Gas engine

Abstract

To provide a gas engine capable of supplying a large volume of hydrogen to a combustion chamber and suppressing increase in manufacturing cost.SOLUTION: A gas engine that burns fuel gas including hydrogen in a combustion chamber includes: an intake line in which an intake flow passage is formed, the intake flow passage including an intake port opened in the combustion chamber; a fuel supply line provided separately from the intake line, the fuel supply line having a fuel flow passage in which fuel gas flows toward the combustion chamber and an outlet of the fuel flow passage opened in the combustion chamber; a solenoid valve provided in the fuel supply line to open / close the fuel flow passage; and a check valve provided on the combustion chamber side in the fuel supply line of the solenoid valve to open / close the fuel flow passage by using differential pressure between the fuel flow passage and the combustion chamber.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a gas engine that burns fuel gas containing hydrogen in a combustion chamber. [Background technology]

[0002] Patent Document 1 discloses a gas engine that mixes fuel gas with air flowing through an intake line and supplies this mixture to a combustion chamber. Hydrogen has a faster combustion speed than other components such as methane and propane. Therefore, when a fuel gas containing hydrogen is used in a gas engine such as that disclosed in Patent Document 1, there is a possibility of backfire, in which a flame penetrates the intake line. Patent Document 2 discloses a gas engine that includes an injector that is provided separately from the intake line and injects fuel gas into the combustion chamber. A gas engine such as that described in Patent Document 2 can suppress the occurrence of backfire. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-299592 [Patent Document 2] Japanese Patent Application Publication No. 7-189848 Summary of the Invention [Problem to be solved by the invention]

[0004] However, because the injection pressure of hydrogen is low, a large injector is required to increase the amount of hydrogen supplied to the combustion chamber, which increases the manufacturing costs of the gas engine.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a gas engine that is capable of supplying large amounts of hydrogen to the combustion chamber while suppressing increases in manufacturing costs. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the gas engine of the present disclosure is a gas engine that burns fuel gas containing hydrogen in a combustion chamber, and is equipped with an intake line having an intake passage formed therein, the intake line including an intake port where the intake passage opens into the combustion chamber, a fuel supply line provided separately from the intake line, the fuel supply line having a fuel passage formed therein through which the fuel gas flows toward the combustion chamber, the outlet of the fuel passage opening into the combustion chamber, an electromagnetic valve provided in the fuel supply line and opening and closing the fuel passage, and a check valve provided on the combustion chamber side of the fuel supply line relative to the electromagnetic valve and opening and closing the fuel passage depending on the pressure difference between the fuel passage and the combustion chamber. [Effects of the Invention]

[0007] According to the gas engine of the present disclosure, it is possible to supply a large amount of hydrogen to the combustion chamber, and it is possible to suppress an increase in manufacturing costs. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing a schematic configuration of a gas engine according to a first embodiment. [Figure 2] 4 is a diagram for explaining the opening and closing periods of the solenoid valve according to the first embodiment. FIG. [Figure 3A] 10A and 10B are diagrams illustrating periods during which a solenoid valve is opened and closed according to some embodiments. [Figure 3B] 10A and 10B are diagrams illustrating periods during which a solenoid valve is opened and closed according to some embodiments. [Figure 4] 3 is a graph showing the relationship between crank angle and pressure in the gas engine according to the first embodiment. [Figure 5] FIG. 4 is a diagram schematically showing the configuration of a gas engine according to a second embodiment. [Figure 6] 10 is a diagram for explaining the opening and closing periods of the solenoid valve for leakage according to the second embodiment. FIG. [Figure 7] 6 is a graph showing the relationship between crank angle and pressure in a gas engine according to a second embodiment. [Figure 8A] 1 is a diagram illustrating a schematic configuration of a gas engine according to some embodiments. [Figure 8B] 1 is a diagram illustrating a schematic configuration of a gas engine according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0009] A gas engine according to an embodiment of the present disclosure will be described below with reference to the drawings. The embodiment shows one aspect of the present disclosure, but does not limit the present disclosure and can be modified as desired within the scope of the technical concept of the present disclosure.

[0010] First Embodiment (composition) A gas engine 1 according to the present disclosure combusts a fuel gas F containing hydrogen in a combustion chamber 3. Fig. 1 is a diagram showing a schematic configuration of a gas engine 1 according to a first embodiment.

[0011] In this disclosure, "fuel gas F containing hydrogen" includes those containing hydrogen and fuels other than hydrogen (mixed combustion) and those containing only hydrogen (monocarbon combustion). Furthermore, those containing hydrogen and fuels other than hydrogen can be classified into those in which hydrogen is the main fuel (volume ratio of hydrogen is 50% or more) and those in which a fuel other than hydrogen is the main fuel (volume ratio of hydrogen is less than 50%). "Fuel gas F containing hydrogen" includes all of these cases.

[0012] First, a description will be given of the combustion chamber 3. As shown in FIG.

[0013] The cylinder liner 31 has a cylindrical shape. In the first embodiment, the cylinder liner 31 extends in the vertical direction and opens upward. The cylinder liner 31 is fitted inside a cylindrical cylinder block (not shown).

[0014] The piston 32 is housed inside the cylinder liner 31. In the first embodiment, the piston 32 has an upper surface 34 that is recessed downward toward the central axis C of the cylinder liner 31. The piston 32 is configured to be able to reciprocate up and down inside the cylinder liner 31.

[0015] The cylinder head 33 covers the opening of the cylinder liner 31. In the first embodiment, the cylinder head 33 is disposed above the cylinder liner 31. The cylinder head 33 is fixed to a cylinder block (not shown).

[0016] The combustion chamber 3 is defined between a piston 32 and a cylinder head 33 in a cylinder liner 31. An intake port 35 that opens into the combustion chamber 3 is formed in the cylinder head 33. The combustion chamber 3 is configured so that air A1 is supplied to it via the intake port 35. Similarly, the cylinder head 33 is formed with an exhaust port 37 that opens into the combustion chamber 3, separate from the intake port 35. The combustion chamber 3 is configured so that exhaust gas A2 generated by combustion of the fuel gas F is discharged from the combustion chamber 3 via the exhaust port 37. The intake port 35 is opened and closed by an intake valve 36. The exhaust port 37 is opened and closed by an exhaust valve 38.

[0017] The configuration of a gas engine 1 according to the present disclosure will be described. As shown in Fig. 1, the gas engine 1 includes an intake line 2, a fuel supply line 4, a solenoid valve 6, a check valve 8, and a control device 10.

[0018] An intake passage 5 is formed inside the intake line 2. The intake line 2 has an inlet of the intake passage 5 that is open to the atmosphere, allowing air to be taken in from outside the gas engine 1. The air taken into the intake line 2 flows through the intake passage 5 toward the combustion chamber 3. The intake passage 5 includes the intake port 35 described above as an outlet of the intake passage 5.

[0019] The fuel supply line 4 is provided separately from the intake line 2, and has a fuel flow path 7 formed therein through which the fuel gas F flows toward the combustion chamber 3. In the first embodiment, the fuel supply line 4 is connected to a fuel supply source 12 in which the fuel gas F is stored. The fuel supply line 4 includes a fuel port 39 formed in the cylinder head 33 as an outlet of the fuel flow path 7. The fuel port 39 (the outlet of the fuel flow path 7) opens to the combustion chamber 3.

[0020] The solenoid valve 6 is provided in the fuel supply line 4. The solenoid valve 6 opens and closes the fuel flow path 7. Specifically, the solenoid valve 6 is electrically connected to the control device 10, and opens and closes the fuel flow path 7 in accordance with instructions transmitted from the control device 10.

[0021] The check valve 8 is provided on the combustion chamber 3 side of the fuel supply line 4 relative to the solenoid valve 6. The check valve 8 opens and closes the fuel flow path 7 according to the pressure difference between the fuel flow path 7 and the combustion chamber 3. The check valve 8 is configured to allow only a forward flow from the fuel flow path 7 to the combustion chamber 3 and not allow a reverse flow. In the first embodiment, the check valve 8 is provided in the fuel port 39. The pressure inside the combustion chamber 3 is defined as an in-cylinder pressure P1, the pressure in a portion of the fuel flow path 7 between the solenoid valve 6 and a compressor 14 (described below) (hereinafter referred to as an upstream portion 11) is defined as a solenoid valve upstream pressure P2, and the pressure in a portion of the fuel flow path 7 between the solenoid valve 6 and the check valve 8 (hereinafter referred to as a downstream portion 13) is defined as a solenoid valve downstream pressure P3. The check valve 8 opens and closes the fuel flow path 7 according to the pressure difference between the in-cylinder pressure P1 and the solenoid valve downstream pressure P3. In the present disclosure, the check valve 8 is described as opening when the solenoid valve downstream pressure P3 - cylinder internal pressure P1 > 0.

[0022] The control device 10 is a computer such as an electronic control device, and includes a processor such as a CPU or GPU (not shown), memories such as a ROM or RAM, and an I / O interface. The processor of the control device 10 operates (performs calculations, etc.) according to instructions of a program loaded into the memory, thereby realizing each of the functional units of the control device 10. In some embodiments, the control device 10 is a cloud server provided in a cloud environment.

[0023] An example of control of the solenoid valve 6 by the control device 10 will be described. FIG. 2 is a diagram for explaining the opening and closing periods of the solenoid valve 6 according to the first embodiment. The control device 10 transmits a valve open command to the solenoid valve 6 after the intake stroke start timing TIs and before the timing Tx at which the crank angle rotates 36 degrees from the intake stroke end timing TIe (the time when the in-cylinder pressure P1 becomes the solenoid valve downstream pressure P3). When the solenoid valve 6 receives the valve open command, it opens, and the solenoid valve downstream pressure P3 increases. When the pressure difference between the solenoid valve downstream pressure P3 and the in-cylinder pressure P1 becomes greater than 0, fuel gas F is supplied to the combustion chamber 3. When the solenoid valve 6 is closed during the intake stroke or compression stroke and the pressure difference between the solenoid valve downstream pressure P3 and the in-cylinder pressure P1 becomes equal to or less than 0, the check valve 8 blocks the supply of fuel gas F to the combustion chamber 3. The combustion stroke is initiated after the supply of fuel gas F to the combustion chamber 3 is blocked.

[0024] In the first embodiment, as shown in FIG. 2, the control device 10 transmits a valve open command to the solenoid valve 6 at a valve open timing T1 that is later than the end timing TIe of the intake stroke. In other words, the valve open timing T1 is within the period of the compression stroke that follows the intake stroke. The control device 10 transmits a valve close command to the solenoid valve 6 within the period of this compression stroke. The solenoid valve 6 closes upon receiving the valve close command. The valve open timing T1 is located in the first half of the compression stroke, and the valve close timing T2 at which the solenoid valve 6 is closed is located in the second half of the compression stroke. The length of the period from the valve open timing T1 to the valve close timing T2 is not particularly limited.

[0025] 1, the gas engine 1 further includes a compressor 14 for increasing the pressure of the fuel gas F supplied from the fuel supply source 12. The compressor 14 is provided upstream of the solenoid valve 6 in the fuel supply line 4.

[0026] Incidentally, the gas engine 1 according to the present disclosure is not particularly limited in the method of igniting the fuel gas F in the combustion chamber 3. In some embodiments, the gas engine 1 includes an ignition device (spark plug) provided in the combustion chamber 3. In some embodiments, the gas engine 1 includes an ignition device provided in an auxiliary chamber formed separately from the combustion chamber 3 and to which the fuel gas F is supplied. In this gas engine 1, the fuel gas F in the combustion chamber 3 is ignited by a flame generated when the ignition device combusts the fuel gas F in the auxiliary chamber.

[0027] (Actions and Effects) The operation and effect of the gas engine 1 according to the first embodiment will be described. According to the first embodiment, the gas engine 1 employs the solenoid valve 6 and the check valve 8. Therefore, by increasing the solenoid valve upstream pressure P2 and opening the solenoid valve 6, a large amount of fuel gas F can be supplied to the combustion chamber 3. Furthermore, since the solenoid valve 6 and the check valve 8 are simply provided in the fuel supply line 4, an increase in manufacturing costs for the gas engine 1 can be suppressed. In particular, the manufacturing costs for the gas engine 1 according to the present disclosure can be reduced compared to a gas engine having an injector provided in the cylinder head 33. Furthermore, since the check valve 8 does not open when the in-cylinder pressure P1 is greater than the solenoid valve downstream pressure P3, damage to the solenoid valve 6 due to gas generated by combustion of the fuel gas F flowing into the fuel supply line 4 can be suppressed.

[0028] In conventional gas engines, when fuel gas F containing hydrogen is used, the injection pressure of the fuel gas F is low, and therefore a large injector is required to supply a large amount of fuel gas F to the combustion chamber 3. In contrast, the gas engine 1 according to the present disclosure uses the solenoid valve 6 and the check valve 8 to inject fuel into the combustion chamber 3 by utilizing the pressure difference between the in-cylinder pressure P1 and the solenoid valve downstream pressure P3, which is advantageous in that the size of the gas engine 1 can be made compact.

[0029] According to the first embodiment, the gas engine 1 includes the compressor 14, and therefore the solenoid valve upstream pressure P2 can be adjusted as desired. That is, the amount of fuel gas F supplied to the combustion chamber 3 can be adjusted as desired.

[0030] If fuel gas F is supplied during the intake stroke, there is a possibility that the fuel gas F will flow into the intake passage 5. Hydrogen has a faster combustion speed than other gases such as methane and propane. For this reason, there is a risk of backfire. According to the first embodiment, the solenoid valve 6 is opened during the compression stroke, and the fuel gas F is supplied to the combustion chamber 3. During the compression stroke, the intake valve 36 closes the intake port 35, so that the fuel gas F is prevented from flowing into the intake line 2, and the occurrence of backfire can be suppressed.

[0031] Note that the present disclosure does not limit the valve opening timing T1 and the valve closing timing T2 to the timings described in the first embodiment. Figures 3A and 3B are diagrams for explaining the opening and closing periods of the solenoid valve 6 according to some embodiments. In the embodiment illustrated in Figure 3A, the valve opening timing T1 is the start timing TIs of the intake stroke, and the valve closing timing T2 is the end timing TIe of the intake stroke. In the embodiment illustrated in Figure 3B, the valve opening timing T1 is after the crank angle 30 degrees before the end timing TIe of the intake stroke, and the valve closing timing T2 is within the compression stroke. In other words, the period during which fuel gas F is supplied spans both the intake stroke and the compression stroke.

[0032] The inventors have found that if the valve closing timing T2 is included in the compression stroke, there is a risk that the check valve 8 will open during the following exhaust stroke. Fig. 4 is a graph showing the relationship between the crank angle and pressure of the gas engine 1 according to the first embodiment. In Fig. 4, the in-cylinder pressure P1 is shown by a solid line, the solenoid valve upstream pressure P2 is shown by a dotted line, and the solenoid valve downstream pressure P3 is shown by a dashed line.

[0033] As shown in Figure 4, the check valve 8 closes when the solenoid valve 6 is closed and the solenoid valve downstream pressure P3 becomes lower than the in-cylinder pressure P1. Then, because the downstream portion 13 of the fuel flow path 7 is sealed, the solenoid valve downstream pressure P3 is maintained at a certain level. When the engine proceeds to the exhaust stroke following the compression stroke, the in-cylinder pressure P1 decreases. Therefore, at timing Ty, the solenoid valve downstream pressure P3 becomes higher than the in-cylinder pressure P1, which may cause fuel gas F to flow into the combustion chamber 3 during the exhaust stroke (leading to leakage of fuel gas F). To address this concern, the present inventors propose a gas engine 1 according to a second embodiment.

[0034] Second Embodiment A gas engine 1 according to a second embodiment of the present disclosure will now be described. The gas engine 1 according to the second embodiment differs from the first embodiment in that it further includes a leak line 20. In the second embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and detailed descriptions thereof will be omitted.

[0035] (composition) 5 is a diagram schematically showing the configuration of a gas engine 1 according to a second embodiment. As shown in FIG. 5, the gas engine 1 further includes a leak line 20 and a leak electromagnetic valve 22.

[0036] The leak line 20 has a leak flow path 21 formed therein. One end of the leak line 20 is connected to a portion of the fuel supply line 4 between the solenoid valve 6 and the check valve 8, and opens to a downstream portion 13 of the fuel flow path 7. The other end of the leak line 20 opens to an open space 24. In the embodiment illustrated in FIG. 5 , the open space 24 is a portion of the fuel flow path 7 between the fuel supply source 12 and the compressor 14 (hereinafter referred to as an introduction portion 15).

[0037] The leak solenoid valve 22 is provided in the leak line 20. This leak solenoid valve 22 opens and closes the leak flow path 21. Specifically, the leak solenoid valve 22 is electrically connected to the control device 10, and opens and closes the leak flow path 21 in accordance with instructions transmitted from the control device 10.

[0038] An example of control of the leak solenoid valve 22 by the control device 10 will be described. FIG. 6 is a diagram for explaining the opening and closing periods of the leak solenoid valve 22 according to the second embodiment. As described in the first embodiment, the valve closing timing T2 at which the solenoid valve 6 closes is within the compression stroke. The control device 10 transmits a valve open instruction to the leak solenoid valve 22 at a leak valve open timing T3 between the closing of the solenoid valve 6 during the compression stroke and the exhaust stroke following the compression stroke. The leak solenoid valve 22 opens upon receiving the valve open instruction. In the embodiment illustrated in FIG. 6, the leak valve open timing T3 is simultaneous with or immediately after the valve closing timing T2. The control device 10 then transmits a valve close instruction to the leak solenoid valve 22 before the next supply of fuel gas F to the combustion chamber 3 (the next valve open timing T1′) begins. The leak solenoid valve 22 closes upon receiving the valve close instruction. For this reason, the leak solenoid valve 22 is configured to close when the solenoid valve 6 is open. In the embodiment illustrated in Fig. 6, the leak solenoid valve 22 closes at a leak valve closing timing T4 within the period of the next compression stroke (shown by the dotted line in Fig. 6). In some embodiments, the leak valve closing timing T4 is within the period of the compression stroke, the period of the combustion stroke, or the period of the exhaust stroke.

[0039] (Actions and Effects) The operation and effect of the gas engine 1 according to the second embodiment will now be described. FIG. 7 is a graph showing the relationship between crank angle and pressure in the gas engine 1 according to the second embodiment. As described with reference to FIG. 4, if the valve closing timing T2 is included in the compression stroke, there is a risk that the check valve 8 will open during the exhaust stroke. In contrast, according to the second embodiment, the fuel gas F remaining in the downstream portion 13 of the fuel flow path 7 is released into the open space 24 via the leak line 20. Therefore, as shown in FIG. 7, the pressure P3 downstream of the solenoid valve is prevented from becoming greater than the in-cylinder pressure P1 during the exhaust stroke, and the inflow of the fuel gas F into the combustion chamber 3 during the exhaust stroke can be suppressed.

[0040] According to the second embodiment, the leak solenoid valve 22 is provided in the leak line 20, so it is possible to arbitrarily adjust the timing for releasing the fuel gas F remaining in the downstream portion 13 of the fuel flow path 7 into the open space 24. Furthermore, according to the second embodiment, the leak solenoid valve 22 is closed when the solenoid valve 6 is open, so it is possible to prevent a portion of the fuel gas F from being released into the open space 24 when the fuel gas F is supplied to the combustion chamber 3.

[0041] It should be noted that the present disclosure is not limited to providing the leak solenoid valve 22 in the leak line 20. In some embodiments, the gas engine 1 includes an intake line 2, a fuel supply line 4, a solenoid valve 6, a check valve 8, and a leak line 20, and the leak line 20 is not provided with the leak solenoid valve 22.

[0042] According to the second embodiment, the introduction portion 15 of the fuel flow path 7 is used as the open space 24, which suppresses the release of the fuel gas F to the outside of the gas engine 1. As a result, it is possible to suppress a decrease in the thermal efficiency of the gas engine 1.

[0043] It should be noted that the present disclosure is not limited to application of the open space 24 to the inlet portion 15 of the fuel flow path 7. 8A and 8B are diagrams each schematically illustrating the configuration of a gas engine 1 according to some embodiments.

[0044] 8A, the open space 24 is the atmosphere. That is, the other end of the leak line 20 is open to the atmosphere. With this configuration, the leak line 20 is easy to manufacture, and therefore, an increase in the manufacturing cost of the gas engine 1 due to the installation of the leak line 20 can be suppressed.

[0045] In the embodiment illustrated in FIG. 8B, the open space 24 is the intake flow path 5. That is, the other end of the leak line 20 is connected to the intake line 2. With this configuration, the release of fuel gas F to the outside of the gas engine 1 is suppressed, thereby suppressing a decrease in the thermal efficiency of the gas engine 1. The open space 24 may also be the intake port 35.

[0046] The contents described in each of the above embodiments can be understood, for example, as follows.

[0047] [1] The gas engine (1) according to the present disclosure is A gas engine that burns a fuel gas (F) containing hydrogen in a combustion chamber (3), an intake line (2) having an intake passage (5) formed therein, the intake line including an intake port (35) through which the intake passage opens into the combustion chamber; a fuel supply line (4) provided separately from the intake line, the fuel supply line having a fuel flow path (7) formed therein through which the fuel gas flows toward the combustion chamber, the outlet of the fuel flow path opening into the combustion chamber; an electromagnetic valve (6) provided in the fuel supply line for opening and closing the fuel flow path; The fuel supply line includes a check valve (8) that is provided closer to the combustion chamber than the solenoid valve and opens and closes the fuel flow path according to a pressure difference between the fuel flow path and the combustion chamber.

[0048] According to the configuration described in [1] above, since the solenoid valve and check valve are used, a large amount of fuel gas can be supplied to the combustion chamber by increasing the pressure in the portion of the fuel flow path upstream of the solenoid valve and opening the solenoid valve. Furthermore, since only the solenoid valve and check valve are provided in the fuel supply line, increases in manufacturing costs can be suppressed. The gas engine according to the present disclosure can be manufactured at lower costs than, for example, a gas engine equipped with an injector.

[0049] [2] In some embodiments, in the configuration described in [1] above, The fuel supply system further includes a leak line (20) having a leak flow path (21) formed therein, one end of the leak line (20) connected to a portion (13) of the fuel supply line between the solenoid valve and the check valve, and the other end of the leak line (20) open to an open space (24).

[0050] When the solenoid valve closes during the compression stroke, there is a risk that fuel gas with a pressure high enough to open the check valve during the exhaust stroke may remain in the fuel supply line between the solenoid valve and the check valve. In this case, there is a risk that fuel gas may flow into the combustion chamber (leading to a fuel gas leak) during the exhaust stroke. In response to this, the configuration described in [2] above allows the fuel gas remaining in the fuel supply line between the solenoid valve and the check valve to be released into an open space via a leak line, thereby preventing fuel gas from flowing into the combustion chamber during the exhaust stroke.

[0051] [3] In some embodiments, in the configuration described in [2] above, a leak solenoid valve (22) provided in the leak line for opening and closing the leak flow path; The leak solenoid valve is configured to close when the solenoid valve is open.

[0052] According to the configuration described in [3] above, the timing for releasing the fuel gas remaining in the fuel supply line between the solenoid valve and the check valve into the open space can be adjusted as desired. Furthermore, when the fuel gas is supplied to the combustion chamber, it is possible to prevent a portion of the fuel gas from being released into the open space.

[0053] [4] In some embodiments, in the configuration described in [3] above, The solenoid valve is configured to close during a compression stroke, The leak solenoid valve is configured to open during the period from when the solenoid valve is closed during the compression stroke until the next exhaust stroke after the compression stroke.

[0054] According to the configuration described in [4] above, the fuel gas remaining in the portion of the fuel supply line between the solenoid valve and the check valve can be released into the open space while suppressing any adverse effects on the operation of the gas engine.

[0055] [5] In some embodiments, in the configuration described in [2] above, The open space is the atmosphere.

[0056] According to the configuration described in [5] above, the leak line is easy to manufacture, so that an increase in manufacturing costs due to the installation of the leak line can be suppressed.

[0057] [6] In some embodiments, in the configuration described in [2] above, The open space is the intake flow path.

[0058] According to the configuration described in [6] above, the release of fuel gas to the outside of the gas engine is suppressed, so that the decrease in thermal efficiency can be suppressed.

[0059] [7] In some embodiments, in the configuration described in [2] above, The open space is a portion of the fuel flow path that is upstream of the solenoid valve in the fuel supply line.

[0060] According to the configuration described in [7] above, the release of fuel gas to the outside of the gas engine is suppressed, so that the decrease in thermal efficiency can be suppressed.

[0061] [8] In some embodiments, in the configuration described in any one of [1] to [7] above, The fuel supply system further includes a compressor (14) that is provided upstream of the solenoid valve in the fuel supply line and that increases the pressure of the fuel gas.

[0062] According to the configuration described in [8] above, the pressure in the fuel flow path on the upstream side of the solenoid valve can be adjusted as desired.

[0063] [9] In some embodiments, in the configuration described in any one of [1] to [7] above, The solenoid valve is configured to open after the timing (Tx) of the crank angle 30 degrees before the end timing (TIe) of the intake stroke.

[0064] According to the configuration described in [9] above, it is possible to prevent fuel gas from flowing into the intake line during the intake stroke, thereby suppressing the occurrence of flashback.

[0065]

[10] In some embodiments, in the configuration described in [9] above, The electromagnetic valve is configured to open after the end timing.

[0066] According to the configuration described in

[10] above, the occurrence of flashback can be further suppressed compared to the configuration described in [9] above. [Explanation of symbols]

[0067] 1 gas engine 2 intake lines 3 Combustion chamber 4 fuel supply lines 5 Intake passage 6. Solenoid valve 7 Fuel flow path 8. Check valve 10 Control device 11 Upstream portion of fuel flow path 12 Fuel supply source 13 Downstream portion of fuel flow path 14 Compressor 15 Fuel flow path introduction 20 Leak Line 21 Leak flow path 22 Leak solenoid valve 24 Open space 31 Cylinder liner 32 piston 33 Cylinder head 34 Top of piston 35 intake port 36 Intake valve 37 Exhaust port 38 Exhaust valve 39 fuel port C Cylinder liner central axis F Fuel gas P1 Cylinder pressure P2 Solenoid valve upstream pressure P3 Solenoid valve downstream pressure T1 valve opening timing T2 Valve closing timing T3 Leak valve opening timing T4 Leak valve closing timing TIe End timing TIs start timing

Claims

1. A gas engine that burns fuel gas containing hydrogen in a combustion chamber, an intake line having an intake passage formed therein, the intake line including an intake port where the intake passage opens into the combustion chamber; a fuel supply line provided separately from the intake line, the fuel supply line having a fuel flow path formed therein through which the fuel gas flows toward the combustion chamber, the outlet of the fuel flow path opening into the combustion chamber; an electromagnetic valve provided in the fuel supply line for opening and closing the fuel flow path; a check valve that is provided on the combustion chamber side of the fuel supply line relative to the solenoid valve and that opens and closes the fuel flow path based on a pressure difference between the fuel flow path and the combustion chamber. Gas engine.

2. a leak line having a leak passage formed therein, one end of the leak line being connected to a portion of the fuel supply line between the solenoid valve and the check valve and the other end being open to an open space; 2. The gas engine according to claim 1.

3. a leak solenoid valve provided in the leak line for opening and closing the leak flow path; The leak solenoid valve is configured to close when the solenoid valve is open.

3. The gas engine according to claim 2.

4. The solenoid valve is configured to close during a compression stroke, The leak solenoid valve is configured to open during a period from when the solenoid valve is closed during the compression stroke until the next exhaust stroke after the compression stroke.

4. The gas engine according to claim 3.

5. The open space is the atmosphere.

3. The gas engine according to claim 2.

6. The open space is the intake flow path.

3. The gas engine according to claim 2.

7. the open space is a portion of the fuel flow path upstream of the solenoid valve in the fuel supply line.

3. The gas engine according to claim 2.

8. a compressor provided upstream of the solenoid valve in the fuel supply line to pressurize the fuel gas; A gas engine according to any one of claims 1 to 7.

9. The solenoid valve is configured to open after the timing of the crank angle 30 degrees before the end timing of the intake stroke. A gas engine according to any one of claims 1 to 7.

10. The solenoid valve is configured to open after the end timing.

10. The gas engine according to claim 9.

Images