JP3729552B2 - Air conditioner - Google Patents

Air conditioner Download PDF

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JP3729552B2
JP3729552B2 JP06022896A JP6022896A JP3729552B2 JP 3729552 B2 JP3729552 B2 JP 3729552B2 JP 06022896 A JP06022896 A JP 06022896A JP 6022896 A JP6022896 A JP 6022896A JP 3729552 B2 JP3729552 B2 JP 3729552B2
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air conditioner
temperature
heat exchanger
refrigerant
indoor air
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JPH09229507A (en
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勇人 三平
裕明 宮崎
尚央 早川
康洋 小島
拓正 新町
周平 吉本
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Topre Corp
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Topre Corp
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/023—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
    • F25B2313/0231—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units with simultaneous cooling and heating
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2500/00—Problems to be solved
    • F25B2500/15—Hunting, i.e. oscillation of controlled refrigeration variables reaching undesirable values

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  • Compression-Type Refrigeration Machines With Reversible Cycles (AREA)

Description

【０００１】
【発明の属する技術分野】
本発明は、外調機と複数の室内空調機とからなり、ビル等の空気調和に用いられるマルチタイプの空気調和装置に関する。
【０００２】
【従来の技術】
ビル等の空気調和には、冷温水を熱源としてエアーハンドリングユニットやファンコイル等の空気調和装置が一般に用いられている。特に、定風量単一ダクト型エアーハンドリングユニットは、空調ゾーンに定風量の風を送り、給気温度を変えることにより空調ゾーンの室内温度を制御する空調機で、多くのビル等で採用されている。しかし、近年水質の悪化が激しく、これにより配管が腐食されるなどの問題が多く発生するようになり、できるだけ水の使用を控えたいという要望がでてきている。このような要望に対する回答として、例えば冷媒を直接熱源とするヒートポンプマルチ方式などが提案されている。
一方、近年の空気調和は多様化し、夏は冷房運転、冬は暖房運転といった単純なものではなくなっている。つまりビル等の内部では季節、部屋の方位や位置、ＯＡ機器等の負荷により空気調和システム内で冷房運転と暖房運転とを同時に行いたい場合がある。例えばビル内のインテリアゾーンでは冷房運転を、ペリメータゾーンでは暖房運転を行いたい場合がある。
【０００３】
また、春、秋の中間期には朝夕に暖房運転、昼間には冷房運転が求められる場合もある。そしてこの場合、冷房運転と暖房運転の切換時期が空調ゾーンの方角により異なり、南側では冷房運転に切り換わるべき条件に至っているのに、北側では依然暖房運転が維持される必要があることもある。
さらに、ＯＡ機器等の負荷の大きい所では、冬でも一日中冷房運転しなければならない場合もある。
そこでこの対策として４パイプ式エアーハンドリングユニットと呼ばれる冷却用熱交換器と加熱用熱交換器を持ち、冷房から暖房まで任意の温度で給気できる特殊な空調方式が採用される場合もある。
【０００４】
【発明が解決しようとする課題】
しかし、４パイプ式エアーハンドリングユニット方式は冷熱源と温熱源の２熱源を持たねばならず設備費用、運転費用ともに高額になる欠点があった。さらに、２熱源の廃熱はそれぞれ捨てられているため、省エネルギーに逆行するものとなる。
また、冷暖同時運転のできるヒートポンプマルチ方式は、室内機を居住区域に設置することになり、そのメンテナンス性が著しく低い。また、これは室内循環型の空気調和方式であるため、外気処理機能のために新たに外気処理装置を室内機ごとに設置しなければならず、高い設備コストを要するという問題がある。
【０００５】
さらに、冷暖同時運転に、同じモードの複数の室内機同志や、同じモードの室内機と室外機の間で、適正に冷媒の分配ができないこと、また、コンプレッサの容量制御も十分でないため吹き出し温度も室内機ごとにまちまちであることから、設定温度に達すると室内機の冷媒制御弁を閉じたりして機能を停止しているのが現状で、室温制御性が良いとは言いがたい。
【０００６】
また、ビル内での空調ゾーンの方位や位置、ＯＡ機器の偏在などにより負荷の異なる複数の空調ゾーンに対しては、それぞれ個別の室外機および室内機を設置しなければならないので、空調機の数が増加し、そのため設置スペースの増大となる。
さらに、冷暖同時型ヒートポンプマルチ方式においては、単にコンプレッサの容量制御を行っても送風温度の制御はできない。これは、冷暖同時運転型ヒートポンプマルチ方式では、室外機から複数の室内機まで冷媒配管距離がまちまちであり、圧力損失は冷媒流速の２乗に比例することから、コンプレッサの容量制御を行っても各室内機に到達する冷媒圧力分布が大きく変化し、各室内機の冷媒流量も変化してしまうからである。
【０００７】
また、定風量単一ダクト型エアーハンドリングユニットは空調ゾーンの室内温度を検出し、設定温度との差により給気温度を制御する。たとえば冷房運転時、室内温度が設定温度より高い場合は給気温度を一定量下げ、室内温度が低い場合は給気温度を一定量上げるステップ制御を行っている。しかし、差が大きい場合は室内温度が設定温度となるまでに長時間を要したり、給気温度の変化量が大きすぎるとコールドドラフトを起こしたり、室内温度がハンチングを起こしたりする。
さらに、起動時の給気温度は予め設定された温度であり、空調ゾーンの負荷を考慮にいれたものではないため、負荷が大きい場合は設定温度になるまで当然時間がかかることになり、冬期の朝など早急な立ち上がりを望む要望には応えられないという問題があった。
【０００８】
したがって、本発明は、上記従来の問題点に鑑み、外調機と複数の室内空調機を備える空気調和装置において、高い設備コストを要することなく、個々の空調ゾーンにおいて、その要求負荷に応じて個別に冷房運転または暖房運転ができる空気調和装置、さらには、個別に給気温度を任意の温度に変化できるようにし、省エネルギー性にも優れた空気調和装置を提供することを目的とする。
【０００９】
【課題を解決するための手段】
このため、本発明は、熱交換器、該熱交換器に付設された膨張弁、該膨張弁の手前に設けられた流量調整手段、および冷媒の温度と圧力の値より該流量調整手段を制御する第１の制御手段を備える外調機と、それぞれ熱交換器、該熱交換器に付設された膨張弁、該膨張弁の手前に設けられた流量調整手段、および冷媒の温度と圧力の値より該流量調整手段を制御する第２の制御手段を備え、冷凍サイクルの液管と高圧ガス管と低圧ガス管を形成する冷媒配管により外調機に並列に接続された複数の室内空調機からなり、各室内空調機の給気を各空調ゾーンごとに導くとともに、外調機の熱交換器に接続されたガス管を該外調機の熱交換器に向かう高圧ガス管または低圧ガス管に選択的に接続可能の第１の切り換え手段と、各室内空調機の熱交換器に接続されたガス管を前記高圧ガス管または低圧ガス管に選択的に接続可能の第２の切り換え手段を有して、それぞれの室内空調機を個別に冷房運転または暖房運転に選択的に制御し、その給気温度を変更することによりそれぞれの空調ゾーンの室内温度を制御するように構成されたものとした。
【００１０】
上記室内空調機の第２の制御手段は、冷房運転時には当該室内空調機の膨張弁にはいる冷媒の過冷却度を給気温度に応じて変化させるように当該室内空調機の流量調整手段を制御し、暖房運転時は当該室内空調機の熱交換器を出た冷媒の過冷却度を給気温度に応じて変化させるように当該室内空調機の流量調整手段を制御するものとするのが望ましい。
また、外調機の第１の制御手段は、外調機の熱交換器が凝縮器として作用するときは該外調機の熱交換器を出る冷媒の過冷却度が該熱交換器の負荷に応じて決定される値になるように前記外調機の流量調整手段を制御し、外調機の熱交換器が蒸発器として作用するときは外調機の膨張弁にはいる冷媒の過冷却度が外調機の熱交換器の負荷に応じて決定される値になるよう前記外調機の流量調整手段を制御するものとするのが望ましい。
【００１１】
さらに、室内空調機の少なくとも１つにおいて該熱交換器が蒸発器として作用するとき前記室内空調機に向かう液管と外調機に向かう低圧ガス管の間に、互いの間で熱交換を行う第１の過冷却熱交換器を設けるのが好ましく、また、外調機の熱交換器が蒸発器として作用するとき前記外調機の熱交換器に向かう液管と低圧ガス管の間に、互いの間で熱交換を行う第２の過冷却熱交換器を設けるのが好ましい。
また、上記給気温度は、室内空調機が起動時にはそれぞれの空調ゾーンの室内温度と設定温度より決定される値に設定され、その後は設定温度と室内温度により決定される値とその室内温度の変化による補正値によって決定される値に基づいて変更されるのが望ましい。
【００１２】
【作用】
各室内空調機から各空調ゾーンへダクトを介して給気し、各室内空調機の給気温度の変化でそれぞれの空調ゾーンごとの室内温度調節が行われる。外調機および室内空調機において、第１、第２の制御手段がそれぞれの膨張弁手前に配置された流量調整弁を用いて給気すべき温度になるように過冷却度を制御するとともに、各室内空調機と外調機の熱交換器のガス管を高圧ガス管または低圧ガス管と選択的に接続することにより、冷房運転と暖房運転が同時的に混在する形でどの室内空調機もいずれかを選択できる。
また、冷暖同時運転時には、室内空調機間で熱エネルギーの移動が行われ大幅な省エネルギーとなる。
【００１３】
さらに、室内空調機の第２の制御手段は、室内温度に応じて決定される給気温度になるように流量調整手段により冷媒の過冷却度を制御することにより、給気温度が変化されても他の室内空調機との干渉を生じないでそれぞれの室内空調機において、膨張弁に入る冷媒の圧力を安定に保持でき、給気温度の安定した空気調和が行われる。
【００１４】
なお、複数の室内空調機に向かう液管と低圧ガス管の間に第１の過冷却熱交換器を設けたときには、流量調整手段による流量の制御幅が拡大される。さらに、外調機の熱交換器に向かう液管と低圧ガス管の間に第２の過冷却熱交換器を設けたときは、外調機のコンプレッサに入るガス冷媒の過熱度を大きくすることができ、暖房能力が向上する。
【００１５】
【発明の実施の形態】
図１は、本発明の第１の実施例のシステム構成を示す。この実施例においては、１機の外調機３０に対して、３機の室内空調機５０Ａ、５０Ｂ、５０Ｃが分岐ユニット４０を介して並列に接続されている。各室内空調機からは熱交換された空気がダクト４７Ａ、４７Ｂ、４７Ｃにより空調ゾーンＺＡ、ＺＢ、ＺＣへ導かれる。各ダクトは対応する空調ゾーンの数に応じて適宜に分岐し、個別に空調ゾーンへ分かれて送られる。４５Ａ、４５Ｂ、４５Ｃは室内温度センサで、４９Ａ、４９Ｂ、４９Ｃは室内温度設定器でそれぞれ室内空調機５０Ａ、５０Ｂ、５０Ｃへ接続されている。
なお、「外調機」は、以下に詳述するように、室内空調機での利用に備えて冷媒処理を行なう、いわゆる室外機の別名として使用している（以下、本願において同じ）。
【００１６】
図２は本実施例の冷媒回路を示す。３機の室内空調機５０Ａ、５０Ｂ、５０Ｃは分岐ユニット４０を介して、液管、低圧ガス管および高圧ガス管を形成する冷媒配管Ｒ１、Ｒ２、Ｒ３により、外調機３０に対して並列に接続されている。
外調機３０は、能力可変のコンプレッサ１と熱交換器６を備える。コンプレッサ１の吐出側と吸い込み側の配管には、それぞれ圧力センサ１１Ａ、１１Ｂが設けられている。
熱交換器６には、送風機２１が付設されるとともに、両端にはそれぞれ温度センサ１０Ａ、１０Ｂが設けられている。
【００１７】
外調機３０には、さらに過冷却熱交換器４が備えられ、過冷却熱交換器４側から熱交換器６方向に順に電子式の流量調整弁２５、冷媒温度検出のための温度センサ９、圧力センサ８、電子式の膨張弁７が設置されている。
過冷却熱交換器４の他端は、液タンク２７を介して冷媒配管Ｒ１に接続されている。熱交換器６の他端側の冷媒配管（ガス管）は、電磁弁５Ａを介して過冷却熱交換器４の熱交換通路の入口に接続されるとともに、電磁弁５Ｂを介して冷媒配管Ｒ３に接続されている。上記過冷却熱交換器４の熱交換通路の出口は冷媒配管Ｒ２に接続されている。冷媒配管Ｒ２はまたアキュムレータ３に接続され、冷媒配管Ｒ３はコンプレッサ１の吐出側に接続されている。
【００１８】
分岐ユニット４０は過冷却熱交換器１２を備える。過冷却熱交換器１２は冷媒配管Ｒ１により外調器３０の液タンク２７と接続されている。また、過冷却熱交換器１２の出口は室内空調機５０Ａ、５０Ｂ、５０Ｃに分岐され接続されている。
さらに、分岐ユニット４０には、電磁弁１３Ａ、１３Ｂ、１３Ｃ、２３Ａ、２３Ｂ、２３Ｃが備えられ、電磁弁１３Ａ、１３Ｂ、１３Ｃはそれぞれ室内空調機５０Ａ、５０Ｂ、５０Ｃを過冷却熱交換器１２のもう一方の冷媒配管Ｒ２系統に連通可能とし、電磁弁２３Ａ、２３Ｂ、２３Ｃはそれぞれの室内空調機５０Ａ、５０Ｂ、５０Ｃを冷媒配管Ｒ３に連通可能とする。
【００１９】
室内空調機５０Ａは、熱交換器１８Ａと、これに付設された送風機２４Ａを備える。熱交換器１８Ａの一方の端は、分岐ユニット４０の過冷却熱交換器１２のＲ１系統に接続され、他端方は分岐ユニット４０の電磁弁１３Ａと２３Ａに接続される。
上記熱交換器１８Ａの一端側のＲ１配管には、過冷却熱交換器１２側から熱交換器１８Ａ方向に順に電子式の流調調整弁１４Ａ、冷媒温度検出のための温度センサ１７Ａ、圧力センサ１６Ａ、電子式の膨張弁１５Ａが設けられている。
【００２０】
また、熱交換器１８Ａには、それぞれ室内空調機の給気温度と還気温度を検出する温度センサ２２Ａと２６Ａが付設されているとともに、両端には冷媒温度を検出する温度センサ１９Ａ、２０Ａが設けられている。
熱交換器１８Ａで熱交換され、送風機２４Ａにより吹き出される給気は、図１に示したようにダクト４７Ａにより空調ゾーンＺＡへ導かれる。
室内空調機５０Ｂ、５０Ｃも室内空調機５０Ａと同じ構成を有し、以降、それぞれ参照番号にＢ、Ｃを付して示す。
【００２１】
図３は、上記室内空調機および外調機における制御装置を示す。制御装置は室内空調機および外調機ともにマイクロコンピュータおよびその周辺機器からなる。
外調機制御部３１には、コンプレッサ１用のインバータ３２、外調機の送風機２１用のインバータ３３が接続されている。
また、周辺機器として、膨張弁７の駆動制御部３４、流調調整弁２５の駆動制御部４８、電磁弁５Ａ、５Ｂの駆動制御部３５、温度センサ９、１０Ａ、１０Ｂのための温度変換器３６、圧力センサ８、１１Ａ、１１Ｂのための圧力変換器３７が外調機制御部３１に接続されている。
【００２２】
一方、室内空調機５０Ａの制御装置は、室内空調機制御部５１Ａとこれに接続された給気温度設定部４６Ａとを備える。
室内空調機制御部５１Ａには、周辺機器として、膨張弁１５Ａの駆動制御部３９Ａ、流量調整弁１４Ａの駆動制御部４１Ａ、各温度センサ１７Ａ、１９Ａ、２０Ａ、２２Ａおよび２６Ａのための温度変換器４２Ａ、圧力センサ１６Ａのための圧力変換器４３Ａ、電磁弁１３Ａ、２３Ａのための駆動制御部４８Ａ、ならびに温度変換器４４Ａが接続されている。温度変換器４４Ａには空調ゾーンの室内温度を検出する温度センサ４５Ａと検出された温度を保持する温度保持部５２Ａが接続されている。給気温度設定部４６Ａは、室温設定器４９Ａから入力された設定室内温度に基づいて給気温度を演算し、保持する。
室内空調機５０Ｂ、５０Ｃにおける制御装置についても同様に構成され、室内空調機制御部５１Ｂ、５１Ｃ、そのほか、それぞれ参照番号にＢおよびＣを付して示す。
【００２３】
外調機制御部３１と各室内空調機制御部５１Ａ、５１Ｂ、５１Ｃは、通信手段によって結ばれ、外調機制御部３１は各室内空調機制御部５１Ａ、５１Ｂ、５１Ｃの状況を常時知ることができる。
外調機制御部３１は、上記室内空調機制御部５１Ａ、５１Ｂ、５１Ｃから送られてきた室内空調機の負荷量を運転モード別に積算し、大きい方の運転モードの負荷量に相当する制御信号をコンプレッサ１用のインバータ３２に送出する。インバータ３２は、この制御信号に従いコンプレッサ１を駆動する。
また、外調機制御部３１は、外調機の熱交換器６が前記の全室内空調機の負荷量の小さい方の運転モードと同じモードになるよう、すなわち、冷房運転の負荷の方が小さい時は外調機３０の熱交換器６が蒸発器として、また暖房運転の負荷の方が小さい時は凝縮器として働くように周辺機器を制御する。
【００２４】
室内空調機制御部５１Ａ、５１Ｂ、５１Ｃは温度センサ４５Ａ、４５Ｂ、４５Ｃより空調ゾーンの室内温度を検出して、それぞれの温度保持部５２Ａ、５２Ｂ、５２Ｃに保持させる。そして、起動時は給気温度設定部４６Ａ、４６Ｂ、４６Ｃは室温設定器４９Ａ、４９Ｂ、４９Ｃから入力された設定室内温度と温度センサ４５Ａ、４５Ｂ、４５Ｃで求めた検出室内温度の差に基づいて、図４で示される関係表より給気温度を決定し、保持する。図４では、設定室内温度と検出室内温度の差に従って検出室内温度（室温）を中心に直線的に変化する給気温度が求められるようになっている。
【００２５】
次に還気温度センサ２６Ａ、２６Ｂ、２６Ｃで検出した温度データと給気温度設定部４６Ａ、４６Ｂ、４６Ｃの温度データとの差を演算し、それぞれの室内空調機５０Ａ、５０Ｂ、５０Ｃが冷房運転か暖房運転かの運転モードを決定する。そして、室内空調機の給気温度が室内空調機の還気温度や湿度に影響されるため、それらを勘案した負荷増減量を加え、コンプレッサ１の出力に相当する負荷量を室内空調機の運転モードとともに外調機制御部３１に送る。
【００２６】
起動からあらかじめ設定された給気温度変更時間が経過するまでの間は、上記初期決定された給気温度に基づいて制御が行なわれる。給気温度変更時間はシステム全体の規模やその他の条件を勘案して決められるが、通常起動から５〜３０分程度の範囲で設定される。
室内空調機制御部５１Ａ、５１Ｂ、５１Ｃは上記給気温度変更時間が経過するたびに室内温度を検出し、この検出室内温度と室温設定器４９Ａ、４９Ｂ、４９Ｃの設定室内温度との差を演算するとともに、室内温度保持部５２Ａ、５２Ｂ、５２Ｃの温度と比較し、室内温度が上昇しているか下降しているか、あるいは変化がないのかを判断する。そして、この室内温度の変化状態に応じて給気温度の変更量を決定する。
【００２７】
図５は給気温度の変更量決定に用いられるグラフで、検出室内温度と設定室内温度との差に対する給気温度の変更量の関係が直線で示されている。（ａ）は室内温度が上昇している場合、（ｂ）は室内温度が変化していない場合、（ｃ）は室内温度が下降している場合に適用され、（ａ）では（ｂ）に比べて直線が低減方向へシフトしており、検出室内温度と設定室内温度との差が０でも給気温度を所定量下げるようになっている。また、（ｃ）では（ｂ）に比べて直線が増大方向へシフトしており、検出室内温度と設定室内温度との差が０でも給気温度を所定量上げるようになっている。
【００２８】
室内空調機制御部５１Ａ、５１Ｂ、５１Ｃは、こうして決定された給気温度を給気温度設定部４６Ａ、４６Ｂ、４６Ｃに保持させる。
また、電磁弁５Ａと５Ｂ、１３Ａと２３Ａ、１３Ｂと２３Ｂ、１３Ｃと２３Ｃはそれぞれ一方が開状態の時、他方は閉状態となるよう制御される。ただし、室内空調機が運転の必要がない場合は双方とも閉状態となる。
【００２９】
つぎに、上記構成における作動について説明する。
図６は、すべての室内空調機が冷房運転される全冷房運転時の冷媒の流れを示す。
全ての室内空調機が冷房運転されるときには、外調機においては電磁弁５Ｂが開状態、電磁弁５Ａが閉状態となり、分岐ユニットにおいては電磁弁１３Ａ、１３Ｂ、１３Ｃがそれぞれ開状態、２３Ａ、２３Ｂ、２３Ｃが閉状態となるよう制御される。外調機の熱交換器６は凝縮器、各室内空調機の熱交換器１８Ａ、１８Ｂ、１８Ｃは蒸発器として作用する。
【００３０】
すなわち、外調機３０において、コンプレッサ１からの高圧ガス冷媒は、矢示のように電磁弁５Ｂを通り、熱交換器６で液化する。それから過冷却熱交換器４と液タンク２７を経て、冷媒配管Ｒ１で分岐ユニット４０の過冷却熱交換器１２へ入る。冷媒は、過冷却熱交換器１２で各室内空調機５０Ａ、５０Ｂ、５０Ｃの熱交換器１８Ａ、１８Ｂ、１８Ｃから出てきたガス冷媒と熱交換され、過冷却度が増大した液冷媒となる。
【００３１】
さらに、冷媒は分岐配管により分岐され、各流量調整弁１４Ａ、１４Ｂ、１４Ｃに並列に入り、続いて膨張弁１５Ａ、１５Ｂ、１５Ｃにより減圧されて、低温の気液混合状態になる。
つぎに、冷媒は熱交換器１８Ａ、１８Ｂ、１８Ｃにおいて還気と熱交換され、ガス状の冷媒となる。そして、電磁弁１３Ａ、１３Ｂ、１３Ｃを経て過冷却熱交換器１２へ戻り、外調機３０から冷媒配管Ｒ１より入ってくる液冷媒を冷却する。過冷却熱交換器１２を出た冷媒は、冷媒配管Ｒ２を経て、外調機３０のコンプレッサ１に戻る。
流量調整弁１４Ａ、１４Ｂ、１４Ｃが発明の室内空調機の流量調整手段を構成し、過冷却熱交換器１２が発明の第１の過冷却熱交換器を構成している。
【００３２】
この間における外調機３０の膨張弁７、流量調整弁２５、送風機２１、各室内空調機５０Ａ、５０Ｂ、５０Ｃの流量調整弁１４Ａ、１４Ｂ、１４Ｃ、膨張弁１５Ａ、１５Ｂ、１５Ｃの制御は以下のように行われる。
まず、外調機制御部３１により膨張弁７は全開状態に保持される。つぎに、外調機制御部３１は、圧力センサ８で冷媒の圧力を検出し、流量調整弁２５に入る冷媒の飽和温度を演算する。そして、温度センサ９で検出した温度との差、つまり過冷却度が、あらかじめ定めた外調機の負荷と過冷却度の関係式の演算から求めた値になるよう流量調整弁２５を制御する。この外調機の負荷と過冷却度レベルの関係式は演算式によるほか、例えば図７に示されるようなレベルＣ１〜Ｃ１０を示すグラフ形式で記憶され、これから読みとるようにされる。
【００３３】
また、コンプレッサ１の吐出側圧力センサ１１Ａにより検出される圧力が予め設定された値になるよう、例えばＰＩＤ制御、あるいはステップ制御などによる信号が送風機用のインバータ３３へ出力され、送風機２１が駆動されて風量を制御する。
【００３４】
一方、室内空調機制御部５１Ａ、５１Ｂ、５１Ｃでは、温度センサ２２Ａ、２２Ｂ、２２Ｃで検出した給気温度が、先に求めて給気温度設定部４６Ａ、４６Ｂ、４６Ｃに保持されている温度となるに必要な過冷却度を演算する。
つぎに、圧力センサ１６Ａ、１６Ｂ、１６Ｃで冷媒の圧力を検出し、各膨張弁１５Ａ、１５Ｂ、１５Ｃに入る冷媒の飽和温度を演算し、温度センサ１７Ａ、１７Ｂ、１７Ｃで検出した温度との差を演算して実際の過冷却度を求める。
そして、必要な過冷却度になるように流量調整弁１４Ａ、１４Ｂ、１４Ｃを制御する。
つまり検出した給気温度が給気温度設定部４６Ａ、４６Ｂ、４６Ｃに保持されている温度より高い場合は冷媒の過冷却度を大きくするよう流量調整弁１４Ａ、１４Ｂ、１４Ｃを制御し、検出温度が保持されている温度より低い場合は過冷却度を小さくするよう流量調整弁１４Ａ、１４Ｂ、１４Ｃを制御することになる。
【００３５】
さらに、温度センサ１９Ａ、１９Ｂ、１９Ｃ、２０Ａ、２０Ｂ、２０Ｃの各検出温度により、熱交換器１８Ａ、１８Ｂ、１８Ｃの入り口と出口の冷媒の温度差、つまり過熱度が一定になるように、膨張弁１５Ａ、１５Ｂ、１５Ｃを制御する。
ここで、各室内空調機５０Ａ、５０Ｂ、５０Ｃの負荷が同等であれば、各流量調整弁１４Ａ、１４Ｂ、１４Ｃの開度は互いに同じとなる。この場合、冷媒は分岐ユニット４０から各室内空調機５０Ａ、５０Ｂ、５０Ｃに均等に分配され、給気温度は互いに同じとなる。
【００３６】
ここで、例えば、室内空調機５０Ａの負荷が重くて給気温度が低く設定され、室内空調機５０Ｂおよび５０Ｃの負荷が軽くて給気温度が高く設定されたとする。
すると室内空調機５０Ａの室内空調機制御部５１Ａは、外調機制御部３１へ負荷量を増加させるべき信号を送り、室内空調機５０Ｂ、５０Ｃの室内空調機制御部５１Ｂ、５１Ｃは、外調機制御部３１へ負荷量を減少させるべき信号を送る。これに対応して外調機制御部３１は各室内空調機制御部からの負荷量を総和しコンプレッサ１の出力を上昇させるか減少させるかを判断し、制御する。
【００３７】
また、室内空調機制御部５１Ａは過冷却度を大きくするよう設定され、室内空調機制御部５１Ｂ、５１Ｃは過冷却度を小さくするよう設定され、それぞれの流量調整弁１４Ａ、１４Ｂ、１４Ｃは変更された過冷却度となるよう開度を制御する。
【００３８】
ここで、膨張弁１５Ａ、１５Ｂ、１５Ｃは熱交換器１８Ａ、１８Ｂ、１８Ｃの過熱度を一定にするだけで、給気温度や冷媒流量を直接制御していないが、膨張弁１５Ａ、１５Ｂ、１５Ｃに入る冷媒の過冷却度を変えるように流量調整弁１４Ａ、１４Ｂ、１４Ｃの開度を制御することにより、膨張弁１５Ａ、１５Ｂ、１５Ｃの入口の圧力が制御され、熱交換器１８Ａ、１８Ｂ、１８Ｃを流れる冷媒流量が変化して、それに伴い熱交換量も変化するので、給気温度が制御される。
図８は上記の制御要領を示す冷凍サイクルのモリエル線図である。図中、（ａ）は流量調整弁１４Ａ、１４Ｂ、１４Ｃによる圧力降下、（ｂ）は制御された過冷却度、（ｃ）は膨張弁１５Ａ、１５Ｂ、１５Ｃによる圧力降下分を示し、（ｄ）は過冷却熱交換器１２による過冷却部分である。
【００３９】
なお、分岐ユニット４０は過冷却熱交換器１２を備えているので、各流量調整弁１４Ａ、１４Ｂ、１４Ｃに入る液冷媒の過冷却度を大きくでき、流量調整弁の開度を小さく絞り込んでも冷媒が膨張し始めることがないから、流量調整弁の制御幅が拡大される。
【００４０】
また、この過冷却熱交換器１２は、戻りの冷媒を完全にガス化するのにも役立つ。すなわち、全ての室内空調機５０Ａ、５０Ｂ、５０Ｃの給気が何らかの問題で風量が急減した場合に、膨張弁１５Ａ、１５Ｂ、１５Ｃの制御速度が追いつかず熱交換器１８Ａ、１８Ｂ、１８Ｃで蒸発しきれなかった液冷媒が流れても、過冷却熱交換器１２が一時的な蓄熱器として働くので、液冷媒がコンプレッサ１に入る液圧縮現象の発生が防止できる。
同じく、過冷却熱交換器１２によりコンプレッサ１のガス冷媒の過熱度を確保できるので、各室内空調機５０Ａ、５０Ｂ、５０Ｃの膨張弁１５Ａ、１５Ｂ、１５Ｃによる過熱度を小さく設定でき、熱交換器１８Ａ、１８Ｂ、１８Ｃの利用効率を上げることができる。
【００４１】
つぎに、全ての室内空調機が暖房運転される全暖房運転時の冷媒の流れを図９を参照して説明する。
全ての室内空調機が暖房運転されるときには、外調機においては電磁弁５Ａが開状態、電磁弁５Ｂが閉状態となり、分岐ユニットにおいては電磁弁２３Ａ、２３Ｂ、２３Ｃが開状態となり、電磁弁１３Ａ、１３Ｂ、１３Ｃが閉状態となるよう制御される。外調機の熱交換器６は蒸発器、各室内空調機の熱交換器１８Ａ、１８Ｂ、１８Ｃが凝縮器として作用する。
【００４２】
すなわち、外調機３０のコンプレッサ１からの高圧ガス冷媒は、冷媒配管Ｒ３を経て、分岐ユニット４０に入る。冷媒はここで分岐され、電磁弁２３Ａ、２３Ｂ、２３Ｃを通って、各室内空調機５０Ａ、５０Ｂ、５０Ｃの熱交換器１８Ａ、１８Ｂ、１８Ｃに入って液化される。
このあと、分岐ユニットの過冷却熱交換器１２を経て、冷媒配管Ｒ１で外調機３０に戻り、液タンク２７を経て過冷却熱交換器４に入る。
冷媒は、過冷却熱交換器４において熱交換器６からのガス冷媒と熱交換され、過冷却度が増大した液冷媒となる。
【００４３】
さらに、冷媒は膨張弁７により減圧され、低温の気液混合状態になり熱交換器６に入る。冷媒は熱交換器６で室外空気と熱交換されてガス状となり、電磁弁５Ａを経て過冷却熱交換器４へ進む。ここで前述のように液タンク２７からきた液冷媒を冷却するとともに、自らは過熱度の増したガス冷媒となる。このあと、冷媒はアキュムレーター３を経てコンプレッサ１に戻る。
ここでは、過冷却熱交換器４が発明の第２の過冷却熱交換器を構成している。
【００４４】
この間における膨張弁１５Ａ、１５Ｂ、１５Ｃ、流量調整弁２５、送風機２１、流量調整弁１４Ａ、１４Ｂ、１４Ｃ、膨張弁７の制御は以下のように行われる。 まず、各室内空調機制御部５１Ａ、５１Ｂ、５１Ｃにより、膨張弁１５Ａ、１５Ｂ、１５Ｃは全開に保持される。つぎに、外調機制御部３１は、圧力センサ８で冷媒の圧力を検出し、膨張弁７に入る冷媒の飽和温度を演算する。そして、温度センサ９で検出した温度との差、つまり過冷却度を外調機の負荷と過冷却度の関係式から求めた過冷却度になるように流量調整弁２５を制御する。上記関係式は図１０のように負荷に応じてレベルＤ１〜Ｄ１０で示される過冷却度を与える。
また、コンプレッサ１の圧力センサ１１Ｂにより検出される圧力が予め設定された値になるよう、例えばＰＩＤ制御、あるいはステップ制御などによる信号が送風機用インバータ３３に出力され、送風機２１が駆動されて風量を制御する。
【００４５】
一方、室内空調機制御部５１Ａ、５１Ｂ、５１Ｃでは、温度センサ、２２Ａ、２２Ｂ、２２Ｃで検出した給気温度が、先に求めて給気温度設定部４６Ａ、４６Ｂ、４６Ｃに保持されている温度となるに必要な過冷却度を演算する。
つぎに、圧力センサ１６Ａ、１６Ｂ、１６Ｃで冷媒の圧力を検出し、各流量調整弁１４Ａ、１４Ｂ、１４Ｃに入る冷媒の飽和温度を演算して、この飽和温度と温度センサ１７Ａ、１７Ｂ、１７Ｃで検出した温度との差を演算して実際の過冷却度を求める。
つまり、検出した給気温度が給気温度設定部４６Ａ、４６Ｂ、４６Ｃに保持されている温度より高い場合は過冷却度を大きくするよう流量調整弁１４Ａ、１４Ｂ、１４Ｃを制御し、検出温度が保持されている温度より低い場合は過冷却度を小さくするよう流量調整弁１４Ａ、１４Ｂ、１４Ｃを制御する。
【００４６】
また、外調機制御部３１では温度センサ１０Ａ、１０Ｂの検出温度に基づいて、冷房運転時の室内空調機と同様に、熱交換器６の過熱度が一定に保持されるよう膨張弁７を制御する。
ここで、各室内空調機５０Ａ、５０Ｂ、５０Ｃの負荷が同等であれば、各流量調整弁１４Ａ、１４Ｂ、１４Ｃの開度は互いに同じとなる。この場合、冷媒は分岐ユニット４０から各室内空調機５０Ａ、５０Ｂ、５０Ｃに均等に分配され、給気温度は互いに同じとなる。
【００４７】
ここで、例えば、室内空調機５０Ａの負荷が重くて給気温度が高く設定され、室内空調機５０Ｂおよび５０Ｃの負荷が軽くて給気温度が低く設定されたとする。
すると室内空調機５０Ａの室内空調機制御部５１Ａは、外調機制御部３１へ負荷量を増加させるべき信号を送り、室内空調機５０Ｂ、５０Ｃの室内空調機制御部５１Ｂ、５１Ｃは、外調機制御部３１へ負荷量を減少させるべき信号を送る。これに対応して外調機制御部３１は各室内空調機制御部からの負荷量を総和しコンプレッサ１の出力を上昇させるか減少させるかを判断し、制御する。
【００４８】
また、室内空調機制御部５１Ａは過冷却度を小さくするよう設定され、室内空調機制御部５１Ｂ、５１Ｃは過冷却度を大きくするよう設定され、それぞれの流量調整弁１４Ａ、１４Ｂ、１４Ｃは変更された過冷却度となるよう開度を制御する。
図１１は上記の制御要領を示す冷凍サイクルのモリエル線図である。図中、（ａ）は膨張弁１５Ａ、１５Ｂ、１５Ｃによる圧力降下、（ｂ）は過冷却熱交換器１２による過冷却部分、（ｃ）は流量調整弁１４Ａ、１４Ｂ、１４Ｃによる圧力降下分を示し、（ｄ）は制御された過冷却度である。
【００４９】
なお、この暖房運転では、過冷却度を流量調整弁で制御するので、過冷却度が大きくなって熱交換器１８Ａ、１８Ｂ、１８Ｃ内に液冷媒が多く溜まり冷凍サイクル全体が冷媒不足を起こすような不具合現象の発生が防止される。
さらに、外調機の過冷却熱交換器４は、戻りの冷媒を完全に液化するのに役立つ。すなわち、室内空調機５０Ａ、５０Ｂ、５０Ｃの給気が何らかの問題で風量が急減した場合に、流量調整弁１４Ａ、１４Ｂ、１４Ｃの制御速度が追いつかず、外調機３０に未凝縮のガス冷媒が流れても、過冷却熱交換器４が一時的な蓄熱器として働くので、ガス冷媒が膨張弁７に入ることによる制御性の低下が防止できる。また、外調機３０の送風機２１の制御により一時的に風量が減って未蒸発の液冷媒がコンプレッサ１に流れることがあっても同様に防止できる。
同じく、過冷却熱交換器４によりコンプレッサ１に入るガス冷媒の過熱度を大きくすることができるので、コンプレッサ１の吐出温度が高くなり、その分暖房能力が向上する。
【００５０】
次に、冷房運転と暖房運転が平行して行われ、室内空調機の負荷が暖房運転より冷房運転の方が大きい冷暖同時冷房主運転の作動について説明する。図１２はこのときの冷媒の流れを示す。ここでは、たとえば一例として室内空調機５０Ａが暖房運転、室内空調機５０Ｂ、５０Ｃが冷房運転されているものとする。
まず、外調機では電磁弁５Ｂが開状態、電磁弁５Ａが閉状態となり、分岐ユニットでは電磁弁２３Ａ、１３Ｂ、１３Ｃが開状態、電磁弁１３Ａ、２３Ｂ，２３Ｃが閉状態となるよう制御される。
外調機の熱交換器６と室内空調機１８Ａは凝縮器、室内空調機の熱交換器１８Ｂ、１８Ｃは蒸発器として作用する。
【００５１】
外調機３０において、コンプレッサ１からの高圧ガス冷媒は、電磁弁５Ｂから熱交換器６に入りここで液化される。熱交換器６を出た冷媒は過冷却熱交換器４と液タンク２７を経て冷媒配管Ｒ１で分岐ユニット４０の過冷却熱交換器１２へ入る。
コンプレッサ１からの高圧ガス冷媒はまた、冷媒配管Ｒ３によって分岐ユニット４０に入る。冷媒配管Ｒ３経由の冷媒は電磁弁２３Ａを経て室内空調機５０Ａの熱交換器１８Ａに入りここで液化する。
【００５２】
冷媒配管Ｒ１経由で分岐ユニットの過冷却熱交換器１２に入った冷媒は、室内空調機５０Ｂ、５０Ｃの熱交換器１８Ｂ、１８Ｃから出てきたガス冷媒と熱交換され過冷却度が増大した液冷媒となる。
この冷媒は分岐配管により室内空調機５０Ａの熱交換器１８Ａからきた液冷媒と一旦合流した後、室内空調機５０Ｂ、５０Ｃに並列に入る。ここでは、それぞれ流量調整弁１４Ｂ、１４Ｃ、続いて膨張弁１５Ｂ、１５Ｃにより減圧されて低温の気液混合状態になって、熱交換器１８Ｂ、１８Ｃに入る。
【００５３】
冷媒は熱交換器１８Ｂ、１８Ｃにおいて還気と熱交換され、ガス状の冷媒となる。そして、電磁弁１３Ｂ、１３Ｃを経て過冷却熱交換器１２へ戻り、外調機３０から冷媒配管Ｒ１経由で入ってくる液冷媒を冷却する。
過冷却熱交換器１２を出た冷媒は、冷媒配管Ｒ２を経て外調機３０のコンプレッサ１に戻る。
【００５４】
この間における外調機３０の膨張弁７、流量調整弁２５、送風機２１、室内空調機５０Ａの流量調整弁１４Ａ、膨張弁１５Ａ、室内空調機５０Ｂ、５０Ｃの流量調整弁１４Ｂ、１４Ｃ、膨張弁１５Ｂ、１５Ｃの制御は以下のように行われる。
まず、外調機制御部３１の膨張弁７は全開状態に保持される。流量調整弁２５は、冷房運転時の制御と同様に、圧力センサ８と温度センサ９より演算した過冷却度が、図７で求められる過冷却度になるように制御される。
【００５５】
また、送風機２１については、全冷房運転の制御と同様に、吐出側圧力センサ１１Ａにより検出される圧力が予め設定された値になるようインバータ３３を駆動させて、その風量制御が行われる。
一方、室内空調機５０Ａの室内空調機制御部５１Ａでは膨張弁１５Ａを全開に保持する。そして、流量調整弁１４Ａは、全暖房運転時の室内空調機の流量調整弁の制御と同様に、設定された給気温度に基づいて必要な過冷却度となるよう制御される。
【００５６】
また、室内空調機５０Ｂ、５０Ｃの室内空調機制御部５１Ｂ、５１Ｃでは、膨張弁１５Ｂ、１５Ｃが、全冷房運転時の室内空調機機の膨張弁の制御と同様に、過熱度が一定になるよう制御され、流量調整弁１４Ｂ、１４Ｃはこれもまた同じく、設定された給気温度に基づいて必要な過冷却度となるよう制御される。
なお、それぞれの室内空調機の負荷が変化した場合は、全冷房運転または全暖房運転における同じ運転モードの室内空調機と同様であるから説明を省略する。
図１３は上記の制御要領を示す冷凍サイクルのモリエル線図である。図中、（ａ）は外調機または室内空調機５０Ａの流量調整弁により制御される過冷却度、（ｂ）は外調機または室内空調機５０Ａの流量調整弁による圧力降下、（ｃ）は過冷却熱交換器１２による過冷却部分、（ｄ）は室内空調機５０Ｂまたは５０Ｃの流量調整弁による圧力降下、（ｅ）は室内空調機５０Ｂまたは５０Ｃの流量調整弁により制御される過冷却度、（ｆ）は室内空調機５０Ｂまたは５０Ｃの膨張弁による圧力降下である。
【００５７】
つぎに、冷暖同時運転で、室内空調機の負荷が冷房運転より暖房運転の方が大きい冷暖同時暖房主運転の作動について、冷媒の流れを示す図１４を参照して説明する。ここでは、たとえば一例として室内空調機５０Ａが冷房運転、室内空調機５０Ｂ、５０Ｃが暖房運転されるものとする。
まず、外調機では電磁弁５Ａが開状態、電磁弁５Ｂが閉状態となり、分岐ユニットでは電磁弁１３Ａ、２３Ｂ、２３Ｃが開状態、電磁弁２３Ａ、１３Ｂ、１３Ｃが閉状態となるよう制御される。外調機の熱交換器６と室内空調機の熱交換器１８Ａは蒸発器、室内空調機の熱交換器１８Ｂ、１８Ｃは凝縮器として作用する。
【００５８】
この運転では、外調機３０のコンプレッサ１からの高圧ガス冷媒は、冷媒配管Ｒ３を経て分岐ユニット４０に入る。ここで冷媒は電磁弁２３Ｂ、２３Ｃを経て、室内空調機５０Ｂ、５０Ｃの熱交換器１８Ｂ、１８Ｃに入り、液化される。
熱交換器１８Ｂ、１８Ｃを出た冷媒は、分岐ユニット４０の分岐配管で合流し、一部は室内空調機５０Ａへ、残りは過冷却熱交換器１２、冷媒配管Ｒ１を経て外調機の液タンク２７に入り、続いて過冷却熱交換器４に入る。
【００５９】
外調機において、冷媒は過冷却熱交換器４で熱交換器６からのガス冷媒と熱交換され、過冷却が増大した液冷媒となる。そして、冷媒は膨張弁７で減圧され低温の気液混合状態になり、熱交換器６に入る。熱交換器６で室外空気と熱交換され、ガス状となった冷媒は、電磁弁５Ａを経て過冷却熱交換器４を通過し、前述のように液タンク２７からきた液冷媒を冷却するとともに、自らは過熱度が増したガス冷媒となる。
【００６０】
一方、室内空調機５０Ａへ入った冷媒は、膨張弁１５Ａで減圧されて低温の気液混合状態となる。つぎに、熱交換器１８Ａで還気と熱交換され、ガス状の冷媒となる。その後、電磁弁１３Ａを経て冷媒配管Ｒ２を通り外調機３０に向かう。
冷媒は外調機３０内で過冷却熱交換器４を出た冷媒と合流し、アキュムレータ３を経てコンプレッサ１に戻る。
【００６１】
この間における外調機３０の膨張弁７、流量調整弁２５、送風機２１、室内空調機５０Ａの流量調整弁１４Ａ、膨張弁１５Ａ、室内空調機５０Ｂ、５０Ｃの流量調整弁１４Ｂ、１４Ｃ、膨張弁１５Ｂ、１５Ｃの制御は以下のように行われる。
まず、外調機制御部３１は、全暖房運転時の制御と同様に、過熱度が一定になるよう膨張弁７を制御する。流量調整弁２５も同様に、図１０に示される過冷却度レベルと外調機負荷の関係より求められる値になるように制御する。
また、送風機２１については、全暖房運転時の制御と同様に、圧力センサ１１Ｂにより検出される圧力が予め設定された値になるように送風機用インバータ３３を駆動させて、風量制御が行なわれる。
【００６２】
室内空調機５０Ａの室内空調機制御部５１Ａによる制御は、冷暖同時冷房主運転の室内空調機５０Ｂ、５０Ｃの制御と同様であるので省略する。また、室内空調機５０Ｂ、５０Ｃの室内空調機制御部５１Ｂ、５１Ｃの制御も冷暖同時冷房主運転時の室内空調機５０Ａと同様である。
【００６３】
次に例えば室内空調機５０Ａが暖房運転、室内空調機５０Ｂ、５０Ｃが冷房運転で、冷房負荷と暖房負荷が同じときには、両負荷間の差分に対して外調機３０の熱交換器６を凝縮器あるいは蒸発器として働かせる必要がないから、流量調整弁２５が閉じられ、同じく送風機２１も停止される。そして、室内空調機５０Ａを流れた冷媒は全て、互いに並列の室内空調機５０Ｂおよび５０Ｃに流れて熱量がバランスする。
【００６４】
上述した外調機制御部および室内空調機制御部における制御の流れが図１５、図１６に簡潔に示される。
すなわち、外調機制御部では、図１５に示すように、まずステップ１０１において、室内空調機制御部５１Ａ〜５１Ｃからの室内空調機の負荷量など運転状況の情報を入力し、ステップ１０２でこれらの運転モード別に積算する。そしてステップ１０３において、モード別積算負荷量を比較し、冷房負荷が大きいときはステップ１０４に、暖房負荷が大きいときはステップ１１３に、そして両負荷が同じときにはステップ１２４に進む。
【００６５】
冷房負荷が大きいときは、まずステップ１０４で、その冷房負荷の負荷量に相当する制御信号がインバータ３２に送出されてコンプレッサ１が駆動されるとともに、ステップ１０５で、熱交換器６が凝縮器として働くモードとされる。
次のステップ１０６では、熱交換器負荷量が冷房負荷と暖房負荷の差として求められ、ステップ１０７において目標の過冷却度が演算あるいはグラフ読み取りで求められる。
【００６６】
ステップ１０８で、圧力センサ８の検出値に基づく冷媒の飽和温度と温度センサ９の検出温度との差により実際の過冷却度が求められる。そして、ステップ１０９において、制御過冷却度と実際の過冷却度を一致させるように流量調整弁２５が制御される。
このあとステップ１１０では、圧力センサ１１Ａによりコンプレッサ１の吐出圧力が検出され、ステップ１１１において、吐出圧力が予め設定された値になるようインバータ３３を駆動させて、送風機２１の風量制御が行なわれる。このあと、ステップ１０１に戻る。
【００６７】
次に、暖房負荷が大きいときは、ステップ１１３において、その暖房負荷の負荷量に相当する制御信号がインバータ３２に送出されてコンプレッサ１が駆動されるとともに、ステップ１１４で、熱交換器６が蒸発器として働くモードとされる。
次のステップ１１５では、熱交換器負荷量が暖房負荷と冷房負荷の差として求められ、ステップ１１６において目標の過冷却度が演算あるいはグラフ読み取りで求められる。
【００６８】
ステップ１１７で、圧力センサ８の検出値に基づく冷媒の飽和温度と温度センサ９の検出温度との差により実際の過冷却度が求められる。そして、ステップ１１８において、制御過冷却度と実際の過冷却度を一致させるように流量調整弁２５が制御される。
続いてステップ１１９では、温度センサ１０Ａ、１０Ｂの検出温度から熱交換器６の過熱度が求められ、ステップ１２０でこれを一定に保持するよう膨張弁７が制御される。
このあとステップ１２１では、圧力センサ１１Ｂによりコンプレッサ１の吸い込み圧力が検出され、ステップ１２２において、この圧力が予め設定された値になるよう送風機２１の風量制御が行なわれる。このあと、ステップ１０１に戻る。
【００６９】
冷房負荷と暖房負荷が同じときには、ステップ１２４において、流量調整弁２５が閉じられ、ステップ１２５で送風機２１が停止される。
【００７０】
一方、個々の室内空調機制御部では図１６、図１７に示すように、ステップ２０１においてまず送風機２４が起動される。次いでステップ２０２で、温度センサ４５より空調ゾーンの室内温度が検出され温度保持部５２に保持される。そして、ステップ２０３で、室温設定器４９より設定室内温度が入力される。次にステップ２０４で起動時の給気温度が演算される。さらに、ステップ２０５で温度センサ２６により室内空調機の還気温度を検出し、ステップ２０６で演算で設定された給気温度と還気温度を比較して、冷房運転するか暖房運転するかの運転モードを決定する。
【００７１】
冷房運転モードの場合には、ステップ２０７において、まず冷房モードに電磁弁を切り換え、ステップ２０８で、温度センサ２２により実給気温度を検出し、ステップ２０９で検出した給気温度（検出温度）と設定された給気温度（設定温度）を比較し、検出温度が低くければステップ２１０へ、高かければステップ２１１へ、同じならステップ２１２へ進む。
そして、ステップ２１０では現在の過冷却度を小さくするよう設定され、ステップ２１１では過冷却度を大きくするよう設定され、ステップ２１２で現在の過冷却度を検出し、ステップ２１３で設定された過冷却度になるよう流量調整弁１４が制御される。さらに、ステップ２１４で現在の室内空調機の運転状態の情報を外調機へ送出する。
【００７２】
つぎに、ステップ２１５で温度センサ１９、２０により過熱度を検出し、それに基づきステップ２１６で膨張弁１５を制御する。
つぎに、ステップ２１７で給気温度の変更時間がきているかどうかがチェックされる。 給気温度変更時間が経過していない間はステップ２０７へもどり、設定された給気温度変更時間がすでに経過していればステップ２１８へ進む。
ステップ２１８では、温度センサ４５により室内温度を検出し、ステップ２１９で前回の検出温度と比較して室内温度の変化方向を求める。そして、ステップ２２０で給気温度の変更量を演算して、給気温度を更新したあと、ステップ２０５へもどる。
【００７３】
一方、暖房モードの場合はステップ２２１において暖房モードに電磁弁を切り換え、ステップ２２２で実給気温度を検出し、ステップ２２３で、検出された給気温度と設定された給気温度を比較し、検出した温度が低ければステップ２２４へ、高ければステップ２２５へ、同じならばステップ２２６へ進む。
そしてステップ２２４では現在の過冷却度を小さくするよう設定され、ステップ２２５では過冷却度を大きくするよう設定されたあと、ステップ２２６へ進む。
ステップ２２６では現在の過冷却度を検出し、ステップ２２７で流量調整弁を制御される。
つぎに、ステップ２２８で室内空調機の運転状態の情報を外調機へ送出する。
【００７４】
このあと、ステップ２２９で給気温度変更時間が経過しているかどうかがチェックされる。
給気温度変更時間がまだ経過していない場合にはステップ２２１へ戻り、経過していればステップ２３０へ進む。
さらに、ステップ２３０で室内温度を検出し、ステップ２３１で前回の検出温度と比較して室内温度の変化方向を求める。そして、ステップ２３２で給気温度の変更量を演算して、給気温度を更新したあと、ステップ２０５へもどる。
【００７５】
以上説明した本実施例を簡単にまとめると次のようになる。まず、外調機から分岐ユニットを介して複数の室内空調機に並列に配管されたヒートポンプ式空気調和装置において、室内空調機の送風をダクトにより複数の空調ゾーンに導き各空調ゾーンごとに給気温度を変更可能とし、分岐ユニットに過冷却熱交換器と、その切り換えにより冷房運転と暖房運転を選択可能の電磁弁を備え、外調機に過冷却熱交換器を備えてその液管側には流量調整弁と膨張弁を設けた。室内空調機の熱交換器の液管側には流量調整弁と膨張弁を設け、各室内空調機の負荷に応じて変更される給気温度になるよう流量調整弁で過冷却度を制御し、冷房運転時は膨張弁を熱交換器の過熱度が一定になるように制御するものとした。一方、外調機においては、その流量調整弁を外調機の負荷に応じた過冷却度になるよう制御し、その熱交換器が凝縮モードのときは膨張弁を全開にし、蒸発モードのときは熱交換器の過熱度が一定になるよう制御するものとした。そして、室内空調機の給気温度は起動時に設定室内温度と検出室内温度から決定されたもので開始し、所定時間経過後は設定室内温度と検出室内温度とその変化量に基づいて給気温度を順次変更するものとした。
これにより、各空調ゾーンの個別の要求にあわせて、冷房運転および暖房運転が任意に実行でき、しかも給気温度を自由に変更できるという効果を有する。また、他の室内空調機の負荷状態の影響を受けることなく、給気温度の変化により各空調ゾーンの室内温度を任意に制御できるため快適な環境を得られるという効果を有する。
【００７６】
したがって、多数の個別の空調ゾーン内に空調機を設置する必要がなく、簡単なダクト接続だけで済むから、メンテナンス性が向上する。
また、冷房運転時には、とくに過冷却熱交換器１２により室内空調機の流量調整弁に入る冷媒の過冷却度が増大されるので、流量調整弁の調整幅が拡大でき、安定した冷凍サイクルが得られる。
さらに、冷房運転時に室内空調機の給気風量が急減したとき、過冷却熱交換器１２が一時的な蓄熱器として作用し、液冷媒が外調機のコンプレッサ１に入る液圧縮現象が防止され、暖房運転時に給気風量が急減したときにも、外調機の過冷却熱交換器４が一時的な蓄熱器として作用し、冷媒の確実な液化を促進して膨張弁７での制御性の低下が防止される。
【００７７】
また、各室内空調機５０Ａ、５０Ｂ、５０Ｃの設置場所がまちまちで、外調機３０からの配管長に差があっても、各室内空調機の膨張弁と流量調整弁間の冷媒の状態を同じにできるので、設置工事に際して配管圧損を考慮に入れなくても同じ空調能力が得られる。
【００７８】
なお、実施例では各室内空調機で熱交換された空気がダクトにより各空調ゾーンへ導かれているが、これに限定されず、例えばビル内の天井や床下をサプライチャンバーとして利用して給気を導くダクトレス方式の場合にも同様に適用することができる。
また、この実施例では、設定室内温度と検出室内温度の差より起動時給気温度を決定するのに図４で示される関係表を用いるものとしたが、このほか例えば、検出室内温度と設定室内温度の差が０を挟む所定範囲内のときは室温（検出室内温度）のままとし、差が所定範囲を越えたら室温に対して加減した値とする、図１８に示すような関係表など適宜のものを設定できる。
【００７９】
図１９は、本発明の第２の実施例を示す。この実施例は、上述の第１の実施例の冷媒回路に対して、分岐ユニットを廃止し、分岐ユニットにあった過冷却熱交換器を各室内空調機毎に設けるようにしたものである。
すなわち、外調機３０から延びる冷媒配管Ｒ１’、Ｒ２’、Ｒ３’が分岐されて、各室内空調機５０Ａ’、５０Ｂ’、５０Ｃ’へ並列に接続されている。そして、各室内空調機内において、冷媒配管Ｒ１’が過冷却熱交換器１２Ａ、１２Ｂ、１２Ｃを通ったあと、流量調整弁１４Ａ、１４Ｂ、１４Ｃに接続される。
また、冷媒配管Ｒ２’は過冷却熱交換器１２Ａ、１２Ｂ、１２Ｃの他の通路に入り、電磁弁１３Ａ’、１３Ｂ’、１３Ｃ’を介して熱交換器１８Ａ、１８Ｂ、１８Ｃのガス管側に接続されている。さらに、冷媒配管Ｒ３’は電磁弁２３Ａ’、２３Ｂ’、２３Ｃ’を介して熱交換器１８Ａ、１８Ｂ、１８Ｃのガス管に接続されている。
【００８０】
そして、電磁弁１３Ａ’と２３Ａ’、１３Ｂ’と２３Ｂ’、１３Ｃ’と２３Ｃ’は、第１の実施例と同様にそれぞれ一方が開状態のとき、他方が閉状態となるよう制御される。
その他の構成は第１の実施例と同じである。各運転モードにおける冷媒の流れも第１の実施例と同じであるから、作動についての説明は省略する。
【００８１】
この実施例によれば、第１の実施例と同じ効果を有するとともに、過冷却熱交換器を各室内空調機毎に分割して設けるから、膨張弁に向かう全ての冷媒がいずれかの過冷却熱交換器を通過し、過冷却度を増すことができ、過冷却熱交換器も取り扱いが簡単で小型、安価なものが使用できる利点がある。
【００８２】
なお、上記実施例では、室内空調機が３台接続されたものを示したが、室内空調機の台数はこれに限定されることなく、２台でもあるいは４台以上でも同様に実施可能であり、給気しない室内空調機があれば流量調整弁を全閉にして作動させないことも可能である。
また、分岐ユニットを複数設けて、それぞれの分岐ユニットに複数の室内空調機を接続することもでき、さらには第１の実施例と第２の実施例を組み合わせてもよい。
【００８３】
【発明の効果】
以上のとおり本発明は、外調機に複数の室内空調機が並列に接続された空気調和装置において、各室内空調機と外調機の熱交換器のガス管を高圧ガス管または低圧ガス管と選択的に接続することにより、各室内空調機ごとに冷房運転と暖房運転を選択できるようにし、各室内空調機の給気をダクトにより複数の空調ゾーンに導き、各空調ゾーンごとに給気温度変化でそれぞれ空調ゾーンの室内温度調節が行われ、全ての空調ゾーンの要求に応じられ、かつ快適な環境が得られるという効果を有する。
そして、個別に多数の空調機を設置を設置する必要がないからメンテナンス性が向上するとともに、冷暖同時運転時には、室内空調機間で熱エネルギーの移動が行われるので大幅な省エネルギー効果が得られる。
【００８４】
さらに、冷媒の過冷却度が当該室内空調機の給気温度に応じて決定される値になるようにその流量調整手段を制御することにより任意の給気温度で給気できる空気調和が行われる。また、これにより、室内空調機の膨張弁が他の室内空調機の影響を受けないので、各室内空調機の設置場所による能力差がなくなり、空調設計時に能力補正する必要がなく、また、設置工事が簡略化できるという効果がある。
【００８５】
なお、複数の室内空調機に向かう液管と低圧ガス管の間に第１の過冷却熱交換器を設けることにより、流量調整手段による流量の制御幅が拡大される。これにより、例えば室内空調機の給気風量を急減させても、過冷却熱交換器の蓄熱器作用で戻りの冷媒が確実にガス化され、コンプレッサの破損が防止される。
また、外調機の熱交換器に向かう液管と低圧ガス管の間に第２の過冷却熱交換器を設けることにより、外調機のコンプレッサに入るガス冷媒の過熱度を大きくすることができ、暖房能力が向上するとともに、室内空調機の給気温度を急変させた場合にも、過冷却熱交換器の蓄熱器作用で戻り冷媒の確実な液化を促進させることができる。
【００８６】
さらに、室内空調機の給気温度を起動時に空調ゾーンの検出した室内温度と設定温度により決定される給気温度で給気を始め、また、給気温度を室内温度と室内温度の変化と設定温度により決定される温度で給気することにより室内温度を速やかに設定温度にすることができ、またハンチングを起こすこともなく快適な空気調和を得られる効果がある。
【図面の簡単な説明】
【図１】 本発明の第１の実施例のシステム構成を示す図である。
【図２】 実施例における冷媒回路図である。
【図３】 室内空調機および外調機における制御装置を示す図である。
【図４】 起動時の検出室内温度と設定室内温度と給気温度の関係を示すグラフである。
【図５】 運転中の検出室内温度と設定室内温度と給気温度の変化量関係を示すグラフである。
【図６】 全冷房運転時の冷媒の流れを示す図である。
【図７】 全冷房運転時の外調機の負荷と過冷却度の関係を示すグラフである。
【図８】 全冷房運転時の制御要領を示す冷凍サイクルのモリエル線図である。
【図９】 全暖房運転時の冷媒の冷媒の流れを示す図である。
【図１０】 全暖房運転時の外調機の負荷と過冷却度の関係を示すグラフである。
【図１１】 全暖房運転時の制御要領を示す冷凍サイクルのモリエル線図である。
【図１２】 冷暖同時冷房主運転時の冷媒の流れを示す図である。
【図１３】 冷暖同時冷房主運転時の制御要領を示す冷凍サイクルのモリエル線図である。
【図１４】 冷暖同時暖房主運転の冷媒の流れを示す図である。
【図１５】 外調機制御部における制御の流れを示すフローチャートである。
【図１６】 室内空調機制御部における制御の流れを示すフローチャートである。
【図１７】 室内空調機制御部における制御の流れを示すフローチャートである。
【図１８】 起動時の検出室内温度と設定室内温度と給気温度の関係の変形例を示すグラフである。
【図１９】 第２の実施例を示すシステム構成図である。
【符号の説明】
１ コンプレッサ
３ アキュムレータ
４ 過冷却熱交換器（第２の過冷却熱交換器）
５Ａ、５Ｂ 電磁弁
６ 熱交換器
７ 膨張弁
８ 圧力センサ
９ 温度センサ
１０Ａ、１０Ｂ 温度センサ
１１Ａ、１１Ｂ 圧力センサ
１２ 過冷却熱交換器（第１の過冷却熱交換器）
１３Ａ、１３Ｂ、１３Ｃ、２３Ａ、２３Ｂ、２３Ｃ 電磁弁
１３Ａ’、１３Ｂ’、１３Ｃ’、２３Ａ’、２３Ｂ’、２３Ｃ’ 電磁弁
１４Ａ、１４Ｂ、１４Ｃ 流量調整弁
１５Ａ、１５Ｂ、１５Ｃ 膨張弁
１６Ａ、１６Ｂ、１６Ｃ 圧力センサ
１７Ａ、１７Ｂ、１７Ｃ 温度センサ
１８Ａ、１８Ｂ、１８Ｃ 熱交換器
１９Ａ、１９Ｂ、１９Ｃ、２０Ａ、２０Ｂ、２０Ｃ 温度センサ
２１ 送風機
２２Ａ、２２Ｂ、２２Ｃ、２６Ａ、２６Ｂ、２６Ｃ 温度センサ
２４Ａ、２４Ｂ、２４Ｃ 送風機
２５ 流量調整弁
２７ 液タンク
３０ 外調機
３１ 外調機制御部
３４、３５、４８ 駆動制御部
３６ 温度変換器
３７ 圧力変換器
３９Ａ、３９Ｂ、３９Ｃ、４１Ａ、４１Ｂ、４１Ｃ 駆動制御部
４０ 分岐ユニット
４２Ａ、４２Ｂ、４２Ｃ、４４Ａ、４４Ｂ、４４Ｃ 温度変換器
４３Ａ、４３Ｂ、４３Ｃ 圧力変換器
４５Ａ、４５Ｂ、４５Ｃ 温度センサ
４６Ａ、４６Ｂ、４６Ｃ 給気温度設定部
４７Ａ、４７Ｂ、４７Ｃ ダクト
４８Ａ、４８Ｂ、４８Ｃ 駆動制御部
４９Ａ、４９Ｂ、４９Ｃ 室温設定器
５０Ａ、５０Ｂ、５０Ｃ、５０Ａ’、５０Ｂ’、５０Ｃ’ 室内空調機
５１Ａ、５１Ｂ、５１Ｃ 室内空調機制御部
５２Ａ、５２Ｂ、５２Ｃ 温度保持部
Ｒ１、Ｒ２、Ｒ３、Ｒ１’、Ｒ２’、Ｒ３’ 冷媒配管
ＺＡ、ＺＢ、ＺＣ 空調ゾーン[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multi-type air conditioner that includes an external air conditioner and a plurality of indoor air conditioners and is used for air conditioning of a building or the like.
[0002]
[Prior art]
For air conditioning of buildings and the like, air conditioning devices such as air handling units and fan coils are generally used with cold / hot water as a heat source. In particular, the constant air flow single duct type air handling unit is an air conditioner that controls the indoor temperature of the air conditioning zone by sending a constant amount of air to the air conditioning zone and changing the supply air temperature. Yes. However, in recent years, water quality has deteriorated drastically, which has caused many problems such as corrosion of pipes, and there has been a desire to refrain from using water as much as possible. As an answer to such a demand, for example, a heat pump multi-system using a refrigerant as a direct heat source has been proposed.
On the other hand, air conditioning in recent years has diversified, and it is no longer as simple as cooling operation in summer and heating operation in winter. That is, in a building or the like, there are cases where it is desired to simultaneously perform the cooling operation and the heating operation in the air conditioning system depending on the season, the direction and position of the room, and the load of the OA equipment. For example, there is a case where it is desired to perform a cooling operation in an interior zone in a building and a heating operation in a perimeter zone.
[0003]
In the middle of spring and autumn, there are cases where heating operation is required in the morning and evening, and cooling operation is required in the daytime. In this case, the timing for switching between the cooling operation and the heating operation differs depending on the direction of the air conditioning zone, and although the condition for switching to the cooling operation on the south side has been reached, the heating operation may still need to be maintained on the north side. .
Furthermore, in places with a heavy load such as OA equipment, it may be necessary to perform cooling operation all day even in winter.
Therefore, as a countermeasure against this, a special air conditioning system that has a cooling heat exchanger and a heating heat exchanger called a four-pipe air handling unit and can supply air at any temperature from cooling to heating may be adopted.
[0004]
[Problems to be solved by the invention]
However, the four-pipe type air handling unit method has to have two heat sources, a cold heat source and a heat source, and has a drawback that both the equipment cost and the operation cost are high. Furthermore, since the waste heat of the two heat sources is discarded, it goes against energy saving.
In addition, the heat pump multi system capable of simultaneous cooling and heating installs the indoor unit in a living area, and its maintainability is extremely low. In addition, since this is an indoor circulation type air conditioning system, a new outdoor air processing device must be installed for each indoor unit for the outdoor air processing function, and there is a problem that high equipment costs are required.
[0005]
In addition, during simultaneous cooling and heating, multiple indoor units in the same mode, or between the indoor unit and outdoor unit in the same mode cannot properly distribute refrigerant, and the compressor capacity control is not sufficient, so the blowing temperature However, since the temperature varies depending on the indoor unit, it is difficult to say that the room temperature controllability is good at present when the set temperature is reached and the refrigerant control valve of the indoor unit is closed to stop the function.
[0006]
In addition, individual outdoor units and indoor units must be installed for multiple air conditioning zones with different loads due to the orientation and position of the air conditioning zone in the building and the uneven distribution of OA equipment. The number increases, which increases the installation space.
Furthermore, in the simultaneous cooling and heating type heat pump multi-system, the blast temperature cannot be controlled simply by controlling the compressor capacity. This is because, in the cooling and heating simultaneous operation type heat pump multi-system, the refrigerant piping distance varies from the outdoor unit to a plurality of indoor units, and the pressure loss is proportional to the square of the refrigerant flow velocity. This is because the refrigerant pressure distribution reaching each indoor unit changes greatly, and the refrigerant flow rate of each indoor unit also changes.
[0007]
The constant air volume single duct type air handling unit detects the indoor temperature of the air-conditioning zone and controls the supply air temperature based on the difference from the set temperature. For example, during the cooling operation, step control is performed in which the supply air temperature is lowered by a certain amount when the room temperature is higher than the set temperature, and the supply air temperature is raised by a certain amount when the room temperature is low. However, if the difference is large, it takes a long time for the room temperature to reach the set temperature, or if the amount of change in the supply air temperature is too large, a cold draft will occur or the room temperature will cause hunting.
Furthermore, since the supply air temperature at startup is a preset temperature and does not take into account the load of the air conditioning zone, it takes time to reach the set temperature when the load is large. There was a problem that it was not possible to respond to requests for an early start-up such as noon.
[0008]
Therefore, in view of the above-described conventional problems, the present invention provides an air conditioner equipped with an external air conditioner and a plurality of indoor air conditioners according to the required load in each air conditioning zone without requiring high equipment costs. It is an object of the present invention to provide an air conditioner that can be individually operated for cooling or heating, and further an air conditioner that can individually change the supply air temperature to an arbitrary temperature and is excellent in energy saving.
[0009]
[Means for Solving the Problems]
  For this reason, the present invention provides a heat exchanger, an expansion valve attached to the heat exchanger, a flow rate adjusting means provided in front of the expansion valve, andFrom refrigerant temperature and pressure valuesAn external air conditioner comprising first control means for controlling the flow rate adjusting means, a heat exchanger, an expansion valve attached to the heat exchanger, a flow rate adjusting means provided in front of the expansion valve, andFrom refrigerant temperature and pressure valuesA second control means for controlling the flow rate adjusting means, comprising a plurality of indoor air conditioners connected in parallel to the external air conditioner by a refrigerant pipe forming a liquid pipe, a high pressure gas pipe and a low pressure gas pipe of the refrigeration cycle; In addition to guiding the air supply of each indoor air conditioner for each air conditioning zone, the gas pipe connected to the heat exchanger of the external air conditioner is selected as the high pressure gas pipe or low pressure gas pipe that goes to the heat exchanger of the external air conditioner First switching means connectable to each other, and second switching means capable of selectively connecting the gas pipe connected to the heat exchanger of each indoor air conditioner to the high pressure gas pipe or the low pressure gas pipe Thus, each indoor air conditioner is selectively controlled to the cooling operation or the heating operation individually, and the indoor temperature of each air conditioning zone is controlled by changing the supply air temperature.
[0010]
The second control means of the indoor air conditioner controls the flow rate adjusting means of the indoor air conditioner so as to change the degree of supercooling of the refrigerant entering the expansion valve of the indoor air conditioner according to the supply air temperature during the cooling operation. And controlling the flow rate adjusting means of the indoor air conditioner so as to change the degree of supercooling of the refrigerant that has exited the heat exchanger of the indoor air conditioner according to the supply air temperature during heating operation. desirable.
Further, the first control means of the external air conditioner is configured such that when the heat exchanger of the external air conditioner acts as a condenser, the degree of supercooling of the refrigerant that exits the heat exchanger of the external air conditioner depends on the load of the heat exchanger. The flow rate adjusting means of the external air conditioner is controlled so as to be a value determined according to the external air conditioner, and when the heat exchanger of the external air conditioner acts as an evaporator, the excess of the refrigerant entering the expansion valve of the external air conditioner is controlled. It is desirable to control the flow rate adjusting means of the external air conditioner so that the degree of cooling becomes a value determined according to the load of the heat exchanger of the external air conditioner.
[0011]
  Further, when the heat exchanger acts as an evaporator in at least one of the indoor air conditioners, heat exchange is performed between the liquid pipe toward the indoor air conditioner and the low pressure gas pipe toward the external conditioner. It is preferable to provide a first supercooling heat exchanger, and when the heat exchanger of the external air conditioner acts as an evaporator, between the liquid pipe and the low pressure gas pipe that are directed to the heat exchanger of the external air conditioner, It is preferable to provide a second subcooling heat exchanger that exchanges heat with each other.
  The supply air temperature is set to a value determined from the room temperature and the set temperature of each air-conditioning zone when the indoor air conditioner is started, and then the set temperature and the room temperature are set.Value determined byAnd changes in room temperatureDepending on the correction value byIt is desirable to change based on the value determined.
[0012]
[Action]
Air is supplied from each indoor air conditioner to each air conditioning zone via a duct, and the indoor temperature is adjusted for each air conditioning zone by changing the supply air temperature of each indoor air conditioner. In the external air conditioner and the indoor air conditioner, the first and second control means control the degree of supercooling so that the temperature to be supplied is reached by using the flow rate adjusting valves arranged in front of the respective expansion valves, By selectively connecting the gas pipes of the heat exchangers of each indoor air conditioner and external air conditioner to the high-pressure gas pipe or low-pressure gas pipe, any indoor air conditioner can be used in the form of simultaneous cooling and heating operations. Either can be selected.
In addition, during simultaneous cooling and heating operation, heat energy is transferred between indoor air conditioners, resulting in significant energy savings.
[0013]
Further, the second control means of the indoor air conditioner changes the supply air temperature by controlling the degree of supercooling of the refrigerant by the flow rate adjustment means so that the supply air temperature is determined according to the room temperature. However, in each indoor air conditioner without causing interference with other indoor air conditioners, the pressure of the refrigerant entering the expansion valve can be stably maintained, and air conditioning with stable supply air temperature is performed.
[0014]
In addition, when the 1st subcooling heat exchanger is provided between the liquid pipe which goes to several indoor air conditioners, and a low pressure gas pipe, the control range of the flow volume by a flow volume adjustment means is expanded. Further, when the second supercooling heat exchanger is provided between the liquid pipe and the low-pressure gas pipe heading to the heat exchanger of the external air conditioner, the degree of superheat of the gas refrigerant entering the compressor of the external air conditioner should be increased. Can improve the heating capacity.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the system configuration of the first embodiment of the present invention. In this embodiment, three indoor air conditioners 50 </ b> A, 50 </ b> B, and 50 </ b> C are connected in parallel to one external air conditioner 30 via a branch unit 40. From each indoor air conditioner, heat-exchanged air is guided to the air-conditioning zones ZA, ZB, and ZC through ducts 47A, 47B, and 47C. Each duct is appropriately branched according to the number of the corresponding air-conditioning zones and individually sent to the air-conditioning zones. 45A, 45B, and 45C are indoor temperature sensors, and 49A, 49B, and 49C are indoor temperature setting devices connected to the indoor air conditioners 50A, 50B, and 50C, respectively.
In addition, as described in detail below, the “outdoor air conditioner” is used as an alias for a so-called outdoor unit that performs refrigerant processing in preparation for use in an indoor air conditioner (hereinafter the same in the present application).
[0016]
FIG. 2 shows the refrigerant circuit of this embodiment. The three indoor air conditioners 50A, 50B, 50C are connected in parallel to the external air conditioner 30 by the refrigerant pipes R1, R2, R3 forming the liquid pipe, the low pressure gas pipe and the high pressure gas pipe via the branch unit 40. It is connected.
The external air conditioner 30 includes a variable capacity compressor 1 and a heat exchanger 6. Pressure sensors 11A and 11B are provided on the discharge side and suction side pipes of the compressor 1, respectively.
The heat exchanger 6 is provided with a blower 21 and temperature sensors 10A and 10B are provided at both ends, respectively.
[0017]
The external air conditioner 30 is further provided with a supercooling heat exchanger 4, an electronic flow rate adjusting valve 25 in order from the supercooling heat exchanger 4 side toward the heat exchanger 6, and a temperature sensor 9 for detecting the refrigerant temperature. A pressure sensor 8 and an electronic expansion valve 7 are installed.
The other end of the supercooling heat exchanger 4 is connected to the refrigerant pipe R <b> 1 via the liquid tank 27. The refrigerant pipe (gas pipe) on the other end side of the heat exchanger 6 is connected to the inlet of the heat exchange passage of the supercooling heat exchanger 4 via the electromagnetic valve 5A, and the refrigerant pipe R3 via the electromagnetic valve 5B. It is connected to the. The outlet of the heat exchange passage of the supercooling heat exchanger 4 is connected to the refrigerant pipe R2. The refrigerant pipe R2 is also connected to the accumulator 3, and the refrigerant pipe R3 is connected to the discharge side of the compressor 1.
[0018]
The branch unit 40 includes the supercooling heat exchanger 12. The supercooling heat exchanger 12 is connected to the liquid tank 27 of the external conditioner 30 by the refrigerant pipe R1. The outlet of the supercooling heat exchanger 12 is branched and connected to the indoor air conditioners 50A, 50B, and 50C.
Further, the branch unit 40 is provided with electromagnetic valves 13A, 13B, 13C, 23A, 23B, and 23C, and the electromagnetic valves 13A, 13B, and 13C respectively replace the indoor air conditioners 50A, 50B, and 50C with the supercooling heat exchanger 12. The other refrigerant pipe R2 system can be communicated, and the electromagnetic valves 23A, 23B, and 23C can communicate the indoor air conditioners 50A, 50B, and 50C to the refrigerant pipe R3.
[0019]
The indoor air conditioner 50A includes a heat exchanger 18A and a blower 24A attached thereto. One end of the heat exchanger 18A is connected to the R1 system of the supercooling heat exchanger 12 of the branch unit 40, and the other end is connected to the electromagnetic valves 13A and 23A of the branch unit 40.
The R1 pipe on one end side of the heat exchanger 18A includes an electronic flow adjustment valve 14A in order from the supercooling heat exchanger 12 side to the heat exchanger 18A, a temperature sensor 17A for detecting the refrigerant temperature, and a pressure sensor. 16A, an electronic expansion valve 15A is provided.
[0020]
The heat exchanger 18A is provided with temperature sensors 22A and 26A for detecting the supply air temperature and the return air temperature of the indoor air conditioner, and temperature sensors 19A and 20A for detecting the refrigerant temperature at both ends. Is provided.
The supply air heat-exchanged by the heat exchanger 18A and blown out by the blower 24A is guided to the air-conditioning zone ZA by the duct 47A as shown in FIG.
The indoor air conditioners 50B and 50C also have the same configuration as the indoor air conditioner 50A, and are hereinafter denoted by reference numerals B and C, respectively.
[0021]
FIG. 3 shows control devices in the indoor air conditioner and the external air conditioner. The control device includes a microcomputer and its peripheral devices for both the indoor air conditioner and the external air conditioner.
The external air conditioner control unit 31 is connected to an inverter 32 for the compressor 1 and an inverter 33 for the blower 21 of the external air conditioner.
Further, as peripheral devices, a drive control unit 34 for the expansion valve 7, a drive control unit 48 for the flow adjustment valve 25, a drive control unit 35 for the electromagnetic valves 5A and 5B, and a temperature converter for the temperature sensors 9, 10A and 10B. 36, a pressure transducer 37 for the pressure sensors 8, 11 </ b> A, 11 </ b> B is connected to the external controller control unit 31.
[0022]
On the other hand, the control device for the indoor air conditioner 50A includes an indoor air conditioner control unit 51A and a supply air temperature setting unit 46A connected thereto.
The indoor air conditioner control unit 51A includes, as peripheral devices, a temperature control unit 39A for the expansion valve 15A, a drive control unit 41A for the flow rate adjusting valve 14A, and temperature sensors 17A, 19A, 20A, 22A and 26A. 42A, a pressure converter 43A for the pressure sensor 16A, a drive controller 48A for the electromagnetic valves 13A and 23A, and a temperature converter 44A are connected. Connected to the temperature converter 44A are a temperature sensor 45A for detecting the indoor temperature of the air conditioning zone and a temperature holding unit 52A for holding the detected temperature. The supply air temperature setting unit 46A calculates and holds the supply air temperature based on the set room temperature input from the room temperature setter 49A.
The control devices in the indoor air conditioners 50B and 50C are configured in the same manner, and the indoor air conditioner control units 51B and 51C are indicated by adding B and C respectively to the reference numbers.
[0023]
The external air conditioner control unit 31 and each indoor air conditioner control unit 51A, 51B, 51C are connected by communication means, and the external air conditioner control unit 31 always knows the status of each indoor air conditioner control unit 51A, 51B, 51C. Can do.
The external air conditioner control unit 31 integrates the load amounts of the indoor air conditioners sent from the indoor air conditioner control units 51A, 51B, and 51C for each operation mode, and a control signal corresponding to the load amount of the larger operation mode. Is sent to the inverter 32 for the compressor 1. The inverter 32 drives the compressor 1 according to this control signal.
In addition, the external air conditioner control unit 31 is configured so that the heat exchanger 6 of the external air conditioner is in the same mode as the operation mode with the smaller load amount of the all indoor air conditioners, that is, the cooling operation load is greater. When it is small, the heat exchanger 6 of the external air conditioner 30 is controlled as an evaporator, and when the load for heating operation is smaller, the peripheral device is controlled so as to function as a condenser.
[0024]
The indoor air conditioner control units 51A, 51B, 51C detect the indoor temperature of the air conditioning zone from the temperature sensors 45A, 45B, 45C, and hold them in the respective temperature holding units 52A, 52B, 52C. At startup, the supply air temperature setting units 46A, 46B, and 46C are based on the difference between the set room temperature input from the room temperature setting devices 49A, 49B, and 49C and the detected room temperature obtained by the temperature sensors 45A, 45B, and 45C. The supply air temperature is determined from the relationship table shown in FIG. In FIG. 4, the supply air temperature that linearly changes around the detected room temperature (room temperature) according to the difference between the set room temperature and the detected room temperature is obtained.
[0025]
Next, the difference between the temperature data detected by the return air temperature sensors 26A, 26B, and 26C and the temperature data of the supply air temperature setting units 46A, 46B, and 46C is calculated, and each of the indoor air conditioners 50A, 50B, and 50C is in cooling operation. Or operating mode is determined. And since the supply air temperature of an indoor air conditioner is influenced by the return air temperature and humidity of an indoor air conditioner, the load increase / decrease amount which considered them is added, and the load amount equivalent to the output of the compressor 1 is operated. It is sent to the external air conditioner control unit 31 together with the mode.
[0026]
Control is performed based on the initially determined supply air temperature until the preset supply air temperature change time elapses from the start. The supply air temperature change time is determined in consideration of the scale of the entire system and other conditions, but is set in the range of about 5 to 30 minutes after normal startup.
The indoor air conditioner controllers 51A, 51B, 51C detect the indoor temperature every time the supply air temperature change time elapses, and calculate the difference between the detected indoor temperature and the set indoor temperature of the room temperature setting devices 49A, 49B, 49C. At the same time, it is compared with the temperatures of the room temperature holding units 52A, 52B, and 52C to determine whether the room temperature is rising, falling, or unchanged. Then, the change amount of the supply air temperature is determined according to the change state of the room temperature.
[0027]
FIG. 5 is a graph used for determining the change amount of the supply air temperature. The relationship between the change amount of the supply air temperature and the difference between the detected room temperature and the set room temperature is shown by a straight line. (A) is applied when the room temperature is increased, (b) is applied when the room temperature is not changed, (c) is applied when the room temperature is decreased, and (a) is applied to (b). In comparison, the straight line is shifted in a decreasing direction, and the supply air temperature is lowered by a predetermined amount even if the difference between the detected room temperature and the set room temperature is zero. Further, in (c), the straight line is shifted in an increasing direction as compared with (b), and the supply air temperature is increased by a predetermined amount even if the difference between the detected room temperature and the set room temperature is zero.
[0028]
The indoor air conditioner control units 51A, 51B, and 51C cause the supply air temperature setting units 46A, 46B, and 46C to hold the supply air temperature thus determined.
Further, the solenoid valves 5A and 5B, 13A and 23A, 13B and 23B, and 13C and 23C are controlled so that when one is open, the other is closed. However, when the indoor air conditioners do not need to be operated, both are closed.
[0029]
Next, the operation in the above configuration will be described.
FIG. 6 shows the flow of the refrigerant during the all-cooling operation in which all the indoor air conditioners are in the cooling operation.
When all the indoor air conditioners are in cooling operation, the electromagnetic valve 5B is opened and the electromagnetic valve 5A is closed in the external air conditioner, and the electromagnetic valves 13A, 13B, and 13C are opened in the branch unit, respectively, Control is performed so that 23B and 23C are closed. The heat exchanger 6 of the external air conditioner functions as a condenser, and the heat exchangers 18A, 18B, and 18C of each indoor air conditioner function as an evaporator.
[0030]
That is, in the external air handler 30, the high-pressure gas refrigerant from the compressor 1 passes through the electromagnetic valve 5 </ b> B as indicated by an arrow and is liquefied by the heat exchanger 6. Then, the refrigerant enters the supercooling heat exchanger 12 of the branch unit 40 through the refrigerant pipe R1 through the supercooling heat exchanger 4 and the liquid tank 27. The refrigerant is heat-exchanged by the supercooling heat exchanger 12 with the gas refrigerant emitted from the heat exchangers 18A, 18B, and 18C of the indoor air conditioners 50A, 50B, and 50C, and becomes a liquid refrigerant having an increased degree of supercooling.
[0031]
Further, the refrigerant is branched by the branch pipe, enters in parallel with the flow rate adjusting valves 14A, 14B, and 14C, and then is decompressed by the expansion valves 15A, 15B, and 15C to be in a low-temperature gas-liquid mixed state.
Next, the refrigerant is heat-exchanged with the return air in the heat exchangers 18A, 18B, and 18C to become a gaseous refrigerant. And it returns to the supercooling heat exchanger 12 through electromagnetic valve 13A, 13B, 13C, and cools the liquid refrigerant which enters from refrigerant | coolant piping R1 from the external air conditioner 30. FIG. The refrigerant that has exited the supercooling heat exchanger 12 returns to the compressor 1 of the external air handler 30 via the refrigerant pipe R2.
The flow rate adjusting valves 14A, 14B, 14C constitute the flow rate adjusting means of the indoor air conditioner of the invention, and the supercooling heat exchanger 12 constitutes the first supercooling heat exchanger of the invention.
[0032]
During this time, the expansion valve 7, the flow rate adjustment valve 25, the blower 21, the flow rate adjustment valves 14A, 14B, and 14C of the indoor air conditioners 50A, 50B, and 50C, and the expansion valves 15A, 15B, and 15C are controlled as follows. To be done.
First, the expansion valve 7 is held in the fully open state by the external air conditioner control unit 31. Next, the external air conditioner control unit 31 detects the refrigerant pressure with the pressure sensor 8 and calculates the saturation temperature of the refrigerant entering the flow rate adjustment valve 25. Then, the flow rate adjusting valve 25 is controlled so that the difference from the temperature detected by the temperature sensor 9, that is, the degree of supercooling, becomes a value obtained from the calculation of the relational expression between the predetermined load of the external air conditioner and the degree of supercooling. . The relational expression between the load of the external air conditioner and the supercooling degree level is not only calculated, but also stored in a graph format indicating levels C1 to C10 as shown in FIG. 7, for example, and can be read from now on.
[0033]
Further, for example, a signal by PID control or step control is output to the blower inverter 33 so that the pressure detected by the discharge-side pressure sensor 11A of the compressor 1 becomes a preset value, and the blower 21 is driven. To control the air volume.
[0034]
On the other hand, in the indoor air conditioner control units 51A, 51B, and 51C, the supply air temperatures detected by the temperature sensors 22A, 22B, and 22C are the temperatures previously determined and held in the supply air temperature setting units 46A, 46B, and 46C. Calculate the necessary degree of supercooling.
Next, the pressure of the refrigerant is detected by the pressure sensors 16A, 16B, 16C, the saturation temperature of the refrigerant entering each expansion valve 15A, 15B, 15C is calculated, and the difference from the temperature detected by the temperature sensors 17A, 17B, 17C. To calculate the actual degree of supercooling.
Then, the flow rate adjusting valves 14A, 14B, and 14C are controlled so as to obtain a necessary degree of supercooling.
That is, when the detected supply air temperature is higher than the temperature held in the supply air temperature setting unit 46A, 46B, 46C, the flow rate adjustment valves 14A, 14B, 14C are controlled to increase the degree of supercooling of the refrigerant, and the detected temperature When the temperature is lower than the maintained temperature, the flow rate adjusting valves 14A, 14B, and 14C are controlled to reduce the degree of supercooling.
[0035]
Further, the temperature sensor 19A, 19B, 19C, 20A, 20B, 20C is expanded so that the temperature difference between the refrigerant at the inlet and outlet of the heat exchangers 18A, 18B, 18C, that is, the degree of superheat, is constant. The valves 15A, 15B, and 15C are controlled.
Here, if the load of each indoor air conditioner 50A, 50B, 50C is equivalent, the opening degree of each flow regulating valve 14A, 14B, 14C will become the same. In this case, the refrigerant is equally distributed from the branch unit 40 to the indoor air conditioners 50A, 50B, and 50C, and the supply air temperatures are the same.
[0036]
Here, for example, it is assumed that the load on the indoor air conditioner 50A is heavy and the supply air temperature is set low, and the load on the indoor air conditioners 50B and 50C is light and the supply air temperature is set high.
Then, the indoor air conditioner control unit 51A of the indoor air conditioner 50A sends a signal to increase the load amount to the external air conditioner control unit 31, and the indoor air conditioner control units 51B and 51C of the indoor air conditioners 50B and 50C The signal which should reduce load amount is sent to the machine control part 31. Correspondingly, the external air conditioner control unit 31 sums up the load amounts from the indoor air conditioner control units, and determines whether to increase or decrease the output of the compressor 1 and controls it.
[0037]
Further, the indoor air conditioner control unit 51A is set to increase the degree of supercooling, the indoor air conditioner control units 51B and 51C are set to decrease the degree of supercooling, and the flow rate adjustment valves 14A, 14B, and 14C are changed. The opening degree is controlled so that the degree of supercooling is achieved.
[0038]
Here, the expansion valves 15A, 15B, and 15C only make the superheat degree of the heat exchangers 18A, 18B, and 18C constant, and do not directly control the supply air temperature and the refrigerant flow rate, but the expansion valves 15A, 15B, and 15C By controlling the opening degree of the flow rate adjusting valves 14A, 14B, 14C so as to change the degree of supercooling of the refrigerant entering, the inlet pressures of the expansion valves 15A, 15B, 15C are controlled, and the heat exchangers 18A, 18B, Since the flow rate of the refrigerant flowing through 18C changes and the amount of heat exchange also changes accordingly, the supply air temperature is controlled.
FIG. 8 is a Mollier diagram of the refrigeration cycle showing the above control procedure. In the figure, (a) shows the pressure drop due to the flow regulating valves 14A, 14B, 14C, (b) shows the controlled supercooling degree, (c) shows the pressure drop due to the expansion valves 15A, 15B, 15C, (d ) Is a supercooling portion by the supercooling heat exchanger 12.
[0039]
Since the branch unit 40 includes the supercooling heat exchanger 12, the degree of supercooling of the liquid refrigerant entering each of the flow rate adjustment valves 14A, 14B, and 14C can be increased, and the refrigerant can be reduced even if the opening degree of the flow rate adjustment valve is reduced. Does not start to expand, the control range of the flow regulating valve is expanded.
[0040]
The supercooling heat exchanger 12 is also useful for completely gasifying the returned refrigerant. That is, when the air volume suddenly decreases due to some problem in the supply air of all the indoor air conditioners 50A, 50B, 50C, the control speed of the expansion valves 15A, 15B, 15C cannot keep up and evaporates in the heat exchangers 18A, 18B, 18C. Even if the liquid refrigerant that could not be discharged flows, the supercooling heat exchanger 12 functions as a temporary heat accumulator, so that the liquid compression phenomenon that the liquid refrigerant enters the compressor 1 can be prevented.
Similarly, since the degree of superheat of the gas refrigerant of the compressor 1 can be secured by the supercooling heat exchanger 12, the degree of superheat by the expansion valves 15A, 15B, 15C of the indoor air conditioners 50A, 50B, 50C can be set small, and the heat exchanger The utilization efficiency of 18A, 18B, 18C can be increased.
[0041]
Next, the flow of the refrigerant during the all heating operation in which all the indoor air conditioners are heated will be described with reference to FIG.
When all indoor air conditioners are operated for heating, the solenoid valve 5A is opened and the solenoid valve 5B is closed in the external air conditioner, and the solenoid valves 23A, 23B, and 23C are opened in the branch unit. Control is performed so that 13A, 13B, and 13C are closed. The heat exchanger 6 of the external air conditioner functions as an evaporator, and the heat exchangers 18A, 18B, and 18C of each indoor air conditioner function as a condenser.
[0042]
That is, the high-pressure gas refrigerant from the compressor 1 of the external air handler 30 enters the branch unit 40 through the refrigerant pipe R3. The refrigerant is branched here, passes through the electromagnetic valves 23A, 23B, and 23C, enters the heat exchangers 18A, 18B, and 18C of the indoor air conditioners 50A, 50B, and 50C and is liquefied.
After that, after passing through the subcooling heat exchanger 12 of the branch unit, the refrigerant pipe R1 returns to the external conditioner 30 and enters the supercooling heat exchanger 4 via the liquid tank 27.
The refrigerant is heat-exchanged with the gas refrigerant from the heat exchanger 6 in the supercooling heat exchanger 4 to become a liquid refrigerant having an increased degree of supercooling.
[0043]
Further, the refrigerant is depressurized by the expansion valve 7, enters a low-temperature gas-liquid mixed state, and enters the heat exchanger 6. The refrigerant exchanges heat with outdoor air in the heat exchanger 6 to become a gaseous state, and proceeds to the supercooling heat exchanger 4 through the electromagnetic valve 5A. Here, as described above, the liquid refrigerant coming from the liquid tank 27 is cooled and becomes a gas refrigerant with increased superheat. Thereafter, the refrigerant returns to the compressor 1 through the accumulator 3.
Here, the supercooling heat exchanger 4 constitutes the second supercooling heat exchanger of the invention.
[0044]
During this time, the expansion valves 15A, 15B, 15C, the flow rate adjusting valve 25, the blower 21, the flow rate adjusting valves 14A, 14B, 14C, and the expansion valve 7 are controlled as follows. First, the expansion valves 15A, 15B, and 15C are held fully open by the indoor air conditioner controllers 51A, 51B, and 51C. Next, the external air conditioner control unit 31 detects the refrigerant pressure with the pressure sensor 8 and calculates the saturation temperature of the refrigerant entering the expansion valve 7. Then, the flow rate adjustment valve 25 is controlled so that the difference from the temperature detected by the temperature sensor 9, that is, the degree of supercooling becomes the degree of supercooling obtained from the relational expression between the load of the external air conditioner and the degree of supercooling. The above relational expression gives the degree of supercooling indicated by the levels D1 to D10 according to the load as shown in FIG.
Further, for example, a signal by PID control or step control is output to the blower inverter 33 so that the pressure detected by the pressure sensor 11B of the compressor 1 becomes a preset value, and the blower 21 is driven to reduce the air volume. Control.
[0045]
On the other hand, in the indoor air conditioner control units 51A, 51B, and 51C, the supply air temperatures detected by the temperature sensors 22A, 22B, and 22C are the temperatures that are previously obtained and held in the supply air temperature setting units 46A, 46B, and 46C. Calculate the degree of supercooling required to
Next, the pressure of the refrigerant is detected by the pressure sensors 16A, 16B, and 16C, the saturation temperature of the refrigerant entering each of the flow rate adjusting valves 14A, 14B, and 14C is calculated, and the saturation temperature and the temperature sensors 17A, 17B, and 17C are calculated. The actual degree of supercooling is calculated by calculating the difference from the detected temperature.
That is, when the detected supply air temperature is higher than the temperature held in the supply air temperature setting unit 46A, 46B, 46C, the flow rate adjustment valves 14A, 14B, 14C are controlled to increase the degree of supercooling, and the detected temperature is When the temperature is lower than the maintained temperature, the flow control valves 14A, 14B, and 14C are controlled so as to reduce the degree of supercooling.
[0046]
In addition, the external air conditioner control unit 31 controls the expansion valve 7 so that the degree of superheat of the heat exchanger 6 is kept constant based on the detected temperatures of the temperature sensors 10A and 10B, similarly to the indoor air conditioner during cooling operation. Control.
Here, if the load of each indoor air conditioner 50A, 50B, 50C is equivalent, the opening degree of each flow regulating valve 14A, 14B, 14C will become the same. In this case, the refrigerant is equally distributed from the branch unit 40 to the indoor air conditioners 50A, 50B, and 50C, and the supply air temperatures are the same.
[0047]
Here, for example, it is assumed that the load on the indoor air conditioner 50A is heavy and the supply air temperature is set high, and the load on the indoor air conditioners 50B and 50C is light and the supply air temperature is set low.
Then, the indoor air conditioner control unit 51A of the indoor air conditioner 50A sends a signal to increase the load amount to the external air conditioner control unit 31, and the indoor air conditioner control units 51B and 51C of the indoor air conditioners 50B and 50C The signal which should reduce load amount is sent to the machine control part 31. Correspondingly, the external air conditioner control unit 31 sums up the load amounts from the indoor air conditioner control units, and determines whether to increase or decrease the output of the compressor 1 and controls it.
[0048]
Further, the indoor air conditioner control unit 51A is set to reduce the degree of supercooling, the indoor air conditioner control units 51B and 51C are set to increase the degree of supercooling, and the flow rate adjustment valves 14A, 14B, and 14C are changed. The opening degree is controlled so that the degree of supercooling is achieved.
FIG. 11 is a Mollier diagram of the refrigeration cycle showing the above control procedure. In the figure, (a) is the pressure drop due to the expansion valves 15A, 15B and 15C, (b) is the supercooling portion due to the supercooling heat exchanger 12, and (c) is the pressure drop due to the flow rate adjusting valves 14A, 14B and 14C. (D) is the controlled degree of supercooling.
[0049]
In this heating operation, the degree of supercooling is controlled by the flow rate adjustment valve, so that the degree of supercooling becomes large and a large amount of liquid refrigerant accumulates in the heat exchangers 18A, 18B, 18C, causing the entire refrigeration cycle to run out of refrigerant. The occurrence of a malfunction is prevented.
Furthermore, the subcooler heat exchanger 4 serves to completely liquefy the returned refrigerant. In other words, when the air supply suddenly decreases due to some problem with the air supply of the indoor air conditioners 50A, 50B, 50C, the control speed of the flow rate adjusting valves 14A, 14B, 14C cannot catch up, and uncondensed gas refrigerant is present in the external air conditioner 30. Even if it flows, since the supercooling heat exchanger 4 works as a temporary heat accumulator, it is possible to prevent a decrease in controllability due to the gas refrigerant entering the expansion valve 7. Further, even if the air volume is temporarily reduced by the control of the blower 21 of the external air conditioner 30 and the non-evaporated liquid refrigerant flows into the compressor 1, it can be similarly prevented.
Similarly, since the degree of superheat of the gas refrigerant entering the compressor 1 can be increased by the supercooling heat exchanger 4, the discharge temperature of the compressor 1 becomes higher, and the heating capacity is improved accordingly.
[0050]
Next, the operation of the cooling / heating simultaneous cooling main operation in which the cooling operation and the heating operation are performed in parallel and the load of the indoor air conditioner is larger in the cooling operation than in the heating operation will be described. FIG. 12 shows the flow of the refrigerant at this time. Here, for example, it is assumed that the indoor air conditioner 50A is in a heating operation and the indoor air conditioners 50B and 50C are in a cooling operation as an example.
First, in the external controller, the solenoid valve 5B is opened and the solenoid valve 5A is closed. In the branch unit, the solenoid valves 23A, 13B, and 13C are opened, and the solenoid valves 13A, 23B, and 23C are closed. The
The heat exchanger 6 of the external air conditioner and the indoor air conditioner 18A function as a condenser, and the heat exchangers 18B and 18C of the indoor air conditioner function as an evaporator.
[0051]
In the external air conditioner 30, the high-pressure gas refrigerant from the compressor 1 enters the heat exchanger 6 from the electromagnetic valve 5B and is liquefied here. The refrigerant exiting the heat exchanger 6 passes through the supercooling heat exchanger 4 and the liquid tank 27 and enters the supercooling heat exchanger 12 of the branch unit 40 through the refrigerant pipe R1.
The high-pressure gas refrigerant from the compressor 1 also enters the branch unit 40 through the refrigerant pipe R3. The refrigerant via the refrigerant pipe R3 passes through the electromagnetic valve 23A and enters the heat exchanger 18A of the indoor air conditioner 50A, where it is liquefied.
[0052]
The refrigerant that has entered the subcooling heat exchanger 12 of the branch unit via the refrigerant pipe R1 is heat-exchanged with the gas refrigerant that has come out of the heat exchangers 18B and 18C of the indoor air conditioners 50B and 50C, and the degree of supercooling is increased. Becomes a refrigerant.
This refrigerant once merges with the liquid refrigerant coming from the heat exchanger 18A of the indoor air conditioner 50A through the branch pipe, and then enters the indoor air conditioners 50B and 50C in parallel. Here, the pressure is reduced by the flow rate adjusting valves 14B and 14C, and then the expansion valves 15B and 15C, respectively, and enters a heat exchanger 18B and 18C.
[0053]
The refrigerant exchanges heat with the return air in the heat exchangers 18B and 18C, and becomes a gaseous refrigerant. And it returns to the supercooling heat exchanger 12 through the electromagnetic valves 13B and 13C, and cools the liquid refrigerant which enters from the external air conditioner 30 via the refrigerant pipe R1.
The refrigerant that has exited the supercooling heat exchanger 12 returns to the compressor 1 of the external air conditioner 30 via the refrigerant pipe R2.
[0054]
During this time, the expansion valve 7, the flow adjustment valve 25, the blower 21, the flow adjustment valve 14A of the indoor air conditioner 50A, the expansion valve 15A, the flow adjustment valves 14B and 14C of the indoor air conditioners 50B and 50C, and the expansion valve 15B. , 15C is controlled as follows.
First, the expansion valve 7 of the external air conditioner control unit 31 is held in a fully opened state. The flow rate adjustment valve 25 is controlled so that the degree of supercooling calculated from the pressure sensor 8 and the temperature sensor 9 becomes the degree of supercooling obtained in FIG. 7 as in the control during the cooling operation.
[0055]
As for the blower 21, similarly to the control of the cooling only operation, the inverter 33 is driven so that the pressure detected by the discharge-side pressure sensor 11 </ b> A becomes a preset value, and the air volume control is performed.
On the other hand, the indoor air conditioner controller 51A of the indoor air conditioner 50A holds the expansion valve 15A fully open. Then, the flow rate adjusting valve 14A is controlled so as to have a necessary degree of supercooling based on the set supply air temperature, similarly to the control of the flow rate adjusting valve of the indoor air conditioner during the heating only operation.
[0056]
In addition, in the indoor air conditioner control units 51B and 51C of the indoor air conditioners 50B and 50C, the degree of superheat of the expansion valves 15B and 15C becomes constant as in the control of the expansion valve of the indoor air conditioner during the cooling only operation. Similarly, the flow rate adjusting valves 14B and 14C are also controlled so as to obtain a necessary degree of supercooling based on the set supply air temperature.
In addition, when the load of each indoor air conditioner changes, since it is the same as that of the indoor air conditioner of the same operation mode in a cooling only operation or a heating operation, description is abbreviate | omitted.
FIG. 13 is a Mollier diagram of the refrigeration cycle showing the above control procedure. In the figure, (a) is the degree of supercooling controlled by the flow adjustment valve of the external air conditioner or indoor air conditioner 50A, (b) is the pressure drop due to the flow adjustment valve of the external air conditioner or indoor air conditioner 50A, and (c). Is a supercooling portion by the supercooling heat exchanger 12, (d) is a pressure drop by the flow rate adjustment valve of the indoor air conditioner 50B or 50C, and (e) is a supercooling controlled by the flow rate adjustment valve of the indoor air conditioner 50B or 50C. Degree (f) is the pressure drop due to the expansion valve of the indoor air conditioner 50B or 50C.
[0057]
Next, in the simultaneous cooling and heating operation, the operation of the cooling and heating simultaneous heating main operation in which the load of the indoor air conditioner is larger in the heating operation than in the cooling operation will be described with reference to FIG. 14 showing the refrigerant flow. Here, for example, it is assumed that the indoor air conditioner 50A is in a cooling operation and the indoor air conditioners 50B and 50C are in a heating operation as an example.
First, in the external controller, the solenoid valve 5A is opened and the solenoid valve 5B is closed, and in the branch unit, the solenoid valves 13A, 23B, and 23C are opened, and the solenoid valves 23A, 13B, and 13C are closed. The The heat exchanger 6 of the external air conditioner and the heat exchanger 18A of the indoor air conditioner function as an evaporator, and the heat exchangers 18B and 18C of the indoor air conditioner function as a condenser.
[0058]
In this operation, the high-pressure gas refrigerant from the compressor 1 of the external air conditioner 30 enters the branch unit 40 via the refrigerant pipe R3. Here, the refrigerant passes through the electromagnetic valves 23B and 23C, enters the heat exchangers 18B and 18C of the indoor air conditioners 50B and 50C, and is liquefied.
The refrigerant that has exited the heat exchangers 18B and 18C merges in the branch pipe of the branch unit 40, and part of the refrigerant goes to the indoor air conditioner 50A, and the rest passes through the supercooling heat exchanger 12 and the refrigerant pipe R1, and then the liquid in the external air conditioner. It enters the tank 27 and then enters the supercooling heat exchanger 4.
[0059]
In the external air conditioner, the refrigerant is heat-exchanged with the gas refrigerant from the heat exchanger 6 in the supercooling heat exchanger 4, and becomes a liquid refrigerant with increased supercooling. Then, the refrigerant is decompressed by the expansion valve 7 to be in a low-temperature gas-liquid mixed state and enters the heat exchanger 6. The refrigerant that has been exchanged with the outdoor air in the heat exchanger 6 and turned into a gaseous state passes through the supercooling heat exchanger 4 via the electromagnetic valve 5A, and cools the liquid refrigerant coming from the liquid tank 27 as described above. It becomes a gas refrigerant with increased superheat.
[0060]
On the other hand, the refrigerant that has entered the indoor air conditioner 50A is decompressed by the expansion valve 15A and is in a low-temperature gas-liquid mixed state. Next, heat is exchanged with the return air in the heat exchanger 18A to form a gaseous refrigerant. Then, it goes to the external air conditioner 30 through the refrigerant pipe R2 through the electromagnetic valve 13A.
The refrigerant merges with the refrigerant that has exited the supercooling heat exchanger 4 in the external controller 30, and returns to the compressor 1 through the accumulator 3.
[0061]
During this time, the expansion valve 7, the flow adjustment valve 25, the blower 21, the flow adjustment valve 14A of the indoor air conditioner 50A, the expansion valve 15A, the flow adjustment valves 14B and 14C of the indoor air conditioners 50B and 50C, and the expansion valve 15B. , 15C is controlled as follows.
First, the external air conditioner control unit 31 controls the expansion valve 7 so that the degree of superheat becomes constant as in the control during the heating only operation. Similarly, the flow rate adjusting valve 25 is controlled so as to have a value obtained from the relationship between the supercooling degree level and the external compressor load shown in FIG.
As for the blower 21, similarly to the control during the heating only operation, the blower inverter 33 is driven so that the pressure detected by the pressure sensor 11 </ b> B becomes a preset value, and the air volume control is performed.
[0062]
The control by the indoor air conditioner control unit 51A of the indoor air conditioner 50A is the same as the control of the indoor air conditioners 50B and 50C in the cooling and heating simultaneous cooling main operation, and therefore will be omitted. The control of the indoor air conditioner controllers 51B and 51C of the indoor air conditioners 50B and 50C is the same as that of the indoor air conditioner 50A during the cooling and heating simultaneous cooling main operation.
[0063]
Next, for example, when the indoor air conditioner 50A is in the heating operation, the indoor air conditioners 50B and 50C are in the cooling operation, and the cooling load and the heating load are the same, the heat exchanger 6 of the external conditioner 30 is condensed with respect to the difference between the two loads. Therefore, the flow rate adjusting valve 25 is closed and the blower 21 is also stopped. And all the refrigerant | coolants which flowed 50 A of indoor air conditioners will flow into the indoor air conditioners 50B and 50C mutually parallel, and heat amount balances them.
[0064]
The flow of control in the above-described external air conditioner control unit and indoor air conditioner control unit is briefly shown in FIGS.
Specifically, as shown in FIG. 15, the external air conditioner control unit first inputs information on the operating status such as the load amount of the indoor air conditioner from the indoor air conditioner control units 51 </ b> A to 51 </ b> C in step 101. Accumulated for each operation mode. Then, in step 103, the integrated load amount for each mode is compared. If the cooling load is large, the process proceeds to step 104. If the heating load is large, the process proceeds to step 113. If both loads are the same, the process proceeds to step 124.
[0065]
When the cooling load is large, first, at step 104, a control signal corresponding to the load amount of the cooling load is sent to the inverter 32 to drive the compressor 1, and at step 105, the heat exchanger 6 is used as a condenser. The working mode is assumed.
In the next step 106, the heat exchanger load amount is obtained as a difference between the cooling load and the heating load, and in step 107, the target subcooling degree is obtained by calculation or graph reading.
[0066]
In step 108, the actual degree of supercooling is obtained from the difference between the refrigerant saturation temperature based on the detected value of the pressure sensor 8 and the detected temperature of the temperature sensor 9. In step 109, the flow rate adjustment valve 25 is controlled so that the control supercooling degree and the actual supercooling degree coincide with each other.
Thereafter, in step 110, the discharge pressure of the compressor 1 is detected by the pressure sensor 11A. In step 111, the inverter 33 is driven so that the discharge pressure becomes a preset value, and the air volume control of the blower 21 is performed. Then, the process returns to step 101.
[0067]
Next, when the heating load is large, in step 113, a control signal corresponding to the load amount of the heating load is sent to the inverter 32 to drive the compressor 1, and in step 114, the heat exchanger 6 evaporates. The mode that works as a vessel.
In the next step 115, the heat exchanger load amount is obtained as a difference between the heating load and the cooling load, and in step 116, the target subcooling degree is obtained by calculation or graph reading.
[0068]
In step 117, the actual degree of supercooling is obtained from the difference between the refrigerant saturation temperature based on the detected value of the pressure sensor 8 and the detected temperature of the temperature sensor 9. In step 118, the flow rate adjustment valve 25 is controlled so that the control supercooling degree matches the actual supercooling degree.
Subsequently, in step 119, the degree of superheat of the heat exchanger 6 is obtained from the detected temperatures of the temperature sensors 10A, 10B, and in step 120, the expansion valve 7 is controlled so as to keep it constant.
Thereafter, in step 121, the suction pressure of the compressor 1 is detected by the pressure sensor 11B. In step 122, the air volume control of the blower 21 is performed so that the pressure becomes a preset value. Then, the process returns to step 101.
[0069]
When the cooling load and the heating load are the same, the flow rate adjustment valve 25 is closed in step 124, and the blower 21 is stopped in step 125.
[0070]
On the other hand, in each indoor air conditioner control unit, as shown in FIGS. 16 and 17, the blower 24 is first activated in step 201. Next, at step 202, the indoor temperature of the air-conditioning zone is detected by the temperature sensor 45 and held in the temperature holding unit 52. In step 203, the set room temperature is input from the room temperature setter 49. Next, at step 204, the supply air temperature at startup is calculated. Further, in step 205, the return air temperature of the indoor air conditioner is detected by the temperature sensor 26, and the supply air temperature and the return air temperature set in the calculation in step 206 are compared to determine whether to perform the cooling operation or the heating operation. Determine the mode.
[0071]
In the cooling operation mode, in step 207, the solenoid valve is first switched to the cooling mode. In step 208, the actual supply air temperature is detected by the temperature sensor 22, and the supply air temperature (detected temperature) detected in step 209 is detected. The set supply air temperature (set temperature) is compared. If the detected temperature is low, the process proceeds to step 210. If the detected temperature is high, the process proceeds to step 211. If the detected temperature is the same, the process proceeds to step 212.
In step 210, the current degree of supercooling is set to be small. In step 211, the degree of supercooling is set to be large. In step 212, the current degree of supercooling is detected, and the supercooling value set in step 213 is set. The flow rate adjustment valve 14 is controlled so as to be at a degree. Further, in step 214, information on the current operation state of the indoor air conditioner is sent to the external air conditioner.
[0072]
Next, the degree of superheat is detected by the temperature sensors 19 and 20 at step 215, and the expansion valve 15 is controlled at step 216 based on that.
Next, in step 217, it is checked whether or not the supply air temperature change time has come. While the supply air temperature change time has not elapsed, the process returns to step 207, and if the set supply air temperature change time has already elapsed, the process proceeds to step 218.
In step 218, the room temperature is detected by the temperature sensor 45, and in step 219, the change direction of the room temperature is obtained by comparison with the previous detected temperature. In step 220, the amount of change in the supply air temperature is calculated, the supply air temperature is updated, and then the process returns to step 205.
[0073]
On the other hand, in the heating mode, the solenoid valve is switched to the heating mode in step 221, the actual supply air temperature is detected in step 222, the detected supply air temperature is compared with the set supply air temperature in step 223, If the detected temperature is low, the process proceeds to step 224. If the detected temperature is high, the process proceeds to step 225. If the detected temperature is the same, the process proceeds to step 226.
In step 224, the current degree of supercooling is set to be reduced. In step 225, the degree of supercooling is set to be increased.
In step 226, the current degree of supercooling is detected, and in step 227, the flow rate adjusting valve is controlled.
Next, in step 228, information on the operating state of the indoor air conditioner is sent to the external air conditioner.
[0074]
Thereafter, in step 229, it is checked whether the supply air temperature change time has elapsed.
If the supply air temperature change time has not yet elapsed, the process returns to step 221, and if it has elapsed, the process proceeds to step 230.
Further, the room temperature is detected at step 230, and the change direction of the room temperature is obtained by comparison with the previous detected temperature at step 231. In step 232, the amount of change in the supply air temperature is calculated, the supply air temperature is updated, and then the process returns to step 205.
[0075]
The present embodiment described above can be briefly summarized as follows. First, in a heat pump air conditioner piped in parallel from an external air conditioner to a plurality of indoor air conditioners via a branch unit, the air from the indoor air conditioner is guided to a plurality of air conditioning zones by a duct and supplied to each air conditioning zone. The temperature can be changed, the branch unit is equipped with a supercooling heat exchanger, a solenoid valve that can be selected for cooling operation and heating operation by switching it, and the external air conditioner is equipped with a supercooling heat exchanger on the liquid pipe side. Provided a flow control valve and an expansion valve. A flow control valve and an expansion valve are provided on the liquid pipe side of the heat exchanger of the indoor air conditioner, and the degree of supercooling is controlled by the flow control valve so that the supply air temperature changes according to the load of each indoor air conditioner. During the cooling operation, the expansion valve is controlled so that the degree of superheat of the heat exchanger becomes constant. On the other hand, in an external air conditioner, the flow rate adjustment valve is controlled to have a degree of supercooling according to the load of the external air conditioner. When the heat exchanger is in the condensation mode, the expansion valve is fully opened, and in the evaporation mode. Was controlled so that the degree of superheat of the heat exchanger was constant. The supply air temperature of the indoor air conditioner starts with a value determined from the set indoor temperature and the detected indoor temperature at the start-up, and after a predetermined time has elapsed, the supplied air temperature is based on the set indoor temperature, the detected indoor temperature, and the amount of change thereof. Were changed sequentially.
Thereby, according to the individual request | requirement of each air-conditioning zone, it has the effect that cooling operation and heating operation can be performed arbitrarily, and also supply air temperature can be changed freely. Moreover, since the indoor temperature of each air-conditioning zone can be arbitrarily controlled by the change of the supply air temperature without being affected by the load state of other indoor air conditioners, there is an effect that a comfortable environment can be obtained.
[0076]
Therefore, it is not necessary to install air conditioners in a large number of individual air conditioning zones, and only a simple duct connection is required, so that maintainability is improved.
Further, during the cooling operation, the supercooling degree of the refrigerant entering the flow rate adjustment valve of the indoor air conditioner is increased by the supercooling heat exchanger 12 in particular, so that the adjustment range of the flow rate adjustment valve can be expanded and a stable refrigeration cycle can be obtained. It is done.
Further, when the air supply amount of the indoor air conditioner suddenly decreases during the cooling operation, the supercooling heat exchanger 12 acts as a temporary heat accumulator, and the liquid compression phenomenon that the liquid refrigerant enters the compressor 1 of the external air conditioner is prevented. Even when the supply air volume suddenly decreases during the heating operation, the supercooling heat exchanger 4 of the external air conditioner acts as a temporary heat accumulator and promotes reliable liquefaction of the refrigerant, thereby controlling the expansion valve 7. Is prevented.
[0077]
Even if the installation locations of the indoor air conditioners 50A, 50B, and 50C vary and there is a difference in the pipe length from the external air conditioner 30, the state of the refrigerant between the expansion valve and the flow control valve of each indoor air conditioner can be changed. Since it can be the same, the same air conditioning capability can be obtained without taking pipe pressure loss into consideration during installation work.
[0078]
In the embodiment, the air exchanged by each indoor air conditioner is led to each air conditioning zone by a duct. However, the present invention is not limited to this. For example, air is supplied by using the ceiling or floor under the building as a supply chamber. The same can be applied to a ductless system that guides.
Further, in this embodiment, the relationship table shown in FIG. 4 is used to determine the startup air supply temperature from the difference between the set room temperature and the detected room temperature. When the difference in temperature is within a predetermined range with 0, the room temperature (detection room temperature) remains unchanged, and when the difference exceeds the predetermined range, the value is adjusted to the room temperature. Can be set.
[0079]
FIG. 19 shows a second embodiment of the present invention. In this embodiment, with respect to the refrigerant circuit of the first embodiment described above, the branch unit is abolished and a supercooling heat exchanger suitable for the branch unit is provided for each indoor air conditioner.
That is, the refrigerant pipes R1 ', R2', R3 'extending from the external air conditioner 30 are branched and connected in parallel to the indoor air conditioners 50A', 50B ', 50C'. In each indoor air conditioner, the refrigerant pipe R1 'passes through the supercooling heat exchangers 12A, 12B, and 12C, and then is connected to the flow rate adjustment valves 14A, 14B, and 14C.
The refrigerant pipe R2 ′ enters the other passages of the supercooling heat exchangers 12A, 12B, and 12C, and is connected to the gas pipe side of the heat exchangers 18A, 18B, and 18C via the electromagnetic valves 13A ′, 13B ′, and 13C ′. It is connected. Further, the refrigerant pipe R3 'is connected to the gas pipes of the heat exchangers 18A, 18B, 18C via electromagnetic valves 23A', 23B ', 23C'.
[0080]
The solenoid valves 13A 'and 23A', 13B 'and 23B', and 13C 'and 23C' are controlled so that when one is open, the other is closed, as in the first embodiment.
Other configurations are the same as those of the first embodiment. Since the refrigerant flow in each operation mode is the same as that in the first embodiment, the description of the operation is omitted.
[0081]
According to this embodiment, the same effect as that of the first embodiment is provided, and the supercooling heat exchanger is provided separately for each indoor air conditioner. Passing through the heat exchanger, the degree of supercooling can be increased, and the supercooled heat exchanger is advantageous in that it can be handled easily, is small and inexpensive.
[0082]
In the above embodiment, three indoor air conditioners are connected. However, the number of indoor air conditioners is not limited to this, and two or four or more indoor air conditioners can be similarly implemented. If there is an indoor air conditioner that does not supply air, the flow control valve can be fully closed and not operated.
Also, a plurality of branch units may be provided, and a plurality of indoor air conditioners may be connected to each branch unit. Furthermore, the first embodiment and the second embodiment may be combined.
[0083]
【The invention's effect】
As described above, the present invention provides an air conditioner in which a plurality of indoor air conditioners are connected in parallel to an external air conditioner, and a gas pipe of a heat exchanger of each indoor air conditioner and the external air conditioner is a high pressure gas pipe or a low pressure gas pipe. Can be selected for each indoor air conditioner, air conditioning operation and heating operation can be selected for each indoor air conditioner, the air supply of each indoor air conditioner is guided to multiple air conditioning zones by ducts, and the air supply for each air conditioning zone Each room temperature adjustment of the air conditioning zone is performed according to the temperature change, and there is an effect that a comfortable environment can be obtained that meets the requirements of all the air conditioning zones.
And since it is not necessary to install a large number of air conditioners individually, the maintainability is improved, and at the same time of cooling and heating, heat energy is transferred between the indoor air conditioners, so that a significant energy saving effect is obtained.
[0084]
Furthermore, the air conditioning is performed so that the refrigerant can be supplied at an arbitrary supply air temperature by controlling the flow rate adjusting means so that the degree of supercooling of the refrigerant becomes a value determined according to the supply air temperature of the indoor air conditioner. . In addition, because the expansion valve of the indoor air conditioner is not affected by other indoor air conditioners, there is no difference in capacity depending on the installation location of each indoor air conditioner. There is an effect that construction can be simplified.
[0085]
In addition, the control range of the flow rate by the flow rate adjusting means is expanded by providing the first subcooling heat exchanger between the liquid pipes and low pressure gas pipes that are directed to the plurality of indoor air conditioners. Thereby, for example, even if the supply air volume of the indoor air conditioner is suddenly reduced, the returned refrigerant is reliably gasified by the action of the regenerator of the supercooling heat exchanger, and the compressor is prevented from being damaged.
Further, by providing the second supercooling heat exchanger between the liquid pipe and the low-pressure gas pipe directed to the heat exchanger of the external air conditioner, the degree of superheat of the gas refrigerant entering the compressor of the external air conditioner can be increased. In addition, the heating capacity is improved, and even when the supply air temperature of the indoor air conditioner is suddenly changed, it is possible to promote the reliable liquefaction of the return refrigerant by the heat accumulator action of the supercooling heat exchanger.
[0086]
Furthermore, the supply air temperature of the indoor air conditioner is started at the supply air temperature determined by the indoor temperature and the set temperature detected by the air conditioning zone at the start-up, and the supply air temperature is set with the change in the indoor temperature and the indoor temperature. By supplying air at a temperature determined by the temperature, the room temperature can be quickly brought to the set temperature, and there is an effect that comfortable air conditioning can be obtained without causing hunting.
[Brief description of the drawings]
FIG. 1 is a diagram showing a system configuration of a first exemplary embodiment of the present invention.
FIG. 2 is a refrigerant circuit diagram in the example.
FIG. 3 is a diagram illustrating a control device in an indoor air conditioner and an external air conditioner.
FIG. 4 is a graph showing a relationship among a detected room temperature, a set room temperature, and a supply air temperature at startup.
FIG. 5 is a graph showing a change amount relationship between a detected indoor temperature, a set indoor temperature, and a supply air temperature during operation.
FIG. 6 is a diagram showing a refrigerant flow during a cooling only operation.
FIG. 7 is a graph showing the relationship between the load on the external air conditioner and the degree of supercooling during the cooling only operation.
FIG. 8 is a Mollier diagram of a refrigeration cycle showing a control procedure during a cooling only operation.
FIG. 9 is a diagram illustrating a refrigerant flow of a refrigerant during a heating only operation.
FIG. 10 is a graph showing the relationship between the load on the external air conditioner and the degree of supercooling during the heating only operation.
FIG. 11 is a Mollier diagram of a refrigeration cycle showing a control procedure during a heating only operation.
FIG. 12 is a diagram showing a refrigerant flow during the cooling and heating simultaneous cooling main operation.
FIG. 13 is a Mollier diagram of a refrigeration cycle showing a control procedure at the time of cooling and heating simultaneous cooling main operation.
FIG. 14 is a diagram showing the refrigerant flow in the main heating and cooling simultaneous heating main operation.
FIG. 15 is a flowchart showing a control flow in the external air conditioner control unit.
FIG. 16 is a flowchart showing a flow of control in the indoor air conditioner control unit.
FIG. 17 is a flowchart showing a flow of control in the indoor air conditioner control unit.
FIG. 18 is a graph showing a modified example of the relationship among the detected room temperature at startup, the set room temperature, and the supply air temperature.
FIG. 19 is a system configuration diagram showing a second embodiment;
[Explanation of symbols]
  1 Compressor
  3 Accumulator
  4 Supercooling heat exchanger(Second supercooling heat exchanger)
  5A, 5B solenoid valve
  6 Heat exchanger
  7 Expansion valve
  8 Pressure sensor
  9 Temperature sensor
  10A, 10B Temperature sensor
  11A, 11B Pressure sensor
  12 Supercooling heat exchanger(First supercooling heat exchanger)
  13A, 13B, 13C, 23A, 23B, 23C Solenoid valve
  13A ', 13B', 13C ', 23A', 23B ', 23C' Solenoid valve
  14A, 14B, 14C Flow control valve
  15A, 15B, 15C expansion valve
  16A, 16B, 16C Pressure sensor
  17A, 17B, 17C Temperature sensor
  18A, 18B, 18C heat exchanger
  19A, 19B, 19C, 20A, 20B, 20C Temperature sensor
  21 Blower
  22A, 22B, 22C, 26A, 26B, 26C Temperature sensor
  24A, 24B, 24C Blower
  25 Flow control valve
  27 Liquid tank
  30 External air conditioner
  31 External controller control unit
  34, 35, 48 Drive controller
  36 Temperature transducer
  37 Pressure transducer
  39A, 39B, 39C, 41A, 41B, 41C Drive control unit
  40 branch unit
  42A, 42B, 42C, 44A, 44B, 44C Temperature converter
  43A, 43B, 43C Pressure transducer
  45A, 45B, 45C Temperature sensor
  46A, 46B, 46C Supply air temperature setting section
  47A, 47B, 47C Duct
  48A, 48B, 48C Drive controller
  49A, 49B, 49C Room temperature setting device
  50A, 50B, 50C, 50A ', 50B', 50C 'Indoor air conditioner
  51A, 51B, 51C Indoor air conditioner controller
  52A, 52B, 52C Temperature holding part
  R1, R2, R3, R1 ', R2', R3 'Refrigerant piping
  ZA, ZB, ZC Air conditioning zone

Claims (6)

熱交換器、該熱交換器に付設された膨張弁、該膨張弁の手前に設けられた流量調整手段、および冷媒の温度と圧力の値より該流量調整手段を制御する第１の制御手段を備える外調機と、
それぞれ熱交換器、該熱交換器に付設された膨張弁、該膨張弁の手前に設けられた流量調整手段、および冷媒の温度と圧力の値より該流量調整手段を制御する第２の制御手段を備え、冷凍サイクルの液管と高圧ガス管と低圧ガス管を形成する冷媒配管により前記外調機に並列に接続された複数の室内空調機からなり、
各室内空調機の給気を各空調ゾーンごとに導くとともに、
外調機の熱交換器に接続されたガス管を該外調機の熱交換器に向かう高圧ガス管または低圧ガス管に選択的に接続可能の第１の切り換え手段と、
各室内空調機の熱交換器に接続されたガス管を前記高圧ガス管または低圧ガス管に選択的に接続可能の第２の切り換え手段を有して、
それぞれの室内空調機を個別に冷房運転または暖房運転に選択的に制御し、その給気温度を変更することによりそれぞれの空調ゾーンの室内温度を制御するように構成されたことを特徴とする空気調和装置。A heat exchanger, an expansion valve attached to the heat exchanger, a flow rate adjusting means provided in front of the expansion valve, and a first control means for controlling the flow rate adjusting means based on the temperature and pressure values of the refrigerant An external air conditioner,
A heat exchanger, an expansion valve attached to the heat exchanger, a flow rate adjusting means provided in front of the expansion valve, and a second control means for controlling the flow rate adjusting means based on refrigerant temperature and pressure values Comprising a plurality of indoor air conditioners connected in parallel to the external air conditioner by refrigerant pipes forming a liquid pipe, a high pressure gas pipe and a low pressure gas pipe of a refrigeration cycle,
While guiding the air supply of each indoor air conditioner for each air conditioning zone,
First switching means capable of selectively connecting a gas pipe connected to a heat exchanger of the external air conditioner to a high-pressure gas pipe or a low-pressure gas pipe directed to the heat exchanger of the external air conditioner;
A second switching means capable of selectively connecting a gas pipe connected to a heat exchanger of each indoor air conditioner to the high-pressure gas pipe or the low-pressure gas pipe;
Air that is configured to control each room air conditioner individually in cooling operation or heating operation, and to control the indoor temperature in each air conditioning zone by changing the supply air temperature. Harmony device. 前記室内空調機の第２の制御手段は、冷房運転時には当該室内空調機の膨張弁にはいる冷媒の過冷却度を給気温度に応じて変化させるように当該室内空調機の流量調整手段を制御し、暖房運転時は当該室内空調機の熱交換器を出た冷媒の過冷却度を給気温度に応じて変化させるように当該室内空調機の流量調整手段を制御するものであることを特徴とする請求項１記載の空気調和装置。The second control means of the indoor air conditioner includes a flow rate adjusting means for the indoor air conditioner so as to change the degree of supercooling of the refrigerant entering the expansion valve of the indoor air conditioner according to the supply air temperature during the cooling operation. Controlling the flow rate adjusting means of the indoor air conditioner to change the degree of supercooling of the refrigerant that has exited the heat exchanger of the indoor air conditioner according to the supply air temperature during heating operation. The air conditioner according to claim 1, wherein 前記外調機の第１の制御手段は、外調機の熱交換器が凝縮器として作用するときは該外調機の熱交換器を出る冷媒の過冷却度が該熱交換器の負荷に応じて決定される値になるように前記外調機の流量調整手段を制御し、外調機の熱交換器が蒸発器として作用するときは外調機の膨張弁にはいる冷媒の過冷却度が外調機の熱交換器の負荷に応じて決定される値になるよう前記外調機の流量調整手段を制御するものであることを特徴とする請求項１または２記載の空気調和装置。When the heat exchanger of the external air conditioner acts as a condenser, the first control means of the external air conditioner determines the degree of supercooling of the refrigerant that exits the heat exchanger of the external air conditioner as a load on the heat exchanger. The flow control means of the external air conditioner is controlled to a value determined accordingly, and when the heat exchanger of the external air conditioner acts as an evaporator, the supercooling of the refrigerant entering the expansion valve of the external air conditioner The air conditioner according to claim 1 or 2, wherein the flow rate adjusting means of the external air conditioner is controlled so that the degree becomes a value determined according to the load of the heat exchanger of the external air conditioner. . 前記室内空調機の少なくとも１つにおいてその熱交換器が蒸発器として作用するとき前記室内空調機に向かう液管と外調機に向かう低圧ガス管の間に、互いの間で熱交換を行う第１の過冷却熱交換器が設けられていることを特徴とする請求項１、２または３記載の空気調和装置。In at least one of the indoor air conditioners, when the heat exchanger acts as an evaporator, heat exchange is performed between the liquid pipe toward the indoor air conditioner and the low pressure gas pipe toward the external conditioner. 4. The air conditioning apparatus according to claim 1, wherein one supercooling heat exchanger is provided. 前記外調機の熱交換器が蒸発器として作用するとき前記外調機の熱交換器に向かう液管と低圧ガス管の間に、互いの間で熱交換を行う第２の過冷却熱交換器が設けられていることを特徴とする請求項１、２、３または４記載の空気調和装置。A second supercooling heat exchange for exchanging heat between the liquid pipe and the low-pressure gas pipe toward the heat exchanger of the external air conditioner when the heat exchanger of the external air conditioner acts as an evaporator An air conditioner according to claim 1, 2, 3 or 4, wherein a vessel is provided. 前記給気温度は、室内空調機が起動時にはそれぞれの空調ゾーンの室内温度と設定温度より決定される値に設定され、その後は設定温度と室内温度により決定される値とその室内温度の変化による補正値によって決定される値に基づいて変更されるものであることを特徴とする請求項１、２、３、４または５記載の空気調和装置。The supply air temperature is set to a value indoor air conditioner which is determined from the indoor temperature and the set temperature of each air conditioning zone is at startup, then due to changes in the values and their interior temperature determined by the set temperature and the room temperature 6. The air conditioner according to claim 1, wherein the air conditioner is changed based on a value determined by the correction value .
JP06022896A 1996-02-22 1996-02-22 Air conditioner Expired - Fee Related JP3729552B2 (en)

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