JP3680143B2

JP3680143B2 - Refrigeration equipment

Info

Publication number: JP3680143B2
Application number: JP15722394A
Authority: JP
Inventors: 慎之介山本
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 1994-07-08
Filing date: 1994-07-08
Publication date: 2005-08-10
Anticipated expiration: 2020-08-10
Also published as: JPH0828995A

Description

【０００１】
【産業上の利用分野】
本発明は、例えばビルの地下室等に設置する第一ユニットと、ビルの屋上等に設置する第二ユニットとを備え、各ユニット間を長尺な冷媒通路で連結した冷凍装置に関する。
【０００２】
【従来の技術】
近年、この種の冷凍装置は、ビル空調システムを中心として盛んに用いられてきている。
【０００３】
又、冷凍装置の停止時の制御について、実公平２−３６０５９号公報に開示されたものが知られている。このものは、図３に示すように、圧縮機Ｐ、四路切換弁Ｂ、暖房時に凝縮器となり、冷房時に蒸発器となる利用側熱交換器Ｃ、冷房用膨張機構Ｖ、受液器Ｒ、暖房用膨張機構Ｗ、暖房時に蒸発器となり、冷房時に凝縮器となる熱源側熱交換器Ｅ、サクションアキュムレータＳを順次冷媒配管Ａを介して接続しており、冷媒通路における高圧域と低圧域との間に均圧通路Ｘ，Ｙを設けて、運転停止時、その通路中の開閉弁Ｊ，Ｋを開くことにより、高圧と低圧とを均圧し、再起動の容易化等が図れるようにしている。
【０００４】
【発明が解決しようとする課題】
しかし、図３に示す回路を、ビル空調システム等のユニット間を上下に長い冷媒通路で連結する冷凍装置には採用し難い問題がある。即ち、熱源側熱交換器Ｅの設置位置が高く、該熱源側熱交換器Ｅと膨張機構Ｗの出口部とのヘッド差が大きいため、停止時、均圧により、暖房運転時は低圧域となる膨張機構Ｗの下流に位置する熱源側熱交換器Ｅ側も、高圧域となる膨張機構Ｗの上流に位置する受液器Ｒ側も、同じ圧力となり、熱源側熱交換器Ｅ側の冷媒はその落差によって低位の受液器Ｒ等に回収され、再起動時に、受液器Ｒ等に溜っている液冷媒が設置位置の高い熱源側熱交換器Ｅに持ち上がり難くなり、熱源側熱交換器Ｅに冷媒が流れずに、低圧が下がり過ぎると共に能力が出ない問題が起こる。特に、ビルの高層化に伴い、この問題が顕著となる。
【０００５】
本発明の主目的は、ビル空調システム等の冷媒通路が上下に長いヘッド差のあるシステムにおいて、暖房運転の起動時、高位置にある熱源側熱交換器側に円滑に冷媒を持ち上げることができ、暖房運転の立上がりを良好且つ早期になし得る冷凍装置を提供する点にある。
【０００６】
【課題を解決するための手段】
そこで、上記主目的を達成するため、請求項１記載の発明は、圧縮機（１）、利用側熱交換器（２）及び膨張機構（３）をもつ第一ユニット（１０）と、該第一ユニット（１０）に対し高位に設置する熱源側熱交換器（４）をもつ第二ユニット（２０）とを備え、これらユニット間を長尺な冷媒通路（５６，５７）を介して接続し、利用側熱交換器（２）を凝縮器に、熱源側熱交換器（４）を蒸発器とする暖房運転を可能にすると共に、停止時、冷媒通路における高圧域と低圧域とを均圧する均圧通路（６）を設けた冷凍装置において、暖房運転時の高圧液路（５５）を開閉する第一開閉手段（７１）と、暖房運転時の低圧ガス路（５７）を開閉する第二開閉手段（７２）とを設けると共に、暖房運転の停止時、第一及び第二開閉手段（７１，７２）を閉鎖した後に均圧通路（６）を開く停止時制御手段（８）と、暖房運転の起動時、第一開閉手段（７１）を開いた後に、第二開閉手段（７２）を遅延させて開く起動時制御手段（９）とを設け、
起動時制御手段（９）が、高低差圧が所定値以下のとき、第一開閉手段（７１）を全閉から全開に制御し、高低差圧が所定値を越えるとき、第一開閉手段（７１）を全閉から徐々にその開度を大きくしていく第一開閉手段制御部（９１）を備えることを特徴とする冷凍装置である。
【０００７】
請求項２記載の発明は、圧縮機（１）、利用側熱交換器（２）及び膨張機構（３）をもつ第一ユニット（１０）と、該第一ユニット（１０）に対し高位に設置する熱源側熱交換器（４）をもつ第二ユニット（２０）とを備え、これらユニット間を長尺な冷媒通路（５６，５７）を介して接続し、利用側熱交換器（２）を凝縮器に、熱源側熱交換器（４）を蒸発器とする暖房運転を可能にすると共に、停止時、冷媒通路における高圧域と低圧域とを均圧する均圧通路（６）を設けた冷凍装置において、暖房運転時の高圧液路（５５）を開閉する第一開閉手段（７１）と、暖房運転時の低圧ガス路（５７）を開閉する第二開閉手段（７２）とを設けると共に、暖房運転の停止時、第一及び第二開閉手段（７１，７２）を閉鎖した後に均圧通路（６）を開く停止時制御手段（８）と、暖房運転の起動時、第一開閉手段（７１）を開いた後に、第二開閉手段（７２）を遅延させて開く起動時制御手段（９）とを設け、
起動時制御手段（９）が、圧縮機（１）に吸い込ませる吸入ガスの湿り状態が過度にならないように第二開閉手段（７２）を全閉から徐々にその開度を大きくしていく第二開閉手段制御部（９２）を備えることを特徴とする冷凍装置である。
【０００８】
請求項３記載の発明は、起動時制御手段（９）が、暖房運転の起動時、圧縮機（１）の運転の前に、第一開閉手段（７１）を開け、圧縮機（１）の運転の後に、第二開閉手段（７２）を開けるものであることを特徴とする。
【０００９】
請求項４記載の発明は、第一開閉手段（７１）と膨張機構（３）とを兼用させていることを特徴とする。
【００１１】
【作用】
請求項１記載の発明では、暖房運転の停止時、停止時制御手段８により、第一及び第二開閉手段７１，７２が閉鎖された後に、均圧通路６が開かれる。このため、各開閉手段７１，７２で塞き止める第一ユニット１０側の圧力を、運転時の高圧圧力よりも低いが、低圧の第二ユニット２０側よりも高圧の所定の圧力域に均圧することができる。この均圧により、圧縮機１の吸入側と吐出側とが同圧となり、再起動時の負荷を軽減できるなどの均圧の利点が得られる。そして、暖房運転の起動時、起動時制御手段９により、先ず第一開閉手段７１が開けられるため、第一ユニット１０側に滞留する冷媒は、第一ユニット１０側と第二ユニット２０側との間の高低差圧により、長い冷媒通路５６を下から上に向けて流れて、低圧の熱源側熱交換器４側に持ち上げられる。続いて第二開閉手段７２が遅延して開き、冷凍サイクルが形成されて冷媒が循環することになるのであり、このとき、予め、熱源側熱交換器４あるいはその近くに冷媒が持ち上げられているため、定常運転に移行するまでの時間は早く、暖房運転の立ち上がりをスムーズにすることができる。
また、停止時に第一及び第二開閉手段７１，７２により塞き止めた第一ユニット１０側の均圧域と、第二ユニット２０側の低圧域との間の高低差圧が比較的小さく、その高低差圧が所定値以下のときには、第一開閉手段制御部９１により、第一開閉手段７１は全閉から全開に制御される。このため、熱源側熱交換器４側に向けて第一ユニット１０側からできるだけ多くの冷媒が移送され、熱源側熱交換器４側の冷媒切れの問題を低減することができる。一方、第一ユニット１０側の均圧域と第二ユニット２０側の低圧域との間の高低差圧が比較的大きく、その高低差圧が所定値を越えるとき、第一開閉手段７１は全閉から徐々にその開度が大きくされる。このため、熱源側熱交換器４に一気に過大な量の液が持ち上げられてしまうのを防止でき、起動当初、圧縮機１の液の吸込みを低減することができる。このように、高低差圧に応じて、熱源側熱交換器４側に持ち上げる冷媒量を適正に制御するから、更に良好な運転の立上げを行うことができる。
【００１２】
請求項２記載の発明では、暖房運転の停止時、停止時制御手段８により、第一及び第二開閉手段７１，７２が閉鎖された後に、均圧通路６が開かれる。このため、各開閉手段７１，７２で塞き止める第一ユニット１０側の圧力を、運転時の高圧圧力よりも低いが、低圧の第二ユニット２０側よりも高圧の所定の圧力域に均圧することができる。この均圧により、圧縮機１の吸入側と吐出側とが同圧となり、再起動時の負荷を軽減できるなどの均圧の利点が得られる。そして、暖房運転の起動時、起動時制御手段９により、先ず第一開閉手段７１が開けられるため、第一ユニット１０側に滞留する冷媒は、第一ユニット１０側と第二ユニット２０側との間の高低差圧により、長い冷媒通路５６を下から上に向けて流れて、低圧の熱源側熱交換器４側に持ち上げられる。続いて第二開閉手段７２が遅延して開き、冷凍サイクルが形成されて冷媒が循環することになるのであり、このとき、予め、熱源側熱交換器４あるいはその近くに冷媒が持ち上げられているため、定常運転に移行するまでの時間は早く、暖房運転の立ち上がりをスムーズにすることができる。
また、暖房運転の起動時で、第二開閉手段７２が開かれる際、第二開閉手段制御部９２により、圧縮機１に吸い込ませる吸入ガスの湿り状態が過度にならないように、その開度が全閉から徐々に大きくされる。このため、起動当初、圧縮機１の液の吸込みをより確実に防止でき、より一層良好な運転の立上げを行うことができる。
請求項３記載の発明では、暖房運転の起動時、先ず第一開閉手段７１が開き、次に圧縮機１が運転されて、その後に第二開閉手段７２が開かれる。こうして、圧縮機１の運転を開始する際には、未だ第二開閉手段７２は閉鎖された状態である。このため、圧縮機１の運転に先立つ第一開閉手段７１の開動作によって熱源側熱交換器４に過剰に液が持ち上げられた場合や、停止時に第二開閉手段７２の上流側に液冷媒が滞留している場合等にあっても、圧縮機１は液を吸込むことはなく、該圧縮機１を保護できながら、その起動トルクを低減することができる。こうして、一層良好な運転の立上げを行うことができる。
【００１５】
請求項４記載の発明では、第一開閉手段７１は膨張機構３と兼用化でき、これら第一開閉手段７１と膨張機構３とを兼用することにより、少ない部品で簡易に所期の目的を達成することができる。
【００１６】
【実施例】
図１は、冷暖可能としたビル用ヒートポンプ式冷凍装置である。ビルの地下室に、圧縮機１、利用側熱交換器２等をもつ第一ユニット１０を、ビルの屋上に、熱源側熱交換器４をもつ第二ユニット２０をそれぞれ設置するものである。圧縮機１の吐出口１１から、吐出管５１、四路切換弁６０の第一固定ポート６１、同四路切換弁６０の第一切換ポート６３、ガス管５２、暖房時は凝縮器となり冷房時は蒸発器となる利用側熱交換器２、液管５３、電動弁から成る冷房用膨張機構３０、高圧液管５４、受液器８１、高圧液管５５、電動弁から成る暖房用膨張機構３、長尺な液管５６、暖房時は蒸発器となり冷房時は凝縮器となる熱源側熱交換器４、長尺なガス管５７、四路切換弁６０の第二切換ポート６４、同四路切換弁６０の第二固定ポート６２、サクションアキュムレータ８２、吸入管５８、圧縮機１の吸入口１２へと至る配管構成をもつものである。尚、３１は、暖房時に冷房用膨張機構３０を側路するバイパス用逆止弁、３２は、冷房時に暖房用膨張機構３を側路するバイパス用逆止弁である。
【００１７】
こうして、暖房運転時、冷媒は、符号で追うと１、１１、５１、６１、６０、６３、５２、２、５３、３１、５４、８１、５５、３、５６、４、５７、６４、６０、６２、８２、５８、１２、１という経路で循環し、凝縮器となる利用側熱交換器２で暖房用の温水を生成するようにしている。
【００１８】
一方、冷房運転時、冷媒は、同じく符号で追うと１、１１、５１、６１、６０、６４、５７、４、５６、３２、５５、８１、５４、３０、５３、２、５２、６３、６０、６２、８２、５８、１２、１という経路で循環し、蒸発器となる利用側熱交換器２で冷房用の冷水を生成するようにしている。
【００１９】
又、高圧域である受液器８１と低圧域であるサクションアキュムレータ８２との間には、配管から成る均圧通路６を接続しており、該通路６に介装する電磁弁から成る開閉手段６００を運転時は閉じるが、停止時には開くことにより、停止時に冷媒通路における高圧域と低圧域とを均圧するようにしている。
【００２０】
以上の構成で、暖房運転時に高圧液路となる液管５５に、該液管５５を開閉する第一開閉手段７１を設けると共に、暖房運転時に低圧ガス路となるガス管５７に、該ガス管５７を開閉する第二開閉手段７２を設ける。第一開閉手段７１は、電動弁から成る暖房用膨張機構３と兼用するものであり、全閉状態と全開状態の他、全閉から全開にわたる範囲内で、その開度を所定の開度に制御できるものである。又、第二開閉手段７２は、同様に電動弁から成るものであり、同じく、全閉状態と全開状態の他、全閉から全開にわたる範囲内で、その開度を所定の開度に制御できるものである。尚、第一開閉手段７１は、暖房用膨張機構３と兼用させる他、該膨張機構３とは別に液管５５に設けてもよい。又、第二開閉手段７２は、長尺なガス管５７の途中に介装することになるが、このガス管５７における第一ユニット１０側近くでも、第二ユニット２０側近くでも何れの位置に介装してもよい。
【００２１】
そして、暖房運転の停止時、第一及び第二開閉手段７１，７２を閉鎖した後に均圧通路６を開く停止時制御手段８と、暖房運転の起動時、第一開閉手段７１を開いた後に第二開閉手段７２を遅延させて開く起動時制御手段９とを設ける。
【００２２】
起動時制御手段９は、暖房運転の起動時、各開閉手段７１，７２を開くタイミングを、圧縮機１の運転前後を考慮して決めており、暖房運転の起動時、圧縮機１の運転の前に、第一開閉手段７１を開け、圧縮機１の運転の後に、第二開閉手段７２を開けるものである。又、この起動時制御手段９は、停止時の第一及び第二開閉手段７１，７２の閉動作により塞き止めた第一ユニット１０側の均圧域と、第二ユニット２０側の低圧域との間の高低差圧が所定値以下のとき、第一開閉手段７１を全閉から全開に制御し、その高低差圧が所定値を越えるとき、第一開閉手段７１を全閉から徐々にその開度を大きくしていく第一開閉手段制御部９１を備えるものである。更に、この起動時制御手段９は、第二開閉手段７２を開く際、圧縮機１に吸い込ませる吸入ガスの湿り状態が過度にならないように、該第二開閉手段７２を全閉から徐々にその開度を大きくしていく第二開閉手段制御部９２を備えるものである。
【００２３】
停止時制御手段８及び起動時制御手段９は、マイクロコンピュータを具備する制御器１００を用いて構築するものであり、該制御器１００の入力側には、運転の起動指令及び停止指令を発するサーモスイッチ等から成る起動及び停止指令手段９００と、吐出管５１に設ける第一圧力検出器ＰＨと、熱源側熱交換器４と第二開閉手段７２との間のガス管５７に設ける第二圧力検出器ＰＬと、同じくガス管５７に設ける温度検出器Ｔと、吸入管５８に設ける第三圧力検出器ＬＰとを入力させている。出力側には、制御対象となる第一及び第二開閉手段７１，７２、均圧通路６を開閉する開閉手段６００、及び圧縮機１を接続している。
【００２４】
こうして、図２に示すように、運転中に（ステップａ）、起動及び停止指令手段９００から停止指令が入ると（ステップｂ）、第一開閉手段７１及び第二開閉手段７２が全閉に向けて制御され（ステップｃ）、第三圧力検出器で検出する低圧圧力ＬＰが設定値以下に低下した後（ステップｄ）、圧縮機１を停止させて冷凍機の運転を停止させる（ステップｅ）。そして、この後に、均圧通路６の開閉手段６００を開にして第一ユニット１０側における高圧域と低圧域とを均圧させる（ステップｆ）。
【００２５】
次に、運転停止状態から、起動及び停止指令手段９００から起動指令が入ると（ステップｇ）、第一圧力検出器ＰＨで検出する第一ユニット１０側の高圧圧力ＰＨ（均圧圧力）と、第二圧力検出器ＰＬで検出する第二ユニット２０側の低圧圧力ＰＬとの間の高低差圧ＰＨ−ＰＬが、所定値ＨＰを越えるか否かを判定する（ステップｈ）。所定値ＨＰは、第一ユニット１０と第二ユニット２０とのヘッド差（ｋｇ／ｃｍ² ）、すなわち第一ユニット１０と第二ユニット２０との間の高低落差（ｃｍ）に液比重（ｋｇ／ｃｍ³ ）を乗じた値に設定している。尚、所定値は、ヘッド差に一致させる他、このヘッド差に近い値に設定してもよい。
【００２６】
そして、ステップｈの判定で、高低差圧ＰＨ−ＰＬが、所定値ＨＰを越えることが無く、該所定値ＨＰ以下のときには、第一開閉手段７１を全閉から全開に制御し（ステップｉ）、この第一開閉手段７１が全開となった後に、圧縮機１の運転を開始させ、冷凍機を起動する（ステップｊ）。
【００２７】
一方、高低差圧ＰＨ−ＰＬが所定値ＨＰを越えるとき、起動直前、つまり圧縮機１の運転を開始する直前に、第一開閉手段７１を全閉状態から開き始め、徐々にその開度を大きくしていくのであり（ステップｋ）、この第一開閉手段７１の開き始めから一定時間経過して該第一開閉手段７１の開度が少し開いた時点で、圧縮機１の運転を開始させ、冷凍機を起動する（ステップｎ）。
【００２８】
続いて、圧縮機１の運転を開始させた後に、第二圧力検出器ＰＬで検出する吸入ガス圧力と、温度検出器Ｔで検出する吸入ガス温度とに基づいて、圧縮機１に吸い込ませる吸入ガスの湿り状態が過度にならないように、例えば、その過熱度が５ｄｅｇ以上に保たれるように、第二開閉手段７２を全閉から徐々にその開度を大きくしていき（ステップｑ）、通常運転に移行させる（ステップｒ）。
【００２９】
こうして、以上の構成により、暖房運転の停止時、各開閉手段７１，７２を閉鎖した後に均圧通路６を開くため、各開閉手段７１，７２で塞き止める第一ユニット１０側の圧力を、低圧の第二ユニット２０側よりも高圧の所定の圧力域に均圧することができ、この均圧により圧縮機１の吸入側と吐出側とを同圧にでき、再起動時の負荷を軽減できるなどの均圧の利点が得られる。そして、暖房運転の起動時、第一ユニット１０側と第二ユニット２０側との間の高低差圧ＰＨ−ＰＬに基づいて、その高低差圧が所定値ＨＰ以下の比較的小さい場合は、第一開閉手段７１の全開制御により、一度にできるだけ多くの冷媒を熱源側熱交換器４側に向けて移送でき、その高低差圧が所定値ＨＰを越える比較的大きい場合は、第一開閉手段７１の緩やかな開度の拡大により、少しずつ冷媒を熱源側熱交換器４側に移送でき、適正量の冷媒を熱源側熱交換器４側に持ち上げることができるのであり、その後の圧縮機１の運転及び湿り制御を伴う第二開閉手段７２の開制御により、圧縮機１に液を吸い込ませることなく、迅速且つ良好に定常運転に移行させることができるのである。
【００３０】
以上の実施例では、冷房と暖房とを切換える所謂ヒートポンプ式のものを示したが、暖房専用機にも同様に適用することができる。又、圧縮機１は、スクロール式のものでも、ロータリー式のものでも、ターボ式のものでも何れでもよく、圧縮機の型式は特に限定されるものではない。
【００３１】
【発明の効果】
請求項１記載の発明によれば、ビル空調システム等の冷媒通路が上下に長いヘッド差のあるシステムにおいて、暖房運転の停止時、停止時制御手段８により、第一及び第二開閉手段７１，７２を閉鎖した後に均圧通路６を開くため、各開閉手段７１，７２で塞き止める第一ユニット１０側の圧力を、低圧の第二ユニット２０側よりも高圧の圧力域に均圧することができ、再起動時の負荷軽減など均圧の利点が得られるし、暖房運転の起動時は、起動時制御手段９により、第二開閉手段７２に先立つ第一開閉手段７１の開放によって、予め、熱源側熱交換器４あるいはその近くに冷媒を持ち上げることができるため、暖房運転の立上がりを良好且つ早期に行うことができる。
また、第一開閉手段制御部９１により、暖房運転の起動時、高低差圧が所定値以下の低差圧時は、第一開閉手段７１は全閉から全開に制御され、できるだけ多くの冷媒を熱源側熱交換器４側に移送でき、高低差圧が所定値を越える高差圧時は、第一開閉手段７１は全閉から徐々にその開度が大きくされ、熱源側熱交換器４に一気に過大な量の液が持ち上げられるのを防止できるため、熱源側熱交換器４での冷媒切れ及び圧縮機１の液吸込みを低減でき、更に良好な運転の立上げを行うことができる。
【００３２】
請求項２記載の発明によれば、ビル空調システム等の冷媒通路が上下に長いヘッド差のあるシステムにおいて、暖房運転の停止時、停止時制御手段８により、第一及び第二開閉手段７１，７２を閉鎖した後に均圧通路６を開くため、各開閉手段７１，７２で塞き止める第一ユニット１０側の圧力を、低圧の第二ユニット２０側よりも高圧の圧力域に均圧することができ、再起動時の負荷軽減など均圧の利点が得られるし、暖房運転の起動時は、起動時制御手段９により、第二開閉手段７２に先立つ第一開閉手段７１の開放によって、予め、熱源側熱交換器４あるいはその近くに冷媒を持ち上げることができるため、暖房運転の立上がりを良好且つ早期に行うことができる。
また、第二開閉手段制御部９２により、暖房運転の起動時、第二開閉手段７２は、圧縮機１に吸い込ませる吸入ガスの湿り状態が過度にならないように、その開度が全閉から徐々に大きくされるため、起動当初、圧縮機１の液の吸込みをより確実に防止でき、より一層良好な運転の立上げを行うことができる。
請求項３記載の発明によれば、暖房運転の起動時、圧縮機１の運転を開始する際に第二開閉手段７２を閉鎖しているため、圧縮機１は液を吸込むことなく、該圧縮機１を保護できながら、その起動トルクを低減でき、一層良好な運転の立上げを行うことができる。
【００３５】
請求項４記載の発明によれば、第一開閉手段７１と膨張機構３との兼用により少ない部品で簡易に所期の目的を達成することができる。
【図面の簡単な説明】
【図１】本発明に係る冷凍装置の一実施例を示す配管図。
【図２】同冷凍装置の制御手順を示すフローチャート。
【図３】従来の冷凍装置を示す配管図。
【符号の説明】
１；圧縮機、２；利用側熱交換器、３；膨張機構（暖房用膨張機構）、４；熱源側熱交換器、６；均圧通路、１０；第一ユニット、２０；第二ユニット、５６，５７；長尺な冷媒通路、５５；高圧液路、５７；低圧ガス路、７１；第一開閉手段、７２；第二開閉手段、８；停止時制御手段、９；起動時制御手段、９１；第一開閉手段制御部、９２；第二開閉手段制御部[0001]
[Industrial application fields]
The present invention relates to a refrigeration apparatus including a first unit installed in, for example, a basement of a building, and a second unit installed on the roof of a building, and the units connected by a long refrigerant passage.
[0002]
[Prior art]
In recent years, this type of refrigeration apparatus has been actively used mainly in building air conditioning systems.
[0003]
Moreover, what was disclosed in Japanese Utility Model Publication No. 2-336059 is known for control when the refrigeration apparatus is stopped. As shown in FIG. 3, the compressor P, the four-way switching valve B, a condenser at the time of heating and a use side heat exchanger C to be an evaporator at the time of cooling, an expansion mechanism V for cooling, and a receiver R An expansion mechanism W for heating, an evaporator during heating, and a heat source side heat exchanger E, which becomes a condenser during cooling, and a suction accumulator S are sequentially connected via a refrigerant pipe A, and a high pressure region and a low pressure region in the refrigerant passage The pressure equalizing passages X and Y are provided between them, and when the operation is stopped, the on-off valves J and K in the passages are opened to equalize the high and low pressures, thereby facilitating the restart. ing.
[0004]
[Problems to be solved by the invention]
However, there is a problem that the circuit shown in FIG. 3 is difficult to employ in a refrigeration apparatus that connects units such as a building air conditioning system with a vertically long refrigerant passage. That is, the installation position of the heat source side heat exchanger E is high, and the head difference between the heat source side heat exchanger E and the outlet of the expansion mechanism W is large. The heat source side heat exchanger E side located downstream of the expansion mechanism W and the liquid receiver R side located upstream of the expansion mechanism W in the high pressure region are at the same pressure, and the refrigerant on the heat source side heat exchanger E side Is collected in the lower receiver R or the like due to the drop, and at the time of restart, the liquid refrigerant accumulated in the receiver R or the like is not easily lifted to the heat source side heat exchanger E having a high installation position, and heat source side heat exchange is performed. The refrigerant does not flow into the vessel E, causing a problem that the low pressure is excessively lowered and the capacity is not obtained. In particular, this problem becomes conspicuous as the number of buildings rises.
[0005]
The main object of the present invention is to smoothly lift the refrigerant to the heat source side heat exchanger at a high position when the heating operation is started in a system having a long head difference in the refrigerant passage such as a building air conditioning system. Another object of the present invention is to provide a refrigeration apparatus that can achieve a good and early rise in heating operation.
[0006]
[Means for Solving the Problems]
Therefore, in order to achieve the main object, the invention described in claim 1 includes a first unit (10) having a compressor (1), a use side heat exchanger (2), and an expansion mechanism (3), and the first unit (10). And a second unit (20) having a heat source side heat exchanger (4) installed at a high level with respect to one unit (10), and these units are connected via a long refrigerant passage (56, 57). The heating side operation using the use side heat exchanger (2) as a condenser and the heat source side heat exchanger (4) as an evaporator is enabled, and at the time of stop, the high pressure region and the low pressure region are equalized. In the refrigeration apparatus provided with the pressure equalizing passage (6), the first opening / closing means (71) for opening and closing the high pressure liquid passage (55) during the heating operation and the second opening and closing for the low pressure gas passage (57) during the heating operation. And opening / closing means (72), and at the time of stopping the heating operation, the first and second opening / closing means (71) 72) The control means (8) at the time of stopping to open the pressure equalizing passage (6) after closing, and the second opening / closing means (72) is delayed after opening the first opening / closing means (71) at the start of heating operation. And a start-up control means (9) to be opened,
When the start-up control means (9) controls the first opening / closing means (71) from fully closed to fully open when the height differential pressure is below a predetermined value, and when the height differential pressure exceeds a predetermined value, the first opening / closing means ( 71) is a refrigeration apparatus comprising a first opening / closing means control section (91) that gradually increases the opening degree from fully closed.
[0007]
The invention according to claim 2 is a first unit (10) having a compressor (1), a use-side heat exchanger (2) and an expansion mechanism (3), and is installed at a higher level than the first unit (10). And a second unit (20) having a heat source side heat exchanger (4) that connects the units via long refrigerant passages (56, 57), and connects the use side heat exchanger (2). Refrigeration provided with a pressure equalizing passage (6) for equalizing the high pressure region and the low pressure region in the refrigerant passage at the time of stoppage while enabling heating operation using the heat source side heat exchanger (4) as an evaporator in the condenser. In the apparatus, a first opening / closing means (71) for opening and closing the high pressure liquid path (55) during heating operation and a second opening / closing means (72) for opening and closing the low pressure gas path (57) during heating operation are provided, When the heating operation is stopped, the first and second opening / closing means (71, 72) are closed and then the pressure equalizing passage (6 A control means (8) at the time of stopping, and a control means (9) at the time of startup that opens the first opening / closing means (71) with a delay after opening the first opening / closing means (71) at the start of the heating operation. Provided,
The start-up control means (9) gradually increases the opening degree of the second opening / closing means (72) from fully closed so that the wet state of the suction gas sucked into the compressor (1) does not become excessive. A refrigerating apparatus comprising a second opening / closing means control section (92).
[0008]
According to a third aspect of the present invention, the startup control means (9) opens the first opening / closing means (71) before starting the compressor (1) when the heating operation is started, and the compressor (1) The second opening / closing means (72) is opened after the operation.
[0009]
According to a fourth aspect of the present invention, the first opening / closing means (71) and the expansion mechanism (3) are used in combination.
[0011]
[Action]
According to the first aspect of the present invention, when the heating operation is stopped, the pressure equalizing passage 6 is opened after the first and second opening / closing means 71 and 72 are closed by the stop time control means 8. For this reason, the pressure on the first unit 10 side blocked by the opening / closing means 71 and 72 is equalized to a predetermined pressure region that is lower than the high pressure during operation but higher than the low pressure second unit 20 side. be able to. By this pressure equalization, the suction side and the discharge side of the compressor 1 become the same pressure, and the advantage of pressure equalization, such as reducing the load at the time of restart, is obtained. When the heating operation is started, the first opening / closing means 71 is first opened by the start time control means 9, so that the refrigerant staying on the first unit 10 side is between the first unit 10 side and the second unit 20 side. Due to the high and low pressure difference between them, the long refrigerant passage 56 flows from the bottom to the top and is lifted to the low-pressure heat source side heat exchanger 4 side. Subsequently, the second opening / closing means 72 opens with a delay, a refrigeration cycle is formed, and the refrigerant circulates. At this time, the refrigerant is lifted in advance to or near the heat source side heat exchanger 4. Therefore, the time until the transition to the steady operation is fast, and the start-up of the heating operation can be made smooth.
Further, the pressure difference between the pressure equalization area on the first unit 10 side blocked by the first and second opening / closing means 71 and 72 at the time of stop and the low pressure area on the second unit 20 side is relatively small, When the pressure difference is not more than a predetermined value, the first opening / closing means controller 91 controls the first opening / closing means 71 from fully closed to fully open. For this reason, as much refrigerant as possible is transferred from the first unit 10 side toward the heat source side heat exchanger 4 side, and the problem of running out of refrigerant on the heat source side heat exchanger 4 side can be reduced. On the other hand, when the pressure difference between the pressure equalization area on the first unit 10 side and the low pressure area on the second unit 20 side is relatively large and the pressure difference exceeds a predetermined value, the first opening / closing means 71 is The opening is gradually increased from closing. For this reason, it is possible to prevent an excessive amount of liquid from being lifted to the heat source side heat exchanger 4 at a stretch, and it is possible to reduce the suction of the liquid of the compressor 1 at the beginning of startup. As described above, since the amount of the refrigerant to be lifted to the heat source side heat exchanger 4 side is appropriately controlled according to the high and low differential pressures, it is possible to further start up the operation.
[0012]
In the second aspect of the invention, when the heating operation is stopped, the pressure equalizing passage 6 is opened after the first and second opening / closing means 71 and 72 are closed by the stop time control means 8. For this reason, the pressure on the first unit 10 side blocked by the opening / closing means 71 and 72 is equalized to a predetermined pressure region that is lower than the high pressure during operation but higher than the low pressure second unit 20 side. be able to. By this pressure equalization, the suction side and the discharge side of the compressor 1 become the same pressure, and the advantage of pressure equalization, such as reducing the load at the time of restart, is obtained. When the heating operation is started, the first opening / closing means 71 is first opened by the start time control means 9, so that the refrigerant staying on the first unit 10 side is between the first unit 10 side and the second unit 20 side. Due to the high and low pressure difference between them, the long refrigerant passage 56 flows from the bottom to the top and is lifted to the low-pressure heat source side heat exchanger 4 side. Subsequently, the second opening / closing means 72 opens with a delay, a refrigeration cycle is formed, and the refrigerant circulates. At this time, the refrigerant is lifted in advance to or near the heat source side heat exchanger 4. Therefore, the time until the transition to the steady operation is fast, and the start-up of the heating operation can be made smooth.
Further, when the second opening / closing means 72 is opened at the time of starting the heating operation, the opening degree of the intake gas to be sucked into the compressor 1 by the second opening / closing means control unit 92 is not excessive. Gradually increased from fully closed. For this reason, the suction of the liquid of the compressor 1 can be prevented more reliably at the beginning of the start-up, and the operation can be started even better.
According to the third aspect of the invention, when the heating operation is started, the first opening / closing means 71 is first opened, then the compressor 1 is operated, and then the second opening / closing means 72 is opened. Thus, when the operation of the compressor 1 is started, the second opening / closing means 72 is still closed. For this reason, when the liquid is excessively lifted to the heat source side heat exchanger 4 by the opening operation of the first opening / closing means 71 prior to the operation of the compressor 1, or when the liquid refrigerant is upstream of the second opening / closing means 72 when stopped. Even in the case of staying, the compressor 1 does not suck in the liquid, and the starting torque can be reduced while the compressor 1 can be protected. In this way, it is possible to further improve the operation.
[0015]
In the invention according to claim 4 , the first opening / closing means 71 can also be used as the expansion mechanism 3, and by using the first opening / closing means 71 and the expansion mechanism 3, the intended purpose can be achieved easily with a small number of parts. can do.
[0016]
【Example】
FIG. 1 shows a heat pump refrigeration system for buildings that can be cooled and heated. The first unit 10 having the compressor 1, the use side heat exchanger 2 and the like is installed in the basement of the building, and the second unit 20 having the heat source side heat exchanger 4 is installed on the roof of the building. From the discharge port 11 of the compressor 1, the discharge pipe 51, the first fixed port 61 of the four-way switching valve 60, the first switching port 63 of the four-way switching valve 60, the gas pipe 52, and a condenser during heating are used for cooling Is a use side heat exchanger 2 as an evaporator, a liquid pipe 53, a cooling expansion mechanism 30 comprising a motorized valve, a high pressure liquid pipe 54, a liquid receiver 81, a high pressure liquid pipe 55, and a heating expansion mechanism 3 comprising a motorized valve. A long liquid pipe 56, a heat source side heat exchanger 4 which becomes an evaporator during heating and a condenser during cooling, a long gas pipe 57, a second switching port 64 of the four-way switching valve 60, and the four-way The switching valve 60 has a piping configuration that extends to the second fixed port 62, the suction accumulator 82, the suction pipe 58, and the suction port 12 of the compressor 1. In addition, 31 is a bypass check valve that bypasses the cooling expansion mechanism 30 during heating, and 32 is a bypass check valve that bypasses the heating expansion mechanism 3 during cooling.
[0017]
Thus, during heating operation, the refrigerant follows the reference numerals 1, 11, 51, 61, 60, 63, 52, 2, 53, 31, 54, 81, 55, 3, 56, 4, 57, 64, 60. , 62, 82, 58, 12, and 1 are circulated, and hot water for heating is generated by the use-side heat exchanger 2 serving as a condenser.
[0018]
On the other hand, during the cooling operation, the refrigerant follows the same reference numerals 1, 11, 51, 61, 60, 64, 57, 4, 56, 32, 55, 81, 54, 30, 53, 2, 52, 63, It circulates through the path | routes 60, 62, 82, 58, 12, and 1 and it is made to produce | generate the cold water for cooling with the utilization side heat exchanger 2 used as an evaporator.
[0019]
A pressure equalizing passage 6 made of piping is connected between a liquid receiver 81 which is a high pressure region and a suction accumulator 82 which is a low pressure region, and an opening / closing means comprising an electromagnetic valve interposed in the passage 6. Although 600 is closed during operation, it is opened during stop so that the high pressure region and the low pressure region in the refrigerant passage are equalized during stop.
[0020]
With the above configuration, the first opening / closing means 71 that opens and closes the liquid pipe 55 is provided in the liquid pipe 55 that is a high-pressure liquid path during heating operation, and the gas pipe 57 is provided in the gas pipe 57 that is a low-pressure gas path during heating operation. Second opening / closing means 72 for opening / closing 57 is provided. The first opening / closing means 71 is also used as the heating expansion mechanism 3 composed of an electric valve, and in addition to the fully closed state and the fully opened state, the opening degree is set to a predetermined opening within a range from fully closed to fully opened. It can be controlled. Similarly, the second opening / closing means 72 is composed of a motor-operated valve. Similarly, in addition to the fully closed state and the fully opened state, the opening degree can be controlled to a predetermined opening within a range from fully closed to fully open. Is. The first opening / closing means 71 may be provided in the liquid pipe 55 separately from the expansion mechanism 3 in addition to being shared with the heating expansion mechanism 3. In addition, the second opening / closing means 72 is interposed in the middle of the long gas pipe 57, but at any position near the first unit 10 side or the second unit 20 side in the gas pipe 57. You may interpose.
[0021]
When the heating operation is stopped, the first and second opening / closing means 71 and 72 are closed and then the pressure equalizing passage 6 is opened. When the heating operation is started, the first opening / closing means 71 is opened. A startup control means 9 is provided that opens the second opening / closing means 72 with a delay.
[0022]
The start-up control means 9 determines the opening timing of the opening / closing means 71 and 72 in consideration of before and after the operation of the compressor 1 when the heating operation is started, and the operation of the compressor 1 is started when the heating operation is started. The first opening / closing means 71 is opened before, and the second opening / closing means 72 is opened after the operation of the compressor 1. The start-up control means 9 includes a pressure equalization area on the first unit 10 side closed by the closing operation of the first and second opening / closing means 71 and 72 at the time of stop, and a low pressure area on the second unit 20 side. The first opening / closing means 71 is controlled from fully closed to fully open when the height differential pressure between the first and the second differential pressure exceeds a predetermined value. A first opening / closing means control unit 91 for increasing the opening degree is provided. Further, when the second opening / closing means 72 is opened, the start-up control means 9 gradually opens the second opening / closing means 72 from fully closed so that the wet state of the suction gas sucked into the compressor 1 does not become excessive. A second opening / closing means control unit 92 for increasing the opening degree is provided.
[0023]
The control unit 8 at the time of stop and the control unit 9 at the time of start are constructed by using a controller 100 having a microcomputer. Start and stop command means 900 comprising a switch, the first pressure detector PH provided in the discharge pipe 51, and the second pressure detection provided in the gas pipe 57 between the heat source side heat exchanger 4 and the second opening / closing means 72. The temperature detector T provided in the gas pipe 57 and the third pressure detector LP provided in the suction pipe 58 are input. On the output side, the first and second opening / closing means 71 and 72 to be controlled, the opening / closing means 600 for opening and closing the pressure equalizing passage 6, and the compressor 1 are connected.
[0024]
In this way, as shown in FIG. 2, during operation (step a), when a stop command is input from the start and stop command means 900 (step b), the first opening / closing means 71 and the second opening / closing means 72 are fully closed. (Step c), and the low pressure LP detected by the third pressure detector drops below the set value (step d), then the compressor 1 is stopped and the operation of the refrigerator is stopped (step e). . Thereafter, the opening / closing means 600 of the pressure equalizing passage 6 is opened to equalize the high pressure region and the low pressure region on the first unit 10 side (step f).
[0025]
Next, when a start command is input from the start and stop command means 900 from the operation stop state (step g), a high pressure PH (equal pressure) on the first unit 10 side detected by the first pressure detector PH, It is determined whether or not the high / low differential pressure PH-PL between the low pressure PL on the second unit 20 side detected by the second pressure detector PL exceeds a predetermined value HP (step h). The predetermined value HP is a liquid specific gravity (kg / cm) between a head difference (kg / cm ² ) between the first unit 10 and the second unit 20, that is, a height drop (cm) between the first unit 10 and the second unit 20. cm ³ ). The predetermined value may be set to a value close to the head difference in addition to matching the head difference.
[0026]
When it is determined in step h that the high / low differential pressure PH-PL does not exceed the predetermined value HP and is equal to or lower than the predetermined value HP, the first opening / closing means 71 is controlled from fully closed to fully open (step i). After the first opening / closing means 71 is fully opened, the operation of the compressor 1 is started and the refrigerator is started (step j).
[0027]
On the other hand, when the high / low differential pressure PH-PL exceeds the predetermined value HP, the first opening / closing means 71 starts to open from the fully closed state immediately before starting, that is, immediately before starting the operation of the compressor 1, and the opening degree is gradually increased. When the opening degree of the first opening / closing means 71 is slightly opened after a lapse of a certain time from the start of opening of the first opening / closing means 71, the operation of the compressor 1 is started. Then, the refrigerator is started (step n).
[0028]
Subsequently, after starting the operation of the compressor 1, the suction to be sucked into the compressor 1 based on the suction gas pressure detected by the second pressure detector PL and the suction gas temperature detected by the temperature detector T. In order to prevent the gas from becoming excessively wet, for example, the opening degree of the second opening / closing means 72 is gradually increased from fully closed so that the degree of superheat is maintained at 5 deg or more (step q), Transition to normal operation (step r).
[0029]
Thus, with the above configuration, when the heating operation is stopped, in order to open the pressure equalizing passage 6 after closing each open / close means 71, 72, the pressure on the first unit 10 side blocked by each open / close means 71, 72 is The pressure can be equalized in a predetermined pressure range higher than the low pressure second unit 20 side, and the suction side and the discharge side of the compressor 1 can be made the same pressure by this pressure equalization, and the load at the time of restart can be reduced. The advantage of pressure equalization is obtained. And, when the heating operation is started, based on the height difference pressure PH-PL between the first unit 10 side and the second unit 20 side, when the height difference pressure is relatively small below a predetermined value HP, By controlling the full opening of the one opening / closing means 71, as much refrigerant as possible can be transferred toward the heat source side heat exchanger 4 side at a time, and when the high / low differential pressure exceeds a predetermined value HP, the first opening / closing means 71 Accordingly, the refrigerant can be gradually transferred to the heat source side heat exchanger 4 side, and an appropriate amount of refrigerant can be lifted to the heat source side heat exchanger 4 side. By the opening control of the second opening / closing means 72 accompanied with the operation and the wetness control, the compressor 1 can be quickly and satisfactorily shifted to the steady operation without sucking the liquid.
[0030]
In the above embodiment, a so-called heat pump type that switches between cooling and heating is shown, but the present invention can be similarly applied to a dedicated heater. The compressor 1 may be of a scroll type, a rotary type or a turbo type, and the type of the compressor is not particularly limited.
[0031]
【The invention's effect】
According to the first aspect of the present invention, in a system having a long head difference in the refrigerant passage such as a building air conditioning system, the first and second opening / closing means 71, In order to open the pressure equalizing passage 6 after closing 72, the pressure on the first unit 10 side blocked by the opening and closing means 71, 72 can be equalized to a pressure region higher than that on the low pressure second unit 20 side. It is possible to obtain an advantage of pressure equalization such as load reduction at the time of restart, and when starting the heating operation, by opening the first opening and closing means 71 prior to the second opening and closing means 72 by the starting time control means 9, Since the refrigerant can be lifted to or near the heat source side heat exchanger 4, the heating operation can be started well and quickly.
Further, the first opening / closing means control unit 91 controls the first opening / closing means 71 from fully closed to fully opened when starting the heating operation, and when the high / low differential pressure is a low differential pressure or less. When the high and low differential pressure exceeds the predetermined value and can be transferred to the heat source side heat exchanger 4 side, the opening degree of the first opening / closing means 71 is gradually increased from the fully closed state to the heat source side heat exchanger 4. Since it is possible to prevent an excessive amount of liquid from being lifted at a stretch, it is possible to reduce the exhaustion of the refrigerant in the heat source side heat exchanger 4 and the suction of the liquid in the compressor 1, and it is possible to start up a more favorable operation.
[0032]
According to the second aspect of the present invention, in the system having a long head difference in the refrigerant passage such as a building air conditioning system, the first and second opening / closing means 71, In order to open the pressure equalizing passage 6 after closing 72, the pressure on the first unit 10 side blocked by the opening and closing means 71, 72 can be equalized to a pressure region higher than that on the low pressure second unit 20 side. It is possible to obtain an advantage of pressure equalization such as load reduction at the time of restart, and when starting the heating operation, by opening the first opening and closing means 71 prior to the second opening and closing means 72 by the starting time control means 9, Since the refrigerant can be lifted to or near the heat source side heat exchanger 4, the heating operation can be started well and quickly.
Further, when the heating operation is started by the second opening / closing means control unit 92, the second opening / closing means 72 is gradually opened from fully closed so that the wet state of the suction gas sucked into the compressor 1 does not become excessive. Therefore, at the beginning of startup, the suction of the liquid of the compressor 1 can be prevented more reliably, and the operation can be started even better.
According to the third aspect of the present invention, since the second opening / closing means 72 is closed when the operation of the compressor 1 is started when the heating operation is started, the compressor 1 does not suck in the liquid and does not suck the liquid. While the machine 1 can be protected, its starting torque can be reduced, and the operation can be started even better.
[0035]
According to the fourth aspect of the invention, the intended purpose can be easily achieved with a small number of parts by using the first opening / closing means 71 and the expansion mechanism 3 together.
[Brief description of the drawings]
FIG. 1 is a piping diagram showing an embodiment of a refrigeration apparatus according to the present invention.
FIG. 2 is a flowchart showing a control procedure of the refrigeration apparatus.
FIG. 3 is a piping diagram showing a conventional refrigeration apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1; Compressor, 2; Use side heat exchanger, 3; Expansion mechanism (expansion mechanism for heating), 4; Heat source side heat exchanger, 6; Pressure equalizing passage, 10; First unit, 20; 56, 57; long refrigerant passage, 55; high-pressure liquid passage, 57; low-pressure gas passage, 71; first opening / closing means, 72; second opening / closing means, 8; stop-time control means, 9; 91; first opening / closing means control section; 92; second opening / closing means control section

Claims

A first unit (10) having a compressor (1), a use side heat exchanger (2) and an expansion mechanism (3), and a heat source side heat exchanger (4) installed at a higher position relative to the first unit (10) ) Having a second unit (20), and connecting these units via long refrigerant passages (56, 57), the use side heat exchanger (2) as a condenser, and the heat source side heat exchange. In the refrigeration system which enables the heating operation using the evaporator (4) as an evaporator and also has the pressure equalizing passage (6) for equalizing the high pressure region and the low pressure region in the refrigerant passage when stopped, the high pressure during the heating operation is provided. A first opening / closing means (71) for opening / closing the liquid passage (55) and a second opening / closing means (72) for opening / closing the low-pressure gas passage (57) during the heating operation are provided. And control means at the time of stop which opens the pressure equalizing passage (6) after closing the second opening / closing means (71, 72) 8), provided at the start of heating operation, after opening the first closing means (71), opening delays the second shut-off means (72) starting control means (9),
When the start-up control means (9) controls the first opening / closing means (71) from fully closed to fully open when the height differential pressure is below a predetermined value, and when the height differential pressure exceeds a predetermined value, the first opening / closing means ( 71) A refrigeration apparatus comprising a first opening / closing means control section (91) for gradually increasing the opening degree from fully closed.

A first unit (10) having a compressor (1), a use side heat exchanger (2) and an expansion mechanism (3), and a heat source side heat exchanger (4) installed at a higher position relative to the first unit (10) ) Having a second unit (20), and connecting these units through long refrigerant passages (56, 57), the use side heat exchanger (2) as a condenser, and the heat source side heat exchange. In the refrigeration apparatus provided with the pressure equalizing passage (6) for equalizing the high pressure region and the low pressure region in the refrigerant passage at the time of stopping, the heating operation using the evaporator (4) as an evaporator is possible. A first opening / closing means (71) for opening / closing the liquid passage (55) and a second opening / closing means (72) for opening / closing the low-pressure gas passage (57) during heating operation are provided. And control means at the time of stop which opens the pressure equalizing passage (6) after closing the second opening / closing means (71, 72) 8), provided at the start of heating operation, after opening the first closing means (71), opening delays the second shut-off means (72) starting control means (9),
The start-up control means (9) gradually increases the opening degree of the second opening / closing means (72) from fully closed so that the wet state of the suction gas sucked into the compressor (1) does not become excessive. A refrigeration apparatus comprising a two opening / closing means control section (92).

The start-up control means (9) opens the first opening / closing means (71) before the operation of the compressor (1) at the start of the heating operation, and after the operation of the compressor (1), the second opening / closing means. The refrigerating apparatus according to claim 1 or 2, wherein (72) is opened.

The refrigerating device according to any one of claims 1-3, characterized in that is combined with a first opening and closing means (71) and the expansion mechanism (3).