JP3883894B2

JP3883894B2 - Absorption refrigerator

Info

Publication number: JP3883894B2
Application number: JP2002092091A
Authority: JP
Inventors: 雅裕古川; 数恭伊良皆; 志奥山崎; 泰司鎌田
Original assignee: Sanyo Electric Co Ltd
Current assignee: Sanyo Electric Co Ltd
Priority date: 2002-03-28
Filing date: 2002-03-28
Publication date: 2007-02-21
Anticipated expiration: 2022-03-28
Also published as: CN1448671A; JP2003287314A; KR100512827B1; CN1215299C; KR20030078703A

Description

【０００１】
【発明の属する技術分野】
本発明は、吸収式冷凍機に関するものである。
【０００２】
【従来の技術】
図５に示したように、高温再生器１の稀吸収液を加熱沸騰させるガスバーナ２から排出される排ガスを、吸収液管１１の高温熱交換器１０と高温再生器１との間に設けた第１の排ガス熱回収器２３と、低温熱交換器９と高温熱交換器１０との間に設けた第２の排ガス熱回収器２４とに順次送り、吸収器７から高温再生器に１に搬送する稀吸収液の温度を上げ、ガスバーナ２による必要加熱量を減らし、燃料消費量を削減するように工夫した吸収式冷凍機が周知である。
【０００３】
すなわち、上記構成の吸収式冷凍機においては、吸収器７から吐出した約４０℃（定格運転時、以下同じ）の稀吸収液は低温熱交換器９・第２の排ガス熱回収器２４・高温熱交換器１０・第１の排ガス熱交換器２３それぞれで加熱され、１４０℃前後に上昇して高温再生器１に流入するので、ガスバーナ２で消費する燃料が節約できる。
【０００４】
なお、ガスバーナ２から出る排ガスの温度と吸収器７から供給される稀吸収液の温度が共に低くいときには、流量制御弁２５の開度を大きくして吸収液管（迂回吸収液管）１１Ｂに流れる稀吸収液の量を増加し、第２の排ガス熱回収器２４における排ガスからの熱回収を減少させて排ガス温度の著しい低下を防止し、排ガスに含まれる水蒸気の凝縮・結露を防止する構成となっている。
【０００５】
しかし、上記従来の吸収式冷凍機においては、流量制御弁２５が第２の排ガス熱回収器２４を迂回する吸収液管（迂回吸収液管）１１Ｂに設けられていたため、流量制御弁２５を全開にしても吸収液管１１Ａを通って第２の排ガス熱回収器２４に流れる稀吸収液の量は少なからずあった。
【０００６】
【発明が解決しようとする課題】
そのため、運転開始時など排ガス、稀吸収液の温度が共に低くいときには、流量制御弁を全開にしても排ガスの温度が低下し過ぎ、排ガスに含まれる水蒸気が凝縮・結露し、熱交換器や排気管を腐食することがあったので、そのような不都合が生じることのない構成の吸収式冷凍機を提供する必要があった。
【０００７】
【課題を解決するための手段】
本発明は上記従来技術の課題を解決するため、燃焼装置で加熱沸騰させて冷媒を蒸発分離し、稀吸収液から冷媒蒸気と中間吸収液を得る高温再生器と、この高温再生器で生成して供給される中間吸収液を高温再生器で生成した冷媒蒸気で加熱してさらに冷媒を蒸発分離し、中間吸収液から冷媒蒸気と濃吸収液を得る低温再生器と、この低温再生器で中間吸収液を加熱して凝縮した冷媒液が供給されると共に、低温再生器で生成して供給される冷媒蒸気を冷却して冷媒液を得る凝縮器と、この凝縮器から供給された冷媒液が伝熱管の上に散布され、伝熱管内を流れる流体から熱を奪って冷媒が蒸発する蒸発器と、この蒸発器で生成して供給される冷媒蒸気を低温再生器から冷媒蒸気を分離して供給される濃吸収液に吸収させて稀吸収液にし、高温再生器に供給する吸収器と、この吸収器に出入する稀吸収液と濃吸収液とが熱交換する低温熱交換器と、高温再生器に出入する中間吸収液と稀吸収液とが熱交換する高温熱交換器とを備えた吸収式冷凍機において、
燃焼装置から排出される排ガスと高温熱交換器を通過した稀吸収液とが熱交換する第１の排ガス熱回収器と、この第１の排ガス熱回収器を通過した排ガスと、低温熱交換器を通過し、高温熱交換器に入る前の稀吸収液とが熱交換する第２の排ガス熱回収器と、第２の排ガス熱回収器を通過する吸収液管の第２の排ガス熱回収器より上流側に位置する流量制御弁と、低温再生器を経由して凝縮器に向かって流れる冷媒と低温熱交換器を迂回して流れる稀吸収液とが熱交換する冷媒熱回収器と、を設けるようにした吸収式冷凍機を提供するものである。
【０００９】
【発明の実施の形態】
以下、本発明の実施形態を、水を冷媒とし、臭化リチウム（ＬｉＢｒ）水溶液を吸収液とした吸収式冷凍機を例に挙げて説明する。
【００１０】
〔本発明の第１の参考形態〕
本発明の第１の参考形態を、図１に基づいて説明する。図中１は、例えば都市ガスを燃料とするガスバーナ２の火力により吸収液を加熱して冷媒を蒸発分離するように構成された高温再生器、３は低温再生器、４は凝縮器、５は低温再生器３と凝縮器４が収納されている高温胴、６は蒸発器、７は吸収器、８は蒸発器６と吸収器７が収納されている低温胴、９は低温熱交換器、１０は高温熱交換器、１１〜１３は吸収液管、１４は吸収液ポンプ、１５〜１８は冷媒管、１９は冷媒ポンプ、２０は冷水管、２１は冷却水管、２２はガスバーナ２から出る排ガスが通る排気管、２３は第１の排ガス熱回収器、２４は第２の排ガス熱回収器、２５は流量制御弁、２６は排気管２２の下流部分を流れている排ガスの温度を検出する温度センサ、２７は温度センサ２６が所定の温度、例えば１００℃を検出し続けるように流量制御弁２５の開度を制御するための制御器である。
【００１１】
上記構成の吸収式冷凍機においては、ガスバーナ２で都市ガスを燃焼して高温再生器１で稀吸収液を加熱沸騰させると、稀吸収液から蒸発分離した冷媒蒸気と、冷媒蒸気を分離して吸収液の濃度が高くなった中間吸収液とが得られる。
【００１２】
高温再生器１で生成された高温の冷媒蒸気は、冷媒管１５を通って低温再生器３に入り、高温再生器１で生成され吸収液管１１により高温熱交換器１０を経由して低温再生器３に入った中間吸収液を加熱して放熱凝縮し、凝縮器４に入る。
【００１３】
また、低温再生器３で加熱されて中間吸収液から蒸発分離した冷媒は凝縮器４へ入り、冷却水管２１内を流れる水と熱交換して凝縮液化し、冷媒管１６から凝縮して供給される冷媒と一緒になって冷媒管１７を通って蒸発器６に入る。
【００１４】
蒸発器６に入って冷媒液溜りに溜まった冷媒液は、冷水管２０に接続された伝熱管２０Ａの上に冷媒ポンプ１９によって散布され、冷水管２０を介して供給される水と熱交換して蒸発し、伝熱管２０Ａの内部を流れる水を冷却する。
【００１５】
蒸発器６で蒸発した冷媒は吸収器７に入り、低温再生器３で加熱されて冷媒を蒸発分離し、吸収液濃度が一層高まった吸収液、すなわち吸収液管１３により低温熱交換器９を経由して供給され、上方から散布される濃吸収液に吸収される。
【００１６】
吸収器７で冷媒を吸収して濃度の薄くなった吸収液、すなわち稀吸収液は吸収液ポンプ１４の運転により、低温熱交換器９・第２の排ガス熱回収器２４（一部は吸収液管（迂回吸収液管）１１Ｂに流れて迂回する）・高温熱交換器１０・第１の排ガス熱回収器２３それぞれで加熱され、高温再生器１へ吸収液管１１から送られる。
【００１７】
上記のように吸収式冷凍機の運転が行われると、蒸発器６の内部に配管された伝熱管２０Ａにおいて冷媒の気化熱によって冷却された冷水が、冷水管２０を介して図示しない空調負荷に循環供給できるので、冷房などの冷却運転が行える。
【００１８】
上記構成の吸収式冷凍機においては、前記図５に示した従来の吸収式冷凍機と同様、吸収液ポンプ１４により高温再生器１に搬送される吸収器７の約４０℃の稀吸収液は、低温熱交換器９・第２の排ガス熱回収器２４（一部の稀吸収液は迂回する）・高温熱交換器１０・第１の排ガス熱回収器２３それぞれにおいて加熱され、１４０℃前後にまで温度が上昇して高温再生器１に供給されるので、第１の排ガス熱回収器２３・第２の排ガス熱回収器２４を備えない吸収式冷凍機よりガスバーナ２で消費する燃料を削減することができる。
【００１９】
すなわち、制御器２７により、温度センサ２６が所定の１００℃より高い温度を検出しているときには流量制御弁２５の開度を大きくし、吸収器７から高温再生器１に送っている稀吸収液のより多くを吸収液管１１Ａを経由して第２の排ガス熱回収器２４に供給、排ガスが保有する熱の回収が促進される。
【００２０】
しかも、上記の吸収式冷凍機においては、温度センサ２６が１００℃より低い温度を検出しているときには、稀吸収液の全量が第２の排ガス熱回収器２４を迂回して吸収液管（迂回吸収液管）１１Ｂに流れるまで、流量制御弁２５を最大全閉まで絞って排ガスから回収する熱量を最大ゼロまで抑えることが可能であるので、排ガス、稀吸収液の温度が共に低い起動時や部分負荷運転時においても、ガスバーナ２から排出され、排気管２２内を流れる排ガスの温度は露点温度（都市ガス、すなわち天然ガスを燃料としたときの燃焼排ガスの露点温度は６０〜７０℃）より高い１００℃に維持され、排ガスに含まれる水蒸気が凝縮してドレン水が発生することがないし、ドレン水による腐食問題を引き起こすこともない。
【００２１】
〔本発明の実施形態〕
本発明の実施形態を、図２に基づいて説明する。この本発明の実施形態の吸収式冷凍機においては、前記図１に示した第１の参考形態の吸収式冷凍機の配管構成に加えて、冷媒熱回収器２８が設けられている。
【００２２】
そして、その冷媒熱回収器２８には、低温再生器３から凝縮器４に向かう冷媒、すなわち低温再生器３で中間吸収液を加熱し、冷媒を蒸発分離して凝縮した冷媒と、吸収器７から吸収液ポンプ１４により高温再生器１に搬送されている稀吸収液の一部、すなわち低温熱交換器９を迂回して設けた吸収液管（稀吸収液分岐管）１１Ｃを流れる稀吸収液とを供給して熱交換させ、冷媒液が保有する余熱を高温再生器１に搬送している稀吸収液により回収するように構成されている。その他の配管構成は、前記第１の参考形態の吸収式冷凍機と同じである。
【００２３】
この本発明の実施形態の吸収式冷凍機においては、吸収液ポンプ１４の運転により吸収器７から高温再生器１に戻される稀吸収液の一部は吸収液管１１に介在する低温熱交換器９を経由し、残部は吸収液管（稀吸収液分岐管）１１Ｃに介在する冷媒熱回収器２８を経由し、それぞれの熱交換器において加熱される。
【００２４】
また、第２の排ガス熱回収器２４を経由してガスバーナ２から出る排ガスにより加熱される稀吸収液の量は、吸収液管１１Ａに介在する流量制御弁２５により制御され、高温熱交換器１０と第１の排ガス熱回収器２３には吸収器７から高温再生器１に戻す稀吸収液の全量が流れてそれぞれで加熱される。
【００２５】
すなわち、吸収器７から吸収液管１１に吐出した約４０℃の稀吸収液の一部は、低温再生器３から吸収液管１３に吐出して吸収器７に流れている約９０℃の濃吸収液と低温熱交換器９で熱交換して約８５℃まで温度上昇し、残部は低温再生器３で凝縮して凝縮器４に流れている冷媒管１６の約９５℃の冷媒液と冷媒熱回収器２８で熱交換して７０℃まで温度上昇し、それらは合流し、例えば８０℃前後の稀吸収液となって吸収液管１１を高温再生器１に向かって流れる。
【００２６】
そして、第２の排ガス熱回収器２４に流入する稀吸収液の流量は、前記図１に示した第１の参考形態の吸収式冷凍機と同様に制御器２７により制御される。すなわち、制御器２７は流量制御弁２５の開度を温度センサ２６が所定の１００℃より高い温度を検出しているときには大きくし、稀吸収液のより多くを第２の排ガス熱回収器２４に供給して排ガスが保有する熱の回収を促進する。
【００２７】
一方、温度センサ２６が１００℃より低い温度を検出しているときには、稀吸収液の全量が第２の排ガス熱回収器２４を迂回して吸収液管（迂回吸収液管）１１Ｂに流れるまで、流量制御弁２５を最大全閉まで絞って排ガスから回収する熱量を最大ゼロまで抑えることが可能であるので、排ガス、稀吸収液の温度が共に低い起動時や部分負荷運転時においても、ガスバーナ２から排出され、排気管２２内を流れる排ガスの温度は露点温度より高い１００℃に維持され、排ガスに含まれる水蒸気が凝縮してドレン水が発生することがないし、ドレン水による腐食問題を引き起こすこともない。
【００２８】
そして、第２の排ガス熱回収器２４を経由して加熱された稀吸収液と、第２の排ガス熱回収器２４を経由せず、したがって加熱されなかった稀吸収液とは合流して高温熱交換器１０と第１の排ガス熱回収器２３とを経由し、高温再生器１から低温再生器３に吸収液管１２を介して流れている中間吸収液と、ガスバーナ２から排出された約２００℃の排ガスと熱交換して１４０℃程度の稀吸収液となって高温再生器１に流入するので、ガスバーナ２で消費する燃料が節約できる。
【００２９】
また、低温再生器３で凝縮して冷媒管１６を通って凝縮器４に流入する冷媒液は、前記したように冷媒熱回収器２８で約４０℃の稀吸収液と熱交換してこれを加熱し、冷媒液自身は約４５℃（従来は約９５℃）に冷却されて流入するので、冷却水管２１の内部を流れる冷却水に放熱する熱量が減少する。そのため、高温再生器１における所用入熱量が削減でき、熱効率は前記図１に示した第１の参考形態の吸収式冷凍機よりさらに改善される。
【００３０】
〔本発明の第２の参考形態〕
本発明の第２の参考形態を、図３に基づいて説明する。この第２の参考形態の吸収式冷凍機においては、前記図１に示した第１の参考形態の吸収式冷凍機が備えていた吸収液管（迂回吸収液管）１１Ｂに代えて第２の排ガス熱回収器２４を迂回する排気管（迂回排気管）２２Ｂを設け、さらに流量制御弁２５に代えて第２の排ガス熱回収器２４を経由している排気管２２Ａと排気管（迂回排気管）２２Ｂとの分岐部に切替弁２５Ａを設けるようにしたものである。
【００３１】
なお、温度センサ２６は、排気管２２Ａと排気管（迂回排気管）２２Ｂとの分岐部より上流側の排気管２２に設置されている。その他の配管構成は前記第１の参考形態の吸収式冷凍機と同じである。
【００３２】
そして、この第２の参考形態の吸収式冷凍機においては、温度センサ２６が所定の温度、例えば１５０℃より高い温度を検出しているときには、ガスバーナ２から出る排ガスの全量を第２の排ガス熱回収器２４に流して排ガスからの熱回収を行い、温度センサ２６が所定の１５０℃より低い温度を検出しているときには排ガスの全量を第２の排ガス熱回収器２４を迂回して流し、排ガス温度の著しい低下を防止するように、制御器２７が切替弁２５Ａの切替制御を行う。
【００３３】
したがって、この第２の参考形態の吸収式冷凍機においても、ガスバーナ２で消費する燃料が削減でき、熱効率が改善される。また、稀吸収液と熱交換して第２の排ガス熱回収器２４から排出される排ガスの温度は所要の温度、例えば１００℃を下回ることがない。そのため、排ガスに含まれる水蒸気が凝縮してドレン水が発生することがないし、ドレン水による腐食問題を引き起こすこともない。
【００３４】
〔本発明の第３の参考形態〕
本発明の第３の参考形態を、図４に基づいて説明する。この第３の参考形態の吸収式冷凍機においても、前記図２に示した本発明の実施形態の吸収式冷凍機が備えていた吸収液管（迂回吸収液管）１１Ｂに代えて第２の排ガス熱回収器２４を迂回する排気管（迂回排気管）２２Ｂを設け、さらに流量制御弁２５に代えて第２の排ガス熱回収器２４を経由している排気管２２Ａと排気管（迂回排気管）２２Ｂとの分岐部に切替弁２５Ａを設けるようにしたものである。
【００３５】
なお、温度センサ２６は、前記第２の参考形態の吸収式冷凍機と同様に、排気管２２Ａと排気管（迂回排気管）２２Ｂとの分岐部より上流側の排気管２２に設置され、その他の配管構成は前記本発明の実施形態の吸収式冷凍機と同じである。
【００３６】
そして、この第３の参考形態の吸収式冷凍機においても、前記第２の参考形態の吸収式冷凍機と同様に、温度センサ２６が所定の温度、例えば１５０℃より高い温度を検出しているときには、ガスバーナ２から出る排ガスの全量を第２の排ガス熱回収器２４に流して排ガスからの熱回収を行い、温度センサ２６が所定の１５０℃より低い温度を検出しているときには排ガスの全量を第２の排ガス熱回収器２４を迂回して流し、排ガス温度の著しい低下を防止するように、切替弁２５Ａの切替が制御器２７により制御される。
【００３７】
したがって、この第３の参考形態の吸収式冷凍機においても、ガスバーナ２で消費する燃料が削減でき、熱効率が改善される。また、稀吸収液と熱交換して第２の排ガス熱回収器２４から排出される排ガスの温度は所要の温度、例えば１００℃を下回ることがない。そのため、排ガスに含まれる水蒸気が凝縮してドレン水が発生することがないし、ドレン水による腐食問題を引き起こすこともない。
【００３８】
なお、本発明は上記実施形態に限定されるものではないので、特許請求の範囲に記載の趣旨から逸脱しない範囲で各種の変形実施が可能である。
【００３９】
例えば、流量制御弁２５に代えて廉価な開閉弁を設置し、その開閉を温度センサ２６が検出する排ガス温度が所定の温度を下回らないように制御器２７により単に制御する構成とすることもできる。
【００４０】
また、流量制御弁２５に代えて、切替弁または分配率制御が可能な流量制御弁を吸収液管１１Ａの端部、すなわち吸収液管（迂回吸収液管）１１Ｂとの分岐部またはその合流部に設けるように構成とすることもできる。
【００４１】
また、図３、図４に示した第２、第３の参考形態の吸収式冷凍機においては、排気管２２Ａの排気管（迂回排気管）２２Ｂとの合流部の上流側にも排ガス温度を検出するための第２の温度センサを設置し、その第２の温度センサが所定の１００℃より低い温度を検出したときにはガスバーナ２から出る排ガスの全量を第２の排ガス熱回収器２４を迂回して流し、第２の温度センサが所定の１００℃より低い温度を検出したときに検出していた温度より所定温度、例えば５℃だけ高い温度を温度センサ２６が検出したときに、ガスバーナ２から出る排ガスの全量が第２の排ガス熱回収器２４に流れるように、制御器２７が切替弁２５Ａを切替える構成とすることも可能である。
【００４２】
また、低温再生器３で加熱濃縮した濃吸収液を低温熱交換器９を経由して吸収器７に導く吸収液管１３には、図２、図４に破線で示したように吸収液管（迂回吸収液管）１３Ａと吸収液ポンプ２９とを設けることも可能である。
【００４３】
また、吸収式冷凍機は、上記のように冷房などの冷却運転を専用に行うものであっても良いし、高温再生器１で加熱生成した冷媒蒸気と、冷媒蒸気を蒸発分離した吸収液とが低温胴８に直接供給できるように配管接続し、冷却水管２１に冷却水を流すことなくガスバーナ２による稀吸収液の加熱を行い、蒸発器６の伝熱管２０Ａで例えば５５℃程度に加熱した水を冷水管（温水が循環する場合は温水管と呼ぶのが好ましい）２０を介して負荷に循環供給して暖房などの加熱運転も行えるようにしたものであってもよい。
【００４４】
また、冷媒熱回収器２８を備えた図２に示す本発明の実施形態と、図４に示す第３の参考形態の吸収式冷凍機においては、低温再生器３から供給される冷媒は冷媒熱回収器２８で稀吸収液に放熱し温度は十分低下するので、凝縮器４ではなく、蒸発器６に流入するように冷媒管１６を配管することも可能である。
【００４５】
また、蒸発器６で冷却などして空調負荷などに供給する流体としては、水などを上記実施形態のように相変化させないで供給するほか、潜熱を利用した熱搬送が可能なようにフロンなどを相変化させて供給するようにしても良い。
【００４６】
【発明の効果】
以上説明したように本発明によれば、排ガスが保有する熱を効率よく回収することが可能である。しかも、排ガス温度が低くなる起動時や部分負荷運転時においては排ガスからの熱回収を完全にゼロに抑えて排ガス温度の異常低下を防止することができるので、排ガスに含まれる水蒸気が凝縮してドレン水が発生することがないし、ドレン水による腐食問題を引き起こすこともない。
【図面の簡単な説明】
【図１】本発明の第１の参考形態を示す説明図である。
【図２】本発明の実施形態を示す説明図である。
【図３】本発明の第２の参考形態を示す説明図である。
【図４】本発明の第３の参考形態を示す説明図である。
【図５】従来技術を示す説明図である。
【符号の説明】
１高温再生器
２ガスバーナ
３低温再生器
４凝縮器
５高温胴
６蒸発器
７吸収器
８高温胴
９低温熱交換器
１０高温熱交換器
１１、１１Ａ、１２、１３吸収液管
１１Ｂ吸収液管（迂回吸収液管）
１１Ｃ吸収液管（稀吸収液分岐管）
１４吸収液ポンプ
１５〜１９冷媒管
１９冷媒ポンプ
２０冷水管
２１冷却水管
２２、２２Ａ排気管
２２Ｂ排気管（迂回排気管）
２３第１の排ガス熱回収器
２４第２の排ガス熱回収器
２５流量制御弁
２５Ａ切替弁
２６温度センサ
２７制御器
２８冷媒熱回収器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an absorption refrigerator.
[0002]
[Prior art]
As shown in FIG. 5, the exhaust gas discharged from the gas burner 2 for heating and boiling the rare absorbent in the high temperature regenerator 1 is provided between the high temperature heat exchanger 10 and the high temperature regenerator 1 in the absorption liquid pipe 11. Sequentially sent to the first exhaust gas heat recovery unit 23 and the second exhaust gas heat recovery unit 24 provided between the low temperature heat exchanger 9 and the high temperature heat exchanger 10, and from the absorber 7 to the high temperature regenerator 1 Absorption refrigerators that are devised to increase the temperature of the rare absorbent to be conveyed, reduce the required amount of heating by the gas burner 2, and reduce fuel consumption are well known.
[0003]
That is, in the absorption refrigerator having the above-described configuration, the rare absorbent discharged at about 40 ° C. (during rated operation, the same applies hereinafter) discharged from the absorber 7 is used in the low-temperature heat exchanger 9, the second exhaust gas heat recovery unit 24, and the high Heated by the hot heat exchanger 10 and the first exhaust gas heat exchanger 23 respectively, rises to around 140 ° C. and flows into the high temperature regenerator 1, so that the fuel consumed by the gas burner 2 can be saved.
[0004]
When the temperature of the exhaust gas exiting from the gas burner 2 and the temperature of the rare absorbent supplied from the absorber 7 are both low, the opening degree of the flow control valve 25 is increased and the absorption liquid pipe (bypass absorption liquid pipe) 11B is provided. A configuration in which the amount of the rare absorbing liquid that flows is increased, heat recovery from the exhaust gas in the second exhaust gas heat recovery unit 24 is reduced to prevent a significant decrease in exhaust gas temperature, and condensation / condensation of water vapor contained in the exhaust gas is prevented. It has become.
[0005]
However, in the above conventional absorption refrigerator, the flow control valve 25 is provided in the absorption liquid pipe (bypass absorption liquid pipe) 11B that bypasses the second exhaust gas heat recovery device 24, and therefore the flow control valve 25 is fully opened. Even so, the amount of the diluted absorbent flowing through the absorbent pipe 11A to the second exhaust gas heat recovery device 24 was not small.
[0006]
[Problems to be solved by the invention]
Therefore, when the temperature of the exhaust gas and the rare absorbent is both low, such as at the start of operation, the temperature of the exhaust gas will decrease too much even if the flow control valve is fully opened, and water vapor contained in the exhaust gas will condense and condense. Since the exhaust pipe may be corroded, it is necessary to provide an absorption refrigerator having a configuration in which such inconvenience does not occur.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems of the prior art, the present invention generates a refrigerant vapor and an intermediate absorption liquid from a rare absorption liquid by evaporating and separating the refrigerant by heating and boiling with a combustion apparatus, and the high temperature regenerator. The intermediate absorption liquid supplied in this way is heated with the refrigerant vapor generated in the high-temperature regenerator to further evaporate and separate the refrigerant, and obtain a refrigerant vapor and concentrated absorption liquid from the intermediate absorption liquid, and the low-temperature regenerator A refrigerant liquid condensed by heating the absorption liquid is supplied, a condenser that cools the refrigerant vapor generated and supplied by the low-temperature regenerator to obtain a refrigerant liquid, and a refrigerant liquid supplied from the condenser An evaporator that spreads on the heat transfer pipe and takes heat from the fluid flowing in the heat transfer pipe to evaporate the refrigerant, and separates the refrigerant vapor generated and supplied by the evaporator from the low temperature regenerator. Absorbed in the concentrated absorbent supplied to make it a rare absorbent. Heat exchange between the absorber supplied to the regenerator, the low-temperature heat exchanger that exchanges heat between the rare and concentrated absorbents that enter and exit the absorber, and the intermediate and rare absorbent that enters and exits the high-temperature regenerator In an absorption refrigerator equipped with a high temperature heat exchanger
A first exhaust gas heat recovery device that exchanges heat between the exhaust gas discharged from the combustion device and the rare absorbent that has passed through the high temperature heat exchanger, an exhaust gas that has passed through the first exhaust gas heat recovery device, and a low temperature heat exchanger The second exhaust gas heat recovery device that exchanges heat with the rare absorbent before passing through the high temperature heat exchanger and the second exhaust gas heat recovery device of the absorption liquid pipe that passes through the second exhaust gas heat recovery device A flow rate control valve located on the upstream side, and a refrigerant heat recovery unit that exchanges heat between the refrigerant flowing toward the condenser via the low-temperature regenerator and the rare absorbent flowing around the low-temperature heat exchanger. An absorption refrigerator that is provided is provided.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described by taking an absorption refrigerator using water as a refrigerant and a lithium bromide (LiBr) aqueous solution as an example.
[0010]
[ First Reference Embodiment of the Present Invention ]
A first reference embodiment of the present invention will be described with reference to FIG. In the figure, reference numeral 1 denotes a high-temperature regenerator configured to heat and absorb the refrigerant by heating power of a gas burner 2 using, for example, city gas as a fuel, 3 is a low-temperature regenerator, 4 is a condenser, A high temperature cylinder in which the low temperature regenerator 3 and the condenser 4 are accommodated, 6 is an evaporator, 7 is an absorber, 8 is a low temperature cylinder in which the evaporator 6 and the absorber 7 are accommodated, 9 is a low temperature heat exchanger, 10 is a high-temperature heat exchanger, 11 to 13 are absorption liquid pipes, 14 is an absorption liquid pump, 15 to 18 are refrigerant pipes, 19 is a refrigerant pump, 20 is a cold water pipe, 21 is a cooling water pipe, 22 is an exhaust gas from the gas burner 2 An exhaust pipe through which the exhaust gas passes, 23 is a first exhaust gas heat recovery unit, 24 is a second exhaust gas heat recovery unit, 25 is a flow control valve, and 26 is a temperature at which the temperature of the exhaust gas flowing in the downstream portion of the exhaust pipe 22 is detected. The sensor 27 detects that the temperature sensor 26 detects a predetermined temperature, for example, 100 ° C. A controller for controlling the opening of the flow control valve 25 as kicking.
[0011]
In the absorption refrigerator having the above-described configuration, when the city gas is burned by the gas burner 2 and the rare absorbent is heated and boiled by the high temperature regenerator 1, the refrigerant vapor evaporated and separated from the rare absorbent is separated from the refrigerant vapor. An intermediate absorption liquid having a high concentration of the absorption liquid is obtained.
[0012]
The high-temperature refrigerant vapor generated in the high-temperature regenerator 1 enters the low-temperature regenerator 3 through the refrigerant pipe 15, and is generated in the high-temperature regenerator 1 through the high-temperature heat exchanger 10 via the high-temperature heat exchanger 10. The intermediate absorption liquid that has entered the condenser 3 is heated and condensed by heat dissipation, and enters the condenser 4.
[0013]
Further, the refrigerant heated by the low-temperature regenerator 3 and evaporated and separated from the intermediate absorption liquid enters the condenser 4, exchanges heat with the water flowing in the cooling water pipe 21 to be condensed and liquefied, and is condensed and supplied from the refrigerant pipe 16. The refrigerant enters the evaporator 6 through the refrigerant pipe 17 together with the refrigerant.
[0014]
The refrigerant liquid that has entered the evaporator 6 and accumulated in the refrigerant liquid reservoir is sprayed by the refrigerant pump 19 on the heat transfer pipe 20 </ b> A connected to the cold water pipe 20, and exchanges heat with water supplied through the cold water pipe 20. The water flowing through the heat transfer tube 20A is cooled.
[0015]
The refrigerant evaporated by the evaporator 6 enters the absorber 7 and is heated by the low-temperature regenerator 3 to evaporate and separate the refrigerant. The absorption liquid having a higher absorption liquid concentration, that is, the absorption liquid pipe 13 causes the low-temperature heat exchanger 9 to pass through. It is supplied via and absorbed by the concentrated absorbent dispersed from above.
[0016]
The absorption liquid whose concentration has been reduced by absorbing the refrigerant in the absorber 7, that is, the rare absorption liquid, is operated by the operation of the absorption liquid pump 14, so that the low-temperature heat exchanger 9 and the second exhaust gas heat recovery device 24 (partly the absorption liquid). It is heated by the high-temperature heat exchanger 10 and the first exhaust gas heat recovery unit 23 and sent to the high-temperature regenerator 1 from the absorption liquid pipe 11.
[0017]
When the absorption refrigerator is operated as described above, the cold water cooled by the heat of vaporization of the refrigerant in the heat transfer pipe 20A piped inside the evaporator 6 becomes an air conditioning load (not shown) via the cold water pipe 20. Since it can be circulated, cooling operation such as cooling can be performed.
[0018]
In the absorption chiller having the above-described configuration, as in the conventional absorption chiller shown in FIG. 5, the rare absorption liquid at about 40 ° C. of the absorber 7 conveyed to the high-temperature regenerator 1 by the absorption liquid pump 14 is The low-temperature heat exchanger 9 and the second exhaust gas heat recovery unit 24 (a part of the rare absorption liquid bypasses), the high-temperature heat exchanger 10 and the first exhaust gas heat recovery unit 23 are heated to about 140 ° C. Since the temperature rises to be supplied to the high temperature regenerator 1, the fuel consumed by the gas burner 2 is reduced from the absorption chiller that does not include the first exhaust gas heat recovery unit 23 and the second exhaust gas heat recovery unit 24. be able to.
[0019]
That is, the controller 27 increases the opening of the flow control valve 25 when the temperature sensor 26 detects a temperature higher than the predetermined 100 ° C., and the rare absorbent is sent from the absorber 7 to the high-temperature regenerator 1. Is supplied to the second exhaust gas heat recovery unit 24 via the absorption liquid pipe 11A, and the recovery of the heat held by the exhaust gas is promoted.
[0020]
In addition, in the absorption refrigerator described above, when the temperature sensor 26 detects a temperature lower than 100 ° C., the entire amount of the rare absorbing liquid bypasses the second exhaust gas heat recovery device 24 and the absorbing liquid pipe (bypassing). The flow rate control valve 25 can be throttled to the maximum fully closed position until it flows to the absorption liquid pipe) 11B, and the amount of heat recovered from the exhaust gas can be suppressed to a maximum of zero. Even during partial load operation, the temperature of the exhaust gas discharged from the gas burner 2 and flowing in the exhaust pipe 22 is from the dew point temperature (the dew point temperature of the combustion exhaust gas when using city gas, that is, natural gas as the fuel is 60 to 70 ° C.). It is maintained at a high temperature of 100 ° C., water vapor contained in the exhaust gas is not condensed and drain water is not generated, and corrosion problems due to drain water are not caused.
[0021]
Embodiment of the present invention
An embodiment of the present invention will be described with reference to FIG. In the absorption refrigerator of the embodiment of the present invention , a refrigerant heat recovery device 28 is provided in addition to the piping configuration of the absorption refrigerator of the first reference embodiment shown in FIG.
[0022]
The refrigerant heat recovery unit 28 includes a refrigerant from the low-temperature regenerator 3 toward the condenser 4, that is, a refrigerant obtained by evaporating and separating the refrigerant by heating the intermediate absorption liquid in the low-temperature regenerator 3, and the absorber 7 From the absorption liquid pump 14 to the high-temperature regenerator 1, that is, the rare absorption liquid flowing in the absorption liquid pipe (rare absorption liquid branch pipe) 11 C provided around the low-temperature heat exchanger 9. And the heat exchange is performed, and the remaining heat held by the refrigerant liquid is recovered by the rare absorbing liquid conveyed to the high-temperature regenerator 1. Other piping configurations are the same as those of the absorption refrigerator of the first reference embodiment .
[0023]
In the absorption refrigerator according to the embodiment of the present invention, a part of the rare absorbing liquid returned from the absorber 7 to the high-temperature regenerator 1 by the operation of the absorbing liquid pump 14 is a low temperature heat exchanger interposed in the absorbing liquid pipe 11. 9 and the remainder is heated in each heat exchanger via the refrigerant heat recovery device 28 interposed in the absorption liquid pipe (rare absorption liquid branch pipe) 11C.
[0024]
Further, the amount of the rare absorbent heated by the exhaust gas exiting from the gas burner 2 via the second exhaust gas heat recovery device 24 is controlled by the flow rate control valve 25 interposed in the absorption liquid pipe 11A, and the high temperature heat exchanger 10 The first exhaust gas heat recovery unit 23 is supplied with the entire amount of the diluted absorbent returned from the absorber 7 to the high-temperature regenerator 1 and is heated by each.
[0025]
That is, a part of the about 40 ° C. rare absorption liquid discharged from the absorber 7 to the absorption liquid pipe 11 is discharged to the absorption liquid pipe 13 from the low-temperature regenerator 3 and flows into the absorption liquid 7 at a concentration of about 90 ° C. Heat exchange is performed with the absorbing liquid in the low-temperature heat exchanger 9 and the temperature rises to about 85 ° C., and the remainder is condensed in the low-temperature regenerator 3 and flows into the condenser 4 at about 95 ° C. Heat exchange is performed by the heat recovery unit 28 and the temperature rises to 70 ° C., and they merge together to form, for example, a rare absorption liquid at around 80 ° C. and flow through the absorption liquid pipe 11 toward the high-temperature regenerator 1.
[0026]
Then, the flow rate of the rare absorbing liquid flowing into the second exhaust gas heat recovery unit 24 is controlled by the controller 27 in the same manner as in the absorption refrigerator of the first reference embodiment shown in FIG. That is, the controller 27 increases the opening degree of the flow control valve 25 when the temperature sensor 26 detects a temperature higher than the predetermined 100 ° C., and more of the rare absorbent is supplied to the second exhaust gas heat recovery unit 24. Supply and promote recovery of heat held in exhaust gas.
[0027]
On the other hand, when the temperature sensor 26 detects a temperature lower than 100 ° C., until the entire amount of the rare absorbent flows around the second exhaust gas heat recovery device 24 and flows into the absorbent liquid pipe (detour absorbent liquid pipe) 11B, Since the flow control valve 25 can be throttled to the maximum fully closed to reduce the amount of heat recovered from the exhaust gas to a maximum of zero, the gas burner 2 can be used even during start-up or partial load operation where the temperature of the exhaust gas and the rare absorbent is both low. The temperature of the exhaust gas discharged from the exhaust gas and flowing in the exhaust pipe 22 is maintained at 100 ° C., which is higher than the dew point temperature, and the water vapor contained in the exhaust gas does not condense and does not generate drain water, causing corrosion problems due to drain water. Nor.
[0028]
Then, the rare absorbent that has been heated via the second exhaust gas heat recovery device 24 and the rare absorbent that has not passed through the second exhaust gas heat recovery device 24 and thus has not been heated are joined together to generate high-temperature heat. The intermediate absorption liquid flowing from the high-temperature regenerator 1 to the low-temperature regenerator 3 through the absorption liquid pipe 12 via the exchanger 10 and the first exhaust gas heat recovery unit 23, and about 200 discharged from the gas burner 2 Heat exchange with the exhaust gas at ℃ becomes a rare absorbent at about 140 ℃ and flows into the high-temperature regenerator 1, so that the fuel consumed by the gas burner 2 can be saved.
[0029]
Further, the refrigerant liquid condensed in the low temperature regenerator 3 and flowing into the condenser 4 through the refrigerant pipe 16 is exchanged with the rare absorption liquid at about 40 ° C. in the refrigerant heat recovery unit 28 as described above. Since the refrigerant liquid itself is heated and cooled to about 45 ° C. (conventionally about 95 ° C.), the amount of heat radiated to the cooling water flowing inside the cooling water pipe 21 is reduced. Therefore, the required heat input in the high temperature regenerator 1 can be reduced, and the thermal efficiency is further improved as compared with the absorption refrigerator of the first reference embodiment shown in FIG.
[0030]
[ Second embodiment of the present invention ]
A second reference embodiment of the present invention will be described with reference to FIG. In the absorption refrigerating machine of the second reference form, a second refill is provided instead of the absorption liquid pipe (bypass absorption liquid pipe) 11B provided in the absorption refrigerating machine of the first reference form shown in FIG. An exhaust pipe (a bypass exhaust pipe) 22B that bypasses the exhaust gas heat recovery device 24 is provided, and an exhaust pipe 22A and an exhaust pipe (a bypass exhaust pipe) that pass through the second exhaust gas heat recovery device 24 instead of the flow rate control valve 25. ) A switching valve 25A is provided at a branch portion with 22B.
[0031]
The temperature sensor 26 is installed in the exhaust pipe 22 upstream of the branch portion between the exhaust pipe 22A and the exhaust pipe (detour exhaust pipe) 22B. Other piping configurations are the same as those of the absorption refrigerator of the first reference embodiment .
[0032]
In the absorption refrigerator of the second reference embodiment , when the temperature sensor 26 detects a temperature higher than a predetermined temperature, for example, 150 ° C., the total amount of exhaust gas emitted from the gas burner 2 is converted to the second exhaust gas heat. When the temperature sensor 26 detects a temperature lower than a predetermined 150 ° C., the entire amount of the exhaust gas is caused to flow around the second exhaust gas heat recovery device 24 to be exhausted. The controller 27 performs switching control of the switching valve 25A so as to prevent a significant decrease in temperature.
[0033]
Therefore, also in the absorption refrigerator of the second reference embodiment , the fuel consumed by the gas burner 2 can be reduced, and the thermal efficiency is improved. Further, the temperature of the exhaust gas that is exchanged with the rare absorbent and discharged from the second exhaust gas heat recovery device 24 does not fall below a required temperature, for example, 100 ° C. Therefore, the water vapor contained in the exhaust gas is not condensed and drain water is not generated, and the corrosion problem due to the drain water is not caused.
[0034]
[ Third embodiment of the present invention ]
A third embodiment of the present invention will be described with reference to FIG. Also in the absorption chiller of the third reference embodiment, the second embodiment replaces the absorption liquid pipe (bypass absorption liquid pipe) 11B provided in the absorption chiller of the embodiment of the present invention shown in FIG. An exhaust pipe (a bypass exhaust pipe) 22B that bypasses the exhaust gas heat recovery device 24 is provided, and an exhaust pipe 22A and an exhaust pipe (a bypass exhaust pipe) that pass through the second exhaust gas heat recovery device 24 instead of the flow rate control valve 25. ) A switching valve 25A is provided at a branch portion with 22B.
[0035]
The temperature sensor 26 is installed in the exhaust pipe 22 upstream of the branch portion of the exhaust pipe 22A and the exhaust pipe (detour exhaust pipe) 22B, as in the absorption refrigerator of the second reference embodiment. The piping configuration is the same as that of the absorption refrigerator according to the embodiment of the present invention .
[0036]
And also in the absorption refrigerator of this 3rd reference form , the temperature sensor 26 has detected temperature higher than predetermined | prescribed temperature, for example, 150 degreeC similarly to the absorption refrigerator of the said 2nd reference form . Sometimes, the entire amount of the exhaust gas emitted from the gas burner 2 is flowed to the second exhaust gas heat recovery unit 24 to recover the heat from the exhaust gas. When the temperature sensor 26 detects a temperature lower than a predetermined 150 ° C., the total amount of the exhaust gas is Switching of the switching valve 25A is controlled by the controller 27 so as to bypass the second exhaust gas heat recovery device 24 and prevent a significant decrease in exhaust gas temperature.
[0037]
Therefore, also in the absorption refrigerator of the third reference embodiment , the fuel consumed by the gas burner 2 can be reduced, and the thermal efficiency is improved. Further, the temperature of the exhaust gas that is exchanged with the rare absorbent and discharged from the second exhaust gas heat recovery device 24 does not fall below a required temperature, for example, 100 ° C. Therefore, the water vapor contained in the exhaust gas is not condensed and drain water is not generated, and the corrosion problem due to the drain water is not caused.
[0038]
In addition, since this invention is not limited to the said embodiment, various deformation | transformation implementation is possible in the range which does not deviate from the meaning as described in a claim.
[0039]
For example, an inexpensive on-off valve may be installed in place of the flow control valve 25, and the open / close valve may be simply controlled by the controller 27 so that the exhaust gas temperature detected by the temperature sensor 26 does not fall below a predetermined temperature. .
[0040]
Further, instead of the flow rate control valve 25, a switching valve or a flow rate control valve capable of controlling the distribution rate is provided at the end of the absorption liquid pipe 11A, that is, a branching part with the absorption liquid pipe (bypass absorption liquid pipe) 11B or its junction. It can also be set as it provides in.
[0041]
In the absorption refrigerators of the second and third reference embodiments shown in FIGS. 3 and 4, the exhaust gas temperature is also increased upstream of the junction of the exhaust pipe 22A and the exhaust pipe (detour exhaust pipe) 22B. A second temperature sensor is installed for detection, and when the second temperature sensor detects a temperature lower than a predetermined 100 ° C., the second exhaust gas heat recovery device 24 bypasses the entire amount of exhaust gas emitted from the gas burner 2. When the temperature sensor 26 detects a temperature higher than a temperature detected when the second temperature sensor detects a temperature lower than a predetermined temperature of 100 ° C., for example, 5 ° C., the gas sensor 2 exits the gas burner 2. It is also possible to adopt a configuration in which the controller 27 switches the switching valve 25 </ b> A so that the entire amount of exhaust gas flows to the second exhaust gas heat recovery device 24.
[0042]
Further, as shown in FIG. 2 and FIG. 4, the absorption liquid pipe is provided in the absorption liquid pipe 13 that leads the concentrated absorption liquid heated and concentrated in the low temperature regenerator 3 to the absorber 7 through the low temperature heat exchanger 9. It is also possible to provide the (detour absorption liquid pipe) 13A and the absorption liquid pump 29.
[0043]
In addition, the absorption refrigerator may be a dedicated one that performs cooling operations such as cooling as described above, and the refrigerant vapor generated by heating in the high-temperature regenerator 1, the absorption liquid obtained by evaporating and separating the refrigerant vapor, and Is connected to the low-temperature barrel 8 directly, and the diluted absorbent is heated by the gas burner 2 without flowing cooling water through the cooling water pipe 21, and is heated to, for example, about 55 ° C. by the heat transfer pipe 20 A of the evaporator 6. The water may be circulated and supplied to a load through a cold water pipe (preferably referred to as a hot water pipe when hot water circulates) 20 so that heating operation such as heating can be performed.
[0044]
In the embodiment of the present invention shown in FIG. 2 provided with the refrigerant heat recovery device 28 and the absorption refrigerating machine of the third reference embodiment shown in FIG. 4, the refrigerant supplied from the low temperature regenerator 3 is refrigerant heat. Since the heat is released to the rare absorbent by the recovery device 28 and the temperature is sufficiently lowered, the refrigerant pipe 16 can be piped so as to flow into the evaporator 6 instead of the condenser 4.
[0045]
In addition, as a fluid to be cooled by the evaporator 6 and supplied to an air conditioning load or the like, water or the like is supplied without changing the phase as in the above embodiment, and in addition, chlorofluorocarbon is used so that heat transfer using latent heat is possible. The phase may be supplied by changing the phase.
[0046]
【The invention's effect】
As described above, according to the present invention, it is possible to efficiently recover the heat held by the exhaust gas. In addition, during start-up and partial load operation when the exhaust gas temperature is low, heat recovery from the exhaust gas can be suppressed to zero to prevent an abnormal decrease in the exhaust gas temperature, so that the water vapor contained in the exhaust gas is condensed. Drain water is not generated and does not cause corrosion problems due to drain water.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a first reference embodiment of the present invention.
FIG. 2 is an explanatory diagram showing an embodiment of the present invention .
FIG. 3 is an explanatory view showing a second reference embodiment of the present invention.
FIG. 4 is an explanatory diagram showing a third reference embodiment of the present invention.
FIG. 5 is an explanatory diagram showing a conventional technique.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 High temperature regenerator 2 Gas burner 3 Low temperature regenerator 4 Condenser 5 High temperature cylinder 6 Evaporator 7 Absorber 8 High temperature cylinder 9 Low temperature heat exchanger 10 High temperature heat exchanger 11, 11A, 12, 13 Absorption liquid pipe 11B Absorption liquid pipe ( Detour absorption pipe)
11C Absorption liquid pipe (Diluted Absorption liquid branch pipe)
14 Absorption liquid pump 15-19 Refrigerant pipe 19 Refrigerant pump 20 Chilled water pipe 21 Cooling water pipe 22, 22A Exhaust pipe 22B Exhaust pipe (bypass exhaust pipe)
23 1st exhaust gas heat recovery device 24 2nd exhaust gas heat recovery device 25 Flow control valve 25A Switching valve 26 Temperature sensor 27 Controller 28 Refrigerant heat recovery device

Claims

A high-temperature regenerator that evaporates and separates refrigerant by heating and boiling with a combustion device to obtain refrigerant vapor and an intermediate absorption liquid from a rare absorbent, and an intermediate absorption liquid that is generated and supplied by this high-temperature regenerator is generated by a high-temperature regenerator The low-temperature regenerator obtains refrigerant vapor and concentrated absorption liquid from the intermediate absorption liquid by heating with the generated refrigerant vapor, and the refrigerant liquid condensed by heating the intermediate absorption liquid in this low-temperature regenerator is supplied. And a condenser that cools the refrigerant vapor generated and supplied by the low-temperature regenerator to obtain a refrigerant liquid, and the refrigerant liquid supplied from the condenser is sprayed on the heat transfer pipe and flows in the heat transfer pipe An evaporator in which heat is removed from the fluid and the refrigerant evaporates, and the refrigerant vapor generated and supplied by the evaporator is absorbed into the concentrated absorbent supplied by separating the refrigerant vapor from the low-temperature regenerator and supplied as a rare absorbent. The absorber supplied to the high temperature regenerator and the In an absorption refrigerator comprising a low-temperature heat exchanger that exchanges heat between a rare absorption liquid and a concentrated absorption liquid, and a high-temperature heat exchanger that exchanges heat between the intermediate absorption liquid that enters and exits the high-temperature regenerator and the rare absorption liquid ,
A first exhaust gas heat recovery device that exchanges heat between the exhaust gas discharged from the combustion device and the rare absorbent that has passed through the high temperature heat exchanger, an exhaust gas that has passed through the first exhaust gas heat recovery device, and a low temperature heat exchanger The second exhaust gas heat recovery device that exchanges heat with the rare absorbent before passing through the high temperature heat exchanger and the second exhaust gas heat recovery device of the absorption liquid pipe that passes through the second exhaust gas heat recovery device A flow rate control valve located on the upstream side, and a refrigerant heat recovery unit that exchanges heat between the refrigerant flowing toward the condenser via the low-temperature regenerator and the rare absorbent flowing around the low-temperature heat exchanger. An absorption refrigerator characterized by being provided.