JP3567168B2

JP3567168B2 - Thermal storage heat pump air conditioner for cold regions

Info

Publication number: JP3567168B2
Application number: JP2000300555A
Authority: JP
Inventors: 剛遠藤; 俊幸北條; 一浩土橋; 訓良山田
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2000-09-28
Filing date: 2000-09-28
Publication date: 2004-09-22
Anticipated expiration: 2020-09-28
Also published as: KR20020025648A; KR100419407B1; JP2002106917A

Description

【０００１】
【発明の属する技術分野】
本発明は、蒸気圧縮冷凍サイクルを利用した蓄熱利用空調運転を行なう蓄熱式ヒートポンプ空気調和機に係わり、特に、特に冬期に室外空気温度が例えば−１５℃以下に低下するような寒冷地で利用する蓄熱式ヒートポンプ式空気調和機に好適である。
【０００２】
【従来の技術】
蓄冷運転と冷房運転、蓄熱運転と暖房運転を交互又は同時に運転する制御によって、能力を安定にすることが知られ、例えば特開平９−１３８０２５号公報に記載されている。
【０００３】
【発明が解決しようとする課題】
上記従来技術においては、冬季の最低外気温度が−１０℃〜−１５℃以下に達するような寒冷地域に関しては特に考慮されておらず、寒冷地域においては蓄熱を使用しない空気熱源式ヒートポンプは、十分な熱源が得られないため能力の低下が大きくなる。これに対して、蓄熱を熱源として利用した場合、外気温度によらず熱源が確保されるため、寒冷地域においても外気低温時の暖房能力の維持や消費電力低減に対して非常に効果が大きい。
【０００４】
しかし、水を蓄熱媒体として用いる氷蓄熱式エアコンでは、暖房運転においては一般に顕熱を熱源として利用しているため、潜熱を利用する冷房運転に比較して蓄熱量は小さくなる。暖房運転においても潜熱まで利用することは可能であるが、伝熱管表面に氷が生成することによる伝熱性能の低下により、性能の低下が著しいため有効な方法ではない。したがって、寒冷地域においても十分な性能を長時間得るためには、蓄熱量を大きくする必要があり、蓄熱槽を大型化して蓄熱媒体量を増やすか、利用温度を拡大するため蓄熱終了水温を高くする必要がある。蓄熱終了水温については、ヒートポンプ冷凍サイクルでは吐出圧力の限界もあり、４５〜５０℃以上に上げることは困難である。一方蓄熱槽の大型化はすなわち機器の設置面積や製品運転質量の増大を意味するため、設置場所の面積や強度確保の観点から施工性に対しては大きなデメリットとなる恐れがあった。
【０００５】
また、寒冷地区、特に北海道地区においては冬季の電力ピークが夕方１６時から１８時の間に発生するため、電力平準化の観点から夕方に蓄熱利用運転を行ない消費電力を低減することが必要である。しかし、暖房時は早朝の空調負荷が大きい時間帯より蓄熱利用を開始する必要があり、空調運転開始時から蓄熱を使いきるまで継続して蓄熱利用運転をしていた。このため夕方に蓄熱利用による運転消費電力のピークカットを実現するためには、蓄熱量そのものを増やさなければならない。
【０００６】
さらに、寒冷地区においては暖房期間が非常に長く、機器容量を選定する極寒時のピーク負荷と、中間期の部分負荷の差が大きくなる。このため、ピーク負荷時に蓄熱利用法を適合させると、中間期には蓄熱を使いきれず、そのまま放熱ロスになっていた。
【０００７】
本発明の目的は、冬季の最低外気温度が−１０℃〜−１５℃以下に達するような寒冷地域においても、十分な暖房能力を発揮するとともに、蓄熱槽を小型化することにある。
また、本発明の目的は、限られた蓄熱容量を有効に使い、夕方においても蓄熱利用によるピークカット運転を実現することにある。
さらに、本発明の目的は、部分負荷時においても蓄熱を有効に利用することにある。
なお、本発明は、上記課題、目的の少なくともひとつを解決することにある。
【０００８】
【課題を解決するための手段】
上記課題を解決するため本発明は、圧縮機、室外熱交換器を有した室外機と、蓄熱熱交換器と、室内熱交換器を有した室内機と、を備え、暖房蓄熱運転、蓄熱利用暖房運転、蓄熱非利用暖房運転を切換える蓄熱式ヒートポンプ空気調和機において、前記蓄熱利用暖房運転で運転を開始し、空調負荷が比較的小さいと判定されたときは前記蓄熱非利用暖房運転に切換え、その後蓄熱利用暖房運転を行なうべきだと判定されたときは再び前記蓄熱利用暖房運転を行うものである。
【０００９】
これにより、例えば、暖房時最大負荷が発生する早朝始動時に蓄熱を熱源とした空調を行なうとともに、空調負荷の比較的小さい昼間は、一旦蓄熱非利用運転を行ない、夕方の空調負荷増大時まで蓄熱を利用しないで済むため、必要とされる暖房能力を確保したうえで、蓄熱量を低減することが可能となる。よって、限られた蓄熱容量を有効に使うことができるので、蓄熱槽を小型化したり、夕方においても蓄熱利用によるピークカット運転を実現したり、することができる。
【００１０】
蓄熱利用暖房運転と蓄熱非利用暖房運転の切換え判定は、具体的には、蓄熱媒体の温度により蓄熱量を検出することにより行うことが良い。
蓄熱媒体が水やその混合物の場合、暖房時は顕熱を利用して蓄熱を行なうので、蓄熱量は温度に比例する。したがって、一旦蓄熱利用運転を終了する条件を、予め再び蓄熱利用運転を始めてから後の運転に必要な蓄熱量となる蓄熱量に相当する蓄熱媒体の温度に達した時と決めておくことで、蓄熱利用運転の再開後も必要な蓄熱量が確保することができる。
【００１１】
また、空調能力または空調負荷が所定の値以下になったとき、蓄熱非利用運転に移行させることも良く、具体的な方法としては、室内機の吸込温度または吸込温度と設定温度の差により空調能力または空調負荷を演算することが望ましい。これは、直接的かつ確実な判定方法であり、これら値は絶対値のみならず、室内機が運転しているときや設定温度に達していわゆるサーモオフしたときの変化率からも、空調負荷を推定することが可能であり、判定の確度を上げることができる。
【００１２】
さらに、空調能力または空調負荷を認識するのに、圧縮機の運転周波数または運転台数によることも低価格にするうえでは良い。つまり、圧縮機の運転周波数は運転空調能力に相関しているので、これが一定値以下に達した時に蓄熱非利用運転へ移行するよう判定することが可能である。
【００１３】
さらに上記のものにおいて、時刻計時装置を備え、所定の時刻になったときに前記蓄熱非利用暖房運転から前記蓄熱利用暖房運転に移行させることが望ましい。具体的には、時刻に対する外気温度の変化は統計的な相関の情報が得られているので、負荷の増大する時刻に蓄熱利用運転を再開するよう予め決めれば、負荷の増大に対応して暖房能力や省電力効果を維持した運転を行なうことができる。
【００１４】
さらに上記のものにおいて、蓄熱熱交換器を主として蒸発器として用いる運転を行う時間帯は１６時〜１８時を含むことが望ましい。
【００１５】
さらに上記のものにおいて、空調負荷が比較的小さいと判定された前記蓄熱非利用暖房運転は、前記室外熱交換器と前記蓄熱熱交換器の熱源を併用して運転されることが望ましい。
【００１６】
さらに上記のものにおいて、蓄熱非利用暖房運転における暖房能力は、前記蓄熱利用暖房運転における暖房能力の８５％以上１００％未満の比率であることが望ましい。
【００１７】
さらに上記のものにおいて、所定の時刻において蓄熱量が所定量以上残存している場合、空調負荷が比較的小さいと判定されたときは前記蓄熱利用暖房運転を継続することが望ましい。
【００１８】
さらに上記のものにおいて、空調負荷は前記室内機の吸込温度または吸込温度と設定温度の差により演算することが望ましい。
【００１９】
さらに本発明は、液インジェクションされるようにされた圧縮機、室外熱交換器を有した室外機と、蓄熱熱交換器と、室内熱交換器を有した室内機と、を備え、暖房蓄熱運転、蓄熱利用暖房運転、蓄熱非利用暖房運転を切換える蓄熱式ヒートポンプ空気調和機において、前記液インジェクション量を制御する液インジェクション流量制御装置を備え、前記蓄熱利用暖房運転で運転を開始し、前記液インジェクション量を制御された前記蓄熱非利用暖房運転に切換えられるものである。
【００２０】
これにより、能力が低下する蓄熱非利用運転において、外気が低温であっても高い暖房能力が発揮される液インジェクション圧縮機を採用することで暖房能力の低下を小さくできるため、蓄熱利用運転をする時間を短縮して一層蓄熱槽を小型化できるうえ、蓄熱非利用運転時の能力を確保するため室外熱交換器や圧縮機の容量を大きくする必要がなく、室外機も小型化することができる。
また、暖房能力の高い液インジェクションを夜間の蓄熱運転にも利用することが望ましく、外気温度が低い場合でも確実に蓄熱量を確保することができる。
さらに蓄熱利用運転時にも液インジェクションを利用することで、蓄熱利用運転の開始当初水温が高く圧縮機吸入側の過熱度が大きくなることから吐出温度が高くなることに対しても吐出温度を低減できるので、高温部の熱損失を低減して運転効率を向上するとともに、圧縮機電動機の絶縁被覆や冷凍機油など有機材料の劣化を低減することができ、機器の信頼性を向上できる。
【００２１】
【発明の実施の形態】
本発明による第１の実施の形態について、説明する。
図１は本発明による第１の実施の形態における冷凍サイクル構成を示すブロック図を示す。容量制御圧縮機１、一定速圧縮機２ａ、２ｂ、アキュムレータ３、オイルセパレータ４、四方弁５、室外熱交換器６ａ、６ｂ、室外膨張弁７ａ、７ｂ、過冷却器８ａ、８ｂ、室外送風機９ａ、９ｂ、レシーバ１０、ガス液熱交換器１１、ガス阻止弁１２、液阻止弁１３、蓄熱ガス阻止弁１４、ガスバイパス１５、蓄熱回路用電磁弁１６ａ、１６ｂ、容量制御圧縮機用液インジェクション膨張弁２０、一定速圧縮機用液インジェクション膨張弁２１ａ、２１ｂ、容量制御圧縮機用液インジェクション電磁弁２２、一定速圧縮機用液インジェクション電磁弁２３ａ、２３ｂ、容量制御圧縮機用液インジェクションキャピラリーチューブ２４、一定速圧縮機用液インジェクションキャピラリーチューブ２５ａ、２５ｂ、室外制御装置３０、室外温度センサー３１、容量制御圧縮機用吐出温度センサー３２、一定速圧縮機用吐出温度センサー３３ａ、３３ｂ、吸入温度センサー３４、高圧圧力センサー３６、低圧圧力センサー３７からなる室外機１００と、室内熱交換器５０ａ、５０ｂ、５０ｃ、室内膨張弁５１ａ、５１ｂ、５１ｃ、室内送風機５２ａ、５２ｂ、５２ｃ、室内制御装置５３ａ、５３ｂ、５３ｃ、室内吸込温度センサー５４ａ、５４ｂ、５４ｃ、リモートコントローラー５５ａ、５５ｂ、５５ｃからなる室内機２００ａ、２００ｂ、２００ｃと、蓄熱槽６０、蓄熱熱交換器６１、蓄熱回路用膨張弁６２、蓄熱回路用電磁弁６３ａ、６３ｂ、６３ｃ、蓄熱制御装置６５、蓄熱媒体温度センサー６６、蓄熱コントローラー６７からなる蓄熱機３００とが、ガス接続配管４０、液接続配管４１、蓄熱ガス接続配管４２、伝送線４５によって連結されている。
【００２２】
なお第１の実施の形態では、容量制御圧縮機１、一定速圧縮機２ａ、２ｂには、冷媒吸入部から冷媒吐出部の圧縮過程にある中間圧部に液冷媒をインジェクションするポートを設けた、液インジェクションスクロール型圧縮機を採用する。これにより、圧縮機の吸入圧力が低下して吸入冷媒密度が低下しても、途中で液冷媒が加わるので吐出側の冷媒流量が確保される。
【００２３】
本実施の形態は、Ｒ２２、Ｒ４０７Ｃ、Ｒ４０７Ｅ、Ｒ４１０Ａ、Ｒ３２などの冷媒を作動流体に用いた蒸気圧縮冷凍サイクルを利用しており、夜間に蓄熱熱交換器６１内の蓄熱媒体に蓄熱運転を行ない、昼間の空調運転時にこの蓄熱を利用する運転を行なう。蓄熱コントローラー６７は予め夜間の蓄熱運転の時間帯がセットされ、この時間帯に蓄熱運転を指令し、またそれ以外に空調運転可能であることを指令する。空調運転可能なとき、室内機２００ａ、２００ｂ、２００ｃのリモートコントローラー５５ａ、５５ｂ、５５ｃいずれかがオンされて、空調運転を開始する。リモートコントローラー５５ａ、５５ｂ、５５ｃは冷房、暖房の切換えや風量などを設定する。これらの司令によって、室外制御装置３０、室内制御装置５３ａ、５３ｂ、５３ｃ、蓄熱制御装置６５らは、四方弁５、蓄熱回路用電磁弁１６ａ、１６ｂ、蓄熱回路用電磁弁６３ａ、６３ｂ、６３ｃを切り換え、冷房蓄熱運転、冷房蓄熱利用ピークシフト運転、冷房蓄熱利用ピークカット運転、冷房蓄熱非利用運転、暖房蓄熱運転、暖房蓄熱利用運転、暖房蓄熱非利用運転、蓄熱利用除霜運転、蓄熱非利用除霜運転の各運転モードの切り換えを行なう。また、容量制御圧縮機１、一定速圧縮機２ａ、２ｂ、室外送風機９ａ、９ｂ、室内送風機５２ａ、５２ｂ、５２ｃを動作させ、運転を行なう。
【００２４】
さらに運転中は室外膨張弁７ａ、７ｂ、容量制御圧縮機用液インジェクション膨張弁２０、一定速圧縮機用液インジェクション膨張弁２１ａ、２１ｂ、室内膨張弁５１ａ、５１ｂ、５１ｃ、蓄熱回路用膨張弁６２の開度、容量制御圧縮機１の運転容量、一定速圧縮機２ａ、２ｂの運転台数などを適当な運転となるよう制御を行なう。
【００２５】
次に、冷房蓄熱運転時の冷媒の流れを示す。
容量制御圧縮機１、一定速圧縮機２ａ、２ｂを吐出した高圧高温のガス冷媒は四方弁５を経由し室外熱交換器６ａ、６ｂにて凝縮し、過冷却器８ａ、８ｂで過冷却液となりレシーバ１０、ガス液熱交換器１１、液阻止弁１３、液接続配管４１を経由して、蓄熱機３００に達する。ここで蓄熱回路用電磁弁６３ａ、６３ｃは開弁しており、蓄熱回路用膨張弁６２にて絞られた液冷媒が蓄熱熱交換器６１にて蒸発し、水温を低下させ０℃以下にして製氷することで潜熱として蓄熱を行なう。蒸発後のガス冷媒は蓄熱回路用電磁弁６３ａ、蓄熱ガス接続配管４２、蓄熱回路用電磁弁１６ｂ、ガス液熱交換器１１、アキュムレータ３を介して圧縮機低圧側へ戻る。
【００２６】
次に、冷房蓄熱利用ピークシフト運転時の冷媒の流れを示す。
容量制御圧縮機１、一定速圧縮機２ａ、２ｂを吐出した高圧高温のガス冷媒は四方弁５を経由し室外熱交換器６ａ、６ｂにて凝縮し、過冷却器８ａ、８ｂ、レシーバ１０、ガス液熱交換器１１、液阻止弁１３、液接続配管４１を経由して、蓄熱機３００に達する。ここで蓄熱回路用電磁弁６３ｂの開弁により、液冷媒は蓄熱熱交換器６１に導かれ、氷と熱交換を行なう。こうして過冷却され比エンタルピの低くなった液冷媒が室内機２００ａ、２００ｂ、２００ｃに搬送され、室内膨張弁５１ａ、５１ｂ、５１ｃで絞られて室内熱交換器５０ａ、５０ｂ、５０ｃにて蒸発し空気と熱交換することで、冷房を行なう。蒸発したガス冷媒はガス接続配管４０より室外機１００へ戻され、四方弁５、ガス液熱交換器１１、アキュムレータ３を介して圧縮機低圧側へ戻る。
【００２７】
なお、氷と熱交換することで蓄熱熱交換器６１にて大きく比エンタルピを低下させるので、室内熱交換器５０ａ、５０ｂ、５０ｃ入口と出口の比エンタルピ差が大きいため冷媒循環量を少なくすることができるので、圧縮機運転容量を低減して消費電力を小さくすることができる。
【００２８】
次に、冷房蓄熱利用ピークカット運転時の冷媒の流れを示す。
容量制御圧縮機１、一定速圧縮機２ａ、２ｂを吐出した高圧高温のガス冷媒は、蓄熱回路用電磁弁１６ｂより蓄熱ガス接続配管４２を経由して、蓄熱機３００に達する。ここで蓄熱回路用電磁弁６３ａの開弁により、高圧高温ガス冷媒は蓄熱熱交換器６１に導かれて氷と熱交換を行なう。こうして凝縮、過冷却され、比エンタルピの低くなった液冷媒が室内機２００ａ、２００ｂ、２００ｃに搬送され、室内膨張弁５１ａ、５１ｂ、５１ｃで絞られて室内熱交換器５０ａ、５０ｂ、５０ｃにて蒸発し空気と熱交換することで、冷房を行なう。蒸発したガス冷媒は、冷房蓄熱利用ピークシフト運転同様、圧縮機低圧側へ戻る。
【００２９】
高圧高温のガス冷媒が氷と熱交換することで凝縮圧力を著しく低下させることができるため、過冷却による比エンタルピの低下とあいまって、圧縮機運転消費電力が大きく削減される。省電力効果の大きい冷房蓄熱利用ピークカット運転を冷房時の電力ピークが出現する１３時〜１６時に行なうことにより、電力の平準化に貢献するとともに、契約電力も小さくすることが可能となる。
【００３０】
次に蓄熱を使い切った後の、冷房蓄熱非利用運転時の冷媒の流れを示す。
容量制御圧縮機１、一定速圧縮機２ａ、２ｂを吐出した高圧高温のガス冷媒は四方弁５を経由し室外熱交換器６ａ、６ｂにて凝縮し、過冷却器８ａ、８ｂで過冷却液となりレシーバ１０、ガス液熱交換器１１、液阻止弁１３、液接続配管４１を経由して、室内機２００ａ、２００ｂ、２００ｃに搬送される。このとき蓄熱回路用電磁弁６３ｃが開弁状態にある。室内膨張弁５１ａ、５１ｂ、５１ｃで絞られて室内熱交換器５０ａ、５０ｂ、５０ｃにて蒸発し空気と熱交換することで冷房を行ない、蒸発したガス冷媒は他の冷房運転同様、圧縮機低圧側へ戻る。
【００３１】
次に、暖房蓄熱運転時の冷媒の流れを示す。
容量制御圧縮機１、一定速圧縮機２ａ、２ｂを吐出した高圧高温のガス冷媒は、蓄熱回路用電磁弁１６ｂより蓄熱ガス接続配管４２を経由して、蓄熱機３００に達する。ここで蓄熱回路用電磁弁６３ａの開弁により、高圧高温ガス冷媒は蓄熱熱交換器６１に導かれて水と熱交換を行ない、水温を上昇させる。凝縮した液冷媒は蓄熱回路用膨張弁６２、開弁状態の蓄熱回路用電磁弁６３ｃ、液接続配管４１を経由して室外機１００に戻り、ガス液熱交換器１１、レシーバ１０、過冷却器８ａ、８ｂの後、室外膨張弁７ａ、７ｂで膨張して室外熱交換器６ａ、６ｂで蒸発する。蒸発したガス冷媒は、四方弁５、ガス液熱交換器１１、アキュムレータ３を介して圧縮機低圧側へ戻る。
【００３２】
外気温度が低く蒸発圧力が低下する条件では、室外膨張弁７ｂ前の過冷却液冷媒を分岐して、容量制御圧縮機１、一定速圧縮機２ａ、２ｂ各々に対して、容量制御圧縮機用液インジェクション膨張弁２０、一定速圧縮機用液インジェクション膨張弁２１ａ、２１ｂ、容量制御圧縮機用液インジェクション電磁弁２２、一定速圧縮機用液インジェクション電磁弁２３ａ、２３ｂ、容量制御圧縮機用液インジェクションキャピラリーチューブ２４、一定速圧縮機用液インジェクションキャピラリーチューブ２５ａ、２５ｂを介して接続し、液インジェクションを行なう。このとき、室外膨張弁７ａ、７ｂは、吸入温度センサー３４、低圧圧力センサー３７より演算される過熱度が目標値となるように制御される。また、一定速圧縮機用液インジェクション電磁弁２３ａ、２３ｂは運転している圧縮機のみ開弁するとともに、容量制御圧縮機用液インジェクション膨張弁２０、一定速圧縮機用液インジェクション膨張弁２１ａ、２１ｂの開度を制御して、圧縮機の吐出温度が適正になるように液インジェクション量をコントロールする。
【００３３】
以上のように液インジェクション圧縮機を採用したので、外気温度が低く圧縮機の吸入冷媒密度が低下して冷媒循環量が減少するような条件でも吐出側の冷媒流量が確保されるので、高い暖房能力を維持することができ、水温を上昇させて蓄熱量を確保することができる。
【００３４】
次に、暖房蓄熱利用運転時の冷媒の流れを示す。
容量制御圧縮機１、一定速圧縮機２ａ、２ｂを吐出した高圧高温のガス冷媒は四方弁５を経由し、ガス接続配管４０より室内機２００ａ、２００ｂ、２００ｃに搬送され、室内熱交換器５０ａ、５０ｂ、５０ｃにて凝縮放熱して暖房を行なう。凝縮液冷媒はこの後蓄熱機３００にて蓄熱回路用膨張弁６２により絞られて、蓄熱熱交換器６１にてお湯と熱交換して蒸発する。このとき蓄熱回路用電磁弁６３ａが開弁されており、ガス冷媒は蓄熱ガス接続配管４２より室外機１００へ戻り、蓄熱回路用電磁弁１６ｂ、ガス液熱交換器１１、アキュムレータ３を介して圧縮機低圧側へ戻る。この時、室外膨張弁７ａ、７ｂは全閉として全く室外熱交換器６ａ、６ｂを使用せず、室外送風機９ａ、９ｂも停止する。
【００３５】
本運転では、蓄熱熱交換器６１よりお湯を熱源として利用するので、外気温度が低くても冷媒の蒸発のために大きな熱量が得られるので、蒸発圧力が高くなり圧縮機吸入ガス冷媒の密度が高くなるので、冷媒循環量が増大して非常に高い能力が得られるとともに、温風の立上りも早い。また、室外熱交換器６ａ、６ｂを使用しないので、着霜することが無く除霜運転を行なう必要が無い。さらに室外送風機９ａ、９ｂも停止するので、消費電力が低減される。ここで、暖房能力を抑えて容量制御圧縮機１の運転容量、一定速圧縮機２ａ、２ｂの運転台数を調整して暖房非利用運転時よりも少ない圧縮機運転容量で運転することで、暖房能力増大分を運転消費電力の低減に当てることができ、高い暖房能力を発揮しながら省電力効果をも得ることができる。
【００３６】
暖房蓄熱利用運転においても、運転を開始してしばらくの間水温が高い時は、蒸発ガス冷媒が過熱されるため圧縮機吸入部の過熱度も大きくなり、吐出温度が上昇してしまう。そこで、ここでも暖房蓄熱運転同様液インジェクションを使用して、各圧縮機の吐出温度が適正となるように液インジェクション量を制御することで、高温部の熱損失を低減して運転効率を向上するとともに、圧縮機電動機の絶縁被覆や冷凍機油など有機材料の劣化を低減することができ、機器の信頼性を向上できる。
【００３７】
次に、暖房蓄熱非利用運転時の冷媒の流れを示す。
室内熱交換器５０ａ、５０ｂ、５０ｃにて凝縮放熱して暖房を行なうまでは、暖房蓄熱利用運転と同じであるが、本運転時は蓄熱回路用電磁弁６３ｃ開弁により液冷媒を室外機１００に戻し、あとは暖房蓄熱運転時と同様に室外熱交換器６ａ、６ｂにて蒸発させ圧縮機低圧側へ戻す。
【００３８】
暖房蓄熱運転時と同様に外気温度が低く蒸発圧力が低下する条件では、容量制御圧縮機用液インジェクション膨張弁２０、一定速圧縮機用液インジェクション膨張弁２１ａ、２１ｂにより液インジェクションを行ない、圧縮機の吐出温度が適正になるように液インジェクション量をコントロールする。
これにより、暖房蓄熱運転と同様、外気温度が低く圧縮機の吸入冷媒密度が低下して冷媒循環量が減少するような条件でも、高い暖房能力を維持することができる。蓄熱利用除霜運転時の冷媒の流れは冷房蓄熱運転と同じであり、蓄熱非利用除霜運転時の冷媒の流れは冷房非利用運転時と同じになる。
【００３９】
次に、本実施の形態の暖房運転時の運転モードの切り換え方法を、図２にしたがって説明する。
図２は、本発明の第１の実施の形態における暖房運転の状態を示しており、一日の運転における暖房能力と消費電力と蓄熱量を代表して示す水温の変化、および運転モードの切り変わりの様子を示している。夜間の蓄熱運転について説明する。タイマーより予め設定された時刻（本例では２２時）になると、暖房蓄熱運転を開始する。これにより徐々に蓄熱槽内の水温が上昇していき、これが所定の値に達した時に暖房蓄熱運転を終了する。
【００４０】
次に昼間の空調運転について説明する。早朝の運転開始時は外気温度も低く空調負荷が大きいので、図中の能力を示すグラフのように大きな能力が必要である。本実施の形態ではまず暖房蓄熱利用運転モードにて運転を開始する。これにより、前述のとおり、高い暖房能力を発揮しながら省電力効果を得ることができ、点線が示す蓄熱非利用の場合の消費電力よりも低い消費電力で運転することができる。暖房蓄熱利用運転を継続していくと、蓄熱を熱源として利用した結果水温が低下していく。これが所定の温度（図中の蓄熱利用運転一旦非利用移行温度）に達したとき、一旦運転モードを暖房蓄熱非利用運転に移行する。早朝のピーク負荷に比べ日中は気温も上昇して空調負荷が減るので、空調能力が低い暖房蓄熱非利用運転になっても空調能力を適合範囲とすることができる。
【００４１】
なお本実施の形態においては、暖房蓄熱非利用運転であっても、液インジェクション利用の効果により、低外気温時の暖房能力は高い。この暖房蓄熱非利用運転時の暖房能力は、暖房蓄熱利用運転時の概ね８５％以上とすることで、移行時の暖房能力較差を発生させることが無く、快適性を維持した運転をすることができる。本比率に蓄熱利用運転時と蓄熱非利用運転時の能力の比率を設定することで、ピーク負荷時の空調時間帯の蓄熱利用運転時間を空調時間の約５０％程度とすることができ、蓄熱槽の小型化と快適性の観点から適切な比率とすることができる。
【００４２】
暖房非利用運転を継続して、夕方徐々に外気温度が低下して暖房負荷が増大してきたとき、本実施の形態では再び暖房蓄熱利用運転モードへ移行して、暖房能力の高い運転を行なう。このタイミングについては、本実施の形態では予め設定されている時刻になったときに運転モードの切り換えを行なう。
【００４３】
北海道地方では冬季の電力ピークが夕方の１６時から１８時の間に発生しており、本実施の形態ではこの時間帯を含むように、暖房蓄熱利用運転を１６時より開始するので、電力ピーク発生時間帯に消費電力の低い運転を行なうため、ピーク消費電力の低減に貢献する。暖房利用運転に再移行後は、蓄熱利用温度の下限である蓄熱利用運転終了温度に達した時点で、再度蓄熱非利用運転に切り変わる。以上のように、外気温度が低くても、暖房空調負荷が比較的小さくなる日中に暖房能力が負荷の低下に見合う程度に能力が維持可能な、液インジェクション圧縮機を適用した蓄熱を利用しない運転を行なうことで、蓄熱を利用する運転を朝夕に分割することができるため、空調全時間に暖房蓄熱利用運転を行なう場合よりも蓄熱容量が少なくて済み、機器の設置面積の小型化、運転質量の軽量化を図ることができる。また、１６時〜１８時の電力ピーク発生時間帯に消費電力の低い運転を行なうため、ピーク消費電力の低減に効果的であり、電力平準化を促進するのに有効である。
【００４４】
次に、本発明の第２の実施の形態について説明する。
図３は本発明による第２の実施の形態における冷凍サイクル構成を示すブロック図を示している。符号については、前記本発明の第１の実施の形態と同様である。ただし容量制御圧縮機１、一定速圧縮機２ａ、２ｂは、液インジェクションタイプでない、通常のスクロール型圧縮機を採用する。そのため液インジェクションに関する冷媒回路を有していないのが、第１の実施の形態と異なる。。
【００４５】
次に、本発明の第２の実施の形態の動作を説明する。
本実施の形態は基本的には本発明の第１の実施の形態において、液インジェクションのみ無くした場合と同じであるので、それらと異なる運転モードとなる暖房蓄熱併用運転についてのみ説明する。
【００４６】
以下に暖房蓄熱併用運転の冷媒の流れを示す。
容量制御圧縮機１、一定速圧縮機２ａ、２ｂを吐出した高圧高温のガス冷媒は四方弁５を経由し、ガス接続配管４０より室内機２００ａ、２００ｂ、２００ｃに搬送され、室内熱交換器５０ａ、５０ｂ、５０ｃにて凝縮放熱して暖房を行なう。凝縮液冷媒はこの後、以下の２つに別れて流れる。
【００４７】
一方は、蓄熱機３００にて蓄熱回路用膨張弁６２により絞られて、蓄熱熱交換器６１にてお湯と熱交換して蒸発し、蓄熱回路用電磁弁６３ａから蓄熱ガス接続配管４２より室外機１００へ戻り、蓄熱回路用電磁弁１６ｂ、ガス液熱交換器１１、アキュムレータ３を介して圧縮機低圧側へ戻るものである。
【００４８】
他方は、蓄熱回路用電磁弁６３ｃを経由して室外機１００に戻り、ガス液熱交換器１１、レシーバ１０、過冷却器８ａ、８ｂの後、室外膨張弁７ａ、７ｂで膨張して室外熱交換器６ａ、６ｂで蒸発する。蒸発したガス冷媒は、四方弁５、ガス液熱交換器１１、アキュムレータ３を介して圧縮機低圧側へ戻る。
【００４９】
以上のように冷媒が流れるので、液冷媒の蒸発熱源としては蓄熱および空気の双方から吸熱していることになる。これにより、全く蓄熱を熱源として利用しなかった場合、すなわち第１の実施の形態における暖房蓄熱非利用運転の場合と比較して、外気の影響を受けにくくなり比較的高い暖房能力を得ることができる。
【００５０】
次に、本実施の形態の暖房運転時の運転モードの切り換え方法を、図４にしたがって説明する。
図４は、第２の実施の形態における暖房運転の状態を示しており、第１の実施の形態の運転状態を示す図２との差異は、一旦暖房蓄熱利用運転を昼間に移行するときに、暖房蓄熱併用運転を行なっている点である。暖房蓄熱併用運転は、熱源として蓄熱と空気熱交の両方を使用するため、低外気温時でも比較的暖房能力は高い。これにより、第１の実施の形態同様、外気温度が低くても、暖房空調負荷が比較的小さくなる日中に暖房能力が負荷の低下に見合う程度に能力が維持可能な、蓄熱熱源を空気熱源と併用利用する運転を行なうことで、蓄熱を専用に利用する運転を朝夕に分割することができるため、空調全時間に暖房蓄熱利用運転を行なう場合よりも蓄熱容量が少なくて済み、機器の設置面積の小型化、運転質量の軽量化を図ることができる。但し蓄熱容量については蓄熱併用運転があるため、第１の実施の形態よりは多少大きくすることが良い。一方、液インジェクション圧縮機や液インジェクション冷媒回路は不要となり、部品点数を少なくできる。
【００５１】
次に、本発明の第３の実施の形態を示す。
図５は、第３の実施の形態における暖房運転の状態を示しており、第１の実施の形態および第２の実施の形態のように、暖房蓄熱利用運転から一旦暖房蓄熱非利用運転あるいは暖房蓄熱併用運転に切り換わるものにおいて、図中能力が高負荷時（細線）に対し低負荷時に対応なった場合の動作を示している。
【００５２】
負荷が小さく暖房能力に余裕がある場合、蓄熱利用量が減ってしまうため、空調運転終了時点で蓄熱を使い切らずに余ってしまう可能性がる。本実施の形態では、図５に示すとおり、所定の時間を超えて水温が高かった場合、暖房蓄熱利用運転を切りかえる制御を行なわず、そのまま蓄熱利用を終了まで続けるものである。
【００５３】
これにより、中間期など負荷が小さいとき、途中で非利用運転を行なわないので、蓄熱利用率が低くて蓄熱を残してしまうことが無くなり、熱ロスによる無駄な電力の消費を少なくすることができる。
【００５４】
次に、本発明の第４および第５の実施の形態を示す。
図６は、第４の実施の形態における暖房運転の状態を示しており、図７は第５の実施の形態における暖房運転の状態を示している。本実施の形態は、本発明の第１の実施の形態における図２と同じく、暖房蓄熱利用運転から一旦暖房蓄熱利用運転を止め、再度暖房蓄熱利用運転に切り換わる場合の判定方法を示している。双方とも暖房能力が低い時に暖房蓄熱利用運転を行なうようになっており、図６は例えばリモートコントローラにて設定される室内設定温度と吸込み温度の差により必要能力を演算した結果として扱い、これが図中に示す蓄熱利用一旦移行能力以下になったときに暖房蓄熱非利用運転に移行し、また夕方空調負荷が増え図中蓄熱利用運転再開能力を超えたとき、暖房蓄熱利用運転に切換える。
【００５５】
一方、図７は暖房能力を圧縮機運転容量で判断するもので、圧縮機運転周波数の合計が、図中の蓄熱非利用運転上限周波数を超えた場合は暖房蓄熱利用運転を行ない、それ以下の場合は暖房蓄熱非利用運転を行なう。暖房能力すなわち負荷を示す数値により切換えるので、より確実に暖房能力が必要な時に暖房蓄熱利用運転を行なうことができる。
【００５６】
以上の実施の形態によれば、蓄熱を利用する運転を朝夕に分割することができるため、空調全時間に暖房蓄熱利用運転を行なう場合よりも蓄熱容量が少なくて済み、機器の設置面積の小型化、運転質量の軽量化を図ることができる。
【００５７】
また、暖房運転において早朝など暖房負荷が高い早朝に高暖房能力を発揮するとともに、夕方の電力ピークが発生する時間帯に消費電力を低減した運転が可能なので、電力の平準化に貢献することができる。
【００５８】
さらに、中間期など負荷が小さいときに途中で蓄熱非利用運転を行なわないので、蓄熱利用率が低くて蓄熱を残してしまうことが無くなり、熱ロスによる無駄な電力の消費を少なくすることができる。
【００５９】
さらに、暖房負荷が小さく蓄熱消費量が少ない場合を検知して、蓄熱非利用運転を行なうことなく蓄熱利用運転を続けるので、空調運転が終了しても蓄熱が残存していることが無くなるので、蓄熱槽周囲への放熱による熱ロスを少なくすることができ、運転効率が向上される。
【００６０】
【発明の効果】
以上述べたように本発明によれば、寒冷地域においても、十分な暖房能力を発揮するとともに、蓄熱容量が少なくて済み、機器の設置面積の小型化、運転質量の軽量化を図ることができる。
【図面の簡単な説明】
【図１】本発明の一実施の形態における冷凍サイクル構成を示すブロック図。
【図２】本発明の一実施の形態における暖房運転の状態を示すグラフ。
【図３】本発明の他の実施の形態における冷凍サイクル構成を示すブロック図。
【図４】本発明の他の実施の形態における暖房運転の状態を示すグラフ。
【図５】本発明のさらに他の実施の形態における暖房運転の状態を示す
【図６】本発明のさらに他の実施の形態における暖房運転の状態を示すグラフ。
【図７】本発明のさらに他の実施の形態における暖房運転の状態を示すグラフ。
【符号の説明】
１…容量制御圧縮機、２ａ、２ｂ…一定速圧縮機、３…アキュムレータ、４…オイルセパレータ、５…四方弁、６ａ、６ｂ…室外熱交換器、７ａ、７ｂ…室外膨張弁、８ａ、８ｂ…過冷却器、９ａ、９ｂ…室外送風機、１０…レシーバ、１１…ガス液熱交換器、１２…ガス阻止弁、１３…液阻止弁、１４…蓄熱ガス阻止弁、１５…ガスバイパス、１６ａ、１６ｂ…蓄熱回路用電磁弁、２０…容量制御圧縮機用液インジェクション膨張弁、２１ａ、２１ｂ…一定速圧縮機用液インジェクション膨張弁、２２…容量制御圧縮機用液インジェクション電磁弁、２３ａ、２３ｂ…一定速圧縮機用液インジェクション電磁弁、２４…容量制御圧縮機用液インジェクションキャピラリーチューブ、２５ａ、２５ｂ…一定速圧縮機用液インジェクションキャピラリーチューブ、３０…室外制御装置、３１…室外温度センサー、３２…容量制御圧縮機用吐出温度センサー、３３ａ、３３ｂ…一定速圧縮機用吐出温度センサー、３４…吸入温度センサー、３６…高圧圧力センサー、３７…低圧圧力センサー、４０…ガス接続配管、４１…液接続配管、４２…蓄熱ガス接続配管、４５…伝送線、５０ａ、５０ｂ、５０ｃ…室内熱交換器、５１ａ、５１ｂ、５１ｃ…室内膨張弁、５２ａ、５２ｂ、５２ｃ…室内送風機、５３ａ、５３ｂ、５３ｃ…室内制御装置、５４ａ、５４ｂ、５４ｃ…室内吸込温度センサー、５５ａ、５５ｂ、５５ｃ…リモートコントローラー、６０…蓄熱槽、６１…蓄熱熱交換器、６２…蓄熱回路用膨張弁、６３ａ、６３ｂ…蓄熱回路用電磁弁、６５…蓄熱制御装置、６６…蓄熱媒体温度センサー、蓄熱コントローラー６７、１００…室外機、２００ａ、２００ｂ、２００ｃ…室内機、３００…蓄熱機。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a regenerative heat pump air conditioner that performs an air conditioning operation utilizing heat storage using a vapor compression refrigeration cycle, and is particularly used in a cold region where the outdoor air temperature drops to, for example, −15 ° C. or less in winter. It is suitable for regenerative heat pump type air conditioners.
[0002]
[Prior art]
It is known that the capacity is stabilized by control of alternately or simultaneously operating the cold storage operation and the cooling operation and the heat storage operation and the heating operation, which is described in, for example, Japanese Patent Application Laid-Open No. 9-138025.
[0003]
[Problems to be solved by the invention]
In the above prior art, no consideration is given to a cold region in which the minimum outside air temperature in winter reaches −10 ° C. to −15 ° C. or less.In a cold region, an air heat source type heat pump that does not use heat storage is sufficient. Since a suitable heat source cannot be obtained, the decrease in performance is large. On the other hand, when the heat storage is used as a heat source, the heat source is ensured regardless of the outside air temperature, and therefore, it is extremely effective in maintaining the heating capacity at a low outside air temperature and reducing power consumption even in a cold region.
[0004]
However, an ice storage air conditioner using water as a heat storage medium generally uses sensible heat as a heat source in a heating operation, and therefore has a smaller heat storage amount than a cooling operation using latent heat. Although it is possible to use latent heat even in the heating operation, it is not an effective method because the performance is remarkably reduced due to a decrease in heat transfer performance due to formation of ice on the heat transfer tube surface. Therefore, in order to obtain sufficient performance for a long time even in cold regions, it is necessary to increase the amount of heat storage, and increase the size of the heat storage tank to increase the amount of heat storage medium, or increase the temperature of the heat storage end water to increase the use temperature. There is a need to. With respect to the heat storage end water temperature, there is a limit of the discharge pressure in the heat pump refrigeration cycle, and it is difficult to increase the temperature to 45 to 50 ° C or more. On the other hand, an increase in the size of the heat storage tank means an increase in the installation area of the equipment and an increase in the operating mass of the product.
[0005]
Further, in a cold district, particularly in a Hokkaido district, a power peak in winter occurs between 16:00 and 18:00 in the evening, so that it is necessary to reduce the power consumption by performing the heat storage operation in the evening from the viewpoint of power leveling. However, at the time of heating, it is necessary to start using heat storage from the time period when the air conditioning load is large in the early morning, and the heat storage use operation has been continuously performed from the start of the air conditioning operation until the heat storage is used up. Therefore, in order to achieve a peak cut in operating power consumption by utilizing heat storage in the evening, the amount of heat storage must be increased.
[0006]
Further, in a cold district, the heating period is very long, and the difference between the peak load at the time of extreme cold when selecting the equipment capacity and the partial load in the middle period increases. For this reason, if the heat storage utilization method was adapted at the peak load, the heat storage could not be used up in the interim period, resulting in a radiation loss as it was.
[0007]
An object of the present invention is to provide a sufficient heating capacity and reduce the size of a heat storage tank even in a cold region where the minimum outside temperature in winter reaches −10 ° C. to −15 ° C. or less.
It is another object of the present invention to effectively use a limited heat storage capacity and realize a peak cut operation by utilizing heat storage even in the evening.
Further, an object of the present invention is to effectively utilize heat storage even under a partial load.
The present invention is to solve at least one of the above problems and objects.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention includes a compressor, an outdoor unit having an outdoor heat exchanger, a heat storage heat exchanger, and an indoor unit having an indoor heat exchanger. In the heat storage heat pump air conditioner that switches between the heating operation and the heat storage non-use heating operation, the operation is started in the heat storage use heating operation, and when it is determined that the air conditioning load is relatively small, the operation is switched to the heat storage non-use heating operation. Thereafter, when it is determined that the heat storage use heating operation should be performed, the heat storage use heating operation is performed again.
[0009]
Thus, for example, air conditioning using heat storage as a heat source is performed at the start of early morning when the maximum load at the time of heating occurs, and during the daytime when the air conditioning load is relatively small, the heat storage non-use operation is performed once, and the heat storage is performed until the air conditioning load increases in the evening. Therefore, it is possible to reduce the amount of heat storage while securing the required heating capacity. Therefore, since the limited heat storage capacity can be used effectively, the size of the heat storage tank can be reduced, and a peak cut operation using heat storage can be realized even in the evening.
[0010]
The switching determination between the heat storage use heating operation and the heat storage non-use heating operation may be specifically performed by detecting the amount of heat storage based on the temperature of the heat storage medium.
When the heat storage medium is water or a mixture thereof, heat is stored using sensible heat during heating, so that the amount of heat storage is proportional to the temperature. Therefore, by deciding the condition for once terminating the heat storage operation, when the temperature of the heat storage medium corresponding to the heat storage amount corresponding to the heat storage amount necessary for the subsequent operation has been started again after starting the heat storage operation again, The required heat storage amount can be secured even after the restart of the heat storage operation.
[0011]
When the air-conditioning capacity or the air-conditioning load becomes equal to or less than a predetermined value, the operation may be shifted to the non-heat storage operation. As a specific method, the air-conditioning is performed based on the suction temperature of the indoor unit or the difference between the suction temperature and the set temperature. It is desirable to calculate the capacity or the air conditioning load. This is a direct and reliable determination method, and the air conditioning load is estimated not only from the absolute value but also from the rate of change when the indoor unit is operating or when the so-called thermo-off is reached when the set temperature is reached. It is possible to increase the accuracy of the determination.
[0012]
Furthermore, in order to recognize the air-conditioning capacity or the air-conditioning load, the operation frequency or the number of operating compressors may be used to reduce the cost. That is, since the operating frequency of the compressor is correlated with the operating air conditioning capacity, it is possible to determine to shift to the heat storage non-use operation when the operating frequency reaches a certain value or less.
[0013]
Furthermore, in the above, it is preferable that a time keeping device is provided, and when a predetermined time has come, it is desirable to shift from the heat storage non-use heating operation to the heat storage use heating operation. Specifically, since a change in the outside air temperature with respect to the time has obtained statistical correlation information, if it is determined in advance to restart the heat storage utilization operation at a time when the load increases, heating in response to the increase in the load can be performed. It is possible to perform the operation while maintaining the capacity and the power saving effect.
[0014]
Further, in the above, it is preferable that the time zone in which the operation using the heat storage heat exchanger as an evaporator is mainly performed from 16:00 to 18:00.
[0015]
Furthermore, in the above, it is preferable that the heat storage non-use heating operation in which the air conditioning load is determined to be relatively small is operated using both the outdoor heat exchanger and the heat source of the heat storage heat exchanger.
[0016]
Further, in the above, it is desirable that the heating capacity in the heat storage non-use heating operation is a ratio of 85% or more and less than 100% of the heating capacity in the heat storage use heating operation.
[0017]
Furthermore, in the above, when the heat storage amount remains at a predetermined amount or more at a predetermined time, it is desirable to continue the heat storage heating operation when it is determined that the air conditioning load is relatively small.
[0018]
Further, in the above, it is preferable that the air conditioning load is calculated based on a suction temperature of the indoor unit or a difference between the suction temperature and a set temperature.
[0019]
Furthermore, the present invention includes a compressor adapted to be injected with a liquid, an outdoor unit having an outdoor heat exchanger, a heat storage heat exchanger, and an indoor unit having an indoor heat exchanger. A heat-storage type heat pump air conditioner that switches between a heat storage use heating operation and a heat storage non-use heating operation, including a liquid injection flow control device that controls the liquid injection amount, and starts operation in the heat storage use heating operation; The heating operation is switched to the heat storage-free heating operation in which the amount is controlled.
[0020]
Thereby, in the heat storage non-use operation in which the capacity is reduced, the decrease in the heating capacity can be reduced by adopting the liquid injection compressor that exhibits the high heating capacity even when the outside air is at a low temperature, so that the heat storage operation is performed. The heat storage tank can be further reduced in size by shortening the time, and the capacity of the outdoor heat exchanger and the compressor does not need to be increased in order to secure the capacity at the time of operation not using heat storage, and the outdoor unit can also be reduced in size. .
Further, it is desirable to use the liquid injection having a high heating capacity also in the nighttime heat storage operation, and it is possible to reliably secure the heat storage amount even when the outside air temperature is low.
Further, by using the liquid injection also during the heat storage operation, the discharge temperature can be reduced even when the discharge temperature increases because the water temperature is high at the beginning of the heat storage operation and the degree of superheat on the compressor suction side increases. Therefore, the operating efficiency can be improved by reducing the heat loss in the high-temperature portion, and the deterioration of the organic material such as the insulating coating of the compressor motor and the refrigerating machine oil can be reduced, and the reliability of the device can be improved.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
A first embodiment according to the present invention will be described.
FIG. 1 is a block diagram showing a configuration of a refrigeration cycle according to a first embodiment of the present invention. Capacity control compressor 1, constant speed compressors 2a, 2b, accumulator 3, oil separator 4, four-way valve 5, outdoor heat exchangers 6a, 6b, outdoor expansion valves 7a, 7b, supercoolers 8a, 8b, outdoor blower 9a , 9b, receiver 10, gas-liquid heat exchanger 11, gas check valve 12, liquid check valve 13, heat storage gas check valve 14, gas bypass 15, solenoid valves 16a, 16b for heat storage circuit, liquid injection expansion for displacement control compressor. Valve 20, liquid injection expansion valves 21a and 21b for constant speed compressor, liquid injection solenoid valve 22 for capacity control compressor, liquid injection solenoid valves 23a and 23b for constant speed compressor, liquid injection capillary tube 24 for capacity control compressor , Constant speed compressor liquid injection capillary tubes 25a, 25b, outdoor controller 30, outdoor temperature An outdoor unit 100 comprising a heat sensor 31, a discharge temperature sensor 32 for a displacement control compressor, discharge temperature sensors 33a and 33b for a constant speed compressor, a suction temperature sensor 34, a high pressure sensor 36 and a low pressure sensor 37, and an indoor heat exchanger. 50a, 50b, 50c, indoor expansion valves 51a, 51b, 51c, indoor blowers 52a, 52b, 52c, indoor control devices 53a, 53b, 53c, indoor suction temperature sensors 54a, 54b, 54c, and remote controllers 55a, 55b, 55c Indoor units 200a, 200b, 200c, a heat storage tank 60, a heat storage heat exchanger 61, a heat storage circuit expansion valve 62, a heat storage circuit solenoid valves 63a, 63b, 63c, a heat storage control device 65, a heat storage medium temperature sensor 66, and heat storage. The heat storage device 300 including the controller 67 is connected to the gas connection pipe 40, Pipe 41, the heat storage gas connection pipe 42 are connected by the transmission line 45.
[0022]
In the first embodiment, the displacement control compressor 1 and the constant speed compressors 2a and 2b are provided with ports for injecting the liquid refrigerant from the refrigerant suction part to the intermediate pressure part in the process of compressing the refrigerant discharge part. Adopt a liquid injection scroll type compressor. Thus, even if the suction pressure of the compressor decreases and the suction refrigerant density decreases, the liquid refrigerant is added on the way, so that the flow rate of the refrigerant on the discharge side is ensured.
[0023]
The present embodiment utilizes a vapor compression refrigeration cycle using a refrigerant such as R22, R407C, R407E, R410A, R32 as a working fluid, and performs a heat storage operation on a heat storage medium in a heat storage heat exchanger 61 at night. During the daytime air conditioning operation, an operation utilizing this heat storage is performed. The heat storage controller 67 is preset with a time zone of the nighttime heat storage operation, and instructs the heat storage operation in this time zone, and also instructs that the air conditioning operation is possible. When the air conditioning operation is possible, one of the remote controllers 55a, 55b, 55c of the indoor units 200a, 200b, 200c is turned on, and the air conditioning operation is started. The remote controllers 55a, 55b, and 55c set switching between cooling and heating, and set the air volume and the like. By these commands, the outdoor control device 30, the indoor control devices 53a, 53b, 53c, and the heat storage control device 65, etc., control the four-way valve 5, the heat storage circuit solenoid valves 16a, 16b, and the heat storage circuit solenoid valves 63a, 63b, 63c. Switching, cooling / heat storage operation, cooling / heat storage peak shift operation, cooling / heat storage peak cut operation, cooling / heat storage non-use operation, heating / heat storage operation, heating / heat storage use operation, heating / heat storage non-use operation, heat storage / defrosting operation, heat storage / non-use Each operation mode of the defrosting operation is switched. Further, the capacity control compressor 1, the constant speed compressors 2a and 2b, the outdoor blowers 9a and 9b, and the indoor blowers 52a, 52b and 52c are operated and operated.
[0024]
Further, during operation, the outdoor expansion valves 7a and 7b, the liquid injection expansion valve 20 for the capacity control compressor, the liquid injection expansion valves 21a and 21b for the constant speed compressor, the indoor expansion valves 51a, 51b and 51c, and the heat storage circuit expansion valve 62. , The operation capacity of the displacement control compressor 1, the number of constant speed compressors 2a and 2b, and the like are controlled so as to be appropriate.
[0025]
Next, the flow of the refrigerant during the cooling heat storage operation will be described.
The high-pressure and high-temperature gas refrigerant discharged from the displacement control compressor 1 and the constant speed compressors 2a and 2b is condensed in the outdoor heat exchangers 6a and 6b via the four-way valve 5, and is supercooled in the subcoolers 8a and 8b. And reaches the regenerator 300 via the receiver 10, the gas-liquid heat exchanger 11, the liquid blocking valve 13, and the liquid connection pipe 41. Here, the heat storage circuit solenoid valves 63a and 63c are open, and the liquid refrigerant throttled by the heat storage circuit expansion valve 62 evaporates in the heat storage heat exchanger 61 to lower the water temperature to 0 ° C. or less. Heat is stored as latent heat by making ice. The evaporated gas refrigerant returns to the compressor low-pressure side via the heat storage circuit solenoid valve 63a, the heat storage gas connection pipe 42, the heat storage circuit solenoid valve 16b, the gas-liquid heat exchanger 11, and the accumulator 3.
[0026]
Next, the flow of the refrigerant during the cooling heat storage utilization peak shift operation will be described.
The high-pressure and high-temperature gas refrigerant discharged from the displacement control compressor 1 and the constant-speed compressors 2a and 2b is condensed in the outdoor heat exchangers 6a and 6b via the four-way valve 5, and is cooled by the subcoolers 8a and 8b, the receiver 10, The gas reaches the regenerator 300 via the gas-liquid heat exchanger 11, the liquid blocking valve 13, and the liquid connection pipe 41. Here, by opening the heat storage circuit electromagnetic valve 63b, the liquid refrigerant is guided to the heat storage heat exchanger 61 and exchanges heat with ice. The liquid refrigerant that has been supercooled and has a low specific enthalpy is conveyed to the indoor units 200a, 200b, and 200c, throttled by the indoor expansion valves 51a, 51b, and 51c, and evaporated by the indoor heat exchangers 50a, 50b, and 50c. Cooling is performed by exchanging heat with heat. The evaporated gas refrigerant is returned to the outdoor unit 100 from the gas connection pipe 40, and returns to the compressor low pressure side via the four-way valve 5, the gas-liquid heat exchanger 11, and the accumulator 3.
[0027]
In addition, since the specific enthalpy is greatly reduced in the heat storage heat exchanger 61 by exchanging heat with ice, the refrigerant circulating amount is reduced because the specific enthalpy difference between the inlet and the outlet of the indoor heat exchangers 50a, 50b, 50c is large. Therefore, the compressor operating capacity can be reduced and power consumption can be reduced.
[0028]
Next, the flow of the refrigerant during the peak cut operation using the cooling heat storage will be described.
The high-pressure and high-temperature gas refrigerant discharged from the displacement control compressor 1 and the constant speed compressors 2a and 2b reaches the heat storage device 300 via the heat storage circuit connection pipe 42 from the heat storage circuit solenoid valve 16b. Here, by opening the heat storage circuit solenoid valve 63a, the high-pressure high-temperature gas refrigerant is guided to the heat storage heat exchanger 61 and exchanges heat with ice. The liquid refrigerant thus condensed and supercooled and having a low specific enthalpy is conveyed to the indoor units 200a, 200b, and 200c, squeezed by the indoor expansion valves 51a, 51b, and 51c, and sent to the indoor heat exchangers 50a, 50b, and 50c. Cooling is performed by evaporating and exchanging heat with air. The vaporized gas refrigerant returns to the compressor low-pressure side similarly to the cooling heat storage utilization peak shift operation.
[0029]
Since the condensing pressure can be remarkably reduced by the heat exchange between the high-pressure and high-temperature gas refrigerant and ice, the power consumption of the compressor operation is greatly reduced in combination with the reduction of the specific enthalpy due to the supercooling. By performing the cooling heat storage use peak cut operation having a large power saving effect at 13:00 to 16:00 when the power peak during cooling appears, it is possible to contribute to the power leveling and reduce the contracted power.
[0030]
Next, the flow of the refrigerant in the cooling heat storage non-use operation after exhausting the heat storage will be described.
The high-pressure and high-temperature gas refrigerant discharged from the displacement control compressor 1 and the constant speed compressors 2a and 2b is condensed in the outdoor heat exchangers 6a and 6b via the four-way valve 5, and is supercooled in the subcoolers 8a and 8b. It is conveyed to the indoor units 200a, 200b, and 200c via the receiver 10, the gas-liquid heat exchanger 11, the liquid blocking valve 13, and the liquid connection pipe 41. At this time, the heat storage circuit solenoid valve 63c is in the open state. Cooling is performed by being throttled by the indoor expansion valves 51a, 51b, and 51c and evaporating in the indoor heat exchangers 50a, 50b, and 50c to exchange heat with air. Return to the side.
[0031]
Next, the flow of the refrigerant during the heating and heat storage operation will be described.
The high-pressure and high-temperature gas refrigerant discharged from the displacement control compressor 1 and the constant speed compressors 2a and 2b reaches the heat storage device 300 via the heat storage circuit connection pipe 42 from the heat storage circuit solenoid valve 16b. Here, when the heat storage circuit solenoid valve 63a is opened, the high-pressure high-temperature gas refrigerant is guided to the heat storage heat exchanger 61 and exchanges heat with water to raise the water temperature. The condensed liquid refrigerant returns to the outdoor unit 100 via the heat storage circuit expansion valve 62, the heat storage circuit solenoid valve 63c in the open state, and the liquid connection pipe 41, and returns to the gas-liquid heat exchanger 11, the receiver 10, and the supercooler. After 8a and 8b, they are expanded by the outdoor expansion valves 7a and 7b and evaporated by the outdoor heat exchangers 6a and 6b. The evaporated gas refrigerant returns to the compressor low-pressure side via the four-way valve 5, the gas-liquid heat exchanger 11, and the accumulator 3.
[0032]
Under conditions where the outside air temperature is low and the evaporation pressure is low, the supercooled liquid refrigerant in front of the outdoor expansion valve 7b is branched, and the capacity control compressor 1 and the constant speed compressors 2a and 2b are supplied to the capacity control compressor. Liquid injection expansion valve 20, liquid injection expansion valves 21a and 21b for constant speed compressor, liquid injection solenoid valve for capacity control compressor 22, liquid injection solenoid valves 23a and 23b for constant speed compressor, liquid injection for capacity control compressor The capillary tube 24 is connected to the liquid injection capillary tubes 25a and 25b for a constant speed compressor to perform liquid injection. At this time, the outdoor expansion valves 7a and 7b are controlled such that the degree of superheat calculated by the suction temperature sensor 34 and the low pressure sensor 37 becomes a target value. In addition, the liquid injection solenoid valves 23a and 23b for the constant speed compressor open only the operating compressor, and the liquid injection expansion valve 20 for the capacity control compressor and the liquid injection expansion valves 21a and 21b for the constant speed compressor. The liquid injection amount is controlled so that the discharge temperature of the compressor becomes appropriate by controlling the opening degree of the compressor.
[0033]
Since the liquid injection compressor is employed as described above, the refrigerant flow rate on the discharge side is ensured even under conditions where the outside air temperature is low, the density of refrigerant sucked into the compressor is reduced, and the amount of refrigerant circulated is reduced, so that high heating is achieved. The capacity can be maintained and the temperature of the water can be raised to secure the heat storage amount.
[0034]
Next, the flow of the refrigerant during the heating / heat storage utilizing operation will be described.
The high-pressure and high-temperature gas refrigerant discharged from the displacement control compressor 1 and the constant speed compressors 2a and 2b passes through the four-way valve 5 and is conveyed from the gas connection pipe 40 to the indoor units 200a, 200b and 200c, and the indoor heat exchanger 50a , 50b, 50c to condense and radiate heat for heating. Thereafter, the condensed liquid refrigerant is throttled by the heat storage circuit expansion valve 62 in the heat storage device 300 and exchanges heat with hot water in the heat storage heat exchanger 61 to evaporate. At this time, the heat storage circuit solenoid valve 63a is open, the gas refrigerant returns to the outdoor unit 100 from the heat storage gas connection pipe 42, and is compressed via the heat storage circuit solenoid valve 16b, the gas-liquid heat exchanger 11, and the accumulator 3. Return to machine low pressure side. At this time, the outdoor expansion valves 7a and 7b are fully closed and the outdoor blowers 9a and 9b are stopped without using the outdoor heat exchangers 6a and 6b at all.
[0035]
In this operation, since hot water is used as a heat source from the heat storage heat exchanger 61, a large amount of heat is obtained for evaporation of the refrigerant even when the outside air temperature is low, so that the evaporation pressure increases and the density of the compressor suction gas refrigerant decreases. As the temperature increases, the amount of circulating refrigerant increases, so that a very high capacity can be obtained, and the rise of warm air is quick. Further, since the outdoor heat exchangers 6a and 6b are not used, there is no need to perform a defrosting operation without frost formation. Furthermore, since the outdoor blowers 9a and 9b are also stopped, power consumption is reduced. Here, the heating capacity is suppressed, and the operating capacity of the capacity control compressor 1 and the operating number of the constant-speed compressors 2a and 2b are adjusted to operate the compressor with the compressor operating capacity smaller than that in the non-heating-using operation, thereby performing heating. The increased capacity can be used for reducing the operating power consumption, and a high heating capacity can be exhibited while also achieving a power saving effect.
[0036]
Also in the heating / heat storage operation, when the water temperature is high for a while after the operation is started, the evaporative gas refrigerant is overheated, so that the degree of superheat of the compressor suction section is increased, and the discharge temperature is increased. In this case, too, the liquid injection is used to control the amount of liquid injection so that the discharge temperature of each compressor becomes appropriate, as in the case of the heating and heat storage operation, thereby reducing the heat loss in the high-temperature section and improving the operation efficiency. At the same time, it is possible to reduce the deterioration of the organic material such as the insulating coating of the compressor motor and the refrigerating machine oil, thereby improving the reliability of the device.
[0037]
Next, the flow of the refrigerant during the heating / heat storage non-use operation will be described.
The operation is the same as the operation using the heat storage and storage operation until the heating is performed by condensing and radiating heat in the indoor heat exchangers 50a, 50b and 50c. However, in this operation, the liquid refrigerant is supplied to the outdoor unit 100 by opening the solenoid valve 63c for the heat storage circuit. Then, as in the case of the heating and heat storage operation, the refrigerant is evaporated in the outdoor heat exchangers 6a and 6b and returned to the compressor low pressure side.
[0038]
Under the condition that the outside air temperature is low and the evaporation pressure is low as in the heating and heat storage operation, the liquid injection is performed by the liquid injection expansion valve 20 for the capacity control compressor and the liquid injection expansion valves 21a and 21b for the constant speed compressor. The liquid injection amount is controlled so that the discharge temperature of the liquid becomes appropriate.
As a result, similarly to the heating heat storage operation, a high heating capacity can be maintained even under conditions in which the outside air temperature is low, the density of refrigerant sucked into the compressor is reduced, and the amount of circulating refrigerant is reduced. The flow of the refrigerant during the heat storage utilizing defrosting operation is the same as in the cooling heat storage operation, and the flow of the refrigerant during the heat storage non-using defrosting operation is the same as in the cooling non-using operation.
[0039]
Next, a method of switching the operation mode during the heating operation according to the present embodiment will be described with reference to FIG.
FIG. 2 shows a state of the heating operation according to the first embodiment of the present invention, in which a change in water temperature representing heating capacity, power consumption, and heat storage amount in one-day operation, and switching of the operation mode. This shows a change. The night heat storage operation will be described. At a preset time (22:00 in this example) from the timer, the heating / heat storage operation is started. Thereby, the water temperature in the heat storage tank gradually rises, and when this reaches a predetermined value, the heating heat storage operation is ended.
[0040]
Next, the air conditioning operation in the daytime will be described. When the operation is started early in the morning, the outside air temperature is low and the air-conditioning load is large, so a large capacity is required as shown in the graph showing the capacity in the figure. In the present embodiment, first, the operation is started in the heating / heat storage utilizing operation mode. Thereby, as described above, it is possible to obtain a power saving effect while exhibiting a high heating capacity, and it is possible to operate with lower power consumption than the power consumption when the heat storage is not used as indicated by the dotted line. When the heating / heat storage operation is continued, the water temperature decreases as a result of using the heat storage as a heat source. When this reaches a predetermined temperature (heat storage use operation once non-use transition temperature in the figure), the operation mode is temporarily shifted to the heating heat storage non-use operation. Since the temperature rises during the day and the air-conditioning load decreases during the day compared to the peak load in the early morning, the air-conditioning capacity can be within the applicable range even when the heating and storage non-use operation is performed with low air-conditioning capacity.
[0041]
In the present embodiment, even when the heating and heat storage non-use operation is performed, the heating capacity at a low outside air temperature is high due to the effect of the liquid injection use. By setting the heating capacity at the time of the heating / heat storage non-use operation to be approximately 85% or more of that at the time of the heating / heat storage utilization operation, it is possible to perform the operation while maintaining comfort without generating a heating capacity difference at the time of transition. it can. By setting the ratio of the capacity between the operation using the heat storage operation and the operation not using the heat storage in this ratio, the operation time of the heat storage operation in the air conditioning time zone at the peak load can be set to about 50% of the air conditioning time. An appropriate ratio can be set from the viewpoint of miniaturization and comfort of the tank.
[0042]
When the heating non-use operation is continued and the outside air temperature gradually decreases in the evening and the heating load increases, in the present embodiment, the operation mode is again shifted to the heating heat storage use operation mode, and an operation with a high heating capacity is performed. Regarding this timing, in the present embodiment, the operation mode is switched when a preset time comes.
[0043]
In the Hokkaido region, the winter power peak occurs between 16:00 and 18:00 in the evening, and in this embodiment, the heating and storage operation starts at 16:00 to include this time zone. The operation with low power consumption in the zone contributes to the reduction of peak power consumption. After returning to the heating use operation, when the heat storage use operation end temperature, which is the lower limit of the heat storage use temperature, is reached, the operation is switched back to the heat storage non-use operation. As described above, even when the outside air temperature is low, the heat storage using the liquid injection compressor, which can maintain the heating capacity during the day when the heating / air-conditioning load is relatively small can be maintained to the extent that the load decreases, is not used. Since the operation using heat storage can be divided into morning and evening by performing the operation, the heat storage capacity can be reduced as compared with the case where the operation using the heat storage and storage is performed during the entire air conditioning, and the installation area of the equipment can be reduced and the operation can be reduced. The weight can be reduced. In addition, since the operation with low power consumption is performed during the power peak generation time from 16:00 to 18:00, it is effective in reducing the peak power consumption and is effective in promoting the power leveling.
[0044]
Next, a second embodiment of the present invention will be described.
FIG. 3 is a block diagram showing a refrigeration cycle configuration according to the second embodiment of the present invention. The reference numerals are the same as in the first embodiment of the present invention. However, as the capacity control compressor 1 and the constant speed compressors 2a and 2b, a normal scroll type compressor which is not a liquid injection type is adopted. Therefore, it is different from the first embodiment in that it does not have a refrigerant circuit for liquid injection. .
[0045]
Next, the operation of the second embodiment of the present invention will be described.
This embodiment is basically the same as the first embodiment of the present invention in the case where only the liquid injection is eliminated. Therefore, only the heating / heat storage combined operation which is an operation mode different from those will be described.
[0046]
The flow of the refrigerant in the combined heating and storage operation is shown below.
The high-pressure and high-temperature gas refrigerant discharged from the displacement control compressor 1 and the constant speed compressors 2a and 2b passes through the four-way valve 5 and is conveyed from the gas connection pipe 40 to the indoor units 200a, 200b and 200c, and the indoor heat exchanger 50a , 50b, 50c to condense and radiate heat for heating. Thereafter, the condensed liquid refrigerant flows into the following two parts.
[0047]
One of them is throttled by the heat storage circuit expansion valve 62 in the heat storage device 300, exchanges heat with hot water in the heat storage heat exchanger 61, evaporates, and is connected to the outdoor unit through the heat storage gas connection pipe 42 from the heat storage circuit electromagnetic valve 63 a. The flow returns to 100 and returns to the compressor low pressure side via the heat storage circuit solenoid valve 16b, the gas-liquid heat exchanger 11, and the accumulator 3.
[0048]
The other returns to the outdoor unit 100 via the heat storage circuit solenoid valve 63c, and after the gas-liquid heat exchanger 11, the receiver 10, and the subcoolers 8a and 8b, expands at the outdoor expansion valves 7a and 7b to generate outdoor heat. It evaporates in exchangers 6a and 6b. The evaporated gas refrigerant returns to the compressor low-pressure side via the four-way valve 5, the gas-liquid heat exchanger 11, and the accumulator 3.
[0049]
Since the refrigerant flows as described above, the liquid refrigerant absorbs heat from both heat storage and air as the evaporation heat source. Thereby, compared with the case where no heat storage is used as a heat source, that is, as compared with the case of the heating heat storage non-use operation in the first embodiment, it is less likely to be affected by outside air, and a relatively high heating capacity can be obtained. it can.
[0050]
Next, a method of switching the operation mode during the heating operation according to the present embodiment will be described with reference to FIG.
FIG. 4 shows the state of the heating operation in the second embodiment. The difference from FIG. 2 showing the operation state of the first embodiment is that when the operation is temporarily shifted to the heating / heat storage utilizing operation in the daytime. The point is that the combined operation of heating and heat storage is performed. The heating / storage combined operation uses both heat storage and air heat exchange as heat sources, and thus has a relatively high heating capacity even at low outside temperatures. Thus, as in the first embodiment, even when the outside air temperature is low, the heat storage heat source can be maintained at a sufficient level during the day when the heating / air-conditioning load is relatively small, so that the heat storage heat source can keep up with the decrease in the load. Since the operation that uses heat storage exclusively can be divided into morning and evening, the heat storage capacity can be reduced compared to the case where the heating and heat storage operation is performed during the entire air-conditioning period. The area can be reduced and the operating mass can be reduced. However, the heat storage capacity may be slightly larger than in the first embodiment because of the heat storage combined operation. On the other hand, the liquid injection compressor and the liquid injection refrigerant circuit become unnecessary, and the number of parts can be reduced.
[0051]
Next, a third embodiment of the present invention will be described.
FIG. 5 shows a state of the heating operation in the third embodiment. As in the first embodiment and the second embodiment, the heating and heat storage non-use operation or the heating and heat storage non-use operation is temporarily changed from the heating and heat storage use operation. In the case where the operation is switched to the heat storage combined operation, the operation in the case where the capacity corresponds to a low load state with respect to a high load state (thin line) is shown in the figure.
[0052]
When the load is small and the heating capacity has an allowance, the amount of heat storage is reduced, and there is a possibility that the heat storage will not be used up at the end of the air conditioning operation but will be left over. In the present embodiment, as shown in FIG. 5, when the water temperature is higher than a predetermined time, the control for switching the heating heat storage use operation is not performed, and the heat storage use is continued until the end.
[0053]
Accordingly, when the load is small, such as in the intermediate period, the unused operation is not performed on the way, so that the heat storage utilization rate is low and the heat storage is not left, and wasteful power consumption due to heat loss can be reduced. .
[0054]
Next, fourth and fifth embodiments of the present invention will be described.
FIG. 6 shows a state of the heating operation in the fourth embodiment, and FIG. 7 shows a state of the heating operation in the fifth embodiment. This embodiment shows a determination method in the same manner as FIG. 2 in the first embodiment of the present invention in a case where the heating / heat storage operation is temporarily stopped from the heating / heat storage operation, and then switched to the heating / heat storage operation again. . In both cases, when the heating capacity is low, the heating heat storage utilization operation is performed. FIG. 6 illustrates a case where the required capacity is calculated based on a difference between an indoor set temperature and a suction temperature set by a remote controller, for example. When the heat storage utilization temporarily falls below the transfer capacity, the operation shifts to the heating / heat storage non-use operation, and when the evening air conditioning load increases and exceeds the heat storage utilization operation restart capability in the figure, the operation is switched to the heating / heat storage utilization operation.
[0055]
On the other hand, FIG. 7 determines the heating capacity based on the compressor operating capacity. When the total compressor operating frequency exceeds the heat storage non-use operation upper limit frequency in the figure, the heating heat storage use operation is performed. In such a case, the operation that does not use the heat storage is performed. Since the switching is performed based on the heating capacity, that is, the numerical value indicating the load, the heating / heat storage operation can be performed more reliably when the heating capacity is required.
[0056]
According to the above-described embodiment, since the operation using heat storage can be divided into morning and evening, the heat storage capacity can be reduced as compared with the case where the heating and heat storage operation is performed during the entire air-conditioning time, and the equipment installation area can be reduced. And operating weight can be reduced.
[0057]
In addition, in heating operation, high heating capacity is exhibited in the early morning when the heating load is high, such as in the early morning, and operation can be performed with reduced power consumption during the peak power hours in the evening, thus contributing to power leveling. it can.
[0058]
Furthermore, since the heat storage non-use operation is not performed in the middle when the load is small, such as in the intermediate period, the heat storage utilization rate is low, so that heat storage is not left, and wasteful power consumption due to heat loss can be reduced. .
[0059]
Furthermore, since the heat storage use operation is continued without performing the heat storage non-use operation by detecting the case where the heating load is small and the heat storage consumption amount is small, since the heat storage does not remain even after the air conditioning operation ends, Heat loss due to heat radiation around the heat storage tank can be reduced, and operation efficiency is improved.
[0060]
【The invention's effect】
As described above, according to the present invention, even in a cold region, a sufficient heating capacity can be exhibited, the heat storage capacity can be reduced, the installation area of the device can be reduced, and the operating mass can be reduced. .
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a refrigeration cycle according to an embodiment of the present invention.
FIG. 2 is a graph showing a state of a heating operation in one embodiment of the present invention.
FIG. 3 is a block diagram showing a refrigeration cycle configuration according to another embodiment of the present invention.
FIG. 4 is a graph showing a state of a heating operation according to another embodiment of the present invention.
FIG. 5 shows a state of a heating operation according to still another embodiment of the present invention.
FIG. 6 is a graph showing a state of a heating operation according to still another embodiment of the present invention.
FIG. 7 is a graph showing a state of a heating operation in still another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Capacity control compressor, 2a, 2b ... Constant speed compressor, 3 ... Accumulator, 4 ... Oil separator, 5 ... Four-way valve, 6a, 6b ... Outdoor heat exchanger, 7a, 7b ... Outdoor expansion valve, 8a, 8b ... supercooler, 9a, 9b ... outdoor blower, 10 ... receiver, 11 ... gas liquid heat exchanger, 12 ... gas check valve, 13 ... liquid check valve, 14 ... heat storage gas check valve, 15 ... gas bypass, 16a, 16b: Solenoid valve for heat storage circuit, 20: Liquid injection expansion valve for displacement control compressor, 21a, 21b: Liquid injection expansion valve for constant speed compressor, 22 ... Liquid injection solenoid valve for displacement control compressor, 23a, 23b ... Liquid injection solenoid valve for constant speed compressor, 24 ... Liquid injection capillary tube for volume control compressor, 25a, 25b ... Liquid injection cap for constant speed compressor Rally tube, 30 ... Outdoor controller, 31 ... Outdoor temperature sensor, 32 ... Discharge temperature sensor for displacement control compressor, 33a, 33b ... Discharge temperature sensor for constant speed compressor, 34 ... Suction temperature sensor, 36 ... High pressure sensor 37, low pressure sensor, 40, gas connection pipe, 41, liquid connection pipe, 42, heat storage gas connection pipe, 45, transmission line, 50a, 50b, 50c, indoor heat exchanger, 51a, 51b, 51c, indoor expansion Valve, 52a, 52b, 52c: indoor blower, 53a, 53b, 53c: indoor control device, 54a, 54b, 54c: indoor suction temperature sensor, 55a, 55b, 55c: remote controller, 60: heat storage tank, 61: heat storage heat Exchanger, 62: expansion valve for heat storage circuit, 63a, 63b: solenoid valve for heat storage circuit, 65: heat storage control device, 66: heat storage medium Degree sensor, thermal storage controller 67,100 ... the outdoor unit, 200a, 200b, 200c ... the indoor unit, 300 ... regenerator.

Claims

Equipped with an outdoor unit having a compressor and an outdoor heat exchanger, a heat storage heat exchanger, and an indoor unit having an indoor heat exchanger, and switching between heating heat storage operation, heat storage use heating operation, and heat storage non-use heating operation. In regenerative heat pump air conditioners,
The operation is started in the heat storage use heating operation, and when it is determined that the air conditioning load is relatively small, the operation is switched to the heat storage non-use heating operation. A regenerative heat pump air conditioner for use in cold regions characterized by performing a heating operation.

The air conditioner according to claim 1, further comprising a time-measuring device, wherein when a predetermined time is reached, the heating operation is switched from the non-heat storage heating operation to the heat storage utilization heating operation. Harmony machine.

2. The heat storage heat pump air conditioner according to claim 1, wherein a time zone in which the operation using the heat storage heat exchanger mainly as an evaporator is performed from 16:00 to 18:00.

2. The compressor according to claim 1, wherein the compressor is adapted to inject the liquid refrigerant from the refrigerant suction section to the intermediate pressure section in the process of compressing the refrigerant discharge section, and controls an amount of the liquid refrigerant to be injected. A liquid storage heat pump air conditioner for a cold region, comprising: a liquid injection flow control device that performs the operation in which the liquid injection amount is controlled by the liquid injection flow control device during the heat storage non-heating heating operation.

2. The heat storage non-use heating operation in which the air conditioning load is determined to be relatively small according to claim 1, wherein the outdoor heat exchanger and the heat source of the heat storage heat exchanger are operated in combination. A regenerative heat pump air conditioner for cold regions.

2. The heat storage heat pump for a cold district according to claim 1, wherein the heating capacity in the heat storage non-use heating operation is 85% or more and less than 100% of the heating capacity in the heat storage use heating operation. Air conditioner.

2. The air conditioner according to claim 1, wherein, when the heat storage amount remains at a predetermined time or more at a predetermined time, when the air conditioning load is determined to be relatively small, the heat storage utilizing heating operation is continued. A regenerative heat pump air conditioner for cold regions.

The air conditioner according to claim 1, wherein the air conditioning load is calculated based on a suction temperature of the indoor unit or a difference between the suction temperature and a set temperature.

A compressor adapted to be injected with liquid, an outdoor unit having an outdoor heat exchanger, a heat storage heat exchanger, and an indoor unit having an indoor heat exchanger are provided. In regenerative heat pump air conditioners that switch between heat storage non-heating heating operation,
It is provided with a liquid injection flow rate control device that controls the liquid injection amount, starts operation in the heat storage use heating operation, and is switched to the heat storage non-use heating operation in which the liquid injection amount is controlled. Regenerative heat pump air conditioner.