JP3966790B2

JP3966790B2 - Cogeneration system

Info

Publication number: JP3966790B2
Application number: JP2002258067A
Authority: JP
Inventors: 雅之牛尾; 哲司森田; 誠児大森; 祐子木村; 裕一村瀬
Original assignee: Osaka Gas Co Ltd
Current assignee: Osaka Gas Co Ltd
Priority date: 2002-09-03
Filing date: 2002-09-03
Publication date: 2007-08-29
Anticipated expiration: 2022-09-03
Also published as: JP2004093071A

Description

【０００１】
【発明の属する技術分野】
本発明は、地域又は集合住宅を電力供給対象として発電する発電手段、その発電手段からの排熱が供給される排熱回収用熱交換器、前記地域又は集合住宅に含まれる複数の住戸を給湯対象として湯水を貯留する貯湯槽、その貯湯槽に給水する槽用給水手段、前記排熱回収用熱交換器と前記貯湯槽とにわたって湯水を循環させる排熱回収用循環手段、前記貯湯槽と前記複数の住戸とにわたる給湯用循環経路にて湯水を循環させる給湯用循環手段、及び、運転を制御する運転制御手段が設けられたコージェネレーションシステムに関する。
【０００２】
【従来の技術】
かかるコージェネレーションシステムは、通常、運転制御手段にて、１日のうちの一部の時間帯として設定される設定発電時間帯においては発電手段及び排熱回収用循環手段を作動させ、その設定発電時間帯以外の非発電時間帯においては発電手段及び排熱回収用循環手段を停止させる形態で、且つ、設定発電時間帯及び非発電時間帯においては、貯湯槽に貯留された湯水を消費すべく給湯用循環手段を作動させる形態で運転を制御するようにして、発電手段の運転中にその発電手段から発生する排熱にて貯湯槽の湯水を加熱し、その貯湯槽の湯水を給湯用循環経路を通じて循環させるものであり、各住戸においては、給湯用循環経路を循環する湯水を用いて、風呂や台所等に給湯することができるようになっている。
そして、通常、設定発電時間帯は、地域又は集合住宅に含まれる複数の住戸全体としての電力需要の多い時間帯、例えば、１８時から２４時までの時間帯に設定されるものであり、電力需要の多い時間帯は、概ね給湯需要の多い時間帯と重なるものであるので、給湯需要の多い時間帯に、発電手段の排熱にて加熱した湯水を各住戸に供給することができる。
【０００３】
かかるコージェネレーションシステムにおいては、従来、例えば、図１１に示すように、貯湯槽３を密閉式に構成し、槽用給水手段Ｗ１を、水道からの水を貯湯槽３の底部に供給する給水路８１にて構成して、貯湯槽３に常時、湯水を満水状態で貯留するように構成したものが開示されている（例えば、特許文献１参照）。
上記従来のコージェネレーションシステムでは、図１１に示すように、排熱回収用循環手段Ｃ１は、貯湯槽３と排熱回収用熱交換器２とにわたる循環経路を形成する排熱回収用流路８２と、その排熱回収用流路８２に設けた排熱回収用循環ポンプ８３とから構成し、給湯用循環手段Ｃ２は、貯湯槽３と複数の住戸とにわたる給湯用循環経路８４と、その給湯用循環経路８４に設けた給湯用循環ポンプ８５とから構成していた。尚、図１１中において、Ｋは、給湯用循環手段Ｃ２にて供給される湯水を加熱すべく、各住戸に設けられた給湯器である。
上記従来のコージェネレーションシステムでは、設定発電時間帯においては発電手段及び排熱回収用循環手段を作動させ、非発電時間帯においては発電手段及び排熱回収用循環手段を停止させる形態で運転するようにすると、設定発電時間帯及び非発電時間帯のいずれにおいても、貯湯槽が満水状態となるように槽用給水手段にて給水されることになる。
つまり、設定発電時間帯と非発電時間帯とにわたって、貯湯槽から各住戸に供給される湯水の量に相当する量の水が貯湯槽に補給される状態で、貯湯槽に満水状態となるように湯水が貯留されるものであった。
【０００４】
【特許文献１】
特開平７−３２４８０９号公報
【０００５】
【発明が解決しようとする課題】
上述のように、各住戸においては、給湯用循環経路を循環する湯水を用いて風呂や台所等に給湯するのであるが、各住戸においては、再加熱が不要な極力高温（例えば、４０°Ｃ以上）の湯が供給されると、使い易いものとなる。例えば、風呂に湯張りをする場合には、高温の湯が多量に必要となることから、再加熱が不要な高温の湯が供給されると、湯張りをし易くなる。
しかしながら、従来では、非発電時間帯においては、発電手段の排熱による加熱が停止された状態で、各住戸に供給される貯湯槽の湯水の量に相当する量の水が貯湯槽に補給されるから、貯湯槽の湯水の温度が各住戸における湯水の使用に伴って漸次低くなって、各住戸で使い難いかなり低い温度になるものである。
複数の住戸には、湯の使用時間帯が異なる種々の生活パターンの住戸が含まれるものであるが、前述のように、非発電時間帯において、貯湯槽の湯水の温度が使い難いかなり低い温度になると、非発電時間帯に湯の使用量の多い生活パターンの住戸では、設定発電時間帯に湯の使用量の多い生活パターンの住戸に比べて、供給される湯の温度がかなり低くなり、不平等となる。
又、設定発電時間帯における発電手段の排熱による湯水の加熱が、貯湯槽に満水状態で貯留されている湯水を対象として行われるものであるから、複数の住戸全体としての使用量に対して不必要に多量の湯水を対象として行われる場合があり、その場合は不必要に多量の湯水の加熱のために湯水を高温に加熱し難いものである。
【０００６】
本発明は、かかる実情に鑑みてなされたものであり、その目的は、設定発電時間帯と非発電時間帯とを通じて、複数の住戸へ使い易い高温の湯を供給することができて、湯の使用時間帯が異なる住戸が含まれる複数の住戸に対して極力平等に給湯することができ、又、複数の住戸に供給する湯温を極力高温化することができるコージェネレーションシステムを提供することにある。
【０００７】
【課題を解決するための手段】
〔請求項１記載の発明〕
請求項１に記載のコージェネレーションシステムは、地域又は集合住宅を電力供給対象として発電する発電手段、その発電手段からの排熱が供給される排熱回収用熱交換器、前記地域又は集合住宅に含まれる複数の住戸を給湯対象として湯水を貯留する貯湯槽、その貯湯槽に給水する槽用給水手段、前記排熱回収用熱交換器と前記貯湯槽とにわたって湯水を循環させる排熱回収用循環手段、前記貯湯槽と前記複数の住戸とにわたる給湯用循環経路にて湯水を循環させる給湯用循環手段、及び、運転を制御する運転制御手段が設けられたものであって、
前記貯湯槽が、上部が開口した開放型に構成され、
前記運転制御手段が、
１日のうちの一部の時間帯として設定される設定発電時間帯においては前記発電手段及び前記排熱回収用循環手段を作動させ、その設定発電時間帯以外の非発電時間帯においては前記発電手段及び前記排熱回収用循環手段を停止させる形態で、且つ、
前記貯湯槽の目標貯留量として前記非発電時間帯において消費又は略消費可能な貯留量が設定されて、前記設定発電時間帯においてはその目標貯留量を貯留すべく前記槽用給水手段を作動させかつ前記非発電時間帯においては前記槽用給水手段を停止させ、且つ、前記設定発電時間帯及び前記非発電時間帯においては、前記貯湯槽に貯留された湯水を消費すべく前記給湯用循環手段を作動させる形態で運転を制御するように構成されている点を特徴構成とする。
即ち、１日のうちの一部の時間帯として設定される設定発電時間帯においては発電手段及び排熱回収用循環手段が作動され、その設定発電時間帯以外の非発電時間帯においては発電手段及び排熱回収用循環手段が停止され、並びに、設定発電時間帯においては、貯留量が非発電時間帯において消費又は略消費可能な貯留量に設定された目標貯留量になるように貯湯槽に給水されながら、貯湯槽の湯水が発電手段からの排熱にて加熱される状態で、貯湯槽の湯水が給湯用循環経路に循環されることとなり、非発電時間帯においては、貯湯槽への給水が停止される状態で、貯湯槽の湯水が給湯用循環経路に循環されることとなり、設定発電時間帯と非発電時間帯とを通じて、各住戸においては、給湯用循環経路を循環する貯湯槽の湯水が使用されることとなる。
つまり、非発電時間帯においては、貯湯槽への給水が停止されることから、貯湯槽の湯水の温度の低下を抑制することができるようになり、非発電時間帯においても、設定発電時間帯と同様に、貯湯槽に使い易い高温の湯を貯留することが可能となり、又、設定発電時間帯における発電手段の排熱による湯水の加熱が、非発電時間帯において消費又は略消費可能な貯留量に設定された目標貯留量で貯湯槽に貯留される湯水を対象として行われるものであるから、複数の住戸全体としての使用量に対して不必要に多量の湯水を対象として行われるような状態を回避できて、貯湯槽の湯水を極力高温に加熱し易い。
従って、設定発電時間帯と非発電時間帯とを通じて、複数の住戸へ使い易い高温の湯を供給することができて、湯の使用時間帯が異なる住戸が含まれる複数の住戸に対して極力平等に給湯することができ、又、複数の住戸に供給する湯温を極力高温化することができるコージェネレーションシステムを提供することができるようになった。
【０００８】
〔請求項２記載の発明〕
請求項２に記載のコージェネレーションシステムは、請求項１において、前記複数の住戸のそれぞれに、前記給湯用循環手段を通じて供給される湯水を用いて湯水需要部に給湯する給湯器が設けられ、
給水源からの水を前記給湯用循環経路に供給する循環用給水手段が設けられ、
前記給湯用循環手段が、前記貯湯槽の湯水を前記給湯用循環経路にて循環させる貯湯槽湯水循環状態と、前記貯湯槽の湯水の循環を停止させて前記循環用給水手段にて前記給湯用循環経路に給水する給水状態とに切り換え自在に構成され、
前記運転制御手段は、前記非発電時間帯において、前記貯湯槽の貯留量が設定下限貯留量になると、前記給湯用循環手段を前記貯湯槽湯水循環状態から前記給水状態に切り換えるように構成されている点を特徴構成とする。
即ち、貯湯槽の貯留量が設定下限貯留量になると、給湯用循環経路を通じての貯湯槽の湯水の循環が停止されて、給湯用循環経路には給水源からの水が供給され、各住戸においては、給湯用循環経路を通じて供給される給水源からの水を用いて給湯器にて湯水需要部に給湯される。
つまり、貯湯槽の貯留量が設定下限貯留量になって、貯湯槽からの各住戸への湯水の供給が行えなくなっても、各住戸においては、給湯用循環経路を通じて供給される給水源からの水を用いて給湯器にて給湯を行うことができる。
従って、各住戸において給湯が途絶えるといった不具合の発生を回避しながら、請求項１に記載の特徴構成による利点を得ることができる。
【０００９】
〔請求項３記載の発明〕
請求項３に記載のコージェネレーションシステムは、請求項２において、前記貯湯槽の湯水を加熱する貯湯槽用補助加熱手段が設けられ、
前記運転制御手段は、前記非発電時間帯において、前記貯湯槽の貯留量が前記設定下限貯留量になると、又は、前記貯湯槽の貯留量が前記設定下限貯留量以下にならなくとも前記非発電時間帯における設定終期になると、前記給湯用循環手段を前記貯湯槽湯水循環状態から前記給水状態に切り換え、且つ、前記貯湯槽の湯水を、湯水の水質を維持することが可能な水質維持温度にまで加熱するように、前記貯湯槽用補助加熱手段を加熱作動させる貯湯槽水質維持運転を実行するように構成されている点を特徴構成とする。
即ち、非発電時間帯において、貯湯槽の貯留量が設定下限貯留量以下になると、あるいは、貯湯槽の貯留量が設定下限貯留量以下にならなくとも非発電時間帯における設定終期になると、貯湯槽の湯水の循環が停止されて、貯湯槽用補助加熱手段により貯湯槽の湯水を水質維持温度（例えば６０°Ｃ程度）にまで加熱する貯湯槽水質維持運転が実行される。
そして、貯湯槽水質維持運転により、貯湯槽の湯水が水質維持温度にまで加熱されるので、各住戸に供給される湯水の水質の低下を抑制することができる。
又、水質維持のために貯湯槽の湯水を水質維持温度にまで加熱する貯湯槽水質維持運転を、加熱対象の湯水の量が少なくなった状態で行うので、水質維持のための消費エネルギーを低減することが可能となる。
従って、ランニングコストを低廉化しながら、各住戸に供給される湯水の水質の低下を抑制することができるようになった。
【００１０】
〔請求項４記載の発明〕
請求項４に記載のコージェネレーションシステムは、請求項３において、前記貯湯槽が、主貯留部とその主貯留部よりも横断面積が小さい小貯留部とを備えて構成され、
それら主貯留部及び小貯留部が、互いに連通して、前記貯湯槽の貯留量が前記設定下限貯留量以下のときは全量が前記小貯留部で貯留され、前記貯湯槽の貯留量が前記設定下限貯留量より多いときは前記設定下限貯留量が前記小貯留部にて貯留され且つ前記設定下限貯留量を越える分が前記主貯留部にて貯留されるように設けられている点を特徴構成とする。
即ち、貯湯槽の貯留量が設定下限貯留量になると、湯水の全量が小貯留部に貯留される状態になり、又、貯湯槽の貯留量が設定下限貯留量以下にならなくとも非発電時間帯における設定終期になると、貯湯槽の貯留量は設定下限貯留量に近い状態にまで減少しているので、湯水の略全量が小貯留部に貯留される状態になる。
つまり、貯湯槽水質維持運転においては、湯水の全量又は略全量が、主貯留部よりも横断面積が小さい小貯留部に貯留される状態にして、貯湯槽における湯水の貯留量を極力少なくしながらも、貯留水位を極力高くすることが可能となるので、ポンプ等により、加熱対象の湯水を貯湯槽用補助加熱手段に対して適切に循環させると共に効果的に撹拌することを可能にしながら、加熱対象の湯水の量を少なくすることが可能となる。
従って、少ない湯水を効果的に撹拌しながら貯湯槽用補助加熱手段にて水質維持温度にまで加熱することになるので、水質維持のための消費エネルギーを更に低減することが可能となる。
【００１１】
〔請求項５記載の発明〕
請求項５に記載のコージェネレーションシステムは、請求項２〜４のいずれかにおいて、前記給湯用循環手段が、前記貯湯槽の湯水の循環を停止させて、前記給湯用循環経路内の湯水をその給湯用循環経路の全長又は略全長にわたって、前記循環用給水手段にて供給される水にて置換する水置換状態に切り換え自在に構成され、
前記運転制御手段は、前記給湯用循環手段を前記貯湯槽湯水循環状態にて運転させるのを停止してから、次に前記給湯用循環手段を前記貯湯槽湯水循環状態にて運転させるまでの間に、前記給湯用循環手段を前記水置換状態にて運転させる水置換運転を実行するように構成されている点を特徴構成とする。
即ち、貯湯槽湯水循環状態が終了してから、次の貯湯槽湯水循環状態が開始されるまでの間に、給湯用循環経路内の湯水をその給湯用循環経路の全長又は略全長にわたって、給水源からの新しい水にて置換する水置換運転が実行される。
つまり、水置換運転により、給湯用循環経路内の湯水がその給湯用循環経路の全長又は略全長にわたって、給水源からの新しい水に置換されるので、各住戸に供給される湯水の水質の低下を抑制することができる。
そして、水置換運転を、貯湯槽湯水循環状態が終了してから、次の貯湯槽湯水循環状態が開始されるまでの間に実行させることから、本来給湯需要の多い時間帯に対応して行われる貯湯槽湯水循環状態を中断して、各住戸への給湯に支障を来たすといった不具合を生じさせることがない。
従って、各住戸への給湯に支障を来たすといった不具合を生じさせること無く、給湯用循環経路内の湯水をその給湯用循環経路の全長又は略全長にわたって、給水源からの新しい水に置換して、各住戸に供給される湯水の水質の低下を抑制することができるようになった。
【００１２】
〔請求項６記載の発明〕
請求項６に記載のコージェネレーションシステムは、請求項２〜５のいずれかにおいて、前記給湯用循環経路の湯水を加熱する循環経路用補助加熱手段が設けられ、
前記運転制御手段は、前記給湯用循環手段を前記貯湯槽湯水循環状態にて運転させるのを停止してから、次に前記給湯用循環手段を前記貯湯槽湯水循環状態にて運転させるまでの間に、前記給湯用循環経路内の湯水を、湯水の水質を維持することが可能な水質維持温度にまで加熱するように、前記循環経路用補助加熱手段を加熱作動させる循環経路水質維持運転を実行するように構成されている点を特徴構成とする。
即ち、貯湯槽湯水循環状態が終了してから、次の貯湯槽湯水循環状態が開始されるまでの間に、循環経路用補助加熱手段により、給湯用循環経路内の湯水を水質維持温度にまで加熱する循環経路水質維持運転が実行される。
つまり、循環経路水質維持運転により、給湯用循環経路内の湯水が水質維持温度にまで加熱されるので、各住戸に供給される湯水の水質の低下を抑制することができる。
そして、循環経路水質維持運転を、各住戸における給湯需要の少ない時間帯であるところの、貯湯槽湯水循環状態が終了してから次の貯湯槽湯水循環状態が開始されるまでの間において実行させることにより、貯湯槽湯水循環状態が実行されている間に、給湯用循環経路から各住戸に供給される湯の量を少なくすることが可能となって、循環経路水質維持運転にて消費されるエネルギーを少なくすることが可能となる。
従って、消費エネルギーを低減しながら、給湯用循環経路内の湯水を水質維持温度にまで加熱して、各住戸に供給される湯水の水質の低下を抑制することができるようになった。
【００１３】
【発明の実施の形態】
〔第１実施形態〕
以下、図面に基づいて、本発明の第１実施形態を説明する。
図１に示すように、コージェネレーションシステムは、集合住宅を電力供給対象として発電する発電手段としての発電機１、その発電機１からの排熱が供給される排熱回収用熱交換器２、集合住宅に含まれる複数の住戸Ｈを給湯対象として湯水を貯留する貯湯槽３、その貯湯槽３に給水する槽用給水手段Ｗ１、排熱回収用熱交換器２と貯湯槽３とにわたって湯水を循環させる排熱回収用循環手段Ｃ１、貯湯槽３と集合住宅に含まれる複数の住戸Ｈとにわたる給湯用循環経路Ｒにて湯水を循環させる給湯用循環手段Ｃ２、給水源としての受水槽５からの水を給湯用循環経路Ｒに供給する循環用給水手段Ｗ２、集合住宅に含まれる複数の住戸Ｈのそれぞれに給水する住戸用給水手段Ｗ３、及び、コージェネレーションシステムの運転を制御する運転制御手段としての運転制御部Ｕを設け、並びに、集合住宅に含まれる複数の住戸Ｈのそれぞれに、給湯用循環手段Ｃ２を通じて供給される湯水を用いて住戸Ｈにおける各湯水需要部に供給する給湯器Ｋを設けて構成してある。
【００１４】
又、コージェネレーションシステムには、貯湯槽３の湯水を加熱する貯湯槽用補助加熱手段Ｂ１、給湯用循環経路Ｒを通流する湯水を加熱する循環経路用補助加熱手段Ｂ２、及び、発電機１からの排熱が供給されて、給湯用循環経路Ｒを通流する湯水を加熱する補助加熱用熱交換器６を設けてある。
【００１５】
更に、コージェネレーションシステムには、商用電源６１からの電力を一括して受電する受変電設備６２と、発電機１を商用電源６１と系統連系させる連系装置６３とを設け、発電機１及び商用電源６１からの電力を、共用部における電力消費機器や、集合住宅に含まれる各住戸Ｈの電力消費機器に供給するように給電線６４を配線してある。
【００１６】
説明を加えると、発電機１は、共用部用ガス供給路７を通じて供給される都市ガスを燃料とするガスエンジン（図示省略）を備えて、そのガスエンジンにて駆動する回転式に構成してある。
そして、ガスエンジンと排熱回収用熱交換器２とにわたってエンジン冷却水を循環させる冷却水循環路８を設け、更に、エンジン冷却水の一部を分流して補助加熱用熱交換器６に循環させることが可能なように、冷却水循環路８と補助加熱用熱交換器６とを冷却水分流三方弁Ｖ１を介して分流循環路８ｂにて接続し、冷却水循環路８に冷却水循環ポンプＰ１を設けてある。そして、冷却水循環ポンプＰ１を作動させることにより、エンジン冷却水をガスエンジンと排熱回収用熱交換器２及び補助加熱用熱交換器６の夫々とにわたって循環させるように構成してある。
【００１７】
槽用給水手段Ｗ１は、受水槽５から貯湯槽３に給水する槽用給水路９と、その槽用給水路９に設けた槽用給水ポンプＰ２にて構成してある。
槽用給水ポンプＰ２を作動させると、槽用給水手段Ｗ１が作動することになり、受水槽５の貯留水が槽用給水路９を通じて貯湯槽３に給水され、槽用給水ポンプＰ２を停止させると、槽用給水手段Ｗ１の作動が停止することになる。
受水槽５には、水道水が供給され、詳細な説明及び図示は省略するが、受水槽５の貯留水位が設定水位になるように水道水の供給が断続されるようになっている。
【００１８】
貯湯槽３は、主貯留部３ｍとその主貯留部３ｍよりも横断面積が小さい小貯留部３ｓとを備えて構成し、それら主貯留部３ｍ及び小貯留部３ｓを、互いに連通して、貯湯槽３の貯留量が設定下限貯留量以下のときは全量が小貯留部３ｓで貯留され、貯湯槽３の貯留量が設定下限貯留量より多いときは設定下限貯留量が小貯留部３ｓにて貯留され且つ設定下限貯留量を越える分が主貯留部３ｍにて貯留されるように設けてある。ちなみに、設定下限貯留量は、例えば、貯湯槽３における満水状態での貯留量の１０％程度に設定する。
【００１９】
具体的には、上部が開口した開放型の主貯留部３ｍと、その主貯留部３ｍよりも横断面積が小さい密閉型の小貯留部３ｓを、互いに別体で、且つ、小貯留部３ｓが主貯留部３ｍの底部よりも下方に位置する状態で設け、主貯留部３ｍの底部と小貯留部３ｓの上部とを連通路３ｃにて連通させてある。
又、貯留槽３の主貯留部３ｍには、水位センサＬを設けてある。
【００２０】
排熱回収用循環手段Ｃ１は、貯湯槽３の小貯留部３ｓの底部から取り出した湯水を排熱回収用熱交換器２を経由して主貯留部３ｍの上部から戻すように流すべく配管した排熱回収用循環経路１０と、その排熱回収用循環経路１０における排熱回収用熱交換器２よりも下流側部分から分岐させて湯水を小貯留部３ｓに戻す分岐経路１０ｂと、その分岐部分に設けた槽湯水循環切換三方弁Ｖ２と、排熱回収用循環経路１０に設けた排熱回収用循環ポンプＰ３とを備えて構成してある。
つまり、排熱回収用循環ポンプＰ３を作動させると、排熱回収用循環手段Ｃ１が作動することになり、排熱回収用循環ポンプＰ３の作動を停止させると、排熱回収用循環手段Ｃ１が停止することになり、並びに、槽湯水循環切換三方弁Ｖ２の切り換えにより、排熱回収用循環経路１０の復路部分（排熱回収用熱交換器２の出口に接続される流路部分）を通流する湯水を主貯留部３ｍに戻す通常循環状態と、排熱回収用循環経路１０の復路部分を通流する湯水を小貯留部３ｓに戻す槽昇温時循環状態とに切り換え自在に構成してある。
【００２１】
給湯用循環手段Ｃ２は、貯湯槽３と集合住宅に含まれる複数の住戸Ｈとにわたる給湯用循環経路Ｒと、その給湯用循環経路Ｒに設けた上流側循環ポンプＰ４及び下流側循環ポンプＰ５とを備えて構成し、各住戸Ｈには、給湯用循環経路Ｒを流れる湯水を各住戸Ｈに供給する住戸用湯水供給路１１を接続し、各住戸用湯水供給路１１には、各住戸Ｈに供給される湯水の流量を検出する住戸別給湯量センサＱ３を設けてある。
【００２２】
給湯用循環経路Ｒについて説明を加える。貯湯槽３の小貯留部３ｓから取り出した湯水を集合住宅に含まれる複数の住戸Ｈを経由して主貯湯部３ｍの上部に戻すように流すべく配管して、槽経由循環路４を設け、その槽経由循環路４における住戸経由箇所よりも下流側に、槽戻し停止三方弁Ｖ３を設け、その槽戻し停止三方弁Ｖ３と槽経由循環路４における住戸経由箇所よりも上流側とを槽バイパス路１２にて接続し、更に、槽経由循環路４における槽バイパス路１２の接続個所よりも上流側に、逆止弁１３を設けて、槽戻し停止三方弁Ｖ３の切り換えにより、槽経由循環路４を通流する湯水を貯湯槽３に流入させる槽戻し状態と、槽経由循環路４を通流する湯水を貯湯槽３に流入させるのを停止する槽戻し停止状態とに切り換え自在なように構成してある。
上流側循環ポンプＰ４は、槽経由循環路４の住戸経由箇所よりも上流側における槽バイパス路１２の接続個所よりも上流側に設け、下流側循環ポンプＰ５は、槽経由循環路４における住戸経由箇所よりも下流側で且つ槽戻し停止三方弁Ｖ３よりも上流側に設けてある。
【００２３】
そして、槽戻し停止三方弁Ｖ３を前記槽戻し停止状態に切り換えて、上流側循環ポンプＰ４及び下流側循環ポンプＰ５を作動させると、貯湯槽３から取り出された湯水は、槽経由循環路４を複数の住戸Ｈを経由して流れ、更に、槽戻し停止三方弁Ｖ３から槽バイパス路１２を流れて槽経由循環路４に戻る貯湯槽迂回経路にて循環することになり、その貯湯槽迂回経路を流れる湯水が各住戸Ｈにて使用されるのに応じて、上流側循環ポンプＰ４により、貯湯槽３の湯水が前記貯湯槽迂回経路に補充されることになる。
つまり、貯湯槽３と複数の住戸Ｈとにわたる給湯用循環経路Ｒは、槽経由循環路４及び槽バイパス路１２を用いて、貯湯槽３を迂回する状態で複数の住戸Ｈを経由する貯湯槽迂回経路を形成するように構成し、給湯用循環手段Ｃ２は、貯湯槽３の湯水を給湯用循環経路Ｒに補充しながら給湯用循環経路Ｒを通じて循環させるように構成してある。
【００２４】
又、槽経由循環路４における住戸経由箇所よりも下流側で且つ槽戻し停止三方弁Ｖ３よりも上流側に、補助加熱用熱交換器６を設けて、その補助加熱用熱交換器６により、給湯用循環経路Ｒを通流する湯水を加熱するように構成してある。つまり、給湯用循環経路Ｒを通流する湯水を、補助加熱用熱交換器６にて発電機１の排熱にて加熱することにより、放熱による温度低下を抑制するように構成してある。
【００２５】
循環用給水手段Ｗ２は、槽経由循環路４の住戸経由箇所よりも上流側における槽バイパス路１２の接続個所よりも下流側に接続されて受水槽５からの水を給湯用循環経路Ｒに供給する循環給水路１４と、槽経由循環路４における循環給水路１４の接続部分に設けた給水切換三方弁Ｖ４と、循環給水路１４に設けた循環兼住戸用給水ポンプＰ６とを備えて構成してある。
つまり、給水切換三方弁Ｖ４により、貯湯槽３からの湯水の通流を停止して、循環給水路１４から給湯用循環経路Ｒに給水する給水路接続状態と、循環給水路１４からの給水を停止して、貯湯槽３からの湯水を通流させる給水路遮断状態とに切り換え自在なように構成してある。
【００２６】
又、循環給水路１４から住戸用給水路１５を分岐させて、その住戸用給水路１５を複数の住戸Ｈの夫々に給水するように配管してあり、住戸用給水手段Ｗ３は、循環給水路１４と住戸用給水路１５と循環兼住戸用給水ポンプＰ６とを備えて構成してある。
【００２７】
貯湯槽用補助加熱手段Ｂ１と循環経路用補助加熱手段Ｂ２とを兼用する補助給湯器Ｂを設けてある。
その補助給湯器Ｂは、第１及び第２の二つの熱交換器７１，７２と、それら第１及び第２熱交換器７１，７２を加熱するガスバーナ７３と、そのガスバーナ７３に燃焼用空気を通風する送風機７４を備えて構成してある。
第１熱交換器７１の入口には、その第１熱交換器７１に供給される湯水の流量を検出する第１給水量センサＱ１を設け、第１熱交換器７１の出口には、その第１熱交換器７１から出湯される湯水の温度を検出する第１出湯温度センサＴ１を設け、第２熱交換器７２の入口には、その第２熱交換器７２に供給される湯水の流量を検出する第２給水量センサＱ２を設け、第２熱交換器７２の出口には、その第２熱交換器７２から出湯される湯水の温度を検出する第２出湯温度センサＴ２を設けてある。
又、ガスバーナ７３には共用部用ガス供給路７を接続し、その共用部用ガス供給路７には、ガス供給を断続するガス断続弁７５、及び、ガス供給量を調整するガス比例弁７６を設けてある。
【００２８】
補助給湯器Ｂの作動は、運転制御部Ｕにて行われ、その運転制御部Ｕは、第１熱交換器７１及び第２熱交換器７２のうちの少なくとも一方に湯水が流れて、第１給水量センサＱ１及び第２給水量センサＱ２のうちの少なくとも一方の検出湯水流量が設定量以上になることに基づいて、送風機７４を作動させると共にガス断続弁７５を開弁し、図示しない点火プラグを作動させて、ガスバーナ７３を点火させ、後述するようにガス比例弁７６の開度調節により燃焼量を調節し、第１給水量センサＱ１及び第２給水量センサＱ２の両方の検出湯水流量が設定量よりも少なくなると、ガス断続弁７５を閉弁してガスバーナ７３を消火させ、続いて、送風機７４を停止させる。
【００２９】
そして、給湯用循環経路Ｒを通流する湯水を第１熱交換器７１に通流させてから給湯用循環経路Ｒに戻して、各住戸Ｈに供給するように、槽経由循環路４の住戸経由個所よりも上流側部分と第１熱交換器７１とを補助加熱流路１６にて接続し、槽経由循環路４と補助加熱流路１６との接続部には、槽経由循環路４を通流する湯水を第１熱交換器７１に通流させる補助加熱状態と、通流させない補助加熱停止状態とに切り換える補助加熱切換三方弁Ｖ５を設けてある。
槽経由循環路４における補助加熱流路１６との接続個所よりも上流側の個所に、貯湯槽３から取り出される湯水の温度を検出する貯湯槽取り出し温度センサＴ３を設け、槽経由循環路４における住戸経由個所よりも上流側で且つ補助加熱流路１６の接続個所よりも下流側に、各住戸Ｈに供給される湯水の温度を検出する住戸供給温度センサＴ４を設けてある。
【００３０】
又、排熱回収用循環経路１０における往路部分（排熱回収用熱交換器２の入口に接続される流路部分）を通流する湯水を排熱回収用熱交換器２を迂回させて、第２熱交換器７２を通流させてから、排熱回収用循環経路１０における復路部分（排熱回収用熱交換器２の出口に接続される流路部分）に戻すように、排熱回収用循環経路１０と第２熱交換器７２とを槽昇温用流路１７にて接続し、槽昇温用流路１７と排熱回収用循環経路１０との接続部分の夫々には、湯水を熱回収用熱交換器２に通流させる排熱回収状態と、湯水を第２熱交換器７１に通流させる槽昇温状態とに切り換える貯湯槽側槽昇温切換三方弁Ｖ６を設け、槽昇温用流路１７には、槽昇温用ポンプＰ７を設けてある。又、排熱回収用循環経路１０における往路部分の貯湯槽側槽昇温切換三方弁Ｖ６よりも上流側箇所には、貯湯槽３の小貯留部３ｓからの湯水の取り出し温度を検出する小貯留部取り出し温度センサＴ５を設けてある。
【００３１】
更に、槽昇温用流路１７における往路部分（第２熱交換器７２の入口に接続される部分）を通流する湯水を分流して第１熱交換器７１に通流させてから、槽昇温用流路１７における復路部分（第２熱交換器７２の出口に接続される部分）に戻すように、槽昇温用流路１７と補助加熱流路１６とを分流流路１８にて接続し、補助加熱流路１６と分流流路１８との接続部分の夫々には、第１熱交換器７１に給湯用循環経路Ｒからの湯水を通流させる補助加熱状態と、第１熱交換器７１に槽昇温用流路１７からの湯水を通流させる槽昇温状態とに切り換える給湯器側槽昇温切換三方弁Ｖ７を設けてある。
【００３２】
そして、槽戻し停止三方弁Ｖ３を前記槽戻し停止状態に切り換え且つ給水切換三方弁Ｖ４を前記給水路遮断状態に切り換えた状態で、上流側循環ポンプＰ４及び下流側循環ポンプＰ５を作動させると、貯湯槽３の湯水を給湯用循環経路Ｒにて循環させる貯湯槽湯水循環状態となる。
又、槽戻し停止三方弁Ｖ３を前記槽戻し停止状態に切り換え且つ給水切換三方弁Ｖ４を前記給水路接続状態に切り換え、並びに、上流側循環ポンプＰ４及び下流側循環ポンプＰ５を停止させた状態で、循環兼住戸用給水ポンプＰ６を作動させると、給水源としての受水槽５からの水を給湯用循環経路Ｒに供給する給水状態になる。
又、給水切換三方弁Ｖ４を前記給水路接続状態に切り換え、補助加熱切り換え三方弁Ｖ５を前記補助加熱停止状態に切り換え、槽戻し停止三方弁Ｖ３を前記槽戻し状態に切り換え、並びに、上流側循環ポンプＰ４及び下流側循環ポンプＰ５を停止させた状態で、循環兼住戸用給水ポンプＰ６を設定水置換時間の間作動させると、貯湯槽３の湯水の循環を停止させて、給水源としての受水槽５からの水を給湯用循環経路Ｒを通じて貯湯槽３に供給するように流して、給湯用循環経路Ｒ内の湯水をその給湯用循環経路Ｒの略全長にわたって、循環用給水手段Ｗ２にて供給される水にて置換する水置換状態となる。
つまり、給湯用循環手段Ｃ２は、前記貯湯槽湯水循環状態と前記給水状態と前記水置換状態とに切り換え自在なように構成してある。
【００３３】
更に、給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態に切り換えた状態で、補助加熱切換三方弁Ｖ５を補助加熱状態に切り換え、給湯器側槽昇温切換三方弁Ｖ７を前記補助加熱状態に切り換えて、バーナ７３を燃焼させると、給湯用循環経路Ｒを通流する湯水を第１熱交換器７１にて加熱することができる。
又、槽湯水循環切換三方弁Ｖ２を前記槽昇温時循環状態に切り換え、貯湯槽側槽昇温切換三方弁Ｖ６及び給湯器側槽昇温切換三方弁Ｖ７を夫々前記槽昇温状態に切り換え、排熱回収用循環ポンプＰ３及び槽昇温用ポンプ７を作動させて、バーナ７３を燃焼させると、小貯留部３ｓの湯水を第１及び第２の両熱交換器７１，７２に通流させる状態で循環させて、加熱することができる。
【００３４】
各住戸Ｈには、都市ガスを供給する住戸用ガス供給路１９を接続してある。
そして、各住戸Ｈにおいては、給湯器Ｋに、住戸用ガス供給路１９、給湯用循環経路Ｒから分岐した住戸用湯水供給路１１及び住戸用給水路１５を接続して、給湯器Ｋにて、給湯用循環手段Ｃ２を通じて供給される湯水及び住戸用給水手段Ｗ３を通じて供給される水を用いて湯水需要部に給湯するように構成してある。
【００３５】
次に、図６に基づいて、各住戸Ｈに設ける給湯器Ｋについて説明する。
給湯器Ｋは、住戸用湯水供給路１１から供給される湯水と住戸用給水路１５から供給される水とを混合する混合部Ｋｍと、その混合部Ｋｍから湯水が加熱対象として供給される加熱部Ｋｈと、給湯目標温度を設定する給湯温度設定部等を備えたリモコン操作部３１を備えて構成してある。
【００３６】
加熱部Ｋｈは、混合部Ｋｍから給水路３２を通じて供給される湯水を加熱して、加熱後の湯水を給湯路３３に供給する給湯用熱交換器３４と、追焚用循環路３５を通流する浴槽（図示省略）の湯水を加熱する追焚用熱交換器３６と、それら給湯用熱交換器３４及び追焚用熱交換器３６を加熱するガスバーナ３７と、加熱部Ｋｈの作動を制御する加熱制御部３８等を備えて構成してある。
【００３７】
ガスバーナ３７には、住戸用ガス供給路１９を接続し、その住戸用ガス供給路１９には、ガス供給を断続するガス断続弁３９、及び、ガス供給量を調整するガス比例弁４０を設けてある。
【００３８】
給水路３２には、供給される湯水の温度を検出する給水温度センサ４１、供給される湯水の流量を検出する給水量センサ４２を設け、給水路３２と給湯路３３とを給水バイパス路４３にて接続してある。
給湯路３３には、上流側から順に、給湯用熱交換器３４からの湯水と給水バイパス路４３からの水との混合比を調整するミキシング弁４５、湯水の量を調整する水比例弁５０と、ミキシング弁４５にて混合された湯水の温度を検出する給湯温度センサ４４を設け、給湯路３３の先端には、給湯栓４９を接続してある。
給湯路３３から分岐した湯張り路４６を追焚用循環路３５における往路部分に接続し、湯張り路４６には湯張り用開閉弁４７を設けてある。
又、追焚用循環路３５における復路部分には、浴槽水を循環させる浴槽用循環ポンプ４８を設けてある。
【００３９】
混合部Ｋｍは、住戸用湯水供給路１１（即ち、給湯用循環手段Ｃ２）から供給される湯水と住戸用給水路１５（即ち、住戸用給水手段Ｗ３）から供給される水との混合比を調整するミキシング弁５１と、住戸用湯水供給路１１からミキシング弁５１への湯水供給を断続する湯水供給路開閉弁５２と、住戸用湯水供給路１１からミキシング弁５１へ供給される湯水の温度（以下、循環湯水温度と称する場合がある）を検出する循環湯水温度センサ５３と、住戸用給水路１５からミキシング弁５１へ供給される水の温度（混合部給水温度と称する場合がある）を検出する給水温度センサ５４と、ミキシング弁５１から流出した湯水の温度（以下、混合湯水温度と称する場合がある）を検出する混合温度センサ５５と、混合部Ｋｍの作動を制御する混合制御部５６等を備えて構成してある。
【００４０】
次に、加熱制御部３８及び混合制御部５６の制御動作について説明する。
加熱制御部３８は、リモコン操作部３１及び混合制御部５６夫々との間で各種の制御情報を通信するように構成するように構成してある。
リモコン操作部３１の運転スイッチがオンされると、加熱制御部３８及び混合制御部５６夫々の制御が可能となり、湯水供給路開閉弁５２が開かれた運転可能状態となる。
そして、給湯栓４９が開かれて、給水量センサ４２の検出湯水流量が設定量以上になると、加熱制御部３８は、混合制御部５６に対して、リモコン操作部３１にて設定された給湯目標温度を送信し、混合制御部５６は、循環湯水温度センサ５３にて検出された循環湯水温度と加熱制御部３８から送られてきた給湯目標温度とを比較して、循環湯水温度が給湯目標温度に対して設定温度差Δｔ低い温度よりも高い温度（以下、非燃焼制御用温度と称する場合がある）のときは、その旨を、循環湯水温度が給湯目標温度より設定温度差Δｔ以上低い温度（以下、燃焼制御用温度と称する場合がある）のときはその旨をそれぞれ加熱制御部３８に送信する。
又、混合制御部５６には、予め、設定混合温度を設定して記憶させてある。
【００４１】
設定温度差Δｔは、加熱対象の湯水を給湯目標温度に加熱するのに必要なガスバーナ３７の燃焼量が、そのガスバーナ３７の最小燃焼量（詳細は後述）よりも多くなる状態に対応する温度差に設定してあり、その設定温度差Δｔとしては、リモコン操作部３１で設定される給湯目標温度が予め設定してある通常給湯目標温度範囲（例えば３７〜４４°Ｃ）のときに対応する通常給湯目標温度用の設定温度差Δｔ（例えば２°Ｃ）と、リモコン操作部３１で設定される給湯目標温度が予め設定してある高温給湯目標温度（例えば６０°Ｃ）のときに対応する高温給湯目標温度用の設定温度差Δｔ（例えば３°Ｃ）との２種類を設定してある。
又、設定混合温度は、給湯目標温度よりも設定温度差Δｔ以上低くなるように設定し、その設定混合温度としては、リモコン操作部３１で設定される給湯目標温度が前記通常給湯目標温度範囲のときに対応するものであり、その通常給湯目標温度範囲よりも設定温度差Δｔ以上低い温度に設定した低設定混合温度（例えば３０°Ｃ）と、リモコン操作部３１で設定される給湯目標温度が前記高温給湯目標温度のときに対応する高設定混合温度（例えば４５°Ｃ）との２種類を設定してある。
【００４２】
給湯栓４９が開かれて給水量センサ４２の検出湯水流量が設定量以上になることに基づいて、加熱制御部３８から給湯目標温度が送信されてくると、混合制御部５６は、循環湯水温度センサ５３にて検出される循環湯水温度と給湯目標温度とを比較して、循環湯水温度が前記非燃焼制御用温度のときは、循環湯水温度センサ５３、給水温度センサ５４及び混合温度センサ５５夫々の検出温度に基づいて、混合温度センサ５５にて検出される混合湯水温度が給湯目標温度になるようにミキシング弁５１を調整するミキシング制御を実行して、住戸用湯水供給路１１からの湯水と住戸用給水路１５からの水を混合し、且つ、循環湯水温度が前記非燃焼制御用温度である旨を加熱制御部３８に送信する。
加熱制御部３８は、混合制御部５６から循環湯水温度が前記非燃焼制御用温度である旨が送信されてくると、ガスバーナ３７を燃焼停止状態とする。
従って、混合部Ｋｍから加熱部Ｋｈに供給された湯水は加熱部Ｋｈにて加熱されずに給湯栓４９から出湯することになり、給湯栓４９からは給湯目標温度又は略給湯目標温度の湯水が出湯する。
【００４３】
例えば、給湯目標温度が４０°Ｃに設定されているときは、循環湯水温度が、給湯目標温度の４０°Ｃよりも設定温度差Δｔ、即ち２°Ｃ低い３８°Ｃよりも高いときが、前記非燃焼制御用温度となる。そして、循環湯水温度が３８°Ｃよりも高く、４０°Ｃ以下の範囲では、住戸用湯水供給路１１からの湯水が、住戸用給水路１５からの水が混合されること無くそのまま出湯され、循環湯水温度が４０°Ｃよりも高いときは、混合湯水温度が給湯目標温度になるように、住戸用湯水供給路１１からの湯水に住戸用給水路１５からの水が混合されて出湯される。
【００４４】
一方、循環湯水温度が燃焼制御用温度のときは、循環湯水温度センサ５３、給水温度センサ５４及び混合温度センサ５５夫々の検出温度に基づいて、混合温度センサ５５にて検出される混合湯水温度が、給湯目標温度が通常給湯目標温度範囲のときは低設定混合温度になるように、あるいは、給湯目標温度が高温給湯目標温度のときは高設定混合温度になるように、ミキシング弁５１を調整するミキシング制御を実行して、住戸用湯水供給路１１からの湯水と住戸用給水路１５からの水を混合し、且つ、循環湯水温度が燃焼制御用温度である旨を加熱制御部３８に送信する。
加熱制御部３８は、混合制御部５６から循環湯水温度が燃焼制御用温度である旨が送信されてくると、ガスバーナ３７を燃焼させ、給湯目標温度、給水温度センサ４１の検出温度及び給水量センサ４２の検出給水量に基づいて、給湯用熱交換器３４から流出する湯水の温度が給湯目標温度になるように、ガス比例弁４０の開度及びミキシング弁４５の開度を調節するフィードフォワード制御を実行し、且つ、給湯温度センサ４４の検出温度と給湯目標温度との偏差に基づいてガス比例弁４０の開度を微調整するフィードバック制御を実行する。
従って、給湯栓４９からは給湯目標温度の湯水が出湯することになる。
【００４５】
例えば、給湯目標温度が４０°Ｃに設定されているときは、循環湯水温度が、給湯目標温度の４０°Ｃよりも設定温度差Δｔ、即ち２°Ｃ低い３８°Ｃ以下のときが、前記燃焼制御用温度となる。そして、混合部Ｋｍにおいて、混合湯水温度が低設定混合温度（例えば３０°Ｃ）になるように、住戸用湯水供給路１１からの湯水に住戸用給水路１５からの水が混合され、加熱部Ｋｈで給湯目標温度の４０°Ｃに加熱されて出湯されることになる。
【００４６】
つまり、給湯器Ｋは、前記循環湯水温度が給湯目標温度よりも設定温度差Δｔ以上低いときは、給湯目標温度よりも設定温度差Δｔ以上低くなるように設定された前記設定混合温度になるように混合部Ｋｍの混合作動を制御し、且つ、給湯温度が前記給湯目標温度になるように加熱部Ｋｈの加熱作動を制御し、前記循環湯水温度が給湯目標温度に対して設定温度差Δｔ低い温度よりも高いときは、加熱部Ｋｈの加熱作動を停止させた状態で、給湯温度が給湯目標温度になるように混合部Ｋｍの混合作動を制御するように構成してある。
【００４７】
給湯用循環手段Ｃ２からの湯水の温度が燃焼制御用温度のときは、給湯目標温度への温度調節が安定して行えるような設定混合温度になるように、給湯用循環手段Ｃ２からの湯水と住戸用給水手段Ｗ３からの水とが混合されてから、加熱部Ｋｈにて給湯目標温度になるように加熱されるので、給湯用循環手段Ｃ２からの湯水の温度と給湯目標温度との差が小さいときでも、給湯目標温度又は略給湯目標温度の湯水が得られる。
つまり、ガスバーナ３７の燃焼安定性を確保するために、ガスバーナ３７の燃焼量は所定の最小燃焼量よりも小さくは絞れないようにしてある。従って、前述の如き湯水混合制御、即ち、給湯用循環手段Ｃ２からの湯水と住戸用給水手段Ｗ３からの水とを設定混合温度になるように混合する制御を行わないときは、給湯用循環手段Ｃ２からの湯水の温度と給湯目標温度との差が小さくて、その差に基づいて求めた燃焼量が最小燃焼量よりも小さいときは、例えば、ガスバーナ３７を最小燃焼量にて燃焼させるようになるので、出湯する湯水の温度を給湯目標温度に調整し難いといった不具合が生じることになる。そこで、前述の如き湯水混合制御を行うことにより、前述の如き不具合が解消されることになる。
【００４８】
次に、運転制御部Ｕについて説明を加える。
運転制御部Ｕは、１日のうちの一部の時間帯として設定される設定発電時間帯においては発電機１及び排熱回収用循環手段Ｃ１を作動させ、その設定発電時間帯以外の非発電時間帯においては発電機１及び排熱回収用循環手段Ｃ１を停止させる形態で、且つ、貯湯槽３の目標貯留量として非発電時間帯において消費又は略消費可能な貯留量が設定されて、設定発電時間帯においては、その目標貯留量を貯留すべく槽用給水手段Ｗ１を作動させ、且つ、設定発電時間帯及び非発電時間帯においては、貯湯槽３に貯留された湯水を消費すべく給湯用循環手段Ｃ２を作動させる形態で運転を制御するように構成してある。
又、運転制御部Ｕは、非発電時間帯において、貯湯槽３の貯留量が設定下限貯留量になると、給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態から前記給水状態に切り換えるように構成してある。
又、運転制御部Ｕは、非発電時間帯において、貯湯槽３の貯留量が設定下限貯留量になると、又は、貯湯槽３の貯留量が設定下限貯留量以下にならなくとも非発電時間帯における設定終期になると、給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態から前記給水状態に切り換え、且つ、貯湯槽３の湯水を、湯水の水質を維持することが可能な水質維持温度にまで加熱するように、補助加熱用給湯器Ｂを加熱作動させる貯湯槽水質維持運転を実行するように構成してある。
又、運転制御部Ｕは、給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態にて運転させるのを停止してから、次に給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態にて運転させるまでの間に、給湯用循環手段Ｃ２を前記水置換状態にて運転させる水置換運転を実行するように構成してある。
【００４９】
運転制御部Ｕに内蔵した記憶部には、前記設定発電時間帯、前記設定下限量に対応する貯湯槽３の水位である設定下限水位、前記水質維持温度、前記貯湯槽水質維持運転を継続して実行する設定水質維持運転時間、前記設定水置換時間、並びに、補助給湯器Ｂにて給湯用循環経路Ｒを通流する湯水を加熱するための目標加熱温度の夫々を予め設定して記憶させてある。
ちなみに、前記設定発電時間帯としては、夏期中間期用と冬期用との２種類を設定して記憶させてあり、夏期中間期用の設定発電時間帯は、電力需要の多い時間帯である１８時から２４時までの時間帯に設定し、冬期用の設定発電時間帯は、熱需要が夏期に比べて多いので、熱需要に対応するように、冬期用の設定発電時間帯よりも長い１４時から２３時までの時間帯に設定してある。尚、設定発電時間帯と非発電時間帯とを加えた時間帯（２４時間）を1サイクルと称する。
【００５０】
前記設定下限貯留量は、小貯留部３ｓにおける満水状態での貯留量に設定してあるので、前記設定下限水位は主貯留部３ｍの水位がゼロとなる水位に設定してある。即ち、貯湯槽３の水位が前記設定下限水位の時は、湯水の全量が小貯留部３ｓに貯留され、主貯留部３ｍには貯留されない状態にすることが可能となる。
【００５１】
前記水質維持温度は、例えば６０°Ｃに設定し、前記設定水質維持運転時間は例えば１時間に設定してある。
前記設定水置換時間は、給水切換三方弁Ｖ４を前記給水路接続状態に切り換えた時に給湯用循環経路Ｒに流入した受水槽５の水が、給湯用循環経路Ｒを流れて、貯湯槽３に対して流出するまでに要する時間以上に設定してある。
【００５２】
前記目標加熱温度は、各住戸Ｈに設けられた給湯器Ｋのリモコン操作部３１にて設定可能な通常給湯目標温度の設定範囲（例えば３７〜４４°Ｃ）外の温度に設定してある。
そして、前記目標加熱温度は、前記通常給湯目標温度設定範囲よりも低く且つ前記低設定混合温度と同温度（例えば３０°Ｃ）に設定されて、冬期（例えば、１２〜２月）に用いられる冬期用目標加熱温度と、前記通常給湯目標温度設定範囲よりも高い温度（例えば４５°Ｃ）に設定されて、冬期以外の時期に用いられる夏期中間期用目標加熱温度とを記憶させてある。
【００５３】
又、給湯用循環手段Ｃ２にて集合住宅に含まれる複数の住戸Ｈに供給した湯水の熱量を熱負荷として検出する熱負荷検出手段を設けると共に、その熱負荷検出手段にて検出される前記非発電時間帯における熱負荷（以下、単に非発電時間帯熱負荷と称する場合がある）を前記記憶部に記憶するように構成してあり、運転制御手段Ｕは、前記記憶部に記憶されている非発電時間帯熱負荷の記憶情報に基づいて、運転対象サイクルの前記目標貯留量を設定するように構成してある。
【００５４】
具体的には、運転制御手段Ｕは、各住戸別給湯量センサＱ３及び住戸供給温度センサＴ４夫々の検出情報に基づいて、前記非発電時間帯を通じて、各住戸別給湯量センサＱ３の検出流量を合計した合計湯水流量に住戸供給温度センサＴ４の検出温度を乗じて熱量を演算すると共に、その熱量を積算し、その積算した総熱量を、前記非発電時間帯熱負荷として求め、前記記憶手段に記憶されている前記非発電時間帯熱負荷の記憶情報を新たに求めた前記非発電時間帯熱負荷熱に書き換えるように構成してある。つまり、前記熱負荷検出手段は、住戸別給湯量センサＱ３と住戸供給温度センサＴ４とから構成してある。
そして、運転制御手段Ｕは、前記記憶手段に記憶されている前記非発電時間帯熱負荷、即ち、運転対象サイクルの前のサイクルにおける前記非発電時間帯熱負荷に基づいて、運転対象サイクルの前記目標貯留量を設定するように構成してある。
【００５５】
以下、運転制御部Ｕの制御動作を、共用部及び各住戸Ｈに給電する給電制御と、各住戸に給湯する給湯制御とに分けて説明を加える。
先ず、給電制御の制御動作について説明を加える。
運転制御部Ｕは、前記設定発電時間帯においては、発電機１及び冷却水循環ポンプＰ１を運転し、その設定発電時間帯以外の非発電時間帯においては、発電機１及び冷却水循環ポンプＰ１を停止させる形態で、発電機１を毎日自動運転する。
そして、発電機１の運転中は、共用部の電力消費機器や各住戸Ｈの電力消費機器に対して発電機１にて給電されると共に、それらの電力消費機器に対して発電機１の出力が不足する場合には、その不足分が商用電源６１にて補われる。
又、発電機１の停止中は、共用部の電力消費機器や各住戸Ｈの電力消費機器に対して、商用電源６１にて給電される。
又、発電機１の運転中は、エンジン冷却水が排熱回収用熱交換器２及び補助加熱用熱交換器６を通って循環して、ガスエンジンが冷却される共に、その排熱が、排熱回収用熱交換器２及び補助加熱用熱交換器６に供給されることになる。
【００５６】
次に、給湯制御について、図１ないし図５に基づいて説明する。尚、図１ないし図５において、湯水やエンジン冷却水が流れる状態となっている各流路部分を太線にて示す。
尚、住戸用給水路１５を通じて、常時、各住戸Ｈに受水槽５の水が給水可能なように、循環兼住戸用給水ポンプＰ６は常時作動させているので、以下の説明では、循環兼住戸用給水ポンプＰ６の作動制御の説明は省略する。
【００５７】
前記設定発電時間帯の開始に伴い、排熱回収用循環手段Ｃ１を作動させ、且つ、目標貯留量を貯留すべく槽用給水手段Ｗ１を作動させ、且つ、給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態にて作動させる通常貯湯槽湯水循環運転を実行する。
つまり、槽湯水循環切換三方弁Ｖ２を前記通常循環状態に切り換え且つ貯湯槽側槽昇温切換三方弁Ｖ６を前記排熱回収状態に切り換えた状態で、排熱回収用循環ポンプＰ３を作動させることにより、排熱回収用循環手段Ｃ１を作動させ、並びに、給水切換三方弁Ｖ４を前記給水路遮断状態に切り換え且つ槽戻し停止三方弁Ｖ３を前記槽戻し停止状態に切り換えた状態で、上流側循環ポンプＰ４及び下流側循環ポンプＰ５を作動させることにより、給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態にて作動させ、並びに、水位センサＬの検出情報に基づいて、貯湯槽３の貯留量が目標貯留量になるように、槽用給水ポンプＰ２を作動させることにより、貯湯槽３に目標貯留量を貯留すべく槽用給水手段Ｗ１を作動させる。
【００５８】
図１に示すように、通常貯湯槽湯水循環運転においては、エンジン冷却水は排熱回収用熱交換器２及び補助加熱用熱交換器６を通って循環し、貯湯槽３の湯水は、排熱回収用循環経路１０にて排熱回収用熱交換器２を通って循環し、並びに、給湯用循環経路Ｒにて複数の住戸Ｈを巡って循環し、貯湯槽３の貯留量が目標貯留量に維持されるように、槽用給水路９を通じて貯湯槽３に給水される。
つまり、貯湯槽３の小貯留部３ｓから取り出された湯水が排熱回収用熱交換器２におけるエンジン冷却水との熱交換作用にて加熱されて主貯留部３ｍに戻されることにより、貯湯槽３の湯水が加熱され、その貯湯槽３の湯水が、複数の住戸Ｈを経由し、且つ、補助加熱用熱交換器６にてエンジン冷却水との熱交換作用にて加熱される状態で給湯用循環経路Ｒを通じて循環する。
【００５９】
又、通常貯湯槽湯水循環運転中は、以下のように、補助加熱制御を実行する。
即ち、貯湯槽取り出し温度センサＴ３の検出温度が目標加熱温度以上のときは、補助加熱切換三方弁Ｖ５を前記補助加熱停止状態に切り換える。又、貯湯槽取り出し温度センサＴ３の検出温度が目標加熱温度よりも低いときは、補助加熱切換三方弁Ｖ５を前記補助加熱状態に切り換え且つ給湯器側槽昇温切換三方弁Ｖ７を前記補助加熱状態に切り換える。すると、補助給湯器Ｂの第１熱交換器に湯水が通流して、第１給水量センサＱ１の検出流量が設定量以上になるので、それに基づいて、上述のようにガスバーナ７３を点火させると共に、第１熱交換器７１からの出湯温度が加熱目標温度になるように、燃焼量制御を実行する。即ち、燃焼量制御では、加熱目標温度、貯湯槽取り出し温度センサＴ３の検出温度及び第１給水量センサＱ１の検出給水量に基づいて、第１熱交換器７１から流出する湯水の温度が加熱目標温度になるように、ガス比例弁７６の開度を調節するフィードフォワード制御を実行し、並びに、第１出湯温度センサＴ１の検出温度と加熱目標温度との偏差に基づいてガス比例弁７６の開度を微調整するフィードバック制御を実行する。
【００６０】
各住戸Ｈにおいては、以下のように、給湯用循環経路Ｒを流れる湯水を用いて給湯器Ｋにより給湯することになる。
即ち、夏期及び中間期は、加熱目標温度が通常給湯目標温度設定範囲よりも高い夏期中間期用目標加熱温度に設定されるので、補助給湯器Ｂにより補助加熱する、しないに係わらず、給湯用循環経路Ｒの住戸経由箇所を通常給湯目標温度設定範囲よりも高い温度の湯水が流れることになるので、各住戸Ｈにおいては、給湯目標温度が通常給湯目標温度設定範囲に設定されているときは、給湯器Ｋによって、ガスバーナ３７が燃焼停止状態で、混合部Ｋｍによる混合により給湯目標温度の湯が給湯されることになる。従って、各住戸の給湯器Ｋにおいては、前記設定混合温度になるように一旦水を混合してから、給湯温度が給湯目標温度になるように加熱する形態での運転（以下、水混合後加熱運転と称する場合がある）を起こさせないようにすることができるので、省エネを図ることができる。
冬期は、加熱目標温度が通常給湯目標温度設定範囲よりも低くて前記低設定混合温度と同じである冬期目標加熱温度に設定される。冬期は、通常は、発電機１の排熱による加熱だけでは、貯湯槽３の湯水を冬期目標加熱温度以上に加熱することができない場合が多いので、給湯用循環経路Ｒの住戸経由箇所を前記低設定混合温度の湯水が流れることが多くなるので、各住戸Ｈにおいては、給湯目標温度が通常給湯目標温度設定範囲に設定されているときは、給湯器Ｋによって、主として、混合部Ｋｍにより水が混合されること無く、ガスバーナ３７による加熱により給湯目標温度の湯が給湯されることになる。従って、各住戸の給湯器Ｋにおいては、前記水混合後加熱運転を極力起こさせないようにすることができるので、省エネを図ることができる。
【００６１】
前記設定発電時間帯が終了して、非発電時間帯が始まると、排熱回収用循環手段Ｃ１及び槽用給水手段Ｗ１を停止させ、且つ、給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態にて作動させる水補給停止貯湯槽湯水循環運転を実行する。
【００６２】
つまり、上述の通常貯湯槽湯水循環運転の制御状態から、排熱回収用循環ポンプＰ３を停止させることにより、排熱回収用循環手段Ｃ１を停止させ、並びに、槽用給水ポンプＰ２を停止させることにより、槽用給水手段Ｗ１を停止させるが、給湯用循環手段Ｃ２は継続して前記貯湯槽湯水循環状態にて作動させる。
【００６３】
図２に示すように、水補給停止貯湯槽湯水循環運転においては、エンジン冷却水の循環が停止し、排熱回収用循環経路１０を通じての貯湯槽３の湯水の循環が停止して、発電機１の排熱による貯湯槽３の湯水の加熱が停止され、且つ、受水槽５からの貯湯槽３への水の補給が停止された状態で、貯湯槽３の湯水が給湯用循環経路Ｒにて複数の住戸Ｈを巡って循環する。
【００６４】
水補給停止貯湯槽湯水循環運転中も、上述の補助加熱制御を実行する。
水補給停止貯湯槽湯水循環運転中に、給湯用循環経路Ｒの住戸経由箇所を流れる湯水の温度の状態は、上述の通常貯湯槽湯水循環運転中と同様であるので、各住戸Ｈにおいては、上述の通常貯湯槽湯水循環運転中と同様に、給湯用循環経路Ｒを流れる湯水を用いて給湯器Ｋにより給湯することになるので、説明を省略する。
【００６５】
非発電時間帯中に、次の設定発電時間帯の開始時間に対して、前記設定水質維持運転時間と前記設定水置換時間とを加えた水質維持所要時間以上前の時間に、水位センサＬの検出水位が前記設定下限水位になり、主貯留部３ｍの貯留量がゼロとなって、全量が小貯留部３ｓに貯留される状態、即ち、貯湯槽３の貯留量が設定下限貯留量になると、排熱回収用循環手段Ｃ１及び槽用給水手段Ｗ１の停止状態を維持した状態で、給湯用循環手段Ｃ２を前記給水状態にて作動させて、給水状態運転を実行する。
【００６６】
つまり、上述の水補給停止貯湯槽湯水循環運転の制御状態から、上流側循環ポンプＰ４及び下流側循環ポンプＰ５を停止させ、且つ、給水切換三方弁Ｖ４を前記給水路接続状態に切り換えることにより、給湯用循環手段Ｃ２を給水状態にて作動させる。
【００６７】
図３に示すように、給水状態運転においては、排熱回収用循環経路１０及び給湯用循環経路Ｒを通じての貯湯槽３の湯水の循環が停止し、且つ、受水槽５からの貯湯槽３への水の補給が停止された状態で、受水槽５の水が給水切換三方弁Ｖ４を通じて給湯用循環経路Ｒに供給される。
【００６８】
給水状態運転中も、上述の補助加熱制御を実行する。
給水状態運転中に、給湯用循環経路Ｒの住戸経由箇所を流れる湯水の温度の状態は、上述の通常貯湯槽湯水循環運転中と同様であるので、各住戸Ｈにおいては、上述の通常貯湯槽湯水循環運転中と同様に、給湯用循環経路Ｒを流れる湯水を用いて給湯器Ｋにより給湯することになるので、説明を省略する。
【００６９】
非発電時間帯中に、給水状態運転を実行しているとき及び実行していないときにかかわらず、次の設定発電時間帯の開始時間よりも水質維持所要時間前の時間、即ち、非発電時間帯の設定終期になると、排熱回収用循環手段Ｃ１及び槽用給水手段Ｗ１の停止状態を維持し、且つ、給湯用循環手段Ｃ２を前記給水状態に作動させる状態を維持した状態で、貯湯槽３の湯水を、湯水の水質を維持することが可能な水質維持温度にまで加熱するように、補助加熱用給湯器Ｂを加熱作動させる貯湯槽水質維持運転を前記設定水質維持運転時間の間実行する。
【００７０】
つまり、給水状態運転を実行しているときは、給水状態運転の制御状態から、補助加熱切換三方弁Ｖ５を前記補助加熱停止状態に切り換え、槽湯水循環切換三方弁Ｖ２を前記槽昇温状態に切り換え、貯湯槽側槽昇温切換三方弁Ｖ６及び給湯器側槽昇温切換三方弁Ｖ７を夫々前記槽昇温状態に切り換え、並びに、排熱回収用循環ポンプＰ３及び槽昇温用ポンプＰ７を作動させ、給水状態運転を実行していないときは、上述の水補給停止貯湯槽湯水循環運転の制御状態から、上流側循環ポンプＰ４及び下流側循環ポンプＰ５を停止させ、且つ、給水切換三方弁Ｖ４を前記給水路接続状態に切り換え、更に、補助加熱切換三方弁Ｖ５を前記補助加熱停止状態に切り換え、槽湯水循環切換三方弁Ｖ２を前記槽昇温状態に切り換え、貯湯槽側槽昇温切換三方弁Ｖ６及び給湯器側槽昇温切換三方弁Ｖ７を夫々前記槽昇温状態に切り換え、並びに、排熱回収用循環ポンプＰ３及び槽昇温用ポンプＰ７を作動させる。
【００７１】
図４に示すように、貯湯槽水質維持運転においては、受水槽５からの貯湯槽３への水の補給が停止され、又、給湯用循環経路Ｒ内の湯水の貯湯槽３に対する流出が阻止された状態で、受水槽５の水が給水切換三方弁Ｖ４を通じて給湯用循環経路Ｒに供給されて、補助給湯器Ｂを通過することなく給湯用循環経路Ｒを流れ、並びに、貯湯槽３の小貯留部３ｓの湯水が、補助給湯器Ｂの第１熱交換器７１及び第２熱交換器７２の両方に通流されて加熱された後、分岐流路１０ｂを通じて小貯留部３ｓに戻されるように循環される。各住戸Ｈにおいては、給湯用循環経路Ｒを流れる受水槽５の水を用いて、給湯器Ｋにて給湯することになる。
又、貯湯槽水質維持運転の実行中は、水質維持温度、小貯留部取り出し温度センサＴ５の検出温度及び第１給水量センサＱ１の検出給水量に基づいて、第１熱交換器７１から流出する湯水の温度が水質維持温度になるように、ガス比例弁７６の開度を調節するフィードフォワード制御を実行し、並びに、第１出湯温度センサＴ１の検出温度と水質維持温度との偏差に基づいてガス比例弁７６の開度を微調整するフィードバック制御を実行する。
貯湯槽水質維持運転により、小貯留部３ｓの湯水が水質維持温度に加熱され、しかも、小貯留部３ｓの湯水を第１熱交換器７１及び第２熱交換器７２の両方で加熱することから、貯湯槽水質維持運転の運転時間を短縮することが可能となる。
【００７２】
貯湯槽水質維持運転が終了すると、給湯用循環手段Ｃ２を前記水置換状態にて運転する水置換運転を実行する。
つまり、貯湯槽水質維持運転の制御状態から、排熱回収用循環ポンプＰ３及び槽昇温用ポンプＰ７を停止させて、補助給湯器Ｂによる小貯留３ｓの湯水の加熱を停止し、槽戻し停止三方弁Ｖ３を前記槽戻し状態に切り換え、その状態を、前記設定水置換時間の間継続する。
【００７３】
図５に示すように、水置換運転では、受水槽５の水が給水切換三方弁Ｖ４を通じて給湯用循環経路Ｒに供給されて、補助給湯器Ｂを通過することなく給湯用循環経路Ｒを流れて、主貯留部３ｍに流出して、給湯用循環経路Ｒ内の湯水が、給湯用循環経路Ｒの略全長にわたって、受水槽５の水道水にて置換されて、給湯用循環経路Ｒ内の湯水の水質が維持されることになる。しかも、給湯用循環経路Ｒ内の湯水を受水槽５の水道水にて置換するので、水道水に含まれる塩素の殺菌作用により、給湯用循環経路Ｒ内の湯水の水質が一層向上する。
そして、水置換運転が終了して、次の設定発電時間帯が開始するのに伴って、通常貯湯槽湯水循環運転を実行する。
【００７４】
又、運転制御部Ｕは、非発電時間帯の間は、各住戸別給湯量センサＱ３及び住戸供給温度センサＴ４夫々の検出情報に基づいて、前述のようにして、前記非発電時間帯熱負荷を求め、前記記憶手段に記憶されている前記非発電時間帯熱負荷の記憶情報を新たに求めた前記非発電時間帯熱負荷熱に書き換える。運転制御部Ｕは、このように書き換えた前記非発電時間帯熱負荷と前記加熱目標温度とに基づいて、運転対象サイクルの目標貯留量を求める。
【００７５】
又、図示を省略するが、運転制御部Ｕに各種の運転指令を指令する操作盤には、メンテナンス用運転の実行を人為的に指令するメンテナンス用運転指令部を設けてある。
運転制御部Ｕは、メンテナンス用運転が指令されると、排熱回収用循環手段Ｃ１及び槽用給水手段Ｗ１を停止し、且つ、給湯用循環手段Ｃ２を前記給水状態にて作動させるメンテナンス用運転を実行する。
このメンテナンス用運転の制御動作は、上述の給水状態運転と同様であり、受水槽５からの水の流動状態も、上述の給水状態運転と同様であるので、それらの説明を省略する。
このメンテナンス用運転は、発電機３から排熱を供給できない発電機３の故障時又はメンテナンス時や、貯湯槽３に湯水を貯留できない貯湯槽３のメンテナンス時に行うものであり、発電機３の故障時又はメンテナンス時や、あるいは、貯湯槽３のメンテナンス時にも、各住戸Ｈに給湯用循環経路Ｒを通じて給湯することが可能となる。
【００７６】
次に、上述のように構成したコージェネレーションシステムの時間経過に伴う運転パターンを説明する。
図７は冬期における運転パターンの一例を示し、図８は夏期における運転パターンの一例を示す。冬期においては１４時から２３時まで、夏期において１８時から２４時までの設定発電時間帯は、発電機１を運転すると共に、通常貯湯槽湯水循環運転を実行する。尚、図７及び図８においては、発電機１の運転状態を、発電機１から排熱が発生していることにより示している。この通常貯湯槽湯水循環運転の実行中は、貯湯槽３の貯留量が目標貯留量に維持され、貯湯槽３の湯水の温度は成り行きとなり、給湯用循環経路Ｒを流れる湯水の温度が目標加熱温度よりも低くなると、補助給湯器Ｂにて目標加熱温度になるように加熱される。
設定発電時間帯が終了するのに伴って、発電機１を停止すると共に、水補給停止貯湯槽湯水循環運転を実行し、この水補給停止貯湯槽湯水循環運転の実行中に、図７に示すように、次の設定発電時間帯の開始時間に対して水質維持所要時間以上前の時間に、貯湯槽３の貯留量が設定下限貯留量以下になると、給水状態運転を実行する。この水補給停止貯湯槽湯水循環運転及び給水状態運転の実行中は、給湯用循環経路Ｒを流れる湯水の温度が目標加熱温度よりも低くなると、補助給湯器Ｂにて目標加熱温度になるように加熱される。図８では、次の設定発電時間帯の開始時間よりも水質維持所要時間前になるまで、貯湯槽３の貯留量が設定下限貯留量よりも多い状態に維持されて、給水状態運転が実行されない運転パターンを示す、
続いて、次の設定発電時間帯の開始時間よりも水質維持所要時間前の時間になると、貯湯槽水質維持運転を実行する。その貯湯槽水質維持運転により、貯湯槽３の湯水が水質維持温度にまで加熱される。
続いて、貯湯槽水質維持運転が終了すると、水置換運転を実行する。この水置換運転により、給湯用循環経路Ｒの湯水が、その略全長にわたって、受水槽５の水と置換される。
【００７７】
以下、本発明の第２及び第３の各実施形態を説明するが、第１実施形態と同じ構成要素や同じ作用を有する構成要素については、重複説明を避けるために、同じ符号を付すことにより説明を省略し、主として、第１実施形態と異なる構成を説明する。
【００７８】
〔第２実施形態〕
以下、第２実施形態を説明する。
図９に示すように、第２実施形態においては、コージェネレーションシステムの構成は、上記の第１実施形態と同様であり、運転制御部Ｕの制御動作は、第１実施形態における水置換運転に代えて、給湯用循環経路Ｒ内の湯水を、湯水の水質を維持することが可能な水質維持温度にまで加熱するように、補助給湯器Ｂを加熱作動させる循環経路水質維持運転を実行する点で異なる以外は、第１実施形態と同様である。
【００７９】
即ち、循環経路水質維持運転では、貯湯槽水質維持運転に引き続いて、給湯用循環経路Ｒを通流する湯水を補助給湯器Ｂにて水質維持温度に加熱する状態で、給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態にて運転する。
つまり、貯湯槽水質維持運転の制御状態から、排熱回収用循環ポンプＰ３及び槽昇温用ポンプＰ７を停止させて、補助給湯器Ｂによる小貯留３ｓの湯水の加熱を停止し、給水切換三方弁Ｖ４を前記給水路遮断状態に切り換え、補助加熱切換三方弁Ｖ５及び給湯器側槽昇温切換三方弁Ｖ７をそれぞれ前記補助加熱状態に切り換え、槽戻し停止三方弁Ｖ３を前記槽戻し状態に切り換え、その状態を、前記設定水置換時間の間継続する。
又、水質維持温度、貯湯槽取り出し温度センサＴ３の検出温度及び第１給水量センサＱ１の検出給水量に基づいて、第１熱交換器７１から流出する湯水の温度が水質維持温度になるように、ガス比例弁７６の開度を調節するフィードフォワード制御を実行し、並びに、第１出湯温度センサＴ１の検出温度と水質維持温度との偏差に基づいてガス比例弁７６の開度を微調整するフィードバック制御を実行する。
【００８０】
図９に示すように、循環経路水質維持運転においては、受水槽５からの貯湯槽３への水の補給が停止された状態で、小貯留部３ｓから取り出された湯水が、補助給湯器Ｂにて水質維持温度に加熱される状態で、給湯用循環経路Ｒを通流して、主貯留部３ｍに戻されることにより、給湯用循環経路Ｒの略全長にわたって水質維持温度の湯が通流することになる。
この循環経路水質維持運転は、貯湯槽水質維持運転の後に実行されることにより、貯湯槽水質維持運転の後であって略水質維持温度になっている湯を補助給湯器Ｂにて水質維持温度に加熱する形態で行うので、消費エネルギーを低減することが可能となる。
この貯湯槽水質維持運転の運転時間は短時間であるので、各住戸Ｈにおいて、給湯用循環経路Ｒを通流する湯が使用されても、湯の循環に支障を与える程度にまで小貯留部３ｓの貯留量が少なくなることはない。
【００８１】
〔第３実施形態〕
以下、第３実施形態を説明する。
図１０に示すように、第３実施形態においては、コージェネレーションシステムの構成は、貯湯槽３及び排熱回収用循環手段Ｃ１の構成が異なる以外は、上記の第１実施形態と同様である。
即ち、第１実施形態と同様に、貯湯槽３は、主貯留部３ｍとその主貯留部３ｍよりも横断面積が小さい小貯留部３ｓとを備えて構成してあるが、主貯留部３ｍ及び小貯留部３ｓの具体的な構成が第１実施形態と異なる。
貯湯槽３は、上部が開口した概ね直方体形の箱状の槽形成部材にて開放型に構成し、その槽形成部材の底部の一部分を窪ませて凹部を形成して、その凹部にて小貯留部３ｓを形成し、槽形成部材内における凹部以外の部分を主貯留部３ｍとするようにしてある。
水位センサＬは、主貯留部３ｍから小貯留部３ｓにわたって水位を計測するように設け、槽経由循環路４は、小貯留部３ｓの底部から湯水を取り出して、小貯留部３ｓの上方に対応する主貯留部３ｍの上部に戻すように設けてある。
【００８２】
排熱回収用循環手段Ｃ１は、第１実施形態において設けた分岐経路１０ｂ及び槽湯水循環切換三方弁Ｖ２を省略して、貯湯槽３の小貯留部３ｓの底部から取り出した湯水を排熱回収用熱交換器２を経由して主貯留部３ｍの上部から戻すように流すべく配管した排熱回収用循環経路１０と、その排熱回収用循環経路１０に設けた排熱回収用循環ポンプＰ３とを備えて構成してある。
【００８３】
次に、運転制御部Ｕの制御動作について説明する。
給電制御は第１実施形態と同様であるので説明を省略する。
給湯制御においては、通常貯湯槽湯水循環運転、水補給停止貯湯槽湯水循環運転、給水状態運転、貯湯槽水質維持運転及び水置換運転を、第１実施形態と同様に自動的に実行し、又、操作盤のメンテナンス用運転指令部からの指令に基づいてメンテナンス用運転を実行する。各運転における制御動作は、槽湯水循環切換三方弁Ｖ２の制御動作がない点で異なる以外は、第１実施形態と同様であるので、説明を省略する。
又、各運転におけるエンジン冷却水、貯湯槽３の湯水及び受水槽５の水の流動形態は、貯湯槽水質維持運転における流動形態が異なる以外は第１実施形態と同様であるので、以下、貯湯槽水質維持運転の流動形態における第１実施形態と異なる点を説明して、その他の運転の流動形態の説明は省略する。
即ち、第１実施形態では、貯湯槽３の小貯留部３ｓの湯水が補助給湯器Ｂにて加熱された後、排熱回収用循環経路１０の分岐経路１０ｂを通じて直接小貯留部３ｓに戻されるのに対して、第３実施形態では、貯湯槽３の小貯留部３ｓの湯水が補助給湯器Ｂにて加熱された後、排熱回収用循環経路１０を通じて主貯留部３ｍの上部から小貯留部３ｓに戻される点で、第３実施形態における貯湯槽水質維持運転の流動形態が第１実施形態と異なる。
【００８４】
〔別実施形態〕
次に別実施形態を説明する。
上記の実施形態においては、熱負荷検出手段として、非発電時間帯中に給湯用循環手段Ｃ２を通じて複数の住戸Ｈに供給される湯水の総熱量を前記非発電時間帯熱負荷として求めるように構成する場合について例示したが、非発電時間帯中に給湯用循環手段Ｃ２を通じて複数の住戸Ｈに供給される湯水の総流量を前記非発電時間帯熱負荷として求めるように構成しても良い。この場合、前記非発電時間帯熱負荷として求めた運転対象サイクルの前のサイクルにおける湯水の総流量を、運転対象サイクルの目標貯留量として設定することになる。
熱負荷検出手段にて検出される前記非発電時間帯熱負荷に基づいて、運転対象サイクルの目標貯留量を設定するに当たって、具体的な設定方法は変更可能である。例えば、毎日検出した前記非発電時間帯熱負荷を月毎に平均して、その平均値を月に対応付けて前記記憶部に記憶させ、その記憶情報に基づいて、運転対象サイクルの目標貯留量を設定するようにしても良い。
【００８５】
上記の実施形態においては、運転対象サイクルの目標貯留量を、熱負荷検出手段にて検出される前記非発電時間帯熱負荷に基づいて変更設定する場合について例示したが、コージェネレーションシステムを設置する対象の地域又は集合住宅の熱負荷を鑑みて、前記目標貯留量を、月に対応付けて、あるいは、月及び曜日に対応付けて予め設定して前記記憶部に記憶させ、その記憶情報に基づいて、運転対象サイクルの前記目標貯留量を、月毎に、あるいは、曜日毎に固定的に設定するようにしても良い。
【００８６】
上記の実施形態においては、給湯用循環経路Ｒは、槽経由循環路４及び槽バイパス路１２を用いて、貯湯槽３を迂回する状態で複数の住戸Ｈを経由する貯湯槽迂回経路を形成するように構成したが、これに代えて、給湯用循環経路Ｒは、槽経由循環路４のみを用いて、貯湯槽３の小貯留部３ｓから取り出した湯水を集合住宅に含まれる複数の住戸Ｈを経由して主貯湯部３ｍの上部に戻す経路を形成するように構成しても良い。
【００８７】
上記の実施形態においては、貯湯槽３を、主貯留部３ｍとその主貯留部３ｍよりも横断面積が小さい小貯留部３ｓとを備えて構成する場合について例示したが、単に一つの貯留部を備えるように構成しても良い。
【００８８】
上記の実施形態においては、貯湯槽用補助加熱手段Ｂ１と循環経路用補助加熱手段Ｂ２とを兼用する補助給湯器Ｂを設ける場合について例示したが、湯槽用補助加熱手段Ｂ１と循環経路用補助加熱手段Ｂ２とを別個に設けても良い。
この場合、貯湯槽水質維持運転の実行中に、給湯用循環経路Ｒを通流する湯水を循環経路用補助加熱手段Ｂ２にて目標加熱温度に加熱しながら給水状態運転を並行して実行することが可能となるので、貯湯槽水質維持運転の実行中にも、目標加熱温度の湯を各住戸Ｈに供給することが可能となる。
又、それら湯槽用補助加熱手段Ｂ１と循環経路用補助加熱手段Ｂ２とを省略しても良い。但し、湯槽用補助加熱手段Ｂ１と循環経路用補助加熱手段Ｂ２とを省略する場合は、貯湯槽水質維持運転及び循環経路水質維持運転を実行することができない。
【００８９】
各住戸Ｈに設ける給湯器Ｋの構成は変更可能である。例えば、前記循環湯水温度が給湯目標温度よりも低いときは、給湯目標温度よりも設定温度差以上低くなるように設定された前記設定混合温度になるように混合部Ｋｍの混合作動を制御し、且つ、給湯温度が前記給湯目標温度になるように加熱部Ｋｈの加熱作動を制御し、前記循環湯水温度が給湯目標温度以上のときは、加熱部Ｋｈの加熱作動を停止させた状態で、給湯温度が給湯目標温度になるように混合部Ｋｍの混合作動を制御するように構成しても良い。
【００９０】
上記の実施形態においては、給水源として受水槽５を用いる場合について例示したが、給水源として水道そのものを用いても良い。この場合は、槽用給水路９及び循環給水路１４夫々に水道管を接続することになる。
【００９１】
上記の第３実施形態において、第２実施形態と同様に、水置換運転に代えて、循環経路水質維持運転を実行するように構成しても良い。
【００９２】
上記の実施形態のように、発電手段を、ガスエンジン等のエンジンにて駆動されるエンジン駆動の回転式の発電機１にて構成する場合、排熱回収用熱交換器２に供給する発電機１の排熱としては、上記の実施形態において例示したエンジン冷却水以外に、エンジンの排ガスを供給したり、エンジン冷却水と排ガスの両方を供給したりするように構成しても良い。尚、発電手段を、エンジン駆動の回転式の発電機１にて構成する場合、エンジンとしては、上記の実施形態において例示した都市ガスを燃料とするもの以外に、ＬＰガス、石油、ガソリン等種々の燃料を用いるものを使用することができる。
又、発電手段は、上記の実施形態において例示した如きエンジン駆動の回転式の発電機１にて構成する以外に、ガスタービンにて駆動するガスタービン駆動の回転式発電機にて構成しても良い。発電手段をガスタービン駆動の回転式の発電機にて構成する場合、排熱回収用熱交換器２には排熱としてガスタービンの排ガスを供給するように構成する。
又、発電手段としては、上記の如き回転式の発電機に限定されるのではなく、例えば、各種の燃料電池にて構成することができる。発電手段を燃料電池にて構成する場合は、排熱回収用熱交換器２には排熱として燃料電池の冷却水を供給するように構成する。
【図面の簡単な説明】
【図１】第１実施形態に係るコージェネレーションシステムの構成、及び、通常貯湯槽湯水循環運転での湯水流動形態を示す図
【図２】第１実施形態に係るコージェネレーションシステムの水補給停止貯湯槽湯水循環運転での湯水流動形態を示す図
【図３】第１実施形態に係るコージェネレーションシステムの給水状態運転及びメンテナンス用運転での湯水流動形態を示す図
【図４】第１実施形態に係るコージェネレーションシステムの貯湯槽水質維持運転での湯水流動形態を示す図
【図５】第１実施形態に係るコージェネレーションシステムの水置換運転での湯水流動形態を示す図
【図６】実施形態に係るコージェネレーションシステムの給湯器の構成を示す図
【図７】第１実施形態に係るコージェネレーションシステムの運転パターンを示す図
【図８】第１実施形態に係るコージェネレーションシステムの運転パターンを示す図
【図９】第２実施形態に係るコージェネレーションシステムの構成、及び、循環経路水質維持運転での湯水流動形態を示す図
【図１０】第３実施形態に係るコージェネレーションシステムの構成を示す図
【図１１】従来のコージェネレーションシステムの構成を示す図
【符号の説明】
１発電手段
２排熱回収用熱交換器
３貯湯槽
３ｍ主貯留部
３ｓ小貯留部
５給水源
Ｂ１貯湯槽用補助加熱手段
Ｂ２循環経路用補助加熱手段
Ｃ１排熱回収用循環手段
Ｃ２給湯用循環手段
Ｈ住戸
Ｋ給湯器
Ｒ給湯用循環経路
Ｕ運転制御手段
Ｗ１槽用給水手段
Ｗ２循環用給水手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power generation means for generating electricity for an area or an apartment house as an electric power supply target, an exhaust heat recovery heat exchanger to which exhaust heat from the power generation means is supplied, and a plurality of dwelling units included in the area or an apartment house Hot water storage tank for storing hot water as a target, tank water supply means for supplying water to the hot water storage tank, waste heat recovery circulating means for circulating hot water between the heat exchanger for exhaust heat recovery and the hot water storage tank, the hot water storage tank and the hot water storage tank The present invention relates to a hot water supply circulation means for circulating hot water in a hot water supply circulation path extending across a plurality of dwelling units, and a cogeneration system provided with an operation control means for controlling operation.
[0002]
[Prior art]
Such a cogeneration system normally operates the power generation means and the exhaust heat recovery circulation means in the set power generation time zone set as a part of the day by the operation control means, and the set power generation In a non-power generation time zone other than the time zone, the power generation means and the exhaust heat recovery circulation means are stopped, and in the set power generation time zone and the non-power generation time zone, the hot water stored in the hot water tank should be consumed. The operation is controlled in such a way that the hot water circulation means is operated, and the hot water in the hot water tank is heated by the exhaust heat generated from the power generation means during the operation of the power generation means, and the hot water in the hot water tank is circulated for hot water supply. It is made to circulate through a path | route, and in each dwelling unit, it can supply hot water to a bath, a kitchen, etc. using the hot water circulating through the circulation path for hot water supply.
In general, the set power generation time zone is set in a time zone in which there is a large demand for power as a whole of the plurality of dwelling units included in the area or the apartment house, for example, a time zone from 18:00 to 24:00. Since the time zone with high demand overlaps with the time zone with high demand for hot water supply, hot water heated by the exhaust heat of the power generation means can be supplied to each dwelling unit during the time zone with high demand for hot water supply.
[0003]
In such a cogeneration system, conventionally, for example, as shown in FIG. 11, the hot water storage tank 3 is configured in a sealed manner, and the water supply means W 1 for the tank supplies water from the water supply to the bottom of the hot water storage tank 3. What is comprised by 81 and comprised so that hot water may be always stored in the hot water storage tank 3 in the full water state is disclosed (for example, refer patent document 1).
In the conventional cogeneration system, as shown in FIG. 11, the exhaust heat recovery circulation means C 1 forms an exhaust heat recovery flow path 82 that forms a circulation path between the hot water storage tank 3 and the exhaust heat recovery heat exchanger 2. And a waste heat recovery circulation pump 83 provided in the exhaust heat recovery flow path 82. The hot water supply circulation means C2 includes a hot water supply circulation path 84 extending between the hot water storage tank 3 and a plurality of dwelling units, and the hot water supply thereof. And a hot water supply circulation pump 85 provided in the circulation path 84. In addition, in FIG. 11, K is a water heater provided in each dwelling unit in order to heat the hot water supplied in the hot water supply circulation means C2.
In the conventional cogeneration system, the power generation means and the exhaust heat recovery circulation means are operated during the set power generation time period, and the power generation means and the exhaust heat recovery circulation means are stopped during the non-power generation time period. Then, in both the set power generation time zone and the non-power generation time zone, water is supplied by the tank water supply means so that the hot water storage tank becomes full.
That is, the hot water storage tank is filled with water in an amount equivalent to the amount of hot water supplied from the hot water tank to each dwelling unit over the set power generation time zone and the non-power generation time zone. Hot water was stored.
[0004]
[Patent Document 1]
JP-A-7-324809
[0005]
[Problems to be solved by the invention]
As described above, in each dwelling unit, hot water circulating in the hot water supply circulation path is used to supply hot water to a bath, kitchen, etc., but in each dwelling unit, reheating is not necessary and the temperature is as high as possible (for example, 40 ° C). When the above hot water is supplied, it becomes easy to use. For example, when filling a bath with hot water, a large amount of high-temperature hot water is required. Therefore, when hot water that does not require reheating is supplied, the hot water becomes easy to fill.
However, conventionally, during the non-power generation time period, the hot water storage tank is replenished with an amount of water corresponding to the amount of hot water in the hot water tank supplied to each dwelling unit while the heating by the exhaust heat of the power generation means is stopped. Therefore, the temperature of the hot water in the hot water tank gradually decreases with the use of hot water in each dwelling unit, and becomes a considerably low temperature that is difficult to use in each dwelling unit.
Multiple dwelling units include dwelling units with various life patterns that differ in hot water usage time, but as mentioned above, the temperature of hot water in the hot water tank is difficult to use during non-power generation time. Then, in the dwelling unit with a lifestyle that uses a lot of hot water during non-power generation hours, the temperature of the supplied hot water is considerably lower than the dwelling unit with a usage pattern of hot water during a set power generation time, It becomes inequality.
Moreover, since the hot water heated by the exhaust heat of the power generation means in the set power generation time zone is intended for hot water stored in the hot water storage tank in a full state, the usage amount of the plurality of dwelling units as a whole In some cases, an unnecessarily large amount of hot water is used, and in that case, it is difficult to heat the hot water to a high temperature because of an unnecessarily large amount of hot water.
[0006]
The present invention has been made in view of such circumstances, and its purpose is to supply hot water that is easy to use to a plurality of dwelling units through a set power generation time zone and a non-power generation time zone. To provide a cogeneration system capable of supplying hot water as evenly as possible to a plurality of dwelling units including dwelling units with different use time zones, and capable of increasing the temperature of hot water supplied to the plurality of dwelling units as much as possible. is there.
[0007]
[Means for Solving the Problems]
 [Invention of Claim 1]
 The cogeneration system according to claim 1 is a power generation means for generating power for an area or an apartment house as a power supply target, an exhaust heat recovery heat exchanger to which exhaust heat from the power generation means is supplied, the area or an apartment house. A hot water storage tank for storing hot water for a plurality of contained units, hot water storage means for supplying hot water to the hot water storage tank, exhaust heat recovery circulation for circulating hot water between the exhaust heat recovery heat exchanger and the hot water storage tank A hot water supply circulation means for circulating hot water in a hot water supply circulation path extending between the hot water storage tank and the plurality of dwelling units, and an operation control means for controlling operation,
 The hot water tank is configured as an open type with an open top,
 The operation control means is
 The power generation means and the exhaust heat recovery circulation means are operated in a set power generation time zone set as a part of a day, and the power generation is performed in a non-power generation time zone other than the set power generation time zone. And the exhaust heat recovery circulation means are stopped, and
 A storage amount that can be consumed or substantially consumed in the non-power generation time zone is set as the target storage amount of the hot water tank, and in the set power generation time zoneHasoThe tank water supply means is operated to store the target storage amount ofIn the non-power generation time period, the tank water supply means is stopped.In the set power generation time zone and the non-power generation time zone, the operation is controlled in such a manner that the hot water supply circulation means is operated to consume hot water stored in the hot water storage tank. Is a characteristic configuration.
 That is, the power generation means and the exhaust heat recovery circulation means are operated in a set power generation time zone set as a part of the day, and the power generation means in a non-power generation time zone other than the set power generation time zone. In the hot water storage tank, the waste heat recovery circulation means is stopped, and in the set power generation time zone, the storage amount becomes the target storage amount set to the storage amount that can be consumed or substantially consumed in the non-power generation time zone. While the hot water in the hot water storage tank is heated by the exhaust heat from the power generation means while being supplied with water, the hot water in the hot water storage tank is circulated through the circulation path for hot water supply. The hot water in the hot water tank is circulated through the hot water circulation path while the water supply is stopped, and the hot water tank that circulates through the hot water circulation path in each dwelling unit through the set power generation time zone and the non-power generation time zone. No hot water is used And thus.
 In other words, since the water supply to the hot water tank is stopped in the non-power generation time zone, it is possible to suppress a decrease in the temperature of the hot water in the hot water tank, and even in the non-power generation time zone, the set power generation time zone In the same way, it is possible to store hot water that is easy to use in the hot water storage tank, and storage that can be consumed or substantially consumed in the non-power generation time zone by heating the hot water due to the exhaust heat of the power generation means in the set power generation time zone. Since it is performed for hot water stored in the hot water tank with the target storage volume set to the amount, it is performed unnecessarily for a large amount of hot water for the usage amount as a whole of multiple dwelling units. The state can be avoided, and the hot water in the hot water tank is easily heated to the highest possible temperature.
 Therefore, it is possible to supply high-temperature hot water that is easy to use to a plurality of dwelling units through a set power generation time zone and a non-power generation time zone. It is possible to provide a cogeneration system that can supply hot water to a plurality of dwelling units and that can increase the temperature of hot water supplied to a plurality of dwelling units as much as possible.
[0008]
[Invention of Claim 2]
The cogeneration system according to claim 2 is the cogeneration system according to claim 1, wherein each of the plurality of dwelling units is provided with a water heater that supplies hot water to a hot water demand section using hot water supplied through the hot water circulation means.
A circulation water supply means for supplying water from a water supply source to the hot water supply circulation path is provided;
The hot water circulation means is configured to circulate hot water in the hot water storage tank through the hot water circulation path, stop hot water circulation in the hot water storage tank, and stop the circulation of hot water in the hot water tank to supply the hot water in the circulation water supply means. It is configured to be switchable between the water supply state for supplying water to the circulation path,
The operation control means is configured to switch the hot water supply circulation means from the hot water tank hot water circulation state to the water supply state when the storage amount of the hot water tank reaches a set lower limit storage amount in the non-power generation time zone. This is the characteristic configuration.
That is, when the storage amount of the hot water storage tank reaches the set lower limit storage amount, the hot water circulation of the hot water storage tank through the hot water supply circulation path is stopped, and water from the water supply source is supplied to the hot water supply circulation path. The hot water is supplied to the hot water demand section by a hot water heater using water from a water supply source supplied through a hot water supply circulation path.
In other words, even if the storage amount of the hot water tank becomes the set lower limit storage amount and hot water cannot be supplied from the hot water tank to each dwelling unit, in each dwelling unit, from the water supply source supplied through the hot water circulation path Hot water can be supplied with a water heater using water.
Therefore, the advantage by the characteristic structure of Claim 1 can be acquired, avoiding generation | occurrence | production of the malfunction that hot water supply stops in each dwelling unit.
[0009]
[Invention of Claim 3]
The cogeneration system according to claim 3 is provided with auxiliary hot water storage tank heating means for heating hot water in the hot water tank in claim 2,
In the non-power generation time zone, the operation control unit is configured to perform the non-power generation even when the storage amount of the hot water storage tank becomes the set lower limit storage amount, or even if the storage amount of the hot water storage tank does not become the set lower limit storage amount or less. At the end of the set time period, the hot water circulation means is switched from the hot water tank hot water circulation state to the water supply state, and the hot water in the hot water tank is maintained at a water quality maintenance temperature at which the quality of the hot water can be maintained. The hot water storage tank water quality maintenance operation is performed to heat the hot water tank auxiliary heating means so as to heat the hot water tank.
That is, when the storage amount of the hot water storage tank is less than or equal to the set lower limit storage amount in the non-power generation time zone, or when the storage amount of the hot water storage tank is not less than or equal to the set lower limit storage amount, The circulation of the hot water in the tank is stopped, and the hot water storage tank water quality maintenance operation is performed in which the hot water in the hot water tank is heated to a water quality maintenance temperature (for example, about 60 ° C.) by the auxiliary heating means for the hot water tank.
And since the hot water of a hot water tank is heated to water quality maintenance temperature by hot water tank water quality maintenance operation, the fall of the quality of the hot water supplied to each dwelling unit can be controlled.
In addition, the hot water storage water quality maintenance operation that heats the hot water in the hot water tank to the water quality maintenance temperature in order to maintain the water quality is performed in a state where the amount of hot water to be heated is reduced, thus reducing the energy consumption for maintaining the water quality. It becomes possible to do.
Therefore, it has become possible to suppress the deterioration of the quality of hot water supplied to each dwelling unit while reducing the running cost.
[0010]
[Invention of Claim 4]
A cogeneration system according to a fourth aspect of the present invention is the cogeneration system according to the third aspect, wherein the hot water storage tank includes a main storage section and a small storage section having a smaller cross-sectional area than the main storage section.
When the main storage part and the small storage part communicate with each other, and the storage amount of the hot water storage tank is equal to or less than the set lower limit storage amount, the entire amount is stored in the small storage part, and the storage amount of the hot water storage tank is set to the setting When the amount is larger than the lower limit storage amount, the set lower limit storage amount is stored in the small storage unit, and the amount exceeding the set lower limit storage amount is stored in the main storage unit. And
That is, when the storage amount of the hot water storage tank reaches the set lower limit storage amount, the entire amount of hot water is stored in the small storage section, and the non-power generation time even if the storage amount of the hot water storage tank does not fall below the set lower limit storage amount. At the end of setting in the belt, the storage amount of the hot water tank is reduced to a state close to the set lower limit storage amount, so that substantially the entire amount of hot water is stored in the small storage portion.
That is, in the hot water tank water quality maintenance operation, the total amount or almost the entire amount of hot water is stored in a small storage part having a smaller cross-sectional area than the main storage part, while reducing the amount of hot water stored in the hot water tank as much as possible. However, since the stored water level can be increased as much as possible, it is possible to appropriately circulate the hot water to be heated with respect to the auxiliary heating means for the hot water tank and effectively agitate it with a pump, etc. It becomes possible to reduce the amount of the target hot water.
Accordingly, the hot water storage auxiliary heating means heats the water to the water quality maintenance temperature while effectively stirring a small amount of hot water, so that it is possible to further reduce energy consumption for maintaining the water quality.
[0011]
[Invention of Claim 5]
The cogeneration system according to claim 5 is the cogeneration system according to any one of claims 2 to 4, wherein the hot water circulation means stops circulation of hot water in the hot water storage tank, and the hot water in the hot water circulation path is Over the entire length or substantially the entire length of the hot water supply circulation path, it is configured to be switchable to a water replacement state for replacement with water supplied by the circulation water supply means,
The operation control means stops the operation of the hot water supply circulation means in the hot water tank hot water circulation state until the next time the hot water supply circulation means is operated in the hot water tank hot water circulation state. Further, the present invention is characterized in that a water replacement operation is performed in which the hot water supply circulation means is operated in the water replacement state.
That is, hot water in the hot water supply circulation path is supplied over the entire length or substantially the entire length of the hot water supply circulation path from the end of the hot water tank hot water circulation state to the start of the next hot water tank hot water circulation state. A water replacement operation is performed in which the water is replaced with new water from the water source.
That is, since the hot water in the hot water supply circulation path is replaced with new water from the water supply source over the entire length or substantially the entire length of the hot water supply circulation path by the water replacement operation, the quality of hot water supplied to each dwelling unit is deteriorated. Can be suppressed.
Since the water replacement operation is executed between the end of the hot water tank hot water circulation state and the start of the next hot water tank hot water circulation state, the water replacement operation is performed corresponding to a time zone in which the demand for hot water supply is high. Therefore, there is no problem that the hot water circulation state of the hot water tank is interrupted and the hot water supply to each dwelling unit is hindered.
Therefore, the hot water in the hot water supply circulation path is replaced with new water from the water supply source over the entire length or substantially the entire length of the hot water supply circulation path without causing problems such as hindering the hot water supply to each dwelling unit. It has become possible to suppress deterioration of the quality of hot water supplied to each dwelling unit.
[0012]
[Invention of Claim 6]
The cogeneration system according to claim 6 is provided with an auxiliary heating means for circulation path for heating hot water in the circulation path for hot water supply according to any one of claims 2 to 5,
The operation control means stops the operation of the hot water supply circulation means in the hot water tank hot water circulation state until the next time the hot water supply circulation means is operated in the hot water tank hot water circulation state. In addition, the circulation path water quality maintenance operation is performed to heat the circulation path auxiliary heating means so as to heat the hot water in the hot water circulation path to a water quality maintenance temperature capable of maintaining the quality of the hot water. This is the characteristic configuration.
That is, the hot water in the hot water circulation path is brought to the water quality maintenance temperature by the auxiliary heating means for the hot water tank between the end of the hot water tank hot water circulation state and the start of the next hot water tank hot water circulation state. The circulation path water quality maintenance operation to heat is performed.
That is, since the hot water in the hot water supply circulation path is heated to the water quality maintenance temperature by the circulation path water quality maintenance operation, it is possible to suppress a decrease in the quality of the hot water supplied to each dwelling unit.
Then, the circulation path water quality maintenance operation is executed during a period of time when there is little demand for hot water supply in each dwelling unit, from the end of the hot water bath hot water circulation state to the start of the next hot water bath hot water circulation state. This makes it possible to reduce the amount of hot water supplied from the hot water supply circulation path to each dwelling unit while the hot water tank hot water circulation state is being executed, and is consumed in the circulation path water quality maintenance operation. Energy can be reduced.
Accordingly, it is possible to suppress the deterioration of the quality of the hot water supplied to each dwelling unit by heating the hot water in the hot water supply circulation path to the water quality maintenance temperature while reducing the energy consumption.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described based on the drawings.
As shown in FIG. 1, the cogeneration system includes a generator 1 as a power generation means that generates electricity for an apartment house as a power supply target, a heat exchanger 2 for exhaust heat recovery to which exhaust heat from the generator 1 is supplied, Hot water is stored over the hot water storage tank 3 for storing hot water for a plurality of dwelling units H included in the apartment house, water supply means W1 for the water supply to the hot water storage tank 3, the heat exchanger 2 for exhaust heat recovery, and the hot water storage tank 3. Circulating means C1 for exhaust heat recovery to circulate, circulating means C2 for hot water supply for circulating hot water in a hot water supply circulation path R extending between the hot water storage tank 3 and the plurality of dwelling units H included in the apartment house, and a receiving tank 5 as a water supply source Water supply means W2 for supplying water to the circulation route R for hot water supply, water supply means W3 for dwelling units for supplying water to each of the plurality of dwelling units H included in the apartment house, and control for controlling the operation of the cogeneration system The hot water supply which supplies the hot water supply part in the dwelling unit H using the hot water supplied through the circulation means C2 for hot water supply to each of the some dwelling units H which provide the operation control part U as a control means, and is included in an apartment house. A device K is provided.
[0014]
The cogeneration system includes a hot water tank auxiliary heating means B1 for heating hot water in the hot water tank 3, a circulation path auxiliary heating means B2 for heating hot water flowing through the hot water supply circulation path R, and the generator 1. An auxiliary heating heat exchanger 6 for heating hot water flowing through the hot water supply circulation path R is provided.
[0015]
Further, the cogeneration system is provided with a power receiving / transforming facility 62 that collectively receives power from the commercial power supply 61, and an interconnection device 63 that interconnects the generator 1 with the commercial power supply 61. The feeder line 64 is wired so that the electric power from the commercial power supply 61 is supplied to the power consuming device in the common part and the power consuming device of each dwelling unit H included in the apartment house.
[0016]
In other words, the generator 1 includes a gas engine (not shown) that uses city gas supplied through the common part gas supply path 7 as fuel, and is configured to be driven by the gas engine. is there.
And the cooling water circulation path 8 which circulates engine cooling water over the gas engine and the exhaust heat recovery heat exchanger 2 is provided, and further, part of the engine cooling water is divided and circulated to the auxiliary heating heat exchanger 6. The cooling water circulation path 8 and the auxiliary heating heat exchanger 6 are connected to each other through the cooling water flow three-way valve V1 through the branch flow circulation path 8b, and the cooling water circulation path 8 is provided with a cooling water circulation pump P1. It is. Then, by operating the cooling water circulation pump P1, the engine cooling water is circulated through the gas engine, the exhaust heat recovery heat exchanger 2 and the auxiliary heating heat exchanger 6.
[0017]
The tank water supply means W 1 includes a tank water supply path 9 for supplying water from the water receiving tank 5 to the hot water storage tank 3, and a tank water supply pump P 2 provided in the tank water supply path 9.
When the tank water supply pump P2 is operated, the tank water supply means W1 is operated, and the stored water in the water receiving tank 5 is supplied to the hot water storage tank 3 through the tank water supply path 9, and the tank water supply pump P2 is stopped. Then, the operation of the tank water supply means W1 is stopped.
The tap water is supplied to the water receiving tank 5, and detailed description and illustration are omitted, but the supply of tap water is interrupted so that the stored water level of the water receiving tank 5 becomes the set water level.
[0018]
The hot water storage tank 3 includes a main storage portion 3m and a small storage portion 3s having a smaller cross-sectional area than the main storage portion 3m, and the main storage portion 3m and the small storage portion 3s communicate with each other to store hot water. When the storage amount of the tank 3 is equal to or less than the set lower limit storage amount, the entire amount is stored in the small storage unit 3s. When the storage amount of the hot water storage tank 3 is larger than the set lower limit storage amount, the set lower limit storage amount is the small storage unit 3s. The amount that is stored and exceeds the set lower limit storage amount is provided so as to be stored in the main storage portion 3m. Incidentally, the set lower limit storage amount is set to, for example, about 10% of the storage amount in the hot water tank 3 in the full water state.
[0019]
Specifically, an open main reservoir 3m having an open top and a sealed small reservoir 3s having a smaller cross-sectional area than the main reservoir 3m are separated from each other, and the small reservoir 3s It is provided in a state positioned below the bottom of the main reservoir 3m, and the bottom of the main reservoir 3m and the upper part of the small reservoir 3s are communicated with each other through a communication passage 3c.
In addition, a water level sensor L is provided in the main reservoir 3m of the reservoir 3.
[0020]
The exhaust heat recovery circulation means C1 is piped to flow the hot water taken out from the bottom of the small storage part 3s of the hot water tank 3 through the exhaust heat recovery heat exchanger 2 so as to return from the upper part of the main storage part 3m. The exhaust heat recovery circulation path 10, the branch path 10 b that branches from the downstream portion of the exhaust heat recovery heat exchanger 2 in the exhaust heat recovery circulation path 10 and returns the hot water to the small reservoir 3 s, and the branch The tank hot water circulation switching three-way valve V2 provided in the part and the exhaust heat recovery circulation pump P3 provided in the exhaust heat recovery circulation path 10 are provided.
That is, when the exhaust heat recovery circulation pump P3 is operated, the exhaust heat recovery circulation means C1 is operated, and when the operation of the exhaust heat recovery circulation pump P3 is stopped, the exhaust heat recovery circulation means C1 is As the tank water and water circulation switching three-way valve V2 is switched, the return path portion of the exhaust heat recovery circulation path 10 (the flow path portion connected to the outlet of the exhaust heat recovery heat exchanger 2) passes through. It is configured to be switchable between a normal circulation state in which the flowing hot water is returned to the main storage portion 3m and a hot-water circulation state in which the hot water flowing through the return portion of the exhaust heat recovery circulation path 10 is returned to the small storage portion 3s. It is.
[0021]
The hot water supply circulation means C2 includes a hot water supply circulation path R extending between the hot water storage tank 3 and the plurality of dwelling units H included in the apartment house, and an upstream circulation pump P4 and a downstream circulation pump P5 provided in the hot water supply circulation path R. Each dwelling unit H is connected to a dwelling unit hot water supply channel 11 that supplies hot water flowing through the hot water supply circulation path R to each dwelling unit H, and each dwelling unit hot water supply channel 11 is connected to each dwelling unit H A hot water supply amount sensor Q3 for each dwelling unit that detects the flow rate of hot water supplied to the house is provided.
[0022]
The hot water supply circulation path R will be described. The hot water extracted from the small storage part 3s of the hot water storage tank 3 is piped to flow back to the upper part of the main hot water storage part 3m via the plurality of dwelling units H included in the apartment house, and the circulation path 4 via the tank is provided. A tank return stop three-way valve V3 is provided on the downstream side of the tank-passage circuit 4 through the dwelling unit, and the tank return stop three-way valve V3 and the tank-passage circuit 4 on the upstream side of the dwelling unit are bypassed. In addition, a check valve 13 is provided on the upstream side of the connection point of the tank bypass path 12 in the tank circulation path 4, and the tank return circulation path is switched by switching the tank return stop three-way valve V3. It is possible to switch between a tank return state in which hot water flowing through 4 flows into the hot water storage tank 3 and a tank return stop state in which hot water flowing through the tank circulation path 4 stops flowing into the hot water storage tank 3. It is configured.
The upstream circulation pump P4 is provided on the upstream side of the connection point of the tank bypass path 12 on the upstream side of the passage through the dwelling unit of the tank circulation path 4, and the downstream circulation pump P5 is passed through the dwelling unit in the circulation path 4 of the tank. It is provided downstream of the location and upstream of the tank return stop three-way valve V3.
[0023]
Then, when the tank return stop three-way valve V3 is switched to the tank return stop state and the upstream circulation pump P4 and the downstream circulation pump P5 are operated, the hot water taken out from the hot water storage tank 3 passes through the tank circulation path 4. It flows through a plurality of dwelling units H, and further circulates in a hot water tank bypass route that flows from the tank return stop three-way valve V3 through the tank bypass passage 12 and back to the tank circulation route 4, and the hot water tank bypass route. As the hot water flowing through the hot water is used in each dwelling unit H, the hot water in the hot water storage tank 3 is replenished to the hot water tank bypass path by the upstream circulation pump P4.
That is, the hot water supply circulation path R extending between the hot water storage tank 3 and the plurality of dwelling units H is a hot water storage tank that passes through the plurality of dwelling units H in a state of bypassing the hot water storage tank 3 using the tank circulation path 4 and the tank bypass path 12. The hot water supply circulation means C2 is configured to circulate through the hot water supply circulation path R while supplementing the hot water in the hot water storage tank 3 to the hot water supply circulation path R.
[0024]
Further, an auxiliary heating heat exchanger 6 is provided on the downstream side of the passage through the dwelling unit 4 and upstream of the tank return stop three-way valve V3, and the auxiliary heating heat exchanger 6 The hot water flowing through the hot water supply circulation path R is heated. That is, the hot water flowing through the hot water supply circulation path R is heated by the exhaust heat of the generator 1 in the auxiliary heating heat exchanger 6 so as to suppress a temperature drop due to heat radiation.
[0025]
The water supply means for circulation W2 is connected to the downstream side of the connection point of the tank bypass path 12 on the upstream side of the passage through the dwelling unit of the tank passage circulation path 4, and supplies the water from the water receiving tank 5 to the circulation path R for hot water supply. And a water supply switching three-way valve V4 provided at a connection portion of the circulation water supply path 14 in the tank-by-tank circulation path 4 and a circulation / dwelling unit water supply pump P6 provided in the circulation water supply path 14. It is.
That is, the flow of hot water from the hot water storage tank 3 is stopped by the water supply switching three-way valve V4, and the water supply line connection state for supplying water from the circulation water supply path 14 to the hot water supply circulation path R and the water supply from the circulation water supply path 14 are performed. It is configured so that it can be switched to a water supply channel shut-off state in which the hot water from the hot water storage tank 3 is stopped and stopped.
[0026]
Further, the dwelling unit water supply channel 15 is branched from the circulation water supply channel 14, and the dwelling unit water supply channel 15 is piped to supply water to each of the plurality of dwelling units H. The dwelling unit water supply means W3 is a circulating water supply channel. 14, a dwelling unit water supply path 15, and a circulation / dwelling unit water supply pump P 6.
[0027]
An auxiliary water heater B that serves as both the hot water tank auxiliary heating means B1 and the circulation path auxiliary heating means B2 is provided.
The auxiliary water heater B includes first and second heat exchangers 71 and 72, a gas burner 73 that heats the first and second heat exchangers 71 and 72, and combustion air to the gas burner 73. An air blower 74 is provided for ventilation.
The inlet of the first heat exchanger 71 is provided with a first water supply amount sensor Q1 for detecting the flow rate of hot water supplied to the first heat exchanger 71, and the outlet of the first heat exchanger 71 is provided with the first water supply sensor Q1. 1 A first hot water temperature sensor T1 for detecting the temperature of hot water discharged from the heat exchanger 71 is provided, and the flow rate of hot water supplied to the second heat exchanger 72 is set at the inlet of the second heat exchanger 72. A second water supply amount sensor Q2 for detection is provided, and a second hot water temperature sensor T2 for detecting the temperature of hot water discharged from the second heat exchanger 72 is provided at the outlet of the second heat exchanger 72.
The gas burner 73 is connected to a common part gas supply path 7. The common part gas supply path 7 has a gas intermittent valve 75 for intermittently supplying gas and a gas proportional valve 76 for adjusting a gas supply amount. Is provided.
[0028]
The operation of the auxiliary water heater B is performed by the operation control unit U. The operation control unit U causes the hot water to flow to at least one of the first heat exchanger 71 and the second heat exchanger 72, and the first Based on the fact that the detected hot water flow rate of at least one of the water supply amount sensor Q1 and the second water supply amount sensor Q2 is equal to or greater than the set amount, the blower 74 is activated and the gas intermittent valve 75 is opened, and an ignition plug (not shown) , The gas burner 73 is ignited, the amount of combustion is adjusted by adjusting the opening of the gas proportional valve 76 as will be described later, and the detected hot water flow rates of both the first water supply amount sensor Q1 and the second water supply amount sensor Q2 are When it becomes less than the set amount, the gas intermittent valve 75 is closed to extinguish the gas burner 73, and then the blower 74 is stopped.
[0029]
Then, the hot water flowing through the hot water supply circulation path R is passed through the first heat exchanger 71 and then returned to the hot water supply circulation path R so as to be supplied to each dwelling unit H. A portion upstream of the via point and the first heat exchanger 71 are connected by the auxiliary heating flow path 16, and the tank passing circulation path 4 is connected to the connecting portion between the tank passing circulation path 4 and the auxiliary heating flow path 16. There is provided an auxiliary heating switching three-way valve V5 for switching between an auxiliary heating state in which flowing hot water is passed through the first heat exchanger 71 and an auxiliary heating stopped state in which the hot water is not passed.
A hot water storage tank take-off temperature sensor T3 for detecting the temperature of hot water taken out from the hot water storage tank 3 is provided at a location upstream of the connection location with the auxiliary heating flow path 16 in the through-tank circulation path 4. A dwelling unit supply temperature sensor T4 that detects the temperature of the hot water supplied to each dwelling unit H is provided upstream of the dwelling unit location and downstream of the auxiliary heating channel 16 connection point.
[0030]
Further, the hot water flowing through the forward path part (the flow path part connected to the inlet of the exhaust heat recovery heat exchanger 2) in the exhaust heat recovery circulation path 10 is bypassed through the exhaust heat recovery heat exchanger 2, After passing the second heat exchanger 72, the exhaust heat recovery is performed so as to return to the return path portion (the channel portion connected to the outlet of the exhaust heat recovery heat exchanger 2) in the exhaust heat recovery circulation path 10. The circulation path 10 for use and the second heat exchanger 72 are connected by a tank temperature raising flow path 17, and hot water is connected to each of the connecting portions between the tank temperature raising flow path 17 and the exhaust heat recovery circulation path 10. A hot water storage tank side tank temperature increase switching three-way valve V6 that switches between an exhaust heat recovery state in which water is passed through the heat recovery heat exchanger 2 and a tank temperature increase state in which hot water is passed through the second heat exchanger 71, The tank temperature increasing flow path 17 is provided with a tank temperature increasing pump P7. Further, a small storage for detecting a temperature for extracting hot water from the small storage section 3s of the hot water storage tank 3 is located upstream of the hot water storage tank side tank temperature increase switching three-way valve V6 in the forward path portion of the exhaust heat recovery circulation path 10. A part take-out temperature sensor T5 is provided.
[0031]
Furthermore, after the hot water flowing through the forward path portion (portion connected to the inlet of the second heat exchanger 72) in the tank temperature raising flow path 17 is diverted to the first heat exchanger 71, the tank The flow path 17 for raising the temperature of the tank and the auxiliary heating flow path 16 are separated by the shunt flow path 18 so as to return to the return path portion (the portion connected to the outlet of the second heat exchanger 72) of the temperature rise flow path 17. An auxiliary heating state in which hot water from the hot water supply circulation path R is allowed to flow through the first heat exchanger 71 and the first heat exchange are connected to each of the connecting portions of the auxiliary heating flow path 16 and the diversion flow path 18. A hot water heater side tank temperature increase switching three-way valve V7 is provided to switch the tank 71 to a tank temperature increase state in which hot water from the tank temperature increase flow path 17 is allowed to flow.
[0032]
Then, when the tank return stop three-way valve V3 is switched to the tank return stop state and the water supply switching three-way valve V4 is switched to the water supply channel shut-off state, the upstream circulation pump P4 and the downstream circulation pump P5 are operated. The hot water in the hot water storage tank 3 is circulated in the hot water supply circulation path R, and the hot water storage tank is in a hot water circulation state.
In addition, the tank return stop three-way valve V3 is switched to the tank return stop state, the water supply switching three-way valve V4 is switched to the water supply channel connection state, and the upstream circulation pump P4 and the downstream circulation pump P5 are stopped. When the circulation / dwelling unit water supply pump P6 is operated, a water supply state is reached in which water from the water receiving tank 5 serving as a water supply source is supplied to the hot water supply circulation path R.
Also, the water supply switching three-way valve V4 is switched to the water supply channel connection state, the auxiliary heating switching three-way valve V5 is switched to the auxiliary heating stop state, the tank return stop three-way valve V3 is switched to the tank return state, and upstream circulation If the circulation / dwelling unit water supply pump P6 is operated for the set water replacement time while the pump P4 and the downstream side circulation pump P5 are stopped, the circulation of hot water in the hot water storage tank 3 is stopped and received as a water supply source. Water from the water tank 5 is supplied so as to be supplied to the hot water storage tank 3 through the hot water supply circulation path R, and the hot water in the hot water supply circulation path R is supplied by the circulation water supply means W2 over substantially the entire length of the hot water supply circulation path R. It will be in the water substitution state which substitutes with the supplied water.
That is, the hot water supply circulation means C2 is configured to be switchable between the hot water tank hot water circulation state, the water supply state, and the water replacement state.
[0033]
Further, with the hot water supply circulation means C2 switched to the hot water tank hot water circulating state, the auxiliary heating switching three-way valve V5 is switched to the auxiliary heating state, and the hot water heater side tank temperature rising switching three-way valve V7 is switched to the auxiliary heating state. When the burner 73 is burned, the hot water flowing through the hot water supply circulation path R can be heated by the first heat exchanger 71.
Also, the tank hot water circulation switching three-way valve V2 is switched to the circulation state when the tank is heated, and the hot water tank side tank temperature switching three-way valve V6 and the water heater side tank temperature switching three-way valve V7 are switched to the tank temperature rising state, respectively. When the exhaust heat recovery circulation pump P3 and the tank temperature raising pump 7 are operated to burn the burner 73, the hot water in the small reservoir 3s is passed through the first and second heat exchangers 71 and 72. It can circulate in the state to make it heat and can heat.
[0034]
Each dwelling unit H is connected to a dwelling unit gas supply path 19 for supplying city gas.
In each dwelling unit H, a dwelling unit gas supply path 19, a dwelling unit hot water supply path 11 branched from the hot water supply circulation path R, and a dwelling unit water supply path 15 are connected to the hot water supply unit K. The hot water supply unit is configured to supply hot water using hot water supplied through the hot water supply circulation means C2 and water supplied through the dwelling unit water supply means W3.
[0035]
Next, the water heater K provided in each dwelling unit H will be described based on FIG.
The water heater K includes a mixing unit Km that mixes hot water supplied from the dwelling water supply channel 11 and water supplied from the dwelling water supply channel 15, and heating in which hot water is supplied from the mixing unit Km as a heating target. The remote control operation part 31 provided with the part Kh and the hot water supply temperature setting part etc. which set the hot water supply target temperature is comprised.
[0036]
The heating unit Kh heats the hot water supplied from the mixing unit Km through the water supply channel 32, and passes through the hot water supply heat exchanger 34 that supplies the heated hot water to the hot water supply channel 33 and the recirculation circuit 35. The heating heat exchanger 36 for heating hot water in a bathtub (not shown), a gas burner 37 for heating the hot water supply heat exchanger 34 and the heating heat exchanger 36, and the operation of the heating unit Kh are controlled. A heating control unit 38 and the like are provided.
[0037]
The gas burner 37 is connected with a gas supply path 19 for dwelling units, and the gas supply path 19 for dwelling units is provided with a gas intermittent valve 39 for intermittently supplying gas and a gas proportional valve 40 for adjusting a gas supply amount. is there.
[0038]
The water supply path 32 is provided with a water supply temperature sensor 41 for detecting the temperature of the supplied hot water and a water supply amount sensor 42 for detecting the flow rate of the supplied hot water. The water supply path 32 and the hot water supply path 33 are connected to the water supply bypass path 43. Connected.
In the hot water supply passage 33, a mixing valve 45 that adjusts the mixing ratio of hot water from the hot water supply heat exchanger 34 and water from the water supply bypass passage 43, and a water proportional valve 50 that adjusts the amount of hot water in order from the upstream side. A hot water temperature sensor 44 for detecting the temperature of the hot water mixed by the mixing valve 45 is provided, and a hot water tap 49 is connected to the tip of the hot water supply passage 33.
A hot water supply passage 46 branched from the hot water supply passage 33 is connected to the forward path portion of the memorial circuit 35, and the hot water supply passage 46 is provided with a hot water opening / closing valve 47.
In addition, a bathtub circulation pump 48 that circulates bathtub water is provided in the return path portion of the memorial circuit 35.
[0039]
The mixing unit Km has a mixing ratio between the hot water supplied from the hot water supply path 11 for dwelling units (that is, the circulation means C2 for hot water supply) and the water supplied from the water supply path 15 for the dwelling units (that is, the water supply means W3 for the dwelling units). The mixing valve 51 to be adjusted, the hot water supply passage opening / closing valve 52 for intermittently supplying hot water from the dwelling hot water supply passage 11 to the mixing valve 51, and the temperature of hot water supplied from the dwelling hot water supply passage 11 to the mixing valve 51 ( Hereinafter, the circulating hot water temperature sensor 53 for detecting the circulating hot water temperature and the temperature of the water supplied to the mixing valve 51 from the dwelling water supply channel 15 (sometimes referred to as the mixing portion water supply temperature) are detected. A feed water temperature sensor 54 that controls the operation of the mixing section Km, a mixing temperature sensor 55 that detects the temperature of hot water flowing out of the mixing valve 51 (hereinafter, sometimes referred to as mixed hot water temperature), and the like. It is constituted comprising a coupling control unit 56 or the like.
[0040]
Next, control operations of the heating control unit 38 and the mixing control unit 56 will be described.
The heating control unit 38 is configured to communicate various control information between the remote control operation unit 31 and the mixing control unit 56.
When the operation switch of the remote control operation unit 31 is turned on, the heating control unit 38 and the mixing control unit 56 can be controlled, and the hot water supply passage opening / closing valve 52 is opened.
When the hot-water tap 49 is opened and the detected hot water flow rate of the water supply amount sensor 42 is equal to or greater than the set amount, the heating control unit 38 sets the hot water supply target set by the remote control operation unit 31 to the mixing control unit 56. The mixing control unit 56 compares the circulating hot water temperature detected by the circulating hot water temperature sensor 53 with the hot water supply target temperature sent from the heating control unit 38, so that the circulating hot water temperature is the target hot water temperature. When the temperature is higher than the temperature lower than the set temperature difference Δt (hereinafter sometimes referred to as non-combustion control temperature), the fact that the circulating hot water temperature is lower than the target hot water supply temperature by at least the set temperature difference Δt In the case of (hereinafter, sometimes referred to as combustion control temperature), the fact is transmitted to the heating control unit 38.
The mixing control unit 56 stores a preset mixing temperature in advance.
[0041]
The set temperature difference Δt is a temperature difference corresponding to a state in which the combustion amount of the gas burner 37 necessary for heating the hot water to be heated to the target hot water supply temperature is larger than the minimum combustion amount of the gas burner 37 (details will be described later). As the set temperature difference Δt, a normal temperature corresponding to a normal hot water supply target temperature range (for example, 37 to 44 ° C.) set in advance by the hot water supply target temperature set by the remote control operation unit 31 is set. A high temperature corresponding to a set temperature difference Δt (for example, 2 ° C.) for the hot water supply target temperature and a high temperature hot water supply target temperature (for example, 60 ° C.) set in advance by the hot water supply target temperature set by the remote control operation unit 31. Two types of temperature difference Δt (for example, 3 ° C.) for the hot water supply target temperature are set.
Further, the set mixed temperature is set to be lower than the set hot water target temperature by a set temperature difference Δt or more, and the set mixed temperature is such that the set hot water target temperature set by the remote controller 31 is within the normal hot water supply target temperature range. The low set mixed temperature (for example, 30 ° C.) set to a temperature lower than the set temperature difference Δt by more than the normal hot water supply target temperature range, and the hot water supply target temperature set by the remote control operation unit 31 Two types of high setting mixed temperature (for example, 45 ° C.) corresponding to the high temperature hot water supply target temperature are set.
[0042]
If the hot water supply target temperature is transmitted from the heating control unit 38 based on the fact that the hot water supply 49 is opened and the hot water flow rate detected by the water supply amount sensor 42 is equal to or greater than the set amount, the mixing control unit 56 The circulating hot water temperature detected by the sensor 53 is compared with the hot water supply target temperature, and when the circulating hot water temperature is the non-combustion control temperature, the circulating hot water temperature sensor 53, the feed water temperature sensor 54, and the mixed temperature sensor 55 are each. Based on the detected temperature, mixing control is performed to adjust the mixing valve 51 so that the mixed hot water temperature detected by the mixed temperature sensor 55 becomes the hot water supply target temperature, and the hot water from the hot water supply path 11 for dwelling units Water from the dwelling water supply channel 15 is mixed, and the fact that the circulating hot water temperature is the non-combustion control temperature is transmitted to the heating control unit 38.
When the mixing control unit 56 transmits that the circulating hot water temperature is the non-combustion control temperature, the heating control unit 38 sets the gas burner 37 to the combustion stopped state.
Accordingly, the hot water supplied from the mixing unit Km to the heating unit Kh is discharged from the hot water tap 49 without being heated by the heating unit Kh, and the hot water at the hot water supply target temperature or the target hot water target temperature is supplied from the hot water supply tap 49. Take a bath.
[0043]
For example, when the hot water supply target temperature is set to 40 ° C., the circulating hot water temperature is higher than 38 ° C., which is a set temperature difference Δt lower than the hot water supply target temperature of 40 ° C., that is, 2 ° C. The non-combustion control temperature is set. And in the range whose circulating hot-water temperature is higher than 38 degreeC and 40 degrees C or less, the hot water from the dwelling unit hot water supply path 11 is discharged as it is, without mixing the water from the dwelling unit water supply path 15, When the circulating hot water temperature is higher than 40 ° C., the hot water from the dwelling water supply channel 11 is mixed with the hot water from the dwelling water supply channel 11 so that the mixed hot water temperature becomes the target hot water supply temperature. .
[0044]
On the other hand, when the circulating hot water temperature is the combustion control temperature, the mixed hot water temperature detected by the mixed temperature sensor 55 is based on the detected temperatures of the circulating hot water temperature sensor 53, the feed water temperature sensor 54, and the mixed temperature sensor 55. The mixing valve 51 is adjusted so that when the hot water supply target temperature is within the normal hot water supply target temperature range, the low setting mixed temperature is reached, or when the hot water supply target temperature is the high temperature hot water supply target temperature, the high setting mixed temperature is reached. Mixing control is executed to mix hot water from the dwelling water supply channel 11 and water from the dwelling water supply channel 15 and transmit to the heating control unit 38 that the circulating hot water temperature is the combustion control temperature. .
When the mixing control unit 56 transmits that the circulating hot water temperature is the temperature for combustion control, the heating control unit 38 burns the gas burner 37, the hot water supply target temperature, the detection temperature of the water supply temperature sensor 41, and the water supply amount sensor. Based on the detected water supply amount 42, feed forward control is performed to adjust the opening of the gas proportional valve 40 and the opening of the mixing valve 45 so that the temperature of the hot water flowing out of the hot water supply heat exchanger 34 becomes the hot water supply target temperature. And the feedback control for finely adjusting the opening of the gas proportional valve 40 based on the deviation between the temperature detected by the hot water supply temperature sensor 44 and the target hot water temperature is executed.
Accordingly, hot water at the hot water supply target temperature is discharged from the hot water tap 49.
[0045]
For example, when the hot water supply target temperature is set to 40 ° C., the circulating hot water temperature is lower than the target hot water supply temperature of 40 ° C. by a set temperature difference Δt, that is, 2 ° C., which is 38 ° C. or less. It becomes the temperature for combustion control. And in the mixing part Km, the water from the dwelling water supply channel 15 is mixed with the hot water from the dwelling water supply channel 11 so that the mixed hot water temperature becomes a low set mixing temperature (for example, 30 ° C.), and the heating unit The hot water is heated to 40 ° C. as the hot water supply target temperature and discharged.
[0046]
That is, when the circulating hot water temperature is lower than the target hot water temperature by a set temperature difference Δt or more, the hot water heater K is set to the set mixed temperature set to be lower than the set hot water target temperature by a set temperature difference Δt or more. In addition, the mixing operation of the mixing unit Km is controlled, and the heating operation of the heating unit Kh is controlled so that the hot water supply temperature becomes the target hot water supply temperature, and the circulating hot water temperature is lower than the target hot water supply temperature by a set temperature difference Δt. When the temperature is higher than the temperature, the mixing operation of the mixing unit Km is controlled so that the hot water supply temperature becomes the target hot water supply temperature while the heating operation of the heating unit Kh is stopped.
[0047]
When the temperature of the hot water from the hot water supply circulation means C2 is the combustion control temperature, the hot water from the hot water supply circulation means C2 and the hot water from the hot water supply circulation means C2 are adjusted so that the temperature can be stably adjusted to the hot water supply target temperature. Since the water from the dwelling unit water supply means W3 is mixed and then heated to the hot water supply target temperature by the heating unit Kh, the difference between the hot water temperature from the hot water supply circulation means C2 and the hot water supply target temperature is Even when the temperature is small, hot water at the hot water supply target temperature or approximately the hot water supply target temperature is obtained.
In other words, in order to ensure the combustion stability of the gas burner 37, the combustion amount of the gas burner 37 is not restricted to be smaller than a predetermined minimum combustion amount. Accordingly, when the hot water mixing control as described above, that is, the control for mixing the hot water from the hot water circulating means C2 and the water from the dwelling water supply means W3 so as to reach the set mixing temperature, is not performed. When the difference between the hot water temperature from C2 and the target hot water supply temperature is small and the combustion amount obtained based on the difference is smaller than the minimum combustion amount, for example, the gas burner 37 is burned at the minimum combustion amount. Therefore, there arises a problem that it is difficult to adjust the temperature of the hot water to be discharged to the hot water supply target temperature. Therefore, the above-described problems can be solved by performing the hot and cold water mixing control as described above.
[0048]
Next, the operation control unit U will be described.
The operation control unit U operates the generator 1 and the exhaust heat recovery circulation means C1 in a set power generation time zone set as a part of the day, and generates non-power generation other than the set power generation time zone. In a mode in which the generator 1 and the exhaust heat recovery circulation means C1 are stopped in the time zone, and the storage amount that can be consumed or substantially consumed in the non-power generation time zone is set as the target storage amount of the hot water tank 3, and set In the power generation time zone, the tank water supply means W1 is operated to store the target storage amount, and in the set power generation time zone and the non-power generation time zone, hot water is supplied to consume hot water stored in the hot water storage tank 3. The operation is controlled in such a manner that the circulating means C2 is operated.
The operation control unit U is configured to switch the hot water supply circulation means C2 from the hot water tank hot water circulation state to the water supply state when the storage amount of the hot water tank 3 reaches the set lower limit storage amount in the non-power generation time period. It is.
In addition, the operation control unit U is in the non-power generation time zone when the storage amount of the hot water storage tank 3 becomes the set lower limit storage amount in the non-power generation time zone, or even if the storage amount of the hot water storage tank 3 does not fall below the set lower limit storage amount. At the end of the setting, the hot water supply circulation means C2 is switched from the hot water tank hot water circulation state to the water supply state, and the hot water in the hot water tank 3 is heated to a water quality maintenance temperature capable of maintaining the quality of the hot water. Thus, the hot water storage tank water quality maintaining operation for heating the auxiliary heating water heater B is performed.
The operation control unit U stops operating the hot water circulating means C2 in the hot water tank hot water circulating state and then operates the hot water circulating means C2 in the hot water tank hot water circulating state. In the meantime, the water replacement operation for operating the hot water supply circulation means C2 in the water replacement state is executed.
[0049]
The storage unit built in the operation control unit U continues the set power generation time zone, the set lower limit water level that is the water level of the hot water tank 3 corresponding to the set lower limit amount, the water quality maintenance temperature, and the hot water tank water quality maintenance operation. The preset water quality maintenance operation time, the preset water replacement time, and the target heating temperature for heating the hot water flowing through the hot water supply circulation path R in the auxiliary water heater B are set and stored in advance. It is.
By the way, as the set power generation time zone, two types of summer intermediate period and winter season are set and stored. The summer power generation set power generation time zone is a time zone in which there is much power demand. The set power generation time zone for the winter season is longer than the set power generation time zone for the winter season so as to correspond to the heat demand. It is set to the time zone from midnight to 23:00. A time zone (24 hours) including the set power generation time zone and the non-power generation time zone is referred to as one cycle.
[0050]
Since the set lower limit storage amount is set to the storage amount in the full water state in the small storage portion 3s, the set lower limit water level is set to a water level at which the water level of the main storage portion 3m becomes zero. That is, when the water level of the hot water storage tank 3 is the set lower limit water level, the entire amount of hot water can be stored in the small storage part 3s and not stored in the main storage part 3m.
[0051]
The water quality maintenance temperature is set to 60 ° C., for example, and the set water quality maintenance operation time is set to 1 hour, for example.
The set water replacement time is such that the water in the water receiving tank 5 that has flowed into the hot water supply circulation path R when the water supply switching three-way valve V4 is switched to the water supply path connection state flows into the hot water storage tank 3 through the hot water supply circulation path R. On the other hand, it is set longer than the time required to flow out.
[0052]
The target heating temperature is set to a temperature outside the normal hot water supply target temperature setting range (for example, 37 to 44 ° C.) that can be set by the remote control operation unit 31 of the water heater K provided in each dwelling unit H.
And the said target heating temperature is set to the same temperature (for example, 30 degreeC) as the said low setting mixing temperature lower than the said normal hot water supply target temperature setting range, and is used in winter (for example, December to February). A winter target heating temperature and a summer intermediate target heating temperature that is set to a temperature (for example, 45 ° C.) higher than the normal hot water supply target temperature setting range and used in a period other than the winter period are stored.
[0053]
The hot water supply circulation means C2 is provided with thermal load detection means for detecting the heat quantity of hot water supplied to the plurality of dwelling units H included in the apartment house as a thermal load, and the non-detection detected by the thermal load detection means. The heat load in the power generation time zone (hereinafter sometimes simply referred to as a non-power generation time zone heat load) is configured to be stored in the storage unit, and the operation control means U is stored in the storage unit. The target storage amount of the operation target cycle is set based on the storage information of the non-power generation time zone heat load.
[0054]
Specifically, the operation control means U determines the detected flow rate of the hot water supply amount sensor Q3 for each dwelling unit through the non-power generation time period based on the detection information of the hot water supply amount sensor Q3 for each dwelling unit and the supply temperature sensor T4 for each dwelling unit. The total hot water flow rate is multiplied by the temperature detected by the dwelling unit supply temperature sensor T4 to calculate the amount of heat, the amount of heat is calculated, the total amount of heat is calculated as the non-power generation time zone heat load, and stored in the storage means. The stored non-power generation time zone heat load stored information is rewritten to the newly determined non-power generation time zone heat load heat. In other words, the thermal load detecting means is constituted by a dwelling unit hot water supply amount sensor Q3 and a dwelling unit supply temperature sensor T4.
And the operation control means U is based on the non-power generation time zone thermal load stored in the storage means, that is, the non-power generation time zone heat load in the cycle before the operation target cycle. The target storage amount is set.
[0055]
Hereinafter, the control operation of the operation control unit U is divided into power supply control for supplying power to the common unit and each dwelling unit H, and hot water supply control for supplying hot water to each dwelling unit.
First, the control operation of power supply control will be described.
The operation control unit U operates the generator 1 and the cooling water circulation pump P1 in the set power generation time zone, and stops the generator 1 and the cooling water circulation pump P1 in the non-power generation time zone other than the set power generation time zone. In such a form, the generator 1 is automatically operated every day.
During operation of the generator 1, the generator 1 supplies power to the power consuming equipment in the common section and the power consuming equipment of each dwelling unit H, and the output of the generator 1 to these power consuming equipment. Is insufficient, the commercial power supply 61 compensates for the shortage.
In addition, while the generator 1 is stopped, power is supplied from the commercial power supply 61 to the power consuming equipment in the shared section and the power consuming equipment in each dwelling unit H.
During operation of the generator 1, the engine cooling water circulates through the exhaust heat recovery heat exchanger 2 and the auxiliary heating heat exchanger 6 to cool the gas engine, and the exhaust heat is It is supplied to the heat exchanger 2 for exhaust heat recovery and the heat exchanger 6 for auxiliary heating.
[0056]
Next, hot water supply control will be described with reference to FIGS. In FIG. 1 to FIG. 5, each flow path portion in which hot water or engine cooling water flows is indicated by a bold line.
In addition, since the circulation and dwelling unit water supply pump P6 is always operated so that the water of the water receiving tank 5 can be supplied to each dwelling unit H at all times through the dwelling unit water supply channel 15, in the following explanation, the circulation and dwelling unit is used. Description of the operation control of the water supply pump P6 is omitted.
[0057]
With the start of the set power generation time zone, the exhaust heat recovery circulation means C1 is operated, the tank water supply means W1 is operated to store the target storage amount, and the hot water supply circulation means C2 is connected to the hot water storage tank. A normal hot water tank hot water circulating operation that operates in a hot water circulating state is executed.
That is, the exhaust heat recovery circulation pump P3 is operated in a state in which the tank hot water circulation switching three-way valve V2 is switched to the normal circulation state and the hot water tank side tank temperature increase switching three-way valve V6 is switched to the exhaust heat recovery state. By operating the exhaust heat recovery circulation means C1, the upstream side circulation in a state where the water supply switching three-way valve V4 is switched to the water supply channel shut-off state and the tank return stop three-way valve V3 is switched to the tank return stop state. By operating the pump P4 and the downstream circulation pump P5, the hot water supply circulation means C2 is operated in the hot water tank hot water circulation state, and the amount of storage in the hot water tank 3 is determined based on the detection information of the water level sensor L. By operating the tank water supply pump P2 so as to reach the target storage amount, the tank water supply means W1 is operated to store the target storage amount in the hot water storage tank 3.
[0058]
As shown in FIG. 1, in the normal hot water tank hot water circulation operation, the engine cooling water circulates through the heat exchanger 2 for exhaust heat recovery and the heat exchanger 6 for auxiliary heating, and the hot water in the hot water tank 3 is discharged. It circulates through the heat exchanger 2 for exhaust heat recovery in the circulation path 10 for heat recovery, and circulates around a plurality of dwelling units H in the circulation path R for hot water supply. Water is supplied to the hot water storage tank 3 through the tank water supply channel 9 so that the amount is maintained.
That is, the hot water taken out from the small storage part 3s of the hot water storage tank 3 is heated by the heat exchange action with the engine cooling water in the heat exchanger 2 for exhaust heat recovery and returned to the main storage part 3m. 3 is heated, and hot water in the hot water storage tank 3 passes through the plurality of dwelling units H and is heated by the heat exchange action with the engine cooling water in the heat exchanger 6 for auxiliary heating. It circulates through the circulation route R.
[0059]
Further, during the normal hot water tank hot water circulating operation, auxiliary heating control is executed as follows.
That is, when the temperature detected by the hot water tank discharge temperature sensor T3 is equal to or higher than the target heating temperature, the auxiliary heating switching three-way valve V5 is switched to the auxiliary heating stop state. When the temperature detected by the hot water tank discharge temperature sensor T3 is lower than the target heating temperature, the auxiliary heating switching three-way valve V5 is switched to the auxiliary heating state and the water heater side tank temperature rising switching three-way valve V7 is switched to the auxiliary heating state. Switch to. Then, hot water flows through the first heat exchanger of the auxiliary water heater B, and the detected flow rate of the first water supply amount sensor Q1 exceeds the set amount. Based on this, the gas burner 73 is ignited as described above. The combustion amount control is performed so that the temperature of the hot water from the first heat exchanger 71 becomes the heating target temperature. That is, in the combustion amount control, the temperature of hot water flowing out from the first heat exchanger 71 is determined based on the heating target temperature, the detected temperature of the hot water tank take-out temperature sensor T3, and the detected water supply amount of the first water supply amount sensor Q1. The feedforward control is performed to adjust the opening of the gas proportional valve 76 so as to reach the temperature, and the gas proportional valve 76 is opened based on the deviation between the temperature detected by the first hot water temperature sensor T1 and the heating target temperature. Perform feedback control to fine-tune the degree.
[0060]
In each dwelling unit H, hot water is supplied from the hot water heater K using hot water flowing through the hot water supply circulation path R as follows.
That is, in the summer and the intermediate period, the heating target temperature is set to the target heating temperature for the summer intermediate period that is higher than the normal hot water supply target temperature setting range. Since hot water having a temperature higher than the normal hot water supply target temperature setting range flows through the dwelling unit of the circulation path R, in each dwelling unit H, when the hot water supply target temperature is set to the normal hot water supply target temperature setting range, The hot water heater K supplies hot water at the hot water supply target temperature by mixing by the mixing unit Km while the gas burner 37 is in the combustion stopped state. Therefore, in the water heater K of each dwelling unit, operation is performed in such a manner that the water is once mixed so that the set mixed temperature is reached, and then heated so that the hot water temperature becomes the target hot water temperature (hereinafter, heating after water mixing). (Sometimes referred to as driving), so that energy saving can be achieved.
In winter, the heating target temperature is set to a winter target heating temperature that is lower than the normal hot water supply target temperature setting range and the same as the low set mixing temperature. In winter, the hot water in the hot water storage tank 3 cannot normally be heated above the winter target heating temperature only by heating by the exhaust heat of the generator 1, so the location via the dwelling unit of the hot water circulation path R is often Since hot water of low set mixed temperature often flows, in each dwelling unit H, when the hot water supply target temperature is set to the normal hot water supply target temperature setting range, water is mainly supplied by the mixing unit Km by the water heater K. The hot water at the target hot water supply temperature is supplied by heating by the gas burner 37 without being mixed. Therefore, in the water heater K of each dwelling unit, it is possible to prevent the heating operation after mixing with water as much as possible, so that energy saving can be achieved.
[0061]
When the set power generation time period ends and the non-power generation time period starts, the exhaust heat recovery circulation means C1 and the tank water supply means W1 are stopped, and the hot water supply circulation means C2 is brought into the hot water tank hot water circulation state. Execute the water circulation stop hot water circulation operation to be operated.
[0062]
That is, from the control state of the normal hot water tank hot water circulation operation described above, the exhaust heat recovery circulation pump P3 is stopped to stop the exhaust heat recovery circulation means C1, and the tank water supply pump P2 is stopped. Thus, the tank water supply means W1 is stopped, but the hot water supply circulation means C2 is continuously operated in the hot water tank hot water circulation state.
[0063]
As shown in FIG. 2, in the hot water circulation stop operation of hot water storage tank, the circulation of engine cooling water is stopped, and the hot water circulation of hot water tank 3 through the exhaust heat recovery circulation path 10 is stopped. The hot water in the hot water storage tank 3 is stopped by the exhaust heat of 1 and the hot water supply from the water receiving tank 5 to the hot water storage tank 3 is stopped. Circulate around multiple dwelling units H.
[0064]
The above-mentioned auxiliary heating control is executed even during the hot water circulation operation of the hot water tank where water supply is stopped.
During the water supply stop hot water tank hot water circulation operation, the state of the temperature of the hot water flowing through the location passing through the dwelling unit of the hot water supply circulation path R is the same as that during the normal hot water tank hot water circulation operation described above. As in the normal hot water tank hot water circulation operation described above, hot water flowing through the hot water supply circulation path R is used to supply hot water by the hot water heater K, and thus the description thereof is omitted.
[0065]
During the non-power generation time zone, the water level sensor L of the water level sensor L at a time before the water quality maintenance required time that is the sum of the set water quality maintenance operation time and the set water replacement time with respect to the start time of the next set power generation time zone. When the detected water level becomes the set lower limit water level, the storage amount of the main storage unit 3m becomes zero, and the entire amount is stored in the small storage unit 3s, that is, the storage amount of the hot water tank 3 becomes the set lower limit storage amount. The hot water supply circulation means C2 is operated in the water supply state while the stopped state of the exhaust heat recovery circulation means C1 and the tank water supply means W1 is maintained, and the water supply state operation is executed.
[0066]
That is, from the control state of the water supply stop hot water tank hot water circulation operation described above, by stopping the upstream side circulation pump P4 and the downstream side circulation pump P5 and switching the water supply switching three-way valve V4 to the water supply channel connection state, The hot water supply circulation means C2 is operated in a water supply state.
[0067]
As shown in FIG. 3, in the water supply state operation, the hot water circulation in the hot water tank 3 through the exhaust heat recovery circulation path 10 and the hot water supply circulation path R is stopped, and the hot water tank 3 from the water receiving tank 5 is moved to. The water in the water receiving tank 5 is supplied to the hot water supply circulation path R through the water supply switching three-way valve V4 in a state where the water supply is stopped.
[0068]
The above-described auxiliary heating control is executed even during the water supply state operation.
Since the state of the temperature of the hot water flowing through the location passing through the dwelling unit of the hot water supply circulation path R during the water supply state operation is the same as that during the normal hot water tank hot water circulation operation described above, As in the hot water circulation operation, hot water flowing through the hot water supply circulation path R is used to supply hot water by the hot water heater K, and thus the description thereof is omitted.
[0069]
Regardless of whether or not the water supply operation is being executed during the non-power generation time zone, the time before the water quality maintenance time before the start time of the next set power generation time zone, that is, the non-power generation time At the end of the belt setting, the hot water storage tank is maintained in a state in which the exhaust heat recovery circulation means C1 and the tank water supply means W1 are stopped and the hot water supply circulation means C2 is maintained in the water supply state. During the set water quality maintenance operation time, the hot water storage tank water quality maintenance operation is performed to heat the auxiliary heating water heater B so that the hot water of No. 3 is heated to a water quality maintenance temperature capable of maintaining the quality of the hot water. To do.
[0070]
That is, when the water supply state operation is being executed, the auxiliary heating switching three-way valve V5 is switched from the control state of the water supply state operation to the auxiliary heating stop state, and the bath hot water circulation switching three-way valve V2 is set to the bath temperature rising state. The hot water storage tank side tank temperature increase switching three-way valve V6 and the hot water heater side tank temperature increase switching three way valve V7 are respectively switched to the tank temperature increase state, and the exhaust heat recovery circulation pump P3 and the tank temperature increase pump P7 are When the water supply state operation is not executed, the upstream side circulation pump P4 and the downstream side circulation pump P5 are stopped from the control state of the water replenishment stop hot water tank hot water circulation operation and the water supply switching three-way valve is operated. V4 is switched to the water supply channel connection state, the auxiliary heating switching three-way valve V5 is switched to the auxiliary heating stop state, the tank hot water circulation switching three-way valve V2 is switched to the tank temperature rising state, and the hot water tank side tank temperature rising switching is performed. Switched-way valve V6 and the water heater side SoNoboru temperature switching three-way valve V7 respectively the SoNoboru-temperature state, as well, to actuate the exhaust heat recovery circulating pump P3 and SoNoboru temperature pump P7.
[0071]
As shown in FIG. 4, in the hot water storage tank water quality maintenance operation, water supply from the water receiving tank 5 to the hot water storage tank 3 is stopped, and the outflow of hot water in the hot water supply circulation path R to the hot water storage tank 3 is prevented. In this state, the water in the water receiving tank 5 is supplied to the hot water supply circulation path R through the water supply switching three-way valve V4 and flows through the hot water supply circulation path R without passing through the auxiliary water heater B. The hot water in the small reservoir 3s is passed through both the first heat exchanger 71 and the second heat exchanger 72 of the auxiliary water heater B and heated, and then returned to the small reservoir 3s through the branch channel 10b. So that it is circulated. In each dwelling unit H, hot water is supplied from the water receiving tank 5 flowing through the hot water supply circulation path R using the water heater K.
Further, during the execution of the hot water tank water quality maintenance operation, the water flows out from the first heat exchanger 71 based on the water quality maintenance temperature, the detected temperature of the small storage portion take-out temperature sensor T5, and the detected water supply amount of the first water supply amount sensor Q1. A feedforward control for adjusting the opening of the gas proportional valve 76 is executed so that the temperature of the hot water becomes the water quality maintenance temperature, and based on the deviation between the temperature detected by the first hot water temperature sensor T1 and the water quality maintenance temperature. Feedback control for finely adjusting the opening of the gas proportional valve 76 is executed.
The hot water in the small reservoir 3s is heated to the water quality maintenance temperature by the hot water tank water quality maintenance operation, and the hot water in the small reservoir 3s is heated by both the first heat exchanger 71 and the second heat exchanger 72. It is possible to shorten the operation time of the hot water tank water quality maintenance operation.
[0072]
When the hot water tank water quality maintenance operation is completed, a water replacement operation is performed in which the hot water supply circulation means C2 is operated in the water replacement state.
That is, from the control state of the hot water tank water quality maintenance operation, the exhaust heat recovery circulation pump P3 and the tank temperature raising pump P7 are stopped, the heating of the hot water in the small storage 3s by the auxiliary water heater B is stopped, and the tank return is stopped. The three-way valve V3 is switched to the tank return state, and this state is continued for the set water replacement time.
[0073]
As shown in FIG. 5, in the water replacement operation, the water in the water receiving tank 5 is supplied to the hot water supply circulation path R through the water supply switching three-way valve V4 and flows through the hot water supply circulation path R without passing through the auxiliary water heater B. Thus, the hot water in the hot water supply circulation path R is replaced with tap water in the water receiving tank 5 over substantially the entire length of the hot water supply circulation path R, and flows into the main reservoir 3m. The quality of the hot water will be maintained. In addition, since the hot water in the hot water supply circulation path R is replaced with the tap water in the water receiving tank 5, the quality of the hot water in the hot water supply circulation path R is further improved by the sterilization action of chlorine contained in the tap water.
Then, as the water replacement operation ends and the next set power generation time period starts, the normal hot water tank hot water circulation operation is executed.
[0074]
In addition, during the non-power generation time zone, the operation control unit U performs the non-power generation time zone heat load as described above based on the detection information of each hot water supply amount sensor Q3 for each dwelling unit and the dwelling unit supply temperature sensor T4. And the stored information of the non-power generation time zone heat load stored in the storage means is rewritten to the newly determined non-power generation time zone heat load heat. The operation control unit U obtains the target storage amount of the operation target cycle based on the non-power generation time zone heat load and the heating target temperature rewritten as described above.
[0075]
Although not shown, the operation panel for instructing various operation commands to the operation control unit U is provided with a maintenance operation command unit for artificially instructing execution of the maintenance operation.
When a maintenance operation is instructed, the operation control unit U stops the exhaust heat recovery circulation means C1 and the tank water supply means W1, and operates the hot water supply circulation means C2 in the water supply state. Execute.
The control operation of the maintenance operation is the same as the above-described water supply state operation, and the flow state of water from the water receiving tank 5 is also the same as the above-described water supply state operation, and thus description thereof is omitted.
This maintenance operation is performed at the time of failure or maintenance of the generator 3 that cannot supply exhaust heat from the generator 3 or at the time of maintenance of the hot water storage tank 3 that cannot store hot water in the hot water storage tank 3. It is possible to supply hot water to each dwelling unit H through the hot water supply circulation path R at the time of maintenance or maintenance or during maintenance of the hot water storage tank 3.
[0076]
Next, an operation pattern with the passage of time of the cogeneration system configured as described above will be described.
FIG. 7 shows an example of an operation pattern in winter, and FIG. 8 shows an example of an operation pattern in summer. In the set power generation time period from 14:00 to 23:00 in the winter and from 18:00 to 24:00 in the summer, the generator 1 is operated and the normal hot water tank hot water circulation operation is executed. 7 and 8, the operating state of the generator 1 is shown by the fact that exhaust heat is generated from the generator 1. During the execution of the normal hot water tank hot water circulation operation, the storage amount of the hot water tank 3 is maintained at the target storage amount, the temperature of the hot water in the hot water tank 3 becomes a success, and the temperature of the hot water flowing through the hot water supply circulation path R is the target heating. When it becomes lower than the temperature, the auxiliary water heater B is heated so as to reach the target heating temperature.
As the set power generation time period ends, the generator 1 is stopped and the water replenishment stop hot water tank hot / cold water circulation operation is executed. As described above, when the storage amount of the hot water tank 3 becomes equal to or less than the set lower limit storage amount at a time before the water quality maintenance required time with respect to the start time of the next set power generation time zone, the water supply state operation is executed. During the execution of the water supply stop hot water tank hot water circulation operation and the water supply state operation, when the temperature of the hot water flowing through the hot water supply circulation path R becomes lower than the target heating temperature, the auxiliary water heater B is set to the target heating temperature. Heated. In FIG. 8, until the water quality maintenance required time is before the start time of the next set power generation time zone, the storage amount of the hot water tank 3 is maintained in a state larger than the set lower limit storage amount, and the water supply state operation is not executed. Show driving pattern,
Subsequently, the hot water storage tank water quality maintenance operation is executed when the time before the water quality maintenance required time comes before the start time of the next set power generation time zone. By the hot water tank water quality maintenance operation, the hot water in the hot water tank 3 is heated to the water quality maintenance temperature.
Subsequently, when the hot water tank water quality maintenance operation is completed, a water replacement operation is performed. By this water replacement operation, the hot water in the hot water supply circulation path R is replaced with the water in the water receiving tank 5 over substantially the entire length thereof.
[0077]
Hereinafter, the second and third embodiments of the present invention will be described, but the same components as those of the first embodiment and the components having the same actions are denoted by the same reference numerals in order to avoid redundant description. The description is omitted, and a configuration different from the first embodiment will be mainly described.
[0078]
[Second Embodiment]
The second embodiment will be described below.
As shown in FIG. 9, in the second embodiment, the configuration of the cogeneration system is the same as that of the first embodiment, and the control operation of the operation control unit U is the water replacement operation in the first embodiment. Instead, the circulation path water quality maintenance operation for heating the auxiliary water heater B is performed so that the hot water in the hot water circulation path R is heated to a water quality maintenance temperature capable of maintaining the quality of the hot water. Otherwise, the second embodiment is the same as the first embodiment.
[0079]
That is, in the circulation path water quality maintenance operation, after the hot water tank water quality maintenance operation, hot water circulating through the hot water circulation path R is heated to the water quality maintenance temperature by the auxiliary water heater B, and the hot water circulation means C2 is operated. The hot water tank is operated in a hot water circulation state.
That is, from the control state of the hot water tank water quality maintenance operation, the exhaust heat recovery circulation pump P3 and the tank temperature raising pump P7 are stopped, the heating of the hot water in the small storage 3s by the auxiliary water heater B is stopped, and the water supply switching three-way The valve V4 is switched to the water supply channel shut-off state, the auxiliary heating switching three-way valve V5 and the water heater side tank temperature increase switching three-way valve V7 are respectively switched to the auxiliary heating state, and the tank return stop three-way valve V3 is switched to the tank returning state. The state is continued for the set water replacement time.
Further, the temperature of the hot water flowing out from the first heat exchanger 71 becomes the water quality maintenance temperature based on the water quality maintenance temperature, the detection temperature of the hot water tank discharge temperature sensor T3, and the detection water supply amount of the first water supply amount sensor Q1. The feed forward control for adjusting the opening degree of the gas proportional valve 76 is executed, and the opening degree of the gas proportional valve 76 is finely adjusted based on the deviation between the detected temperature of the first hot water temperature sensor T1 and the water quality maintenance temperature. Execute feedback control.
[0080]
As shown in FIG. 9, in the circulation path water quality maintenance operation, the hot water taken out from the small storage portion 3 s in the state where the supply of water from the water receiving tank 5 to the hot water storage tank 3 is stopped is the auxiliary water heater B. In the state heated to the water quality maintenance temperature, the hot water circulation path R is passed through and returned to the main storage portion 3m, so that hot water having a water quality maintenance temperature flows through substantially the entire length of the hot water circulation path R. It will be.
The circulation path water quality maintenance operation is performed after the hot water tank water quality maintenance operation, so that the hot water that is at a substantially water quality maintenance temperature after the hot water tank water quality maintenance operation is supplied to the auxiliary water heater B at the water quality maintenance temperature. Therefore, the energy consumption can be reduced.
Since the operation time of the hot water tank water quality maintenance operation is short, even if hot water flowing through the hot water supply circulation path R is used in each dwelling unit H, the small storage section is sufficiently small to impede hot water circulation. The amount of storage for 3s will not decrease.
[0081]
[Third Embodiment]
Hereinafter, a third embodiment will be described.
As shown in FIG. 10, in the third embodiment, the configuration of the cogeneration system is the same as that of the first embodiment except that the configurations of the hot water tank 3 and the exhaust heat recovery circulation means C1 are different.
That is, similar to the first embodiment, the hot water storage tank 3 is configured to include a main storage portion 3m and a small storage portion 3s having a smaller cross-sectional area than the main storage portion 3m. The specific configuration of the small reservoir 3s is different from that of the first embodiment.
The hot water storage tank 3 is configured as an open type by a substantially rectangular parallelepiped box-shaped tank forming member having an open top, and a recess is formed by recessing a part of the bottom of the tank forming member. A storage portion 3s is formed, and a portion other than the concave portion in the tank forming member is set as the main storage portion 3m.
The water level sensor L is provided so as to measure the water level from the main reservoir 3m to the small reservoir 3s, and the tank circulation path 4 takes hot water from the bottom of the small reservoir 3s and corresponds to the upper side of the small reservoir 3s. It is provided so as to return to the upper part of the main reservoir 3m.
[0082]
The waste heat recovery circulation means C1 omits the branch path 10b and the tank hot water circulation switching three-way valve V2 provided in the first embodiment, and recovers the hot water taken out from the bottom of the small storage part 3s of the hot water storage tank 3 by exhaust heat recovery. The exhaust heat recovery circulation path 10 piped to return from the upper part of the main reservoir 3m via the heat exchanger 2 and the exhaust heat recovery circulation pump P3 provided in the exhaust heat recovery circulation path 10 And is configured.
[0083]
Next, the control operation of the operation control unit U will be described.
Since power supply control is the same as that in the first embodiment, the description thereof is omitted.
In hot water supply control, normal hot water tank hot water circulation operation, hot water supply stop hot water tank hot water circulation operation, water supply state operation, hot water tank water quality maintenance operation and water replacement operation are automatically executed in the same manner as in the first embodiment. The maintenance operation is executed based on a command from the maintenance operation command unit of the operation panel. The control operation in each operation is the same as that of the first embodiment except that there is no control operation of the tank hot water circulation switching three-way valve V2, and thus the description thereof is omitted.
In addition, the flow forms of the engine cooling water, the hot water in the hot water storage tank 3 and the water in the water receiving tank 5 in each operation are the same as in the first embodiment except for the flow forms in the hot water tank water quality maintenance operation. The difference from the first embodiment in the flow mode of the tank water quality maintenance operation will be described, and the description of the flow mode of other operations will be omitted.
That is, in the first embodiment, the hot water in the small reservoir 3s of the hot water tank 3 is heated by the auxiliary water heater B and then returned directly to the small reservoir 3s through the branch path 10b of the exhaust heat recovery circulation path 10. On the other hand, in 3rd Embodiment, after the hot water of the small storage part 3s of the hot water storage tank 3 is heated by the auxiliary water heater B, the small storage is performed from the upper part of the main storage part 3m through the exhaust heat recovery circulation path 10. The flow form of the hot water tank water quality maintenance operation in the third embodiment is different from that in the first embodiment in that it is returned to the section 3s.
[0084]
[Another embodiment]
Next, another embodiment will be described.
In the above embodiment, the heat load detecting means is configured to obtain the total amount of hot water supplied to the plurality of dwelling units H through the hot water supply circulation means C2 as the non-power generation time zone heat load as the heat generation time zone. Although illustrated about the case where it does, you may comprise so that the total flow volume of the hot water supplied to the some dwelling unit H through the hot water supply circulation means C2 may be calculated | required as the said non-power generation time zone heat load during the non-power generation time zone. In this case, the total flow rate of hot water in the cycle before the operation target cycle determined as the non-power generation time zone heat load is set as the target storage amount of the operation target cycle.
The specific setting method can be changed in setting the target storage amount of the operation target cycle based on the non-power generation time zone thermal load detected by the thermal load detection means. For example, the non-power generation time zone thermal load detected every day is averaged every month, the average value is stored in the storage unit in association with the month, and the target storage amount of the operation target cycle is based on the stored information May be set.
[0085]
In the above-described embodiment, the case where the target storage amount of the operation target cycle is changed and set based on the non-power generation time zone thermal load detected by the thermal load detection unit is illustrated, but a cogeneration system is installed. In view of the heat load of the target area or apartment house, the target storage amount is set in advance in association with the month or in association with the month and day of the week, and is stored in the storage unit, based on the stored information Thus, the target storage amount of the operation target cycle may be fixedly set for each month or for each day of the week.
[0086]
In the above embodiment, the hot water supply circulation path R forms a hot water tank bypass path that passes through the plurality of dwelling units H in a state of bypassing the hot water tank 3 using the tank via circulation path 4 and the tank bypass path 12. However, instead of this, the circulation path R for hot water supply uses only the circulation path 4 via the tank, and uses a plurality of dwelling units H included in the apartment house with hot water taken out from the small storage section 3s of the hot water storage tank 3. You may comprise so that the path | route which returns to the upper part of the main hot water storage part 3m via may be formed.
[0087]
In said embodiment, although illustrated about the case where the hot water tank 3 was comprised including the main storage part 3m and the small storage part 3s whose cross-sectional area is smaller than the main storage part 3m, only one storage part is comprised. You may comprise so that it may be provided.
[0088]
In the above-described embodiment, the case where the auxiliary water heater B that serves both as the auxiliary heating means B1 for the hot water tank and the auxiliary heating means B2 for the circulation path is illustrated, but the auxiliary heating means B1 for the hot water tank and the auxiliary heating for the circulation path are illustrated. The means B2 may be provided separately.
In this case, during the hot water tank water quality maintenance operation, the water supply state operation is executed in parallel while heating the hot water flowing through the hot water supply circulation path R to the target heating temperature by the circulation path auxiliary heating means B2. Therefore, hot water at the target heating temperature can be supplied to each dwelling unit H even during execution of the hot water tank water quality maintenance operation.
The hot water tank auxiliary heating means B1 and the circulation path auxiliary heating means B2 may be omitted. However, when the hot water tank auxiliary heating means B1 and the circulation path auxiliary heating means B2 are omitted, the hot water tank water quality maintenance operation and the circulation path water quality maintenance operation cannot be executed.
[0089]
The structure of the water heater K provided in each dwelling unit H can be changed. For example, when the circulating hot water temperature is lower than the hot water supply target temperature, the mixing operation of the mixing unit Km is controlled so that the set mixed temperature is set to be lower than the target hot water temperature by a set temperature difference or more, In addition, the heating operation of the heating unit Kh is controlled so that the hot water supply temperature becomes the target hot water supply temperature. When the circulating hot water temperature is equal to or higher than the hot water supply target temperature, the heating operation of the heating unit Kh is stopped. You may comprise so that the mixing operation | movement of the mixing part Km may be controlled so that temperature may turn into hot water supply target temperature.
[0090]
In said embodiment, although illustrated about the case where the water-receiving tank 5 is used as a water supply source, you may use water supply itself as a water supply source. In this case, a water pipe is connected to each of the tank water supply channel 9 and the circulation water supply channel 14.
[0091]
In the third embodiment, as in the second embodiment, the circulation path water quality maintenance operation may be executed instead of the water replacement operation.
[0092]
When the power generation means is constituted by an engine-driven rotary generator 1 driven by an engine such as a gas engine as in the above embodiment, the generator is supplied to the heat exchanger 2 for exhaust heat recovery The exhaust heat of 1 may be configured to supply engine exhaust gas or supply both engine coolant and exhaust gas in addition to the engine coolant exemplified in the above embodiment. In the case where the power generation means is constituted by the engine-driven rotary generator 1, the engine includes various kinds of LP gas, oil, gasoline, etc., in addition to those using city gas exemplified in the above embodiment as fuel. It is possible to use those using the following fuel.
Further, the power generation means may be constituted by a gas turbine driven rotary generator driven by a gas turbine in addition to the engine driven rotary generator 1 as exemplified in the above embodiment. good. When the power generation means is configured by a gas turbine-driven rotary generator, the exhaust heat recovery heat exchanger 2 is configured to supply the exhaust gas of the gas turbine as exhaust heat.
Further, the power generation means is not limited to the rotary generator as described above, and can be constituted by various fuel cells, for example. When the power generation means is configured by a fuel cell, the exhaust heat recovery heat exchanger 2 is configured to supply fuel cell cooling water as exhaust heat.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a cogeneration system according to a first embodiment and a hot water flow pattern in a normal hot water tank hot water circulating operation.
FIG. 2 is a diagram showing a hot water flow pattern in a hot water circulation operation of a hot water supply stop hot water tank in the cogeneration system according to the first embodiment.
FIG. 3 is a view showing a hot water flow pattern in a water supply state operation and a maintenance operation of the cogeneration system according to the first embodiment.
FIG. 4 is a view showing a hot water flow pattern in hot water tank water quality maintenance operation of the cogeneration system according to the first embodiment.
FIG. 5 is a view showing a hot water flow pattern in the water replacement operation of the cogeneration system according to the first embodiment.
FIG. 6 is a diagram showing a configuration of a water heater of the cogeneration system according to the embodiment.
FIG. 7 is a diagram showing an operation pattern of the cogeneration system according to the first embodiment.
FIG. 8 is a diagram showing an operation pattern of the cogeneration system according to the first embodiment.
FIG. 9 is a diagram showing a configuration of a cogeneration system according to a second embodiment and a hot water flow pattern in a circulation path water quality maintenance operation.
FIG. 10 is a diagram showing a configuration of a cogeneration system according to a third embodiment.
FIG. 11 is a diagram showing the configuration of a conventional cogeneration system
[Explanation of symbols]
1 Power generation means
2 Heat exchanger for exhaust heat recovery
3 Hot water tank
3m main reservoir
3s small reservoir
5 Water supply sources
B1 Auxiliary heating means for hot water storage tanks
B2 Auxiliary heating means for circulation path
C1 Circulation means for exhaust heat recovery
C2 Hot water circulation means
H dwelling unit
K water heater
R Hot water circulation route
U Operation control means
W1 tank water supply means
W2 Water supply means for circulation

Claims

Power generation means for generating power for a region or apartment house as a power supply target, a heat exchanger for exhaust heat recovery to which exhaust heat from the power generation means is supplied, and hot water for a plurality of dwelling units included in the area or apartment house Hot water storage tank to store, tank water supply means for supplying water to the hot water storage tank, waste heat recovery circulation means for circulating hot water between the exhaust heat recovery heat exchanger and the hot water storage tank, the hot water storage tank and the plurality of dwelling units A hot water supply circulation means for circulating hot water in a hot water supply circulation path, and a cogeneration system provided with an operation control means for controlling operation,
The hot water tank is configured as an open type with an open top,
The operation control means is
The power generation means and the exhaust heat recovery circulation means are operated in a set power generation time zone set as a part of a day, and the power generation is performed in a non-power generation time zone other than the set power generation time zone. And the exhaust heat recovery circulation means are stopped, and
Said consumption or substantially consumable accumulated amount in the non-power generation time period as a target storage amount of the hot water storage tank is set, operating the tank water supply means so as to store a target storage amount of Waso at the set power generation time period In the non-power generation time zone, the tank water supply means is stopped , and in the set power generation time zone and the non-power generation time zone, the hot water circulation is performed to consume hot water stored in the hot water storage tank. A cogeneration system configured to control operation in the form of actuating means.

Each of the plurality of dwelling units is provided with a water heater that supplies hot water to the hot water demand section using hot water supplied through the circulating means for hot water supply,
A circulation water supply means for supplying water from a water supply source to the hot water supply circulation path is provided;
The hot water circulation means is configured to circulate hot water in the hot water storage tank through the hot water circulation path, stop hot water circulation in the hot water storage tank, and stop the circulation of hot water in the hot water tank to supply the hot water in the circulation water supply means. It is configured to be switchable between the water supply state for supplying water to the circulation path,
The operation control means is configured to switch the hot water supply circulation means from the hot water tank hot water circulation state to the water supply state when the storage amount of the hot water tank reaches a set lower limit storage amount in the non-power generation time zone. The cogeneration system according to claim 1.

Auxiliary heating means for hot water tank for heating the hot water in the hot water tank is provided,
In the non-power generation time zone, the operation control means is configured to perform the non-power generation even when the storage amount of the hot water storage tank becomes the set lower limit storage amount, or even if the storage amount of the hot water storage tank does not become the set lower limit storage amount or less. At the end of setting in the time zone, the hot water circulation means is switched from the hot water tank hot water circulation state to the water supply state, and the hot water in the hot water tank is maintained at a water quality maintenance temperature capable of maintaining the quality of the hot water. The cogeneration system according to claim 2, wherein the cogeneration system is configured to perform a hot water tank water quality maintenance operation for heating the hot water tank auxiliary heating means so as to heat the hot water tank.

The hot water tank is configured to include a main storage part and a small storage part having a smaller cross-sectional area than the main storage part,
When the main storage portion and the small storage portion communicate with each other, and the storage amount of the hot water storage tank is equal to or less than the set lower limit storage amount, the entire amount is stored in the small storage portion, and the storage amount of the hot water storage tank is the setting 4. The apparatus is provided such that when the amount is larger than a lower limit storage amount, the set lower limit storage amount is stored in the small storage portion and a portion exceeding the set lower limit storage amount is stored in the main storage portion. Cogeneration system.

The hot water circulation means stops the hot water circulation in the hot water storage tank, and hot water in the hot water circulation path is supplied by the circulation water supply means over the entire length or substantially the entire length of the hot water circulation path. It is configured to be freely switchable to a water replacement state that replaces with water,
The operation control means stops the operation of the hot water supply circulation means in the hot water tank hot water circulation state until the next time the hot water supply circulation means is operated in the hot water tank hot water circulation state. The cogeneration system according to any one of claims 2 to 4, wherein the cogeneration system is configured to execute a water replacement operation for operating the hot water supply circulation means in the water replacement state.

An auxiliary heating means for circulation path for heating hot water in the circulation path for hot water supply is provided,
The operation control means stops the operation of the hot water supply circulation means in the hot water tank hot water circulation state until the next time the hot water supply circulation means is operated in the hot water tank hot water circulation state. In addition, the circulation path water quality maintenance operation is performed to heat the circulation path auxiliary heating means so as to heat the hot water in the hot water circulation path to a water quality maintenance temperature capable of maintaining the quality of the hot water. The cogeneration system according to any one of claims 2 to 5, wherein the cogeneration system is configured to.