Engine system

Abstract

To provide an engine system capable of responding to fuel gas containing a toxic substance leaked from an engine.SOLUTION: An engine system 1 having an engine 2 driven by fuel containing a toxic substance includes: a case 7 that surrounds the engine 2; and a fuel detection section 8 disposed inside or outside the case 7 to detect fuel leaked to the outside of the engine 2. When a vapor specific gravity of the fuel is larger than a predetermined threshold value, the fuel is detected by using the fuel detection section 8 disposed in the lower part of the case 7, and when the vapor specific gravity of the fuel is smaller than the predetermined threshold value, the fuel is detected by using the fuel detection section 8 disposed in the upper part of the case 7. The fuel containing the toxic substance is either of ammonia or methanol.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an engine system having an engine that runs on fuel containing toxic substances (deleterious substances as defined in the Poisonous and Deleterious Substances Control Law) such as ammonia and methanol. [Background technology]

[0002] Conventionally, some engines are operated by fuels containing toxic substances such as ammonia, methanol, etc. In engine systems equipped with such engines, there are concerns that the toxic substances contained in the fuel may have adverse effects on the human body, and therefore it is necessary to take measures to remove the toxic substances in order to protect the human body.

[0003] For example, the fuel supply device disclosed in Patent Document 1 includes a fuel supply line that runs from a fuel tank storing any one of liquefied ammonia, liquefied petroleum gas, and methanol to the engine via a recovery tank, and a fuel return line that returns a portion of the fuel from the engine to the recovery tank, with an oil removal and recovery device installed in the fuel return line before reaching the recovery tank or in the recovery tank.The fuel supply device also includes a gas-liquid separator that introduces fuel into the fuel return line that returns a portion of the fuel from the engine to the recovery tank and separates it into vaporized ammonia gas, liquefied ammonia, and oil, and a detoxification device that introduces the vaporized ammonia gas and water separated by the gas-liquid separator and produces ammonia water. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-055419 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional engine systems are provided with an exclusion device to remove toxic substances such as ammonia, but the exclusion device is expensive, which increases costs, and the configuration required to provide the exclusion device may complicate the structure of the engine system. Furthermore, conventional engine systems can remove toxic substances such as ammonia in the fuel supply device, as in Patent Document 1, but cannot deal with fuel gas containing toxic substances that leaks from the engine.

[0006] An object of the present invention is to provide an engine system that can deal with fuel gas containing toxic substances leaking from the engine. [Means for solving the problem]

[0007] In order to solve the above problem, the engine system of the present invention is an engine system having an engine that runs on fuel containing toxic substances, comprising a case that encloses the engine, and a fuel detection unit that is arranged inside or outside the case and detects the fuel that has leaked outside the engine, characterized in that if the vapor density of the fuel is greater than a predetermined threshold, the fuel is detected using the fuel detection unit arranged at the bottom of the case, and if the vapor density of the fuel is less than the predetermined threshold, the fuel is detected using the fuel detection unit arranged at the top of the case. [Effects of the Invention]

[0008] According to the present invention, an engine system is provided that can deal with fuel gas containing toxic substances leaking from the engine. [Brief explanation of the drawings]

[0009] [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 schematic diagram illustrating an example of a cylinder of an engine in an engine system according to an embodiment of the present invention. [Figure 3]1 is a schematic diagram illustrating an example of an engine system according to an embodiment of the present invention. [Figure 4] FIG. 4 is a schematic diagram illustrating another example of an engine system according to an embodiment of the present invention. [Figure 5] FIG. 4 is a schematic diagram illustrating another example of an engine system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] An engine system 1 according to an embodiment of the present invention will be described with reference to the drawings. As shown in Figures 1 and 3, the engine system 1 includes an engine 2, an intake passage 3, an exhaust passage 4, a fuel supply path 5, a supercharger 6, a case 7, a fuel detection unit 8, a notification unit 9, and a control unit 10.

[0011] Particularly in this embodiment, the engine system 1 operates by feeding fuel containing toxic substances (deleterious substances under the Poisonous and Deleterious Substances Control Act) such as ammonia and methanol into the combustion chamber 21a of the engine 2. The fuel is supplied to the combustion chamber 21a as a mixture with air (fuel gas). The engine system 1 is installed in a building, a housing, or a mobile body (for example, a car, a ship, or an aircraft).

[0012] The engine 2 is, for example, a four-stroke engine, and is configured by including a plurality of cylinders 21 in a cylinder block 20 and a crankcase 22. Although six cylinders 21 are shown in FIGS. 1 and 3, the number of cylinders 21 is not limited to six. FIG. 2 shows only one of the plurality of cylinders 21. As shown in FIGS. 1, 3, and 2, the cylinder 21 is configured by a cylinder 23, a piston 24, and a cylinder head 25.

[0013] The cylinder 23 is formed, for example, in a cylindrical shape within the cylinder block 20, and the piston 24 is slidably housed within the cylinder 23. The cylinder head 25 is attached to the upper side of the cylinder 23, and a combustion chamber 21a is formed inside the cylinder 23 and the cylinder head 25. As shown in FIG. 2, the cylinder head 25 is provided with an ignition device 26 that ignites fuel within the combustion chamber 21a. The ignition device 26 may be configured as a micro-pilot device that injects a small amount of liquid fuel, or may be configured as a spark ignition device using an ignition plug. Furthermore, the ignition device may be configured to compress and ignite a mixture of gaseous fuel and liquid fuel.

[0014] Each cylinder 23 of the multiple cylinders 21 is connected to a crankcase 22, and a crankshaft 27 (crank shaft) is rotatably supported by the crankcase 22. A piston 24 of each cylinder 21 is connected to the crankshaft 27 via a connecting rod 28, and the reciprocating motion of the piston 24 is converted into the rotational motion of the crankshaft 27 via the connecting rod 28. In addition, the crankcase 22 is provided with an explosion-proof valve 22a (pressure valve) to release the internal pressure, since an explosion and damage may occur if the internal pressure exceeds a certain level.

[0015] 2, the cylinder head 25 has an intake port 29 communicating with the combustion chamber 21a and an intake valve 30 that opens and closes the intake port 29. The combustion chamber 21a is connected to an intake passage 3 via the intake port 29, and an air-fuel mixture (fuel gas) supplied from the intake passage 3 is introduced into the combustion chamber 21a. The cylinder head 25 also has an exhaust port 31 communicating with the combustion chamber 21a and an exhaust valve 32 that opens and closes the exhaust port 31. The combustion chamber 21a is connected to an exhaust passage 4 via the exhaust port 31, and exhaust gas generated in the combustion chamber 21a is discharged into the exhaust passage 4.

[0016] In order to connect the intake passage 3 to the multiple cylinders 21, an intake manifold 33 having branch intake passages 33a branching from the intake passage 3 to each of the intake ports 29 of the multiple cylinders 21 is provided between the intake passage 3 and the engine 2. In addition, in order to connect the exhaust passage 4 to the multiple cylinders 21, an exhaust manifold 34 having branch exhaust passages 34a branching from the exhaust passage 4 to the multiple cylinders 21 is provided between the exhaust passage 4 and the engine 2. In Figures 1 and 3, the intake manifold 33 is indicated by a dashed line, and the exhaust manifold 34 is indicated by a dashed line.

[0017] The intake passage 3 is connected to a plurality of cylinders 21 of the engine 2 and supplies compressed and cooled air to each cylinder 21. A mixture of air supplied from the intake passage 3 and fuel containing toxic substances supplied from a fuel tank (not shown) via a fuel supply path 5 is supplied to the combustion chamber 21a of each cylinder 21. A supercharger 6 is provided upstream in the intake direction in the intake passage 3, which compresses air or a mixture of fuel and air flowing through the intake passage 3 and sends it downstream in the intake direction. The intake passage 3 may be provided with an air filter (not shown) that purifies fresh air and introduces it into the intake passage 3, and an intercooler (not shown) that cools the air flowing through the intake passage 3.

[0018] The exhaust passage 4 is connected to a plurality of cylinders 21 of the engine 2, and allows exhaust gas generated in each cylinder 21 to flow and be discharged.

[0019] The fuel supply path 5 supplies fuel from a fuel tank (not shown) to the engine 2. For example, the fuel supply path 5 has a plurality of branched fuel paths 5a that branch off to distribute fuel toward each of the plurality of cylinders 21, and a plurality of main fuel supply devices 35 that are provided at the respective ends of the plurality of branched fuel paths 5a to supply fuel to each combustion chamber 21a of the plurality of cylinders 21. The main fuel supply devices 35 are formed, for example, by a gas admission valve or a gas injector. For example, the plurality of main fuel supply devices 35 are arranged to inject fuel into a plurality of branched intake flow paths 33a of an intake manifold 33 that is provided for each of the plurality of cylinders 21.

[0020] The turbocharger 6 compresses the air or air-fuel mixture flowing through the intake passage 3 and sends it downstream in the intake direction. The turbocharger 6 has a turbine 6a and a compressor 6b. The turbine 6a is disposed in the exhaust passage 4, and the compressor 6b is disposed in the intake passage 3. The turbine 6a is rotated by the exhaust gas flowing through the exhaust passage 4, and the rotational force of the turbine 6a drives the compressor 6b, thereby compressing the air or air-fuel mixture flowing through the intake passage 3.

[0021] The case 7 is arranged in a building, a housing, or a mobile body in which the engine system 1 is installed, and is configured to enclose the engine 2.

[0022] For example, the case 7 is configured to have a plurality of plate members made of steel plates that surround the engine 2 from various directions (front-rear, left-right, up-down, diagonal directions relative to these, etc.), and these plate members tightly cover the engine 2. This allows the case 7 to have high airtightness and improves the controllability of the internal pressure. The case 7 may also be configured to have steel beam members or pillar members that support the plate members.

[0023] Alternatively, the case 7 may be configured to cover the engine 2 by including a sheet-like member or a hood-like member supported on a beam member or a pillar member instead of or in addition to the plate member.

[0024] Alternatively, the case 7 may be configured by arranging a plurality of plate members, sheet-like members, or hood-like members with gaps therebetween, or by arranging only one plate member. This allows the case 7 to have airtightness according to the state of the engine 2 and fuel, and can be configured at low cost. The case 7 may also be configured by arranging lattice members supported by beam members or pillar members, or may be configured by arranging only beam members or pillar members.

[0025] The case 7 also has an intake port 40 for taking in air to be supplied to the engine 2 from the outside of the case 7, and an exhaust port 41 for discharging exhaust gas emitted from the engine 2 to the outside of the case 7. The case 7 also has a ventilation inlet 42 for introducing ventilation air from the outside to the inside of the case 7 in order to ventilate the inside of the case 7, and a ventilation outlet 43 for discharging the ventilation air that has ventilated the inside of the case 7 to the outside of the case 7.

[0026] The air intake 40 or the ventilation inlet 42 and the air exhaust 41 are arranged independently, for example, spaced apart by a predetermined distance or more, and / or having different opening directions. In particular, the air intake 40 or the ventilation inlet 42 and the air exhaust 43 are arranged independently, for example, spaced apart by a predetermined distance or more, and / or having different opening directions.

[0027] A ventilation introduction passage 44 is connected to the ventilation inlet 42, and the ventilation introduction passage 44 communicates from the ventilation inlet 42, which leads to the inside of the case 7, to the outside of the case 7. Ventilation air is introduced from the outside of the case 7 into the inside of the case 7 through the ventilation introduction passage 44 and the ventilation inlet 42.

[0028] A ventilation exhaust passage 45 is connected to the ventilation outlet 43, and the ventilation exhaust passage 45 communicates from the ventilation outlet 43, which leads to the inside of the case 7, to the outside of the building, housing, or mobile body in which the engine 2 is installed. The ventilation exhaust passage 45 is configured to be sealed except for both ends including the ventilation outlet 43, and is structured so that the exhausted ventilation air does not leak midway. The ventilation air is exhausted from the inside of the case 7 through the ventilation outlet 43 and the ventilation exhaust passage 45 to the outside of the building, housing, or mobile body.

[0029] The case 7 is also provided with a ventilation fan 46 in the ventilation outlet 43 or the ventilation exhaust passage 45, and the ventilation fan 46 is configured to operate under the control of the control unit 10 and suck in ventilation air inside the case 7 and exhaust it from the ventilation outlet 43 or the ventilation exhaust passage 45. The case 7 may be provided with one ventilation fan 46, or may be provided with two or more ventilation fans 46. For example, the ventilation fan 46 is controlled by the control unit 10 so as to operate at all times while the engine 2 is running. The ventilation fan 46 may be configured to change its operating strength, i.e., its suction strength, in response to control by the control unit 10.

[0030] As an example of case 7 configured to include a gap, when fuel gas having a vapor density less than 1 (a predetermined threshold) is used as the fuel-air mixture supplied to combustion chamber 21a, case 7 may be configured by arranging a plate member so as to have a gap at the bottom. In this case, air intake 40 and ventilation inlet 42 may be provided at the bottom of case 7 or in the gap so as to introduce air from below or around the bottom of case 7, and ventilation outlet 43 may be provided at the top of case 7 so as to exhaust air above or around the top of case 7.

[0031] Furthermore, when a fuel gas having a vapor density greater than 1 (a predetermined threshold) is used as the fuel-air mixture supplied to the combustion chamber 21a, the case 7 may be configured by arranging a plate member so as to have a gap at the top. In this case, the air intake 40 and the ventilation inlet 42 may be provided at the top of the case 7 so as to introduce air from above the case 7 or from around the upper part, and the ventilation outlet 43 may be provided at the bottom of the case 7 so as to discharge air downward or around the lower part.

[0032] Furthermore, as an example of the shape of the case 7, when fuel gas having a vapor density of less than 1 is used as the fuel-air mixture supplied to the combustion chamber 21a, the case 7 is configured with a roof portion made of a plate member with a height difference on the upper part of the case 7. This creates a density difference inside the upper part of the case 7, and by utilizing the rising of air due to this density difference, it is possible to prevent air convection and efficiently ventilate fuel gas leaking from the engine 2. In this case, the ventilation outlet 43 is preferably provided at the top of the roof portion of the case 7 so as to discharge air above the case 7 or around the upper part. Specifically, the case 7 has a roof portion shaped like an isosceles triangle or a right triangle.

[0033] Furthermore, when fuel gas having a vapor density greater than 1 is used as the fuel-air mixture supplied to the combustion chamber 21a, the case 7 is configured to include a receiving portion such as a pit (groove) or a tray on or above the bottom surface of the inside of the case 7. This allows the receiving portion on the inside of the lower part of the case 7 to receive fuel gas leaking from the engine 2, making it easier to discharge the fuel gas and preventing fuel gas from accumulating, thereby enabling efficient ventilation. In this case, the ventilation outlet 43 is preferably provided below the case 7 or at the lowest part of the roof of the case 7 so as to discharge air around the lower part. Note that by arranging the receiving portion at an angle, the case 7 makes it easier to discharge the fuel gas received by the receiving portion, preventing fuel gas from accumulating, and enabling efficient ventilation.

[0034] The fuel detection unit 8 is disposed inside or outside the case 7 and detects fuel gas leaked outside the engine 2. The fuel detection unit 8 may be configured with a sensor that detects the amount or concentration of toxic substances (ammonia, methanol, etc.) in the surrounding air and detects fuel gas based on the detection results. Alternatively, the fuel detection unit 8 may be configured with a sensor that detects environmental information such as the temperature and pressure of the surrounding air and detects fuel gas based on changes in the environmental information, etc.

[0035] As an example of the location of the fuel detection unit 8, when a fuel gas having a vapor specific gravity greater than 1 is used as the fuel-air mixture supplied to the combustion chamber 21a, the fuel detection unit 8 is located in the lower part of the case 7 as shown in Fig. 1 in order to detect the fuel gas that has descended to the lower part of the case 7. For example, as an example of the location of the lower part of the case 7, the fuel detection unit 8 may be located near the bottom surface inside the case 7, such as on or above the bottom surface, or may be located outside the case 7, below or to the side of the lower part.

[0036] Furthermore, when a fuel gas having a vapor density smaller than 1 is used as the fuel-air mixture supplied to the combustion chamber 21a, the fuel detection unit 8 is disposed in the upper part of the case 7, as shown in Fig. 3, in order to detect the fuel gas that has risen to the upper part of the case 7. For example, the fuel detection unit 8 may be disposed inside the case 7 near the ceiling surface, such as below the ceiling surface or below the ceiling surface, or may be disposed outside the case 7 above or to the side of the upper part.

[0037] The alarm unit 9 issues an alarm for an abnormality occurring in the engine system 1 by sound such as a buzzer or light such as a lamp. The alarm unit 9 may be configured to issue an alarm by sound and / or light according to control by the control unit 10. The alarm unit 9 may change the length, interval, and size of the sound or light according to the type of abnormality, i.e., the type of alarm. The alarm unit 9 may be provided with multiple lamps at various positions, and may light up the lamp at the position where the abnormality has occurred.

[0038] The control unit 10 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 unit 10 may store various programs for controlling the engine 2, and control the engine 2 by reading and executing the programs.

[0039] In particular, the control unit 10 controls each section to take action against the leak in accordance with a predetermined condition, for example, when the fuel detection section 8 detects a fuel gas leak from the engine 2. For example, when the control unit 10 detects a fuel gas leak, the control unit 10 controls the alarm section 9 to issue an alarm corresponding to the fuel detection. At this time, the control unit 10 causes the alarm section 9 to issue an alarm that identifies the fuel detection by sound and / or light. Note that the control unit 10 may issue a different alarm depending on the position of the fuel detection section 8 that detected the fuel, or may cause the alarm section 9 located at a position corresponding to the position of the fuel detection section 8 to issue an alarm.

[0040] Furthermore, when a fuel gas leak is detected, the control unit 10 controls the ventilation fans 46 provided in the ventilation outlet 43 or the ventilation exhaust passage 45 of the case 7 so as to operate in response to fuel detection. In this case, the control unit 10 may control the ventilation fans 46, which always operate while the engine 2 is running, to operate at a relatively low intensity when no fuel is detected and to operate at a relatively high intensity when fuel is detected. Furthermore, when multiple ventilation fans 46 are provided, the control unit 10 may control some of the ventilation fans 46 to stop when no fuel is detected and to increase the number of ventilation fans 46 to operate when fuel is detected.

[0041] Furthermore, the control unit 10 may determine in stages the detection result of the fuel gas by the fuel detection unit 8 (for example, the concentration or the amount per unit time), and may control the ventilation fans 46 in stages according to the determination result. For example, the control unit 10 may control the ventilation fans 46 so that the operating intensity is stronger or the number of operating ventilation fans 46 is increased as the concentration or amount of fuel gas increases.

[0042] As described above, according to this embodiment, the engine system 1 equipped with the engine 2 that runs on fuel containing toxic substances includes a case 7 that encloses the engine 2, and a fuel detection unit 8 that is arranged inside or outside the case 7 and detects fuel that has leaked outside the engine 2. If the vapor density of the fuel is greater than a predetermined threshold (for example, 1), the fuel is detected using the fuel detection unit 8 arranged at the bottom of the case 7, and if the vapor density of the fuel is less than the predetermined threshold (for example, 1), the fuel is detected using the fuel detection unit 8 arranged at the top of the case 7. The fuel containing toxic substances is either ammonia or methanol.

[0043] As a result, the engine system 1 can use the case 7 to prevent the fuel (fuel gas) leaking from the engine 2 and containing toxic substances from diffusing outside the engine system 1. Furthermore, the engine system 1 can detect the fuel leaking from the engine 2 and containing toxic substances using the fuel detection unit 8, thereby enabling quick action to be taken against the fuel leak.

[0044] According to this embodiment, the engine system 1 is provided with an intake port 40 for drawing in air to be supplied to the engine 2 from outside the case 7, and a ventilation outlet 43 arranged independently of the intake port 40 for ventilating the inside of the case 7 and discharging the air to the outside of the case 7.

[0045] This makes it possible to prevent toxic substances leaked from the engine 2 from being mixed into air other than the fuel supplied to the engine 2. In conventional generator packages and the like to which an engine system is applied, the engine's air intake port generally doubles as a ventilation port (ventilator), but in this case, there is a risk that fuel (gas) containing toxic substances leaked from the engine may leak from the ventilation port into a space outside the engine system where people are present. In contrast, in this embodiment, fuel containing toxic substances leaked from the engine 2 is discharged from the ventilation outlet 43 to a space different from the air intake port 40, and is therefore not discharged into a space outside the engine system 1 where people are present.

[0046] According to this embodiment, the engine system 1 is provided with a ventilation exhaust passage 45 that connects from a ventilation outlet 43 that leads to the inside of the case 7 to the outside of the building, housing, or mobile body in which the engine 2 is installed, and the ventilation exhaust passage 45 is configured to be sealed except for both ends including the ventilation outlet 43.

[0047] As a result, the ventilation exhaust passage 45 is structured so that the exhaust ventilation air does not leak midway, and fuel containing toxic substances leaked from the engine 2 can be safely guided to a place away from the engine system 1 where no one is present.

[0048] According to this embodiment, the engine system 1 includes a notification unit 9 that issues a warning in response to the detection of fuel by the fuel detection unit 8.

[0049] As a result, if fuel containing toxic substances leaks from the engine 2, an alarm can be issued to notify the driver of the danger and prompt the driver to take measures to deal with the leakage.

[0050] According to this embodiment, the engine system 1 includes a ventilation fan 46 that operates in response to the fuel detection by the fuel detection unit 8.

[0051] This allows the ventilation fan 46 to be automatically activated in the event of a leak of fuel containing toxic substances from the engine 2, thereby ensuring safety from toxic substances for people outside the engine system 1.

[0052] In the above embodiment, an example has been described in which the fuel detection unit 8 is disposed in the lower part of the case 7 when a fuel gas having a vapor density greater than 1 is used in the engine system 1, and the fuel detection unit 8 is disposed in the upper part of the case 7 when a fuel gas having a vapor density less than 1 is used, but the present invention is not limited to this example. For example, the fuel detection unit 8 may be disposed in both the upper and lower parts of the case 7, and the engine system 1 may switch between using the fuel detection unit 8 disposed in the upper part and the fuel detection unit 8 disposed in the lower part depending on the vapor density of the fuel gas used.

[0053] In the engine system 1, the fuel detection unit 8 may be disposed at other positions in addition to or instead of the upper and / or lower parts of the case 7.

[0054] 4, the fuel detection unit 8 may be disposed near the crankshaft 27 of the engine 2 in order to detect fuel (fuel gas) containing toxic substances that has leaked outside the engine 2 and near the crankshaft 27 of the engine 2. In this case, the fuel detection unit 8 is preferably disposed so as to detect the fuel containing toxic substances before the fuel fills the inside of the case 7. Specifically, the fuel detection unit 8 may be disposed by being attached to the crankcase 22 near the axial hole of the crankshaft 27 in the crankcase 22, or may be disposed away from the crankcase 22.

[0055] In engine 2 that uses fuel containing toxic substances, the blow-by gas generated inside crankcase 22 also contains toxic substances. In the axial hole of crankcase 22, crankshaft 27 is sometimes supported via an oil seal such as a labyrinth seal without being sealed, and blow-by gas inside crankcase 22 may leak from the axial hole of crankshaft 27. In response to this, engine system 1 can detect fuel containing toxic substances using fuel detection unit 8 located near crankshaft 27, making it possible to deal with the case where fuel containing toxic substances leaks from near crankshaft 27.

[0056] 5, the fuel detection unit 8 may be disposed near the explosion-proof valve 22a in order to detect fuel (fuel gas) containing toxic substances that has leaked outside the engine 2 and near the explosion-proof valve 22a of the engine 2. In this case, the fuel detection unit 8 is preferably disposed so as to be able to detect the fuel containing toxic substances before the fuel fills the inside of the case 7. Specifically, the fuel detection unit 8 may be disposed near the explosion-proof valve 22a of the crankcase 22 and attached to the crankcase 22, or may be disposed apart from the crankcase 22.

[0057] The explosion-proof valve 22a of the crankcase 22 opens when the internal pressure of the crankcase 22 increases, which can cause blow-by gas inside the crankcase 22 to leak through the explosion-proof valve 22a. In response to this, the engine system 1 can detect fuel containing toxic substances using the fuel detection unit 8 located near the explosion-proof valve 22a, making it possible to deal with cases in which fuel containing toxic substances leaks from near the explosion-proof valve 22a.

[0058] In the above embodiment, in the engine system 1, when the fuel detection unit 8 detects fuel containing toxic substances, an example of leak countermeasures is described in which the notification unit 9 issues an alarm or the ventilation fan 46 is activated. However, the present invention is not limited to this example. For example, the engine system 1 may take measures to counter leaks, such as emergency stopping or deceleration of the engine 2. Furthermore, if the engine 2 is configured as a dual-fuel engine, the engine system 1 may control the engine 2 to operate while reducing the amount of fuel containing toxic substances used as a leak countermeasure. The control unit 10 may determine the detection result of the fuel gas by the fuel detection unit 8 in stages and control the use of the various leak countermeasures described above depending on the determination result.

[0059] In the present invention, the fuel containing a toxic substance (a deleterious substance as defined in the Poisonous and Deleterious Substances Control Law) refers to a fuel containing a toxic substance such as ammonia or methanol.

[0060] 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 engine systems involving such modifications are also included in the technical concept of the present invention.

[0061] [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.

[0062] <Appendix 1> 1. An engine system having an engine that runs on a fuel containing a toxic substance, a case that encloses the engine; a fuel detection unit disposed inside or outside the case and configured to detect the fuel leaking to the outside of the engine; Equipped with If the vapor density of the fuel is greater than a predetermined threshold, the fuel is detected using the fuel detection unit disposed in the lower part of the case; An engine system characterized in that, when the vapor density of the fuel is lower than a predetermined threshold, the fuel is detected using the fuel detection unit arranged on an upper part of the case.

[0063] <Appendix 2> an intake port for drawing air to be supplied to the engine from outside the case; a ventilation outlet that is arranged independently of the intake port and that ventilates the inside of the case and discharges the vent to the outside of the case; 2. The engine system according to claim 1, comprising:

[0064] <Appendix 3> a ventilation exhaust passage communicating from the ventilation outlet leading to the inside of the case to the outside of a building, a housing, or a mobile body in which the engine is installed; The engine system described in Appendix 2, wherein the ventilation exhaust passage is configured to be sealed except for both ends including the ventilation outlet.

[0065] <Appendix 4> 4. The engine system according to any one of claims 1 to 3, further comprising the fuel detection unit that detects the fuel leaking outside the engine and near a crankshaft of the engine.

[0066] <Appendix 5> 5. The engine system according to any one of claims 1 to 4, further comprising the fuel detection unit that detects the fuel leaked outside the engine and near an explosion-proof valve of the engine.

[0067] <Appendix 6> 6. The engine system according to any one of claims 1 to 5, further comprising an alarm unit that issues an alarm in response to the detection of the fuel by the fuel detection unit.

[0068] <Appendix 7> 7. The engine system according to any one of claims 1 to 6, further comprising a ventilation fan that operates in response to the detection of the fuel by the fuel detection unit.

[0069] <Appendix 8> 8. The engine system according to any one of claims 1 to 7, wherein the fuel is either ammonia or methanol. [Explanation of symbols]

[0070] 1 Engine System 2 engines 3 Intake passage 4 Exhaust passage 5 Fuel supply route 6. Turbocharger 7 Cases 8 Fuel detection unit 9. Information Department 10. Control Unit 20 Cylinder block 21 cylinders 21a Combustion chamber 22 Crankcase 22a Explosion-proof valve 23 cylinders 24 pistons 25 cylinder head 26 Ignition system 27 crankshaft 28 Connecting rod 29 Intake port 30 Intake valve 31 Exhaust port 32 Exhaust valve 33 Intake manifold 34 Exhaust manifold 35 Main fuel supply system 40 Air intake 41 Exhaust port 42 Ventilation inlet 43 Ventilation outlet 44 Ventilation intake passage 45 Ventilation exhaust passage 46 Ventilation fan

Claims

1. 1. An engine system having an engine that runs on a fuel containing a toxic substance, a case that encloses the engine; a fuel detection unit disposed inside or outside the case and configured to detect the fuel leaking to the outside of the engine; Equipped with If the vapor density of the fuel is greater than a predetermined threshold, the fuel is detected using the fuel detection unit disposed in the lower part of the case; An engine system characterized in that, when the vapor density of the fuel is lower than a predetermined threshold, the fuel is detected using the fuel detection unit arranged on an upper part of the case.

2. an intake port for drawing air to be supplied to the engine from outside the case; a ventilation outlet that is arranged independently of the intake port and that ventilates the inside of the case and discharges the vent to the outside of the case; The engine system according to claim 1, further comprising:

3. a ventilation exhaust passage communicating from the ventilation outlet leading to the inside of the case to the outside of a building, a housing, or a mobile body in which the engine is installed; The engine system according to claim 2 , wherein the ventilation exhaust passage is sealed except for both ends including the ventilation outlet.

4. 2. The engine system according to claim 1, further comprising: the fuel detection unit for detecting the fuel leaking outside the engine and near a crankshaft of the engine.

5. 2. The engine system according to claim 1, further comprising: the fuel detection unit for detecting the fuel leaked outside the engine and near an explosion-proof valve of the engine.

6. 2. The engine system according to claim 1, further comprising an alarm unit that issues an alarm in response to the detection of the fuel by the fuel detection unit.

7. 2. The engine system according to claim 1, further comprising a ventilation fan that operates in response to the detection of the fuel by the fuel detection unit.

8. 2. The engine system according to claim 1, wherein the fuel is one of ammonia and methanol.

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