JP4090262B2

JP4090262B2 - Absorption refrigerator

Info

Publication number: JP4090262B2
Application number: JP2002110372A
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: 2002-04-12
Filing date: 2002-04-12
Publication date: 2008-05-28
Anticipated expiration: 2022-04-12
Also published as: JP2003302119A; KR20030081154A; CN1229608C; CN1451934A

Description

【０００１】
【発明の属する技術分野】
本発明は、熱効率に優れた吸収式冷凍機に関するものである。
【０００２】
【従来の技術】
図４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１２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２７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２８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２８・高温熱交換器１０・第１の排ガス熱交換器２７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２９の開度を大きくして吸収液管１４に流れる稀吸収液の量を増加し、第２の排ガス熱回収器２８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】
【発明が解決しようとする課題】
しかし、上記従来の吸収式冷凍機においては、流量制御弁が第２の排ガス熱回収器を迂回する吸収液管に設置されていたため、その流量制御弁を全開にしても吸収液管を通って第２の排ガス熱回収器に流れる稀吸収液の量は少なからずあった。
【０００６】
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。
【０００７】
また、ガスバーナから出る排ガスが保有する熱の大半は回収し尽くしており、排ガスから今以上の熱回収を図ると、運転開始時でなくても排ガスに含まれる水蒸気の露点以下に排ガスの温度が低下し、結露して熱回収器や配管部を腐食することがあったので、他の方法によりさらに熱効率の改善を図る必要があり、それが解決すべき課題となっていた。
【０００８】
【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、稀吸収液を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、吸収器から吐出した稀吸収液は分岐して、その一部が前記低温熱交換器で濃吸収液と熱交換する稀吸収液として流れ、残部が前記低温再生器から放熱して吐出した冷媒と熱交換するように冷媒熱回収器へ流れ、前記低温熱交換器及び前記冷媒熱回収器でそれぞれ熱交換した稀吸収液は合流して前記高温再生器へ供給されるよう配管され、前記冷媒熱回収器と低温熱交換器とに分岐して流れる稀吸収液の比率を制御する比率制御手段とを設けた第１の構成の吸収式冷凍機と、
【０００９】
前記第１の構成の吸収式冷凍機において、比率制御手段が、吸収器から冷媒熱回収器に至る吸収液管に設けられた回転数制御可能なポンプ、開度調節可能な流量制御弁、冷媒熱回収器に至る吸収液管と低温熱交換器に至る吸収液管との分岐部に設けられた流量比率調整弁、の何れかであるようにした第２の構成の吸収式冷凍機と、
【００１０】
前記第１または第２の構成の吸収式冷凍機において、吸収器から吐出して冷媒熱回収器に供給される稀吸収液の流量を、稀吸収液と熱交換して低温熱交換器から吐出した濃吸収液の温度に基づいて制御するようにした第３の構成の吸収式冷凍機と、
【００１１】
前記第１または第２の構成の吸収式冷凍機において、吸収器から吐出して冷媒熱回収器に供給される稀吸収液の流量を、稀吸収液と熱交換して冷媒熱回収器から吐出した冷媒の温度に基づいて制御するようにした第４の構成の吸収式冷凍機と、
【００１２】
前記第１または第２の構成の吸収式冷凍機において、吸収器から吐出して冷媒熱回収器に供給される稀吸収液を、吸収器から吐出して高温再生器に至る稀吸収液全体の１０〜３０％に制限するようにした第５の構成の吸収式冷凍機と、
【００１３】
前記第１〜第５何れかの構成の吸収式冷凍機において、低温熱交換器、高温熱交換器、冷媒熱回収器の各入口側にフィルタを設けると共に、各フィルタの前後に差圧を検出する圧力検出手段を設け、この圧力検出手段が検出した差圧に基づいてフィルタの点検を指示する点検指示手段を設けるようにした第６の構成の吸収式冷凍機と、
【００１４】
前記第６の構成の吸収式冷凍機において、低温熱交換器の入口側に設けたフィルタと冷媒熱回収器の入口側に設けたフィルタを、低温熱交換器に至る吸収液管と冷媒熱回収器に至る吸収液管とに分岐する前の吸収液管に設けた共通の一つのフィルタにより代替するようにした第７の構成の吸収式冷凍機と、
を提供するものである。
【００１５】
【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。
【００１６】
本発明の一実施形態を、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の火力によって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は冷媒熱回収器、１２〜１６は吸収液管、１７〜１９は吸収液ポンプ、２０〜２２は冷媒管、２３は冷媒ポンプ、２４は冷水管、２５は冷却水管、２６はガスバーナ２から出る排ガスが通る排気管、２７は第１の排ガス熱回収器、２８は第２の排ガス熱回収器、２９は吸収液管１４との分岐部より下流側で第２の排ガス熱回収器２８より上流側の吸収液管１２に設けられた流量制御弁、３０は排気管２６の下流部分に設けられて排ガスの温度を検出する温度センサ、３１は吸収液管１２の上流部分に設けられて熱交換する前の稀吸収液の温度を検出する温度センサ、３２は吸収液管１６の下流部分に設けられて低温熱交換器９で稀吸収液と熱交換して放熱した濃吸収液の温度を検出する温度センサ、３３は温度センサ３０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２９の開度を制御すると共に、温度センサ３２が検出する温度が所定の温度、例えば４０℃以下に低下しないように吸収液ポンプ１８の回転数を調節して低温熱交換器９を迂回し冷媒熱回収器１１に流れる稀吸収液の量を制御するための制御器である。
【００１７】
また、Ｆ１〜Ｆ６は、低温熱交換器９、高温熱交換器１０、冷媒熱回収器１１それぞれの入口側に設置されたフィルタ、ＰＦ１〜ＰＦ６は、各フィルタの前後に設置されて各フィルタの前後の圧力差を検出するための差圧計であり、検出した圧力差を制御器３３に出力するように構成されている。
【００１８】
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。
【００１９】
高温再生器１で生成された高温の冷媒蒸気は、冷媒管２０の上流部分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１５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、冷媒熱回収器１１が介在する冷媒管２０の下流部分を通って凝縮器４に入る。
【００２０】
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２５内を流れる水と熱交換して凝縮液化し、冷媒管２０から凝縮して供給される冷媒と一緒になって冷媒管２１を通って蒸発器６に入る。
【００２１】
蒸発器６の底に溜まった冷媒液は、冷水管２４に接続された伝熱管２４Ａの上に冷媒管２２に介在する冷媒ポンプ２３によって散布され、冷水管２４を介して供給される水と熱交換して蒸発し、伝熱管２４Ａの内部を流れる水を冷却する。
【００２２】
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、吸収液の濃度が一層高まった吸収液、すなわち吸収液管１６により低温熱交換器９を経由して吸収液ポンプ１９により供給され、上方から散布される濃吸収液に吸収される。
【００２３】
そして、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１７、１８の運転により高温再生器１に戻される。
【００２４】
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２４Ａ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２４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。
【００２５】
上記構成の吸収式冷凍機においては、吸収液ポンプ１７、１８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１２に介在する低温熱交換器９を経由し、残部は吸収液管１３に介在する冷媒熱回収器１１を経由し、それぞれの熱交換器において加熱される。
【００２６】
また、第２の排ガス熱回収器２８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１２に介在する流量制御弁２９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２７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。
【００２７】
すなわち、吸収器７から吸収液管１２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１６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、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２０の約９５℃の冷媒液と冷媒熱回収器１１で熱交換し、温度が上昇する。そして、低温熱交換器９、冷媒熱回収器１１それぞれで熱交換して加熱された稀吸収液は合流し、例えば８０℃前後の稀吸収液となって第２の排ガス熱回収器２８に流入する。
【００２８】
第２の排ガス熱回収器２８に流入する稀吸収液の流量は、吸収液管１２に介在する流量制御弁２９の開度が制御器３３により調節制御される。例えば、制御器３３は温度センサ３０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２９の開度を大きくし、吸収器７から高温再生器１に戻している稀吸収液のより多くを第２の熱回収器２８に供給して排ガスが保有する熱の回収を促進するので、熱効率は改善されガスバーナ２の燃料消費が抑えられる。
【００２９】
また、第２の排ガス熱回収器２８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２８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２７とを経由し、高温再生器１から低温再生器３に吸収液管１５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、ここでもガスバーナ２で消費する燃料が節約される。
【００３０】
さらに、低温再生器３で凝縮して凝縮器４に冷媒管２０の下流部分を通って流入する冷媒液は、前記したように冷媒熱回収器１１で約４０℃の稀吸収液と熱交換してこれを加熱し、冷媒自身は約４５℃に冷却され、冷却水管２５の内部を流れる冷却水に放熱する熱量が減少するので、高温再生器１における所用入熱量が削減でき、この点でも吸収式冷凍機の熱効率が顕著に改善される。
【００３１】
しかも、温度センサ３２が検出する低温熱交換器９で熱交換した後の濃吸収液の温度が所定の４０℃以下にならないように吸収液ポンプ１８の回転数が制御器３３により制御されるので、吸収液管１６の下流部分を流れる濃吸収液が結晶化して吸収液管１６が詰まることがない。
【００３２】
また、温度センサ３０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２８を迂回して吸収液管１４に流れるまで、流量制御弁２９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、排気管２６を介して排気さ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、これにより排ガス温度が低い起動時や部分負荷運転時においても、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。
【００３３】
さらに、低温熱交換器９、高温熱交換器１０、冷媒熱回収器１１の入口側にはフィルタＦ１〜Ｆ６が設置されているので、吸収液や冷媒の流路にスケールなどが入り込んでもフィルタＦ１〜Ｆ６により除去される。
なお、フィルタＦ１とＦ２は、吸収液ポンプ１７の吐出側で配管分岐部上流側に設ける一つのフィルタ（図１に仮想線で示す）により代替することができる。
【００３４】
したがって、低温熱交換器９、高温熱交換器１０、冷媒熱回収器１１などを、例えば特開昭６２−１３１１９６号公報、特開平３−２７１６９７号公報、特開平４−７３５９５号公報、特開平７−１９０６４９号公報、特開平７−２２９６８７号公報などに提案された、流路を狭めて熱交換効率を高めたプレート式熱交換器で構成するときにも、流路が詰まると云った不都合は生じない。
【００３５】
また、フィルタＦ１〜Ｆ６の前後には差圧計ＰＦ１〜ＰＦ６が設置され、各フィルタの前後で所定圧、例えば３０ｋＰａ以上の圧力差が検出されないときには、制御器３３が点検指示手段３４により警報を発する構成となっているので、点検指示手段３４の動作状態を見て当該フィルタの清掃などを行うことで、溶液の正常な循環が確保される。
【００３６】
なお、低温再生器３で中間吸収液を加熱して放熱し、さらに冷媒熱回収器１１でも稀吸収液を加熱して放熱する冷媒の温度は、前記したように４５℃程度まで低下しているので、凝縮器４に送って冷却水管２５内を流れる冷却水で冷却する必要はない。
【００３７】
そのため、冷媒管２０の下流側は凝縮器４ではなく、仮想線で示すように凝縮冷媒が蒸発器６に流入可能に連結し、管長の短縮と配管構成の簡素化とを図ることも可能である（図１では冷媒管２０、２１の図面上の最短部分を仮想線で連結しているが、実際の装置では高温胴５は上方に位置し、低温胴８と冷媒熱回収器１１とは下方に位置するので、低温胴８の蒸発器６と冷媒熱回収器１１とを近接させ、その間を短い冷媒管により連結することが可能。）。
【００３８】
また、吸収液ポンプ１８に代えて、図２に示したように吸収液管１３に流量制御弁１８Ａを設置する。あるいは、図３に示したように吸収液管１２、１３の分岐部に流量比率調整弁１８Ｂを設置し、流量制御弁１８Ａまたは流量比率調整弁１８Ｂを、温度センサ３２が検出する低温熱交換器９で放熱した後の濃吸収液の温度が前記所定の４０℃以下にならないように、低温熱交換器９に流れる稀吸収液の量を制御器３３により制御するように構成することも可能である。
【００３９】
また、吸収液ポンプ１８、流量制御弁１８Ａ、流量比率調整弁１８Ｂを吸収液管１３（吸収液管１２との分岐部・合流部を含む）に設けるのではなく、吸収器７から吐出したき吸収液の１０〜３０％が低温熱交換器９を迂回して冷媒熱回収器１１に流れるように、冷媒熱回収器１１および吸収液管１３の内部抵抗（管径・管長など）を決定・施工することも可能である。
【００４０】
また、温度センサ３２に代えて、温度センサ３２Ａを冷媒熱回収器１１で稀吸収液と熱交換して放熱した冷媒の温度が検出可能に冷媒管２０の下流側に設置し、その温度センサ３２Ａが検出する冷媒熱回収器１１で熱交換した後の冷媒の温度が、例えば温度センサ３１が検出する冷媒熱回収器１１で熱交換する前の稀吸収液の温度＋所定温度、例えば５℃だけ高い温度となるように、吸収液ポンプ１８の回転数、流量制御弁１８Ａ、流量比率調整弁１８Ｂの開度などを制御器３３により制御するように構成し、凝縮器４あるいは蒸発器６に直接供給する凝縮冷媒の温度を所定温度まで確実に低下させる構成とすることも可能である。
【００４１】
また、高価な流量制御弁２９に代えて、廉価な開閉弁を第２の熱回収器２８上流側の吸収液管１２に設置する、あるいは廉価な切替弁を吸収液管１２、１４の分岐部（または合流部）に設置するなどし、温度センサ３０が検出する排ガス温度が所定の温度、例えば１００℃を下回らないように、制御器３３により弁の開閉、切替を制御する構成とすることもできる。
【００４２】
また、第２の熱回収器２８を迂回する吸収液管１４に代えて、第２の熱回収器２８を迂回する排気管を設けると共に、その排気管との分岐部（あるいは合流部）に流路切換弁を設ける。あるいは、第２の熱回収器２８を経由する排気管に開閉弁を設けるなどして、第２の熱回収器２８に流れて稀吸収液と熱交換した排ガスの温度が所定の１００℃より低下しないように制御器３３によりその弁の開閉、切替を制御する構成としてもよい。
【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２５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２４Ａ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）２４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、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。
【００４５】
また、フィルタＦ１〜Ｆ６それぞれの前後に圧力計を設置してフィルタの前後の圧力を検出し、フィルタの前後で所定の圧力差が検出されなくなったときに当該フィルタの清掃を指示する警報手段を設けることも可能である。
【００４６】
【発明の効果】
以上説明したように本発明によれば、吸収器から吐出した稀吸収液の一部が低温再生器から放熱して吐出した冷媒と低温熱交換器を迂回して熱交換する冷媒熱回収器と、この冷媒熱回収器と低温熱交換器とに分岐して流れる稀吸収液の比率を制御する比率制御手段とが設置されているので、低温再生器内で中間吸収液に放熱して凝縮し、冷媒管に吐出した冷媒が保有する余熱は冷媒熱回収器において稀吸収液により熱回収可能され、高温再生器に添設された燃焼装置の燃料消費量が削減できる。
【００４７】
しかも、冷媒熱回収器と低温熱交換器とに分岐して流れる稀吸収液の比率が制御可能であり、例えばその比率を、吸収器から吐出して冷媒熱回収器に供給される稀吸収液の流量を、稀吸収液と熱交換して低温熱交換器から吐出した濃吸収液の温度に基づいて制御して調整するようにした吸収式冷凍機においては、前記濃吸収液の温度を適切な温度に設定することにより、低温熱交換器で稀吸収液に放熱して吸収器に流入する濃吸収液の結晶化を防止することが可能となる。
【００４８】
また、吸収器から吐出して冷媒熱回収器に供給される稀吸収液の流量を、稀吸収液と熱交換して冷媒熱回収器から吐出した冷媒の温度に基づいて制御し、前記比率を制御するように構成した吸収式冷凍機においては、前記冷媒の温度を適切な温度に設定することにより、凝縮冷媒の温度を所定温度まで確実に低下させることが可能であり、凝縮器で放熱させる必要量が減少し、凝縮冷媒を蒸発器に直接供給する配管構成とすることも可能となる。
【００４９】
また、吸収器から吐出して冷媒熱回収器に供給される稀吸収液を、吸収器から吐出して高温再生器に至る稀吸収液全体の１０〜３０％に制限するように構成した吸収式冷凍機においては、低温熱交換器で稀吸収液と熱交換して放熱する濃吸収液の温度は確実に低下する。そのため、濃吸収液が流入する吸収器では、冷媒は吸収液に速やかに吸収される。
【００５０】
また、低温熱交換器、高温熱交換器、冷媒熱回収器の各入口側にフィルタを設置すると共に、各フィルタの前後に差圧を検出する圧力検出手段を設け、この圧力検出手段が検出した差圧に基づいてフィルタの点検を指示する点検指示手段を設けるように構成した吸収式冷凍機においては、吸収液や冷媒の流路にスケールなどが入り込んでもフィルタにより除去される。
【００５１】
したがって、低温熱交換器、高温熱交換器、冷媒熱回収器などを、例えば特開昭６２−１３１１９６号公報、特開平３−２７１６９７号公報、特開平４−７３５９５号公報、特開平７−１９０６４９号公報、特開平７−２２９６８７号公報などに提案された、流路を狭めて熱交換効率を高めたプレート式熱交換器で構成するときにも、流路が詰まると云った不都合は生じない。また、点検指示手段の動作状態を見て当該フィルタの清掃などを行うことで、溶液の正常な循環が確保される。
【図面の簡単な説明】
【図１】本発明の実施形態を示す説明図である。
【図２】本発明の変形実施形態を示す説明図である。
【図３】本発明の他の変形実施形態を示す説明図である。
【図４】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低温胴
９低温熱交換器
１０高温熱交換器
１１冷媒熱回収器
１２〜１６吸収液管
１７、１８吸収液ポンプ
１８Ａ流量制御弁
１８Ｂ流量比率調整弁
２０〜２２冷媒管
２３冷媒ポンプ
２４冷水管
２５冷却水管
２６排気管
２７第１の排ガス熱回収器
２８第２の排ガス熱回収器
２９流量制御弁
２９Ａ切替弁
２９流量制御弁
３０〜３２、３２Ａ温度センサ
３３制御器
３４点検指示手段
Ｆ１〜Ｆ６フィルタ
ＰＦ１〜ＰＦ６差圧計[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an absorption refrigerator having excellent thermal efficiency.
[0002]
[Prior art]
As shown in FIG. 4, exhaust gas discharged from the gas burner 2 that heats and boiles 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 absorbent liquid pipe 12. Sequentially sent to the first exhaust gas heat recovery device 27 and the second exhaust gas heat recovery device 28 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 chiller 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 supplied to the low-temperature heat exchanger 9, the second exhaust gas heat recovery unit 28, and the high Heated by the hot heat exchanger 10 and the first exhaust gas heat exchanger 27 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 amount of the rare absorbent flowing through the absorbent liquid pipe 14 with the opening of the flow control valve 29 increased. The heat recovery from the exhaust gas in the second exhaust gas heat recovery unit 28 is decreased to prevent a significant decrease in the exhaust gas temperature, and the condensation / condensation of water vapor contained in the exhaust gas is prevented.
[0005]
[Problems to be solved by the invention]
However, in the above-described conventional absorption refrigerator, the flow control valve is installed in the absorption liquid pipe that bypasses the second exhaust gas heat recovery device, so that even if the flow control valve is fully opened, the flow control valve passes through the absorption liquid pipe. The amount of the rare absorbent flowing through the second exhaust gas heat recovery device was not small.
[0006]
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, and heat exchangers and The exhaust pipe could be corroded.
[0007]
In addition, most of the heat held by the exhaust gas from the gas burner has been recovered, and if heat recovery from the exhaust gas is attempted, the temperature of the exhaust gas will be below the dew point of the water vapor contained in the exhaust gas even when the operation is not started. Since the heat recovery device and the piping part may corrode due to a decrease in condensation, it is necessary to further improve the thermal efficiency by another method, which has been a problem to be solved.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems of the prior art, the present invention heats and boiles a rare absorbent and evaporates and separates the refrigerant to obtain refrigerant vapor and an intermediate absorbent from the rare absorbent, and the high temperature regenerator produces the refrigerant. The low-temperature regenerator that heats the intermediate absorbing liquid supplied by the refrigerant vapor generated by the high-temperature regenerator, further evaporates and separates the refrigerant, and obtains the refrigerant vapor and the concentrated absorbing liquid from the intermediate absorbing liquid. A refrigerant liquid condensed by heating the intermediate absorption liquid is supplied, a condenser for cooling 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 spread on the heat transfer tube, and heat is removed from the fluid flowing in the heat transfer tube to evaporate the refrigerant, and the refrigerant vapor generated and supplied by this evaporator is separated from the low temperature regenerator. Absorbed in the concentrated absorbent supplied to make 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 chiller equipped with a high temperature heat exchanger, the rare absorbent discharged from the absorber branches and part of it flows as a rare absorbent that exchanges heat with the concentrated absorbent in the low temperature heat exchanger. The remaining portion flows to the refrigerant heat recovery unit so as to exchange heat with the refrigerant discharged from the low-temperature regenerator, and the rare absorption liquids that exchange heat with the low-temperature heat exchanger and the refrigerant heat recovery unit respectively merge. Absorption type of the first configuration provided with ratio control means that is piped to be supplied to the high-temperature regenerator and that controls the ratio of the rare absorbent that branches and flows into the refrigerant heat recovery unit and the low-temperature heat exchanger. A refrigerator,
[0009]
In the absorption refrigerator having the first configuration, the ratio control means includes a pump capable of controlling the number of revolutions provided in an absorption liquid pipe extending from the absorber to the refrigerant heat recovery unit, a flow rate control valve capable of adjusting the opening degree, and a refrigerant. An absorption refrigerator having a second configuration configured to be one of a flow rate adjusting valve provided at a branch portion between the absorption liquid pipe leading to the heat recovery unit and the absorption liquid pipe leading to the low-temperature heat exchanger;
[0010]
In the absorption refrigerator having the first or second configuration, the flow rate of the rare absorbent discharged from the absorber and supplied to the refrigerant heat recovery unit is exchanged with the rare absorbent and discharged from the low-temperature heat exchanger. An absorption refrigerator having a third configuration that is controlled based on the temperature of the concentrated absorbent,
[0011]
In the absorption chiller having the first or second configuration, the flow rate of the rare absorbent discharged from the absorber and supplied to the refrigerant heat recovery unit is exchanged with the rare absorption liquid and discharged from the refrigerant heat recovery unit. An absorption refrigerator having a fourth configuration, which is controlled based on the temperature of the refrigerant,
[0012]
In the absorption chiller having the first or second configuration, the rare absorbing liquid discharged from the absorber and supplied to the refrigerant heat recovery unit is discharged from the absorber to the entire high temperature regenerator. An absorption refrigerating machine of the fifth configuration which is limited to 10 to 30%;
[0013]
In the absorption refrigerator having any one of the first to fifth configurations, a filter is provided on each inlet side of the low-temperature heat exchanger, the high-temperature heat exchanger, and the refrigerant heat recovery device, and a differential pressure is detected before and after each filter. An absorption refrigeration machine having a sixth structure, wherein pressure check means is provided, and check instruction means is provided for instructing check of the filter based on the differential pressure detected by the pressure detection means;
[0014]
In the absorption refrigerator having the sixth configuration, the filter provided on the inlet side of the low-temperature heat exchanger and the filter provided on the inlet side of the refrigerant heat recovery device are connected to the absorption liquid pipe and the refrigerant heat recovery to the low-temperature heat exchanger. An absorption refrigerating machine of a seventh configuration that is replaced by a common filter provided in the absorption liquid pipe before branching to the absorption liquid pipe leading to the container;
Is to provide.
[0015]
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.
[0016]
An 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 evaporate and separate the refrigerant by heating the absorbing liquid by the heating power of a gas burner 2 using, for example, city gas, 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 is a refrigerant heat recovery unit, 12 to 16 are absorption liquid tubes, 17 to 19 are absorption liquid pumps, 20 to 22 are refrigerant tubes, 23 is a refrigerant pump, 24 is a cold water tube, and 25 is cooling The water pipe, 26 is an exhaust pipe through which the exhaust gas from the gas burner 2 passes, 27 is a first exhaust gas heat recovery device, 28 is a second exhaust gas heat recovery device, and 29 is a second downstream of the branching portion with the absorption liquid tube 14. The flow rate control valve 30 provided in the absorption liquid pipe 12 upstream from the exhaust gas heat recovery device 28 of A temperature sensor that is provided in the downstream portion of the trachea 26 and detects the temperature of the exhaust gas, 31 is a temperature sensor that is provided in the upstream portion of the absorption liquid pipe 12 and detects the temperature of the rare absorbent before heat exchange, and 32 is the absorption A temperature sensor 33 is provided in the downstream portion of the liquid pipe 16 and detects the temperature of the concentrated absorbent that has exchanged heat with the rare absorbent in the low-temperature heat exchanger 9, and 33 is a predetermined temperature, for example, 100 ° C. The degree of opening of the flow rate control valve 29 is controlled so as to continue to be detected, and the rotational speed of the absorption pump 18 is adjusted so that the temperature detected by the temperature sensor 32 does not drop to a predetermined temperature, for example, 40 ° C. or less. This is a controller for controlling the amount of the rare absorbent that bypasses the low-temperature heat exchanger 9 and flows to the refrigerant heat recovery unit 11.
[0017]
F1 to F6 are filters installed on the inlet side of each of the low temperature heat exchanger 9, the high temperature heat exchanger 10 and the refrigerant heat recovery unit 11, and PF1 to PF6 are installed before and after each filter. It is a differential pressure gauge for detecting the pressure difference between the front and the back, and is configured to output the detected pressure difference to the controller 33.
[0018]
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.
[0019]
The high-temperature refrigerant vapor generated in the high-temperature regenerator 1 passes through the upstream portion of the refrigerant pipe 20 and enters the low-temperature regenerator 3, and is generated in the high-temperature regenerator 1 and passes through the high-temperature heat exchanger 10 through the absorption liquid pipe 15. Then, the intermediate absorption liquid that has entered the low-temperature regenerator 3 is heated and condensed, and enters the condenser 4 through a downstream portion of the refrigerant pipe 20 in which the refrigerant heat recovery unit 11 is interposed.
[0020]
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 25 to be condensed and liquefied, and is condensed and supplied from the refrigerant pipe 20. The refrigerant enters the evaporator 6 through the refrigerant pipe 21 together with the refrigerant.
[0021]
The refrigerant liquid accumulated at the bottom of the evaporator 6 is sprayed by the refrigerant pump 23 interposed in the refrigerant pipe 22 on the heat transfer pipe 24 A connected to the cold water pipe 24, and water and heat supplied through the cold water pipe 24. The water which exchanges and evaporates and flows through the inside of the heat transfer tube 24A is cooled.
[0022]
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 whose concentration of the absorption liquid is further increased, that is, the low-temperature heat exchanger 9 by the absorption liquid pipe 16. Is supplied by the absorption liquid pump 19 via, and is absorbed by the concentrated absorption liquid sprayed from above.
[0023]
Then, the absorbing liquid whose concentration has been reduced by absorbing the refrigerant by the absorber 7, that is, the rare absorbing liquid, is returned to the high-temperature regenerator 1 by the operation of the absorbing liquid pumps 17 and 18.
[0024]
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 24A piped inside the evaporator 6 becomes an air conditioning load (not shown) via the cold water pipe 24. Since it can be circulated, cooling operation such as cooling can be performed.
[0025]
In the absorption refrigerator having the above-described configuration, a part of the rare absorbent returned to the high-temperature regenerator 1 from the absorber 7 by the operation of the absorbent pumps 17 and 18 is supplied to the low-temperature heat exchanger 9 interposed in the absorbent pipe 12. The remainder passes through the refrigerant heat recovery device 11 interposed in the absorption liquid tube 13 and is heated in each heat exchanger.
[0026]
In addition, 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 28 is controlled by a flow rate control valve 29 interposed in the absorbent liquid pipe 12, and the high temperature heat exchanger 10. In the first exhaust gas heat recovery unit 27, the entire amount of the diluted absorbent returning from the absorber 7 to the high-temperature regenerator 1 flows and is heated by each.
[0027]
That is, a part of the about 40 ° C. rare absorption liquid discharged from the absorber 7 to the absorption liquid pipe 12 is discharged to the absorption liquid pipe 16 from the low-temperature regenerator 3 and flows into the absorption liquid 7 at a concentration of about 90 ° C. Heat is exchanged with the refrigerant liquid at a temperature of about 95 ° C. in the refrigerant pipe 20 flowing through the condenser 4 and the refrigerant condensed at the low-temperature regenerator 3 and the remainder is condensed at the low-temperature heat exchanger 9 and the refrigerant heat recovery unit 11. , The temperature rises. Then, the rare absorption liquid heated and exchanged in the low-temperature heat exchanger 9 and the refrigerant heat recovery apparatus 11 merges, and flows into the second exhaust gas heat recovery apparatus 28 as, for example, a rare absorption liquid at around 80 ° C. To do.
[0028]
The flow rate of the rare absorption liquid flowing into the second exhaust gas heat recovery unit 28 is controlled and controlled by the controller 33 with the opening degree of the flow rate control valve 29 interposed in the absorption liquid pipe 12. For example, the controller 33 increases the degree of opening of the flow control valve 29 when the temperature sensor 30 detects a temperature higher than a predetermined temperature of 100 ° C., and the rare absorbent that is returned from the absorber 7 to the high-temperature regenerator 1. More is supplied to the second heat recovery unit 28 to promote the recovery of the heat held in the exhaust gas, so that the thermal efficiency is improved and the fuel consumption of the gas burner 2 is suppressed.
[0029]
Further, the rare absorbent that has been heated via the second exhaust gas heat recovery device 28 and the rare absorbent that has not passed through the second exhaust gas heat recovery device 28 and therefore has not been heated are joined together to generate high-temperature heat. The intermediate absorbing liquid flowing from the high temperature regenerator 1 to the low temperature regenerator 3 through the absorbing liquid pipe 15 via the exchanger 10 and the first exhaust gas heat recovery unit 27, and about 200 discharged from the gas burner 2 Heat exchange with the exhaust gas at 0 ° C. results in a rare absorbent of about 140 ° C. and flows into the high-temperature regenerator 1, so that the fuel consumed by the gas burner 2 is saved here as well.
[0030]
Further, the refrigerant liquid condensed in the low temperature regenerator 3 and flowing into the condenser 4 through the downstream portion of the refrigerant pipe 20 is heat-exchanged with the rare absorbing liquid of about 40 ° C. in the refrigerant heat recovery unit 11 as described above. The refrigerant itself is cooled to about 45 ° C., and the amount of heat dissipated to the cooling water flowing inside the cooling water pipe 25 is reduced, so that the required heat input in the high-temperature regenerator 1 can be reduced, and this is also absorbed. The thermal efficiency of the refrigerator is significantly improved.
[0031]
In addition, since the rotational speed of the absorbent pump 18 is controlled by the controller 33 so that the temperature of the concentrated absorbent after the heat exchange by the low temperature heat exchanger 9 detected by the temperature sensor 32 does not fall below a predetermined 40 ° C. The concentrated absorption liquid flowing in the downstream portion of the absorption liquid pipe 16 is not crystallized and the absorption liquid pipe 16 is not clogged.
[0032]
Further, when the temperature sensor 30 detects a temperature lower than 100 ° C., the flow rate control valve 29 is set to the maximum until the entire amount of the rare absorbing liquid flows to the absorbing liquid pipe 14 bypassing the second exhaust gas heat recovery device 28. Since the amount of heat recovered from the exhaust gas can be suppressed to a maximum of zero by throttling to the fully closed state, the temperature of the exhaust gas exhausted through the exhaust pipe 26 is the dew point temperature (city gas, that is, when natural gas is used as fuel). The dew point temperature of the combustion exhaust gas is maintained at 100 ° C., which is higher than 60 to 70 ° C., so that the water vapor contained in the exhaust gas is condensed and drain water is generated even during start-up and partial load operation where the exhaust gas temperature is low. It does not cause corrosion problems due to drain water.
[0033]
Furthermore, since the filters F1 to F6 are installed on the inlet side of the low-temperature heat exchanger 9, the high-temperature heat exchanger 10, and the refrigerant heat recovery unit 11, the filter F1 even if a scale or the like enters the absorption liquid or refrigerant flow path. Removed by ~ F6.
Note that the filters F1 and F2 can be replaced by one filter (shown in phantom lines in FIG. 1) provided on the discharge side of the absorption liquid pump 17 on the upstream side of the pipe branching portion.
[0034]
Accordingly, the low temperature heat exchanger 9, the high temperature heat exchanger 10, the refrigerant heat recovery device 11, etc. are disclosed in, for example, JP-A-62-113196, JP-A-3-271597, JP-A-4-73595, Even when the plate-type heat exchanger, which is proposed in Japanese Patent Laid-Open No. 7-190649, Japanese Patent Laid-Open No. 7-229687, etc., has a narrow flow path to increase heat exchange efficiency, the flow path is clogged. Does not occur.
[0035]
In addition, differential pressure gauges PF1 to PF6 are installed before and after the filters F1 to F6. When a predetermined pressure, for example, a pressure difference of 30 kPa or more is not detected before and after each filter, the controller 33 issues an alarm by the inspection instruction means 34. Since it is configured, normal circulation of the solution is ensured by cleaning the filter while looking at the operating state of the inspection instruction means 34.
[0036]
It should be noted that the temperature of the refrigerant that heats the intermediate absorption liquid by the low-temperature regenerator 3 to dissipate heat and further heats the rare absorption liquid by the refrigerant heat recovery unit 11 to dissipate heat is reduced to about 45 ° C. as described above. Therefore, it is not necessary to cool with the cooling water that is sent to the condenser 4 and flows through the cooling water pipe 25.
[0037]
Therefore, the downstream side of the refrigerant pipe 20 is connected not to the condenser 4 but to the condensed refrigerant so that the refrigerant can flow into the evaporator 6 as indicated by the phantom line, so that the pipe length can be shortened and the piping configuration can be simplified. 1 (in FIG. 1, the shortest portion of the refrigerant pipes 20 and 21 on the drawing is connected by an imaginary line, but in an actual apparatus, the high temperature cylinder 5 is located above, and the low temperature cylinder 8 and the refrigerant heat recovery device 11 are Since it is located below, it is possible to bring the evaporator 6 and the refrigerant heat recovery device 11 of the low temperature cylinder 8 close to each other and connect them with a short refrigerant pipe.)
[0038]
Further, instead of the absorption liquid pump 18, a flow rate control valve 18A is installed in the absorption liquid pipe 13 as shown in FIG. Alternatively, as shown in FIG. 3, a low-temperature heat exchanger in which a flow rate adjusting valve 18B is installed at a branch portion of the absorbing liquid pipes 12 and 13 and the flow rate control valve 18A or the flow rate adjusting valve 18B is detected by the temperature sensor 32. It is also possible to configure the controller 33 to control the amount of the rare absorbent flowing into the low-temperature heat exchanger 9 so that the temperature of the concentrated absorbent after radiating heat at 9 does not fall below the predetermined 40 ° C. is there.
[0039]
Further, the absorption liquid pump 18, the flow rate control valve 18 A, and the flow rate ratio adjustment valve 18 B are not provided in the absorption liquid pipe 13 (including a branching / merging part with the absorption liquid pipe 12), but discharged from the absorber 7. The internal resistance (tube diameter, tube length, etc.) of the refrigerant heat recovery device 11 and the absorption liquid pipe 13 is determined so that 10 to 30% of the absorption liquid bypasses the low-temperature heat exchanger 9 and flows to the refrigerant heat recovery device 11. Construction is also possible.
[0040]
Further, instead of the temperature sensor 32, the temperature sensor 32A is installed on the downstream side of the refrigerant pipe 20 so as to be able to detect the temperature of the refrigerant radiated by exchanging heat with the rare absorbent in the refrigerant heat recovery device 11, and the temperature sensor 32A. The temperature of the refrigerant after the heat exchange with the refrigerant heat recovery device 11 detected by the refrigerant is, for example, the temperature of the rare absorbent before the heat exchange with the refrigerant heat recovery device 11 detected by the temperature sensor 31 + a predetermined temperature, for example, 5 ° C. The controller 33 is configured to control the rotational speed of the absorption liquid pump 18, the flow rate control valve 18 A, the flow rate adjustment valve 18 B, and the like so that the temperature becomes high, and directly to the condenser 4 or the evaporator 6. A configuration in which the temperature of the condensed refrigerant to be supplied is reliably lowered to a predetermined temperature can also be adopted.
[0041]
Further, instead of the expensive flow rate control valve 29, an inexpensive on-off valve is installed in the absorption liquid pipe 12 upstream of the second heat recovery device 28, or an inexpensive switching valve is provided at the branch portion of the absorption liquid pipes 12 and 14. It is also possible to use a configuration in which the controller 33 controls opening / closing and switching of the valve so that the exhaust gas temperature detected by the temperature sensor 30 does not fall below a predetermined temperature, for example, 100 ° C. it can.
[0042]
In addition, instead of the absorption liquid pipe 14 that bypasses the second heat recovery device 28, an exhaust pipe that bypasses the second heat recovery device 28 is provided, and flows to a branch (or junction) with the exhaust pipe. A path switching valve is provided. Alternatively, the temperature of the exhaust gas flowing through the second heat recovery device 28 and exchanging heat with the rare absorbent is lowered from a predetermined 100 ° C. by providing an open / close valve in the exhaust pipe that passes through the second heat recovery device 28. It is good also as a structure which controls the opening / closing and switching of the valve by the controller 33 so that it may not.
[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 25, and is heated to, for example, about 55 ° C. by the heat transfer pipe 24A of the evaporator 6. The water may be circulated and supplied to a load via a cold water pipe (preferably referred to as a hot water pipe when hot water circulates) 24 so that heating operation such as heating can be performed.
[0044]
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.
[0045]
Also, a pressure gauge is installed before and after each of the filters F1 to F6 to detect the pressure before and after the filter, and alarm means for instructing cleaning of the filter when a predetermined pressure difference is no longer detected before and after the filter It is also possible to provide it.
[0046]
【The invention's effect】
As described above, according to the present invention, a refrigerant heat recovery unit that bypasses the low temperature heat exchanger and exchanges heat with a refrigerant that a part of the rare absorbent discharged from the absorber dissipates heat from the low temperature regenerator and is discharged. Since a ratio control means for controlling the ratio of the rare absorbent that branches and flows into the refrigerant heat recovery device and the low temperature heat exchanger is installed, the heat is dissipated and condensed in the intermediate absorbent in the low temperature regenerator. The residual heat held by the refrigerant discharged to the refrigerant pipe can be recovered by the refrigerant absorber in the refrigerant heat recovery device, and the fuel consumption of the combustion device attached to the high temperature regenerator can be reduced.
[0047]
Moreover, the ratio of the rare absorbent that branches and flows between the refrigerant heat recovery unit and the low-temperature heat exchanger can be controlled. For example, the ratio of the rare absorbent that is discharged from the absorber and supplied to the refrigerant heat recovery unit In an absorption chiller in which the flow rate of the refrigerant is controlled and adjusted based on the temperature of the concentrated absorbent discharged from the low-temperature heat exchanger after heat exchange with the rare absorbent, the temperature of the concentrated absorbent is appropriately set. By setting the temperature to a low temperature, it is possible to prevent crystallization of the concentrated absorbent flowing into the absorber after releasing heat to the rare absorbent with the low-temperature heat exchanger.
[0048]
Further, the flow rate of the rare absorbing liquid discharged from the absorber and supplied to the refrigerant heat recovery unit is controlled based on the temperature of the refrigerant discharged from the refrigerant heat recovery unit after exchanging heat with the rare absorbing liquid, and the ratio is set. In an absorption refrigerator configured to be controlled, the temperature of the condensed refrigerant can be reliably lowered to a predetermined temperature by setting the temperature of the refrigerant to an appropriate temperature, and heat is radiated by the condenser. The required amount is reduced, and a piping configuration that directly supplies the condensed refrigerant to the evaporator can be realized.
[0049]
Moreover, the absorption type comprised so that the rare absorption liquid discharged from an absorber and supplied to a refrigerant | coolant heat recovery device may be limited to 10 to 30% of the whole rare absorption liquid discharged from an absorber and reaching a high temperature regenerator. In the refrigerator, the temperature of the concentrated absorbent that radiates heat by exchanging heat with the rare absorbent in the low-temperature heat exchanger is surely lowered. Therefore, in the absorber into which the concentrated absorbent flows, the refrigerant is quickly absorbed by the absorbent.
[0050]
In addition, a filter is installed on each inlet side of the low-temperature heat exchanger, the high-temperature heat exchanger, and the refrigerant heat recovery device, and pressure detection means for detecting a differential pressure is provided before and after each filter, and this pressure detection means detects In an absorption refrigerator configured to provide inspection instruction means for instructing inspection of a filter based on a differential pressure, even if a scale or the like enters an absorption liquid or refrigerant flow path, it is removed by the filter.
[0051]
Accordingly, a low-temperature heat exchanger, a high-temperature heat exchanger, a refrigerant heat recovery device, etc. are disclosed in, for example, Japanese Patent Laid-Open Nos. 62-131196, 3-271697, 4-73595, and 7-190649. The inconvenience that the channel is clogged does not occur even when the plate-type heat exchanger proposed in Japanese Patent Application Laid-Open No. 7-229687 and the like is used to increase the heat exchange efficiency by narrowing the channel. . Also, the normal circulation of the solution is ensured by cleaning the filter while looking at the operating state of the inspection instruction means.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an embodiment of the present invention.
FIG. 2 is an explanatory view showing a modified embodiment of the present invention.
FIG. 3 is an explanatory view showing another modified embodiment of the present invention.
FIG. 4 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 drum 6 Evaporator 7 Absorber 8 Low temperature drum 9 Low temperature heat exchanger 10 High temperature heat exchanger 11 Refrigerant heat recovery device 12-16 Absorption liquid pipes 17 and 18 Absorption Liquid pump 18A Flow control valve 18B Flow rate adjustment valve 20-22 Refrigerant pipe 23 Refrigerant pump 24 Chilled water pipe 25 Cooling water pipe 26 Exhaust pipe 27 First exhaust gas heat recovery device 28 Second exhaust gas heat recovery device 29 Flow control valve 29A switching Valve 29 Flow control valves 30 to 32, 32A Temperature sensor 33 Controller 34 Inspection instruction means F1 to F6 Filters PF1 to PF6 Differential pressure gauge

Claims

A high-temperature regenerator that evaporates and separates refrigerant by heating and boiling the rare absorbent and obtains refrigerant vapor and intermediate absorbent from the rare absorbent, and the intermediate absorbent that is generated and supplied by the high-temperature regenerator A low-temperature regenerator that heats the generated refrigerant vapor to further evaporate and separate the refrigerant and obtains refrigerant vapor and concentrated absorbent from the intermediate absorbent, and a refrigerant liquid that is condensed by heating the intermediate absorbent 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, An evaporator that draws heat from the flowing fluid and evaporates the refrigerant, and the refrigerant vapor generated and supplied by this evaporator is absorbed by the concentrated absorbent supplied by separating the refrigerant vapor from the low-temperature regenerator and supplied rarely An absorber to be supplied to the high-temperature regenerator and to the absorber. 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 The rare absorbent discharged from the absorber branches, part of which flows as a rare absorbent that exchanges heat with the concentrated absorbent in the low-temperature heat exchanger, and the remaining refrigerant radiates and discharges from the low-temperature regenerator The refrigerant is flowed to the refrigerant heat recovery unit so as to exchange heat with the refrigerant, and the rare absorption liquid exchanged with the low temperature heat exchanger and the refrigerant heat recovery unit is joined to be supplied to the high temperature regenerator. An absorption refrigerator comprising a ratio control means for controlling a ratio of a rare absorbent that branches and flows into a heat recovery unit and a low-temperature heat exchanger.

The ratio control means is a low-temperature heat exchange with the absorption liquid pipe leading to the refrigerant heat recovery device, a pump capable of controlling the number of revolutions provided in the absorption liquid pipe extending from the absorber to the refrigerant heat recovery device, the flow rate control valve capable of adjusting the opening degree. The absorption refrigeration machine according to claim 1, wherein the absorption chiller is any one of a flow rate ratio adjusting valve provided at a branch portion with the absorption liquid pipe leading to the container.

The flow rate of the rare absorbent discharged from the absorber and supplied to the refrigerant heat recovery unit is controlled based on the temperature of the concentrated absorbent discharged from the low-temperature heat exchanger by exchanging heat with the rare absorbent. The absorption refrigerator according to claim 1 or 2.

The flow rate of the rare absorbing liquid discharged from the absorber and supplied to the refrigerant heat recovery unit is controlled based on the temperature of the refrigerant discharged from the refrigerant heat recovery unit after exchanging heat with the rare absorbing liquid. The absorption refrigerator according to claim 1 or 2.

The rare absorbing liquid discharged from the absorber and supplied to the refrigerant heat recovery device is limited to 10 to 30% of the entire rare absorbing liquid discharged from the absorber and reaching the high temperature regenerator. The absorption refrigerator according to 1 or 2.

A filter is provided on each inlet side of the low-temperature heat exchanger, high-temperature heat exchanger, and refrigerant heat recovery unit, and pressure detection means for detecting a differential pressure is provided before and after each filter, and the difference detected by the pressure detection means is provided. 6. The absorption chiller according to claim 1, further comprising inspection instruction means for instructing inspection of the filter based on the pressure.

A filter provided on the inlet side of the low-temperature heat exchanger and a filter provided on the inlet side of the refrigerant heat recovery device branch into an absorption liquid tube leading to the low-temperature heat exchanger and an absorption liquid tube reaching the refrigerant heat recovery device. 7. The absorption refrigerator according to claim 6, wherein the absorption refrigerator is replaced by a common filter provided in the previous absorption liquid pipe.