JP3851204B2

JP3851204B2 - Absorption refrigerator

Info

Publication number: JP3851204B2
Application number: JP2002092104A
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: 2006-11-29
Anticipated expiration: 2022-03-28
Also published as: CN1448670A; JP2003287315A; KR20030078701A; KR100493598B1

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３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２６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２７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２７・高温熱交換器１０・第１の排ガス熱交換器２６それぞれで加熱され、１３５℃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２８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２７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２８が第２の排ガス熱回収器２７を迂回する吸収液管１４に設けられていたため、流量制御弁２８を全開にしても吸収液管１４を通って第２の排ガス熱回収器２７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】
【発明が解決しようとする課題】
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天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、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、
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、冷媒熱回収器で稀吸収液に放熱した冷媒を凝縮器に導入する冷媒管に流路抵抗を付与する流量制御弁を設け、この流量制御弁より下流側に冷媒の温度を検出する温度センサを設け、冷媒熱回収器を吐出した冷媒の温度が、稀吸収液の熱交換前温度＋所定温度α（但し、α＞０）となるように流量制御弁を介して冷媒の流路抵抗が制御されることを特徴とする吸収式冷凍機を提供するものである。
【００１１】
【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。
【００１２】
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、１８は吸収液ポンプ、１９〜２１は冷媒管、２２は冷媒ポンプ、２３は冷水管、２４は冷却水管、２５はガスバーナ２から出る排ガスが通る排気管、２６は第１の排ガス熱回収器、２７は第２の排ガス熱回収器、２８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２７より上流側の吸収液管１２に設けられた流量制御弁、２９は冷媒管１９の冷媒熱回収器１１より下流側に設けられた流量制御弁、３０は排気管２５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は冷媒管１９の下流部分に設けられて冷媒熱回収器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２８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、温度センサ３１が検出する温度＋所定温度α（但し、α>０）となるように流量制御弁２９の開度を調節して冷媒管１９の流路抵抗を制御するための制御器である。
【００１３】
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。
【００１４】
高温再生器１で生成された高温の冷媒蒸気は、冷媒管１９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１９の下流部分を通って凝縮器４に入る。
【００１５】
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２４内を流れる水と熱交換して凝縮液化し、冷媒管１９から凝縮して供給される冷媒と一緒になって冷媒管２０を通って蒸発器６に入る。
【００１６】
蒸発器６の底に溜まった冷媒液は、冷水管２３に接続された伝熱管２３Ａの上に冷媒管２１に介在する冷媒ポンプ２２によって散布され、冷水管２３を介して供給される水と熱交換して蒸発し、伝熱管２３Ａの内部を流れる水を冷却する。
【００１７】
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１８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。
【００１８】
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の運転により高温再生器１に戻される。
【００１９】
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２３Ａ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２３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。
【００２０】
上記構成の吸収式冷凍機においては、吸収液ポンプ１７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。
【００２１】
また、第２の排ガス熱回収器２７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２８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２６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。
【００２２】
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１９の約９５℃の冷媒液と熱交換する。
【００２３】
冷媒管１９の下流部分には流路抵抗となる流量制御弁２９が設置されて冷媒の流速を下げているので、低温再生器３内で中間吸収液に放熱して凝縮し、冷媒管１９に吐出した気液２相流の冷媒は冷媒熱回収器１１に至るまでに液相のみになり、冷媒熱回収器１１における冷媒と稀吸収液との熱交換効率が改善される。
【００２４】
しかも、温度センサ３２が検出する冷媒熱交換器１１で熱交換した後の冷媒の温度が、例えば温度センサ３１が検出する冷媒熱交換器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、流量制御弁２９の開度が制御器３３により制御され、吸収器７から高温再生器１に送る稀吸収液は加熱され、低温再生器３から凝縮器４に送る冷媒は冷却される。
【００２５】
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２７に流入する。
【００２６】
さらに、第２の排ガス熱回収器２７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２８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２８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２７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。
【００２７】
しかも、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２７を迂回して吸収液管１４に流れるまで、流量制御弁２８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２５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。
【００２８】
第２の排ガス熱回収器２７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２７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２６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１３５℃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で凝縮して凝縮器４に冷媒管１９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２４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。
【００３０】
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２４内を流れる冷却水で冷却する必要はない。
【００３１】
そのため、冷媒管１９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１９、２０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。）。
【００３２】
また、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さらに各種の変形実施が可能である。
【００３３】
例えば、冷媒管１９の流量制御弁２９は、冷媒管１９の流路抵抗を調節する手段として設けてあるので、高価な流量制御弁２９に代えて廉価なオリフィスを設置することも可能である。
【００３４】
また、高価な流量制御弁２８に代えて、廉価な開閉弁を第２の熱回収器２７上流側の吸収液管１４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。
【００３５】
また、第２の熱回収器２７を迂回する吸収液管１４に代えて、図２に示したように、第２の熱回収器２７を迂回する排気管２５Ａを設けると共に、その排気管２５Ａとの分岐部（あるいは合流部）に流路切換弁２８Ａを設ける。あるいは、第２の熱回収器２７を経由する排気管２５に開閉弁を設けるなどして、第２の熱回収器２７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、切替を制御をしてもよい。
【００３６】
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２４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２３Ａ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）２３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。
【００３７】
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。
【００３８】
【発明の効果】
以上説明したように本発明によれば、冷媒熱回収器で稀吸収液に放熱した冷媒を凝縮器に導入する冷媒管に流路抵抗を付与する手段が設置されているので、冷媒管を流れる冷媒の流速が低下し、低温再生器内で中間吸収液に放熱して凝縮し、冷媒管に吐出した気液２相流の冷媒は冷媒熱回収器に至るまでに液相のみになり、冷媒熱回収器における冷媒と稀吸収液との熱交換効率が改善される。
【００４０】
また、冷媒管に設けた流路抵抗を付与する手段が流量制御弁であり、この流量制御弁の下流側に温度センサを設けたので、冷媒熱回収器を吐出した冷媒の温度が、稀吸収液の熱交換前温度＋所定温度α（但し、α＞０）となるように流量制御弁を介して冷媒の流路抵抗を制御することができ、これにより冷媒が保有する熱を吸収器から高温再生器に送っている稀吸収液により確実に回収して、凝縮器で放熱する冷媒の保有熱を下げることが可能である。
【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】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
１９〜２１冷媒管
２２冷媒ポンプ
２３冷水管
２４冷却水管
２５排気管
２６第１の排ガス熱回収器
２７第２の排ガス熱回収器
２８流量制御弁
２８Ａ切替弁
２９流量制御弁
３０〜３２温度センサ
３３制御器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an absorption refrigerator having excellent thermal efficiency.
[0002]
[Prior art]
As shown in FIG. 3, 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 absorbent liquid pipe 12. Sequentially sent to the first exhaust gas heat recovery unit 26 and the second exhaust gas heat recovery unit 27 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 27, and the high Heated by the hot heat exchanger 10 and the first exhaust gas heat exchanger 26 respectively, rises to around 135 ° C. and flows into the high temperature regenerator 1, so that the fuel consumed by the gas burner 2 can be saved.
[0004]
Note that 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 by increasing the opening of the flow control valve 28. The heat recovery from the exhaust gas in the second exhaust gas heat recovery unit 27 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]
However, in the above-described conventional absorption refrigerator, the flow rate control valve 28 is provided in the absorption liquid pipe 14 that bypasses the second exhaust gas heat recovery device 27. Therefore, even if the flow rate control valve 28 is fully opened, the absorption liquid pipe The amount of the rare absorbent flowing through the second exhaust gas heat recovery unit 27 through 14 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. The exhaust pipe could be corroded.
[0007]
[Problems to be solved by the invention]
In addition, most of the heat held by the exhaust gas from the gas burner has been recovered, and if more heat is recovered from the exhaust gas, the temperature of the exhaust gas will be below the steam open-air 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 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 part of the rare absorbent discharged from the absorber dissipates heat from the low-temperature regenerator and the refrigerant heat recovery unit that bypasses the low-temperature heat exchanger and exchanges heat, and the refrigerant heat recovery unit dissipates heat to the rare absorption liquid. The refrigerant pipe that introduces the refrigerant into the condenser is provided with a flow rate control valve that provides flow resistance, the temperature sensor that detects the temperature of the refrigerant is provided downstream of the flow rate control valve, and the refrigerant that has discharged the refrigerant heat recovery unit The absorption flow refrigeration is characterized in that the flow path resistance of the refrigerant is controlled through a flow control valve so that the temperature of the refrigerant becomes a pre-heat exchange temperature of the rare absorbent + a predetermined temperature α (where α> 0) The machine is provided.
[0011]
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.
[0012]
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 device, 12 to 16 are absorption liquid pipes, 17 and 18 are absorption liquid pumps, 19 to 21 are refrigerant pipes, 22 are refrigerant pumps, 23 are cold water pipes, and 24 is cooling The water pipe, 25 is an exhaust pipe through which the exhaust gas from the gas burner 2 passes, 26 is a first exhaust gas heat recovery device, 27 is a second exhaust gas heat recovery device, and 28 is a second downstream of the branching portion with the absorbing liquid tube 14. A flow rate control valve 29 provided in the absorption liquid pipe 12 upstream of the exhaust gas heat recovery device 27 of A flow rate control valve provided on the downstream side of the refrigerant heat recovery unit 11 of the medium pipe 19, a temperature sensor 30 provided in the downstream part of the exhaust pipe 25 to detect the temperature of the exhaust gas, and 31 an upstream part of the absorption liquid pipe 12 , A temperature sensor 32 for detecting the temperature of the rarely absorbed liquid before heat exchange, provided in the downstream portion of the refrigerant pipe 19, of the refrigerant that has dissipated heat by exchanging heat with the rarely absorbed liquid in the refrigerant heat recovery unit 11. A temperature sensor 33 for detecting the temperature controls the opening degree of the flow control valve 28 so that the temperature sensor 30 continuously detects a predetermined temperature, for example, 100 ° C., and the temperature detected by the temperature sensor 32 is the temperature sensor 31. Is a controller for controlling the flow path resistance of the refrigerant pipe 19 by adjusting the opening degree of the flow control valve 29 so that the detected temperature + the predetermined temperature α (where α> 0).
[0013]
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.
[0014]
The high-temperature refrigerant vapor generated in the high-temperature regenerator 1 passes through the upstream portion of the refrigerant pipe 19 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 to dissipate heat, and enters the condenser 4 through the downstream portion of the refrigerant pipe 19 in which the refrigerant heat recovery unit 11 is interposed.
[0015]
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 24 to be condensed and liquefied, and is condensed and supplied from the refrigerant pipe 19. The refrigerant enters the evaporator 6 through the refrigerant pipe 20 together with the refrigerant.
[0016]
The refrigerant liquid accumulated at the bottom of the evaporator 6 is sprayed by the refrigerant pump 22 interposed in the refrigerant pipe 21 on the heat transfer pipe 23 </ b> A connected to the cold water pipe 23, and water and heat supplied through the cold water pipe 23. The water which exchanges and evaporates and flows through the inside of the heat transfer tube 23A is cooled.
[0017]
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 18 and is absorbed by the concentrated absorption liquid sprayed from above.
[0018]
Then, the absorption liquid whose concentration has been reduced by absorbing the refrigerant by the absorber 7, that is, the rare absorption liquid, is returned to the high-temperature regenerator 1 by the operation of the absorption liquid pump 17.
[0019]
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 23A piped inside the evaporator 6 becomes an unillustrated air conditioning load via the cold water pipe 23. Since it can be circulated, cooling operation such as cooling can be performed.
[0020]
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 pump 17 passes through the low-temperature heat exchanger 9 interposed in the absorbent liquid 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.
[0021]
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 27 is controlled by a flow control valve 28 interposed in the absorption liquid pipe 12, and the high temperature heat exchanger 10. And the first exhaust gas heat recovery unit 26 is supplied with the entire amount of the diluted absorbent returned from the absorber 7 to the high-temperature regenerator 1 and heated by each.
[0022]
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 between the absorption liquid and the low-temperature heat exchanger 9, and the remainder is condensed with the low-temperature regenerator 3 and heat-exchanged with the refrigerant liquid at about 95 ° C. in the refrigerant pipe 19 flowing into the condenser 4.
[0023]
Since a flow rate control valve 29 serving as a flow path resistance is installed in the downstream portion of the refrigerant pipe 19 to reduce the flow velocity of the refrigerant, the heat is dissipated and condensed in the intermediate absorbent in the low temperature regenerator 3, The discharged refrigerant in the gas-liquid two-phase flow is only in the liquid phase before reaching the refrigerant heat recovery device 11, and the heat exchange efficiency between the refrigerant and the rare absorbent in the refrigerant heat recovery device 11 is improved.
[0024]
And the temperature of the refrigerant | coolant after heat-exchanged with the refrigerant | coolant heat exchanger 11 which the temperature sensor 32 detects is the temperature of the rare absorption liquid before heat exchange with the refrigerant | coolant heat exchanger 11 which the temperature sensor 31 detects + predetermined temperature, for example For example, the opening degree of the flow control valve 29 is controlled by the controller 33 so that the temperature becomes higher by 5 ° C., and the rare absorbent sent from the absorber 7 to the high temperature regenerator 1 is heated and condensed from the low temperature regenerator 3. The refrigerant sent to the vessel 4 is cooled.
[0025]
Then, the rare absorption liquid heated and exchanged in the low-temperature heat exchanger 9 and the refrigerant heat recovery apparatus 11 is joined, and flows into the second exhaust gas heat recovery apparatus 27 as, for example, a rare absorption liquid at around 80 ° C. To do.
[0026]
Further, the flow rate of the rare absorbent flowing into the second exhaust gas heat recovery unit 27 is controlled and controlled by the controller 33 with the opening degree of the flow rate control valve 28 interposed in the absorbent liquid pipe 12. For example, the controller 33 increases the opening degree of the flow control valve 28 when the temperature sensor 30 detects a temperature higher than a predetermined temperature of 100 ° C., and the rare absorbent liquid returned from the absorber 7 to the high-temperature regenerator 1. Since more is supplied to the second heat recovery unit 27 to promote the recovery of the heat held in the exhaust gas, the thermal efficiency is improved and the fuel consumption of the gas burner 2 is suppressed.
[0027]
Moreover, when the temperature sensor 30 detects a temperature lower than 100 ° C., the flow rate control valve 28 is set to the maximum until the entire amount of the rare absorbent flows to the absorbent liquid pipe 14 bypassing the second exhaust gas heat recovery device 27. 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 25 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.
[0028]
The rare absorption liquid heated via the second exhaust gas heat recovery device 27 and the rare absorption liquid which does not pass through the second exhaust gas heat recovery device 27 and thus has not been heated are joined together to form a high temperature heat exchanger. 10 and the first exhaust gas heat recovery unit 26, the intermediate absorption liquid flowing from the high temperature regenerator 1 to the low temperature regenerator 3 through the absorption liquid pipe 15, and about 200 ° C. discharged from the gas burner 2. Since it exchanges heat with the exhaust gas and becomes a rare absorbent at about 135 ° C. and flows into the high-temperature regenerator 1, 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 downstream portion of the refrigerant pipe 19 is heat-exchanged with the rare absorbing liquid at 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 24 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.
[0030]
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 in the cooling water pipe 24.
[0031]
Therefore, the downstream side of the refrigerant pipe 19 is connected to the evaporator 6 so that the condensed refrigerant can flow into the evaporator 6 instead of the condenser 4, so that the pipe length can be shortened and the piping configuration can be simplified. 1 (in FIG. 1, the shortest portions of the refrigerant pipes 19 and 20 on the drawing are connected by phantom lines. However, in an actual apparatus, the high temperature cylinder 5 is located above, and the low temperature cylinder 8 and the refrigerant heat recovery unit 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.)
[0032]
Further, since the present invention is not limited to the above-described embodiments, various modifications can be made without departing from the spirit described in the claims.
[0033]
For example, since the flow rate control valve 29 of the refrigerant pipe 19 is provided as a means for adjusting the flow path resistance of the refrigerant pipe 19, it is possible to install an inexpensive orifice instead of the expensive flow rate control valve 29.
[0034]
Further, instead of the expensive flow rate control valve 28, an inexpensive on-off valve is installed in the absorption liquid pipe 14 upstream of the second heat recovery device 27, or an inexpensive switching valve is provided at the branch portion of the absorption liquid pipes 12, 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.
[0035]
Further, in place of the absorption liquid pipe 14 that bypasses the second heat recovery device 27, as shown in FIG. 2, an exhaust pipe 25A that bypasses the second heat recovery device 27 is provided, and the exhaust pipe 25A The flow path switching valve 28A is provided at the branching section (or merging section). Alternatively, the temperature of the exhaust gas flowing through the second heat recovery device 27 and exchanging heat with the rare absorbent is higher than a predetermined 100 ° C. by providing an open / close valve in the exhaust pipe 25 passing through the second heat recovery device 27. The controller 33 may control opening / closing and switching of the valve so as not to decrease.
[0036]
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 cylinder 8 so that it can be directly supplied to the cooling water pipe 24, the diluted absorbent is heated by the gas burner 2 without flowing cooling water, and is heated to, for example, about 55 ° C. by the heat transfer pipe 23 A of the evaporator 6. The water may be circulated and supplied to a load via a cold water pipe (preferably called a hot water pipe when hot water circulates) 23 so that heating operation such as heating can be performed.
[0037]
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.
[0038]
【The invention's effect】
As described above, according to the present invention, since the refrigerant pipe that introduces into the condenser the refrigerant that has radiated the rare absorbing liquid in the refrigerant heat recovery unit is provided to the flow path resistance, it flows through the refrigerant pipe. The flow rate of the refrigerant is reduced, and the refrigerant in the gas-liquid two-phase flow discharged to the refrigerant pipe becomes only the liquid phase before reaching the refrigerant heat recovery unit. The heat exchange efficiency between the refrigerant and the rare absorbent in the heat recovery device is improved.
[0040]
In addition, the means for imparting flow resistance provided in the refrigerant pipe is a flow control valve, and a temperature sensor is provided downstream of the flow control valve, so that the temperature of the refrigerant discharged from the refrigerant heat recovery device is rarely absorbed. The flow path resistance of the refrigerant can be controlled via the flow rate control valve so that the temperature before the heat exchange of the liquid + the predetermined temperature α (where α> 0) , whereby the heat held by the refrigerant is transferred from the absorber. It is possible to reliably recover the rare absorbent that is sent to the high-temperature regenerator, and to reduce the retained heat of the refrigerant that dissipates heat in the condenser.
[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 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 pumps 19 to 21 Refrigerant pipe 22 Refrigerant pump 23 Cold water pipe 24 Cooling water pipe 25 Exhaust pipe 26 First exhaust gas heat recovery device 27 Second exhaust gas heat recovery device 28 Flow rate control valve 28A Switching valve 29 Flow rate control valves 30 to 32 Temperature Sensor 33 Controller

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 part of the rare absorbent discharged from the absorber dissipates heat from the low-temperature regenerator and the refrigerant heat recovery unit that bypasses the low-temperature heat exchanger and exchanges heat, and the refrigerant heat recovery unit dissipates heat to the rare absorption liquid. The refrigerant pipe that introduces the refrigerant into the condenser is provided with a flow rate control valve that provides flow resistance, the temperature sensor that detects the temperature of the refrigerant is provided downstream of the flow rate control valve, and the refrigerant that has discharged the refrigerant heat recovery unit The absorption flow refrigeration is characterized in that the flow path resistance of the refrigerant is controlled through a flow control valve so that the temperature of the refrigerant becomes a pre-heat exchange temperature of the rare absorbent + a predetermined temperature α (where α> 0) Machine.