JP2008130423A - Vapor/liquid separator and fuel cell using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor/liquid separator capable of separating the vapor from the liquid more efficiently, and to provide a fuel cell using it. <P>SOLUTION: A heat generating body such as a catalyst is installed at the inner wall 100b of a cabinet 100 and the outer wall 101b of a case 101. By installing the catalyst to react gas components discharged from a vapor/liquid separating membrane 102 via an exhaust port 101a, temperature in the case 101 can be raised by reaction heat generated by heat generating reaction of the catalyst. Since the case 101 is positioned so as to be surrounded by the cabinet 100, the heat generated in the cabinet 100 is efficiently transferred to the case 101. By raising the temperature in the case 101 by the reaction heat generated by the heat generation of the catalyst, the amount of saturated steam is increased, and agglomeration of water in the case 101 can be suppressed. Since the agglomeration of water is suppressed, it is prevented that efficiency of vapor/liquid separation is reduced due to the fact that water is adhered to the vapor/liquid separating membrane 102. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel cell, and more particularly to a gas-liquid separator.

  At present, secondary batteries such as lithium ion batteries are mainly used as power sources for portable electronic devices such as notebook personal computers and mobile devices. In recent years, a small fuel cell with high output and no need for charging has been expected as a new power source due to an increase in power consumption accompanying the enhancement of functions of these electronic devices and a request for longer use. There are various types of fuel cells. In particular, a direct methanol fuel cell (hereinafter referred to as DMFC) using a methanol solution as a fuel is easier to handle than a fuel cell using hydrogen as a fuel. And the system is simple. Since DMFC can reuse unused fuel discharged during power generation for power generation again, it is suitable as a power source for electronic devices that are compact and require long-time operation.

  In the fuel cell, a liquid fuel such as a methanol solution and air are supplied to the stack for power generation. Carbon dioxide and moist air generated in the power generation reaction and liquid fuel that has not been used in the power generation reaction are circulated in the fuel cell system, and the gas contained in the liquid is separated by the gas-liquid separation mechanism and discharged as a gas. Is done.

As a technique for separating a gas in a liquid, for example, one described in Patent Document 1 can be cited. Patent Document 1 discloses a gas-liquid separation member that selectively permeates a gas component in the discharge as a filter for removing harmful substances contained in the discharge from the electrode, and a gas component that has passed through the gas-liquid separation member. A filter having a catalyst portion for oxidative combustion is disclosed. The exhaust gas can be prevented from leaking outside through a path other than the catalyst portion, and harmful substances generated and discharged in the power generation reaction of the fuel cell can be purified.
JP 2005-183014 A

  However, in the case of the above-described method, since the gas-liquid separation member and the filter that removes harmful substances are adjacent to each other, condensed liquid may adhere to the gas-liquid separation member, which may reduce the gas-liquid separation efficiency. .

  Therefore, an object of the present invention is to provide a gas-liquid separator capable of separating gas and liquid more efficiently and a fuel cell using the same.

  In order to achieve the above object, a gas-liquid separator according to the present invention is provided with a casing, a first pipe for introducing a fluid into the casing, and provided in the casing and introduced from the first pipe. A gas-liquid separation membrane that separates the fluid into gas and liquid; a second pipe that discharges the liquid separated by the gas-liquid separation membrane to the outside of the housing; and the gas-liquid separation provided in the housing. A case surrounding the film and a heating element provided in the housing are provided.

  In order to achieve the above object, a fuel cell according to the present invention includes a tank that stores liquid fuel, an anode and a cathode, and an electromotive unit that performs a chemical reaction between the liquid fuel and oxygen to generate power. A pipe through which the discharged fluid discharged from the electric part flows to the tank; and a gas-liquid separator provided on the pipe. The gas-liquid separator introduces a fluid into the casing and the casing. A first pipe, a gas-liquid separation membrane provided in the casing and separating the fluid introduced from the first pipe into a gas and a liquid; and the liquid separated by the gas-liquid separation film. A second pipe for discharging outside the body, a case provided in the casing and surrounding the gas-liquid separation membrane, and a heating element provided in the casing are provided.

  ADVANTAGE OF THE INVENTION According to this invention, the gas-liquid separator which can isolate | separate gas and liquid more efficiently and a fuel cell using the same can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external perspective view showing a fuel cell device according to the present invention. FIG. 2 is an external perspective view showing a state in which the fuel cell device is connected to a notebook computer.

  The fuel cell 1 is used as an external power source of the notebook computer 10, for example. This fuel cell 1 is a direct methanol fuel cell (DMFC: Direct Methanol Fuel Cell). Electric power is generated by using a premixed liquid in which methanol and water are mixed as a fuel and chemically reacting the premixed liquid with oxygen in the air and an electrolyte membrane. This DMFC is easier to handle than a fuel cell using hydrogen as a fuel, and the entire apparatus can be reduced in size.

  The fuel cell 1 has a main body 11 formed in a substantially rectangular parallelepiped and a mounting portion 12 extending flat along the bottom of the main body 11. A large number of ventilation holes 11 a are formed in the wall portion of the main body 11. A power generation unit, which will be described later, is housed inside the main body 11. A part of the main body 11 is formed to be removable as a cover 11b. A fuel tank described later is placed in a portion of the main body 11 from which the cover 11b is removed.

  The placement unit 12 is formed so as to be dockable with the rear part of the notebook computer 10. A control unit, which will be described later, is provided inside the mounting unit 12. The control unit controls the operation of the power generation unit. On the upper surface of the mounting portion 12, a lock mechanism 13 for connecting the notebook computer 10 and a connector 14 for supplying power from the fuel cell 1 to the notebook computer 10 are provided.

  The lock mechanisms 13 are arranged at three places on the placement portion 12 and each include a positioning protrusion 13a and a hook 13b. An engagement hole connected to the lock mechanism 13 and a socket connected to the connector 14 are provided on the bottom surface of the rear portion of the notebook computer 10.

  When the notebook computer 10 is pressed against the placement unit 12, the lock mechanism 13 is inserted into the engagement hole of the notebook computer 10. The notebook computer 10 is held on the placement unit 12 by the hook 13b. As a result, the socket of the notebook computer 10 is electrically connected to the connector 14. In this state, when the switch provided in the main body 11 is turned on, the fuel cell 1 starts power generation.

  The placement unit 12 further includes an eject button 15. When the eject button 15 is pressed, the hook 13b of the lock mechanism 13 is released, and the notebook computer 10 can be detached from the fuel cell 1.

  FIG. 3 is a system diagram of a fuel cell power generation system. FIG. 4 is a diagram schematically showing the cell structure of the power generation unit. The fuel cell 1 includes a power generation unit 20 and a control unit 21 that controls the operation of the fuel cell 1. In addition to controlling the power generation unit 20, the control unit 21 has a function as a communication control unit that communicates with the notebook computer 10. The power generation unit 20 is provided in the main body 11, and the control unit 21 is provided in the placement unit 12.

  The power generation unit 20 includes a stack 22 serving as a center for generating power, and a fuel cartridge 23 that stores methanol serving as fuel. The stack 22 functions as a power generation unit that generates power by a chemical reaction. The fuel cartridge 23 is sealed with high-concentration methanol. The fuel cartridge 23 is detachable so that it can be easily replaced when the fuel is consumed.

  The power generation unit 20 includes a liquid channel for flowing fuel and other fluids, and a gas channel for flowing air and other gases. The liquid flow path includes a fuel pump 24 connected to the output portion of the fuel cartridge 23, a mixing tank 25 connected to the output portion of the fuel pump 24 via the piping, and a feed connected to the output portion of the mixing tank 25. A liquid pump 26 is provided. The output part of the liquid feed pump 26 is connected to the anode (fuel electrode) 27 of the stack 22 via a pipe 91. The pipe 91 defines a flow path for sending an aqueous methanol solution from the mixing tank 25 to the stack 22.

  An ion filter 28 is provided in the pipe 91 between the liquid feed pump 26 and the stack 22. The output portion of the mixing tank 25 is connected to an anode (fuel electrode) 27 via a liquid feed pump 26 and an ion filter 28. The ion filter 28 is realized by using, for example, a metal ion adsorbing substance, and adsorbs metal ions contained in an aqueous methanol solution sent out from the mixing tank 25 toward the stack 22 via the pipe 91, so that the metal from the aqueous methanol solution is adsorbed. Remove the ions.

  The output part of the anode 27 is connected to the input part of the mixing tank 25 via a pipe 92. A gas-liquid separation structure 29 is provided between the anode 27 and the mixing tank 25 on the pipe 92. The pipe 92 defines a flow path for returning the liquid discharged from the anode 27 of the stack 22, that is, an unreacted aqueous methanol solution that has not been used in the chemical reaction, to the mixing tank 25. In addition, the carbon dioxide generated with the power generation reaction is vaporized by the gas-liquid separator 29. The vaporized carbon dioxide passes through the exhaust filter 60 together with the moist air via the pipe 94a, and is finally exhausted to the outside from the exhaust port 58.

  In order to cool the liquid collected in the mixing tank 25 on the pipe 92, a fin or fan for heat dissipation may be provided as necessary.

  On the other hand, an intake port 50 and an air supply pump 51 are provided in the gas flow path. An air supply pump 51 is connected to a cathode (air electrode) 53 of the stack 22 through a pipe 93 in which an air supply valve 52 is disposed. The condenser 54 is connected to the output part of the cathode 53 via the pipes 94a and 94b. The output portion of the mixing tank 25 is connected to the condenser 54 via a pipe 94a in which the mixing tank valve 59 is disposed. The condenser 54 is connected to an exhaust port 58 via an exhaust valve 57. The condenser 54 and the exhaust valve 57 are connected via pipes 96 and 98, and an exhaust filter 60 is provided between the condenser 54 and the exhaust valve 57.

  The condenser 54 functions as a cathode cooling unit that cools the exhaust fluid (water vapor, water) discharged from the output unit of the cathode 53. The condenser 54 includes fins (not shown) and effectively condenses the water vapor. A cooling fan 55 is disposed opposite to the condenser 54. By the cooling by the condenser 54, the water vapor is solidified, and the temperature of the water discharged from the output part of the cathode 53 is also lowered. Thereby, the temperature of the water flowing from the water recovery tank 56 through the pipe 96 becomes about 45 ° C to 50 ° C.

  As will be described in detail later, carbon dioxide is generated on the anode 27 side of the power generation unit 20 and water (water vapor) is generated on the cathode 53 side in accordance with the power generation reaction. The carbon dioxide generated on the anode 27 side and the methanol solution that has not been subjected to the chemical reaction are separated into gas and liquid by the gas-liquid separation structure 29.

  Next, the power generation mechanism of the power generation unit 20 in the fuel cell 1 will be described along the flow of fuel and air (oxygen). As shown in FIG. 4, first, the high-concentration methanol in the fuel cartridge 23 is supplied to the mixing tank 25 by the fuel pump 24. Inside the mixing tank 25, the high-concentration methanol is mixed with the recovered water, low-concentration methanol (remaining power generation reaction) from the anode 27, etc., and diluted to produce a low-concentration methanol aqueous solution. The concentration of the low-concentration methanol aqueous solution is controlled so as to maintain a high power generation efficiency concentration, for example, 3 to 6%. This concentration control is realized, for example, by the control unit 21 of the fuel cell 1 controlling the amount of high concentration methanol supplied to the mixing tank 25 by the fuel pump 24 based on the detection result of the concentration sensor 62. Alternatively, it can be realized by controlling the amount of water circulating in the mixing tank 25 by the water recovery pump 63 or the like.

  The mixing tank 25 is provided with a liquid amount sensor 64 that detects the amount of the aqueous methanol solution in the mixing tank 25 and a temperature sensor 65 that detects the temperature. The detection results of these sensors are sent to the control unit 21 to generate power. Used for controlling the unit 20 and the like.

  The aqueous methanol solution diluted in the mixing tank 25 is pumped to the stack 22 via the pipe 91 by the liquid feed pump 26 and injected into the anode 27. The aqueous methanol solution from the feed pump 26 is sent to the anode 27 of the stack 22 after the metal ions are removed by the ion filter 28. As shown in FIG. 4, at the anode 27, electrons are generated by the oxidation reaction of methanol. Hydrogen ions (H +) generated by the oxidation reaction pass through the solid polymer electrolyte membrane 70 in the stack 22 and reach the cathode 53.

  Air (oxygen) is taken in from the intake port 50 by an air supply pump 51 that constitutes an air supply unit, pressurized, and then supplied from an air supply valve 52 to a cathode (air electrode) 53 of the stack 22 via a pipe 93. Supplied. At the cathode 53, the reduction reaction of oxygen (O2) proceeds, and water (H2O) is vaporized from electrons (e-) from an external load, hydrogen ions (H +) and oxygen (O2) from the anode 27. Is generated as This water vapor is discharged from the cathode 53 and enters the condenser 54. In the condenser 54, the water vapor is cooled by the cooling fan 55 to become water (liquid), and is temporarily accumulated in the water recovery tank 56. The recovered water is circulated to the mixing tank 25 by the water recovery pump 63 to constitute a circulation system for diluting the high-concentration methanol.

  Carbon dioxide produced by the oxidation reaction performed at the anode 27 is introduced into the gas-liquid separation structure 29 together with the methanol aqueous solution that has not been subjected to the reaction. The carbon dioxide separated by the gas-liquid separation structure 29 passes through the pipe 94 a and joins with the pipe 94 b from the cathode 53 and travels toward the condenser 54. The humid air that remains without being condensed by the condenser 54 is introduced into the pipe 96. Since the methanol component contained in the gas discharged from the stack 22 must be cleaned, detoxified, and released, the exhaust filter 60 is provided on the downstream side of the stack 22. The gas rendered harmless by the exhaust filter 60 is discharged from the exhaust port 58 to the outside of the fuel cell 1. The separated methanol aqueous solution is refluxed to the mixing tank 25 through the pipe 92.

  FIG. 5 is a top view showing the configuration of the gas-liquid separator according to the embodiment of the present invention. FIG. 6 is a perspective view showing the configuration of the gas-liquid separator according to the embodiment of the present invention. The gas-liquid separator 29 includes a housing 100, and a case 101 is provided in the housing 100. A pipe 92 is passed through the casing 100 and the case 101, and a gas-liquid separation membrane 102 is provided in the pipe 92 within the case 101. The gas-liquid separation membrane 102 is made of a material that allows gas to pass through, and is made of a porous polymer material such as polyamide, polysulfone, or polyimide.

  The fluid introduced into the case through the pipe 92 is separated into liquid and gas by the gas-liquid separation membrane 102. The case 101 includes an exhaust pipe 101 a that discharges the gas separated by the gas-liquid separation membrane 102 to the outside of the case 101. The gas discharged from the exhaust pipe 101 a is discharged out of the casing 100 through the exhaust pipe 100 a provided in the casing 100. A pump may be provided on the exhaust pipe 100a so that the gas separated by the gas-liquid separation membrane 102 can be easily discharged out of the housing 100 by the pump.

  The gas-liquid separation membrane 102 separates the liquid and gas in the fluid flowing in the pipe 92 using the pressure difference in the pipe 92 and the pressure in the case 101, and the gas in the pipe 92 is separated from the gas-liquid separation membrane 102. Release outside. When the temperature in the housing 100 or the case 101 decreases, the separation gas may aggregate and liquefy, and the liquefied water may cover the gas-liquid separation membrane 102. If the liquefied water covers the gas-liquid separation membrane 102, the gas permeability is lowered and the efficiency of gas-liquid separation may be reduced. Therefore, it is necessary to prevent liquefaction due to aggregation as much as possible.

  In the present embodiment, the casing 100 is provided with an introduction pipe 103a, and air is introduced into the case 101 via a pump or the like. By introducing air into the case 101, the amount of saturated water vapor in the case 101 increases, and liquefaction due to aggregation is less likely to occur.

  Further, a heating element such as a catalyst can be provided on the inner wall 100 b of the housing 100 and the outer wall 101 b of the case 101. Examples of the material used for the catalyst include metal catalysts represented by platinum, ruthenium, palladium, and nickel. By providing a catalyst that reacts with the gas component discharged from the gas-liquid separation membrane 102 through the exhaust port 101a, the temperature in the case 101 can be raised by the reaction heat generated by the exothermic reaction of the catalyst. By increasing the temperature in the case 101, the amount of saturated water vapor can be increased and water aggregation in the case 101 can be suppressed. In addition to providing a solid catalyst on the inner wall 100b of the casing or the outer wall 101b of the casing 101, a particulate catalyst may be filled in a region surrounded by the casing 100 and the casing 101. In the present embodiment, since the case 101 is positioned so as to be surrounded by the casing 100, the heat generated in the casing 100 is efficiently transferred to the case 101.

  FIG. 7 is a block diagram showing the configuration of the gas-liquid separator 29 according to the embodiment of the present invention. A temperature sensor 120 and a humidity sensor 121 may be provided on the outer wall of the case 101 and the inner wall of the housing 100. The temperature sensor 120, the humidity sensor 121, the first pump 122 and the second pump 123 provided in the gas-liquid separator 29 are connected to the control unit 21 and controlled by the control unit 21. The first pump 122 connected to the exhaust pipe 100a and the second pump 123 connected to the introduction pipe 103 are controlled according to the detection results of the temperature sensor 120 and the humidity sensor 121. By controlling the first pump 122 and the second pump 123, the amount of air discharged from the exhaust pipe 100a or introduced from the introduction pipe 103 is adjusted, and the amount of air in the casing 100 or the case 101 is increased. It is also possible to prevent the humidity gas from staying.

  FIG. 8 is a perspective view showing a configuration of a gas-liquid separator according to another embodiment of the present invention. A water receiver 110 can be provided in the casing 100 of the gas-liquid separator 29. The water receiver 110 is inserted from the insertion port 100 c of the housing 100, and is installed so that the water receiving surface 112 surrounded by the frame 111 is positioned below the opening 101 d provided on the bottom surface 101 c of the case 101. It is desirable to lay a water absorbing material on the water receiving surface 112. By providing the water receiver 110, the water agglomerated in the case 101 is absorbed by the water absorbing material and collected. By providing the water receiver 110, it is possible to prevent moisture from adhering to the gas-liquid separation membrane 102 due to the inclination of the casing 100 or the like.

  As described above, when the present invention is implemented, a gas-liquid separator capable of separating gas and liquid more efficiently and a fuel cell using the same can be provided.

  The present invention is not limited to the above embodiment as long as it does not depart from the gist of the present invention, and various modifications are possible.

1 is an external perspective view showing a fuel cell device according to the present invention. The external appearance perspective view which shows the state which connected the fuel cell apparatus to the notebook computer. The system diagram of the power generation system of a fuel cell. The figure which showed typically the cell structure of the electric power generation part. The top view which shows the structure of the gas-liquid separator which concerns on embodiment of this invention. The perspective view which shows the structure of the gas-liquid separator which concerns on embodiment of this invention. The block diagram which shows the structure of the gas-liquid separator which concerns on embodiment of this invention. The perspective view which shows the structure of the gas-liquid separator which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fuel cell, 10 ... Notebook computer, 11 ... Main body, 11a ... Air hole, 11b ... Cover, 12 ... Mounting part, 13 ... Locking mechanism, 13a ... Projection, 13b ... Hook, 14 ... Connector, 15 ... Eject Button, 20 ... Power generation unit, 21 ... Control unit, 22 ... Stack, 23 ... Fuel cartridge, 24 ... Fuel pump, 25 ... Mixing tank, 26 ... Liquid feed pump, 27 ... Anode, 28 ... Ion filter, 29 ... Gas-liquid Separator 50 ... Inlet port, 51 ... Air supply pump, 52 ... Air supply valve, 53 ... Cathode, 54 ... Condenser, 55 ... Cooling fan, 56 ... Water recovery tank, 57 ... Exhaust valve, 58 ... Exhaust port, 59 ... Mixing tank valve, 60 ... Exhaust filter, 61 ... Temperature sensor, 62 ... Concentration sensor, 63 ... Water recovery pump, 64 ... Liquid quantity sensor, 65 ... Temperature sensor, 70 ... Solid high Child electrolyte membrane, 100 ... housing, 101 ... Case, 102 ... gas-liquid separation membrane, 102 ... Case, 120 ... temperature sensor, 121 ... temperature sensor, 122 ... first pump, 123 ... second pump

Claims (10)

A housing,
A first pipe for introducing a fluid into the housing;
A gas-liquid separation membrane provided in the housing and separating a fluid introduced from the first pipe into a gas and a liquid;
A second pipe for discharging the liquid separated by the gas-liquid separation membrane to the outside of the housing;
A case provided in the housing and surrounding the gas-liquid separation membrane;
A heating element provided in the housing;
A gas-liquid separator comprising:   The gas-liquid separator according to claim 1, wherein the heating element is provided on an inner wall of the casing.   The gas-liquid separator according to claim 1, wherein the heating element is provided on an outer wall of the case.   The gas-liquid separator according to claim 1, wherein a catalyst is provided in a region surrounded by the case and the case in the case. The case has an opening on the bottom;
The gas-liquid separator according to claim 1, further comprising a water absorbing material provided to face the opening. A tank containing liquid fuel;
An electromotive unit having an anode and a cathode, and generating electricity by chemically reacting the liquid fuel and oxygen;
A pipe through which discharged fluid discharged from the electromotive section flows to the tank;
A gas-liquid separator provided on the pipe,
The gas-liquid separator is
A housing,
A first pipe for introducing a fluid into the housing;
A gas-liquid separation membrane provided in the housing and separating a fluid introduced from the first pipe into a gas and a liquid;
A second pipe for discharging the liquid separated by the gas-liquid separation membrane to the outside of the housing;
A case provided in the housing and surrounding the gas-liquid separation membrane;
A heating element provided in the housing;
A fuel cell comprising:   The fuel cell according to claim 6, wherein the heating element is provided on an inner wall of the casing.   The fuel cell according to claim 6, wherein the heating element is provided on an outer wall of the case.   The fuel cell according to claim 6, wherein a catalyst is provided in a region surrounded by the casing and the case in the casing. The case has an opening on the bottom;
The fuel cell according to claim 6, further comprising a water absorbing material provided to face the opening.

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