JP2004271004A

JP2004271004A - Heat storage device

Info

Publication number: JP2004271004A
Application number: JP2003060423A
Authority: JP
Inventors: Makoto Suganuma; 誠菅沼; Saburo Totani; 三郎戸谷; Teru Hanabusa; 輝花房; Hideo Kitaguchi; 秀夫北口; Katsuyuki Tanii; 克之谷井; Hiroyuki Uragami; 弘之浦上; Koji Ogawa; 浩二小川; Hideo Watanabe; 秀雄渡邉; Koji Kakiuchi; 幸治垣内; Hirotaka Itou; 大貴伊藤
Original assignee: Energy Support Corp
Current assignee: Energy Support Corp
Priority date: 2003-03-06
Filing date: 2003-03-06
Publication date: 2004-09-30

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat storage device capable of reducing influence of weight of a heat storage material upon expansion and shrinkage action of a heat transfer pipe caused by thermal expansion and preventing breakage and failure of the heat transfer pipe by allowing the action. <P>SOLUTION: The heat transfer pipe 14 is meanderingly arranged so as to combine a plurality of U-shaped pipes having a curved part and a straight part. The curved part 20a curving and inverting like U shape in the uppermost stream part of the heat transfer pipe 14 is arranged above an upper face of a mixed heat storage material 13. The straight part 19 is arranged inside the mixed heat storage material 13. For this reason, since the mixed heat storage material 13 is not arranged on an upper face of the curved part 20a, movement of expansion and shrinkage caused in the straight part 19 of the heat transfer pipe 14 in the vertical direction is not regulated by weight from above. Consequently, weight burden of the heat transfer pipe 14 for expansion and shrinkage operation on an outer face can be reduced when compared with a case where it is completely buried into the mixed heat storage material 13. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、比熱の大きな物質に熱を蓄えておき、後でこの蓄熱を利用する蓄熱装置に関するものである。
【０００２】
【従来の技術】
従来より、次のような蓄熱装置が知られている。即ち、蓄熱装置のケース本体内には蓄熱材が充填されている。この蓄熱材には同蓄熱材を加熱するヒータ及び上下方向を含むように蛇行し、かつ湾曲部と直線部とを有する伝熱管がそれぞれ配設されている。そして、前記蓄熱装置は、容器内の蓄熱材をヒータにより加熱した後に伝熱管の一方から水を供給することにより、伝熱管の他方から蓄熱材との間で熱交換した高温の蒸気を取り出している。また、このような蓄熱装置では、水と蓄熱材との間で効率よく熱交換を行うという観点から、水の流入口と流出口を除く伝熱管の全体を蓄熱材の内部に完全に埋設している（例えば、特許文献１参照。）。
【０００３】
【特許文献１】
特開２００２−５５２９号公報（段落番号「００１３」〜「００３２」、第１図）
【０００４】
【発明が解決しようとする課題】
しかし、上記蓄熱装置の伝熱管が埋設されている蓄熱材は、蓄熱容量の確保やコスト低減等の観点から、加熱状態となる蓄熱温度領域で液体化する硝酸塩等からなる液状材の他、加熱状態となる蓄熱温度領域でも固体状態を維持するマグネシア等からなる固体蓄熱材を含む混合蓄熱材とされている。そのため、このような固体蓄熱材を含む混合蓄熱材内に配置された伝熱管は、同混合蓄熱材との摩擦力又はその荷重によって、蓄熱材内での移動が規制されていた。
【０００５】
従って、蓄熱装置の稼動時において熱媒体としての水の流入と停止が繰り返されると、伝熱管は、温度変化による収縮と膨張を繰り返して上下方向へ移動しようとするが、上記した規制により移動できず大きな負荷が伴っていた。その結果、上記伝熱管は、蓄熱装置の実稼働時において、例えば直線部にて湾曲する等の変形が生じる等、外面に大きな負担がかかってしまうという問題があった。
【０００６】
本発明は上記問題点を解決するためになされたものであり、その目的は、伝熱管に対する蓄熱材の荷重を軽減し、その動作を許容することで伝熱管の破損故障を未然に防止することができる蓄熱装置を提供することにある。
【０００７】
【課題を解決するための手段】
上記問題点を解決するために、請求項１に記載の発明は、内部に加熱状態において液状となる液状蓄熱材及び加熱状態においても固体である固体蓄熱材を混合した蓄熱材が充填されたケース本体と、前記蓄熱材を加熱する加熱手段と、上下方向に形成された直線部及び上部にて湾曲反転される湾曲部を含むように蛇行し、前記ケース本体内に配設されると共に内部に熱媒体が流通される伝熱管とを備えた蓄熱装置であって、少なくとも一つの前記湾曲部は、少なくとも上面の一部が前記固体蓄熱材の上面よりも上方に位置された開放湾曲部とされていることを要旨とする。
【０００８】
請求項２に記載の発明は、請求項１に記載の蓄熱装置において、前記湾曲部を複数備え、該湾曲部のうち、少なくとも前記熱媒体の流入に対して最も上流側に配置された湾曲部は、前記開放湾曲部とされていることを要旨とする。
【０００９】
請求項３に記載の発明は、請求項１又は請求項２に記載の蓄熱装置において、前記開放湾曲部は、該開放湾曲部の全体が前記固体蓄熱材の上面から上方に位置していることを要旨とする。
【００１０】
請求項４に記載の発明は、請求項３に記載の蓄熱装置において、前記直線部の一部も前記固体蓄熱材の上面から上方に位置されていることを要旨とする。
【００１１】
【発明の実施の形態】
（第１実施形態）
以下、本発明を具体化した一実施形態を図１及び図２に従って説明する。
【００１２】
図１に示すように、蓄熱装置１１の容器１２は、上部が開口したケース本体１２ａと同ケース本体１２ａの上部開口部を閉鎖する蓋板１２ｂとを備えている。有底四角筒状のケース本体１２ａ内には、固体蓄熱材１３ａと、加熱状態となる蓄熱温度領域で液体化する液状蓄熱材１３ｂとが均等分布して混合された蓄熱材としての混合蓄熱材１３が充填されている。また、ケース本体１２ａには、内部に熱媒体としての水が流通される伝熱管１４の一部が配設されている。
【００１３】
伝熱管１４は、ステンレススチール等から形成され、混合蓄熱材１３内を、直線部１９と湾曲部２０とを有する複数のＵ字管を組み合わせて上下方向を含むように蛇行して配設されている。直線部１９は、伝熱管１４のうち、混合蓄熱材１３内を上下方向に直線状に形成された部分である。湾曲部２０は、伝熱管１４のうち、上部にてＵ字状に湾曲反転する部分である。
【００１４】
そして、図１，２に示すように、伝熱管１４は、複数の直線部１９及び湾曲部２０を備え、ケース本体１２ａの一側面と平行な一平面上に沿って配設されるように複数段（本実施形態では６段）に区分されている。また、伝熱管１４の両端に配置された流入部１４ａ及び流出部１４ｂは、前記蓋板１２ｂを貫通して外部に導出されるとともに、蓋板１２ｂに対して所定の手段により支持されている。
【００１５】
また、湾曲部２０は、ケース本体１２ａの長手方向に沿う湾曲部２０ａ，２０ｂと、ケース本体１２ａの幅方向（長手方向に対して直交する方向）に沿う湾曲部２０ｃとを有している。
【００１６】
湾曲部２０ａは、水の流入に対して最も上流側に位置され、固体蓄熱材１３ａを含む混合蓄熱材１３の上面よりも上方に位置している。すなわち、本実施形態の湾曲部２０ａは、開放湾曲部として形成されている。また特に、本実施形態における開放湾曲部としての湾曲部２０ａは、その全体が混合蓄熱材１３の上面と蓋板１２ｂの下面とで形成される空間１５に配置され混合蓄熱材１３の上面から上方に位置する構成である。そのため、湾曲部２０ａは、その上部に混合蓄熱材１３が配置されないため、同混合蓄熱材１３の荷重を上方から受けるということがない。従って、伝熱管１４は、混合蓄熱材１３に完全に埋設されている伝熱管と比較して上下方向の伸びが規制されにくい構成となっている。
【００１７】
またさらに、本実施形態では、直線部１９のうち、湾曲部２０ａと直結する直線部１９ａは混合蓄熱材１３の内部に配置されている。しかし、直線部１９ａは、直結する湾曲部２０ａが開放湾曲部であるとともに鉛直方向に直線状に配置されているため、混合蓄熱材１３の荷重を上方から受けることなく上下方向に移動し得る。
【００１８】
湾曲部２０ｂは、ケース本体１２ａの長手方向に沿う湾曲部２０のうち、前記湾曲部２０ａを除いた部分である。湾曲部２０ｂは、湾曲部２０ａと異なり、その全体が混合蓄熱材１３の内部に埋設されている。従って、湾曲部２０ｂの内部を流通する熱媒体としての水は、湾曲部２０ａの内部を流通する場合よりも効率よく熱交換することができるようになっている。また、湾曲部２０ｃは、湾曲部２０ｂと配置される方向が直交する点で異なるが、同様な構成である。
【００１９】
図１及び図２に示すように、ケース本体１２ａ内において、前記伝熱管１４の蛇行部間には加熱手段としての複数のヒータ１６が埋設されている。すなわち、ヒータ１６は、前記蓋板１２ｂ（図２にて省略）を貫通してケース本体１２ａ内部に導入され、前記伝熱管１４の蛇行する谷部に挿入するようにして収容されている。そして、ヒータ１６は、混合蓄熱材１３内にてＵ字状に曲折された後、再び前記蓋板１２ｂを貫通して容器１２外部に導出されている。
【００２０】
次に、蓄熱装置１１の作用について説明する。
ヒータ１６が通電されて発熱すると、混合蓄熱材１３が加熱されて熱を蓄える。そして、混合蓄熱材１３が十分に蓄熱すると蓄熱装置１１が稼働する。このような蓄熱装置１１の稼働時においては、負荷装置（図示しない）への蒸気供給の要求に応じて、伝熱管１４に水の流入及び停止が繰り返される。そして、この状態で供給された水は、伝熱管１４を介して混合蓄熱材１３の蓄熱と熱交換され、蒸気として流出部１４ｂから負荷装置へ流出される。
【００２１】
また、このように蓄熱装置１１が稼働する状態では、伝熱管１４は略４５０℃の温度状態となっている。一方で、伝熱管１４に流入される水は略２０℃となっている。従って、直線部１９のうち、特に湾曲部２０ａに直結する直線部１９ａは、流入部１４ａ近辺に位置するため、前記した略２０℃の水がほぼそのままの温度で流通される。
【００２２】
すると、同直線部１９ａは急激に温度低下する。それとともに、直線部１９ａは温度低下に伴って収縮をしようとする。また、このように直線部１９ａが温度低下した状態で水の流入が停止されると、次に直線部１９ａは急激に温度上昇する。それとともに、直線部１９ａは温度上昇に伴って膨張しようとする。すなわち、蓄熱装置１１の稼働時においては、特に加熱前の水が流通される直線部１９ａの温度変化が激しい。従って、同直線部１９ａは、水の流入の有無に応じて比較的大きな収縮又は膨張を繰り返して行おうとする。
【００２３】
そして、本実施形態の直線部１９ａは、温度変化に基づく膨張又は収縮動作を、上方から混合蓄熱材１３の荷重による影響を受けることなく上下方向に伸縮運動等（膨張収縮運動）することにより行う。
【００２４】
これに対し、直線部１９のうち、直線部１９ａを除いた直線部１９は、その内部を流通する蒸気（水）が既に加熱されて混合蓄熱材１３の蓄熱温度に近い過熱温度又は飽和温度となっているため、蒸気（水）の流通の有無に応じて急激に温度変化することはない。そのため、直線部１９のうち、流入部１４ａの近傍に位置する直線部１９ａ以外の直線部１９は、直線部１９ａに比して温度変化が小さく、比較的小さな収縮又は膨張しか行わず負担も小さい。
【００２５】
従って、上記実施形態によれば、以下のような効果を得ることができる。
（１）上記実施形態では、伝熱管１４の湾曲部２０に、その上面の少なくとも一部が混合蓄熱材１３（固体蓄熱材１３ａ）の上面よりも上方に位置した開放湾曲部を湾曲部２０ａとして備えた。
【００２６】
従って、湾曲部２０ａに直結した直線部１９ａは、温度変化に伴う膨張又は収縮において、固体蓄熱材１３ａによる影響が抑制された状態で上下方向に伸縮等することができる。すなわち、伝熱管１４の熱膨張に基因する伸縮動作に対して混合蓄熱材１３の荷重等の影響を軽減し、その動作を許容することで伝熱管１４の破損故障を未然に防止することができる。
【００２７】
（２）また、上記実施形態では、熱媒体としての水の流入に対して最も上流側に配置された湾曲部を、開放湾曲部として設けた。
従って、伝熱管１４のうち、伸縮率が最も高く、負担も最も大きいとされる直線部１９ａの膨張収縮運動を容易にさせることができる。
【００２８】
また、熱媒体としての水の流入に対して最も上流側に配置された湾曲部のみを、開放湾曲部として設けたため、全ての湾曲部２０を開放湾曲部として設ける場合と比較して、伝熱管１４内を流通する熱媒体としての水の熱交換を効率的に行うことができる。
【００２９】
（３）またさらに、上記実施形態では、湾曲部２０ａの全体を混合蓄熱材１３（固体蓄熱材１３ａ）の上面から上方に配置するとともに、空間１５に配置した。
【００３０】
従って、湾曲部２０ａの全体が混合蓄熱材１３の上面より上方に位置しない場合と比較して、上記（１）の効果を大きくすることができる。すなわち、このようにすることにより、直線部１９ａは、固体蓄熱材１３ａの荷重を湾曲部２０ａの上面から受けることなく、上下方向への直線的な膨張収縮運動を行うことができる。
【００３１】
また、湾曲部２０ａは、混合蓄熱材１３内に配置されないが、密閉された高温の空間１５内に位置するため、伝熱管内を流れる水の熱交換効率が下がるのを防止できる。
【００３２】
（４）またさらに、上記実施形態では、湾曲部２０ａを、固体蓄熱材１３ａのみならず、同固体蓄熱材１３ａを含む混合蓄熱材１３の上面よりも上方に位置させた。
【００３３】
従って、直線部１９ａは、混合蓄熱材１３による湾曲部２０ａの上面からの荷重による影響を受けることなく、上下方向への直線的な膨張収縮運動を行うことができる。
【００３４】
（５）上記実施形態では、ヒータ１６を伝熱管１４の蛇行部の谷部に近接して配置した。
従って、蓄熱温度が低下した場合でも、ヒータ１６の加熱動作にて容易に伝熱管１４に熱を与えることができ、追い炊きが可能である。
【００３５】
なお、上記実施形態は以下のような別例に変更して具体化してもよい。
○上記実施形態では、湾曲部２０ａを、その全体が混合蓄熱材１３（固体蓄熱材１３ａ）の上面より上方に位置する開放湾曲部として設けた一方で、直線部１９を混合蓄熱材１３の内部に配置したが、開放湾曲部を備えれば伝熱管１４をどのように配置してもよい。
【００３６】
例えば、図３（ａ）に示すように、湾曲部２０ａの上部の一部のみが、混合蓄熱材１３又は固体蓄熱材１３ａの上面から突出するようにしてもよい。さらに、図３（ｂ），（ｃ）に示すように、湾曲部２０ａの上面の一部のみが、混合蓄熱材１３又は固体蓄熱材１３ａの上面より上方に位置しているものであってもよい。これらの場合であっても、上記実施形態と略同様の効果が得られる。
【００３７】
さらに、図３（ｄ）の実線に示すように、湾曲部２０ａに加えて直線部１９ａの一部が、混合蓄熱材１３の上面より上方に位置していてもよい。特にこの場合にあっては、直線部１９ａ又は湾曲部２０ａにおける上下方向への膨張又は収縮のみならず、図３（ｄ）の２点鎖線に示すように、左右方向への膨張又は収縮が発生しても空間１５にて変形可能である。なお、図３（ｅ）に示すように、湾曲部２０ａの上面の少なくとも一部が、混合蓄熱材１３の上面よりも上方に位置していれば、直線部１９は傾斜していてもよい。
【００３８】
○上記実施形態では、伝熱管１４を、直線部１９及び湾曲部２０を有する複数のＵ字管のみを組み合わされたように形成したが、上下方向を含むように蛇行していれば、水平方向への蛇行とを組み合せたりしてもよい。
【００３９】
○上記実施形態では、ケース本体１２ａを有底四角筒状に形成したが、どのような形状であってもよい。
○上記実施形態では、伝熱管１４の最上流部に位置する湾曲部２０ａのみを、混合蓄熱材１３の上面より上方に位置する開放湾曲部としたが、湾曲部２０ａの他の湾曲部２０も開放湾曲部として形成してもよい。また、いずれかの湾曲部２０が開放湾曲部とされていれば、熱媒体の最上流部に位置する湾曲部２０ａを開放湾曲部としなくてもよい。さらに、図４に示すように、全ての湾曲部２０を、混合蓄熱材１３の上面より上方に位置した開放湾曲部として設けてもよい。
【００４０】
○上記実施形態では、一つのケース本体１２ａ内にのみ配置された伝熱管１４に具体化したが、図５に示す蓄熱装置１１としてもよい。すなわち、蓄熱装置１１は、ケース１７，１８を分離可能に備えている。同ケース１７，１８は、それぞれ混合蓄熱材１３、伝熱管１４及びヒータ１６を備えている。
【００４１】
ケース１７に内装された伝熱管１４の流入部１４ａとケース１８に内装された伝熱管１４の流出部１４ｂとは連結フランジ１４ｃ、１４ｄをもって着脱可能に直列接続されている。ケース１７の伝熱管１４の流出部１４ｂは負荷装置（図示しない）に接続されている。ケース１７は蓄熱装置１１の本体とし、蓄熱容量の大半を負担している。また、ケース１７内の伝熱管１４は、その全体が混合蓄熱材１３内に埋設されている。
【００４２】
ケース１８はケース１７よりも熱媒体の上流側に配置されている。ケース１８内の伝熱管１４は、湾曲部２０のうち、最上流部に位置する湾曲部２０ａのみを混合蓄熱材１３の上面より上方に位置するように配置している。従って、蓄熱装置１１に２つのケースを備えることで、前記実施例と同様の作用効果が得られる。そればかりか、比較的低温の熱媒体が流入される上流側のケース１８に位置することで、急激な温度変化による熱衝撃を受けやすく、破損頻度が高い伝熱管の部分的な交換を容易にできる。そのため、消耗した部分を有する伝熱管１４を小さな単位ごとに交換できる。
【００４３】
○上記実施形態では、蓄熱材を混合蓄熱材１３とし、固体蓄熱材１３ａと液状蓄熱材１３ｂとを均一に分布する状態としたが、湾曲部２０ａの上面の少なくとも一部が、固体蓄熱材１３ａよりも上方に位置すれば、この混合方法に限られるものではない。例えば図６（ａ）〜（ｅ）に示すように、混合蓄熱材１３の上部（上層）に液状蓄熱材１３ｂのみが存在したような場合であって、湾曲部２０ａの上面の少なくとも一部が、固体蓄熱材１３ａの上面よりも上方に位置しているものでもよい。
【００４４】
特にこの場合、直線部１９ａは、湾曲部２０ａの上部に液状蓄熱材１３ｂのみが存在するだけであるため上方からの荷重等による影響を抑制した状態で円滑に動作できる一方で、伝熱管１４内部を流通する熱媒体としての水の熱交換の効率をも向上できる。
【００４５】
【発明の効果】
以上詳述したように、本発明によれば、伝熱管に対する蓄熱材の荷重を軽減し、その動作を許容することで伝熱管の破損故障を未然に防止することができる。
【図面の簡単な説明】
【図１】この発明の蓄熱装置の第１実施形態を示す平断面図。
【図２】図１の蓄熱装置の略体平面図。
【図３】（ａ）、（ｂ）、（ｃ）、（ｄ）、（ｅ）は、この発明の別例における湾曲部を示す概略説明図。
【図４】この発明の蓄熱装置の別例を示す平断面図。
【図５】この発明の蓄熱装置の別例を示す略体平面図。
【図６】（ａ）、（ｂ）、（ｃ）、（ｄ）、（ｅ）は、この発明の蓄熱装置の別例における湾曲部を示す概略説明図。
【符号の説明】
１１…蓄熱装置、１２ａ…ケース本体、１３…蓄熱材としての混合蓄熱材、１３ａ…固体蓄熱材、１３ｂ…液状蓄熱材、１４…伝熱管、１６…加熱手段としてのヒータ、１９…直線部、２０…湾曲部。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heat storage device that stores heat in a substance having a large specific heat, and uses the heat storage later.
[0002]
[Prior art]
Conventionally, the following heat storage devices are known. That is, the heat storage material is filled in the case body of the heat storage device. The heat storage material is provided with a heater for heating the heat storage material and a heat transfer tube meandering in the vertical direction and having a curved portion and a straight portion. Then, the heat storage device supplies water from one of the heat transfer tubes after heating the heat storage material in the container by the heater, thereby taking out high-temperature steam that has exchanged heat with the heat storage material from the other of the heat transfer tubes. I have. Further, in such a heat storage device, from the viewpoint of performing efficient heat exchange between water and the heat storage material, the entire heat transfer tube except for the water inlet and outlet is completely embedded in the heat storage material. (For example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-2002-5529 (paragraph numbers "0013" to "0032", FIG. 1)
[0004]
[Problems to be solved by the invention]
However, the heat storage material in which the heat transfer tubes of the heat storage device are buried is not only a liquid material such as nitrate that is liquefied in a heat storage temperature region where the heating is performed but also a heating material from the viewpoint of securing heat storage capacity and reducing costs. It is a mixed heat storage material including a solid heat storage material made of magnesia or the like that maintains a solid state even in a heat storage temperature range where the state is maintained. Therefore, the movement of the heat transfer tube disposed in the mixed heat storage material including the solid heat storage material in the heat storage material is restricted by the frictional force with the mixed heat storage material or the load thereof.
[0005]
Therefore, when the inflow and stoppage of water as the heat medium are repeated during the operation of the heat storage device, the heat transfer tube attempts to move up and down by repeating contraction and expansion due to temperature change. Large load was accompanied. As a result, the heat transfer tube has a problem that a large load is applied to the outer surface of the heat storage device during actual operation of the heat storage device, for example, a deformation such as bending at a straight portion occurs.
[0006]
The present invention has been made in order to solve the above problems, and an object of the present invention is to reduce the load of a heat storage material on a heat transfer tube and prevent the heat transfer tube from being damaged by allowing its operation. It is an object of the present invention to provide a heat storage device that can perform heat storage.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the invention according to claim 1 is a case in which a heat storage material in which a liquid heat storage material that becomes liquid in a heated state and a solid heat storage material that is solid even in a heated state are filled. The main body, a heating means for heating the heat storage material, meandering to include a straight portion formed in a vertical direction and a curved portion which is curved and inverted at an upper portion, are disposed in the case main body and are internally provided. A heat transfer tube through which a heat medium flows, wherein at least one of the curved portions is an open curved portion in which at least a part of the upper surface is positioned above the upper surface of the solid heat storage material. The gist is that
[0008]
According to a second aspect of the present invention, in the heat storage device according to the first aspect, a plurality of the curved portions are provided, and among the curved portions, a curved portion disposed at least on the most upstream side with respect to the inflow of the heat medium. The gist of the invention is that it is the open curved portion.
[0009]
According to a third aspect of the present invention, in the heat storage device according to the first or second aspect, in the open curved portion, the entire open curved portion is located above an upper surface of the solid heat storage material. Is the gist.
[0010]
According to a fourth aspect of the present invention, in the heat storage device of the third aspect, a part of the linear portion is also located above the upper surface of the solid heat storage material.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
An embodiment of the present invention will be described below with reference to FIGS.
[0012]
As shown in FIG. 1, the container 12 of the heat storage device 11 includes a case main body 12a having an open top and a lid plate 12b for closing an upper opening of the case main body 12a. A mixed heat storage material as a heat storage material in which a solid heat storage material 13a and a liquid heat storage material 13b which is liquefied in a heat storage temperature region in a heated state are uniformly distributed and mixed in a case body 12a having a bottomed square cylindrical shape. 13 are filled. In addition, a part of the heat transfer tube 14 through which water as a heat medium flows is disposed in the case body 12a.
[0013]
The heat transfer tube 14 is formed of stainless steel or the like, and is arranged in the mixed heat storage material 13 in a meandering manner so as to include a vertical direction by combining a plurality of U-shaped tubes having a straight portion 19 and a curved portion 20. I have. The straight portion 19 is a portion of the heat transfer tube 14 that is formed in the mixed heat storage material 13 so as to be linear in the vertical direction. The curved portion 20 is a portion of the heat transfer tube 14 that is curved and inverted in a U-shape at an upper portion.
[0014]
As shown in FIGS. 1 and 2, the heat transfer tube 14 includes a plurality of straight portions 19 and a plurality of curved portions 20, and the plurality of heat transfer tubes 14 are arranged along a plane parallel to one side surface of the case main body 12 a. It is divided into stages (six stages in this embodiment). Further, the inflow portion 14a and the outflow portion 14b arranged at both ends of the heat transfer tube 14 pass through the cover plate 12b and are led out to the outside, and are supported by the cover plate 12b by predetermined means.
[0015]
The bending portion 20 has bending portions 20a and 20b along the longitudinal direction of the case body 12a, and a bending portion 20c along the width direction (a direction orthogonal to the longitudinal direction) of the case body 12a.
[0016]
The curved portion 20a is located on the most upstream side with respect to the inflow of water, and is located above the upper surface of the mixed heat storage material 13 including the solid heat storage material 13a. That is, the bending portion 20a of the present embodiment is formed as an open bending portion. Particularly, the curved portion 20a as the open curved portion in the present embodiment is entirely disposed in the space 15 formed by the upper surface of the mixed heat storage material 13 and the lower surface of the lid plate 12b, and is located above the upper surface of the mixed heat storage material 13. It is a structure located in. Therefore, since the mixed heat storage material 13 is not disposed on the curved portion 20a, the load of the mixed heat storage material 13 is not received from above. Therefore, the heat transfer tube 14 has a configuration in which the elongation in the vertical direction is less restricted than that of the heat transfer tube completely embedded in the mixed heat storage material 13.
[0017]
Furthermore, in the present embodiment, of the straight portions 19, the straight portion 19a directly connected to the curved portion 20a is disposed inside the mixed heat storage material 13. However, the straight portion 19a can move in the vertical direction without receiving the load of the mixed heat storage material 13 from above because the directly connected curved portion 20a is an open curved portion and is linearly arranged in the vertical direction.
[0018]
The curved portion 20b is a portion of the curved portion 20 along the longitudinal direction of the case main body 12a except for the curved portion 20a. The curved portion 20b is different from the curved portion 20a, and is entirely embedded in the mixed heat storage material 13. Therefore, water as a heat medium flowing inside the curved portion 20b can exchange heat more efficiently than when flowing inside the curved portion 20a. The bending portion 20c has a similar configuration, except that the direction in which the bending portion 20b is arranged is orthogonal to that of the bending portion 20b.
[0019]
As shown in FIGS. 1 and 2, a plurality of heaters 16 as heating means are embedded between meandering portions of the heat transfer tubes 14 in the case main body 12a. That is, the heater 16 is introduced into the case body 12a through the cover plate 12b (omitted in FIG. 2), and is housed so as to be inserted into the meandering valley of the heat transfer tube 14. The heater 16 is bent into a U-shape in the mixed heat storage material 13 and then passes through the lid plate 12b again and is led out of the container 12.
[0020]
Next, the operation of the heat storage device 11 will be described.
When the heater 16 is energized and generates heat, the mixed heat storage material 13 is heated and stores heat. Then, when the mixed heat storage material 13 sufficiently stores heat, the heat storage device 11 operates. During the operation of such a heat storage device 11, the flow of water into and out of the heat transfer tube 14 is repeated in response to a request for steam supply to a load device (not shown). Then, the water supplied in this state exchanges heat with the heat stored in the mixed heat storage material 13 through the heat transfer tube 14 and flows out as steam from the outflow portion 14b to the load device.
[0021]
Further, when the heat storage device 11 operates in this manner, the heat transfer tube 14 is at a temperature of approximately 450 ° C. On the other hand, the temperature of the water flowing into the heat transfer tube 14 is approximately 20 ° C. Accordingly, among the straight portions 19, particularly, the straight portion 19a directly connected to the curved portion 20a is located near the inflow portion 14a, so that the above-described water at approximately 20 ° C. flows at substantially the same temperature.
[0022]
Then, the temperature of the straight portion 19a rapidly decreases. At the same time, the linear portion 19a tends to contract as the temperature decreases. Further, when the inflow of water is stopped in a state where the temperature of the linear portion 19a is lowered, the temperature of the linear portion 19a rapidly rises next. At the same time, the linear portion 19a tends to expand as the temperature rises. That is, during the operation of the heat storage device 11, the temperature of the linear portion 19a through which the water before heating flows particularly changes greatly. Therefore, the straight line portion 19a repeatedly performs relatively large contraction or expansion depending on the presence or absence of inflow of water.
[0023]
The linear portion 19a of the present embodiment performs an expansion or contraction operation based on a temperature change by performing a vertical expansion / contraction movement (expansion / contraction movement) without being affected by the load of the mixed heat storage material 13 from above. .
[0024]
On the other hand, among the straight portions 19, the straight portion 19 excluding the straight portion 19 a has a superheat temperature or a saturation temperature close to the heat storage temperature of the mixed heat storage material 13 because the steam (water) flowing through the straight portion 19 is already heated. Therefore, the temperature does not suddenly change depending on the presence or absence of the flow of steam (water). Therefore, among the straight portions 19, the straight portions 19 other than the straight portion 19a located in the vicinity of the inflow portion 14a have a smaller temperature change than the straight portion 19a, and perform only a relatively small contraction or expansion and a small load. .
[0025]
Therefore, according to the above embodiment, the following effects can be obtained.
(1) In the above embodiment, the open curved portion in which at least a part of the upper surface of the curved portion 20 of the heat transfer tube 14 is located above the upper surface of the mixed heat storage material 13 (the solid heat storage material 13a) is defined as the curved portion 20a. Equipped.
[0026]
Therefore, the linear portion 19a directly connected to the curved portion 20a can expand and contract in the vertical direction while the influence of the solid heat storage material 13a is suppressed in expansion or contraction due to a temperature change. That is, the influence of the load of the mixed heat storage material 13 and the like on the expansion and contraction operation caused by the thermal expansion of the heat transfer tube 14 is reduced, and by allowing the operation, damage to the heat transfer tube 14 can be prevented beforehand. .
[0027]
(2) Further, in the above embodiment, the curved portion disposed on the most upstream side with respect to the inflow of water as the heat medium is provided as the open curved portion.
Therefore, of the heat transfer tubes 14, the expansion and contraction movement of the straight portion 19a, which is considered to have the highest expansion ratio and the highest load, can be facilitated.
[0028]
Further, since only the curved portion disposed on the most upstream side with respect to the inflow of water as the heat medium is provided as an open curved portion, the heat transfer tube is compared with a case where all the curved portions 20 are provided as open curved portions. The heat exchange of water as a heat medium flowing through the inside 14 can be performed efficiently.
[0029]
(3) Further, in the above-described embodiment, the entire curved portion 20a is disposed above the upper surface of the mixed heat storage material 13 (the solid heat storage material 13a) and is disposed in the space 15.
[0030]
Therefore, the effect of the above (1) can be enhanced as compared with the case where the entire curved portion 20a is not located above the upper surface of the mixed heat storage material 13. That is, by doing so, the linear portion 19a can perform linear expansion and contraction motion in the vertical direction without receiving the load of the solid heat storage material 13a from the upper surface of the curved portion 20a.
[0031]
Further, the curved portion 20a is not arranged in the mixed heat storage material 13, but is located in the closed high-temperature space 15, so that the heat exchange efficiency of the water flowing in the heat transfer tube can be prevented from lowering.
[0032]
(4) Further, in the above embodiment, the curved portion 20a is located above the upper surface of not only the solid heat storage material 13a but also the mixed heat storage material 13 including the solid heat storage material 13a.
[0033]
Therefore, the linear portion 19a can perform a linear expansion and contraction motion in the vertical direction without being affected by the load from the upper surface of the curved portion 20a due to the mixed heat storage material 13.
[0034]
(5) In the above embodiment, the heater 16 is arranged near the valley of the meandering part of the heat transfer tube 14.
Therefore, even when the heat storage temperature decreases, heat can be easily applied to the heat transfer tube 14 by the heating operation of the heater 16, and additional cooking can be performed.
[0035]
Note that the above-described embodiment may be embodied by changing to another example as described below.
In the above embodiment, the curved portion 20a is provided as an open curved portion which is entirely located above the upper surface of the mixed heat storage material 13 (solid heat storage material 13a), while the straight portion 19 is provided inside the mixed heat storage material 13. However, the heat transfer tube 14 may be arranged in any manner as long as the tube has an open curved portion.
[0036]
For example, as shown in FIG. 3A, only a part of the upper portion of the curved portion 20a may project from the upper surface of the mixed heat storage material 13 or the solid heat storage material 13a. Further, as shown in FIGS. 3B and 3C, only a part of the upper surface of the curved portion 20a is located above the upper surface of the mixed heat storage material 13 or the solid heat storage material 13a. Good. Even in these cases, substantially the same effects as in the above embodiment can be obtained.
[0037]
Further, as shown by the solid line in FIG. 3D, a part of the linear portion 19 a in addition to the curved portion 20 a may be located above the upper surface of the mixed heat storage material 13. Particularly in this case, not only expansion or contraction in the vertical direction in the straight portion 19a or the curved portion 20a, but also expansion or contraction in the horizontal direction occurs as shown by a two-dot chain line in FIG. Even in this case, the space 15 can be deformed. In addition, as shown in FIG. 3E, the linear portion 19 may be inclined as long as at least a part of the upper surface of the curved portion 20 a is located above the upper surface of the mixed heat storage material 13.
[0038]
In the above-described embodiment, the heat transfer tube 14 is formed by combining only a plurality of U-shaped tubes having the straight portion 19 and the curved portion 20. Or the meandering to the sea.
[0039]
In the above embodiment, the case main body 12a is formed in the shape of a square cylinder with a bottom, but may have any shape.
In the above embodiment, only the curved portion 20a located at the most upstream portion of the heat transfer tube 14 is an open curved portion located above the upper surface of the mixed heat storage material 13, but other curved portions 20 of the curved portion 20a are also It may be formed as an open curved portion. If any of the curved portions 20 is an open curved portion, the curved portion 20a located at the most upstream portion of the heat medium does not have to be an open curved portion. Further, as shown in FIG. 4, all the curved portions 20 may be provided as open curved portions located above the upper surface of the mixed heat storage material 13.
[0040]
In the above embodiment, the heat transfer tube 14 is embodied only in one case main body 12a, but may be the heat storage device 11 shown in FIG. That is, the heat storage device 11 includes the cases 17 and 18 in a separable manner. The cases 17 and 18 include a mixed heat storage material 13, a heat transfer tube 14, and a heater 16, respectively.
[0041]
The inflow portion 14a of the heat transfer tube 14 housed in the case 17 and the outflow portion 14b of the heat transfer tube 14 housed in the case 18 are detachably connected in series with connecting flanges 14c and 14d. Outflow portion 14b of heat transfer tube 14 of case 17 is connected to a load device (not shown). The case 17 is the main body of the heat storage device 11 and bears most of the heat storage capacity. The entire heat transfer tube 14 in the case 17 is embedded in the mixed heat storage material 13.
[0042]
The case 18 is arranged on the upstream side of the heat medium from the case 17. The heat transfer tube 14 in the case 18 is arranged such that only the curved portion 20 a located at the most upstream portion of the curved portion 20 is located above the upper surface of the mixed heat storage material 13. Therefore, by providing the heat storage device 11 with two cases, the same operation and effect as in the above embodiment can be obtained. In addition, by being located in the upstream case 18 into which the relatively low-temperature heat medium flows, it is easily affected by a thermal shock due to a rapid temperature change, and it is easy to partially replace a heat transfer tube that is frequently damaged. it can. Therefore, the heat transfer tube 14 having the consumed portion can be replaced in small units.
[0043]
In the above-described embodiment, the heat storage material is the mixed heat storage material 13, and the solid heat storage material 13a and the liquid heat storage material 13b are uniformly distributed. However, at least a part of the upper surface of the curved portion 20a has the solid heat storage material 13a. If it is located above, it is not limited to this mixing method. For example, as shown in FIGS. 6A to 6E, a case where only the liquid heat storage material 13b is present on the upper part (upper layer) of the mixed heat storage material 13 and at least a part of the upper surface of the curved portion 20a is formed. Alternatively, a material located above the upper surface of the solid heat storage material 13a may be used.
[0044]
In particular, in this case, the linear portion 19a can operate smoothly in a state where the influence of the load or the like from above is suppressed because only the liquid heat storage material 13b exists only above the curved portion 20a. Can also improve the efficiency of heat exchange of water as a heat medium flowing through.
[0045]
【The invention's effect】
As described above in detail, according to the present invention, the load of the heat storage material on the heat transfer tube is reduced, and the operation thereof is allowed to prevent the failure of the heat transfer tube from occurring.
[Brief description of the drawings]
FIG. 1 is a cross-sectional plan view showing a first embodiment of a heat storage device of the present invention.
FIG. 2 is a schematic plan view of the heat storage device of FIG.
FIGS. 3 (a), (b), (c), (d), and (e) are schematic illustrations showing a curved portion in another example of the present invention.
FIG. 4 is a plan sectional view showing another example of the heat storage device of the present invention.
FIG. 5 is a schematic plan view showing another example of the heat storage device of the present invention.
FIGS. 6 (a), (b), (c), (d), and (e) are schematic explanatory views showing a curved portion in another example of the heat storage device of the present invention.
[Explanation of symbols]
11: heat storage device, 12a: case body, 13: mixed heat storage material as heat storage material, 13a: solid heat storage material, 13b: liquid heat storage material, 14: heat transfer tube, 16: heater as heating means, 19: linear part, 20 ... bending part.

Claims

A case body filled with a heat storage material mixed with a liquid heat storage material that becomes liquid in a heated state and a solid heat storage material that is solid even in a heated state,
Heating means for heating the heat storage material,
A heat storage device that has a heat transfer tube that is meandering so as to include a linear portion formed in the vertical direction and a curved portion that is curved and inverted at the upper portion, is provided in the case body, and has a heat medium circulated therein. A device,
The heat storage device, wherein at least one of the curved portions is an open curved portion in which at least a part of an upper surface is located above an upper surface of the solid heat storage material.

Comprising a plurality of said curved portions,
2. The heat storage device according to claim 1, wherein at least the curved portion of the curved portion disposed at the most upstream side with respect to the inflow of the heat medium is the open curved portion. 3.

3. The heat storage device according to claim 1, wherein the open curved portion has the entire open curved portion located above an upper surface of the solid heat storage material. 4.

4. The heat storage device according to claim 3, wherein a part of the linear portion is also located above an upper surface of the solid heat storage material. 5.