CN1489233A - Direct modified fuel cell system - Google Patents
Direct modified fuel cell system Download PDFInfo
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- CN1489233A CN1489233A CNA031561292A CN03156129A CN1489233A CN 1489233 A CN1489233 A CN 1489233A CN A031561292 A CNA031561292 A CN A031561292A CN 03156129 A CN03156129 A CN 03156129A CN 1489233 A CN1489233 A CN 1489233A
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Abstract
In the direct modified fuel cell system according to the present invention, a methanol concentration measuring device 30 is disposed in a location where the amount of carbon dioxide is relatively small in the circulating passage of the methanol/aqueous solution, so that bubbles of carbon dioxide or impurities are prevented from adhering to the surface of a concentration sensor, whereby the concentration of methanol can be detected with high accuracy. Also, as the concentration of methanol is different depending on temperature condition of the methanol/aqueous solution, a temperature sensor 32 is disposed close to a concentration sensor 31 such as a quartz resonator type or ultrasonic type which calculates the concentration of the methanol through viscosity of the liquid, corrects the concentration of methanol affected by temperature conditions, and measures the concentration of methanol with high accuracy.
Description
Technical Field
The present invention relates to a direct modification type fuel cell system.
Background
Conventionally, as a technique for measuring the ethanol concentration of a solution of water and ethanol, a viscosity measuring apparatus disclosed in japanese patent No. 2,654,648 is known. This conventional technique includes a quartz resonator in contact with a sample liquid and a viscosity measuring means using a resistance component of an equivalent circuit of the quartz resonator as an index of viscosity of the sample liquid, measures impedance at a frequency near a resonance frequency of the quartz resonator, and obtains viscosity from the obtained impedance.
A direct modified fuel cell system using this viscosity measuring device as a fuel concentration measuring device has a configuration shown in fig. 18. The fuel cell system of this concept includes a fuel cell 1, an air pump 2 that supplies air to an air electrode 11 of the fuel cell 1, a methanol/water tank 3 that stores an aqueous methanol solution as a fuel, and a methanol/water pump 4 that supplies the aqueous methanol solution as a fuel from the methanol/water tank 3 to a fuel electrode 12 of the fuel cell 1. A methanol sensor 5 for monitoring the methanol concentration in the fuel is disposed so as to be immersed in the liquid layer in the methanol/water tank 3. Reference numeral 13 in the fuel cell 1 denotes a solid polymer electrolyte membrane.
However, in the case of such a direct reforming fuel cell system, the following technical problem arises when the methanol concentration of the fuel is to be measured.
(1) The problem of bubble adhesion to the methanol sensor 5
The power generation of the fuel cell causes the anode (fuel electrode 12) to generate
(chemical formula 1)
Such a reaction, therefore, carbon dioxide CO is always mixed2The solution is returned to the methanol/water tank 3. For this reason, bubbles of carbon dioxide are liable to adhere to the methanol sensor 5 in the methanol/water tank 3. In addition, since the reaction temperature of the fuel cell 1 is high, the aqueous solution is easyBubbles of steam of methanol and water are also liable to adhere by vaporization. For this reason, the detection accuracy of the methanol sensor 5 is degraded.
(2) Problem of adhesion of impurities to methanol sensor
The methanol/water solution is retained in the methanol/water tank 3 and flows little, so that impurities are likely to adhere to the methanol sensor 5. For this reason, the detection accuracy of the methanol sensor 5 is degraded.
From the above problems and the characteristics of conventional viscosity measuring apparatuses, there are the following technical problems.
(1) Depending on the measured liquid temperature, the oscillation frequency changes even for the same concentration, and sufficient compensation is required.
(2) Since measurement cannot be performed when impurities adhere to a portion of the quartz resonator, measures need to be taken.
(3) Since the power generation reaction of the fuel cell generates bubbles in the methanol aqueous solution as the fuel, it is necessary to prevent the bubbles from being affected.
(4) Since the temperature rise of the aqueous methanol solution deteriorates the detection characteristics of the quartz resonator, it is necessary to lower the temperature to an appropriate temperature.
Disclosure of Invention
The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a direct modification type fuel cell system capable of accurately measuring the methanol concentration by finding a solution temperature countermeasure and a solution bubble countermeasure.
The direct modification type fuel cell system of the invention of claim 1 is characterized in that: the fuel cell system comprises a direct modification type fuel cell, an air pump for supplying air to an air electrode of the fuel cell, a methanol/water tank for storing a methanol/water solution in which methanol and water are mixed as fuel, a methanol/water pump for supplying the methanol/water solution from the methanol/water tank to a fuel electrode of the fuel cell, a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range, and a methanol sensor for monitoring the methanol concentration in the methanol/water solution; wherein the methanol sensor is installed in a pipe between an outlet of the methanol/water pump and a fuel inlet of the fuel cell or a pipe between the methanol/water tank and the methanol/water pump.
The direct modification type fuel cell system of the invention of claim 2 is characterized in that: the fuel cell system comprises a direct modification type fuel cell, an air pump for supplying air to an air electrode of the fuel cell, a methanol/water tank for storing a methanol/water solution in which methanol and water are mixed as fuel, a methanol/water pump for supplying the methanol/water solution from the methanol/water tank to a fuel electrode of the fuel cell, a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range, and a methanol sensor for monitoring the methanol concentration in the methanol/water solution; wherein the methanol sensor is installed in a chamber provided in communication with a pipe between an outlet of the methanol/water pump and a fuel inlet of the fuel cell or in a chamber provided in communication with a pipe between the methanol/water tank and the methanol/water pump.
The invention of claim 3 is characterized in that, in addition to the direct modification type fuel cell system of the invention of claim 2: and a heat sink is arranged in the cavity.
The direct modification type fuel cell system of the invention of claim 4 is characterized in that: the fuel cell system comprises a direct modification type fuel cell, an air pump for supplying air to an air electrode of the fuel cell, a methanol/water tank for storing a methanol/water solution in which methanol and water are mixed as fuel, a methanol/water pump for supplying the methanol/water solution from the methanol/water tank to a fuel electrode of the fuel cell, a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range, and a methanol sensor for monitoring the methanol concentration in the methanol/water solution; wherein the methanol sensor is provided at a gas position not submerged by the methanol/water solution during normal operation in the methanol/water tank, and the control circuit stops the methanol/water pump when the methanol sensor measures the methanol concentration, and measures the methanol concentration after the methanol/water solution in the methanol/water tank rises to a liquid level at which the methanol sensor is submerged.
The direct modification type fuel cell system of the invention of claim 5 is characterized in that: a direct reforming type fuel cell, an air pump for supplying air to an air electrode of the fuel cell, a methanol/water tank for storing a methanol/water solution in which methanol and water are mixed as fuel, a methanol/water pump for supplying the methanol/water solution from the methanol/water tank to a fuel electrode of the fuel cell, a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range, a bypass path having a larger volume except for a circulation path of the methanol/water solution in normal operation, and a path switching means for the circulation path and the bypass path in normal operation, and a methanol sensor for monitoring the methanol concentration in the methanol/water solution; said methanol sensor is positioned to be not flooded by the methanol/water solution when performing normal operation in said methanol/water bath; wherein the control circuit switches the path switching means from the circulation path during the normal operation to a bypass path when the methanol sensor measures the methanol concentration, and causes the methanol/water solution to flow to the bypass path, thereby lowering the liquid level in the methanol/water tank and bringing the methanol sensor into contact with the gas, and thereafter, returns the path switching means from the bypass path to the circulation path during the normal operation to cause the methanol/water solution to circulate and return to a state in which the methanol sensor is submerged, and then measures the methanol concentration.
The direct modification type fuel cell system of the invention of claim 6 is characterized in that: the fuel cell system comprises a direct modification type fuel cell, an air pump for supplying air to an air electrode of the fuel cell, a methanol/water tank for storing a methanol/water solution in which methanol and water are mixed as fuel, a methanol/water pump for supplying the methanol/water solution from the methanol/water tank to a fuel electrode of the fuel cell, a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range, and a methanol sensor for monitoring the methanol concentration in the methanol/water solution; wherein the methanol sensor is provided in a pipe for transmitting vibration during operationof the methanol/water pump.
The direct modification fuel cell system of the invention of claim 7 is characterized in that: the fuel cell system comprises a direct modification type fuel cell, an air pump for supplying air to an air electrode of the fuel cell, a methanol/water tank for storing a methanol/water solution in which methanol and water are mixed as fuel, a methanol/water pump for supplying the methanol/water solution from the methanol/water tank to a fuel electrode of the fuel cell, a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range, and a methanol sensor for monitoring the methanol concentration in the methanol/water solution; wherein the methanol sensor is installed at an installation place thereof in a posture parallel to a flow direction of the methanol/water solution.
The invention of claim 8 is characterized in that, in addition to the direct modification type fuel cell system of the invention of claim 7: the methanol sensor is covered with a mesh or porous filter.
In the direct modification fuel cell system according to the present invention as set forth in any one of claims 1 to 8, the methanol sensor is provided at a location where the amount of carbon dioxide gas present in the circulation path of the methanol/aqueous solution is small, the methanol sensor is provided in parallel with the flow of the methanol/aqueous solution, and the filter is provided on the methanol sensor, whereby the adhesion of carbon dioxide bubbles and impurities to the surface of the methanol sensor can be suppressed, and the methanol concentration can be detected with good accuracy.
The invention according to claim 9 is the direct modification fuel cell system according to any one of claims 1 to 8, further including: a temperature sensor for measuring the temperature of the methanol/water solution in addition to the methanol sensor, wherein the control circuit has a temperature compensation operation function for correcting the methanol concentration operation based on the signal detected by the methanol sensor by using the temperature signal detected by the temperature sensor; since the methanol concentration varies depending on the temperature condition of the methanol/aqueous solution, the methanol concentration is accurately measured by compensating for the influence of the temperature condition on the methanol concentration in a methanol sensor that calculates the methanol concentration based on the viscosity of the solution, such as a quartz-oscillator type or ultrasonic type sensor.
The direct modification type fuel cell system of the invention of claim 10 is characterized in that: the fuel cell system comprises a direct modification type fuel cell, an air pump for supplying air to an air electrode of the fuel cell, a methanol/water tank for storing methanol/water solution mixed by methanol and water as fuel, a methanol/water pump for supplying the methanol/water solution to a fuel electrode of the fuel cell from the methanol/water tank, a temperature sensor for measuring the temperature of the fuel cell, a current/voltage measuring unit for measuring the current and voltage of the fuel cell, a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range, and a methanol sensor for monitoring the methanol concentration of the methanol/water solution; the control circuit holds efficiency map data corresponding to current/voltage and temperature conditions generated by the fuel cell, estimates methanol consumption by referring to the efficiency map data based on the measured temperature of the temperature sensor and the measured current and voltage of the current/voltage measuring means, calculates a corresponding methanol replenishment amount, and performs replenishment control.
In the direct reforming fuel cell system according to claim 10, the control circuit holds efficiency map data corresponding to the generated current/voltage and temperature conditions of the fuel cell, estimates the methanol consumption amount with reference to the efficiency map data based on the temperature measured by the temperature sensor and the current and voltage measured by the current/voltage measuring unit, calculates the corresponding methanol replenishment amount, and performs replenishment control, thereby accurately maintaining the methanol concentration within the reference range.
The direct modification type fuel cell system of the invention of claim 11 is characterized in that: the fuel cell system comprises a direct modification type fuel cell, an air pump for supplying air to an air electrode of the fuel cell, a methanol/water tank for storing methanol/water solution mixed by methanol and water as fuel, a methanol/water pump for supplying the methanol/water solution to a fuel electrode of the fuel cell from the methanol/water tank, a temperature sensor for measuring the temperature of the fuel cell, a current/voltage measuring unit for measuring the current and voltage of the fuel cell, a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range, and a methanol sensor for monitoring the methanol concentration of the methanol/water solution; the control circuit calculates the consumption of methanol by using the generated current/voltage and temperature conditions of the fuel cell and predetermined parameters stored in advance, and performs control to replenish methanol in an amount corresponding to the consumption.
In the direct modification fuel cell system of claim 11, the control circuit calculates the amount of methanol consumed using the generated current/voltage and temperature conditions of the fuel cell and predetermined parameters stored in advance, and performs control to supplement the amount of methanol corresponding to the amount of methanol consumed, thereby accurately maintaining the methanol concentration within the reference range.
Drawings
Fig. 1 is a block diagram of embodiment 1 of the present invention.
Fig. 2 is a block diagram of embodiment 2 of the present invention.
Fig. 3 is a block diagram of embodiment 3 of the present invention.
Fig. 4 is a block diagram of embodiment 4 of the present invention.
FIG. 5 is a flowchart of the methanol concentration measuring process according to embodiment 4.
Fig. 6 is a block diagram of a methanol concentration measuring apparatus used in embodiment 4.
Fig. 7 is a block diagram of embodiment 5 of the present invention.
Fig. 8 is a block diagram of embodiment 6 of the present invention.
Fig. 9 is a block diagram of embodiment 7 of the present invention.
Fig. 10 is a sectional view showing an installation state of a methanol sensor in embodiment 8 of the present invention.
Fig. 11 is a cross-sectional view of a modification of embodiment 8 of the present invention in which a methanol sensor is covered with a filter.
Fig. 12 is a block diagram of embodiment 9 of the present invention.
Fig. 13 is an explanatory view of an operation mode of the fuel cell of embodiment 9.
Fig. 14 is a flowchart of the methanol concentration measurement process according to embodiment 9.
Fig. 15 is an explanatory diagram of an efficiency map using a control circuit in embodiment 9.
Fig. 16 is a flowchart of the process of estimating the methanol concentration in the process of measuring the methanol concentration according to embodiment 9.
Fig. 17 is a flowchart of the methanol concentration measurement process according to embodiment 10 of the present invention.
Fig. 18 is a block diagram of the proposed direct modification type fuel cell system.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to the drawings. Fig. 1 shows a direct modified fuel cell system according to embodiment 1 of the present invention. The fuel cell system of the present embodiment includes a polymer electrolyte fuel cell 1, an air pump 2 for supplying air to an air electrode of the fuel cell 1, a methanol/water tank 3 for storing a solution of methanol and water as fuel, and a methanol/water pump 4 for supplying a methanol aqueous solution as fuel from the methanol/water tank 3 to a fuel electrode of the fuel cell 1. The polymer electrolyte fuel cell 1 includes an air electrode 11, a fuel electrode 12, and a polymer electrolyte membrane 13 as an electrolyte membrane.
A methanol sensor 5 for monitoring the concentration of methanol in the fuel is installed in the pipe 7 between the outlet of the methanol/water pump 4 and the fuel inlet of the fuel cell 1.
During the actual operation of the fuel cell 1, methanol, which is a raw material fuel, is consumed, producing carbon dioxide 14. The carbon dioxide 14 is recovered from the fuel cell 1 to the methanol/water tank 3, and is released from the methanol/water tank 3 to the atmosphere through the exhaust stack 6. On the other hand, water is produced by the fuel cell reaction, so water in the methanol/water solution is increasing during actual operation. In order to effectively maintain the fuel cell reaction, it is necessary to maintain the methanol concentration in the methanol/water solution at about 4%, and if the methanol concentration decreases, a predetermined amount of methanol having a concentration of 10% is supplied from a methanol tank (not shown) to the methanol/water tank 3, and control is performed to maintain the methanol concentration at about 4%. For this reason, it is necessary to monitor the methanol concentration in the methanol/water solution as the fuel liquid supplied to the fuel electrode 12 of the fuel cell 1, and to monitor the methanol concentration by the methanol sensor 5.
In this way, in the direct modified fuel cell system according to embodiment 1, the following technical advantages are obtained by installing the methanol sensor 5 for monitoring the methanol concentration in the pipe 7 between the outlet of the methanol/water pump 4 and the fuel inlet of the fuel cell 1.
(1) The methanol/water solution pressure is high in the fuel circulation path, and the methanol sensor 5 is provided at a place where the generation of bubbles 14 is small, so that the influence of the bubbles 14 is small, and the methanol concentration can be measured with high accuracy.
(2) In addition, by providing the methanol sensor 5 to a position immediately before the reaction site of the fuel cell, such as near the inlet of the fuel electrode 12 of the fuel cell 1, the methanol aqueous solution temperature and the aqueous solution concentration can be managed more accurately than in the past.
Next, a direct modified fuel cell system according to embodiment 2 of the present invention will be described with reference to fig. 2. The fuel cell system of embodiment 2 is characterized in that: a chamber 9 communicating with a pipe 8 between the methanol/water tank 3 and the methanol/water pump 4 is provided, and a methanol sensor 5 is provided in the chamber 9. The pipe 8 may be provided with fins 10 as necessary. The same elements as those in embodiment 1 among other constituent elements are denoted by the same reference numerals.
The chamber 9 communicating with the pipe 8 is a place which is not easily affected by the bubbles 14 of carbon dioxide in the methanol aqueous solution, and the methanol concentration can be measured in a state isolated from the fuel aqueous solution in which the bubbles 14 are mixed. Further, if the heat sink 10 is provided to cool the inside of the chamber 9, the temperature of the aqueous solution is lowered, whereby the generation of the bubbles 14 can be suppressed, and the influence of the bubbles 14 can be further avoided.
The chamber 9 may be provided so as to communicate with the pipe 7 as in embodiment 1, and may be provided with fins 10. Thus, the same technical advantages as those of embodiment 2 can be obtained.
Next, a direct modified fuel cell system according to embodiment 3 of the present invention will be described with reference to fig. 3. The 3 rd embodiment is characterized in that a methanol sensor 5A is provided in the pipe 7 as in the 1 st embodiment shown in fig. 1, and a methanol sensor 5B is provided in the chamber 9 communicating with the pipe 8 as in the 2 nd embodiment shown in fig. 2.
According to the configuration of embodiment 3, the advantage of eliminating redundant measurement data is achieved by measuring the methanol concentration by the 2 methanol sensors 5A and 5B, and switching can be made suchthat, at the time of system start-up, a concentration measurement value obtained by the methanol sensor 5A capable of measuring the methanol concentration of the methanol/water solution actually supplied to the fuel cell 1 at a position close to the fuel cell 1 is used; at the rated output, a concentration measurement value obtained by the methanol sensor 5B in the chamber 9, which can perform measurement at a temperature suitable for methanol concentration detection, is used.
Next, a direct modified fuel cell system according to embodiment 4 of the present invention will be described with reference to fig. 4. The fuel cell system of embodiment 4 is characterized in terms of control functions. In the direct reforming type fuel cell systems of the respective embodiments 1 to 3 shown in fig. 1 to 3, carbon dioxide is generated at the fuel electrode 12 by the actual power generation reaction of the fuel cell 1, and this carbon dioxide is mixed as bubbles 14 into the fuel aqueous solution and is transported from the fuel cell 1 to the methanol/water tank 3. In the methanol/water tank 3, most of the bubbles 14 of carbon dioxide are discharged to the atmosphere from the exhaust stack 6 by gas-liquid separation. However, tiny bubbles 14 of carbon dioxide are mixed in the solution and circulated with the methanol/water solution. In view of this, in the fuel cell systems according to embodiments 1 to 3, it is considered that the influence of the bubbles 14 is avoided by providing the methanol sensor 5 in the pipe 7 or the pipe 8 or the chamber 9 provided in communication with these pipes, which is a place where the existence rate of the bubbles 14 is small on the circulation path of the methanol/aqueous solution.
However, even finer bubbles circulate through the fuel circulation path in a state of being mixed in the aqueous solution, and inevitably adhere to the methanol sensor 5 little by little.
Therefore, in the fuel cell system of the present embodiment, when the methanol concentration is measured under the control of the control circuit 20, at least 1 of the auxiliary devices such as the air pump 2 and the methanol/water pump 4 is stopped, and the methanol concentration is measured in a state in which the generation of bubbles 14 in the methanol/water tank 3 is suppressed.
The control circuit 20 includes a drive circuit 21 for controlling the start/stop and the rotation speed of the air pump 2 and the methanol/water pump 4, an output control circuit 22, and a CPU23 for controlling the programs.
In the present embodiment, in order to measure the methanol concentration, a chamber 9 is provided in communication with the pipe 7 extending from the methanol/water pump 4 to the fuel inlet of the fuel cell 1, and a methanol concentration measuring device 30 having a concentration sensor 31 and a temperature sensor 32 is provided in the chamber 9.
Next, the methanol concentration measurement control of the direct modified fuel cell system according to the present embodiment will be described with reference to the flowchart of fig. 5.
Step S1: when the concentration is measured, at least 1 of the auxiliary devices of the power generation system (here, the air pump 2) such as the air pump 2 and the methanol/water pump 4 is stopped to suppress the power generation reaction and thereby suppress the generation of carbon dioxide, and as a result, the generation of bubbles in the methanol/water tank 3 is suppressed.
Step S2: the methanol concentration is calculated from the methanol sensor 5 and the temperature sensor 25 provided in the chamber 9 communicating with the pipe 7.
Step S3: if the calculation result of the methanol concentration is within the preset reference range, it is determined that the methanol concentration is detected as "positive", and the process proceeds to step S5. If "not," the process proceeds to step S4.
Step S4: since there is a possibility that bubbles may adhere to the sensors 5 and 25, the amount of operation of the methanol/water pump 4 is changed to eliminate bubbles. After this control, the process returns to step S2 again to measure the methanol concentration.
Step S5: the methanol concentration measurement is completed, and the auxiliary devices of the power generation system are returned to a normal operation state.
In this way, in the direct modified fuel cell system according to embodiment 4, since bubbles are likely to adhere to the methanol concentration sensors during operation, the methanol concentration and the temperature are measured after the operation of the fuel cell is stopped or a mode capable of suppressing the generation of bubbles is formed, and the methanol concentration is calculated from the result of measurement, whereby the methanol concentration can be measured with high accuracy.
The methanol concentration measuring apparatus 30 used in the fuel cell system of embodiment 4 has a configuration shown in fig. 6, in which a concentration sensor 31 such as a quartz resonator and a temperature sensor 32 composed of a general temperature sensor element are fixed to a partition wall 9A of a chamber 9 by a fixing member 33, and the apparatus further includes a control interface 34, and the control interface 34 applies a vibration voltage to the concentration sensor 31 outside the chamber 9, extracts a resonance signal, supplies a current to the temperature sensor 32, and extracts a temperature detection result.
In japanese patent No. 2,654,648 as a conventional example, no description is given of temperature compensation of a viscosity measuring device. However, (1) since the temperatureenvironment changes the oscillation frequency of the crystal oscillator used for the concentration sensor 31, temperature compensation is required in actual use; (2) in order to compensate the temperature of the concentration sensor 31, it is necessary to provide a temperature sensor 32 in a position very close to the concentration sensor 31, because of the necessity of measuring the ambient temperature of the concentration sensor 31.
In view of this technical necessity, in the methanol concentration measuring device 30 used in the fuel cell system of the present embodiment, the concentration sensor 31 and the temperature sensor 32 are integrated by the fixing member 33 for the purpose of measuring the methanol concentration, and the control interface 34 for these sensor groups is also integrated by the fixing member 33.
The control interface 34 sends the temperature detection signal of the temperature sensor 32 to the control circuit 20 together with the resonance frequency signal of the concentration sensor 31. The control circuit 20 holds a temperature compensation value correspondence table, and the CPU23 refers to the data in the table to correct the resonance frequency of the concentration sensor 31, obtains the original resonance frequency, calculates the methanol concentration corresponding to the corrected resonance frequency, and performs control to maintain the methanol concentration in the methanol/water solution of the circulated methanol/water at about 4%.
The methanol concentration measuring apparatus 30 having the configuration shown in fig. 6 may be used in place of the methanol sensor 5 in embodiments 1 to 3, or may be used in each of the following embodiments.
As a measure for suppressing adhesion of bubbles to the methanol sensor 5 or the concentration sensor 31 of the methanol concentration measuring device 30 used in the fuel cell systems of embodiments 1 to 4, surface roughness of several hundred nanometers is ground to several tens of nanometers. In addition, there are methods of applying hydrophilic materials to the sensor surface.
In the latter coating material, for example, silicon dioxide (SiO) is used2) Titanium oxide, zirconium oxide, aluminum oxide, or combinations thereof. Table 1 shows the applicable coating materials, coating methods, and surface conditions.
(Table 1)
| Trade name | Manufacturer(s) | Kind of base solution | Feature(s) |
| Fulaisha puller (フレツセラ) | Loose electrician | Silica and titania | Dip coating method, transparent |
| Sitoleis gulas (ヒ—トレスグラス) | Rixing science and technology | Silicon dioxide (SiO)2) Class I | Dip coating method, transparent |
| SAG/S-100 | Dayisuo (ダイソ) | Silicon dioxide (SiO)2) Class I | Dip coating method, transparent |
| Shellastaz (セラスタッツ) | Paka processing (パ - カ -processing) | Silicon dioxide (SiO)2) Class I | Spraying, coloring and transparentizing |
| AE-800 | Precision of discharge | Silicon dioxide (SiO)2) Class I | Spraying, coloring and transparentizing |
| Super paint H | Fine chemical engineering of Japan | Silicon dioxide (SiO)2) Class I | Heat resistant coating, spray can, clear |
| Dongding heat polysilazane | Dong-heat syndrome | Silicon dioxide (SixNy) class | Various functional coating films, transparent |
| Ceramic coating | Dayboard institute | Silica, zirconia | Heat-resistant coating, black-and-white, matt |
| Ceramic coating | Hammer house | Silica, zirconia | Dip-coating, corrosion-resistant coating, transparent |
| Yaotolong (アトロン) | Japanese Caoda | Silicon dioxide (SiO)2) Class I | Surface protection, rust prevention and corrosion prevention coating, is transparent |
| Semschlam (スミセラム) | The chemical industry of Japan | Aluminum silicates | 800 ℃ resistant heat-resistant coating, black |
| Pre-ceramic coating | SRI International | Silicon dioxide (SixNy) class | Heat-resistant protective coating, transparent |
| Enamel (ホ—ロ—) | Fuji enamel industry | SiO2+α | Heat-resistant color |
| Plasma CVD | Dipruu Sorpu (ディツプソ—ル) | SiOx | Batch wise production of |
Next, a direct modified fuel cell system according to embodiment 5 of the present invention will be described with reference to fig. 7. As described above, when bubbles or impurities adhere to the surfaces of the methanol sensor 5 and the concentration sensor 31, an error occurs in the concentration measurement. In order to suppress the adhesion of bubbles, when bubbles adhere to the surface of the methanol sensor 5, a method of once lifting the methanol sensor 5 from the aqueous solution is effective.
Therefore, in the fuel cell system according to embodiment 5, the methanol sensor 5 (or the methanol concentration measuring device 30) is installed in the methanol/water tank 3 at a height position where the gas is generated during normal operation. The operation of the methanol/water pump 4 is controlled by the control circuit 20, and when the fuel cell shown in fig. 7(a) is operated, the methanol/water pump 4 is operated to position the methanol sensor 5 in the gas portion in the methanol/water tank 3, and only when the methanol concentration is detected, the methanol/water pump 4 is stopped as shown in fig. 7(b), and most of the methanol/water solution of methanol/water is recovered in the methanol/water tank 3, and the liquid level in the tank is raised to submerge the methanol sensor 5, whereby the adhesion of bubbles to the sensor surface is suppressed when the methanol concentration is measured, and the methanol concentration is accurately measured.
Thus, since the methanol sensor 5 does not come into contact with the liquid during normal operation, the adhesion of bubbles to the surface thereof is suppressed, and the methanol sensor 5 is submerged in the liquid during the measurement of the methanol concentration, so that the methanol concentration can be measured with high accuracy without being affected by the bubbles.
Next, a direct modified fuel cell system according to embodiment 6 of the present invention will be described with reference to fig. 8. The feature of embodiment 6 is that it has a function of temporarily passing the methanol/aqueous solution through flow paths having different path lengths in order to remove bubbles adhering to the methanol sensor 5, thereby lifting the methanol sensor 5.
That is, as shown in fig. 8, a bypass flow path 41 is provided for the circulation flow path 40 in the normal operation, and the flow paths in the normal operation and the concentration measurement are switched by the control circuit 20. The volume of the bypass channel 41 is made larger than the volume of the normal channel 40, so that when the methanol fuel aqueous solution flows into the bypass channel 41, the liquid level of the solution in the methanol/water tank 3 is greatly lowered, and the methanol sensor 5 provided in the tank 3 appears on the gas side from the liquid.
In the fuel cell system according to embodiment 6, as shown in fig. 8(a), during normal operation, the fuel cell generates power while circulating the solution through the normal flow path 40. In this state, the methanol sensor 5 in the methanol/water tank 3 is submerged in the solution.
When the methanol concentration in the aqueous solution is measured, first, as shown in fig. 8(b), the flow path required for the aqueous solution to flow is switched to the bypass flow path 41, so that the liquid level in the methanol/water tank 3 is lowered, and the methanol sensor 5 is once lifted from the solution and brought into contact with the gas.
Thereafter, as shown in fig. (a), the methanol aqueous solution is again caused to flow into the normal flow path 40 and the flow path is restored, so that the liquid level in the methanol/water tank 3 is raised to submerge the methanol sensor 5, and the methanol concentration is measured in this state.
As described above, according to the fuel cell system of embodiment 6, the influence of bubbles can be reduced, and the methanol concentration can be measured by performing the procedure in which bubbles adhering to the surface of the methanol sensor 5 in a submerged state are pulled up from the solution and brought into contact with the gas, thereby removing the bubbles once, andthereafter, the bubbles are immersed again in the solution to measure the methanol concentration with high accuracy.
In the present embodiment, since the methanol/water solution of methanol/water is not used in the normal operation, the bypass channel 41 is not heated by the heat of the power generation reaction, and the bypass channel 41 also serves as a cooling channel, so that the temperature of the methanol/water solution of methanol/water at the time of measuring the methanol concentration can be lowered at once, and the detection accuracy of the sensor can be improved.
Next, a direct modified fuel cell system according to embodiment 7 of the present invention will be described with reference to fig. 9. The fuel cell system of this embodiment is characterized in that the mounting position of the methanol sensor 5 is set in the discharge port of the methanol/water pump 4, and the suction port side and the discharge port side of the methanol/water pump 4 are connected to the vibration isolation joints 51 and 52 by the pipes 7 and 8. Here, reference numeral 53 denotes a buffer of the pump 4.
The methanol/water pump 4 vibrates during operation. Therefore, the discharge port is also vibrated at the same time, and therefore, by providing the methanol sensor 5 in the discharge port, bubbles and impurities adhering to the surface can be removed by shaking by the vibration of the methanol/water pump 4, and the state can be always cleaned.
Thus, according to the fuel cell system of embodiment 7, the adhesion of bubbles and impurities to the methanol sensor 5 can be suppressed, and the methanol concentration can be measured with high accuracy.
Next, a direct modified fuel cell system according to embodiment 8 of the present invention will be described with reference to fig. 10. The present embodiment is characterized by the installation direction of the methanol sensor 5. As shown in fig. 10(a), the methanol sensor 5 is disposed in the pipe 60 through which the methanol/water solution of methanol/water flows, with the detection surface parallel to the flow direction 61.
Thus, the adhesion of bubbles and impurities can be further reduced as compared with the case where the detection surface is arranged in a direction perpendicular to the liquid flow direction 61 as shown in fig. 10 (b).
In this embodiment, as shown in fig. 11, a mesh or a porous filter 63 that does not obstruct the flow of liquid can be provided so as to surround the methanol sensor 5, and thus the adhesion of bubbles and impurities to the surface of the methanol sensor 5 can be further reduced.
Next, a direct modified fuel cell system according to embodiment 9 of the present invention will be described with reference to fig. 12 to 14. When the power generation reaction causes the methanol/water/methanol/water solution to reach a high temperature, it is difficult to measure the methanol concentration by the methanol sensor. Therefore, as shown in fig. 12, the fuel cell system of the present embodiment is characterized in that the control circuit 20 has a function of estimating the methanol concentration from the generated current amount, the amount of methanol to be fed, the efficiency map, the amount of circulating solution, the amount of methanol discharged from the system, and the solution temperature.
The direct modified fuel cell system shown in fig. 12 includes a polymer electrolyte fuel cell 1, an air pump 2 for supplying air to an air electrode of the fuel cell 1, a methanol/water tank 3 for storing a liquid of methanol and water as fuel, and a methanol/water pump 4 for supplying an aqueous methanol solution of the fuel from the methanol/water tank 3 to a fuel electrode of the fuel cell 1, as in embodiment 1. Methanol as fuel is supplied from the methanol tank 71 to the methanol/water tank 3 by the methanol pump 72. Reference numeral 73 denotes a gas-liquid separator connected to the fuel cell 1.
The fuel cell system of the present embodiment includes a control circuit 20 for controlling the driving device. The control circuit 20 includes a drive circuit 21, an output control circuit 22, a CPU23, and an efficiency map holding unit 24, and controls the methanol concentration of the methanol/water solution of methanol/water and the output of generated power. As information necessary for this control, a methanol concentration signal from the methanol sensor 5, a cell temperature signal from the temperature sensor 74 of the fuel cell 1, and a generated current/voltage signal are input.
The methanol concentration measuring apparatus 30 having the configuration shown in fig. 7 may be mounted for monitoring the solution temperature, but in the present embodiment, temperature signals of the methanol sensor 5 provided in the methanol/water tank 3 and the cell temperature sensor 74 provided for monitoring the reaction of the fuel cell 1 are used.
As shown in fig. 13, when a Ni — Cd battery is used as a battery in the case of charging a battery used for an electric assist bicycle, for example, in the direct modification type fuel cell system, the battery may be discharged for recovery and then recharged. The control circuit 20 monitors the discharge state of the battery, and starts the fuel cell system to recharge if the battery is completely discharged (self-discharge monitoring mode (i) and low-consumption mode (ii)). When the electric assist bicycle is actually running, the operation mode (iii) is shifted, and the control circuit 20 performs power generation control of the fuel cell system in accordance with the state of charge of the battery.
In this operation mode (iii), since the power generation reaction of the fuel cell system occurs, the temperature of the methanol/water solution of methanol/water rises according to the operation state. Therefore, in the methanol sensor 5 commonly used for the ultrasonic sensor and the quartz resonator, the measurement temperature may exceed the allowable temperature, and it may be difficult to measure the methanol concentration.
Therefore, in the fuel cell system of the present embodiment, as shown in the flowchart of fig. 14, the control circuit 20 monitors the temperature of the methanol/water solution of methanol/water (step S11), measures the concentration of the methanol/water solution by the methanol sensor 5 when the concentration is within a temperature range in which the concentration measurement is possible, calculates the supply amount of methanol in accordance with the measured concentration of methanol, and controls the supply of a required amount of methanol from the methanol tank 71 to the methanol/water tank 3 (step S12).
On the other hand, in the temperature monitoring at step S11, when the temperature rises to a temperature at which the concentration measurement by the methanol sensor 5 is not suitable, the control circuit 20 estimates the methanol concentration from the power generation amount, the methanol input amount, and the like (step S13), and controls the methanol supply amount from the estimated value of the concentration (step S14).
The methanol concentration estimation processing is performed based on the amount of generated current, the amount of methanol introduced, the efficiency map, the amount of circulating solution, the amount of discharged system, and the solution temperature, and is performed in accordance with the flowchart of fig. 16.
(1) The methanol concentration is measured in a low temperature state at the time of system startup, and stored as a reference value (step S21).
(2) It is judged whether or not the temperature condition is a condition for enabling concentration measurement (step S22).
(3) For example, as in the case of monitoring the self-discharge of the battery, the concentration of the methanol/aqueous solution is measured in a state where the concentration measurement is possible, and the reference value is updated (steps S22 and S23).
(4) The voltage, current, and cell temperature of the fuel cell 1 are measured, and the amount of methanol consumed is estimated by the holding unit 24 from the prestored voltage, current, and temperature efficiency map shown in fig. 15 (step S24).
The theory of this estimation is as follows.
a. The calorific value per 1ml of methanol was 18.2[ kJ/ml].
b. Fuel cell voltage, current, and operating time are generated energy [ J].
c. The methanol consumption was calculated by multiplying the efficiency.
(math formula 1)
Generating energy/efficiency/unit heating value (18.2)
Methanol consumption
(5) When the temperature conditions are strict, the amount of methanol released from the system is determined from a prestored outside air temperature-evaporation amount map, and the residual methanol amount is corrected (step S25).
(6) The amount of methanol required to be supplemented is estimated from the methanol concentration as a reference value by the measurement in (3) or the methanol consumption amount obtained in (5) (step S26).
(7) Methanol is additionally supplied from the methanol tank 71 to the methanol/water tank 3 in the required replenishment amount calculated in (6) (step S27).
Although a slight amount of methanol is discharged to the outside of the system during the operation, this may be slightly more than that in the drawing, and may be compensated by a simple correction method in which a certain amount is added.
The methanol concentration measurement cycle is set in advance by the system at a fixed cycle, for example, at 1 minute, 5 minutes, 10 minutes, or the like.
Thus, according to the fuel cell system of embodiment 9, even if the temperature of the methanol/water solution of methanol/water rises due to the power generation reaction, the concentration measurement becomes difficult in the general-purpose methanol sensor 5, and the methanol consumption amount is estimated on the control circuit 20 side, and the control for compensating the consumption amount is performed, whereby the methanol concentration in the methanol/water solution can be maintained at an appropriate value.
Next, a direct modified fuel cell system according to embodiment 10 of the present invention will be described with reference to fig. 17. The fuel cell system of the present embodiment is characterized by having a function of controlling the methanol concentration by the mathematical expression calculation processing without using the efficiency map 24 of the fuel cell system of embodiment 9. The hardware configuration is the same as that of embodiment 9, and is shown in fig. 12.
The methanol concentration control of the fuel cell system of the present embodiment is performed as follows.
(1) The current value is continuously measured, and the amount of current is calculated by current time (step S31).
(2) The energy converted into the current is calculated as follows (step S32). First, thefuel cell reacts as follows.
(chemical formula 2)
Here, the charge of 1 electron is 1.60 x 10-19C, it is known that the charge per 1mol of methanol is about 57.8X 104C. Since the current is an electric charge per unit time, the amount of methanol that becomes electricity can be known by observing the amount of current.
(math figure 2)
Amount of current/1 mol of charge
Energy of methanol (a) to become electricity
(3) After that, the chemical reaction heat (heat loss) is calculated (step S33). The heat of reaction generated when the chemical reaction occurs at the cathode (air electrode) and the anode (fuel electrode), i.e., the loss (B) of entropy, is known and stored in advance in the control circuit 20.
(4) Then, the efficiency is calculated from the fuel cell voltage (step S34). Since the theoretical cell voltage of 1.2V is known, the loss of voltage can be obtained by calculating the cell voltage from the fuel cell voltage.
(math figure 3)
(1.2-observed cell voltage)/1.2
Loss of voltage (C)
(5) Then, the energy generated from methanol in the fuel cell reaction is calculated (step S35).
(math figure 4)
(A)/(C)+(B)
Energy (D) used ═ D
(6) Then, the amount of methanol consumed (E) isdetermined from the energy generated from methanol
(math figure 5)
(D) Heat quantity of methanol 18.2kJ/ml
Consumption of methanol (E)
Thus, the current and voltage generated by the fuel cell 1 are continuously monitored, converted into the methanol consumption, and the methanol pump 72 supplies methanol from the methanol tank 71 to the methanol/water tank 3 in an amount corresponding to the consumption.
The methanol sensor 5 measures the methanol concentration at the time of startup, and if the methanol concentration is out of the reference range, methanol is supplemented in a necessary amount.
According to the fuel cell system of this embodiment, the methanol concentration in the methanol/water solution can be maintained within the reference range while the error in the measurement of the concentration by the methanol sensor 5 is minimized.
In each embodiment of the present invention, an ultrasonic sensor may be used as the methanol sensor 5 and the temperature sensor 32 of the methanol concentration measuring device 30 instead of the crystal oscillation sensor.
According to the direct modified fuel cell system of the present invention in claims 1 to 8, the methanol sensor is provided in a place where the amount of carbon dioxide gas existing on the circulation path of the methanol/aqueous solution is small, the methanol sensor is provided in parallel with the flow of the methanol/aqueous solution, and the filter is provided on the methanol sensor, whereby bubbles of carbon dioxide and impurities are prevented from adhering to the surface of the methanol sensor, the methanol concentration is detected with good accuracy, and the methanol concentration is controlled.
According tothe direct modification fuel cell system of claim 9, since the methanol concentration varies depending on the temperature condition of the methanol/aqueous solution, the methanol concentration can be accurately measured and controlled by compensating for the influence of the temperature condition on the methanol concentration in a methanol sensor that calculates the methanol concentration based on the viscosity of the solution, such as a quartz-oscillator type or ultrasonic type sensor.
According to the direct modified fuel cell system of claim 10, the control circuit holds efficiency map data corresponding to the generated current/voltage and temperature conditions of the fuel cell, estimates the methanol consumption amount by referring to the efficiency map data based on the temperature measured by the temperature sensor and the current and voltage measured by the current/voltage measuring means, calculates the corresponding methanol replenishment amount, and performs replenishment control, thereby accurately maintaining the methanol concentration within the reference range.
According to the direct modification fuel cell system of claim 11, the control circuit calculates the amount of methanol consumed using the generated current/voltage and temperature conditions of the fuel cell and predetermined parameters stored in advance, and performs control to supplement the amount of methanol corresponding to the amount of methanol consumed, thereby accurately maintaining the methanol concentration within the reference range.
Claims (11)
1. A direct modification type fuel cell system characterized by comprising:
a direct modification type fuel cell;
an air pump for supplying air to an air electrode of the fuel cell;
a methanol/water tank for storing a methanol/water solution in which methanol is mixed with water as a fuel;
a methanol/water pump for supplying a methanol/water solution from the methanol/water tank to a fuel electrode of the fuel cell;
a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range; and
a methanol sensor for monitoring the methanol concentration in the methanol/water solution,
wherein the methanol sensor is installed in a pipe between an outlet of the methanol/water pump and a fuel inlet of the fuel cell or a pipe between the methanol/water tank and the methanol/water pump.
2. A direct modification type fuel cell system characterized by comprising:
a direct modification type fuel cell;
an air pump for supplying air to an air electrode of the fuel cell;
a methanol/water tank for storing a methanol/water solution in which methanol is mixed with water as a fuel;
a methanol/water pump for supplying a methanol/water solution from the methanol/water tank to a fuel electrode of the fuel cell;
a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range; and
a methanol sensor for monitoring the methanol concentration in the methanol/water solution,
wherein the methanol sensor is installed in a chamber provided in communication with a pipe between an outlet of the methanol/water pump and a fuel inlet of the fuel cell or in a chamber provided in communication witha pipe between the methanol/water tank and the methanol/water pump.
3. The direct modification type fuel cell system according to claim 2, characterized in that: and a heat sink is arranged in the cavity.
4. A direct modification type fuel cell system characterized by comprising:
a direct modification type fuel cell;
an air pump for supplying air to an air electrode of the fuel cell;
a methanol/water tank for storing a methanol/water solution in which methanol is mixed with water as a fuel;
a methanol/water pump for supplying a methanol/water solution from the methanol/water tank to a fuel electrode of the fuel cell;
a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range; and
a methanol sensor for monitoring the methanol concentration in the methanol/water solution,
wherein said methanol sensor is disposed to a gas location within said methanol/water tank that is not flooded by the methanol/water solution when normal operation is performed;
the control circuit stops the methanol/water pump when the methanol sensor measures the methanol concentration, and measures the methanol concentration after the methanol/water solution in the methanol/water tank rises to a level at which the methanol sensor is submerged.
5. A direct modification type fuel cell system characterized by comprising:
a direct modification type fuel cell;
an air pump for supplying air to an air electrode of the fuel cell;
a methanol/water tank for storing a methanol/water solution in which methanol is mixed with water as a fuel;
a methanol/water pump for supplying a methanol/water solution from the methanol/water tank to a fuel electrode of the fuel cell;
a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range;
a bypass path having a larger volume outside the methanol/water solution circulation path in a normal operation, and a path switching means for the circulation path and the bypass path in the normal operation; and
a methanol sensor for monitoring the methanol concentration in the methanol/water solution,
wherein said methanol sensor is positioned to be not flooded by the methanol/water solution when performing normal operation in said methanol/water bath;
when the methanol sensor measures the methanol concentration, the control circuit switches from the circulation path during the normal operation to a bypass path by the path switching means, and causes the methanol/water solution to flow to the bypass path, thereby lowering the liquid level in the methanol/water tank and bringing the methanol sensor into contact with the gas.
6. A direct modification type fuel cell system characterized by comprising:
a direct modification type fuel cell;
an air pump for supplying air to an air electrode of the fuel cell;
a methanol/water tank for storing a methanol/water solution in which methanol is mixed with water as a fuel;
a methanol/water pump for supplying a methanol/water solution from the methanol/water tank to a fuel electrode of the fuel cell;
a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range; and
a methanol sensor for monitoring the methanol concentration in the methanol/water solution,
wherein the methanol sensor is provided in a pipe through which vibration generated during operation of the methanol/water pump is transmitted.
7. A direct modification type fuel cell system characterized by comprising:
a direct modification type fuel cell;
an air pump for supplying air to an air electrode of the fuel cell;
a methanol/water tank for storing a methanol/water solution in which methanol is mixed with water as a fuel;
a methanol/water pump for supplying a methanol/water solution from the methanol/water tank to a fuel electrode of the fuel cell;
a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range; and
a methanol sensor for monitoring the methanol concentration in the methanol/water solution,
wherein the methanol sensor is installed at an installation place thereof in a posture parallel to a flow direction of the methanol/water solution.
8. The direct modification type fuel cell system according to claim 7, characterized in that: the methanol sensor is covered with a mesh or porous filter.
9. The direct modification type fuel cell system according to any one of claims 1 to 8, wherein:
the temperature sensor is used for measuring the temperature of the methanol/water solution at the same time as the methanol sensor;
the control circuit has a temperature compensation calculation function of correcting the methanol concentration calculation based on the signal detected by the methanol sensor using the temperature signal detected by the temperature sensor.
10. A direct modification type fuel cell system characterized by comprising:
a direct modification type fuel cell;
an air pump for supplying air to an air electrode of the fuel cell;
a methanol/water tank for storing a methanol/water solution in which methanol is mixed with water as a fuel;
a methanol/water pump for supplying a methanol/water solution from the methanol/water tank to a fuel electrode of the fuel cell;
a temperature sensor for measuring the temperature of the fuel cell;
a current/voltage measuring unit for measuring a current and a voltage of the fuel cell;
a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range; and
a methanol sensor for monitoring the methanol concentration in the methanol/water solution,
the control circuit holds efficiency map data corresponding to current/voltage and temperature conditions generated by the fuel cell, estimates methanol consumption by referring to the efficiency map data based on the measured temperature of the temperature sensor and the measured current and voltage of the current/voltage measuring means, calculates a corresponding methanol replenishment amount, and performs replenishment control.
11. A direct modification type fuel cell system characterized by comprising:
a direct modification type fuel cell;
an air pump for supplying air to an air electrode of the fuel cell;
a methanol/water tank for storing a methanol/water solution in which methanol is mixed with water as a fuel;
a methanol/water pump for supplying a methanol/water solution from the methanol/water tank to a fuel electrode of the fuel cell;
a temperature sensor for measuring the temperature of the fuel cell, and a current/voltage measuring unit for measuring the current and voltage of the fuel cell;
a control circuit for replenishing methanol so that the methanol concentration of the methanol/water solution circulating in the fuel cell is within a reference range; and
a methanol sensor for monitoring the methanol concentration in the methanol/water solution,
the control circuit calculates the consumption of methanol by using the generated current/voltage and temperature conditions of the fuel cell and predetermined parameters stored in advance, and performs control to replenish methanol in an amount corresponding to the consumption.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002255565A JP3878092B2 (en) | 2002-08-30 | 2002-08-30 | Direct reforming fuel cell system |
| JP255565/2002 | 2002-08-30 |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2006101670260A Division CN100483815C (en) | 2002-08-30 | 2003-08-29 | Direct modified fuel cell system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1489233A true CN1489233A (en) | 2004-04-14 |
| CN1299378C CN1299378C (en) | 2007-02-07 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB031561292A Expired - Fee Related CN1299378C (en) | 2002-08-30 | 2003-08-29 | Direct modified fuel cell system |
| CNB2006101670260A Expired - Fee Related CN100483815C (en) | 2002-08-30 | 2003-08-29 | Direct modified fuel cell system |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2006101670260A Expired - Fee Related CN100483815C (en) | 2002-08-30 | 2003-08-29 | Direct modified fuel cell system |
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| Country | Link |
|---|---|
| JP (1) | JP3878092B2 (en) |
| CN (2) | CN1299378C (en) |
| TW (1) | TWI227574B (en) |
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| CN100433435C (en) * | 2005-10-28 | 2008-11-12 | 英属盖曼群岛商胜光科技股份有限公司 | Fuel concentration control method for direct liquid fuel cell |
| CN100456541C (en) * | 2005-11-22 | 2009-01-28 | 财团法人工业技术研究院 | Liquid fuel battery system |
| CN100530798C (en) * | 2005-12-31 | 2009-08-19 | 财团法人工业技术研究院 | Control system for liquid fuel supplement and control method for liquid fuel supplement of fuel cell |
| CN100464461C (en) * | 2006-02-22 | 2009-02-25 | 英属盖曼群岛商胜光科技股份有限公司 | Fuel supply method for liquid fuel cell |
| CN101188298B (en) * | 2006-11-16 | 2010-05-12 | 南亚电路板股份有限公司 | Direct carbinol fuel battery system without density detection device |
| CN102800878A (en) * | 2011-05-27 | 2012-11-28 | 中国地质大学（武汉） | Integrated direct fuel cell energy storing and supplying system based on liquid hydrogen storage material |
| CN102800878B (en) * | 2011-05-27 | 2015-04-22 | 中国地质大学（武汉） | Integrated direct fuel cell energy storing and supplying system based on liquid hydrogen storage material |
| CN109980243A (en) * | 2019-04-30 | 2019-07-05 | 肇庆学院 | A kind of fuel liquid battery work system and control method |
| CN109980243B (en) * | 2019-04-30 | 2023-11-10 | 肇庆学院 | Liquid fuel cell working system and control method |
Also Published As
| Publication number | Publication date |
|---|---|
| TWI227574B (en) | 2005-02-01 |
| TW200415816A (en) | 2004-08-16 |
| CN1299378C (en) | 2007-02-07 |
| CN1967920A (en) | 2007-05-23 |
| JP3878092B2 (en) | 2007-02-07 |
| CN100483815C (en) | 2009-04-29 |
| JP2004095376A (en) | 2004-03-25 |
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