JPH0837014A

JPH0837014A - Phosphoric acid type fuel cell power plant and method of maintaining the same

Info

Publication number: JPH0837014A
Application number: JP6173840A
Authority: JP
Inventors: Katsunori Sakai; 勝則酒井; Tadahiko Taniguchi; 忠彦谷口
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 1994-07-26
Filing date: 1994-07-26
Publication date: 1996-02-06

Abstract

PURPOSE:To suppress movement of phosphoric acid within the body of a fuel cell under storage and maintain the cell performance stably by supplying a dry inert gas to a fuel electrode and oxidator electrode while the power generation is at a standstill. CONSTITUTION:While the power generating plat of a phosphoric acid type fuel cell is at a standstill, an anode inlet shutoff valve 28 and cathode inlet shutoff valve 29 furnished at the inlets to an anode electrode and a cathode electrode are fully closed. Open signal is given to dry inert gas supply control valves 22, 23 situated downstream of the valves 28, 29, and a dry inert gas is supplied to the anode electrode and cathode electrode continuously or intermittently. This constitution enables maintaining the anode electrode and cathode electrode in a dry inert gas atmosphere so that the external air is prevented from intruding into the body of the fuel cell. Accordingly the electrode potential and phosphoric acid volume of the cell body while the power generation is at a standstill can be controlled to specified values, and it is possible to maintain the cell performance stably without risk of dropping even if it is stored for a long period of time.

Description

Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、リン酸型燃料電池発電
プラントおよびその保管方法に係り、特にリン酸型燃料
電池発電プラントの発電運転（以下、単に運転と称す
る）停止中の電池保管状態における燃料電池本体の触媒
の劣化防止手段に改良を施したリン酸型燃料電池発電プ
ラントに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphoric acid fuel cell power plant and a storage method thereof, and more particularly to a battery storage state during a power generation operation (hereinafter, simply referred to as "operation") of a phosphoric acid fuel cell power plant. The present invention relates to a phosphoric acid fuel cell power plant in which the means for preventing deterioration of the catalyst of the fuel cell main body is improved.

【０００２】[0002]

【従来の技術】従来から、石炭や石油等のような燃料が
有している化学エネルギーを、等温の下で連続的に直接
電気エネルギーに変換する装置として、燃料電池が知ら
れている。この燃料電池は、通常、電解質を保有する電
解質層（以下、マトリックス層と称する）を一対の多孔
質電極で挟んで、一方の電極の背面に水素等の燃料ガス
を接触させると共に、他方の電極の背面に空気等の酸化
剤を接触させて、この時に起こる電気化学反応により生
じる電気エネルギーを、上記各電極間から取り出すよう
にしたものである。2. Description of the Related Art Conventionally, a fuel cell has been known as a device for directly converting the chemical energy of a fuel such as coal or petroleum into an electrical energy directly under isothermal conditions. In this fuel cell, an electrolyte layer containing an electrolyte (hereinafter referred to as a matrix layer) is usually sandwiched between a pair of porous electrodes, and a fuel gas such as hydrogen is brought into contact with the back surface of one electrode while the other electrode is contacted. An oxidant such as air is brought into contact with the back surface of the electrode, and the electric energy generated by the electrochemical reaction occurring at this time is taken out from between the electrodes.

【０００３】この場合、燃料ガスとしては、水素または
天然ガスを改良して得られる改質ガスが用いられ、酸化
剤としては、空気または酸素が用いられる。また、電解
質としては、溶融炭酸塩、アルカリ溶液、酸性溶液、固
体高分子、固体酸化物等が用いられるが、最近では、リ
ン酸を電解質としたリン酸型燃料電池が注目されてきて
いる。In this case, hydrogen or a reformed gas obtained by improving natural gas is used as the fuel gas, and air or oxygen is used as the oxidant. As the electrolyte, a molten carbonate, an alkaline solution, an acidic solution, a solid polymer, a solid oxide, or the like is used. Recently, a phosphoric acid fuel cell using phosphoric acid as an electrolyte has been attracting attention.

【０００４】この種のリン酸型燃料電池は、図４に分解
斜視図を示すように、電解質であるリン酸を含浸させた
マトリックス層１ｃを挟んで、一対の多孔質電極１ａ，
１ｂを配置し、一方の多孔質電極である燃料極（以下、
アノード電極と称する）１ａの背面に水素等の燃料ガス
を接触させると共に、他方の多孔質電極である酸化剤極
（以下、カソード電極と称する）１ｂの背面に酸素等の
酸化剤を接触させ、この時に起こる電気化学反応を利用
して、上記各電極１ａ，１ｂ間から電気エネルギーを取
り出している。In this type of phosphoric acid fuel cell, as shown in the exploded perspective view of FIG. 4, a pair of porous electrodes 1a, 1a, 1c sandwiching a matrix layer 1c impregnated with phosphoric acid which is an electrolyte,
1b is arranged and one of the porous electrodes is a fuel electrode (hereinafter,
A fuel gas such as hydrogen is brought into contact with the back surface of the anode electrode) 1a, and an oxidant such as oxygen is brought into contact with the back surface of the oxidant electrode (hereinafter referred to as the cathode electrode) 1b which is the other porous electrode, By utilizing the electrochemical reaction occurring at this time, electric energy is taken out from between the electrodes 1a and 1b.

【０００５】この場合、一対のアノード電極１ａとカソ
ード電極１ｂからなる電池（以下、単位セルと称する）
１の出力電圧は、通常の運転条件で０．６〜０．８Ｖと
非常に低いため、実用機では図４に示すように、数百枚
の単位セル１を、電気伝導性かつガス不透過性のセパレ
ータ２、または冷却板３を介して積層して、燃料電池本
体（通常、セルスタックと称される）を形成し、所定の
出力電圧を得るようにしている。In this case, a battery composed of a pair of anode electrode 1a and cathode electrode 1b (hereinafter referred to as a unit cell)
The output voltage of 1 is very low at 0.6 to 0.8 V under normal operating conditions, so in a practical machine, hundreds of unit cells 1 are electrically conductive and gas impermeable as shown in FIG. Are stacked with the separator 2 or the cooling plate 3 interposed therebetween to form a fuel cell main body (usually referred to as a cell stack) to obtain a predetermined output voltage.

【０００６】ところで、この種のリン酸型燃料電池にお
いて、各単位セル１で起こる電気化学反応は発熱反応で
あるため、燃料電池を継続して運転するには、セルの温
度上昇を防止する必要がある。そのため、上述のような
燃料電池本体においては、数枚の単位セル１毎に冷却板
３を挿入し、その内部に冷却媒体を循環させることによ
り、セルから発生する熱を外部に取り出すようにしてい
る。By the way, in this type of phosphoric acid fuel cell, since the electrochemical reaction occurring in each unit cell 1 is an exothermic reaction, in order to continuously operate the fuel cell, it is necessary to prevent the temperature rise of the cell. There is. Therefore, in the fuel cell main body as described above, a cooling plate 3 is inserted for every several unit cells 1 and a cooling medium is circulated inside the cooling plate 3 so that heat generated from the cells is taken out. There is.

【０００７】また、この冷却板３は、高い熱伝導性、電
気伝導性、耐電解質性、耐熱性が要求されることから、
一般的には、図５に部分拡大図を示すように、電気伝導
性混合物で製作され、その内部には冷却管３ａが埋設さ
れている。さらに、冷却管３ａとしては、一般的に、熱
伝導性、耐電解質性に比較的優れたステンレス管等が使
用され、さらに他の冷却板３間との絶縁を保つために、
絶縁部３ｂを介して冷却一次管と接続されている。Further, since the cooling plate 3 is required to have high thermal conductivity, electrical conductivity, electrolyte resistance and heat resistance,
Generally, as shown in a partially enlarged view in FIG. 5, it is made of an electrically conductive mixture, and a cooling pipe 3a is embedded in the inside thereof. Further, as the cooling pipe 3a, generally, a stainless pipe or the like having relatively excellent thermal conductivity and electrolyte resistance is used, and in order to maintain insulation between other cooling plates 3,
It is connected to the cooling primary pipe via the insulating portion 3b.

【０００８】次に、図６は、従来のリン酸型燃料電池発
電プラントの概略構成例を示すブロック図である。図６
において、改質装置６では、天然ガス４と水蒸気５との
混合ガスが、水蒸気改反応により水素リッチガスとされ
て、この水素リッチガスがアノード電極１ａに供給さ
れ、カソード電極１ｂには圧縮空気７が供給される。そ
して、アノード電極１ａに供給された水素リッチガス
は、カソード電極１ｂに供給された圧縮空気７と電気化
学的に反応して、電気、水、および熱となる。Next, FIG. 6 is a block diagram showing a schematic configuration example of a conventional phosphoric acid fuel cell power plant. Figure 6
In the reformer 6, the mixed gas of the natural gas 4 and the steam 5 is converted into a hydrogen-rich gas by the steam reforming reaction, the hydrogen-rich gas is supplied to the anode electrode 1a, and the compressed air 7 is supplied to the cathode electrode 1b. Supplied. Then, the hydrogen-rich gas supplied to the anode electrode 1a electrochemically reacts with the compressed air 7 supplied to the cathode electrode 1b to become electricity, water, and heat.

【０００９】アノード電極１ａを出たガスは、アノード
出口リン酸吸着器８、アノード出口凝縮器９、および改
質装置バーナー１０を介して、大気１１中に放出され
る。また、カソード電極３を出たガスは、カソード出口
リン酸吸着器１２、カソード出口凝縮器１３、および改
質装置バーナー１０を介して、大気１１中に放出され
る。The gas discharged from the anode electrode 1a is discharged into the atmosphere 11 via the anode outlet phosphoric acid adsorber 8, the anode outlet condenser 9, and the reformer burner 10. Further, the gas discharged from the cathode electrode 3 is discharged into the atmosphere 11 via the cathode outlet phosphoric acid adsorber 12, the cathode outlet condenser 13, and the reformer burner 10.

【００１０】ところで、リン酸型燃料電池は、高温状態
で電池電圧が、単位セル１個当たり０．８Ｖ以上に維持
されると、電池触媒のシンタリングが増長して、電池特
性の低下につながる。一方、電池電圧が単位セル１個当
たり０Ｖ以下、すなわち転極現象が生じた場合には、電
解質電気分解が発生して、電池に大きな損傷を与えるこ
とも知られている。このため、リン酸型燃料電池の運転
中はもちろんのこと、起動・停止操作中にも、電圧の管
理が必要となってくる。By the way, in the phosphoric acid fuel cell, when the cell voltage is maintained at 0.8 V or more per unit cell in a high temperature state, sintering of the cell catalyst is increased and the cell characteristics are deteriorated. . On the other hand, it is also known that when the battery voltage is 0 V or less per unit cell, that is, when the reversal phenomenon occurs, electrolyte electrolysis occurs and the battery is greatly damaged. Therefore, it is necessary to manage the voltage not only during the operation of the phosphoric acid fuel cell but also during the start / stop operation.

【００１１】そこで、リン酸型燃料電池の運転中におい
ては、インバーターの電圧保護制御により、許容値内
（通常は０．７〜０．８Ｖ／セル）に電圧が保持され、
もし電池電圧が許容値を超える場合には、緊急運転停止
等の電池の保護対策が施されている。Therefore, during the operation of the phosphoric acid fuel cell, the voltage is maintained within the allowable value (usually 0.7 to 0.8 V / cell) by the voltage protection control of the inverter.
If the battery voltage exceeds the allowable value, battery protection measures such as emergency operation stop are taken.

【００１２】一方、リン酸型燃料電池の起動・停止操作
中、特に停止操作においては、カソード電極１ｂ内に運
転中供給された空気が残留するため、次のような電圧抑
制手段が施されている。On the other hand, during the start / stop operation of the phosphoric acid fuel cell, particularly during the stop operation, the air supplied during operation remains in the cathode electrode 1b, and therefore the following voltage suppressing means is provided. There is.

【００１３】すなわち、運転停止指令に従って、電池温
度降温操作が実施されると共に、カソード供給空気およ
びアノード供給燃料が遮断され、これと同時にカソード
窒素ガス供給ライン２０およびアノード窒素ガス供給ラ
イン２１に設けられた供給弁２２，２３を解放し、不活
性ガス、例えば窒素がアノード電極１ａおよびカソード
電極１ｂに供給され、残留空気および燃料ガスのガスパ
ージが実施される。That is, according to the operation stop command, the battery temperature lowering operation is performed, the cathode supply air and the anode supply fuel are shut off, and at the same time, the cathode nitrogen gas supply line 20 and the anode nitrogen gas supply line 21 are provided. The supply valves 22 and 23 are opened, an inert gas such as nitrogen is supplied to the anode electrode 1a and the cathode electrode 1b, and residual air and fuel gas are purged.

【００１４】また、インバーターは、運転停止指令によ
り、交流出力を低減させてインバーター運転が不可能に
なる微少出力のところで、ダミー抵抗２５と切替える。
ダミー抵抗２５は、任意電圧、例えば０．５Ｖ／セル以
上で投入するように制御されている。そして、このダミ
ー抵抗２５とカソード電極１ｂの窒素ガスパージによっ
て電池電圧が抑制され、運転停止操作中の電池電圧の管
理は完了する。その後、燃料電池本体の温度は、保管温
度（例えば摂氏５０度）まで降温されて、その保管温度
で保管される。Further, the inverter switches to the dummy resistor 25 at the minute output where the AC output is reduced and the inverter cannot be operated by the operation stop command.
The dummy resistor 25 is controlled to be turned on at an arbitrary voltage, for example, 0.5 V / cell or more. Then, the battery voltage is suppressed by the nitrogen gas purging of the dummy resistor 25 and the cathode electrode 1b, and the management of the battery voltage during the operation for stopping the operation is completed. Then, the temperature of the fuel cell main body is lowered to a storage temperature (for example, 50 degrees Celsius) and stored at the storage temperature.

【００１５】ところで、このようなリン酸型燃料電池に
おいて、アノード電極１ａおよびカソード電極１ｂ、さ
らには両者に挟まれたマトリックス層１ｃは多孔質体で
あり、この中に多量のリン酸が蓄えられ、電解質として
の機能や、燃料ガスと酸化剤との直接接触、混合するこ
とを防止するためのシール機能に当てられている。そし
て、このリン酸は、温度およびその雰囲気の湿度によっ
て、体積が変化する性質を有する。By the way, in such a phosphoric acid fuel cell, the anode electrode 1a and the cathode electrode 1b, and the matrix layer 1c sandwiched therebetween are porous bodies, and a large amount of phosphoric acid is stored therein. , And has a function as an electrolyte and a sealing function for preventing direct contact and mixing of the fuel gas and the oxidant. The phosphoric acid has a property that its volume changes depending on the temperature and the humidity of the atmosphere.

【００１６】従って、リン酸型燃料電池の保管中に、湿
分を有する空気がプラントライン内に混入したような場
合には、燃料電池本体中のリン酸が、プラントライン内
に混入してきた空気中の湿分を吸収して、その体積が増
大する。Therefore, when air having moisture is mixed in the plant line during storage of the phosphoric acid fuel cell, the phosphoric acid in the fuel cell body is mixed in the plant line. It absorbs moisture in it and increases its volume.

【００１７】この場合、多孔質体であるアノード電極１
ａ、カソード電極１ｂ、およびマトリックス層１ｃに充
填してあるリン酸が、電極周囲に溢流し、その結果、上
記シール機能の不良、および電解質減少に伴うイオン伝
導性の低下によって、電池寿命の短命化に至る。In this case, the anode electrode 1 which is a porous body
a, the cathode electrode 1b, and the phosphoric acid filling the matrix layer 1c overflow around the electrodes, and as a result, the battery life is shortened due to the poor sealing function and a decrease in ionic conductivity due to a decrease in electrolyte. Leading to

【００１８】また、単位セル１外へリン酸が漏洩したよ
うな場合には、燃料電池本体の積層面に垂れ落ち、燃料
電池本体とアノード電極１ａおよびカソード電極１ｂの
ガス供給排出配管ライン間で液絡状態が生じ、その結
果、絶縁不良に至ることで大きなトラブルを起こす危険
性がある。When phosphoric acid leaks to the outside of the unit cell 1, the phosphoric acid drips down on the laminated surface of the fuel cell main body, and between the fuel cell main body and the gas supply / discharge piping lines of the anode electrode 1a and the cathode electrode 1b. There is a risk of causing a serious trouble due to the occurrence of a liquid junction state, resulting in poor insulation.

【００１９】さらに、アノード電極１ａおよびカソード
電極１ｂは、多孔質体からなるガス拡散電極であり、マ
トリックス層１ｃと接する面には触媒層が形成してあ
る。そして、燃料ガスおよび酸化剤は、上記多孔質体の
細孔部を拡散して触媒層まで移動するので、アノード電
極１ａおよびカソード電極１ｂの多孔質部に、ガス拡散
を妨げない程度にリン酸が充填されるように設計してあ
るが、上述のプラントライン内に混入してきた空気中の
湿分を吸収して、その体積増大に起因したリン酸移動が
生じ、上述の触媒層を含めた多孔質体の細孔部に、所定
以上のリン酸が滞留してしまう現象（以下、フラッディ
ング現象と称する）が発生する。Further, the anode electrode 1a and the cathode electrode 1b are gas diffusion electrodes made of a porous material, and a catalyst layer is formed on the surface in contact with the matrix layer 1c. Since the fuel gas and the oxidant diffuse in the pores of the porous body and move to the catalyst layer, phosphoric acid is introduced into the porous portions of the anode electrode 1a and the cathode electrode 1b to the extent that gas diffusion is not hindered. Is designed to be filled, but absorbs moisture in the air mixed in the plant line described above, causing phosphoric acid transfer due to the increase in volume, and including the catalyst layer described above. A phenomenon (hereinafter referred to as flooding phenomenon) in which phosphoric acid of a predetermined amount or more stays in the pores of the porous body occurs.

【００２０】この結果、燃料ガスおよび酸化剤のガス拡
散不良に伴う電池特性の低下が発生し、電池寿命の短命
化の問題が生じる。一方、本発明者等の研究では、リン
酸型燃料電池の保管中に、プラントライン内に空気が混
入して、空気雰囲気に燃料電池本体がさらされたような
場合、フラッディング現象が加速する結果を得ている。As a result, the cell characteristics are deteriorated due to the poor gas diffusion of the fuel gas and the oxidant, which causes a problem of shortening the life of the cell. On the other hand, in the study by the present inventors, during storage of the phosphoric acid fuel cell, when air was mixed in the plant line and the fuel cell body was exposed to the air atmosphere, the flooding phenomenon was accelerated. Is getting

【００２１】図７は、リン酸型燃料電池の保管時の不活
性ガス雰囲気の場合と空気雰囲気の場合における起動停
止特性試験の結果の一例を示す特性図である。図７よ
り、リン酸型燃料電池の保管時、空気雰囲気の場合に
は、起動停止特性の低下が顕著であり、その要因はフラ
ッディング現象が加速していることが明らかになってい
る。これは、アノード電極１ａおよびカソード電極１ｂ
共に、空気中の酸素によって、約１Ｖの高電位状態（Ｏ
₂ 電位）に保持されるため、電気的吸引力によるリン酸
の移動に伴って、前述の触媒層を含めた多孔質体の細孔
部に所定以上のリン酸が侵入してしまい、結果的にフラ
ッディング現象が加速することによるものと考えられ
る。FIG. 7 is a characteristic diagram showing an example of the result of the start / stop characteristic test in the case of the inert gas atmosphere and the air atmosphere during storage of the phosphoric acid fuel cell. From FIG. 7, it has been clarified that the deterioration of the start-stop characteristic is remarkable when the phosphoric acid fuel cell is stored in the air atmosphere, and the cause thereof is the flooding phenomenon is accelerated. This is the anode electrode 1a and the cathode electrode 1b.
In both cases, due to the oxygen in the air, a high potential state (O
₍₂ potential), phosphoric acid more than a predetermined amount penetrates into the pores of the porous body including the catalyst layer as the phosphoric acid moves due to the electric attraction force. It is considered that the flooding phenomenon is accelerated.

【００２２】その結果、前述のリン酸体積変化に伴うリ
ン酸移動の場合と同様に、燃料ガスおよび酸化剤のガス
拡散不良に伴う電池特性の低下が発生して、電池寿命の
短命化につながるという問題点がある。As a result, as in the case of the phosphoric acid transfer due to the change in the phosphoric acid volume, the battery characteristics are deteriorated due to the poor gas diffusion of the fuel gas and the oxidant, which leads to the shortening of the battery life. There is a problem.

【００２３】[0023]

【発明が解決しようとする課題】以上のように、従来の
リン酸型燃料電池発電プラントにおいては、長期間の保
管に際して電池特性の低下が発生するという問題があっ
た。本発明の目的は、リン酸型燃料電池発電プラントの
運転停止中の電池保管状態における燃料電池本体内のリ
ン酸移動を最小限に抑えて、リン酸を所定の位置に保持
管理することができ、もって長期間の保管においても電
池特性を低下させることなく安定に維持することが可能
なリン酸型燃料電池発電プラントおよびその保管方法を
提供することにある。As described above, in the conventional phosphoric acid fuel cell power generation plant, there is a problem that the cell characteristics are deteriorated during long-term storage. The object of the present invention is to minimize the movement of phosphoric acid in the fuel cell main body in the cell storage state during operation stoppage of the phosphoric acid fuel cell power plant, and to maintain and manage phosphoric acid at a predetermined position. Accordingly, it is an object of the present invention to provide a phosphoric acid fuel cell power generation plant and a storage method thereof, which can stably maintain the cell characteristics without deterioration even during long-term storage.

【００２４】[0024]

【課題を解決するための手段】上記の目的を達成するた
めに、電解質を含浸した電解質層を挟んで燃料極および
酸化剤極を配置して単位セルを構成し、かつこの単位セ
ルを、セパレーター、または内部に冷媒を循環させる冷
却管が埋設された冷却板を介して複数個積層して燃料電
池本体を形成し、燃料極および酸化剤極に燃料ガスおよ
び酸化剤をそれぞれ供給することにより、この時に起こ
る電気化学反応によって電気出力を得るようにしたリン
酸型燃料電池発電プラントを保管する方法において、ま
ず、請求項１に係る発明では、リン酸型燃料電池発電プ
ラントの運転停止中の電池保管時に、燃料極および酸化
剤極の少なくともいずれか一方に、連続的または間欠的
に乾燥不活性ガスを供給するようにしている。In order to achieve the above object, a fuel cell and an oxidant electrode are arranged with an electrolyte layer impregnated with an electrolyte interposed therebetween to form a unit cell, and the unit cell is formed into a separator. , Or a plurality of cooling tubes that circulate a cooling medium inside are stacked to form a fuel cell main body through a cooling plate, and by supplying a fuel gas and an oxidant to a fuel electrode and an oxidizer electrode, respectively, In a method of storing a phosphoric acid fuel cell power plant in which an electric output is obtained by an electrochemical reaction that occurs at this time, first, in the invention according to claim 1, the battery in operation of the phosphoric acid fuel cell power plant is stopped. At the time of storage, the dry inert gas is continuously or intermittently supplied to at least one of the fuel electrode and the oxidizer electrode.

【００２５】また、請求項２に係る発明では、リン酸型
燃料電池発電プラントの運転停止中の電池保管時に、燃
料電池本体の交流抵抗を測定してその経時変化を監視
し、当該交流抵抗の値があらかじめ定められた管理値以
下になった時に、燃料極に水素を含む乾燥ガスを供給し
て燃料電池本体の発生電圧を測定し、かつ当該測定され
た電池電圧が所定値以上になった時に、燃料電池本体の
燃料極と酸化剤極との間を電圧抑制抵抗を介して電気的
に短絡するようにしている。Further, in the invention according to claim 2, during storage of the battery while the phosphoric acid fuel cell power plant is stopped, the AC resistance of the fuel cell main body is measured to monitor its change over time, and the AC resistance When the value falls below a predetermined control value, dry gas containing hydrogen is supplied to the fuel electrode to measure the generated voltage of the fuel cell body, and the measured cell voltage exceeds a predetermined value. At times, the fuel electrode and the oxidant electrode of the fuel cell body are electrically short-circuited via a voltage suppressing resistor.

【００２６】さらに、請求項３に係る発明では、リン酸
型燃料電池発電プラントの運転停止中の電池保管時に、
燃料極および酸化剤極の少なくともいずれか一方に、連
続的または間欠的に乾燥不活性ガスを供給するように
し、また燃料電池本体の交流抵抗を測定してその経時変
化を監視し、当該交流抵抗の値があらかじめ定められた
管理値以下になった時に、燃料極に水素を含む乾燥ガス
を供給して燃料電池本体の発生電圧を測定し、かつ当該
測定された電池電圧が所定値以上になった時に、燃料電
池本体の燃料極と酸化剤極との間を電圧抑制抵抗を介し
て電気的に短絡するようにしている。Further, in the invention according to claim 3, during storage of the battery while the phosphoric acid fuel cell power plant is stopped,
A dry inert gas is continuously or intermittently supplied to at least one of the fuel electrode and the oxidizer electrode, and the AC resistance of the fuel cell body is measured to monitor its change over time, and the AC resistance When the value of is below a predetermined control value, dry gas containing hydrogen is supplied to the fuel electrode to measure the generated voltage of the fuel cell body, and the measured cell voltage is above a predetermined value. At this time, the fuel electrode and the oxidant electrode of the fuel cell body are electrically short-circuited via the voltage suppressing resistance.

【００２７】ここで、特に上記燃料電池本体の電池電圧
が所定値以上になった時に、当該燃料電池本体中の過大
電圧発生部分に電圧抑制抵抗を投入するようにしてい
る。また、上記燃料電池本体の各冷却板間の電圧をそれ
ぞれ測定し、当該電圧が所定値以上になった任意の冷却
板間を電圧抑制抵抗を介して電気的に短絡するようにし
ている。Here, in particular, when the cell voltage of the fuel cell main body becomes a predetermined value or more, a voltage suppressing resistor is inserted into the excessive voltage generating portion in the fuel cell main body. Further, the voltage between the respective cooling plates of the fuel cell main body is measured, and any cooling plate whose voltage becomes a predetermined value or more is electrically short-circuited via a voltage suppressing resistor.

【００２８】一方、電解質を含浸した電解質層を挟んで
燃料極および酸化剤極を配置して単位セルを構成し、か
つこの単位セルを、セパレーター、または内部に冷媒を
循環させる冷却管が埋設された冷却板を介して複数個積
層して燃料電池本体を形成し、燃料極および酸化剤極に
燃料ガスおよび酸化剤をそれぞれ供給することにより、
この時に起こる電気化学反応によって電気出力を得るよ
うにしたリン酸型燃料電池発電プラントにおいて、ま
ず、請求項６に係る発明では、燃料極および酸化剤極の
入口側ラインにそれぞれ配置され、燃料電池発電プラン
ト本体の運転停止中の電池保管時に全閉される遮断弁
と、燃料極側の遮断弁と燃料極との間、および酸化剤極
側の遮断弁と酸化剤極との間にそれぞれ接続され、燃料
極および酸化剤極に乾燥不活性ガスをそれぞれ供給する
乾燥不活性ガス供給ラインと、各乾燥不活性ガス供給ラ
インにそれぞれ配置され、リン酸型燃料電池発電プラン
ト本体の運転停止中の電池保管時に開制御される供給制
御弁とを備えて成る。On the other hand, a fuel cell and an oxidizer electrode are arranged with an electrolyte layer impregnated with an electrolyte interposed therebetween to form a unit cell, and this unit cell is embedded with a separator or a cooling pipe for circulating a refrigerant therein. By forming a plurality of fuel cell bodies by stacking them through the cooling plate, and supplying the fuel gas and the oxidant to the fuel electrode and the oxidant electrode, respectively,
In a phosphoric acid fuel cell power generation plant configured to obtain an electric output by an electrochemical reaction that occurs at this time, first, in the invention according to claim 6, in the fuel cell and the oxidant electrode, the fuel cell is arranged at the inlet side lines, respectively. Connected between the shutoff valve that is fully closed when the battery is stored while the power plant is out of operation, the shutoff valve on the fuel electrode side and the fuel electrode, and the shutoff valve on the oxidizer electrode side and the oxidant electrode The dry inert gas supply line for supplying dry inert gas to the fuel electrode and the oxidizer electrode, and the dry inert gas supply line for supplying dry inert gas, respectively. And a supply control valve whose opening is controlled when the battery is stored.

【００２９】また、請求項７に係る発明では、燃料極側
の遮断弁と燃料極との間に接続され、燃料極に水素を含
む乾燥ガスを供給する乾燥ガス供給ラインと、乾燥ガス
供給ラインに配置された供給制御弁と、リン酸型燃料電
池発電プラント本体の運転停止中の電池保管時における
燃料電池本体の交流抵抗を測定する交流抵抗検出手段
と、燃料電池本体の発生電圧を測定する電圧検出手段
と、交流抵抗検出手段により測定された交流抵抗の値が
あらかじめ定められた管理値以下になった場合に、供給
制御弁を開制御すると共に、当該第２の供給制御弁の開
制御時に電圧検出手段により測定された電池電圧が所定
値以上になった場合に、燃料電池本体の燃料極と酸化剤
極との間を電圧抑制抵抗を介して電気的に短絡するよう
に制御する電圧抑制制御手段とを備えて成る。Further, in the invention according to claim 7, a dry gas supply line connected between the shutoff valve on the fuel electrode side and the fuel electrode, for supplying a dry gas containing hydrogen to the fuel electrode, and a dry gas supply line. , A supply control valve arranged in the, a resistance control means for measuring the AC resistance of the fuel cell main body when the phosphoric acid fuel cell power plant main body is stored while the operation is stopped, and the generated voltage of the fuel cell main body When the value of the AC resistance measured by the voltage detecting means and the AC resistance detecting means becomes less than or equal to a predetermined control value, the supply control valve is opened and the second supply control valve is opened. At the time, when the cell voltage measured by the voltage detection means exceeds a predetermined value, the voltage that controls to electrically short-circuit between the fuel electrode and the oxidant electrode of the fuel cell body via the voltage suppression resistor. Suppression system Made and means.

【００３０】さらに、請求項８に係る発明では、燃料極
および酸化剤極の入口側ラインにそれぞれ配置され、リ
ン酸型燃料電池発電プラント本体の運転停止中の電池保
管時に全閉される遮断弁と、燃料極側の遮断弁と燃料極
との間、および酸化剤極側の遮断弁と酸化剤極との間に
それぞれ接続され、燃料極および酸化剤極に乾燥不活性
ガスをそれぞれ供給する乾燥不活性ガス供給ラインと、
各乾燥不活性ガス供給ラインにそれぞれ配置され、燃料
電池発電プラント本体の運転停止中の電池保管時に開制
御される第１の供給制御弁と、燃料極側の遮断弁と燃料
極との間に接続され、燃料極に水素を含む乾燥ガスを供
給する乾燥ガス供給ラインと、乾燥ガス供給ラインに配
置された第２の供給制御弁と、燃料電池発電プラント本
体の運転停止中の電池保管時における燃料電池本体の交
流抵抗を測定する交流抵抗検出手段と、燃料電池本体の
発生電圧を測定する電圧検出手段と、交流抵抗検出手段
により測定された交流抵抗の値があらかじめ定められた
管理値以下になった場合に、第２の供給制御弁を開制御
すると共に、当該第２の供給制御弁の開制御時に電圧検
出手段により測定された電池電圧が所定値以上になった
場合に、燃料電池本体の燃料極と酸化剤極との間を電圧
抑制抵抗を介して電気的に短絡するように制御する電圧
抑制制御手段とを備えて成る。Further, in the invention according to claim 8, a shut-off valve which is arranged in each of the inlet side lines of the fuel electrode and the oxidizer electrode and which is fully closed when the battery is stored while the operation of the phosphoric acid fuel cell power plant main body is stopped. And a shutoff valve on the fuel electrode side and the fuel electrode, and a shutoff valve on the oxidant electrode side and the oxidant electrode, respectively, to supply a dry inert gas to the fuel electrode and the oxidant electrode, respectively. A dry inert gas supply line,
Between the first supply control valve, which is arranged in each dry inert gas supply line and is opened and controlled when the fuel cell power plant main body is in operation while the battery is stored, and the shutoff valve on the fuel electrode side and the fuel electrode A dry gas supply line that is connected and supplies a dry gas containing hydrogen to the fuel electrode, a second supply control valve that is arranged in the dry gas supply line, and a battery storage when the fuel cell power plant main unit is out of operation AC resistance detection means for measuring the AC resistance of the fuel cell body, voltage detection means for measuring the generated voltage of the fuel cell body, and the value of the AC resistance measured by the AC resistance detection means is below a predetermined control value. In this case, the second supply control valve is controlled to be opened, and when the battery voltage measured by the voltage detecting means during the opening control of the second supply control valve becomes equal to or higher than a predetermined value, the fuel cell Comprising a voltage suppression control means for controlling to electrically short-circuit via the voltage suppression resistance between the body of the fuel electrode and the oxidizer electrode.

【００３１】ここで、特に上記電圧抑制制御手段として
は、燃料電池本体の電池電圧が所定値以上になった場合
に、当該燃料電池本体中の過大電圧発生部分に電圧抑制
抵抗を投入するように制御する。Here, in particular, as the voltage suppression control means, when the cell voltage of the fuel cell main body becomes a predetermined value or more, a voltage suppression resistor is applied to the excessive voltage generating portion in the fuel cell main body. Control.

【００３２】また、上記電圧抑制制御手段としては、燃
料電池本体の各冷却板間の電圧をそれぞれ測定し、当該
電圧が所定値以上になった任意の冷却板間を電圧抑制抵
抗を介して電気的に短絡するように制御する。As the voltage suppression control means, the voltage between the respective cooling plates of the fuel cell body is measured, and the voltage between the arbitrary cooling plates whose voltage exceeds a predetermined value is electrically connected via the voltage suppression resistor. Control so that it is short-circuited.

【００３３】さらに、上記各冷却板に埋設されている冷
却管に電圧測定信号線および電気的導線を接続し、各冷
却板間の電圧をそれぞれ測定する電圧測定回路と、任意
の冷却板間を電圧抑制抵抗を介して電気的に短絡する電
気回路を備えて成る。Further, a voltage measuring signal line and an electric conductor are connected to the cooling pipes embedded in the respective cooling plates, and a voltage measuring circuit for measuring the voltage between the respective cooling plates and an arbitrary cooling plate are connected. It is provided with an electric circuit that is electrically short-circuited via a voltage suppressing resistor.

【００３４】[0034]

【作用】従って、本発明のリン酸型燃料電池発電プラン
トおよびその保管方法においては、リン酸型燃料電池発
電プラント本体の運転停止中の電池保管状態時に、燃料
極および酸化剤極の直前の入口側に配置した遮断弁を全
閉し、かつ遮断弁の下流で燃料極および酸化剤極の入口
側に配置した乾燥不活性ガス供給制御弁を開制御するこ
とにより、燃料極および酸化剤極に乾燥不活性ガスが連
続的または間欠的に供給されるため、燃料極および酸化
剤極を乾燥不活性ガス雰囲気に維持して、外部の空気が
燃料電池本体内へ混入することを防止することができ
る。Therefore, in the phosphoric acid fuel cell power plant and the method for storing the same according to the present invention, the inlets just before the fuel electrode and the oxidizer electrode are in the battery storage state while the phosphoric acid fuel cell power plant main body is not operating. The shutoff valve placed on the side of the fuel cell is closed completely, and the dry inert gas supply control valve placed downstream of the shutoff valve on the inlet side of the fuel electrode and the oxidizer electrode is controlled to be opened, so that Since the dry inert gas is continuously or intermittently supplied, it is possible to maintain the fuel electrode and the oxidizer electrode in a dry inert gas atmosphere and prevent external air from mixing into the fuel cell body. it can.

【００３５】また、リン酸型燃料電池発電プラント本体
の運転停止中の電池保管状態時に、燃料電池本体の交流
抵抗を測定して、その交流抵抗の値が所定値を逸脱した
場合には、燃料極の入口側の乾燥ガス供給ラインに設け
られた供給制御弁を開制御して、燃料極に水素を含む乾
燥ガスを供給し、さらにこの乾燥ガスが供給された時の
燃料電池本体の発生電圧を測定して、その電池電圧が所
定値以上である場合には、燃料電池本体の燃料極と酸化
剤極との間を電圧抑制抵抗を介して電気的に短絡する、
すなわち燃料電池本体中の過大電圧発生部分（任意の冷
却板間で局部的に電池電圧が所定値以上発生している部
分）に電圧抑制抵抗を投入することにより、燃料電池本
体の燃料極と酸化剤極との間の電圧を抑制することがで
きる。Further, when the phosphoric acid fuel cell power plant main body is in a storage state while the main body is in operation, the AC resistance of the fuel cell main body is measured, and if the AC resistance value deviates from a predetermined value, the fuel is The supply control valve provided on the dry gas supply line on the inlet side of the electrode is controlled to open to supply the dry gas containing hydrogen to the fuel electrode, and the voltage generated by the fuel cell main body when this dry gas is supplied. If the cell voltage is higher than or equal to a predetermined value, the fuel cell and the oxidant electrode of the fuel cell body are electrically short-circuited via a voltage suppression resistor.
That is, by inserting a voltage suppression resistor in the portion where the excessive voltage is generated in the fuel cell main body (the portion where the cell voltage locally exceeds the predetermined value between arbitrary cooling plates), the fuel electrode of the fuel cell main body and the oxidation The voltage between the agent electrode can be suppressed.

【００３６】以上により、リン酸型燃料電池発電プラン
トの運転停止中の燃料電池本体の電極電位とリン酸体積
を所定の値に管理することができ、もって長期間の保管
においても電池特性を低下させることなく安定に維持す
ることが可能となる。As described above, the electrode potential and the phosphoric acid volume of the fuel cell main body during the operation stop of the phosphoric acid fuel cell power plant can be controlled to a predetermined value, so that the cell characteristics are deteriorated even during long-term storage. It is possible to maintain the stability without causing it.

【００３７】[0037]

【実施例】以下、本発明の一実施例について図面を参照
して詳細に説明する。図１は本発明によるリン酸型燃料
電池発電プラントの全体構成例を示すブロック図、図２
は図１における燃料電池本体冷却板の電気回路の一例を
示す拡大図であり、図４ないし図６と同一部分には同一
符号を付してその説明を省略し、ここでは異なる部分に
ついてのみ述べる。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. 1 is a block diagram showing an example of the overall configuration of a phosphoric acid fuel cell power plant according to the present invention, FIG.
FIG. 4 is an enlarged view showing an example of an electric circuit of the cooling plate for the fuel cell main body in FIG. 1, the same parts as those in FIGS. 4 to 6 are designated by the same reference numerals, and the description thereof will be omitted. .

【００３８】図１において、アノード電極１ａおよびカ
ソード電極１ｂの入口ラインには、アノード入口遮断弁
２８およびカソード入口遮断弁２９をそれぞれ設けてい
る。このアノード入口遮断弁２８，カソード入口遮断弁
２９は、本リン酸型燃料電池発電プラントの運転停止中
の電池保管時に、手動により、または自動的に全閉され
るものである。In FIG. 1, an anode inlet cutoff valve 28 and a cathode inlet cutoff valve 29 are provided in the inlet lines of the anode electrode 1a and the cathode electrode 1b, respectively. The anode inlet cutoff valve 28 and the cathode inlet cutoff valve 29 are fully closed manually or automatically when the batteries are stored while the operation of the present phosphoric acid fuel cell power plant is stopped.

【００３９】また、アノード入口遮断弁２８とアノード
電極１ａとの間のラインには、乾燥不活性ガス（本例で
は乾燥Ｎ₂ ガス）を供給する乾燥Ｎ₂ ガス供給ライン２
１、および水素を含む乾燥ガスを供給する乾燥水素供給
ライン２６をそれぞれ接続している。A dry N ₂ gas supply line 2 for supplying a dry inert gas (dry N ₂ gas in this example) is provided in a line between the anode inlet cutoff valve 28 and the anode electrode 1a.
1 and a dry hydrogen supply line 26 for supplying a dry gas containing hydrogen are connected to each other.

【００４０】さらに、この乾燥Ｎ₂ ガス供給ライン２１
および乾燥水素供給ライン２６には、供給制御弁２３お
よび２７をそれぞれ配置している。この供給制御弁２３
は、本燃料電池発電プラントの運転停止中の電池保管時
に、手動により、または自動的に開制御されるものであ
る。Further, this dry N ₂ gas supply line 21
In the dry hydrogen supply line 26, supply control valves 23 and 27 are arranged, respectively. This supply control valve 23
Is to be controlled manually or automatically when the battery is stored while the fuel cell power plant is not operating.

【００４１】なお、上記乾燥水素供給ライン２６には、
運用面の安全を考慮して、微小濃度水素と不活性ガス
（例えば、１％Ｈ₂ 、９９％Ｎ₂ 組成）とから成る水素
混合ガスを使用する。In the dry hydrogen supply line 26,
In consideration of operational safety, a hydrogen mixed gas consisting of a minute concentration of hydrogen and an inert gas (for example, 1% H ₂ and 99% N ₂ composition) is used.

【００４２】一方、カソード入口遮断弁２９とカソード
電極１ｂとの間のラインには、乾燥不活性ガス（本例で
は乾燥Ｎ₂ ガス）を供給する乾燥Ｎ₂ ガス供給ライン２
０を接続している。On the other hand, a dry N ₂ gas supply line 2 for supplying a dry inert gas (dry N ₂ gas in this example) to the line between the cathode inlet cutoff valve 29 and the cathode electrode 1b.
0 is connected.

【００４３】また、この乾燥Ｎ₂ ガス供給ライン２０に
は、供給制御弁２２を配置している。この供給制御弁２
２は、本燃料電池発電プラントの運転停止中の電池保管
時に、手動により、または自動的に開制御されるもので
ある。A supply control valve 22 is arranged in the dry N ₂ gas supply line 20. This supply control valve 2
The number 2 is controlled to be opened manually or automatically when the battery is stored while the fuel cell power plant is stopped.

【００４４】一方、燃料電池本体には、その交流抵抗を
測定する交流抵抗検出器３０を設けており、この交流抵
抗検出器３０の出力信号を、交流抵抗実測値に応じてア
ノード電極入口側の乾燥水素供給ライン２６に配置され
た供給制御弁２７の弁開度を制御する電圧抑制制御装置
３１に入力するようにしている。On the other hand, the fuel cell main body is provided with an AC resistance detector 30 for measuring its AC resistance. The output signal of this AC resistance detector 30 is supplied to the anode electrode inlet side according to the AC resistance actual measurement value. The voltage is supplied to the voltage suppression control device 31 which controls the valve opening degree of the supply control valve 27 arranged in the dry hydrogen supply line 26.

【００４５】また、図２に示すように、燃料電池本体の
各冷却板３に埋設された冷却管３ａには、それぞれ電圧
測定線３２を接続し、電圧検出器３３に配線するように
している。Further, as shown in FIG. 2, a voltage measuring line 32 is connected to each cooling pipe 3a embedded in each cooling plate 3 of the fuel cell main body, and is connected to a voltage detector 33. .

【００４６】さらに、各冷却管３ａには、それぞれ電気
的導線３４を接続し、電圧抑制抵抗３５を介して電気的
短絡回路３６を配置している。さらにまた、電圧検出器
３３の出力信号を、電圧抑制制御装置３１に入力し、そ
の電圧測定値に応じて電気的短絡回路３６を制御するよ
うにしている。Further, an electric conductor 34 is connected to each cooling pipe 3a, and an electric short circuit 36 is arranged via a voltage suppressing resistor 35. Furthermore, the output signal of the voltage detector 33 is input to the voltage suppression control device 31, and the electrical short circuit 36 is controlled according to the voltage measurement value.

【００４７】次に、以上のように構成した本実施例のリ
ン酸型燃料電池発電プラントの保管方法について説明す
る。いま、リン酸型燃料電池発電プラントの運転停止中
の電池保管状態においては、アノード電極１ａおよびカ
ソード電極１ｂの入口側にそれぞれ配置したアノード入
口遮断弁２８，カソード入口遮断弁２９を全閉し、かつ
このアノード入口遮断弁２８，カソード入口遮断弁２９
の下流側で、アノード電極１ａおよびカソード電極１ｂ
の入口側にそれぞれ配置した乾燥Ｎ₂ ガス供給制御弁２
２および２３に開信号を与えることにより、アノード電
極１ａおよびカソード電極１ｂに、乾燥Ｎ₂ ガスが供給
される。Next, a method of storing the phosphoric acid fuel cell power plant of the present embodiment having the above-mentioned structure will be described. Now, in the battery storage state during the operation stop of the phosphoric acid fuel cell power plant, the anode inlet cutoff valve 28 and the cathode inlet cutoff valve 29 respectively arranged on the inlet sides of the anode electrode 1a and the cathode electrode 1b are fully closed, Also, the anode inlet cutoff valve 28 and the cathode inlet cutoff valve 29
On the downstream side of the anode electrode 1a and the cathode electrode 1b
Dry N ₂ gas supply control valves 2 respectively arranged on the inlet side of the
By giving an open signal to 2 and 23, dry N ₂ gas is supplied to the anode electrode 1a and the cathode electrode 1b.

【００４８】これにより、アノード電極１ａおよびカソ
ード電極１ｂを乾燥Ｎ₂ ガス雰囲気に維持して、外部の
空気が燃料電池本体内へ混入することを防止することが
できる。This makes it possible to maintain the anode electrode 1a and the cathode electrode 1b in a dry N ₂ gas atmosphere and prevent external air from entering the fuel cell body.

【００４９】なお、上記において、乾燥Ｎ₂ ガスを連続
的に供給した場合には、コスト面の問題が生じるため、
乾燥Ｎ₂ ガス供給制御弁２２，２３の開閉制御を定期的
に行なうことにより、アノード電極１ａおよびカソード
電極１ｂに乾燥Ｎ₂ ガスを間欠的に供給するようにして
も、同等の効果を得ることができる。In the above, if the dry N ₂ gas is continuously supplied, a cost problem arises.
By opening and closing control of the drying N ₂ gas supply control valve 22 and 23 periodically, even if the dry N ₂ gas to the anode electrode 1a and the cathode electrode 1b so as to intermittently feed, to obtain the same effect You can

【００５０】一方、リン酸型燃料電池発電プラントの運
転停止中の電池保管状態においては、燃料電池本体の交
流抵抗が、交流抵抗検出器３０により検出され、その出
力信号が電圧抑制制御装置３１に与えられる。On the other hand, when the phosphoric acid type fuel cell power plant is in the storage state while the operation is stopped, the AC resistance of the fuel cell body is detected by the AC resistance detector 30, and the output signal thereof is sent to the voltage suppression control device 31. Given.

【００５１】なお、この場合、燃料電池本体の交流抵抗
を測定するのは、直流抵抗測定のために直流電源を用い
ると、燃料電池電極上で電極反応が進行して分極が生じ
るため、正しい抵抗が測定できないからである。しか
し、電源として、１〜１０ｋＨｚの交流抵抗を用いる
と、電流の方向が速く変化するので、このような分極は
取り除かれ、正確な抵抗が測定される。従って、交流抵
抗検出器３０は、１〜１０ｋＨｚの交流電源を有するも
のである。In this case, the AC resistance of the fuel cell main body is measured by using a DC power source for measuring the DC resistance, because the electrode reaction proceeds on the fuel cell electrode to cause polarization, and thus the correct resistance is measured. Is not measurable. However, when an alternating current resistance of 1 to 10 kHz is used as a power source, the direction of the current changes rapidly, so such polarization is removed, and an accurate resistance is measured. Therefore, the AC resistance detector 30 has an AC power supply of 1 to 10 kHz.

【００５２】ところで、燃料電池本体の温度が一定の場
合、燃料電池本体の交流抵抗は、アノード電極１ａおよ
びカソード電極１ｂのリン酸濡れ状態に伴う接触抵抗に
大きく依存するため、燃料電池本体の保管中に外部空気
が混入し、燃料電池本体内のリン酸が吸湿により体積変
化（リン酸濃度変化）が生じたような場合、または空気
中Ｏ₂ の存在に伴う電極高電位発生状態に起因した電気
吸引力によるリン酸移動が生じたような場合には、図３
に示すように交流抵抗に変化（減少）が見られる。By the way, when the temperature of the fuel cell body is constant, the AC resistance of the fuel cell body largely depends on the contact resistance of the anode electrode 1a and the cathode electrode 1b due to the wet state of phosphoric acid. External air was mixed in, and the volume of phosphoric acid in the fuel cell body changed due to moisture absorption (change in phosphoric acid concentration), or the high electrode potential generation state due to the presence of O _{2 in} the air In the case where phosphoric acid transfer due to electric attraction occurs,
As shown in, there is a change (decrease) in AC resistance.

【００５３】通常、リン酸型燃料電池発電プラントの運
転停止中、燃料電池本体は温度が摂氏５０度程度に保持
され、保管当初は、アノード電極１ａおよびカソード電
極１ｂが、乾燥Ｎ₂ ガス雰囲気に保持される。Normally, while the operation of the phosphoric acid fuel cell power plant is stopped, the temperature of the fuel cell body is maintained at about 50 degrees Celsius, and the anode electrode 1a and the cathode electrode 1b are initially stored in a dry N ₂ gas atmosphere. Retained.

【００５４】以上のような点から、電圧抑制制御装置３
１では、燃料電池本体の保管当初の交流抵抗Ｒ_ac（初期
値）と、その後の保管中に検出した交流抵抗Ｒ_ac（検出
値）との比較が実施される。From the above points, the voltage suppression control device 3
In 1, the AC resistance R _ac (initial value) at the beginning of storage of the fuel cell main body is compared with the AC resistance R _ac (detection value) detected during the subsequent storage.

【００５５】この結果、経時的に交流抵抗に減少傾向が
見られた場合、例えば下記のような関係が成立した場合
には、アノード電極１ａまたはカソード電極１ｂに、外
部の空気が混入している状態であると判断し、以下に示
すような電極電圧抑制操作に移行する。As a result, when the AC resistance tends to decrease over time, for example, when the following relationship is established, external air is mixed in the anode electrode 1a or the cathode electrode 1b. It is judged to be in the state, and the electrode voltage suppressing operation as described below is performed.

【００５６】Ｒ_ac（初期値）×０．９＞Ｒ_ac（検出値）
（初期値より１０％が減少した場合）なお、先に述べたように、外部の空気中の湿分を吸収し
て、燃料電池本体の電極内のリン酸体積が変化（増大）
した場合にも、燃料電池本体の交流抵抗の減少が見られ
るが、前述したアノード電極１ａおよびカソード電極１
ｂへの乾燥Ｎ₂ガスの連続的または間欠的な供給によっ
て、電極中水蒸気分圧の上昇が抑制され、燃料電池本体
の電極内リン酸体積変化を抑える操作が実施される。R _ac (initial value) × 0.9> R _ac (detection value)
(In the case of 10% decrease from the initial value) As described above, the volume of phosphoric acid in the electrode of the fuel cell body changes (increases) by absorbing moisture in the outside air.
When the fuel cell body is subjected to a decrease in AC resistance, the above-mentioned anode electrode 1a and cathode electrode 1
By continuously or intermittently supplying the dry N ₂ gas to b, the increase of the partial pressure of water vapor in the electrode is suppressed, and the operation of suppressing the phosphoric acid volume change in the electrode of the fuel cell main body is performed.

【００５７】従って、アノード電極１ａおよびカソード
電極１ｂへの乾燥Ｎ₂ ガスの供給を実施中に、燃料電池
本体の交流抵抗が減少する現象は、外部空気が燃料電池
本体内に混入して、Ｏ₂ が電極触媒に吸着し、電極の高
電位（約１Ｖ）状態が生じているものと判断できる。Therefore, the phenomenon that the AC resistance of the fuel cell main body decreases while the dry N ₂ gas is being supplied to the anode electrode 1a and the cathode electrode 1b is that external air is mixed in the fuel cell main body and _It can be judged that ₂ is adsorbed on the electrode catalyst and a high potential (about 1 V) state of the electrode is generated.

【００５８】一方、電圧抑制操作移行と判断した電圧抑
制制御装置３１は、アノード電極１ａ入口側の乾燥水素
供給ライン２６上の供給制御弁２７に開信号を与えて、
アノード電極１ａに乾燥水素が供給される。そして、ア
ノード電極１ａに供給された乾燥水素は、先にアノード
電極１ａに混入、吸着している酸素（Ｏ₂ ）に置き替わ
り、触媒に吸着して、アノード電極１ａの電位が０Ｖ
（水素電位）に保持される。On the other hand, the voltage suppression control device 31, which judges that the voltage suppression operation has been shifted, gives an open signal to the supply control valve 27 on the dry hydrogen supply line 26 on the inlet side of the anode electrode 1a,
Dry hydrogen is supplied to the anode electrode 1a. Then, the dry hydrogen supplied to the anode electrode 1a is replaced by oxygen (O ₂ ) which is mixed and adsorbed in the anode electrode 1a first and is adsorbed by the catalyst, so that the potential of the anode electrode 1a becomes 0V.
(Hydrogen potential).

【００５９】この時、カソード電極１ｂに混入、吸着し
ている酸素（Ｏ₂ ）によって、燃料電池本体に電圧が発
生する。そして、この発生電圧は、カソード電極１ｂに
混入している酸素（０₂ ）濃度に依存する。At this time, a voltage is generated in the fuel cell main body due to oxygen (O ₂ ) mixed and adsorbed in the cathode electrode 1b. The generated voltage depends on the concentration of oxygen (0 ₂ ) mixed in the cathode electrode 1b.

【００６０】一方、冷却管３ａに配置した電圧測定線３
２を介して、各冷却板３間の電圧が電圧検出器３３によ
り測定され、その測定値は電圧抑制制御装置３１に与え
られる。On the other hand, the voltage measuring line 3 arranged on the cooling pipe 3a
Via 2, the voltage across each cooling plate 3 is measured by the voltage detector 33, and the measured value is given to the voltage suppression control device 31.

【００６１】これにより、電圧抑制制御装置３１では、
各冷却板３間の電圧が所定値を満足しているかの比較が
実施される。すなわち、例えば下記のような関係が成立
するかの検出が実施される。As a result, in the voltage suppression control device 31,
A comparison is made as to whether the voltage between the cooling plates 3 satisfies a predetermined value. That is, for example, it is detected whether the following relationship is established.

【００６２】（各冷却板３間の電圧）／（冷却板３間の
単位セル１数）＜０．８Ｖ（セル管理最大値）以上により、燃料電池本体の全体、または燃料電池本体
内の複数積層した単位セル１の一部に、上記の関係が成
立しない所定値以上の電圧が発生していることが検出さ
れた場合、電圧抑制制御装置３１は、その電圧発生部分
に対応する電気短絡回路３６に制御信号を出力して、電
圧抑制抵抗３５を介した短絡回路が形成される。(Voltage between cooling plates 3) / (number of unit cells 1 between cooling plates 3) <0.8 V (maximum cell management value) As described above, the entire fuel cell main body or a plurality of fuel cell main bodies may be provided. When it is detected that a voltage equal to or higher than a predetermined value that does not satisfy the above relationship is generated in a part of the stacked unit cells 1, the voltage suppression control device 31 determines that the electrical short circuit corresponding to the voltage generation part. A control signal is output to 36 to form a short circuit via the voltage suppression resistor 35.

【００６３】この結果、所定値以上の電圧が発生した部
分の電力は、電圧抑制抵抗３５によって消費され（カソ
ード電極１ｂの酸素（Ｏ₂ ）が電気化学反応で消費さ
れ）、電池電圧を所定値内に抑制管理することができ
る。As a result, the power of the portion where the voltage of the predetermined value or more is generated is consumed by the voltage suppressing resistor 35 (oxygen (O ₂ ) of the cathode electrode 1b is consumed by the electrochemical reaction), and the battery voltage is set to the predetermined value. Can be controlled within.

【００６４】なお、上記において、局部的に所定値以上
の電圧が発生した場合に、燃料電池本体の全体に電圧抑
制抵抗３５を介した短絡回路を形成すると、電圧発生が
生じていない単位セル１において、転極現象が生じる恐
れがある。従って、前述したように、局部的な所定値以
上の電圧が発生した部分だけの電圧を抑制する操作を行
うことが好ましい。In the above, when a voltage of a predetermined value or higher is locally generated, if a short circuit is formed in the entire fuel cell main body through the voltage suppressing resistor 35, the unit cell 1 in which the voltage is not generated is generated. In, there is a possibility that a reversal phenomenon may occur. Therefore, as described above, it is preferable to perform the operation of suppressing the voltage of only the portion where the voltage of the local predetermined value or more is generated.

【００６５】上述したように、本実施例では、リン酸型
燃料電池発電プラントの運転停止中の電池保管状態にお
いて、アノード電極１ａおよびカソード電極１ｂの直前
の入口側に配置したアノード入口遮断弁２８およびカソ
ード入口遮断弁２９をそれぞれ全閉し、かつこのアノー
ド入口遮断弁２８，カソード入口遮断弁２９の下流側
で、アノード電極１ａおよびカソード電極１ｂの入口側
に配置した乾燥Ｎ₂ ガス供給制御弁２２および２３に開
信号を与えるようにしているので、アノード電極１ａお
よびカソード電極１ｂに乾燥Ｎ₂ ガスを連続的または間
欠的に供給して、アノード電極１ａおよびカソード電極
１ｂを乾燥Ｎ₂ ガス雰囲気に維持することができるた
め、外部の空気が燃料電池本体内へ混入することを防止
することが可能となる。As described above, in the present embodiment, the anode inlet cutoff valve 28 disposed on the inlet side immediately before the anode electrode 1a and the cathode electrode 1b is in the battery storage state while the phosphoric acid fuel cell power plant is stopped. And the cathode inlet cutoff valve 29 are fully closed, and the dry N ₂ gas supply control valve is arranged on the downstream side of the anode inlet cutoff valve 28 and the cathode inlet cutoff valve 29 and on the inlet side of the anode electrode 1a and the cathode electrode 1b. Since an open signal is given to the electrodes 22 and 23, the dry N ₂ gas is continuously or intermittently supplied to the anode electrode 1a and the cathode electrode 1b so that the anode electrode 1a and the cathode electrode 1b are in a dry N ₂ gas atmosphere. Therefore, it is possible to prevent external air from being mixed into the fuel cell main body.

【００６６】これにより、燃料電池本体中のリン酸が外
部の空気の湿分を吸収し、リン酸の体積増大に伴う、リ
ン酸の燃料電池本体外への漏洩を回避し、それによるシ
ール機能の不良、電解質減少に伴うイオン伝導性の低下
を防止することができる。As a result, the phosphoric acid in the fuel cell body absorbs moisture from the outside air, and the phosphoric acid is prevented from leaking to the outside of the fuel cell body due to the increase in the volume of phosphoric acid. It is possible to prevent the deterioration of ion conductivity due to the deterioration of the electrolyte and the decrease of the electrolyte.

【００６７】また、上記リン酸の体積変化に伴う、リン
酸移動で生じる触媒層を含めた多孔質体の細孔部に所定
以上のリン酸が侵入してしまうフラッディング現象をも
抑制することができる。Further, it is possible to suppress the flooding phenomenon in which phosphoric acid of a predetermined amount or more enters the pores of the porous body including the catalyst layer, which is caused by the phosphoric acid migration due to the change in the phosphoric acid volume. it can.

【００６８】さらに、混入空気中の酸素（Ｏ₂ ）が電極
に吸着して高電位（約１Ｖ）状態が保持される場合に、
電気的吸引力によるリン酸の移動に伴う、触媒層を含め
た多孔質体の細孔部に所定以上のリン酸が侵入してしま
うフラッディング現象を抑制することができる。Further, when oxygen (O ₂ ) in the mixed air is adsorbed on the electrode and a high potential (about 1 V) is maintained,
It is possible to suppress the flooding phenomenon in which phosphoric acid of a predetermined amount or more enters the pores of the porous body including the catalyst layer due to the movement of phosphoric acid due to the electric attraction force.

【００６９】一方、リン酸型燃料電池発電プラントの運
転停止中の電池保管状態において、燃料電池本体の交流
抵抗を検出し、その交流抵抗の値が所定の管理値を逸脱
した場合に、燃料電池本体内に空気が混入した状態と判
断して、アノード電極１ａに乾燥水素を供給すること
で、燃料電池本体内の各冷却板３間の電圧発生状況を検
出する。そして、この時、燃料電池本体の全体、または
任意の冷却板３間で局部的に電池電圧が所定値以上発生
している場合には、上記電圧発生の冷却板３間に電圧抑
制抵抗３５を介して電気的短絡回路を形成させるように
しているので、所定値以上の電圧発生部分の電力は、電
圧抑制抵抗３５によって消費され（カソード電極１ｂの
酸素（Ｏ₂ ）が電気化学反応で消費され）、燃料電池本
体の電圧を所定値内に管理することが可能となる。On the other hand, when the AC resistance of the fuel cell body is detected and the value of the AC resistance deviates from a predetermined control value while the phosphoric acid fuel cell power plant is in the storage state while the operation is stopped, the fuel cell It is determined that air is mixed in the main body, and dry hydrogen is supplied to the anode electrode 1a to detect the voltage generation state between the cooling plates 3 in the fuel cell body. At this time, when the cell voltage locally exceeds the predetermined value over the entire fuel cell body or between the arbitrary cooling plates 3, the voltage suppressing resistor 35 is provided between the cooling plates 3 for generating the voltage. Since the electric short circuit is formed via the electric power, the electric power of the voltage generation portion of the predetermined value or more is consumed by the voltage suppression resistor 35 (oxygen (O ₂ ) of the cathode electrode 1b is consumed by the electrochemical reaction). ), The voltage of the fuel cell main body can be managed within a predetermined value.

【００７０】これにより、仮に燃料電池本体内に外部の
空気中の酸素（Ｏ₂ ）が混入した場合でも、速やかにそ
の状態を検知して、酸素（Ｏ₂ ）消費除去操作を実施で
きるため、前述した電極高電位状態で起きるフラッディ
ング現象に至るようなことがなく、燃料電池本体を安全
に保管することができる。As a result, even if oxygen (O ₂ ) in the outside air is mixed into the fuel cell main body, the state can be immediately detected and the oxygen (O ₂ ) consumption removing operation can be carried out. The flooding phenomenon that occurs in the high electrode potential state described above does not occur, and the fuel cell body can be safely stored.

【００７１】以上の結果、長期間にわたる電池保管にお
いても、電池特性を低下させることなく、極めて信頼性
の高いリン酸型燃料電池発電プラントを得ることが可能
となる。As a result of the above, it is possible to obtain a highly reliable phosphoric acid fuel cell power generation plant without degrading the battery characteristics even when the battery is stored for a long period of time.

【００７２】次に、本実施例の効果について、さらに詳
細に説明する。すなわち、リン酸型燃料電池発電プラン
トの運転停止中の電池保管中に、燃料電池本体のアノー
ド電極２ａおよびカソード電極１ｂに乾燥Ｎ₂ ガスを連
続的または間欠的に供給して、アノード電極１ａおよび
カソード電極１ｂを乾燥Ｎ₂ ガス雰囲気に維持すること
ができるため、外部から空気が燃料電池本体内へ侵入す
るのを防止することができる。Next, the effect of this embodiment will be described in more detail. That is, during storage of the cell while the phosphoric acid fuel cell power plant is stopped, the dry N ₂ gas is continuously or intermittently supplied to the anode electrode 2a and the cathode electrode 1b of the fuel cell main body so that the anode electrode 1a and Since the cathode electrode 1b can be maintained in a dry N ₂ gas atmosphere, it is possible to prevent air from entering the fuel cell main body from the outside.

【００７３】この結果、燃料電池本体中のリン酸が外部
の空気の湿分を吸収し、リン酸の体積増大に伴う、リン
酸の燃料電池本体外への漏洩を回避し、それによるシー
ル機能の不良、電解質減少に伴うイオン伝導性の低下を
防止することができる。As a result, the phosphoric acid in the fuel cell main body absorbs the moisture of the outside air, and the leakage of phosphoric acid to the outside of the fuel cell main body due to the increase in the volume of phosphoric acid is avoided, and the sealing function by this is avoided. It is possible to prevent the deterioration of ion conductivity due to the deterioration of the electrolyte and the decrease of the electrolyte.

【００７４】また、上記リン酸の体積変化に伴う、リン
酸移動で生じる触媒層を含めた多孔質体の細孔部に所定
以上のリン酸が侵入してしまうフラッディング現象をも
抑制することができる。Further, it is possible to suppress the flooding phenomenon in which phosphoric acid of a predetermined amount or more enters into the pores of the porous body including the catalyst layer, which is caused by the phosphoric acid migration due to the volume change of the phosphoric acid. it can.

【００７５】さらに、混入空気中の酸素（Ｏ₂ ）が、電
極に吸着して高電位（約１Ｖ）状態に保持される場合
に、電気的吸引力によるリン酸の移動に伴う、触媒層を
含めた多孔質体の細孔部に所定以上のリン酸が侵入して
しまうフラッディング現象を抑制することができる。Further, when oxygen (O ₂ ) in the mixed air is adsorbed on the electrode and is kept at a high potential (about 1 V), the catalyst layer is formed along with the movement of phosphoric acid due to the electric attraction force. It is possible to suppress the flooding phenomenon in which phosphoric acid of a predetermined amount or more enters the pores of the porous body including the porous body.

【００７６】一方、リン酸型燃料電池発電プラントの運
転停止中の電池保管中に、燃料電池本体の交流抵抗を検
出し、その交流抵抗値が所定の管理値を逸脱した場合
に、燃料電池本体内に空気が混入状態と判断し、アノー
ド電極１ａに乾燥水素を供給することで、燃料電池本体
内の各冷却板３間の電圧発生状況を検出し、この時、燃
料電池本体の全体、または任意の冷却板３間で局部的に
電池電圧が所定値以上発生している場合には、上記電圧
発生の冷却板３間に電圧抑制抵抗３５を介して電気的短
絡回路を形成して、所定値以上の電圧発生部分の電力
を、電圧抑制抵抗３５により消費させ（カソード電極１
ｂの酸素（Ｏ₂ ）を電気化学反応で消費させ）、燃料電
池本体の電圧を所定値内に管理することができる。On the other hand, when the AC resistance of the fuel cell main body is detected during storage of the cell while the operation of the phosphoric acid fuel cell power plant is stopped and the AC resistance value deviates from a predetermined control value, the fuel cell main body It is determined that air is mixed in the air, and by supplying dry hydrogen to the anode electrode 1a, the voltage generation state between the cooling plates 3 in the fuel cell main body is detected. When the battery voltage is locally generated between the arbitrary cooling plates 3 by a predetermined value or more, an electrical short circuit is formed between the cooling plates 3 for generating the voltage via the voltage suppressing resistor 35 to set the predetermined voltage. The electric power of the voltage generation portion equal to or more than the value is consumed by the voltage suppression resistor 35 (the cathode electrode
It is possible to manage the voltage of the fuel cell main body within a predetermined value by consuming oxygen (O ₂ ) of b in the electrochemical reaction).

【００７７】この結果、仮に燃料電池本体内に外部の空
気中の酸素（Ｏ₂ ）が混入した場合でも、速やかにその
状態を検知し、Ｏ₂ 消費除去操作を実施できるので、前
述した電極高電位状態で起きるフラッディング現象に至
ることなく、燃料電池本体を安全に保管することができ
る。以上により、長期間にわたる電池保管においても、
電池特性を低下させることなく、極めて信頼性の高いリ
ン酸型燃料電池発電プラントを得ることができる。As a result, even if oxygen (O ₂ ) in the outside air is mixed into the fuel cell main body, the state can be quickly detected and the O ₂ consumption removing operation can be carried out. The fuel cell main body can be safely stored without reaching the flooding phenomenon that occurs in the potential state. Due to the above, even when storing batteries for a long time,
An extremely highly reliable phosphoric acid fuel cell power plant can be obtained without degrading the cell characteristics.

【００７８】[0078]

【発明の効果】以上説明したように本発明によれば、燃
料極および酸化剤極の入口側ラインにそれぞれ配置さ
れ、リン酸型燃料電池発電プラント本体の運転停止中の
電池保管時に全閉される遮断弁と、燃料極側の遮断弁と
燃料極との間、および酸化剤極側の遮断弁と酸化剤極と
の間にそれぞれ接続され、燃料極および酸化剤極に乾燥
不活性ガスをそれぞれ供給する乾燥不活性ガス供給ライ
ンと、さらに各乾燥不活性ガス供給ラインにそれぞれ配
置され、燃料電池発電プラント本体の運転停止中の電池
保管時に開制御される第１の供給制御弁と、燃料極側の
遮断弁と燃料極との間に接続され、燃料極に水素を含む
乾燥ガスを供給する乾燥ガス供給ラインと、乾燥ガス供
給ラインに配置された第２の供給制御弁と、燃料電池発
電プラント本体の運転停止中の電池保管時における燃料
電池本体の交流抵抗を測定する交流抵抗検出手段と、燃
料電池本体の発生電圧を測定する電圧検出手段と、交流
抵抗検出手段により測定された交流抵抗の値があらかじ
め定められた管理値以下になった場合に、第２の供給制
御弁を開制御すると共に、当該第２の供給制御弁の開制
御時に電圧検出手段により測定された電池電圧が所定値
以上になった場合に、燃料電池本体の燃料極と酸化剤極
との間を電圧抑制抵抗を介して電気的に短絡するように
制御する電圧抑制制御手段とを備えるようにしたので、
リン酸型燃料電池発電プラントの運転停止中の電池保管
状態における燃料電池本体内のリン酸移動を最小限に抑
えて、リン酸を所定の位置に保持管理することができ、
もって長期間の保管においても電池特性を低下させるこ
となく安定に維持することが可能なリン酸型燃料電池発
電プラントおよびその保管方法が提供できる。As described above, according to the present invention, the fuel cell and the oxidant electrode are arranged at the inlet side lines, respectively, and are fully closed during storage of the battery while the phosphoric acid fuel cell power plant main body is out of operation. Shut-off valve and the shut-off valve on the fuel electrode side, and between the shut-off valve on the fuel electrode side and the shut-off valve on the oxidant electrode side and the oxidant electrode, respectively. A dry inert gas supply line for supplying each of them, a first supply control valve which is arranged on each of the dry inert gas supply lines, and which is controlled to be opened when the battery is stored while the fuel cell power plant main body is not operating, A dry gas supply line connected between the shutoff valve on the electrode side and the fuel electrode to supply a dry gas containing hydrogen to the fuel electrode; a second supply control valve arranged in the dry gas supply line; and a fuel cell Power plant body luck AC resistance detection means for measuring the AC resistance of the fuel cell body during storage of the battery while stopped, voltage detection means for measuring the generated voltage of the fuel cell body, and the value of the AC resistance measured by the AC resistance detection means in advance When the control value becomes equal to or lower than the predetermined control value, the second supply control valve is controlled to be opened, and the battery voltage measured by the voltage detecting means during the control of opening the second supply control valve is equal to or higher than the predetermined value. In this case, since the voltage suppression control means for controlling the fuel electrode and the oxidizer electrode of the fuel cell main body to electrically short-circuit via the voltage suppression resistance is provided,
It is possible to minimize the movement of phosphoric acid in the fuel cell body during storage of the cell during operation of the phosphoric acid fuel cell power plant while keeping the phosphoric acid in place and manage it.
Therefore, it is possible to provide a phosphoric acid fuel cell power generation plant and a storage method thereof, which can stably maintain the cell characteristics without deteriorating even during long-term storage.

[Brief description of drawings]

【図１】本発明のリン酸型燃料電池発電プラントの一実
施例を示すブロック図。FIG. 1 is a block diagram showing an embodiment of a phosphoric acid fuel cell power generation plant of the present invention.

【図２】同実施例のリン酸型燃料電池プラントにおける
燃料電池本体冷却板の電気回路の構成例を示す拡大図。FIG. 2 is an enlarged view showing a configuration example of an electric circuit of a fuel cell body cooling plate in the phosphoric acid fuel cell plant of the embodiment.

【図３】同実施例のリン酸型燃料電池プラントにおける
電池保管中の交流抵抗の変化の一例を示す特性図。FIG. 3 is a characteristic diagram showing an example of changes in AC resistance during battery storage in the phosphoric acid fuel cell plant of the same example.

【図４】リン酸型燃料電池本体の構成例を示す分解斜視
図図。FIG. 4 is an exploded perspective view showing a configuration example of a phosphoric acid fuel cell main body.

【図５】燃料電池本体の冷却板の構成例を示す拡大図。FIG. 5 is an enlarged view showing a configuration example of a cooling plate of the fuel cell body.

【図６】従来のリン酸型燃料電池発電プラントの構成例
を示すブロック図。FIG. 6 is a block diagram showing a configuration example of a conventional phosphoric acid fuel cell power generation plant.

【図７】リン酸型燃料電池の発電プラントの起動停止特
性の一例を示す特性図。FIG. 7 is a characteristic diagram showing an example of start / stop characteristics of a power plant of a phosphoric acid fuel cell.

[Explanation of symbols]

１…単位セル、２０…乾燥Ｎ₂ ガス供給ライン、２１…
乾燥Ｎ₂ ガス供給ライン、２２…供給制御弁、２３…供
給制御弁、２６…乾燥水素供給ライン、２７…供給制御
弁、２８…アノード入口遮断弁、２９…カソード入口遮
断弁、３０…交流抵抗検出器、３１…電圧抑制制御装
置、３２…電圧測定線、３３…電圧検出器、３４…電気
的導線、３５…電圧抑制抵抗、３６…電気的短絡回路。1 ... Unit cell, 20 ... Dry N ₂ gas supply line, 21 ...
Dry N ₂ gas supply line, 22 ... Supply control valve, 23 ... Supply control valve, 26 ... Dry hydrogen supply line, 27 ... Supply control valve, 28 ... Anode inlet cutoff valve, 29 ... Cathode inlet cutoff valve, 30 ... AC resistance Detector, 31 ... Voltage suppression control device, 32 ... Voltage measurement line, 33 ... Voltage detector, 34 ... Electrical lead wire, 35 ... Voltage suppression resistor, 36 ... Electrical short circuit.

Claims

[Claims]

1. A unit cell is formed by arranging a fuel electrode and an oxidant electrode with an electrolyte layer impregnated with an electrolyte interposed therebetween, and a separator or a cooling pipe for circulating a refrigerant therein is embedded in the unit cell. By forming a plurality of fuel cell bodies by laminating a plurality of cooling plates through the cooling plate, and supplying the fuel gas and the oxidant to the fuel electrode and the oxidant electrode, respectively,
In a method of storing a phosphoric acid fuel cell power plant that obtains an electric output by an electrochemical reaction that occurs at this time, the fuel electrode and the oxidizer are stored when the battery is stored while the phosphoric acid fuel cell power plant is stopped. A method for storing a phosphoric acid fuel cell power plant, characterized in that a dry inert gas is continuously or intermittently supplied to at least one of the electrodes.

2. A unit cell is formed by arranging a fuel electrode and an oxidizer electrode with an electrolyte layer impregnated with an electrolyte sandwiched therebetween, and a separator or a cooling pipe for circulating a refrigerant therein is embedded in the unit cell. By forming a plurality of fuel cell bodies by laminating a plurality of cooling plates through the cooling plate, and supplying the fuel gas and the oxidant to the fuel electrode and the oxidant electrode, respectively,
In a method of storing a phosphoric acid fuel cell power generation plant that obtains an electric output by an electrochemical reaction that occurs at this time, in storing a battery while the phosphoric acid fuel cell power generation plant is stopped, an alternating current of the fuel cell main body The resistance is measured and its change over time is monitored, and when the value of the AC resistance falls below a predetermined control value, a dry gas containing hydrogen is supplied to the fuel electrode to generate the voltage of the fuel cell body. And when the measured cell voltage exceeds a predetermined value, the fuel electrode of the fuel cell body and the oxidizer electrode are electrically short-circuited via a voltage suppression resistor. A method for storing a phosphoric acid fuel cell power plant, comprising:

3. A unit cell is formed by arranging a fuel electrode and an oxidizer electrode with an electrolyte layer impregnated with an electrolyte interposed therebetween, and the unit cell is embedded with a separator or a cooling pipe for circulating a refrigerant therein. By forming a plurality of fuel cell bodies by laminating a plurality of cooling plates through the cooling plate, and supplying the fuel gas and the oxidant to the fuel electrode and the oxidant electrode, respectively,
In a method of storing a phosphoric acid fuel cell power plant that obtains an electric output by an electrochemical reaction that occurs at this time, the fuel electrode and the oxidizer are stored when the battery is stored while the phosphoric acid fuel cell power plant is stopped. A dry inert gas is continuously or intermittently supplied to at least one of the electrodes, and the AC resistance of the fuel cell body is measured during storage of the battery while the fuel cell power plant is stopped. Then, the change over time is monitored, and when the value of the AC resistance becomes equal to or lower than a predetermined control value, a dry gas containing hydrogen is supplied to the fuel electrode to measure the generated voltage of the fuel cell body, And, when the measured cell voltage exceeds a predetermined value, the fuel electrode and the oxidant electrode of the fuel cell body are electrically short-circuited via a voltage suppression resistor. Method for storing a phosphoric acid fuel cell power plant, characterized in that it has.

4. A voltage suppressing resistor is inserted into a portion of the fuel cell main body where an excessive voltage is generated when the cell voltage of the fuel cell main body exceeds a predetermined value. The method for storing a phosphoric acid fuel cell power plant according to claim 2.

5. The voltage between the respective cooling plates of the fuel cell body is measured, and any cooling plate whose voltage has become a predetermined value or more is electrically short-circuited via a voltage suppressing resistor. The method for storing a phosphoric acid fuel cell power plant according to claim 4, characterized in that.

6. A unit cell is formed by arranging a fuel electrode and an oxidizer electrode with an electrolyte layer impregnated with an electrolyte interposed therebetween, and a separator or a cooling pipe for circulating a refrigerant therein is embedded in the unit cell. By forming a plurality of fuel cell bodies by laminating a plurality of cooling plates through the cooling plate, and supplying the fuel gas and the oxidant to the fuel electrode and the oxidant electrode, respectively,
In a phosphoric acid fuel cell power plant that is configured to obtain an electrical output by an electrochemical reaction that occurs at this time, the fuel cell power plant main unit is placed in the inlet side line of the fuel electrode and the oxidant electrode, respectively, and A shutoff valve that is fully closed during storage of the battery, a shutoff valve on the fuel electrode side and a fuel electrode, and a shutoff valve on the oxidant electrode side and an oxidant electrode, respectively,
A dry inert gas supply line for supplying a dry inert gas to the fuel electrode and the oxidizer electrode, respectively, and arranged respectively in the dry inert gas supply line,
A phosphoric acid fuel cell power plant, comprising: a supply control valve that is controlled to be opened when the battery is stored while the main body of the phosphoric acid fuel cell power plant is stopped.

7. A unit cell is formed by arranging a fuel electrode and an oxidizer electrode with an electrolyte layer impregnated with an electrolyte interposed therebetween, and the unit cell is embedded with a separator or a cooling pipe for circulating a refrigerant therein. By forming a plurality of fuel cell bodies by laminating a plurality of cooling plates through the cooling plate, and supplying the fuel gas and the oxidant to the fuel electrode and the oxidant electrode, respectively,
In a phosphoric acid fuel cell power generation plant configured to obtain an electrical output by an electrochemical reaction that occurs at this time, a dry gas containing hydrogen is connected to the fuel electrode and is connected between the shutoff valve on the fuel electrode side and the fuel electrode. A dry gas supply line to be supplied, a supply control valve arranged in the dry gas supply line, and an AC resistance of the fuel cell main body during battery storage during operation stop of the phosphoric acid fuel cell power plant main body is measured. AC resistance detection means, voltage detection means for measuring the generated voltage of the fuel cell main body, and when the value of the AC resistance measured by the AC resistance detection means is below a predetermined management value, the supply When the control valve is controlled to be opened, and when the battery voltage measured by the voltage detection means becomes equal to or higher than a predetermined value when the second supply control valve is controlled to be opened, A phosphoric acid fuel cell power generation, comprising: voltage suppression control means for controlling an electrical short circuit between a fuel electrode and an oxidizer electrode of a fuel cell body via a voltage suppression resistor. plant.

8. A unit cell is constructed by arranging a fuel electrode and an oxidizer electrode with an electrolyte layer impregnated with an electrolyte interposed therebetween, and the unit cell is embedded with a separator or a cooling pipe for circulating a refrigerant therein. By forming a plurality of fuel cell bodies by laminating a plurality of cooling plates through the cooling plate, and supplying the fuel gas and the oxidant to the fuel electrode and the oxidant electrode, respectively,
In a phosphoric acid fuel cell power plant that is configured to obtain an electric output by an electrochemical reaction that occurs at this time, the fuel cell power plant main unit is placed in the inlet side lines of the fuel electrode and the oxidizer electrode, respectively, and A shutoff valve that is fully closed during storage of the battery, a shutoff valve on the fuel electrode side and a fuel electrode, and a shutoff valve on the oxidant electrode side and an oxidant electrode, respectively,
A dry inert gas supply line for supplying a dry inert gas to the fuel electrode and the oxidizer electrode, respectively, and arranged respectively in the dry inert gas supply line,
A first supply control valve, which is controlled to be opened when the cell is stored while the phosphoric acid fuel cell power plant main body is out of operation, is connected between the shutoff valve on the fuel electrode side and the fuel electrode, and is connected to the fuel electrode. A dry gas supply line for supplying a dry gas containing hydrogen; a second supply control valve arranged on the dry gas supply line; and a battery storage state during operation stop of the phosphoric acid fuel cell power plant main body AC resistance detection means for measuring the AC resistance of the fuel cell main body, voltage detection means for measuring the generated voltage of the fuel cell main body, the value of the AC resistance measured by the AC resistance detection means is a predetermined management value When the following condition is met, the second supply control valve is controlled to be opened, and the battery voltage measured by the voltage detecting means during the opening control of the second supply control valve is equal to or higher than a predetermined value. And a voltage suppression control means for controlling so as to electrically short-circuit the fuel electrode and the oxidizer electrode of the fuel cell main body through a voltage suppression resistor. Fuel cell power plant.

9. The voltage suppression control means controls so that when the cell voltage of the fuel cell main body exceeds a predetermined value, a voltage suppression resistor is turned on to an excessive voltage generation portion in the fuel cell main body. The phosphoric acid fuel cell power plant according to claim 7 or 8, characterized in that.

10. The voltage suppression control means measures the voltage between the respective cooling plates of the fuel cell main body, and electrically connects between the arbitrary cooling plates whose voltage exceeds a predetermined value via a voltage suppression resistor. The phosphoric acid fuel cell power plant according to claim 9, wherein the phosphoric acid fuel cell power plant is controlled so as to be electrically short-circuited.

11. A voltage measuring circuit for connecting a voltage measuring signal line and an electric conducting wire to a cooling pipe embedded in each cooling plate to measure a voltage between each cooling plate and an arbitrary cooling plate. The phosphoric acid fuel cell power plant according to claim 10, further comprising an electric circuit electrically short-circuited via a voltage suppression resistor.