JP2024030317A - fuel injection system - Google Patents

Abstract

[Problem] In a fuel injection system equipped with an injection pump that injects alternative fuel such as ammonia into fossil fuel, even if there are individual differences in injecting alternative fuel such as ammonia whose viscosity is lower than water, multiple Provided is a fuel injection system including an injection pump capable of injecting the same amount of alternative fuel into two fuel injection valves. SOLUTION: In S3, an average discharge amount is calculated. Then, in S4, the first infusion pump part 51a, the second infusion pump part 51b, and the third infusion pump part 51c are lifted so that the discharge amount of each infusion pump part 51a, 51b, and 51c becomes the average discharge amount. Control quantity. [Selection diagram] Figure 6

Description

The present invention relates to a fuel injection system equipped with an injection pump for use in marine engines and the like. In particular, the present invention relates to a fuel injection system including an injection pump for injecting alternative fuel such as ammonia into fossil fuel.

In recent years, due to problems such as global warming, there has been a demand for the realization of so-called zero emissions, which is the reduction of carbon dioxide emissions to zero. For this reason, it is difficult to achieve zero emissions with existing marine engines that use fossil fuels such as heavy oil as fuel, so marine engines that burn both alternative fuels such as ammonia and fossil fuels such as heavy oil, so-called "mixed combustion" Engines are being considered.

For example, in Patent Document 1 listed below, in order to co-combust fossil fuel and alternative fuel, a fuel injection valve that injects fossil fuel and alternative fuel in layers is provided, and the fossil fuel and alternative fuel are injected from this fuel injection valve and combusted. A method for co-firing in a chamber is disclosed.

In Patent Document 1, in order to inject the fossil fuel and the alternative fuel from the fuel injection valve 30 in a layered manner, the fuel pump 41 and the injection pump 51 are configured to pump the fossil fuel and the alternative fuel.

At this time, in the case of an engine with multiple cylinders, the amount of alternative fuel supplied from the injection pump must be adjusted to match the ratio of fossil fuel to each fuel injection valve in order to stabilize the combustion state of each cylinder. The same amount must be matched for each injector.

As a system for making the supply amount of alternative fuel equal to the same amount for each fuel injection valve, there is a water injection pump 41 described in Patent Document 2 below. In this water injection pump 41, a plurality of water discharge passages 2a, 2b, 2c connected to each fuel injection valve are pressed by water piston parts 6a, 6b, 6c connected to one connecting part 8, and each water The amount of water discharged from the discharge passages 2a, 2b, and 2c is made equal for each fuel injection valve.

By using the structure of the water injection pump 41 as an alternative fuel injection pump, it is possible to match the supply amount of the alternative fuel to the same amount for each fuel injection valve.

Japanese Patent Application Publication No. 2020-180567 JP2020-60110A

Indeed, as described in the above-mentioned Patent Document 2, since a plurality of discharge passages are pressed by a plurality of piston parts connected to one connection part, the lift amount (pressure amount) of each piston part is It appears possible to match and match the amount of alternative fuel discharged from each discharge passage in the same amount.

However, the viscosity of ammonia, a typical alternative fuel, is 0.115 mPa・s (milliPascal seconds) at 20°C, which is only about 1/10 of that of water, which is 1.01 mPa・s (milliPascal seconds). Therefore, as in Patent Document 2, even if the pressure is applied by multiple piston parts connected by one connecting part, ammonia leaks from the gap between the piston part and the discharge passage (piston sliding part), There is a problem that the same amount cannot be discharged. That is, since the width of the gap between the piston part and the discharge passage (piston sliding part) differs from one to another, the amount of ammonia leaked varies depending on the individual difference, and the same amount cannot be discharged.

Of course, in order to prevent leakage from the gap between the piston portion and the discharge passage (piston sliding portion), it is possible to improve the sealing performance by using a sealing member, a ring member, or the like to prevent leakage.

However, when such sealing members and ring members are used to improve the sealing performance, the sliding resistance between the piston part and the discharge passage (piston sliding part) increases, which obstructs the lifting movement of the piston part, making it difficult to smoothly lift the piston part. A problem arises in that the piston part does not lift and sufficient alternative fuel cannot be discharged.

The present invention has been made in view of the above, and its purpose is to provide a fuel injection system equipped with an injection pump for injecting an alternative fuel such as ammonia into fossil fuel, the viscosity of which is lower than that of water. When injecting alternative fuel, even if there are individual differences in the width of the gap between the piston part and the discharge passage (piston sliding part), it is possible to inject the same amount of alternative fuel into multiple fuel injection valves. An object of the present invention is to provide a fuel injection system equipped with an injection pump that can be used.

In order to achieve that objective, the present invention provides a fuel injection system including an injection pump for injecting alternative fuel such as ammonia into fossil fuel, in which an injection pump section is set separately for each fuel injection valve. The present invention is characterized in that the amount of injection from each injection pump section is individually controlled so that the amount of injection from each injection pump section corresponding to each fuel injection valve provided in the same cylinder is the same. That is.

Specifically, the first invention is used in a multi-cylinder engine that co-combusts fossil fuel and alternative fuel in a combustion chamber, and includes an injection pump that supplies the alternative fuel to the fuel injection valve. A fuel injection system comprising:
The injection pump includes a plurality of injection pump sections configured to respectively inject alternative fuel into each fuel injection valve, and the injection pump section has a plurality of injection pump sections each configured to inject alternative fuel into the same cylinder. The present invention is characterized by comprising injection amount control means for controlling the injection amount to be the same as that of another injection pump section that injects alternative fuel into the injection valve.

According to this configuration, a plurality of injection pump sections are provided so as to inject alternative fuel into each fuel injection valve, and the injection amount control means controls the injection amount of alternative fuel of each injection pump section provided in the same cylinder. and other injection pump parts that inject alternative fuel into the fuel injection valves.

For this reason, the injection amount from each injection pump section to each fuel injection valve is individually controlled, so when injecting an alternative fuel with a low viscosity such as ammonia, leaks may occur due to individual differences between each injection pump section. To make the amount of fuel injected from each injection pump section to the fuel injection valve the same among the injection pump sections that inject alternative fuel into the fuel injection valves provided in the same cylinder, even if the amount varies widely. Can be done.

Note that the term "alternative fuel" as used herein refers to fluid fuels that have a viscosity lower than that of water, such as ammonia and methanol, among fuels that replace petroleum.

A second aspect of the invention is that the injection amount control means includes a discharge amount measuring means for measuring the amount of alternative fuel discharged from each injection pump section that injects the alternative fuel into a fuel injection valve provided in the same cylinder; an average discharge amount calculating means for calculating an average discharge amount of all injection pump sections that inject alternative fuel into fuel injection valves provided in the same cylinder from the discharge amount of the alternative fuel measured by the amount measuring means; and calculating the average value. Lift amount control means for controlling the lift amount of each of the infusion pump sections so that the discharge amount of each of the infusion pump sections becomes the average discharge amount based on the average discharge amount calculated by the means. That is.

According to this configuration, the discharge amount measuring means measures the discharge amount from each injection pump section that injects alternative fuel into the fuel injection valve provided in the same cylinder, and the average discharge amount calculating means measures the discharge amount. The average discharge amount is calculated from the above, and the lift amount control means controls the lift amount of each injection pump section so that it becomes the average discharge amount.

Therefore, the lift amount of each injection pump section is individually controlled based on the average discharge amount, so that each injection pump section discharges alternative fuel with a different lift amount.

Therefore, even if the amount of leakage differs in each injection pump section, by controlling each injection pump section with a different lift amount, the amount of leakage from all injection pump sections injecting alternative fuel into the fuel injection valve installed in the same cylinder can be reduced. The same amount of alternative fuel can be injected into each fuel injector.

A third aspect of the invention is that the injection amount control means includes a leak amount measuring means for measuring the amount of leakage of the alternative fuel from each injection pump section that injects the alternative fuel into the fuel injection valve provided in the same cylinder; a discharge amount estimating means for calculating an estimated discharge amount of each injection pump section by subtracting the leak amount of the alternative fuel measured by the amount measuring means from the stroke volume of each injection pump section; an average estimated discharge amount calculation means for calculating an average estimated discharge amount of all injection pump units that inject alternative fuel into fuel injection valves provided in the same cylinder from an estimated discharge amount of the alternative fuel; Lift amount control means for controlling the lift amount of each of the infusion pump sections so that the discharge amount of each of the infusion pump sections becomes the average estimated discharge amount based on the average estimated discharge amount calculated by the means. It is characterized by:

According to this configuration, the leak amount measuring means measures the leak amount of the alternative fuel from each injection pump section that injects the alternative fuel into the fuel injection valve provided in the same cylinder, and the discharge amount estimating means measures the leak amount of the alternative fuel from each injection pump section that injects the alternative fuel into the fuel injection valve provided in the same cylinder. The leak amount of the alternative fuel is subtracted from the stroke volume of each injection pump section to calculate the estimated discharge amount of each injection pump section, and the average estimated discharge amount calculation means calculates the estimated discharge amount of all injection pumps from the estimated discharge amount. The lift amount control means controls the lift amount of each infusion pump section so that the discharge amount of each infusion pump section becomes the average estimated discharge amount.

Therefore, the lift amount of each injection pump section is individually controlled based on the average estimated discharge amount, so each injection pump section discharges alternative fuel with a different lift amount. . In other words, if the leakage amount of each injection pump section is different, it is thought that the discharge amount is also different, so even if it is not possible to measure the flow rate of the alternative fuel actually discharged, the leakage amount can be measured and each injection pump section can be measured. The lift of the injection pump is controlled to supply the same amount of alternative fuel to each fuel injector.

Therefore, even if the amount of leakage differs in each injection pump section, by controlling each injection pump section with a different lift amount, the amount of leakage from all injection pump sections injecting alternative fuel into the fuel injection valve installed in the same cylinder can be reduced. The same amount of alternative fuel can be supplied to the fuel injector.

A fourth aspect of the present invention is that the injection amount control means includes a lift speed measuring means for measuring a lift speed of each injection pump section that injects alternative fuel into a fuel injection valve provided in the same cylinder; A discharge amount estimating means for calculating the estimated discharge amount of each injection pump section from the measured lift speed, and a discharge amount estimating means for calculating the estimated discharge amount of the alternative fuel calculated by the discharge amount estimating means. Average estimated discharge amount calculation means calculates the average estimated discharge amount of all injection pump sections that inject alternative fuel, and the discharge amount of each injection pump section is calculated from the average estimated discharge amount calculated by the average estimated discharge amount calculation means. The present invention is characterized by comprising: lift amount control means for controlling the lift amount of each of the injection pump sections so that the average estimated discharge amount becomes the average estimated discharge amount.

According to this configuration, the lift speed measuring means measures the lift speed of each injection pump section that injects alternative fuel into the fuel injection valve provided in the same cylinder, and the discharge amount estimating means measures the lift speed of each injection pump section based on the lift speed. The estimated discharge amount of the pump section is calculated, the average estimated discharge amount calculation means calculates the average estimated discharge amount of all the infusion pump sections from the estimated discharge amount, and the lift amount control means calculates the average estimated discharge amount of each infusion pump section. The lift amount of each injection pump section is controlled so that the discharge amount becomes the average estimated discharge amount.

Therefore, the lift amount of each injection pump section is individually controlled based on the average estimated discharge amount, so each injection pump section discharges alternative fuel with a different lift amount. . In other words, if the lift speed of each injection pump section is different, it is thought that the discharge amount is also different, so even if it is not possible to measure the flow rate of the alternative fuel actually discharged, the lift speed can be measured and each injection pump section can be measured. The lift of the injection pump is controlled to supply the same amount of alternative fuel to each fuel injector.

Therefore, by measuring the lift speed of the injection pump section, the discharge amount of each injection pump section can be indirectly estimated, and the discharge amount of all injection pump sections that inject alternative fuel into the fuel injection valves installed in the same cylinder can be estimated indirectly. The discharge amount can be made approximately the same.

A fifth aspect of the present invention is that the injection amount control means includes an internal pressure measuring means for measuring the internal pressure at the time of lift of each injection pump section that injects alternative fuel into the fuel injection valve provided in the same cylinder, and the internal pressure measuring means. A discharge amount estimating means calculates the estimated discharge amount of each injection pump section from the measured internal pressure, and an alternative fuel injection valve installed in the same cylinder uses the estimated discharge amount of the alternative fuel calculated by the discharge amount estimating means. The discharge amount of each injection pump section is determined from the average estimated discharge amount calculation means that calculates the average estimated discharge amount of all the injection pump sections that inject fuel, and the average estimated discharge amount calculated by the average estimated discharge amount calculation means. The invention is characterized by comprising a lift amount control means for controlling the lift amount of each of the injection pump sections so that the estimated average discharge amount is achieved.

According to this configuration, the internal pressure measuring means measures the internal pressure at the time of lift of each injection pump section that injects alternative fuel into the fuel injection valve provided in the same cylinder, and the discharge amount estimating means measures the measured internal pressure. The estimated discharge amount of each injection pump section is calculated from the above, and the average estimated discharge amount calculation means calculates the average estimated discharge amount of all the injection pump sections from the estimated discharge amount, and the lift amount control means calculates the estimated discharge amount of each injection pump section. The lift amount of each injection pump section is controlled so that the discharge amount of the pump section becomes the average estimated discharge amount.

Therefore, the lift amount of each injection pump section is individually controlled based on the average estimated discharge amount, so each injection pump section discharges alternative fuel with a different lift amount. . In other words, if the internal pressure of each injection pump section is different during lift, it is thought that the discharge amount will also be different, so even if it is not possible to measure the flow rate of the alternative fuel actually discharged, it is possible to measure the internal pressure during lift. Then, the lift amount of each injection pump section is controlled to supply the same amount of alternative fuel to each fuel injection valve.

Therefore, by measuring the internal pressure of the injection pump section when it is lifted, the discharge amount of each injection pump section can be indirectly estimated, and all injection pumps that inject alternative fuel into the fuel injection valves installed in the same cylinder. It is possible to make the discharge amount of the two parts almost the same.

As explained above, according to the present invention, the injection amount from each injection pump section to each fuel injection valve is individually controlled, so when injecting an alternative fuel with a low viscosity such as ammonia, Even if the amount of leakage varies greatly due to the difference in the width of the gap between the piston part and the discharge passage (piston sliding part), the fuel is supplied from each injection pump part to each fuel injection valve installed in the same cylinder. The amount of alternative fuel can be the same.

Therefore, in a fuel injection system equipped with an injection pump that injects alternative fuel such as ammonia into fossil fuel, when injecting alternative fuel such as ammonia whose viscosity is lower than that of water, it is necessary to ) Even if there are individual differences in the width of the gaps between the fuel injection valves, the same amount of alternative fuel can be injected into multiple fuel injection valves.

1 is a schematic diagram showing the overall configuration of a marine engine according to Embodiment 1 of the present invention. 1 is a system schematic diagram showing a system configuration of a fuel injection device. FIG. 2 is a detailed longitudinal sectional view showing a combustion chamber of a marine engine. FIG. 3 is a vertical cross-sectional view showing the detailed structure of the first infusion pump section of Embodiment 1. FIG. (a) A diagram showing the first injection pump section when discharging fuel, and (b) a diagram showing the first injection pump section when filling fuel. 3 is a control flowchart according to the first embodiment. FIG. 7 is a vertical cross-sectional view showing the detailed structure of the first infusion pump section of Embodiment 2. 7 is a control flowchart according to Embodiment 2. FIG. 7 is a vertical cross-sectional view showing the detailed structure of the first infusion pump section of Embodiment 3. 12 is a control flowchart according to Embodiment 3. FIG. 7 is a vertical cross-sectional view showing the detailed structure of the first infusion pump section of Embodiment 4. 7 is a control flowchart according to Embodiment 4.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. The following description of preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its applications, or its uses.

(Embodiment 1)
FIG. 1 is a schematic diagram showing the overall configuration of a marine engine, FIG. 2 is a system schematic diagram showing the system configuration of a fuel injection device, and FIG. 3 is a detailed longitudinal section showing the combustion chamber of the marine engine. FIG. 4 is a top view, and FIG. 4 is a longitudinal sectional view showing the detailed structure of the infusion pump. First, an outline of the marine engine 1 will be explained using these figures. Hereinafter, the marine engine 1 will be simply referred to as "engine 1."

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

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

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

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

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

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

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

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

Further, the cylinder cover 15 is provided with an exhaust valve 18 operated by an exhaust valve device (not shown in FIG. 1). The exhaust valve 18 defines a combustion chamber 17 together with a cylinder 16 made up of a cylinder liner 14 and a cylinder cover 15, and the top surface of a piston 21. The exhaust valve 18 opens and closes the space between the combustion chamber 17 and the exhaust pipe 19. The exhaust pipe 19 has an exhaust port (not shown) communicating with the combustion chamber 17, and the exhaust valve 18 is configured to open and close the exhaust port.

Further, the cylinder cover 15 defines a ceiling surface of the combustion chamber 17. A fuel injection valve 30 is provided on this ceiling surface.

As shown in FIG. 3, the fuel injection valve 30 is provided in a position facing into the combustion chamber 17, and has an injection port 31 for injecting fossil fuel and alternative fuel. Although only one fuel injection valve 30 is shown in FIG. 3, three fuel injection valves are originally provided in this embodiment.

Specifically, the fuel injection valve 30 is arranged with the injection port 31 facing into the combustion chamber 17, and is configured to inject fuel in layers with fossil fuel and alternative fuel arranged alternately. .

Here, the alternative fuel functions as the main fuel that generates the power of the engine 1, and the fossil fuel functions as a pilot fuel for igniting the main fuel. In this embodiment, diesel fuel (so-called "heavy oil") is used as the fossil fuel, and ammonia is used as the alternative fuel.

The fuel injection system 100 that supplies fuel to the fuel injection valve 30 will be described later using FIG. 2.

In this way, the fuel injection valve 30 injects the fossil fuel and the alternative fuel into the combustion chamber 17 to combust both within the combustion chamber 17 . Combustion of this fossil fuel and alternative fuel is called "mixed combustion." Note that the details of "mixed firing" will be described later.

This combustion causes the piston 21 shown in FIG. 1 to reciprocate in the vertical direction. At this time, when the exhaust valve 18 operates to open the combustion chamber 17, exhaust gas generated by combustion is pushed out to the exhaust pipe 19, and scavenging air enters the combustion chamber 17 from a scavenging port (not shown) provided below. be introduced.

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

Next, the fuel injection system 100 that supplies fuel to the fuel injection valve 30 will be described using FIG. 2.

This fuel injection system 100 includes a fuel pump 41 that pumps fossil fuel to the fuel injection valve 30, and an injection pump 51 that injects alternative fuel into a path through which the fossil fuel is pumped. The injection pump 51 is composed of a first injection pump section 51a, a second injection pump section 51b, and a third injection pump section 51c, corresponding to the three fuel injection valves 30.

These fuel pump 41 and injection pump parts 51a, 51b, and 51c are arranged near the cylinder 16, as shown in FIG. It is connected to the fuel injection valves 30 through pipes 52a, 52b, 52c.

Of these, the fuel pump 41 is connected to the fuel injection valve 30 via a fossil fuel path L extending from the fuel pump 41 to the injection port 31, and pumps fossil fuel toward the fuel injection valve 30. This fossil fuel path L is composed of a first internal path 32 and a fuel injection pipe 42 (including a branch pipe 42a described below), and is configured as a path connecting the fuel pump 41 and the injection port 31.

In addition, the injection pump sections 51a, 51b, 51c are connected to the fossil fuel path L via the second internal path 33 and injection pipes 52a, 52b, 52c, and inject alternative fuel into the fossil fuel path L. It is configured as follows.

With this configuration, the fuel injection valve 30 injects the fossil fuel fed under pressure from the fuel pump 41 and the alternative fuel injected from the injection pump sections 51a, 51b, and 51c into the combustion chamber 17 in a stratified manner. be able to.

In addition, in the engine of this embodiment, three fuel injection valves 30 are provided in each cylinder. For this reason, the fuel injection pipe 42 is branched into three branch pipes (42a, 42b, 42c) via a branch part 43 so that fossil fuel can be supplied to each fuel injection valve 30....

Further, the fuel pump 41 that pumps fossil fuel and the injection pump sections 51a, 51b, and 51c that inject alternative fuel are controlled by a control section 92. Specifically, the fuel control valve 45 and injection control valves 55a, 55b, 55c are controlled by the control signal sent from the control unit 92, and the operation of the fuel pump 41 and injection pump units 51a, 51b, 51c is controlled. ing.

A detection unit 91 that detects various signals such as the crank angle of the engine 1 is connected to this control unit 92, and based on the various signals detected by this detection unit 91, the fuel pump 41 and the injection pump unit 51a , 51b, 51c. Note that the broken line in FIG. 2 indicates electrical connection.

The fuel pump 41 is connected to a fuel tank (not shown) in which fossil fuel is stored through piping or the like (not shown), and is configured to receive fossil fuel from this fuel tank.

On the other hand, an alternative fuel supply pump 71 that supplies alternative fuel is connected to the injection pump parts 51a, 51b, and 51c through a supply pipe 72, and the arrangement is such that the alternative fuel is supplied from this alternative fuel supply pump 71. ing. The alternative fuel supply pump 71 is also connected to an alternative fuel tank (not shown) in which alternative fuel is stored through piping or the like (not shown), and configured to receive the alternative fuel from this alternative fuel tank. There is.

Further, a pressure accumulating section 81 is connected to the fuel pump 41 and the injection pump sections 51a, 51b, and 51c. This pressure accumulating section 81 is for accumulating pressure of hydraulic oil that operates the fuel pump 41 and the injection pump sections 51a, 51b, and 51c, respectively. The pressure accumulator 81 is connected to a high-pressure pump 82 and is configured to store hydraulic oil pressure-fed from the high-pressure pump 82 and to accumulate pressure therein.

In addition, check valves Cv... are installed at respective locations in the alternative fuel paths (supply pipe 72, injection pipes 52a, 52b, 52c, second internal path 33) for injecting the alternative fuel to prevent backflow of the alternative fuel. It is set up.

With the fuel injection system 100 configured as described above, in the engine 1 of the present embodiment, the control unit 92 injects fossil fuel and alternative fuel into the combustion chamber 17 from the fuel injection valves 30 . Mixed combustion will occur.

Next, the detailed structure of the infusion pump of this embodiment will be described using FIG. 4. As described above, the infusion pump of this embodiment is composed of three parts: the first infusion pump part 51a, the second infusion pump part 51b, and the third infusion pump part 51c. , shows a longitudinal cross-sectional view of the first infusion pump section 51a.

The first injection pump section 51a includes a cylindrical housing 101 with a hollow interior, a hydraulic piston 102 provided at a lower part inside the housing 101 so as to move in the axial direction (vertical direction), and the hydraulic piston. a plunger 103 provided above the plunger 102 so as to move in the axial direction integrally with the plunger 102; a fuel filling chamber 104 provided above the plunger 103 capable of filling an internal space with an alternative fuel; and the housing. an upper fixing plug 105 fixed to the upper part of the housing 101; a lower fixing plug 106 fixed to the lower part of the housing 101 and guiding the hydraulic piston 102 in the axial direction on its inner peripheral surface; An inner cylindrical member 107 located and fixed to the housing 101, a plunger spring 108 located on the outer peripheral side of the inner cylindrical member 107 and applying an axially downward biasing force to the plunger 103, and the plunger. A sleeve member 109 that supports a spring 108 and is locked to the plunger 103 is provided.

The above-mentioned upper fixed plug 105 is configured to have a fuel inlet 110 penetrating from the radially outer side to the radially inner side, and supply alternative fuel to the fuel filling chamber 104 below the fuel inlet 110. Further, a discharge port 112 equipped with a check valve 111 is provided above in the axial direction, and the alternative fuel in the fuel filling chamber 104 is discharged to the outside from the discharge port 112. Furthermore, a flow meter 113 is provided in the injection pipe 52a above the discharge port 112 to measure the flow rate of the discharged alternative fuel.

The operation of the first infusion pump section 51a configured in this way will be explained with reference to FIG. 5. FIG. 5A is a diagram showing the first injection pump section 51a when discharging the alternative fuel, and FIG. 5B is a diagram showing the first injection pump section 51a when filling the alternative fuel.

First, as shown in FIG. 5(a), when discharging alternative fuel, when the aforementioned control section 92 opens the injection control valve 55a, the driving oil pressure acts on the hydraulic piston 102 as shown by the solid arrow. , pushes the hydraulic piston 102 upward. As the hydraulic piston 102 rises, the plunger 103 also rises as shown by the arrow.

Then, the discharge pressure from the plunger 103 acts on the alternative fuel filled in the fuel filling chamber 104, and the alternative fuel is discharged to the outside from the discharge port 112 against the check valve 111.

The alternative fuel thus discharged is supplied to the fuel injection valve 30 via the injection pipe 52a described above.

On the other hand, as shown in FIG. 5(b), when filling with alternative fuel, the control section 92 described above closes the injection control valve 55a and does not apply the drive oil pressure as shown by the dotted arrow. Then, due to the biasing force of the plunger spring 108, the hydraulic piston 102 and the plunger 103 descend as shown by the arrow. When the plunger 103 descends in this way, the fuel filling chamber 104 above it expands and negative pressure is generated. The negative pressure then draws the alternative fuel into the fuel filling chamber 104 from the fuel inlet 110.

By operating the first injection pump section 51a in this manner, the alternative fuel is discharged from the first injection pump section 51a to the fuel injection valve 30. Note that the other second injection pump section 51b and third injection pump section 51c operate in the same manner, and the alternative fuel is discharged to the fuel injection valve 30.

By the way, in order to stabilize the combustion state in the same cylinder, the amount of alternative fuel supplied from these injection pump parts 51a, 51b, 51c is made to have the same ratio with fossil fuel for each fuel injection valve 30 of the same cylinder. It is necessary to match the same amount for each fuel injection valve 30.

However, the viscosity of ammonia, which is an alternative fuel, is 0.115 mPa·s at 20°C, which is only about 1/10 that of water, which is 1.01 mPa·s. Therefore, there is a problem in that ammonia, which is this alternative fuel, passes through the gap between the plunger 103 and the inner cylinder member 107 and leaks to the hydraulic piston 102 side.

This amount of leakage is determined by individual differences between the infusion pump parts 51a, 51b, and 51c, and therefore differs between each of the infusion pump parts 51a, 51b, and 51c. That is, the width of the gap between the plunger 103 and the inner cylinder member 107 differs among the injection pump parts 51a, 51b, and 51c due to individual differences, so the amount of leakage differs. Therefore, if the lift amount etc. of the hydraulic piston 102 etc. are made to match, the discharge amount of each injection pump part 51a, 51b, 51c will conversely vary among each injection pump part 51a, 51b, 51c. There is a problem.

Therefore, in this embodiment, a flow meter 113 is provided to measure the flow rate of the discharged alternative fuel, and the discharge amount of the injection pump 51 is controlled based on the measurement result of the flow meter 113.

Next, control of the infusion pump 51 of this embodiment will be explained with reference to a control flowchart shown in FIG.

First, in S1, the control unit 92 reads various information. Various information necessary for engine control is read from the detection unit 91, such as the position of the ship, the operating state of the ship, and information on the operator's operation from GPS signals and the like.

Next, in S2, the flow meter 113 measures the discharge amount of each injection pump section 51a, 51b, 51c.

Thereafter, in S3, the control unit 92 calculates an average ejection amount from this ejection amount. Specifically, the discharge amount of the first infusion pump section 51a, the discharge amount of the second infusion pump section 51b, and the discharge amount of the third infusion pump section 51c are all added up, and the value divided by 3 is calculated as the average discharge amount. Calculate as a quantity.

Then, in S4, the first infusion pump part 51a, the second infusion pump part 51b, and the third infusion pump part 51c are lifted so that the discharge amount of each infusion pump part 51a, 51b, and 51c becomes the average discharge amount. Control quantity.

Thereafter, the process shifts to return in preparation for the next control cycle.

By controlling in this way, the lift amount of each of the injection pump sections 51a, 51b, and 51c is controlled so that all the injection pump sections have the same discharge amount. That is, the lift amount is controlled to be large in the infusion pump section with a small discharge amount, and the lift amount is controlled to be small in the infusion pump section with a large discharge amount.

Therefore, since the same amount of alternative fuel is discharged from all the injection pump parts 51a, 51b, 51c and supplied to each fuel injection valve 30, stable co-combustion can be achieved in the combustion chamber 17 of the same cylinder of the engine 1. Once the condition is obtained, the engine 1 will be operated.

As described above, in this embodiment, the fuel injection system 100 is used in the multi-cylinder engine 1 that co-combusts fossil fuel and alternative fuel in the combustion chambers 17, and includes the injection pump 51 that supplies alternative fuel to the fuel injection valve. The injection pump 51 includes a plurality of injection pump sections 51a, 51b, 51c configured to inject alternative fuel into each fuel injection valve 30, respectively. and a control unit 92 that controls the injection amount of each alternative fuel to be the same between other injection pump units that inject alternative fuel into the fuel injection valves 30 provided in the same cylinder. ing.

As a result, the control unit 92 adjusts the amount of alternative fuel injected into each of the injection pump parts 51a, 51b, and 51c between the other injection pump parts that inject alternative fuel into the fuel injection valves 30 provided in the same cylinder. are controlled to be the same.

Therefore, since the injection amount from each injection pump part 51a, 51b, 51c to each fuel injection valve 30 is individually controlled, when injecting an alternative fuel with low viscosity such as ammonia, each injection Even if the amount of leakage varies greatly due to individual differences between the pump parts 51a, 51b, 51c, the amount of fuel injected from each injection pump part 51a, 51b, 51c into the fuel injection valve 30... The injection pump parts 51a, 51b, and 51c that inject alternative fuel into the injection valves 30 can be made the same.

Therefore, in a fuel injection system 100 that includes an injection pump 51 that injects an alternative fuel such as ammonia into a fossil fuel, there are individual differences in the injection pump part when injecting an alternative fuel such as ammonia whose viscosity is lower than that of water. Even in this case, the same amount of alternative fuel can be injected into the plurality of fuel injection valves 30.

Although ammonia is exemplified as an alternative fuel in this embodiment, an alternative fuel such as methanol, which has a viscosity lower than water, such as 0.62 mPa·s at 20° C., may also be used. In addition, a fluid fuel that can be substituted for petroleum and has a viscosity lower than that of water may also be used.

In addition, in this embodiment, a flow meter 113 that measures the discharge amount of alternative fuel from each injection pump section 51a, 51b, 51c, and a The average discharge amount of all the injection pump sections 51a, 51b, 51c that inject alternative fuel into the fuel injection valves 30... is calculated, and from the average discharge amount, the discharge amount of each injection pump section 51a, 51b, 51c is calculated as follows. A control section 92 is provided to control the lift amount of each injection pump section 51a, 51b, 51c so that the average discharge amount is achieved.

As a result, the lift amount of each infusion pump part 51a, 51b, 51c is individually controlled based on the average discharge amount of all infusion pump parts, so each infusion pump part 51a, 51b, 51c will each discharge alternative fuel with different lift amounts.

Therefore, even if the injection pump parts 51a, 51b, 51c have different leakage amounts, by controlling the injection pump parts 51a, 51b, 51c with different lift amounts, the fuel injection valves 30... provided in the same cylinder... The same amount of alternative fuel can be injected into each fuel injection valve 30 from all the injection pump parts 51a, 51b, 51c.

(Embodiment 2)
Next, a second embodiment will be described. Embodiment 2 will be described using a vertical cross-sectional view showing the detailed structure of the first infusion pump section in FIG. 7 and a control flowchart in FIG. 8. The other configurations are the same as those in the first embodiment, so the same reference numerals will be used and the description will be omitted.

Embodiment 2 does not measure the discharge amount of alternative fuel as in Embodiment 1, but measures the amount of alternative fuel leaked from each injection pump section 51a, 51b, and 51c. This controls the lift amount of the pump parts 51a, 51b, and 51c.

For example, in order to measure the discharge amount of alternative fuel, it is necessary to install the flow meter 113 in the injection pipe 52a as in the first embodiment, but if the flow meter 113 is installed in the injection pipe 52a, This can create flow resistance and adversely affect the delivery of the alternative fuel. Therefore, in order to avoid such problems, in this embodiment, the discharge amount of each infusion pump part 51a, 51b, 51c is measured by measuring the leakage amount, and the discharge amount of each infusion pump part 51a, 51b, 51c is lifted. I try to control the amount.

Specifically, as shown in FIG. 7, a through hole 120 is provided in the lower part of the housing 101 of the first injection pump part 51a, and a discharge pipe 121 is provided to guide the alternative fuel leaking from the through hole 120 to the outside. A leak amount measuring device 122 is provided in the middle of this discharge pipe 121. The leak amount measuring device 122 is configured to measure the leak amount of the alternative fuel leaking from the fuel filling chamber 104 to the hydraulic piston 102 side.

Control in this embodiment is performed according to the control flowchart in FIG. 8.

First, in S11, the control unit 92 reads various information. Various information mainly required for engine control is read from the detection unit 91.

Next, in S12, the leakage amount of each injection pump section 51a, 51b, and 51c is measured by the leakage amount measuring device 122.

Thereafter, in S13, the control section 92 calculates the estimated discharge amount by subtracting the measured leakage amount from the stroke volume of each injection pump section 51a, 51b, 51c.

Then, in S14, an average estimated ejection amount is calculated from this estimated ejection amount. Specifically, the estimated discharge amount of the first infusion pump section 51a, the estimated discharge amount of the second infusion pump section 51b, and the estimated discharge amount of the third infusion pump section 51c are all added up and divided by 3. is calculated as the average estimated discharge amount.

After that, in S15, the first infusion pump part 51a, the second infusion pump part 51b, and the third infusion pump part 51c are adjusted so that the estimated discharge amount of each infusion pump part 51a, 51b, and 51c becomes the average estimated discharge amount. Controls pump lift amount.

After that, the process shifts to return in preparation for the next control cycle.

By controlling in this way, the lift amount of each of the injection pump sections 51a, 51b, and 51c is controlled so that all the injection pump sections have the same discharge amount.

Therefore, the same amount of alternative fuel is discharged from each injection pump section 51a, 51b, 51c and supplied to each fuel injection valve 30, so that stable co-combustion can be achieved in the combustion chamber 17 of the same cylinder of the engine 1. Once the condition is obtained, the engine 1 will be operated.

As described above, in this embodiment, the leak amount measuring device measures the leak amount of alternative fuel from each injection pump section 51a, 51b, 51c that injects alternative fuel into the fuel injection valve 30 provided in the same cylinder. 122 and the leak amount of the alternative fuel measured by the leak amount measuring device 122 is subtracted from the stroke volume of each injection pump section 51a, 51b, 51c to calculate the estimated discharge amount of each injection pump section 51a, 51b, 51c. Then, from the estimated discharge amount, calculate the average estimated discharge amount of all the injection pump units that inject alternative fuel into the fuel injection valves 30 provided in the same cylinder, and from the average estimated discharge amount, calculate the average estimated discharge amount of each injection pump. A control section 92 is provided to control the lift amount of each injection pump section 51a, 51b, 51c so that the discharge amount of the sections 51a, 51b, 51c becomes the average estimated discharge amount.

As a result, the lift amount of each infusion pump section 51a, 51b, 51c is controlled individually based on the average estimated discharge amount of each infusion pump section 51a, 51b, 51c. , 51b, and 51c each discharge alternative fuel with different lift amounts. In other words, if the leakage amount of each injection pump part 51a, 51b, 51c is different, it is thought that the discharge amount is also different, so even if the actual flow rate of the alternative fuel discharged cannot be measured, the leakage amount cannot be measured. The same amount of alternative fuel is supplied to each fuel injection valve by measuring and controlling the lift amount of each injection pump 51a, 51b, 51c.

Therefore, even if the injection pump parts 51a, 51b, 51c have different leakage amounts, each injection pump part 51a, 51b, 51c is controlled with a different lift amount, so that the fuel injection valves 30 provided in the same cylinder... The same amount of alternative fuel can be supplied to the plurality of fuel injection valves 30 from all the injection pump parts 51a, 51b, 51c that inject alternative fuel.

(Embodiment 3)
Next, Embodiment 3 will be described. Embodiment 3 will be described using a vertical cross-sectional view showing the detailed structure of the first infusion pump section in FIG. 9 and a control flowchart in FIG. 10. The other configurations are the same as those in the first embodiment, so the same reference numerals will be used and the description will be omitted.

In the third embodiment, the lift amount of each injection pump section 51a, 51b, 51c is controlled by measuring the lift speed of the hydraulic piston 102 of the first injection pump section 51a with a lift speed measuring device 130. .

For example, when measuring the discharge amount of alternative fuel or the amount of leakage of alternative fuel, it is necessary to install a flow meter etc. in the flow path of the alternative fuel. If provided, flow resistance will occur. Therefore, in order to avoid such flow resistance, in this embodiment, the lift speed of the hydraulic piston 102, which can indirectly know the discharge amount of the alternative fuel, is measured, and the injection pump parts 51a, 51b, 51c are The amount of lift is controlled. Note that instead of the lift speed of the hydraulic piston 102, the lift speed of the plunger 103 or the sleeve 109 may be measured.

Specifically, as shown in FIG. 9, a lift speed measuring device 130 is provided to measure the movement of the lower side surface of the hydraulic piston 102 of the first injection pump section 51a, and the alternative fuel is injected into the first injection pump section 51a. It is configured to measure the lift speed of the discharge hydraulic piston 102.

Control in this embodiment is performed according to the control flowchart shown in FIG.

First, in S21, the control unit 92 reads various information. Various information mainly required for engine control is read from the detection unit 91.

Next, in S22, the lift speed measuring device 130 measures the lift speed of the hydraulic piston 102 of each injection pump section 51a, 51b, 51c.

Thereafter, in S23, the control section 92 calculates the estimated discharge amount from the lift speed of each injection pump section 51a, 51b, 51c. For example, if the lift speed is high, it is estimated that the discharge amount is low. That is, if the lift speed is high, it is considered that the resistance of the hydraulic piston 102 is low and a large amount of leakage occurs, so it is considered appropriate to estimate that the discharge amount is low.

Then, in S24, an average estimated ejection amount is calculated from this estimated ejection amount. Specifically, the estimated discharge amount of the first infusion pump section 51a, the estimated discharge amount of the second infusion pump section 51b, and the estimated discharge amount of the third infusion pump section 51c are all added up and divided by 3. is calculated as the average estimated discharge amount.

After that, in S25, the first infusion pump part 51a, the second infusion pump part 51b, and the third infusion pump part 51c are adjusted so that the estimated discharge amount of each infusion pump part 51a, 51b, and 51c becomes the average estimated discharge amount. Controls pump lift amount.

After that, the process shifts to return in preparation for the next control cycle.

By controlling in this way, also in this embodiment, the lift amount of each infusion pump part 51a, 51b, 51c is controlled so that all the infusion pump parts 51a, 51b, 51c have approximately the same discharge amount. Ru.

Therefore, since almost the same amount of alternative fuel is discharged from all the injection pump parts 51a, 51b, 51c and supplied to each fuel injection valve 30, the combustion chamber 17 of the same cylinder of the engine 1 is stably The engine 1 will be operated in the mixed combustion state.

As described above, in this embodiment, the lift speed measuring device 130 that measures the lift speed of each injection pump section 51a, 51b, 51c that injects alternative fuel into the fuel injection valve 30 provided in the same cylinder, and From the lift speed measured by the lift speed measuring device 130, the estimated discharge amount of each injection pump section 51a, 51b, 51c is calculated, and from the estimated discharge amount, the average estimated discharge amount of all the injection pump sections is calculated, The control unit 92 is provided to control the lift amount of each injection pump section 51a, 51b, 51c so that the discharge amount of each injection pump section 51a, 51b, 51c becomes the average estimated discharge amount.

As a result, the lift amount of each infusion pump section 51a, 51b, 51c is individually controlled based on the average estimated discharge amount, so each infusion pump section 51a, 51b, 51c has a different lift amount. Each of these will discharge alternative fuel. In other words, if the lift speeds of the injection pump parts 51a, 51b, and 51c are different, it is thought that the discharge amounts are also different. The same amount of alternative fuel is supplied to each fuel injection valve 30 by measuring and controlling the lift amount of each injection pump 51a, 51b, 51c.

Therefore, by measuring the lift speed of each injection pump section 51a, 51b, 51c, the discharge amount of each injection pump section 51a, 51b, 51c can be indirectly estimated, and the fuel injection valve 30 provided in the same cylinder can be indirectly estimated. It is possible to make the discharge amount of all the injection pump parts 51a, 51b, 51c which inject alternative fuel into almost the same level.

(Embodiment 4)
Next, Embodiment 4 will be described. Embodiment 4 will be described using a vertical cross-sectional view showing the detailed structure of the first infusion pump section in FIG. 11 and a control flowchart in FIG. 12. The other configurations are the same as those in the first embodiment, so the same reference numerals are used and the explanation will be omitted.

In the fourth embodiment, the lift amount of each injection pump section 51a, 51b, 51c is controlled by measuring the pressure inside the fuel filling chamber 104 of the first injection pump section 51a with a plunger internal pressure measuring device 140. It is.

For example, when the lift speed of the hydraulic piston 102 is measured as in the third embodiment, the discharge amount of the alternative fuel may not be accurately estimated due to the sliding resistance of the hydraulic piston 102 and the like. Therefore, in this embodiment, by directly measuring the pressure inside the fuel filling chamber 104, the discharge amount of the alternative fuel is estimated, and the lift amounts of the injection pump sections 51a, 51b, and 51c are controlled.

Specifically, as shown in FIG. 11, a plunger internal pressure measuring device 140 is provided to measure the pressure inside the fuel filling chamber 104 of the first injection pump section 51a, and the alternative fuel is injected into the first injection pump section 51a. It is configured to measure the pressure change in the fuel filling chamber 104 during discharge.

Control in this embodiment is performed according to the control flowchart in FIG. 12.

First, in S31, the control unit 92 reads various information. Various information mainly required for engine control is read from the detection unit 91.

Next, in S32, the plunger internal pressure of each injection pump section 51a, 51b, 51c, that is, the pressure in the fuel filling chamber 104, is measured by the plunger internal pressure measuring device 140.

Thereafter, in S33, the control section 92 calculates the estimated discharge amount from the plunger internal pressure of each injection pump section 51a, 51b, 51c. For example, if the plunger internal pressure is low, it is estimated that the discharge amount is small. That is, it is considered reasonable to assume that if the flange internal pressure is low, there is a lot of leakage and the discharge amount is small.

Then, in S34, an average estimated ejection amount is calculated from this estimated ejection amount. Specifically, the estimated discharge amount of the first infusion pump section 51a, the estimated discharge amount of the second infusion pump section 51b, and the estimated discharge amount of the third infusion pump section 51c are all added up and divided by 3. is calculated as the average estimated discharge amount.

After that, in S35, the first infusion pump section 51a, the second infusion pump section 51b, and the third infusion pump section 51c are adjusted so that the estimated discharge amount of each of the infusion pump sections 51a, 51b, and 51c becomes the average estimated discharge amount. Controls pump lift amount.

After that, the process shifts to return in preparation for the next control cycle.

By controlling in this way, also in this embodiment, the lift amount of each infusion pump part 51a, 51b, 51c is controlled so that all the infusion pump parts 51a, 51b, 51c have approximately the same discharge amount. Ru.

Therefore, since almost the same amount of alternative fuel is discharged from all the injection pump parts 51a, 51b, 51c and supplied to each fuel injection valve 30, the combustion chamber 17 of the same cylinder of the engine 1 is stably The engine 1 will be operated in the mixed combustion state.

As described above, in this embodiment, the plunger measures the internal pressure of the fuel filling chamber when each injection pump section 51a, 51b, 51c injects alternative fuel into the fuel injection valve 30 provided in the same cylinder when lifted. The estimated discharge amount of each injection pump section 51a, 51b, 51c is calculated from the internal pressure measured by the internal pressure measuring device 140 and the plunger internal pressure measuring device 104, and from the estimated discharge amount, the amount of fuel provided in the same cylinder is calculated. The average estimated discharge amount of all the injection pump sections 51a, 51b, 51c that inject alternative fuel into the injection valves 30... is calculated, and the discharge amount of each injection pump section 51a, 51b, 51c is made to be the average estimated discharge amount. The apparatus further includes a control section 92 that controls the lift amount of each injection pump section 51a, 51b, and 51c.

As a result, the lift amount of each infusion pump section 51a, 51b, 51c is individually controlled based on the average estimated discharge amount, so each infusion pump section 51a, 51b, 51c has a different lift amount. Each of these will discharge alternative fuel. In other words, the fact that the internal pressures of the injection pump parts 51a, 51b, and 51c during lift are different means that the discharge amount is also different, so even if the flow rate of the alternative fuel actually discharged cannot be measured, the lift The same amount of alternative fuel is supplied to each fuel injection valve 30 by measuring the internal pressure at the same time and controlling the lift amount of each injection pump section 51a, 51b, 51c.

Therefore, by measuring the internal pressure of the injection pump parts 51a, 51b, 51c when they are lifted, the discharge amount of each injection pump part 51a, 51b, 51c can be indirectly estimated, and the fuel injection amount provided in the same cylinder can be estimated indirectly. The discharge amount of all the injection pump parts 51a, 51b, 51c that inject alternative fuel into the valves 30 can be made approximately the same.

(Other embodiments)
Although various embodiments have been described above, the present invention is not limited to these, and even if the alternative fuel discharged from each injection pump part has a low viscosity such as ammonia and may cause leakage. , it is within the technical scope of the present invention as long as each infusion pump section can be individually controlled and the discharge amount can be made the same for all.

Further, the alternative fuel is not limited to ammonia, and may be any fuel such as biofuel, methanol, etc., as long as it has a viscosity lower than that of water.

As described above, the present invention relates to a fuel injection system including an injection pump used in a marine engine or the like. It is particularly useful in fuel injection systems that include injection pumps that inject alternative fuels such as ammonia into fossil fuels.

1 Marine engine 10 Cylinder 17 Combustion chamber 30 Fuel injection valve 51 Injection pump 51a First injection pump section 51b Second injection pump section 51c Third injection pump section 92 Control section 100 Fuel injection system 113...Flowmeter 122...Leak amount measuring device 130...Lift speed measuring device 140...Plunger internal pressure measuring device

Claims (5)

A fuel injection system that is used in a multi-cylinder engine that co-combusts fossil fuel and alternative fuel in a combustion chamber, and includes an injection pump that supplies alternative fuel from among the fossil fuel and alternative fuel to a fuel injection valve,
The injection pump includes a plurality of injection pump sections configured to respectively inject alternative fuel into each fuel injector;
injection amount control means for controlling the amount of alternative fuel injected into each of the injection pump sections to be the same as that of other injection pump sections that inject alternative fuel into fuel injection valves provided in the same cylinder; ,
A fuel injection system characterized by: Discharge amount measuring means, wherein the injection amount control means measures the amount of alternative fuel discharged from each injection pump section that injects the alternative fuel into a fuel injection valve provided in the same cylinder;
an average discharge amount calculating means for calculating an average discharge amount of all injection pump sections that inject alternative fuel into fuel injection valves provided in the same cylinder from the discharge amount of the alternative fuel measured by the discharge amount measuring means;
Lift amount control means for controlling the lift amount of each of the infusion pump sections so that the discharge amount of each of the infusion pump sections becomes the average discharge amount based on the average discharge amount calculated by the average value calculation means;
The fuel injection system according to claim 1, further comprising: Leak amount measuring means, wherein the injection amount control means measures the amount of leakage of the alternative fuel from each injection pump section that injects the alternative fuel into the fuel injection valve provided in the same cylinder;
Discharge amount estimating means for subtracting the leakage amount of the alternative fuel measured by the leakage amount measuring means from the stroke volume of each injection pump section to calculate an estimated discharge amount of each injection pump section;
Average estimated discharge amount calculating means for calculating the average estimated discharge amount of all injection pump units that inject alternative fuel into fuel injection valves provided in the same cylinder from the estimated discharge amount of the alternative fuel calculated by the discharge amount estimating means. and,
Lift amount control means for controlling the lift amount of each of the infusion pump sections so that the discharge amount of each of the infusion pump sections becomes the average estimated discharge amount based on the average estimated discharge amount calculated by the average estimated discharge amount calculation means. and,
The fuel injection system according to claim 1, further comprising: lift speed measuring means for measuring the lift speed of each injection pump section in which the injection amount control means injects the alternative fuel into a fuel injection valve provided in the same cylinder;
a discharge amount estimating means for calculating an estimated discharge amount of each of the injection pump sections from the lift speed measured by the lift speed measuring means;
Average estimated discharge amount calculating means for calculating the average estimated discharge amount of all injection pump units that inject alternative fuel into fuel injection valves provided in the same cylinder from the estimated discharge amount of the alternative fuel calculated by the discharge amount estimating means. and,
Lift amount control means for controlling the lift amount of each of the infusion pump sections so that the discharge amount of each of the infusion pump sections becomes the average estimated discharge amount based on the average estimated discharge amount calculated by the average estimated discharge amount calculation means. and,
The fuel injection system according to claim 1, further comprising: internal pressure measuring means for measuring the internal pressure at the time of lift of each injection pump section in which the injection amount control means injects the alternative fuel into a fuel injection valve provided in the same cylinder;
A discharge amount estimating means for calculating an estimated discharge amount of each of the infusion pump parts from the internal pressure measured by the internal pressure measuring means;
Average estimated discharge amount calculating means for calculating the average estimated discharge amount of all injection pump units that inject alternative fuel into fuel injection valves provided in the same cylinder from the estimated discharge amount of the alternative fuel calculated by the discharge amount estimating means. and,
Lift amount control means for controlling the lift amount of each of the infusion pump sections so that the discharge amount of each of the infusion pump sections becomes the average estimated discharge amount based on the average estimated discharge amount calculated by the average estimated discharge amount calculation means. and,
The fuel injection system according to claim 1, further comprising: