JP5075360B2 - Fuel cell with cooling device - Google Patents

Description

  The present invention relates to a fuel cell.

Currently, secondary batteries such as lithium ion batteries are mainly used as power sources for portable notebook personal computers (hereinafter referred to as notebook PCs) 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.
In order to perform stable power generation in the DMFC, it is necessary to maintain the stack at a constant temperature of about 70 ° C., for example. In the configuration in which the cooling water is circulated to cool the stack, a large cooling system is required and the stack itself becomes large, which is an obstacle to miniaturization of the fuel cell system. In addition to the method of circulating the cooling water, there is a system that monitors the temperature of the stack and the mixing tank and controls the temperature by a cooling fan.

Patent Document 1 describes a fuel cell in which a cooling fan is disposed between an anode side cooling device and a cathode side cooling device. Cooling with a cooling fan keeps the fuel tank, mixing tank, and stack at appropriate temperatures, and allows the system to be smaller than when cooling with cooling water. The temperature of the stack is controlled by a configuration in which the anode-side cooling device and the cathode-side cooling device are arranged in series in the intake direction of the cooling fan or in a configuration arranged in series in the exhaust direction.
JP 2005-259661 A

  However, in the case of the above-described method, the configuration of the cooling fan itself is not particularly considered, and there is room for improvement in terms of cooling efficiency and miniaturization.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel cell including a cooling device that can improve the cooling capacity and can be further reduced in size.

In order to achieve the above object, a fuel cell according to the present invention includes a fuel tank that stores liquid fuel, an anode through which the liquid fuel flows, and a cathode through which air flows , and the liquid fuel and oxygen in the air An electromotive unit that generates electricity by chemically reacting the fuel, a fuel supply unit that supplies liquid fuel from the fuel tank to the electromotive unit, and a loop formed between the electromotive unit and the fuel supply unit provided, comprising said fuel tank and the fuel flow path for circulating the liquid fuel to and from the anode of the electromotive section, and a cooling equipment for cooling the liquid fuel flowing through the fuel flow path The cooling device includes a main body, an inflow port provided in the main body and allowing the liquid fuel to flow into the main body, an exhaust port provided in the main body for discharging the liquid fuel from the main body, and an inside of the main body Provided in front A flow tube of the flow of liquid fuel, a plurality of cooling fans are disposed adjacent to the body side by side in the width direction of the body, and control means for controlling the plurality of cooling fans, provided around said flow tube And a heat dissipating member .

ADVANTAGE OF THE INVENTION According to this invention, the fuel cell provided with the cooling device which can improve cooling capacity and can be reduced further 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 rectangular parallelepiped and a mounting portion 12 that extends flatly 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, which will be 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. The power generation unit 2 includes a fuel supply unit 30, a premixed liquid circulation unit 40, an electromotive unit 50, an air supply unit 60, a fuel cooling unit 70, a water recovery unit 80, and a concentration sensor 90.

  The fuel supply unit 30 includes a fuel tank 31, a fuel supply path 32, a fuel valve 33, and a fuel pump 34. The premixed liquid circulation unit 40 includes a mixing tank 41, a circulation pump 42, a mixed liquid supply path 43, a mixed liquid recovery path 44, a filter 45, an ion filter 46, and a circulation check valve 47. The electromotive unit 50 is configured by stacking a plurality of cells. Each cell includes an anode (fuel electrode) 51, a cathode (air electrode) 52, and an electrolyte membrane 53 sandwiched between them. The air supply unit 60 includes an air supply pump 61, an intake valve 62, and an intake filter 63. The fuel cooling unit 70 includes a drainage cooler 71, a cooling fan 72, and a premixed liquid cooler 73. The water recovery unit 80 includes a condenser 81, a cooling fan 82, a recovery tank 83, a water supply path 84, and a water recovery pump 85. As the density sensor 90, for example, a sound speed sensor is applied. By measuring the speed of sound in a substance, the density of that substance can be determined. Based on this, the concentration of the premixed solution can be determined from the molecular weight of methanol and water as fuel.

  The fuel tank 31 contains high-concentration methanol as liquid fuel. The fuel tank 31 is configured as a fuel cartridge that can be easily replaced. Therefore, when replacing the fuel tank 31, the cover 11 b provided on the main body 11 is removed and the fuel tank 31 is taken out from the main body 11. The fuel tank 31 is communicated with the mixing tank 41 by a fuel supply path 32. A fuel valve 33 and a fuel pump 34 are provided in the middle of the fuel supply path 32. The fuel valve 33 is an electromagnetic valve, and its operation is controlled by the control unit 3 together with the fuel pump 34.

  The control unit 3 includes a fuel valve 33, a fuel pump 34, a circulation pump 42, an air supply pump 61, an intake valve 62, a cooling fan 72, a cooling fan 82, a water level sensor 83a, a water recovery pump 85, an exhaust valve 88, and a concentration sensor 90. Are connected by a signal line to control them. The control unit 3 controls each fluid in the fuel cell 1 according to the flow rates of the fuel pump 34, the circulation pump 42, the air supply pump 61, and the water recovery pump 85, and the openings of the intake valve 62 and the exhaust valve 88. It constitutes an auxiliary machine that controls the flow.

The mixing tank 41 includes a tank 41a and a lid 41b. The tank 41 a of the mixing tank 41 has a fuel inlet 32 a that communicates with the fuel supply path 32, a liquid mixture outlet 43 a that communicates with the liquid mixture supply path 43, and a liquid mixture flow that communicates with the liquid mixture recovery path 44. An inlet 44a is provided.
The mixed liquid supply path 43 and the mixed liquid recovery path 44 are provided between the mixing tank 41 and the electromotive unit 50 and form a loop for circulating the premixed liquid. The mixed solution supply path 43 sends the premixed solution from the mixing tank 41 to the electromotive unit 50. The mixed solution recovery path 44 passes the premixed solution from the electromotive unit 50 to the mixing tank 41.

  In the mixed liquid supply path 43, a circulation pump 42, a filter 45, an ion filter 46, and a circulation check valve 47 are provided. The filter 45 is disposed between the mixing tank 41 and the circulation pump 42. The ion filter 46 is disposed between the circulation pump 42 and the circulation check valve 47. The circulation pump 42 sends the premixed solution from the mixing tank 41 to the electromotive unit 50.

  A drainage cooler 71 is provided in the mixed liquid recovery path 44. The drainage cooler 71 has a plurality of bent heat transfer tubes and a large number of radiating fins attached at right angles around the heat transfer tubes. A cooling fan 72 is attached to the drainage cooler 71. The cooling fan 72 sucks outside air as cooling air from the vent hole 11a of the main body 11, and sends the air in a direction along the radiation fin.

  In the electromotive unit 50, an anode 51 and a cathode 52 are arranged so as to sandwich the electrolyte membrane 53. A mixed liquid supply path 43 and a mixed liquid recovery path 44 are connected to the anode 51, and the premixed liquid flows. An air intake path 64 communicating with the air supply unit 60 and an exhaust path 86 communicating with the condenser 81 are connected to the cathode 52, and air is flowed.

  In the electromotive unit 50, methanol and water in the premixed liquid that flows to the anode 51 react with oxygen in the air that flows to the cathode 52 through the electrolyte membrane 53 to generate power. At this time, carbon dioxide is generated as a reaction product on the anode 51 side. The generated carbon dioxide is discharged to the mixed liquid recovery path 44 together with the surplus premixed liquid. On the cathode 52 side, water is generated in the state of water vapor. The generated water becomes wet air and is discharged to the exhaust path 86.

  The air supply unit 60 sucks in air containing oxygen from the intake filter 63 by the air supply pump 61, and sends it to the cathode 52 through the intake passage 64. An intake valve 62 is provided between the air supply pump 61 and the cathode 52. The exhaust passage 86 communicates with the exhaust port 89 through the condenser 81, the exhaust filter 87 and the exhaust valve 88. The exhaust port 89 opens toward the vent hole 11 a of the main body 11. Moisture in the humid air sent through the exhaust path 86 is condensed in the condenser 81 and collected in the recovery tank 83 disposed at the lower part of the condenser 81. The collection tank 83 communicates with the mixed solution collection path 44 through the water supply path 84. A water level sensor 83a is provided in the recovery tank 83 to detect the water level of the accumulated water. In the middle of the water supply path 84, a water recovery pump 85 and a check valve 85a are provided. The water recovery pump 85 sends the water in the recovery tank 83 to the mixing tank 41.

  The air whose moisture has been recovered to some extent by the condenser 81 is exhausted from the upper part of the condenser 81 and sent to the exhaust filter 87. The exhaust filter 87 is composed of a metal catalyst or the like. The exhaust filter 87 removes harmful substances such as methanol contained in the air exhausted through the exhaust passage 86. A storage portion 87 a is provided immediately below the exhaust filter 87. The reservoir 87a communicates with the water supply path 84 between the water recovery pump 85 and the check valve 85a via the recovery path 87c. The collection path 87c includes a check valve 87b that prevents backflow to the reservoir 87a.

  The concentration sensor 90 is provided in the middle of the bypass passage 91 in order to measure the methanol concentration in the premixed solution. The bypass passage 91 is branched from the mixed solution supply passage 43 between the circulation pump 42 and the ion filter 46, and returns the premixed solution to the mixing tank 41. In order to prevent the detection resolution of the concentration sensor 90 from being reduced by heat, a premixed liquid cooler 73 is provided in the bypass passage 91 upstream of the concentration sensor 90.

  During the operation of the fuel cell 1, the cooling fan 72 and the cooling fan 82 are driven, and outside air is introduced into the main body 11 through the vent holes 11 a formed in the main body 11. The outside air introduced into the main body 11 through the vent hole 11 a and the air in the main body 11 pass through the premixed liquid cooler 73 and the drainage cooler 71 and are sucked into the cooling fan 72. The outside air introduced into the main body 11 by the cooling fan 82 and the air in the main body 11 are sucked into the cooling fan 82 through the condenser 81. In addition, the air exhausted from the cooling fan 72 and the cooling fan 82 passes through the electromotive unit 50 and its surroundings, and is then exhausted to the outside of the main body 11.

  When power generation is performed, the operation of the pump and the valve is controlled by the control unit 3. The control unit 3 drives the fuel pump 34 to supply high-concentration methanol from the fuel tank 31 to the mixing tank 41. The methanol ejected from the fuel inlet 32 a is returned from the recovery tank 83 of the condenser 81 in the middle of the existing premixed liquid, the premixed liquid refluxed from the anode, and the mixed liquid recovery path 44 in the mixing tank 41. Diluted with water. This agitation is performed by the flow of methanol ejected from the fuel inlet 32a and the flow of the premixed liquid ejected from the mixed liquid inlet 44a.

  The premixed liquid added with methanol is supplied to the anode 51 by the circulation pump 42. Air is supplied to the cathode 52 by an air supply pump 61. The supplied methanol and air undergo a chemical reaction at the electrolyte membrane 53 provided between the anode 51 and the cathode 52. As a result, electric power is generated between the anode 51 and the cathode 52. The electric power generated by the electromotive unit 50 is supplied from the control unit 3 to the notebook computer 10 via the connector 14.

  With the power generation reaction, carbon dioxide is generated on the anode 51 side of the electromotive unit 50, and water (water vapor) is generated on the cathode 52 side. The carbon dioxide produced on the anode 51 side and the premixed liquid that has not been subjected to the chemical reaction are sent to the mixed liquid recovery path 44, cooled through the drain cooler 71, and then refluxed to the mixing tank 41.

  The carbon dioxide refluxed to the mixing tank 41 is vaporized in the mixing tank 41. The vaporized carbon dioxide passes through the gas-liquid separation membrane 41k, and joins in the middle of the exhaust passage 86 from the mixing tank 41 through the product gas recovery passage 86a. Carbon dioxide is passed through the exhaust filter 87 together with the humid air. Carbon dioxide and humid air are finally exhausted from the exhaust port 89 to the outside through the exhaust valve 88. Methanol and air splashed into the air through the gas-liquid separation membrane 41k pass through the exhaust filter 87 and are collected and removed by the exhaust filter 87.

  Most of the water generated on the cathode 52 side becomes water vapor and is discharged to the exhaust path 86 together with air. The humid air containing moisture is condensed and separated by the condenser 81. The air passes through the exhaust valve 88 and is exhausted into the main body 11 from the exhaust port 89. The air in the main body 11 is further exhausted to the outside through the vent hole 11a. The water condensed by the condenser 81 is collected in the recovery tank 83 and injected into the mixed liquid recovery path 44 by the water recovery pump 85. The water is sent to the mixing tank 41, mixed with methanol, and then supplied again to the electromotive unit 50 from the mixed solution supply path 43.

  Further, the water that cannot be completely collected by the condenser 81 and is condensed in the exhaust passage 86 on the downstream side of the condenser 81 is stored in a storage portion 87 a provided immediately below the exhaust filter 87. The water stored in the storage part 87 a is joined to the mixed solution recovery path 44 through the water supply path 84.

  The concentration of methanol in the mixing tank 41 is detected by the concentration sensor 90. The control unit 3 operates the water recovery pump 85 according to the detected concentration and adjusts the amount of water supplied from the recovery tank 83 to the mixing tank 41. Thereby, the concentration of methanol in the premixed solution is kept constant. In addition, the amount of water collected through the exhaust path 86, that is, the amount of water vapor condensed is adjusted by controlling the cooling capacity of the condenser 81. The cooling capacity of the condenser 81 is adjusted according to the water level of the recovery tank 83. In the present embodiment, the drive voltage of the second cooling fan 82 is controlled according to the water level detected by the water level sensor 83a. The cooling capacity of the condenser 81 is adjusted by controlling the cooling fan 82 to control the amount of collected water. While the water recovery pump 85 is driven forward by the controller 3, the check valve 85a is opened and the check valve 87b is closed. The water in the recovery tank 83 is sent from the water supply path 84 and the check valve 85 a to the mixing tank 41 through the mixed liquid recovery path 44.

  Further, the control unit 3 drives the water recovery pump 85 in reverse rotation for a predetermined time every fixed operation period. Water collected in the reservoir 87a is collected in the collection tank 83. When the water recovery pump 85 is driven in reverse, the check valve 87b is opened and the check valve 85a is closed. As a result, the water accumulated in the reservoir 87a and the water condensed in the exhaust path 86 downstream from the condenser 81 are collected in the collection tank 83 through the collection path 87c, the check valve 87b, and the water supply path 84. Is done. Thereafter, the recovered water is supplied to the mixing tank 41 and used for dilution of methanol.

  FIG. 4 is an external perspective view showing the structure of the cooling system according to the embodiment of the present invention. FIG. 5 is a top view showing the structure of the cooling fan according to the embodiment of the present invention. The cooling system according to the present invention includes a cooling fan unit 100 and a heat exchanger 120. The cooling fan unit 100 includes, for example, two cooling fans 101. Openings 103 a and 103 b through which air sucked by the fan 102 passes are provided on the upper surface 101 a and the lower surface (not shown) of the cooling fan 101. A discharge port (not shown) for discharging the air sucked in by the fan 102 is provided in the back surface portion 101 c located on the opposite side of the front surface portion 101 b of the cooling fan 101. The air sucked in by the fan 102 is discharged through a discharge port (not shown) in the direction of arrow A shown in FIGS. 4 and 5 to cool the heat exchanger 120.

  The main body 120a of the heat exchanger 120 is provided with a fuel inlet 121 through which liquid fuel flows, a fuel flow pipe 122 through which the liquid fuel flows in, and a fuel outlet 123 through which the liquid fuel is discharged. FIG. 5 shows the inside of the main body 120a of the heat exchanger 120 as seen through. In order to cool the liquid fuel, a fin 124 for absorbing heat and releasing it to the outside of the main body 120 a is provided so as to surround the fuel flow pipe 122. The liquid fuel flows through the fuel flow pipe 122 as shown by an arrow B in FIG. The cooling fan unit 100 is provided on the downstream side with respect to the flow of the liquid fuel. The wind blown from the fan 102 to the heat exchanger 120 takes the heat of the fins 124 on the leeward side, and the temperature rises. When the cooling fan unit 100 is placed on the upstream side of the liquid fuel, the temperature of the cooled liquid fuel rises again while flowing through the fuel flow pipe 122 and is discharged from the fuel discharge port 123. By disposing the cooling fan unit 100 on the downstream side of the liquid fuel and cooling it immediately before discharging from the fuel discharge port 123, the liquid fuel can be efficiently cooled.

  Compared to the case where one cooling fan having the same width as the heat exchanger width L is provided for one heat exchanger 120, the cooling fan 101 having a width L / 2 that is half the width L of the heat exchanger. When two are provided, the area of the cooling fan unit 101 can be reduced. If the cross-sectional area of the vent is the same, basically the same cooling capacity can be exhibited. Since the cooling fan 101 is arranged so that air is sucked through the openings 103a and 103b and the inlets of the cooling fan 101 do not interfere with each other, the cooling fan 101 can be efficiently cooled. Further, more efficient cooling is possible by individually controlling the cooling fans 101 as will be described later. The cooling system including the cooling fan 101 and the heat exchanger 120 can be used for the condenser 81 in addition to the fuel cooling unit 70. In the electromotive unit 50, the cell stack unit configured by stacking the anode 51 and the cathode 52 may be provided with a vent hole, and the cell stack unit may be directly cooled by the cooling fan unit 100.

  When this embodiment is implemented, it is possible to provide a fuel cell equipped with a cooling unit capable of improving the cooling capacity and further reducing the size.

  FIG. 6 is a perspective view showing an arrangement of a cooling fan and a heat exchanger according to another embodiment of the present invention. The cooling fan unit 100 has the same configuration as that shown in FIGS. 4 and 5 and will not be described in detail. The main body 130a of the heat exchanger 130 is provided with a fuel inlet 131 through which liquid fuel flows, a fuel flow pipe 132 through which the liquid fuel flows in, and a fuel outlet 133 through which the liquid fuel is discharged. As shown in a perspective view of the inside of the main body 130a of the heat exchanger 130, fins 134 for absorbing heat and releasing it to the outside of the main body 130a surround the fuel flow pipe 132 in order to cool the liquid fuel. Is provided. The fuel flow pipe 132 may be installed perpendicular to the ground plane. In this case, it is desirable that the liquid fuel flow from the lower surface to the upper surface of the heat exchanger 130 so that the gas such as carbon dioxide generated by the chemical reaction does not accumulate in the heat exchanger 130. The liquid fuel flows through the fuel flow pipe 132 as shown by an arrow C in FIG. Cooling efficiency can be improved by installing the cooling fan unit 100 so that the flow of fuel in the fuel flow pipe 132 and the wind from the cooling fan 101 are orthogonal to each other.

  FIG. 7 is a flowchart showing a cooling operation according to the embodiment of the present invention. FIG. 8 is a flowchart showing the rotation speed control operation of the fan according to the embodiment of the present invention. The symbols shown in FIGS. 7 and 8 indicate the temperature when the cooling fan is turned on, Ton, the temperature when the cooling fan is turned off, Ttrg, the target temperature to be controlled, Ttrg, the temperature at the previous measurement To, the current , Tnow, the current cooling fan speed is Nnow, the minimum cooling fan speed is Nmin, and the maximum cooling fan speed is Nmax.

  The temperature of the heat exchanger or the stack is controlled by the two cooling fans 101. Hereinafter, the term “temperature” refers to the temperature of an object to be cooled, such as a heat exchanger or a stack, unless otherwise specified. First, the temperature is measured to determine whether the current temperature is equal to the target temperature (step 1). When the current temperature is equal to the target temperature (Yes in Step 1), control is performed to maintain the current temperature (Step 2), and the temperature at that time is recorded (Step 3). When the current temperature deviates from the target temperature (No in Step 1), it is determined whether or not the cooling fan 101 is being driven (Step 4). When the cooling fan 101 is being driven (Yes in Step 4), if the current temperature is equal to or lower than the cooling fan stop temperature (Yes in Step 5), the cooling fan 101 is turned off (Step 6). Processing when the current temperature is higher than the cooling fan stop temperature will be described later.

  When the current temperature deviates from the target temperature (No in Step 1) and the cooling fan 101 is not driven (No in Step 4), it is determined whether or not the current temperature is equal to or higher than the cooling fan drive temperature ( Step 7). When the current temperature is equal to or higher than the cooling fan driving temperature (Yes in Step 7), the cooling fan 101 is driven (Step 8). The fan rotation speed at this time is set to the minimum rotation speed (step 9). When the current temperature is lower than the cooling fan driving temperature (No in step 7), the cooling fan 101 is not driven and the state is maintained (step 10). When the cooling fan 101 is turned off (step 6), when the cooling fan 101 is driven and set to the minimum rotational speed (step 9), when the cooling fan 101 is not driven and the state is maintained (step 10), In this case, the temperature is recorded when the process is completed (step 3).

  When the cooling fan 101 is driven (Yes in Step 4) and the current temperature is higher than the cooling fan stop temperature (No in Step 5), the current temperature is compared with the target temperature (Step 11). When the current temperature is higher than the target temperature (Yes in step 11), the current temperature is compared with the previously recorded temperature (step 12). When the current temperature is equal to or lower than the previously recorded temperature (Yes in Step 12), the current state is maintained (Step 13) and the temperature at that time is recorded (Step 14). When the current temperature is higher than the previously recorded temperature (Yes in Step 12), it is determined whether or not the rotational speed of the cooling fan 101 is the maximum rotational speed (Step 15). When the rotation speed of the cooling fan 101 is the maximum rotation speed (Yes in step 15), the current state is maintained (step 16). When the rotation speed of the cooling fan 101 is not the maximum rotation speed (No in step 15), the rotation speed of the cooling fan 101 is set to the minimum rotation speed (step 17).

  When the current temperature is lower than the target temperature (No in step 11), it is determined whether or not the current temperature is higher than the previously recorded temperature (step 18). When the current temperature is higher than the previously recorded temperature (Yes in Step 18), the current state is maintained (Step 19). When the current temperature is equal to or lower than the previously recorded temperature (No in Step 18), it is determined whether or not the rotational speed of the cooling fan 101 is the minimum rotational speed (Step 20). When the rotation speed of the cooling fan 101 is the minimum rotation speed (Yes in step 20), the current state is maintained (step 21). When the rotation speed of the cooling fan 101 is not the minimum rotation speed (No in step 20), the rotation speed of the cooling fan 101 is set to the minimum rotation speed (step 22).

  When maintaining the rotation speed of the cooling fan 101 at the maximum rotation speed (step 16), when setting the rotation speed of the cooling fan 101 to the minimum rotation speed (step 17), the current temperature is larger than the previously recorded temperature. When maintaining this state (step 19), the rotation speed of the cooling fan 101 is maintained at the minimum rotation speed (step 21). When the number of rotations of the cooling fan 101 is set to the minimum number of rotations (step 22), the temperature is recorded when the process is finished in any case (step 14).

  FIG. 9 is a diagram showing temperature fluctuations when the cooling operation according to the embodiment of the present invention is performed. If it is possible to control the two cooling fans 101 individually, the temperature can be controlled in accordance with the fluctuation of the environmental temperature by individually setting the stop temperatures of the two cooling fans 101. Here, the symbols in the figure indicate that the temperature when turning off one of the two cooling fans 101 (first cooling fan) is Toff1, and the other cooling fan (second cooling fan) is off. Toff2 is the temperature at the time of control, Ttrg is the target temperature to be controlled, and it is the environmental temperature at time t = 0, and the temperature at which the two cooling fans 101 can maintain the operating temperature at Ttrg at the fan rotation speed No. , The ambient temperature at time t = t1, and the temperature at which the operating temperature can be maintained at Ttrg by setting one of the two cooling fans 101 to the minimum rotational speed is T1, and the rotational speed of the cooling fan at time t = 0 Is No, and the minimum rotational speed of the cooling fan is Nmin.

  Hereinafter, an example of the control of the fan rotation speed according to the change of the environmental temperature will be described. In the section from time t = 0 to t = t1, the rotational speeds of the first cooling fan and the second cooling fan are both No, and the operating temperature is maintained at Ttrg at the environmental temperature T0. As the environmental temperature decreases at time t = t1, the operating temperature also decreases. As a situation where the environmental temperature decreases, for example, when moving from indoors to outdoors. When the operating temperature decreases, the first fan rotation speed and the second fan rotation speed are decreased. Due to the effect of lowering the first fan rotation speed and the second fan rotation speed, the operating temperature becomes Toff2 at time t = t2. When the operating temperature reaches Toff2, the second cooling fan is turned off. At this time, the first cooling fan is controlled to the minimum rotation speed Nmin. Since the second cooling fan is turned off and the rotation speed of the first cooling fan is minimized, the operating temperature starts to increase after t = t2. When the operating temperature rises and returns to the target temperature Ttrg at t = t3, it returns to the stable operation state.

  When there is one cooling 101 fan, the operating temperature fluctuates in an unstable manner as a result of frequently turning on / off the fan according to changes in the environmental temperature. By using a plurality of, for example, two cooling fans 101, more stable temperature control is possible as compared to the case where there is only one cooling fan 101. Moreover, the cooling fan unit 100 can be reduced in size.

  When this embodiment is implemented, it is possible to provide a fuel cell having a cooling device capable of improving the cooling capacity and further reducing the size.

  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. 1 is an external perspective view showing a structure of a cooling fan according to an embodiment of the present invention. The top view which shows the structure of the cooling fan which concerns on embodiment of this invention. The perspective view which shows arrangement | positioning with the cooling fan and heat exchanger which concern on other embodiment of this invention. The flowchart which shows the cooling operation | movement which concerns on embodiment of this invention. The flowchart which shows the rotation speed control operation | movement of the fan which concerns on embodiment of this invention. The figure which shows the temperature fluctuation at the time of performing the cooling operation which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fuel cell, 2 ... Electric power generation part, 3 ... Control part, 10 ... Notebook computer, 11 ... Main body, 11a ... Air hole, 11b ... Cover, 12 ... Mounting part, 13 ... Locking mechanism, 14 ... Connector, 15 DESCRIPTION OF SYMBOLS ... Eject button, 31 ... Fuel tank, 32 ... Fuel supply path, 32a ... Fuel inlet, 33 ... Fuel valve, 34 ... Fuel pump, 41 ... Mixing tank, 41a ... Tank, 41b ... Lid, 43 ... Mixture supply path 43a ... mixture outlet, 44 ... mixture recovery path, 44a ... mixture inlet, 51 ... anode, 52 ... cathode, 53 ... electrolyte membrane, 63 ... intake filter, 64 ... intake path, 71 ... drainage cooling 72, first cooling fan, 73 ... premixed liquid cooler, 81 ... condenser, 82 ... second cooling fan, 83 ... recovery tank, 84 ... water recovery path, 86 ... exhaust path, 87 ... Exhaust filter, 90 ... concentration sensor, 5 ... base manifold, 100 ... cooling fan unit, 101 ... cooling fan, 120 ... heat exchanger, 121: fuel inlet, 122 ... fuel flow pipe, 123 ... fuel outlet, 124 ... fin

Claims (2)

A fuel tank containing liquid fuel;
An electromotive unit that has an anode through which the liquid fuel flows and a cathode through which air flows, and that generates electricity by causing a chemical reaction between the liquid fuel and oxygen in the air ;
A fuel supply unit for supplying liquid fuel from the fuel tank to the electromotive unit;
A fuel flow path provided so as to form a loop between the electromotive unit and the fuel supply unit, and for circulating the liquid fuel between the fuel tank and the anode of the electromotive unit ;
And a cooling equipment for cooling the liquid fuel flowing through the fuel channel,
The cooling device is
The body,
An inflow port provided in the main body for allowing the liquid fuel to flow into the main body;
An outlet provided in the main body for discharging the liquid fuel from the main body;
A flow pipe provided inside the main body and through which the liquid fuel flows;
A plurality of cooling fans arranged adjacent to the main body in the width direction of the main body,
And control means for controlling the plurality of cooling fans,
A fuel cell, comprising: a heat dissipating member provided around the flow tube . A fuel tank containing liquid fuel;
An electromotive unit that has an anode through which the liquid fuel flows and a cathode through which air flows, and that generates electricity by causing a chemical reaction between the liquid fuel and oxygen in the air ;
A fuel supply unit for supplying liquid fuel from the fuel tank to the electromotive unit;
A fuel flow path provided so as to form a loop between the electromotive unit and the fuel supply unit, and for circulating the liquid fuel between the fuel tank and the anode of the electromotive unit ;
And a cooling equipment for cooling the liquid fuel flowing through the fuel channel,
The cooling device is
The body,
An inflow port provided in the main body for allowing the liquid fuel to flow into the main body;
An outlet provided in the main body for discharging the liquid fuel from the main body;
A flow pipe provided inside the main body and through which the liquid fuel flows;
A plurality of cooling fans arranged in the width direction of the main body and adjacent to the main body and having exhaust ports provided in a positional relationship orthogonal to the flow tube ;
Fuel cell; and a control means for controlling the plurality of cooling fans.

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