JP2900608B2 - Absorption refrigerator - Google Patents

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

技術分野 本発明は、主に冷媒に水を、吸収溶液に臭化リチウム
水溶液をそれぞれ用い、構成機器として、蒸発器、吸収
器、発生器及び凝縮器を備える吸収式冷凍機に関する。 背景技術 従来、特公平３−20671号公報に開示され、且つ図７
に示すように、冷媒液の散布器１及び冷媒ポンプＰ並び
に冷水管Ｗをもつ蒸発器Ａと、該蒸発器Ａと同一容器Ｕ
内にエリミネータＭを挟んで設けられ、濃溶液の散布器
Ｓ及び冷却水配管Ｒをもつ吸収器Ｂと、該吸収器Ｂと溶
液ポンプＧ並びに熱交換器LHを介して接続され、加熱管
から成る加熱源Ｖにより吸収器Ｂで多量に冷媒を含んだ
稀溶液から冷媒を発生させる発生器CDと、該発生器CDと
同一容器Ｔ内に設けられ、吸収器Ｂの冷却水配管Ｒの後
段に連続して設ける冷却水配管Ｊにより発生器CDで発生
した冷媒蒸気を凝縮させる凝縮器Ｅとを備えている。こ
うして、蒸発器Ａにおいて、散布する冷媒の蒸発によ
り、冷水管Ｗに冷房負荷に供給する冷水を取り出すよう
にしている。 また、冷水管Ｗの出口には冷水出口温度検出器Ｚを設
けており、該検出器Ｚで検出する冷水出口温度すなわち
冷房負荷に基づいて加熱源Ｖの制御弁Ｎを開度制御し、
冷房負荷に応じて発生器CDの加熱量を調節している。ま
た、更に凝縮器Ｅの冷却水の出口温度を検出する冷却水
出口温度検出器OSと凝縮器Ｅの凝縮温度を検出する凝縮
温度検出器ESとから成り、発生器CDの出口の溶液濃度を
検出する濃度検出手段を設け、この温度検出手段で検出
する濃溶液濃度が設定値を越えたとき、制御装置Ｆによ
り加熱源Ｖの制御弁Ｎを絞り、発生器CDの加熱量を減ら
して溶液の濃度を薄くし、機内で溶液の結晶が生じるの
を防止するようしている。 一万、機内の結晶を防止する対策を講じた別例として
特開平２−75865号公報に開示されたものがあり、この
ものは図８に示すように冷却水配管Ｒの入口に冷却水入
口温度検出手段Ｘを設けて、その検出値に基づいて発生
器の加熱量を制限することとしている。即ち、この図８
のものは、発生器が、ガスバーナから成る加熱源Ｖをも
つ高温発生器Ｃと、この高温発生器Ｃで発生する冷媒蒸
気を流す加熱器Ｋをもつ低温発生器Ｄとから成り、熱交
換器が高温熱交換器Ｈと低温熱交換器Ｌとから成る二重
効用形のものであり、結晶危険状態を冷却水入口温度に
基づいて察知し、制御対象となる高温発生器Ｃの加熱源
Ｖを制御することとしたものである。具体的には、図９
に示すように、検出冷却水温の値に応じて低温発生器Ｄ
で再生する濃溶液の再生温度を設定し、低温発生器Ｄの
出口に介装する濃溶液温度検出器Ｙで検出する実際の濃
溶液温度がその発生器再生温度の設定値を越える場合に
は、冷水出口温度検出器Ｚの検出値に関係なく、結晶防
止制御に移行して制御弁Ｎを強制的に絞り、高温発生器
Ｃの加熱量を減らして溶液の濃度を薄くし、機内で溶液
の結晶が生じるのを防止するようにしている。 しかし、図７に示したものでは、通常運転時は冷水出
口温度つまり冷房負荷に基づいて加熱量を制御している
が、結晶危険域にあるか否かの判定を、濃溶液の検出濃
度がある設定値を越えるか否かによって峻別しているた
め、冷房負荷の大きさが全く考慮されておらず、100％
負荷時であろうが、80％負荷時であろうが、40％負荷時
であろうが、一律の制御となってしまう。しかるに、例
えば80％負荷時ならば、100％負荷時に比べて小さな負
荷に見合う冷媒蒸気を吸収器Ｂで吸収すれば足り、100
％負荷時よりも低濃度の運転となるが、それにも拘ら
ず、100％負荷時と同一の基準値で結晶の危険状態を判
定していては、相当危険な状態となってから初めてこの
危険状態が判明することとなり、迅速な結晶防止対策に
ならない問題がある。 一万、図８に示したものでも冷房負荷を考慮した結晶
危険状態を検出しているわけでなく、冷却口水入口温度
に応じて許容し得る濃溶液の再生温度を決定しているの
であって、この冷却水入口温度は冷却水配管R,Jの循環
経路に配される外付けの冷却塔の発停により大きく変動
するから、制御として適切でない。すなわち、外付けの
冷却塔が停止から起動に移行し、冷却水温度が急激に下
がった場合には、この急激に低下した冷却水温度に即応
して発生器再生温度が低く設定される一方で、実際の濃
溶液の温度低下は遅延して起こることから、見掛け上、
濃溶液温度が再生温度の設定値を越えてしまい、不用意
に加熱源Ｖの加熱量を制限してしまう問題がある。 以上のように従来のものは、いずれも冷房負荷の大き
さを考慮することなく結晶防止制御を行っているため、
負荷に応じた迅速な制御が行えないと共に、無用な結晶
防止制御を行う問題があり、冷房負荷に応じた適切な結
晶防止制御及び最適なサイクル制御が行えていない問題
がある。 本発明の主目的は、冷房負荷に応じた適切な結晶防止
制御を行うことにより、負荷に見合った迅速な制御を実
現すると共に、冷却水温の急激な低下等による無用な結
晶防止制御を防止でき、冷凍機の運転サイクルを最適に
維持しながら、結晶の発生を未然に防止して装置の安全
が図れる吸収式冷凍機を提供する点にある。 発明の開示 そこで、上記主目的を達成するために、図１に示すよ
うに、冷媒を蒸発させて冷房負荷に供給する冷熱を取り
出す蒸発器１、該蒸発器１で蒸発した冷媒を溶液に吸収
させる吸収器２、該吸収器２で冷媒を吸収した溶液から
冷媒を発生させて濃縮した濃溶液を前記吸収器２に供給
する発生器3,4及び該発生器3,4で発生した冷媒を凝縮さ
せて液冷媒を前記蒸発器１に供給する凝縮器５を備え、
負荷検出手段６で検出する検出冷房負荷の大小に応じて
発生器３に具備する加熱源31の加熱量を増減制御する加
熱量制御手段32を設けた吸収式冷凍機において、濃溶液
の濃度を検出する濃度検出手段７と、検出冷房負荷が小
さいとき濃溶液の最高許容限界濃度を低く、検出冷房負
荷が大きいとき同限界濃度を高く定める濃溶液の限界濃
度設定手段８と、濃溶液の検出濃度が限界濃度を越える
こととなるとき前記加熱量制御手段32に加熱量の制限指
令を与える加熱量制限手段９とを設けた。 これにより、限界濃度設定手段８により、検出冷房負
荷に応じて濃溶液の最高許容限界濃度が設定され、濃度
検出手段７による濃溶液の検出濃度がその限界濃度を越
えない場合には、検出冷房負荷に応じた加熱量の制御が
なされ、濃溶液の検拙濃度がその限界濃度を越えること
となる場合には、加熱量制限手段９により、本来の冷房
負荷に基づく加熱量に対し制限した加熱量に制御され
る。こうして、濃溶液の検出濃度が限界濃度を越えるこ
ととなる場合は、加熱量が制限されて、溶液濃度が低下
するから、結晶の発生を未然に防止できる。この制御に
おいては、加熱量を制限する基準となる限界濃度は、冷
房負荷に基づいて設定しており、その負荷に応じた迅速
な結晶防止制御が行えると共に、冷却水温の急激な低下
により本来的に結晶防止制御が不要な場合には加熱量を
制限することもなく、冷凍機の運転サイクルをできるだ
け最適に維持できながら、結晶の発生を未然に防止する
ことができるのである。 すなわち、本来的に安定した正常な運転であれば、冷
房負荷に対応して系内の濃度、温度、圧力が決まってく
る。これらの値は設計上、予め判っており、図６のサイ
クル線に描いたような状態になる。ここに、冷房負荷が
大きい程、各機器の状態を示すサイクル線は右にあり、
低温再生器の溶液濃度が大きくなる。結晶防止のため、
結晶線に基づいて低温再生器の限界濃度を定めることが
できるが、最も濃度が高いのが100％冷房負荷のときで
あるから、冷房負荷を考慮しなければ、100％負荷のと
きの濃度よりも低い限界濃度を定めることができない。
そこで、冷房負荷に対応した低温再生器の濃溶液濃度よ
りも多少大きい値（0.5％程）を限界濃度とすることに
より、100％負荷時の結晶線の近傍に至るよりも前に異
常と判断できるので、迅速に結晶防止の対処ができる。 例えば、図６のサイクル線に沿った運転をする冷凍機
において、冷房負荷を考慮しないで、結晶線に基づいて
限界濃度を定めるとすると、63.5％以下の濃度を限界濃
度とすることはできず、63.5％以下の濃度で異常と判断
できない。 しかし、本発明によれば、40％負荷の場合の限界濃度
である59％（正常なサイクル線は58.5％）になったとき
に異常、すなわち、結晶化する怖れがあると判断でき、
加熱量を制限することにより、迅速に結晶防止の対処が
できるのである。 ところで、以上の場合において、冷房負荷に基づく加
熱量制御からできるだけ大きく逸脱しない範囲内で結晶
発生の防止を図るため、加熱量制限手段９を、所定時間
毎に加熱量を一ステップずつ段階的に制限していくステ
ップ制限手段90で構成するのが好ましく、これによれ
ば、ステップ制限手段90により、加熱量を所定時間毎に
一ステップずつ段階的に制限していくから、結晶防止制
御に移行した場合に、冷房負荷に基づく加熱量制御から
できるだけ大きく逸脱しない範囲内で結晶の発生を防止
できる。 更に、加熱量の制限でも結晶の回避がし難い場合に対
処するため、加熱量制限手段９による制御で検出濃度が
限界濃度を下回らないとき、運転を非常停止させる非常
停止手段10を備えている構成にするのが好ましく、これ
によれば、非常停止状態10により、加熱量の制限制御で
も結晶を可避できない場合、運転が非常停止されるた
め、結晶の成長により回復困難な不良に陥る事態を未然
に防止でき、非常の安全が図れる。 この非常停止手段10の発動時、警報を発する警報手段
900を設けるのが更に好ましく、これによれば、運転の
非常停止時に警報手段900から警報が発せられるため、
装置の異常をオペレータ等に知らせることができる。 ところで、以上の構成で、冷却水温の急激な低下によ
る無用な結晶防止制御を確実に回避するためには、吸収
器２及び凝縮器５に供給する冷却水の温度を検出する冷
却水温検出手段51と、検出冷却水温の単位時間あたりの
変化値を求める変化値演算手段52と、濃溶液の検出濃度
が限界濃度を超えるが冷却水温の変化値が所定値を上回
る場合には所定時間だけ加熱量制限手段９による制御を
待機させる待機手段91と、待機時間経過後の検出濃度が
限界濃度をなおも越える場合には加熱量制限手段９によ
る制御に移行させる遅延起動手段92とを備えている構成
にするのが好ましい。この構成によれば、冷却塔の発停
により冷却水温が急激に低下し、この冷却水温の単位時
間あたりの変化値が所定値を上回る湯合には、濃溶液の
検出濃度が限界濃度を越えていても、待機手段91により
所定時間だけ加熱量制限手段９による制御が待機され、
待機時間経過後の検出濃度が限界濃度をなおも越える場
合に限って遅延起動手段92により加熱量制限手段９によ
る制御に移行させるから、冷却水温の急激な低下による
無用な結晶防止制御を確実に回避することができる。 すなわち、吸収式冷凍機は、冷却水温が下がると、冷
凍能力が向上し、冷却水温が上がると冷凍能力が低下す
る。設計上は定格負荷（100％）で冷却水入口温度を通
常32℃としているので、冷房負荷100％のとき、これよ
りも冷却水入口温度が高い状態、すなわち冷却塔の発停
によるものや、冷却塔の能力不足のとき予定している冷
凍能力を発揮する事ができない。また、逆にインプット
量が仮に燃焼量100％の状態で冷却水人口温度が32℃よ
り低い場合は、吸収器２における伝熱量が増し吸収性能
が向上するため、100％以上の冷凍能力を発揮し、これ
に伴って濃溶液の濃度も薄くなる。 次に冷却水入口温度が例えば29℃から26℃に急激に下
がった場合について検討する。冷却水入口温度が29℃で
安定運転されている機械の冷房負荷が80％のとき、その
時の運転濃液濃度を図２に示すように61.5％とすると、
この状態から急激に冷却水入口温度が26℃に下がると冷
凍能力が上がる為、冷房負荷を示す冷水出口温度が下が
り、冷房負荷が減少したこととなる。この減少した時の
冷房負荷を60％とすると、対応する限界濃液濃度が60％
となり、冷却水温度が29℃の時の濃度が61％の為、この
ままでは結晶防止制御域に入り、結晶防止制御を行って
しまう。しかし、現実の機械では冷却水温度が下がると
濃溶液濃度は時間遅れを伴って下がる為、冷却水温が急
激に下がった場合は結晶防止制御を直ちには行う必要が
ない。 因って濃溶液濃度が冷房負荷に対する限界値を越えて
も、冷却水入口温度が急激に下がった場合には、所定時
間経過後になおも濃溶液濃度が限界値を越える場合には
結晶防止制御を行い、所定時間経過後に濃溶液濃度が低
くなった場合には結晶防止運転を行なわないこととし
て、不必要な結晶防止制御を行なわないものとしたので
ある。 更に、以上の場合において、濃度検出手段７が、吸収
器２及び凝縮器５に供給する冷却水の入口温度を検出す
る冷却水温検出手段51と、発生器４で濃縮した濃溶液温
度を検出する濃溶液温度検出手段71とで溶液濃度を決定
するものとするが好ましい。この構成では、溶液濃度を
冷却水入口温度と発生器４で濃縮した濃溶液温度から濃
溶液の濃度を決定することとしており、系内が安定した
正常状態であれば発生器４の濃溶液濃度を正しく検出す
ることができる。例えば、凝縮器５の冷媒液温度は、安
定した正常状態であれば、冷却水入口温度よりも一定温
度（６℃程）だけ高いので、冷却水入口温度が29℃のと
き、凝縮器の冷媒液温度は35℃となる。このとき図６に
示すように、発生器４の濃溶液温度が85℃であれば（80
％負荷時）凝縮器５の冷媒液温度35℃の線と発生器４の
濃溶液温度85℃の線との交点に該当する横軸の示す値が
発生器４の濃溶液濃度であるので、61.5％と決定でき
る。 ところで、発生器４の濃溶液温度が85℃のままで冷却
水温度が29℃から下がって26℃になったとき、凝縮器５
の溶液温度は32℃になる。この値から、図６に基づいて
発生器４の濃溶液濃度を62.4％と決定できる。 この濃度は冷却水温度29℃のときの発生器４の濃溶液
濃度61.5％より0.9％高い温度を示す。 しかし、冷却水が急激に下がった場合はその影響が発
生器４にまで及び系内が安定するまでには、相当の時間
がかかる。冷凍機の大きさによって、この時間は異なる
が例えば３分かかるものもある。 従って、冷却水の温度が急激に下がった直後の発生器
４の濃溶液の実際の濃度は、下がる前と同じくらい、つ
まり上記の例では61.5％だが、濃度検出手段７の示す濃
度は実際の濃度よりも高い値、つまり62.4％を示し、正
しい値を示していない。 因って、冷却水の温度が急激に下がったときは発生器
４の濃溶液に影響が及ぶまでの時間が経過するまで待っ
てその後の加熱量を制限する必要性は濃度検出手段７の
示す濃度で判断することとし、冷却水温度の低下が一時
的であって、すぐにもとに戻る場合に、不必要な結晶防
止運転を行わないものとしたのである。 ところで、図１のものでは、冷却水温の急激な低下に
よる無用な結晶防止制御を確実に回避するために冷却水
温検出手段51の検出値の変化を看ることとしたが、この
他に、図５に示すように、凝縮器５の冷媒温度を検出す
る冷媒温度検出手段510と、検出冷媒温度の単位時間あ
たりの変化値を求める変化値演算手段520と、濃溶液の
検出濃度が限界濃度を超えるが冷媒温度の変化値が所定
値を上回る場合には所定時間だけ加熱量制限手段９によ
る制御を待機させる待機手段910と、待機時間経過後の
検出濃度が限界濃度をなおも越える場合には加熱量制限
手段９による制御に移行させる遅延起動手段920とを設
けてもよい。 これによれば、冷却水温の急激な低下があった場合、
冷却水が供給される凝縮器５の冷却温度もこれにほぼ即
応して低下するため、凝縮器５での冷媒温度の単位時間
あたりの変化値が所定値を上回る場合には、濃溶液の検
出濃度が限界濃度を越えていても、待機手段910により
所定時間だけ加熱量制限手段９による制御が待機され、
待機時間経過後の検出濃度が限界濃度をなおも越える場
合に限って遅延起動手段920により加熱量制限手段９に
よる制御に移行させるから、冷却水温の急激な低下によ
る無用な結晶防止制御を確実に回避することができる。 図面の簡単な説明TECHNICAL FIELD The present invention relates to an absorption refrigerator including an evaporator, an absorber, a generator, and a condenser as constituent devices, mainly using water as a refrigerant and a lithium bromide aqueous solution as an absorption solution. BACKGROUND ART Conventionally, it is disclosed in Japanese Patent Publication No. Hei 3-20671 and FIG.
As shown in FIG. 1, an evaporator A having a refrigerant liquid sprayer 1, a refrigerant pump P, and a cold water pipe W, and a container U
And an absorber B having a sparger S for concentrated solution and a cooling water pipe R, which is connected to the absorber B via a solution pump G and a heat exchanger LH. A generator CD for generating a refrigerant from a dilute solution containing a large amount of refrigerant in the absorber B by the heating source V, and a cooling water pipe R of the absorber B provided in the same vessel T as the generator CD. And a condenser E for condensing the refrigerant vapor generated in the generator CD by a cooling water pipe J provided continuously to the cooling water pipe J. Thus, in the evaporator A, the cold water to be supplied to the cooling load to the cold water pipe W is taken out by the evaporation of the sprayed refrigerant. Further, a chilled water outlet temperature detector Z is provided at the outlet of the chilled water pipe W, and the opening of the control valve N of the heating source V is controlled based on the chilled water outlet temperature detected by the detector Z, that is, the cooling load.
The heating amount of the generator CD is adjusted according to the cooling load. The cooling water outlet temperature detector OS for detecting the outlet temperature of the cooling water of the condenser E and the condensing temperature detector ES for detecting the condensing temperature of the condenser E are provided. When the concentration of the concentrated solution detected by the temperature detecting means exceeds a set value, the control valve F of the heating source V is throttled by the control device F to reduce the amount of heating of the generator CD, Is reduced to prevent the formation of solution crystals in the apparatus. Another example of taking measures to prevent 10,000 crystals in the machine is disclosed in Japanese Patent Application Laid-Open No. 2-75865, which discloses a cooling water inlet R at the inlet of a cooling water pipe R as shown in FIG. A temperature detecting means X is provided, and the heating amount of the generator is limited based on the detected value. That is, FIG.
The generator comprises a high-temperature generator C having a heating source V composed of a gas burner, and a low-temperature generator D having a heater K through which refrigerant vapor generated by the high-temperature generator C flows. Is a double-effect type comprising a high-temperature heat exchanger H and a low-temperature heat exchanger L, detects a danger state of crystallization based on the cooling water inlet temperature, and controls the heating source V of the high-temperature generator C to be controlled. Is to be controlled. Specifically, FIG.
, The low-temperature generator D according to the value of the detected cooling water temperature
If the actual concentrated solution temperature detected by the concentrated solution temperature detector Y interposed at the outlet of the low-temperature generator D exceeds the set value of the generator regeneration temperature, Regardless of the detection value of the chilled water outlet temperature detector Z, the process shifts to the crystallization prevention control, the control valve N is forcibly throttled, the heating amount of the high temperature generator C is reduced to reduce the concentration of the solution, Is prevented from being generated. However, in the example shown in FIG. 7, during normal operation, the heating amount is controlled based on the chilled water outlet temperature, that is, the cooling load. Because it is distinguished by whether it exceeds a certain set value, the size of the cooling load is not considered at all and 100%
Regardless of whether it is under load, 80% load, or 40% load, the control is uniform. However, for example, at 80% load, it is sufficient to absorb the refrigerant vapor corresponding to a smaller load with the absorber B than at 100% load.
However, if the danger state of the crystal is judged based on the same reference value as at the time of 100% load, this danger occurs only after the dangerous state is reached. The state becomes clear, and there is a problem that it is not possible to take a quick crystallization prevention measure. 10,000 does not necessarily detect the danger state of the crystal in consideration of the cooling load, but determines the allowable regeneration temperature of the concentrated solution according to the cooling water inlet temperature. However, the cooling water inlet temperature fluctuates greatly due to the start and stop of an external cooling tower arranged in the circulation path of the cooling water pipes R and J, and is not appropriate as control. In other words, when the external cooling tower shifts from stop to start and the cooling water temperature drops sharply, the generator regeneration temperature is set to be low in response to the suddenly lowered cooling water temperature. Since the temperature drop of the actual concentrated solution occurs with a delay, apparently,
There is a problem that the temperature of the concentrated solution exceeds the set value of the regeneration temperature and the amount of heating of the heating source V is carelessly limited. As described above, the conventional ones perform crystallization prevention control without considering the magnitude of the cooling load,
There is a problem that quick control cannot be performed according to the load, and unnecessary crystallization prevention control is performed. There is a problem that appropriate crystallization prevention control and optimal cycle control cannot be performed according to the cooling load. The main object of the present invention is to perform appropriate crystallization prevention control according to the cooling load, thereby realizing quick control corresponding to the load, and preventing unnecessary crystallization prevention control due to a sudden decrease in cooling water temperature and the like. Another object of the present invention is to provide an absorption refrigerator in which the generation of crystals is prevented beforehand while maintaining the optimal operation cycle of the refrigerator, and the safety of the apparatus can be improved. DISCLOSURE OF THE INVENTION Accordingly, in order to achieve the above-mentioned main object, as shown in FIG. 1, an evaporator 1 for evaporating a refrigerant and extracting cold heat to be supplied to a cooling load, absorbing the refrigerant evaporated by the evaporator 1 into a solution. An absorber 2 for generating a refrigerant from a solution in which the refrigerant is absorbed by the absorber 2, a generator 3, 4 for supplying a concentrated solution concentrated by generating the refrigerant to the absorber 2, and a refrigerant generated in the generator 3, 4 A condenser 5 for condensing and supplying a liquid refrigerant to the evaporator 1;
In the absorption type refrigerator provided with the heating amount control means 32 for increasing and decreasing the heating amount of the heating source 31 provided in the generator 3 according to the magnitude of the cooling load detected by the load detecting means 6, the concentration of the concentrated solution is A concentration detecting means 7 for detecting, a limit concentration setting means 8 for the concentrated solution which sets the maximum allowable limit concentration of the concentrated solution low when the detected cooling load is small, and sets a high limit concentration when the detected cooling load is large; The heating amount control means 32 is provided with a heating amount limitation means 9 for giving a heating amount limitation command to the heating amount control means 32 when the concentration exceeds the limit concentration. Thereby, the maximum allowable limit concentration of the concentrated solution is set by the limit concentration setting means 8 according to the detected cooling load, and if the detected concentration of the concentrated solution by the concentration detection means 7 does not exceed the limit concentration, the detected cooling is performed. The heating amount is controlled according to the load, and when the concentration of the concentrated solution exceeds the limit concentration, the heating amount is limited by the heating amount limiting means 9 to the heating amount based on the original cooling load. Controlled by the quantity. Thus, when the detected concentration of the concentrated solution exceeds the limit concentration, the amount of heating is restricted and the solution concentration is reduced, so that the generation of crystals can be prevented beforehand. In this control, the limit concentration as a reference for limiting the heating amount is set based on the cooling load, and the crystallization prevention control can be quickly performed according to the load, and the cooling water temperature is naturally lowered due to the sudden drop. In the case where the crystallization prevention control is unnecessary, the amount of heating is not limited, and the generation of crystals can be prevented beforehand while maintaining the operation cycle of the refrigerator as optimal as possible. That is, if the operation is inherently stable and normal, the concentration, temperature, and pressure in the system are determined according to the cooling load. These values are known in advance by design, and are in a state as depicted by the cycle line in FIG. Here, as the cooling load increases, the cycle line indicating the state of each device is on the right,
The solution concentration in the low-temperature regenerator increases. To prevent crystallization
The limit concentration of the low-temperature regenerator can be determined based on the crystal line. However, the concentration is the highest when the cooling load is 100%. Nor can it set a low limiting concentration.
Therefore, by setting the threshold concentration to a value slightly larger than the concentrated solution concentration of the low-temperature regenerator corresponding to the cooling load (about 0.5%), it is judged that an abnormality occurs before reaching the vicinity of the crystal line at 100% load. As a result, crystallization can be quickly prevented. For example, in a refrigerator operating along the cycle line of FIG. 6, if the limit concentration is determined based on the crystal line without considering the cooling load, the concentration of 63.5% or less cannot be set as the limit concentration. , 63.5% or less cannot be judged as abnormal. However, according to the present invention, when the concentration reaches a critical concentration of 59% (normal cycle line is 58.5%) in the case of a 40% load, it can be determined that there is a risk of abnormal, that is, crystallization,
By limiting the amount of heating, it is possible to quickly take measures to prevent crystallization. By the way, in the above case, in order to prevent the generation of crystals within a range that does not deviate as much as possible from the heating amount control based on the cooling load, the heating amount limiting means 9 is stepwisely increased by one step every predetermined time. It is preferable to use a step limiting means 90 to limit the heating amount. According to this, the heating amount is gradually limited by one step every predetermined time by the step limiting means 90. In this case, the generation of crystals can be prevented within a range that does not deviate as much as possible from the heating amount control based on the cooling load. Further, in order to cope with the case where it is difficult to avoid the crystal even with the limitation of the heating amount, an emergency stop means 10 for emergency stop of the operation when the detected concentration does not fall below the limit concentration by the control of the heating amount limitation means 9 is provided. According to this, when the crystal cannot be evacuated even with the control of the heating amount due to the emergency stop state 10, the operation is emergency stopped, and the crystal grows into a failure that is difficult to recover. Can be prevented beforehand, and very safety can be achieved. Alarm means for issuing an alarm when the emergency stop means 10 is activated
More preferably, 900 is provided. According to this, a warning is issued from the warning means 900 at the time of emergency stop of driving,
An abnormality of the apparatus can be notified to an operator or the like. By the way, in the above configuration, in order to reliably avoid unnecessary crystal prevention control due to a sudden drop in the cooling water temperature, a cooling water temperature detecting means 51 for detecting the temperature of the cooling water supplied to the absorber 2 and the condenser 5 is required. And a change value calculating means 52 for calculating a change value of the detected cooling water temperature per unit time, and a heating amount for a predetermined time when the detected concentration of the concentrated solution exceeds the limit concentration but the change value of the cooling water temperature exceeds a predetermined value. A configuration including a standby unit 91 for waiting for control by the limiting unit 9 and a delay activation unit 92 for shifting to control by the heating amount limiting unit 9 when the detected density after the standby time still exceeds the limit density. It is preferred that According to this configuration, the cooling water temperature drops rapidly due to the start and stop of the cooling tower, and when the change value of the cooling water temperature per unit time exceeds a predetermined value, the detected concentration of the concentrated solution exceeds the limit concentration. The control by the heating amount limiting means 9 waits for a predetermined time by the waiting means 91,
Only when the detected concentration after the elapse of the standby time still exceeds the limit concentration, the control is shifted to the control by the heating amount restricting means 9 by the delay starting means 92, so that the unnecessary crystal prevention control due to the rapid decrease of the cooling water temperature is ensured. Can be avoided. That is, in the absorption refrigerator, the refrigeration capacity increases as the cooling water temperature decreases, and the refrigeration capacity decreases as the cooling water temperature increases. Since the cooling water inlet temperature is normally 32 ° C at the rated load (100%) in design, when the cooling load is 100%, the cooling water inlet temperature is higher than this, that is, when the cooling tower starts and stops, When the capacity of the cooling tower is insufficient, the intended refrigeration capacity cannot be exhibited. Conversely, if the cooling water population temperature is lower than 32 ° C with the input amount being 100% combustion, the amount of heat transfer in the absorber 2 is increased and the absorption performance is improved, so that the refrigeration capacity of 100% or more is exhibited. However, the concentration of the concentrated solution decreases accordingly. Next, a case in which the cooling water inlet temperature suddenly drops from, for example, 29 ° C. to 26 ° C. will be discussed. If the cooling load of a machine that is operating stably at a cooling water inlet temperature of 29 ° C is 80% and the operating concentrated liquid concentration at that time is 61.5% as shown in Fig. 2,
When the cooling water inlet temperature suddenly drops to 26 ° C. from this state, the refrigeration capacity increases, so that the cooling water outlet temperature indicating the cooling load decreases, and the cooling load decreases. Assuming that the cooling load at the time of this decrease is 60%, the corresponding critical concentration is 60%.
Since the concentration is 61% when the temperature of the cooling water is 29 ° C., the crystal enters the crystallization prevention control area and the crystallization prevention control is performed. However, in a real machine, when the cooling water temperature decreases, the concentration of the concentrated solution decreases with a time delay. Therefore, when the cooling water temperature sharply decreases, it is not necessary to immediately perform the crystallization prevention control. Therefore, even if the concentration of the concentrated solution exceeds the limit value for the cooling load, if the cooling water inlet temperature drops rapidly, the crystallization prevention control is performed if the concentration of the concentrated solution still exceeds the limit value after the elapse of a predetermined time. Then, when the concentration of the concentrated solution becomes low after the lapse of a predetermined time, the crystallization prevention operation is not performed, and unnecessary crystallization prevention control is not performed. Further, in the above case, the concentration detecting means 7 detects the cooling water temperature detecting means 51 for detecting the inlet temperature of the cooling water supplied to the absorber 2 and the condenser 5, and the temperature of the concentrated solution concentrated by the generator 4. The concentration of the solution is preferably determined by the concentrated solution temperature detecting means 71. In this configuration, the concentration of the concentrated solution is determined from the inlet temperature of the cooling water and the temperature of the concentrated solution concentrated in the generator 4. If the inside of the system is in a stable normal state, the concentration of the concentrated solution in the generator 4 is determined. Can be detected correctly. For example, when the refrigerant liquid temperature of the condenser 5 is stable and normal, the refrigerant liquid temperature is higher than the cooling water inlet temperature by a certain temperature (about 6 ° C.). The liquid temperature becomes 35 ° C. At this time, if the temperature of the concentrated solution in the generator 4 is 85 ° C. as shown in FIG.
% Load) The value indicated by the horizontal axis corresponding to the intersection of the line of the refrigerant liquid temperature of the condenser 5 of 35 ° C. and the line of the concentrated solution temperature of the generator 4 of 85 ° C. is the concentrated solution concentration of the generator 4. 61.5% can be determined. By the way, when the cooling water temperature drops from 29 ° C. to 26 ° C. while the concentrated solution temperature of the generator 4 remains at 85 ° C., the condenser 5
Is 32 ° C. From this value, the concentrated solution concentration of the generator 4 can be determined to be 62.4% based on FIG. This concentration is 0.9% higher than the 61.5% concentrated solution concentration of the generator 4 when the cooling water temperature is 29 ° C. However, when the cooling water drops suddenly, it takes a considerable time until the influence reaches the generator 4 and the inside of the system is stabilized. This time varies depending on the size of the refrigerator, but may take, for example, three minutes. Therefore, the actual concentration of the concentrated solution of the generator 4 immediately after the temperature of the cooling water has dropped sharply is the same as that before the decrease, that is, 61.5% in the above example, but the concentration indicated by the concentration detecting means 7 is the actual concentration. The value is higher than the concentration, that is, 62.4%, which is not a correct value. Therefore, when the temperature of the cooling water drops rapidly, the concentration detecting means 7 indicates that it is necessary to wait until the time until the concentrated solution in the generator 4 is affected has elapsed and to limit the amount of heating thereafter. Judgment was made on the basis of the concentration, and when the cooling water temperature was temporarily lowered and returned to the original state immediately, unnecessary crystallization preventing operation was not performed. By the way, in FIG. 1, a change in the detection value of the cooling water temperature detecting means 51 is observed in order to reliably avoid unnecessary crystal prevention control due to a rapid decrease in the cooling water temperature. As shown in FIG. 5, a refrigerant temperature detecting means 510 for detecting the refrigerant temperature of the condenser 5, a change value calculating means 520 for obtaining a change value of the detected refrigerant temperature per unit time, Exceeding, when the change value of the refrigerant temperature exceeds the predetermined value, standby means 910 for waiting the control by the heating amount limiting means 9 for a predetermined time, and when the detected concentration after the standby time still exceeds the limit concentration, A delay activation unit 920 for shifting to control by the heating amount restriction unit 9 may be provided. According to this, if there is a sharp drop in cooling water temperature,
Since the cooling temperature of the condenser 5 to which the cooling water is supplied also decreases almost immediately, the change of the refrigerant temperature in the condenser 5 per unit time exceeds a predetermined value, the detection of the concentrated solution is performed. Even if the concentration exceeds the limit concentration, the control by the heating amount restricting means 9 waits for a predetermined time by the standby means 910,
Only when the detected concentration after the elapse of the standby time still exceeds the limit concentration, the control is shifted to the control by the heating amount limiting means 9 by the delay starting means 920, so that the unnecessary crystal prevention control due to the rapid decrease of the cooling water temperature is ensured. Can be avoided. BRIEF DESCRIPTION OF THE FIGURES

【図１】本発明に係る吸収式冷凍機の第一実施例を示す
配管図。FIG. 1 is a piping diagram showing a first embodiment of an absorption refrigerator according to the present invention.

【図２】同限界濃度設定手段の説明図。FIG. 2 is an explanatory diagram of the limit concentration setting means.

【図３】同加熱量制限の遅延制御の説明図。FIG. 3 is an explanatory diagram of delay control of the heating amount limitation.

【図４】同制御全体のフローチャート。FIG. 4 is a flowchart of the whole control.

【図５】同第二実施例を示す配管図。FIG. 5 is a piping diagram showing the second embodiment.

【図６】同作用を説明するサイクル線図。FIG. 6 is a cycle diagram illustrating the same operation.

【図７】従来の第１技術の配管図。FIG. 7 is a piping diagram of the first conventional technique.

【図８】従来の第２技術の配管図。FIG. 8 is a piping diagram of the second conventional technique.

【図９】従来の第２技術の制御説明図。 発明を実施するための最良の形態 図１に示す第一実施例は、ガス焚式二重効用形の吸収
式冷凍機であって、冷媒液の散布器12及び冷媒ポンプ13
をもち、冷媒を蒸発させて冷水管11に冷房負荷に供給す
る冷水を取り出す蒸発器１と、該蒸発器１と同一容器20
内にエリミネータ21を挟んで隣接状に設けられ、濃溶液
の散布器22及び冷却水配管23をもち、蒸発器１で蒸発し
た冷媒を溶液に吸収させる吸収器２と、該吸収器２と溶
液ポンプ60並びに低温熱交換器61及び高温熱交換器62を
介して接続され、バーナー31aから成る加熱源31により
吸収器２で多量に冷媒を吸収した稀溶液から冷媒を発生
させる高温側の発生器３、該発生器３で発生する冷媒蒸
気を流す加熱器41をもち、高温側の発生器３で再生され
て高温熱交換器62を通過した後の中間濃度溶液から冷媒
を発生させる低温側の発生器４と、該低温側の発生器４
と同一容器50内に設けられ、吸収器２の冷却水配管23の
後段に連続して設ける冷却水配管24により各発生器3,4
で発生した冷媒蒸気を凝縮させる擬縮器５とを備えてい
る。 高温側の発生器３に具備するバーナー31aの加熱量
は、該バーナー31aへの供給燃料を制御する燃料供給弁3
2a及びその開度調節器32bから成る加熱量制御手段32に
よって変更可能としており、通常運転時は、冷水管11の
出口側に介装し、負荷検出手段６の一つを構成する冷水
出口温度検出器62の検出値に基づいて、燃料供給弁32a
を開度調節し、これにより、冷房負荷の大小に応じてそ
の加熱量を増減制御するようにしている。尚、冷房負荷
は、冷水出口温度検出器62と冷水入口温度検出器61とを
組み合わせて、冷水出入口温度差により検出するように
してもよい。 以上の構成において、濃溶液の濃度を検出する濃度検
出手段７を設ける。この濃度検出手段７は、低温側の発
生器４の出口に設ける温度検出器71と、吸収器２を経て
凝縮器５に供給する冷却水の入口温度を検出する冷却水
温検出手段51あるいは凝縮器５の冷媒温度検出器とによ
り濃度検出を行う。又、温度検出器71と、発生器４の胴
内の圧力を検出する圧力検出器とにより濃度検出を行っ
てもよい。尚、温度検出器71は、低温側の発生器４の出
口部から低温熱交換器61を経て濃溶液の散布器22に至る
配管中に設けてもよい。 又、負荷検出手段６を構成する冷水出口温度検出器62
の検出値又はこの出口温度検出器62と冷水入口温度検出
器61とで検出する温度差で知ることのできる検出冷房負
荷が小さいとき、図２に示すように、濃溶液の最高許容
限界温度を低く、検出冷房負荷が大きいとき、同限界温
度を高く定める濃溶液の限界濃度設定手段８を設ける。 図２に示す許容限界濃度は、安定した正常な状態のサ
イクル線の各負荷に対応する低温側の発生器４の出口の
濃溶液の濃液に0.5％を加えたものである。従って、安
定した正常な状態では、この限界濃度よりも0.5％程低
い濃度で運転している。 更に、濃度検出手段７で検出する濃溶液の検出濃度が
図２で定めた限界濃度を越えることとなるとき加熱量制
御手段32を構成する開度調節器32bに加熱量の制限指令
すなわち開度減少指令を与える加熱量制限手段９を設け
る。具体的には、この加熱量制限手段９は、所定時間毎
に燃料供給弁32aの開度を数％〜数十％程度絞ることに
より加熱量を一ステップずつ段階的に制限していくステ
ップ制限手段90で構成している。この他、加熱量制限手
段９は、所定時間毎に開度を半減していくものとした
り、あるいは、極端には、いきなり加熱量を零に制限し
てしまうものとしてもよい。 又、以上のものでは、加熱量制限手段９による制御で
検出濃度が限界濃度を下回らないとき、加熱量を零にし
て燃焼を停止させると共に、各ポンプ駆動制御手段600,
130を介して溶液ポンプ60及び冷媒ポンプ13を停止さ
せ、運転を非常停止させる非常停止手段10を設けている
と共に、この非常停止手段10の発動による非常停止時、
ランプやブザー等で警報を発する警報手段900を設けて
いる。 更に、以上のものでは、冷却水配管23の入口部に、吸
収器２及び該吸収器２を経て濃縮器５に供給する冷却水
の温度を検出する冷却水温検出手段51を設けていると共
に、その検出冷却水温の単位時間あたりの変化値を求め
る変化値演算手段52と、濃溶液の検出濃度が図２に示す
限界濃度を越えるが、同時に冷却水温の変化値が図３に
示すように例えば５℃／秒程度の所定値を上回る場合に
は、例えば３分間程度の所定時間だけ加熱量制限手段９
による制御を待機させる待機手段91と、待機時間経過後
の検出濃度が限界濃度をなおも越える場合には加熱量制
限手段９による制御に移行させる遅延起動手段92とを設
けている。 尚、以上の制御にかかわる各手段8,9,10,900,52,91,9
2はマイクロコンピュータを具備するコントローラ100に
より構築している。 こうして、一連の制御は、図４に示すようになされ
る。すなわち、先ず、検出冷房負荷から限界濃度を設定
し（ステップａ）、検出濃度と限界温度との比較で（ス
テップｂ）、検出濃度が限界濃度を越えていない場合は
通常の検出冷房負荷に基づく加熱制御を行うのに対し
（ステップｃ）、検出濃度が限界濃度を超える場合は冷
却水温の変化値を評価する（ステップｄ）。所定値つま
り５℃／秒を上回るときは３分間の待機時間を経た後
（ステップｅ）に再び検出濃度と限界濃度との比較（ス
テップｆ）で限界濃度を越える場合に、一方５℃／秒を
下回るときは直ちに、燃料制御弁32aの開度が最小か否
かの判定（ステップｇ）に引き続いて燃料制御弁32aの
開度を一ステップ絞り（ステップｈ）、数十秒程度の所
定時間の経過後（ステップｉ）、再び検出濃度の評価を
行い（ステップｆ）、限界温度を下回ることとなった場
合は通常制御に移行するが（ステップｃ）、燃料制御弁
32aを最小まで絞っても限界濃度を下回らない場合は
（ステップｇ）、警報と共に（ステップｊ）、運転を非
常停止させている（ステップｋ）。 図５は第二実施例を示し、このものは、加熱量の制限
制御つまり結晶防止制御に移行させる際の遅延制御の別
例であり、冷却水温検出手段51に代えて凝縮器５の冷媒
温度を検出する冷媒温度検出手段510を用い、検出冷媒
温度の単位時間あたりの変化値を求める変化値演算手段
520と、濃溶液の検出濃度が限界濃度を越えるが冷媒温
度の変化値が所定値を上回る場合には所定時間だけ加熱
量制限手段９による制御を待機させる待機手段910と、
待機時間経過後の検出濃度が限界濃度をなおも越える場
合には加熱量制御手段９による制御に移行させる遅延起
動手段920とを設けたものであり、この場合にも、上記
同様の制御が行える。 産業上の利用可能性 以上のように、本発明の吸収式冷凍機は、主として冷
媒に水を、吸収溶液に臭化リチウム水溶液をそれぞれ用
い、構成機器として、蒸発器、吸収器、発生器及び凝縮
器を備える吸収式冷凍機に有用である。FIG. 9 is a control explanatory diagram of the second conventional technique. BEST MODE FOR CARRYING OUT THE INVENTION The first embodiment shown in FIG. 1 is a gas-fired double-effect absorption refrigerator having a refrigerant liquid sprayer 12 and a refrigerant pump 13.
An evaporator 1 for evaporating a refrigerant and extracting cold water to be supplied to a cooling load to a chilled water pipe 11;
An absorber 2 which is provided adjacent to the eliminator 21 and has a sprayer 22 for the concentrated solution and a cooling water pipe 23 for absorbing the refrigerant evaporated by the evaporator 1 into the solution; A high-temperature generator that is connected via a pump 60 and a low-temperature heat exchanger 61 and a high-temperature heat exchanger 62 and that generates a refrigerant from a dilute solution in which a large amount of the refrigerant has been absorbed by the absorber 2 by a heating source 31 composed of a burner 31a. 3. A heater 41 having a heater 41 for flowing a refrigerant vapor generated in the generator 3 and generating a refrigerant from an intermediate-concentration solution that has been regenerated by the generator 3 on the high-temperature side and passed through the high-temperature heat exchanger 62. Generator 4 and the low-temperature side generator 4
The cooling water pipes 24 provided in the same vessel 50 and provided at the subsequent stage of the cooling water pipes 23 of the absorber 2 make the respective generators 3, 4
And a pseudo-condenser 5 for condensing the refrigerant vapor generated in the above. The amount of heating of the burner 31a provided in the high-temperature side generator 3 depends on the fuel supply valve 3 for controlling the fuel supply to the burner 31a.
2a and its opening degree adjuster 32b can be changed by the heating amount control means 32. During normal operation, the cooling water outlet temperature which is interposed on the outlet side of the chilled water pipe 11 and constitutes one of the load detecting means 6 Based on the detection value of the detector 62, the fuel supply valve 32a
, And the amount of heating is controlled to increase or decrease according to the magnitude of the cooling load. The cooling load may be detected based on a difference in the temperature of the cold water inlet / outlet by combining the cold water outlet temperature detector 62 and the cold water inlet temperature detector 61. In the above configuration, the concentration detecting means 7 for detecting the concentration of the concentrated solution is provided. The concentration detecting means 7 includes a temperature detector 71 provided at an outlet of the generator 4 on the low temperature side, a cooling water temperature detecting means 51 for detecting an inlet temperature of the cooling water supplied to the condenser 5 via the absorber 2, or a condenser. The concentration is detected by the refrigerant temperature detector of No. 5. Alternatively, concentration detection may be performed by the temperature detector 71 and a pressure detector that detects the pressure inside the body of the generator 4. The temperature detector 71 may be provided in a pipe extending from the outlet of the low-temperature side generator 4 to the concentrated solution sprayer 22 via the low-temperature heat exchanger 61. Further, a chilled water outlet temperature detector 62 constituting the load detecting means 6 is provided.
When the detected cooling load, which can be known from the detected value of or the temperature difference detected between the outlet temperature detector 62 and the chilled water inlet temperature detector 61, is small, as shown in FIG. When the cooling load is low and the detected cooling load is large, a limit concentration setting means 8 for a concentrated solution for setting the limit temperature high is provided. The allowable limit concentration shown in FIG. 2 is obtained by adding 0.5% to the concentrated solution of the concentrated solution at the outlet of the generator 4 on the low temperature side corresponding to each load of the cycle line in a stable normal state. Therefore, in a stable and normal state, operation is performed at a concentration that is about 0.5% lower than the limit concentration. Further, when the detected concentration of the concentrated solution detected by the concentration detecting means 7 exceeds the limit concentration defined in FIG. 2, the opening degree controller 32b constituting the heating amount control means 32 is instructed to restrict the heating amount, that is, the opening degree. A heating amount limiting means 9 for giving a decrease command is provided. Specifically, the heating amount limiting means 9 limits the heating amount step by step by reducing the opening of the fuel supply valve 32a by several percent to several tens percent at predetermined time intervals. Means 90 are provided. In addition, the heating amount limiting means 9 may reduce the opening degree by half every predetermined time, or, in an extreme case, may suddenly limit the heating amount to zero. Further, in the above, when the detected concentration does not fall below the limit concentration by the control of the heating amount limiting means 9, the heating amount is set to zero to stop the combustion, and the pump drive control means 600,
The solution pump 60 and the refrigerant pump 13 are stopped via 130, and the emergency stop means 10 for emergency stop of the operation is provided, and at the time of emergency stop by activation of the emergency stop means 10,
An alarm unit 900 that issues an alarm using a lamp, a buzzer, or the like is provided. Further, in the above, at the inlet of the cooling water pipe 23, the absorber 2 and the cooling water temperature detecting means 51 for detecting the temperature of the cooling water supplied to the concentrator 5 via the absorber 2 are provided, A change value calculating means 52 for obtaining a change value of the detected cooling water temperature per unit time, and a detection value of the concentrated solution exceeding the limit concentration shown in FIG. If the temperature exceeds the predetermined value of about 5 ° C./sec, the heating amount restricting means 9 is kept for a predetermined time of about 3 minutes, for example.
And a delay activation means 92 for shifting to control by the heating amount limiting means 9 if the detected density after the elapse of the standby time still exceeds the limit density. In addition, each means related to the above control 8, 9, 10, 900, 52, 91, 9
2 is constructed by a controller 100 having a microcomputer. Thus, a series of controls are performed as shown in FIG. That is, first, the limit concentration is set from the detected cooling load (step a), and the detected concentration is compared with the limit temperature (step b). If the detected concentration does not exceed the limit concentration, the detected concentration is based on the normal detected cooling load. While the heating control is performed (step c), when the detected concentration exceeds the limit concentration, the change value of the cooling water temperature is evaluated (step d). If it exceeds the predetermined value, that is, 5 ° C./sec, after a waiting time of 3 minutes (step e), the detected concentration is again compared with the limit concentration (step f). Immediately below, the determination is made as to whether or not the opening of the fuel control valve 32a is minimum (step g), and then the opening of the fuel control valve 32a is reduced by one step (step h) for a predetermined time of about several tens of seconds. (Step i), the detected concentration is evaluated again (step f), and when the temperature falls below the limit temperature, the control is shifted to the normal control (step c).
When the density does not fall below the limit concentration even when the aperture 32a is squeezed to the minimum (step g), the operation is emergency stopped (step k) with an alarm (step j). FIG. 5 shows a second embodiment, which is another example of the delay control when shifting to the heating amount limiting control, that is, the crystallization prevention control, in which the cooling water temperature detecting means 51 is replaced with the refrigerant temperature of the condenser 5. Change value calculating means for calculating a change value per unit time of the detected refrigerant temperature using the refrigerant temperature detecting means 510 for detecting
520, and standby means 910 for waiting for control by the heating amount limiting means 9 for a predetermined time when the detected concentration of the concentrated solution exceeds the limit concentration but the change value of the refrigerant temperature exceeds a predetermined value,
If the detected concentration after the elapse of the standby time still exceeds the limit concentration, a delay activation unit 920 for shifting to the control by the heating amount control unit 9 is provided. In this case, the same control as described above can be performed. . INDUSTRIAL APPLICABILITY As described above, the absorption refrigerator of the present invention mainly uses water as a refrigerant and an aqueous solution of lithium bromide as an absorption solution, and as constituent components, an evaporator, an absorber, a generator and Useful for absorption refrigerators with condensers.

フロントページの続き (58)調査した分野(Int.Cl.⁶，ＤＢ名) F25B 15/00 306 Continuation of front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F25B 15/00 306

Claims (7)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】冷媒を蒸発させて冷房負荷に供給する冷熱
を取り出す蒸発器（１）、該蒸発器（１）で蒸発した冷
媒を溶液に吸収させる吸収器（２）、該吸収器（２）で
冷媒を吸収した溶液から冷媒を発生させて濃縮した濃溶
液を前記吸収器（２）に供給する発生器（3,4）及び該
発生器（3,4）で発生した冷媒を凝縮させて液冷媒を前
記蒸発器（１）に供給する凝縮器（５）を備え、負荷検
出手段（６）で検出する検出冷房負荷の大小に応じて発
生器（３）に具備する加熱源（31）の加熱量を増減制御
する加熱量制御手段（32）を設けた吸収式冷凍機におい
て、濃溶液の濃度を検出する濃度検出手段（７）と、検
出冷房負荷が小さいとき濃溶液の最高許容限界濃度を低
く、検出冷房負荷が大きいとき同限界濃度を高く定める
濃溶液の限界濃度設定手段（８）と、濃溶液の検出濃度
が限界濃度を越えることとなるとき前記加熱量制御手段
（32）に加熱量の制限指令を与える加熱量制限手段
（９）とを設けたことを特徴とする吸収式冷凍機。An evaporator (1) for evaporating a refrigerant to extract cold heat supplied to a cooling load, an absorber (2) for absorbing the refrigerant evaporated by the evaporator (1) into a solution, and an absorber (2). A) generating a refrigerant from the solution that has absorbed the refrigerant in step (3), supplying a concentrated solution concentrated in the generator (3, 4) to the absorber (2), and condensing the refrigerant generated in the generator (3, 4). A condenser (5) for supplying liquid refrigerant to the evaporator (1), and a heating source (31) provided to the generator (3) according to the magnitude of the cooling load detected by the load detecting means (6). In the absorption type refrigerator provided with the heating amount control means (32) for increasing and decreasing the heating amount, the concentration detecting means (7) for detecting the concentration of the concentrated solution and the maximum allowable concentration of the concentrated solution when the detected cooling load is small. When the detection limit cooling concentration is low and the detection cooling load is large, set the limit concentration to a high value. A step (8) and a heating amount limiting means (9) for giving a heating amount limiting command to the heating amount controlling means (32) when the detected concentration of the concentrated solution exceeds the limit concentration. Absorption refrigerator. 【請求項２】加熱量制限手段（９）が、所定時間毎に加
熱量を一ステップずつ段階的に制限していくステップ制
限手段（90）である請求の範囲第１項に記載の吸収式冷
凍機。2. An absorption method according to claim 1, wherein said heating amount limiting means (9) is a step limiting means (90) for limiting the heating amount step by step at predetermined time intervals. refrigerator. 【請求項３】加熱量制限手段（９）による制御で検出濃
度が限界濃度を下回らないとき、運転を非常停止させる
非常停止手段（10）を備える請求の範囲第１項又は第２
項記載の吸収式冷凍機。3. An emergency stop means (10) for urgently stopping the operation when the detected concentration does not fall below the limit concentration under the control of the heating amount limiting means (9).
The absorption refrigerator described in the item. 【請求項４】非常停止手段（10）の発動時、警報を発す
る警報手段（900）を備える請求の範囲第３項記載の吸
収式冷凍機。4. An absorption refrigerator according to claim 3, further comprising alarm means (900) for issuing an alarm when the emergency stop means (10) is activated. 【請求項５】吸収器（２）及び凝縮器（５）に供給する
冷却水の温度を検出する冷却水温検出手段（51）と、検
出冷却水温の単位時間あたりの変化値を求める変化値演
算手段（52）と、濃溶液の検出濃度が限界濃度を越える
が冷却水温の変化値が所定値を上回る場合には所定時間
だけ加熱量制限手段（９）による制御を待機させる待機
手段（91）と、待機時間経過後の検出濃度が限界濃度を
なおも越える場合には加熱量制限手段（９）による制御
に移行させる遅廷起動手段（92）とを備えている請求の
範囲第１項から第４項何れか一記載の吸収式冷凍機。5. A cooling water temperature detecting means (51) for detecting a temperature of cooling water supplied to an absorber (2) and a condenser (5), and a change value calculation for obtaining a change value of the detected cooling water temperature per unit time. Means (52) and standby means (91) for waiting for control by the heating amount limiting means (9) for a predetermined time when the detected concentration of the concentrated solution exceeds the limit concentration but the change value of the cooling water temperature exceeds a predetermined value. And a delay starting means (92) for shifting to control by the heating amount limiting means (9) when the detected concentration after the elapse of the standby time still exceeds the limit concentration. An absorption refrigerator according to any one of claims 4 to 9. 【請求項６】濃度検出手段（７）が、吸収器（２）及び
凝縮器（５）に供給する冷却水の入口温度を検出する冷
却水温検出手段（51）と、発生器（４）で濃縮した濃溶
液温度を検出する濃溶液温度検出手段（71）とで溶液濃
度を決定するものである請求の範囲第５項記載の吸収式
冷凍機。6. A cooling water temperature detecting means (51) for detecting an inlet temperature of cooling water supplied to an absorber (2) and a condenser (5), and a concentration detecting means (7). The absorption refrigerator according to claim 5, wherein the concentration of the solution is determined by a concentrated solution temperature detecting means (71) for detecting the temperature of the concentrated concentrated solution. 【請求項７】凝縮器（５）の冷媒温度を検出する冷媒温
度検出手段（510）と、検出冷媒温度の単位時間あたり
の変化値を求める変化値演算手段（520）と、濃溶液の
検出濃度が限界濃度を越えるが冷媒温度の変化値が所定
値を上回る場合には所定時間だけ加熱量制限手段（９）
による制御を待機させる待機手段（910）と、待機時間
経過後の検出濃度が限界濃度をなおも越える場合には加
熱量制限手段（９）による制御に移行させる遅延起動手
段（920）とを備えている請求の範囲第１項から第４項
何れか一記載の吸収式冷凍機。7. A refrigerant temperature detecting means (510) for detecting a refrigerant temperature of the condenser (5), a change value calculating means (520) for obtaining a change value of the detected refrigerant temperature per unit time, and detection of a concentrated solution. When the concentration exceeds the limit concentration but the change value of the refrigerant temperature exceeds a predetermined value, the heating amount limiting means (9) for a predetermined time.
(910), and a delay activation means (920) for shifting to control by the heating amount limiting means (9) if the detected density after the elapse of the standby time still exceeds the limit density. The absorption refrigerator according to any one of claims 1 to 4, wherein: