JP2005285686A - Fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell system capable of directly detecting an operation state of a control valve and efficiently operating various control valves according to the detection result.
SOLUTION: A fuel cell system 1 according to the present invention includes a fuel cell 10, an impurity discharge channel 23 for circulating impurities discharged from the fuel cell 10, and a first electromagnetic for opening and closing the impurity discharge channel 23. A control unit 41 that determines the operating state of the first electromagnetic valve 27 based on a resistance value between the valve 27 and the valve seat 231 that receives the valve body 277 and the valve body 277 of the first electromagnetic valve 27; Is provided.
[Selection] Figure 1

Description

  The present invention relates to a fuel cell system, and more particularly to a fuel cell system in which a control valve is disposed on a gas flow path of a reaction gas of the fuel cell.

  Conventionally, in a fuel cell system using a so-called polymer electrolyte fuel cell, the water provided in the gas discharged from the fuel cell is frozen and the valve provided on the gas flow path is not operated. As a result, the fuel cell There is a problem that a malfunction occurs in the operation of the system. Therefore, in recent years, a technique for solving such a problem associated with freezing of the valve has been proposed.

For example, Japanese Patent Laid-Open No. 2002-313389 (Patent Document 1) discloses a technique for heating a valve in order to prevent the valve from freezing, and specifically, an oxidant gas adiabatically compressed in a fuel cell. Heat exchange between the oxidant gas supply means for supplying the oxidant gas, the control valve provided on the gas flow path of the exhaust reaction gas discharged from the fuel cell, and the oxidant gas supplied from the oxidant gas supply means Thus, a fuel cell system including a control valve heating means for heating the control valve is disclosed.
JP 2002-313389 A

  However, in a conventional fuel cell system as described in JP-A-2002-313389, a control valve provided on a gas flow path is housed in a warm-up box, and an air compressor is placed in the warm-up box. The control valve is heated from the outside by introducing hot air that is adiabatically compressed. In other words, since the control valve stored in the warm-up box is indirectly heated by raising the temperature in the warm-up box, it takes time to heat the control valve and energy consumption tends to increase. Is not efficient.

  Further, such a conventional fuel cell system determines that the control valve is frozen when the outside air temperature is equal to or lower than a predetermined temperature. However, the operating state of the control valve varies depending on the gas flow path, the structure of the control valve, the location of the control valve, the operating state of the fuel cell system, etc. The conventional method for indirectly determining is likely to lack accuracy.

  An object of the present invention is to improve such a conventional fuel cell system, and directly detect the operating state of a control valve and efficiently operate various control valves according to the detection result. An object of the present invention is to provide a fuel cell system capable of satisfying the requirements.

  A fuel cell system according to the present invention for solving the above-described problems includes a fuel cell, a gas flow path that is connected to an inlet / outlet of the fuel cell and allows reaction gas to flow, and an on-off valve that opens and closes the gas flow path. Determining means for determining an operating state of the on-off valve based on a resistance value between a valve body of the on-off valve and a valve seat receiving the valve body.

  According to this configuration, the operating state of the on-off valve can be determined based on the resistance value between the valve body of the on-off valve and the valve seat. Therefore, since the operating state of the on-off valve can be directly detected, it is possible to more accurately detect the frozen state of each on-off valve.

  The gas flow path includes at least one of a supply gas passage through which a reaction gas (fuel gas, oxidizing gas) flows through the fuel cell and an exhaust gas passage through which the reaction gas discharged from the fuel cell flows. The on-off valve according to the present invention is provided in the gas flow path.

  The fuel cell system according to the present invention includes a voltage applying unit that applies a voltage between the valve body and the valve seat, and a resistance value measuring unit that measures a resistance value between the valve body and the valve seat. The determination means may determine the operating state of the on-off valve based on the resistance value measured by the resistance value measurement means.

  Further, the determination means of the fuel cell system according to the present invention is configured such that when the resistance value between the valve body and the valve seat is equal to or greater than a preset threshold, the valve body of the on-off valve and the valve seat The voltage applying means may be controlled so that a high voltage is applied between them.

  According to this configuration, by applying a high voltage directly between the valve body of the on-off valve and the valve seat, the frozen part of the on-off valve can be thawed, so by increasing the temperature in the warm-up box This is more efficient than when the control valve housed in the warm air box is indirectly heated. In addition, since the voltage application means can be used for both resistance value measurement and thawing of the frozen part, the design is also effective.

  The determination means of the fuel cell system according to the present invention applies a high voltage between the valve body and the valve seat until a resistance value between the valve body and the valve seat becomes smaller than the threshold value. As described above, the voltage applying means may be controlled.

  According to this configuration, since a high voltage can be applied until the valve body and the valve seat are in a conductive state, the function of the on-off valve can be reliably recovered.

  The determination means of the fuel cell system according to the present invention controls the open / close valve to perform an open / close operation when a resistance value between the valve body and the valve seat is not less than a preset threshold value. May be.

  According to this configuration, since the frozen part can be thawed by the opening / closing operation of the opening / closing valve, it is possible to appropriately operate the opening / closing valve while suppressing energy consumption.

  The determination means of the fuel cell system according to the present invention controls the open / close valve to perform an open / close operation when a resistance value between the valve body and the valve seat is not less than a preset threshold value. The voltage applying means may be controlled so that a voltage is applied between the valve body and the valve seat when a predetermined condition is satisfied after the opening / closing operation by the opening / closing valve.

  According to this configuration, since the frozen part of the on-off valve can be thawed by performing the opening / closing operation of the on-off valve and the voltage application stepwise, for example, when the frozen part is thawed by the opening / closing operation of the on-off valve On the other hand, the application of voltage can be omitted, but if the frozen part is not thawed by the opening and closing operation of the on-off valve, it can be thawed reliably by the application of voltage, so that the on-off valve can be normally started more efficiently. It becomes possible to migrate.

  Further, the determination means of the fuel cell system according to the present invention is configured such that the operating state of the on-off valve is based on a resistance value between the valve body and the valve seat when the outside air temperature is equal to or lower than a preset temperature. May be determined.

  Further, a control method of a fuel cell system according to the present invention is a control method of a fuel cell system provided with an on-off valve for opening and closing a gas flow path connected to an inlet / outlet of a fuel cell and through which a reaction gas flows. Whether a resistance value between the valve body and the valve seat is measured by applying a voltage between the valve body and the valve seat of the on-off valve, and the measured resistance value is equal to or greater than a preset threshold value A first step of determining whether the resistance value is greater than or equal to the threshold value, a second step of controlling the on / off valve to perform an on / off operation when it is determined that the resistance value is greater than or equal to the threshold value, A third step of measuring a resistance value between the seat and determining whether or not the measured resistance value is smaller than the threshold value, and when it is determined that the resistance value is smaller than the threshold value, Control to apply a voltage between the valve body and the valve seat Includes a step, a.

  According to the present invention, it is possible to provide a fuel cell system capable of directly detecting the operating state of the on-off valve and efficiently operating various control valves according to the detection result.

  Hereinafter, a fuel cell system according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings. Note that the present invention is not limited to the following embodiments, and can be applied with various modifications.

  First, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram of a fuel cell system according to the present embodiment. FIG. 2 is a cross-sectional view of the on-off valve disposed on the gas flow path of the fuel cell system shown in FIG. FIG. 3 is a diagram showing the relationship between the open / close state of the on-off valve shown in FIG. 1 and the resistance value. 4 and 5 are flowcharts showing the flow of processing by the control unit in the fuel cell system shown in FIG.

  As shown in FIG. 1, the fuel cell system 1 according to the present embodiment is supplied with hydrogen gas supplied from a hydrogen gas piping system 20 and oxygen gas (air) supplied from an oxygen gas piping system 30. And a solid polymer electrolyte fuel cell (stack) 10 for generating electric power. The fuel cell system 1 includes an electrical control system 40 having a microcomputer.

  The fuel cell 10 is formed by sandwiching a solid polymer electrolyte membrane made of, for example, a solid polymer ion exchange membrane between an anode (hydrogen electrode) and a cathode (air electrode) from both sides and further sandwiching the outside with a pair of separators. It is configured by stacking a large number of the formed cells. When hydrogen gas and oxygen gas are supplied to each cell, the fuel cell 10 generates electricity by an electrochemical reaction. For example, when the fuel cell system 1 is mounted on an automobile, the generated electric power is supplied to a motor or the like that is a driving source of the automobile.

  The hydrogen gas piping system 20 includes a hydrogen gas supply channel 21 that supplies hydrogen gas to the fuel cell 10, and a hydrogen off gas that pumps the hydrogen off gas discharged from the fuel cell 10 to the hydrogen gas supply channel 21 by a pump 26. A circulation passage 22 and an impurity discharge passage 23 branched from the hydrogen off-gas circulation passage 22 are provided.

  The hydrogen gas supply passage 21 is provided with a hydrogen supply source 24 such as a tank that stores high-pressure hydrogen gas, and a pressure regulating valve 25 that adjusts the pressure of the hydrogen gas supplied from the hydrogen supply source 24. Yes. Further, the impurity discharge passage 23 is provided with a first electromagnetic valve 27 as an electromagnetic on-off valve (hereinafter referred to as “electromagnetic valve”) for opening and closing the impurity discharge passage 23. By opening the first electromagnetic valve 27, impurities in the hydrogen off-gas are discharged.

  On the other hand, in the oxygen gas piping system 30, the oxygen gas supply flow path 32 that supplies the oxygen gas humidified by the humidifier 31 to the fuel cell 10 and the oxygen off-gas discharged from the fuel cell 10 are guided to the humidifier 9. For this purpose, an oxygen off-gas passage 33 for supplying oxygen and an off-gas passage 34 for introducing oxygen off-gas from the humidifier 31 to the combustor (not shown) are provided.

  The oxygen gas supply channel 32 is provided with a compressor 36 that takes in and compresses oxygen gas in the atmosphere, and the oxygen gas compressed by the compressor 36 is pumped to the humidifier 31. The oxygen off-gas exhaust passage 34 is provided with a second electromagnetic valve 35 as an electromagnetic valve for opening and closing the oxygen off-gas exhaust passage 34. The pressure of the oxygen gas supply flow path is adjusted by the opening degree or opening / closing interval of the second electromagnetic valve 35.

  Here, the structure of the 1st electromagnetic valve 27 and the 2nd electromagnetic valve 35 is demonstrated using FIG. Since the first electromagnetic valve 27 and the second electromagnetic valve 35 have substantially the same configuration, the first electromagnetic valve 27 will be described for convenience.

  As shown in FIG. 2, the first electromagnetic valve 27 includes a main body 271, a magnetism generating coil 272 provided in the main body 271, a magnet 273 disposed so as to be positioned in a hollow portion of the coil 272, and a magnet 273. The spring 276 provided on the opposite side of the flow path 23 (upper side in FIG. 2), the shaft 274 extending to the flow path side (lower side in FIG. 2) of the magnet 273, and the shaft 274 fixed to the flow path 273 side. For example, a cylindrical support member 275 that movably supports the valve body 277, the magnet 273, and the shaft 274 is provided.

  The first electromagnetic valve 27 can basically adopt a conventional configuration, but in this embodiment, a functional circuit for applying a high voltage is connected to the valve body 277 and the valve seat 231 as described later. Therefore, it is necessary to employ an insulating member for the support member 275. In this respect, the first electromagnetic valve 27 of the present embodiment is different from the conventional one. As the insulating member, various materials having substantially insulating properties can be applied. For example, rubber alone or a resin material can be used.

  In the impurity discharge flow path 23 in which the first electromagnetic valve 27 is disposed, an opening 234 that communicates with the inside of the first electromagnetic valve 27 is formed at a position where the first electromagnetic valve 27 is provided. . A valve seat 231 for closing the impurity discharge channel 23 by contacting the valve body 277 of the first electromagnetic valve 27 is formed at a position where the opening 234 of the impurity discharge channel 23 is formed. ing.

  The valve body 277 of the first electromagnetic valve 27 moves in the direction away from the impurity discharge flow path 23 by energizing the coil 272, and the valve body 277 moves in the same direction. The body 277 is separated from the valve seat 231. As a result, the flow path circulates and the first electromagnetic valve is in an open state (non-conductive state). On the other hand, when the magnet 273 moves (lowers) toward the impurity discharge channel 23 by stopping energization of the coil 272, the valve body 277 moves in the same direction, and the valve body 277 contacts the valve seat 231. . As a result, the flow path is blocked and the first electromagnetic valve 27 is closed (conductive state).

  In addition, the first electromagnetic valve 27 according to the present embodiment directly detects the operating state of the on-off valve and realizes a function necessary for operating the on-off valve efficiently according to the detection result. The first functional circuit 42 is connected.

  The first functional circuit 42 is formed, for example, by connecting any two points for applying a voltage between the valve body 277 and the valve seat 231 with the first conducting wire 421 and the second conducting wire 422. By inserting a power source 423 that can supply electric energy to the first functional circuit 26 and a resistance value detector 424 that detects a resistance value, a voltage is directly applied between the valve body 277 and the valve seat 231. It is configured so that it can be applied or a change in resistance value can be detected. The first functional circuit 42 is configured to be able to input and output control signals and the like to the control unit 41.

  The resistance value between the valve body 277 and the valve seat 231 varies depending on the open / close state and the frozen state of the first electromagnetic valve 27. Here, the relationship between the open / close state and the frozen state of the valve and the resistance value change between the valve body and the valve seat will be described with reference to FIG.

  As shown in FIG. 3A, when the first electromagnetic valve 27 is in an open state (a state in which the valve body 277 is separated from the valve seat 231), it is between the valve body 277 and the valve seat 231. When the resistance value is ∞ (infinite) and the first electromagnetic valve 27 is in a normal closed state (a state in which the valve body 277 is in contact with the valve seat 231) as shown in FIG. Is in a conductive state, the resistance value is 0 (resistance on the wiring is not taken into consideration). On the other hand, the first electromagnetic valve 27 is in a state where foreign matter is caught between the valve body 277 and the valve seat 231 or the valve body 277 and the valve seat 231 are fixed by freezing (normal valve closing). In the non-state), the non-conductive state is established, and the resistance value A corresponding to the state is measured.

  As described above, the resistance value between the valve body 277 and the valve seat 231 (the presence or absence of conduction) changes depending on whether the first electromagnetic valve 27 is opened or closed, or the frozen state. By receiving an input from the resistance value detector 424 toward the control unit 41, the control unit 41 detects that the first electromagnetic valve 27 is in a frozen state or that the frozen state is released. Can do.

  Next, returning to FIG. 1, the control system 40 will be described. The control system 40 includes the first functional circuit 42 and the second functional circuit 43, which correspond to the electromagnetic valves provided on the gas flow path of the reaction gas of the fuel cell system 1, and the first and second functional circuits. And a control unit 41 connected to the functional circuits 42 and 43.

  The control unit 41 is configured as a logic circuit centered on a microcomputer and is not shown. For example, the control unit 41 executes a predetermined calculation according to a preset control program, and executes various calculation processes by the CPU. A ROM in which control programs and control data necessary for the above are stored in advance, and a RAM in which various data necessary for executing various arithmetic processes by the CPU are temporarily read and written.

  In addition, a voltage is applied to the first and second electromagnetic valves 27 and 35 in accordance with an input processing circuit for inputting output signals from the first and second functional circuits 42 and 43, and a calculation result in the CPU. Output processing circuits for outputting control signals to the first and second functional circuits 42 and 43 and outputting opening / closing signals to the first and second electromagnetic valves 27 and 35 are provided.

  According to such a configuration, for example, the resistance value of the first electromagnetic valve 27 is obtained from the output signal from the first functional circuit 42, and the operating state of the first electromagnetic valve 27, that is, the operation state of the first electromagnetic valve 27, that is, The frozen state is determined, and according to the determination result, opening / closing control of the first electromagnetic valve 27 and voltage application to the first electromagnetic valve 27 are performed, so that the frozen state of the first electromagnetic valve 27 is determined. Can be eliminated.

  Next, the flow of processing related to the determination of the frozen state of the electromagnetic valve and the thawing by the control unit 41 will be described in detail with reference to the flowcharts of FIGS. Note that the processing of these flowcharts can be performed on any open / close valve that is provided in the exhaust gas flow path of the fuel cell system and opens and closes the exhaust gas flow path. A case where the electromagnetic valve 27 is a control target will be described.

  When the control unit 41 (CPU) detects a start command of the fuel cell system 1 (STEP 101: Yes), the control unit 41 (CPU) measures the outside air temperature at that time by a predetermined temperature sensor that detects the outside air temperature connected to the control unit 41. (STEP102). In addition, when the fuel cell system 1 according to the present embodiment is mounted on an automobile, when it is detected that the ignition key of the vehicle is turned on, the start command of the fuel cell system 1 is detected. To do.

  Next, the control unit 41 provides a control signal (open / close signal) for controlling the valve from the open state to the closed state with respect to the electromagnetic valve (that is, the first electromagnetic valve 27) that is the target of the operation state determination. By outputting, the valve is closed (STEP 103). In the specification, when the state of the valve at the start of the fuel cell system 1 is a closed state, the control signal can be omitted.

  Next, the control unit 41 measures the resistance value between the valve body 277 and the valve seat 231 of the first electromagnetic valve 27 (STEP 104). The resistance value is measured, for example, by applying a voltage (measurement voltage) supplied from the power source 423 between the valve body 277 of the first electromagnetic valve 27 and the valve seat 231 receiving the valve element 277 for a predetermined time. This can be performed by outputting a control signal (measurement instruction signal) to the first functional circuit 42. In addition, as long as it is a value according to the pressure | voltage resistance of the apparatus connected to the 1st functional circuit 42, the arbitrary values according to a specification can be set to the voltage for a measurement.

  When the resistance value as the measurement result is input from the first functional circuit 42, the control unit 41 determines the operating state of the first electromagnetic valve 27 based on the resistance value. The determination of the operating state can be performed, for example, by setting a predetermined threshold value in advance and determining whether or not the input resistance value is greater than or equal to the set threshold value (set threshold value) (STEP 105). .

  If the determination result is affirmative, that is, if the resistance value is greater than or equal to a set threshold value (Yes in STEP 105), then whether or not the outside air temperature measured in STEP 102 is equal to or lower than a preset set temperature. Determine (STEP 106). This is for avoiding that the thawing process is performed in the frozen state when it is determined that the resistance value is equal to or greater than the set threshold due to the presence of foreign matters not related to freezing. The set temperature is set in advance to a temperature at which moisture in the exhaust gas freezes and can affect the electromagnetic valve to be controlled.

  When the determination result is affirmative, that is, when it is determined that the outside air temperature is equal to or lower than the set temperature (YES in STEP 106), the control unit 41 considers that the first electromagnetic valve 27 is in a frozen state, and is in a frozen state. The release processing of is started.

  Here, the thawing process according to the present embodiment includes a first thawing process that performs thawing by opening and closing an electromagnetic valve, and a second thawing process that performs thawing by directly applying a voltage to the electromagnetic valve. These are configured to be executed in combination. As a combination of the first thawing process and the second thawing process, for example, a case where these are executed sequentially or a case where they are executed alternately can be considered. Here, the former will be described as an example.

  First, the control unit 41 outputs a control signal (open / close signal) to the first electromagnetic valve 27 so as to repeat the open / close operation of the valve a predetermined number of times (STEP 107).

  When the control signal output from the control unit 41 is input, the first electromagnetic valve 27 performs a valve opening operation and a valve closing operation based on the control signal. Depending on the frozen state of the valve, the outside air temperature at the time of the release operation, etc., the ice attached to the valve body and the valve seat is peeled off and crushed by the opening and closing operation of the valve, so that the frozen part can be thawed.

  After outputting the control signal, the control unit 41 determines whether or not the frozen part has been thawed. For example, the frozen portion is determined by measuring again the resistance value between the valve body and the valve seat when the valve is closed (STEP 108), and determining whether or not the measured resistance value is smaller than a set threshold value. (STEP 109).

  If the determination result is affirmative, that is, if the resistance value is smaller than the set threshold value, it is considered that the frozen part has been thawed and the process returns to normal activation (STEP 113). On the other hand, if the determination result is negative, that is, if the resistance value is greater than or equal to the set threshold, the thawing process is continued assuming that the frozen portion has not been thawed yet.

  Here, as described above, the thawing process according to the present embodiment includes a first thawing process that performs thawing by opening and closing a valve, a second thawing process that performs thawing by directly applying a voltage to the valve, Are executed in order. Therefore, the control unit 41 determines whether or not to proceed to the second thawing process in which thawing is performed by directly applying a voltage to the valve when continuing the thawing process (STEP 111).

  The determination as to whether or not to proceed to the second thawing process can be made based on, for example, a predetermined condition that takes into account the number of opening and closing of the valve, the outside air temperature, the resistance value measured in STEP 108, and the like. Here, as an example, the determination is made based on whether or not the number of opening and closing of the valve is equal to or greater than a predetermined number of times (set number of opening and closing) (STEP 111).

  If the determination result is negative, that is, if the number of opening / closing of the valve is not equal to or greater than the set number of opening / closing, the process returns to STEP 107 to continue the thawing process by the valve opening / closing operation (No in STEP 111). On the other hand, if the determination result is affirmative, that is, if the number of opening and closing of the valve is greater than or equal to the set number, the thawing process by stopping the valve opening and closing operation is stopped and thawing is performed by directly applying voltage to the valve. 2 (Yes in STEP 111).

  Next, the flow of the second thawing process for performing thawing by directly applying a voltage to the valve will be described with reference to FIG. The control unit 41 applies a high voltage (heating voltage) supplied from the power source 423 between the valve body 277 and the valve seat 231 of the first electromagnetic valve 27 to the first functional circuit 42 for a predetermined time. A control signal (heating instruction signal) is output (STEP 114).

  The heating voltage is a value according to the withstand voltage of the device connected to the first functional circuit 42, and is a value that can cause arc discharge between the valve body 277 and the valve seat 231. It is possible to set an arbitrary value according to.

  When the heating voltage is applied, the control unit 41 measures the resistance value between the valve element 277 and the valve seat 231 again (STEP 115), and determines whether or not the measurement result is smaller than the set threshold value (STEP 116).

  If the determination result is affirmative, that is, if the resistance value is smaller than the set threshold value (Yes in STEP 116), it is considered that the frozen portion has been thawed and the process returns to normal activation (STEP 117). On the other hand, if the determination result is negative, that is, if the resistance value is greater than the second threshold (No in STEP 116), it is determined that the frozen part has not been thawed and the process returns to STEP 114 to continue the thawing process. .

  According to STEP 114 to STEP 116, the control unit 41 repeats application of a high voltage to the valve body and the valve seat until the resistance value becomes smaller than the set threshold value, so that the frozen portion of the valve can be surely thawed. .

  According to the above, with respect to the electromagnetic valve for opening and closing the exhaust gas flow path, a voltage is directly applied between the valve seat and the valve body to measure the resistance value between the valve seat and the valve body. When the engine is frozen, voltage is directly applied between the valve seat and the valve body to eliminate the freeze. As a result, advantageous effects can be obtained in the design and development of the fuel cell system.

  Further, according to the above configuration, since the frozen part is thawed by directly heating the valve body and the valve seat, that is, the frozen part, the frozen part of the valve can be reduced by increasing the temperature around the valve. Compared with the case of thawing, etc., the frozen site can be thawed efficiently in a short time.

  In addition, since the frozen state of the valve is judged by both the resistance value between the valve seat and the valve body and the outside air temperature, foreign matter biting due to causes other than freezing etc. (such as wear powder present in the fluid biting) In such a case, it is possible to control so that the decompression process is not performed.

  Also, if it is determined that it is in a frozen state, thawing by opening and closing the valve and thawing by heating the valve are performed in combination, so that the frozen part can be efficiently thawed to restore the function of the valve and the fuel cell system. It becomes possible to make it. For example, when the frozen state is light, the frozen part can be thawed only by opening and closing the valve, so that energy consumption due to heating can be avoided. Even if the frozen part cannot be thawed only by opening and closing the valve, the thawed part is heated, so that the frozen part can be surely thawed and the function of the valve can be exhibited appropriately.

  Further, when the resistance value becomes smaller than the set threshold value, the thawing process is stopped and the normal activation is resumed, so that the opening / closing and heating of the valve are not repeated.

(Other embodiments)
As mentioned above, although this invention was demonstrated using suitable embodiment, this invention is not limited to said embodiment. Those skilled in the art can make appropriate modifications or improvements based on the contents disclosed herein without departing from the scope of the present invention. Such changes or improvements are also included in the present invention. For example, each step in the flowchart (including a partial step to which no code is assigned) can be executed in any order or in parallel within a range that does not contradict the processing contents.

  (1) In the above embodiment, the case where the opening / closing operation of the valve and the heating of the valve are performed stepwise when it is determined that the electromagnetic valve is in the frozen state has been described. However, the present invention is not limited to this. I can't. For example, the frozen portion thawing process may be configured to execute only one of the valve opening / closing operation and the valve heating, or may be configured to add another thawing process thereto.

  Moreover, you may comprise so that it may determine whether the thawing | decompression process which should be performed is employ | adopted according to conditions, such as measured resistance value and external temperature. For example, when the resistance value is high and the outside air temperature is low, it is considered that the frozen part is unlikely to be thawed depending on the opening / closing operation of the valve. Therefore, the valve may be heated without performing the opening / closing operation of the valve. Good. In addition, when the resistance value is low and the outside air temperature is high, it is considered that the frozen part can be thawed only by the opening and closing operation of the valve. Control may be made so that the opening and closing operation of the valve is repeated until the is thawed.

  (2) In the above embodiment, the case where the operation state of the valve is determined at the start of the fuel cell system 1 has been described. However, the determination is not limited to the start of the start, and at the time of operation of the fuel cell, In particular, it can be arbitrarily executed at the time of low load (vs. power generation) or intermittent operation.

  (3) In the above embodiment, the case where the voltage is supplied from the secondary battery of the fuel cell system 1 has been described. However, when the fuel cell 10 is in a state where the voltage can be supplied, the fuel cell 10 It is also possible to configure so as to supply a voltage from

(4) In the above-described embodiment, the first electromagnetic valve 35 and the oxygen off-gas exhaust channel 34 disposed in the hydrogen off-gas exhaust channel 15 are disposed as the electromagnetic valves for determining the operating state. Although the second electromagnetic valve 27 has been described, the present invention can be similarly applied to other electromagnetic valves disposed on a flow path through which a gas containing water vapor is circulated.
(5) In the above embodiment, the case where the operating state of the valve is determined by measuring the resistance value by applying a voltage between the valve body and the valve seat has been described. By measuring the torque between the valve seats, the operating state between the valve body and the valve seat can also be determined. For example, when ice is caught between the valve body and the valve seat, the valve easily rotates due to the presence of the ice. On the other hand, when frictional heat is generated by the rotation of the valve, as a result of the thawing of ice, the rotation of the valve becomes slower as the thawing proceeds.

  Specifically, the valve is rotated by a predetermined driving means such as a motor, the torque in this case is detected by a sensor or the like, and the frozen state of the valve is determined by comparing the detected torque with a predetermined threshold value. . When the torque is smaller than the threshold value, it is regarded as a frozen state, and the rotation operation of the valve is continued. When the torque is equal to or greater than the threshold value, it is regarded as being thawed and the rotation operation is terminated.

According to this configuration, the operating state of the valve can be directly confirmed.
(6) Further, the electromagnetic valve can be applied to an electromagnetic valve whose opening degree can be changed linearly and an electromagnetic valve whose opening degree can be changed by a stepper motor.

It is a block diagram which shows the principal part of the fuel cell system which concerns on this Embodiment. It is sectional drawing of the on-off valve arrange | positioned on the gas flow path of the fuel cell system shown in FIG. It is a figure which shows the relationship between the operating state of the 1st electromagnetic valve shown in FIG. 1, and the resistance value change between a valve body and a valve seat. It is a flowchart which shows the flow of the process by the control unit 41 shown in FIG. It is a flowchart which shows the flow of the process by the control unit 41 shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell system 10 Fuel cell 20 Hydrogen gas piping system 21 Hydrogen gas supply flow path 22 Hydrogen off-gas circulation flow path 23 Impurity discharge flow path 24 Hydrogen supply source 25 Pressure regulating valve 26 Hydrogen pump 27 First electromagnetic valve (open / close valve)
30 Oxygen gas piping system 31 Humidifier 32 Oxygen gas supply channel 33 Oxygen off gas channel 34 Oxygen off gas exhaust channel 35 Second electromagnetic valve (open / close valve)
36 Compressor 40 Control system 41 Control unit 42 1st functional circuit 43 2nd functional circuit 421 1st conducting wire 422 2nd conducting wire 423 Power supply 424 Resistance detector

Claims (8)

A fuel cell;
A gas flow path connected to the inlet / outlet of the fuel cell to flow the reaction gas;
An on-off valve for opening and closing the gas flow path;
Determining means for determining an operating state of the on-off valve based on a resistance value between a valve body of the on-off valve and a valve seat receiving the valve body;
A fuel cell system comprising: Voltage applying means for applying a voltage between the valve body and the valve seat;
A resistance value measuring means for measuring a resistance value between the valve body and the valve seat,
The fuel cell system according to claim 1, wherein the determination unit determines an operating state of the on-off valve based on a resistance value measured by the resistance value measurement unit. The determination means includes
When the resistance value between the valve body and the valve seat is greater than or equal to a preset threshold value, the voltage applying means is configured to apply a high voltage between the valve body and the valve seat of the on-off valve. The fuel cell system according to claim 2 to be controlled. The determination means includes
The voltage application unit is controlled to apply a high voltage between the valve body and the valve seat until a resistance value between the valve body and the valve seat becomes smaller than the threshold value. Fuel cell system. The determination means includes
The fuel according to any one of claims 1 to 4, wherein when the resistance value between the valve body and the valve seat is equal to or greater than a preset threshold value, the on-off valve is controlled to perform an opening / closing operation. Battery system. The determination means includes
When the resistance value between the valve body and the valve seat is equal to or greater than a preset threshold value, the on-off valve is controlled to perform an opening / closing operation, and a predetermined condition is satisfied after the opening / closing operation by the on-off valve. 6. The fuel cell system according to claim 1, wherein the voltage application unit is controlled to apply a voltage between the valve body and the valve seat.   The determination means determines an operating state of the on-off valve based on a resistance value between the valve body and a valve seat when an outside air temperature is equal to or lower than a preset temperature. The fuel cell system according to claim 1. A control method for a fuel cell system comprising an on-off valve for opening and closing a gas flow path connected to an inlet / outlet of a fuel cell and through which a reaction gas flows.
Whether a resistance value between the valve body and the valve seat is measured by applying a voltage between the valve body and the valve seat of the on-off valve, and the measured resistance value is equal to or greater than a preset threshold value A first step of determining whether or not;
A second step of controlling the open / close valve to perform an open / close operation when it is determined that the resistance value is equal to or greater than the threshold;
A third step of measuring a resistance value between the valve body and the valve seat of the on-off valve, and determining whether the measured resistance value is smaller than the threshold value;
A fourth step of controlling to apply a voltage between the valve body and the valve seat when it is determined that the resistance value is smaller than the threshold;
A control method for a fuel cell system comprising:

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