JP6373578B2 - Gaseous fuel supply system and abnormality detection method for gaseous fuel supply system - Google Patents

Description

  The present invention relates to a gaseous fuel supply system and an abnormality detection method for the gaseous fuel supply system.

  For example, a dual fuel engine (dual fuel engine) that generates power using both liquid fuel and gaseous fuel as disclosed in Patent Document 1 is known as a power source for ships.

Japanese Patent No. 3432098

  The dual fuel engine can be operated in a fuel oil only mode using only liquid fuel (fuel oil) and a two-fuel mode using both liquid fuel and gas fuel (fuel gas). The fuel oil only mode is a system in which liquid fuel is supplied to the combustion chamber and the supplied liquid fuel is burned. In the two-type fuel mode, a gaseous fuel is supplied to the combustion chamber, a small amount of liquid fuel is supplied to the combustion chamber to generate a pilot flame, and the gaseous fuel is ignited and burned by the pilot flame.

  In the dual fuel engine, even if an abnormality occurs in the gaseous fuel supply system that supplies the gaseous fuel to the combustion chamber, if the state is left as it is, the performance of the dual fuel engine may be deteriorated. Therefore, it is required to detect the presence / absence of abnormality of the gaseous fuel supply system and the site where the abnormality occurs.

  It is an object of the present invention to provide a gaseous fuel supply system that can detect an abnormality and an abnormality detection method for the gaseous fuel supply system.

  A gaseous fuel supply system according to the present invention is a gaseous fuel supply system that supplies gaseous fuel to a combustion chamber of an engine, an injection valve that injects the gaseous fuel into the combustion chamber, and the injection valve that is supplied to the injection valve. A supply flow path through which gaseous fuel flows, a gate valve capable of opening and closing the supply flow path, a pressure sensor for detecting pressure in the supply flow path between the injection valve and the gate valve, the injection valve, and the A control device that controls a gate valve, and based on a detection result of the pressure sensor and a detection result of a detection device that detects a crank angle of the crankshaft of the engine, at least one of the injection valve and the gate valve Detect abnormalities.

  According to the present invention, based on the detection result of the pressure of the supply flow path between the injection valve and the gate valve and the detection result of the crank angle of the crankshaft, at least one of the abnormality of the injection valve and the abnormality of the gate valve Can be detected. The abnormality of the injection valve and the gate valve includes a malfunction. Abnormality is, for example, a state where the valve is not opened despite the valve opening command signal being output from the control device, or a state where the valve is not closed despite the valve closing command signal being output from the control device. Including. According to the present invention, since these abnormalities can be detected, it is possible to take appropriate measures for eliminating the abnormalities. In addition, the inconvenience of continuing to use the gaseous fuel supply system in which an abnormality has occurred can be prevented.

  The control device obtains the position of the piston of the engine including the top dead center and the bottom dead center based on the detection result of the detection device, and the piston is top dead to supply the gaseous fuel to the combustion chamber. After opening the gate valve at a point in the vicinity of the point, the injection valve is opened, the injection valve is closed, and then a command signal is output to close the gate valve so that the piston is near the bottom dead center. The abnormality may be detected based on the detection result of the pressure sensor at the time of positioning. The gate valve functions as a safety valve (interlock mechanism) and operates when the piston is located near the top dead center. The injection valve operates with the gate valve open. Since the injection valve and the gate valve operate when the piston is located near the top dead center, at least one of the injection valve and the gate valve is based on the detection result of the pressure when the piston is located near the bottom dead center. Abnormalities can be detected smoothly. Since the position of the piston can be derived from the detection result of the detection device, an abnormality can be detected based on the detection result of the detection device and the detection result of the pressure sensor.

  In the gaseous fuel supply system according to the present invention, based on the detection result of the pressure sensor and the detection result of the in-cylinder sensor that detects the pressure of the combustion chamber, which of the injection valve and the gate valve has failed? May be determined. For example, if the pressure detection result when an abnormality occurs in the injection valve and the pressure detection result when an abnormality occurs in the gate valve are approximate, by detecting the pressure in the combustion chamber, Based on the pressure detection result, it is possible to determine which of the injection valve and the gate valve is abnormal.

  The gaseous fuel supply system according to the present invention includes a pre-injection valve that injects gaseous fuel into the combustion chamber before the injection of the gaseous fuel from the injection valve, and the control device injects the gaseous fuel. After closing the pre-injection valve and then closing the gate valve, a command signal is output to open the gate valve for injection of the gaseous fuel from the injection valve, and a command to close the pre-injection valve An abnormality of the pre-injection valve may be detected based on a detection result of the pressure sensor in a period from when a signal is output until a command signal for opening the gate valve is output. When the gaseous fuel supply system has a pre-injection valve, a command signal for closing the pre-injection valve is output, and then a command signal for opening the gate valve for injecting gaseous fuel from the injection valve is output. The abnormality of the pre-injection valve can be detected based on the detection result of the pressure sensor in the period until.

  In the gaseous fuel supply system according to the present invention, the engine includes a dual fuel engine, based on a detection result of the pressure sensor in a fuel oil only mode in which liquid fuel is supplied to the combustion chamber and the gaseous fuel is not supplied. An abnormality in the injection valve may be detected. In the fuel oil only mode, the gaseous fuel is not injected from the injection valve, and the injection valve is controlled to close. When the injection valve is open in the fuel oil only mode, the high-temperature and high-pressure gas in the combustion chamber flows from the injection valve into the supply flow path, and increases the pressure in the supply flow path. Therefore, it is possible to detect whether or not an abnormality has occurred in the injection valve in the fuel oil dedicated mode.

  An abnormality detection method for a gaseous fuel supply system according to the present invention is an abnormality detection method for a gaseous fuel supply system that supplies gaseous fuel to a combustion chamber of an engine, wherein the gaseous fuel supply system supplies gaseous fuel to the combustion chamber. An injection valve for injecting, a supply flow path through which the gaseous fuel supplied to the injection valve flows, and a gate valve capable of opening and closing the supply flow path, and between the injection valve and the gate valve Based on the step of detecting the pressure of the supply passage, the step of detecting the crank angle of the crankshaft of the engine, the detection result of the pressure of the supply passage and the detection result of the crank angle, Detecting an abnormality of at least one of the gate valves.

  According to the present invention, at least one of the abnormality of the injection valve and the abnormality of the gate valve is detected based on the detection result of the pressure in the supply flow path between the injection valve and the gate valve and the detection result of the crank angle. be able to.

  According to the present invention, the abnormality of the gaseous fuel supply system can be detected smoothly.

FIG. 1 is a schematic diagram illustrating an example of a dual fuel engine. FIG. 2 is a schematic diagram showing an example of the operation of the dual fuel engine. FIG. 3 is a plan view schematically showing an example of a state in which fuel is injected into the combustion chamber in the two-type fuel mode. FIG. 4 is a diagram schematically illustrating an example of a state in which fuel is combusted in the two-type fuel mode. FIG. 5 is a plan view schematically showing an example of a state in which fuel is combusted in the two-type fuel mode. FIG. 6 is a schematic diagram illustrating an example of a gaseous fuel supply system. FIG. 7 is a diagram showing the relationship between the crank angle and the pressure in the supply flow path when the gaseous fuel injection valve and the gate valve are operating normally. FIG. 8 is a diagram showing the relationship between the crank angle and the supply flow path pressure when the gate valve is abnormally opened. FIG. 9 is a diagram showing the relationship between the crank angle and the supply flow path pressure when the gate valve is abnormally closed. FIG. 10 is a diagram showing the relationship between the crank angle and the supply flow path pressure when the gaseous fuel injection valve is abnormally opened. FIG. 11 is a diagram showing the relationship between the crank angle and the pressure in the supply flow path when the gaseous fuel injection valve is abnormally closed. FIG. 12 is a diagram showing the relationship between the crank angle and the pressure in the supply flow path when the gaseous fuel injection valve is abnormally opened in the fuel oil dedicated mode. FIG. 13 is a schematic diagram illustrating an example of a gaseous fuel supply system. FIG. 14 is a diagram showing the relationship between the crank angle and the supply flow path pressure when the pre-injection valve is abnormally opened. FIG. 15 is a diagram illustrating the relationship between the crank angle and the supply flow path pressure when the pre-injection valve is abnormally closed.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings, but the present invention is not limited thereto. The requirements of the embodiments described below can be combined as appropriate. Some components may not be used.

<First Embodiment>
A first embodiment will be described. FIG. 1 is a schematic diagram illustrating an example of a dual fuel engine 1 according to the present embodiment. The dual fuel engine 1 according to the present embodiment includes a crosshead type diesel engine, and is used as a propulsion engine for a ship or the like, for example.

  The dual fuel engine 1 includes a base plate 50, a frame (main body) 51 provided on the base plate 50, and a jacket 52 provided on the frame 51.

  The dual fuel engine 1 includes a cylinder 2 provided in a jacket 52, a piston 3 that reciprocates inside the cylinder 2, a piston rod 41 connected to the piston 3, a connecting rod 43, a piston rod 41, A cross head 42 for connecting the connecting rod 43 and a crankshaft 4 connected to the connecting rod 43 via a crank pin 44 are provided.

  The cylinder 2 includes a cylinder liner 2A provided on the jacket 52 and a cylinder cover 2B provided on the cylinder liner 2A. The cross head 42 moves along the guide portion 51G provided on the frame 51 and transmits the mechanical power from the piston rod 41 to the connecting rod 43. The crankshaft 4 is disposed on the base plate 50 and outputs mechanical power transmitted from the piston 3.

  The top surface of the piston 3 and the ceiling surface of the cylinder 2 face each other. An exhaust valve 11 is provided at the center of the ceiling surface of the cylinder 2. A combustion chamber 7 is formed between the piston 3, the cylinder 2 and the exhaust valve 11.

  The dual fuel engine 1 includes a detection device 6 that detects a rotation angle (crank angle) of the crankshaft 4, a gaseous fuel supply system 15 that includes a gaseous fuel injection valve 8 that supplies gaseous fuel PG to the combustion chamber 7, and A liquid fuel supply system 20 including a liquid fuel injection valve 9 that supplies liquid fuel FO to the combustion chamber 7, an in-cylinder sensor 16 that detects the pressure in the combustion chamber 7, and a control device 10 that controls the dual fuel engine 1. I have.

The gaseous fuel injection valve 8 can inject gaseous fuel PG into the combustion chamber 7. The gaseous fuel PG includes, for example, at least one of CNG (compressed natural gas) and H ₂ (hydrogen gas). In the present embodiment, two gaseous fuel injection valves 8 are arranged in the combustion chamber 7. The number of gaseous fuel injection valves 8 is arbitrary.

  The liquid fuel injection valve 9 can inject liquid fuel FO into the combustion chamber 7. The liquid fuel FO includes, for example, at least one of light oil, heavy oil, and heavy oil. In the present embodiment, two liquid fuel injection valves 9 are arranged in the combustion chamber 7. The number of liquid fuel injection valves 9 is arbitrary.

  The detection device 6 includes a crank angle sensor and detects the crank angle of the crankshaft 4. The detection device 6 may detect the crank angle with reference to the top dead center of the piston 3. For example, the crank angle sensor detects a crank angle from a rotational position of a measurement member (a disk, a detection gear, etc.) attached to the crankshaft 4 and outputs a crank angle signal. The crank angle sensor may be optical or electromagnetic. The detection device 6 may detect the crank angle from the rotational position of the crankshaft 4 or the position of the piston 3. Further, the position information (reference position information) of the crankshaft 4 when the piston 3 is located at the top dead center is detected using the top dead center sensor, and based on the position information and the rotational speed information of the crankshaft 4. The crank angle may be obtained.

  The detection result of the detection device 6 is output to the control device 10. The crank angle and the position of the piston 3 are associated with each other. The control device 10 can determine the position of the piston 3 including the top dead center and the bottom dead center based on the detection result of the detection device 6. Moreover, the control apparatus 10 is based on the output of the built-in timer and the detection result of the detection apparatus 6, for example, when the piston 3 is disposed at the top dead center and when it is disposed at the bottom dead center. Can be requested. The control device 10 controls the opening / closing of the exhaust valve 11, the injection of the gaseous fuel PG from the gaseous fuel injection valve 8, and the injection of the liquid fuel FO from the liquid fuel injection valve 9 based on the crank angle. Is output.

  The in-cylinder sensor 16 detects the pressure in the combustion chamber 7. The detection result of the in-cylinder sensor 16 is input to the control device 10. The control device 10 can determine whether there is an abnormality in the combustion chamber 7 based on the detection result of the in-cylinder sensor 16. The control device 10 can obtain the type (content) of the abnormality in the combustion chamber 7 based on the detection result of the in-cylinder sensor 16.

  The abnormality of the combustion chamber 7 includes at least one of combustion abnormality, excessive supply of gaseous fuel, and insufficient supply of gaseous fuel. Combustion abnormalities include misfires. The pressure of the combustion chamber 7 is different depending on whether the combustion chamber 7 is normal or abnormal. The pressure in the combustion chamber 7 also varies depending on the type of abnormality in the combustion chamber 7. In this embodiment, the relationship between the type of abnormality in the combustion chamber 7 and the pressure in the combustion chamber 7 corresponding to the type of abnormality is obtained in advance. The relationship is obtained by a preliminary experiment or simulation and is stored in a storage device connected to the control device 10. The control device 10 can determine the presence / absence of an abnormality in the combustion chamber 7 based on the detection result of the in-cylinder sensor 16 and the storage information in the storage device, and can determine the type of abnormality when an abnormality has occurred. It is.

  FIG. 2 is a schematic diagram illustrating an example of the operation of the dual fuel engine 1. In the present embodiment, the dual fuel engine 1 is a two-stroke one-cycle uniflow scavenging diesel engine, and new air is introduced into the combustion chamber 7 from the scavenging port when the piston 3 is disposed near the bottom dead center. During the transition from the top dead center to the bottom dead center, the gas in the combustion chamber 7 is discharged from the exhaust port. The operation of the dual fuel engine 1 includes an intake process (A) for taking in new air and sending it to the combustion chamber 7, a compression process (B) for compressing the air in the combustion chamber 7 with the piston 3, and injecting fuel into the combustion chamber 7. The combustion process (C) for burning the fuel and the exhaust process (D) for discharging the gas in the combustion chamber 7 after the combustion process from the exhaust valve 11 are included.

  The dual fuel engine 1 can be operated in a fuel oil only mode using only the liquid fuel FO and a two-fuel mode using both the liquid fuel FO and the gaseous fuel PG.

  The fuel oil dedicated mode is a mode in which the liquid fuel FO is supplied from the liquid fuel injection valve 9 to the combustion chamber 7 to burn the liquid fuel FO, while the gaseous fuel PG is not supplied from the gaseous fuel injection valve 8 to the combustion chamber 7. . In the fuel oil only mode, after the air in the combustion chamber 7 is compressed in the compression process, the liquid fuel FO is injected from the liquid fuel injection valve 9 into the combustion chamber 7 in the combustion process. When the liquid fuel FO is injected into the high-temperature and high-pressure air, the liquid fuel FO spontaneously ignites and burns.

  The two-type fuel mode is a mode in which both the liquid fuel FO and the gaseous fuel PG are supplied to the combustion chamber 7. In the two-type fuel mode, after the gaseous fuel PG is injected from the gaseous fuel injection valve 8 into the combustion chamber 7, a small amount of liquid fuel FO is injected from the liquid fuel injection valve 9 into the fuel chamber 7 to generate a pilot flame. The gaseous fuel PG is ignited and burned with a pilot flame.

  Next, details of the two-fuel mode will be described with reference to FIGS. 3, 4, and 5. FIG. 3 schematically shows an example of a state in which the gaseous fuel PG is injected from the gaseous fuel valve 8 to the combustion chamber 7 and the liquid fuel FO is injected from the liquid fuel valve 9 to the combustion chamber 7 in the two-fuel mode. FIG. FIG. 4 is a diagram schematically illustrating an example of a state in which each of the liquid fuel FO and the gaseous fuel PG is burning in the two-type fuel mode. FIG. 5 is a plan view schematically showing an example of a state in which the liquid fuel FO and the gaseous fuel PG are burning in the two-type fuel mode.

  In the compression process, the air in the combustion chamber 7 is compressed. As shown in FIG. 3, in the combustion process, gaseous fuel PG is injected from the gaseous fuel injection valve 8 into the combustion chamber 7. A small amount of liquid fuel FO is injected from the liquid fuel injection valve 9 into the combustion chamber 7. When the piston 3 is disposed in the vicinity of the top dead center, the liquid fuel FO and the gaseous fuel PG are injected into the combustion chamber 7 almost simultaneously. In the dual fuel mode, the main fuel is the gaseous fuel PG.

  As shown in FIG. 3, the gaseous fuel injection valve 8 has a plurality of injection ports 8S for injecting the gaseous fuel PG. The liquid fuel injection valve 9 has a plurality of injection ports 9S that inject the liquid fuel FO. The gaseous fuel injection valve 8 injects the gaseous fuel PG outward with respect to the radial direction with respect to the axis of the gaseous fuel injection valve 8. The liquid fuel injection valve 9 injects the liquid fuel FO outward in the radial direction with respect to the axis of the liquid fuel injection valve 9. Each of the gaseous fuel injection valve 8 and the liquid fuel injection valve 9 injects the gaseous fuel PG and the liquid fuel FO so that the gaseous fuel PG and the liquid fuel FO intersect each other.

  A small amount of the liquid fuel FO injected from the liquid fuel injection valve 9 spontaneously ignites and generates a pilot flame. The gaseous fuel injection valve 8 injects gaseous fuel PG having a pressure P1. By supplying high-pressure gaseous fuel PG to the combustion chamber 7 filled with high-temperature and high-pressure air and generating a pilot flame, diffusion combustion occurs in the combustion chamber 7 as shown in FIGS. . In the present embodiment, the two-fuel mode combusts the gaseous fuel PG by a diffusion combustion method.

  Next, an example of the gaseous fuel supply system 15 according to the present embodiment will be described. FIG. 6 is a diagram illustrating an example of the gaseous fuel supply system 15 according to the present embodiment.

  The gaseous fuel supply system 15 supplies gaseous fuel PG to the combustion chamber 7 of the dual fuel engine 1. The gaseous fuel supply system 15 is controlled by the control device 10. The gaseous fuel supply system 15 includes a gaseous fuel injection valve 8 that injects gaseous fuel PG into the combustion chamber 7, a supply flow path 21 through which the gaseous fuel PG supplied to the gaseous fuel injection valve 8 flows, and opens and closes the supply flow path 21. A possible gate valve 22 and a pressure sensor 23 for detecting the pressure of the supply passage 21 between the gaseous fuel injection valve 8 and the gate valve 22 are provided. The gaseous fuel injection valve 8 and the gate valve 22 are controlled by the control device 10. The detection result of the pressure sensor 23 is output to the control device 10. The gate valve 22 is connected to a gaseous fuel supply source including a pump capable of delivering the gaseous fuel PG. The gaseous fuel supply source supplies the gaseous fuel PG to the gate valve 22. The gaseous fuel supply source supplies gaseous fuel PG having a pressure P1.

  The gate valve 22 functions as a safety valve (interlock mechanism). When both the gaseous fuel injection valve 8 and the gate valve 22 are opened, the gaseous fuel PG from the gaseous fuel supply source enters the combustion chamber 7 via the gate valve 22, the supply flow path 21, and the gaseous fuel injection valve 8. Supplied.

  The pressure sensor 23 detects the pressure in the supply flow path 21 between the gaseous fuel injection valve 8 and the gate valve 22. The pressure sensor 23 can detect the pressure at the inlet of the gaseous fuel injection valve 8. The detection result of the pressure sensor 23 is output to the control device 10. In the present embodiment, the control device 10 detects an abnormality in at least one of the gaseous fuel injection valve 8 and the gate valve 22 based on the detection result of the pressure sensor 23 and the detection result of the detection device 6.

  FIG. 7 is a diagram showing the relationship between the crank angle when the gaseous fuel injection valve 8 and the gate valve 22 are operating normally, and the pressure of the supply passage 21 (pressure at the inlet of the gaseous fuel injection valve 8). is there. FIG. 7 includes a timing chart of the opening / closing operation of the gaseous fuel injection valve 8 and the opening / closing operation of the gate valve 22.

  In FIG. 7, when the crank angle is 0 degree, the piston 3 is disposed at the top dead center. When the crank angle is 180 degrees (or -180 degrees), the piston 3 is disposed at the bottom dead center. FIG. 7 shows the pressure in the supply flow path 21 between the gaseous fuel injection valve 8 and the gate valve 22 when the crank angle is in the range of −30 degrees to 90 degrees.

  In order to supply the gaseous fuel PG to the combustion chamber 7, the control device 10 outputs a command signal to open the gaseous fuel injection valve 8 after opening the gate valve 22. The control device 10 opens the gate valve 22 when the piston 3 is located near the top dead center. In FIG. 7, when the crank angle becomes A1 degrees, the control device 10 outputs a command signal to open the gate valve 22. Further, the control device 10 opens the gaseous fuel injection valve 8 when the piston 3 is located near the top dead center. In FIG. 7, when the crank angle becomes A2 degrees, the control device 10 outputs a command signal to open the gaseous fuel injection valve 8. In a period T1 from when the crank angle becomes A1 degrees to A2 degrees, the gate valve 22 is open and the gaseous fuel injection valve 8 is closed.

  The gate valve 22 is supplied with gaseous fuel PG having a pressure P1 from a gaseous fuel supply source. When the gate valve 22 is opened while the gaseous fuel injection valve 8 is closed, the pressure in the supply passage 21 between the gaseous fuel injection valve 8 and the gate valve 22 becomes the pressure P1 in the period T1.

  When the crank angle reaches A2 degrees, the gaseous fuel injection valve 8 is opened while the gate valve 22 is open, so that the gaseous fuel PG is injected from the gaseous fuel injection valve 8 into the combustion chamber 7. In the present embodiment, the crank angle A2 is 0 degree. That is, when the piston 3 is disposed at the top dead center, the gaseous fuel PG is injected from the gaseous fuel injection valve 8. The crank angle A2 may not be 0 degrees. When the gaseous fuel injection valve 8 is opened and the gaseous fuel PG is injected, the pressure of the supply flow path 21 between the gaseous fuel injection valve 8 and the gate valve 22 decreases.

  The control device 10 outputs a command signal so as to close the gate valve 22 after closing the gaseous fuel injection valve 8. In FIG. 7, when the crank angle reaches A3 degrees, the control device 10 outputs a command signal to close the gaseous fuel injection valve 8. When the crank angle becomes A4 degrees larger than A3 degrees, the control device 10 outputs a command signal so as to close the gate valve 22.

  In the period T2 from when the crank angle becomes A2 degrees to A3 degrees, both the gaseous fuel injection valve 8 and the gate valve 22 are open. In the period T2, the pressure in the supply flow path 21 between the gaseous fuel injection valve 8 and the gate valve 22 gradually decreases.

  When the crank angle reaches A3 degrees, the control device 10 closes the gaseous fuel injection valve 8 while the gate valve 22 is open. As a result, the pressure in the supply flow path 21 between the gaseous fuel injection valve 8 and the gate valve 22 gradually increases during a period T3 from when the crank angle becomes A3 degrees to A4 degrees.

  When the crank angle reaches A4 degrees, the control device 10 closes the gate valve 22 while the gaseous fuel injection valve 8 is closed. Thereby, in the period T4 after the period T3, the pressure of the supply flow path 21 between the gaseous fuel injection valve 8 and the gate valve 22 becomes constant. In this embodiment, the gate valve 22 is closed before the pressure of the supply flow path 21 between the gaseous fuel injection valve 8 and the gate valve 22 rises to the pressure P1. In the present embodiment, the pressure in the supply channel 21 in the period T4 is a pressure P2 that is lower than the pressure P1.

  In the present embodiment, the period T1 includes a period from when the command signal for opening the gate valve 22 is output to when the command signal for opening the gaseous fuel injection valve 8 is output. The period T2 includes a period from when the command signal for opening the gaseous fuel injection valve 8 is output to when the command signal for closing the gaseous fuel injection valve 8 is output. The period T3 includes a period from when the command signal for closing the gaseous fuel injection valve 8 is output to when the command signal for closing the gate valve 22 is output. The period T4 includes a period from when the command signal for closing the gate valve 22 is output to when the command signal for opening the gate valve 22 is output in the next cycle. The control device 10 determines the timing for outputting the command signal based on the detection result of the detection device 6.

  Next, an abnormality detection method for the gaseous fuel injection valve 8 and the gate valve 22 will be described. FIG. 8 is a diagram illustrating an abnormality (open abnormality) in which the gate valve 22 is open even though the control device 10 has output a command signal for closing the gate valve 22. In FIG. 8, the horizontal axis is the crank angle, and the vertical axis is the pressure in the supply passage 21 between the gaseous fuel injection valve 8 and the gate valve 22 (pressure at the inlet of the gaseous fuel injection valve 8).

  As described with reference to FIG. 7, the control device 10 outputs a command signal for opening the gate valve 22 when the crank angle is A1 degrees, and opens the gaseous fuel injection valve 8 when the crank angle is A2 degrees. When the crank angle is A3 degrees, a command signal for closing the gaseous fuel injection valve 8 is output, and when the crank angle is A4 degrees, a command signal for closing the gate valve 22 is output.

  Even when a command signal for closing the gate valve 22 is output from the control device 10 at the crank angle A4, if the gate valve 22 is not closed, the gaseous fuel at the pressure P1 from the gaseous fuel supply source even in the period T4. PG is supplied to the supply channel 21. Thereby, as shown in FIG. 8, the pressure of the supply flow path 21 in the period T4 becomes the pressure P1.

  The period T4 includes a time point when the piston 3 is located near the bottom dead center. That is, the period T4 includes a time point when the crank angle is 180 degrees. As described above, the pressure in the supply flow path 21 during the period T4 when the gaseous fuel injection valve 8 and the gate valve 22 are operating normally is the pressure P2. Thus, the pressure of the supply flow path 21 in the period T4 differs depending on whether the gate valve 22 is abnormal (open abnormality) or normal. That is, when the gate valve 22 is normal, the pressure of the supply flow path 21 in the period Th (period T4) is the pressure P2, as shown by the solid line in FIG. 8, and when the gate valve 22 is abnormally open, The pressure of the supply flow path 21 in the period Th is a pressure P1 higher than the pressure P2, as indicated by a dotted line in FIG. Therefore, the control device 10 determines whether or not the gate valve 22 is abnormal based on the detection result of the pressure sensor 23 in at least a partial period Th of the period T4 when the piston 3 is disposed near the bottom dead center. Can be detected.

  Next, an abnormality (closing abnormality) in which the gate valve 22 is closed even though the control device 10 outputs a command signal for opening the gate valve 22 will be described. FIG. 9 is a diagram showing the relationship between the crank angle and the pressure in the supply flow path 21 (pressure at the inlet of the gaseous fuel injection valve 8) when the gate valve 22 is abnormally closed.

  If the command signal for opening the gate valve 22 is output from the control device 10 at the crank angle A1, the gate valve 22 is not opened, and the gas fuel injection valve 8 is opened at the crank angle A2 at the crank angle A2. With the valve 22 closed, the gaseous fuel PG in the supply passage 21 is injected from the gaseous fuel injection valve 8 into the combustion chamber 7. As a result, as shown in FIG. 9, the pressure in the supply flow path 21 decreases from the point of the crank angle A2. Thus, the pressure of the supply flow path 21 in the period T2, the period T3, and the period T4 (period Th) differs depending on whether the gate valve 22 is abnormal (closed abnormality) or normal. That is, when the gate valve 22 is normal, the pressure in the supply flow path 21 in the period Th (period T4) is the pressure P2, as shown by the solid line in FIG. 9, and when the gate valve 22 is abnormally closed, The pressure of the supply flow path 21 in the period Th is lower than the pressure P2, as indicated by a dotted line in FIG. In this example, also in the period T2 and the period T3, the pressure of the supply flow path 21 when the gate valve 22 is abnormally closed is lower than the pressure of the supply flow path 21 when the gate valve 22 is normal. Therefore, for example, the control device 10 can detect whether or not the gate valve 22 is abnormal based on the detection result of the pressure sensor 23 in the period Th.

  Next, an abnormality (opening abnormality) in which the gaseous fuel injection valve 8 is opened even though the control device 10 outputs a command signal for closing the gaseous fuel injection valve 8 will be described. FIG. 10 is a diagram showing the relationship between the crank angle and the pressure in the supply flow path 21 (pressure at the inlet of the gaseous fuel injection valve 8) when the gaseous fuel injection valve 8 is abnormally opened.

  When the control signal is output from the control device 10 to close the gaseous fuel injection valve 8 at the crank angle A3, the gaseous fuel injection valve 8 is not closed, and at the crank angle A4, the gate valve 22 is closed. In the state where the gate valve 22 is closed, the gaseous fuel PG in the supply passage 21 is injected from the gaseous fuel injection valve 8 into the combustion chamber 7. As a result, as shown in FIG. 10, the pressure in the supply flow path 21 decreases from the time of the crank angle A3. Thus, the pressure of the supply flow path 21 in the period T3 and the period T4 (period Th) differs depending on whether the gaseous fuel injection valve 8 is abnormal (open abnormality) or normal. That is, when the gaseous fuel injection valve 8 is normal, the pressure in the supply flow path 21 in the period Th (period T4) becomes the pressure P2 as shown by the solid line in FIG. 10, and the gaseous fuel injection valve 8 is abnormally opened. In such a case, the pressure in the supply channel 21 during the period Th is lower than the pressure P2, as indicated by a dotted line in FIG. In this example, also in the period T3, the pressure of the supply flow path 21 when the gaseous fuel injection valve 8 is abnormally open is lower than the pressure of the supply flow path 21 when the gaseous fuel injection valve 8 is normal. . Therefore, for example, the control device 10 can detect whether or not the gate valve 22 is abnormal based on the detection result of the pressure sensor 23 in the period Th.

  Next, an abnormality (closing abnormality) in which the gaseous fuel injection valve 8 is closed even though the control device 10 has output a command signal for opening the gaseous fuel injection valve 8 will be described. FIG. 11 is a diagram showing the relationship between the crank angle and the pressure of the supply flow path 21 (pressure at the inlet of the gaseous fuel injection valve 8) when the gaseous fuel injection valve 8 is abnormally closed.

  If the command signal for opening the gaseous fuel injection valve 8 is output from the control device 10 at the crank angle A2, the gaseous fuel injection valve 8 is closed and the gate valve 22 is opened if the gaseous fuel injection valve 8 is not opened. In the open state, the gaseous fuel PG having the pressure P1 from the gaseous fuel supply source is supplied to the supply flow path 21. Thereby, as shown in FIG. 11, the pressure of the supply flow path 21 in the period T2, the period T3, and the period T4 (period Th) becomes the pressure P1. Thus, the pressure of the supply flow path 21 in the period T2, the period T3, and the period T4 (period Th) differs depending on whether the gaseous fuel injection valve 8 is abnormal (closed abnormality) or normal. That is, when the gaseous fuel injection valve 8 is normal, the pressure in the supply flow path 21 in the period Th (period T4) becomes the pressure P2, as indicated by the solid line in FIG. 11, and the gaseous fuel injection valve 8 is abnormally closed. In such a case, the pressure in the supply channel 21 in the period Th is a pressure P1 higher than the pressure P2, as indicated by a dotted line in FIG. In this example, also in the period T2 and the period T3, the pressure of the supply flow path 21 when the gaseous fuel injection valve 8 is abnormally closed is higher than the pressure of the supply flow path 21 when the gaseous fuel injection valve 8 is normal. Also gets higher. Therefore, for example, the control device 10 can detect whether or not the gate valve 22 is abnormal based on the detection result of the pressure sensor 23 in the period Th.

  In the present embodiment, the pressure shown in FIG. 8 (pressure when the gate valve 22 is abnormally open) and the pressure shown in FIG. 11 (pressure when the gaseous fuel injection valve 8 is abnormally closed) are the period T2 and the period T3. , But approximate in the period T4. Therefore, it may be difficult to determine which of the gate valve 22 and the gaseous fuel injection valve 8 is abnormal based on the detection result of the pressure sensor 23 in the period T4.

  In that case, the control device 10 generates an abnormality in either the gaseous fuel injection valve 8 or the gate valve 22 based on the detection result of the pressure sensor 23 and the detection result of the in-cylinder sensor 16 that detects the pressure in the combustion chamber 7. It may be determined. The pressure in the combustion chamber 7 differs depending on whether the gate valve 22 is abnormally opened or the gaseous fuel injection valve 8 is abnormally closed. For example, when the gaseous fuel injection valve 8 is abnormally closed, the gaseous fuel PG is not injected from the gaseous fuel injection valve 8 into the combustion chamber 7, so that the possibility of misfire in the combustion chamber 7 increases. On the other hand, when the gate valve 22 is abnormally open, the gaseous fuel PG is supplied to the combustion chamber 7 via the gate valve 22 and the gaseous fuel injection valve 8, so that the possibility of misfire in the combustion chamber 7 is low. Thus, it is highly possible that the type of abnormality in the combustion chamber 7 is different between when the gate valve 22 is abnormally opened and when the gaseous fuel injection valve 8 is abnormally closed. Further, as described above, the pressure in the combustion chamber 7 varies depending on the type of abnormality in the combustion chamber 7. Therefore, when the detection result of the pressure sensor 23 when abnormality occurs in the gaseous fuel injection valve 8 and the detection result of the pressure sensor 23 when abnormality occurs in the gate valve 22, combustion by the in-cylinder sensor 16 is performed. Based on the detection result of the pressure in the chamber 7, it can be determined which of the gaseous fuel injection valve 8 and the gate valve 22 is abnormal.

  As described above, the relationship between the type of abnormality in the combustion chamber 7 and the pressure in the combustion chamber 7 corresponding to the type of abnormality is stored in the storage device. The control device 10 can determine which of the gaseous fuel injection valve 8 and the gate valve 22 is abnormal based on the detection result of the in-cylinder sensor 16 and the stored information in the storage device.

  Further, although the pressure shown in FIG. 9 (pressure when the gate valve 22 is abnormally closed) and the pressure shown in FIG. 10 (pressure when the gaseous fuel injection valve 8 is abnormally open) are different in the period T2, the period T4 is different. Approximate. Therefore, it may be difficult to determine which of the gate valve 22 and the gaseous fuel injection valve 8 is abnormal based on the detection result of the pressure sensor 23 in the period T4.

  Even in that case, the type of abnormality in the combustion chamber 7 is different and the pressure in the combustion chamber 7 is different between when the gate valve 22 is abnormally closed and when the gaseous fuel injection valve 8 is abnormally opened. For example, when the gate valve 22 is abnormally closed, the gaseous fuel PG is not supplied from the gate valve 22 to the gaseous fuel injection valve 8, so that the possibility of misfire in the combustion chamber 7 increases. On the other hand, since the gaseous fuel PG is injected from the gaseous fuel injection valve 8 into the combustion chamber 7 when the gaseous fuel injection valve 8 is abnormally open, the possibility of misfire in the combustion chamber 7 is low. Therefore, the control device 10 can determine which of the gaseous fuel injection valve 8 and the gate valve 22 is abnormal based on the detection result of the in-cylinder sensor 16 and the stored information in the storage device.

  As described above, according to the present embodiment, the gaseous fuel injection is performed based on the detection result of the pressure in the supply passage 21 between the gaseous fuel injection valve 8 and the gate valve 22 and the detection result of the crank angle. At least one of the abnormality of the valve 8 and the abnormality of the gate valve 22 can be detected. Therefore, for example, it is possible to take appropriate measures for eliminating the abnormality. In addition, the inconvenience of continuing to use the gaseous fuel supply system 15 in which an abnormality has occurred can be prevented.

  In the present embodiment, the gate valve 22 functions as a safety valve (interlock mechanism) and operates when the piston 3 is disposed in the vicinity of the top dead center in order to inject the gaseous fuel PG. Since the gaseous fuel injection valve 8 operates with the gate valve 22 open, the gaseous fuel PG is injected from the gaseous fuel injection valve 8 into the combustion chamber 7 at an appropriate timing. Since the gaseous fuel injection valve 8 and the gate valve 22 operate in a state where the piston 3 is arranged near the top dead center, the pressure sensor 23 of the period Th when the piston 3 is arranged near the bottom dead center Based on the detection result, an abnormality in at least one of the gaseous fuel injection valve 8 and the gate valve 22 can be detected smoothly.

  In the present embodiment, the detection result of the pressure sensor 23 when the abnormality occurs in the gaseous fuel injection valve 8 and the detection result of the pressure sensor 23 when the abnormality occurs in the gate valve 22 in the period Th. Even in the case of approximation, by referring to the detection result of the in-cylinder sensor 16, it is possible to determine which of the gaseous fuel injection valve 8 and the gate valve 22 is abnormal.

  In the present embodiment, for example, a temperature sensor capable of detecting the temperature of gas (exhaust gas) discharged from the combustion chamber 7 via the exhaust port 12 is provided, and the detection result of the temperature sensor and the detection of the pressure sensor 23 are provided. Based on the result, it may be determined which of the gaseous fuel injection valve 8 and the gate valve 22 is abnormal. Even when the detection result of the pressure sensor 23 when the abnormality occurs in the gaseous fuel injection valve 8 and the detection result of the pressure sensor 23 when the abnormality occurs in the gate valve 22 in the period Th, the temperature sensor By referring to the detection result, it can be determined which of the gaseous fuel injection valve 8 and the gate valve 22 is abnormal.

  The temperature of the exhaust gas discharged from the exhaust port 12 varies depending on the type of abnormality in the combustion chamber 7. Therefore, when the detection result of the pressure sensor 23 when an abnormality occurs in the gaseous fuel injection valve 8 and the detection result of the pressure sensor 23 when an abnormality occurs in the gate valve 22, the exhaust gas of the temperature sensor is approximated. Based on the temperature detection result, it can be determined which of the gaseous fuel injection valve 8 and the gate valve 22 is abnormal. By storing the relationship between the type of abnormality in the combustion chamber 7 and the temperature of the exhaust gas corresponding to the type of abnormality in the storage device, the control device 10 can detect the detection result of the temperature sensor and the information stored in the storage device. Based on the above, it can be determined which of the gaseous fuel injection valve 8 and the gate valve 22 is abnormal.

Second Embodiment
A second embodiment will be described. In the following embodiments, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  In the present embodiment, an example in which an abnormality of the gaseous fuel injection valve 8 is detected based on the detection result of the pressure sensor 23 in the fuel oil only mode will be described. In the fuel oil dedicated mode, the gaseous fuel PG is not supplied from the gaseous fuel supply source, and the control device 10 outputs a command signal to close the gaseous fuel injection valve 8. When the gaseous fuel injection valve 8 operates normally in the fuel oil dedicated mode, the gaseous fuel injection valve 8 is closed and the gaseous fuel PG is not injected from the gaseous fuel injection valve 8.

  Even if the control device 10 outputs a command signal for closing the gaseous fuel injection valve 8, an abnormality (opening abnormality) occurs in the gaseous fuel injection valve 8, based on the detection result of the pressure sensor 23, The abnormality of the gaseous fuel injection valve 8 can be detected.

  FIG. 12 is a diagram showing the relationship between the crank angle and the pressure of the supply passage 21 (the pressure at the inlet of the gaseous fuel injection valve 8) when the gaseous fuel injection valve 8 is normal and abnormal in the fuel oil dedicated mode. It is. In FIG. 12, the horizontal axis represents the crank angle, and the vertical axis represents the pressure in the supply flow path 21 between the gaseous fuel injection valve 8 and the gate valve 22 (pressure at the inlet of the gaseous fuel injection valve 8).

  When the gaseous fuel injection valve 8 is normal in the fuel oil dedicated mode, the output of the pressure sensor 23 is constant. On the other hand, when the gaseous fuel injection valve 8 is abnormal (when opened) in the fuel oil dedicated mode, the high-temperature and high-pressure gas in the combustion chamber 7 flows from the gaseous fuel injection valve 8 into the supply passage 21. Thereby, the pressure of the supply flow path 21 rises. The pressure in the supply channel 21 is detected by the pressure sensor 23. Therefore, the control device 10 can detect whether an abnormality has occurred in the gaseous fuel injection valve 8 in the fuel oil dedicated mode based on the detection result of the pressure sensor 23.

  As described above, according to the present embodiment, an abnormality of the gaseous fuel injection valve 8 can be detected even in the fuel oil only mode in which the gaseous fuel injection valve 8 is not used.

<Third Embodiment>
A third embodiment will be described. In the following embodiments, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  FIG. 13 is a schematic diagram illustrating an example of a gaseous fuel supply system 15 according to the present embodiment. As shown in FIG. 13, the gaseous fuel supply system 15 includes a gaseous fuel injection valve 8 that injects gaseous fuel PG into the combustion chamber 7, and a pre-injection valve 30. The pre-injection valve 30 is controlled by the control device 10. The pre-injection valve 30 injects gaseous fuel PG into the combustion chamber 7.

  The pre-injection valve 30 injects the gaseous fuel PG into the combustion chamber 7 before the gaseous fuel PG is injected from the gaseous fuel injection valve 8. In the present embodiment, a gaseous mixture of air and gaseous fuel PG is first generated in the combustion chamber 7 by the gaseous fuel PG injected from the pre-injection valve 30 and then further from the gaseous fuel injection valve 8 to the gaseous fuel PG. Is injected, combustion is performed in the combustion chamber 7.

  FIG. 14 is a diagram showing the relationship between the crank angle in the partial premixed combustion mode in which the partial premixed combustion is performed and the pressure of the supply flow path 21 (pressure at the inlet of the gaseous fuel injection valve 8). In FIG. 14, the horizontal axis is the crank angle, and the vertical axis is the pressure in the supply passage 21 between the gaseous fuel injection valve 8 and the gate valve 22 (pressure at the inlet of the gaseous fuel injection valve 8). FIG. 14 shows the relationship between the crank angle and the pressure in the supply flow path 21 when the pre-injection valve 30 is normal and abnormal.

  In the partial premixed combustion mode, the gaseous fuel PG is injected from the pre-injection valve 30 before the gaseous fuel PG is injected from the gaseous fuel injection valve 8. The operations of the gaseous fuel injection valve 8 and the gate valve 22 when the gaseous fuel PG is injected from the gaseous fuel injection valve 8 are the same as in the above-described embodiment. That is, the control device 10 opens the gate valve 22 when the crank angle is A1 degrees, opens the gaseous fuel injection valve 8 when the crank angle is A2 degrees, and opens the gaseous fuel injection valve 8 when the crank angle is A3 degrees. When the crank angle is A4 degrees, a command signal is output so as to close the gate valve 22.

  The sequence of opening and closing the gate valve 22 and the pre-injection valve 30 when injecting the gaseous fuel PG from the pre-injection valve 30 is the same as that for injecting the gaseous fuel PG from the gaseous fuel injection valve 8. This is the same as the open / close sequence. That is, when the gaseous fuel PG is injected from the pre-injection valve 30, the control device 10 opens the gate valve 22 when the crank angle is A1p degrees, and opens the pre-injection valve 30 when the crank angle is A2p degrees. When the angle is A3p degrees, the pre-injection valve 30 is closed, and when the crank angle is A4p degrees, the pre-injection valve 30 is closed.

  The control device 10 closes the pre-injection valve 30 that injected the gaseous fuel PG at the crank angle A3p and then closes the gate valve 22 at the crank angle A4p, and then the gaseous fuel PG is injected from the gaseous fuel injection valve 8. Thus, the command signal is output so that the gate valve 22 is opened at the crank angle A1.

  With reference to FIG. 14, an abnormality (open abnormality) in which the pre-injection valve 30 is open even though the control device 10 outputs a command signal for closing the pre-injection valve 30 will be described.

  Even if the command signal for closing the pre-injection valve 30 is output from the control device 10 at the crank angle A3p, the gate valve 22 is closed at the crank angle A4p without the pre-injection valve 30 being closed. With the valve 22 closed, the gaseous fuel PG is injected from the pre-injection valve 30 into the combustion chamber 7. As a result, as shown in FIG. 14, the pressure in the supply flow path 21 decreases from the time of the crank angle A3p. As described above, when the pre-injection valve 30 is abnormal (open abnormality) and when the pre-injection valve 30 is normal, the command signal for closing the pre-injection valve 30 is output at the crank angle A3p, and then the gate valve 22 is operated at the crank angle A1. The pressure in the supply flow path 21 in the period Tj until the command signal for opening is output is different. That is, when the pre-injection valve 30 is normal, the pressure of the supply flow path 21 in the period Tj is the pressure P2 as shown by the solid line in FIG. 14, and when the pre-injection valve 30 is abnormally open, the period Tj The pressure in the supply flow path 21 in FIG. 14 is lower than the pressure P2, as indicated by the dotted line in FIG. Therefore, the control device 10 can detect whether or not the pre-injection valve 30 is abnormal based on the detection result of the pressure sensor 23 in the period Tj.

  Next, an abnormality (closing abnormality) in which the pre-injection valve 30 is closed even though the control device 10 has output a command signal for opening the pre-injection valve 30 will be described. FIG. 15 is a diagram showing the relationship between the crank angle and the pressure in the supply flow path 21 (pressure at the inlet of the gaseous fuel injection valve 8) when the pre-injection valve 30 is abnormally closed.

  When the crank angle is A2p, a command signal for opening the pre-injection valve 30 is output from the controller 10, but if the pre-injection valve 30 is not opened, the pre-injection valve 30 is closed and the gate valve 22 is open. In this state, the gaseous fuel PG having the pressure P <b> 1 is supplied to the supply channel 21. Thereby, as shown in FIG. 15, the pressure of the supply flow path 21 in the period Tj becomes the pressure P1. Thus, the pressure of the supply flow path 21 in the period Tj differs depending on whether the pre-injection valve 30 is abnormal (closed abnormality) or normal. That is, when the pre-injection valve 30 is normal, the pressure in the supply flow path 21 in the period Tj is the pressure P2, as shown by the solid line in FIG. 15, and when the pre-injection valve 30 is abnormally closed, the period Tj As shown by the dotted line in FIG. 15, the pressure in the supply flow path 21 is a pressure P1 higher than the pressure P2. Therefore, whether or not the pre-injection valve 30 is abnormal can be detected based on the detection result of the pressure sensor 23 in the period Tj.

  As described above, according to the present embodiment, when the gaseous fuel supply system 15 includes the pre-injection valve 30, the detection of the pressure sensor 23 in the period Tj from when the pre-injection valve 30 is closed until the gate valve 22 is opened. Abnormality of the pre-injection valve 30 can be detected based on the result.

DESCRIPTION OF SYMBOLS 1 Dual fuel engine 7 Combustion chamber 8 Gas fuel injection valve 15 Gas fuel supply system 16 In-cylinder sensor 21 Supply flow path 22 Gate valve 23 Pressure sensor 30 Pre-injection valve PG Gas fuel

Claims (8)

A gaseous fuel supply system for supplying gaseous fuel to a combustion chamber of an engine,
An injection valve for injecting the gaseous fuel into the combustion chamber;
A gaseous fuel supply source for supplying the gaseous fuel at a first pressure;
A supply flow path through which the gaseous fuel supplied from the gaseous fuel supply source to the injection valve flows;
A gate valve capable of opening and closing the supply flow path;
A pressure sensor for detecting the pressure of the supply flow path between the injection valve and the gate valve;
A control device for outputting a command signal for opening and closing the injection valve and the gate valve,
When the crank angle becomes a first angle at which the piston of the engine is located near top dead center based on a detection result of a detection device that detects a crank angle of the crankshaft of the engine, A command signal for opening the gate valve is output, and a command signal for opening the injection valve is output when the crank angle reaches the second angle, and the crank angle becomes a third angle larger than the second angle. A command signal for closing the injection valve is sometimes output, and when the crank angle becomes a fourth angle larger than the third angle, the pressure of the supply passage is set to a second pressure lower than the first pressure. In order to output a command signal to close the gate valve,
Based on the detection result of the pressure sensor and the detection result of the detection device for detecting the crank angle of the crankshaft of the engine,
A second period from when the crank angle reaches the second angle to the third angle, a third period from when the crank angle reaches the fourth angle, and the third angle The detection result of the pressure sensor in the fourth period of the fourth period including the time point when the piston after the period is located near the bottom dead center is when the injection valve and the gate valve are operating normally When the pressure of the supply flow path is higher than that, the abnormal opening of the gate valve is detected.
Gaseous fuel supply system. A gaseous fuel supply system for supplying gaseous fuel to a combustion chamber of an engine,
An injection valve for injecting the gaseous fuel into the combustion chamber;
A gaseous fuel supply source for supplying the gaseous fuel at a first pressure;
A supply flow path through which the gaseous fuel supplied from the gaseous fuel supply source to the injection valve flows;
A gate valve capable of opening and closing the supply flow path;
A pressure sensor for detecting the pressure of the supply flow path between the injection valve and the gate valve;
A control device for outputting a command signal for opening and closing the injection valve and the gate valve,
When the crank angle becomes a first angle at which the piston of the engine is located near top dead center based on a detection result of a detection device that detects a crank angle of the crankshaft of the engine, A command signal for opening the gate valve is output, and a command signal for opening the injection valve is output when the crank angle reaches the second angle, and the crank angle becomes a third angle larger than the second angle. A command signal for closing the injection valve is sometimes output, and when the crank angle becomes a fourth angle larger than the third angle, the pressure of the supply passage is set to a second pressure lower than the first pressure. In order to output a command signal to close the gate valve,
Based on the detection result of the pressure sensor and the detection result of the detection device for detecting the crank angle of the crankshaft of the engine,
A second period from when the crank angle reaches the second angle to the third angle, a third period from when the crank angle reaches the fourth angle, and the third angle Among the fourth period including the time point at which the piston after the period is located near the bottom dead center , the detection result of the pressure sensor in the second period, the third period, and the fourth period is the injection valve and Detecting a closing abnormality of the gate valve when lower than the pressure of the supply flow path when the gate valve is operating normally;
Gaseous fuel supply system. A gaseous fuel supply system for supplying gaseous fuel to a combustion chamber of an engine,
An injection valve for injecting the gaseous fuel into the combustion chamber;
A gaseous fuel supply source for supplying the gaseous fuel at a first pressure;
A supply flow path through which the gaseous fuel supplied from the gaseous fuel supply source to the injection valve flows;
A gate valve capable of opening and closing the supply flow path;
A pressure sensor for detecting the pressure of the supply flow path between the injection valve and the gate valve;
A control device for outputting a command signal for opening and closing the injection valve and the gate valve,
When the crank angle becomes a first angle at which the piston of the engine is located near top dead center based on a detection result of a detection device that detects a crank angle of the crankshaft of the engine, A command signal for opening the gate valve is output, and a command signal for opening the injection valve is output when the crank angle reaches the second angle, and the crank angle becomes a third angle larger than the second angle. A command signal for closing the injection valve is sometimes output, and when the crank angle becomes a fourth angle larger than the third angle, the pressure of the supply passage is set to a second pressure lower than the first pressure. In order to output a command signal to close the gate valve,
Based on the detection result of the pressure sensor and the detection result of the detection device for detecting the crank angle of the crankshaft of the engine,
A second period from when the crank angle reaches the second angle to the third angle, a third period from when the crank angle reaches the fourth angle, and the third angle Among the fourth period including the time point when the piston after the period is located near the bottom dead center , the detection results of the pressure sensor in the third period and the fourth period indicate that the injection valve and the gate valve are normal. Detecting an opening abnormality of the injection valve when lower than the pressure of the supply flow path when operating ;
Gaseous fuel supply system. A gaseous fuel supply system for supplying gaseous fuel to a combustion chamber of an engine,
An injection valve for injecting the gaseous fuel into the combustion chamber;
A gaseous fuel supply source for supplying the gaseous fuel at a first pressure;
A supply flow path through which the gaseous fuel supplied from the gaseous fuel supply source to the injection valve flows;
A gate valve capable of opening and closing the supply flow path;
A pressure sensor for detecting the pressure of the supply flow path between the injection valve and the gate valve;
A control device for outputting a command signal for opening and closing the injection valve and the gate valve,
When the crank angle becomes a first angle at which the piston of the engine is located near top dead center based on a detection result of a detection device that detects a crank angle of the crankshaft of the engine, A command signal for opening the gate valve is output, and a command signal for opening the injection valve is output when the crank angle reaches the second angle, and the crank angle becomes a third angle larger than the second angle. A command signal for closing the injection valve is sometimes output, and when the crank angle becomes a fourth angle larger than the third angle, the pressure of the supply passage is set to a second pressure lower than the first pressure. In order to output a command signal to close the gate valve,
Based on the detection result of the pressure sensor and the detection result of the detection device for detecting the crank angle of the crankshaft of the engine,
A second period from when the crank angle reaches the second angle to the third angle, a third period from when the crank angle reaches the fourth angle, and the third angle Among the fourth period including the time point at which the piston after the period is located near the bottom dead center , the detection result of the pressure sensor in the second period, the third period, and the fourth period is the injection valve and Detecting a closing abnormality of the injection valve when higher than the pressure of the supply flow path when the gate valve is operating normally;
Gaseous fuel supply system. A gaseous fuel supply system for supplying gaseous fuel to a combustion chamber of an engine,
An injection valve for injecting the gaseous fuel into the combustion chamber;
A gaseous fuel supply source for supplying the gaseous fuel at a first pressure;
A supply flow path through which the gaseous fuel supplied from the gaseous fuel supply source to the injection valve flows;
A gate valve capable of opening and closing the supply flow path;
A pressure sensor for detecting the pressure of the supply flow path between the injection valve and the gate valve;
A control device for outputting a command signal for opening and closing the injection valve and the gate valve,
When the crank angle becomes a first angle at which the piston of the engine is located near top dead center based on a detection result of a detection device that detects a crank angle of the crankshaft of the engine, A command signal for opening the gate valve is output, and a command signal for opening the injection valve is output when the crank angle reaches the second angle, and the crank angle becomes a third angle larger than the second angle. A command signal for closing the injection valve is sometimes output, and when the crank angle becomes a fourth angle larger than the third angle, the pressure of the supply passage is set to a second pressure lower than the first pressure. In order to output a command signal to close the gate valve,
Based on the detection result of the pressure sensor and the detection result of the detection device for detecting the crank angle of the crankshaft of the engine,
A second period from when the crank angle reaches the second angle to the third angle, a third period from when the crank angle reaches the fourth angle, and the third angle The detection result of the pressure sensor in the fourth period of the fourth period including the time point when the piston after the period is located near the bottom dead center is when the injection valve and the gate valve are operating normally When the pressure of the supply flow path is higher, the opening abnormality of the gate valve is detected,
When the detection result of the pressure sensor in the second period, the third period, and the fourth period is higher than the pressure of the supply flow path when the injection valve and the gate valve are operating normally, Detecting an abnormal closing of the injection valve;
Based on the detection result of the pressure sensor and the detection result of an in-cylinder sensor that detects the pressure in the combustion chamber, it is determined whether an abnormality in the opening of the gate valve or an abnormality in the closing of the injection valve has occurred.
Gaseous fuel supply system. A gaseous fuel supply system for supplying gaseous fuel to a combustion chamber of an engine,
An injection valve for injecting the gaseous fuel into the combustion chamber;
A gaseous fuel supply source for supplying the gaseous fuel at a first pressure;
A supply flow path through which the gaseous fuel supplied from the gaseous fuel supply source to the injection valve flows;
A gate valve capable of opening and closing the supply flow path;
A pressure sensor for detecting the pressure of the supply flow path between the injection valve and the gate valve;
A pre-injection valve that injects gaseous fuel into the combustion chamber before the injection of the gaseous fuel from the injection valve;
A control device for outputting a command signal for opening and closing the injection valve and the gate valve,
When the crank angle becomes a first angle at which the piston of the engine is located near top dead center based on a detection result of a detection device that detects a crank angle of the crankshaft of the engine, A command signal for opening the gate valve is output, and a command signal for opening the injection valve is output when the crank angle reaches the second angle, and the crank angle becomes a third angle larger than the second angle. A command signal for closing the injection valve is sometimes output, and when the crank angle becomes a fourth angle larger than the third angle, the pressure of the supply passage is set to a second pressure lower than the first pressure. In order to output a command signal to close the gate valve,
The control device closes the pre-injection valve that injected the gaseous fuel and then closes the gate valve, and then issues a command signal to open the gate valve for the injection of the gaseous fuel from the injection valve. Output of the pre-injection valve based on the detection result of the pressure sensor in a period from when the command signal for closing the pre-injection valve is output until the instruction signal for opening the gate valve is output. An abnormality is detected , and based on the detection result of the detection device, a command signal for opening the gate valve is output when the crank angle reaches the first pre-angle, and the crank angle is greater than the first pre-angle. A command signal for opening the pre-injection valve is output when the second pre-angle is large, and the pre-injection is performed when the crank angle is a third pre-angle larger than the second pre-angle. A command signal to close the gate valve in order to set the pressure of the supply flow path to the second pressure when the crank angle becomes a fourth pre-angle larger than the third pre-angle. Output a signal, and after closing the gate valve, output a command signal to open the gate valve for injection of the gaseous fuel from the injection valve,
Based on the detection result of the pressure sensor in the period from the output of the command signal for closing the pre-injection valve to the output of the command signal for opening the gate valve,
When the detection result in the period is a pressure lower than the second pressure, an opening abnormality of the pre-injection valve is detected,
When the detection result in the period is the first pressure, an abnormal closing of the pre-injection valve is detected.
Gas fuel system. A gaseous fuel supply system that supplies gaseous fuel to a combustion chamber of an engine that is a dual fuel engine,
An injection valve for injecting the gaseous fuel into the combustion chamber;
A gaseous fuel supply source for supplying the gaseous fuel at a first pressure;
A supply flow path through which the gaseous fuel supplied from the gaseous fuel supply source to the injection valve flows;
A gate valve capable of opening and closing the supply flow path;
A pressure sensor for detecting the pressure of the supply flow path between the injection valve and the gate valve;
A control device for outputting a command signal for opening and closing the injection valve and the gate valve,
In the dual fuel engine, a liquid fuel is supplied from the liquid fuel injection valve to the combustion chamber and the gaseous fuel is supplied, and a liquid fuel is supplied from the liquid fuel injection valve to the combustion chamber and the gaseous fuel is supplied to the combustion chamber. Can operate in each mode with fuel oil only mode not supplied,
When the crank angle becomes a first angle at which the piston of the engine is located near top dead center based on a detection result of a detection device that detects a crank angle of the crankshaft of the engine, A command signal for opening the gate valve is output, and a command signal for opening the injection valve is output when the crank angle reaches the second angle, and the crank angle becomes a third angle larger than the second angle. A command signal for closing the injection valve is sometimes output, and when the crank angle becomes a fourth angle larger than the third angle, the pressure of the supply passage is set to a second pressure lower than the first pressure. In order to output a command signal to close the gate valve,
Based on a detection result of the pressure sensor in the two-fuel mode and a detection result of a detection device that detects a crank angle of the crankshaft of the engine, a closing abnormality of the injection valve is detected,
Based on the detection result of the pressure sensor in the fuel oil-only mode, when the pressure of the supply flow path increases, an abnormal opening of the injection valve is detected.
Gaseous fuel supply system. An abnormality detection method for a gaseous fuel supply system for supplying gaseous fuel to a combustion chamber of an engine,
The gaseous fuel supply system includes:
An injection valve for injecting the gaseous fuel into the combustion chamber;
A gaseous fuel supply source for supplying the gaseous fuel at a first pressure;
A supply flow path through which the gaseous fuel supplied from the gaseous fuel supply source to the injection valve flows;
A gate valve capable of opening and closing the supply flow path;
A pressure sensor for detecting the pressure of the supply flow path between the injection valve and the gate valve,
Based on the detection result of the detection device for detecting the crank angle of the crankshaft of the engine, a command to open the gate valve when the crank angle becomes the first angle at which the piston of the engine is located near top dead center Outputting a signal;
Outputting a command signal for opening the injection valve when the crank angle becomes the second angle;
Outputting a command signal for closing the injection valve when the crank angle becomes a third angle larger than the second angle;
When the crank angle becomes a fourth angle larger than the third angle, a command signal for closing the gate valve is output in order to set the pressure of the supply flow path to a second pressure lower than the first pressure. Process,
Based on the detection result of the pressure sensor and the detection result of the detection device for detecting the crank angle of the crankshaft of the engine, a first time from when the crank angle becomes the second angle until the third angle is reached. 2 periods, a third period from when the third angle is reached until the fourth angle is reached, and a fourth period including a time point at which the piston after the third period is located near the bottom dead center Detecting an abnormal opening of the gate valve when the detection result of the pressure sensor in the fourth period is higher than the pressure of the supply flow path when the injection valve and the gate valve are operating normally. When,
When the detection result of the pressure sensor in the second period, the third period, and the fourth period is lower than the pressure of the supply flow path when the injection valve and the gate valve are operating normally, Detecting a closing abnormality of the gate valve;
When the detection result of the pressure sensor in the third period and the fourth period is lower than the pressure in the supply flow path when the injection valve and the gate valve are operating normally, the abnormal opening of the injection valve Detecting
When the detection result of the pressure sensor in the second period, the third period, and the fourth period is higher than the pressure of the supply flow path when the injection valve and the gate valve are operating normally, Detecting an abnormal closing of the injection valve;
An abnormality detection method for a gaseous fuel supply system including:

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