JP5041662B2 - FUEL CELL SYSTEM, FUEL CELL SYSTEM CONTROL METHOD, AND FUEL CELL SYSTEM ABNORMALITY DETECTING METHOD - Google Patents

Description

  The present invention relates to a fuel cell system, a fuel cell system control method, and a fuel cell system abnormality detection method.

  In general, an electrolyte membrane, for example, a cell for a polymer electrolyte fuel cell using a solid polymer electrolyte membrane is constructed by joining an anode to one surface of a solid polymer electrolyte membrane and a cathode to the other surface. A membrane electrode assembly (hereinafter referred to as “MEA”), an anode side plate in which a fuel flow path is provided so as to sandwich the MEA, and a cathode side plate in which an oxidant flow path is formed Is done. A cell stack is formed by stacking a plurality of cells having such a structure, and a fuel cell is formed by attaching and tightening end plates to both ends of the cell stack.

In the solid polymer fuel cell, a fuel gas containing H ₂ is circulated through the anode side plate, and an oxidant gas such as air containing O ₂ is circulated through the cathode side plate, and electricity is passed through the solid polymer electrolyte membrane. Electricity is generated by causing a chemical reaction.

In the polymer electrolyte fuel cell, unless the reaction heat of H ₂ and O ₂ inside the cell is released to the outside, the cell temperature rises, the electrolyte membrane is damaged, and the efficiency of the electrochemical reaction decreases. To do. For this reason, in the fuel cell system, a heat medium, for example, a coolant such as water is circulated in the cell stack, and is controlled to a predetermined temperature, for example, 75 ° C. or lower.

  As such a fuel cell system, the refrigerant is circulated in the cell stack by the refrigerant pump, the flow rate and discharge pressure of the refrigerant pump are detected, and when one of these is out of the normal range, the refrigerant circulation system malfunctions. Is known (for example, see Patent Document 1).

JP 2002-184435 A

  However, in this fuel cell system, the time difference between the actual occurrence of abnormality in the refrigerant circulation system and the detection of abnormality in the refrigerant circulation system is large, and when the abnormality is detected and the fuel cell system is stopped, the electrolyte membrane starts to be damaged. There may be.

  Further, in this fuel cell system, a device for detecting the flow rate and discharge pressure of the refrigerant pump is provided in the refrigerant circulation system, and the refrigerant circulation system is controlled based on the detection result, so that the structure becomes complicated and the cost of the fuel cell system is reduced. Invite up.

  The present invention has been made in view of the above problems, and an object of the present invention is to quickly detect a temperature abnormality of a fuel cell system with a simple configuration.

The fuel cell system of the present invention includes an electrolyte membrane, an anode provided on one surface of the electrolyte membrane, a membrane electrode assembly having a cathode provided on the other surface of the electrolyte membrane, and a fuel facing the anode. 3 consisting of an anode side plate in which a channel is formed, a cathode side plate in which an oxidant channel facing the cathode is formed, and a heat medium channel plate provided with a heat medium channel through which the heat medium flows. Two plates, or two bipolar plates each with a heat medium channel formed on the opposite side of the surface on which the fuel channel and the oxidant channel are formed, or a fuel channel or an oxidant channel are formed One plate of two plates consisting of one bipolar plate and an anode side plate or a cathode side plate in which a heat medium flow path is formed on the opposite side of the formed surface is provided A fuel cell including a cell stack in which a plurality of cells are stacked, a heat medium supply means for introducing a heat medium into the heat medium flow path, and a temperature near a heat medium outlet from which the heat medium is discharged from the cell stack ( T1) and the temperature (T2) of the outer surface of the fuel cell, and when the temperature T1, T2 and the temperature difference T2-T1 measured by the temperature sensor satisfy predetermined conditions, abnormality and determining system abnormality detecting means, a fuel cell system that having a, the system abnormality detecting means, Ts1 the temperature of the temperature and the outer surface near the heat medium outlet of the normal operation of the fuel cell, respectively, and (1) When T1 is substantially the same temperature as Ts1 and T2 is higher than Ts2, it is estimated that the introduction of the heat medium into the fuel cell is stopped,
(2) When T1 is at a higher temperature than Ts1, T2 is at a higher temperature than Ts2, and T2-T1 is substantially the same temperature as Ts2-Ts1, the amount of heat medium introduced into the fuel cell is reduced. Or the fuel cell is heating up abnormally,
(3) When T1 is a low temperature compared to Ts1, T2 is a low temperature compared to Ts2, and T2-T1 is substantially the same temperature as Ts2-Ts1, the temperature of the heat medium introduced into the fuel cell is abnormal. It is presumed to exist.
Further, the temperature sensor measures a temperature T3 in the vicinity of the heat medium inlet at which the heat medium is introduced into the cell stack, and the system abnormality detection means detects the temperatures T1, T2, T3 and temperatures measured by the temperature sensor. A system abnormality is estimated based on the differences T2-T1 and T3-T1.
Furthermore, the system abnormality detection means sets the temperature near the heat medium inlet during normal operation of the fuel cell to Ts3,
(1) When T3 is substantially the same temperature as Ts3 and T1-T3 is substantially the same temperature as Ts1-Ts3, it is assumed that the introduction of the heat medium into the fuel cell is stopped,
(2) When T3 is substantially the same temperature as Ts3 and T1-T3 is at a higher temperature than Ts1-Ts3, the amount of heat medium introduced into the fuel cell is reduced, or the fuel cell generates abnormal heat. Guess that
(3) When T3 is higher than Ts3 and T1-T3 is substantially the same temperature as Ts1-Ts3, it is estimated that the temperature of the heat medium introduced into the fuel cell is abnormal.

  According to this fuel cell system, a temperature abnormality can be detected quickly with a simple configuration.

  The system abnormality detection means includes a heat medium supply control means and / or a fuel cell that stops introduction of the heat medium from the heat medium supply means to the heat medium flow path when the temperature measured by the temperature sensor satisfies a predetermined condition. And a load control means for cutting off the connection with the electric load supplied with power from the fuel cell, and a system control means for stopping the operation of the system. According to this configuration, it is possible to easily and quickly stop the operation of the introduction system of the heat medium that is likely to be an abnormality occurrence site.

  At this time, the temperature sensor is preferably provided in the vicinity of the oxidant flow path on the outer surface of the fuel cell. In the oxidant flow path, reaction heat is generated by an electrochemical reaction, so that the temperature is likely to rise in the vicinity of the oxidant flow path. By providing a temperature sensor in the vicinity of the oxidant flow path on the outer surface of the fuel cell, it is possible to quickly detect whether the heat medium releases reaction heat due to electrochemical reaction to the outside of the cell, that is, quickly. Temperature abnormality can be detected.

  The temperature sensor is preferably provided in the vicinity of the oxidant gas outlet from which the oxidant gas is discharged from the oxidant flow path. In the vicinity of the cathode gas outlet, the temperature rise due to the abnormality of the heat medium introduction system is more significant than in the vicinity of the cathode gas inlet. According to this configuration, the temperature abnormality can be detected quickly.

  The temperature sensor may be provided on the outer surface near the center of the cell stack in the stacking direction. In the cell stack, the temperature increase due to the abnormality in the heat medium introduction system is more remarkable in the cell near the center in the stacking direction than in the cell near the end in the stacking direction. Therefore, according to this configuration, a temperature abnormality can be detected quickly.

The temperature sensor is a non-contact type temperature sensor.

  According to this fuel cell system, a temperature abnormality can be detected quickly with a simple configuration. Further, since the temperature of the outer surface of the fuel cell is measured by a non-contact type temperature sensor, it is possible to easily cope with the case where the measurement location of the outer surface of the fuel cell is to be changed.

A control method for a fuel cell system according to the present invention includes an electrolyte membrane, an anode provided on one surface of the electrolyte membrane, a membrane electrode assembly having a cathode provided on the other surface of the electrolyte membrane, An anode side plate in which opposed fuel channels are formed, a cathode side plate in which oxidant channels facing the cathode are formed, and a heat medium channel plate provided with a heat medium channel through which the heat medium flows Or two bipolar plates each having a heat medium flow path formed on the opposite side of the surface on which the fuel flow path and the oxidant flow path are formed, or the fuel flow path or the oxidant flow One of the two plates consisting of one bipolar plate having a heat medium flow path formed on the opposite surface to the surface on which the path is formed and an anode side plate or a cathode side plate A step of introducing a fuel gas into the fuel flow path of a fuel cell including a cell stack in which a plurality of cells including a cell are stacked, a step of introducing an oxidant gas into the oxidant flow path, and the heat medium flow path A step of introducing a heat medium into the fuel cell, and a temperature in the vicinity of the heat medium outlet at which the heat medium is discharged from the cell stack when the fuel gas, the oxidant gas, and the heat medium are introduced into the fuel cell ( T1) and the temperature (T2) of the outer surface of the fuel cell, and the temperature near the heat medium outlet and the temperature of the outer surface during normal operation of the fuel cell are Ts1 and Ts2, respectively. When the temperature and the temperature difference satisfy the following conditions (1) to (3): (1) T3 is substantially the same temperature as Ts3, and T1-T3 is substantially the same temperature as Ts1-Ts3. (2) T3 is almost equal to Ts3 At the same temperature, and, when T1-T3 is hot compared to Ts1-Ts3, (3) T3 is at a high temperature as compared to Ts3, and, when the temperature almost the same as T1-T3 is Ts1-Ts3, the heat Stopping the operation of the system comprising: stopping the introduction of the heat medium into the medium flow path and / or cutting off the connection between the fuel cell and an electric load supplied with electric power from the fuel cell; Have.

  According to the control method of this fuel cell system, it is possible to quickly detect a temperature abnormality with a simple procedure.

An abnormality detection method for a fuel cell system according to the present invention includes an electrolyte membrane, an anode provided on one surface of the electrolyte membrane, a membrane electrode assembly having a cathode provided on the other surface of the electrolyte membrane, and the anode A heat medium flow path provided with an anode side plate formed with a fuel flow path facing the cathode, a cathode side plate formed with an oxidant flow path facing the cathode, and a heat medium flow path through which the heat medium flows Three plates made of plates, or two bipolar plates each having a heat medium flow path formed on the opposite side of the surface on which the fuel flow path and the oxidant flow path are formed, or the fuel flow path or the oxidant One of two plates consisting of a bipolar plate and an anode side plate or a cathode side plate with a heat medium channel formed on the opposite side of the surface on which the channel is formed Introducing a fuel gas into the fuel flow path of a fuel cell including a cell stack in which a plurality of cells having a rate are stacked, introducing an oxidant gas into the oxidant flow path, and the heat medium flow path A step of introducing a heat medium into the fuel cell, and a temperature in the vicinity of the heat medium outlet at which the heat medium is discharged from the cell stack when the fuel gas, the oxidant gas, and the heat medium are introduced into the fuel cell ( T1) and the temperature (T2) of the outer surface of the fuel cell, and the temperature near the heat medium outlet and the temperature of the outer surface during normal operation of the fuel cell are Ts1 and Ts2, respectively. When the temperature and the temperature difference satisfy the following conditions (1) to (3): (1) T3 is substantially the same temperature as Ts3, and T1-T3 is substantially the same temperature as Ts1-Ts3. (2) T3 is Ts3 At approximately the same temperature, and, when T1-T3 is hot compared to Ts1-Ts3, (3) T3 is at a high temperature as compared to Ts3, and, when the temperature almost the same as T1-T3 is Ts1-Ts3, fuel A step of determining that the battery system is abnormal and / or a step of determining that the temperature of the heat medium is abnormal.

  According to the abnormality detection method of this fuel cell system, it is possible to detect a temperature abnormality quickly with a simple procedure.

  In this fuel cell system abnormality detection method, the step of determining the abnormality of the fuel cell system may be a step of determining that an abnormality has occurred in the heat medium introduction system. According to this method, it is possible to detect an abnormality in the introduction system of the heat medium quickly with a simple procedure.

  In the above configuration, the fuel flow path plate, the oxidant flow path plate, and the heat medium flow path plate are not necessarily separate members. For example, the fuel flow path plate and the heat medium flow path plate may be configured by one member by providing a fuel flow path on one surface of the bipolar plate and a heat medium flow path on the other surface. .

  Moreover, what combined each element mentioned above suitably can also be contained in the range of the invention patented by this application.

  According to the present invention, a temperature abnormality of a fuel cell system can be detected quickly with a simple configuration.

  FIG. 1 is a schematic cross-sectional view of a cell stack 12 of a fuel cell 11 constituting a fuel cell system 10 according to an embodiment of the present invention, cut along a plane parallel to the cell stacking direction. In the present embodiment, the fuel cell 11 is a polymer electrolyte fuel cell. As shown in FIG. 1, the MEA 14 is configured by arranging an anode 18 and a cathode 20 on a solid polymer electrolyte membrane 16.

  The anode side plate 22 is provided with a plurality of fuel gas passages 24 facing the anode 18 of the MEA 14, and the cathode side plate 26 is provided with an oxidant flow facing the cathode 20 of the MEA 14. An oxidant gas flow path 28, which is a channel, is provided. The unit cell is configured by sandwiching the MEA 14 between the anode side plate 22 and the cathode side plate 26, and the cell stack 12 is configured by stacking a plurality of these cells. At both ends of the cell stack 12, a pair of end plates (see FIG. 3) for fastening the stack is arranged, thereby constituting a part of the polymer electrolyte fuel cell.

  On the upper side of the anode side plate 22, a fuel gas supply manifold hole that becomes a part of the side wall of the flow path when the fuel gas that is the anode gas flows in the cell stacking direction, and the oxidant gas that is the cathode gas are in the cell. Oxidant gas supply manifold hole that becomes a part of the side wall of the flow path when flowing in the stacking direction, and a cooling water supply that becomes a part of the side wall of the flow path when cooling water as the heat medium flows in the stacking direction of the cells Manifold holes (both not shown) are formed.

  Similarly, the upper part of the cathode side plate 26 also has a fuel gas supply manifold hole which becomes a part of the side wall of the flow path when the fuel gas as the anode gas flows in the cell stacking direction, and the oxidant gas as the cathode gas. Becomes part of the side walls of the flow path when the coolant flows as the heat medium in the stacking direction of the cells. Cooling water supply manifold holes (both not shown) are formed.

  A fuel gas inlet header 40 communicating with the fuel gas supply manifold hole is provided below the fuel gas supply manifold hole of the anode side plate 22. From the fuel gas inlet header 40, a fuel gas passage 24, which is a plurality of groove-like fuel passages extending vertically downward, is provided so as to face the anode 18 of the MEA 14. A fuel gas outlet header 44 that communicates with the plurality of fuel gas passages 24 is provided below the fuel gas passage 24.

  Similarly, an oxidant gas inlet header 46 communicating with the oxidant gas supply manifold hole is provided below the oxidant gas supply manifold hole of the cathode side plate 26. From the oxidant gas inlet header 46, an oxidant gas flow path 28, which is a plurality of groove-like oxidant flow paths extending vertically downward, is provided so as to face the cathode 20 of the MEA 14. Below the oxidant gas flow path 28, an oxidant gas outlet header 50 communicating with the plurality of oxidant gas flow paths 28 is provided.

  A cooling water inlet header 52 communicating with the cooling water supply manifold hole is provided below the cooling water supply manifold hole of the anode side plate 22 and the cathode side plate 26. From the cooling water inlet header 52, cooling water flow paths 54, which are a plurality of groove-like heat medium flow paths extending vertically downward, are provided.

  That is, recesses are formed on the surfaces of the anode side plate 22 and the cathode side plate 26 opposite to the surfaces facing the MEA 14, and the coolant channel 54 is formed by combining these recesses. A cooling water outlet header 56 communicating with the plurality of cooling water channels 54 is provided below the cooling water channel 54.

  In the present embodiment, both the anode side plate 22 and the cathode side plate 26 are provided with the cooling water inlet header 52 and the cooling water flow path 54. Instead, the anode side plate 22 or the cathode side plate is provided. A cooling water inlet header 52 and a cooling water channel 54 may be provided on one side of the plate 26.

  Further, either the cooling water inlet header 52 or the cooling water flow path 54 is provided on one side of the anode side plate 22 or the cathode side plate 26, and the cooling water inlet header 52 is provided on the other side of the anode side plate 22 or the cathode side plate 26. Or you may provide the other one of the cooling water flow path 54 so that the cooling water inlet header 52 and the cooling water flow path 54 may connect.

  Below the anode side plate 22 are a fuel gas discharge manifold hole that becomes a part of the side wall of the flow path when the fuel gas flows in the cell stacking direction, and a flow path when the oxidant gas flows in the cell stacking direction. An oxidant gas discharge manifold hole that becomes a part of the side wall of the liquid crystal and a cooling water discharge manifold hole that is a part of the side wall of the flow path when the cooling water flows in the cell stacking direction (both not shown) are formed. Yes.

  Similarly, a fuel gas discharge manifold hole that becomes a part of the side wall of the flow path when the fuel gas flows in the cell stacking direction and the oxidant gas flow in the cell stacking direction also below the cathode side plate 26. And an oxidant gas discharge manifold hole that is a part of the side wall of the flow path and a cooling water discharge manifold hole that is a part of the side wall of the flow path when cooling water flows in the cell stacking direction (both not shown) Is formed.

  The fuel gas discharge manifold hole communicates with the fuel gas outlet header 44, the oxidant gas discharge manifold hole communicates with the oxidant gas outlet header 50, and the coolant discharge manifold hole communicates with the coolant outlet header 56.

  Next, the flow of fuel gas, oxidant gas, and cooling water in the cell stack 12 will be described.

The fuel gas is distributed and supplied to each cell through a fuel gas supply manifold hole communicating in the stacking direction of the cell stack 12. The fuel gas used is one that is bubbled and humidified in water (see FIG. 2). The fuel gas supplied to each cell passes through the fuel gas inlet header 40 and flows through the fuel gas flow path 24 to supply hydrogen to the anode 18 and humidify the solid polymer electrolyte membrane 16. As the fuel gas, H ₂ or a reformed gas such as methane, propane, butane or methanol containing H ₂ as a main component can be used.

On the other hand, an oxidant gas such as air is distributed and supplied to each cell through an oxidant gas supply manifold hole communicating in the stacking direction of the cell stack 12. The oxidant gas supplied to each cell passes through the oxidant gas inlet header 46 and flows through the oxidant gas flow path 28 to supply O ₂ to the cathode 20.

  In each cell in which the fuel gas and the oxidant gas circulate, electric power is generated by the occurrence of an electrochemical reaction through the solid polymer electrolyte membrane 16. Unreacted fuel gas discharged from each cell joins at the fuel gas outlet header 44 and is discharged to the outside of the cell stack 12 through a fuel gas discharge manifold hole communicating in the stacking direction of the cell stack 12. . The discharged unreacted fuel gas is generally introduced into a reformer burner of a fuel reformer (not shown) and burned.

  In addition, unreacted oxidant gas discharged from each cell after power generation merges at the oxidant gas outlet header 50 and passes through the oxidant gas discharge manifold hole communicating with the cell stack 12 in the stacking direction. 12 is discharged to the outside.

  The cooling water is distributed and supplied to the respective cooling water flow paths 54 through the cooling water supply manifold holes communicating in the stacking direction of the cell stack 12. The cooling water flowing through each cooling water flow path 54 cools each cell and holds it at an appropriate operating temperature, for example, about 70 to 80 ° C. The cooling water is discharged to the outside of the cell stack 12 through a cooling water discharge manifold hole communicating in the stacking direction of the cell stack 12.

  Water generated in the fuel gas flow path 24 of the anode side plate 22 is discharged to the fuel gas outlet header 44. Since the fuel gas outlet header 44 is inclined toward the fuel gas discharge manifold hole, water is discharged into the fuel gas discharge manifold hole.

  Next, the fuel cell system 10 according to the present embodiment will be described with reference to FIG.

  FIG. 2 is a schematic configuration diagram of the fuel cell system 10 according to the present embodiment. As shown in FIG. 2, the fuel cell system 10 mainly includes a fuel cell 11, a cooling water circulation pump 74, a temperature sensor 76, and a system control unit 78. The fuel cell system 10 includes a heat exchanger 80, a fuel humidification tank 82 for humidifying the fuel gas, an air humidification tank 84 for humidifying the air as the oxidant gas, a filter 86, a fuel source 88, an air Source 90.

  The fuel cell 11 includes a cell stack 12 as shown in FIG. The cooling water circulation pump 74 constitutes a part of the heat medium supply means, and introduces cooling water into the fuel cell system 10. The cooling water discharged from the cooling water circulation pump 74 is cooled through the filter 86, the cell stack 12, the heat exchanger 80, the fuel humidification tank 82, and the air humidification tank 84 as shown in FIG. Return to water circulation pump 74.

  The temperature sensor 76 is provided in contact with the outer surface of the fuel cell 11. The detailed position where the temperature sensor 76 is provided will be described later. The temperature sensor 76 measures the temperature of the outer surface of the fuel cell 11 and sends the measurement result to the system control unit 78 that is also a system abnormality detection unit. In the present embodiment, the temperature sensor 76 is provided in contact with the outer surface of the fuel cell 11, but instead, the temperature of the outer surface of the fuel cell 11 is measured by a non-contact type temperature sensor. You may measure.

  In the present embodiment, one temperature sensor 76 is provided, but a plurality of temperature sensors may be provided instead. By providing a plurality of temperature sensors, the temperature can be measured with higher accuracy.

  The system control unit 78 that is a system control unit includes a cooling water circulation pump control unit 100 that is a heat medium supply control unit, a load control unit 102 that is a load control unit, a fuel control unit 104, and an air control unit 106. The system control unit 78 stops the operation of one or more parts of the fuel cell system 10 when the temperature measured by the temperature sensor 76 satisfies a predetermined condition.

  Here, as a case where the measured temperature satisfies a predetermined condition, when the measured temperature is higher than a temperature in a normal operation state of the fuel cell 11 by a certain temperature, for example, 3 ° C. or higher, the measured temperature When the rate of change in time is more than a certain numerical value, for example, 0.1 ° C./sec or more, or the measured temperature is a temperature that is higher than the temperature near the cooling water outlet from which cooling water is discharged from the cell stack 12 For example, the case where the temperature is lowered by 5 ° C. or more can be given.

  The cooling water circulation pump control unit 100 controls the discharge flow rate of the cooling water circulation pump 74 and the like. The load control unit 102 controls connection and disconnection between the fuel cell 11 and an electric load (not shown) to which power generated by the fuel cell 11 is supplied. The fuel control unit 104 controls the amount of fuel gas introduced from the fuel source 88 into the fuel cell 11. The air control unit 106 controls the amount of air introduced from the air source 90 into the fuel cell 11.

  The heat exchanger 80 reduces the temperature of the cooling water that has passed through the cell stack 12 and has increased in temperature. Water is stored in the fuel humidification tank 82, and the fuel gas supplied from the fuel source 88 is introduced into the cell stack 12 after passing through this water. For this reason, the fuel gas is introduced into the cell stack 12 with a relative humidity of approximately 100%.

  Similarly, water is also stored in the air humidification tank 84, and the air supplied from the air source 90 is introduced into the cell stack 12 after passing through this water. For this reason, air is also introduced into the cell stack 12 with a relative humidity of 100%. Since the fuel gas and air are introduced into the cell stack 12 with a relative humidity of approximately 100%, the solid polymer electrolyte membrane 16 is maintained in a wet state. The filter 86 filters impurities mixed in the cooling water.

  Next, the position of the temperature sensor 76 installed in the fuel cell 11 will be described with reference to FIGS. 3 to 5.

  FIG. 3 is a schematic external view of the cell stack 12 viewed from an oblique direction. End plates 110 and 110 are provided on both end faces of the cell stack 12. As shown in FIG. 3, the temperature sensor 76 is an oxidation that exhausts oxidant gas on the outer surface of the fuel cell 11, in the vicinity of the central part in the cell stacking direction, in the vicinity of the oxidant gas flow path 28. It is provided in the vicinity of the agent gas outlet. For this reason, the temperature abnormality of the fuel cell system 10 can be detected quickly. Here, the vicinity of the oxidant gas outlet is closer to the oxidant gas outlet than the center of the oxidant gas flow path 28 in consideration of the structure of the cell stack 12 and the shape and size of the temperature sensor 76. Is appropriately selected.

  FIG. 4 shows the temperature near the oxidant gas flow path 28 on the outer surface of the fuel cell 11 when the fuel cell 11 is operated while introducing the cooling water, and the operation of the fuel cell 11 without introducing the cooling water. FIG. 6 is a diagram showing the temperature in the vicinity of the oxidant gas flow path 28 on the outer surface of the fuel cell 11 when it is done. Note that the temperatures in the vicinity of the oxidant gas flow path 28 on the outer surface of the fuel cell 11 are in the vicinity of the inlet of the oxidant gas flow path 28, near the center of the oxidant gas flow path 28, and in the oxidant gas flow path 28. Measurements were taken near the outlet.

  As shown in FIG. 4, the temperature change measured in the vicinity of the outlet of the oxidant gas channel 28 was more remarkable than the temperature change in the vicinity of the inlet and the center of the oxidant gas channel 28. Therefore, if a temperature abnormality of the fuel cell system 10 is detected based on the temperature measured in the vicinity of the outlet of the oxidant gas flow path 28, it is considered that the temperature abnormality can be detected quickly and reliably.

  FIG. 5 shows the state of the oxidant gas flow path 28 on the outer surface of the fuel cell 11 when the fuel cell 11 is operated while introducing the cooling water and then the introduction of the cooling water is stopped and the fuel cell 11 is operated. It is a figure which shows the time change of the temperature of the vicinity. Note that the temperatures in the vicinity of the oxidant gas flow path 28 on the outer surface of the fuel cell 11 are in the vicinity of the inlet of the oxidant gas flow path 28, near the center of the oxidant gas flow path 28, and in the oxidant gas flow path 28. Measurements were taken near the outlet.

  As shown in FIG. 5, the time rate of change of temperature measured in the vicinity of the outlet of the oxidant gas flow path 28 immediately after the introduction of the cooling water to the fuel cell is stopped near the inlet and the center of the oxidant gas flow path 28. It was more prominent than the time change rate of the nearby temperature. Therefore, if a temperature abnormality of the fuel cell system 10 is detected based on the temperature measured in the vicinity of the outlet of the oxidant gas flow path 28, it is considered that the temperature abnormality can be detected quickly and reliably.

  Next, a control method of the fuel cell system according to the embodiment of the present invention will be described.

  First, fuel gas, air, and cooling water are introduced into the fuel cell 11 to operate the fuel cell 11. Next, the battery surface temperature is measured by the temperature sensor 76 periodically, for example, every 10 seconds. The measured battery surface temperature data is sent to the system control unit 78. When the battery surface temperature data satisfies a predetermined condition, the system control unit 78 determines that the fuel cell system 11 is abnormal.

  Then, the electric load is cut off from the fuel cell 11 by the load control unit 102, the cooling water circulation pump 74 is stopped by the cooling water circulation pump control unit 100, and the introduction of the fuel gas to the fuel cell 11 is stopped by the fuel control unit 104, The air control unit 106 stops the introduction of air into the fuel cell 11.

  In addition, the order of each procedure of interruption | blocking of an electrical load, the stop of the cooling water circulation pump 74, the introduction stop of fuel gas, and an air introduction stop is set suitably. In addition, it is not always necessary to stop the operation of the entire fuel cell system 10, and only a part of the operation of the fuel cell system 10 may be stopped. Further, the operation of the system may be stopped by stopping the cooling water circulation pump 74 and / or interrupting the electric load.

  While the measured battery surface temperature does not satisfy the predetermined condition, the fuel cell system 10 is operated. If necessary, the cooling water circulation pump 74 is stopped, the electric load is shut off, the introduction of fuel gas is stopped, and the introduction of air is stopped, and the operation of the fuel cell system 10 is stopped.

  Next, the abnormality detection method for the fuel cell system according to the embodiment of the present invention will be described.

  First, fuel gas, air, and cooling water are introduced into the fuel cell 11 to operate the fuel cell 11. Next, the battery surface temperature is measured by the temperature sensor 76 periodically, for example, every 10 seconds. The measured battery surface temperature data is sent to the system control unit 78. When the battery surface temperature data satisfies a predetermined condition, it is determined that an abnormality has occurred in the fuel cell system 10.

  Next, the operation of the fuel cell system 10 is stopped. The fuel cell system 10 is shut down by performing each procedure of shutting down an electric load, stopping the cooling water circulation pump 74, stopping introduction of fuel gas, and stopping introduction of air in an appropriate order. Note that, depending on the state of occurrence of the abnormality, for example, when it is known that a certain part of the fuel cell system 10 is normal and the abnormality of another part can be repaired at an early stage, the normality of the fuel cell system 10 is achieved. The operation of only a part of the part may be stopped while the part is operated. Further, the operation of the system may be stopped by stopping the cooling water circulation pump 74 and / or interrupting the electric load. Next, the cause of the abnormality of the fuel cell system 10 is investigated in detail. Then, take measures corresponding to the cause of the abnormality.

  According to the results of the study by the inventors of the present application, since the majority of cases where the measured battery surface temperature satisfies a predetermined condition is abnormal in the cooling water introduction system, the measured battery surface temperature is When a predetermined condition is satisfied, it may be determined that an abnormality has occurred in the cooling water introduction system. In this case, the cooling water circulation pump 74 is first stopped.

  Further, the fuel cell system 10 is operated while the measured battery surface temperature does not satisfy the predetermined condition. Then, if necessary, the operation of the fuel cell system 10 is stopped by cutting off the electric load, stopping the cooling water circulation pump 74, stopping the introduction of fuel gas, and stopping the introduction of air.

  If the cooling water introduction system is not abnormal, the cooling water may be continuously introduced into the fuel cell 11 for a while after the operation of the fuel cell 11 is stopped. After the operation of the fuel cell 11 is stopped, the fuel gas passage 24 and the oxidant gas passage 28 of each cell of the fuel cell 11 can be uniformly cooled by continuing to introduce the cooling water into the fuel cell 11 for a while. it can. For this reason, the generation of condensed water is made uniform between the plurality of fuel gas passages 24 and between the plurality of oxidant gas passages 28, and the fuel gas and the oxidant gas are in the cell at the start of the next operation of the fuel cell 11. Uniformly supplied inside. As a result, the voltage at the start of the fuel cell 11 is stabilized.

  Further, the temperature in the vicinity of the cooling water outlet (A in FIG. 2) from which the cooling water is discharged from the cell stack 12 is measured together with the outer surface temperature of the fuel cell 11, and the temperature in the vicinity of these cooling water outlets (hereinafter referred to as “cooling water outlet”). , T1), an outer surface temperature (hereinafter referred to as T2), and a difference between T1 and T2 (T2−T1), an abnormal portion of the fuel cell system 10 can be estimated.

  That is, assuming that the temperature near the coolant outlet and the outer surface temperature during normal operation of the fuel cell 11 are Ts1 and Ts2, respectively, (1) When T1 is substantially the same as Ts1 and T2 is higher than Ts2 If the introduction of the cooling water to the fuel cell 11 is stopped, (2) T1 is higher than Ts1, T2 is higher than Ts2, and T2-T1 is Ts2-Ts1. In the case of substantially the same temperature, if the amount of cooling water introduced into the fuel cell 11 is reduced or if the fuel cell 11 is abnormally heated, (3) T1 is at a lower temperature than Ts1, and T2 Is lower than Ts2 and T2-T1 is approximately the same temperature as Ts2-Ts1, it can be estimated that the temperature of the cooling water introduced into the fuel cell 11 is abnormal.

  In the case of the above (1), one or more causes can be considered among the abnormality of the cooling water circulation pump 74, the clogging of the piping, the clogging of the filter 86, or the abnormality of the cooling water circulation pump control unit 100.

  In the case of (2) above, when it is estimated that the introduction amount of the cooling water to the fuel cell 11 is reduced, the discharge power of the cooling water circulation pump 74 is reduced, the piping is clogged, the filter 86 is clogged, or the cooling is performed. When one or more causes are considered among the abnormalities of the water circulation pump control unit 100 and it is estimated that the fuel cell 11 is abnormally heated, a decrease in the fuel introduction amount, a decrease in the humidification temperature of the fuel gas, an oxidant One or more causes can be considered among the decrease in the humidification temperature of the gas or the overcurrent of the fuel cell 11.

  In the case of (3) above, it is considered that the temperature control of the heat exchanger 80 is abnormal.

  Further, the temperature near the cooling water inlet (B in FIG. 2) at which the cooling water is introduced into the cell stack 12 (hereinafter referred to as T3) is measured together with T1 and T2, and T1, T2, T3, Based on T2-T1 and T3-T1, it is possible to estimate the abnormal part of the fuel cell system 10 in more detail. The temperature near the cooling water inlet during normal operation of the fuel cell 11 is Ts3.

  That is, in addition to the measurement result of (1) above, when T3 is substantially the same temperature as Ts3 and T1-T3 is substantially the same temperature as Ts1-Ts3, the introduction of the cooling water to the fuel cell 11 is prevented. If it is stopped, it can be estimated with higher accuracy.

  In addition to the measurement result of (2) above, when T3 is substantially the same temperature as Ts3 and T1-T3 is at a higher temperature than Ts1-Ts3, the amount of cooling water introduced into the fuel cell 11 is reduced. Or when the fuel cell 11 is abnormally heated, it can be estimated with higher accuracy.

  In addition to the measurement result of (3) above, when T3 is higher than Ts3 and T1-T3 is substantially the same temperature as Ts1-Ts3, the temperature of the cooling water introduced into the fuel cell 11 is abnormal. If there is, it can be estimated with higher accuracy.

  And if the abnormal location and the cause of abnormality of the fuel cell system 10 are estimated, measures according to various causes can be taken. For this reason, the necessity for exhaustively investigating various parts of the abnormality part and abnormality cause of the fuel cell system 10 is reduced.

  Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and various modifications such as design changes may be added based on the knowledge of those skilled in the art. Embodiments which are possible and which have been modified are also included in the scope of the present invention.

It is the cross-sectional schematic diagram which cut | disconnected the cell laminated body which concerns on this Embodiment in the surface parallel to the lamination direction of a cell. 1 is a schematic configuration diagram of a fuel cell system according to an embodiment. It is the external appearance schematic diagram which looked at the cell laminated body concerning this Embodiment from the diagonal direction. It is a figure which shows the temperature of the vicinity of the oxidizing gas flow path in the outer surface of the fuel cell which concerns on this Embodiment. It is a figure which shows the time change of the temperature of the vicinity of the oxidant gas flow path in the outer surface of a fuel cell when the fuel cell which concerns on this Embodiment is drive | operated.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Fuel cell system, 11 Fuel cell, 12 Cell laminated body, 14 MEA, 16 Solid polymer electrolyte membrane, 18 Anode, 20 Cathode, 22 Anode side plate, 24 Fuel gas flow path, 26 Cathode side plate, 28 Oxidant gas Flow path, 40 Fuel gas inlet header, 44 Fuel gas outlet header, 46 Oxidant gas inlet header, 50 Oxidant gas outlet header, 54 Coolant flow path, 56 Coolant outlet header, 74 Coolant circulation pump, 76 Temperature sensor, 78 System control unit, 80 heat exchanger, 82 fuel humidification tank, 84 air humidification tank, 86 filter, 88 fuel source, 90 air source, 100 cooling water circulation pump control unit, 102 load control unit, 104 fuel control unit, 106 air control Department.

Claims (7)

An anode side on which an electrolyte membrane, an anode provided on one surface of the electrolyte membrane, a membrane electrode assembly having a cathode provided on the other surface of the electrolyte membrane, and a fuel channel facing the anode are formed Three plates consisting of a plate, a cathode side plate in which an oxidant channel facing the cathode is formed, and a heat medium channel plate provided with a heat medium channel through which the heat medium flows, or a fuel flow Two bipolar plates each having a heat medium channel formed on the opposite surface of the surface on which the channel and the oxidant channel are formed, or heat on the surface opposite to the surface on which the fuel channel or the oxidant channel is formed. A cell product in which a plurality of cells each including any one of two plates including a bipolar plate and an anode side plate or a cathode side plate in which a medium flow path is formed are stacked. And a fuel cell comprising a body,
A heat medium supply means for introducing a heat medium into the heat medium flow path;
A temperature sensor that measures a temperature (T1) in the vicinity of a heat medium outlet from which the heat medium is discharged from the cell stack and a temperature (T2) of the outer surface of the fuel cell;
System abnormality detection means for determining that the system is abnormal when the temperatures T1 and T2 and the temperature difference T2-T1 measured by the temperature sensor satisfy predetermined conditions;
A fuel cell system that having a, the system abnormality detecting means, the temperature of the temperature and the outer surface of the heat medium near the outlet of the normal operation of the fuel cell, respectively Ts1 and Ts2, (1) T1 is Ts1 And when T2 is higher than Ts2, it is estimated that the introduction of the heat medium into the fuel cell is stopped,
(2) When T1 is at a higher temperature than Ts1, T2 is at a higher temperature than Ts2, and T2-T1 is substantially the same temperature as Ts2-Ts1, the amount of heat medium introduced into the fuel cell is reduced. Or the fuel cell is heating up abnormally,
(3) When T1 is a low temperature compared to Ts1, T2 is a low temperature compared to Ts2, and T2-T1 is substantially the same temperature as Ts2-Ts1, the temperature of the heat medium introduced into the fuel cell is abnormal. A fuel cell system characterized by being presumed to exist . The temperature sensor measures a temperature T3 in the vicinity of the heat medium inlet at which the heat medium is introduced into the cell stack, and the system abnormality detection means measures the temperature in the vicinity of the heat medium inlet during normal operation of the fuel cell as Ts.
3
(1) When T3 is substantially the same temperature as Ts3 and T1-T3 is substantially the same temperature as Ts1-Ts3, it is assumed that the introduction of the heat medium into the fuel cell is stopped,
(2) When T3 is substantially the same temperature as Ts3 and T1-T3 is at a higher temperature than Ts1-Ts3, the amount of heat medium introduced into the fuel cell is reduced, or the fuel cell generates abnormal heat. Guess that
(3) When T3 is higher than Ts3 and T1-T3 is substantially the same temperature as Ts1-Ts3, it is estimated that the temperature of the heat medium introduced into the fuel cell is abnormal. 1. The fuel cell system according to 1. The system abnormality detection means supplies the heat medium to stop introducing the heat medium from the heat medium supply means to the heat medium flow path when the temperature and temperature difference measured by the temperature sensor satisfy a predetermined condition. The system further comprises a control means and / or a load control means for cutting off the connection between the fuel cell and an electric load supplied with electric power from the fuel cell, and a system control means for stopping the operation of the system. The fuel cell system according to claim 1 or 2 . The fuel cell system of claim 1, wherein the temperature sensor is a temperature sensor of non-contact type. An anode side on which an electrolyte membrane, an anode provided on one surface of the electrolyte membrane, a membrane electrode assembly having a cathode provided on the other surface of the electrolyte membrane, and a fuel channel facing the anode are formed Three plates consisting of a plate, a cathode side plate in which an oxidant channel facing the cathode is formed, and a heat medium channel plate provided with a heat medium channel through which the heat medium flows, or a fuel flow Two bipolar plates each having a heat medium channel formed on the opposite surface of the surface on which the channel and the oxidant channel are formed, or heat on the surface opposite to the surface on which the fuel channel or the oxidant channel is formed. A cell product in which a plurality of cells each including any one of two plates including a bipolar plate and an anode side plate or a cathode side plate in which a medium flow path is formed are stacked. Introducing a fuel gas to the fuel passage of the fuel cell, including the body,
  Introducing an oxidant gas into the oxidant flow path;
  Introducing a heat medium into the heat medium flow path;
  When fuel gas, oxidant gas, and heat medium are introduced into the fuel cell, the temperature (T1) near the heat medium outlet at which the heat medium is discharged from the cell stack, and the outside of the fuel cell Measuring the surface temperature (T2);
  The temperature near the heat medium outlet and the temperature of the outer surface during normal operation of the fuel cell are Ts1 and Ts2, respectively.
When any of the following conditions (1) to (3) is satisfied:
(1) When T3 is substantially the same temperature as Ts3 and T1-T3 is substantially the same temperature as Ts1-Ts3,
(2) When T3 is substantially the same temperature as Ts3 and T1-T3 is hotter than Ts1-Ts3,
(3) When T3 is at a higher temperature than Ts3 and T1-T3 is substantially the same temperature as Ts1-Ts3,
Stopping the operation of the system, comprising stopping the introduction of the heat medium into the heat medium flow path and / or cutting off the connection between the fuel cell and an electric load supplied with electric power from the fuel cell; ,
  A control method for a fuel cell system comprising: An electrolyte membrane, an anode provided on one surface of the electrolyte membrane, and the other surface of the electrolyte membrane;
A membrane electrode assembly having a cathode provided; an anode side plate having a fuel flow path facing the anode; a cathode side plate having an oxidant flow path facing the cathode; and a heating medium. The heat medium flow path was formed on the opposite side of the surface on which the three heat medium flow path plates provided with the circulating heat medium flow path or the fuel flow path and the oxidant flow path were formed. 2 bipolar plates, or two bipolar plates, or one bipolar plate having a heat medium flow path formed on the opposite side of the surface on which the fuel flow path or the oxidant flow path is formed, and an anode side plate or a cathode side plate 2 Introducing a fuel gas into the fuel flow path of the fuel cell including a cell stack in which a plurality of cells each including any one of the plates are stacked;
  Introducing an oxidant gas into the oxidant flow path;
  Introducing a heat medium into the heat medium flow path;
  When fuel gas, oxidant gas, and heat medium are introduced into the fuel cell, the temperature (T1) near the heat medium outlet at which the heat medium is discharged from the cell stack, and the outside of the fuel cell Measuring the surface temperature (T2);
The temperature near the heat medium outlet and the temperature of the outer surface during normal operation of the fuel cell are Ts1 and Ts2, respectively.
When any of the following conditions (1) to (3) is satisfied:
(1) When T3 is substantially the same temperature as Ts3 and T1-T3 is substantially the same temperature as Ts1-Ts3,
(2) When T3 is substantially the same temperature as Ts3 and T1-T3 is hotter than Ts1-Ts3,
(3) When T3 is at a higher temperature than Ts3 and T1-T3 is substantially the same temperature as Ts1-Ts3,
Determining the abnormality of the fuel cell system and / or determining the abnormality of the temperature of the heat medium;
  An abnormality detection method for a fuel cell system, comprising: 7. The fuel cell system abnormality detection method according to claim 6, wherein the step of determining an abnormality of the fuel cell system is a step of determining that an abnormality has occurred in the heat medium introduction system.

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