JP2001021466A - Apparatus for detecting concentration of hydrogen - Google Patents
Apparatus for detecting concentration of hydrogenInfo
- Publication number
- JP2001021466A JP2001021466A JP11195738A JP19573899A JP2001021466A JP 2001021466 A JP2001021466 A JP 2001021466A JP 11195738 A JP11195738 A JP 11195738A JP 19573899 A JP19573899 A JP 19573899A JP 2001021466 A JP2001021466 A JP 2001021466A
- Authority
- JP
- Japan
- Prior art keywords
- hydrogen
- hydrogen concentration
- gas
- concentration
- permeable membrane
- 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
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】水素はクリーンなエネルギーとし
て多くの産業で活用されているが、とくに燃料電池の研
究開発の進歩と共に自動車の動力源として期待されてお
り、水素濃度の測定は自動車産業その他の広い範囲に利
用される。[Industrial applications] Hydrogen is used in many industries as clean energy, but it is expected to be used as a power source for automobiles, especially as fuel cell research and development progresses. Used for a wide range of
【０００２】[0002]
【従来の技術】水素濃度を測定する装置にはガスクロマ
トグラフィを始め各種あるが、検出器は熱特性の相違を
利用するのが一般的で多くは例えば共存する他の可燃ガ
スの影響を受けるなど、干渉を排除できなかった。さら
に従来の測定装置は応答速度が５秒以上を要することか
ら、自動車用の燃料電池に適用するには不十分な特性で
あった。2. Description of the Related Art There are various types of devices for measuring hydrogen concentration, such as gas chromatography, but detectors generally use differences in thermal characteristics, and in many cases, for example, they are affected by other coexisting combustible gases. , Interference could not be ruled out. Further, since the conventional measuring device requires a response speed of 5 seconds or more, it has insufficient characteristics to be applied to a fuel cell for an automobile.
【０００３】[0003]
【発明が解決しようとする課題】燃料電池などに用いる
水素には共存するガスとしてＣＯ，ＣＨ4、メタノール
など可燃ガスが含まれることが多い。こうした共存ガス
の影響を排除して水素濃度を正確に測定することが課題
である。また自動車の動力源として利用する場合は測定
の応答速度が２秒以内であることが必要でこれも重要な
課題である。[0006] Hydrogen used in fuel cells and the like often contains combustible gases such as CO, CH 4 , and methanol as coexisting gases. It is an issue to accurately measure the hydrogen concentration while eliminating the influence of such a coexisting gas. When used as a power source of an automobile, the response speed of measurement must be within 2 seconds, which is also an important issue.
【０００４】[0004]
【課題を解決するための手段】水素を含む混合ガスから
水素を分離する手段として膜技術を利用するが、とくに
透過速度が大きくできるＰｄ合金などで薄膜の厚さを極
限に小さくした分離膜を用いる手段を講じた。こうした
薄膜では差圧に対する強度が十分でないために、補強用
にステンレスの細線などで作られたメッシユを用いると
共に膜の透過性能に大きな影響をもつ温度を精密に制御
するようにした。また透過膜通過後の水素を一定流量の
空気または窒素など水素を含まないガスと均一に混合し
て水素検出器に接触させるようにした。Means for Solving the Problems Membrane technology is used as a means for separating hydrogen from a mixed gas containing hydrogen. In particular, a separation membrane having a minimum thickness of a thin film made of a Pd alloy or the like which can increase the permeation speed is used. The means used were taken. Since such a thin film does not have sufficient strength against a differential pressure, a mesh made of a thin stainless steel wire or the like is used for reinforcement, and a temperature which has a great influence on the permeation performance of the membrane is precisely controlled. Further, hydrogen after passing through the permeable membrane was uniformly mixed with a constant flow rate of air or a gas containing no hydrogen such as nitrogen, and was brought into contact with the hydrogen detector.
【０００５】[0005]
【発明実施の形態】本発明の実施例を示す図１の測定装
置の構成説明図および水素透過膜の機能を解説する図
２、図３の解説図によって説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment of the present invention will be described with reference to FIG. 1 showing the configuration of a measuring apparatus and FIG. 2 and FIG. 3 showing the function of a hydrogen permeable membrane.
【０００６】図１において５０は水素濃度測定装置であ
る。水素濃度測定装置５０は測定部２０を有する。測定
部２０はサンプリング室６と水素濃度検出室２１とが隣
り合って設けられており、サンプリング室６と水素濃度
検出室２１との間に水素透過膜１０が配設されて両室
６、２１を遮断している。In FIG. 1, reference numeral 50 denotes a hydrogen concentration measuring device. The hydrogen concentration measuring device 50 has a measuring unit 20. The measuring section 20 is provided with a sampling chamber 6 and a hydrogen concentration detection chamber 21 adjacent to each other, and the hydrogen permeable membrane 10 is disposed between the sampling chamber 6 and the hydrogen concentration detection chamber 21 so that the two chambers 6 and 21 are arranged. Is shut off.
【０００７】水素濃度検出室２１内にはガス混合部２２
と濃度検出部２４が設けられている。ガス混合部２２に
おいては一定流量の空気や窒素ガス等の水素を含まない
ガスからなる混合ガス３０を水素透過膜１０を透過した
水素と乱流攪拌により混合する。濃度検出部２４には水
素濃度検出器２３が配設されている。水素透過膜１０は
水素だけを通過する膜体で、Ｐｄ合金等で構成される。
水素の透過速度を大きくするためには水素透過膜１０を
極限に小さくすることが有効であるが、膜厚を小さくす
ると強度が小さくなるため、水素透過膜１０に差圧に耐
える強度を確保するために水素透過膜１０の低圧側にス
テンレスの網線などの適当な材質の金属メッシュ１１を
配置して水素透過膜１０が差圧に耐え得る構造とする。A gas mixing section 22 is provided in the hydrogen concentration detecting chamber 21.
And a density detector 24 are provided. In the gas mixing section 22, a mixed gas 30 made of a gas containing no hydrogen such as air or nitrogen gas at a constant flow rate is mixed with hydrogen permeated through the hydrogen permeable membrane 10 by turbulent stirring. The concentration detector 24 is provided with a hydrogen concentration detector 23. The hydrogen permeable film 10 is a film that passes only hydrogen, and is made of a Pd alloy or the like.
In order to increase the permeation rate of hydrogen, it is effective to make the hydrogen permeable membrane 10 as small as possible. However, when the film thickness is reduced, the strength is reduced, so that the hydrogen permeable membrane 10 has enough strength to withstand a differential pressure. For this purpose, a metal mesh 11 made of a suitable material such as a stainless steel mesh wire is arranged on the low pressure side of the hydrogen permeable membrane 10 so that the hydrogen permeable membrane 10 can withstand a differential pressure.
【０００８】このような構造の水素濃度検出測定装置５
０において、被測定試料ガス１はサンプリング管２から
フィルタ３を経てポンプ４で加圧されて温度制御された
測定部２０に導かれる。測定部２０では電熱管５によっ
て一定温度に制御された被測定試料ガス１は定圧サンプ
リング室６に入り、定圧制御弁８により圧力計７に示さ
れる一定圧力に保たれるが、水素透過膜１０によって一
部の水素が水素濃度検出室２１に透過される。定圧制御
弁８を経由した被測定試料ガス１は被測定試料ガス流出
管９を経由して適当に流出される。[0008] The hydrogen concentration detecting and measuring device 5 having such a structure.
At 0, the sample gas 1 to be measured is guided from the sampling tube 2 through the filter 3 to the measuring unit 20 which is pressurized by the pump 4 and temperature-controlled. In the measuring section 20, the sample gas 1 to be measured controlled at a constant temperature by the electric heating tube 5 enters the constant pressure sampling chamber 6, and is maintained at a constant pressure indicated by the pressure gauge 7 by the constant pressure control valve 8. As a result, part of the hydrogen is transmitted to the hydrogen concentration detection chamber 21. The sample gas 1 to be measured via the constant pressure control valve 8 is appropriately discharged through the sample gas outflow pipe 9 to be measured.
【０００９】水素濃度検出室２１には外部からフィルタ
２７、脱湿器２８および流量安定用に配置したキャピラ
リィ２９を経由して空気または窒素など水素を含まない
ガスが導入される。このとき水素透過膜１０を透過した
水素と外部から導入した空気などのガスを均一に混合さ
せるために、ガスを単数または複数の噴出孔３１から適
切な方向に噴出させて渦流を発生させ、水素透過膜１０
の水素濃度検出室２１側に補強用に配置されたステンレ
スのメッシュ１１の直後の部分に渦による攪拌混合を効
果的に利用するガス混合部２２を形成する。A hydrogen-free gas such as air or nitrogen is introduced into the hydrogen concentration detection chamber 21 from the outside via a filter 27, a dehumidifier 28, and a capillary 29 arranged for stabilizing the flow rate. At this time, in order to uniformly mix hydrogen such as air introduced from the outside with hydrogen that has passed through the hydrogen permeable membrane 10, the gas is ejected from one or a plurality of ejection holes 31 in an appropriate direction to generate a vortex, Permeable membrane 10
A gas mixing section 22 is formed in a portion immediately after the stainless steel mesh 11 arranged for reinforcement on the side of the hydrogen concentration detection chamber 21 to effectively use the stirring and mixing by the vortex.
【００１０】混合ガス３０は水素濃度検出器２３の設置
された濃度検出部２４においても適切な渦流を保っよう
にガスの排出孔２６にも適切な方向を設定しておく。混
合ガス３０の水素濃度が水素濃度検出器２３で検出測定
され、被測定試料ガス１の中の水素濃度に対応できる数
値として演算器１５で計算され出力される。このとき水
素透過膜１０を透過する水素の流量や外部から導入され
る空気などの流量が関係する。さらに水素透過膜の前後
の圧力とくに水素分圧の関係や温度は極めて重要であ
る。水素濃度検出室２１の圧力は圧力計２５で監視され
るが、混合ガス３０は流量を可変流量計３３で適当に設
定されて、減圧ポンプ３４で吸引され排出管３５から排
出される。An appropriate direction of the mixed gas 30 is also set in the gas discharge hole 26 so as to maintain an appropriate vortex even in the concentration detector 24 in which the hydrogen concentration detector 23 is installed. The hydrogen concentration of the mixed gas 30 is detected and measured by the hydrogen concentration detector 23, and is calculated and output by the calculator 15 as a numerical value corresponding to the hydrogen concentration in the sample gas 1 to be measured. At this time, the flow rate of hydrogen permeating the hydrogen permeable membrane 10 and the flow rate of air or the like introduced from the outside are related. Further, the relationship between the pressure before and after the hydrogen permeable membrane, especially the partial pressure of hydrogen, and the temperature are extremely important. The pressure in the hydrogen concentration detection chamber 21 is monitored by a pressure gauge 25, and the flow rate of the mixed gas 30 is appropriately set by a variable flow meter 33, sucked by a pressure reducing pump 34 and discharged from a discharge pipe 35.
【００１１】水素透過膜１０には種々あるが、一般的に
多孔質膜の場合は分子の平均自由行程λと孔径ｒとの関
係がｒ／λ≦１でクヌーセンの法則に従うとして、透過
する水素の流量ｑは、ｑ＝Ｐｃ（Ｐ1−Ｐ2）／ｔ で表
せる。ここにＰｃは透過係数で、Ｐ1、Ｐ2は膜の前後の
圧力、ｔは細孔の長さである。また、Ｐｄ合金のように
水素をイオン化して透過する場合は、分圧の平方根の差
に比例する形になり、ｑ＝ｑ0｛（Ｐ1）1/2−（Ｐ2）
1/2｝／ｔ で表せるが、ｑ0には活性化エネルギーや絶
対温度などの影響を含んでいる。図２に示す多孔質膜の
場合は分子の大きさが問題でまた差圧／膜厚が重要であ
るが、図３のＰｄ合金の場合は特に膜厚が重要であると
いえる。水素透過に関する選択性が優れているＰｄ合金
では膜厚を薄くすることが必要で、こうした関係から補
強用にステンレスのメッシュを利用する。There are various types of hydrogen permeable membranes. In general, in the case of a porous membrane, it is assumed that the relationship between the mean free path λ of a molecule and the pore diameter r is in accordance with Knudsen's law when r / λ ≦ 1 and that hydrogen passing therethrough is Can be expressed by q = Pc (P 1 −P 2 ) / t. Here, Pc is a permeability coefficient, P 1 and P 2 are pressures before and after the membrane, and t is a length of the pore. Further, when hydrogen is ionized and permeated as in the case of a Pd alloy, it is in a form proportional to the difference between the square roots of the partial pressures, and q = q 0 ｛(P 1 ) 1/2 − (P 2 )
Although it can be expressed by 1/2 ｝ / t, q 0 includes effects such as activation energy and absolute temperature. In the case of the porous film shown in FIG. 2, the size of the molecule is a problem, and the differential pressure / film thickness is important. However, in the case of the Pd alloy shown in FIG. 3, the film thickness is particularly important. In the case of a Pd alloy having excellent selectivity with respect to hydrogen permeation, it is necessary to reduce the film thickness. For this reason, a stainless steel mesh is used for reinforcement.
【００１２】[0012]
【発明の効果】本発明の水素濃度測定装置によれば、被
測定試料ガスに水素以外の多くの干渉成分が含まれてい
る条件おいても、水素だけを水素濃度検出室に導いて測
定に適当な濃度のガスとして水素濃度を正確に測定する
ことができる。例えばＰｄ水素透過膜を用いて５０％程
度の水素を含む被測定試料ガスについて加圧して水素透
過膜から２ｍＬ／ｍｉｎ程度の水素透過量を得たと仮定
して、２Ｌ／ｍｉｎ程度の流量の外部導入空気と混合し
て混合ガス３０を形成して、１０００ｐｐｍの濃度の水
素を水素濃度検出器２３で検出していたとする。被測定
試料ガスの水素濃度が４５％に減少した場合には水素透
過膜からの水素透過量は（０．４５）1/2／（０．５
０）1/2の割合減少して２ｍＬ／ｍｉｎから１．９１８
ｍＬ／ｍｉｎになる。混合ガス３０の水素濃度は１００
０ｐｐｍから９５９ｐｐｍに変化する。こうした濃度変
化から容易に被測定試料ガスの水素濃度を測定すること
ができる。本発明の水素濃度測定装置では水素透過膜の
透過速度を速くするために膜の厚さを極端に薄くするこ
とが可能であり、水素濃度検出器の応答速度の速いもの
を利用することと相俟って速い応答の測定が可能とな
る。According to the hydrogen concentration measuring apparatus of the present invention, even under the condition that the sample gas to be measured contains many interference components other than hydrogen, only hydrogen is led to the hydrogen concentration detecting chamber for measurement. The hydrogen concentration can be accurately measured as a gas having an appropriate concentration. For example, assuming that a sample gas to be measured containing about 50% of hydrogen is pressurized using a Pd hydrogen permeable membrane and a hydrogen permeation rate of about 2 mL / min is obtained from the hydrogen permeable membrane, an external flow rate of about 2 L / min is obtained. It is assumed that the mixed gas 30 is formed by mixing with the introduced air, and hydrogen having a concentration of 1000 ppm is detected by the hydrogen concentration detector 23. When the hydrogen concentration of the sample gas to be measured is reduced to 45%, the amount of hydrogen permeation from the hydrogen permeable membrane is (0.45) 1/2 /(0.5
0) The ratio of 1/2 was reduced to 2 mL / min to 1.918.
mL / min. The hydrogen concentration of the mixed gas 30 is 100
It changes from 0 ppm to 959 ppm. From such a concentration change, the hydrogen concentration of the sample gas to be measured can be easily measured. In the hydrogen concentration measuring apparatus of the present invention, the thickness of the hydrogen permeable membrane can be extremely reduced in order to increase the permeation rate of the hydrogen permeable membrane. In addition, a quick response can be measured.
【００１３】[0013]
【図１】本発明の水素濃度測定装置の構成例を示す説明
図FIG. 1 is an explanatory diagram showing a configuration example of a hydrogen concentration measuring device of the present invention.
【図２】多孔質膜による気体分子の透過機能を示す解説
図FIG. 2 is a diagram illustrating a gas molecule permeation function of a porous membrane.
【図３】Ｐｄ合金膜による水素透過の機能を示す解説図FIG. 3 is an explanatory view showing a function of hydrogen permeation by a Pd alloy film.
１ 被測定試料ガス ２ サンプリング管（１２ｌ／ｍｉｎ，２００ｍｌ／
ｓ） ３ フィルタ ４ ポンプ（５ｋｇｆ／ｃｍ2） ５ 伝熱管（８５℃） ６ 定圧サンプリング室 ７ 圧力計 ８ 定圧制御弁 ９ 被測定ガス流出管 １０ 水素透過膜 １１ メッシュ １３ 多孔膜 １５ 演算器 １６ 温度コントローラ ２０ 定温度測定部（８５℃） ２１ 水素濃度検出室 ２２ ガス混合部 ２３ 水素濃度検出器 ２４ 濃度検出部 ２５ 圧力計 ２６ 排出孔 ２７ フィルタ ２８ 脱湿器 ２９ キャピラリィ ３０ 混合ガス ３１ 噴出孔 ３３ 可変流量計 ３４ 減圧ポンプ ３５ 排出管 ５０ 水素濃度測定装置1 Sample gas to be measured 2 Sampling tube (12 l / min, 200 ml /
s) 3 filter 4 pump (5 kgf / cm 2 ) 5 heat transfer tube (85 ° C.) 6 constant pressure sampling chamber 7 pressure gauge 8 constant pressure control valve 9 measured gas outflow tube 10 hydrogen permeable membrane 11 mesh 13 porous membrane 15 arithmetic unit 16 temperature Controller 20 Constant temperature measuring unit (85 ° C.) 21 Hydrogen concentration detecting chamber 22 Gas mixing unit 23 Hydrogen concentration detector 24 Concentration detecting unit 25 Pressure gauge 26 Discharge hole 27 Filter 28 Dehumidifier 29 Capillary 30 Mixed gas 31 Spout hole 33 Variable Flow meter 34 Decompression pump 35 Discharge pipe 50 Hydrogen concentration measuring device
Claims (4)
リング室と一定圧力に設定した水素濃度検出室との間に
水素だけを通過させる水素透過膜を配置して、被測定試
料ガスの中の水素のみを水素濃度検出室側に通過させて
これに一定流量の空気または窒素など水素を含まないガ
スを混合して、水素濃度検出器で被測定試料ガスの水素
濃度を測定する水素濃度測定装置1. A hydrogen permeable membrane that allows only hydrogen to pass between a sampling chamber for keeping a sample gas to be measured at a constant pressure and a hydrogen concentration detection chamber set to a constant pressure, is provided. A hydrogen concentration measurement device that passes only hydrogen to the hydrogen concentration detection chamber side, mixes it with a constant flow rate of air or a gas that does not contain hydrogen such as nitrogen, and measures the hydrogen concentration of the sample gas to be measured with a hydrogen concentration detector.
素透過膜に作用する差圧に耐える強度を確保するために
低圧側に金属メッシユを配置して差圧に対応できる水素
透過膜の構造とした水素濃度測定装置2. A structure of a hydrogen permeable membrane capable of coping with a differential pressure by arranging a metal mesh on a low pressure side in order to secure a strength withstanding a differential pressure acting on the hydrogen permeable membrane in the hydrogen concentration measuring device according to claim 1. Hydrogen concentration measuring device
おいて水素だけを通過させる水素透過膜の温度を一定に
保つために、温度制御の機能を有する水素透過膜を保持
する構造をもつ水素濃度測定装置3. A hydrogen concentration having a structure for holding a hydrogen permeable membrane having a temperature control function in order to keep the temperature of a hydrogen permeable membrane through which only hydrogen passes in the hydrogen concentration measuring apparatus according to claim 1 or 2. measuring device
置において水素濃度検出室にガス混合部と濃度検出部を
設け、ガス混合部において一定流量の水素を含まないガ
スと水素透過膜を透過した水素とを乱流攪拌により混合
して、濃度検出部において水素濃度検出器で検出する水
素濃度測定装置4. A hydrogen concentration measuring apparatus according to claim 1, further comprising a gas mixing section and a concentration detecting section provided in the hydrogen concentration detecting chamber, wherein the gas mixing section includes a gas containing no hydrogen at a constant flow rate and the hydrogen permeable membrane. Hydrogen concentration measuring device that mixes the permeated hydrogen with turbulent agitation and detects it with a hydrogen concentration detector at the concentration detector
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11195738A JP2001021466A (en) | 1999-07-09 | 1999-07-09 | Apparatus for detecting concentration of hydrogen |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11195738A JP2001021466A (en) | 1999-07-09 | 1999-07-09 | Apparatus for detecting concentration of hydrogen |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2001021466A true JP2001021466A (en) | 2001-01-26 |
Family
ID=16346155
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11195738A Pending JP2001021466A (en) | 1999-07-09 | 1999-07-09 | Apparatus for detecting concentration of hydrogen |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2001021466A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023238573A1 (en) * | 2022-06-07 | 2023-12-14 | 株式会社村田製作所 | Gas concentration measuring device |
-
1999
- 1999-07-09 JP JP11195738A patent/JP2001021466A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023238573A1 (en) * | 2022-06-07 | 2023-12-14 | 株式会社村田製作所 | Gas concentration measuring device |
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