Purge device for gas engine and operating method for the same

Abstract

To provide a purge device that can be easily mounted to a gas engine.SOLUTION: A purge device for a gas engine includes: a fuel line connected to an engine inlet pipe located on the most upstream side of engine side fuel piping of a gas engine to supply gas fuel to the gas engine; a fuel shutoff valve provided in the fuel line; a purge line connected to a purge line connection part on the downstream side of the fuel shutoff valve in the fuel line to supply inert gas to the fuel line and the engine side fuel piping; and a vent line for discharging gas fuel from the fuel line and the engine side fuel piping, the vent line connected to a vent line connection part on the downstream side of the fuel shutoff valve in the fuel line.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a purge device for a gas engine and a method of operating the purge device. [Background technology]

[0002] For example, Patent Document 1 discloses a method of purging gas fuel from a fuel gas pipe by supplying an inert gas to the fuel gas pipe when the operation of a gas engine is stopped. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 61-229966 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technology described in Patent Document 1, a pipe (branch pipe) that supplies purge gas to discharge gas fuel from the fuel gas pipe is connected to the header pipe of the gas engine. Therefore, it is necessary to extend the branch pipe to the gas engine, but it is sometimes difficult to secure space around the gas engine to arrange the branch pipe, and it is therefore difficult to attach the branch pipe to the gas engine.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a gas engine purge device that can be easily attached to a gas engine, and a method for operating this purge device. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the purge device for a gas engine according to the present disclosure comprises a fuel line connected to an engine inlet pipe located at the most upstream side of the engine-side fuel piping of the gas engine and for supplying gas fuel to the gas engine, a fuel shut-off valve provided in the fuel line, a purge line connected to a purge line connection portion of the fuel line downstream of the fuel shut-off valve and for supplying an inert gas to the fuel line and the engine-side fuel piping, and a vent line for discharging the gas fuel from the fuel line and the engine-side fuel piping, the vent line being connected to a vent line connection portion of the fuel line downstream of the fuel shut-off valve. [Effects of the Invention]

[0007] The gas engine purge device of the present disclosure can be easily attached to the gas engine. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram schematically illustrating a configuration of a purge device according to a first embodiment. [Figure 2] FIG. 2 is a diagram for explaining the installation position of the mixing promotion device according to the first embodiment. [Figure 3] FIG. 2 is a diagram for explaining the installation position of the concentration measuring device according to the first embodiment. [Figure 4] FIG. 6 is a diagram schematically illustrating the configuration of a purge device according to a second embodiment. [Figure 5] 3 is a flowchart of a method for operating the purge device according to the first embodiment. [Figure 6A] FIG. 4 is a diagram showing a state of the purge device after an engine stop step according to the first embodiment is executed. [Figure 6B] FIG. 4 is a diagram showing a state of the purge device after an opening step according to the first embodiment has been performed. [Figure 6C] FIG. 4 is a diagram showing a state of the purge device after an inert gas supply step according to the first embodiment has been performed. [Figure 6D]FIG. 4 is a diagram showing the state of the purging device after the mixing step according to the first embodiment has been performed. [Figure 6E] FIG. 4 is a diagram showing a state of the purging device after a discharge step according to the first embodiment has been performed. [Figure 7] 10 is a flowchart of a method for operating a purge device according to a second embodiment. [Figure 8A] FIG. 10 is a diagram showing a state of the purge device after an engine stop step according to the second embodiment is executed. [Figure 8B] FIG. 10 is a diagram showing a state of the purge device after an opening step according to the second embodiment has been performed. [Figure 8C] FIG. 10 is a diagram showing the state of the purge device after a second opening step according to the second embodiment has been performed. [Figure 8D] FIG. 10 is a diagram showing a state of the purge device after an inert gas supply step according to the second embodiment has been performed. [Figure 8E] FIG. 10 is a diagram showing the state of the purging device after the mixing step according to the second embodiment has been performed. [Figure 8F] FIG. 10 is a diagram showing a state of the purging device after a discharge step according to the second embodiment has been performed. DETAILED DESCRIPTION OF THE INVENTION

[0009] A purge device for a gas engine and an operating method of the purge device 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, does not limit the present disclosure, and can be modified as desired within the scope of the technical concept of the present disclosure.

[0010] FIG. 1 is a diagram schematically showing the configuration of a purging device 1 according to a first embodiment. As shown in FIG. 1, the purging device 1 is attached to a gas engine 100. An example of the configuration of the gas engine 100 will be described. As shown in FIG. 1, the gas engine 100 includes a combustion chamber 101, an engine-side fuel pipe 104 communicating with the combustion chamber 101, a fuel injection valve 106 provided in the engine-side fuel pipe 104, and a control device 150.

[0011] The combustion chamber 101 is defined within the cylinder 110 between a piston 112 and a cylinder head 114. In the embodiment illustrated in Figure 1, the gas engine 100 includes multiple combustion chambers 101. In some embodiments, the gas engine 100 includes one combustion chamber 101.

[0012] In the embodiment illustrated in FIG. 1, the engine-side fuel piping 104 includes, in order from the upstream side in the direction in which gas fuel F (described later) flows through the engine-side fuel piping 104, an engine inlet pipe 116, a header pipe 118, and multiple (six) branch pipes 120.

[0013] The engine inlet pipe 116 is located at the most upstream of the engine-side fuel pipe 104 of the gas engine 100. The engine inlet pipe 116 is formed with an inlet 122 for allowing gas fuel F to flow into the engine-side fuel pipe 104 from outside the gas engine 100. In the present disclosure, the engine-side fuel pipe 104 has one end connected to a flexible pipe 126 (described below) and the other end connected to the cylinder head 114, and the other end is formed with an outlet 124 that opens into the combustion chamber 101. Note that in some embodiments, the engine-side fuel pipe 104 is connected to the combustion chamber 101 via an intake line for allowing air to flow into the combustion chamber 101. In this case, the engine-side fuel pipe 104 is connected to the intake line.

[0014] The header pipe 118 is connected to the downstream end of the engine inlet pipe 116. The multiple branch pipes 120 are connected to the header pipe 118 at different connection positions. An outlet 124 of the engine-side fuel pipe 104 is formed at the downstream end of each of the multiple branch pipes 120. A fuel injection valve 106 is provided in each of the multiple branch pipes 120. The fuel injection valve 106 is an electromagnetic valve electrically connected to the control device 150 (p1), and is opened or closed at a desired opening degree in accordance with instructions sent from the control device 150.

[0015] The control device 150 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 150 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 150. In some embodiments, the control device 150 is a cloud server provided in a cloud environment.

[0016] First Embodiment (composition) The configuration of a purging device 1 according to the first embodiment will be described. As shown in Fig. 1, the purging device 1 includes a fuel line 2, a fuel shutoff valve 4, a purge line 6, and a vent line 8. In the first embodiment, the purging device 1 further includes a check valve 60, a mixing promotion device 70, a pressure sensor 80, and a concentration measurement device 90.

[0017] The fuel line 2 connects a fuel supply source 50 (fuel tank) in which gas fuel F is stored to the engine inlet pipe 116. The fuel line 2 is configured to allow the gas fuel F to flow from the fuel supply source 50 toward the engine inlet pipe 116, and supplies the gas fuel F to the gas engine 100. The gas fuel F is not particularly limited, and may be, for example, hydrogen gas or natural gas. In some embodiments, the gas fuel F is lighter than air. In some embodiments, the gas fuel F is lighter than inert gas Gn. The fuel supply source 50 stores the gas fuel F in a gaseous state. Note that the fuel supply source 50 may store liquefied gas fuel F (liquid fuel). In this case, a vaporizer for vaporizing the liquid fuel is provided.

[0018] In the first embodiment, the fuel line 2 includes a flexible pipe 126 disposed between the engine inlet pipe 116 and a vent line connection 12 (described below). The flexible pipe 126 is connected to the engine inlet pipe 116. That is, the flexible pipe 126 forms the outlet of the fuel line 2. The flexible pipe 126 has a corrugated outer shape and is made of a thin-walled metal such as stainless steel. In some embodiments, the flexible pipe 126 is located between the inlet and outlet of the fuel line 2.

[0019] The fuel cutoff valve 4 is provided in the fuel line 2. In the first embodiment, the fuel cutoff valve 4 is a solenoid valve electrically connected to the control device 150 (p2), and is opened or closed according to instructions transmitted from the control device 150. Note that the present disclosure is not limited to the control device 150 of the gas engine 100 controlling the opening and closing of the fuel cutoff valve 4. In some embodiments, the purge device 1 further includes a purge-side control device electrically connected to the fuel cutoff valve 4 and capable of controlling the opening and closing of the fuel cutoff valve 4.

[0020] The purge line 6 supplies the inert gas Gn to the fuel line 2 and the engine-side fuel piping 104. The inert gas Gn is a gas that does not undergo a combustion reaction, such as nitrogen gas. The purge line 6 connects the fuel line 2 to an inert gas supply source 52 in which the inert gas Gn is stored. The purge line 6 is configured to allow the inert gas Gn to flow from the inert gas supply source 52 toward the fuel line 2. The purge line 6 is connected to the gas engine 100 side of the fuel shutoff valve 4 (downstream of the fuel line 2). In the present disclosure, the portion of the fuel line 2 to which the purge line 6 is connected is referred to as a purge line connection portion 10.

[0021] In the first embodiment, the purge device 1 further includes a purge valve 20 provided in the purge line 6, and a purge check valve 21 provided on the fuel line 2 side (downstream side) of the purge valve 20 in the purge line 6. The purge valve 20 is a solenoid valve electrically connected to the control device 150 (p3), and is opened or closed in accordance with instructions transmitted from the control device 150. The purge check valve 21 prevents gas (gas fuel F or inert gas Gn) from flowing through the purge line 6 to the inert gas supply source 52.

[0022] The vent line 8 is provided to discharge the gaseous fuel F from the fuel line 2 and the engine-side fuel piping 104. One end 8a of the vent line 8 is connected to a vent line connection portion 12 downstream of the fuel cutoff valve 4 in the fuel line 2, and the other end 8b is open to the atmosphere. In the first embodiment, the vent line 8 is disposed above the fuel line 2.

[0023] In the first embodiment, the purging device 1 further includes a vent valve 22 provided in the vent line 8. The vent valve 22 is a solenoid valve electrically connected to the control device 150 (p4), and is opened or closed in accordance with an instruction transmitted from the control device 150.

[0024] The check valve 60 is provided closer to the other end 8b of the vent line 8 (downstream) than the vent valve 22. The check valve 60 prevents gas (atmospheric air) from flowing through the vent line 8 to the fuel line 2.

[0025] The mixing promotion device 70 is provided on the gas engine 100 side of the fuel line 2 (downstream side of the fuel line 2) relative to the fuel shutoff valve 4. The mixing promotion device 70 is, for example, a swirl flow generating device that applies a swirling force to the inert gas Gn flowing through the fuel line 2. The application of the swirl force to the inert gas Gn promotes mixing with the gas fuel F, thereby homogenizing the concentration of the gas fuel F in the portion of the fuel line 2 downstream of the fuel shutoff valve 4 and the portion of the engine-side fuel piping 104 upstream of the fuel injection valve 106 (hereinafter, this portion will be referred to as the first purge target portion X1). Note that the mixing promotion device 70 is not limited to a swirl flow generating device. For example, the mixing promotion device 70 may include a plurality of resistance plates against which the inert gas Gn collides, thereby forming turbulence in the fuel line 2.

[0026] The installation position of the mixing promotion device 70 will be described. FIG. 2 is a diagram for explaining the installation position of the mixing promotion device 70 according to the first embodiment. The fuel injector 106A (106) shown in FIG. 2 is the fuel injector 106 closest to the inlet 122 of the engine-side fuel pipe 104 among the multiple fuel injectors 106. As shown in FIG. 2, the purge line connection portion 10 divides the region from the fuel shutoff valve 4 to the fuel injector 106A into a first region R1 and a second region R2 that is larger than the first region R1. The mixing promotion device 70 is disposed on the purge line connection portion 10 side of the second region R2. In one embodiment, the mixing promotion device 70 is disposed immediately downstream of the purge line connection portion 10.

[0027] The pressure sensor 80 is provided on the gas engine 100 side of the fuel line 2 relative to the fuel shutoff valve 4 (downstream side of the fuel line 2) and measures air pressure. In the first embodiment, the pressure sensor 80 is arranged between the purge line connection part 10 and the vent line connection part 12, and downstream of the mixing promotion device 70. The pressure sensor 80 is electrically connected to the control device 150 and transmits measured values to the control device 150. Although not shown, the purge device 1 further includes a filter that is provided in the fuel line 2 and that prevents foreign matter from entering the gas engine 100. The filter is provided in the fuel line 2 so as to be located, for example, between the mixing promotion device 70 and the pressure sensor 80.

[0028] The concentration measuring device 90 is provided upstream of the fuel injection valve 106 in the engine-side fuel pipe 104, and measures the concentration of a component (e.g., hydrogen) contained in the gas fuel F. In the first embodiment, the concentration measuring device 90 is provided in the header pipe 118, and measures the concentration of the gas fuel F in the header pipe 118. The concentration measuring device 90 is electrically connected to the control device 150, and transmits the measurement value to the control device 150.

[0029] The installation position of the concentration measuring device 90 will be described. FIG. 3 is a diagram for explaining the installation position of the concentration measuring device 90 according to the first embodiment. The fuel injector 106B (106) shown in FIG. 3 is the fuel injector 106 farthest from the inlet 122 of the engine-side fuel pipe 104 among the multiple fuel injectors 106. In FIG. 3, the flow path from the inlet 122 of the engine-side fuel pipe 104 to the fuel injector 106B is shown shaped like a straight line. As shown in FIG. 3, the inlet 122 of the engine-side fuel pipe 104 is defined as 0% of the length of the flow path from the inlet 122 of the engine-side fuel pipe 104 to the fuel injector 106B, and the length increases toward the fuel injector 106B, with the installation position of the fuel injector 106B being defined as 100% of the length of the flow path. In this case, the installation position of the concentration measuring device 90 falls within a range of 80% or more and less than 100% of the length of the flow path.

[0030] (Actions and Effects) The following describes the operation and effect of the purging device 1 according to the first embodiment. Connecting the vent line 8 to the header pipe 118 of the gas engine 100 may facilitate the discharge of the gas fuel F from the first purging target portion X1. However, various components are arranged around the gas engine 100, making it difficult to secure space for connecting the vent line 8 to the header pipe 118, and thus making it difficult to attach the purging device 1 to the gas engine 100. In contrast, according to the first embodiment, the vent line 8 is connected to the fuel line 2 and is therefore arranged at a distance from the gas engine 100. This reduces interference between the vent line 8 and components that constitute the outer periphery of the gas engine 100 or components arranged around the gas engine. This makes it easier to attach the purging device 1 to the gas engine 100.

[0031] According to the first embodiment, the purge device 1 includes a mixing promotion device 70, which promotes mixing of the inert gas Gn and the gas fuel F when the inert gas Gn is supplied to the fuel line 2, thereby accelerating the discharge of the gas fuel F from the first purge target portion X1.

[0032] According to the first embodiment, the mixing promotion device 70 is disposed on the purge line connection part 10 side of the second region R2, and therefore the inert gas Gn flowing in from the purge line connection part 10 flows through the mixing promotion device 70 and then flows toward the side of the second region R2 opposite to the purge line connection part 10 side. This ensures a large space for promoting the mixing of the inert gas Gn and the gas fuel F, and therefore the mixing of the inert gas Gn and the gas fuel F can be efficiently carried out.

[0033] According to the first embodiment, the purge line 6 is connected to the purge line connection portion 10 of the fuel line 2, and therefore, like the vent line 8, the purge line 6 is also arranged at a distance from the gas engine 100, thereby suppressing interference with members that form the outer periphery of the gas engine 100 or members arranged around the gas engine 100. This makes it even easier to attach the purge device 1 to the gas engine 100.

[0034] According to the first embodiment, since the fuel line 2 includes the flexible pipe 126, transmission of vibrations of the gas engine 100 to the vent line 8 is suppressed, and damage to the vent line 8 can be suppressed.

[0035] According to the first embodiment, the purge device 1 includes the check valve 60, so that the air can be prevented from flowing into the fuel line 2 through the vent line 8.

[0036] According to the first embodiment, the vent line 8 is located above the fuel line 2. Therefore, for example, when the gas fuel F is a lightweight gas fuel F such as hydrogen gas, the gas fuel F can easily flow from the fuel line 2 into the vent line 8. Although not shown, in some embodiments, the vent line 8 includes an upward extension portion that extends upward toward the other end 8b. With this configuration, the lightweight gas fuel F such as hydrogen gas can be smoothly guided to the outside of the purge device 1.

[0037] According to the first embodiment, the purge device 1 includes the pressure sensor 80, and therefore, based on the measurement value of the pressure sensor 80, it is possible to detect whether or not an abnormality has occurred in the fuel injection valve 106, the fuel cutoff valve 4, etc., and to confirm whether or not the gas fuel F is being discharged from the first purge target portion X1 via the vent line 8.

[0038] When the vent line connection part 12 is located downstream of the fuel cutoff valve 4 in the fuel line 2 and the purge line connection part 10 is located downstream of the fuel cutoff valve 4 in the fuel line 2, the gaseous fuel F in the engine side fuel piping 104 is more difficult to discharge than the gaseous fuel F in the fuel line 2. According to the first embodiment, the purge device 1 includes the concentration measuring device 90 (provided in the header pipe 118), and therefore it is possible to confirm that the gaseous fuel F is being discharged from the engine side fuel piping 104 based on the measurement value of the concentration measuring device 90.

[0039] Second Embodiment A purging device 1 according to a second embodiment of the present disclosure will now be described. The purging device 1 according to the second embodiment differs from the first embodiment in that it further includes a second fuel shutoff valve 24, a second purge line 26, and a second vent line 28. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0040] Fig. 4 is a diagram schematically illustrating the configuration of a purging device 1 according to a second embodiment. As shown in Fig. 4, the purging device 1 further includes a second fuel shutoff valve 24, a second purge line 26, a second vent line 28, a second check valve 30, and a second pressure sensor 32.

[0041] The second fuel cutoff valve 24 is provided on the opposite side (upstream side) of the fuel line 2 from the gas engine 100 side relative to the fuel cutoff valve 4. In the second embodiment, the second fuel cutoff valve 24 is an electromagnetic valve electrically connected to the control device 150 (p5), and is opened or closed in accordance with instructions transmitted from the control device 150.

[0042] The second purge line 26 supplies the inert gas Gn to the fuel line 2. The second purge line 26 branches off from the purge line 6 upstream of the purge valve 20 and is connected to a portion of the fuel line 2 between the fuel shutoff valve 4 and the second fuel shutoff valve 24 (hereinafter, this portion will be referred to as the second purge target portion X2). The second purge line 26 is configured to allow the inert gas Gn to flow toward the fuel line 2. In the present disclosure, the portion of the fuel line 2 to which the second purge line 26 is connected will be referred to as the second purge line connection portion 27.

[0043] In the second embodiment, the purge device 1 further includes a second purge valve 34 provided in the second purge line 26, and a second purge check valve 35 provided on the fuel line 2 side (downstream side) of the second purge valve 34 on the second purge line 26. The second purge valve 34 is a solenoid valve electrically connected to the control device 150 (p6), and is opened or closed in accordance with instructions transmitted from the control device 150. The second purge check valve 35 prevents gas (gas fuel F or inert gas Gn) from flowing through the purge line 6 to the inert gas supply source 52.

[0044] The second vent line 28 is provided to discharge the gaseous fuel F from the fuel line 2. One end of the second vent line 28 is connected to the second purged portion X2, and the other end is connected to the other end 8b of the vent line 8 (downstream side) of the check valve 60. In the second embodiment, the second vent line 28 is disposed above the fuel line 2.

[0045] In the second embodiment, the purging device 1 further includes a second vent valve 36 provided in the second vent line 28. The second vent valve 36 is an electromagnetic valve electrically connected to the control device 150 (p7), and is opened or closed in accordance with an instruction transmitted from the control device 150.

[0046] The second check valve 30 is provided on the vent line 8 side of the second vent line 28 relative to the second vent valve 36. The second check valve 30 prevents gas (atmospheric air) from flowing through the second vent line 28 to the fuel line 2.

[0047] The second pressure sensor 32 is provided in the second purge target portion X2 and measures the air pressure. In the second embodiment, the second pressure sensor 32 is disposed between the second purge line connection portion 27 and the second vent line connection portion 29. The second pressure sensor 32 is electrically connected to the control device 150 and transmits the measured value to the control device 150.

[0048] (Actions and Effects) The operation and effect of the purging device 1 according to the second embodiment will be described. According to the second embodiment, the purging device 1 includes the second fuel shutoff valve 24, the second purge line 26, and the second vent line 28, so that the gaseous fuel F contained in the second purging target portion X2 can be discharged. According to the second embodiment, the gaseous fuel F contained in the first purging target portion X1 and the gaseous fuel F contained in the second purging target portion X2 are discharged in parallel, so that the completion of purging can be accelerated.

[0049] According to the second embodiment, the purge device 1 includes the second check valve 30, so that the air can be prevented from flowing into the fuel line 2 via the second vent line .

[0050] According to the second embodiment, the second vent line 28 is located above the fuel line 2, which makes it easier for a light gas fuel F, such as hydrogen gas, to flow from the fuel line 2 into the second vent line 28. Although not shown, in some embodiments, the second vent line 28 includes a second upward extension portion that extends upward toward the other end opposite to the one end connected to the fuel line 2. With this configuration, the light gas fuel F, such as hydrogen gas, can be smoothly guided.

[0051] According to the second embodiment, the purge device 1 includes the second pressure sensor 32, and therefore, based on the measurement value of the second pressure sensor 32, it is possible to detect whether or not an abnormality has occurred in the fuel shutoff valve 4, the second fuel shutoff valve 24, etc., and to confirm whether or not gas fuel F is being discharged from the second purge target portion X2 via the second vent line 28.

[0052] <Operation method of the purging device> For each of the purging device 1 according to the first embodiment and the purging device 1 according to the second embodiment, a method for discharging the gas fuel F from the fuel line 2 and the engine-side fuel piping 104 when the operation of the gas engine 100 is stopped will be described. Note that while the gas engine 100 is operating, the fuel shutoff valve 4 and the second fuel shutoff valve 24 are open, and the purge valve 20, the vent valve 22, the second purge valve 34, and the second vent valve 36 are closed. The fuel injection valve 106 is open or closed depending on the rotation speed and stroke of the gas engine 100.

[0053] (First embodiment) Fig. 5 is a flowchart of the method for operating the purge device 1 according to the first embodiment. As shown in Fig. 5, the method for operating the purge device 1 according to the first embodiment includes an engine stopping step S1, an opening step S2, an inert gas supplying step S3, a mixing step S4, a determining step S5, a discharging step S6, and a purge completion determining step S7.

[0054] Fig. 6A is a diagram showing the state of the purging device 1 after the engine stopping step S1 has been executed. Fig. 6B is a diagram showing the state of the purging device 1 after the opening step S2 has been executed. Fig. 6C is a diagram showing the state of the purging device 1 after the inert gas supplying step S3 has been executed. Fig. 6D is a diagram showing the state of the purging device 1 after the mixing step S4 has been executed. Fig. 6E is a diagram showing the state of the purging device 1 after the discharge step S6 has been executed. In Figs. 6A to 6E, the symbols of the fuel shutoff valve 4, the purge valve 20, the vent valve 22, and the fuel injection valve 106 are each painted white when the valve is open, and painted black when the valve is closed.

[0055] In the engine stop step S1, the fuel cutoff valve 4 and the fuel injection valve 106 are closed. In the first embodiment, when the operation of the gas engine 100 is stopped, the control device 150 transmits a valve close command to each of the fuel cutoff valve 4 and the fuel injection valve 106. The fuel cutoff valve 4 and the fuel injection valve 106 each receive the valve close command and close. Therefore, as shown in FIG. 6A, the fuel cutoff valve 4, the purge valve 20, the vent valve 22, and the fuel injection valve 106 are each in a closed state. Then, gas fuel F remains in the first purge target portion X1. In some embodiments, the control device 150 is capable of detecting the stop of operation of the gas engine 100, for example, by detecting that a power source (not shown) has been turned off.

[0056] In the opening step S2, after the engine stopping step S1, the vent valve 22 is opened. In the first embodiment, the control device 150 closes the fuel shutoff valve 4 and the fuel injection valve 106 by stopping the operation of the gas engine 100, and then transmits an open instruction to the vent valve 22. The vent valve 22 receives the open instruction and opens. Therefore, as shown in FIG. 6B, the fuel shutoff valve 4, the purge valve 20, and the fuel injection valve 106 are all closed, and the vent valve 22 is open. Then, a portion of the gas fuel F remaining in the first purge target portion X1 is discharged to the atmosphere via the vent line 8.

[0057] In the inert gas supply step S3, after the opening step S2, the vent valve 22 is closed and the purge valve 20 is opened. In the first embodiment, after the vent valve 22 is opened, a valve close instruction is sent to the vent valve 22 and a valve open instruction is sent to the purge valve 20. The vent valve 22 receives the valve close instruction and closes. The purge valve 20 receives the valve open instruction and opens. The purge valve 20 opens after the vent valve 22 closes. Therefore, as shown in FIG. 6C , the fuel shutoff valve 4, the vent valve 22, and the fuel injection valve 106 are all closed, and the purge valve 20 is open. Then, the inert gas Gn is supplied to the fuel line 2.

[0058] In the mixing step S4, after the inert gas supply step S3, the purge valve 20 is closed to mix the inert gas Gn and the gaseous fuel F. In the first embodiment, the control device 150 opens the purge valve 20 and then transmits a valve closing instruction to the purge valve 20. The purge valve 20 receives the valve closing instruction and closes. Therefore, as shown in FIG. 6D , the fuel shutoff valve 4, the purge valve 20, the vent valve 22, and the fuel injection valve 106 are all closed, and the first purge target portion X1 is sealed. Furthermore, the control device 150 maintains this sealed state of the first purge target portion X1 for a predetermined time. The predetermined time may be a constant value set in advance or may be a variable determined based on the measurement value of the pressure sensor 80. When the sealed state of the first purge target portion X1 is maintained for the predetermined time, the gaseous fuel F and the inert gas Gn contained in the first purge target portion X1 are sufficiently mixed.

[0059] In the determination step S5, between the mixing step S4 and the discharge step S6, it is determined whether an abnormality has occurred in at least one of the vent valve 22 and the fuel injection valve 106 based on the rate of decrease in the measurement value of the pressure sensor 80. In the first embodiment, the control device 150 acquires the measurement value of the pressure sensor 80 while the first purge target portion X1 is in a sealed state. The control device 150 then calculates the rate of decrease in the measurement value of the pressure sensor 80, and if the calculated rate of decrease is greater than a preset value, it determines that an abnormality has occurred in at least one of the vent valve 22 and the fuel injection valve 106. In other words, it is possible to detect leakage of gas fuel F into the combustion chamber 101 or the atmosphere. In some embodiments, the method further includes a notification step of notifying the occurrence of the abnormality if it is determined that an abnormality has occurred in the determination step S5. Note that if the rate of decrease in the measurement value of the pressure sensor 80 is greater than a preset value even though no abnormality has occurred in either the vent valve 22 or the fuel injection valve 106, it is possible to detect damage to the engine inlet pipe 116, the flexible pipe 126, or the like.

[0060] In the discharge step S6, after the mixing step S4, the vent valve 22 is opened. In the first embodiment, the control device 150 transmits an open instruction to the vent valve 22 after a predetermined time has elapsed since the first purge target portion X1 was sealed. The vent valve 22 receives the open instruction and opens. Therefore, as shown in FIG. 6E, the fuel shutoff valve 4, the purge valve 20, and the fuel injection valve 106 are all closed, and the vent valve 22 is open. Then, the gas fuel F contained in the first purge target portion X1 is discharged to the atmosphere together with the inert gas Gn via the vent line 8.

[0061] In the purge completion determination step S7, if the number of times that the discharge step S6 has been executed after the discharge step S6 exceeds a predetermined number of times (purge completion determination step S7: Yes), it is determined that the gas fuel F has been discharged, and if the number of times that the discharge step S6 has been executed is equal to or less than the predetermined number of times (purge completion determination step S7: No), the process returns to the inert gas supply step S3.

[0062] Although the purge completion determination step S7 determines whether the gaseous fuel F has been discharged based on the number of times the discharge step S6 has been performed, the present disclosure is not limited to this configuration. In some embodiments, the purge completion determination step S7 determines whether the gaseous fuel F has been discharged after the discharge step S6 based on the rate of decrease in the measurement value of the pressure sensor 80. Specifically, the control device 150 acquires the measurement value of the pressure sensor 80 until a certain period of time has elapsed since the vent valve 22 was opened. The control device 150 then calculates the rate of decrease in the measurement value of the pressure sensor 80, and if this calculated rate of decrease is smaller than a preset value (purge completion determination step S7: Yes), determines that the gaseous fuel F has been discharged from the first purge target portion X1. If the rate of decrease in the measurement value of the pressure sensor 80 is greater than the preset value (purge completion determination step S7: No), the control device 150 determines that the gaseous fuel F remains in the first purge target portion X1, and returns to the inert gas supply step S3. This method utilizes the fact that as the discharge of the gaseous fuel F progresses and the concentration of the inert gas Gn in the mixed gas (gaseous fuel F + inert gas Gn) increases, the density of the mixed gas increases and the discharge rate of the mixed gas decreases (i.e., the rate at which the measurement value of the pressure sensor 80 decreases decreases). In some embodiments, the purge completion determination step S7 determines whether the gaseous fuel F has been discharged based on the measurement value of the concentration measurement device 90 after the discharge step S6. In other words, the purge completion determination step S7 determines that the gaseous fuel F has been discharged if the measurement value of the concentration measurement device 90 becomes lower than a predetermined concentration after the discharge step S6.

[0063] According to the operating method of the purging device 1 of the first embodiment, when the gas engine 100 is stopped, the gaseous fuel F can be discharged from the first purge target portion X1. In the purging device 1 of the first embodiment, the vent line 8 is connected to the fuel line 2, so the gaseous fuel F is likely to remain in the engine-side fuel piping 104. According to the operating method of the purging device 1 of the first embodiment, the gaseous fuel F and the inert gas Gn are mixed in the mixing step S4, and then the gaseous fuel F is discharged together with the inert gas Gn in the discharge step S6. Therefore, the gaseous fuel F in the engine-side fuel piping 104 can be efficiently discharged.

[0064] According to the operating method of the purge device 1 in accordance with the first embodiment, the determination step S5 is executed, so it is possible to know whether or not an abnormality has occurred in at least one of the vent valve 22 and the fuel injection valve 106.

[0065] According to the method for operating the purging device 1 in accordance with the first embodiment, the purge completion determination step S7 is executed, so that the timing for ending the operation of the purging device 1 can be set.

[0066] (Second embodiment) An operation method of the purging device 1 according to the second embodiment will be described. Fig. 7 is a flowchart of the operation method of the purging device 1 according to the second embodiment. As shown in Fig. 7, the operation method of the purging device 1 according to the second embodiment includes an engine stopping step S11, an opening step S12, a second opening step S13, an inert gas supplying step S14, a mixing step S15, a determining step S16, a discharging step S17, and a purge completion determining step S18.

[0067] FIG. 8A is a diagram showing the state of the purging device 1 after the engine stopping step S11 has been performed. FIG. 8B is a diagram showing the state of the purging device 1 after the opening step S12 has been performed. FIG. 8C is a diagram showing the state of the purging device 1 after the second opening step S13 has been performed. FIG. 8D is a diagram showing the state of the purging device 1 after the inert gas supplying step S14 has been performed. FIG. 8E is a diagram showing the state of the purging device 1 after the mixing step S15 has been performed. FIG. 8F is a diagram showing the state of the purging device 1 after the discharge step S17 has been performed. In FIGS. 8A to 8F, the symbols of the fuel shutoff valve 4, the purge valve 20, the vent valve 22, the second fuel shutoff valve 24, the second purge valve 34, the second vent valve 36, and the fuel injection valve 106 are each painted white when open, and painted black when closed.

[0068] In the engine stop step S11, the fuel cutoff valve 4, the second fuel cutoff valve 24, and the fuel injection valve 106 are closed. In the second embodiment, when the operation of the gas engine 100 is stopped, the control device 150 transmits a valve close command to each of the fuel cutoff valve 4, the second fuel cutoff valve 24, and the fuel injection valve 106. The fuel cutoff valve 4, the second fuel cutoff valve 24, and the fuel injection valve 106 each receive the valve close command and close. Therefore, as shown in FIG. 8A, the fuel cutoff valve 4, the second fuel cutoff valve 24, the purge valve 20, the vent valve 22, the second purge valve 34, the second vent valve 36, and the fuel injection valve 106 are each in a closed state. Then, gas fuel F remains in the first purge target portion X1 and the second purge target portion X2. In some embodiments, the control device 150 is capable of detecting that the gas engine 100 has stopped operating, for example, by detecting that a power source (not shown) has been turned off.

[0069] In the opening step S12, after the engine stopping step S11, the vent valve 22 is opened. In the second embodiment, the control device 150 closes the fuel cutoff valve 4, the second fuel cutoff valve 24, and the fuel injection valve 106 by stopping the operation of the gas engine 100, and then transmits an open instruction to the vent valve 22. The vent valve 22 receives the open instruction and opens. Therefore, as shown in FIG. 8B, the fuel cutoff valve 4, the second fuel cutoff valve 24, the purge valve 20, the second purge valve 34, the second vent valve 36, and the fuel injection valve 106 are all closed, and the vent valve 22 is open. Then, a portion of the gas fuel F remaining in the first purge target portion X1 is discharged to the atmosphere via the vent line 8.

[0070] In a second opening step S13, after the opening step S12, the second vent valve 36 is opened. In the second embodiment, the control device 150 opens the vent valve 22 and then transmits an open instruction to the second vent valve 36. The second vent valve 36 receives the open instruction and opens. Therefore, as shown in FIG. 8C , the fuel shutoff valve 4, the second fuel shutoff valve 24, the purge valve 20, the second purge valve 34, and the fuel injection valve 106 are all closed, and the vent valve 22 and the second vent valve 36 are open. Then, a portion of the gaseous fuel F remaining in the second purge target portion X2 is discharged to the atmosphere via the second vent line 28.

[0071] In the inert gas supply step S14, after the second opening step S13, the vent valve 22 and the second vent valve 36 are closed, and the purge valve 20 and the second purge valve 34 are opened. In the second embodiment, after the second vent valve 36 is opened, a valve closing instruction is sent to the vent valve 22 and the second vent valve 36, and a valve opening instruction is sent to the purge valve 20 and the second purge valve 34. The vent valve 22 and the second vent valve 36 receive the valve closing instruction and close. The purge valve 20 and the second purge valve 34 receive the valve opening instruction and open. The purge valve 20 opens after the second purge valve 34 opens. 9D, the fuel cutoff valve 4, the second fuel cutoff valve 24, the vent valve 22, the second vent valve 36, and the fuel injection valve 106 are all closed, and the purge valve 20 and the second purge valve 34 are open. Then, the inert gas Gn is supplied to the fuel line 2.

[0072] In the mixing step S15, after the inert gas supply step S14, the purge valve 20 and the second purge valve 34 are closed to mix the inert gas Gn with the gas fuel F. In the second embodiment, the control device 150 opens the purge valve 20 and then transmits a valve closing instruction to the purge valve 20 and the second purge valve 34. The purge valve 20 and the second purge valve 34 receive the valve closing instruction and close. Therefore, as shown in FIG. 9E, the fuel shutoff valve 4, the purge valve 20, the vent valve 22, the second fuel shutoff valve 24, the second purge valve 34, the second vent valve 36, and the fuel injection valve 106 are all closed, and the first purge target portion X1 and the second purge target portion X2 are each sealed. Furthermore, the control device 150 maintains the sealed state of the first purge target portion X1 and the sealed state of the second purge target portion X2 for a predetermined time. The predetermined time may be a constant value that is set in advance, or may be a variable determined based on the measured values of the pressure sensor 80 and the second pressure sensor 32. The predetermined time for maintaining the sealed state of the first purge target portion X1 may be different from the predetermined time for maintaining the sealed state of the second purge target portion X2. By maintaining the sealed state of the first purge target portion X1 and the sealed state of the second purge target portion X2 for the predetermined time, the gas fuel F and the inert gas Gn are sufficiently mixed in each of the first purge target portion X1 and the second purge target portion X2.

[0073] In the determination step S16, between the mixing step S15 and the discharge step S17, it is determined whether an abnormality has occurred in at least one of the vent valve 22 and the fuel injection valve 106 based on the rate of decrease in the measurement value of the pressure sensor 80. At the same time, in the determination step S16, it is determined whether an abnormality has occurred in any of the fuel shutoff valve 4, the second fuel shutoff valve 24, the second purge valve 34, and the second vent valve 36 based on the rate of decrease in the measurement value of the second pressure sensor 32. In the second embodiment, the control device 150 acquires the measurement value of the pressure sensor 80 while the first purge target portion X1 is in a sealed state. At the same time, the control device 150 acquires the measurement value of the second pressure sensor 32 while the second purge target portion X2 is in a sealed state. The control device 150 then calculates the rate of decrease in the measurement value of the pressure sensor 80, and if the calculated rate of decrease is greater than a preset value, it is determined that an abnormality has occurred in at least one of the vent valve 22 and the fuel injection valve 106. Similarly, the control device 150 calculates the rate of decrease of the measurement value of the second pressure sensor 32, and if this calculated rate of decrease is greater than a preset value, determines that an abnormality has occurred in any of the fuel cutoff valve 4, the second fuel cutoff valve 24, the second purge valve 34, and the second vent valve 36. In some embodiments, if it is determined in the determination step S16 that an abnormality has occurred, the method further includes a notification step of notifying the occurrence of the abnormality.

[0074] In the discharge step S17, after the mixing step S15, the vent valve 22 and the second vent valve 36 are opened. In the second embodiment, the control device 150 transmits an open instruction to the vent valve 22 and the second vent valve 36 after a predetermined time has elapsed since the first purge target portion X1 and the second purge target portion X2 were sealed. The vent valve 22 and the second vent valve 36 receive the open instruction and open. The second vent valve 36 opens after the vent valve 22 opens. Therefore, as shown in FIG. 9F, the fuel shutoff valve 4, the purge valve 20, the second purge valve 34, and the fuel injection valve 106 are all closed, and the vent valve 22 and the second vent valve 36 are open. Then, the gas fuel F contained in the first purge target portion X1 is discharged to the atmosphere together with the inert gas Gn via the vent line 8, and the gas fuel F contained in the second purge target portion X2 is discharged to the atmosphere together with the inert gas Gn via the second vent line 28.

[0075] In the purge completion determination step S18, if the number of times that the discharge step S17 has been executed after the discharge step S17 exceeds a predetermined number of times (purge completion determination step S18: Yes), it is determined that the gas fuel F has been discharged, and if the number of times that the discharge step S17 has been executed is equal to or less than the predetermined number of times (purge completion determination step S18: No), the process returns to the inert gas supply step S14.

[0076] Although the purge completion determination step S18 determines whether the gaseous fuel F has been discharged based on the number of times the discharge step S17 has been performed, the present disclosure is not limited to this configuration. In some embodiments, the purge completion determination step S18 determines whether the gaseous fuel F has been discharged after the discharge step S17 based on the rate of decrease in the measurement value of the pressure sensor 80. Specifically, the control device 150 acquires the measurement value of the pressure sensor 80 until a certain period of time has elapsed since the second vent valve 36 was opened. The control device 150 then calculates the rate of decrease in the measurement value of the pressure sensor 80, and if this calculated rate of decrease is smaller than a preset value (purge completion determination step S18: Yes), determines that the gaseous fuel F has been discharged from the fuel line 2 and the engine-side fuel piping 104. If the rate of decrease in the measurement value of the pressure sensor 80 is greater than the preset value (purge completion determination step S18: No), the control device 150 returns to the inert gas supply step S14. In some embodiments, the purge completion determination step S18 determines whether the gaseous fuel F has been discharged, taking into consideration the rate of decrease in the measurement value of the second pressure sensor 32. In some embodiments, the purge completion determination step S18 determines whether the gaseous fuel F has been discharged after the discharge step S17, based on the measurement value of the concentration measurement device 90. That is, the purge completion determination step S18 determines that the gaseous fuel F has been discharged when the measurement value of the concentration measurement device 90 becomes lower than a predetermined concentration after the discharge step S17.

[0077] According to the operating method of the purging device 1 according to the second embodiment, when the gas engine 100 is stopped, the gas fuel F can be discharged from each of the first purged portion X1 and the second purged portion X2.

[0078] According to the operating method of the purge device 1 of the second embodiment, in the inert gas supply step S14, the second purge valve 34 and the purge valve 20 are opened in that order, so that the pressure of the second purge target portion X2 (upstream of the fuel line 2 from the fuel shutoff valve 4) is greater than or equal to the pressure of the first purge target portion X1 (downstream of the fuel line 2 from the fuel shutoff valve 4), thereby preventing backflow of the inert gas Gn.

[0079] According to the operating method of the purge device 1 of the second embodiment, in the discharge step S17, the vent valve 22 and the second vent valve 36 are opened in that order, so that the pressure of the second purged portion X2 (upstream of the fuel line 2 from the fuel shutoff valve 4) is greater than or equal to the pressure of the first purged portion X1 (downstream of the fuel line 2 from the fuel shutoff valve 4), thereby preventing backflow of the inert gas Gn.

[0080] The contents described in each of the above embodiments can be understood, for example, as follows.

[0081] [1] A purge device (1) for a gas engine (100) according to the present disclosure includes: a fuel line (2) connected to an engine inlet pipe (116) located at the most upstream position of an engine-side fuel pipe (104) of the gas engine, for supplying gas fuel (F) to the gas engine; a fuel cutoff valve (4) provided in the fuel line; a purge line (6) connected to a purge line connection portion (10) downstream of the fuel line from the fuel cutoff valve, for supplying an inert gas (Gn) to the fuel line and the engine-side fuel piping; and a vent line (8) for discharging the gas fuel from the fuel line and the engine side fuel piping, the vent line (8) being connected to a vent line connection portion (12) in the fuel line downstream of the fuel shutoff valve.

[0082] According to the configuration described in [1] above, the vent line is connected to the fuel line, so it is positioned away from the gas engine, and interference with components that form the outer periphery of the gas engine or components that are positioned around the gas engine is suppressed, making it easy to attach to the gas engine.

[0083] [2] In some embodiments, in the configuration described in [1] above, a second fuel cutoff valve (24) provided upstream of the fuel cutoff valve in the fuel line; a second purge line (26) connected to the fuel line between the fuel cutoff valve and the second fuel cutoff valve for supplying an inert gas (Gn) to the fuel line; The fuel supply system further includes a second vent line (28) connected to the fuel line between the fuel shutoff valve and the second fuel shutoff valve for discharging the gas fuel from the fuel line.

[0084] According to the configuration described in [2] above, it is possible to discharge the gas fuel contained in the portion of the fuel line between the fuel cutoff valve and the second fuel cutoff valve.

[0085] [3] In some embodiments, in the configuration described in [1] or [2] above, The fuel injection system further includes a mixing promoter (70) provided on the engine side fuel pipe upstream of a fuel injection valve (106) provided on the fuel line downstream of the fuel cutoff valve.

[0086] According to the configuration described in [3] above, when inert gas is supplied to the fuel line or the engine side fuel piping, the mixing of the inert gas and the gas fuel can be promoted, and the discharge of the gas fuel from the fuel line or the engine side fuel piping can be accelerated.

[0087] [4] In some embodiments, in the configuration described in [3] above, the purge line connection portion divides an area from the fuel cutoff valve to the fuel injection valve into a first area (R1) and a second area (R2) larger than the first area, The mixing promotion device is disposed on the purge line connection side of the second region.

[0088] According to the configuration described in [4] above, the inert gas flowing in from the purge line connection portion flows through the mixing promotion device and then flows toward the opposite side of the second region from the purge line connection portion side, thereby ensuring a large space for promoting mixing of the inert gas and the gas fuel, thereby enabling efficient mixing of the inert gas and the gas fuel.

[0089] [5] In some embodiments, in the configuration described in any one of [1] to [4] above, The fuel line includes a flexible pipe (126) disposed between the engine inlet pipe and the vent line connection.

[0090] According to the configuration described in [5] above, the transmission of vibrations of the gas engine to the vent line is suppressed, and damage to the vent line can be suppressed.

[0091] [6] In some embodiments, in the configuration described in any one of [1] to [5] above, The system further includes a check valve (60) provided in the vent line.

[0092] According to the configuration described in [6] above, it is possible to prevent gas (atmospheric air) outside the purge device from flowing into the fuel line via the vent line.

[0093] [7] In some embodiments, in the configuration described in [2] above, The system further includes a second check valve (30) provided in the second vent line.

[0094] According to the configuration described in [7] above, it is possible to prevent gas (atmosphere) outside the purge device from flowing into the fuel line via the second vent line.

[0095] [8] In some embodiments, in the configuration described in any one of [1] to [7] above, The vent line is located above the fuel line.

[0096] According to the configuration described in [8] above, when the gas fuel is a lightweight gas fuel such as hydrogen gas, the gas fuel can be easily caused to flow into the vent line.

[0097] [9] In some embodiments, in the configuration described in [2] or [7] above, The second vent line is located above the fuel line.

[0098] According to the configuration described in [9] above, when the gas fuel is a lightweight gas fuel such as hydrogen gas, the gas fuel can be easily caused to flow into the second vent line.

[0099]

[10] In some embodiments, in the configuration described in any one of [1] to [9] above, The fuel supply system further includes a pressure sensor (80) provided downstream of the fuel cutoff valve in the fuel line.

[0100] According to the configuration described in

[10] above, based on the measurement value of the pressure sensor, it is possible to detect whether or not an abnormality has occurred in the fuel shut-off valve, etc., and to confirm whether or not gas fuel is being discharged from the fuel line and the engine side fuel piping through the vent line.

[0101]

[11] In some embodiments, in the configuration described in any one of [2], [7], and [9] above, The fuel supply system further includes a second pressure sensor (32) provided in the fuel line between the fuel cutoff valve and the second fuel cutoff valve.

[0102] According to the configuration described in

[11] above, based on the measurement value of the second pressure sensor, it is possible to detect whether or not an abnormality has occurred in the fuel shut-off valve and the second fuel shut-off valve, etc., and to confirm whether or not gas fuel is being discharged from the fuel line via the second vent line.

[0103]

[12] In some embodiments, in the configuration according to any one of [1] to

[11] above, The engine-side fuel piping system further includes a concentration measuring device (90) that is provided on the engine-side fuel piping upstream of a fuel injection valve (106) provided in the engine-side fuel piping and that measures the concentration of the gas fuel.

[0104] When the vent line connection portion is located downstream of the fuel cutoff valve in the fuel line and the purge line connection portion is located downstream of the fuel cutoff valve in the fuel line, the gas fuel in the engine-side fuel piping is more difficult to discharge than the gas fuel in the fuel line. According to the configuration described in

[12] above, it is possible to confirm that the gas fuel is being discharged from the engine-side fuel piping based on the measurement value of the concentration measurement device.

[0105]

[13] A method for operating a purge device (1) according to the present disclosure includes: a fuel line (2) connected to an engine inlet pipe (116) located at the most upstream position of an engine-side fuel pipe (104) of the gas engine (100), for supplying gas fuel (F) to the gas engine; a fuel cutoff valve (4) provided in the fuel line; a purge line (6) connected to a purge line connection portion (10) downstream of the fuel line from the fuel cutoff valve, for supplying an inert gas (Gn) to the fuel line and the engine-side fuel piping; a vent line (10) for discharging the gas fuel from the fuel line and the engine-side fuel piping, the vent line (10) being connected to a vent line connection portion (12) in the fuel line downstream of the fuel cutoff valve; a purge valve (20) provided in the purge line; and a vent valve (22) provided in the vent line, an engine stopping step (S1) of closing the fuel cutoff valve and a fuel injection valve provided in the engine-side fuel pipe; an opening step (S2) of opening the vent valve after the engine stopping step; After the opening step, an inert gas supply step (S3) of closing the vent valve and opening the purge valve; a mixing step (S4) of closing the purge valve after the inert gas supply step and mixing the inert gas and the gas fuel; After the mixing step, a discharge step (S6) of opening the vent valve is provided.

[0106] According to the method described in

[13] above, when the gas engine is stopped, the gas fuel can be discharged from the fuel line and the engine-side fuel piping.

[0107]

[14] A method for operating a purge device according to the present disclosure includes: a fuel line (2) connected to an engine inlet pipe (116) located at the most upstream position of an engine-side fuel pipe (104) of the gas engine (100), for supplying gas fuel (F) to the gas engine; a fuel cutoff valve (4) provided in the fuel line; a second fuel cutoff valve (24) provided upstream of the fuel cutoff valve in the fuel line; a purge line (6) connected to a purge line connection portion (10) downstream of the fuel line from the fuel cutoff valve, for supplying an inert gas (Gn) to the fuel line and the engine-side fuel piping; a second purge line (26) connected to the fuel line between the fuel cutoff valve and the second fuel cutoff valve for supplying an inert gas (Gn) to the fuel line; a vent line (8) for discharging the gas fuel from the fuel line and the engine-side fuel piping, the vent line (8) being connected to a vent line connection portion (12) in the fuel line downstream of the fuel cutoff valve; a second vent line (28) connected to the fuel line between the fuel shutoff valve and the second fuel shutoff valve for discharging the gas fuel from the fuel line; a purge valve (20) provided in the purge line; a second purge valve (34) provided in the second purge line; a vent valve (22) provided in the vent line; a second vent valve (36) provided in the second vent line, an engine stopping step (S11) of closing the fuel cutoff valve, the second fuel cutoff valve, and a fuel injection valve provided in the engine-side fuel pipe; an opening step (S12) of opening the vent valve after the engine stopping step; After the opening step, a second opening step (S13) of opening the second vent valve; an inert gas supply step (S14) of closing the vent valve and the second vent valve and opening the purge valve and the second purge valve after the second opening step; a mixing step (S15) of closing the purge valve and the second purge valve after the inert gas supply step to mix the inert gas and the gas fuel; After the mixing step, a discharge step (S17) is provided in which the vent valve and the second vent valve are opened.

[0108] According to the method described in

[14] above, when the gas engine is stopped, gas fuel can be discharged from the fuel line and the engine-side fuel piping.

[0109]

[15] In some embodiments, in the method according to

[13] or

[14] above, the gas engine further includes a pressure sensor (80) provided downstream of the fuel cutoff valve in the fuel line; Between the mixing step and the discharging step, there is further provided a determination step (S5) of determining whether or not an abnormality has occurred in at least one of the vent valve and the fuel injection valve based on the rate of decrease in the measurement value of the pressure sensor.

[0110] According to the method described in

[15] above, it is possible to know whether or not an abnormality has occurred in at least one of the vent valve and the fuel injection valve.

[0111]

[16] In some embodiments, in the method according to

[13] or

[14] above, After the discharge step, a purge completion determination step is further provided in which it is determined that the gas fuel has been discharged if the number of times the discharge step has been performed exceeds a predetermined number, and if the number of times the discharge step has been performed is equal to or less than the predetermined number, the process returns to the inert gas supply step.

[0112] According to the method described in

[16] above, the timing for terminating the operation of the purge device can be set.

[0113]

[17] In some embodiments, in the method according to

[13] or

[14] above, a concentration measuring device that is provided on the engine-side fuel pipe upstream of a fuel injection valve that is provided on the engine-side fuel pipe and that measures the concentration of the gas fuel; The method further includes, after the discharging step, a purge completion determining step of determining that the gas fuel has been discharged based on the measurement value of the concentration measuring device.

[0114] According to the method described in

[17] above, the timing for terminating the operation of the purge device can be set.

[0115]

[18] In some embodiments, in the method according to

[13] or

[14] above, the gas engine further includes a pressure sensor (80) provided downstream of the fuel cutoff valve in the fuel line; After the discharging step, the method further includes a purge completion determining step (S7) of determining whether or not the gas fuel has been discharged based on the rate of decrease in the measurement value of the pressure sensor.

[0116] According to the method described in

[18] above, the timing for terminating the operation of the purge device can be set.

[0117]

[19] In some embodiments, in the method according to

[14] above, In the inert gas supplying step, the second purge valve is opened and then the purge valve is opened.

[0118] According to the method described in

[19] above, the condition that the pressure on the upstream side of the fuel line from the fuel shutoff valve is equal to or greater than the pressure on the downstream side of the fuel line from the fuel shutoff valve can be satisfied, thereby preventing backflow of inert gas.

[0119]

[20] In some embodiments, in the method according to

[14] or

[19] above, The discharge step opens the vent valve and then opens the second vent valve.

[0120] According to the method described in

[20] above, the condition that the pressure on the upstream side of the fuel line from the fuel shutoff valve is equal to or greater than the pressure on the downstream side of the fuel line from the fuel shutoff valve can be satisfied, thereby preventing backflow of inert gas. [Explanation of symbols]

[0121] 1 Purging device 2 fuel lines 4 Fuel shutoff valve 6 Purge Line 8 Vent Line 10 Purge line connection 11 Gas engine side purge line connection 12 Vent line connection 20 Purge valve 22 Vent valve 24 Second fuel shutoff valve 26 Second Purge Line 27 Second purge line connection 28 Second Vent Line 29 Second Vent Line Connection 30 Second check valve 32 Second pressure sensor 34 Second purge valve 36 Second vent valve 50 fuel source 52 Inert gas supply source 60 Check valve 70 Mixing accelerator 80 Pressure Sensor 90 Concentration measuring device 100 gas engine 101 Combustion chamber 104 Engine side fuel piping 106 Fuel injection valve 112 Piston 114 Cylinder head 116 Engine inlet pipe 118 Header pipe 120 Branch pipe 122 Engine side fuel pipe inlet 124 Engine side fuel pipe outlet 126 Flexible Pipe 150 control device F Gas fuel Gn inert gas R1 1st area R2 2nd area S1 Engine stop step (first embodiment) S2 Opening step (first embodiment) S3 Inert gas supply step (first embodiment) S4 Mixing step (first embodiment) S5 Determination step (first embodiment) S6 Discharge step (first embodiment) S7 Purge completion determination step (first embodiment) S11 Engine stop step (second embodiment) S12 Opening step (second embodiment) S13 Second opening step (second embodiment) S14 Inert gas supply step (second embodiment) S15 Mixing step (second embodiment) S16 Determination step (second embodiment) S17 Discharge step (second embodiment) S18: Purge completion determination step (second embodiment)

Claims

1. A purge device for a gas engine, a fuel line connected to an engine inlet pipe located at the most upstream of an engine-side fuel pipe of the gas engine, for supplying gas fuel to the gas engine; a fuel cutoff valve provided in the fuel line; a purge line connected to a purge line connection portion downstream of the fuel line relative to the fuel cutoff valve, for supplying an inert gas to the fuel line and the engine-side fuel piping; a vent line for discharging the gas fuel from the fuel line and the engine-side fuel piping, the vent line being connected to a vent line connection portion in the fuel line downstream of the fuel cutoff valve, Gas engine purging device.

2. a second fuel cutoff valve provided upstream of the fuel cutoff valve in the fuel line; a second purge line connected to the fuel line between the fuel shutoff valve and the second fuel shutoff valve for supplying an inert gas to the fuel line; a second vent line connected to the fuel line between the fuel shutoff valve and the second fuel shutoff valve for discharging the gas fuel from the fuel line. The purge device for a gas engine according to claim 1.

3. The engine further includes a mixing promotion device that is provided on the engine side fuel pipe upstream of a fuel injection valve that is provided on the fuel line downstream of the fuel cutoff valve.

3. The gas engine purge device according to claim 1 or 2.

4. the purge line connection portion divides an area from the fuel cutoff valve to the fuel injection valve into a first area and a second area larger than the first area, The mixing promotion device is disposed on the purge line connection side of the second region. The gas engine purge device according to claim 3.

5. the fuel line includes a flexible pipe disposed between the engine inlet pipe and the vent line connection.

3. The gas engine purge device according to claim 1 or 2.

6. Further comprising a check valve provided in the vent line.

3. The gas engine purge device according to claim 1 or 2.

7. further comprising a second check valve provided in the second vent line; The gas engine purge device according to claim 2.

8. The vent line is disposed above the fuel line.

3. The gas engine purge device according to claim 1 or 2.

9. The second vent line is disposed above the fuel line. The gas engine purge device according to claim 2 or 7.

10. a pressure sensor provided downstream of the fuel cutoff valve in the fuel line; 3. The gas engine purge device according to claim 1 or 2.

11. a second pressure sensor provided in the fuel line between the fuel cutoff valve and the second fuel cutoff valve; The gas engine purge device according to claim 2 or 7.

12. The engine-side fuel pipe further includes a concentration measuring device that is provided upstream of a fuel injection valve provided in the engine-side fuel pipe and that measures the concentration of the gas fuel.

3. The gas engine purge device according to claim 1 or 2.

13. a fuel line connected to an engine inlet pipe located at the most upstream of an engine-side fuel pipe of the gas engine, for supplying gas fuel to the gas engine; a fuel cutoff valve provided in the fuel line; a purge line connected to a purge line connection portion downstream of the fuel line relative to the fuel cutoff valve, for supplying an inert gas to the fuel line and the engine-side fuel piping; a vent line for discharging the gas fuel from the fuel line and the engine-side fuel piping, the vent line being connected to a vent line connection portion in the fuel line downstream of the fuel cutoff valve; a purge valve provided in the purge line; A vent valve provided in the vent line, an engine stopping step of closing the fuel cutoff valve and a fuel injection valve provided in the engine-side fuel pipe; an opening step of opening the vent valve after the engine stopping step; an inert gas supply step of closing the vent valve and opening the purge valve after the opening step; a mixing step of mixing the inert gas and the gas fuel by closing the purge valve after the inert gas supply step; After the mixing step, a discharge step of opening the vent valve is provided. A method for operating a purge device.

14. a fuel line connected to an engine inlet pipe located at the most upstream of an engine-side fuel pipe of the gas engine, for supplying gas fuel to the gas engine; a fuel cutoff valve provided in the fuel line; a second fuel cutoff valve provided upstream of the fuel cutoff valve in the fuel line; a purge line connected to a purge line connection portion downstream of the fuel line relative to the fuel cutoff valve, for supplying an inert gas to the fuel line and the engine-side fuel piping; a second purge line connected to the fuel line between the fuel shutoff valve and the second fuel shutoff valve for supplying an inert gas to the fuel line; a vent line for discharging the gas fuel from the fuel line and the engine-side fuel piping, the vent line being connected to a vent line connection portion in the fuel line downstream of the fuel cutoff valve; a second vent line connected to the fuel line between the fuel shutoff valve and the second fuel shutoff valve for discharging the gas fuel from the fuel line; a purge valve provided in the purge line; a second purge valve provided in the second purge line; a vent valve provided in the vent line; a second vent valve provided in the second vent line, an engine stopping step of closing the fuel cutoff valve, the second fuel cutoff valve, and a fuel injection valve provided in the engine-side fuel pipe; an opening step of opening the vent valve after the engine stopping step; a second opening step of opening the second vent valve after the opening step; an inert gas supply step of closing the vent valve and the second vent valve and opening the purge valve and the second purge valve after the second opening step; a mixing step of mixing the inert gas and the gas fuel by closing the purge valve and the second purge valve after the inert gas supply step; and a discharge step of opening the vent valve and the second vent valve after the mixing step. A method for operating a purge device.

15. The gas engine further includes a pressure sensor provided downstream of the fuel cutoff valve in the fuel line, a determination step, between the mixing step and the discharging step, of determining whether or not an abnormality has occurred in at least one of the vent valve and the fuel injection valve based on a rate of decrease in the measurement value of the pressure sensor; A method for operating a purge device according to claim 13 or 14.

16. a purge completion determination step of determining, after the discharge step, that the gas fuel has been discharged if the number of times the discharge step has been performed exceeds a predetermined number, and returning to the inert gas supply step if the number of times the discharge step has been performed is equal to or less than the predetermined number, A method for operating a purge device according to claim 13 or 14.

17. a concentration measuring device that is provided on the engine-side fuel pipe upstream of a fuel injection valve that is provided on the engine-side fuel pipe and that measures the concentration of the gas fuel; a purge completion determination step of determining, after the discharging step, that the gas fuel has been discharged based on a measurement value of the concentration measuring device, A method for operating a purge device according to claim 13 or 14.

18. The gas engine further includes a pressure sensor provided downstream of the fuel cutoff valve in the fuel line, a purge completion determination step of determining, after the discharging step, that the gas fuel has been discharged based on a rate of decrease in the measurement value of the pressure sensor, A method for operating a purge device according to claim 13 or 14.

19. the inert gas supply step includes opening the second purge valve and then opening the purge valve; 15. A method for operating a purge system according to claim 14.

20. the discharge step includes opening the vent valve and then opening the second vent valve.

15. A method for operating a purge system according to claim 14.

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