JP3623090B2

JP3623090B2 - Control device for refrigeration cycle having injection function

Info

Publication number: JP3623090B2
Application number: JP33650297A
Authority: JP
Inventors: 雄一薬丸; 正廣新; 伸二渡辺; 成人山口
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 1997-11-20
Filing date: 1997-11-20
Publication date: 2005-02-23
Anticipated expiration: 2017-11-20
Also published as: JPH11153363A

Description

【０００１】
【発明の属する技術分野】
本発明は、気液分離器を備え、この気液分離器で分離した後のガス成分を、運転状態に応じて、圧縮機にインジェクションするようにした冷凍サイクル装置に関する。
【０００２】
【従来の技術】
従来からインジェクションを行うことにより、圧縮機の入力を増加させることが行われており、例えば特開平５ー６０４０２号公報には、除霜運転中にインジェクションを行う冷凍サイクル装置が示されている。
同公報に記載の技術は、蒸発器の除霜を高圧ガス冷媒にて行う場合に、インジェクションを行うための冷媒が不足することを防止し、液インジェクションを安定して行い、圧縮機の冷却を確実に行うことを目的になされたものである。
【０００３】
【発明が解決しようとする課題】
しかし、インジェクションを行うことは、圧縮機の入力を高める一方で、圧縮機の温度を低下させるため、除霜運転時に、圧縮機の吐出温度が必要以上に低下してしまうと、暖房運転の立ち上がり性能が低下してしまうという課題を有してしまう。
【０００４】
そこで本発明は、インジェクションする冷媒量や冷媒状態を運転状態に応じて制御できるインジェクション機能を有する冷凍サイクルの制御装置を提供することを目的とする。
また本発明は、除霜運転時間を短縮するとともに、除霜運転終了後の暖房運転立ち上がり性能を高めることのできるインジェクション機能を有する冷凍サイクルの制御装置を提供することを目的とする。
【０００５】
【課題を解決するための手段】
本発明の請求項１記載のインジェクション機能を有する冷凍サイクルの制御装置は、圧縮機、四方弁、室外熱交換器、第一の減圧装置、気液分離器、第二の減圧装置、室内熱交換器を配管によってそれぞれ順に環状に接続し、前記気液分離器と前記圧縮機とをガスインジェクション用配管で接続した冷凍サイクル装置において、前記第一の減圧装置及び前記第二の減圧装置を弁開度可変の減圧装置とし、前記第一の減圧装置及び前記第二の減圧装置の弁開度を冷凍サイクルの運転状態に応じて変更し、前記四方弁の切り換えによって、前記圧縮機から吐出された冷媒を、前記室外熱交換器、前記第一の減圧装置、前記気液分離器、前記第二の減圧装置、前記室内熱交換器にそれぞれ順に流す除霜運転時に、前記第一の減圧装置の弁開度を７３％以上に開いてガスインジェクションを行うことを特徴とする。
本発明の請求項２記載のインジェクション機能を有する冷凍サイクルの制御装置は、請求項１に記載のインジェクション機能を有する冷凍サイクルの制御装置において、除霜運転時に、前記第二の減圧装置の弁開度を７３％以下に絞ってガスインジェクションを行うことを特徴とする。
本発明の請求項３記載のインジェクション機能を有する冷凍サイクルの制御装置は、圧縮機、四方弁、室外熱交換器、第一の減圧装置、気液分離器、第二の減圧装置、室内熱交換器を配管によってそれぞれ順に環状に接続し、前記気液分離器と前記圧縮機とをガスインジェクション用配管で接続した冷凍サイクル装置において、前記第一の減圧装置及び前記第二の減圧装置を弁開度可変の減圧装置とし、前記第一の減圧装置及び前記第二の減圧装置の弁開度を冷凍サイクルの運転状態に応じて変更し、前記四方弁の切り換えによって、前記圧縮機から吐出された冷媒を、前記室外熱交換器、前記第一の減圧装置、前記気液分離器、前記第二の減圧装置、前記室内熱交換器にそれぞれ順に流す除霜運転を終了した後、暖房運転再開後の所定時間は前記第二の減圧装置の弁開度を７３％以下に絞ってガスインジェクションを行い、その後前記第二の減圧装置の弁開度を前記所定時間内の弁開度よりも開いてガスインジェクションを行うことを特徴とする。
本発明の請求項４記載のインジェクション機能を有する冷凍サイクルの制御装置は、請求項１に記載のインジェクション機能を有する冷凍サイクルの制御装置において、除霜運転終了前の所定時間、前記第一の減圧装置の弁開度を７３％以下に絞ってガスインジェクションを行うことを特徴とする。
本発明の請求項５記載のインジェクション機能を有する冷凍サイクルの制御装置は、圧縮機、四方弁、室外熱交換器、減圧装置、気液分離器、室内熱交換器を配管によって環状に接続し、前記気液分離器と前記圧縮機とをガスインジェクション用配管で接続した冷凍サイクル装置において、冷媒としてＲ４１０Ａを用い、前記四方弁の切り換えによって、前記圧縮機から吐出された冷媒を、前記室外熱交換器、前記第一の減圧装置、前記気液分離器、前記第二の減圧装置、前記室内熱交換器にそれぞれ順に流す除霜運転終了後の暖房運転時、圧縮機の吐出温度が所定値以上になったときにガスインジェクションを行うことを特徴とする。
本発明の請求項６記載のインジェクション機能を有する冷凍サイクルの制御装置は、圧縮機、四方弁、室外熱交換器、減圧装置、気液分離器、室内熱交換器を配管によって環状に接続し、前記気液分離器と前記圧縮機とをガスインジェクション用配管で接続した冷凍サイクル装置において、冷媒としてＲ４１０Ａを用い、前記四方弁の切り換えによって、前記圧縮機から吐出された冷媒を、前記室外熱交換器、前記第一の減圧装置、前記気液分離器、前記第二の減圧装置、前記室内熱交換器にそれぞれ順に流す除霜運転終了後の暖房運転時、暖房運転再開からの所定時間経過後にガスインジェクションを行うことを特徴とする。
本発明の請求項７記載のインジェクション機能を有する冷凍サイクルの制御装置は、圧縮機、四方弁、室外熱交換器、減圧装置、気液分離器、室内熱交換器を配管によって環状に接続し、前記気液分離器と前記圧縮機とをガスインジェクション用配管で接続した冷凍サイクル装置において、冷媒としてＲ４１０Ａを用い、前記四方弁の切り換えによって、前記圧縮機から吐出された冷媒を、前記室外熱交換器、前記第一の減圧装置、前記気液分離器、前記第二の減圧装置、前記室内熱交換器にそれぞれ順に流す除霜運転終了前の所定時間、ガスインジェクションを行わないことを特徴とする。
本発明の請求項８記載のインジェクション機能を有する冷凍サイクルの制御装置は、請求項１から請求項４のいずれかに記載のインジェクション機能を有する冷凍サイクルの制御装置において、冷媒としてＲ４１０Ａを用いたことを特徴とする。
【０００６】
【発明の実施の形態】
本発明の第１の実施の形態は、第一の減圧装置及び第二の減圧装置を弁開度可変の減圧装置とし、これらの減圧装置の弁開度を冷凍サイクルの運転状態に応じて変更し、四方弁の切り換えによって、圧縮機から吐出された冷媒を、室外熱交換器、第一の減圧装置、気液分離器、第二の減圧装置、室内熱交換器にそれぞれ順に流す除霜運転時に、第一の減圧装置の弁開度を７３％以上に開いてガスインジェクションを行うものである。この実施の形態によれば、気液分離器の前後に配置したそれぞれの減圧装置の弁開度を制御することで、気液分離器内に貯留される冷媒状態やガスインジェクション用配管を流れる冷媒量を制御することができる。従って、運転状態に応じてインジェクションする冷媒量や、冷媒の状態を制御できるため、除霜運転時間を短縮したり、除霜運転を終了した後の暖房運転の立ち上がり性能を高めたりすることができる。また、インジェクションの量を増加させることができるので、圧縮機の入力を高めることができる。従って、除霜運転時間を短縮することができ、省エネを実現することができる。
【０００７】
本発明の第２の実施の形態は、第１の実施形態において、除霜運転時に、第二の減圧装置の弁開度を７３％以下に絞るものである。この実施の形態によれば、気液分離器内に貯留する冷媒量が増加するため、インジェクションされる冷媒は、液リッチの冷媒となる。従って、圧縮機の入力を増加させることができ、除霜運転時間を短縮することができる。
【０００８】
本発明の第３の実施の形態は、第一の減圧装置及び第二の減圧装置を弁開度可変の減圧装置とし、第一の減圧装置及び第二の減圧装置の弁開度を冷凍サイクルの運転状態に応じて変更し、四方弁の切り換えによって、圧縮機から吐出された冷媒を、室外熱交換器、第一の減圧装置、気液分離器、第二の減圧装置、室内熱交換器にそれぞれ順に流す除霜運転を終了した後、暖房運転再開後の所定時間は第二の減圧装置の弁開度を７３％以下に絞ってガスインジェクションを行い、その後第二の減圧装置の弁開度を所定時間内の弁開度よりも開いてガスインジェクションを行うものである。この実施の形態によれば、暖房運転再開後の所定時間は、インジェクション量を少なくすることができる。従って、圧縮機内の大幅な温度低下を防ぐとともに、蒸発器のエンタルピを増加させることができ、暖房性能の向上を図ることができる。
【０００９】
本発明の第４の実施の形態は、第１の実施形態において、除霜運転終了前の所定時間、第一の減圧装置の弁開度を７３％以下に絞ってガスインジェクションを行うものである。この実施の形態によれば、除霜運転終了前の所定時間、インジェクション量を減少させるので、除霜運転終了時点での圧縮機内の大幅な温度低下を防止することができる。従って、暖房運転再開後の立ち上がり特性を高めることができる。なお、除霜運転終了前にインジェクション量を減少させても除霜運転時間に大きな影響を与えることはない。すなわち、通常除霜運転は、室外熱交換器である蒸発器の着霜を完全に除去するまで行う。一部に霜が残った状態では、暖房運転復帰後の霜の成長が早いために除霜運転の間隔が短くなってしまうためである。しかし、この部分的に残った霜は、既に蒸発器に与えられている熱の着霜部分への伝導によって十分除去が可能である反面、着霜部分への熱伝導が行われない限り、十分な除去は行えない。従って、圧縮機能力を高めたとしても熱伝導のための所定時間は必ず必要となり、導入する高温ガス量を増加させても部分的に残った霜の除去時間を大きく短縮することはできないためである。
【００１０】
本発明の第５の実施の形態は、冷媒としてＲ４１０Ａを用い、四方弁の切り換えによって、圧縮機から吐出された冷媒を、室外熱交換器、第一の減圧装置、気液分離器、第二の減圧装置、室内熱交換器にそれぞれ順に流す除霜運転終了後の暖房運転時、圧縮機の吐出温度が所定値以上になったときにガスインジェクションを行うものである。この実施の形態によれば、圧縮機の吐出温度が低いときには、ガスインジェクションを行わないため、圧縮機内の温度上昇を早くすることができ、暖房運転再開後の立ち上がり性能を向上させることができる。
【００１１】
本発明の第６の実施の形態は、冷媒としてＲ４１０Ａを用い、四方弁の切り換えによって、圧縮機から吐出された冷媒を、室外熱交換器、第一の減圧装置、気液分離器、第二の減圧装置、室内熱交換器にそれぞれ順に流す除霜運転終了後の暖房運転時、暖房運転再開からの所定時間経過後にガスインジェクションを行うものである。この実施の形態も第６の実施の形態と同様の作用により、暖房運転再開後の立ち上がり性能を向上させることができる。なお、この実施の形態によれば、圧縮機の吐出温度を検知することなく制御するため、簡便に行うことができる。
【００１２】
本発明の第７の実施の形態は、冷媒としてＲ４１０Ａを用い、四方弁の切り換えによって、圧縮機から吐出された冷媒を、室外熱交換器、第一の減圧装置、気液分離器、第二の減圧装置、室内熱交換器にそれぞれ順に流す除霜運転終了前の所定時間、ガスインジェクションを行わないものである。この実施の形態によれば、除霜運転終了前の所定時間、インジェクションを行わないので、除霜運転終了時点での圧縮機内の大幅な温度低下を防止することができる。従って、暖房運転再開後の立ち上がり特性を高めることができる。なお、除霜運転終了前にインジェクションを行わなくても除霜運転時間に大きな影響を与えることはないことは、上記第５の実施の形態で説明した通りであり、圧縮機能力を高めたとしても熱伝導のための所定時間は必ず必要となり、導入する高温ガス量を増加させても部分的に残った霜の除去時間を大きく短縮することはできないためである。
【００１３】
本発明の第８の実施の形態は、第１から第４の実施の形態において、冷媒としてＲ４１０Ａを用いたものである。Ｒ４１０Ａは、例えば現在一般に用いられているＲ２２冷媒と比較すると圧力損失は小さい。従って、冷媒として、Ｒ４１０Ａを用いることによって、減圧装置をさらに絞ることができ、冷凍能力を高めることができる。また第一の減圧装置をさらに絞ることによって、蒸発器のエンタルピを増加することができる。
【００１４】
【実施例】
以下本発明の実施例について図面に基づいて説明する。
図１は本発明の一実施例における冷凍サイクル図、図２は同実施例に用いる減圧装置の流量特性図である。
図１に示すように、冷凍サイクルは、圧縮機１、四方弁２、室外熱交換器３、第一の減圧装置４、気液分離器５、第二の減圧装置６、室内熱交換器７を配管によってそれぞれ順に環状に接続している。また、気液分離器５と圧縮機１とをガスインジェクション用配管８で接続している。また、ガスインジェクション用配管８には、インジェクションのオン・オフを行うための開閉弁９が設けられている。同冷凍サイクルは、四方弁２の切り換えによって冷房・暖房・除霜運転を行う。そして、冷房又は除霜運転時には、室外熱交換器３は凝縮器として、室内熱交換器７は蒸発器として使用される。また、暖房運転時には、室外熱交換器３は蒸発器として、室内熱交換器７は凝縮器として使用される。
【００１５】
ここで、第一の減圧装置４及び第二の減圧装置６は、弁開度可変の減圧装置を用いている。これら第一の減圧装置４及び第二の減圧装置６の流量特性を図２に示す。同図に示すように、弁は０パルスで閉状態となり、５００パルスで全開状態となる。なお全開状態では絞り量は０である。３５０パルス（７３％の弁開度）を越えると、冷媒は流れやすくなり流量は増加する。すなわち減圧作用は低下する。
【００１６】
次に、図１をもとに運転状態に応じた制御方法及びその時の冷媒の流れについて説明する。
同図の配管接続状態、及び矢印の冷媒流れは、冷房又は除霜運転時を示している。
まず、通常の冷房又は除霜運転時には、図示のように、圧縮機１から吐出された冷媒は、室外熱交換器３、第一の減圧装置４、気液分離器５、第二の減圧装置６、室内熱交換器７を経由して圧縮機１に戻される。この時、開閉弁９を開くことにより、気液分離器５で分離されたガス冷媒は、ガスインジェクション用配管８を通って圧縮機１に導入される。
ここで、第一の減圧装置４の弁開度を大きくすると気液分離器５に導入される冷媒量は増加するために、ガスインジェクション用配管８を流れる冷媒量は増加する。逆に第一の減圧装置４の弁開度を小さくすると気液分離器５に導入される冷媒量は減少するために、ガスインジェクション用配管８を流れる冷媒量は減少する。また、第二の減圧装置６の弁開度を小さくすると気液分離器５に貯留される冷媒量が増加するために、ガスインジェクション用配管８を流れる冷媒は液リッチの冷媒となる。逆に第二の減圧装置６の弁開度を大きくすると気液分離器５に貯留される冷媒量が減少するために、ガスインジェクション用配管８を流れる冷媒はガスリッチの冷媒となる。
【００１７】
次に、暖房運転時の冷媒の流れについて説明する。この時、四方弁２と気液分離器５での接続は点線で示すように切り換えられる。
従って、圧縮機１から吐出された冷媒は、室内熱交換器７、第二の減圧装置６、気液分離器５、第一の減圧装置４、室外熱交換器３を経由して圧縮機１に戻される。この時、開閉弁９を開くことにより、気液分離器５で分離されたガス冷媒は、ガスインジェクション用配管８を通って圧縮機１に導入される。
【００１８】
ここで、上記のような暖房運転の状態から、除霜運転に切り換えた場合について説明する。四方弁２及び気液分離器５の接続は、実線で示す状態に切り換えられる。
この時、開閉弁９は開としてガスインジェクションを行う。また第一の減圧装置４の弁開度を全開とする。このように第一の減圧装置４の弁開度を全開とすることによって、除霜運転時の圧縮機入力を増加させることができる。また、第二の減圧装置６の弁開度を絞ることによって前述の通り液リッチの冷媒をインジェクションすることができるのでさらに圧縮機入力を増加させることができる。
このようにして除霜運転時間を短縮することができる。なお、第一の減圧装置４は、必ずしも全開である必要はなく、図２の流量特性から、全開に対して７３％以上の弁開度が好ましい。また第二の減圧装置６については７３％以下に絞るものとすれば絞り効果が高く好ましい。
【００１９】
上記の状態で除霜運転を行うが、除霜運転終了前に開閉弁９を閉としてインジェクションをオフとする。このインジェクションオフから除霜運転終了までの所定時間は約１５秒から３０秒程度である。
このように、除霜運転終了前の所定時間、インジェクションを行わないことで、除霜運転終了時点での圧縮機内の大幅な温度低下を防止することができる。従って、暖房運転再開後の立ち上がり特性を高めることができる。なお、除霜運転終了前にインジェクションを行わなくても除霜運転時間に大きな影響を与えることはない。すなわち、除霜運転は、一部に霜が残った状態では、暖房運転復帰後の霜の成長が早いために除霜運転の間隔が短くなってしまうため、室外熱交換器である蒸発器の着霜を完全に除去するまで行う。しかし、この部分的に残った霜は、既に蒸発器に与えられている熱の着霜部分への伝導によって十分除去が可能である反面、着霜部分への熱伝導が行われない限り、十分な除去は行えない。従って、圧縮機能力を高めたとしても熱伝導のための所定時間は必ず必要となり、導入する高温ガス量を増加させても部分的に残った霜の除去時間を大きく短縮することはできないためである。
上記の場合には、除霜運転終了前の所定時間、インジェクションを行わない場合で説明したが、第一の減圧装置の弁開度を７３％以下に絞ってガスインジェクションを行うようにしてもよい。この場合にもインジェクション量を減少させるので、除霜運転終了時点での圧縮機内の大幅な温度低下を防止することができる。
【００２０】
次に、除霜運転終了後の暖房運転再開時の運転状態について説明する。
まず、前述のように四方弁２を点線のように切り換えて暖房運転を行う。この時、開閉弁９を閉として、インジェクションをオフとする。そしてインジェクションをオフの状態で所定時間運転した後に、インジェクションをオンとする。この時の所定時間は、約５分程度である。なお、所定時間をあらかじめ決めた時間としてもよいが、圧縮機１の吐出温度を検知して、吐出温度が所定値以上になったことを検知したときに、インジェクションをオンとするものであってもよい。この場合には、圧縮機１の正確な状態に基づいて制御することができるので、暖房立ち上がり性能をより向上させることができる。
なお、インジェクションを完全にオフとする場合の他、第二の減圧装置６を７３％以下に絞ることによってインジェクションされる冷媒量を減少させてもよい。
【００２１】
上記の冷凍サイクルに冷媒としてＲ４１０Ａを用いるとさらに効果的である。Ｒ４１０Ａは、例えば現在一般に用いられているＲ２２冷媒と比較すると圧力損失は小さい。従って、冷房・除霜運転時には第一の減圧装置４を、暖房運転時には第二の減圧装置６をさらに絞ることによって、蒸発器のエンタルピを増加することができる。
【００２２】
【発明の効果】
以上説明から明らかなように、本発明は、気液分離器の前後に配置したそれぞれの減圧装置の弁開度を制御することで、気液分離器内に貯留される冷媒状態やガスインジェクション用配管を流れる冷媒量を制御することができる。従って、運転状態に応じてインジェクションする冷媒量や、冷媒の状態を制御できるため、除霜運転時間を短縮したり、除霜運転を終了した後の暖房運転の立ち上がり性能を高めたりすることができる。
【図面の簡単な説明】
【図１】本発明の一実施例による冷凍サイクル図
【図２】同実施例による減圧装置の流量特性図
【符号の説明】
１圧縮機
２四方弁
３凝縮器
４第一の減圧装置
５気液分離器
６第二の減圧装置
７蒸発器
８ガスインジェクション用配管
９開閉弁[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refrigeration cycle apparatus including a gas-liquid separator and injecting a gas component separated by the gas-liquid separator into a compressor according to an operating state.
[0002]
[Prior art]
Conventionally, injection is performed by increasing the input of the compressor. For example, Japanese Patent Laid-Open No. 5-60402 discloses a refrigeration cycle apparatus that performs injection during a defrosting operation.
The technology described in this publication prevents a shortage of refrigerant for performing injection when performing defrosting of the evaporator with a high-pressure gas refrigerant, stably performing liquid injection, and cooling the compressor. It was made for the purpose of ensuring.
[0003]
[Problems to be solved by the invention]
However, the injection increases the input of the compressor while lowering the temperature of the compressor. Therefore, when the discharge temperature of the compressor decreases more than necessary during the defrosting operation, the heating operation starts. It has the subject that performance will fall.
[0004]
Then, an object of this invention is to provide the control apparatus of the refrigerating cycle which has an injection function which can control the refrigerant | coolant amount and refrigerant | coolant state to inject according to an operating state.
Another object of the present invention is to provide a control apparatus for a refrigeration cycle having an injection function capable of shortening the defrosting operation time and enhancing the heating operation start-up performance after the completion of the defrosting operation.
[0005]
[Means for Solving the Problems]
The control apparatus for a refrigeration cycle having an injection function according to claim 1 of the present invention includes a compressor, a four-way valve, an outdoor heat exchanger, a first decompression device, a gas-liquid separator, a second decompression device, and an indoor heat exchange. In the refrigeration cycle apparatus, in which the gas-liquid separator and the compressor are connected by a pipe for gas injection, the first decompressor and the second decompressor are opened. The valve opening degree of the first pressure reducing device and the second pressure reducing device is changed according to the operating state of the refrigeration cycle, and discharged from the compressor by switching the four-way valve. During the defrosting operation in which the refrigerant flows through the outdoor heat exchanger, the first pressure reducing device, the gas-liquid separator, the second pressure reducing device, and the indoor heat exchanger in order, the first pressure reducing device Set the valve opening to 73 And performing gas injection opening above.
The control apparatus for a refrigeration cycle having an injection function according to claim 2 of the present invention is the control apparatus for a refrigeration cycle having an injection function according to claim 1 , wherein the valve opening of the second decompression device is opened during the defrosting operation. The gas injection is performed by reducing the degree to 73% or less.
A control apparatus for a refrigeration cycle having an injection function according to claim 3 of the present invention includes a compressor, a four-way valve, an outdoor heat exchanger, a first decompression device, a gas-liquid separator, a second decompression device, and an indoor heat exchange. In the refrigeration cycle apparatus, in which the gas-liquid separator and the compressor are connected by a pipe for gas injection, the first decompressor and the second decompressor are opened. The valve opening degree of the first pressure reducing device and the second pressure reducing device is changed according to the operating state of the refrigeration cycle, and discharged from the compressor by switching the four-way valve. After completing the defrosting operation in which the refrigerant flows through the outdoor heat exchanger, the first pressure reducing device, the gas-liquid separator, the second pressure reducing device, and the indoor heat exchanger in this order, and then restarting the heating operation Predetermined time Gas injection is performed by reducing the valve opening of the second pressure reducing device to 73% or less, and then performing gas injection by opening the valve opening of the second pressure reducing device beyond the valve opening within the predetermined time. It is characterized by that.
The control apparatus for a refrigeration cycle having an injection function according to claim 4 of the present invention is the control apparatus for a refrigeration cycle having an injection function according to claim 1 , wherein the first depressurization is performed for a predetermined time before the end of the defrosting operation. Gas injection is performed by restricting the valve opening of the apparatus to 73% or less.
A control device for a refrigeration cycle having an injection function according to claim 5 of the present invention comprises a compressor, a four-way valve, an outdoor heat exchanger, a pressure reducing device, a gas-liquid separator, and an indoor heat exchanger connected in a ring shape by piping, In the refrigeration cycle apparatus in which the gas-liquid separator and the compressor are connected by a gas injection pipe, R410A is used as a refrigerant, and the refrigerant discharged from the compressor is switched to the outdoor heat exchange by switching the four-way valve. The discharge temperature of the compressor is equal to or higher than a predetermined value during the heating operation after completion of the defrosting operation in which each of the first depressurizing device, the gas-liquid separator, the second depressurizing device, and the indoor heat exchanger is sequentially flowed to the indoor heat exchanger. It is characterized in that gas injection is performed when
A control device for a refrigeration cycle having an injection function as set forth in claim 6 of the present invention comprises a compressor, a four-way valve, an outdoor heat exchanger, a decompression device, a gas-liquid separator, and an indoor heat exchanger connected in a ring shape by piping, In the refrigeration cycle apparatus in which the gas-liquid separator and the compressor are connected by a gas injection pipe, R410A is used as a refrigerant, and the refrigerant discharged from the compressor is exchanged by the outdoor heat exchange by switching the four-way valve. , The first pressure reducing device, the gas-liquid separator, the second pressure reducing device, and the indoor heat exchanger, which are sequentially supplied to the indoor heat exchanger, during the heating operation after completion of the defrosting operation, after the elapse of a predetermined time from the resumption of the heating operation Gas injection is performed.
A control device for a refrigeration cycle having an injection function according to claim 7 of the present invention comprises a compressor, a four-way valve, an outdoor heat exchanger, a decompression device, a gas-liquid separator, and an indoor heat exchanger connected in a ring shape by piping, In the refrigeration cycle apparatus in which the gas-liquid separator and the compressor are connected by a gas injection pipe, R410A is used as a refrigerant, and the refrigerant discharged from the compressor is exchanged by the outdoor heat exchange by switching the four-way valve. Gas injection is not performed for a predetermined time before the end of the defrosting operation , which is sequentially flowed to the heat exchanger, the first pressure reducing device, the gas-liquid separator, the second pressure reducing device, and the indoor heat exchanger, respectively. .
The control apparatus for a refrigeration cycle having an injection function according to claim 8 of the present invention uses R410A as a refrigerant in the control apparatus for a refrigeration cycle having an injection function according to any one of claims 1 to 4. It is characterized by.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
In the first embodiment of the present invention, the first decompression device and the second decompression device are variable decompression devices, and the valve openings of these decompression devices are changed according to the operating state of the refrigeration cycle. The defrosting operation allows the refrigerant discharged from the compressor to flow through the outdoor heat exchanger, the first pressure reducing device, the gas-liquid separator, the second pressure reducing device, and the indoor heat exchanger in this order by switching the four-way valve. Sometimes the gas opening is performed with the valve opening of the first pressure reducing device opened to 73% or more . According to this embodiment, the refrigerant state stored in the gas-liquid separator and the refrigerant flowing through the gas injection pipe are controlled by controlling the valve opening degree of each decompression device arranged before and after the gas-liquid separator. The amount can be controlled. Therefore, since the amount of refrigerant to be injected and the state of the refrigerant can be controlled according to the operating state, the defrosting operation time can be shortened or the start-up performance of the heating operation after finishing the defrosting operation can be improved. . Further, since the amount of injection can be increased, the input of the compressor can be increased. Therefore, the defrosting operation time can be shortened and energy saving can be realized.
[0007]
The 2nd Embodiment of this invention restrict | squeezes the valve opening degree of a 2nd decompression device to 73% or less at the time of a defrost operation in 1st Embodiment. According to this embodiment, since the amount of refrigerant stored in the gas-liquid separator increases, the injected refrigerant becomes a liquid-rich refrigerant. Therefore, the input of the compressor can be increased and the defrosting operation time can be shortened.
[0008]
In the third embodiment of the present invention, the first pressure reducing device and the second pressure reducing device are variable pressure reducing devices, and the valve opening degrees of the first pressure reducing device and the second pressure reducing device are set to the refrigeration cycle. The refrigerant discharged from the compressor by changing the four-way valve is changed according to the operation state of the outdoor heat exchanger, the first pressure reducing device, the gas-liquid separator, the second pressure reducing device, the indoor heat exchanger. After the defrosting operation to flow in order is completed, gas injection is performed with the valve opening of the second pressure reducing device being reduced to 73% or less for a predetermined time after the heating operation is resumed, and then the valve opening of the second pressure reducing device is opened. The gas injection is performed with the degree opened more than the valve opening within a predetermined time. According to this embodiment, the injection amount can be reduced for a predetermined time after resuming the heating operation. Therefore, it is possible to prevent a significant temperature drop in the compressor, increase the enthalpy of the evaporator, and improve the heating performance.
[0009]
In the first embodiment, the fourth embodiment of the present invention performs gas injection by restricting the valve opening of the first pressure reducing device to 73% or less for a predetermined time before the end of the defrosting operation. . According to this embodiment, since the injection amount is reduced for a predetermined time before the end of the defrosting operation, a significant temperature drop in the compressor at the end of the defrosting operation can be prevented. Accordingly, it is possible to improve the rising characteristics after resuming the heating operation. Note that even if the injection amount is decreased before the defrosting operation is completed, the defrosting operation time is not greatly affected. That is, the normal defrosting operation is performed until the frost formation of the evaporator which is the outdoor heat exchanger is completely removed. This is because, in a state where frost remains in part, the frost grows quickly after returning to the heating operation, so that the interval between the defrosting operations is shortened. However, this partially remaining frost can be sufficiently removed by the conduction of heat already applied to the evaporator to the frosted part, but it is sufficient unless heat conduction to the frosted part is performed. Cannot be removed. Therefore, even if the compression function is increased, a predetermined time for heat conduction is always required, and even if the amount of high-temperature gas introduced is increased, the time for removing partially remaining frost cannot be greatly shortened. is there.
[0010]
In the fifth embodiment of the present invention, R410A is used as the refrigerant, and the refrigerant discharged from the compressor by switching the four-way valve is converted into the outdoor heat exchanger, the first pressure reducing device, the gas-liquid separator, the second The gas injection is performed when the discharge temperature of the compressor becomes a predetermined value or higher during the heating operation after the defrosting operation that sequentially flows through the decompression device and the indoor heat exchanger . According to this embodiment, since gas injection is not performed when the discharge temperature of the compressor is low, the temperature rise in the compressor can be accelerated, and the startup performance after resuming the heating operation can be improved.
[0011]
In the sixth embodiment of the present invention, R410A is used as the refrigerant, and the refrigerant discharged from the compressor by switching the four-way valve is converted into the outdoor heat exchanger, the first pressure reducing device, the gas-liquid separator, the second During the heating operation after completion of the defrosting operation, the gas injection is performed after elapse of a predetermined time from the resumption of the heating operation. This embodiment can also improve the stand-up performance after resuming the heating operation by the same operation as that of the sixth embodiment. In addition, according to this embodiment, since it controls without detecting the discharge temperature of a compressor, it can carry out simply.
[0012]
The seventh embodiment of the present invention uses R410A as the refrigerant, and converts the refrigerant discharged from the compressor by switching the four-way valve into the outdoor heat exchanger, the first pressure reducing device, the gas-liquid separator, the second The gas injection is not performed for a predetermined time before the defrosting operation , which is sequentially flowed through the decompression device and the indoor heat exchanger . According to this embodiment, since the injection is not performed for a predetermined time before the end of the defrosting operation, a significant temperature drop in the compressor at the end of the defrosting operation can be prevented. Accordingly, it is possible to improve the rising characteristics after resuming the heating operation. It should be noted that the fact that the defrosting operation time is not greatly affected even if the injection is not performed before the end of the defrosting operation is as described in the fifth embodiment, and that the compression function is enhanced. This is because a predetermined time for heat conduction is always required, and even if the amount of high-temperature gas to be introduced is increased, the time for removing partially remaining frost cannot be greatly shortened.
[0013]
The eighth embodiment of the present invention uses R410A as a refrigerant in the first to fourth embodiments. R410A has a small pressure loss compared to, for example, the R22 refrigerant that is currently generally used. Therefore, by using R410A as the refrigerant, the decompression device can be further throttled and the refrigerating capacity can be increased. Further, the enthalpy of the evaporator can be increased by further restricting the first pressure reducing device.
[0014]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a refrigeration cycle diagram in one embodiment of the present invention, and FIG. 2 is a flow characteristic diagram of a decompression device used in the embodiment.
As shown in FIG. 1, the refrigeration cycle includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, a first decompression device 4, a gas-liquid separator 5, a second decompression device 6, and an indoor heat exchanger 7. Are connected to each other in an annular manner by piping. Further, the gas-liquid separator 5 and the compressor 1 are connected by a gas injection pipe 8. Further, the gas injection pipe 8 is provided with an on-off valve 9 for turning on / off the injection. The refrigeration cycle performs cooling, heating, and defrosting operations by switching the four-way valve 2. During the cooling or defrosting operation, the outdoor heat exchanger 3 is used as a condenser, and the indoor heat exchanger 7 is used as an evaporator. In the heating operation, the outdoor heat exchanger 3 is used as an evaporator, and the indoor heat exchanger 7 is used as a condenser.
[0015]
Here, the first decompression device 4 and the second decompression device 6 use decompression devices with variable valve opening. The flow rate characteristics of the first decompressor 4 and the second decompressor 6 are shown in FIG. As shown in the figure, the valve is closed at 0 pulse and fully opened at 500 pulses. In the fully opened state, the aperture amount is zero. When 350 pulses (73% valve opening) are exceeded, the refrigerant easily flows and the flow rate increases. That is, the pressure reducing action is reduced.
[0016]
Next, based on FIG. 1, the control method according to the driving | running state and the flow of the refrigerant | coolant at that time are demonstrated.
The pipe connection state and the refrigerant flow indicated by the arrows in the same figure indicate the cooling or defrosting operation.
First, at the time of normal cooling or defrosting operation, as shown in the figure, the refrigerant discharged from the compressor 1 is the outdoor heat exchanger 3, the first decompressor 4, the gas-liquid separator 5, and the second decompressor. 6 Returned to the compressor 1 via the indoor heat exchanger 7. At this time, by opening the on-off valve 9, the gas refrigerant separated by the gas-liquid separator 5 is introduced into the compressor 1 through the gas injection pipe 8.
Here, since the amount of refrigerant introduced into the gas-liquid separator 5 increases when the valve opening degree of the first decompression device 4 is increased, the amount of refrigerant flowing through the gas injection pipe 8 increases. Conversely, if the valve opening degree of the first pressure reducing device 4 is reduced, the amount of refrigerant introduced into the gas-liquid separator 5 is reduced, so the amount of refrigerant flowing through the gas injection pipe 8 is reduced. Further, if the valve opening degree of the second decompression device 6 is reduced, the amount of refrigerant stored in the gas-liquid separator 5 increases, so the refrigerant flowing through the gas injection pipe 8 becomes a liquid-rich refrigerant. Conversely, if the valve opening degree of the second decompression device 6 is increased, the amount of refrigerant stored in the gas-liquid separator 5 decreases, so the refrigerant flowing through the gas injection pipe 8 becomes a gas-rich refrigerant.
[0017]
Next, the flow of the refrigerant during the heating operation will be described. At this time, the connection between the four-way valve 2 and the gas-liquid separator 5 is switched as indicated by a dotted line.
Therefore, the refrigerant discharged from the compressor 1 passes through the indoor heat exchanger 7, the second decompression device 6, the gas-liquid separator 5, the first decompression device 4, and the outdoor heat exchanger 3, so that the compressor 1 Returned to At this time, by opening the on-off valve 9, the gas refrigerant separated by the gas-liquid separator 5 is introduced into the compressor 1 through the gas injection pipe 8.
[0018]
Here, the case where it switches to the defrost operation from the state of the above heating operation is demonstrated. The connection between the four-way valve 2 and the gas-liquid separator 5 is switched to the state indicated by the solid line.
At this time, the on-off valve 9 is opened to perform gas injection. The valve opening degree of the first pressure reducing device 4 is fully opened. Thus, the compressor input at the time of a defrost operation can be increased by fully opening the valve opening degree of the 1st pressure reduction apparatus 4. FIG. Moreover, since the liquid-rich refrigerant can be injected as described above by narrowing the valve opening degree of the second decompression device 6, the compressor input can be further increased.
In this way, the defrosting operation time can be shortened. Note that the first pressure reducing device 4 does not necessarily need to be fully open, and a valve opening of 73% or more with respect to the fully open state is preferable from the flow rate characteristics of FIG. Further, it is preferable that the second decompression device 6 has a throttling effect if it is narrowed to 73% or less.
[0019]
Although the defrosting operation is performed in the above state, the on-off valve 9 is closed and the injection is turned off before the defrosting operation is finished. The predetermined time from this injection off to the end of the defrosting operation is about 15 to 30 seconds.
Thus, by not performing the injection for a predetermined time before the end of the defrosting operation, a significant temperature drop in the compressor at the end of the defrosting operation can be prevented. Accordingly, it is possible to improve the rising characteristics after resuming the heating operation. In addition, even if it does not perform injection before completion | finish of a defrost operation, it does not have big influence on a defrost operation time. That is, in the defrosting operation, in the state where frost remains in part, the growth of frost after the return to heating operation is fast and the interval between the defrosting operations is shortened. Continue until frost formation is completely removed. However, this partially remaining frost can be sufficiently removed by the conduction of heat already applied to the evaporator to the frosted part, but it is sufficient unless heat conduction to the frosted part is performed. Cannot be removed. Therefore, even if the compression function is increased, a predetermined time for heat conduction is always required, and even if the amount of high-temperature gas introduced is increased, the time for removing partially remaining frost cannot be greatly shortened. is there.
In the above case, the case where the injection is not performed for a predetermined time before the end of the defrosting operation has been described. However, the gas injection may be performed by restricting the valve opening of the first pressure reducing device to 73% or less. . Also in this case, since the injection amount is reduced, it is possible to prevent a significant temperature drop in the compressor at the end of the defrosting operation.
[0020]
Next, the operation state at the time of resuming the heating operation after the completion of the defrosting operation will be described.
First, the heating operation is performed by switching the four-way valve 2 as indicated by the dotted line as described above. At this time, the on-off valve 9 is closed and the injection is turned off. Then, after driving for a predetermined time with the injection turned off, the injection is turned on. The predetermined time at this time is about 5 minutes. The predetermined time may be a predetermined time, but when the discharge temperature of the compressor 1 is detected and it is detected that the discharge temperature has become a predetermined value or more, the injection is turned on. Also good. In this case, since it can control based on the exact state of the compressor 1, heating start-up performance can be improved more.
In addition to the case where the injection is completely turned off, the amount of refrigerant injected may be reduced by restricting the second pressure reducing device 6 to 73% or less.
[0021]
It is more effective to use R410A as a refrigerant in the above refrigeration cycle. R410A has a small pressure loss compared to, for example, the R22 refrigerant that is currently generally used. Therefore, the enthalpy of the evaporator can be increased by further restricting the first decompression device 4 during the cooling / defrosting operation and the second decompression device 6 during the heating operation.
[0022]
【The invention's effect】
As is clear from the above description, the present invention controls the valve opening degree of each decompression device arranged before and after the gas-liquid separator, so that the refrigerant state stored in the gas-liquid separator and the gas injection The amount of refrigerant flowing through the pipe can be controlled. Therefore, since the amount of refrigerant to be injected and the state of the refrigerant can be controlled according to the operation state, the defrosting operation time can be shortened or the start-up performance of the heating operation after the defrosting operation can be improved. .
[Brief description of the drawings]
FIG. 1 is a refrigeration cycle diagram according to an embodiment of the present invention. FIG. 2 is a flow characteristic diagram of a decompression device according to the embodiment.
DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Condenser 4 First decompression device 5 Gas-liquid separator 6 Second decompression device 7 Evaporator 8 Gas injection piping 9 On-off valve

Claims

A compressor, a four-way valve, an outdoor heat exchanger, a first pressure reducing device, a gas-liquid separator, a second pressure reducing device, and an indoor heat exchanger are connected in an annular manner in order by piping, and the gas-liquid separator and the compression In the refrigeration cycle apparatus connected to the machine with a pipe for gas injection, the first decompressor and the second decompressor are the decompressors with variable valve opening, and the first decompressor and the second decompressor The valve opening of the device is changed according to the operating state of the refrigeration cycle, and the refrigerant discharged from the compressor is changed to the outdoor heat exchanger, the first pressure reducing device, the gas-liquid by switching the four-way valve During the defrosting operation in which the separator, the second decompression device, and the indoor heat exchanger are sequentially flowed, the valve opening degree of the first decompression device is opened to 73% or more to perform gas injection. Injection function The control device of the refrigeration cycle with.

2. The control device for a refrigeration cycle having an injection function according to claim 1 , wherein during the defrosting operation, gas injection is performed by restricting a valve opening of the second decompression device to 73% or less.

A compressor, a four-way valve, an outdoor heat exchanger, a first pressure reducing device, a gas-liquid separator, a second pressure reducing device, and an indoor heat exchanger are connected in an annular manner in order by piping, and the gas-liquid separator and the compression In the refrigeration cycle apparatus connected to the machine with a pipe for gas injection, the first decompressor and the second decompressor are the decompressors with variable valve opening, and the first decompressor and the second decompressor The valve opening of the device is changed according to the operating state of the refrigeration cycle, and the refrigerant discharged from the compressor is changed to the outdoor heat exchanger, the first pressure reducing device, the gas-liquid by switching the four-way valve After completing the defrosting operation that sequentially flows to the separator, the second decompression device, and the indoor heat exchanger, the valve opening of the second decompression device is reduced to 73% or less for a predetermined time after the heating operation is resumed. Squeeze and perform gas injection, The second control unit of the refrigeration cycle with the features and to Louis Njekushon function to carry out gas injection open than the valve opening in the valve opening said predetermined time decompressor after.

2. The control apparatus for a refrigeration cycle having an injection function according to claim 1 , wherein gas injection is performed by restricting the valve opening of the first decompression device to 73% or less for a predetermined time before the end of the defrosting operation. .

A compressor, a four-way valve, an outdoor heat exchanger, a pressure reducing device, a gas-liquid separator, and an indoor heat exchanger are connected in a ring shape by piping, and the gas-liquid separator and the compressor are connected by gas injection piping. In the cycle apparatus, R410A is used as a refrigerant, and the refrigerant discharged from the compressor by switching the four-way valve is converted into the outdoor heat exchanger, the first pressure reducing device, the gas-liquid separator, the second Refrigeration having an injection function characterized by performing gas injection when the discharge temperature of the compressor becomes a predetermined value or more during heating operation after completion of the defrosting operation that sequentially flows through the decompression device and the indoor heat exchanger, respectively. Cycle control device.

A compressor, a four-way valve, an outdoor heat exchanger, a pressure reducing device, a gas-liquid separator, and an indoor heat exchanger are connected in a ring shape by piping, and the gas-liquid separator and the compressor are connected by gas injection piping. In the cycle apparatus, R410A is used as a refrigerant, and the refrigerant discharged from the compressor by switching the four-way valve is converted into the outdoor heat exchanger, the first pressure reducing device, the gas-liquid separator, the second A controller for a refrigeration cycle having an injection function, wherein gas injection is performed after elapse of a predetermined time from the resumption of heating operation during heating operation after completion of the defrosting operation that sequentially flows through the decompression device and the indoor heat exchanger, respectively .

A compressor, a four-way valve, an outdoor heat exchanger, a pressure reducing device, a gas-liquid separator, and an indoor heat exchanger are connected in a ring shape by piping, and the gas-liquid separator and the compressor are connected by gas injection piping. In the cycle apparatus, R410A is used as a refrigerant, and the refrigerant discharged from the compressor by switching the four-way valve is converted into the outdoor heat exchanger, the first pressure reducing device, the gas-liquid separator, the second A control apparatus for a refrigeration cycle having an injection function, characterized in that gas injection is not performed for a predetermined time before the defrosting operation is sequentially performed through the decompression device and the indoor heat exchanger .

5. The control apparatus for a refrigeration cycle having an injection function according to claim 1, wherein R410A is used as a refrigerant.