JP2009140748A - Fuel cell system, and control method of fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system and a control method of the fuel system, capable of suppressing the morphology change of a catalyst and shortening the stop processing time upon stopping power generation of a fuel cell. <P>SOLUTION: A fuel cell system (300) is equipped with a control means (200) conducting at least one of: a control which compares the power generation stop time acquired with a time acquisition means with the predetermined prescribed time, and when the power generation stop time acquired with the time acquisition means is equal to or shorter than the prescribed time, controls a pressure adjusting means so as to increase the pressure of fuel gas in a fuel cell and controls a power generation control means so as to stop the power generation of the fuel cell; and a control which when the power generation stop time is longer than the prescribed time, controls the pressure adjusting means so as to decrease the pressure of fuel gas in the fuel cell and controls the power generation control means so as to continue the power generation of the fuel cell. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel cell system including a fuel cell and a control method for the fuel cell system.

  A fuel cell is a device that generally obtains electric energy using hydrogen and oxygen as fuel. Since this fuel cell is excellent in terms of the environment and can realize high energy efficiency, it has been widely developed as a future energy supply system.

  Examples of the fuel cell using a solid electrolyte include a solid polymer fuel cell and a solid oxide fuel cell. Among these, the polymer electrolyte fuel cell further includes a membrane electrode assembly (MEA) in which a solid polymer electrolyte membrane is sandwiched between a cathode catalyst layer and an anode catalyst layer (hereinafter referred to as a catalyst layer together). It has a stack structure in which a plurality of cells sandwiched between separators are stacked. In the polymer electrolyte fuel cell, fuel gas is supplied to the anode catalyst layer, and oxidant gas is supplied to the cathode catalyst layer. As a result, the fuel gas and the oxidant gas undergo an electrochemical reaction to generate water. The fuel cell generates electricity by taking out the current generated when the water is generated.

  In such a fuel cell, the form of the catalyst may change due to fuel gas and oxidant gas remaining after power generation is stopped. Thus, a technique is disclosed in which a stop time is predicted after the vehicle stops and a stop process is performed according to the predicted stop time (see, for example, Patent Document 1).

JP 2006-134741 A

  However, in the technique of Patent Document 1, if even a small amount of hydrogen remains, the cell voltage may increase again, resulting in a long power generation duration. As a result, the stop process takes time.

  The present invention provides a fuel cell system and a control method for the fuel cell system that can suppress a change in the form of the catalyst and can shorten the stop processing time when the power generation of the fuel cell is stopped. For the purpose.

  A fuel cell system according to the present invention includes a fuel cell that generates power using a fuel gas and an oxidant gas, a pressure adjustment unit that adjusts the pressure of the fuel gas in the fuel cell, and a power generation control unit that controls the power generation of the fuel cell. And the time acquisition means for estimating or detecting the power generation stop time when the fuel cell power generation is stopped, and the power generation stop time acquired by the time acquisition means by comparing the power generation stop time acquired by the time acquisition means with a predetermined time. Control for controlling the pressure adjusting means so that the pressure of the fuel gas in the fuel cell rises when the time is equal to or less than a predetermined time, and controlling the power generation control means so that the power generation of the fuel cell is stopped, and the power generation stop time If the pressure is longer than a predetermined time, the pressure control means is controlled so that the pressure of the fuel gas in the fuel cell decreases, and the power generation control Controlling the control, it is characterized in that and a control means for performing at least one of.

  According to the fuel cell system of the present invention, when the power generation stop time of the fuel cell is equal to or shorter than the predetermined time, the pressure of the fuel gas increases and the power generation of the fuel cell stops. Thereby, the shape change of a catalyst layer can be suppressed. In this case, since it is not necessary to generate power from the fuel cell, the stop processing time when the fuel cell stops generating power is shortened. Furthermore, since it is not necessary to consume fuel gas, wasteful consumption of hydrogen can be suppressed. Further, according to the fuel cell system of the present invention, when the power generation stop time is longer than the predetermined time, the pressure of the fuel gas in the fuel cell is reduced and the power generation of the fuel cell is continued. This shortens the consumption time of the remaining fuel gas in the cathode catalyst layer. Thereby, the shape change of a catalyst layer can be suppressed.

  In the above configuration, the control means adjusts the pressure so that the pressure of the fuel gas in the fuel cell rises to a pressure set according to the power generation stop time when the power generation stop time acquired by the time acquisition means is less than a predetermined time. The power generation stop control means may be controlled so as to stop the power generation of the fuel cell while controlling the means.

  In the above configuration, the apparatus further comprises pressure detecting means for detecting the fuel gas pressure in the fuel cell, and gas supply means for controlling the supply of the fuel gas and the oxidant gas to the fuel cell. Is longer than the predetermined time, the gas supply means is controlled so that the supply of fuel gas is stopped when the detected pressure of the pressure detection means falls below a predetermined value, and the power generation so that the power generation of the fuel cell is stopped. It may control the control means.

  In the above configuration, the apparatus further includes voltage detection means for detecting a cell voltage in the fuel cell, and the control means is configured to oxidize when the detection voltage of the voltage detection means becomes a predetermined value or less when the power generation stop time is longer than the predetermined time. You may control a gas supply means so that supply of gas may be stopped. According to this configuration, since the voltage of each cell is detected, it is possible to suppress the influence of the voltage variation between the cells. Therefore, the reverse potential can be suppressed in any cell. As a result, changes in the shape of the catalyst layer can be suppressed.

  The above configuration may further include an input unit capable of inputting a power generation stop time of the fuel cell, and the time acquisition unit may acquire the power generation stop time by detecting the power generation stop time input to the input unit. Good. The said structure WHEREIN: The position acquisition means which acquires the position of a fuel cell system may be further provided, and a time acquisition means may estimate an electric power generation stop time based on the acquisition result of a position acquisition means. The said structure WHEREIN: The time acquisition means which acquires time may be further provided, and a time acquisition means may estimate an electric power generation stop time based on the acquisition result of a time acquisition means.

  In the above configuration, the time acquisition unit may estimate the power generation stop time based on a past history of the power generation stop time of the fuel cell.

  The control method of the fuel cell system according to the present invention includes a step of estimating or detecting a power generation stop time when power generation of the fuel cell is stopped, and increasing the pressure of the fuel gas of the fuel cell when the power generation stop time is a predetermined time or less. At least one of a step of stopping power generation of the fuel cell and a step of reducing the pressure of the fuel gas in the fuel cell and continuing the power generation of the fuel cell when the power generation stop time is longer than a predetermined time. It is characterized by comprising.

  According to the control method of the fuel cell system according to the present invention, when the power generation stop time of the fuel cell is equal to or shorter than the predetermined time, the pressure of the fuel gas is increased and the power generation of the fuel cell is stopped. Thereby, the shape change of a catalyst layer can be suppressed. In this case, since it is not necessary to generate power from the fuel cell, the stop processing time when the fuel cell stops generating power is shortened. Furthermore, since it is not necessary to consume fuel gas, wasteful consumption of hydrogen can be suppressed. Further, according to the control method of the fuel cell system according to the present invention, when the power generation stop time is longer than the predetermined time, the pressure of the fuel gas in the fuel cell decreases and the power generation of the fuel cell continues. This shortens the consumption time of the remaining fuel gas in the cathode catalyst layer. Thereby, the shape change of a catalyst layer can be suppressed.

  The above control method includes a step of increasing the pressure of the fuel gas in the fuel cell to a pressure set according to the power generation stop time and stopping the power generation of the fuel cell when the power generation stop time is equal to or shorter than a predetermined time. There may be.

  In the above control method, when the power generation stop time is longer than a predetermined time, the method further includes the step of stopping the fuel gas supply and the power generation of the fuel cell when the fuel gas pressure in the fuel cell becomes a predetermined value or less. It may be.

  In the above control method, when the power generation stop time is longer than the predetermined time, the method may further include a step of stopping the supply of the oxidant gas when the cell voltage in the fuel cell becomes a predetermined value or less. According to this control method, since the voltage of each cell is detected, it is possible to suppress the influence of the voltage variation between the cells. Therefore, the reverse potential can be suppressed in any cell. As a result, changes in the shape of the catalyst layer can be suppressed.

  In the above control method, the step of estimating or detecting the power generation stop time may be a step of detecting the power generation stop time by detecting the input power generation stop time. In the above control method, the step of estimating or detecting the power generation stop time may be a step of estimating the power generation stop time based on the acquired position information. In the above control method, the step of estimating or detecting the power generation stop time may be a step of estimating the power generation stop time based on the acquired time information.

  In the above control method, the step of estimating or detecting the power generation stop time when the fuel cell stops generating power may be a step of estimating the power generation stop time based on a past history of the power generation stop time.

  According to the present invention, there is provided a fuel cell system and a control method for the fuel cell system that can suppress a change in the form of the catalyst and can shorten the stop processing time when the power generation of the fuel cell is stopped. Can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described.

  First, the fuel cell system 300 according to the first embodiment of the present invention will be described. FIG. 1 is a block diagram showing the configuration of the fuel cell system 300. As shown in FIG. 1, the fuel cell system 300 includes a fuel cell 20, a gas supply unit 30, a detection unit 60, a power generation control unit 70, a pressure adjustment unit 75, a time acquisition unit 80, an input unit 90, and a control unit 200. .

  The fuel cell 20 has a stack structure in which a plurality of cells 10 are stacked. End plates 25 are respectively disposed at both ends of the stacked body of the cells 10. Each end plate 25 is provided with a piping portion (not shown) for supplying or discharging the oxidant gas and the fuel gas to each cell 10.

  The gas supply means 30 is means for supplying fuel gas and oxidant gas to the fuel cell 20. The gas supply means 30 includes an oxidant gas supply means (not shown) and a fuel gas supply means (not shown). The oxidant gas supply means is means for supplying oxidant gas to the fuel cell 20. The fuel gas supply means is means for supplying fuel gas to the fuel cell 20. As the oxidant gas, for example, air containing oxygen is used. For example, hydrogen is used as the fuel gas. Hereinafter, fuel gas and oxidant gas are collectively referred to as reaction gas. The gas supply means 30 supplies the reaction gas to each cell 10 in accordance with instructions from the control means 200. Thereby, power generation is performed in each cell 10.

  The detection means 60 includes a pressure detection means 62 and a voltage detection means 65 and is connected to the fuel cell 20. The pressure detection means 62 is a means for detecting the fuel gas pressure in the fuel cell 20. The voltage detection means 65 is means for detecting the cell voltage of each cell 10. The pressure detection unit 62 and the voltage detection unit 65 transmit the detection result to the control unit 200.

  The power generation control means 70 is means for controlling the power generation of the fuel cell 20. The power generation control means 70 includes, for example, a switch connected to the plus terminal and the minus terminal of the fuel cell 20. When the power generation control means 70 is turned on, a closed circuit is formed. Thereby, power generation of the fuel cell 20 is started. In this case, power is consumed in a load (not shown). When the power generation control means 70 is turned off, an open circuit is formed. Thereby, the power generation of the fuel cell 20 is stopped. In response to an instruction from the control means 200, the power generation control means 70 starts or stops power generation of the fuel cell 20.

  The pressure adjusting means 75 is a means for adjusting the pressure of the fuel gas in the fuel cell 20. The pressure adjusting means 75 is constituted by, for example, a pressure adjusting valve. The pressure adjusting means 75 is connected to the fuel cell 20. The pressure adjusting unit 75 adjusts the pressure of the fuel gas in the fuel cell 20 in response to an instruction from the control unit 200.

  The time acquisition means 80 is means for detecting the power generation stop time when the fuel cell 20 stops generating power. Here, the time when power generation is stopped refers to the case where the output request to the fuel cell 20 is stopped. Further, the power generation stop time refers to the time from when the fuel cell 20 stops generating power until the fuel cell 20 starts generating power. The time acquisition unit 80 notifies the control unit 200 of the power generation stop time acquired from the input unit 90.

  The input means 90 is a means by which an operator of the fuel cell system 300 can input the power generation stop time of the fuel cell 20. As the input means 90, for example, an input terminal such as a keyboard or a touch panel can be used. The input unit 90 transmits the acquisition result to the time acquisition unit 80.

  The control means 200 includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory) and the like. The control unit 200 controls the fuel cell system 300 based on the results received from the detection unit 60 and the time acquisition unit 80.

  FIG. 2 shows a schematic cross-sectional view of the cell 10. As shown in FIG. 2, the cell 10 has a structure in which a separator 110a, a diffusion layer 108a, a cathode catalyst layer 104, an electrolyte membrane 102, an anode catalyst layer 106, a diffusion layer 108b, and a separator 110b are sequentially stacked. The electrolyte membrane 102 is made of a solid polymer electrolyte having proton conductivity, for example, a perfluorosulfonic acid polymer.

  The cathode catalyst layer 104 is a catalyst layer that promotes the reaction between protons and oxygen. The anode catalyst layer 106 is a catalyst layer that promotes protonation of hydrogen. The cathode catalyst layer 104 and the anode catalyst layer 106 are made of, for example, platinum-supported carbon. The diffusion layer 108a is a layer that transmits an oxidant gas containing oxygen. The diffusion layer 108b is a layer that transmits a fuel gas containing hydrogen. The diffusion layers 108a and 108b are made of, for example, carbon paper. The separator 110a is provided with an oxidant gas flow path 112a. The separator 110b is provided with a fuel gas flow path 112b.

  Fuel gas is supplied from the fuel gas supply means to the fuel gas flow path 112b. The fuel gas passes through the diffusion layer 108b and reaches the anode catalyst layer 106. Hydrogen contained in the fuel gas is dissociated into protons and electrons via the catalyst of the anode catalyst layer 106. The protons conduct through the electrolyte membrane 102 and reach the cathode catalyst layer 104.

  Oxidant gas is supplied to the oxidant gas flow path 112a from the oxidant gas supply means. The oxidant gas passes through the diffusion layer 108a and reaches the cathode catalyst layer 104. In the cathode catalyst layer 104, protons and oxygen react via the catalyst. Thereby, power generation is performed and water is generated. The water generated by the power generation is discharged to the outside mainly through the oxidant gas passage 112a and the fuel gas passage 112b.

  Here, in the process in which the power generation of the fuel cell 20 is stopped, the form of the catalyst of the cathode catalyst layer 104 may change. In this case, the power generation performance of the fuel cell 20 may be reduced. FIG. 3 illustrates changes in the catalyst form of the cathode catalyst layer 104 when the fuel cell 20 stops generating power. The vertical axis in FIG. 3 represents the rate of progress of the shape change per unit time of the catalyst in the cathode catalyst layer 104, and the horizontal axis in FIG. 3 represents time. Therefore, the area in the range surrounded by the curve drawn in FIG. 3 and the horizontal axis indicates the amount of change in the shape of the catalyst.

  A curve 120a in FIG. 3 shows a form change when the supply of both the fuel gas and the oxidant gas from the gas supply means 30 is stopped and the power generation control means 70 is turned off. In this case, since oxygen is insufficient in the cathode catalyst layer 104, the catalyst shape change does not proceed as shown in FIG. However, when a predetermined time (time 125a in FIG. 3) elapses, the catalyst shape changes due to the inflowing oxygen and the remaining fuel gas. In this case, the time until the catalyst shape change is started is relatively long, but the catalyst shape change amount is relatively large.

  The time until the catalyst shape change is started varies depending on the pressure of the fuel gas. As shown by the curves 120b and 120c in FIG. 3, the time until the catalyst shape change starts increases as the pressure of the fuel gas increases. However, as the pressure of the fuel gas increases, the amount of change in shape increases. Note that the pressure of the fuel gas is limited by the sealing material of the fuel cell 20 or the like. A curve 120c in FIG. 3 indicates the maximum pressure that the fuel cell 20 can tolerate.

  On the other hand, as an example, a curve 120d shows a form change when the pressure of the fuel gas is reduced, the supply of the oxidant gas is continued, and the power generation control means 70 is turned on. In this case, the fuel gas is consumed as the fuel cell 20 generates power. Thereby, the shape change of the catalyst proceeds. However, in this case, the time until the fuel gas is consumed is shortened. Accordingly, the amount of change in the shape of the catalyst is smaller than in the case of the curves 120a, 120b, and 120c.

  In this embodiment, if the acquisition result of the time acquisition unit 80 is equal to or less than a predetermined time, the control unit 200 causes the pressure adjustment unit 75 to increase the fuel gas pressure to a pressure set according to the power generation stop time. The power generation control means 70 is controlled so that the power generation of the fuel cell 20 is stopped. Here, the pressure set according to the power generation stop time refers to the fuel gas pressure that is equal to or less than the time until the power generation stop time starts to change in form.

  For example, as shown in FIG. 3, if the predetermined time is 125b, the control means 200 causes the pressure adjusting means 75 to increase the pressure of the fuel gas from the pressure corresponding to the curve 120b to the pressure range corresponding to the curve 120c. And the power generation of the fuel cell 20 is stopped. Thereby, the form change shown in the curves 120a, 120b, 120c, and 120d can be avoided. Further, in this case, since it is not necessary to generate power for the fuel cell 20, the stop processing time when the fuel cell 20 stops generating power is shortened. Furthermore, since it is not necessary to consume fuel gas, wasteful consumption of hydrogen can be suppressed.

  If the acquisition result of the time acquisition unit 80 is equal to or less than a predetermined time, the control unit 200 may control the pressure adjustment unit 75 so that the pressure of the fuel gas increases to a pressure corresponding to the curve 120c. In this case, the time until the catalyst shape change starts is maximized. However, if the residual hydrogen pressure at the start-up of the fuel cell 20 is high, the shape change of the sealing material may occur, so that the end time of the power generation stop time is equal to the time until the start of the shape change. It is preferable that the pressure of the fuel gas is adjusted.

  On the other hand, if the acquisition result of the time acquisition means 80 is greater than the time 125c, the control means 200 controls the pressure adjustment means 75 so that the pressure of the fuel gas decreases, and the power generation of the fuel cell 20 is continued. The power generation control means 70 is controlled. Thereby, the form change shown in the curves 120a, 120b, 120c can be avoided.

  Next, details of the operation of the fuel cell system 300 will be described. FIG. 4 shows an example of a flowchart when the fuel cell system 300 stops power generation. For example, when the output request to the fuel cell 20 is stopped, the time acquisition unit 80 detects the power generation stop time input to the input unit 90 and transmits it to the control unit 200 (step S1).

  The control means 200 determines whether or not the power generation stop time is equal to or less than a predetermined value (step S2). In addition, what is necessary is just to use the time which the form change of a catalyst layer is accept | permitted about the predetermined time of electric power generation stop time. For example, the time 125c in FIG. 3 corresponds to a predetermined time. The time 125c depends on design items such as a material used for the fuel cell 20. Therefore, the time 125c may be obtained in advance by an experiment or the like and stored in the ROM of the control means 200.

  When it is determined in step S2 that the power generation stop time is equal to or shorter than the predetermined time, the control means 200 controls the pressure so that the pressure of the fuel gas in the fuel cell 20 rises to a pressure set according to the power generation stop time. The power generation control means 70 is controlled so as to stop the power generation of the fuel cell 20 while controlling the adjustment means 75 (step S3). Thereby, the shape change of the curves 120a, 120b, 120c, and 120d in FIG. 3 can be avoided. Thereafter, the control unit 200 ends the execution of the flowchart.

  If it is not determined in step S2 that the stop time is equal to or shorter than the predetermined time, the control unit 200 controls the pressure adjusting unit 75 so that the fuel gas pressure in the fuel cell 20 decreases, and the power generation of the fuel cell 20 Is controlled so as to continue (step S4). In this case, in the cathode catalyst layer 104, the remaining fuel gas reacts with the oxidant gas and is consumed. Thereby, the shape change of the curves 120a, 120b, and 120c in FIG. 3 can be avoided. In addition, the electric power obtained by electric power generation can be used as energy at the time of cooling cooling water, for example.

  Subsequently, the control means 200 determines whether or not the detected pressure of the fuel cell 20 detected by the pressure detection means 62 is equal to or lower than a predetermined pressure (step S5). Since the predetermined pressure varies depending on the material used for the fuel cell 20, the predetermined pressure may be obtained in advance by experiments and stored in the ROM of the control means 200. In this embodiment, for example, 80 kPa can be used as the predetermined pressure. When it is determined in step S5 that the fuel gas pressure is equal to or lower than the predetermined pressure, the control unit 200 controls the gas supply unit 30 so that the supply of the fuel gas is stopped, and the power generation of the fuel cell 20 is stopped. In step S6, the power generation control means 70 is controlled.

  Next, the control means 200 determines whether or not the voltage of each cell 10 detected by the voltage detection means 65 is equal to or lower than a predetermined voltage (step S7). The predetermined voltage may be obtained by experiments in advance and stored in the ROM of the control means 200. When it is determined that the voltage of each cell 10 is equal to or lower than the predetermined voltage, the control unit 200 controls the gas supply unit 30 so that the supply of the oxidant gas is stopped (step S8). Thereafter, the control unit 200 ends the execution of the flowchart.

  If it is not determined in step S5 that the fuel gas pressure is equal to or lower than the predetermined pressure, the control unit 200 executes step S4. On the other hand, if it is not determined in step S7 that the voltage of each cell 10 is equal to or lower than the predetermined voltage, the control unit 200 executes step S6.

  As described above, the control according to the flowchart described above can suppress the change in the catalyst form when the power generation of the fuel cell 20 is stopped. In addition, it is possible to shorten the stop processing time when the fuel cell 20 stops generating power.

  Moreover, since the voltage of each cell 10 is detected, the influence of the voltage variation between the cells 10 can be suppressed. Therefore, the reverse potential can be suppressed in any cell 10. As a result, a change in the shape of the catalyst can be suppressed. Note that step S7 may be executed based on the voltage of any of the cells 10. Even in this case, each cell voltage of the fuel cell 20 can be estimated. Step S7 may be omitted. This is because the cell voltage depends on the pressure of the fuel gas.

  In this embodiment, the control is switched using the time 125c as a threshold value, but the present invention is not limited to this. For example, if the next power generation is started immediately after the form change shown by the curve 120c starts, the form change amount may be smaller than the form change amount shown by the curve 120d. Therefore, the time when the shape change amount after the start of the curve 120c is the same as the shape change amount of the entire curve 120d may be used as a threshold value instead of the time 125c. In the present embodiment, the pressure adjusting means 75 is used to reduce the pressure of the fuel gas, but the present invention is not limited to this. For example, if the fuel cell 20 continues to generate power in a state where the supply of fuel gas is stopped, the pressure of the fuel gas decreases as the fuel gas is consumed. Therefore, if the gas supply means 30 is controlled so that the supply of the fuel gas is stopped and the power generation control means 70 is controlled so that the power generation of the fuel cell 20 is continued, the pressure of the fuel gas decreases.

  In the present embodiment, the control unit 200 executes both steps S3 and S4 to S8, but is not limited thereto. For example, the control means 200 may execute only one of step S3 and steps S4 to S8. That is, the control means 200 may execute only step S1, step S2, and step S3, or may execute only step S1, step S2, and step S4 to step S8.

  Subsequently, a fuel cell system 300a according to a second embodiment of the present invention will be described. FIG. 5 is a block diagram showing the configuration of the fuel cell system 300a. A fuel cell system 300a shown in FIG. 5 includes position acquisition means 92 instead of the input means 90 of the fuel cell system 300 shown in FIG. The other configuration is the same as that of the fuel cell system 300 shown in FIG. The position acquisition unit 92 is a unit that acquires the position of the fuel cell system 300a. For example, a navigation system or the like can be used.

  The position acquisition unit 92 transmits the acquisition result to the time acquisition unit 80. The time acquisition unit 80 estimates the power generation stop time based on the acquisition result of the position acquisition unit 92. Hereinafter, a specific example of the power generation stop time estimation by the time acquisition unit 80 will be described by taking an automobile equipped with the fuel cell system 300a as an example.

  For example, suppose you work at a company by car and stop the car at the company parking lot. At this time, the time acquisition unit 80 receives the current vehicle position information from the position acquisition unit 92. Then, the time acquisition means 80 estimates the power generation stop time of the fuel cell 20 with reference to a map or the like representing the relationship between the position information recorded in advance in the ROM and the parking time. This estimation procedure can be applied to places other than the company.

  The time acquisition unit 80 may estimate the power generation stop time based on the acquisition result of the position acquisition unit 92 and the past history of the parking time. For example, when the time for stopping the car in the company parking lot differs according to the day of the week, the date, etc., the time acquisition means 80 may estimate the power generation stop time with reference to the history. In addition, the time acquisition unit 80 may estimate that the power generation stop time is long when parking at the first place. In this case, at least changes in the shape of the curves 120a, 120b, and 120c in FIG. 3 can be avoided. In addition, the parking time in this case may be stored in the ROM, and the history may be used when parking at the place next time.

  Next, the operation of the fuel cell system 300a will be described in detail. FIG. 6 shows an example of a flowchart when power generation is stopped in the fuel cell system 300a. The flowchart shown in FIG. 6 includes step S1a instead of step S1 in the flowchart shown in FIG. Other configurations are the same as those in the flowchart shown in FIG. The time acquisition means 80 detects the position information acquired by the position acquisition means 92, estimates the power generation stop time based on the position information, and transmits it to the control means 200 (step S1a). In this case, the time acquisition unit 80 may estimate the power generation stop time based on the past history of the fuel cell 20.

  Also in the fuel cell system 300a according to the present embodiment, it is possible to suppress changes in the form of the catalyst when the power generation of the fuel cell 20 is stopped by the control according to the flowchart shown in FIG. In addition, it is possible to shorten the stop processing time when the fuel cell 20 stops generating power.

  In the present embodiment, the control unit 200 executes both steps S3 and S4 to S8, but is not limited thereto. For example, the control means 200 may execute only one of step S3 and steps S4 to S8. That is, the control unit 200 may execute only step S1a, step S2, and step S3, or may execute only step S1a, step S2, and step S4 to step S8.

  Subsequently, a fuel cell system 300b according to a third embodiment of the present invention will be described. FIG. 7 is a block diagram showing the configuration of the fuel cell system 300b. A fuel cell system 300b shown in FIG. 7 includes time acquisition means 95 instead of the input means 90 of the fuel cell system 300 shown in FIG. The other configuration is the same as that of the fuel cell system 300 shown in FIG. The time acquisition unit 95 is a unit that acquires the time of the fuel cell system 300b, and for example, a built-in clock, a radio clock, or the like can be used.

  The time acquisition unit 95 notifies the time acquisition unit 80 of the acquisition result. The time acquisition unit 80 estimates the power generation stop time based on the acquisition result of the time acquisition unit 95. Hereinafter, a specific example of the power generation stop time estimation by the time acquisition unit 80 will be described by taking an automobile equipped with the fuel cell system 300b as an example.

  For example, suppose that you return from a company by car and stop the car at your parking lot. At this time, the time acquisition unit 80 receives time information of the current car from the time acquisition unit 95. Then, the time acquisition means 80 estimates the power generation stop time of the fuel cell 20 with reference to a map or the like representing the relationship between the time information recorded in advance in the ROM and the parking time. This estimation procedure can be applied to places other than home.

  The time acquisition unit 80 may estimate the power generation stop time based on the acquisition result of the time acquisition unit 95 and the past history of the parking time. For example, when the time for stopping the car in the parking lot at home differs according to the day of the week, date, etc., the time acquisition means 80 may estimate the power generation stop time with reference to the history. The time acquisition means 80 may estimate that the power generation stop time is long when parking at a time not stored in the map or the like. In this case, at least changes in the shape of the curves 120a, 120b, and 120c in FIG. 3 can be avoided. In addition, the parking time in this case may be stored in the ROM, and the history may be used when parking at that time next time.

  Next, the operation of the fuel cell system 300b will be described in detail. FIG. 8 shows an example of a flowchart when power generation is stopped in the fuel cell system 300b. The flowchart shown in FIG. 8 includes step S1b instead of step S1 of the flowchart shown in FIG. Other configurations are the same as those in the flowchart shown in FIG. The time acquisition means 80 detects the time information acquired by the time acquisition means 95, estimates the power generation stop time based on the time information, and notifies the control means 200 (step S1b). In this case, the time acquisition unit 80 may estimate the power generation stop time based on the past history of the fuel cell 20.

  Also in the fuel cell system 300b according to the present embodiment, it is possible to suppress the change in the catalyst form when the power generation of the fuel cell 20 is stopped by the control according to the flowchart shown in FIG. In addition, it is possible to shorten the stop processing time when the fuel cell 20 stops generating power.

  The fuel cell system 300b may include the position acquisition unit 92 shown in FIG. In this case, the control means 200 can estimate the power generation stop time more accurately based on the position information and the time information. For example, even when parking at a specific place, the parking time may differ depending on the time.

  In the present embodiment, the control unit 200 executes both steps S3 and S4 to S8, but is not limited thereto. For example, the control means 200 may execute only one of step S3 and steps S4 to S8. That is, the control means 200 may execute only step S1b, step S2, and step S3, or may execute only step S1b, step S2, and step S4 to step S8.

1 is a schematic diagram of a fuel cell system according to a first embodiment of the present invention. It is a schematic diagram of the cell which concerns on 1st Example. It is a schematic diagram which shows the relationship between the morphological change rate of the catalyst of the cathode catalyst layer concerning 1st Example, and stop time. It is an example of the flowchart at the time of the electric power generation stop of the fuel cell system which concerns on 1st Example. It is a schematic diagram of the fuel cell system which concerns on 2nd Example of this invention. It is an example of the flowchart at the time of the electric power generation stop of the fuel cell system which concerns on 2nd Example. It is a schematic diagram of the fuel cell system which concerns on 3rd Example of this invention. It is an example of the flowchart at the time of the electric power generation stop of the fuel cell system which concerns on 3rd Example.

Explanation of symbols

10 cell 20 fuel cell 30 gas supply means 62 pressure detection means 65 voltage detection means 70 power generation control means 75 pressure adjustment means 80 time acquisition means 90 input means 92 position acquisition means 95 time acquisition means 200 control means 300 fuel cell system

Claims (16)

A fuel cell that generates power using fuel gas and oxidant gas;
Pressure adjusting means for adjusting the pressure of the fuel gas of the fuel cell;
Power generation control means for controlling power generation of the fuel cell;
Time acquisition means for estimating or detecting a power generation stop time when power generation of the fuel cell is stopped;
The power generation stop time acquired by the time acquisition means is compared with a predetermined time, and when the power generation stop time acquired by the time acquisition means is less than the predetermined time, the fuel gas in the fuel cell Controlling the pressure adjusting means to increase the pressure and controlling the power generation control means to stop the power generation of the fuel cell, and when the power generation stop time is longer than the predetermined time, Control means for performing at least one of control for controlling the pressure adjusting means so that the pressure of the fuel gas in the fuel cell is reduced and controlling the power generation control means so that power generation of the fuel cell is continued; A fuel cell system comprising:   The control means is configured to increase the pressure of the fuel gas in the fuel cell to a pressure set according to the power generation stop time when the power generation stop time acquired by the time acquisition means is equal to or shorter than the predetermined time. 2. The fuel cell system according to claim 1, wherein the power generation stop control means is controlled so as to control the pressure adjusting means and stop the power generation of the fuel cell. Pressure detecting means for detecting the fuel gas pressure in the fuel cell;
Gas supply means for controlling supply of the fuel gas and the oxidant gas to the fuel cell; and
The control means controls the gas supply means so that the supply of the fuel gas is stopped when the detected pressure of the pressure detection means becomes a predetermined value or less when the power generation stop time is longer than the predetermined time. The fuel cell system according to claim 1, wherein the power generation control means is controlled so that power generation of the fuel cell is stopped. Voltage detecting means for detecting a cell voltage in the fuel cell;
When the power generation stop time is longer than the predetermined time, the control means controls the gas supply means so that the supply of the oxidant gas is stopped when the detection voltage of the voltage detection means falls below a predetermined value. The fuel cell system according to claim 3, wherein: An input means capable of inputting the power generation stop time of the fuel cell;
The fuel cell system according to claim 1, wherein the time acquisition unit acquires the power generation stop time by detecting the power generation stop time input to the input unit. It further comprises position acquisition means for acquiring the position of the fuel cell system,
The fuel cell system according to claim 1, wherein the time acquisition unit estimates the power generation stop time based on an acquisition result of the position acquisition unit. It further comprises time acquisition means for acquiring time,
The fuel cell system according to claim 1, wherein the time acquisition unit estimates the power generation stop time based on an acquisition result of the time acquisition unit.   The fuel cell system according to claim 6 or 7, wherein the time acquisition means estimates the power generation stop time based on a past history of the power generation stop time of the fuel cell. Estimating or detecting a power generation stop time when the fuel cell power generation is stopped;
Increasing the pressure of the fuel gas in the fuel cell when the power generation stop time is less than or equal to a predetermined time and stopping the power generation of the fuel cell; and when the power generation stop time is longer than the predetermined time, the fuel cell A method for controlling the fuel cell system, comprising: reducing the pressure of the fuel gas in the fuel cell and continuing the power generation of the fuel cell.   A step of increasing the pressure of the fuel gas in the fuel cell to a pressure set according to the power generation stop time and stopping the power generation of the fuel cell when the power generation stop time is a predetermined time or less. A control method for a fuel cell system according to claim 9.   When the power generation stop time is longer than the predetermined time, the fuel cell further includes a step of stopping supply of the fuel gas and stopping power generation of the fuel cell when a fuel gas pressure in the fuel cell becomes a predetermined value or less. The method of controlling a fuel cell system according to claim 9, wherein:   The fuel according to claim 11, further comprising a step of stopping the supply of the oxidant gas when the power generation stop time is longer than the predetermined time when a cell voltage in the fuel cell becomes a predetermined value or less. Battery system control method.   The step of estimating or detecting the power generation stop time is a step of detecting the power generation stop time by detecting the input power generation stop time. Control method of fuel cell system.   13. The fuel cell system control according to claim 9, wherein the step of estimating or detecting the power generation stop time is a step of estimating the power generation stop time based on the acquired position information. Method.   The control of the fuel cell system according to any one of claims 9 to 12, wherein the step of estimating or detecting the power generation stop time is a step of estimating the power generation stop time based on the acquired time information. Method.   16. The method of controlling a fuel cell system according to claim 14, wherein the step of estimating or detecting the power generation stop time is a step of estimating the power generation stop time based on a past history of the power generation stop time. .

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