JP2010033900A - Fuel cell system and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system that allows an output to build up smoothly at the start of a fuel cell, and to provide an electronic device. <P>SOLUTION: If an output voltage detected by an output voltage detecting unit 6 does not reach a reference voltage with the initial supply of fuel at the start of a fuel cell generating unit 101 even after a predetermined period of time has elapsed, the fuel supply is repeated. Once the output voltage has reached the reference voltage, an output current detected by an output detecting unit 6 within a certain period of time has reached a reference current; and once the heating temperature of the fuel cell generating unit 101 detected by a temperature sensor 106 has reached a first reference temperature, the fuel supply to the fuel cell generating unit 101 is shifted to steady operation. If the heating temperature of the fuel cell generating unit 101 does not reach the first reference temperature, fuel is additionally supplied to the fuel cell generating unit 101 when an increment (ΔI) in the output current is less than zero. When the first reference temperature is not reached even though the additional supply of fuel is repeated, the fuel supply to the fuel cell generating unit 101 is shifted to the steady operation. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell system and an electronic apparatus using the fuel cell system as a power source.

  There have been remarkable miniaturizations of electronic devices such as mobile phones and portable information terminals, and along with the miniaturization of these electronic devices, attempts have been made to use fuel cells as a power source. A fuel cell has the advantage that it can generate electricity only by supplying fuel and air, and can generate electricity continuously by replacing only the fuel. Therefore, if it can be downsized, it can be used as a power source for small electronic devices. It is valid.

  Therefore, a direct methanol fuel cell (hereinafter, referred to as DMFC; Direct Methanol Fuel Cell) has attracted attention as a fuel cell. Such DMFCs are classified according to the liquid fuel supply system, such as an active system such as a gas supply type and a liquid supply type, and an internal vaporization type that vaporizes the liquid fuel in the fuel storage section inside the battery and supplies it to the fuel electrode. Among these, the passive type is particularly advantageous for reducing the size of the DMFC.

  Conventionally, as such a passive DMFC, as disclosed in Patent Document 1, for example, a membrane electrode assembly (fuel cell) having a fuel electrode, an electrolyte membrane, and an air electrode is removed from a resin box-like container. The thing of the structure arrange | positioned on the fuel accommodating part which becomes is considered.

Patent Documents 2 to 4 also disclose a configuration in which a DMFC fuel cell and a fuel storage unit are connected via a flow path. In these Patent Documents 2 to 4, by supplying the liquid fuel supplied from the fuel storage portion to the fuel cell via the flow path, the supply amount of the liquid fuel can be adjusted based on the shape and diameter of the flow path. In particular, in Patent Document 3, liquid fuel is supplied from the fuel storage portion to the flow path by a pump. Further, it is described that an electric field forming means for forming an electroosmotic flow in the flow path is used instead of the pump. Furthermore, Patent Document 4 describes that liquid fuel or the like is supplied using an electroosmotic pump.
International Publication No. 2005/112172 Pamphlet JP 2005-518646 A JP 2006-089552 A US Patent Publication No. 2006/0029851

  By the way, when such a fuel cell system using the DMFC as a main power generation unit is applied as a power source of a small electronic device, it is important to smoothly start up the output when the fuel cell is activated.

  Conventionally, when the fuel cell is started, the operation time of each of the on-timer and off-timer that determines whether the fuel supply pump is turned on or off is set, and the fuel supply amount to the fuel cell power generation unit is adjusted to adjust the fuel cell The output is started up.

  However, in such a method, since fuel is supplied to all fuel cells at a uniform timing, variations in the amount of fuel supplied by the fuel supply pump, individual differences in fuel cells, ambient environment (outside temperature), etc. For this reason, the fuel supply to the fuel cell power generation unit may become excessive. For this reason, the output voltage Vo of the fuel cell power generation unit rises rapidly in a short time from the start of fuel supply, for example, as indicated by A1 in FIG. 4A, and the heat generation temperature To of the fuel cell power generation unit is As shown in B1 of b), the reference temperature TA may be exceeded and the upper limit temperature TB may be exceeded, which may adversely affect electronic components incorporating the system. On the other hand, if the fuel supply to the fuel cell power generation unit may be insufficient, this time from the start of fuel supply until the heat generation temperature at the fuel cell power generation unit reaches the reference temperature and a predetermined control voltage is output. There was also a problem that it took a lot of time and the usability as a power source for electronic devices was lowered.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a fuel cell system and an electronic device that can realize a smooth start-up of an output when the fuel cell is started.

  According to the first aspect of the present invention, a fuel cell main body having a power generation unit that generates electric power from fuel, temperature detecting means for detecting the temperature of the fuel cell main body, and an output voltage and an output current of the fuel cell main body are detected. Output detecting means, and control means for controlling fuel supply to the fuel cell main body from startup of the fuel cell main body to steady operation, wherein the control means is an initial supply of fuel when the fuel cell main body is started up If the output voltage detected by the output detection means does not reach the reference voltage even if a predetermined time elapses, the fuel supply is repeated a predetermined number of times. When the output voltage reaches the reference voltage, the output detection is performed within a predetermined time. When the output current detected by the means reaches a reference current, and the heat generation temperature of the fuel cell body detected by the temperature detection means reaches the reference temperature, the fuel supply of the fuel cell body If the heat generation temperature of the fuel cell main body does not reach the reference temperature, the fuel cell main body additionally supplies fuel to the fuel cell main body when the output current increase (ΔI) is ΔI <0. If the reference temperature is not reached even after repeated fuel supply, the fuel supply of the fuel cell main body is controlled to shift to a steady operation.

  According to a second aspect of the present invention, there is provided a fuel cell main body having a power generation unit that generates electric power using fuel, temperature detecting means for detecting the temperature of the fuel cell main body, and detecting an output voltage and an output current of the fuel cell main body. Output detecting means, and control means for controlling fuel supply to the fuel cell main body from startup of the fuel cell main body to steady operation, wherein the control means is an initial supply of fuel when the fuel cell main body is started up If the output voltage detected by the output detection means does not reach the reference voltage even if a predetermined time elapses, the fuel supply is repeated a predetermined number of times. When the output voltage reaches the reference voltage, the output detection is performed within a predetermined time. Control is performed so that the fuel supply of the fuel cell main body shifts to steady operation when the output current detected by the means reaches the reference current.

  According to a third aspect of the present invention, there is provided a fuel cell main body having a power generation unit for generating electric power from fuel, temperature detecting means for detecting the temperature of the fuel cell main body, and detecting an output voltage and an output current of the fuel cell main body. Output detecting means, and control means for controlling fuel supply to the fuel cell main body from start-up of the fuel cell main body to steady operation, wherein the control means is an initial stage of fuel when the fuel cell main body is started up. If the heat generation temperature of the fuel cell main body detected by the temperature detection means by supply does not reach the reference temperature, the increase (ΔI) of the output current detected by the output detection means is ΔI <0 and the fuel cell main body The fuel supply to the fuel cell main body is controlled so as to shift to a steady operation when the reference temperature is not reached even if the additional fuel supply is repeated. Yes.

  According to a fourth aspect of the present invention, in the first or third aspect of the present invention, the control unit may perform additional supply of fuel to the fuel cell main body at a predetermined temperature at which the heat generation temperature of the fuel cell main body is lower than the reference temperature. It is characterized by being executed on the condition that it is even lower.

  A fifth aspect of the present invention is an electronic device using the fuel cell system according to any one of the first to fourth aspects as a power source.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel cell system and electronic device which can implement | achieve the smooth start-up of the output at the time of fuel cell starting can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows a schematic configuration of a fuel cell system according to a first embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a fuel cell main body (DMFC). The fuel cell main body 1 includes a fuel cell power generation unit (cell) 101 that constitutes an electromotive unit, a fuel storage unit 102 that stores liquid fuel, and a fuel storage unit 102. And a flow path 103 connecting the fuel cell power generation unit (cell) 101 and a pump 104 as a fuel supply control means for transferring liquid fuel from the fuel storage unit 102 to the fuel cell power generation unit (cell) 101. .

  FIG. 2 is a cross-sectional view for explaining the fuel cell main body 1 in more detail.

  In this case, the fuel cell power generation unit 101 includes an anode (fuel electrode) 13 having an anode catalyst layer 11 and an anode gas diffusion layer 12, and a cathode (air electrode / oxidation) having a cathode catalyst layer 14 and a cathode gas diffusion layer 15. The electrode assembly 16 has a membrane electrode assembly (MEA) composed of a proton (hydrogen ion) conductive electrolyte membrane 17 sandwiched between the anode catalyst layer 11 and the cathode catalyst layer 14. ing.

  Here, examples of the catalyst contained in the anode catalyst layer 11 and the cathode catalyst layer 14 include a simple substance of a platinum group element such as Pt, Ru, Rh, Ir, Os, and Pd, an alloy containing the platinum group element, and the like. It is done. For the anode catalyst layer 11, it is preferable to use Pt—Ru, Pt—Mo, or the like having strong resistance to methanol, carbon monoxide, or the like. Pt, Pt—Ni or the like is preferably used for the cathode catalyst layer 14. However, the catalyst is not limited to these, and various substances having catalytic activity can be used. The catalyst may be either a supported catalyst using a conductive support such as a carbon material or an unsupported catalyst.

  Examples of the proton conductive material constituting the electrolyte membrane 17 include fluorine-based resins (Nafion (trade name, manufactured by DuPont) and Flemion (trade name, manufactured by Asahi Glass Co., Ltd.) such as a perfluorosulfonic acid polymer having a sulfonic acid group. Etc.), organic materials such as hydrocarbon resins having sulfonic acid groups, or inorganic materials such as tungstic acid and phosphotungstic acid. However, the proton conductive electrolyte membrane 17 is not limited to these.

  The anode gas diffusion layer 12 laminated on the anode catalyst layer 11 serves to uniformly supply fuel to the anode catalyst layer 11 and also serves as a current collector for the anode catalyst layer 11. The cathode gas diffusion layer 15 laminated on the cathode catalyst layer 14 serves to uniformly supply the oxidant to the cathode catalyst layer 14 and also serves as a current collector for the cathode catalyst layer 14. The anode gas diffusion layer 12 and the cathode gas diffusion layer 15 are made of a porous substrate.

  A conductive layer is laminated on the anode gas diffusion layer 12 and the cathode gas diffusion layer 15 as necessary. As these conductive layers, for example, a porous layer (for example, mesh) made of a conductive metal material such as Au or Ni, a porous film, a foil body, a conductive metal material such as stainless steel (SUS), gold or the like. A composite material coated with a highly conductive metal is used. Rubber O-rings 19 are interposed between the electrolyte membrane 17 and a fuel distribution mechanism 105 and a cover plate 18, which will be described later, thereby preventing fuel leakage and oxidant leakage from the fuel cell power generation unit 101. is doing.

  The cover plate 18 has an opening (not shown) for taking in air as an oxidant. A moisture retaining layer and a surface layer are disposed between the cover plate 18 and the cathode 16 as necessary. The moisturizing layer is impregnated with a part of the water generated in the cathode catalyst layer 14 to suppress the transpiration of water and promote uniform diffusion of air to the cathode catalyst layer 14. The surface layer adjusts the amount of air taken in, and has a plurality of air inlets whose number, size, etc. are adjusted according to the amount of air taken in.

  A fuel distribution mechanism 105 is disposed on the anode (fuel electrode) 13 side of the fuel cell power generation unit 101. A fuel storage unit 102 is connected to the fuel distribution mechanism 105 via a liquid fuel flow path 103 such as a pipe.

  Liquid fuel corresponding to the fuel cell power generation unit 101 is stored in the fuel storage unit 102. Examples of the liquid fuel include methanol fuels such as aqueous methanol solutions of various concentrations and pure methanol. The liquid fuel is not necessarily limited to methanol fuel. The liquid fuel may be, for example, an ethanol fuel such as an ethanol aqueous solution or pure ethanol, a propanol fuel such as a propanol aqueous solution or pure propanol, a glycol fuel such as a glycol aqueous solution or pure glycol, dimethyl ether, formic acid, or other liquid fuel. In any case, liquid fuel corresponding to the fuel cell power generation unit 101 is stored in the fuel storage unit 102.

  Fuel is introduced into the fuel distribution mechanism 105 from the fuel storage portion 102 via the flow path 103. The flow path 103 is not limited to piping independent of the fuel distribution mechanism 105 and the fuel storage unit 102. For example, when the fuel distribution mechanism 105 and the fuel storage unit 102 are stacked and integrated, a fuel flow path connecting them may be used. The fuel distribution mechanism 105 only needs to be connected to the fuel storage unit 102 via the flow path 103.

  Here, as shown in FIG. 3, the fuel distribution mechanism 105 includes at least one fuel inlet 21 through which fuel flows through the flow path 103 and a plurality of fuel outlets 22 through which fuel and its vaporized components are discharged. The fuel distribution plate 23 having As shown in FIG. 2, a gap 24 serving as a fuel passage led from the fuel inlet 21 is provided inside the fuel distribution plate 23. The plurality of fuel discharge ports 22 are directly connected to gaps 24 that function as fuel passages.

  The fuel introduced into the fuel distribution mechanism 105 from the fuel inlet 21 enters the gap portion 24 and is guided to the plurality of fuel discharge ports 22 through the gap portion 24 functioning as the fuel passage. For example, a gas-liquid separator (not shown) that transmits only the vaporized component of the fuel and does not transmit the liquid component may be disposed in the plurality of fuel discharge ports 22. As a result, the fuel vaporization component is supplied to the anode (fuel electrode) 13 of the fuel cell power generation unit 101. The gas-liquid separator may be installed as a gas-liquid separation membrane or the like between the fuel distribution mechanism 105 and the anode 13. The vaporized component of the fuel is discharged from a plurality of fuel discharge ports 22 toward a plurality of locations on the anode 13.

A plurality of fuel discharge ports 22 are provided on the surface of the fuel distribution plate 23 in contact with the anode 13 so that fuel can be supplied to the entire fuel cell power generation unit 101. The number of the fuel discharge ports 22 may be two or more. However, in order to equalize the fuel supply amount in the plane of the fuel cell power generation unit 101, the fuel discharge ports 22 of 0.1 to 10 / cm ² are provided. It is preferable to form it so that it exists.

  A pump 104 serving as a fuel transfer control unit is inserted into a flow path 103 that connects between the fuel distribution mechanism 105 and the fuel storage unit 102. The pump 104 is not a circulation pump through which fuel is circulated, but is a fuel supply pump that transfers fuel from the fuel storage unit 102 to the fuel distribution mechanism 105 to the last. By supplying the fuel when necessary with such a pump 104, the controllability of the fuel supply amount is improved. In this case, a rotary vane pump, an electroosmotic pump, a diaphragm pump, a squeezing pump, etc. should be used as the pump 104 from the viewpoint that a small amount of fuel can be sent with good controllability and can be reduced in size and weight. Is preferred. A rotary vane pump feeds liquid by rotating a wing with a motor. The electroosmotic flow pump uses a sintered porous material such as silica that causes an electroosmotic flow phenomenon. The diaphragm pump is a pump that feeds liquid by driving the diaphragm with an electromagnet or piezoelectric ceramics. The squeezing pump presses a part of the flexible fuel flow path and squeezes the fuel. Among these, it is more preferable to use an electroosmotic pump or a diaphragm pump having piezoelectric ceramics from the viewpoint of driving power, size, and the like.

  In addition, a fuel supply control circuit 5 described later is connected to the pump 104, and the drive of the pump 104 is controlled. This point will be described later.

  In such a configuration, the fuel stored in the fuel storage unit 102 is transferred through the flow path 103 by the pump 104 and supplied to the fuel distribution mechanism 105. The fuel released from the fuel distribution mechanism 105 is supplied to the anode (fuel electrode) 13 of the fuel cell power generation unit 101. In the fuel cell power generation unit 101, the fuel diffuses through the anode gas diffusion layer 12 and is supplied to the anode catalyst layer 11. When methanol fuel is used as the fuel, an internal reforming reaction of methanol shown in the following formula (1) occurs in the anode catalyst layer 11. When pure methanol is used as the methanol fuel, the water generated in the cathode catalyst layer 14 or the water in the electrolyte membrane 17 is reacted with methanol to cause the internal reforming reaction of the formula (1). Alternatively, the internal reforming reaction is caused by another reaction mechanism that does not require water.

CH ₃ OH + H ₂ O → CO ₂ + 6H ⁺ + 6e ⁻ (1)
Electrons (e ⁻ ) generated by this reaction are guided to the outside via a current collector, supplied to the load side as so-called output, and then guided to the cathode (air electrode) 16. Further, protons (H ⁺ ) generated by the internal reforming reaction of the formula (1) are guided to the cathode 16 through the electrolyte membrane 17. Air is supplied to the cathode 16 as an oxidant. Electrons (e ⁻ ) and protons (H ⁺ ) that have reached the cathode 16 react with oxygen in the air according to the following equation (2) in the cathode catalyst layer 14, and water is generated with this reaction.

6e ⁻ + 6H ⁺ + (3/2) O ₂ → 3H ₂ O (2)
Returning to FIG. 1, in the fuel cell main body 1 configured in this way, the fuel cell power generation unit (cell) 101 is provided with a temperature sensor 106 as second temperature detection means. The temperature sensor 106 detects the temperature of the heat generating part of the fuel cell power generation unit (cell) 101, and is composed of, for example, a thermistor or a thermocouple, and is the cathode (air) of the fuel cell power generation unit (cell) 101 shown in FIG. Pole) 16. Further, the temperature sensor 106 outputs a detection signal corresponding to the heat generation temperature to the control unit 7. The controller 7 will be described later.

  The fuel cell body 1 is connected to an output detection unit 6 and a DC-DC converter (voltage adjustment circuit) 2 as output adjustment means. The output detection unit 6 detects the output voltage Vo and the output current Io as outputs of the fuel cell power generation unit (cell) 101, and outputs detection signals respectively corresponding to the output voltage Vo and the output current Io to the control unit 7.

  The DC-DC converter 2 includes a switching element and an energy storage element (not shown). The DC-DC converter 2 stores / releases electric energy generated by the fuel cell body 1 by the switching element and the energy storage element, An output generated by boosting a relatively low output voltage to a sufficient voltage is generated. The output of the DC-DC converter 2 is supplied to the auxiliary power supply 4.

  Although the standard boost type DC-DC converter 2 is shown here, other circuit systems can be used as long as the boost operation is possible.

  An auxiliary power supply 4 is connected to the output end of the DC-DC converter 2. The auxiliary power supply 4 can be charged by the output of the DC-DC converter 2 and supplies a current to an instantaneous load fluctuation of the electronic device main body 3, and the fuel cell is in a fuel-depleted state. When the main body 1 is incapable of generating power, it is used as a driving power source for the electronic device main body 3. As the auxiliary power source 4, a chargeable / dischargeable secondary battery (for example, a lithium ion rechargeable battery (LIB)) or an electric double layer capacitor) is used.

  A fuel supply control circuit 5 is connected to the auxiliary power source 4. The fuel supply control circuit 5 controls the operation of the pump 104 using the auxiliary power source 4 as a power source, and controls the pump 104 on / off based on an instruction from the control unit 7.

  A controller 7 is connected to the fuel supply control circuit 5.

  The control unit 7 controls the entire system, and includes an output setting unit 701, a reference temperature setting unit 702, a timer 703, and a pump control signal generation unit 704. The output setting unit 701 stores a reference voltage, a reference current, and the like, which are operation reference values when the fuel cell is activated. The reference temperature setting unit 702 stores each reference temperature set in the period from the start of the fuel cell body 1 to the steady operation. The timer 703 counts each preset time when the fuel cell is activated, and also operates as an on-timer that determines the on-time of the pump 104 and an on-timer that determines the off-time of the pump 104. The pump control signal generation unit 704 outputs an on signal that determines the operation time of the pump 104 and an off signal that determines the stop time of the pump 104 according to the on timer and the operation of the on timer, and the detection of the output detection unit 6 The comparison result between the signal and each set value of the output voltage and output current stored in the output setting unit 701, the comparison result between the output of the temperature sensor 106 and the reference temperature stored in the reference temperature setting unit 702, and the count of the timer 703 An on / off signal of the pump 104 is output according to the value or the like.

  Next, the operation of the embodiment configured as described above will be described.

  Now, according to the start instruction of the fuel cell system, the flowchart shown in FIG.

  First, in step 501, an initial supply of fuel to the pump 104 is instructed. The fuel supply in this case is executed only for a first predetermined time with the pump 104 ON signal output from the pump control signal generator 704 and the pump 104 at the maximum flow rate. The generation time of the ON signal at this time is counted by the timer 703. Then, when the first predetermined time has elapsed, the routine proceeds to step 502.

  In step 502, it is determined whether the output voltage has reached the reference voltage within a second predetermined time (for example, three times the first predetermined time) from the start. This determination is made based on a comparison result between the detection signal (output voltage Vo) of the output detection unit 6 and the reference voltage stored in the output setting unit 701. If NO is determined here, the process proceeds to step 503. In step 503, it is determined whether the initial supply of fuel is the third time. In this case, if NO, the process returns to step 501 to perform the initial fuel supply for the second time, and thereafter, in step 502, until it is determined that the output voltage has reached the reference voltage within the second predetermined time, step The operations 501 to 503 are repeated. Thereafter, when it is determined in step 503 that the initial supply of fuel is the third time by such repeated operation, the process proceeds to step 504, where it is processed as a start error of the fuel cell system. That is, the initial supply of fuel to the pump 104 is repeated up to three times, and if the output voltage still does not reach the reference voltage, it is determined that power supply to the electronic device main body 3 is difficult and error processing is performed.

  On the other hand, if it is determined in step 502 that the output voltage has reached the reference voltage within the second predetermined time, the process proceeds to step 505. In step 505, power supply to the electronic device main body 3, that is, a load is started, and it is determined whether the output current has exceeded the reference current within a third predetermined time that is slightly more than three times the second predetermined time from the start. . The determination in this case is made based on a comparison result between the detection signal (output current Io) of the output detection unit 6 and the reference current stored in the output setting unit 701. If it is determined NO, it is determined that power supply to the electronic device main body 3 is difficult, and error processing is performed (step 506). On the other hand, if YES is determined, the process proceeds to step 507. In step 507, it is determined whether the heat generation temperature of the fuel cell power generation unit (cell) 101 is lower than the first reference temperature of the reference temperature. In this case, the heat generation temperature of the fuel cell power generation unit (cell) 101 is acquired from the detection signal of the temperature sensor 106. Further, the first reference temperature is stored in advance in the reference temperature setting unit 702.

  Here, if it is determined that the heat generation temperature of the fuel cell power generation unit (cell) 101 detected by the temperature sensor 106 is smaller than the reference temperature and YES, that is, by the initial fuel supply from step 501 to step 505 described above. If the reference temperature during steady operation, here, the first reference temperature is not reached, the process proceeds to step 508. In step 508, it is determined whether the increase (ΔI) in the output current is zero continuously for a fourth predetermined time or more. At this time, the timer 703 counts for the fourth predetermined time or longer.

  If YES is determined here, the heat generation temperature of the fuel cell power generation unit (cell) 101 is lower than the first predetermined temperature slightly lower than the first reference temperature at this timing (step 509). , Go to Step 510. The first predetermined temperature in this case is also stored in the reference temperature setting unit 702 in advance. Step 509 is for confirming that the temperature is at a first predetermined temperature slightly lower than the first reference temperature in order to prevent an excessive increase in temperature due to the additional fuel supply.

  In step 510, it is determined whether the additional fuel supply is the fourth time. If NO here, the process proceeds to step 511, the pump control signal generator 704 outputs an ON signal of the pump 104, and the pump 104 is operated for a time similar to the first predetermined time, for example, to add fuel. Supply. In step 512, after confirming that the second predetermined time has elapsed, the process returns to step 507 to determine whether the heat generation temperature of the fuel cell power generation unit (cell) 101 is lower than the first reference temperature. At this time, the generation time of the ON signal of the pump 104 and the elapsed time of the second predetermined time after the additional supply of fuel are counted by the timer 703.

  In this state, if the heat generation temperature of the fuel cell power generation unit (cell) 101 is higher than the first reference temperature and is determined to be N0, the process proceeds to the steady operation mode after step 513. The steady operation will be described later. On the other hand, in step 507, since the heat generation temperature of the fuel cell power generation unit (cell) 101 is still lower than the first reference temperature, if it is determined as N0, the operation after step 508 described above is executed. In this case, if it is determined in step 508 that the increase (ΔI) in the output current is not zero continuously for the fourth predetermined time or longer and NO, the process returns to step 507 and again the fuel cell power generation unit (cell ) If the heat generation temperature of 101 is lower than the reference temperature, and if the heat generation temperature of the fuel cell power generation unit (cell) 101 is higher than the first reference temperature and is determined to be N0, the steady state after step 513 is determined. Transition to operation mode. On the other hand, if it is determined in step 508 that the increase (ΔI) in the output current continues to be zero for a fourth predetermined time or longer and YES is determined, additional fuel supply after step 509 is further executed. Thereafter, when it is determined in step 510 that the additional fuel supply is the fourth time by such repeated operation, that is, when the first reference temperature during steady operation is not reached even in the four additional fuel supply times. Then, it is determined that the flow rate of the pump 104 is small and there is no possibility of overheating, and the routine proceeds to the steady operation mode of step 513.

  In the steady operation mode after step 513, first, in step 514, it is determined whether the heat generation temperature of the fuel cell power generation unit (cell) 101 has dropped below the first reference temperature. Here, if NO, the steady operation is continued in this state.

  Thereafter, when the heat generation temperature of the fuel cell power generation unit (cell) 101 falls below the first reference temperature, YES is determined in step 514 and the process proceeds to step 515. In step 515, the timer 703 is operated as an on-timer, and an on-operation for a fifth predetermined time is started. In this case, the pump control signal generation unit 704 outputs an ON signal of the pump 104 to supply fuel to the fuel cell power generation unit (cell) 101. In step 516, it is determined whether the heat generation temperature of the fuel cell power generation unit (cell) 101 has risen above the second reference temperature within the fifth predetermined time of the on-timer. The second reference temperature here is stored in advance in the reference temperature setting unit 702.

  If YES is determined in the step 516, the process proceeds to a step 517. In step 517, the on-timer is reset to stop the operation of the pump 104, and the process returns to step 514. On the other hand, if it is determined as NO in step 516 without the heat generation temperature of the fuel cell power generation unit (cell) 101 rising above the second reference temperature within the fifth predetermined time, the process proceeds to step 518.

  In step 518, the timer 703 is operated as an off timer, and the operation for a sixth predetermined time (for example, three times the fifth predetermined time) is started. In this case, the pump control signal generating unit 704 outputs an off signal of the pump 104 to stop the fuel supply to the fuel cell power generation unit (cell) 101. Then, the process proceeds to step 519, where it is determined whether the heat generation temperature of the fuel cell power generation unit (cell) 101 has risen to the second reference temperature or more within the sixth predetermined time. If the heat generation temperature rises above the second reference temperature and it is determined YES, the process proceeds to step 517, the off timer is reset, and the operation of the pump 104 is stopped and the process returns to step 514.

  On the other hand, if it is determined in step 519 that the exothermic temperature of the fuel cell power generation unit (cell) 101 does not rise above the second reference temperature within the sixth predetermined time, the process proceeds to step 520. In step 520, when the sixth predetermined time is counted by the off timer, the process proceeds to step 517, the off timer is reset, and the operation of the pump 104 is stopped, and the process returns to step 514.

  Therefore, in this way, the initial supply of fuel to the fuel cell power generation unit (cell) 101 at the time of starting the fuel cell system is performed in multiple times until a predetermined reference voltage is output within a predetermined time. The fuel supply at startup is always the optimum amount. In this case, the amount of fuel per supply to the fuel cell power generation unit (cell) 101 by the pump 104 is Q1 (where Q1 is a variable value: the minimum Q1min to the maximum Q1max including various conditions and variations), the fuel When the amount of fuel required by the battery power generation unit (cell) 101 at startup is Q2 (where Q2 is a fixed value: minimum Q2min to maximum Q2max including various conditions and variations), fuel at the initial startup The supply is set to Q1max ≦ Q2min so that Q1 ≦ Q2 is always satisfied. If the output voltage does not reach the reference voltage even after the second predetermined time has elapsed due to the fuel supply, the above-described fuel supply is performed again. Here, if the reference voltage is not reached even when Q1min × the number of times of supply (for example, 3 times), it is processed as an error, and if the reference voltage is reached, the power supply to the electronic device body 3, that is, the load is applied. Start. Further, even after the load is started, if the output current does not reach the reference current within the third predetermined time, it is treated as an error, and when the reference current is reached, the transition to the steady operation mode is enabled. I made it. In this case, the output voltage Vo of the fuel cell power generation unit (cell) 101 increases over a relatively long time from the start of fuel supply as shown by A2 in FIG. The heat generation temperature To of the battery power generation unit (cell) 101 also increases over time from the start of fuel supply and is controlled based on the reference temperature TA, as indicated by B2 in FIG. There is no longer a rise beyond TB. As a result, the initial supply of fuel is adjusted to the optimum amount even if there are various causes such as variations in the amount of fuel supplied by the pump 104, individual differences in the fuel cell power generation unit (cell) 101, and the surrounding environment (outside temperature). It is possible to realize a smooth start-up of the output at the time of start-up, so that the heat generation temperature in the fuel cell power generation unit (cell) 101 rises abnormally beyond the upper limit temperature TB, and an electronic component incorporating the system, etc. It is possible to reliably prevent situations that adversely affect the system.

  In addition, the heat generation temperature of the fuel cell power generation unit (cell) 101 is monitored in the course of the initial fuel supply, and control is performed so that the heat generation temperature in the fuel cell power generation unit (cell) 101 at the time of startup is always optimal. I made it. In this case, the heat generation temperature of the fuel cell power generation unit (cell) 101 is monitored, and if the heat generation temperature reaches the first reference temperature, the operation mode is quickly shifted to the steady operation mode, while the first reference temperature is not reached. In this case, if the increase (ΔI) in the output current is ΔI <0, additional fuel is supplied. The additional supply of fuel in this case is executed on condition that the heat generation temperature is further lower than the first predetermined temperature lower than the first reference temperature, and prevents an excessive increase in temperature due to the additional fuel supply. . If the first reference temperature is not reached even if the additional fuel supply is repeated a plurality of times (for example, four times), it is determined that there is no possibility of overheating, and the mode is shifted to the steady operation mode. . As a result, for example, the amount of fuel supplied to the fuel cell power generation unit (cell) 101 becomes insufficient during the initial fuel supply, and the heat generation temperature of the fuel cell power generation unit (cell) 101 does not rise to the first reference temperature and is output. If an increase in current cannot be obtained, the fuel cell power generation unit (cell) 101 can be raised to the reference temperature required for the steady operation mode by performing additional supply of fuel. Smooth and quick transition to the steady operation mode can be achieved, and usability can be improved as a power source for electronic equipment. Further, since the additional fuel supply is executed on condition that the heat generation temperature of the fuel cell power generation unit (cell) 101 is lower than the first reference temperature, the temperature rises excessively due to the additional fuel supply. Can also be reliably prevented.

(Modification 1)
In the first embodiment, the initial supply of fuel to the fuel cell power generation unit (cell) 101 at the start of the fuel cell system is performed in multiple times until a predetermined reference voltage is output within a predetermined time. Then, when the heat generation temperature of the fuel cell power generation unit (cell) 101 does not rise to the reference temperature and an increase in the output current cannot be obtained, additional fuel supply is performed. The initial supply of fuel to the fuel cell power generation unit (cell) 101 is executed in a plurality of times until a predetermined reference voltage is output within a predetermined time. In this process, the fuel cell power generation unit (cell) 101 When the reference voltage is reached, the load is started, and further, the output current reaches the reference current within a certain time after the start of the load, so that the mode immediately shifts to the steady operation mode.

  Even in this case, it becomes possible to adjust the initial supply of the fuel to the optimum amount, and the same effect as described in the first embodiment can be obtained.

(Modification 2)
In the first embodiment, the initial supply of fuel to the fuel cell power generation unit (cell) 101 at the start of the fuel cell system is performed in multiple times until a predetermined reference voltage is output within a predetermined time. Then, when the heat generation temperature of the fuel cell power generation unit (cell) 101 does not rise to the reference temperature and an increase in output current cannot be obtained, additional fuel supply is performed. If the heat generation temperature of the fuel cell power generation unit (cell) 101 does not reach the reference temperature in the initial supply of fuel at startup, additional fuel supply is performed when the increase in output current (ΔI) becomes ΔI <0, If the reference temperature is not reached even when such additional fuel supply is repeated a plurality of times, it is determined that there is no possibility of overheating, and the operation mode is shifted to the steady operation mode.

  Even in this case, it becomes possible to appropriately adjust the initial supply of fuel, and the same effect as described in the first embodiment can be obtained.

  In addition, this invention is not limited to the said embodiment, In the implementation stage, it can change variously in the range which does not change the summary. For example, the reference voltage and reference current set in the output setting unit 701, the reference temperature and predetermined temperature set in the reference temperature setting unit 702, and various times set in the timer 703 are determined by the fuel cell system actually used. It is set arbitrarily depending on the situation.

  Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and is described in the column of the effect of the invention. If the above effect is obtained, a configuration from which this configuration requirement is deleted can be extracted as an invention.

  Further, the vaporized component of the liquid fuel supplied to the fuel cell power generation unit may be all supplied as the vaporized component of the liquid fuel, but the present invention is applied even when a part is supplied in the liquid state. be able to.

1 is a diagram showing a schematic configuration of a fuel cell system according to a first embodiment of the present invention. Sectional drawing for demonstrating in detail the fuel cell main body of 1st Embodiment. The perspective view of the fuel distribution mechanism used for the fuel cell main body of 1st Embodiment. The figure for demonstrating operation | movement of 1st Embodiment. The flowchart for demonstrating operation | movement of 1st Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fuel cell main body, 101 ... Fuel cell electric power generation part 102 ... Fuel accommodating part, 103 ... Flow path 104 ... Pump, 105 ... Fuel distribution mechanism 106 ... Temperature sensor, 2 ... DC / DC converter, 3 ... Electronic equipment main body 4 ... Auxiliary power supply, 5 ... Fuel supply control circuit 6 ... Output detection unit, 7 ... Control unit,
701: Output setting unit, 702: Reference temperature setting unit,
703 ... Timer, 704 ... Pump control signal generator,
DESCRIPTION OF SYMBOLS 11 ... Anode catalyst layer, 12 ... Anode gas diffusion layer 13 ... Anode, 14 ... Cathode catalyst layer 15 ... Cathode gas diffusion layer, 16 ... Cathode 17 ... Electrolyte membrane, 18 ... Cover plate 19 ... O-ring, 21 ... Fuel inlet 22 ... Fuel discharge port, 23 ... Fuel distribution plate 24 ... Gap

Claims (5)

A fuel cell main body having a power generation unit for generating electric power from fuel;
Temperature detecting means for detecting the temperature of the fuel cell body;
Output detection means for detecting an output voltage and an output current of the fuel cell body;
Control means for controlling fuel supply to the fuel cell main body from start-up to steady operation of the fuel cell main body,
The control means repeats the fuel supply a predetermined number of times if the output voltage detected by the output detection means does not reach a reference voltage even after a predetermined time has elapsed due to the initial supply of fuel at the time of starting the fuel cell body, When the output voltage reaches the reference voltage, the output current detected by the output detection means reaches the reference current within a certain time, and the heating temperature of the fuel cell body detected by the temperature detection means reaches the reference temperature. Therefore, if the fuel supply of the fuel cell body is shifted to a steady operation and the heat generation temperature of the fuel cell body does not reach the reference temperature, the increase (ΔI) of the output current is ΔI <0 and the fuel cell body The fuel is supplied to the fuel cell, and if the reference temperature is not reached even if the additional fuel supply is repeated, the fuel supply of the fuel cell main body is controlled to shift to a steady operation. Fuel cell system. A fuel cell main body having a power generation unit for generating electric power from fuel;
Temperature detecting means for detecting the temperature of the fuel cell body;
Output detection means for detecting an output voltage and an output current of the fuel cell body;
Control means for controlling fuel supply to the fuel cell main body from start-up to steady operation of the fuel cell main body,
The control means repeats the fuel supply a predetermined number of times if the output voltage detected by the output detection means does not reach a reference voltage even after a predetermined time has elapsed due to the initial supply of fuel at the time of starting the fuel cell body, When the output voltage reaches the reference voltage, control is performed so that the fuel supply of the fuel cell main body shifts to a steady operation because the output current detected by the output detection means reaches the reference current within a predetermined time. A fuel cell system. A fuel cell main body having a power generation unit for generating electric power from fuel;
Temperature detecting means for detecting the temperature of the fuel cell body;
Output detection means for detecting an output voltage and an output current of the fuel cell body;
Control means for controlling fuel supply to the fuel cell main body from start-up to steady operation of the fuel cell main body,
The control means outputs the output detected by the output detection means when the heat generation temperature of the fuel cell main body detected by the temperature detection means by the initial supply of fuel at the start of the fuel cell main body does not reach a reference temperature. When the increase in current (ΔI) is ΔI <0, additional fuel is supplied to the fuel cell main body. If the reference temperature is not reached even after repeating the additional fuel supply, the fuel cell main body is supplied with fuel. A fuel cell system controlled to shift to a steady operation. The said control means performs the additional supply of the fuel to the said fuel cell main body on the condition that the heat_generation | fever temperature of the said fuel cell main body is still lower than the predetermined temperature lower than the said reference temperature, or characterized by the above-mentioned. 3. The fuel cell system according to 3. An electronic device using the fuel cell system according to claim 1 as a power source.

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