Anomaly detection device

Abstract

To provide an abnormality diagnostic device that can appropriately diagnose the nature of abnormalities occurring in fuel cell systems. [Solution] The abnormality diagnosis device determines that an abnormality has occurred in the power system if the first determination condition is met, that the voltage of the DC power supplied by the power conversion circuit to the DC auxiliary equipment is in a predetermined low voltage state, and the second determination condition is met, that the first determination condition has been met a set number of times within a predetermined period in the past, and the third determination condition is not met, that the system voltage in the power system measured by the system voltage measuring instrument is within the normal range.

Description

Technical Field

[0001] The present invention relates to an abnormality diagnosis device that diagnoses the content of an abnormality occurring in a fuel cell device based on information received via an information communication line from the fuel cell device installed in a facility.

Background Art

[0002] Patent Document 1 (Japanese Patent Application Laid-Open No. 2016-184319) describes a system that can diagnose and identify a failure location in a power generation system and suppress misdiagnosis during a failure. Specifically, in the system described in Patent Document 1, when the power generation system fails, failure data including the detection signal history at each part of the power generation device is generated by each of a plurality of detection means provided at each part of the power generation device. Then, from the past failure data recorded in the database, correlation failure data having a strong correlation with the current failure data is selected. Further, the failure diagnosis result and the failure countermeasure record associated with the selected correlation failure data are output. Thus, in the system described in Patent Document 1, the past failure data having a strong correlation with the failure data including the detection signal history detected when the current failure occurs is specified, and it is considered that the current failure also occurred due to the same failure cause as the past failure data having a strong correlation.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is also a need for a method of diagnosing the operating state of a fuel cell device without relying on a statistical method such as the strength of the correlation.

[0005] The present invention has been made in view of the above-mentioned problems, and its purpose is to provide an abnormality diagnosis device that can appropriately diagnose the nature of abnormalities occurring in a fuel cell device. [Means for solving the problem]

[0006] A characteristic configuration of the abnormality diagnosis device according to the present invention for achieving the above objective is an abnormality diagnosis device that diagnoses the nature of an abnormality occurring in a fuel cell device based on information received from the fuel cell device installed in a facility via an information communication line, The fuel cell device comprises an outer container and a hot module having an inner container provided in the space inside the outer container, The hot module has, in the inner space inside the inner container, a vaporizer for vaporizing the supplied reforming water, a reformer for steam reforming raw fuel using steam supplied from the vaporizer to produce fuel gas, a cell stack having a plurality of fuel cell cells that generate electricity using the fuel gas produced in the reformer, and a combustion unit for burning off-gas discharged from the cell stack. The fuel cell device comprises a power conversion circuit that can convert the power generated by the cell stack into desired AC power and output the converted power to a power line connected to the power grid, and can convert the power generated by the cell stack and the power supplied from the power line into DC power of a target auxiliary voltage and supply it to a DC auxiliary device, a grid voltage measuring instrument that measures the grid voltage of the power supplied from the power grid to the power line, and a control device that controls the operation of the fuel cell device. The key point is that if a first determination condition is met, which is that the voltage of the DC power supplied by the power conversion circuit to the DC auxiliary equipment is in a predetermined low voltage state, and a second determination condition is met, which is that the first determination condition has been met a set number of times within a predetermined period in the past, and a third determination condition is not met, which is that the system voltage in the power system measured by the system voltage measuring instrument is within the normal range, then it is determined that an abnormality has occurred in the power system.

[0007] According to the above characteristic configuration, the abnormality diagnosis device determines that an abnormality has occurred in the power system if the first determination condition is met, that the voltage of the DC power supplied by the power conversion circuit to the DC auxiliary equipment is in a predetermined low voltage state, and the second determination condition is met, that the first determination condition has been met a set number of times within a predetermined period in the past, and the third determination condition is not met, that the system voltage in the power system measured by the system voltage meter is within the normal range. In other words, the abnormality diagnosis device can automatically determine the diagnosis result for abnormalities that appear in the voltage of the DC power supplied by the power conversion circuit to the DC auxiliary equipment.

[0008] For example, if maintenance personnel are dispatched based solely on the fact that an abnormality has occurred in the operation or measurement results of the equipment in a fuel cell system, the maintenance personnel would need to make a diagnosis of the abnormality on the spot. However, with this feature configuration, the abnormality diagnosis device automatically identifies the diagnosis result for that abnormality, so maintenance personnel can prepare in advance according to the diagnosis result before being dispatched. Therefore, we can provide an abnormality diagnosis device that can appropriately diagnose the nature of abnormalities occurring in fuel cell devices.

[0009] Another characteristic configuration of the abnormality diagnosis device according to the present invention is that if the first determination condition is met, the second determination condition is met, the third determination condition is met, and the fourth determination condition, which is that the voltage of the DC power supplied by the power conversion circuit to the DC auxiliary equipment is within a set range including zero, is not met, then it is determined that an abnormality has occurred in the power conversion circuit.

[0010] According to the above characteristic configuration, the abnormality diagnosis device can automatically diagnose that an abnormality has occurred in the power conversion circuit if the first determination condition is met, the second determination condition is met, the third determination condition is met, and the fourth determination condition, which is that the voltage of the DC power supplied by the power conversion circuit to the DC auxiliary equipment is within a set range including zero, is not met.

[0011] Another characteristic configuration of the abnormality diagnosis device according to the present invention is that the fuel cell device includes a hot water storage tank for storing hot water, a heat exchanger for heat recovery that performs heat exchange between the hot water and exhaust gas containing gas generated by combustion in the combustion section, which is discharged to the outside of the inner container, and the hot water, and a thermal fuse provided in the middle of the power supply line from the power conversion circuit to the control device, which cuts the power supply line when the temperature of the hot water supplied from the heat recovery heat exchanger to the hot water storage tank reaches a predetermined high temperature. The point is that if the first determination condition is met, the second determination condition is met, the third determination condition is met, and the fourth determination condition is met, which is that the voltage of the DC power supplied by the power conversion circuit to the DC auxiliary equipment is within a set range including zero, then it is determined that the thermal fuse has cut the power supply line.

[0012] According to the above characteristic configuration, the abnormality diagnosis device can automatically diagnose that the thermal fuse has cut the power supply line if the first determination condition is met, the second determination condition is met, the third determination condition is met, and the fourth determination condition is met, which is that the voltage of the DC power supplied by the power conversion circuit to the DC auxiliary equipment is within a set range including zero.

[0013] Another characteristic configuration of the abnormality diagnosis device according to the present invention is that the fuel cell device comprises a hot water storage tank for storing hot water, a heat exchanger for heat recovery that performs heat exchange between the hot water and exhaust gas containing gas generated by combustion in the combustion section, which is discharged to the outside of the inner container, and a thermal fuse provided in the middle of the power supply line from the power conversion circuit to the control device, which cuts the power supply line when the temperature of the hot water supplied from the heat recovery heat exchanger to the hot water storage tank reaches a predetermined high temperature. The point is that if the first determination condition is met, and the second determination condition is not met, and the fifth determination condition, which is that the system voltage in the power system, the temperature of the hot water supplied from the heat recovery heat exchanger to the hot water storage tank, and the output voltage of the cell stack are obtained when the first determination condition is met, is not met, and the sixth determination condition, which is that the low voltage state occurred while the cell stack was stopped generating power, is not met, then it is determined that the thermal fuse has cut the power supply line or that an abnormality has occurred in the power conversion circuit.

[0014] According to the above characteristic configuration, the abnormality diagnosis device can automatically diagnose that a thermal fuse has cut the power supply line or that an abnormality has occurred in the power conversion circuit section if the first determination condition is met, the second determination condition is not met, the fifth determination condition is not met (i.e., the system voltage in the power system, the temperature of the hot water supplied from the heat recovery heat exchanger to the hot water storage tank, and the output voltage of the cell stack are obtained when the first determination condition is met), and the sixth determination condition is not met (i.e., a low voltage condition occurred while the cell stack was stopped generating power).

[0015] Another characteristic configuration of the abnormality diagnosis device according to the present invention is that if the first determination condition is met, the second determination condition is not met, the fifth determination condition is not met, the sixth determination condition is met, and the seventh determination condition, which states that the temperature of the hot water after heat exchange with the exhaust gas is in a predetermined high-temperature state, is not met, then it is determined that an abnormality has occurred in the hot module.

[0016] According to the above characteristic configuration, the abnormality diagnosis device can automatically diagnose that an abnormality has occurred in the hot module if the first determination condition is met, the second determination condition is not met, the fifth determination condition is not met, the sixth determination condition is met, and the seventh determination condition, which states that the temperature of the hot water after heat exchange with the exhaust gas is at a predetermined high temperature, is not met.

[0017] Another characteristic configuration of the abnormality diagnosis device according to the present invention is that when the first determination condition is met, the second determination condition is not met, the fifth determination condition is not met, the sixth determination condition is met, and the seventh determination condition is met, which states that the temperature of the hot water after heat exchange with the exhaust gas in the heat exchanger for heat recovery is at a predetermined high temperature, the device determines that an abnormality has occurred in the heat recovery system in which the hot water supplied from the hot water storage tank recovers heat from the exhaust gas in the heat exchanger for heat recovery and returns to the hot water storage tank.

[0018] According to the above characteristic configuration, the abnormality diagnosis device can automatically diagnose that an abnormality has occurred in the heat recovery system in which hot water supplied from the hot water storage tank recovers heat from the exhaust gas in the heat recovery heat exchanger and returns to the hot water storage tank, if the first determination condition is met, the second determination condition is not met, the fifth determination condition is not met, the sixth determination condition is met, and the seventh determination condition is met, which is that the temperature of the hot water after heat exchange with the exhaust gas in the heat recovery heat exchanger is at a predetermined high temperature.

[0019] Another characteristic configuration of the abnormality diagnosis device according to the present invention is that the fuel cell device includes a hot water storage tank for storing hot water, a heat exchanger for heat recovery that performs heat exchange between the hot water and exhaust gas containing gas generated by combustion in the combustion section, which is discharged to the outside of the inner container, and the hot water, and a thermal fuse provided in the middle of the power supply line from the power conversion circuit to the control device, which cuts the power supply line when the temperature of the hot water supplied from the heat recovery heat exchanger to the hot water storage tank reaches a predetermined high temperature. The key point is that if the first determination condition is met, the second determination condition is not met, and the fifth determination condition is met, which is that the system voltage in the power system, the temperature of the hot water supplied from the heat recovery heat exchanger to the hot water storage tank, and the output voltage of the cell stack are obtained when the first determination condition is met, and the eighth determination condition is not met, then it is determined that an abnormality has occurred in the power system.

[0020] According to the above characteristic configuration, when the first determination condition is satisfied, the second determination condition is not satisfied, the fifth determination condition that the values of the system voltage in the power system, the temperature of the hot water supplied from the waste heat recovery heat exchanger to the hot water storage tank, and the output voltage of the cell stack when the first determination condition is satisfied are obtained is satisfied, and when the eighth determination condition that the system voltage in the power system is within the normal range is not satisfied, the diagnosis that an abnormality has occurred in the power system can be automatically performed.

[0021] Another characteristic configuration of the abnormality diagnosis device according to the present invention is that the first determination condition is satisfied, the second determination condition is not satisfied, the fifth determination condition is satisfied, the eighth determination condition is satisfied, the ninth determination condition that the low voltage state has occurred during the power generation stop of the cell stack is not satisfied, and when the tenth determination condition that the temperature of the hot water supplied from the waste heat recovery heat exchanger to the hot water storage tank is in a predetermined high temperature state is satisfied, it is determined that an abnormality has occurred in the waste heat recovery system in which the hot water supplied from the hot water storage tank recovers heat from the exhaust gas in the waste heat recovery heat exchanger and returns to the hot water storage tank.

[0022] According to the above characteristic configuration, when the first determination condition is satisfied, the second determination condition is not satisfied, the fifth determination condition is satisfied, the eighth determination condition is satisfied, the ninth determination condition that the low voltage state has occurred during the power generation stop of the cell stack is not satisfied, and when the tenth determination condition that the temperature of the hot water supplied from the waste heat recovery heat exchanger to the hot water storage tank is in a predetermined high temperature state is satisfied, the diagnosis that an abnormality has occurred in the waste heat recovery system in which the hot water supplied from the hot water storage tank recovers heat from the exhaust gas in the waste heat recovery heat exchanger and returns to the hot water storage tank can be automatically performed.

[0023] Another characteristic configuration of the abnormality diagnosis device according to the present invention is that when the first determination condition is satisfied, the second determination condition is not satisfied, the fifth determination condition is satisfied, the eighth determination condition is satisfied, the ninth determination condition that the low voltage state occurs during the power generation stop of the cell stack is not satisfied, the tenth determination condition that the temperature of the hot water supplied from the waste heat recovery heat exchanger to the hot water storage tank is in a predetermined high temperature state is not satisfied, and the eleventh determination condition that the output voltage of the cell stack is not less than a predetermined value is not satisfied, it is determined that an abnormality has occurred in the hot module.

[0024] According to the above characteristic configuration, when the abnormality diagnosis device satisfies the first determination condition, does not satisfy the second determination condition, satisfies the fifth determination condition, satisfies the eighth determination condition, does not satisfy the ninth determination condition that the low voltage state occurs during the power generation stop of the cell stack, does not satisfy the tenth determination condition that the temperature of the hot water supplied from the waste heat recovery heat exchanger to the hot water storage tank is in a predetermined high temperature state, and does not satisfy the eleventh determination condition that the output voltage of the cell stack is not less than a predetermined value, it can automatically diagnose that an abnormality has occurred in the hot module.

[0025] Another characteristic configuration of the abnormality diagnosis device according to the present invention is that when the first determination condition is satisfied, the second determination condition is not satisfied, the fifth determination condition is satisfied, the eighth determination condition is satisfied, the ninth determination condition is not satisfied, the tenth determination condition is not satisfied, the eleventh determination condition is satisfied, and the twelfth determination condition that the voltage of the DC power supplied by the power conversion circuit unit to the DC auxiliary machine is within a set range including zero is not satisfied, it is determined that an abnormality has occurred in the power conversion circuit unit.

[0026] According to the above characteristic configuration, the abnormality diagnosis device can automatically diagnose that an abnormality has occurred in the power conversion circuit if the first determination condition is met, the second determination condition is not met, the fifth determination condition is met, the eighth determination condition is met, the ninth determination condition is not met, the tenth determination condition is not met, the eleventh determination condition is met, and the twelfth determination condition, which states that the voltage of the DC power supplied by the power conversion circuit to the DC auxiliary equipment is within a set range including zero, is not met.

[0027] Another characteristic configuration of the abnormality diagnosis device according to the present invention is that if the first determination condition is met, the second determination condition is not met, the fifth determination condition is met, the eighth determination condition is met, the ninth determination condition is not met, the tenth determination condition is not met, the eleventh determination condition is met, and the twelfth determination condition is met, which is that the voltage of the DC power supplied by the power conversion circuit to the DC auxiliary equipment is within a set range including zero, then it is determined that the thermal fuse has cut the power supply line.

[0028] According to the above characteristic configuration, the abnormality diagnosis device can automatically diagnose that a thermal fuse has severed a power supply line if the first determination condition is met, the second determination condition is not met, the fifth determination condition is met, the eighth determination condition is met, the ninth determination condition is not met, the tenth determination condition is not met, the eleventh determination condition is met, and the twelfth determination condition is met, which includes zero as the voltage of the DC power supplied by the power conversion circuit to the DC auxiliary equipment. [Brief explanation of the drawing]

[0029] [Figure 1] This diagram shows the configuration of a diagnostic system equipped with an abnormality detection device. [Figure 2] This is a diagram showing the configuration of a fuel cell system. [Figure 3] This diagram illustrates the electrical connection configuration between the power grid, fuel cell equipment, and power consumption devices. [Figure 4] This is a flowchart illustrating an example of anomaly diagnosis processing. [Modes for carrying out the invention]

[0030] An abnormality diagnosis device 4 according to an embodiment of the present invention will be described below with reference to the drawings. Figure 1 shows the configuration of a diagnostic system equipped with an abnormality diagnosis device 4. Figure 2 shows the configuration of a fuel cell device 10. Figure 3 is a diagram illustrating the electrical connection configuration between the power grid 63, the fuel cell device 10, and the power consumption device 5.

[0031] As shown in the figure, a fuel cell device 10 is installed in a dwelling unit and a facility 1 such as a business. Facility 1 is also equipped with a power consumption device 5, a gas consumption device 6, and a HEMS (Home Energy Management System) 78. The HEMS 78 is a device that controls the operation of controlled devices such as the power consumption device 5, the fuel cell device 10, and the gas consumption device 6. It communicates information with the controlled devices via a communication line, receiving information from each device and transmitting information to each device. The HEMS 78 can also transmit the information received from each device to an abnormality diagnosis device 4, etc., via an information communication line 2. The operation of the fuel cell device 10 is controlled by a fuel cell control unit 49, as will be described later.

[0032] The power consumption device 5 and the fuel cell device 10 are connected to a power line 8 that is connected to the power grid 63, and can receive power from the power grid 63. The power generated by the fuel cell device 10 can also be supplied to the power grid 63 via the power line 8. The gas consumption device 6 and the fuel cell device 10 can receive a supply of gas, such as city gas, from a gas supply pipe 9. Figure 1 shows two facilities 1, but the number can be changed as needed. The gas supplied from the gas supply pipe 9, for example, a gas containing hydrocarbons such as city gas, corresponds to the "raw fuel" of this invention, and may also be referred to as the raw fuel in the following description.

[0033] The fuel cell device 10 can access the information communication line 2 via or without the HEMS 78. The fuel cell device 10 can then communicate information with the abnormality diagnosis device 4, information provision server device 3, maintenance personnel terminal device 60, manufacturing personnel terminal device 61, administrator terminal device 62, and other devices connected to the information communication line 2.

[0034] The fuel cell device 10 comprises a hot module 13 having an outer container 11 and an inner container 12 provided in the inner space 48 of the outer container 11. The fuel cell device 10 has various components inside the outer container 11. The configuration of the fuel cell device 10 will be described below, divided into the hot module 13, raw fuel supply system, air supply system, recirculating gas supply system, water recovery system, reforming water supply system, and waste heat recovery system.

[0035] [Hot Module 13] Inside the outer container 11 is a hot module 13 that houses equipment such as a cell stack 18 that operates in a high-temperature environment. Specifically, the hot module 13 contains a vaporizer 14, a reformer 15, a manifold 16, a cell stack 18, etc., in the inner space 7 inside the inner container 12. The vaporizer 14 vaporizes the supplied reforming water. The reformer 15 steam reforms the raw fuel using the steam supplied from the vaporizer 14 to produce a fuel gas containing hydrogen. In addition, the hot module 13 is equipped with a reformer temperature measuring instrument T1 that measures the temperature of the reformer 15, for example, the temperature of the reforming catalyst (not shown) housed in the reformer 15. Furthermore, the hot module 13 is equipped with an inner temperature measuring instrument T8 that measures the temperature inside the inner space 7.

[0036] The cell stack 18 has multiple fuel cell cells 17 that generate electricity using fuel gas supplied from the reformer 15 via the fuel gas supply line L2. For example, the fuel gas generated in the reformer 15 travels through the fuel gas supply line L2 to the manifold 16, where it is distributed to each fuel cell cell 17.

[0037] The space above the cell stack 18 becomes a combustion section 19 where the off-gas discharged from the cell stack 18 is burned. This combustion heat is transferred to the vaporizer 14 and reformer 15 above it. The temperature of the combustion section 19 is measured by a combustion section temperature measuring instrument T2. The igniter 20 ignites the off-gas.

[0038] The inner container 12 of the hot module 13 is provided with an air intake port 21 used to supply air from the outside to the inner space 7 and an exhaust port 22 used to exhaust air from the inner space 7 to the outside. Specifically, an air supply passage L10 is connected to the air intake port 21 of the hot module 13, supplying air to the inside of the hot module 13. Gas present inside the hot module 13 is discharged to the outside of the hot module 13 through the exhaust port 22. The exhaust port 22 is provided with a combustion catalyst section 23 through which exhaust gas discharged from the inner space 7, including gas generated by combustion in the combustion section 19, passes, and catalytic combustion is performed on oxidizable substances (e.g., hydrogen, carbon monoxide, etc.) contained in the exhaust gas. The fuel cell device 10 is equipped with an exhaust gas temperature measuring instrument T10 that measures the temperature of the exhaust gas discharged to the outside of the inner container 12. Specifically, the exhaust gas temperature measuring instrument T10 measures the temperature of the combustion catalyst section 23.

[0039] The exhaust gas that has passed through the combustion catalyst section 23 is supplied to the heat recovery heat exchanger 34. In the heat recovery heat exchanger 34, heat exchange takes place between the exhaust gas, which contains gas generated by combustion in the combustion section 19 and is discharged to the outside of the inner container 12, and hot water, which will be described later as a heat transfer medium. In other words, the exhaust gas is cooled, and the water contained in the exhaust gas condenses. The heat recovery heat exchanger 34 is equipped with a heat exchange temperature measuring instrument T9 that measures the temperature of the part in the heat recovery heat exchanger 34 where the exhaust gas and hot water are exchanging heat. For example, the heat exchange temperature measuring instrument T9 measures the temperature of the exhaust gas or hot water at the part where the exhaust gas and hot water are exchanging heat.

[0040] The fuel cell device 10 includes an exhaust gas flow path L4 through which exhaust gas flows after heat exchange with hot water in a heat recovery heat exchanger 34, a gas-liquid separation unit 35 that separates condensate contained in the exhaust gas after heat exchange with hot water in the heat recovery heat exchanger 34, a water recovery path L5 through which the condensate separated by the gas-liquid separation unit 35 flows, and a water purifier 37 that removes impurities contained in the condensate recovered by the water recovery path L5. Specifically, the gas-liquid separation unit 35 is provided downstream of the heat recovery heat exchanger 34. The gaseous phase component of the exhaust gas is discharged to the outside of the outer container 11 through the exhaust gas flow path L4, and the liquid phase component of the exhaust gas is supplied to the water purifier 37 through the water recovery path L5.

[0041] The fuel cell device 10 includes an air intake 67 provided in the outer container 11 for taking in air from the outside into the inner space 48 of the outer container 11, and a ventilation port 68 provided in the outer container 11 as an air outlet for discharging air from the inner space 48 of the outer container to the outside. In addition, the fuel cell device 10 includes a ventilation fan 59 for ventilating the air in the inner space 48 of the outer container via the air intake 67 and the ventilation port 68, and a ventilation air filter 77 provided in the air intake 67 for removing foreign matter contained in the air taken in from the outside into the inner space 48 of the outer container. It is equipped with.

[0042] When the ventilation fan 59 is operating normally, the deviation between the actual rotational speed of the ventilation fan 59 and its target rotational speed will be less than the set value. In other words, if the deviation between the actual rotational speed of the ventilation fan 59 and its predetermined target rotational speed is greater than or equal to the set value, there is a high probability that a malfunction is occurring in the ventilation fan 59.

[0043] Furthermore, the fuel cell device 10 is equipped with a space temperature measuring instrument T3 inside the outer container 11 to measure the temperature of the space 48 inside the outer container 11. The space 48 inside the outer container 11 is also equipped with a gas measuring instrument 43 that can measure the concentration of flammable gas present in the space 48 inside the outer container 11. For example, if flammable gas leaks into the space 48 inside the outer container from the hot module 13, raw fuel supply system, reflux gas supply system, etc., the concentration of flammable gas measured by the gas measuring instrument 43 may increase.

[0044] [Raw and fuel supply system] The raw material and fuel supply system is a system that supplies raw materials and fuel to the reformer 15 via the raw material and fuel supply passage L1. Specifically, the raw material and fuel supply system includes a shut-off valve 26, a pressure measuring instrument 27, a raw material and fuel flow measuring instrument 28, a zero governor 29, a raw material and fuel blower 30, and a desulfurizer 31. The raw material and fuel supplied to the reformer 15 from outside the inner space 7 flows through the raw material and fuel supply passage L1.

[0045] The shut-off valve 26 can be switched to a state that allows or blocks the flow of raw fuel into the raw fuel supply line L1. The pressure measuring instrument 27 measures the pressure of the raw fuel flowing into the raw fuel supply line L1. The raw fuel blower 30 supplies raw fuel to the reformer 15 via the raw fuel supply line L1. Specifically, the raw fuel blower 30 adjusts the flow rate of raw fuel per unit time supplied to the reformer 15. The raw fuel flow rate measuring instrument 28 measures the flow rate of raw fuel per unit time supplied to the reformer 15 via the raw fuel supply line L1. For example, the raw fuel blower 30 increases or decreases the output of the raw fuel blower 30, for example, the duty cycle of the PWM control of the raw fuel blower 30, so that the flow rate of raw fuel measured by the raw fuel flow rate measuring instrument 28 reaches the target raw fuel flow rate. The zero governor 29 adjusts the pressure of the raw fuel flowing through the raw fuel supply line L1 to the same as atmospheric pressure. The desulfurizer 31 removes sulfur compounds and other substances contained in the raw fuel.

[0046] When the raw material and fuel are supplied normally by the raw material and fuel blower 30, the correlation between the output of the raw material and fuel blower 30 and its rotational speed will only show a deviation of less than a standard value. Furthermore, when the raw material and fuel are supplied normally by the raw material and fuel blower 30, the correlation between the output of the raw material and fuel blower 30 and the measured value of the raw material and fuel flow meter 28 will only show a deviation of less than a standard value. For example, if a standard rotational speed (200 rpm) or a standard measured value of the raw material and fuel flow meter 28 is determined for each output of the raw material and fuel blower 30 (e.g., 30%), then when the raw material and fuel are supplied normally by the raw material and fuel blower 30, the actual rotational speed will only deviate from the standard rotational speed by less than a standard value (e.g., less than ±30%), and the actual measured value of the raw material and fuel flow meter 28 will only deviate from the standard measured value by less than a standard value (e.g., less than ±30%). Furthermore, when the raw fuel blower 30 is supplying raw fuel normally, the deviation of the raw fuel flow rate measured by the raw fuel flow rate meter 28 from the predetermined target raw fuel flow rate will not exceed a set value. Moreover, when the raw fuel flow rate is being measured normally by the raw fuel flow rate meter 28, the correlation between the output of the raw fuel blower 30 and the raw fuel flow rate measured by the raw fuel flow rate meter 28 will not deviate beyond a standard value. The fuel cell control unit 49 can obtain information on the output and rotational speed of the raw fuel blower 30.

[0047] [Air supply system] The air supply system is a system that supplies air to the hot module 13 via the air supply passage L10. Air flows through the air supply passage L10 from outside the inner container 12 to the air inlet 21. The air blower 41 supplies air to the inner space 7 of the inner container 12 via the air supply passage L10 and the air inlet 21. Specifically, the air blower 41 adjusts the flow rate per unit time of the air supplied to the inside of the inner container 12. The air flow rate meter 42 measures the flow rate per unit time of the air supplied to the inner space 7 of the inner container 12 by the air blower 41. For example, the air blower 41 increases or decreases the output of the air blower 41, for example, the duty cycle of the PWM control of the air blower 41, so that the air flow rate measured by the air flow rate meter 42 is the target air flow rate. The foreign matter removal filter 40 removes (captures) foreign matter contained in the air supplied to the inner container 12 by the air blower 41.

[0048] When the air supply by the air blower 41 is functioning correctly, the correlation between the output of the air blower 41 and its rotational speed will only show a deviation below a standard value. Similarly, when the air supply by the air blower 41 is functioning correctly, the correlation between the output of the air blower 41 and the measured value of the air flow meter 42 will only show a deviation below a standard value. For example, if a standard rotational speed (200 rpm) or a standard measured value of the air flow meter 42 is determined for each output of the air blower 41 (e.g., 30%), then when the air supply by the air blower 41 is functioning correctly, the actual rotational speed will only deviate from the standard rotational speed by a deviation below a standard value (e.g., less than ±30%), and the actual measured value of the air flow meter 42 will only deviate from the standard measured value by a deviation below a standard value (e.g., less than ±30%). Furthermore, when the air supply by the air blower 41 is functioning correctly, the deviation of the measured value (air flow rate) of the air flow meter 42 from a predetermined target air flow rate will never exceed a set value. Furthermore, if the airflow measurement by the airflow measuring device 42 is performed correctly, there will be no deviation exceeding a standard value in the correlation between the output of the air blower 41 and the airflow measured by the airflow measuring device 42. The fuel cell control unit 49 can obtain information on the output and rotational speed of the air blower 41.

[0049] [Reflux gas supply system] The recirculating gas supply system is a system that supplies a portion of the fuel gas produced in the reformer 15 to the raw fuel supply line L1 via the recirculating gas supply line L3. The recirculating gas supply line L3 branches off from a branching point 24 in the middle of the fuel gas supply line L2 and merges with a confluence point 25 in the middle of the raw fuel supply line L1 upstream of the desulfurizer 31, supplying a portion of the fuel gas flowing through the fuel gas supply line L2 to the raw fuel supply line L1. This allows hydrogen to be supplied to the desulfurizer 31. The recirculating gas supply line L3 is drawn out from inside the hot module 13 to the outside. The orifice 33 is provided in the middle of the recirculating gas supply line L3 and adjusts the flow rate of the fuel gas per unit time flowing through the recirculating gas supply line L3. The temperature control member 32 is provided around at least a portion of the recirculating gas supply line L3 to maintain the temperature of the reformed gas flowing through the recirculating gas supply line L3. The condensate recovery unit 36 ​​recovers the condensate generated in the recirculating gas supply passage L3. The recirculating gas temperature measuring instrument T4 measures the temperature of the recirculating gas supply passage L3 at the location where the temperature control member 32 is installed, that is, the recirculating gas temperature, which is the temperature of the recirculating gas flowing through the recirculating gas supply passage L3. For example, the recirculating gas temperature measuring instrument T4 is a device that measures the temperature of the outer surface of the piping that constitutes the recirculating gas supply passage L3, or a device that measures the temperature inside the piping that constitutes the recirculating gas supply passage L3.

[0050] [Water recovery system] The water recovery system is a system for recovering water produced by the fuel cell device 10. The condensed water recovered using the water recovery channel L5 is supplied to the reforming water tank 38. In the illustrated example, the water recovery channel L5 has a first recovery channel L5a that recovers water from the gas-liquid separation unit 35 and a second recovery channel L5b that recovers water from the condensed water recovery unit 36. The condensed water recovered by the first recovery channel L5a and the second recovery channel L5b is supplied to the reforming water tank 38 via the water purifier 37. In other words, the reforming water tank 38 stores the water from which impurities have been removed by the water purifier 37 as reforming water used for steam reforming. The water purifier 37 is a device for removing impurities contained in the recovered condensed water. For example, the water purifier 37 is filled with ion exchange resin, etc., and removes electrolyte ions (for example, ionized and dissolved salts and ammonia, etc.) contained in the recovered condensed water using, for example, H + , OH - By replacing it with this, it performs the function of relatively lowering the concentration of electrolytes contained in the recovered condensed water (i.e., lowering the electrical conductivity).

[0051] [Water supply system for water treatment] The reformed water supply system is a system that supplies reformed water to the reformer 15 via the reformed water supply channel L6. The fuel cell device 10 includes, as part of the reformed water supply system, a reformed water tank 38 for storing reformed water, a reformed water supply channel L6 through which the reformed water supplied to the vaporizer 14 flows, and a reformed water pump 39 that supplies the reformed water stored in the reformed water tank 38 to the vaporizer 14 via the reformed water supply channel L6. Specifically, the reformed water pump 39 is installed in the middle of the reformed water supply channel L6 and adjusts the flow rate of the reformed water per unit time flowing through the reformed water supply channel L6.

[0052] [Heat recovery system] The waste heat recovery system is a system for recovering heat generated by the fuel cell device 10. The waste heat recovery system includes a hot water storage tank 45 as a heat transfer medium, a water supply channel L8, a hot water outlet channel L9, a hot water circulation channel L7, a circulation pump 44, etc. The hot water storage tank 45 stores hot water as a heat transfer medium. The hot water circulation channel L7 circulates hot water between the hot water storage tank 45 and the waste heat recovery heat exchanger 34. In the hot water storage tank 45, hot water is stored in a state that forms a temperature stratification, with relatively low-temperature hot water stored at the bottom and relatively high-temperature hot water stored at the top. The hot water circulation channel L7 has a forward path L7a through which hot water flows from the hot water storage tank 45 to the waste heat recovery heat exchanger 34, and a return path L7b through which hot water flows from the waste heat recovery heat exchanger 34 to the hot water storage tank 45. A circulation pump 44 is provided along the outbound path L7a to circulate hot water in the hot water circulation path L7. A recovered hot water temperature measuring device T5 is provided along the return path L7b to measure the temperature of the hot water supplied from the heat recovery heat exchanger 34 to the hot water storage tank 45.

[0053] In this configuration, the hot water supplied from the bottom of the hot water storage tank 45 to the heat recovery heat exchanger 34 via the forward path L7a of the hot water circulation path L7 is heated in the heat recovery heat exchanger 34, and the heated hot water is supplied to the top of the hot water storage tank 45 via the return path L7b of the hot water circulation path L7. A recovered hot water temperature measuring device T5 is provided in the middle of the return path L7b to measure the temperature of the hot water being transferred from the heat recovery heat exchanger 34 to the hot water storage tank 45. In this embodiment, the fuel cell control unit 49 increases or decreases the output of the circulation pump 44, for example, the duty cycle of the PWM control of the circulation pump 44, so that the temperature of the hot water flowing through the return path L7b and into the hot water storage tank 45 (the temperature of the hot water measured by the recovered hot water temperature measuring device T5) reaches a predetermined target hot water storage temperature (for example, 65°C). The fuel cell control unit 49 can also obtain information on the rotational speed of the circulation pump 44 at that time. In this way, hot water is stored in the hot water storage tank 45, forming a temperature stratification, i.e., heat is accumulated.

[0054] When the circulation of hot and cold water by the circulation pump 44 is functioning normally, the correlation between the output of the circulation pump 44 and its rotational speed will only show a deviation of less than a standard value. For example, if a standard rotational speed (200 rpm) is determined for each output of the circulation pump 44 (e.g., 30%), then if the circulation of hot and cold water by the circulation pump 44 is functioning normally, the actual rotational speed will only deviate from the standard rotational speed by less than a standard value (e.g., less than ±30%). The fuel cell control unit 49 can obtain information on the output and rotational speed of the circulation pump 44.

[0055] In addition, the fuel cell device 10 is equipped with a radiator 56 that cools the hot water flowing in the forward path L7a by circulating the air present in the space 48 inside the outer container 11. Specifically, the radiator 56 is installed in the middle of the forward path L7a of the hot water circulation path L7, and cools the hot water flowing in the forward path L7a by rotating a radiator fan 56a to circulate the air present inside the outer container 11.

[0056] Furthermore, the fuel cell device 10 includes a first hot water temperature measuring device T6 that measures the temperature of the hot water flowing between the radiator 56 and the heat exchanger 34 for waste heat recovery, in the middle of the forward path L7a of the hot water circulation path L7, and a second hot water temperature measuring device T7 that measures the temperature of the hot water flowing between the hot water storage tank 45 and the radiator 56, in the middle of the forward path L7a of the hot water circulation path L7.

[0057] The fuel cell control unit 49 rotates the radiator fan 56a of the radiator 56 when the temperature of the hot water measured by the second hot water temperature measuring device T7 is equal to or greater than the set heat transfer medium temperature. For example, if the temperature of the hot water measured by the second hot water temperature measuring device T7 is equal to or greater than the upper limit heat transfer medium temperature, the fuel cell control unit 49 increases or decreases the output of the radiator fan 56a of the radiator 56, for example, the duty cycle of the PWM control, so that the temperature of the hot water measured by the first hot water temperature measuring device T6 is equal to or less than the target heat transfer medium temperature which is lower than the upper limit heat transfer medium temperature mentioned above.

[0058] When the radiator fan 56a is operating normally, the correlation between the output of the radiator fan 56a and its rotational speed will only show a deviation of less than a reference value. For example, if a standard rotational speed (200 rpm) is determined for each output of the radiator fan 56a (e.g., 30%), then when the radiator fan 56a is operating normally, the actual rotational speed will only deviate from the standard rotational speed by less than a reference value (e.g., less than ±30%). The fuel cell control unit 49 can obtain information on the output and rotational speed of the radiator fan 56a.

[0059] A water supply channel L8 for supplying tap water to the hot water storage tank 45 is connected to the lower part of the hot water storage tank 45, and a hot water outlet channel L9 for discharging the hot water stored in the hot water storage tank 45 is connected to the upper part of the hot water storage tank 45. The hot water stored in the hot water storage tank 45 is subjected to the water supply pressure applied inside the water supply channel L8. With this configuration, in the hot water storage tank 45, for example, when a faucet (not shown) connected to the hot water outlet channel L9 is opened, hot water is discharged from the hot water storage tank 45 to the hot water outlet channel L9, and tap water is supplied to the hot water storage tank 45 from the water supply channel L8.

[0060] The fuel cell device 10 includes a power conversion circuit unit 46 in the inner space 48 of the outer container 11 that converts the output power of the cell stack 18 into desired AC power and supplies that AC power to a single-phase three-wire power line 8 connected to the power grid 63. The power line 8 has a first voltage line, a second voltage line, and a neutral line. The fuel cell device 10 also includes a circuit temperature measuring instrument T11 in the inner space 48 of the outer container 11 that measures the temperature of the power conversion circuit unit 46, and a cooling fan 47 that air-cools the power conversion circuit unit 46 by circulating the air in the inner space 48 of the outer container 11. In addition, the fuel cell device 10 includes an output current measuring instrument 52 that measures the output current of the cell stack 18, and an output voltage measuring instrument 53 that measures the output voltage of the cell stack 18.

[0061] The fuel cell device 10 includes a fuel cell control unit 49 as a control device for controlling the operation of the fuel cell device 10, a storage unit 50 for storing information handled by the fuel cell device 10, and a communication unit 51. Measurement results from various measuring instruments equipped with the fuel cell device 10, the operating status of the equipment, etc., are transmitted to the fuel cell control unit 49 via signal transmission lines (not shown), etc., and the measurement results are stored in the storage unit 50. The fuel cell control unit 49 then transmits these measurement results and operating status from the communication unit 51 to the abnormality diagnosis device 4 at a predetermined timing. In addition, the fuel cell control unit 49 also transmits abnormalities that appear in these measurement results and operating status as part of the measurement results and operating status from the communication unit 51 to the abnormality diagnosis device 4.

[0062] The fuel cell control unit 49 controls the operation of various devices such as the igniter 20, shut-off valve 26, raw fuel blower 30, reforming water pump 39, air blower 41, circulation pump 44, power conversion circuit unit 46, cooling fan 47, radiator 56, and ventilation fan 59.

[0063] As shown in Figure 3, the power line 8 installed at facility 1 is connected to the power system 63. The fuel cell device 10 and the power consumption device 5 are connected to the power line 8. In the fuel cell device 10, the power conversion circuit unit 46 is electrically connected to the cell stack 18 by a connecting line 64, electrically connected to the power line 8 by a connecting line 65, and electrically connected to the DC auxiliary equipment 58 by a power supply line 66. The DC auxiliary equipment 58 is equipment mounted on the fuel cell device 10 that operates on DC power, and includes, for example, the fuel cell control unit 49, the raw fuel blower 30, the air blower 41, and the reforming water pump 39.

[0064] The grid voltage meter 69 measures the voltage of the power supplied from the power system 63 to the power line 8 (grid voltage), and the measurement result is transmitted to the fuel cell device 10.

[0065] With this configuration, the power conversion circuit 46 can convert the power generated by the cell stack 18 into desired AC power and output the converted power to the power line 8 connected to the power system 63. It can also convert the power generated by the cell stack 18 and the power supplied from the power line 8 into DC power of a target auxiliary voltage (e.g., 24V) and supply it to the DC auxiliary equipment 58.

[0066] Furthermore, a thermal fuse 57 is provided in the middle of the power supply line 66. The thermal fuse 57 is provided in the middle of the power supply line 66 from the power conversion circuit section 46 to the fuel cell control section 49, which acts as a control device, and is configured to electrically disconnect the power supply line 66 when the temperature of the hot water supplied from the heat recovery heat exchanger 34 to the hot water storage tank 45 reaches a predetermined high temperature. As shown in Figure 2, the thermal fuse 57 is implemented using, for example, a bimetal that becomes insulated when the temperature of the hot water flowing in the return path L7b of the hot water circulation path L7 (i.e., the temperature of the hot water supplied from the heat recovery heat exchanger 34 to the hot water storage tank 45) exceeds a set temperature.

[0067] Next, a method will be described in which the abnormality diagnosis device 4 diagnoses the nature of an abnormality occurring in the fuel cell device 10 based on information received from the fuel cell device 10 installed in facility 1 via the information communication line 2. The abnormality diagnosis device 4 comprises a storage unit 4a and a diagnosis processing unit 4b.

[0068] The memory unit 4a of the abnormality diagnosis device 4 stores, for each of several abnormalities, an abnormality that appears in the measurement result of at least one of the multiple measuring instruments of the fuel cell device 10 and the operating state of the fuel cell device 10, and an abnormality diagnosis process for identifying one of several possible diagnosis results for that abnormality, which includes at least one cause of the abnormality and a method of dealing with the abnormality. Specifically, the abnormality diagnosis process is composed of a combination of multiple determination processes that determine whether at least one of the measurement results of the measuring instruments of the fuel cell device 10, the operating state of the equipment, and the operating environment of the fuel cell device 10 satisfies predetermined determination conditions. The determination result of the determination process, which is determined depending on whether the determination conditions are met, includes at least one of the following: a case instructing a transition to another determination process, and a case leading to the identification of a diagnosis result of the abnormality diagnosis process.

[0069] The measurement results of the measuring instruments of the fuel cell device 10 described above include, for example, the measurement results of various measuring instruments such as temperature measuring instruments T1 to T11, pressure measuring instrument 27, raw fuel flow rate measuring instrument 28, air flow rate measuring instrument 42, gas measuring instrument 43, output current measuring instrument 52, output voltage measuring instrument 53, and grid voltage measuring instrument 69. Although not shown in the figures, if the power conversion circuit unit 46 is equipped with a measuring instrument that measures the voltage of the DC power supplied to the DC auxiliary equipment 58 such as the control device (fuel cell control unit 49) (in Figure 3, the voltage of the power supply line 66 between the power conversion circuit unit 46 and the thermal fuse 57), then that measurement value is also one of the measurement results of the measuring instruments of the fuel cell device 10. Furthermore, if the fuel cell control unit 49 is equipped with a measuring instrument that measures the voltage of the DC power supplied from the power supply line 66 (in Figure 3, the voltage of the power supply line 66 between the thermal fuse 57 and the DC auxiliary equipment 58), then that measurement value is also one of the measurement results of the measuring instruments of the fuel cell device 10.

[0070] The operating status of the above-mentioned equipment includes, for example, whether the equipment is operating normally, whether an alarm has been issued, what the actual operating status of the equipment is (for example, what values ​​the output, target flow rate, target rotational speed, and actual rotational speed of the raw fuel blower 30, reforming water pump 39, air blower 41, circulation pump 44, cooling fan 47, radiator 56, ventilation fan 59, etc. are, whether the igniter 20 is operating, etc.), and what process the fuel cell system 10 is currently performing, such as the start-up process, power generation process, or shutdown process.

[0071] The operating environment of the fuel cell device 10 described above includes, for example, the state of the power grid 63 connected to the fuel cell device 10 (e.g., whether or not there is a power outage), whether or not the grid is disconnected, the length of the grid disconnection, the supply status of raw materials to the fuel cell device 10, the actual amount of heat (gas type) of raw materials being supplied, and the amount of heat of raw materials intended for use in the fuel cell device 10. Information on the state of the power grid 63 connected to the fuel cell device 10 (e.g., whether or not there is a power outage) may be provided by the information provision server device 3.

[0072] Then, when an abnormality occurs in the measurement results, operating state, or operating environment received from the fuel cell device 10 via the information communication line 2, the diagnostic processing unit 4b of the abnormality diagnosis device 4 identifies a diagnosis result for the abnormality based on the contents of the abnormality diagnosis process corresponding to the abnormality stored in the storage unit 4a, and at least one of the measurement results of the measuring instruments of the fuel cell device 10, the operating state of the equipment, and the operating environment of the fuel cell device 10. Here, whether or not the above abnormality occurs may be determined by the fuel cell device 10 or by the abnormality diagnosis device 4.

[0073] [Anomaly Diagnosis Processing] Figure 4 is a flowchart showing the details of the abnormality diagnosis process performed by the diagnostic processing unit 4b when an abnormality such as a low voltage anomaly occurs in the power supply line 66. DC power is supplied to the DC auxiliary equipment 58 of the fuel cell device 10 from the power conversion circuit unit 46 via the power supply line 66. The power conversion circuit unit 46 then supplies DC power adjusted to a target auxiliary voltage (e.g., 24V) to the various DC auxiliary equipment 58, including the fuel cell control unit 49. For example, the fuel cell control unit 49 monitors the voltage of the DC power supplied by the power conversion circuit unit 46 to the DC auxiliary equipment 58. If the voltage of the DC power supplied by the power conversion circuit unit 46 to the DC auxiliary equipment 58 is below a predetermined voltage (e.g., 21V), the fuel cell control unit 49 determines that the first determination condition, that the voltage of the DC power supplied by the power conversion circuit unit 46 to the DC auxiliary equipment 58 is in a predetermined low voltage state, is met, that is, an abnormality of low voltage in the power supply line 66 has occurred.

[0074] The fuel cell control unit 49 then transmits the measurement result, indicating that an abnormality of low voltage in the power supply line 66 has occurred, from the communication unit 51 to the abnormality diagnosis device 4. Alternatively, the diagnosis processing unit 4b of the abnormality diagnosis device 4 may refer to the information received from the fuel cell device 10 via the information communication line 2 to determine whether the first determination condition, that a low voltage abnormality in the power supply line 66 has occurred, is met.

[0075] When the abnormality diagnosis device 4 receives notification of a measurement result indicating that an abnormality such as a low voltage abnormality in the power supply line 66 has occurred, or when the diagnostic processing unit 4b determines that an abnormality such as a low voltage abnormality in the power supply line 66 has occurred, it refers to the information stored in the memory unit 4a and reads out the corresponding abnormality diagnosis process. The diagnostic processing unit 4b then executes that abnormality diagnosis process. The abnormality diagnosis process in this embodiment is composed of a combination of the determination processes of steps #10 to #20 shown in Figure 4.

[0076] In step #10, the diagnostic processing unit 4b determines whether the second determination condition is met, which is that the first determination condition has been met a set number of times (e.g., 3 times) within a predetermined period in the past (e.g., within 10 hours). If the second determination condition is met, the diagnostic processing unit 4b proceeds to step #11; otherwise, it proceeds to step #13.

[0077] In step #11, the diagnostic processing unit 4b determines whether the third determination condition is met, which is that the system voltage in the power system 63, as measured by the system voltage measuring instrument 69, is within the normal range. If the third determination condition is not met, the diagnostic processing unit 4b arrives at diagnosis result A1, which indicates that an abnormality (system abnormality) has occurred in the power system 63. In other words, the diagnostic processing unit 4b determines that an abnormality has occurred in the power system 63 if the first determination condition is met, which is that the voltage of the DC power supplied by the power conversion circuit unit 46 to the DC auxiliary equipment 58 is in a predetermined low voltage state, and the second determination condition is met, which is that the first determination condition has been met a set number of times within a predetermined period in the past, and the third determination condition is not met, which is that the system voltage in the power system 63 is within the normal range. In other words, the diagnosis result is that the abnormality in the power system 63 has resulted in the low voltage abnormality of the power supply line 66 described above. Thus, the determination result of the determination process in step #11 includes cases where the diagnosis result of the abnormality diagnosis process is identified.

[0078] If the diagnostic processing unit 4b determines that the third determination condition is met in process #11, it proceeds to process #12. Thus, the determination result of the determination process in process #11 includes cases where a transition to another determination process is instructed.

[0079] In step #12, the diagnostic processing unit 4b determines whether the fourth determination condition is met, which is that the voltage of the DC power supplied by the power conversion circuit unit 46 to the DC auxiliary equipment 58 is within a set range including zero.

[0080] Then, if the fourth determination condition is not met, the diagnostic processing unit 4b arrives at diagnosis result A2, which indicates that an abnormality has occurred in the power conversion circuit unit 46. In other words, if the first determination condition is met, the second determination condition is met, the third determination condition is met, and the fourth determination condition, which is that the voltage of the DC power supplied by the power conversion circuit unit 46 to the DC auxiliary equipment 58 is within a set range including zero, is not met, the diagnostic processing unit 4b determines that an abnormality has occurred in the power conversion circuit unit 46. In other words, the diagnosis result is that the low voltage abnormality in the power supply line 66 described above has occurred due to an abnormality in the power conversion circuit unit 46. Thus, the determination result of the determination process in step #12 includes cases where the diagnosis result of the abnormality diagnosis process is identified.

[0081] The content of diagnostic result A2 is not limited to what is described above; for example, it may be a diagnostic result such as "replacement of power conversion circuit unit 46" or a diagnostic result such as "repair of power conversion circuit unit 46." In addition, although several examples of diagnostic result A2 are listed, they may be used alone or in combination with any of the others.

[0082] In response, the diagnostic processing unit 4b arrives at diagnostic result A3, which indicates that the thermal fuse 57 has severed the power supply line 66, if the fourth determination condition is met. In other words, the diagnostic processing unit 4b determines that the thermal fuse 57 has severed the power supply line 66 if the first determination condition is met, the second determination condition is met, the third determination condition is met, and the fourth determination condition is met, which is that the voltage of the DC power supplied by the power conversion circuit unit 46 to the DC auxiliary equipment 58 is within a set range including zero. In other words, the diagnostic result indicates that the thermal fuse 57 has severed the power supply line 66, resulting in the aforementioned low-voltage abnormality of the power supply line 66. Thus, the determination result of the determination process in step #12 includes cases where the diagnosis result of the abnormality diagnosis process is identified.

[0083] The content of diagnostic result A3 is not limited to what is described above; for example, it could be a diagnostic result such as "Replace thermal fuse 57" or "Repair thermal fuse 57." Furthermore, although several examples of diagnostic result A3 are provided, they may be used individually or in combination with any of the others.

[0084] In step #13, the diagnostic processing unit 4b determines whether the fifth determination condition is met, which is that it has obtained the measurement data of the measuring instrument when the first determination condition is met, namely the system voltage in the power system 63, the temperature of the hot water supplied from the heat recovery heat exchanger 34 to the hot water storage tank 45, and the output voltage of the cell stack 18. If the above measurement data has been obtained, the diagnostic processing unit 4b proceeds to step #16 and performs an abnormality diagnosis by referring to the measurement data, and if the above measurement data has not been obtained, it proceeds to step #14 and performs an abnormality diagnosis without referring to the measurement data.

[0085] In step #14, the diagnostic processing unit 4b determines whether the sixth determination condition, that the low voltage state occurred while the cell stack 18 was stopped generating power, is met.

[0086] Then, in step #14, if the sixth determination condition, that the low voltage state occurred while the cell stack 18 was stopped generating power, is met, the diagnostic processing unit 4b arrives at diagnosis result A4, which indicates that the thermal fuse 57 has severed the power supply line 66, or that an abnormality has occurred in the power conversion circuit unit 46. In other words, if the first determination condition is met, the second determination condition is not met, the fifth determination condition, that the above measurement data when the first determination condition was met has been acquired, is not met, and the sixth determination condition, that the low voltage state occurred while the cell stack 18 was stopped generating power, is not met, the diagnostic processing unit 4b determines that the thermal fuse 57 has severed the power supply line 66, or that an abnormality has occurred in the power conversion circuit unit 46. In other words, the diagnostic result indicates that the low voltage abnormality of the power supply line 66 described above has occurred because the thermal fuse 57 has severed the power supply line 66, or an abnormality has occurred in the power conversion circuit unit 46. Thus, the judgment result of the judgment process in step #14 includes cases where it leads to the identification of the diagnosis result of the anomaly diagnosis process.

[0087] The content of diagnostic result A4 is not limited to what is described above. For example, it may be a diagnostic result such as "Replacement of thermal fuse 57 or power conversion circuit unit 46" or "Repair of thermal fuse 57 or power conversion circuit unit 46." In addition, although several examples of diagnostic result A4 are provided, they may be used alone or in combination with any of the others.

[0088] In response to this, in step #14, the diagnostic processing unit 4b proceeds to step #15 if the sixth determination condition is met, and determines whether the seventh determination condition is met, which is that the temperature of the hot water after heat exchange with exhaust gas in the heat recovery heat exchanger 34, as measured by the recovered hot water temperature measuring instrument T5, is at a predetermined high temperature (for example, above a predetermined temperature).

[0089] Then, if the seventh determination condition is not met, the diagnostic processing unit 4b arrives at diagnosis result A5, which indicates that an abnormality has occurred in the hot module 13. In other words, the diagnostic processing unit 4b determines that an abnormality has occurred in the hot module 13 if the first determination condition is met, the second determination condition is not met, the fifth determination condition is not met, the sixth determination condition is met, and the seventh determination condition, which states that the temperature of the hot water after heat exchange with the exhaust gas is at a predetermined high temperature, is not met. In other words, the diagnosis result is that the abnormality in the hot module 13 is causing the low voltage abnormality in the power supply line 66 described above. Thus, the determination result of the determination process in step #15 includes cases where the diagnosis result of the abnormality diagnosis process is identified.

[0090] The content of diagnostic result A5 is not limited to what is described above; for example, it could be a diagnostic result such as "replace hot module 13" or "repair hot module 13." Furthermore, while several examples of diagnostic result A5 are provided, they may be used individually or in combination with any of the others.

[0091] In response, the diagnostic processing unit 4b determines that if the seventh determination condition is met, there is an abnormality in the heat recovery system, which recovers heat from exhaust gas in the heat recovery heat exchanger 34 and returns the hot water supplied from the hot water storage tank 45 to the hot water storage tank 45. In other words, if the first determination condition is met, the second determination condition is not met, the fifth determination condition is not met, the sixth determination condition is met, and the seventh determination condition is met, which states that the temperature of the hot water after heat exchange with exhaust gas in the heat recovery heat exchanger 34 is at a predetermined high temperature, then the diagnostic processing unit 4b determines that there is an abnormality in the heat recovery system (i.e., the heat recovery system as a system for recovering heat generated in the fuel cell device 10) that recovers heat from exhaust gas in the heat recovery heat exchanger 34 and returns the hot water supplied from the hot water storage tank 45 to the hot water storage tank 45. In other words, the diagnosis is that an abnormality has occurred in the heat recovery system, resulting in the low voltage abnormality in the power supply line 66 mentioned above. Thus, the judgment result of the judgment process in step #15 includes cases where the result of the abnormality diagnosis process is identified.

[0092] The content of diagnostic result A6 is not limited to what is described above; for example, it may be a diagnostic result such as "replacement of the heat recovery system" or "repair of the heat recovery system." Furthermore, although several examples of diagnostic result A6 are provided, they may be used individually or in combination with any of the others.

[0093] In step #16, the diagnostic processing unit 4b determines whether the eighth determination condition is met, which is that the system voltage in the power system 63, measured by the system voltage measuring instrument 69, is within the normal range (for example, within a predetermined voltage range). If the eighth determination condition is not met, the diagnostic processing unit 4b arrives at diagnosis result A7, which indicates that an abnormality has occurred in the power system 63. In other words, the diagnostic processing unit 4b determines that an abnormality has occurred in the power system 63 if the first determination condition is met, the second determination condition is not met, the fifth determination condition is met (that the above measurement data has been acquired when the first determination condition was met), and the eighth determination condition (that the system voltage in the power system 63 is within the normal range) is not met. In other words, the diagnosis result is that the low voltage abnormality in the power supply line 66 described above has occurred because an abnormality has occurred in the power system 63. Thus, the determination result of the determination process in step #16 includes cases where the diagnosis result of the abnormality diagnosis process is identified.

[0094] If the diagnostic processing unit 4b determines in step #16 that the eighth determination condition is met, that is, that the system voltage in the power system 63 is within the normal range, it proceeds to step #17 to determine whether the ninth determination condition, that a low voltage state occurred while the cell stack 18 was stopped generating power, is met. If the ninth determination condition is met, the diagnostic processing unit 4b proceeds to step #20; otherwise, it proceeds to step #18.

[0095] In step #18, the diagnostic processing unit 4b determines whether the tenth determination condition is met, which is that the temperature of the hot water after heat exchange with the exhaust gas in the heat recovery heat exchanger 34, as measured by the recovered hot water temperature measuring instrument T5, is in a predetermined high-temperature state (for example, 90°C or higher). If the tenth determination condition is met, the diagnostic processing unit 4b arrives at diagnosis result A8, which indicates that an abnormality has occurred in the heat recovery system in which the hot water supplied from the hot water storage tank 45 recovers heat from the exhaust gas in the heat recovery heat exchanger 34 and returns to the hot water storage tank 45. In other words, the diagnostic processing unit 4b determines that an abnormality has occurred in the heat recovery system where hot water supplied from the hot water storage tank 45 recovers heat from the exhaust gas in the heat recovery heat exchanger 34 and returns to the hot water storage tank 45, if the first determination condition is met, the second determination condition is not met, the fifth determination condition is met (that the above measurement data has been acquired when the first determination condition was met), the eighth determination condition is met (that the system voltage in the power system 63 is within the normal range), the ninth determination condition is not met (that a low voltage state occurred while the cell stack 18 was stopped generating power), and the tenth determination condition is met (that the temperature of the hot water after heat exchange with the exhaust gas in the heat recovery heat exchanger 34 is at a predetermined high temperature). In other words, the diagnostic processing unit 4b determines that an abnormality has occurred in the heat recovery system where hot water supplied from the hot water storage tank 45 recovers heat from the exhaust gas in the heat recovery heat exchanger 34 and returns to the hot water storage tank 45.

[0096] The content of diagnostic result A8 is not limited to what is described above; for example, it may be a diagnostic result such as "replacement of the heat recovery system" or "repair of the heat recovery system." Furthermore, although several examples of diagnostic result A8 are provided, they may be used individually or in combination with any of the others.

[0097] If the 10th determination condition is not met, the diagnostic processing unit 4b proceeds to step #19 to determine whether the 11th determination condition, which is that the output voltage of the cell stack 18 measured by the output voltage measuring instrument 53 is above a predetermined value (i.e., at the appropriate voltage), is met. If the 11th determination condition is not met, the diagnostic processing unit 4b arrives at diagnosis result A9, which indicates that an abnormality has occurred in the hot module 13. In other words, the diagnostic processing unit 4b determines that an abnormality has occurred in the hot module 13 if the 1st determination condition is met, the 2nd determination condition is not met, the 5th determination condition is met, the 8th determination condition is met, which is that the system voltage in the power system 63 is within the normal range, the 9th determination condition is not met, which is that a low voltage state occurred while the cell stack 18 was not generating power, the 10th determination condition is not met, which is that the temperature of the hot water after heat exchange with the exhaust gas in the heat recovery heat exchanger 34 is at a predetermined high temperature, and the 11th determination condition is not met, which is that the output voltage of the cell stack 18 is above a predetermined value. In other words, the diagnosis is that an abnormality has occurred in the hot module 13, resulting in the low voltage abnormality in the power supply line 66 described above. Thus, the judgment result of the judgment process in step #19 includes cases where the result of the abnormality diagnosis process is identified.

[0098] The content of diagnostic result A9 is not limited to what is described above; for example, it could be a diagnostic result such as "replace hot module 13" or "repair hot module 13." Furthermore, although several examples of diagnostic result A9 are provided, they may be used individually or in combination with any of the others.

[0099] If the 11th determination condition is met, the diagnostic processing unit 4b proceeds to step #20 to determine whether the 12th determination condition is met, which is that the voltage of the DC power supplied by the power conversion circuit unit 46 to the DC auxiliary equipment 58 is within a set range including zero. If the 12th determination condition is not met, the diagnostic processing unit 4b arrives at diagnosis result A10, which indicates that an abnormality has occurred in the power conversion circuit unit 46. In other words, the diagnostic processing unit 4b determines that an abnormality has occurred in the power conversion circuit unit 46 if the 1st determination condition is met, the 2nd determination condition is not met, the 5th determination condition is met, the 8th determination condition is met, the 9th determination condition is not met, the 10th determination condition is not met, the 11th determination condition is met, which is that the output voltage of the cell stack 18 is above a predetermined value, and the 12th determination condition is not met, which is that the voltage of the DC power supplied by the power conversion circuit unit 46 to the DC auxiliary equipment 58 is within a set range including zero. In other words, the diagnosis is that an abnormality has occurred in the power conversion circuit section 46, resulting in the low voltage abnormality in the power supply line 66 described above. Thus, the judgment result of the judgment process in step #20 includes cases where the result of the abnormality diagnosis process is identified.

[0100] The content of diagnostic result A10 is not limited to what is described above; for example, it may be a diagnostic result such as "replacement of power conversion circuit unit 46" or a diagnostic result such as "repair of power conversion circuit unit 46." Furthermore, although several examples of diagnostic result A10 are provided, they may be used individually or in combination with any of the others.

[0101] In response, the diagnostic processing unit 4b arrives at diagnosis result A11, which indicates an abnormality in the thermal fuse 57 (for example, the thermal fuse 57 has severed the power supply line 66), if the 12th determination condition is met. In other words, the diagnostic processing unit 4b determines that there is an abnormality in the thermal fuse 57 if the 1st determination condition is met, the 2nd determination condition is not met, the 5th determination condition is met, the 8th determination condition is met, the 9th determination condition is not met, the 10th determination condition is not met, the 11th determination condition is met, which is that the output voltage of the cell stack 18 is above a predetermined value, and the 12th determination condition is met, which is that the voltage of the DC power supplied by the power conversion circuit unit 46 to the DC auxiliary equipment 58 is within a set range including zero. In other words, the diagnostic result indicates that the low voltage abnormality of the power supply line 66 described above has occurred due to an abnormality such as the thermal fuse 57 severing the power supply line 66. Thus, the judgment result of the judgment process in step #20 includes cases where it leads to the identification of the diagnosis result of the anomaly diagnosis process.

[0102] The content of diagnostic result A11 is not limited to what is described above; for example, it could be a diagnostic result such as "Replace thermal fuse 57" or "Repair thermal fuse 57." Furthermore, although several examples of diagnostic result A11 are provided, they may be used individually or in combination with any of the others.

[0103] As described above, the abnormality diagnosis device 4 can automatically perform the process from the occurrence of an abnormality to the identification of a diagnosis result for that abnormality according to a pre-created abnormality diagnosis process procedure. The identified diagnosis result is then stored in the memory unit 4a of the abnormality diagnosis device 4. The memory unit 4a of the abnormality diagnosis device 4 also stores at least one of the contact details of the administrator, such as the owner who manages the fuel cell device 10, the maintenance personnel for the fuel cell device 10, and the manufacturing personnel, such as the assemblers and parts manufacturers of the fuel cell device 10. The diagnosis processing unit 4b outputs the identified diagnosis result to at least one of the administrator's contact details, the maintenance personnel's contact details, and the manufacturing personnel's contact details. For example, the diagnosis processing unit 4b sends the diagnosis result to the email address of the administrator of the fuel cell device 10, the email address of the maintenance personnel for the fuel cell device 10, and the email address of the manufacturing personnel for the fuel cell device 10. As a result, the administrator of the fuel cell device 10 can check the diagnosis result on their administrator terminal device 62, the maintenance personnel for the fuel cell device 10 can check the diagnosis result on their maintenance personnel terminal device 60, and the manufacturing personnel for the fuel cell device 10 can check the diagnosis result on their manufacturing personnel terminal device 61. In this way, the abnormality diagnosis device 4 automatically identifies the diagnosis result for the abnormality, allowing maintenance personnel to prepare in advance according to the diagnosis result before being dispatched.

[0104] For example, if the manager, maintenance personnel, and manufacturing personnel of the fuel cell unit 10 know the nature of the malfunction occurring in a specific part of the fuel cell unit 10 as the cause of the abnormality, they can determine the necessary work, such as repairing or replacing parts in that part. Furthermore, before arriving at the site for repairs to the fuel cell unit 10, the maintenance personnel of the fuel cell unit 10 can prepare for repairs based on the diagnostic results, and the manufacturing personnel of the fuel cell unit 10 can prepare the parts necessary for repairs based on the diagnostic results. As a result, problems such as the lack of personnel with the necessary repair skills or the failure to bring the necessary parts to the site can be avoided.

[0105] Furthermore, the diagnostic results are not limited to the examples described above and can be modified as appropriate. To give a specific example, the diagnostic result may include instructions for replacing or repairing components of the fuel cell device 10 related to the diagnostic result, as a way to address the abnormality.

[0106] If the response to an abnormality includes instructions for replacing or repairing the components of the fuel cell device 10 as described above, it is possible to prepare the replacement components in advance and to determine the personnel required for the replacement or repair work in advance.

[0107] Furthermore, when issuing instructions to replace or repair a specific component of the fuel cell device 10, it is preferable to know the difficulty level of the work. For this reason, the memory unit 4a stores information indicating the difficulty level of the repair or replacement work for each component of the fuel cell device 10, and the diagnostic result may include information indicating the difficulty level as a way to deal with the abnormality. If information indicating the difficulty level of the repair or replacement work for a component is included as a way to deal with the abnormality, preparations can be made in advance to dispatch personnel with the appropriate skills for that difficulty level.

[0108] In addition, when issuing instructions to replace or repair a specific component of the fuel cell device 10, it is preferable for the maintenance personnel who actually perform the replacement or repair to be able to view video data explaining the repair or replacement work in advance or on-site. For this reason, the storage unit 4a stores video data explaining the repair or replacement work for each component of the fuel cell device 10, and the diagnostic results may include video data as a way to deal with the abnormality. If video data explaining the repair or replacement work for the components of the fuel cell device 10 is included as a way to deal with the abnormality, the person in charge of repairing or replacing the component can check the video data and reliably perform the repair or replacement work.

[0109] <Another Embodiment> In the above embodiment, the configuration of the fuel cell device 10 was specifically described, but its configuration can be changed as appropriate. Furthermore, the content of the diagnostic results can be changed as needed.

[0110] In the above embodiment, the abnormality diagnosis device 4 of the present invention was described with numerical examples, but these numerical values ​​are provided for illustrative purposes only and can be changed as appropriate.

[0111] The configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. Furthermore, the embodiments disclosed herein are illustrative, and the embodiments of the present invention are not limited thereto and can be modified as appropriate without departing from the purpose of the present invention. [Industrial applicability]

[0112] This invention can be used in an abnormality diagnosis device that can appropriately diagnose the nature of abnormalities occurring in a fuel cell device. [Explanation of Symbols]

[0113] 1: Facility 2: Information and communication lines 4: Anomaly detection device 7: Interior space 8: Power lines 10:Fuel cell device 11:Outer container 12:Inner container 13: Hot Module 14: Vaporizer 15: Modifier 17: Fuel cell 18: Cell Stack 19: Combustion section 34: Heat exchanger for waste heat recovery 45: Hot water storage tank 46: Power Conversion Circuit Section 48: Space inside the outer container 49: Fuel cell control unit (control device) 57: Thermal fuse 58: DC auxiliary equipment 63: Power system 66:Power line 69: System voltage measuring instrument

Claims

1. An abnormality diagnosis device that diagnoses the nature of an abnormality occurring in a fuel cell device based on information received from the fuel cell device installed in the facility via an information and communication line, The fuel cell device comprises an outer container and a hot module having an inner container provided in the space inside the outer container, The hot module has, in the inner space inside the inner container, a vaporizer for vaporizing the supplied reforming water, a reformer for steam reforming raw fuel using steam supplied from the vaporizer to produce fuel gas, a cell stack having a plurality of fuel cell cells that generate electricity using the fuel gas produced in the reformer, and a combustion unit for burning off-gas discharged from the cell stack. The fuel cell device comprises a power conversion circuit that can convert the power generated by the cell stack into desired AC power and output the converted power to a power line connected to the power grid, and can convert the power generated by the cell stack and the power supplied from the power line into DC power of a target auxiliary voltage and supply it to a DC auxiliary device, a grid voltage measuring instrument that measures the grid voltage of the power supplied from the power grid to the power line, and a control device that controls the operation of the fuel cell device. An abnormality diagnostic device that determines that an abnormality has occurred in the power system if a first determination condition is met, that the voltage of the DC power supplied by the power conversion circuit to the DC auxiliary equipment is in a predetermined low voltage state, and a second determination condition is met, that the first determination condition has been met a set number of times within a predetermined period in the past, and a third determination condition is not met, that the system voltage in the power system measured by the system voltage measuring instrument is within the normal range.

2. An abnormality diagnosis device according to claim 1, which determines that an abnormality has occurred in the power conversion circuit if the first determination condition is met, the second determination condition is met, the third determination condition is met, and the fourth determination condition, which is that the voltage of the DC power supplied by the power conversion circuit to the DC auxiliary equipment is within a set range including zero, is not met.

3. The fuel cell device includes a hot water storage tank for storing hot water, a heat exchanger for heat recovery that exchanges heat between the hot water and exhaust gas, which is discharged to the outside of the inner container and contains gas generated by combustion in the combustion section, and a thermal fuse provided in the middle of the power supply line from the power conversion circuit to the control device, which cuts the power supply line when the temperature of the hot water supplied from the heat recovery heat exchanger to the hot water storage tank reaches a predetermined high temperature. An abnormality diagnosis device according to claim 1 or 2, which determines that the thermal fuse has cut the power supply line if the first determination condition is met, the second determination condition is met, the third determination condition is met, and the fourth determination condition is met, in which case it is determined that the thermal fuse has cut the power supply line.

4. The fuel cell device comprises a hot water storage tank for storing hot water, a heat exchanger for heat recovery that exchanges heat between the hot water and exhaust gas, which is discharged to the outside of the inner container and contains gas generated by combustion in the combustion section, and a thermal fuse provided in the middle of the power supply line from the power conversion circuit to the control device, which cuts the power supply line when the temperature of the hot water supplied from the heat recovery heat exchanger to the hot water storage tank reaches a predetermined high temperature. An abnormality diagnosis device according to claim 1, wherein if the first determination condition is met, the second determination condition is not met, and the fifth determination condition, which is that the system voltage in the power system, the temperature of the hot water supplied from the heat recovery heat exchanger to the hot water storage tank and the output voltage of the cell stack are obtained when the first determination condition is met, is not met, and the sixth determination condition, which is that the low voltage state occurred while the power generation of the cell stack was stopped, is not met, then it is determined that the thermal fuse has cut the power supply line or that an abnormality has occurred in the power conversion circuit.

5. An abnormality diagnosis device according to claim 4, which determines that an abnormality has occurred in the hot module if the first determination condition is met, the second determination condition is not met, the fifth determination condition is not met, the sixth determination condition is met, and the seventh determination condition, which states that the temperature of the hot water after heat exchange with the exhaust gas is in a predetermined high-temperature state, is not met.

6. An abnormality diagnosis device according to claim 4 or 5, which determines that an abnormality has occurred in the heat recovery system in which the hot water supplied from the hot water storage tank recovers heat from the exhaust gas in the heat recovery heat exchanger and returns to the hot water storage tank, if the first determination condition is met, the second determination condition is not met, the fifth determination condition is not met, the sixth determination condition is met, and the seventh determination condition is met, which states that the temperature of the hot water after heat exchange with the exhaust gas in the heat recovery heat exchanger is in a predetermined high-temperature state.

7. The fuel cell device includes a hot water storage tank for storing hot water, a heat exchanger for heat recovery that exchanges heat between the hot water and exhaust gas, which is discharged to the outside of the inner container and contains gas generated by combustion in the combustion section, and a thermal fuse provided in the middle of the power supply line from the power conversion circuit to the control device, which cuts the power supply line when the temperature of the hot water supplied from the heat recovery heat exchanger to the hot water storage tank reaches a predetermined high temperature. An abnormality diagnosis device according to claim 1, which determines that an abnormality has occurred in the power system if the first determination condition is met, the second determination condition is not met, the fifth determination condition is met, which is that the system voltage in the power system, the temperature of the hot water supplied from the heat recovery heat exchanger to the hot water storage tank, and the output voltage of the cell stack have been obtained when the first determination condition is met, and the eighth determination condition is not met, which is that the system voltage in the power system is within the normal range.

8. An abnormality diagnosis device according to claim 7, which determines that an abnormality has occurred in the heat recovery system in which the hot water supplied from the heat recovery heat exchanger recovers heat from the exhaust gas in the heat recovery heat exchanger and returns to the hot water storage tank, if the first determination condition is met, the second determination condition is not met, the fifth determination condition is met, the eighth determination condition is met, the ninth determination condition that the low voltage state occurred while the power generation of the cell stack was stopped is not met, and the tenth determination condition that the temperature of the hot water supplied from the heat recovery heat exchanger to the hot water storage tank is in a predetermined high temperature state.

9. An abnormality diagnosis device according to claim 7, which determines that an abnormality has occurred in the hot module if the first determination condition is met, the second determination condition is not met, the fifth determination condition is met, the eighth determination condition is met, the ninth determination condition that the low voltage state occurred while the power generation of the cell stack was stopped is not met, the tenth determination condition that the temperature of the hot water supplied from the heat recovery heat exchanger to the hot water storage tank is at a predetermined high temperature is not met, and the eleventh determination condition that the output voltage of the cell stack is above a predetermined value is not met.

10. An abnormality diagnosis device according to claim 9, which determines that an abnormality has occurred in the power conversion circuit if the first determination condition is met, the second determination condition is not met, the fifth determination condition is met, the eighth determination condition is met, the ninth determination condition is not met, the tenth determination condition is not met, the eleventh determination condition is met, and the twelfth determination condition, in which the voltage of the DC power supplied by the power conversion circuit to the DC auxiliary equipment is within a set range including zero, is not met.

11. An abnormality diagnosis device according to claim 9, which determines that the thermal fuse has cut the power supply line if the first determination condition is met, the second determination condition is not met, the fifth determination condition is met, the eighth determination condition is met, the ninth determination condition is not met, the tenth determination condition is not met, the eleventh determination condition is met, and the twelfth determination condition is met, which is that the voltage of the DC power supplied by the power conversion circuit to the DC auxiliary equipment is within a set range including zero.

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