JP4265188B2

JP4265188B2 - Air conditioner

Info

Publication number: JP4265188B2
Application number: JP2002276719A
Authority: JP
Inventors: 直斎藤; 利彰吉川; 英知中川
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2002-09-24
Filing date: 2002-09-24
Publication date: 2009-05-20
Anticipated expiration: 2022-09-24
Also published as: JP2004116796A

Description

【０００１】
【発明の属する技術分野】
この発明は、暖房運転時に除霜運転を行う空気調和機に関するものである。
【０００２】
【従来の技術】
従来の空気調和機においては、圧縮機１、四方弁２、室外熱交換器３、膨張機構（電子制御式膨張弁）４、室内熱交換器５を順次配管で接続して冷凍サイクルを構成し、室内を暖める時、圧縮機１からの冷媒を四方弁２により室内熱交換器５から膨張機構４、及び室外熱交換器３に順次流し、室内を暖める暖房運転を行う。
【０００３】
しかし、この暖房運転を継続して、外気温が低くなると、蒸発器として機能する室外熱交換器に霜が付き、外気が熱交換器のフィンの間を流れなくなり、蒸発温度が低下し、暖房能力が低下するため、この霜を解かす運転、即ち、除霜運転を行うものの、この除霜運転を余り速く行ったり、或いは余り遅く行ったりすると、無駄なエネルギーを消費したり、或いは液バック現象を誘発して種々の問題を引き起こすこととなる。
【０００４】
なお、このことを考慮した代表的な従来の空気調和機としては、特開昭６１−１５３３３２号公報のようなものがある。
しかし、このものは室外熱交換器の蒸発器に付着した霜を解かす時、その解かすタイミングを、外気温度を検出する外気温度センサー８、及び蒸発温度を検出する蒸発温度センサー９の検出結果、並びに圧縮機の回転数に応じて行う、即ち、圧縮機の所定回転数における外気温度と蒸発温度との温度差が所定温度差以上になった時、除霜運転を行い、霜を解かす。
【０００５】
しかし、このように圧縮機の回転数毎の外気温度における蒸発温度のみに応じて除霜運転を行うと、蒸発温度は、そもそも圧縮機の回転数だけでなく、室外ファンや室内ファンの回転数によっても変化するため、精度の良い除霜運転を行うことができない。
即ち、例えば、室外ファンの回転数が上昇したり、或いは室内ファンの回転数が低下して、蒸発温度が低下し、外気温度と蒸発温度との温度差が所定温度差以上になった時、霜が余り付着していない状態でも、室外熱交換器に着霜したと判断して除霜運転を行うため、無駄なエネルギーを消費することになる。
【０００６】
また逆に、多くの霜が付着し、室外熱交換器が目詰まりを引き起しているにも関わらず、室外ファンの回転数上昇、或いは室内ファンの回転数低下により、蒸発温度が上昇して、外気温度と蒸発温度との温度差が小さくなり、所定温度差以下の時は、除霜運転をする必要がないと判断して、目詰まり状態で運転するため、暖房能力の低下や液バックによる圧縮機の損傷等を引き起したりする。
【０００７】
また、このような制御においては、除霜をしなくても良い蒸発温度（例えば、−１℃以上）の状態でも、室外熱交換器３の周囲外気の温度が外気の流れによってショートサイク等を起し、外気温度と蒸発温度との温度差が所定の温度差以上になると、除霜運転を行うため、無駄なエネルギーを消費したりする。
【０００８】
なお、その他の従来例としては、インバータ装置を有しない特開昭６０−２３３４３５号公報のようなものもある。
【０００９】
【発明が解決しようとする課題】
以上説明したように、従来技術の空気調和機では、無駄なエネルギーを消費したり、暖房能力の低下や液バックによるトラブルを引き起こすという問題点があった。
【００１０】
この発明は上記のような課題を解決するためになされたもので、暖房運転時の除霜運転を適正に行い、暖房性能が優れ、経済的で信頼性の高い空気調和機を得ることを目的とする。
【００１１】
【課題を解決するための手段】
この発明の空気調和機においては、回転数可変なインバータ圧縮機、四方弁、室内熱交換器、膨張機構、室外熱交換器が順次配管で接続されて構成され、室内を暖める当該空気調和機の暖房運転時にはインバータ圧縮機から吐出された暖かい冷媒が四方弁により室内熱交換器から膨張機構と室外熱交換器に順次流れる冷凍サイクルと、室内熱交換器の回転数可変な室内送風機と、室外熱交換器の回転数可変な室外送風機と、外気温度ｔａを検出する外気温度センサーと、暖房運転時には蒸発器として機能する室外熱交換器の温度ｔｅを検出する蒸発温度センサーと、外気温度センサーが検出した外気温度ｔａと蒸発温度センサーが検出した室外熱交換器の温度ｔｅを受信するとともに、インバータ圧縮機の回転数と室内送風機の回転数と室外送風機の回転数に対応した除霜開始温度差Δｔｄが予め設定された制御手段と、を備え、制御手段が、外気温度ｔａと室外熱交換器の温度ｔｅの差ｔａ−ｔｅである温度差Δｔを算出し、この算出した温度差Δｔと、その時のインバータ圧縮機の回転数と室内送風機の回転数と室外送風機の回転数に対応した除霜開始温度差Δｔｄと、を比較し、Δｔ＞Δｔｄなる状態が所定時間継続された場合に、四方弁を切換えて、インバータ圧縮機から吐出された暖かい冷媒を室内熱交換器に流す暖房運転から室外熱交換器に流す除湿運転に移行させるものである。
【００１２】
また、この発明の空気調和機においては、回転数可変なインバータ圧縮機、四方弁、室内熱交換器、膨張機構、室外熱交換器が順次配管で接続されて構成され、室内を暖める当該空気調和機の暖房運転時にはインバータ圧縮機から吐出された暖かい冷媒が四方弁により室内熱交換器から膨張機構と室外熱交換器に順次流れる冷凍サイクルと、室内熱交換器の回転数可変な室内送風機と、室外熱交換器の回転数可変な室外送風機と、外気温度ｔａを検出する外気温度センサーと、暖房運転時には蒸発器として機能する室外熱交換器の温度ｔｅを検出する蒸発温度センサーと、外気温度センサーが検出した外気温度ｔａと蒸発温度センサーが検出した室外熱交換器の温度ｔｅを受信するとともに、インバータ圧縮機の回転数と室内送風機の回転数と室外送風機の回転数に対応した除霜開始温度差Δｔｄが予め設定された制御手段と、を備え、制御手段が、外気温度ｔａと室外熱交換器の温度ｔｅの差ｔａ−ｔｅである温度差Δｔを算出し、この算出した温度差Δｔと、その時のインバータ圧縮機の回転数と室内送風機の回転数と室外送風機の回転数に対応した除霜開始温度差Δｔｄと、を比較し、Δｔ＞Δｔｄであり、かつ室外熱交換器の温度ｔｅが予め設定された着霜温度よりも低い場合に、四方弁を切換えて、インバータ圧縮機から吐出された暖かい冷媒を室内熱交換器に流す暖房運転から室外熱交換器に流す除湿運転に移行させるものである。
【００１４】
また、この発明の空気調和機においては、制御手段が、温度差Δｔが除霜開始温度差Δｔｄより高い状態が所定時間継続された場合に、暖房運転から除霜運転に移行させるものである。
【００１８】
また、この発明の空気調和機においては、回転数可変なインバータ圧縮機、四方弁、室内熱交換器、膨張機構、室外熱交換器が順次配管で接続されて構成され、室内を暖める当該空気調和機の暖房運転にはインバータ圧縮機から吐出された暖かい冷媒が四方弁により室内熱交換器から膨張機構と室外熱交換器に順次流れる冷凍サイクルと、室内熱交換器の回転数可変な室内送風機と、室外熱交換器の回転数可変な室外送風機と、外気温度ｔａを検出する外気温度センサーと、暖房運転時には蒸発器として機能する室外熱交換器の温度ｔｅを検出する蒸発温度センサーと、外気温度センサーが検出した外気温度ｔａと蒸発温度センサーが検出した室外熱交換器の温度ｔｅを受信する制御手段と、を備え、制御手段が、外気温度ｔａと室外熱交換器の温度ｔｅの差ｔａ−ｔｅである温度差Δｔの変化率を演算し、この演算した温度差Δｔの変化率が室外熱交換器の温度ｔｅを変化させる因子となる当該空気調和機の回転数可変な機器の回転数に対応して予め設定された変化率以上になった時に、四方弁を切換えて、インバータ圧縮機から吐出された暖かい冷媒を室内熱交換器に流す暖房運転から室外熱交換器に流す除霜運転に移行させるものである。
【００１９】
また、この発明の空気調和機においては、制御手段が、室外熱交換器の温度ｔｅが予め設定された除霜終了温度ｔｆより高くなった時には、除霜運転を終了させるものである。
【００２０】
【発明の実態の形態】
実施の形態１．
以下に、この発明の実施の形態１ついて図１を用いながら説明する。
なお、この図は空気調和機の概略構成図であり、この図に示すように、インバータ圧縮機１、四方弁２、室外熱交換器３、膨張機構（電子制御式膨張弁）４、室内熱交換器５を順次配管で接続して冷凍サイクルを構成し、室内を暖める時、圧縮機から吐出された暖かい冷媒を四方弁２により室内熱交換器５から膨張機構４、及び室外熱交換器３に順次流し、室内を暖める暖房運転を行う。
【００２１】
しかし、この暖房運転を継続して、外気温が低く（例えば、３℃以下）になった時、蒸発器として機能する室外熱交換器３に霜が付き、外気が熱交換器フィンの間を流れなくなり、熱交換能力の低下により蒸発温度が低下し、暖房能力が低下するので、この霜を解かす運転、即ち、除霜運転を行うものの、この除霜運転を余り速く行うと、少ない着霜状態で除霜運転を行うため、無駄なエネルギーを消費する。また逆に、余り遅く行うと、液バック現象を誘発して種々の問題を引き起こすこととなる。
【００２２】
従って、この発明においては、図２に示すように暖房時の除霜運転を行う。
即ち、まず、暖房運転（ステップＳ−１）が開始されると、制御手段はインバータ圧縮機回転速度Ｎc、室内送風機回転速度Ｎｒ、及び室外送風機回転速度Ｎa、並びに外気温度センサー８が検出する外気温度ｔaと、蒸発温度センサー９が検出する蒸発温度ｔeの信号を受信（ステップＳ−２）し、この受信した蒸発温度センサー９の蒸発温度ｔeが例えば、−１℃より高いか否か、即ち、室外熱交換器に霜が着霜する温度か否かを判断し、−１℃より高い場合には、室外熱交換器３に着霜していないと判断してステップＳ−１に戻り暖房運転を継続する。
【００２３】
しかし、蒸発温度ｔeが−１℃より低い場合には、この蒸発温度ｔeと、外気温度センサー８が検出する外気温度ｔaとの温度差Δｔ（=ｔａ-ｔe）を算出し、この算出結果のΔｔと、この時の圧縮機回転速度Ｎc、室内送風機回転速度Ｎｒ、室外送風機回転速度Ｎaにおける予め設定された除霜開始温度差Δｔdとを比較し、このステップＳ−４でΔｔ＞Δｔdであれば、ステップＳ−５に進み、デフロスト運転を行う。
なお、ステップＳ−４でΔｔ≦Δｔdの時はステップＳ−１に戻り、暖房運転を継続して、前述したと同じ動作を繰り返す。
【００２４】
また、前述のステップＳ−５のデフロスト（除霜）運転で、圧縮機から吐出された暖かい冷媒が四方弁２の切換えにより室外熱交換器３に流れ、除霜運転（冷房運転）が行われ、室外熱交換器３の温度ｔeが予め設定された除霜終了温度ｔｆになった時、即ち、ｔｅ＞ｔｆとなった時、室外熱交換器３に付着した霜が融けて無くなったと判断（ステップＳ−６）してデフロスト運転を終了し、再びステップＳ−１に戻り、再び同じ動作を繰り返す。
しかし、ｔｅ≦ｔｆの時は、ステップＳ−５のデフロスト運転が継続され、その後再びステップＳ−６の判断がなされ、同じ動作を繰り返す。
【００２５】
また、前述のステップＳ−３で、蒸発温度センサー９の蒸発温度ｔeが−１℃より高いか否か、即ち、室外熱交換器３に霜が着霜する温度か否かを判断するのは、外気温度が高く、霜が付かない−１℃以上の蒸発温度ｔeを維持しているにも関わらず、例えば、室外熱交換器３の周囲外気の温度が外気の流れによってショートサイク等を起し、蒸発温度が低下して外気温度ｔａと蒸発温度ｔeとの温度差Δｔが大きくなり、誤って除霜運転に移行したり、或いは暖かい空気が何らかの原因で室外熱交換器３へ瞬間的に流れ、温度差Δｔが大きくなり、誤って除霜運転に移行したりするのを防ぐためである。
【００２６】
また、このような誤った判断を誘起させる現象は室外熱交換器３の温度が−１℃以下の着霜時にも起こると考えられるので、このような現象を的確に捕らえ、精度良く除霜運転を行うためには、外気温度ｔａと蒸発温度ｔeとの温度差ΔｔがΔｔd以下となっても、直ちに除霜運転に移行せずに、所定時間、例えば１分以上、その状態を継続した時に、除霜運転に移行するようにすると良い。
【００２７】
また、前述の除霜運転制御因子として、何故に、検出温度ｔeと外気温度ｔａとの温度差Δｔを用いたかについて説明する。
まず、一般的に、室外熱交換器３に付着する霜の量は、室外熱交換器３の温度と、この室外熱交換器３を通過する外気の温・湿度によって決まる。
【００２８】
しかし、前述した室外熱交換器３の温度は、圧縮機の回転数、及び室内熱交換器５の室内送風機５ａの回転数が高ければ高いほど、或いは、室外熱交換器３の室外送風機３ａの回転数が低ければ低いほど、低い温度となり、外気温度との温度差が大きくなるため、着霜し易くなり、しかも、この着霜が多くなればなるほど熱交換能力が低下し、図３に示すように、蒸発温度が低下して、益々着霜し易くなり、相乗的に温度低下をきたすため、室外熱交換器３の温度ｔｅから着霜量を判断することは非常に有効である。
【００２９】
一方、この室外熱交換器３の温度は、前述したように、圧縮機の回転数や、室内熱交換器送風機５ａ又は室外熱交換器送風機３ａの回転数、或いはここを通過する外気温度によっても変化するものであるから、これらの因子、即ち、図４から６に示した全因子を考慮して判断することが必要となる。
言い換えれば、これら全ての因子を考慮した図７に基づいて着霜量を判断することになる。
なお、この図のファン速Ｈｉは送風機回転数の最大値を示し、ファン速Ｍｅは送風機回転数の中央値を示し、ファン速Ｌｏ送風機回転数の最小値を示す
【００３０】
また、これらの因子のうち、例えば、室外熱交換器３の送風機のファン速が可変しない時は、その因子によって室外熱交換器の蒸発温度は変化しないのであるから、その因子を判断対象因子から外すこととなるので、その時は、圧縮機の回転数と室内熱交換器の送風機の回転数における外気温度と室外熱交換器の温度との温度差Δｔが予め設定された除霜開始温度差Δｔdになったか否か、即ち、ΔｔとΔｔdとを比較して、Δｔ＞Δｔdであれば、デフロスト運転を行い、Δｔ≦Δｔdの時は、暖房運転を行うこととなる。
【００３１】
次に、前述した全ての蒸発温度因子を考慮して着霜状態を把握しても、どの着霜タイミングで除霜運転を行うかによって、暖房能力も、消費電力も相違するので、この点について図８、９を用いながら具体的に説明する。
【００３２】
まず、図９に示すように、着霜量の少ないレベル１で除霜運転を開始すると、除霜運転が頻繁に行われ、暖房運転時間に対する除霜運転時間の割合が大きくなり、暖房時間が短くなるため、暖房能力が低下すると共に、除霜運転毎に室外熱交換器３の温度を上げるためのエネルギーが必要となるため、無駄なエネルギーを消費することになる。
【００３３】
また一方、着霜量の多いレベル３で除霜運転を開始するようにすると、図９に示すように、１サイクル当たりの暖房運転時間は長くなるものの、着霜による暖房能力の低下が生じ、無駄なエネルギーを消費するだけでなく、この着霜によって室外熱交換器内の液冷媒が蒸発しないで圧縮機へ戻る、所謂液バックが発生し、この液バックによる各種トラブルが発生すると共に、着霜量が多いため、デフロスト運転時間、即ち冷房運転が長くなるため、室内の人が寒さを感じることとなる。
【００３４】
従って、室外熱交換器３が目詰まりを起す前、即ち、図８のレベル２の着霜量における蒸発温度で除霜運転を開始するように、言い換えれば、外気温度ｔａと検出温度ｔｅとの温度差Δｔが予め設定された除霜開始温度差Δｔdになった時に、除霜運転を開始するようにすると、目詰まりによる暖房能力の低下を防止しながら効率良く運転するようになるため、暖房能力に優れ、エネルギーロスも少ない経済的な空気調和機を得ることができる。
【００３５】
また、以上の説明においては、外気温度ｔａと検出温度ｔｅとの温度差Δｔが予め設定された除霜開始温度差Δｔdになった時に除霜運転を開始するようにしたが、蒸発器として機能する室外熱交換器３が目詰まりする前に暖房時の除霜運転を開始するその他のやり方について次に説明する。
【００３６】
まず、このやり方は、前述と同様に、前記室外熱交換器の温度とその周囲の外気温度との温度差を検出し、この検出した温度差の変化率を演算し、この演算した変化率が予め設定された変化率以上か否かを判断し、以上の時は、暖房運転から除霜運転に切り換え、以下の時は暖房運転を継続するものである。
【００３７】
即ち、暖房運転が行われ、霜が室外熱交換器３に付着し、目詰まりすると、室外熱交換器３の熱交換能力の大幅に低下し、室外熱交換器３の蒸発温度が図３に示すように急激に低下する。その結果、暖房能力も図８に示すように急激に低下すると共に、室外熱交換器の温度とその周囲の外気温度との温度差が大きく変化するので、この現象を利用して除霜可否を判断する。
言い換えれば、室外熱交換器の温度とその周囲の外気温度との温度差の変化率が予め設定された変化率以上となった時には、暖房運転から除霜運転に切り換えて運転し、予め設定された変化率以下の時には、暖房運転を継続する。
【００３８】
また、この時も、蒸発温度は、前述したように、空気調和機の可変速機器である圧縮機１の回転数や、室内熱交換器５の送風機の回転数や、室外熱交換器３の送風機の回転数が変化すれば、変化するので、これら空調機器の回転数変化による蒸発温度の変化を考慮しながら判断することとなる。
【００３９】
なお、前述の除霜運転が行われ、室外熱交換器の温度が予め設定された除霜終了温度以上になった時には、除霜運転を終了して、暖房運転に移行する。
【００４０】
以上のように、室外熱交換器の温度とその周囲の外気温度との温度差の変化率に基づいて、除霜運転のタイミングを判断するようにすると、更に的確に室外熱交換器に付着した着霜量を判断して除霜運転をするようになため、経済的な空気調和機が得られる。
【００４１】
【発明の効果】
以上説明したように、この発明の空気調和機においては、回転数可変なインバータ圧縮機、四方弁、室内熱交換器、膨張機構、室外熱交換器が順次配管で接続されて構成され、室内を暖める当該空気調和機の暖房運転時にはインバータ圧縮機から吐出された暖かい冷媒が四方弁により室内熱交換器から膨張機構と室外熱交換器に順次流れる冷凍サイクルと、室内熱交換器の回転数可変な室内送風機と、室外熱交換器の回転数可変な室外送風機と、外気温度ｔａを検出する外気温度センサーと、暖房運転時には蒸発器として機能する室外熱交換器の温度ｔｅを検出する蒸発温度センサーと、外気温度センサーが検出した外気温度ｔａと蒸発温度センサーが検出した室外熱交換器の温度ｔｅを受信するとともに、インバータ圧縮機の回転数と室内送風機の回転数と室外送風機の回転数に対応した除霜開始温度差Δｔｄが予め設定された制御手段と、を備え、制御手段が、外気温度ｔａと室外熱交換器の温度ｔｅの差ｔａ−ｔｅである温度差Δｔを算出し、この算出した温度差Δｔと、その時のインバータ圧縮機の回転数と室内送風機の回転数と室外送風機の回転数に対応した除霜開始温度差Δｔｄと、を比較し、Δｔ＞Δｔｄなる状態が所定時間継続された場合に、四方弁を切換えて、インバータ圧縮機から吐出された暖かい冷媒を室内熱交換器に流す暖房運転から室外熱交換器に流す除湿運転に移行させるので、室外熱交換器の着霜状態を適切に判断し適正なタイミングで除湿運転が行われるとともに、外乱要因により一時的にΔｔ＞Δｔｄとなっても暖房運転から除湿運転には移行しないため、暖房性能に優れ、経済的で、信頼性の高い空気調和機が得られる。
【００４２】
また、この発明の空気調和機においては、回転数可変なインバータ圧縮機、四方弁、室内熱交換器、膨張機構、室外熱交換器が順次配管で接続されて構成され、室内を暖める当該空気調和機の暖房運転時にはインバータ圧縮機から吐出された暖かい冷媒が四方弁により室内熱交換器から膨張機構と室外熱交換器に順次流れる冷凍サイクルと、室内熱交換器の回転数可変な室内送風機と、室外熱交換器の回転数可変な室外送風機と、外気温度ｔａを検出する外気温度センサーと、暖房運転時には蒸発器として機能する室外熱交換器の温度ｔｅを検出する蒸発温度センサーと、外気温度センサーが検出した外気温度ｔａと蒸発温度センサーが検出した室外熱交換器の温度ｔｅを受信するとともに、インバータ圧縮機の回転数と室内送風機の回転数と室外送風機の回転数に対応した除霜開始温度差Δｔｄが予め設定された制御手段と、を備え、制御手段が、外気温度ｔａと室外熱交換器の温度ｔｅの差ｔａ−ｔｅである温度差Δｔを算出し、この算出した温度差Δｔと、その時のインバータ圧縮機の回転数と室内送風機の回転数と室外送風機の回転数に対応した除霜開始温度差Δｔｄと、を比較し、Δｔ＞Δｔｄであり、かつ室外熱交換器の温度ｔｅが予め設定された着霜温度よりも低い場合に、四方弁を切換えて、インバータ圧縮機から吐出された暖かい冷媒を室内熱交換器に流す暖房運転から室外熱交換器に流す除湿運転に移行させるので、室外熱交換器の着霜状態を適切に判断し適正なタイミングで除湿運転が行われるとともに、外気温度が高く、室外熱交換器の温度ｔｅが着霜温度より高い温度を維持しているにも関わらず、外気の流れ等が原因で温度差Δｔが大きくなってしまっても暖房運転から除湿運転には移行しないため、暖房性能に優れ、経済的で、信頼性の高い空気調和機が得られる。
【００４４】
また、この発明の空気調和機においては、制御手段が、温度差Δｔが除霜開始温度差Δｔｄより高い状態が所定時間継続された場合に、暖房運転から除霜運転に移行させるので、特に、外乱要因により一時的にΔｔ＞Δｔｄとなっても暖房運転から除霜運転には移行しないため、信頼性の高い空気調和機が得られる。
【００４８】
また、この発明の空気調和機においては、回転数可変なインバータ圧縮機、四方弁、室内熱交換器、膨張機構、室外熱交換器が順次配管で接続されて構成され、室内を暖める当該空気調和機の暖房運転にはインバータ圧縮機から吐出された暖かい冷媒が四方弁により室内熱交換器から膨張機構と室外熱交換器に順次流れる冷凍サイクルと、室内熱交換器の回転数可変な室内送風機と、室外熱交換器の回転数可変な室外送風機と、外気温度ｔａを検出する外気温度センサーと、暖房運転時には蒸発器として機能する室外熱交換器の温度ｔｅを検出する蒸発温度センサーと、外気温度センサーが検出した外気温度ｔａと蒸発温度センサーが検出した室外熱交換器の温度ｔｅを受信する制御手段と、を備え、制御手段が、外気温度ｔａと室外熱交換器の温度ｔｅの差ｔａ−ｔｅである温度差Δｔの変化率を演算し、この演算した温度差Δｔの変化率が室外熱交換器の温度ｔｅを変化させる因子となる当該空気調和機の回転数可変な機器の回転数に対応して予め設定された変化率以上になった時に、四方弁を切換えて、インバータ圧縮機から吐出された暖かい冷媒を室内熱交換器に流す暖房運転から室外熱交換器に流す除霜運転に移行させるので、的確に室外熱交換器に付着した着霜量を判断して除霜運転に移行するようになるため、暖房性能に優れ、経済的な空気調和機が得られる。
【００４９】
また、この発明の空気調和機においては、制御手段が、室外熱交換器の温度ｔｅが予め設定された除霜終了温度ｔｆより高くなった時には、除霜運転を終了させるので、余分なエネルギーを消費することなく、室外熱交換器の状態を適切にするため、経済的な空気調和機が得られる。
【図面の簡単な説明】
【図１】この発明の実施の形態１における空気調和機の概略構成図である。
【図２】この発明の実施の形態１における暖房運転時の制御フロー図である。
【図３】この発明の実施の形態１における着霜量に対する蒸発温度ｔｅの変化図である。
【図４】この発明の実施の形態１における着霜量に対する蒸発温度と外気温度との温度差Δｔと圧縮機の回転速度との関係を示した関係図である。
【図５】この発明の実施の形態１における圧縮機の回転速度と室内送風機回転速度との関係に対する室外熱交換器の蒸発温度の変化図である。
【図６】この発明の実施の形態１における圧縮機の回転速度と室外送風機回転速度との関係に対する室外熱交換器の蒸発温度の変化図である。
【図７】この発明の実施の形態１における圧縮機の回転速度、室外送風機回転速度、及び室内送風機回転速度の関係に対する室外熱交換器の蒸発温度の変化図である。
【図８】この発明の実施の形態１における着霜レベルと暖房能力との関係を示した図である。
【図９】この発明の実施の形態１における着霜レベルと暖房能力との関係を示した関係図である。
【符号の説明】
１圧縮機、２四方弁、３室外熱交換器、４膨張機構、５室内熱交換器、６室外送風機、７室内送風機、８外気温度センサー、９蒸発温度センサー、１０制御手段。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air conditioner that performs a defrosting operation during heating operation.
[0002]
[Prior art]
In a conventional air conditioner, a refrigeration cycle is configured by connecting a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an expansion mechanism (electronically controlled expansion valve) 4, and an indoor heat exchanger 5 in order. When the room is warmed, the refrigerant from the compressor 1 is sequentially flowed from the indoor heat exchanger 5 to the expansion mechanism 4 and the outdoor heat exchanger 3 by the four-way valve 2 to perform a heating operation for warming the room.
[0003]
However, if this heating operation is continued and the outside air temperature decreases, the outdoor heat exchanger functioning as an evaporator will be frosted, the outside air will not flow between the fins of the heat exchanger, the evaporation temperature will drop, Since the capacity decreases, this defrosting operation, that is, defrosting operation is performed. However, if this defrosting operation is performed too quickly or too slowly, useless energy is consumed or the liquid back is discharged. Inducing phenomena will cause various problems.
[0004]
A typical conventional air conditioner that takes this into consideration is disclosed in Japanese Patent Application Laid-Open No. 61-153332.
However, in this case, when the frost adhering to the evaporator of the outdoor heat exchanger is defrosted, the defrosting timing is determined by the detection result of the outside temperature sensor 8 for detecting the outside temperature and the detection result of the evaporation temperature sensor 9 for detecting the evaporation temperature. In addition, when the temperature difference between the outside air temperature and the evaporation temperature at a predetermined number of rotations of the compressor exceeds a predetermined temperature difference, a defrosting operation is performed to defrost the frost. .
[0005]
However, when the defrosting operation is performed according to only the evaporation temperature at the outside air temperature for each rotation speed of the compressor, the evaporation temperature is not only the rotation speed of the compressor, but also the rotation speed of the outdoor fan or the indoor fan. Therefore, accurate defrosting operation cannot be performed.
That is, for example, when the rotational speed of the outdoor fan increases or the rotational speed of the indoor fan decreases, the evaporation temperature decreases, and the temperature difference between the outside air temperature and the evaporation temperature becomes equal to or greater than a predetermined temperature difference, Even in a state where frost is not so much adhered, it is determined that the outdoor heat exchanger has been frosted and the defrosting operation is performed, so that useless energy is consumed.
[0006]
On the other hand, the evaporation temperature rises due to the increase in the rotation speed of the outdoor fan or the decrease in the rotation speed of the indoor fan, although many frosts are attached and the outdoor heat exchanger is clogged. Therefore, when the temperature difference between the outside air temperature and the evaporation temperature is smaller than the predetermined temperature difference, it is determined that there is no need to perform the defrosting operation and the operation is performed in a clogged state. The compressor may be damaged by the back.
[0007]
In such control, even when the evaporation temperature (for example, −1 ° C. or higher) in which defrosting is not required is performed, the temperature of the outdoor air around the outdoor heat exchanger 3 is reduced by a short cycle due to the flow of the outdoor air. When the temperature difference between the outside air temperature and the evaporation temperature is greater than or equal to a predetermined temperature difference, useless energy is consumed because the defrosting operation is performed.
[0008]
In addition, as another conventional example, there is one as disclosed in JP-A-60-233435 which does not have an inverter device.
[0009]
[Problems to be solved by the invention]
As described above, the conventional air conditioners have the problems of consuming unnecessary energy and causing troubles due to a decrease in heating capacity and liquid back.
[0010]
The present invention has been made to solve the above-described problems, and it is an object of the present invention to appropriately perform a defrosting operation during heating operation, to obtain an air conditioner that has excellent heating performance, is economical, and has high reliability. And
[0011]
[Means for Solving the Problems]
In the air conditioner of the present invention, the variable rotational speed of the inverter compressor, four-way valve, an indoor heat exchanger, an expansion mechanism, an outdoor heat exchanger is constituted by connecting sequentially piping, the air conditioner Ru warm room A refrigeration cycle in which warm refrigerant discharged from the inverter compressor at the time of heating operation flows sequentially from the indoor heat exchanger to the expansion mechanism and the outdoor heat exchanger by a four-way valve, and an indoor blower with a variable number of rotations of the indoor heat exchanger, An outdoor blower with a variable number of revolutions of the outdoor heat exchanger, an outdoor air temperature sensor that detects the outdoor air temperature ta, an evaporation temperature sensor that detects the temperature te of the outdoor heat exchanger that functions as an evaporator during heating operation, and an outdoor air temperature sensor Receives the outdoor air temperature ta detected by the evaporative temperature sensor and the temperature te of the outdoor heat exchanger detected by the evaporating temperature sensor, and the rotational speed of the inverter compressor, the rotational speed of the indoor fan, and the outdoor And a control means for defrosting start temperature difference Δtd corresponding to the rotational speed of the wind machine has been set in advance, the control means is a difference ta-te temperature te of the outside air temperature ta and the outdoor heat exchanger temperature difference Δt is calculated and compared with the temperature difference Δt which is the calculated, and dividing the defrosting start temperature difference Δtd corresponding to the rotational speed of the inverter the rotation speed of the rotation speed of the compressors and the chamber feeding air blower and the outdoor blower at that time , Delta] t> if Δtd made state is continued for a predetermined time, switches the four-way valve, flow from the warm Boun rolling flowing warm refrigerant discharged from the inverter compressor to the indoor heat exchanger to the outdoor heat exchanger dehumidifying operation Is to be transferred to .
[0012]
In the air conditioner of the present invention, the variable rotational speed of the inverter compressor, four-way valve, an indoor heat exchanger, an expansion mechanism, an outdoor heat exchanger is constituted by connecting sequentially pipe, the air Ru warm room A refrigeration cycle in which warm refrigerant discharged from the inverter compressor flows sequentially from the indoor heat exchanger to the expansion mechanism and the outdoor heat exchanger by a four-way valve during the heating operation of the conditioner, and an indoor blower with a variable number of rotations of the indoor heat exchanger An outdoor fan with a variable number of revolutions of the outdoor heat exchanger, an outdoor air temperature sensor that detects the outdoor air temperature ta, an evaporation temperature sensor that detects the temperature te of the outdoor heat exchanger that functions as an evaporator during heating operation, While receiving the outdoor temperature ta detected by the temperature sensor and the temperature te of the outdoor heat exchanger detected by the evaporation temperature sensor, the rotation speed of the inverter compressor and the rotation speed of the indoor fan And a control means for defrosting start temperature difference Δtd corresponding to the rotational speed of the outdoor fan is set in advance, the control means, the temperature difference is the difference ta-te temperature te of the outside air temperature ta and the outdoor heat exchanger calculating a Delta] t, compares the temperature difference Delta] t was the calculated and, removing frost start temperature difference Δtd corresponding to the rotational speed of the inverter the rotation speed of the rotation speed of the compressors and the chamber blower and the chamber outside air blower at that time Then, when Δt> Δtd and the temperature te of the outdoor heat exchanger is lower than the preset frosting temperature, the four-way valve is switched to allow the warm refrigerant discharged from the inverter compressor to flow into the indoor heat exchanger. it is intended to shift the dehumidifying operation flow to the outdoor heat exchanger from warm Boun rolling flow in.
[0014]
In the air conditioner of the present invention, the control means, when the temperature difference Δt state higher than defrost start temperature difference Δtd is continued for a predetermined time, but to shift the defrosting operation from heating OPERATION is there.
[0018]
In the air conditioner of the present invention, the variable rotational speed of the inverter compressor, four-way valve, an indoor heat exchanger, an expansion mechanism, an outdoor heat exchanger is constituted by connecting sequentially pipe, the sky Ru warm room and sequentially flows refrigeration cycle from the indoor heat exchanger to the expansion mechanism and the outdoor heat exchanger warm refrigerant discharged from the inverter compressor by the four-way valve to the warm Boun rotation of air conditioner, variable rotational speed of the indoor heat exchanger Indoor air blower, outdoor heat exchanger with variable rotation speed of outdoor heat exchanger, outdoor air temperature sensor for detecting outdoor air temperature ta, and evaporation temperature sensor for detecting temperature te of the outdoor heat exchanger functioning as an evaporator during heating operation When, and a control means for the outside air temperature ta and the evaporation temperature sensor outside air temperature sensor detects receives the temperature te of the outdoor heat exchanger is detected, the control means, outside air temperature ta and the outdoor heat exchanger Calculates the rate of change of the temperature difference Δt which is a difference ta-te temperature te of the rotational speed of the air conditioner rate of change of the calculated temperature difference Δt becomes factors make vary the temperature te of the outdoor heat exchanger When the rate of change exceeds a preset change rate corresponding to the number of rotations of the variable device, the four-way valve is switched to allow the warm refrigerant discharged from the inverter compressor to flow to the indoor heat exchanger, from the heating operation to the outdoor heat exchange. It is made to transfer to the defrost operation which flows into a container .
[0019]
In the air conditioner of the present invention, the control means, when the temperature te chamber outside the heat exchanger is higher than the preset defrost completion temperature tf is it shall terminate the defrosting operation.
[0020]
[Form of the present invention]
Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to FIG.
In addition, this figure is a schematic block diagram of an air conditioner. As shown in this figure, the inverter compressor 1, the four-way valve 2, the outdoor heat exchanger 3, the expansion mechanism (electronically controlled expansion valve) 4, the indoor heat When the exchanger 5 is sequentially connected by piping to form a refrigeration cycle and the room is warmed, the warm refrigerant discharged from the compressor is discharged from the indoor heat exchanger 5 to the expansion mechanism 4 and the outdoor heat exchanger 3 by the four-way valve 2. The heating operation is performed in order to warm the room.
[0021]
However, when this heating operation is continued, when the outside air temperature becomes low (for example, 3 ° C. or less), the outdoor heat exchanger 3 functioning as an evaporator is frosted, and the outside air passes between the heat exchanger fins. Since the evaporating temperature is lowered due to a decrease in the heat exchange capacity and the heating capacity is lowered due to the loss of the heat exchange capacity, the operation for defrosting, that is, the defrosting operation is performed. Since defrosting operation is performed in a frost state, useless energy is consumed. On the contrary, if it is performed too late, a liquid back phenomenon is induced and various problems are caused.
[0022]
Therefore, in this invention, as shown in FIG. 2, the defrosting operation at the time of heating is performed.
That is, first, when the heating operation (step S-1) is started, the control means detects the inverter compressor rotation speed Nc, the indoor fan rotation speed Nr, the outdoor fan rotation speed Na, and the outside air detected by the outside air temperature sensor 8. A signal of the temperature ta and the evaporation temperature te detected by the evaporation temperature sensor 9 is received (step S-2), and whether or not the received evaporation temperature te of the evaporation temperature sensor 9 is higher than −1 ° C., for example. Then, it is determined whether or not the temperature at which frost is formed on the outdoor heat exchanger. If the temperature is higher than -1 ° C, it is determined that the outdoor heat exchanger 3 is not frosted, and the process returns to step S-1 for heating. Continue driving.
[0023]
However, when the evaporation temperature te is lower than −1 ° C., a temperature difference Δt (= ta−te) between the evaporation temperature te and the outside air temperature ta detected by the outside air temperature sensor 8 is calculated. Δt is compared with a preset defrosting start temperature difference Δtd at the compressor rotation speed Nc, the indoor fan rotation speed Nr, and the outdoor fan rotation speed Na at this time, and if Δt> Δtd in step S-4, If so, the process proceeds to step S-5 to perform the defrost operation.
When Δt ≦ Δtd in step S-4, the process returns to step S-1, the heating operation is continued, and the same operation as described above is repeated.
[0024]
In the defrosting (defrosting) operation in step S-5 described above, the warm refrigerant discharged from the compressor flows into the outdoor heat exchanger 3 by switching the four-way valve 2, and the defrosting operation (cooling operation) is performed. When the temperature te of the outdoor heat exchanger 3 reaches a preset defrosting end temperature tf, that is, when te> tf, it is determined that the frost attached to the outdoor heat exchanger 3 has melted and disappeared ( Step S-6) ends the defrosting operation, returns to step S-1 again, and repeats the same operation again.
However, when te ≦ tf, the defrost operation in step S-5 is continued, and then the determination in step S-6 is made again, and the same operation is repeated.
[0025]
In step S-3 described above, it is determined whether or not the evaporation temperature te of the evaporation temperature sensor 9 is higher than −1 ° C., that is, whether or not it is a temperature at which frost forms on the outdoor heat exchanger 3. Although the outside air temperature is high and the evaporating temperature te of −1 ° C. or higher is maintained, the temperature of the outside air around the outdoor heat exchanger 3 causes a short cycle or the like due to the flow of outside air. As a result, the evaporating temperature decreases and the temperature difference Δt between the outside air temperature ta and the evaporating temperature te increases, and the defrosting operation is mistakenly performed, or the warm air is instantaneously transferred to the outdoor heat exchanger 3 for some reason. This is to prevent the flow and temperature difference Δt from becoming large and erroneously shifting to the defrosting operation.
[0026]
Moreover, since the phenomenon which induces such an erroneous judgment is considered to occur even when the temperature of the outdoor heat exchanger 3 is frosted at −1 ° C. or less, such a phenomenon is accurately captured and defrosting operation is performed with high accuracy. When the temperature difference Δt between the outside air temperature ta and the evaporation temperature te is equal to or less than Δtd, the state is continued for a predetermined time, for example, 1 minute or more without immediately proceeding to the defrosting operation. It is good to shift to defrosting operation.
[0027]
The reason why the temperature difference Δt between the detected temperature te and the outside air temperature ta is used as the above-described defrosting operation control factor will be described.
First, generally, the amount of frost adhering to the outdoor heat exchanger 3 is determined by the temperature of the outdoor heat exchanger 3 and the temperature and humidity of the outside air passing through the outdoor heat exchanger 3.
[0028]
However, the temperature of the outdoor heat exchanger 3 described above is higher as the rotation speed of the compressor and the rotation speed of the indoor fan 5a of the indoor heat exchanger 5 is higher, or the temperature of the outdoor fan 3a of the outdoor heat exchanger 3 is higher. The lower the number of revolutions, the lower the temperature, and the greater the temperature difference from the outside air temperature, so that frost formation becomes easier, and the more this frost formation, the lower the heat exchange capability, as shown in FIG. As described above, since the evaporation temperature is lowered and frost formation is more likely to occur and the temperature is reduced synergistically, it is very effective to determine the frost formation amount from the temperature te of the outdoor heat exchanger 3.
[0029]
On the other hand, the temperature of the outdoor heat exchanger 3 depends on the rotational speed of the compressor, the rotational speed of the indoor heat exchanger blower 5a or the outdoor heat exchanger blower 3a, or the outside air temperature passing therethrough as described above. Since it changes, it is necessary to judge in consideration of these factors, that is, all the factors shown in FIGS.
In other words, the amount of frost formation is determined based on FIG. 7 considering all these factors.
In this figure, the fan speed Hi indicates the maximum value of the fan speed, the fan speed Me indicates the median value of the fan speed, and indicates the minimum value of the fan speed Lo fan speed.
Further, among these factors, for example, when the fan speed of the blower of the outdoor heat exchanger 3 is not variable, the evaporation temperature of the outdoor heat exchanger does not change depending on the factor. At that time, a defrosting start temperature difference Δtd in which the temperature difference Δt between the outside air temperature and the outdoor heat exchanger temperature at the rotation speed of the compressor and the rotation speed of the blower of the indoor heat exchanger is set in advance. If Δt> Δtd, a defrost operation is performed, and if Δt ≦ Δtd, a heating operation is performed.
[0031]
Next, even if the frost state is grasped in consideration of all the evaporation temperature factors described above, the heating capacity and the power consumption differ depending on the frost timing at which the frosting operation is performed. This will be specifically described with reference to FIGS.
[0032]
First, as shown in FIG. 9, when the defrosting operation is started at level 1 where the amount of frost formation is small, the defrosting operation is frequently performed, the ratio of the defrosting operation time to the heating operation time is increased, and the heating time is increased. Since the heating capacity is shortened, energy for raising the temperature of the outdoor heat exchanger 3 is required for each defrosting operation, and wasteful energy is consumed.
[0033]
On the other hand, if the defrosting operation is started at level 3 where the amount of frost formation is large, the heating operation time per cycle becomes longer as shown in FIG. In addition to consuming wasteful energy, the frosting causes the liquid refrigerant in the outdoor heat exchanger to return to the compressor without evaporating, so-called liquid back occurs. Since the amount of frost is large, the defrosting operation time, that is, the cooling operation becomes long, so that the person in the room feels cold.
[0034]
Therefore, before the outdoor heat exchanger 3 is clogged, that is, so as to start the defrosting operation at the evaporation temperature at the frosting amount at level 2 in FIG. 8, in other words, between the outside air temperature ta and the detected temperature te. If the defrosting operation is started when the temperature difference Δt reaches the preset defrosting start temperature difference Δtd, the heating operation is efficiently performed while preventing the heating capacity from being lowered due to clogging. An economical air conditioner with excellent capacity and low energy loss can be obtained.
[0035]
In the above description, the defrosting operation is started when the temperature difference Δt between the outside air temperature ta and the detected temperature te reaches a preset defrosting start temperature difference Δtd. Next, another method for starting the defrosting operation during heating before the outdoor heat exchanger 3 to be clogged will be described.
[0036]
First, as described above, this method detects the temperature difference between the temperature of the outdoor heat exchanger and the ambient air temperature around it, calculates the change rate of the detected temperature difference, and the calculated change rate is It is determined whether or not the rate of change is equal to or higher than a preset change rate. In the above case, the heating operation is switched to the defrosting operation, and in the following cases, the heating operation is continued.
[0037]
That is, when a heating operation is performed and frost adheres to the outdoor heat exchanger 3 and becomes clogged, the heat exchange capacity of the outdoor heat exchanger 3 is greatly reduced, and the evaporation temperature of the outdoor heat exchanger 3 is shown in FIG. It decreases rapidly as shown. As a result, the heating capacity also decreases rapidly as shown in FIG. 8, and the temperature difference between the temperature of the outdoor heat exchanger and the ambient air temperature around it greatly changes. to decide.
In other words, when the change rate of the temperature difference between the temperature of the outdoor heat exchanger and the ambient outside air temperature is equal to or higher than the preset change rate, the operation is switched from the heating operation to the defrosting operation, and is set in advance. When the change rate is less than or equal to, the heating operation is continued.
[0038]
Also at this time, as described above, the evaporation temperature is the rotation speed of the compressor 1, which is a variable speed device of the air conditioner, the rotation speed of the blower of the indoor heat exchanger 5, and the outdoor heat exchanger 3. If the rotation speed of the blower changes, it will change, so that the determination will be made while taking into account the change in the evaporation temperature due to the change in the rotation speed of these air conditioners.
[0039]
In addition, when the above-mentioned defrosting operation is performed and the temperature of the outdoor heat exchanger becomes equal to or higher than a preset defrosting end temperature, the defrosting operation is ended and the operation is shifted to the heating operation.
[0040]
As described above, when the timing of the defrosting operation is judged based on the rate of change of the temperature difference between the temperature of the outdoor heat exchanger and the ambient outside air temperature, it adheres to the outdoor heat exchanger more accurately. Since the defrosting operation is performed by determining the amount of frost formation, an economical air conditioner can be obtained.
[0041]
【The invention's effect】
As described above, in the air conditioner of the present invention, the variable rotational speed of the inverter compressor, four-way valve, an indoor heat exchanger, an expansion mechanism, an outdoor heat exchanger is constituted by connecting sequentially piping, the room and sequentially flows refrigeration cycle from the indoor heat exchanger to the expansion mechanism and the outdoor heat exchanger during the heating operation of the air conditioner warm refrigerant discharged from the inverter compressor by the four-way valve Ru warmed, the rotation speed of the indoor heat exchanger A variable indoor blower, an outdoor blower with a variable rotation speed of the outdoor heat exchanger, an outdoor air temperature sensor that detects the outdoor air temperature ta, and an evaporation temperature that detects the temperature te of the outdoor heat exchanger that functions as an evaporator during heating operation The sensor, the outside air temperature ta detected by the outside air temperature sensor, and the temperature te of the outdoor heat exchanger detected by the evaporation temperature sensor are received. And a control means for speed and defrost start temperature difference Δtd corresponding to the rotational speed of the outdoor fan of the air blower is set in advance, the control means, the difference in temperature te of the outside air temperature ta and the outdoor heat exchanger ta- calculating a temperature difference Delta] t is a te, and the calculated temperature difference Delta] t, the defrost start temperature difference corresponding to the number of rotations of the outdoor fan rotational speed and the chamber feeding wind machine inverter compressors at that time compares the? td, the, Delta] t> if? td becomes state is continued for a predetermined time, it switches the four-way valve, an outdoor heat from warm Boun rolling flowing warm refrigerant discharged from the inverter compressor to the indoor heat exchanger Since the operation is shifted to the dehumidifying operation that flows through the exchanger, the frosting state of the outdoor heat exchanger is appropriately determined and the dehumidifying operation is performed at an appropriate timing, and even if Δt> Δtd temporarily due to disturbance factors, the heating operation is performed. I do not want to migrate to the dehumidifying operation from Because excellent heating performance, economical, reliable air conditioner is obtained.
[0042]
In the air conditioner of the present invention, the variable rotational speed of the inverter compressor, four-way valve, an indoor heat exchanger, an expansion mechanism, an outdoor heat exchanger is constituted by connecting sequentially pipe, the air Ru warm room A refrigeration cycle in which warm refrigerant discharged from the inverter compressor flows sequentially from the indoor heat exchanger to the expansion mechanism and the outdoor heat exchanger by a four-way valve during the heating operation of the conditioner, and an indoor blower with a variable number of rotations of the indoor heat exchanger An outdoor fan with a variable number of revolutions of the outdoor heat exchanger, an outdoor air temperature sensor that detects the outdoor air temperature ta, an evaporation temperature sensor that detects the temperature te of the outdoor heat exchanger that functions as an evaporator during heating operation, While receiving the outdoor temperature ta detected by the temperature sensor and the temperature te of the outdoor heat exchanger detected by the evaporation temperature sensor, the rotation speed of the inverter compressor and the rotation speed of the indoor fan And a control means for defrosting start temperature difference Δtd corresponding to the rotational speed of the outdoor fan is set in advance, the control means, the temperature difference is the difference ta-te temperature te of the outside air temperature ta and the outdoor heat exchanger calculating a Delta] t, compares the temperature difference Delta] t was the calculated and, removing frost start temperature difference Δtd corresponding to the rotational speed of the inverter the rotation speed of the rotation speed of the compressors and the chamber blower and the chamber outside air blower at that time Then, when Δt> Δtd and the temperature te of the outdoor heat exchanger is lower than the preset frosting temperature, the four-way valve is switched to allow the warm refrigerant discharged from the inverter compressor to flow into the indoor heat exchanger. since shifting to dehumidifying operation flow to the outdoor heat exchanger from warm Boun rolling flow in, along with appropriately determine and dehumidifying operation at an appropriate timing frosting state of the outdoor heat exchanger is performed, the outside air temperature is high, outdoor Heat exchanger temperature te is frost temperature Despite the fact that maintaining a high temperature, for such as outside air flow is not migrated to the dehumidifying operation from the heating operation also have become larger temperature difference Δt is due, excellent heating performance, economical, reliable A highly functional air conditioner can be obtained.
[0044]
In the air conditioner of the present invention, the control means, when the temperature difference Δt state higher than defrost start temperature difference Δtd is continued for a predetermined time, since shifting to the defrosting operation from heating OPERATION, in particular, since you do not want to migrate to the defrosting operation from the heating operation even if the temporary Ri by the disturbance factor becomes Δt> Δtd, reliable air conditioner can be obtained.
[0048]
In the air conditioner of the present invention, the variable rotational speed of the inverter compressor, four-way valve, an indoor heat exchanger, an expansion mechanism, an outdoor heat exchanger is constituted by connecting sequentially pipe, the sky Ru warm room and sequentially flows refrigeration cycle from the indoor heat exchanger to the expansion mechanism and the outdoor heat exchanger warm refrigerant discharged from the inverter compressor by the four-way valve to the warm Boun rotation of air conditioner, variable rotational speed of the indoor heat exchanger Indoor air blower, outdoor heat exchanger with variable rotation speed of outdoor heat exchanger, outdoor air temperature sensor for detecting outdoor air temperature ta, and evaporation temperature sensor for detecting temperature te of the outdoor heat exchanger functioning as an evaporator during heating operation When, and a control means for the outside air temperature ta and the evaporation temperature sensor outside air temperature sensor detects receives the temperature te of the outdoor heat exchanger is detected, the control means, outside air temperature ta and the outdoor heat exchanger Calculates the rate of change of the temperature difference Δt which is a difference ta-te temperature te of the rotational speed of the air conditioner rate of change of the calculated temperature difference Δt becomes factors make vary the temperature te of the outdoor heat exchanger When the rate of change exceeds a preset change rate corresponding to the number of rotations of the variable device, the four-way valve is switched to allow the warm refrigerant discharged from the inverter compressor to flow to the indoor heat exchanger, from the heating operation to the outdoor heat exchange. since shifting to the defrosting operation flow in vessels, precisely because ing as to determine frost quantity adhering to the outdoor heat exchanger proceeds to the defrosting operation, excellent heating performance, economical air conditioner Is obtained.
[0049]
In the air conditioner of the present invention, the control means, when the temperature te chamber outside the heat exchanger is higher than the preset defrost completion temperature tf is Runode terminates the defrosting operation, extra An economical air conditioner is obtained in order to make the state of the outdoor heat exchanger appropriate without consuming energy.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an air conditioner according to Embodiment 1 of the present invention.
FIG. 2 is a control flow diagram during heating operation in Embodiment 1 of the present invention.
FIG. 3 is a change diagram of the evaporation temperature te with respect to the amount of frost formation in Embodiment 1 of the present invention.
FIG. 4 is a relational diagram showing the relationship between the temperature difference Δt between the evaporation temperature and the outside air temperature with respect to the amount of frost formation in Embodiment 1 of the present invention and the rotational speed of the compressor.
FIG. 5 is a change diagram of the evaporation temperature of the outdoor heat exchanger with respect to the relationship between the rotation speed of the compressor and the rotation speed of the indoor fan in Embodiment 1 of the present invention.
FIG. 6 is a change diagram of the evaporation temperature of the outdoor heat exchanger with respect to the relationship between the rotation speed of the compressor and the rotation speed of the outdoor fan in Embodiment 1 of the present invention.
FIG. 7 is a change diagram of the evaporation temperature of the outdoor heat exchanger with respect to the relationship among the rotation speed of the compressor, the outdoor fan rotation speed, and the indoor fan rotation speed in Embodiment 1 of the present invention.
FIG. 8 is a diagram showing the relationship between the frost level and the heating capacity in Embodiment 1 of the present invention.
FIG. 9 is a relationship diagram showing the relationship between the frost level and the heating capacity in Embodiment 1 of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Compressor, 2 Four-way valve, 3 Outdoor heat exchanger, 4 Expansion mechanism, 5 Indoor heat exchanger, 6 Outdoor blower, 7 Indoor blower, 8 Outdoor temperature sensor, 9 Evaporation temperature sensor, 10 Control means.

Claims

Variable rotational speed of the inverter compressor, four-way valve, an indoor heat exchanger, an expansion mechanism, an outdoor heat exchanger is constituted by connecting sequentially pipe, the inverter compressor during the heating operation of the air conditioner Ru warm room A refrigeration cycle in which warm refrigerant discharged from the refrigerant flows sequentially from the indoor heat exchanger to the expansion mechanism and the outdoor heat exchanger by the four-way valve ;
An indoor fan with a variable number of rotations of the indoor heat exchanger;
An outdoor fan with a variable rotation speed of the outdoor heat exchanger;
An outside air temperature sensor for detecting the outside air temperature ta;
An evaporation temperature sensor that detects the temperature te of the outdoor heat exchanger that functions as an evaporator during the heating operation;
While receiving the outdoor temperature ta detected by the outdoor temperature sensor and the temperature te of the outdoor heat exchanger detected by the evaporation temperature sensor, the rotation speed of the inverter compressor, the rotation speed of the indoor blower, and the rotation of the outdoor blower Control means in which a defrosting start temperature difference Δtd corresponding to the number is preset,
Rotating said control means, said outside air temperature ta and to calculate the temperature difference Δt which is a difference ta-te temperature te of the outdoor heat exchanger, a temperature difference Δt which is the calculated, the inverter compressors at that time comparing, said a defrost start temperature difference Δtd corresponding to the rotational speed of the number and the rotational speed of the chamber feed air blower said outdoor blower, Delta] t> if Δtd made state is continued for a predetermined time, the four-way valve the switching, air conditioner, characterized in that shifting the warm refrigerant discharged from the inverter compressor from the warm Boun rolling to flow into the indoor heat exchanger defrosting operation flows into the outdoor heat exchanger.

Variable rotational speed of the inverter compressor, four-way valve, an indoor heat exchanger, an expansion mechanism, an outdoor heat exchanger is constituted by connecting sequentially pipe, the inverter compressor during the heating operation of the air conditioner Ru warm room A refrigeration cycle in which warm refrigerant discharged from the refrigerant flows sequentially from the indoor heat exchanger to the expansion mechanism and the outdoor heat exchanger by the four-way valve ;
An indoor fan with a variable number of rotations of the indoor heat exchanger;
An outdoor fan with a variable rotation speed of the outdoor heat exchanger;
An outside air temperature sensor for detecting the outside air temperature ta;
An evaporation temperature sensor that detects the temperature te of the outdoor heat exchanger that functions as an evaporator during the heating operation;
While receiving the outdoor temperature ta detected by the outdoor temperature sensor and the temperature te of the outdoor heat exchanger detected by the evaporation temperature sensor, the rotation speed of the inverter compressor, the rotation speed of the indoor blower, and the rotation of the outdoor blower Control means in which a defrosting start temperature difference Δtd corresponding to the number is preset,
Rotating said control means, said outside air temperature ta and to calculate the temperature difference Δt which is a difference ta-te temperature te of the outdoor heat exchanger, a temperature difference Δt which is the calculated, the inverter compressors at that time comparing said the defrost start temperature difference? td the number and the rotation speed of the chamber blower corresponding to the rotational speed of the chamber outside air blower, a, a Delta] t>? td, and the temperature te of the outdoor heat exchanger in advance It is lower than the set frost formation temperature, by switching the four-way valve, flowing warm refrigerant discharged from the inverter compressor to the outdoor heat exchanger from the warm Boun rolling to flow into the indoor heat exchanger An air conditioner that is shifted to a defrosting operation .

Claim wherein the control means, wherein the temperature difference Δt is before when Kijo higher frost start temperature difference Δtd state is continued for a predetermined time, characterized in that shifting to the defrosting operation from the warm Boun rolling 2. The air conditioner according to 2 .

Variable rotational speed of the inverter compressor, four-way valve, an indoor heat exchanger, an expansion mechanism, an outdoor heat exchanger is constituted by connecting sequentially pipe, the inverter compressor during the heating operation of the air conditioner Ru warm room A refrigeration cycle in which warm refrigerant discharged from the refrigerant flows sequentially from the indoor heat exchanger to the expansion mechanism and the outdoor heat exchanger by the four-way valve ;
An indoor fan with a variable number of rotations of the indoor heat exchanger;
An outdoor fan with a variable rotation speed of the outdoor heat exchanger;
An outside air temperature sensor for detecting the outside air temperature ta;
An evaporation temperature sensor that detects the temperature te of the outdoor heat exchanger that functions as an evaporator during the heating operation;
Control means for receiving the outdoor air temperature ta detected by the outdoor air temperature sensor and the temperature te of the outdoor heat exchanger detected by the evaporation temperature sensor;
The control means calculates a change rate of a temperature difference Δt, which is a difference ta-te between the outdoor air temperature ta and the temperature te of the outdoor heat exchanger, and the calculated change rate of the temperature difference Δt is the outdoor heat exchanger. The inverter compressor is switched by switching the four-way valve when the rate of change exceeds a preset change rate corresponding to the rotation speed of the variable speed device of the air conditioner, which is a factor for changing the temperature te of the air compressor. The air conditioner is characterized in that the air conditioner is shifted from the heating operation in which the warm refrigerant discharged from the air flows to the indoor heat exchanger to the defrosting operation in which the warm refrigerant is flowed to the outdoor heat exchanger .

It said control means, when the temperature te of the outdoor heat exchanger is higher than the preset defrost completion temperature tf from claim 1, characterized in Rukoto to terminate the defrosting operation according to claim 4 An air conditioner according to any one of the above.