JP4134359B2

JP4134359B2 - Battery cooling device

Info

Publication number: JP4134359B2
Application number: JP19292397A
Authority: JP
Inventors: 伸本田; 隆久鈴木; 彰久小久保; 慶一郎伴在
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 1997-07-17
Filing date: 1997-07-17
Publication date: 2008-08-20
Anticipated expiration: 2017-07-17
Also published as: JPH1140211A

Description

【０００１】
【発明の属する技術分野】
本発明は、電池（蓄電池）の冷却装置に関するもので、電気自動車、ハイブリッド車等の車両に搭載される電池の冷却に用いて好適なものである。
【０００２】
【従来の技術】
電気自動車、ハイブリッド車等の車両に搭載される電池は、車両走行用電動モータの電源となるため、高圧化、大容量化する必要がある。ところで、このような車載の電池において、充放電の際には各電池での化学反応やジュール損により熱が発生し、電池が高温化して、電池の性能、寿命等に悪影響を及ぼす。
【０００３】
そこで、従来、電池を冷却する冷却装置として、種々なものが提案されている。例えば、特開平５−３４４６０６号公報では、車両空調用冷凍サイクルの低圧側冷媒が流入する密閉ケース内に電池を収容して、低圧側冷媒の蒸発潜熱を電池から吸熱することにより電池を冷却するものが提案されている。
【０００４】
【発明が解決しようとする課題】
ところで、車載の電池、具体的には、ニッケル水素系の電池では、電池の高温化等により水素ガスを発生するので、電池の内圧が徐々に上昇していく。そのため、安全弁としてのリリーフ弁を電池に備えている。従って、電池内圧が所定値に到達して、リリーフ弁が開弁すると、電池内部の水素ガスが密閉ケース内に放出される。
【０００５】
ここで、水素ガスは冷凍サイクルの冷媒に比して沸点が非常に低く、冷凍サイクル内では水素ガスが不凝縮ガスとして作用するため、密閉ケース内に水素ガスが放出され、サイクル内に水素ガスが蓄積され、水素ガス量が増加すると、電池の冷却効果およびサイクル本来の冷房効果をも低下させるという不具合を生じる。
【０００６】
また、水素ガスは引火性のガスであるため、電池や冷凍サイクルの保守点検等の際に、冷凍サイクルを開放すると、今まで蓄積されていた水素ガスが一度にサイクル外部に放出され、危険である。
本発明は上記点に鑑み、電池で発生する水素ガスが、外部と密閉された冷媒系路内に放出されることに起因する不具合を解消することを目的とする。
【０００７】
【課題を解決するための手段】
上記目的を達成するため、本発明は以下の技術的手段を採用する。すなわち、請求項１記載の発明では、ニッケル水素系の電池（１３）を収容する密閉ケース（１０）と、この密閉ケース（１０）の内部と連通する放熱器（２２、３１）とを備え、密閉ケース（１０）および放熱器（２２、３１）を含む閉回路からなる冷媒系路内に冷媒が充填されており、この冷媒が密閉ケース（１０）の内部で、電池（１３）から吸熱して蒸発することにより電池（１３）を冷却し、この蒸発したガス冷媒が放熱器（２２、３１）で放熱して凝縮し、この凝縮した液冷媒が密閉ケース内に流入するようになっており、さらに、電池（１３）から発生する水素ガスを選択的に吸着する吸着部材（２１）を、冷媒系路のうちガス冷媒が流れる、もしくは、ガス冷媒が集まるガス域に備えたことを特徴としている。
【０００８】
これによると、電池（１３）から冷媒の蒸発潜熱を奪って、電池（１３）を冷却する際に、冷媒は密閉ケース（１０）の内部空間にて電池（１３）のほぼ全表面と直接的に接触しているので、冷却効果が大きい。
しかも、冷媒系路のガス域に備えた吸着部材（２１）により水素ガスを選択的に吸着できるから、冷媒系路内に不凝縮性ガスである水素ガスが蓄積するのを防止して、水素ガスによる電池冷却効果の低下を未然に防止できる。また、保守点検時等に、冷媒系路内に溜まった水素ガスが一度に放出されるという危険も解消できる。
【０００９】
また、請求項２記載の発明では、ニッケル水素系の電池（１３）を収容する密閉ケース（１０）と、この密閉ケース（１０）の内部と連通する放熱器（２２）と、密閉ケース（１０）と放熱器（２２）とを連通させて、ガス冷媒の流路を構成するガス側連通パイプ（２０）と、密閉ケース（１０）と放熱器（２２）とを連通させて、液冷媒の流路を構成する液側連通パイプ（２３）とを備え、密閉ケース（１０）、放熱器（２２）、ガス側連通パイプ（２０）および液側連通パイプ（２３）を含む冷媒系路内に冷媒が充填されており、放熱器（２２）は密閉ケース（１０）の内部の液冷媒よりも上方側に配置されており、密閉ケース（１０）の内部で、電池（１３）から吸熱して冷媒が蒸発し、この蒸発したガス冷媒が自然対流にてガス側連通パイプ（２０）を上昇して放熱器（２２）に流入し、放熱器（２２）でガス冷媒が冷却され凝縮し、この凝縮した液冷媒が自重にて液側連通パイプ（２３）を下降して密閉ケース（１０）内部の電池（１３）周辺に還流するようになっており、さらに、電池（１３）から発生する水素ガスを選択的に吸着する吸着部材（２１）をガス側連通パイプ（２０）に備えたことを特徴としている。
【００１０】
これによると、熱サイフォン式の冷却装置にて電池（１３）を良好に冷却できる。また、水素ガスについては、請求項１と同様に、吸着部材（２１）により吸着できる。
また、請求項３記載の発明では、ニッケル水素系の電池（１３）を収容する密閉ケース（１０）の内部を冷凍サイクルの低圧側冷媒が流れる通路に接続して、この低圧側冷媒が電池（１３）から吸熱して蒸発するようにし、さらに、密閉ケース（１０）内部のガス冷媒が集まるガス域を含む、冷凍サイクルのうちガス冷媒が流れる、もしくは、ガス冷媒が集まるガス域のいずれかに、電池（１３）から発生する水素ガスを選択的に吸着する吸着部材（２１）を備えたことを特徴としている。
【００１１】
これによると、空調用冷凍サイクルの低温冷媒を利用して、電池（１３）と冷媒との温度差を増大させて、冷却性能を格段と向上できる。水素ガスについては、請求項１、２と同様に、吸着部材（２１）により吸着できる。
なお、吸着部材（２１）は、請求項４記載のように、ゼオライトまたは水素吸蔵合金からなる吸着材（２１ａ）を用いて構成できる。
【００１２】
また、請求項２記載の発明の放熱器（２２）は、請求項５のように空気と熱交換してガス冷媒を冷却し、凝縮させる空冷式熱交換器で構成することができる。これによると、ガス冷媒を強制送風による空冷方式にて良好に冷却できるので、
また、請求項６記載の発明では、ニッケル水素系の電池（１３）を収容する密閉ケース（１０）と、この密閉ケース（１０）の内部と連通する放熱器（２２、３１）とを備え、密閉ケース（１０）および放熱器（２２、３１）を含む閉回路からなる冷媒系路内に冷媒が充填されており、この冷媒が密閉ケース（１０）の内部で、電池（１３）から吸熱して蒸発することにより電池（１３）を冷却し、この蒸発したガス冷媒が放熱器（２２、３１）で放熱して凝縮し、この凝縮した液冷媒が密閉ケース内に流入するようになっており、さらに、電池（１３）から発生する水素ガスを選択的に透過する透過部材（２６）を、冷媒系路のうちガス冷媒が流れる、もしくは、ガス冷媒が集まるガス域に備え、水素ガスを透過部材（２６）を通して冷媒系路の外部に放出することを特徴としている。
【００１３】
これによると、電池（１３）から冷媒の蒸発潜熱を奪って、電池（１３）を良好に冷却できるとともに、電池（１３）から発生する水素ガスを透過部材（２６）を通して冷媒系路外に放出できるので、冷媒系路内に水素ガスが溜まることがなく、冷媒系路内への水素ガスの蓄積による冷却効果の低下等の不具合を確実に防止できる。
【００１４】
また、請求項７記載の発明のように、透過部材（２６）を加熱する加熱手段（２６ｃ）を備えれば、透過部材（２６）による水素ガスの透過量を増大できる。そのため、電池（１３）の過酷な使用条件下において水素ガスの発生量が増大しても、これに対応して水素ガスを透過させることができる。
透過部材（２６）は、請求項８に記載のようにパラジウムからなる管状体（２６ｂ）を用いて構成できる。
【００１５】
なお、上記各手段に付した括弧内の符号は、後述する実施形態記載の具体的手段との対応関係を示すものである。
【００１６】
【発明の実施の形態】
以下、本発明の実施形態を図に基づいて説明する。
（第１実施形態）
図１は第１実施形態を示すもので、密閉ケース１０は、ケース本体１１と、このケース本体１１の上方開口端を気密に閉塞する上蓋１２とから構成されている。ここで、ケース本体１１と上蓋１２は、適宜の金属または樹脂にて形成されており、その全体形状は上下方向に縦長の円筒または多角形状となっている。
【００１７】
密閉ケース１０の内部には、車載電源となる電池１３が収容されている。このの電池１３の正極側および負極側の端子１３ａ、１３ｂには出力配線１４、１５が電気的に接続されている。
上蓋１２には密封端子１６、１７がハーメチックシール構造にて気密に装着されており、この密封端子１６、１７を通して出力配線１４、１５は、密閉ケース１０の外部の電気配線と電気的に接続可能になっている。従って、密封端子１６、１７から電池１３の電力を取り出すことができる。
【００１８】
上記の電池１４は再充電可能な二次電池（蓄電池）であり、具体的には、ニッケル水素電池である。このニッケル水素電池は、電池温度が高温（例えば、４５°Ｃ以上）になると、電池内部に発生した水素ガスを電池内部で吸収しきれず、内圧が上昇する。そこで、電池内圧が所定値に上昇すると開弁するリリーフ弁１８が電池１３の上部に備えられている。このリリーフ弁１８は電池内圧が所定値に上昇すると、弁体（図示せず）がバネ手段（図示せず）のバネ力に抗して変位して、電池１３の内部を外部に開放する構成である。
【００１９】
ところで、上蓋１２の中央部に開口部１９が開けてあり、この開口部１９にガス側連通パイプ２０が上方に立ち上がるように接続されている。このガス側連通パイプ２０の途中には後述の吸着部材２１が配置されている。ガス側連通パイプ２０は、放熱器２２の一端側に接続され、この放熱器２２の他端側は液側連通パイプ２３を介して密閉ケース１０のケース本体１１の底部近傍に開けられた開口部２４に接続されている。
【００２０】
従って、密閉ケース１０の内部と放熱器２２は、ガス側連通パイプ２０と液側連通パイプ２３を介して連通された１つの閉回路からなる冷媒系路を構成しており、この冷媒系路内には熱サイフォン式冷却装置の作動流体としての冷媒が充填され、封入されている。この冷媒としては、フロリナート等の不燃性の低沸点冷媒を用いる。密閉ケース１０の内部において、Ａは冷媒の液面を示しており、密閉ケース１０と放熱器２２との間での冷媒の循環を良好にするために、放熱器２２はこの冷媒液面Ａより上方側に配置されている。
【００２１】
上記の両連通パイプ２０、２３はアルミニウム等の金属または樹脂で形成することができ、また、放熱器２２は熱の伝導性、耐食性等に優れたアルミニウム等の金属からなるチューブ２２ａを有し、このチューブ２２ａ内部の冷媒と冷却空気との間の熱の授受を促進するためのプレート状のフィン部材２２ｂが設けてある。このフィン部材２２ｂもアルミニウム等の金属からなる。
【００２２】
本例の放熱器２２は送風機２５により送風される空気（外気）との間で熱交換を行う空冷方式として構成されている。送風機２５は駆動用モータ２５ａと、このモータ２５ａにより回転駆動される送風ファン２５ｂとにより構成されている。
前記した吸着部材２１は、電池１３から発生する水素ガスを選択的に吸着する吸着材２１ａをケース２１ｂ内に収容したものである。ここで、吸着材２１ａは例えば、粒状のゼオライトからなる。
【００２３】
次に、上記構成において作動を説明すると、電池１３の化学反応や放電時のジュール損失等により電池１３の温度が上昇すると、密閉ケース１０の内部空間に充填されている液冷媒は電池１３から速やかに吸熱して沸騰し、ガス化する。
従って、電池１３から冷媒の蒸発潜熱を奪って、電池１３を冷却できる。しかも、冷媒は密閉ケース１０の内部空間にて電池１３のほぼ全表面と直接的に接触しているので、冷却効果が大きい。そして、密閉ケース１０の内部空間でガス化した冷媒は密度の減少により自然対流でガス側連通パイプ２０を上昇して、吸着部材２１のケース２１ｂ内を通過して放熱器２２に流入する。この放熱器２２においてガス冷媒は送風機２５により送風される空気（外気）との間で熱交換を行って冷却され、凝縮する。凝縮した液冷媒は密度の増大により自重にて液側連通パイプ２３を下降して密閉ケース１０の内部空間に還流し、再度、電池１３の冷却作用に供される。
【００２４】
ところで、電池１３では、過充電等の際には電池内部での発生ガス（水素ガス）を吸収しきれず、電池内圧が上昇するので、リリーフ弁１８が開弁して、電池１３の外部へ水素ガスが洩れ出てくることがある。
しかし、本実施形態によると、ガス側連通パイプ２０の途中に吸着部材２１が配設してあり、かつ、吸着部材２１に備えられている吸着材２１ａはゼオライトのように分子ふるい機能を持つため、分子径の大きいフロリナートのような分子は吸着せず、水素ガス等の分子径の小さい分子を選択的に捕捉できる。この結果、冷媒系路内に水素ガスが蓄積するのを防止できるので、電池１３の電極劣化等に伴う保守点検の際に密閉ケース１０内を開放しても、多量の水素ガス等が一度に大気中に放出されることがない。
【００２５】
また、水素ガスは、熱サイフォン式冷却装置の冷媒であるフロリナートに比して沸点が非常に低く、熱サイフォン式冷却装置の冷媒系路内では水素ガスが不凝縮ガスとして作用するため、密閉ケース１０内に水素ガスが放出され、冷媒系路内の水素ガス量が増加すると、電池の冷却効果を低下させることになるが、本実施形態によると、吸着部材２１の水素ガス吸着作用により、このような不具合をも回避でき、電池の冷却作用を長期にわたって良好に維持できる。
【００２６】
一方、熱サイフォン式冷却装置の冷媒として、フロリナート等の低沸点冷媒を使用することにより、密閉ケース１０の内部圧力（作動流体圧力）を引き下げて、密閉ケース１０の低強度設計を実現して、密閉ケース１０のコスト低減を図ることができる。具体的には、フロリナートの作動圧は、常用３５〜７０ｋＰａ（大気圧の１／２近辺）で、沸点は約５６°Ｃである。
【００２７】
また、フロリナート等の低沸点冷媒は不燃性であるので、電池１３で発生するガスの洩れに対する引火の危険を回避でき、安全性を向上できる。
（第２実施形態）
図２は第２実施形態であり、第１実施形態における吸着部材２１の代わりに、電池１３から発生する水素ガスを選択的に透過する透過部材２６を設置するものである。
【００２８】
すなわち、透過部材２６は、水素透過性が優れているパラジウムを用いるものであって、ガス側連通パイプ２０の上方側に、このパイプ２０の内部に連通するケース２６ａを設置し、このケース２６ａの内部を貫通するように管状体２６ｂを配設している。この管状体２６ｂはパラジウムで形成されており、その両端部はケース２６ａの外部で大気中に開放されている。
【００２９】
第２実施形態によると、冷媒系路内に混入した水素ガスは、冷媒系路の最上部に位置するケース２６ａ内に流入する。そして、管状体２６ｂを構成するパラジウムは水素透過性が優れているため、冷媒であるフロリナート等は透過せず、水素ガスのみを選択的に透過し、管状体２６ｂの両端開口部から系路外に排出できる。
【００３０】
（第３実施形態）
図３は第３実施形態であり、第２実施形態をより効果的に実施するものである。パラジウムは高温に加熱されると、水素透過性が向上する特性を持っていることに着目して、透過部材２６に加熱手段としての電気ヒータ２６ｃを追加設置したものである。
【００３１】
第３実施形態によると、電気ヒータ２６ｃに通電して、パラジウムからなる管状体２６ｂを高温に加熱することにより、水素ガスの透過量を増大できる。従って、電池１３の過酷な使用環境下のように水素ガスの発生量が多いときでも、パラジウムからなる管状体２６ｂにおける水素ガスの透過量を増大して、冷媒系路内に水素が残存するのを防止できる。
【００３２】
なお、加熱手段として、電気ヒータ２６ｃの代わりに、温水が循環する温水パイプ等を使用してもよい。
（第４実施形態）
図４は第４実施形態であり、上記した第１〜第３実施形態では熱サイフォン式の冷却装置にて電池１３を冷却する方式について説明したが、第４実施形態は車両空調用冷凍サイクルの低圧側冷媒の冷熱により電池１３を冷却するように構成している。
【００３３】
図４において、圧縮機３０は冷凍サイクルの冷媒（例えば、ＨＦＣ−１３４ａ）を圧縮し、吐出するもので、圧縮機３０から吐出された高温高圧の過熱ガス冷媒は凝縮器３１で冷却されて凝縮する。この凝縮後の冷媒は受液器３２で気液分離され、液冷媒は温度式膨張弁（減圧手段）３３で低温低圧の気液２相冷媒に減圧される。そして、この気液２相冷媒は蒸発器３４にて空調用送風機（図示せず）により送風される空調空気から吸熱して蒸発してガス化し、そのガス冷媒は圧縮機３０に吸入され、再度、圧縮される。
【００３４】
このような車両空調用冷凍サイクルに対して、第４実施形態の電池冷却装置では温度式膨張弁３３の下流側と蒸発器３４の上流側との間の冷媒通路に、電池１３を収容した密閉ケース１０を設置している。この密閉ケース１０の内部の下方側に、温度式膨張弁３３で減圧された気液２相冷媒のうち、液冷媒が溜まる液冷媒域Ｂが形成され、密閉ケース１０の内部上方側には気液２相冷媒のガス冷媒が集まり、ガス域Ｃを形成する。
【００３５】
電池１３の下方側は、密閉ケース１０の内部で液冷媒域Ｂに浸漬するように配置されている。そして、図４に示す例では、水素ガスを吸着する吸着部材２１を密閉ケース１０の上蓋１２の内側面に配設して、吸着部材２１を密閉ケース１０内部のガス域Ｃに位置させている。
第４実施形態によると、車両空調用冷凍サイクルにおいて温度式膨張弁３３で減圧された低温低圧の気液２相冷媒が密閉ケース１０の内部に流入し、ここで、低圧側液冷媒の一部が電池１３から吸熱して蒸発する。そのため、この冷媒の蒸発潜熱で電池１３を冷却できる。ここで、電池１３を冷却する冷却媒体として、空調用冷凍サイクルの低温冷媒を使用しているので、電池１３と低温冷媒との間で非常に大きな温度差を設定でき、電池１３の冷却能力を格段と向上できる。
【００３６】
なお、車両空調用冷凍サイクルがヒートポンプとして構成されている場合には、冬期の暖房時に、冷凍サイクル側の冷媒が密閉ケース１０の内部で吸熱することにより、廃熱回収を行って、冬期の暖房能力を高めることができる。密閉ケース１０を通過した冷媒のうち、残余の液冷媒が空調用蒸発器３４で蒸発して空調空気を冷却する。
【００３７】
一方、密閉ケース１０内の電池１３から発生した水素ガスは、密閉ケース１０内上方のガス域Ｃに設置された吸着部材２１により選択的に吸着される。
なお、第４実施形態では吸着部材２１を密閉ケース１０内上方のガス域Ｃに設置しているが、吸着部材２１はガス域であれば、どこでも水素ガスの吸着作用を発揮し得るので、吸着部材２１を密閉ケース１０の外部のガス域、すなわち、圧縮機３０の吸入側部位Ｄ、圧縮機３０の吐出側部位Ｅ、受液器３２内部のガス域Ｆ等に設置することができる。要は、冷凍サイクル中のガス域であれば、どこに吸着部材２１を設置してもよい。
【００３８】
また、上記各実施形態では、吸着部材２１の吸着材２１ａとしてゼオライトを使用しているが、ゼオライトの他に、水素吸蔵合金のように水素ガスを多量に吸着し得るものであれば、吸着材２１ａとして使用できる。
【図面の簡単な説明】
【図１】本発明の第１実施形態を示す全体システムの構成図である。
【図２】本発明の第２実施形態を示す全体システムの構成図である。
【図３】本発明の第３実施形態を示す要部構成図である。
【図４】本発明の第４実施形態を示す冷凍サイクル図である。
【符号の説明】
１０…密閉ケース、１３…電池、２１…吸着部材、２２…放熱器、
２６…透過部材、３３…温度式膨張弁、３４…蒸発器。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a battery (storage battery) cooling device, and is suitable for cooling a battery mounted on a vehicle such as an electric vehicle or a hybrid vehicle.
[0002]
[Prior art]
A battery mounted on a vehicle such as an electric vehicle or a hybrid vehicle serves as a power source for an electric motor for driving the vehicle, and therefore needs to be increased in voltage and capacity. By the way, in such an in-vehicle battery, heat is generated due to a chemical reaction or Joule loss in each battery during charging and discharging, and the temperature of the battery is increased, which adversely affects the performance and life of the battery.
[0003]
Thus, various types of cooling devices for cooling the battery have been proposed. For example, in Japanese Patent Laid-Open No. 5-344606, a battery is housed in a sealed case into which a low-pressure refrigerant flows in a refrigeration cycle for vehicle air conditioning, and the battery is cooled by absorbing the latent heat of evaporation of the low-pressure refrigerant from the battery. Things have been proposed.
[0004]
[Problems to be solved by the invention]
By the way, in-vehicle batteries, specifically, nickel-metal hydride batteries, generate hydrogen gas due to the high temperature of the batteries, and the internal pressure of the battery gradually increases. Therefore, the battery is provided with a relief valve as a safety valve. Therefore, when the battery internal pressure reaches a predetermined value and the relief valve is opened, hydrogen gas inside the battery is released into the sealed case.
[0005]
Here, hydrogen gas has a very low boiling point compared to the refrigerant in the refrigeration cycle, and hydrogen gas acts as a non-condensable gas in the refrigeration cycle, so that hydrogen gas is released into the sealed case, and the hydrogen gas in the cycle When the amount of hydrogen gas is accumulated and the amount of hydrogen gas increases, the cooling effect of the battery and the original cooling effect of the cycle are deteriorated.
[0006]
Also, since hydrogen gas is a flammable gas, if the refrigeration cycle is opened during maintenance and inspection of the battery or refrigeration cycle, the hydrogen gas accumulated up to now will be released to the outside of the cycle at a dangerous time. is there.
The present invention has been made in view of the above points, and it is an object of the present invention to eliminate problems caused by the release of hydrogen gas generated in a battery into a refrigerant system path sealed from the outside.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention employs the following technical means. That is, the invention according to claim 1 includes a sealed case (10) that houses a nickel metal hydride battery (13), and a radiator (22, 31) that communicates with the inside of the sealed case (10). Refrigerant is filled in a refrigerant system path including a closed circuit including the sealed case (10) and the radiators (22, 31) , and the refrigerant absorbs heat from the battery (13) inside the sealed case (10). The battery (13) is cooled by evaporating, and the evaporated gas refrigerant dissipates heat in the radiator (22, 31) and condenses, and the condensed liquid refrigerant flows into the sealed case. Further, the adsorbing member (21) that selectively adsorbs hydrogen gas generated from the battery (13) is provided in a gas region where the gas refrigerant flows or the gas refrigerant collects in the refrigerant system. Yes.
[0008]
According to this, when taking away the latent heat of vaporization of the refrigerant from the battery (13) and cooling the battery (13), the refrigerant is directly applied to almost the entire surface of the battery (13) in the internal space of the sealed case (10). Because it is in contact with, the cooling effect is great.
Moreover, since the hydrogen gas can be selectively adsorbed by the adsorbing member (21) provided in the gas region of the refrigerant system path, the accumulation of hydrogen gas, which is a non-condensable gas, in the refrigerant system path is prevented. It is possible to prevent the battery cooling effect from being lowered by gas. In addition, it is possible to eliminate the danger that hydrogen gas accumulated in the refrigerant system passage is released at a time during maintenance and inspection.
[0009]
According to the second aspect of the present invention, a sealed case (10) that houses a nickel metal hydride battery (13), a radiator (22) that communicates with the inside of the sealed case (10 ), and a sealed case (10 ) And the radiator (22), the gas side communication pipe (20) constituting the flow path of the gas refrigerant, the sealed case (10), and the radiator (22) are communicated, and the liquid refrigerant A liquid side communication pipe (23) constituting a flow path, and in a refrigerant system path including a sealed case (10) , a radiator (22) , a gas side communication pipe (20), and a liquid side communication pipe (23). The refrigerant is filled, and the radiator (22) is disposed above the liquid refrigerant inside the sealed case (10), and absorbs heat from the battery (13) inside the sealed case (10). the refrigerant evaporates, the gas side the evaporated gas refrigerant at natural convection Rises a through pipe (20) flows into the radiator (22), gas refrigerant is cooled in the radiator (22) condensed, lower the liquid side communication pipe The condensed liquid refrigerant in the self-weight (23) and it is adapted to reflux the battery (13) near the inside the sealed casing (10), further, the adsorption member (21) of the gas side communication pipe which selectively adsorb hydrogen gas generated from the battery (13) (20) is provided.
[0010]
According to this, the battery (13) can be satisfactorily cooled by the thermosyphon cooling device. Further, hydrogen gas can be adsorbed by the adsorbing member (21) as in the first aspect.
According to a third aspect of the present invention, the inside of the sealed case (10) containing the nickel metal hydride battery (13) is connected to a passage through which the low-pressure side refrigerant of the refrigeration cycle flows, and the low-pressure side refrigerant is connected to the battery ( 13) which absorbs heat and evaporates, and further includes a gas region in which the gas refrigerant in the sealed case (10) collects , and either in the gas region in which the gas refrigerant flows in the refrigeration cycle or in which the gas refrigerant collects. And an adsorption member (21) for selectively adsorbing hydrogen gas generated from the battery (13).
[0011]
According to this, the temperature difference between the battery (13) and the refrigerant can be increased by using the low-temperature refrigerant of the air-conditioning refrigeration cycle, and the cooling performance can be remarkably improved. Hydrogen gas can be adsorbed by the adsorbing member (21) as in the first and second aspects.
The adsorbing member (21) can be constituted by using an adsorbent (21a) made of zeolite or a hydrogen storage alloy as described in claim 4.
[0012]
Moreover, the heat radiator (22) of the invention described in claim 2 can be constituted by an air-cooled heat exchanger that exchanges heat with air to cool and condense the gas refrigerant as in claim 5. According to this, the gas refrigerant can be cooled well by the air cooling method by forced air blowing,
Further, the invention according to claim 6 includes a sealed case (10) for housing the nickel metal hydride battery (13), and a radiator (22, 31) communicating with the inside of the sealed case (10), Refrigerant is filled in a refrigerant system path including a closed circuit including the sealed case (10) and the radiators (22, 31) , and the refrigerant absorbs heat from the battery (13) inside the sealed case (10). The battery (13) is cooled by evaporating, and the evaporated gas refrigerant dissipates heat in the radiator (22, 31) and condenses, and the condensed liquid refrigerant flows into the sealed case. Furthermore, a permeation member (26) that selectively permeates hydrogen gas generated from the battery (13) is provided in a gas region in the refrigerant system where gas refrigerant flows or gas refrigerant collects , and transmits hydrogen gas. Refrigerant through member (26) It is characterized by releasing to the outside of the road.
[0013]
According to this, the latent heat of vaporization of the refrigerant is taken from the battery (13), and the battery (13) can be cooled well, and the hydrogen gas generated from the battery (13) is released out of the refrigerant system path through the permeable member (26). Therefore, hydrogen gas does not accumulate in the refrigerant system path, and problems such as a decrease in cooling effect due to accumulation of hydrogen gas in the refrigerant system path can be reliably prevented.
[0014]
Further, if the heating means (26c) for heating the permeable member (26) is provided as in the seventh aspect of the invention, the amount of hydrogen gas permeated by the permeable member (26) can be increased. Therefore, even if the generation amount of hydrogen gas increases under the severe use conditions of the battery (13), hydrogen gas can be permeated accordingly.
The transmissive member (26) can be configured using a tubular body (26b) made of palladium as described in claim 8.
[0015]
In addition, the code | symbol in the parenthesis attached | subjected to each said means shows the correspondence with the specific means of embodiment description later mentioned.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 shows a first embodiment. A sealed case 10 includes a case body 11 and an upper lid 12 that airtightly closes an upper opening end of the case body 11. Here, the case main body 11 and the upper lid 12 are formed of an appropriate metal or resin, and the overall shape thereof is a vertically long cylinder or polygonal shape in the vertical direction.
[0017]
A battery 13 serving as an in-vehicle power source is accommodated in the sealed case 10. Output wirings 14 and 15 are electrically connected to the positive and negative terminals 13a and 13b of the battery 13, respectively.
Sealing terminals 16 and 17 are hermetically sealed in the upper lid 12 in a hermetic seal structure, and the output wirings 14 and 15 can be electrically connected to external electrical wiring of the sealing case 10 through the sealing terminals 16 and 17. It has become. Therefore, the power of the battery 13 can be taken out from the sealed terminals 16 and 17.
[0018]
The battery 14 is a rechargeable secondary battery (storage battery), specifically a nickel metal hydride battery. In this nickel metal hydride battery, when the battery temperature becomes high (for example, 45 ° C. or higher), the hydrogen gas generated inside the battery cannot be absorbed inside the battery, and the internal pressure increases. Therefore, a relief valve 18 that opens when the battery internal pressure rises to a predetermined value is provided at the top of the battery 13. The relief valve 18 is configured such that when the battery internal pressure rises to a predetermined value, the valve body (not shown) is displaced against the spring force of the spring means (not shown) to open the inside of the battery 13 to the outside. It is.
[0019]
Incidentally, an opening 19 is opened at the center of the upper lid 12, and the gas side communication pipe 20 is connected to the opening 19 so as to rise upward. An adsorption member 21 described later is disposed in the middle of the gas side communication pipe 20. The gas side communication pipe 20 is connected to one end side of the radiator 22, and the other end side of the radiator 22 is opened near the bottom of the case body 11 of the sealed case 10 via the liquid side communication pipe 23. 24.
[0020]
Therefore, the inside of the sealed case 10 and the radiator 22 constitute a refrigerant system path composed of one closed circuit communicated via the gas side communication pipe 20 and the liquid side communication pipe 23. Is filled with a refrigerant as a working fluid of the thermosyphon cooling device and enclosed. As this refrigerant, a nonflammable low boiling point refrigerant such as florinate is used. In the inside of the sealed case 10, A indicates the liquid level of the refrigerant. In order to improve the circulation of the refrigerant between the sealed case 10 and the radiator 22, the radiator 22 is located above the refrigerant liquid level A. It is arranged on the upper side.
[0021]
Both the communication pipes 20 and 23 can be formed of a metal such as aluminum or a resin, and the radiator 22 has a tube 22a made of a metal such as aluminum having excellent heat conductivity and corrosion resistance. A plate-like fin member 22b is provided for promoting the transfer of heat between the refrigerant inside the tube 22a and the cooling air. The fin member 22b is also made of a metal such as aluminum.
[0022]
The radiator 22 of the present example is configured as an air cooling system that performs heat exchange with air (outside air) blown by the blower 25. The blower 25 includes a drive motor 25a and a blower fan 25b that is rotationally driven by the motor 25a.
The adsorbing member 21 includes an adsorbent 21a that selectively adsorbs hydrogen gas generated from the battery 13 in a case 21b. Here, the adsorbent 21a is made of, for example, granular zeolite.
[0023]
Next, the operation of the above configuration will be described. When the temperature of the battery 13 rises due to a chemical reaction of the battery 13 or Joule loss at the time of discharging, the liquid refrigerant filled in the internal space of the sealed case 10 is quickly discharged from the battery 13. It absorbs heat to boil and gasifies.
Therefore, the battery 13 can be cooled by taking the latent heat of vaporization of the refrigerant from the battery 13. Moreover, since the refrigerant is in direct contact with almost the entire surface of the battery 13 in the internal space of the sealed case 10, the cooling effect is great. Then, the refrigerant gasified in the internal space of the sealed case 10 moves up the gas side communication pipe 20 by natural convection due to a decrease in density, passes through the case 21 b of the adsorption member 21, and flows into the radiator 22. In the radiator 22, the gas refrigerant is cooled and condensed by exchanging heat with the air (outside air) blown by the blower 25. The condensed liquid refrigerant descends the liquid side communication pipe 23 by its own weight due to the increase in density and returns to the internal space of the sealed case 10 to be used for cooling the battery 13 again.
[0024]
By the way, in the battery 13, in the case of overcharge or the like, the generated gas (hydrogen gas) inside the battery cannot be absorbed and the internal pressure of the battery rises. Therefore, the relief valve 18 is opened and the hydrogen is discharged to the outside of the battery 13. Gas may leak out.
However, according to the present embodiment, the adsorption member 21 is disposed in the middle of the gas side communication pipe 20, and the adsorbent 21a provided in the adsorption member 21 has a molecular sieving function like zeolite. A molecule such as fluorinate having a large molecular diameter does not adsorb, and a molecule having a small molecular diameter such as hydrogen gas can be selectively captured. As a result, it is possible to prevent hydrogen gas from accumulating in the refrigerant system path, so that even if the inside of the sealed case 10 is opened at the time of maintenance and inspection due to electrode deterioration of the battery 13, a large amount of hydrogen gas or the like is generated at once. It is not released into the atmosphere.
[0025]
In addition, hydrogen gas has a very low boiling point compared to Fluorinert, which is a refrigerant of a thermosyphon type cooling device, and hydrogen gas acts as a non-condensable gas in the refrigerant system path of the thermosyphon type cooling device. When the hydrogen gas is released into the refrigerant gas 10 and the amount of the hydrogen gas in the refrigerant system increases, the cooling effect of the battery is reduced. However, according to the present embodiment, the adsorbing member 21 absorbs the hydrogen gas. Such problems can be avoided, and the cooling effect of the battery can be maintained well over a long period of time.
[0026]
On the other hand, by using a low boiling point refrigerant such as florinate as the refrigerant of the thermosyphon cooling device, the internal pressure (working fluid pressure) of the sealed case 10 is lowered, and the low strength design of the sealed case 10 is realized. The cost of the sealed case 10 can be reduced. Specifically, the working pressure of florinate is 35 to 70 kPa (about 1/2 of atmospheric pressure), and the boiling point is about 56 ° C.
[0027]
In addition, since low boiling point refrigerants such as florinate are nonflammable, the risk of ignition against leakage of gas generated in the battery 13 can be avoided, and safety can be improved.
(Second Embodiment)
FIG. 2 shows a second embodiment, in which a permeation member 26 that selectively permeates hydrogen gas generated from the battery 13 is installed instead of the adsorption member 21 in the first embodiment.
[0028]
That is, the permeation member 26 uses palladium that is excellent in hydrogen permeability, and a case 26 a communicating with the inside of the pipe 20 is installed on the upper side of the gas side communication pipe 20. A tubular body 26b is disposed so as to penetrate the inside. The tubular body 26b is made of palladium, and both ends thereof are open to the atmosphere outside the case 26a.
[0029]
According to the second embodiment, the hydrogen gas mixed in the refrigerant path flows into the case 26a located at the uppermost part of the refrigerant path. Since palladium constituting the tubular body 26b is excellent in hydrogen permeability, it does not permeate the refrigerant, such as fluorinate, but selectively permeates only hydrogen gas. Can be discharged.
[0030]
(Third embodiment)
FIG. 3 shows a third embodiment, which implements the second embodiment more effectively. Paying attention to the fact that palladium has the property of improving hydrogen permeability when heated to a high temperature, an electric heater 26c as a heating means is additionally installed in the permeable member 26.
[0031]
According to the third embodiment, the permeation amount of hydrogen gas can be increased by energizing the electric heater 26c and heating the tubular body 26b made of palladium to a high temperature. Therefore, even when the amount of generated hydrogen gas is large as in the severe usage environment of the battery 13, the amount of hydrogen gas permeating through the tubular body 26b made of palladium is increased, and hydrogen remains in the refrigerant system path. Can be prevented.
[0032]
In addition, you may use the hot water pipe etc. which warm water circulates as a heating means instead of the electric heater 26c.
(Fourth embodiment)
FIG. 4 shows a fourth embodiment. In the first to third embodiments described above, the method of cooling the battery 13 with the thermosyphon cooling device has been described. However, the fourth embodiment is a refrigeration cycle for vehicle air conditioning. The battery 13 is configured to be cooled by the cold heat of the low-pressure side refrigerant.
[0033]
In FIG. 4, the compressor 30 compresses and discharges the refrigerant (for example, HFC-134a) of the refrigeration cycle, and the high-temperature and high-pressure superheated gas refrigerant discharged from the compressor 30 is cooled by the condenser 31 and condensed. To do. The condensed refrigerant is gas-liquid separated by the liquid receiver 32, and the liquid refrigerant is depressurized by the temperature type expansion valve (decompression unit) 33 to a low-temperature low-pressure gas-liquid two-phase refrigerant. Then, this gas-liquid two-phase refrigerant absorbs heat from the conditioned air blown by an air conditioner blower (not shown) in the evaporator 34, evaporates and gasifies, and the gas refrigerant is sucked into the compressor 30 and again. , Compressed.
[0034]
For such a vehicle air conditioning refrigeration cycle, in the battery cooling device of the fourth embodiment, the battery 13 is housed in a refrigerant passage between the downstream side of the temperature type expansion valve 33 and the upstream side of the evaporator 34. Case 10 is installed. Of the gas-liquid two-phase refrigerant decompressed by the temperature type expansion valve 33, a liquid refrigerant region B in which liquid refrigerant accumulates is formed on the lower side inside the sealed case 10, and the gas inside the sealed case 10 has an air The gas refrigerant of the liquid two-phase refrigerant gathers to form a gas region C.
[0035]
The lower side of the battery 13 is arranged so as to be immersed in the liquid refrigerant region B inside the sealed case 10. In the example shown in FIG. 4, the adsorbing member 21 that adsorbs hydrogen gas is disposed on the inner surface of the upper lid 12 of the sealed case 10, and the adsorbing member 21 is positioned in the gas region C inside the sealed case 10. .
According to the fourth embodiment, the low-temperature and low-pressure gas-liquid two-phase refrigerant decompressed by the temperature type expansion valve 33 in the vehicle air-conditioning refrigeration cycle flows into the sealed case 10, where a part of the low-pressure side liquid refrigerant Absorbs heat from the battery 13 and evaporates. Therefore, the battery 13 can be cooled by the latent heat of vaporization of the refrigerant. Here, as the cooling medium for cooling the battery 13, a low-temperature refrigerant of the air-conditioning refrigeration cycle is used, so a very large temperature difference can be set between the battery 13 and the low-temperature refrigerant, and the cooling capacity of the battery 13 can be increased. It can be improved dramatically.
[0036]
When the vehicle air conditioning refrigeration cycle is configured as a heat pump, during the winter heating, the refrigerant on the refrigeration cycle side absorbs heat inside the sealed case 10 to recover waste heat, thereby heating in the winter. Ability can be increased. Of the refrigerant that has passed through the sealed case 10, the remaining liquid refrigerant evaporates in the air conditioning evaporator 34 to cool the conditioned air.
[0037]
On the other hand, the hydrogen gas generated from the battery 13 in the sealed case 10 is selectively adsorbed by the adsorbing member 21 installed in the gas region C above the sealed case 10.
In addition, in 4th Embodiment, although the adsorption member 21 is installed in the gas area C above the inside of the airtight case 10, if the adsorption member 21 is a gas area, it can exhibit the adsorption action of hydrogen gas anywhere, and adsorption The member 21 can be installed in a gas region outside the sealed case 10, that is, in the suction side portion D of the compressor 30, the discharge side portion E of the compressor 30, the gas region F inside the liquid receiver 32, and the like. In short, the adsorbing member 21 may be installed anywhere within the refrigeration cycle.
[0038]
In each of the above embodiments, zeolite is used as the adsorbent 21a of the adsorbing member 21, but in addition to zeolite, any adsorbent can be used as long as it can adsorb a large amount of hydrogen gas, such as a hydrogen storage alloy. 21a can be used.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an entire system showing a first embodiment of the present invention.
FIG. 2 is a configuration diagram of an entire system showing a second embodiment of the present invention.
FIG. 3 is a main part configuration diagram showing a third embodiment of the present invention;
FIG. 4 is a refrigeration cycle diagram showing a fourth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Sealed case, 13 ... Battery, 21 ... Adsorption member, 22 ... Radiator,
26 ... Permeation member, 33 ... Temperature type expansion valve, 34 ... Evaporator.

Claims

A sealed case (10) for housing a nickel metal hydride battery (13) ;
A radiator (22, 31) communicating with the inside of the sealed case (10),
A refrigerant is filled in a refrigerant system path including a closed circuit including the sealed case (10) and the radiator (22, 31) ,
The refrigerant absorbs heat from the battery (13) and evaporates inside the sealed case (10) to cool the battery (13), and the evaporated gas refrigerant is transferred to the radiator (22, 31). Heat is condensed by condensation, and the condensed liquid refrigerant flows into the sealed case .
Further, characterized in that the suction member (21) which selectively adsorb hydrogen gas generated from the battery (13), through which gas refrigerant of the refrigerant pathways, or, with the gas zone in which the gas refrigerant is collected Battery cooling device.

A sealed case (10) for housing a nickel metal hydride battery (13);
A radiator (22) communicating with the inside of the sealed case (10) ;
A gas-side communication pipe (20) that communicates the sealed case (10) and the radiator (22) to form a flow path of a gas refrigerant;
A liquid side communication pipe (23) that communicates the sealed case (10) and the radiator (22) to form a liquid refrigerant flow path ;
Refrigerant is filled in a refrigerant system path including the sealed case (10) , the radiator (22) , the gas side communication pipe (20), and the liquid side communication pipe (23) ,
The radiator (22) is disposed above the liquid refrigerant inside the sealed case (10),
Inside the sealed case (10), heat is absorbed from the battery (13) and the refrigerant evaporates, and the evaporated gas refrigerant rises up the gas side communication pipe (20) by natural convection and the radiator ( 22), the gas refrigerant is cooled and condensed by the radiator (22), and the condensed liquid refrigerant descends the liquid side communication pipe (23) by its own weight, and the inside of the sealed case (10). It is designed to recirculate around the battery (13),
Furthermore, the battery cooling device further comprising an adsorption member (21) for selectively adsorbing hydrogen gas generated from the battery (13) in the gas side communication pipe (20) .

The inside of the sealed case (10) containing the nickel-metal hydride battery (13) is connected to a passage through which the low-pressure side refrigerant of the refrigeration cycle flows, so that the low-pressure side refrigerant absorbs heat from the battery (13) and evaporates. West,
Further, the battery (13) is generated in any of the refrigeration cycle including the gas region where the gas refrigerant in the sealed case (10) collects , or in the gas region where the gas refrigerant collects. A battery cooling device comprising an adsorption member (21) that selectively adsorbs hydrogen gas.

The battery cooling device according to any one of claims 1 to 3, wherein the adsorbing member (21) includes an adsorbent (21a) made of zeolite or a hydrogen storage alloy.

The battery cooling device according to claim 2, wherein the radiator (22) is an air-cooled heat exchanger that exchanges heat with air to cool and condense the gas refrigerant.

A sealed case (10) for housing a nickel metal hydride battery (13) ;
A radiator (22, 31) communicating with the inside of the sealed case (10),
A refrigerant is filled in a refrigerant system path including a closed circuit including the sealed case (10) and the radiator (22, 31) ,
The refrigerant absorbs heat from the battery (13) and evaporates inside the sealed case (10) to cool the battery (13), and the evaporated gas refrigerant is transferred to the radiator (22, 31). Heat is condensed by condensation, and the condensed liquid refrigerant flows into the sealed case .
Furthermore, the battery (13) transmitting member selectively permeable to hydrogen gas generated from the (26), flows the gas refrigerant of the refrigerant system path or, provided the gas tract where the gas refrigerant is collected, the hydrogen gas A battery cooling device for discharging to the outside of the refrigerant system path through the permeable member (26).

The battery cooling device according to claim 6, further comprising heating means (26c) for heating the transmission member (26).

The battery cooling device according to claim 6 or 7, wherein the transmission member (26) has a tubular body (26b) made of palladium.