【０００１】
【発明の属する技術分野】
本発明は、蓄熱式空気調和装置に関する。
【０００２】
【従来の技術】
一般に、昼間の冷暖房能力を高めるため、冷暖房運転しない夜間に水等の蓄熱材を充填した蓄熱槽に冷熱あるいは温熱を蓄え、その蓄熱を昼間の冷暖房運転に利用する蓄熱式空気調和装置が知られている。また、圧縮機を２台並列に設け、昼間の冷暖房能力を高めるとともに、夜間の蓄熱能力をもたかめるようにし、必要に応じて圧縮機を１台で運転することによりエネルギ損失を低減することが知られている（例えば、特許文献１参照）。
【０００３】
一方、このような蓄熱式空気調和装置において、蓄熱運転を行う夜間に冷暖房運転を行いたいという要望がある。この要望を満たすため、蓄熱器と室内機とを並列に接続して冷凍サイクルを構成することにより、蓄熱運転と冷暖房運転を同時に行うことが提案されている（例えば、特許文献２参照）。
【０００４】
【特許文献１】
特開平９−２６１８２号公報（第２−３頁、第１図）
【特許文献２】
特開平１１−１８７８２９号公報（第２−３頁、第１図）
【０００５】
【発明が解決しようとする課題】
しかしながら、例えば冷房運転の場合、通常蓄熱槽にて製氷をおこなう蓄熱運転温度よりも、室内の冷房運転温度が高いことから、蓄熱熱交換器の冷媒蒸発圧力よりも室内熱交換器の冷媒蒸発圧力を高く保持する必要がある。
【０００６】
この点、特許文献２に記載の蓄熱式空気調和装置によれば、室内熱交換器から圧縮機に至る冷媒ガス流路に弁を設け、この弁の絞りにより室内熱交換器の蒸発圧力を高く保持するようにしていることから、その弁の圧力損失によりエネルギ効率が低下してしまうという問題がある。
【０００７】
本発明の課題は、蓄熱運転と冷暖房運転を同時に行うとともに、エネルギ効率を向上することにある。
【０００８】
【課題を解決するための手段】
本発明は、次に述べる手段により、上記課題を解決するものである。すなわち、室内熱交換器と蓄熱熱交換器のそれぞれに圧縮機を設け、室内熱交換器と蓄熱熱交換器の冷媒蒸発圧力を個別に調整できるようにしたものである。これによれば、室内熱交換器の冷媒蒸発圧力を調整するための弁が省略でき、その弁を省略した分だけ圧力損失を低減できる。つまり、蓄熱運転と冷暖房運転を同時に行うとともに、エネルギ効率を向上することができるのである。
【０００９】
具体的に、本発明の蓄熱式空気調和装置は、蓄熱熱交換器と、室内熱交換器と、室外熱交換器と、第１と第２の圧縮機とを備え、室外熱交換器の液側配管を分岐してそれぞれ膨張弁を介して蓄熱熱交換器の液側配管と室内熱交換器の液側配管とに接続する。さらに、冷暖切替弁により、蓄熱熱交換器のガス側配管を第１の圧縮機の吐出側又は吸入側に接続し、室内熱交換器のガス側配管を第２の圧縮機の吐出側又は吸入側に接続し、室外熱交換器のガス側配管を第１と第２の圧縮機の吸入側又は吐出側に接続する構成とする。
【００１０】
ここで、室外熱交換器の液側配管に第１の開閉弁を設け、この第１の開閉弁の室外熱交換器側の液側配管と、蓄熱熱交換器のガス側配管とを第２の開閉弁を介して連結することができる。このように第１と第２の開閉弁を設けることで、蓄熱運転、冷暖房運転、蓄熱した熱を冷暖房に利用する蓄熱利用運転、及び蓄熱運転と冷暖房運転を同時に行う並列運転の４パターンの運転を行うことができる。すなわち、蓄熱運転、冷暖房運転、及び並列運転は、第１の開閉弁を開き、第２の開閉弁を閉じて、第１と第２の圧縮機の少なくとも一方を駆動して行う。蓄熱利用運転は、第１の開閉弁を閉じ、第２の開閉弁を開いて、第２の圧縮機のみを駆動して行う。
【００１１】
また、これに代えて、室外熱交換器の液側配管と室内熱交換器の膨張弁とを接続する分岐配管に第１の開閉弁を設け、この第１の開閉弁と膨張弁との間の分岐配管と、蓄熱熱交換器のガス側配管とを第２の開閉弁を介して連結する構成とすることができる。この場合も第１と第２の開閉弁を同様に制御することで４パターンの運転を行うことができる。
【００１２】
さらに、室内熱交換器のガス側配管と、蓄熱熱交換器のガス側配管とを第３の開閉弁を介して連結することができる。この第３の開閉弁を開くことで、第１と第２の圧縮機を並列に接続することができる。したがって、例えば、第１と第２の圧縮機を室内熱交換器に接続すれば、室内熱交換器に供給する冷媒の量を増やせるから、過大な空調負荷がかかった場合などに対応できる。また、蓄熱熱交換器に接続すれば、蓄熱完了までにかかる時間を短縮できる。
【００１３】
また、室外熱交換器を２個設け、冷暖切替弁を介して、一方の室外熱交換器のガス側配管に第１の圧縮機を接続し、他方の室外熱交換器のガス側配管に第２の圧縮機を接続することができる。これによれば、２台の圧縮機と１つの室外熱交換器を有し、１本の液側配管と２本のガス側配管が接続されるような特殊な形態の室外機を用いることではなく、１台の圧縮機と１つの室外熱交換器を有し１本の液側配管と１本のガス側配管が接続される汎用の室外機を転用して本発明の蓄熱式空気調和装置を形成することができる。
【００１４】
このように複数の室外熱交換器を備えた構成において、接続された圧縮機が運転していない場合、室外熱交換器内に冷媒が流れ込んで溜まり、装置全体の冷媒循環量が変化することがある。通常、冷凍サイクルは一定の冷媒が循環することを前提に設計されているので、冷媒循環量が変化すると温度制御などを適切に行うことができなくなる問題がある。そこで、各室外熱交換器の液側配管に第４の開閉弁を設けることが好ましい。この第４の弁を閉じれば、運転していない圧縮機が接続された室外熱交換器に液側配管から冷媒が流入することを防止でき、冷媒の循環量が変化することを回避できる。
【００１５】
【発明の実施の形態】
（第１の実施形態）
以下、本発明の蓄熱式空気調和装置の第１の実施の形態について、図１を用いて説明する。図１は本発明を適用してなる蓄熱式空気調和装置の概略構成図である。本実施形態の蓄熱式空気調和装置は、蓄熱熱交換器１、複数の（本実施形態では２つの）室内熱交換器３、室外熱交換器５、及び圧縮機７、８を備えた冷凍サイクルを形成している。蓄熱熱交換器１は、蛇行させた伝熱管で形成され、蓄熱槽１１内に配置されている。蓄熱槽１１内には、水または水を主とする蓄熱用水１３が貯留され、蓄熱熱交換器１は蓄熱用水１３に浸漬するようになっている。
【００１６】
室外熱交換器５は、内部を通流する冷媒と外気との熱交換を行うように形成されている。室外熱交換器５は、液側配管１５とガス側配管１７とを備えている。液側配管１５の先端には、分岐配管１９、２１の一端がそれぞれ連結されている。分岐配管１９の他端は、膨張弁２３を介して蓄熱熱交換器１の液側配管２５に連結されている。蓄熱熱交換器１のガス側配管２７は、四方弁２９に接続され、四方弁２９は、室外熱交換器５のガス側配管１７に接続されている。四方弁２９は、ガス側配管１７を圧縮機７の吐出側または吸入側のいずれか一方に切替えて連通させ、他方をガス側配管２７に連通させるようになっている。
【００１７】
室外熱交換器５の液側配管１５から分岐した分岐配管２１の他端は、さらに分岐して、２つの膨張弁３１にそれぞれ接続されている。各膨張弁３１は、各室内熱交換器３の液側配管３３に接続されている。各室内熱交換器３のガス側配管は、互いに連結して１本のガス側配管３５を形成している。ガス側配管３５は、四方弁３７に接続され、四方弁３７は、室外熱交換器５のガス側配管１７に接続されている。四方弁３７は、ガス側配管１７を圧縮機８の吐出側または吸入側のいずれか一方に切替えて連通させ、他方をガス側配管３５に連通させるようになっている。
【００１８】
第１の開閉弁である開閉弁３９は、室外熱交換器５の液側配管１５に設けられている。室外熱交換器５と開閉弁３９の間の液側配管１５と、蓄熱熱交換器１のガス側配管２７とを連結するバイパス管４１が設けられている。バイパス管４１には、第２の開閉弁である開閉弁４３が設けられている。バイパス管４１と四方弁２９の間のガス側配管２７と、室内熱交換器３のガス側配管３５とを連結するバイパス管４５が設けられ、バイパス管４５には第３の開閉弁である開閉弁４７が設けられている。ガス側配管２７のうち、バイパス管４１とバイパス管４５とで挟まれた部分に開閉弁４９が設けられている。
【００１９】
蓄熱槽１、膨張弁２３、及び開閉弁３９、４３、４７、４９は蓄熱ユニット５１に、室内熱交換器３、及び膨張弁３１は室内ユニット５３に、室外熱交換器５、圧縮機７、８、及び膨張弁２９、３７は室外ユニット５５にそれぞれ格納されている。また、開閉弁３９、４３、４７、４９の開閉、膨張弁２３、３１の開度、四方弁２９、３７の切替え、及び圧縮機７、８の運転周波数は、図示していない制御装置により制御されるようになっている。
【００２０】
このように構成された蓄熱式空気調和装置の運転モード及び動作について冷房時を例に挙げて説明する。この冷房時において、四方弁２９、３７は、図中の実線に示すように接続される。すなわち、四方弁２９は、圧縮機７の吐出側を室外熱交換器５のガス側配管１７に連結し、吸入側を蓄熱熱交換器１のガス側配管２７に連結する。四方弁３７は、圧縮機８の吐出側を室外熱交換器５のガス側配管１７に連結し、吸入側を室内熱交換器３のガス側配管３５に連結する。
（蓄熱運転モード）
蓄熱運転を単独で行う場合、制御装置は、開閉弁４３、４７、及び膨張弁３１を閉じ、開閉弁３９、４９を開き、膨張弁２３の開度を適宜調整して、圧縮機７を駆動する。これにより、圧縮機７で圧縮されたガス冷媒は、四方弁２９、ガス側配管１７を介して室外熱交換器５に導かれ、外気との熱交換により凝縮して液冷媒となり、液側配管１５、開閉弁３９及び分岐配管１９を通流し、膨張弁２３に導かれる。膨張弁２３で減圧された液冷媒は、蓄熱熱交換器１で蓄熱槽１１内の蓄熱用水１３と熱交換して蒸発する。この結果、蓄熱槽１１内の蓄熱用水１３の温度が低下し、蓄熱熱交換器１の回りに氷が徐々に形成される。その後、蒸発したガス冷媒は、蓄熱熱交換器１のガス側配管２７、開閉弁４９、及び四方弁２９を通って圧縮機７の吸入側に戻される。
（冷房運転モード）
冷房運転を単独で行う場合、制御装置は、開閉弁４３、４７、４９、及び膨張弁２３を閉じ、開閉弁３９を開き、膨張弁３１の開度を適宜調整し、例えば、冷媒圧力や冷媒温度などから求めた室内熱交換器３の負荷に応じて圧縮機８の運転周波数を制御する。これにより、圧縮機８で圧縮されたガス冷媒は、四方弁３７、ガス側配管１７を介して室外熱交換器５に流入し、外気との熱交換により凝縮して液冷媒となる。室外熱交換器５から排出された液冷媒は、液側配管１５、開閉弁３９及び分岐配管２１を通流し、膨張弁３１に導かれる。膨張弁３１で減圧された液冷媒は、室内熱交換器３で室内の空気と熱交換して蒸発し、室内の空気の温度を低下させる。その後、蒸発したガス冷媒は、室内熱交換器３のガス側配管３５、及び四方弁３７を通って圧縮機８の吸入側に戻される。
（蓄熱利用運転モード）
蓄熱を利用して冷房運転する場合、制御装置は、開閉弁３９、４７、及び４９を閉じ、開閉弁４３を開き、膨張弁２３の開度を全開にし、室内熱交換器３の冷媒圧力や冷媒温度に応じて圧縮機８の運転周波数と膨張弁３１の開度を適宜調整する。これにより、圧縮機８で圧縮されたガス冷媒は、四方弁３７、ガス側配管１７を介して室外熱交換器５に流入し、外気との熱交換により凝縮して液冷媒となり、液側配管１５、バイパス管４１、開閉弁４３及びガス側配管２７を介して蓄熱熱交換器１に流入する。この液冷媒は、蓄熱熱交換器１を通流する際、蓄熱用水１３に蓄えられた冷熱によって冷却される。冷却された液冷媒は、分岐配管１９、２１及び膨張弁３１を介して室内熱交換器３に導かれる。この結果、液冷媒の過冷却度が増加し、その分の冷熱量を室内の空気の冷却に利用できる。その後、室内熱交換器３内で蒸発した冷媒は、室内熱交換器３のガス側配管３５、及び四方弁３７を通って圧縮機８の吸入側に戻される。
【００２１】
また、蓄熱運転時、冷房運転時及び蓄熱利用運転において、開閉弁４７を開くことで、圧縮機７、８を並列に接続して運転することができる。これによれば、蓄熱熱交換器１や室内熱交換器３の負荷に応じて、例えば、負荷が小さいときに運転台数を減らすことができ、運転の効率を向上することができる。
（並列運転モード）
次に、本実施形態の特徴部である蓄熱と冷房を同時に行う並列運転する場合について説明する。まず、制御装置は、開閉弁４３、及び４７を閉じ、開閉弁３９、及び４９を開き、膨張弁２３、３１の開度を適宜調整する。そして、蓄熱熱交換器１の負荷に応じて圧縮機７の運転周波数を調整するとともに、室内熱交換器３の負荷に応じて圧縮機８の運転周波数を調整する。これにより、圧縮機８で圧縮されたガス冷媒は、圧縮機７で圧縮されたガス冷媒とガス側配管１７で合流し、室外熱交換器５内で凝縮され、一部は膨張弁２３に導かれ、残りの冷媒は膨張弁３１に導かれる。膨張弁２３に導かれた冷媒は、前述の蓄熱運転と同様に蓄熱熱交換器１で蒸発して圧縮機７に戻る。一方、膨張弁３１に導かれた冷媒は、前述の冷房運転と同様に室内熱交換器３で蒸発して圧縮機８に戻る。
【００２２】
このように本実施形態によれば、蓄熱熱交換器１の冷媒と、室内熱交換器３の冷媒を別々の圧縮機で吸入できるから、蓄熱熱交換器１と室内熱交換器３とを異なる冷媒圧力にすることができ、例えば、蓄熱槽１１内の氷が成長して圧縮機７の吸入圧力が低くなっても、それぞれの冷媒圧力を適正に保つことができる。したがって、室内熱交換器の冷媒圧力を調整するために、室内熱交換器のガス側に設けていた弁を省略できるので、その弁による圧力損失の分だけエネルギ効率を向上できる。すなわち、蓄熱運転と冷暖房運転を同時に行うとともに、エネルギ効率を向上できる。さらに、蓄熱熱交換器１と室内熱交換器３にかかる負荷に合わせてそれぞれの圧縮機を駆動できるから効率のよい運転を行うことができる。
【００２３】
また、本実施形態では、冷房運転を例に挙げて説明したが、暖房運転を行う場合は、四方弁２９、３７を図中の点線で示すように接続する。すなわち、四方弁２９は、圧縮機７の吐出側を蓄熱熱交換器１のガス側配管２７に連結し、吸入側を室外熱交換器５のガス側配管１７に連結する。四方弁３７は、圧縮機８の吐出側を室内熱交換器３のガス側配管３５に連結し、吸入側を室外熱交換器５のガス側配管１７に連結する。この場合、冷媒の循環方向が逆になる。
（第２の実施形態）
図２に本発明に係る蓄熱式空気調和装置の第２の実施形態の概略構成を示す。本実施形態が上記実施形態と異なる点は、室外熱交換器５を２つ設け、それぞれを圧縮機７、８に接続したことにある。したがって、上記実施形態と同一の構成には同一の符号を付して説明を省略する。
【００２４】
具体的に本実施形態の蓄熱式空気調和装置は、室外熱交換器５Ａ、５Ｂを備え、蓄熱熱交換器１のガス側配管２７は、四方弁２９に接続され、四方弁２９は、室外熱交換器５Ａのガス側配管１７Ａに接続されて、ガス側配管１７Ａを圧縮機７の吐出側または吸入側のいずれか一方に切替えて連通させ、他方をガス側配管２７に連通させるようになっている。また、室内熱交換器３のガス側配管３５は、四方弁３７に接続され、四方弁３７は、室外熱交換器５Ｂのガス側配管１７Ｂに接続され、ガス側配管１７Ｂを圧縮機８の吐出側または吸入側のいずれか一方に切替えて連通させ、他方をガス側配管３５に連通させるようになっている。また、室外熱交換器５Ａ、５Ｂの液側配管には、それぞれ第４の開閉弁である開閉弁６１、６３が設けられている。室外熱交換器５Ａ、５Ｂの液側配管は、互いに連結して１本の液側配管１５を形成している。また、室外ユニット５５は、２つのサブユニット５７、５９を備えて構成されている。サブユニット５７には、圧縮機７、四方弁２９、及び室外熱交換器５Ａが格納され、サブユニット５９には、圧縮機８、四方弁３７、及び室外熱交換器５Ｂが格納されている。
【００２５】
このように本実施形態によれば、１台の圧縮機、もしくは例えば並列に接続された複数台の圧縮機と１つの室外熱交換器を有し、１本の液側配管と１本のガス側配管が接続される汎用の室外ユニット（サブユニット５７、５９）で蓄熱式空気調和装置を形成することができるので好ましい。また、開閉弁６１、６３を設けることで、サブユニットを運転していない場合に、その停止中のサブユニットに液側配管１５から冷媒が流れ込むことを防止でき、装置全体の冷媒循環量が減ることを回避できる。
【００２６】
また、本実施形態では、開閉弁６１、６３を室外ユニット内の配管に設けたが、図３に示すように蓄熱ユニット内の配管に設けることもできる。このようにいずれかのユニット内に配置することで開閉弁６１、６３に容易に電源を供給できる。また、これに限らず、例えば、室外ユニットと蓄熱ユニットを接続する液側配管に設けてもよい。また、本実施形態では、サブユニットを２台の構成を示したが、これに限らず、複数台並列に配置してもよい。
【００２７】
【発明の効果】
以上述べたように、本発明によれば、蓄熱運転と冷暖房運転を同時に行うとともに、エネルギ効率を向上できる。
【図面の簡単な説明】
【図１】本発明を適用してなる蓄熱式空気調和装置の第１の実施形態の概略構成図である。
【図２】本発明を適用してなる蓄熱式空気調和装置の第２の実施形態の概略構成図である。
【図３】本発明を適用してなる蓄熱式空気調和装置の第２の実施形態の変形例の概略構成図である。
【符号の説明】
１ 蓄熱熱交換器
３ 室内熱交換器
５ 室外熱交換器
７、８ 圧縮機[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat storage type air conditioner.
[0002]
[Prior art]
In general, in order to increase daytime air conditioning capacity, a regenerative air conditioner is known that stores cold heat or heat in a heat storage tank filled with a heat storage material such as water at night without air conditioning operation, and uses the stored heat for daytime air conditioning operation. ing. In addition, two compressors can be installed in parallel to increase daytime cooling and heating capacity, to increase nighttime heat storage capacity, and to reduce energy loss by operating a single compressor as needed. It is known (see, for example, Patent Document 1).
[0003]
On the other hand, in such a heat storage type air conditioner, there is a desire to perform a cooling / heating operation at night when the heat storage operation is performed. In order to satisfy this demand, it has been proposed to simultaneously perform a heat storage operation and an air conditioning operation by connecting a heat accumulator and an indoor unit in parallel to form a refrigeration cycle (see, for example, Patent Document 2).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-26182 (page 2-3, FIG. 1)
[Patent Document 2]
JP-A-11-187829 (page 2-3, FIG. 1)
[0005]
[Problems to be solved by the invention]
However, for example, in the case of cooling operation, since the indoor cooling operation temperature is higher than the heat storage operation temperature in which ice is normally produced in the heat storage tank, the refrigerant evaporation pressure of the indoor heat exchanger is higher than the refrigerant evaporation pressure of the heat storage heat exchanger. Need to be kept high.
[0006]
In this regard, according to the regenerative air conditioner described in Patent Document 2, a valve is provided in the refrigerant gas flow path from the indoor heat exchanger to the compressor, and the evaporation pressure of the indoor heat exchanger is increased by restricting the valve. Since it is made to hold | maintain, there exists a problem that energy efficiency will fall by the pressure loss of the valve.
[0007]
An object of the present invention is to simultaneously perform a heat storage operation and an air conditioning operation and improve energy efficiency.
[0008]
[Means for Solving the Problems]
The present invention solves the above problems by the following means. That is, a compressor is provided in each of the indoor heat exchanger and the heat storage heat exchanger so that the refrigerant evaporation pressure of the indoor heat exchanger and the heat storage heat exchanger can be individually adjusted. According to this, the valve for adjusting the refrigerant | coolant evaporation pressure of an indoor heat exchanger can be abbreviate | omitted, and a pressure loss can be reduced only by the part which omitted the valve. That is, the heat storage operation and the cooling / heating operation can be performed simultaneously and the energy efficiency can be improved.
[0009]
Specifically, the regenerative air conditioner of the present invention includes a regenerative heat exchanger, an indoor heat exchanger, an outdoor heat exchanger, and first and second compressors, and a liquid in the outdoor heat exchanger. The side pipes are branched and connected to the liquid side pipes of the heat storage heat exchanger and the liquid side pipes of the indoor heat exchanger via expansion valves, respectively. Furthermore, the gas side piping of the heat storage heat exchanger is connected to the discharge side or suction side of the first compressor and the gas side piping of the indoor heat exchanger is connected to the discharge side or suction of the second compressor by the cooling / heating switching valve. The gas side piping of the outdoor heat exchanger is connected to the suction side or the discharge side of the first and second compressors.
[0010]
Here, the first on-off valve is provided in the liquid side pipe of the outdoor heat exchanger, and the liquid side pipe on the outdoor heat exchanger side of the first on-off valve and the gas side pipe of the heat storage heat exchanger are connected to the second side. It can be connected via an on-off valve. By providing the first and second on-off valves in this way, the heat storage operation, the air conditioning operation, the heat storage use operation that uses the stored heat for air conditioning, and the parallel operation that simultaneously performs the heat storage operation and the air conditioning operation are performed. It can be performed. That is, the heat storage operation, the air conditioning operation, and the parallel operation are performed by opening the first on-off valve, closing the second on-off valve, and driving at least one of the first and second compressors. The heat storage utilization operation is performed by closing the first on-off valve, opening the second on-off valve, and driving only the second compressor.
[0011]
Instead of this, a first on-off valve is provided in a branch pipe connecting the liquid side pipe of the outdoor heat exchanger and the expansion valve of the indoor heat exchanger, and between the first on-off valve and the expansion valve. The branch pipe and the gas side pipe of the heat storage heat exchanger can be connected via a second on-off valve. In this case as well, four patterns of operation can be performed by similarly controlling the first and second on-off valves.
[0012]
Furthermore, the gas side piping of the indoor heat exchanger and the gas side piping of the heat storage heat exchanger can be connected via a third on-off valve. By opening the third on-off valve, the first and second compressors can be connected in parallel. Therefore, for example, if the first and second compressors are connected to the indoor heat exchanger, the amount of refrigerant supplied to the indoor heat exchanger can be increased, so that it is possible to cope with an excessive air conditioning load. Moreover, if it connects to a heat storage heat exchanger, the time taken to complete the heat storage can be shortened.
[0013]
Also, two outdoor heat exchangers are provided, the first compressor is connected to the gas side pipe of one outdoor heat exchanger via the cooling / heating switching valve, and the first side is connected to the gas side pipe of the other outdoor heat exchanger. Two compressors can be connected. According to this, by using an outdoor unit of a special form that has two compressors and one outdoor heat exchanger, one liquid side pipe and two gas side pipes are connected. In addition, a general-purpose outdoor unit having one compressor and one outdoor heat exchanger and having one liquid side pipe and one gas side pipe connected to each other is used to store the regenerative air conditioner of the present invention. Can be formed.
[0014]
In such a configuration including a plurality of outdoor heat exchangers, when the connected compressor is not operating, the refrigerant flows into the outdoor heat exchanger and accumulates, and the refrigerant circulation amount of the entire apparatus may change. is there. Usually, since the refrigeration cycle is designed on the assumption that a constant refrigerant circulates, there is a problem that temperature control or the like cannot be performed properly if the refrigerant circulation amount changes. Therefore, it is preferable to provide a fourth on-off valve in the liquid side piping of each outdoor heat exchanger. If this fourth valve is closed, it is possible to prevent the refrigerant from flowing from the liquid side pipe into the outdoor heat exchanger to which the compressor that is not in operation is connected, and it is possible to avoid a change in the circulation amount of the refrigerant.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
Hereinafter, a first embodiment of a heat storage type air conditioner of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a regenerative air conditioner to which the present invention is applied. The heat storage type air conditioner of this embodiment includes a heat storage heat exchanger 1, a plurality of (two in this embodiment) indoor heat exchanger 3, an outdoor heat exchanger 5, and compressors 7 and 8. Is forming. The heat storage heat exchanger 1 is formed of a meandering heat transfer tube and is disposed in the heat storage tank 11. In the heat storage tank 11, water or heat storage water 13 mainly containing water is stored, and the heat storage heat exchanger 1 is immersed in the heat storage water 13.
[0016]
The outdoor heat exchanger 5 is formed so as to exchange heat between the refrigerant flowing inside and the outside air. The outdoor heat exchanger 5 includes a liquid side pipe 15 and a gas side pipe 17. One ends of branch pipes 19 and 21 are connected to the tip of the liquid side pipe 15. The other end of the branch pipe 19 is connected to the liquid side pipe 25 of the heat storage heat exchanger 1 via the expansion valve 23. The gas side pipe 27 of the heat storage heat exchanger 1 is connected to a four-way valve 29, and the four-way valve 29 is connected to the gas side pipe 17 of the outdoor heat exchanger 5. The four-way valve 29 is configured to switch the gas side pipe 17 to either the discharge side or the suction side of the compressor 7 for communication, and to communicate the other side to the gas side pipe 27.
[0017]
The other end of the branch pipe 21 branched from the liquid side pipe 15 of the outdoor heat exchanger 5 is further branched and connected to the two expansion valves 31. Each expansion valve 31 is connected to a liquid side pipe 33 of each indoor heat exchanger 3. The gas side pipes of the indoor heat exchangers 3 are connected to each other to form one gas side pipe 35. The gas side pipe 35 is connected to a four-way valve 37, and the four-way valve 37 is connected to the gas side pipe 17 of the outdoor heat exchanger 5. The four-way valve 37 switches the gas side pipe 17 to either the discharge side or the suction side of the compressor 8 and communicates it, and communicates the other to the gas side pipe 35.
[0018]
The on-off valve 39 as the first on-off valve is provided in the liquid side pipe 15 of the outdoor heat exchanger 5. A bypass pipe 41 that connects the liquid side pipe 15 between the outdoor heat exchanger 5 and the on-off valve 39 and the gas side pipe 27 of the heat storage heat exchanger 1 is provided. The bypass pipe 41 is provided with an on-off valve 43 that is a second on-off valve. A bypass pipe 45 that connects the gas side pipe 27 between the bypass pipe 41 and the four-way valve 29 and the gas side pipe 35 of the indoor heat exchanger 3 is provided. The bypass pipe 45 is an open / close that is a third on-off valve. A valve 47 is provided. An opening / closing valve 49 is provided in a portion of the gas side pipe 27 sandwiched between the bypass pipe 41 and the bypass pipe 45.
[0019]
The heat storage tank 1, the expansion valve 23, and the on-off valves 39, 43, 47, 49 are in the heat storage unit 51, the indoor heat exchanger 3, and the expansion valve 31 are in the indoor unit 53, the outdoor heat exchanger 5, the compressor 7, 8 and the expansion valves 29 and 37 are stored in the outdoor unit 55, respectively. The opening / closing valves 39, 43, 47 and 49, the opening degrees of the expansion valves 23 and 31, the switching of the four-way valves 29 and 37, and the operating frequency of the compressors 7 and 8 are controlled by a control device (not shown). It has come to be.
[0020]
The operation mode and operation of the heat storage type air conditioner configured as described above will be described by taking cooling as an example. During this cooling, the four-way valves 29 and 37 are connected as shown by the solid line in the figure. That is, the four-way valve 29 connects the discharge side of the compressor 7 to the gas side pipe 17 of the outdoor heat exchanger 5 and connects the suction side to the gas side pipe 27 of the heat storage heat exchanger 1. The four-way valve 37 connects the discharge side of the compressor 8 to the gas side pipe 17 of the outdoor heat exchanger 5 and connects the suction side to the gas side pipe 35 of the indoor heat exchanger 3.
(Heat storage operation mode)
When performing the heat storage operation alone, the control device closes the on-off valves 43 and 47 and the expansion valve 31, opens the on-off valves 39 and 49, and appropriately adjusts the opening degree of the expansion valve 23 to drive the compressor 7. To do. As a result, the gas refrigerant compressed by the compressor 7 is led to the outdoor heat exchanger 5 through the four-way valve 29 and the gas side pipe 17 and is condensed by heat exchange with the outside air to become a liquid refrigerant. 15, through the on-off valve 39 and the branch pipe 19, and led to the expansion valve 23. The liquid refrigerant decompressed by the expansion valve 23 exchanges heat with the heat storage water 13 in the heat storage tank 11 in the heat storage heat exchanger 1 and evaporates. As a result, the temperature of the heat storage water 13 in the heat storage tank 11 is lowered, and ice is gradually formed around the heat storage heat exchanger 1. Thereafter, the evaporated gas refrigerant is returned to the suction side of the compressor 7 through the gas side pipe 27, the on-off valve 49, and the four-way valve 29 of the heat storage heat exchanger 1.
(Cooling operation mode)
When performing the cooling operation alone, the control device closes the on-off valves 43, 47, 49, and the expansion valve 23, opens the on-off valve 39, and appropriately adjusts the opening degree of the expansion valve 31, for example, refrigerant pressure or refrigerant The operating frequency of the compressor 8 is controlled according to the load of the indoor heat exchanger 3 obtained from the temperature or the like. Thereby, the gas refrigerant compressed by the compressor 8 flows into the outdoor heat exchanger 5 through the four-way valve 37 and the gas side pipe 17, and is condensed by heat exchange with the outside air to become a liquid refrigerant. The liquid refrigerant discharged from the outdoor heat exchanger 5 flows through the liquid side pipe 15, the on-off valve 39 and the branch pipe 21 and is led to the expansion valve 31. The liquid refrigerant decompressed by the expansion valve 31 evaporates by exchanging heat with indoor air in the indoor heat exchanger 3, and lowers the temperature of the indoor air. Thereafter, the evaporated gas refrigerant is returned to the suction side of the compressor 8 through the gas side pipe 35 and the four-way valve 37 of the indoor heat exchanger 3.
(Operation mode using heat storage)
When performing cooling operation using heat storage, the control device closes the on-off valves 39, 47, and 49, opens the on-off valve 43, fully opens the expansion valve 23, sets the refrigerant pressure in the indoor heat exchanger 3, The operating frequency of the compressor 8 and the opening degree of the expansion valve 31 are appropriately adjusted according to the refrigerant temperature. Thereby, the gas refrigerant compressed by the compressor 8 flows into the outdoor heat exchanger 5 through the four-way valve 37 and the gas side pipe 17 and is condensed by heat exchange with the outside air to become a liquid refrigerant. 15, flows into the heat storage heat exchanger 1 through the bypass pipe 41, the on-off valve 43, and the gas side pipe 27. When the liquid refrigerant flows through the heat storage heat exchanger 1, the liquid refrigerant is cooled by the cold energy stored in the heat storage water 13. The cooled liquid refrigerant is guided to the indoor heat exchanger 3 through the branch pipes 19 and 21 and the expansion valve 31. As a result, the degree of supercooling of the liquid refrigerant increases, and the amount of cold heat corresponding to that can be used for cooling indoor air. Thereafter, the refrigerant evaporated in the indoor heat exchanger 3 is returned to the suction side of the compressor 8 through the gas side pipe 35 and the four-way valve 37 of the indoor heat exchanger 3.
[0021]
Further, in the heat storage operation, the cooling operation, and the heat storage utilization operation, the compressors 7 and 8 can be connected in parallel and operated by opening the on-off valve 47. According to this, according to the load of the heat storage heat exchanger 1 or the indoor heat exchanger 3, for example, when the load is small, the number of operating units can be reduced, and the operating efficiency can be improved.
(Parallel operation mode)
Next, the case of performing parallel operation in which heat storage and cooling are performed at the same time, which is a characteristic part of the present embodiment, will be described. First, the control device closes the on-off valves 43 and 47, opens the on-off valves 39 and 49, and adjusts the opening degree of the expansion valves 23 and 31 as appropriate. And while adjusting the operating frequency of the compressor 7 according to the load of the heat storage heat exchanger 1, the operating frequency of the compressor 8 is adjusted according to the load of the indoor heat exchanger 3. As a result, the gas refrigerant compressed by the compressor 8 merges with the gas refrigerant compressed by the compressor 7 in the gas side pipe 17, condensed in the outdoor heat exchanger 5, and partly led to the expansion valve 23. The remaining refrigerant is guided to the expansion valve 31. The refrigerant guided to the expansion valve 23 evaporates in the heat storage heat exchanger 1 and returns to the compressor 7 in the same manner as in the heat storage operation described above. On the other hand, the refrigerant guided to the expansion valve 31 evaporates in the indoor heat exchanger 3 and returns to the compressor 8 as in the above-described cooling operation.
[0022]
Thus, according to this embodiment, since the refrigerant | coolant of the heat storage heat exchanger 1 and the refrigerant | coolant of the indoor heat exchanger 3 can be suck | inhaled by a separate compressor, the heat storage heat exchanger 1 and the indoor heat exchanger 3 differ. For example, even if ice in the heat storage tank 11 grows and the suction pressure of the compressor 7 decreases, the respective refrigerant pressures can be maintained appropriately. Therefore, since the valve provided on the gas side of the indoor heat exchanger can be omitted in order to adjust the refrigerant pressure of the indoor heat exchanger, the energy efficiency can be improved by the amount of pressure loss due to the valve. That is, it is possible to simultaneously perform the heat storage operation and the air conditioning operation and improve the energy efficiency. Furthermore, since each compressor can be driven according to the load concerning the heat storage heat exchanger 1 and the indoor heat exchanger 3, an efficient driving | operation can be performed.
[0023]
Further, in the present embodiment, the cooling operation has been described as an example. However, in the case of performing the heating operation, the four-way valves 29 and 37 are connected as indicated by dotted lines in the drawing. That is, the four-way valve 29 connects the discharge side of the compressor 7 to the gas side pipe 27 of the heat storage heat exchanger 1 and connects the suction side to the gas side pipe 17 of the outdoor heat exchanger 5. The four-way valve 37 connects the discharge side of the compressor 8 to the gas side pipe 35 of the indoor heat exchanger 3 and connects the suction side to the gas side pipe 17 of the outdoor heat exchanger 5. In this case, the refrigerant circulation direction is reversed.
(Second Embodiment)
FIG. 2 shows a schematic configuration of the second embodiment of the heat storage type air conditioner according to the present invention. This embodiment is different from the above embodiment in that two outdoor heat exchangers 5 are provided and connected to the compressors 7 and 8, respectively. Accordingly, the same components as those in the above embodiment are denoted by the same reference numerals and description thereof is omitted.
[0024]
Specifically, the heat storage type air conditioner of this embodiment includes outdoor heat exchangers 5A and 5B, the gas side pipe 27 of the heat storage heat exchanger 1 is connected to a four-way valve 29, and the four-way valve 29 is an outdoor heat. Connected to the gas side pipe 17A of the exchanger 5A, the gas side pipe 17A is switched to either the discharge side or the suction side of the compressor 7 so as to communicate therewith, and the other is communicated to the gas side pipe 27. Yes. The gas side pipe 35 of the indoor heat exchanger 3 is connected to a four-way valve 37, and the four-way valve 37 is connected to the gas side pipe 17 B of the outdoor heat exchanger 5 B, and the gas side pipe 17 B is discharged from the compressor 8. The side is switched to either the suction side or the suction side, and the other side is communicated with the gas side pipe 35. In addition, on the liquid side pipes of the outdoor heat exchangers 5A and 5B, on-off valves 61 and 63, which are fourth on-off valves, are provided, respectively. The liquid side pipes of the outdoor heat exchangers 5A and 5B are connected to each other to form one liquid side pipe 15. The outdoor unit 55 includes two subunits 57 and 59. The subunit 57 stores the compressor 7, the four-way valve 29, and the outdoor heat exchanger 5A, and the subunit 59 stores the compressor 8, the four-way valve 37, and the outdoor heat exchanger 5B.
[0025]
As described above, according to the present embodiment, one compressor or a plurality of compressors connected in parallel and one outdoor heat exchanger, for example, has one liquid-side pipe and one gas. It is preferable because a heat storage type air conditioner can be formed with general-purpose outdoor units (sub units 57 and 59) to which side pipes are connected. Further, by providing the on-off valves 61 and 63, when the subunit is not operated, the refrigerant can be prevented from flowing into the stopped subunit from the liquid side pipe 15, and the refrigerant circulation amount of the entire apparatus is reduced. You can avoid that.
[0026]
Further, in the present embodiment, the on-off valves 61 and 63 are provided in the piping in the outdoor unit, but can also be provided in the piping in the heat storage unit as shown in FIG. In this way, power can be easily supplied to the on-off valves 61 and 63 by being arranged in any unit. Moreover, you may provide not only in this but in the liquid side piping which connects an outdoor unit and a thermal storage unit, for example. Further, in the present embodiment, the configuration of two subunits is shown, but not limited to this, a plurality of subunits may be arranged in parallel.
[0027]
【The invention's effect】
As described above, according to the present invention, the heat storage operation and the cooling / heating operation can be performed simultaneously, and the energy efficiency can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a first embodiment of a regenerative air conditioner to which the present invention is applied.
FIG. 2 is a schematic configuration diagram of a second embodiment of a heat storage type air conditioner to which the present invention is applied.
FIG. 3 is a schematic configuration diagram of a modified example of the second embodiment of the heat storage type air conditioner to which the present invention is applied.
[Explanation of symbols]
1 heat storage heat exchanger 3 indoor heat exchanger 5 outdoor heat exchangers 7 and 8 Compressor
