【０００１】
【発明の属する技術分野】
本発明はヒートポンプ式給湯機に関するもので、特に高圧条件となるＣＯ２等の自然冷媒を使用する場合の水・冷媒熱交換器に関する。
【０００２】
【従来の技術】
従来の給湯機には、貯湯槽を持たずにガス等を燃焼させてその強力な燃焼熱で瞬間的に水を沸き上げて湯を供給する燃焼式給湯機、大容量の貯湯槽を持ち夜間割引の安い電力を利用することで夜の間に電気ヒーターで加熱した大量の湯を貯湯槽に貯蔵して日中にこの貯蔵した湯を使う電気温水器等が知られている。
【０００３】
しかし、最近ではこの電気温水器に比較してエネルギー効率が３００〜５００％も良いといわれるヒートポンプ式給湯機が普及し始めてきた。ヒートポンプ式給湯機は、熱源に冷媒の状態変化を利用しているので、電気ヒーター加熱の数倍エネルギー効率が良く、またガス等を燃焼しないので炭酸ガスを排出せず環境にやさしい給湯機といわれている。
【０００４】
しかし、ガス等を燃焼した時のような強力な熱量が無いため、電気温水器と同様に大容量の貯湯槽を設けることで夜間の安価な電力を使って、夜中にヒートポンプ回路で湯を沸き上げて貯湯槽に貯蔵し、日中は貯蔵した湯を使うという方法が一般的であった。
【０００５】
したがって、従来のヒートポンプ式給湯機ではヒートポンプ回路と、ヒートポンプ回路で沸かした湯を大量に貯蔵しておく貯湯槽をそれぞれ別個の装置として設け、配管等で接続して給湯機として機能させていた。
【０００６】
例えば、特開平９−１２６５４７号公報においては、圧縮機、凝縮器、減圧装置、蒸発器から構成されたヒートポンプ回路と、大容量の貯湯槽を別個の装置として設けていた。しかし、貯湯槽に貯蔵した湯で浴槽を満たすことを考えると、貯湯槽の容量は浴槽と同様２００Ｌ近くになり、洗面や台所使用との併用を考慮するとその質量は２００Ｋｇを超えることになってしまう。
【０００７】
従って、従来のヒートポンプ式給湯機は大きな設置スペースを必要とすると共に、貯湯槽の容量一杯に湯を貯めた場合を考えると、その質量は２００Ｋｇを超える重さとなるので、設置場所に関しては基礎工事を行なって地盤を堅固にしなければならない等、大掛かりな設備としなければならない。このため、アパートやマンションのベランダのような狭い場所や強度の不十分な場所には据え付けることができなかった。
【０００８】
また、従来のヒートポンプ式給湯機は夜間の安い電気料金を利用して、夜中にヒートポンプ回路を運転して高温の湯にして貯湯槽に貯え、日中はヒートポンプ回路を運転しないで貯湯槽に貯まっている湯を使用するという使い方をしているため、時には貯湯槽の湯を使いきってしまい、すぐに沸き上げることができず湯切れを起こすことがあった。また、外気温度より温度の高い大量の湯を貯蔵するため貯湯槽の表面から熱が放散されてエネルギーの無駄使いになり、それによって温度が下がる分、夜の間に余裕をもって温めておく必要があった。
【０００９】
上記大容量貯湯槽を備えたヒートポンプ給湯システムの問題点は、貯湯槽が大容量であるため、設置場所が限定される点である。この問題を解決するためには、大容量の貯湯槽に大量の湯を貯蔵することをやめ、圧縮機の運転制御にインバーター制御方式を取り入れて高速回転運転を行い、ヒートポンプ回路で沸き上げた温水を直接、使用端末に供給する方式、すなわちヒートポンプ式瞬間給湯機とする必要がある。
【００１０】
従来のヒートポンプに使用される冷媒の凝縮熱を水へ伝達するための水・冷媒熱交換器は、特開２００１−２４８９０４号公報に記載されているように、偏平状の給湯水管と冷媒管を交互に重ねてコイル状とする構造となっている。
【００１１】
【発明が解決しようとする課題】
ところで、近年、地球環境保護の観点から、冷媒としては地球温暖化係数の大きい従来のフロン系冷媒から温暖化係数の極めて小さい自然冷媒に移行する動きが活発になってきた。ＣＯ２等の自然冷媒をヒートポンプ式給湯機に採用すると、高温高圧冷媒であるので加熱能力の向上を図ることが可能である。
【００１２】
したがって、冷媒をより高温高圧となる自然系冷媒を使用すると共に、大容量の貯湯槽を排して小さな補助タンクに置き代え、ヒートポンプによる瞬間式給湯機の実現が可能となってきた。
【００１３】
しかし、この方式を実用化するには次のような問題点があった。即ち、自然系冷媒を使用し且つ圧縮機を高速運転するため、圧縮機で吐出される冷媒ガスの状態が従来冷媒の場合に比べ高温高圧になり、高圧側の冷媒回路が上記特開２００１−２４８９０４号公報に示されたものでは、単に同一系の冷媒管と流水管とを交互に積層しているため、強度上耐えられない。なお、高圧側冷媒回路のうち、接続用配管は単純にパイプの肉厚を増せば良いが、高圧側の水・冷媒熱交換器は高温冷媒と給水との熱交換を行なうため単純にパイプの肉厚を増すと、パイプの加工性が悪くなるため冷媒配管と水配管の接触部に隙間が生じ易くなる等の原因により伝熱性能が低下する恐れがあった。
【００１４】
また、大容量の貯湯槽をやめ、直接使用端末に湯を供給する方式にするためには、従来の貯湯槽循環用の配管に加え、直接湯を使用端末に送る配管が必要となる等、水熱交換器に２回路の水配管を通すこととなるので、全く新たな水・冷媒熱交換器を必要とする。
【００１５】
しかしながら、この水冷媒熱交換器は、ＣＯ２冷媒を想定してなく、瞬間式を想定していないため、高圧条件に耐えうるかどうか不明であり、さらに少なくとも２回路の水配管については配慮されていない。また、単に、偏平銅管を積み重ねた構造であるため、左右（地面水平方向）の安定性が悪く、コイル状水冷媒熱交換器の外周を覆う外枠、コイル状水冷媒熱交換器の積み重ね方向を圧接する支持板、ネジ棒及びナットといった多くの固定用付属部品を必要としていた。
【００１６】
本発明はこれらの課題を解決するためになされたもので、設置に必要なスペースや質量が小さく、地球環境にやさしい冷媒を使用したエネルギー効率の良いヒートポンプ式給湯機を提供するものである。
【００１７】
【課題を解決するための手段】
上記目的は、圧縮機、水・冷媒熱交換器、減圧装置、蒸発器を冷媒配管で順次接続してなるヒートポンプ回路を備えたヒートポンプ式給湯器において、前記水・冷媒熱交換器を、複数の貫通孔を有する冷媒管の両側面に流水管を平行に接合された構造とし、これら流水管の先端部を前記冷媒管から離れるように曲げることによって達成される。冷媒管を複数の貫通孔を有するものとしてこの冷媒管に流水管を接合したので、圧力が高い冷媒を使用してもこの圧力に耐えることができ、また冷媒管と流水管との接触面積が広くなるので伝熱効率が向上するので、瞬間式ヒートポンプ給湯機として十分機能し得る。
【００１８】
また、上記目的は、圧縮機、水・冷媒熱交換器、減圧装置、蒸発器を冷媒配管で順次接続してなるヒートポンプ回路を備えたヒートポンプ式給湯器において、前記水・冷媒熱交換器を、楕円状流水管の両側面に複数の冷媒管が接合された構造とし、これら冷媒管の先端部を前記流水管から一旦離れるように曲げ、さらに先端部で冷媒管同士を分岐部にて一本の冷媒管とする構造とすることによって達成される。楕円状流水管の両側面に複数の冷媒管が接合された構造としたことで、接触面積が増大するため伝熱効率が向上するため、瞬間式でも十分水温を上昇させることができる。
【００１９】
また、上記目的は、圧縮機、水・冷媒熱交換器、減圧装置、蒸発器を冷媒配管で順次接続してなるヒートポンプ回路を備えたヒートポンプ式給湯器において、前記水・冷媒熱交換器を、複数の細径流路を有する管路とした冷媒管と、偏平流路とした流水管とを有し、前記冷媒管に複数の前記流水管を密着させた構造とすることによって達成される。冷媒管を複数の細径流路を有する管路としたので圧力が高い冷媒を使用しても破損等の問題を低減でき、流水管との伝熱面積が増大したので瞬間式として十分水温の上昇を図ることができる。
【００２０】
また、圧縮機、水・冷媒熱交換器、減圧装置、蒸発器を冷媒配管で順次接続してなるヒートポンプ回路を備えたヒートポンプ式給湯器において、前記水・冷媒熱交換器を、冷媒管を２本の流水管が挟むように密着させ、内側及び外側が流水管となるようにコイル状に巻回することにより達成される。内側及び外側が流水管となるようにコイル状に巻回したので、冷媒管が空気に露出する部分を減らすことができるので、冷媒が保持している熱を水に伝熱させることができる。このため、瞬間式として十分水温を上昇させることができる。
【００２１】
【発明の実施の形態】
以下、本発明の実施例を図によって説明する。図１〜図６は本発明の水・冷媒熱交換器の実施例で、図７は上記水・冷媒熱交換器を用いた本発明のヒートポンプ式給湯機の冷媒配管回路及び水配管回路図の一実施例である。
【００２２】
以下、上記水・冷媒熱交換器１を用いたヒートポンプ式給湯機について説明する。図７は本発明のヒートポンプ式給湯機の冷媒循環回路２０及び水循環回路３０の一実施例を示す。２０は冷媒循環回路で圧縮機２１、水・冷媒熱交換器１、減圧装置２２、蒸発器２３及び受液器２４で構成され、上記それぞれの部品間は冷媒接続配管２５ａ〜２５ｅで接続され冷媒循環サイクルを形成している。また、２６はバイパス弁で圧縮機２１と水・冷媒熱交換器１間及び減圧装置２２と蒸発器２３間に接続されている。
【００２３】
上記冷媒循環回路２０の運転動作について説明する。ヒートポンプ回路が運転されると圧縮機２１が圧縮運転を開始し、ガス冷媒を圧縮し高温高圧ガスとして水・冷媒熱交換器１に送り込む。水・冷媒熱交換器１に送り込まれた冷媒は、詳細を後述する図１、図２に示すように冷媒配管５から分かれて複数の細い貫通孔２ａを流れ、流水管３、４の中空部３ａ、４ａを流れる循環水と熱交換して凝縮され、温度の幾分下がった凝縮冷媒となり冷媒配管６を通って減圧弁２２へ流れる。減圧弁２２で減圧された冷媒は蒸発器２３で蒸発して低温ガスとなり圧縮機２１に戻り再び圧縮を繰り返すものである。
【００２４】
なお、受液器２４は蒸発器２３で冷媒がガス化しきれず液冷媒が残った場合、液冷媒が圧縮機内に吸込まれて圧縮不良を起こさないよう液溜めの役目をするものである。また、バイパス弁２６は通常作動せず冷媒を通さないが、冬期の低温運転時に蒸発器２３に着霜した場合に作動して開弁し圧縮機２１で圧縮された高温冷媒を直接蒸発器２３へ送り込み霜を溶かしてヒートポンプ運転の性能低下を防止するものである。
【００２５】
次に、給湯回路について説明する。図７において水循環回路３０は、台所に湯又は水を供給する台所給湯回路と、風呂に水又は湯を供給する風呂給湯回路と、浴槽４２内の湯又は水を加熱する風呂追炊き回路とを備えている。
【００２６】
台所給湯回路は、給水源３１となる水道に直結して水圧や水量を調整する流量調整弁３７ａ、逆止弁３２ａ、水を加熱して温水にする水・冷媒熱交換器１、温水を貯蔵する補助タンク３３、水・冷媒熱交換器からの水温が低い場合に補助タンク３３からの湯を調整切換弁３５に流す又は水・冷媒熱交換器１からの湯水を調整切換弁３５に流す水切換弁３４、水循環回路の切換えと共に給水源３１からの水と水切換弁３４からの温水を混合して水温を必要温度に調節する調整切換弁３５及び台所蛇口３６より構成されている。なお、３７ｂは流量調整弁である。
【００２７】
また、風呂給湯回路は、流量調整弁３７ｂ以降の配管で台所給湯回路から分岐され、その先に風呂蛇口４５、シャワー４６、浴槽蛇口４０、及び流量調整弁３７ｃと逆止弁３２ｃを介して接続された風呂水出口４３とを備えている。
【００２８】
さらに、風呂追炊き回路は、風呂水入口４４、風呂水循環ポンプ４１、水・冷媒熱交換器１、及び風呂水出口を備えている。なお、４７は風呂排水口である。
【００２９】
台所給湯回路、風呂給湯回路のいずれかの栓が開かれて水が流れ給水源３１付近に設けられた水量計によって所定以上の流量が検出される、若しくは風呂追炊きポンプ４１が運転されるとヒートポンプ回路２０が動作し始める。ヒートポンプ回路２０が運転されると高温冷媒が水・冷媒熱交換器１に流入し、台所給湯回路や風呂給湯回路へと接続される接続配管７から流入する水又は風呂追炊き回路の接続配管９から流入する水若しくは両者を加熱し６０℃以上の温水として接続配管８及び接続配管１０へ送り出し始める。
【００３０】
補助タンク３３の貯湯運転について説明する。この貯湯運転は温水を使用していない時に行い、給水源３１からの水道圧により、給水源３１―流量調整弁３７ａ―逆止弁３２ａ―接続配管７―水・冷媒熱交換器１―接続配管８―水切換弁３４―補助タンク３３の貯湯回路にて補助タンク３３に温水を貯湯する。上記貯湯運転は自動的に行われ、通常補助タンク３３には温水が満たされた状態となっている。
【００３１】
次に、温水使用時の給湯回路について説明する。台所蛇口３６やシャワー４６などが開かれて出湯使用が始まると同時にヒートポンプ運転が開始される。しかし、運転開始直後の５〜６分間は水・冷媒熱交換器１が十分に温まっていないため加熱能力が充分ではない。このため、水切換弁３４は補助タンク３３と調整切換弁３５間のみ開とし、給水源３１からの水道圧により、給水源３１―温水の貯めてある補助タンク３３―水切換弁３４―調整切換弁３５―台所蛇口３６の給湯回路にて台所蛇口３６等より給湯する。
【００３２】
ヒートポンプ運転が５〜６分間経過し冷媒の凝縮熱が水を温水に加熱できる充分な熱量に達すると、切換弁３４は接続配管８と調整切換弁３５間側のみ開となり、給水源３１―逆止弁３２―接続配管７―水・冷媒熱交換器１―接続配管８―水切換弁３４―調整切換弁３５―台所蛇口３６等の給湯回路にて台所蛇口３６等より給湯する。即ち、給水開始時の５〜６分間のみ補助タンク３３より給水し、その後はヒートポンプ運転による加熱水を直接給湯するものである。
【００３３】
次に風呂給湯回路について説明する。浴槽４２に設けられた風呂蛇口４０を開くと風呂給湯が始まると同時にヒートポンプ運転が開始されるが、運転開始直後の５〜６分間は加熱能力が充分でないため、水切換弁３４は補助タンク３３と調整切換弁３５間のみ開とし、給水源３１からの水道圧により、給水源３１―温水の貯めてある補助タンク３３―水切換弁３４―調整切換弁（ミキシングバルブ）３５―流量調整弁３７ｂ―風呂蛇口４０の給湯回路にて風呂蛇口４０より浴槽に給湯する。また、風呂自動湯はり運転の場合、マイコンからの指令で流量調整弁３７ｃが開き、これと共にヒートポンプ運転が開始される。そして、浴槽給湯と同様、湯が風呂水出口４３から所定の湯量となるまで湯が出湯される。
【００３４】
ヒートポンプ運転が５〜６分間経過し冷媒の凝縮熱が水を温水に加熱できる充分な熱量に達すると、切換弁３４は接続配管８と調整切換弁３５間側のみ開となり、給水源３１―流量調整弁３７ａ―逆止弁３２ａ―接続配管７―水・冷媒熱交換器１―接続配管８―水切換弁３４―調整切換弁３５―風呂蛇口４０、または給水源３１―流量調整弁３７ａ―逆止弁３２ａ―接続配管７―水・冷媒熱交換器１―接続配管８―水切換弁３４―調整切換弁３５―水切換弁３７―逆止弁３８―風呂水出口の給湯回路にて浴槽に給湯する。
【００３５】
さらに、浴槽４２の湯温が下がった場合の追炊き回路について説明する。操作ボタンで追炊き指示をすると風呂水循環ポンプ４１が稼動し、風呂水入口４４―風呂水循環ポンプ４１―接続配管９―水・冷媒熱交換器１―接続配管１０―風呂水出口４３の給湯回路にて風呂水出口４４より温水となって浴槽に戻る。
【００３６】
一方、風呂の追い炊き回路を設けない簡易給湯機の場合は、風呂蛇口４０を台所蛇口３６と並列に設けることにより風呂水循環回路の流量調整弁３７ａ、風呂水循環ポンプ４１、接続配管９、１０を省略できる。そして、水・冷媒熱交換器５１の構造を後述する図８に示すように簡略化することができる。
【００３７】
尚、本ヒートポンプ式給湯機は電子制御回路（図示せず）を有しており、冷媒循環回路２０及び水循環回路３０の必要な各部に温度検知用サーミスタや圧力スイッチ、水量計等が設置されており、各種切換弁や風呂水循環ポンプ４１等を制御しているものである。
【００３８】
また、実施例では図示しないが台所蛇口３６と平行して洗面所蛇口を設けること等の応用も可能である。
【００３９】
次に、上記水・冷媒熱交換機について図１〜図６を用いて、その構造を説明する。図１は本実施例の水・冷媒熱交換器１の円筒状成形加工前の冷媒管２と流水管３、４の接合状態を示すもので図の右側は中心断面状態を示す。
【００４０】
冷媒管２は図１のＡＡ断面として図２に示すように複数の細い貫通孔２ａを有する金属成形品である。３は台所水循環用流水管、４は風呂水循環用（追炊き用）流水管で、いずれも図２に示すように水が流れる中空部３ａ、４ａを有する偏平状銅管を用い冷媒管２の両側面に平行に接合して一体形配管されている。そして、各流水管３、４の両端部３ｂ、４ｂは、図１に示す如く冷媒管２を中心として相反する方向に曲げられ接続配管７、８、９、１０とロー付け接続する。なお、冷媒管２は両端を曲げることなく冷媒配管５、６とロー付け接続している。
【００４１】
上記冷媒管２、流水管３、４の一体形配管は、図４、図５に示す如く円筒状で且つ巻き段部３Ｃに隙間が生じないよう、円筒の内側及び外側が流水管（冷媒管２が内壁及び外壁から露出しない）となるように密着して巻き上げられる。さらに、各管の先端部を延長して接続部２ｄ、３ｄ、４ｄを円筒状の外側に配置して水・冷媒熱交換器１とするものである。これによって、配管の接続作業性を向上させることができる。
【００４２】
なお、給湯機本体が長方形で長方形スペースが有る場合には水・冷媒熱交換器１の冷媒管２、台所水循環用流水管３、風呂水循環用流水管４の一体品を図６の如く楕円形に成形することも有効である。
【００４３】
また、流水管３、４の外形、中空部３ａ、４ａの形状を共に図２の如く楕円形にすることにより冷媒管２との接触面積が大きく取れ、且つ図４の成形加工が容易になる。
【００４４】
以上により、冷媒管２が高圧に耐えることができるようになり、従来のように給湯水管１０２と冷媒管１０３がほぼ同一径であるためＣＯ２等の自然系冷媒の高圧に耐えられず、Ｒ２２等従来のフロン系冷媒にしか適用できなかった水・冷媒熱交換器と比べて、ＣＯ２等の自然系冷媒を用いることができるようになった。
【００４５】
ところで、大容量給湯機の場合で、冷媒管２が長すぎて金属成形が難しい場合や冷媒管２の貫通孔２ａが太く金属成形の冷媒管２の剛性が強く図４、図６に示す成形加工が困難な場合が考えられる。この場合には、図３に示すように金属成形品の代りに、細径孔１１ａを有する細銅管のキャピラリチューブ１１を複数本並べて流水管３、４に接合して使用する。これにより成形加工性が向上し、熱伝導性はやや落ちるものの大容量の給湯機では影響が少ない。
【００４６】
次に、風呂追炊き回路を設けない簡易給湯器の水・冷媒熱交換器について図８を用いて説明する。冷媒接続配管５及び６間を複数の細い貫通孔を有する２本の冷媒管５２、５３に分岐させ、水の接続配管７及び８間に接続された流水管５４を中心とし両側面に冷媒管５２、５３を接合した。これにより、冷媒から循環水への電熱効率をより一層向上させることができる。
【００４７】
以上、本実施例によれば、ヒートポンプ式給湯機、特にＣＯ２等の自然冷媒を使用した高温高圧仕様に適応したヒートポンプ式給湯器の水・冷媒熱交換器を提供することができる。
【００４８】
即ち、図１、図５で説明した如く、圧縮機２１、水・冷媒熱交換器１、減圧装置２２、蒸発器２３を冷媒配管２５ａ〜２５ｅで順次接続してなるヒートポンプ回路において、複数の貫通孔２ａを有する冷媒管２の両側面に流水管３、４を平行に接合すると共に、流水管３、４の先端部を曲げた構造の水・冷媒熱交換器１としたものである。これにより、水・冷媒熱交換器１は冷媒管２と流水管３、４のみで構成され取付板等の部品を省略できると共に、加締めやロー付けによる接続シール部が少なく、冷媒管２の両側が流水管に接合されているため耐圧強度の信頼性向上が図れ、且つ流水管への熱伝導が均一で熱交換性能の向上や省スペース化等のメリットを有する水・冷媒熱交換器１を安価に提供し得るものである。
【００４９】
また、前記の水・冷媒熱交換器１と共に冷媒としてＣＯ２等の自然系冷媒を使用し、圧縮機運転用インバーター制御を設けることにより、大容量の貯湯槽を不要とした瞬間式ヒートポンプ式給湯機を提供し得るものである。
【００５０】
また、図２で説明した如く、水・冷媒熱交換器１の冷媒管２として複数の貫通孔２ａを有する金属成形品を使用することにより、冷媒の流れを細径に分岐させて耐圧強度をアップさせると共に、冷媒管２と流水管３、４との熱伝達面積を大きく取れ熱交換性能の良い水・冷媒熱交換器１を容易に提供し得る。
【００５１】
また、図３にて説明した如く、水・冷媒熱交換器１の冷媒管２として複数のキャピラリチューブを並列に配列して流水管１、４に接合した構造とすることにより、製品仕様として冷媒管２が長すぎて金属成形加工が難しい場合や図４、図６の成形加工が難しい場合に有効である。
【００５２】
また、図２、図３にて図示説明の如く、水・冷媒熱交換器１の流水管３、４として偏平状銅管を使用することにより円筒状への成形加工性が良く、且つ冷媒管２との伝熱面積を大きくできて熱交換性能の向上が図れる。
【００５３】
更に、水・冷媒熱交換器１の流水管３、４と冷媒管２の接合品を図４に示す如く、円筒状に巻くと共に流水管３、４及び冷媒管２の先端部を曲げて延長し、各配管５、７、９との接続部を上記円筒状の外側に設けることによりロー付け作業が容易にでき、各配管の曲げＲを大きく取れる等の効果と共に、補助タンク等の円筒部に巻き付けることによりスペースの有効利用や作業性の向上が図れる。
【００５４】
また、水・冷媒熱交換器１の流水管３、４と冷媒管２の接合品を図６に示す如く楕円形に巻くことにより、給湯機本体が長方形の場合に長方形スペースに合った水・冷媒熱交換器１形状とすることが出来る。
【００５５】
また、図８にて説明した如く、水・冷媒熱交換器５１の構造として楕円状流水管５４の両側面に複数の冷媒管５１、５３を接合することにより、水加熱回路が１回路で済む簡易型給湯機に適した水・冷媒熱交換器５１を提供できる。
【００５６】
【発明の効果】
以上本発明によれば、設置に必要なスペースや質量が小さく、地球環境にやさしい冷媒を使用したエネルギー効率の良いヒートポンプ式給湯機を提供することができる。
【図面の簡単な説明】
【図１】本発明のヒートポンプ式給湯機用水・冷媒熱交換器の一実施例を示す図。
【図２】図１に示す水・冷媒熱交換器のＡＡ断面図。
【図３】本発明の水・冷媒熱交換器に使用する冷媒管の別の実施例を示す図。
【図４】本発明の水・冷媒熱交換器の成形後の上面図。
【図５】図４に示す水・冷媒熱交換器の成形後の側面図。
【図６】本発明の水・冷媒熱交換器の成形形状を示す別の実施例を示す図。
【図７】本発明のヒートポンプ式給湯機の冷媒回路及び水循環回路を示す図。
【図８】本発明の水・冷媒熱交換器の構造を示す別の実施例を示す図。
【符号の説明】
１…水・冷媒熱交換器、２…冷媒管、２ａ…貫通孔、３…台所水循環用流水管、３ａ，４ａ…中空部、３ｂ，４ｂ…端部、３ｃ…巻き段部、４…風呂水循環用流水管５，６…冷媒配管、７，８…台所水循環用接続配管、９，１０…風呂水循環用接続配管、１１…キャピラリチューブ、１１ａ…細径孔、２０…冷媒循環回路、２１…圧縮機、２２…減圧装置、２３…蒸発器、２４…受液器、２５ａ〜２５ｅ…冷媒接続配管、２６…バイパス弁、３０…水循環回路、３１…給水源、３２ａ，３２ｂ，３２ｃ…逆止弁、３３…補助タンク、３４…水切換弁、３５…調整切換弁、３６台所蛇口、３７ａ，３７ｂ，３７ｃ…流量調整弁、４０…風呂蛇口、４１…風呂水循環ポンプ、４２…浴槽、４３…風呂水出口、４４…風呂水入口、５１…水・冷媒熱交換器、５２，５３…冷媒管、５４…流水管。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heat pump type water heater, and more particularly to a water / refrigerant heat exchanger in the case of using a natural refrigerant such as CO2 under high pressure conditions.
[0002]
[Prior art]
Conventional hot water heaters have a combustion type hot water heater that burns gas, etc. without having a hot water tank and instantly boil water with the strong combustion heat to supply hot water, and has a large capacity hot water tank at night. There is known an electric water heater or the like which stores a large amount of hot water heated by an electric heater during the night by using cheap electric power in a hot water storage tank and uses the stored hot water during the day.
[0003]
However, recently, heat pump water heaters, which are said to have an energy efficiency of 300 to 500% better than this electric water heater, have begun to spread. Heat pump water heaters use the state change of refrigerant as a heat source, so they are several times more energy efficient than electric heater heating, and do not burn gas etc., so they are said to be environmentally friendly water heaters that do not emit carbon dioxide gas. ing.
[0004]
However, since there is no strong heat as when burning gas, etc., a large-capacity hot water tank is provided like an electric water heater to use cheap electric power at night and boil water with a heat pump circuit at night. It was common practice to raise the water and store it in a hot water tank, and use the stored hot water during the day.
[0005]
Therefore, in a conventional heat pump water heater, a heat pump circuit and a hot water storage tank for storing a large amount of hot water boiled by the heat pump circuit are provided as separate devices, respectively, and connected by piping or the like to function as a water heater.
[0006]
For example, in Japanese Patent Application Laid-Open No. 9-126547, a heat pump circuit including a compressor, a condenser, a decompression device, and an evaporator, and a large-capacity hot water tank are provided as separate devices. However, considering that the bath tub is filled with hot water stored in the hot tub, the capacity of the hot tub becomes close to 200 L as in the case of the bath tub. I will.
[0007]
Therefore, the conventional heat pump water heater requires a large installation space, and when the hot water tank is filled with hot water, the weight of the heat pump water heater exceeds 200 kg. Large-scale facilities, such as the need to make the ground solid. For this reason, it could not be installed in a narrow place such as a veranda of an apartment or a condominium or a place with insufficient strength.
[0008]
In addition, conventional heat pump water heaters use low electricity rates at night, operate the heat pump circuit at night to make hot water and store it in a hot water tank, and store it in the hot water tank during the day without operating the heat pump circuit. Because they use hot water, they sometimes run out of hot water in the hot water tank, so they could not be boiled immediately and run out of water. In addition, since a large amount of hot water that has a higher temperature than the outside air temperature is stored, heat is dissipated from the surface of the hot water storage tank, resulting in waste of energy. there were.
[0009]
The problem with the heat pump hot water supply system including the large capacity hot water storage tank is that the hot water storage tank has a large capacity, and thus the installation location is limited. To solve this problem, we stopped storing a large amount of hot water in a large-capacity hot water tank, adopted an inverter control method in the operation control of the compressor, performed high-speed rotation operation, and heated the hot water pumped by the heat pump circuit. Needs to be directly supplied to the terminal used, that is, a heat pump type instantaneous water heater.
[0010]
The water / refrigerant heat exchanger for transferring the condensation heat of the refrigerant used in the conventional heat pump to water, as described in JP-A-2001-248904, includes a flat hot water supply pipe and a refrigerant pipe. It has a structure in which it is alternately stacked to form a coil.
[0011]
[Problems to be solved by the invention]
By the way, in recent years, from the viewpoint of protection of the global environment, there has been an active movement to switch from a conventional CFC-based refrigerant having a large global warming potential to a natural refrigerant having an extremely low global warming potential. When a natural refrigerant such as CO2 is used in a heat pump water heater, it is a high-temperature and high-pressure refrigerant, so that the heating capacity can be improved.
[0012]
Therefore, it has become possible to use an instantaneous water heater using a heat pump by using a natural refrigerant having a higher temperature and a higher pressure as a refrigerant, replacing a large capacity hot water storage tank with a small auxiliary tank.
[0013]
However, there are the following problems in putting this method into practical use. That is, since a natural refrigerant is used and the compressor is operated at a high speed, the state of the refrigerant gas discharged from the compressor becomes higher in temperature and pressure as compared with the case of the conventional refrigerant, and the refrigerant circuit on the high pressure side is described in Japanese Patent Laid-Open Publication No. In the structure disclosed in Japanese Patent No. 248904, since the refrigerant pipes and the flowing water pipes of the same system are simply laminated alternately, they cannot withstand strength. In the high-pressure side refrigerant circuit, the connecting pipe may simply increase the wall thickness of the pipe, but the high-pressure side water-refrigerant heat exchanger simply exchanges heat between the high-temperature refrigerant and the feedwater. When the wall thickness is increased, the workability of the pipe is deteriorated, so that a heat transfer performance may be deteriorated due to the fact that a gap is easily generated in a contact portion between the refrigerant pipe and the water pipe.
[0014]
In addition, in order to stop the large-capacity hot water tank and to supply hot water directly to the terminal used, in addition to the conventional piping for circulation of the hot water tank, a pipe for directly sending hot water to the terminal used is required, Since two circuits of water pipes are passed through the water heat exchanger, a completely new water / refrigerant heat exchanger is required.
[0015]
However, since this water-refrigerant heat exchanger does not assume a CO2 refrigerant and does not assume an instantaneous type, it is unclear whether it can withstand high-pressure conditions, and further, no consideration is given to at least two circuits of water piping. . In addition, since the structure is simply a stack of flat copper tubes, the left and right (horizontal ground direction) stability is poor, and an outer frame covering the outer periphery of the coiled water-refrigerant heat exchanger and the coiled water-refrigerant heat exchanger are stacked. Many fixing accessories such as supporting plates, screw rods and nuts for pressing the directions were required.
[0016]
The present invention has been made in order to solve these problems, and provides a heat pump type water heater that requires only a small space and mass for installation and has high energy efficiency using a refrigerant that is friendly to the global environment.
[0017]
[Means for Solving the Problems]
The object is to provide a heat pump type water heater equipped with a heat pump circuit in which a compressor, a water / refrigerant heat exchanger, a decompression device, and an evaporator are sequentially connected by a refrigerant pipe. This is achieved by forming a structure in which flowing water pipes are joined in parallel to both side surfaces of a refrigerant pipe having a through hole, and bending the distal ends of these flowing water pipes away from the refrigerant pipe. Since the coolant pipe has a plurality of through holes and the water pipe is joined to the coolant pipe, it can withstand this pressure even when a high-pressure refrigerant is used, and the contact area between the coolant pipe and the water pipe is reduced. Since the heat transfer efficiency is improved due to the expansion, it can function sufficiently as an instantaneous heat pump water heater.
[0018]
Further, the object is to provide a heat pump type water heater provided with a heat pump circuit in which a compressor, a water / refrigerant heat exchanger, a decompression device, and an evaporator are sequentially connected by a refrigerant pipe. A structure in which a plurality of refrigerant pipes are joined to both sides of the elliptical running water pipe is formed, and the distal ends of these refrigerant pipes are bent so as to be once away from the flowing water pipe, and the refrigerant pipes are further joined at the distal end by a single branch. This is achieved by adopting a structure in which a refrigerant pipe is used. With the structure in which a plurality of refrigerant pipes are joined to both side surfaces of the elliptical flowing water pipe, the contact area is increased and the heat transfer efficiency is improved, so that the water temperature can be sufficiently raised even in an instantaneous manner.
[0019]
Further, the object is to provide a heat pump type water heater provided with a heat pump circuit in which a compressor, a water / refrigerant heat exchanger, a decompression device, and an evaporator are sequentially connected by a refrigerant pipe. This is achieved by a structure having a refrigerant pipe as a conduit having a plurality of small-diameter flow paths and a flowing water pipe as a flat flow path, wherein the plurality of the flowing water pipes are brought into close contact with the refrigerant pipe. The refrigerant pipe is a conduit with a plurality of small-diameter channels, so even if a high-pressure refrigerant is used, problems such as breakage can be reduced, and the heat transfer area with the flowing water pipe has increased, so that the water temperature rises sufficiently as an instantaneous type. Can be achieved.
[0020]
Further, in a heat pump water heater provided with a heat pump circuit in which a compressor, a water / refrigerant heat exchanger, a pressure reducing device, and an evaporator are sequentially connected by a refrigerant pipe, the water / refrigerant heat exchanger is connected to a refrigerant pipe by two. This is achieved by bringing the two water pipes into close contact with each other so as to sandwich them, and winding them in a coil shape so that the inside and the outside become the water pipes. Since the inner and outer sides are wound in a coil shape so as to form a water pipe, the portion of the refrigerant pipe exposed to the air can be reduced, so that the heat retained by the refrigerant can be transferred to the water. Therefore, the water temperature can be sufficiently raised as an instantaneous expression.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 6 show an embodiment of the water / refrigerant heat exchanger of the present invention. FIG. 7 shows a refrigerant pipe circuit and a water pipe circuit diagram of a heat pump water heater of the present invention using the water / refrigerant heat exchanger. This is one embodiment.
[0022]
Hereinafter, a heat pump water heater using the water / refrigerant heat exchanger 1 will be described. FIG. 7 shows an embodiment of the refrigerant circuit 20 and the water circuit 30 of the heat pump water heater according to the present invention. Reference numeral 20 denotes a refrigerant circulation circuit, which includes a compressor 21, a water / refrigerant heat exchanger 1, a decompression device 22, an evaporator 23, and a liquid receiver 24. The above-mentioned components are connected by refrigerant connection pipes 25a to 25e and connected to a refrigerant. Forming a circulation cycle. A bypass valve 26 is connected between the compressor 21 and the water / refrigerant heat exchanger 1 and between the pressure reducing device 22 and the evaporator 23.
[0023]
The operation of the refrigerant circuit 20 will be described. When the heat pump circuit is operated, the compressor 21 starts the compression operation, compresses the gas refrigerant and sends it to the water / refrigerant heat exchanger 1 as a high-temperature high-pressure gas. The refrigerant sent into the water / refrigerant heat exchanger 1 is separated from the refrigerant pipe 5 and flows through a plurality of narrow through holes 2a as shown in FIGS. The refrigerant exchanges heat with the circulating water flowing through 3a and 4a, is condensed, and becomes a condensed refrigerant whose temperature is somewhat lowered, and flows to the pressure reducing valve 22 through the refrigerant pipe 6. The refrigerant decompressed by the pressure reducing valve 22 evaporates in the evaporator 23 to become a low-temperature gas, returns to the compressor 21, and repeats compression again.
[0024]
The liquid receiver 24 serves as a liquid reservoir so that when the refrigerant cannot be completely gasified in the evaporator 23 and the liquid refrigerant remains, the liquid refrigerant is not sucked into the compressor to cause compression failure. The bypass valve 26 does not normally operate and does not allow the passage of the refrigerant. However, when the frost is formed on the evaporator 23 during the low-temperature operation in winter, the bypass valve 26 is opened to open the valve and directly discharge the high-temperature refrigerant compressed by the compressor 21 to the evaporator 23. And melts the frost to prevent the performance of the heat pump from deteriorating.
[0025]
Next, the hot water supply circuit will be described. In FIG. 7, the water circulation circuit 30 includes a kitchen hot water supply circuit for supplying hot water or water to the kitchen, a bath hot water supply circuit for supplying water or hot water to the bath, and a bath reheating circuit for heating the hot water or water in the bathtub 42. Have.
[0026]
The kitchen hot water supply circuit is directly connected to a water supply serving as a water supply source 31, and controls a water pressure and a flow rate, and a flow control valve 37a, a check valve 32a, a water / refrigerant heat exchanger 1 for heating water to make hot water, and storing hot water. When the water temperature from the auxiliary tank 33 and the water / refrigerant heat exchanger is low, the hot water from the auxiliary tank 33 flows to the adjustment switching valve 35, or the hot water from the water / refrigerant heat exchanger 1 flows to the adjustment switching valve 35. It is composed of a switching valve 34, an adjustment switching valve 35 for mixing water from the water supply source 31 and hot water from the water switching valve 34 together with switching of the water circulation circuit to adjust the water temperature to a required temperature, and a kitchen faucet 36. 37b is a flow control valve.
[0027]
The bath hot water supply circuit is branched from the kitchen hot water supply circuit by piping after the flow control valve 37b, and is connected to the bath tap 45, the shower 46, the bathtub tap 40, and the flow control valve 37c via the check valve 32c. Bath water outlet 43 provided.
[0028]
Further, the bath additional cooking circuit includes a bath water inlet 44, a bath water circulation pump 41, a water / refrigerant heat exchanger 1, and a bath water outlet. In addition, 47 is a bath drain port.
[0029]
When any one of the kitchen hot water supply circuit and the bath hot water supply circuit is opened and water flows and a flow rate of a predetermined value or more is detected by a water meter provided near the water supply source 31, or the bath additional heating pump 41 is operated. The heat pump circuit 20 starts operating. When the heat pump circuit 20 is operated, the high-temperature refrigerant flows into the water / refrigerant heat exchanger 1, and the connection pipe 9 of the water or bath additional cooking circuit that flows from the connection pipe 7 connected to the kitchen hot water supply circuit or the bath hot water supply circuit. And the water flowing in from both of them is heated and sent out to the connection pipe 8 and the connection pipe 10 as hot water of 60 ° C. or more.
[0030]
The hot water storage operation of the auxiliary tank 33 will be described. This hot water storage operation is performed when hot water is not used, and the water supply source 31-flow rate regulating valve 37a-check valve 32a-connection pipe 7-water / refrigerant heat exchanger 1-connection pipe by the water pressure from the water supply source 31 8-Water switching valve 34 —Hot water is stored in the auxiliary tank 33 in the hot water storage circuit of the auxiliary tank 33. The hot water storage operation is automatically performed, and the auxiliary tank 33 is normally in a state of being filled with hot water.
[0031]
Next, a hot water supply circuit when using hot water will be described. At the same time as the kitchen faucet 36 and the shower 46 are opened to start using hot water, the heat pump operation is started. However, the heating capacity is not sufficient because the water / refrigerant heat exchanger 1 is not sufficiently warmed for 5 to 6 minutes immediately after the start of operation. For this reason, the water switching valve 34 is opened only between the auxiliary tank 33 and the adjustment switching valve 35, and the water pressure from the water supply source 31 causes the water supply source 31 -the auxiliary tank 33 storing hot water-the water switching valve 34 -the adjustment switching. Valve 35-hot water is supplied from the kitchen faucet 36 or the like in the hot water supply circuit of the kitchen faucet 36.
[0032]
When the heat pump operation has elapsed for 5 to 6 minutes and the heat of condensation of the refrigerant has reached a sufficient amount of heat capable of heating water to hot water, the switching valve 34 is opened only between the connection pipe 8 and the adjustment switching valve 35, and the water supply source 31-reverse Hot water is supplied from the kitchen faucet 36 or the like in a hot water supply circuit such as the stop valve 32-the connection pipe 7-the water / refrigerant heat exchanger 1-the connection pipe 8-the water switching valve 34-the adjustment switching valve 35-the kitchen faucet 36. That is, the water is supplied from the auxiliary tank 33 only for 5 to 6 minutes at the start of water supply, and thereafter, the heated water by the heat pump operation is directly supplied.
[0033]
Next, the bath hot water supply circuit will be described. When the bath faucet 40 provided in the bathtub 42 is opened, the heat pump operation is started at the same time as the bath water supply is started. However, since the heating capacity is not sufficient for 5 to 6 minutes immediately after the start of the operation, the water switching valve 34 is connected to the auxiliary tank 33. And the adjustment switching valve 35 is opened only, and the tap water pressure from the water supply source 31 causes the water supply source 31-the auxiliary tank 33 storing hot water-the water switching valve 34-the adjustment switching valve (mixing valve) 35-the flow control valve 37b. -In the hot water supply circuit of the bath faucet 40, hot water is supplied to the bathtub from the bath faucet 40. Further, in the case of the bath automatic hot water operation, the flow control valve 37c is opened by a command from the microcomputer, and the heat pump operation is started at the same time. Then, similarly to the bathtub hot water supply, hot water is supplied from the bath water outlet 43 until a predetermined amount of hot water is supplied.
[0034]
When the heat pump operation has elapsed for 5 to 6 minutes and the heat of condensation of the refrigerant has reached a sufficient amount of heat capable of heating water to warm water, the switching valve 34 is opened only between the connection pipe 8 and the adjustment switching valve 35, and the water supply source 31-flow rate Regulating valve 37a-check valve 32a-connecting pipe 7-water / refrigerant heat exchanger 1-connecting pipe 8-water switching valve 34-regulating switching valve 35-bath faucet 40 or water supply source 31-flow regulating valve 37a-reverse Stop valve 32a-Connection pipe 7-Water / refrigerant heat exchanger 1-Connection pipe 8-Water switching valve 34-Adjustment switching valve 35-Water switching valve 37-Check valve 38-To the bathtub in the hot water supply circuit at the bath water outlet Hot water.
[0035]
Further, an additional cooking circuit when the temperature of the hot water in the bathtub 42 is lowered will be described. When an additional cooking instruction is given by the operation button, the bath water circulation pump 41 is operated, and the bath water inlet 44-bath water circulation pump 41-connection pipe 9-water / refrigerant heat exchanger 1-connection pipe 10-bath water outlet 43 is supplied to the hot water supply circuit. The hot water is returned from the bath water outlet 44 to the bathtub.
[0036]
On the other hand, in the case of a simple water heater having no bath reheating circuit, a bath tap 40 is provided in parallel with the kitchen tap 36 so that the flow control valve 37a of the bath water circulation circuit, the bath water circulation pump 41, and the connection pipes 9, 10 are connected. Can be omitted. And the structure of the water / refrigerant heat exchanger 51 can be simplified as shown in FIG. 8 described later.
[0037]
The heat pump type water heater has an electronic control circuit (not shown), and a temperature detecting thermistor, a pressure switch, a water meter, and the like are installed in necessary portions of the refrigerant circuit 20 and the water circuit 30. It controls various switching valves, the bath water circulation pump 41 and the like.
[0038]
Although not shown in the embodiment, an application such as providing a lavatory faucet in parallel with the kitchen faucet 36 is also possible.
[0039]
Next, the structure of the water / refrigerant heat exchanger will be described with reference to FIGS. FIG. 1 shows a joined state of the refrigerant pipe 2 and the flowing water pipes 3 and 4 of the water / refrigerant heat exchanger 1 of the present embodiment before the cylindrical forming process.
[0040]
The refrigerant pipe 2 is a metal molded product having a plurality of narrow through holes 2a as shown in FIG. 2 as an AA section in FIG. Numeral 3 denotes a water pipe for circulating kitchen water, and 4 denotes a water pipe for circulating bath water (for additional cooking), each of which is a flat copper pipe having hollow portions 3a and 4a through which water flows as shown in FIG. It is joined in parallel to both side surfaces and integrated piping. Then, both ends 3b, 4b of each of the flowing water pipes 3, 4 are bent in opposite directions about the refrigerant pipe 2 as shown in FIG. 1 and are connected to the connection pipes 7, 8, 9, 10 by brazing. The refrigerant pipe 2 is brazed to the refrigerant pipes 5 and 6 without bending both ends.
[0041]
As shown in FIGS. 4 and 5, the integral pipe of the refrigerant pipe 2 and the water pipes 3 and 4 has a cylindrical shape as shown in FIGS. 2 is not exposed from the inner wall and the outer wall). Furthermore, the water / refrigerant heat exchanger 1 is obtained by extending the distal end of each pipe and arranging the connecting portions 2d, 3d, 4d outside the cylindrical shape. Thereby, the connection workability of the piping can be improved.
[0042]
When the water heater main body is rectangular and has a rectangular space, an integrated product of the refrigerant pipe 2, the kitchen water circulation water pipe 3, and the bath water circulation water pipe 4 of the water / refrigerant heat exchanger 1 is formed into an elliptical shape as shown in FIG. Is also effective.
[0043]
Further, by making the outer shapes of the water pipes 3 and 4 and the shapes of the hollow portions 3a and 4a elliptical as shown in FIG. 2, a large contact area with the refrigerant pipe 2 can be obtained, and the molding process of FIG. .
[0044]
As described above, the refrigerant pipe 2 can withstand high pressure, and since the hot water pipe 102 and the refrigerant pipe 103 have substantially the same diameter as in the related art, the refrigerant pipe 2 cannot withstand the high pressure of natural refrigerant such as CO2. Compared with a conventional water / refrigerant heat exchanger that can only be applied to a CFC-based refrigerant, a natural refrigerant such as CO2 can be used.
[0045]
By the way, in the case of a large-capacity water heater, when the refrigerant pipe 2 is too long and metal forming is difficult, or when the through-hole 2a of the refrigerant pipe 2 is thick and the rigidity of the metal-formed refrigerant pipe 2 is high, the forming shown in FIGS. Processing may be difficult. In this case, as shown in FIG. 3, instead of a metal molded product, a plurality of capillary tubes 11 of a small copper tube having a small diameter hole 11a are arranged side by side and joined to the flowing water pipes 3, 4. As a result, the moldability is improved, and the heat conductivity is slightly reduced, but the effect is small in a large-capacity water heater.
[0046]
Next, a water / refrigerant heat exchanger of a simple water heater without a bath reheating circuit will be described with reference to FIG. The refrigerant connection pipes 5 and 6 are branched into two refrigerant pipes 52 and 53 each having a plurality of thin through holes, and refrigerant pipes are provided on both sides around a flowing water pipe 54 connected between the water connection pipes 7 and 8. 52 and 53 were joined. Thereby, the electric heating efficiency from the refrigerant to the circulating water can be further improved.
[0047]
As described above, according to this embodiment, it is possible to provide a water / refrigerant heat exchanger of a heat pump water heater, particularly a heat pump water heater adapted to a high-temperature and high-pressure specification using a natural refrigerant such as CO2.
[0048]
That is, as described with reference to FIGS. 1 and 5, in the heat pump circuit in which the compressor 21, the water / refrigerant heat exchanger 1, the pressure reducing device 22, and the evaporator 23 are sequentially connected by the refrigerant pipes 25 a to 25 e, A water / refrigerant heat exchanger 1 has a structure in which running water pipes 3 and 4 are joined in parallel to both side surfaces of a cooling pipe 2 having holes 2a, and the ends of the running water pipes 3 and 4 are bent. Thereby, the water / refrigerant heat exchanger 1 is composed of only the refrigerant pipe 2 and the flowing water pipes 3 and 4, and can omit components such as a mounting plate, and has few connection seal portions by caulking or brazing. A water / refrigerant heat exchanger 1 that has improved merits such as improved reliability of pressure resistance, uniform heat conduction to the water pipe, and improved heat exchange performance and space saving because both sides are joined to the water pipe. Can be provided at a low cost.
[0049]
Also, by using a natural refrigerant such as CO2 as a refrigerant together with the water / refrigerant heat exchanger 1 and providing an inverter control for compressor operation, an instantaneous heat pump water heater that does not require a large-capacity hot water storage tank is required. Can be provided.
[0050]
Further, as described with reference to FIG. 2, by using a metal molded product having a plurality of through holes 2 a as the refrigerant pipe 2 of the water / refrigerant heat exchanger 1, the flow of the refrigerant is branched into a small diameter to increase the pressure resistance. In addition to increasing the heat transfer area between the refrigerant pipe 2 and the flowing water pipes 3 and 4, the water / refrigerant heat exchanger 1 having good heat exchange performance can be easily provided.
[0051]
Further, as described with reference to FIG. 3, a plurality of capillary tubes are arranged in parallel as the refrigerant tube 2 of the water / refrigerant heat exchanger 1 and joined to the flowing water tubes 1 and 4, so that the refrigerant as a product specification can be obtained. This is effective when the metal forming process is difficult because the pipe 2 is too long, or when the forming processes in FIGS. 4 and 6 are difficult.
[0052]
As shown in FIGS. 2 and 3, the use of flat copper pipes as the water pipes 3 and 4 of the water / refrigerant heat exchanger 1 improves the processability into a cylindrical shape, and also provides a refrigerant pipe. 2, the heat transfer area can be increased, and the heat exchange performance can be improved.
[0053]
Further, as shown in FIG. 4, the joined product of the flowing water pipes 3, 4 of the water / refrigerant heat exchanger 1 and the refrigerant pipe 2 is wound into a cylindrical shape and the distal ends of the flowing water pipes 3, 4 and the refrigerant pipe 2 are bent and extended. By providing the connection portions with the pipes 5, 7, and 9 outside the cylindrical shape, the brazing operation can be easily performed, and the bend radius of each pipe can be greatly increased. The space can be effectively used and workability can be improved by wrapping around.
[0054]
In addition, by winding the joined product of the flowing water pipes 3 and 4 of the water / refrigerant heat exchanger 1 and the refrigerant pipe 2 in an elliptical shape as shown in FIG. The refrigerant heat exchanger 1 can have the shape.
[0055]
Further, as described with reference to FIG. 8, as the structure of the water / refrigerant heat exchanger 51, by joining a plurality of refrigerant pipes 51 and 53 to both side surfaces of the elliptical flowing water pipe 54, only one water heating circuit is required. A water / refrigerant heat exchanger 51 suitable for a simple water heater can be provided.
[0056]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a heat pump type water heater that requires a small space and mass for installation and has good energy efficiency using a refrigerant that is friendly to the global environment.
[Brief description of the drawings]
FIG. 1 is a diagram showing one embodiment of a water / refrigerant heat exchanger for a heat pump water heater according to the present invention.
FIG. 2 is an AA sectional view of the water / refrigerant heat exchanger shown in FIG.
FIG. 3 is a diagram showing another embodiment of the refrigerant pipe used in the water / refrigerant heat exchanger of the present invention.
FIG. 4 is a top view of the water / refrigerant heat exchanger of the present invention after molding.
FIG. 5 is a side view of the water / refrigerant heat exchanger shown in FIG. 4 after molding.
FIG. 6 is a view showing another embodiment of the shape of the water / refrigerant heat exchanger of the present invention.
FIG. 7 is a diagram showing a refrigerant circuit and a water circulation circuit of the heat pump water heater according to the present invention.
FIG. 8 is a view showing another embodiment of the structure of the water / refrigerant heat exchanger of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Water / refrigerant heat exchanger, 2 ... Refrigerant pipe, 2a ... Through hole, 3 ... Water pipe for kitchen water circulation, 3a, 4a ... Hollow part, 3b, 4b ... End part, 3c ... Winding step part, 4 ... Bath Flow pipes for water circulation 5, 6 ... refrigerant pipe, 7, 8 ... connection pipe for kitchen water circulation, 9, 10 ... connection pipe for bath water circulation, 11 ... capillary tube, 11a ... small diameter hole, 20 ... refrigerant circulation circuit, 21 ... Compressor, 22 pressure reducing device, 23 evaporator, 24 liquid receiver, 25a-25e refrigerant connection pipe, 26 bypass valve, 30 water circulation circuit, 31 water supply source, 32a, 32b, 32c check Valve, 33 ... Auxiliary tank, 34 ... Water switching valve, 35 ... Adjustment switching valve, 36 Kitchen faucet, 37a, 37b, 37c ... Flow regulating valve, 40 ... Bath faucet, 41 ... Bath water circulation pump, 42 ... Bathtub, 43 ... Bath water outlet, 44 ... Bath water inlet, 51 ... Water / refrigerant heat Exchanger, 52, 53 ... refrigerant pipe, 54 ... running water pipe.
