Fuel supply device and engine system

Abstract

To provide a fuel supply device and an engine system capable of securing combustion stability by mixing main fuel and combustion improver at a molecular level.SOLUTION: A fuel supply device 5 that is applied to an engine system 1 including an engine 2 that uses mixed fuel of main fuel such as ammonia and alcohol and a combustion improver comprising hydrocarbon-based liquid fuel such as light oil, kerosene oil or heavy oil and that supplies the mixed fuel to the engine 2 generates the mixed fuel by mixing a co-solvent, the main fuel and the combustion improver.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fuel supply device that supplies a mixed fuel of a main fuel such as ammonia and a combustion improver made of a hydrocarbon liquid fuel such as diesel to an engine, and an engine system equipped with the fuel supply device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is an engine system that operates by supplying a mixed fuel of a main fuel such as ammonia and a combustion improver made of a hydrocarbon liquid fuel such as diesel oil to the engine.

[0003] For example, according to Patent Document 1, a manufacturing apparatus for manufacturing an ammonia-blended fuel includes: an ammonia storage sealed container for storing liquefied ammonia; an improver storage sealed container for storing a improver that assists the combustion of ammonia; a mixing sealed container configured to obtain a mixture by stirring and mixing the ammonia and the improver with an agitator so that the mixture obtained by stirring and mixing with the agitator can maintain a gas-liquid equilibrium state; an ammonia introduction line connecting the ammonia storage sealed container and the mixing sealed container and provided with an ammonia quantitative introduction mechanism configured to introduce a predetermined amount of ammonia into the mixing sealed container; an improver introduction line connecting the improver storage sealed container and the mixing sealed container and provided with an improver quantitative introduction mechanism configured to introduce a predetermined amount of the improver from the improver storage sealed container into the mixing sealed container; and at least one liquid phase discharge line configured to discharge the mixture obtained by stirring and mixing with the agitator in the mixing sealed container from the mixing sealed container as an ammonia-blended fuel.

[0004] The manufacturing apparatus of Patent Document 1 is also provided with a temperature control mechanism configured to adjust the temperature of the mixture so that the saturated vapor pressure of the mixture in the sealed mixing container is within a temperature range that does not exceed the set pressure resistance of the sealed mixing container. Furthermore, the manufacturing apparatus of Patent Document 1 is provided with a surfactant storage container that stores a surfactant, and a surfactant introduction line that connects the surfactant storage container to the sealed mixing container and is provided with a surfactant quantitative introduction mechanism configured to introduce a predetermined amount of surfactant into the sealed mixing container, and in the sealed mixing container, the surfactant is stirred and mixed together with ammonia and a combustion improver by a stirrer, and the mixture containing the surfactant is discharged through a liquid phase discharge line. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-171351 Summary of the Invention [Problem to be solved by the invention]

[0006] In the prior art disclosed in Patent Document 1, a surfactant is used to promote mixing of the main fuel and the combustion improver, but the surfactant only mixes the main fuel and the combustion improver macroscopically and does not mix the main fuel and the combustion improver at a molecular level. Therefore, when a mixed fuel in which the main fuel and the combustion improver are mixed using a surfactant is burned in an engine, combustion stability may be reduced.

[0007] Furthermore, the conventional technology disclosed in Patent Document 1 attempts to maintain the properties of the mixed fuel by adjusting the temperature of the main fuel, combustion improver, or mixed fuel using a temperature adjustment mechanism, but since it is necessary to heat or cool the main fuel, combustion improver, or mixed fuel according to the target temperature, there is a concern that the temperature adjustment mechanism will become complicated and expensive.

[0008] An object of the present invention is to provide a fuel supply device and an engine system that can ensure combustion stability by mixing a main fuel with a combustion improver at a molecular level. [Means for solving the problem]

[0009] In order to solve the above problems, the fuel supply device of the present invention is a fuel supply device that supplies a mixed fuel of a main fuel and a combustion improver made of a hydrocarbon-based liquid fuel to an engine, and is characterized in that the mixed fuel is produced by mixing a compatibilizer, the main fuel, and the combustion improver.

[0010] An engine system of the present invention is characterized by including the fuel supply device described above and the engine that runs on the mixed fuel. [Effects of the Invention]

[0011] According to the present invention, a fuel supply device and an engine system are provided that can ensure combustion stability by mixing a main fuel with a combustion improver at a molecular level. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram illustrating an example of an engine system according to an embodiment of the present invention. [Figure 2] 1 is a graph that schematically shows a map illustrating the relationship between the mixture ratio of ethanol as the main fuel and diesel as the combustion improver, and the temperature of the mixed fuel. [Figure 3] 1 is a graph showing the relationship between the concentration of methanol, which is the main fuel in the mixed fuel, and the concentration of dodecanol, which is a compatibilizer added when the mixed fuel is completely mixed, for each temperature of the mixed fuel. [Figure 4] FIG. 4 is a schematic diagram showing another example of an engine system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] An engine system 1 according to an embodiment of the present invention will be described with reference to the drawings. The engine system 1 includes an engine 2, an intake passage 3, an exhaust passage 4, and a fuel supply device 5.

[0014] The engine 2 runs on a mixed fuel consisting of a main fuel such as ammonia or alcohol and a combustion improver consisting of a hydrocarbon liquid fuel such as diesel oil, kerosene, or heavy oil. For example, the engine 2 may be a diesel engine, but is not limited to a diesel engine as long as it runs on the above mixed fuel, and may be another internal combustion engine (engine).

[0015] The engine 2 is configured with a cylinder block 11 having a plurality of cylinders 12, but Fig. 1 shows only one cylinder 12. As shown in Fig. 1, each cylinder 12 is configured with a cylinder 13, a piston 14, and a cylinder head 15.

[0016] The cylinder 13 is formed, for example, in a cylindrical shape within the cylinder block 11, and the piston 14 is slidably housed within the cylinder 13. The cylinder head 15 is attached to the upper side of the cylinder 13, and the cylinder 13 and the cylinder head 15 form a combustion chamber 12a therein.

[0017] Below the cylinder 13 , a crankshaft 17 is connected to the piston 14 via a connecting rod 16 , and the reciprocating motion of the piston 14 is converted into the rotational motion of the crankshaft 17 via the connecting rod 16 .

[0018] The cylinder head 15 also has an intake port 18 and an exhaust port 19 that communicate with the combustion chamber 12a of the cylinder 13, and is equipped with an intake valve 20 and an exhaust valve 21 that open and close the intake port 18 and the exhaust port 19, respectively, to the combustion chamber 12a.

[0019] The intake port 18 is connected to the intake passage 3 and introduces air supplied from the intake passage 3 into the combustion chamber 12a, while the exhaust port 19 is connected to the exhaust passage 4 and discharges exhaust gas generated in the combustion chamber 12a into the exhaust passage 4. By opening the intake valve 20, a mixture of fuel gas and air can be taken into the combustion chamber 12a through the intake port 18, while by opening the exhaust valve 21, exhaust gas generated in the combustion chamber 12a can be exhausted through the exhaust port 19.

[0020] 1 illustrates an example in which an intake manifold 22 having branch passages 22a branching from the intake passage 3 to the plurality of cylinders 12 is provided between the intake passage 3 and the engine 2 to connect the intake passage 3 to the respective intake ports 18 of the plurality of cylinders 12, but alternatively, the intake passage 3 and the intake ports 18 may be directly connected. Also, in FIG. 1 illustrates an example in which an exhaust manifold 23 having branch passages 23a branching from the exhaust passage 4 to the plurality of cylinders 12 is provided between the exhaust passage 4 and the engine 2 to connect the exhaust passage 4 to the respective exhaust ports 19 of the plurality of cylinders 12, but alternatively, the exhaust passage 4 and the exhaust ports 19 may be directly connected.

[0021] The intake passage 3 circulates compressed and cooled air in the intake direction and supplies it to each cylinder 12 of the engine 2 via an intake port 18 of each cylinder 12. The exhaust passage 4 circulates exhaust gas generated in each cylinder 12 of the engine 2 and discharged via an exhaust port 19 in the exhaust direction and discharges it.

[0022] The fuel supply device 5 supplies a mixed fuel consisting of a main fuel and a combustion improver to the engine 2. The fuel supply device 5 includes a main fuel tank 30, a combustion improver tank 31, a compatibilizer tank 32, an agitator tank 33, an agitator 34, a mixed fuel injection device 35, a main fuel supply valve 36, a combustion improver supply valve 37, a compatibilizer supply valve 38 (a compatibilizer supply unit), a control device 40, a main fuel temperature sensor 41, a combustion improver temperature sensor 42, and a mixed fuel temperature sensor 43.

[0023] The main fuel tank 30 contains a main fuel made of a liquid fuel such as ammonia or alcohol. The main fuel tank 30 is connected to the stirring tank 33 via a main fuel flow path 30a, and the main fuel in the main fuel tank 30 is supplied to the stirring tank 33 via the main fuel flow path 30a by a main fuel pump (not shown) or the like.

[0024] The combustion improver tank 31 stores a combustion improver made of a hydrocarbon liquid fuel such as diesel oil, kerosene, or heavy oil. The combustion improver tank 31 is connected to the stirring tank 33 via a combustion improver flow path 31a, and the combustion improver in the combustion improver tank 31 is supplied to the stirring tank 33 via the combustion improver flow path 31a by a combustion improver pump (not shown) or the like.

[0025] The compatibilizer tank 32 contains a compatibilizer for promoting mixing of the main fuel and the combustion improver. Examples of the compatibilizer include higher alcohols such as dodecanol, n-butanol, i-butanol, pentanol, and octanol, or ethers such as dimethyl ether (DME). The compatibilizer tank 32 is connected to the stirring tank 33 via a compatibilizer flow path 32a, and the compatibilizer in the compatibilizer tank 32 is supplied to the stirring tank 33 via the compatibilizer flow path 32a by a compatibilizer pump (not shown) or the like.

[0026] The stirring tank 33 is an agitation vessel in which the main fuel and combustion improver in liquid state are agitated and mixed to produce a liquid mixed fuel consisting of the main fuel and combustion improver. The main fuel and combustion improver are supplied to the agitation tank 33 from the main fuel tank 30 and combustion improver tank 31, respectively, and a compatibilizer is also supplied from the compatibilizer tank 32. An agitator 34 is provided inside the agitation tank 33 to agitate the main fuel and combustion improver in liquid state. The agitator 34 is operated under the control of the control device 40 and agitates the main fuel, combustion improver, and compatibilizer in the agitation tank 33.

[0027] The stirring tank 33 is connected to the mixed fuel injection device 35 via a mixed fuel flow path 33a, and the mixed fuel in the stirring tank 33 is supplied to the mixed fuel injection device 35 via the mixed fuel flow path 33a by a mixed fuel pump 33b such as a feed pump. The mixed fuel pump 33b is disposed upstream of the mixed fuel injection device 35 and downstream of the stirring tank 33 in the direction of flow of the mixed fuel in the mixed fuel flow path 33a.

[0028] At this time, the mixed fuel produced by stirring and mixing the main fuel, combustion improver, and compatibilizer in the stirring tank 33 is supplied to the mixed fuel injection device 35 without being stored. For example, by supplying the main fuel, combustion improver, and compatibilizer to the stirring tank 33 per unit time in an amount equivalent to the amount of mixed fuel supplied per unit time by the mixed fuel injection device 35, stirring and mixing the main fuel, combustion improver, and compatibilizer, the storage of the mixed fuel is suppressed, and the mixed fuel is supplied to the mixed fuel injection device 35 before the temperature of the mixed fuel changes in the stirring tank 33.

[0029] Furthermore, the stirring tank 33 and the mixed fuel pump 33b are arranged so that the temperature change of the mixed fuel from the outlet of the stirring tank 33 to the inlet of the mixed fuel pump 33b in the flow direction of the mixed fuel in the mixed fuel flow path 33a is maintained within a predetermined range (for example, ±5°C). For example, the stirring tank 33 is arranged near the mixed fuel pump 33b, and specifically, the portion of the mixed fuel flow path 33a from the stirring tank 33 to the mixed fuel pump 33b is set within a predetermined length. Additionally or alternatively, a heat retention unit 33c is provided in the portion of the mixed fuel flow path 33a from the stirring tank 33 to the mixed fuel pump 33b. For example, the heat retention unit 33c may be made of a heat insulating material or may be configured to utilize the heat of the exhaust gas or the coolant.

[0030] The mixed fuel injection device 35 supplies mixed fuel to the combustion chamber 12a of the engine 2. The mixed fuel injection device 35 is configured to be controlled by the control device 40 so as to be able to adjust the amount of mixed fuel supplied. The mixed fuel injection device 35 is provided, for example, in the cylinder head 15 of the engine 2, and injects mixed fuel directly into the combustion chamber 12a.

[0031] Alternatively, the mixed fuel injector 35 may be provided in the intake port 18 communicating with the combustion chamber 12a of the engine 2, and may inject the mixed fuel into the intake port 18, thereby supplying the mixed fuel to the combustion chamber 12a via the intake port 18. Alternatively, the mixed fuel injector 35 may be provided in the intake manifold 22 communicating with the intake port 18 of the engine 2, and may inject the mixed fuel into the intake manifold 22, thereby supplying the mixed fuel to the combustion chamber 12a via the intake manifold 22 and the intake port 18.

[0032] The main fuel supply valve 36 is provided in the main fuel flow path 30a and is controlled by the control device 40 so as to be able to adjust the amount of main fuel supplied from the main fuel tank 30 to the stirring tank 33. The combustion improver supply valve 37 is provided in the combustion improver flow path 31a and is controlled by the control device 40 so as to be able to adjust the amount of combustion improver supplied from the combustion improver tank 31 to the stirring tank 33. The compatibilizer supply valve 38 (compatibilizer supply unit) is provided in the compatibilizer flow path 32a and is controlled by the control device 40 so as to be able to adjust the amount of compatibilizer supplied from the compatibilizer tank 32 to the stirring tank 33.

[0033] The control device 40 is a computer such as an ECU (Engine Control Unit) that controls the operation of the engine 2, and is equipped with a CPU, ROM, RAM, etc., and is configured to control each part of the engine 2. The control device 40 may store various programs for controlling the engine 2, and control the engine 2 by reading and executing the programs.

[0034] The main fuel temperature sensor 41 is a temperature detection unit provided in the main fuel tank 30 or the main fuel flow path 30a and detects the temperature of the main fuel supplied to the stirring tank 33. The main fuel temperature sensor 41 transmits the detected temperature of the main fuel to the control device 40. The combustion improver temperature sensor 42 is a temperature detection unit provided in the combustion improver tank 31 or the combustion improver flow path 31a and detects the temperature of the combustion improver supplied to the stirring tank 33. The combustion improver temperature sensor 42 transmits the detected temperature of the combustion improver to the control device 40. The mixed fuel temperature sensor 43 is a temperature detection unit provided in the stirring tank 33 or the mixed fuel flow path 33a and detects the temperature of the mixed fuel supplied from the stirring tank 33. The mixed fuel temperature sensor 43 transmits the detected temperature of the mixed fuel to the control device 40.

[0035] Next, the supply of a compatibilizer to a blended fuel consisting of a main fuel and a combustion improver will be described. When the main fuel and the combustion improver are simply mixed, phase separation may occur due to the characteristics of their molecular structures, preventing good mixing. For example, FIG. 2 shows a map showing the relationship between the blending ratio of ethanol (the main fuel) and diesel (the combustion improver) and the temperature of the blended fuel, which schematically illustrates a blending region where a good blended fuel is obtained and a phase separation region where phase separation occurs in the blended fuel. This map also shows a line graph of the temperature at which a good blended fuel is obtained, i.e., the critical dissolution temperature, versus the blending ratio of the main fuel and the combustion improver. This map shows that separation is most likely when the blending ratio of the main fuel and the combustion improver is around 50%, and that separation becomes more difficult as the proportion of the main fuel or the combustion improver increases. This map also shows that separation occurs more easily at lower blended fuel temperatures and less easily at higher blended fuel temperatures. In other words, the upper limit of the concentration of the main fuel or the combustion improver at which phase separation occurs depends on the temperature of the blended fuel.

[0036] In response to this, it is known that adding a compatibilizer such as a higher alcohol to a fuel mixture can reduce the phase separation tendency of the fuel mixture, for example, lowering the critical dissolution temperature. For example, Figure 3 shows a graph for each temperature of the fuel mixture that shows the relationship between the concentration of methanol, the main fuel in the fuel mixture, and the concentration of dodecanol, the compatibilizer added when the fuel mixture is completely mixed. This graph shows that the closer the main fuel concentration (mixing ratio) is to 50%, the higher the compatibilizer concentration (supply amount) must be, and that the further the main fuel concentration is from 50%, the lower the compatibilizer concentration can be. This graph also shows that the higher the temperature of the fuel mixture, the lower the compatibilizer concentration required for complete mixing of the fuel mixture.

[0037] Therefore, the control device 40 functions as a supply amount determination unit 40a that determines the amount of compatibilizer to be supplied based on the mixture ratio of the main fuel or the combustion improver and the temperature detection result by the temperature detection unit. For example, the supply amount determination unit 40a determines the amount of compatibilizer to be supplied so that the closer the mixture ratio of the main fuel or the combustion improver is to 50%, the greater the supply amount of compatibilizer.

[0038] Furthermore, particularly in this embodiment, the supply amount determination unit 40a determines the amount of compatibilizer to be added to the mixed fuel, i.e., the amount to be supplied by the compatibilizer supply valve 38 (compatibilizer supply unit), based on at least one of the main fuel temperature detection result by the main fuel temperature sensor 41, the combustion improver temperature detection result by the combustion improver temperature sensor 42, and the mixed fuel temperature detection result by the mixed fuel temperature sensor 43. At this time, the supply amount determination unit 40a determines the amount of compatibilizer to be supplied so that the higher the temperature of the main fuel, the combustion improver, or the mixed fuel, the smaller the supply amount of the compatibilizer. Note that the supply amount determination unit 40a may calculate or estimate the temperature of the mixed fuel based on the temperature of the main fuel or the combustion improver.

[0039] As described above, the present invention is applied to an engine system 1 having an engine 2 that runs on a mixed fuel of a main fuel such as ammonia or alcohol and a combustion improver made of a hydrocarbon liquid fuel such as diesel, kerosene, or heavy oil, and a fuel supply device 5 that supplies the mixed fuel to the engine 2 adds a compatibilizer to promote mixing of the main fuel and the combustion improver, thereby generating a mixed fuel.

[0040] As a result, according to the fuel supply device 5 of the present invention, the main fuel and the combustion improver can be mixed at a molecular level by using a compatible solvent, and combustion stability of the mixed fuel can be ensured.

[0041] The fuel supply device 5 of the present invention also includes temperature detection units (main fuel temperature sensor 41, combustion improver temperature sensor 42, and mixed fuel temperature sensor 43) that detect at least one of the temperatures of the main fuel, the combustion improver, and the mixed fuel; a supply amount determination unit 40a of a control device 40 that determines the amount of compatibilizer to be supplied based on the temperature detection results from the temperature detection units; and a compatibilizer supply valve 38 (compatibilizer supply unit) that supplies the amount of compatibilizer determined by the supply amount determination unit 40a. As a result, while the amount of compatibilizer required to mix the main fuel and the combustion improver varies depending on the temperatures of the main fuel, the combustion improver, and the mixed fuel, a relatively simple configuration can supply an appropriate amount of compatibilizer for mixing the main fuel and the combustion improver. This eliminates the need for special devices to maintain the main fuel and the combustion improver at constant temperatures, thereby avoiding a complex and expensive configuration.

[0042] Furthermore, the fuel supply device 5 of the present invention includes a main fuel tank 30 that stores the main fuel, a combustion improver tank 31 that stores the combustion improver, an agitator 34 that agitates the main fuel and the combustion improver, and a stirring tank 33 that is an agitation vessel having the agitator 34, and supplies the main fuel and the combustion improver from the main fuel tank 30 and the combustion improver tank 31 to the stirring tank 33, respectively, and also supplies a determined supply amount of compatibilizer to the stirring tank 33 by a compatibilizer supply valve 38. Thus, with a simple configuration using the agitator 34 and the stirring tank 33, the main fuel and the combustion improver can be mixed using the compatibilizer.

[0043] Furthermore, the fuel supply device 5 of the present invention includes a mixed fuel injection device 35 for supplying the mixed fuel to the engine 2, and the mixed fuel produced by stirring in the stirring tank 33 is supplied to the mixed fuel injection device 35 without being stored in the stirring tank 33. This allows the mixed fuel to be supplied to the mixed fuel injection device 35 and burned in the engine 2 before a change in the temperature of the mixed fuel occurs, so that a good mixed state can be maintained and combustion stability can be ensured without the amount of compatibilizer required for mixing changing due to a change in the temperature of the mixed fuel.

[0044] Furthermore, the fuel supply device 5 of the present invention is provided with a mixed fuel pump 33b that is disposed upstream of the mixed fuel injector 35 and downstream of the agitator tank 33 in the direction of flow of the mixed fuel and that pumps the mixed fuel to the mixed fuel injector 35, and in order to maintain a temperature change of the mixed fuel from the agitator tank 33 to the mixed fuel pump 33b in the flow direction within a predetermined range, the agitator tank 33 is disposed near the mixed fuel pump 33b and / or a heat retention unit 33c is provided in the mixed fuel flow path 33a from the agitator tank 33 to the mixed fuel pump 33b. This allows the mixed fuel to be supplied to the mixed fuel injector 35 and burned in the engine 2 before a change in the temperature of the mixed fuel occurs, and therefore a good mixed state can be maintained and combustion stability can be ensured without a change in the amount of compatibilizer required for mixing due to a change in the temperature of the mixed fuel.

[0045] In the fuel supply device 5 of the present invention, the compatibilizer is a higher alcohol such as dodecanol, n-butanol, i-butanol, pentanol, or octanol, or an ether such as dimethyl ether (DME). By using a compatibilizer suitable for the main fuel and the combustion improver, the fuel and the combustion improver can be mixed more reliably at the molecular level.

[0046] In the above embodiment, an example has been described in which the main fuel flow path 30a and the combustion improver flow path 31a are each connected separately to the stirring tank 33, but the present invention is not limited to this example, and the main fuel flow path 30a and the combustion improver flow path 31a may be joined together and then connected to the stirring tank 33.

[0047] In the above embodiment, the fuel supply device 5 includes the stirring tank 33 as an agitation vessel that stirs and mixes the main fuel and the combustion improver to generate a mixed fuel, but the present invention is not limited to this example. In another example, the fuel supply device 5 may include a fixed mixer 45 such as a static mixer as an agitation vessel, instead of the stirring tank 33 and the agitator 34, as shown in FIG.

[0048] In this case, the fuel supply device 5 is configured so that the main fuel flow path 30a and the combustion improver flow path 31a merge into the mixed fuel flow path 33a, and the fixed mixer 45 is provided in the mixed fuel flow path 33a downstream of the junction of the main fuel flow path 30a and the combustion improver flow path 31a in the flow direction of the mixed fuel. The fixed mixer 45 operates in accordance with the flow of the mixed fuel in the mixed fuel flow path 33a to stir and mix the mixed fuel. Furthermore, the compatibilizer flow path 32a is configured to merge with the mixed fuel flow path 33a downstream of the junction of the main fuel flow path 30a and the combustion improver flow path 31a and upstream of the fixed mixer 45 in the flow direction of the mixed fuel. As a result, the compatibilizer is added to the mixed fuel of the main fuel and the combustion improver, and the mixed fuel of the main fuel, the combustion improver, and the compatible agent is stirred and mixed by the fixed mixer 45.

[0049] Furthermore, the present invention can be modified as appropriate within the scope that does not contradict the gist or concept of the invention that can be read from the claims and the entire specification, and fuel supply devices and engine systems that involve such modifications are also included in the technical concept of the present invention.

[0050] [Appendix to the invention] The following is a summary of the invention extracted from the above-described embodiment. Note that the configurations and processing functions described in the following supplementary notes can be selected and combined as desired.

[0051] <Appendix 1> A fuel supply device that supplies a mixed fuel of a main fuel and a combustion improver made of a hydrocarbon liquid fuel to an engine, A fuel supply device comprising: a compatibilizer; the main fuel; and a combustion improver, and the mixed fuel is produced by mixing the main fuel and the combustion improver.

[0052] <Appendix 2> a temperature detection unit that detects at least one of the temperature of the main fuel, the temperature of the combustion improver, and the temperature of the mixed fuel; a supply amount determination unit that determines the supply amount of the compatibilizer based on the temperature detection result by the temperature detection unit; a compatibilizer supplying unit that supplies the compatibilizer at the supply amount determined by the supply amount determining unit; 2. The fuel supply device according to claim 1, comprising:

[0053] <Appendix 3> a main fuel tank that accommodates the main fuel; a combustion improver tank that accommodates the combustion improver; a mixer that mixes the main fuel and the combustion improver; a stirring vessel having the agitator; 3. The fuel supply device according to claim 2, wherein the main fuel and the combustion improver are supplied from the main fuel tank and the combustion improver tank to the stirring vessel, respectively, and the compatibilizer in the determined supply amount is supplied to the stirring vessel by the compatibilizer supply unit.

[0054] <Appendix 4> a mixed fuel injection device for supplying the mixed fuel to the engine; 4. The fuel supply device according to claim 3, wherein the mixed fuel produced by stirring in the stirring container is supplied to the mixed fuel injection device without being stored in the stirring container.

[0055] <Appendix 5> a mixed fuel pump that is disposed upstream of the mixed fuel injection device and downstream of the agitation container in a flow direction of the mixed fuel, and that pressure-feeds the mixed fuel to the mixed fuel injection device; 5. The fuel supply device according to claim 4, wherein the agitation vessel is disposed in the vicinity of the mixed fuel pump in the flow direction, and / or a heat-retaining section is provided in a flow path from the agitation vessel to the mixed fuel pump.

[0056] <Appendix 6> 6. The fuel supply device according to any one of claims 1 to 5, wherein the main fuel is ammonia or alcohol.

[0057] <Appendix 7> 7. The fuel supply device according to any one of claims 1 to 6, wherein the compatibilizer is a higher alcohol or an ether.

[0058] <Appendix 8> A fuel supply device according to any one of appendices 1 to 7; the engine running on the mixed fuel; An engine system comprising: [Explanation of symbols]

[0059] 1 Engine System 2 engines 3 Intake passage 4 Exhaust passage 5 Fuel supply device 12 cylinders 12a Combustion chamber 18 Intake port 19 Exhaust port 22 Intake manifold 22a Branch channel 23 Exhaust manifold 23a Branch channel 30 Main fuel tank 30a Main fuel passage 31 Combustion improver tank 31a Combustion aid flow path 32 Compatible solvent tank 32a Compatibilizer flow path 33 Mixing Tank 33a Mixed fuel flow path 33b Mixing fuel pump 33c Heat retention part 34 Mixer 35 Mixed fuel injector 36 Main fuel supply valve 37 Combustion improver supply valve 38 Compatibility supply valve 40 Control device 40a Supply amount determination section 41 Main fuel temperature sensor 42 Combustion improver temperature sensor 43 Mixed fuel temperature sensor 45 Fixed mixer

Claims

1. A fuel supply device that supplies a mixed fuel of a main fuel and a combustion improver made of a hydrocarbon liquid fuel to an engine, A fuel supply device comprising: a compatibilizer; the main fuel; and a combustion improver, and the mixed fuel is produced by mixing the main fuel and the combustion improver.

2. a temperature detection unit that detects at least one of the temperature of the main fuel, the temperature of the combustion improver, and the temperature of the mixed fuel; a supply amount determination unit that determines the supply amount of the compatibilizer based on the temperature detection result by the temperature detection unit; a compatibilizer supplying unit that supplies the compatibilizer at the supply amount determined by the supply amount determining unit; 2. The fuel supply device according to claim 1, further comprising:

3. a main fuel tank that accommodates the main fuel; a combustion improver tank that accommodates the combustion improver; a mixer that mixes the main fuel and the combustion improver; a stirring vessel having the agitator; 3. The fuel supply device according to claim 2, wherein the main fuel and the combustion improver are supplied from the main fuel tank and the combustion improver tank to the agitator vessel, respectively, and the determined supply amount of the compatibilizer is supplied to the agitator vessel by the compatibilizer supply unit.

4. a mixed fuel injection device for supplying the mixed fuel to the engine; 4. The fuel supply device according to claim 3, wherein the mixed fuel produced by stirring in the stirring container is supplied to the mixed fuel injection device without being stored in the stirring container.

5. a mixed fuel pump that is disposed upstream of the mixed fuel injection device and downstream of the agitation container in a flow direction of the mixed fuel, and that pressure-feeds the mixed fuel to the mixed fuel injection device; 5. The fuel supply device according to claim 4, wherein the agitator is disposed near the mixed fuel pump in the flow direction, and / or a heat insulating section is provided in a flow path from the agitator to the mixed fuel pump.

6. 2. The fuel supply device according to claim 1, wherein the main fuel is ammonia or alcohol.

7. 2. The fuel supply device according to claim 1, wherein the compatibilizer is a higher alcohol or an ether.

8. The fuel supply device according to claim 1; the engine running on the mixed fuel; An engine system comprising:

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