JP4485616B2

JP4485616B2 - Cogeneration equipment

Info

Publication number: JP4485616B2
Application number: JP12868799A
Authority: JP
Inventors: 伸岩田
Original assignee: Osaka Gas Co Ltd
Current assignee: Osaka Gas Co Ltd
Priority date: 1999-05-10
Filing date: 1999-05-10
Publication date: 2010-06-23
Anticipated expiration: 2019-05-10
Also published as: JP2000320401A

Description

【０００１】
【発明の属する技術分野】
本発明はコージェネレーション装置に関し、詳しくは、電力消費機器への送電ラインに外部商用電源からの受電ラインと発電手段の電力出力ラインを接続し、発電に伴い発電手段で生じる排熱を回収して、その回収熱により貯湯槽内の水を加熱する排熱利用加熱手段を設けるコージェネレーション装置に関する。
【０００２】
【従来の技術】
この種のコージェンレーション装置では、電力消費機器の需要電力の低下で発電手段の発電出力が電力消費機器の需要電力を上回る状態になって、外部商用電源の側への電力の逆潮流が生じる状況になると、外部商用電源からの受電ラインを切断することで、外部商用電源の側への電力の逆潮流を防止するが、外部商用電源からの受電ラインを切断すると、その切断が発電手段に悪影響を及ぼす（例えばエンジン駆動発電機ではエンジン回転数が急激な負荷低下のために急上昇する）ことで、発電手段の耐用年数の大幅な低下を招く問題がある。
【０００３】
また、このような事態を防止するには、電力消費機器の需要電力の変動に対し発電出力が電力消費機器の需要電力を上回る状況が頻繁に生じることの無いように、定格の発電出力が小さい小能力の発電手段を用いることが必要になり、そのことでコージェネレーション装置としての電力の自給率が低く制限されてしまう問題もある。
【０００４】
これらのことから、従来、この種のコージェンレーション装置では、発電手段の発電出力を電力消費機器の需要電力の変動に応じ調整（例えばエンジン駆動発電機ではエンジン出力を調整）することで、外部商用電源の側への電力の逆潮流を防止して、外部商用電源からの受電ラインの切断に至る事態を回避するようにしていた。
【０００５】
【発明が解決しようとする課題】
しかし、電力消費機器の需要電力の変動に応じて発電手段の発電出力を調整する方式にしても、頻繁な出力調整のために発電手段の耐用年数が低下する問題があり、また、図６に実線で示す如く、電力消費機器の需要電力Ｗｚの急激な低下に対し発電出力Ｗｇ´の調整が追従できずに外部商用電源の側への電力の逆潮流を招いて外部商用電源からの受電ラインの切断に至る危険性があることから、破線で示す如く発電出力Ｗｇを電力消費機器の需要電力Ｗｚに比べ予め低く制限しておくことが必要になり、このことで、やはりコージェネレーション装置としての電力の自給率が低く制限されてしまう問題があった。
【０００６】
これらの実情に鑑み、本発明の主たる課題は、合理的な改良により、発電手段の耐用年数を長く確保し、また、高い電力自給率を確保しながら、外部商用電源の側への電力の逆潮流を確実に防止する点にある。
【０００７】
【課題を解決するための手段】
〔１〕請求項１に係る発明では、電力消費機器への送電ラインに外部商用電源からの受電ラインと発電手段の電力出力ラインを接続し、
発電に伴い前記発電手段で生じる排熱を回収して、その回収熱により貯湯槽内の水を加熱する排熱利用加熱手段を設けるコージェネレーション装置において、
前記電力消費機器への送電ラインと前記外部商用電源からの受電ラインと前記発電手段の電力出力ラインとの接続系統から分岐送電ラインを通じて電力供給を受ける電気ヒータを設けるとともに、この電気ヒータに対する前記分岐送電ラインからの供給電力を調整するヒータ調整手段を設け、
前記電力消費機器の需要電力と前記発電手段の発電出力とのバランス状態を検出して、その検出結果に基づき、前記発電手段の発電出力が前記電力消費機器の需要電力に対し過剰の状況ではその過剰電力を前記電気ヒータで消費させ、かつ、前記発電手段の発電出力が前記電力消費機器の需要電力に対し不足の状況では前記電気ヒータへの供給電力を所定の最小電力に制限するように前記ヒータ調整手段を制御する逆潮流防止制御手段を設ける。
【０００８】
つまり、この構成では、電力消費機器の需要電力に対し発電手段の発電出力が過剰となる状況が生じると、上記の逆潮流防止制御手段によるヒータ調整手段の制御（すなわち、電気ヒータへの供給電力の調整）により発電電力の過剰分を分岐送電ラインを通じて電気ヒータで消費させ、これにより、外部商用電源の側への電力の逆潮流を防止する。
【０００９】
また、電力消費機器の需要電力に対し発電手段の発電出力が不足となる状況では、上記の逆潮流防止制御手段によるヒータ調整手段の制御により分岐送電ラインからの電気ヒータへの供給電力を所定の最小電力に制限し、これにより、外部商用電源からの受電電力を電気ヒータで不必要に消費することを回避ないし抑制した状態で、電力消費機器の需要電力に対する発電出力の不足分を外部商用電源からの受電電力で賄うようにする。
【００１０】
すなわち、この構成によれば、電力消費機器への送電ラインと外部商用電源からの受電ラインと発電手段の電力出力ラインとの接続系統から電気ヒータに供給して電気ヒータで消費させる電力の調整により外部商用電源の側への電力の逆潮流を防止するから、外部商用電源からの受電ラインの切断を不要にしてその切断に原因する発電手段への悪影響を回避するとともに、発電手段の頻繁な出力調整も抑止ないし不要にすることができ、これにより、発電手段の耐用年数ひいてはコージェネレーション装置の耐用年数を長くすることができる。
【００１１】
また、電力消費機器の需要電力の変動に対し発電出力が電力消費機器の需要電力を上回る状況が頻繁に生じることの無いように、定格発電出力の小さい小能力の発電手段を用いたり、発電出力を電力消費機器の需要電力に比べ予め低く制限した状態で電力消費機器の需要電力の変動に応じ発電出力を調整するといったことも不要になり、これにより、コージェネレーション装置としての電力の自給率も高く確保することができて、コージェネレーション装置の省エネ効果を高めることができる。
【００１２】
そしてまた、電力消費機器の需要電力に対し発電出力が不足となる状況では、電気ヒータへの供給電力を所定の最小電力に制限して、外部商用電源からの受電電力を電気ヒータで不必要に消費することを回避ないし抑制することからも、コージェネレーション装置の省エネ効果を高めることができ、さらに、電力消費機器の需要電力と発電手段の発電出力とのバランス状態の検出結果に基づき電気ヒータへの供給電力を調整することから、電力消費機器の需要電力と発電手段の発電出力とのバランス状態に応じた電気ヒータに対する供給電力の調整を的確にして、上記の如き外部商用電源の側への電力の逆潮流の防止、及び、外部商用電源からの受電電力を電気ヒータで不必要に消費することの回避ないし抑制を確実にすることができる。
【００１３】
〔２〕請求項２に係る発明では、請求項１に係る発明の実施にあたり、前記電気ヒータを前記排熱利用加熱手段とともに前記貯湯槽内の水に対して加熱作用させる構成にする。
【００１４】
この構成によれば、前記電気ヒータの発生熱、すなわち、電力消費機器の需要電力に対する発電電力の過剰分による発生熱を貯湯槽内の水の加熱に回収利用するから、発電手段で生じる排熱を用いて排熱利用加熱手段により貯湯槽内の水を加熱することによるコージェネレーション装置の本来の省エネ効果と相俟って、より高い省エネ効果を得ることができる。
【００１５】
なお、電気ヒータを貯湯槽内の水に対して加熱作用させるには、電気ヒータを貯湯槽内の水に対して直接的に加熱作用させる方式、あるいは、適当な熱媒体を介して電気ヒータを貯湯槽内の水に対し加熱作用させる方式のいずれを採用してもよい。
【００１６】
〔３〕請求項３に係る発明では、請求項１又は２に係る発明の実施にあたり、前記電気ヒータを複数設け、前記ヒータ調整手段を、これら複数の電気ヒータに対する前記分岐送電ラインからの電力供給を選択的に断続して、これら複数の電気ヒータへの総供給電力を調整する構成にする。
【００１７】
この構成によれば、交流電力であるか直流電力であるかを問わず、各電気ヒータへの電力供給を選択的に断続するリレー等の単純なスイッチ構造で前記ヒータ調整手段を構成できるから、電気ヒータへの供給電力の調整面で装置構成を簡易にすることができる。
【００１８】
なお、複数の電気ヒータに互いの定格消費電力が相違する電気ヒータを用いれば、電気ヒータの数を少数にしながらも上記の選択的電力供給により電気ヒータへの総供給電力を多様に調整することができて、外部商用電源の側への電力の逆潮流を防止すること、及び、外部商用電源からの受電電力を電気ヒータで不必要に消費するのを回避ないし抑制することの対応性を高めることができる。
【００１９】
〔４〕請求項４に係る発明では、請求項１〜３のいずれか１項に係る発明の実施にあたり、前記逆潮流防止制御手段を、前記外部商用電源からの受電ラインに付設の電力検出手段により検出する前記外部商用電源からの受電電力に基づき前記電力消費機器の需要電力と前記発電手段の発電出力とのバランス状態を検出する構成にする。
【００２０】
この構成によれば、例えば電力消費機器の需要電力及び発電手段の発電出力（発電電力）を検出して、それらの差を演算する形態で電力消費機器の需要電力と発電手段の発電出力とのバランス状態を検出するに比べ、それらのバランス状態を外部商用電源からの受電電力の直接的検出だけで簡易に検出することができ、これにより、装置構成を簡略にすることができる。
【００２１】
〔５〕請求項５に係る発明では、請求項１〜４のいずれか１項に係る発明の実施にあたり、前記発電手段を一定の発電出力で運転する構成にする。
【００２２】
この構成によれば、発電手段の出力調整に原因する耐用年数の低下をより一層効果的に防止できて、発電手段の耐用年数ひいてはコージェネレーション装置の耐用年数をさらに効果的に長くすることができる。
【００２３】
【発明の実施の形態】
図１はエンジン駆動発電機を用いたコージェネレーション装置を示し、発電手段１として発電機１ａとこの発電機１ａを駆動するガスエンジン１ｂを設け、この発電手段１の電力出力ライン２と外部商用電源３からの受電ライン４とを電力消費機器５への送電ライン６に接続してある。
【００２４】
７は給湯用の貯湯槽、８は発電に伴い発電手段１で生じる排熱を回収してその回収熱により貯湯槽７内の水を加熱する排熱利用加熱手段であり、この排熱利用加熱手段８は、具体的には、貯湯槽７内に設けた水加熱用の熱交換器８ａと、エンジン１ｂの排熱（エンジン排ガスの保有熱やエンジン冷却での奪取熱）により加熱した熱媒Ｒを熱交換器８ａに循環させる循環路８ｂとで構成してある。
【００２５】
また、貯湯槽７内には上記の熱交換器８ａとともに貯湯槽７内の水に対して加熱作用させる電気ヒータ９を設けてあり、この電気ヒータ９へは発電手段１の電力出力ライン２から分岐した分岐送電ライン１０を通じて電力供給を行うようにしてある。
【００２６】
１１は電力消費機器５の需要電力Ｗｚと発電手段１の発電出力Ｗｇとのバランス状態に応じて電気ヒータ９への供給電力Ｗｈを調整する制御ユニットであり、この制御ユニット１１には、電気ヒータ９への供給電力Ｗｈを調整するヒータ調整手段として電気ヒータ９への分岐送電ライン１０に介装するサイリスタ等のゲート素子１２と、外部商用電源３からの受電電力Ｗｉｎ（買電電力）を検出する電力検出手段として外部商用電源３からの受電ライン４に付設する電力検出器１３と、逆潮流防止用の制御手段として電力検出器１３の検出情報に基づきゲート素子１２を制御する制御器１４とを装備してある。
【００２７】
そして、この制御器１４は、Ｗｉｎ＝Ｗｚ＋Ｗｈ−Ｗｇとなる電力関係において、電力検出器１３により検出される外部商用電源３からの受電電力Ｗｉｎが０未満に低下する傾向を示すと、外部商用電源３からの受電電力Ｗｉｎを０に保つように電気ヒータ９への供給電力Ｗｈを増加側に調整し、一方、電気ヒータ９への供給電力Ｗｈが調整下限のＷｈ＝所定の正の最小値まで未だ減少していない状況で、電力検出器１３により検出される外部商用電源３からの受電電力Ｗｉｎが増加傾向を示すと、電気ヒータ９への供給電力Ｗｈを減少側に調整するように、ゲート素子１２を制御（例えば位相角制御）する構成にしてあり、これにより、発電手段１の発電出力Ｗｇが電力消費機器５の需要電力Ｗｚに対し過剰の状況では、その過剰電力（＝Ｗｇ−Ｗｚ）を電気ヒータ９で消費させて、外部商用電源３の側への電力の逆潮流を防止し、また、発電手段１の発電出力Ｗｇが電力消費機器５の需要電力Ｗｚに対し不足の状況では電気ヒータ９への供給電力Ｗｈを所定の最小電力に制限して、外部商用電源３からの受電電力Ｗｉｎを電気ヒータ９で不必要に消費することを抑止する。
【００２８】
発電手段１は、図２において破線で示す如く、その運転開始から貯湯槽７内の水が所定温度に上昇するまでの間、定格出力で一定出力運転するようにしてあり、この定格運転において同図２に示す如く、発電手段１の発電出力Ｗｇが電力消費機器５の需要電力Ｗｚを上回る状況では、上記制御器１４による電気ヒータ９への供給電力Ｗｈ（換言すれば電気ヒータ９の消費電力）の調整により発電手段１の発電出力Ｗｇの過剰分（＝Ｗｇ−Ｗｚ）が電気ヒータ９で消費されて貯湯槽７内の水の加熱に利用され、逆に、電力消費機器５の需要電力Ｗｚが発電手段１の発電出力Ｗｇを上回る状況では、上記制御器１４による電気ヒータ９への供給電力Ｗｈの調整により電気ヒータ９への電力供給が断たれた状態で電力不足分（＝Ｗｚ−Ｗｇ）が外部商用電源３からの受電（買電）により賄われる。
【００２９】
〔別実施形態〕
次に別の実施形態を列記する。
【００３０】
前述の実施形態では、ヒータ調整手段をサイリスタ等のゲート素子１２で構成したが、電気ヒータ９への供給電力Ｗｈを調整するヒータ調整手段には種々の形式のものを採用でき、例えば図３に示す如く、複数の電気ヒータ９ａ〜９ｅを設ける構成にして、各電気ヒータ９ａ〜９ｅへの分岐送電ライン１０からの電力供給を選択的に断続するリレー等のスイッチ１２ａ〜１２ｅによりヒータ調整手段を構成し、これらスイッチ１２ａ〜１２ｅを電力検出器１３による検出受電電力Ｗｉｎに基づき制御器１４により選択的に開閉して複数の電気ヒータ９ａ〜９ｅへの総供給電力Ｗｈを調整するようにしてもよい。
【００３１】
なお、図３に示す装置構成において複数の電気ヒータ９ａ〜９ｅに互いの定格消費電力が相違する電気ヒータを用いれば、電気ヒータ９ａ〜９ｅの数を少数にしながらも、それら電気ヒータ９ａ〜９ｅに対する選択的電力供給により電気ヒータ９ａ〜９ｅへの総供給電力Ｗｈを多様に調整することができる。
【００３２】
図３において、１５は発電手段１に燃料電池などの直流発電手段を用いることに対し、その直流の発電出力Ｗｇを交流に変換するインバータであり、また、図３に示す装置構成において、発電手段１に交流発電手段を用いる場合には図中破線で示す如き整流器１６をインバータ１５の上流側に介装する。
【００３３】
電気ヒータ９を排熱利用加熱手段８とともに貯湯槽７内の水に対して加熱作用させる場合、前述の実施形態の如く電気ヒータ９を貯湯槽７内の水に対し直接に加熱作用させるに代え、図４に示す如く、水加熱用の熱交換器８ａと発電手段１との間で循環させる熱媒Ｒに対して電気ヒータ９を加熱作用させる構成にしてもよい。
【００３４】
電気ヒータ９，９ａ〜９ｅの発生熱は貯湯槽７内の水の加熱に限らず種々の温熱用途に有効利用することができ、また場合によっては、図５に示す如く電気ヒータ９の発生熱を外部へ放熱するようにしてもよい。
【００３５】
前述の実施形態では電気ヒータ９への分岐送電ライン１０を発電手段１の電力出力ライン２から分岐したが、これに限らず、電気ヒータ９への分岐送電ライン１０は、発電手段１の電力出力ライン２と外部商用電源３からの受電ライン４と電力消費機器５への送電ライン６との接続系統におけるいずれの箇所から分岐してもよい。
【００３６】
前述の実施形態では、外部商用電源３からの受電ライン４に付設の電力検出手段１３により外部商用電源３からの受電電力Ｗｉｎを検出して、その検出受電電力Ｗｉｎに基づき電力消費機器５の需要電力Ｗｚと発電手段１の発電出力Ｗｇとのバランス状態を検出するようにしたが、電力消費機器５の需要電力Ｗｚと発電手段１の発電出力Ｗｇとのバランス状態を検出する具体的検出手段は種々の構成変更が可能であり、例えば、電力消費機器５の需要電力Ｗｚと発電手段１の発電出力Ｗｇとの差を演算する形態で両者のバランス状態を検出するようにしてもよい。
【００３７】
発電手段１は、エンジンをもって発電機を駆動するエンジン駆動式のものや燃料電池、あるいは、ガスタービン形式のものなど、発電に伴い排熱を生じるものであればどのような形式のものであってもよい。
【００３８】
また、前述の実施形態では、発電手段１を一定出力で運転するようにしたが、発電手段１を電力消費機器５の需要電力Ｗｚの変動に応じ段階的に又は緩やかに出力調整する構成にして、その段階的ないし緩やかな出力調整で電力消費機器５の需要電力Ｗｚの変動に対し追従し切れずに生じる発電出力Ｗｇの過剰分を電気ヒータ９で消費するようにしてもよい。
【図面の簡単な説明】
【図１】実施形態を示すコージェネレーション装置の装置構成図
【図２】装置の運転形態を示すグラフ
【図３】別実施形態を示す装置構成図
【図４】他の別実施形態を示す装置構成図
【図５】他の別実施形態を示す装置構成図
【図６】従来の発電出力調整形態を示すグラフ
【符号の説明】
１発電手段
２電力出力ライン
３外部商用電源
４受電ライン
５電力消費機器
６送電ライン
７貯湯槽
８排熱利用加熱手段
９電気ヒータ
９ａ〜９ｅ電気ヒータ
１０分岐送電ライン
１２ヒータ調整手段
１２ａ〜１２ｅヒータ調整手段
１３電力検出手段
１４逆潮流防止制御手段
Ｗｇ発電手段の発電出力
Ｗｈ電気ヒータへの供給電力
Ｗｉｎ外部商用電源からの受電電力
Ｗｚ電力消費機器の需要電力[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cogeneration apparatus, and more specifically, a power receiving line from an external commercial power source and a power output line of a power generation means are connected to a power transmission line to a power consuming device, and exhaust heat generated by the power generation means accompanying power generation is recovered. Further, the present invention relates to a cogeneration apparatus provided with exhaust heat utilization heating means for heating water in a hot water tank with the recovered heat.
[0002]
[Prior art]
In this type of coordinating device, the power generation output of the power generation means exceeds the power demand of the power consuming device due to a decrease in the power demand of the power consuming device, and a reverse power flow to the external commercial power source occurs. When the situation arises, the power supply line from the external commercial power supply is disconnected to prevent the reverse power flow to the external commercial power supply side.However, when the power reception line from the external commercial power supply is disconnected, the disconnection becomes a power generation means. There is a problem that the service life of the power generation means is significantly reduced due to adverse effects (for example, in an engine-driven generator, the engine speed rapidly increases due to a rapid load drop).
[0003]
In order to prevent such a situation, the rated power output is small so that the situation where the power output exceeds the power demand of the power consuming device does not occur frequently due to fluctuations in the power demand of the power consuming device. It is necessary to use a small-capacity power generation means, which causes a problem that the self-sufficiency rate of power as a cogeneration device is limited to be low.
[0004]
For these reasons, conventionally, in this type of cogenation device, the power generation output of the power generation means is adjusted according to fluctuations in the demand power of the power consuming equipment (for example, the engine output is adjusted in the engine-driven generator). The reverse power flow to the commercial power source side is prevented to avoid a situation in which the power receiving line is disconnected from the external commercial power source.
[0005]
[Problems to be solved by the invention]
However, even if the method of adjusting the power generation output of the power generation means according to the fluctuation of the demand power of the power consuming equipment, there is a problem that the useful life of the power generation means decreases due to frequent output adjustment, and FIG. As indicated by the solid line, the adjustment of the power generation output Wg ′ cannot follow the sudden decrease in the demand power Wz of the power consuming equipment, causing a reverse power flow to the external commercial power supply side and receiving the power line from the external commercial power supply. Therefore, it is necessary to limit the power generation output Wg to be lower than the demand power Wz of the power consuming equipment in advance, as shown by the broken line. There was a problem that the self-sufficiency rate of power was limited to a low level.
[0006]
In view of these circumstances, the main problem of the present invention is that, by rational improvement, the service life of the power generation means is ensured for a long time, and a high power self-sufficiency ratio is ensured while the power to the external commercial power source is reversed. It is in the point to prevent the current.
[0007]
[Means for Solving the Problems]
[1] In the invention according to claim 1, the power receiving line from the external commercial power source and the power output line of the power generation means are connected to the power transmission line to the power consuming device,
In the cogeneration system that provides exhaust heat utilization heating means for recovering the exhaust heat generated by the power generation means accompanying power generation and heating the water in the hot water storage tank with the recovered heat,
An electric heater that receives power supply through a branch transmission line from a connection system of a power transmission line to the power consuming device, a power reception line from the external commercial power source, and a power output line of the power generation means is provided, and the branch to the electric heater Provide heater adjustment means to adjust the power supplied from the power transmission line,
Detecting a balance state between the demand power of the power consuming device and the power generation output of the power generation means, and based on the detection result, in a situation where the power generation output of the power generation means is excessive with respect to the power demand of the power consumption device In a situation where excess electric power is consumed by the electric heater, and the power generation output of the power generation means is insufficient with respect to the power demand of the power consuming device, the power supplied to the electric heater is limited to a predetermined minimum power. Reverse power flow prevention control means for controlling the heater adjustment means is provided.
[0008]
That is, in this configuration, when a situation occurs in which the power generation output of the power generation means becomes excessive with respect to the demand power of the power consuming equipment, the control of the heater adjustment means by the reverse power flow prevention control means (that is, the power supplied to the electric heater) Adjustment), the excess generated power is consumed by the electric heater through the branch transmission line, thereby preventing the reverse power flow to the external commercial power source.
[0009]
Further, in a situation where power generation output of the generator means to the power demand of the power consuming device is insufficient, a predetermined electric power supplied to the branch transmission line or these electric heater under the control of the heater adjusting means by reverse power flow prevention control means of the Therefore, the shortage of power generation output with respect to the power demand of the power consuming equipment can be reduced while avoiding or suppressing unnecessary consumption of the power received from the external commercial power supply by the electric heater. Cover with power received from the power supply.
[0010]
That is, according to this configuration, by adjusting the electric power supplied to the electric heater from the connection system of the power transmission line to the power consuming device, the power receiving line from the external commercial power source, and the power output line of the power generation means and consumed by the electric heater. Since the reverse power flow to the external commercial power source is prevented, it is not necessary to disconnect the power receiving line from the external commercial power source, thereby avoiding the negative effects on the power generating means caused by the disconnection and the frequent output of the power generating means. Adjustment can also be suppressed or unnecessary, and this can increase the service life of the power generation means, and thus the service life of the cogeneration system.
[0011]
In order to avoid frequent occurrence of a situation where the power generation output exceeds the power demand of the power consumption device due to fluctuations in the power demand of the power consumption device, use a small-capacity power generation means with a small rated power output or It is no longer necessary to adjust the power generation output according to fluctuations in the power demand of the power consuming equipment in a state where the power consumption is limited to be lower than the power demand of the power consuming equipment in advance. It can be secured high, and the energy saving effect of the cogeneration device can be enhanced.
[0012]
In addition, in a situation where the power generation output is insufficient with respect to the demand power of the power consuming device, the power supplied to the electric heater is limited to a predetermined minimum power, and the electric power received from the external commercial power source is unnecessary by the electric heater. By avoiding or suppressing the consumption, the energy saving effect of the cogeneration device can be enhanced, and further, the electric heater can be changed based on the detection result of the balance state between the demand power of the power consuming device and the power generation output of the power generation means. Therefore, the adjustment of the supply power to the electric heater according to the balance state between the demand power of the power consuming equipment and the power generation output of the power generation means is accurately performed, and the above-mentioned external commercial power supply side is adjusted. Prevention of reverse power flow and avoidance or suppression of unnecessary consumption of received power from an external commercial power source by an electric heater can be ensured.
[0013]
[2] In carrying out the invention according to claim 1, in the invention according to claim 2, the electric heater is configured to be heated against the water in the hot water storage tank together with the exhaust heat utilization heating means.
[0014]
According to this configuration, since the heat generated by the electric heater, that is, the heat generated by the excess of the generated power with respect to the demand power of the power consuming device is recovered and used for heating the water in the hot water tank, the exhaust heat generated by the power generation means Combined with the original energy saving effect of the cogeneration apparatus by heating the water in the hot water storage tank using the waste heat utilizing heating means, a higher energy saving effect can be obtained.
[0015]
In order to heat the electric heater with respect to the water in the hot water tank, the electric heater is directly heated with respect to the water in the hot water tank, or the electric heater is connected via an appropriate heat medium. Any method of heating the water in the hot water tank may be adopted.
[0016]
[3] In the invention according to claim 3, in implementing the invention according to claim 1 or 2, a plurality of the electric heaters are provided, and the heater adjusting means is configured to supply power from the branch power transmission line to the plurality of electric heaters. Is configured to adjust the total power supplied to the plurality of electric heaters.
[0017]
According to this configuration, regardless of whether it is AC power or DC power, the heater adjustment means can be configured with a simple switch structure such as a relay that selectively interrupts power supply to each electric heater. The apparatus configuration can be simplified in terms of adjusting the power supplied to the electric heater.
[0018]
If electric heaters with different rated power consumption are used for a plurality of electric heaters, the total electric power supplied to the electric heaters can be variously adjusted by the above selective electric power supply while reducing the number of electric heaters. It is possible to prevent the reverse power flow to the external commercial power source and to avoid or suppress unnecessary consumption of the received power from the external commercial power source by the electric heater. be able to.
[0019]
[4] In the invention according to claim 4, in carrying out the invention according to any one of claims 1 to 3, the reverse power flow prevention control means is provided with power detection means attached to a power receiving line from the external commercial power source. The balance state between the demand power of the power consuming device and the power generation output of the power generation means is detected based on the received power from the external commercial power source detected by the above.
[0020]
According to this configuration, for example, the demand power of the power consuming device and the power generation output of the power generation means are detected and the difference between them is calculated, and the demand power of the power consumption device and the power generation output of the power generation means are calculated. Compared to detecting the balance state, the balance state can be easily detected only by directly detecting the received power from the external commercial power source, and thus the apparatus configuration can be simplified.
[0021]
[5] In the invention according to claim 5, in implementing the invention according to any one of claims 1 to 4, the power generation means is configured to operate at a constant power generation output.
[0022]
According to this configuration, it is possible to more effectively prevent a decrease in the service life due to the output adjustment of the power generation means, and it is possible to further effectively increase the service life of the power generation means and, in turn, the service life of the cogeneration apparatus. .
[0023]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a cogeneration system using an engine-driven generator, in which a generator 1a and a gas engine 1b for driving the generator 1a are provided as a generator 1, and a power output line 2 of the generator 1 and an external commercial power source. The power receiving line 4 from 3 is connected to the power transmission line 6 to the power consuming device 5.
[0024]
Reference numeral 7 denotes a hot water storage tank, and 8 denotes exhaust heat utilization heating means for recovering exhaust heat generated by the power generation means 1 during power generation and heating the water in the hot water storage tank 7 with the recovered heat. Specifically, the means 8 includes a heat exchanger 8a for water heating provided in the hot water tank 7, and a heat medium heated by exhaust heat of the engine 1b (heat stored in the engine exhaust gas or heat taken away by engine cooling). It is comprised with the circulation path 8b which circulates R to the heat exchanger 8a.
[0025]
The hot water tank 7 is provided with an electric heater 9 that heats the water in the hot water tank 7 together with the heat exchanger 8a, and the electric heater 9 is connected to the electric power output line 2 of the power generation means 1. Electric power is supplied through the branched branch transmission line 10.
[0026]
11 is a control unit that adjusts the supply power Wh to the electric heater 9 in accordance with the balance state between the demand power Wz of the power consuming device 5 and the power generation output Wg of the power generation means 1, and the control unit 11 includes the electric heater As a heater adjusting means for adjusting the power supply Wh supplied to 9, a gate element 12 such as a thyristor interposed in a branch power transmission line 10 to the electric heater 9 and received power Win (power purchased) from the external commercial power source 3 are detected. A power detector 13 attached to the power receiving line 4 from the external commercial power source 3 as a power detecting means for controlling, and a controller 14 for controlling the gate element 12 based on detection information of the power detector 13 as a control means for preventing reverse power flow; Is equipped.
[0027]
When the controller 14 shows a tendency that the received power Win from the external commercial power source 3 detected by the power detector 13 decreases to less than 0 in the power relationship of Win = Wz + Wh−Wg, the external commercial power source 3, the power supply Wh supplied to the electric heater 9 is adjusted to increase so as to keep the received power Win from 3 at 0, while the power supply Wh supplied to the electric heater 9 is adjusted lower limit Wh = predetermined positive minimum value When the received power Win from the external commercial power source 3 detected by the power detector 13 shows an increasing tendency in a state where the power detector 13 has not yet decreased, the gate is adjusted so as to adjust the supplied power Wh to the electric heater 9 to the decreasing side. The element 12 is configured to be controlled (for example, phase angle control). Thus, when the power generation output Wg of the power generation means 1 is excessive with respect to the demand power Wz of the power consuming device 5, the excess power (= g-Wz) is consumed by the electric heater 9 to prevent the reverse power flow to the external commercial power source 3 side, and the power generation output Wg of the power generation means 1 is insufficient with respect to the demand power Wz of the power consuming device 5 the supply power Wh circumstances the electric heater 9, is limited to a predetermined minimum power, to suppress to consume unnecessarily the received power Win from external commercial power source 3 by an electric heater 9.
[0028]
As shown by the broken line in FIG. 2, the power generation means 1 is operated at a constant output at a rated output from the start of operation until the water in the hot water tank 7 rises to a predetermined temperature. As shown in FIG. 2, in a situation where the power generation output Wg of the power generation means 1 exceeds the demand power Wz of the power consuming equipment 5, the power 14h supplied to the electric heater 9 by the controller 14 (in other words, the power consumption of the electric heater 9). ), The excess (= Wg−Wz) of the power generation output Wg of the power generation means 1 is consumed by the electric heater 9 and used for heating the water in the hot water tank 7. In a situation where Wz exceeds the power generation output Wg of the power generation means 1, the power shortage (= Wz−) in a state where the power supply to the electric heater 9 is cut off by adjusting the power supply Wh to the electric heater 9 by the controller 14. Wg) is external Receiving from use power supply 3 is covered by (purchased power).
[0029]
[Another embodiment]
Next, another embodiment will be listed.
[0030]
In the above-described embodiment, the heater adjusting means is constituted by the gate element 12 such as a thyristor. However, various types of heater adjusting means for adjusting the electric power Wh supplied to the electric heater 9 can be adopted, for example, as shown in FIG. As shown, a plurality of electric heaters 9a to 9e are provided, and heater adjustment means are provided by switches 12a to 12e such as relays for selectively interrupting power supply from the branch power transmission line 10 to the electric heaters 9a to 9e. The switches 12a to 12e are configured to be selectively opened and closed by the controller 14 based on the detected received power Win by the power detector 13 to adjust the total supply power Wh to the plurality of electric heaters 9a to 9e. Good.
[0031]
In the apparatus configuration shown in FIG. 3, if electric heaters having different rated power consumption are used for the plurality of electric heaters 9a to 9e, the number of electric heaters 9a to 9e is reduced, but the number of electric heaters 9a to 9e is reduced. The total power supply Wh to the electric heaters 9a to 9e can be adjusted in various ways by the selective power supply to.
[0032]
In FIG. 3, reference numeral 15 denotes an inverter that converts a direct-current power output Wg into alternating current, whereas a direct-current power generation means such as a fuel cell is used as the power generation means 1, and in the apparatus configuration shown in FIG. When AC power generating means is used for 1, a rectifier 16 as shown by a broken line in the figure is interposed upstream of the inverter 15.
[0033]
When the electric heater 9 is heated together with the waste heat utilization heating means 8 and the water in the hot water tank 7 is heated, the electric heater 9 is directly heated against the water in the hot water tank 7 as in the above-described embodiment. 4, the electric heater 9 may be configured to heat the heat medium R circulated between the water heating heat exchanger 8 a and the power generation means 1.
[0034]
The heat generated by the electric heaters 9, 9a to 9e is not limited to heating the water in the hot water tank 7, but can be effectively used for various heat applications. In some cases, the heat generated by the electric heater 9 is shown in FIG. May be radiated to the outside.
[0035]
In the above-described embodiment, the branch power transmission line 10 to the electric heater 9 is branched from the power output line 2 of the power generation means 1, but this is not limiting, and the branch power transmission line 10 to the electric heater 9 is the power output of the power generation means 1. You may branch from any place in the connection system of the power receiving line 4 from the line 2 and the external commercial power source 3, and the power transmission line 6 to the power consuming equipment 5.
[0036]
In the above-described embodiment, the power detection means 13 attached to the power receiving line 4 from the external commercial power source 3 detects the received power Win from the external commercial power source 3, and the demand of the power consuming device 5 based on the detected received power Win. Although the balance state between the power Wz and the power generation output Wg of the power generation means 1 is detected, the specific detection means for detecting the balance state between the demand power Wz of the power consuming device 5 and the power generation output Wg of the power generation means 1 is as follows. Various configuration changes are possible. For example, the balance state between the demand power Wz of the power consuming device 5 and the power generation output Wg of the power generation means 1 may be detected in the form of calculating the difference.
[0037]
The power generation means 1 may be of any type as long as it generates exhaust heat with power generation, such as an engine-driven type that drives an electric generator with an engine, a fuel cell, or a gas turbine type. Also good.
[0038]
In the above-described embodiment, the power generation unit 1 is operated at a constant output. However, the power generation unit 1 is configured to adjust the output stepwise or gradually in accordance with the fluctuation of the demand power Wz of the power consuming device 5. The electric heater 9 may consume an excess of the generated power output Wg that does not follow the fluctuation of the demand power Wz of the power consuming device 5 by the stepwise or gradual output adjustment.
[Brief description of the drawings]
FIG. 1 is a device configuration diagram of a cogeneration apparatus showing an embodiment. FIG. 2 is a graph showing an operation mode of the device. FIG. 3 is a device configuration diagram showing another embodiment. FIG. 4 is an apparatus showing another embodiment. Configuration diagram [FIG. 5] Device configuration diagram showing another alternative embodiment [FIG. 6] Graph showing conventional power generation output adjustment mode [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electric power generation means 2 Electric power output line 3 External commercial power supply 4 Power receiving line 5 Electric power consumption apparatus 6 Power transmission line 7 Hot water storage tank 8 Waste heat utilization heating means 9 Electric heater 9a-9e Electric heater 10 Branch power transmission line 12 Heater adjustment means 12a-12e Heater Adjustment means 13 Power detection means 14 Reverse power flow prevention control means Wg Power generation output Wh of power generation means Power supplied to electric heater Win Power received from external commercial power supply Wz Demand power of power consuming equipment

Claims

Connect the power receiving line from the external commercial power source and the power output line of the power generation means to the power transmission line to the power consuming equipment,
A cogeneration apparatus provided with exhaust heat utilization heating means for recovering exhaust heat generated by the power generation means accompanying power generation and heating the water in the hot water storage tank with the recovered heat,
An electric heater that receives power supply through a branch transmission line from a connection system of a power transmission line to the power consuming device, a power reception line from the external commercial power source, and a power output line of the power generation means is provided, and the branch to the electric heater Provide heater adjustment means to adjust the power supplied from the power transmission line,
Detecting a balance state between the demand power of the power consuming device and the power generation output of the power generation means, and based on the detection result, in a situation where the power generation output of the power generation means is excessive with respect to the power demand of the power consumption device the excess power is consumed by the electric heater, and said in the context of insufficient power output to the power demand of the power consuming device of the power means to limit the power supplied to the electric heater to a predetermined minimum power The cogeneration apparatus is provided with reverse power flow prevention control means for controlling the heater adjustment means.

The cogeneration apparatus according to claim 1, wherein the electric heater is configured to heat the water in the hot water tank together with the exhaust heat utilization heating means.

A plurality of the electric heaters are provided, and the heater adjusting means is configured to selectively interrupt the power supply from the branch power transmission line to the plurality of electric heaters to adjust the total supply power to the plurality of electric heaters. The cogeneration apparatus according to claim 1 or 2.

Based on the received power from the external commercial power source detected by the power detection unit attached to the power receiving line from the external commercial power source, the reverse power flow prevention control means, The cogeneration apparatus according to any one of claims 1 to 3, wherein the cogeneration apparatus is configured to detect a balance state.

The cogeneration apparatus according to any one of claims 1 to 4, wherein the power generation means is configured to operate at a constant power generation output.