JP2004060960A

JP2004060960A - Latent heat storage system

Info

Publication number: JP2004060960A
Application number: JP2002218069A
Authority: JP
Inventors: Tsuneo Takagi; 高木　恒雄; Seiji Isokane; 磯兼　誠司; Tetsuo Fujioka; 藤岡　哲夫; Tadamasu Funasato; 舟里　忠益; Masanobu Hinohara; 日野原　昌信; Kiyokazu Nakamura; 中村　清和
Original assignee: Taikisha Ltd; Chugoku Electric Power Co Inc
Current assignee: Taikisha Ltd; Chugoku Electric Power Co Inc
Priority date: 2002-07-26
Filing date: 2002-07-26
Publication date: 2004-02-26

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the time required for storing heat in latent heat storage and obtain a large amount of the heat storage. <P>SOLUTION: In this latent heat storage system, a heat storage tank 1, which stores cold heat or hot heat in the tank by heat storage operation which cools or heats a heating medium liquid W in the tank taken out of one end of the tank and returns the liquid from the other end of the tank into the tank, is provided, and heat storage containers 9 containing latent heat storage materials X are placed in the heat storage tank 1 with the containers immersed in the heating medium liquid W in the tank. The heat storage tank 1 is formed into a thermal stratification type heat storage tank which forms thermal stratification of the heating medium liquid W in the tank by the heat storage operation. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は潜熱蓄熱システムに関し、詳しくは、槽一端部から取り出した槽内の熱媒液を熱源装置で冷却又は加熱して槽他端部から槽内に戻す蓄熱運転により槽内に冷熱又は温熱を蓄熱する蓄熱槽を設け、潜熱蓄熱材を収容した蓄熱容器を槽内の熱媒液に浸漬させる状態で前記蓄熱槽の槽内に設置してある潜熱蓄熱システムに関する。
【０００２】
【従来の技術】
従来、上記の如き潜熱蓄熱システムでは、潜熱蓄熱材を収容した蓄熱容器を蓄熱槽の槽内に設置してシステムを構築するのに、その蓄熱槽を、蓄熱運転などの槽運転において槽内の熱媒液を槽内のほぼ全域にわたる熱媒液混合を伴う流動形態で槽内流動させる混合式の蓄熱槽にしていた。
【０００３】
【発明が解決しようとする課題】
しかし、この従来の潜熱蓄熱システムでは、槽一端部から取り出した槽内の熱媒液を熱源装置で冷却して槽他端部から槽内に戻す冷熱蓄熱の蓄熱運転の場合、次の如く蓄熱が進行する。
【０００４】
蓄熱運転の開始後、熱媒液の槽内流動に伴う槽内全域にわたっての熱媒液混合のため、熱源装置（冷凍機）からの冷却熱媒液（例えば４℃）の戻りに伴い、図６に示す如く、蓄熱槽における槽内の熱媒液温度ｔが潜熱蓄熱材の温度低下を伴いながら槽内全域について均一に低下していき、この温度低下において潜熱蓄熱材が相変化温度ｔｍ（例えば６〜７℃）に至ると、槽内の全域について潜熱蓄熱材の相変化が始まり、その槽内全域についての潜熱蓄熱材の相変化に大量の冷熱を要する為、その後、熱源装置からの冷却熱媒液の戻りにかかわらず、槽内の熱媒液温度ｔが槽内全域について潜熱蓄熱材の相変化温度ｔｍに近い温度に均一に保たれた状態で潜熱蓄熱材の相変化が進む。
【０００５】
そして、蓄熱容器中における潜熱蓄熱材の相変化がある程度まで進むと、熱媒液と潜熱蓄熱材との間での熱交換効率の低下の為、熱媒液の槽内流動に伴う槽内全域にわたっての熱媒液混合の下で、熱源装置からの冷却熱媒液の戻りに伴い槽内の熱媒液温度ｔが槽内全域について再び均一に低下し始める。
【０００６】
つまり、従来の潜熱蓄熱システムでは、槽内の熱媒液温度ｔが槽内全域について潜熱蓄熱材の相変化温度ｔｍに近い温度に保たれた状態（すなわち、槽内全域について槽内熱媒液と潜熱蓄熱材との温度差が小さいままの状態）で潜熱蓄熱材の相変化が進められるため、熱媒液と潜熱蓄熱材との温度差が重要な決定要因となる潜熱蓄熱材の相変化速度が小さなものに制限されてしまい、この為、潜熱蓄熱材の相変化による蓄熱に長時間を要する問題があった。
【０００７】
また、上記の如く蓄熱運転の開始後、槽内の熱媒液温度ｔが槽内全域について均一に低下していくため、蓄熱槽から熱源装置に送る熱媒液の温度も蓄熱運転の開始後から槽内における熱媒液温度ｔの低下と同調的に低下していく形態になって、熱源装置に送る熱媒液が蓄熱運転の開始後における早い時期に低温化し、この為、蓄熱運転の開始後における早い時期から熱源装置が部分負荷運転の状態になって熱源装置での単位時間当たりの冷却量（換言すれば、単位時間当たりの冷熱蓄熱量）が小さなものに制限されてしまい、このことからも蓄熱に要する時間が長くなる問題があった。
【０００８】
しかも、従来の潜熱蓄熱システムでは、前記の如く潜熱蓄熱材の相変化がある程度まで進むと槽内の熱媒液温度ｔが槽内全域について均一な状態で再び低下し始めるため、蓄熱槽から熱源装置に送る熱媒液の温度が槽内における熱媒液温度の低下と同調的に低下することにおいて潜熱蓄熱材の相変化が未だ完全には完了していない時点で熱源装置の運転下限温度ｔｓに至って熱源装置が停止すると、蓄熱槽の槽内全域について潜熱蓄熱材の相変化が未だ完全に完了していない状態で蓄熱運転の終了に至ってしまい、このことで蓄熱量が小さなものに制限されてしまう問題もあった。
【０００９】
なお、従来の潜熱蓄熱システムでは、槽一端部から取り出した槽内の熱媒液を熱源装置で加熱して槽他端部から槽内に戻す温熱蓄熱の蓄熱運転の場合についても、上記と同様の理由で、蓄熱に長時間を要し、また、蓄熱量が小さなものに制限される問題があった。
【００１０】
この実情に鑑み、本発明の主たる課題は、合理的な蓄熱形態を採ることにより上記問題を効果的に解消する点にある。
【００１１】
【課題を解決するための手段】
〔１〕請求項１に係る発明は潜熱蓄熱システムに係り、その特徴は、
槽一端部から取り出した槽内の熱媒液を熱源装置で冷却又は加熱して槽他端部から槽内に戻す蓄熱運転により槽内に冷熱又は温熱を蓄熱する蓄熱槽を設け、
潜熱蓄熱材を収容した蓄熱容器を槽内の熱媒液に浸漬させる状態で前記蓄熱槽の槽内に設置する潜熱蓄熱システムにおいて、
前記蓄熱槽を前記蓄熱運転において槽内に熱媒液の温度成層を形成する温度成層式の蓄熱槽にしてある点にある。
【００１２】
つまり、この構成によれば、槽一端部から取り出した槽内の熱媒液を熱源装置で冷却又は加熱して槽他端部から槽内に戻す蓄熱運転において蓄熱槽の槽内に熱媒液の温度成層を形成するから、熱源装置において熱媒液を冷却する冷熱蓄熱の蓄熱運転の場合、蓄熱運転の開始後、熱源装置からの冷却熱媒液の戻り部である槽他端部の側ほど、熱源装置からの冷却熱媒液の戻りによる槽内熱媒液温度の低下が早く進む形態になり、このことから、例えば図４に示す如き槽内の３箇所Ａ〜Ｃ、すなわち、熱源装置からの冷却熱媒液Ｗの戻り部（槽他端部）に近い入口近傍箇所Ａと、熱源装置への熱媒液Ｗの取り出し部（槽一端部）に近い出口近傍箇所Ｃと、それら２箇所Ａ，Ｃの間の中央に位置する中央近傍箇所Ｂとの３箇所について見た場合、それら３箇所Ａ〜Ｃ夫々における熱媒液温度ｔａ〜ｔｃは蓄熱運転の開始後、図５に示す如く変化する。
【００１３】
入口近傍箇所Ａの熱媒液温度ｔａは、蓄熱運転の開始後、熱源装置からの冷却熱媒液Ｗの戻りに伴い他の２箇所Ｂ，Ｃの熱媒液温度ｔｂ，ｔｃよりも大きな速度で低下していき、その温度低下で入口近傍箇所Ａの付近にある潜熱蓄熱材Ｘが相変化温度ｔｍに至って相変化を開始すると、その相変化に冷熱を要するため入口近傍箇所Ａの熱媒液温度ｔａは低下速度が若干小さくなるが、この相変化は入口近傍箇所Ａの付近にある潜熱蓄熱材Ｘのみの相変化であって、その相変化に要する冷熱量は熱源装置からの冷却熱媒液Ｗの戻りにより供給される冷熱量に比べ小さいため、入口近傍箇所Ａの熱媒液温度ｔａは入口近傍箇所Ａの付近にある潜熱蓄熱材Ｘの相変化中も比較的大きな速度で低下し続け、これにより、入口近傍箇所Ａの付近では槽内熱媒液Ｗと潜熱蓄熱材Ｘとの温度差（＝ｔｍ−ｔａ）が大きく確保された状態で、潜熱蓄熱材Ｘの相変化が進む。
【００１４】
その後、入口近傍箇所Ａの付近にある潜熱蓄熱材Ｘの相変化がある程度まで進むと、熱媒液Ｗと潜熱蓄熱材Ｘとの間での熱交換効率の低下の為、入口近傍箇所Ａの熱媒液温度ｔａは再び大きな速度で低下するが、出口近傍箇所Ｃの熱媒液温度ｔｃ（換言すれば、蓄熱槽から熱源装置に送る熱媒液の温度）が熱源装置の運転下限温度ｔｓよりも未だかなり高温であることから熱源装置の停止に至ることはなく、また、熱源装置が部分負荷運転の状態になることも効果的に防止され、これにより、入口近傍箇所Ａの付近では槽内熱媒液Ｗと潜熱蓄熱材Ｘとの温度差（＝ｔｍ−ｔａ）が一層大きく確保された状態で潜熱蓄熱材Ｘの相変化が最終段階まで進められる。
【００１５】
一方、中間近傍箇所Ｂの熱媒液温度ｔｂは、槽内における温度成層の形成のため入口近傍箇所Ａの熱媒液温度ｔａに比べ低下の開始が遅れるとともに、槽内における回避し得ないある程度の熱媒液混合の進行のため全体的に低下速度も入口近傍箇所Ａの熱媒液温度ｔａに比べ小さくなるが、出口近傍箇所Ｃの熱媒液温度ｔｃと比べれば、その度合いは小さくて、蓄熱運転の開始後、熱源装置からの冷却熱媒液Ｗの戻りに伴い出口近傍箇所Ｃの熱媒液温度ｔｃよりも大きな速度で低下していき、その温度低下で中央近傍箇所Ｂの付近にある潜熱蓄熱材Ｘが相変化温度ｔｍに至って相変化を開始すると、その相変化に冷熱を要するため中央近傍箇所Ｂの熱媒液温度ｔｂは低下速度が若干小さくなるが、入口近傍箇所Ａの場合と同様、この相変化は中央近傍箇所Ｂの付近にある潜熱蓄熱材Ｘのみの相変化であって、その相変化に要する冷熱量は熱源装置からの冷却熱媒液Ｗの戻りにより供給される冷熱量に比べ小さいため、中央近傍箇所Ｂの熱媒液温度ｔｂは中央近傍箇所Ｂの付近にある潜熱蓄熱材Ｘの相変化中も比較的大きな速度で低下し続け、これにより、中央近傍箇所Ｂの付近では入口近傍箇所Ａの付近に続き、槽内熱媒液Ｗと潜熱蓄熱材Ｘとの温度差（＝ｔｍ−ｔｂ）が大きく確保された状態で、潜熱蓄熱材Ｘの相変化が進む。
【００１６】
その後、中央近傍箇所Ｂの付近にある潜熱蓄熱材Ｘの相変化がある程度まで進むと、熱媒液Ｗと潜熱蓄熱材Ｘとの間での熱交換効率の低下の為、中央近傍箇所Ｂの熱媒液温度ｔｂは再び大きな速度で低下するが、入口近傍箇所Ａの場合と同様、出口近傍箇所Ｃの熱媒液温度ｔｃ（蓄熱槽から熱源装置に送る熱媒液の温度）が熱源装置の運転下限温度ｔｓよりも未だかなり高温であることから熱源装置の停止に至ることはなく、また、熱源装置が部分負荷運転の状態になることも効果的に防止され、これにより、入口近傍箇所Ｂの付近では入口近傍箇所Ａの付近に続き、槽内熱媒液Ｗと潜熱蓄熱材Ｘとの温度差（＝ｔｍ−ｔｂ）が一層大きく確保された状態で潜熱蓄熱材Ｘの相変化が最終段階まで進められる。
【００１７】
これに対し、出口近傍箇所Ｃの熱媒液温度ｔｃは、槽内における温度成層の形成のため中央近傍箇所Ｂの熱媒液温度ｔｂに比べ低下の開始がさらに遅れるとともに、槽内における回避し得ないある程度の熱媒液混合の一層の進行のため全体的に低下速度も中央近傍箇所Ｂの熱媒液温度ｔｃに比べさらに小さくなり、蓄熱運転の開始後、熱源装置からの冷却熱媒液Ｗの戻りに伴い比較的小さな速度で低下していき、その温度低下で出口近傍箇所Ｃの付近にある潜熱蓄熱材Ｘが相変化温度ｔｍに至って相変化を開始すると、その相変化に冷熱を要するため出口近傍箇所Ｃの熱媒液温度ｔｃはさらに低下速度が小さくなるが、他の２箇所Ａ，Ｂの場合と同様に、この相変化は出口近傍箇所Ｃの付近にある潜熱蓄熱材Ｘのみの相変化であって、その相変化に要する冷熱量は熱源装置からの冷却熱媒液Ｗの戻りにより供給される冷熱量に比べ小さいため、出口近傍箇所Ｃの熱媒液温度ｔｃは、潜熱蓄熱材Ｘの相変化を槽内全域について同時に進める場合に比べれば大きな速度を保って、出口近傍箇所Ｃの付近にある潜熱蓄熱材Ｘの相変化中も低下を続ける。
【００１８】
また、その後、出口近傍箇所Ｃの付近にある潜熱蓄熱材Ｘの相変化がある程度まで進むと、熱媒液Ｗと潜熱蓄熱材Ｘとの間での熱交換効率の低下の為、出口近傍箇所Ｃの熱媒液温度ｔｃは再び大きな速度で低下するようになり、そして、これら相変化中における出口近傍箇所Ｃの熱媒液温度ｔｃの低下（すなわち、熱源装置に送る熱媒液Ｗの温度低下）により熱源装置が部分負荷運転の状態に至ったり、運転停止に至るようになるが、その時点において、潜熱蓄熱材Ｘの相変化が途中の状態にあるのは出口近傍箇所Ｃの付近だけであり、槽内における入口近傍箇所Ａの付近及び中央近傍箇所Ｂの付近については潜熱蓄熱材Ｘの相変化が既に完了した状態にある。
【００１９】
以上の説明から明らかなように、上記構成によれば、槽内熱媒液と潜熱蓄熱材との温度差を大きく確保して潜熱蓄熱材の相変化速度を大きくすることができ、また、熱源装置が蓄熱運転の開始後の早い時期に部分負荷運転の状態になることも効果的に防止することができ、これらのことにより、先述した従来システムに比べ蓄熱に要する時間を効果的に短縮することができる。
【００２０】
そしてまた、従来システムの如く蓄熱槽の槽内全域について潜熱蓄熱材の相変化が未だ完全に完了していない状態で熱源装置が停止して蓄熱運転の終了に至ってしまうことも効果的に防止することができ、これにより、蓄熱量も効果的に増大させることができる。
【００２１】
なお、請求項１に係る発明によれば、熱源装置において熱媒液を加熱する温熱蓄熱の蓄熱運転の場合についても、上記と同様の効果を得ることができる。
【００２２】
〔２〕請求項２に係る発明は、請求項１に係る発明の実施に好適な実施形態を特定するものであり、その特徴は、
前記蓄熱槽を、複数の液槽を直列に接続した槽構成で、その直列接続列の列方向一端部から取り出した槽内の熱媒液を前記熱源装置で冷却又は加熱して前記直列接続列の列方向他端部から槽内へ戻す形態での前記蓄熱運転において熱媒液の一連の温度成層を複数の前記液槽にわたらせた状態でそれら液槽の槽内に形成する連結型の温度成層式蓄熱槽にし、
熱媒液の温度成層を槽内に形成する複数の前記液槽のうち一部数の液槽の槽内に前記蓄熱容器を設置してある点にある。
【００２３】
つまり、請求項１に係る発明の実施において連結型の温度成層式蓄熱槽を用いる場合であって、その連結型の温度成層式蓄熱槽を形成する直列接続の液槽のうち熱媒液の温度成層を槽内に形成する複数の液槽の全てに蓄熱容器を槽内設置すると、得られる蓄熱能力が過大となって設備コストに無駄が生じるような場合、上記の如く熱媒液の温度成層を槽内に形成する複数の液槽のうちの一部数の液槽に対してのみ蓄熱容器を槽内設置するようにすれば、また、その一部数として適当な液槽数を選定するようにすれば、所要の蓄熱能力を過不足無く得ることができて設備コストの無駄を回避することができる。
【００２４】
そして特に、潜熱蓄熱材を用いない単なる水蓄熱槽として使用していた既設の連結型温度成層式蓄熱槽を利用しながら、請求項１に係る発明の実施により蓄熱能力を必要分だけ増大させるシステム更新の場合に極めて有効である。
【００２５】
〔３〕請求項３に係る発明は、請求項１又は２に係る発明の実施に好適な実施形態を特定するものであり、その特徴は、
前記蓄熱運転の際に、前記熱源装置から前記蓄熱槽に戻す熱媒液の温度を設定温度に保ち、かつ、前記熱源装置の冷却負荷又は加熱負荷を設定負荷に保つように、前記蓄熱槽から前記熱源装置に送る熱媒液の流量をその送り熱媒液の温度に応じて調整する制御手段を設けてある点にある。
【００２６】
つまり、温度成層式の蓄熱槽では、槽内に熱媒液の良好な温度成層を形成する上で、蓄熱運転において熱源装置から蓄熱槽の槽他端部（請求項２に係る発明では前記直列接続列における列方向の他端部）に戻す熱媒液の温度を設定温度に安定的に維持することが要求されるが、上記構成において、設定負荷として熱源装置の許容最大負荷ないしそれに近い負荷を設定しておけば、蓄熱槽から熱源装置に送る熱媒液の温度変化に応じた送り熱媒液の流量調整により、熱源装置の冷却負荷や加熱負荷を熱源装置の許容最大負荷ないしそれに近い負荷に保つようにしながら（換言すれば、熱源装置を最大出力ないしそれに近い出力で継続的に運転して単位時間当たりの蓄熱量を大きく保つようにしながら）、蓄熱槽の槽他端部に戻す熱媒液の温度を設定温度に安定的に維持することができ、これにより、蓄熱に要する時間を一層効果的に短縮することができる。
【００２７】
〔４〕請求項４に係る発明は、請求項１〜３のいずれか１項に係る発明の実施に好適な実施形態を特定するものであり、その特徴は、
前記蓄熱槽の槽底に架台を設置して槽底と架台上面部との間に隙間を形成し、複数の前記蓄熱容器を収容した多孔構造の収容容器を前記架台の上面部に積層状態で載置して多数の蓄熱容器を前記蓄熱槽の槽内に設置してある点にある。
【００２８】
つまり、この構成によれば、蓄熱運転などの槽運転において架台上における収容容器の積層域に対し槽内熱媒液を通過させるのに、槽底と架台上面部との間の上記隙間を収容容器の積層域に対して熱媒液を上向きに送り出す液送出室、又は、収容容器の積層域から熱媒液を下向きに集合させる液集合室にした状態で、架台上における収容容器の積層域（すなわち、多数の蓄熱容器の設置域）に対し、槽内熱媒液を均等な状態で上向き又は下向きに安定的に通過させることができ、これにより、蓄熱槽の槽内に熱媒液の良好な温度成層を効果的かつ確実に形成することができて、請求項１に係る発明による前述の効果を一層確実に得ることができる。
【００２９】
また、多数の蓄熱容器を蓄熱槽の槽内に設置するのに、複数の蓄熱容器を収容した多孔構造の収容容器を架台上に積層状態で載置するから、槽外で複数の蓄熱容器を予め収容した収容容器を順次、槽内に搬入するようにして、収容容器を運搬容器に利用した形態で多数の蓄熱容器を能率良く容易に槽内に搬入設置することができ、これにより、システムの必要施工期間を短縮し得るとともに、システムコストを安価にすることができ、特に、潜熱蓄熱材を用いない単なる水蓄熱槽として使用していた既設の蓄熱槽を利用しながら、請求項１に係る発明の実施により蓄熱能力を増大させるシステム更新の場合に極めて有効である。
【００３０】
【発明の実施の形態】
〔第１実施形態〕
図１は潜熱蓄熱システムを示し、１は蓄熱槽、２は熱源装置としての冷凍機、３は負荷装置（例えば空調機やファンコイルユニット）であり、このシステムでは、蓄熱運転において熱源側循環路４を通じ蓄熱槽１と冷凍機２との間で熱媒液Ｗ（例えば水）を循環させることにより、冷凍機１の発生冷熱を蓄熱槽１に蓄熱し、一方、放熱運転において負荷側循環路５を通じ蓄熱槽１と負荷装置３との間で熱媒液Ｗを循環させることにより、先の蓄熱運転において蓄熱槽１に蓄熱した冷熱を負荷装置３で消費する。
【００３１】
蓄熱槽１は複数の液槽１ａ〜１ｅを直列に接続した連結型の温度成層式蓄熱槽であり、蓄熱運転では、図中実線の矢印で示す如く、液槽１ａ〜１ｅの直列接続列における列方向一端の液槽１ａ（すなわち、蓄熱槽１の槽一端部）から取り出した槽内の熱媒液Ｗを冷凍機２で冷却して上記直列接続列における列方向他端の液槽１ｅ（すなわち、蓄熱槽１の槽他端部）に戻すことに伴い、直列接続列における列方向両端の取出用及び戻し用の液槽１ａ，１ｅを除いた液槽１ｂ〜１ｄの夫々において液槽内の熱媒液Ｗを液槽内のほぼ全域にわたり均等かつ安定的な状態で上向きに槽内流動させ、これにより、液槽１ａ〜１ｅの直列接続列における列方向他端を低温端とし、かつ、列方向一端を高温端とする熱媒液Ｗの一連の温度成層を複数の液槽１ｂ〜１ｄにわたらせた状態でそれら液槽１ｂ〜１ｄの槽内に形成しながら、直列接続列の列方向他端（低温端）の側に位置する液槽から順次にその槽内に冷熱を蓄熱していく。
【００３２】
また、放熱運転では逆に、図中破線の矢印で示す如く、液槽１ａ〜１ｅの直列接続列における列方向他端の液槽１ｅから取り出した槽内の熱媒液Ｗを負荷装置３で冷熱放熱させた後、上記直列接続列における列方向一端の液槽１ａに戻すことに伴い、直列接続列における列方向両端の取出用及び戻し用の液槽１ａ，１ｅを除いた液槽１ｂ〜１ｄの夫々において液槽内の熱媒液Ｗを液槽内のほぼ全域にわたり均等かつ安定的な状態で下向きに槽内流動させ、これにより、複数の液槽１ｂ〜１ｄにわたる熱媒液Ｗの一連の温度成層を保つように、負荷装置３からの戻り熱媒液Ｗによる槽内熱媒液Ｗの高温化を直列接続列の列方向一端（高温端）の側に位置する液槽から順次に進めていく形態で、先の蓄熱運転において蓄熱槽１の槽内に蓄熱した冷熱を消費していく。
【００３３】
そして、本実施形態では上記した連結型の温度成層式蓄熱槽１として、具体的には、上記列方向他端の側に位置して上端部に横向きの上部水路６ａを形成する堰６と、上記列方向一端の側に位置して下端部に横向きの下部水路７ａを形成する逆堰７とにより、それら堰６，７の間に垂直水路８を形成して、隣合う液槽１ａ〜１ｄどうしを横向きの上部水路６ａと垂直水路８と横向きの下部水路７ａとからなる一連の連通水路を通じて連通させた構造のもぐり堰方式（ないし、改良もぐり堰方式）の蓄熱槽を採用している。
【００３４】
また、この蓄熱槽１は水蓄熱槽として使用していた既設の蓄熱槽をシステム更新の際に潜熱蓄熱用の蓄熱槽に改造したものであり、その改造として、液槽１ａ〜１ｅのうち、それら液槽の直列接続列における列方向他端（低温端）から２番目及び３番目の液槽１ｄ，１ｃの槽内には、図１，図２に示す如く潜熱蓄熱用の多数の蓄熱容器９を設置してある。
【００３５】
蓄熱容器９はビニル袋状のもので、その容器内には、負荷装置３で必要とする低温熱媒液Ｗの温度ないしその付近の温度（例えば６〜７℃）を固相と液相との間の相変化温度ｔｍとする冷熱蓄熱用の潜熱蓄熱材Ｘを収容してあり、システム更新において、この蓄熱容器９を液槽１ｃ，１ｄの槽内に設置する改造を施すことで、潜熱蓄熱を可能にして蓄熱槽全体としての蓄熱能力を必要分だけ増大させる。また、熱媒液Ｗの温度成層を形成する液槽１ｃ，１ｄの槽内に蓄熱容器９を設置して潜熱蓄熱を可能にすることにより、いわゆる混合式蓄熱槽の槽内に蓄熱容器９を設置して潜熱蓄熱を可能にするに比べ、短時間の蓄熱運転で大量の冷熱を蓄熱し得るとともに、放熱運転において負荷装置３に対し必要温度の低温熱媒液Ｗを温度変動の少ない状態で安定的に供給し得る更新システムを得る。
【００３６】
システム更新において蓄熱容器９を液槽１ｃ，１ｄの槽内に設置するにあたっては、同図１，図２に示す如く、先ず、液槽１ｃ，１ｄの槽底に架台１０を設置して槽底と架台上面部１０ａとの間に隙間Ｓを形成し、その後、槽外で多数の蓄熱容器９を予め収容したカゴ状の収容容器１１を順次、液槽１ｃ，１ｄに搬入して、それら収容容器１１を架台１０における多孔状の上面部１０ａに積層状態で載置することで、多数の蓄熱容器９を液槽１ｃ，１ｄの槽内に設置しており、これにより、蓄熱運転では、架台１０上における収容容器１１の積層域に対し槽内熱媒液Ｗを通過させるのに、槽底と架台上面部１０ａとの間の隙間Ｓを収容容器１１の積層域に対して熱媒液Ｗを上向きに送り出す液送出室にした状態で、架台１０上における収容容器１１の積層域（すなわち、多数の蓄熱容器９の設置域）に対し、槽内熱媒液Ｗを均等な状態で上向きに安定的に通過させ得るように、また、放熱運転では、その隙間Ｓを収容容器１１の積層域から熱媒液Ｗを下向きに集合させる液集合室にした状態で、架台１０上における収容容器１１の積層域に対し、槽内熱媒液Ｗを均等な状態で下向きに安定的に通過させ得るようにしてある。
【００３７】
Ｐ１は蓄熱運転において蓄熱槽１と冷凍機２との間で熱媒液Ｗを循環させる熱源側循環ポンプ、Ｐ２は放熱運転において蓄熱槽１と負荷装置３との間で熱媒液Ｗを循環させる負荷側循環ポンプ、また、１２は冷凍機１の発停や各循環ポンプＰ１，Ｐ２の発停などシステムの運転制御を司る制御器であり、この制御器１２はシステムの運転制御のうちの一つとして、温度センサ１３により検出される冷凍機２への送り熱媒液Ｗの温度ｔｉ、及び、予め入力されている参照データに基づき、蓄熱運転において冷凍機２から蓄熱槽１に戻す熱媒液Ｗの温度ｔｏを設定温度（例えば４℃）に保ち、かつ、冷凍機２の冷却負荷を冷凍機２の許容最大負荷ないしそれに近い負荷に保つように、蓄熱槽１から冷凍機２に送る熱媒液Ｗの流量をその送り熱媒液Ｗの温度ｔｉに応じ熱源側循環ポンプＰ１に対するインバータ制御により調整する。
【００３８】
〔第２実施形態〕
図３は蓄熱運転において温熱を蓄熱槽２１に蓄熱する潜熱蓄熱システムを示し、蓄熱槽２１は複数の液槽２１ａ〜２１ｅを直列に接続した連結型の温度成層式蓄熱槽であり、蓄熱運転では、図中実線の矢印で示す如く、液槽２１ａ〜２１ｅの直列接続列における列方向一端の液槽２１ａから取り出した槽内の熱媒液Ｗ（例えば水）をヒートポンプ２２で加熱して上記直列接続列における列方向他端の液槽２１ｅに戻すことに伴い、直列接続列における列方向両端の取出用及び戻し用の液槽２１ａ，２１ｅを除いた液槽２１ｂ〜２１ｄの夫々において液槽内の熱媒液Ｗを液槽内のほぼ全域にわたり均等かつ安定的な状態で下向きに槽内流動させ、これにより、液槽２１ａ〜２１ｅの直列接続列における列方向他端を高温端とし、かつ、列方向一端を低温端とする熱媒液Ｗの一連の温度成層を複数の液槽２１ｂ〜２１ｄにわたらせた状態でそれら液槽２１ｂ〜２１ｄの槽内に形成しながら、直列接続列の列方向他端（高温端）の側に位置する液槽から順次にその槽内にヒートポンプ２２の発生温熱を蓄熱していく。
【００３９】
また、放熱運転では逆に、図中破線の矢印で示す如く、液槽２１ａ〜２１ｅの直列接続列における列方向他端の液槽２１ｅから取り出した槽内の熱媒液Ｗを負荷装置３で温熱放熱させた後、上記直列接続列における列方向一端の液槽２１ａに戻すことに伴い、直列接続列における列方向両端の取出用及び戻し用の液槽２１ａ，２１ｅを除いた液槽２１ｂ〜２１ｄの夫々において液槽内の熱媒液Ｗを液槽内のほぼ全域にわたり均等かつ安定的な状態で上向きに槽内流動させ、これにより、複数の液槽２１ｂ〜２１ｄにわたる熱媒液Ｗの一連の温度成層を保つように、負荷装置３からの戻り熱媒液Ｗによる槽内熱媒液Ｗの低温化を直列接続列の列方向一端（低温端）の側に位置する液槽から順次に進めていく形態で、先の蓄熱運転において蓄熱槽２１の槽内に蓄熱した温熱を消費していく。
【００４０】
そして、本実施形態では上記した連結型の温度成層式蓄熱槽２１として、具体的には、上記列方向他端の側に位置して下端部に横向きの下部水路２６ａを形成する逆堰２６と、上記列方向一端の側に位置して上端部に横向きの上部水路２７ａを形成する堰２７とにより、それら堰２６，２７の間に垂直水路２８を形成して、隣合う液槽２１ｂ〜２１ｅどうしを横向きの下部水路２６ａと垂直水路２８と横向きの上部水路２７ａとからなる一連の連通水路を通じて連通させた構造のもぐり堰方式（ないし、改良もぐり堰方式）の蓄熱槽を採用している。
【００４１】
液槽２１ａ〜２１ｅのうち、それら液槽の直列接続列における列方向他端（高温端）から３番目及び４番目の液槽２１ｃ，２１ｂの槽内には、潜熱蓄熱用の多数の蓄熱容器２９を設置し、その蓄熱容器２９の容器内には、負荷装置３で必要とする高温熱媒液Ｗの温度ないしその付近の温度を固相と液相との間の相変化温度ｔｍ′とする温熱蓄熱用の潜熱蓄熱材Ｘ′を収容してあり、これにより、温度成層式の蓄熱槽２１において潜熱蓄熱による温熱蓄熱を可能にしてある。
【００４２】
１２′はヒートポンプ２１の発停や各循環ポンプＰ１，Ｐ２の発停などシステムの運転制御を司る制御器であり、この制御器１２′はシステムの運転制御のうちの一つとして、温度センサ１３′により検出されるヒートポンプ２２への送り熱媒液Ｗの温度ｔｉ、及び、予め入力されている参照データに基づき、蓄熱運転においてヒートポンプ２２から蓄熱槽２１に戻す熱媒液Ｗの温度ｔｏを設定温度に保ち、かつ、ヒートポンプ２２の加熱負荷をヒートポンプ２２の許容最大負荷ないしそれに近い負荷に保つように、蓄熱槽２１からヒートポンプ２２に送る熱媒液Ｗの流量をその送り熱媒液Ｗの温度ｔｉに応じ熱源側循環ポンプＰ１に対するインバータ制御により調整する。
【００４３】
〔別の実施形態〕
次に別実施形態を列記する。
【００４４】
前述の第１及び第２実施形態では、複数の液槽を直列に接続した連結型の温度成層式蓄熱槽を使用する例を示したが、使用する温度成層式の蓄熱槽は図４に示す如き単槽型のものであってもよい。
【００４５】
また、蓄熱槽における熱媒液の流出入構造など、熱媒液の温度成層を蓄熱槽の槽内に形成するための構造はどのようなものであってもよく、連結型の温度成層式蓄熱槽を使用する場合、その蓄熱槽はもぐり堰方式や改良もぐり堰方式のものに限られるものではない。
【００４６】
熱媒液には水や水溶液など種々の液体を使用でき、また、潜熱蓄熱材には冷熱蓄熱用の潜熱蓄熱材及び温熱蓄熱用の潜熱蓄熱材のいずれについても、パラフィン系の潜熱蓄熱材を初め、各種の材質のものを使用できる。
【００４７】
蓄熱した冷熱や温熱の用途は空調に限られるものではなく、物品の冷却や加熱など、どのようなものであってもよい。
【図面の簡単な説明】
【図１】第１実施形態を示すシステムの全体構成図
【図２】第１実施形態を示す槽内の斜視図
【図３】第２実施形態を示すシステムの全体構成図
【図４】蓄熱槽の概略側面図
【図５】槽内熱媒液温度の変化を示すグラフ
【図６】従来システムにおける槽内熱媒液温度の変化を示すグラフ
【符号の説明】
１　　　　　　　蓄熱槽
１ａ〜１ｅ　　　液槽
２　　　　　　　熱源装置
９　　　　　　　蓄熱容器
１０　　　　　　架台
１０ａ　　　　　架台上面部
１１　　　　　　収容容器
Ｓ　　　　　　　隙間
Ｗ　　　　　　　熱媒液
ｔｉ　　　　　　熱源装置から蓄熱槽に戻す熱媒液の温度
Ｘ　　　　　　　潜熱蓄熱材[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a latent heat storage system, and more specifically, a heat storage operation for cooling or heating a heat medium liquid in a tank taken out from one end of a tank with a heat source device and returning the heat transfer medium into the tank from the other end of the tank. The present invention relates to a latent heat storage system provided in a heat storage tank in a state in which a heat storage tank for storing heat is provided and a heat storage container containing a latent heat storage material is immersed in a heat medium liquid in the tank.
[0002]
[Prior art]
Conventionally, in the latent heat storage system as described above, in order to construct a system by installing a heat storage container accommodating a latent heat storage material in a tank of a heat storage tank, the heat storage tank is used in a tank operation such as a heat storage operation. The mixing type heat storage tank in which the heat medium liquid flows in the tank in a flow form involving the mixing of the heat medium liquid over almost the entire area in the tank.
[0003]
[Problems to be solved by the invention]
However, in this conventional latent heat storage system, in the case of a heat storage operation of cold heat storage in which the heat transfer medium in the tank taken out from one end of the tank is cooled by a heat source device and returned to the inside of the tank from the other end of the tank, the following heat storage operation is performed. Progresses.
[0004]
After the start of the heat storage operation, the heating medium liquid is mixed over the entire area of the tank due to the flow of the heating medium liquid in the tank, and the cooling heat medium liquid (for example, 4 ° C.) is returned from the heat source device (refrigerator). As shown in FIG. 6, the temperature t of the heat transfer medium in the heat storage tank decreases uniformly over the entire area of the tank with a decrease in the temperature of the latent heat storage material. (For example, 6 to 7 ° C.), the phase change of the latent heat storage material starts in the entire region in the tank, and the phase change of the latent heat storage material in the entire region in the tank requires a large amount of cold heat. Regardless of the return of the cooling heat medium liquid, the phase change of the latent heat storage material proceeds while the temperature t of the heat medium liquid in the tank is uniformly maintained at a temperature close to the phase change temperature tm of the latent heat storage material over the entire area in the tank. .
[0005]
When the phase change of the latent heat storage material in the heat storage container progresses to a certain extent, the heat exchange efficiency between the heat medium liquid and the latent heat storage material is reduced, so that the entire area in the tank accompanying the flow of the heat medium liquid in the tank is reduced. When the cooling medium is returned from the heat source device, the temperature t of the heating medium in the tank starts to decrease uniformly again over the entire area in the tank.
[0006]
In other words, in the conventional latent heat storage system, the temperature of the heat transfer medium in the tank is maintained at a temperature close to the phase change temperature tm of the latent heat storage material in the entire area of the tank (that is, the heat transfer medium in the tank is maintained in the entire area of the tank). The phase change of the latent heat storage material proceeds while the temperature difference between the latent heat storage material and the latent heat storage material remains small. Therefore, the phase change of the latent heat storage material is an important determinant of the temperature difference between the heat transfer fluid and the latent heat storage material. Since the speed is limited to a small value, there is a problem that it takes a long time to store heat due to a phase change of the latent heat storage material.
[0007]
After the start of the heat storage operation as described above, the temperature t of the heat medium liquid in the tank is uniformly reduced over the entire area of the tank. Therefore, the temperature of the heat medium liquid sent from the heat storage tank to the heat source device is also changed after the start of the heat storage operation. And the temperature of the heat transfer liquid sent to the heat source device is lowered at an early stage after the start of the heat storage operation. The heat source device enters the partial load operation state early after the start, and the cooling amount per unit time in the heat source device (in other words, the amount of cold heat storage per unit time) is limited to a small value. Therefore, there is a problem that the time required for heat storage becomes long.
[0008]
Moreover, in the conventional latent heat storage system, as described above, when the phase change of the latent heat storage material progresses to a certain extent, the temperature of the heat medium liquid t in the tank starts to decrease again in a uniform state over the entire area in the tank. At the time when the phase change of the latent heat storage material has not been completely completed yet when the temperature of the heat transfer medium sent to the apparatus falls in synchronism with the decrease in the temperature of the heat transfer medium in the tank, the operation lower limit temperature ts of the heat source apparatus When the heat source device is stopped, the heat storage operation is terminated in a state where the phase change of the latent heat storage material has not yet been completely completed for the entire area of the heat storage tank, which limits the heat storage amount to a small amount. There was also a problem.
[0009]
Note that in the conventional latent heat storage system, the same applies to the case of the heat storage operation of the heat storage system in which the heat transfer medium in the tank taken out from one end of the tank is heated by the heat source device and returned to the inside of the tank from the other end of the tank. For this reason, there has been a problem that heat storage requires a long time and the amount of heat storage is limited to a small amount.
[0010]
In view of this situation, a main problem of the present invention is that the above problem is effectively solved by adopting a rational form of heat storage.
[0011]
[Means for Solving the Problems]
[1] The invention according to claim 1 relates to a latent heat storage system.
A heat storage tank that stores cold or warm heat in the tank by a heat storage operation that cools or heats the heat medium liquid in the tank taken out from one end of the tank with a heat source device and returns it to the tank from the other end of the tank,
In a latent heat storage system installed in a tank of the heat storage tank in a state where a heat storage container containing a latent heat storage material is immersed in a heat medium liquid in the tank,
The heat storage tank is a temperature stratification type heat storage tank that forms a temperature stratification of a heat medium liquid in the tank in the heat storage operation.
[0012]
That is, according to this configuration, in the heat storage operation in which the heat medium liquid in the tank taken out from one end of the tank is cooled or heated by the heat source device and returned into the tank from the other end, the heat medium liquid is stored in the heat storage tank. In the case of the heat storage operation of the cold heat storage for cooling the heat medium liquid in the heat source device, after the heat storage operation is started, the side of the other end of the tank that is the return portion of the cooling heat medium liquid from the heat source device is formed. As the cooling heat medium liquid returns from the heat source device, the temperature of the heat medium liquid in the tank decreases more rapidly. Therefore, for example, three points A to C in the tank as shown in FIG. A portion A near the inlet near the return portion (the other end of the tank) of the cooling heat medium W from the device, and a portion C near the outlet near the take-out portion (one end of the tank) of the heat medium W to the heat source device. When looking at three places, that is, the place B near the center located at the center between the two places A and C, Heat transfer fluid temperature ta~tc in people et three A~C husband after the start of the thermal storage operation, changes as shown in FIG.
[0013]
After the heat storage operation is started, the temperature of the heat medium liquid ta near the inlet is higher than the heat medium liquid temperatures tb and tc of the other two places B and C due to the return of the cooling heat medium liquid W from the heat source device. When the latent heat storage material X near the entrance A near the inlet reaches the phase change temperature tm and starts a phase change due to the temperature decrease, the heat transfer medium near the entrance A near the entrance is required because the phase change requires cold heat. Although the rate of decrease in the liquid temperature ta is slightly reduced, this phase change is a phase change of only the latent heat storage material X near the location A near the inlet, and the amount of cold required for the phase change is the cooling heat from the heat source device. Since it is smaller than the amount of cold heat supplied by the return of the medium W, the temperature ta of the heat medium at the point A near the inlet drops at a relatively large speed even during the phase change of the latent heat storage material X near the point A near the inlet. In the vicinity of the entrance A, the vicinity of the tank A In a state where the temperature difference between the medium liquid W and latent heat storage material X (= tm-ta) is kept large, the phase change of the latent heat storage material X progresses.
[0014]
Thereafter, when the phase change of the latent heat storage material X in the vicinity of the entrance location A progresses to a certain extent, the heat exchange efficiency between the heat medium liquid W and the latent heat storage material X decreases, so The temperature of the heat medium liquid ta drops again at a large rate, but the temperature of the heat medium liquid tc at the location C near the outlet (in other words, the temperature of the heat medium liquid sent from the heat storage tank to the heat source device) becomes lower than the operating lower limit temperature ts of the heat source device. Since the temperature of the heat source device is still much higher than that of the heat source device, the heat source device does not stop, and the heat source device is also effectively prevented from being in a partial load operation. The phase change of the latent heat storage material X is advanced to the final stage in a state where the temperature difference (= tm−ta) between the internal heat medium liquid W and the latent heat storage material X is further secured.
[0015]
On the other hand, the temperature of the heat medium liquid tb at the intermediate location B is slower than the heat medium temperature ta at the inlet area A due to the formation of the temperature stratification in the tank, and the heat medium temperature tb is inevitable in the tank. Due to the progress of the heat medium liquid mixing, the overall decrease speed is also lower than the heat medium liquid temperature ta at the point A near the inlet, but the degree is smaller than the temperature tc of the heat medium liquid at the point C near the outlet. After the start of the heat storage operation, the temperature of the heat medium liquid tc at the location C near the outlet decreases at a speed larger than the temperature tc of the location C near the outlet due to the return of the cooling medium W from the heat source device. When the latent heat storage material X in the above reaches the phase change temperature tm and starts a phase change, the heat change liquid temperature tb in the vicinity B of the center slightly lowers because the phase change requires cold heat, but the temperature Ab near the entrance A As in the case of this phase change This is a phase change of only the latent heat storage material X near the center vicinity B, and the amount of cooling required for the phase change is smaller than the amount of cooling supplied by the return of the cooling medium W from the heat source device. The heat medium liquid temperature tb in the vicinity B of the center continues to decrease at a relatively large speed even during the phase change of the latent heat storage material X in the vicinity of the vicinity B of the center. Following the vicinity of A, the phase change of the latent heat storage material X proceeds in a state where a large temperature difference (= tm−tb) between the in-tank heat medium liquid W and the latent heat storage material X is secured.
[0016]
Thereafter, when the phase change of the latent heat storage material X in the vicinity of the central location B progresses to a certain extent, the heat exchange efficiency between the heat medium liquid W and the latent heat storage material X decreases, so Although the temperature of the heat medium liquid tb decreases again at a large speed, the temperature of the heat medium liquid tc at the point C near the outlet (the temperature of the heat medium liquid sent from the heat storage tank to the heat source device) is the same as in the case of the point A near the inlet. Is still much higher than the operation lower limit temperature ts, the heat source device does not stop, and the heat source device is also effectively prevented from being in a partial load operation. In the vicinity of B, the phase change of the latent heat storage material X is continued in the state where the temperature difference (= tm−tb) between the heat medium liquid W in the tank and the latent heat storage material X is further secured. Proceed to the final stage.
[0017]
On the other hand, the temperature of the heat medium liquid tc at the location C near the outlet is further delayed from the start at a lower temperature than the temperature tb of the heat medium liquid at the location B near the center due to the formation of the temperature stratification in the tank, and the temperature in the tank is avoided. Due to the further progress of the mixing of the heat medium liquid to a certain extent, the rate of decrease in the heat medium liquid as a whole becomes further smaller than the temperature tc of the heat medium liquid at the point B near the center. As the temperature of the latent heat storage material X in the vicinity of the outlet C reaches the phase change temperature tm and starts a phase change due to the decrease in the temperature, the cooling heat is applied to the phase change. Therefore, the rate of decrease in the temperature tc of the heat transfer medium at the location C near the outlet is further reduced, but this phase change is caused by the latent heat storage material X near the location C near the outlet, as in the other two locations A and B. Phase change only Since the amount of cold required for the conversion is smaller than the amount of cold supplied by the return of the cooling medium W from the heat source device, the temperature tc of the heating medium near the outlet C is determined by the phase change of the latent heat storage material X in the tank. As compared with the case of simultaneously proceeding over the entire region, the speed is kept higher and the temperature of the latent heat storage material X near the exit point C is continuously reduced during the phase change.
[0018]
After that, when the phase change of the latent heat storage material X in the vicinity of the location C near the outlet proceeds to some extent, the heat exchange efficiency between the heat medium liquid W and the latent heat storage material X decreases, so that the location near the outlet is reduced. The temperature tc of the heat transfer fluid at C decreases again at a large rate, and the temperature tc of the heat transfer fluid at the location C near the outlet during these phase changes decreases (that is, the temperature of the heat transfer fluid W sent to the heat source device). As a result, the phase change of the latent heat storage material X is in the middle state at that time only in the vicinity of the exit point C. The phase change of the latent heat storage material X has already been completed in the vicinity of the location A near the entrance and the location B near the center in the tank.
[0019]
As is clear from the above description, according to the above configuration, it is possible to increase the phase change speed of the latent heat storage material by securing a large temperature difference between the heat transfer medium in the tank and the latent heat storage material, It is also possible to effectively prevent the device from entering the state of partial load operation early after the start of the heat storage operation, thereby effectively reducing the time required for the heat storage as compared with the above-described conventional system. be able to.
[0020]
Further, it is also possible to effectively prevent the heat source device from stopping and terminating the heat storage operation in a state where the phase change of the latent heat storage material has not yet been completely completed in the entire area of the heat storage tank as in the conventional system. Therefore, the heat storage amount can be effectively increased.
[0021]
According to the first aspect of the invention, the same effect as described above can be obtained also in the case of the heat storage operation of the heat storage device that heats the heat medium liquid in the heat source device.
[0022]
[2] The invention according to claim 2 specifies an embodiment suitable for carrying out the invention according to claim 1, and its features are as follows.
The heat storage tank is a tank configuration in which a plurality of liquid tanks are connected in series, and the heat medium liquid in the tank taken out from one end in the column direction of the series connection row is cooled or heated by the heat source device and the series connection row is connected. In the heat storage operation in the form of returning to the inside of the tank from the other end in the column direction, a continuous temperature stratification of the heat medium liquid is formed in the tanks of the liquid tanks while being spread over the plurality of the liquid tanks. In a stratified thermal storage tank,
The point is that the heat storage container is installed in a part of the plurality of liquid tanks forming the temperature stratification of the heat medium liquid in the tank.
[0023]
In other words, in the embodiment of the invention according to claim 1, a case where a connected-type temperature-stratified heat storage tank is used, and the temperature of the heat medium liquid in the series-connected liquid tanks forming the connected-type temperature-stratified heat storage tank is used. If the heat storage containers are installed in the tanks in all of the plurality of liquid tanks in which the stratification is formed in the tank, the obtained heat storage capacity becomes excessive and wastes equipment costs. If the heat storage container is installed in the tank only for a part of the plurality of liquid tanks formed in the tank, an appropriate number of liquid tanks should be selected as a part of the heat storage container. Then, the required heat storage capacity can be obtained without excess or shortage, and waste of facility costs can be avoided.
[0024]
In particular, a system for increasing the heat storage capacity by a necessary amount by implementing the invention according to claim 1 while utilizing an existing connected-type temperature-stratified heat storage tank used as a simple water heat storage tank that does not use a latent heat storage material. This is extremely effective for updating.
[0025]
[3] The invention according to claim 3 specifies an embodiment suitable for carrying out the invention according to claim 1 or 2, and its features are as follows.
At the time of the heat storage operation, the temperature of the heat medium liquid returned from the heat source device to the heat storage tank is maintained at a set temperature, and the cooling load or the heating load of the heat source device is maintained at the set load. Control means for adjusting the flow rate of the heat transfer medium to be sent to the heat source device according to the temperature of the heat transfer medium is provided.
[0026]
That is, in the thermal stratification-type heat storage tank, in order to form a favorable temperature stratification of the heat medium liquid in the tank, the other end of the heat storage tank (from the serial connection in the invention according to claim 2), from the heat source device in the heat storage operation. It is required to stably maintain the temperature of the heat transfer fluid returned to the other end in the row direction in the connection row) at the set temperature. In the above configuration, the set load is the allowable maximum load of the heat source device or a load close thereto. By setting the flow rate of the sending heat medium liquid according to the temperature change of the heating medium liquid sent from the heat storage tank to the heat source device, the cooling load and the heating load of the heat source device can be set at or near the maximum allowable load of the heat source device. Returning to the other end of the heat storage tank while maintaining the load (in other words, while continuously operating the heat source device at or near the maximum output to maintain a large amount of heat storage per unit time). The temperature of the heat transfer fluid Can be stably maintained at a constant temperature, thereby, the time required for the heat storage can be more effectively shortened.
[0027]
[4] The invention according to claim 4 specifies an embodiment suitable for carrying out the invention according to any one of claims 1 to 3, and its features are as follows.
A gantry is installed at the bottom of the heat storage tank to form a gap between the bottom of the tank and the top of the gantry, and a storage container having a porous structure containing a plurality of the heat storage containers is stacked on the top of the gantry. The point is that a large number of heat storage containers are placed and installed in the heat storage tank.
[0028]
In other words, according to this configuration, in the tank operation such as the heat storage operation, the gap between the tank bottom and the upper surface of the pedestal is accommodated in the lamination area of the storage container on the pedestal in order to allow the heat medium liquid in the tub to pass therethrough. In a state in which the liquid delivery chamber sends out the heat medium liquid upward to the stacking area of the container, or the liquid collecting chamber in which the heat transfer medium is gathered downward from the stacking area of the storage container, the stacking area of the storage container on the gantry is set. (That is, the heat medium liquid in the tank can be stably passed upward or downward in a uniform state with respect to the installation area of the large number of heat storage containers, and thereby, Good temperature stratification can be effectively and reliably formed, and the above-described effect according to the first aspect of the invention can be more reliably obtained.
[0029]
In addition, when a large number of heat storage containers are installed in the heat storage tank, a plurality of heat storage containers are housed in a stacked state on the pedestal. The storage containers that are stored in advance are sequentially loaded into the tank, and a large number of heat storage containers can be efficiently loaded and installed in the tank efficiently and efficiently using the storage container as a transport container. The required construction period can be shortened, and the system cost can be reduced. In particular, while using an existing heat storage tank that has been used as a mere water heat storage tank that does not use a latent heat storage material, This is extremely effective in the case of updating the system to increase the heat storage capacity by implementing the invention.
[0030]
BEST MODE FOR CARRYING OUT THE INVENTION
[First Embodiment]
FIG. 1 shows a latent heat storage system, 1 is a heat storage tank, 2 is a refrigerator as a heat source device, and 3 is a load device (for example, an air conditioner or a fan coil unit). 4 circulates a heat medium liquid W (for example, water) between the heat storage tank 1 and the refrigerator 2 to store the cold generated by the refrigerator 1 in the heat storage tank 1, while, on the other hand, the load side circulation path in the heat dissipation operation. By circulating the heat medium liquid W between the heat storage tank 1 and the load device 3 through 5, the cold heat stored in the heat storage tank 1 in the previous heat storage operation is consumed by the load device 3.
[0031]
The heat storage tank 1 is a connection-type temperature stratified heat storage tank in which a plurality of liquid tanks 1a to 1e are connected in series. In the heat storage operation, as shown by solid-line arrows in the figure, the liquid tanks 1a to 1e are connected in series. The heat transfer medium W in the tank taken out from the liquid tank 1a at one end in the row direction (that is, one end of the heat storage tank 1) is cooled by the refrigerator 2 and the liquid tank 1e at the other end in the row direction in the series connection row ( That is, with the return to the heat storage tank 1 (the other end of the heat storage tank 1), each of the liquid tanks 1b to 1d except for the liquid tanks 1a and 1e for taking out and returning at both ends in the column direction in the series connection row has Is caused to flow upward in the tank in a uniform and stable state over almost the entire area in the liquid tank, whereby the other end of the liquid tanks 1a to 1e in the column direction in the series connection row is set to the low temperature end, and A series of temperature stratifications of the heat transfer liquid W having one end in the row direction as a high temperature end To the liquid tanks 1b to 1d while being stored in the liquid tanks located at the other end (low-temperature end) in the column direction of the serially connected rows. I will do it.
[0032]
Conversely, in the heat dissipation operation, as shown by the dashed arrow in the drawing, the heat medium liquid W in the tank taken out of the liquid tank 1e at the other end in the column direction in the series connection line of the liquid tanks 1a to 1e is loaded by the load device 3. After radiating the cold heat, the liquid tanks 1b to 1e are removed from the liquid tanks 1a to 1d in the series connection row except for the take-out and return liquid tanks 1a and 1e at both ends in the row direction in the series connection row. In each of 1d, the heat medium liquid W in the liquid tank is caused to flow downward in the tank in an even and stable state over substantially the entire area of the liquid tank, whereby the heat medium liquid W in the plurality of liquid tanks 1b to 1d is discharged. In order to maintain a series of temperature stratification, the temperature of the heat transfer medium W in the tank is increased by the return heat transfer liquid W from the load device 3 sequentially from the liquid tank located at one end (high-temperature end) in the column direction of the series connection row. In the heat storage operation, the cold stored in the heat storage tank 1 Continue to consume.
[0033]
In the present embodiment, as the above-mentioned connected-type temperature-stratified heat storage tank 1, specifically, a weir 6 that is located on the other end side in the column direction and forms a horizontal upper water passage 6 a at the upper end, The vertical weir 6 is formed between the weirs 6 and 7 by the reverse weir 7 which is located at one end side in the row direction and forms a lower waterway 7a at the lower end in a horizontal direction, and the adjacent liquid tanks 1a to 1d. A heat storage tank of a mug weir system (or an improved mug weir system) having a structure in which the two are connected to each other through a series of communicating water channels composed of a horizontal upper water channel 6a, a vertical water channel 8, and a horizontal lower water channel 7a is adopted.
[0034]
The heat storage tank 1 is obtained by remodeling an existing heat storage tank used as a water heat storage tank into a heat storage tank for latent heat storage at the time of system update. As the remodeling, of the liquid tanks 1a to 1e, In the tanks of the second and third liquid tanks 1d and 1c from the other end (low temperature end) in the column direction in the series connection row of these liquid tanks, a large number of heat storage containers for latent heat storage as shown in FIGS. 9 are installed.
[0035]
The heat storage container 9 is in the shape of a vinyl bag, in which the temperature of the low-temperature heat medium liquid W required by the load device 3 or a temperature in the vicinity thereof (for example, 6 to 7 ° C.) is defined as a solid phase and a liquid phase. And a latent heat storage material X for cold heat storage having a phase change temperature of tm between the heat storage containers X. In the system renewal, the heat storage container 9 is installed in the liquid tanks 1c and 1d so that the latent heat storage material X is modified. Heat storage is enabled to increase the heat storage capacity of the entire heat storage tank by a necessary amount. Also, by installing the heat storage container 9 in the tanks of the liquid tanks 1c and 1d for forming the temperature stratification of the heat medium liquid W to enable latent heat storage, the heat storage container 9 is stored in the so-called mixed type heat storage tank. Compared to the case of installing the latent heat storage, a large amount of cold heat can be stored in a short heat storage operation, and the low-temperature heat transfer fluid W at a required temperature is supplied to the load device 3 in the heat dissipation operation in a state where the temperature fluctuation is small. An update system that can be supplied stably is obtained.
[0036]
In installing the heat storage container 9 in the tanks of the liquid tanks 1c and 1d in the system renewal, first, as shown in FIGS. 1 and 2, a gantry 10 is installed on the tank bottoms of the liquid tanks 1c and 1d. A gap S is formed between the base and the pedestal upper surface 10a. Thereafter, the cage-shaped storage containers 11 in which a large number of heat storage containers 9 are stored in advance outside the tank are sequentially loaded into the liquid tanks 1c and 1d, and are stored therein. A large number of heat storage containers 9 are placed in the liquid tanks 1c and 1d by placing the containers 11 on the porous upper surface 10a of the gantry 10 in a stacked state. In order to allow the heat medium liquid W in the tank to pass through the stacking region of the storage container 11 on the container 10, the gap S between the tank bottom and the pedestal upper surface portion 10 a is formed in the stacking region of the storage container 11. In a liquid delivery chamber for delivering the water upward, and In order to allow the heat transfer liquid W in the tank to pass stably upward in a uniform state in the lamination area of 11 (that is, the installation area of a large number of heat storage containers 9), the gap S is set in the heat dissipation operation. In a liquid collecting chamber for collecting the heat medium liquid W downward from the stacking area of the storage container 11, and the heat medium liquid W in the tank is uniformly and downwardly directed to the stacking area of the storage container 11 on the gantry 10. To allow stable passage.
[0037]
P1 is a heat source side circulating pump that circulates the heat medium W between the heat storage tank 1 and the refrigerator 2 in the heat storage operation, and P2 circulates the heat medium liquid W between the heat storage tank 1 and the load device 3 in the heat dissipation operation. A load-side circulating pump 12 is a controller for controlling the operation of the system, such as starting and stopping the refrigerator 1 and starting and stopping the circulation pumps P1 and P2. The controller 12 is included in the operation control of the system. For example, based on the temperature ti of the heat transfer medium W sent to the refrigerator 2 detected by the temperature sensor 13 and the reference data input in advance, the heat returned from the refrigerator 2 to the heat storage tank 1 in the thermal storage operation. From the heat storage tank 1 to the refrigerator 2, the temperature to of the medium W is maintained at a set temperature (for example, 4 ° C.), and the cooling load of the refrigerator 2 is maintained at or near the maximum allowable load of the refrigerator 2. The flow rate of the heating medium W to be sent is Adjusted by inverter control for the heat source-side circulation pump P1 depending on the temperature ti.
[0038]
[Second embodiment]
FIG. 3 shows a latent heat storage system that stores heat in the heat storage tank 21 in the heat storage operation. The heat storage tank 21 is a connected temperature stratified heat storage tank in which a plurality of liquid tanks 21a to 21e are connected in series. As shown by the solid line arrows in the figure, the heat transfer medium W (for example, water) in the tank taken out from the liquid tank 21a at one end in the column direction in the series connection row of the liquid tanks 21a to 21e is heated by the heat pump 22 and the above series is connected. With the return to the liquid tank 21e at the other end in the column direction in the connection row, the liquid tanks 21b to 21d in the serial connection row except for the take-out and return liquid tanks 21a and 21e at both ends in the row direction in the series connection row Is caused to flow downward in the tank in a uniform and stable state over almost the entire area in the liquid tank, whereby the other end in the column direction of the series connection of the liquid tanks 21a to 21e is set to the high temperature end, and , Column direction Is formed in a plurality of liquid tanks 21b to 21d in a state where a series of temperature stratifications of the heat medium liquid W having a low temperature end is spread in the plurality of liquid tanks 21b to 21d, and the other end in the column direction of the series connection line ( The heat generated by the heat pump 22 is sequentially stored in the liquid tank located on the side of the high-temperature end).
[0039]
On the other hand, in the heat dissipation operation, as shown by the dashed arrow in the figure, the heat medium W in the tank taken out from the liquid tank 21e at the other end in the column direction in the series connection row of the liquid tanks 21a to 21e is loaded by the load device 3. After returning to the liquid tank 21a at one end in the column direction in the series connection row after the heat is radiated, the liquid tanks 21b to 21b, except for the take-out and return liquid tanks 21a and 21e at both ends in the column direction in the series connection row. In each of the liquid tanks 21d, the heat medium liquid W in the liquid tank is caused to flow upward in the tank in an even and stable state over substantially the entire area of the liquid tank, whereby the heat medium liquid W in the plurality of liquid tanks 21b to 21d is formed. In order to maintain a series of temperature stratification, the temperature of the heat transfer medium W in the tank is lowered by the heat transfer liquid W returned from the load device 3 in order from the liquid tank positioned at one end (low temperature end) in the column direction of the series connection row. In the heat storage operation, the heat storage tank We continue to consume the heat storage the heat to 1 in the tank.
[0040]
In the present embodiment, as the above-mentioned connected-type temperature-stratified heat storage tank 21, specifically, a reverse weir 26 which is located at the other end in the column direction and forms a horizontal lower water passage 26 a at the lower end portion And a weir 27 located at one end side in the column direction and forming a laterally upper water passage 27a at the upper end, thereby forming a vertical water passage 28 between the weirs 26 and 27, and adjacent liquid tanks 21b to 21e. A heat storage tank of a mug weir system (or an improved mug weir system) having a structure in which the two are connected to each other through a series of communicating water channels including a horizontal lower water channel 26a, a vertical water channel 28, and a horizontal upper water channel 27a is adopted.
[0041]
Among the liquid tanks 21a to 21e, the third and fourth liquid tanks 21c and 21b from the other end (high-temperature end) in the column direction in the series connection line of the liquid tanks have a large number of heat storage containers for storing latent heat. 29, and the temperature of the high-temperature heat transfer fluid W required by the load device 3 or the temperature in the vicinity thereof is set as the phase change temperature tm ′ between the solid phase and the liquid phase in the heat storage vessel 29. A latent heat storage material X 'for storing heat is stored therein, thereby enabling heat storage by latent heat storage in the temperature stratified heat storage tank 21.
[0042]
A controller 12 'controls the operation of the system such as starting and stopping the heat pump 21 and starting and stopping the circulating pumps P1 and P2. The controller 12' is a temperature sensor 13 as one of the operation controls of the system. ′, The temperature to of the heat transfer fluid W to be returned from the heat pump 22 to the heat storage tank 21 in the heat storage operation is set based on the temperature ti of the heat transfer fluid W sent to the heat pump 22 and the reference data input in advance. The flow rate of the heat transfer liquid W sent from the heat storage tank 21 to the heat pump 22 is adjusted to the temperature of the heat transfer liquid W so as to maintain the temperature and the heating load of the heat pump 22 at the allowable maximum load of the heat pump 22 or a load close thereto. Adjustment is performed by inverter control of the heat source side circulation pump P1 according to ti.
[0043]
[Another embodiment]
Next, another embodiment will be described.
[0044]
In the above-described first and second embodiments, the example in which the connected temperature stratified heat storage tank in which a plurality of liquid tanks are connected in series is used, but the temperature stratified heat storage tank to be used is shown in FIG. Such a single tank type may be used.
[0045]
In addition, any structure for forming the temperature stratification of the heat medium liquid in the heat storage tank, such as a structure for inflow and outflow of the heat medium liquid in the heat storage tank, may be used. In the case of using a tank, the heat storage tank is not limited to the mug weir system or the improved mug weir system.
[0046]
Various liquids such as water and aqueous solution can be used as the heat medium liquid, and a paraffin-based latent heat storage material is used for both the latent heat storage material for cold heat storage and the latent heat storage material for warm heat storage as the latent heat storage material. Initially, various materials can be used.
[0047]
The application of the stored cold or warm heat is not limited to air conditioning, but may be any application such as cooling or heating of articles.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a system according to a first embodiment.
FIG. 2 is a perspective view of the inside of a tank showing the first embodiment.
FIG. 3 is an overall configuration diagram of a system according to a second embodiment.
FIG. 4 is a schematic side view of a heat storage tank.
FIG. 5 is a graph showing a change in the temperature of the heat transfer medium in the tank.
FIG. 6 is a graph showing a change in the temperature of a heating medium in a tank in a conventional system.
[Explanation of symbols]
1 thermal storage tank
1a-1e liquid tank
2 Heat source device
9 Thermal storage container
10 gantry
10a Top surface of gantry
11 container
S gap
W Heat medium liquid
ti Temperature of the heat transfer fluid returned from the heat source device to the heat storage tank
X latent heat storage material

Claims

A heat storage tank that stores cold or warm heat in the tank by a heat storage operation that cools or heats the heat medium liquid in the tank taken out from one end of the tank with a heat source device and returns it to the tank from the other end of the tank,
A latent heat storage system installed in a tank of the heat storage tank in a state where a heat storage container containing a latent heat storage material is immersed in a heat medium liquid in the tank,
A latent heat storage system, wherein the heat storage tank is a temperature stratification type heat storage tank that forms a temperature stratification of a heat medium liquid in the tank in the heat storage operation.

The heat storage tank is a tank configuration in which a plurality of liquid tanks are connected in series, and the heat medium liquid in the tank taken out from one end in the column direction of the series connection row is cooled or heated by the heat source device and the series connection row is connected. In the heat storage operation in the form of returning to the inside of the tank from the other end in the column direction, a continuous temperature stratification of the heat medium liquid is formed in the tanks of the liquid tanks while being spread over the plurality of the liquid tanks. In a stratified thermal storage tank,
2. The latent heat storage system according to claim 1, wherein the heat storage container is installed in a part of the plurality of liquid tanks that form a temperature stratification of the heat medium liquid in the tank. 3.

At the time of the heat storage operation, the temperature of the heat medium liquid returned from the heat source device to the heat storage tank is maintained at a set temperature, and the cooling load or the heating load of the heat source device is maintained at the set load. The latent heat storage system according to claim 1, further comprising a control unit that adjusts a flow rate of the heat medium liquid sent to the heat source device according to a temperature of the heat medium liquid.

Forming a gap between the tank bottom and the top of the gantry by installing a gantry on the bottom of the heat storage tank,
4. The heat storage container according to any one of claims 1 to 3, wherein a plurality of heat storage containers are placed in a stack of the heat storage containers, and a plurality of heat storage containers are placed in a stacked state on the upper surface of the gantry. The latent heat storage system according to claim 1.