JP2005339872A - Fuel cell system - Google Patents

Fuel cell system Download PDF

Info

Publication number
JP2005339872A
JP2005339872A JP2004154492A JP2004154492A JP2005339872A JP 2005339872 A JP2005339872 A JP 2005339872A JP 2004154492 A JP2004154492 A JP 2004154492A JP 2004154492 A JP2004154492 A JP 2004154492A JP 2005339872 A JP2005339872 A JP 2005339872A
Authority
JP
Japan
Prior art keywords
flow path
fuel cell
cooling medium
temperature
respect
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2004154492A
Other languages
Japanese (ja)
Inventor
Yasushi Takahashi
靖 高橋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Motor Corp
Original Assignee
Toyota Motor Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toyota Motor Corp filed Critical Toyota Motor Corp
Priority to JP2004154492A priority Critical patent/JP2005339872A/en
Publication of JP2005339872A publication Critical patent/JP2005339872A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system capable of improving drainage of an electrode on the lower side with respect to the gravity direction, and of restraining the electrode and an electrolyte membrane from drying on the upper side with respect to the gravity direction. <P>SOLUTION: This fuel cell system is provided with: a reaction gas passage for running a reaction gas; and a cooling medium passage for running a cooling medium. The fuel cell system is characterized by that the cooling medium passage is grouped into two or more passage regions having different positions with respect to the gravity direction of the fuel cell; and the temperature of the cooling medium flowing through the cooling medium passage is increased toward the lower side with respect to the gravity direction of the fuel cell. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、燃料電池を冷却する冷却媒体が通流する冷却媒体流路を備える燃料電池システムに関する。   The present invention relates to a fuel cell system including a cooling medium flow path through which a cooling medium for cooling a fuel cell flows.

燃料電池は、電解質膜を燃料極及び酸化剤極で挟持した基本構造を有する単セルを複数積層して構成される。各単セルには、燃料極に水素を供給する燃料ガス流路、酸化剤極に酸素を供給する酸化剤ガス流路が備えられており、各電極に反応ガス（燃料ガス又は酸化剤ガス）が供給されることによって電気化学反応が起こり発電する。さらに、上記反応ガス流路の外側には冷却媒体流路が設けられており、この流路に冷却媒体を通流させることにより、電気化学反応に伴う温度上昇を抑制し、燃料電池の温度を作動温度範囲内に維持している。
従来、燃料電池を冷却する様々な方法が提案されており、例えば、特許文献１や特許文献２に記載の方法等がある。 A fuel cell is configured by stacking a plurality of single cells having a basic structure in which an electrolyte membrane is sandwiched between a fuel electrode and an oxidant electrode. Each single cell is provided with a fuel gas flow path for supplying hydrogen to the fuel electrode and an oxidant gas flow path for supplying oxygen to the oxidizer electrode, and each electrode has a reaction gas (fuel gas or oxidant gas). As a result, an electrochemical reaction occurs and power is generated. Further, a cooling medium flow path is provided outside the reaction gas flow path, and by passing the cooling medium through this flow path, the temperature rise due to the electrochemical reaction is suppressed, and the temperature of the fuel cell is increased. Maintained within operating temperature range.
Conventionally, various methods for cooling a fuel cell have been proposed. For example, there are methods described in Patent Document 1 and Patent Document 2.

上記電気化学反応の結果生成される水や、反応ガスと共に燃料電池に供給された水分の残留分は、未反応の反応ガスと共に反応ガス流路を通って排出される。これらの生成水等の水分が液体状態で存在する場合、水分の排出性が悪く、さらには反応ガス流路を塞いでしまうことがある。従って、水分の排出性の点からは、未反応の反応ガス中に気体の状態で水分を含ませることが好ましく、そのためには燃料電池の内部温度を高くする必要がある。特に、固体高分子型燃料電池では、水分が過剰に存在することによって、電極が目詰まりを起こして電池電圧が低下する、いわゆるフラッディングが発生してしまう。その結果、電極へのガスの供給、拡散が不十分となり、電気化学反応の進行が大きく妨げられることになる。このフラッディングは、燃料電池の反応ガス流路の通流方向に関する下流側で発生しやすく、さらに電気化学反応により水が生成する酸化剤極側の電極において特に発生しやすい。   The water generated as a result of the electrochemical reaction and the residual moisture supplied to the fuel cell together with the reaction gas are discharged through the reaction gas channel together with the unreacted reaction gas. When the water such as the generated water exists in a liquid state, the water is not easily discharged, and the reaction gas flow path may be blocked. Therefore, from the viewpoint of water dischargeability, it is preferable that moisture is contained in a gas state in the unreacted reaction gas. For this purpose, the internal temperature of the fuel cell needs to be increased. In particular, in a polymer electrolyte fuel cell, when water is present excessively, so-called flooding occurs in which the electrode is clogged and the battery voltage is lowered. As a result, the supply and diffusion of gas to the electrode are insufficient, and the progress of the electrochemical reaction is greatly hindered. This flooding is likely to occur on the downstream side in the flow direction of the reaction gas flow path of the fuel cell, and more particularly to the oxidant electrode side electrode where water is generated by an electrochemical reaction.

また、高い電池特性を有する固体高分子型燃料電池とするためには、電極の触媒層及び電解質膜が適度な湿度状態を保つことが重要であり、反応ガスを加湿して供給することも行われている。しかしながら、反応ガスを加湿して供給しても反応ガス流路の上流側の位置では電極及び電解質膜が乾燥しやすく、このような電極及び電解質膜の乾燥を防ぐ点からは、加湿された反応ガス中の水蒸気等の電池内に存在する水蒸気が凝集し液体となって電極及び電解質膜を湿潤することが好ましい。そのためには燃料電池の内部温度を低くする必要がある。
特に、自動車用の燃料電池は、運転温度が燃料電池の使用環境や使用状態によって変化するため、外気温程度から１００℃程度まで燃料電池の内部温度は変化する。また、自動車用のように大面積の燃料電池では、同一の単セル内での環境が大きく異なるため、上述したような部分的な乾燥やフラッディングが発生しやすくなる。 In order to obtain a polymer electrolyte fuel cell having high battery characteristics, it is important that the electrode catalyst layer and the electrolyte membrane maintain an appropriate humidity state, and the reaction gas is also supplied with humidification. It has been broken. However, even if the reaction gas is humidified and supplied, the electrode and the electrolyte membrane are easily dried at a position upstream of the reaction gas flow path. From the viewpoint of preventing the electrode and the electrolyte membrane from being dried, a humidified reaction is performed. It is preferable that water vapor existing in the battery, such as water vapor in the gas, aggregates into a liquid and wets the electrode and the electrolyte membrane. For this purpose, it is necessary to lower the internal temperature of the fuel cell.
In particular, since the operating temperature of a fuel cell for an automobile changes depending on the usage environment and usage state of the fuel cell, the internal temperature of the fuel cell changes from about the outside air temperature to about 100 ° C. In addition, in a fuel cell having a large area as in an automobile, the environment in the same single cell is greatly different, so that partial drying and flooding as described above are likely to occur.

以上のような燃料電池における排水性や乾燥を改善するため、燃料電池の冷却システムにより燃料電池面内の温度分布を制御する方法が提案されており、例えば、特許文献３、特許文献４及び特許文献５に記載の方法が挙げられる。具体的には、特許文献３には、反応ガス流路に流入する酸化剤ガス及び燃料ガスの少なくとも一方のガスの通流方向が、単セルの面内温度分布の低い部分側から反応ガス流路に流入し、面内温度分布の高い部分側から排出されるよう形成されてなることを特徴とする固体高分子型燃料電池の反応ガス・冷却媒体通流構造が記載されている。また、特許文献５には、燃料電池の運転状態によって、加熱流体、冷却流体の通流方向を切り替えることで常に単セル面内の温度分布を反応ガス上流側より下流側の方が高くなるようにする固体高分子型燃料電池の運転方法が記載されている。   In order to improve drainage and drying in the fuel cell as described above, methods for controlling the temperature distribution in the fuel cell surface by a fuel cell cooling system have been proposed. For example, Patent Document 3, Patent Document 4 and Patent Examples thereof include the method described in Document 5. Specifically, Patent Document 3 discloses that the flow direction of at least one of the oxidant gas and the fuel gas flowing into the reaction gas flow path is from the side where the in-plane temperature distribution of the single cell is low. A reaction gas / cooling medium flow structure for a polymer electrolyte fuel cell is described, which is formed so as to flow into a passage and to be discharged from a portion having a high in-plane temperature distribution. Further, in Patent Document 5, the temperature distribution in the single cell plane is always higher on the downstream side than on the upstream side of the reaction gas by switching the flow direction of the heating fluid and the cooling fluid depending on the operating state of the fuel cell. A method of operating a polymer electrolyte fuel cell is described.

特開平６−１２４７１６号公報JP-A-6-124716 特開２０００−１８２６３６号公報JP 2000-182636 A 特開平５−１４４４５１号公報JP-A-5-144451 特開２００３−１７１０５号公報JP 2003-17105 A 特開平８−７８０３３号公報JP-A-8-78033

上記したような燃料電池面内に温度分布を形成させる従来の冷却方法は、主に反応ガス流路の上流側で発生する乾燥や下流側で発生するフラッディングを軽減しようとするものである。しかしながら、電解質膜として固体高分子電解質膜を用いた燃料電池（固体高分子型燃料電池）等は、排水性を高めるために単セルを垂直に立て、水平方向に積層して電池積層体を構成するのが一般的であり、このような構造を有する燃料電池においては、燃料電池の重力方向に関する下部側（以下、重力方向下部ということがある）へ生成水等の水分が自重により移動することによって、重力方向下部では部分的に水分過剰な状態となったり、重力方向上部が乾燥しやすくなることがある。   The conventional cooling method for forming a temperature distribution in the surface of the fuel cell as described above is intended to reduce the drying that occurs mainly on the upstream side of the reaction gas flow path and the flooding that occurs on the downstream side. However, fuel cells using solid polymer electrolyte membranes as electrolyte membranes (solid polymer fuel cells), etc., are constructed by stacking the cells vertically and stacking them horizontally to improve drainage. In a fuel cell having such a structure, moisture such as generated water moves by its own weight to the lower side of the fuel cell in the gravitational direction (hereinafter sometimes referred to as the lower part in the gravitational direction). Therefore, the lower part in the gravitational direction may be partially excessive in moisture, or the upper part in the gravitational direction may be easily dried.

また、一つの冷却系統で燃料電池面内に温度分布を形成させる方法では、冷却媒体の入口温度と出口温度の差を大きくするためには冷却媒体の流速を小さくするしかなく、このような方法では、反応ガス流路の上流側での膜の乾燥や、反応ガス流路の下流側でのフラッティングが最も問題となる高負荷運転時には冷却能力が不足していまい、十分に対応できない場合がある。これを見越して過剰な冷却システムを付随させることも可能ではあるが、価格、スペースの面で無駄が多く、特に搭載スペースに制限がある自動車の場合には現実的ではない。   Further, in the method of forming the temperature distribution in the fuel cell plane with one cooling system, the only way to increase the difference between the inlet temperature and the outlet temperature of the cooling medium is to reduce the flow rate of the cooling medium. In the case of high-load operation where drying of the membrane upstream of the reaction gas flow path or flatting downstream of the reaction gas flow path is the most problematic, the cooling capacity may be insufficient and may not be adequate. is there. It is possible to attach an excessive cooling system in anticipation of this, but it is wasteful in terms of price and space, and it is not realistic especially in the case of a car with limited mounting space.

本発明は、上記問題を考慮して成し遂げられたものであり、燃料電池の重力方向に関する下部側での電極の排水性を向上させ、同時に重力方向に関する上部側での電極及び電解質膜の乾燥を抑制することができる燃料電池システムを提供することを目的とする。   The present invention has been accomplished in consideration of the above problems, and improves drainage of the electrode on the lower side with respect to the gravity direction of the fuel cell, and at the same time, drying of the electrode and the electrolyte membrane on the upper side with respect to the direction of gravity. It aims at providing the fuel cell system which can be suppressed.

本発明により提供される燃料電池システムは、反応ガスが通流する反応ガス流路及び冷却媒体が通流する冷却媒体流路を備える燃料電池システムであって、前記冷却媒体流路を、燃料電池の重力方向に関して位置が異なる２つ以上の流路領域に群分けし、当該冷却媒体流路を通流する冷却媒体の温度が、前記燃料電池の重力方向に関して下部側の流路領域ほど高いことを特徴とする。   A fuel cell system provided by the present invention is a fuel cell system including a reaction gas flow path through which a reaction gas flows and a cooling medium flow path through which a cooling medium flows, and the cooling medium flow path is connected to the fuel cell. Grouped into two or more flow path regions having different positions with respect to the gravity direction, and the temperature of the coolant flowing through the coolant flow path is higher in the lower flow path region with respect to the gravity direction of the fuel cell. It is characterized by.

本発明の燃料電池システムによれば、燃料電池の重力方向に関して下部側の流路領域ほど高温の冷却媒体を通流させることによって、燃料電池の重力方向に関する下部（以下、重力方向下部ということがある）の内部温度を高めに設定することができる。燃料電池の重力方向下部は、自重により水分が移動してくるため過剰な水分が存在するが、本発明によれば、重力方向下部に存在する過剰な水分が高めの温度設定によって蒸発しやすくなり、水蒸気として存在する水分量を増加させることができるため、未反応の反応ガス（以下、未反応ガスということがある）と共に過剰な水分が単セルの外に排出されやすくなる。   According to the fuel cell system of the present invention, by passing a coolant having a higher temperature in the flow path region on the lower side in the gravity direction of the fuel cell, the lower portion in the gravity direction of the fuel cell (hereinafter referred to as the lower portion in the gravity direction). The internal temperature can be set higher. In the lower part of the fuel cell in the gravitational direction, excess moisture exists because the moisture moves due to its own weight. However, according to the present invention, excess moisture present in the lower part of the gravity direction tends to evaporate due to a higher temperature setting. Since the amount of water present as water vapor can be increased, excess water is easily discharged out of the single cell together with unreacted reaction gas (hereinafter also referred to as unreacted gas).

一方、燃料電池の重力方向に関して上部側の流路領域ほど低温の冷却媒体を通流させることによって、燃料電池の重力方向に関する上部（以下、重力方向上部ということがある）は内部温度が低めに設定されるため、水分が凝縮しやすくなり液体状態で存在する水分量を増加させることができる。従って、重力方向上部の電極や電解質膜を適度な湿潤状態とし、乾燥するのを防ぐことができる。
すなわち、本発明の燃料電池システムによれば、電極及び電解質膜の重力方向における水分分布を制御し、部分的な乾燥やフラッディングの発生を抑制することが可能である。 On the other hand, by passing a low-temperature cooling medium in the upper flow path region with respect to the gravity direction of the fuel cell, the upper part of the fuel cell in the gravity direction (hereinafter sometimes referred to as the upper part in the gravity direction) has a lower internal temperature. Since it is set, it becomes easy to condense moisture, and the amount of moisture present in the liquid state can be increased. Therefore, it is possible to prevent the electrode and the electrolyte membrane in the upper part of the gravity direction from being properly wetted and dried.
That is, according to the fuel cell system of the present invention, it is possible to control the moisture distribution in the gravity direction of the electrode and the electrolyte membrane, and to suppress partial drying and flooding.

上記のように、冷却媒体流路を通流する冷却媒体の温度を流路領域ごとに効率良く制御し、また、燃料電池の広い運転温度範囲に対応するためには、前記冷却媒体流路を前記燃料電池の重力方向に関して群分けした前記の各流路領域に互いに独立した冷却系統を設け、前記燃料電池の重力方向に関して上部側の冷却系統よりも温度が高い冷却媒体を下部側の冷却系統に通流することが好ましい。   As described above, in order to efficiently control the temperature of the cooling medium flowing through the cooling medium flow path for each flow path area, and to cope with the wide operating temperature range of the fuel cell, the cooling medium flow path is A cooling system that is independent of each other is provided in each of the flow path regions that are grouped in the gravity direction of the fuel cell, and a cooling medium having a temperature higher than that of the upper cooling system in the gravity direction of the fuel cell is provided in the lower cooling system. It is preferable to flow through.

さらに、前記冷却媒体流路を前記燃料電池の重力方向に関して２つ以上の流路領域に群分けすると共に、さらに、生成水を発生する電極側の反応ガス流路の通流方向に関して位置が異なる２つ以上の流路領域に群分けし、前記重力方向に関して群分けされた少なくとも１つの流路領域において、当該冷却媒体流路を通流する冷却媒体の温度が、前記反応ガス流路の通流方向に関して下流側の流路領域ほど高くすることが好ましい。このように、重力方向の下部側ほど高温である温度分布を電池面内に形成した上で、さらに反応ガス流路の通流方向に関して下流側（以下、反応ガス流路下流側ということがある）ほど高温の冷却媒体を通流させることによって、電極及び電解質膜の重力方向における上部又は下部で発生する部分的な乾燥やフラッディングを抑制すると同時に、反応ガス流路の通流方向における水分分布を制御し、部分的な乾燥やフラッディングの発生を抑制することが可能である。   Further, the cooling medium flow path is grouped into two or more flow path regions with respect to the gravitational direction of the fuel cell, and further, the position is different with respect to the flow direction of the reaction gas flow path on the electrode side that generates the generated water. The temperature of the cooling medium flowing through the cooling medium flow path in at least one flow path area divided into two or more flow path areas and grouped with respect to the direction of gravitational force passes through the reaction gas flow path. It is preferable that the flow path region on the downstream side is higher in the flow direction. In this way, a temperature distribution that is higher at the lower side in the gravitational direction is formed in the battery surface, and further on the downstream side in the flow direction of the reactive gas channel (hereinafter, referred to as the downstream side of the reactive gas channel). ) By passing the cooling medium at a higher temperature, it is possible to suppress partial drying or flooding that occurs at the top or bottom of the electrode and electrolyte membrane in the direction of gravity, and at the same time, to reduce the moisture distribution in the direction of flow of the reaction gas channel. It is possible to control and suppress the occurrence of partial drying and flooding.

このような、反応ガス流路の通流方向に関して群分けされた流路領域を通流する冷却媒体の温度を流路領域ごとに効率良く制御するためには、前記冷却媒体流路を前記燃料電池の重力方向に関して群分けした少なくとも１つの流路領域において、当該冷却媒体流路を通流する冷却媒体の温度が、前記生成水を発生する電極側の反応ガス流路の通流方向に関して下流側ほど高くなるように、前記反応ガス流路の通流方向に関して上流側に前記冷却媒体流路の入口部を設け、前記反応ガス流路の通流方向に関して下流側に前記冷却媒体流路の出口部を設けることが好ましい。前記冷却媒体流路を前記燃料電池の重力方向に関して群分けした前記の各流路領域に互いに独立した冷却系統を設けた場合には、当該冷却系統の少なくとも１つにおいて、当該冷却媒体流路を通流する冷却媒体の温度が、前記生成水を発生する電極側の反応ガス流路の通流方向に関して下流側ほど高くなるように、流路入口部を前記反応ガス流路の通流方向に関して上流側に設け、流路出口部を前記反応ガス流路の下流側に設けることが好ましい。   In order to efficiently control the temperature of the cooling medium flowing through the flow path regions grouped in the flow direction of the reaction gas flow path for each flow path area, the cooling medium flow path is set to the fuel. In at least one flow path region grouped with respect to the gravity direction of the battery, the temperature of the cooling medium flowing through the cooling medium flow path is downstream with respect to the flow direction of the reaction gas flow path on the electrode side that generates the generated water. An inlet portion of the cooling medium flow path is provided on the upstream side with respect to the flow direction of the reaction gas flow path, and the cooling medium flow path is disposed on the downstream side with respect to the flow direction of the reaction gas flow path so as to increase toward the side. It is preferable to provide an outlet. In the case where an independent cooling system is provided in each of the flow path regions obtained by grouping the cooling medium flow paths with respect to the gravitational direction of the fuel cell, the cooling medium flow path is provided in at least one of the cooling systems. The flow path inlet portion is set with respect to the flow direction of the reaction gas flow path so that the temperature of the cooling medium flowing therethrough becomes higher toward the downstream side with respect to the flow direction of the reaction gas flow path on the electrode side that generates the generated water. Preferably, it is provided on the upstream side, and the channel outlet is provided on the downstream side of the reaction gas channel.

特に、前記燃料電池の重力方向に関して最も上部側に位置する流路領域の冷却媒体流路の入口部における冷却媒体温度と、前記燃料電池の重力方向に対して最も下部側に位置する流路領域の冷却媒体流路の入口部における冷却媒体温度との差が１０〜２０℃であり、前記燃料電池の重力方向に対して最も上部側に位置する流路領域の冷却媒体流路の出口部における冷却媒体温度と、前記燃料電池の重力方向に対して最も下部側に位置する流路領域の冷却媒体流路の出口部における冷却媒体温度との差が１０〜２０℃であるように各流路領域の冷却媒体流路を通流する冷却媒体の温度を制御した場合、上記のような過剰な水分の排出性能及び乾燥の防止効果が高くなるため好ましい。同様の観点から、前記冷却媒体流路を前記燃料電池の重力方向に関して群分けした前記の各流路領域に互いに独立した冷却系統を設けた場合には、前記冷却媒体流路を前記燃料電池の重力方向に関して群分けした前記の各流路領域に互いに独立した冷却系統を設け、前記燃料電池の重力方向に関して最も上部側に位置する流路領域に設けられた冷却系統の流路入口部における冷却媒体温度と、前記燃料電池の重力方向に対して最も下部側に位置する流路領域に設けられた冷却系統の流路の入口部における冷却媒体温度との差が１０〜２０℃であり、前記燃料電池の重力方向に対して最も上部側に位置する流路領域に設けられた冷却系統の流路出口部における冷却媒体温度と、前記燃料電池の重力方向に対して最も下部側に位置する流路領域に設けられた冷却系統の流路出口部における冷却媒体温度との差が１０〜２０℃であるように各冷却系統の冷却媒体流路を通流する冷却媒体の温度を制御することが好ましい。   In particular, the cooling medium temperature at the inlet of the cooling medium flow path of the flow path area located on the uppermost side with respect to the gravity direction of the fuel cell, and the flow path area located on the lowermost side with respect to the gravity direction of the fuel cell The difference between the cooling medium temperature at the inlet of the cooling medium flow path is 10 to 20 ° C., and the cooling medium flow path is located at the uppermost side with respect to the gravity direction of the fuel cell. Each flow path is such that the difference between the cooling medium temperature and the cooling medium temperature at the outlet of the cooling medium flow path in the flow path area located on the lowermost side with respect to the gravitational direction of the fuel cell is 10 to 20 ° C. Controlling the temperature of the cooling medium flowing through the cooling medium flow path in the region is preferable because the above-described excessive water drainage performance and drying prevention effect are enhanced. From the same point of view, in the case where an independent cooling system is provided in each of the flow path regions in which the cooling medium flow paths are grouped with respect to the gravity direction of the fuel cell, the cooling medium flow paths are connected to the fuel cell. A cooling system that is independent of each other is provided in each of the flow path areas that are grouped with respect to the direction of gravity, and cooling is performed at the flow path inlet of the cooling system that is provided in the flow path area that is located on the uppermost side with respect to the gravity direction of the fuel cell. The difference between the medium temperature and the cooling medium temperature at the inlet portion of the flow path of the cooling system provided in the flow path region located on the lowest side with respect to the gravity direction of the fuel cell is 10 to 20 ° C., The cooling medium temperature at the outlet of the cooling system provided in the channel region located on the uppermost side with respect to the gravity direction of the fuel cell, and the flow located on the lowermost side with respect to the gravity direction of the fuel cell. In the road area It is preferable that the difference between the cooling medium temperature in the flow path outlet portion of the eclipse cooling system controls the temperature of the cooling medium flowing through the cooling medium flow path of the cooling system to be a 10 to 20 ° C..

さらに、反応ガス流路内に存在する過剰な水分の排出性を高めるためには、生成水を発生する電極側の反応ガス流路の下流側が、当該反応ガス流路の通流方向の上流側から下流側に向かって直線状に規制されていることが好ましい。このような形状のガス流路を設けることによって、反応ガスの反応ガス流路間への回り込みを防止し、凝縮した生成水等の過剰な液体状の水分をガス圧によって速やかに燃料電池外に押し出すことができるので、効率良く排水することができる。   Furthermore, in order to enhance the discharge of excess moisture present in the reaction gas channel, the downstream side of the reaction gas channel on the electrode side that generates the generated water is located upstream of the reaction gas channel in the flow direction. It is preferable that it is regulated linearly from the downstream toward the downstream side. By providing such a gas flow path, the reaction gas can be prevented from entering between the reaction gas flow paths, and excess liquid water such as condensed product water can be quickly removed from the fuel cell by the gas pressure. Since it can extrude, it can drain efficiently.

本発明の燃料電池システムによれば、燃料電池面内に重力方向の温度分布を形成することによって、固体高分子型燃料電池に代表されるような燃料電池が抱える燃料電池面内の水分分布の偏りを原因とする問題を解決することができる。すなわち、自重による水分の重力方向下部への移動を原因とする重力方向下部における過剰な水分の排出性を向上させ、フラッディングを抑制し、同時に、重力方向上部における電極及び電解質膜の乾燥を改善することが可能である。従って、発電有効面積が大きく、高い発電性能を発揮する燃料電池が得られる。   According to the fuel cell system of the present invention, by forming a temperature distribution in the direction of gravity in the surface of the fuel cell, the moisture distribution in the surface of the fuel cell held by the fuel cell represented by the polymer electrolyte fuel cell is reduced. Problems due to bias can be solved. That is, it improves the drainage of excess moisture in the lower gravity direction due to the movement of moisture in the lower gravity direction due to its own weight, suppresses flooding, and at the same time improves the drying of the electrode and electrolyte membrane in the upper gravity direction It is possible. Therefore, a fuel cell having a large power generation effective area and high power generation performance can be obtained.

特に、冷却系統を２つ以上設けた場合、各冷却系統を通流する冷却媒体の温度を調節することにより、燃料電池面内の温度分布を容易に、且つ細かく形成することができる。また、冷却媒体の流量を調節しなくても、燃料電池面内に温度分布を形成することができるため、高負荷運転時にも十分な温度管理能力を発揮する。しかも、冷却系統毎に冷却媒体の温度や流量等を調節することによって、燃料電池の運転条件に合わせて適した温度分布を形成することが可能である。   In particular, when two or more cooling systems are provided, the temperature distribution in the fuel cell surface can be easily and finely formed by adjusting the temperature of the cooling medium flowing through each cooling system. Further, since the temperature distribution can be formed in the fuel cell plane without adjusting the flow rate of the cooling medium, sufficient temperature management capability is exhibited even during high load operation. In addition, by adjusting the temperature and flow rate of the cooling medium for each cooling system, it is possible to form a temperature distribution suitable for the operating conditions of the fuel cell.

さらに、燃料電池面内に反応ガス流路の通流方向に関する温度分布を形成した場合には、電極及び電解質膜の重力方向における水分分布を改善すると同時に、反応ガス流路の上流側における乾燥、並びに、反応ガス流路の下流側におけるフラッディングも抑制することが可能である。   Furthermore, when the temperature distribution related to the flow direction of the reaction gas flow path is formed in the fuel cell surface, the moisture distribution in the gravity direction of the electrode and the electrolyte membrane is improved, and at the same time, drying on the upstream side of the reaction gas flow path, In addition, flooding on the downstream side of the reaction gas channel can also be suppressed.

また、反応ガス流路の通流方向の下流側において、反応ガス通流方向の上流側から下流側に向かって反応ガス流路を直線状に規制することによって、液体状態で存在する水分が燃料電池外に排出されやすいようにすることができる。   In addition, on the downstream side in the flow direction of the reaction gas flow path, the reaction gas flow path is linearly regulated from the upstream side to the downstream side in the reaction gas flow direction, so that the water existing in the liquid state is fueled. It can be made easy to be discharged out of the battery.

まず、図１及び図２を用いて、本発明の燃料電池システムを説明する。
なお、図１には本発明の燃料電池システムの一構成例、図２は固体高分子型燃料電池の概略を示す断面図である。
燃料電池９は、図２に示すように、固体高分子電解質膜１の一方の面に燃料極２、及び他方の面に酸化剤極３を接合し、さらにその外側を一対のセパレータ４、５で挟持した単セルを複数積層して構成されたスタックからなる。セパレータ４、５には燃料極２に水素を供給する燃料ガス流路６及び酸化剤極３に酸素を供給する酸化剤ガス流路７と、冷却媒体が通流する冷却媒体流路８とが形成されている。固体高分子型燃料電池は、通常、図２のように、単セルを垂直方向に立てた状態で水平方向に積層されるが、本発明において燃料電池の積層方向は、単セルを垂直方向に立てた状態で水平方向に積層する方向に限定されない。 First, the fuel cell system of the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1 is a structural example of the fuel cell system of the present invention, and FIG. 2 is a cross-sectional view schematically showing a solid polymer fuel cell.
As shown in FIG. 2, the fuel cell 9 has a fuel electrode 2 bonded to one surface of the solid polymer electrolyte membrane 1 and an oxidant electrode 3 bonded to the other surface, and a pair of separators 4, 5 on the outside thereof. It consists of a stack formed by stacking a plurality of single cells sandwiched between. The separators 4 and 5 include a fuel gas flow path 6 for supplying hydrogen to the fuel electrode 2, an oxidant gas flow path 7 for supplying oxygen to the oxidant electrode 3, and a cooling medium flow path 8 through which the cooling medium flows. Is formed. As shown in FIG. 2, the polymer electrolyte fuel cells are usually stacked in the horizontal direction with the single cells standing vertically. In the present invention, the stacking direction of the fuel cells is the vertical direction of the single cells. It is not limited to the direction of stacking in the horizontal direction in an upright state.

燃料電池９には、この燃料電池９の温度が発電に伴って上昇し、燃料電池の作動温度範囲を超えないようにするため冷却システムが備えられている。図１は、２つの冷却系統を設けた場合の冷却システムである。燃料電池９を冷却する冷却媒体は、循環ポンプ１０、１１により昇圧されてラジエータ１２、１３に供給され、ラジエータ１２、１３において外部に放熱することにより冷却される。その後冷却された冷却媒体は、冷却媒体流路入口部から燃料電池９に供給され、燃料電池９内の冷却媒体流路を通流しながら、燃料電池９の熱を奪って燃料電池９を冷却する。冷却媒体流路出口部から排出された熱を吸収した冷却媒体は、循環ポンプ１０、１１を介してラジエーター１２、１３に供給され、再び冷却される。各冷却系統間には混合バルブ１４、１５を設けることができる。混合バルブを設けた場合には、混合バルブを通して冷却媒体を混合し、各冷却系統を通流する冷却媒体温度や各冷却系統を通流する冷却媒体間の温度差を調整することが可能である。なお、本発明においては冷却媒体として、水等の液体や、空気等の気体を使用することができる。   The fuel cell 9 is provided with a cooling system in order to prevent the temperature of the fuel cell 9 from being increased with power generation and exceeding the operating temperature range of the fuel cell. FIG. 1 shows a cooling system when two cooling systems are provided. The cooling medium for cooling the fuel cell 9 is boosted by the circulation pumps 10 and 11, supplied to the radiators 12 and 13, and cooled by radiating heat to the outside in the radiators 12 and 13. Thereafter, the cooled cooling medium is supplied to the fuel cell 9 from the inlet of the cooling medium flow path, and cools the fuel cell 9 by removing heat from the fuel cell 9 while flowing through the cooling medium flow path in the fuel cell 9. . The cooling medium that has absorbed the heat discharged from the cooling medium flow path outlet is supplied to the radiators 12 and 13 via the circulation pumps 10 and 11 and cooled again. Mixing valves 14 and 15 can be provided between the cooling systems. When the mixing valve is provided, it is possible to mix the cooling medium through the mixing valve and adjust the temperature difference between the cooling medium flowing through each cooling system and the temperature difference between the cooling medium flowing through each cooling system. . In the present invention, a liquid such as water or a gas such as air can be used as the cooling medium.

本発明は、反応ガスが通流する反応ガス流路及び冷却媒体が通流する冷却媒体流路を備える燃料電池システムであって、前記冷却媒体流路を、燃料電池の重力方向に関して位置が異なる２つ以上の流路領域に群分けし、当該冷却媒体流路を通流する冷却媒体の温度が、前記燃料電池の重力方向に関して下部側の流路領域ほど高いことを特徴とする燃料電池システムである。   The present invention is a fuel cell system including a reaction gas flow path through which a reaction gas flows and a cooling medium flow path through which a cooling medium flows, and the position of the cooling medium flow path is different with respect to the gravity direction of the fuel cell. A fuel cell system characterized in that the temperature of the cooling medium divided into two or more flow path regions and flowing through the coolant flow path is higher in the lower flow path region with respect to the gravity direction of the fuel cell. It is.

本発明では、まず、冷却媒体を通流させる燃料電池内の冷却媒体流路を、重力方向に関する位置が異なる２つ以上の流路領域に群分けをする。このときの群分けは、当該燃料電池内の重力方向における水分分布の状態等を考慮して行えばよい。ここで、本発明の燃料電池システムにおける冷却媒体流路の構成として、図３に示す冷却媒体流路を例示することができる。なお、図３ａは、冷却媒体流路を重力方向に関して２つの流路領域に群分けし、当該２つの流路領域に互いに独立した２つ冷却系統を設けた場合である。本発明において冷却媒体流路の群分けは、図３ａに示したような方法に限られず、例えば、重力方向に関する位置が異なる流路領域が２つ以上あれば、重力方向に関する位置が同じ群が２つ以上あってもよい。また、反応ガス流路は、図３ｂに示す形態（反応ガス流路の通流方向、入口及び出口の設置位置など）に限られない。   In the present invention, first, the coolant flow paths in the fuel cell through which the coolant flows are grouped into two or more flow path regions having different positions in the direction of gravity. The grouping at this time may be performed in consideration of the state of moisture distribution in the direction of gravity in the fuel cell. Here, as a configuration of the coolant flow path in the fuel cell system of the present invention, the coolant flow path shown in FIG. 3 can be exemplified. FIG. 3A shows a case where the cooling medium flow paths are divided into two flow path areas with respect to the direction of gravity, and two independent cooling systems are provided in the two flow path areas. In the present invention, the grouping of the cooling medium flow paths is not limited to the method shown in FIG. 3a. For example, if there are two or more flow path regions having different positions in the gravity direction, the groups having the same position in the gravity direction are included. There may be two or more. Further, the reaction gas flow path is not limited to the form shown in FIG. 3b (the flow direction of the reaction gas flow path, the installation positions of the inlet and the outlet, etc.).

本発明の燃料電池システムは、上記のように、各流路領域の重力方向に関する位置によって、流路領域の冷却媒体流路を通流する冷却媒体の温度を変えるものであり、冷却媒体流路を通流する冷却媒体の温度を流路領域ごとに効率良く制御し、さらに、広い温度範囲における燃料電池の運転を可能とするためには、冷却媒体流路を燃料電池の重力方向に関して群分けした前記の各流路領域に互いに独立した冷却系統を設け、前記燃料電池の重力方向に関して上部側の冷却系統よりも温度が高い冷却媒体を下部側の冷却系統に通流することが好ましい。このように、各流路領域に互いに独立した冷却系統を設けることによって、冷却系統ごとに冷却媒体の流量や冷却媒体流路入口部での温度等を調節することができるため、各流路領域を通流する冷却媒体の温度を容易に制御することが可能であり、従って、燃料電池面内の温度分布を容易に、且つ細かく形成することができ、燃料電池の運転条件に合わせて適した温度分布を形成することが可能である。また、冷却媒体の流量を調節しなくても、各冷却系統の冷却媒体流路入口部での温度を調節することによって、燃料電池面内に温度分布を形成することができるため、高負荷運転時にも十分な温度管理能力を発揮する。   The fuel cell system of the present invention changes the temperature of the cooling medium flowing through the cooling medium flow path in the flow path area according to the position of each flow path area in the direction of gravity as described above. In order to efficiently control the temperature of the coolant flowing through each flow path region and to enable operation of the fuel cell in a wide temperature range, the coolant flow paths are grouped with respect to the gravity direction of the fuel cell. It is preferable that a cooling system independent from each other is provided in each of the flow path regions, and a cooling medium having a temperature higher than that of the upper cooling system in the gravity direction of the fuel cell is passed through the lower cooling system. Thus, by providing independent cooling systems in each flow channel region, the flow rate of the cooling medium, the temperature at the inlet of the cooling medium flow channel, etc. can be adjusted for each cooling system. It is possible to easily control the temperature of the cooling medium flowing therethrough, so that the temperature distribution in the fuel cell surface can be easily and finely formed, and suitable for the operating conditions of the fuel cell. It is possible to form a temperature distribution. In addition, it is possible to form a temperature distribution in the fuel cell plane by adjusting the temperature at the cooling medium flow path inlet of each cooling system without adjusting the flow rate of the cooling medium. Demonstrate sufficient temperature management ability at times.

図３に示すような冷却流路の場合、上部流路領域Ａと下部流路領域Ｂをそれぞれ通流する冷却媒体ａ、ｂの温度Ｔａ及びＴｂは、Ｔａ＜Ｔｂとなるように制御される。各流路領域に図３のように独立した冷却系統が設けられている場合には、冷却系統の燃料電池の冷却媒体流路入口部に流入する時点で、下部流路領域Ｂの冷却媒体流路を通流する冷却媒体の温度を、上部流路領域Ａの冷却媒体流路を通流する冷却媒体の温度よりも高く（Ｔａ＜Ｔｂ）設定する。   In the case of the cooling channel as shown in FIG. 3, the temperatures Ta and Tb of the cooling media a and b flowing through the upper channel region A and the lower channel region B, respectively, are controlled so that Ta <Tb. . In the case where an independent cooling system is provided in each flow path region as shown in FIG. 3, the cooling medium flow in the lower flow path region B at the time of flowing into the cooling medium flow path inlet of the fuel cell of the cooling system. The temperature of the cooling medium flowing through the passage is set higher than the temperature of the cooling medium flowing through the cooling medium flow path in the upper flow path region A (Ta <Tb).

このように冷却媒体流路の重力方向における位置によって各冷却媒体流路を通流する冷却媒体の温度を設定することで、冷却される燃料電池面内に温度分布、すなわち重力方向に関して上部側では低く、下部側では高いという温度差を生じさせる。このとき、低温領域である重力方向上部側では、反応ガス中の水蒸気が凝縮しやすく、この凝縮した液状の水分が電極及び電解質膜を湿潤し、重力方向上部で発生しやすい電極及び電解質膜の乾燥を防止することができる。一方、高温領域である重力方向下部側では、電極及び電解質膜中の過剰な水分や未反応ガスと共に排出されるべき水分が反応ガス流路で凝縮してしまったような液状の水分などが、蒸発して水蒸気となりやすく、水蒸気となることで未反応ガスとともに排出されやくなるため、重力方向下部で発生しやすいフラッディングや排水性の問題を改善することができる。   Thus, by setting the temperature of the cooling medium flowing through each cooling medium flow path according to the position of the cooling medium flow path in the gravity direction, the temperature distribution in the cooled fuel cell surface, that is, on the upper side with respect to the gravity direction, The temperature difference is low and low on the lower side. At this time, water vapor in the reaction gas is likely to condense on the upper side in the gravity direction, which is a low temperature region, and this condensed liquid moisture wets the electrode and the electrolyte membrane, and the electrode and electrolyte membrane that is likely to be generated in the upper portion in the gravity direction. Drying can be prevented. On the other hand, on the lower side in the gravitational direction, which is a high temperature region, liquid moisture such as excessive moisture in the electrode and the electrolyte membrane or moisture that should be discharged together with the unreacted gas is condensed in the reaction gas channel, Evaporation tends to become water vapor, and since it becomes easy to be discharged together with unreacted gas by becoming water vapor, it is possible to improve the flooding and drainage problems that are likely to occur in the lower part of the direction of gravity.

以上のように、冷却媒体の温度をその通流する冷却媒体流路の重力方向に対する位置によって変えることにより、重力方向の上部側から下部側に向かうほど高くなる温度分布を燃料電池面内に形成することで、上部側では水分の凝縮、下部側では水分の蒸発をそれぞれ促し、燃料電池面内の水分分布が最適になるように調整することができる。各流路領域を通流する冷却媒体の温度は、冷却媒体流路領域の群分けの方法、燃料電池の構成、燃料電池の面積、発電量、電解質膜特性等の諸条件を考慮して設定すればよく、例えば、自動車用燃料電池において、図３のように２つの流路領域に群分けした場合には、上部流路領域Ａに通流させる冷却媒体の流路入口部温度と、下部冷却媒体流路Ｂに通流させる冷却媒体の流路入口部温度との間に１０〜２０℃程度の差を設けることが好ましい。   As described above, by changing the temperature of the cooling medium depending on the position of the flowing cooling medium flow path with respect to the direction of gravity, a temperature distribution that increases from the upper side to the lower side in the direction of gravity is formed in the fuel cell surface. By doing so, it is possible to promote the condensation of moisture on the upper side and the evaporation of moisture on the lower side, respectively, and adjust the moisture distribution in the fuel cell surface to be optimal. The temperature of the cooling medium flowing through each flow path area is set in consideration of conditions such as the method of grouping the cooling medium flow path areas, the configuration of the fuel cell, the area of the fuel cell, the amount of power generation, and the electrolyte membrane characteristics. For example, in a fuel cell for an automobile, when divided into two flow channel regions as shown in FIG. 3, the flow channel inlet temperature of the cooling medium to be passed through the upper flow channel region A and the lower It is preferable to provide a difference of about 10 to 20 ° C. with respect to the flow path inlet temperature of the cooling medium to be passed through the cooling medium flow path B.

冷却媒体流路入口部から燃料電池面内の冷却媒体流路に流入した冷却媒体は、燃料電池の発電に伴う熱を奪いながら冷却媒体流路を通流し冷却媒体流路出口部から排出されるため、冷却媒体の温度は冷却媒体流路入口側で低く、冷却媒体流路出口側で高くなる。その結果、冷却される燃料電池面内の温度分布も冷却媒体流路入口側の部分で低く、冷却媒体流路出口側の部分で高くなる。このような燃料電池面内における冷却媒体の通流方向の温度分布は、冷却媒体の流量を調節することにより調整することができる。例えば、冷却媒体流路入口側と出口側との温度差を大きくする、すなわち、出口側の温度を高くするには流量を小さくし、上記温度差を小さくする、すなわち、出口側の温度を低くするには流量を大きくすればよい。
以上のような冷却媒体の温度が冷却媒体入口側と冷却媒体出口側とで異なることを利用すれば、図４に示すような一系統の冷却系統により、冷却媒体流路を通流する冷却媒体の温度が、燃料電池の重力方向に関して下部側の流路領域ほど高くすることもできる。 The cooling medium that has flowed into the cooling medium flow path in the fuel cell surface from the cooling medium flow path inlet portion flows through the cooling medium flow path while removing heat associated with power generation of the fuel cell, and is discharged from the cooling medium flow path outlet portion. Therefore, the temperature of the cooling medium is low on the cooling medium flow path inlet side and high on the cooling medium flow path outlet side. As a result, the temperature distribution in the fuel cell surface to be cooled is also low at the cooling medium flow path inlet side and high at the cooling medium flow path outlet side. The temperature distribution in the flow direction of the cooling medium in the fuel cell plane can be adjusted by adjusting the flow rate of the cooling medium. For example, to increase the temperature difference between the cooling medium flow path inlet side and the outlet side, that is, to increase the temperature on the outlet side, decrease the flow rate and decrease the temperature difference, that is, lower the temperature on the outlet side. To do this, increase the flow rate.
By utilizing the fact that the temperature of the cooling medium as described above is different between the cooling medium inlet side and the cooling medium outlet side, the cooling medium flowing through the cooling medium flow path by a single cooling system as shown in FIG. Can be made higher in the flow path region on the lower side with respect to the gravity direction of the fuel cell.

燃料電池面内における不均一な水分分布には、上記のような重力方向のものと、反応ガス流路の上流側で乾燥しやすく、下流側で水分が過剰となる反応ガス流路の通流方向のものがある。例えば、図３に示すような冷却媒体流路と反応ガス流路の組み合わせにおいては、反応ガス流路の通流方向に関して上流側（以下、反応ガス流路上流側ということがある。）と重力方向上部、反応ガス流路下流側と重力方向下部が一致する（反応ガス流路の通流方向と重力方向が同じになる）。従って、冷却媒体流路の上部流路領域Ａと下部流路領域Ｂをそれぞれ通流する冷却媒体の温度を、Ｔａ＜Ｔｂとなるように制御することにより、重力方向上部及び反応ガス流路上流側では、水分が凝縮するため、電解質膜及び電極の乾燥を抑制することができ、それと同時に、重力方向下部及び反応流路下流側では、過剰な水分が水蒸気となって排出されやすくなり、重力方向及び反応ガス流路の通流方向に関する水分分布を同時に調整することができる。   Non-uniform moisture distribution in the fuel cell plane is the same as in the gravity direction as described above, and the flow through the reaction gas channel that tends to dry on the upstream side of the reaction gas channel and excessive moisture on the downstream side. There are directional ones. For example, in the combination of the coolant flow path and the reactive gas flow path as shown in FIG. 3, the upstream side (hereinafter sometimes referred to as the reactive gas flow path upstream side) and gravity with respect to the flow direction of the reactive gas flow path. The upper part of the direction, the downstream side of the reaction gas channel, and the lower part of the gravity direction coincide (the flow direction of the reaction gas channel and the direction of gravity are the same). Therefore, by controlling the temperature of the cooling medium flowing through the upper flow path area A and the lower flow path area B of the cooling medium flow path so that Ta <Tb, the gravity direction upper part and the reaction gas flow path upstream Since moisture condenses on the side, drying of the electrolyte membrane and the electrode can be suppressed, and at the same time, excess moisture tends to be discharged as water vapor at the lower part in the direction of gravity and downstream of the reaction channel. The moisture distribution with respect to the direction and the flow direction of the reaction gas channel can be adjusted simultaneously.

一方、反応ガス流路の通流方向が重力方向と異なる関係にあるような場合には、燃料電池面内に重力方向の水分分布と反応ガス流路通流方向の水分分布とがそれぞれ形成される。従って、電極及び電解質膜は、重力方向上部に位置する流路領域の中でも反応ガス流路の上流側に位置する部分で特に乾燥しやすくなり、重力方向下部に位置する流路領域の中でも反応ガス流路の下流側に位置する部分で特に水分が過剰となり、フラッディングが発生しやすくなる。このような問題を改善するためには、低温領域とする重力方向上部の中でも反応ガス流路の上流側に位置する部分を特に低温にし、一方、高温領域とする重力方向下部の中でも反応ガス流路の下流側に位置する部分を特に高温にする必要がある。生成水によるフラッディングの発生をより効果的に抑制できる点から、反応ガス流路の通流方向として、電気化学反応により水が生成する電極側に供給される反応ガスの反応ガス流路の通流方向を考慮して、このような温度制御をすることが好ましい。   On the other hand, when the flow direction of the reaction gas channel is different from the gravity direction, a moisture distribution in the gravity direction and a moisture distribution in the reaction gas channel flow direction are formed in the fuel cell surface. The Therefore, the electrode and the electrolyte membrane are particularly easy to dry in a portion located on the upstream side of the reaction gas flow passage in the flow passage region located in the upper part in the gravity direction, and the reaction gas in the flow passage region located in the lower portion in the gravity direction. In particular, moisture is excessive at the portion located on the downstream side of the flow path, and flooding is likely to occur. In order to remedy such a problem, the portion located on the upstream side of the reaction gas flow path in the upper part of the gravity direction in the low temperature region is made particularly low temperature, while the reaction gas flow also in the lower part of the gravity direction in the high temperature region. The part located on the downstream side of the path needs to have a particularly high temperature. Since the generation of flooding due to the generated water can be more effectively suppressed, the flow direction of the reaction gas channel is the flow direction of the reaction gas channel supplied to the electrode side where water is generated by the electrochemical reaction. It is preferable to perform such temperature control in consideration of the direction.

すなわち、本発明の燃料電池冷却システムにおいて、燃料電池面内に重力方向の温度分布を形成すると同時に、反応ガス流路の通流方向の温度分布を形成するためには、上記のように前記冷却媒体流路を前記燃料電池の重力方向に関して２つ以上の流路領域に群分けすると共に、さらに、生成水を発生する電極側の反応ガス流路の通流方向に関して位置が異なる２つ以上の流路領域に群分けし、前記重力方向に関して群分けされた少なくとも１つの流路領域において、当該冷却媒体流路を通流する冷却媒体の温度が、前記反応ガス流路の通流方向に関して下流側の流路領域ほど高くすることが好ましい。   That is, in the fuel cell cooling system of the present invention, in order to form the temperature distribution in the gravity direction in the fuel cell surface and at the same time to form the temperature distribution in the flow direction of the reaction gas channel, the cooling is performed as described above. The medium flow paths are grouped into two or more flow path regions with respect to the gravitational direction of the fuel cell, and two or more different positions with respect to the flow direction of the reaction gas flow path on the electrode side that generates the generated water. In at least one flow channel region that is grouped into flow channel regions and grouped with respect to the direction of gravity, the temperature of the cooling medium flowing through the cooling medium flow channel is downstream with respect to the flow direction of the reaction gas flow channel. It is preferable that the flow path region on the side is made higher.

低温領域である重力方向上部の冷却媒体流路において、通流する冷却媒体の温度を反応ガス流路の上流側ほど低くすることによって、重力方向上部の中でも反応ガス流路の上流側で反応ガス中の水蒸気が凝縮しやすくなり、電極及び電解質膜の乾燥を防止することができる。一方、高温領域である重力方向に対して下部側の冷却媒体流路において、冷却媒体の温度を反応ガス流路の下流側ほど高くすることによって、重力方向下部の中でも反応ガス流路の下流側で電極及び電解質膜の過剰な水分や、未反応ガスと共に排出されるべき水分が反応ガス流路で凝縮してしまったような液状の水分等が、蒸発して水蒸気となりやすくなるため、フラッディングや排水性の問題を改善することができる。
燃料電池全面に亘って良好な水分分布を形成するためには、上記燃料電池の重力方向に関して群分けされた全ての流路領域において、各冷却媒体流路を通流する冷却媒体温度を上記のように反応ガス流路の通流方向を考慮して制御することが好ましい。 In the cooling medium flow path in the upper part of the gravity direction that is a low temperature region, the temperature of the flowing cooling medium is lowered toward the upstream side of the reaction gas flow path, so that the reaction gas on the upstream side of the reaction gas flow path in the upper part of the gravity direction. Water vapor therein is easily condensed, and drying of the electrode and the electrolyte membrane can be prevented. On the other hand, in the cooling medium flow path on the lower side with respect to the gravity direction, which is a high temperature region, the temperature of the cooling medium is increased toward the downstream side of the reaction gas flow path, so In this case, excessive moisture in the electrode and electrolyte membrane, or liquid moisture in which moisture that should be discharged together with the unreacted gas is condensed in the reaction gas flow path is easily evaporated to become water vapor. The problem of drainage can be improved.
In order to form a good moisture distribution over the entire surface of the fuel cell, the temperature of the cooling medium flowing through each cooling medium flow path is set to the above-described temperature in all flow path regions grouped in the gravity direction of the fuel cell. Thus, it is preferable to control in consideration of the flow direction of the reaction gas flow path.

燃料電池面内に重力方向の温度分布を形成すると共に、反応ガス流路の通流方向の温度分布を形成する方法は特に限られないが、冷却媒体の温度が冷却媒体流路の入口側と冷却媒体流路の出口側とで異なることを利用することができる。上述したように、冷却媒体は、燃料電池の熱を奪いながら冷却媒体流路を通流するため、冷却媒体の温度は冷却媒体入口側で低く、冷却媒体出口側で高くなる。すなわち、前記冷却媒体流路を前記重力方向に関して群分けした少なくとも１つの流路領域において、当該冷却媒体流路を通流する冷却媒体の温度が、前記生成水を発生する電極側の反応ガス流路の通流方向に関して下流側ほど高くなるように、前記反応ガス流路の通流方向に関して上流側に前記冷却媒体流路の入口部を設け、前記反応ガス流路の通流方向に関して下流側に前記冷却媒体流路の出口部を設けることが好ましい。また、冷却媒体流路を前記燃料電池の重力方向に関して群分けした前記の各流路領域に互いに独立した冷却系統を設けた場合には、当該冷却系統の少なくとも１つにおいて、各冷却系統の流路入口部を前記反応ガス流路の通流方向に関して上流側に設け、各冷却系統の流路出口部を前記反応ガス流路の下流側に設けることが好ましい。
特に、燃料電池面内の全面に亘って良好な水分分布を形成するためには、燃料電池の重力方向に関して群分けされた全ての流路領域又は各流路領域に設けられた互いに独立した全ての冷却系統において、反応ガス流路の通流方向を考慮した上記のような冷却媒体流路を設けることが好ましい。 The method of forming the temperature distribution in the gravitational direction in the fuel cell surface and the temperature distribution in the flow direction of the reaction gas flow path is not particularly limited, but the temperature of the cooling medium is different from the inlet side of the cooling medium flow path. The difference between the outlet side of the cooling medium flow path can be utilized. As described above, since the cooling medium flows through the cooling medium flow path while taking the heat of the fuel cell, the temperature of the cooling medium is low on the cooling medium inlet side and high on the cooling medium outlet side. That is, in at least one flow path region in which the cooling medium flow paths are grouped with respect to the direction of gravity, the temperature of the cooling medium flowing through the cooling medium flow path is such that the reaction gas flow on the electrode side that generates the generated water An inlet portion of the cooling medium flow path is provided on the upstream side with respect to the flow direction of the reaction gas flow path so that the downstream side becomes higher with respect to the flow direction of the flow path, and the downstream side with respect to the flow direction of the reaction gas flow path It is preferable to provide an outlet portion of the cooling medium flow path. Further, in the case where an independent cooling system is provided in each flow path region in which the cooling medium flow paths are grouped with respect to the gravitational direction of the fuel cell, the flow of each cooling system is provided in at least one of the cooling systems. It is preferable that the passage inlet is provided on the upstream side with respect to the flow direction of the reaction gas passage, and the passage outlet of each cooling system is provided on the downstream side of the reaction gas passage.
In particular, in order to form a good moisture distribution over the entire surface of the fuel cell, all the flow channel regions grouped in the gravity direction of the fuel cell or all the independent flow channels provided in each flow channel region In this cooling system, it is preferable to provide the cooling medium flow path as described above in consideration of the flow direction of the reaction gas flow path.

このような冷却媒体流路としては、図５を例示することができる。なお、図５は、２つの冷却流路に互いに独立した冷却系統を設けた場合の例である。上部流路領域Ａと下部流路領域Ｂを通流する冷却媒体ａ、ｂの温度は、冷却系統の流路入口部においてＴain＜Ｔbinに制御され、各冷却系統の流路入口部は反応ガス流路の上流側に設け、流路出口部は反応ガス流路の下流側に設けられている。図５において、下部流路領域Ｂを通流する冷却媒体ｂの流路入口部温度Ｔbinは、上部流路領域Ａを通流して温度が上昇した冷却媒体ａの流路出口部における温度Ｔaoutよりも高くすることが好ましい。   As such a cooling medium flow path, FIG. 5 can be illustrated. FIG. 5 shows an example in which two cooling channels are provided with independent cooling systems. The temperatures of the cooling media a and b flowing through the upper flow path area A and the lower flow path area B are controlled to Tain <Tbin at the flow path inlet of the cooling system, and the flow path inlet of each cooling system has a reaction gas. Provided on the upstream side of the flow path, the flow path outlet is provided on the downstream side of the reaction gas flow path. In FIG. 5, the flow path inlet temperature Tbin of the cooling medium b flowing through the lower flow path area B is higher than the temperature Taout at the flow path outlet of the cooling medium a that has increased in temperature through the upper flow path area A. It is preferable to increase the height.

燃料電池面内の冷却媒体流路の入口側で冷却媒体温度が低く、出口側で冷却媒体温度が高くなるという温度分布は、冷却媒体の流量を調節等することにより調整することができる。例えば、出口側の温度を高くするには流量を小さくし、出口側の温度を低くするには流量を大きくすればよい。また、冷却媒体の冷却媒体流路の入口部温度及び出口部温度は、冷却媒体流路の群分けの方法、燃料電池の構成、燃料電池の面積、発電量、電解質膜特性等の諸条件を考慮して設定すればよいが、例えば、自動車用燃料電池においては、同一流路領域内又は同一冷却系統内の冷却媒体の流路入口部温度と流路出口部温度との間に１０〜２０℃程度の温度差を設けることが好ましい。   The temperature distribution in which the cooling medium temperature is low on the inlet side of the cooling medium flow path in the fuel cell surface and the cooling medium temperature is high on the outlet side can be adjusted by adjusting the flow rate of the cooling medium. For example, the flow rate may be reduced to increase the temperature on the outlet side, and the flow rate may be increased to decrease the temperature on the outlet side. In addition, the inlet temperature and outlet temperature of the cooling medium flow path of the cooling medium depend on various conditions such as the grouping method of the cooling medium flow path, the configuration of the fuel cell, the area of the fuel cell, the amount of power generation, and the characteristics of the electrolyte membrane. For example, in a fuel cell for an automobile, 10 to 20 between the flow path inlet part temperature and the flow path outlet part temperature of the cooling medium in the same flow path region or the same cooling system. It is preferable to provide a temperature difference of about ° C.

冷却媒体流路を燃料電池の重力方向に関して群分けした複数の流路領域において、反応ガス流路の上流側に冷却媒体流路の入口部、下流側に冷却媒体流路の出口部を設ける場合、各流路領域間の冷却媒体の流路入口部温度差、及び各流路領域間の冷却媒体の流路出口部温度差は、上記のような燃料電池の諸条件に応じて設定すればよいが、電極や電解質膜の乾燥又はフラッディング等の発生をより効果的に抑制できる観点から、前記燃料電池の重力方向に関して最も上部側に位置する流路領域の冷却媒体流路の入口部における冷却媒体温度と、前記燃料電池の重力方向に対して最も下部側に位置する流路領域の冷却媒体流路の入口部における冷却媒体温度との差が１０〜２０℃であり、前記燃料電池の重力方向に対して最も上部側に位置する流路領域の冷却媒体流路の出口部における冷却媒体温度と、前記燃料電池の重力方向に対して最も下部側に位置する流路領域の冷却媒体流路の出口部における冷却媒体温度との差が１０〜２０℃であるように各流路領域の冷却媒体流路を通流する冷却媒体の温度を制御することが好ましい。前記冷却媒体流路を前記燃料電池の重力方向に関して群分けした前記の各流路領域に互いに独立した冷却系統を設けた場合には、前記冷却媒体流路を前記燃料電池の重力方向に関して群分けした前記の各流路領域に互いに独立した冷却系統を設け、前記燃料電池の重力方向に関して最も上部側に位置する流路領域に設けられた冷却系統の流路入口部における冷却媒体温度と、前記燃料電池の重力方向に対して最も下部側に位置する流路領域に設けられた冷却系統の流路の入口部における冷却媒体温度との差が１０〜２０℃であり、前記燃料電池の重力方向に対して最も上部側に位置する流路領域に設けられた冷却系統の流路出口部における冷却媒体温度と、前記燃料電池の重力方向に対して最も下部側に位置する流路領域に設けられた冷却系統の流路出口部における冷却媒体温度との差が１０〜２０℃であるように各冷却系統の冷却媒体流路を通流する冷却媒体の温度を制御することが好ましい。   In a plurality of flow channel regions in which the coolant flow channels are grouped with respect to the gravity direction of the fuel cell, an inlet portion of the coolant flow channel is provided on the upstream side of the reaction gas flow channel, and an outlet portion of the coolant flow channel is provided on the downstream side. The temperature difference between the flow path inlets of the cooling medium between the flow path areas and the temperature difference between the flow path outlets of the cooling medium between the flow path areas may be set according to the various conditions of the fuel cell as described above. However, from the viewpoint of more effectively suppressing the occurrence of electrode or electrolyte membrane drying or flooding, cooling at the inlet portion of the cooling medium flow channel in the flow channel region located on the uppermost side in the gravity direction of the fuel cell. The difference between the medium temperature and the cooling medium temperature at the inlet of the cooling medium flow path in the flow path region located on the lowermost side with respect to the gravity direction of the fuel cell is 10 to 20 ° C., and the gravity of the fuel cell Located at the top of the direction The difference between the cooling medium temperature at the outlet of the cooling medium flow path in the path region and the cooling medium temperature at the outlet of the cooling medium flow path in the flow path region located on the lowermost side with respect to the gravity direction of the fuel cell is It is preferable to control the temperature of the cooling medium flowing through the cooling medium flow path in each flow path region so as to be 10 to 20 ° C. When the cooling medium channels are grouped in the gravity direction of the fuel cell, the cooling medium channels are grouped in the gravity direction of the fuel cell. A cooling system that is independent of each other in each of the flow channel regions, and a cooling medium temperature at a flow channel inlet portion of the cooling system provided in a flow channel region that is located on the uppermost side in the gravity direction of the fuel cell, The difference between the coolant temperature at the inlet of the flow path of the cooling system provided in the flow path region located on the lowest side with respect to the gravity direction of the fuel cell is 10 to 20 ° C., and the gravity direction of the fuel cell With respect to the cooling medium temperature at the channel outlet of the cooling system provided in the channel region located on the uppermost side and the channel region located on the lowest side with respect to the gravitational direction of the fuel cell. Cooling system It is preferable that the difference of the cooling medium temperature and in the flow path outlet part of controlling the temperature of the cooling medium flowing through the cooling medium flow path of the cooling system to be a 10 to 20 ° C..

また、冷却系統は異なるが重力方向に対する上下位置が同じ２つ以上の流路領域に互いに独立した冷却系統を設けている場合には、より反応ガス流路の下流側に位置する冷却媒体流路を有する冷却系統の冷却媒体入口温度ほど高くすることによって、上記したような反応ガス流路の通流方向に対する温度分布を形成することができる。   In addition, when two independent cooling systems are provided in two or more flow path regions that have different cooling systems but have the same vertical position with respect to the direction of gravity, the cooling medium flow path positioned more downstream of the reaction gas flow path By increasing the cooling medium inlet temperature of the cooling system having a temperature distribution as described above, the temperature distribution in the flow direction of the reaction gas channel can be formed.

なお、本発明において、冷却媒体流路の具体的な形態は特に限定されるものではなく、図に示した場合に限られないが、当該冷却媒体流路が隣接する反応ガス流路の形態によって水分が凝縮しやすい部分、電極及び電解質膜が乾燥しやすい部分は異なってくるため、重力方向下部側の流路領域ほど高温の冷却媒体を通流させる、或いは、重力方向下部側の流路領域ほど高温の冷却媒体を通流させると共に、反応ガス流路下流側ほど高温の冷却媒体を通流させた上で、反応ガス流速が小さい部分、反応ガス流路のターン部等、水分が凝縮しやすい部分に高温の冷却媒体が流れるように、冷却媒体流路を設定することが好ましい。   In the present invention, the specific form of the cooling medium flow path is not particularly limited and is not limited to the case shown in the figure, but depending on the form of the reaction gas flow path adjacent to the cooling medium flow path. Since the portion where moisture tends to condense and the portion where the electrode and electrolyte membrane tend to dry are different, the flow medium at the lower side in the direction of gravity passes through a higher temperature cooling medium, or the channel region at the lower side of the direction of gravity. The higher the temperature of the reaction medium, the lower the reaction gas flow path, and the lower the reaction gas flow path. It is preferable to set the cooling medium flow path so that the high-temperature cooling medium flows through the easy-to-use part.

本発明では、さらにフラッディングの発生を防止するために、電気化学反応により生成水を発生する電極側の反応ガス流路の下流側が、当該反応ガス流路の通流方向の上流側から下流側に向かって直線状に規制されていることが好ましい。このように、反応ガス流路の下流側において、反応ガスが流路と流路との間に回り込めるような部分のない反応ガス流路とすることによって、凝縮した生成水等の過剰な液体状の水分をガス圧によって速やかに燃料電池外に押し出し、排出することができる。このような反応ガス流路の形態としては、図３ａに示す冷却媒体流路を設ける場合には、図６に示すような形態が挙げられる。図６において反応ガス流路の上流側は、圧力損出防止の点から隔壁の平面配置が格子状であり、上流側から下流側に向かって平行に設けられた複数の流路と、当該上流側から下流側に向かって平行に設けられている流路と直交する複数の流路（バイパス流路）が設けられている。反応ガス流路の下流側の隔壁を上流側と同じように格子状配置とした場合には、凝縮した生成水等がバイパス流路に回りこみやすく、これら生成水の排出性が悪くなる。そのため、反応ガス流路の下流側を図６のように横方向へのバイパスがない直線状に形成することにより、反応ガス等の回りこみが発生しない、排水性に優れた反応ガス流路とすることができる。   In the present invention, in order to further prevent the occurrence of flooding, the downstream side of the reaction gas flow path on the electrode side that generates water by electrochemical reaction is changed from the upstream side in the flow direction of the reaction gas flow path to the downstream side. It is preferable that the straight line is regulated. In this way, an excess liquid such as condensed product water is formed on the downstream side of the reaction gas flow path by providing a reaction gas flow path that does not have a portion in which the reaction gas can wrap around between the flow paths. The moisture in the form can be quickly pushed out of the fuel cell by the gas pressure and discharged. As a form of such a reactive gas flow path, when the cooling medium flow path shown in FIG. In FIG. 6, the upstream side of the reaction gas channel has a lattice-like planar arrangement from the viewpoint of preventing pressure loss, and includes a plurality of channels provided in parallel from the upstream side to the downstream side, A plurality of channels (bypass channels) perpendicular to the channels provided in parallel from the side toward the downstream side are provided. If the partition walls on the downstream side of the reaction gas channel are arranged in a lattice pattern as in the upstream side, condensed product water or the like easily flows into the bypass channel, and the discharge of these product waters deteriorates. Therefore, by forming the downstream side of the reaction gas channel in a straight line having no bypass in the lateral direction as shown in FIG. can do.

以上のように、本発明の燃料電池システムは、燃料電池面内に温度分布を形成することによって燃料電池面内の水分分布を最適化し、電極及び電解質膜の部分的な乾燥及びフラッディングを防止することができる。従って、電燃料電池全面に亘って、高い発電性能を発揮する燃料電池とすることが可能である。   As described above, the fuel cell system of the present invention optimizes the moisture distribution in the fuel cell surface by forming a temperature distribution in the fuel cell surface, and prevents partial drying and flooding of the electrode and the electrolyte membrane. be able to. Therefore, it is possible to obtain a fuel cell that exhibits high power generation performance over the entire surface of the electrofuel cell.

（実験例）
＜膜／電極接合体の作製＞
白金を重量比で４０％担持したカーボン１４ｇと市販のナフィオン５重量％溶液（Ａｌｄｒｉｃｈ社製）２００ｇとを混練し、電極インクを調製した。カーボンクロス（厚み３００μｍ、Ｅ−ｔｅｋ社製、ＬＴ１４００Ｗ）の表面に、白金塗布量が０．５ｍｇ／ｃｍ２になるように、得られた電極インクを塗布・乾燥することによって、電極を形成した。得られた電極２枚で、電極インクの塗布面が電解質膜側となるように電解質膜（厚さ５０μｍ、ナフィオン膜Ｎ１１２、ＤｕＰｏｎｔ製）を挟み、加熱プレス（１２０℃、圧力０．１ＭＰａ、２０分）することによって膜／電極接合体とした。 (Experimental example)
<Preparation of membrane / electrode assembly>
14 g of carbon carrying 40% by weight of platinum and 200 g of a commercially available 5% by weight Nafion solution (manufactured by Aldrich) were kneaded to prepare an electrode ink. The electrode was formed by applying and drying the obtained electrode ink on the surface of a carbon cloth (thickness 300 μm, manufactured by E-tek, LT1400W) so that the platinum coating amount was 0.5 mg / cm 2 . . An electrolyte membrane (thickness 50 μm, Nafion membrane N112, manufactured by DuPont) is sandwiched between the two obtained electrodes so that the electrode ink application surface is on the electrolyte membrane side, and heated press (120 ° C., pressure 0.1 MPa, 20 To obtain a membrane / electrode assembly.

＜発電評価試験＞
得られた膜／電極接合体を用いて、図２に示すようなスタックを構成する燃料電池評価用単セルを組立て、燃料ガスとして加湿した水素ガス、酸化剤ガスとして加湿した空気ガスを用い、セル温度一定（６０℃、７０℃、８０℃、９０℃）とし、以下の条件で発電試験を行った。
燃料ガス（水素ガス）：流量０．５Ｌ／ｍｉｎ、加湿温度６０℃
酸化剤ガス（空気ガス）：流量１Ｌ／ｍｉｎ、加湿温度６０℃
電極面積：２５ｃｍ２ <Power generation evaluation test>
Using the obtained membrane / electrode assembly, a unit cell for fuel cell evaluation constituting a stack as shown in FIG. 2 was assembled, using a humidified hydrogen gas as a fuel gas, a humidified air gas as an oxidant gas, The cell temperature was constant (60 ° C., 70 ° C., 80 ° C., 90 ° C.), and the power generation test was performed under the following conditions.
Fuel gas (hydrogen gas): flow rate 0.5L / min, humidification temperature 60 ° C
Oxidant gas (air gas): flow rate 1 L / min, humidification temperature 60 ° C
Electrode area: 25 cm 2

＜試験結果＞
結果を図６、図７に示す。セル内温度を６０℃にした場合、０．８Ａ／ｃｍ2まで運転することができた。一方、セル内温度を７０℃とした場合には、０．５Ａ／ｃｍ2より高負荷域では、生成水の凝縮により重度のフラッディングが発生し、運転することができなかった。セル内温度を６０℃から７０℃に高くしたにもかかわらず、フラッディングが発生したのは、温度を高くすることによって重力方向上部側の電極及び電解質膜が乾燥したために発電面積が減少し、その結果、生成水が重力方向下部側において局所的に発生し、この生成水が蒸発するほどセル温度が高温ではなかったためと考えられる。 <Test results>
The results are shown in FIGS. When the temperature in the cell was 60 ° C., the cell could be operated up to 0.8 A / cm 2 . On the other hand, when the temperature in the cell was set to 70 ° C., in the load range higher than 0.5 A / cm 2 , heavy flooding occurred due to condensation of the produced water, and operation was not possible. Despite the fact that the temperature inside the cell was increased from 60 ° C. to 70 ° C., the flooding occurred because the electrode and the electrolyte membrane on the upper side in the gravitational direction were dried by increasing the temperature. As a result, it is considered that the generated water was locally generated on the lower side in the direction of gravity and the cell temperature was not so high that the generated water evaporated.

また、セル内温度を８０℃とした場合には、０．６Ａ／ｃｍ2までは良好な発電性能を示していたが、０．６Ａ／ｃｍ2より高負荷域で急激に発電性能が低下した。これは、セル内温度を７０℃とした場合と比べて局所的に発生した生成水が蒸発しやすくなったため、フラッディングの程度は軽くなったものの、高負荷域では、重力方向上部側での電極及び電解質膜の乾燥がひどくなり、発電面積が減少したためと考えられる。また、他のセル温度と比較して、セル温度を９０℃とした場合では、低負荷域から高負荷域まで、特に高負荷域において、発電性能が低くかった。
以上の結果により、本発明のように燃料電池のセル温度を重力方向下部に位置する部分ほど高めに設定することによって、重力方向での水分分布を制御し、重力方向上部での電極及び電解質膜の乾燥を防止すると同時に、重力方向で発生しやすいフラッディングを抑制することが可能であることがわかる。 In the case where the cell temperature was 80 ° C., although up to 0.6 A / cm 2 showed good power generation performance, rapid power generation performance is lowered in the high load region than 0.6 A / cm 2 . This is because the locally generated water is easier to evaporate than in the case where the temperature in the cell is set to 70 ° C., but the degree of flooding is reduced, but in the high load region, the electrode on the upper side in the gravity direction This is thought to be because the electrolyte membrane became so dry that the power generation area was reduced. Further, when the cell temperature was 90 ° C., the power generation performance was low from the low load region to the high load region, particularly in the high load region, as compared with other cell temperatures.
Based on the above results, by setting the cell temperature of the fuel cell higher in the lower part of the gravitational direction as in the present invention, the moisture distribution in the gravitational direction is controlled, and the electrode and electrolyte membrane in the upper part of the gravitational direction are controlled. It can be seen that it is possible to prevent flooding that tends to occur in the direction of gravity and at the same time to prevent drying.

本発明の燃料電池システムの一構成例を示す図である。It is a figure which shows one structural example of the fuel cell system of this invention. 固体高分子型燃料電池の概略を模式的に示した断面図である。It is sectional drawing which showed the outline of the polymer electrolyte fuel cell typically. 本発明の燃料電池システムにおける冷却媒体流路（３ａ）と反応ガス流路（３ｂ）の一構成例を示す図である。It is a figure which shows one structural example of the coolant flow path (3a) and the reaction gas flow path (3b) in the fuel cell system of this invention. 本発明の燃料電池システムにおける冷却媒体流路の一形態例を示す図である。It is a figure which shows one example of a cooling medium flow path in the fuel cell system of this invention. 本発明の燃料電池システムにおける冷却媒体流路の一形態例を示す図である。It is a figure which shows one example of a cooling medium flow path in the fuel cell system of this invention. 本発明の反応ガス流路の一形態例を示す図である。It is a figure which shows one example of the reaction gas flow path of this invention. 実験例における発電試験結果を示す図である。It is a figure which shows the electric power generation test result in an experiment example. 実験例における発電試験結果を示す図である。It is a figure which shows the electric power generation test result in an experiment example.

符号の説明Explanation of symbols

１…固体高分子電解質膜
２…燃料極
３…酸化剤極
４…セパレータ
５…セパレータ
６…燃料ガス流路
７…酸化剤ガス流路
８…冷却媒体流路
９…燃料電池
１０…循環ポンプ
１１…循環ポンプ
１２…ラジエータ
１３…ラジエータ
１４…混合バルブ
１５…混合バルブ DESCRIPTION OF SYMBOLS 1 ... Solid polymer electrolyte membrane 2 ... Fuel electrode 3 ... Oxidant electrode 4 ... Separator 5 ... Separator 6 ... Fuel gas flow path 7 ... Oxidant gas flow path 8 ... Cooling medium flow path 9 ... Fuel cell 10 ... Circulation pump 11 ... circulation pump 12 ... radiator 13 ... radiator 14 ... mixing valve 15 ... mixing valve

Claims (8)

反応ガスが通流する反応ガス流路及び冷却媒体が通流する冷却媒体流路を備える燃料電池システムであって、前記冷却媒体流路を、燃料電池の重力方向に関して位置が異なる２つ以上の流路領域に群分けし、当該冷却媒体流路を通流する冷却媒体の温度が、前記燃料電池の重力方向に関して下部側の流路領域ほど高いことを特徴とする燃料電池システム。   A fuel cell system comprising a reaction gas flow path through which a reaction gas flows and a cooling medium flow path through which a cooling medium flows, wherein the cooling medium flow path has two or more positions different from each other in the gravity direction of the fuel cell. A fuel cell system, characterized in that the temperature of the cooling medium divided into flow path regions and flowing through the cooling medium flow channel is higher in the lower flow path region in the gravity direction of the fuel cell. 前記冷却媒体流路を前記燃料電池の重力方向に関して群分けした前記の各流路領域に互いに独立した冷却系統を設け、前記燃料電池の重力方向に関して上部側の冷却系統よりも温度が高い冷却媒体を下部側の冷却系統に通流する、請求項１に記載の燃料電池システム。   A cooling system independent of each other is provided in each of the flow path regions in which the cooling medium flow paths are grouped with respect to the gravity direction of the fuel cell, and the cooling medium has a higher temperature than the upper cooling system in the gravity direction of the fuel cell. The fuel cell system according to claim 1, wherein the fuel cell system is passed through a cooling system on a lower side. 前記冷却媒体流路を前記燃料電池の重力方向に関して２つ以上の流路領域に群分けすると共に、さらに、生成水を発生する電極側の反応ガス流路の通流方向に関して位置が異なる２つ以上の流路領域に群分けし、前記重力方向に関して群分けされた少なくとも１つの流路領域において、当該冷却媒体流路を通流する冷却媒体の温度が、前記反応ガス流路の通流方向に関して下流側の流路領域ほど高い、請求項１又は２に記載の燃料電池システム。   The cooling medium flow path is grouped into two or more flow path regions with respect to the gravitational direction of the fuel cell, and two positions different in the flow direction of the reaction gas flow path on the electrode side that generates the generated water. The temperature of the cooling medium flowing through the cooling medium flow path in at least one flow path area divided into the above flow path areas and grouped with respect to the direction of gravity is the flow direction of the reaction gas flow path. The fuel cell system according to claim 1, wherein the downstream flow path region is higher with respect to the fuel cell system. 前記冷却媒体流路を前記燃料電池の重力方向に関して群分けした少なくとも１つの流路領域において、当該冷却媒体流路を通流する冷却媒体の温度が、前記生成水を発生する電極側の反応ガス流路の通流方向に関して下流側ほど高くなるように、前記反応ガス流路の通流方向に関して上流側に前記冷却媒体流路の入口部を設け、前記反応ガス流路の通流方向に関して下流側に前記冷却媒体流路の出口部を設けた、請求項３に記載の燃料電池システム。   In at least one flow path region in which the cooling medium flow path is grouped with respect to the gravity direction of the fuel cell, the temperature of the cooling medium flowing through the cooling medium flow path is the reaction gas on the electrode side that generates the generated water An inlet portion of the cooling medium flow path is provided on the upstream side with respect to the flow direction of the reaction gas flow path so that the downstream side becomes higher with respect to the flow direction of the flow path, and downstream with respect to the flow direction of the reaction gas flow path. The fuel cell system according to claim 3, wherein an outlet of the cooling medium flow path is provided on a side. 前記冷却媒体流路を前記燃料電池の重力方向に関して群分けした前記の各流路領域に互いに独立した冷却系統を設け、当該冷却系統の少なくとも１つにおいて流路入口部を前記反応ガス流路の通流方向に関して上流側に設け、流路出口部を前記反応ガス流路の下流側に設けた、請求項４に記載の燃料電池システム。   An independent cooling system is provided in each of the flow path areas in which the cooling medium flow paths are grouped with respect to the direction of gravity of the fuel cell, and at least one of the cooling systems has a flow path inlet portion of the reaction gas flow path. The fuel cell system according to claim 4, wherein the fuel cell system is provided on the upstream side with respect to the flow direction, and the flow path outlet is provided on the downstream side of the reaction gas flow path. 生成水を発生する電極側の反応ガス流路の下流側が、当該反応ガス流路の通流方向の上流側から下流側に向かって直線状に規制された請求項１乃至５に記載の燃料電池システム。   6. The fuel cell according to claim 1, wherein a downstream side of the reaction gas passage on the electrode side that generates the generated water is linearly regulated from an upstream side to a downstream side in the flow direction of the reaction gas passage. system. 前記燃料電池の重力方向に関して最も上部側に位置する流路領域の冷却媒体流路の入口部における冷却媒体温度と、前記燃料電池の重力方向に対して最も下部側に位置する流路領域の冷却媒体流路の入口部における冷却媒体温度との差が１０〜２０℃であり、
前記燃料電池の重力方向に対して最も上部側に位置する流路領域の冷却媒体流路の出口部における冷却媒体温度と、前記燃料電池の重力方向に対して最も下部側に位置する流路領域の冷却媒体流路の出口部における冷却媒体温度との差が１０〜２０℃である、請求項４乃至６のいずれかに記載の燃料電池システム。 Cooling medium temperature at the inlet of the cooling medium flow path in the flow path area located on the uppermost side with respect to the gravitational direction of the fuel cell, and cooling of the flow path area located on the lowermost side with respect to the gravitational direction of the fuel cell The difference from the cooling medium temperature at the inlet of the medium flow path is 10 to 20 ° C.
The coolant temperature at the outlet of the coolant flow path in the flow path area located on the uppermost side with respect to the gravitational direction of the fuel cell, and the flow path area located on the lowermost side with respect to the gravitational direction of the fuel cell The fuel cell system according to any one of claims 4 to 6, wherein a difference from the cooling medium temperature at the outlet of the cooling medium flow path is 10 to 20 ° C. 前記冷却媒体流路を前記燃料電池の重力方向に関して群分けした前記の各流路領域に互いに独立した冷却系統を設け、前記燃料電池の重力方向に関して最も上部側に位置する流路領域に設けられた冷却系統の流路入口部における冷却媒体温度と、前記燃料電池の重力方向に対して最も下部側に位置する流路領域に設けられた冷却系統の流路の入口部における冷却媒体温度との差が１０〜２０℃であり、
前記燃料電池の重力方向に対して最も上部側に位置する流路領域に設けられた冷却系統の流路出口部における冷却媒体温度と、前記燃料電池の重力方向に対して最も下部側に位置する流路領域に設けられた冷却系統の流路出口部における冷却媒体温度との差が１０〜２０℃である、請求項７に記載の燃料電池システム。
An independent cooling system is provided in each of the flow path areas in which the cooling medium flow paths are grouped with respect to the gravity direction of the fuel cell, and is provided in the flow path area located on the uppermost side with respect to the gravity direction of the fuel cell. The cooling medium temperature at the flow path inlet of the cooling system and the cooling medium temperature at the flow path inlet of the cooling system provided in the flow path region located at the lowest side in the gravity direction of the fuel cell. The difference is 10-20 ° C.,
The cooling medium temperature at the flow path outlet of the cooling system provided in the flow path region located on the uppermost side with respect to the gravitational direction of the fuel cell, and located on the lowermost side with respect to the gravitational direction of the fuel cell. The fuel cell system according to claim 7, wherein a difference from a cooling medium temperature at a flow path outlet portion of a cooling system provided in the flow path region is 10 to 20 ° C.
JP2004154492A 2004-05-25 2004-05-25 Fuel cell system Pending JP2005339872A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2004154492A JP2005339872A (en) 2004-05-25 2004-05-25 Fuel cell system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2004154492A JP2005339872A (en) 2004-05-25 2004-05-25 Fuel cell system

Publications (1)

Publication Number Publication Date
JP2005339872A true JP2005339872A (en) 2005-12-08

Family

ID=35493209

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2004154492A Pending JP2005339872A (en) 2004-05-25 2004-05-25 Fuel cell system

Country Status (1)

Country Link
JP (1) JP2005339872A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009122256A2 (en) * 2008-03-31 2009-10-08 Toyota Jidosha Kabushiki Kaisha Fuel cell and fuel cell system
JP2012094256A (en) * 2010-10-25 2012-05-17 Toyota Motor Corp Fuel cell system and control method thereof
CN105870479A (en) * 2015-02-11 2016-08-17 福特全球技术公司 Fuel cell assembly with cooling system
JP2017076536A (en) * 2015-10-15 2017-04-20 本田技研工業株式会社 Fuel battery stack
DE102022103985B3 (en) 2022-02-21 2023-06-15 Audi Aktiengesellschaft Bipolar plate, fuel cell device and method for operating the fuel cell device

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009122256A2 (en) * 2008-03-31 2009-10-08 Toyota Jidosha Kabushiki Kaisha Fuel cell and fuel cell system
WO2009122256A3 (en) * 2008-03-31 2009-12-30 Toyota Jidosha Kabushiki Kaisha Fuel cell and fuel cell system
US20110097638A1 (en) * 2008-03-31 2011-04-28 Toyota Jidosha Kabushiki Kaisha Fuel cell and fuel cell system
US9281528B2 (en) 2008-03-31 2016-03-08 Toyota Jidosha Kabushiki Kaisha Fuel cell and fuel cell system
DE112009000942B4 (en) 2008-03-31 2022-06-09 Toyota Jidosha Kabushiki Kaisha Fuel cell and fuel cell system
JP2012094256A (en) * 2010-10-25 2012-05-17 Toyota Motor Corp Fuel cell system and control method thereof
US8785066B2 (en) 2010-10-25 2014-07-22 Toyota Jidosha Kabushiki Kaisha Fuel cell system and control method therefor
CN105870479A (en) * 2015-02-11 2016-08-17 福特全球技术公司 Fuel cell assembly with cooling system
CN105870479B (en) * 2015-02-11 2021-03-19 福特全球技术公司 Fuel cell assembly with cooling system
JP2017076536A (en) * 2015-10-15 2017-04-20 本田技研工業株式会社 Fuel battery stack
DE102022103985B3 (en) 2022-02-21 2023-06-15 Audi Aktiengesellschaft Bipolar plate, fuel cell device and method for operating the fuel cell device

Similar Documents

Publication Publication Date Title
US7579098B2 (en) Fuel cells evaporative reactant gas cooling and operational freeze prevention
KR102593276B1 (en) Humidifiers with integrated water separators for fuel cell systems, fuel cell systems and vehicles containing the same
US8304123B2 (en) Ambient pressure fuel cell system employing partial air humidification
JP2006509332A (en) Fuel cell system with improved humidification system
US7556879B2 (en) Polymer electrolyte fuel cell
JP3699063B2 (en) Fuel cell and control method thereof
WO2006071580A2 (en) Fuel cells evaporatively reactant gas cooling and operational freeze prevention
US20090053568A1 (en) Evaporative Cooling of Fuel Cells Employing Antifreeze Solution
KR20030019248A (en) Fuel cell
JP5287184B2 (en) Fuel cell system
JP2011018525A (en) Fuel cell and fuel cell system
JP2010129482A (en) Fuel cell separator, fuel cell stack, and fuel cell system
JP2005339872A (en) Fuel cell system
JP5385371B2 (en) Separation plate configuration of fuel cell
EP1422775B1 (en) Fuel cell with separator plates having comb-shaped gas passages
JP2008047395A (en) Fuel cell
JP4967199B2 (en) Fuel cell piping structure
JP5406207B2 (en) Adjustment of liquid water permeability in diffusion layer of fuel cell stack
JP2007294319A (en) Fuel cell system
JP7044564B2 (en) Fuel cell stack
CN114144913A (en) Humidifier, fuel cell device with humidifier, and motor vehicle
JP2013157315A (en) Fuel battery
JP2005149827A (en) Fuel cell
US7063907B2 (en) Passive water management system for a fuel cell power plant
JP4442253B2 (en) Humidifier, solid polymer electrolyte fuel cell using the humidifier, and operation method thereof