JP3585890B2

JP3585890B2 - Heating operation control method of triple effect absorption chiller / heater

Info

Publication number: JP3585890B2
Application number: JP2002019549A
Authority: JP
Inventors: 邦彦中島; 健一斉藤; 英治荒井; 和志牧田
Original assignee: Kawasaki Thermal Engineering Co Ltd
Current assignee: Kawasaki Thermal Engineering Co Ltd
Priority date: 2002-01-29
Filing date: 2002-01-29
Publication date: 2004-11-04
Anticipated expiration: 2022-01-29
Also published as: JP2003222424A

Description

【０００１】
【発明の属する技術分野】
本発明は、三重効用吸収冷温水機の暖房運転制御方法、詳しくは、暖房運転時の熱回収量が増えて暖房効率が向上し、かつ伝熱管の腐食を防止するようにした三重効用吸収冷温水機の暖房運転制御方法に関するものである。
【０００２】
【従来の技術】
従来から、蒸気式二重効用吸収冷凍機として、図４に例示したようなものが知られている。この吸収冷凍機は、吸収液（例えば、臭化リチウム水溶液）が吸収器ａから低温再生器ｃを経て高温再生器ｅに流されるというリバースサイクルを構成している。この吸収冷凍機における吸収サイクルを説明すると、まず、吸収器ａで多量の冷媒蒸気を吸収して濃度が薄められた吸収液（稀吸収液）が吸収器ａから低温熱交換器ｂに送給され、この低温熱交換器ｂにより加熱された後に低温再生器ｃに送給される。前記稀吸収液は、この低温再生器ｃにおいて低温再生され、吸収している冷媒の一部を放出し濃度がその分高くなって中間濃度の吸収液（中間吸収液）となる。次に、この中間吸収液は、低温再生器ｃから高温熱交換器ｄに送給され、この高温熱交換器ｄにより加熱された後に高温再生器ｅに送給される。
【０００３】
前記中間吸収液は、この高温再生器ｅにおいて高温再生され、吸収している冷媒（例えば、水蒸気）の一部を放出し濃度がさらに高くなって高濃度の吸収液（濃吸収液）となる。そして、この濃吸収液が前記高温熱交換器ｄの加熱側に前記中間吸収液を加熱する加熱源として戻され、さらに、低温熱交換器ｂの加熱側に前記稀吸収液を加熱する加熱源として戻された後、前記吸収器ａに帰還する。この帰還した濃吸収液は吸収器ａにおいて伝熱管上に散布され、冷却水により冷却されながら再び冷媒蒸気を吸収して前記稀吸収液となる。
【０００４】
このような蒸気式二重効用吸収冷凍機においては、前記高温再生器ｅには蒸気ボイラｆから高温の蒸気（スチーム）が加熱源として供給されるようになっており、この蒸気により中間吸収液が加熱されて吸収していた冷媒が放出され、この放出された冷媒蒸気は、低温再生器ｃにこの低温再生器ｃでの加熱源として利用された後、凝縮器ｇに戻されて凝縮する。凝縮器ｇからの冷媒液（例えば、水）は蒸発器ｈに入り、この凝縮した冷媒液が冷媒ポンプにより蒸発器ｈの伝熱管（水が流通している）に散布され蒸発潜熱により冷却されて冷水が得られる。
また、低温再生器ｃからの吸収液配管ｉと、高温熱交換器ｄと低温熱交換器ｂとの間の加熱側の吸収液配管ｊとを接続するバイパス管ｋが設けられ、低温再生器ｃを出て高温再生器ｅへ供給される中間濃縮吸収液の一部を、吸収器ａへ戻る濃吸収液配管にバイパスさせるように構成されている。
【０００５】
ボイラは通常、単独で運転する場合の制御は、外部の負荷変化によって変化するボイラ出口部の蒸気圧力変化を検出して、蒸気圧力が定められた圧力範囲内に入るように燃焼量を制御している。また、運転中はボイラ内の保有水が定められた水位の範囲内に入るよう給水ポンプを発停制御して水位を制御している。
一方、図４に示すような従来の吸収冷凍機においては、外部の負荷変化によって変化する冷凍機出口部又は入口部の冷水温度変化を検出して、冷凍機出口部又は入口部の温度が定められた温度になるよう、供給される熱源の量を制御している。
【０００６】
上記のボイラと吸収冷凍機については、インターロックを組んで連動運転をするなどの運転システムがあるが、制御はそれぞれ独立しているのが通常の運転システムである。ボイラは内部圧力が大気圧を越える圧力容器に該当し、吸収冷凍機は内部圧力が大気圧力以下の真空容器に該当する。このため、従来は両者を一体にして運転、制御することなどは無理なこととしてあきらめられていた。
しかし、環境問題などから、さらに省エネルギとなる冷温水機の開発が求められており、今回開発された本発明の冷温水機は、時代の要請に応えたものとなっている。
吸収冷凍機は、内部を循環し熱エネルギの交換をする媒体として、例えば臭化リチウム水溶液を保有している。一般的には吸収液と呼ばれ、冷媒となる水を吸収、蒸発させることによって冷房効果を発揮するよう構成されている。
また、特開２０００−１７１１２３号公報には、高温再生器、中温再生器、低温再生器、凝縮器、吸収器、蒸発器、熱交換器類、溶液ポンプ及び冷媒ポンプを主要構成機器とし、これらを溶液配管、冷媒配管で結んだ三重効用吸収冷凍機において、前記高温再生器に圧力センサと該高温再生器出口部に液面センサとを設け、該圧力センサの出力をもとに、吸収器から高温再生器に溶液を送る溶液ポンプの基本回転速度を設定し、該定した回転速度を前記液面センサで修正する溶液ポンプの回転速度制御装置を有する三重効用吸収冷凍機が記載されている。
【０００７】
特許第３２１５２４７号公報には、吸収冷温水機から温水を取り出す方法において、低温熱交換器の入口側である１次側から吸収液を取り出して蒸発器の液溜りへ供給する過程と、蒸発器の伝熱管表面に吸収液を散布させる過程と、この吸収液で蒸発器の伝熱管内の温水を加熱し、吸収液の温度を低下させる過程と、を包含する吸収冷温水機における高温度温水の取出方法が記載されている。
また、特公平６−４６１２２号公報には、吸収器、凝縮器、蒸発器、低温再生器に加えて、加熱装置を備えた高温再生器を有し、吸収器の吸収液を低温再生器から高温再生器へ導くリバースフロー式の吸収ヒートポンプを含む吸収冷凍機において、負荷が低くて前記高温再生器の収熱面及び排気ガス温度が所望外に低下したことを、高温再生器に取り付けた温度センサもしくは高温再生器から吸収液が導入される気液分離器に設けた圧力センサによって検出したとき、前記低温再生器から高温再生器へ導入される吸収液の液量を、前記低温再生器から高温再生器へ吸収液を導入する管路に設けた流量調整弁もしくは可変容量型吸収液ポンプの吐出量調整動作によって減少させ、前記高温再生器内の圧力を高めて高温再生器における吸収液及び収熱面の温度を高くし、排ガス温度を上昇させて高温再生器の収熱面での燃焼排ガスの結露を防止できるようにした二重効用吸収冷凍機の制御方法が記載されている。
【０００８】
【発明が解決しようとする課題】
図４に示すような、蒸気ボイラｆを組み合わせた従来の蒸気式吸収冷凍機においては、以下のような不都合がある。
蒸気ボイラｆはそれ自体が大型であり吸収冷凍機全体の大型化を招くことになる。しかも、その蒸気ボイラｆを運転させるには吸収冷凍機の系とは別の系の給水、加熱後の蒸気ドレンの回収、および薬品の注入等が必要になるなど省エネルギの要請に反する上に、それらのための付随設備が必要になり装置の大型化を助長している。しかるに、前記蒸気ボイラｆが吸収冷凍機に対し貢献するのは単に加熱源を供給するという役割をのみ果たすに止まっており、蒸気ボイラｆでの燃焼のための燃料消費に見合う効果を充分に得ているとは言い難い。その上、法規制上も、取り扱い者として所定の有資格者や検査等が必要になるという煩わしさを伴うものとなる。
【０００９】
吸収冷凍機とボイラを一体化して安定した運転を行うためには、ボイラとして必要な安全装置と、吸収冷凍機として必要な冷水温度制御装置を結合させ、安定して安全な運転が継続できるようにする必要がある。
吸収冷凍機とボイラを一体化して運転を行う場合には、蒸気の圧力制御はあまり重要な条件にはならない。それよりも、吸収冷凍機として求められている冷水温度を安定して供給することが重要になり、冷水温度が安定して供給できるよう加熱源のコントロールを十分に行うことが重要になる。
一方、ボイラでは吸収冷凍機が負荷変化などにより冷水温度が変化し加熱源の量をコントロールする信号が出て、蒸気圧力が変動したり、内部保有水の水位が急激に変動しても連続して運転ができるように制御されなくてはならない。
【００１０】
そこで、吸収冷凍機の冷水温度制御とボイラの燃焼量制御を一対の制御とすると、別にボイラの蒸気圧変化、水位変化を検出して、吸収冷凍機に装備されている吸収液ポンプの回転数を制御して吸収液の循環量を制御する制御システムを構築して、ボイラの運転中の影響を少なくする制御を行うことにより、吸収冷凍機とボイラを一体化しても、ボイラの安定して安全な燃焼コントロールと吸収冷凍機としての安定した冷水温度制御が可能になる。
そのための制御として、蒸気温度もしくは圧力検出による吸収液ポンプの回転数制御、又は運転液面検出による吸収液ポンプの回転数制御が重要な要件になる。
しかし、その際にもボイラとして要求される安全弁、低水位燃焼遮断装置、給水装置は装備しておかなければならない。
なお、前記特開２０００−１７１１２３号公報記載の三重効用吸収冷凍機においては、ポンプ毎に周波数を変えるような制御は行われていない。また、ポンプ吸込み口から分岐して戻り配管に戻すバイパス回路も設けられていない。また、この公報には、吸収冷凍機に貫流ボイラ等のボイラを組み合わせて一体化することは、何も記載されていない。
【００１１】
上記の特許第３２１５２４７号公報に示されるように、吸収液と冷媒を混合した吸収液を蒸発器内で蒸発器管に散布して、蒸発器管内を流動する循環水の温度を上げ暖房運転を行い、ビル空調設備等の暖房に使用する温水として供給する吸収冷温水機は良く知られている。
図３は、二重効用形ですでに実施されている暖房運転と同じ例を用いた方式で、本出願人が開発している三重効用吸収冷温水機を示す。蒸発器８９に低温再生器８４で発生した冷媒蒸気を吹きつけ、冷媒蒸気が凝縮する際に温水と熱交換して温水の温度を上げる仕組みを示す。１５１は冷暖切替弁で、暖房運転時は開け、冷房運転時は閉める。１０は高温再生器、８１は吸収器、８７は中温再生器、８８は凝縮器である。
また、吸収液の一部又は燃焼用空気と、燃焼排ガスとを熱交換して効率を上げるために、排ガス熱交換器（又はエアヒータ）を装備した装置とすることもある。
いずれの場合も効率良く運転を行い、燃料消費量を削減することを目的として計画され、その効果も奏されている。また、熱交換器を取りつける位置を変えることにより、熱回収をさらに効率良く行う工夫とその装置も開発されている。しかし、実際に運転を行った場合に生じる問題点などには触れられておらず、また、その具体的な問題点と対策について検討されていない。
【００１２】
実際の運転時には、外部環境の影響による負荷変化などさまざまな問題が生じている。定格条件で運転している場合には何ら問題が生じないが、低負荷運転になると運転条件に制御を加えるため、定格運転時より各部のサイクル循環温度が低下している。また、温度が低下した場合に生じる問題について対策が講じられていないために、重大な問題に発展する恐れのある腐食を生じる。
具体的には、負荷変化などにより吸収冷凍機において燃焼量の制御を行った時に、各部の溶液循環温度が下がることにより生ずる排ガス熱交換器出口部の排ガス温度の低下により生ずる問題がある。
排ガス温度が低下して、例えば、１００℃以下になると、排ガス中の水蒸気分が凝縮してドレンとなるためで、排ガス熱交換器中で排ガス中の水蒸気分が凝縮すると排ガス中に含まれる硫黄酸化物や空気中の炭酸ガスが凝縮水に一緒に溶け込んで腐食性の水溶液となり、このため、排ガス熱交換器の伝熱管表面を激しく腐食する。管内を流れる吸収液の温度は８０℃程度まで下がる。
蒸発器に吸収液を導き、冷媒ポンプによりその吸収液を蒸発器伝熱管に散布すると、従来の方式よりも効率良く、また高温の暖房用温水が得られることは、従来から二重効用形の例がある。
しかし、過去の例ではそれぞれを、単独に又は弁の開閉を固定にしたもので、効率向上と凝縮ドレン発生の防止を同時に満たすものではなく、効率向上のために凝縮ドレンの発生はやむおえないものとあきらめ、高級材質を使用した熱交換器などにより対応している。
本発明では、その問題点を解決するための対策を提供し、冷温水機を連続して運転する上で障害となる問題を生じさせない制御を行う。
【００１３】
本発明は上記の諸点に鑑みなされたもので、本発明の目的は、貫流タイプのボイラを高温再生器として、このボイラと吸収冷凍機とを一体化し、ボイラ側でこれらの装置に異常が生じた場合には、ボイラの燃焼遮断と連動して吸収冷凍機も安全停止する制御回路を組み込むようにした連続運転の可能な省エネルギ形の吸収冷温水機の暖房運転制御方法を提供することにある。
すなわち、本発明の目的は、貫流方式ボイラ又は貫流方式ボイラと同等の構造を持つ高温再生器、中温再生器、低温再生器、凝縮器、吸収器、蒸発器、熱交換器類、溶液ポンプ、冷媒ポンプ、冷暖切替弁及び排ガス熱交換器を有する三重効用吸収冷温水機を構成し、この冷温水機において暖房運転時に負荷側に供給する温水温度に悪影響を与えることなく、かつ、効率低下を招くことなく制御するように、吸収液の流量を制御する制御弁を設け、排ガス温度の所定温度以下の低下防止及びドレンの発生を防止して、伝熱管の腐食を防止するようにした安全装置、制御装置を備えた三重効用吸収冷温水機の暖房運転時の制御方法を提供することにある。
【００１４】
【課題を解決するための手段】
上記の目的を達成するために、本発明の三重効用吸収冷温水機の暖房運転制御方法は、貫流方式ボイラ又は貫流方式ボイラと同等の構造を持つボイラを高温再生器として、このボイラと吸収冷凍機とを一体化した三重効用吸収冷温水機で、高温再生器、中温再生器、低温再生器、凝縮器、吸収器、蒸発器、熱交換器類、溶液ポンプ、冷媒ポンプ、冷暖切替弁（第１弁）及び排ガス熱交換器を有し、吸収器の吸収液を低温再生器から中温再生器へ、ついで高温再生器へ導くリバースフロー式の三重効用吸収冷温水機であって、冷温水温度センサから負荷側の温度変化を検出し、その温度変化を運転制御・安全制御用運転盤（以下、運転盤と称す）からの制御信号によりボイラに供給される燃料（ガス、油、廃熱）を増減し、燃焼装置の燃焼量を増減してボイラの効率的な運転を行い、同時に吸収冷凍機の各吸収液ポンプを運転して、水の含有割合の異なる吸収液を安定的に供給（循環）して連続運転が可能となる液の循環流動用配管を有し、低温再生器から上位の再生器に液を供給する吸収液ポンプに流入する吸収液の一部を分岐して戻り配管にバイパスする配管を有し、同時に中温再生器から水・吸収液供給ポンプに流入する液の一部を分岐して戻り配管にバイパスする配管を有して、水・吸収液（吸収液）の供給量（循環量）を調整して、ポンプに掛かる動力負荷を調整して、省エネルギと安定した連続運転ができるようにし、高温再生器の排ガス通路に排ガス熱交換器を設け、この排ガス熱交換器に、低温再生器から中温再生器に液を供給する吸収液ポンプからの液の一部を排ガス熱交換器用吸収液供給管を介し導入して排ガスで加熱するようにし、この排ガス熱交換器の出口の排ガス通路に排ガス温度センサを設け、この排ガス温度センサと前記運転制御・安全制御用運転盤とを連動接続し、さらに、高温熱交換器と低温熱交換器との間の加熱側の吸収液配管に、吸収液を蒸発器に導入するための蒸発器用吸収液供給管を接続し、該蒸発器用吸収液供給管に第２弁を、吸収器への帰還吸収液管に第３弁を、前記排ガス熱交換器用吸収液供給管に第４弁を設けるとともに、該第４弁にバイパス管を接続した三重効用吸収冷温水機において、排ガス温度センサで検知される排ガス温度がドレン発生温度以下にならないように、第２弁、第３弁及び第４弁の少なくともいずれかを単独に又は同時に制御し、かつ、蒸発器の冷媒ポンプを発停制御して排ガス熱交換器内での凝縮水の発生を防止するように構成されている。
【００１５】
この制御方法において、排ガス温度センサで検知される温度がドレン発生温度を超える場合、第２弁を全開、第３弁を全閉、第４弁を全開とし、かつ、冷媒ポンプを運転するとともに吸収液ポンプを運転して、高温に加熱された吸収液を蒸発器管に散布する。
【００１６】
また、排ガス温度センサで検知される温度がドレン発生温度を超える場合、第２弁を全閉から全開の間で自動制御し、第２弁が全閉に近づいた時に作動していた冷媒ポンプを停止し、第３弁は使用しないか、予め設けず、第４弁は全開とし、吸収液ポンプを運転して、高温に加熱された吸収液を蒸発器管に散布する。
【００１７】
また、排ガス温度センサで検知される温度がドレン発生温度以下の場合、第２弁を全閉、第３弁を全開、第４弁を全開とし、かつ、冷媒ポンプを停止するとともに吸収液ポンプを運転して、冷暖切替弁から流入する冷媒蒸気、冷媒蒸気ドレンのみを蒸発器管に散布して、伝熱管内を流れる温水と熱交換させる。
【００１８】
これらの制御方法において、第４弁を使用しないか、予め設けないように構成することも可能である。
また、排ガス温度センサで検知される温度がドレン発生温度以下にならないように、第４弁の開度を調節して排ガス熱交換器へ循環する吸収液量をコントロールする場合もある。
【００１９】
排ガス温度センサで排ガス温度を検知して制御する代りに、排ガス熱交換器伝熱管又は該伝熱管の出口に吸収液温度センサを設け、該吸収液温度センサで排ガス熱交換器内を流れる吸収液温度を検知して制御する場合もある（図２参照）。
【００２０】
第４弁を使用する場合は、排ガス熱交換器へ循環する吸収液の流動が止まらないように第４弁を流れる液の一部をバイパスさせる。
また、これらの制御方法において、蒸発器へ循環する吸収液の流動が止まらないように第２弁を流れる液の一部をバイパスさせることが好ましい。
また、吸収冷温水機の燃焼量を、冷温水温度センサで感知した温度が予め設定した温度に対してずれた時に増減コントロールすることが好ましい。
また、高温再生器に液面検出・制御装置を設け、高温再生器の液面を制御して液面低下を防止するように構成することが好ましい。
【００２１】
これらの冷温水機において、負荷（冷温水）の温度変化によって燃焼装置の燃焼量（加熱量）を増減するのと同時に、ボイラ内部の蒸気圧が上昇し温度が上昇して、蒸気で加熱される吸収冷凍機の中温再生器出口部の蒸気ドレン温度センサで検出する温度が上昇した場合には、安全のため吸収液供給ポンプの回転数を上げて、液循環量を増加させてその結果蒸気圧を下げるようにし、ドレン温度が低下すれば吸収液供給ポンプの回転数を下げて液循環量を減らして蒸気圧を上げるようにし、連続運転に適した温度範囲と圧力範囲で安定した運転が継続できるようにした制御機能を持つように構成する。
【００２２】
また、負荷（冷温水）の温度変化によって燃焼装置の燃焼量（加熱量）を増減するのと同時に、ボイラ内部の蒸気圧が上昇し温度が上昇して、ボイラ出口部の蒸気配管で検出される、蒸気圧力又は温度センサで検出する温度が上昇した場合には、安全のため吸収液供給ポンプの回転数を上げて、液循環量を増加させてその結果蒸気圧を下げるようにし、蒸気圧力又は温度が低下すれば吸収液供給ポンプの回転数を下げて液循環量を減らして蒸気圧を上げるようにし、連続運転に適した温度範囲と圧力範囲で安定した運転が継続できるようにした制御機能を持つように構成する。
【００２３】
これらの冷温水機において、ボイラの運転中の液面を液面検出装置により検出して、液面が上昇した場合にはポンプの回転数を減らし、液循環量を減らして液面が下がるようにし、液面が低下した場合には、ポンプの回転数を増やして液循環量を増やし液面が上がるように制御し、また、運転液面が安全運転の下限設定値よりさらに低下した場合には警報を発し燃焼を遮断して安全停止動作に入るようにした安全制御機能を持つように構成する。
また、運転中の蒸気ドレン温度、蒸気温度、蒸気圧力又はボイラの運転液面を検出して、ポンプの回転数を制御する場合に、制御は低温吸収液ポンプ、高温吸収液ポンプ、水・吸収液供給ポンプの各ポンプを同時に、もしくは単独に、又は低温吸収液ポンプと水・吸収液供給ポンプの２台だけのような組合せの中から選択した運転方法から１方式を又は複数の方式を切り替えられるようにして、回転数制御をして水を含む吸収液の供給量（循環量）を制御し運転効率を高めるようにして、かつ各ポンプが供給量（循環量）不足や揚程不足を起こさない回転数を確保するように制御するように構成する。
【００２４】
これらの冷温水機において、運転中に、ボイラへの水・吸収液を供給する供給装置が故障して、供給量が減少した場合には、ボイラ内部に保有する水・吸収液量が減少して連続運転に支障を生じるので、警報を発すると同時に燃焼を遮断して、安全停止動作に入るようにした安全制御機能を持つ構成とする。
また、運転中に、ボイラへの水・吸収液供給量が減少した場合や、ボイラ内部に保有する水・吸収液量が減少して各部の温度が安全運転の設定値を越えた場合には、ボイラに設けた吸収液温度センサや空缶防止吸収液温度センサにより警報を発すると同時に燃焼を遮断して、安全停止動作に入るようにした安全制御機能を持つ構成とする。
【００２５】
さらに、ボイラが、加熱されて蒸発した蒸気、蒸発しなかった吸収液及びボイラに再循環する水を含む吸収液をそれぞれ分離して連続運転が可能となるよう蒸気、吸収液を分配する気液分離器を備えるボイラである構成とする。
【００２６】
上記の吸収冷温水機において、冷温水温度センサから負荷側の温度変化を検出し、その温度変化を運転制御・安全制御用運転盤（運転盤）からの制御信号によりボイラに供給される燃料（ガス、油、廃熱）を増減し、燃焼装置の燃焼量を増減してボイラの効率的な運転を行い、同時に吸収冷凍機の各吸収液ポンプを運転して、水の含有割合の異なる吸収液を安定的に供給（循環）して連続運転を可能とし、低温再生器から上位の再生器に液を供給する吸収液ポンプに流入する吸収液の一部を分岐して戻り配管にバイパスさせ、同時に中温再生器から水・吸収液供給ポンプに流入する液の一部を分岐して戻り配管にバイパスさせ、水・吸収液（吸収液）の供給量（循環量）を調整して、ポンプに掛かる動力負荷を調整して、省エネルギと安定した連続運転を行う。
【００２７】
この方法において、負荷（冷温水）の温度変化によって燃焼装置の燃焼量（加熱量）を増減するのと同時に、ボイラ内部の蒸気圧が上昇し温度が上昇して、蒸気で加熱される吸収冷凍機の高温再生器出口部の蒸気ドレン温度センサで検出する温度が上昇した場合には、安全のため吸収液供給ポンプの回転数を上げて、液循環量を増加させてその結果蒸気圧を下げ、ドレン温度が低下すれば吸収液供給ポンプの回転数を下げて液循環量を減らして蒸気圧を上げ、連続運転に適した温度範囲と圧力範囲で安定した運転が継続できるように制御するように構成する。
【００２８】
また、負荷（冷温水）の温度変化によって燃焼装置の燃焼量（加熱量）を増減するのと同時に、ボイラ内部の蒸気圧が上昇し温度が上昇して、ボイラ出口部の蒸気配管で検出される、蒸気圧力又は温度センサで検出する温度が上昇した場合には、安全のため吸収液供給ポンプの回転数を上げて、液循環量を増加させてその結果蒸気圧を下げ、蒸気圧力又は温度が低下すれば吸収液供給ポンプの回転数を下げて液循環量を減らして蒸気圧を上げ、連続運転に適した温度範囲と圧力範囲で安定した運転が継続できるように制御するように構成する。
【００２９】
これらの方法において、ボイラの運転中の液面を液面検出装置により検出して、液面が上昇した場合にはポンプの回転数を減らし、液循環量を減らして液面を下げ、液面が低下した場合には、ポンプの回転数を増やして液循環量を増やし液面を上げるように制御し、また、運転液面が安全運転の下限設定値よりさらに低下した場合には警報を発し燃焼を遮断して安全停止動作に入るように制御する。
【００３０】
この方法において、ボイラの運転中の液面を液面検出装置により検出して、ポンプの回転数を制御する方法として、運転条件、制御信号を受けて、あらかじめ定めた回転数に段階的に変化させるようにした段階制御式を用いる方法としたり、又は、ボイラの運転中の液面を液面検出装置により検出して、ポンプの回転数を制御する方法として、運転条件、負荷信号、制御信号を受けて、連続的に回転数を変化させるようにした連続制御式を用いる方法とする。
【００３１】
これらの方法において、運転中の蒸気ドレン温度、蒸気温度、蒸気圧力又はボイラの運転液面を検出して、ポンプの回転数を制御する場合に、制御は低温吸収液ポンプ、高温吸収液ポンプ、水・吸収液供給ポンプの各ポンプを同時に、もしくは単独に、又は低温吸収液ポンプと水・吸収液供給ポンプの２台だけのような組合せの中から選択した運転方法から１方式を又は複数の方式を切り替えられるようにして、回転数制御をして水を含む吸収液の供給量（循環量）を制御し運転効率を高め、かつ各ポンプが供給量（循環量）不足や揚程不足を起こさない回転数を確保するように制御する。
【００３２】
これらの方法において、運転中に、ボイラへの水・吸収液を供給する供給装置が故障して、供給量が減少した場合には、ボイラ内部に保有する水・吸収液量が減少して連続運転に支障を生じるので、警報を発すると同時に燃焼を遮断して、安全停止動作に入るように制御する。
また、運転中に、ボイラへの水・吸収液供給量が減少した場合や、ボイラ内部に保有する水・吸収液量が減少して各部の温度が安全運転の設定値を越えた場合には、ボイラに設けた吸収液温度センサや空缶防止吸収液温度センサにより警報を発すると同時に燃焼を遮断して、安全停止動作に入るように制御する。
【００３３】
これらの方法において、ボイラとして、加熱されて蒸発した蒸気、蒸発しなかった吸収液及びボイラに再循環する水を含む吸収液をそれぞれ分離して連続運転が可能となるよう蒸気、吸収液を分配する気液分離器を備えるボイラを用いるように構成する。
【００３４】
【発明の実施の形態】
以下、本発明の実施の形態について説明するが、本発明は下記の実施の形態に何ら限定されるものではなく、適宜変更して実施することができるものである。図１は、本発明の実施の第１形態による制御方法を実施する吸収冷温水機を示している。高温再生器としては、貫流方式ボイラ又はこれと同等の機能、構造を有するボイラが用いられるが、本実施形態では、高温再生器として貫流式ボイラ形のものを用いる場合を示している。１０は貫流式ボイラ構造の高温再生器で、上部と下部に環状の上部管寄せ（上部ヘッダー）１２及び下部管寄せ（下部ヘッダー）１４を有し、これらの管寄せ１２、１４間に鉛直方向の多数の上昇管１６を略円筒状に配設し、上部中央部に燃焼装置１８、例えばバーナーを有し、稀吸収液を下部管寄せ１４に導入して加熱濃縮し、上部管寄せ１２から気液混合物を取り出すことができるように構成されている。２０は燃焼室である。
【００３５】
この高温再生器１０に気液混合物導管２４を介して気液分離器２６が接続されている。気液分離器２６の上部には蒸気抜出導管２８が接続され、気液分離器２６の下側部には吸収液抜出導管３０が接続されている。
気液分離器２６の下部と高温再生器１０の下部管寄せ１４とは、吸収液循環導管３６を介して接続されている。吸収液循環導管３６又は下部管寄せ１４には、吸収液供給管４２が接続されている。４４は気液分離器２６の液面検出・制御装置である。また、下部管寄せ１４の下面又は側面には、空缶防止用の吸収液温度センサ４６が設けられている。
【００３６】
本実施形態は、吸収器８１、ポンプ（稀液ポンプ）８２、低温熱交換器８３、低温再生器８４、ポンプ（中間液ポンプ）８５、高温熱交換器８６、中温再生器８７、凝縮器８８、蒸発器８９、冷媒ポンプ９０及びこれらの機器を接続する吸収液配管、冷媒配管等を構成要素とするリバースサイクル式の二重効用式吸収冷凍機に対し、貫流式ボイラ構造の高温再生器１０、溶液供給手段としての水・吸収液供給ポンプ９３、付加熱交換器９４等を組み合わせて一体化したものである。なお、図１において、実線に付した矢印は吸収液、冷媒液又は水の流れ方向を示し、破線に付した矢印は冷媒蒸気、又は冷媒蒸気と凝縮冷媒（冷媒ドレン）との混合物の流れ方向を示す。
【００３７】
９５は第一バイパス管で、低温再生器８４からの吸収液の一部を高温熱交換器８６からの濃吸収液配管にバイパスさせるためのものである。また、９６は第二バイパス管で、中温再生器８７からの吸収液の一部を付加熱交換器９４からの戻り濃吸収液配管にバイパスさせるためのものである。９９は冷温水ポンプ、１００は冷却水ポンプ、１５１は冷暖切替弁（第１弁）で、暖房運転時は全開、冷房運転時は全閉とされる。なお、中温再生器８７と高温再生器１０との間に別の濃縮器を設置することも可能である。
【００３８】
つぎに、上記のように構成された吸収冷凍機において、吸収液の循環サイクルについて順に説明する。まず、吸収器８１で多量の冷媒蒸気を吸収して濃度が薄められた稀吸収液が、稀液ポンプ８２によって吸収器８１から低温熱交換器８３に送給され、この低温熱交換器８３により加熱された後に低温再生器８４に送給される。そして、この稀吸収液は、この低温再生器８４において低温再生され、吸収している冷媒の一部を放出し濃度がその分高くなって中間濃度の中間吸収液となる。
【００３９】
この中間濃縮吸収液の大部分は、低温再生器８４から中間吸収液ポンプ８５によって高温熱交換器８６に送給され、この高温熱交換器８６により加熱された後に中温再生器８７に送給される。この中間濃縮吸収液は、この中温再生器８７において高温再生され、吸収している冷媒の一部を放出し濃度がさらに高くなって高濃度の濃吸収液となる。
低温再生器８４からの中間濃縮吸収液の残部は、吸収器８１へ戻る濃吸収液配管にバイパス管９５を経てバイパス供給される。
【００４０】
中温再生器８７からの濃吸収液の一部又は全部は、吸収液ポンプ９３により付加熱交換器９４へ送給され、ここで、高温再生器１０からの濃吸収液と熱交換して加熱された後、高温再生器１０に供給される。中温再生器８７からの濃吸収液の残部（零の場合もあり得る）は、第二バイパス管９６を経て付加熱交換器９４からの加熱側の吸収液配管に合流する。
【００４１】
高温再生器１０において、燃料の燃焼熱により加熱濃縮された濃吸収液は、付加熱交換器９４の加熱側に導入されて中温再生器８７からの濃吸収液を加熱した後、高温熱交換器８６の加熱側に導入される。中温再生器８７からの濃吸収液の残部（零の場合もあり得る）は、第二バイパス管９６を経て付加熱交換器９４からの加熱側の吸収液配管に合流する。
高温再生器１０からの冷媒蒸気は蒸気抜出導管２８を経て中温再生器８７へ導入され、ここで吸収液を加熱濃縮させた後、冷媒ドレンは低温再生器８４へ導入される。
【００４２】
中温再生器８７からの冷媒蒸気は冷媒蒸気配管９７を経て、中温再生器８７からの冷媒ドレンとともに低温再生器８４に送られ、ここで吸収液を加熱濃縮させる。
低温再生器８４からの冷媒蒸気は冷媒蒸気配管９８を経て、低温再生器８４からの冷媒ドレンとともに凝縮器８８に導入される。後で詳細に説明するが、高温再生器１０からの燃焼排ガスを排ガス熱交換器１２０に導入して、吸収液を加熱し、排ガスの保有熱を回収するように構成している。
【００４３】
上記のように構成された吸収冷温水機において、さらに次のような構成が付加される。すなわち、冷温水取出管に冷温水温度センサ１０２が設けられ、中温再生器８７からの蒸気ドレン管に蒸気ドレン温度センサ１０４が設けられ、気液分離器２６からの吸収液抜出導管３０に吸収液温度センサ１１２が設けられ、蒸気抜出導管（蒸気供給管）２８に蒸気温度センサ１１６、圧力計（圧力センサ）１１８が設けられている。蒸気ドレン温度センサ、蒸気温度センサ、蒸気圧力センサは同時に設けるのではなく、どれか１つを選択して設ければよい。また、２つ以上設けてもよい。また、前述のように、貫流式ボイラ１０の下部管寄せ１４の下面に空缶防止用の吸収液温度センサ４６が設けられている。
【００４４】
また、運転制御・安全制御用運転盤１１４が設けられ、この運転盤１１４と、冷温水温度センサ１０２、蒸気ドレン温度センサ１０４、気液分離器の液面検出・制御装置４４、燃焼装置１８、吸収液温度センサ１１２、空缶防止用の吸収液温度センサ４６、稀液ポンプ（低温吸収液ポンプ）８２、中間液ポンプ（高温吸収液ポンプ）８５、水・吸収液供給ポンプ９３、蒸気抜出導管（蒸気供給管）２８の蒸気温度センサ１１６、圧力計（圧力センサ）１１８、排ガス温度センサ１２４とが連動接続されて、これら各部の温度、圧力、流量等が制御できるように構成されている。なお、蒸気ドレン温度センサ、蒸気温度センサ、蒸気圧力センサは同時に設けるのではなく、どれか１つを選択して設ける。また、２つ以上設けてもよい。
【００４５】
さらに、高温熱交換器８６と低温熱交換器８３との間の加熱側の吸収液配管１５６に、吸収液を蒸発器８９に導入するための蒸発器用吸収液供給管１５８を接続し、該蒸発器用吸収液供給管１５８に第２弁１５２を、吸収器８１への帰還吸収液管１６０に第３弁１５３を、排ガス熱交換器１２０に吸収液の一部を送るための排ガス熱交換器用吸収液供給管１６２に第４弁１５４を設けるとともに、該第４弁１５４にバイパス管１６４を接続して三重効用吸収冷温水機を構成する。この三重効用吸収冷温水機において、排ガス温度センサ１２４で検知される排ガス温度がドレン発生温度以下、例えば１００℃以下にならないように、第２弁１５２、第３弁１５３及び第４弁１５４の少なくともいずれかを単独に又は同時に制御し、かつ、蒸発器の冷媒ポンプ９０を発停制御して排ガス熱交換器１２０内での凝縮水の発生を防止する。
【００４６】
新しく追加された吸収液量の制御を行う第２弁１５２、第３弁１５３、第４弁１５４は、ＯＮ−ＯＦＦ弁でも比例制御弁でもよい。これらの弁、バイパス弁で、排ガス温度が下がり過ぎないように、有効な組合せによる制御を行う。
ドレン発生温度は一例として１００℃としたが、運転条件により、例えば９０℃のように設定値を変更することがじきる。
【００４７】
このように構成された吸収冷温水機の作用について説明する。蒸発器８９からの冷温水取出管に設けられた冷温水温度センサ１０２から負荷側の温度変化を検出し、その温度変化を運転制御・安全制御運転盤１１４からの制御信号を燃焼装置１８又は燃料流量調節弁（図示略）に導入することにより高温再生器１０に供給される燃料を増減し、燃焼装置１８の燃焼量を増減して高温再生器１０の効率的な運転を行う。
同時に各吸収液ポンプ８２、８５、９３を運転して、水の含有割合の異なる吸収液を安定的に供給・循環して連続運転を行う。すなわち、低温再生器８４から中温再生器８７に液を供給する吸収液ポンプ８５に流入する吸収液の一部を分岐させてバイパス管９５により戻り配管にバイパスさせ、同時に中温再生器８７から水・吸収液供給ポンプ９３に流入する液の一部を分岐させてバイパス管９６によりバイパスさせ、水・吸収液の供給・循環量を調整して、ポンプ８５、９３に掛かる動力負荷を調整して、省エネルギと安定した連続運転を行う。
【００４８】
また、負荷（冷温水）の温度を冷温水温度センサ１０２で検知し、運転盤１１４を介して燃焼装置１８の燃焼量（加熱量）を増減すると同時に、高温再生器１０内部の蒸気圧が上昇し温度が上昇して、蒸気で加熱される吸収冷凍機の高温再生器出口部の蒸気ドレン温度センサ１０４で検出する温度が上昇した場合には、安全のため、運転盤１１４を介して吸収液供給ポンプ９３の回転数を上げて、液循環量を増加させてその結果蒸気圧を下げ、蒸気ドレン温度センサ１０４で検出するドレン温度が低下すれば、運転盤１１４を介して吸収液供給ポンプ９３の回転数を下げて循環液量を減らして蒸気圧を上げ、連続運転に適した温度範囲と圧力範囲で安定した運転が継続できるようにする。ポンプ９３と同時にポンプ８２を回転数制御すると、さらに対応速度を速める効果がある。ポンプ８５は、回転数を変えずに一定速度で運転しても、バイパス管９５で流量が調整されるので、回転数を制御しなくても、問題は生じない。
【００４９】
又は、負荷（冷温水）の温度変化によって燃焼装置１８の燃焼量（加熱量）を増減するのと同時に、高温再生器１０内部の蒸気圧が上昇し温度が上昇して、高温再生器出口部の蒸気配管で検出される、蒸気圧又は温度センサ１１６で検出する温度が上昇した場合には、安全のため吸収液ポンプ９３の回転数を上げて、液循環量を増加させて、その結果蒸気圧を下げ、蒸気圧力又は温度が低下すれば、吸収液供給ポンプ９３の回転数を下げて液循環量を減らして蒸気圧を上げ、連続運転に適した温度範囲と圧力範囲で安定した運転が継続できるようにする。ポンプ９３の回転数を上げ下げするのと同時に、ポンプ８２の回転数を上げ下げすると、応答速度が速まり制御性がよくなるという効果がある。
【００５０】
また、高温再生器１０の運転中の液面を液面検出・制御装置４４により検出して、気液分離器２６の液面が上昇した場合には、水・吸収液供給ポンプ９３の回転数を減らし、液循環量を減らして液面を下げる。一方、液面が降下した場合には、ポンプ９３の回転数を増やして液循環量を多くし液面を上げるように制御する。また、高温再生器１０の運転液面が安全運転の下限設定値よりさらに低下した場合には、運転盤１１４を介して、警報を発し燃焼を遮断して安全停止動作に入るようにする。
【００５１】
この場合、高温再生器１０の運転中の液面を液面検出・制御装置４４により検出して、ポンプ９３の回転数を制御する方法として、運転条件、制御信号を受けて予め定められた回転数に段階的に変化させるようにした段階制御式を用いる方法や、運転条件、負荷信号、制御信号を受けて連続的に回転数を変化させるようにした連続制御式を用いる方法等が採用される。
【００５２】
運転中の蒸気ドレン温度、蒸気温度、蒸気圧力又はボイラの運転液面を、蒸気ドレン温度センサ１０４、蒸気温度センサ１１６、蒸気圧力計１１８又は液面検出装置４４で検出して、ポンプの回転数を制御する場合に、制御方式としては、低温吸収液ポンプ８２、高温吸収液ポンプ８５、水・吸収液供給ポンプ９３の各ポンプを同時にもしくは単独に、又は低温吸収液ポンプ８２と水・吸収液供給ポンプ９３の２台だけ等の組合せの中から選択した運転方法から、１方式又は複数の方式に切り替えられるようにして、回転数制御をして水を含む吸収液の供給量（循環量）を制御し運転効率を高め、かつ各ポンプが供給量（循環量）不足や揚程（ヘッド）不足を起こさない回転数を確保するように制御される。
【００５３】
また、運転中に、高温再生器１０への水・吸収液を供給する供給装置、例えば水・吸収液供給ポンプ９３が故障して、供給量が減少した場合には、高温再生器１０内部に保有する水・吸収液量が減少して連続運転に支障が生じるので、警報を発すると同時に燃焼を遮断して、安全停止動作に入るように制御する。
【００５４】
また、運転中に、高温再生器１０への水・吸収液供給量が減少した場合や、高温再生器１０内部に保有する水・吸収液量が減少して各部の温度が安全運転の設定値を越えた場合には、高温再生器１０又は高温再生器１０の吸収液出口部に設けた吸収液温度センサ１１２や空缶防止用の吸収液温度センサ４６により運転盤１１４を介して警報を発すると同時に燃焼を遮断して、安全停止動作に入るように制御する。
【００５５】
排ガス温度センサ１２４で検知される温度がドレン発生温度を超える場合、第２弁１５２を全開、第３弁１５３を全閉、第４弁１５４を全開とし、かつ、冷媒ポンプ９０を運転するとともに吸収液ポンプ８２、８５、９３を運転して、高温に加熱された吸収液を蒸発器管に散布して（例えば、暖房に利用する）温水と直接熱交換させる。このため、きわめて効率のよい運転となり、取り出される温水の温度を８０℃程度まで上げることが可能になる。
【００５６】
また、排ガス温度センサ１２４で検知される温度がドレン発生温度を超える場合、第２弁１５２を全閉から全開の間で自動制御し、第２弁１５２が全閉に近づいた時に作動していた冷媒ポンプ９０を停止し、第３弁１５３は使用しないか、予め設けず、第４弁１５４は全開とし、吸収液ポンプを運転して、高温に加熱された吸収液を蒸発器管に散布する場合もある。
【００５７】
排ガス温度センサ１２４で検知される温度がドレン発生温度以下の場合、第２弁１５２を全閉、第３弁１５３を全開、第４弁１５４を全開とし、かつ、冷媒ポンプ９０を停止するとともに吸収液ポンプを運転して、冷暖切替弁（第１弁）１５１から流入する冷媒蒸気、冷媒蒸気ドレンのみを蒸発器管に散布して、伝熱管内を流れる温水と熱交換させる。このため、温水温度はあまり上げられない。この場合、吸収冷温水機内を循環する吸収液の温度を全体に上げる必要があるので、効率が若干下がる。しかし、排ガス熱交換器１２０内の伝熱管を凝縮水の腐食から守るという目的には十分な効果がある。
【００５８】
これらの方法において、第４弁１５４を使用しないか、予め設けないように構成することもできる。
また、排ガス温度センサ１２４で検知される温度がドレン発生温度以下にならないように、第４弁１５４の開度を調節して排ガス熱交換器１２０へ循環する吸収液量をコントロールすることもできる。
この方法において、排ガス熱交換器１２０へ循環する吸収液の流動が止まらないように第４弁１５４を流れる液の一部をバイパスさせる。１６４はバイパス管で、全量バイパスとならないようにオリフィスが設けられる。
【００５９】
これらの方法において、蒸発器８９へ循環する吸収液の流動が止まらないように第２弁１５２を流れる液の一部をバイパスさせることがある。この場合も、バイパス管には、全量バイパスとならないようにオリフィスが設けられる。
また、これらの方法において、吸収冷温水機の燃焼量を、冷温水温度センサ１０２で感知した温度が予め設定した温度に対してずれた時に増減コントロールすることがある。なお、冷暖切替弁（第１弁）１５１、第２弁１５２、第３弁１５３、第４弁１５４の開度により燃焼量をコントロールするものではない。
また、これらの方法において、高温再生器１０に設けられた液面検出・制御装置４４により、高温再生器１０の液面を制御して液面低下を防止するように構成することが好ましい。
【００６０】
図２は、本発明の実施の第２形態による制御方法を実施する吸収冷温水機を示している。本実施形態は、排ガス温度センサで排ガス温度を検知して制御する代りに、排ガス熱交換器１２０の伝熱管又は該伝熱管の出口に吸収液温度センサ１６６を設け、この吸収液温度センサ１６６で排ガス熱交換器１２０内を流れる吸収液温度を検知して制御するように構成したものである。吸収液温度は、例えば８０℃で制御される。他の構成及び作用は、実施の第１形態の場合と同様である。
【００６１】
【発明の効果】
本発明は上記のように構成されているので、つぎのような効果を奏する。
（１）暖房運転中、冷媒に吸収液を混入させ、この混合液を蒸発器の伝熱管に散布し伝熱管内を通る温水と熱交換させることにより、吸収液温度が低下し、それによって吸収液と熱交換する排ガス温度も低下する。このため、暖房運転時の熱回収量が増えて暖房効率が向上する。
（２）貫流方式ボイラ又は貫流方式ボイラと同等の構造を持つ高温再生器、中温再生器、低温再生器、凝縮器、吸収器、蒸発器、熱交換器類、溶液ポンプ、冷媒ポンプ、冷暖切替弁及び排ガス熱交換器を有する三重効用吸収冷温水機において、暖房運転時に負荷側に供給する温水温度に悪影響を与えることなく、また、効率低下を招くことなく制御するように吸収液の流量を制御する制御弁を設けて制御するので、排ガス温度の低下防止及びドレンの発生を防止して伝熱管の腐食を防止することができる。
（３）負荷（温水）の温度変化によって燃焼装置の燃焼量（加熱量）を増減するのと同時に、排ガス熱交換器出口部の排ガス温度又は排ガス熱交換器の伝熱管の吸収液温度によって、燃焼量ではなく吸収液循環量を制御する制御機能を設け、負荷の変動により冷温水温度センサからの制御信号で燃焼量を制御しているので、燃焼量が増えれば循環する吸収液温度が上がり、排ガス熱交換器を通過する排ガスの温度が上がり、凝縮ドレン発生のおそれはないが、燃焼量が減り、循環する吸収液温度が下がれば、排ガス熱交換器を通過する排ガスの温度も下がり、凝縮ドレンが発生して伝熱管に悪影響を与える。この時、燃焼量を制御すると負荷側に供給する温水温度に悪影響を与えると同時に効率も低下することになるので、吸収液が循環する配管途中に制御弁を設け吸収液循環量の制御又は循環する経路を切り換えることで、ドレンの発生を防止し伝熱管の腐食を防止することができる。
【図面の簡単な説明】
【図１】本発明の実施の第１形態による制御方法を実施する吸収冷温水機の系統的概略構成図である。
【図２】本発明の実施の第２形態による制御方法を実施する吸収冷温水機の系統的概略構成図である。
【図３】本出願人が開発している吸収冷温水機の系統的概略構成図である。
【図４】従来の吸収式冷凍機の一例を示す系統的概略構成図である。
【符号の説明】
１０高温再生器
１２上部管寄せ
１４下部管寄せ
１６上昇管
１８燃焼装置
２０燃焼室
２４気液混合物導管
２６気液分離器
２８蒸気抜出導管（蒸気供給管）
３０吸収液抜出導管
３６吸収液循環導管
４２吸収液供給管（水・吸収液供給管）
４４液面検出・制御装置
４６空缶防止用の吸収液温度センサ
８１吸収器
８２稀液ポンプ（低温吸収液ポンプ）
８３低温熱交換器
８４低温再生器
８５中間液ポンプ（高温吸収液ポンプ）
８６高温熱交換器
８７中温再生器
８８凝縮器
８９蒸発器
９０冷媒ポンプ
９３吸収液ポンプ（水・吸収液供給ポンプ）
９４付加熱交換器
９５、９６バイパス管
９７、９８冷媒蒸気配管
９９冷温水ポンプ
１００冷却水ポンプ
１０２冷温水温度センサ
１０４蒸気ドレン温度センサ
１１２吸収液温度センサ
１１４運転制御・安全制御用運転盤
１１６蒸気温度センサ
１１８圧力計（圧力センサ）
１２０排ガス熱交換器
１２２排ガス通路
１２４排ガス温度センサ
１５１冷暖切替弁（第１弁）
１５２第２弁
１５３第３弁
１５４第４弁
１５６加熱側の吸収液配管
１５８蒸発器用吸収液供給管
１６０帰還吸収液管
１６２排ガス熱交換器用吸収液供給管
１６４バイパス管
１６６吸収液温度センサ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for controlling the heating operation of a triple effect absorption chiller / heater, and more particularly, to a triple effect absorption chiller / heater in which the amount of heat recovered during the heating operation is increased, the heating efficiency is improved, and the corrosion of the heat transfer tube is prevented. The present invention relates to a heating operation control method for a water machine.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a steam-type double effect absorption refrigerator as illustrated in FIG. 4 has been known. This absorption refrigerator constitutes a reverse cycle in which an absorption liquid (for example, an aqueous solution of lithium bromide) flows from an absorber a through a low-temperature regenerator c to a high-temperature regenerator e. The absorption cycle in this absorption refrigerator will be described. First, an absorption liquid (dilute absorption liquid) whose concentration has been reduced by absorbing a large amount of refrigerant vapor in the absorber a is sent from the absorber a to the low-temperature heat exchanger b. After being heated by the low-temperature heat exchanger b, it is sent to the low-temperature regenerator c. The rare absorbing liquid is regenerated at a low temperature in the low-temperature regenerator c, releases a part of the absorbed refrigerant, and its concentration is increased by that amount to become an intermediate concentration absorbing liquid (intermediate absorbing liquid). Next, the intermediate absorbent is sent from the low-temperature regenerator c to the high-temperature heat exchanger d, and is heated by the high-temperature heat exchanger d and then sent to the high-temperature regenerator e.
[0003]
The intermediate absorbent is regenerated at a high temperature in the high-temperature regenerator e and releases a part of the absorbed refrigerant (for example, water vapor) to further increase the concentration to become a high-concentration absorbent (concentrated absorbent). . Then, the concentrated absorbent is returned to the heating side of the high-temperature heat exchanger d as a heating source for heating the intermediate absorbent, and further, a heating source for heating the rare absorbent to the heating side of the low-temperature heat exchanger b. Is returned to the absorber a. The returned concentrated absorbent is sprayed on the heat transfer tube in the absorber a, and absorbs the refrigerant vapor again while being cooled by the cooling water to become the rare absorbent.
[0004]
In such a steam-type double effect absorption refrigerator, high-temperature steam (steam) is supplied as a heating source from a steam boiler f to the high-temperature regenerator e. Is heated to release the absorbed refrigerant, and the released refrigerant vapor is used by the low-temperature regenerator c as a heating source in the low-temperature regenerator c, and then returned to the condenser g to be condensed. . Refrigerant liquid (for example, water) from the condenser g enters the evaporator h, and the condensed refrigerant liquid is sprayed on a heat transfer tube (where water is flowing) of the evaporator h by a refrigerant pump and cooled by evaporative latent heat. To obtain cold water.
Further, a bypass pipe k is provided for connecting the absorbent pipe i from the low-temperature regenerator c and the absorbent pipe j on the heating side between the high-temperature heat exchanger d and the low-temperature heat exchanger b. A part of the intermediate concentrated absorbing liquid that exits c and is supplied to the high-temperature regenerator e is bypassed to the concentrated absorbing liquid pipe returning to the absorber a.
[0005]
Normally, when operating a boiler alone, the control is to detect the steam pressure change at the boiler outlet that changes due to an external load change, and control the amount of combustion so that the steam pressure falls within a predetermined pressure range. ing. During operation, the water level is controlled by controlling the start and stop of the water supply pump so that the water retained in the boiler falls within a predetermined water level range.
On the other hand, in a conventional absorption refrigerator as shown in FIG. 4, a change in chilled water temperature at a refrigerator outlet or an inlet, which is changed by a change in external load, is detected, and the temperature at the refrigerator outlet or an inlet is determined. The amount of the supplied heat source is controlled so as to reach the specified temperature.
[0006]
The above-mentioned boiler and absorption chiller have an operation system such as interlocking and interlocking operation. However, the normal operation system has independent control. A boiler corresponds to a pressure vessel whose internal pressure exceeds atmospheric pressure, and an absorption refrigerator corresponds to a vacuum vessel whose internal pressure is lower than atmospheric pressure. For this reason, conventionally, it has been impossible to drive and control the two together as impossible.
However, due to environmental issues and the like, there is a demand for the development of a chiller / heater that further saves energy, and the chiller / heater of the present invention developed this time meets the demands of the times.
The absorption refrigerator has, for example, a lithium bromide aqueous solution as a medium that circulates inside and exchanges heat energy. It is generally called an absorbing liquid, and is configured to exhibit a cooling effect by absorbing and evaporating water serving as a refrigerant.
Japanese Patent Application Laid-Open No. 2000-171123 discloses a high-temperature regenerator, a medium-temperature regenerator, a low-temperature regenerator, a condenser, an absorber, an evaporator, a heat exchanger, a solution pump, and a refrigerant pump as main components. In a triple-effect absorption refrigerator connected by a solution pipe and a refrigerant pipe, a pressure sensor is provided in the high-temperature regenerator and a liquid level sensor is provided at an outlet of the high-temperature regenerator, and an absorber is provided based on an output of the pressure sensor. Describes a triple effect absorption refrigerator having a solution pump rotation speed control device that sets a basic rotation speed of a solution pump that sends a solution to a high-temperature regenerator from the device, and corrects the fixed rotation speed with the liquid level sensor. .
[0007]
Japanese Patent No. 3215247 discloses a method for extracting hot water from an absorption chiller / heater, extracting an absorption liquid from a primary side, which is an inlet side of a low-temperature heat exchanger, and supplying the absorption liquid to a liquid pool of an evaporator. High-temperature hot water in an absorption chiller / heater including a process of spraying the absorbing liquid on the surface of the heat transfer tube of the evaporator and a process of heating the hot water in the heat transfer tube of the evaporator with the absorbing liquid to lower the temperature of the absorbing solution. The method of taking out is described.
Japanese Patent Publication No. 6-46122 discloses a high-temperature regenerator equipped with a heating device in addition to an absorber, a condenser, an evaporator, and a low-temperature regenerator. In an absorption refrigerator including a reverse-flow absorption heat pump leading to a high-temperature regenerator, the fact that the load was low and the heat-collecting surface and exhaust gas temperature of the high-temperature regenerator were undesirably reduced, When detected by a sensor or a pressure sensor provided in the gas-liquid separator into which the absorbing liquid is introduced from the high-temperature regenerator, the amount of the absorbing liquid introduced from the low-temperature regenerator to the high-temperature regenerator is detected from the low-temperature regenerator. The flow rate is controlled by a flow control valve or a variable displacement type absorption liquid pump provided in a pipe for introducing the absorption liquid into the high temperature regenerator, and the pressure in the high temperature regenerator is increased to increase the pressure in the high temperature regenerator. Raising the temperature of the heating surface, the control method of raising the exhaust gas temperature double effect absorption refrigerating machine capable of preventing the condensation of flue gas in the heat absorption surface of the high-temperature regenerator is described.
[0008]
[Problems to be solved by the invention]
The conventional steam absorption refrigerator combined with the steam boiler f as shown in FIG. 4 has the following disadvantages.
The steam boiler f itself is large, which leads to an increase in the size of the entire absorption refrigerator. In addition, in order to operate the steam boiler f, it is necessary to supply water in a system different from the absorption chiller system, collect steam drain after heating, and inject chemicals. In addition, additional equipment for them is required, which is helping to increase the size of the apparatus. However, the contribution of the steam boiler f to the absorption refrigerator is merely to supply the heating source, and the effect corresponding to the fuel consumption for combustion in the steam boiler f is sufficiently obtained. It is hard to say that it is. In addition, legal regulations also involve the inconvenience of requiring a predetermined qualified person, inspection, and the like as a handler.
[0009]
In order to integrate the absorption chiller and boiler for stable operation, combine the safety device required as a boiler and the chilled water temperature control device required as an absorption chiller so that stable and safe operation can be continued. Need to be
When the operation is performed by integrating the absorption refrigerator and the boiler, the control of the steam pressure is not a very important condition. Rather, it is important to stably supply the cold water temperature required for the absorption refrigerator, and it is important to sufficiently control the heating source so that the cold water temperature can be stably supplied.
On the other hand, in the boiler, the absorption chiller changes the chilled water temperature due to changes in load, etc., and outputs a signal to control the amount of heating source. It must be controlled so that it can be driven.
[0010]
Therefore, if the chilled water temperature control of the absorption chiller and the combustion amount control of the boiler are paired, the change in the steam pressure and the water level of the boiler are separately detected, and the rotation speed of the absorption pump installed in the absorption chiller is detected. Control system to control the amount of circulation of the absorbing liquid by controlling the amount of absorption liquid, and perform control to reduce the influence during operation of the boiler. Safe combustion control and stable chilled water temperature control as an absorption refrigerator become possible.
As the control for this, an important requirement is to control the rotational speed of the absorbent pump by detecting the steam temperature or pressure, or to control the rotational speed of the absorbent pump by detecting the operating liquid level.
However, at that time, a safety valve, a low-water combustion shut-off device, and a water supply device required for a boiler must be provided.
In the triple effect absorption refrigerator described in JP-A-2000-171123, control for changing the frequency for each pump is not performed. Also, there is no bypass circuit that branches off from the pump suction port and returns to the return pipe. Further, this publication does not describe anything about combining and integrating a boiler such as a once-through boiler with an absorption refrigerator.
[0011]
As shown in the above-mentioned Japanese Patent No. 3215247, an absorbing liquid obtained by mixing an absorbing liquid and a refrigerant is sprayed on an evaporator tube in an evaporator, and the temperature of circulating water flowing in the evaporator tube is increased to perform a heating operation. Absorption chillers and hot water heaters for supplying hot water for heating building air conditioners and the like are well known.
FIG. 3 shows a triple effect absorption chiller / heater developed by the present applicant in a manner using the same example of the heating operation already performed in the double effect type. A structure is shown in which refrigerant vapor generated by the low-temperature regenerator 84 is blown to the evaporator 89, and when the refrigerant vapor condenses, heat exchanges with hot water to raise the temperature of the hot water. Reference numeral 151 denotes a cooling / heating switching valve that opens during a heating operation and closes during a cooling operation. 10 is a high temperature regenerator, 81 is an absorber, 87 is a medium temperature regenerator, and 88 is a condenser.
Further, in order to increase the efficiency by exchanging heat between a part of the absorbent or the combustion air and the combustion exhaust gas, the device may be provided with an exhaust gas heat exchanger (or an air heater).
In any case, the operation is planned for the purpose of operating efficiently and reducing fuel consumption, and the effect is also achieved. In addition, a device and a device for more efficiently recovering heat by changing the position where the heat exchanger is mounted have been developed. However, it does not mention the problems that occur when the vehicle is actually driven, and does not discuss specific problems and countermeasures.
[0012]
During actual operation, various problems such as load changes due to the influence of the external environment occur. There is no problem when operating under the rated condition, but when the operation becomes low load, the cycle condition temperature of each part is lower than at the time of the rated operation because control is added to the operating condition. Also, no countermeasures have been taken for the problems that occur when the temperature drops, resulting in corrosion that can develop into a serious problem.
Specifically, when the amount of combustion is controlled in the absorption refrigerator due to a change in load or the like, there is a problem caused by a decrease in the exhaust gas temperature at the outlet of the exhaust gas heat exchanger caused by a decrease in the solution circulation temperature of each section.
If the temperature of the exhaust gas is reduced, for example, to 100 ° C. or less, the water vapor in the exhaust gas condenses to form a drain. If the water vapor in the exhaust gas condenses in the exhaust gas heat exchanger, the sulfur contained in the exhaust gas Oxides and carbon dioxide in the air dissolve together in the condensed water to form a corrosive aqueous solution, which violently corrodes the heat transfer tube surface of the exhaust gas heat exchanger. The temperature of the absorbing liquid flowing in the tube drops to about 80 ° C.
If the absorbing liquid is guided to the evaporator and the absorbing liquid is sprayed to the evaporator heat transfer tube by the refrigerant pump, it is more efficient than the conventional method, and it is possible to obtain high-temperature heating hot water. There are examples.
However, in the past examples, each of them has a single or fixed opening and closing of the valve, and does not satisfy both efficiency improvement and prevention of condensation drain generation at the same time, and generation of condensation drain is unavoidable for efficiency improvement They give up on things and deal with heat exchangers using high-grade materials.
The present invention provides a countermeasure for solving the problem, and performs a control that does not cause a problem that is an obstacle in continuously operating the water heater / heater.
[0013]
The present invention has been made in view of the above points, and an object of the present invention is to use a once-through type boiler as a high-temperature regenerator, integrate this boiler and an absorption refrigerator, and cause an abnormality in these devices on the boiler side. In this case, it is possible to provide a heating operation control method for an energy-saving absorption chiller / heater that is capable of continuous operation and that incorporates a control circuit that safely stops the absorption chiller in conjunction with the boiler combustion cutoff. is there.
That is, an object of the present invention is a once-through boiler or a high-temperature regenerator having a structure equivalent to a once-through boiler, a medium-temperature regenerator, a low-temperature regenerator, a condenser, an absorber, an evaporator, a heat exchanger, a solution pump, A triple effect absorption chiller / heater having a refrigerant pump, a cooling / heating switching valve, and an exhaust gas heat exchanger is configured.The chiller / heater does not adversely affect the temperature of hot water supplied to the load side during the heating operation, and reduces the efficiency. A safety valve that has a control valve that controls the flow rate of the absorbing liquid so that it does not invite the heat, prevents the exhaust gas temperature from dropping below a predetermined temperature, prevents the generation of drainage, and prevents corrosion of the heat transfer tube. Another object of the present invention is to provide a control method for a triple effect absorption chiller / heater equipped with a control device during a heating operation.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, a heating operation control method for a triple effect absorption chiller / heater according to the present invention uses a once-through boiler or a boiler having a structure equivalent to that of a once-through boiler as a high-temperature regenerator. A triple-effect absorption chiller / heater that integrates with a heat pump, a high-temperature regenerator, a medium-temperature regenerator, a low-temperature regenerator, a condenser, an absorber, an evaporator, a heat exchanger, a solution pump, a refrigerant pump, and a cooling / heating switching valve ( A reverse flow type triple effect absorption chiller / heater which has a first valve) and an exhaust gas heat exchanger, and guides the absorbent in the absorber from the low temperature regenerator to the medium temperature regenerator and then to the high temperature regenerator. A temperature sensor detects a temperature change on the load side and detects the change in the temperature (fuel, gas, oil, waste heat) supplied to the boiler by a control signal from an operation panel for operation control and safety control (hereinafter referred to as an operation panel). ) To increase or decrease the amount of combustion The operation of the boiler is reduced and the absorption pumps of the absorption refrigerator are operated at the same time, and the absorption liquid having a different water content is supplied (circulated) stably to enable continuous operation. It has a pipe for circulating and flowing the liquid, and has a pipe that branches off a part of the absorbent flowing into the absorbent pump that supplies the liquid from the low-temperature regenerator to the higher-level regenerator and bypasses it to the return pipe. There is a pipe that branches a part of the liquid flowing into the water / absorbent liquid supply pump from the regenerator and bypasses it to the return pipe to adjust the supply amount (circulation amount) of the water / absorbent liquid (absorbent liquid). By adjusting the power load applied to the pump, energy saving and stable continuous operation can be performed. An exhaust gas heat exchanger is installed in the exhaust gas passage of the high-temperature regenerator. Drain some of the liquid from the absorbent pump that supplies liquid to the The exhaust gas is introduced through an absorption liquid supply pipe for a heat exchanger and heated by exhaust gas. An exhaust gas temperature sensor is provided in an exhaust gas passage at an outlet of the exhaust gas heat exchanger, and the exhaust gas temperature sensor and the operation control / safety control operation are provided. In conjunction with the board, further connected to the absorption liquid pipe on the heating side between the high-temperature heat exchanger and the low-temperature heat exchanger, an evaporator absorption liquid supply pipe for introducing the absorption liquid into the evaporator, A second valve is provided in the absorption liquid supply pipe for the evaporator, a third valve is provided in the return absorption liquid pipe to the absorber, a fourth valve is provided in the absorption liquid supply pipe for the exhaust gas heat exchanger, and a bypass is provided in the fourth valve. In a triple effect absorption chiller / heater connected to a pipe, at least one of the second valve, the third valve and the fourth valve is used alone or so that the exhaust gas temperature detected by the exhaust gas temperature sensor does not become lower than the drain generation temperature. Simultaneously control and cool the evaporator The start and stop of the medium pump are controlled to prevent the generation of condensed water in the exhaust gas heat exchanger.
[0015]
In this control method, when the temperature detected by the exhaust gas temperature sensor exceeds the drain generation temperature, the second valve is fully opened, the third valve is fully closed, the fourth valve is fully opened, and the refrigerant pump is operated and absorbed. The liquid pump is operated to spray the absorbing liquid heated to a high temperature to the evaporator tube.
[0016]
Further, when the temperature detected by the exhaust gas temperature sensor exceeds the drain generation temperature, the second valve is automatically controlled between the fully closed state and the fully opened state, and the refrigerant pump that was operating when the second valve was almost fully closed is activated. The operation is stopped, the third valve is not used or is not provided in advance, the fourth valve is fully opened, and the absorbent pump is operated to spray the high-temperature heated absorbent to the evaporator tube.
[0017]
When the temperature detected by the exhaust gas temperature sensor is equal to or lower than the drain generation temperature, the second valve is fully closed, the third valve is fully opened, the fourth valve is fully opened, and the refrigerant pump is stopped and the absorbing liquid pump is turned off. By operating, only the refrigerant vapor and the refrigerant vapor drain flowing from the cooling / heating switching valve are sprayed on the evaporator tube to exchange heat with the hot water flowing in the heat transfer tube.
[0018]
In these control methods, the fourth valve may not be used or may not be provided in advance.
In some cases, the opening degree of the fourth valve is adjusted to control the amount of the absorbent circulating to the exhaust gas heat exchanger so that the temperature detected by the exhaust gas temperature sensor does not become lower than the drain generation temperature.
[0019]
Instead of detecting and controlling the exhaust gas temperature with an exhaust gas temperature sensor, an exhaust gas heat exchanger heat transfer pipe or an absorbent temperature sensor is provided at the outlet of the heat transfer pipe, and the absorbent flowing through the exhaust gas heat exchanger with the absorbent temperature sensor is used. In some cases, control is performed by detecting the temperature (see FIG. 2).
[0020]
When the fourth valve is used, a part of the liquid flowing through the fourth valve is bypassed so that the flow of the absorbent circulating to the exhaust gas heat exchanger does not stop.
In these control methods, it is preferable that a part of the liquid flowing through the second valve is bypassed so that the flow of the absorbing liquid circulating to the evaporator does not stop.
Further, it is preferable that the amount of combustion of the absorption chiller / heater is increased or decreased when the temperature detected by the chilled / hot water temperature sensor deviates from a preset temperature.
Further, it is preferable that a liquid level detection / control device is provided in the high temperature regenerator to control the liquid level of the high temperature regenerator to prevent the liquid level from lowering.
[0021]
In these water heaters, the amount of heat (the amount of heating) of the combustion device is increased or decreased by the temperature change of the load (the amount of water), and at the same time, the steam pressure inside the boiler rises and the temperature rises. If the temperature detected by the steam drain temperature sensor at the outlet of the intermediate temperature regenerator of the absorption refrigerator rises, the rotation speed of the absorption liquid supply pump is increased for safety, and the amount of liquid circulation is increased, resulting in the Pressure, and if the drain temperature drops, reduce the number of revolutions of the absorption liquid supply pump to reduce the amount of liquid circulation and increase the vapor pressure, ensuring stable operation in a temperature and pressure range suitable for continuous operation. It is configured to have a control function that can be continued.
[0022]
Also, at the same time as the amount of heat (heated amount) of the combustion device is increased or decreased by the temperature change of the load (cold / hot water), the steam pressure inside the boiler rises and the temperature rises, and is detected in the steam pipe at the boiler outlet. If the vapor pressure or the temperature detected by the temperature sensor rises, increase the number of revolutions of the absorption liquid supply pump to increase the liquid circulation for safety, and reduce the vapor pressure as a result. Alternatively, if the temperature decreases, the number of revolutions of the absorption liquid supply pump is reduced to reduce the amount of liquid circulation and increase the vapor pressure, so that stable operation can be continued in a temperature range and pressure range suitable for continuous operation. Configure to have functions.
[0023]
In these water heaters, the liquid level during operation of the boiler is detected by a liquid level detecting device, and when the liquid level rises, the number of rotations of the pump is reduced, and the liquid circulation amount is reduced to lower the liquid level. If the liquid level drops, the pump speed is increased to increase the liquid circulation rate and control so that the liquid level rises.If the operating liquid level drops further below the lower limit set value for safe operation, Has a safety control function that issues an alarm, shuts off combustion, and enters a safe stop operation.
In addition, when detecting the steam drain temperature, steam temperature, steam pressure or the operating liquid level of the boiler during operation and controlling the rotation speed of the pump, the control is performed by a low-temperature absorbent pump, a high-temperature absorbent pump, Switch one or more of the operation methods selected from the operation method selected from the combination such as only two pumps of the low-temperature absorption liquid pump and the water / absorption liquid supply pump simultaneously or independently, or each pump of the liquid supply pump In such a way, the number of revolutions is controlled to control the supply amount (circulation amount) of the absorbing liquid containing water so as to enhance the operation efficiency, and each pump causes a shortage of the supply amount (circulation amount) and a shortage of the head. It is configured to perform control so as to ensure a rotation speed that is not high.
[0024]
In these chillers, when the supply device for supplying water and absorbing liquid to the boiler fails during operation and the supply amount decreases, the amount of water and absorbing liquid held inside the boiler decreases. Therefore, a safety control function is set up so that a warning is issued and combustion is cut off at the same time to start a safe stop operation.
Also, if the water / absorbent liquid supply to the boiler decreases during operation, or if the water / absorbent liquid amount held inside the boiler decreases and the temperature of each part exceeds the set value for safe operation, In addition, a safety control function is provided in which an alarm is issued by an absorption liquid temperature sensor or an empty can prevention absorption liquid temperature sensor provided in the boiler, and at the same time, the combustion is cut off and a safe stop operation is started.
[0025]
Furthermore, the gas and liquid which distribute the steam and the absorbing liquid so that the boiler can continuously operate by separating the heated and evaporated steam, the absorbing liquid which did not evaporate, and the absorbing liquid containing the water recirculated to the boiler. The boiler is provided with a separator.
[0026]
In the above-mentioned absorption chiller / heater, the temperature change on the load side is detected from the chilled / hot water temperature sensor, and the temperature change is detected by the fuel (supplied to the boiler by the control signal from the operation control and safety control operation panel (operation panel)). (Gas, oil, waste heat) to increase or decrease the amount of combustion in the combustion device to operate the boiler efficiently, and at the same time to operate the absorption pumps of the absorption chiller to absorb different water contents The liquid is stably supplied (circulated) to enable continuous operation, and a part of the absorbent flowing into the absorbent pump that supplies the liquid from the low-temperature regenerator to the higher-level regenerator is branched and bypassed to the return pipe. At the same time, a part of the liquid flowing into the water / absorbent supply pump from the intermediate temperature regenerator is branched and bypassed to the return pipe, and the supply amount (circulation amount) of the water / absorbent (absorbent) is adjusted, and the pump is adjusted. By adjusting the power load applied to The continuous operation.
[0027]
In this method, the amount of heat (heated amount) of the combustion device is increased or decreased by the temperature change of the load (cold / hot water), and at the same time, the steam pressure inside the boiler rises and the temperature rises, and the absorption refrigeration heated by steam If the temperature detected by the steam drain temperature sensor at the outlet of the high-temperature regenerator of the unit rises, increase the number of revolutions of the absorption liquid supply pump and increase the amount of liquid circulation for safety, thereby reducing the vapor pressure. If the drain temperature drops, reduce the rotation speed of the absorption liquid supply pump, reduce the amount of liquid circulation, increase the vapor pressure, and control so that stable operation can be continued in the temperature range and pressure range suitable for continuous operation. To be configured.
[0028]
Also, at the same time as the amount of heat (heated amount) of the combustion device is increased or decreased by the temperature change of the load (cold / hot water), the steam pressure inside the boiler rises and the temperature rises, and is detected in the steam pipe at the boiler outlet. If the vapor pressure or the temperature detected by the temperature sensor rises, increase the number of revolutions of the absorption liquid supply pump to increase the liquid circulation for safety, and thus reduce the vapor pressure, and thereby increase the vapor pressure or temperature. If the pressure drops, reduce the number of revolutions of the absorption liquid supply pump, reduce the amount of liquid circulation, increase the vapor pressure, and control so that stable operation can be continued in the temperature range and pressure range suitable for continuous operation. .
[0029]
In these methods, the liquid level during operation of the boiler is detected by a liquid level detecting device, and when the liquid level rises, the number of rotations of the pump is reduced, the liquid circulation amount is reduced, and the liquid level is lowered. If the operating fluid level falls below the lower limit set value for safe operation, a warning is issued if the operating fluid level falls further below the lower limit set value for safe operation. Control is performed so as to shut off combustion and enter a safe stop operation.
[0030]
In this method, the liquid level during operation of the boiler is detected by a liquid level detection device, and as a method of controlling the number of rotations of the pump, the operating conditions and a control signal are received, and the number of rotations is gradually changed to a predetermined number of rotations. As a method of using a step control method to make it possible to operate, or as a method of detecting the liquid level during operation of the boiler with a liquid level detection device and controlling the rotation speed of the pump, operating conditions, load signal, control signal In response to this, a method of using a continuous control formula in which the number of revolutions is continuously changed is adopted.
[0031]
In these methods, when detecting the steam drain temperature during operation, the steam temperature, the steam pressure or the operating liquid level of the boiler and controlling the rotation speed of the pump, the control is performed by a low-temperature absorbent pump, a high-temperature absorbent pump, One or a plurality of water / absorbent supply pumps can be operated simultaneously or independently, or one or a plurality of operation methods selected from a combination of low temperature absorbent pumps and only two water / absorbent supply pumps. The system can be switched so that the number of rotations is controlled to control the supply (circulation) of the water-containing absorbing liquid to increase the operating efficiency, and that each pump has a shortage of supply (circulation) and shortage of head. Control to ensure that there is no rotational speed.
[0032]
In these methods, during operation, when the supply device for supplying water / absorbent to the boiler breaks down and the supply amount decreases, the amount of water / absorbent retained inside the boiler decreases and the Since the operation is hindered, an alarm is issued and at the same time, the combustion is cut off, and control is performed so as to start a safe stop operation.
Also, if the water / absorbent liquid supply to the boiler decreases during operation, or if the water / absorbent liquid amount held inside the boiler decreases and the temperature of each part exceeds the set value for safe operation, An alarm is issued by an absorption liquid temperature sensor or an empty can prevention absorption liquid temperature sensor provided in the boiler, and at the same time, the combustion is cut off and the safety stop operation is started.
[0033]
In these methods, as a boiler, steam and absorption liquid are distributed so that continuous operation can be performed by separating steam that has been heated and evaporated, absorption liquid that has not evaporated, and absorption liquid containing water that is recirculated to the boiler. It is configured to use a boiler provided with a gas-liquid separator.
[0034]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications. FIG. 1 shows an absorption chiller / heater for implementing a control method according to a first embodiment of the present invention. As the high-temperature regenerator, a once-through boiler or a boiler having the same function and structure as this is used. In the present embodiment, a case of using a once-through boiler type as the high-temperature regenerator is shown. Reference numeral 10 denotes a high-temperature regenerator having a once-through boiler structure, which has annular upper headers (upper headers) 12 and lower headers (lower headers) 14 at upper and lower portions, and a vertical direction is provided between these headers 12 and 14. Is disposed in a substantially cylindrical shape, and has a combustion device 18, for example, a burner in the upper central portion, introduces the dilute absorbent into the lower header 14, heats it and concentrates it, and starts from the upper header 12. It is configured so that the gas-liquid mixture can be taken out. 20 is a combustion chamber.
[0035]
A gas-liquid separator 26 is connected to the high-temperature regenerator 10 via a gas-liquid mixture conduit 24. A vapor extraction conduit 28 is connected to an upper portion of the gas-liquid separator 26, and an absorption liquid extraction conduit 30 is connected to a lower portion of the gas-liquid separator 26.
The lower part of the gas-liquid separator 26 and the lower header 14 of the high-temperature regenerator 10 are connected via an absorbent circulation pipe 36. An absorption liquid supply pipe 42 is connected to the absorption liquid circulation conduit 36 or the lower header 14. Reference numeral 44 denotes a liquid level detection / control device of the gas-liquid separator 26. On the lower surface or side surface of the lower header 14, an absorbent temperature sensor 46 for preventing empty cans is provided.
[0036]
In this embodiment, an absorber 81, a pump (dilute liquid pump) 82, a low-temperature heat exchanger 83, a low-temperature regenerator 84, a pump (intermediate liquid pump) 85, a high-temperature heat exchanger 86, a medium-temperature regenerator 87, and a condenser 88 , An evaporator 89, a refrigerant pump 90 and a reverse cycle type double-effect absorption refrigerator having components such as an absorption liquid pipe, a refrigerant pipe, and the like connecting these devices. And a water / absorbent supply pump 93 as a solution supply means, an additional heat exchanger 94, and the like. In FIG. 1, the arrows attached to the solid lines indicate the flow directions of the absorbing liquid, the refrigerant liquid or the water, and the arrows attached to the broken lines indicate the flow directions of the refrigerant vapor or the mixture of the refrigerant vapor and the condensed refrigerant (refrigerant drain). Is shown.
[0037]
Reference numeral 95 denotes a first bypass pipe for bypassing a part of the absorbent from the low-temperature regenerator 84 to the concentrated absorbent pipe from the high-temperature heat exchanger 86. Reference numeral 96 denotes a second bypass pipe for bypassing a part of the absorbent from the intermediate-temperature regenerator 87 to the return concentrated absorbent pipe from the additional heat exchanger 94. 99 is a cooling / heating water pump, 100 is a cooling water pump, 151 is a cooling / heating switching valve (first valve), which is fully opened during the heating operation and fully closed during the cooling operation. Note that another concentrator can be provided between the intermediate temperature regenerator 87 and the high temperature regenerator 10.
[0038]
Next, in the absorption refrigerator configured as described above, the circulation cycle of the absorption liquid will be described in order. First, a diluted absorption liquid whose concentration has been reduced by absorbing a large amount of refrigerant vapor in the absorber 81 is sent from the absorber 81 to the low-temperature heat exchanger 83 by the diluted liquid pump 82, and the low-temperature heat exchanger 83 After being heated, it is sent to the low-temperature regenerator 84. Then, the rare absorbing liquid is regenerated at a low temperature in the low-temperature regenerator 84, and a part of the absorbed refrigerant is released and the concentration is increased by that amount to become an intermediate-concentration intermediate absorbing liquid.
[0039]
Most of the intermediate concentrated absorption liquid is sent from the low temperature regenerator 84 to the high temperature heat exchanger 86 by the intermediate absorption liquid pump 85, and after being heated by the high temperature heat exchanger 86, is sent to the medium temperature regenerator 87. You. The intermediate concentrated absorbent is regenerated at a high temperature in the intermediate-temperature regenerator 87, and releases part of the absorbed refrigerant to further increase the concentration to become a high-concentration concentrated absorbent.
The remainder of the intermediate concentrated absorption liquid from the low-temperature regenerator 84 is supplied to the concentrated absorption liquid piping returning to the absorber 81 by bypass through a bypass pipe 95.
[0040]
Part or all of the concentrated absorbent from the intermediate temperature regenerator 87 is supplied to the additional heat exchanger 94 by the absorbent pump 93, where it is heated by exchanging heat with the concentrated absorbent from the high temperature regenerator 10. After that, it is supplied to the high-temperature regenerator 10. The remaining part (may be zero) of the concentrated absorbent from the intermediate temperature regenerator 87 joins the absorbent pipe on the heating side from the additional heat exchanger 94 via the second bypass pipe 96.
[0041]
In the high-temperature regenerator 10, the concentrated absorbent heated and concentrated by the heat of combustion of the fuel is introduced to the heating side of the additional heat exchanger 94 to heat the concentrated absorbent from the intermediate-temperature regenerator 87, and then the high-temperature heat exchanger 86 is introduced to the heating side. The remaining part (may be zero) of the concentrated absorbent from the intermediate temperature regenerator 87 joins the absorbent pipe on the heating side from the additional heat exchanger 94 via the second bypass pipe 96.
The refrigerant vapor from the high-temperature regenerator 10 is introduced into the intermediate-temperature regenerator 87 via the vapor extraction conduit 28, where the absorbing liquid is heated and concentrated, and then the refrigerant drain is introduced into the low-temperature regenerator 84.
[0042]
The refrigerant vapor from the intermediate-temperature regenerator 87 is sent to the low-temperature regenerator 84 together with the refrigerant drain from the intermediate-temperature regenerator 87 via the refrigerant vapor pipe 97, where the absorption liquid is heated and concentrated.
The refrigerant vapor from the low-temperature regenerator 84 is introduced into the condenser 88 via the refrigerant vapor pipe 98 together with the refrigerant drain from the low-temperature regenerator 84. As will be described later in detail, the combustion exhaust gas from the high-temperature regenerator 10 is introduced into the exhaust gas heat exchanger 120 to heat the absorption liquid and recover the heat retained in the exhaust gas.
[0043]
In the absorption chiller / heater configured as described above, the following configuration is further added. That is, the cold / hot water outlet pipe is provided with the cold / hot water temperature sensor 102, the steam drain pipe from the intermediate temperature regenerator 87 is provided with the steam drain temperature sensor 104, and the cold / hot water outlet pipe 30 from the gas-liquid separator 26 absorbs the absorbed liquid. A liquid temperature sensor 112 is provided, and a steam temperature sensor 116 and a pressure gauge (pressure sensor) 118 are provided in a steam extraction pipe (steam supply pipe) 28. The steam drain temperature sensor, the steam temperature sensor, and the steam pressure sensor need not be provided at the same time, but one of them may be selected and provided. Also, two or more may be provided. Further, as described above, an absorbent temperature sensor 46 for preventing empty cans is provided on the lower surface of the lower header 14 of the once-through boiler 10.
[0044]
An operation panel 114 for operation control / safety control is provided. The operation panel 114 includes a cold / hot water temperature sensor 102, a steam drain temperature sensor 104, a liquid level detection / control device 44 of a gas-liquid separator, a combustion device 18, Absorbent temperature sensor 112, Absorbent temperature sensor 46 for preventing empty cans, diluted liquid pump (low-temperature absorbent pump) 82, intermediate liquid pump (high-temperature absorbent pump) 85, water / absorbent liquid supply pump 93, steam extraction A steam temperature sensor 116, a pressure gauge (pressure sensor) 118, and an exhaust gas temperature sensor 124 of a conduit (steam supply pipe) 28 are connected in conjunction with each other, so that the temperature, pressure, flow rate, and the like of these components can be controlled. . Note that the steam drain temperature sensor, the steam temperature sensor, and the steam pressure sensor are not provided at the same time, but one of them is selected and provided. Also, two or more may be provided.
[0045]
Further, an evaporator absorption liquid supply pipe 158 for introducing the absorption liquid into the evaporator 89 is connected to the heating-side absorption liquid pipe 156 between the high-temperature heat exchanger 86 and the low-temperature heat exchanger 83, and The second valve 152 is connected to the absorption liquid supply pipe 158, the third valve 153 is connected to the return absorption liquid pipe 160 to the absorber 81, and the exhaust gas heat exchanger is used to send a part of the absorption liquid to the exhaust gas heat exchanger 120. A fourth valve 154 is provided in the liquid supply pipe 162, and a bypass pipe 164 is connected to the fourth valve 154 to constitute a triple effect absorption chiller / heater. In this triple effect absorption chiller / heater, at least the second valve 152, the third valve 153, and the fourth valve 154 are controlled so that the exhaust gas temperature detected by the exhaust gas temperature sensor 124 does not become lower than the drain generation temperature, for example, 100 ° C or lower. Either of them is controlled individually or simultaneously, and the start and stop of the refrigerant pump 90 of the evaporator is controlled to prevent the generation of condensed water in the exhaust gas heat exchanger 120.
[0046]
The second valve 152, the third valve 153, and the fourth valve 154 for controlling the newly added absorption liquid amount may be an ON-OFF valve or a proportional control valve. Control by an effective combination is performed by these valves and the bypass valve so that the exhaust gas temperature does not drop too much.
Although the drain generation temperature is set to 100 ° C. as an example, the set value may be changed to 90 ° C. depending on the operating conditions.
[0047]
The operation of the absorption chiller / heater configured as above will be described. A temperature change on the load side is detected by a cold / hot water temperature sensor 102 provided on a cold / hot water outlet pipe from the evaporator 89, and the temperature change is detected by a control signal from an operation control / safety control operation panel 114 by the combustion device 18 or fuel. The fuel supplied to the high-temperature regenerator 10 is increased or decreased by introducing the fuel into the flow rate control valve (not shown), and the combustion amount of the combustion device 18 is increased or decreased, so that the high-temperature regenerator 10 is efficiently operated.
At the same time, the absorbent pumps 82, 85, and 93 are operated to stably supply and circulate the absorbents having different water content ratios to perform continuous operation. That is, a part of the absorbent flowing into the absorbent pump 85 for supplying the liquid from the low-temperature regenerator 84 to the intermediate-temperature regenerator 87 is branched and bypassed to the return pipe by the bypass pipe 95, and at the same time, A part of the liquid flowing into the absorption liquid supply pump 93 is branched and bypassed by the bypass pipe 96, the supply and circulation amount of water / absorption liquid is adjusted, and the power load applied to the pumps 85 and 93 is adjusted. Performs energy saving and stable continuous operation.
[0048]
Further, the temperature of the load (cold / hot water) is detected by the cold / hot water temperature sensor 102, and the amount of combustion (heating amount) of the combustion device 18 is increased / decreased via the operation panel 114, and at the same time, the steam pressure inside the high temperature regenerator 10 rises. If the temperature rises and the temperature detected by the steam drain temperature sensor 104 at the outlet of the high-temperature regenerator of the absorption refrigerator heated by steam rises, the absorption liquid is supplied via the operation panel 114 for safety. If the rotation speed of the supply pump 93 is increased to increase the amount of liquid circulation and as a result the steam pressure is reduced and the drain temperature detected by the steam drain temperature sensor 104 is reduced, the absorption liquid supply pump 93 The number of circulating fluids is reduced by lowering the number of revolutions to increase the vapor pressure so that stable operation can be continued in a temperature range and pressure range suitable for continuous operation. Controlling the rotation speed of the pump 82 simultaneously with the pump 93 has the effect of further increasing the corresponding speed. Even if the pump 85 is operated at a constant speed without changing the rotation speed, the flow rate is adjusted by the bypass pipe 95, so that there is no problem even if the rotation speed is not controlled.
[0049]
Or, at the same time as the amount of combustion (heating amount) of the combustion device 18 is increased or decreased by the temperature change of the load (cold / hot water), the vapor pressure inside the high-temperature regenerator 10 is increased and the temperature is increased, and the high-temperature regenerator outlet is increased. If the steam pressure detected by the steam pipe or the temperature detected by the temperature sensor 116 rises, the rotation speed of the absorbing liquid pump 93 is increased for safety, and the liquid circulation amount is increased. If the pressure is reduced and the steam pressure or temperature is reduced, the number of revolutions of the absorption liquid supply pump 93 is reduced to reduce the amount of circulating liquid to increase the vapor pressure, and stable operation in a temperature range and pressure range suitable for continuous operation is achieved. Be able to continue. Raising and lowering the rotation speed of the pump 82 at the same time as raising and lowering the rotation speed of the pump 93 has the effect of increasing the response speed and improving controllability.
[0050]
The liquid level during operation of the high-temperature regenerator 10 is detected by the liquid level detection / control device 44, and when the liquid level of the gas-liquid separator 26 rises, the rotation speed of the water / absorbent liquid supply pump 93 is increased. To reduce the liquid level and lower the liquid level. On the other hand, when the liquid level drops, control is performed so that the rotation speed of the pump 93 is increased to increase the liquid circulation amount and raise the liquid level. Further, when the operating liquid level of the high temperature regenerator 10 is lower than the lower limit set value of the safe operation, an alarm is issued via the operation panel 114 to shut off the combustion and start the safe stop operation.
[0051]
In this case, as a method of detecting the liquid level during operation of the high-temperature regenerator 10 by the liquid level detection / control device 44 and controlling the number of rotations of the pump 93, a predetermined rotation is performed by receiving operating conditions and a control signal. A method using a step control formula that changes the number stepwise, a method using a continuous control formula that continuously changes the rotation speed in response to the operating conditions, load signal, and control signal are adopted. You.
[0052]
The steam drain temperature, steam temperature, steam pressure or the operating liquid level of the boiler during operation is detected by the steam drain temperature sensor 104, the steam temperature sensor 116, the steam pressure gauge 118 or the liquid level detecting device 44, and the rotation speed of the pump is determined. Is controlled, the low-temperature absorbing liquid pump 82, the high-temperature absorbing liquid pump 85, and the water / absorbing liquid supply pump 93 are simultaneously or independently used, or the low-temperature absorbing liquid pump 82 and the water / absorbing liquid are controlled separately. From an operation method selected from a combination of only two supply pumps 93 or the like, it is possible to switch to one method or a plurality of methods, and the number of rotations is controlled to supply the amount of water-containing absorbent (circulation amount). And the pumps are controlled so as to increase the operation efficiency and to secure the rotation speed at which each pump does not cause a shortage of the supply amount (circulation amount) or a shortage of the head (head).
[0053]
Further, during operation, when a supply device for supplying water / absorbent to the high-temperature regenerator 10, for example, the water / absorbent supply pump 93 fails and the supply amount decreases, the high-temperature regenerator 10 is internally provided. Since the amount of water / absorbed liquid held is reduced and continuous operation is hindered, a warning is issued and at the same time, combustion is cut off and control is performed so as to start a safe stop operation.
[0054]
Also, during operation, when the supply amount of water / absorbent to the high-temperature regenerator 10 decreases, or when the amount of water / absorbent retained in the high-temperature regenerator 10 decreases, the temperature of each part becomes the set value for safe operation. Is exceeded, an alarm is issued via the operation panel 114 by the high temperature regenerator 10 or the absorbent temperature sensor 112 provided at the absorbent outlet of the high temperature regenerator 10 or the absorbent temperature sensor 46 for preventing empty cans. At the same time, control is performed so as to shut off combustion and enter a safe stop operation.
[0055]
When the temperature detected by the exhaust gas temperature sensor 124 exceeds the drain generation temperature, the second valve 152 is fully opened, the third valve 153 is fully closed, the fourth valve 154 is fully opened, and the refrigerant pump 90 is operated and absorbed. By operating the liquid pumps 82, 85, and 93, the absorbing liquid heated to a high temperature is sprayed on the evaporator tube (for example, heat exchange is performed directly with hot water). Therefore, the operation becomes extremely efficient, and the temperature of the hot water taken out can be raised to about 80 ° C.
[0056]
Further, when the temperature detected by the exhaust gas temperature sensor 124 exceeds the drain generation temperature, the second valve 152 is automatically controlled between the fully closed state and the fully opened state, and is activated when the second valve 152 approaches the fully closed state. The refrigerant pump 90 is stopped, the third valve 153 is not used or not provided in advance, the fourth valve 154 is fully opened, and the absorbent pump is operated to spray the absorbent heated to a high temperature to the evaporator tube. In some cases.
[0057]
When the temperature detected by the exhaust gas temperature sensor 124 is equal to or lower than the drain generation temperature, the second valve 152 is fully closed, the third valve 153 is fully opened, the fourth valve 154 is fully opened, and the refrigerant pump 90 is stopped and absorbed. By operating the liquid pump, only the refrigerant vapor and the refrigerant vapor drain flowing from the cooling / heating switching valve (first valve) 151 are sprayed to the evaporator tube to exchange heat with the hot water flowing in the heat transfer tube. Therefore, the temperature of the hot water cannot be increased very much. In this case, it is necessary to raise the temperature of the absorbing liquid circulating in the absorption chiller / heater, so that the efficiency is slightly lowered. However, there is a sufficient effect for the purpose of protecting the heat transfer tube in the exhaust gas heat exchanger 120 from corrosion of condensed water.
[0058]
In these methods, the fourth valve 154 may not be used or may not be provided in advance.
In addition, the opening degree of the fourth valve 154 can be adjusted to control the amount of the absorbent circulating to the exhaust gas heat exchanger 120 so that the temperature detected by the exhaust gas temperature sensor 124 does not become lower than the drain generation temperature.
In this method, a part of the liquid flowing through the fourth valve 154 is bypassed so that the flow of the absorbing liquid circulating to the exhaust gas heat exchanger 120 does not stop. Reference numeral 164 denotes a bypass pipe, which is provided with an orifice so as not to form a bypass.
[0059]
In these methods, a part of the liquid flowing through the second valve 152 may be bypassed so that the flow of the absorbent circulating to the evaporator 89 does not stop. Also in this case, the bypass pipe is provided with an orifice so as not to bypass the entire amount.
In these methods, the amount of combustion of the absorption chiller / heater may be controlled to increase or decrease when the temperature detected by the chiller / heater temperature sensor 102 deviates from a preset temperature. The amount of combustion is not controlled by the degree of opening of the cooling / heating switching valve (first valve) 151, the second valve 152, the third valve 153, and the fourth valve 154.
In these methods, it is preferable that the liquid level of the high-temperature regenerator 10 is controlled by the liquid-level detection / control device 44 provided in the high-temperature regenerator 10 to prevent the liquid level from lowering.
[0060]
FIG. 2 shows an absorption chiller / heater for implementing a control method according to a second embodiment of the present invention. In this embodiment, instead of detecting and controlling the exhaust gas temperature with an exhaust gas temperature sensor, an absorbent temperature sensor 166 is provided at the heat transfer tube of the exhaust gas heat exchanger 120 or at the outlet of the heat transfer tube. It is configured to detect and control the temperature of the absorbent flowing in the exhaust gas heat exchanger 120. The temperature of the absorbing solution is controlled, for example, at 80 ° C. Other configurations and operations are the same as those of the first embodiment.
[0061]
【The invention's effect】
The present invention is configured as described above, and has the following effects.
(1) During the heating operation, the absorbing liquid is mixed with the refrigerant, and the mixed liquid is sprayed on the heat transfer tubes of the evaporator to exchange heat with the warm water passing through the heat transfer tubes, thereby lowering the temperature of the absorbing solution, thereby absorbing the liquid. The temperature of the exhaust gas that exchanges heat with the liquid also decreases. Therefore, the amount of heat recovered during the heating operation increases, and the heating efficiency is improved.
(2) High-temperature regenerator, medium-temperature regenerator, low-temperature regenerator, condenser, absorber, evaporator, heat exchangers, solution pump, refrigerant pump, cooling / heating switching with once-through boiler or structure similar to once-through boiler In a triple effect absorption chiller / heater having a valve and an exhaust gas heat exchanger, the flow rate of the absorption liquid is controlled so as not to adversely affect the temperature of the hot water supplied to the load side during the heating operation and to reduce the efficiency without lowering the efficiency. Since the control valve is provided and controlled, it is possible to prevent the exhaust gas temperature from lowering and prevent the generation of drainage, thereby preventing corrosion of the heat transfer tube.
(3) At the same time as increasing or decreasing the combustion amount (heating amount) of the combustion device by the temperature change of the load (hot water), at the same time, depending on the exhaust gas temperature at the outlet of the exhaust gas heat exchanger or the absorption liquid temperature of the heat transfer tube of the exhaust gas heat exchanger, A control function to control the amount of circulating absorbent rather than the amount of combustion is provided, and the amount of combustion is controlled by the control signal from the cold / hot water temperature sensor due to load fluctuations. The temperature of the exhaust gas passing through the exhaust gas heat exchanger rises, and there is no danger of condensation drain generation.However, if the amount of combustion decreases and the temperature of the circulating absorbent decreases, the temperature of the exhaust gas passing through the exhaust gas heat exchanger also decreases. Condensed drain is generated and adversely affects the heat transfer tube. At this time, if the combustion amount is controlled, the temperature of the hot water supplied to the load side is adversely affected and, at the same time, the efficiency is reduced. Therefore, a control valve is provided in a pipe in which the absorbent circulates to control or circulate the absorbent circulating amount. By switching the path to be performed, it is possible to prevent the generation of drain and the corrosion of the heat transfer tube.
[Brief description of the drawings]
FIG. 1 is a systematic schematic configuration diagram of an absorption chiller / heater implementing a control method according to a first embodiment of the present invention.
FIG. 2 is a systematic schematic configuration diagram of an absorption chiller / heater implementing a control method according to a second embodiment of the present invention.
FIG. 3 is a systematic schematic configuration diagram of an absorption chiller / heater developed by the present applicant.
FIG. 4 is a systematic schematic configuration diagram showing an example of a conventional absorption refrigerator.
[Explanation of symbols]
10 High temperature regenerator
12 Upper header
14 Lower header
16 riser
18 Combustion device
20 Combustion chamber
24 Gas-liquid mixture conduit
26 Gas-liquid separator
28 Steam extraction pipe (steam supply pipe)
30 Absorbent extraction pipe
36 Absorbent circulation circuit
42 Absorbent supply pipe (water / absorbent supply pipe)
44 Liquid level detection and control device
46 Absorbent temperature sensor to prevent empty cans
81 absorber
82 Rare liquid pump (low temperature absorption liquid pump)
83 low temperature heat exchanger
84 Low temperature regenerator
85 Intermediate liquid pump (high temperature absorbing liquid pump)
86 High temperature heat exchanger
87 Medium temperature regenerator
88 condenser
89 evaporator
90 refrigerant pump
93 Absorbent pump (water / absorbent supply pump)
94 additional heat exchanger
95, 96 Bypass pipe
97, 98 Refrigerant vapor piping
99 Cold and hot water pump
100 cooling water pump
102 Cold and hot water temperature sensor
104 Steam drain temperature sensor
112 Absorbent temperature sensor
114 Operation panel for operation control and safety control
116 Steam temperature sensor
118 Pressure gauge (pressure sensor)
120 Exhaust gas heat exchanger
122 Exhaust gas passage
124 Exhaust gas temperature sensor
151 Cooling / heating switching valve (first valve)
152 second valve
153 3rd valve
154 4th valve
156 Absorption liquid piping on heating side
158 Absorbent supply pipe for evaporator
160 Return absorption liquid pipe
162 Absorption liquid supply pipe for exhaust gas heat exchanger
164 bypass pipe
166 Absorbent temperature sensor

Claims

A once-through boiler or a boiler having the same structure as a once-through boiler, as a high-temperature regenerator. It has a condenser, an absorber, an evaporator, a heat exchanger, a solution pump, a refrigerant pump, a cooling / heating switching valve, and an exhaust gas heat exchanger. The absorption liquid in the absorber is transferred from a low-temperature regenerator to a medium-temperature regenerator, and then to a high temperature. A reverse-flow triple-effect absorption chiller / heater that leads to a regenerator, detects a temperature change on the load side from a chilled / hot water temperature sensor, and detects the temperature change based on a control signal from an operation panel for operation control and safety control. The amount of fuel supplied to the boiler is increased and decreased, and the amount of combustion in the combustion device is increased or decreased to operate the boiler efficiently. Stable supply and continuous A pipe for circulating and flowing the liquid that can be rotated, and a pipe for branching a part of the absorbent flowing into the absorbent pump for supplying the liquid from the low-temperature regenerator to the higher-level regenerator and bypassing the return pipe. At the same time, it has a pipe that branches off a part of the liquid flowing into the water / absorbent liquid supply pump from the intermediate temperature regenerator and bypasses it to the return pipe. By adjusting the applied power load, energy saving and stable continuous operation can be performed.An exhaust gas heat exchanger is provided in the exhaust gas passage of the high temperature regenerator. A part of the liquid from the absorption liquid pump for supplying is introduced through the absorption liquid supply pipe for the exhaust gas heat exchanger and heated by the exhaust gas, and an exhaust gas temperature sensor is provided in an exhaust gas passage at the outlet of the exhaust gas heat exchanger. This exhaust gas temperature sensor and the The operation panel for control and safety control is interlocked, and the absorption liquid for the evaporator for introducing the absorption liquid to the evaporator is connected to the absorption liquid pipe on the heating side between the high-temperature heat exchanger and the low-temperature heat exchanger. A supply pipe is connected, a second valve is provided in the evaporator absorption liquid supply pipe, a third valve is provided in the return absorption liquid pipe to the absorber, and a fourth valve is provided in the exhaust gas heat exchanger absorption liquid supply pipe, In the triple effect absorption chiller / heater in which a bypass pipe is connected to the fourth valve, at least one of the second, third, and fourth valves is controlled so that the exhaust gas temperature detected by the exhaust gas temperature sensor does not become lower than the drain generation temperature. Heating of a triple effect absorption chiller / heater characterized by controlling any one of them independently or simultaneously, and controlling the start / stop of a refrigerant pump of an evaporator to prevent generation of condensed water in an exhaust gas heat exchanger. Operation control method.

When the temperature detected by the exhaust gas temperature sensor exceeds the drain generation temperature, the second valve is fully opened, the third valve is fully closed, the fourth valve is fully opened, and the refrigerant pump and the absorbent pump are operated. The method for controlling heating operation of a triple effect absorption chiller / heater according to claim 1, wherein the absorption liquid heated to a high temperature is sprayed on the evaporator tube .

When the temperature detected by the exhaust gas temperature sensor is equal to or lower than the drain generation temperature, the second valve is fully closed, the third valve is fully opened, the fourth valve is fully opened, and the refrigerant pump is stopped and the absorbent pump is operated. The heating operation control method for a triple effect absorption chiller / heater according to claim 1, wherein only the refrigerant vapor and the refrigerant vapor drain flowing from the cooling / heating switching valve are sprayed to the evaporator tube to exchange heat with the hot water flowing in the heat transfer tube. .

The heating operation control method for a triple effect absorption chiller / heater according to claim 2 or 3 , wherein the fourth valve is not used or is not provided in advance.

The triple effect according to claim 2 or 3, wherein the amount of the absorbent circulated to the exhaust gas heat exchanger is controlled by adjusting the opening of the fourth valve so that the temperature detected by the exhaust gas temperature sensor does not become lower than the drain generation temperature. Heating operation control method for absorption chiller / heater.

Instead of detecting and controlling the exhaust gas temperature with an exhaust gas temperature sensor, an exhaust gas heat exchanger heat transfer pipe or an absorbent temperature sensor is provided at the outlet of the heat transfer pipe, and the absorbent flowing through the exhaust gas heat exchanger with the absorbent temperature sensor is used. The heating operation control method for a triple effect absorption chiller / heater according to any one of claims 1 to 5 , wherein the temperature is detected and controlled.

6. The heating operation control method for a triple effect absorption chiller / heater according to claim 5, wherein a part of the liquid flowing through the fourth valve is bypassed so that the flow of the absorbing liquid circulating to the exhaust gas heat exchanger does not stop .

The heating of a triple effect absorption chiller / heater according to any one of claims 1 to 7 , wherein the amount of combustion of the absorption chiller / heater is increased or decreased when the temperature detected by the chiller / heater temperature sensor deviates from a preset temperature. Operation control method.

The heating operation control of the triple effect absorption chiller / heater according to any one of claims 1 to 8 , wherein a liquid level detection / control device is provided in the high temperature regenerator to control the liquid level of the high temperature regenerator to prevent the liquid level from lowering. Method.