JP2005048983A

JP2005048983A - Air conditioner

Info

Publication number: JP2005048983A
Application number: JP2003203582A
Authority: JP
Inventors: Nobuyuki Kiuchi; 信行木内; Seiichi Nakahara; 誠一中原; Hiroshi Ito; 浩伊藤
Original assignee: Saginomiya Seisakusho Inc
Current assignee: Saginomiya Seisakusho Inc
Priority date: 2003-07-30
Filing date: 2003-07-30
Publication date: 2005-02-24

Abstract

<P>PROBLEM TO BE SOLVED: To reduce unnecessary defrosting operation time, to reduce residual frost and carry out favorable defrosting operation, and to improve comfortableness and reliability during heating operation in an air conditioner. <P>SOLUTION: An indoor heat exchanger temperature Tc is detected from a temperature sensor 303, and an indoor temperature Ta is detected from a temperature sensor 302. A temperature difference is calculated between the indoor heat exchanger temperature Tc and the indoor temperature Ta. After starting the heating operation, frost formation determination of an outdoor heat exchanger is carried out on the basis of the temperature difference. A difference between a temperature difference set value corresponding to an outside air temperature not causing frost formation, and an upper limit of a maximum temperature difference is provided as a threshold. During the heating operation, when the calculated temperature difference is less than the temperature difference set value, and it is less than the upper limit of the maximum temperature difference, a defrosting operation mask time is integrated, and when the calculated temperature difference is more than the upper limit of the maximum temperature difference, and it is more than the temperature difference set value, the defrosting operation mask time is not integrated. The frost formation determination is carried out after finishing integration of the defrosting operation mask time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、ヒートポンプ式の冷凍サイクルと制御装置とを備える空気調和機に関わり、室外熱交換器の着霜判定を行う空気調和機に関する。
【０００２】
【従来の技術】
従来、この種の空気調和機として、例えば、特開昭５５−８５１８号公報（特許文献１）、特開昭５５−１５０４４７号公報（特許文献２）、特開昭６０−３８５４４号公報（特許文献３）、特開平７−２３４０４２号公報（特許文献４）、特開平８−２６１５４１号公報（特許文献５）、特開２０００−７４４５３号公報（特許文献６）に開示されたものがある。
【０００３】
これらの従来の技術は空気調和機の除霜制御に関する先行技術であり、室内ユニットに具備される２本の温度センサを用いて、暖房運転時に室外ユニットの室外熱交換器に付着する霜の度合い（着霜）を判定し、除霜運転を開始する技術である。図１３は従来の暖房運転のフローチャートであり、ステップＳ１１で暖房運転の実行が可能となるのを監視し、可能となればステップＳ１２，Ｓ１３で除霜マスクタイマの計時が終了するまで暖房運転を実行する。除霜マスクタイマの計時が終了すると、ステップＳ１４で着霜判定を行う。そして、着霜していなければステップＳ１２、Ｓ１３、Ｓ１４を繰り返し、着霜していればステップＳ１５，Ｓ１６で除霜終了を監視しながら除霜運転を実行し、除霜終了が検出されるとステップＳ１７で除霜運転を終了する。
【０００４】
このような従来の処理では、着霜の判定を以下のように行う。例えば、図１４に示したように、暖房運転初期の温度差ΔＴ（＝Ｔｃ−Ｔａ）を最大温度差ΔＴｍａｘとして記憶し、その最大温度差ΔＴｍａｘに対する温度差ΔＴの割合βｎが所定の割合βｓｐよりも小さくなった場合に、着霜とみなす。なお、３本の温度センサを用い、破線で示した室外熱交換器温度Ｔｃ′をも検出すると除霜終了を容易に検出できるが、センサの本数が多くなってしまう。
【０００５】
【特許文献１】
特開昭５５−８５１８号公報
【特許文献２】
特開昭５５−１５０４４７号公報
【特許文献３】
特開昭６０−３８５４４号公報
【特許文献４】
特開平７−２３４０４２号公報
【特許文献５】
特開平８−２６１５４１号公報
【特許文献６】
特開２０００−７４４５３号公報
【０００６】
【発明が解決しようとする課題】
前記従来の技術では、天候の悪化や日没などにより外気温度が低下した場合に実際は着霜していないのに、あたかも着霜したように誤って判定して（カラ打ち）除霜運転を行うことがあり暖房運転時に快適性を損なうという点に、改良の余地が残されている。
【０００７】
例えば、図１５に示すように、上記従来の技術では、晴天の日中（例えば外気温２０℃の場合）に暖房運転を開始し、最大温度差ΔＴｍａｘを記憶した後、天候の悪化や日没などの影響で外気温が低下した場合（例えば２０℃→７℃）に、着霜の起こり得ない晴天時に記憶したΔＴｍａｘを基準にして、それに対する温度差ΔＴの割合βｎを求めて着霜判定を行うので、外気温の低下により暖房能力が低下し、着霜が無いにも関わらず温度差ΔＴの割合βｎが所定の割合βｓｐより小さくなった場合に、カラ打ち除霜を行ってしまうことがあり、改良の余地が残っている。
【０００８】
なお、前記従来技術の公報には、除霜運転を終了することについては、簡単に開示されているにすぎない。
【０００９】
一方、適正な判定で除霜運転を行っても、低温・高湿度の過酷条件、あるいは冷媒不足により除霜能力が低下している場合等に、設定した除霜運転時間では足りず、霜が残ることがあった。また、そのような状態が繰り返されると霜から凍結状態へと変化し、悪循環を招いて著しく信頼性を低下させる場合も考えられ、改良の余地が残されている。
【００１０】
本発明は、空気調和機において、着霜の誤判定による（カラ打ち）除霜運転時間を減少させ、あるいは残霜を低減して良好な除霜運転を行い、暖房運転時の快適性及び信頼性を向上させることを課題とする。
【００１１】
【課題を解決するための手段】
本発明の請求項１の空気調和機は、制御装置の処理部が室内熱交換器温度と室内温度との温度差を算出する制御工程と、暖房運転を開始した後、前記算出した温度差から室外熱交換器の着霜判定を行う制御工程とを備える空気調和機において、前記制御装置の記憶部に記憶した着霜が発生しない外気温度に対応する温度差設定値と、前記記憶部に記憶した最大温度差の上限値との差を閾値として設け、暖房運転中に、前記算出した温度差が前記温度差設定値を下回り、さらに前記最大温度差の上限値を下回る場合に除霜運転マスク時間を積算し、前記算出した温度差が前記最大温度差の上限値を上回り、さらに前記温度差設定値を上回る場合に除霜運転マスク時間を積算しない、ように処理することを特徴とする。
【００１２】
請求項１の空気調和機において、暖房運転を開始した後、除霜運転マスク時間の積算が完了したことを条件に、着霜判定を行う。その際、風などによる外気温度の頻繁な微下降／微上昇の影響を受けずに、閾値によってマクロ的な下降／上昇を認識して「積算する／積算しない」の判定を行うので、着霜の可能性がない場合には積算せず、着霜判定の機会が少なくなり、よってカラ打ち除霜が激減する。
【００１３】
本発明の請求項２の空気調和機は、制御装置の処理部が室内熱交換器温度と室内温度との温度差を算出する制御工程と、暖房運転を開始した後、前記算出した温度差から室外熱交換器の着霜判定を行う制御工程とを備える空気調和機において、前記着霜判定により着霜有りと判定して除霜運転を開始した後、所定時間（実施例では例えば２分）経過後に前記室内熱交換器温度が所定温度（実施例では例えば−７℃）を下回っていない時は、除霜運転を終了して暖房運転に復帰することを特徴とする。
【００１４】
除霜運転時にカラ打ち除霜を行っていると、室内熱交換器温度は所定温度以下にならない。したがって、請求項２の空気調和機によれば、除霜運転を開始した後、所定時間経過後に室内熱交換器温度が所定温度を下回っていない時は、除霜運転を終了して暖房運転に復帰するので、快適性を向上できる。
【００１５】
本発明の請求項３の空気調和機は、制御装置の処理部が室内熱交換器温度と室内温度との温度差を算出する制御工程と、暖房運転を開始した後、前記算出した温度差から室外熱交換器の着霜判定を行う制御工程とを備える空気調和機において、前記着霜判定により着霜有りと判定して除霜運転を開始した後、所定時間（実施例では例えば２分）経過時点から前記室内熱交換器温度の監視を続け、前記室内熱交換器温度が所定温度（実施例では例えば−７℃）を上回った時に、除霜運転を終了して暖房運転に復帰することを特徴とする。
【００１６】
請求項３の空気調和機によれば、着霜が少ない場合の除霜運転時には、あたかもカラ打ち除霜の状態に移行した時点で除霜運転を終了して暖房運転に復帰するので、快適性を向上できる。
【００１７】
本発明の請求項４の空気調和機は、制御装置の処理部が室内熱交換器温度と室内温度との温度差を算出する制御工程と、暖房運転を開始した後、前記算出した温度差から室外熱交換器の着霜判定を行う制御工程とを備える空気調和機において、前記着霜判定により着霜有りと判定して除霜運転を開始した後、所定時間（実施例では例えば６０秒）経過後に前記室内熱交換器温度の温度の下がり方が急峻から緩慢に変化した場合は、除霜運転を終了して暖房運転に復帰することを特徴とする。
【００１８】
着霜がない状態で除霜運転を行うと、室内熱交換器温度は急峻に下がって、所定時間経過後に下がり方が急峻から緩慢に変化する。したがって、請求項４の空気調和機によれば、除霜運転時にカラ打ち除霜の状態と判定し、除霜運転を終了して暖房運転に復帰するので、快適性を向上できる。
【００１９】
本発明の請求項５の空気調和機は、制御装置の処理部が室内熱交換器温度と室内温度との温度差を算出する制御工程と、暖房運転を開始した後、前記算出した温度差から室外熱交換器の着霜判定を行う制御工程とを備える空気調和機において、通常の除霜運転時間よりも短い時間の初期除霜運転時間を設け、前記着霜判定により着霜有りと判定して１回目の除霜運転を開始した後、前記初期除霜運転時間経過後に除霜運転を終了して暖房運転に復帰することを特徴とする。
【００２０】
請求項５の空気調和機によれば、１回目の除霜運転時間が通常の半分になるので、仮にカラ打ち除霜の状態であっても、その時間を短くすることができ、直ぐに暖房運転に復帰するので、快適性を向上できる。
【００２１】
本発明の請求項６の空気調和機は、請求項５の構成を備え、前記処理部が夕方から夜間の時間を認識して、前記初期除霜運転時間を設けることを特徴とする。
【００２２】
夕方から夜間の時間帯は、外気温度の急低下が発生しやすいので着霜の誤判定を起こしやすく、カラ打ち除霜の可能性がある。これに対して、請求項６の空気調和機によれば、請求項５と同様な作用効果が得られるとともに、上記カラ打ち除霜の状態となっても、これを短時間にすることができる。
【００２３】
本発明の請求項７の空気調和機は、請求項１、２、３、４、５、または６の構成を備え、除霜運転マスク時間の積算を完了した後の着霜判定により着霜有りと判定して１回目の除霜運転を行い、次に除霜運転を終了して、２回目の暖房運転を開始した後、前記除霜運転マスク時間が１／２経過したら室外熱交換器の着霜判定を行うことを特徴とする。
【００２４】
請求項７の空気調和機によれば、請求項１、２、３、４、５、または６と同様な作用効果が得られるとともに、１回目の除霜運転が不十分であった場合でも、除霜運転マスク時間の１／２の時間で、次回サイクルの着霜判定を行うので、好適な除霜運転、快適な暖房運転ができる。
【００２５】
本発明の請求項８の空気調和機は、制御装置の処理部が室内熱交換器温度と室内温度との温度差を算出する制御工程と、暖房運転を開始した後、前記算出した温度差から室外熱交換器の着霜判定を行う制御工程とを備える空気調和機において、暖房運転中に除霜マスク時間終了時点で着霜判定を行い、前記着霜判定により着霜有りと判定して除霜運転を開始し、次に除霜運転を終了して暖房運転に復帰する暖房サイクルを繰り返す場合、２回目以降の暖房サイクルの除霜マスク時間終了時点での温度差の割合により算出される除霜運転時間に、１暖房サイクル毎に所定短時間を加算して除霜運転時間を算出することを特徴とする。なお、所定時間は１分程度がよい。
【００２６】
請求項８の空気調和機によれば、低温・高湿度の過酷条件、あるいは冷媒不足により除霜能力が低下している場合等の、除霜運転を繰り返すような場合にも、設定した除霜運転時間が充分となり、残霜を低減することができ、信頼性を確保できる。
【００２７】
本発明の請求項９の空気調和機は、空気調和機の室内ユニットに２本の温度センサを備え、暖房運転を開始した後、前記２本の温度センサが検出する温度から算出する温度差に基づいて、前記空気調和機の室外ユニットへの着霜判定を行う空気調和機において、前記着霜判定により着霜有りと判定して除霜運転を開始した後、所定時間経過後に、前記着霜判定と異なる処理で着霜判定を行い、着霜していない場合は、除霜運転を終了して暖房運転に復帰することを特徴とする。
【００２８】
請求項９の空気調和機によれば、除霜運転時にも着霜判定を行っているので、カラ打ち除霜を極力抑え、快適な暖房運転ができる。
【００２９】
なお、次のような空気調和機も構成できる。
制御装置の処理部が室内熱交換器温度と室内温度との温度差を算出する制御工程と、暖房運転を開始した後、前記算出した温度差から室外熱交換器の着霜判定を行う制御工程とを備える空気調和機において、
前記制御装置の記憶部に最大温度差の上限値（所定の温度差設定値）を記憶し、暖房運転中に、前記算出した温度差が前記最大温度差の上限値（所定の温度差設定値）を下回る場合に除霜運転マスク時間を積算し、
前記算出した温度差が前記最大温度差の上限値（所定の温度差）を上回る場合に除霜運転マスク時間を積算しない、ように処理することを特徴とする空気調和機。
これにより、請求項１と同様であるが、特に低温、高湿度の条件発生が多い地域において、好適な着霜判定を行い、快適な暖房運転ができる。要するに、湿度が高いから風の影響とか無視して、最大温度差の上限値（所定の温度差設定値）のみで積算する／積算しないを判定しても差し支えない。
【００３０】
【発明の実施の形態】
次に、本発明による空気調和機の実施形態を図面を参照して説明する。図１は実施形態の空気調和機における冷凍サイクルとその制御装置の例を示す電気ブロック図、図２は同空気調和機の原理的ブロック図であり、図２の各要素は図１の各要素やその組合せに対応している。図２に示したように、圧縮機４、流路切換弁（四方弁）１００、室内熱交換器９Ａ、絞り装置１０Ａ、室外熱交換器９Ｂ、アキュムレータ２００により冷凍サイクルＡが構成されている。
【００３１】
図１において、室内制御部３００と室外制御部４００とは、共通電源線２２０、圧縮機制御線２２１、室外熱交換器制御線６２０の３本の電線（渡り線）で接続され、室内ユニット側の端子台に３つの端子と、室外ユニット側の端子台に３つの端子を各々備えている。圧縮機４は、運転周波数が一定の交流電動機（すなわち一定速圧縮機）である圧縮機動力源（電動機）４５０を動力源として駆動される。電源は単相交流であり、電源スイッチ３１０を介してＡＣ／ＤＣコンバータ３２０に供給され、各種内部電圧に変換された直流電力が各部に供給される。
マイコン３３０は、ドライバ、リレーからなる室外熱交換器駆動部Ｃ８、圧縮機駆動部Ｃ９を制御する。そして、圧縮機４の制御により流路切換弁（コイルレス四方弁）１００内の冷媒の圧力を制御し、流路切換弁１００の切換制御を行う。また、ファンモータ（室外熱交換器駆動源）４０１、および電動機（圧縮機動力源）４５０に電力が供給される。さらに、マイコン３３０は、ドライバ（室内熱交換器駆動部）Ｃ７を駆動し、室内熱交換器９Ａのファンモータ（室内熱交換器駆動源）３０１を制御する。
【００３２】
室内制御部３００は、温度センサ３０２によって室内温度Ｔａを検出し、その温度信号（温度データ）をコネクタ３０２ｃを介して取り込む。また、温度センサ３０３によって室内熱交換器９Ａの配管温度（室内熱交換器温度）Ｔｃを検出し、その温度信号（温度データ）をコネクタ３０３ｃを介して取り込む。そして、この温度Ｔａ，Ｔｃにより除霜制御を行う。なお、室内制御部３００は室外熱交換器９Ｂの配管温度（室外熱交換器温度）Ｔｃ′を検出する温度センサを接続可能にしたコネクタ４０３ｃを備えているが、無くてもよい。また、室内制御部３００は、赤外線式等のリモコン５００の送信部５００ａから送出される赤外線信号を受信部３０４で受信することにより、室内制御部３００の運転の切換えや設定等がリモコン操作でも可能となっている。
【００３３】
この実施形態では、２本の温度センサ３０２，３０３によって除霜制御を行うとともに、コイルレス四方弁である流路切換弁１００を非電気的な力（冷媒の圧力）により切り換えるものであり、室内制御部３００と室外制御部４００とは３本の電線で接続され、接続電線の数を削減したものとなっている。なお、前述のコイルレス四方弁とは特開２０００−２４９４３０号公報に開示されている四方弁である。また、流路切換弁１００として四方弁コイル１０１に通電することで流路を切り換えるような四方弁を用いる場合には、図１及び図２に破線で示したような接続ラインを設け、ドライバ、リレーからなる流路切換弁駆動部４０６をマイコン３３０で制御して、四方弁コイル（流路切換弁駆動源）１０１を駆動する。この場合は、流路切換弁制御線７１０を含めて４本の電線で接続される。
【００３４】
なお、図２の制御装置Ｃにおいて、入力部Ｃ２は、図１に示すリモコン５００の送信部５００ａから送出される赤外線信号を受信する室内ユニットに設けられた受信部３０４あるいは図示しないマニュアルスイッチに対応している。また、検出部Ｃ３は、室内温度Ｔａを検出する温度センサ３０２、室内熱交換器９Ａの配管温度（室内熱交換器温度）Ｔｃを検出する温度センサ３０３などに対応している。さらに、停電検出部Ｃ４は図示しない電圧検出器に対応し、半固定記憶部Ｃ５はＥＥＰＲＯＭ３４０に対応している。
【００３５】
ここで、実施形態において、室内温度Ｔａ及び室内熱交換器温度Ｔｃを検出するときに、温度センサ４０３が接続可能なコネクタ４０３ｃの出力信号も同時に得るようにしている。したがって、実施形態のように温度センサ４０３が接続されていなければ、コネクタ４０３ｃの抵抗値は無限大となり、例えばＴｃ′＜−４０℃のような判定条件を設け、２つの温度センサ３０２、及び３０３の出力信号によって好適に着霜判定を行えるように構成されている。
【００３６】
図１２は、室内熱交換器温度Ｔｃ、室内温度Ｔａ、及び温度差の状態変化の一例を示す図である。暖房運転開始後、単位時間毎に温度データを読み込み、後述の各実施例の条件に応じて除霜運転を行う。室内熱交換器温度Ｔｃと室内温度Ｔａとの温度差、暖房運転時には正の値であるが、除霜運転が進むと、室内熱交換器温度Ｔｃと室内温度Ｔａの温度差が負の値になる。なお、同図では室外熱交換器温度Ｔｃ′の変化を破線で示した。
【００３７】
次に実施形態における室内制御部３００のマイコン３３０による制御動作の各実施例をフローチャートに基づいて説明する。なお、マイコン３３０は、内部クロックをカウントすることにより時間を計時する各種タイマを備えている。図３は請求項９に対応する第１実施例のフローチャートであり、ステップＳ２１〜Ｓ２５は図１３のステップＳ１１〜Ｓ１５と同様な処理であり詳細な説明は省略する。ステップＳ２５で除霜運転を開始すると、ステップＳ２６で所定時間経過したかを判定する。判定がｎｏならステップＳ２５に戻り、判定がｙｅｓならステップＳ２７に進む。ステップＳ２７では、ステップＳ２４と異なる処理で第２の着霜判定を行う。
【００３８】
この第２の着霜判定で、着霜していなければステップＳ３０で除霜運転を強制終了してステップＳ２１に戻る。また、着霜していれば、ステップＳ２８で除霜運転を実行し、ステップＳ２９で除霜終了の判定を行う。除霜終了でなければステップＳ２８に戻り、除霜終了であればステップＳ３０に進む。このように、ステップＳ２７で、除霜運転時にも着霜判定を行っているので、カラ打ち除霜を極力抑えることができる。
【００３９】
図４は請求項１に対応する第２実施例のフローチャートであり、図３のステップＳ２２，Ｓ２３の間に行う処理を示している。なお、この処理では除霜マスクタイマを積算計時している状態か／していない状態かを示す積算フラグを用いている。また、算出温度差は室内熱交換器温度Ｔｃ−室内温度Ｔａであり、着霜が発生しない外気温度に対応する温度差設定値は例えば２０℃、最大温度差の上限値は例えば１８℃である。ステップＳ２２で暖房運転を開始すると、ステップＳ３１で、算出温度差が温度差設定値未満であるかを判定する。判定がｎｏであればステップＳ３２で積算フラグをリセットし、ステップＳ３３で除霜マスクタイマを積算計時しないでステップＳ２３に進む。ステップＳ２３では除霜マスクタイマが計時終了したかを判定しているので、このステップＳ３３を経た後はステップＳ２３で「終了していない」と判定されステップＳ２２に進む。
【００４０】
ステップＳ３１で判定がｙｅｓ（算出温度差＜温度差設定値）であれば、ステップＳ３４で算出温度差が最大温度差の上限値未満であるかを判定する。判定がｎｏであればステップＳ３５で積算フラグの状態を判定し、フラグがセットされていなければステップＳ３３に進み、フラグがセットされていればステップＳ３７で除霜マスクタイマを積算計時してステップＳ２３に進む。ステップＳ３４で判定がｙｅｓ（算出温度差＜最大温度差の上限値）であれば、ステップＳ３６で積算フラグをセットしてステップＳ３７に進む。
【００４１】
ここで、算出温度差が図５のように変化したとすると、図の▲１▼及び▲５▼の状態ではステップＳ３１→Ｓ３２→Ｓ３３→Ｓ２３と進み、図の▲２▼の状態ではステップＳ３１→Ｓ３４→Ｓ３５→Ｓ３３→Ｓ２３と進み、何れの場合も、除霜マスクタイマの計時を終了しない状態となり、着霜判定は行われない。一方、図の▲３▼の状態ではステップＳ３１→Ｓ３４→Ｓ３６→Ｓ３７→Ｓ２３と進み、図の▲４▼の状態ではステップＳ３１→Ｓ３４→Ｓ３５→Ｓ３７→Ｓ２３と進み、何れの場合も、除霜マスクタイマの計時を行うので、ステップＳ２３で計時が終了していれば図３のステップＳ２４で着霜判定を行う。
【００４２】
このように、温度差設定値（この例では２０℃）と最大温度差（この例では１８℃）の上限値との差を閾値として設け、この閾値により除霜マスクタイマを積算するか／積算しないかの判定を行っているので、例えば図５の▲１▼から▲２▼に移行するような状態や▲５▼のような状態、すなわち着霜の可能性がない場合には積算せず、着霜判定自体を行わないので、カラ打ち除霜が激減する。もちろん、低温・高湿度の条件発生が多い地域においては、閾値＝０℃、すなわち、最大温度差の上限値←温度差設定値とすれば、最大温度差の上限値を下回る場合に除霜運転マスク時間を積算し、最大温度差の上限値を上回る場合に除霜運転マスク時間を積算しない、としても良いことはいうまでもない。
【００４３】
次に、請求項２及び請求項３の実施例を説明するが、請求項２の実施例は、除霜開始２分後に、−７℃を下回っていないときは「カラ打ち」と判定し、一方、請求項３の実施例は、除霜開始２分後、−７℃を下回ってから監視を続け、その後−７℃を上回ったら除霜を終了する技術である。
【００４４】
図６は請求項２及び請求項３に対応する第３実施例のフローチャートであり、図３のステップＳ２５〜Ｓ３０に代わる（差し替える）処理である。ステップＳ４１で除霜運転を開始すると、ステップＳ４２で所定時間（例えば２分）が経過したかを判定し、判定がｎｏであればステップＳ４１に戻り、判定がｙｅｓであればステップＳ４３で室内熱交換器温度Ｔｃが−７℃以下となっているかを判定する。判定がｎｏ（Ｔｃ＞−７℃）であればステップＳ４６で除霜運転を終了して図３のステップＳ２１に戻る。判定がｙｅｓ（Ｔｃ≦−７℃）であれば、ステップＳ４４で除霜運転を実行し、ステップＳ４５で除霜終了の判定を行う。除霜終了でなければステップＳ４４に戻り（実線の矢印）、除霜終了であればステップＳ４６に進む。このステップＳ４５→Ｓ４３→Ｓ４６の処理は請求項２に対応している。すなわち、ステップＳ４１で除霜運転を実行して、カラ打ち除霜を行っていると、所定時間（例えば２分）が経過しても室内熱交換器温度Ｔｃが所定温度（−７℃）以下にならない。したがって、すぐにステップＳ４６で除霜運転を強制終了する。これにより、カラ打ち除霜を抑えることができる。なお、着霜が適度であればステップＳ４２→Ｓ４３→Ｓ４４→Ｓ４５の処理を行う。ここでステップＳ４５は、図１３のステップＳ１６と同様に温度差の割合により算出され設定された除霜運転時間が経過したか／否かによる除霜終了の判定であることはいうまでもない。
【００４５】
図６に示した破線の矢印は請求項３に対応する処理であり、ステップＳ４５で除霜終了でなければステップＳ４３に戻り、室内熱交換器温度Ｔｃを判定する。
すなわち、最初の除霜運転から例えば２分経過する前に、室内熱交換器温度Ｔｃがすでに−７℃以下まで低下しているとき、ステップＳ４４で除霜運転を実行し、ステップＳ４５で除霜終了の判定を行う。除霜終了でなければステップＳ４３に戻り（破線の矢印）、除霜終了であればステップＳ４６に進み、除霜運転を終了する。すなわち、カラ打ち除霜ではないが着霜が少ない（カラ打ち気味の）場合は、ステップＳ４２→Ｓ４３（ｙｅｓ）→Ｓ４４→Ｓ４５（ｎｏ：破線）→Ｓ４３（ｙｅｓ）→…（繰り返し）…→Ｓ４３（ｎｏ）→Ｓ４６の処理を行う。このように、着霜が少なくカラ打ち気味除霜の状態に移行した時点で除霜運転を終了するので、快適な暖房運転ができる。
【００４６】
図７は請求項４に対応する第４実施例のフローチャートであり、図３のステップＳ２５〜Ｓ３０に代わる（差し替える）処理である。ステップＳ５１で除霜運転を開始すると、ステップＳ５３で所定時間（例えば６０秒）が経過するまでステップＳ５１，ステップＳ５２を繰り返す。ステップＳ５２では１０秒毎の室内熱交換器温度Ｔｃの下がり方を算出してメモリに記憶する。この処理は除霜運転開始から１０秒毎の室内熱交換器温度Ｔｃを測定しながら、その測定値ｔ_１０，ｔ_２０，…，ｔ_６０から、例えば除霜運転開始から２０秒後の下がり方としてδｔ２を算出し、６０秒後の下がり方としてδｔ６を、次式から算出する。
δｔ２＝（ｔ_２０−ｔ_１０）／１０
δｔ６＝（ｔ_６０−ｔ_５０）／１０
【００４７】
そして、ステップＳ５３で所定時間が経過したら、ステップＳ５４で「δｔ２≧δｔ６」であるかを判定する。この判定がｙｅｓであれば温度の下がり方が緩慢から急峻になった場合であり、判定がｎｏであれば温度の下がり方が急峻から緩慢になった場合である。なお、除霜運転を開始すると室内熱交換器温度Ｔｃは下がるのでδｔ２，δｔ６は負の値（負の傾き）となる。前者（ｙｅｓ）であればステップＳ５５で除霜運転を実行し、ステップＳ５６で除霜終了の判定を行う。除霜終了でなければステップＳ５５に戻り、除霜終了であればステップＳ５７で除霜運転を終了する。後者（ｎｏ）の場合はステップＳ５７で除霜運転を終了して図３のステップＳ２１に戻る。
【００４８】
以上の処理は例えば図８のような温度変化に対応する処理である。すなわち、室外熱交換器に着霜があれば、室内熱交換器温度Ｔｃの下がり方が緩慢から急峻になるので、この場合は除霜運転を続行する。一方、着霜がなければ、室内熱交換器温度Ｔｃの下がり方が急峻から緩慢になるので、この場合は、除霜運転を強制終了する。これにより、カラ打ち除霜を抑えることができる。
【００４９】
図９は請求項５及び請求項６に対応する第５実施例のフローチャートであり、図３のステップＳ２５〜Ｓ３０に代わる（差し替える）処理である。ステップＳ６１で除霜運転を開始すると、ステップＳ６２で時刻は夕方から夜間の間であるかを判定し、判定がｎｏであればステップＳ６３で通常の除霜運転時間をセットしてステップＳ６６に進む。判定がｙｅｓであればステップＳ６４で１回目の除霜運転であるかを判定し、１回目でなければステップＳ６３に進み、１回目であればステップＳ６５で通常の除霜運転時間の１／２を除霜運転時間（初期除霜運転時間）としてセットし、ステップＳ６６に進む。ステップＳ６６では、セットした除霜運転時間が経過したかを判定し、経過していなければステップＳ６１に戻り、経過していればステップＳ６７で除霜運転を終了して図３のステップＳ２１に戻る。
【００５０】
このように、１回目の除霜運転時間が通常の除霜運転時間の半分になるので、仮にカラ打ち除霜の状態となっていても、その時間を短くすることができ、直ぐに暖房運転にすることもできる。また、夕方から夜間の時間帯は、外気温度の急低下が発生しやすいので着霜の誤判定を起こしやすいが、この誤判定によりカラ打ち除霜の状態となっても、その時間を短時間にすることができる。
【００５１】
図１０は請求項７に対応する第６実施例のフローチャートであり、図３のステップＳ２２〜２４に代わる（差し替える）処理である。ステップＳ７１で暖房運転を開始すると、ステップＳ７２で、暖房運転は２回目かを判定し、判定がｎｏであればそのままステップＳ７４に進み、２回目であればステップＳ７３で除霜除霜マスクタイマを１／２の時間にセットしてステップＳ７４に進む。そして、ステップＳ７４で、除霜マスクタイマが計時終了したかを判定し、終了していなければステップＳ７１に戻り、終了していればステップＳ７５で着霜判定を行う。着霜していなければステップＳ７１に戻り、着霜していれば図３のステップＳ２５に進む。このように、１回目の除霜運転が不十分であった場合でも、除霜運転マスク時間（除霜マスクタイマ）の１／２の時間で、次の着霜判定を行うので、好適に除霜ができる。
【００５２】
図１１は請求項８に対応する第７実施例のフローチャートである。まず、ステップＳ８１で暖房運転の実行が可能となるのを監視し、可能となればステップＳ８２，Ｓ８３で除霜マスクタイマの計時が終了するまで暖房運転を実行する。除霜マスクタイマの計時が終了すると、ステップＳ８４で、計時終了後の最初のパス（当該フローのパス）であるかを判定し、最初のパスであればステップＳ８５に進み、２回目以降のパスであればステップＳ８９に進む。なお、ステップＳ８４の処理は判定フラグを用いる処理もあるが、ここでは実施例のフローチャートとした。ここで具体例を記述する。例えば、タイマは０．１秒毎に計時し、除霜マスクタイマが５０分の設定とする。ステップＳ８３（０．１秒毎に判定処理する）の処理において、５０分未満の計時の場合は、ｎｏでありステップＳ８２に戻る。次に、丁度５０分を計時した場合は、ｙｅｓとなりステップＳ８４に進み、この場合は計時終了後の最初のパスであるから、ｙｅｓとなりステップＳ８５に進む。なお、Ｓ８３（ｙｅｓ）→Ｓ８４（ｙｅｓ）は必ず１回しか通り得ない。次のＳ８５（ｙｅｓ）で連続除霜、Ｓ８５（ｎｏ）で非連続除霜の場合分けが選択される。次に、ステップＳ８５の判定がｙｅｓであれば、請求項８に対応する処理、すなわち「連続除霜」としてステップＳ８５→Ｓ８６→Ｓ８７→Ｓ８８→Ｓ９２の処理を行う。一方、ステップＳ８５の判定がｎｏであれば、ステップＳ８２に戻り、次に、ステップＳ８３では５０分から０．１秒経過しているので、ｙｅｓとなりステップＳ８４に進む。しかし、ステップＳ８４において、５０分０．１秒で２回目のパスであるから、ｎｏとなりステップＳ８９に進む。ステップＳ８９移行の処理は「非連続除霜」であり、ステップＳ９０、ステップＳ９１も含めて、既に前述した実施例の処理と同様である。
【００５３】
ここで、この第７実施例の処理は、暖房運転初期の温度差ΔＴ（＝Ｔｃ−Ｔａ）を最大温度差ΔＴｍａｘとして記憶し、その最大温度差ΔＴｍａｘに対する温度差ΔＴの割合βｎを求める。そして、この温度差の割合と予め設定された設定割合とを比較して、温度差の割合が設定割合以下である場合、温度差の割合の大／小に応じて除霜運転時間を短／長に設定する。さらに、着霜判定により着霜有りと判定して除霜運転の実行及び終了の処理を行い、次の着霜判定でも着霜有りと判定されるように、除霜運転を繰り返す場合（連続して着霜有りとなった場合）にその繰り返す回数を連続除霜回数として計数する。そして、この連続して繰り返される場合（以後、「連続除霜」という。）と、連続しないで繰り返される場合（以後、「非連続除霜」という。）とで、除霜運転時間を変化させるようにする。なお、連続除霜回数は初期設定で“０”にリセットされているものとする。いうまでもないが、例えば、除霜マスクタイマが５０分の場合、丁度５０分毎に着霜有りと判定して除霜運転を実施する場合が「連続除霜」であり、低温・高湿度の過酷条件等の場合に示現する。前述以外の場合は「非連続除霜」の処理を行う。
【００５４】
すなわち、「連続除霜」の場合には、初回はステップＳ８４→Ｓ８５→Ｓ８６→Ｓ８７→Ｓ９１のルートにより、割合βｎにより算出される除霜運転時間がそのまま設定されるが、２回目以降はステップＳ８４→Ｓ８５→Ｓ８６→Ｓ８７→Ｓ８８のルートにより、割合βｎにより算出される除霜運転時間に（連続除霜回数−１）分を加算してセットする。これにより、連続２回目は除霜運転時間が（βｎにより設定された除霜運転時間＋１）分となり、連続３回目は除霜運転時間が（βｎにより設定された除霜運転時間＋２）分となり、連続４回目は除霜運転時間が（βｎにより設定された除霜運転時間＋３）分となる。そして、ステップＳ９２，Ｓ９３，Ｓ９４により除霜運転の実行及び終了を行う。なお、「非連続除霜」の場合は、必ずステップＳ８４（ｙｅｓ）→Ｓ８５（ｎｏ）→Ｓ８２→Ｓ８３→Ｓ８４（ｎｏ）の処理を実行する。ステップＳ８９で着霜判定を行い、ｎｏならステップＳ８２に戻り、ｙｅｓならステップＳ９０では（非連続除霜であるから）連続除霜回数を０として、次にステップＳ９１で割合βｎにより算出される除霜運転時間を設定して、ステップＳ９２、Ｓ９３、Ｓ９４により除霜運転の実行及び終了を行う。
【００５５】
【発明の効果】
請求項１の空気調和機によれば、暖房運転を開始した後、除霜運転マスク時間の積算が完了したことを条件に着霜判定を行い、その際、風などによる外気温度の頻繁な微下降／微上昇の影響を受けずに、閾値によってマクロ的な下降／上昇を認識して「積算する／積算しない」の判定を行うので、着霜の可能性がない場合には積算せず、着霜判定の機会が少なくなり、よってカラ打ち除霜が激減する。したがって、暖房運転時の快適性を向上できる。
【００５６】
請求項２の空気調和機によれば、除霜運転を開始した後、所定時間経過後に室内熱交換器温度が所定温度を下回っていない時は、除霜運転を終了して暖房運転に復帰するので、快適性を向上できる。
【００５７】
請求項３の空気調和機によれば、着霜が少ない場合の除霜運転時には、あたかもカラ打ち除霜の状態に移行した時点で除霜運転を終了して暖房運転に復帰するので、快適性を向上できる。
【００５８】
請求項４の空気調和機によれば、除霜運転時にカラ打ち除霜の状態と判定し、除霜運転を終了して暖房運転に復帰するので、快適性を向上できる。
【００５９】
請求項５の空気調和機によれば、１回目の除霜運転時間が通常の半分になるので、仮にカラ打ち除霜の状態であっても、その時間を短くすることができ、直ぐに暖房運転に復帰するので、快適性を向上できる。
【００６０】
請求項６の空気調和機によれば、請求項５と同様な効果が得られるとともに、上記カラ打ち除霜の状態となっても、これを短時間にすることができる。
【００６１】
請求項７の空気調和機によれば、請求項１、２、３、４、５、または６と同様な効果が得られるとともに、１回目の除霜運転が不十分であった場合でも、除霜運転マスク時間の１／２の時間で、次回サイクルの着霜判定を行うので、好適な除霜運転、快適な暖房運転ができる。
【００６２】
請求項８の空気調和機によれば、低温・高湿度の過酷条件、あるいは冷媒不足により除霜能力が低下している場合等の、除霜運転を繰り返すような場合にも、設定した除霜運転時間が充分となり、残霜を低減することができ、信頼性を確保できる。
【００６３】
請求項９の空気調和機によれば、除霜運転時にも着霜判定を行っているので、カラ打ち除霜を極力抑え、快適な暖房運転ができる。
【図面の簡単な説明】
【図１】本発明の実施形態の空気調和機における冷凍サイクルとその制御装置の例を示す電気ブロック図である。
【図２】同空気調和機の原理的ブロック図である。
【図３】本発明の実施形態の第１実施例のフローチャートである。
【図４】本発明の実施形態の第２実施例のフローチャートである。
【図５】本発明の実施形態の第２実施例における算出温度差の変化の一例を示す図である。
【図６】本発明の実施形態の第３実施例のフローチャートである。
【図７】本発明の実施形態の第４実施例のフローチャートである。
【図８】本発明の実施形態の第４実施例における室内熱交換器温度の変化の一例を示す図である。
【図９】本発明の実施形態の第５実施例のフローチャートである。
【図１０】本発明の実施形態の第６実施例のフローチャートである。
【図１１】本発明の実施形態の第７実施例のフローチャートである。
【図１２】本発明の実施形態における熱交換器温度、室内温度及び温度差の状態変化の一例を示す図である。
【図１３】従来の暖房運転中における除霜運転のフローチャートである。
【図１４】何の外乱もなく正常に着霜を検出する場合の従来の一例を示す図である。
【図１５】日没などによりカラ打ち除霜を行う場合の従来の一例を示す図である。
【符号の説明】
３００室内制御部
３０２，３０３温度センサ
３３０マイコン[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air conditioner including a heat pump type refrigeration cycle and a control device, and relates to an air conditioner that performs frost determination of an outdoor heat exchanger.
[0002]
[Prior art]
Conventionally, as this type of air conditioner, for example, JP-A-55-8518 (Patent Document 1), JP-A-55-150447 (Patent Document 2), JP-A-60-38544 (Patent Document 1) Document 3), Japanese Patent Application Laid-Open No. 7-234042 (Patent Document 4), Japanese Patent Application Laid-Open No. 8-261541 (Patent Document 5), and Japanese Patent Application Laid-Open No. 2000-74453 (Patent Document 6).
[0003]
These conventional techniques are prior arts related to defrosting control of an air conditioner, and the degree of frost adhering to the outdoor heat exchanger of the outdoor unit during heating operation using two temperature sensors provided in the indoor unit. This is a technique for determining (frosting) and starting the defrosting operation. FIG. 13 is a flowchart of a conventional heating operation. In step S11, it is monitored that the heating operation can be performed. If it is possible, the heating operation is performed until the time of the defrost mask timer is finished in steps S12 and S13. Execute. When the time measurement of the defrost mask timer ends, frost formation determination is performed in step S14. If frost formation is not performed, steps S12, S13, and S14 are repeated. If frost formation is performed, the defrost operation is performed while monitoring the completion of defrosting in steps S15 and S16, and the completion of defrosting is detected. In step S17, the defrosting operation is terminated.
[0004]
In such a conventional process, the determination of frost formation is performed as follows. For example, as shown in FIG. 14, the temperature difference ΔT (= Tc−Ta) at the initial stage of the heating operation is stored as the maximum temperature difference ΔTmax, and the ratio βn of the temperature difference ΔT with respect to the maximum temperature difference ΔTmax is determined from the predetermined ratio βsp. Is also considered frost formation. Note that if the three heat sensors are used and the outdoor heat exchanger temperature Tc ′ indicated by the broken line is also detected, the end of the defrosting can be easily detected, but the number of sensors increases.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 55-8518
[Patent Document 2]
JP-A-55-150447
[Patent Document 3]
Japanese Patent Laid-Open No. 60-38544
[Patent Document 4]
Japanese Patent Laid-Open No. 7-234042
[Patent Document 5]
JP-A-8-261541
[Patent Document 6]
JP 2000-74453 A
[0006]
[Problems to be solved by the invention]
In the conventional technique, when the outside air temperature is lowered due to bad weather, sunset, or the like, frost is not actually formed, but it is erroneously determined as if it has been frosted (decoloring) and defrosting operation is performed. There is still room for improvement in that the comfort is impaired during heating operation.
[0007]
For example, as shown in FIG. 15, in the above-described conventional technique, heating operation is started on a clear day (for example, when the outside air temperature is 20 ° C.), and after storing the maximum temperature difference ΔTmax, the weather is deteriorated or sunset When the outside air temperature decreases due to the influence of the above or the like (for example, 20 ° C. → 7 ° C.), the frost determination is performed by obtaining the ratio βn of the temperature difference ΔT with respect to ΔTmax memorized at the time of fine weather where frost cannot occur. Therefore, the heating capacity is reduced due to a decrease in the outside air temperature, and when the ratio βn of the temperature difference ΔT becomes smaller than the predetermined ratio βsp in spite of the absence of frosting, the defrosting is performed. There is room for improvement.
[0008]
It should be noted that the prior art publication simply discloses that the defrosting operation is terminated.
[0009]
On the other hand, even if the defrosting operation is performed with an appropriate judgment, the set defrosting operation time is not enough when the defrosting performance is reduced due to severe conditions of low temperature and high humidity, or due to insufficient refrigerant, There was some remaining. Moreover, when such a state is repeated, it may change from frost to a frozen state, which may cause a vicious cycle and significantly reduce reliability, leaving room for improvement.
[0010]
In the air conditioner, the defrosting operation time due to erroneous frost formation (coloring) is reduced, or the remaining frost is reduced to perform a good defrosting operation, so that comfort and reliability during heating operation are achieved. The problem is to improve the performance.
[0011]
[Means for Solving the Problems]
In the air conditioner according to claim 1 of the present invention, the processing unit of the control device calculates the temperature difference between the indoor heat exchanger temperature and the room temperature, and after starting the heating operation, the temperature difference is calculated from the calculated temperature difference. An air conditioner including a control process for performing frost determination of an outdoor heat exchanger, and a temperature difference set value corresponding to an outside air temperature that is stored in the storage unit of the control device and does not generate frost, and stored in the storage unit The difference between the maximum temperature difference and the upper limit of the maximum temperature difference is set as a threshold, and the defrosting operation mask is set when the calculated temperature difference is lower than the temperature difference set value and lower than the upper limit of the maximum temperature difference during heating operation. Time is accumulated, and processing is performed so that the defrosting operation mask time is not accumulated when the calculated temperature difference exceeds the upper limit value of the maximum temperature difference and exceeds the temperature difference set value.
[0012]
In the air conditioner according to claim 1, the frost determination is performed on the condition that the integration of the defrosting operation mask time is completed after the heating operation is started. At that time, it is not influenced by frequent slight decrease / increase of the outside air temperature due to wind or the like, and the macro decrease / increase is recognized according to the threshold value, and “accumulation / non-accumulation” is determined. When there is no possibility, the accumulation is not performed, and the chance of frost formation determination is reduced.
[0013]
In the air conditioner according to claim 2 of the present invention, the processing unit of the control device calculates the temperature difference between the indoor heat exchanger temperature and the room temperature, and after starting the heating operation, the temperature difference is calculated from the calculated temperature difference. In an air conditioner provided with a control process for performing frost determination on an outdoor heat exchanger, a predetermined time (for example, 2 minutes in the embodiment) is determined after the frost determination determines that there is frost formation and starts the defrosting operation. When the indoor heat exchanger temperature does not fall below a predetermined temperature (for example, −7 ° C. in the embodiment) after the elapse of time, the defrosting operation is terminated and the heating operation is resumed.
[0014]
If empty defrosting is performed during the defrosting operation, the indoor heat exchanger temperature does not fall below a predetermined temperature. Therefore, according to the air conditioner of the second aspect, after the defrosting operation is started, when the indoor heat exchanger temperature is not lower than the predetermined temperature after the elapse of a predetermined time, the defrosting operation is ended and the heating operation is started. Because it returns, comfort can be improved.
[0015]
In the air conditioner according to claim 3 of the present invention, the processing unit of the control device calculates the temperature difference between the indoor heat exchanger temperature and the indoor temperature, and after starting the heating operation, the temperature difference is calculated from the calculated temperature difference. In an air conditioner provided with a control process for performing frost determination on an outdoor heat exchanger, a predetermined time (for example, 2 minutes in the embodiment) is determined after the frost determination determines that there is frost formation and starts the defrosting operation. The monitoring of the indoor heat exchanger temperature is continued from the elapsed time, and when the indoor heat exchanger temperature exceeds a predetermined temperature (for example, −7 ° C. in the embodiment), the defrosting operation is terminated and the heating operation is resumed. It is characterized by.
[0016]
According to the air conditioner of the third aspect, at the time of defrosting operation when there is little frost formation, the defrosting operation is ended and the operation is returned to the heating operation at the time when the state is shifted to the beating-up defrosting state. Can be improved.
[0017]
In the air conditioner according to claim 4 of the present invention, the processing unit of the control device calculates the temperature difference between the indoor heat exchanger temperature and the room temperature, and after starting the heating operation, the temperature difference is calculated from the calculated temperature difference. In an air conditioner including a control process for performing frost determination on the outdoor heat exchanger, a predetermined time (for example, 60 seconds in the embodiment) after starting the defrost operation by determining the presence of frost by the frost determination. If the method of decreasing the temperature of the indoor heat exchanger temperature changes from steep to slow after the elapse of time, the defrosting operation is terminated and the heating operation is resumed.
[0018]
When the defrosting operation is performed in a state where there is no frost formation, the indoor heat exchanger temperature decreases sharply, and after a predetermined time elapses, the decreasing direction changes from steep to slow. Therefore, according to the air conditioner of the fourth aspect, it is determined that the defrosting state is in the defrosting operation, the defrosting operation is terminated, and the heating operation is resumed. Therefore, the comfort can be improved.
[0019]
In the air conditioner according to claim 5 of the present invention, the processing unit of the control device calculates the temperature difference between the indoor heat exchanger temperature and the room temperature, and after starting the heating operation, the temperature difference is calculated from the calculated temperature difference. In an air conditioner including a control process for performing frost determination on an outdoor heat exchanger, an initial defrost operation time shorter than a normal defrost operation time is provided, and it is determined that frost is present by the frost determination. Then, after starting the first defrosting operation, after the initial defrosting operation time has elapsed, the defrosting operation is terminated and the heating operation is resumed.
[0020]
According to the air conditioner of claim 5, since the first defrosting operation time is half of the normal time, even if it is in the state of defrosting, the time can be shortened and the heating operation is immediately performed. Because it returns to, comfort can be improved.
[0021]
An air conditioner according to a sixth aspect of the present invention has the configuration of the fifth aspect, wherein the processing unit recognizes a time from evening to night and provides the initial defrosting operation time.
[0022]
From the evening to the night time, a sudden decrease in the outside air temperature is likely to occur, so that erroneous determination of frost formation is likely to occur, and there is a possibility of defrosting. On the other hand, according to the air conditioner of the sixth aspect, the same effect as that of the fifth aspect can be obtained, and this can be shortened in a short time even if the state of the decolorization is performed. .
[0023]
An air conditioner according to a seventh aspect of the present invention has the configuration according to the first, second, third, fourth, fifth, or sixth aspect, and frost is formed by frost determination after completing the integration of the defrosting operation mask time. And the first defrosting operation is performed, then the defrosting operation is terminated and the second heating operation is started. Then, when the defrosting operation mask time has elapsed 1/2, the outdoor heat exchanger It is characterized by performing frost formation determination.
[0024]
According to the air conditioner of the seventh aspect, the same effect as that of the first, second, third, fourth, fifth or sixth aspect can be obtained, and even when the first defrosting operation is insufficient, Since the frosting determination of the next cycle is performed in half the defrosting operation mask time, a suitable defrosting operation and a comfortable heating operation can be performed.
[0025]
The air conditioner according to claim 8 of the present invention is based on the control step in which the processing unit of the control device calculates the temperature difference between the indoor heat exchanger temperature and the indoor temperature, and after the heating operation is started, An air conditioner including a control step for performing frost determination on an outdoor heat exchanger, performing frost determination at the end of the defrost mask time during heating operation, and determining that frost has been formed by the frost determination and removing it. When repeating the heating cycle that starts the frost operation and then ends the defrost operation and returns to the heating operation, the removal calculated by the ratio of the temperature difference at the end of the defrost mask time of the second and subsequent heating cycles. A defrosting operation time is calculated by adding a predetermined short time every heating cycle to the frost operation time. The predetermined time is preferably about 1 minute.
[0026]
According to the air conditioner of claim 8, the set defrosting is also performed in the case where the defrosting operation is repeated, such as when the defrosting capability is reduced due to severe conditions of low temperature and high humidity or insufficient refrigerant. Operation time becomes sufficient, residual frost can be reduced, and reliability can be ensured.
[0027]
The air conditioner according to claim 9 of the present invention includes two temperature sensors in the indoor unit of the air conditioner, and after starting the heating operation, the temperature difference calculated from the temperatures detected by the two temperature sensors is calculated. On the basis of the air conditioner that performs frost determination on the outdoor unit of the air conditioner based on the frost determination, it is determined that frost is present and the defrosting operation is started. The frosting determination is performed by a process different from the determination, and when frosting is not performed, the defrosting operation is terminated and the heating operation is restored.
[0028]
According to the air conditioner of the ninth aspect, since the frost determination is performed even during the defrosting operation, it is possible to suppress the defrosting as much as possible and to perform a comfortable heating operation.
[0029]
The following air conditioner can also be configured.
A control process in which the processing unit of the control device calculates a temperature difference between the indoor heat exchanger temperature and the room temperature, and a control process in which after the heating operation is started, the frost determination of the outdoor heat exchanger is performed from the calculated temperature difference. In an air conditioner comprising:
An upper limit value (predetermined temperature difference setting value) of the maximum temperature difference is stored in the storage unit of the control device, and the calculated temperature difference becomes the upper limit value of the maximum temperature difference (predetermined temperature difference setting value) during heating operation. ), The defrosting operation mask time is added up,
An air conditioner characterized in that processing is performed such that the defrosting operation mask time is not integrated when the calculated temperature difference exceeds an upper limit value (predetermined temperature difference) of the maximum temperature difference.
Thereby, although it is the same as that of Claim 1, a suitable heating operation can be performed by performing suitable frost determination especially in an area where conditions of low temperature and high humidity are frequently generated. In short, since the humidity is high, it may be determined whether or not the integration is performed only with the upper limit value (predetermined temperature difference setting value) of the maximum temperature difference, ignoring the influence of the wind.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of an air conditioner according to the present invention will be described with reference to the drawings. FIG. 1 is an electric block diagram showing an example of a refrigeration cycle and its control device in the air conditioner of the embodiment, FIG. 2 is a principle block diagram of the air conditioner, and each element in FIG. 2 is each element in FIG. And their combinations. As shown in FIG. 2, the refrigeration cycle A is constituted by the compressor 4, the flow path switching valve (four-way valve) 100, the indoor heat exchanger 9A, the expansion device 10A, the outdoor heat exchanger 9B, and the accumulator 200.
[0031]
In FIG. 1, the indoor control unit 300 and the outdoor control unit 400 are connected by three electric wires (crossover wires) including a common power line 220, a compressor control line 221, and an outdoor heat exchanger control line 620. The terminal block is provided with three terminals, and the outdoor unit side terminal block is provided with three terminals. The compressor 4 is driven by using a compressor power source (electric motor) 450 that is an AC motor having a constant operating frequency (that is, a constant speed compressor) as a power source. The power source is a single-phase alternating current, and is supplied to the AC / DC converter 320 via the power switch 310, and direct-current power converted into various internal voltages is supplied to each part.
The microcomputer 330 controls an outdoor heat exchanger driving unit C8 and a compressor driving unit C9 that are composed of drivers and relays. And the pressure of the refrigerant | coolant in the flow-path switching valve (coilless four-way valve) 100 is controlled by control of the compressor 4, and the switching control of the flow-path switching valve 100 is performed. Electric power is supplied to a fan motor (outdoor heat exchanger drive source) 401 and an electric motor (compressor power source) 450. Further, the microcomputer 330 drives a driver (indoor heat exchanger drive unit) C7 and controls a fan motor (indoor heat exchanger drive source) 301 of the indoor heat exchanger 9A.
[0032]
The indoor control unit 300 detects the indoor temperature Ta by the temperature sensor 302, and takes in the temperature signal (temperature data) via the connector 302c. Further, the temperature sensor 303 detects the piping temperature (indoor heat exchanger temperature) Tc of the indoor heat exchanger 9A, and takes in the temperature signal (temperature data) via the connector 303c. And defrost control is performed by this temperature Ta and Tc. In addition, although the indoor control part 300 is provided with the connector 403c which enabled the connection of the temperature sensor which detects the piping temperature (outdoor heat exchanger temperature) Tc 'of the outdoor heat exchanger 9B, it does not need to be. In addition, the indoor control unit 300 receives the infrared signal transmitted from the transmission unit 500a of the infrared remote control 500 by the reception unit 304, so that the operation switching and setting of the indoor control unit 300 can be performed by remote control operation. It has become.
[0033]
In this embodiment, defrosting control is performed by two temperature sensors 302 and 303, and the flow path switching valve 100, which is a coilless four-way valve, is switched by a non-electric force (refrigerant pressure). The unit 300 and the outdoor control unit 400 are connected by three electric wires, and the number of connecting electric wires is reduced. The coilless four-way valve described above is a four-way valve disclosed in Japanese Patent Laid-Open No. 2000-249430. When a four-way valve that switches the flow path by energizing the four-way valve coil 101 as the flow path switching valve 100 is provided with a connection line as indicated by a broken line in FIG. 1 and FIG. The flow path switching valve drive unit 406 formed of a relay is controlled by the microcomputer 330 to drive the four-way valve coil (flow path switching valve drive source) 101. In this case, the four lines including the flow path switching valve control line 710 are connected.
[0034]
2, the input unit C2 corresponds to the receiving unit 304 provided in the indoor unit that receives the infrared signal transmitted from the transmitting unit 500a of the remote controller 500 shown in FIG. 1 or a manual switch (not shown). is doing. The detection unit C3 corresponds to a temperature sensor 302 that detects the indoor temperature Ta, a temperature sensor 303 that detects the piping temperature (indoor heat exchanger temperature) Tc of the indoor heat exchanger 9A, and the like. Further, the power failure detection unit C4 corresponds to a voltage detector (not shown), and the semi-fixed storage unit C5 corresponds to the EEPROM 340.
[0035]
Here, in the embodiment, when the indoor temperature Ta and the indoor heat exchanger temperature Tc are detected, an output signal of the connector 403c to which the temperature sensor 403 can be connected is obtained at the same time. Therefore, if the temperature sensor 403 is not connected as in the embodiment, the resistance value of the connector 403c is infinite, and for example, a determination condition such as Tc ′ <− 40 ° C. is provided, and the two temperature sensors 302 and 303 are provided. It is comprised so that frost formation determination can be performed suitably by this output signal.
[0036]
FIG. 12 is a diagram illustrating an example of a state change of the indoor heat exchanger temperature Tc, the indoor temperature Ta, and the temperature difference. After starting the heating operation, the temperature data is read every unit time, and the defrosting operation is performed according to the conditions of each example described later. The temperature difference between the indoor heat exchanger temperature Tc and the room temperature Ta is a positive value during heating operation, but when the defrosting operation proceeds, the temperature difference between the indoor heat exchanger temperature Tc and the room temperature Ta becomes a negative value. Become. In the figure, the change in the outdoor heat exchanger temperature Tc ′ is indicated by a broken line.
[0037]
Next, each example of the control operation by the microcomputer 330 of the indoor control unit 300 in the embodiment will be described based on a flowchart. The microcomputer 330 includes various timers that measure time by counting internal clocks. FIG. 3 is a flowchart of the first embodiment corresponding to claim 9. Steps S21 to S25 are the same processes as steps S11 to S15 of FIG. When the defrosting operation is started in step S25, it is determined whether a predetermined time has elapsed in step S26. If the determination is no, the process returns to step S25, and if the determination is yes, the process proceeds to step S27. In step S27, the second frost determination is performed by a process different from that in step S24.
[0038]
In this second frosting determination, if frosting has not occurred, the defrosting operation is forcibly terminated in step S30 and the process returns to step S21. If frost formation has occurred, a defrosting operation is executed in step S28, and the end of defrosting is determined in step S29. If the defrosting is not completed, the process returns to step S28, and if the defrosting is completed, the process proceeds to step S30. In this way, in step S27, the frost determination is performed even during the defrosting operation, and therefore, it is possible to suppress the decoloring defrosting as much as possible.
[0039]
FIG. 4 is a flowchart of the second embodiment corresponding to claim 1 and shows processing performed between steps S22 and S23 of FIG. In this process, an integration flag indicating whether the defrost mask timer is counting or not is used. The calculated temperature difference is the indoor heat exchanger temperature Tc−the room temperature Ta, the temperature difference setting value corresponding to the outside air temperature at which frost formation does not occur is, for example, 20 ° C., and the upper limit value of the maximum temperature difference is, for example, 18 ° C. . When the heating operation is started in step S22, it is determined in step S31 whether the calculated temperature difference is less than the temperature difference set value. If the determination is no, the integration flag is reset in step S32, and the process proceeds to step S23 without measuring the defrost mask timer in step S33. In step S23, it is determined whether the defrost mask timer has ended. Therefore, after step S33, it is determined in step S23 that it has not ended and the process proceeds to step S22.
[0040]
If the determination in step S31 is yes (calculated temperature difference <temperature difference set value), it is determined in step S34 whether the calculated temperature difference is less than the upper limit value of the maximum temperature difference. If the determination is no, the state of the integration flag is determined in step S35. If the flag is not set, the process proceeds to step S33. If the flag is set, the defrost mask timer is integrated in step S37, and step S23 is performed. Proceed to If the determination in step S34 is yes (calculated temperature difference <upper limit value of maximum temperature difference), the integration flag is set in step S36 and the process proceeds to step S37.
[0041]
If the calculated temperature difference changes as shown in FIG. 5, the process proceeds from step S31 → S32 → S33 → S23 in the states (1) and (5) in the figure, and step S31 in the state (2) in the figure. → S34 → S35 → S33 → S23, and in any case, the defrosting mask timer is not stopped and the frost determination is not performed. On the other hand, in the state of (3) in the figure, the process proceeds from step S31 → S34 → S36 → S37 → S23, and in the state of (4) in the figure, the process proceeds from step S31 → S34 → S35 → S37 → S23. Since the time measurement of the frost mask timer is performed, if the time measurement is completed in step S23, the frost determination is performed in step S24 of FIG.
[0042]
In this way, the difference between the temperature difference set value (20 ° C. in this example) and the upper limit value of the maximum temperature difference (18 ° C. in this example) is set as a threshold, and the defrost mask timer is integrated / accumulated by this threshold. Since it is determined whether or not to carry out, for example, in the state of transition from (1) to (2) in FIG. 5 or in the state of (5), that is, when there is no possibility of frosting, no accumulation is performed. Since frosting determination itself is not performed, the defrosting drastically decreases. Of course, in areas where low-temperature and high-humidity conditions occur frequently, if the threshold is 0 ° C, that is, the maximum temperature difference upper limit value ← temperature difference set value, the defrosting operation is performed when the maximum temperature difference upper limit value is exceeded. It goes without saying that the mask time is integrated and the defrosting operation mask time is not integrated when the upper limit value of the maximum temperature difference is exceeded.
[0043]
Next, the embodiment of claim 2 and claim 3 will be described. In the embodiment of claim 2, when it is not less than −7 ° C. after 2 minutes from the start of defrosting, it is determined as “coloring”, On the other hand, the embodiment of claim 3 is a technique in which, after 2 minutes from the start of defrosting, monitoring is continued after the temperature falls below −7 ° C., and thereafter the defrosting is terminated when the temperature exceeds −7 ° C.
[0044]
FIG. 6 is a flowchart of the third embodiment corresponding to claims 2 and 3, and is a process replacing (replacing) steps S25 to S30 of FIG. When the defrosting operation is started in step S41, it is determined whether a predetermined time (for example, 2 minutes) has elapsed in step S42. If the determination is no, the process returns to step S41, and if the determination is yes, the indoor heat is determined in step S43. It is determined whether the exchanger temperature Tc is −7 ° C. or lower. If determination is no (Tc> -7 degreeC), a defrost operation will be complete | finished by step S46, and it will return to step S21 of FIG. If the determination is yes (Tc ≦ −7 ° C.), the defrosting operation is executed in step S44, and the end of the defrosting is determined in step S45. If the defrosting is not completed, the process returns to step S44 (solid line arrow), and if the defrosting is completed, the process proceeds to step S46. The process of steps S45 → S43 → S46 corresponds to claim 2. That is, when the defrosting operation is performed in step S41 and the defrosting operation is performed, the indoor heat exchanger temperature Tc is equal to or lower than the predetermined temperature (−7 ° C.) even if a predetermined time (for example, 2 minutes) elapses. do not become. Therefore, the defrosting operation is forcibly terminated immediately at step S46. As a result, it is possible to suppress the blanking defrosting. In addition, if frost formation is moderate, the process of step S42->S43->S44-> S45 will be performed. Here, it is needless to say that step S45 is a determination of the completion of defrosting based on whether or not the defrosting operation time calculated and set based on the temperature difference ratio is the same as in step S16 of FIG.
[0045]
The broken line arrow shown in FIG. 6 is a process corresponding to claim 3. If the defrosting is not completed in step S45, the process returns to step S43 to determine the indoor heat exchanger temperature Tc.
That is, before the elapse of 2 minutes from the first defrosting operation, for example, when the indoor heat exchanger temperature Tc has already decreased to −7 ° C. or lower, the defrosting operation is executed in Step S44, and the defrosting is performed in Step S45. Determine termination. If the defrosting is not completed, the process returns to step S43 (broken arrow). If the defrosting is completed, the process proceeds to step S46, and the defrosting operation is terminated. That is, when it is not empty defrosting but there is little frost formation (colored feeling), step S42 → S43 (yes) → S44 → S45 (no: broken line) → S43 (yes) → (repeated) ... → The process of S43 (no) → S46 is performed. In this way, since the defrosting operation is terminated when the frosting is less and the state shifts to the empty defrosting state, a comfortable heating operation can be performed.
[0046]
FIG. 7 is a flowchart of the fourth embodiment corresponding to claim 4, and is a process replacing (replacing) steps S25 to S30 of FIG. When the defrosting operation is started in step S51, steps S51 and S52 are repeated until a predetermined time (for example, 60 seconds) elapses in step S53. In step S52, the method of decreasing the indoor heat exchanger temperature Tc every 10 seconds is calculated and stored in the memory. This process measures the measured value t while measuring the indoor heat exchanger temperature Tc every 10 seconds from the start of the defrosting operation. ₁₀ , T ₂₀ , ..., t ₆₀ For example, δt2 is calculated as a descending method 20 seconds after the start of the defrosting operation, and δt6 is calculated from the following equation as a descending method 60 seconds later.
δt2 = (t ₂₀ -T ₁₀ ) / 10
δt6 = (t ₆₀ -T ₅₀ ) / 10
[0047]
When a predetermined time has elapsed in step S53, it is determined in step S54 whether “δt2 ≧ δt6”. If this determination is yes, the temperature decrease is from a slow to abrupt, and if the determination is no, the temperature decrease is from a steep to slow. Since the indoor heat exchanger temperature Tc decreases when the defrosting operation is started, δt2 and δt6 have negative values (negative slope). If it is the former (yes), a defrost operation is performed in step S55, and the completion | finish of defrost is determined by step S56. If the defrosting is not finished, the process returns to step S55, and if the defrosting is finished, the defrosting operation is finished in step S57. In the latter case (no), the defrosting operation is terminated in step S57, and the process returns to step S21 in FIG.
[0048]
The above processing is processing corresponding to a temperature change as shown in FIG. That is, if the outdoor heat exchanger has frost formation, the indoor heat exchanger temperature Tc decreases from slow to steep, and in this case, the defrosting operation is continued. On the other hand, if there is no frost formation, the indoor heat exchanger temperature Tc decreases from steep to slow, and in this case, the defrosting operation is forcibly terminated. As a result, it is possible to suppress the blanking defrosting.
[0049]
FIG. 9 is a flowchart of the fifth embodiment corresponding to claims 5 and 6, and is a process replacing (replacing) steps S25 to S30 of FIG. When the defrosting operation is started in step S61, it is determined in step S62 whether the time is from evening to night. If the determination is no, a normal defrosting operation time is set in step S63 and the process proceeds to step S66. . If the determination is yes, it is determined in step S64 whether it is the first defrosting operation, and if it is not the first time, the process proceeds to step S63, and if it is the first time, it is 1/2 in the normal defrosting operation time in step S65. Is set as the defrosting operation time (initial defrosting operation time), and the process proceeds to step S66. In step S66, it is determined whether or not the set defrosting operation time has elapsed. If not, the process returns to step S61. If it has elapsed, the defrosting operation is terminated in step S67 and the process returns to step S21 in FIG. .
[0050]
In this way, since the first defrosting operation time is half of the normal defrosting operation time, even if it is in the state of empty defrosting, the time can be shortened, and the heating operation is immediately started. You can also Also, during the evening to night time, the outside air temperature is likely to suddenly drop, so it is easy to make an erroneous determination of frost formation. Can be.
[0051]
FIG. 10 is a flowchart of the sixth embodiment corresponding to claim 7 and is a process replacing (replacing) steps S22 to S24 in FIG. When the heating operation is started in step S71, it is determined in step S72 whether the heating operation is the second time. If the determination is no, the process proceeds to step S74 as it is, and if it is the second time, the defrost and defrost mask timer is set in step S73. The time is set to 1/2 and the process proceeds to step S74. Then, in step S74, it is determined whether the defrost mask timer has finished timing. If not completed, the process returns to step S71, and if completed, frost formation is determined in step S75. If it is not frosted, it will return to step S71, and if it has frosted, it will progress to step S25 of FIG. As described above, even when the first defrosting operation is insufficient, the next frosting determination is performed in half the time of the defrosting operation mask time (defrosting mask timer). There is frost.
[0052]
FIG. 11 is a flowchart of the seventh embodiment corresponding to the eighth aspect. First, it is monitored in step S81 that the heating operation can be performed, and if it can be performed, the heating operation is performed in steps S82 and S83 until the time of the defrost mask timer is finished. When the time measurement of the defrost mask timer ends, it is determined in step S84 whether it is the first pass after the time measurement ends (pass of the flow concerned). If it is the first pass, the process proceeds to step S85, and the second and subsequent passes. If so, the process proceeds to step S89. In addition, although the process of step S84 also has a process which uses a determination flag, it was set as the flowchart of the Example here. A specific example is described here. For example, the timer counts every 0.1 second and the defrost mask timer is set to 50 minutes. In the process of step S83 (determined every 0.1 seconds), if the time is less than 50 minutes, it is no and the process returns to step S82. Next, when it has just counted 50 minutes, it becomes yes and proceeds to step S84. In this case, since it is the first pass after the completion of timing, it becomes yes and proceeds to step S85. Note that S83 (yes) → S84 (yes) can be passed only once. In the next S85 (yes), continuous defrosting is selected, and in S85 (no), non-continuous defrosting is selected. Next, if the determination in step S85 is yes, the processing corresponding to claim 8, that is, “continuous defrosting”, the processing of steps S85 → S86 → S87 → S88 → S92 is performed. On the other hand, if the determination in step S85 is no, the process returns to step S82. Next, in step S83, 0.1 second has elapsed since 50 minutes, so the answer is yes and the process proceeds to step S84. However, in step S84, since it is the second pass at 50 minutes and 0.1 seconds, it becomes no and the process proceeds to step S89. The process at step S89 is “non-continuous defrosting”, and is the same as the process of the above-described embodiment including steps S90 and S91.
[0053]
Here, in the process of the seventh embodiment, the temperature difference ΔT (= Tc−Ta) at the beginning of the heating operation is stored as the maximum temperature difference ΔTmax, and the ratio βn of the temperature difference ΔT with respect to the maximum temperature difference ΔTmax is obtained. Then, the ratio of the temperature difference is compared with a preset ratio, and if the ratio of the temperature difference is equal to or less than the preset ratio, the defrosting operation time is shortened / decreased according to the magnitude of the ratio of the temperature difference. Set to long. Furthermore, when it is determined that frost has been formed by the frost determination, the defrosting operation is executed and terminated, and the defrosting operation is repeated so that the next frost determination is also determined to have frost (continuous). The number of times of repeated frosting is counted as the number of times of continuous defrosting. The defrosting operation time is changed between the case where the defrosting operation is repeated continuously (hereinafter referred to as “continuous defrosting”) and the case where the process is not repeated (hereinafter referred to as “non-continuous defrosting”). Like that. It is assumed that the number of continuous defrosting has been reset to “0” by default. Needless to say, for example, when the defrost mask timer is 50 minutes, “defrost operation” is performed when it is determined that frost is formed every 50 minutes, and low temperature / high humidity Appears in the case of severe conditions. In cases other than the above, the process of “non-continuous defrosting” is performed.
[0054]
That is, in the case of “continuous defrosting”, the defrosting operation time calculated by the ratio βn is set as it is by the route of step S84 → S85 → S86 → S87 → S91 for the first time, but the second and subsequent steps By the route of S84 → S85 → S86 → S87 → S88, the defrosting operation time calculated by the ratio βn is added and set (number of times of continuous defrosting−1). As a result, the second continuous defrost operation time is (defrost operation time set by βn + 1) minutes, and the third continuous defrost operation time is (defrost operation time set by βn + 2) minutes. In the fourth consecutive time, the defrosting operation time is (defrosting operation time set by βn + 3) minutes. And execution and completion | finish of a defrost operation are performed by step S92, S93, S94. In the case of “non-continuous defrosting”, the process of steps S84 (yes) → S85 (no) → S82 → S83 → S84 (no) is always executed. In step S89, the frost determination is performed. If no, the process returns to step S82. If yes, in step S90 (because non-continuous defrosting), the number of times of continuous defrosting is set to 0, and then the removal calculated by the ratio βn in step S91. The frost operation time is set, and the defrost operation is executed and terminated in steps S92, S93, and S94.
[0055]
【The invention's effect】
According to the air conditioner of the first aspect, after the heating operation is started, the frosting determination is performed on the condition that the integration of the defrosting operation mask time is completed. Without being affected by the descent / slight rise, the macroscopic descent / rise is recognized based on the threshold value, and “accumulate / do not accumulate” is determined. Opportunities for determining frost formation are reduced, so that the amount of defrosting drastically decreases. Therefore, the comfort during heating operation can be improved.
[0056]
According to the air conditioner of the second aspect, after the defrosting operation is started, when the indoor heat exchanger temperature is not lower than the predetermined temperature after the elapse of a predetermined time, the defrosting operation is ended and the heating operation is resumed. So comfort can be improved.
[0057]
According to the air conditioner of the third aspect, at the time of defrosting operation when there is little frost formation, the defrosting operation is ended and the operation is returned to the heating operation at the time when the state is shifted to the beating-up defrosting state. Can be improved.
[0058]
According to the air conditioner of the fourth aspect, it is determined that the defrosting operation is in the defrosting operation, the defrosting operation is terminated, and the heating operation is resumed. Therefore, the comfort can be improved.
[0059]
According to the air conditioner of claim 5, since the first defrosting operation time is half of the normal time, even if it is in the state of defrosting, the time can be shortened and the heating operation is immediately performed. Because it returns to, comfort can be improved.
[0060]
According to the air conditioner of the sixth aspect, the same effect as that of the fifth aspect can be obtained, and this can be shortened even if the state of decolorization is achieved.
[0061]
According to the air conditioner of the seventh aspect, the same effect as that of the first, second, third, fourth, fifth or sixth aspect can be obtained, and even if the first defrosting operation is insufficient, the removal is not necessary. Since the frost formation determination of the next cycle is performed in half the frost operation mask time, a suitable defrosting operation and a comfortable heating operation can be performed.
[0062]
According to the air conditioner of claim 8, the set defrosting is also performed in the case where the defrosting operation is repeated, such as when the defrosting capability is reduced due to severe conditions of low temperature and high humidity or insufficient refrigerant. Operation time becomes sufficient, residual frost can be reduced, and reliability can be ensured.
[0063]
According to the air conditioner of the ninth aspect, since the frost determination is performed even during the defrosting operation, it is possible to suppress the defrosting as much as possible and to perform a comfortable heating operation.
[Brief description of the drawings]
FIG. 1 is an electric block diagram showing an example of a refrigeration cycle and its control device in an air conditioner according to an embodiment of the present invention.
FIG. 2 is a principle block diagram of the air conditioner.
FIG. 3 is a flowchart of a first example of an embodiment of the present invention.
FIG. 4 is a flowchart of a second example of the embodiment of the present invention.
FIG. 5 is a diagram showing an example of a change in calculated temperature difference in the second example of the embodiment of the present invention.
FIG. 6 is a flowchart of Example 3 of the embodiment of the present invention.
FIG. 7 is a flowchart of Example 4 of the embodiment of the present invention.
FIG. 8 is a diagram showing an example of a change in indoor heat exchanger temperature in the fourth example of the embodiment of the present invention.
FIG. 9 is a flowchart of Example 5 of the embodiment of the present invention.
FIG. 10 is a flowchart of Example 6 of the embodiment of the present invention.
FIG. 11 is a flowchart of Example 7 of the embodiment of the present invention.
FIG. 12 is a diagram illustrating an example of a state change of a heat exchanger temperature, a room temperature, and a temperature difference in the embodiment of the present invention.
FIG. 13 is a flowchart of a defrosting operation during a conventional heating operation.
FIG. 14 is a diagram showing an example of a conventional case where frost formation is normally detected without any disturbance.
FIG. 15 is a diagram showing an example of a conventional case where the defrosting is performed by sunset or the like.
[Explanation of symbols]
300 Indoor control unit
302,303 Temperature sensor
330 Microcomputer

Claims

A control process in which the processing unit of the control device calculates a temperature difference between the indoor heat exchanger temperature and the room temperature, and a control process in which after the heating operation is started, the frost determination of the outdoor heat exchanger is performed from the calculated temperature difference. In an air conditioner comprising:
The difference between the temperature difference set value corresponding to the outside air temperature at which frost formation does not occur and stored in the storage unit of the control device, and the upper limit value of the maximum temperature difference stored in the storage unit is set as a threshold, during heating operation, When the calculated temperature difference falls below the temperature difference set value and further falls below the upper limit value of the maximum temperature difference, the defrosting operation mask time is integrated,
An air conditioner that performs processing so that the defrosting operation mask time is not integrated when the calculated temperature difference exceeds an upper limit value of the maximum temperature difference and further exceeds the temperature difference set value.

A control process in which the processing unit of the control device calculates a temperature difference between the indoor heat exchanger temperature and the room temperature, and a control process in which after the heating operation is started, the frost determination of the outdoor heat exchanger is performed from the calculated temperature difference. In an air conditioner comprising:
After the defrosting operation is started by determining the presence of frosting by the frosting determination, when the indoor heat exchanger temperature is not lower than the predetermined temperature after a predetermined time has elapsed, the defrosting operation is terminated and the heating operation is started. An air conditioner characterized by returning.

A control process in which the processing unit of the control device calculates a temperature difference between the indoor heat exchanger temperature and the room temperature, and a control process in which after the heating operation is started, the frost determination of the outdoor heat exchanger is performed from the calculated temperature difference. In an air conditioner comprising:
After determining the presence of frost by the frost determination and starting the defrosting operation, when monitoring the indoor heat exchanger temperature from a predetermined time point, when the indoor heat exchanger temperature exceeds a predetermined temperature, An air conditioner characterized by ending the defrosting operation and returning to the heating operation.

A control process in which the processing unit of the control device calculates a temperature difference between the indoor heat exchanger temperature and the room temperature, and a control process in which after the heating operation is started, the frost determination of the outdoor heat exchanger is performed from the calculated temperature difference. In an air conditioner comprising:
After the defrosting operation is started by determining that frosting is present by the frosting determination, the defrosting operation is terminated when the temperature of the indoor heat exchanger temperature is changed from steep to slow after a predetermined time has elapsed. The air conditioner is characterized in that it returns to heating operation.

A control process in which the processing unit of the control device calculates a temperature difference between the indoor heat exchanger temperature and the room temperature, and a control process in which after the heating operation is started, the frost determination of the outdoor heat exchanger is performed from the calculated temperature difference. In an air conditioner comprising:
An initial defrosting operation time shorter than a normal defrosting operation time is provided, and after the first defrosting operation is started by determining that there is frosting by the frosting determination, the initial defrosting operation time has elapsed. An air conditioner characterized by ending the defrosting operation and returning to the heating operation.

6. The air conditioner according to claim 5, wherein the processing unit recognizes a time from evening to night and provides the initial defrosting operation time.

Defrosting after completing the defrosting operation mask time is determined to be frosted, and the first defrosting operation is performed, then the defrosting operation is terminated and the second heating operation is started. The air conditioner according to claim 1, 2, 3, 4, 5 or 6, wherein after the half of the defrosting operation mask time has elapsed, the frost determination of the outdoor heat exchanger is performed.

A control process in which the processing unit of the control device calculates a temperature difference between the indoor heat exchanger temperature and the room temperature, and a control process in which after the heating operation is started, the frost determination of the outdoor heat exchanger is performed from the calculated temperature difference. In an air conditioner comprising:
During the heating operation, frost determination is performed at the end of the defrost mask time, and it is determined by the frost determination that there is frost formation, the defrost operation is started, and then the defrost operation is ended and the operation is returned to the heating operation. When repeating the heating cycle, the defrosting operation is performed by adding a predetermined short time every heating cycle to the defrosting operation time calculated by the ratio of the temperature difference at the end of the defrosting mask time of the second and subsequent heating cycles. An air conditioner characterized by calculating time.

The indoor unit of the air conditioner is provided with two temperature sensors, and after starting the heating operation, based on the temperature difference calculated from the temperature detected by the two temperature sensors, the outdoor unit of the air conditioner In an air conditioner that determines frost formation,
After defrosting operation is started by determining the presence of frost by the frost determination, the frost determination is performed by a process different from the frost determination after elapse of a predetermined time. The air conditioner is characterized in that it ends and returns to heating operation.