JP3663692B2

JP3663692B2 - Air conditioner

Info

Publication number: JP3663692B2
Application number: JP27236195A
Authority: JP
Inventors: 直斉藤; 義浩田辺; 康雄今城; 功舟山; 克之青木
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1995-10-20
Filing date: 1995-10-20
Publication date: 2005-06-22
Anticipated expiration: 2015-10-20
Also published as: JPH09113034A

Description

【０００１】
【発明の属する技術分野】
この発明は、インバータ駆動する圧縮機を備えた空気調和機に係り、冷媒量を電子制御式膨張弁により制御するようにした空気調和機に関する。
【０００２】
【従来の技術】
室内側熱交換器５の入口出口温度差の時間的変化のうち傾きの反転を検出することにより、減圧弁４を制御する発明は、特開昭６０−１１０７５号公報に開示されている。また、運転周波数に応じた膨張弁４開度を設定し、室内側熱交換器５中間と出口温度検知センサー１１で検知された温度差に応じた弁開度指令信号を出力し、膨張弁４の弁開度を調整する発明は、特開昭５８−２０５０５７号公報に開示されている。
【０００３】
【発明が解決しようとする課題】
上記従来技術では、室内側熱交換器の入口と出口または中間と出口の温度差からスーパーヒート量を検知し冷媒流量を制御しており、湿った空気が室内機ケーシング内に吸入され風路壁、送風機、及び風向偏向板等に着露する限界の室内側熱交換器の過熱蒸気領域を直接検知しているわけではないので、負荷変動時及びガス不足時等に、吹き出し口から露が垂れたり飛んだりするという現象（以下、露飛び・露垂れ）が起こり得るという問題点があった。
【０００４】
この発明の空気調和機は、上記のような課題を解決するためになされたもので、露飛び・露垂れを完全に抑えることを目的としている。
【０００５】
また、従来の冷媒流量制御を減圧装置で行っている空気調和機では、もし減圧装置が故障した場合、故障した時点での減圧弁の位置によっては、圧縮機が液冷媒を吸入する液バックという現象を起こし、圧縮機の信頼性という面で問題があった。
【０００６】
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、圧縮機の信頼性の確保を目的としている。
【０００７】
また、サービス時に運転状況のみでは、電子制御式膨張弁の故障は把握しきれないという問題点があった。
【０００８】
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、サービス時の電子制御式膨張弁の正確な故障診断を目的としている。
【０００９】
【課題を解決するための手段】
この発明の請求項１の空気調和機において、圧縮機、２列パスパターンの室内側熱交換器、電子制御式膨張弁、室外側熱交換器で冷凍サイクルを成し、冷房運転時の２列パスパターンの室内側熱交換器の冷媒の流れる方向の入口及び過熱度が大きくしかも前記熱交換器の１列目に過熱蒸気領域を回り込ませない位置に冷媒量を制御する冷媒流量制御手段を設け、圧縮機がインバータ駆動する空気調和機であって、前記冷房運転時の２列パスパターンの室内側熱交換器の冷媒の流れる方向の入口及び過熱度が大きくしかも前記熱交換器の１列目に過熱蒸気領域を回り込ませない位置に設けたセンサーの温度差がある一定値を越えた場合冷媒流量を増やすものである。
【００１１】
この発明の請求項２の空気調和機において、圧縮機、２列の室内側熱交換器、電子制御式膨張弁、室外側熱交換器で冷凍サイクルを成し、、冷房運転時の２列の室内側熱交換器の冷媒の流れる方向の入口、過熱度が大きくしかも前記熱交換器の１列目に過熱蒸気領域を回り込ませない位置及び出口に冷媒の温度を検知するセンサーを設け、圧縮機がインバータ駆動する空気調和機であって、センサーの温度差がある一定値を越えた場合冷媒流量を増やすものである。
【００１６】
【発明の実施の形態】
発明の実施の形態１
以下、図１はこの発明の実施の形態１の冷凍サイクルの構成図を示すものである。１は圧縮機、２は電動機、３は室外側熱交換器、４は電子制御式膨張弁、５は室内側熱交換器である。６は周波数可変装置、７は制御装置、８は圧縮機１の吐出温度を検知するサーミスタ、９は室内側熱交換器５の入口温度を検知するサーミスタ、１０は室内側熱交換器５の中間温度を検知するサーミスタである。また、制御装置７は上記吐出温度検知サーミスタ８、入口温度検知サーミスタ９及び中間温度検知サーミスタ１０からの入力信号により記憶機能、演算機能およびこれらの機能を制御する制御部７１と、この制御部７１の出力信号（弁開度指令信号）に基づき電子制御式膨張弁４を作動させる弁駆動部７２とから構成される。
【００１７】
次に、この発明の実施の形態１の空気調和機の動作について詳細に説明する。周波数可変装置により圧縮機１の回転数を周波数制御して変化させれば、図２に示すように空気調和機の冷暖房能力を略比例的に変えることができる。そこで、図３、図４に示すように周波数可変装置６の出力周波数を例えば１００段階に変化させる場合、この１００段階のうち例えば１０段階ごとに区切り１０の周波数帯を設けた場合、その周波数帯で圧縮機１を回転させてそのときの最適膨張弁開度（PULn）、最適吐出温度（TDn）を実験等で求めておき、この各周波数帯に対する最適膨張弁開度（PULn）、最適吐出温度（TDn）を制御部７１に予め記憶させておく。周波数可変装置６の出力周波数が変化すれば、この変化後の周波数に対応した前記最適弁開度（PULn）を前記制御部７１で選択し、この選択値に応じた弁開度指令信号を制御部７１から出力して弁駆動部７２を介して電子制御式膨張弁４の開度を目標値と一致するように制御する。次いで、所定時間（例えば、数分間）経過してサイクルが安定した後、制御部７１ではサーミスタ８からの検出信号に基づき吐出温度と現周波数帯での設定吐出温度（TDn）との偏差量を算出してその偏差量に応じた弁開度指令信号を出力する。この出力信号に基づき電子制御式膨張弁が調整され、負荷変動に応じた冷媒流量に制御される。以上のようにして冷媒流量が制御される。
【００１８】
上記のような冷媒流量の制御のみでは（上記従来技術も同様）、大きな負荷変動時もしくは冷媒不足時等では最適な吐出温度（上記従来技術ではスーパーヒート量）が変化し、冷房運転時の室内側熱交換器において過熱蒸気領域が冷媒の流れる方向に対して出口から入口方向に向けて進行するか、もしくは略中間位置に部分的に現れる。そのため、その過熱蒸気領域の室内側熱交換器の部分を湿った空気が入り込み吹き出し口からの露垂れや、露飛びという現象を引き起こす。
【００１９】
そこで、この発明の実施の形態１では上記の冷媒流量制御に加えて、その現象を検知するために冷房運転時の室内側熱交換器の入口にサーミスタ９、略中間にサーミスタ１０を設置し（例えば図５（ａ）、（ｂ）に示すような２列の熱交換器の場合は過熱蒸気領域が基本的には出口方向から入口方向へと進み２列目から１列目へと回り込んでいく訳であるがその過熱蒸気領域を２列目までで進行を止め１列目まで進行させなければ１列目で湿った空気は除湿されエアコン内部に湿った空気が入り込むことはなくなり露飛び・露垂れが起こり得ない。センサーの位置として出口でなく略中間位置であるのは、１列目と２列目の熱交換や風速分布のアンバランス等によって過熱度が最も大きいポイントが出口とは限らないためであり、過熱度が最も大きくしかも最低限１列目に過熱蒸気領域を回り込ませない位置である必要があるので例えば図５（ａ）（ｂ）に示すような位置である。図５に示すパスパターン以外の場合も同様の考えである。）、上記のような現象が起こりやすい条件にて実験等を行いサーミスタ９とサーミスタ１０の温度差（TH１０-TH９＝ΔTH１０−９）が何度以上で（ΔTHk１０−９）、また何分続いた場合（Tk）に上記現象が起こるのかを求め、また目標吐出温度を何度まで下げれば（つまり膨張弁は開方向で流量を増やす方向であり過熱領域が減少する方向である）上記現象が解消されるかを図４に示すように上記周波数帯（TDk）ごとに求め、それぞれの値を制御部７１に記憶させておく。そして上記の冷媒流量制御時に常時その温度差ΔTH１０−９を検知し、その値が制御部７１に記憶させた値（ΔTHk１０−９）以上で、上記制御部に記憶させた時間（Tk）続いたならば、目標吐出温度をTDnからTDkへ変更し、制御部７１では現温度差（ΔTH１０−９）と設定温度差（ΔTHk１０−９）との偏差量(ΔTH１０−９-ΔTHk１０−９）とサーミスタ８から検出した現吐出温度（TD）と変更後の設定吐出温度（TDk）との偏差量(TD-TDk)をそれぞれ算出してそれに応じた弁開度信号を出力し、この信号に基づき電子制御式膨張弁４が開方向へと調整され、上記現象が起こるのを回避する。
【００２０】
図６は前記制御部７１のプログラムを示すフローチャートである。即ち、周波数可変装置６の出力周波数信号が制御部７１のブロック７１１に入力され、ブロック７１２に進む。ブロック７１２では吐出温度検知サーミスタ８、入口温度検知サーミスタ９、中間温度検知サーミスタ１０の温度検出信号が入力され、ブロック７１３に進む。ブロック７１３では前記周波数に対応する最適弁解度値（PULn）を選択し、ブロック７１４へ進む。ブロック７１４では前記周波数に対応する設定吐出温度がTDn か TDkどちらかを選択し、ブロック７１５へ進む。ブロック７１５では膨張弁４の制御開度を設定し（上記最適弁開度（PULn)＋下記補正弁解度（ΔPUL))それに応じた弁開度指令信号を出力する。その出力信号に基づき電子制御式膨張弁４の弁開度が調整される。ブロック７１６ではサイクル安定化時間（Tb）のカウントを行い前記時間Tb経過前と判断すればブロック７１１に戻り、前記時間Tbが経過したと判断すればブロック７１７に進む。ブロック７１７ではサーミスタ８から検出した現吐出温度（TD）と設定吐出温度（TDnもしくはTDk）との偏差量（TD-TDn もしくは TD-TDk）、サーミスタ９、１０から検出した上記現温度差（ΔTH１０−９）と上記設定温度差（ΔTHk１０−９）との偏差量(ΔTH１０−９-ΔTHk１０−９）を算出し、設定吐出温度がTDnのときは偏差量（TD-TDn）より、設定吐出温度がTDkのときは偏差量（TD-TDk）と偏差量(ΔTH１０−９-ΔTHk１０−９）よりそれに応じた補正弁開度（ΔPUL）を求め、ブロック７１１へ戻る。
【００２１】
図７は前記ブロック７１４の詳細である。上記現温度差（ΔTH１０−９）が上記設定温度差（ΔTHk１０−９）以上でかつ上記時間（Tk）続いたなら、設定吐出温度はTDkを選択し、それ以外の場合はTDnを選択する。
【００２２】
上記この発明の実施の形態１では、通常時の冷媒流量制御を吐出温度で行っている場合において説明したが、従来同様に室内側熱交換器の入口と出口又は略中間と出口との温度差でスーパーヒート量を検知することにより通常時の冷媒流量制御を行う場合においても、さらにもう一つセンサーを追加し（入口と出口にセンサーを設けている場合略は中間に、略中間と出口にセンサーを設けている場合は入口に）上記実施例同様に入口と略中間のセンサーの温度差から露飛び・露垂れの危険性を察知し、危険性があると判断した場合に電子制御式膨張弁の開度を開き冷媒流量を増やし過熱蒸気領域を減らすことにより、露飛び・露垂れを防ぐという方法でもかまわない。
【００２３】
上記のようにして、この発明では、室内側熱交換器の入口と略中間に温度感知センサーを取り付けその温度差を検知することにより、湿った空気が室内機ケーシング内に吸入され風路壁、送風機、及び風向偏向板等に着露が起こりうる蒸発器の過熱蒸気領域を直接検知することができるので、露飛び・露垂れを確実に防ぐことができる。
【００２４】
発明の実施の形態２
以下、図８はこの発明の実施の形態２の構成図を示す。１は圧縮機、２は電動機、３は室外側熱交換器、４は電子制御式膨張弁、５は室内側熱交換器である。６は周波数可変装置、７は制御装置、８はサーミスタである。また、制御装置は、記憶機能、演算機能およびこれらの機能を制御する制御部７１と制御部７１の出力信号（弁開度指令信号）に基づき電子制御式膨張弁４を作動する弁駆動部７２とから構成される。
【００２５】
次に、この発明の実施の形態２における空気調和機の動作について詳細に説明する。図２に示すように、周波数可変装置により圧縮機１の回転数を周波数制御して変化させれば、空気調和機の冷暖房能力を略比例的に変えることができる。そこで、図３、図４に示すように周波数可変装置６の出力周波数を例えば１００段階に変化させる場合、この１００段階のうち例えば１０段階ごとに区切り１０の周波数帯を設けた場合、その周波数帯で圧縮機１を回転させてそのときの最適膨張弁開度（PULn）、最適吐出温度（TDn）を実験等で求めておき）、この各周波数帯に対する最適膨張弁開度（PULn）、最適吐出温度（TDn）を制御部７１に予め記憶させておく。周波数可変装置６の出力周波数が変化すれば、この変化後の周波数に対応した前記最適弁開度（PULn）を前記制御部７１で選択し、この選択値に応じた弁開度指令信号を制御部７１から出力して弁駆動部７２を介して電子制御式膨張弁４の開度を目標値と一致するように制御する。次いで、所定時間（例えば、数分間）経過してサイクルが安定した後、制御部７１では温度検出器８からの検出信号に基づき吐出温度と現周波数帯での設定吐出温度（TDn）との偏差量を算出してその偏差量に応じた弁開度指令信号を出力する。この出力信号に基づき電子制御式膨張弁が調整され、負荷変動に応じた冷媒流量に制御される。以上のようにして冷媒流量が制御される。
【００２６】
以上の冷媒量制御に加えて、この発明の実施の形態２では、電子制御式膨張弁の故障が起きた場合（例えば、メカ部故障、駆動部故障、配線不良等）、弁の止まった位置によっては、圧縮機液バック運転によって圧縮機が故障する恐れがあるため、それを防ぐためにその危険性があると判断した場合圧縮機の最大周波数を変更するという制御が加えられている。
【００２７】
以下、図に基づき詳細に述べる。膨張弁４が故障した場合、上記の冷媒流量制御において、制御部７１から駆動部７２へ膨張弁を閉方向の信号が出力されても吐出温度（TH８）は上昇してこない。そのため、故障したときの膨張弁の弁の位置によっては目標吐出温度まで上がらずに制御部７１は閉方向への信号を出力し続けることになる。
そこで、圧縮機が液バック運転を何Ｈｚ以上（HZl）で何分間（Tl）運転した場合圧縮機の故障の危険性が生じるか、何Ｈｚ以下（HZg）で運転すれば確実にその危険性が無くなるかを信頼性の実験等で求め、予め制御部７１に記憶させておく。また、液バック運転であると判断する吐出温度（TDl）、何パルス以下で故障であると判断するかその開度（PULl）も予め制御部７１に記憶させておく。つまり、冷暖房運転中にTH８がTl以下で、かつ制御部７１の開度指令信号がPULl以下で、かつ運転周波数がHZl以上である状態がTl分以上続いた場合に、制御部７１で運転周波数の最大をHZgに変更し、圧縮機が故障するという危険性を回避する。
【００２８】
図９は前記制御部７１のプログラムを示すフローチャートである。即ち、制御部７１のブロック７１０では上記最大周波数の規制をするか否かを判断する。規制を行うと判断した場合は、その最大周波数規制信号を周波数可変装置６に出力しその結果圧縮機１の回転数が制御される。ブロック７１１では、周波数可変装置６の出力周波数信号が入力され、ブロック７１２に進む。ブロック７１２ではサーミスタ８の温度検出信号が入力され、ブロック７１３に進む。ブロック７１３では前記周波数に対応する最適弁解度値（PULn）を選択し、ブロック７１４へ進む。ブロック７１４では前記周波数に対応する設定吐出温度（TDn）を選択し、ブロック７１５へ進む。ブロック７１５では膨張弁４の制御開度を設定し（上記最適弁開度（PULn)＋下記補正弁解度（ΔPUL))それに応じた弁開度指令信号を出力する。その出力信号に基づき電子制御式膨張弁４の弁開度が調整される。ブロック７１６ではサイクル安定化時間（Tb）のカウントを行い前記時間Tb経過前と判断すればブロック７１０に戻り、前記時間Tbが経過したと判断すればブロック７１７に進む。ブロック７１７ではサーミスタ８から検出した現吐出温度（TD）と設定吐出温度（TDn）との偏差量（TD-TDn ）を算出し、それに応じた補正弁開度（ΔPUL）を求め、ブロック７１０へ戻る。
【００２９】
図１０はブロック７１０の詳細図である。即ち、サーミスタ８の温度（TH８）が上記TDl以下かつ弁開度指令信号が上記PULl以下かつ運転周波数がHZl以上である状態がTl以上続いた場合最大周波数をHZgに規制する。それ以外の場合は規制は行わない。
【００３０】
上記のようにして、この発明の実施の形態２では、電子制御式膨張弁の故障が起きた場合、弁の止まった位置によっては、圧縮機液バック運転によって圧縮機が故障する恐れがあるため、圧縮機の周波数及び弁の開度及び圧縮機の吐出温度から圧縮機の運転状態を推定し、圧縮機の最大周波数を規制することにより、圧縮機の信頼性を高めることの成功している。
【００３１】
なお、この様な状態は必ずしも膨張弁の故障とは限らず、例えば、外気温が非常に低い場合も起こり得る。そのために、圧縮機の停止はせずに、圧縮機のベーン飛び、圧縮機からの油の持ち出し量、圧縮機の軸負荷等が圧縮機にとって有利な低速回転で運転することにより対処している。
【００３２】
発明の実施の形態３
以下、図１１はこの発明の実施の形態３の構成図を示す。１は圧縮機、２は電動機、３は室外側熱交換器、４は電子制御式膨張弁、５は室内側熱交換器である。６は周波数可変装置、７は制御装置である。また、制御装置７は、記憶機能、演算機能およびこれらの機能を制御する制御部７１と制御部７１の出力信号（弁開度指令信号）に基づき電子制御式膨張弁４を作動する弁駆動部７２とから構成される。
【００３３】
上記のようなこの発明の実施の形態３の冷媒回路構成を用いた空気調和機では、冷媒流量制御を上記圧縮機２と上記電子制御式膨張弁４で行っているため、電子制御式膨張弁が故障した場合には冷媒流量の制御が不可能になる。しかし、サービス時にその電子制御式膨張弁の故障は運転状況のみでは正確な故障診断ができないため、実際に膨張弁が駆動していることを確認する必要がある。そこで、電子制御式膨張弁が、開方向に通電され駆動した場合全開時に、カチッ、カチッと音がすることを利用して、サービス時の故障診断モードとして開方向通電を行い、音によって故障の判定を行う。音がした場合は、電子制御式膨張は、駆動しているので正常であり、音がしない場合は、故障である。
【００３４】
次に、電子制御式膨張弁が全開時に音がする仕組みの例を図１２を基に説明する。図１２は電子制御式膨張弁の一例の断面図である。駆動原理を簡単に説明すると、図に示した部分はステッピングモータになっておりローター１１が回転し、その回転動作は、ねじにより上下運動に変換され、弁１２に開閉運動を与える仕組みになっている。そして、弁が開方向へ進んでいくとローターについている突起部Ａ１３は、突起部Ｂ１４に接触し音が発する様になっている。
【００３５】
上記のようにして、この発明の実施の形態３では、サービス時に開方向通電を行い、電子制御式膨張弁の全開時に発生する音を確認することにより、確実な故障診断ができるようになる。
【００３６】
【発明の効果】
請求項１の空気調和機において、圧縮機、２列の室内側熱交換器、電子制御式膨張弁、室外側熱交換器で冷凍サイクルを成し、冷房運転時の２列の室内側熱交換器の冷媒の流れる方向の入口及び過熱度が大きくしかも前記熱交換器の１列目に過熱蒸気領域を回り込ませない位置に冷媒量を制御する冷媒流量制御手段を設け、圧縮機がインバータ駆動する空気調和機において、前記冷房運転時の２列の室内側熱交換器の冷媒の流れる方向の入口及び過熱度が大きくしかも前記熱交換器の１列目に過熱蒸気領域を回り込ませない位置に設けたセンサーの温度差がある一定値を越えた場合冷媒流量を増やすようにしたから、湿った空気が室内機ケーシング内に吸入され風路壁、送風機及び風向変更板などに着露が起こり得る室内側熱交換器の過熱蒸気領域を直接検知でき、露飛び・露垂れを確実に防ぐといともに、露飛び・露垂れの危険性を察知しその危険性を回避する効果を奏する。
【００３８】
請求項２の空気調和機において、圧縮機、２列の室内側熱交換器、電子制御式膨張弁、室外側熱交換器で冷凍サイクルを成し、、冷房運転時の２列の室内側熱交換器の冷媒の流れる方向の入口、過熱度が大きくしかも前記熱交換器の１列目に過熱蒸気領域を回り込ませない位置及び出口に冷媒の温度を検知するセンサーを設け、圧縮機がインバータ駆動する空気調和機であって、センサーの温度差がある一定値を越えた場合、冷媒流量を増やすようにしたから、室内熱交換器の入口と略中間のセンサーの温度差から露飛び、露垂れの危険性を察知しその危険性を回避するとともに、過熱蒸気領域を減らし露飛び、露垂れを防ぐ効果を有する。
【図面の簡単な説明】
【図１】この発明の実施の形態１を示す空気調和機の構成図。
【図２】この発明の実施の形態１、実施の形態２を示す空気調和機の周波数と能力の関係説明図。
【図３】この発明の実施の形態１、実施の形態２を示す空気調和機の周波数と設定最適弁開度値の関係説明図。
【図４】この発明の実施の形態１、実施の形態２を示す空気調和機の周波数と設定吐出温度の関係説明図。
【図５】この発明の実施の形態１を示す入口サーミスタ及び中間サーミスタの位置関係を示す詳細図。
【図６】この発明の実施の形態１を示す制御フローチャート。
【図７】図６のブロック７１４の詳細を示すフローチャート。
【図８】この発明の実施の形態２を示す空気調和機の構成図。
【図９】この発明の実施の形態２を示す制御フローチャート。
【図１０】図９のブロック７１０の詳細を示すフローチャート。
【図１１】この発明の実施の形態３を示す空気調和機の構成図
【図１２】この発明の実施の形態３を示す電子制御式膨張弁の断面図。
【図１３】従来の技術を示す空気調和機の構成図。
【符号の説明】
１：圧縮機、２：電動機、３：室外側熱交換器、４：電子制御式膨張弁、５：室内側熱交換器、６：周波数可変装置、７：制御装置、８：吐出温度検出サーミスタ、９：入口温度検出サーミスタ、１０：中間温度検出サーミスタ、[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air conditioner including a compressor driven by an inverter, and relates to an air conditioner in which the amount of refrigerant is controlled by an electronically controlled expansion valve.
[0002]
[Prior art]
Japanese Patent Laid-Open No. 60-11075 discloses an invention for controlling the pressure-reducing valve 4 by detecting a reversal of the inclination in the temporal change of the inlet / outlet temperature difference of the indoor heat exchanger 5. Further, the opening degree of the expansion valve 4 corresponding to the operating frequency is set, a valve opening degree command signal corresponding to the temperature difference detected by the middle of the indoor heat exchanger 5 and the outlet temperature detection sensor 11 is output, and the expansion valve 4 An invention for adjusting the valve opening is disclosed in Japanese Patent Laid-Open No. 58-205057.
[0003]
[Problems to be solved by the invention]
In the above prior art, the amount of superheat is detected from the temperature difference between the inlet and outlet of the indoor heat exchanger or between the middle and outlet, and the refrigerant flow rate is controlled. Because it does not directly detect the superheated steam area of the indoor heat exchanger, which is the limit of dew condensation on the blower, wind direction deflector, etc., dew drips from the outlet when the load fluctuates or when the gas is insufficient. There was a problem that a phenomenon of flying or flying (hereinafter, dew flying or dripping) could occur.
[0004]
The air conditioner of the present invention has been made in order to solve the above-described problems, and aims to completely suppress dewdrops and dripping.
[0005]
Also, in an air conditioner in which conventional refrigerant flow control is performed by a decompression device, if the decompression device fails, depending on the position of the decompression valve at the time of failure, the compressor is referred to as a liquid back that sucks liquid refrigerant The phenomenon occurred and there was a problem in terms of the reliability of the compressor.
[0006]
The present invention has been made to solve the above-described problems, and aims to ensure the reliability of the compressor.
[0007]
In addition, there is a problem that the failure of the electronically controlled expansion valve cannot be grasped only by the operating state at the time of service.
[0008]
The present invention has been made to solve the above-described problems, and has an object of accurately diagnosing a failure of an electronically controlled expansion valve at the time of service.
[0009]
[Means for Solving the Problems]
The air conditioner of claim 1 of the present invention, a compressor, an indoor heat exchanger of the second column pass pattern, electronically controlled expansion valve, forms a refrigeration cycle in the outdoor side heat exchanger, two rows of cooling operation A refrigerant flow rate control means for controlling the refrigerant amount at a position where the superheat degree is large and the superheated steam region is not circulated in the first row of the heat exchanger is provided in the path pattern indoor heat exchanger in the flow direction of the refrigerant. The compressor is an inverter-driven air conditioner that has a large inlet and superheat degree in the direction in which the refrigerant flows in the indoor heat exchanger of the two-row path pattern during the cooling operation, and is the first row of the heat exchanger. When the temperature difference of the sensor provided at a position where the superheated steam area does not go around exceeds a certain value, the refrigerant flow rate is increased.
[0011]
In the air conditioner according to claim 2 of the present invention, a compressor, two rows of indoor heat exchangers, an electronically controlled expansion valve, and an outdoor heat exchanger form a refrigeration cycle, and two rows during cooling operation are formed. A compressor for detecting the temperature of the refrigerant is provided at the inlet of the indoor heat exchanger in the flow direction of the refrigerant, at a position where the superheat degree is large and the superheated steam region is not circulated in the first row of the heat exchanger, and at the outlet. Is an inverter-driven air conditioner that increases the refrigerant flow rate when the temperature difference of the sensors exceeds a certain value.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 of the Invention
FIG. 1 is a block diagram showing a refrigeration cycle according to Embodiment 1 of the present invention. 1 is a compressor, 2 is an electric motor, 3 is an outdoor heat exchanger, 4 is an electronically controlled expansion valve, and 5 is an indoor heat exchanger. 6 is a frequency variable device, 7 is a control device, 8 is a thermistor that detects the discharge temperature of the compressor 1, 9 is a thermistor that detects the inlet temperature of the indoor heat exchanger 5, and 10 is the middle of the indoor heat exchanger 5. This is a thermistor that detects temperature. In addition, the control device 7 includes a control unit 71 that controls a storage function, a calculation function, and these functions based on input signals from the discharge temperature detection thermistor 8, the inlet temperature detection thermistor 9, and the intermediate temperature detection thermistor 10, and the control unit 71. The valve drive unit 72 operates the electronically controlled expansion valve 4 based on the output signal (valve opening command signal).
[0017]
Next, the operation of the air conditioner according to Embodiment 1 of the present invention will be described in detail. If the rotation speed of the compressor 1 is changed by controlling the frequency by the frequency variable device, the air conditioning capacity of the air conditioner can be changed approximately proportionally as shown in FIG. Therefore, when the output frequency of the frequency variable device 6 is changed to, for example, 100 steps as shown in FIGS. 3 and 4, when 10 frequency bands are provided for every 10 steps among the 100 steps, the frequency band is set. Rotate the compressor 1 and obtain the optimal expansion valve opening (PULn) and optimal discharge temperature (TDn) at that time through experiments, etc., and determine the optimal expansion valve opening (PULn) and optimal discharge for each frequency band. The temperature (TDn) is stored in the control unit 71 in advance. When the output frequency of the frequency variable device 6 changes, the optimum valve opening (PULn) corresponding to the changed frequency is selected by the control unit 71, and the valve opening command signal corresponding to the selected value is controlled. The opening degree of the electronically controlled expansion valve 4 is controlled so as to match the target value via the valve drive unit 72 output from the unit 71. Next, after a predetermined time (for example, several minutes) elapses and the cycle is stabilized, the control unit 71 determines the deviation amount between the discharge temperature and the set discharge temperature (TDn) in the current frequency band based on the detection signal from the thermistor 8. A valve opening command signal corresponding to the calculated deviation amount is output. The electronically controlled expansion valve is adjusted based on this output signal, and the refrigerant flow rate is controlled according to the load fluctuation. The refrigerant flow rate is controlled as described above.
[0018]
With only the control of the refrigerant flow rate as described above (same as in the above prior art), the optimum discharge temperature (superheat amount in the above prior art) changes when there is a large load fluctuation or when the refrigerant is insufficient, etc. In the inner heat exchanger, the superheated steam region advances from the outlet toward the inlet with respect to the direction in which the refrigerant flows, or partially appears at a substantially intermediate position. For this reason, moist air enters the indoor heat exchanger portion of the superheated steam region, causing a phenomenon of dew dripping from the outlet and dew splattering.
[0019]
Therefore, in the first embodiment of the present invention, in addition to the refrigerant flow rate control described above, a thermistor 9 is installed at the inlet of the indoor heat exchanger during cooling operation, and the thermistor 10 is installed approximately in the middle in order to detect the phenomenon ( For example, in the case of two rows of heat exchangers as shown in FIGS. 5 (a) and 5 (b), the superheated steam region basically advances from the outlet direction to the inlet direction, and wraps around from the second row to the first row. However, if the superheated steam area stops at the second row and does not advance to the first row, the moist air in the first row is dehumidified and the moist air does not enter the air conditioner.・ Dew dripping cannot occur.The sensor position is not at the exit, but at a substantially intermediate position.The point where the degree of superheat is the largest due to heat exchange in the first and second rows, imbalance in the wind speed distribution, etc. This is because there is no limit. For example, the position is as shown in Fig. 5 (a) and Fig. 5 (b) because it is necessary to be a position that does not wrap around the superheated steam region in the first row at least. The experiment is performed under the condition where the above phenomenon is likely to occur, and the temperature difference (TH10−TH9 = ΔTH10−9) between the thermistor 9 and the thermistor 10 is more than (ΔTHk10−9), Also, determine how many minutes (Tk) the above phenomenon occurs, and if the target discharge temperature is lowered to how many times (that is, the expansion valve is in the direction of increasing the flow rate in the opening direction and the direction of decreasing the overheating region) 4) Whether the above phenomenon is eliminated is obtained for each frequency band (TDk) as shown in FIG. 4, and each value is stored in the control unit 71. The temperature difference ΔTH10-9 is always detected during the refrigerant flow control, and the value is equal to or greater than the value (ΔTHk10-9) stored in the control unit 71, and the time (Tk) stored in the control unit continues. Then, the target discharge temperature is changed from TDn to TDk, and the controller 71 determines the deviation amount (ΔTH10-9-ΔTHk10-9) between the current temperature difference (ΔTH10-9) and the set temperature difference (ΔTHk10-9) and the thermistor. 8 calculates the deviation (TD-TDk) between the current discharge temperature (TD) detected from 8 and the set discharge temperature (TDk) after change, and outputs the valve opening signal accordingly. The controlled expansion valve 4 is adjusted in the opening direction to avoid the above phenomenon.
[0020]
FIG. 6 is a flowchart showing a program of the control unit 71. That is, the output frequency signal of the frequency variable device 6 is input to the block 711 of the control unit 71, and the process proceeds to block 712. In block 712, the temperature detection signals of the discharge temperature detection thermistor 8, the inlet temperature detection thermistor 9, and the intermediate temperature detection thermistor 10 are input, and the flow proceeds to block 713. In block 713, an optimum valve solution value (PULn) corresponding to the frequency is selected, and the flow proceeds to block 714. In block 714, the set discharge temperature corresponding to the frequency is selected from TDn or TDk, and the process proceeds to block 715. In block 715, the control opening degree of the expansion valve 4 is set (the above-mentioned optimum valve opening degree (PULn) + the following corrected valve solution degree (ΔPUL)), and a valve opening degree command signal corresponding thereto is output. Based on the output signal, the opening degree of the electronically controlled expansion valve 4 is adjusted. In block 716, the cycle stabilization time (Tb) is counted. If it is determined that the time Tb has not elapsed, the process returns to block 711. If it is determined that the time Tb has elapsed, the process proceeds to block 717. In block 717, the deviation (TD-TDn or TD-TDk) between the current discharge temperature (TD) detected from the thermistor 8 and the set discharge temperature (TDn or TDk), the current temperature difference (ΔTH10) detected from the thermistors 9 and 10 -9) and the set temperature difference (ΔTHk10-9) is calculated (ΔTH10-9-ΔTHk10-9). When the set discharge temperature is TDn, the set discharge temperature is calculated from the deviation (TD-TDn). When TDk is TDk, a correction valve opening degree (ΔPUL) corresponding to the deviation amount (TD-TDk) and deviation amount (ΔTH10-9-ΔTHk10-9) is obtained, and the processing returns to block 711.
[0021]
FIG. 7 shows details of the block 714. If the current temperature difference (ΔTH10-9) is equal to or greater than the set temperature difference (ΔTHk10-9) and continues for the time (Tk), the set discharge temperature is selected as TDk, otherwise, TDn is selected.
[0022]
The first embodiment of the present invention has been described in the case where the refrigerant flow rate control at the normal time is performed at the discharge temperature. However, the temperature difference between the inlet and outlet of the indoor heat exchanger or the substantially middle and outlet is the same as in the past. Even when controlling the flow rate of refrigerant at normal time by detecting the amount of superheat at the top, add another sensor (if the sensor is provided at the inlet and outlet, it is roughly in the middle, and roughly in the middle and outlet Like the above example, the sensor is installed at the inlet) Like the above example, the temperature difference between the sensor and the middle of the sensor is used to detect the risk of dew and dripping. A method of preventing dew stagnation and dripping by opening the valve opening and increasing the refrigerant flow rate to reduce the superheated steam region may be used.
[0023]
As described above, in the present invention, by attaching a temperature detection sensor approximately in the middle of the inlet of the indoor heat exchanger and detecting the temperature difference, the humid air is sucked into the indoor unit casing and the air passage wall, Since it is possible to directly detect the superheated steam region of the evaporator in which dew condensation may occur on the blower, the wind direction deflecting plate, and the like, it is possible to reliably prevent dew jumping and dripping.
[0024]
Embodiment 2 of the Invention
FIG. 8 is a configuration diagram of the second embodiment of the present invention. 1 is a compressor, 2 is an electric motor, 3 is an outdoor heat exchanger, 4 is an electronically controlled expansion valve, and 5 is an indoor heat exchanger. 6 is a frequency variable device, 7 is a control device, and 8 is a thermistor. The control device also includes a storage function, an arithmetic function, a control unit 71 that controls these functions, and a valve drive unit 72 that operates the electronically controlled expansion valve 4 based on an output signal (valve opening command signal) of the control unit 71. It consists of.
[0025]
Next, the operation of the air conditioner according to Embodiment 2 of the present invention will be described in detail. As shown in FIG. 2, if the frequency of the compressor 1 is changed by frequency control using a frequency variable device, the air conditioning capacity of the air conditioner can be changed approximately proportionally. Therefore, when the output frequency of the frequency variable device 6 is changed to, for example, 100 steps as shown in FIGS. 3 and 4, when 10 frequency bands are provided for every 10 steps among the 100 steps, the frequency band is set. Rotate the compressor 1 and obtain the optimum expansion valve opening (PULn) and optimum discharge temperature (TDn) at that time by experiment etc.), the optimum expansion valve opening (PULn) and optimum for each frequency band The discharge temperature (TDn) is stored in the control unit 71 in advance. When the output frequency of the frequency variable device 6 changes, the optimum valve opening (PULn) corresponding to the changed frequency is selected by the control unit 71, and the valve opening command signal corresponding to the selected value is controlled. The opening degree of the electronically controlled expansion valve 4 is controlled so as to match the target value via the valve drive unit 72 output from the unit 71. Next, after a predetermined time (for example, several minutes) has passed and the cycle is stabilized, the controller 71 makes a deviation between the discharge temperature and the set discharge temperature (TDn) in the current frequency band based on the detection signal from the temperature detector 8. An amount is calculated and a valve opening command signal corresponding to the deviation is output. The electronically controlled expansion valve is adjusted based on this output signal, and the refrigerant flow rate is controlled according to the load fluctuation. The refrigerant flow rate is controlled as described above.
[0026]
In addition to the above refrigerant amount control, in Embodiment 2 of the present invention, when a failure of the electronically controlled expansion valve occurs (for example, mechanical part failure, drive part failure, wiring failure, etc.), the position where the valve stops In some cases, the compressor may be damaged due to the compressor liquid back operation, and in order to prevent this, control is performed to change the maximum frequency of the compressor when it is determined that there is a risk.
[0027]
Hereinafter, it will be described in detail with reference to the drawings. When the expansion valve 4 fails, the discharge temperature (TH8) does not rise even if a signal for closing the expansion valve is output from the control unit 71 to the drive unit 72 in the refrigerant flow control described above. Therefore, depending on the position of the expansion valve at the time of failure, the control unit 71 continues to output a signal in the closing direction without rising to the target discharge temperature.
Therefore, how many Hz (HZl) and how many minutes (Tl) the compressor performs the liquid back operation may cause a compressor failure, or how many Hz or less (HZg) it will do. Is determined by reliability experiments or the like, and stored in the control unit 71 in advance. In addition, the discharge temperature (TDl) at which it is determined that the liquid back operation is performed and the opening degree (PULl) at which the number of pulses is determined as the failure are stored in the control unit 71 in advance. That is, when TH8 is equal to or less than Tl, the opening command signal of the control unit 71 is equal to or less than PULl, and the operation frequency is equal to or greater than HZl during the cooling / heating operation, the control unit 71 performs the operation frequency. Change the maximum to HZg to avoid the risk of compressor failure.
[0028]
FIG. 9 is a flowchart showing a program of the control unit 71. That is, in block 710 of the control unit 71, it is determined whether or not the maximum frequency is restricted. When it is determined that the restriction is to be performed, the maximum frequency restriction signal is output to the frequency variable device 6 and, as a result, the rotational speed of the compressor 1 is controlled. In block 711, the output frequency signal of the frequency variable device 6 is input, and the process proceeds to block 712. In block 712, the temperature detection signal of the thermistor 8 is input, and the process proceeds to block 713. In block 713, an optimum valve solution value (PULn) corresponding to the frequency is selected, and the flow proceeds to block 714. In block 714, the set discharge temperature (TDn) corresponding to the frequency is selected, and the process proceeds to block 715. In block 715, the control opening degree of the expansion valve 4 is set (the above-mentioned optimum valve opening degree (PULn) + the following corrected valve solution degree (ΔPUL)), and a valve opening degree command signal corresponding thereto is output. Based on the output signal, the opening degree of the electronically controlled expansion valve 4 is adjusted. In block 716, the cycle stabilization time (Tb) is counted. If it is determined that the time Tb has not elapsed, the process returns to block 710. If it is determined that the time Tb has elapsed, the process proceeds to block 717. In block 717, a deviation amount (TD-TDn) between the current discharge temperature (TD) detected from the thermistor 8 and the set discharge temperature (TDn) is calculated, and a correction valve opening (ΔPUL) corresponding to the deviation is calculated, and the flow goes to block 710. Return.
[0029]
FIG. 10 is a detailed view of block 710. That is, when the temperature (TH8) of the thermistor 8 is not more than TDl, the valve opening command signal is not more than PULl and the operation frequency is not less than HZl, the maximum frequency is restricted to HZg. In other cases, there is no restriction.
[0030]
As described above, in the second embodiment of the present invention, when a failure occurs in the electronically controlled expansion valve, the compressor may be damaged due to the compressor liquid back operation depending on the position where the valve stops. It has succeeded in improving the reliability of the compressor by estimating the operating state of the compressor from the compressor frequency, valve opening and compressor discharge temperature, and regulating the maximum frequency of the compressor. .
[0031]
Note that such a state is not always a failure of the expansion valve, and may occur, for example, when the outside air temperature is very low. Therefore, without stopping the compressor, the compressor vanes jump, the amount of oil taken out from the compressor, the axial load of the compressor, etc. are dealt with by operating at a low speed rotation advantageous for the compressor. .
[0032]
Embodiment 3 of the Invention
FIG. 11 shows a configuration diagram of the third embodiment of the present invention. 1 is a compressor, 2 is an electric motor, 3 is an outdoor heat exchanger, 4 is an electronically controlled expansion valve, and 5 is an indoor heat exchanger. 6 is a frequency variable device, and 7 is a control device. The control device 7 includes a storage function, a calculation function, a control unit 71 that controls these functions, and a valve drive unit that operates the electronically controlled expansion valve 4 based on an output signal (valve opening command signal) of the control unit 71. 72.
[0033]
In the air conditioner using the refrigerant circuit configuration of the third embodiment of the present invention as described above, the refrigerant flow rate control is performed by the compressor 2 and the electronically controlled expansion valve 4, and therefore the electronically controlled expansion valve In the case of failure, the refrigerant flow rate cannot be controlled. However, it is necessary to confirm that the expansion valve is actually driven because the failure of the electronically controlled expansion valve cannot be accurately diagnosed only by the operating situation during service. Therefore, when the electronically controlled expansion valve is driven by being energized in the opening direction, the opening direction energization is performed as a failure diagnosis mode at the time of service using the click and clicking sound when fully opened. Make a decision. If there is a sound, the electronically controlled expansion is normal because it is driving, and if there is no sound, it is a failure.
[0034]
Next, an example of a mechanism that makes a sound when the electronically controlled expansion valve is fully opened will be described with reference to FIG. FIG. 12 is a cross-sectional view of an example of an electronically controlled expansion valve. The driving principle will be briefly explained. The portion shown in the figure is a stepping motor, and the rotor 11 rotates. The rotating operation is converted into a vertical motion by a screw, and the valve 12 is provided with an opening / closing motion. Yes. When the valve advances in the opening direction, the protrusion A13 attached to the rotor comes into contact with the protrusion B14 and makes a sound.
[0035]
As described above, in the third embodiment of the present invention, energization in the opening direction is performed at the time of service, and the sound generated when the electronically controlled expansion valve is fully opened can be confirmed, so that a reliable failure diagnosis can be performed.
[0036]
【The invention's effect】
The air conditioner according to claim 1, wherein the compressor, the two rows of indoor heat exchangers, the electronically controlled expansion valve, and the outdoor heat exchanger constitute a refrigeration cycle, and the two rows of indoor heat exchange during cooling operation. A refrigerant flow rate control means for controlling the amount of refrigerant is provided in the first row of the heat exchanger so that the superheated steam region does not go around , and the compressor is driven by an inverter. In the air conditioner, the two rows of indoor side heat exchangers at the time of the cooling operation are provided at the inlets in the refrigerant flow direction and at positions where the superheat degree is large and the superheated steam region is not circulated to the first row of the heat exchanger. When the temperature difference between the sensors exceeds a certain value, the refrigerant flow rate is increased, so that damp air can be sucked into the indoor unit casing and condensation can occur on the air passage walls, blowers, and wind direction change plates. Overheated steam in the inner heat exchanger The air region can be directly detected, and it is possible to reliably prevent the exposure and dripping, as well as to detect the danger of exposure and dripping and to avoid the danger.
[0038]
The air conditioner according to claim 2, wherein the compressor, the two rows of indoor heat exchangers, the electronically controlled expansion valve, and the outdoor heat exchanger form a refrigeration cycle, and the two rows of indoor heat during cooling operation. An inlet for the refrigerant flow direction of the exchanger, a superheat degree is large and a sensor for detecting the temperature of the refrigerant is provided at the position where the superheated steam area does not go around in the first row of the heat exchanger , and the compressor is driven by an inverter If the temperature difference of the sensor exceeds a certain value, the refrigerant flow rate is increased, so that the temperature difference between the inlet of the indoor heat exchanger and the sensor in the middle is dewed and dripped. Detecting and avoiding the danger of water, it has the effect of reducing the superheated steam area and preventing dew spilling and dripping.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an air conditioner showing Embodiment 1 of the invention.
FIG. 2 is an explanatory diagram of the relationship between frequency and capacity of an air conditioner showing Embodiment 1 and Embodiment 2 of the present invention.
FIG. 3 is an explanatory diagram of the relationship between the frequency of the air conditioner and the set optimum valve opening value according to the first and second embodiments of the present invention.
FIG. 4 is a diagram illustrating the relationship between the frequency of an air conditioner and a set discharge temperature according to Embodiment 1 and Embodiment 2 of the present invention.
FIG. 5 is a detailed view showing the positional relationship between an inlet thermistor and an intermediate thermistor according to Embodiment 1 of the present invention.
FIG. 6 is a control flowchart showing Embodiment 1 of the present invention.
FIG. 7 is a flowchart showing details of block 714 in FIG. 6;
FIG. 8 is a configuration diagram of an air conditioner showing Embodiment 2 of the present invention.
FIG. 9 is a control flowchart showing Embodiment 2 of the present invention.
FIG. 10 is a flowchart showing details of block 710 in FIG. 9;
FIG. 11 is a block diagram of an air conditioner showing Embodiment 3 of the present invention. FIG. 12 is a cross-sectional view of an electronically controlled expansion valve showing Embodiment 3 of the invention.
FIG. 13 is a configuration diagram of an air conditioner showing a conventional technique.
[Explanation of symbols]
1: compressor, 2: motor, 3: outdoor heat exchanger, 4: electronically controlled expansion valve, 5: indoor heat exchanger, 6: frequency variable device, 7: control device, 8: discharge temperature detection thermistor , 9: inlet temperature detection thermistor, 10: intermediate temperature detection thermistor,

Claims

圧縮機、２列パスパターンの室内側熱交換器、電子制御式膨張弁、室外側熱交換器で冷凍サイクルを成し、冷房運転時の前記２列の室内側熱交換器の冷媒の流れる方向の入口及び過熱度が大きくしかも前記熱交換器の１列目に過熱蒸気領域を回り込ませない位置に冷媒量を制御する冷媒流量制御手段を設け、圧縮機がインバータ駆動する空気調和機において、前記冷房運転時の２列パスパターンの室内側熱交換器の冷媒の流れる方向の入口及び過熱度が大きくしかも前記熱交換器の１列目に過熱蒸気領域を回り込ませない位置に設けたセンサーの温度差がある一定値を越えた場合冷媒流量を増やすことを特徴とする空気調和機。The refrigerant, the flow direction of the refrigerant in the two-row indoor heat exchanger during cooling operation, in which a refrigeration cycle is formed by the compressor, the two-row indoor pattern heat exchanger, the electronically controlled expansion valve, and the outdoor heat exchanger In the air conditioner in which the refrigerant flow control means for controlling the refrigerant amount is provided in a position where the superheated steam region is not circulated in the first row of the heat exchanger and the compressor is inverter-driven. The temperature of the sensor provided at the inlet of the indoor heat exchanger in the flow direction of the refrigerant in the two-row path pattern during cooling operation and at the position where the degree of superheat is large and the superheated steam region is not circulated in the first row of the heat exchanger An air conditioner characterized by increasing a refrigerant flow rate when a difference exceeds a certain value.

圧縮機、２列パスパターンの室内側熱交換器、電子制御式膨張弁、室外側熱交換器で冷凍サイクルを成し、冷房運転時の室内側熱交換器の冷媒の流れる方向の入口、過熱度が大きくしかも前記熱交換器の１列目に過熱蒸気領域を回り込ませない位置及び出口に冷媒の温度を検知するセンサーを設け、圧縮機がインバータ駆動する空気調和機であって、センサーの温度差がある一定値を越えた場合冷媒流量を増やすことを特徴とする空気調和機。A refrigeration cycle is formed by a compressor, a two-row indoor pattern heat exchanger, an electronically controlled expansion valve, and an outdoor heat exchanger, and an inlet in the direction of refrigerant flow in the indoor heat exchanger during cooling operation, overheating A sensor for detecting the temperature of the refrigerant is provided at the position where the superheated steam region does not go around and the outlet in the first row of the heat exchanger, and the compressor is an inverter-driven air conditioner, and the temperature of the sensor An air conditioner characterized by increasing a refrigerant flow rate when a difference exceeds a certain value.