JP3880333B2

JP3880333B2 - Absorption refrigeration equipment

Info

Publication number: JP3880333B2
Application number: JP2001155198A
Authority: JP
Inventors: 修行井上; 利男松原; 智芳入江
Original assignee: Ebara Corp
Current assignee: Ebara Corp
Priority date: 2001-05-24
Filing date: 2001-05-24
Publication date: 2007-02-14
Anticipated expiration: 2021-05-24
Also published as: JP2002349984A

Description

【０００１】
【発明の属する技術分野】
本発明は、吸収冷凍装置に係り、特に、希溶液流路に制御弁を設け、低ポテンシャルエネルギ単独の運転を可能にした吸収冷凍装置に関する。
【０００２】
【従来の技術】
通常の吸収冷凍機において、熱源熱量を調整するのは、冷水負荷信号又は冷水温度信号に基づいている。二重効用吸収冷凍機において、高温再生器と吸収器との差圧及び位置ヘッドが、高温再生器から吸収器に溶液を流す駆動力となる。一般に、定格条件における駆動力にて、必要な流量となるように、流路抵抗を調整し、オリフィス等を入れている。このように、高温再生器の圧力が変化すると、前記駆動力が変化するので、高温再生器の流出量が変化する。この流出量に見合うように流入量を調整している。
従来から、高温再生器出口部の液位を検出し、液位がある範囲で保持できるように、高温再生器への流入量を調整したり、あるいは流出量を調整したりしており、種々の溶液流路が提案されている（例えば、特公昭５８−２３５４１号公報参照）。
【０００３】
また希溶液ラインに、吸収冷凍機外部の単一排熱源から供給される流体と希溶液ラインを流れる吸収希溶液とを熱交換する排熱回収用熱交換器を介装した複合冷房装置も提案されている（特開平７−２１８０１５号あるいは特開平７−２１８０１８号各公報参照）。
コージェネレーションシステムでは、電気と共に、比較的温度の低い温水が供給される。この温水は、温度があまり高くなく、低ポテンシャルエネルギに分類され、給湯又は暖房に利用されることが多い。最近は、吸収冷凍機の熱源として冷房に利用することも多くなってきている。
コージェネレーションシステムの中で、この温水は、エンジンの冷却（ジャケット温水）あるいはエンジン排気からの熱回収、あるいは、燃料電池の場合の冷却用として得られる。低ポテンシャルエネルギ単独で、吸収冷凍機を運転する場合もあるが、前述の複合冷房装置のように、高ポテンシャルエネルギと共に用い、必要とする高ポテンシャルエネルギの量を減らそうという使い方も提案され、採用され出している。
【０００４】
ところで、これらの吸収冷凍装置は、いずれも、冷水負荷が小さく、高ポテンシャルエネルギが不要となるような負荷状態でも、通常は、高ポテンシャルエネルギを用いないと高温再生器の内圧が低く、高温再生器から吸収器に溶液を戻すことができないため、高ポテンシャルエネルギと低ポテンシャルエネルギの同時使用が必要で、両者同時の発停となり、単独使用ができないという問題点があった（特開平７−２１８０１５号公報）。
この問題を解決するものとして、特開平７−２１８０１８号が提案されているが、溶液の流れを三方弁で選択的に切替えているため、切替時の変動が大きくなりがちである。特に、高ポテンシャルエネルギを止め、低ポテンシャル単独運転に移る時には、高温熱交換器、高温再生器の濃度を低下させ、流動停止中の結晶防止をする必要があり、移行のための時間がかかる等の問題点があった。
【０００５】
【発明が解決しようとする課題】
本発明は、上記従来技術の問題点を解決し、冷水負荷が小さく、高ポテンシャルエネルギが不要となるような負荷状態の時に、低ポテンシャルエネルギの単独使用を簡単な装置構成の変更によって可能にする吸収冷凍装置を提供することを課題とする。
【０００６】
【課題を解決するための手段】
上記課題を解決するために、本発明では、吸収器、低温再生器、高温再生器、凝縮器、蒸発器、低温溶液熱交換器、高温溶液熱交換器、溶液ポンプ、冷媒ポンプ及びこれらの機器を接続する溶液流路と冷媒流路を備え、熱源として低ポテンシャルエネルギと高ポテンシャルエネルギとを用いる吸収冷凍装置であって、前記溶液流路と冷媒流路には、冷房サイクルと暖房サイクルの切替機構を有し、前記溶液流路は、溶液ポンプにより希溶液を希溶液分岐点から、一部は低温再生器に、残部は高温再生器に導く流路とし、前記低温再生器は、低ポテンシャルエネルギによる加熱機構と、高温再生器で発生した冷媒蒸気による加熱機構とを備え、該低温再生器内の溶液の流れに沿って、低ポテンシャルエネルギによる加熱機構を上流側に、高温再生器からの冷媒蒸気による加熱機構を下流側に配し、希溶液を分岐点から高温再生器に導く流路中に、溶液循環量を制御する弁を設け、該弁に、冷暖房負荷が小さく高温再生器に高ポテンシャルエネルギを用いる必要がない場合には、該弁を閉止又は閉止付近に制御する制御機構を設けると共に、前記高温再生器には、高ポテンシャルエネルギ調節機構を、前記低温再生器には、低ポテンシャルエネルギ調節機構を備え、該低ポテンシャルエネルギを優先的に用い、熱源が不足するときに高ポテンシャルエネルギを用いて、冷房能力又は暖房能力を制御する制御機構を有し、前記低ポテンシャルエネルギ調節機構が、低温再生器の加熱部に導入又は散布する溶液流量を調節する溶液弁であることを特徴とする吸収冷凍装置としたものである。
【０００８】
【発明の実施の形態】
前記のように、本発明は、低温熱交換器と高温熱交換器との間の希溶液流路に分岐点を有し、一部の溶液を低温再生器に、残部を高温熱交換器を経由して高温再生器に導くサイクルにおいて、低温再生器の加熱部の上流側に低ポテンシャルエネルギによる加熱機器を配すると共に、前記分岐点と高温熱交換器の間に、溶液循環量を制御する弁を設け、高温再生器へ高ポテンシャルエネルギを用いる必要がない冷房負荷の場合は、該弁を閉止又は閉止付近に制御する制御機構を有するものである。
次に、本発明を、図１〜図４に示す吸収冷凍装置のフロー構成図を用いて説明する。なお、図１と図２は、本発明を説明するための参考例であり、図３と図４は、本発明の装置例である。
【０００９】
図１〜図４において、Ａは吸収器、ＧＬは低温再生器、ＧＨは高温再生器、Ｃは凝縮器、Ｅは蒸発器、ＸＬは低温熱交換器、ＸＨ、ＸＨａ、ＸＨｂは高温熱交換器、ＳＰは溶液ポンプ、ＲＰは冷媒ポンプ、Ｆはフロート、Ｌａは低ポテンシャルエネルギを用いる加熱機構、Ｌｂは高温再生器からの冷媒蒸気を用いる加熱機構、Ｖ１〜Ｖ６は切替弁、１は冷暖房負荷に接続する冷水配管、２は冷却水配管、３、４は熱源配管、５は温度センサ、６は制御器、７は熱源熱量調整弁、８は循環量制御弁、９はインバータ回転数制御器、１１〜１６は冷媒流路、２１〜３１は溶液流路、２０は分岐点である。
図１を用いて、この吸収冷凍装置の運転操作について説明すると、この装置の通常の高ポテンシャルエネルギを用いて加熱する冷房運転においては、冷媒を吸収した希溶液は、吸収器Ａから溶液ポンプＳＰにより低温熱交換器ＸＬの被加熱側を経た後、希溶液分岐点２０より、一部は低温再生器ＧＬに、残部は高温熱交換器ＸＨの被加熱側を通り流路２３から高温再生器ＧＨに導入される。高温再生器ＧＨでは希溶液は加熱熱源により加熱されて冷媒を蒸発して濃縮され、濃縮された濃溶液は流路２６を通り高温熱交換器ＸＨで熱交換され、流路２７から低温再生器ＧＬからの濃溶液２５と合流する。
【００１０】
分岐点２０より流路２４を通り低温再生器に導入された希溶液は、低温再生器で低ポテンシャルエネルギを用いて加熱する加熱機構Ｌａ及び高温再生器からの冷媒蒸気により加熱される加熱機構Ｌｂにより、加熱濃縮された後、流路２５で高温再生器からの濃溶液と合流した後、低温熱交換器ＸＬの加熱側を通り、流路２８から吸収器Ａに導入される。
高温再生器ＧＨで蒸発した冷媒ガスは、冷媒流路１３を通り、低温再生器ＧＬの熱源として用いられたのち凝縮器Ｃに導入される。凝縮器Ｃでは、低温再生器ＧＬからの冷媒ガスと共に冷却水により冷却されて凝縮し、流路１２から蒸発器Ｅに入る。蒸発器Ｅでは、冷媒が冷媒ポンプＲＰにより、流路１１により循環されて蒸発し、その際に蒸発熱を負荷側の冷水から奪い、冷水を冷却し、冷房に供される。
蒸発した冷媒は、吸収器Ａで濃溶液により吸収されて、希溶液となり溶液ポンプで循環されるサイクルとなる。
【００１１】
このような吸収冷凍装置において、吸収器Ａから高温再生器ＧＨに溶液を送る溶液ポンプＳＰをインバータ９により、回転数可変とし、さらに、中間点２０から高温再生器ＧＨまでの希溶液ライン中に、溶液制御弁８を設ける。
通常の運転では、高温再生器ＧＨへの溶液制御弁８を全開（あるいは所定の開度）とし、高温再生器ＧＨの液面をフロートＦで検出し、制御するように溶液ポンプＳＰの回転数を調節する。
溶液ポンプの回転数は、基本回転数を高温再生器の冷媒飽和温度（又は相当温度、あるいは圧力）で決め、これにフロートＦで微調整するなどの方法もとられる。
温度センサ５の検出値が所定値より低下したとき、負荷が小さいと判断して、高ポテンシャルエネルギの供給を停止し、低ポテンシャルエネルギの単独運転とする。
【００１２】
また、低ポテンシャルエネルギ単独運転中、温度センサ５の検出値が所定値より上昇したとき、負荷が大きくなったと判断して、高ポテンシャルエネルギの供給を再開し、低ポテンシャルと高ポテンシャルエネルギの併用に戻る。
なお、低ポテンシャルエネルギ（温水）の供給温度により、単独運転による冷凍能力が変化する（温水温度上昇で能力大。温水温度下降で能力小）ので、前述の判断に用いる所定値を、温水温度の関数としてもよい。この場合、ポテンシャルのエネルギが無い場合（高ポテンシャル単独運転）も含め、単一のロジックで、高ポテンシャルエネルギの供給停止の制御ができる。
負荷の大小は、冷水出入口温度差の所定値との比較、あるいは、直接冷水負荷（冷水出入口温度差×冷水流量）を算出し、所定値と比較する等の方法がとられる。
【００１３】
冷房負荷を温度センサ５で検出して、小さく高ポテンシャルエネルギを使用せずに低ポテンシャルエネルギを単独で使用する場合には、溶液制御弁８を全閉あるいは閉止近くとし、高温再生器ＧＨへの流量を、高温再生器ＧＨから吸収器Ａに溶液を戻せる流量（通常、アクチュアルヘッドのみとなる）以下として、運転する。この際、低温再生器ＧＬには、溶液流量を多く流したいので、溶液ポンプＳＰの回転数制御を高温再生器の液面ではなく、所定の回転数にする。
また、冷水負荷に応じて、溶液ポンプの回転数を調節することもできる。
このように、本発明では、低温再生器に低ポテンシャルエネルギによる加熱機構Ｌａを設けると共に、溶液制御弁を設けているので、高温再生器ＧＨと切り離して低温再生器ＧＬのみを単独で運転することができるようになった。
図２は、図１の吸収冷凍装置において、分岐点２０を低温熱交換機ＸＬの前に配し、高温再生器への希溶液を加熱する高温再生器をＸＨａ、ＸＨｂの２段用いて、高温再生器からの濃溶液で加熱することとしたものであり、図１と同様の作用・効果を有する。
【００１４】
図３、図４は、それぞれ図１、図２に対応し、図１、図２に暖房サイクルにも適用可能なように、冷房サイクルと暖房サイクルの切替機構を設け、該機構が、前記高温再生器ＧＨからの冷媒蒸気を蒸発器Ｅ又は吸収器Ａに導く冷媒流路１４に設けた蒸気弁Ｖ１とするか、前記蒸発器Ｅ下部の液を吸収器Ａ又は吸収器につながる溶液流路２１に導く冷媒流路１５に設けた弁Ｖ２とするか、前記濃溶液２５を、低温熱交換器ＸＬをバイパスさせて、吸収器Ａに導く溶液流路２９に設けた弁Ｖ３とするか、又は、前記低温再生器ＧＬの発生蒸気を蒸発器Ｅ又は吸収器Ａに導く冷媒流路１６に設けた弁Ｖ３’としたものである。
また、温水単独運転のときの、容量制御法として、熱源投入量を、低温再生器ＧＬ加熱部への溶液導入量で調節する弁Ｖ５を有している。該Ｖ５を三方弁として、温水温度が溶液温度より低い時、熱が外部温水３に逃げるのを防ぐため、溶液流路３０を設け、溶液の導入位置を切替えてもよい。Ｖ５は三方弁の代りに、散布量を直接制御する二方弁としてもよく、また、散布をバイパスし、下部にブローする二方弁であってもよい。また、ＳＰの回転数を調節して散布量を制御する方法もとれる。また、温水温度が溶液温度より低い時、温水熱源３が低温再生器ＧＬをバイパスする弁Ｖ６を設けてもよい。
【００１５】
さらに、暖房サイクルのとき、蒸発器Ｅで冷媒の凝縮をさせる方式では、凝縮温度に対し、溶液温度は少なくとも沸点上昇分は温度が高くなっており、低温再生器ＧＬで温水から溶液に熱を与え、蒸気を発生させるのが難しくなる。
例えば、溶液濃度と溶液の平衡温度の関係を、ＬｉＢｒ水溶液を例に下記に示す。
【表１】

【００１６】
排熱としての温水は、９０℃程度が最高温で、通常８０℃程度まで利用する。冷房サイクル時、５５ｗｔ％〜６２ｗｔ％程度の溶液を、暖房サイクル時には、４０ｗｔ％近くまで希釈する必要があり、このため、希釈用冷媒を多量に装置内に持っておく必要がある。
本発明では、低温再生器ＧＬからの溶液流路２５からバイパス管３１を接続し、このバイパス管に弁Ｖ４を設けて蒸発器Ｅに溶液を散布し、上述の関係を変えるものであり、例えば、低温再生器ＧＬの溶液濃度と蒸発器Ｅに散布する溶液濃度とをほぼ同じにすると、沸点上昇分をほとんど解消できる。
【００１７】
例えば、５５ｗｔ％のＬｉＢｒ水溶液とすると、
濃度５５ｗｔ％
低温再生器飽和温度（露点）４０．４℃ 溶液温度７５℃
蒸発器飽和温度（露点）３５．４℃ 溶液温度６９．２℃
の関係が有り、単純に説明すれば、温水で、５５ｗｔ％溶液が温水で７５℃まで加熱沸騰させられると、飽和温度４０．４℃の蒸気が発生し、これが圧力損失を伴って、蒸発器に入り、蒸発器の５５ｗｔ％溶液に吸収される。その際の溶液温度は約７３℃である。蒸気の流れで飽和温度に差がでてくるが、この圧力差は、配管のＶ３’のサイズなどが関係する。
溶液の戻しのため、ある程度の差圧が必要であり、弁サイズを選定し、場合によっては配管中にオリフィスを入れて差圧を付けるようにする。
【００１８】
【発明の効果】
前記のように、本発明では、低温再生器のみの単独運転が可能となったので、吸収冷凍装置の低負荷の場合の効率的な運転ができ、エネルギ的にも経済的にも効率のよい吸収冷凍装置が提供できた。
【図面の簡単な説明】
【図１】本発明を説明するための参考例である吸収冷凍装置の一例を示すフロー構成図。
【図２】本発明を説明するための参考例である吸収冷凍装置の他の例を示すフロー構成図。
【図３】本発明の吸収冷凍装置の一例を示すフロー構成図。
【図４】本発明の吸収冷凍装置の他の例を示すフロー構成図。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an absorption refrigeration apparatus, and more particularly, to an absorption refrigeration apparatus in which a control valve is provided in a dilute solution flow path to enable operation with low potential energy alone.
[0002]
[Prior art]
In a normal absorption refrigerator, the heat source heat quantity is adjusted based on a chilled water load signal or a chilled water temperature signal. In the dual effect absorption refrigerator, the differential pressure between the high-temperature regenerator and the absorber and the position head provide driving force for flowing the solution from the high-temperature regenerator to the absorber. Generally, the flow path resistance is adjusted and an orifice or the like is inserted so that the required flow rate is obtained with the driving force under rated conditions. As described above, when the pressure of the high temperature regenerator changes, the driving force changes, so that the outflow amount of the high temperature regenerator changes. The inflow is adjusted to match the outflow.
Conventionally, the liquid level at the outlet of the high-temperature regenerator is detected, and the inflow amount to the high-temperature regenerator or the outflow amount is adjusted so that the liquid level can be maintained within a certain range. (See, for example, Japanese Patent Publication No. 58-23541).
[0003]
We also propose a combined cooling system with a waste heat recovery heat exchanger that exchanges heat between the fluid supplied from a single waste heat source outside the absorption refrigerator and the absorbed diluted solution flowing through the diluted solution line in the diluted solution line. (See Japanese Patent Application Laid-Open No. 7-218015 or Japanese Patent Application Laid-Open No. 7-218018).
In the cogeneration system, hot water having a relatively low temperature is supplied together with electricity. This hot water is not very high in temperature, is classified as low potential energy, and is often used for hot water supply or heating. Recently, it is increasingly used for cooling as a heat source of an absorption refrigerator.
In the cogeneration system, this hot water is obtained for engine cooling (jacket hot water), heat recovery from engine exhaust, or cooling in the case of a fuel cell. In some cases, the absorption chiller is operated with low potential energy alone, but it has also been proposed and used to reduce the amount of high potential energy required together with high potential energy, as in the above-mentioned combined cooling system. It has been started.
[0004]
By the way, all of these absorption refrigeration apparatuses usually have a low internal pressure of the high-temperature regenerator without using high potential energy, even under a load state where the chilled water load is small and high potential energy is not required. Since the solution cannot be returned from the vessel to the absorber, it is necessary to use high potential energy and low potential energy at the same time. Issue gazette).
Japanese Patent Laid-Open No. 7-218018 has been proposed as a solution to this problem. However, since the flow of the solution is selectively switched by a three-way valve, the fluctuation at the time of switching tends to be large. In particular, when stopping high potential energy and moving to low potential single operation, it is necessary to reduce the concentration of the high-temperature heat exchanger and high-temperature regenerator to prevent crystallization when the flow is stopped. There was a problem.
[0005]
[Problems to be solved by the invention]
The present invention solves the above-mentioned problems of the prior art, and enables a single use of low potential energy by a simple device configuration change in a load state where the chilled water load is small and high potential energy is unnecessary. It is an object to provide an absorption refrigeration apparatus.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, an absorber, a low temperature regenerator, a high temperature regenerator, a condenser, an evaporator, a low temperature solution heat exchanger, a high temperature solution heat exchanger, a solution pump, a refrigerant pump, and these devices An absorption refrigeration apparatus using a low potential energy and a high potential energy as a heat source, wherein the solution channel and the refrigerant channel are switched between a cooling cycle and a heating cycle. The solution flow path is a flow path that leads a dilute solution from a dilute solution branch point to a low-temperature regenerator and the rest to a high-temperature regenerator by a solution pump, and the low-temperature regenerator has a low potential. A heating mechanism using energy and a heating mechanism using refrigerant vapor generated in the high temperature regenerator are provided, and the heating mechanism using low potential energy is disposed upstream of the high temperature regenerator along the flow of the solution in the low temperature regenerator. Placed a heating mechanism by the refrigerant vapor from the vessel to the downstream side, the dilute solution from the branch point in the flow path leading to the high-temperature regenerator, a valve for controlling the solution circulation rate provided, the valve, heating and cooling tufts load If there is no need to use a high potential energy in the small high-temperature regenerator, Rutotomoni provided a control mechanism for controlling the near closed or closed valve, the said high-temperature regenerator, a high potential energy adjustment mechanism, said cold The regenerator has a low-potential energy adjustment mechanism, uses the low-potential energy preferentially, and has a control mechanism for controlling the cooling capacity or the heating capacity using the high-potential energy when the heat source is insufficient. In the absorption refrigeration apparatus, the low potential energy adjustment mechanism is a solution valve for adjusting a flow rate of a solution introduced or dispersed in a heating unit of a low temperature regenerator .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
As described above, the present invention has a branch point in the dilute solution flow path between the low-temperature heat exchanger and the high-temperature heat exchanger, a part of the solution in the low-temperature regenerator, and the rest in the high-temperature heat exchanger. In the cycle leading to the high temperature regenerator, a heating device with low potential energy is arranged upstream of the heating part of the low temperature regenerator, and the amount of solution circulation is controlled between the branch point and the high temperature heat exchanger. In the case of a cooling load in which a valve is provided and it is not necessary to use high potential energy for the high-temperature regenerator, a control mechanism for controlling the valve to close or close to close is provided.
The invention will now be described with reference to the flow diagram of shows to absorb refrigeration apparatus in FIGS. 1 and 2 are reference examples for explaining the present invention, and FIGS. 3 and 4 are apparatus examples of the present invention.
[0009]
1-4, A is an absorber, GL is a low temperature regenerator, GH is a high temperature regenerator, C is a condenser, E is an evaporator, XL is a low temperature heat exchanger, XH, XHa, and XHb are high temperature heat exchanges. , SP is a solution pump, RP is a refrigerant pump, F is a float, La is a heating mechanism that uses low potential energy, Lb is a heating mechanism that uses refrigerant vapor from a high temperature regenerator, V1 to V6 are switching valves, and 1 is an air conditioner Cold water piping connected to the load, 2 is cooling water piping, 3 and 4 are heat source piping, 5 is a temperature sensor, 6 is a controller, 7 is a heat source heat amount adjustment valve, 8 is a circulation amount control valve, and 9 is inverter rotation speed control. , 11-16 are refrigerant flow paths, 21-31 are solution flow paths, and 20 is a branch point.
The operation of the absorption refrigeration apparatus will be described with reference to FIG. 1. In the cooling operation in which heating is performed using the normal high potential energy of the apparatus, the diluted solution that has absorbed the refrigerant is supplied from the absorber A to the solution pump SP. After passing through the heated side of the low-temperature heat exchanger XL, from the dilute solution branch point 20, a part passes to the low-temperature regenerator GL and the remaining part passes through the heated side of the high-temperature heat exchanger XH from the flow path 23 to the high-temperature regenerator. Introduced to GH. In the high temperature regenerator GH, the dilute solution is heated by a heating heat source to evaporate the refrigerant and concentrated, and the concentrated concentrated solution passes through the flow path 26 and is heat exchanged by the high temperature heat exchanger XH. Merge with concentrated solution 25 from GL.
[0010]
The dilute solution introduced into the low temperature regenerator through the flow path 24 from the branch point 20 is heated by the low temperature regenerator using low potential energy and the heating mechanism Lb heated by the refrigerant vapor from the high temperature regenerator. Thus, after being concentrated by heating, the concentrated solution from the high-temperature regenerator is merged in the flow path 25, and then passed through the heating side of the low-temperature heat exchanger XL and introduced into the absorber A from the flow path 28.
The refrigerant gas evaporated in the high temperature regenerator GH passes through the refrigerant flow path 13, is used as a heat source for the low temperature regenerator GL, and is then introduced into the condenser C. In the condenser C, the refrigerant gas is cooled and condensed by the cooling water together with the refrigerant gas from the low temperature regenerator GL, and enters the evaporator E through the flow path 12. In the evaporator E, the refrigerant is circulated through the flow path 11 by the refrigerant pump RP to evaporate. At that time, the evaporating heat is taken from the cold water on the load side, the cold water is cooled, and supplied to the cooling.
The evaporated refrigerant is absorbed by the concentrated solution in the absorber A to become a dilute solution and is circulated by a solution pump.
[0011]
In such an absorption refrigeration apparatus, the solution pump SP that sends the solution from the absorber A to the high-temperature regenerator GH is made variable by the inverter 9, and further, in the dilute solution line from the intermediate point 20 to the high-temperature regenerator GH. The solution control valve 8 is provided.
In normal operation, the solution control valve 8 to the high temperature regenerator GH is fully opened (or a predetermined opening), the liquid level of the high temperature regenerator GH is detected by the float F, and the rotation speed of the solution pump SP is controlled. Adjust.
The number of revolutions of the solution pump is determined by determining the basic number of revolutions based on the refrigerant saturation temperature (or equivalent temperature or pressure) of the high-temperature regenerator and finely adjusting the number by the float F.
When the detected value of the temperature sensor 5 falls below a predetermined value, it is determined that the load is small, the supply of high potential energy is stopped, and the single operation of low potential energy is performed.
[0012]
In addition, when the detected value of the temperature sensor 5 rises above a predetermined value during the low potential energy single operation, it is determined that the load has increased, and the supply of the high potential energy is resumed, so that the low potential and the high potential energy can be used together. Return.
In addition, since the refrigeration capacity by single operation changes depending on the supply temperature of low potential energy (warm water) (capacity increases when warm water temperature rises and capacity decreases when warm water temperature falls), the predetermined value used for the above-mentioned judgment is set to the warm water temperature It may be a function. In this case, even when there is no potential energy (high potential single operation), the supply stop of the high potential energy can be controlled with a single logic.
The magnitude of the load may be compared with a predetermined value of the chilled water inlet / outlet temperature difference or by directly calculating the chilled water load (cold water inlet / outlet temperature difference × cold water flow rate) and comparing it with a predetermined value.
[0013]
When the cooling load is detected by the temperature sensor 5 and the low potential energy is used alone without using the small high potential energy, the solution control valve 8 is fully closed or close to close to the high temperature regenerator GH. The operation is performed at a flow rate equal to or lower than a flow rate (usually only an actual head) at which the solution can be returned from the high temperature regenerator GH to the absorber A. At this time, since it is desired to flow a large amount of solution flow through the low temperature regenerator GL, the rotation speed control of the solution pump SP is set to a predetermined rotation speed instead of the liquid level of the high temperature regenerator.
Further, the rotational speed of the solution pump can be adjusted according to the cold water load.
As described above, in the present invention, the low temperature regenerator is provided with the heating mechanism La by low potential energy and the solution control valve is provided, so that only the low temperature regenerator GL is operated independently from the high temperature regenerator GH. Can now.
FIG. 2 shows that in the absorption refrigeration apparatus of FIG. 1, the branch point 20 is arranged in front of the low-temperature heat exchanger XL, and the high-temperature regenerator for heating the dilute solution to the high-temperature regenerator is used in two stages XHa and XHb. Heating is performed with a concentrated solution from the regenerator, which has the same functions and effects as in FIG.
[0014]
FIGS. 3 and 4 correspond to FIGS. 1 and 2, respectively, and a switching mechanism between a cooling cycle and a heating cycle is provided in FIGS. 1 and 2 so that the mechanism can be applied to the heating cycle. A vapor flow path V1 provided in the refrigerant flow path 14 for guiding the refrigerant vapor from the regenerator GH to the evaporator E or the absorber A, or a solution flow path for connecting the liquid below the evaporator E to the absorber A or the absorber. The valve V2 provided in the refrigerant flow path 15 leading to 21 or the valve 25 provided in the solution flow path 29 leading to the absorber A by bypassing the low temperature heat exchanger XL for the concentrated solution 25, Or it is set as valve V3 'provided in the refrigerant | coolant flow path 16 which guide | induces the vapor | steam generated by the said low temperature regenerator GL to the evaporator E or the absorber A. FIG.
In addition, as a capacity control method during the hot water single operation, a valve V5 that adjusts the amount of heat source input by the amount of solution introduced into the low temperature regenerator GL heating unit is provided. Using V5 as a three-way valve, when the hot water temperature is lower than the solution temperature, a solution flow path 30 may be provided to switch the solution introduction position in order to prevent heat from escaping to the external hot water 3. V5 may be a two-way valve that directly controls the spraying amount instead of the three-way valve, or may be a two-way valve that bypasses spraying and blows downward. Also, a method of controlling the spray amount by adjusting the rotation speed of the SP can be used. Further, when the hot water temperature is lower than the solution temperature, the warm water heat source 3 may be provided with a valve V6 that bypasses the low temperature regenerator GL.
[0015]
Further, in the heating cycle, in the system in which the refrigerant is condensed by the evaporator E, the solution temperature is higher than the condensation temperature by at least the boiling point rise, and the low temperature regenerator GL heats the solution from the hot water to the solution. And makes it difficult to generate steam.
For example, the relationship between the solution concentration and the equilibrium temperature of the solution is shown below using a LiBr aqueous solution as an example.
[Table 1]

[0016]
The hot water as exhaust heat has a maximum temperature of about 90 ° C. and is usually used up to about 80 ° C. During the cooling cycle, it is necessary to dilute a solution of about 55 wt% to 62 wt% to nearly 40 wt% during the heating cycle. For this reason, it is necessary to bring a large amount of dilution refrigerant into the apparatus.
In the present invention, the bypass pipe 31 is connected from the solution flow path 25 from the low-temperature regenerator GL, the valve V4 is provided in the bypass pipe, the solution is sprayed on the evaporator E, and the above relationship is changed. When the solution concentration in the low-temperature regenerator GL and the solution concentration sprayed on the evaporator E are substantially the same, the rise in boiling point can be almost eliminated.
[0017]
For example, when a 55 wt% LiBr aqueous solution is used,
Concentration 55wt%
Low temperature regenerator Saturation temperature (dew point) 40.4 ° C Solution temperature 75 ° C
Evaporator Saturation temperature (dew point) 35.4 ° C Solution temperature 69.2 ° C
In a simple explanation, when a 55 wt% solution is heated and boiled to 75 ° C. with warm water, steam with a saturation temperature of 40.4 ° C. is generated. And is absorbed into the 55 wt% solution of the evaporator. The solution temperature in that case is about 73 degreeC. The difference in saturation temperature is caused by the flow of steam, and this pressure difference is related to the size of the pipe V3 ′.
A certain amount of differential pressure is required to return the solution, and the valve size is selected, and in some cases, an orifice is inserted into the pipe to apply the differential pressure.
[0018]
【The invention's effect】
As described above, in the present invention, since only a low-temperature regenerator can be operated independently, it is possible to operate efficiently in the case of a low load of the absorption refrigeration apparatus, which is efficient in terms of energy and economy. Absorption refrigeration equipment could be provided.
[Brief description of the drawings]
FIG. 1 is a flow configuration diagram showing an example of an absorption refrigeration apparatus as a reference example for explaining the present invention.
FIG. 2 is a flow configuration diagram showing another example of an absorption refrigeration apparatus which is a reference example for explaining the present invention.
FIG. 3 is a flow configuration diagram showing an example of the absorption refrigeration apparatus of the present invention.
FIG. 4 is a flow configuration diagram showing another example of the absorption refrigeration apparatus of the present invention.

Claims

Absorber, low-temperature regenerator, high-temperature regenerator, condenser, evaporator, low-temperature solution heat exchanger, high-temperature solution heat exchanger, solution pump, refrigerant pump, and solution channel and refrigerant channel that connect these devices An absorption refrigeration apparatus using low potential energy and high potential energy as a heat source, wherein the solution channel and the refrigerant channel have a switching mechanism between a cooling cycle and a heating cycle, and the solution channel is a solution The dilute solution is flowed from the dilute solution branch point by the pump, partly to the low temperature regenerator, and the rest to the high temperature regenerator. The low temperature regenerator is generated by the heating mechanism with low potential energy and the high temperature regenerator. A heating mechanism using refrigerant vapor, and along the flow of the solution in the low-temperature regenerator, the heating mechanism using low-potential energy is upstream, and the heating mechanism using refrigerant vapor from the high-temperature regenerator is downstream. Provided in the flow path leading the dilute solution from the branch point to the high temperature regenerator, and a valve for controlling the amount of solution circulation is provided, and the valve has a small cooling / heating load and does not need to use high potential energy for the high temperature regenerator. In this case, a control mechanism for controlling the valve to close or close is provided, the high temperature regenerator is provided with a high potential energy adjustment mechanism, and the low temperature regenerator is provided with a low potential energy adjustment mechanism, It has a control mechanism that preferentially uses low potential energy and controls cooling capacity or heating capacity using high potential energy when the heat source is insufficient, and the low potential energy adjusting mechanism is a heating unit of the low temperature regenerator. An absorption refrigeration apparatus characterized by being a solution valve for adjusting a flow rate of a solution introduced into or sprayed into the container.