation shaft 43C transmits the rotation of the turbine 42C to the exhaust energy recovery device 70C. Since the configuration of the exhaust energy recovery device 70C is the same as that of the exhaust energy recovery device 70A of the first embodiment, a description thereof will be omitted.

  Also in this modification, surplus exhaust is supplied to the turbine 42C to drive the supercharger 40A and the exhaust energy recovery device 70C is driven, so that surplus energy is exhausted to drive the supercharger 40A. The energy recovered by the energy recovery device 70C can be used effectively.

  In the above description, the case where the liquid fuel is LNG has been described. However, the present invention is not limited to this, and liquid fuel such as LPG may be used. Further, not only liquid fuel but also gas or solid fuel may be used. The hydraulic piping, valves, pumps, and the like in the above description are examples, and the present invention is not limited thereto.

DESCRIPTION OF SYMBOLS 1 High hydraulic piping 2 Low hydraulic piping 3, 73-74 Hydraulic pump 8 Hydraulic control unit 10 Fuel supply apparatus 11 Liquid fuel tank 12 Fuel pump 13, 75 Hydraulic motor 14 Heat exchanger 15-17 Piping 20A, 20B Main engine 21 Internal combustion Engine 22 Pilot fuel valve 23 Gas fuel valve 24 Gas control unit 25 Intake manifold 26 Exhaust valve 30 Cooler 31-33, 58-59 Intake pipe 34-35, 37-38, 56-57 Exhaust pipe 36 Bypass pipe 39 Bypass exhaust Pipe 40A, 40B Supercharger 41A, 41B Compressor 42A, 42B, 42C Turbine 43A, 43B, 43C Rotating shaft 50A, 50B Exhaust gas recirculation device 51-53 Exhaust gas circulation pipe 62 Dust collector 63 Cooler 64 Compressor 65 Motor 70A, 70B, 70C Exhaust energy recovery device 71 Reducer 72 Rotating shaft 76 On-off valve 7 Generator 81-84 hydraulic pipe 85 a bypass pipe 90A, 90B the exhaust control unit 91 exhaust receiver 92 bypass valve 93 bypassing the exhaust valve 94-96-off valve 100 the main shaft 101 transmission

Claims (9)

A diesel engine,
A first turbine that is driven by exhaust gas from the diesel engine, and a first turbocharger that is driven by the first turbine and includes a first compressor that compresses air supplied to the diesel engine;
An exhaust gas recirculation device that compresses the exhaust gas when the exhaust gas is supplied and then supplies the exhaust gas to an intake pipe of the diesel engine;
Of the exhaust of the diesel engine, the second turbine driven by surplus exhaust excluding the exhaust supplied to the first turbine and the exhaust gas recirculation device, and compressed by air driven by the second turbine A second supercharger comprising a second compressor for supplying to the diesel engine through the exhaust gas recirculation device;
An exhaust energy recovery device for recovering surplus energy exceeding energy for driving the second compressor from the energy of the second turbine and supplying the recovered energy to a load device;
An exhaust control unit for adjusting a supply amount of the exhaust gas to the second supercharger and the exhaust gas recirculation device;
Have
When the exhaust control unit decreases the supply of exhaust gas to the exhaust gas recirculation device, the amount of exhausted energy supplied by the exhaust energy recovery device is increased by increasing the amount of exhaust gas supplied to the second supercharger. When the supply of exhaust gas to the exhaust gas recirculation device is increased, the amount of exhaust gas supplied to the second supercharger is decreased to reduce the amount of energy recovered by the exhaust energy recovery device Let the power unit. Wherein when the exhaust control unit stops the supply of the exhaust gas to the exhaust gas recirculation device, it starts driving of the exhaust energy recovery apparatus, the power device according to claim 1. The power unit according to claim 1 or 2 , wherein when the exhaust control unit starts supplying exhaust gas to the exhaust gas recirculation device, driving of the exhaust energy recovery device is stopped. The exhaust energy recovery device includes:
The power plant according to any one of claims 1 to 3 , further comprising an auxiliary drive device that assists driving of the second compressor when the exhaust control unit supplies the exhaust gas to the exhaust gas recirculation device. . The power device according to any one of claims 1 to 4 , wherein the exhaust energy recovery device is a generator driven by the second supercharger. The exhaust energy recovery device includes a hydraulic pump driven by the second supercharger;
A second hydraulic motor driven by hydraulic oil boosted by the hydraulic pump;
The power unit according to any one of claims 1 to 5 , further comprising a generator driven by the second hydraulic motor. The exhaust gas recirculation device includes an exhaust compressor that compresses a part of the exhaust gas,
The power unit according to any one of claims 1 to 6 , further comprising a third hydraulic motor that is driven by hydraulic pressure of hydraulic oil and drives the exhaust compressor. A fuel pump that pressurizes the fuel in the fuel tank and supplies the fuel to the diesel engine;
The power plant according to any one of claims 1 to 7 , further comprising a fourth hydraulic motor that is driven by hydraulic pressure of hydraulic oil and drives the fuel pump. A fuel valve for injecting fuel into the combustion chamber of the diesel engine;
An exhaust valve for discharging the gas in the combustion chamber;
A hydraulic control unit that controls opening and closing of the fuel valve and the exhaust valve by hydraulic pressure of hydraulic oil;
The power plant according to any one of claims 1 to 8 , comprising:

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