JP2006253005A - Fuel cell system and starting method of fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system capable of establishing low the withstand voltage of a load side and capable of improving durability of the fuel cell. <P>SOLUTION: The fuel cell system comprises a fuel cell main body 1 which has a fuel electrode 1b and an oxidant electrode 1a arranged interposing an electrolyte membrane and generates power by electrochemical reaction of a fuel gas and an oxidant gas, and a hydrogen system for supplying the fuel gas to the fuel electrode and an air system for supplying the oxidant gas to the oxidant electrode. At the time of starting, the target value of the fuel gas pressure at the fuel electrode is established at a higher pressure than at a normal time and the pressure of the fuel gas is adjusted, and further, by an oxidant gas pressure setting means in the controller 43, the target value of the oxidant gas pressure at the oxidant electrode is established at the lower limit pressure value or more of the oxidant electrode as determined by the inter-film permissible differential pressure of the electrolyte membrane and at the upper limit pressure value or less of the oxidant electrode at which the output voltage of the fuel cell main body 1 becomes a prescribed value or less, and the oxidant pressure is adjusted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel cell system and a fuel cell system start-up method, and in particular, the output voltage of the fuel cell at the time of start-up can be kept low, the withstand voltage on the load side can be set low and the oxidant gas pressure on the oxidant electrode side The present invention relates to a fuel cell system that can increase the durability of a fuel cell (electrolyte membrane, etc.) by setting the pressure to a value that keeps the pressure difference between membranes within an allowable value, and a method for starting the fuel cell system.

  The fuel cell system supplies hydrogen as a fuel gas to the fuel electrode of the fuel cell, supplies air as the oxidant gas to the oxidant electrode of the fuel cell, and causes the hydrogen and oxygen in the air to react electrochemically. To obtain generated power. Such a fuel cell system is highly expected to be put into practical use, for example, as a power source for automobiles, and research and development for practical use are being actively carried out.

  As a fuel cell used in a fuel cell system. For example, a solid polymer type fuel cell is known as being suitable for mounting in an automobile. A solid polymer type fuel cell is provided with a solid polymer membrane as an electrolyte membrane between a fuel electrode and an oxidant electrode. In this solid polymer type fuel cell, the solid polymer membrane functions as an ion conductor, a reaction occurs in which hydrogen is separated into hydrogen ions and electrons at the fuel electrode, and oxygen and hydrogen in the air at the oxidant electrode. A reaction for generating water from ions and electrons is performed.

In such a fuel cell system, when the fuel gas is supplied at the same gas pressure as that of the fuel gas supplied during normal operation of the fuel cell at startup, the fuel gas is instantaneously generated in the fuel chamber. There is a problem that uneven distribution of the gas and the replacement gas occurs, and an electrochemical reaction occurs due to the uneven distribution and the electrode deteriorates. In order to cope with such a problem, in the fuel cell system disclosed in Japanese Patent Application Laid-Open No. 2004-139984, the replacement gas in the fuel electrode is supplied by supplying the fuel gas at the time of starting at a pressure higher than the pressure at the time of normal operation. The uneven distribution of gas between the fuel gas (for example, being replaced by air during stoppage) and the fuel gas is suppressed, and deterioration of the electrode, the catalyst, and the like is suppressed.
JP 2004-139984 A

  However, as in the technique disclosed in Patent Document 1 described above, when high-pressure activation of the fuel gas is performed, a pressure difference between the fuel electrode and the oxidant electrode is attached, and the inter-membrane difference determined by the strength of the electrolyte membrane. There was a problem that the pressure could not be protected.

  Therefore, it is conceivable to suppress the transmembrane pressure difference by increasing the supply pressure of the oxidant gas (air). However, even with this countermeasure, there was a problem of sound and vibration of the air supply means such as the compressor and blower.

  Also, the higher the pressure of the fuel gas or oxidant gas, the higher the fuel cell voltage. Therefore, various components that are electrically connected to the fuel cell when starting up have a fuel cell voltage higher than that during normal operation. There was a problem of exceeding the allowable voltage of. Further, when the allowable voltage is increased in order to cope with the high fuel cell voltage at the start-up, there is a problem that the size of the electric component becomes large or becomes expensive.

  The present invention has been made in view of the above-described conventional circumstances, and can suppress the output voltage of the fuel cell at the time of start-up and set the withstand voltage on the load side to be low, and the oxidant gas pressure on the oxidant electrode side. It is an object of the present invention to provide a fuel cell system that can increase the durability of a fuel cell (electrolyte membrane, etc.) by setting the pressure to be within the allowable value of the transmembrane pressure difference, and a method for starting the fuel cell system.

  In order to solve the above-described object, the present invention includes a fuel electrode and an oxidant electrode arranged with an electrolyte membrane interposed therebetween, and an electrochemical reaction between the fuel gas and the oxidant gas supplied to the fuel electrode and the oxidant electrode, respectively. A fuel cell for generating power by means of fuel, a fuel gas supply means for supplying fuel gas to the fuel electrode, an oxidant gas supply means for supplying oxidant gas to the oxidant electrode, and a fuel gas at the fuel electrode at startup Fuel gas pressure setting means for setting the target value of pressure to a pressure higher than normal, and the target value of the oxidant gas pressure at the oxidant electrode, the oxidant electrode lower limit determined from the allowable pressure difference between the electrolyte membranes And an oxidant gas pressure setting means for setting the fuel cell so that the output voltage of the fuel cell is not more than a predetermined value and not more than an oxidant electrode upper limit pressure value.

  In the fuel cell system and the fuel cell system start-up method according to the present invention, the fuel electrode side to be replaced with the fuel gas has a high fuel gas pressure, and the oxidant electrode side that does not need to have the oxidant gas pressure low. The output voltage of the fuel cell at the time of startup can be kept low, and the withstand voltage of the load device can be set low. Furthermore, since the oxidant gas pressure on the oxidant electrode side is set to a pressure that keeps the pressure difference within the allowable value of the transmembrane pressure, the durability of the fuel cell (electrolyte membrane, etc.) can be improved.

  Embodiments of a fuel cell system and a fuel cell system activation method according to the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a configuration diagram of a fuel cell system according to Embodiment 1 of the present invention. The fuel cell system of the present embodiment is used as a driving power source of a fuel cell vehicle, for example.

  As shown in FIG. 1, the schematic configuration of the fuel cell system of this embodiment includes a fuel cell main body 1 that generates power by supplying fuel gas (hydrogen) and oxidant gas (air). In addition, the conceptual diagram of the unit cell of the fuel cell main body 1 is shown in FIG.

  The air system (oxidant gas supply means) includes an air compressor 11, an air supply path 12, an air system humidifier 13, an air exhaust path 14, an air pressure control valve 15, and an air pressure gauge 16, and a hydrogen system (fuel gas). As a supply means), a high-pressure hydrogen tank 21, a hydrogen supply path 22, a hydrogen pressure regulating valve 23, a hydrogen circulation device 24, a hydrogen humidifier 25, a hydrogen circulation path 26, a hydrogen exhaust path 27, a hydrogen discharge valve 28, and a hydrogen pressure gauge 29 As a cooling water system, a cooling water pump 31, a cooling water circulation path 32, a heat exchanger 33, and a cooling water thermometer 34 are provided. Further, the load system includes a load device 40, a voltmeter 41, and an ammeter 42, and further, as a control system, based on detection signals from various instruments such as hydrogen system, air system, cooling water system, load system, and other various instruments. This is a configuration including a controller 43 that controls each component of a hydrogen system, an air system, a cooling water system, and a load system.

  Next, the fuel cell main body 1 and each system will be described in detail. First, in the fuel cell main body 1, an oxidant electrode 1 a supplied with air as an oxidant gas and a fuel electrode 1 b supplied with hydrogen as a fuel gas are overlapped with an electrolyte interposed therebetween to constitute a power generation cell. In addition, the fuel cell unit 100 is formed by stacking a plurality of fuel cell single cells 100 configured as shown in FIG. 2, and is supplied from a fuel gas (hydrogen) supplied from a hydrogen system outside the fuel cell main body 1 and an air system. The oxidant gas (air) is supplied to the fuel gas channel 109 and the oxidant gas channel 110, respectively, and generates electric power by an electrochemical reaction.

  In FIG. 2, a fuel cell single cell 100 includes, for example, a membrane electrode assembly (MEA) in which a fuel electrode catalyst layer 103 and an oxidant electrode catalyst layer 104 are formed on both surfaces of an electrolyte membrane 102 using a solid polymer electrolyte membrane, respectively. ) 101, a fuel gas diffusion layer 105 and an oxidant gas diffusion layer 106 disposed on both surfaces of the MEA 101, and separators 107 and 108, and a fuel gas between the separator 107 and the fuel gas diffusion layer 105. The flow path 109 has a structure in which an oxidant gas flow path 110 is provided between the separator 108 and the oxidant gas diffusion layer 106.

  Next, in the air system, the air compressed by the air compressor 11 is sent to the air system humidifier 13 via the air supply path 12, humidified, and then sent to the oxidant electrode 1 a of the fuel cell body 1. After oxygen is consumed by the electrochemical reaction in the fuel cell main body 1, the pressure passes through the air exhaust path 14, the pressure is adjusted by the air pressure regulating valve 15, and the air is exhausted outside the system. The pressure of the air supplied to the oxidant electrode 1a is detected by an air pressure gauge 16 provided at the inlet of the oxidant electrode 1a, and the controller 43 controls the air pressure adjustment valve so that this pressure becomes a desired pressure. 15 is controlled. The air humidifier 13 may be a device using a water vapor exchange membrane that uses moisture in the exhaust or a device that supplies pure water from the outside.

  Next, in the hydrogen system, the hydrogen supplied from the high-pressure hydrogen tank 21 passes through the hydrogen supply path 22, is regulated to a desired pressure by the hydrogen pressure regulating valve 23, and joins the exhaust hydrogen circulated by the hydrogen circulation device 24. Then, it is humidified by the hydrogen humidifier 25 and sent to the fuel electrode 1b of the fuel cell body 1. The pressure of hydrogen supplied to the fuel electrode 1b is detected by a hydrogen pressure gauge 29 provided at the inlet of the fuel electrode 1b, and the controller 43 controls the hydrogen pressure regulating valve 23 so that this pressure becomes a desired pressure. Be controlled. Further, after hydrogen is consumed by the electrochemical reaction in the fuel cell main body 1, the excessively supplied hydrogen passes through the hydrogen circulation path 26 and is again used for power generation by the hydrogen circulation device 24.

  In the hydrogen system, nitrogen that crosses over from the oxidizer electrode 1a to the fuel electrode 1b during operation and impurities contained in the high-pressure hydrogen tank 21 accumulate, so that these are discharged to the outside of the system. The hydrogen discharge path 27 and the hydrogen discharge valve 28 are provided.

  In the fuel cell system of this embodiment, a cooling water system is provided in order to remove heat generated by power generation of the fuel cell main body 1 and keep the fuel cell main body 1 at an appropriate temperature. In this cooling water system, the cooling water pumped by the cooling water pump 31 passes through the fuel cell main body 1, absorbs heat, passes through the cooling water circulation path 32, and exhausts heat to the outside of the system by the heat exchanger 33. Then, it is again pumped to the fuel cell main body 1 by the cooling water pump 31. Further, the controller 43 adjusts the temperature to an appropriate temperature for power generation of the fuel cell body 1 while monitoring the cooling water temperature with the cooling water thermometer 34.

  Next, in the load system, the load device 40 that consumes the generated power of the fuel cell main body 1 supplies power to the vehicle drive motor when the fuel cell system of this embodiment is applied to, for example, a fuel cell vehicle. It is an inverter device. The generated voltage of the fuel cell main body 1 is detected by a voltmeter 41, and the current supplied from the fuel cell main body 1 to the load device 40 is detected by an ammeter 42.

  Further, in the control system, the controller 43 is configured as a microcomputer having, for example, a CPU, a ROM, a RAM, a peripheral interface, and the like, and controls the entire fuel cell system including the fuel cell main body 1. In addition, the controller 43 sets the fuel cell body 1 to the optimum pressure / pressure which is set in advance based on detection signals from the air pressure gauge 16, the hydrogen pressure gauge 29, the cooling water thermometer 34, the voltmeter 41 and the ammeter 42. Control signals are output to the air compressor 11, the air pressure regulating valve 15, the hydrogen pressure regulating valve 23, the hydrogen discharge valve 28, the cooling water pump 31, and the load device 40 in order to obtain temperature, flow rate, and load.

  Further, the controller 43 has, as functional components, a fuel gas pressure setting means for setting a target value of the fuel gas pressure at the fuel electrode 1b to a pressure higher than normal at the time of startup, and an oxidant in the oxidant electrode 1a. The target value of the gas pressure is equal to or higher than the oxidant minimum lower limit pressure value determined from the inter-membrane allowable pressure difference of the electrolyte membrane 102, and is equal to or lower than the oxidant electrode upper limit pressure value at which the output voltage of the fuel cell body 1 is equal to or lower than a predetermined value. The oxidant gas pressure setting means is set so as to be, but these means are realized as a functional group of programs executed on the CPU.

  In this embodiment, instead of the temperature detecting means for detecting the internal temperature of the fuel cell main body 1, the temperature in the fuel cell main body 1 is estimated from the temperature detection result using the cooling water thermometer 34 of the cooling water system. In the oxidant gas pressure setting means, the oxidant electrode upper limit pressure value and the oxidant electrode lower limit pressure value are changed according to the temperature detection result.

  Next, a starting method and a pressure setting method for the oxidizer electrode 1a and the fuel electrode 1b at the time of starting in the fuel cell system of the present embodiment having the above-described configuration will be described with reference to FIGS. Here, FIG. 3 is an explanatory view for explaining the temporal transition of the fuel electrode gas pressure and the oxidant electrode gas pressure set by the starting method of the fuel cell system of this embodiment, and FIG. 4 is the fuel cell main body. It is explanatory drawing explaining the time transition of 1 output voltage.

  First, the pressure setting on the fuel electrode 1b side is performed as follows. In the hydrogen system, hydrogen in the high-pressure hydrogen tank 21 is suppressed in order to suppress the uneven distribution of gas between the replacement gas in the fuel electrode 1b (for example, being replaced with air during stoppage) and the supplied hydrogen. After being regulated by the hydrogen pressure regulating valve 23, it is supplied to the fuel electrode 1b. That is, at the time of start-up, the fuel gas pressure setting means of the controller 43 sets the target value of the fuel gas pressure at the fuel electrode 1b to a pressure higher than normal, and the hydrogen pressure regulating valve 23 is adjusted so as to be the target value. . At this time, the fuel gas (hydrogen gas) pressure in the fuel electrode 1b is measured by the hydrogen pressure gauge 29. The fuel gas pressure suppresses deterioration of the electrode, the catalyst, etc. (that is, the replacement gas in the fuel electrode 1b and From the point of view of mitigating the uneven distribution of gas between the fuel gas and the fuel gas, the higher the value (the higher the hydrogen flow rate), the better the pressure resistance of the fuel cell itself, and the higher Needless to say.

  On the other hand, the pressure setting on the oxidant electrode 1a side is performed as follows. In the air system, the air compressed by the air compressor 11 is supplied to the oxidant electrode 1a. The target value of the oxidant gas pressure in the oxidant electrode 1a is determined by the oxidant gas pressure setting means of the controller 43 based on the allowable pressure difference between the membranes of the electrolyte membrane 102 (the membrane indicated by the broken line in FIG. 3). The lower limit of the pressure difference between the pressures of the fuel cell 1 and the output voltage of the fuel cell body 1 is set to be equal to or lower than the oxidizer electrode upper limit pressure value (upper limit indicated by the broken line in FIG. 3). The air pressure regulating valve 15 is adjusted so that the pressure measured by the pressure gauge 34 falls within the predetermined pressure range. That is, the actual pressure of the oxidant gas pressure is within a predetermined pressure range, that is, the differential pressure between the oxidant electrode 1a and the fuel electrode 1b exceeds the differential pressure resistance of the electrolyte membrane 102, and the electrolyte membrane 102 may be damaged. The oxidizer electrode lower limit pressure value is not less than the oxidizer electrode lower limit pressure value, and the output voltage of the fuel cell body 1 does not exceed the withstand voltage of the load device 40 (upper limit voltage indicated by the broken line in FIG. 4). So that it is controlled.

  The oxidant minimum lower limit pressure value is determined from the pressure-resistant strength of the electrolyte membrane 102. That is, it is a mechanical property of the electrolyte membrane 102 and can be experimentally obtained in advance. Furthermore, it is known that the strength of the electrolyte membrane 102 made of a polymer decreases as the temperature increases. A relationship between “the differential pressure resistance strength of the electrolyte membrane 102” and “the temperature of the electrolyte membrane 102” is obtained in advance, the cooling water is allowed to flow at the time of startup, and the temperature detected by the cooling water thermometer 34 is set in the fuel cell main body 1. The oxidant minimum lower limit pressure is changed accordingly. For example, as shown in FIG. 3, the higher the temperature in the fuel cell body 1, the higher the oxidant minimum lower limit pressure value is set.

  The oxidant electrode upper limit pressure value is determined from the withstand voltage of the load device 40 to which the output of the fuel cell main body 1 is supplied. In general, the electromotive force E of the fuel cell is apparent from the following Nernst equation (1), but it is known that the higher the hydrogen and oxygen partial pressures, the higher the temperature.

(Equation 1)
E = 2.3026 × {R · T / 2 · F} × log ₁₀ {PH2 / PO2 ^0.5 } (1)
Here, R: gas constant 8.31 [J / mol · K]
F: Faraday constant 96485 [C / mol]
T: Temperature [K]
PH2: Hydrogen partial pressure on the fuel electrode side [kPa_abs]
PO2: Oxygen partial pressure on the oxidizer electrode side [kPa_abs]
The oxidant electrode upper limit pressure that does not exceed the withstand voltage of the load device 40 is set in advance by experimentally obtaining the relationship between the “air pressure on the oxidant electrode 1a side” and the “fuel cell voltage” beforehand. It is possible. Further, by adding “temperature inside the fuel cell main body 1” to the relationship between “air pressure on the oxidant electrode 1a side” and “fuel cell voltage”, the oxidant electrode top is changed according to the temperature inside the fuel cell main body 1. Change the limiting pressure. For example, as shown in FIG. 3, the higher the temperature in the fuel cell body 1, the lower the oxidant electrode upper limit pressure value is set.

  As described above, the fuel cell system and the fuel cell system activation method according to the present embodiment include the fuel electrode 1b and the oxidant electrode 1a arranged with the electrolyte membrane 102 interposed therebetween, and the fuel electrode 1b and the oxidant electrode. A fuel cell main body 1 that generates power by an electrochemical reaction of a fuel gas and an oxidant gas respectively supplied to 1a, a hydrogen system (fuel gas supply means) that supplies fuel gas to the fuel electrode 1b, and an oxidant electrode 1a. In a fuel cell system having an air system (oxidant gas supply means) for supplying an oxidant gas, the target value of the fuel gas pressure at the fuel electrode 1b is normally set by the fuel gas pressure setting means in the controller 43 at the time of startup. The fuel gas pressure is adjusted by setting the pressure higher than the time, and the oxidant gas in the oxidant electrode 1a is adjusted by the oxidant gas pressure setting means in the controller 43. The target pressure value is not less than the oxidant electrode lower limit pressure value determined from the inter-membrane allowable pressure difference of the electrolyte membrane 102, and not more than the oxidant electrode upper limit pressure value at which the output voltage of the fuel cell body 1 is less than or equal to a predetermined value. Adjust the oxidant pressure by setting

  As described above, the fuel electrode 1b side to be replaced with the fuel gas (hydrogen gas) has a high fuel gas pressure, and the oxidant electrode 1a side which does not need the oxidant gas pressure has a low oxidant gas pressure. The withstand voltage of the load device 40 can be set low. Furthermore, since the pressure of the oxidant gas on the oxidant electrode 1a side is set to a pressure that keeps it within the allowable value of the transmembrane pressure difference, the durability of the fuel cell body 1 (electrolyte membrane 102, etc.) can be improved.

  In the fuel cell system and the fuel cell system start-up method of this embodiment, the internal temperature of the fuel cell main body 1 is detected by the temperature detection means (the fuel cell is detected from the temperature detection result using the cooling water thermometer 34 of the cooling water system). The temperature in the main body 1 is estimated), and the oxidant gas pressure setting means changes the oxidant electrode upper limit pressure value according to the temperature detection result. That is, the higher the temperature inside the fuel cell, the higher the cell voltage of the fuel cell. Therefore, the higher the temperature in the fuel cell main body 1, the higher the oxidant electrode lower limit pressure value is set. Thereby, the fuel cell voltage depending on the temperature can be dealt with, and even if the temperature changes, the fuel cell voltage does not exceed a predetermined value.

  Further, in the fuel cell system and the fuel cell system start-up method of the present embodiment, the temperature detection means detects the internal temperature of the fuel cell main body 1 (the fuel cell is detected from the temperature detection result using the cooling water thermometer 34 of the cooling water system). The temperature in the main body 1 is estimated), and the oxidant gas pressure setting means changes the oxidant extreme lower limit pressure value according to the temperature detection result. That is, the higher the temperature inside the fuel cell, the smaller the allowable pressure difference between the membranes. Therefore, the higher the temperature in the fuel cell body 1, the lower the oxidant electrode lower limit pressure value is set. Accordingly, it is possible to cope with the allowable transmembrane pressure difference depending on the temperature, and even when the temperature changes, the transmembrane pressure difference can be suppressed within the allowable value.

  Next, a fuel cell system and a fuel cell system activation method according to Embodiment 2 of the present invention will be described. The configuration of the fuel cell system of Example 2 is the same as that of Example 1 (FIG. 1), and a specific description of each component is omitted.

  However, the voltmeter 41 corresponds to the output voltage detection means for detecting the output voltage of the fuel cell main body 1, and the target value of the oxidant gas pressure at the oxidant electrode 1 a is determined by the oxidant gas pressure setting means in the controller 43. The oxidant electrode upper limit pressure value at which the output voltage of the fuel cell main body 1 becomes a predetermined value or less is set, and the target value of the oxidant gas pressure is set according to the detection result of the output voltage of the fuel cell main body 1 by the voltmeter 41. The correction is different from the first embodiment.

  Next, a starting method in the fuel cell system of this embodiment and a method for setting the pressure of the oxidant electrode 1a and the fuel electrode 1b at the time of starting will be described with reference to FIGS. Here, FIG. 5 is an explanatory diagram for explaining the temporal transition of the fuel electrode gas pressure and the oxidant electrode gas pressure set by the method for starting the fuel cell system of this embodiment, and FIG. It is explanatory drawing explaining the time transition of 1 output voltage.

  Since the pressure setting on the fuel electrode 1b side is equivalent to that in the first embodiment, the description thereof is omitted.

  Next, the pressure setting on the oxidant electrode 1a side is performed as follows. Air is supplied from the air compressor 11, and the target value of the oxidant gas pressure at the oxidant electrode 1 a is set to the target value of the oxidant gas pressure at the oxidant electrode 1 a by the oxidant gas pressure setting means of the controller 43. The limit pressure value (in this embodiment, the oxidizer electrode upper limit pressure value at which the output voltage of the fuel cell body 1 does not exceed the withstand voltage of the load device 40, and the upper limit by the voltage indicated by the broken line in FIG. 5) is set. For example, the actual pressure measured by the air pressure gauge 34 is adjusted by the air pressure regulating valve 15.

  Further, when the output voltage of the fuel cell main body 1 detected by the voltmeter 41 is likely to exceed the withstand voltage of the load device 40 (upper limit voltage indicated by a broken line in FIG. 6), feedback control is performed, and the oxidant electrode The target value of the oxidant pressure in 1a is lowered (actual pressure is lowered), and the output voltage of the fuel cell main body 1 is lowered. When the fuel cell voltage decreases, the target value of the pressure of the oxidizer electrode 1a is increased again.

As described above, in the fuel cell system and the fuel cell system activation method of this embodiment, the oxidant gas pressure setting means in the controller 43 sets the target value of the oxidant gas pressure at the oxidant electrode 1a to the fuel cell body. 1 is set to an oxidant electrode upper limit pressure value at which the output voltage of 1 is equal to or less than a predetermined value, and the target value of the oxidant gas pressure is corrected according to the detection result of the output voltage of the fuel cell main body 1 by the voltmeter 41. As described above, the oxidant gas pressure at the oxidant electrode 1a is set to the oxidant electrode upper limit pressure at which the transmembrane pressure difference becomes small, and the target value of the oxidant gas pressure at the oxidant electrode 1a is feedback controlled according to the output voltage. Therefore, as shown in FIG. 6, the output voltage of the fuel cell body 1 does not exceed the upper limit value (withstand voltage of the load device 40). Further, as shown in FIG. 5, there is a sufficient margin with respect to the lower limit pressure determined by the transmembrane differential pressure between the oxidant electrode 1a and the fuel electrode 1b, and the durability of the fuel cell body 1 (electrolyte membrane or the like) is improved. be able to.

it can.

  Next, a fuel cell system and a fuel cell system activation method according to Embodiment 3 of the present invention will be described. The configuration of the fuel cell system of Example 3 is the same as that of Example 1 (FIG. 1), and a specific description of each component is omitted.

  However, as shown in the partial configuration diagram around the load device 40 in FIG. 7, the load device 40 (for example, an inverter device) includes a battery 44 that stores surplus power from the fuel cell, and a battery voltage that detects the remaining power of the battery 44. A meter (battery remaining power detection means) 45 is added, and in the oxidant gas pressure setting means in the controller 43, the target value of the oxidant gas pressure at the oxidant electrode 1a is the same as in the first embodiment. Is set within a predetermined pressure range from the oxidant electrode lower limit pressure value to the oxidant electrode upper limit pressure value, but the target value of the oxidant gas pressure is corrected according to the remaining battery power detected by the battery voltmeter 45. This is different from the first embodiment.

  Next, a starting method in the fuel cell system of the present embodiment and a method for setting the pressure of the oxidant electrode 1a and the fuel electrode 1b at the time of starting will be described with reference to FIG. Here, FIG. 8 is an explanatory diagram for explaining the temporal transition of the fuel electrode gas pressure and the oxidant electrode gas pressure set by the method for starting the fuel cell system of the present embodiment.

  Since the pressure setting on the fuel electrode 1b side is equivalent to that in the first embodiment, the description thereof is omitted.

  Next, the pressure setting on the oxidant electrode 1a side is performed as follows. Air is supplied from the air compressor 11, the target value of the oxidant gas pressure at the oxidant electrode 1 a is set in the same manner as in the first embodiment by the oxidant gas pressure setting means of the controller 43, and is measured by the air pressure gauge 34. The air pressure regulating valve 15 is adjusted so that the pressure is within the predetermined pressure range.

  At this time, if the remaining battery power is estimated (preliminarily obtained experimentally) from the battery voltage detected by the battery voltmeter 45, if it is determined that the remaining battery power is not sufficient to start up, The target value of the oxidant gas pressure at the oxidant electrode 1a exceeds the oxidant electrode lower limit pressure value that does not damage the electrolyte film 102 beyond the differential pressure resistance of the electrolyte film 102 in accordance with the remaining battery power. Set it low. It should be noted that the remaining battery power, the pressure that can be set as the oxidant gas pressure in the oxidizer electrode 1a, and the determination of whether or not to start based on the remaining battery power can be experimentally determined in advance.

  As described above, in the fuel cell system and the fuel cell system activation method according to the present embodiment, the load device 40 stores the battery 44 that stores surplus power from the fuel cell, and the battery voltmeter 45 that detects the remaining power of the battery 44. In the oxidant gas pressure setting means in the controller 43, the target value of the oxidant gas pressure at the oxidant electrode 1a is corrected according to the remaining battery power detected by the battery voltmeter 45.

  As described above, the function of correcting the target value of the oxidant gas pressure in the oxidant electrode 1a according to the remaining battery power is provided, and the correction to the oxidant electrode pressure at the start-up is performed according to the remaining battery power. Therefore, the power consumption of the oxidant gas supply means (such as the air compressor 11 and the blower) can be suppressed, and the operation can be started even if the remaining battery power is low.

  For example, when the remaining power amount of the battery that covers the power consumption at the time of startup is insufficient to start up, the power consumption can be suppressed in the startup in which the target value of the oxidant gas pressure at the oxidant electrode 1a is set low. Therefore, it is possible to avoid the fact that it cannot be started. Normally, as in the second embodiment, the target value of the oxidant gas pressure at the oxidant electrode 1a is controlled near the oxidant electrode upper limit pressure value determined from the withstand voltage of the load device 40, and the remaining battery power is Since the target value of the oxidant gas pressure is set to a low value only when the amount is small, the influence on the durability of the fuel cell main body 1 (electrolyte membrane or the like) can be reduced.

  Next, a fuel cell system and a fuel cell system activation method according to Embodiment 4 of the present invention will be described. The configuration of the fuel cell system of Example 4 is the same as that of Example 1 (FIG. 1), and a specific description of each component is omitted.

  However, as shown in the configuration diagram of the vehicle to which the fuel cell system of Example 4 in FIG. 9 is applied, the fuel cell system 60 in FIG. 1 is mounted on the fuel cell vehicle 50, and the cooling water system is cooled. A radiator fan 51 and an air conditioner 52 for promoting heat radiation from the water pump 31 and the heat exchanger 33 are provided. Further, in the oxidant gas pressure setting means in the controller 43, as in the first embodiment, the target value of the oxidant gas pressure at the oxidant electrode 1a is set to a predetermined value from the oxidant electrode lower limit pressure value to the oxidant electrode upper limit pressure value. Although set within the pressure range, the target value of the oxidant gas pressure is determined according to the operation / non-operation or operation state of auxiliary equipment other than the oxidant gas supply means (cooling water pump 31, radiator fan 51, air conditioner 52, etc.). The point which correct | amends is different from Example 1. FIG.

  Next, a starting method in the fuel cell system of the present embodiment and a method for setting the pressure of the oxidant electrode 1a and the fuel electrode 1b at the time of starting will be described with reference to FIG. Here, FIG. 10 is an explanatory diagram for explaining the temporal transition of the fuel electrode gas pressure and the oxidant electrode gas pressure set by the method for starting the fuel cell system of the present embodiment.

  Since the pressure setting on the fuel electrode 1b side is equivalent to that in the first embodiment, the description thereof is omitted.

  Next, the pressure setting on the oxidant electrode 1a side is performed as follows. Air is supplied from the air compressor 11, the target value of the oxidant gas pressure at the oxidant electrode 1 a is set in the same manner as in the first embodiment by the oxidant gas pressure setting means of the controller 43, and is measured by the air pressure gauge 34. The air pressure regulating valve 15 is adjusted so that the pressure is within the predetermined pressure range.

  At this time, if the auxiliaries other than the oxidant gas supply means (such as the air compressor 11 and the blower), in this case, the cooling water pump 31, the radiator fan 51, and the air conditioner 52 are operating, the operating auxiliary devices are operating. The target value of the oxidant gas pressure at the oxidizer electrode 1a exceeds the differential pressure resistance of the electrolyte membrane 102 in accordance with the number of machinery and the load (for example, the rotational speed) of the operating auxiliary machinery. Is set to a low value within the range of the oxidant minimum lower limit pressure value that will not cause damage. Note that the settable pressure for the target value of the oxidant gas pressure at the oxidant electrode 1a is experimentally determined in advance so that the total sound vibration level of the auxiliary machinery and the sound vibration level of the air compressor 11 are the same. I can leave.

  As described above, in the fuel cell system and the fuel cell system activation method according to the present embodiment, the oxidant gas pressure setting means in the controller 43 is supplemented by means other than the oxidant gas supply means (such as the air compressor 11 and the blower). The target value of the oxidant gas pressure at the oxidant electrode 1a is corrected in accordance with the operation / non-operation or operation state of the machinery (cooling water pump 31, radiator fan 51, air conditioner 52, etc.).

  For example, when the auxiliary machinery (cooling water pump 31, radiator fan 51, air conditioner 52, etc.) is operating, the target value of the oxidant gas pressure at the oxidant electrode 1a is set to suppress noise and vibration. The noise and vibration of the oxidant gas supply means (air compressor 11, blower, etc.) can be suppressed by setting it low, and the entire fuel cell system 60 and the apparatus (fuel cell vehicle 50) to which the fuel cell system is applied can be suppressed. Sound and vibration can be suppressed. In addition, since the sound vibration level of the entire fuel cell vehicle 50 can be kept substantially constant every time it is started, the driver does not feel uncomfortable. Further, when the auxiliary equipment other than the air compressor 11 is non-operating, or when the auxiliary equipment is operating and operating at a low load, the oxidant electrode 1a as in the second embodiment is used. Since the target value of the oxidant gas pressure can be controlled in the vicinity of the oxidant electrode upper limit pressure value determined from the withstand voltage of the load device 40, the durability of the fuel cell body 1 (electrolyte membrane or the like) is improved.

  In the above description, the cooling water pump 31, the radiator fan 51, and the air conditioner 52 are shown as auxiliary equipment other than the oxidant gas supply means (such as the air compressor 11 and the blower). Needless to say.

  Next, a fuel cell system and a startup method of the fuel cell system according to Embodiment 5 of the present invention will be described. The configuration of the fuel cell system of Example 4 is the same as that of Example 1 (FIG. 1), and a specific description of each component is omitted.

  However, in the controller 43, a fuel gas pressure increasing means for increasing the fuel gas pressure at the fuel electrode 1b based on the setting of the fuel gas pressure setting means, and an oxidant gas pressure at the oxidant electrode 1a based on the setting of the oxidant gas pressure setting means. And an oxidant gas pressure boosting unit that boosts the pressure when the fuel gas pressure of the fuel electrode 1b reaches a predetermined value determined from the transmembrane allowable pressure by the fuel gas pressure boosting unit. The starting point is different from the first embodiment.

  Next, a startup method and a startup boosting method in the fuel cell system of the present embodiment will be described with reference to FIGS. 11 and 12. Here, FIG. 11 is an explanatory diagram for explaining the temporal transition of the fuel electrode gas pressure and the oxidant electrode gas pressure set by the method for starting the fuel cell system of this embodiment, and FIG. 12 shows this embodiment. 6 is a flowchart for explaining a method for boosting the fuel cell system during startup.

  First, supply of hydrogen as a fuel gas is started, and in order to eliminate the uneven distribution of the fuel gas in the fuel electrode 1b, the fuel gas pressure increase means starts to increase the fuel gas pressure in the fuel electrode 1b (step S11).

  Next, it is determined whether or not the fuel gas pressure of the fuel electrode 1b is equal to or higher than a predetermined value PS1 (step S12). In this determination, if the fuel gas pressure of the fuel electrode 1b is equal to or higher than the predetermined value PS1 (Yes), the process proceeds to step S13. If the fuel gas pressure of the fuel electrode 1b is less than the predetermined value PS1 (No), the process proceeds to step S11. Return. Here, the predetermined value PS1 is the pressure of the fuel electrode 1b at which the differential pressure between the oxidant electrode 1a and the fuel electrode 1b becomes the allowable transmembrane pressure.

  Next, when it is determined in step S12 that the fuel gas pressure of the fuel electrode 1b has reached the predetermined value PS1 (time T13), in order not to apply the transmembrane pressure difference, the supply of air is started, and the oxidant gas The oxidant gas pressure of the oxidant electrode 1a is increased by the pressure raising means (step S13). Even in the rising process, the differential pressure between the oxidant electrode 1a and the fuel electrode 1b is set to be within the allowable transmembrane pressure.

  Next, it is determined whether or not the fuel gas pressure of the fuel electrode 1b has increased to a pressure (predetermined value PS2) that can suppress the uneven distribution of gas in the fuel electrode 1b (step S14). When the fuel gas pressure of the fuel electrode 1b has increased to the predetermined value PS2 (Yes: time T14), the process proceeds to step S16, and when the fuel gas pressure of the fuel electrode 1b has not increased to the predetermined value PS2 (No), the process proceeds to step S16. In S13, the pressure is continuously increased.

  Next, it is determined whether or not the oxidant gas pressure of the oxidant electrode 1a has been increased to a predetermined value PS3 (step S15). When the oxidant gas pressure of the oxidant electrode 1a is increased to the predetermined value PS3 (Yes: time T15), the process proceeds to step S17, and the oxidant gas pressure of the oxidant electrode 1a is not increased to the predetermined value PS3 (No). In this case, the boosting is continued in step S13. Here, the predetermined value PS3 is a value set in any one of the first to fourth embodiments.

  Next, in step S16, since the fuel gas pressure of the fuel electrode 1b has been increased to a pressure (predetermined value PS2) that can suppress the uneven distribution of gas in the fuel electrode 1b, the boosting of the fuel electrode 1b is terminated. Also in step S17, since the oxidant pressure of the oxidant electrode 1a is increased to the predetermined value PS3, the increase of the oxidant electrode 1b is finished.

  As described above, in the fuel cell system and the fuel cell system activation method according to the present embodiment, the controller 43 increases the fuel gas pressure boosting means (in which the fuel gas pressure in the fuel electrode 1b is boosted based on the setting of the fuel gas pressure setting means ( And an oxidant gas pressure increasing unit (oxidant gas pressure increasing step) for increasing the oxidant gas pressure in the oxidant electrode 1a based on the setting of the oxidant gas pressure setting means, and an oxidant gas The pressure increasing means (oxidant gas pressure increasing step) starts pressure increasing when the fuel gas pressure at the fuel electrode 1b reaches a predetermined value determined from the inter-membrane allowable pressure difference by the fuel gas pressure increasing means (fuel gas pressure increasing step).

  As described above, when the pressure increase of the oxidant gas pressure of the oxidant electrode 1a is delayed with respect to the fuel electrode 1b side and reaches a predetermined value determined from the transmembrane allowable pressure difference, the oxidant gas pressure of the oxidant electrode 1a Therefore, the rate of increase in the output voltage of the fuel cell main body 1 can be reduced, and the effect of facilitating the response by the control can be obtained. For example, when the feedback control is performed according to the output voltage of the fuel cell main body 1 as in the second embodiment, there is an advantage that the control response is easy. Further, since the pressure can be increased so as to maintain the allowable pressure difference between the membranes, the durability of the fuel cell main body 1 (electrolyte membrane or the like) is improved. It can protect the transmembrane pressure difference.

  Next, a fuel cell system and a method for starting the fuel cell system according to Embodiment 6 of the present invention will be described. The configuration of the fuel cell system of Example 6 is the same as that of Example 1 (FIG. 1), and a specific description of each component is omitted.

  However, the controller 43 further comprises a fuel gas pressure reducing means for reducing the fuel gas pressure at the fuel electrode 1b and an oxidant gas pressure reducing means for reducing the oxidant gas pressure at the oxidant electrode 1a. Is different from the first embodiment in that the pressure reduction starts when the fuel gas pressure of the fuel electrode 1b becomes a predetermined value or less by the fuel gas pressure reduction means.

  Next, a start-up method in the fuel cell system of this embodiment and a step-down method when transitioning from the high-pressure state at the start-up to the normal operation will be described with reference to FIGS. 13 and 14. Here, FIG. 13 is an explanatory view for explaining the temporal transition of the fuel electrode gas pressure and the oxidant electrode gas pressure set by the method for starting the fuel cell system of this embodiment, and FIG. 5 is a flowchart for explaining a method for stepping down the fuel cell system in FIG.

  First, the fuel gas pressure reducing means starts to decrease the fuel gas pressure on the fuel electrode 1b side (step S21). The timing T21 at which the step-down is started is a timing at which the uneven distribution of the fuel gas at the fuel electrode is eliminated, and is set by, for example, the time from the fuel gas supply.

  Next, it is determined whether or not the fuel gas pressure of the fuel electrode 1b is equal to or less than a predetermined value PS3 (step S22). If the fuel gas pressure of the fuel electrode 1b is equal to or lower than the predetermined value PS3 (Yes), the process proceeds to step S23. If the fuel gas pressure of the fuel electrode 1b exceeds the predetermined value PS3 (No), the process returns to step S21. Continue to step down. Here, the predetermined value PS3 is a value set in any one of the first to fourth embodiments, but when the differential pressure is constantly applied to the oxidizer electrode 1a and the fuel electrode 1b during normal operation. But it doesn't matter.

  Next, when it is determined in step S22 that the fuel gas pressure of the fuel electrode 1b is equal to or less than the predetermined value PS3, the oxidant gas pressure reducing means starts to decrease the oxidant gas on the oxidant electrode 1a side (step S23). .

  Next, it is determined whether or not the pressure of the oxidant electrode 1a and the fuel electrode 1b is equal to or lower than a predetermined value PS4 (step S24). When the pressures of the oxidant electrode 1a and the fuel electrode 1b are equal to or lower than the predetermined value PS4 (Yes), the process proceeds to step S25, and when the pressures of the oxidant electrode 1a and the fuel electrode 1b are not equal to or lower than the predetermined value PS4 (No). In step S23, the step-down is continued. Here, the predetermined value PS4 is the pressure of the oxidant electrode 1a and the fuel electrode 1b during normal operation.

  Further, when the pressures of the oxidant electrode 1a and the fuel electrode 1b reach a predetermined value PS4 (pressure for normal operation), the respective pressure reductions are finished (step S25).

  As described above, in the fuel cell system and the fuel cell system start-up method according to the present embodiment, the controller 43 reduces the fuel gas pressure in the fuel electrode 1b (fuel gas pressure-lowering step) and the oxidizer. An oxidant gas pressure reducing means (oxidant gas pressure reducing step) for reducing the oxidant gas pressure at the pole 1a, and the oxidant gas pressure reducing means (oxidant gas pressure reducing step) is a fuel gas pressure reducing means (fuel gas pressure reducing step). When the fuel gas pressure of the fuel electrode 1b becomes equal to or lower than a predetermined value by step (step), pressure reduction is started.

  In this way, in the process of stepping down from the high pressure state at the time of startup to the normal operation, the pressure reduction of the oxidant gas pressure of the oxidant electrode 1a is delayed with respect to the fuel electrode 1b side, and the fuel gas pressure of the fuel electrode 1b is increased between the membranes. Since the pressure reduction of the oxidant gas pressure of the oxidant electrode 1a is started when the pressure becomes less than a predetermined value determined from the allowable differential pressure, the output voltage of the fuel cell body 1 does not increase, and the transmembrane pressure difference Since the time for attaching is short, the durability of the fuel cell main body 1 (electrolyte membrane) is improved.

  That is, when the pressure drop on the oxidant electrode 1a side is delayed with respect to the fuel electrode 1b, the time for applying the transmembrane pressure difference can be shortened. For example, when the pressure reduction on the oxidizer electrode 1a side is performed simultaneously with the pressure reduction on the fuel electrode 1b, as shown by the two-dot chain line shown in FIG. 13, between step S21 (time T21) and step S25 (time T25). Extra pressure will be applied. Further, the output voltage itself of the fuel cell main body 1 also reduces the fuel gas pressure on the fuel electrode 1b side, so there is no problem even if the oxidant gas pressure on the oxidant electrode 1a side is not reduced at the time of step S21. From the above, the time during which the differential pressure is applied between the membranes can be shortened, and the durability of the fuel cell (electrolyte membrane etc.) is improved.

1 is a configuration diagram of a fuel cell system according to an embodiment of the present invention. 1 is a conceptual diagram of a unit cell of a fuel cell main body 1. It is explanatory drawing explaining the time transition of the fuel electrode gas pressure and oxidant electrode gas pressure which are set by the starting method of the fuel cell system of Example 1. FIG. 3 is an explanatory diagram for explaining the temporal transition of the output voltage of the fuel cell main body 1 according to the first embodiment. It is explanatory drawing explaining the time transition of the fuel electrode gas pressure and oxidant electrode gas pressure which are set by the starting method of the fuel cell system of Example 2. FIG. 6 is an explanatory diagram for explaining the temporal transition of the output voltage of the fuel cell main body 1 of Example 2. 2 is a partial configuration diagram around a load device 40. FIG. It is explanatory drawing explaining the time transition of the fuel electrode gas pressure and oxidant electrode gas pressure which are set by the starting method of the fuel cell system of Example 3. It is a block diagram of the vehicle with which the fuel cell system of Example 4 is applied. It is explanatory drawing explaining the time transition of the fuel electrode gas pressure and oxidant electrode gas pressure which are set by the starting method of the fuel cell system of Example 4. It is explanatory drawing explaining the time transition of the fuel electrode gas pressure and oxidant electrode gas pressure which are set by the starting method of the fuel cell system of Example 5. 10 is a flowchart illustrating a startup pressure boosting method for a fuel cell system according to a fifth embodiment. It is explanatory drawing explaining the time transition of the fuel electrode gas pressure and oxidant electrode gas pressure which are set by the starting method of the fuel cell system of Example 6. 12 is a flowchart illustrating a method for stepping down a fuel cell system according to a sixth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Combustion battery body 1a Oxidant electrode 1b Fuel electrode 11 Air compressor 12 Air supply path 13 Air humidifier 14 Air exhaust path 15 Air pressure regulating valve 16 Air pressure gauge 21 High pressure hydrogen tank 22 Hydrogen supply path 23 Hydrogen pressure regulating valve 24 Hydrogen circulation Device 25 Hydrogen humidifier 26 Hydrogen circulation path 27 Hydrogen exhaust path 28 Hydrogen discharge valve 29 Hydrogen pressure gauge 31 Cooling water pump 32 Cooling water circulation path 33 Heat exchanger 34 Cooling water thermometer 40 Load device 41 Voltmeter 42 Ammeter 43 Controller 44 Battery 45 Battery Voltmeter 50 Fuel Cell Vehicle 51 Radiator Fan 52 Air Conditioner 100 Fuel Cell Single Cell 101 MEA
DESCRIPTION OF SYMBOLS 102 Electrolyte membrane 103 Fuel electrode catalyst layer 104 Oxidant electrode catalyst layer 105 Fuel electrode gas diffusion layer 106 Oxidant electrode gas diffusion layer 107,108 Separator 109 Fuel gas flow path 110 Oxidant gas flow path

Claims (16)

A fuel cell comprising a fuel electrode and an oxidant electrode arranged with an electrolyte membrane interposed therebetween, and generating power by an electrochemical reaction of a fuel gas and an oxidant gas respectively supplied to the fuel electrode and the oxidant electrode;
Fuel gas supply means for supplying fuel gas to the fuel electrode;
An oxidant gas supply means for supplying an oxidant gas to the oxidant electrode;
Fuel gas pressure setting means for setting a target value of the fuel gas pressure at the fuel electrode to a pressure higher than normal at the time of startup;
The target value of the oxidant gas pressure at the oxidant electrode is not less than the oxidant electrode lower limit pressure value determined from the allowable pressure difference between the electrolyte membranes, and the output voltage of the fuel cell is not more than a predetermined value. Oxidant gas pressure setting means for setting so as to be equal to or lower than the maximum pressure limit;
A fuel cell system comprising: Temperature detecting means for detecting the internal temperature of the fuel cell;
2. The fuel cell system according to claim 1, wherein the oxidant gas pressure setting unit changes the oxidant electrode upper limit pressure value according to a detection result of the temperature detection unit. 3. Temperature detecting means for detecting the internal temperature of the fuel cell;
3. The fuel according to claim 1, wherein the oxidant gas pressure setting unit changes the oxidant minimum lower limit pressure value according to a detection result of the temperature detection unit. 4. Battery system. Output voltage detecting means for detecting the output voltage of the fuel cell;
The oxidant gas pressure setting means sets the target value of the oxidant gas pressure at the oxidant electrode to an oxidant electrode upper limit pressure value at which the output voltage of the fuel cell is a predetermined value or less, and the output voltage detection means The fuel cell system according to any one of claims 1 to 3, wherein a target value of the oxidant gas pressure is corrected in accordance with the detection result. A battery for storing surplus power from the fuel cell;
Battery remaining power detection means for detecting the remaining power of the battery,
The oxidant gas pressure setting unit corrects a target value of the oxidant gas pressure at the oxidant electrode according to a detection result of the battery remaining power detection unit. The fuel cell system according to any one of claims.   The oxidant gas pressure setting means corrects a target value of the oxidant gas pressure at the oxidant electrode in accordance with the operation / non-operation or operation state of auxiliary equipment other than the oxidant gas supply means. The fuel cell system according to any one of claims 4 and 5. Fuel gas boosting means for boosting the fuel gas pressure at the fuel electrode based on the setting of the fuel gas pressure setting means;
An oxidant gas pressure raising means for raising the oxidant gas pressure at the oxidant electrode based on the setting of the oxidant gas pressure setting means,
2. The oxidant gas pressurizing unit starts boosting when the fuel gas pressure of the fuel electrode reaches a predetermined value determined from a transmembrane allowable pressure by the fuel gas pressurizing unit. The fuel cell system according to claim 6. Fuel gas pressure reducing means for reducing the fuel gas pressure in the fuel electrode;
An oxidant gas pressure reducing means for reducing the oxidant gas pressure at the oxidant electrode,
8. The oxidant gas pressure reducing means starts pressure reduction when the fuel gas pressure at the fuel electrode becomes a predetermined value or less by the fuel gas pressure reducing means. 2. The fuel cell system according to item 1. A fuel cell comprising a fuel electrode and an oxidant electrode arranged with an electrolyte membrane interposed therebetween, and generating power by an electrochemical reaction of a fuel gas and an oxidant gas respectively supplied to the fuel electrode and the oxidant electrode;
Fuel gas supply means for supplying fuel gas to the fuel electrode;
An oxidant gas supply means for supplying an oxidant gas to the oxidant electrode;
A fuel cell system start-up method in which the fuel gas pressure at the fuel electrode at start-up is set to a pressure higher than normal,
The target value of the oxidant gas pressure at the oxidant electrode is not less than the oxidant electrode lower limit pressure value determined from the allowable pressure difference between the electrolyte membranes, and the output voltage of the fuel cell is not more than a predetermined value. A starting method for a fuel cell system, characterized in that the fuel cell system is set to be equal to or lower than an extreme upper limit pressure value. The fuel cell system has temperature detection means for detecting an internal temperature of the fuel cell,
The method for starting a fuel cell system according to claim 9, wherein the oxidant electrode upper limit pressure value is changed in accordance with a detection result of the temperature detection means. The fuel cell system has temperature detection means for detecting an internal temperature of the fuel cell,
11. The method for starting a fuel cell system according to claim 9, wherein the oxidant minimum lower limit pressure value is changed in accordance with a detection result of the temperature detection means. 11. The fuel cell system has output voltage detection means for detecting an output voltage of the fuel cell,
The target value of the oxidant gas pressure at the oxidant electrode is set to the oxidant electrode upper limit pressure value at which the output voltage of the fuel cell is less than or equal to a predetermined value, and the oxidant according to the detection result of the output voltage detection means The method for starting a fuel cell system according to any one of claims 9 to 11, wherein a target value of the gas pressure is corrected. The fuel cell system includes:
A battery for storing surplus power from the fuel cell;
Battery remaining power detection means for detecting the remaining power of the battery,
The fuel cell according to any one of claims 9 to 12, wherein a target value of an oxidant gas pressure at the oxidant electrode is corrected according to a detection result of the battery remaining power detection unit. How to start the system.   14. The target value of the oxidant gas pressure at the oxidant electrode is corrected according to the operation / non-operation or operation state of auxiliary equipment other than the oxidant gas supply means. The start method of the fuel cell system according to any one of the above. A fuel gas boosting step for boosting the fuel gas pressure at the fuel electrode based on the setting of the fuel gas pressure setting means;
An oxidant gas pressure increasing step for increasing the oxidant gas pressure at the oxidant electrode based on the setting of the oxidant gas pressure setting means,
The oxidant gas pressurization step starts pressure increase when the fuel gas pressure of the fuel electrode reaches a predetermined value determined from the transmembrane allowable pressure by the fuel gas pressurization step. The method for starting a fuel cell system according to claim 14. A fuel gas pressure reducing step for reducing the fuel gas pressure at the fuel electrode;
An oxidant gas pressure reducing step for reducing the oxidant gas pressure at the oxidant electrode,
16. The oxidant gas pressure reduction step starts pressure reduction when the fuel gas pressure of the fuel electrode becomes a predetermined value or less by the fuel gas pressure reduction step. 2. A method for starting a fuel cell system according to item 1.

Images