JP2003077518A - Fuel reforming device - Google Patents

Fuel reforming device

Info

Publication number
JP2003077518A
JP2003077518A JP2001270046A JP2001270046A JP2003077518A JP 2003077518 A JP2003077518 A JP 2003077518A JP 2001270046 A JP2001270046 A JP 2001270046A JP 2001270046 A JP2001270046 A JP 2001270046A JP 2003077518 A JP2003077518 A JP 2003077518A
Authority
JP
Japan
Prior art keywords
fuel
exhaust gas
hydrogen
flow rate
ultrasonic
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
JP2001270046A
Other languages
Japanese (ja)
Inventor
Hiroyuki Sakakibara
啓之 榊原
Masayoshi Sugino
正芳 杉野
Atsushi Ogino
温 荻野
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
Soken Inc
Original Assignee
Nippon Soken Inc
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 Nippon Soken Inc, Toyota Motor Corp filed Critical Nippon Soken Inc
Priority to JP2001270046A priority Critical patent/JP2003077518A/en
Publication of JP2003077518A publication Critical patent/JP2003077518A/en
Pending legal-status Critical Current

Links

Classifications

    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30Hydrogen technology
    • Y02E60/50Fuel cells

Landscapes

  • Fuel Cell (AREA)
  • Measuring Volume Flow (AREA)
  • Hydrogen, Water And Hydrids (AREA)

Abstract

PROBLEM TO BE SOLVED: To simply realize a condition of proper combustion in a combustion part serving as a heat source to evaporate water forming a raw material of reformed gas, in a fuel reforming device. SOLUTION: A hydrogen flow detecting means 27 is provided in a piping to collect exhaust gas from the fuel electrode of a fuel cell stack 1 in the combustion part 23, and a supply quantity of fuel and air supplied to the combustion part 23 is adjusted, in consideration of the detected hydrogen flow. The hydrogen flow detecting means 27 is to find a sound velocity and a flow velocity of the exhaust gas from the propagation velocity of a ultrasonic when the propagating direction is identical to the direction of the exhaust gas flowing downward and when it is reverse, by using the fact that hydrogen has a remarkably high sound speed in the exhaust gas and by disposing a pair of ultrasonic transducers capable of receiving the ultrasonic mutually transmitted in the direction of the exhaust gas flowing down, in the piping, and also to find the flow of the exhaust gas from the sound velocity and to find hydrogen concentration from the sound velocity.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【発明の属する技術分野】本発明は燃料電池自動車等の
燃料電池システムに付設される燃料改質装置に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel reformer attached to a fuel cell system such as a fuel cell automobile.

【0002】[0002]

【従来の技術】燃料改質装置は燃料電池システムに付設
されるもので、燃料としてメタノール等の原燃料を改質
して水素を主成分とする改質ガスを生成し、これを燃料
電池スタックに供給する。燃料改質装置には、改質ガス
の原料となる水を蒸発する熱源として、蒸発用燃料を燃
焼する燃焼部が設けられている。この蒸発用燃料の一部
として、燃料電池スタックからの排出ガスを回収して加
えるものがあり、燃料電池スタックで未使用の水素を再
利用している。
2. Description of the Related Art A fuel reformer is attached to a fuel cell system and reforms a raw fuel such as methanol as a fuel to produce a reformed gas containing hydrogen as a main component. Supply to. The fuel reforming device is provided with a combustion unit that burns evaporation fuel as a heat source that evaporates water that is a raw material of reformed gas. As part of this fuel for evaporation, there is one that recovers and adds exhaust gas from the fuel cell stack, and reuses unused hydrogen in the fuel cell stack.

【0003】ところで、燃焼部において適正な燃焼を実
現するには、燃焼部に供給する蒸発用燃料および空気の
流量を適正に調整することが必要になる。そこで、内燃
機関の制御等で実施されている空燃比制御を応用するこ
とが考えられる。すなわち燃焼部からの排出ガス中の酸
素濃度を検出して、供給する空気流量にフィードバック
制御をするのである。
By the way, in order to achieve proper combustion in the combustion section, it is necessary to properly adjust the flow rates of the vaporizing fuel and the air supplied to the combustion section. Therefore, it is conceivable to apply the air-fuel ratio control that is implemented in the control of the internal combustion engine or the like. That is, the oxygen concentration in the exhaust gas from the combustion unit is detected, and feedback control is performed on the flow rate of the supplied air.

【0004】[0004]

【発明が解決しようとする課題】しかしながら、燃焼部
から排出される排出ガス中の酸素濃度に基づいて空燃比
制御を行っても、蒸発用燃料に、燃料電池スタックから
の排出ガスが加わる影響で、必ずしも適正な燃焼を実現
することはできない。
However, even if the air-fuel ratio control is performed based on the oxygen concentration in the exhaust gas discharged from the combustion section, the effect of adding the exhaust gas from the fuel cell stack to the evaporative fuel is However, it is not always possible to achieve proper combustion.

【0005】本発明は前記実情に鑑みなされたもので、
燃焼部において適正な燃焼状態を実現することのできる
燃料改質装置を提供することを目的とする。
The present invention has been made in view of the above circumstances,
An object of the present invention is to provide a fuel reformer capable of achieving an appropriate combustion state in the combustion section.

【0006】[0006]

【課題を解決するための手段】請求項1記載の発明で
は、水素を主成分とし燃料電池スタックに供給されて燃
料ガスとなる改質ガスの原料を蒸発する熱源として、蒸
発用燃料を燃焼する燃焼部が設けられ、蒸発用燃料の一
部として、前記改質ガスを含む燃料電池スタックからの
排出ガスを回収して再利用する燃料改質装置において、
前記燃料電池スタックから燃焼部に回収される水素の流
量を検出する水素流量検出手段と、水素流量検出手段に
より検出された水素の流量に基づいて前記燃焼部に供給
する蒸発用燃料および空気の流量を調整する調整手段と
を具備し、前記水素流量検出手段を、燃料電池スタック
から燃焼部へ排出ガスを回収する回収用の配管内に設け
られて、排出ガスの流下方向に対する超音波の伝搬方向
が異なる2つの状態で超音波の送受信が可能な超音波ト
ランスデューサと、前記2つの状態のそれぞれの状態に
おける超音波の伝搬速度に基づいて、排出ガス中の音速
と配管内の排出ガスの流速とを演算し、音速から水素濃
度に換算するとともに、流速から排出ガスの流量に換算
する演算手段とを具備する構成とする。
According to a first aspect of the present invention, a fuel for evaporation is burned as a heat source for evaporating a raw material of a reformed gas which contains hydrogen as a main component and is supplied to a fuel cell stack and becomes a fuel gas. In a fuel reformer in which a combustion unit is provided and which collects and reuses exhaust gas from the fuel cell stack containing the reformed gas as a part of the evaporated fuel,
Hydrogen flow rate detection means for detecting the flow rate of hydrogen recovered from the fuel cell stack to the combustion section, and flow rates of evaporation fuel and air to be supplied to the combustion section based on the flow rate of hydrogen detected by the hydrogen flow rate detection means. Adjusting means for adjusting the hydrogen flow rate detecting means, the hydrogen flow rate detecting means is provided in a recovery pipe for recovering the exhaust gas from the fuel cell stack to the combustion section, and the ultrasonic wave propagation direction with respect to the downward direction of the exhaust gas. The ultrasonic transducer capable of transmitting and receiving ultrasonic waves in two different states, and the sound velocity in the exhaust gas and the flow velocity of the exhaust gas in the pipe based on the propagation velocity of the ultrasonic wave in each of the two states. Is calculated and the sound velocity is converted into the hydrogen concentration, and the flow velocity is converted into the flow rate of the exhaust gas.

【0007】排出ガスの流量と水素濃度とから水素流量
が知られるから、燃料電池スタックから燃焼部に回収さ
れる水素の流量が変動しても、これに追随して蒸発用燃
料流量および空気流量が加減され、適正な燃焼状態が得
られる。
Since the hydrogen flow rate is known from the exhaust gas flow rate and the hydrogen concentration, even if the flow rate of hydrogen recovered from the fuel cell stack to the combustion section fluctuates, it follows the evaporation fuel flow rate and the air flow rate. Is adjusted to obtain a proper combustion state.

【0008】水素は音速が他の物質に比してきわだって
速く、水素を含む流体中では、水素濃度に応じて音速が
大きく変化する。したがって、燃料電池スタックからの
排出ガス中の水素濃度を高精度に検出することができ
る。しかも、水素の流量を検出する手段が大規模化せ
ず、車両に搭載する燃料電池システム等に好適に適用す
ることができる。
The sound velocity of hydrogen is remarkably faster than that of other substances, and in a fluid containing hydrogen, the sound velocity greatly changes according to the hydrogen concentration. Therefore, the hydrogen concentration in the exhaust gas from the fuel cell stack can be detected with high accuracy. Moreover, the means for detecting the flow rate of hydrogen does not become large in scale, and can be suitably applied to a fuel cell system mounted on a vehicle.

【0009】請求項2記載の発明では、請求項1の発明
の構成において、前記超音波トランスデューサを、前記
配管内の排出ガスの流下方向に対する非直交方向に対向
する1対の超音波トランスデューサにより構成するとと
もに、1対の超音波トランスデューサを一方が送信のと
きに他方が受信となるように送受信を交互に切り替える
切り替え手段を具備せしめ、切り替え手段による送受信
の切り替えで前記2つの状態を切り替えるようにする。
According to a second aspect of the present invention, in the configuration of the first aspect of the invention, the ultrasonic transducer is composed of a pair of ultrasonic transducers facing each other in a direction non-orthogonal to the downflow direction of the exhaust gas in the pipe. In addition, a pair of ultrasonic transducers is provided with switching means for alternately switching transmission and reception so that when one is transmitting, the other is receiving, and the two states are switched by switching between transmission and reception by the switching means. .

【0010】超音波トランスデューサの送受信を切り替
えると、超音波の伝搬方向に対して排出ガスの流下方向
が逆方向となるから、1対の超音波トランスデューサを
設けるだけで排出ガスの流下方向に対して超音波の伝搬
方向が異なる前記2つの状態を実現することができる。
When the transmission / reception of the ultrasonic transducer is switched, the exhaust gas flow direction is opposite to the ultrasonic wave propagation direction. Therefore, by providing only one pair of ultrasonic transducers, the exhaust gas flow direction is reduced. It is possible to realize the two states in which the propagation directions of ultrasonic waves are different.

【0011】[0011]

【発明の実施の形態】図1に、本発明の燃料改質装置を
付設した燃料電池システムを示す。燃料電池システム
は、燃料電池自動車等に適用し得る。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a fuel cell system equipped with the fuel reforming apparatus of the present invention. The fuel cell system can be applied to a fuel cell vehicle or the like.

【0012】燃料電池スタック1は、燃料極に燃料改質
装置2から水素を主成分とする改質ガスが供給されると
ともに、空気極に図示しないポンプにより空気が供給さ
れるようになっており、公知の電池反応により発電す
る。燃料極および空気極出口からは排出ガスが排出され
る。燃料極側の排出ガス(以下、オフガスという)は後
述するように回収されて燃料改質装置2の燃焼部23で
再利用され、空気極側の排出ガスは例えば大気中に放出
される。
In the fuel cell stack 1, the fuel reforming gas containing hydrogen as a main component is supplied to the fuel electrode from the fuel reforming device 2, and the air is supplied to the air electrode by a pump (not shown). Power is generated by a known battery reaction. Exhaust gas is discharged from the outlets of the fuel electrode and the air electrode. The exhaust gas on the fuel electrode side (hereinafter referred to as off-gas) is collected and reused in the combustion section 23 of the fuel reformer 2 as described later, and the exhaust gas on the air electrode side is released to the atmosphere, for example.

【0013】燃料改質装置2は、改質部21、蒸発部2
2等からなる。改質部21には改質反応用の触媒が配設
されており、これに改質ガスの原料となる燃料、水の
他、空気が供給されるようになっている。改質反応によ
り得られた改質ガスは燃料電池スタック1に供給され
る。前記燃料には、メタノール、ガソリン、天然ガス等
が用いられ得る。
The fuel reformer 2 includes a reformer 21 and an evaporator 2.
It consists of 2 mag. The reforming section 21 is provided with a catalyst for reforming reaction, and is supplied with air as well as fuel and water which are raw materials of the reformed gas. The reformed gas obtained by the reforming reaction is supplied to the fuel cell stack 1. The fuel may be methanol, gasoline, natural gas or the like.

【0014】蒸発部22は、改質部21の前段に位置
し、改質ガスの原料として供給された水を加熱して水蒸
気にして改質部21に供給する。
The evaporating section 22 is located in front of the reforming section 21, and heats water supplied as a raw material of the reforming gas to form steam to supply it to the reforming section 21.

【0015】蒸発部22で水が吸熱する熱は、燃焼部2
3から与えられる。燃焼部23は水の蒸発用の燃料が燃
焼するバーナであり、燃料供給部24から蒸発用燃料が
供給されるとともに、空気供給部25から空気が供給さ
れる。燃料供給部24および空気供給部25はそれぞれ
ポンプにより構成されており、その駆動回路が出力する
ポンプの駆動電圧等の調整により燃料や空気の吐出量が
調整自在である。
The heat absorbed by water in the evaporating section 22 is transferred to the combustion section 2
Given from 3. The combustion unit 23 is a burner in which fuel for vaporizing water burns, and the fuel for vaporization is supplied from the fuel supply unit 24 and the air is supplied from the air supply unit 25. The fuel supply unit 24 and the air supply unit 25 are each constituted by a pump, and the discharge amount of fuel or air can be adjusted by adjusting the drive voltage of the pump output from the drive circuit thereof.

【0016】燃焼部23は燃料電池スタック1の燃料極
出口と配管で接続されており、燃料極からのオフガスが
蒸発用燃料の一部として加えられる。配管の途中には水
素流量検出手段である水素流量計27が設けてあり、配
管を流れる水素の流量を検出するようになっている。
The combustion section 23 is connected to the fuel electrode outlet of the fuel cell stack 1 by a pipe, and the off gas from the fuel electrode is added as a part of the fuel for evaporation. A hydrogen flow meter 27, which is a hydrogen flow rate detecting means, is provided in the middle of the piping to detect the flow rate of hydrogen flowing through the piping.

【0017】水素流量計27は、図2に示すように、燃
料電池スタック1と燃焼部23とを接続する配管3の途
中部分を構成する音速計測部31内に、オフガスの流下
方向に1対の超音波トランスデューサ4a,4bが送受
信面41a,41bが互いに対向するように配置してあ
る。また、音速計測部31内には温度センサ5が設けら
れ、流通するオフガスの温度を検出する。
As shown in FIG. 2, the hydrogen flow meter 27 includes a pair of hydrogen gas flow meters 27 in the sonic velocity measuring section 31 which constitutes an intermediate portion of the pipe 3 connecting the fuel cell stack 1 and the combustion section 23 in the downward direction of the off gas. The ultrasonic transducers 4a and 4b are arranged so that the transmitting / receiving surfaces 41a and 41b face each other. In addition, the temperature sensor 5 is provided in the sonic velocity measuring unit 31 to detect the temperature of the off gas flowing therethrough.

【0018】超音波トランスデューサ4a,4bは、例
えばセラミック振動子により構成され、超音波を送信す
るスピーカとしての機能と超音波を受信するマイクロフ
ォンとしての機能とを備えたものが用いられる。
The ultrasonic transducers 4a and 4b are composed of, for example, ceramic vibrators, and those having a function as a speaker for transmitting ultrasonic waves and a function as a microphone for receiving ultrasonic waves are used.

【0019】超音波トランスデューサ4a,4bは、切
り替え手段6を構成する切り替えスイッチ61a,61
bおよび信号処理回路62により制御される。切り替え
スイッチ61aは超音波トランスデューサ4aを信号処
理回路62内の入力回路と出力回路のいずれかと接続す
るスイッチであり、切り替えスイッチ61bは超音波ト
ランスデューサ4bを信号処理回路62内の入力回路と
出力回路のいずれかと接続するスイッチである。切り替
えスイッチ61a,61bは同期して作動し、信号処理
回路62から駆動信号が入力した一方の超音波トランス
デューサ4a(4b)から発せられた超音波バースト
が、他方の超音波トランスデューサ4b(4a)で受信
され、出力信号が信号処理回路62に入力するようにな
っている。すなわち、両超音波トランスデューサ4a,
4bが、交互に立場を替えながらマイクロフォンとして
の期間とスピーカとしての期間とを繰り返すことにな
る。
The ultrasonic transducers 4a, 4b are composed of changeover switches 61a, 61 constituting the changeover means 6.
b and the signal processing circuit 62. The changeover switch 61a is a switch that connects the ultrasonic transducer 4a to either the input circuit or the output circuit in the signal processing circuit 62, and the changeover switch 61b connects the ultrasonic transducer 4b to the input circuit and the output circuit in the signal processing circuit 62. It is a switch that connects with either. The changeover switches 61a and 61b operate in synchronization with each other, and an ultrasonic burst emitted from one ultrasonic transducer 4a (4b) to which a drive signal is input from the signal processing circuit 62 is transmitted to the other ultrasonic transducer 4b (4a). The received signal is input to the signal processing circuit 62. That is, both ultrasonic transducers 4a,
4b repeats the period as a microphone and the period as a speaker while alternately changing positions.

【0020】信号処理回路62では、超音波の送信時点
および受信時点を検出することにより、上流側の超音波
トランスデューサ4aが超音波を送信したときの超音波
トランスデューサ4a,4b間の超音波の伝搬時間、下
流側の超音波トランスデューサ4bが超音波を送信した
ときの伝搬時間をそれぞれ計測する。
The signal processing circuit 62 detects the transmission time point and the reception time point of the ultrasonic wave to propagate the ultrasonic wave between the ultrasonic transducers 4a and 4b when the ultrasonic wave transducer 4a on the upstream side transmits the ultrasonic wave. The time and the propagation time when the ultrasonic transducer 4b on the downstream side transmits ultrasonic waves are measured.

【0021】信号処理回路62の回路構成としては、超
音波の送信時点および受信時点を検出するものの他、送
信信号を鋸波のような周期信号により周波数変調して送
信信号と受信信号とのビート信号により両信号の位相差
を求めるもの等、種々の公知の回路構成を用い得る。
The circuit configuration of the signal processing circuit 62 is to detect the transmission time point and the reception time point of the ultrasonic wave, and also frequency-modulates the transmission signal with a periodic signal such as a sawtooth wave to beat the transmission signal and the reception signal. Various known circuit configurations can be used, such as one that obtains the phase difference between both signals by a signal.

【0022】信号処理回路62からの伝搬時間検出信号
および温度センサ5からの温度検出信号は、演算手段で
ある情報処理回路7にて演算処理に供されて、水素の流
量を得るようになっている。
The propagation time detection signal from the signal processing circuit 62 and the temperature detection signal from the temperature sensor 5 are subjected to arithmetic processing in the information processing circuit 7 which is an arithmetic means to obtain the flow rate of hydrogen. There is.

【0023】情報処理回路7で実行される演算処理につ
いて説明する。上流側の超音波トランスデューサ4aが
超音波Saを送信したときと、下流側の超音波トランス
デューサ4bが超音波Sbを送信したときとでは、オフ
ガスの流下方向に対する超音波の伝搬方向が異なるか
ら、音波の伝搬方向がオフガスの流下方向と同じになる
前者の場合の超音波の伝搬時間の方が短くなる。
The arithmetic processing executed by the information processing circuit 7 will be described. Since the upstream ultrasonic transducer 4a transmits the ultrasonic wave Sa and the downstream ultrasonic transducer 4b transmits the ultrasonic wave Sb, the propagation direction of the ultrasonic wave with respect to the downward direction of the offgas is different. In the former case, the propagation time of the ultrasonic wave becomes the same as the down-flow direction of the offgas, and the propagation time of the ultrasonic wave becomes shorter.

【0024】ここで、両超音波トランスデューサ4a,
4bの対向間隔(以下、音速計測長さLという)を伝搬
時間で除した伝搬速度を、超音波の伝搬方向とオフガス
の流下方向とが同じになる状態のときをVf 、超音波の
伝搬方向とオフガスの流下方向とが逆になる状態のとき
をVb 、オフガスの流速をVg 、オフガス中の音速をV
s とすれば、次式(1)(2)が成り立つ。 Vg =(Vf +Vb )/2・・・(1) Vs =(Vf −Vb )/2・・・(2)
Here, both ultrasonic transducers 4a,
The propagation velocity obtained by dividing the facing distance of 4b (hereinafter referred to as the sound velocity measurement length L) by the propagation time is Vf when the propagation direction of the ultrasonic waves is the same as the downflow direction of the offgas, and the propagation direction of the ultrasonic waves. Is Vb when the flow direction of the off gas is opposite to the flow direction of the off gas, Vg is the flow velocity of the off gas, and V is the sound velocity in the off gas.
If s, the following equations (1) and (2) are established. Vg = (Vf + Vb) / 2 ... (1) Vs = (Vf-Vb) / 2 ... (2)

【0025】ここで、Vs はオフガスの組成に依存す
る。オフガスの組成は、水、二酸化炭素、窒素および水
素で略規定し得る。Vs は一般的に式(3)により表さ
れる。式中、Rは気体定数である。Mi は分子量、Cpi
は定圧モル比熱、Cviは定容モル比熱である。Di は各
成分ガスの濃度である。Tはオフガスの温度である。
Here, Vs depends on the composition of the off gas. The composition of offgas may be roughly defined by water, carbon dioxide, nitrogen and hydrogen. Vs is generally represented by the equation (3). In the formula, R is a gas constant. Mi is the molecular weight, Cpi
Is a constant pressure molar specific heat, and Cvi is a constant volume molar specific heat. Di is the concentration of each component gas. T is the temperature of the offgas.

【0026】[0026]

【数1】 [Equation 1]

【0027】音速Vs は式(3)より知られるようにオ
フガスの成分ガスに依存するが、燃料電池スタック1に
おける電池反応等により水、二酸化炭素、窒素は殆ど変
化せず、水素だけが燃料電池スタック1の発電状態等に
応じて大きく変化する。そして、水素の音速は水、二酸
化炭素、窒素等に比してきわめて速いので、オフガス中
の音速の変化は、略水素濃度の変化だけが反映されたも
のとなる。そこで、情報処理回路7に、水素濃度Dと音
速Vs および温度センサ5の検出温度Tとの対応関係を
記憶しておき、水素濃度Dを得る。この対応関係は式
(3)に基づくものであり、マップや演算式等、形式は
限定されない。また、対応関係を求めるに際しては、オ
フガス中の水、二酸化炭素、窒素等の濃度を予め計測若
しくは算出しておくことを要するのは勿論である。
As is known from the equation (3), the sound velocity Vs depends on the component gas of the off gas, but water, carbon dioxide, and nitrogen hardly change due to the cell reaction in the fuel cell stack 1, and only hydrogen is contained in the fuel cell. It greatly changes according to the power generation state of the stack 1. Since the speed of sound of hydrogen is extremely faster than that of water, carbon dioxide, nitrogen, etc., the change in the speed of sound in off-gas reflects only the change in hydrogen concentration. Therefore, the information processing circuit 7 stores the correspondence relationship between the hydrogen concentration D, the sound velocity Vs, and the temperature T detected by the temperature sensor 5 to obtain the hydrogen concentration D. This correspondence relationship is based on the equation (3), and the format such as a map or an arithmetic expression is not limited. Further, it is needless to say that it is necessary to measure or calculate the concentrations of water, carbon dioxide, nitrogen, etc. in the offgas in advance when obtaining the correspondence.

【0028】また、流速Vg を得て、これをオフガスの
流量Qに換算する。換算は予め流速Vg とオフガス流量
Qとの対応関係を実験等により求めておき、これを情報
処理回路7に記憶しておけばよい。なお、簡単には流速
Vg に音速計測部31の管径を乗じてオフガス流量Qと
し得るのは勿論である。
Further, the flow velocity Vg is obtained and converted into the flow rate Q of off gas. For the conversion, the correspondence between the flow velocity Vg and the off-gas flow rate Q may be obtained in advance by experiments or the like and stored in the information processing circuit 7. Of course, the flow velocity Vg can be simply multiplied by the pipe diameter of the sonic velocity measuring unit 31 to obtain the offgas flow rate Q.

【0029】情報処理回路7では、最後に、水素濃度D
にオフガス流量Qを乗じて水素の流量を得る。
In the information processing circuit 7, finally, the hydrogen concentration D
Is multiplied by the off gas flow rate Q to obtain the flow rate of hydrogen.

【0030】なお、水素濃度Dは配管3の音速計測部3
1内に気圧を検出する圧力センサを設けて標準状態の値
に換算し、さらに高精度化するのもよい。
The hydrogen concentration D is measured by the sound velocity measuring unit 3 of the pipe 3.
It is also possible to provide a pressure sensor for detecting the atmospheric pressure in 1 to convert it into a value in the standard state and further improve the accuracy.

【0031】水素の流量のデータは調整手段である燃焼
制御部26に熱量指令値とともに入力せしめてある。燃
焼制御部26は、燃料電池システムの制御系の一部であ
り、燃料供給部24、空気供給部25の制御を司る。燃
焼制御部26は、燃料供給部24用の駆動回路には燃料
供給量指令値を出力する。このとき燃料供給量指令値
は、水の蒸発用の燃料の一部をなすオフガスに含まれる
水素流量が考慮され、燃料供給部25からの燃料とオフ
ガス中の水素とで熱量指令値が要求する燃料の総量を賄
うように設定されている。また、燃焼制御部26は、空
気供給部25用の駆動回路には空気供給量指令値を出力
する。空気供給量指令値は、水素流量と燃料供給量指令
値とに目標とする空燃比を乗じて得られる空気量の値が
与えられる。
The data of the flow rate of hydrogen is input to the combustion control unit 26 which is the adjusting means together with the heat quantity command value. The combustion control unit 26 is a part of the control system of the fuel cell system, and controls the fuel supply unit 24 and the air supply unit 25. The combustion control unit 26 outputs a fuel supply amount command value to the drive circuit for the fuel supply unit 24. At this time, the fuel supply amount command value takes into consideration the flow rate of hydrogen contained in the off gas that forms a part of the fuel for water evaporation, and the heat amount command value is demanded by the fuel from the fuel supply unit 25 and the hydrogen in the off gas. It is set to cover the total amount of fuel. Further, the combustion control unit 26 outputs an air supply amount command value to the drive circuit for the air supply unit 25. As the air supply amount command value, a value of the air amount obtained by multiplying the hydrogen flow rate and the fuel supply amount command value by the target air-fuel ratio is given.

【0032】燃料供給部24、空気供給部25では、前
記燃料供給量指令値、空気供給量指令値に基づいて燃料
供給量、空気供給量が調整される。
In the fuel supply unit 24 and the air supply unit 25, the fuel supply amount and the air supply amount are adjusted based on the fuel supply amount command value and the air supply amount command value.

【0033】これにより、燃焼部23において、空燃比
が適正な値に調整されるとともに、熱量指令値に対応し
た熱量を発生する、適正な燃焼状態を実現することがで
きる。
As a result, in the combustion section 23, the air-fuel ratio can be adjusted to a proper value, and a proper combustion state can be realized in which the heat quantity corresponding to the heat quantity command value is generated.

【0034】しかも、オフガス中の音速が水素濃度に応
じて大きく変化することを利用して、超音波トランスデ
ューサ4a,4bのような簡単な構成で水素流量の高精
度な計測を実現しているので、低コストであり、実施が
容易である。
Moreover, the fact that the speed of sound in the offgas greatly changes according to the hydrogen concentration is utilized to realize highly accurate measurement of the hydrogen flow rate with a simple structure such as the ultrasonic transducers 4a and 4b. Low cost and easy to implement.

【0035】なお、本実施形態では、超音波トランスデ
ューサ4a,4bを、配管3内のオフガスの流下方向に
配置しているが、超音波トランスデューサ4a,4bが
オフガスの流下方向に対する非直交方向に対向しておれ
ばよく、例えば、超音波トランスデューサ4a,4b
を、流下方向に対してやや傾げて配置してもよい。この
場合も、上流側の超音波トランスデューサ4aが超音波
を送信したときと下流側の超音波トランスデューサ4b
が超音波を送信したときとで、オフガスの流下方向に対
する超音波の伝搬方向が異なるようにすることができる
からである。
In the present embodiment, the ultrasonic transducers 4a and 4b are arranged in the downflow direction of the off gas in the pipe 3. However, the ultrasonic transducers 4a and 4b are opposed to each other in a non-orthogonal direction with respect to the downflow direction of the off gas. The ultrasonic transducers 4a and 4b, for example.
May be disposed with a slight inclination with respect to the flow direction. Also in this case, when the upstream ultrasonic transducer 4a transmits ultrasonic waves and when the downstream ultrasonic transducer 4b transmits ultrasonic waves.
This is because the propagation direction of the ultrasonic wave with respect to the downward direction of the offgas can be different from that when the ultrasonic wave is transmitted.

【0036】また、切り替えスイッチ61a,61bお
よび信号処理回路62により、超音波トランスデューサ
4a,4bの一方が送信のときに他方が受信となるよう
に送受信を交互に切り替えるようにすることで、1対の
超音波トランスデューサ4a,4bのみで、オフガスの
流下方向に対して超音波の伝搬方向が異なる2つの状態
が現出するようにしているが、必ずしもこれに限定され
るものではない。例えば、送受信面を互いに対向せしめ
た1対の超音波トランスデューサが2組からなる構成と
し、流下方向に対する超音波の伝搬方向が一方の組と他
方の組とで異なるように超音波トランスデューサを配置
する。
By using the changeover switches 61a and 61b and the signal processing circuit 62, transmission and reception are alternately switched so that when one of the ultrasonic transducers 4a and 4b is transmitting, the other is receiving. Although only the ultrasonic transducers 4a and 4b of FIG. 2 have two states in which the propagation directions of the ultrasonic waves are different with respect to the downward direction of the offgas, the present invention is not necessarily limited to this. For example, a pair of ultrasonic transducers whose transmitting and receiving surfaces are opposed to each other is composed of two groups, and the ultrasonic transducers are arranged so that the propagation direction of ultrasonic waves with respect to the downflow direction is different between one group and the other group. .

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の燃料改質装置を付設した燃料電池シス
テムの構成図である。
FIG. 1 is a configuration diagram of a fuel cell system provided with a fuel reformer of the present invention.

【図2】前記燃料改質装置の水素流量計の構成図であ
る。
FIG. 2 is a configuration diagram of a hydrogen flow meter of the fuel reformer.

【符号の説明】[Explanation of symbols]

1 燃料電池スタック 2 燃料改質装置 21 改質部 22 蒸発部 23 燃焼部 24 燃料供給部 25 空気供給部 26 燃焼制御部(調整手段) 27 水素流量計(水素流量検出手段) 3 配管 4a,4b 超音波トランスデューサ 5 温度センサ 6 切り替え手段 61a,61b 切り替えスイッチ 62 信号処理回路 7 情報処理回路(演算手段) 1 Fuel cell stack 2 Fuel reformer 21 reforming section 22 Evaporator 23 Combustion part 24 Fuel supply section 25 Air supply unit 26 Combustion control unit (adjusting means) 27 Hydrogen flow meter (hydrogen flow rate detection means) 3 piping 4a, 4b ultrasonic transducer 5 Temperature sensor 6 switching means 61a, 61b changeover switch 62 signal processing circuit 7 Information processing circuit (calculation means)

───────────────────────────────────────────────────── フロントページの続き (72)発明者 杉野 正芳 愛知県西尾市下羽角町岩谷14番地 株式会 社日本自動車部品総合研究所内 (72)発明者 荻野 温 愛知県豊田市トヨタ町1番地 トヨタ自動 車株式会社内 Fターム(参考) 2F035 DA14 DA19 DA22 4G040 EA02 EA03 EA06 EA07 EB03 EB42 EB43 EB44 5H027 AA02 BA09 BA19 KK26 MM03   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masayoshi Sugino             14 Iwatani Shimohakaku-cho, Nishio-shi, Aichi Stock Association             Company Japan Auto Parts Research Institute (72) Inventor Atsushi Ogino             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. F term (reference) 2F035 DA14 DA19 DA22                 4G040 EA02 EA03 EA06 EA07 EB03                       EB42 EB43 EB44                 5H027 AA02 BA09 BA19 KK26 MM03

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】 水素を主成分とし燃料電池スタックに供
給されて燃料ガスとなる改質ガスの原料を蒸発する熱源
として、蒸発用燃料を燃焼する燃焼部が設けられ、蒸発
用燃料の一部として、前記改質ガスを含む燃料電池スタ
ックからの排出ガスを回収して再利用する燃料改質装置
において、 前記燃料電池スタックから燃焼部に回収される水素の流
量を検出する水素流量検出手段と、 水素流量検出手段により検出された水素の流量に基づい
て前記燃焼部に供給する蒸発用燃料および空気の流量を
調整する調整手段とを具備し、 前記水素流量検出手段を、燃料電池スタックから燃焼部
へ排出ガスを回収する回収用の配管内に設けられて、排
出ガスの流下方向に対する超音波の伝搬方向が異なる2
つの状態で超音波の送受信が可能な超音波トランスデュ
ーサと、 前記2つの状態のそれぞれの状態における超音波の伝搬
速度に基づいて、排出ガス中の音速と配管内の排出ガス
の流速とを演算し、音速から水素濃度に換算するととも
に、流速から排出ガスの流量に換算する演算手段とを具
備する構成としたことを特徴とする燃料改質装置。
1. A combustion unit for burning evaporative fuel is provided as a heat source for evaporating a raw material of a reformed gas which contains hydrogen as a main component and is supplied to a fuel cell stack and becomes a fuel gas, and a part of the evaporative fuel is provided. As a fuel reformer that collects and reuses exhaust gas from the fuel cell stack including the reformed gas, a hydrogen flow rate detection unit that detects a flow rate of hydrogen recovered from the fuel cell stack to a combustion section, And adjusting means for adjusting the flow rates of the evaporative fuel and the air supplied to the combustion unit based on the flow rate of hydrogen detected by the hydrogen flow rate detecting means, wherein the hydrogen flow rate detecting means is burned from the fuel cell stack. Is provided in a recovery pipe for recovering the exhaust gas to the section, and the propagation direction of ultrasonic waves is different from the flow-down direction of the exhaust gas.
An ultrasonic transducer capable of transmitting and receiving ultrasonic waves in two states, and the sound velocity in the exhaust gas and the flow velocity of the exhaust gas in the pipe are calculated based on the ultrasonic wave propagation velocity in each of the two states. A fuel reforming apparatus comprising: a calculation unit that converts the sound velocity into hydrogen concentration and the flow velocity into exhaust gas flow rate.
【請求項2】 請求項1記載の燃料改質装置において、
前記超音波トランスデューサを、前記配管内の排出ガス
の流下方向に対する非直交方向に対向する1対の超音波
トランスデューサにより構成するとともに、 1対の超音波トランスデューサを一方が送信のときに他
方が受信となるように送受信を交互に切り替える切り替
え手段を具備せしめ、 切り替え手段による送受信の切り替えで前記2つの状態
を切り替えるようにした燃料改質装置。
2. The fuel reformer according to claim 1, wherein
The ultrasonic transducer is composed of a pair of ultrasonic transducers facing each other in a non-orthogonal direction with respect to a flow-down direction of exhaust gas in the pipe, and one pair of ultrasonic transducers is transmitted when one is transmitting and the other is receiving. The fuel reformer is equipped with a switching means for alternately switching between transmission and reception so that the two states can be switched by switching between transmission and reception by the switching means.
JP2001270046A 2001-09-06 2001-09-06 Fuel reforming device Pending JP2003077518A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2001270046A JP2003077518A (en) 2001-09-06 2001-09-06 Fuel reforming device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2001270046A JP2003077518A (en) 2001-09-06 2001-09-06 Fuel reforming device

Publications (1)

Publication Number Publication Date
JP2003077518A true JP2003077518A (en) 2003-03-14

Family

ID=19095752

Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

Country Link
JP (1) JP2003077518A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120107705A1 (en) * 2010-10-27 2012-05-03 Gm Global Technology Operations, Inc. Anode gas composition utilizing h2 injection pressure wave propagation rates
CN102780017A (en) * 2011-05-10 2012-11-14 通用汽车环球科技运作有限责任公司 Acoustic speed of sound measurement using bandpass filtering of automotive pressure sensors
WO2013141083A1 (en) 2012-03-19 2013-09-26 Jx日鉱日石エネルギー株式会社 Method for determining composition of gas fuel, device for determining composition of gas fuel, fuel supply system, and fuel cell system
CN116053528A (en) * 2023-01-28 2023-05-02 江苏重塑能源科技有限公司 Anode loop hydrogen concentration measuring method and system

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JPH01251561A (en) * 1988-03-30 1989-10-06 Mitsubishi Electric Corp Control of combustor for fuel cell reformer
JPH06213877A (en) * 1992-11-12 1994-08-05 Devilbiss Health Care Inc Gas concentration and/or flow rate sensor
JP2000338093A (en) * 1999-05-25 2000-12-08 Osaka Gas Co Ltd Method and apparatus for measuring nitrogen gas content in methane gas
JP2001126854A (en) * 1999-10-29 2001-05-11 Hitachi Hometec Ltd Induction heating cooking device
JP2002306603A (en) * 2001-04-16 2002-10-22 Teijin Ltd Oxygen concentrator

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01251561A (en) * 1988-03-30 1989-10-06 Mitsubishi Electric Corp Control of combustor for fuel cell reformer
JPH06213877A (en) * 1992-11-12 1994-08-05 Devilbiss Health Care Inc Gas concentration and/or flow rate sensor
JP2000338093A (en) * 1999-05-25 2000-12-08 Osaka Gas Co Ltd Method and apparatus for measuring nitrogen gas content in methane gas
JP2001126854A (en) * 1999-10-29 2001-05-11 Hitachi Hometec Ltd Induction heating cooking device
JP2002306603A (en) * 2001-04-16 2002-10-22 Teijin Ltd Oxygen concentrator

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120107705A1 (en) * 2010-10-27 2012-05-03 Gm Global Technology Operations, Inc. Anode gas composition utilizing h2 injection pressure wave propagation rates
CN102539524A (en) * 2010-10-27 2012-07-04 通用汽车环球科技运作有限责任公司 Anode gas composition utilizing h2 injection pressure wave propagation rates
US8603688B2 (en) * 2010-10-27 2013-12-10 GM Global Technology Operations LLC Anode gas composition utilizing H2 injection pressure wave propagation rates
CN102539524B (en) * 2010-10-27 2015-02-11 通用汽车环球科技运作有限责任公司 Anode gas composition utilizing h2 injection pressure wave propagation rates
CN102780017A (en) * 2011-05-10 2012-11-14 通用汽车环球科技运作有限责任公司 Acoustic speed of sound measurement using bandpass filtering of automotive pressure sensors
CN102780017B (en) * 2011-05-10 2015-02-25 通用汽车环球科技运作有限责任公司 Acoustic speed of sound measurement using bandpass filtering of automotive pressure sensors
WO2013141083A1 (en) 2012-03-19 2013-09-26 Jx日鉱日石エネルギー株式会社 Method for determining composition of gas fuel, device for determining composition of gas fuel, fuel supply system, and fuel cell system
CN116053528A (en) * 2023-01-28 2023-05-02 江苏重塑能源科技有限公司 Anode loop hydrogen concentration measuring method and system

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