JP2004190886A

JP2004190886A - Absorption refrigerating machine and absorption refrigerating system

Info

Publication number: JP2004190886A
Application number: JP2002356475A
Authority: JP
Inventors: Yukihiro Fukuzumi; 幸大福住; Osayuki Inoue; 修行井上; Kiichi Irie; 毅一入江
Original assignee: Ebara Corp
Current assignee: Ebara Corp
Priority date: 2002-12-09
Filing date: 2002-12-09
Publication date: 2004-07-08

Abstract

<P>PROBLEM TO BE SOLVED: To provide an absorption refrigerating machine and an absorption refrigerating system equipped therewith capable of efficiently manufacturing cold heat by effectively using the exhaust heat when the temperature difference between an inlet port and an outlet port of a heating medium is large. <P>SOLUTION: The absorption refrigerating machine is equipped with a first generator G1 which heats and condenses absorption liquid with the heating medium 31w, a first condenser C1 which cools and condenses refrigerant vapor generated in the first generator G1 with a first cooling medium 16w, a second generator G2 which heats and condenses the absorption liquid condensed in the first generator G1 with the heating medium 31w, and a second condenser C2 which cools and condenses the refrigerant vapor generated in the second generator G2 with the first cooling medium 16w. The absorption refrigerating machine supplies the heating medium 31w to the second generator G2 and the first generator G1 in series in this order, and supplies the first cooling medium 16w to the first condenser C1 and the second condenser C2 in series in this order. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、吸収冷凍機及び吸収冷凍機を備える冷凍システムに関し、特に温度差の大きい排熱を有効に使って、効率良く冷熱を製造できる吸収冷凍機及びそのような冷凍機を備える冷凍システムに関するものである。
【０００２】
【従来の技術】
従来から、コージェネレーションシステムで発電に伴って出される排ガスや排温水によって運転する吸収冷凍機があった。ガスエンジンやガスタービンから出される排ガスは、その温度が２００〜３００℃と比較的高温であるため、この排ガスで１５０℃程度の蒸気を発生させたり、あるいは排ガスを直接投入するなどして、２重効用の吸収冷凍機を運転することが一般に知られている。また、ガスエンジン／ガソリンエンジン／ディーゼルエンジン等のジャケット温水や、太陽熱集熱器で得られる温水は、その温度が８０〜９０℃であり、単効用の吸収冷凍機や、ジェネリンク、二重効用吸収冷凍機などの熱源として利用する装置が一般に知られている（例えば、特許文献１参照）。
【０００３】
【特許文献１】
特開平０８−５４１５６号公報（図１、図２）
【０００４】
【発明が解決しようとする課題】
しかしながら、以上のような従来の装置では、出入り口の温度差が大きい排熱を利用することが困難であり、一方エンジンや燃料電池からの排温水は、それ自身がエンジンや燃料電池の冷却水であるため、低い温度まで冷却して戻す必要がある。また排温水の搬送動力を低減するためにも、循環する熱媒（加熱用流体）の出入り口温度差を大きくしたいという要請があるが、従来の装置ではこれに対応しきれていなかった。
【０００５】
そこで本発明は、加熱媒体の出入り口温度差が大きい場合に、その排熱を有効に使って、効率良く冷熱を製造できる吸収冷凍機及びそのような吸収冷凍機を備える吸収冷凍システムを提供することを目的としている。
【０００６】
【課題を解決するための手段】
上記目的を達成するために、請求項１に係る発明による吸収冷凍機は、例えば図１に示されるように、吸収液を加熱媒体３１ｗで加熱して濃縮する第１の発生器Ｇ１と；第１の発生器Ｇ１で発生した冷媒蒸気を第１の冷却媒体１６ｗで冷却し凝縮する第１の凝縮器Ｃ１と；第１の発生器Ｇ１で濃縮された吸収液を加熱媒体３１ｗで加熱してさらに濃縮する第２の発生器Ｇ２と；第２の発生器Ｇ２で発生した冷媒蒸気を第１の冷却媒体１６ｗで冷却し凝縮する第２の凝縮器Ｃ２とを備え；加熱媒体３１ｗを、第２の発生器Ｇ２と第１の発生器Ｇ１に、この順に直列に流し、第１の冷却媒体１６ｗを、第１の凝縮器Ｃ１と第２の凝縮器Ｃ２に、この順に直列に流すように構成される。
【０００７】
典型的には、第１の凝縮器Ｃ１で凝縮された冷媒と第２の凝縮器Ｃ２で凝縮された冷媒とを受け入れて、該冷媒を蒸発させて冷熱媒体４１ｗを冷却する蒸発器Ｅと、第２の発生器Ｇ２で濃縮された吸収液を受け入れて、蒸発器Ｅで蒸発した冷媒を吸収する吸収器Ａとを備える。また吸収器Ａから第１の発生器Ｇ１に送られる吸収液と第２の発生器Ｇ２から吸収器Ａに戻る吸収液との間で熱交換させる熱交換器１０を備える。発生器と凝縮器は、第１と第２に限らず、第３以上を備えてもよい。
【０００８】
このように構成すると、加熱媒体を、第２の発生器と第１の発生器に、この順に直列に流し、第１の冷却媒体を、第１の凝縮器と第２の凝縮器に、この順に直列に流すように構成するので、加熱媒体の出入り口温度差が大きい場合に、その排熱を有効に使うことができる。
【０００９】
また請求項２に記載のように、また例えば図３に示すように、請求項１に記載の吸収冷凍機では、第１の凝縮器Ｃ１で凝縮された冷媒と第２の凝縮器Ｃ２で凝縮された冷媒とを受け入れて、該冷媒を蒸発させて冷熱媒体４１ｗを冷却する第１の蒸発器Ｅ１と；第１の凝縮器Ｃ１で凝縮された冷媒と第２の凝縮器Ｃ２で凝縮された冷媒とを受け入れて、該冷媒を蒸発させて冷熱媒体を冷却する第２の蒸発器Ｅ２と；第２の発生器Ｇ２で濃縮された吸収液を受け入れて、該吸収液を第２の冷却媒体１５ｗで冷却しながら該吸収液で第１の蒸発器Ｅ１で蒸発した冷媒を吸収する第１の吸収器Ａ１と；第１の吸収器Ａ１で冷媒を吸収した吸収液を受け入れて、該吸収液を第２の冷却媒体１５ｗで冷却しながら該吸収液で第２の蒸発器Ｅ２で蒸発した冷媒を吸収する第２の吸収器Ａ２とを備え；冷熱媒体４１ｗを、第２の蒸発器Ｅ２と第１の蒸発器Ｅ１に、この順に直列に流すように構成してもよい。
【００１０】
典型的には、第２の冷却媒体１５ｗを、第１の吸収器Ａ１と第２の吸収器Ａ２に、この順に直列に流す。また典型的には、第２の吸収器Ａ２から第１の発生器Ｇ１に送られる吸収液と第２の発生器Ｇ２から第１の吸収器Ａ１に戻る吸収液との間で熱交換させる熱交換器１０を備える。ここで、吸収器と蒸発器は、第１と第２に限らず、第３以上を備えてもよい。
また第１の冷却媒体と第２の冷却媒体は、同じ系統から供給してもよい。典型的には、例えば同じ冷却塔から供給される冷却水とする。
【００１１】
上記目的を達成するために、請求項３に係る発明による吸収冷凍システムは、例えば図１、図２に示すように、請求項１又は請求項２に記載の吸収冷凍機１０１ａ、１０２ａと；加熱媒体３１ｗを供給する加熱源３とを備える。
【００１２】
また請求項４に記載のように、請求項３に記載の吸収冷凍システムでは、前記加熱源は、燃料電池としてもよい。
【発明の実施の形態】
以下、本発明の実施の形態について、図面を参照して説明する。なお、各図において互いに同一あるいは相当する部材には同一符号あるいは類似符号を付し、重複した説明は省略する。
【００１３】
図１のフロー図を参照して、本発明の第１の実施の形態である吸収冷凍機とそれを備える吸収冷凍システムを説明する。本吸収冷凍機１０１ａと加熱源としての外部熱源装置、具体的には燃料電池３とを含んで、本発明の実施の形態である吸収冷凍システム１０１が構成される。吸収冷凍機１０１ａの作業媒体としては、吸収剤と冷媒の組合せが用いられる。本実施の形態では、各種吸収冷凍機で現在最も広く用いられている、臭化リチウムを吸収剤として使用し、本発明の冷媒として水を使用する。しかしながらこれに限らず、例えば水を吸収剤として、アンモニアを冷媒として使用してもよい。
【００１４】
本実施の形態で使用する吸収冷凍機１０１ａは、単効用吸収冷凍機に準ずる吸収冷凍機である。再生器を複数備えるものの、第１の再生器で蒸発した冷媒蒸気を第２再生器の加熱媒体として用いる二重効用吸収冷凍機とは区別される。吸収冷凍機１０１ａは、冷媒としての水を蒸発させて、冷熱源媒体としての冷水４１ｗを冷却する蒸発器Ｅを備える。蒸発器Ｅは伝熱部を有するが、本実施の形態では、伝熱部として冷水伝熱管４１ａを採用している。蒸発器Ｅでは、冷水伝熱管４１ａの内部を流れる冷水４１ｗを冷却する。蒸発器Ｅには、冷水４１ｗを供給する冷水配管４１が接続されている。
【００１５】
さらに吸収冷凍機１０１ａは、蒸発器Ｅで蒸発した冷媒を吸収する吸収器Ａと、吸収器Ａから送られる吸収液（吸収剤と冷媒の混合物、以下適宜「溶液」とも呼ぶ）を加熱して冷媒ガスを発生させる第１の再生器Ｇ１と、第１の再生器Ｇ１である程度まで濃縮された吸収液を受け入れて、加熱して冷媒ガスを発生させる第２の再生器Ｇ２を備える。さらに吸収冷凍機１０１ａは、第１の再生器Ｇ１で発生した冷媒ガスを凝縮して、凝縮した冷媒液を蒸発器Ｅに送る第１の凝縮器Ｃ１と、第２の再生器Ｇ２で発生した冷媒ガスを凝縮して、凝縮した冷媒液を蒸発器Ｅに送る第２の凝縮器Ｃ２とを備える。
【００１６】
第１の再生器Ｇ１と第１の凝縮器Ｃ１とは第１の缶胴に収納され、第２の再生器Ｇ２と第２の凝縮器Ｃ２とは、第１の缶胴とは別の第２の缶胴に収納されている。第１の缶胴と第２の缶胴とは、別体に構成されるか、仕切壁により隔離されている。したがって、両缶胴内の圧力は互いに異ならせることができる。
【００１７】
吸収器Ａは伝熱部として冷却水伝熱管１５ａを有し、この内部を流れる第２の冷却媒体としての冷却流体、具体的には冷却水１５ｗで、冷却水伝熱管１５ａの外部に散布される溶液を冷却する。
再生器Ｇ１、Ｇ２は伝熱部としてそれぞれ温水伝熱管３１ａ、３１ｂを有し、この内部を流れる外部熱源媒体としての加熱用流体、具体的には温水で、それぞれ温水伝熱管３１ａ、３１ｂの外部に溜まっている、又は温水伝熱管３１ａ、３１ｂ上に散布されている溶液を加熱する。
凝縮器Ｃ１、Ｃ２は伝熱部としてそれぞれ冷却水伝熱管１６ａ、１６ｂを有し、この内部を流れる第１の冷却媒体としての冷却流体、具体的には冷却水１６ｗで、冷却水伝熱管１６ａ、１６ｂの外部に存在する冷媒ガスから熱を奪い凝縮させる。
以下、冷水伝熱管４１ａ、冷却水伝熱管１５ａ、１６ａ、１６ｂ、温水伝熱管３１ａ、３１ｂは、紛らわしくない限り、適宜単に伝熱管４１ａ、伝熱管１５ａ、１６ａ、１６ｂ、伝熱管３１ａ、３１ｂという。
【００１８】
吸収器Ａには、冷却水１５ｗを供給する冷却水配管１５が接続されており、第１、第２の再生器Ｇ１、Ｇ２には、温水３１ｗを供給する温水配管３１が接続されており、第１、第２の凝縮機Ｃ１、Ｃ２には、冷却水１６ｗを供給する冷却水配管１６が、それぞれ接続されている。
また、第１の再生器Ｇ１と第２の再生器Ｇ２とは、第１の再生器Ｇ１である程度再生された吸収液である中間濃度の吸収液を第２の再生器Ｇ２に戻す中間濃度溶液配管１３ａで接続され、第２の再生器Ｇ２と吸収器Ａは、第２の再生器Ｇ２で再生された溶液を吸収器Ａに戻す濃溶液配管１３ｂで接続されている。また吸収器Ａと第１の再生器Ｇ１とは、吸収器Ａで冷媒を吸収して希溶液となった溶液を第１の再生器Ｇ１に送る希溶液配管１４で接続されている。濃溶液配管１３ｂと希溶液配管１４には、溶液熱交換器１０が挿入配置されており、第２の再生器Ｇ２から吸収器Ａに戻される濃溶液と吸収器Ａから第１の再生器Ｇ１に送られる希溶液との間で熱交換を行うように構成されている。
【００１９】
また第１の再生器Ｇ１は第２の再生器Ｇ２よりも高所に、第２の再生器Ｇ２は吸収器Ａよりも高所に配置されており、また両再生器Ｇ１、Ｇ２の作動圧力は吸収器Ａのそれよりも高い。したがって、希溶液配管１４には溶液ポンプ１１が挿入配置されており、希溶液配管１４を通して吸収器Ａから第１の再生器Ｇ１に溶液を送ることを可能としている。中間濃度溶液配管１３ａ、濃溶液配管１３を通して行われる、第１、第２の再生器Ｇ１、Ｇ２から吸収器Ａへの中間濃度溶液と濃溶液の移送は重力及び各機器間の圧力差により行われる。
【００２０】
吸収冷凍機１０１ａは、さらに第１の凝縮器Ｃ１で凝縮した冷媒液を蒸発器Ｅに戻す冷媒配管１２ａと、第２の凝縮器Ｃ２で凝縮した冷媒液を蒸発器Ｅに戻す冷媒配管１２ｂとを備える。本図では、冷媒配管１２ａ、１２ｂは冷媒配管１２に合流した上で蒸発器Ｅに戻す場合が示されているが、冷媒配管１２ａ、１２ｂを別々に蒸発器Ｅに接続して、冷媒液を別々に戻してもよい。
【００２１】
吸収冷凍機１０１ａの外部には、冷水負荷としての室内空調機４があり、室内空調機４と蒸発器Ｅとは、冷水配管４１で接続されている。このような構成により、冷水配管４１を流れる冷水４１ｗは、室内空調機４と吸収圧縮冷凍装置１０１との間を循環するように構成されている。
【００２２】
吸収冷凍機１０１ａの外部には、外部熱源装置としての燃料電池３があり、燃料電池３と第２の再生器Ｇ２、第１の再生器Ｇ１とは、温水配管３１で接続されている。第１の再生器Ｇ２の伝熱管３１ｂと第１の再生器Ｇ１の伝熱管３１ａとは、温水配管３１により、温水の流れの上流側からこの順番で直列に連結されている。したがって、温水配管３１を流れる温水３１ｗは、燃料電池３、第２の再生器Ｇ２の温水伝熱管３１ｂ、第１の再生器Ｇ１の温水伝熱管３１ａの順番で流れ、燃料電池３に戻る。このようにして、温水３１ｗは燃料電池３と吸収冷凍機１０１ａの間を循環するように構成されている。
【００２３】
引き続き図１を参照して、第１の実施の形態中の吸収冷凍機１０１ａのサイクル（２段再生サイクル）について説明する。蒸発器Ｅで冷水伝熱管４１ａを流れる冷水４１ｗから熱を奪い蒸発した冷媒蒸気は、吸収器Ａにて冷却水伝熱管１５ａを流れる冷却水１５ｗで冷却されている溶液に吸収される。吸収器Ａ中の溶液は、不図示のポンプにより冷水伝熱管１５ａ上に散布される。散布された溶液は吸収器Ａの底部に溜まり、再び前記ポンプにより吸い込まれ散布される。
【００２４】
冷媒を吸収して吸収剤の濃度が低下した希溶液は、溶液ポンプ１１によって溶液熱交換器１０に送られ、そこで第２の再生器Ｇ２から戻る高温の濃溶液と熱交換し、昇温して第１の再生器Ｇ１に入る。第１再生器Ｇ１では温水伝熱管３１ａを流れる温水３１ｗによって溶液が加熱され、冷媒蒸気を放出して濃縮され、中濃度の溶液になる。この中濃度の溶液は第２の再生器Ｇ２に入り、温水伝熱管３１ｂを流れる温水３１ｗによって加熱され、冷媒蒸気を放出して濃縮されて濃溶液となる。この濃溶液は溶液熱交換器１０にて熱回収され温度が低下して吸収器Ａに戻る。一方、第１の発生器Ｇ１で発生した冷媒蒸気は、第１の凝縮器Ｃ１で冷却水伝熱管１６ａを流れる冷却水１６ｗにより冷却され凝縮する。同様に、第２の発生器Ｇ２で発生した冷媒蒸気は、第２の凝縮器Ｃ２で冷却水伝熱管１６ｂを流れる冷却水１６により冷却され凝縮する。これら凝縮した冷媒液は合流して蒸発器Ｅに戻り、サイクルを一巡する。
【００２５】
冷却水１６ｗは、第１の凝縮器Ｃ１から第２の凝縮器Ｃ２の順に通水する。まず第１の凝縮器Ｃ１に入った冷却水は、冷却水伝熱管１６ａで、第１の再生器Ｇ１で発生した冷媒蒸気から凝縮熱を奪って温度が上昇する。続いて第２の凝縮器Ｃ２に入った冷却水１６ｗは、冷却水伝熱管１６ｂで、第２の再生器Ｇ２で発生した冷媒蒸気から凝縮熱を奪ってさらに温度が上昇して出て行く。このため、第２の凝縮器Ｃ２より第１の凝縮器Ｃ１のほうが冷却水の温度が低いので、冷媒蒸気の凝縮温度が低くなる。すなわち凝縮圧力が小さくなる。第１の再生器Ｇ１と第１の凝縮器Ｃ１、および第２の再生器Ｇ２と第２の凝縮器Ｃ２はそれぞれ連通しており圧力が等しいので、第２の再生器Ｇ２と第２の凝縮器Ｃ２の缶胴より、第１の再生器Ｇ１と第１の凝縮器Ｃ１の缶胴のほうが、内圧が小さくなる。
【００２６】
排温水源である燃料電池３から送られてきた温水３１ｗは、前述のように、第２の再生器Ｇ２から第１の再生器Ｇ１の順に通水する。まず第２の再生器Ｇ２に入った温水３１ｗは温水伝熱管３１ｂで溶液を加熱し、自身は熱を失い温度が低下する。続いて第１の再生器Ｇ１に入った温水３１ｗは温水伝熱管３１ａで溶液を加熱し、さらに温度が低下して燃料電池３に戻る。
【００２７】
上述のように、第１の再生器Ｇ１と第１の凝縮器Ｃ１の缶胴は、通常の単効用サイクルの再生器／凝縮器缶胴に比べて内圧が低いので、第１の再生器Ｇ１の溶液の沸点が通常の単効用吸収冷凍機の場合よりも低くなる。すなわち再生器を加熱する熱源の温度が低くても良いため、温水の再生器出口温度が低くできる。したがって、燃料電池３のように、通常の単効用吸収冷凍機では使用し難い比較的温度の低い温水しか供給できない排温水源との組み合わせに適している。
【００２８】
図２のデューリング線図を参照して、第１の実施の形態の吸収冷凍機１０１ａの作用を説明する。各線図の横軸は溶液の温度、縦軸は冷媒の飽和温度を表している。以下の温度は具体的な比較例（ａ）と実施例（ｂ）として、温水の入り／戻り温度が７５／６５℃、冷却水の入り／戻り温度が３０／３５℃の場合のものを示す。例示する具体的な温度は（カッコ）内に示す。
【００２９】
（ａ）は比較例としての単効用サイクルを線図で表したもので、再生器の圧力は冷媒の凝縮温度Ｔｃ（３６℃）によって決められる。また、再生器の濃溶液温度Ｔｇは、熱源の温水の再生器出口温度（６５℃）から熱交換器での温度差（１℃）を差し引いたものになる（６５−１＝６４℃）。一方、吸収器の希溶液温度Ｔａ（３６℃）によって冷媒の蒸発圧力すなわち蒸発温度Ｔｅ（１５．５℃）が決められる。蒸発器でつくられる冷水の温度は、冷媒の蒸発温度に熱交換器での温度差（１℃）を加えたものになる（１５．５＋１＝１６．５℃）。
【００３０】
（ｂ）は図１の吸収冷凍機１０１ａのサイクルを線図に表したもので、第１の再生器Ｇ１の圧力は第１の凝縮器Ｃ１の凝縮温度Ｔｃ１（３３．５℃）によって、また、第２の再生器Ｇ２の圧力は第２の凝縮器Ｃ２の凝縮温度Ｔｃ２（３６℃）によって、それぞれ決められる。
【００３１】
第１、第２の再生器Ｇ１、Ｇ２の溶液温度Ｔｇ１、Ｔｇ２は、各々の再生器の温水出口温度（６５℃、７０℃）から、熱交換器での温度差（１℃）を差し引いたものになるため、それぞれＴｇ１（６４℃）、Ｔｇ２（６９℃）となり、（ａ）に示す単効用サイクルに比べて濃溶液と希溶液の濃度幅が大きくなる。これにより吸収器の希溶液温度Ｔａ（３６℃）に対して冷媒蒸発温度はＴｅ（１０．５℃）となり、蒸発器でつくられる冷水の温度は、Ｔｅに熱交換器での温度差（１℃）を加えたものになる（１０．５＋１＝１１．５℃）。すなわち（ａ）の単効用サイクルに比べて冷水温度を低くすることができる（１６．５−１１．５＝５℃）。
【００３２】
次に図３のフロー図及び図４のデューリング線図を参照して、本発明の第２の実施の形態の吸収冷凍機１０２ａ及び吸収冷凍システム１０２を説明する。
【００３３】
第２の実施の形態の吸収冷凍機１０２ａは、第１の実施の形態の吸収冷凍機１０１ａとは次の点で相違する。すなわち、第１の実施の形態が蒸発器Ｅと吸収器Ａを備えていたのに対して、第２の実施の形態は、互いに蒸発器同士が冷媒液の流れに対して直列に、また吸収器同士が吸収液の流れに対して直列に接続された、第１の蒸発器Ｅ１と第１の吸収器Ａ１、第２の蒸発器Ｅ２と第２の吸収器Ａ２を備えている。
第１の蒸発器Ｅ１と第１の吸収器Ａ１とは第３の缶胴に収納され、第２の蒸発器Ｅ２と第２の吸収器Ａ２とは、第３の缶胴とは別の第４の缶胴に収納されている。第３の缶胴と第４の缶胴とは、別体に構成されるか、仕切壁により隔離されている。したがって、両缶胴内の圧力は異ならせることができる。
【００３４】
上述のように、第１の実施の形態の吸収冷凍機１０１ａの蒸発器Ｅと吸収器Ａが、第１の蒸発器Ｅ１と第１の吸収器Ａ１、及び第２の蒸発器Ｅ２と第２の吸収器Ａ２に置き換えられている。第１の吸収器Ａ１と第２の吸収器Ａ２とは、中間濃度溶液配管１３ｃで接続されている。第２の吸収器Ａ２には、第１の実施の形態の吸収器Ａと同様に希溶液配管１４が接続され溶液ポンプ１１で希溶液を、第２の吸収器Ａ２から第１の再生器Ｇ１に送るように構成されている。
【００３５】
また冷却水配管１５は、第１の吸収器Ａ１の伝熱管１５ａと第２の吸収器Ａ２の伝熱管１５ｂとを直列に接続しており、伝熱管１５ａから伝熱管１５ｂへと流れるように構成されている。
【００３６】
冷媒配管１２は、冷媒配管１２ｃと１２ｄとに分岐しており、冷媒配管１２ｃは第１の蒸発器Ｅ１に、冷媒配管１２ｄは第２の蒸発器Ｅ２に、それぞれ接続されている。
【００３７】
また冷水配管４１は、第２の蒸発器Ｅ２の伝熱管４１ｂと第１の蒸発器Ｅ１の伝熱管４１ａとを直列に接続しており、伝熱管４１ｂから伝熱管４１ａへと流れるように構成されている。
【００３８】
第１再生器Ｇ１、第２再生器Ｇ２、第１凝縮器Ｃ１、第２凝縮器Ｃ２、溶液熱交換器１０、溶液ポンプ１１、冷媒配管１２、中間濃度溶液配管１３ａ、濃溶液配管１３ｂ、希溶液配管１４、冷却水１６、冷却水伝熱管１６ａ、１６ｂ、温水配管３１、温水伝熱管３１ａ、３１ｂ、冷水配管４１は、第１の実施の形態と同様であるので、重複した説明は省略する。排温水源である燃料電池３、室内空調機４も同様である。
【００３９】
続けて、吸収冷凍機１０２ａのサイクルについて説明する。第１の蒸発器Ｅ１で冷水伝熱管４１ａを流れる冷水４１ｗから熱を奪い蒸発した冷媒蒸気は、第１の吸収器Ａ１において冷却水伝熱管１５ａを流れる冷却水１５で冷却されている濃溶液に吸収される。冷媒を吸収して吸収剤の濃度が低下した中濃度溶液は、中間濃度溶液配管１３ｃを通して第２の吸収器Ａ２に送られ、第２の蒸発器Ｅ２で冷水伝熱管４１ｂを流れる冷水４１ｗから熱を奪い蒸発した冷媒蒸気は、第２の吸収器Ａ２において冷却水伝熱管１５ｂを流れる冷却水１５で冷却されている中濃度溶液に吸収される。冷媒を吸収して吸収剤の濃度が低下した希溶液は、溶液ポンプ１１によって溶液熱交換器１０に送られ、そこで第２の再生器Ｇ２から戻る高温の濃溶液と熱交換し、昇温して第１の再生器Ｇ１に入る。以降は第１の実施の形態と同じであるので重複した説明は省略する。
【００４０】
２つの吸収器用の冷却水１５ｗは、第１の吸収器Ａ１から第２の吸収器Ａ２の順に通水される。まず第１の吸収器Ａ１に入った冷却水１５ｗは、冷却水伝熱管１５ａで、第１の蒸発器Ｅ１で蒸発した冷媒蒸気の吸収熱で温度が上昇する。続いて第２の吸収器Ａ２に入った冷却水１５は、冷却水伝熱管１５ｂで、第２の蒸発器Ｅ２で蒸発した冷媒蒸気の吸収熱でさらに温度が上昇して出て行く。このため、第２の吸収器Ａ２より第１の吸収器Ａ１のほうが冷却水の温度が低くかつ溶液の濃度が濃いため、冷媒蒸気を吸収する力が強くなり、冷媒の蒸発圧力が低くなる。第１の吸収器Ａ１と第１の蒸発器Ｅ１、および第２の吸収器Ａ２と第２の蒸発器Ｅ２はそれぞれ一つの缶胴内で連通しており圧力が等しいので、第２の吸収器Ａ２と第２の蒸発器Ｅ２の缶胴より、第１の吸収器Ａ１と第１の蒸発器Ｅ１の缶胴のほうが、内圧が低くなる。
【００４１】
室内空調機４から送られてきた冷水４１ｗは、第２の蒸発器Ｅ２から第１の蒸発器Ｅ１の順に通水される。まず第２の蒸発器Ｅ２に入った冷水４１は冷水伝熱管４１ｂで冷媒を蒸発させ、自身は熱を失い温度が低下する。続いて第１の蒸発器Ｅ１に入った冷水４１は冷水伝熱管４１ａで冷媒を蒸発させ、さらに温度が低下して室内空調機４に戻る。
【００４２】
上述のように、第１の吸収器Ａ１と第１の蒸発器Ｅ１の缶胴は、通常の単効用サイクルの吸収器／蒸発器缶胴に比べて内圧が低いため、第１の蒸発器Ｅ１の冷媒の蒸発温度が低くなる。すなわち蒸発器Ｅ１で冷却される冷水の出口温度が低くできる。
【００４３】
２つの凝縮器の冷却水１６ｗおよび排温水源である燃料電池３からの温水３１の流れは第１の実施の形態と同様である。
【００４４】
図４のデューリング線図を参照して、第２の実施の形態の吸収冷凍機１０２ａの作用を説明する。図２と同様に、（ａ）（ｂ）各線図の横軸は溶液の温度、縦軸は冷媒の飽和温度を表している。以下の温度は具体的な比較例（ａ）と実施例（ｂ）として、温水の入り／戻り温度が７５／６５℃、冷却水の入り／戻り温度が３０／３５℃の場合のものを示す。例示する具体的な温度は（カッコ）内に示す。
【００４５】
（ａ）は比較例としての単効用サイクルを線図で表したもので、図２（ａ）と同様である。（ｂ）は、吸収冷凍機１０２ａのサイクルを線図に表したもので、第１の吸収器Ａ１の温度Ｔａ１によって第１の蒸発器Ｅ１の冷媒蒸発圧力すなわち冷媒蒸発温度Ｔｅ１が決められる。同様に、第２の吸収器Ａ２の温度Ｔａ２によって第２の蒸発器Ｅ２の冷媒蒸発圧力すなわち冷媒蒸発温度Ｔｅ２が決められる。再生器と凝縮器については図２（ｂ）に示す第１の実施の形態と同様であるので説明を省略する。
【００４６】
第１の吸収器Ａ１の温度（３３．５℃）は第２の吸収器Ａ２の温度（３６℃）より低いため、第１の蒸発器Ｅ１の冷媒蒸発温度Ｔｅ１（６．５℃）は第２の蒸発器Ｅ２の冷媒蒸発温度Ｔｅ２（１０．５℃）より低くなり、蒸発器でつくられる冷水の温度はＴｅ１に熱交換器での温度差（１℃）を加えたものとなる（６．５＋１＝７．５℃）。すなわち、蒸発器でつくられる冷水の温度を、図４（ａ）の通常の単効用サイクルよりＴｅ−Ｔｅ１に相当する温度だけ低くすることができる（１６．５−７．５＝９℃）。
【００４７】
このように、冷却水の通水順序を変更することで、吸収冷凍機の特性を変えることができる。例えば、冷却水を第１の吸収器Ａ１、第２の吸収器Ａ２、第１の凝縮器Ｃ１、第２の凝縮器Ｃ２、の順に通水すると、吸収器および凝縮器の温度はＴａ１＜Ｔａ２＜Ｔｃ１＜Ｔｃ２となり、第１の吸収器Ａ１の温度が低くなるので第１の吸収器Ａ１／第１の蒸発器Ｅ１の缶胴の圧力が低くなり、第１の蒸発器Ｅ１の冷媒蒸発温度Ｔｅ１が低くなるため、冷水出口温度を低くすることができる。
【００４８】
また、冷却水を第１の凝縮器Ｃ１、第２の凝縮器Ｃ２、第１の吸収器Ａ１、第２の吸収器Ａ２、の順に通水すると、吸収器および凝縮器の温度はＴｃ１＜Ｔｃ２＜Ｔａ１＜Ｔａ２となり、第１の凝縮器Ｃ１の温度が低くなるので第１の凝縮器Ｃ１／第１再生器Ｇ１缶胴の圧力が低くなり、第１の再生器Ｇ１の濃溶液温度Ｔｇ１が低くなるため、熱源温水の第１の再生器出口温度を低くすることができる。
【００４９】
さらに、冷却水を第１の吸収器Ａ１と第２の吸収器Ａ２および第１の凝縮器Ｃ１と第２の凝縮器Ｃ２に並列に通水すると、吸収器および凝縮器の温度はＴｃ１＝Ｔａ１＜Ｔｃ２＝Ｔａ２となり、第１の吸収器Ａ１の温度が低く、かつ第１の凝縮器Ｃ１の温度が低くなるので、上記２者の特性を併せ持たせることができるため、冷水出口温度が低く、かつ熱源温水の再生器出口温度が低くすることができる。
【００５０】
以上説明した本発明の実施の形態は、以下のような特徴を有する。
吸収冷凍機１０１ａ、１０２ａの作動媒体はリチウムブロマイドと水、水とアンモニアに限らず、熱源の温度、欲しい冷熱媒体の温度、冷凍容量等に従って適切なものを選択すればよい。
加熱源としての外部熱源装置は、燃料電池に限らず、例えばガスタービンやガスエンジンなどであってもよい。排熱の形態も、温水に限らず、水蒸気、排ガス等であってもよい。
冷凍負荷は、冷房の室内機に限らず、例えば冷蔵・冷蔵庫やショーケース等であってもよい。冷熱媒体は、冷水に限らず、例えばブラインやフロンなどの冷媒でもあってもよい。各機器は１台に限らず複数であっても良い。
【００５１】
以上説明した本発明の実施の形態は、従来の技術との関連において、以下のような利点を有する。本発明の実施の形態によれば、吸収冷凍機の再生器および凝縮器を複数に分割し、凝縮器に供給する冷却水を直列に利用、即ちカスケード利用することによって、各々の缶胴内の圧力を変えることができるため、冷却水温が低い凝縮器に対応する再生器の溶液温度が低くなる。熱源温水を、冷却水温が高い凝縮器に対応する再生器から、冷却水温が低い凝縮器に対応する再生器に向かって流すことによって、熱源温水をより低温まで利用できるため、入口と出口の温度差が大きい熱源温水の持つエネルギーを高温から低温まで有効に利用することが可能になる。
また同様に、吸収器および蒸発器を複数に分割し、吸収器に供給する冷却水をカスケード利用することによって、各々の缶胴内の圧力を変えることができるため、冷却水温が低い吸収器に対応する蒸発器の冷媒蒸発温度が低くなる。冷水を、冷却水温が高い吸収器に対応する蒸発器から、冷却水温が低い吸収器に対応する蒸発器に向かって流すことによって、冷水をより低温まで冷却することが可能になる。
さらにこれらを組み合わせ、冷却水の通水順序を変えることによって、冷水温度の低いサイクルや、熱源温水をより低温まで利用できるサイクルなど、様々な特性のサイクルを得ることができる。
【００５２】
【発明の効果】
以上のように本発明によれば、加熱媒体を、第２の発生器と第１の発生器に、この順に直列に流し、第１の冷却媒体を、第１の凝縮器と第２の凝縮器に、この順に直列に流すように構成するので、加熱媒体の出入り口温度差が大きい場合に、その排熱を有効に使うことができる吸収冷凍機を提供することが可能となる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態である吸収冷凍機及びそれを含む吸収冷凍システムのフロー図である。
【図２】比較例の単効用の吸収冷凍機と、図１に示す第１の実施の形態の吸収冷凍機のデューリング線図である。
【図３】本発明の第２の実施の形態である吸収冷凍機及びそれを含む吸収冷凍システムのフロー図である。
【図４】比較例の単効用の吸収冷凍機と、図３に示す第２の実施の形態の吸収冷凍機のデューリング線図である。
【符号の説明】
３燃料電池
４空調負荷
１０溶液熱交換器
１１溶液ポンプ
１２冷媒配管
１３ａ中間濃度溶液配管
１３ｂ濃溶液配管
１４希溶液配管
１５、１６冷却水配管
１５ａ、１６ａ冷却水伝熱管
１５ｗ、１６ｗ冷却水
３１温水配管
３１ｗ温水
３１ａ、３１ｂ温水伝熱管
４１冷水配管
４１ａ冷水伝熱管
４１ｗ冷水
１０１、１０２吸収冷凍システム
１０１ａ、１０２ａ吸収冷凍機
Ｅ蒸発器
Ｅ１第１の蒸発器
Ｅ２第２の蒸発器
Ａ吸収器
Ａ１第１の吸収器
Ａ２第２の吸収器
Ｇ再生器
Ｇ１第１の再生器
Ｇ２第２の再生器
Ｃ凝縮器
Ｃ１第１の凝縮器
Ｃ２第２の凝縮器[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an absorption chiller and a refrigeration system including the absorption chiller, and more particularly to an absorption chiller capable of efficiently producing cold heat by effectively using exhaust heat having a large temperature difference, and a refrigeration system including such a refrigerator. Things.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there has been an absorption refrigerator operated by exhaust gas or waste water discharged along with power generation in a cogeneration system. Exhaust gas emitted from a gas engine or a gas turbine has a relatively high temperature of 200 to 300 ° C., so that the exhaust gas generates steam at about 150 ° C. It is generally known to operate a heavy duty absorption refrigerator. The temperature of jacketed hot water such as gas engine / gasoline engine / diesel engine or hot water obtained by a solar heat collector is 80 to 90 ° C., and is a single-effect absorption refrigerator, Genelink, double-effect. A device used as a heat source such as an absorption refrigerator is generally known (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-08-54156 (FIGS. 1 and 2)
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional apparatus, it is difficult to use exhaust heat having a large temperature difference between an entrance and an exit.On the other hand, exhaust heat water from an engine or a fuel cell is itself cooling water for an engine or a fuel cell. Therefore, it is necessary to cool down to a low temperature and return. In addition, there is a demand for increasing the temperature difference between the inlet and the outlet of the circulating heat medium (heating fluid) in order to reduce the transport power of the waste hot water, but the conventional apparatus has not been able to cope with this.
[0005]
Therefore, the present invention provides an absorption refrigerator having an absorption refrigerator capable of efficiently producing cold heat by effectively using the waste heat when the temperature difference between the entrance and exit of the heating medium is large, and an absorption refrigerator having such an absorption refrigerator. It is an object.
[0006]
[Means for Solving the Problems]
To achieve the above object, an absorption refrigerator according to the first aspect of the present invention includes, as shown in FIG. 1, a first generator G1 for heating and concentrating an absorption liquid with a heating medium 31w; A first condenser C1 for cooling and condensing the refrigerant vapor generated in the first generator G1 with the first cooling medium 16w; and heating the absorbent concentrated in the first generator G1 with the heating medium 31w. A second generator G2 for further concentrating; and a second condenser C2 for cooling and condensing the refrigerant vapor generated by the second generator G2 with the first cooling medium 16w; So that the first cooling medium 16w flows in series to the first condenser C1 and the second condenser C2 in this order to the second generator G2 and the first generator G1. Be composed.
[0007]
Typically, an evaporator E that receives the refrigerant condensed in the first condenser C1 and the refrigerant condensed in the second condenser C2 and evaporates the refrigerant to cool the cooling medium 41w; An absorber A is provided for receiving the concentrated absorbent in the second generator G2 and absorbing the refrigerant evaporated in the evaporator E. Further, a heat exchanger 10 for exchanging heat between the absorbing liquid sent from the absorber A to the first generator G1 and the absorbing liquid returning to the absorber A from the second generator G2 is provided. The generator and the condenser are not limited to the first and the second, but may include a third or more.
[0008]
With this configuration, the heating medium flows through the second generator and the first generator in series in this order, and the first cooling medium flows through the first condenser and the second condenser. Since it is configured to flow in series in order, when the temperature difference between the entrance and exit of the heating medium is large, the waste heat can be used effectively.
[0009]
Further, as described in claim 2 and, for example, as shown in FIG. 3, in the absorption refrigerator according to claim 1, the refrigerant condensed in the first condenser C1 and the refrigerant condensed in the second condenser C2. And a first evaporator E1 for evaporating the refrigerant to cool the cooling medium 41w; a refrigerant condensed in the first condenser C1 and a condensed refrigerant in the second condenser C2. A second evaporator E2 for receiving the refrigerant and evaporating the refrigerant to cool the cooling medium; and for receiving the absorbent concentrated in the second generator G2 and distributing the absorbent to the second cooling medium. A first absorber A1 for absorbing the refrigerant evaporated in the first evaporator E1 with the absorbing liquid while cooling at 15 w; receiving the absorbing liquid absorbing the refrigerant in the first absorber A1, Is cooled by the second evaporator E2 with the absorbing liquid while cooling with the second cooling medium 15w. A second and a absorber A2 to absorb; cold heat medium 41w, a second evaporator E2 the first evaporator E1, may be configured to flow in this order in series.
[0010]
Typically, the second cooling medium 15w flows in series through the first absorber A1 and the second absorber A2 in this order. Also, typically, heat exchange between the absorbing liquid sent from the second absorber A2 to the first generator G1 and the absorbing liquid returning from the second generator G2 to the first absorber A1. An exchange 10 is provided. Here, the absorber and the evaporator are not limited to the first and the second, and may include a third or more.
Further, the first cooling medium and the second cooling medium may be supplied from the same system. Typically, it is, for example, cooling water supplied from the same cooling tower.
[0011]
In order to achieve the above object, an absorption refrigeration system according to the third aspect of the present invention includes, as shown in FIGS. 1 and 2, for example, absorption chillers 101a and 102a according to the first or second aspect; A heating source 3 for supplying the medium 31w.
[0012]
Further, as described in claim 4, in the absorption refrigeration system according to claim 3, the heating source may be a fuel cell.
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each of the drawings, the same or corresponding members are denoted by the same or similar reference numerals, and redundant description will be omitted.
[0013]
With reference to the flowchart of FIG. 1, an absorption refrigeration machine according to a first embodiment of the present invention and an absorption refrigeration system including the same will be described. The absorption refrigerating system 101 according to the embodiment of the present invention includes the absorption refrigerating machine 101a and an external heat source device as a heating source, specifically, the fuel cell 3. As a working medium of the absorption refrigerator 101a, a combination of an absorbent and a refrigerant is used. In the present embodiment, lithium bromide, which is currently most widely used in various absorption refrigerators, is used as an absorbent, and water is used as a refrigerant of the present invention. However, the invention is not limited to this. For example, water may be used as the absorbent and ammonia may be used as the refrigerant.
[0014]
The absorption refrigerator 101a used in the present embodiment is an absorption refrigerator similar to a single-effect absorption refrigerator. Although it is provided with a plurality of regenerators, it is distinguished from a double-effect absorption refrigerator that uses the refrigerant vapor evaporated in the first regenerator as a heating medium for the second regenerator. The absorption refrigerator 101a includes an evaporator E that evaporates water as a refrigerant and cools the cold water 41w as a cold heat source medium. The evaporator E has a heat transfer section, but in the present embodiment, a cold water heat transfer tube 41a is employed as the heat transfer section. In the evaporator E, the cold water 41w flowing inside the cold water heat transfer tube 41a is cooled. A cold water pipe 41 for supplying cold water 41w is connected to the evaporator E.
[0015]
Further, the absorption refrigerator 101a heats an absorber A that absorbs the refrigerant evaporated by the evaporator E and an absorbing liquid (a mixture of an absorbent and a refrigerant, hereinafter also referred to as a “solution” as appropriate) sent from the absorber A. The apparatus includes a first regenerator G1 for generating a refrigerant gas, and a second regenerator G2 for receiving an absorbent concentrated to some extent in the first regenerator G1 and heating it to generate a refrigerant gas. Further, the absorption refrigerator 101a condenses the refrigerant gas generated in the first regenerator G1 and sends the condensed refrigerant liquid to the evaporator E, which is generated in the first condenser C1 and the second regenerator G2. A second condenser C2 for condensing the refrigerant gas and sending the condensed refrigerant liquid to the evaporator E;
[0016]
The first regenerator G1 and the first condenser C1 are housed in a first can body, and the second regenerator G2 and the second condenser C2 are provided in a first can body different from the first can body. 2 cans. The first can body and the second can body are configured separately or separated by a partition wall. Therefore, the pressures in both can bodies can be different from each other.
[0017]
The absorber A has a cooling water heat transfer tube 15a as a heat transfer portion, and is scattered to the outside of the cooling water heat transfer tube 15a by a cooling fluid as a second cooling medium flowing through the inside, specifically, the cooling water 15w. Cool the solution.
The regenerators G1 and G2 have hot water heat transfer tubes 31a and 31b, respectively, as heat transfer portions, and each of the regenerators G1 and G2 is a heating fluid as an external heat source medium flowing therethrough, specifically, hot water. The solution that is stored in the hot water heat transfer tubes 31a and 31b is heated.
The condensers C1 and C2 have cooling water heat transfer tubes 16a and 16b as heat transfer portions, respectively, and a cooling fluid as a first cooling medium flowing through the inside thereof, specifically, the cooling water 16w, and the cooling water heat transfer tubes 16a and 16b. , 16b to take heat from the refrigerant gas existing outside and condense.
Hereinafter, the cold water heat transfer tubes 41a, the cooling water heat transfer tubes 15a, 16a, 16b, and the hot water heat transfer tubes 31a, 31b will be simply referred to as heat transfer tubes 41a, heat transfer tubes 15a, 16a, 16b, and heat transfer tubes 31a, 31b unless otherwise confused.
[0018]
A cooling water pipe 15 for supplying cooling water 15w is connected to the absorber A, and a hot water pipe 31 for supplying hot water 31w is connected to the first and second regenerators G1 and G2. A cooling water pipe 16 that supplies cooling water 16w is connected to the first and second condensers C1 and C2, respectively.
Further, the first regenerator G1 and the second regenerator G2 are an intermediate concentration solution for returning the intermediate concentration absorbent, which is the absorbent regenerated to some extent in the first regenerator G1, to the second regenerator G2. The second regenerator G2 and the absorber A are connected by a pipe 13a, and are connected by a concentrated solution pipe 13b that returns the solution regenerated by the second regenerator G2 to the absorber A. In addition, the absorber A and the first regenerator G1 are connected by a dilute solution pipe 14 that sends a solution that has become a dilute solution by absorbing the refrigerant in the absorber A to the first regenerator G1. The solution heat exchanger 10 is inserted and arranged in the concentrated solution pipe 13b and the diluted solution pipe 14, and the concentrated solution returned from the second regenerator G2 to the absorber A and the first solution from the absorber A to the first regenerator G1. Is configured to perform heat exchange with the dilute solution sent to
[0019]
The first regenerator G1 is located higher than the second regenerator G2, the second regenerator G2 is located higher than the absorber A, and the operating pressure of the two regenerators G1 and G2 is higher. Is higher than that of absorber A. Therefore, the solution pump 11 is inserted and disposed in the dilute solution pipe 14, and the solution can be sent from the absorber A to the first regenerator G1 through the dilute solution pipe 14. The transfer of the intermediate-concentration solution and the concentrated solution from the first and second regenerators G1 and G2 to the absorber A through the intermediate-concentration solution pipe 13a and the concentrated-solution pipe 13 is performed by gravity and a pressure difference between the devices. Is
[0020]
The absorption refrigerator 101a further includes a refrigerant pipe 12a for returning the refrigerant liquid condensed in the first condenser C1 to the evaporator E, and a refrigerant pipe 12b for returning the refrigerant liquid condensed in the second condenser C2 to the evaporator E. Is provided. In this drawing, the case where the refrigerant pipes 12a and 12b join the refrigerant pipe 12 and return to the evaporator E is shown. However, the refrigerant pipes 12a and 12b are separately connected to the evaporator E to They may be returned separately.
[0021]
Outside the absorption refrigerator 101a, there is an indoor air conditioner 4 as a chilled water load, and the indoor air conditioner 4 and the evaporator E are connected by a chilled water pipe 41. With such a configuration, the cold water 41w flowing through the cold water pipe 41 is configured to circulate between the indoor air conditioner 4 and the absorption compression refrigeration apparatus 101.
[0022]
Outside the absorption refrigerator 101a, there is a fuel cell 3 as an external heat source device, and the fuel cell 3 is connected to the second regenerator G2 and the first regenerator G1 by a hot water pipe 31. The heat transfer tube 31b of the first regenerator G2 and the heat transfer tube 31a of the first regenerator G1 are connected in series in this order from the upstream side of the flow of hot water by the hot water pipe 31. Therefore, the hot water 31w flowing through the hot water pipe 31 flows in the order of the fuel cell 3, the hot water heat transfer tube 31b of the second regenerator G2, and the hot water heat transfer tube 31a of the first regenerator G1, and returns to the fuel cell 3. Thus, the hot water 31w is configured to circulate between the fuel cell 3 and the absorption refrigerator 101a.
[0023]
With reference to FIG. 1, a cycle (two-stage regeneration cycle) of the absorption chiller 101a in the first embodiment will be described. The refrigerant vapor, which has taken heat from the cold water 41w flowing through the cold water heat transfer tube 41a in the evaporator E and evaporated, is absorbed by the solution cooled by the cooling water 15w flowing through the cooling water heat transfer tube 15a in the absorber A. The solution in the absorber A is sprayed on the cold water heat transfer tube 15a by a pump (not shown). The sprayed solution accumulates at the bottom of the absorber A and is again sucked and sprayed by the pump.
[0024]
The dilute solution in which the concentration of the absorbent has been reduced by absorbing the refrigerant is sent to the solution heat exchanger 10 by the solution pump 11, where it exchanges heat with the high-temperature concentrated solution returned from the second regenerator G2, and the temperature rises. To enter the first regenerator G1. In the first regenerator G1, the solution is heated by the hot water 31w flowing through the hot water heat transfer tube 31a, and the refrigerant is discharged and concentrated to become a medium concentration solution. The medium-concentration solution enters the second regenerator G2, is heated by the hot water 31w flowing through the hot-water heat transfer tube 31b, releases refrigerant vapor, and is concentrated to become a concentrated solution. The concentrated solution recovers heat in the solution heat exchanger 10, lowers the temperature and returns to the absorber A. On the other hand, the refrigerant vapor generated in the first generator G1 is cooled and condensed by the cooling water 16w flowing through the cooling water heat transfer tube 16a in the first condenser C1. Similarly, the refrigerant vapor generated in the second generator G2 is cooled and condensed by the cooling water 16 flowing through the cooling water heat transfer tube 16b in the second condenser C2. These condensed refrigerant liquids merge and return to the evaporator E to make a cycle.
[0025]
The cooling water 16w flows in the order from the first condenser C1 to the second condenser C2. First, the cooling water that has entered the first condenser C1 deprives the refrigerant vapor generated in the first regenerator G1 of heat of condensation in the cooling water heat transfer tube 16a, and the temperature rises. Subsequently, the cooling water 16w that has entered the second condenser C2 takes the heat of condensation from the refrigerant vapor generated in the second regenerator G2 in the cooling water heat transfer tube 16b, and the temperature further rises and exits. For this reason, since the temperature of the cooling water is lower in the first condenser C1 than in the second condenser C2, the condensation temperature of the refrigerant vapor is lower. That is, the condensation pressure is reduced. Since the first regenerator G1 and the first condenser C1 and the second regenerator G2 and the second condenser C2 are in communication with each other and have the same pressure, the second regenerator G2 and the second condenser C2 have the same pressure. The inner pressure of the can body of the first regenerator G1 and the first condenser C1 is smaller than that of the can body of the vessel C2.
[0026]
As described above, the hot water 31w sent from the fuel cell 3, which is a waste hot water source, flows through the second regenerator G2 to the first regenerator G1 in this order. First, the hot water 31w that has entered the second regenerator G2 heats the solution with the hot water heat transfer tube 31b, and loses its own heat to lower the temperature. Subsequently, the hot water 31w that has entered the first regenerator G1 heats the solution with the hot water heat transfer tube 31a, and the temperature further decreases and returns to the fuel cell 3.
[0027]
As described above, the first regenerator G1 and the first condenser C1 can body have a lower internal pressure as compared with a normal single-effect cycle regenerator / condenser can body, so that the first regenerator G1 has a lower internal pressure. Has a lower boiling point than that of a normal single-effect absorption refrigerator. That is, since the temperature of the heat source for heating the regenerator may be low, the outlet temperature of the regenerator of the hot water can be lowered. Therefore, it is suitable for combination with a waste heat water source that can supply only relatively low-temperature hot water that is difficult to use in a normal single-effect absorption refrigerator as in the fuel cell 3.
[0028]
The operation of the absorption refrigerator 101a according to the first embodiment will be described with reference to the During diagram of FIG. The horizontal axis of each diagram represents the temperature of the solution, and the vertical axis represents the saturation temperature of the refrigerant. The following temperatures are shown as specific comparative examples (a) and examples (b) when the hot water entry / return temperature is 75/65 ° C and the cooling water entry / return temperature is 30/35 ° C. . Illustrative specific temperatures are shown in parentheses.
[0029]
(A) is a diagram illustrating a single-effect cycle as a comparative example, in which the pressure of the regenerator is determined by the condensation temperature Tc (36 ° C.) of the refrigerant. Further, the concentrated solution temperature Tg of the regenerator is obtained by subtracting the temperature difference (1 ° C.) in the heat exchanger from the regenerator outlet temperature (65 ° C.) of the hot water of the heat source (65-1 = 64 ° C.). On the other hand, the evaporation pressure of the refrigerant, that is, the evaporation temperature Te (15.5 ° C.) is determined by the dilute solution temperature Ta (36 ° C.) of the absorber. The temperature of the cold water produced by the evaporator is the sum of the evaporation temperature of the refrigerant and the temperature difference (1 ° C.) in the heat exchanger (15.5 + 1 = 16.5 ° C.).
[0030]
(B) is a diagram showing the cycle of the absorption refrigerator 101a of FIG. 1 in which the pressure of the first regenerator G1 depends on the condensation temperature Tc1 (33.5 ° C.) of the first condenser C1, and , The pressure of the second regenerator G2 is determined by the condensation temperature Tc2 (36 ° C.) of the second condenser C2.
[0031]
The solution temperature Tg1, Tg2 of the first and second regenerators G1, G2 was obtained by subtracting the temperature difference (1 ° C.) in the heat exchanger from the hot water outlet temperature (65 ° C., 70 ° C.) of each regenerator. Tg1 (64 ° C.) and Tg2 (69 ° C.), respectively, and the concentration range of the concentrated solution and the dilute solution is larger than in the single-effect cycle shown in FIG. As a result, the refrigerant evaporation temperature becomes Te (10.5 ° C.) with respect to the dilute solution temperature Ta (36 ° C.) of the absorber, and the temperature of the cold water produced by the evaporator becomes equal to the temperature difference (1) in the heat exchanger. ° C) (10.5 + 1 = 11.5 ° C). That is, the chilled water temperature can be lowered as compared with the single-effect cycle (a) (16.5-11.5 = 5 ° C.).
[0032]
Next, an absorption refrigerator 102a and an absorption refrigeration system 102 according to a second embodiment of the present invention will be described with reference to the flowchart of FIG. 3 and the During diagram of FIG.
[0033]
The absorption refrigerator 102a of the second embodiment is different from the absorption refrigerator 101a of the first embodiment in the following points. That is, while the first embodiment has the evaporator E and the absorber A, the second embodiment has two evaporators in series with each other with respect to the flow of the refrigerant liquid, A first evaporator E1 and a first absorber A1, and a second evaporator E2 and a second absorber A2 are connected in series with respect to the flow of the absorbing liquid.
The first evaporator E1 and the first absorber A1 are housed in a third can body, and the second evaporator E2 and the second absorber A2 are separate from the third can body. 4 cans. The third can body and the fourth can body are formed separately or separated by a partition wall. Therefore, the pressures in both can bodies can be different.
[0034]
As described above, the evaporator E and the absorber A of the absorption refrigerator 101a according to the first embodiment include the first evaporator E1 and the first absorber A1, and the second evaporator E2 and the second evaporator E2. Is replaced by the absorber A2. The first absorber A1 and the second absorber A2 are connected by an intermediate concentration solution pipe 13c. A dilute solution pipe 14 is connected to the second absorber A2 similarly to the absorber A of the first embodiment, and the dilute solution is supplied by the solution pump 11 from the second absorber A2 to the first regenerator G1. It is configured to send to.
[0035]
The cooling water pipe 15 connects the heat transfer tube 15a of the first absorber A1 and the heat transfer tube 15b of the second absorber A2 in series, and is configured to flow from the heat transfer tube 15a to the heat transfer tube 15b. Have been.
[0036]
The refrigerant pipe 12 branches into refrigerant pipes 12c and 12d, and the refrigerant pipe 12c is connected to a first evaporator E1, and the refrigerant pipe 12d is connected to a second evaporator E2.
[0037]
The cold water pipe 41 connects the heat transfer tube 41b of the second evaporator E2 and the heat transfer tube 41a of the first evaporator E1 in series, and is configured to flow from the heat transfer tube 41b to the heat transfer tube 41a. ing.
[0038]
First regenerator G1, second regenerator G2, first condenser C1, second condenser C2, solution heat exchanger 10, solution pump 11, refrigerant pipe 12, intermediate concentration solution pipe 13a, concentrated solution pipe 13b, diluted The solution pipe 14, the cooling water 16, the cooling water heat transfer pipes 16a and 16b, the hot water pipe 31, the hot water heat transfer pipes 31a and 31b, and the cold water pipe 41 are the same as those in the first embodiment, and thus the duplicated description will be omitted. . The same applies to the fuel cell 3 and the indoor air conditioner 4 which are the waste water sources.
[0039]
Next, the cycle of the absorption refrigerator 102a will be described. In the first evaporator E1, the refrigerant vapor that has taken heat from the cold water 41w flowing through the cold water heat transfer tube 41a to evaporate is converted into a concentrated solution cooled by the cooling water 15 flowing through the cooling water heat transfer tube 15a in the first absorber A1. Absorbed. The medium-concentration solution in which the concentration of the absorbent has been reduced by absorbing the refrigerant is sent to the second absorber A2 through the intermediate-concentration solution pipe 13c, and the second evaporator E2 generates heat from the cold water 41w flowing through the cold water heat transfer tube 41b. The evaporated refrigerant vapor is absorbed by the medium concentration solution cooled by the cooling water 15 flowing through the cooling water heat transfer tube 15b in the second absorber A2. The dilute solution in which the concentration of the absorbent has been reduced by absorbing the refrigerant is sent to the solution heat exchanger 10 by the solution pump 11, where it exchanges heat with the high-temperature concentrated solution returned from the second regenerator G2, and the temperature rises. To enter the first regenerator G1. Subsequent steps are the same as those in the first embodiment, and a duplicate description will be omitted.
[0040]
The cooling water 15w for the two absorbers is passed in order from the first absorber A1 to the second absorber A2. First, the temperature of the cooling water 15w that has entered the first absorber A1 rises in the cooling water heat transfer tube 15a due to the heat absorbed by the refrigerant vapor evaporated in the first evaporator E1. Subsequently, the cooling water 15 that has entered the second absorber A2 further exits in the cooling water heat transfer tube 15b due to the absorption heat of the refrigerant vapor evaporated in the second evaporator E2. For this reason, since the temperature of the cooling water is lower and the concentration of the solution is higher in the first absorber A1 than in the second absorber A2, the power for absorbing the refrigerant vapor is increased, and the evaporation pressure of the refrigerant is reduced. Since the first absorber A1 and the first evaporator E1 and the second absorber A2 and the second evaporator E2 communicate with each other in one can body and have the same pressure, the second absorber is used. The inner pressure of the can body of the first absorber A1 and the first evaporator E1 is lower than that of the can body of A2 and the second evaporator E2.
[0041]
The cold water 41w sent from the indoor air conditioner 4 is passed through in order from the second evaporator E2 to the first evaporator E1. First, the chilled water 41 that has entered the second evaporator E2 evaporates the refrigerant in the chilled water heat transfer tube 41b, and loses its own heat to lower its temperature. Subsequently, the chilled water 41 that has entered the first evaporator E1 evaporates the refrigerant in the chilled water heat transfer tube 41a, and the temperature is further reduced to return to the indoor air conditioner 4.
[0042]
As described above, since the inner pressure of the can body of the first absorber A1 and the first evaporator E1 is lower than that of the normal single-effect cycle absorber / evaporator can body, the first evaporator E1 has a lower internal pressure. The evaporation temperature of the refrigerant decreases. That is, the outlet temperature of the cold water cooled by the evaporator E1 can be lowered.
[0043]
The flow of the cooling water 16w of the two condensers and the flow of the hot water 31 from the fuel cell 3, which is the exhaust hot water source, are the same as in the first embodiment.
[0044]
The operation of the absorption refrigerator 102a according to the second embodiment will be described with reference to the During diagram of FIG. As in FIG. 2, the horizontal axis of each diagram (a) and (b) represents the temperature of the solution, and the vertical axis represents the saturation temperature of the refrigerant. The following temperatures are shown as specific comparative examples (a) and examples (b) when the hot water entry / return temperature is 75/65 ° C and the cooling water entry / return temperature is 30/35 ° C. . Illustrative specific temperatures are shown in parentheses.
[0045]
FIG. 2A is a diagram showing a single-effect cycle as a comparative example, which is the same as FIG. 2A. (B) is a diagram showing a cycle of the absorption refrigerator 102a, and the refrigerant evaporation pressure of the first evaporator E1, that is, the refrigerant evaporation temperature Te1 is determined by the temperature Ta1 of the first absorber A1. Similarly, the refrigerant evaporation pressure of the second evaporator E2, that is, the refrigerant evaporation temperature Te2 is determined by the temperature Ta2 of the second absorber A2. The regenerator and the condenser are the same as in the first embodiment shown in FIG.
[0046]
Since the temperature (33.5 ° C.) of the first absorber A1 is lower than the temperature (36 ° C.) of the second absorber A2, the refrigerant evaporation temperature Te1 (6.5 ° C.) of the first evaporator E1 is equal to the second temperature. 2 becomes lower than the refrigerant evaporation temperature Te2 (10.5 ° C.) of the evaporator E2, and the temperature of the cold water produced by the evaporator becomes Te1 plus the temperature difference (1 ° C.) in the heat exchanger (6). 0.5 + 1 = 7.5 ° C.). That is, the temperature of the cold water produced by the evaporator can be made lower than the normal single-effect cycle of FIG. 4A by a temperature corresponding to Te-Te1 (16.5-7.5 = 9 ° C.).
[0047]
Thus, by changing the flow of the cooling water, the characteristics of the absorption refrigerator can be changed. For example, when cooling water is passed in the order of the first absorber A1, the second absorber A2, the first condenser C1, and the second condenser C2, the temperature of the absorber and the condenser becomes Ta1 <Ta2. <Tc1 <Tc2, and the temperature of the first absorber A1 decreases, so the pressure of the can body of the first absorber A1 / first evaporator E1 decreases, and the refrigerant evaporation temperature of the first evaporator E1 Since Te1 decreases, the cold water outlet temperature can be reduced.
[0048]
Further, when the cooling water flows in the order of the first condenser C1, the second condenser C2, the first absorber A1, the second absorber A2, the temperature of the absorber and the condenser becomes Tc1 <Tc2. <Ta1 <Ta2, and the temperature of the first condenser C1 becomes lower, so that the pressure of the can body of the first condenser C1 / the first regenerator G1 becomes lower, and the concentrated solution temperature Tg1 of the first regenerator G1 becomes lower. As a result, the temperature of the first regenerator outlet of the heat source hot water can be lowered.
[0049]
Further, when cooling water is passed in parallel to the first absorber A1 and the second absorber A2 and to the first condenser C1 and the second condenser C2, the temperature of the absorber and the condenser becomes Tc1 = Ta1. <Tc2 = Ta2, and the temperature of the first absorber A1 is low and the temperature of the first condenser C1 is low, so that the characteristics of the two can be combined. In addition, the regenerator outlet temperature of the heat source hot water can be reduced.
[0050]
The embodiment of the present invention described above has the following features.
The working medium of the absorption chillers 101a and 102a is not limited to lithium bromide and water, water and ammonia, and an appropriate one may be selected according to the temperature of the heat source, the temperature of the desired cooling medium, the refrigerating capacity, and the like.
The external heat source device as the heating source is not limited to the fuel cell, and may be, for example, a gas turbine or a gas engine. The form of the exhaust heat is not limited to hot water, but may be steam, exhaust gas, or the like.
The refrigerating load is not limited to the indoor unit for cooling, and may be, for example, a refrigerator / refrigerator, a showcase, or the like. The cooling medium is not limited to cold water, and may be a coolant such as brine or chlorofluorocarbon. The number of each device is not limited to one and may be plural.
[0051]
The embodiment of the present invention described above has the following advantages in relation to the related art. According to the embodiment of the present invention, the regenerator and the condenser of the absorption refrigerator are divided into a plurality of parts, and the cooling water supplied to the condenser is used in series, that is, by using the cascade, so that the inside of each can body is reduced. Since the pressure can be changed, the solution temperature of the regenerator corresponding to the condenser having a low cooling water temperature is lowered. By flowing the heat source hot water from the regenerator corresponding to the condenser with the higher cooling water temperature to the regenerator corresponding to the condenser with the lower cooling water temperature, the heat source hot water can be used to a lower temperature. The energy of the heat source hot water having a large difference can be effectively used from a high temperature to a low temperature.
Similarly, the pressure in each can body can be changed by dividing the absorber and evaporator into a plurality and using the cooling water supplied to the absorber in cascade, so that the cooling water temperature can be reduced to an absorber. The corresponding refrigerant evaporator has a lower refrigerant evaporation temperature. By flowing cold water from an evaporator corresponding to an absorber having a high cooling water temperature to an evaporator corresponding to an absorber having a low cooling water temperature, it is possible to cool the cold water to a lower temperature.
Further, by combining these and changing the flow of the cooling water, it is possible to obtain a cycle having various characteristics such as a cycle in which the temperature of the cold water is low and a cycle in which the heat source hot water can be used to a lower temperature.
[0052]
【The invention's effect】
As described above, according to the present invention, the heating medium is flowed in series to the second generator and the first generator in this order, and the first cooling medium is supplied to the first condenser and the second condenser. Since it is configured to flow in series in this order in the vessel, it is possible to provide an absorption refrigerator capable of effectively using the exhaust heat when the temperature difference between the inlet and outlet of the heating medium is large.
[Brief description of the drawings]
FIG. 1 is a flow chart of an absorption chiller according to a first embodiment of the present invention and an absorption refrigeration system including the same.
FIG. 2 is a During diagram of a single-effect absorption refrigerator of a comparative example and the absorption refrigerator of the first embodiment shown in FIG.
FIG. 3 is a flow chart of an absorption refrigerator and an absorption refrigeration system including the same according to a second embodiment of the present invention.
4 is a During diagram of a single-effect absorption refrigerator of a comparative example and the absorption refrigerator of the second embodiment shown in FIG.
[Explanation of symbols]
3 Fuel cell
4 Air conditioning load
10 Solution heat exchanger
11 Solution pump
12 refrigerant piping
13a Intermediate concentration solution piping
13b Concentrated solution piping
14 Dilute solution piping
15, 16 Cooling water piping
15a, 16a Cooling water heat transfer tube
15w, 16w cooling water
31 Hot water piping
31w hot water
31a, 31b Hot water heat transfer tube
41 Cold water piping
41a Cold water heat transfer tube
41w cold water
101, 102 Absorption refrigeration system
101a, 102a absorption refrigerator
E evaporator
E1 First evaporator
E2 Second evaporator
A absorber
A1 First absorber
A2 Second absorber
G regenerator
G1 First regenerator
G2 Second regenerator
C condenser
C1 First condenser
C2 Second condenser

Claims

A first generator for heating and concentrating the absorption liquid with a heating medium;
A first condenser for cooling and condensing the refrigerant vapor generated by the first generator with a first cooling medium;
A second generator for heating the absorption liquid concentrated in the first generator with the heating medium to further concentrate the absorption liquid;
A second condenser for cooling and condensing the refrigerant vapor generated by the second generator with the first cooling medium;
The heating medium is flowed in series to the second generator and the first generator in this order, and the first cooling medium is supplied to the first condenser and the second condenser. Configured to flow in series in order;
Absorption refrigerator.

A first evaporator that receives the refrigerant condensed in the first condenser and the refrigerant condensed in the second condenser, evaporates the refrigerant, and cools a cooling medium;
A second evaporator that receives the refrigerant condensed in the first condenser and the refrigerant condensed in the second condenser, evaporates the refrigerant, and cools the cooling medium;
A first absorbing means for receiving the concentrated absorbent in the second generator and absorbing the refrigerant evaporated in the first evaporator with the absorbent while cooling the absorbent with a second cooling medium; Vessel and;
A second absorbing means for absorbing the refrigerant absorbed by the first absorber and absorbing the refrigerant evaporated by the second evaporator with the absorbing liquid while cooling the absorbent with the second cooling medium; And an absorber of
The cooling medium is configured to flow through the second evaporator and the first evaporator in series in this order;
The absorption refrigerator according to claim 1.

An absorption refrigerator according to claim 1 or claim 2;
A heating source for supplying the heating medium;
Absorption refrigeration system.

The absorption refrigeration system according to claim 3, wherein the heating source is a fuel cell.