JP2004146274A - Fuel cell power generation method and small fuel cell system device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell power generation method in which, while improving the supply form of fuel consumed for power generation and evasion of deterioration of generation capability by carbon dioxide gas, large sizing of the system unit brought about in order to measure precisely the concentration of the liquid fuel is avoided, and a small fuel cell system unit. <P>SOLUTION: The system device comprises a concentration sensor 21 for measuring concentration of the circulating liquid fuel by AC impedance, a micro gear pump 19 for circulating the liquid fuel, a microsyringe 14 for injecting the liquid fuel from the outside into the circulating liquid fuel based on the measured concentration of the concentration sensor 21, and a vent filter for exhausting the unnecessary gas such as carbon dioxide generated by keeping the circulating liquid fuel always in a pressurized state more than atmospheric pressure. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel cell power generation method using a liquid fuel and a small fuel cell system device directly used for implementing the invention of the method.
[0002]
[Prior art]
A conventional fuel cell system using a liquid fuel will be described.
FIG. 12 is a configuration diagram of a direct methanol fuel cell system using methanol as a fuel as an example.
[0003]
The direct methanol fuel cell system device α includes a fuel cell 4 including a solid polymer electrolyte membrane 1, an air electrode 2, and a fuel electrode 3, an air supply unit 6 including a blower 5 for feeding air to the air electrode 2, A fuel supply means 7 for supplying fuel to the pole 3 is connected to a pipe.
[0004]
The fuel supply means 7 is composed of a methanol tank 8 storing high-concentration methanol and a water tank 9 containing water for diluting the methanol aqueous solution, and a liquid feed pump for circulating the methanol aqueous solution as a fuel. 10 and a gas-liquid separator 11 that discharges carbon dioxide generated at the fuel electrode 3 to the outside are connected to the circulation pipe in a way.
[0005]
Then, since methanol and water in the methanol aqueous solution are consumed by the power generation, the high-concentration methanol from the methanol tank 8 and the water from the water tank 9 are converted into the methanol aqueous solution in the process of circulating the methanol aqueous solution by the liquid sending pump 10. By supplying and adjusting the concentration of the aqueous methanol solution and keeping the concentration of the aqueous methanol solution constant, a stable output can be obtained from the fuel cell 4.
[0006]
Since water vapor is generated at the air electrode 2 by performing power generation, a condenser 12 for liquefying the water vapor is provided at the outlet side of the air electrode 2, and water obtained by the condenser 12 is supplied to a water tank 9. By supplying the water, the water can be reused.
[0007]
In addition to the above-described conventional techniques, there are, for example, the following Non-Patent Documents 1 and 2.
[Non-patent document 1]
NIKKEI MICRODEVICES April 2002 Issue p.51
[Non-patent document 2]
Nikkei Mechanical D & M 2002.2.2. No.569 Page 20
[0008]
[Problems to be solved by the invention]
However, the conventional fuel cell system device α has a problem that the size and weight of the system device cannot be reduced. The main causes are as follows.
[0009]
First, although the concentration of the aqueous methanol solution can be measured accurately using a liquid chromatograph, the size of the system is large, and as a result, it is difficult to reduce the size and weight of the system device. In this regard, it is possible to calculate the amount of methanol consumed to obtain the concentration of the aqueous methanol solution by integrating the output of the fuel cell, but unreacted methanol causes the solid polymer electrolyte membrane 1 to move to the fuel electrode 3 side. Therefore, it is difficult to accurately calculate the concentration because a so-called methanol crossover phenomenon that is transmitted to the air electrode 2 side from the air occurs.
[0010]
Second, in order to accurately adjust the concentration of methanol, it is necessary to inject a high-concentration methanol and water into a methanol aqueous solution in a required amount, respectively, by using a micro syringe pump. Although possible, the size of the device was large, and as a result, it was difficult to reduce the size and weight of the system device.
[0011]
Thirdly, a liquid pump is required to circulate the aqueous methanol solution. However, diaphragm-type liquid pumps that are widely used at present have many components such as eccentric cams, connecting rods, and diaphragms, and the structure is large. Because of the complexity, it has been difficult to reduce the size and weight of the system device.
[0012]
Fourth, the carbon dioxide generated at the fuel electrode 3 by the electrode reaction is present as bubbles in the aqueous methanol solution, and the bubbles stay in the vicinity of the fuel electrode 3 so that the supply of methanol can be smoothly performed. The gas-liquid separator 11, which is usually used for removing gas from a liquid, is large in size. Therefore, it has been difficult to reduce the size and weight of the system device.
[0013]
Therefore, the present invention has been made in view of such a drawback, and the main objects to be solved by the present invention are as follows.
[0014]
A first object of the present invention is to provide a fuel cell power generation method and a small fuel cell system device in which the supply form of fuel consumed for power generation is improved.
[0015]
A second object of the present invention is to provide a fuel cell power generation method and a small-sized fuel cell system device in which the avoidance of a decrease in power generation capacity due to carbon dioxide gas is improved.
[0016]
A third object of the present invention is to provide a fuel cell power generation method and a small-sized fuel cell system device, which avoids an increase in the size of a system device required for accurately measuring the concentration of liquid fuel.
[0017]
Other objects of the present invention will become apparent from the description of the specification, drawings, and particularly from the claims.
[0018]
[Means for Solving the Problems]
In order to solve the above problems, the method of the present invention comprises: (1) a characteristic configuration method of measuring the concentration of liquid fuel by an AC impedance; (2) a micro syringe provided with a piston operated by a stepping motor for fuel injection; Or 3) a characteristic configuration method of circulating liquid fuel using a micro gear pump composed of a pair of gears created by micro machining technology, and 4) a characteristic configuration method of liquid fuel. A characteristic configuration method is adopted in which the pressure is constantly increased to the atmospheric pressure or higher and unnecessary gas generated in the fuel cell is removed by a vent filter.
[0019]
In order to solve the above problems, the system device of the present invention is a concentration sensor that measures the concentration of the liquid fuel by AC impedance, a micro gear pump that circulates the liquid fuel, a micro syringe or an ink jet that injects the liquid fuel, and the fuel is always at or above atmospheric pressure Under the pressurized condition, a characteristic filter is provided which includes a vent filter for discharging unnecessary gas such as carbon dioxide generated.
[0020]
More specifically, in solving the problem, the present invention achieves the above object by adopting the following novel characteristic configuration method or means.
[0021]
The first feature of the method of the present invention is to measure a fuel concentration by measuring an AC impedance using a metal probe installed in a fuel flow path connected to a fuel cell, and to measure the fuel concentration. The present invention resides in adopting a configuration of a fuel cell power generation method for estimating the amount of fuel to be injected.
[0022]
According to a second feature of the method of the present invention, the fuel in the first feature of the present method is injected into the fuel flow path by a micro syringe having a piston operated by a stepping motor. The present invention is to adopt a configuration of a fuel cell power generation method.
[0023]
A third feature of the method of the present invention is the configuration of a fuel cell power generation method, wherein the fuel in the first feature of the above-described method of the present invention is injected into the fuel flow path by the inkjet at the estimated amount. In hiring.
[0024]
A fourth feature of the method of the present invention is that a liquid fuel in a fuel flow path connected to a fuel cell is circulated by a micro gear pump composed of a pair of gears made by micro machining technology. It consists in adopting the configuration of the battery power generation method.
[0025]
A fifth feature of the method of the present invention is that the fuel in the fuel flow path connected to the fuel cell is constantly pressurized to the atmospheric pressure or higher, and the fuel cell is pressurized by a vent filter provided in the fuel flow path. An object of the present invention is to employ a configuration of a fuel cell power generation method for discharging unnecessary gas generated in the fuel cell.
[0026]
A first feature of the system device of the present invention is that a fuel cell, air supply means for feeding air to the air electrode of the fuel cell, and fuel supply for supplying fuel to the fuel electrode of the fuel cell Means, and a fuel flow path which connects the fuel supply means and the fuel electrode and serves as a fuel circulation path, wherein a metal probe inserted into the fuel flow path is used as a sensor to measure the AC impedance. Another object of the present invention is to provide a small fuel cell system having a concentration sensor for detecting the concentration of liquid fuel.
[0027]
A second feature of the system device of the present invention is that a fuel cell, air supply means for feeding air to the air electrode of the fuel cell, and fuel supply for supplying fuel to the fuel electrode of the fuel cell And a fuel passage connecting the fuel supply means and the fuel electrode and serving as a fuel circulation path, wherein the fuel supply means seals the fuel with a liquid cartridge and the liquid cartridge. Fuel cell comprising a micro-syringe for charging the liquid cartridge and an adjusting means for adjusting the amount of fuel injected into the fuel flow path by pressurizing the liquid cartridge via a piston operated by a stepping motor. The configuration of the system device is adopted.
[0028]
A third feature of the system device of the present invention is that a fuel cell, air supply means for feeding air to the air electrode of the fuel cell, and fuel supply for supplying fuel to the fuel electrode of the fuel cell And a fuel passage connecting the fuel supply means and the fuel electrode and serving as a fuel circulation path, wherein the fuel supply means seals the fuel with a liquid cartridge and the liquid cartridge. And a control means for adjusting the injection amount of fuel into the fuel flow path by ink jet.
[0029]
A fourth feature of the system device of the present invention is that a fuel cell, air supply means for feeding air to the air electrode of the fuel cell, and fuel supply for supplying fuel to the fuel electrode of the fuel cell And a fuel flow path that connects the fuel supply means and the fuel electrode and serves as a fuel circulation path, wherein the fuel flow path is formed from a pair of gears created by micromachining technology. Another aspect of the present invention resides in the adoption of a configuration of a small fuel cell system device including a micro gear pump.
[0030]
A fifth feature of the system device of the present invention is that the fuel passage in the second feature of the system device of the present invention has a porous structure in which unnecessary gas generated inside is pressurized and discharged by the adjusting means. Another object of the present invention is to adopt a configuration of a small fuel cell system device having a vent filter interposed therebetween.
[0031]
A sixth feature of the system device of the present invention is that the micro syringe in the second, third or fifth feature of the above-described system device of the present invention is a puncture supply that is triggered by opening the liquid cartridge when the liquid cartridge is loaded. The present invention resides in adoption of a configuration of a small fuel cell system device having a nozzle.
[0032]
A seventh feature of the system device of the present invention is that the liquid cartridge according to the sixth feature of the above-described system device of the present invention is such that when the liquid cartridge is loaded into the micro syringe, a portion that becomes a through hole by the breakage supply nozzle becomes thin. The configuration of the fuel cell system device is adopted.
[0033]
An eighth feature of the system device of the present invention is that the liquid cartridge according to the sixth feature of the above-described system device of the present invention has a hole penetrated by the puncture supply nozzle when the liquid cartridge is loaded into the micro syringe, and increases the internal pressure. Another object of the present invention is to adopt a configuration of a small fuel cell system device having a built-in small ball that seals the hole from the inside by increasing the pressure above the atmospheric pressure.
[0034]
A ninth feature of the system device of the present invention is that the liquid cartridge according to the second, third, fifth, sixth, seventh or eighth feature of the system device of the present invention is arranged such that the liquid cartridge is mounted in the micro syringe in the loading direction. On the other hand, a small fuel cell system device having a bellows structure that can expand and contract is used.
[0035]
A tenth feature of the system device of the present invention is that the liquid cartridge according to the second, third, fifth, sixth, seventh, eighth, or ninth feature of the above-described system device of the present invention has a circular cross section. , An ellipse, an n-sided polygon (n ≧ 3), or an n-sided polygon with rounded corners (n ≧ 3).
[0036]
By employing such a configuration, the following items can be realized.
First, by applying an AC voltage between two probes inserted into the circulating liquid fuel and measuring the AC impedance, the concentration can be accurately measured with a simple system device.
[0037]
Second, by precisely controlling the rotation angle of the rotation shaft of the stepping motor and accurately controlling the amount of movement of the piston in the micro syringe that moves in proportion to the rotation angle of the rotation shaft of the stepping motor, high concentration is achieved. Liquid fuel injection amount can be accurately controlled. In connection with this, the circulating liquid fuel can be pressurized by maintaining the rotation angle of the rotating shaft by the stepping motor.
[0038]
Third, since a minute amount of liquid fuel is injected as droplets by ink jet, it is possible to accurately adjust the concentration of the liquid fuel.
[0039]
Fourth, by circulating the liquid fuel by a micro gear pump composed of a pair of spaced-apart meshing gears made by micro machining technology using a silicon process, the size and weight of the liquid feed pump can be reduced.
[0040]
Fifth, by constantly pressurizing the circulating liquid fuel to a pressure higher than the atmospheric pressure, the gas in the liquid fuel can be easily removed by a vent filter having a continuous porous structure.
[0041]
Sixth, by loading the liquid cartridge into the microsyringe, the seal of the liquid cartridge is broken by the rupture supply nozzle that penetrates the blind end of the microsyringe and communicates with the fuel flow path, and the liquid in the liquid cartridge ( Fuel) can be used.
[0042]
Seventh, the bottom surface of the liquid cartridge has a solid structure compared to the side surface and the other bottom surface, so that the liquid cartridge normally has good mechanical strength and does not leak, and only when necessary ( Breaking the pad portion (such as by a micro-syringe break-through nozzle) allows the liquid in the liquid cartridge to be released.
[0043]
Eighth, the holes provided in the liquid cartridge loaded in the microsyringe are made into small spheres (small diameters larger than the holes) by the pressure higher than the internal atmospheric pressure so as to correspond to the breakage supply nozzle provided in the microsyringe. By enclosing the microspheres with a microsphere, it is possible to apply pressure to the microspheres via a breakage supply nozzle, if necessary, as long as it is contained in a micro-syringe without leaking the liquid inside. Therefore, the small ball is removed from the hole, and the liquid in the liquid cartridge can be discharged into the breakage supply nozzle.
[0044]
Ninth, it is possible to discharge the liquid cartridge having the bellows structure to the outside while controlling the amount of liquid in the liquid cartridge by applying pressure from the outside in the expansion and contraction direction. In this connection, when pressure is applied to the liquid cartridge, the liquid cartridge does not bend inside the micro syringe because the liquid cartridge has a bellows structure, and the liquid in the liquid cartridge can be used up.
[0045]
Tenth, since the cross section of the liquid cartridge can be freely selected, the degree of freedom with respect to the shape of the micro syringe is increased, and the system design is facilitated.
[0046]
BEST MODE FOR CARRYING OUT THE INVENTION
Here, embodiments of the present invention will be described with reference to the drawings.
[0047]
(System device example 1)
FIG. 1 is a schematic diagram of a configuration of a small fuel cell system device according to an embodiment of the present invention. It is assumed that the fuel is an aqueous methanol solution.
The small fuel cell system β is composed of a fuel cell 4 composed of a solid polymer electrolyte membrane 1, an air electrode 2 and a fuel electrode 3, an air supply means 6 composed of a blower 5 for feeding air to the air electrode 2, And a fuel supply means 13 for supplying fuel to the fuel cell.
[0048]
The fuel supply means 13 includes a micro syringe 14, a high-concentration methanol cartridge 15, a water cartridge 16, a piston 17 with a rack rod 17a, and a stepping motor 18 with a pinion 18a. A micro gear pump 19 for circulating a methanol aqueous solution as a fuel, a vent filter 20 for releasing carbon dioxide generated in the fuel electrode 3 to the outside, a methanol aqueous solution concentration sensor 21 and a methanol aqueous solution pressure sensor 22 are connected and connected. ing.
[0049]
Since the methanol and water in the aqueous methanol solution are consumed by the power generation, in the process of circulating the aqueous methanol solution by the micro gear pump 19, the high-concentration methanol from the high-concentration methanol cartridge 15 and the water from the water cartridge 16 are combined with the aqueous methanol solution. To adjust the concentration of methanol.
[0050]
Further, the piston 17 is moved forward through the engagement of the pinion 18a rotated by the stepping motor 18 and the rack rod 17a, and high-concentration methanol and water are injected into the aqueous methanol solution from the breakage supply nozzle 26 while pressurizing the methanol, respectively. The aqueous solution is pressurized (at atmospheric pressure or higher), and bubbles (unnecessary gas) of carbon dioxide present in the methanol aqueous solution can be discharged from the vent filter (preferably a continuous and porous filter) 20 to the outside. It becomes.
[0051]
[Details of density sensor]
FIG. 2 is a cross-sectional view of a methanol flow channel provided with a metal probe for measuring the AC impedance of a methanol aqueous solution for the concentration sensor of FIG.
FIG. 3 is a diagram showing the relationship between the methanol concentration and the impedance, using the frequency (10, 100, 1000 Hz) of the AC voltage applied between the two metal probes as a parameter.
[0052]
As shown in FIG. 2, the concentration sensor 21 has a structure in which two metal probes 24 are inserted inside a methanol flow path 23 through which a methanol aqueous solution flows.
Then, as shown in FIG. 3, since there is a good linear relationship between the methanol concentration and the impedance, both of them (the linear relationship is not indispensable, and a one-to-one correspondence is sufficient). By measuring the relationship between the methanol concentration and impedance in the system and formulating the correlation between the two, it becomes possible to accurately measure the methanol concentration with a simple device.
[0053]
[Details of micro gear pump]
FIG. 4 is a sectional view of the micro gear pump of FIG.
In the micro gear pump 19, a pair of micro gears 25 are separately meshed inside. The microgear 25 can be reduced in size and weight by being made by micromachining technology based on a silicon process, and is also excellent in maintainability because the structure of the pump itself is simple. In FIG. 4, the methanol aqueous solution circulates from top to bottom (in the direction of the arrow), and the left micro gear 25 rotates clockwise and the right micro gear 25 rotates counterclockwise. It is a figure to do.
[0054]
[Details of high concentration methanol cartridge and water cartridge]
FIG. 5 shows an adjusting means for adjusting the injection amount of fuel into the methanol flow path by pressurizing the liquid cartridge via a piston with a rack rod operated by a stepping motor (such as a high-concentration methanol cartridge and a micro syringe shown in FIG. 1). FIG.
[0055]
The micro syringe 14 has a breakage supply nozzle 26 that penetrates the center of the blind end and communicates with the inlet 27 of the liquid flow path 23, and loads the high concentration methanol cartridge 15 filled with high concentration methanol into the micro syringe 14. The sealing of the high-concentration methanol cartridge 15 is broken by being pressed by the piston 17.
[0056]
The piston 17 with the rack rod 17a is driven by a stepping motor 18 with a pinion 18a, and the rotation angle of the rotating shaft of the stepping motor 18 can be accurately controlled from the outside. The high-concentration methanol cartridge 15 shrinks in the direction of its movement according to the moving distance, so that a precise amount of high-concentration methanol can be injected into the aqueous methanol solution. .
[0057]
Further, since the rotation axis of the stepping motor 18 can maintain the rotation angle, the position of the piston 17 with the rack rod 17a can be fixed, and as a result, the high-concentration methanol cartridge 15 and the aqueous methanol solution can be pressurized.
[0058]
Here, since the high-concentration methanol injection port 27 is a pinhole, when the piston 17 with the rack rod 17a is not operated, the outflow of the high-concentration methanol into the methanol aqueous solution can be almost ignored. it can.
The same applies to the water cartridge 16.
[0059]
FIG. 6 shows an adjusting means (a high-concentration methanol cartridge and a micro-syringe) for adjusting the injection amount of fuel into the methanol flow path by pressurizing the liquid cartridge via a piston operated by a stepping motor, which is different from FIG. FIG.
[0060]
Inside the micro syringe 14, a high-concentration methanol cartridge 15 filled with high-concentration methanol whose seal has been broken by the puncture supply nozzle 26 is loaded. A gear is cut around the outer periphery of the rod piston 29 and penetrates a guide groove 14 a extending to one side of the micro syringe 14, and the rotational force is applied to the rod piston 29 by orthogonal engagement with the cylindrical worm 28 rotated by the stepping motor 18. The transmission can be performed, so that the high-concentration methanol cartridge 15 can be pressurized.
[0061]
Here, comparing the configuration of FIG. 6 with the configuration of FIG. 5, by further juxtaposing the rotation axis direction of the stepping motor 18 and the longitudinal direction of the micro syringe 14 to be parallel, further downsizing is possible.
The same applies to the water cartridge 16.
[0062]
[Details of high-concentration methanol cartridge]
FIG. 7 is a cross-sectional view of a high-concentration methanol cartridge partially having a thin portion. The high-concentration methanol cartridge 15a is capable of extending and contracting in a bellows structure on its longitudinal side surface.
[0063]
In the end surface of the high-concentration methanol cartridge 15a, a portion (a crack generation portion 30) where a crack is generated by the puncture supply nozzle 26 is thinned, and the seal is easily broken by the puncture supply nozzle 26. Is possible. In addition, the periphery of the thick register portion should be thick enough to secure strength in the sense of reinforcement so as not to increase the crack when the seal is broken by the breakage supply nozzle 26. desirable.
[0064]
FIG. 8 is a cross-sectional view of a high-concentration methanol cartridge sealed from inside by small balls. The high-concentration methanol cartridge 15b has a bellows structure on its longitudinal side surface and can be expanded and contracted. A substantially circular hole 31 is provided at one end surface of the high-concentration methanol cartridge 15b and is sealed by a small ball 32, so that the small ball 32 can be easily removed by applying pressure from the outside to the inside. Has become. In order to prevent the small ball 32 from accidentally moving, a stopper 33 having a tapered inner peripheral surface is provided so as to be continuous with the hole 31.
[0065]
FIG. 9 is a perspective view of the high-concentration methanol cartridge 15c having a substantially rectangular surface (a crack occurrence location 34 on one surface thereof) whose expansion direction is the normal direction, unlike FIGS. By making the shape of the surface having the expansion / contraction direction as the normal direction not a circle but a substantially rectangle, the ratio of the volume of the cartridge 15c to the constant volume is improved, and the size of the system device can be further reduced. .
The same applies to the water cartridge 16 and, in general, to the liquid cartridge.
[0066]
(System device example 2)
FIG. 10 is a schematic diagram of a configuration of a small fuel cell system device according to one embodiment of the present invention. It is assumed that the fuel is an aqueous methanol solution.
[0067]
The small fuel cell system device γ includes a fuel cell 4 composed of a solid polymer electrolyte membrane 1, an air electrode 2 and a fuel electrode 3, an air supply means 6 composed of a blower 5 for sending air to the air electrode 2, Fuel supply means 35 for supplying fuel to the fuel cell.
The fuel supply means 35 includes the micro syringe 14, a high-concentration methanol cartridge 15, a water cartridge 16, and an inkjet 36 for injecting high-concentration methanol and water.
[0068]
In addition, a micro gear pump 19 for circulating a methanol aqueous solution as a fuel and a methanol aqueous solution concentration sensor 21 are interposed in a methanol flow path.
[0069]
Since methanol and water in the aqueous methanol solution are consumed by the power generation, the high-concentration methanol from the high-concentration methanol cartridge 15 and the water from the water cartridge 16 are supplied to the inkjet 36 in the process of circulation by the micro gear pump 19. Each of them is poured into an aqueous methanol solution to adjust the concentration.
[0070]
FIG. 11 is a cross-sectional view of an adjusting means (constituted by a high-concentration methanol cartridge, a macro syringe using an ink jet, or the like) for adjusting the amount of fuel injected into the methanol flow path by ink jet.
[0071]
Inside the micro syringe 14, high-concentration methanol which has been broken by the puncture supply nozzle 26, which penetrates the center of the blind end, communicates with the inlet 27 of the fuel channel 23, and sets the heating means 37 on the way, is set. A filled high-concentration methanol cartridge 15 is loaded, and heated by a heating means (heater or the like) 37 to generate bubbles 38. When the bubbles 38 become large, high-concentration methanol is supplied through the inlet 27. It has an inkjet structure that is injected into an aqueous methanol solution.
[0072]
(Example of method)
A fuel cell power generation method according to an embodiment of the present invention will be described on the assumption that the above-described system device examples 1 and 2 are applied.
[0073]
The fuel cell power generation method uses the correlation between the AC impedance and the concentration in advance based on the AC impedance measured by the concentration sensor 21 of the small fuel cell system devices β and γ used to execute the method. The concentration in the flow path (the methanol flow path 23 in the above description) is measured.
[0074]
Then, an input of a measurement result from the concentration sensor 21 is received so that the measured concentration becomes the reference concentration of the fuel cell 4, and a control signal is sent to the stepping motor 18 or the heating means 37 in accordance with the input. Automatic control is performed by a control means (such as a computer) for outputting.
According to the control signal, the fuel supply means 13 and 35 inject the fuel (methanol, water) into the fuel passage 23 so as to compensate for the decrease in the fuel consumed by the power generation.
[0075]
At this time, when the fuel supply means 13 of the small fuel cell system device β is used (FIGS. 5 and 6), the stepping motor 18 is operated by transmitting the control signal, whereby the pistons 17 and 29 are moved, When the liquid methanol cartridge 15 is pressurized, the bellows shrinks, and as a result, methanol of a volume corresponding to the shrinkage of the bellows is injected into the methanol aqueous solution in the methanol channel 23 from the inlet 27.
[0076]
At this time, when the fuel supply means 35 of the small fuel cell system device γ is used (FIG. 11), the heating means 37 is controlled by the transmission of the control signal, whereby the heating state changes and the fuel is injected from the inlet 27. By changing the volume of the solution, the injection volume is controlled as a result.
[0077]
The small fuel cell system devices β and γ are connected to a fuel (methanol flow path 23 in the previous example) in a fuel flow path (methanol flow path 23 in the above example) by a micro gear pump 19 including a pair of gears 25 formed by a micromachining technique. Aqueous solution) is circulated. Further, under a state where the pressure is increased to the atmospheric pressure or more by the fuel supply means 13, unnecessary gas such as carbon dioxide generated in the fuel cell 4 or the like is discharged by the vent filter 20, so that the fuel cell 4 Prevents decline in power generation capacity.
[0078]
In the above description, the direct methanol type using methanol as a fuel will be described, but the present invention is not limited to the point that the fuel is methanol or the direct methanol type.
As for the shape of the liquid cartridge (for example, the high-concentration methanol cartridge 15 and the water cartridge 16), the cross section is circular, elliptical, n-sided (n ≧ 3), and n-sided with rounded corners (n ≧ 3). 3) and the like.
[0079]
The embodiment of the present invention has been described above as an example of a system device and an example of a method. However, the object of the present invention is achieved, and the present invention can be implemented with appropriate modifications as long as the following effects are obtained.
[0080]
【The invention's effect】
According to the present invention, the concentration of the liquid fuel can be measured by AC impedance measurement, so that the weight and size of the system device can be reduced, and the concentration can be accurately measured by simple means. Further, by using a micro gear pump in the circulation of the liquid fuel, it is possible to reduce the size and weight of the conventional liquid feed pump.
[0081]
Further, the liquid fuel is supplied by a bellows structure cartridge, and the liquid fuel is injected by a stepping motor, so that the liquid fuel can be easily carried. Injection can be performed accurately. Moreover, since the liquid fuel can be injected while being pressurized, unnecessary gas in the fuel can be easily removed through a vent filter having a continuous porous structure. The present invention has excellent effects represented by the above.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a configuration of a small fuel cell system device according to an embodiment of the present invention.
FIG. 2 is a sectional view of the concentration sensor of FIG.
FIG. 3 is a diagram showing a relationship between methanol concentration and impedance for the concentration sensor of FIG. 1;
FIG. 4 is a sectional view of the micro gear pump of FIG. 1;
FIG. 5 is a sectional view of the high-concentration methanol cartridge and the microsyringe of FIG. 1;
FIG. 6 is a cross-sectional view of a high-concentration methanol cartridge and a micro syringe, which is different from FIG.
FIG. 7 is a sectional view of the high-concentration methanol cartridge of FIG.
FIG. 8 is a cross-sectional view of a high-concentration methanol cartridge different from FIG.
FIG. 9 is a perspective view of a high-concentration methanol cartridge different from FIGS.
FIG. 10 is a schematic diagram of a small fuel cell system device configuration different from FIG. 1;
FIG. 11 is a cross-sectional view of a macro syringe using a high-concentration methanol cartridge and ink jet.
FIG. 12 is a configuration diagram of a direct methanol fuel cell system device as an example of a conventional technique.
[Explanation of symbols]
1: Solid polymer electrolyte membrane
2 ... Air electrode
3. Fuel electrode
4: Fuel cell
5… Blower
6. Air supply means
7. Fuel supply means
8… Methanol tank
9 ... Water tank
10 ... Liquid sending pump
11 ... gas-liquid separator
12 ... Condenser
13. Fuel supply means
14 ... Micro syringe
15 High concentration methanol cartridge
16 ... Water cartridge
17 ... Piston with rack rod
18 ... Stepping motor with pinion
19 ... Micro gear pump
20… Vent filter
21: concentration sensor
22 ... Pressure sensor
23: methanol flow path (fuel flow path)
24 ... Metal probe
25 ... Micro gear
26 ... Opening supply nozzle
27 ... Injection port
28 ... Cylindrical worm
29 ... Rod piston
30: crack occurrence location
31 ... hole
32 ... Small ball
33 ... Stopper
34: Crack occurrence location
35 ... Fuel supply means
36 ... Inkjet
37 ... heating means
38 ... air bubbles
α: Direct methanol fuel cell system
β, γ… Small fuel cell system equipment

Claims (15)

By measuring the AC impedance using a metal probe installed in the fuel flow path connected to the fuel cell, measure the concentration of the fuel, and estimate the amount of fuel to be injected into the fuel flow path,
A fuel cell power generation method comprising: The fuel is
The estimated amount is injected into the fuel flow path by a micro syringe having a piston operated by a stepping motor,
The fuel cell power generation method according to claim 1, wherein: The fuel is
The estimated amount is injected into the fuel flow path with an inkjet,
The fuel cell power generation method according to claim 1, wherein: The liquid fuel in the fuel flow path connected to the fuel cell is circulated by a micro gear pump composed of a pair of gears created by micro machining technology.
A fuel cell power generation method comprising: The fuel in the fuel flow path connected to the fuel cell is constantly pressurized to a pressure higher than the atmospheric pressure, and unnecessary gas generated in the fuel cell is discharged by the vent filter provided in the fuel flow path. Do
A fuel cell power generation method comprising: Fuel cell, air supply means for sending air to the air electrode of the fuel cell, fuel supply means for supplying fuel to the fuel electrode of the fuel cell, fuel supply means and the fuel electrode And a fuel flow path serving as a fuel circulation path.
A metal probe inserted into the fuel flow path as a sensor, comprising a concentration sensor for detecting the concentration of the liquid fuel from the AC impedance,
A small fuel cell system device characterized by the above-mentioned. Fuel cell, air supply means for sending air to the air electrode of the fuel cell, fuel supply means for supplying fuel to the fuel electrode of the fuel cell, fuel supply means and the fuel electrode And a fuel flow path serving as a fuel circulation path.
The fuel supply means,
A liquid cartridge containing the fuel,
A micro syringe for loading the liquid cartridge,
Pressure means for pressurizing the liquid cartridge via a piston operated by a stepping motor, thereby comprising adjusting means for adjusting the amount of fuel injected into the fuel flow path,
A small fuel cell system device characterized by the above-mentioned. Fuel cell, air supply means for sending air to the air electrode of the fuel cell, fuel supply means for supplying fuel to the fuel electrode of the fuel cell, fuel supply means and the fuel electrode And a fuel flow path serving as a fuel circulation path.
The fuel supply means,
A liquid cartridge containing the fuel,
A micro syringe for loading the liquid cartridge,
Adjusting means for adjusting the injection amount of the fuel into the fuel flow path by inkjet,
A small fuel cell system device characterized by the above-mentioned. Fuel cell, air supply means for sending air to the air electrode of the fuel cell, fuel supply means for supplying fuel to the fuel electrode of the fuel cell, fuel supply means and the fuel electrode And a fuel flow path serving as a fuel circulation path.
The fuel flow path is interposed by a micro gear pump consisting of a pair of gears created by micro machining technology.
A small fuel cell system device characterized by the above-mentioned. The fuel flow path,
Unnecessary gas generated inside was interposed in the middle of a porous vent filter that was pressurized and discharged by the adjusting means.
The small fuel cell system device according to claim 7, wherein: The micro syringe is
The liquid cartridge was provided with a puncture supply nozzle which is a trigger for opening by being loaded.
11. The small fuel cell system device according to claim 7, 8 or 10. The liquid cartridge includes:
When the micro-syringe is loaded, the opening portion is made thin by the puncture supply nozzle,
The small fuel cell system device according to claim 11, wherein: The liquid cartridge includes:
It has a hole that is penetrated by the breakage supply nozzle when loaded into the micro syringe, and incorporates a small ball that seals the hole from the inside by increasing the internal pressure to atmospheric pressure or higher.
The small fuel cell system device according to claim 11, wherein: The liquid cartridge includes:
It is a bellows structure that can expand and contract with respect to the loading direction of the micro syringe.
The small fuel cell system device according to claim 7, 8, 10, 11, 12, or 13. The liquid cartridge includes:
The cross section is any one of a circle, an ellipse, an n-sided polygon (n ≧ 3), and an n-sided polygon with rounded corners (n ≧ 3).
15. The small fuel cell system device according to claim 7, 8, 10, 11, 11, 12, 13 or 14.

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