JP2004211998A

JP2004211998A - Air conditioning system

Info

Publication number: JP2004211998A
Application number: JP2003000946A
Authority: JP
Inventors: Masayuki Yano; 正幸谷野; Akihiko Okamura; 明彦岡村
Original assignee: Takasago Thermal Engineering Co Ltd
Current assignee: Takasago Thermal Engineering Co Ltd
Priority date: 2003-01-07
Filing date: 2003-01-07
Publication date: 2004-07-29

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioning system sparsely disposing an air cooling type outdoor unit and improving cooling performance. <P>SOLUTION: For the air conditioning system, a plurality of air conditioner sets P consisting of air cooling type outdoor units 5 and indoor units 6 are provided and an outdoor unit 5 and an indoor unit 6 are connected by a refrigerant piping 7 for passing refrigerant for each air conditioner set P. A heat exchanger 8 for cooling refrigerant flowing from the outdoor unit 5 to the indoor unit 6 by water or brine is provided for each air conditioner set P and each air conditioner set P is operable independently for cooling the refrigerator. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は，空冷個別空調方式の空調設備において冷媒を過冷却するものに関する。
【０００２】
【従来の技術】
建物の個別空調方式として，室外機と室内機とからなる空冷式の空調機セットを冷媒配管によって接続したものを用いた空調システム（パッケージエアコンによる空調システム）が知られている。かかる空調システムは，機器の低コスト化，省スペース，部屋ごとに空調運転の発停や冷・暖房の選択運転が可能等の利点がある。さらに，前記空調機セットの室外機を各階のベランダ（バルコニー）等に設置することにより，室内のレンタブル比を向上させることができる利点がある。そのため，テナントビルや小規模建物などに一般に採用されている。また，例えばインターネットデータセンター（「ＩＤＣ」サーバーを多数備えた通信施設）等，床面積当たりの冷房負荷が大きい多層建物にも使用されている。
【０００３】
前記空調機セットの室外機は，室外機内配管によって接続された圧縮機及び凝縮器を有し，室内機は室内機内配管によって接続された膨張弁及び蒸発器を有し，冷媒配管によって圧縮機・凝縮器と，膨張弁・蒸発器とが接続された構成となっており，圧縮機，凝縮器，膨張弁，蒸発器の順に通過させるように冷媒を循環させ，蒸発器の周囲に発生した冷気により室内の冷房が行なわれる。
【０００４】
一方，空冷式の室外側熱交換器（凝縮器として作用する室外機の熱交換器）と室内側熱交換器（蒸発器として作用する室内機の熱交換器）とからなる冷凍サイクルにおいて，省エネルギー又は能力不足への対処を目的とする技術として，室外側熱交換器と室内側熱交換器との間に蓄熱用の熱交換器を設け，蓄熱槽内の熱媒に冷熱を蓄熱し，当該熱媒と冷凍サイクルの冷媒との間で熱交換させる構成が提案されている（例えば，特許文献１，２，３参照）。また，室外側熱交換器と室内側熱交換器との間に，蒸発器として作用する冷媒冷却用の熱交換器を設け，この熱交換器と，凝縮器として作用する別の熱交換器と，室外機とは別の圧縮機とからなる第２の冷凍サイクルを形成し，第２の冷凍サイクルによって冷房能力を補う構成が提案されている（例えば，特許文献４参照）。これらの構成によれば，蓄熱槽内の冷熱によって冷媒を過冷却することができ，過冷却された分の冷房能力が増加する。従って，冷媒循環量を減少させることが可能となり，圧縮機の圧力を低減させた状態で運転できる。又，室外側熱交換器に空気を通過させるための室外機のファンを停止させた状態で冷房運転することも可能である。即ち，室外機の駆動力を減少させることにより，消費電力を低減し，低コストを図ることができる。
【０００５】
【特許文献１】
特開平６−９４２８４号公報（第７頁，第１図）
【特許文献２】
特開平７−４７６８号公報（第４頁，第１図）
【特許文献３】
特開平１１−３２５６４４号公報（第５頁，第１，７図）
【特許文献４】
特開平１０−３３９５１２号公報（第２頁，第１図）
【０００６】
【発明が解決しようとする課題】
従来のパッケージエアコンによる空調システムは，室内の床面積当たりの冷房負荷が大きいほど，室外機と室内機の台数を増加させる必要がある。しかしながら，室外機の台数が増加し，屋上階や各階のベランダ等に設置される室外機の密度が高くなると，室外機の排気によって室外機周辺の空気温度が上昇し，室外機の吸気温度が高くなるため，冷房能力が低下する問題があった。また，この冷房能力低下により，室外機の設置台数をより増加させる必要が生じ，設備費用が高コストとなるとともに，室外機がより高密度に設置され，冷房能力がさらに低下する問題があった。
【０００７】
また，上記特許文献１〜４に記載された構成を用いると，冷房能力を向上させることができるが，ベランダ等に蓄熱槽，第２の冷凍サイクル，蓄熱循環サイクル等を設置するスペースが確保できない問題があった。
【０００８】
従って，本発明の目的は，空冷式の室外機を低密度に配置し，かつ，冷房能力を向上させることができる空調設備を提供することにある。
【０００９】
【課題を解決するための手段】
上記課題を解決するために，本発明によれば，空冷式の室外機と室内機とからなる空調機セットを複数備えた空調設備であって，前記複数の空調機セットごとに，室外機から室内機に通流する冷媒を水又はブラインにより冷却する冷媒冷却用熱交換器をそれぞれ備え，各空調機セットごとに冷媒を冷却する運転を可能にしたことを特徴とする，空調設備が提供される。ここで，「空調機セット」とは，室内機とその室内機に冷媒配管によって接続される室外機の組み合わせをいい，冷房運転を行うものをいう。「空外機」とは，冷媒の圧縮及び凝縮を行い，大気中に高温の排気を放出して，冷媒に冷熱を吸収させる機器である。「空内機」とは，冷媒の膨張及び蒸発を行い，建物の室内に冷気を放出して冷房を行う機器である。本発明の空調設備は，例えば冷房専用の空調設備である。かかる空調設備によれば，空調機セットを冷房運転させる際，冷媒を過冷却することにより，各空調機セットの冷房能力を向上させることができる。また，一つの階の床面積当たりの冷房負荷が大きい建物であっても，空調機セット一組ごとに冷房能力を向上させることにより，一つの階の冷房を行う空調機セットの数を減少させることができる。これにより，室外機を低密度に配置できる。また，空調機セットごとに独立して過冷却運転することが可能であり，各空調機セットが賄う冷房負荷に応じて柔軟に過冷却運転又は過冷却停止運転のいずれかに運転モードを選択できる。
【００１０】
また，前記複数の室外機を建物のベランダに配置すれば，室外機の設置スペースを各階のベランダに分散できるので，前述した室外機の高密度配置の弊害を緩和できる。また，前記空調機セットを循環する冷媒が通流する冷媒配管の冷媒配管長を適切な長さにすることができ，冷房能力が低下することが無い。
【００１１】
さらに，前記水又はブラインを建物の屋上階又は地下階に配置した冷却機で冷却することが好ましい。前記冷却機による冷却は，冷熱を蓄熱する蓄熱槽を介して行うことが好ましい。そうすれば，料金が安い深夜電力を利用して冷熱を蓄熱することにより，経済性を高めることができる。
【００１２】
前記冷媒冷却用熱交換器において，地域冷暖房システムを利用して前記水又はブラインを冷却する構成としても良い。
【００１３】
前記冷媒冷却用熱交換器への前記水又はブラインの通流と遮断を切り換えられる管路を各冷媒冷却用熱交換器ごとに備えることが好ましい。
【００１４】
【発明の実施の形態】
以下，本発明の好ましい実施の形態を説明する。図１は，本発明にかかる空調設備を備えた建物１の構成を概略的に示す説明図である。建物１は複数の階層を有する。建物１の各階には，ベランダ２が設けられている。また，建物１の各階には，一台の空冷式の室外機５と一台の室内機６との組み合わせからなる冷房専用の空調機セット（空冷パッケージユニット方式のエアコン）Ｐが複数セットずつ備えられている。図１に示す例では，建物１の各階ごとに備えられた複数セットの空調機セットＰを省略して，各階ごとに空調機セットＰを１セットずつ示している。
【００１５】
さらに，各空調機セットＰにおいて，一対の室外機５と室内機６が冷媒配管７によって接続されている。室内機６は各階の室内の天井に設けられている。室外機５は，その室外機５に冷媒配管７によって接続された室内機６，即ち，対応する室内機６が配置された階のベランダ２に配置されている。従って，ベランダ２には，一階分の複数セットの空調機セットＰの室外機５，即ち，複数台の室外機５が配置されている。冷媒配管７は，室外機５から室内機６に向かって冷媒を通流させる冷媒液配管７ａと，室内機６から室外機５に向かって冷媒を通流させる冷媒ガス配管７ｂとによって構成されている。室外機５と室内機６の各構成については，後に詳しく説明する。
【００１６】
なお，室外機５と室内機６を同じ階に配置することにより，室外機５と室内機６の高低差を小さくすることができるので，冷媒配管７のうち縦引き配管部分を短くすることができる。又，冷媒配管７を横引き配管のみにすることも可能である。従って，縦引き配管部分と横引き配管部分を含めた冷媒配管７全体の長さを最大冷媒配管長以下に十分短くすることができ，配管抵抗を少なくして，空調機セットＰの冷房能力を十分確保できる。また，冷媒を送給する動力を低減して，省電力，省コストを図ることができる。さらに，室外機５の設置スペースを各階のベランダ２に分散することにより，室外機５の高密度配置の弊害，即ち，高温排気による外気温度の上昇を緩和できる。
【００１７】
また，各空調機セットＰごとに，室外機５から室内機６に向かって流れる冷媒液配管７ａ内の冷媒を熱媒により冷却する冷媒冷却用熱交換器８がそれぞれ備えられている。各冷媒冷却用熱交換器８は，対応する冷媒液配管７ａの途中にそれぞれ介設されている。冷媒冷却用熱交換器８も，その冷媒冷却用熱交換器８が介設されている冷媒配管７が接続された室内機６，即ち，対応する室内機６が配置された階のベランダ２に配置されている。従って，ベランダ２には，複数台の室外機５の他に，一階分の複数セットの空調機セットＰの冷媒冷却用熱交換器８，即ち，複数台の冷媒冷却用熱交換器８が配置されている。なお，冷媒冷却用熱交換器８は，プレート型熱交換器であり，室外機５と比較して小さいため，ベランダ２に配置しても室外機５の配置の邪魔にならない。熱媒としては，水又はブラインが使用される。
【００１８】
建物１の屋上階ＲＦには，熱媒を冷却する熱媒冷却機１０が配置されている。各階の総てのベランダ２に配置された全部の冷媒冷却用熱交換器８は，熱媒を通流させる熱媒配管１１によって，一つの熱媒冷却機１０に接続されている。また，熱媒配管１１には，熱媒を循環させるための図示しないポンプが介設されており，ポンプも屋上階ＲＦに配置されている。
【００１９】
熱媒配管１１は，熱媒冷却機１０から冷媒冷却用熱交換器８に向かって熱媒を通流させる熱媒供給配管１１ａと，冷媒冷却用熱交換器８から熱媒冷却機１０に向かって冷媒を通流させる熱媒回収配管１１ｂとによって構成されている。熱媒配管１１は，各階のベランダ２と屋上階ＲＦとの間で縦引き配設されており，各階のベランダ２では，横引き配設されている。熱媒供給配管１１ａは，各階の高さで一本ずつ分岐して，さらに，この分岐管（図示せず）が各冷媒冷却用熱交換器８の近傍で一本ずつ細管１１ｃに分岐して，この細管１１ｃが，各冷媒冷却用熱交換器８の熱媒入口にそれぞれ接続するように配設され，各冷媒冷却用熱交換器８に熱媒を分流させて供給する構成になっている。熱媒回収配管１１ｂは，各冷媒冷却用熱交換器８の熱媒出口に一本ずつ接続された細管１１ｄを各冷媒冷却用熱交換器８の近傍で一本ずつ合流させて，さらに，この合流管を各階の高さで一本ずつ合流させ，この合流管（図示せず）を熱媒冷却機１０に接続するように配設され，各冷媒冷却用熱交換器８から熱媒を回収して熱媒冷却機１０に戻す構成となっている。
【００２０】
図２に示すように，各冷媒冷却用熱交換器８の近傍には，熱媒配管１１のバイパス管１１ｅが，各冷媒冷却用熱交換器８に対してそれぞれ並列に設けられている。バイパス管１１ｅの上流端は，熱媒供給配管１１ａの細管１１ｃの途中に接続され，バイパス管１１ｅの下流端は，熱媒回収配管１１ｂの細管１１ｄの途中に接続されている。
【００２１】
バイパス管１１ｅには，バイパス開閉弁Ｖ１が介設されている。また，細管１１ｃにおいてバイパス管１１ｅの分岐位置より下流側には，開閉弁Ｖ２が介設されている。細管１１ｃにおいてバイパス管１１ｅの合流位置より上流側には，開閉弁Ｖ３が介設されている。バイパス開閉弁Ｖ１を閉じて，開閉弁Ｖ２，Ｖ３を開くと，バイパス管１１ｅへの熱媒の通流を遮断し，冷媒冷却用熱交換器８に熱媒を通流させる状態となり，バイパス開閉弁Ｖ１を開いて，開閉弁Ｖ２，Ｖ３を閉じると，バイパス管１１ｅに熱媒を通流させ，冷媒冷却用熱交換器８への通流を遮断する状態となる。このように，バイパス開閉弁Ｖ１，開閉弁Ｖ２，Ｖ３の各開閉操作によって，バイパス管１１ｅへの熱媒の通流と冷媒冷却用熱交換器８への熱媒の通流を切り換える構成となっている。即ち，バイパス開閉弁Ｖ１を有するバイパス管１１ｅ，開閉弁Ｖ２を有する熱媒供給配管１１ａの細管１１ｃ，開閉弁Ｖ３を有する熱媒回収配管１１ｂの細管１１ｄによって，冷媒冷却用熱交換器８への熱媒の通流と遮断を切り換えられる切換管路１２が形成されている。この切換管路１２は，各冷媒冷却用熱交換器８に対応させて備えられており，各切換管路１２の通流と遮断の切り換えを個別に行うことにより，各冷媒冷却用熱交換器８への熱媒の通流と遮断を個別に切り換えることができる。
【００２２】
熱媒は，熱媒冷却機１０において冷却され，熱媒供給配管１１ａを通過して屋上階ＲＦから各ベランダ２の冷媒冷却用熱交換器８に向かって下降し，冷媒冷却用熱交換器８又はバイパス管１１ｅを通流した後，熱媒回収配管１１ｂを通過して屋上階ＲＦの熱媒冷却機１０に向かって上昇して，再び熱媒冷却機１０において冷却される。熱媒冷却機１０において冷熱が与えられた熱媒が冷媒冷却用熱交換器８を通流する場合，室外機５において圧縮・凝縮された冷媒と熱交換して，冷媒に冷熱が与えられ過冷却される。
【００２３】
次に，空調機セットＰと冷媒冷却用熱交換器８によって構成される冷凍サイクルについて詳細に説明する。図２に示すように，室外機５は，アキュームレータ１３と，圧縮機１４と，四方弁１５と，凝縮器１６とを備えている。また，前記四方弁１５，アキュームレータ１３，圧縮機１４，四方弁１５，凝縮器１６の順に冷媒を通流させる室外機内流路１７を内蔵している。さらに，室外機５には，外気を吸い込む図示しない吸い込み口と，外気を排出する図示しないフードとが設けられている。
【００２４】
四方弁１５は４つの出入口１５ａ，１５ｂ，１５ｃ，１５ｄを備えている。四方弁１５の内部は，第１の出入口１５ａと第２の出入口１５ｂとが接続され，第３の出入口１５ｃと第４の出入口１５ｄとが接続された状態となっている。第１の出入口１５ａには，室内機６の冷媒入口に接続された室外機内流路１７が接続されている。第２の出入口１５ｂには，アキュームレータ１３の冷媒入口に接続された室外機内流路１７が接続されている。第３の出入口１５ｃには，圧縮機１４の冷媒出口に接続された室外機内流路１７が接続されている。第４の接続口１５ｄには，凝縮器１６の冷媒入口に接続された室外機内流路１７が接続されている。なお，アキュームレータ１３の冷媒出口に接続された室外機内流路１７は圧縮機１４の冷媒入口に接続され，凝縮器１６の冷媒出口に接続された室外機内流路１７は室内機６の冷媒出口に接続されている。
【００２５】
室内機６は，膨張弁１８と，蒸発器１９とを備えている。さらに，前記膨張弁１８，蒸発器１９の順に冷媒を通流させる室内機内流路２０を内蔵している。
【００２６】
冷媒冷却用熱交換器８は，プレート型熱交換器である。図２に示すように，冷媒冷却用熱交換器８は，冷媒を通過させる器内冷媒流路２２と，熱媒を通過させる器内熱媒流路２３とを内蔵している。
【００２７】
室外機内流路１７には，室外機５の冷媒入口を介して冷媒ガス配管７ｂの下流端が接続され，室外機５の冷媒出口を介して冷媒液配管７ａの上流端が接続されている。器内冷媒流路２２には，冷媒冷却用熱交換器８の冷媒入口を介して冷媒液配管７ａの上流側が接続され，冷媒冷却用熱交換器８の冷媒出口を介して冷媒液配管７ａの下流側が接続されている。室内機内流路２０には，室内機６の冷媒入口を介して冷媒液配管７ａの下流端が接続され，室外機５の冷媒出口を介して冷媒ガス配管７ｂの上流端が接続されている。即ち，室外機内流路１７，冷媒液配管７ａ，器内冷媒流路２２，冷媒液配管７ａ，室内機内流路２０，冷媒ガス配管７ｂの順に冷媒を循環させる冷媒循環回路２４が構成されている。
【００２８】
一方，器内熱媒流路２３には，冷媒冷却用熱交換器８の熱媒入口を介して熱媒供給配管１１ａの下流端（細管１１ｃの下流端）が接続され，冷媒冷却用熱交換器８の熱媒出口を介して熱媒回収配管１１ｂの上流端（細管１１ｄの上流端）が接続されている。即ち，熱媒供給配管１１ａ，器内熱媒流路２３，熱媒回収配管１１ｂの順に熱媒を通流させる熱媒供給回路２５が構成されている。
【００２９】
空調機セットＰを運転させると，室外機５，冷媒冷却用熱交換器８，室内機６の順に冷媒循環回路２４内の冷媒が循環する。即ち，室内機６の蒸発器１９から室外機５に送給された冷媒は，四方弁１５，アキュームレータ１３を介して圧縮機１４に送給され，圧縮機１４によって圧縮されて高温高圧で吐出され，四方弁１５を介して凝縮器１６に送給され，凝縮器１６において凝縮し，冷媒冷却用熱交換器８内の器内冷媒流路２２を通過し，室内機６に送給される。室内機６に送給された冷媒は，膨張弁１８において断熱膨張し，蒸発器１９において蒸発して，室外機５に戻る。また，室外機５の図示しない吸い込み口から外気が吸い込まれ，凝縮器１６において冷媒が冷熱を吸収して凝縮するとき，凝縮器１８の周囲で外気が高温となり，図示しないフードから放出され，ベランダ２の外側に向かって排気される。また，室内機６において冷媒が蒸発するとき，蒸発器１９の周囲に冷気が発生し，室内機６内に備えられた図示しない送風機により冷気が送風され，室内に給気される。これにより，室内空気が冷却される。
【００３０】
冷媒が器内冷媒流路２２を通流するとき，バイパス開閉弁Ｖ１を閉じ，かつ，開閉弁Ｖ２，Ｖ３を開くことにより，熱媒冷却機１０において冷熱が与えられた熱媒が器内熱媒流路２３内に通流している状態にしておくと，冷媒冷却用熱交換器８において，器内冷媒流路２２を通流する冷媒と器内熱媒流路２３を通流する熱媒とが熱交換する。即ち，熱媒冷却機１０において冷熱が与えられ器内熱媒流路２３に送給された熱媒と，室外機５において圧縮・凝縮され器内冷媒流路２２に送給された冷媒とが熱交換して，冷媒が過冷却される。このように，室外機５において圧縮・凝縮された後室内機６において膨張・蒸発する前に，冷媒を過冷却すると，圧縮・凝縮された冷媒が過冷却された分だけ空調機セットＰの冷房能力を増加させることができる。一方，冷媒が器内冷媒流路２２を通過するとき，バイパス開閉弁Ｖ１を開き，かつ，開閉弁Ｖ２，Ｖ３を閉じることにより，器内熱媒流路２３内に熱媒が通流していない状態にしておくと，室外機５において圧縮・凝縮された冷媒が，冷媒冷却用熱交換器８において熱媒と熱交換せず，素通りして室内機６に供給される。以上のようなバイパス開閉弁Ｖ１，開閉弁Ｖ２，Ｖ３の開閉操作を各空調機セットＰに対応して設けられた切換管路１２について個別に行うことにより，各空調機セットＰの運転モードを，冷媒を過冷却する過冷却運転，冷媒を過冷却せず運転する過冷却停止運転のいずれかに個別に切り替えることができる。
【００３１】
図１に示すように，屋上階ＲＦに配置された熱媒冷却機１０は，冷凍した熱媒を貯留することにより冷熱を蓄熱する熱媒冷却用蓄熱装置２７と，熱媒冷却用蓄熱装置２７内の熱媒に冷熱を与える製氷用冷凍機２８とを備えている。
【００３２】
熱媒冷却用蓄熱装置２７は，スタティック型外融式の氷蓄熱装置であり，熱媒を貯留して冷熱を蓄熱する蓄熱槽３０と，蓄熱槽３０内部に設けられた蓄熱槽内熱交換器３１とによって構成されている。蓄熱槽３０は，屋上階ＲＦに配置され，熱媒供給配管１１ａの上流端と熱媒回収配管１１ｂの下流端が接続されている。即ち，熱媒配管１１によって，２７０台の冷媒冷却用熱交換器８が，熱媒冷却用蓄熱装置２５の蓄熱槽３０に接続されている。前述の熱媒供給回路２５は，蓄熱槽３０，熱媒供給配管１１ａ，器内熱媒流路２３，熱媒回収配管１１ｂの順に熱媒を循環させる。熱媒は，製氷用冷凍機２８の蓄熱運転によって，蓄熱槽３０を介して冷却される。
【００３３】
製氷用冷凍機２８は，屋上階ＲＦに配置されており，図示しない冷凍機内熱交換器を内蔵している。蓄熱槽内熱交換器３１と冷凍機内熱交換器は，製氷用熱媒を通流させる製氷用熱媒配管３３によって接続されており，蓄熱槽内熱交換器３１，製氷用熱媒配管３３，冷凍機内熱交換器の順に製氷用熱媒を循環させる製氷用熱媒循環回路３４が構成されている。
【００３４】
ここで，熱媒冷却機１０における冷熱の蓄熱（製氷）運転について説明する。製氷用冷凍機２８において冷却された製氷用熱媒は，製氷用熱媒配管３３によって製氷用冷凍機２８から製氷用熱交換器３１に送給され，製氷用熱交換器３１の周囲の熱媒と熱交換して，熱媒に冷熱を与え，製氷用熱媒配管３３によって再び製氷用冷凍機２８に戻り，冷却される。このように，製氷用冷凍機２８において生成された冷熱が，製氷用熱媒を介して蓄熱槽３０内の熱媒に供給され，熱媒が冷凍されて氷状となる。製氷用熱交換器３１の周囲で冷凍された熱媒は，蓄熱槽３０内に氷として蓄積される。即ち，冷凍された熱媒を貯留することにより蓄熱槽３０内に冷熱を蓄熱する。この蓄熱（製氷）運転は，電気料金の安い夜間電力を使用して行うことが好ましい。この場合，熱媒冷却機１０の運転にかかる電気料金を削減し，ひいては，空調設備全体の運転にかかる電気料金を削減できる。
【００３５】
なお，蓄熱槽３０内に氷として蓄積された熱媒は，熱媒供給回路２５内を流れる冷水と熱交換して冷熱を冷水に付与し続ける。そして，その冷水は，前述のように各冷媒冷却用熱交換器８に供給されて冷媒に冷熱を与え，再び蓄熱槽３０内に貯留され，蓄熱運転によって冷凍される。
【００３６】
前述のように，室外機５と室内機６を接続する冷媒配管７は，圧縮機の吸入圧力低下や配管抵抗増加等を防止して冷房能力を十分確保するための最大冷媒配管長が決められているため，冷媒循環回路２４は熱輸送の距離に制約がある。一方，熱媒供給回路２５は，冷水を熱媒とする水循環系であり，熱媒配管１１の長さには，冷媒配管７のような配管長の制約が無く，長距離の熱輸送に適している。そのため，室内機６に対応する室外機５を同じ階のベランダ２に配置することにより，冷媒配管７をできるだけ短くして，冷媒冷却用熱交換器８を各階のベランダ２に配置し製氷用冷凍機２８と蓄熱槽３０を屋上階ＲＦに配置することにより，熱媒配管１１の長さを冷媒配管７と比較して長くすることが好ましい。この場合，空調機セットＰの冷房能力を十分確保できる。
【００３７】
例えば，過冷却運転中に蓄熱槽３０内に蓄積された氷の量が不足しそうになった場合は，任意の空調機セットＰの運転モードを過冷却停止運転に切り換える。例えば，賄う冷房負荷が比較的低い状態にある空調機セットＰを選択して，過冷却停止運転に切り換える。即ち，選択した空調機セットＰについて，バイパス開閉弁Ｖ１を開いて開閉弁Ｖ２，Ｖ３を閉じることにより，冷媒冷却用熱交換器８への熱媒の通流を遮断し，バイパス管１１ｅに熱媒を通流させ，過冷却を行わずに冷媒を通流させる。また，仮に，過冷却運転中に熱媒配管１１，熱媒配管１１に備えたポンプ，蓄熱槽３０等が故障して，熱媒供給回路２５の熱媒の供給が不可能になった場合も，任意の空調機セットＰの運転モードを過冷却停止運転に切り換える。こうすることにより，過冷却運転時より冷房能力を低下させながらも，過冷却停止運転による冷房運転を継続させることができる。このように，空調機セットＰごとに独立して過冷却運転することが可能であり，各空調機セットＰが賄う冷房負荷，蓄熱槽３０や熱媒配管１１の状態等に応じて，各空調機セットＰごとに，柔軟に過冷却運転又は過冷却停止運転のいずれかに運転モードを選択できる。なお，運転モードを過冷却停止運転に切り換えた空調機セットＰの冷房能力が零になることはなく，過冷却停止運転時と同じ冷房能力が維持できる。即ち，本発明の空調設備は，過冷却運転時の冷房能力について，過冷却停止運転時の冷房能力に相当する冗長性が確保されている。
【００３８】
また，本発明の空調設備は，過冷却運転によって空調機セットＰ一組ごとの冷房能力を向上させることにより，過冷却運転のための構成を有しない従来型の空調設備よりも，空調機セットＰのセット数を減少させることができる。これにより，ベランダ２に室外機５を低密度に配置できる。即ち，各室外機５が互いの排気を吸い込まないように，各室外機５を互いに十分な間隔を設けて配置できる。従って，高温排気の吸い込みによる室外機５の熱交換能力低下や，運転停止が起こる心配が無い。なお，冷媒冷却用熱交換器８は，プレート型熱交換器であり，室外機５と比較して小さく，省スペースを実現でき，ベランダ２に配置しても室外機５の低密度配置の邪魔にならない。
【００３９】
次に，過冷却運転の効果について，より具体的に説明する。本発明者は，本発明の空調設備を設置する建物を具体的に想定し，想定した建物の設計熱負荷に必要な空調機セットＰの個数，各空調機セットＰに必要な冷房能力，各空調機セットＰの消費電力等を試算した。また，想定した建物に，冷媒冷却用熱交換器８を備えず過冷却運転を行わない従来型の空調設備を設置する場合と比較した。
【００４０】
想定した建物１は６階建てであり，１階から６階までの各階は，ＩＤＣとして使用される。建物１の１階から６階までの各階の空調エリアは，それぞれ約２５００ｍ^２程度である。また，各階の空調エリアにおける床面積当たりの設計熱負荷は，約０．８ｋＷ／ｍ^２と定められている。即ち，各空調エリアに必要な設計熱負荷は，約２０００ｋＷ程度である。
【００４１】
なお，ＩＤＣは，一般的な電算センターより高密度に発熱するため，顕熱負荷が高い。また，室内に人間が出入りすることが少なく，通常は無人であり，保守員などが必要なときに小人数入室する。従って，人体から発生する水蒸気が微少であり，潜熱負荷が極小である。
【００４２】
建物１の１階から６階までの各階には，一台の空冷式の室外機５と一台の室内機６からなる冷房専用の空調機セット（空冷パッケージユニット方式のエアコン）Ｐが４５セットずつ備えられる。建物１全体では，４５セット×６階＝２７０セットの空調機セットＰが備えられる。従って，ベランダ２には，４５台の室外機５の他に，一階分の４５セットの空調機セットＰの冷媒冷却用熱交換器８，即ち，４５台の冷媒冷却用熱交換器８が配置される。１階から６階までの総てのベランダ２に配置された全部で２７０台の冷媒冷却用熱交換器８は，熱媒を通流させる熱媒配管１１によって，熱媒冷却機１０の蓄熱槽３０に接続されている。蓄熱槽３０の容積は約２７１ｍ^３程度であり，ＩＰＦ（氷充てん率）は約４０％程度である。製氷用冷凍機２８の定格能力は約９７１ｋＷ（２７６Ｒｔ）程度であり，ＣＯＰ（成績係数）は約２．００程度である。
【００４３】
各空調機セットＰの定格能力（室外機５の周囲の外気温度（室外機５に吸気される空気の温度）が３５℃のときの冷房能力）は，過冷却停止運転では約３７．５ｋＷ程度であり，過冷却運転では約４５ｋＷ程度である。各階の各空調エリアに必要な設計熱負荷約２０００ｋＷは，空調機セットＰ４５セット分の過冷却運転によって賄うことができる。また，過冷却運転時の各空調機セットＰの冷房能力は，過冷却停止運転時よりも約２０％程度向上する。換言すれば，仮に過冷却運転時に熱媒配管１１，熱媒配管１１に備えたポンプ，蓄熱槽３０等が故障して，熱媒供給回路２５の熱媒の供給が不可能になった場合も，空調設備の冷房能力が零になることはなく，過冷却停止運転時と同じ冷房能力，即ち，過冷却運転の約８０％程度の冷房能力が維持できるといえる。即ち，この空調設備の過冷却運転時の冷房能力については，約８０％程度の冗長性が確保されている。
【００４４】
なお，定格能力の運転時に，圧縮機１６の駆動等により必要とされる各室外機５の消費電力は，過冷却停止運転時も過冷却運転時も，約１４．２ｋＷ程度である。各空調機セットＰのＣＯＰは，定格能力の過冷却停止運転時で約２．６４程度，定格能力の過冷却運転時で約３．１７程度である。
【００４５】
従来型の空調設備の場合，各空調機セットＰの定格能力は上記の過冷却停止運転時と同じ約３７．５ｋＷ程度のままであり，各階の各空調エリアに必要な設計熱負荷約２０００ｋＷを賄うためには，１階分の空調機セットＰを４５セット以上備える必要がある。しかしながら，室外機５をベランダ２に十分な間隔を設けて配置することができず，室外機５の高温排気によって外気温度が３５℃以上に上昇する虞がある。この場合，各空調機セットＰは定格能力で運転できず，冷房能力が３７．５ｋＷ以下に低下するため，冷房能力の低下を考慮して，さらに空調機セットＰを増加させる必要がある。また，冷媒循環量を増加させるために圧縮機１６の駆動力を増加させることにより，室外機５の消費電力が上昇する虞がある。
【００４６】
これに対し，本発明の空調設備の場合，４５台の室外機５は互いの排気を吸い込まないようにベランダ２に低密度に配置することができる。過冷却停止運転時も過冷却運転時も，外気温度が約３５℃以上になることを防止できる。従って，過冷却停止運転時も過冷却運転時も，定格能力以上の冷房能力で運転できる。
【００４７】
本発明者は，建物１に従来型の空調設備を設けた場合に，各階の設計熱負荷約２０００ｋＷを賄うために必要な空調機セットＰの個数と，室外機５周囲の外気温度，各空調機セットＰの冷房能力，各室外機５の消費電力を試算した。その結果，建物１の各階にそれぞれ必要な空調機セットＰの個数は５６セットであり，６階建ての建物１全体では，必要な空調機セットＰの個数は５６セット×６階＝３３６セットである。このとき，各ベランダ２に配置された５６台の室外機５周囲の外気温度（室外機５の吸気温度）は，各室外機５の排気により，約４０℃程度に上昇する。
【００４８】
ここで，各空調機セットＰの冷房能力，各室外機５の消費電力の試算に使用した能力線図について説明する。図３は，単体の空調機セットＰの冷房能力と外気温度の関係を示した能力線図である。図４は，単体の空調機セットＰの消費電力と外気温度の関係を示した能力線図である。図３において，横軸は外気温度（℃）を示し，縦軸は冷房能力（ｋＷ）を示している。図４において，横軸は外気温度（℃）を示し，縦軸は消費電力（ｋＷ）を示している。
【００４９】
外気温度が約４０℃程度の場合，図３の能力線図から理解されるように，各空調機セットＰの冷房能力は約３６．０ｋＷ程度となり，図４の能力線図から理解されるように，各室外機５の消費電力は，約１５．１ｋＷ程度である。さらに，外気温度は約４３℃程度に上昇する場合があることが経験上明らかである。外気温度約４３℃程度の場合，図３の能力線図から理解されるように，各空調機セットＰの冷房能力は約３５．４ｋＷ程度に減少する。なお，中間期（春季及び秋季），冬季では，夏季より外気温度が下がるため，夏季と比較して，より節電できる（ＣＯＰが向上する）。
【００５０】
また，建物１に従来型の空調設備を設けた場合の各空調機セットＰのＣＯＰは約２．３８程度である。
【００５１】
即ち，本発明者の試算によれば，本発明の空調設備を適用することにより，従来型の空調設備と比較して，建物１の各階にそれぞれ必要な空調機セットＰを１１セット減少（約２０％程度減少）させることができる。従って，各ベランダ２に配置される室外機５と冷媒冷却用熱交換器８の数をそれぞれ１１台減少させ，互いに間隔を広くとることができる。さらに，外気温度を約４℃程度低下させることができる。各空調機セットＰの冷房能力を，過冷却停止運転時において約１．５ｋＷ程度増加（約４％程度増加）させることができる。各室外機５の消費電力を約０．９ｋＷ程度減少（約６％程度減少）させることができる。各空調機セットＰのＣＯＰを約０．２６程度増加（約１０％程度増加）させることができる。
【００５２】
また，本発明者は，建物１に本発明の空調設備を設けた場合と，従来型の空調設備を設けた場合について，空調設備に必要な年間消費電力と年間電力料金をそれぞれ試算した。図５は，本発明の空調設備と従来型の空調設備の年間消費電力を示すグラフであり，図６は，本発明の空調設備と従来型の空調設備の年間消費電力を比較した表である。図７は，本発明の空調設備と従来型の空調設備の年間電力料金を示すグラフであり，図８は，本発明の空調設備と従来型の空調設備の年間消費電力を比較した表である。図５において，縦軸は，空調設備全体の年間消費電力（ｋＷ）を示し，グラフ棒ａは本発明の空調設備の年間消費電力を示し，グラフ棒ｂは従来型の空調設備の年間消費電力を示している。図７において，縦軸は，空調設備全体の年間電力料金（万円）を示し，グラフ棒ｃは本発明の空調設備の年間電力料金を示し，グラフ棒ｄは従来型の空調設備の年間電力料金を示している。
【００５３】
ここで，図５〜図８のグラフ及び表に示した年間消費電力と年間電力料金の試算の際に想定した熱負荷形状を，図９及び図１０に示す。図９は，想定した一日の熱負荷を示すグラフである。図１０は，想定した年間の熱負荷を示すグラフである。図９において，横軸は１日の時刻を示し，縦軸は，１日の全熱負荷に対する熱負荷の割合（％）を示している。図１０において，横軸は月数を示し，縦軸は，１年間の全熱負荷に対する熱負荷の割合（％）を示している。図９に示すように，１日の熱負荷の時間変動については，気温の変動による外気温度の変動を考慮して，時間変動７０％〜１００％と仮定した。また，図１０に示すように，１年間の熱負荷の季節変動については，気温の変動による外気温度の変動を考慮して，季節変動８０％〜１００％と仮定した。
【００５４】
図５及び図６に示すグラフ及び表から理解されるように，本発明の空調設備は，従来型の空調設備の約９４％程度に年間消費電力を削減できる。また，図７及び図８に示すグラフ及び表から理解されるように，本発明の空調設備は，従来型の空調設備の約９２％程度に年間電力料金を削減できる。
【００５５】
さらに，本発明者は，建物１に本発明の空調設備を設けた場合と，従来型の空調設備を設けた場合について，設備費（イニシャルコスト）及び電気料金（ランニングコスト）を比較した。本発明の空調設備に必要な設備費は，従来型の空調設備より，熱媒供給回路３の設備費の約１１０４０万円程度増額する。一方，本発明の空調設備は，従来型の空調設備より空調機セットＰが６６セット少ないので，単体の空調機セットＰの設備費は約８０万円程度とすると，約５２８０万円程度減額できる。従って，本発明の空調設備の設備費は，従来型の空調設備より約５７６０万円程度の増額となる。しかしながら，本発明の空調設備は，前述のように従来型の空調設備より消費電力を削減でき，図７及び図８に示すグラフ及び表から理解されるように，年間では約２２５６万円の電気料金の削減が可能である。従って，本発明の空調設備にかかる設備費の増額分は，電気料金の削減により，約２年間程度で回収することが可能である。そして，設備費を回収した後，即ち，本発明の空調設備を設置してから約２年経過後も，電気料金を低額に抑えることができる。従って，設備費及び空調設備設置後の総ての電気料金を含めた全額を比較すると，本発明の空調設備は，従来型の空調設備より経済性を高めることが可能であると理解される。
【００５６】
また，本発明者は，８月の最大負荷日（年間の最大負荷日），８月の代表日（夏季代表日）及び１月の代表日（冬季代表日）における各消費電力を，本発明の空調設備と従来型の空調設備について，それぞれ試算した。図１１は，８月の最大負荷日における，本発明の空調設備の消費電力を試算した結果を示すグラフである。図１２は，８月の最大負荷日における，従来型の空調設備の消費電力を試算した結果を示すグラフである。図１３は，８月の代表日における，本発明の空調設備の消費電力を試算した結果を示すグラフである。図１４は，８月の代表日における，従来型の空調設備の消費電力を試算した結果を示すグラフである。図１５は，１月の代表日における，本発明の空調設備の消費電力を試算した結果を示すグラフである。図１６は，１月の代表日における，従来型の空調設備の消費電力を試算した結果を示すグラフである。図１１〜図１６において，横軸は１日の時刻を示し，縦軸は，空調設備全体の消費電力（ｋＷ）を示している。また，図１１，図１３，図１５において，グラフ棒ｅは熱媒冷却機１０の蓄熱運転に必要な消費電力を示し，グラフ棒ｆは過冷却運転に必要な消費電力を示している。
【００５７】
図１１〜図１６のグラフより，本発明の空調設備は，電力需要の平準化ができることがわかる。特に，図１３のグラフから理解されるように，８月の代表日では，熱媒冷却機１０の蓄熱運転は夜間のみ行えばよく，電力の夜間移行が実現されている。また，図１５のグラフから理解されるように，１月の代表日では，熱媒冷却機１０の蓄熱運転は夜間の約４時間のみ行えばよい。
【００５８】
かかる本発明の空調設備によれば，熱媒供給回路３によって冷媒を過冷却し，冷媒が過冷却された分だけ空調機セットＰの冷房能力を増加させることができるので，ＩＤＣのような熱負荷の高い施設であっても，空調機セットＰの設置台数を適正な数に減少させることができる。この場合，各ベランダ２に配置される室外機５と冷媒冷却用熱交換器８の設置台数が減少するので，これらの間の間隔を互いに広くとり，各ベランダ２の面積に対して低密度に配置できるため，外気温度を適正な温度に保つことができる。従って，各空調機セットＰの冷房能力が損なわれず，高効率な定格能力の運転が可能である。これにより，各室外機５の消費電力を減少させることができ，各空調機セットＰのＣＯＰを増加させることができる。
【００５９】
さらに，空調設備全体の消費電力と電力料金を削減できる。電気料金の削減により設備費の増額分を回収し，設備費及び空調設備設置後の総ての電気料金を含めた全額を低減できる。
【００６０】
また，蓄熱運転を夜間に行うことにより，電力の夜間移行が可能であり，電力需要の平準化ができる。安価な夜間電力を活用することで，空調設備全体の電力料金をさらに削減できる。
【００６１】
以上，本発明の好適な実施の形態の一例を示したが，本発明はここで説明した形態に限定されないことは勿論であり，適宜変更実施することが可能である。本発明の空調設備は，実施の形態に示したＩＤＣとしての建物１の他，例えば百貨店，オフィスビルに適用しても有効である。また，セントラル方式の空調設備と本発明の空調設備を組み合わせて，建物に設置しても良い。この場合も，建物の空調設備全体の能力を増強し，省電力を図ることができる。
【００６２】
本実施の形態では，室内機６に対応する室外機５を同じ階のベランダ２に配置したが，冷媒配管長の制約を満たす場合であれば，室外機５を他の階のベランダ２や，屋上階ＲＦに配置することもできる。
【００６３】
建物１は６階建てとしたが，勿論，６階以外の階数としても良い。階数の増加により，屋上階ＲＦの熱媒冷却機１０と１階の冷媒冷却用熱交換器８との間の距離が大きくなっても，熱媒配管１１は長距離の冷熱輸送が可能であるため，最上階の空調機セットＰから１階の空調機セットＰまで，冷媒の過冷却を十分に行うことができる。
【００６４】
本実施の形態では，室外機５と室内機６をそれぞれ一台ずつ備えた空調機セットＰについて説明したが，空調機セットは，例えば，複数台の室内機を室内機の台数より少ない台数の室外機に接続して構成されたマルチパッケージエアコンや，ビル用マルチであっても良い。例えば，図１７に示すように，２台の室内機６ａ，６ｂを１台の室外機５に接続するマルチパッケージエアコンＰ’の場合は，冷媒液配管７ａを冷媒冷却用熱交換器８の下流で２本に分岐させ，一方の分岐管に室内機６ａを接続し，他方の分岐管に室内機６ｂを接続する。また，冷媒ガス配管７ｂの上流側を２本に分岐させ，一方の分岐管に室内機６ａの冷媒出口を接続し，他方の分岐管に室内機６ｂの冷媒出口を接続する。即ち，冷媒液配管７ａ，室内機６ａに備えた室内機内配管２０ａ，冷媒ガス配管７ｂ，室外機内配管１７をこの順に接続した冷媒循環回路と，冷媒液配管７ａ，室内機６ｂに備えた室内機内配管２０ｂと，冷媒ガス配管７ｂ，室外機内配管１７をこの順に接続した冷媒循環回路とを構成する。室内機６ａ，６ｂに分岐させて送給する圧縮・凝縮された冷媒を冷媒冷却用熱交換器８にて過冷却することにより，マルチパッケージエアコンＰ’全体の冷房能力を向上させることができる。
【００６５】
空調機セットＰは，冷房専用のものであってもよいが，例えばヒートポンプ方式のパッケージエアコン等，冷房運転の他に暖房運転を行うことも可能な構成のものであってもよい。例えば，図２において，室外機５内の凝縮器１６は，冷房運転時に凝縮器として作用し，暖房運転時に蒸発器として作用する熱交換器として構成する。また，室内機６内の蒸発器１９は，冷房運転時に蒸発器として作用し，暖房運転時に凝縮器として作用する熱交換器として構成する。四方弁１５は，冷房運転時には第１の接続口１５ａと第２の接続口１５ｂとを接続し，第３の接続口１５ｃと第４の接続口１５ｄとを接続した状態にし，暖房運転時には第１の接続口１５ａと第４の接続口１５ｄとを接続し，第２の接続口１５ｂと第３の接続口１５ｃとを接続した状態にするように，切り換え動作が可能な構成とする。さらに，室内機６内には，冷房運転時に蒸発器１９に通流させる冷媒を膨張させる膨張弁（図示せず）を備える。冷房運転時には，室内機６内の熱交換器（蒸発器１９），四方弁１５，アキュームレータ１３，圧縮機１４，四方弁１５，室外機５内の熱交換器（凝縮器１６），膨張弁１８，室内機６内の熱交換器（蒸発器１９）の順に冷媒を循環させる。一方，四方弁１５を切り換えて，室内機６内の凝縮器として作用する熱交換器，膨張弁１８，室外機５内の蒸発器として作用する熱交換器，四方弁１５，アキュームレータ１３，圧縮機１４，四方弁１５，室内機６内の凝縮器として作用する熱交換器の順に冷媒を循環させることができる。この場合，室内機６内の熱交換器において冷媒が冷熱を吸収して凝縮するとき，室内機６内の熱交換器の周囲に暖気が発生し，室内機６内に備えられた図示しない送風機により暖気が送風されて室内に給気され，室内を暖房することができる。このような，冷房運転と暖房運転が可能な構成の空調機セットＰを備えた空調設備においても，各空調機セットＰを冷房運転させる際，本発明を好適に実施可能である。
【００６６】
熱媒としては，本実施の形態に示した冷水の他，フロン系冷媒，ＣＯ_２（二酸化炭素），アンモニア系冷媒，氷スラリーを使用することもできる。また，熱媒冷却用蓄熱装置２５は，スタティック型外融式の氷蓄熱装置として説明したが，勿論，その他種々の蓄熱装置としても良い。例えば，外融式であっても内融式であっても良く，ダイナミック型の蓄熱装置であっても良い。
【００６７】
また，冷媒冷却用熱交換器８の熱媒の通過をコントローラによって制御しても良い。例えば，図１８に示すように，１階から６階までの各階に，コントローラ３７をそれぞれ設ける。各室外機５に，各室外機５の運転状態（圧縮機１６の運転状態）を検出する図示しないセンサーを設け，センサーの運転情報信号を，そのセンサーが設けられた室外機５が配置された階のコントローラ３７に送信するように構成する。また，室内の温度を測定する図示しない温度センサーを，室内機６内部に設け，温度センサーの温度検出信号を，その温度センサーが設けられた室内機６が配置された階のコントローラ３７に送信するように構成する。さらに，蓄熱槽３０に，蓄熱槽３０内部に貯留されている蓄氷量を検出する図示しない蓄氷量センサーを設け，蓄氷量センサーからの残蓄氷量検出信号を，１階から６階までの各階のコントローラ３７にそれぞれ送信するように構成する。コントローラ３７は，運転情報信号，温度検出信号，残蓄氷量検出信号に基づいて，制御信号をバイパス開閉弁Ｖ１，開閉弁Ｖ２，Ｖ３に送信して，バイパス開閉弁Ｖ１，開閉弁Ｖ２，Ｖ３を操作する。この場合，各階の室内の温度と各空調機セットＰの稼働状態に応じて，各空調機セットＰの過冷却停止運転と過冷却運転を個別に自動的に切り替えることができるので，不必要な過冷却運転を行うことがなく，蓄熱槽３０内の蓄熱を有効に利用できる。
【００６８】
例えば，ある空調機セットＰが過冷却停止運転状態であるときに，運転情報信号と温度検出信号により，室内機６が設置された室内の温度が目標値より上昇し，かつ，その室内機６に対応する室外機５がフルロードであることが検出された場合は，その空調機セットＰの冷房能力を増加させる必要があるので，過冷却運転状態にする。即ち，その空調機セットＰが配置された階のコントローラ３７の制御信号によって，その空調機セットＰに対応するバイパス開閉弁Ｖ１を閉じ，かつ，開閉弁Ｖ２，Ｖ３を開く。これにより，熱媒を冷媒冷却用熱交換器８に通過させ，冷媒配管７からの冷媒が熱媒との熱交換により過冷却されるようにする。一方，例えば，室内の温度がほぼ目標値である場合は，冷房能力を増加させる必要は無いので，コントローラ３７から制御信号を送信せず，その空調機セットＰを過冷却停止運転状態に維持する。また，室内の温度が目標値より上昇していても，室外機５がフルロードでない場合は，室外機５をフルロードにすればよいので，その空調機セットＰを過冷却停止運転状態に維持する。そして，ある空調機セットＰが過冷却運転状態であるときに，室内の温度がほぼ目標値である場合や，室外機５がフルロードでない場合は，冷房能力を低減させても良いので，過冷却停止運転状態にする。即ち，コントローラ３７の制御信号によってバイパス開閉弁Ｖ１を開き，かつ，開閉弁Ｖ２，Ｖ３を閉じる。これにより，熱媒をバイパス管１１ｅに通過させ，冷媒を過冷却させず冷媒冷却用熱交換器８を素通りさせる。なお，夜間の蓄熱運転は年間を通じて常に行い，蓄熱した冷熱は昼間に使いきるように操作することが好ましい。こうすることにより，安価な夜間電力を利用して経済性を高めることができる。中間期（春季及び秋季），夏季では，冬季より外気温度が上がるが，冷媒を過冷却することにより，高いＣＯＰで運転できる。
【００６９】
また，熱媒配管１１内の熱媒を室外機５に対して散水するための散水配管を備えても良い。図１９に示すように，各室外機５の近くを通過する熱媒配管１１から，散水配管４０を分岐させ，各室外機５の図示しない吸い込み口の付近にノズル４１を設け，各散水配管４０をノズル４１にそれぞれ接続する。さらに，各散水配管４０を開閉する開閉弁Ｖ４を介設する。また，総ての冷媒冷却用熱交換器８より上流側の熱媒配管１１に，即ち，冷媒冷却用熱交換器８に分岐する位置より上流側に，熱媒配管１１内の熱媒の循環量を制御する開閉弁Ｖ５を介設する。この場合，緊急時に蓄熱槽３０内の熱媒を散水することにより，外気温度を下げることができる。従って，空調機セットＰの冷房能力を直ちに増加させることができる。例えば熱媒冷却機１０が故障して過冷却ができない場合であっても，過冷却停止運転時以上の冷房能力（過冷却運転時の約８０％以上の冷房能力）で運転できる。
【００７０】
本実施の形態では，熱媒冷却機１０を建物１の屋上階ＲＦに配置した構成としたが，熱媒冷却機１０は，建物１の地下階に配置しても良い。また，冷媒冷却用熱交換器における前記冷媒の冷却を地域冷暖房システムを利用して行う構成としても良い。例えば，図２０に示すように，建物１の下の地中に地域冷暖房システムの熱供給配管４３を設置し，熱媒配管１１を熱供給配管４３に接続する。そして，熱供給配管４３から熱媒供給配管１１ａを介して各冷媒冷却用熱交換器８に熱媒を供給し，熱媒によって冷媒を冷却した後，熱媒回収配管１１ｂを介して熱媒を熱供給配管４３に戻す。こうして，地域冷暖房システムと各冷媒冷却用熱交換器８との間で熱媒を循環させ，熱媒を介して地域冷暖房システムの熱源プラントから供給される冷熱によって，各冷媒冷却用熱交換器８にて冷媒を過冷却する。なお，地域冷暖房システムを利用する場合，経済性を高めるためには，中間期（春季及び秋季），冬季では，可能な限り各空調機セットＰの能力で冷房負荷を処理し，地域冷暖房システムからの熱媒の受け入れ量を少なくし，熱料金を抑えることが好ましい。
【００７１】
【発明の効果】
本発明によれば，冷媒を過冷却した分だけ空調機の冷房能力を増加させることができるので，熱負荷の高い施設であっても，空調機セットの設置台数を適正な数にして，ベランダに室外機を適正に配置できる。外気温度を適正な温度に保つことができる。空調機セットを高効率な定格能力で運転できる。室外機の消費電力を減少させることができる。空調機セットのＣＯＰを増加させることができる。さらに，空調設備全体の消費電力と電力料金を削減できる。また，蓄熱運転を夜間に行うことにより，電力需要の平準化ができる。安価な夜間電力を活用することで，空調設備全体の電力料金をさらに削減できる。
【図面の簡単な説明】
【図１】本実施の形態にかかる空調設備の概略を説明する説明図である。
【図２】空調機セットの構成を説明する説明図である。
【図３】空調機セットの冷房能力と外気温度の関係を示した能力線図である。
【図４】空調機セットの消費電力と外気温度の関係を示した能力線図である。
【図５】本発明の空調設備と従来型の空調設備の年間消費電力を示したグラフである。
【図６】本発明の空調設備と従来型の空調設備の年間消費電力を示した表である。
【図７】本発明の空調設備と従来型の空調設備の年間電力料金を示したグラフである。
【図８】本発明の空調設備と従来型の空調設備の年間電力料金を示した表である。
【図９】年間消費電力と年間電力料金の試算に使用した，一日の熱負荷を示したグラフである。
【図１０】年間消費電力と年間電力料金の試算に使用した，年間の熱負荷を示したグラフである。
【図１１】８月の最大負荷日における，本発明の空調設備の消費電力を試算した結果を示したグラフである。
【図１２】８月の最大負荷日における，従来型の空調設備の消費電力を試算した結果を示したグラフである。
【図１３】８月の代表日における，本発明の空調設備の消費電力を試算した結果を示したグラフである。
【図１４】８月の代表日における，従来型の空調設備の消費電力を試算した結果を示したグラフである。
【図１５】１月の代表日における，本発明の空調設備の消費電力を試算した結果を示したグラフである。
【図１６】１月の代表日における，従来型の空調設備の消費電力を試算した結果を示したグラフである。
【図１７】マルチパッケージエアコンの構成を示した説明図である。
【図１８】コントローラによる制御を説明する説明図である。
【図１９】空調機セットに散水配管を備えた場合の説明図である。
【図２０】地域冷暖房システムを利用した，別の実施の形態にかかる空調設備の概略を説明する説明図である。
【符号の説明】
Ｐ空調機セット
ＲＦ屋上階
１建物
２ベランダ
５室外機
６室内機
７冷媒配管
８冷媒冷却用熱交換器
１０熱媒冷却機
１１熱媒配管
１２切換管路
３０蓄熱槽[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for supercooling a refrigerant in an air-cooled individual air conditioning system.
[0002]
[Prior art]
As an individual air conditioning system for a building, an air conditioning system (air conditioning system using a package air conditioner) using an air-cooled air conditioner set including an outdoor unit and an indoor unit connected by refrigerant piping is known. Such an air conditioning system has advantages such as low cost of equipment, space saving, start / stop of air conditioning operation for each room, and selective operation of cooling / heating. Further, by installing the outdoor unit of the air conditioner set on a veranda (balcony) or the like on each floor, there is an advantage that the indoor rentable ratio can be improved. Therefore, it is generally used for tenant buildings and small buildings. It is also used in multi-story buildings with a large cooling load per floor area, such as Internet data centers (communication facilities equipped with a number of "IDC" servers).
[0003]
The outdoor unit of the air conditioner set has a compressor and a condenser connected by piping in the outdoor unit. The indoor unit has an expansion valve and an evaporator connected by piping in the indoor unit. The condenser is connected to an expansion valve and an evaporator. The refrigerant circulates through the compressor, the condenser, the expansion valve, and the evaporator in this order, and the cool air generated around the evaporator. The room is thus cooled.
[0004]
On the other hand, the refrigeration cycle consisting of an air-cooled outdoor heat exchanger (heat exchanger of an outdoor unit acting as a condenser) and an indoor heat exchanger (heat exchanger of an indoor unit acting as an evaporator) saves energy. Alternatively, as a technology to cope with insufficient capacity, a heat exchanger for heat storage is provided between the outdoor heat exchanger and the indoor heat exchanger, and cold heat is stored in the heat medium in the heat storage tank. A configuration in which heat is exchanged between a heat medium and a refrigerant of a refrigeration cycle has been proposed (for example, see Patent Documents 1, 2, and 3). Also, a heat exchanger for cooling the refrigerant acting as an evaporator is provided between the outdoor heat exchanger and the indoor heat exchanger, and this heat exchanger and another heat exchanger acting as a condenser are provided. There has been proposed a configuration in which a second refrigeration cycle including an outdoor unit and another compressor is formed, and the cooling capacity is supplemented by the second refrigeration cycle (for example, see Patent Document 4). According to these configurations, the refrigerant can be supercooled by the cool heat in the heat storage tank, and the cooling capacity for the supercooled portion increases. Therefore, the amount of circulating refrigerant can be reduced, and operation can be performed with the pressure of the compressor reduced. Further, the cooling operation can be performed in a state where the fan of the outdoor unit for passing the air through the outdoor heat exchanger is stopped. That is, by reducing the driving force of the outdoor unit, power consumption can be reduced and cost can be reduced.
[0005]
[Patent Document 1]
JP-A-6-94284 (page 7, FIG. 1)
[Patent Document 2]
JP-A-7-4768 (page 4, FIG. 1)
[Patent Document 3]
JP-A-11-325644 (page 5, FIGS. 1, 7)
[Patent Document 4]
JP-A-10-339512 (page 2, FIG. 1)
[0006]
[Problems to be solved by the invention]
In an air conditioning system using a conventional package air conditioner, it is necessary to increase the number of outdoor units and indoor units as the cooling load per indoor floor area increases. However, as the number of outdoor units increases and the density of the outdoor units installed on the roof floor or on the veranda on each floor increases, the air temperature around the outdoor units rises due to the exhaust of the outdoor units, and the intake air temperature of the outdoor units rises. There was a problem that the cooling capacity was reduced due to the increase. In addition, due to this decrease in cooling capacity, it is necessary to further increase the number of outdoor units to be installed, so that equipment costs are high, and the outdoor units are installed at a higher density and the cooling capacity is further reduced. .
[0007]
Further, when the configurations described in Patent Documents 1 to 4 are used, the cooling capacity can be improved, but a space for installing a heat storage tank, a second refrigeration cycle, a heat storage circulation cycle, and the like on a veranda or the like cannot be secured. There was a problem.
[0008]
Therefore, an object of the present invention is to provide an air conditioner in which air-cooled outdoor units are arranged at a low density and the cooling capacity can be improved.
[0009]
[Means for Solving the Problems]
According to the present invention, there is provided an air conditioner including a plurality of air conditioner sets each including an air-cooled outdoor unit and an indoor unit. An air conditioning system is provided, which is provided with a refrigerant cooling heat exchanger for cooling the refrigerant flowing into the indoor unit with water or brine, and enabling the operation of cooling the refrigerant for each air conditioner set. You. Here, "air conditioner set" refers to a combination of an indoor unit and an outdoor unit connected to the indoor unit by a refrigerant pipe, and refers to a unit that performs a cooling operation. An "airplane" is a device that compresses and condenses a refrigerant, discharges high-temperature exhaust gas into the atmosphere, and causes the refrigerant to absorb cold heat. An "indoor unit" is a device that expands and evaporates a refrigerant and discharges cool air into a room of a building to perform cooling. The air conditioner of the present invention is, for example, an air conditioner dedicated to cooling. According to such an air conditioner, when the air conditioner set is operated for cooling, the cooling capacity of each air conditioner set can be improved by supercooling the refrigerant. Also, even in a building where the cooling load per floor area of one floor is large, the number of air conditioner sets for cooling one floor can be reduced by improving the cooling capacity for each set of air conditioners. be able to. As a result, the outdoor units can be arranged at a low density. In addition, the supercooling operation can be performed independently for each air conditioner set, and the operation mode can be flexibly selected as either the supercooling operation or the supercooling stop operation according to the cooling load provided by each air conditioner set. .
[0010]
Further, if the plurality of outdoor units are arranged on the veranda of the building, the installation space for the outdoor units can be distributed to the verandas on each floor, so that the above-described adverse effects of the high-density arrangement of the outdoor units can be reduced. In addition, the refrigerant pipe length of the refrigerant pipe through which the refrigerant circulating in the air conditioner set flows can be set to an appropriate length, and the cooling capacity does not decrease.
[0011]
Further, it is preferable that the water or the brine is cooled by a cooler arranged on a rooftop floor or a basement floor of a building. The cooling by the cooler is preferably performed through a heat storage tank that stores cold heat. By doing so, it is possible to improve economic efficiency by storing cold heat by using late-night electric power, which is cheap.
[0012]
The refrigerant cooling heat exchanger may be configured to cool the water or brine using a district cooling / heating system.
[0013]
It is preferable that each of the refrigerant cooling heat exchangers is provided with a pipe line that can switch between flow and cutoff of the water or brine to the refrigerant cooling heat exchanger.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described. FIG. 1 is an explanatory diagram schematically showing a configuration of a building 1 provided with an air conditioner according to the present invention. The building 1 has a plurality of levels. On each floor of the building 1, a veranda 2 is provided. Each floor of the building 1 is provided with a plurality of air conditioner sets (air conditioners of air cooling package unit type) P for exclusive use of cooling, which are a combination of one air cooling outdoor unit 5 and one indoor unit 6. Have been. In the example shown in FIG. 1, a plurality of air conditioner sets P provided for each floor of the building 1 are omitted, and one air conditioner set P is shown for each floor.
[0015]
Further, in each air conditioner set P, a pair of outdoor units 5 and indoor units 6 are connected by refrigerant pipes 7. The indoor unit 6 is provided on the ceiling in the room on each floor. The outdoor unit 5 is arranged on an indoor unit 6 connected to the outdoor unit 5 by a refrigerant pipe 7, that is, on the veranda 2 on the floor where the corresponding indoor unit 6 is arranged. Therefore, on the veranda 2, the outdoor units 5 of a plurality of air conditioner sets P for one floor, that is, a plurality of outdoor units 5 are arranged. The refrigerant pipe 7 is composed of a refrigerant liquid pipe 7a for flowing refrigerant from the outdoor unit 5 to the indoor unit 6, and a refrigerant gas pipe 7b for flowing refrigerant from the indoor unit 6 to the outdoor unit 5. I have. Each configuration of the outdoor unit 5 and the indoor unit 6 will be described later in detail.
[0016]
By arranging the outdoor unit 5 and the indoor unit 6 on the same floor, the height difference between the outdoor unit 5 and the indoor unit 6 can be reduced, so that the vertically drawn piping portion of the refrigerant pipe 7 can be shortened. it can. Further, the refrigerant pipe 7 can be formed only of the horizontal drawing pipe. Therefore, the entire length of the refrigerant pipe 7 including the vertically drawn pipe part and the horizontally drawn pipe part can be sufficiently shortened to the maximum refrigerant pipe length or less, the pipe resistance is reduced, and the cooling capacity of the air conditioner set P is reduced. We can secure enough. In addition, the power for supplying the refrigerant can be reduced, thereby saving power and cost. Further, by dispersing the installation space of the outdoor unit 5 on the veranda 2 on each floor, it is possible to mitigate the adverse effect of the high-density arrangement of the outdoor unit 5, that is, an increase in the outside air temperature due to high-temperature exhaust.
[0017]
Further, each air conditioner set P is provided with a refrigerant cooling heat exchanger 8 for cooling the refrigerant in the refrigerant liquid pipe 7a flowing from the outdoor unit 5 toward the indoor unit 6 with a heat medium. Each of the refrigerant cooling heat exchangers 8 is provided in the middle of the corresponding refrigerant liquid pipe 7a. The refrigerant cooling heat exchanger 8 is also connected to the indoor unit 6 to which the refrigerant pipe 7 in which the refrigerant cooling heat exchanger 8 is interposed, that is, to the veranda 2 on the floor where the corresponding indoor unit 6 is arranged. Are located. Therefore, on the veranda 2, in addition to the plurality of outdoor units 5, the refrigerant cooling heat exchangers 8 of the plurality of air conditioner sets P for one floor, that is, the plurality of refrigerant cooling heat exchangers 8 are provided. Are located. The refrigerant cooling heat exchanger 8 is a plate-type heat exchanger and is smaller than the outdoor unit 5, so that even if it is arranged on the veranda 2, it does not hinder the arrangement of the outdoor unit 5. Water or brine is used as the heating medium.
[0018]
On the rooftop floor RF of the building 1, a heat medium cooler 10 for cooling the heat medium is arranged. All the refrigerant cooling heat exchangers 8 arranged on all the verandas 2 of each floor are connected to one heat medium cooler 10 by a heat medium pipe 11 through which a heat medium flows. Further, a pump (not shown) for circulating the heat medium is provided in the heat medium pipe 11, and the pump is also disposed on the rooftop floor RF.
[0019]
The heat medium pipe 11 is provided with a heat medium supply pipe 11 a through which a heat medium flows from the heat medium cooler 10 to the refrigerant heat exchanger 8, and a heat medium supply pipe 11 from the refrigerant heat exchanger 8 to the heat medium cooler 10. And a heat medium recovery pipe 11b through which the refrigerant flows. The heat medium pipes 11 are arranged vertically between the veranda 2 on each floor and the rooftop floor RF, and are arranged horizontally on the veranda 2 on each floor. The heat medium supply pipe 11a branches one by one at the height of each floor, and this branch pipe (not shown) branches one by one into a narrow tube 11c near each heat exchanger 8 for cooling the refrigerant. The thin tubes 11c are disposed so as to be connected to the heat medium inlets of the respective refrigerant cooling heat exchangers 8 so as to divide and supply the heat medium to the respective refrigerant cooling heat exchangers 8. . The heat medium recovery pipe 11b joins the thin tubes 11d one by one connected to the heat medium outlet of each refrigerant cooling heat exchanger 8 one by one in the vicinity of each refrigerant cooling heat exchanger 8. The merging pipes are merged one by one at the height of each floor, and the merging pipes (not shown) are arranged so as to be connected to the heat medium cooler 10, and the heat medium is recovered from each of the refrigerant cooling heat exchangers 8. And return to the heat medium cooler 10.
[0020]
As shown in FIG. 2, in the vicinity of each refrigerant cooling heat exchanger 8, a bypass pipe 11 e of the heat medium pipe 11 is provided in parallel with each refrigerant cooling heat exchanger 8. The upstream end of the bypass pipe 11e is connected in the middle of the thin pipe 11c of the heat medium supply pipe 11a, and the downstream end of the bypass pipe 11e is connected in the middle of the thin pipe 11d of the heat medium recovery pipe 11b.
[0021]
A bypass opening / closing valve V1 is provided in the bypass pipe 11e. An on-off valve V2 is provided downstream of the branch position of the bypass pipe 11e in the thin pipe 11c. An on-off valve V3 is provided in the narrow tube 11c on the upstream side of the junction of the bypass tube 11e. When the bypass on-off valve V1 is closed and the on-off valves V2, V3 are opened, the flow of the heat medium to the bypass pipe 11e is cut off, and the heat medium flows to the refrigerant cooling heat exchanger 8, and the bypass is opened and closed. When the valve V1 is opened and the on-off valves V2 and V3 are closed, the heat medium flows through the bypass pipe 11e, and the flow to the refrigerant cooling heat exchanger 8 is cut off. As described above, the flow of the heat medium to the bypass pipe 11e and the flow of the heat medium to the refrigerant cooling heat exchanger 8 are switched by opening and closing the bypass on-off valve V1, the on-off valves V2, and V3. ing. That is, the bypass pipe 11e having the bypass on-off valve V1, the thin pipe 11c of the heat medium supply pipe 11a having the on-off valve V2, and the thin pipe 11d of the heat medium recovery pipe 11b having the on-off valve V3 are connected to the refrigerant cooling heat exchanger 8. A switching pipe line 12 is formed which can switch between flowing and blocking of the heat medium. The switching pipes 12 are provided so as to correspond to the respective refrigerant cooling heat exchangers 8, and each of the switching pipes 12 is individually switched between flowing and blocking, so that each of the refrigerant cooling heat exchangers is provided. 8 can be individually switched between flowing and blocking the heat medium.
[0022]
The heat medium is cooled in the heat medium cooler 10, passes through the heat medium supply pipe 11a, descends from the rooftop RF toward the refrigerant cooling heat exchangers 8 of the respective verandas 2, and is cooled. Alternatively, after flowing through the bypass pipe 11e, the cooling medium passes through the heat medium recovery pipe 11b, rises toward the heat medium cooler 10 on the rooftop floor RF, and is cooled again in the heat medium cooler 10. When the heat medium to which the cooling medium is given in the heating medium cooler 10 flows through the heat exchanger 8 for cooling the refrigerant, the heat medium exchanges heat with the refrigerant compressed and condensed in the outdoor unit 5, and the cooling medium is given to the cooling medium. Cooled.
[0023]
Next, the refrigeration cycle constituted by the air conditioner set P and the refrigerant cooling heat exchanger 8 will be described in detail. As shown in FIG. 2, the outdoor unit 5 includes an accumulator 13, a compressor 14, a four-way valve 15, and a condenser 16. Further, an outdoor unit flow path 17 through which the refrigerant flows in the order of the four-way valve 15, the accumulator 13, the compressor 14, the four-way valve 15, and the condenser 16 is incorporated. Further, the outdoor unit 5 is provided with a suction port (not shown) for sucking outside air and a hood (not shown) for discharging outside air.
[0024]
The four-way valve 15 has four ports 15a, 15b, 15c, and 15d. The inside of the four-way valve 15 is in a state where the first port 15a and the second port 15b are connected, and the third port 15c and the fourth port 15d are connected. An outdoor unit internal flow path 17 connected to the refrigerant inlet of the indoor unit 6 is connected to the first entrance 15a. An outdoor unit flow path 17 connected to a refrigerant inlet of the accumulator 13 is connected to the second entrance 15b. An outdoor unit flow path 17 connected to a refrigerant outlet of the compressor 14 is connected to the third port 15c. The outdoor unit internal flow path 17 connected to the refrigerant inlet of the condenser 16 is connected to the fourth connection port 15d. The outdoor unit passage 17 connected to the refrigerant outlet of the accumulator 13 is connected to the refrigerant inlet of the compressor 14, and the outdoor unit passage 17 connected to the refrigerant outlet of the condenser 16 is connected to the refrigerant outlet of the indoor unit 6. It is connected.
[0025]
The indoor unit 6 includes an expansion valve 18 and an evaporator 19. Further, a flow path 20 in the indoor unit for allowing the refrigerant to flow in the order of the expansion valve 18 and the evaporator 19 is incorporated.
[0026]
The refrigerant cooling heat exchanger 8 is a plate-type heat exchanger. As shown in FIG. 2, the refrigerant cooling heat exchanger 8 has a built-in refrigerant passage 22 that allows a refrigerant to pass therethrough and an internal heat medium passage 23 that allows a heat medium to pass through.
[0027]
The downstream end of the refrigerant gas pipe 7b is connected to the outdoor unit flow path 17 via a refrigerant inlet of the outdoor unit 5, and the upstream end of the refrigerant liquid pipe 7a is connected to the outdoor unit 5 via a refrigerant outlet of the outdoor unit 5. The upstream side of the refrigerant liquid pipe 7a is connected to the internal refrigerant flow path 22 via the refrigerant inlet of the refrigerant cooling heat exchanger 8, and the refrigerant liquid pipe 7a is connected through the refrigerant outlet of the refrigerant cooling heat exchanger 8. The downstream side is connected. The downstream end of the refrigerant liquid pipe 7a is connected to the indoor unit passage 20 via the refrigerant inlet of the indoor unit 6, and the upstream end of the refrigerant gas pipe 7b is connected to the indoor unit 6 via the refrigerant outlet of the outdoor unit 5. That is, the refrigerant circulation circuit 24 is configured to circulate the refrigerant in the order of the outdoor unit internal flow path 17, the refrigerant liquid pipe 7a, the internal refrigerant flow path 22, the refrigerant liquid pipe 7a, the indoor unit internal flow path 20, and the refrigerant gas pipe 7b. .
[0028]
On the other hand, the downstream end of the heat medium supply pipe 11a (downstream end of the narrow tube 11c) is connected to the internal heat medium passage 23 via the heat medium inlet of the heat exchanger 8 for cooling the refrigerant, and the heat exchange for cooling the refrigerant is performed. The upstream end of the heat medium recovery pipe 11b (the upstream end of the thin tube 11d) is connected via the heat medium outlet of the vessel 8. That is, a heat medium supply circuit 25 that allows the heat medium to flow in the order of the heat medium supply pipe 11a, the internal heat medium flow path 23, and the heat medium recovery pipe 11b is configured.
[0029]
When the air conditioner set P is operated, the refrigerant in the refrigerant circulation circuit 24 circulates in the order of the outdoor unit 5, the refrigerant cooling heat exchanger 8, and the indoor unit 6. That is, the refrigerant sent from the evaporator 19 of the indoor unit 6 to the outdoor unit 5 is sent to the compressor 14 via the four-way valve 15 and the accumulator 13, compressed by the compressor 14 and discharged at high temperature and high pressure. , Is supplied to the condenser 16 through the four-way valve 15, condensed in the condenser 16, passes through the internal refrigerant flow path 22 in the refrigerant cooling heat exchanger 8, and is supplied to the indoor unit 6. The refrigerant supplied to the indoor unit 6 adiabatically expands at the expansion valve 18, evaporates at the evaporator 19, and returns to the outdoor unit 5. Further, when outside air is sucked from a suction port (not shown) of the outdoor unit 5 and the refrigerant absorbs cold heat and condenses in the condenser 16, the outside air becomes high temperature around the condenser 18 and is discharged from a hood (not shown), and is conveyed to the veranda. 2 is exhausted toward the outside. Further, when the refrigerant evaporates in the indoor unit 6, cool air is generated around the evaporator 19, and the cool air is blown by a blower (not shown) provided in the indoor unit 6, and is supplied to the room. Thereby, the indoor air is cooled.
[0030]
When the refrigerant flows through the internal refrigerant passage 22, the bypass opening / closing valve V1 is closed and the opening / closing valves V2 and V3 are opened, so that the heat medium to which the cooling medium is given in the heat medium cooler 10 is cooled by the internal heat. In a state where the heat medium flows through the medium flow path 23, the refrigerant flowing through the internal refrigerant flow path 22 and the heat medium flowing through the internal heat medium flow path 23 in the refrigerant cooling heat exchanger 8. And heat exchange. That is, the heat medium supplied with the cold in the heat medium cooler 10 and sent to the inside heat medium passage 23 and the refrigerant compressed and condensed in the outdoor unit 5 and sent to the inside refrigerant passage 22. The refrigerant is supercooled by heat exchange. As described above, when the refrigerant is supercooled before being expanded and evaporated in the indoor unit 6 after being compressed and condensed in the outdoor unit 5, the cooling of the air conditioner set P is performed by an amount corresponding to the subcooling of the compressed and condensed refrigerant. Ability can be increased. On the other hand, when the refrigerant passes through the in-unit refrigerant flow path 22, by opening the bypass on-off valve V1 and closing the on-off valves V2, V3, the heat medium does not flow through the in-unit heat medium flow path 23. In this state, the refrigerant compressed and condensed in the outdoor unit 5 is supplied to the indoor unit 6 without passing through heat exchange with the heat medium in the refrigerant cooling heat exchanger 8. The operation mode of each air conditioner set P is changed by individually performing the opening and closing operations of the bypass on-off valves V1, the on-off valves V2, and V3 as described above for the switching pipes 12 provided for each air conditioner set P. The operation can be individually switched to one of a supercooling operation for supercooling the refrigerant and a supercooling stop operation for operating without supercooling the refrigerant.
[0031]
As shown in FIG. 1, the heat medium cooling device 10 disposed on the rooftop RF includes a heat medium cooling heat storage device 27 that stores cold heat by storing a frozen heat medium, and a heat medium cooling heat storage device 27. And an ice making refrigerator 28 for giving cold heat to the heat medium therein.
[0032]
The heat storage device 27 for cooling the heat medium is a static type external melting type ice heat storage device. The heat storage device 30 stores the heat medium to store cold heat, and the heat exchanger in the heat storage device provided inside the heat storage device 30. 31. The heat storage tank 30 is arranged on a rooftop floor RF, and an upstream end of the heat medium supply pipe 11a and a downstream end of the heat medium recovery pipe 11b are connected. That is, 270 refrigerant cooling heat exchangers 8 are connected to the heat storage tank 30 of the heat medium cooling heat storage device 25 by the heat medium pipe 11. The above-described heat medium supply circuit 25 circulates the heat medium in the order of the heat storage tank 30, the heat medium supply pipe 11a, the internal heat medium flow path 23, and the heat medium recovery pipe 11b. The heat medium is cooled through the heat storage tank 30 by the heat storage operation of the ice making refrigerator 28.
[0033]
The ice making refrigerator 28 is disposed on the rooftop floor RF and has a built-in refrigerator heat exchanger (not shown). The heat exchanger 31 in the heat storage tank and the heat exchanger in the refrigerator are connected by a heat medium pipe 33 for ice making that allows a heat medium for ice making to flow, and the heat exchanger 31 in the heat storage tank, the heat medium pipe 33 for ice making, An ice making heat medium circulation circuit 34 that circulates the ice making heat medium in the order of the heat exchanger in the refrigerator is configured.
[0034]
Here, a cold heat storage (ice making) operation in the heat medium cooler 10 will be described. The ice-making heat medium cooled in the ice-making refrigerator 28 is sent from the ice-making refrigerator 28 to the ice-making heat exchanger 31 through the ice-making heat medium pipe 33, and the heat medium around the ice-making heat exchanger 31. Then, the heat medium is cooled by heat, and the heat medium is returned to the ice making refrigerator 28 through the ice making heat medium pipe 33 and cooled. In this manner, the cold generated in the ice making refrigerator 28 is supplied to the heat medium in the heat storage tank 30 via the ice making heat medium, and the heat medium is frozen to become ice-like. The heat medium frozen around the ice making heat exchanger 31 is accumulated as ice in the heat storage tank 30. That is, cold heat is stored in the heat storage tank 30 by storing the frozen heat medium. This heat storage (ice making) operation is preferably performed using nighttime electric power with a low electricity rate. In this case, the electricity cost for the operation of the heat medium cooler 10 can be reduced, and, consequently, the electricity cost for the operation of the entire air conditioner can be reduced.
[0035]
The heat medium stored as ice in the heat storage tank 30 exchanges heat with the cold water flowing in the heat medium supply circuit 25 to continuously apply cold to the cold water. Then, the cold water is supplied to each of the refrigerant cooling heat exchangers 8 to provide the refrigerant with cold heat as described above, is again stored in the heat storage tank 30, and is frozen by the heat storage operation.
[0036]
As described above, the refrigerant pipe 7 connecting the outdoor unit 5 and the indoor unit 6 has a maximum refrigerant pipe length that is sufficient to prevent a reduction in suction pressure of the compressor and an increase in pipe resistance and to secure a sufficient cooling capacity. Therefore, the refrigerant circulation circuit 24 is restricted in the distance of heat transport. On the other hand, the heat medium supply circuit 25 is a water circulation system using cold water as the heat medium, and the length of the heat medium pipe 11 is not limited by the pipe length as in the refrigerant pipe 7, and is suitable for long-distance heat transport. ing. Therefore, by arranging the outdoor unit 5 corresponding to the indoor unit 6 on the veranda 2 on the same floor, the refrigerant pipe 7 is shortened as much as possible, and the refrigerant cooling heat exchanger 8 is disposed on the veranda 2 on each floor, and the ice making refrigeration is performed. It is preferable that the length of the heat medium pipe 11 be longer than that of the refrigerant pipe 7 by arranging the heat generator 28 and the heat storage tank 30 on the rooftop floor RF. In this case, the cooling capacity of the air conditioner set P can be sufficiently ensured.
[0037]
For example, when the amount of ice accumulated in the heat storage tank 30 is likely to be insufficient during the supercooling operation, the operation mode of the arbitrary air conditioner set P is switched to the supercooling stop operation. For example, the air conditioner set P whose cooling load to be covered is in a relatively low state is selected, and the operation is switched to the supercooling stop operation. That is, for the selected air conditioner set P, by opening the bypass on-off valve V1 and closing the on-off valves V2, V3, the flow of the heat medium to the refrigerant cooling heat exchanger 8 is cut off, and the heat is supplied to the bypass pipe 11e. The medium is passed, and the refrigerant is passed without supercooling. Further, even if the heat medium pipe 11, the pump provided in the heat medium pipe 11, the heat storage tank 30, and the like fail during the supercooling operation, the supply of the heat medium from the heat medium supply circuit 25 becomes impossible. Then, the operation mode of any air conditioner set P is switched to the supercooling stop operation. By doing so, it is possible to continue the cooling operation by the subcooling stop operation while lowering the cooling capacity than during the supercooling operation. In this manner, the supercooling operation can be performed independently for each air conditioner set P, and each air conditioner set P can be controlled according to the cooling load, the state of the heat storage tank 30 and the heat medium pipe 11, etc. For each machine set P, the operation mode can be flexibly selected as either the subcooling operation or the subcooling stop operation. The cooling capacity of the air conditioner set P in which the operation mode is switched to the supercooling stop operation does not become zero, and the same cooling capacity as in the supercooling stop operation can be maintained. That is, in the air conditioning equipment of the present invention, the redundancy corresponding to the cooling capacity during the supercooling stop operation is secured for the cooling capacity during the supercooling operation.
[0038]
In addition, the air conditioning equipment of the present invention improves the cooling capacity of each set of air conditioners P by the supercooling operation, so that the air conditioning equipment of the present invention has a larger air conditioning equipment set than the conventional air conditioning equipment having no configuration for the supercooling operation. The number of sets of P can be reduced. Thereby, the outdoor unit 5 can be arranged on the veranda 2 at a low density. That is, the outdoor units 5 can be arranged at a sufficient interval from each other so that the outdoor units 5 do not suck each other's exhaust gas. Therefore, there is no fear that the heat exchange capacity of the outdoor unit 5 is reduced due to the suction of the high-temperature exhaust gas and that the operation of the outdoor unit 5 is stopped. The refrigerant cooling heat exchanger 8 is a plate-type heat exchanger, which is smaller than the outdoor unit 5 and can save space. do not become.
[0039]
Next, the effect of the supercooling operation will be described more specifically. The inventor specifically supposes a building in which the air conditioning equipment of the present invention is installed, and the number of air conditioner sets P required for the designed heat load of the assumed building, the cooling capacity required for each air conditioner set P, The power consumption and the like of the air conditioner set P were estimated. In addition, a comparison was made with a case where a conventional air-conditioning system having no refrigerant cooling heat exchanger 8 and no supercooling operation was installed in the assumed building.
[0040]
The assumed building 1 has six floors, and each floor from the first floor to the sixth floor is used as an IDC. The air-conditioning area on each floor from the first floor to the sixth floor of building 1 is about 2500 m each ² It is about. The design heat load per floor area in the air-conditioning area on each floor is about 0.8 kW / m ² It has been established. That is, the design heat load required for each air-conditioning area is about 2000 kW.
[0041]
Since the IDC generates heat at a higher density than a general computer center, the sensible heat load is high. In addition, humans rarely enter and leave the room, and are usually unmanned. When a maintenance person or the like is needed, a small number of people enter the room. Therefore, the amount of water vapor generated from the human body is very small, and the latent heat load is extremely small.
[0042]
On each floor from the first floor to the sixth floor of the building 1, 45 air-conditioning air-conditioner sets (air-cooling package unit type air conditioners) P each including one air-cooled outdoor unit 5 and one indoor unit 6 are provided. Are provided one by one. In the entire building 1, 45 sets × 6 floors = 270 sets of air conditioner sets P are provided. Therefore, on the veranda 2, in addition to the 45 outdoor units 5, the refrigerant cooling heat exchangers 8 of the 45 air conditioner sets P for one floor, that is, 45 refrigerant cooling heat exchangers 8. Be placed. A total of 270 refrigerant cooling heat exchangers 8 arranged on all the verandas 2 from the first floor to the sixth floor are connected to a heat storage tank of a heat medium cooler 10 by a heat medium pipe 11 through which a heat medium flows. 30. The capacity of the heat storage tank 30 is about 271 m ³ And the IPF (ice filling ratio) is about 40%. The rated capacity of the ice making refrigerator 28 is about 971 kW (276 Rt), and the COP (coefficient of performance) is about 2.00.
[0043]
The rated capacity of each air conditioner set P (the cooling capacity when the outside air temperature around the outdoor unit 5 (the temperature of the air taken into the outdoor unit 5) is 35 ° C.) is about 37.5 kW in the supercooling stop operation. Approximately 45 kW in the supercooling operation. The design heat load of about 2000 kW required for each air-conditioning area on each floor can be covered by the supercooling operation for the P45 air conditioner sets. In addition, the cooling capacity of each air conditioner set P during the supercooling operation is improved by about 20% as compared with that during the supercooling stop operation. In other words, even if the heating medium pipe 11, the pump provided in the heating medium pipe 11, the heat storage tank 30, and the like break down during the supercooling operation, the supply of the heating medium in the heating medium supply circuit 25 becomes impossible. Thus, the cooling capacity of the air conditioner does not become zero, and it can be said that the same cooling capacity as in the supercooling stop operation, that is, about 80% of the supercooling operation can be maintained. That is, about 80% of the redundancy of the cooling capacity during the supercooling operation of the air conditioner is secured.
[0044]
The power consumption of each outdoor unit 5 required by driving the compressor 16 and the like during the operation at the rated capacity is about 14.2 kW in both the supercooling stop operation and the supercooling operation. The COP of each air conditioner set P is about 2.64 during the supercooling stop operation at the rated capacity, and about 3.17 during the supercooling operation at the rated capacity.
[0045]
In the case of a conventional air conditioner, the rated capacity of each air conditioner set P remains about 37.5 kW, which is the same as that in the above-mentioned supercooling stop operation, and the designed heat load required for each air conditioning area on each floor is about 2000 kW. To cover, it is necessary to provide 45 or more air conditioner sets P for one floor. However, the outdoor unit 5 cannot be arranged with a sufficient interval on the veranda 2, and the high-temperature exhaust of the outdoor unit 5 may increase the outside air temperature to 35 ° C. or more. In this case, each air conditioner set P cannot be operated at the rated capacity, and the cooling capacity decreases to 37.5 kW or less. Therefore, it is necessary to further increase the air conditioner sets P in consideration of the decrease in the cooling capacity. In addition, by increasing the driving force of the compressor 16 to increase the amount of circulating refrigerant, the power consumption of the outdoor unit 5 may increase.
[0046]
On the other hand, in the case of the air conditioner of the present invention, the 45 outdoor units 5 can be arranged on the veranda 2 at a low density so as not to suck each other's exhaust gas. In both the supercooling stop operation and the supercooling operation, the outside air temperature can be prevented from reaching about 35 ° C. or more. Therefore, in both the supercooling stop operation and the supercooling operation, the operation can be performed with the cooling capacity exceeding the rated capacity.
[0047]
When the conventional air conditioning equipment is provided in the building 1, the inventor has determined the number of air conditioner sets P required to cover the design heat load of about 2000 kW on each floor, the outside air temperature around the outdoor unit 5, The cooling capacity of the unit set P and the power consumption of each outdoor unit 5 were estimated. As a result, the number of air conditioner sets P required for each floor of the building 1 is 56 sets, and the required number of air conditioner sets P is 56 sets × 6 floors = 336 sets in the entire 6-story building 1. is there. At this time, the outside air temperature (the intake air temperature of the outdoor units 5) around the 56 outdoor units 5 arranged on each veranda 2 rises to about 40 ° C. by the exhaust of each outdoor unit 5.
[0048]
Here, the capacity diagram used for the trial calculation of the cooling capacity of each air conditioner set P and the power consumption of each outdoor unit 5 will be described. FIG. 3 is a performance diagram showing the relationship between the cooling capacity of the single air conditioner set P and the outside air temperature. FIG. 4 is a performance diagram showing the relationship between the power consumption of a single air conditioner set P and the outside air temperature. In FIG. 3, the horizontal axis indicates the outside air temperature (° C.), and the vertical axis indicates the cooling capacity (kW). In FIG. 4, the horizontal axis represents the outside air temperature (° C.), and the vertical axis represents the power consumption (kW).
[0049]
When the outside air temperature is about 40 ° C., the cooling capacity of each air conditioner set P is about 36.0 kW, as understood from the performance diagram of FIG. 3, and can be understood from the performance diagram of FIG. In addition, the power consumption of each outdoor unit 5 is about 15.1 kW. Further, it is clear from experience that the outside air temperature may rise to about 43 ° C. When the outside air temperature is about 43 ° C., as can be understood from the performance diagram of FIG. 3, the cooling capacity of each air conditioner set P decreases to about 35.4 kW. In the interim period (spring and autumn) and winter, the outside air temperature is lower than in summer, so that power can be saved more (COP is improved) than in summer.
[0050]
Further, when the conventional air conditioning equipment is provided in the building 1, the COP of each air conditioner set P is about 2.38.
[0051]
That is, according to the estimation of the inventor, by applying the air conditioner of the present invention, the number of air conditioner sets P required for each floor of the building 1 is reduced by 11 sets compared to the conventional air conditioner (about 11 sets). 20%). Accordingly, the number of the outdoor units 5 and the number of the heat exchangers 8 for cooling the refrigerant arranged on each veranda 2 can be reduced by 11 units, and the interval between them can be increased. Further, the outside air temperature can be reduced by about 4 ° C. The cooling capacity of each air conditioner set P can be increased by about 1.5 kW (about 4%) during the supercooling stop operation. The power consumption of each outdoor unit 5 can be reduced by about 0.9 kW (about 6%). The COP of each air conditioner set P can be increased by about 0.26 (about 10%).
[0052]
In addition, the inventor estimated the annual power consumption and the annual power rate required for the air conditioner when the air conditioner according to the present invention was provided in the building 1 and when the conventional air conditioner was provided. FIG. 5 is a graph showing the annual power consumption of the air conditioner of the present invention and the conventional air conditioner. FIG. 6 is a table comparing the annual power consumption of the air conditioner of the present invention and the conventional air conditioner. . FIG. 7 is a graph showing the annual power rates of the air conditioner of the present invention and the conventional air conditioner. FIG. 8 is a table comparing the annual power consumption of the air conditioner of the present invention and the conventional air conditioner. . In FIG. 5, the vertical axis indicates the annual power consumption (kW) of the entire air conditioner, the graph bar a indicates the annual power consumption of the air conditioner of the present invention, and the graph bar b indicates the annual power consumption of the conventional air conditioner. Is shown. In FIG. 7, the vertical axis indicates the annual power rate (10,000 yen) of the entire air conditioner, the graph bar c indicates the annual power rate of the air conditioner of the present invention, and the graph bar d indicates the annual power rate of the conventional air conditioner. Indicates the charge.
[0053]
Here, FIGS. 9 and 10 show the heat load shapes assumed in the trial calculation of the annual power consumption and the annual power rate shown in the graphs and tables of FIGS. FIG. 9 is a graph showing assumed daily heat loads. FIG. 10 is a graph showing the assumed annual heat load. In FIG. 9, the horizontal axis indicates the time of the day, and the vertical axis indicates the ratio (%) of the heat load to the total heat load per day. In FIG. 10, the horizontal axis indicates the number of months, and the vertical axis indicates the ratio (%) of the heat load to the total heat load for one year. As shown in FIG. 9, the temporal fluctuation of the heat load per day is assumed to be 70% to 100% in consideration of the fluctuation of the outside air temperature due to the fluctuation of the air temperature. Further, as shown in FIG. 10, the seasonal variation of the heat load for one year is assumed to be 80% to 100% in consideration of the variation of the outside air temperature due to the variation of the temperature.
[0054]
As can be understood from the graphs and tables shown in FIGS. 5 and 6, the air conditioner of the present invention can reduce the annual power consumption to about 94% of the conventional air conditioner. Further, as can be understood from the graphs and tables shown in FIGS. 7 and 8, the air conditioner of the present invention can reduce the annual electricity charge to about 92% of the conventional air conditioner.
[0055]
Furthermore, the inventor compared the facility cost (initial cost) and the electricity rate (running cost) between the case where the air conditioning equipment of the present invention was provided in the building 1 and the case where the conventional air conditioning equipment was provided. The equipment cost required for the air conditioning equipment of the present invention is about 110.4 million yen higher than the equipment cost of the heat medium supply circuit 3 as compared with the conventional air conditioning equipment. On the other hand, since the air conditioner of the present invention has 66 air conditioner sets P less than the conventional air conditioner, if the equipment cost of a single air conditioner set P is about 800,000 yen, it can be reduced by about 52.8 million yen. . Therefore, the equipment cost of the air conditioner of the present invention is increased by about 57.6 million yen compared to the conventional air conditioner. However, the air conditioner of the present invention can reduce the power consumption as compared with the conventional air conditioner as described above, and as can be understood from the graphs and tables shown in FIGS. Fees can be reduced. Therefore, the increase in the equipment cost of the air conditioning equipment of the present invention can be recovered in about two years by reducing the electricity bill. After the equipment cost is recovered, that is, about two years after the installation of the air conditioner of the present invention, the electricity rate can be kept low. Therefore, when comparing the total cost including the equipment cost and all the electricity charges after the installation of the air conditioning equipment, it is understood that the air conditioning equipment of the present invention can be more economical than the conventional air conditioning equipment.
[0056]
Further, the present inventor calculates the power consumption on the maximum load day in August (the maximum load day in the year), the representative day in August (summer representative day) and the representative day in January (representative winter day) in the present invention. Estimates were made for each type of air conditioning equipment and conventional air conditioning equipment. FIG. 11 is a graph showing the results of trial calculation of the power consumption of the air conditioner of the present invention on the maximum load day in August. FIG. 12 is a graph showing the results of trial calculation of the power consumption of the conventional air conditioner on the maximum load day in August. FIG. 13 is a graph showing the results of trial calculation of the power consumption of the air conditioner of the present invention on a representative day in August. FIG. 14 is a graph showing the results of a trial calculation of the power consumption of a conventional air conditioner on a representative day in August. FIG. 15 is a graph showing the results of trial calculation of the power consumption of the air conditioner of the present invention on a representative day in January. FIG. 16 is a graph showing a result of trial calculation of power consumption of a conventional air conditioner on a representative day in January. In FIGS. 11 to 16, the horizontal axis indicates the time of day, and the vertical axis indicates the power consumption (kW) of the entire air conditioner. 11, 13, and 15, a graph bar e indicates the power consumption required for the heat storage operation of the heat medium cooler 10, and a graph bar f indicates the power consumption required for the supercooling operation.
[0057]
From the graphs of FIGS. 11 to 16, it can be seen that the air conditioner of the present invention can level the power demand. In particular, as understood from the graph of FIG. 13, on the representative day of August, the heat storage operation of the heat medium cooler 10 may be performed only at night, and the night shift of electric power is realized. As understood from the graph of FIG. 15, on the representative day of January, the heat storage operation of the heat medium cooler 10 may be performed only for about four hours at night.
[0058]
According to the air conditioning equipment of the present invention, the refrigerant is supercooled by the heat medium supply circuit 3, and the cooling capacity of the air conditioner set P can be increased by the amount of the supercooled refrigerant. Even in a facility with a high load, the number of air conditioner sets P installed can be reduced to an appropriate number. In this case, the number of the outdoor units 5 and the refrigerant cooling heat exchangers 8 arranged on each veranda 2 is reduced. Since it can be arranged, the outside air temperature can be kept at an appropriate temperature. Therefore, the cooling capacity of each air conditioner set P is not impaired, and high-efficiency rated capacity operation is possible. Thereby, the power consumption of each outdoor unit 5 can be reduced, and the COP of each air conditioner set P can be increased.
[0059]
In addition, the power consumption and power charges of the entire air conditioning system can be reduced. By reducing the electricity bill, the increase in the facility bill can be recovered, and the entire bill including the facility bill and all electricity bills after installing the air conditioner can be reduced.
[0060]
Further, by performing the heat storage operation at night, the power can be shifted at night, and the power demand can be leveled. By using inexpensive nighttime power, it is possible to further reduce the power rate of the entire air conditioning system.
[0061]
As described above, an example of a preferred embodiment of the present invention has been described. However, it is needless to say that the present invention is not limited to the above-described embodiment, and can be appropriately modified and implemented. The air conditioner of the present invention is also effective when applied to, for example, department stores and office buildings, in addition to the building 1 as the IDC shown in the embodiment. Further, the central type air conditioner and the air conditioner of the present invention may be combined and installed in a building. Also in this case, the capacity of the entire air conditioning system of the building can be increased, and power can be saved.
[0062]
In the present embodiment, the outdoor unit 5 corresponding to the indoor unit 6 is arranged on the veranda 2 on the same floor. However, if the restriction on the refrigerant pipe length is satisfied, the outdoor unit 5 is connected to the veranda 2 on another floor, It can also be placed on the rooftop RF.
[0063]
Although the building 1 has six floors, it is needless to say that the number of floors may be other than six. Due to the increase in the number of floors, even if the distance between the heat medium cooler 10 on the rooftop RF and the refrigerant cooling heat exchanger 8 on the first floor becomes large, the heat medium pipe 11 can carry long-distance cold heat. Therefore, the supercooling of the refrigerant can be sufficiently performed from the air conditioner set P on the top floor to the air conditioner set P on the first floor.
[0064]
In the present embodiment, the air conditioner set P including one outdoor unit 5 and one indoor unit 6 has been described. However, the air conditioner set is, for example, a plurality of indoor units each having a smaller number of indoor units than the number of indoor units. It may be a multi-package air conditioner connected to an outdoor unit, or a multi for a building. For example, as shown in FIG. 17, in the case of a multi-package air conditioner P ′ in which two indoor units 6a and 6b are connected to one outdoor unit 5, the refrigerant liquid pipe 7a is connected downstream of the refrigerant cooling heat exchanger 8. Then, the indoor unit 6a is connected to one branch pipe, and the indoor unit 6b is connected to the other branch pipe. Further, the upstream side of the refrigerant gas pipe 7b is branched into two, the refrigerant outlet of the indoor unit 6a is connected to one branch pipe, and the refrigerant outlet of the indoor unit 6b is connected to the other branch pipe. That is, a refrigerant circuit in which the refrigerant liquid pipe 7a, the indoor unit pipe 20a provided in the indoor unit 6a, the refrigerant gas pipe 7b, and the outdoor unit pipe 17 are connected in this order, and the refrigerant liquid pipe 7a and the indoor unit provided in the indoor unit 6b A pipe 20b and a refrigerant circuit in which the refrigerant gas pipe 7b and the indoor unit pipe 17 are connected in this order are configured. By super-cooling the compressed and condensed refrigerant branched and sent to the indoor units 6a and 6b in the refrigerant cooling heat exchanger 8, the cooling capacity of the entire multi-package air conditioner P 'can be improved.
[0065]
The air conditioner set P may be dedicated to cooling, or may be configured to be capable of performing a heating operation in addition to the cooling operation, such as a heat pump type package air conditioner. For example, in FIG. 2, the condenser 16 in the outdoor unit 5 is configured as a heat exchanger that functions as a condenser during the cooling operation and functions as an evaporator during the heating operation. Further, the evaporator 19 in the indoor unit 6 is configured as a heat exchanger that functions as an evaporator during the cooling operation and functions as a condenser during the heating operation. The four-way valve 15 connects the first connection port 15a and the second connection port 15b during the cooling operation, and connects the third connection port 15c and the fourth connection port 15d during the cooling operation. The switching operation is performed so that the first connection port 15a and the fourth connection port 15d are connected, and the second connection port 15b and the third connection port 15c are connected. Further, the indoor unit 6 is provided with an expansion valve (not shown) for expanding the refrigerant flowing to the evaporator 19 during the cooling operation. During the cooling operation, the heat exchanger (evaporator 19) in the indoor unit 6, the four-way valve 15, the accumulator 13, the compressor 14, the four-way valve 15, the heat exchanger (condenser 16) in the outdoor unit 5, and the expansion valve 18 The refrigerant is circulated in the order of the heat exchanger (evaporator 19) in the indoor unit 6. On the other hand, by switching the four-way valve 15, the heat exchanger acting as a condenser in the indoor unit 6, the expansion valve 18, the heat exchanger acting as an evaporator in the outdoor unit 5, the four-way valve 15, the accumulator 13, the compressor The refrigerant can be circulated in the order of 14, the four-way valve 15, and the heat exchanger acting as a condenser in the indoor unit 6. In this case, when the refrigerant absorbs cold heat and condenses in the heat exchanger in the indoor unit 6, warm air is generated around the heat exchanger in the indoor unit 6, and the blower (not shown) provided in the indoor unit 6 Thereby, warm air is blown and supplied to the room, thereby heating the room. The present invention can be preferably implemented when the air conditioner sets P are operated in the cooling mode, even in the air conditioning equipment including the air conditioner set P configured to perform the cooling operation and the heating operation.
[0066]
As the heat medium, in addition to the cold water described in the present embodiment, a CFC-based refrigerant, CO 2 ₂ (Carbon dioxide), ammonia-based refrigerant, and ice slurry can also be used. Further, the heat storage device 25 for cooling the heat medium has been described as a static type external melting type ice storage device, but it is needless to say that various other heat storage devices may be used. For example, an external fusion type or an internal fusion type may be used, and a dynamic type heat storage device may be used.
[0067]
Further, the passage of the heat medium through the refrigerant cooling heat exchanger 8 may be controlled by a controller. For example, as shown in FIG. 18, a controller 37 is provided on each of the first to sixth floors. Each outdoor unit 5 is provided with a sensor (not shown) for detecting the operation state of each outdoor unit 5 (the operation state of the compressor 16), and the outdoor unit 5 provided with the sensor is provided with an operation information signal of the sensor. It is configured to transmit to the floor controller 37. Further, a temperature sensor (not shown) for measuring the indoor temperature is provided inside the indoor unit 6, and a temperature detection signal of the temperature sensor is transmitted to the controller 37 on the floor where the indoor unit 6 provided with the temperature sensor is arranged. The configuration is as follows. Further, the heat storage tank 30 is provided with an ice storage amount sensor (not shown) for detecting the amount of ice stored in the heat storage tank 30, and the remaining ice storage amount detection signal from the ice storage amount sensor is transmitted from the first floor to the sixth floor. It is configured to transmit to the controller 37 of each floor up to. The controller 37 transmits a control signal to the bypass on-off valves V1, V2, and V3 based on the operation information signal, the temperature detection signal, and the residual ice storage amount detection signal, and the bypass on-off valves V1, V2, and V3. To operate. In this case, the supercooling stop operation and the supercooling operation of each air conditioner set P can be automatically switched individually in accordance with the indoor temperature of each floor and the operating state of each air conditioner set P, which is unnecessary. The heat storage in the heat storage tank 30 can be used effectively without performing the supercooling operation.
[0068]
For example, when a certain air conditioner set P is in the supercooling stop operation state, the temperature of the room in which the indoor unit 6 is installed rises from a target value by the operation information signal and the temperature detection signal, and the indoor unit 6 When it is detected that the outdoor unit 5 corresponding to the air conditioner is full load, the cooling capacity of the air conditioner set P needs to be increased, so that the supercooling operation state is set. That is, the bypass on-off valve V1 corresponding to the air conditioner set P is closed and the on-off valves V2, V3 are opened in accordance with the control signal of the controller 37 on the floor where the air conditioner set P is arranged. This allows the heat medium to pass through the refrigerant cooling heat exchanger 8 so that the refrigerant from the refrigerant pipe 7 is supercooled by heat exchange with the heat medium. On the other hand, for example, when the indoor temperature is almost the target value, there is no need to increase the cooling capacity, so that the control signal is not transmitted from the controller 37 and the air conditioner set P is maintained in the supercooling stop operation state. . Even if the indoor temperature is higher than the target value, if the outdoor unit 5 is not at full load, the outdoor unit 5 may be set to full load, and the air conditioner set P is maintained in the supercooling stop operation state. I do. When a certain air conditioner set P is in the supercooling operation state and the indoor temperature is almost at the target value or when the outdoor unit 5 is not at full load, the cooling capacity may be reduced. Set to the cooling stop operation state. That is, the bypass on-off valve V1 is opened and the on-off valves V2, V3 are closed by the control signal of the controller 37. This allows the heat medium to pass through the bypass pipe 11e and pass through the refrigerant cooling heat exchanger 8 without supercooling the refrigerant. In addition, it is preferable that the heat storage operation at night is always performed throughout the year, and the stored cold heat is used up during the day. By doing so, economical efficiency can be improved by using inexpensive nighttime power. In the middle period (spring and autumn) and in the summer, the outside air temperature is higher than in the winter, but the operation can be performed at a high COP by supercooling the refrigerant.
[0069]
Further, a water spray pipe for spraying the heat medium in the heat medium pipe 11 to the outdoor unit 5 may be provided. As shown in FIG. 19, a sprinkling pipe 40 is branched from a heat medium pipe 11 passing near each outdoor unit 5, and a nozzle 41 is provided near a suction port (not shown) of each outdoor unit 5. Are connected to the nozzles 41, respectively. Further, an on-off valve V4 for opening and closing each watering pipe 40 is provided. Further, the circulation of the heat medium in the heat medium pipe 11 is performed on the heat medium pipe 11 upstream of all the heat exchangers 8 for cooling the refrigerant, that is, on the upstream side of the position where the heat exchanger 8 branches off. An on-off valve V5 for controlling the amount is provided. In this case, the temperature of the outside air can be reduced by spraying the heat medium in the heat storage tank 30 in an emergency. Therefore, the cooling capacity of the air conditioner set P can be immediately increased. For example, even in the case where the heat medium cooler 10 fails and cannot be supercooled, the operation can be performed with the cooling capacity higher than the supercooling stop operation (about 80% or more of the supercooling operation).
[0070]
In this embodiment, the heat medium cooler 10 is arranged on the rooftop floor RF of the building 1, but the heat medium cooler 10 may be arranged on the basement floor of the building 1. Further, the cooling of the refrigerant in the refrigerant cooling heat exchanger may be performed by utilizing a district cooling / heating system. For example, as shown in FIG. 20, a heat supply pipe 43 of a district cooling / heating system is installed in the ground under the building 1, and the heat medium pipe 11 is connected to the heat supply pipe 43. Then, a heat medium is supplied from the heat supply pipe 43 to each of the refrigerant cooling heat exchangers 8 via the heat medium supply pipe 11a, and after the refrigerant is cooled by the heat medium, the heat medium is cooled via the heat medium recovery pipe 11b. Return to the heat supply pipe 43. Thus, the heat medium is circulated between the district cooling / heating system and each refrigerant cooling heat exchanger 8, and the cooling medium supplied from the heat source plant of the district cooling / heating system via the heating medium causes each refrigerant cooling heat exchanger 8. To supercool the refrigerant. When using the district heating and cooling system, in order to improve the economic efficiency, in the interim period (spring and autumn) and in winter, the cooling load is processed by the capacity of each air conditioner set P as much as possible. It is preferable to reduce the amount of heat medium to be received and to reduce the heat charge.
[0071]
【The invention's effect】
According to the present invention, the cooling capacity of the air conditioner can be increased by an amount corresponding to the supercooling of the refrigerant. The outdoor unit can be properly arranged in the room. The outside air temperature can be kept at an appropriate temperature. The air conditioner set can be operated at a highly efficient rated capacity. The power consumption of the outdoor unit can be reduced. The COP of the air conditioner set can be increased. In addition, the power consumption and power charges of the entire air conditioning system can be reduced. In addition, by performing the heat storage operation at night, power demand can be leveled. By using inexpensive nighttime power, it is possible to further reduce the power rate of the entire air conditioning system.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram illustrating an outline of an air conditioner according to the present embodiment.
FIG. 2 is an explanatory diagram illustrating a configuration of an air conditioner set.
FIG. 3 is a performance diagram showing a relationship between a cooling capacity of an air conditioner set and an outside air temperature.
FIG. 4 is a performance diagram showing a relationship between the power consumption of the air conditioner set and the outside air temperature.
FIG. 5 is a graph showing annual power consumption of the air conditioner of the present invention and a conventional air conditioner.
FIG. 6 is a table showing annual power consumption of the air conditioner of the present invention and a conventional air conditioner.
FIG. 7 is a graph showing annual power rates of the air conditioner of the present invention and a conventional air conditioner.
FIG. 8 is a table showing annual power rates of the air conditioner of the present invention and conventional air conditioners.
FIG. 9 is a graph showing the daily heat load used for calculating the annual power consumption and the annual power rate.
FIG. 10 is a graph showing the annual heat load used for the trial calculation of the annual power consumption and the annual power rate.
FIG. 11 is a graph showing the results of trial calculation of the power consumption of the air conditioner of the present invention on the maximum load day in August.
FIG. 12 is a graph showing results of trial calculation of power consumption of a conventional air conditioner on a maximum load day in August.
FIG. 13 is a graph showing the results of trial calculation of the power consumption of the air conditioner of the present invention on a representative day in August.
FIG. 14 is a graph showing a result of trial calculation of power consumption of a conventional air conditioner on a representative day in August.
FIG. 15 is a graph showing the results of trial calculation of the power consumption of the air conditioner of the present invention on a representative day in January.
FIG. 16 is a graph showing results of trial calculation of power consumption of a conventional air conditioner on a representative day in January.
FIG. 17 is an explanatory diagram showing a configuration of a multi-package air conditioner.
FIG. 18 is an explanatory diagram illustrating control by a controller.
FIG. 19 is an explanatory diagram in a case where a watering pipe is provided in the air conditioner set.
FIG. 20 is an explanatory diagram illustrating an outline of an air conditioner according to another embodiment using a district cooling / heating system.
[Explanation of symbols]
P air conditioner set
RF rooftop floor
1 building
2 veranda
5 outdoor units
6 indoor units
7 Refrigerant piping
8 Refrigerant cooling heat exchanger
10. Heat medium cooler
11 Heat medium piping
12 switching pipeline
30 thermal storage tank

Claims

An air conditioner equipped with a plurality of air conditioner sets each including an air-cooled outdoor unit and an indoor unit,
Each of the plurality of air conditioner sets is provided with a refrigerant cooling heat exchanger for cooling the refrigerant flowing from the outdoor unit to the indoor unit with water or brine, thereby enabling the operation of cooling the refrigerant for each air conditioner set. Air-conditioning equipment.

The air conditioner according to claim 1, wherein the plurality of outdoor units are arranged on a veranda of a building.

The air conditioner according to claim 1 or 2, wherein the water or the brine is cooled by a cooler arranged on a rooftop floor or a basement floor of a building.

The air conditioner according to claim 3, wherein the cooling by the cooler is performed through a heat storage tank that stores cold heat.

The air conditioner according to claim 1, wherein the water or the brine is cooled using a district cooling / heating system in the heat exchanger for cooling the refrigerant. 4.

6. The refrigerant cooling heat exchanger according to any one of claims 1 to 5, further comprising a pipe for switching the flow of water or brine to and from the refrigerant cooling heat exchanger. Air conditioning equipment as described.