JP2598014B2 - Crossover detection method for stacked fuel cells - Google Patents

Crossover detection method for stacked fuel cells

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Publication number
JP2598014B2
JP2598014B2 JP62079754A JP7975487A JP2598014B2 JP 2598014 B2 JP2598014 B2 JP 2598014B2 JP 62079754 A JP62079754 A JP 62079754A JP 7975487 A JP7975487 A JP 7975487A JP 2598014 B2 JP2598014 B2 JP 2598014B2
Authority
JP
Japan
Prior art keywords
voltage
output voltage
fuel
crossover
fuel cell
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
JP62079754A
Other languages
Japanese (ja)
Other versions
JPS63248074A (en
Inventor
憲朗 光田
正昭 松本
一雄 宇佐見
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
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Publication date
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Publication of JPS63248074A publication Critical patent/JPS63248074A/en
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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • 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

Description

【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、積層型燃料電池のクロスオーバーを検知
する新規な方法に関するものである。Description: TECHNICAL FIELD The present invention relates to a novel method for detecting crossover in a stacked fuel cell.

〔従来の技術〕[Conventional technology]

従来、燃料電池のクロスオーバーの検知方法として第
６図に示すものがあつた。図において、（21）は酸化剤
電極、（22）は電解質マトリツクス、（23）は燃料電極
である。（24），（25），（26），（27）はそれぞれ酸
化剤すなわち空気および燃料ガスの入口および出力を示
す。（28）はガス組成の分析装置でガスクロマトグラフ
などが用いられる。FIG. 6 shows a conventional method for detecting crossover of a fuel cell. In the figure, (21) is an oxidant electrode, (22) is an electrolyte matrix, and (23) is a fuel electrode. (24), (25), (26) and (27) indicate the inlet and output of the oxidant, ie, air and fuel gas, respectively. (28) is a gas composition analyzer using a gas chromatograph or the like.

次に動作について説明する。空気入口（24）、燃料入
口（25）から導入された空気および燃料ガスは、それぞ
れ酸化剤電極（21）および燃料電極（23）の触媒表面
（図示せず）に達し、電気化学反応を起こすことによ
り、図中矢印Ａで示すように燃料電極（23）から酸化剤
（21）へと流れる電流を取り出すことができる。ここ
で、電解質マトリツクス（22）に保持されている電解質
の量が少ない場合、空気あるいは燃料ガスは電解質マト
リツクス（22）中を透過して相手側の電極の触媒表面に
達し反応する。このような現象は一般にクロスオーバー
と呼ばれているが、クロスオーバーを生じた電池のセル
電圧は低下するとともに温度が上昇するため、電解質の
補給などによつてこれを防止する必要がある。Next, the operation will be described. The air and fuel gas introduced from the air inlet (24) and the fuel inlet (25) reach the catalyst surface (not shown) of the oxidizer electrode (21) and the fuel electrode (23), respectively, and cause an electrochemical reaction. As a result, a current flowing from the fuel electrode (23) to the oxidant (21) can be extracted as shown by an arrow A in the figure. Here, when the amount of the electrolyte retained in the electrolyte matrix (22) is small, air or fuel gas permeates through the electrolyte matrix (22) and reaches the catalyst surface of the partner electrode to react. Such a phenomenon is generally called crossover. However, since the cell voltage of the battery in which the crossover has occurred decreases and the temperature increases, it is necessary to prevent this by replenishing the electrolyte or the like.

クロスオーバーが生じているかどうかを判定するため
には、空気出口（26）、燃料出口（27）の部分からガス
を採取し、分析装置（28）でガス組成を分析し、入口側
（24），（25）のガス組成との差から電解質マトリツク
ス（22）中を透過してくるガス量を測定し、クロスオー
バーの有無あるいはその程度を判定する。In order to determine whether or not a crossover has occurred, gas is sampled from the air outlet (26) and fuel outlet (27), and the gas composition is analyzed by the analyzer (28), and the inlet side (24) , (25), the amount of gas passing through the electrolyte matrix (22) is measured, and the presence or absence of the crossover or the degree thereof is determined.

〔発明が解決しようとする問題点〕[Problems to be solved by the invention]

従来のクロスオーバーの検知方法は以上のように構成
されているので、クロスオーバーの原因がシール部にあ
るのか、電解質マトリツクス（22）によるものかの分離
が困難であり、また、分析装置（28）の検出限界の問題
からクロスオーバーの程度が軽い場合や複数個積層され
た場合には判定が困難であるなどの問題点があつた。ま
た積層された多数の燃料電池に対しどれがクロスオーバ
ーを越こしているかを同定することができなかった。Since the conventional crossover detection method is configured as described above, it is difficult to separate whether the cause of the crossover is due to the seal portion or the electrolyte matrix (22). Due to the problem of the detection limit of (1), there is a problem that it is difficult to judge when the degree of crossover is light or when a plurality of layers are stacked. Further, it was not possible to identify which of the stacked fuel cells exceeded the crossover.

またこの他逆負荷をとることでクロスオーバーを判定
する方法が特開昭60-100374号公報に開示されている
が、逆負荷をとるために電池を停止しなければならない
欠点があつた。In addition, a method of determining crossover by applying a reverse load is disclosed in Japanese Patent Application Laid-Open No. 60-100374, but there is a disadvantage that the battery must be stopped in order to obtain the reverse load.

この発明は上記のような問題点を解消する為になされ
たもので、燃料電池の運転中に簡単にクロスオーバーを
検知することのできる方法を提供することを目的とす
る。SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a method capable of easily detecting a crossover during operation of a fuel cell.

〔問題点を解決するための手段〕[Means for solving the problem]

この発明に係る積層型燃料電池のクロスオーバー検知
方法は、積層方向に連続する複数個のセパレータ板につ
いて、セパレータ板の外周部の４隅のうち少なくとも２
隅に積層方向に重なるように電圧端子を取り付け、異な
るセパレータ板間のそれぞれ一方の隅に積層方向に重な
るように取り付けられた電圧端子間の出力電圧Ａを測定
すると共に、上記異なるセパレータ板間のもう一方の隅
に積層方向に重なるように取り付けられた電圧端子間の
出力電圧Ｂを測定し、上記出力電圧Ａと出力電圧Ｂの間
の電圧の増大によりクロスオーバーの発生を検知するよ
うにしたものである。The crossover detection method for a stacked fuel cell according to the present invention may be configured such that, for a plurality of separator plates continuous in the stacking direction, at least two of the four corners of the outer peripheral portion of the separator plate.
Attach voltage terminals so as to overlap in the stacking direction at the corners, measure the output voltage A between the voltage terminals attached so as to overlap in the stacking direction at one corner between different separator plates, and measure the output voltage A between the different separator plates. The output voltage B between the voltage terminals attached to the other corner so as to overlap in the stacking direction is measured, and the occurrence of crossover is detected by the increase in the voltage between the output voltage A and the output voltage B. Things.

〔作用〕[Action]

この発明におけるクロスオーバーの検知方法は、出力
電圧Ａと出力電圧Ｂを測定しているセパレータ板の間に
挟まれた燃料電池またはこれに隣接する燃料電池でクロ
スオーバーが発生すると、クロスオーバーが起こってい
るセルおよびこれに隣接するセルで局部的に電流密度分
布が変化し、このため燃料電池セル面内および積層方向
に電流方向に電流分布の不均一が生じて、出力電圧Ａと
出力電圧Ｂの間の電圧差Ｃが生じる現象を利用して、電
圧差Ｃの大きさをモニタすることで、積層型燃料電池の
動作状態においてもクロスオーバーを検知する。According to the crossover detection method of the present invention, when a crossover occurs in a fuel cell sandwiched between separator plates measuring the output voltage A and the output voltage B or a fuel cell adjacent thereto, the crossover occurs. The current density distribution locally changes in the cell and the cell adjacent thereto, which causes uneven current distribution in the current direction in the plane of the fuel cell and in the stacking direction. By monitoring the magnitude of the voltage difference C using the phenomenon that the voltage difference C occurs, a crossover is detected even in the operating state of the stacked fuel cell.

〔発明の実施例〕(Example of the invention)

以下、この発明の一実施例を図について説明する。第
１図は積層型燃料電池の平面図であり（４）は燃料ガス
の流れを、（５）は酸化剤ガスの流れを示している。
（２），（３）は燃料電池（１）のセパレータ板に取り
付けられたこの発明の方法に用いる電圧端子の位置を示
している。電圧端子（２）は異なるセパレータ板間のそ
れぞれ同じ側に積層方向に異なるように取り付けられた
電圧端子、電圧端子（３）は異なるセパレータ板間のも
う一方の側に積層方向に重なるように取り付けられた電
圧端子であり、この場合、電圧端子（２）はセパレータ
の外周部の燃料ガスおよび酸化剤ガスの供給側の隅に取
り付けられ、電圧端子（３）はセパレータの外周部の燃
料ガスおよび酸化剤ガスの排出側の隅に取り付けられて
いる。セパレータは、一般にカーボンや金属などの導電
体で構成されており、燃料電池（１）の外周部にあって
電解質には触れない位置に相当するので、電圧端子の構
成方法としては、金属製のクリップでセパレータを挟
む、セパレータに孔をあけて金属線を差し込むなど、通
常セル電圧を測定するために用いられている簡単な方法
を適用することができる。第２図は積層型燃料電池の正
面図であり、（11），（12），（13）は積層された状態
における個々の燃料電池である。第２図において、電極
端子a,eは燃料電池（11）とその上部に積層された燃料
電池との間に配設されたセパレータ板の外周部の燃料ガ
スおよび酸化剤ガスの供給側，および燃料ガスおよび酸
化剤ガスの排出側にそれぞれ取り付けられている。ま
た、電極端子b,fは燃料電池（11）と燃料電池（12）と
の間に配設されたセパレータ板の外周部の燃料ガスおよ
び酸化剤ガスの供給側、および燃料ガスおよび酸化剤ガ
スの排出側にそれぞれ取り付けられている。さらに、電
極端子c,gは燃料電池（12）と燃料電池（13）との間に
配設されたセパレータ板に、電極端子d,hは燃料電池（1
3）とその下部に積層された燃料電池との間に配設され
たセパレータ板に、同様な位置関係で取り付けられてい
る。そして、電極端子ａ〜ｄが積層方向で互いに重なる
位置関係で各セパレータ板に取り付けられ、電極端子ｅ
〜ｈが積層方向で互いに重なる位置関係で各セパレータ
板に取り付けられている。そこで、燃料電池（11）の出
力電圧は、電圧端子ａと電圧端子ｂ間の電圧（出力電圧
ａ−ｂ）および電圧端子ｅと電圧端子ｆ間の電圧（出力
電圧ｅ−ｆ）でモニタできる。また、燃料電池（12）の
出力電圧は、電圧端子ｂと電圧端子ｃ間の電圧（出力電
圧ｂ−ｃ）および電圧端子ｆと電圧端子ｇ間の電圧（出
力電圧ｆ−ｇ）でモニタできる。さらに、燃料電池（1
3）の出力電圧は、電圧端子ｃと電圧端子ｄ間の電圧
（出力電圧ｃ−ｄ）および電圧端子ｇと電圧端子ｈ間の
電圧（出力電圧ｇ−ｈ）でモニタできる。燃料電池が正
常に動作している場合には、燃料電池（11），（12），
（13）の出力電圧は、第２図においてセパレータの左側
の電圧端子（２）で測定した場合とセパレータの右側の
電圧端子（３）で測定した場合とでは、5mV以内の誤差
範囲で完全に一致する。すなわち、出力電圧ａ−ｂと出
力電圧ｅ−ｆ、出力電圧ｂ−ｃと出力電圧ｆ−ｇ、およ
び出力電圧ｃ−ｄと出力電圧ｇ−ｈは燃料電池が正常に
動作している場合には、5mV以内の誤差範囲で完全に一
致する。第１図，第２図のように電圧端子（２），
（３）が設けられたリン酸型燃料電池の出力電圧の経時
変化を第３図に示した。運転条件は190℃、4kg/cm2Ｇ、
200mA/cm2で燃料として水素80体積パーセント、二酸化
炭素20体積パーセントのガスを用い、酸化剤として空気
を用いそれぞれ75％,50％の利用率で運転が行なわれ
た。電極面積は約3600cm2であり積層数は100セルであつ
た。この積層型燃料電池は約1000時間にわたつて運転ば
行なわれたが、この間に同じセルでも電圧端子の位置に
よつて出力電圧が異なるという現象が複数見られた。具
体的には運転時間約400hrにて第３図中矢印（15）に示
す時点より（11）のセルと（13）のセルにおいてａ−ｂ
及びｃ−ｄ間の出力電圧は一定であるのに、ｅ−ｆ及び
ｇ−ｈ間の出力電圧が低下する現象である。電池におい
ては１セルあたりの出力電圧は常に平均化されていて一
定の値になるというのが一般の常識である。発明者ら
は、前記従来の常識と異なる現象が何によるものかを調
べるため、引き続いて連続で運転した。すると、約750h
r経過した図の矢印（16）の時点で今度は（12）のセル
がｂ−c,f−ｇ間の出力電圧共低下をはじめた。そこで
一旦運転を停止して無負荷にした状態での開放電圧を調
べたところ、（12）のセルの開放電圧が900mVまで低下
しており、（12）のセルでクロスオーバーが起こつてい
ることが推定された。この（12）のセルはその後1000hr
まで運転を続けた後、分解しリン酸量が調べられ、その
結果他に比べて（12）のセルのリン酸含有量が著しく少
なく、明らかにクロスオーバーが起こつていたことがわ
かつた。なお、（12）のセルのリン酸含有量が著しく少
なかつた原因については、リン酸含浸時に単純にリン酸
量をミスしていたことが後で判明した。また、セル（1
1），（13）のリン酸含有量は正常な範囲であつた。An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a stacked fuel cell, where (4) shows the flow of fuel gas and (5) shows the flow of oxidant gas.
(2) and (3) show the positions of the voltage terminals used in the method of the present invention, which are mounted on the separator plate of the fuel cell (1). The voltage terminal (2) is mounted on the same side between different separator plates so as to be different in the laminating direction, and the voltage terminal (3) is mounted on the other side between different separator plates so as to overlap in the laminating direction. In this case, the voltage terminal (2) is attached to a corner on the outer peripheral portion of the separator on the supply side of the fuel gas and the oxidizing gas, and the voltage terminal (3) is connected to the fuel gas and the outer peripheral portion of the separator. It is attached to the corner on the oxidant gas discharge side. The separator is generally made of a conductor such as carbon or metal, and corresponds to a position on the outer peripheral portion of the fuel cell (1) that does not come into contact with the electrolyte. A simple method usually used for measuring a cell voltage, such as sandwiching a separator with a clip or inserting a metal wire with a hole in the separator, can be applied. FIG. 2 is a front view of the stacked fuel cell, and (11), (12), and (13) show the individual fuel cells in a stacked state. In FIG. 2, the electrode terminals a and e are connected to the fuel gas and oxidizing gas supply sides of the outer peripheral portion of the separator plate provided between the fuel cell (11) and the fuel cell stacked thereover, and The fuel gas and the oxidizing gas are respectively attached to the discharge side. The electrode terminals b and f are connected to the fuel gas and oxidizing gas supply sides of the outer peripheral portion of the separator plate disposed between the fuel cell (11) and the fuel cell (12), and to the fuel gas and oxidizing gas. Each is attached to the discharge side. Further, the electrode terminals c and g are provided on a separator plate provided between the fuel cell (12) and the fuel cell (13), and the electrode terminals d and h are provided on the fuel cell (1).
A similar positional relationship is attached to a separator plate disposed between 3) and a fuel cell stacked thereunder. Then, the electrode terminals a to d are attached to the respective separator plates in a positional relationship overlapping each other in the laminating direction, and the electrode terminals e are provided.
To h are attached to the respective separator plates in a positional relationship overlapping each other in the stacking direction. Therefore, the output voltage of the fuel cell (11) can be monitored by the voltage between the voltage terminals a and b (output voltage ab) and the voltage between the voltage terminals e and f (output voltage ef). . The output voltage of the fuel cell (12) can be monitored by the voltage between the voltage terminals b and c (output voltage bc) and the voltage between the voltage terminals f and g (output voltage fg). . In addition, fuel cells (1
The output voltage of 3) can be monitored by the voltage between the voltage terminals c and d (output voltage cd) and the voltage between the voltage terminals g and h (output voltage g-h). If the fuel cell is operating normally, the fuel cells (11), (12),
The output voltage of (13) is completely within an error range of 5 mV when measured at the voltage terminal (2) on the left side of the separator in FIG. 2 and when measured at the voltage terminal (3) on the right side of the separator in FIG. Matches. That is, the output voltage ab and the output voltage ef, the output voltage bc and the output voltage fg, and the output voltage cd and the output voltage gh are obtained when the fuel cell is operating normally. Completely match within an error range of 5 mV or less. As shown in FIGS. 1 and 2, the voltage terminals (2),
FIG. 3 shows the change over time of the output voltage of the phosphoric acid fuel cell provided with (3). Operating conditions are 190 ° C, 4kg / cm 2 G,
The operation was performed at 200 mA / cm 2 , using 80% by volume of hydrogen and 20% by volume of carbon dioxide as fuel, and using air as oxidant at 75% and 50% utilization, respectively. The electrode area was about 3600 cm 2 , and the number of layers was 100 cells. This stack type fuel cell was operated for about 1000 hours, and during this time, a plurality of phenomena were observed in which the output voltage was different depending on the position of the voltage terminal even in the same cell. Specifically, at the operation time of about 400 hours, a-b in the cells (11) and (13) from the time point indicated by the arrow (15) in FIG.
And the output voltage between ef and gh decreases while the output voltage between cd and d is constant. It is common general knowledge that in a battery, the output voltage per cell is always averaged and constant. The inventors continued to operate continuously to investigate what caused the phenomenon different from the conventional common sense. Then, about 750h
At the point of the arrow (16) in the figure after the elapse of r, the cell of (12) starts to decrease both the output voltage between bc and fg. Therefore, when the open-circuit voltage in the state where the operation was stopped and no load was applied was examined, the open-circuit voltage of the cell (12) was reduced to 900 mV, and a crossover occurred in the cell (12). Was estimated. This (12) cell is then 1000hr
After the operation was continued, the cell was decomposed and the amount of phosphoric acid was examined. As a result, it was found that the phosphoric acid content of the cell (12) was significantly smaller than that of the other cells, and that crossover had clearly occurred. The cause of the extremely low content of phosphoric acid in the cell (12) was later found out that the amount of phosphoric acid was simply missed during the impregnation with phosphoric acid. The cell (1
The phosphoric acid contents of (1) and (13) were within the normal range.

上記現象を詳しく検討した結果次の様な結論に達し
た。即ち燃料、空気の入口側ほど電池反応が多く起こり
大きな電流が流れ、燃料空気の出口側ほど電流は少ない
ので正常な状態では第４図のように電流が流れる。第４
図中、矢印（６）は入口側に流れる大きな電流、矢印
（７）は出口側に流れる小さな電流を示す。しかしなが
ら第５図のようにクロスオーバーによるローカルな電流
（８）が流れた場合電流の流れる方向は無理に曲げられ
る。すなわちクロスオーバーの起こつているセル（12）
に隣接する上下のセル（11,13）では正常な状態とは異
なる場所で大量の電流が流れる。しかし１セルあたりわ
ずか5mmという薄さと3600cm2という大面積の故に１セル
の面内の電圧が一定という平衡状態に達することができ
ずに入口側（２）における電圧と出口側（３）における
電圧に差異を生ずる。As a result of detailed examination of the above phenomenon, the following conclusions were reached. That is, a large current flows due to a large amount of cell reaction on the fuel and air inlet side, and a large current flows on the fuel and air outlet side, so that the current flows in a normal state as shown in FIG. 4th
In the figure, arrow (6) indicates a large current flowing on the inlet side, and arrow (7) indicates a small current flowing on the outlet side. However, when a local current (8) due to crossover flows as shown in FIG. 5, the direction of the current flow is forcibly bent. That is, the cell where the crossover occurs (12)
In the upper and lower cells (11, 13) adjacent to the, a large amount of current flows in a place different from the normal state. However, because of the thinness of only 5 mm per cell and the large area of 3600 cm 2 , the in-plane voltage of one cell cannot reach an equilibrium state, and the voltage at the inlet side (2) and the voltage at the outlet side (3) Causes a difference.

第５図のローカルな電流（８）は、燃料電池に限らず
起こり得る現象で、従来『局部電池』として腐食の発生
メカニズムの説明に用いられている。ローカルな電流
（８）自身は外に取り出せない電流なので、実測するこ
とができないが、電流が（９）のように局部的に曲げら
れた場合、積層方向ではなく、平面方向の電流が流れる
ためにセパレータの平面方向に電圧差が生じ、これが、
出力電圧の差異すなわち出力ａ−ｂと出力電圧ｅ−ｆ、
出力電圧ｂ−ｃと出力電圧ｆ−ｇ、および出力電圧ｃ−
ｄと出力電圧ｇ−ｈの電圧差につながっていることは理
論的に明らかである。平面方向の電流が流れるのは、ク
ロスオーバーが起こっている燃料電池（12）はなく、こ
れに隣接する上下の燃料電池（11），（13）なので、ま
ず、隣接する上下の燃料電池（11），（13）で電圧端子
位置（２）と電圧端子位置（３）での出力電圧の差が運
転400時間の時点（15）で生じ、さらにクロスオーバー
が著しくなった運転750時間の時点（16）でクロスオー
バーが起こっている燃料電池（12）においても電圧端子
位置（２）と電圧端子位置（３）での出力電圧の差が生
じたと考えられる。The local current (8) in FIG. 5 is a phenomenon that can occur not only in the fuel cell but is conventionally used as a "local cell" to explain the mechanism of occurrence of corrosion. Since the local current (8) itself is a current that cannot be extracted outside, it cannot be measured. However, when the current is locally bent as in (9), a current in a plane direction flows instead of a stacking direction. A voltage difference occurs in the plane direction of the separator,
The difference between the output voltages, that is, the output ab and the output voltage ef,
The output voltage bc, the output voltage fg, and the output voltage c-
It is theoretically clear that the voltage difference between d and the output voltage gh is connected. The current in the planar direction flows through the upper and lower fuel cells (11) and (13), which are adjacent to the upper and lower fuel cells (11) and (13). In (13) and (13), the difference between the output voltage at the voltage terminal position (2) and the output voltage at the voltage terminal position (3) occurs at the time point of operation 400 hours (15), and at the time point of operation time 750 hours when the crossover becomes significant ( It is probable that a difference between the output voltage at the voltage terminal position (2) and the output voltage at the voltage terminal position (3) also occurred in the fuel cell (12) in which crossover occurred in 16).

従って、例えば電圧端子位置（２）と電圧端子位置
（３）で燃料電池（12）の出力電圧ｂ−ｃと出力電圧ｆ
−ｇの電圧差をモニタすることで、電圧差が5mV以上大
きくなった時点で燃料電池（12）のクロスオーバーもし
くは燃料電池（11），（13）のクロスオーバーの発生を
検知することができる。そこで、すべての燃料電池につ
いて電圧端子位置（２）と電圧端子位置（３）での出力
電圧を測定しなくても、数セルおきに電圧端子位置
（２）と電圧端子位置（３）での出力電圧を測定すれ
ば、クロスオーバーの発生の検知が可能である。さらに
１つの燃料電池の出力電圧ではなく、数セルの出力電圧
例えば、第１図の出力電圧ａ−ｄと出力電圧ｅ−ｈの電
圧差を測定してもクロスオーバーの発生の検知が可能で
ある。Therefore, for example, at the voltage terminal position (2) and the voltage terminal position (3), the output voltage bc and the output voltage f of the fuel cell (12) are output.
By monitoring the voltage difference of −g, the occurrence of the crossover of the fuel cell (12) or the crossover of the fuel cells (11) and (13) can be detected when the voltage difference increases by 5 mV or more. . Therefore, without measuring the output voltage at the voltage terminal positions (2) and (3) for all the fuel cells, the voltage at the voltage terminal positions (2) and (3) is determined every few cells. By measuring the output voltage, the occurrence of crossover can be detected. Further, the occurrence of crossover can be detected by measuring not only the output voltage of one fuel cell but also the output voltage of several cells, for example, the voltage difference between the output voltages ad and eh in FIG. is there.

本発明者らは上記新たな知見に基づいて鋭意検討を重
ねた結果、本発明を完成するに至つたものである。The present inventors have conducted intensive studies based on the above-mentioned new findings, and as a result, have completed the present invention.

本発明によればクロスオーバーが発生したセルにおい
て、その出力電圧が低下する100時間以上手前で検知す
ることができ、リン酸の補給が自動化されている場合に
は、運転を行ないながらリン酸補給を行ないリン酸の補
給が自動化されていない場合にも急に運転を停止する必
要がなく充分な準備期間を得て運転を停止し手動で補給
することができる。According to the present invention, in a cell in which a crossover has occurred, detection can be performed 100 hours or more before the output voltage of the cell decreases, and when replenishment of phosphoric acid is automated, phosphoric acid replenishment is performed while driving. When the replenishment of phosphoric acid is not automated, the operation does not need to be suddenly stopped, and a sufficient preparation period can be obtained to stop the operation and supply manually.

電圧を検知する電極端子を取り付ける場所としては、
セパレータ板の外周部の４隅がそれぞれ燃料ガスおよび
酸化ガスの少なくとも一方の入口側あるいは出口側に位
置することから、セパレータ板の外周部の少なくとも２
隅に取り付ければよいが、特に第１図のように電流密度
分布の大きく異なる位置（即ち、燃料ガス、酸化ガスの
両者の入口側と出口側とのセパレータ板の２隅）の方が
電圧差が大きくなるので望ましい。As a place to attach the electrode terminal that detects voltage,
Since the four corners of the outer peripheral portion of the separator plate are respectively located on the inlet side or the outlet side of at least one of the fuel gas and the oxidizing gas, at least two corners of the outer peripheral portion of the separator plate are provided.
In particular, as shown in FIG. 1, the voltage difference may be larger at positions where the current density distribution is significantly different (that is, at two corners of the separator plate between the inlet side and the outlet side of both the fuel gas and the oxidizing gas) as shown in FIG. Is desirable because it becomes large.

また積層燃料電池全体が初期同程度の電解液を含んで
いればマトリツクスの電解液の枯渇によるクロスオーバ
ーの発生はほぼ同時期と予想されるから、本発明の判定
方法をいくつかのセルに適用しておけば全体について判
定することができる。Also, if the entire fuel cell stack contains the same amount of electrolyte at the initial stage, the crossover due to the depletion of the electrolyte in the matrix is expected to occur at about the same time, so the determination method of the present invention is applied to some cells. If so, it can be determined for the whole.

なお、上記実施例では、リン酸型燃料電池について示
したが、説明したが必ずしもこれに限定されず例えば溶
融炭酸塩型、アルカリ型などにも適用できる。In the above embodiment, the phosphoric acid type fuel cell is described, but the description has been made, but the present invention is not limited to this. For example, the present invention can be applied to a molten carbonate type, an alkaline type and the like.

〔発明の効果〕 以上のように、この発明によれば、積層方向に連続す
る複数個のセパレータ板について、セパレータ板の外周
部の４隅のうち少なくとも２隅に積層方向に重なるよう
に電圧端子を取り付け、異なるセパレータ板間のそれぞ
れ一方の隅に積層方向に重なるように取り付けられた電
圧端子間の出力電圧Ａを測定すると共に、上記異なるセ
パレータ板間のもう一方の隅に積層方向に重なるように
取り付けられた電圧端子間の出力電圧Ｂを測定し、上記
出力電圧Ａと出力電圧Ｂの間の電圧差Ｃの電圧の増大に
よりクロスオーバーの発生を検知するようにしたので、
電池の運転中においても簡単に検知することができると
いう効果がある。[Effects of the Invention] As described above, according to the present invention, for a plurality of separator plates continuous in the laminating direction, the voltage terminals are arranged so as to overlap in the laminating direction at least two of the four corners of the outer peripheral portion of the separator plate. And measure the output voltage A between the voltage terminals attached so as to overlap in the laminating direction at one corner between the different separator plates, and to overlap the other corner between the different separator plates in the laminating direction. Since the output voltage B between the voltage terminals attached to is measured, and the occurrence of the crossover is detected by the increase of the voltage difference C between the output voltage A and the output voltage B,
There is an effect that detection can be easily performed even during operation of the battery.

【図面の簡単な説明】[Brief description of the drawings]

第１図はこの発明の一実施例に用いる積層型燃料電池の
要部を示す平面図、第２図は第１図のものの正面図、第
３図は本発明の一実施例によるクロスオーバーの検知を
説明するための出力電圧の経時変化を示す特性図、第４
図は正常な状態における電流の流れを説明する図、第５
図は積層型電池の一部にクロスオーバーが発生した場合
における電流の流れを説明する図、第６図は従来方法を
示す構成図である。 図において、（１），（11），（12），（13）は燃料電
池、（２），（３）は出力電圧測定端子を示す。 なお、各図中同一符号は同一もしくは相当部分を示すも
のとする。FIG. 1 is a plan view showing a main part of a stacked fuel cell used in one embodiment of the present invention, FIG. 2 is a front view of the fuel cell shown in FIG. 1, and FIG. FIG. 4 is a characteristic diagram showing a change with time of the output voltage for explaining detection;
FIG. 5 is a diagram for explaining a current flow in a normal state;
FIG. 6 is a diagram for explaining a current flow when a crossover occurs in a part of the stacked battery, and FIG. 6 is a configuration diagram showing a conventional method. In the figure, (1), (11), (12) and (13) indicate fuel cells, and (2) and (3) indicate output voltage measuring terminals. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】燃料電極と酸化剤電極を電解質マトリック
スを介して対向させ上記燃料および酸化剤電極にそれぞ
れ燃料および酸化剤ガスを供給して発電を行なう燃料電
池をセパレータ板を介して複数個積層した積層型燃料電
池において、積層方向に連続する複数個のセパレータ板
について、セパレータ板の外周部の４隅のうち少なくと
も２隅に積層方向に重なるように電圧端子を取り付け、
異なるセパレータ板間のそれぞれ一方の隅に積層方向に
重なるように取り付けられた電圧端子間の出力電圧Ａを
測定すると共に、上記異なるセパレータ板間のもう一方
の隅に積層方向に重なるように取り付けられた電圧端子
間の出力電圧Ｂを測定し、上記出力電圧Ａと出力電圧Ｂ
の間の電圧差Ｃの電圧の増大によりクロスオーバーの発
生を検知することを特徴とする積層型燃料電池のクロス
オーバー検知方法。1. A fuel cell in which a fuel electrode and an oxidant electrode are opposed to each other with an electrolyte matrix therebetween and a fuel and an oxidant gas are supplied to the fuel and the oxidant electrode to generate electric power, and a plurality of fuel cells are stacked via a separator plate. In the stacked fuel cell, for a plurality of separator plates continuous in the stacking direction, voltage terminals are attached to at least two of the four corners of the outer peripheral portion of the separator plate so as to overlap in the stacking direction,
While measuring the output voltage A between the voltage terminals attached to one corner between the different separator plates so as to overlap in the stacking direction, it is attached so as to overlap the other corner between the different separator plates in the stack direction. The output voltage B between the voltage terminals is measured, and the output voltage A and the output voltage B are measured.
Detecting the occurrence of crossover by increasing the voltage of the voltage difference C between the two. 【請求項２】上記出力電圧Ａを測定する電圧端子は、上
記セパレータ板の外周部の４隅のうち燃料および酸化剤
ガスの供給部の両方に近い隅に配置し、上記出力電圧Ｂ
を測定する電圧端子は、上記セパレータ板の外周部の４
隅のうち燃料および酸化剤ガスの供給部の両方から遠い
隅に配置したことを特徴とする特許請求の範囲第１項記
載の積層型燃料電池のクロスオーバー検知方法。2. A voltage terminal for measuring the output voltage A is disposed at one of four corners of an outer peripheral portion of the separator plate which is close to both a fuel and oxidant gas supply portion.
Is measured at the outer peripheral portion of the separator plate.
2. The crossover detection method for a stacked fuel cell according to claim 1, wherein the corners are located at corners far from both the fuel and oxidant gas supply sections.
JP62079754A 1987-04-02 1987-04-02 Crossover detection method for stacked fuel cells Expired - Lifetime JP2598014B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62079754A JP2598014B2 (en) 1987-04-02 1987-04-02 Crossover detection method for stacked fuel cells

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62079754A JP2598014B2 (en) 1987-04-02 1987-04-02 Crossover detection method for stacked fuel cells

Publications (2)

Publication Number Publication Date
JPS63248074A JPS63248074A (en) 1988-10-14
JP2598014B2 true JP2598014B2 (en) 1997-04-09

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5085949A (en) * 1991-02-05 1992-02-04 Kabushiki Kaisha Toshiba Fuel cell generation system
US6638650B1 (en) * 2000-09-29 2003-10-28 Ballard Power Systems Inc. Method and apparatus for detecting transfer leaks in fuel cells and fuel cell stacks
JP2007018745A (en) * 2005-07-05 2007-01-25 Toyota Motor Corp Fuel cell system
US20090246570A1 (en) * 2006-03-28 2009-10-01 Takayuki Hirashige Method and apparatus for measuring crossover loss of fuel cell
US9065126B2 (en) 2008-07-09 2015-06-23 Audi Ag Fuel cell stack conditioned to operate safely with failed cells
WO2010073962A1 (en) * 2008-12-26 2010-07-01 株式会社 東芝 Fuel cell system and fuel cell

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* Cited by examiner, † Cited by third party
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JPS61264683A (en) * 1985-05-17 1986-11-22 Fuji Electric Co Ltd Measuring device for current distribution at electrode part of fuel cell

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