KR102375343B1 - fuel injector - Google Patents

Abstract

In the fuel injection device of one aspect of the present invention, the fuel injection valve is formed in a cylinder of a marine diesel engine. A fuel injection pump pumps fuel to a fuel injection valve through piping. The 1st water injection system injects water into the predetermined position of the fuel distribution path|route from a fuel injection pump to the injection port of a fuel injection valve. The second water injection system injects water into a position on the upstream side of the fuel flow direction from the first water injection system in the fuel flow path. The control unit controls each watering start timing of the first watering system and the second watering system according to the engine load so that at least a part of the watering period of the first watering system and the watering period of the second watering line overlap. The fuel injection valve injects the fuel by the pressure feed of the fuel injection pump, the water by the injection of the first injection system, and the water by the injection of the second injection system in a layered manner from the injection port to the combustion chamber in the cylinder.

Description

fuel injector

The present invention relates to a fuel injection device for a marine diesel engine mounted on a ship.

Conventionally, in the field of ships, as a method of reducing nitrogen oxides (NOx) in exhaust gas discharged from a marine diesel engine, a water injection technique for injecting fuel and water into a combustion chamber in a cylinder has been proposed (for example, a patent References 1 to 4).

In the water injection technique disclosed in Patent Documents 1 to 4, water is injected into a flow path of fuel pumped from a fuel injection pump to a fuel injection valve, and a plurality of fuel layers and a water injection layer ( The fuel and water are formed in a multi-layered liquid column shape so that the layers of injected water) are alternately arranged. The fuel and water in this multi-layered liquid column are fed from one fuel injection valve to the combustion chamber in the cylinder in the order of arrangement of the plurality of fuel layers and the main water layer (for example, fuel-water-fuel-water-fuel, etc.) sprayed in layers.

Japanese Patent Laid-Open No. 6-123255 Japanese Laid-Open Patent Publication No. 6-257530 Japanese Patent Laid-Open No. 4-175446 Japanese Laid-Open Patent Publication No. 5-288129

By the way, in the water injection technique in which fuel and water are injected in a layered manner as described above, the amount of fuel in the fuel layer sandwiched between each cast water layer in the fuel distribution path (hereinafter referred to as the fuel amount between the main water layers) is a very important factor in terms of securing stable performance of a marine diesel engine. That is, when the ratio of the fuel amount between the water layers to the fuel injection amount per one time to the combustion chamber (hereinafter referred to as fuel injection amount) is excessive or too small, the marine diesel engine causes poor combustion or deterioration of fuel efficiency, etc. or is likely to do so. In order to avoid such a situation, it is preferable to adjust the fuel amount between the main water layers so that the ratio with respect to the fuel injection amount does not become too large or too small.

However, in the above-mentioned prior art, after water injection of one water injection layer is completed among each water injection layer on the downstream side (injection port side of a fuel injection valve) and upstream side (fuel injection pump side) across the fuel layer, the other Since the watering of the watering layers is performed, it is difficult to adjust the amount of fuel between the watering layers so that the ratio with respect to the fuel injection amount does not become too large or too small. In addition to this, a fuel injection amount normally increases with the increase of the load of a marine diesel engine (hereinafter, referred to as an engine load appropriately), and decreases with a decrease. For this reason, in the above-mentioned prior art, although there is a possibility that the fuel amount between the main water layers is in a ratio that is neither excessive nor too small to the fuel injection amount at a certain engine load, the fuel injection amount at other engine loads. In many cases, the ratio of the fuel amount between the water column to the water column is too large or too small, so it is difficult to adjust the fuel amount between the water column layers according to the engine load.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fuel injection device capable of adjusting the amount of fuel between the water column in accordance with the engine load.

In order to solve the above-mentioned subject and achieve the objective, the fuel injection apparatus which concerns on this invention is fuel injection which pressurizes fuel to the said fuel injection valve through the fuel injection valve formed in the cylinder of a marine diesel engine, and piping. a pump, a first water injection system that injects water into a predetermined position of a fuel distribution path from the fuel injection pump to an injection port of the fuel injection valve, and a first water injection system in the fuel distribution path that distributes the fuel from the first water injection system In accordance with the load of the marine diesel engine, a second water supply system for injecting water into a position on the upstream side of the direction overlaps with at least a part of the water supply period of the first water supply system and the water supply period of the second water system. a control unit for controlling each watering start timing of the first water injection system and the second water injection system, wherein the fuel injection valve includes the fuel pumped by the fuel injection pump and water injected by the first water injection system. And, it is characterized in that the water injected by the second water injection system is injected in a layered manner from the injection port to the combustion chamber in the cylinder.

Further, in the fuel injection device according to the present invention, in the above invention, the control unit includes: the amount of fuel between the layer of water injected by the first injection system and the layer of water injected by the second injection system is the fuel It is characterized in that the watering start timing of each of the first watering system and the second watering system is controlled so as to be a constant ratio with respect to the injection amount per one time.

Further, in the fuel injection device according to the present invention, in the above invention, in the control unit, the first water injection system starts watering after the second water injection system starts watering according to the load of the marine diesel engine. The waiting time of the first watering system is calculated until the watering time of the first watering line is calculated, and the watering start timing of the first watering line is delayed from the watering start timing of the second watering line by the calculated waiting time.

Further, in the fuel injection device according to the present invention, in the above invention, in the control unit, the first water injection system starts watering, and then the second water injection system starts watering according to the load of the marine diesel engine. The waiting time of the second watering system is calculated until the time of irrigation, and the watering start timing of the second watering line is delayed from the watering start timing of the first watering line by the calculated waiting time.

Further, in the fuel injection device according to the present invention, in the above invention, the ratio of the water injection amount by the first water injection system to the water injection amount by the second water injection system is constant.

ADVANTAGE OF THE INVENTION According to this invention, the effect that the fuel amount between water-casting layers can be adjusted according to engine load is acquired.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows one structural example of the marine diesel engine to which the fuel injection device which concerns on Embodiment 1 of this invention was applied.
Fig. 2 is a schematic diagram showing a configuration example of a fuel injection device according to Embodiment 1 of the present invention.
Fig. 3 is a diagram showing a configuration example of a layered liquid in a fuel flow path according to Embodiment 1 of the present invention.
Fig. 4 is a diagram for explaining control of watering timing in Embodiment 1 of the present invention.
It is a figure for demonstrating adjustment of the fuel amount between water-casting layers in Embodiment 1 of this invention.
Fig. 6 is a diagram showing an example of the injection amount according to the engine load of the layered liquid in the first embodiment of the present invention.
Fig. 7 is a schematic diagram showing a configuration example of a fuel injection device according to a second embodiment of the present invention.
Fig. 8 is a diagram for explaining control of watering timing in Embodiment 2 of the present invention.
It is a figure for demonstrating adjustment of the fuel amount between water-casting layers in Embodiment 2 of this invention.

EMBODIMENT OF THE INVENTION Hereinafter, with reference to an accompanying drawing, preferable embodiment of the fuel injection device which concerns on this invention is described in detail. In addition, this invention is not limited by this embodiment. In addition, it is necessary to note that the drawings are schematic, and the relationship between the dimensions of each element, the ratio of each element, etc. may differ from actual ones. Also in each of the drawings, there are cases in which parts having different dimensional relationships and ratios are included. In addition, in each figure, the same code|symbol is attached|subjected to the same structural part.

(Embodiment 1)

First, the structure of the marine diesel engine to which the fuel injection device which concerns on Embodiment 1 of this invention was applied is demonstrated. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows one structural example of the marine diesel engine to which the fuel injection device which concerns on Embodiment 1 of this invention was applied. This marine diesel engine 10 is an engine for propulsion (main engine) which rotates the propeller for propulsion of a ship (all are not shown in figure) via a propeller shaft. For example, the marine diesel engine 10 is a two-stroke diesel engine, such as a uniflow scavenging-exhaust type|mold crosshead type diesel engine.

As shown in FIG. 1, the marine diesel engine 10 has the base plate 1 located below, the furniture 5 formed on the base plate 1, and the furniture 5 A cylinder jacket 11 formed thereon is provided. The base plate 1 , the furniture 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. Moreover, the marine diesel engine 10 interlocks with the cylinder 12 formed in the cylinder jacket 11, the piston 15 formed in the cylinder 12, and the reciprocating motion of the piston 15, and the output shaft which rotates (For example, crankshaft 2) is provided.

The base plate 1 constitutes a crankcase of the marine diesel engine 10 . As shown in FIG. 1 , in the base plate 1 , a crankshaft 2 having a crank 4 and a bearing 3 are provided. The crankshaft 2 is supported so that it can rotate freely by the bearing 3 as an example of the output shaft which outputs the propulsion force of a ship. It is connected to this crankshaft 2 via the crank 4 so that the lower end of the connecting rod 6 can rotate freely.

In the furniture 5, as shown in FIG. 1, the connecting rod 6, the guide plate 7, and the crosshead 8 are provided. The furniture 5 is arrange|positioned so that the guide plate 7 formed along the piston axial direction may form a pair at intervals in the width direction. The connecting rod 6 is arranged between the pair of guide plates 7 in such a manner that the lower end thereof is connected to the crankshaft 2 . The crosshead 8 includes a crosshead pin 9 connected to the lower end of the piston rod 16 and a crosshead bearing (not shown) connected to the upper end of the connecting rod 6 , of the crosshead pin 9 . In the lower half, each is connected so that it can rotate freely. As shown in FIG. 1, this crosshead 8 is arrange|positioned between a pair of guide plates 7, and is supported so that it can move freely along this pair of guide plates 7. As shown in FIG.

The cylinder jacket 11 is provided in the upper part of the furniture 5, and supports the cylinder 12, as shown in FIG. The cylinder 12 is a normal structure (cylinder) constituted by the cylinder liner 13 and the cylinder cover 14, and has a combustion chamber 17 for burning fuel. The cylinder liner 13 is disposed in the cylinder jacket 11 as, for example, a cylindrical structure. A cylinder cover 14 is fixed to the upper portion of the cylinder liner 13, whereby a space (combustion chamber 17, etc.) in the cylinder liner 13 is partitioned. In the space portion of the cylinder liner 13, the piston 15 is formed so that it can reciprocate freely in the piston axial direction (up-and-down direction in FIG. 1). The upper end of the piston rod 16 is connected to the lower end of the piston 15 as shown in FIG. 1 .

Moreover, as shown in FIG. 1, the exhaust valve 18 and the valve drive device 19 are provided in the cylinder cover 14. As shown in FIG. The exhaust valve 18 is a valve which opens and closes the exhaust port (exhaust port) of the exhaust pipe 20 which leads to the combustion chamber 17 in the cylinder 12 so that opening and closing is possible. The valve driving device 19 is a device for opening/closing the exhaust valve 18 . The combustion chamber 17 is a space surrounded by such an exhaust valve 18 , the cylinder liner 13 , the cylinder cover 14 , and the piston 15 described above.

1 , the marine diesel engine 10 includes a fuel injection valve 30 , a fuel injection pump 41 , a first injection pump 51 , and a second injection pump 61 . be prepared The fuel injection valve 30 is formed in the cylinder 12 (eg, the cylinder cover 14 ) in such a manner that the injection port is directed into 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. 1 . Although not shown in FIG. 1, the fuel injection pump 41, the 1st water injection pump 51, and the 2nd water injection pump 61 are each connected so that communication with the fuel injection valve 30 is possible via piping or the like. The fuel injection pump 41 pressurizes fuel appropriately to the fuel injection valve 30 through a distribution path by piping or the like. The first water injection pump 51 and the second water injection pump 61 appropriately inject water such as distilled water into the flow path of the fuel pumped by the fuel injection pump 41, respectively. For example, the water injection position by the first water injection pump 51 is on the downstream side of the fuel flow path rather than the water injection position by the second water injection pump 61 . The fuel injection valve 30 injects the fuel pumped by the fuel injection pump 41 , the water injected by the first injection pump 51 , and the water injected by the second injection pump 61 into the fuel. By the pressure feeding action of the injection pump 41, the combustion chamber 17 is alternately injected (that is, sprayed in layers).

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 further for combustion of compressed air or the like. Gas is supplied through a scavenging port or the like (not shown). In the combustion chamber 17, while the supplied fuel is combusted with the gas for combustion, the combustion temperature of the fuel falls by the supplied water, and the discharge amount of NOx is reduced. And, the piston 15 reciprocates in the cylinder 12 in the piston axial direction by the energy generated by combustion of fuel in the combustion chamber 17 . At this time, when the exhaust valve 18 is actuated by the valve driving device 19 to open the cylinder 12 , the exhaust gas generated by the combustion of the fuel is pushed out into the exhaust pipe 20 . On the other hand, the combustion gas is newly introduced into the cylinder 12 from the scavenging port.

Moreover, when the piston 15 reciprocates in the piston axial direction as mentioned above, the piston rod 16 reciprocates with the piston 15 in the piston axial direction. In connection with this, the crosshead 8 reciprocates along the guide plate 7 in the piston axial direction. Thereby, the crosshead pin 9 of the crosshead 8 applies a rotational driving force to the connecting rod 6 via a crosshead bearing. By this rotational driving force, the crank 4 connected to the lower end of the connecting rod 6 cranks (rotates), and as a result, the crankshaft 2 rotates. The crankshaft 2 converts the reciprocating motion of the piston 15 into rotational motion in this way to rotate the propeller for propulsion of the ship together with the propeller shaft, thereby outputting the propulsion force of the ship.

Next, the structure of the fuel injection device which concerns on Embodiment 1 of this invention is demonstrated. Fig. 2 is a schematic diagram showing a configuration example of a fuel injection device according to Embodiment 1 of the present invention. As shown in FIG. 2 , this fuel injection device 100 includes a plurality of (three in the first embodiment) fuel injection valves 30 , a fuel pressure feeding system 40 , and a downstream side water injection system 50 . and an upstream side water supply system (60). In addition, the fuel injection device 100 includes a water supply pump 71 , a water supply pipe 72 , check valves 73a and 73b , a pressure accumulator 81 , a high pressure pump 82 , and a detection unit 91 . ) and a control unit 92 . In addition, in FIG. 2, a solid-line arrow shows the flow|circulation of fluids, such as fuel and water, and a broken-line arrow shows an electric signal line.

The plurality of fuel injection valves 30 are injection valves for injecting fuel and water in a layered manner to the combustion chamber 17 (see FIG. 1 ) in the cylinder 12 of the marine diesel engine 10 . These plurality of fuel injection valves 30 are respectively provided in the cylinders 12 of a plurality (only one is shown in FIG. 1) of the marine diesel engine 10. As shown in FIG. Hereinafter, one of these plurality of fuel injection valves 30 will be exemplified and the configuration of the fuel injection valve 30 will be described. In addition, these some fuel injection valves 30 are respectively comprised similarly.

As shown in FIG. 2 , the fuel injection valve 30 is connected to the fuel injection pump 41 of the fuel pressure delivery system 40 through piping or the like so that communication is possible. The fuel injection valve 30 is connected to the downstream side water injection system 50 and the upstream side water injection system 60 through piping etc. so that communication is possible. The fuel injection valve 30 injects the fuel pumped by the fuel injection pump 41, the water injected by the downstream injection system 50, and the water injected by the upstream injection system 60 to the injection port ( 31) to the combustion chamber 17 in the cylinder 12 in a layered manner.

In detail, 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 34a and 34b. have One of the internal circulation paths 32 is a circulation path for flowing the fuel and water to be injected. This 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 the fuel injection pipe 42 (for example, branch pipe 42a). . Moreover, to the upstream position of this internal flow path 32 (in this Embodiment 1, the 2nd water injection position P2 upstream rather than the 1st water injection position P1), it is upstream via the check valve 34a. The piping of the side water supply system 60 (for example, the branch pipe 62a of the upstream side water supply pipe 62) is connected. The other internal circulation path 33 is a circulation path for flowing the water injected into the internal circulation path 32 . This internal flow path 33 has one end connected to a position in the vicinity of the injection port 31 of the internal flow path 32 (the first water injection position P1 in the first embodiment), and the other end has a downstream side water supply It is connected to the piping of the system 50 (for example, the branch pipe 52a of the downstream main water pipe 52).

The check valve 34a enables the flow of water from the upstream side water supply system 60 to the internal flow path 32 of the fuel injection valve 30 to prevent this reverse flow. The check valve 34b is formed in the intermediate part of the internal flow path 33 . The check valve 34b enables the flow of water from the downstream side main water system 50 to the internal flow path 32 through the internal flow path 33 of the fuel injection valve 30 to prevent this backflow. .

The fuel pressure feeding system 40 is a facility for pressure feeding fuel to the fuel injection valve 30 . As shown in FIG. 2 , the fuel pressure feeding 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 by using the pressure of hydraulic oil. In detail, the fuel injection pump 41 receives fuel from a fuel tank (not shown) through piping etc. The fuel injection pump 41 pressurizes this received fuel to the fuel injection valve 30 via the fuel injection pipe 42 . Moreover, the pressure feeding action of the fuel injection pump 41 causes the fuel injection valve 30 to perform 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 . For example, as shown in FIG. 2 , one end of the fuel injection pipe 42 is connected to a discharge port of the fuel injection pump 41 . Moreover, the branch part 43 is formed in the intermediate part of the fuel injection pipe 42. As shown in FIG. The fuel injection pipe 42 branches from this branching part 43 toward the other end into a plurality of branch pipes (three branch pipes 42a, 42b, 42c in the first embodiment). For example, among the branch pipes 42a , 42b , and 42c of the fuel injection pipe 42 , the branch pipe 42a is, as shown in FIG. 2 , the internal flow path 32 of one fuel injection valve 30 . is connected to The fuel injection pipe 42 connects this fuel injection valve 30 and the fuel injection pump 41 via the branch pipe 42a. Similarly, the remaining branch pipes 42b and 42c are respectively connected to each other fuel injection valve 30 .

The control valve 45 is a valve for controlling the supply of hydraulic oil from the pressure accumulator 81 to the fuel injection pump 41 . Specifically, the control valve 45 is constituted by an electric on/off valve such as a solenoid valve, and although not shown, by opening and closing a logic valve driven by the control valve 45, as shown in FIG. 2 , , the fuel injection pump 41 and the pressure accumulator 81 are formed to communicate with each other. The control valve 45 enters an open state at the fuel injection timing, and supplies the hydraulic oil in the pressure accumulator 81 to the fuel injection pump 41 . The fuel injection pump 41 pressurizes fuel to the fuel injection valve 30 using the pressure of this supplied hydraulic oil. On the other hand, the control valve 45 is in a closed state for a period other than the fuel injection timing, and stops supply of hydraulic oil from the pressure accumulator 81 to the fuel injection pump 41 . The timing of the opening/closing drive of the control valve 45 is controlled by the control unit 92 .

The downstream side water injection system 50 is an example of the 1st water injection system which injects water into the 1st water injection position P1 of the fuel flow path in this Embodiment 1. As shown in FIG. 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 hydraulically driven pump that performs water injection using the pressure of hydraulic oil. Specifically, the first water supply pump 51 receives water from the water supply pump 71 through the water supply pipe 72 or the like. The first water pump 51 transfers the received water through the downstream water main pipe 52 and the internal distribution path 33 of the fuel injection valve 30 to the internal circulation path of the fuel injection valve 30 ( 32) and sent to Thereby, the 1st water injection pump 51 injects water into the 1st water injection position P1 of the fuel flow path in this Embodiment 1. FIG.

The downstream water supply pipe 52 is a pipe for flowing water injected by the first water injection pump 51 to the first water injection position P1 of the fuel distribution path. For example, as shown in FIG. 2 , one end of the downstream water feed pipe 52 is connected to a discharge port of the first water feed pump 51 . Moreover, the branch part 53 is formed in the middle part of the downstream main water pipe 52. As shown in FIG. The downstream main water pipe 52 is branched from this branching part 53 toward the other end into a plurality of branch pipes (in the present embodiment 1, three branch pipes 52a, 52b, 52c. For example, Among the branch pipes 52a, 52b, and 52c of the downstream main water 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 supply pipe 52 communicates the internal flow path 33 of this fuel injection valve 30 and the first water supply pump 51 via the branch pipe 52a. The branch pipes 52b and 52c are respectively connected to each other fuel injection valve 30 .

The check valve 54 is a valve for preventing the reverse flow of water by regulating the flow direction of water in the downstream main pipe 52 in one direction. As shown in FIG. 2 , the check valve 54 is formed in an intermediate portion of the downstream water main pipe 52 (eg, a portion between the first water injection pump 51 and the branching portion 53 ). The check valve 54 enables the circulation of water from the first water pump 51 side to the fuel circulation path side (internal circulation paths 32 and 33 sides of the fuel injection valve 30 in the first embodiment). Thus, this reverse flow is prevented.

The control valve 55 is a valve for controlling the supply of hydraulic oil from the pressure accumulator 81 to the first water pump 51 . Specifically, the control valve 55 is constituted by an electric on/off valve such as a solenoid valve, and as shown in FIG. 2 , the first water pump 51 and the pressure accumulator 81 are formed to communicate with each other. . The control valve 55 is in an open state during a period during which water from the first water injection pump 51 is injected into the fuel distribution path (hereinafter referred to as a water injection period of the downstream side water injection system 50 as appropriate), and the pressure accumulating unit The hydraulic oil in (81) is supplied to the first water pump (51). The first water injection pump 51 pressurizes and injects water to the first water injection position P1 of the fuel distribution path by using the pressure of the supplied hydraulic oil. On the other hand, the control valve 55 is in a closed state for a period other than the water injection period of the downstream side water injection system 50 , and stops supply of hydraulic oil from the pressure accumulator 81 to the first water injection pump 51 . The timing of the opening/closing drive of the control valve 55 is controlled by the control unit 92 .

The upstream water injection system 60 is an example of the 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 supply 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 supply pump 61 receives water from the water supply pump 71 through the water supply pipe 72 or the like. The second water pump 61 pressurizes the received water to the internal distribution path 32 of the fuel injection valve 30 through the upstream water main pipe 62 . Thereby, the 2nd water injection pump 61 injects water into the 2nd water injection position P2 of the fuel flow path in this Embodiment 1. As shown in FIG.

The upstream side water supply pipe 62 is a pipe for flowing water injected by the second water injection pump 61 to the second water injection position P2 of the fuel distribution path. For example, as shown in FIG. 2 , one end of the upstream water feed pipe 62 is connected to a discharge port of the second water feed pump 61 . Moreover, the branching part 63 is formed in the middle part of the upstream main water pipe 62. As shown in FIG. The upstream main water pipe 62 is branched from this branching part 63 toward the other end into a plurality of branch pipes (three branch pipes 62a, 62b, 62c in the first embodiment). For example, among the branch pipes 62a, 62b, and 62c of the upstream water main pipe 62, the branch pipe 62a has one fuel injection valve ( 30) is connected to the internal circulation path 32 . The upstream side water supply pipe 62 communicates the internal flow path 32 of this 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 respectively connected to each other fuel injection valve 30 .

The check valve 64 is a valve for preventing the reverse flow of water by regulating the flow direction of water in the upstream water main pipe 62 in one direction. As shown in FIG. 2 , the check valve 64 is provided at an intermediate portion of the upstream water main pipe 62 (eg, a portion between the second water feed pump 61 and the branch portion 63 ). The check valve 64 enables the flow of water from the second water injection pump 61 side toward the fuel flow path side (in the present embodiment, the internal flow path 32 side of the fuel injection valve 30), Prevent this backflow.

The control valve 65 is a valve for controlling the supply of hydraulic oil from the pressure accumulator 81 to the second water injection pump 61 . Specifically, the control valve 65 is constituted by an electric on/off valve such as a solenoid valve, and as shown in FIG. 2 , the second water injection pump 61 and the pressure accumulator 81 are formed to communicate with each other. . The control valve 65 enters an open state during a period during which water from the second water injection pump 61 is injected into the fuel distribution path (hereinafter referred to as a water supply period of the upstream water injection system 60 as appropriate), and the pressure accumulating unit The hydraulic oil in (81) is supplied to the second water pump (61). The second water injection pump 61 pressurizes and injects water to the second water injection position P2 of the fuel distribution path by using the pressure of the supplied hydraulic oil. On the other hand, the control valve 65 enters a closed state for a period other than the water injection period of the upstream water injection system 60 , and stops supply of hydraulic oil from the pressure accumulator 81 to the second water injection pump 61 . The timing of the opening/closing drive of the control valve 65 is controlled by the control unit 92 .

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 containing branch pipes 42a-42c etc., 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 distribution path. In the first embodiment, the first water injection position P1 is, for example, as shown in FIG. 2 , a position near the injection port 31 in the internal flow path 32 of the fuel injection valve 30 , that is, It is a position upstream closest to the predetermined amount of fuel (fuel of the 1st fuel layer F1 shown in FIG. 3 mentioned later) which exists in the most downstream in the flow direction of a fuel in a fuel distribution path|route. The second water injection position P2 is a position on the upstream side in the fuel flow direction from the downstream side water injection system 50 in this fuel flow path. In the first embodiment, the second water injection position P2 is, for example, as shown in FIG. 2 , a position on the fuel injection pump 41 side among the internal circulation paths 32 of the fuel injection valve 30; That is, it is a position on the upstream side of the flow direction of a fuel rather than the 1st water injection position P1. In addition, in this Embodiment 1, the flow direction of fuel is the direction toward the injection port 31 of the fuel injection valve 30 via the fuel injection pipe 42 etc. from the fuel injection pump 41.

The water supply pump 71 is a pump for supplying the first water supply pump 51 and the second water injection pump 61 with water injected into the fuel distribution path described above. As shown in FIG. 2 , the water supply pump 71 is connected to the first water feed pump 51 and the second water feed pump 61 via a water feed pipe 72 or the like so that communication is possible. One end of the water supply pipe 72 is connected to a water supply pump 71 . Moreover, the water supply pipe 72 is branched into branch pipe 72a, 72b in the intermediate part. One branch pipe 72a of the water supply pipe 72 is connected to the first water supply pump 51 via a check valve 73a. The other branch pipe 72b of the water supply pipe 72 is connected to the second water supply 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 supply pump 51 through a branch pipe 72a of the water supply pipe 72 , and the water supply pipe 72 . It is supplied to the second water supply pump 61 through a branch pipe 72b or the like of The check valve 73a enables the flow of water from the water supply pump 71 side toward the first water supply pump 51 side, and prevents this reverse flow. The check valve 73b enables the flow of water from the water supply pump 71 side toward the second water supply pump 61 side, and prevents this reverse flow.

The pressure accumulator 81 accumulates the pressure of hydraulic oil for operating the fuel pressure feed system 40 , the downstream side injection system 50 , and the upstream side injection system 60 , respectively. The pressure accumulating unit 81 is a hollow structure having a pressure accumulating chamber capable of storing hydraulic oil therein, and as shown in FIG. 2 , is connected to a high pressure pump 82 through a pipe or the like so as to communicate with each other. The pressure accumulator 81 stores the hydraulic oil discharged (pressure-fed) from the high-pressure pump 82 in an internal pressure accumulation chamber, thereby accumulating the pressure of the hydraulic oil. Thus, the pressure of the hydraulic oil accumulated in the pressure accumulator 81 is adjusted by the discharge amount of the hydraulic oil from the high pressure pump 82 to the pressure accumulator 81 . The pressure of the hydraulic oil accumulated in the pressure accumulator 81 is determined by the operation of the fuel injection pump 41 of the fuel pressure delivery system 40 , the operation of the first injection pump 51 of the downstream injection system 50 , and the upstream operation of the fuel injection pump 41 . It is used for the operation of the second water pump 61 of the side water injection system 60 .

The detection part 91 detects the crank angle of the marine diesel engine 10 (refer FIG. 1). In the first embodiment, the detection unit 91 detects the rotation angle (that is, the crank angle) of the crank 4 which rotates with one cycle of reciprocating motion of the piston 15 in the cylinder 12 . do. At this time, the detection part 91 detects the rotation angle from the reference state of the crank 4 as a crank angle. In addition, as a reference state of the crank 4, the state of the crank 4 at the time of the piston 15 being located at bottom dead center or top dead center, etc. are mentioned, for example. The detection unit 91 detects a crank angle with passage of time, and transmits an electric signal indicating the detected crank angle to the control unit 92 each time.

The control unit 92 controls the layer injection timing of fuel and water, 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 . In the first embodiment, the fuel and water lamellar injection timing is the fuel and water stratified from the fuel injection valve 30 to the combustion chamber 17 (refer to FIG. 1) in the cylinder 12 of the marine diesel engine 10. It means the timing of spraying. The water injection timing of the downstream side water injection system 50 is the water injection start timing at which water injection is started by the first water injection pump 51 at the first water injection position P1 of the fuel distribution path, and the first water injection position P1. It means the timing of the end of the number of weeks to end the number of weeks. The water injection timing of the upstream water injection system 60 is the water injection start timing at which water injection is started by the second water injection pump 61 at the second water injection position P2 of the fuel flow path, and the second water injection position P2. It means the timing of the end of the number of weeks to end the number of weeks.

Specifically, the control unit 92 is constituted by a CPU for executing various programs, a memory, a sequencer, and the like. The control unit 92 receives the electric signal from the detection unit 91, and the control valve 45 of the fuel pressure delivery system 40 is opened at the timing at which the crank angle shown in the received electric signal becomes a predetermined rotation angle. ) to control the opening/closing 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 fuel and water from the fuel injection valve 30 to the combustion chamber 17 .

At this stratified injection timing, a required amount of fuel according to the engine load among the fuel pumped to the fuel distribution path by the fuel injection pump 41 and the first water injection position P1 in the fuel distribution path by the first water injection pump 51 ) and the water injected into the second water injection position P2 of the fuel distribution path by the second injection pump 61 by the pressure feeding action of the fuel injection pump 41 to the fuel injection valve 30 It is sprayed in a layered manner from the combustion chamber (17). Thereafter, this fuel flow path (in the present embodiment, the fuel flow path constituted by the fuel injection pipe 42 and the internal flow path 32 of the fuel injection valve 30) is filled with the fuel remaining without being injected. become a state

Moreover, the control part 92 WHEREIN: In the period other than the above-mentioned layered injection timing of fuel and water, the 1st water injection position P1 and the 2nd water injection position P2 of the fuel distribution path which are in a state filled with fuel are water-filled. The watering timing of the downstream side watering system 50 and the watering timing of the upstream side watering system 60 are controlled so as to inject each. At this time, the control part 92 is downstream 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 supply system 50 and the water supply period of the upstream side water supply system 60 may overlap. The water injection start timing by the first water injection pump 51 of the side water injection system 50 and the water injection start timing by the second water injection pump 61 of the upstream side water injection system 60 are controlled.

In the first embodiment, by injecting water into the first water injection position P1 and the second water injection position P2 of the fuel distribution path in the state of being filled with fuel, respectively, the layered liquid composed of these fuel and each layer of water is converted into fuel formed within the distribution channel. Fig. 3 is a diagram showing a configuration example of a layered liquid in a fuel flow path according to Embodiment 1 of the present invention. In FIG. 3 , the injection port side is the injection port 31 side of the fuel injection valve 30 , ie, the downstream side in the flow direction of the fuel in the fuel flow path. The fuel injection pump side is the fuel injection pump 41 side of the fuel pressure feeding system 40, ie, the flow direction upstream side of the fuel in a fuel flow path|route. As shown in FIG. 3 , the layered liquid 200 has a plurality of liquid layers arranged from the injection port side toward the fuel injection pump side, for example, a first liquid layer (L1) and a second liquid layer (L2). , a third liquid layer (L3), a fourth liquid layer (L4) and a fifth liquid layer (L5).

The first liquid layer L1 is the most downstream liquid layer among the layered liquids 200 . The layered liquid 200 includes a first fuel layer F1 as this first liquid layer L1. The first fuel layer F1 is the first fuel layer counted from the injection port side among the plurality of fuel layers (three in FIG. 3 ) included in the layered liquid 200 , and is present in the most downstream direction in the fuel flow direction. It consists of a certain amount of fuel.

The second liquid layer L2 is an upstream liquid layer closest to the first liquid layer L1 among the layered liquids 200 . The layered liquid 200 includes the first water injection layer W1 as the second liquid layer L2. The first water injection layer W1 is the first water injection layer counted from the injection port side among the plurality (two in FIG. 3 ) water injection layers included in the layered liquid 200 . This first water injection layer W1 is formed by injecting a required amount of water into the first water injection position P1 of the fuel distribution path by the first water injection pump 51 .

The third liquid layer L3 is an upstream liquid layer closest to the second liquid layer L2 among the layered liquids 200 . The layered liquid 200 includes the second fuel layer F2 as the third liquid layer L3. The second fuel layer F2 is a fuel layer of the second layer, counting from the injection port side, among the plurality of fuel layers included in the layered liquid 200 . This second fuel layer F2 consists of a fuel sandwiched between the layer of water injected into the first water injection position P1 of the fuel distribution path and the layer of water injected at the second water injection position P2.

The fourth liquid layer L4 is an upstream liquid layer closest to the third liquid layer L3 among the layered liquids 200 . The layered liquid 200 includes the second water injection layer W2 as the fourth liquid layer L4. The second water injection layer W2 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 . This second water injection layer W2 is formed by injecting a required amount of water into the second water injection position P2 of the fuel distribution path by the second water injection pump 61 .

The fifth liquid layer L5 is an uppermost liquid layer among the layered liquids 200 . The layered liquid 200 includes a third fuel layer F3 as this fifth liquid layer L5. The third fuel layer F3 is a fuel layer of the third layer, counting from the injection port side, among the plurality of fuel layers included in the layered liquid 200 . This 3rd fuel layer F3 consists of the fuel which exists in the upstream closest to the 2nd water injection layer W2.

Such a layered liquid 200 of fuel and water is injected into the combustion chamber 17 in the cylinder 12 from the injection port 31 of the fuel injection valve 30 for every reciprocating motion of the piston 15 in one cycle. At this time, the injection amount per one time of the fuel to the combustion chamber 17, ie, the fuel injection amount Qfa of the layered liquid 200, is the fuel amount Qf1 of the first fuel layer F1 and the fuel amount Qf2 of the second fuel layer F2, It is represented by the sum (= Qf1 + Qf2 + Qf3) of the fuel amount Qf3 of the 3rd fuel layer F3. The fuel injection amount Qfa of this layered liquid 200 increases with an increase in engine load, and decreases with a decrease.

In addition, the fuel amount between the water casting layers in the layered liquid 200 (in the present embodiment 1, the fuel amount Qf2 in the second fuel layer F2 sandwiched between the first water casting layer W1 and the second water casting layer W2) is , is adjusted by control of the respective watering start timings of the downstream side watering system 50 and the upstream side watering watering system 60 . At this time, it is preferable that the fuel amount (= Qf2) between water-casting layers is adjusted so that it may become a fixed ratio with respect to the fuel injection amount Qfa according to an engine load.

On the other hand, the water injection amount in one fuel injection to the combustion chamber 17, ie, the water injection amount Qwa of the layered liquid 200, is the water injection amount Qw1 of the first water injection layer W1 and the water injection amount Qw1 of the second water injection layer W2. It is expressed by the sum of the water quantity Qw2 (= Qw1 + Qw2). The water injection amount Qwa of this layered liquid 200 is adjusted to a required amount according to the engine load so as to achieve reduction of NOx and improvement of fuel economy. 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 water supply amount by the downstream side water supply system 50 and the upstream side water injection system 60 It is preferable that the ratio of the water supply amount by is constant.

Next, the control of the water injection timing for adjusting the fuel amount between water injection layers in Embodiment 1 of this invention is demonstrated. Fig. 4 is a diagram for explaining control of watering timing in Embodiment 1 of the present invention. In FIG. 4 , the valve control signal S1 performs an opening/closing actuation of the control valve 55 of the first water injection pump 51 for injecting water into the first water injection position P1 (see FIG. 2 ) of the fuel flow path. It is a control signal for instructing. The valve control signal S2 is a control signal for instructing an opening/closing drive to 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. am. It is a figure for demonstrating adjustment of the fuel amount between water-casting layers in Embodiment 1 of this invention. In FIG. 5 , a fuel column 201 is a columnar fuel remaining in the fuel flow path in the first embodiment.

In the first embodiment, the control unit 92 transmits, for example, the valve control signals S1 and S2 shown in FIG. 4 to the control valves 55 and 65, respectively, and opens and closes the control valves 55 and 65 respectively. control the timing of Thereby, the control part 92 controls the watering timing of the downstream watering system 50 (1st floor watering) so that the watering period of the downstream watering system 50 and at least a part of the watering period of the upstream watering system 60 may overlap. timing) and the watering timing of the upstream side watering system 60 (second layer watering timing) are controlled according to the engine load. At this time, as a preferable example, the control unit 92 controls the amount of fuel between the layer of water injected by the downstream side injection system 50 and the layer of water injected by the upstream side injection system 60 , the fuel injection amount according to the engine load, as a preferable example. Each water injection start timing of the downstream side water injection system 50 and the upstream side water supply system 60 is controlled so that it may become a fixed ratio with respect to Qfa.

Specifically, the control unit 92 calculates the waiting time ΔT for water injection according to the engine load. The waiting time ΔT is the operation of the filling piston of the water supply system that starts watering from the start of the operation of the filling piston of the watering system that started watering before, among the downstream side watering system 50 and the upstream side watering system 60 , after which watering is started. time until start. This waiting time ΔT is, for example, the engine rotation speed (engine rotation speed per unit time) and the fuel injection amount (fuel injection amount per one time) at the time of engine load required for the marine diesel engine 10 according to the navigation condition of the ship; It is expressed as the following formula (1) by the function f(x, y, z) including the water injection amount (the amount injected into the fuel for one injection time) as independent variables x, y, z, respectively. For example, the control unit 92 calculates the waiting time ΔT so that the waiting time ΔT increases with an increase in the engine load, and the waiting time ΔT decreases with a decrease in the engine load.

Waiting time ΔT = f(x, y, z) ... (1)

In addition, these engine rotation speed, fuel injection amount, and water injection amount can be derived based on the results of simulations, experiments, etc. of the marine diesel engine 10. In the control part 92, this formula (1) is preset.

The control unit 92 calculates, for example, the waiting time ΔT1 of the downstream side water supply system 50 as the above-described waiting time ΔT. The waiting time ΔT1 of the downstream side water supply system 50 is the time from when the upstream side water injection system 60 starts watering until the downstream side water injection system 50 starts watering, that is, the second water injection pump ( It is the time from when 61) starts operation until the first water pump 51 starts operation. The control unit 92 delays the watering start timing of the downstream side watering system 50 from the watering start timing of the upstream watering watering system 60 by this calculated waiting time ΔT1 .

Specifically, the control unit 92 acquires the crank angle indicated in 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 the timing T1 when the crank angle detection value becomes the crank angle R1. Thereby, the control part 92 causes the 2nd water injection pump 61 of the upstream water injection system 60 to start operating. 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 watering start timing of the upstream watering system 60 . At this timing T1, as shown in FIG. 5, injection|pouring of the water 202 with respect to the 2nd water injection position P2 among the fuel columns 201 in a fuel distribution path|route is started.

In addition, in timing T0 within the period from the completion of the last fuel injection to the said watering start timing (timing T1), as shown in FIG. 5, watering with respect to the fuel column 201 is not started. The fuel amount of the fuel column 201 at this time corresponds to the above-mentioned fuel injection amount Qfa.

Next, the control unit 92 starts watering by the downstream watering system 50 at a timing delayed from the watering start timing of the upstream watering watering system 60 by the waiting time ΔT1 calculated as described above. . Specifically, the control unit 92 converts the standby time ΔT1 of the downstream side water supply system 50 into a change amount ΔR of the crank angle based on the engine rotation speed according to the engine load and the elapsed time of the engine rotation. The control unit 92 calculates the crank angle R2 by adding the obtained change amount ΔR of the crank angle and the crank angle R1 at the watering start timing (timing T1) of the upstream watering system 60 . As shown in FIG. 4 , the control unit 92 instructs the control valve 55 of the downstream side water injection system 50 to open at the timing T2 when the crank angle detection value becomes the crank angle R2 . Thereby, the control part 92 causes the 1st water injection pump 51 of the downstream water supply system 50 to start operating while continuing the operation of the 2nd water injection pump 61 of the upstream water injection system 60 . Based on this control, the first water injection pump 51 starts water injection to the first water injection position P1 of the fuel distribution path. That is, the timing T2 of the crank angle R2 is the watering start timing of the downstream watering system 50 . On the other hand, the second water injection pump 61 continuously pumps water to the second water injection position P2 of the fuel distribution path. At this timing T2, as shown in FIG. 5, while injection of the water 202 to the 2nd water injection position P2 is continuously performed among the fuel columns 201 in the fuel distribution path, the 1st water injection position P1 ) injection of water 203 into

Thereafter, the second water injection pump 61 continuously pumps water to the second water injection position P2 of the fuel flow path for a period until the control valve 65 is driven to close. In parallel with this, the first water injection pump 51 continuously pumps water to the first water injection position P1 of the fuel flow path during the period until the control valve 55 is driven to close.

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. , the injection of the water 203 at the first water injection position P1 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 converted into the water 202 at the second water injection position P2. ) and is pushed back to the upstream side in the distribution 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 decrease.

Then, at the timing T3 of the crank angle R3, the water 202 of the 2nd water injection position P2 is inject|poured until the width direction (the width direction of a fuel distribution path|route) whole of the fuel column 201 spreads. At this time, as shown in FIG. 5, the water 202 of the 2nd water injection position P2 makes the fuel column 201 a downstream fuel 201a located downstream from the 2nd water injection position P2. and the most upstream fuel 201b located upstream from the second water injection position P2. In this step, even if the fuel between the first water injection position P1 and the second water injection position P2 is injected with the water 203 at the first water injection position P1, the second water injection position P2 There is no case of being pushed back upstream in the flow direction beyond the water 202 of the . Thereby, adjustment of the fuel amount between the 1st water injection position P1 and the 2nd water injection position P2 is complete|finished, and the fuel amount of the downstream fuel 201a is determined.

Then, as shown in FIG. 4, the control part 92 instructs a closing drive with respect to the control valve 65 of the upstream water injection system 60 at timing T4 when the crank angle detection value became the crank angle R4. Thereby, the control part 92 stops the operation of the 2nd water injection pump 61 of the upstream water supply system 60, while continuing the operation|movement of the 1st water injection pump 51 of the downstream water supply system 50. As shown in FIG. Based on this control, the second water injection pump 61 ends the water injection with respect to the second water injection position P2 of the fuel flow path. That is, the timing T4 of the crank angle R4 is the watering end timing of the upstream watering system 60 . On the other hand, the first water injection pump 51 continuously pumps water to the first water injection position P1 of the fuel distribution path.

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 is transferred to the fuel column 201 . The water 203 of the 1st water injection position P1 is continuously injected while further injecting from the state which spread across the width direction of . In this step, 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.

Moreover, as shown in FIG. 5, at the timing T4 of the crank angle R4, it is the state in which the water 202 of the 2nd water injection position P2 was inject|poured by the required amount. On the other hand, the water 203 of the 1st water injection position P1 is in the injected state until it spreads over the width direction whole area of the fuel column 201. The water 203 in this state is the downstream fuel 201a of the fuel column 201, the most downstream fuel 201c located downstream from the 1st water injection position P1, and the 2nd water injection position P2 . Thereby, the fuel amount of the fuel between the main water layers 201d, that is, the fuel amount (= Qf2) between the main water layers, and the fuel amount of the most downstream fuel 201c are determined. In addition, the timing at which the water 203 of the 1st water injection position P1 is injected until it spreads across the width direction of the fuel column 201 is the timing at which the required amount of the water 202 of the 2nd water injection position P2 was injected It may be the same as T4, the previous timing may be sufficient, and the later timing may be sufficient.

Then, as shown in FIG. 4, the control part 92 instructs a closing drive with respect to the control valve 55 of the downstream side water supply system 50 at timing T5 when the crank angle detection value became the crank angle R5. Thereby, the control part 92 stops the 1st water injection pump 51 of the downstream water injection system 50 from operation. Based on this control, the first water injection pump 51 ends the water injection to the first water injection position P1 of the fuel distribution path. That is, the timing T5 of the crank angle R5 is the watering completion timing of the downstream watering system 50 .

For example, as shown in FIG. 5 , in 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 is 201), it is being injected more from the state that it spreads across the width direction. On the other hand, the injection of the water 202 at the second water injection position P2 has already been completed at the above-described timing T4. In this step, the injection of the water 203 at the first water injection position P1 is performed in the same manner as in the period from the timing T3 to the timing T4 described above, and continues until the injection amount of the water 203 becomes the required amount. do. And at the timing T5 of the crank angle R5, each injection|pouring of the 1st water injection position P1 and the 2nd water injection position P2 is complete|finished. As a result, the layered liquid 200 which consists of the 1st fuel layer F1, the 1st water injection layer W1, the 2nd fuel layer F2, the 2nd water injection layer W2, and the 3rd fuel layer F3 is , formed within the fuel distribution path.

Here, in this Embodiment 1, the watering period of the upstream watering 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 watering period of the upstream watering system 60 is a period of only the time obtained by adding the waiting time ΔT1, the time ΔT2, and the time ΔT3 shown in FIG. 4 . This watering period is determined by the time required to inject the required amount of water 202 into the second watering position P2 shown in FIG. 5 . That is, the crank angle R4 corresponding to the watering end timing (timing T4) of the upstream watering system 60 is the crank angle R1 corresponding to the watering start timing, and the time required for injection of the required amount of water 202. is derived based on

In addition, the watering period of the downstream watering system 50 is a period from the timing T2 of the crank angle R2 to the timing T5 of the crank angle R5. This watering period is determined by the time required to inject the required amount of water 203 into the first watering position P1 shown in FIG. 5 . That is, the crank angle R5 corresponding to the watering end timing (timing T5) of the downstream side watering system 50 is the crank angle R2 corresponding to the watering start timing, and the time required for injection of the required amount of water 203 . is derived based on

In this Embodiment 1, as shown in FIG. 4, the period in which the watering period of the upstream watering system 60 and the watering period of the downstream watering system 50 overlap is time from crank angle R2 to crank angle R4 It corresponds to ΔT4. This time ΔT4 is a time ΔT2 adjusted (reduction adjustment) so that the fuel amount between the watering layers is decreased by the watering of the downstream side watering system 50, and the upstream side watering system 60 after the adjustment of the fuel amount between the watering layers is completed. It is the time plus the time ΔT3 until the end of the week of . The watering start timing of the downstream side water injection system 50 is the water injection start timing of the upstream side water injection system 60 such that the time ΔT2 decreases with an increase in the engine load and the time ΔT2 increases with the decrease of the engine load It is controlled with a timing delayed by the waiting time ΔT1. That is, this waiting time ΔT1 increases with an increase in the engine load, and decreases with a decrease in the engine load. In addition, when this waiting time ΔT1 is a value of 0 (ΔT1 = 0), the watering start timing of the downstream watering system 50 is controlled to be the same timing as the watering start timing of the upstream watering watering system 60 .

6 is a diagram showing an example of the injection amount of the layered liquid according to the engine load in the first embodiment of the present invention. The injection quantity shown in FIG. 6 is the injection quantity per one time of the layered liquid 200 (refer FIG. 3) injected from the one fuel injection valve 30 to the combustion chamber 17 in the cylinder 12. As shown in FIG. The injection quantity of this layered liquid 200 is the sum of the fuel injection quantity Qfa according to the engine load, and each injection quantity Qw1, Qw2 of the 1st water injection layer W1 and the 2nd injection layer W2 (= Qfa + Qw1 + Qw2) is represented by

In the first embodiment, the injection amount of the layered liquid 200 is set by controlling each watering start timing of the downstream side watering system 50 and the upstream side watering system 60 described above. For example, as shown in FIG. 6 , the injection amount of the layered liquid 200 increases with an increase in the engine load, and decreases with a decrease in the engine load. Among such layered liquids 200, the amount of fuel in the second fuel layer F2 sandwiched between the first and second pouring layers W1 and W2 (that is, the amount of fuel between the pouring layers) is appropriate depending on the engine load. adjusted to the quantity. Preferably, in the engine load range (55% or more and 100% or less in Fig. 6) in which the layered liquid 200 having a fuel layer between the water-casting layers is formed in the fuel distribution path, the fuel amount between the water-casting layers is the engine load It is adjusted (optimized) so that it becomes a constant ratio with respect to the fuel injection amount Qfa that increases or decreases according to 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.

As mentioned above, in the fuel injection apparatus 100 which concerns on Embodiment 1 of this invention, in the fuel injection device 100 which concerns on Embodiment 1 of this invention, the fuel injection valve which injects fuel and water into the combustion chamber 17 in the cylinder 12 of the marine diesel engine 10 in layers. (30) and the fuel injection pump 41 which pumps fuel to the fuel injection valve 30 via piping, and the fuel distribution path|route from the fuel injection pump 41 to the injection port 31 of the fuel injection valve 30 a downstream side water injection system 50 for injecting water into the first water injection position P1 of An upstream water injection system (60) for injecting water is formed, and a water supply period of the downstream side water supply system (50) overlaps with at least a part of the water supply period of the upstream side water supply system (60), so that the downstream side water supply system (50) is formed. ) and each water injection start timing of the upstream side water injection system 60 are controlled according to the engine load. At this time, the waiting time ΔT1 of the downstream water injection system 50 from when the upstream water injection system 60 starts watering until the downstream side water injection system 50 starts water injection is calculated according to the engine load, By the calculated waiting time ΔT1 , the watering start timing of the downstream watering system 50 is delayed from the watering start timing of the upstream watering watering system 60 .

With the above configuration, within the overlapping period of the watering period of the downstream side watering system 50 and the watering period of the upstream side watering system 60, the watering layer by the downstream side watering system 50 and the upstream side watering system 60 ) can be adjusted so that the ratio of the fuel amount between the water formation layers to the fuel injection amount Qfa according to the engine load does not become too large or too small. For this reason, when injecting fuel and water in layers from the fuel injection valve 30, the fuel amount between water injection layers can be adjusted suitably according to an engine load. As a result, generation|occurrence|production of undesirable combustion conditions, such as combustion defect of the marine diesel engine 10 which may occur when fuel and water are injected in layers, can be suppressed so that NOx in exhaust gas can be reduced.

Further, in the fuel injection device 100 according to the first embodiment of the present invention, the downstream side water injection system 50 and the upstream side are such that the amount of fuel between the water injection layers described above becomes a constant ratio with respect to the fuel injection amount Qfa according to the engine load. Each water injection start timing of the water injection system 60 is controlled according to the engine load. For this reason, when injecting fuel and water in a layered manner from the fuel injection valve 30, the fuel amount between water injection layers can be adjusted to the optimal fuel amount for every engine load. As a result, NOx in exhaust gas can be reduced most effectively.

Moreover, in the fuel injection device 100 which concerns on Embodiment 1 of this invention, the ratio of the water injection quantity Qw1 by the downstream side water injection system 50 and the water injection quantity Qw2 by the upstream side water injection system 60 is made constant. . For this reason, when injecting fuel and water in layers from the fuel injection valve 30, the quantity of water supply layer injected subsequent to a fuel layer can be optimized for every engine load. As a result, while preventing misfire by water injection after combustion of fuel and ensuring stable operation of the marine diesel engine 10, NOx in exhaust gas can be reduced most effectively.

(Embodiment 2)

Next, Embodiment 2 of this invention is demonstrated. In Embodiment 1 mentioned above, the downstream side water injection system may 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 only by the waiting time calculated according to the engine load. Although each watering start timing of 50 and the upstream watering system 60 was controlled, in this Embodiment 2, the watering start timing of the upstream watering system 60 is set on the downstream side by the waiting time calculated according to the engine load. Each watering start timing of the downstream watering system 50 and the upstream watering system 60 is controlled so as to delay the watering start timing of the watering system 50 .

Fig. 7 is a schematic diagram showing a configuration example of a fuel injection device according to a second embodiment of the present invention. As shown in FIG. 7 , this fuel injection device 110 includes a control unit 112 instead of the control unit 92 of the fuel injection device 100 according to the first embodiment described above. Other structures are the same as those of the first embodiment, and the same reference numerals are assigned to the same constituent parts. Moreover, although not shown in particular, the marine diesel engine to which the fuel injection device 110 which concerns on this Embodiment 2 was applied other than the structure provided with the said control part 112, the marine diesel engine in Embodiment 1 mentioned above. It is configured in the same way as (10).

The control unit 112 is constituted by a CPU for executing various programs, a memory, a sequencer, and the like. The control unit 112 supplies water to the first water injection position P1 and the second water injection position P2 of the fuel distribution path that are in a state filled with fuel in a period other than the above-described fuel and water layered injection timing, respectively. 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 in accordance with the engine load so as to inject. At this time, in order to overlap at least a part of the irrigation period of the downstream irrigation system 50 and the irrigation period of the upstream irrigation system 60, the control unit 112 controls the upstream by the waiting time calculated according to the engine load. The water injection start timing by the first water injection pump 51 of the downstream side water supply system 50 and the upstream side so as to delay the water injection start timing of the side water injection system 60 from the water injection start timing of the downstream side water injection system 50 The water injection start timing by the second water injection pump 61 of the water injection system 60 is controlled. Moreover, the control part 112 controls the layered injection timing of 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.

Next, the control of the water injection timing for adjusting the fuel amount between water injection layers in Embodiment 2 of this invention is demonstrated. Fig. 8 is a diagram for explaining control of watering timing in Embodiment 2 of the present invention. It is a figure for demonstrating adjustment of the fuel amount between water-casting layers in Embodiment 2 of this invention.

In the second embodiment, the control unit 112 transmits, for example, the valve control signals S1 and S2 shown in FIG. 8 to the control valves 55 and 65, respectively, and drives the opening and closing of the control valves 55 and 65, respectively. control the timing of In this way, the control unit 112 controls the watering timing of the downstream watering system 50 (first floor watering) so that at least a part of the watering period of the downstream watering system 50 and the watering period of the upstream watering system 60 overlap. timing) and the watering timing of the upstream side watering system 60 (second layer watering timing) are controlled according to the engine load. At this time, as a preferable example, the control unit 112 controls the amount of fuel between the layer of water injected by the downstream side injection system 50 and the layer of water injected by the upstream side injection system 60 according to the fuel injection quantity Qfa according to the engine load, as a preferable example. Each watering start timing of the downstream side water injection system 50 and the upstream side water injection system 60 is controlled so that it may become a constant ratio with respect to .

In detail, the control unit 112 sets, for example, the waiting time ΔT11 of the upstream water supply system 60 as the waiting time ΔT based on the equation (1) in which the above-mentioned equation (1) is preset. Calculate. The waiting time ΔT11 of the upstream water injection system 60 is the time from when the downstream water injection system 50 starts watering until the upstream water injection system 60 starts watering, that is, the first water injection pump ( It is the time from when 51) starts operation until the second water pump 61 starts operation. The control unit 112 delays the watering start timing of the upstream watering system 60 from the watering start timing of the downstream watering watering system 50 by this calculated waiting time ΔT11 .

Specifically, the control part 112 acquires the crank angle detection value by the detection part 91, and, as shown in FIG. 8, at the timing T11 when the crank angle detection value became the crank angle R11, An open drive is instructed to the control valve 55 . Thereby, the control part 112 causes the 1st water injection pump 51 of the downstream water injection system 50 to start operating. Based on this control, the first water injection pump 51 starts water injection to the first water injection position P1 of the fuel distribution path. That is, the timing T11 of the crank angle R11 is the watering start timing of the downstream watering system 50 . At this timing T11, as shown in FIG. 9, injection|pouring of the water 203 with respect to the 1st water injection position P1 among the fuel columns 201 in a fuel distribution path|route is started. With the start of injection of the water 203 to the first water injection position P1, the fuel between the first water injection position P1 and the second water injection position P2 exceeds the second water injection position P2. In the direction of distribution, it begins to recede to the upstream side. Thereby, the fuel amount between the 1st water injection position P1 and the 2nd water injection position P2 starts to be adjusted so that it may decrease.

In addition, in timing T0 within the period from the completion of the last fuel injection to the said watering start timing (timing T11), as shown in FIG. 9, watering with respect to the fuel column 201 is not started. The fuel amount of the fuel column 201 at this time corresponds to the above-mentioned fuel injection amount Qfa.

Next, the control unit 112 starts watering by the upstream watering system 60 at a timing delayed from the watering start timing of the downstream watering system 50 by the waiting time ΔT11 calculated as described above. . Specifically, the control unit 112 converts the standby time ΔT11 of the upstream side water supply system 60 into a change amount ΔR of the crank angle based on the engine rotation speed according 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 watering start timing (timing T11) of the downstream watering 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 the timing T12 when the crank angle detection value becomes the crank angle R12 . Thereby, the control part 112 causes the 2nd water injection pump 61 of the upstream injection system 60 to start operating while continuing the operation of the first injection pump 51 of the downstream 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 watering start timing of the upstream watering system 60 . On the other hand, the first water injection pump 51 continuously pumps water to the first water injection position P1 of the fuel distribution path. At this timing T12, as shown in FIG. 9, while injection of the water 203 with respect to the 1st water injection position P1 among the fuel columns 201 in the fuel distribution path is continuously performed, the 2nd water injection position P2 ) injection of water 202 into

Thereafter, the first water injection pump 51 continuously pumps water to the first water injection position P1 of the fuel flow path for a period until the control valve 55 is driven to close. In parallel with this, the second water injection pump 61 continuously pumps water to the second water injection position P2 of the fuel distribution path during the period until the control valve 65 is driven to close.

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 the water 203 at the first water injection position P1 proceeds. In addition, during the period of time ΔTa from the crank angle R12 to the crank angle Ra (> R12) during this period, while the water 203 at the first watering position P1 is injected, the water 203 at the second watering position P2 ) of the water 202 is injected. 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 transferred to the second water injection position P2 or the water 202 ) and is pushed back to the upstream side in the distribution direction. Thereby, the fuel amount between the first water injection position P1 and the second water injection position P2 is adjusted to decrease during the period of time ΔT13.

In addition, during the period of this 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 the water 203 of the 1st water injection position P1 shows in FIG. 9, the most downstream fuel 201c located the fuel column 201 downstream from the 1st water injection position P1. and the upstream side fuel 201e located on the upstream side from the first water injection position P1. In this step, 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 spread across the width direction of the fuel column 201, and the second 2 Water 202 at the water injection position P2 is continuously injected. In this step, the injection of the water 203 at the first water injection position P1 causes the fuel between the first water injection position P1 and the second water injection position P2 to flow in the flow direction from the second water injection position P2. It is carried out while being pushed back upstream.

On the other hand, at the timing of crank angle Ra, it is inject|poured until the water 202 of the 2nd water injection position P2 spreads across the width direction of the fuel column 201 whole. At this time, the water 202 at the second water injection position P2 is the upstream fuel 201e in the fuel column 201 with the most upstream fuel 201b located upstream from the second water injection position P2 and , divided into a water injection interlayer fuel 201d sandwiched between the water 202 at the second water injection position P2 and the water 203 at the first water injection position P1. In this step, even if the fuel between the first water injection position P1 and the second water injection position P2 is injected with the water 203 at the first water injection position P1, the second water injection position P2 There is no case of being pushed back upstream in the flow direction beyond the water 202 of the . Thereby, adjustment of the fuel amount between the 1st water injection position P1 and the 2nd water injection position P2 is complete|finished, and the fuel amount of the fuel 201d between water injection layers, ie, the fuel amount between water injection layers (= Qf2) is determined.

In addition, the timing of this crank angle Ra may be the same as the timing T14 at which the required amount of water 202 at the 2nd water injection position P2 is inject|poured, the timing before or after may be sufficient as it. Which of these timings will be the timing of the crank angle Ra is determined by the waiting time ΔT11 according to the engine load. In FIG. 9, the case where the timing of crank angle Ra is the same timing as timing T14 of crank angle R14 is shown.

Moreover, as shown in FIG. 8, the control part 112 instructs a closing drive with respect to the control valve 55 of the downstream water supply system 50 at timing T14 when the crank angle detection value became the crank angle R14. Thereby, the control part 112 stops the operation of the 1st water injection pump 51 of the downstream water supply system 50, while continuing the operation|movement of the 2nd water injection pump 61 of the upstream water injection system 60. As shown in FIG. Based on this control, the first water injection pump 51 ends the water injection to the first water injection position P1 of the fuel distribution path. That is, the timing T14 of the crank angle R14 is the watering end timing of the downstream watering system 50 . On the other hand, the second water injection pump 61 continuously pumps water to the second water injection position P2 of the fuel distribution path. As shown in FIG. 9 , at the timing T14 of the crank angle R14, the water 203 at the first water injection position P1 is in a state in which the required amount is injected.

Thereafter, as shown in FIG. 8 , the control unit 112 instructs the control valve 65 of the upstream water injection system 60 to close-drive at timing T15 when the crank angle detection value becomes the crank angle R15. Thereby, the control part 112 stops the 2nd water injection pump 61 of the upstream water injection system 60 from operation. Based on this control, the second water injection pump 61 ends the water injection with respect to the second water injection position P2 of the fuel flow path. That is, the timing T15 of the crank angle R15 is the watering completion timing of the upstream watering system 60 .

For example, as shown in FIG. 9 , in 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 is 201) is further injected from the state spread across the width direction. On the other hand, the injection of the water 203 at the first water injection position P1 has already been completed at the above-described timing T14. In this step, the injection of the water 202 at the second water injection position P2 is performed in the same manner as in the period from the timing T13 to the timing T14 described above, and continues until the injection amount of the water 202 becomes the required amount. do. And at the timing T15 of the crank angle R15, each injection of the 2nd water injection position P2 and the 1st water injection position P1 is complete|finished. As a result, the layered liquid 200 which consists of the 1st fuel layer F1, the 1st water injection layer W1, the 2nd fuel layer F2, the 2nd water injection layer W2, and the 3rd fuel layer F3 is , is formed within the fuel distribution path.

Here, in the present Embodiment 2, the watering period of the downstream side watering 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 watering period of the downstream watering system 50 is a period only for the time which added waiting time (DELTA)T11 and time (DELTA)T12 shown in FIG. This watering period is determined by the time required to inject the required amount of water 203 into the first watering position P1 shown in FIG. 9 . That is, the crank angle R14 corresponding to the watering end timing (timing T14) of the downstream side watering system 50 is the crank angle R11 corresponding to the watering start timing, and the time required for injection of the required amount of water 203 is derived based on

Moreover, the watering period of the upstream watering system 60 is a period from the timing T12 of the crank angle R12 to the timing T15 of the crank angle R15. This watering period is determined by the time taken to inject the required amount of water 202 into the second watering position P2 shown in FIG. 9 . That is, the crank angle R15 corresponding to the watering end timing (timing T15) of the upstream watering system 60 is the crank angle R12 corresponding to the watering start timing, and the time required for injection of the required amount of water 202. is derived based on

In this Embodiment 2, as shown in FIG. 8, the period in which the watering period of the downstream side watering system 50 and the watering period of the upstream watering system 60 overlap is time from crank angle R12 to crank angle R14. It corresponds to ΔT12. During this period, the period of time ΔTa from the crank angle R12 to the crank angle Ra is a part of the period in which the amount of fuel between the watering layers is reduced and adjusted by the watering of the downstream watering system 50 . In addition, the period of the waiting time ΔT11 from the crank angle R11 to the crank angle R12 is the remainder of the period during which the amount of fuel between the water pouring layers is reduced and adjusted. That is, the period of time ?T13, which is the sum of the waiting time ?T11 and the time ?Ta, is the entire period during which the amount of fuel between the water-casting layers is reduced and adjusted. The watering start timing of the upstream side water injection system 60 is such that the time ΔT13 decreases with an increase in the engine load and the time ΔT13 increases with the decrease of the engine load. It is controlled with a timing delayed by the waiting time ΔT11. That is, this waiting time ΔT11 decreases with an increase in the engine load, and increases with a decrease in the engine load. In addition, when this waiting time ΔT11 is a zero value (ΔT11=0), the watering start timing of the upstream watering system 60 is controlled to be the same timing as the watering start timing of the downstream watering system 50 .

As described above, in the fuel injection device 110 according to the second embodiment of the present invention, at least a part of the watering period of the downstream side water injection system 50 and the watering period of the upstream side water injection system 60 overlap. For this purpose, the waiting time ΔT11 of the upstream water injection system 60 from when the downstream water supply system 50 starts watering until the upstream side water injection system 60 starts water injection is calculated according to the engine load. By the waiting time ΔT11, the downstream side watering system 50 and the upstream side watering system 60 delay the watering start timing of the upstream watering system 60 from the watering start timing of the downstream side watering system 50 by the waiting time ΔT11. Each watering start timing is controlled, and the rest are the same as in the first embodiment. For this reason, while enjoying the same effects as in the case of Embodiment 1 mentioned above, the time during which the amount of fuel between the watering layers can be reduced and adjusted by the watering of the downstream watering system 50 is reduced by the upstream watering system (60) can be adjusted more extensively compared to the case of first pouring water, and thereby, it is possible to simply optimize the ratio of the fuel amount between the water layers to the fuel injection amount according to the engine load.

In addition, in the above-described embodiments 1 and 2, when controlling each watering start timing of the downstream side watering system 50 and the upstream side watering system 60, the waiting time for watering start calculated according to the engine load (example For example, the crank angle is calculated from ΔT1 or ΔT11), and the timing at which the obtained crank angle coincides with the crank angle detection value by the detection unit 91 is set as the watering start timing following the previous watering start timing. The present invention is not limited thereto. For example, each watering start timing of the downstream side water injection system 50 and the upstream side water injection system 60 is controlled according to the elapsed time (that is, the time axis) at the time of engine rotation of a marine diesel engine, and from the previous water injection start timing The timing at which the elapsed time reached the waiting time according to the engine load may be set as the subsequent watering start timing.

Moreover, in Embodiment 1 and 2 mentioned above, although the fuel injection apparatus provided with the three fuel injection valves 30 was illustrated, this invention is not limited to this. For example, in this invention, the number of arrangement|positioning of the fuel injection valve 30 is not limited to three, One may be sufficient, and plural (two or more) may be sufficient as it.

Moreover, this invention is not limited by Embodiment 1, 2 mentioned above, What was comprised combining each component mentioned above suitably is also included in this invention. In addition, based on the above-mentioned Embodiment 1 and 2, other embodiment, Example, operation technique, etc. which are made by those skilled in the art etc. are all included in the scope of the present invention.

Industrial Applicability

As described above, the fuel injection device according to the present invention is useful for injection of fuel and water to a combustion chamber in a cylinder of a marine diesel engine, and is particularly suitable for a fuel injection device capable of adjusting the amount of fuel between the main water layers according to the engine load. .

1: main board
2: Crankshaft
3: bearing
4: crank
5: Furniture
6: connecting rod
7: guide plate
8 : cross head
9: cross head 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 actuation device
20: exhaust pipe
21 : tie bolt
22: nut
30: fuel injection valve
31: nozzle
32, 33: internal distribution channels
34a, 34b: check valve
40: fuel pressure delivery system
41 fuel injection pump
42: fuel injection pipe
42a, 42b, 42c: branch pipe
43: branch
45: control valve
50: downstream side water supply system
51: first water pump
52: downstream side water pipe
52a, 52b, 52c: branch pipe
53: branch
54: check valve
55: control valve
60: upstream side water supply system
61: second water pump
62: upstream side water pipe
62a, 62b, 62c: branch pipe
63: branch
64: check valve
65: control valve
71: water supply pump
72: water pipe
72a, 72b: branch pipe
73a, 73b: check valve
81: pressure accumulator
82: high pressure pump
91: detection unit
92, 112: control unit
100, 110: fuel injection device
200: layered liquid
201 : fuel column
201a: downstream fuel
201b: top-class fuel
201c: downstream fuel
201d: fuel between the main water layers
201e: Upstream fuel
202, 203: water
F1: first fuel layer
F2: second fuel layer
F3: 3rd fuel layer
L1: first liquid layer
L2: second liquid layer
L3: third liquid layer
L4: fourth liquid layer
L5: fifth liquid layer
P1: 1st watering position
P2: 2nd watering position
S1, S2: valve control signal
W1: first main aqueous layer
W2: second main aqueous layer

Claims (7)

A fuel injection valve formed in a cylinder of a marine diesel engine,
a fuel injection pump for pressurizing fuel to the fuel injection valve through a pipe;
a first water injection system for injecting water into a predetermined position of a fuel distribution path from the fuel injection pump to the injection port of the fuel injection valve;
a second water injection system for injecting water into a position on the upstream side in the fuel distribution direction from the first water injection system in the fuel distribution path;
Each watering start timing of the first watering system and the second watering system is controlled according to the load of the marine diesel engine so that at least a part of the watering period of the first watering system and the watering period of the second watering system overlap and a control unit that
According to the load of the said marine diesel engine, the said control part is the said 1st water injection system and the said other water injection system until the other water supply system starts watering after one water main water system starts watering, according to the load of the said second water supply system. calculating the waiting time of the system, and delaying the watering start timing of the other watering line from the watering start timing of the one watering line by the calculated waiting time;
The fuel injection valve is configured to distribute the fuel pumped by the fuel injection pump, water injected by the first injection system, and water injected by the second injection system from the injection port to the combustion chamber in the cylinder in a layered manner. A fuel injection device, characterized in that for injection. The method of claim 1,
The control unit may include: the first water injection system and The fuel injection device according to claim 1, wherein each water injection start timing of the second water injection system is controlled. The method of claim 1,
The control unit calculates, according to the load of the marine diesel engine, a waiting time of the first water injection system from when the second water injection system starts watering until the first water injection system starts watering, and calculates The fuel injection device 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 increased waiting time. 3. The method of claim 2,
The control unit calculates, according to the load of the marine diesel engine, a waiting time of the first water injection system from when the second water injection system starts watering until the first water injection system starts watering, and calculates The fuel injection device 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 increased waiting time. The method of claim 1,
According to the load of the marine diesel engine, the control unit calculates a waiting time of the second water injection system from when the first water injection system starts watering until the second water injection system starts watering, and calculates The fuel injection device 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 increased waiting time. 3. The method of claim 2,
According to the load of the marine diesel engine, the control unit calculates a waiting time of the second water injection system from when the first water injection system starts watering until the second water injection system starts watering, and calculates The fuel injection device 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 increased waiting time. 7. The method according to any one of claims 1 to 6,
The fuel injection device, characterized in that the ratio of the water injection amount by the first water injection system and the water injection amount by the second water system is constant.

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