WO2019159816A1 - Fuel injection device - Google Patents

Fuel injection device Download PDF

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Publication number
WO2019159816A1
WO2019159816A1 PCT/JP2019/004476 JP2019004476W WO2019159816A1 WO 2019159816 A1 WO2019159816 A1 WO 2019159816A1 JP 2019004476 W JP2019004476 W JP 2019004476W WO 2019159816 A1 WO2019159816 A1 WO 2019159816A1
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WO
WIPO (PCT)
Prior art keywords
water injection
fuel
water
injection
injection system
Prior art date
Application number
PCT/JP2019/004476
Other languages
French (fr)
Japanese (ja)
Inventor
力 松田
昭仁 青田
晃洋 三柳
泰 柿元
Original Assignee
株式会社ジャパンエンジンコーポレーション
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社ジャパンエンジンコーポレーション filed Critical 株式会社ジャパンエンジンコーポレーション
Priority to KR1020207023023A priority Critical patent/KR102375343B1/en
Priority to CN201980012802.5A priority patent/CN111699309B/en
Publication of WO2019159816A1 publication Critical patent/WO2019159816A1/en

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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02BINTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B47/00Methods of operating engines involving adding non-fuel substances or anti-knock agents to combustion air, fuel, or fuel-air mixtures of engines
    • F02B47/02Methods of operating engines involving adding non-fuel substances or anti-knock agents to combustion air, fuel, or fuel-air mixtures of engines the substances being water or steam
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D19/00Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • F02D19/12Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with non-fuel substances or with anti-knock agents, e.g. with anti-knock fuel
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M25/00Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
    • F02M25/022Adding fuel and water emulsion, water or steam
    • F02M25/025Adding water
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M43/00Fuel-injection apparatus operating simultaneously on two or more fuels, or on a liquid fuel and another liquid, e.g. the other liquid being an anti-knock additive
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M43/00Fuel-injection apparatus operating simultaneously on two or more fuels, or on a liquid fuel and another liquid, e.g. the other liquid being an anti-knock additive
    • F02M43/04Injectors peculiar thereto

Definitions

  • the present invention relates to a fuel injection device for a marine diesel engine mounted on a marine vessel.
  • a plurality of fuel layers and water injections are injected into the flow path by, for example, injecting water into the flow path of the fuel that is pumped from the fuel injection pump to the fuel injection valve.
  • Fuel and water are formed in a multilayer liquid column shape so that the layers (injected water layers) are arranged alternately.
  • the multilayer liquid columnar fuel and water are supplied from one fuel injection valve to the combustion chamber in the cylinder in the order in which the plurality of fuel layers and the water injection layer are arranged (for example, fuel-water-fuel-water-fuel, etc.). It is jetted in layers.
  • the amount of fuel in the fuel layer sandwiched between the water injection layers in the fuel flow path (hereinafter referred to as the fuel amount between the water injection layers) is: This is an extremely important factor from the viewpoint of ensuring stable performance of marine diesel engines. That is, when the ratio of the amount of fuel between the water injection layers to the amount of fuel injected into the combustion chamber (hereinafter referred to as the fuel injection amount) is excessive or excessive, the marine diesel engine may cause combustion failure, There is a risk of deteriorating fuel consumption. In order to avoid such a situation, it is preferable to be able to adjust the fuel amount between the water injection layers so that the ratio to the fuel injection amount does not become excessive or small.
  • the other water injection layer is completed. Since water injection is performed in the water injection layer, it is difficult to adjust the fuel amount between the water injection layers so that the ratio to the fuel injection amount does not become excessive or small.
  • the fuel injection amount usually increases with an increase in the load of the marine diesel engine (hereinafter referred to as engine load as appropriate) and decreases with a decrease. For this reason, in the above-described prior art, there is a possibility that the fuel amount between the water injection layers is not excessive or small with respect to the fuel injection amount at a specific engine load. In many cases, the ratio of the fuel amount between the water injection layers to the injection amount is too large or too small, and it is difficult to adjust the fuel amount between the water injection layers according to the engine load.
  • the present invention has been made in view of the above circumstances, and an object thereof is to provide a fuel injection device capable of adjusting the amount of fuel between the water injection layers in accordance with the engine load.
  • a fuel injection device includes a fuel injection valve provided in a cylinder of a marine diesel engine, and a fuel injection pump that pumps fuel to the fuel injection valve through a pipe.
  • a first water injection system for injecting water into a predetermined position of a fuel flow path from the fuel injection pump to the injection port of the fuel injection valve, and the fuel flow path more than the first water injection system.
  • a second water injection system for injecting water into a position upstream of the fuel flow direction, and a water injection period of the first water injection system and a water injection period of the second water injection system overlap at least partly,
  • a control unit that controls each water injection start timing of the first water injection system and the second water injection system according to a load of the marine diesel engine, and the fuel injection valve includes the fuel injection pump Injecting the fuel pumped by the water, the water injected by the first water injection system, and the water injected by the second water injection system into the combustion chamber in the cylinder from the injection port in a layered manner It is characterized by.
  • the control unit includes a layer of water injected by the first water injection system and a layer of water injected by the second water injection system.
  • the timing of each water injection in the first water injection system and the second water injection system is controlled so that the fuel amount in between is a constant ratio to the fuel injection amount per one time. To do.
  • the control unit is configured such that the first water injection system after the second water injection system starts water injection according to a load of the marine diesel engine. Calculates the standby time of the first water injection system until the start of water injection, and the water injection start timing of the first water injection system is more than the water injection start timing of the second water injection system for the calculated standby time. It is characterized by delaying.
  • the fuel injection device is the fuel injection apparatus according to the above invention, wherein the control unit is configured such that the second water injection system after the first water injection system starts water injection according to a load of the marine diesel engine. Calculates the standby time of the second water injection system until the start of water injection, and the water injection start timing of the second water injection system is calculated from the water injection start timing of the first water injection system by the calculated standby time. It is characterized by delaying.
  • the fuel injection device is characterized in that, in the above-mentioned invention, a ratio between a water injection amount by the first water injection system and a water injection amount by the second water injection system is constant.
  • FIG. 1 is a schematic diagram illustrating a configuration example of a marine diesel engine to which a fuel injection device according to Embodiment 1 of the present invention is applied.
  • FIG. 2 is a schematic diagram illustrating a configuration example of the fuel injection device according to the first embodiment of the present invention.
  • FIG. 3 is a diagram illustrating a configuration example of the layered liquid in the fuel flow path according to the first embodiment of the present invention.
  • FIG. 4 is a diagram for explaining control of water injection timing in the first embodiment of the present invention.
  • FIG. 5 is a diagram for explaining the adjustment of the fuel amount between the water injection layers in the first embodiment of the present invention.
  • FIG. 6 is a diagram illustrating an example of an injection amount according to the engine load of the stratified liquid according to the first embodiment of the present invention.
  • FIG. 1 is a schematic diagram illustrating a configuration example of a marine diesel engine to which a fuel injection device according to Embodiment 1 of the present invention is applied.
  • FIG. 2 is a schematic diagram
  • FIG. 7 is a schematic diagram illustrating a configuration example of the fuel injection device according to the second embodiment of the present invention.
  • FIG. 8 is a diagram for explaining control of water injection timing in the second embodiment of the present invention.
  • FIG. 9 is a diagram for explaining the adjustment of the fuel amount between the water injection layers in the second embodiment of the present invention.
  • FIG. 1 is a schematic diagram illustrating a configuration example of a marine diesel engine to which a fuel injection device according to Embodiment 1 of the present invention is applied.
  • the marine diesel engine 10 is a propulsion engine (main engine) that rotates a propeller (not shown) of a marine vessel through a propeller shaft.
  • the marine diesel engine 10 is a two-stroke diesel engine such as a uniflow scavenging crosshead diesel engine.
  • the marine diesel engine 10 includes a base plate 1 positioned below, a frame 5 provided on the base plate 1, and a cylinder jacket 11 provided on the frame 5.
  • the base plate 1, the frame 5 and the cylinder jacket 11 are integrally fastened and fixed by a plurality of tie bolts (connecting members) 21 and nuts 22 extending in the vertical direction.
  • the marine diesel engine 10 includes a cylinder 12 provided in the cylinder jacket 11, a piston 15 provided in the cylinder 12, and an output shaft (for example, a crankshaft 2) that rotates in conjunction with the reciprocating motion of the piston 15. .
  • the base plate 1 constitutes a crankcase of the marine diesel engine 10. As shown in FIG. 1, a crankshaft 2 having a crank 4 and a bearing 3 are provided in the base plate 1.
  • the crankshaft 2 is an example of an output shaft that outputs the propulsive force of the ship, and is rotatably supported by the bearing 3.
  • a lower end portion of a connecting rod 6 is rotatably connected to the crankshaft 2 via a crank 4.
  • the frame 5 is provided with a connecting rod 6, a guide plate 7, and a crosshead 8.
  • the frame 5 is arranged such that guide plates 7 provided along the piston axial direction form a pair with an interval in the width direction.
  • the connecting rod 6 is disposed between the pair of guide plates 7 in such a manner that the lower end portion thereof is connected to the crankshaft 2.
  • the cross head 8 includes a cross head pin 9 connected to the lower end portion of the piston rod 16 and a cross head bearing (not shown) connected to the upper end portion of the connecting rod 6 in the lower half of the cross head pin 9. Each is pivotably connected.
  • the cross head 8 is disposed between a pair of guide plates 7 and is supported so as to be movable along the pair of guide plates 7.
  • the cylinder jacket 11 is provided on the upper part of the frame 5 and supports the cylinder 12.
  • the cylinder 12 is a cylindrical structure (cylinder) constituted by a cylinder liner 13 and a cylinder cover 14 and has a combustion chamber 17 for burning fuel.
  • the cylinder liner 13 is, for example, a cylindrical structure and is disposed in the cylinder jacket 11.
  • a cylinder cover 14 is fixed to an upper portion of the cylinder liner 13, and thereby a space portion (combustion chamber 17 and the like) in the cylinder liner 13 is partitioned.
  • a piston 15 is provided in the space of the cylinder liner 13 so as to freely reciprocate in the piston axial direction (vertical direction in FIG. 1).
  • the upper end portion of the piston rod 16 is connected to the lower end portion of the piston 15.
  • the cylinder cover 14 is provided with an exhaust valve 18 and a valve gear 19 as shown in FIG.
  • the exhaust valve 18 is a valve that closes an exhaust port (exhaust port) of the exhaust pipe 20 that communicates with the combustion chamber 17 in the cylinder 12 so as to be openable and closable.
  • the valve gear 19 is a device that drives the exhaust valve 18 to open and close.
  • the combustion chamber 17 is a space surrounded by the exhaust valve 18 and the cylinder liner 13, the cylinder cover 14, and the piston 15 described above.
  • the marine diesel engine 10 includes a fuel injection valve 30, a fuel injection pump 41, a first water injection pump 51, and a second water injection pump 61.
  • the fuel injection valve 30 is provided in the cylinder 12 (for example, the cylinder cover 14) in such a manner that the injection port faces the combustion chamber 17.
  • the fuel injection pump 41, the first water injection pump 51, and the second water injection pump 61 are provided in the vicinity of the cylinder 12 as shown in FIG.
  • the fuel injection pump 41, the first water injection pump 51, and the second water injection pump 61 are each connected to the fuel injection valve 30 through a pipe or the like.
  • the fuel injection pump 41 appropriately pumps fuel to the fuel injection valve 30 through a distribution path such as piping.
  • Each of the first water injection pump 51 and the second water injection pump 61 appropriately injects water such as distilled water into the fuel flow path pumped by the fuel injection pump 41.
  • the water injection position by the first water injection pump 51 is downstream of the fuel injection path from the water injection position by the second water injection pump 61.
  • the fuel injection valve 30 is configured to pump the fuel pumped by the fuel injection pump 41, the water injected by the first water injection pump 51, and the water injected by the second water injection pump 61 by the pumping action of the fuel injection pump 41.
  • the fuel is alternately injected into the combustion chamber 17 (that is, injected in layers).
  • fuel and water are supplied from the fuel injection valve 30 to the combustion chamber 17 in the cylinder 12, and combustion gas such as compressed air is supplied to the scavenging port or the like (see FIG. (Not shown).
  • combustion gas such as compressed air is supplied to the scavenging port or the like (see FIG. (Not shown).
  • the supplied fuel is combusted by the combustion gas, and the supplied water lowers the combustion temperature of the fuel to reduce the NOx emission amount.
  • the piston 15 reciprocates in the direction of the piston axis in the cylinder 12 by the energy generated by the combustion of fuel in the combustion chamber 17.
  • the exhaust valve 18 is operated by the valve gear 19 and the cylinder 12 is opened, the exhaust gas generated by the combustion of the fuel is pushed out to the exhaust pipe 20.
  • combustion gas is newly introduced into the cylinder 12 from the scavenging port.
  • FIG. 2 is a schematic diagram illustrating a configuration example of the fuel injection device according to the first embodiment of the present invention.
  • the fuel injection device 100 includes a plurality (three in the first embodiment) of fuel injection valves 30, a fuel pumping system 40, a downstream water injection system 50, and an upstream water injection system 60. Is provided.
  • the fuel injection device 100 includes a water supply pump 71, a water supply pipe 72, check valves 73 a and 73 b, a pressure accumulating unit 81, a high pressure pump 82, a detecting unit 91, and a control unit 92.
  • solid arrows indicate the flow of fluid such as fuel and water
  • broken arrows indicate electric signal lines.
  • the plurality of fuel injection valves 30 are injection valves for injecting fuel and water in layers into the combustion chamber 17 (see FIG. 1) in the cylinder 12 of the marine diesel engine 10.
  • the plurality of fuel injection valves 30 are respectively provided in a plurality (only one is shown in FIG. 1) of the marine diesel engine 10. Below, the structure of the fuel injection valve 30 etc. are demonstrated by exemplifying one of these several fuel injection valves 30. FIG. The plurality of fuel injection valves 30 are similarly configured.
  • the fuel injection valve 30 is connected to a fuel injection pump 41 of the fuel pumping system 40 through a pipe or the like so as to be able to communicate therewith.
  • the fuel injection valve 30 is connected to the downstream side water injection system 50 and the upstream side water injection system 60 through a pipe or the like so as to communicate with each other.
  • the fuel injection valve 30 burns the fuel pumped by the fuel injection pump 41, the water injected by the downstream water injection system 50, and the water injected by the upstream water injection system 60 from the injection port 31 into the cylinder 12. Injected into the chamber 17 in layers.
  • the fuel injection valve 30 includes an injection port 31, internal flow paths 32 and 33 that communicate with the injection port 31, and check valves 34 a and 34 b.
  • One internal distribution path 32 is a distribution path for distributing fuel and water to be injected.
  • the internal flow path 32 has one end connected to the injection port 31 of the fuel injection valve 30 and the other end connected to a fuel injection pipe 42 (for example, its branch pipe 42a).
  • a fuel injection pipe 42 for example, its branch pipe 42a.
  • an upstream side water injection system 60 is connected to a position upstream of the internal flow path 32 (in the first embodiment, a second water injection position P2 upstream from the first water injection position P1) via a check valve 34a.
  • a pipe (for example, the branch pipe 62a of the upstream water injection pipe 62) is connected.
  • the other internal flow path 33 is a flow path for flowing water injected into the internal flow path 32.
  • One end of the internal flow path 33 is connected to a position near the injection port 31 of the internal flow path 32 (the first water injection position P1 in the first embodiment), and the other end is a pipe of the downstream water injection system 50 ( For example, it is connected to the branch pipe 52 a) of the downstream side water injection pipe 52.
  • the check valve 34a allows water to flow from the upstream water injection system 60 toward the internal flow path 32 of the fuel injection valve 30, and prevents this backflow.
  • the check valve 34 b is provided in the middle of the internal flow path 33. The check valve 34 b allows water to flow from the downstream water injection system 50 toward the internal flow path 32 through the internal flow path 33 of the fuel injection valve 30, and prevents this reverse flow.
  • the fuel pumping system 40 is a facility for pumping fuel to the fuel injection valve 30. As shown in FIG. 2, the fuel pumping system 40 includes a fuel injection pump 41, a fuel injection pipe 42, and a control valve 45.
  • the fuel injection pump 41 is a hydraulically driven pump that pumps fuel using the pressure of hydraulic oil. Specifically, the fuel injection pump 41 receives fuel from a fuel tank (not shown) through a pipe or the like. The fuel injection pump 41 pumps the received fuel to the fuel injection valve 30 through the fuel injection pipe 42. Further, the pumping action of the fuel injection pump 41 causes the fuel injection valve 30 to perform a layered injection of fuel and water from the injection port 31 to the combustion chamber 17 in the cylinder 12.
  • the fuel injection pipe 42 is a pipe for allowing fuel to flow between the fuel injection pump 41 and the fuel injection valve 30.
  • one end of the fuel injection pipe 42 is connected to the discharge port of the fuel injection pump 41.
  • a branch portion 43 is provided in the middle of the fuel injection pipe 42.
  • the fuel injection pipe 42 is branched into a plurality of branch pipes (three branch pipes 42a, 42b, 42c in the first embodiment) from the branch part 43 toward the other end.
  • the branch pipe 42a is connected to the internal flow path 32 of one fuel injection valve 30 as shown in FIG.
  • the fuel injection pipe 42 allows the fuel injection valve 30 and the fuel injection pump 41 to communicate with each other through the branch pipe 42a.
  • the remaining branch pipes 42b and 42c are connected to the other fuel injection valves 30, respectively.
  • the control valve 45 is a valve for controlling the supply of hydraulic oil from the pressure accumulating unit 81 to the fuel injection pump 41.
  • the control valve 45 is constituted by an electric on-off valve such as an electromagnetic valve, and although not shown, as shown in FIG. 2, the fuel injection pump is opened and closed by opening / closing a logic valve driven by the control valve 45. 41 and the pressure accumulating portion 81 are provided so as to communicate with each other.
  • the control valve 45 is opened at the fuel injection timing, and supplies the hydraulic oil in the pressure accumulating unit 81 to the fuel injection pump 41.
  • the fuel injection pump 41 pumps fuel to the fuel injection valve 30 using the pressure of the supplied hydraulic oil.
  • the control valve 45 is closed during a period other than the fuel injection timing, and stops supplying hydraulic oil from the pressure accumulating unit 81 to the fuel injection pump 41.
  • the timing for opening and closing the control valve 45 is controlled by the control unit 92.
  • the downstream water injection system 50 is an example of a first water injection system that injects water into the first water injection position P1 of the fuel flow path in the first embodiment. As shown in FIG. 2, the downstream water injection system 50 includes a first water injection pump 51, a downstream water injection pipe 52, a check valve 54, and a control valve 55.
  • the first water injection pump 51 is a hydraulic drive pump that performs water injection using the pressure of hydraulic oil. Specifically, the first water injection pump 51 receives water from the water supply pump 71 through the water supply pipe 72 and the like. The first water injection pump 51 pumps the received water to the internal flow path 32 of the fuel injection valve 30 through the downstream water supply pipe 52 and the internal flow path 33 of the fuel injection valve 30. Thereby, the 1st water injection pump 51 inject
  • the downstream water injection pipe 52 is a pipe for circulating water injected by the first water injection pump 51 into the first water injection position P1 of the fuel distribution path.
  • one end of the downstream water injection pipe 52 is connected to the discharge port of the first water injection pump 51.
  • a branch portion 53 is provided in the middle of the downstream water injection pipe 52.
  • the downstream side water injection pipe 52 is branched into a plurality of branch pipes (three branch pipes 52a, 52b, 52c in the first embodiment) from the branch part 53 toward the other end part.
  • the branch pipe 52a is connected to the internal flow path 33 of one fuel injection valve 30 as shown in FIG.
  • the downstream water injection pipe 52 allows the internal flow path 33 of the fuel injection valve 30 and the first water injection pump 51 to communicate with each other via the branch pipe 52a.
  • the remaining branch pipes 52b and 52c are connected to the other fuel injection valves 30, respectively.
  • the check valve 54 is a valve for preventing the back flow of water by restricting the flow direction of the water in the downstream side water injection pipe 52 in one direction. As shown in FIG. 2, the check valve 54 is provided in a midway portion of the downstream side water injection pipe 52 (for example, a portion between the first water injection pump 51 and the branch portion 53). The check valve 54 allows water to flow from the first water injection pump 51 side toward the fuel flow path side (in the first embodiment, the internal flow paths 32 and 33 side of the fuel injection valve 30), and prevents this backflow. .
  • the control valve 55 is a valve for controlling the supply of hydraulic oil from the pressure accumulating unit 81 to the first water injection pump 51.
  • the control valve 55 is configured by an electrically operated on-off valve such as an electromagnetic valve, and is provided so that the first water injection pump 51 and the pressure accumulating portion 81 can communicate with each other as shown in FIG.
  • the control valve 55 is in an open state during a period for injecting water from the first water injection pump 51 into the fuel flow path (hereinafter referred to as a water injection period for the downstream side water injection system 50 as appropriate), and the hydraulic oil in the pressure accumulating unit 81. Is supplied to the first water injection pump 51.
  • the first water injection pump 51 uses the pressure of the supplied hydraulic oil to pump and inject water into the first water injection position P1 of the fuel flow path.
  • the control valve 55 is closed during a period other than the water injection period of the downstream side water injection system 50, and stops supplying hydraulic oil from the pressure accumulating unit 81 to the first water injection pump 51.
  • the timing for opening and closing the control valve 55 is controlled by the control unit 92.
  • the upstream water injection system 60 is an example of a second water injection system that injects water into the second water injection position P2 of the fuel flow path in the first embodiment. As shown in FIG. 2, the upstream water injection system 60 includes a second water injection pump 61, an upstream water injection pipe 62, a check valve 64, and a control valve 65.
  • the second water injection pump 61 is a hydraulically driven pump that performs water injection using the pressure of hydraulic oil. Specifically, the second water injection pump 61 receives water from the water supply pump 71 through the water supply pipe 72 and the like. The second water injection pump 61 pumps the received water to the internal flow path 32 of the fuel injection valve 30 through the upstream side water injection pipe 62. As a result, the second water injection pump 61 injects water into the second water injection position P2 of the fuel flow path in the first embodiment.
  • the upstream water injection pipe 62 is a pipe for circulating water injected by the second water injection pump 61 into the second water injection position P2 of the fuel distribution path.
  • one end of the upstream water injection pipe 62 is connected to the discharge port of the second water injection pump 61.
  • a branch portion 63 is provided in the middle of the upstream side water injection pipe 62.
  • the upstream water injection pipe 62 is branched into a plurality of branch pipes (three branch pipes 62a, 62b, 62c in the first embodiment) from the branch part 63 toward the other end part.
  • the branch pipe 62a is connected to the internal flow path 32 of one fuel injection valve 30 via the check valve 34a as shown in FIG. ing.
  • the upstream water injection pipe 62 communicates the internal flow path 32 of the fuel injection valve 30 and the second water injection pump 61 via the branch pipe 62a.
  • the remaining branch pipes 62b and 62c are connected to the other fuel injection valves 30, respectively.
  • the check valve 64 is a valve for preventing the reverse flow of water by restricting the flow direction of the water in the upstream side water injection pipe 62 in one direction. As shown in FIG. 2, the check valve 64 is provided in a midway part of the upstream water injection pipe 62 (for example, a part between the second water injection pump 61 and the branch part 63). The check valve 64 allows water to flow from the second water injection pump 61 side toward the fuel flow path side (in the first embodiment, the internal flow path 32 side of the fuel injection valve 30), and prevents this backflow.
  • the control valve 65 is a valve for controlling the supply of hydraulic oil from the pressure accumulating unit 81 to the second water injection pump 61.
  • the control valve 65 is configured by an electrically operated on-off valve such as an electromagnetic valve, and is provided so that the second water injection pump 61 and the pressure accumulating portion 81 can communicate with each other as shown in FIG.
  • the control valve 65 is in an open state during a period of injecting water from the second water injection pump 61 into the fuel flow path (hereinafter referred to as a water injection period of the upstream water injection system 60 as appropriate), and the hydraulic oil in the pressure accumulating unit 81 is opened. Is supplied to the second water injection pump 61.
  • the second water injection pump 61 uses the pressure of the supplied hydraulic oil to pump and inject water into the second water injection position P2 of the fuel flow path.
  • the control valve 65 is closed during a period other than the water injection period of the upstream water injection system 60, and stops the supply of hydraulic oil from the pressure accumulating unit 81 to the second water injection pump 61.
  • the timing for opening and closing the control valve 65 is controlled by the control unit 92.
  • the fuel flow path in the first embodiment is a fuel flow path from the fuel injection pump 41 to the injection port 31 of the fuel injection valve 30.
  • this fuel flow path is formed by the fuel injection pipe 42 including the branch pipes 42 a to 42 c and the internal flow path 32 of the fuel injection valve 30.
  • the first water injection position P1 is a predetermined position in this fuel flow path.
  • the first water injection position P1 is a position in the vicinity of the injection port 31 in the internal flow path 32 of the fuel injection valve 30, that is, the most fuel flow direction in the fuel flow path. This is the position immediately upstream of a predetermined amount of fuel (a fuel in a first fuel layer F1 shown in FIG. 3 described later) existing downstream.
  • the second water injection position P2 is a position on the upstream side in the fuel flow direction of the downstream water injection system 50 in the fuel flow path.
  • the second water injection position P2 is, for example, as shown in FIG. 2, the fuel injection valve 41 side position in the internal flow path 32 of the fuel injection valve 30, that is, the fuel from the first water injection position P1. It is a position of the distribution direction upstream side.
  • the fuel flow direction is a direction from the fuel injection pump 41 toward the injection port 31 of the fuel injection valve 30 through the fuel injection pipe 42 and the like.
  • the water supply pump 71 is a pump for supplying the water injected into the above-described fuel flow path to the first water injection pump 51 and the second water injection pump 61. As shown in FIG. 2, the water supply pump 71 is connected to the first water injection pump 51 and the second water injection pump 61 through a water supply pipe 72 and the like so as to communicate with each other. One end of the water supply pipe 72 is connected to the water supply pump 71. Moreover, the water supply pipe 72 is branched into the branch pipes 72a and 72b in the middle. One branch pipe 72a of the water supply pipe 72 is connected to the first water injection pump 51 via a check valve 73a. The other branch pipe 72b of the water supply pipe 72 is connected to the second water injection pump 61 via a check valve 73b.
  • the water supply pump 71 supplies water stored in a water supply tank (not shown) to the first water injection pump 51 through the branch pipe 72a of the water supply pipe 72 and the like through the branch pipe 72b of the water supply pipe 72. 2 Supply to water injection pump 61.
  • the check valve 73a allows water to flow from the water supply pump 71 side to the first water injection pump 51 side, and prevents this backflow.
  • the check valve 73b allows water to flow from the water supply pump 71 side to the second water injection pump 61 side, and prevents this backflow.
  • the pressure accumulating unit 81 accumulates the pressure of hydraulic oil that operates the fuel pumping system 40, the downstream water injection system 50, and the upstream water injection system 60.
  • the pressure accumulating portion 81 is a hollow structure that internally forms a pressure accumulating chamber capable of storing hydraulic oil, and is connected to a high pressure pump 82 via a pipe or the like as shown in FIG.
  • the pressure accumulating unit 81 stores the hydraulic oil discharged (pressure-fed) from the high-pressure pump 82 in an internal pressure accumulating chamber, thereby accumulating the pressure of the hydraulic oil.
  • the pressure of the hydraulic oil accumulated in the pressure accumulating portion 81 is adjusted by the discharge amount of the hydraulic oil from the high pressure pump 82 to the pressure accumulating portion 81.
  • the pressure of the hydraulic oil accumulated in the pressure accumulating portion 81 is the operation of the fuel injection pump 41 of the fuel pumping system 40, the operation of the first water injection pump 51 of the downstream water injection system 50, and the second water injection of the upstream water injection system 60. It is shared with the operation of the pump 61.
  • Detecting unit 91 detects the crank angle of marine diesel engine 10 (see FIG. 1).
  • the detection unit 91 detects the rotation angle (that is, the crank angle) of the crank 4 that rotates in association with the reciprocating motion of the piston 15 in the cylinder 12 in one cycle.
  • the detection unit 91 detects the rotation angle of the crank 4 from the reference state as the crank angle.
  • the reference state of the crank 4 includes, for example, the state of the crank 4 when the piston 15 is located at the bottom dead center or the top dead center.
  • the detection unit 91 detects a crank angle as time passes, and transmits an electric signal indicating the detected crank angle to the control unit 92 each time.
  • the controller 92 controls the fuel and water layer injection timing, the water injection timing of the downstream water injection system 50, and the water injection timing of the upstream water injection system 60.
  • the layered injection timing of fuel and water means the timing at which fuel and water are injected in layers from the fuel injection valve 30 into the combustion chamber 17 (see FIG. 1) in the cylinder 12 of the marine diesel engine 10.
  • the water injection timing of the downstream side water injection system 50 is the water injection start timing at which the first water injection pump 51 starts water injection at the first water injection position P1 of the fuel flow path and the water injection end timing at which water injection to the first water injection position P1 is ended. Means.
  • the water injection timing of the upstream water injection system 60 is the water injection start timing at which water injection is started to the second water injection position P2 of the fuel flow path by the second water injection pump 61, and the water injection end timing at which water injection to the second water injection position P2 is ended. Means.
  • control unit 92 includes a CPU, a memory, a sequencer, and the like for executing various programs.
  • the control unit 92 receives the electrical signal from the detection unit 91, and opens and closes the control valve 45 of the fuel pumping system 40 so that the crank angle indicated by the received electrical signal becomes an opening state at a predetermined rotation angle. Control the drive.
  • the control unit 92 controls the operation timing of the fuel injection pump 41 through control of the opening / closing drive of the control valve 45. Thereby, the control part 92 controls the layered injection timing of the fuel and water from the fuel injection valve 30 to the combustion chamber 17.
  • a required amount of fuel corresponding to the engine load out of the fuel pumped to the fuel flow path by the fuel injection pump 41 and the first water injection pump 51 are injected into the first water injection position P1 of the fuel flow path.
  • the water injected into the second water injection position P2 of the fuel flow path by the second water injection pump 61 is injected in layers from the fuel injection valve 30 to the combustion chamber 17 by the pumping action of the fuel injection pump 41. Thereafter, this fuel flow path (the fuel flow path constituted by the fuel injection pipe 42 and the internal flow path 32 of the fuel injection valve 30 in the first embodiment) is filled with the remaining fuel without being injected. .
  • control part 92 injects water into the 1st water injection position P1 and the 2nd water injection position P2 of the fuel distribution path which are in the state filled with fuel, respectively in periods other than the layered injection timing of the fuel and water mentioned above.
  • the water injection timing of the downstream side water injection system 50 and the water injection timing of the upstream side water injection system 60 are controlled.
  • the control unit 92 sets the downstream side water injection system according to the engine load of the marine diesel engine 10 so that at least a part of the water injection period of the downstream side water injection system 50 and the water injection period of the upstream side water injection system 60 overlap.
  • the water injection start timing by 50 first water injection pumps 51 and the water injection start timing by second water injection pump 61 of upstream water injection system 60 are controlled.
  • FIG. 3 is a diagram illustrating a configuration example of the layered liquid in the fuel flow path according to the first embodiment of the present invention.
  • the injection port side is the injection port 31 side of the fuel injection valve 30, that is, the downstream side in the fuel flow direction in the fuel flow path.
  • the fuel injection pump side is the fuel injection pump 41 side of the fuel pumping system 40, that is, the upstream side in the fuel distribution direction in the fuel distribution path. As shown in FIG.
  • the stratified liquid 200 includes a plurality of liquid layers arranged from the injection port side toward the fuel injection pump side, for example, a first liquid layer L1, a second liquid layer L2, a third liquid layer L3, The fourth liquid layer L4 and the fifth liquid layer L5 are configured.
  • the first liquid layer L1 is the most downstream liquid layer in the layered liquid 200.
  • the stratified liquid 200 includes a first fuel layer F1 as the first liquid layer L1.
  • the first fuel layer F1 is the first fuel layer of the plurality (three in FIG. 3) of fuel layers included in the stratified liquid 200, counted from the injection port side, and exists at the most downstream in the fuel flow direction. A predetermined amount of fuel.
  • the second liquid layer L2 is a liquid layer immediately upstream of the first liquid layer L1 in the layered liquid 200.
  • the layered liquid 200 includes a first water injection layer W1 as the second liquid layer L2.
  • the first water injection layer W1 is a first water injection layer counted from the injection port side among a plurality (two in FIG. 3) of water injection layers included in the layered liquid 200.
  • the first water injection layer W1 is formed by injecting a necessary amount of water into the first water injection position P1 of the fuel circulation path by the first water injection pump 51.
  • the third liquid layer L3 is a liquid layer immediately upstream of the second liquid layer L2 in the layered liquid 200.
  • the stratified liquid 200 includes a second fuel layer F2 as the third liquid layer L3.
  • the second fuel layer F2 is a second fuel layer among the plurality of fuel layers included in the layered liquid 200, counted from the injection port side.
  • the second fuel layer F2 is made of fuel sandwiched between a layer of water injected into the first water injection position P1 and a layer of water injected into the second water injection position P2 of the fuel flow path.
  • the fourth liquid layer L4 is a liquid layer immediately upstream of the third liquid layer L3 in the layered liquid 200.
  • the layered liquid 200 includes a second water injection layer W2 as the fourth liquid layer L4.
  • the second water injection layer W ⁇ b> 2 is a second water injection layer counted from the injection port side among the plurality of water injection layers included in the layered liquid 200.
  • the second water injection layer W2 is formed by injecting a necessary amount of water into the second water injection position P2 of the fuel flow path by the second water injection pump 61.
  • the fifth liquid layer L5 is the most upstream liquid layer in the layered liquid 200.
  • the layered liquid 200 includes a third fuel layer F3 as the fifth liquid layer L5.
  • the third fuel layer F3 is a third fuel layer counted from the injection port side among the plurality of fuel layers included in the layered liquid 200.
  • the third fuel layer F3 is made of fuel that exists immediately upstream of the second water injection layer W2.
  • Such a layered liquid 200 of fuel and water is injected from the injection port 31 of the fuel injection valve 30 into the combustion chamber 17 in the cylinder 12 for each reciprocation of the piston 15 in one cycle.
  • the fuel injection amount Qfa of the layered liquid 200 increases as the engine load increases, and decreases as the engine load decreases.
  • the water injection amount Qwa of the layered liquid 200 is adjusted to a required amount according to the engine load so as to achieve a reduction in NOx and an improvement in fuel consumption.
  • the ratio of the water injection amount Qw1 of the first water injection layer W1 and the water injection amount Qw2 of the second water injection layer W2, that is, the ratio of the water injection amount by the downstream side water injection system 50 and the water injection amount by the upstream side water injection system 60 is Preferably it is constant.
  • FIG. 4 is a diagram for explaining control of water injection timing in the first embodiment of the present invention.
  • the valve control signal S1 is a control signal for instructing the control valve 55 of the first water injection pump 51 that injects water into the first water injection position P1 (see FIG. 2) of the fuel flow path to open and close. It is.
  • the valve control signal S2 is a control signal for instructing the control valve 65 of the second water injection pump 61 that injects water into the second water injection position P2 (see FIG. 2) of the fuel flow path to open and close.
  • FIG. 5 is a diagram for explaining the adjustment of the fuel amount between the water injection layers in the first embodiment of the present invention.
  • a fuel column 201 is a columnar fuel remaining in the fuel flow path in the first embodiment.
  • the control unit 92 transmits, for example, valve control signals S1 and S2 shown in FIG. 4 to the control valves 55 and 65, respectively, to control the timing of opening and closing of the control valves 55 and 65.
  • the control part 92 water injection timing (1st layer water injection timing) of the downstream water injection system 50 so that at least one part of the water injection period of the downstream water injection system 50 and the water injection period of the upstream water injection system 60 may overlap.
  • the water injection timing (second layer water injection timing) of the upstream water injection system 60 are controlled according to the engine load.
  • control unit 92 determines that the amount of fuel between the layer of water injected by the downstream side water injection system 50 and the layer of water injected by the upstream side water injection system 60 corresponds to the engine load.
  • Each water injection start timing of the downstream side water injection system 50 and the upstream side water injection system 60 is controlled so as to be a constant ratio with respect to the injection amount Qfa.
  • the control unit 92 calculates the water injection standby time ⁇ T according to the engine load.
  • the waiting time ⁇ T is the time when the operation of the water injection piston of the water injection system that starts water injection from the time of starting the operation of the water injection piston of the water injection system of the downstream side water injection system 50 and the upstream side water injection system 60 that started water injection first. It is time until.
  • the waiting time ⁇ T is, for example, the engine speed at the time of engine load (engine speed per unit time) required for the marine diesel engine 10 according to the navigation status of the ship and the fuel injection amount (per fuel time).
  • the following equation (1) is expressed by a function f (x, y, z) including the injection amount) and the water injection amount (the amount of water injected into the fuel for one injection) as independent variables x, y, z.
  • the control unit 92 calculates the standby time ⁇ T so that the standby time ⁇ T increases as the engine load increases and the standby time ⁇ T decreases as the engine load decreases.
  • Standby time ⁇ T f (x, y, z) (1)
  • the engine speed, the fuel injection amount, and the water injection amount can be derived based on the results of simulation, experiment, etc. of the marine diesel engine 10. This equation (1) is preset in the control unit 92.
  • the control unit 92 calculates, for example, the standby time ⁇ T1 of the downstream water injection system 50 as the standby time ⁇ T.
  • the waiting time ⁇ T1 of the downstream side water injection system 50 is a time from when the upstream side water injection system 60 starts water injection to when the downstream side water injection system 50 starts water injection, that is, when the second water injection pump 61 starts operating. Until the first water injection pump 51 starts operating.
  • the control unit 92 delays the water injection start timing of the downstream side water injection system 50 from the water injection start timing of the upstream side water injection system 60 by the calculated waiting time ⁇ T1.
  • the control unit 92 acquires the crank angle indicated by the electrical signal received from the detection unit 91 as the crank angle detected by the detection unit 91 (hereinafter referred to as a crank angle detection value as appropriate). As shown in FIG. 4, the control unit 92 instructs the control valve 65 of the upstream water injection system 60 to open at timing T1 when the detected crank angle value becomes the crank angle R1. Thereby, the control part 92 starts the operation
  • water injection to the fuel column 201 is not started at the timing T0 within the period from the completion of the previous fuel injection to the water injection start timing (timing T1).
  • the fuel amount of the fuel column 201 at this time corresponds to the fuel injection amount Qfa described above.
  • the control unit 92 starts the water injection by the downstream side water injection system 50 at a timing delayed from the water injection start timing of the upstream side water injection system 60 by the waiting time ⁇ T1 calculated as described above. Specifically, the control unit 92 converts the waiting time ⁇ T1 of the downstream water injection system 50 into a crank angle change amount ⁇ R based on the engine speed corresponding to the engine load and the elapsed time of the engine rotation. The controller 92 calculates the crank angle R2 by adding the obtained change amount ⁇ R of the crank angle and the crank angle R1 at the water injection start timing (timing T1) of the upstream water injection system 60. As shown in FIG.
  • the control unit 92 instructs the control valve 55 of the downstream water injection system 50 to open at timing T ⁇ b> 2 when the detected crank angle value becomes the crank angle R ⁇ b> 2.
  • the control part 92 starts operation
  • FIG. Based on this control, the first water injection pump 51 starts water injection to the first water injection position P1 of the fuel flow path. That is, the timing T2 of the crank angle R2 is the water injection start timing of the downstream side water injection system 50.
  • the second water injection pump 61 continuously performs water injection to the second water injection position P2 of the fuel flow path. At this timing T2, as shown in FIG. 5, water 202 is continuously injected into the second water injection position P2 in the fuel column 201 in the fuel flow path, and the water is supplied to the first water injection position P1. 203 injection has started.
  • the second water injection pump 61 continues to inject water into the second water injection position P2 of the fuel flow path until the control valve 65 is driven to close.
  • the first water injection pump 51 continuously performs water injection to the first water injection position P1 of the fuel flow path until the control valve 55 is driven to close.
  • the injection of the water 202 at the second water injection position P2 proceeds, and at the first water injection position P1.
  • Injection of water 203 proceeds.
  • the fuel between the first water injection position P1 and the second water injection position P2 is pushed back upstream of the water 202 at the second water injection position P2 in the flow direction. .
  • the fuel amount between the 1st water injection position P1 and the 2nd water injection position P2 is adjusted so that it may reduce.
  • the water 202 at the second water injection position P2 is injected until it spreads over the entire width direction of the fuel column 201 (width direction of the fuel flow path).
  • the water 202 at the second water injection position P2 moves the fuel column 201 downstream of the second water injection position P2 and the downstream fuel 201a and the second water injection position P2. It is divided into the most upstream fuel 201b located on the upstream side.
  • the fuel between the first water injection position P1 and the second water injection position P2 circulates over the water 202 at the second water injection position P2 even if the injection of the water 203 at the first water injection position P1 proceeds. No longer being pushed back in the direction upstream. Thereby, the adjustment of the fuel amount between the first water injection position P1 and the second water injection position P2 is completed, and the fuel amount of the downstream fuel 201a is determined.
  • the control unit 92 instructs the control valve 65 of the upstream water injection system 60 to be closed at a timing T4 when the crank angle detection value becomes the crank angle R4. Accordingly, the control unit 92 stops the operation of the second water injection pump 61 of the upstream side water injection system 60 while continuing the operation of the first water injection pump 51 of the downstream side water injection system 50. Based on this control, the second water injection pump 61 ends water injection to the second water injection position P2 of the fuel flow path. That is, the timing T4 of the crank angle R4 is the water injection end timing of the upstream water injection system 60. On the other hand, the first water injection pump 51 continuously performs water injection to the first water injection position P1 of the fuel flow path.
  • the water 202 at the second water injection position P2 spreads over the entire width direction of the fuel column 201.
  • the water 203 at the first water injection position P1 is continuously injected.
  • the injection of the water 203 at the first water injection position P1 is performed while pushing the water 202 at the second water injection position P2 together with the downstream fuel 201a to the upstream side in the flow direction.
  • the water 203 at the first water injection position P ⁇ b> 1 is in a state of being injected until it spreads over the entire width direction of the fuel column 201.
  • the water 203 is obtained by changing the downstream fuel 201a of the fuel column 201 between the most downstream fuel 201c located downstream of the first water injection position P1, the water 202 at the second water injection position P2, and the first water injection position P1. It is divided into a water injection interlayer fuel 201 d sandwiched between water 203.
  • the timing at which the water 203 at the first water injection position P1 is injected until it spreads over the entire width direction of the fuel column 201 may be the same as the timing T4 at which the required amount of water 202 at the second water injection position P2 is injected. It may be the previous timing or the later timing.
  • the control unit 92 instructs the control valve 55 of the downstream water injection system 50 to be closed at timing T5 when the crank angle detection value becomes the crank angle R5.
  • the control part 92 stops operation
  • the first water injection pump 51 ends water injection to the first water injection position P1 of the fuel flow path. That is, the timing T5 of the crank angle R5 is the water injection end timing of the downstream water injection system 50.
  • the water 203 at the first water injection position P1 spreads over the entire width direction of the fuel column 201. It is further injected from the state.
  • the injection of the water 202 at the second water injection position P2 has already ended at the timing T4 described above.
  • the injection of the water 203 at the first water injection position P1 is performed in the same manner as the period from the timing T3 to the timing T4 described above, and is continued until the injection amount of the water 203 becomes a necessary amount.
  • each water injection of the 1st water injection position P1 and the 2nd water injection position P2 is completed.
  • a stratified liquid 200 composed of the first fuel layer F1, the first water injection layer W1, the second fuel layer F2, the second water injection layer W2, and the third fuel layer F3 is formed in the fuel flow path.
  • the water injection period of the upstream water injection system 60 is a period from the timing T1 of the crank angle R1 to the timing T4 of the crank angle R4. That is, the water injection period of the upstream water injection system 60 is a period corresponding to the time obtained by adding the waiting time ⁇ T1, the time ⁇ T2, and the time ⁇ T3 shown in FIG.
  • This water injection period is determined by the time it takes to inject the required amount of water 202 into the second water injection position P2 shown in FIG. That is, the crank angle R4 corresponding to the water injection end timing (timing T4) of the upstream water injection system 60 is based on the crank angle R1 corresponding to the water injection start timing and the time required for injecting the required amount of water 202. Derived.
  • the water injection period of the downstream water injection system 50 is a period from the timing T2 of the crank angle R2 to the timing T5 of the crank angle R5. This water injection period is determined by the time taken to inject a required amount of water 203 into the first water injection position P1 shown in FIG. That is, the crank angle R5 corresponding to the water injection end timing (timing T5) of the downstream side water injection system 50 is based on the crank angle R2 corresponding to the water injection start timing and the time required to inject the required amount of water 203. Derived.
  • the overlapping period of the water injection period of the upstream water injection system 60 and the water injection period of the downstream water injection system 50 corresponds to the time ⁇ T4 from the crank angle R2 to the crank angle R4 as shown in FIG. .
  • This time ⁇ T4 is adjusted (decrease adjustment) so that the amount of fuel between the water injection layers is reduced by the water injection of the downstream water injection system 50, and after the adjustment of the fuel amount between the water injection layers is completed, the upstream water injection system 60 This is a time obtained by adding the time ⁇ T3 until the water injection is completed.
  • the water injection start timing of the downstream water injection system 50 is on standby from the water injection start timing of the upstream water injection system 60 so that the time ⁇ T2 decreases as the engine load increases and the time ⁇ T2 increases as the engine load decreases.
  • the timing is controlled to be delayed by time ⁇ T1. That is, the waiting time ⁇ T1 increases with an increase in engine load, and decreases with a decrease in engine load.
  • the water injection start timing of the downstream side water injection system 50 is controlled to the same timing as the water injection start timing of the upstream side water injection system 60.
  • FIG. 6 is a diagram illustrating an example of an injection amount corresponding to the engine load of the stratified liquid according to the first embodiment of the present invention.
  • the injection amount shown in FIG. 6 is an injection amount per time of the stratified liquid 200 (see FIG. 3) injected from one fuel injection valve 30 into the combustion chamber 17 in the cylinder 12.
  • the injection amount of the layered liquid 200 is set by controlling the water injection start timings of the downstream water injection system 50 and the upstream water injection system 60 described above. For example, as shown in FIG. 6, the injection amount of the layered liquid 200 increases as the engine load increases, and decreases as the engine load decreases.
  • the fuel amount of the second fuel layer F2 sandwiched between the first water injection layer W1 and the second water injection layer W2 (that is, the fuel amount between the water injection layers) depends on the engine load. Adjust to the appropriate amount.
  • in the engine load range (55% or more and 100% or less in FIG.
  • the amount of fuel between the water injection layers is equal to the engine load.
  • the fuel injection amount Qfa that increases or decreases accordingly is adjusted (optimized) to be a constant ratio. Furthermore, in the layered liquid 200, the ratio of the water injection amount Qw1 of the first water injection layer W1 and the water injection amount Qw2 of the second water injection layer W2 is constant.
  • the fuel injection valve 30 that injects fuel and water into the combustion chamber 17 in the cylinder 12 of the marine diesel engine 10 in a layered manner, and through the piping.
  • a fuel injection pump 41 that pumps fuel to the fuel injection valve 30;
  • a downstream water injection system 50 that injects water into the first water injection position P1 of the fuel flow path from the fuel injection pump 41 to the injection port 31 of the fuel injection valve 30;
  • An upstream water injection system 60 for injecting water into the second water injection position P2 upstream of the downstream water injection system 50 in the fuel distribution direction in the fuel distribution path is provided, and the water injection period and upstream of the downstream water injection system 50 are provided.
  • the standby time ⁇ T1 of the downstream water injection system 50 from when the upstream water injection system 60 starts water injection to when the downstream water injection system 50 starts water injection is calculated according to the engine load, and the calculated standby time ⁇ T1 Minutes, the water injection start timing of the downstream water injection system 50 is delayed from the water injection start timing of the upstream water injection system 60.
  • the water injection layer formed by the downstream side water injection system 50 and the water injection layer formed by the upstream side water injection system 60 are overlapped with each other within the overlapping period of the water injection period of the downstream side water injection system 50 and the water injection period of the upstream side water injection system 60.
  • the amount of fuel (the amount of fuel between the water injection layers) can be adjusted so that the ratio of the amount of fuel between the water injection layers relative to the fuel injection amount Qfa according to the engine load does not become excessive or small. For this reason, when fuel and water are injected in layers from the fuel injection valve 30, the amount of fuel between the water injection layers can be appropriately adjusted according to the engine load. As a result, it is possible to suppress the occurrence of an undesirable combustion state such as poor combustion of the marine diesel engine 10 that may occur when fuel and water are injected in layers to reduce NOx in the exhaust gas.
  • the downstream water injection system 50 and the upstream are arranged so that the fuel amount between the water injection layers described above is a constant ratio with respect to the fuel injection amount Qfa corresponding to the engine load.
  • Each water injection start timing of the side water injection system 60 is controlled according to the engine load. For this reason, when fuel and water are injected in layers from the fuel injection valve 30, the fuel amount between the water injection layers can be adjusted to the optimum fuel amount for each engine load. As a result, NOx in the exhaust gas can be reduced most effectively.
  • the ratio between the water injection amount Qw1 by the downstream water injection system 50 and the water injection amount Qw2 by the upstream water injection system 60 is made constant. For this reason, when fuel and water are injected in layers from the fuel injection valve 30, the amount of water in the water injection layer injected following the fuel layer can be optimized for each engine load. As a result, misfire caused by water injection after fuel combustion can be prevented to ensure stable operation of the marine diesel engine 10, and NOx in the exhaust gas can be most effectively reduced.
  • the downstream side water injection system 50 and the upstream side are set so as to delay the water injection start timing of the downstream side water injection system 50 from the water injection start timing of the upstream side water injection system 60 by the standby time calculated according to the engine load.
  • the water injection start timing of the upstream water injection system 60 is set to the water injection start time of the upstream water injection system 50 for the standby time calculated according to the engine load.
  • Each water injection start timing of the downstream side water injection system 50 and the upstream side water injection system 60 is controlled so as to be delayed from the start timing.
  • FIG. 7 is a schematic diagram showing a configuration example of a fuel injection device according to Embodiment 2 of the present invention.
  • the fuel injection device 110 includes a control unit 112 instead of the control unit 92 of the fuel injection device 100 according to Embodiment 1 described above.
  • Other configurations are the same as those of the first embodiment, and the same components are denoted by the same reference numerals.
  • the marine diesel engine to which the fuel injection device 110 according to the second embodiment is applied has the same configuration as the marine diesel engine 10 in the first embodiment described above, except for the configuration including the control unit 112 described above. Is done.
  • the control unit 112 includes a CPU, a memory, a sequencer, and the like for executing various programs.
  • the control unit 112 injects water into each of the first water injection position P1 and the second water injection position P2 of the fuel flow path in a state other than the above-described fuel and water layered injection timing.
  • the water injection timing of the downstream side water injection system 50 and the water injection timing of the upstream side water injection system 60 are controlled according to the engine load.
  • the control unit 112 sets the upstream side of the standby time calculated according to the engine load so that at least a part of the water injection period of the downstream water injection system 50 and the water injection period of the upstream water injection system 60 overlap each other.
  • the control part 112 controls the layered injection timing of the fuel and water from the fuel injection valve 30 to the combustion chamber 17 similarly to the control part 92 in Embodiment 1 mentioned above.
  • FIG. 8 is a diagram for explaining control of water injection timing in the second embodiment of the present invention.
  • FIG. 9 is a diagram for explaining the adjustment of the fuel amount between the water injection layers in the second embodiment of the present invention.
  • control unit 112 transmits, for example, valve control signals S1 and S2 shown in FIG. 8 to the control valves 55 and 65, respectively, to control the timing of opening and closing of the control valves 55 and 65.
  • control part 112 water injection timing (1st layer water injection timing) of the downstream water injection system 50 so that at least one part of the water injection period of the downstream water injection system 50 and the water injection period of the upstream water injection system 60 may overlap.
  • water injection timing (second layer water injection timing) of the upstream water injection system 60 are controlled according to the engine load.
  • control unit 112 determines the amount of fuel between the water layer injected by the downstream water injection system 50 and the water layer injected by the upstream water injection system 60 according to the engine load.
  • Each water injection start timing of the downstream side water injection system 50 and the upstream side water injection system 60 is controlled so as to be a constant ratio with respect to the injection amount Qfa.
  • the control unit 112 calculates the standby time ⁇ T11 of the upstream water injection system 60, for example, as the standby time ⁇ T based on the formula (1) in which the above-described formula (1) is set in advance.
  • the standby time ⁇ T11 of the upstream side water injection system 60 is the time from when the downstream side water injection system 50 starts water injection to when the upstream side water injection system 60 starts water injection, that is, when the first water injection pump 51 starts operating. Until the second water injection pump 61 starts operating.
  • the control unit 112 delays the water injection start timing of the upstream water injection system 60 from the water injection start timing of the downstream water injection system 50 by the calculated waiting time ⁇ T11 minutes.
  • the control unit 112 acquires the crank angle detection value by the detection unit 91, and as shown in FIG. 8, controls the downstream side water injection system 50 at timing T11 when the crank angle detection value becomes the crank angle R11.
  • the valve 55 is instructed to open.
  • the control part 112 starts the operation
  • FIG. Based on this control, the first water injection pump 51 starts water injection to the first water injection position P1 of the fuel flow path. That is, the timing T11 of the crank angle R11 is the water injection start timing of the downstream side water injection system 50. At this timing T11, as shown in FIG. 9, the injection of water 203 into the first water injection position P1 in the fuel column 201 in the fuel flow path is started.
  • the fuel between the first water injection position P1 and the second water injection position P2 starts to be pushed back upstream in the flow direction beyond the second water injection position P2. . Accordingly, the fuel amount between the first water injection position P1 and the second water injection position P2 starts to be adjusted so as to decrease.
  • the water injection to the fuel column 201 is not started at the timing T0 within the period from the completion of the previous fuel injection to the water injection start timing (timing T11).
  • the fuel amount of the fuel column 201 at this time corresponds to the fuel injection amount Qfa described above.
  • the control unit 112 starts the water injection by the upstream side water injection system 60 at a timing delayed from the water injection start timing of the downstream side water injection system 50 for the waiting time ⁇ T11 minutes calculated as described above. Specifically, the control unit 112 converts the standby time ⁇ T11 of the upstream water injection system 60 into a crank angle change amount ⁇ R based on the engine speed corresponding to the engine load and the elapsed time of the engine rotation. The control unit 112 calculates the crank angle R12 by adding the obtained change amount ⁇ R of the crank angle and the crank angle R11 at the water injection start timing (timing T11) of the downstream water injection system 50. As shown in FIG.
  • the control unit 112 instructs the control valve 65 of the upstream water injection system 60 to open at timing T12 when the detected crank angle value becomes the crank angle R12. Thereby, the control unit 112 starts the operation of the second water injection pump 61 of the upstream side water injection system 60 while continuing the operation of the first water injection pump 51 of the downstream side water injection system 50. Based on this control, the second water injection pump 61 starts water injection to the second water injection position P2 of the fuel flow path. That is, the timing T12 of the crank angle R12 is the water injection start timing of the upstream water injection system 60.
  • the first water injection pump 51 continuously performs water injection to the first water injection position P1 of the fuel flow path. At this timing T12, as shown in FIG. 9, the water 203 is continuously injected into the first water injection position P1 in the fuel column 201 in the fuel flow path, and the water is supplied to the second water injection position P2. 202 injection has started.
  • the first water injection pump 51 continues to inject water into the first water injection position P1 of the fuel flow path until the control valve 55 is driven to close.
  • the second water injection pump 61 continues water injection to the second water injection position P2 of the fuel flow path until the control valve 65 is driven to close.
  • the injection of water 203 at the first water injection position P1 proceeds. Further, during this period, during the period of time ⁇ Ta from the crank angle R12 to the crank angle Ra (> R12), the injection of the water 203 at the first water injection position P1 proceeds and the water 202 at the second water injection position P2 is injected. Advances. With the injection of the water 203 at the first water injection position P1, the fuel between the first water injection position P1 and the second water injection position P2 is pushed back upstream in the flow direction beyond the second water injection position P2 or the water 202. . Thereby, the fuel amount between the 1st water injection position P1 and the 2nd water injection position P2 is adjusted so that it may reduce during the period of time (DELTA) T13.
  • DELTA period of time
  • the water 203 at the first water injection position P1 is injected until it spreads over the entire width direction of the fuel column 201.
  • the water 203 at the first water injection position P1 moves the fuel column 201 from the most downstream fuel 201c located downstream of the first water injection position P1 and from the first water injection position P1.
  • the fuel is divided into the upstream fuel 201e located on the upstream side. At this stage, the fuel amount of the most downstream fuel 201c is determined.
  • the water 203 at the first water injection position P1 is further injected from the state where it spreads over the entire width direction of the fuel column 201, and at the second water injection position P2. Of water 202 is continuously injected. In this stage, the injection of the water 203 at the first water injection position P1 is performed while pushing back the fuel between the first water injection position P1 and the second water injection position P2 to the upstream side in the flow direction from the second water injection position P2.
  • the water 202 at the second water injection position P2 is injected until it spreads over the entire width direction of the fuel column 201.
  • the water 202 at the second water injection position P2 includes the upstream fuel 201e of the fuel column 201, the upstream fuel 201b positioned upstream of the second water injection position P2, and the water at the second water injection position P2.
  • the fuel between the first water injection position P1 and the second water injection position P2 circulates over the water 202 at the second water injection position P2 even if the injection of the water 203 at the first water injection position P1 proceeds.
  • the timing of the crank angle Ra may be the same as the timing T14 when the required amount of water 202 at the second water injection position P2 is injected, may be the previous timing, or may be the subsequent timing. May be. Which of these timings corresponds to the crank angle Ra is determined by the waiting time ⁇ T11 corresponding to the engine load.
  • FIG. 9 illustrates a case where the timing of the crank angle Ra is the same as the timing T14 of the crank angle R14.
  • the control unit 112 instructs the control valve 55 of the downstream water injection system 50 to be closed at timing T14 when the crank angle detection value becomes the crank angle R14. Thereby, the control unit 112 stops the operation of the first water injection pump 51 of the downstream side water injection system 50 while continuing the operation of the second water injection pump 61 of the upstream side water injection system 60. Based on this control, the first water injection pump 51 ends water injection to the first water injection position P1 of the fuel flow path. That is, the timing T14 of the crank angle R14 is the water injection end timing of the downstream water injection system 50. On the other hand, the second water injection pump 61 continuously performs water injection to the second water injection position P2 of the fuel flow path. As shown in FIG. 9, at the timing T14 of the crank angle R14, a necessary amount of water 203 at the first water injection position P1 is injected.
  • the control unit 112 instructs the control valve 65 of the upstream water injection system 60 to be closed at a timing T15 when the crank angle detection value becomes the crank angle R15.
  • the control part 112 stops the operation
  • FIG. Based on this control, the second water injection pump 61 ends water injection to the second water injection position P2 of the fuel flow path. That is, the timing T15 of the crank angle R15 is the water injection end timing of the upstream water injection system 60.
  • the water 202 at the second water injection position P2 spreads over the entire width direction of the fuel column 201. It is further injected from the state.
  • the injection of the water 203 at the first water injection position P1 has already ended at the timing T14 described above.
  • the injection of the water 202 at the second water injection position P2 is performed in the same manner as the period from the timing T13 to the timing T14 described above, and is continued until the injection amount of the water 202 becomes a necessary amount.
  • each water injection of the 2nd water injection position P2 and the 1st water injection position P1 is completed.
  • a stratified liquid 200 composed of the first fuel layer F1, the first water injection layer W1, the second fuel layer F2, the second water injection layer W2, and the third fuel layer F3 is formed in the fuel flow path.
  • the water injection period of the downstream side water injection system 50 is a period from the timing T11 of the crank angle R11 to the timing T14 of the crank angle R14. That is, the water injection period of the downstream water injection system 50 is a period corresponding to the time obtained by adding the waiting time ⁇ T11 and the time ⁇ T12 shown in FIG.
  • This water injection period is determined by the time required for injecting a required amount of water 203 into the first water injection position P1 shown in FIG. That is, the crank angle R14 corresponding to the water injection end timing (timing T14) of the downstream side water injection system 50 is based on the crank angle R11 corresponding to the water injection start timing and the time required to inject the required amount of water 203. Derived.
  • the water injection period of the upstream water injection system 60 is a period from the timing T12 of the crank angle R12 to the timing T15 of the crank angle R15. This water injection period is determined by the time taken to inject the required amount of water 202 into the second water injection position P2 shown in FIG. That is, the crank angle R15 corresponding to the water injection end timing (timing T15) of the upstream water injection system 60 is based on the crank angle R12 corresponding to the water injection start timing and the time required for injecting the required amount of water 202. Derived.
  • the overlapping period of the water injection period of the downstream water injection system 50 and the water injection period of the upstream water injection system 60 corresponds to the time ⁇ T12 from the crank angle R12 to the crank angle R14 as shown in FIG. .
  • a period of time ⁇ Ta from the crank angle R12 to the crank angle Ra is a part of a period in which the fuel amount between the water injection layers is adjusted to be reduced by water injection from the downstream water injection system 50.
  • the period of the standby time ⁇ T11 from the crank angle R11 to the crank angle R12 is the remainder of the period during which the fuel amount between the water injection layers is adjusted to decrease.
  • a period of time ⁇ T13 obtained by adding the waiting time ⁇ T11 and time ⁇ Ta is an entire period in which the fuel amount between the water injection layers is adjusted to be reduced.
  • the water injection start timing of the upstream water injection system 60 waits from the water injection start timing of the downstream water injection system 50 so that the time ⁇ T13 decreases as the engine load increases and the time ⁇ T13 increases as the engine load decreases.
  • the timing is controlled to be delayed by time ⁇ T11. That is, this waiting time ⁇ T11 decreases with an increase in engine load, and increases with a decrease in engine load.
  • the water injection start timing of the upstream side water injection system 60 is controlled at the same time as the water injection start timing of the downstream side water injection system 50.
  • the fuel injection device 110 As described above, in the fuel injection device 110 according to Embodiment 2 of the present invention, at least a part of the water injection period of the downstream water injection system 50 and the water injection period of the upstream water injection system 60 overlap,
  • the standby time ⁇ T11 of the upstream side water injection system 60 from when the downstream side water injection system 50 starts water injection to when the upstream side water injection system 60 starts water injection is calculated according to the engine load, and the calculated standby time ⁇ T11 minutes, upstream
  • the water injection start timings of the downstream water injection system 50 and the upstream water injection system 60 are controlled so that the water injection start timing of the side water injection system 60 is delayed from the water injection start timing of the downstream water injection system 50, and the other embodiments Same as 1.
  • the upstream water injection system 60 is water-filled first for the time which can reduce the fuel quantity between water injection layers by the water injection of the downstream water injection system 50. Compared with the case where it does, it can adjust in a wide range, and it becomes possible to optimize easily the ratio of the fuel quantity between the water injection layers with respect to the fuel injection quantity according to engine load.
  • the water injection start standby time calculated according to the engine load (for example, ⁇ T1 or ⁇ T11).
  • the crank angle is calculated from the above, and the timing at which the obtained crank angle coincides with the crank angle detection value by the detector 91 is set as the water injection start timing following the previous water injection start timing.
  • the water injection start timings of the downstream water injection system 50 and the upstream water injection system 60 are controlled along the elapsed time (that is, the time axis) when the marine diesel engine rotates, and the elapsed time from the previous water injection start timing is controlled.
  • the timing when the standby time corresponding to the engine load is reached may be set as the subsequent water injection start timing.
  • the fuel injection device including the three fuel injection valves 30 is illustrated, but the present invention is not limited to this.
  • the number of fuel injection valves 30 is not limited to three, but may be one or more (two or more).
  • the present invention is not limited by the above-described first and second embodiments, and the present invention includes a configuration in which the above-described constituent elements are appropriately combined.
  • the present invention includes a configuration in which the above-described constituent elements are appropriately combined.
  • other embodiments, examples, operation techniques, and the like made by those skilled in the art based on Embodiments 1 and 2 described above are all included in the scope of the present invention.
  • the fuel injection device according to the present invention is useful for injecting fuel and water into the combustion chamber in the cylinder of the marine diesel engine, and in particular, adjusting the amount of fuel between the water injection layers according to the engine load.

Abstract

In this fuel injection device according to an aspect of the present invention, a fuel injection valve is provided in a marine diesel engine. A fuel injection pump pumps fuel to the fuel injection valve through piping. A first water injection system injects water at a predetermined position in a fuel circulation path extending from the fuel injection pump to an injection port of the fuel injection valve. A second water injection system injects water at a position which, in the fuel circulation path, is upstream of the first water injection system with respect to the fuel circulation direction. The control unit controls the respective water injection start timings of the first water injection system and the second water injection system according to engine load so that the water injection period of the first water injection system and the water injection period of the second water injection system overlap at least partially. The fuel injection valve injects the fuel, pumped by the fuel injection pump, the water, injected by the first water injection system, and the water, injected by the second water injection system, in a layered form from the injection port into a combustion chamber inside the cylinder.

Description

燃料噴射装置Fuel injection device
 本発明は、船舶に搭載される舶用ディーゼルエンジンの燃料噴射装置に関するものである。 The present invention relates to a fuel injection device for a marine diesel engine mounted on a marine vessel.
 従来、船舶の分野においては、舶用ディーゼルエンジンから排出される排ガス中の窒素酸化物(NOx)を低減する手法として、シリンダ内の燃焼室に燃料および水を噴射する水噴射技術が提案されている(例えば特許文献1~4参照)。 Conventionally, in the marine field, as a technique for reducing nitrogen oxides (NOx) in exhaust gas discharged from marine diesel engines, water injection technology for injecting fuel and water into a combustion chamber in a cylinder has been proposed. (For example, see Patent Documents 1 to 4).
 特許文献1~4に開示される水噴射技術では、燃料噴射ポンプから燃料噴射弁に圧送される燃料の流通経路内に水を注入する等して、この流通経路内に複数の燃料層と注水層(注入された水の層)とが交互に並ぶように燃料および水が多層液柱状に形成される。この多層液柱状の燃料および水は、これら複数の燃料層と注水層との並び順(例えば、燃料-水―燃料-水-燃料等の順序)で1つの燃料噴射弁からシリンダ内の燃焼室へ層状に噴射される。 In the water injection techniques disclosed in Patent Documents 1 to 4, a plurality of fuel layers and water injections are injected into the flow path by, for example, injecting water into the flow path of the fuel that is pumped from the fuel injection pump to the fuel injection valve. Fuel and water are formed in a multilayer liquid column shape so that the layers (injected water layers) are arranged alternately. The multilayer liquid columnar fuel and water are supplied from one fuel injection valve to the combustion chamber in the cylinder in the order in which the plurality of fuel layers and the water injection layer are arranged (for example, fuel-water-fuel-water-fuel, etc.). It is jetted in layers.
特開平6-123255号公報JP-A-6-123255 特開平6-257530号公報JP-A-6-257530 特開平4-175446号公報JP-A-4-175446 特開平5-288129号公報Japanese Patent Laid-Open No. 5-288129
 ところで、上述したように燃料および水が層状に噴射される水噴射技術において、燃料の流通経路内で各注水層に挟まれる燃料層の燃料の量(以下、注水層間の燃料量という)は、舶用ディーゼルエンジンの安定した性能を確保する等の観点から、極めて重要な因子である。すなわち、燃焼室への燃料の1回当りの噴射量(以下、燃料噴射量という)に対する注水層間の燃料量の割合が過大または過小である場合、舶用ディーゼルエンジンは、燃焼不良等を引き起こしたり、燃費の悪化等を招いたりする恐れがある。このような事態を回避するためには、燃料噴射量に対する割合が過大または過小とならないように注水層間の燃料量を調整できるようにすることが好ましい。 By the way, in the water injection technique in which fuel and water are injected in layers as described above, the amount of fuel in the fuel layer sandwiched between the water injection layers in the fuel flow path (hereinafter referred to as the fuel amount between the water injection layers) is: This is an extremely important factor from the viewpoint of ensuring stable performance of marine diesel engines. That is, when the ratio of the amount of fuel between the water injection layers to the amount of fuel injected into the combustion chamber (hereinafter referred to as the fuel injection amount) is excessive or excessive, the marine diesel engine may cause combustion failure, There is a risk of deteriorating fuel consumption. In order to avoid such a situation, it is preferable to be able to adjust the fuel amount between the water injection layers so that the ratio to the fuel injection amount does not become excessive or small.
 しかしながら、上述した従来技術では、燃料層を挟む下流側(燃料噴射弁の噴射口側)および上流側(燃料噴射ポンプ側)の各注水層のうち一方の注水層の注水が完了した後に他方の注水層の注水が行われているため、燃料噴射量に対する割合が過大または過小とならないように注水層間の燃料量を調整することは困難である。これに加え、燃料噴射量は、通常、舶用ディーゼルエンジンの負荷(以下、エンジン負荷と適宜いう)の増加に伴い増加し、減少に伴い減少する。このため、上述した従来技術では、ある特定のエンジン負荷時に注水層間の燃料量が燃料噴射量に対して過大でも過小でもない割合となっている可能性はあるものの、これ以外のエンジン負荷時には燃料噴射量に対する注水層間の燃料量の割合が過大または過小となっている場合が多く、エンジン負荷に応じて注水層間の燃料量を調整することは困難である。 However, in the above-described prior art, after the water injection of one of the water injection layers on the downstream side (fuel injection valve side) and the upstream side (fuel injection pump side) sandwiching the fuel layer is completed, the other water injection layer is completed. Since water injection is performed in the water injection layer, it is difficult to adjust the fuel amount between the water injection layers so that the ratio to the fuel injection amount does not become excessive or small. In addition, the fuel injection amount usually increases with an increase in the load of the marine diesel engine (hereinafter referred to as engine load as appropriate) and decreases with a decrease. For this reason, in the above-described prior art, there is a possibility that the fuel amount between the water injection layers is not excessive or small with respect to the fuel injection amount at a specific engine load. In many cases, the ratio of the fuel amount between the water injection layers to the injection amount is too large or too small, and it is difficult to adjust the fuel amount between the water injection layers according to the engine load.
 本発明は、上記の事情に鑑みてなされたものであって、エンジン負荷に応じて注水層間の燃料量を調整することができる燃料噴射装置を提供することを目的とする。 The present invention has been made in view of the above circumstances, and an object thereof is to provide a fuel injection device capable of adjusting the amount of fuel between the water injection layers in accordance with the engine load.
 上述した課題を解決し、目的を達成するために、本発明に係る燃料噴射装置は、舶用ディーゼルエンジンのシリンダに設けられる燃料噴射弁と、配管を通じて前記燃料噴射弁に燃料を圧送する燃料噴射ポンプと、前記燃料噴射ポンプから前記燃料噴射弁の噴射口に至る燃料流通経路の所定の位置に水を注入する第1の注水系統と、前記燃料流通経路のうち、前記第1の注水系統よりも前記燃料の流通方向上流側の位置に水を注入する第2の注水系統と、前記第1の注水系統の注水期間と前記第2の注水系統の注水期間との少なくとも一部が重なるように、前記舶用ディーゼルエンジンの負荷に応じて前記第1の注水系統および前記第2の注水系統の各注水開始タイミングを制御する制御部と、を備え、前記燃料噴射弁は、前記燃料噴射ポンプによって圧送された前記燃料と、前記第1の注水系統によって注入された水と、前記第2の注水系統によって注入された水とを前記噴射口から前記シリンダ内の燃焼室へ層状に噴射することを特徴とする。 In order to solve the above-described problems and achieve the object, a fuel injection device according to the present invention includes a fuel injection valve provided in a cylinder of a marine diesel engine, and a fuel injection pump that pumps fuel to the fuel injection valve through a pipe. A first water injection system for injecting water into a predetermined position of a fuel flow path from the fuel injection pump to the injection port of the fuel injection valve, and the fuel flow path more than the first water injection system. A second water injection system for injecting water into a position upstream of the fuel flow direction, and a water injection period of the first water injection system and a water injection period of the second water injection system overlap at least partly, A control unit that controls each water injection start timing of the first water injection system and the second water injection system according to a load of the marine diesel engine, and the fuel injection valve includes the fuel injection pump Injecting the fuel pumped by the water, the water injected by the first water injection system, and the water injected by the second water injection system into the combustion chamber in the cylinder from the injection port in a layered manner It is characterized by.
 また、本発明に係る燃料噴射装置は、上記の発明において、前記制御部は、前記第1の注水系統によって注入された水の層と前記第2の注水系統によって注入された水の層との間の燃料量が前記燃料の1回当りの噴射量に対して一定の割合となるように、前記第1の注水系統および前記第2の注水系統の各注水開始タイミングを制御することを特徴とする。 Moreover, in the fuel injection device according to the present invention, in the above invention, the control unit includes a layer of water injected by the first water injection system and a layer of water injected by the second water injection system. The timing of each water injection in the first water injection system and the second water injection system is controlled so that the fuel amount in between is a constant ratio to the fuel injection amount per one time. To do.
 また、本発明に係る燃料噴射装置は、上記の発明において、前記制御部は、前記舶用ディーゼルエンジンの負荷に応じて、前記第2の注水系統が注水を開始してから前記第1の注水系統が注水を開始するまでの前記第1の注水系統の待機時間を算出し、算出した前記待機時間分、前記第1の注水系統の注水開始タイミングを前記第2の注水系統の注水開始タイミングよりも遅らせることを特徴とする。 Moreover, in the fuel injection device according to the present invention, in the above invention, the control unit is configured such that the first water injection system after the second water injection system starts water injection according to a load of the marine diesel engine. Calculates the standby time of the first water injection system until the start of water injection, and the water injection start timing of the first water injection system is more than the water injection start timing of the second water injection system for the calculated standby time. It is characterized by delaying.
 また、本発明に係る燃料噴射装置は、上記の発明において、前記制御部は、前記舶用ディーゼルエンジンの負荷に応じて、前記第1の注水系統が注水を開始してから前記第2の注水系統が注水を開始するまでの前記第2の注水系統の待機時間を算出し、算出した前記待機時間分、前記第2の注水系統の注水開始タイミングを前記第1の注水系統の注水開始タイミングよりも遅らせることを特徴とする。 Moreover, the fuel injection device according to the present invention is the fuel injection apparatus according to the above invention, wherein the control unit is configured such that the second water injection system after the first water injection system starts water injection according to a load of the marine diesel engine. Calculates the standby time of the second water injection system until the start of water injection, and the water injection start timing of the second water injection system is calculated from the water injection start timing of the first water injection system by the calculated standby time. It is characterized by delaying.
 また、本発明に係る燃料噴射装置は、上記の発明において、前記第1の注水系統による注水量と前記第2の注水系統による注水量との比は一定であることを特徴とする。 Moreover, the fuel injection device according to the present invention is characterized in that, in the above-mentioned invention, a ratio between a water injection amount by the first water injection system and a water injection amount by the second water injection system is constant.
 本発明によれば、エンジン負荷に応じて注水層間の燃料量を調整することができるという効果を奏する。 According to the present invention, there is an effect that the amount of fuel between the water injection layers can be adjusted according to the engine load.
図1は、本発明の実施形態1に係る燃料噴射装置が適用された舶用ディーゼルエンジンの一構成例を示す模式図である。FIG. 1 is a schematic diagram illustrating a configuration example of a marine diesel engine to which a fuel injection device according to Embodiment 1 of the present invention is applied. 図2は、本発明の実施形態1に係る燃料噴射装置の一構成例を示す模式図である。FIG. 2 is a schematic diagram illustrating a configuration example of the fuel injection device according to the first embodiment of the present invention. 図3は、本発明の実施形態1における燃料流通経路内の層状液体の一構成例を示す図である。FIG. 3 is a diagram illustrating a configuration example of the layered liquid in the fuel flow path according to the first embodiment of the present invention. 図4は、本発明の実施形態1における注水タイミングの制御を説明するための図である。FIG. 4 is a diagram for explaining control of water injection timing in the first embodiment of the present invention. 図5は、本発明の実施形態1における注水層間の燃料量の調整を説明するための図である。FIG. 5 is a diagram for explaining the adjustment of the fuel amount between the water injection layers in the first embodiment of the present invention. 図6は、本発明の実施形態1における層状液体のエンジン負荷に応じた噴射量の一例を示す図である。FIG. 6 is a diagram illustrating an example of an injection amount according to the engine load of the stratified liquid according to the first embodiment of the present invention. 図7は、本発明の実施形態2に係る燃料噴射装置の一構成例を示す模式図である。FIG. 7 is a schematic diagram illustrating a configuration example of the fuel injection device according to the second embodiment of the present invention. 図8は、本発明の実施形態2における注水タイミングの制御を説明するための図である。FIG. 8 is a diagram for explaining control of water injection timing in the second embodiment of the present invention. 図9は、本発明の実施形態2における注水層間の燃料量の調整を説明するための図である。FIG. 9 is a diagram for explaining the adjustment of the fuel amount between the water injection layers in the second embodiment of the present invention.
 以下に、添付図面を参照して、本発明に係る燃料噴射装置の好適な実施形態について詳細に説明する。なお、本実施形態により、本発明が限定されるものではない。また、図面は模式的なものであり、各要素の寸法の関係、各要素の比率などは、現実のものとは異なる場合があることに留意する必要がある。図面の相互間においても、互いの寸法の関係や比率が異なる部分が含まれている場合がある。また、各図面において、同一構成部分には同一符号が付されている。 Hereinafter, preferred embodiments of a fuel injection device according to the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment. Also, the drawings are schematic, and it should be noted that the relationship between the dimensions of each element, the ratio of each element, and the like may differ from the actual ones. Even between the drawings, there are cases in which portions having different dimensional relationships and ratios are included. Moreover, in each drawing, the same code | symbol is attached | subjected to the same component.
(実施形態1)
 まず、本発明の実施形態1に係る燃料噴射装置が適用された舶用ディーゼルエンジンの構成について説明する。図1は、本発明の実施形態1に係る燃料噴射装置が適用された舶用ディーゼルエンジンの一構成例を示す模式図である。この舶用ディーゼルエンジン10は、プロペラ軸を介して船舶の推進用プロペラ(いずれも図示せず)を回転運動させる推進用の機関(主機関)である。例えば、舶用ディーゼルエンジン10は、ユニフロー掃排気式のクロスヘッド式ディーゼルエンジン等の2ストロークディーゼルエンジンである。
(Embodiment 1)
First, the configuration of a marine diesel engine to which the fuel injection device according to Embodiment 1 of the present invention is applied will be described. FIG. 1 is a schematic diagram illustrating a configuration example of a marine diesel engine to which a fuel injection device according to Embodiment 1 of the present invention is applied. The marine diesel engine 10 is a propulsion engine (main engine) that rotates a propeller (not shown) of a marine vessel through a propeller shaft. For example, the marine diesel engine 10 is a two-stroke diesel engine such as a uniflow scavenging crosshead diesel engine.
 図1に示すように、舶用ディーゼルエンジン10は、下方に位置する台板1と、台板1上に設けられる架構5と、架構5上に設けられるシリンダジャケット11とを備える。これらの台板1と架構5とシリンダジャケット11とは、上下方向に延在する複数のタイボルト(連結部材)21およびナット22により、一体に締結されて固定されている。また、舶用ディーゼルエンジン10は、シリンダジャケット11に設けられるシリンダ12と、シリンダ12内に設けられるピストン15と、ピストン15の往復運動に連動して回転する出力軸(例えばクランクシャフト2)とを備える。 As shown in FIG. 1, the marine diesel engine 10 includes a base plate 1 positioned below, a frame 5 provided on the base plate 1, and a cylinder jacket 11 provided on the frame 5. The base plate 1, the frame 5 and the cylinder jacket 11 are integrally fastened and fixed by a plurality of tie bolts (connecting members) 21 and nuts 22 extending in the vertical direction. The marine diesel engine 10 includes a cylinder 12 provided in the cylinder jacket 11, a piston 15 provided in the cylinder 12, and an output shaft (for example, a crankshaft 2) that rotates in conjunction with the reciprocating motion of the piston 15. .
 台板1は、舶用ディーゼルエンジン10のクランクケースを構成するものである。図1に示すように、台板1内には、クランク4を有するクランクシャフト2と軸受3とが設けられる。クランクシャフト2は、船舶の推進力を出力する出力軸の一例であり、軸受3によって回転自在に支持されている。このクランクシャフト2には、クランク4を介して連接棒6の下端部が回動自在に連結されている。 The base plate 1 constitutes a crankcase of the marine diesel engine 10. As shown in FIG. 1, a crankshaft 2 having a crank 4 and a bearing 3 are provided in the base plate 1. The crankshaft 2 is an example of an output shaft that outputs the propulsive force of the ship, and is rotatably supported by the bearing 3. A lower end portion of a connecting rod 6 is rotatably connected to the crankshaft 2 via a crank 4.
 架構5には、図1に示すように、連接棒6と、ガイド板7と、クロスヘッド8とが設けられる。架構5は、ピストン軸方向に沿って設けられるガイド板7が幅方向に間隔を空けて一対をなすように配置されている。連接棒6は、その下端部がクランクシャフト2に連接された態様で、一対のガイド板7の間に配置されている。クロスヘッド8には、ピストン棒16の下端部に接続されるクロスヘッドピン9と、連接棒6の上端部に接続されるクロスヘッド軸受(図示せず)とが、クロスヘッドピン9の下半部においてそれぞれ回動自在に連結される。このクロスヘッド8は、図1に示すように一対のガイド板7の間に配置され、この一対のガイド板7に沿って移動自在に支持されている。 As shown in FIG. 1, the frame 5 is provided with a connecting rod 6, a guide plate 7, and a crosshead 8. The frame 5 is arranged such that guide plates 7 provided along the piston axial direction form a pair with an interval in the width direction. The connecting rod 6 is disposed between the pair of guide plates 7 in such a manner that the lower end portion thereof is connected to the crankshaft 2. The cross head 8 includes a cross head pin 9 connected to the lower end portion of the piston rod 16 and a cross head bearing (not shown) connected to the upper end portion of the connecting rod 6 in the lower half of the cross head pin 9. Each is pivotably connected. As shown in FIG. 1, the cross head 8 is disposed between a pair of guide plates 7 and is supported so as to be movable along the pair of guide plates 7.
 シリンダジャケット11は、図1に示すように、架構5の上部に設けられ、シリンダ12を支持する。シリンダ12は、シリンダライナ13とシリンダカバー14とによって構成される筒状の構造体(気筒)であり、燃料を燃焼させるための燃焼室17を有する。シリンダライナ13は、例えば円筒形状の構造体であり、シリンダジャケット11内に配置される。シリンダライナ13の上部にはシリンダカバー14が固定され、これにより、シリンダライナ13内の空間部(燃焼室17等)が区画される。このシリンダライナ13の空間部内には、ピストン15がピストン軸方向(図1では上下方向)に往復運動自在に設けられる。このピストン15の下端部には、図1に示すように、ピストン棒16の上端部が連結されている。 As shown in FIG. 1, the cylinder jacket 11 is provided on the upper part of the frame 5 and supports the cylinder 12. The cylinder 12 is a cylindrical structure (cylinder) constituted by a cylinder liner 13 and a cylinder cover 14 and has a combustion chamber 17 for burning fuel. The cylinder liner 13 is, for example, a cylindrical structure and is disposed in the cylinder jacket 11. A cylinder cover 14 is fixed to an upper portion of the cylinder liner 13, and thereby a space portion (combustion chamber 17 and the like) in the cylinder liner 13 is partitioned. A piston 15 is provided in the space of the cylinder liner 13 so as to freely reciprocate in the piston axial direction (vertical direction in FIG. 1). As shown in FIG. 1, the upper end portion of the piston rod 16 is connected to the lower end portion of the piston 15.
 また、シリンダカバー14には、図1に示すように、排気弁18と動弁装置19とが設けられている。排気弁18は、シリンダ12内の燃焼室17に通じる排気管20の排気口(排気ポート)を開閉可能に閉止する弁である。動弁装置19は、排気弁18を開閉駆動させる装置である。燃焼室17は、このような排気弁18と、上述したシリンダライナ13、シリンダカバー14およびピストン15とによって囲まれた空間である。 The cylinder cover 14 is provided with an exhaust valve 18 and a valve gear 19 as shown in FIG. The exhaust valve 18 is a valve that closes an exhaust port (exhaust port) of the exhaust pipe 20 that communicates with the combustion chamber 17 in the cylinder 12 so as to be openable and closable. The valve gear 19 is a device that drives the exhaust valve 18 to open and close. The combustion chamber 17 is a space surrounded by the exhaust valve 18 and the cylinder liner 13, the cylinder cover 14, and the piston 15 described above.
 また、図1に示すように、舶用ディーゼルエンジン10は、燃料噴射弁30と、燃料噴射ポンプ41と、第1注水ポンプ51と、第2注水ポンプ61とを備える。燃料噴射弁30は、燃焼室17内に噴射口を向ける態様でシリンダ12(例えばシリンダカバー14)に設けられる。燃料噴射ポンプ41、第1注水ポンプ51および第2注水ポンプ61は、図1に示すように、シリンダ12の近傍に設けられる。図1には図示しないが、燃料噴射ポンプ41、第1注水ポンプ51および第2注水ポンプ61は、各々、配管等を介して燃料噴射弁30と連通可能に接続されている。燃料噴射ポンプ41は、配管等による流通経路を通じて燃料噴射弁30に燃料を適宜圧送する。第1注水ポンプ51および第2注水ポンプ61は、各々、燃料噴射ポンプ41によって圧送される燃料の流通経路内に蒸留水等の水を適宜注入する。例えば、第1注水ポンプ51による注水位置は、第2注水ポンプ61による注水位置よりも燃料の流通経路の下流側である。燃料噴射弁30は、燃料噴射ポンプ41によって圧送された燃料と、第1注水ポンプ51によって注入された水と、第2注水ポンプ61によって注入された水とを、燃料噴射ポンプ41の圧送作用により、燃焼室17へ交互に噴射(すなわち層状に噴射)する。 Further, as shown in FIG. 1, the marine diesel engine 10 includes a fuel injection valve 30, a fuel injection pump 41, a first water injection pump 51, and a second water injection pump 61. The fuel injection valve 30 is provided in the cylinder 12 (for example, the cylinder cover 14) in such a manner that the injection port faces the combustion chamber 17. The fuel injection pump 41, the first water injection pump 51, and the second water injection pump 61 are provided in the vicinity of the cylinder 12 as shown in FIG. Although not shown in FIG. 1, the fuel injection pump 41, the first water injection pump 51, and the second water injection pump 61 are each connected to the fuel injection valve 30 through a pipe or the like. The fuel injection pump 41 appropriately pumps fuel to the fuel injection valve 30 through a distribution path such as piping. Each of the first water injection pump 51 and the second water injection pump 61 appropriately injects water such as distilled water into the fuel flow path pumped by the fuel injection pump 41. For example, the water injection position by the first water injection pump 51 is downstream of the fuel injection path from the water injection position by the second water injection pump 61. The fuel injection valve 30 is configured to pump the fuel pumped by the fuel injection pump 41, the water injected by the first water injection pump 51, and the water injected by the second water injection pump 61 by the pumping action of the fuel injection pump 41. The fuel is alternately injected into the combustion chamber 17 (that is, injected in layers).
 上述したような構成を有する舶用ディーゼルエンジン10において、シリンダ12内の燃焼室17には、燃料噴射弁30から燃料および水が供給され、且つ、圧縮空気等の燃焼用ガスが掃気ポート等(図示せず)を通じて供給される。燃焼室17内においては、供給された燃料が燃焼用ガスによって燃焼するとともに、供給された水によって燃料の燃焼温度が低下してNOxの排出量が低減される。そして、燃焼室17での燃料の燃焼によって発生したエネルギーにより、ピストン15は、シリンダ12内をピストン軸方向に往復運動する。このとき、動弁装置19によって排気弁18が作動してシリンダ12が開放されると、燃料の燃焼によって生じた排ガスが排気管20に押し出される。一方、シリンダ12には、掃気ポートから新たに燃焼用ガスが導入される。 In the marine diesel engine 10 having the above-described configuration, fuel and water are supplied from the fuel injection valve 30 to the combustion chamber 17 in the cylinder 12, and combustion gas such as compressed air is supplied to the scavenging port or the like (see FIG. (Not shown). In the combustion chamber 17, the supplied fuel is combusted by the combustion gas, and the supplied water lowers the combustion temperature of the fuel to reduce the NOx emission amount. The piston 15 reciprocates in the direction of the piston axis in the cylinder 12 by the energy generated by the combustion of fuel in the combustion chamber 17. At this time, when the exhaust valve 18 is operated by the valve gear 19 and the cylinder 12 is opened, the exhaust gas generated by the combustion of the fuel is pushed out to the exhaust pipe 20. On the other hand, combustion gas is newly introduced into the cylinder 12 from the scavenging port.
 また、ピストン15が上述したようにピストン軸方向に往復運動すると、ピストン15とともにピストン棒16がピストン軸方向に往復運動する。これに伴い、クロスヘッド8は、ガイド板7に沿ってピストン軸方向に往復運動する。これにより、クロスヘッド8のクロスヘッドピン9は、クロスヘッド軸受を介して連接棒6に回転駆動力を加える。この回転駆動力により、連接棒6の下端部に接続されるクランク4がクランク運動(回転運動)し、この結果、クランクシャフト2が回転する。クランクシャフト2は、このようにピストン15の往復運動を回転運動に変換してプロペラ軸とともに船舶の推進用プロペラを回転させ、これにより、船舶の推進力を出力する。 When the piston 15 reciprocates in the piston axial direction as described above, the piston rod 16 reciprocates in the piston axial direction together with the piston 15. Accordingly, the crosshead 8 reciprocates in the piston axial direction along the guide plate 7. Thereby, the cross head pin 9 of the cross head 8 applies a rotational driving force to the connecting rod 6 via the cross head bearing. By this rotational driving force, the crank 4 connected to the lower end portion of the connecting rod 6 performs a crank motion (rotational motion), and as a result, the crankshaft 2 rotates. The crankshaft 2 thus converts the reciprocating motion of the piston 15 into a rotational motion and rotates the propeller for the ship along with the propeller shaft, thereby outputting the propulsive force of the ship.
 つぎに、本発明の実施形態1に係る燃料噴射装置の構成について説明する。図2は、本発明の実施形態1に係る燃料噴射装置の一構成例を示す模式図である。図2に示すように、この燃料噴射装置100は、複数(本実施形態1では3つ)の燃料噴射弁30と、燃料圧送系統40と、下流側注水系統50と、上流側注水系統60とを備える。また、燃料噴射装置100は、水供給ポンプ71と、給水管72と、逆止弁73a、73bと、蓄圧部81と、高圧ポンプ82と、検出部91と、制御部92とを備える。なお、図2において、実線矢印は燃料や水等の流体の流通を示し、破線矢印は電気信号線を示す。 Next, the configuration of the fuel injection device according to Embodiment 1 of the present invention will be described. FIG. 2 is a schematic diagram illustrating a configuration example of the fuel injection device according to the first embodiment of the present invention. As shown in FIG. 2, the fuel injection device 100 includes a plurality (three in the first embodiment) of fuel injection valves 30, a fuel pumping system 40, a downstream water injection system 50, and an upstream water injection system 60. Is provided. The fuel injection device 100 includes a water supply pump 71, a water supply pipe 72, check valves 73 a and 73 b, a pressure accumulating unit 81, a high pressure pump 82, a detecting unit 91, and a control unit 92. In FIG. 2, solid arrows indicate the flow of fluid such as fuel and water, and broken arrows indicate electric signal lines.
 複数の燃料噴射弁30は、舶用ディーゼルエンジン10のシリンダ12内の燃焼室17(図1参照)に燃料および水を層状に噴射するための噴射弁である。これら複数の燃料噴射弁30は、舶用ディーゼルエンジン10の複数(図1では1つのみ図示されている)のシリンダ12に各々設けられる。以下では、これら複数の燃料噴射弁30のうちの1つを例示して燃料噴射弁30の構成等を説明する。なお、これら複数の燃料噴射弁30は、各々同様に構成されている。 The plurality of fuel injection valves 30 are injection valves for injecting fuel and water in layers into the combustion chamber 17 (see FIG. 1) in the cylinder 12 of the marine diesel engine 10. The plurality of fuel injection valves 30 are respectively provided in a plurality (only one is shown in FIG. 1) of the marine diesel engine 10. Below, the structure of the fuel injection valve 30 etc. are demonstrated by exemplifying one of these several fuel injection valves 30. FIG. The plurality of fuel injection valves 30 are similarly configured.
 図2に示すように、燃料噴射弁30は、配管等を介して燃料圧送系統40の燃料噴射ポンプ41と連通可能に接続されている。燃料噴射弁30は、配管等を介して下流側注水系統50および上流側注水系統60と連通可能に接続されている。燃料噴射弁30は、燃料噴射ポンプ41によって圧送された燃料と、下流側注水系統50によって注入された水と、上流側注水系統60によって注入された水とを噴射口31からシリンダ12内の燃焼室17へ層状に噴射する。 As shown in FIG. 2, the fuel injection valve 30 is connected to a fuel injection pump 41 of the fuel pumping system 40 through a pipe or the like so as to be able to communicate therewith. The fuel injection valve 30 is connected to the downstream side water injection system 50 and the upstream side water injection system 60 through a pipe or the like so as to communicate with each other. The fuel injection valve 30 burns the fuel pumped by the fuel injection pump 41, the water injected by the downstream water injection system 50, and the water injected by the upstream water injection system 60 from the injection port 31 into the cylinder 12. Injected into the chamber 17 in layers.
 詳細には、図2に示すように、燃料噴射弁30は、噴射口31と、この噴射口31に通じる内部流通経路32、33と、逆止弁34a、34bとを有する。一方の内部流通経路32は、噴射対象の燃料および水を流通させるための流通経路である。この内部流通経路32は、一端部が燃料噴射弁30の噴射口31に接続され且つ他端部が燃料噴射管42(例えばその分岐管42a)に接続されている。また、この内部流通経路32の上流側の位置(本実施形態1では第1注水位置P1よりも上流側の第2注水位置P2)には、逆止弁34aを介して上流側注水系統60の配管(例えば上流側注水管62の分岐管62a)が接続されている。他方の内部流通経路33は、上記内部流通経路32に注入される水を流通させるための流通経路である。この内部流通経路33は、一端部が上記内部流通経路32の噴射口31近傍の位置(本実施形態1では第1注水位置P1)に接続され且つ他端部が下流側注水系統50の配管(例えば下流側注水管52の分岐管52a)に接続されている。 Specifically, as shown in FIG. 2, the fuel injection valve 30 includes an injection port 31, internal flow paths 32 and 33 that communicate with the injection port 31, and check valves 34 a and 34 b. One internal distribution path 32 is a distribution path for distributing fuel and water to be injected. The internal flow path 32 has one end connected to the injection port 31 of the fuel injection valve 30 and the other end connected to a fuel injection pipe 42 (for example, its branch pipe 42a). Further, an upstream side water injection system 60 is connected to a position upstream of the internal flow path 32 (in the first embodiment, a second water injection position P2 upstream from the first water injection position P1) via a check valve 34a. A pipe (for example, the branch pipe 62a of the upstream water injection pipe 62) is connected. The other internal flow path 33 is a flow path for flowing water injected into the internal flow path 32. One end of the internal flow path 33 is connected to a position near the injection port 31 of the internal flow path 32 (the first water injection position P1 in the first embodiment), and the other end is a pipe of the downstream water injection system 50 ( For example, it is connected to the branch pipe 52 a) of the downstream side water injection pipe 52.
 逆止弁34aは、上流側注水系統60から燃料噴射弁30の内部流通経路32に向かう水の流通を可能とし、この逆流を防止する。逆止弁34bは、内部流通経路33の中途部に設けられる。逆止弁34bは、下流側注水系統50から燃料噴射弁30の内部流通経路33を通じて内部流通経路32に向かう水の流通を可能とし、この逆流を防止する。 The check valve 34a allows water to flow from the upstream water injection system 60 toward the internal flow path 32 of the fuel injection valve 30, and prevents this backflow. The check valve 34 b is provided in the middle of the internal flow path 33. The check valve 34 b allows water to flow from the downstream water injection system 50 toward the internal flow path 32 through the internal flow path 33 of the fuel injection valve 30, and prevents this reverse flow.
 燃料圧送系統40は、燃料噴射弁30に燃料を圧送するための設備である。図2に示すように、燃料圧送系統40は、燃料噴射ポンプ41と、燃料噴射管42と、制御弁45とを備える。 The fuel pumping system 40 is a facility for pumping fuel to the fuel injection valve 30. As shown in FIG. 2, the fuel pumping system 40 includes a fuel injection pump 41, a fuel injection pipe 42, and a control valve 45.
 燃料噴射ポンプ41は、作動油の圧力を利用して燃料の圧送を行う油圧駆動式のポンプである。詳細には、燃料噴射ポンプ41は、配管等を通じて燃料タンク(図示せず)から燃料を受け入れる。燃料噴射ポンプ41は、この受け入れた燃料を、燃料噴射管42を通じて燃料噴射弁30に圧送する。また、燃料噴射ポンプ41の圧送作用は、噴射口31からシリンダ12内の燃焼室17に対する燃料および水の層状噴射を燃料噴射弁30に行わせる。 The fuel injection pump 41 is a hydraulically driven pump that pumps fuel using the pressure of hydraulic oil. Specifically, the fuel injection pump 41 receives fuel from a fuel tank (not shown) through a pipe or the like. The fuel injection pump 41 pumps the received fuel to the fuel injection valve 30 through the fuel injection pipe 42. Further, the pumping action of the fuel injection pump 41 causes the fuel injection valve 30 to perform a layered injection of fuel and water from the injection port 31 to the combustion chamber 17 in the cylinder 12.
 燃料噴射管42は、燃料噴射ポンプ41と燃料噴射弁30との間で燃料を流通させるための配管である。例えば、図2に示すように、燃料噴射管42の一端部は、燃料噴射ポンプ41の吐出口に接続されている。また、燃料噴射管42の中途部には、分岐部43が設けられている。燃料噴射管42は、この分岐部43から他端部に向かって複数の分岐管(本実施形態1では3つの分岐管42a、42b、42c)に分岐している。例えば、燃料噴射管42の分岐管42a、42b、42cのうち、分岐管42aは、図2に示すように1つの燃料噴射弁30の内部流通経路32に接続されている。燃料噴射管42は、分岐管42aを介して、この燃料噴射弁30と燃料噴射ポンプ41とを連通させる。これと同様に、残りの分岐管42b、42cは、他の各燃料噴射弁30に各々接続されている。 The fuel injection pipe 42 is a pipe for allowing fuel to flow between the fuel injection pump 41 and the fuel injection valve 30. For example, as shown in FIG. 2, one end of the fuel injection pipe 42 is connected to the discharge port of the fuel injection pump 41. A branch portion 43 is provided in the middle of the fuel injection pipe 42. The fuel injection pipe 42 is branched into a plurality of branch pipes (three branch pipes 42a, 42b, 42c in the first embodiment) from the branch part 43 toward the other end. For example, among the branch pipes 42a, 42b, and 42c of the fuel injection pipe 42, the branch pipe 42a is connected to the internal flow path 32 of one fuel injection valve 30 as shown in FIG. The fuel injection pipe 42 allows the fuel injection valve 30 and the fuel injection pump 41 to communicate with each other through the branch pipe 42a. Similarly, the remaining branch pipes 42b and 42c are connected to the other fuel injection valves 30, respectively.
 制御弁45は、蓄圧部81から燃料噴射ポンプ41への作動油の供給を制御するための弁である。具体的には、制御弁45は、電磁弁等の電動式の開閉弁によって構成され、図示しないが、制御弁45によって駆動されるロジック弁の開閉によって、図2に示すように、燃料噴射ポンプ41と蓄圧部81とを連通可能に設けられる。制御弁45は、燃料の噴射タイミングに開状態となって、蓄圧部81内の作動油を燃料噴射ポンプ41に供給する。燃料噴射ポンプ41は、この供給された作動油の圧力を利用して、燃料噴射弁30へ燃料を圧送する。一方、制御弁45は、燃料の噴射タイミング以外の期間、閉状態となって、蓄圧部81から燃料噴射ポンプ41への作動油の供給を停止する。このような制御弁45の開閉駆動のタイミングは、制御部92によって制御される。 The control valve 45 is a valve for controlling the supply of hydraulic oil from the pressure accumulating unit 81 to the fuel injection pump 41. Specifically, the control valve 45 is constituted by an electric on-off valve such as an electromagnetic valve, and although not shown, as shown in FIG. 2, the fuel injection pump is opened and closed by opening / closing a logic valve driven by the control valve 45. 41 and the pressure accumulating portion 81 are provided so as to communicate with each other. The control valve 45 is opened at the fuel injection timing, and supplies the hydraulic oil in the pressure accumulating unit 81 to the fuel injection pump 41. The fuel injection pump 41 pumps fuel to the fuel injection valve 30 using the pressure of the supplied hydraulic oil. On the other hand, the control valve 45 is closed during a period other than the fuel injection timing, and stops supplying hydraulic oil from the pressure accumulating unit 81 to the fuel injection pump 41. The timing for opening and closing the control valve 45 is controlled by the control unit 92.
 下流側注水系統50は、本実施形態1における燃料流通経路の第1注水位置P1に水を注入する第1の注水系統の一例である。図2に示すように、下流側注水系統50は、第1注水ポンプ51と、下流側注水管52と、逆止弁54と、制御弁55とを備える。 The downstream water injection system 50 is an example of a first water injection system that injects water into the first water injection position P1 of the fuel flow path in the first embodiment. As shown in FIG. 2, the downstream water injection system 50 includes a first water injection pump 51, a downstream water injection pipe 52, a check valve 54, and a control valve 55.
 第1注水ポンプ51は、作動油の圧力を利用して注水を行う油圧駆動式のポンプである。詳細には、第1注水ポンプ51は、給水管72等を通じて水供給ポンプ71から水を受け入れる。第1注水ポンプ51は、この受け入れた水を、下流側注水管52および燃料噴射弁30の内部流通経路33を通じて、燃料噴射弁30の内部流通経路32に圧送する。これにより、第1注水ポンプ51は、本実施形態1における燃料流通経路の第1注水位置P1に水を注入する。 The first water injection pump 51 is a hydraulic drive pump that performs water injection using the pressure of hydraulic oil. Specifically, the first water injection pump 51 receives water from the water supply pump 71 through the water supply pipe 72 and the like. The first water injection pump 51 pumps the received water to the internal flow path 32 of the fuel injection valve 30 through the downstream water supply pipe 52 and the internal flow path 33 of the fuel injection valve 30. Thereby, the 1st water injection pump 51 inject | pours water into the 1st water injection position P1 of the fuel distribution path in this Embodiment 1. FIG.
 下流側注水管52は、第1注水ポンプ51によって燃料流通経路の第1注水位置P1に注入される水を流通させるための配管である。例えば、図2に示すように、下流側注水管52の一端部は、第1注水ポンプ51の吐出口に接続されている。また、下流側注水管52の中途部には、分岐部53が設けられている。下流側注水管52は、この分岐部53から他端部に向かって複数の分岐管(本実施形態1では3つの分岐管52a、52b、52c)に分岐している。例えば、下流側注水管52の分岐管52a、52b、52cのうち、分岐管52aは、図2に示すように1つの燃料噴射弁30の内部流通経路33に接続されている。下流側注水管52は、分岐管52aを介して、この燃料噴射弁30の内部流通経路33と第1注水ポンプ51とを連通させる。これと同様に、残りの分岐管52b、52cは、他の各燃料噴射弁30に各々接続されている。 The downstream water injection pipe 52 is a pipe for circulating water injected by the first water injection pump 51 into the first water injection position P1 of the fuel distribution path. For example, as shown in FIG. 2, one end of the downstream water injection pipe 52 is connected to the discharge port of the first water injection pump 51. A branch portion 53 is provided in the middle of the downstream water injection pipe 52. The downstream side water injection pipe 52 is branched into a plurality of branch pipes (three branch pipes 52a, 52b, 52c in the first embodiment) from the branch part 53 toward the other end part. For example, among the branch pipes 52a, 52b, and 52c of the downstream water injection pipe 52, the branch pipe 52a is connected to the internal flow path 33 of one fuel injection valve 30 as shown in FIG. The downstream water injection pipe 52 allows the internal flow path 33 of the fuel injection valve 30 and the first water injection pump 51 to communicate with each other via the branch pipe 52a. Similarly, the remaining branch pipes 52b and 52c are connected to the other fuel injection valves 30, respectively.
 逆止弁54は、下流側注水管52内での水の流通方向を一方向に規制して水の逆流を防止するための弁である。図2に示すように、逆止弁54は、下流側注水管52の中途部(例えば第1注水ポンプ51と分岐部53との間の部位)に設けられる。逆止弁54は、第1注水ポンプ51側から燃料流通経路側(本実施形態1では燃料噴射弁30の内部流通経路32、33側)に向かう水の流通を可能とし、この逆流を防止する。 The check valve 54 is a valve for preventing the back flow of water by restricting the flow direction of the water in the downstream side water injection pipe 52 in one direction. As shown in FIG. 2, the check valve 54 is provided in a midway portion of the downstream side water injection pipe 52 (for example, a portion between the first water injection pump 51 and the branch portion 53). The check valve 54 allows water to flow from the first water injection pump 51 side toward the fuel flow path side (in the first embodiment, the internal flow paths 32 and 33 side of the fuel injection valve 30), and prevents this backflow. .
 制御弁55は、蓄圧部81から第1注水ポンプ51への作動油の供給を制御するための弁である。具体的には、制御弁55は、電磁弁等の電動式の開閉弁によって構成され、図2に示すように、第1注水ポンプ51と蓄圧部81とを連通可能に設けられる。制御弁55は、第1注水ポンプ51からの水を燃料流通経路に注入する期間(以下、下流側注水系統50の注水期間と適宜いう)に開状態となって、蓄圧部81内の作動油を第1注水ポンプ51に供給する。第1注水ポンプ51は、この供給された作動油の圧力を利用して、燃料流通経路の第1注水位置P1に水を圧送して注入する。一方、制御弁55は、下流側注水系統50の注水期間以外の期間、閉状態となって、蓄圧部81から第1注水ポンプ51への作動油の供給を停止する。このような制御弁55の開閉駆動のタイミングは、制御部92によって制御される。 The control valve 55 is a valve for controlling the supply of hydraulic oil from the pressure accumulating unit 81 to the first water injection pump 51. Specifically, the control valve 55 is configured by an electrically operated on-off valve such as an electromagnetic valve, and is provided so that the first water injection pump 51 and the pressure accumulating portion 81 can communicate with each other as shown in FIG. The control valve 55 is in an open state during a period for injecting water from the first water injection pump 51 into the fuel flow path (hereinafter referred to as a water injection period for the downstream side water injection system 50 as appropriate), and the hydraulic oil in the pressure accumulating unit 81. Is supplied to the first water injection pump 51. The first water injection pump 51 uses the pressure of the supplied hydraulic oil to pump and inject water into the first water injection position P1 of the fuel flow path. On the other hand, the control valve 55 is closed during a period other than the water injection period of the downstream side water injection system 50, and stops supplying hydraulic oil from the pressure accumulating unit 81 to the first water injection pump 51. The timing for opening and closing the control valve 55 is controlled by the control unit 92.
 上流側注水系統60は、本実施形態1における燃料流通経路の第2注水位置P2に水を注入する第2の注水系統の一例である。図2に示すように、上流側注水系統60は、第2注水ポンプ61と、上流側注水管62と、逆止弁64と、制御弁65とを備える。 The upstream water injection system 60 is an example of a second water injection system that injects water into the second water injection position P2 of the fuel flow path in the first embodiment. As shown in FIG. 2, the upstream water injection system 60 includes a second water injection pump 61, an upstream water injection pipe 62, a check valve 64, and a control valve 65.
 第2注水ポンプ61は、作動油の圧力を利用して注水を行う油圧駆動式のポンプである。詳細には、第2注水ポンプ61は、給水管72等を通じて水供給ポンプ71から水を受け入れる。第2注水ポンプ61は、この受け入れた水を、上流側注水管62を通じて燃料噴射弁30の内部流通経路32に圧送する。これにより、第2注水ポンプ61は、本実施形態1における燃料流通経路の第2注水位置P2に水を注入する。 The second water injection pump 61 is a hydraulically driven pump that performs water injection using the pressure of hydraulic oil. Specifically, the second water injection pump 61 receives water from the water supply pump 71 through the water supply pipe 72 and the like. The second water injection pump 61 pumps the received water to the internal flow path 32 of the fuel injection valve 30 through the upstream side water injection pipe 62. As a result, the second water injection pump 61 injects water into the second water injection position P2 of the fuel flow path in the first embodiment.
 上流側注水管62は、第2注水ポンプ61によって燃料流通経路の第2注水位置P2に注入される水を流通させるための配管である。例えば、図2に示すように、上流側注水管62の一端部は、第2注水ポンプ61の吐出口に接続されている。また、上流側注水管62の中途部には、分岐部63が設けられている。上流側注水管62は、この分岐部63から他端部に向かって複数の分岐管(本実施形態1では3つの分岐管62a、62b、62c)に分岐している。例えば、上流側注水管62の分岐管62a、62b、62cのうち、分岐管62aは、図2に示すように逆止弁34aを介して1つの燃料噴射弁30の内部流通経路32に接続されている。上流側注水管62は、分岐管62aを介して、この燃料噴射弁30の内部流通経路32と第2注水ポンプ61とを連通させる。これと同様に、残りの分岐管62b、62cは、他の各燃料噴射弁30に各々接続されている。 The upstream water injection pipe 62 is a pipe for circulating water injected by the second water injection pump 61 into the second water injection position P2 of the fuel distribution path. For example, as shown in FIG. 2, one end of the upstream water injection pipe 62 is connected to the discharge port of the second water injection pump 61. A branch portion 63 is provided in the middle of the upstream side water injection pipe 62. The upstream water injection pipe 62 is branched into a plurality of branch pipes (three branch pipes 62a, 62b, 62c in the first embodiment) from the branch part 63 toward the other end part. For example, among the branch pipes 62a, 62b, and 62c of the upstream water injection pipe 62, the branch pipe 62a is connected to the internal flow path 32 of one fuel injection valve 30 via the check valve 34a as shown in FIG. ing. The upstream water injection pipe 62 communicates the internal flow path 32 of the fuel injection valve 30 and the second water injection pump 61 via the branch pipe 62a. Similarly, the remaining branch pipes 62b and 62c are connected to the other fuel injection valves 30, respectively.
 逆止弁64は、上流側注水管62内での水の流通方向を一方向に規制して水の逆流を防止するための弁である。図2に示すように、逆止弁64は、上流側注水管62の中途部(例えば第2注水ポンプ61と分岐部63との間の部位)に設けられる。逆止弁64は、第2注水ポンプ61側から燃料流通経路側(本実施形態1では燃料噴射弁30の内部流通経路32側)に向かう水の流通を可能とし、この逆流を防止する。 The check valve 64 is a valve for preventing the reverse flow of water by restricting the flow direction of the water in the upstream side water injection pipe 62 in one direction. As shown in FIG. 2, the check valve 64 is provided in a midway part of the upstream water injection pipe 62 (for example, a part between the second water injection pump 61 and the branch part 63). The check valve 64 allows water to flow from the second water injection pump 61 side toward the fuel flow path side (in the first embodiment, the internal flow path 32 side of the fuel injection valve 30), and prevents this backflow.
 制御弁65は、蓄圧部81から第2注水ポンプ61への作動油の供給を制御するための弁である。具体的には、制御弁65は、電磁弁等の電動式の開閉弁によって構成され、図2に示すように、第2注水ポンプ61と蓄圧部81とを連通可能に設けられる。制御弁65は、第2注水ポンプ61からの水を燃料流通経路に注入する期間(以下、上流側注水系統60の注水期間と適宜いう)に開状態となって、蓄圧部81内の作動油を第2注水ポンプ61に供給する。第2注水ポンプ61は、この供給された作動油の圧力を利用して、燃料流通経路の第2注水位置P2に水を圧送して注入する。一方、制御弁65は、上流側注水系統60の注水期間以外の期間、閉状態となって、蓄圧部81から第2注水ポンプ61への作動油の供給を停止する。このような制御弁65の開閉駆動のタイミングは、制御部92によって制御される。 The control valve 65 is a valve for controlling the supply of hydraulic oil from the pressure accumulating unit 81 to the second water injection pump 61. Specifically, the control valve 65 is configured by an electrically operated on-off valve such as an electromagnetic valve, and is provided so that the second water injection pump 61 and the pressure accumulating portion 81 can communicate with each other as shown in FIG. The control valve 65 is in an open state during a period of injecting water from the second water injection pump 61 into the fuel flow path (hereinafter referred to as a water injection period of the upstream water injection system 60 as appropriate), and the hydraulic oil in the pressure accumulating unit 81 is opened. Is supplied to the second water injection pump 61. The second water injection pump 61 uses the pressure of the supplied hydraulic oil to pump and inject water into the second water injection position P2 of the fuel flow path. On the other hand, the control valve 65 is closed during a period other than the water injection period of the upstream water injection system 60, and stops the supply of hydraulic oil from the pressure accumulating unit 81 to the second water injection pump 61. The timing for opening and closing the control valve 65 is controlled by the control unit 92.
 ここで、本実施形態1における燃料流通経路は、燃料噴射ポンプ41から燃料噴射弁30の噴射口31に至る燃料の流通経路である。例えば、この燃料流通経路は、分岐管42a~42c等を含む燃料噴射管42と、燃料噴射弁30の内部流通経路32とによって形成される。第1注水位置P1は、この燃料流通経路における所定の位置である。本実施形態1において、第1注水位置P1は、例えば図2に示すように、燃料噴射弁30の内部流通経路32のうち噴射口31近傍の位置、すなわち、燃料流通経路における燃料の流通方向最下流に存在する所定量の燃料(後述の図3に示す第1燃料層F1の燃料)の直近上流の位置である。第2注水位置P2は、この燃料流通経路のうち、下流側注水系統50よりも燃料の流通方向上流側の位置である。本実施形態1において、第2注水位置P2は、例えば図2に示すように、燃料噴射弁30の内部流通経路32のうち燃料噴射ポンプ41側の位置、すなわち、第1注水位置P1よりも燃料の流通方向上流側の位置である。なお、本実施形態1において、燃料の流通方向は、燃料噴射ポンプ41から燃料噴射管42等を通じて燃料噴射弁30の噴射口31に向かう方向である。 Here, the fuel flow path in the first embodiment is a fuel flow path from the fuel injection pump 41 to the injection port 31 of the fuel injection valve 30. For example, this fuel flow path is formed by the fuel injection pipe 42 including the branch pipes 42 a to 42 c and the internal flow path 32 of the fuel injection valve 30. The first water injection position P1 is a predetermined position in this fuel flow path. In the first embodiment, for example, as shown in FIG. 2, the first water injection position P1 is a position in the vicinity of the injection port 31 in the internal flow path 32 of the fuel injection valve 30, that is, the most fuel flow direction in the fuel flow path. This is the position immediately upstream of a predetermined amount of fuel (a fuel in a first fuel layer F1 shown in FIG. 3 described later) existing downstream. The second water injection position P2 is a position on the upstream side in the fuel flow direction of the downstream water injection system 50 in the fuel flow path. In the first embodiment, the second water injection position P2 is, for example, as shown in FIG. 2, the fuel injection valve 41 side position in the internal flow path 32 of the fuel injection valve 30, that is, the fuel from the first water injection position P1. It is a position of the distribution direction upstream side. In the first embodiment, the fuel flow direction is a direction from the fuel injection pump 41 toward the injection port 31 of the fuel injection valve 30 through the fuel injection pipe 42 and the like.
 水供給ポンプ71は、上述した燃料流通経路に注入される水を第1注水ポンプ51および第2注水ポンプ61に供給するためのポンプである。図2に示すように、水供給ポンプ71は、給水管72等を介して第1注水ポンプ51および第2注水ポンプ61と連通可能に接続される。給水管72の一端部は、水供給ポンプ71に接続されている。また、給水管72は、中途部で分岐管72a、72bに分岐している。給水管72の一方の分岐管72aは、逆止弁73aを介して第1注水ポンプ51に接続されている。給水管72の他方の分岐管72bは、逆止弁73bを介して第2注水ポンプ61に接続されている。水供給ポンプ71は、給水タンク(図示せず)に貯留されている水を、給水管72の分岐管72a等を通じて第1注水ポンプ51に供給するとともに、給水管72の分岐管72b等を通じて第2注水ポンプ61に供給する。逆止弁73aは、水供給ポンプ71側から第1注水ポンプ51側に向かう水の流通を可能とし、この逆流を防止する。逆止弁73bは、水供給ポンプ71側から第2注水ポンプ61側に向かう水の流通を可能とし、この逆流を防止する。 The water supply pump 71 is a pump for supplying the water injected into the above-described fuel flow path to the first water injection pump 51 and the second water injection pump 61. As shown in FIG. 2, the water supply pump 71 is connected to the first water injection pump 51 and the second water injection pump 61 through a water supply pipe 72 and the like so as to communicate with each other. One end of the water supply pipe 72 is connected to the water supply pump 71. Moreover, the water supply pipe 72 is branched into the branch pipes 72a and 72b in the middle. One branch pipe 72a of the water supply pipe 72 is connected to the first water injection pump 51 via a check valve 73a. The other branch pipe 72b of the water supply pipe 72 is connected to the second water injection pump 61 via a check valve 73b. The water supply pump 71 supplies water stored in a water supply tank (not shown) to the first water injection pump 51 through the branch pipe 72a of the water supply pipe 72 and the like through the branch pipe 72b of the water supply pipe 72. 2 Supply to water injection pump 61. The check valve 73a allows water to flow from the water supply pump 71 side to the first water injection pump 51 side, and prevents this backflow. The check valve 73b allows water to flow from the water supply pump 71 side to the second water injection pump 61 side, and prevents this backflow.
 蓄圧部81は、燃料圧送系統40、下流側注水系統50および上流側注水系統60を各々作動させる作動油の圧力を蓄積するものである。蓄圧部81は、作動油を貯蔵可能な蓄圧室を内部に形成する中空の構造体であり、図2に示すように、配管等を介して高圧ポンプ82と連通可能に接続される。蓄圧部81は、高圧ポンプ82から吐出(圧送)された作動油を内部の蓄圧室に貯留し、これにより、作動油の圧力を蓄積する。このように蓄圧部81に蓄積される作動油の圧力は、高圧ポンプ82から蓄圧部81への作動油の吐出量によって調整される。蓄圧部81に蓄積された作動油の圧力は、燃料圧送系統40の燃料噴射ポンプ41の作動と、下流側注水系統50の第1注水ポンプ51の作動と、上流側注水系統60の第2注水ポンプ61の作動とに共用される。 The pressure accumulating unit 81 accumulates the pressure of hydraulic oil that operates the fuel pumping system 40, the downstream water injection system 50, and the upstream water injection system 60. The pressure accumulating portion 81 is a hollow structure that internally forms a pressure accumulating chamber capable of storing hydraulic oil, and is connected to a high pressure pump 82 via a pipe or the like as shown in FIG. The pressure accumulating unit 81 stores the hydraulic oil discharged (pressure-fed) from the high-pressure pump 82 in an internal pressure accumulating chamber, thereby accumulating the pressure of the hydraulic oil. Thus, the pressure of the hydraulic oil accumulated in the pressure accumulating portion 81 is adjusted by the discharge amount of the hydraulic oil from the high pressure pump 82 to the pressure accumulating portion 81. The pressure of the hydraulic oil accumulated in the pressure accumulating portion 81 is the operation of the fuel injection pump 41 of the fuel pumping system 40, the operation of the first water injection pump 51 of the downstream water injection system 50, and the second water injection of the upstream water injection system 60. It is shared with the operation of the pump 61.
 検出部91は、舶用ディーゼルエンジン10(図1参照)のクランク角度を検出するものである。本実施形態1において、検出部91は、シリンダ12内でのピストン15の1サイクルの往復運動に伴って回転運動するクランク4の回転角度(すなわちクランク角度)を検出する。この際、検出部91は、クランク4の基準状態からの回転角度をクランク角度として検出する。なお、クランク4の基準状態としては、例えば、ピストン15が下死点または上死点に位置する際のクランク4の状態等が挙げられる。検出部91は、時間の経過に伴ってクランク角度を検出し、その都度、検出したクランク角度を示す電気信号を制御部92に送信する。 Detecting unit 91 detects the crank angle of marine diesel engine 10 (see FIG. 1). In the first embodiment, the detection unit 91 detects the rotation angle (that is, the crank angle) of the crank 4 that rotates in association with the reciprocating motion of the piston 15 in the cylinder 12 in one cycle. At this time, the detection unit 91 detects the rotation angle of the crank 4 from the reference state as the crank angle. The reference state of the crank 4 includes, for example, the state of the crank 4 when the piston 15 is located at the bottom dead center or the top dead center. The detection unit 91 detects a crank angle as time passes, and transmits an electric signal indicating the detected crank angle to the control unit 92 each time.
 制御部92は、燃料および水の層状噴射タイミングと、下流側注水系統50の注水タイミングと、上流側注水系統60の注水タイミングとを制御する。本実施形態1において、燃料および水の層状噴射タイミングは、舶用ディーゼルエンジン10のシリンダ12内の燃焼室17(図1参照)へ燃料噴射弁30から燃料および水を層状に噴射するタイミングを意味する。下流側注水系統50の注水タイミングは、第1注水ポンプ51によって燃料流通経路の第1注水位置P1に注水を開始する注水開始タイミングと、この第1注水位置P1への注水を終了する注水終了タイミングとを意味する。上流側注水系統60の注水タイミングは、第2注水ポンプ61によって燃料流通経路の第2注水位置P2に注水を開始する注水開始タイミングと、この第2注水位置P2への注水を終了する注水終了タイミングとを意味する。 The controller 92 controls the fuel and water layer injection timing, the water injection timing of the downstream water injection system 50, and the water injection timing of the upstream water injection system 60. In the first embodiment, the layered injection timing of fuel and water means the timing at which fuel and water are injected in layers from the fuel injection valve 30 into the combustion chamber 17 (see FIG. 1) in the cylinder 12 of the marine diesel engine 10. . The water injection timing of the downstream side water injection system 50 is the water injection start timing at which the first water injection pump 51 starts water injection at the first water injection position P1 of the fuel flow path and the water injection end timing at which water injection to the first water injection position P1 is ended. Means. The water injection timing of the upstream water injection system 60 is the water injection start timing at which water injection is started to the second water injection position P2 of the fuel flow path by the second water injection pump 61, and the water injection end timing at which water injection to the second water injection position P2 is ended. Means.
 具体的には、制御部92は、各種プログラムを実行するためのCPU、メモリおよびシーケンサ等によって構成される。制御部92は、検出部91から電気信号を受信し、受信した電気信号に示されるクランク角度が所定の回転角度となるタイミングに開状態となるように、燃料圧送系統40の制御弁45の開閉駆動を制御する。制御部92は、この制御弁45の開閉駆動の制御を通して、燃料噴射ポンプ41の作動タイミングを制御する。これにより、制御部92は、燃料噴射弁30から燃焼室17への燃料および水の層状噴射タイミングを制御する。 Specifically, the control unit 92 includes a CPU, a memory, a sequencer, and the like for executing various programs. The control unit 92 receives the electrical signal from the detection unit 91, and opens and closes the control valve 45 of the fuel pumping system 40 so that the crank angle indicated by the received electrical signal becomes an opening state at a predetermined rotation angle. Control the drive. The control unit 92 controls the operation timing of the fuel injection pump 41 through control of the opening / closing drive of the control valve 45. Thereby, the control part 92 controls the layered injection timing of the fuel and water from the fuel injection valve 30 to the combustion chamber 17.
 この層状噴射タイミングでは、燃料噴射ポンプ41によって燃料流通経路に圧送された燃料のうちエンジン負荷に応じた必要量の燃料と、第1注水ポンプ51によって燃料流通経路の第1注水位置P1に注入された水と、第2注水ポンプ61によって燃料流通経路の第2注水位置P2に注入された水とが、燃料噴射ポンプ41の圧送作用によって燃料噴射弁30から燃焼室17へ層状に噴射される。その後、この燃料流通経路(本実施形態1では燃料噴射管42および燃料噴射弁30の内部流通経路32によって構成される燃料流通経路)は、噴射されずに残った燃料で満たされた状態となる。 At this stratified injection timing, a required amount of fuel corresponding to the engine load out of the fuel pumped to the fuel flow path by the fuel injection pump 41 and the first water injection pump 51 are injected into the first water injection position P1 of the fuel flow path. The water injected into the second water injection position P2 of the fuel flow path by the second water injection pump 61 is injected in layers from the fuel injection valve 30 to the combustion chamber 17 by the pumping action of the fuel injection pump 41. Thereafter, this fuel flow path (the fuel flow path constituted by the fuel injection pipe 42 and the internal flow path 32 of the fuel injection valve 30 in the first embodiment) is filled with the remaining fuel without being injected. .
 また、制御部92は、上述した燃料および水の層状噴射タイミング以外の期間において、燃料で満たされた状態にある燃料流通経路の第1注水位置P1および第2注水位置P2に水を各々注入するように、下流側注水系統50の注水タイミングおよび上流側注水系統60の注水タイミングを制御する。この際、制御部92は、下流側注水系統50の注水期間と上流側注水系統60の注水期間との少なくとも一部が重なるように、舶用ディーゼルエンジン10のエンジン負荷に応じて、下流側注水系統50の第1注水ポンプ51による注水開始タイミングと上流側注水系統60の第2注水ポンプ61による注水開始タイミングと制御する。 Moreover, the control part 92 inject | pours water into the 1st water injection position P1 and the 2nd water injection position P2 of the fuel distribution path which are in the state filled with fuel, respectively in periods other than the layered injection timing of the fuel and water mentioned above. Thus, the water injection timing of the downstream side water injection system 50 and the water injection timing of the upstream side water injection system 60 are controlled. At this time, the control unit 92 sets the downstream side water injection system according to the engine load of the marine diesel engine 10 so that at least a part of the water injection period of the downstream side water injection system 50 and the water injection period of the upstream side water injection system 60 overlap. The water injection start timing by 50 first water injection pumps 51 and the water injection start timing by second water injection pump 61 of upstream water injection system 60 are controlled.
 本実施形態1では、燃料で満たされた状態にある燃料流通経路の第1注水位置P1および第2注水位置P2に水を各々注入することにより、これらの燃料および水の各層からなる層状液体が燃料流通経路内に形成される。図3は、本発明の実施形態1における燃料流通経路内の層状液体の一構成例を示す図である。図3において、噴射口側は、燃料噴射弁30の噴射口31側、すなわち、燃料流通経路における燃料の流通方向下流側である。燃料噴射ポンプ側は、燃料圧送系統40の燃料噴射ポンプ41側、すなわち、燃料流通経路における燃料の流通方向上流側である。図3に示すように、この層状液体200は、噴射口側から燃料噴射ポンプ側に向かって並ぶ複数の液体層、例えば、第1液体層L1、第2液体層L2、第3液体層L3、第4液体層L4および第5液体層L5によって構成される。 In the first embodiment, by injecting water into the first water injection position P1 and the second water injection position P2 of the fuel flow path in a state filled with fuel, the layered liquid composed of these fuel and each layer of water is obtained. It is formed in the fuel flow path. FIG. 3 is a diagram illustrating a configuration example of the layered liquid in the fuel flow path according to the first embodiment of the present invention. In FIG. 3, the injection port side is the injection port 31 side of the fuel injection valve 30, that is, the downstream side in the fuel flow direction in the fuel flow path. The fuel injection pump side is the fuel injection pump 41 side of the fuel pumping system 40, that is, the upstream side in the fuel distribution direction in the fuel distribution path. As shown in FIG. 3, the stratified liquid 200 includes a plurality of liquid layers arranged from the injection port side toward the fuel injection pump side, for example, a first liquid layer L1, a second liquid layer L2, a third liquid layer L3, The fourth liquid layer L4 and the fifth liquid layer L5 are configured.
 第1液体層L1は、層状液体200のうち最下流の液体層である。層状液体200は、この第1液体層L1として第1燃料層F1を含む。第1燃料層F1は、層状液体200に含まれる複数(図3では3つ)の燃料層のうち、噴射口側から数えて1層目の燃料層であり、燃料の流通方向最下流に存在する所定量の燃料からなる。 The first liquid layer L1 is the most downstream liquid layer in the layered liquid 200. The stratified liquid 200 includes a first fuel layer F1 as the first liquid layer L1. The first fuel layer F1 is the first fuel layer of the plurality (three in FIG. 3) of fuel layers included in the stratified liquid 200, counted from the injection port side, and exists at the most downstream in the fuel flow direction. A predetermined amount of fuel.
 第2液体層L2は、層状液体200のうち第1液体層L1の直近上流の液体層である。層状液体200は、この第2液体層L2として第1注水層W1を含む。第1注水層W1は、層状液体200に含まれる複数(図3では2つ)の注水層のうち、噴射口側から数えて1層目の注水層である。この第1注水層W1は、第1注水ポンプ51によって燃料流通経路の第1注水位置P1に必要量の水が注入されることにより形成される。 The second liquid layer L2 is a liquid layer immediately upstream of the first liquid layer L1 in the layered liquid 200. The layered liquid 200 includes a first water injection layer W1 as the second liquid layer L2. The first water injection layer W1 is a first water injection layer counted from the injection port side among a plurality (two in FIG. 3) of water injection layers included in the layered liquid 200. The first water injection layer W1 is formed by injecting a necessary amount of water into the first water injection position P1 of the fuel circulation path by the first water injection pump 51.
 第3液体層L3は、層状液体200のうち第2液体層L2の直近上流の液体層である。層状液体200は、この第3液体層L3として第2燃料層F2を含む。第2燃料層F2は、層状液体200に含まれる複数の燃料層のうち、噴射口側から数えて2層目の燃料層である。この第2燃料層F2は、燃料流通経路の第1注水位置P1に注入された水の層と第2注水位置P2に注入された水の層との間に挟まれた燃料からなる。 The third liquid layer L3 is a liquid layer immediately upstream of the second liquid layer L2 in the layered liquid 200. The stratified liquid 200 includes a second fuel layer F2 as the third liquid layer L3. The second fuel layer F2 is a second fuel layer among the plurality of fuel layers included in the layered liquid 200, counted from the injection port side. The second fuel layer F2 is made of fuel sandwiched between a layer of water injected into the first water injection position P1 and a layer of water injected into the second water injection position P2 of the fuel flow path.
 第4液体層L4は、層状液体200のうち第3液体層L3の直近上流の液体層である。層状液体200は、この第4液体層L4として第2注水層W2を含む。第2注水層W2は、層状液体200に含まれる複数の注水層のうち、噴射口側から数えて2層目の注水層である。この第2注水層W2は、第2注水ポンプ61によって燃料流通経路の第2注水位置P2に必要量の水が注入されることにより形成される。 The fourth liquid layer L4 is a liquid layer immediately upstream of the third liquid layer L3 in the layered liquid 200. The layered liquid 200 includes a second water injection layer W2 as the fourth liquid layer L4. The second water injection layer W <b> 2 is a second water injection layer counted from the injection port side among the plurality of water injection layers included in the layered liquid 200. The second water injection layer W2 is formed by injecting a necessary amount of water into the second water injection position P2 of the fuel flow path by the second water injection pump 61.
 第5液体層L5は、層状液体200のうち最上流の液体層である。層状液体200は、この第5液体層L5として第3燃料層F3を含む。第3燃料層F3は、層状液体200に含まれる複数の燃料層のうち、噴射口側から数えて3層目の燃料層である。この第3燃料層F3は、第2注水層W2の直近上流に存在する燃料からなる。 The fifth liquid layer L5 is the most upstream liquid layer in the layered liquid 200. The layered liquid 200 includes a third fuel layer F3 as the fifth liquid layer L5. The third fuel layer F3 is a third fuel layer counted from the injection port side among the plurality of fuel layers included in the layered liquid 200. The third fuel layer F3 is made of fuel that exists immediately upstream of the second water injection layer W2.
 このような燃料および水の層状液体200は、ピストン15の1サイクルの往復運動毎に、燃料噴射弁30の噴射口31からシリンダ12内の燃焼室17へ噴射される。このとき、燃焼室17に対する燃料の1回当りの噴射量、すなわち、層状液体200の燃料噴射量Qfaは、第1燃料層F1の燃料量Qf1と第2燃料層F2の燃料量Qf2と第3燃料層F3の燃料量Qf3との和(=Qf1+Qf2+Qf3)によって表される。この層状液体200の燃料噴射量Qfaは、エンジン負荷の増加に伴って増加し、減少に伴って減少する。 Such a layered liquid 200 of fuel and water is injected from the injection port 31 of the fuel injection valve 30 into the combustion chamber 17 in the cylinder 12 for each reciprocation of the piston 15 in one cycle. At this time, the injection amount of fuel into the combustion chamber 17 per one time, that is, the fuel injection amount Qfa of the stratified liquid 200 is equal to the fuel amount Qf1 of the first fuel layer F1, the fuel amount Qf2 of the second fuel layer F2, and the third amount. It is represented by the sum (= Qf1 + Qf2 + Qf3) with the fuel amount Qf3 of the fuel layer F3. The fuel injection amount Qfa of the layered liquid 200 increases as the engine load increases, and decreases as the engine load decreases.
 また、層状液体200における注水層間の燃料量(本実施形態1では第1注水層W1と第2注水層W2との間に挟まれた第2燃料層F2の燃料量Qf2)は、下流側注水系統50および上流側注水系統60の各注水開始タイミングの制御によって調整される。この際、注水層間の燃料量(=Qf2)は、エンジン負荷に応じた燃料噴射量Qfaに対して一定の割合となるように調整されることが好ましい。 The fuel amount between the water injection layers in the layered liquid 200 (the fuel amount Qf2 of the second fuel layer F2 sandwiched between the first water injection layer W1 and the second water injection layer W2 in the first embodiment) is the downstream water injection. It adjusts by control of each water injection start timing of the system 50 and the upstream side water injection system 60. At this time, it is preferable that the fuel amount (= Qf2) between the water injection layers is adjusted to be a constant ratio with respect to the fuel injection amount Qfa corresponding to the engine load.
 一方、燃焼室17に対する1回の燃料噴射における水噴射量、すなわち、層状液体200の水噴射量Qwaは、第1注水層W1の注水量Qw1と第2注水層W2の注水量Qw2との和(=Qw1+Qw2)によって表される。この層状液体200の水噴射量Qwaは、NOxの低減および燃費の向上を達成するように、エンジン負荷に応じて必要量に調整される。このとき、第1注水層W1の注水量Qw1と第2注水層W2の注水量Qw2との比、すなわち、下流側注水系統50による注水量と上流側注水系統60による注水量との比は、一定であることが好ましい。 On the other hand, the water injection amount in one fuel injection to the combustion chamber 17, that is, the water injection amount Qwa of the stratified liquid 200 is the sum of the water injection amount Qw1 of the first water injection layer W1 and the water injection amount Qw2 of the second water injection layer W2. (= Qw1 + Qw2). The water injection amount Qwa of the layered liquid 200 is adjusted to a required amount according to the engine load so as to achieve a reduction in NOx and an improvement in fuel consumption. At this time, the ratio of the water injection amount Qw1 of the first water injection layer W1 and the water injection amount Qw2 of the second water injection layer W2, that is, the ratio of the water injection amount by the downstream side water injection system 50 and the water injection amount by the upstream side water injection system 60 is Preferably it is constant.
 つぎに、本発明の実施形態1における注水層間の燃料量を調整するための注水タイミングの制御について説明する。図4は、本発明の実施形態1における注水タイミングの制御を説明するための図である。図4において、弁制御信号S1は、燃料流通経路の第1注水位置P1(図2参照)に水を注入する第1注水ポンプ51の制御弁55に対して開閉駆動を指示するための制御信号である。弁制御信号S2は、燃料流通経路の第2注水位置P2(図2参照)に水を注入する第2注水ポンプ61の制御弁65に対して開閉駆動を指示するための制御信号である。図5は、本発明の実施形態1における注水層間の燃料量の調整を説明するための図である。図5において、燃料柱201は、本実施形態1における燃料流通経路内に残存する柱状の燃料である。 Next, control of water injection timing for adjusting the fuel amount between water injection layers in Embodiment 1 of the present invention will be described. FIG. 4 is a diagram for explaining control of water injection timing in the first embodiment of the present invention. In FIG. 4, the valve control signal S1 is a control signal for instructing the control valve 55 of the first water injection pump 51 that injects water into the first water injection position P1 (see FIG. 2) of the fuel flow path to open and close. It is. The valve control signal S2 is a control signal for instructing the control valve 65 of the second water injection pump 61 that injects water into the second water injection position P2 (see FIG. 2) of the fuel flow path to open and close. FIG. 5 is a diagram for explaining the adjustment of the fuel amount between the water injection layers in the first embodiment of the present invention. In FIG. 5, a fuel column 201 is a columnar fuel remaining in the fuel flow path in the first embodiment.
 本実施形態1において、制御部92は、例えば図4に示す弁制御信号S1、S2を制御弁55、65に各々送信して、制御弁55、65の各開閉駆動のタイミングを制御する。これにより、制御部92は、下流側注水系統50の注水期間と上流側注水系統60の注水期間との少なくとも一部が重なるように、下流側注水系統50の注水タイミング(1層目注水タイミング)と上流側注水系統60の注水タイミング(2層目注水タイミング)とをエンジン負荷に応じて制御する。この際、制御部92は、好ましい例として、下流側注水系統50によって注入された水の層と上流側注水系統60によって注入された水の層との間の燃料量がエンジン負荷に応じた燃料噴射量Qfaに対して一定の割合となるように、下流側注水系統50および上流側注水系統60の各注水開始タイミングを制御する。 In the first embodiment, the control unit 92 transmits, for example, valve control signals S1 and S2 shown in FIG. 4 to the control valves 55 and 65, respectively, to control the timing of opening and closing of the control valves 55 and 65. Thereby, the control part 92 water injection timing (1st layer water injection timing) of the downstream water injection system 50 so that at least one part of the water injection period of the downstream water injection system 50 and the water injection period of the upstream water injection system 60 may overlap. And the water injection timing (second layer water injection timing) of the upstream water injection system 60 are controlled according to the engine load. At this time, as a preferable example, the control unit 92 determines that the amount of fuel between the layer of water injected by the downstream side water injection system 50 and the layer of water injected by the upstream side water injection system 60 corresponds to the engine load. Each water injection start timing of the downstream side water injection system 50 and the upstream side water injection system 60 is controlled so as to be a constant ratio with respect to the injection amount Qfa.
 詳細には、制御部92は、エンジン負荷に応じて、注水の待機時間ΔTを算出する。待機時間ΔTは、下流側注水系統50および上流側注水系統60のうち、先に注水を開始した注水系統の注水ピストンの作動開始時からその後に注水を開始する注水系統の注水ピストンの作動開始時までの時間である。この待機時間ΔTは、例えば、船舶の航行状況に応じて舶用ディーゼルエンジン10に要求されるエンジン負荷時のエンジン回転数(単位時間当りのエンジン回転数)と燃料噴射量(燃料の1回当りの噴射量)と注水量(噴射1回分の燃料中に注入する水量)とを各々独立変数x、y、zとして含む関数f(x,y,z)によって次式(1)のように表される。例えば、制御部92は、エンジン負荷の増加に伴い待機時間ΔTが増加し、エンジン負荷の減少に伴い待機時間ΔTが減少するように、待機時間ΔTを算出する。
 
待機時間ΔT=f(x,y,z)   ・・・(1)
 
なお、これらのエンジン回転数、燃料噴射量および注水量は、舶用ディーゼルエンジン10のシミュレーションや実験等の結果に基づいて導出することができる。制御部92には、この式(1)が予め設定されている。
Specifically, the control unit 92 calculates the water injection standby time ΔT according to the engine load. The waiting time ΔT is the time when the operation of the water injection piston of the water injection system that starts water injection from the time of starting the operation of the water injection piston of the water injection system of the downstream side water injection system 50 and the upstream side water injection system 60 that started water injection first. It is time until. The waiting time ΔT is, for example, the engine speed at the time of engine load (engine speed per unit time) required for the marine diesel engine 10 according to the navigation status of the ship and the fuel injection amount (per fuel time). The following equation (1) is expressed by a function f (x, y, z) including the injection amount) and the water injection amount (the amount of water injected into the fuel for one injection) as independent variables x, y, z. The For example, the control unit 92 calculates the standby time ΔT so that the standby time ΔT increases as the engine load increases and the standby time ΔT decreases as the engine load decreases.

Standby time ΔT = f (x, y, z) (1)

The engine speed, the fuel injection amount, and the water injection amount can be derived based on the results of simulation, experiment, etc. of the marine diesel engine 10. This equation (1) is preset in the control unit 92.
 制御部92は、上記の待機時間ΔTとして、例えば、下流側注水系統50の待機時間ΔT1を算出する。下流側注水系統50の待機時間ΔT1は、上流側注水系統60が注水を開始してから下流側注水系統50が注水を開始するまでの時間、すなわち、第2注水ポンプ61が作動を開始してから第1注水ポンプ51が作動を開始するまでの時間である。制御部92は、この算出した待機時間ΔT1分、下流側注水系統50の注水開始タイミングを上流側注水系統60の注水開始タイミングよりも遅らせる。 The control unit 92 calculates, for example, the standby time ΔT1 of the downstream water injection system 50 as the standby time ΔT. The waiting time ΔT1 of the downstream side water injection system 50 is a time from when the upstream side water injection system 60 starts water injection to when the downstream side water injection system 50 starts water injection, that is, when the second water injection pump 61 starts operating. Until the first water injection pump 51 starts operating. The control unit 92 delays the water injection start timing of the downstream side water injection system 50 from the water injection start timing of the upstream side water injection system 60 by the calculated waiting time ΔT1.
 具体的には、制御部92は、検出部91から受信した電気信号に示されるクランク角度を、検出部91によって検出されたクランク角度(以下、クランク角度検出値と適宜いう)として取得する。制御部92は、図4に示すように、クランク角度検出値がクランク角度R1となったタイミングT1に上流側注水系統60の制御弁65に対して開駆動を指示する。これにより、制御部92は、上流側注水系統60の第2注水ポンプ61を作動開始させる。この制御に基づいて、第2注水ポンプ61は、燃料流通経路の第2注水位置P2への注水を開始する。すなわち、クランク角度R1のタイミングT1は、上流側注水系統60の注水開始タイミングである。このタイミングT1では、図5に示すように、燃料流通経路内の燃料柱201のうち第2注水位置P2への水202の注入が開始されている。 Specifically, the control unit 92 acquires the crank angle indicated by the electrical signal received from the detection unit 91 as the crank angle detected by the detection unit 91 (hereinafter referred to as a crank angle detection value as appropriate). As shown in FIG. 4, the control unit 92 instructs the control valve 65 of the upstream water injection system 60 to open at timing T1 when the detected crank angle value becomes the crank angle R1. Thereby, the control part 92 starts the operation | movement of the 2nd water injection pump 61 of the upstream water injection system 60. FIG. Based on this control, the second water injection pump 61 starts water injection to the second water injection position P2 of the fuel flow path. That is, the timing T1 of the crank angle R1 is the water injection start timing of the upstream water injection system 60. At this timing T1, as shown in FIG. 5, the injection of water 202 into the second water injection position P2 in the fuel column 201 in the fuel flow path is started.
 なお、前回の燃料噴射完了後から上記注水開始タイミング(タイミングT1)までの期間内のタイミングT0では、図5に示すように、燃料柱201に対する注水は開始されていない。このときの燃料柱201の燃料量は、上述した燃料噴射量Qfaに相当する。 Note that, as shown in FIG. 5, water injection to the fuel column 201 is not started at the timing T0 within the period from the completion of the previous fuel injection to the water injection start timing (timing T1). The fuel amount of the fuel column 201 at this time corresponds to the fuel injection amount Qfa described above.
 ついで、制御部92は、上述したように算出した待機時間ΔT1分、上流側注水系統60の注水開始タイミングから遅らせたタイミングに、下流側注水系統50による注水を開始させる。具体的には、制御部92は、下流側注水系統50の待機時間ΔT1を、エンジン負荷に応じたエンジン回転数とエンジン回転の経過時間とをもとにクランク角度の変化量ΔRに変換する。制御部92は、得られたクランク角度の変化量ΔRと、上流側注水系統60の注水開始タイミング(タイミングT1)時のクランク角度R1とを加算して、クランク角度R2を算出する。制御部92は、図4に示すように、クランク角度検出値がクランク角度R2となったタイミングT2に下流側注水系統50の制御弁55に対して開駆動を指示する。これにより、制御部92は、上流側注水系統60の第2注水ポンプ61の作動を継続させながら、下流側注水系統50の第1注水ポンプ51を作動開始させる。この制御に基づいて、第1注水ポンプ51は、燃料流通経路の第1注水位置P1への注水を開始する。すなわち、クランク角度R2のタイミングT2は、下流側注水系統50の注水開始タイミングである。一方、第2注水ポンプ61は、燃料流通経路の第2注水位置P2への注水を継続して行っている。このタイミングT2では、図5に示すように、燃料流通経路内の燃料柱201のうち、第2注水位置P2への水202の注入が継続して行われながら、第1注水位置P1への水203の注入が開始されている。 Next, the control unit 92 starts the water injection by the downstream side water injection system 50 at a timing delayed from the water injection start timing of the upstream side water injection system 60 by the waiting time ΔT1 calculated as described above. Specifically, the control unit 92 converts the waiting time ΔT1 of the downstream water injection system 50 into a crank angle change amount ΔR based on the engine speed corresponding to the engine load and the elapsed time of the engine rotation. The controller 92 calculates the crank angle R2 by adding the obtained change amount ΔR of the crank angle and the crank angle R1 at the water injection start timing (timing T1) of the upstream water injection system 60. As shown in FIG. 4, the control unit 92 instructs the control valve 55 of the downstream water injection system 50 to open at timing T <b> 2 when the detected crank angle value becomes the crank angle R <b> 2. Thereby, the control part 92 starts operation | movement of the 1st water injection pump 51 of the downstream water injection system 50, continuing operation | movement of the 2nd water injection pump 61 of the upstream water injection system 60. FIG. Based on this control, the first water injection pump 51 starts water injection to the first water injection position P1 of the fuel flow path. That is, the timing T2 of the crank angle R2 is the water injection start timing of the downstream side water injection system 50. On the other hand, the second water injection pump 61 continuously performs water injection to the second water injection position P2 of the fuel flow path. At this timing T2, as shown in FIG. 5, water 202 is continuously injected into the second water injection position P2 in the fuel column 201 in the fuel flow path, and the water is supplied to the first water injection position P1. 203 injection has started.
 その後、第2注水ポンプ61は、制御弁65が閉駆動するまでの期間、燃料流通経路の第2注水位置P2への注水を継続して行う。これに並行して、第1注水ポンプ51は、制御弁55が閉駆動するまでの期間、燃料流通経路の第1注水位置P1への注水を継続して行う。 Thereafter, the second water injection pump 61 continues to inject water into the second water injection position P2 of the fuel flow path until the control valve 65 is driven to close. In parallel with this, the first water injection pump 51 continuously performs water injection to the first water injection position P1 of the fuel flow path until the control valve 55 is driven to close.
 例えば、図4、5に示すように、クランク角度R2からクランク角度R3(>R2)までの時間ΔT2の期間では、第2注水位置P2の水202の注入が進むとともに、第1注水位置P1の水203の注入が進む。この第1注水位置P1の水203の注入に伴い、第1注水位置P1と第2注水位置P2との間の燃料は、第2注水位置P2の水202を越えて流通方向上流側に押し戻される。これにより、第1注水位置P1と第2注水位置P2との間の燃料量は、減少するように調整される。 For example, as shown in FIGS. 4 and 5, in the period of time ΔT2 from the crank angle R2 to the crank angle R3 (> R2), the injection of the water 202 at the second water injection position P2 proceeds, and at the first water injection position P1. Injection of water 203 proceeds. With the injection of the water 203 at the first water injection position P1, the fuel between the first water injection position P1 and the second water injection position P2 is pushed back upstream of the water 202 at the second water injection position P2 in the flow direction. . Thereby, the fuel amount between the 1st water injection position P1 and the 2nd water injection position P2 is adjusted so that it may reduce.
 続いて、クランク角度R3のタイミングT3では、第2注水位置P2の水202が、燃料柱201の幅方向(燃料流通経路の幅方向)全域に広がるまで注入されている。この際、第2注水位置P2の水202は、図5に示すように、燃料柱201を、第2注水位置P2よりも下流側に位置する下流側燃料201aと、第2注水位置P2よりも上流側に位置する最上流燃料201bとに分ける。この段階において、第1注水位置P1と第2注水位置P2との間の燃料は、第1注水位置P1の水203の注入が進行しても、第2注水位置P2の水202を越えて流通方向上流側に押し戻されることが無くなる。これにより、第1注水位置P1と第2注水位置P2との間の燃料量の調整が終了し、下流側燃料201aの燃料量が決まる。 Subsequently, at the timing T3 of the crank angle R3, the water 202 at the second water injection position P2 is injected until it spreads over the entire width direction of the fuel column 201 (width direction of the fuel flow path). At this time, as shown in FIG. 5, the water 202 at the second water injection position P2 moves the fuel column 201 downstream of the second water injection position P2 and the downstream fuel 201a and the second water injection position P2. It is divided into the most upstream fuel 201b located on the upstream side. At this stage, the fuel between the first water injection position P1 and the second water injection position P2 circulates over the water 202 at the second water injection position P2 even if the injection of the water 203 at the first water injection position P1 proceeds. No longer being pushed back in the direction upstream. Thereby, the adjustment of the fuel amount between the first water injection position P1 and the second water injection position P2 is completed, and the fuel amount of the downstream fuel 201a is determined.
 その後、制御部92は、図4に示すように、クランク角度検出値がクランク角度R4となったタイミングT4に上流側注水系統60の制御弁65に対して閉駆動を指示する。これにより、制御部92は、下流側注水系統50の第1注水ポンプ51の作動を継続させながら、上流側注水系統60の第2注水ポンプ61を作動停止させる。この制御に基づいて、第2注水ポンプ61は、燃料流通経路の第2注水位置P2への注水を終了する。すなわち、クランク角度R4のタイミングT4は、上流側注水系統60の注水終了タイミングである。一方、第1注水ポンプ51は、燃料流通経路の第1注水位置P1への注水を継続して行っている。 Thereafter, as shown in FIG. 4, the control unit 92 instructs the control valve 65 of the upstream water injection system 60 to be closed at a timing T4 when the crank angle detection value becomes the crank angle R4. Accordingly, the control unit 92 stops the operation of the second water injection pump 61 of the upstream side water injection system 60 while continuing the operation of the first water injection pump 51 of the downstream side water injection system 50. Based on this control, the second water injection pump 61 ends water injection to the second water injection position P2 of the fuel flow path. That is, the timing T4 of the crank angle R4 is the water injection end timing of the upstream water injection system 60. On the other hand, the first water injection pump 51 continuously performs water injection to the first water injection position P1 of the fuel flow path.
 例えば、図4、5に示すように、クランク角度R3からクランク角度R4(>R3)までの時間ΔT3の期間では、第2注水位置P2の水202が燃料柱201の幅方向全域に広がった状態から更に注入されるとともに、第1注水位置P1の水203が継続して注入されている。この段階において、第1注水位置P1の水203の注入は、下流側燃料201aとともに第2注水位置P2の水202を流通方向上流側へ押しながら行われる。 For example, as shown in FIGS. 4 and 5, in the period of time ΔT3 from the crank angle R3 to the crank angle R4 (> R3), the water 202 at the second water injection position P2 spreads over the entire width direction of the fuel column 201. The water 203 at the first water injection position P1 is continuously injected. In this stage, the injection of the water 203 at the first water injection position P1 is performed while pushing the water 202 at the second water injection position P2 together with the downstream fuel 201a to the upstream side in the flow direction.
 また、図5に示すように、クランク角度R4のタイミングT4では、第2注水位置P2の水202が必要量注入された状態となっている。一方、第1注水位置P1の水203は、燃料柱201の幅方向全域に広がるまで注入された状態となっている。この状態の水203は、燃料柱201の下流側燃料201aを、第1注水位置P1よりも下流側に位置する最下流燃料201cと、第2注水位置P2の水202と第1注水位置P1の水203とに挟まれる注水層間燃料201dとに分ける。これにより、注水層間燃料201dの燃料量、すなわち注水層間の燃料量(=Qf2)と、最下流燃料201cの燃料量とが決まる。なお、第1注水位置P1の水203が燃料柱201の幅方向全域に広がるまで注入されるタイミングは、第2注水位置P2の水202が必要量注入されたタイミングT4と同じであってもよいし、前のタイミングであってもよいし、後のタイミングであってもよい。 Further, as shown in FIG. 5, at the timing T4 of the crank angle R4, a necessary amount of water 202 at the second water injection position P2 is injected. On the other hand, the water 203 at the first water injection position P <b> 1 is in a state of being injected until it spreads over the entire width direction of the fuel column 201. In this state, the water 203 is obtained by changing the downstream fuel 201a of the fuel column 201 between the most downstream fuel 201c located downstream of the first water injection position P1, the water 202 at the second water injection position P2, and the first water injection position P1. It is divided into a water injection interlayer fuel 201 d sandwiched between water 203. Thereby, the fuel amount of the water injection layer fuel 201d, that is, the fuel amount (= Qf2) between the water injection layers and the fuel amount of the most downstream fuel 201c are determined. Note that the timing at which the water 203 at the first water injection position P1 is injected until it spreads over the entire width direction of the fuel column 201 may be the same as the timing T4 at which the required amount of water 202 at the second water injection position P2 is injected. It may be the previous timing or the later timing.
 その後、制御部92は、図4に示すように、クランク角度検出値がクランク角度R5となったタイミングT5に下流側注水系統50の制御弁55に対して閉駆動を指示する。これにより、制御部92は、下流側注水系統50の第1注水ポンプ51を作動停止させる。この制御に基づいて、第1注水ポンプ51は、燃料流通経路の第1注水位置P1への注水を終了する。すなわち、クランク角度R5のタイミングT5は、下流側注水系統50の注水終了タイミングである。 Thereafter, as shown in FIG. 4, the control unit 92 instructs the control valve 55 of the downstream water injection system 50 to be closed at timing T5 when the crank angle detection value becomes the crank angle R5. Thereby, the control part 92 stops operation | movement of the 1st water injection pump 51 of the downstream water injection system 50. FIG. Based on this control, the first water injection pump 51 ends water injection to the first water injection position P1 of the fuel flow path. That is, the timing T5 of the crank angle R5 is the water injection end timing of the downstream water injection system 50.
 例えば、図5に示すように、クランク角度R4のタイミングT4からクランク角度R5(>R4)のタイミングT5までの期間では、第1注水位置P1の水203が、燃料柱201の幅方向全域に広がった状態から更に注入されている。一方、第2注水位置P2の水202の注入は、上述したタイミングT4で既に終了している。この段階において、第1注水位置P1の水203の注入は、上述したタイミングT3からタイミングT4までの期間と同様に行われ、水203の注入量が必要量になるまで継続される。そして、クランク角度R5のタイミングT5では、第1注水位置P1および第2注水位置P2の各注水が終了する。この結果、第1燃料層F1と第1注水層W1と第2燃料層F2と第2注水層W2と第3燃料層F3とからなる層状液体200が、燃料流通経路内に形成される。 For example, as shown in FIG. 5, during the period from the timing T4 of the crank angle R4 to the timing T5 of the crank angle R5 (> R4), the water 203 at the first water injection position P1 spreads over the entire width direction of the fuel column 201. It is further injected from the state. On the other hand, the injection of the water 202 at the second water injection position P2 has already ended at the timing T4 described above. In this stage, the injection of the water 203 at the first water injection position P1 is performed in the same manner as the period from the timing T3 to the timing T4 described above, and is continued until the injection amount of the water 203 becomes a necessary amount. And in timing T5 of crank angle R5, each water injection of the 1st water injection position P1 and the 2nd water injection position P2 is completed. As a result, a stratified liquid 200 composed of the first fuel layer F1, the first water injection layer W1, the second fuel layer F2, the second water injection layer W2, and the third fuel layer F3 is formed in the fuel flow path.
 ここで、本実施形態1において、上流側注水系統60の注水期間は、クランク角度R1のタイミングT1からクランク角度R4のタイミングT4までの期間である。すなわち、上流側注水系統60の注水期間は、図4に示す待機時間ΔT1と時間ΔT2と時間ΔT3とを加算した時間分の期間である。この注水期間は、図5に示す第2注水位置P2に必要量の水202を注入する際に掛かる時間によって決まる。すなわち、上流側注水系統60の注水終了タイミング(タイミングT4)に対応するクランク角度R4は、注水開始タイミングに対応するクランク角度R1と、上記必要量の水202の注入に要する時間とをもとに導出される。 Here, in the first embodiment, the water injection period of the upstream water injection system 60 is a period from the timing T1 of the crank angle R1 to the timing T4 of the crank angle R4. That is, the water injection period of the upstream water injection system 60 is a period corresponding to the time obtained by adding the waiting time ΔT1, the time ΔT2, and the time ΔT3 shown in FIG. This water injection period is determined by the time it takes to inject the required amount of water 202 into the second water injection position P2 shown in FIG. That is, the crank angle R4 corresponding to the water injection end timing (timing T4) of the upstream water injection system 60 is based on the crank angle R1 corresponding to the water injection start timing and the time required for injecting the required amount of water 202. Derived.
 また、下流側注水系統50の注水期間は、クランク角度R2のタイミングT2からクランク角度R5のタイミングT5までの期間である。この注水期間は、図5に示す第1注水位置P1に必要量の水203を注入する際に掛かる時間によって決まる。すなわち、下流側注水系統50の注水終了タイミング(タイミングT5)に対応するクランク角度R5は、注水開始タイミングに対応するクランク角度R2と、上記必要量の水203の注入に要する時間とをもとに導出される。 Further, the water injection period of the downstream water injection system 50 is a period from the timing T2 of the crank angle R2 to the timing T5 of the crank angle R5. This water injection period is determined by the time taken to inject a required amount of water 203 into the first water injection position P1 shown in FIG. That is, the crank angle R5 corresponding to the water injection end timing (timing T5) of the downstream side water injection system 50 is based on the crank angle R2 corresponding to the water injection start timing and the time required to inject the required amount of water 203. Derived.
 本実施形態1において、上流側注水系統60の注水期間と下流側注水系統50の注水期間との重なる期間は、図4に示すように、クランク角度R2からクランク角度R4までの時間ΔT4に相当する。この時間ΔT4は、下流側注水系統50の注水によって注水層間の燃料量が減少するよう調整(減量調整)される時間ΔT2と、注水層間の燃料量の調整が終了してから上流側注水系統60の注水が終了するまでの時間ΔT3とを加算した時間である。下流側注水系統50の注水開始タイミングは、エンジン負荷の増加に伴って時間ΔT2が減少し、エンジン負荷の減少に伴って時間ΔT2が増加するように、上流側注水系統60の注水開始タイミングから待機時間ΔT1だけ遅れるタイミングに制御される。すなわち、この待機時間ΔT1は、エンジン負荷の増加に伴って増加し、エンジン負荷の減少に伴って減少する。なお、この待機時間ΔT1が零値(ΔT1=0)である場合、下流側注水系統50の注水開始タイミングは、上流側注水系統60の注水開始タイミングと同時のタイミングに制御される。 In the first embodiment, the overlapping period of the water injection period of the upstream water injection system 60 and the water injection period of the downstream water injection system 50 corresponds to the time ΔT4 from the crank angle R2 to the crank angle R4 as shown in FIG. . This time ΔT4 is adjusted (decrease adjustment) so that the amount of fuel between the water injection layers is reduced by the water injection of the downstream water injection system 50, and after the adjustment of the fuel amount between the water injection layers is completed, the upstream water injection system 60 This is a time obtained by adding the time ΔT3 until the water injection is completed. The water injection start timing of the downstream water injection system 50 is on standby from the water injection start timing of the upstream water injection system 60 so that the time ΔT2 decreases as the engine load increases and the time ΔT2 increases as the engine load decreases. The timing is controlled to be delayed by time ΔT1. That is, the waiting time ΔT1 increases with an increase in engine load, and decreases with a decrease in engine load. When the waiting time ΔT1 is a zero value (ΔT1 = 0), the water injection start timing of the downstream side water injection system 50 is controlled to the same timing as the water injection start timing of the upstream side water injection system 60.
 図6は、本発明の実施形態1における層状液体のエンジン負荷に応じた噴射量の一例を示す図である。図6に示す噴射量は、1つの燃料噴射弁30からシリンダ12内の燃焼室17に噴射される層状液体200(図3参照)の1回当りの噴射量である。この層状液体200の噴射量は、エンジン負荷に応じた燃料噴射量Qfaと第1注水層W1および第2注水層W2の各注水量Qw1、Qw2との和(=Qfa+Qw1+Qw2)によって表される。 FIG. 6 is a diagram illustrating an example of an injection amount corresponding to the engine load of the stratified liquid according to the first embodiment of the present invention. The injection amount shown in FIG. 6 is an injection amount per time of the stratified liquid 200 (see FIG. 3) injected from one fuel injection valve 30 into the combustion chamber 17 in the cylinder 12. The injection amount of the layered liquid 200 is represented by the sum (= Qfa + Qw1 + Qw2) of the fuel injection amount Qfa corresponding to the engine load and the water injection amounts Qw1, Qw2 of the first water injection layer W1 and the second water injection layer W2.
 本実施形態1において、層状液体200の噴射量は、上述した下流側注水系統50および上流側注水系統60の各注水開始タイミングの制御によって設定される。例えば、図6に示すように、層状液体200の噴射量は、エンジン負荷の増加に伴って増加し、エンジン負荷の減少に伴って減少する。このような層状液体200のうち、第1注水層W1と第2注水層W2との間に挟まれた第2燃料層F2の燃料量(すなわち注水層間の燃料量)は、エンジン負荷に応じて適切な量に調整される。好ましくは、注水層間に燃料層を有する層状液体200が燃料流通経路内に形成されるエンジン負荷の範囲(図6では55%以上100%以下)において、この注水層間の燃料量は、エンジン負荷に応じて増減する燃料噴射量Qfaに対して一定の割合となるように調整(最適化)される。さらには、層状液体200において、第1注水層W1の注水量Qw1と第2注水層W2との注水量Qw2との比は一定である。 In the first embodiment, the injection amount of the layered liquid 200 is set by controlling the water injection start timings of the downstream water injection system 50 and the upstream water injection system 60 described above. For example, as shown in FIG. 6, the injection amount of the layered liquid 200 increases as the engine load increases, and decreases as the engine load decreases. In such a layered liquid 200, the fuel amount of the second fuel layer F2 sandwiched between the first water injection layer W1 and the second water injection layer W2 (that is, the fuel amount between the water injection layers) depends on the engine load. Adjust to the appropriate amount. Preferably, in the engine load range (55% or more and 100% or less in FIG. 6) in which the layered liquid 200 having the fuel layer between the water injection layers is formed in the fuel flow path, the amount of fuel between the water injection layers is equal to the engine load. The fuel injection amount Qfa that increases or decreases accordingly is adjusted (optimized) to be a constant ratio. Furthermore, in the layered liquid 200, the ratio of the water injection amount Qw1 of the first water injection layer W1 and the water injection amount Qw2 of the second water injection layer W2 is constant.
 以上、説明したように、本発明の実施形態1に係る燃料噴射装置100では、舶用ディーゼルエンジン10のシリンダ12内の燃焼室17に燃料および水を層状に噴射する燃料噴射弁30と、配管を通じて燃料噴射弁30に燃料を圧送する燃料噴射ポンプ41と、燃料噴射ポンプ41から燃料噴射弁30の噴射口31に至る燃料流通経路の第1注水位置P1に水を注入する下流側注水系統50と、この燃料流通経路のうち下流側注水系統50よりも燃料の流通方向上流側の第2注水位置P2に水を注入する上流側注水系統60とを設け、下流側注水系統50の注水期間と上流側注水系統60の注水期間との少なくとも一部が重なるように、下流側注水系統50および上流側注水系統60の各注水開始タイミングをエンジン負荷に応じて制御している。この際、上流側注水系統60が注水を開始してから下流側注水系統50が注水を開始するまでの下流側注水系統50の待機時間ΔT1をエンジン負荷に応じて算出し、算出した待機時間ΔT1分、下流側注水系統50の注水開始タイミングを上流側注水系統60の注水開始タイミングよりも遅らせている。 As described above, in the fuel injection device 100 according to Embodiment 1 of the present invention, the fuel injection valve 30 that injects fuel and water into the combustion chamber 17 in the cylinder 12 of the marine diesel engine 10 in a layered manner, and through the piping. A fuel injection pump 41 that pumps fuel to the fuel injection valve 30; a downstream water injection system 50 that injects water into the first water injection position P1 of the fuel flow path from the fuel injection pump 41 to the injection port 31 of the fuel injection valve 30; An upstream water injection system 60 for injecting water into the second water injection position P2 upstream of the downstream water injection system 50 in the fuel distribution direction in the fuel distribution path is provided, and the water injection period and upstream of the downstream water injection system 50 are provided. Control of the water injection start timings of the downstream water injection system 50 and the upstream water injection system 60 according to the engine load so that at least a part of the water injection period of the side water injection system 60 overlaps. To have. At this time, the standby time ΔT1 of the downstream water injection system 50 from when the upstream water injection system 60 starts water injection to when the downstream water injection system 50 starts water injection is calculated according to the engine load, and the calculated standby time ΔT1 Minutes, the water injection start timing of the downstream water injection system 50 is delayed from the water injection start timing of the upstream water injection system 60.
 上記の構成により、下流側注水系統50の注水期間と上流側注水系統60の注水期間との重なる期間内に、下流側注水系統50による注水層と上流側注水系統60による注水層との間の燃料量(注水層間の燃料量)を、エンジン負荷に応じた燃料噴射量Qfaに対する当該注水層間の燃料量の割合が過大または過小とならないように調整することができる。このため、燃料噴射弁30から燃料および水を層状に噴射する際、エンジン負荷に応じて注水層間の燃料量を適切に調整することができる。この結果、排ガス中のNOxを低減させるべく燃料および水を層状に噴射する際に起こり得る舶用ディーゼルエンジン10の燃焼不良等の望ましくない燃焼状態の発生を抑制することができる。 With the above configuration, the water injection layer formed by the downstream side water injection system 50 and the water injection layer formed by the upstream side water injection system 60 are overlapped with each other within the overlapping period of the water injection period of the downstream side water injection system 50 and the water injection period of the upstream side water injection system 60. The amount of fuel (the amount of fuel between the water injection layers) can be adjusted so that the ratio of the amount of fuel between the water injection layers relative to the fuel injection amount Qfa according to the engine load does not become excessive or small. For this reason, when fuel and water are injected in layers from the fuel injection valve 30, the amount of fuel between the water injection layers can be appropriately adjusted according to the engine load. As a result, it is possible to suppress the occurrence of an undesirable combustion state such as poor combustion of the marine diesel engine 10 that may occur when fuel and water are injected in layers to reduce NOx in the exhaust gas.
 また、本発明の実施形態1に係る燃料噴射装置100では、上述した注水層間の燃料量がエンジン負荷に応じた燃料噴射量Qfaに対して一定の割合とすべく、下流側注水系統50および上流側注水系統60の各注水開始タイミングをエンジン負荷に応じて制御している。このため、燃料噴射弁30から燃料および水を層状に噴射する際、注水層間の燃料量をエンジン負荷毎の最適な燃料量に調整することができる。この結果、排ガス中のNOxを最も効果的に低減させることができる。 Further, in the fuel injection device 100 according to Embodiment 1 of the present invention, the downstream water injection system 50 and the upstream are arranged so that the fuel amount between the water injection layers described above is a constant ratio with respect to the fuel injection amount Qfa corresponding to the engine load. Each water injection start timing of the side water injection system 60 is controlled according to the engine load. For this reason, when fuel and water are injected in layers from the fuel injection valve 30, the fuel amount between the water injection layers can be adjusted to the optimum fuel amount for each engine load. As a result, NOx in the exhaust gas can be reduced most effectively.
 また、本発明の実施形態1に係る燃料噴射装置100では、下流側注水系統50による注水量Qw1と上流側注水系統60による注水量Qw2との比を一定にしている。このため、燃料噴射弁30から燃料および水を層状に噴射する際、燃料層に後続して噴射される注水層の水量をエンジン負荷毎に最適化することができる。この結果、燃料の燃焼後の水噴射による失火を防止して舶用ディーゼルエンジン10の安定した作動を確保するとともに、排ガス中のNOxを最も効果的に低減させることができる。 Further, in the fuel injection device 100 according to Embodiment 1 of the present invention, the ratio between the water injection amount Qw1 by the downstream water injection system 50 and the water injection amount Qw2 by the upstream water injection system 60 is made constant. For this reason, when fuel and water are injected in layers from the fuel injection valve 30, the amount of water in the water injection layer injected following the fuel layer can be optimized for each engine load. As a result, misfire caused by water injection after fuel combustion can be prevented to ensure stable operation of the marine diesel engine 10, and NOx in the exhaust gas can be most effectively reduced.
(実施形態2)
 つぎに、本発明の実施形態2について説明する。上述した実施形態1では、エンジン負荷に応じて算出した待機時間分、下流側注水系統50の注水開始タイミングを上流側注水系統60の注水開始タイミングよりも遅らせるように、下流側注水系統50および上流側注水系統60の各注水開始タイミングを制御していたが、本実施形態2では、エンジン負荷に応じて算出した待機時間分、上流側注水系統60の注水開始タイミングを下流側注水系統50の注水開始タイミングよりも遅らせるように、下流側注水系統50および上流側注水系統60の各注水開始タイミングを制御している。
(Embodiment 2)
Next, Embodiment 2 of the present invention will be described. In the first embodiment described above, the downstream side water injection system 50 and the upstream side are set so as to delay the water injection start timing of the downstream side water injection system 50 from the water injection start timing of the upstream side water injection system 60 by the standby time calculated according to the engine load. Although each water injection start timing of the side water injection system 60 is controlled, in the second embodiment, the water injection start timing of the upstream water injection system 60 is set to the water injection start time of the upstream water injection system 50 for the standby time calculated according to the engine load. Each water injection start timing of the downstream side water injection system 50 and the upstream side water injection system 60 is controlled so as to be delayed from the start timing.
 図7は、本発明の実施形態2に係る燃料噴射装置の一構成例を示す模式図である。図7に示すように、この燃料噴射装置110は、上述した実施形態1に係る燃料噴射装置100の制御部92に代えて制御部112を備える。その他の構成は実施形態1と同じであり、同一構成部分には同一符号を付している。また、特に図示しないが、本実施形態2に係る燃料噴射装置110が適用された舶用ディーゼルエンジンは、上記の制御部112を備える構成以外、上述した実施形態1における舶用ディーゼルエンジン10と同様に構成される。 FIG. 7 is a schematic diagram showing a configuration example of a fuel injection device according to Embodiment 2 of the present invention. As shown in FIG. 7, the fuel injection device 110 includes a control unit 112 instead of the control unit 92 of the fuel injection device 100 according to Embodiment 1 described above. Other configurations are the same as those of the first embodiment, and the same components are denoted by the same reference numerals. Although not particularly illustrated, the marine diesel engine to which the fuel injection device 110 according to the second embodiment is applied has the same configuration as the marine diesel engine 10 in the first embodiment described above, except for the configuration including the control unit 112 described above. Is done.
 制御部112は、各種プログラムを実行するためのCPU、メモリおよびシーケンサ等によって構成される。制御部112は、上述した燃料および水の層状噴射タイミング以外の期間において、燃料で満たされた状態にある燃料流通経路の第1注水位置P1および第2注水位置P2に水を各々注入するように、下流側注水系統50の注水タイミングおよび上流側注水系統60の注水タイミングをエンジン負荷に応じて制御する。この際、制御部112は、下流側注水系統50の注水期間と上流側注水系統60の注水期間との少なくとも一部が重なるようにすべく、エンジン負荷に応じて算出した待機時間分、上流側注水系統60の注水開始タイミングを下流側注水系統50の注水開始タイミングよりも遅らせるように、下流側注水系統50の第1注水ポンプ51による注水開始タイミングと上流側注水系統60の第2注水ポンプ61による注水開始タイミングと制御する。なお、制御部112は、上述した実施形態1における制御部92と同様に、燃料噴射弁30から燃焼室17への燃料および水の層状噴射タイミングを制御する。 The control unit 112 includes a CPU, a memory, a sequencer, and the like for executing various programs. The control unit 112 injects water into each of the first water injection position P1 and the second water injection position P2 of the fuel flow path in a state other than the above-described fuel and water layered injection timing. The water injection timing of the downstream side water injection system 50 and the water injection timing of the upstream side water injection system 60 are controlled according to the engine load. At this time, the control unit 112 sets the upstream side of the standby time calculated according to the engine load so that at least a part of the water injection period of the downstream water injection system 50 and the water injection period of the upstream water injection system 60 overlap each other. The water injection start timing by the first water injection pump 51 of the downstream side water injection system 50 and the second water injection pump 61 of the upstream side water injection system 60 so that the water injection start timing of the water injection system 60 is delayed from the water injection start timing of the downstream side water injection system 50. Control with the start timing of water injection. In addition, the control part 112 controls the layered injection timing of the fuel and water from the fuel injection valve 30 to the combustion chamber 17 similarly to the control part 92 in Embodiment 1 mentioned above.
 つぎに、本発明の実施形態2における注水層間の燃料量を調整するための注水タイミングの制御について説明する。図8は、本発明の実施形態2における注水タイミングの制御を説明するための図である。図9は、本発明の実施形態2における注水層間の燃料量の調整を説明するための図である。 Next, control of water injection timing for adjusting the amount of fuel between water injection layers in Embodiment 2 of the present invention will be described. FIG. 8 is a diagram for explaining control of water injection timing in the second embodiment of the present invention. FIG. 9 is a diagram for explaining the adjustment of the fuel amount between the water injection layers in the second embodiment of the present invention.
 本実施形態2において、制御部112は、例えば図8に示す弁制御信号S1、S2を制御弁55、65に各々送信して、制御弁55、65の各開閉駆動のタイミングを制御する。これにより、制御部112は、下流側注水系統50の注水期間と上流側注水系統60の注水期間との少なくとも一部が重なるように、下流側注水系統50の注水タイミング(1層目注水タイミング)と上流側注水系統60の注水タイミング(2層目注水タイミング)とをエンジン負荷に応じて制御する。この際、制御部112は、好ましい例として、下流側注水系統50によって注入された水の層と上流側注水系統60によって注入された水の層との間の燃料量がエンジン負荷に応じた燃料噴射量Qfaに対して一定の割合となるように、下流側注水系統50および上流側注水系統60の各注水開始タイミングを制御する。 In the second embodiment, the control unit 112 transmits, for example, valve control signals S1 and S2 shown in FIG. 8 to the control valves 55 and 65, respectively, to control the timing of opening and closing of the control valves 55 and 65. Thereby, the control part 112 water injection timing (1st layer water injection timing) of the downstream water injection system 50 so that at least one part of the water injection period of the downstream water injection system 50 and the water injection period of the upstream water injection system 60 may overlap. And the water injection timing (second layer water injection timing) of the upstream water injection system 60 are controlled according to the engine load. At this time, as a preferable example, the control unit 112 determines the amount of fuel between the water layer injected by the downstream water injection system 50 and the water layer injected by the upstream water injection system 60 according to the engine load. Each water injection start timing of the downstream side water injection system 50 and the upstream side water injection system 60 is controlled so as to be a constant ratio with respect to the injection amount Qfa.
 詳細には、制御部112は、上述した式(1)が予め設定され、式(1)に基づく待機時間ΔTとして、例えば、上流側注水系統60の待機時間ΔT11を算出する。上流側注水系統60の待機時間ΔT11は、下流側注水系統50が注水を開始してから上流側注水系統60が注水を開始するまでの時間、すなわち、第1注水ポンプ51が作動を開始してから第2注水ポンプ61が作動を開始するまでの時間である。制御部112は、この算出した待機時間ΔT11分、上流側注水系統60の注水開始タイミングを下流側注水系統50の注水開始タイミングよりも遅らせる。 In detail, the control unit 112 calculates the standby time ΔT11 of the upstream water injection system 60, for example, as the standby time ΔT based on the formula (1) in which the above-described formula (1) is set in advance. The standby time ΔT11 of the upstream side water injection system 60 is the time from when the downstream side water injection system 50 starts water injection to when the upstream side water injection system 60 starts water injection, that is, when the first water injection pump 51 starts operating. Until the second water injection pump 61 starts operating. The control unit 112 delays the water injection start timing of the upstream water injection system 60 from the water injection start timing of the downstream water injection system 50 by the calculated waiting time ΔT11 minutes.
 具体的には、制御部112は、検出部91によるクランク角度検出値を取得し、図8に示すように、クランク角度検出値がクランク角度R11となったタイミングT11に下流側注水系統50の制御弁55に対して開駆動を指示する。これにより、制御部112は、下流側注水系統50の第1注水ポンプ51を作動開始させる。この制御に基づいて、第1注水ポンプ51は、燃料流通経路の第1注水位置P1への注水を開始する。すなわち、クランク角度R11のタイミングT11は、下流側注水系統50の注水開始タイミングである。このタイミングT11では、図9に示すように、燃料流通経路内の燃料柱201のうち第1注水位置P1への水203の注入が開始されている。この第1注水位置P1への水203の注入開始に伴い、第1注水位置P1と第2注水位置P2との間の燃料は、第2注水位置P2を越えて流通方向上流側に押し戻され始める。これにより、第1注水位置P1と第2注水位置P2との間の燃料量は、減少するように調整され始める。 Specifically, the control unit 112 acquires the crank angle detection value by the detection unit 91, and as shown in FIG. 8, controls the downstream side water injection system 50 at timing T11 when the crank angle detection value becomes the crank angle R11. The valve 55 is instructed to open. Thereby, the control part 112 starts the operation | movement of the 1st water injection pump 51 of the downstream water injection system 50. FIG. Based on this control, the first water injection pump 51 starts water injection to the first water injection position P1 of the fuel flow path. That is, the timing T11 of the crank angle R11 is the water injection start timing of the downstream side water injection system 50. At this timing T11, as shown in FIG. 9, the injection of water 203 into the first water injection position P1 in the fuel column 201 in the fuel flow path is started. With the start of injection of water 203 into the first water injection position P1, the fuel between the first water injection position P1 and the second water injection position P2 starts to be pushed back upstream in the flow direction beyond the second water injection position P2. . Accordingly, the fuel amount between the first water injection position P1 and the second water injection position P2 starts to be adjusted so as to decrease.
 なお、前回の燃料噴射完了後から上記注水開始タイミング(タイミングT11)までの期間内のタイミングT0では、図9に示すように、燃料柱201に対する注水は開始されていない。このときの燃料柱201の燃料量は、上述した燃料噴射量Qfaに相当する。 In addition, as shown in FIG. 9, the water injection to the fuel column 201 is not started at the timing T0 within the period from the completion of the previous fuel injection to the water injection start timing (timing T11). The fuel amount of the fuel column 201 at this time corresponds to the fuel injection amount Qfa described above.
 ついで、制御部112は、上述したように算出した待機時間ΔT11分、下流側注水系統50の注水開始タイミングから遅らせたタイミングに、上流側注水系統60による注水を開始させる。具体的には、制御部112は、上流側注水系統60の待機時間ΔT11を、エンジン負荷に応じたエンジン回転数とエンジン回転の経過時間とをもとにクランク角度の変化量ΔRに変換する。制御部112は、得られたクランク角度の変化量ΔRと、下流側注水系統50の注水開始タイミング(タイミングT11)時のクランク角度R11とを加算して、クランク角度R12を算出する。制御部112は、図8に示すように、クランク角度検出値がクランク角度R12となったタイミングT12に上流側注水系統60の制御弁65に対して開駆動を指示する。これにより、制御部112は、下流側注水系統50の第1注水ポンプ51の作動を継続させながら、上流側注水系統60の第2注水ポンプ61を作動開始させる。この制御に基づいて、第2注水ポンプ61は、燃料流通経路の第2注水位置P2への注水を開始する。すなわち、クランク角度R12のタイミングT12は、上流側注水系統60の注水開始タイミングである。一方、第1注水ポンプ51は、燃料流通経路の第1注水位置P1への注水を継続して行っている。このタイミングT12では、図9に示すように、燃料流通経路内の燃料柱201のうち、第1注水位置P1への水203の注入が継続して行われながら、第2注水位置P2への水202の注入が開始されている。 Next, the control unit 112 starts the water injection by the upstream side water injection system 60 at a timing delayed from the water injection start timing of the downstream side water injection system 50 for the waiting time ΔT11 minutes calculated as described above. Specifically, the control unit 112 converts the standby time ΔT11 of the upstream water injection system 60 into a crank angle change amount ΔR based on the engine speed corresponding to the engine load and the elapsed time of the engine rotation. The control unit 112 calculates the crank angle R12 by adding the obtained change amount ΔR of the crank angle and the crank angle R11 at the water injection start timing (timing T11) of the downstream water injection system 50. As shown in FIG. 8, the control unit 112 instructs the control valve 65 of the upstream water injection system 60 to open at timing T12 when the detected crank angle value becomes the crank angle R12. Thereby, the control unit 112 starts the operation of the second water injection pump 61 of the upstream side water injection system 60 while continuing the operation of the first water injection pump 51 of the downstream side water injection system 50. Based on this control, the second water injection pump 61 starts water injection to the second water injection position P2 of the fuel flow path. That is, the timing T12 of the crank angle R12 is the water injection start timing of the upstream water injection system 60. On the other hand, the first water injection pump 51 continuously performs water injection to the first water injection position P1 of the fuel flow path. At this timing T12, as shown in FIG. 9, the water 203 is continuously injected into the first water injection position P1 in the fuel column 201 in the fuel flow path, and the water is supplied to the second water injection position P2. 202 injection has started.
 その後、第1注水ポンプ51は、制御弁55が閉駆動するまでの期間、燃料流通経路の第1注水位置P1への注水を継続して行う。これに並行して、第2注水ポンプ61は、制御弁65が閉駆動するまでの期間、燃料流通経路の第2注水位置P2への注水を継続して行う。 Thereafter, the first water injection pump 51 continues to inject water into the first water injection position P1 of the fuel flow path until the control valve 55 is driven to close. In parallel with this, the second water injection pump 61 continues water injection to the second water injection position P2 of the fuel flow path until the control valve 65 is driven to close.
 例えば、図8、9に示すように、クランク角度R11からクランク角度Raまでの時間ΔT13の期間では、第1注水位置P1の水203の注入が進む。また、この期間のうち、クランク角度R12からクランク角度Ra(>R12)までの時間ΔTaの期間では、第1注水位置P1の水203の注入が進むとともに、第2注水位置P2の水202の注入が進む。この第1注水位置P1の水203の注入に伴い、第1注水位置P1と第2注水位置P2との間の燃料は、第2注水位置P2または水202を越えて流通方向上流側に押し戻される。これにより、第1注水位置P1と第2注水位置P2との間の燃料量は、時間ΔT13の期間、減少するように調整される。 For example, as shown in FIGS. 8 and 9, in the period of time ΔT13 from the crank angle R11 to the crank angle Ra, the injection of water 203 at the first water injection position P1 proceeds. Further, during this period, during the period of time ΔTa from the crank angle R12 to the crank angle Ra (> R12), the injection of the water 203 at the first water injection position P1 proceeds and the water 202 at the second water injection position P2 is injected. Advances. With the injection of the water 203 at the first water injection position P1, the fuel between the first water injection position P1 and the second water injection position P2 is pushed back upstream in the flow direction beyond the second water injection position P2 or the water 202. . Thereby, the fuel amount between the 1st water injection position P1 and the 2nd water injection position P2 is adjusted so that it may reduce during the period of time (DELTA) T13.
 また、この時間ΔT13の期間のうち、クランク角度R13のタイミングT13では、第1注水位置P1の水203が、燃料柱201の幅方向全域に広がるまで注入されている。この際、第1注水位置P1の水203は、図9に示すように、燃料柱201を、第1注水位置P1よりも下流側に位置する最下流燃料201cと、第1注水位置P1よりも上流側に位置する上流側燃料201eとに分ける。この段階において、最下流燃料201cの燃料量が決まる。また、クランク角度R13からクランク角度R14(>R13)までの期間では、第1注水位置P1の水203が燃料柱201の幅方向全域に広がった状態から更に注入されるとともに、第2注水位置P2の水202が継続して注入されている。この段階において、第1注水位置P1の水203の注入は、第1注水位置P1と第2注水位置P2との間の燃料を第2注水位置P2よりも流通方向上流側へ押し戻しながら行われる。 Further, in the period of time ΔT13, at the timing T13 of the crank angle R13, the water 203 at the first water injection position P1 is injected until it spreads over the entire width direction of the fuel column 201. At this time, as shown in FIG. 9, the water 203 at the first water injection position P1 moves the fuel column 201 from the most downstream fuel 201c located downstream of the first water injection position P1 and from the first water injection position P1. The fuel is divided into the upstream fuel 201e located on the upstream side. At this stage, the fuel amount of the most downstream fuel 201c is determined. Further, in the period from the crank angle R13 to the crank angle R14 (> R13), the water 203 at the first water injection position P1 is further injected from the state where it spreads over the entire width direction of the fuel column 201, and at the second water injection position P2. Of water 202 is continuously injected. In this stage, the injection of the water 203 at the first water injection position P1 is performed while pushing back the fuel between the first water injection position P1 and the second water injection position P2 to the upstream side in the flow direction from the second water injection position P2.
 一方、クランク角度Raのタイミングでは、第2注水位置P2の水202が、燃料柱201の幅方向全域に広がるまで注入されている。この際、第2注水位置P2の水202は、燃料柱201のうちの上流側燃料201eを、第2注水位置P2よりも上流側に位置する最上流燃料201bと、第2注水位置P2の水202と第1注水位置P1の水203とに挟まれる注水層間燃料201dとに分ける。この段階において、第1注水位置P1と第2注水位置P2との間の燃料は、第1注水位置P1の水203の注入が進行しても、第2注水位置P2の水202を越えて流通方向上流側に押し戻されることが無くなる。これにより、第1注水位置P1と第2注水位置P2との間の燃料量の調整が終了し、注水層間燃料201dの燃料量、すなわち注水層間の燃料量(=Qf2)が決まる。 On the other hand, at the timing of the crank angle Ra, the water 202 at the second water injection position P2 is injected until it spreads over the entire width direction of the fuel column 201. At this time, the water 202 at the second water injection position P2 includes the upstream fuel 201e of the fuel column 201, the upstream fuel 201b positioned upstream of the second water injection position P2, and the water at the second water injection position P2. 202 and the water injection interlayer fuel 201d sandwiched between the water 203 at the first water injection position P1. At this stage, the fuel between the first water injection position P1 and the second water injection position P2 circulates over the water 202 at the second water injection position P2 even if the injection of the water 203 at the first water injection position P1 proceeds. No longer being pushed back in the direction upstream. Thereby, the adjustment of the fuel amount between the first water injection position P1 and the second water injection position P2 is completed, and the fuel amount of the water injection interlayer fuel 201d, that is, the fuel amount between the water injection layers (= Qf2) is determined.
 なお、このクランク角度Raのタイミングは、第2注水位置P2の水202が必要量注入されるタイミングT14と同じであってもよいし、前のタイミングであってもよいし、後のタイミングであってもよい。これらのタイミングのうち何れのタイミングがクランク角度Raのタイミングになるかは、エンジン負荷に応じた待機時間ΔT11によって決まる。図9には、クランク角度Raのタイミングがクランク角度R14のタイミングT14と同じタイミングとなっている場合が図示されている。 The timing of the crank angle Ra may be the same as the timing T14 when the required amount of water 202 at the second water injection position P2 is injected, may be the previous timing, or may be the subsequent timing. May be. Which of these timings corresponds to the crank angle Ra is determined by the waiting time ΔT11 corresponding to the engine load. FIG. 9 illustrates a case where the timing of the crank angle Ra is the same as the timing T14 of the crank angle R14.
 また、制御部112は、図8に示すように、クランク角度検出値がクランク角度R14となったタイミングT14に下流側注水系統50の制御弁55に対して閉駆動を指示する。これにより、制御部112は、上流側注水系統60の第2注水ポンプ61の作動を継続させながら、下流側注水系統50の第1注水ポンプ51を作動停止させる。この制御に基づいて、第1注水ポンプ51は、燃料流通経路の第1注水位置P1への注水を終了する。すなわち、クランク角度R14のタイミングT14は、下流側注水系統50の注水終了タイミングである。一方、第2注水ポンプ61は、燃料流通経路の第2注水位置P2への注水を継続して行っている。図9に示すように、クランク角度R14のタイミングT14では、第1注水位置P1の水203が必要量注入された状態となっている。 Further, as shown in FIG. 8, the control unit 112 instructs the control valve 55 of the downstream water injection system 50 to be closed at timing T14 when the crank angle detection value becomes the crank angle R14. Thereby, the control unit 112 stops the operation of the first water injection pump 51 of the downstream side water injection system 50 while continuing the operation of the second water injection pump 61 of the upstream side water injection system 60. Based on this control, the first water injection pump 51 ends water injection to the first water injection position P1 of the fuel flow path. That is, the timing T14 of the crank angle R14 is the water injection end timing of the downstream water injection system 50. On the other hand, the second water injection pump 61 continuously performs water injection to the second water injection position P2 of the fuel flow path. As shown in FIG. 9, at the timing T14 of the crank angle R14, a necessary amount of water 203 at the first water injection position P1 is injected.
 その後、制御部112は、図8に示すように、クランク角度検出値がクランク角度R15となったタイミングT15に上流側注水系統60の制御弁65に対して閉駆動を指示する。これにより、制御部112は、上流側注水系統60の第2注水ポンプ61を作動停止させる。この制御に基づいて、第2注水ポンプ61は、燃料流通経路の第2注水位置P2への注水を終了する。すなわち、クランク角度R15のタイミングT15は、上流側注水系統60の注水終了タイミングである。 Thereafter, as shown in FIG. 8, the control unit 112 instructs the control valve 65 of the upstream water injection system 60 to be closed at a timing T15 when the crank angle detection value becomes the crank angle R15. Thereby, the control part 112 stops the operation | movement of the 2nd water injection pump 61 of the upstream water injection system 60. FIG. Based on this control, the second water injection pump 61 ends water injection to the second water injection position P2 of the fuel flow path. That is, the timing T15 of the crank angle R15 is the water injection end timing of the upstream water injection system 60.
 例えば、図9に示すように、クランク角度R14のタイミングT14からクランク角度R15(>R14)のタイミングT15までの期間では、第2注水位置P2の水202が、燃料柱201の幅方向全域に広がった状態から更に注入されている。一方、第1注水位置P1の水203の注入は、上述したタイミングT14で既に終了している。この段階において、第2注水位置P2の水202の注入は、上述したタイミングT13からタイミングT14までの期間と同様に行われ、水202の注入量が必要量になるまで継続される。そして、クランク角度R15のタイミングT15では、第2注水位置P2および第1注水位置P1の各注水が終了する。この結果、第1燃料層F1と第1注水層W1と第2燃料層F2と第2注水層W2と第3燃料層F3とからなる層状液体200が、燃料流通経路内に形成される。 For example, as shown in FIG. 9, during the period from the timing T14 of the crank angle R14 to the timing T15 of the crank angle R15 (> R14), the water 202 at the second water injection position P2 spreads over the entire width direction of the fuel column 201. It is further injected from the state. On the other hand, the injection of the water 203 at the first water injection position P1 has already ended at the timing T14 described above. In this stage, the injection of the water 202 at the second water injection position P2 is performed in the same manner as the period from the timing T13 to the timing T14 described above, and is continued until the injection amount of the water 202 becomes a necessary amount. And in timing T15 of crank angle R15, each water injection of the 2nd water injection position P2 and the 1st water injection position P1 is completed. As a result, a stratified liquid 200 composed of the first fuel layer F1, the first water injection layer W1, the second fuel layer F2, the second water injection layer W2, and the third fuel layer F3 is formed in the fuel flow path.
 ここで、本実施形態2において、下流側注水系統50の注水期間は、クランク角度R11のタイミングT11からクランク角度R14のタイミングT14までの期間である。すなわち、下流側注水系統50の注水期間は、図8に示す待機時間ΔT11と時間ΔT12とを加算した時間分の期間である。この注水期間は、図9に示す第1注水位置P1に必要量の水203を注入する際に掛かる時間によって決まる。すなわち、下流側注水系統50の注水終了タイミング(タイミングT14)に対応するクランク角度R14は、注水開始タイミングに対応するクランク角度R11と、上記必要量の水203の注入に要する時間とをもとに導出される。 Here, in the second embodiment, the water injection period of the downstream side water injection system 50 is a period from the timing T11 of the crank angle R11 to the timing T14 of the crank angle R14. That is, the water injection period of the downstream water injection system 50 is a period corresponding to the time obtained by adding the waiting time ΔT11 and the time ΔT12 shown in FIG. This water injection period is determined by the time required for injecting a required amount of water 203 into the first water injection position P1 shown in FIG. That is, the crank angle R14 corresponding to the water injection end timing (timing T14) of the downstream side water injection system 50 is based on the crank angle R11 corresponding to the water injection start timing and the time required to inject the required amount of water 203. Derived.
 また、上流側注水系統60の注水期間は、クランク角度R12のタイミングT12からクランク角度R15のタイミングT15までの期間である。この注水期間は、図9に示す第2注水位置P2に必要量の水202を注入する際に掛かる時間によって決まる。すなわち、上流側注水系統60の注水終了タイミング(タイミングT15)に対応するクランク角度R15は、注水開始タイミングに対応するクランク角度R12と、上記必要量の水202の注入に要する時間とをもとに導出される。 Further, the water injection period of the upstream water injection system 60 is a period from the timing T12 of the crank angle R12 to the timing T15 of the crank angle R15. This water injection period is determined by the time taken to inject the required amount of water 202 into the second water injection position P2 shown in FIG. That is, the crank angle R15 corresponding to the water injection end timing (timing T15) of the upstream water injection system 60 is based on the crank angle R12 corresponding to the water injection start timing and the time required for injecting the required amount of water 202. Derived.
 本実施形態2において、下流側注水系統50の注水期間と上流側注水系統60の注水期間との重なる期間は、図8に示すように、クランク角度R12からクランク角度R14までの時間ΔT12に相当する。この期間のうち、クランク角度R12からクランク角度Raまでの時間ΔTaの期間は、下流側注水系統50の注水によって注水層間の燃料量が減量調整される期間の一部である。また、クランク角度R11からクランク角度R12までの待機時間ΔT11の期間は、上記注水層間の燃料量が減量調整される期間の残部である。すなわち、これらの待機時間ΔT11と時間ΔTaとを加算した時間ΔT13の期間が、上記注水層間の燃料量が減量調整される全期間となる。上流側注水系統60の注水開始タイミングは、エンジン負荷の増加に伴って時間ΔT13が減少し、エンジン負荷の減少に伴って時間ΔT13が増加するように、下流側注水系統50の注水開始タイミングから待機時間ΔT11だけ遅れるタイミングに制御される。すなわち、この待機時間ΔT11は、エンジン負荷の増加に伴って減少し、エンジン負荷の減少に伴って増加する。なお、この待機時間ΔT11が零値(ΔT11=0)である場合、上流側注水系統60の注水開始タイミングは、下流側注水系統50の注水開始タイミングと同時のタイミングに制御される。 In the second embodiment, the overlapping period of the water injection period of the downstream water injection system 50 and the water injection period of the upstream water injection system 60 corresponds to the time ΔT12 from the crank angle R12 to the crank angle R14 as shown in FIG. . Among these periods, a period of time ΔTa from the crank angle R12 to the crank angle Ra is a part of a period in which the fuel amount between the water injection layers is adjusted to be reduced by water injection from the downstream water injection system 50. Further, the period of the standby time ΔT11 from the crank angle R11 to the crank angle R12 is the remainder of the period during which the fuel amount between the water injection layers is adjusted to decrease. That is, a period of time ΔT13 obtained by adding the waiting time ΔT11 and time ΔTa is an entire period in which the fuel amount between the water injection layers is adjusted to be reduced. The water injection start timing of the upstream water injection system 60 waits from the water injection start timing of the downstream water injection system 50 so that the time ΔT13 decreases as the engine load increases and the time ΔT13 increases as the engine load decreases. The timing is controlled to be delayed by time ΔT11. That is, this waiting time ΔT11 decreases with an increase in engine load, and increases with a decrease in engine load. When the waiting time ΔT11 is a zero value (ΔT11 = 0), the water injection start timing of the upstream side water injection system 60 is controlled at the same time as the water injection start timing of the downstream side water injection system 50.
 以上、説明したように、本発明の実施形態2に係る燃料噴射装置110では、下流側注水系統50の注水期間と上流側注水系統60の注水期間との少なくとも一部が重なるようにすべく、下流側注水系統50が注水を開始してから上流側注水系統60が注水を開始するまでの上流側注水系統60の待機時間ΔT11をエンジン負荷に応じて算出し、算出した待機時間ΔT11分、上流側注水系統60の注水開始タイミングを下流側注水系統50の注水開始タイミングよりも遅らせるように、下流側注水系統50および上流側注水系統60の各注水開始タイミングを制御するようにし、その他を実施形態1と同様にしている。このため、上述した実施形態1の場合と同様の作用効果を享受するとともに、下流側注水系統50の注水によって注水層間の燃料量を減量調整し得る時間を、上流側注水系統60を先に注水する場合に比べて広範囲に調整することができ、これにより、エンジン負荷に応じた燃料噴射量に対する注水層間の燃料量の割合を簡易に最適化できるようになる。 As described above, in the fuel injection device 110 according to Embodiment 2 of the present invention, at least a part of the water injection period of the downstream water injection system 50 and the water injection period of the upstream water injection system 60 overlap, The standby time ΔT11 of the upstream side water injection system 60 from when the downstream side water injection system 50 starts water injection to when the upstream side water injection system 60 starts water injection is calculated according to the engine load, and the calculated standby time ΔT11 minutes, upstream The water injection start timings of the downstream water injection system 50 and the upstream water injection system 60 are controlled so that the water injection start timing of the side water injection system 60 is delayed from the water injection start timing of the downstream water injection system 50, and the other embodiments Same as 1. For this reason, while enjoying the effect similar to the case of Embodiment 1 mentioned above, the upstream water injection system 60 is water-filled first for the time which can reduce the fuel quantity between water injection layers by the water injection of the downstream water injection system 50. Compared with the case where it does, it can adjust in a wide range, and it becomes possible to optimize easily the ratio of the fuel quantity between the water injection layers with respect to the fuel injection quantity according to engine load.
 なお、上述した実施形態1、2では、下流側注水系統50および上流側注水系統60の各注水開始タイミングを制御する際、エンジン負荷に応じて算出した注水開始の待機時間(例えばΔT1またはΔT11)からクランク角度を算出し、得られたクランク角度と検出部91によるクランク角度検出値とが一致するタイミングを、先の注水開始タイミングに続く後の注水開始タイミングとしていたが、本発明は、これに限定されるものではない。例えば、舶用ディーゼルエンジンのエンジン回転時の経過時間(すなわち時間軸)に沿って下流側注水系統50および上流側注水系統60の各注水開始タイミングを制御し、先の注水開始タイミングからの経過時間がエンジン負荷に応じた待機時間に達したタイミングを後の注水開始タイミングとしてもよい。 In the first and second embodiments described above, when controlling the water injection start timing of the downstream water injection system 50 and the upstream water injection system 60, the water injection start standby time calculated according to the engine load (for example, ΔT1 or ΔT11). The crank angle is calculated from the above, and the timing at which the obtained crank angle coincides with the crank angle detection value by the detector 91 is set as the water injection start timing following the previous water injection start timing. It is not limited. For example, the water injection start timings of the downstream water injection system 50 and the upstream water injection system 60 are controlled along the elapsed time (that is, the time axis) when the marine diesel engine rotates, and the elapsed time from the previous water injection start timing is controlled. The timing when the standby time corresponding to the engine load is reached may be set as the subsequent water injection start timing.
 また、上述した実施形態1、2では、3つの燃料噴射弁30を備えた燃料噴射装置を例示したが、本発明は、これに限定されるものではない。例えば、本発明において、燃料噴射弁30の配置数は、3つに限らず、1つでもよいし、複数(2つ以上)でもよい。 In the first and second embodiments described above, the fuel injection device including the three fuel injection valves 30 is illustrated, but the present invention is not limited to this. For example, in the present invention, the number of fuel injection valves 30 is not limited to three, but may be one or more (two or more).
 また、上述した実施形態1、2により本発明が限定されるものではなく、上述した各構成要素を適宜組み合わせて構成したものも本発明に含まれる。その他、上述した実施形態1、2に基づいて当業者等によりなされる他の実施形態、実施例および運用技術等は全て本発明の範疇に含まれる。 Further, the present invention is not limited by the above-described first and second embodiments, and the present invention includes a configuration in which the above-described constituent elements are appropriately combined. In addition, other embodiments, examples, operation techniques, and the like made by those skilled in the art based on Embodiments 1 and 2 described above are all included in the scope of the present invention.
 以上のように、本発明に係る燃料噴射装置は、舶用ディーゼルエンジンのシリンダ内の燃焼室に対する燃料および水の噴射に有用であり、特に、エンジン負荷に応じて注水層間の燃料量を調整することができる燃料噴射装置に適している。 As described above, the fuel injection device according to the present invention is useful for injecting fuel and water into the combustion chamber in the cylinder of the marine diesel engine, and in particular, adjusting the amount of fuel between the water injection layers according to the engine load. Suitable for a fuel injection device capable of
 1 台板
 2 クランクシャフト
 3 軸受
 4 クランク
 5 架構
 6 連接棒
 7 ガイド板
 8 クロスヘッド
 9 クロスヘッドピン
 10 舶用ディーゼルエンジン
 11 シリンダジャケット
 12 シリンダ
 13 シリンダライナ
 14 シリンダカバー
 15 ピストン
 16 ピストン棒
 17 燃焼室
 18 排気弁
 19 動弁装置
 20 排気管
 21 タイボルト
 22 ナット
 30 燃料噴射弁
 31 噴射口
 32、33 内部流通経路
 34a、34b 逆止弁
 40 燃料圧送系統
 41 燃料噴射ポンプ
 42 燃料噴射管
 42a、42b、42c 分岐管
 43 分岐部
 45 制御弁
 50 下流側注水系統
 51 第1注水ポンプ
 52 下流側注水管
 52a、52b、52c 分岐管
 53 分岐部
 54 逆止弁
 55 制御弁
 60 上流側注水系統
 61 第2注水ポンプ
 62 上流側注水管
 62a、62b、62c 分岐管
 63 分岐部
 64 逆止弁
 65 制御弁
 71 水供給ポンプ
 72 給水管
 72a、72b 分岐管
 73a、73b 逆止弁
 81 蓄圧部
 82 高圧ポンプ
 91 検出部
 92、112 制御部
 100、110 燃料噴射装置
 200 層状液体
 201 燃料柱
 201a 下流側燃料
 201b 最上流燃料
 201c 最下流燃料
 201d 注水層間燃料
 201e 上流側燃料
 202、203 水
 F1 第1燃料層
 F2 第2燃料層
 F3 第3燃料層
 L1 第1液体層
 L2 第2液体層
 L3 第3液体層
 L4 第4液体層
 L5 第5液体層
 P1 第1注水位置
 P2 第2注水位置
 S1、S2 弁制御信号
 W1 第1注水層
 W2 第2注水層
DESCRIPTION OF SYMBOLS 1 Base plate 2 Crankshaft 3 Bearing 4 Crank 5 Frame 6 Connecting rod 7 Guide plate 8 Crosshead 9 Crosshead pin 10 Marine diesel engine 11 Cylinder jacket 12 Cylinder 13 Cylinder liner 14 Cylinder cover 15 Piston 16 Piston rod 17 Combustion chamber 18 Exhaust valve 19 valve operating device 20 exhaust pipe 21 tie bolt 22 nut 30 fuel injection valve 31 injection port 32, 33 internal flow path 34a, 34b check valve 40 fuel pumping system 41 fuel injection pump 42 fuel injection pipe 42a, 42b, 42c branch pipe 43 Branch portion 45 Control valve 50 Downstream side water injection system 51 First water injection pump 52 Downstream side water injection pipe 52a, 52b, 52c Branch pipe 53 Branch portion 54 Check valve 55 Control valve 60 Upstream water injection system 61 Second water injection pump 62 Upstream side Water injection pipe 6 a, 62b, 62c Branch pipe 63 Branch section 64 Check valve 65 Control valve 71 Water supply pump 72 Water supply pipe 72a, 72b Branch pipe 73a, 73b Check valve 81 Pressure accumulating section 82 High pressure pump 91 Detection section 92, 112 Control section 100 , 110 Fuel injector 200 Stratified liquid 201 Fuel column 201a Downstream fuel 201b Uppermost fuel 201c Outermost fuel 201d Water injection fuel 201e Upstream fuel 202, 203 Water F1 First fuel layer F2 Second fuel layer F3 Third fuel layer L1 1st liquid layer L2 2nd liquid layer L3 3rd liquid layer L4 4th liquid layer L5 5th liquid layer P1 1st water injection position P2 2nd water injection position S1, S2 Valve control signal W1 1st water injection layer W2 2nd water injection layer

Claims (5)

  1.  舶用ディーゼルエンジンのシリンダに設けられる燃料噴射弁と、
     配管を通じて前記燃料噴射弁に燃料を圧送する燃料噴射ポンプと、
     前記燃料噴射ポンプから前記燃料噴射弁の噴射口に至る燃料流通経路の所定の位置に水を注入する第1の注水系統と、
     前記燃料流通経路のうち、前記第1の注水系統よりも前記燃料の流通方向上流側の位置に水を注入する第2の注水系統と、
     前記第1の注水系統の注水期間と前記第2の注水系統の注水期間との少なくとも一部が重なるように、前記舶用ディーゼルエンジンの負荷に応じて前記第1の注水系統および前記第2の注水系統の各注水開始タイミングを制御する制御部と、
     を備え、
     前記燃料噴射弁は、前記燃料噴射ポンプによって圧送された前記燃料と、前記第1の注水系統によって注入された水と、前記第2の注水系統によって注入された水とを前記噴射口から前記シリンダ内の燃焼室へ層状に噴射することを特徴とする燃料噴射装置。
    A fuel injection valve provided in a cylinder of a marine diesel engine;
    A fuel injection pump for pumping fuel to the fuel injection valve through piping;
    A first water injection system for injecting water into a predetermined position of a fuel flow path from the fuel injection pump to an injection port of the fuel injection valve;
    A second water injection system for injecting water to a position upstream of the first water injection system in the fuel distribution direction in the fuel distribution path;
    The first water injection system and the second water injection according to the load of the marine diesel engine so that at least part of the water injection period of the first water injection system and the water injection period of the second water injection system overlap. A control unit that controls the start timing of each water injection in the system;
    With
    The fuel injection valve supplies the fuel pumped by the fuel injection pump, water injected by the first water injection system, and water injected by the second water injection system from the injection port to the cylinder. A fuel injection device for injecting into a combustion chamber in layers.
  2.  前記制御部は、前記第1の注水系統によって注入された水の層と前記第2の注水系統によって注入された水の層との間の燃料量が前記燃料の1回当りの噴射量に対して一定の割合となるように、前記第1の注水系統および前記第2の注水系統の各注水開始タイミングを制御することを特徴とする請求項1に記載の燃料噴射装置。 The control unit is configured such that the amount of fuel between the layer of water injected by the first water injection system and the layer of water injected by the second water injection system is equal to the amount of fuel injected per time. 2. The fuel injection device according to claim 1, wherein each water injection start timing of the first water injection system and the second water injection system is controlled so that the ratio is constant.
  3.  前記制御部は、前記舶用ディーゼルエンジンの負荷に応じて、前記第2の注水系統が注水を開始してから前記第1の注水系統が注水を開始するまでの前記第1の注水系統の待機時間を算出し、算出した前記待機時間分、前記第1の注水系統の注水開始タイミングを前記第2の注水系統の注水開始タイミングよりも遅らせることを特徴とする請求項1または2に記載の燃料噴射装置。 The control unit waits for the first water injection system from when the second water injection system starts water injection to when the first water injection system starts water injection according to the load of the marine diesel engine. The fuel injection according to claim 1, wherein the water injection start timing of the first water injection system is delayed from the water injection start timing of the second water injection system by the calculated waiting time. apparatus.
  4.  前記制御部は、前記舶用ディーゼルエンジンの負荷に応じて、前記第1の注水系統が注水を開始してから前記第2の注水系統が注水を開始するまでの前記第2の注水系統の待機時間を算出し、算出した前記待機時間分、前記第2の注水系統の注水開始タイミングを前記第1の注水系統の注水開始タイミングよりも遅らせることを特徴とする請求項1または2に記載の燃料噴射装置。 The control unit waits for the second water injection system from the time when the first water injection system starts water injection until the second water injection system starts water injection according to the load of the marine diesel engine. The fuel injection according to claim 1, wherein the water injection start timing of the second water injection system is delayed from the water injection start timing of the first water injection system by the calculated waiting time. apparatus.
  5.  前記第1の注水系統による注水量と前記第2の注水系統による注水量との比は一定であることを特徴とする請求項1~4のいずれか一つに記載の燃料噴射装置。 The fuel injection device according to any one of claims 1 to 4, wherein a ratio of a water injection amount by the first water injection system and a water injection amount by the second water injection system is constant.
PCT/JP2019/004476 2018-02-13 2019-02-07 Fuel injection device WO2019159816A1 (en)

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JPH06257530A (en) * 1993-03-04 1994-09-13 Mitsubishi Heavy Ind Ltd Stratified injection device for fuel and water
JP2015102049A (en) * 2013-11-26 2015-06-04 川崎重工業株式会社 Ship engine system using pilot fuel and ship

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KR20200105719A (en) 2020-09-08
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CN111699309A (en) 2020-09-22
JP7102160B2 (en) 2022-07-19

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