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 conversion circuit if the first determination condition is met, which is that the output current of the cell stack is in a predetermined high-current state, which is greater than the assumed current value assumed from the power output from the power conversion circuit to the power line, or that output suppression operation is being performed, and the second determination condition is met, which is that the output of the cooling fan is in a predetermined high-output state, which is greater than the standard output range, and the third determination condition is not met, which is that the output voltage of the cell stack is in a predetermined low-voltage state.

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 Unexamined Patent Application Publication 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 failure data at the time of the current failure is selected. Further, a failure diagnosis result and a 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 a 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 unit in the inner space of the outer container that converts the power generated by the cell stack into desired AC power and outputs the AC power to a single-phase three-wire power line connected to the power grid; a cooling fan that air-cools the power conversion circuit unit by circulating the air in the inner space of the outer container; an air intake provided in the outer container through which air taken in from outside the outer container into the inner space of the outer container passes; an air outlet provided in the outer container through which air discharged from the inner space of the outer container to outside the outer container passes; a ventilation fan that ventilates the air in the inner space of the outer container via the air intake and the air outlet by circulating the air in the inner space of the outer container; a space temperature measuring device that measures the temperature of the air in the inner space of the outer container; a circuit temperature measuring device that measures the temperature of the power conversion circuit unit; a ventilation air filter provided at the air intake that removes foreign matter contained in the air taken in from outside the outer container into the inner space of the outer container; and a control device that controls the operation of the fuel cell device. The fuel cell device is configured to perform an output suppression operation that reduces the power generated by the cell stack when the internal temperature, which is the temperature of a predetermined part inside the device, reaches at least a reference temperature, and to increase the output of the cooling fan as the temperature of the power conversion circuit section measured by the circuit temperature measuring instrument increases. The point is that if the output current of the cell stack is in a predetermined high-current state, which is greater than the assumed current value assumed from the power output from the power conversion circuit to the power line, or if the first determination condition is met, and the second determination condition is not met, which is a predetermined high-output state, where the output of the cooling fan is greater than the standard output range, and the third determination condition is not met, which is a predetermined low-voltage state, then it is determined that an abnormality has occurred in the power conversion circuit.

[0007] According to the above characteristic configuration, the abnormality diagnosis device determines that an abnormality has occurred in the power conversion circuit if the first determination condition is met, which is that the output current of the cell stack is in a predetermined high-current state, which is greater than the assumed current value assumed from the power output from the power conversion circuit to the power line, or that output suppression operation is being performed, and the second determination condition is not met, which is that the output of the cooling fan is in a predetermined high-output state, which is greater than the standard output range, and the third determination condition is not met, which is that the output voltage of the cell stack is in a predetermined low-voltage state. In other words, the abnormality diagnosis device can automatically determine the diagnosis result for an abnormality appearing in the output current of the cell stack or for an event indicating that output suppression operation is being performed.

[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 feature 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, and the third determination condition is met, it is determined that an abnormality has occurred in the cell stack.

[0010] According to the above characteristic configuration, the abnormality diagnosis device can automatically diagnose that an abnormality has occurred in the cell stack if the first judgment condition is met, the second judgment condition is not met, and the third judgment condition is met.

[0011] 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 unit in the inner space of the outer container that converts the power generated by the cell stack into desired AC power and outputs the AC power to a single-phase three-wire power line connected to the power grid; a cooling fan that air-cools the power conversion circuit unit by circulating the air in the inner space of the outer container; an air intake provided in the outer container through which air taken in from outside the outer container into the inner space of the outer container passes; an air outlet provided in the outer container through which air discharged from the inner space of the outer container to outside the outer container passes; a ventilation fan that ventilates the air in the inner space of the outer container via the air intake and the air outlet by circulating the air in the inner space of the outer container; a space temperature measuring device that measures the temperature of the air in the inner space of the outer container; a circuit temperature measuring device that measures the temperature of the power conversion circuit unit; a ventilation air filter provided at the air intake that removes foreign matter contained in the air taken in from outside the outer container into the inner space of the outer container; and a control device that controls the operation of the fuel cell device. The fuel cell device is configured to perform an output suppression operation that reduces the generated power when the internal temperature, which is the temperature of a predetermined part inside the device, reaches at least a reference temperature, and to increase the output of the cooling fan as the temperature of the power conversion circuit section measured by the circuit temperature measuring instrument increases. The first determination condition is met, which is that the output current of the cell stack is in a predetermined high-current state, which is greater than the assumed current value assumed from the power generated by the cell stack, or that the output suppression operation is being performed, and the second determination condition is met, which is that the output of the cooling fan is in a predetermined high-output state, which is greater than the standard output range, and the fourth determination condition is not met, which is that the temperature of the space inside the outer container measured by the space temperature measuring instrument is above the set temperature. In this case, it is determined that there is an abnormality in the circuit temperature measuring instrument or an abnormality in the control device.

[0012] According to the above characteristic configuration, the abnormality diagnosis device determines that an abnormality has occurred in the circuit temperature measuring instrument or the control device if the first determination condition is met, which is that the output current of the cell stack is in a predetermined high-current state where it is greater than the assumed current value expected from the power generated by the cell stack, or that output suppression operation is being performed, and the second determination condition is met, which is that the output of the cooling fan is in a predetermined high-output state where it is greater than the standard output range, and the fourth determination condition is not met, which is that the temperature of the space inside the outer container measured by the space temperature measuring instrument is above the set temperature. In other words, the abnormality diagnosis device can automatically determine the diagnosis result for an abnormality that appears in the output current of the cell stack or that output suppression operation is being performed.

[0013] 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.

[0014] 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 fourth determination condition is met, and the fifth determination condition is met, which is that the temperature of the space inside the outer container measured by the space temperature measuring instrument has been at or above the set temperature since the initial start of use of the fuel cell device, then it is determined that an abnormality has occurred in the power conversion circuit.

[0015] According to the above characteristic configuration, when the first determination condition is satisfied, the second determination condition is satisfied, the fourth determination condition is satisfied, and the fifth determination condition that the temperature of the space inside the outer container measured by the space temperature measuring device is equal to or higher than the set temperature continues from the initial stage of starting the use of the fuel cell device is satisfied, the abnormality diagnosis device can automatically perform a diagnosis that an abnormality has occurred in the power conversion circuit unit.

[0016] 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 satisfied, the fourth determination condition is satisfied, and the fifth determination condition that the temperature of the space inside the outer container measured by the space temperature measuring device is equal to or higher than the set temperature continues from the initial stage of starting the use of the fuel cell device is not satisfied, it is determined that poor ventilation has occurred in the space inside the outer container.

[0017] According to the above characteristic configuration, when the first determination condition is satisfied, the second determination condition is satisfied, the fourth determination condition is satisfied, and the fifth determination condition that the temperature of the space inside the outer container measured by the space temperature measuring device is equal to or higher than the set temperature continues from the initial stage of starting the use of the fuel cell device is not satisfied, the abnormality diagnosis device can automatically perform a diagnosis that poor ventilation has occurred in the space inside the outer container.

Brief Description of the Drawings

[0018] [Figure 1] It is a diagram showing the configuration of a diagnosis system including an abnormality diagnosis device. [Figure 2] It is a diagram showing the configuration of a fuel cell device. [Figure 3] It is a diagram for explaining the electrical connection form among the power system, the fuel cell device, and the power consumption device. [Figure 4] It is a flowchart for explaining an example of an abnormality diagnosis process.

Embodiments for Carrying Out the Invention

[0019] 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.

[0020] 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.

[0021] 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 hydrocarbon-containing gas 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.

[0022] 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.

[0023] 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.

[0024] [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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] [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.

[0034] 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.

[0035] 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.

[0036] [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.

[0037] 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.

[0038] [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.

[0039] [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).

[0040] [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.

[0041] [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.

[0042] 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, i.e., heat is accumulated, while forming a temperature stratification.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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. For example, if the temperature measured by the circuit temperature measuring instrument T11 exceeds a predetermined upper limit temperature, the fuel cell control unit 49 operates the cooling fan 47 to adjust its output so that the temperature falls below the upper limit temperature. Furthermore, a predetermined standard output range is defined for the output of the cooling fan 47 when the fuel cell device 10 is operating normally, and the output of the cooling fan 47 will not exceed this standard output range when the fuel cell device 10 is operating normally. In addition, the fuel cell device 10 includes an output current measuring instrument 52 for measuring the output current of the cell stack 18 and an output voltage measuring instrument 53 for measuring the output voltage of the cell stack 18.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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 unit 46 to the control device (fuel cell control unit 49), 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] The operating status of the equipment described above 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.), what processing process the fuel cell device 10 is currently performing, such as the start-up process, power generation process, and shutdown process, and the length of time each processing process is being performed.

[0060] 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.

[0061] 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.

[0062] [Anomaly Diagnosis Processing] Figure 4 is a flowchart showing the contents of the abnormality diagnosis process in which the diagnostic processing unit 4b diagnoses whether the output current of the cell stack 18 is in a predetermined high-current state, which is greater than the expected current value expected from the power output from the power conversion circuit unit 46 to the power line 8, or whether output suppression operation is being performed.

[0063] As shown in Figure 3, the output current of the cell stack 18 is supplied from the power conversion circuit 46 to the power line 8 and the DC auxiliary equipment 58. Therefore, even if the power output from the power conversion circuit 46 to the power line 8 does not change, if the power consumption of the DC auxiliary equipment 58 increases, the output current of the cell stack 18 will also increase. Consequently, if the power consumption of the DC auxiliary equipment 58 increases due to some abnormality occurring in the fuel cell device 10, a predetermined high-current state occurs in which the output current of the cell stack 18 is greater than the assumed current value expected from the power output from the power conversion circuit 46 to the power line 8. In addition, the fuel cell control unit 49 performs output suppression operation to suppress the power generated by the cell stack 18, provided that the internal temperature of the device, which is the temperature of a predetermined part inside the device, is at least above the reference temperature. In other words, a predetermined high-current state in which the output current of the cell stack 18 is greater than the assumed current value expected from the power output from the power conversion circuit 46 to the power line 8, or a state in which output suppression operation is being performed, indicates that some abnormality has occurred in the fuel cell device 10.

[0064] Therefore, the diagnostic processing unit 4b executes the flowchart shown in Figure 4 at the set timing. Specifically, in step #10, the diagnostic processing unit 4b determines whether a first determination condition is met, which is that the output current of the cell stack 18 is in a predetermined high-current state where it is greater than the expected current value expected from the power output from the power conversion circuit unit 46 to the power line 8, or that output suppression operation is being performed. If the first determination condition is not met, the diagnostic processing unit 4b returns to the beginning of this flowchart, and if the first determination condition is met, it proceeds to step #11.

[0065] In step #11, the diagnostic processing unit 4b determines whether a second determination condition is met, which is that the output of the cooling fan 47 is greater than the standard output range, indicating a predetermined high-output state. As described above, if the temperature measured by the circuit temperature measuring instrument T11 exceeds a predetermined upper limit temperature, the fuel cell control unit 49 operates the cooling fan 47 to adjust its output so that the temperature falls below the upper limit temperature. The memory unit 4a stores the standard output range for the cooling fan 47 when the fuel cell device 10 is operating normally. If the second determination condition is not met, the diagnostic processing unit 4b proceeds to step #12; if the second determination condition is met, it proceeds to step #13.

[0066] In step #12, the diagnostic processing unit 4b determines whether the third determination condition is met, which is that the output voltage (stack voltage) of the cell stack 18 is in a predetermined low voltage state. For example, if the output voltage of the cell stack 18 is below the threshold voltage at which degradation of the cell stack 18 is diagnosed, it is determined that the cell stack 18 is in a low voltage state. In other words, if the third determination condition is met, the diagnostic processing unit 4b arrives at diagnosis result A2, which indicates that an abnormality has occurred in the cell stack 18. It is determined that the output current has increased due to degradation (i.e., an abnormality) of the cell stack 18, resulting in the high current state described above. In other words, the diagnostic processing unit 4b determines that an abnormality has occurred in the cell stack 18 if the first determination condition is met, which is that the output current of the cell stack 18 is in a predetermined high current state, which is greater than the expected current value expected from the power generated by the cell stack 18, or that output suppression operation is being performed, and the second determination condition is not met, which is that the output of the cooling fan 47 is in a predetermined high output state, which is greater than the standard output range, and the third determination condition is met, which is that the output voltage of the cell stack 18 is in a predetermined low voltage state. In other words, a diagnosis is made that an abnormality has occurred in the cell stack 18, resulting in a predetermined high-current state where the output current of the cell stack 18 is greater than the expected current value expected from the power output from the power conversion circuit 46 to the power line 8, or that output suppression operation is being performed. Thus, the judgment result of the judgment process in step #12 includes cases where the diagnosis result of the abnormality diagnosis process is identified.

[0067] The content of diagnostic result A2 is not limited to what is described above. For example, it may include diagnostic results such as "current increase due to deterioration of cell stack 18," "replacement of cell stack 18," or "repair of cell stack 18." In addition, although several examples of diagnostic result A2 are listed, they may be used alone or in combination with any of the others.

[0068] In response, if the third determination condition is not met, the diagnostic processing unit 4b arrives at diagnosis result A1, 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 first determination condition is met, which is that the output current of the cell stack 18 is in a predetermined high-current state, which is greater than the assumed current value assumed from the power output from the power conversion circuit unit 46 to the power line 8, or that output suppression operation is being performed, and the second determination condition is not met, which is that the output of the cooling fan 47 is in a predetermined high-output state, which is greater than the standard output range, and the third determination condition is not met, which is that the output voltage of the cell stack 18 is in a predetermined low-voltage state. In other words, an abnormality in the power conversion circuit unit 46 leads to a diagnosis result that the output current of the cell stack 18 is in a predetermined high-current state, which is greater than the assumed current value assumed from the power output from the power conversion circuit unit 46 to the power line 8, or that output suppression operation is being performed. Thus, the judgment result of the judgment process in step #12 includes cases where it leads to the identification of the diagnosis result of the anomaly diagnosis process.

[0069] The content of diagnostic result A1 is not limited to what is described above. For example, it may include diagnostic results such as "deterioration of the conversion efficiency of the power conversion circuit unit 46," "replacement of the power conversion circuit unit 46," or "repair of the power conversion circuit unit 46." In addition, although several examples of diagnostic result A1 are listed, they may be used alone or in combination with any of the others.

[0070] In step #13, the diagnostic processing unit 4b determines whether the fourth determination condition is met, which is that the temperature of the space inside the outer container 48 measured by the ambient temperature measuring instrument T3 is above the set temperature (for example, 40°C or higher). If the fourth determination condition is not met, the diagnostic processing unit 4b arrives at diagnosis result A3, which indicates that there is an abnormality in the circuit temperature measuring instrument T11 or in the control device (fuel cell control unit 49). In other words, the diagnostic processing unit 4b determines that there is an abnormality in the circuit temperature measuring instrument T11 or in the control device (fuel cell control unit 49) if the first determination condition is met, which is that the output current of the cell stack 18 is in a predetermined high-current state where it is greater than the assumed current value assumed from the power generated by the cell stack 18, or that output suppression operation is being performed, and the second determination condition is met, which is that the output of the cooling fan 47 is in a predetermined high-output state where it is greater than the standard output range, and the fourth determination condition is not met, which is that the temperature of the space inside the outer container 48 measured by the ambient temperature measuring instrument T3 is above the set temperature. In other words, the diagnostic processing unit 4b diagnoses that an abnormality has occurred in the circuit temperature measuring instrument T11, or an abnormality has occurred in the control device (fuel cell control unit 49), resulting in a predetermined high-current state where the output current of the cell stack 18 is greater than the expected current value expected from the power output from the power conversion circuit unit 46 to the power line 8, or that output suppression operation is being performed. Thus, the judgment result of the judgment process in step #13 includes cases where the diagnosis result of the abnormality diagnosis process is identified.

[0071] The content of diagnostic result A3 is not limited to what is described above. For example, it may be a diagnostic result such as "replacement of circuit temperature measuring device T11 or control device (fuel cell control unit 49)" or a diagnostic result such as "repair of circuit temperature measuring device T11 or control device (fuel cell control unit 49)". In addition, although several examples of diagnostic result A3 are listed, they may be used alone or in combination with any of the others.

[0072] If the diagnostic processing unit 4b determines that the fourth determination condition is met in process #13, it proceeds to process #14. Thus, the determination result of the determination process in process #13 includes cases where a transition to another determination process is instructed.

[0073] In step #14, the diagnostic processing unit 4b determines whether the fifth determination condition is met, which is that the temperature of the space inside the outer container 48, as measured by the ambient temperature measuring instrument T3, has remained above the set temperature since the initial start of use of the fuel cell device 10. If the fifth determination condition is met, the diagnostic processing unit 4b arrives at diagnosis result A4, 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 first determination condition is met, the second determination condition is met, the fourth determination condition is met, and the fifth determination condition is met, which is that the temperature of the space inside the outer container 48, as measured by the ambient temperature measuring instrument T3, has remained above the set temperature (40°C) since the initial start of use of the fuel cell device 10. In other words, the diagnostic processing unit 4b diagnoses that an abnormality has occurred in the power conversion circuit unit 46, resulting in a predetermined high-current state where the output current of the cell stack 18 is greater than the expected current value expected from the power output from the power conversion circuit unit 46 to the power line 8, or that output suppression operation is being performed. Thus, the determination result of the determination process in step #14 includes cases where the diagnosis result of the abnormality diagnosis process is identified.

[0074] The content of diagnostic result A4 is not limited to what is described above. For example, it may include diagnostic results such as "abnormality in the power conversion circuit section 46 due to manufacturing defects such as poor soldering," "replacement of the power conversion circuit section 46," or "repair of the power conversion circuit section 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.

[0075] In response, if the fifth determination condition is not met, the diagnostic processing unit 4b arrives at diagnosis result A5, which indicates that poor ventilation has occurred in the space inside the outer container 48. In other words, if the first determination condition is met, the second determination condition is met, the fourth determination condition is met, and the fifth determination condition, which states that the temperature of the space inside the outer container 48 measured by the space temperature measuring instrument T3 has been at or above the set temperature (40°C) since the start of use of the fuel cell device 10, is not met, the diagnostic processing unit 4b determines that poor ventilation has occurred in the space inside the outer container 48. In other words, the diagnostic processing unit 4b arrives at a diagnosis result that, due to poor ventilation in the space inside the outer container 48, the output current of the cell stack 18 is in a predetermined high-current state, which is greater than the expected current value expected from the power output from the power conversion circuit unit 46 to the power line 8, or that output suppression operation is being performed. Thus, the determination result of the determination process in step #14 includes cases where the diagnosis result of the abnormality diagnosis process is identified.

[0076] The content of diagnostic result A5 is not limited to what is described above. For example, it may include diagnostic results such as "Abnormality of cooling fan 47," "Replacement of cooling fan 47," "Abnormality of ventilation fan 59," "Replacement of ventilation fan 59," "Abnormality of ventilation air filter 77," or "Replacement of ventilation air filter 77." In addition, although several examples of diagnostic result A5 are listed, they may be used alone or in combination with any of the others.

[0077] 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 anomaly diagnosis device 4 automatically identifies the diagnosis result for the anomaly, allowing maintenance personnel to prepare in advance according to the diagnosis result before being dispatched.

[0078] 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 necessary parts for repairs based on the diagnostic results. As a result, problems such as the lack of personnel with the necessary skills to perform the repairs or the failure to bring the necessary parts to the site can be avoided.

[0079] 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.

[0080] If the response to an abnormality includes instructions for replacing or repairing the components of the fuel cell device 10 as described above, then it is possible to prepare the components to be replaced in advance and to determine the personnel required for the replacement or repair work in advance.

[0081] 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.

[0082] 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.

[0083] <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.

[0084] 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.

[0085] 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]

[0086] 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]

[0087] 1: Facility 2: Information and communication lines 3: Single-phase 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 46: Power Conversion Circuit Section 47: Cooling fan 48: Space inside the outer container 49: Fuel cell control unit (control device) 59: Ventilation fan 63: Power system 67: Air intake 77: Ventilation air filter T3: Space temperature measuring device T11:Circuit temperature measuring device

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 unit in the inner space of the outer container that converts the power generated by the cell stack into desired AC power and outputs the AC power to a single-phase three-wire power line connected to the power grid; a cooling fan that air-cools the power conversion circuit unit by circulating the air in the inner space of the outer container; an air intake provided in the outer container through which air taken in from outside the outer container into the inner space of the outer container passes; an air outlet provided in the outer container through which air discharged from the inner space of the outer container to outside the outer container passes; a ventilation fan that ventilates the air in the inner space of the outer container via the air intake and the air outlet by circulating the air in the inner space of the outer container; a space temperature measuring device that measures the temperature of the air in the inner space of the outer container; a circuit temperature measuring device that measures the temperature of the power conversion circuit unit; a ventilation air filter provided at the air intake that removes foreign matter contained in the air taken in from outside the outer container into the inner space of the outer container; and a control device that controls the operation of the fuel cell device. The fuel cell device is configured to perform an output suppression operation that reduces the power generated by the cell stack when the internal temperature, which is the temperature of a predetermined part inside the device, reaches at least a reference temperature, and to increase the output of the cooling fan as the temperature of the power conversion circuit section measured by the circuit temperature measuring instrument increases. An abnormality diagnosis device that determines that an abnormality has occurred in the power conversion circuit when the output current of the cell stack is in a predetermined high-current state, which is greater than the assumed current value assumed from the power output from the power conversion circuit to the power line, or when the first determination condition is met, and the second determination condition is not met, which is when the output of the cooling fan is in a predetermined high-output state, which is greater than the standard output range, and the third determination condition is not met, which is when the output voltage of the cell stack is in a predetermined low-voltage state.

2. An abnormality diagnosis device according to claim 1, which determines that an abnormality has occurred in the cell stack if the first determination condition is met, the second determination condition is not met, and the third determination condition is met.

3. 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 unit in the inner space of the outer container that converts the power generated by the cell stack into desired AC power and outputs the AC power to a single-phase three-wire power line connected to the power grid; a cooling fan that air-cools the power conversion circuit unit by circulating the air in the inner space of the outer container; an air intake provided in the outer container through which air taken in from outside the outer container into the inner space of the outer container passes; an air outlet provided in the outer container through which air discharged from the inner space of the outer container to outside the outer container passes; a ventilation fan that ventilates the air in the inner space of the outer container via the air intake and the air outlet by circulating the air in the inner space of the outer container; a space temperature measuring device that measures the temperature of the air in the inner space of the outer container; a circuit temperature measuring device that measures the temperature of the power conversion circuit unit; a ventilation air filter provided at the air intake that removes foreign matter contained in the air taken in from outside the outer container into the inner space of the outer container; and a control device that controls the operation of the fuel cell device. The fuel cell device is configured to perform an output suppression operation that reduces the generated power when the internal temperature, which is the temperature of a predetermined part inside the device, reaches at least a reference temperature, and to increase the output of the cooling fan as the temperature of the power conversion circuit section measured by the circuit temperature measuring instrument increases. An abnormality diagnostic device that determines that an abnormality has occurred in the circuit temperature measuring instrument or in the control device if the first determination condition is met, which is that the output current of the cell stack is in a predetermined high-current state, which is greater than the assumed current value assumed from the power generated by the cell stack, or that the output suppression operation is being performed, and the second determination condition is met, which is that the output of the cooling fan is in a predetermined high-output state, which is greater than the standard output range, and the fourth determination condition is not met, which is that the temperature of the space inside the outer container measured by the space temperature measuring instrument is above the set temperature.

4. An abnormality diagnosis device according to claim 3, which determines that an abnormality has occurred in the power conversion circuit when the first determination condition is met, the second determination condition is met, the fourth determination condition is met, and the fifth determination condition is met, which is that the temperature of the space inside the outer container measured by the space temperature measuring instrument has been at or above the set temperature since the initial start of use of the fuel cell device.

5. An abnormality diagnosis device according to claim 3 or 4, which determines that poor ventilation of the space inside the outer container has occurred if the first determination condition is met, the second determination condition is met, the fourth determination condition is met, and the fifth determination condition, which states that the temperature of the space inside the outer container measured by the space temperature measuring instrument has been at or above the set temperature since the initial start of use of the fuel cell device, is not met.

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