JP2006073377A - Fuel cell system - Google Patents

Fuel cell system Download PDF

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JP2006073377A
JP2006073377A JP2004256120A JP2004256120A JP2006073377A JP 2006073377 A JP2006073377 A JP 2006073377A JP 2004256120 A JP2004256120 A JP 2004256120A JP 2004256120 A JP2004256120 A JP 2004256120A JP 2006073377 A JP2006073377 A JP 2006073377A
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fuel
pressure side
gas diffusion
diffusion electrode
side gas
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Hisatoshi Fukumoto
久敏 福本
Hironori Kuriki
宏徳 栗木
Takashi Nishimura
隆 西村
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Mitsubishi Electric Corp
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Mitsubishi Electric Corp
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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

<P>PROBLEM TO BE SOLVED: To keep an reduction atmosphere in a fuel cell, even in a power generation halting state of a fuel cell system over a long time, and to suppress electrode deterioration due to corrosion of carbon or degradation of a catalyst. <P>SOLUTION: This fuel cell system is provided with the fuel cell with an electrolyte sandwiched between an oxidizer electrode supplied with an oxidizer and a fuel electrode supplied with a fuel; a reformer for supplying the fuel to the fuel cell; a fuel pressurizing means for pressurizing a part of the fuel; a fuel storage means for storing the fuel pressurized by the fuel pressurization means; a fuel remaining quantity detector for detecting the fuel remaining quantity in the fuel cell; and a fuel depressurizing means for depressurizing the fuel stored in the fuel storage means to supply it to the fuel cell. When it is detected by the fuel remaining quantity detector that the fuel remaining quantity in the fuel cell is smaller than a predetermined value, the fuel stored in the fuel storage means is replenished to the fuel cell by the fuel depressurizing means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、電気化学的な反応を利用して発電する燃料電池システムの技術分野に属するものであり、例えば定置型コジェネレーションシステム等の燃料電池システムにおいて、長期にわたり発電を停止する場合の電極劣化の抑制に関するものである。   The present invention belongs to the technical field of a fuel cell system that generates electricity using an electrochemical reaction. For example, in a fuel cell system such as a stationary cogeneration system, electrode degradation occurs when power generation is stopped for a long period of time. It is related to suppression.

燃料電池は周知のように、電解質を介して一対の電極を接触させ、この一方の電極（燃料電極）に燃料を、他方の電極（酸化剤電極）に酸化剤を供給し、電池内で燃料を電気化学的に酸化反応させることによって化学エネルギーを直接電気エネルギーに変換する装置である。燃料電池には電解質によりいくつかの型があるが、近年高出力の得られる燃料電池として、電解質にプロトン伝導性の固体高分子電解質膜を用いた固体高分子型燃料電池が注目されている。燃料としては水素含有ガス、酸化剤としては空気（酸素）が用いられている。   As is well known, a fuel cell contacts a pair of electrodes via an electrolyte, supplies fuel to one electrode (fuel electrode), and supplies oxidant to the other electrode (oxidant electrode). Is a device that directly converts chemical energy into electrical energy by electrochemically reacting the water. There are several types of fuel cells depending on the electrolyte, but in recent years, a solid polymer fuel cell using a proton-conducting solid polymer electrolyte membrane as an electrolyte has attracted attention as a fuel cell with high output. Hydrogen-containing gas is used as the fuel, and air (oxygen) is used as the oxidant.

このような燃料電池において、燃料電極には水素が滞留し、酸化剤電極には空気が滞留した状態で発電を停止した場合、酸素によって酸化剤電極のカーボンが腐食するとともに触媒が劣化してしまう恐れがある。そこで、従来の燃料電池システムでは、この問題を解決する手段として、水素を含有するパージガスにて燃料電池内の酸素ガスを追い出したのちに密封して発電を停止している（例えば、特許文献１参照。）。   In such a fuel cell, when power generation is stopped in a state where hydrogen stays in the fuel electrode and air stays in the oxidant electrode, the carbon of the oxidant electrode is corroded by oxygen and the catalyst deteriorates. There is a fear. Therefore, in the conventional fuel cell system, as a means for solving this problem, the oxygen gas in the fuel cell is expelled with a purge gas containing hydrogen and then sealed to stop power generation (for example, Patent Document 1). reference.).

特開２００２−９３４４８号公報JP 2002-93448 A

しかしながら、従来の燃料電池システムでは、発電を停止する際に酸素を十分に追い出した場合でも、長期にわたり発電を停止するとガスシール部を通じて燃料電池内部に酸素が侵入することがあった。この酸素がカーボンの腐食や触媒の劣化を引き起こす原因となるという問題があった。   However, in the conventional fuel cell system, even when oxygen is sufficiently expelled when power generation is stopped, when power generation is stopped for a long period of time, oxygen may enter the fuel cell through the gas seal portion. There has been a problem that this oxygen causes carbon corrosion and catalyst deterioration.

本発明は上記のような問題点を解決するためになされたもので、燃料電池システムの長期にわたる発電停止状態でも燃料電池内を還元雰囲気に保ち、カーボンの腐食や触媒の劣化による電極劣化を抑制することを目的としている。   The present invention has been made to solve the above-described problems, and keeps the inside of the fuel cell in a reducing atmosphere even when the power generation of the fuel cell system is stopped for a long period of time, thereby suppressing electrode deterioration due to carbon corrosion and catalyst deterioration. The purpose is to do.

この発明における燃料電池システムは、酸化剤が供給される酸化剤電極と燃料が供給される燃料電極とで電解質を狭持した燃料電池と、燃料電池に燃料を供給するための改質器と、燃料の一部を昇圧するための燃料昇圧手段と、燃料昇圧手段によって昇圧された燃料を貯蔵するための燃料貯蔵手段と、燃料電池内の燃料残量を検知するための燃料残量検知器と、燃料貯蔵手段に貯蔵された燃料を減圧して燃料電池に供給するための燃料減圧手段とを備え、燃料電池の発電停止状態で、燃料残量検知器が燃料電池内の燃料残量が所定値より少なくなったと検知した場合に、燃料貯蔵手段に貯蔵された燃料を燃料減圧手段によって燃料電池に補充するものである。   A fuel cell system according to the present invention includes a fuel cell in which an electrolyte is sandwiched between an oxidant electrode supplied with an oxidant and a fuel electrode supplied with fuel, a reformer for supplying fuel to the fuel cell, Fuel boosting means for boosting a part of the fuel, fuel storage means for storing the fuel boosted by the fuel boosting means, and a fuel remaining amount detector for detecting the remaining amount of fuel in the fuel cell; And a fuel decompression means for decompressing the fuel stored in the fuel storage means and supplying the fuel to the fuel cell, and when the fuel cell is in a power generation stop state, the fuel remaining amount detector has a predetermined amount of fuel remaining in the fuel cell. When it is detected that the fuel cell is less than the value, the fuel stored in the fuel storage means is replenished to the fuel cell by the fuel decompression means.

この発明によれば、長期にわたって燃料電池の発電を停止した状態でも、貯蔵された燃料ガスを燃料電池に供給することで、燃料電池の内部を常に還元雰囲気に維持できる。そのため、燃料電池の内部は酸化雰囲気にさらされることがないため、長期にわたり燃料電池の発電を停止しても電極劣化を抑制できる。   According to the present invention, the inside of the fuel cell can always be maintained in a reducing atmosphere by supplying the stored fuel gas to the fuel cell even when power generation of the fuel cell is stopped for a long period of time. Therefore, the inside of the fuel cell is not exposed to an oxidizing atmosphere, so that electrode deterioration can be suppressed even if power generation of the fuel cell is stopped for a long time.

実施の形態１．
図１は、本発明が適用される燃料電池システムの実施の形態１を説明するための構成図である。燃料電池１０としては、電解質２にパーフルオロスルホン酸膜（例えばデュポン社製ナフィオン（登録商標））を使用した固体高分子形の燃料電池などを用いる。電解質２は、酸化剤電極１と燃料電極３とに挟まれている。酸化剤電極１および燃料電極３には、一般的に高比表面積のカーボンブラック担体に白金などの貴金属微粒子を担持した触媒が用いられる。酸化剤側セパレータ板４の酸化剤供給口より供給された空気は、酸化剤流路を通って酸化剤電極２に供給される。一方、燃料側セパレータ板５の燃料供給口より供給された水素含有ガスは、燃料流路より燃料電極３に供給される。なお、図のように酸化剤電極１と電解質２と燃料電極３と酸化剤側セパレータ板４と燃料側セパレータ板５とを積層したものを単電池とよび、一般には燃料電池１０の出力を高めるために単電池を複数積層する。 Embodiment 1 FIG.
FIG. 1 is a configuration diagram for explaining Embodiment 1 of a fuel cell system to which the present invention is applied. As the fuel cell 10, a polymer electrolyte fuel cell using a perfluorosulfonic acid membrane (for example, Nafion (registered trademark) manufactured by DuPont) as the electrolyte 2 is used. The electrolyte 2 is sandwiched between the oxidant electrode 1 and the fuel electrode 3. For the oxidant electrode 1 and the fuel electrode 3, a catalyst in which noble metal fine particles such as platinum are supported on a carbon black carrier having a high specific surface area is generally used. The air supplied from the oxidant supply port of the oxidant side separator plate 4 is supplied to the oxidant electrode 2 through the oxidant flow path. On the other hand, the hydrogen-containing gas supplied from the fuel supply port of the fuel separator plate 5 is supplied to the fuel electrode 3 from the fuel flow path. In addition, as shown in the figure, a stack of the oxidant electrode 1, the electrolyte 2, the fuel electrode 3, the oxidant side separator plate 4 and the fuel side separator plate 5 is called a single cell, and generally increases the output of the fuel cell 10. For this purpose, a plurality of unit cells are stacked.

改質器２０としては、炭化水素やアルコールを主成分とする原燃料を改質する水蒸気改質型の改質器などを用いる。この燃料電池発電システムの定常発電時において、水素含有ガスを製造するために、改質器２０の改質部２１に、配管１０１を通じて原燃料を投入する。原燃料としては、炭化水素、アルコール系など水素原子を含有する燃料が使用可能である。改質部２１で改質された原燃料は、水素を主成分とする流体に変化し、一酸化炭素（ＣＯ）選択酸化部２１でＣＯを酸化除去し、配管１０２を経由して、燃料電池１０の燃料電極３に供給される。燃料電池１０の酸化剤電極１には、配管１１１を通じて空気が供給される。このとき、酸化剤電極１と燃料電極３とは電気的に外部負荷１４に接続されており、燃料電池１０は外部負荷１４に出力するために発電する。発電の際には、燃料電極側で下記（１）式の反応、酸化剤電極側で下記（２）式の反応が起こる。
Ｈ２＝２Ｈ＋＋２ｅ− 標準電極電位０Ｖ （１）
２Ｈ＋＋２ｅ−＋１／２Ｏ２＝Ｈ２Ｏ 標準電極電位１．２３Ｖ （２） As the reformer 20, a steam reforming reformer that reforms a raw fuel mainly composed of hydrocarbon or alcohol is used. During the steady power generation of the fuel cell power generation system, raw fuel is introduced into the reforming unit 21 of the reformer 20 through the pipe 101 in order to produce a hydrogen-containing gas. As the raw fuel, fuels containing hydrogen atoms such as hydrocarbons and alcohols can be used. The raw fuel reformed by the reforming unit 21 is changed to a fluid containing hydrogen as a main component, CO is oxidized and removed by the carbon monoxide (CO) selective oxidation unit 21, and the fuel cell is connected via the pipe 102. 10 fuel electrodes 3 are supplied. Air is supplied to the oxidant electrode 1 of the fuel cell 10 through the pipe 111. At this time, the oxidant electrode 1 and the fuel electrode 3 are electrically connected to the external load 14, and the fuel cell 10 generates power for output to the external load 14. During power generation, the reaction of the following formula (1) occurs on the fuel electrode side and the reaction of the following formula (2) occurs on the oxidant electrode side.
H 2 = 2H + + 2e - standard electrode potential 0V (1)
2H + + 2e − + 1 / 2O 2 = H 2 O Standard electrode potential 1.23V (2)

発電に使用されなかった空気排ガスは、配管１１２を経由して燃料電池１０の外部に排気される。一方、発電に使用されなかった水素含有ガスは、配管１０３と燃料昇圧手段３０と配管１０４とを経由して改質器２０のバーナ２２に供給され燃焼する。この燃焼熱は改質反応の反応熱として消費される。燃焼の排気は配管１０５を通じて外部に排出される。なお、図では配管１０３と配管１０４との間に燃料昇圧手段３０を配置しているが、これに限定するものではない。例えば、配管１０３と燃料昇圧手段３０と配管１０４とを三方弁で接続し、発電に使用されなかった水素含有ガスが、燃料昇圧手段３０を経由することなくバーナ２２に供給されてもよい。また、配管１０３にバルブを設けておくとメンテナンス上便利である。   Air exhaust gas that has not been used for power generation is exhausted to the outside of the fuel cell 10 via the pipe 112. On the other hand, the hydrogen-containing gas that has not been used for power generation is supplied to the burner 22 of the reformer 20 via the pipe 103, the fuel booster 30, and the pipe 104 and combusts. This combustion heat is consumed as reaction heat of the reforming reaction. The combustion exhaust is discharged to the outside through the pipe 105. In the figure, the fuel booster 30 is arranged between the pipe 103 and the pipe 104, but the present invention is not limited to this. For example, the pipe 103, the fuel booster 30 and the pipe 104 may be connected by a three-way valve, and hydrogen-containing gas that has not been used for power generation may be supplied to the burner 22 without going through the fuel booster 30. Further, it is convenient for maintenance if a valve is provided in the pipe 103.

つぎに、水素含有ガスを貯蔵する過程の動作について説明する。まず、改質器２０から燃料電池１０に供給される水素含有ガスの流量を維持したまま、燃料電池１０から外部負荷１４に供給する出力を低下させる。このとき、燃料電池１０の下流に位置する燃料昇圧手段３０に排出される水素含有ガスの量は、燃料電池１０の出力が低下した分だけ増加する。出力低下で増加した分の水素含有ガスを、燃料昇圧手段３０で昇圧し、配管１０６を経由して燃料貯蔵手段４０に送り貯蔵する。ここで、配管１０６にバルブを設けておくとメンテナンス上便利である。水素昇圧手段３０で昇圧されなかった水素含有ガスは、バーナ２２に定常発電時と同流量が供給され、そこで燃焼されて改質器２０を加熱する。燃料電池１０の出力低下の状態は、燃料貯蔵手段４０に任意の設定量の水素含有ガスが貯蔵されるまで継続される。ここで、水素含有ガスの貯蔵量は、燃料貯蔵手段４０に取り付けられた圧力センサ４１で監視される。貯蔵が終われば、燃料昇圧手段３０の動作を停止し、燃料電池１０の出力を定常発電時の出力まで回復させるか、あるいは、後述する燃料電池１０の停止動作に移行してもよい。   Next, the operation in the process of storing the hydrogen-containing gas will be described. First, the output supplied from the fuel cell 10 to the external load 14 is reduced while maintaining the flow rate of the hydrogen-containing gas supplied from the reformer 20 to the fuel cell 10. At this time, the amount of the hydrogen-containing gas discharged to the fuel booster 30 located downstream of the fuel cell 10 increases by the amount that the output of the fuel cell 10 is reduced. The amount of hydrogen-containing gas increased due to the decrease in output is boosted by the fuel boosting means 30 and sent to the fuel storage means 40 via the pipe 106 for storage. Here, it is convenient for maintenance if a valve is provided in the pipe 106. The hydrogen-containing gas that has not been boosted by the hydrogen booster 30 is supplied to the burner 22 at the same flow rate as that during steady power generation, and is burned there to heat the reformer 20. The output reduction state of the fuel cell 10 is continued until an arbitrary set amount of hydrogen-containing gas is stored in the fuel storage means 40. Here, the storage amount of the hydrogen-containing gas is monitored by a pressure sensor 41 attached to the fuel storage means 40. When the storage is completed, the operation of the fuel booster 30 may be stopped, and the output of the fuel cell 10 may be restored to the output during steady power generation, or the operation may be shifted to a stop operation of the fuel cell 10 described later.

なお、燃料電池１０の出力低下によって燃料昇圧手段３０に排出される水素含有ガスの増量分に比し、燃料昇圧手段３０によって昇圧され燃料貯蔵手段４０に貯蔵される水素含有ガスの流量が少ない場合は、バーナ２２での発熱が増大してしまう。そのため、改質器２０が過熱するので、改質触媒が劣化するとか、熱応力で改質器２０の筐体に亀裂が発生するといった懸念が生じる。また反対に、燃料電池１０の出力低下によって燃料昇圧手段３０に排出される水素含有ガスの増量分に比し、燃料昇圧手段３０によって昇圧され燃料貯蔵手段４０に貯蔵される水素含有ガスの流量が多い場合は、バーナ２２での発熱量が低下してしまう。そのため、改質器２０の温度が低下するので、改質器２０の定常運転が難しくなる。これらの理由により、燃料電池１０の出力低下分に相当する量の水素含有ガスを、燃料昇圧手段３０で昇圧し燃料貯蔵手段４０に貯蔵することが好ましい。   When the flow rate of the hydrogen-containing gas boosted by the fuel booster 30 and stored in the fuel storage unit 40 is smaller than the increase in the hydrogen-containing gas discharged to the fuel booster 30 due to the decrease in the output of the fuel cell 10. Will increase heat generation in the burner 22. Therefore, since the reformer 20 is overheated, there is a concern that the reforming catalyst is deteriorated or a crack is generated in the housing of the reformer 20 due to thermal stress. Conversely, the flow rate of the hydrogen-containing gas that is boosted by the fuel boosting means 30 and stored in the fuel storage means 40 is larger than the increase in the hydrogen-containing gas discharged to the fuel boosting means 30 due to the decrease in the output of the fuel cell 10. When there are many, the calorific value in the burner 22 will fall. For this reason, the temperature of the reformer 20 is lowered, so that steady operation of the reformer 20 becomes difficult. For these reasons, it is preferable that the hydrogen-containing gas in an amount corresponding to the output decrease of the fuel cell 10 is boosted by the fuel boosting means 30 and stored in the fuel storage means 40.

続いて、燃料電池１０の停止動作について説明する。燃料電池１０の停止とは、燃料電池１０からの出力を停止し、かつ改質器２０から燃料電池１０への燃料すなわち水素含有ガスの供給も停止している状態とする。燃料電池１０の停止時には、燃料電池１０の酸化剤電極１に通じるバルブ１１１Ｖおよび１１２Ｖ、さらに燃料電池１０の燃料電極３に通じるバルブ１０２Ｖおよび１０４Ｖが閉じられる。これによって、燃料電池１０の内部（酸化剤電極１および燃料電極３の両極）は水素含有ガスで満たされており、各バルブにより配管を通じて空気中の酸素が侵入しないようにしている。   Next, the stop operation of the fuel cell 10 will be described. The stop of the fuel cell 10 is a state in which the output from the fuel cell 10 is stopped and the supply of fuel, that is, a hydrogen-containing gas from the reformer 20 to the fuel cell 10 is also stopped. When the fuel cell 10 is stopped, the valves 111V and 112V leading to the oxidant electrode 1 of the fuel cell 10 and the valves 102V and 104V leading to the fuel electrode 3 of the fuel cell 10 are closed. As a result, the inside of the fuel cell 10 (both electrodes of the oxidizer electrode 1 and the fuel electrode 3) is filled with a hydrogen-containing gas, and oxygen in the air is prevented from entering through the piping by each valve.

仮に、燃料電池１０の内部へ酸素が侵入した場合、下記反応のように電極構成材料であるカーボンが劣化するおそれがある。
Ｏ２＋４Ｈ＋＋４ｅ−→２Ｈ２Ｏ
Ｃ＋Ｈ２Ｏ→ＣＯ＋２Ｈ＋＋２ｅ− あるいは Ｃ＋Ｈ２Ｏ→ＣＯ２＋４Ｈ＋＋４ｅ−
このような反応を抑えるためには、燃料電池１０の内部はカーボンの酸化還元電位より低い電位に維持する必要がある。水素含有ガスで燃料電池を満たした場合、上記反応におけるカーボンの酸化電位と比べて低い電位に保持されるため、カーボンの酸化劣化が進行しない。ところが、長期にわたる燃料電池１０の停止では、各バルブ等のガスシール部を通じて燃料電池１０内部に酸素が侵入してくる可能性があり、燃料電池１０内部に充填された水素含有ガスだけで還元雰囲気を維持することは難しい。 If oxygen enters the inside of the fuel cell 10, carbon as an electrode constituent material may be deteriorated as in the following reaction.
O 2 + 4H + + 4e − → 2H 2 O
C + H 2 O → CO + 2H + + 2e− or C + H 2 O → CO 2 + 4H + + 4e −
In order to suppress such a reaction, it is necessary to maintain the inside of the fuel cell 10 at a potential lower than the redox potential of carbon. When the fuel cell is filled with a hydrogen-containing gas, the potential is kept lower than the oxidation potential of carbon in the above reaction, so that the oxidation deterioration of carbon does not proceed. However, when the fuel cell 10 is stopped for a long period of time, oxygen may enter the fuel cell 10 through the gas seals such as valves, and the reducing atmosphere can be obtained only with the hydrogen-containing gas filled in the fuel cell 10. Is difficult to maintain.

そこで、この実施の形態では、燃料電池１０内部に連通する部位に、燃料残量検知器として水素残量を検知するセンサ５０を設置している。これによって、燃料電池システムの停止中に、燃料電池１０内部の水素残量を監視できる。センサ５０によって水素残量が任意の設定値より少なくなったことを検知した場合は、燃料減圧手段としての減圧弁１０７Ｖを開き、配管１０７を通じて燃料貯蔵手段４０に貯蔵された水素含有ガスを減圧して、燃料電池１０内部に水素含有ガスを供給する。このとき、バルブ１０８Ｖ（燃料電池１０の発電時は閉）が開き、配管１０８を経由して酸化剤電極１に水素含有ガスが供給される。また、配管１０３を経由して燃料電極３にも水素含有ガスが供給される。センサ５０が燃料電池１０内部に充分量の水素含有ガスを補充できたことを確認したら、燃料減圧手段１０７Ｖを閉じて補充動作を停止する。   Therefore, in this embodiment, a sensor 50 for detecting the remaining amount of hydrogen is installed as a remaining fuel detector at a portion communicating with the inside of the fuel cell 10. Thereby, the remaining amount of hydrogen in the fuel cell 10 can be monitored while the fuel cell system is stopped. When the sensor 50 detects that the remaining amount of hydrogen is less than an arbitrary set value, the pressure reducing valve 107V as the fuel pressure reducing means is opened, and the hydrogen-containing gas stored in the fuel storage means 40 is reduced through the pipe 107. Then, a hydrogen-containing gas is supplied into the fuel cell 10. At this time, the valve 108V (closed when the fuel cell 10 generates power) is opened, and the hydrogen-containing gas is supplied to the oxidant electrode 1 via the pipe 108. Further, a hydrogen-containing gas is also supplied to the fuel electrode 3 via the pipe 103. When the sensor 50 confirms that a sufficient amount of hydrogen-containing gas has been replenished into the fuel cell 10, the fuel decompression means 107V is closed to stop the replenishment operation.

したがって、この実施の形態では、長期にわたって燃料電池１０の発電を停止した場合でも、燃料電池１０内部の水素残量を監視するとともに、水素残量が少なくなった場合には貯蔵された水素含有ガスを燃料電池１０に供給することで、燃料電池１０の内部を常に還元雰囲気に維持できる。そのため、燃料電池１０の内部は酸化雰囲気にさらされることがないため、長期にわたり燃料電池１０の発電を停止しても電極劣化を抑制できる。   Therefore, in this embodiment, even when power generation of the fuel cell 10 is stopped for a long period of time, the remaining amount of hydrogen in the fuel cell 10 is monitored, and when the remaining amount of hydrogen decreases, the stored hydrogen-containing gas Is supplied to the fuel cell 10 so that the inside of the fuel cell 10 can always be maintained in a reducing atmosphere. Therefore, since the inside of the fuel cell 10 is not exposed to an oxidizing atmosphere, electrode deterioration can be suppressed even if power generation of the fuel cell 10 is stopped for a long time.

なお、燃料昇圧手段３０には、ダイアフラムポンプ、スーパーチャージャなど機械的に昇圧できる手段や、電気化学セルを用いて化学的に昇圧する手段など水素含有ガスを燃料電池１０内部の圧力より高めることができるあらゆる装置を利用できる。また、燃料貯蔵手段４０としては、昇圧した水素含有ガスを高圧のまま保存する高圧ボンベのほか、水素吸蔵合金やカーボンナノチューブ、ボロハイドライドに代表される各種水素化物など水素を吸蔵する材料を充填したタンクのように、水素を高密度に貯蔵することのできるあらゆる装置を利用できる。さらにまた、燃料減圧手段１０７Ｖとしては、一般的なダイアフラム式の減圧弁や電気化学セルなどを利用できるが、万一高圧な水素含有ガスが燃料電池１０に流れ込んだ場合には燃料電池１０が破損する恐れもあるため、燃料電池１０内部と連通する位置に設置した安全弁と組み合わせて使用するのが好ましい。   Note that the fuel boosting means 30 can increase the hydrogen-containing gas from the pressure inside the fuel cell 10 such as a means that can be mechanically boosted such as a diaphragm pump or a supercharger, or a means that chemically boosts using an electrochemical cell. You can use any device you can. The fuel storage means 40 is filled not only with a high-pressure cylinder that stores the pressurized hydrogen-containing gas at a high pressure, but also with hydrogen storage materials such as hydrogen storage alloys, carbon nanotubes, and various hydrides represented by borohydride. Any device that can store hydrogen at high density, such as a tank, can be used. Furthermore, as the fuel pressure reducing means 107V, a general diaphragm type pressure reducing valve, an electrochemical cell, or the like can be used. However, if a high-pressure hydrogen-containing gas flows into the fuel cell 10, the fuel cell 10 is damaged. Therefore, it is preferably used in combination with a safety valve installed at a position communicating with the inside of the fuel cell 10.

実施の形態２．
図２は、実施の形態２を説明するための燃料電池システムの構成図である。この実施の形態は、実施の形態１の変形例として、燃料昇圧手段が、燃料残量検知器と燃料減圧手段の機能を兼ね備えるものである。燃料昇圧手段３０ａとしては、電解質としてのパーフルオロスルホン酸膜を挟むようにガス拡散電極を配置した電気化学セルを使用した。 Embodiment 2. FIG.
FIG. 2 is a configuration diagram of a fuel cell system for explaining the second embodiment. In this embodiment, as a modification of the first embodiment, the fuel boosting means has the functions of a fuel remaining amount detector and a fuel decompression means. As the fuel pressurizing means 30a, an electrochemical cell having a gas diffusion electrode disposed so as to sandwich a perfluorosulfonic acid film as an electrolyte was used.

電気化学セル３０ａの構成の詳細について述べる。図３は、この実施の形態で使用する電気化学セルの構成図である。固体高分子電解質膜３１、低圧側ガス拡散電極３２、高圧側ガス拡散電極３３、低圧側導電性流路板３４および高圧側導電性流路板３５を、図のように積層して電気化学セル３０ａを得る。低圧側導電性流路板３４は流路溝３４ａとマニホールド３４ｂとを備え、流路溝３４ａはマニホールド３４ｂによって外部と連通している。同様に、高圧側導電性流路板３５は流路溝３５ａとマニホールド３５ｂとを備え、流路溝３５ａはマニホールド３５ｂによって外部と連通している。すなわち、高圧側ガス拡散電極３３が燃料貯蔵手段４０と連通し、低圧側ガス拡散電極３２が燃料電池１０と連通することなる。   Details of the configuration of the electrochemical cell 30a will be described. FIG. 3 is a configuration diagram of an electrochemical cell used in this embodiment. An electrochemical cell comprising a solid polymer electrolyte membrane 31, a low-pressure side gas diffusion electrode 32, a high-pressure side gas diffusion electrode 33, a low-pressure side conductive channel plate 34 and a high-pressure side conductive channel plate 35, as shown in the figure. 30a is obtained. The low-pressure side conductive flow path plate 34 includes a flow path groove 34a and a manifold 34b, and the flow path groove 34a communicates with the outside through the manifold 34b. Similarly, the high-voltage side conductive flow path plate 35 includes a flow path groove 35a and a manifold 35b, and the flow path groove 35a communicates with the outside through the manifold 35b. That is, the high pressure side gas diffusion electrode 33 communicates with the fuel storage means 40, and the low pressure side gas diffusion electrode 32 communicates with the fuel cell 10.

この電気化学セル３０ａの高圧側ガス拡散電極３３と低圧側ガス拡散電極３２とを、直流電源３６を経由して電気的に接続する。直流電源３６の正極は低圧側ガス拡散電極３２側に、同じく負極は高圧側ガス拡散電極３３に接続されるので、高圧側ガス拡散電極３３から直流電源３６を経由して低圧側ガス拡散電極３２に電流が流れるように、直流電力が供給される。このように直流電力を供給することで、次のような電気化学反応を生じ、水素含有ガス中の水素を昇圧することができる。
低圧側反応（ａｎｏｄｅ）：Ｈ２（低圧）→２Ｈ＋＋２ｅ−
高圧側反応（Ｃａｔｈｏｄｅ）：２Ｈ＋＋２ｅ−→Ｈ２（高圧）
昇圧できる圧力は、理論的には次のネルンストの式に従い、電気化学セル３０ａに印加する直流電圧に依存する。
Ｅ＝ＲＴ／２Ｆ×ｌｎ（ＰＨ２，Ｃａｔｈｏｄｅ／ＰＨ２，ａｎｏｄｅ）
ここで、Ｅは直流電圧、Ｒは気体定数、Ｔは絶対温度、Ｆはファラデー定数、ＰＨ２は水素分圧を示す。また、２５℃において、上記ネルンストの式は、
Ｅ＝０．０２９６×ｌｏｇ（ＰＨ２，Ｃａｔｈｏｄｅ／ＰＨ２，ａｎｏｄｅ）
となる。これより、２９．６ｍＶの電圧印加でアノードの水素分圧の１０倍、５９ｍＶで１００倍まで、理論的には昇圧可能なことがわかる。ただし、電気化学セル３０ａの耐圧にも限界があり、それによって昇圧できる圧力は制限される。よって、水素の昇圧圧力を調整するために、直流電源３６の電圧を調整する必要があり、電圧調整手段は適宜選択できる。 The high pressure side gas diffusion electrode 33 and the low pressure side gas diffusion electrode 32 of the electrochemical cell 30 a are electrically connected via a DC power source 36. Since the positive electrode of the DC power source 36 is connected to the low-pressure side gas diffusion electrode 32 side and the negative electrode is connected to the high-pressure side gas diffusion electrode 33, the low-pressure side gas diffusion electrode 32 is connected from the high-pressure side gas diffusion electrode 33 via the DC power source 36. DC power is supplied so that a current flows through By supplying DC power in this way, the following electrochemical reaction can occur, and the hydrogen in the hydrogen-containing gas can be increased.
Low pressure side reaction (anode): H 2 (low pressure) → 2H + + 2e −
High-pressure side reaction (Cathode): 2H + + 2e − → H 2 (high pressure)
The pressure that can be boosted theoretically depends on the DC voltage applied to the electrochemical cell 30a according to the following Nernst equation.
E = RT / 2F × ln ( PH2, Cathode / PH2, anode )
Here, E is a DC voltage, R is a gas constant, T is an absolute temperature, F is a Faraday constant, and P H2 is a hydrogen partial pressure. Also, at 25 ° C., the Nernst equation is
E = 0.0296 × log (P H2, Cathode / P H2, anode )
It becomes. This shows that the voltage can be increased theoretically to 10 times the hydrogen partial pressure of the anode by applying a voltage of 29.6 mV and to 100 times at 59 mV. However, there is a limit to the withstand voltage of the electrochemical cell 30a, and thereby the pressure that can be increased is limited. Therefore, in order to adjust the boost pressure of hydrogen, it is necessary to adjust the voltage of the DC power source 36, and the voltage adjusting means can be appropriately selected.

つぎに、水素含有ガスを貯蔵する過程の動作について説明する。まず、実施の形態１と同様に燃料電池１０の出力を低下させ、電気化学セル３０ａに排出される水素含有ガスの量は、燃料電池１０の出力が低下した分だけ増加する。出力低下で増加した分の水素含有ガスを、電気化学セル３０ａで昇圧し、燃料貯蔵手段４０に送り貯蔵する。電気化学セル３０ａに供給される直流電力は、外部電源としての直流電源３６の電圧を調整して供給する例を示すが、燃料電池１０の直流電力をＤＣ−ＤＣコンバータなどで電圧変換して供給してもよい。   Next, the operation in the process of storing the hydrogen-containing gas will be described. First, as in the first embodiment, the output of the fuel cell 10 is reduced, and the amount of the hydrogen-containing gas discharged to the electrochemical cell 30a is increased by the amount by which the output of the fuel cell 10 is reduced. The amount of hydrogen-containing gas increased due to the decrease in output is increased in pressure by the electrochemical cell 30a and sent to the fuel storage means 40 for storage. The direct current power supplied to the electrochemical cell 30a is shown by adjusting the voltage of the direct current power source 36 as an external power source. The direct current power of the fuel cell 10 is converted by a DC-DC converter or the like and supplied. May be.

水素含有ガスの貯蔵量は、燃料貯蔵手段４０に取り付けられた圧力センサ４１で監視され、燃料貯蔵手段４０および電気化学セル３０ａの耐圧を超える以前に、水素含有ガスの昇圧を停止する。昇圧停止後は、燃料電池１０の出力を定常発電時の出力まで回復させてもよいし、燃料電池１０の停止動作に移行してもよい。   The storage amount of the hydrogen-containing gas is monitored by a pressure sensor 41 attached to the fuel storage means 40, and the pressure increase of the hydrogen-containing gas is stopped before the pressure resistance of the fuel storage means 40 and the electrochemical cell 30a is exceeded. After stopping the boosting, the output of the fuel cell 10 may be recovered to the output at the time of steady power generation, or the operation may be shifted to the stop operation of the fuel cell 10.

続いて、燃料電池１０の停止動作について説明する。燃料電池１０の停止時には、燃料電池１０の酸化剤電極１に通じるバルブ１１１Ｖおよび１１２Ｖ、さらに燃料電池１０の燃料電極３に通じるバルブ１０２Ｖおよび１０４Ｖが閉じられる。これによって、燃料電池１０の内部は水素含有ガスで満たされており、各バルブにより配管を通じて空気中の酸素が侵入しないようにしている。   Next, the stop operation of the fuel cell 10 will be described. When the fuel cell 10 is stopped, the valves 111V and 112V leading to the oxidant electrode 1 of the fuel cell 10 and the valves 102V and 104V leading to the fuel electrode 3 of the fuel cell 10 are closed. As a result, the inside of the fuel cell 10 is filled with a hydrogen-containing gas, and oxygen in the air is prevented from entering through the piping by each valve.

さらにこの実施の形態では、電気化学セル３０ａが、燃料残量検知器として水素残量を検知するセンサとしても使用される。この電気化学セル３０ａが燃料残量を検知するセンサとしての動作について、図３を用いて説明する。   Furthermore, in this embodiment, the electrochemical cell 30a is also used as a sensor for detecting the remaining amount of hydrogen as a remaining fuel detector. The operation of the electrochemical cell 30a as a sensor for detecting the remaining amount of fuel will be described with reference to FIG.

燃料電池１０の停止状態では、燃料貯蔵手段４０に高圧の水素含有ガスが保存されているため、電気化学セル３０ａの高圧側の電極３３と低圧側の電極３２の間には、ネルンストの式で計算される起電力が発生している。実用的な圧力領域では、その起電力は１００ｍＶ以下である。長期にわたる燃料電池１０の停止によって燃料電池１０内部の水素が消失すると、高圧側と低圧側の水素濃度差が大きくなり、起電力は徐々に大きくなる。起電力が１００ｍＶ以上の任意の設定値を上回った場合、水素残量が少なくなったとして検知できる。ここで、高圧側の電極３３は燃料貯蔵手段４０に連通していることから、基準となる高圧側の水素濃度が安定している。そのため、水素残量を精度よく検知することができる。   Since the high-pressure hydrogen-containing gas is stored in the fuel storage means 40 in the stopped state of the fuel cell 10, the Nernst equation is used between the high-pressure side electrode 33 and the low-pressure side electrode 32 of the electrochemical cell 30a. The calculated electromotive force is generated. In a practical pressure region, the electromotive force is 100 mV or less. When the hydrogen in the fuel cell 10 disappears due to the fuel cell 10 being stopped for a long time, the difference in hydrogen concentration between the high-pressure side and the low-pressure side increases, and the electromotive force gradually increases. When the electromotive force exceeds an arbitrary set value of 100 mV or more, it can be detected that the remaining amount of hydrogen has decreased. Here, since the high-pressure side electrode 33 communicates with the fuel storage means 40, the reference high-pressure side hydrogen concentration is stable. Therefore, the remaining amount of hydrogen can be detected with high accuracy.

また、水素の消失に加えて外部から酸素が侵入すると、低圧側では酸素と水素イオンの間で次の平衡反応が生じる。
２Ｈ＋＋２ｅ−＋１／２Ｏ２＝Ｈ２Ｏ 標準電極電位１．２３Ｖ
その標準電極電位は１．２３Ｖと高いため、高圧側の電極３３と低圧側の電極３２との間には１００ｍＶを大きく上回る起電力を生じる。酸素の侵入による起電力の上昇は急峻な立ち上がりを見せるので、速やかに酸素の侵入を検知できる。なお、燃料電池１０への酸素侵入に対して電気化学セル３０ａによる酸素侵入検知が遅延しないように、配管１０３、１０８を適宜選択しておく。 Further, when oxygen enters from the outside in addition to disappearance of hydrogen, the following equilibrium reaction occurs between oxygen and hydrogen ions on the low pressure side.
2H + + 2e − + 1 / 2O 2 = H 2 O Standard electrode potential 1.23V
Since the standard electrode potential is as high as 1.23 V, an electromotive force greatly exceeding 100 mV is generated between the high-voltage side electrode 33 and the low-voltage side electrode 32. Since the increase in electromotive force due to the intrusion of oxygen shows a steep rise, the intrusion of oxygen can be detected quickly. The pipes 103 and 108 are appropriately selected so that oxygen intrusion detection by the electrochemical cell 30a is not delayed with respect to oxygen intrusion into the fuel cell 10.

このように、電気化学セル３０ａを用いて高圧側の電極３３と低圧側の電極３２の起電力を監視することで、燃料電池１０内部の水素残量を精度よく検知することができる。さらに、燃料電池１０内部へ酸素が侵入した場合も速やかに検知できる。水素残量が少なくなったことを検知した場合および酸素侵入を検知した場合は、燃料貯蔵手段４０に蓄えた高圧の水素含有ガスを減圧して燃料電池１０に送り込み補充することで、燃料電池１０内を還元雰囲気に保つことができる。   Thus, by monitoring the electromotive force of the high-voltage electrode 33 and the low-voltage electrode 32 using the electrochemical cell 30a, the remaining amount of hydrogen in the fuel cell 10 can be detected with high accuracy. Furthermore, it is possible to quickly detect when oxygen enters the fuel cell 10. When it is detected that the remaining amount of hydrogen has decreased and when oxygen intrusion is detected, the high-pressure hydrogen-containing gas stored in the fuel storage means 40 is reduced in pressure and sent to the fuel cell 10 for replenishment. The inside can be maintained in a reducing atmosphere.

ここで、電気化学セル３０ａは、燃料貯蔵手段４０に蓄えた高圧の水素含有ガスを減圧して燃料電池１０に送り込むための燃料減圧手段としても使用される。減圧は基本的に昇圧の逆動作を行なう。つまり昇圧の場合と逆の電流、つまり低圧側ガス拡散電極３２から高圧側ガス拡散電極３３に電流を流せば、高圧側ガス拡散電極３３において水素を水素イオンと電子に分解し、低圧側ガス拡散電極３２において水素イオンと電子とが再結合して水素が生成される。すなわち、水素は高圧側ガス拡散電極３３から低圧側ガス拡散電極３２に移動する。開回路の状態では、高圧側ガス拡散電極３３より低圧側ガス拡散電極３２の方が電位は高いため、両極を電気的に導通させるだけで、電流は低圧側ガス拡散電極３２から高圧側ガス拡散電極３３に電流が流れ、高圧側ガス拡散電極３３から低圧側ガス拡散電極３２に水素を移動させることができる。   Here, the electrochemical cell 30 a is also used as a fuel decompression means for decompressing and feeding the high-pressure hydrogen-containing gas stored in the fuel storage means 40 to the fuel cell 10. Decompression basically performs the reverse operation of boosting. In other words, if a current opposite to that in the case of boosting, that is, a current is passed from the low pressure side gas diffusion electrode 32 to the high pressure side gas diffusion electrode 33, hydrogen is decomposed into hydrogen ions and electrons in the high pressure side gas diffusion electrode 33, Hydrogen ions and electrons recombine at the electrode 32 to generate hydrogen. That is, hydrogen moves from the high pressure side gas diffusion electrode 33 to the low pressure side gas diffusion electrode 32. In the open circuit state, since the potential of the low-pressure side gas diffusion electrode 32 is higher than that of the high-pressure side gas diffusion electrode 33, the current is passed from the low-pressure side gas diffusion electrode 32 only by electrically connecting both electrodes. A current flows through the electrode 33, and hydrogen can be moved from the high-pressure side gas diffusion electrode 33 to the low-pressure side gas diffusion electrode 32.

図３を用いて具体的に説明する。まず、直流電源３６と高圧側ガス拡散電極３３との間のスイッチを切り換え、低圧側ガス拡散電極３２から可変抵抗３７を経由して高圧側ガス拡散電極３３に電流が流れるように回路を形成する。ここで、高圧側ガス拡散電極３３と低圧側ガス拡散電極３２とを完全に短絡してしまうと、高圧側と低圧側が同じ水素分圧になるまで水素が移動してしまう。そのため、可変抵抗３７を用いて電流量あるいは高圧側と低圧側の電位差を制御することにより、低圧側の異常加圧を防止することができる。さらに、可変抵抗３７の代用として逆バイアスの直流電源を用いてもよい。   This will be specifically described with reference to FIG. First, the switch between the DC power source 36 and the high-pressure side gas diffusion electrode 33 is switched, and a circuit is formed so that a current flows from the low-pressure side gas diffusion electrode 32 to the high-pressure side gas diffusion electrode 33 via the variable resistor 37. . Here, if the high-pressure side gas diffusion electrode 33 and the low-pressure side gas diffusion electrode 32 are completely short-circuited, hydrogen moves until the high-pressure side and the low-pressure side have the same hydrogen partial pressure. Therefore, by controlling the amount of current or the potential difference between the high voltage side and the low voltage side using the variable resistor 37, abnormal pressurization on the low voltage side can be prevented. Further, a reverse bias DC power supply may be used as a substitute for the variable resistor 37.

このように、この実施の形態では、長期にわたり燃料電池１０の発電を停止しても電極劣化を抑制できることに加えて、電気化学セル３０ａが燃料昇圧手段、燃料残量検知器、燃料減圧手段として機能するため、省スペース化を図ることができる。また、燃料残量検知器として電気化学セル３０ａを用いることによって、燃料電池１０内部の水素残量を精度よく検知することができるとともに、燃料電池１０内部へ酸素が侵入した場合も速やかに検知できる。さらに、燃料減圧手段として電気化学セル３０ａを用いることによって、燃料昇圧手段の逆動作を行なうだけで、燃料貯蔵手段４０に蓄えた高圧の水素含有ガスを減圧して燃料電池１０に送り込み補充できる。   Thus, in this embodiment, in addition to being able to suppress electrode deterioration even if power generation of the fuel cell 10 is stopped for a long period of time, the electrochemical cell 30a serves as a fuel boosting means, a fuel remaining amount detector, and a fuel decompressing means. Since it functions, space can be saved. In addition, by using the electrochemical cell 30a as a fuel remaining amount detector, the remaining amount of hydrogen in the fuel cell 10 can be detected with high accuracy, and even when oxygen enters the fuel cell 10 can be detected quickly. . Furthermore, by using the electrochemical cell 30a as the fuel decompression means, the high-pressure hydrogen-containing gas stored in the fuel storage means 40 can be decompressed and sent to the fuel cell 10 simply by performing the reverse operation of the fuel boosting means.

実施の形態１を説明するための燃料電池システムの構成図である。1 is a configuration diagram of a fuel cell system for explaining Embodiment 1. FIG. 実施の形態２を説明するための燃料電池システムの構成図である。FIG. 3 is a configuration diagram of a fuel cell system for explaining a second embodiment. 実施の形態２を説明するための電気化学セルの構成図である。FIG. 5 is a configuration diagram of an electrochemical cell for explaining a second embodiment.

符号の説明Explanation of symbols

１ 酸化剤電極、２ 電解質、３ 燃料電極、１０ 燃料電池、２０ 改質器、３０、３０ａ 燃料昇圧手段、 ３１ 電解質膜、３２ 低圧側ガス拡散電極、３３ 高圧側ガス拡散電極、３６ 直流電源、３７ 可変抵抗、４０ 燃料貯蔵手段、５０ 燃料残量検知器、１０７ｖ 燃料減圧手段
DESCRIPTION OF SYMBOLS 1 Oxidizer electrode, 2 Electrolyte, 3 Fuel electrode, 10 Fuel cell, 20 Reformer, 30, 30a Fuel pressure | voltage rise means, 31 Electrolyte membrane, 32 Low pressure side gas diffusion electrode, 33 High pressure side gas diffusion electrode, 36 DC power supply, 37 Variable resistance, 40 Fuel storage means, 50 Fuel remaining amount detector, 107v Fuel decompression means

Claims (6)

酸化剤が供給される酸化剤電極と燃料が供給される燃料電極とで電解質膜を狭持した燃料電池と、前記燃料電池に前記燃料を供給するための改質器と、前記燃料の一部を昇圧するための燃料昇圧手段と、前記燃料昇圧手段によって昇圧された前記燃料を貯蔵するための燃料貯蔵手段と、前記燃料電池内の燃料残量を検知するための燃料残量検知器と、前記燃料貯蔵手段に貯蔵された前記燃料を減圧して前記燃料電池に供給するための燃料減圧手段とを備え、
前記燃料電池の発電停止状態で、前記燃料残量検知器が前記燃料電池内の前記燃料残量が所定値より少なくなったと検知した場合に、前記燃料貯蔵手段に貯蔵された前記燃料を前記燃料減圧手段によって前記燃料電池に補充することを特徴とする燃料電池システム。 A fuel cell having an electrolyte membrane sandwiched between an oxidant electrode supplied with an oxidant and a fuel electrode supplied with fuel, a reformer for supplying the fuel to the fuel cell, and a part of the fuel A fuel boosting means for boosting the fuel, a fuel storage means for storing the fuel boosted by the fuel boosting means, a fuel remaining amount detector for detecting the remaining amount of fuel in the fuel cell, Fuel decompression means for decompressing and supplying the fuel stored in the fuel storage means to the fuel cell;
When the fuel remaining amount detector detects that the remaining amount of fuel in the fuel cell is less than a predetermined value in the fuel cell power generation stop state, the fuel stored in the fuel storage means is used as the fuel. A fuel cell system, wherein the fuel cell is replenished by decompression means. 燃料残量検知器は、高圧側ガス拡散電極と低圧側ガス拡散電極とで電解質膜を挟持し、前記高圧側ガス拡散電極と前記低圧側ガス拡散電極との間の起電力を検出する電気化学セルであって、前記高圧側ガス拡散電極が燃料貯蔵手段と連通していることを特徴とする請求項１記載の燃料電池システム。   The fuel remaining amount detector is an electrochemical device that sandwiches an electrolyte membrane between a high pressure side gas diffusion electrode and a low pressure side gas diffusion electrode, and detects an electromotive force between the high pressure side gas diffusion electrode and the low pressure side gas diffusion electrode. 2. The fuel cell system according to claim 1, wherein the high-pressure side gas diffusion electrode is a cell and communicates with a fuel storage means. 燃料残量検知器は、高圧側ガス拡散電極と低圧側ガス拡散電極とで電解質膜を挟持し、前記高圧側ガス拡散電極と前記低圧側ガス拡散電極との間の起電力を検出する電気化学セルであって、前記低圧側ガス拡散電極が燃料電池と連通していることを特徴とする請求項１または２記載の燃料電池システム。   The fuel remaining amount detector is an electrochemical device that sandwiches an electrolyte membrane between a high pressure side gas diffusion electrode and a low pressure side gas diffusion electrode, and detects an electromotive force between the high pressure side gas diffusion electrode and the low pressure side gas diffusion electrode. 3. The fuel cell system according to claim 1, wherein the low-pressure gas diffusion electrode is in communication with a fuel cell. 燃料昇圧手段は、高圧側ガス拡散電極と低圧側ガス拡散電極とで電解質膜を挟持し、前記高圧側ガス拡散電極と前記低圧側ガス拡散電極とを電気的に接続した際にこの接続を経由して前記高圧側ガス拡散電極から前記低圧側ガス拡散電極に電流が流れるように直流電力を供給された場合に、前記低圧側ガス拡散電極において燃料をイオンと電子に分解し、前記高圧側ガス拡散電極において前記イオンと前記電子とを再結合した際に前記燃料を昇圧できる電気化学セルであることを特徴とする請求項１記載の燃料電池システム。   The fuel boosting means sandwiches the electrolyte membrane between the high-pressure side gas diffusion electrode and the low-pressure side gas diffusion electrode, and passes through this connection when the high-pressure side gas diffusion electrode and the low-pressure side gas diffusion electrode are electrically connected. When the DC power is supplied so that a current flows from the high pressure side gas diffusion electrode to the low pressure side gas diffusion electrode, the fuel is decomposed into ions and electrons in the low pressure side gas diffusion electrode, and the high pressure side gas is The fuel cell system according to claim 1, wherein the fuel cell system is an electrochemical cell capable of boosting the fuel when the ions and the electrons are recombined in a diffusion electrode. 燃料減圧手段は、高圧側ガス拡散電極と低圧側ガス拡散電極とで電解質膜を挟持し、前記高圧側ガス拡散電極と前記低圧側ガス拡散電極とを電気的に接続した際にこの接続を経由して前記低圧側ガス拡散電極から前記高圧側ガス拡散電極に電流が流れるように回路形成された場合に、前記高圧側ガス拡散電極において燃料をイオンと電子に分解し、前記低圧側ガス拡散電極において前記イオンと前記電子とを再結合した際に前記燃料を減圧できる電気化学セルであることを特徴とする請求項１記載の燃料電池システム。   The fuel pressure reducing means sandwiches the electrolyte membrane between the high-pressure side gas diffusion electrode and the low-pressure side gas diffusion electrode, and passes through this connection when the high-pressure side gas diffusion electrode and the low-pressure side gas diffusion electrode are electrically connected. When the circuit is formed so that a current flows from the low pressure side gas diffusion electrode to the high pressure side gas diffusion electrode, the high pressure side gas diffusion electrode decomposes fuel into ions and electrons, and the low pressure side gas diffusion electrode The fuel cell system according to claim 1, wherein the fuel cell system is an electrochemical cell capable of decompressing the fuel when the ions and the electrons are recombined. 燃料昇圧手段と燃料検知器と燃料減圧手段とが一体化された電気化学セルを備え、前記電気化学セルは、高圧側ガス拡散電極と低圧側ガス拡散電極とで電解質膜を挟持し、前記高圧側ガス拡散電極が燃料貯蔵手段と連通し、前記低圧側ガス拡散電極が燃料電池と連通し、前記高圧側ガス拡散電極と前記低圧側ガス拡散電極との間の起電力を検出する電気化学セルであって、前記高圧側ガス拡散電極と前記低圧側ガス拡散電極とを電気的に接続した際にこの接続を経由して前記高圧側ガス拡散電極から前記低圧側ガス拡散電極に電流が流れるように直流電力を供給された場合には、前記低圧側ガス拡散電極において燃料をイオンと電子に分解し、前記高圧側ガス拡散電極において前記イオンと前記電子とを再結合した際に前記燃料を昇圧でき、前記高圧側ガス拡散電極と前記低圧側ガス拡散電極とを電気的に接続した際にこの接続を経由して前記低圧側ガス拡散電極から前記高圧側ガス拡散電極に電流が流れるように回路形成された場合には、前記高圧側ガス拡散電極において前記燃料を前記イオンと前記電子に分解し、前記低圧側ガス拡散電極において前記イオンと前記電子とを再結合した際に前記燃料を減圧できることを特徴とする請求項１記載の燃料電池システム。   An electrochemical cell in which a fuel boosting means, a fuel detector, and a fuel decompression means are integrated, the electrochemical cell sandwiching an electrolyte membrane between a high-pressure side gas diffusion electrode and a low-pressure side gas diffusion electrode, and the high-pressure side An electrochemical cell in which a side gas diffusion electrode communicates with a fuel storage means, the low pressure side gas diffusion electrode communicates with a fuel cell, and an electromotive force is detected between the high pressure side gas diffusion electrode and the low pressure side gas diffusion electrode When the high pressure side gas diffusion electrode and the low pressure side gas diffusion electrode are electrically connected, current flows from the high pressure side gas diffusion electrode to the low pressure side gas diffusion electrode via this connection. Is supplied with DC power, the fuel is decomposed into ions and electrons in the low-pressure side gas diffusion electrode, and the fuel is boosted when the ions and electrons are recombined in the high-pressure side gas diffusion electrode. Can When the high pressure side gas diffusion electrode and the low pressure side gas diffusion electrode are electrically connected, a circuit is formed so that a current flows from the low pressure side gas diffusion electrode to the high pressure side gas diffusion electrode via this connection. The fuel can be decompressed when the fuel is decomposed into the ions and electrons in the high-pressure side gas diffusion electrode, and the ions and electrons are recombined in the low-pressure side gas diffusion electrode. The fuel cell system according to claim 1.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007001798A (en) * 2005-06-22 2007-01-11 Toyota Central Res & Dev Lab Inc Hydrogen fuel-supplying system and fuel cell system
JP2016033496A (en) * 2014-07-31 2016-03-10 株式会社富士技研 Hydrogen concentration detection element

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007001798A (en) * 2005-06-22 2007-01-11 Toyota Central Res & Dev Lab Inc Hydrogen fuel-supplying system and fuel cell system
JP2016033496A (en) * 2014-07-31 2016-03-10 株式会社富士技研 Hydrogen concentration detection element

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