Engine diagnostic device and engine power-generation system

Abstract

To provide an engine diagnostic device capable of promptly diagnosing engine abnormalities.SOLUTION: An engine diagnostic device comprises: a kinetic-energy change-rate calculation unit for calculating, on the basis of an actual rotation speed of an engine, a value relating to a time change rate of total kinetic energy obtained by summing the kinetic energy of an engine and a device driven by the engine; a total work-amount calculation unit configured to calculate a total work amount, which is the sum of a value relating to the time change rate of the total kinetic energy calculated by the kinetic-energy change-rate calculation unit and a value relating to an actual output of the engine; a theoretical work-amount calculation unit configured to calculate a theoretical work amount, which is a theoretical value of the work amount of the engine on the basis of a fuel flow-rate command-value; and an engine diagnosis unit configured to diagnose an abnormality of the engine on the basis of the total work amount calculated by the total work-amount calculation unit and the theoretical work-amount calculated by the theoretical work-amount calculation unit.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to an engine diagnostic device and an engine power generation system. [Background technology]

[0002] Patent Document 1 discloses that in a gas engine, the exhaust temperature is detected by an exhaust temperature sensor provided for each cylinder, and if the exhaust temperature drops, it is diagnosed that a misfire has occurred. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-121257 Summary of the Invention [Problem to be solved by the invention]

[0004] When diagnosing engine abnormalities based on the engine exhaust temperature as described in Patent Document 1, it tends to take some time after an engine abnormality occurs for the engine exhaust temperature to change to a level that allows the abnormality to be detected, making it difficult to diagnose the engine abnormality quickly.

[0005] In view of the above circumstances, an object of at least one embodiment of the present disclosure is to provide an engine diagnostic device and an engine power generation system capable of quickly diagnosing an abnormality in an engine. [Means for solving the problem]

[0006] In order to achieve the above object, an engine diagnosis device according to at least one embodiment of the present disclosure includes: a data acquisition unit configured to acquire an actual engine speed, a value related to an actual output of the engine, and a fuel flow command value for controlling a fuel flow rate of the engine; a kinetic energy change rate calculation unit that calculates a value relating to a time change rate of a total kinetic energy, which is a sum of kinetic energies of the engine and a device driven by the engine, based on the actual rotation speed of the engine acquired by the data acquisition unit; a total work amount calculation unit configured to calculate a total work amount by summing a value relating to a time rate of change of the total kinetic energy calculated by the kinetic energy change rate calculation unit and a value relating to an actual output of the engine acquired by the data acquisition unit; a theoretical workload calculation unit configured to calculate a theoretical workload, which is a theoretical value of the workload of the engine, based on the fuel flow rate command value; an engine diagnosis unit configured to diagnose an abnormality of the engine based on the total workload calculated by the total workload calculation unit and the theoretical workload calculated by the theoretical workload calculation unit; Equipped with.

[0007] In order to achieve the above object, an engine power generation system according to at least one embodiment of the present disclosure includes: The engine diagnostic device includes an engine, a generator connected to the engine, and the engine diagnostic device. Effect of the Invention

[0008] According to at least one embodiment of the present disclosure, an engine diagnostic device and an engine power generation system capable of quickly diagnosing an abnormality in an engine are provided. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing a schematic configuration of an engine power generation system 2 according to an embodiment of the present disclosure. [Diagram 2] 2 is a diagram showing an example of a hardware configuration of an engine controller 8 of the engine power generation system 2. FIG. [Diagram 3] 2 is a block diagram showing an example of a functional configuration of an engine controller 8. FIG. [Figure 4]FIG. 4 is a diagram showing a part of an example of an abnormality diagnosis flow for the gas engine 4 by the engine controller 8. [Diagram 5] 5 is a diagram showing a continuation of the example of the abnormality diagnosis flow shown in FIG. 4. [Figure 6] 11 is a diagram showing an example of changes over time in engine speed Ne, generator output P, ​​threshold value Th1, QE, and fuel flow rate command value Qgas. FIG. [Figure 7] FIG. 1 is a diagram showing an example of changes over time in theoretical workload Q and total workload E. [Figure 8] FIG. 11 is a diagram showing an example of changes over time in the engine speed Ne, the generator output P, ​​the fuel leakage equivalent amount, the threshold value Th2, EQ, and the fuel flow rate command value Qgas. [Figure 9] FIG. 1 is a diagram showing an example of changes over time in total workload E and theoretical workload Q. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the invention. For example, expressions expressing relative or absolute configuration, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only express such a configuration strictly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance of the theoretical degree of engine work that can obtain the same function. For example, expressions indicating that things are in an equal state, such as "identical," "equal," and "homogeneous," not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions describing shapes such as a rectangular shape or a cylindrical shape do not only refer to rectangular shapes, cylindrical shapes, etc. in the strict geometric sense, but also refer to shapes that include uneven portions, chamfered portions, etc., to the extent that the same effect is obtained. On the other hand, the expressions "comprise," "include," "have," "includes," or "have" of one element are not exclusive expressions excluding the presence of other elements.

[0011] Fig. 1 is a schematic diagram showing a schematic configuration of an engine power generation system 2 according to an embodiment of the present disclosure. As shown in Fig. 1, the engine power generation system 2 includes a gas engine 4 (hereinafter simply referred to as "engine 4"), a generator 6, and an engine controller 8 serving as an engine diagnostic device.

[0012] The engine 4 includes a plurality of cylinders 10, a piston 12 provided for each cylinder 10 and reciprocating along the axis of the cylinder 10 within the cylinder 10, a crankshaft 14 for converting the reciprocating motion of the piston 12 into rotational motion, a combustion chamber 16 formed for each cylinder 10 between the inner surface of the cylinder 10 and the upper surface of the piston 12, an intake passage 18 provided for each cylinder 10 and connected to the combustion chamber 16, and an exhaust passage 20 provided for each cylinder 10 and connected to the combustion chamber 16. Since the configuration of each cylinder 10 in the engine 4 is the same, FIG. 1 shows only the configuration related to one of the plurality of cylinders 10, and the configurations related to the other cylinders 10 are omitted for convenience.

[0013] The engine 4 also includes a fuel supply passage 22 that supplies fuel gas (hereinafter simply referred to as "fuel") to the intake passage 18, a fuel supply valve 24 provided in the fuel supply passage 22 for each cylinder 10, and a shutoff valve 26 that can stop the supply of fuel to the entire engine 4. In the illustrated exemplary embodiment, the fuel supply passage 22 includes a main pipe 28 and a plurality of branch pipes 30 branched from the main pipe 28, and each of the plurality of branch pipes 30 is provided for each cylinder 10 and configured to supply fuel to the intake passage 18 to the corresponding cylinder 10. Each fuel supply valve 24 is provided in each branch pipe 30 of the fuel supply passage 22, and the shutoff valve 26 is provided in the main pipe 28.

[0014] In addition, the engine 4 is equipped with a rotation sensor 32 that measures the actual rotation speed of the engine 4 (hereinafter referred to as "engine rotation speed"), and a power meter 34 that measures the output of the generator 6 (hereinafter referred to as "generator output").

[0015] The engine controller 8 is configured to be able to control each of the fuel supply valves 24 and the shutoff valve 26. During operation of the engine 4, the engine controller 8 controls the shutoff valve 26 to an open state, and opens and closes the fuel supply valve 24 for each cylinder 10 for each combustion cycle, thereby causing fuel to be injected from the fuel supply valve 24 into the air flowing through the intake passage 18. The engine controller 8 is configured to control the fuel supply valve 24 corresponding to each cylinder 10 based on a command value of the fuel flow rate of the engine 4 (hereinafter simply referred to as a "fuel flow command value"). The engine controller 8 generates a fuel flow command value based on the deviation between the target rotation speed of the engine 4 and the engine rotation speed measured by the rotation sensor 32 so as to bring the engine rotation speed closer to the target rotation speed. When the engine rotation speed measured by the rotation sensor 32 is smaller than the target rotation speed, the engine controller 8 increases the fuel flow command value, and when the engine rotation speed measured by the rotation sensor 32 is larger than the target rotation speed, the engine controller 8 decreases the fuel flow command value.

[0016] In the engine 4, fuel is injected from a fuel supply valve 24 into air flowing through an intake passage 18, and a mixture of the air and fuel is supplied from the intake passage 18 to the combustion chamber 16 through an intake valve (not shown). The mixture supplied from the intake passage 18 to the combustion chamber 16 is ignited by an ignition device (not shown) and combusted in the combustion chamber 16, and the combustion exhaust gas is discharged from an exhaust passage 20 through an exhaust valve (not shown). The reciprocating motion of the piston 12 is converted into the rotational motion of the crankshaft 14, and the rotational energy of the crankshaft 14 is transmitted to a generator 6 connected to the crankshaft 14, causing the generator 6 to generate electricity.

[0017] Fig. 2 is a diagram showing an example of a hardware configuration of the engine controller 8. Fig. 3 is a block diagram showing an example of a functional configuration of the engine controller 8. Fig. 4 is a diagram showing a part of an example of an abnormality diagnosis flow of the gas engine 4 by the engine controller 8. Fig. 5 is a diagram showing a continuation of the example of the abnormality diagnosis flow shown in Fig. 4.

[0018] 2, the engine controller 8 includes, for example, a processor 72, a random access memory (RAM) 74, a read only memory (ROM) 76, a hard disk drive (HDD) 78, an input I / F 80, and an output I / F 82, and is configured using a computer in which these are connected to one another via a bus 84. The engine controller 8 is configured by the computer executing a program that realizes each function of the engine controller 8. The functions of each part in the engine controller 8 described below are realized, for example, by loading a program held in a ROM 76 into the RAM 74 and executing it with the processor 72, and by reading and writing data from and to the RAM 74 and the ROM 76. The hardware that constitutes the engine controller 8 may be provided in one location, or may be provided in a distributed manner in multiple locations.

[0019] 3, the engine controller 8 includes a data acquisition unit 40, a kinetic energy change rate calculation unit 41, a total work amount calculation unit 42, a theoretical work amount calculation unit 44, and an engine diagnosis unit 46. The following describes the control content of the engine controller 8 when the engine controller 8 controls the rotation speed of the engine 4 to be constant, that is, when the target rotation speed of the engine 4 is constant (for example, the rated rotation speed).

[0020] 4, in S101, the data acquiring unit 40 sequentially acquires the engine speed measured by the rotation sensor 32 from the rotation sensor 32. The data acquiring unit 40 also sequentially acquires the generator output measured by the power meter 34 from the power meter 34. The data acquiring unit 40 also sequentially acquires the above-mentioned fuel flow command value for controlling the fuel flow rate of the engine 4 (in this embodiment, the fuel flow command value generated by the engine controller 8 itself).

[0021] In S102, the kinetic energy change rate calculation unit 41 calculates the time change rate of the total kinetic energy, which is the sum of the kinetic energy of the engine 4 and the kinetic energy of the generator 6, based on the engine speed acquired by the data acquisition unit 40. Specifically, the kinetic energy change rate calculation unit 41 first calculates the total kinetic energy, which is the sum of the kinetic energy of the engine 4 and the kinetic energy of the generator 6, based on the following formula (1). TIFF2025070288000002.tif11170

[0022] Here, K is the total kinetic energy obtained by summing the kinetic energy of the engine 4 and the kinetic energy of the generator 6, i.e., the total kinetic energy obtained by summing the kinetic energy of the rotating parts of the engine 4 and the kinetic energy of the rotating parts of the generator 6 (in other words, the total kinetic energy obtained by summing the kinetic energy of the crankshaft 14 of the engine 4 and the kinetic energy of all the mechanical parts interlocked with the crankshaft 14). Ie is the moment of inertia of the assembly of the rotating parts of the engine 4 and the rotating parts of the generator 6, i.e., the moment of inertia of the assembly of the crankshaft 14 of the engine 4 and all the mechanical parts interlocked with the crankshaft 14. Ne is the engine speed acquired by the data acquisition unit 40, i.e., the engine speed measured by the rotation sensor 32.

[0023] Then, the kinetic energy change rate calculation unit 41 calculates dK / dt, which is the time rate of change of the total kinetic energy K, by differentiating the total kinetic energy K with respect to time.

[0024] Next, in S103, the total work amount calculation unit 42 calculates the total work amount by summing the generator output acquired by the data acquisition unit 40 and the time rate of change of the total kinetic energy calculated by the kinetic energy change rate calculation unit 41, based on the following equation (2). TIFF2025070288000003.tif9170

[0025] Here, P is the generator output acquired by the data acquisition unit 40, and E is the total work amount.

[0026] In S104, the theoretical workload calculation unit 44 calculates a theoretical workload, which is a theoretical value of the workload of the engine 4, based on the fuel flow rate command value of the engine 4, using the following equation (3). TIFF2025070288000004.tif11170

[0027] Here, Qgas is the fuel flow rate command value, LHV is the lower heating value of the fuel, η is the thermal efficiency of the engine 4, and Q is the theoretical work amount of the engine 4 calculated based on the fuel flow rate command value.

[0028] In S105, the engine diagnosis unit 46 determines whether or not a difference value (=QE) obtained by subtracting the total workload E from the theoretical workload Q of the engine 4 is greater than a threshold value Th1. That is, the engine diagnosis unit 46 determines whether or not the theoretical workload Q and the total workload E satisfy the following formula (4). QE>Th1 (4)

[0029] If it is determined in S105 that the above formula (4) is satisfied, in S106, the engine diagnosis unit 46 determines whether or not the state in which the above difference value (=QE) is greater than the threshold value Th1 continues for a predetermined time or more. The predetermined time here is a time that is set in advance, and may be, for example, about 0.1 to 2 seconds.

[0030] In S106, if it is determined that the state in which the difference value (=QE) is greater than the threshold value Th1 has not continued for a predetermined period of time or longer, the process returns to S101.

[0031] If it is determined in S106 that the state in which the difference value (=QE) is greater than the threshold value Th1 continues for a predetermined time or longer, the engine diagnosis unit 46 diagnoses in S107 that a misfire has occurred in the engine 4. The occurrence of a misfire in S107 means that a misfire has occurred in at least one cylinder among the multiple cylinders 10 of the engine 4.

[0032] When the engine diagnosis unit 46 diagnoses that a misfire has occurred in the engine 4, in S108, the engine controller 8 stops the supply of fuel to the engine 4. In S108, the engine controller 8 may stop the supply of fuel to the engine 4 by, for example, closing the shutoff valve 26 in FIG.

[0033] If it is determined in S105 that the above formula (4) is not satisfied, the engine diagnosis unit 46 diagnoses that a misfire has not occurred in the engine 4, and the process proceeds to S109.

[0034] 5, in S109, the engine diagnosis unit 46 determines whether or not a difference value (=EQ) obtained by subtracting the theoretical workload Q from the total workload E of the engine 4 is greater than a threshold value Th2. That is, the engine diagnosis unit 46 determines whether or not the theoretical workload Q and the total workload E satisfy the following formula (5). EQ>Th2 (5) Here, the threshold value Th2 may be a value smaller than the threshold value Th1.

[0035] If it is determined in S109 that the above formula (5) is not satisfied, the engine diagnosis unit 46 diagnoses that no fuel leakage is occurring in the fuel supply valve 24 of the engine 4, and returns to S101. If it is determined in S109 that the above formula (5) is satisfied, the engine diagnosis unit 46 determines in S110 whether or not a state in which the above difference value (=EQ) is greater than the threshold value Th2 continues for a predetermined time or more. The predetermined time here is a time that is set in advance, and may be, for example, about 0.1 to 2 seconds.

[0036] If it is determined in S110 that the state in which the difference value (=EQ) is greater than the threshold value Th2 has not continued for a predetermined period of time or longer, the process returns to S109.

[0037] If it is determined in S110 that the state in which the difference value (=EQ) is greater than the threshold value Th2 continues for a predetermined time or longer, then in S111, the engine diagnosis unit 46 diagnoses that a fuel leak has occurred in the fuel supply valve 24 (see FIG. 1) of the engine 4. The occurrence of a fuel leak in S111 means that a fuel leak has occurred in at least one of the multiple fuel supply valves 24 provided corresponding to the multiple cylinders 10 of the engine 4.

[0038] When the engine diagnosis unit 46 diagnoses that a fuel leak has occurred in the fuel supply valve 24 of the engine 4, in S112 the engine controller 8 stops the supply of fuel to the engine 4. In S112, the engine controller 8 may stop the supply of fuel to the engine 4 by, for example, closing the shutoff valve 26 of FIG. 1.

[0039] According to the above embodiment, the engine diagnosis unit 46 diagnoses an abnormality in the engine 4 based on the total workload E calculated by the total workload calculation unit 42 and the theoretical workload Q calculated by the theoretical workload calculation unit 44. This makes it possible to diagnose (detect) the presence or absence of an abnormality, such as a misfire in the engine 4 or a gas leak from the fuel supply valve 24, more quickly than when an abnormality in the engine 4 is diagnosed based on the exhaust temperature of the engine 4.

[0040] For example, when a state in which a difference value (=QE) obtained by subtracting the total workload E calculated by the total workload calculation unit 42 from the theoretical workload Q calculated by the theoretical workload calculation unit 44 is greater than the threshold value Th1 continues for a predetermined time or more, the engine diagnosis unit 46 diagnoses that a misfire has occurred in the engine 4, thereby making it possible to diagnose (detect) the occurrence of a misfire in the engine 4 more quickly than when the engine 4 is diagnosed based on the exhaust temperature of the engine 4. Furthermore, when the engine diagnosis unit 46 diagnoses that a misfire has occurred in the engine 4, the engine controller 8 stops the supply of fuel to the engine 4. As a result, when a misfire has occurred in the engine 4, it is possible to diagnose (detect) the misfire quickly and stop the supply of fuel to the engine 4 quickly. In other words, it is possible to shorten the time from the occurrence of a misfire to the stop of the supply of fuel to the engine 4. Therefore, it is possible to suppress the emission of unburned gas into the exhaust passage 20 (see Figure 1) of the engine 4 due to the misfire, and to suppress the occurrence of afterfire caused by unburned gas remaining in the exhaust passage 20 (rapid combustion caused by unburned gas remaining in the exhaust passage being ignited by high-temperature exhaust gas discharged from the combustion chamber 16 in the next combustion cycle).

[0041] Furthermore, when a state in which a difference value (=EQ) obtained by subtracting the theoretical workload Q calculated by the theoretical workload calculation unit 44 from the total workload E calculated by the total workload calculation unit 42 is greater than the threshold value Th2 continues for a predetermined time or more, the engine diagnosis unit 46 diagnoses that a fuel leak has occurred at the fuel supply valve 24 of the engine 4, thereby making it possible to diagnose (detect) a fuel leak at the fuel supply valve 24 of the engine 4 more quickly than when the engine 4 is diagnosed based on the exhaust temperature of the engine 4. Furthermore, when the engine diagnosis unit 46 diagnoses that a fuel leak has occurred at the fuel supply valve 24 of the engine 4, the engine controller 8 stops the supply of fuel to the engine 4. As a result, when a fuel leak has occurred at the fuel supply valve 24 of the engine 4, it is possible to diagnose (detect) the fuel leak quickly and stop the fuel supply to the engine 4 quickly. That is, it is possible to shorten the time from the occurrence of a fuel leak to the stop of the fuel supply to the engine 4. Therefore, it is possible to suppress the emission of unburned gas into the exhaust passage 20 (see Figure 1) of the engine 4 due to the fuel leak, and to suppress the occurrence of afterfires caused by unburned gas remaining in the exhaust passage 20 (rapid combustion caused by unburned gas remaining in the exhaust passage being ignited by high-temperature exhaust gas discharged from the combustion chamber 16 in the next combustion cycle).

[0042] FIG. 6 is a diagram showing the time-dependent changes in engine speed Ne, generator output P, ​​threshold value Th1, QE, and fuel flow command value Qgas. FIG. 7 is a diagram showing the time-dependent changes in theoretical workload Q and total workload E. FIG. 6 and FIG. 7 show the results of simulating the time-dependent changes in each parameter when one cylinder of engine 4 misfires during the period from time t1 to time t2 while engine 4 is operating at the rated speed. Note that FIG. 6 conveniently displays the time-dependent changes in multiple parameters in one diagram, and therefore the magnitude relationship between parameters of different dimensions in FIG. 6 should be ignored.

[0043] As shown in Fig. 6, when a misfire occurs in the engine 4 at time t1, the engine speed Ne and the generator output P start to decrease, so that the engine controller 8 increases the fuel flow command value Qgas to bring the engine speed Ne closer to the rated speed. Therefore, just after time t1, the theoretical workload Q starts to increase while the total workload E starts to decrease, as shown in Fig. 7. This causes QE to become larger than the threshold value Th1 as shown in Fig. 6, so that the engine diagnosis unit 46 can diagnose (detect) that a misfire has occurred in the engine 4 if the state in which QE is larger than the threshold value Th1 continues for a predetermined time or longer.

[0044] FIG. 8 is a diagram showing the time-dependent changes in engine speed Ne, generator output P, ​​fuel leakage equivalent amount from the fuel supply valve, threshold value Th2, EQ, and fuel flow command value Qgas. FIG. 9 is a diagram showing the time-dependent changes in total workload E and theoretical workload Q. FIG. 8 and FIG. 9 show the results of simulating the time-dependent changes in each parameter when fuel leakage occurs in the fuel supply valve 24 corresponding to one cylinder of the engine 4 during the period from time t3 to time t4 during the period when the engine 4 is operated at the rated speed. Note that, since FIG. 8 shows the time-dependent changes in multiple parameters in one diagram for the sake of convenience, the magnitude relationship between parameters of different dimensions in FIG. 8 should be ignored.

[0045] As shown in Fig. 8, when fuel leakage occurs at the fuel supply valve 24 of the engine 4 at time t3, the amount of fuel supplied to the combustion chamber 16 and the total work load E instantaneously increase, and the engine speed Ne starts to rise, so that the engine controller 8 reduces the fuel flow command value Qgas to bring the engine speed Ne closer to the rated speed. Therefore, as shown in Fig. 9, immediately after time t3, the theoretical work load Q starts to decrease, and the theoretical work load Q decreases until the engine speed Ne returns to the rated speed. As a result, EQ becomes larger than the threshold value Th2 as shown in Fig. 8, so that the engine diagnosis unit 46 can diagnose (detect) that fuel leakage has occurred at the fuel supply valve 24 of the engine 4 when the state in which EQ is larger than the threshold value Th2 continues for a predetermined time or more.

[0046] The present disclosure is not limited to the above-described embodiments, and includes modifications to the above-described embodiments and appropriate combinations of these modifications.

[0047] For example, if a bearing (not shown) of the engine 4 seizes, mechanical loss becomes excessive at the seized portion, and the total work amount E becomes smaller than the theoretical work amount Q. For this reason, the engine diagnosis unit 46 may diagnose that the bearing is seized when QE is larger than a predetermined threshold value. Also, if a fuel leak occurs in a portion between the fuel supply valve 24 and the combustion chamber 16 in the intake passage 18, the total work amount E becomes smaller than the theoretical work amount Q. For this reason, the engine diagnosis unit 46 may diagnose that a fuel leak occurs in a portion between the fuel supply valve 24 and the combustion chamber 16 in the intake passage 18 when QE is larger than a predetermined threshold value. In this way, the engine diagnosis unit 46 can diagnose various abnormalities of the engine 4 based on the theoretical work amount Q and the total work amount E.

[0048] In the above embodiment, the engine 4 is used as a power source for the generator 6, but the engine 4 may be used as a power source for a machine other than a generator. In this case, the data acquiring unit 40 may acquire a value related to another output instead of the generator output P as a value related to the actual output of the engine. Even in this case, the total work amount calculating unit 42 calculates the total work amount by summing the time rate of change dK / dt of the total kinetic energy and the value related to the actual output of the engine acquired by the data acquiring unit 40.

[0049] In the above-described embodiment, the engine controller 8 for controlling the fuel supply valve 24 and the like constitutes the engine diagnostic device, but the engine diagnostic device may be provided separately from the engine controller for controlling the fuel supply valve 24.

[0050] In addition, in the above-described embodiment, the engine diagnosis unit 46 diagnosed that a misfire has occurred in the engine 4 when a state in which the difference value obtained by subtracting the total workload E calculated by the total workload calculation unit 42 from the theoretical workload Q calculated by the theoretical workload calculation unit 44 is greater than the threshold value Th1 continues for a predetermined time or more, but the engine diagnosis unit 46 may diagnose that a misfire has occurred in the engine 4 when the difference value obtained by subtracting the total workload E calculated by the total workload calculation unit 42 from the theoretical workload Q calculated by the theoretical workload calculation unit 44 is greater than the threshold value Th1, without requiring that the state continue for a predetermined time or more.

[0051] In addition, engine diagnosis unit 46 diagnoses that a fuel leak is occurring at fuel supply valve 24 of engine 4 when a state in which the difference value obtained by subtracting the theoretical work amount Q calculated by theoretical work amount calculation unit 44 from the total work amount E calculated by total work amount calculation unit 42 is greater than threshold value Th2 continues for a predetermined time or more.However, engine diagnosis unit 46 may diagnose that a fuel leak is occurring at fuel supply valve 24 of engine 4 when the difference value obtained by subtracting the theoretical work amount Q calculated by theoretical work amount calculation unit 44 from the total work amount E calculated by total work amount calculation unit 42 is greater than threshold value Th2, without requiring that the state continue for a predetermined time or more.

[0052] Furthermore, if the engine controller 8 diagnoses that a misfire has occurred in the engine 4 in S107 above, and it is possible to identify by some means which cylinder 10 among the multiple cylinders 10 in which the misfire has occurred, then instead of closing the shutoff valve 26, the engine controller 8 may close only the fuel supply valve 24 corresponding to the cylinder 10 in which the misfire has occurred.

[0053] The contents described in each of the above embodiments can be understood, for example, as follows.

[0054] [1] An engine diagnostic device according to at least one embodiment of the present disclosure (e.g., the above-mentioned engine controller 8) a data acquisition unit (e.g., the above-mentioned data acquisition unit 40) configured to acquire an actual rotation speed (e.g., the above-mentioned engine rotation speed Ne) of an engine (e.g., the above-mentioned engine 4), a value related to an actual output of the engine (e.g., the above-mentioned generator output P), and a fuel flow command value for controlling a fuel flow rate of the engine (e.g., the above-mentioned fuel flow command value Qgas); a kinetic energy change rate calculation unit (for example, the above-mentioned kinetic energy change rate calculation unit 41) that calculates a value relating to a time change rate (for example, the above-mentioned dK / dt) of a total kinetic energy (for example, the above-mentioned total kinetic energy K) obtained by adding up the kinetic energies of the engine and a device driven by the engine (for example, the above-mentioned generator 6) based on the actual engine speed acquired by the data acquisition unit; a total work amount calculation unit (e.g., the above-mentioned total work amount calculation unit 42) configured to calculate a total work amount (e.g., the above-mentioned total work amount E) by summing a value related to the time rate of change of the total kinetic energy calculated by the kinetic energy change rate calculation unit and a value related to the actual output of the engine acquired by the data acquisition unit; a theoretical workload calculation unit (e.g., the theoretical workload calculation unit 44 described above) configured to calculate a theoretical workload (e.g., the theoretical workload Q described above) that is a theoretical value of the workload of the engine based on the fuel flow command value; an engine diagnosis unit (e.g., the above-mentioned engine diagnosis unit 46) configured to diagnose an abnormality of the engine based on the total workload calculated by the total workload calculation unit and the theoretical workload calculated by the theoretical workload calculation unit; Equipped with.

[0055] According to the engine diagnostic device described in [1] above, engine abnormalities (e.g., engine misfires, gas leaks from the fuel supply valve, etc.) can be diagnosed (detected) more quickly than when engine abnormalities are diagnosed based on the engine exhaust temperature.

[0056] [2] In some embodiments, in the engine diagnostic device according to [1] above, The engine diagnosis unit is configured to diagnose an abnormality in the engine based on a difference value (e.g., the above-mentioned QE, EQ) between the total workload calculated by the total workload calculation unit and the theoretical workload calculated by the theoretical workload calculation unit.

[0057] According to the engine diagnostic device described in [2] above, abnormalities such as engine misfires and gas leaks from the fuel supply valve can be diagnosed (detected) more quickly than when engine abnormalities are diagnosed based on the engine exhaust temperature.

[0058] [3] In some embodiments, in the engine diagnostic device according to [1] or [2] above, The engine diagnosis unit is configured to diagnose that a misfire has occurred in the engine when a difference value (e.g., the above-mentioned QE) obtained by subtracting the total workload calculated by the total workload calculation unit from the theoretical workload calculated by the theoretical workload calculation unit is greater than a threshold value (e.g., the above-mentioned threshold value Th1).

[0059] According to the engine diagnosis device described in [3] above, the occurrence of engine misfire can be diagnosed (detected) more quickly than in the case where an engine abnormality is diagnosed based on the engine exhaust temperature.

[0060] [4] In some embodiments, in the engine diagnostic device according to any one of [1] to [3] above, The engine diagnosis unit is configured to diagnose that a misfire has occurred in the engine when a difference value (e.g., the above-mentioned QE) obtained by subtracting the total workload calculated by the total workload calculation unit from the theoretical workload calculated by the theoretical workload calculation unit is greater than a threshold value (e.g., the above-mentioned threshold value Th1) for a predetermined period of time or more.

[0061] According to the engine diagnosis device described in [4] above, compared to a case where an engine abnormality is diagnosed based on the engine exhaust temperature, the occurrence of engine misfire can be diagnosed (detected) more quickly. Also, the occurrence of engine misfire can be diagnosed with high accuracy.

[0062] [5] In some embodiments, in the engine diagnostic device according to [3] or [4] above, The engine diagnosis device is configured to stop the supply of fuel to the engine when the engine diagnosis unit diagnoses that a misfire has occurred in the engine.

[0063] According to the engine diagnostic device described in [5] above, compared to a case where an engine abnormality is diagnosed based on the engine exhaust temperature, the occurrence of a misfire in the engine can be diagnosed (detected) quickly, and when a misfire occurs in the engine, the misfire can be diagnosed (detected) quickly and the fuel supply to the engine can be stopped quickly. Therefore, it is possible to suppress the emission of unburned gas into the exhaust passage of the engine due to the misfire, and to suppress the occurrence of afterfire (rapid combustion caused by unburned gas remaining in the exhaust passage being ignited by high-temperature exhaust gas discharged from the combustion chamber in the next combustion cycle) caused by the retention of unburned gas in the exhaust passage.

[0064] [6] In some embodiments, in the engine diagnostic device according to any one of [1] to [5] above, The engine diagnosis unit is configured to diagnose that a fuel leak is occurring in a fuel supply valve of the engine (e.g., the above-mentioned fuel supply valve 24) when a difference value (e.g., the above-mentioned EQ) obtained by subtracting the theoretical work calculated by the theoretical work calculation unit from the total work calculated by the total work calculation unit is greater than a threshold value (e.g., the above-mentioned threshold value Th2).

[0065] According to the engine diagnostic device described in [6] above, it is possible to quickly diagnose (detect) the occurrence of a fuel leak in the engine fuel supply valve, compared to a case in which an engine abnormality is diagnosed based on the engine exhaust temperature.

[0066] [7] In some embodiments, in the engine diagnostic device according to any one of [1] to [6] above, The engine diagnosis unit is configured to diagnose that a fuel leak is occurring in a fuel supply valve of the engine when a state in which a difference value (e.g., the above-mentioned EQ) obtained by subtracting the theoretical work calculated by the theoretical work calculation unit from the total work calculation unit is greater than a threshold value (e.g., the above-mentioned threshold value Th2) continues for a predetermined time or more.

[0067] According to the engine diagnosis device described in [7] above, compared to a case where an engine abnormality is diagnosed based on the engine exhaust temperature, it is possible to diagnose (detect) the occurrence of a fuel leak in the engine fuel supply valve more quickly. Also, it is possible to diagnose the occurrence of a fuel leak in the engine fuel supply valve with high accuracy.

[0068] [8] In some embodiments, in the engine diagnostic device according to any one of [1] to [7] above, The engine diagnosis unit is configured to diagnose that a misfire has occurred in the engine when a difference value (e.g., the above-mentioned QE) obtained by subtracting the total workload calculated by the total workload calculation unit from the theoretical workload calculated by the theoretical workload calculation unit is greater than a first threshold value (e.g., the above-mentioned threshold value Th1), and to diagnose that a fuel leak has occurred in a fuel supply valve of the engine when a difference value (e.g., the above-mentioned EQ) obtained by subtracting the theoretical workload calculated by the theoretical workload calculation unit from the total workload calculated by the total workload calculation unit is greater than a second threshold value (e.g., the above-mentioned threshold value Th2).

[0069] According to the engine diagnostic device described in [8] above, compared to a case where engine abnormalities are diagnosed based on the engine exhaust temperature, the occurrence of engine misfires and fuel leaks from the fuel supply valve can be diagnosed (detected) more quickly.

[0070] [9] In some embodiments, in the engine diagnostic device according to any one of [1] to [8] above, The engine diagnosis unit is configured to diagnose that a misfire has occurred in the engine when a state in which a difference value (e.g., the above-mentioned QE) obtained by subtracting the total work calculated by the total work calculation unit from the theoretical work calculation unit is greater than a first threshold value (e.g., the above-mentioned threshold value Th1) continues for a predetermined time or more, and to diagnose that a fuel leak has occurred in a fuel supply valve of the engine when a difference value (e.g., the above-mentioned EQ) obtained by subtracting the theoretical work calculated by the theoretical work calculation unit from the total work calculation unit is greater than a second threshold value (e.g., the above-mentioned threshold value Th2) continues for a predetermined time or more.

[0071] According to the engine diagnosis device described in [9] above, compared to a case where an engine abnormality is diagnosed based on the engine exhaust temperature, the occurrence of an engine misfire and a fuel leak at the fuel supply valve can be diagnosed (detected) more quickly. Also, the occurrence of an engine misfire and a fuel leak at the fuel supply valve can be diagnosed with high accuracy.

[0072]

[10] In some embodiments, in the engine diagnostic device according to any one of [6] to [9] above, The engine diagnosis device is configured to stop the supply of fuel to the engine when the engine diagnosis unit diagnoses that a fuel leak is occurring in the fuel supply valve of the engine.

[0073] According to the engine diagnosis device described in

[10] above, compared to a case where an engine abnormality is diagnosed based on the engine exhaust temperature, it is possible to diagnose (detect) a fuel leak at the engine fuel supply valve quickly, and therefore, when a fuel leak occurs at the engine fuel supply valve, it is possible to diagnose (detect) the fuel leak quickly and stop the fuel supply to the engine quickly. Therefore, it is possible to suppress the emission of unburned gas into the engine exhaust passage caused by the fuel leak, and to suppress the occurrence of afterfire caused by the accumulation of unburned gas in the exhaust passage.

[0074]

[11] In some embodiments, in the engine diagnostic device according to [8] or [9] above, The second threshold is less than the first threshold.

[0075] According to the knowledge of the present inventors, the absolute value of the difference between the total work and the theoretical work when a fuel leak occurs at an engine fuel supply valve (the value obtained by subtracting the theoretical work from the total work) is more likely to be smaller than the difference between the total work and the theoretical work when an engine misfire occurs (the value obtained by subtracting the total work from the theoretical work). Therefore, as described in

[11] above, by making the second threshold smaller than the first threshold, engine misfire and fuel leakage at the fuel supply valve can be diagnosed (detected) with high accuracy.

[0076]

[12] In some embodiments, in the engine diagnostic device according to any one of [1] to

[11] above, The engine is connected to a generator (such as the generator 6 described above); The value relating to the actual output of the engine is the output of the generator (for example, the generator output P mentioned above).

[0077] According to the engine diagnostic device described in

[12] above, in an engine power generation system that generates electricity using engine power, it is possible to quickly diagnose (detect) abnormalities such as engine misfires and fuel leaks from the fuel supply valve, compared to a case in which engine abnormalities are diagnosed based on the engine exhaust temperature.

[0078]

[13] In some embodiments, in the engine diagnostic device according to any one of [1] to

[12] above, The theoretical work load calculation unit is configured to calculate the theoretical work load by multiplying the fuel flow rate command value by a value related to the heat value of the fuel (e.g., the above-mentioned lower heating value LHV) and a thermal efficiency of the engine (e.g., the above-mentioned thermal efficiency η).

[0079] According to the engine diagnostic device described in

[13] above, abnormalities such as engine misfires and fuel leaks from the fuel supply valve can be diagnosed (detected) quickly and accurately.

[0080]

[14] An engine power generation system according to at least one embodiment of the present disclosure, The engine diagnostic device includes an engine, a generator connected to the engine, and the engine diagnostic device described in

[12] above.

[0081] According to the engine power generation system described in

[14] above, abnormalities such as engine misfires and gas leaks from the fuel supply valve can be diagnosed (detected) more quickly than when engine abnormalities are diagnosed based on the engine exhaust temperature. [Explanation of symbols]

[0082] 2 Engine power generation system 4 Engine 6. Generator 8 Engine Controller 10 Cylinders 12 Piston 14 Crankshaft 16 Combustion chamber 18 Intake passage 20 Exhaust passage 22 Fuel supply path 24 Fuel supply valve 26 Shut-off valve 28 Master 30 branch pipe 32 Rotation Sensor 34 Output meter 40 Data Acquisition Section 41 Kinetic energy change rate calculation section 42 Total Workload Calculation Unit 44 Theoretical Workload Calculation Section 46 Engine Diagnostics Department 72 processors 74 RAM 76 ROM 78 HDD 80 Input I / F 82 Output I / F 84 Bus E Total Work K total kinetic energy Ne Engine RPM P Generator output Q Theoretical Workload Qgas Fuel flow command value Th1, Th2 thresholds t1,t2,t3,t4 time

Claims

1. a data acquisition unit configured to acquire an actual engine speed, a value related to an actual output of the engine, and a fuel flow command value for controlling a fuel flow rate of the engine; a kinetic energy change rate calculation unit that calculates a value relating to a time change rate of a total kinetic energy, which is a sum of kinetic energies of the engine and a device driven by the engine, based on the actual rotation speed of the engine acquired by the data acquisition unit; a total work amount calculation unit configured to calculate a total work amount by summing a value relating to a time rate of change of the total kinetic energy calculated by the kinetic energy change rate calculation unit and a value relating to an actual output of the engine acquired by the data acquisition unit; a theoretical workload calculation unit configured to calculate a theoretical workload, which is a theoretical value of the workload of the engine, based on the fuel flow rate command value; an engine diagnosis unit configured to diagnose an abnormality of the engine based on the total workload calculated by the total workload calculation unit and the theoretical workload calculated by the theoretical workload calculation unit; An engine diagnostic device comprising:

2. 2. The engine diagnosis device according to claim 1, wherein the engine diagnosis unit is configured to diagnose an abnormality in the engine based on a difference value between the total workload calculated by the total workload calculation unit and the theoretical workload calculated by the theoretical workload calculation unit.

3. 2. The engine diagnosis device according to claim 1, wherein the engine diagnosis unit is configured to diagnose that a misfire has occurred in the engine when a difference value obtained by subtracting the total workload calculated by the total workload calculation unit from the theoretical workload calculated by the theoretical workload calculation unit is greater than a threshold value.

4. 2. The engine diagnosis device according to claim 1, wherein the engine diagnosis unit is configured to diagnose that a misfire has occurred in the engine when a state in which a difference value obtained by subtracting the total workload calculated by the total workload calculation unit from the theoretical workload calculated by the theoretical workload calculation unit is greater than a threshold value continues for a predetermined time or more.

5. 5. The engine diagnostic device according to claim 3, further comprising: a stoppage of fuel supply to the engine when the engine diagnostic unit diagnoses that a misfire has occurred in the engine.

6. 2. The engine diagnostic device according to claim 1, wherein the engine diagnostic unit is configured to diagnose that a fuel leak is occurring in a fuel supply valve of the engine when a difference value obtained by subtracting the theoretical workload calculated by the theoretical workload calculation unit from the total workload calculated by the total workload calculation unit is greater than a threshold value.

7. 2. The engine diagnosis device according to claim 1, wherein the engine diagnosis unit is configured to diagnose that a fuel leak is occurring in a fuel supply valve of the engine when a state in which a difference value obtained by subtracting the theoretical workload calculated by the theoretical workload calculation unit from the total workload calculated by the total workload calculation unit is greater than a threshold value continues for a predetermined time or more.

8. 2. The engine diagnosis device according to claim 1, wherein the engine diagnosis unit is configured to diagnose that a misfire has occurred in the engine when a difference value obtained by subtracting the total workload calculated by the total workload calculation unit from the theoretical workload calculated by the theoretical workload calculation unit is greater than a first threshold value, and to diagnose that a fuel leak has occurred in a fuel supply valve of the engine when a difference value obtained by subtracting the theoretical workload calculated by the theoretical workload calculation unit from the total workload calculation unit is greater than a second threshold value.

9. 2. The engine diagnosis device according to claim 1, wherein the engine diagnosis unit is configured to diagnose that a misfire has occurred in the engine when a state in which a difference value obtained by subtracting the total workload calculated by the total workload calculation unit from the theoretical workload calculated by the theoretical workload calculation unit is greater than a first threshold value continues for a predetermined time or more, and to diagnose that a fuel leak has occurred in a fuel supply valve of the engine when a state in which a difference value obtained by subtracting the theoretical workload calculated by the theoretical workload calculation unit from the total workload calculation unit is greater than a second threshold value continues for a predetermined time or more.

10. 10. The engine diagnosis device according to claim 6, further comprising: a controller configured to stop a supply of fuel to the engine when the engine diagnosis unit diagnoses that a fuel leak is occurring in the fuel supply valve of the engine.

11. The engine diagnosis device according to claim 8 or 9, wherein the second threshold value is smaller than the first threshold value.

12. The engine is connected to a generator; 2. The engine diagnostic device according to claim 1, wherein the value relating to the actual output of the engine is an output of the generator.

13. 2. The engine diagnostic device according to claim 1, wherein the theoretical workload calculation unit is configured to calculate the theoretical workload by multiplying the fuel flow rate command value by a value related to a heat value of the fuel and a thermal efficiency of the engine.

14. An engine power generation system comprising: an engine; a generator connected to the engine; and the engine diagnostic device according to claim 12.

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