JP4552387B2

JP4552387B2 - Fuel cell cogeneration system

Info

Publication number: JP4552387B2
Application number: JP2003133071A
Authority: JP
Inventors: 敬澤田
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2003-05-12
Filing date: 2003-05-12
Publication date: 2010-09-29
Anticipated expiration: 2023-05-12
Also published as: JP2004335402A

Description

【０００１】
【発明の属する技術分野】
本発明は、燃料電池の発電時に発生する熱を回収して給湯および暖房に利用する燃料電池コージェネレーション装置に関するものである。
【０００２】
【従来の技術】
従来、この種の燃料電池コージェネレーション装置としては、例えば、図１１に示すようなものがある。
【０００３】
図１１は、従来の燃料電池コージェネレーション装置の構成図であり、１は燃料電池で、酸素極２に空気と燃料極３に水素ガスなどの燃料ガスを供給して発電した電力を電力負荷４に供給する。５は冷却熱回収熱交換器で、冷却回路６の冷却ポンプ７で冷却水を循環して燃料電池１の冷却部８から熱を得て貯湯循環回路９に放熱する。１０は貯湯槽で、循環ポンプ１１で貯湯槽１０の下部の低温水を冷却熱回収熱交換器５に送って加熱し高温になった温水を貯湯槽１０の上部に蓄える。１２は熱交換器で、冷却回路６に設けた３方切換手段１３で分岐した冷却バイパス回路１４に設けて燃料電池１の発生熱を放熱する。１５は制御器で、貯湯循環回路９の蓄熱槽１０の戻り側に設けた温度検出手段１６の検知温度に応じて循環ポンプ１１の循環量を制御して蓄熱槽１０の上部に入る温水の温度を所定の温度になるように制御する（例えば、特許文献１参照）。
【０００４】
【特許文献１】
特開２０００−３４０２４４号公報
【０００５】
【発明が解決しようとする課題】
しかしながら、前記従来の構成では、燃料電池を起動させるためには外部から加熱する必要がありエネルギー効率が悪く、起動時間が長くなるなどの課題を有していた。
【０００６】
本発明は、前記従来の課題を解決するもので、貯湯循環回路に貯湯バイパス回路を設けて燃料電池の起動時に貯湯槽の温度成層を崩すことなくシステム内で発生する熱で燃料電池を加熱起動してエネルギー効率を高め、起動時間を短縮することを目的とする。
【０００７】
【課題を解決するための手段】
前記従来の課題を解決するために、本発明の燃料電池コージェネレーション装置は、貯湯槽と循環ポンプと燃料電池の冷却回路に設けた冷却熱回収熱交換器と水素製造装置の排気熱を回収する排気ガス熱回収熱交換器とを順に配管接続して構成する貯湯循環回路と、前記貯湯循環回路内で貯湯槽をバイパスする貯湯バイパス回路と、前記貯湯バイパス回路を切換る回路切換手段と、燃料電池の温度検知手段と、前記温度検出手段の信号に応じて前記燃料電池の温度が所定の温度に達していない場合は前記貯湯循環回路内で貯湯槽をバイパスして前記貯湯バイパス回路に循環水が流れ前記燃料電池の温度が所定の温度以上になると前記貯湯槽に循環水が流れるように前記回路切換手段を切換る制御装置とを設けた構成としたものである。
【０００８】
これによって、燃料電池の起動時は貯湯循環回路の温水を貯湯槽を通さずに貯湯バイパス回路に流すことができるので、低温の水を貯湯槽の上部に入れて温度成層を崩すことなく排気ガスなどのシステムで発生する熱をシステム熱回収熱交換器で回収して冷却熱回収熱交換器を介して燃料電池を加熱することができる。
【０００９】
【発明の実施の形態】
請求項１に記載した発明は、貯湯槽と循環ポンプと燃料電池の冷却回路に設けた冷却熱回収熱交換器と水素製造装置の排気熱を回収する排気ガス熱回収熱交換器とを順に配管接続して構成する貯湯循環回路と、前記貯湯循環回路内で貯湯槽をバイパスする貯湯バイパス回路と、前記貯湯バイパス回路を切換る回路切換手段と、燃料電池の温度検知手段と、前記温度検出手段の信号に応じて前記燃料電池の温度が所定の温度に達していない場合は前記貯湯循環回路内で貯湯槽をバイパスして前記貯湯バイパス回路に循環水が流れ前記燃料電池の温度が所定の温度以上になると前記貯湯槽に循環水が流れるように前記回路切換手段を切換る制御装置とを設けた構成とすることにより、燃料電池の温度検知手段が所定の値に達していない場合は、制御器で回路切換手段を貯湯バイパス回路に切換て、貯湯槽を通さずに貯湯循環回路の温水を循環することにより、貯湯槽の上部に低温の水がはいるのを防止して温度成層が崩れるのを防ぐことができ、システム熱回収熱交換器で得た熱を冷却熱回収熱交換器を介して燃料電池を加熱して燃料電池の温度を上げることができるので燃料電池の起動時間を短縮することができる。
【００１０】
請求項２に記載の発明は、特に、請求項１に記載の燃料電池コージェネレーション装置における回路切換手段を、貯湯槽出口に設けた逆止弁と、貯湯循環回路のバイパス分岐部に設けた３方切換手段とで構成することにより、回路切換のための制御電力を低減して確実に回路を切換ることができるので、高効率で信頼性の高い燃料電池コージェネレーション装置を実現することができる。
【００１１】
請求項３に記載の発明は、特に、請求項１又は２に記載の燃料電池コージェネレーション装置に加えて、貯湯バイパス回路に設けた補助熱源と、貯湯循環回路の貯湯槽入口に設けた貯湯温度検知手段とを有し、制御手段は、燃料電池の温度が所定の温度に達するまでは前記貯湯バイパス回路を流れる循環水を前記補助熱源により加熱し、前記燃料電池の温度が所定の温度以上になり前記回路切換手段により貯湯槽に循環水が流れるようにした後は、前記貯湯温度検知手段の信号に応じて貯湯槽入口の温度が所定の温度になるように前記回路切換手段により前記貯湯バイパス回路を流れる流量と前記補助熱源の加熱量を制御する構成とすることにより、貯湯槽に所定の温水が蓄えられていないときは貯湯バイパス回路に設けた補助熱源で加熱して貯湯槽に蓄えて給湯し、燃料電池の起動時は貯湯バイパス回路の補助熱源で加熱した循環水を冷却熱回収熱交換器に流して燃料電池を加熱することができるので、補助熱源によって安定した給湯を行うことができるとともに燃料電池の起動時間を大幅に短縮することができる。
【００１２】
請求項４に記載の発明は、特に、請求項３に記載の燃料電池コージェネレーション装置に加えて、貯湯バイパス回路の補助熱源の出口に設けた第２貯湯槽を有する構成とすることにより、燃料電池の動作温度より高い温度の温水を第２貯湯槽に蓄えることができるので、燃料電池の起動時に第２貯湯槽から大量の熱を取り出して冷却熱回収熱交換器を介して燃料電池を加熱することができるので燃料電池の起動時間を大幅に短縮することができる。さらに、第２貯湯槽には常に高温の温水をためておくことができるので貯湯槽内の温水が不足した場合でも安定して給湯することができる。
【００１３】
請求項５に記載の発明は、特に、請求項４に記載の燃料電池コージェネレーション装置に加えて、貯湯バイパス回路の補助熱源の出口から分岐して給湯配管を設けた構成とすることにより、補助熱源で温水を任意の温度に加熱して給湯することができる。
【００１４】
請求項６に記載の発明は、特に、請求項1から５に記載の燃料電池コージェネレーション装置に加えて、貯湯バイパス回路の補助熱源の下流に暖房用および乾燥用の放熱器を有する熱利用熱交換器を設けた構成とすることにより、燃料電池で発生する熱を暖房および乾燥などに使用することができる。また、燃料電池で発生する熱が不足する場合は補助熱源で補うことができるので経済的で安定した暖房運転ができる。
【００１５】
請求項７に記載の発明は、特に、請求項1に記載の燃料電池コージェネレーション装置に加えて、貯湯循環回路の貯湯槽入口に設けた補助熱源と、貯湯槽に設けた貯湯量検知手段とを有し、制御手段は、前記貯湯量検知手段により前記貯湯槽に所定量の湯水が貯まったことを検知するまで前記貯湯循環回路を循環する循環水を補助熱源で加熱する構成としたもので、貯湯槽に設けた貯湯量検知手段が所定の値を検知するまで貯湯循環回路を循環する温水を補助熱源で加熱するように制御装置で制御することにより、燃料電池の運転状態に拘わらず常に一定の温水を貯湯槽に蓄えることができるので、湯切れの無い安定した給湯運転ができる。
【００１６】
請求項８に記載の発明は、特に、請求項７に記載の燃料電池コージェネレーション装置に加えて、貯湯循環回路の貯湯槽入口に設けた温度検知手段と、前記貯湯循環回路の補助熱源の下流で前記貯湯槽入口に設けた温度検知手段の上流に設けた暖房用および乾燥用の放熱器を有する熱利用熱交換器とを有し、制御手段は、前記温度検出手段の検出値が所定の値になるように前記補助熱源の加熱量を制御する構成としたもので、貯湯循環回路に設けた冷却熱回収熱交換器と排気ガス熱回収熱交換器で得た熱を熱利用熱交換器で放熱して暖房および乾燥用の放熱器で利用することができる。また燃料電池が停止している場合や熱利用熱交換器の出口温度が所定の値より低くなる場合は、貯湯温度検出手段の検出値が所定の値になるように制御装置で補助熱源を制御することにより、暖房および乾燥運転に安定して対応できるとともに、貯湯槽内の温度を所定の値に保つことができる。
【００１７】
請求項９に記載の発明は、貯湯槽と循環ポンプと燃料電池の冷却回路に設けた冷却熱回収熱交換器と水素製造装置の排気熱などを回収する排気ガス熱回収熱交換器とを順に配管接続して構成する貯湯循環回路と、一方を貯湯槽の下部出口と循環ポンプの吸入側と接続し他方を循環ポンプの吐出側と貯湯槽の上部入口を接続し、切換時には、一方を貯湯槽の下部出口と貯湯槽の上部入口を接続し他方を循環ポンプ吐出側と循環ポンプの吸入側とを接続する４方切換手段と、燃料電池の温度検出手段と、前記温度検出手段の検出値に応じて前記燃料電池の温度が所定の温度に達していない場合は一方を前記貯湯槽の下部出口と前記貯湯槽の上部入口を接続し他方を前記循環ポンプ吸入側と前記循環ポンプの吐出側とを接続し前記燃料電池の温度が所定の温度以上になると一方を前記貯湯槽の下部出口と前記循環ポンプの吸入側と接続し他方を前記循環ポンプの吐出側と前記貯湯槽の上部入口を接続するように前記４方切換手段を切換制御する制御装置とを設けた構成としたもので、燃料電池の温度検出手段の検出値が所定の値より低い場合は、４方切換手段で循環ポンプ吐出側と循環ポンプの吸入側とを接続して、貯湯槽の上部入口に低温の水が入らないようにするとともにシステム熱回収熱交換器で得た熱を冷却熱交換器を介して燃料電池に放熱するように制御器で制御することにより、簡単な構造で、貯湯槽の温度成層を崩さずに起動時に燃料電池を加熱することができる。
【００１８】
請求項１０に記載の発明は、貯湯槽と循環ポンプと燃料電池の冷却回路に設けた冷却熱回収熱交換器と水素製造装置の排気熱などを回収する排気ガス熱回収熱交換器とを順に配管接続して構成する貯湯循環回路と、一方を貯湯槽の下部出口と循環ポンプの吸入側と接続し他方を循環ポンプの吐出側と貯湯槽の上部入口を接続し、切換時には、一方を貯湯槽の下部出口と循環ポンプ吐出側を接続し他方を貯湯槽の上部入口と循環ポンプの吸入側とを接続する４方切換手段と、燃料電池の温度検出手段と、前記温度検出手段の検出値に応じて前記燃料電池の温度が所定の温度に達していない場合は一方を前記貯湯槽の下部出口と前記循環ポンプ吐出側を接続し他方を前記貯湯槽の上部入口と前記循環ポンプの吸入側とを接続し前記燃料電池の温度が所定の温度以上になると一方を前記貯湯槽の下部出口と前記循環ポンプの吸入側と接続し他方を前記循環ポンプの吐出側と前記貯湯槽の上部入口を接続するように前記４方切換手段を切換制御する制御装置とを設けた構成としたもので、燃料電池の温度検出手段の検出値が所定の値より低い場合は、４方切換手段で一方を貯湯槽の下部出口と循環ポンプ吐出側を接続し他方を貯湯槽の上部入口と循環ポンプの吸入側とを接続して、貯湯槽上部の高温の温水を冷却熱交換器におくって燃料電池を加熱するように制御器で制御することにより、簡単な構造で、貯湯槽の熱を利用して燃料電池を加熱することができる。
【００１９】
【実施例】
以下、本発明の実施例について、図面を参照しながら説明する。
【００２０】
（実施例１）
図１は本実施例の第１の実施例における燃料電池コージェネレーション装置の構成図を示すものである。
【００２１】
図１において、１は固体高分子膜を用いた燃料電池で、酸素極２に空気と燃料極３に水素製造機１７で生成した水素を供給して発電した電力を電力負荷４に供給する。５は冷却熱回収熱交換器で、冷却回路６の冷却ポンプ７で冷却水を循環して燃料電池１の冷却部８から熱を得て貯湯循環回路９に放熱する。１８は水素製造機１７から排出する排気ガスから熱を得て貯湯循環回路９に放熱する排ガス熱回収熱交換器で、貯湯循環回路９に設けた循環ポンプ１１で貯湯槽１０の上部に高温にした温水を蓄える。１９は貯湯槽１０の上部入り口部と循環ポンプ１１の吸入側を接続して貯湯槽１０をバイパスする貯湯バイパス回路で、貯湯槽１０の上部入り口部に設けた開閉弁２０aと貯湯バイパス回路１９に設けた開閉弁２０ｂとを制御器１５で開閉制御して管路を切換る構成としている。
【００２２】
以上のように構成された燃料電池コージェネレーション装置について、以下その動作、作用を説明する。
【００２３】
まず、燃料電池１が発電するためには所定の温度以上に達している必要があるが、起動時には燃料電池１の温度は低く温度検出手段１６ａの検出値は低い値を検出している。制御装置１５で開閉弁２０aを閉じて開閉弁２０ｂを開放することにより、貯湯循環回路９の循環水を循環ポンプ１１によって冷却熱回収熱交換器５と排気ガス熱回収熱交換器１８に送り、貯湯槽１０をバイパスして貯湯バイパス回路１９に流して循環することができる。このとき燃料電池１は発電していないので冷却部８からは熱が発生しないが、水素製造装置１７は都市ガスなどの燃料を燃焼させて水素を製造し高温の排気ガスを排気ガス熱回収熱交換器におくるため、排気ガス熱回収熱交換器１８で得た熱で貯湯循環回路９の循環水を加熱して循環ポンプ１１によって冷却熱回収熱交換器９に運び、冷却ポンプ７で冷却回路６の冷却水を循環させて燃料電池１の冷却部８で放熱して燃料電池１を加熱することとなる。一方、貯湯槽１０の上部には循環水が入らないので、貯湯槽１０内の温度成層は保たれた状態を継続する。燃料電池１は加熱されて温度が充分高くなると、発電を開始して熱を発生し、温度検出手段１６ａの検出値も高い値を検出するので、制御器１５は開閉弁２０aを開放して開閉弁２０ｂを閉じるように制御する。このとき貯湯バイパス回路１９は閉塞された状態なので、貯湯槽１０の下部の水を循環ポンプ１１によって冷却熱回収熱交換器９と排気ガス熱回収熱交換器１８に送り、高温にして貯湯槽１０の上部に送り込み、貯湯槽１０の上部に高温水を蓄えることができる。
【００２４】
以上のように、本実施例においては、貯湯槽１０内の温度成層を崩すことなくシステム内で発生する水素製造装置１７の排気ガスの熱を利用して燃料電池を加熱して起動させることができる。
【００２５】
（実施例２）
図２は、本発明の第２の実施例の燃料電池コージェネレーション装置の構成図である。
【００２６】
図２において、２１は貯湯槽１０の下部出口に設けた逆止弁で、２２は貯湯循環回路９の貯湯バイパス回路１９の分岐部に設けた３方弁で、１５は燃料電池１の温度検出手段１６ａの検出値に応じて３方弁２２を切換制御する制御装置で、実施例１の構成と異なるところは、貯湯バイパス回路１９の回路切換手段として逆止弁２１と３方弁２２とを設けた点である。
【００２７】
以上のように構成された燃料電池コージェネレーション装置について、以下その動作、作用を説明する。
【００２８】
まず、起動時のように燃料電池１の温度が低い場合は、温度検出手段１６ａは低い値を検出し、制御装置１５は３方弁２２が貯湯バイパス回路１９に回路を接続するように制御するので、貯湯循環回路９を流れる低温の循環水は貯湯槽１０をバイパスして貯湯バイパス回路１９を流れる。このとき貯湯槽１０の下部出口に逆止弁２１を設けているので循環ポンプ１１が発停を繰り返しても貯湯槽１０に循環水が逆流するのを防止することができるので、温度成層を崩すことがない。
【００２９】
一方、燃料電池１の温度が充分高くなった場合は、温度検出手段１６ａは高い値を検出し、制御装置１５は３方弁２２が貯湯槽１０に流すように回路を接続して制御するので、貯湯循環回路９を流れる高温の循環水を貯湯槽１０の上部に蓄えることができる。
【００３０】
以上のように、本実施例においては、貯湯バイパス回路１９の回路切換手段として逆止弁２１と３方弁２２とを設けたことにより、簡単な構成で制御のための電力消費も少ない信頼性の高い回路切換手段を実現することができる。
【００３１】
（実施例３）
図３は、本発明の第３の実施例の燃料電池コージェネレーション装置の構成図である。
【００３２】
図３において、２３はガスまたは電気などを熱源とする補助熱源で、実施例１と２の構成と異なるところは、貯湯温度検知手段１６ｂを貯湯槽１０の上部入口に設けて、補助熱源２３を貯湯バイパス回路１９に設けた点である。
【００３３】
以上のように構成された燃料電池コージェネレーション装置について、以下その動作、作用を説明する。
【００３４】
まず、起動時は燃料電池１の温度検出手段１６ａの検出値は低い値を検出しているので、制御装置１５で開閉弁２０aを閉じて開閉弁２０ｂを開放することにより、貯湯循環回路９の循環水を循環ポンプ１１によって冷却熱回収熱交換器９と排気ガス熱回収熱交換器１８に送り、貯湯槽１０をバイパスして貯湯バイパス回路１９に流して循環することができる。
【００３５】
このとき排気ガス熱回収熱交換器１８で得た熱を冷却熱回収熱交換器９に送って燃料電池１の冷却部８で放熱して燃料電池１を加熱するが、さらに補助熱源２３を運転して循環水を加熱することにより燃料電池１の加熱量を増加することができる。
【００３６】
一方、燃料電池１が発電を開始して温度が上昇して温度検出手段１６ａの検出値が所定の値より高い値を検出した場合は、開閉弁２０aを開放して貯湯槽１０の上部に循環水を流すように制御器１５で制御する。燃料電池１の運転状態に応じて排気ガス熱回収熱交換器１８と冷却熱回収熱交換器９の加熱量は変わるが、貯湯温度検出手段１６ｂの値が所定の値になるように制御器１５で開閉弁２０aの開度を調節して貯湯バイパス回路１９を流れる流量を制御するとともに補助熱源２３の加熱量を制御する。
【００３７】
以上のように、本実施例においては、貯湯槽１０の上部入口に貯湯温度検知手段１６ｂを設け、貯湯バイパス回路１９に補助熱源２３を設けて制御器１５で制御することにより、燃料電池１の起動時には、補助熱源２３で燃料電池１を加熱することができるので起動時間を大幅に短縮することができる。さらに、貯湯循環回路９を流す循環水の一部を貯湯バイパス回路１９に流して補助熱源２３で加熱することにより燃料電池１の運転状態にかかわらず貯湯槽１０の上部に安定して高温の温水を蓄えることができる。
【００３８】
（実施例４）
図４は、本発明の第４の実施例の燃料電池コージェネレーション装置の構成図である。
【００３９】
図４において、２４は第２貯湯槽で、実施例３の構成と異なるところは、第２貯湯槽２４を貯湯バイパス回路１９の補助熱源２３の出口に設けた点と第２貯湯槽の入口に温度検出手段１６ｃを設けた点である。
【００４０】
以上のように構成された燃料電池コージェネレーション装置について、以下その動作、作用を説明する。
【００４１】
まず、燃料電池１が発電状態のときは、燃料電池１の温度検出手段１６ａの検出値は高い値を検出しているので、制御装置１５で開閉弁２０aを開放して開閉弁２０ｂを閉じて運転することにより、冷却熱回収熱交換器９と排気ガス熱回収熱交換器１８で加熱された温水を貯湯槽１０の上部に蓄えることができる。このとき、制御器１５で開閉弁２０ｂを開放し、温度検出手段１６ｃの検出値に応じて補助熱源２３で温水を加熱して第２貯湯槽２４に蓄えることにより、燃料電池１の再起動時には開閉弁２０ｂを開放して循環ポンプ１１で第２貯湯槽２４内の高温水を冷却熱回収熱交換器９に送って燃料電池１を加熱することができる。
【００４２】
以上のように、本実施例においては、第２貯湯槽２４を貯湯バイパス回路１９の補助熱源２３の出口に設けたことにより、小能力の小型の補助熱源で燃料電池１の起動時間を大幅に短縮することができ、給湯などの熱負荷に対しても迅速に対応ができる。
【００４３】
（実施例５）
図５は、本発明の第５の実施例の燃料電池コージェネレーション装置の構成図である。
【００４４】
図５において、２５は給湯配管で、実施例４の構成と異なるところは、貯湯バイパス回路１９の補助熱源２３の出口から分岐して給湯配管２５を設けた点である。
【００４５】
以上のように構成された燃料電池コージェネレーション装置について、以下その動作、作用を説明する。
【００４６】
まず、燃料電池１の定常運転時は、制御装置１５が開閉弁２０ａを開放して開閉弁２０ｂを閉じて運転して貯湯循環回路９の循環水を循環ポンプ１１で貯湯槽１０の上部に送る。給湯負荷が発生して時は、給湯開閉弁２０ｃが開放されると冷却熱回収熱交換器９と排気ガス熱回収熱交換器１８で加熱した循環水は貯湯バイパス回路１９を通って給湯配管２５から給湯水として供給し、循環回路の循環水量が少ない場合は貯湯槽１０の上部の温水を市水の圧力で押し出して貯湯バイパス回路１９で合流させて給湯配管２５から必要な給湯水量を供給する。
【００４７】
以上のように、本実施例においては、貯湯バイパス回路１９の補助熱源２３の出口で開閉弁２０ｂの手前から分岐して給湯配管２５を設けることにより、燃料電池１で発生する熱を蓄熱することなく直接給湯に利用することができ、給湯量が不足する場合は貯湯槽１０から自動的に温水を補うことができるので、簡単な配管構成で効率の良い給湯運転ができる。
【００４８】
（実施例６）
図６は、本発明の第６の実施例の燃料電池コージェネレーション装置の構成図である。
【００４９】
図６において、２６は暖房および乾燥用の放熱器２７に接続する熱利用熱交換器で、実施例１から５の構成と異なるところは、貯湯バイパス回路１９の補助熱源２３の下流に熱利用熱交換器２６を設けた点である。
【００５０】
以上のように構成された燃料電池コージェネレーション装置について、以下その動作、作用を説明する。
【００５１】
まず、燃料電池１の定常運転時は、制御装置１５が開閉弁２０ａを開放して開閉弁２０ｂを閉じて運転するので貯湯循環回路９の循環水を循環ポンプ１１で貯湯槽１０の上部に送る。暖房などの負荷が発生して放熱器２７を運転する場合は、制御器１５で開閉弁２０ｂを開放し、貯湯循環回路９の冷却熱回収熱交換器５と排気ガス熱回収熱交換器１８で加熱した循環水を貯湯バイパス回路１９に流して熱利用熱交換器２６で暖房に利用する。放熱器２７の負荷が大きい場合は補助熱源２３で不足分を加熱して負荷に対応する。一方、燃料電池１が停止しているときも同様に、開閉弁２０ｂを開放して循環ポンプ１１を運転し、貯湯バイパス回路１９に循環水を流して補助熱源２３で加熱して熱利用熱交換器２６に熱を与えて暖房する。
【００５２】
以上のように、本実施例においては貯湯バイパス回路１９の補助熱源２３の下流に熱利用熱交換器２６を設けることにより、燃料電池１で発生する熱を直接暖房などに利用することができ、負荷の大きい場合は補助熱源２３で加熱することにより、効率の良い安定した暖房運転が実現できる。
【００５３】
（実施例７）
図７は、本発明の第７の実施例の燃料電池コージェネレーション装置の構成図である。
【００５４】
図７において、２３は補助熱源で、２８は貯湯量検知手段で、実施例1から６の構成と異なるところは、貯湯量検知手段２８の検出値に応じて制御装置１５で制御する補助熱源２３を貯湯循環回路９の貯湯槽１０の入口に設けた点である。
【００５５】
以上のように構成された燃料電池コージェネレーション装置について、以下その動作、作用を説明する。
【００５６】
まず、燃料電池１の定常運転時は、貯湯槽１０の下部の低温水を循環ポンプ１１で冷却熱回収熱交換器５と排気ガス熱回収熱交換器１８に送って加熱し貯湯槽１０の上部に蓄えるが、電力負荷４が少なくて燃料電池１の発熱が少ない場合は、冷却熱回収熱交換器５と排気ガス熱回収熱交換器１８の加熱量も少なく循環水の温度も低くなるので、制御器１５で貯湯量検知手段２８の検出値が所定の値になるまで補助熱源２３で加熱して貯湯槽１０の上部に蓄える。
【００５７】
以上のように、本実施例においては、補助熱源２３を貯湯循環回路９の貯湯槽１０の入口に設けることにより、燃料電池１の運転状態に拘わらずに一定の給湯負荷に対応する温水量を貯湯槽１０に蓄えることができる。さらに、貯湯槽１０にためる温水の温度を高くすることにより貯湯槽１０を小型にすることができる。
【００５８】
（実施例８）
図８は、本発明の第８の実施例の燃料電池コージェネレーション装置の構成図である。
【００５９】
図８において、２６は暖房および乾燥用の放熱器２７に接続する熱利用熱交換器で、実施例７の構成と異なるところは、貯湯循環回路９の補助熱源２３の下流で貯湯槽１０の入口に設けた温度検出器１６ｂの上流に熱利用熱交換器２６を設けた点である。
【００６０】
以上のように構成された燃料電池コージェネレーション装置について、以下その動作、作用を説明する。
【００６１】
まず、暖房などの負荷が発生して放熱器２７を運転する場合は、制御器１５で開閉弁２０ａを開放して、貯湯循環回路９の循環ポンプ１１を運転して循環水を循環するが、燃料電池１が運転しているときは、冷却熱回収熱交換器５と排気ガス熱回収熱交換器１８で加熱した循環水を熱利用熱交換器２７に流して暖房運転ができる。一方、燃料電池１の電力負荷４の値が小さいか運転を停止しているときは補助熱源２３を運転して不足分を加熱するがこのとき貯湯槽１０の入口に設けた温度検出手段１６ｂの検出値が所定の値になるように制御器１５で補助熱源１５の加熱量を制御する。
【００６２】
以上のように、本実施例においては、貯湯循環回路９の補助熱源２３の下流で貯湯槽１０の入口に設けた温度検出手段１６ｂの上流に熱利用熱交換器２６を設けたことにより、燃料電池１で発生する熱を直接暖房などの熱として利用することができ、燃料電池１で発生する熱が不足する場合は自動的に補助熱源２３で補うことができる。さらに貯湯槽１０の上部に入る温水を任意の温度に設定することができるので、貯湯槽１０の温度成層を崩すこともなく安定して給湯負荷に対応できる。
【００６３】
（実施例９）
図９は、本発明の第９の実施例の燃料電池コージェネレーション装置の構成図である。
【００６４】
図９において、２９は４方弁で、実施例１の構成と異なるところは、一方を貯湯槽１０の下部出口と循環ポンプ１１の吸入側と接続し他方を循環ポンプ１１の吐出側と貯湯槽１０の上部入口を接続し、切換時には、一方を貯湯槽１０の下部出口と貯湯槽１０の上部入口を接続し他方を循環ポンプ１１の吸入側と循環ポンプ１１の吐出側とを接続する４方弁２９を貯湯循環回路９の回路切換手段として設けた点である。
【００６５】
以上のように構成された燃料電池コージェネレーション装置について、以下その動作、作用を説明する。
【００６６】
まず、定常運転時のように燃料電池１の温度が高い場合は、温度検出手段１６ａは高い値を検出し、制御装置１５は４方弁２９を、一方を貯湯槽１０の下部出口と循環ポンプ１１の吸入側と接続し他方を循環ポンプ１１の吐出側と貯湯槽１０の上部入口を接続するように制御して高温の温水を貯湯槽１０の上部に蓄える。起動時のように燃料電池１の温度が低い場合は、温度検出手段１６ａは低い値を検出し、制御装置１５は４方弁２９を一方を貯湯槽１０の下部出口と貯湯槽１０の上部入口を接続し他方を循環ポンプ１１の吐出側と循環ポンプ１１の吸入側とを接続するように制御して排気ガス熱回収熱交換器１８で得た熱を冷却熱回収熱交換器５に送って燃料電池１を加熱して起動させることができる。
【００６７】
以上のように、本実施例においては、４方弁２９を回路切換手段として用いることにより、簡単な構成でシステム内で発生する熱を排気ガス熱回収熱交換器１８で回収して燃料電池１を加熱して起動することができる。
【００６８】
（実施例１０）
図１０は、本発明の第１０の実施例の燃料電池コージェネレーション装置の構成図である。
【００６９】
図１０において、２９は４方弁で、実施例９の構成と異なるところは、一方を貯湯槽１０の下部出口と循環ポンプ１１の吸入側と接続し他方を循環ポンプ１１の吐出側と貯湯槽１０の上部入口を接続し、切換時には、一方を貯湯槽１０の下部出口と循環ポンプ１１の吐出側を接続し他方を貯湯槽１０の上部入口と循環ポンプ１１の吸入側とを接続する４方弁２９を貯湯循環回路９の回路切換手段として設けた点である。
【００７０】
以上のように構成された燃料電池コージェネレーション装置について、以下その動作、作用を説明する。
【００７１】
まず、定常運転時のように燃料電池１の温度が高い場合は、温度検出手段１６ａは高い値を検出し、制御装置１５は４方弁２９を、一方を貯湯槽１０の下部出口と循環ポンプ１１の吸入側と接続し他方を循環ポンプ１１の吐出側と貯湯槽１０の上部入口を接続するように制御して高温の温水を貯湯槽１０の上部に蓄える。起動時のように燃料電池１の温度が低い場合は、温度検出手段１６ａは低い値を検出し、制御装置１５は４方弁２９の一方を貯湯槽１０の下部出口と循環ポンプ１１の吐出側を接続し他方を貯湯槽１０の上部入口と循環ポンプ１１の吸入側とを接続するように制御して貯湯槽１０の上部に蓄えた高温の温水を４方弁２９を介して循環ポンプ１１で冷却熱回収熱交換器５に送って燃料電池１を加熱して起動させることができる。
【００７２】
以上のように、本実施例においては、４方弁２９を貯湯循環回路９の回路切換手段として用いることにより、簡単な構成で貯湯槽１０に蓄えた温水で燃料電池１を起動させることができる。
【００７３】
【発明の効果】
以上のように、本発明によれば、簡単な構成でシステム内部で発生する熱を回収して燃料電池を短時間で起動し、貯湯槽に温度成層を形成して温水を蓄ることができる高効率な燃料電池コージェネレーション装置を実現することができる。
【図面の簡単な説明】
【図１】本発明の実施例１における燃料電池コージェネレーション装置の構成図
【図２】本発明の実施例２における燃料電池コージェネレーション装置の構成図
【図３】本発明の実施例３における燃料電池コージェネレーション装置の構成図
【図４】本発明の実施例４における燃料電池コージェネレーション装置の構成図
【図５】本発明の実施例５における燃料電池コージェネレーション装置の構成図
【図６】本発明の実施例６における燃料電池コージェネレーション装置の構成図
【図７】本発明の実施例７における燃料電池コージェネレーション装置の構成図
【図８】本発明の実施例８における燃料電池コージェネレーション装置の構成図
【図９】本発明の実施例９における燃料電池コージェネレーション装置の構成図
【図１０】本発明の実施例１０における燃料電池コージェネレーション装置の構成図
【図１１】従来の燃料電池コージェネレーション装置の構成図
【符号の説明】
１燃料電池
５冷却熱回収熱交換器
６冷却回路
９貯湯循環回路
１０貯湯槽
１１循環ポンプ
１５制御器（制御装置）
１６ａ温度検出手段
１６ｂ温度検出手段
１６ｃ温度検出手段
１７水素製造装置
１８排気ガス熱回収熱交換器
１９貯湯バイパス回路
２０ａ開閉弁（回路切換手段）
２０ｂ開閉弁（回路切換手段）
２１逆止弁
２２３方弁（３方切換手段）
２３補助熱源
２４第２貯湯槽
２５給湯配管
２６熱利用熱交換器
２７放熱器
２８貯湯量検出手段
２９４方弁（４方切換手段）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel cell cogeneration apparatus that recovers heat generated during power generation of a fuel cell and uses it for hot water supply and heating.
[0002]
[Prior art]
Conventionally, as this type of fuel cell cogeneration apparatus, there is one as shown in FIG.
[0003]
FIG. 11 is a configuration diagram of a conventional fuel cell cogeneration apparatus. Reference numeral 1 denotes a fuel cell. Electric power is generated by supplying electric power generated by supplying air to the oxygen electrode 2 and fuel gas such as hydrogen gas to the fuel electrode 3. To supply. A cooling heat recovery heat exchanger 5 circulates cooling water by the cooling pump 7 of the cooling circuit 6, obtains heat from the cooling unit 8 of the fuel cell 1, and dissipates heat to the hot water storage circulation circuit 9. Reference numeral 10 denotes a hot water tank. The low-temperature water at the lower part of the hot water tank 10 is sent to the cooling heat recovery heat exchanger 5 by the circulation pump 11 and heated to store hot water at a high temperature in the upper part of the hot water tank 10. A heat exchanger 12 is provided in the cooling bypass circuit 14 branched by the three-way switching means 13 provided in the cooling circuit 6 and dissipates heat generated by the fuel cell 1. Reference numeral 15 denotes a controller, which controls the amount of circulation of the circulation pump 11 according to the temperature detected by the temperature detection means 16 provided on the return side of the heat storage tank 10 of the hot water storage circuit 9 and the temperature of the hot water entering the upper part of the heat storage tank 10. Is controlled to a predetermined temperature (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
JP 2000-340244 A
[0005]
[Problems to be solved by the invention]
However, in the conventional configuration, in order to start the fuel cell, it is necessary to heat from the outside, which has problems such as low energy efficiency and long start-up time.
[0006]
The present invention solves the above-described conventional problems, and a hot water storage bypass circuit is provided in the hot water circulation circuit to heat and start the fuel cell with heat generated in the system without destroying the temperature stratification of the hot water tank when starting the fuel cell. The goal is to increase energy efficiency and reduce startup time.
[0007]
[Means for Solving the Problems]
In order to solve the conventional problem, a fuel cell cogeneration apparatus according to the present invention includes: A hot water storage circulation circuit comprising a hot water storage tank, a circulation pump, a cooling heat recovery heat exchanger provided in the cooling circuit of the fuel cell, and an exhaust gas heat recovery heat exchanger for recovering the exhaust heat of the hydrogen production device in order by piping connection; A hot water storage bypass circuit for bypassing the hot water storage tank in the hot water storage circulation circuit, a circuit switching means for switching the hot water storage bypass circuit, a temperature detection means for the fuel cell, and a signal of the temperature detection means according to the signal of the temperature detection means. When the temperature does not reach the predetermined temperature, the hot water tank is bypassed in the hot water circulation circuit, and the circulating water flows into the hot water bypass circuit, and when the temperature of the fuel cell exceeds the predetermined temperature, the circulating water is supplied to the hot water tank. Said to flow And a control device for switching the circuit switching means.
[0008]
This allows hot water in the hot water circulation circuit to flow through the hot water bypass circuit without passing through the hot water tank when the fuel cell is started, so that exhaust gas can be discharged without putting low temperature water into the upper part of the hot water tank and destroying the temperature stratification. The heat generated in the system can be recovered by the system heat recovery heat exchanger and the fuel cell can be heated via the cooling heat recovery heat exchanger.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The invention described in claim 1 is a heat recovery heat exchanger provided in a hot water tank, a circulation pump, and a fuel cell cooling circuit, and exhaust heat of a hydrogen production apparatus. The A hot-water storage circulation circuit configured by pipe-connecting exhaust gas heat recovery heat exchanger to be recovered in order, Said A hot water storage bypass circuit for bypassing the hot water tank in the hot water circulation circuit, Said Circuit switching means for switching the hot water storage bypass circuit, temperature detection means for the fuel cell, Said Depending on the temperature detection means signal When the temperature of the fuel cell does not reach a predetermined temperature, the hot water storage tank is bypassed in the hot water storage circulation circuit, and the circulating water flows into the hot water storage bypass circuit, and when the temperature of the fuel cell exceeds a predetermined temperature, the hot water storage The circulating water flows through the tank By providing a control device for switching the circuit switching means, when the temperature detection means of the fuel cell does not reach a predetermined value, the circuit switching means is switched to the hot water storage bypass circuit by the controller. By circulating the hot water in the hot water circulation circuit without passing through the tank, it is possible to prevent the low temperature water from entering the upper part of the hot water tank and prevent the temperature stratification from collapsing, and the system heat recovery heat exchanger The obtained heat can be heated through the cooling heat recovery heat exchanger to raise the temperature of the fuel cell, so that the startup time of the fuel cell can be shortened.
[0010]
The invention described in claim 2 particularly relates to the fuel cell cogeneration apparatus according to claim 1. Circuit switching means in A check valve provided at the outlet of the hot water tank, and a three-way switching means provided at the bypass branch of the hot water circulation circuit so By configuring, it is possible to reduce the control power for switching the circuit and switch the circuit reliably, so that a highly efficient and reliable fuel cell cogeneration apparatus can be realized.
[0011]
The invention according to claim 3 is particularly the fuel cell cogeneration apparatus according to claim 1 or 2. In addition to, Auxiliary heat source provided in the hot water storage bypass circuit, hot water storage temperature detection means provided at the hot water tank inlet of the hot water circulation circuit, The control means heats the circulating water flowing through the hot water storage bypass circuit by the auxiliary heat source until the temperature of the fuel cell reaches a predetermined temperature, and the temperature of the fuel cell becomes equal to or higher than the predetermined temperature. After circulating water flows through the hot water storage tank by the switching means, the circuit switching means flows through the hot water bypass circuit so that the temperature of the hot water tank inlet becomes a predetermined temperature in accordance with a signal from the hot water temperature detection means. Control the flow rate and heating amount of the auxiliary heat source With this configuration, when the specified hot water is not stored in the hot water storage tank, it is heated by the auxiliary heat source provided in the hot water storage bypass circuit and stored in the hot water storage tank to supply hot water. Since the circulating water heated by the heat source can be passed through the cooling heat recovery heat exchanger to heat the fuel cell, stable hot water can be supplied by the auxiliary heat source and the start-up time of the fuel cell can be greatly shortened. it can.
[0012]
The invention according to claim 4 is particularly the fuel cell cogeneration apparatus according to claim 3. In addition to, Second hot water tank installed at the outlet of the auxiliary heat source of the hot water storage bypass circuit Have By adopting the configuration, warm water having a temperature higher than the operating temperature of the fuel cell can be stored in the second hot water tank, so that a large amount of heat is taken out from the second hot water tank when the fuel cell is started, and a cooling heat recovery heat exchanger Since the fuel cell can be heated via the fuel cell, the start-up time of the fuel cell can be greatly shortened. Furthermore, since hot hot water can always be stored in the second hot water tank, hot water can be stably supplied even when the hot water in the hot water tank is insufficient.
[0013]
The invention according to claim 5 is particularly the fuel cell cogeneration apparatus according to claim 4. In addition to, By providing a hot water supply pipe branched from the auxiliary heat source outlet of the hot water storage bypass circuit, hot water can be heated to an arbitrary temperature and supplied with the auxiliary heat source.
[0014]
The invention according to claim 6 is the fuel cell cogeneration apparatus according to any one of claims 1 to 5. In addition to, By adopting a configuration in which a heat-utilizing heat exchanger having heating and drying radiators is provided downstream of the auxiliary heat source of the hot water storage bypass circuit, the heat generated in the fuel cell can be used for heating and drying. . Further, when the heat generated by the fuel cell is insufficient, it can be supplemented by an auxiliary heat source, so that an economical and stable heating operation can be performed.
[0015]
The invention described in claim 7 is, in particular, claimed in claim 1 Fuel cell cogeneration system as described in In addition to, An auxiliary heat source provided at the hot water tank inlet of the hot water circulation circuit, and a hot water storage amount detecting means provided in the hot water tank; And the control means heats the circulating water circulating through the hot water circulation circuit with an auxiliary heat source until the hot water quantity detecting means detects that a predetermined amount of hot water has been stored in the hot water storage tank. The fuel cell is operated by controlling the hot water circulating in the hot water circulation circuit with the auxiliary heat source until the hot water amount detecting means provided in the hot water tank detects a predetermined value. Regardless of the state, a constant amount of hot water can be stored in the hot water storage tank, so that stable hot water supply operation without running out of hot water can be performed.
[0016]
The invention according to claim 8 is the fuel cell cogeneration apparatus according to claim 7 in particular. In addition to the temperature detection means provided at the hot water tank inlet of the hot water circulation circuit, Downstream of auxiliary heat source in hot water circulation circuit Upstream of the temperature detection means provided at the hot water tank inlet A heat-use heat exchanger having a radiator for heating and drying provided in And the control means Detection value of temperature detection means So that the value becomes a predetermined value. Heat source Heating amount Heating and drying radiators that dissipate the heat obtained in the cooling heat recovery heat exchanger and exhaust gas heat recovery heat exchanger provided in the hot water circulation circuit with a heat-use heat exchanger. Can be used. In addition, when the fuel cell is stopped or the outlet temperature of the heat-utilizing heat exchanger becomes lower than a predetermined value, the auxiliary heat source is controlled by the control device so that the detected value of the hot water storage temperature detecting means becomes a predetermined value. By doing so, it is possible to stably cope with heating and drying operation, and it is possible to keep the temperature in the hot water tank at a predetermined value.
[0017]
The invention according to claim 9 includes a hot water storage tank, a circulation pump, a cooling heat recovery heat exchanger provided in the fuel cell cooling circuit, and an exhaust gas heat recovery heat exchanger for recovering exhaust heat of the hydrogen production device in order. Connected to the hot water circulation circuit constructed by piping, one connected to the lower outlet of the hot water tank and the suction side of the circulation pump, the other connected to the discharge side of the circulation pump and the upper inlet of the hot water tank, and when switching, one of the hot water storage circuits Four-way switching means for connecting the lower outlet of the tank and the upper inlet of the hot water tank and connecting the other to the discharge side of the circulation pump and the suction side of the circulation pump; and temperature detection means for the fuel cell; Said Depending on the detection value of the temperature detection means When the temperature of the fuel cell does not reach a predetermined temperature, one is connected to the lower outlet of the hot water tank and the upper inlet of the hot water tank, and the other is connected to the circulation pump suction side and the discharge side of the circulation pump When the temperature of the fuel cell exceeds a predetermined temperature, one is connected to the lower outlet of the hot water tank and the suction side of the circulation pump, and the other is connected to the discharge side of the circulation pump and the upper inlet of the hot water tank. To the above And a control device for switching and controlling the four-way switching means. When the detected value of the temperature detecting means of the fuel cell is lower than a predetermined value, the four-way switching means uses the circulation pump discharge side and the circulation pump. So that low-temperature water does not enter the upper inlet of the hot water tank, and the heat obtained by the system heat recovery heat exchanger is dissipated to the fuel cell via the cooling heat exchanger. By controlling with the controller, the fuel cell can be heated at the start-up without losing the temperature stratification of the hot water tank with a simple structure.
[0018]
The invention according to claim 10 is: A hot water storage circuit comprising a hot water storage tank, a circulation pump, a cooling heat recovery heat exchanger provided in a cooling circuit of the fuel cell, and an exhaust gas heat recovery heat exchanger for recovering exhaust heat of the hydrogen production device in order. When, One is connected to the lower outlet of the hot water tank and the suction side of the circulation pump, and the other is connected to the discharge side of the circulation pump and the upper inlet of the hot water tank. When switching, one is connected to the lower outlet of the hot water tank and the discharge side of the circulation pump A four-way switching means for connecting the upper inlet of the hot water tank and the suction side of the circulation pump, a temperature detecting means for the fuel cell, Said Depending on the detection value of the temperature detection means When the temperature of the fuel cell does not reach a predetermined temperature, one is connected to the lower outlet of the hot water tank and the discharge side of the circulation pump, and the other is connected to the upper inlet of the hot water tank and the suction side of the circulation pump When the temperature of the fuel cell exceeds a predetermined temperature, one is connected to the lower outlet of the hot water tank and the suction side of the circulation pump, and the other is connected to the discharge side of the circulation pump and the upper inlet of the hot water tank. To the above And a control device for switching control of the four-way switching means, and when the detected value of the temperature detection means of the fuel cell is lower than a predetermined value, one of the four-way switching means is connected to the lower outlet of the hot water tank. Connected to the discharge side of the circulation pump and the other side to the upper inlet of the hot water tank and the suction side of the circulation pump, and the hot water at the upper part of the hot water tank is placed in the cooling heat exchanger to control the fuel cell. By controlling with a vessel, the fuel cell can be heated with a simple structure using the heat of the hot water tank.
[0019]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0020]
Example 1
FIG. 1 shows a configuration diagram of a fuel cell cogeneration apparatus according to a first embodiment of the present embodiment.
[0021]
In FIG. 1, reference numeral 1 denotes a fuel cell using a solid polymer membrane, which supplies air to the oxygen electrode 2 and hydrogen generated by the hydrogen production machine 17 to the fuel electrode 3 to supply electric power to the electric power load 4. A cooling heat recovery heat exchanger 5 circulates cooling water by the cooling pump 7 of the cooling circuit 6, obtains heat from the cooling unit 8 of the fuel cell 1, and dissipates heat to the hot water storage circulation circuit 9. An exhaust gas heat recovery heat exchanger 18 obtains heat from the exhaust gas discharged from the hydrogen production machine 17 and dissipates heat to the hot water circulation circuit 9. The circulation pump 11 provided in the hot water circulation circuit 9 raises the temperature of the hot water tank 10 to a high temperature. Store warm water. A hot water storage bypass circuit 19 bypasses the hot water tank 10 by connecting the upper inlet portion of the hot water tank 10 and the suction side of the circulation pump 11, and is connected to the on-off valve 20 a and the hot water storage bypass circuit 19 provided at the upper inlet portion of the hot water tank 10. The provided on-off valve 20b is controlled to be opened and closed by the controller 15 to switch the pipeline.
[0022]
The operation and action of the fuel cell cogeneration apparatus configured as described above will be described below.
[0023]
First, in order for the fuel cell 1 to generate electric power, it is necessary to reach a predetermined temperature or more, but at the time of startup, the temperature of the fuel cell 1 is low and the detection value of the temperature detecting means 16a is detected to be low. By closing the on-off valve 20a and opening the on-off valve 20b with the control device 15, the circulating water of the hot water storage circuit 9 is sent to the cooling heat recovery heat exchanger 5 and the exhaust gas heat recovery heat exchanger 18 by the circulation pump 11, The hot water storage tank 10 can be bypassed and flowed to the hot water storage bypass circuit 19 for circulation. At this time, since the fuel cell 1 is not generating power, heat is not generated from the cooling unit 8, but the hydrogen production device 17 combusts fuel such as city gas to produce hydrogen, and heat exhaust gas heat recovery heat from the high-temperature exhaust gas. In order to put it in the exchanger, the circulating water in the hot water storage circuit 9 is heated by the heat obtained in the exhaust gas heat recovery heat exchanger 18 and is carried to the cooling heat recovery heat exchanger 9 by the circulation pump 11, and the cooling circuit by the cooling pump 7. The cooling water 6 is circulated and radiated by the cooling unit 8 of the fuel cell 1 to heat the fuel cell 1. On the other hand, since circulating water does not enter the upper part of the hot water tank 10, the temperature stratification in the hot water tank 10 is maintained. When the fuel cell 1 is heated to a sufficiently high temperature, power generation is started to generate heat, and the detected value of the temperature detecting means 16a is also detected as a high value, so the controller 15 opens and closes the on-off valve 20a. The valve 20b is controlled to be closed. At this time, since the hot water storage bypass circuit 19 is closed, the water in the lower part of the hot water storage tank 10 is sent to the cooling heat recovery heat exchanger 9 and the exhaust gas heat recovery heat exchanger 18 by the circulation pump 11 and is heated to a high temperature. The hot water can be stored in the upper part of the hot water tank 10.
[0024]
As described above, in this embodiment, the fuel cell is heated and started up using the heat of the exhaust gas of the hydrogen production device 17 generated in the system without destroying the temperature stratification in the hot water tank 10. it can.
[0025]
(Example 2)
FIG. 2 is a configuration diagram of a fuel cell cogeneration apparatus according to a second embodiment of the present invention.
[0026]
In FIG. 2, 21 is a check valve provided at the lower outlet of the hot water tank 10, 22 is a three-way valve provided at a branch portion of the hot water storage bypass circuit 19 of the hot water circulation circuit 9, and 15 is a temperature detection of the fuel cell 1. The control device for switching and controlling the three-way valve 22 according to the detection value of the means 16a differs from the configuration of the first embodiment in that a check valve 21 and a three-way valve 22 are used as circuit switching means for the hot water storage bypass circuit 19. It is a point provided.
[0027]
The operation and action of the fuel cell cogeneration apparatus configured as described above will be described below.
[0028]
First, when the temperature of the fuel cell 1 is low as at the time of startup, the temperature detecting means 16a detects a low value, and the control device 15 controls the three-way valve 22 to connect the circuit to the hot water storage bypass circuit 19. Therefore, the low-temperature circulating water flowing through the hot water storage circuit 9 bypasses the hot water tank 10 and flows through the hot water storage bypass circuit 19. At this time, since the check valve 21 is provided at the lower outlet of the hot water tank 10, the circulating water can be prevented from flowing back into the hot water tank 10 even if the circulation pump 11 repeatedly starts and stops, so that the temperature stratification is destroyed. There is nothing.
[0029]
On the other hand, when the temperature of the fuel cell 1 becomes sufficiently high, the temperature detection means 16a detects a high value, and the control device 15 controls the three-way valve 22 to flow into the hot water tank 10 by connecting a circuit. The hot circulating water flowing through the hot water storage circuit 9 can be stored in the upper part of the hot water tank 10.
[0030]
As described above, in the present embodiment, the check valve 21 and the three-way valve 22 are provided as the circuit switching means of the hot water storage bypass circuit 19, so that the power consumption for control is reduced with a simple configuration. High circuit switching means can be realized.
[0031]
(Example 3)
FIG. 3 is a configuration diagram of a fuel cell cogeneration apparatus according to a third embodiment of the present invention.
[0032]
In FIG. 3, reference numeral 23 denotes an auxiliary heat source using gas or electricity as a heat source. The difference from the configurations of the first and second embodiments is that a hot water storage temperature detection means 16b is provided at the upper inlet of the hot water tank 10 and the auxiliary heat source 23 is provided. This is a point provided in the hot water storage bypass circuit 19.
[0033]
The operation and action of the fuel cell cogeneration apparatus configured as described above will be described below.
[0034]
First, since the detected value of the temperature detecting means 16a of the fuel cell 1 is low at the time of startup, the control device 15 closes the on-off valve 20a and opens the on-off valve 20b, so that the hot water storage circuit 9 Circulating water can be sent to the cooling heat recovery heat exchanger 9 and the exhaust gas heat recovery heat exchanger 18 by the circulation pump 11, bypassing the hot water tank 10 and flowing to the hot water bypass circuit 19 for circulation.
[0035]
At this time, the heat obtained by the exhaust gas heat recovery heat exchanger 18 is sent to the cooling heat recovery heat exchanger 9 to dissipate heat in the cooling unit 8 of the fuel cell 1 to heat the fuel cell 1, but the auxiliary heat source 23 is further operated. Then, the heating amount of the fuel cell 1 can be increased by heating the circulating water.
[0036]
On the other hand, when the fuel cell 1 starts power generation and the temperature rises and the detected value of the temperature detecting means 16a detects a value higher than a predetermined value, the on-off valve 20a is opened to circulate in the upper part of the hot water tank 10. Control is performed by the controller 15 so that water flows. Although the heating amounts of the exhaust gas heat recovery heat exchanger 18 and the cooling heat recovery heat exchanger 9 change according to the operating state of the fuel cell 1, the controller 15 adjusts the value of the hot water storage temperature detection means 16b to a predetermined value. Then, the opening degree of the on-off valve 20a is adjusted to control the flow rate through the hot water storage bypass circuit 19 and the heating amount of the auxiliary heat source 23.
[0037]
As described above, in this embodiment, the hot water storage temperature detection means 16b is provided at the upper inlet of the hot water tank 10, the auxiliary heat source 23 is provided in the hot water storage bypass circuit 19, and the controller 15 controls the fuel cell 1. At the time of start-up, since the fuel cell 1 can be heated by the auxiliary heat source 23, the start-up time can be greatly shortened. Further, a part of the circulating water flowing through the hot water storage circulation circuit 9 flows into the hot water storage bypass circuit 19 and is heated by the auxiliary heat source 23, so that the hot water is stably heated at the upper part of the hot water tank 10 regardless of the operation state of the fuel cell 1. Can be stored.
[0038]
Example 4
FIG. 4 is a configuration diagram of a fuel cell cogeneration apparatus according to a fourth embodiment of the present invention.
[0039]
In FIG. 4, reference numeral 24 denotes a second hot water tank, which differs from the configuration of the third embodiment in that the second hot water tank 24 is provided at the outlet of the auxiliary heat source 23 of the hot water bypass circuit 19 and at the inlet of the second hot water tank. The temperature detecting means 16c is provided.
[0040]
The operation and action of the fuel cell cogeneration apparatus configured as described above will be described below.
[0041]
First, when the fuel cell 1 is in the power generation state, the detected value of the temperature detection means 16a of the fuel cell 1 is detected as a high value, so the control device 15 opens the on-off valve 20a and closes the on-off valve 20b. By operating, hot water heated by the cooling heat recovery heat exchanger 9 and the exhaust gas heat recovery heat exchanger 18 can be stored in the upper part of the hot water tank 10. At this time, when the fuel cell 1 is restarted, the controller 15 opens the on-off valve 20b, heats the hot water by the auxiliary heat source 23 according to the detected value of the temperature detecting means 16c, and stores it in the second hot water tank 24. The fuel cell 1 can be heated by opening the on-off valve 20 b and sending the high-temperature water in the second hot water storage tank 24 to the cooling heat recovery heat exchanger 9 by the circulation pump 11.
[0042]
As described above, in this embodiment, the second hot water storage tank 24 is provided at the outlet of the auxiliary heat source 23 of the hot water storage bypass circuit 19, so that the start-up time of the fuel cell 1 is greatly reduced with a small capacity small auxiliary heat source. It can be shortened and can respond quickly to heat loads such as hot water supply.
[0043]
(Example 5)
FIG. 5 is a block diagram of a fuel cell cogeneration apparatus according to a fifth embodiment of the present invention.
[0044]
In FIG. 5, reference numeral 25 denotes a hot water supply pipe, which is different from the configuration of the fourth embodiment in that a hot water supply pipe 25 is branched from the outlet of the auxiliary heat source 23 of the hot water storage bypass circuit 19.
[0045]
The operation and action of the fuel cell cogeneration apparatus configured as described above will be described below.
[0046]
First, during steady operation of the fuel cell 1, the control device 15 opens and opens the on-off valve 20 a and closes the on-off valve 20 b to send the circulating water of the hot water storage circuit 9 to the upper part of the hot water tank 10 by the circulation pump 11. . When a hot water supply load is generated, when the hot water on / off valve 20c is opened, the circulating water heated by the cooling heat recovery heat exchanger 9 and the exhaust gas heat recovery heat exchanger 18 passes through the hot water storage bypass circuit 19 and the hot water supply pipe 25. When the amount of circulating water in the circulation circuit is small, the hot water in the upper part of the hot water storage tank 10 is pushed out by the pressure of the city water and merged in the hot water storage bypass circuit 19 to supply the necessary amount of hot water from the hot water supply pipe 25. .
[0047]
As described above, in the present embodiment, the heat generated in the fuel cell 1 is stored by branching from the front of the on-off valve 20b at the outlet of the auxiliary heat source 23 of the hot water storage bypass circuit 19 to provide the hot water supply pipe 25. The hot water supply can be automatically supplemented from the hot water storage tank 10 when the amount of hot water supply is insufficient, so that an efficient hot water supply operation can be performed with a simple piping configuration.
[0048]
(Example 6)
FIG. 6 is a configuration diagram of a fuel cell cogeneration apparatus according to a sixth embodiment of the present invention.
[0049]
In FIG. 6, reference numeral 26 denotes a heat-use heat exchanger connected to a radiator 27 for heating and drying. The difference from the configurations of the first to fifth embodiments is that heat-use heat is provided downstream of the auxiliary heat source 23 of the hot water storage bypass circuit 19. This is the point where the exchanger 26 is provided.
[0050]
The operation and action of the fuel cell cogeneration apparatus configured as described above will be described below.
[0051]
First, during the steady operation of the fuel cell 1, the control device 15 operates by opening the on-off valve 20a and closing the on-off valve 20b, so that the circulating water in the hot water circulation circuit 9 is sent to the upper part of the hot water tank 10 by the circulation pump 11. . When a load such as heating is generated and the radiator 27 is operated, the controller 15 opens the on-off valve 20b, and the cooling heat recovery heat exchanger 5 and the exhaust gas heat recovery heat exchanger 18 of the hot water circulation circuit 9 are opened. The heated circulating water flows into the hot water storage bypass circuit 19 and is used for heating by the heat-use heat exchanger 26. When the load of the radiator 27 is large, the shortage is heated by the auxiliary heat source 23 to cope with the load. On the other hand, when the fuel cell 1 is stopped, similarly, the on-off valve 20b is opened to operate the circulation pump 11, and the circulating water is supplied to the hot water storage bypass circuit 19 and heated by the auxiliary heat source 23 to exchange heat using heat. Heat the unit 26 by heating it.
[0052]
As described above, in the present embodiment, by providing the heat utilization heat exchanger 26 downstream of the auxiliary heat source 23 of the hot water storage bypass circuit 19, the heat generated in the fuel cell 1 can be directly used for heating, etc. When the load is large, efficient and stable heating operation can be realized by heating with the auxiliary heat source 23.
[0053]
(Example 7)
FIG. 7 is a configuration diagram of a fuel cell cogeneration apparatus according to a seventh embodiment of the present invention.
[0054]
In FIG. 7, reference numeral 23 denotes an auxiliary heat source, reference numeral 28 denotes hot water storage amount detection means, and the difference from the configurations of the first to sixth embodiments is the auxiliary heat source 23 controlled by the control device 15 in accordance with the detection value of the hot water storage amount detection means 28. Is provided at the inlet of the hot water storage tank 10 of the hot water storage circuit 9.
[0055]
The operation and action of the fuel cell cogeneration apparatus configured as described above will be described below.
[0056]
First, during steady operation of the fuel cell 1, the low-temperature water at the bottom of the hot water tank 10 is sent to the cooling heat recovery heat exchanger 5 and the exhaust gas heat recovery heat exchanger 18 by the circulation pump 11 and heated to heat the upper part of the hot water tank 10. However, when the power load 4 is small and the fuel cell 1 generates little heat, the heating amount of the cooling heat recovery heat exchanger 5 and the exhaust gas heat recovery heat exchanger 18 is small and the temperature of the circulating water is also low. The controller 15 is heated by the auxiliary heat source 23 and stored in the upper part of the hot water tank 10 until the detection value of the hot water storage amount detection means 28 reaches a predetermined value.
[0057]
As described above, in the present embodiment, by providing the auxiliary heat source 23 at the inlet of the hot water storage tank 10 of the hot water storage circuit 9, the amount of hot water corresponding to a constant hot water supply load can be obtained regardless of the operating state of the fuel cell 1. It can be stored in the hot water tank 10. Furthermore, the hot water storage tank 10 can be reduced in size by increasing the temperature of the hot water accumulated in the hot water storage tank 10.
[0058]
(Example 8)
FIG. 8 is a configuration diagram of a fuel cell cogeneration apparatus according to an eighth embodiment of the present invention.
[0059]
In FIG. 8, reference numeral 26 denotes a heat-use heat exchanger connected to a radiator 27 for heating and drying. The difference from the configuration of the seventh embodiment is that the inlet of the hot water tank 10 is downstream of the auxiliary heat source 23 of the hot water circulation circuit 9. The heat utilization heat exchanger 26 is provided upstream of the temperature detector 16b provided in FIG.
[0060]
The operation and action of the fuel cell cogeneration apparatus configured as described above will be described below.
[0061]
First, when a load such as heating is generated and the radiator 27 is operated, the controller 15 opens the on-off valve 20a and operates the circulation pump 11 of the hot water circulation circuit 9 to circulate the circulating water. When the fuel cell 1 is in operation, the circulating water heated by the cooling heat recovery heat exchanger 5 and the exhaust gas heat recovery heat exchanger 18 is allowed to flow to the heat utilization heat exchanger 27 to perform heating operation. On the other hand, when the value of the power load 4 of the fuel cell 1 is small or the operation is stopped, the auxiliary heat source 23 is operated to heat the shortage, but at this time, the temperature detection means 16b provided at the inlet of the hot water tank 10 The controller 15 controls the heating amount of the auxiliary heat source 15 so that the detected value becomes a predetermined value.
[0062]
As described above, in this embodiment, the heat utilization heat exchanger 26 is provided downstream of the auxiliary heat source 23 of the hot water circulation circuit 9 and upstream of the temperature detection means 16b provided at the inlet of the hot water storage tank 10, thereby The heat generated in the battery 1 can be directly used as heat for heating or the like, and when the heat generated in the fuel cell 1 is insufficient, it can be automatically compensated by the auxiliary heat source 23. Furthermore, since the hot water entering the upper part of the hot water tank 10 can be set to an arbitrary temperature, the hot water tank 10 can stably cope with the hot water supply load without destroying the temperature stratification.
[0063]
Example 9
FIG. 9 is a configuration diagram of a fuel cell cogeneration apparatus according to a ninth embodiment of the present invention.
[0064]
In FIG. 9, reference numeral 29 denotes a four-way valve, which differs from the configuration of the first embodiment in that one is connected to the lower outlet of the hot water tank 10 and the suction side of the circulation pump 11 and the other is the discharge side of the circulation pump 11 and the hot water tank. 10 is connected to the upper inlet of the hot water tank 10 and one of the upper inlet of the hot water tank 10 is connected, and the other is connected to the suction side of the circulation pump 11 and the discharge side of the circulation pump 11. The valve 29 is provided as a circuit switching means of the hot water storage circuit 9.
[0065]
The operation and action of the fuel cell cogeneration apparatus configured as described above will be described below.
[0066]
First, when the temperature of the fuel cell 1 is high as in steady operation, the temperature detection means 16a detects a high value, and the control device 15 causes the four-way valve 29, one of which is the lower outlet of the hot water tank 10 and the circulation pump. 11 is connected to the suction side, and the other is connected to the discharge side of the circulation pump 11 and the upper inlet of the hot water tank 10 to store hot hot water in the upper part of the hot water tank 10. When the temperature of the fuel cell 1 is low as at the time of start-up, the temperature detecting means 16a detects a low value, and the control device 15 uses one of the four-way valve 29 as the lower outlet of the hot water tank 10 and the upper inlet of the hot water tank 10. And the other side is controlled so as to connect the discharge side of the circulation pump 11 and the suction side of the circulation pump 11, and the heat obtained by the exhaust gas heat recovery heat exchanger 18 is sent to the cooling heat recovery heat exchanger 5. The fuel cell 1 can be heated and started.
[0067]
As described above, in this embodiment, by using the four-way valve 29 as the circuit switching means, the heat generated in the system is recovered by the exhaust gas heat recovery heat exchanger 18 with a simple configuration, and the fuel cell 1 Can be started by heating.
[0068]
(Example 10)
FIG. 10 is a configuration diagram of a fuel cell cogeneration apparatus according to a tenth embodiment of the present invention.
[0069]
In FIG. 10, reference numeral 29 denotes a four-way valve, which differs from the configuration of the ninth embodiment in that one is connected to the lower outlet of the hot water tank 10 and the suction side of the circulation pump 11 and the other is the discharge side of the circulation pump 11 and the hot water tank. The upper inlet of the hot water tank 10 is connected to the lower outlet of the hot water tank 10 and the discharge side of the circulation pump 11, and the other is connected to the upper inlet of the hot water tank 10 and the suction side of the circulation pump 11 when switching. The valve 29 is provided as a circuit switching means of the hot water storage circuit 9.
[0070]
The operation and action of the fuel cell cogeneration apparatus configured as described above will be described below.
[0071]
First, when the temperature of the fuel cell 1 is high as in steady operation, the temperature detection means 16a detects a high value, and the control device 15 causes the four-way valve 29, one of which is the lower outlet of the hot water tank 10 and the circulation pump. 11 is connected to the suction side, and the other is connected to the discharge side of the circulation pump 11 and the upper inlet of the hot water tank 10 to store hot hot water in the upper part of the hot water tank 10. When the temperature of the fuel cell 1 is low as at the time of startup, the temperature detection means 16a detects a low value, and the control device 15 connects one of the four-way valves 29 to the lower outlet of the hot water tank 10 and the discharge side of the circulation pump 11 Is connected to the upper inlet of the hot water storage tank 10 and the suction side of the circulation pump 11, and hot water stored in the upper part of the hot water storage tank 10 is connected to the hot water tank 10 via the four-way valve 29. The fuel cell 1 can be heated and started by sending it to the cooling heat recovery heat exchanger 5.
[0072]
As described above, in this embodiment, by using the four-way valve 29 as the circuit switching means of the hot water storage circuit 9, the fuel cell 1 can be started up with hot water stored in the hot water tank 10 with a simple configuration. .
[0073]
【The invention's effect】
As described above, according to the present invention, it is possible to recover heat generated in the system with a simple configuration, start the fuel cell in a short time, form a temperature stratification in the hot water storage tank, and store hot water. A highly efficient fuel cell cogeneration system can be realized.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a fuel cell cogeneration apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a configuration diagram of a fuel cell cogeneration apparatus according to a second embodiment of the present invention.
FIG. 3 is a configuration diagram of a fuel cell cogeneration apparatus according to a third embodiment of the present invention.
FIG. 4 is a configuration diagram of a fuel cell cogeneration apparatus according to Embodiment 4 of the present invention.
FIG. 5 is a configuration diagram of a fuel cell cogeneration apparatus according to a fifth embodiment of the present invention.
FIG. 6 is a configuration diagram of a fuel cell cogeneration apparatus according to a sixth embodiment of the present invention.
FIG. 7 is a configuration diagram of a fuel cell cogeneration apparatus according to a seventh embodiment of the present invention.
FIG. 8 is a configuration diagram of a fuel cell cogeneration apparatus according to an eighth embodiment of the present invention.
FIG. 9 is a configuration diagram of a fuel cell cogeneration apparatus according to Embodiment 9 of the present invention.
FIG. 10 is a configuration diagram of a fuel cell cogeneration apparatus according to a tenth embodiment of the present invention.
FIG. 11 is a configuration diagram of a conventional fuel cell cogeneration apparatus.
[Explanation of symbols]
1 Fuel cell
5 Cooling heat recovery heat exchanger
6 Cooling circuit
9 Hot water circulation circuit
10 Hot water tank
11 Circulation pump
15 Controller (Control device)
16a Temperature detection means
16b Temperature detection means
16c Temperature detection means
17 Hydrogen production equipment
18 Exhaust gas heat recovery heat exchanger
19 Hot water storage bypass circuit
20a On-off valve (circuit switching means)
20b On-off valve (circuit switching means)
21 Check valve
22 3-way valve (3-way switching means)
23 Auxiliary heat source
24 2nd hot water tank
25 Hot water supply piping
26 Heat-use heat exchanger
27 Heatsink
28 Hot water storage amount detection means
29 4-way valve (4-way switching means)

Claims

A hot water storage circulation circuit comprising a hot water storage tank, a circulation pump, a cooling heat recovery heat exchanger provided in the cooling circuit of the fuel cell, and an exhaust gas heat recovery heat exchanger for recovering the exhaust heat of the hydrogen production device in order by piping connection; A hot water storage bypass circuit for bypassing the hot water storage tank in the hot water storage circulation circuit, a circuit switching means for switching the hot water storage bypass circuit, a temperature detection means for the fuel cell, and a signal of the temperature detection means according to the signal of the temperature detection means . When the temperature does not reach the predetermined temperature, the hot water tank is bypassed in the hot water circulation circuit, and the circulating water flows into the hot water bypass circuit, and when the temperature of the fuel cell exceeds the predetermined temperature, the circulating water is supplied to the hot water tank. And a control device for switching the circuit switching means so as to flow .

The fuel cell cogeneration apparatus according to claim 1, wherein a circuit switching means of the hot water storage bypass circuit is constituted by a check valve provided at the outlet of the hot water storage tank and a three-way switching means provided at a bypass branching portion of the hot water circulation circuit.

An auxiliary heat source provided in the hot water storage bypass circuit, and hot water storage temperature detection means provided at the hot water tank inlet of the hot water circulation circuit, and the control means is configured to connect the hot water storage bypass circuit until the temperature of the fuel cell reaches a predetermined temperature. After the circulating water flowing is heated by the auxiliary heat source and the temperature of the fuel cell becomes equal to or higher than a predetermined temperature and the circulating water flows to the hot water storage tank by the circuit switching means, according to the signal of the hot water storage temperature detection means The fuel cell cogeneration apparatus according to claim 1 or 2, wherein the flow rate flowing through the hot water storage bypass circuit and the heating amount of the auxiliary heat source are controlled by the circuit switching means so that the temperature of the hot water tank inlet becomes a predetermined temperature .

The fuel cell cogeneration apparatus according to claim 3, further comprising a second hot water storage tank provided at an outlet of an auxiliary heat source of the hot water storage bypass circuit.

The fuel cell cogeneration device according to claim 4, wherein a hot water supply pipe is provided by branching from an auxiliary heat source outlet of the hot water storage bypass circuit.

The fuel cell cogeneration apparatus according to any one of claims 1 to 5, wherein a heat-utilizing heat exchanger having a radiator for heating and drying is provided downstream of an auxiliary heat source of the hot water storage bypass circuit.

An auxiliary heat source provided at the hot water tank inlet of the hot water circulation circuit and hot water storage amount detection means provided in the hot water storage tank, and the control means has stored a predetermined amount of hot water in the hot water storage tank by the hot water storage amount detection means. The fuel cell cogeneration apparatus according to claim 1, wherein the circulating water circulating in the hot water storage circuit is heated by an auxiliary heat source until detection is made .

A temperature detecting means provided at the hot water tank inlet of the hot water circulation circuit, and a heating and drying radiator provided downstream of the auxiliary heat source of the hot water circulation circuit and upstream of the temperature detecting means provided at the hot water tank inlet. The fuel cell cogeneration apparatus according to claim 7 , further comprising a heat-use heat exchanger, wherein the control unit controls a heating amount of the auxiliary heat source so that a detection value of the temperature detection unit becomes a predetermined value .

A hot water storage circuit comprising a hot water storage tank, a circulation pump, a cooling heat recovery heat exchanger provided in a cooling circuit of the fuel cell, and an exhaust gas heat recovery heat exchanger for recovering exhaust heat of the hydrogen production device in order. One is connected to the lower outlet of the hot water tank and the suction side of the circulation pump, and the other is connected to the discharge side of the circulation pump and the upper inlet of the hot water tank. When switching, one is connected to the lower outlet of the hot water tank and the upper part of the hot water tank. The four-way switching means for connecting the inlet and connecting the other to the circulation pump suction side and the discharge side of the circulation pump, the temperature detection means for the fuel cell, and the temperature of the fuel cell according to the detected value of the temperature detection means If the temperature does not reach the predetermined temperature, one is connected to the lower outlet of the hot water tank and the upper inlet of the hot water tank, and the other is connected to the circulation pump suction side and the discharge side of the circulation pump. When the temperature exceeds the specified temperature The a control device for switching control of the four-way switching means to connect the upper inlet of the hot water storage tank and the discharge side of the circulating pump and the other is connected to the lower outlet and the suction side of the circulation pump of the hot water storage tank Fuel cell cogeneration system provided.

A hot water storage circuit comprising a hot water storage tank, a circulation pump, a cooling heat recovery heat exchanger provided in a cooling circuit of the fuel cell, and an exhaust gas heat recovery heat exchanger for recovering exhaust heat of the hydrogen production device in order. When the plug one the lower outlet of the hot water storage tank and the suction side of the circulation pump the other connects the upper inlet of the discharge side and the hot water tank of the circulation pump, the switching, one a lower outlet of the hot water storage tank circulation pump discharge side And the other is connected to the upper inlet of the hot water tank and the suction side of the circulation pump, the temperature detecting means of the fuel cell, and the temperature of the fuel cell according to the detected value of the temperature detecting means When the predetermined temperature is not reached, one is connected to the lower outlet of the hot water tank and the discharge side of the circulation pump, and the other is connected to the upper inlet of the hot water tank and the suction side of the circulation pump. When the temperature exceeds the specified temperature The a control device for switching control of the four-way switching means to connect the upper inlet of the hot water storage tank and the discharge side of the circulating pump and the other is connected to the lower outlet and the suction side of the circulation pump of the hot water storage tank providing a fuel cell cogeneration system.