JP2006085970A - Fuel cell device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell device equipped with a structure for removing a foreign matter such as dust, salt water mist, and oil mist contained in the air supplied to the fuel cell generation part. <P>SOLUTION: The air introduced from an air intake port 8 formed at the case 7 by operation of an air supply pump 3 is sucked in the air supply pump 3 through a vapor liquid separation film 9 and/or an electrostatic filter 10, and then sent to the fuel cell power generation part 2. The vapor liquid separation film 9 and the electrostatic filter 10 can be installed selectively at the air intake port 8, the suction port of the air supply pump 3, and the air supply port of the fuel cell power generation part 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel cell device suitable as a power source for a portable device or the like that consumes a relatively large amount of power.

  As a power source for relatively small devices such as portable devices, DMFC (direct methanol fuel cell) is considered promising because of its relatively simple structure. This DMFC generates electricity by chemically reacting an aqueous methanol solution used as fuel with oxygen in the air via an electrolyte membrane. The supply of air is an active type that forcibly supplies air to the power generation unit, and natural circulation. There is a passive type that supplies air to the power generation unit. DMFC for portable devices (20-50W) with relatively high power consumption, such as personal computers, forcibly supplies a relatively large amount of air (5-10 L / min) to the power generation unit using an air pump. The active type is used. As a basic configuration of a DMFC using such an air supply pump, a configuration as shown in FIG. 6 is known (see Patent Document 1).

As shown in FIG. 6, a DMFC power generation unit 100 that generates electricity by reacting an aqueous methanol solution with air has an anode catalyst layer 122, an anode current collector 123 on one side, and a cathode on the other side, with an electrolyte membrane 110 at the center. The reaction layer is formed by laminating the catalyst layer 132 and the cathode current collector 133, the anode passage body 121 in which the methanol aqueous solution passage 120 is formed on the anode side of the reaction membrane, and the air passage 130 on the cathode side. The formed cathode channel body 131 is arranged. A methanol aqueous solution stored in the fuel cartridge 30 is supplied to the flow path 120 of the anode flow path body 121 by the liquid feed pump 41, and air is supplied to the flow path 130 of the cathode flow path body 131 from the air feed pump 42. The The methanol aqueous solution soaked into the anode catalyst layer 122 from the flow path 120 is subjected to a chemical reaction and undergoes a chemical reaction, and the generated protons pass through the electrolyte membrane 110 and react with the oxygen soaked into the cathode catalyst layer 132 to generate electric power. The generated power is taken out from the anode current collector 123 and the cathode current collector 133.
JP 2004-071259 A (pages 2 to 4, FIG. 2)

  When the fuel cell device such as DMFC shown as the above prior art is applied to, for example, a power source of a portable device, it is exposed to various environments because it is a portable device. That is, it is expected that the state of air taken into the fuel cell device as an oxidizer varies depending on the place where the portable device is carried, and dust, salt water mist, oil mist, etc. are included in the air. The air environment varies depending on where the fuel cell device is installed, not limited to portable devices.

  If air containing these foreign substances is taken into the fuel cell device, it may adhere to the inside of the air pump and reduce the pump performance. In addition, when air containing foreign matter passes through the air supply pump and is supplied to the fuel cell power generation unit, it may adhere to the reaction membrane and the air flow path and reduce power generation performance and battery life.

  The present invention was devised in view of the above-described problems of the prior art, and an object of the present invention is to provide a fuel cell device having a structure that suppresses adverse effects caused by foreign matter contained in the air. .

  In order to achieve the above object, the first invention of the present application includes a fuel cell power generation unit that generates electric power by chemically reacting fuel and air through an electrolyte membrane in a housing in which an air intake is formed, and the air A fuel cell device comprising an air pump that feeds air taken in from an intake port to the fuel cell power generation unit, the air intake port, from the air intake port to an intake port of the air feed pump A gas-liquid separation membrane that allows gas to pass therethrough and prevents liquid from passing is provided in at least one location of the air intake flow path, the air supply flow path from the discharge port of the air supply pump to the air supply port of the fuel cell power generation unit. It is characterized by.

  According to the configuration of the first aspect of the invention, even if foreign matter such as dust, salt water mist, and oil mist is contained in the air taken into the housing, the gas-liquid separation film prevents passage of the foreign matter and removes the foreign matter. Air is taken into the air supply pump or the fuel cell power generation unit, so that foreign matter adheres to the air supply pump to prevent the pump performance from deteriorating and pump locks. The air flow path and electrolyte membrane of the fuel cell power generation unit It is possible to prevent a decrease in power generation performance and battery life due to foreign matter adhering to the battery. Accordingly, it is possible to configure a fuel cell device with little performance deterioration over a long period of time, and in particular, it is possible to provide a fuel cell device suitable for application as a power source for portable equipment in which the air state changes.

  Further, the second invention of the present application takes in the fuel cell power generation unit that generates electric power by chemically reacting fuel and air through the electrolyte membrane in the casing in which the air intake is formed, and the air intake from the air intake. A fuel cell device that houses an air supply pump that supplies air to the fuel cell power generation unit, the air intake, an intake flow path from the air intake to the intake of the air supply pump, A gas-liquid separation membrane or an electrostatic filter for selectively allowing gas to pass therethrough and preventing passage of liquid is provided in an air supply passage extending from the discharge port of the air supply pump to the air supply port of the fuel cell power generation unit. It is characterized by this.

  According to the configuration of the second invention, even if foreign matter such as dust, salt water mist, oil mist is contained in the air taken into the housing, passage of the foreign matter is blocked by the gas-liquid separation membrane and the electrostatic filter, Since the air from which foreign matter has been removed is taken into the air pump or the fuel cell power generation unit, it is possible to prevent deterioration of pump performance and pump lock due to foreign matter adhering to the air supply pump. It is possible to prevent a decrease in power generation performance and battery life due to foreign matters adhering to the road and the electrolyte membrane. The gas-liquid separation membrane will need to be replaced because the trapping of foreign matter will lead to a decrease in the blowing pressure, but the combined use of an electrostatic filter may reduce the amount of foreign matter trapped by the gas-liquid separation membrane. It is possible to reduce the replacement frequency.

  In each of the above configurations, the gas-liquid separation membrane preferably has pores distributed in a region having an opening diameter of 0.1 to 10.0 μm, and has a pore diameter smaller than the particle diameter of dust or mist. Thus, air can be passed and dust can be reliably prevented.

  Further, in the configuration of the second invention, a gas-liquid separation membrane is provided at the air intake, and an electrostatic filter is provided at the intake flow path and / or the air supply flow path, so that the air is taken into the housing by the gas-liquid separation film. If foreign matter is removed from the air and an electrostatic filter is provided in the intake flow path, foreign matter present in the housing can be prevented from entering the air supply pump, and if an electrostatic filter is provided in the air supply flow path, it is generated from the air supply pump. Foreign matter such as wear powder can be prevented from entering the fuel cell power generation unit.

  In addition, by providing an electrostatic filter in the air intake and providing a gas-liquid separation membrane in the intake flow path and / or the air supply flow path, dust contained in the air taken into the housing is provided in the air intake. The gas-liquid separation film captured by the electrostatic filter and provided in the intake flow path and / or the air supply flow path prevents foreign substances such as mist from passing through, so clogging is caused by the accumulation of dust or the like on the gas-liquid separation film. Is suppressed.

  In addition, by providing a gas-liquid separation membrane in the intake flow channel and providing an electrostatic filter in the air supply flow channel, foreign substances can be removed from the air sucked into the air supply pump by the gas-liquid separation membrane. When wear powder or the like is discharged from the pump, passage is blocked by the electrostatic filter, so that air in which no foreign matter is mixed can be supplied to the fuel cell power generation unit.

  According to the present invention, foreign substances such as dust, salt water mist and oil mist contained in the air can be blocked by the gas-liquid separation membrane, so that the foreign substances enter the air feed pump and the fuel cell power generation unit. In addition, since the intrusion of foreign matter can be effectively prevented by the combined use with an electrostatic filter, the performance and life of the air pump and the fuel cell power generation unit are reduced and the required performance is maintained over a long period of time. In particular, it is possible to provide a fuel cell device suitable as a power source for a portable device in which the state of the inhaled air easily changes.

  FIG. 1 shows a configuration of a portable fuel cell stack 1 according to a first embodiment of the present invention. A fuel cell power generation unit 2 that generates power by reacting fuel and air, a liquid feed pump 6 that supplies liquid fuel such as an aqueous methanol solution stored in a liquid fuel tank 5 to the fuel cell power generation unit 2, and a fuel cell An air supply pump 3 that supplies air to the power generation unit 2 is housed in a housing 7.

  An air intake port 8 is formed on the side surface of the housing 7. When the air supply pump 3 is rotationally driven by a motor (not shown), air taken into the housing 7 from the air intake port 8 is supplied. The air is sucked from the suction port of the air pump 3, boosted to a predetermined pressure, discharged from the discharge port, and air is supplied to the fuel cell power generation unit 2 from the air supply line 4 connected between the discharge port and the fuel cell power generation unit 2. Is supplied. On the other hand, the fuel stored in the liquid fuel tank 5 is boosted to a predetermined pressure by driving the liquid feed pump 6 and supplied to the fuel cell power generation unit 2.

  The fuel cell power generation unit 2 is provided with a fuel flow path forming body in which a fuel flow path is formed on one side of a reaction film in which positive and negative catalyst layers and current collectors are formed on both sides of the electrolyte membrane. A fuel cell stack 1 is provided in which unit cells each having an air flow path forming body having an air flow path formed in a direction are stacked and connected in a plurality of stages, and the fuel supplied to the fuel flow path in each unit cell Electric power is generated by a chemical reaction with air supplied to the air flow path through the electrolyte membrane, and electric power generated in a plurality of unit cells is connected in series to output electric power of a required voltage. .

  In the active type fuel cell device that obtains an air supply amount corresponding to the power generation amount by forcibly supplying air by the air pump 3 as in the above configuration, the air taken into the housing 7 from the air intake 8 If foreign matter such as dust, salt water mist, and oil mist is contained therein, the foreign matter may adhere to the inside of the air pump 3 and deteriorate the pump performance of the air pump 3. In addition, if foreign matter that has passed through the air supply pump 3 is supplied to the fuel cell power generation unit 2 together with air, the foreign matter may adhere to the air flow path or the reaction membrane, leading to a reduction in power generation performance or battery life. is there.

  Therefore, it is necessary to remove foreign substances from the air flowing into the air feed pump 3 and the fuel cell power generation unit 2. If it is only dust, a filter that filters only air may be provided, but it cannot prevent the intrusion of salt water mist, oil mist, and the like. Therefore, as shown in the figure, it is effective to provide a gas-liquid separation membrane 9 at the air intake 8 serving as an inlet through which air flows, the intake port of the air supply pump 3, and the air supply port of the fuel cell power generation unit 2. Become. The gas-liquid separation membrane 9 is a membrane that allows gas to pass through but does not allow liquid to pass through, and a tetrafluoroethylene resin membrane or the like can be applied.

  The gas-liquid separation membrane 9 is preferably provided at the air intake 8 serving as an inlet through which air flows, the intake port of the air supply pump 3, and the air supply port of the fuel cell power generation unit 2 as described above. Considering the pressure loss during feeding, it is effective to provide at least one of the three locations. However, when the gas-liquid separation membrane 9 is provided only at the air supply port of the fuel cell power generation unit 2, it is impossible to prevent foreign matter from entering the air supply pump 3, so that the gas-liquid separation is performed at one location. When the separation membrane 9 is provided, the air intake 8 or the intake port of the air feed pump 3 is a preferable arrangement site. In addition, since it is necessary to replace the gas-liquid separation membrane 9 when clogging occurs, a portion that can be easily attached and detached is suitable. In the configuration shown in FIG. It is most preferable that the air intake 8 is provided. When it is provided at the suction port of the air pump 3, it can be arranged by being configured to be detachable from the outside of the housing 7.

  The gas-liquid separation membrane 9 is more effective for removing foreign substances as its pore diameter is smaller. However, the loss of the blowing pressure by the air feed pump 3 is increased, and the degree to which the pores are blocked by the trapped foreign substances is also increased. Since the filter life is shortened, it is preferable that the pore diameter is distributed in the region of 0.1 to 10 μm. That is, since the particle diameter of a mist such as salt water or oil is about 100 to 3000 μm, if the pore diameter is in the region, it is effective for removing foreign substances.

  As described above, providing the gas-liquid separation membrane 9 at the three locations of the air intake port 8, the intake port of the air supply pump 3, and the air supply port of the fuel cell power generation unit 2 is effective for removing foreign matters, Problems such as air pressure loss and replacement due to clogging occur. Therefore, it is effective to use the electrostatic filter 10 together with the gas-liquid separation film 9 as in the second to fifth embodiments shown in FIGS.

  In the configuration of the second embodiment shown in FIG. 2, the gas-liquid separation membrane 9 is disposed at the suction port of the air feed pump 3, and the electrostatic filter 10 is disposed at the air intake port 8. In this configuration, since the electrostatic filter 10 is provided in the air intake port 8 that is upstream of the air flow from the intake port of the air supply pump 3 provided with the gas-liquid separation membrane 9, the particle diameter of dust and the like is reduced. Large foreign matters are captured by the electrostatic filter 10, and foreign matters having a small particle diameter that cannot be captured by the electrostatic filter 10 can be captured by the gas-liquid separation membrane 9. Therefore, most of the foreign matter is removed by the electrostatic filter 10 provided at the air intake 8, so that the frequency of clogging in the gas-liquid separation membrane 9 can be greatly reduced. Since the provided electrostatic filter 10 is located on the outer surface of the housing 7 even when clogging occurs, it can be easily attached and detached.

  In the configuration of the third embodiment shown in FIG. 3, a gas-liquid separation membrane 9 is disposed at the air intake 8 and an electrostatic filter 10 is disposed at the suction port of the air feed pump 3. Since dust, salt water mist, oil mist, etc. contained in the air taken into the housing 7 from the air intake 8 are also removed by the gas-liquid separation film 9, it is greatly prevented that foreign matter enters the housing 7. Can be suppressed. Further, since the electrostatic filter 10 is provided at the suction port of the air supply pump 3, dust or the like that has entered the housing 7 when the fuel cell device is assembled may be sucked into the air supply pump 3 at the start of operation. In addition, it is possible to prevent the occurrence of a malfunction such as a pump lock due to a decrease in performance of the air feed pump 3 or a large amount of foreign matter inhaled.

  In the configuration of the fourth embodiment shown in FIG. 4, a gas-liquid separation membrane 9 is disposed at the air intake 8, and an electrostatic filter 10 is disposed at the air supply port of the fuel cell power generation unit 2. Since dust, salt water mist, oil mist, and the like are removed from the air taken into the housing 7 by the gas-liquid separation membrane 9 provided at the air intake 8, air containing no foreign matter is supplied to the fuel cell power generation unit 2. Can be sent. However, depending on the type of the air pump 3, some have a rotating part or a sliding part, which may generate wear powder. Therefore, the electrostatic filter 10 is provided at the air supply port of the fuel cell power generation unit 2. In this case, even when wear powder is discharged from the air supply pump 3, it can be prevented from entering the air flow path of the fuel cell power generation unit 2.

  In the configuration of the fifth embodiment shown in FIG. 5, the gas-liquid separation membrane 9 is disposed at the suction port of the air feed pump 3, and the electrostatic filter 10 is disposed at the air feed port of the fuel cell power generation unit 2. ing. Since dust, salt water mist, oil mist and the like contained in the air taken into the housing 7 are removed by the gas-liquid separation membrane 9 provided at the suction port of the air feed pump 3, foreign matter is removed from the air feed pump 3. Can be supplied to the fuel cell power generation unit 2. However, depending on the type of the air pump 3, some have a rotating part or a sliding part, which may generate wear powder. Therefore, the electrostatic filter 10 is provided at the air supply port of the fuel cell power generation unit 2. In this case, even when wear powder is discharged from the air supply pump 3, it can be prevented from entering the air flow path of the fuel cell power generation unit 2.

  Although not shown, in the configuration shown in FIG. 4, the electrostatic filter 10 can also be provided at the suction port of the air feed pump 3, and dust or the like existing in the housing 7 is sucked into the air feed pump 3. Can be prevented by the electrostatic filter 10, and when wear powder or the like is discharged from the air supply pump 3, the electrostatic filter 10 provided at the air supply port of the fuel cell power generation unit 2 Can be prevented from entering the air flow path, and a structure having a high dustproof effect can be obtained.

  In the configuration described above, the gas-liquid separation membrane 9 or the electrostatic filter 10 provided at the air supply port of the fuel cell power generation unit 2 is not necessarily an air supply port, but from the discharge port of the air supply pump 3 to the air supply port. It can also be provided in the air supply pipe line 4 leading to. In addition, the gas-liquid separation membrane 9 or the electrostatic filter 10 provided at the suction port of the air feed pump 3 is arranged in the pipe line when a pipe connection is formed as an air flow path from the air intake port 8 to the suction port. Even if installed, the same effect can be obtained.

  As described above, according to the present invention, foreign matter such as salt water mist and oil mist, as well as dust contained in the air supplied to the fuel cell power generation unit, enter the air supply pump and the fuel cell power generation unit. In addition, even when wear powder or the like is discharged from the air supply pump, it is possible to prevent them from entering the fuel cell power generation unit. A fuel cell device that can maintain the required performance over a long period of time with little reduction in life can be configured, and in particular, a configuration suitable as a fuel cell device applied to a portable device in which the state of the inhaled air is likely to change can be obtained.

The schematic diagram which shows the structure of the fuel cell apparatus which concerns on 1st Embodiment. The schematic diagram which shows the structure of the fuel cell apparatus which concerns on 2nd Embodiment. The schematic diagram which shows the structure of the fuel cell apparatus which concerns on 3rd Embodiment. The schematic diagram which shows the structure of the fuel cell apparatus which concerns on 4th Embodiment. The schematic diagram which shows the structure of the fuel cell apparatus which concerns on 5th Embodiment. The schematic diagram which shows the basic composition of the fuel cell which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell stack 2 Fuel cell power generation part 3 Air supply pump 4 Air supply line 5 Fuel tank 6 Liquid supply pump 7 Case 8 Air intake 9 Gas-liquid separation membrane 10 Electrostatic filter

Claims (6)

A fuel cell power generation unit that generates electric power by chemically reacting fuel and air through an electrolyte membrane in a housing in which an air intake port is formed, and air taken from the air intake port to the fuel cell power generation unit A fuel cell device comprising an air supply pump for supplying air, wherein the air intake port, an intake passage from the air intake port to an intake port of the air supply pump, and an exhaust port of the air supply pump A fuel cell device comprising a gas-liquid separation membrane that allows gas to pass therethrough and prevents liquid from passing through at least one portion of an air supply passage to an air supply port of a fuel cell power generation unit. A fuel cell power generation unit that generates electric power by chemically reacting fuel and air through an electrolyte membrane in a housing in which an air intake port is formed, and air taken from the air intake port to the fuel cell power generation unit A fuel cell device including an air supply pump for supplying air, wherein the air intake port, an intake passage extending from the air intake port to an intake port of the air supply pump, and an exhaust port of the air supply pump A fuel cell device, wherein a gas-liquid separation membrane or an electrostatic filter that allows gas to pass therethrough and prevents liquid from passing through is selectively provided in an air supply passage leading to an air supply port of the fuel cell power generation unit. . The fuel cell device according to claim 1 or 2, wherein the gas-liquid separation membrane is formed with pores distributed in a region having an opening diameter of 0.1 to 10.0 µm. The fuel cell device according to claim 2 or 3, wherein a gas-liquid separation membrane is provided at the air intake, and an electrostatic filter is provided in the intake flow path and / or the air supply flow path. The fuel cell device according to claim 2 or 3, wherein an electrostatic filter is provided at the air intake, and a gas-liquid separation membrane is provided in the intake flow path and / or the air supply flow path. The fuel cell device according to claim 2 or 3, wherein a gas-liquid separation membrane is provided in the intake passage, and an electrostatic filter is provided in the air supply passage.

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