JP2616935B2 - Combustion flame detector for gaseous fuel - Google Patents
Combustion flame detector for gaseous fuelInfo
- Publication number
- JP2616935B2 JP2616935B2 JP62251127A JP25112787A JP2616935B2 JP 2616935 B2 JP2616935 B2 JP 2616935B2 JP 62251127 A JP62251127 A JP 62251127A JP 25112787 A JP25112787 A JP 25112787A JP 2616935 B2 JP2616935 B2 JP 2616935B2
- Authority
- JP
- Japan
- Prior art keywords
- flame
- combustion
- light
- spectrum
- receiving element
- 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.)
- Expired - Fee Related
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- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
- Control Of Combustion (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、燃焼火炎の有無を検出する気体燃料の燃焼
火炎検出装置に関するものである。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a combustion flame of gaseous fuel for detecting the presence or absence of a combustion flame.
〔従来の技術〕 従来の火炎検出器は、紫外線域の光量の多少、可視光
および近赤外波長域の光のゆらぎの強弱、または燃焼火
炎の形成の有無による燃焼域の導電性の変化などを検出
して、火炎が形成されているか否かを判断していた。本
発明は燃焼火炎の光量の多少、または光のゆらぎを検出
して行なう火炎検出装置に関するものであるので、従来
例としてはその範疇に属するものを挙げる。[Prior art] Conventional flame detectors use a small amount of light in the ultraviolet region, fluctuations in light in the visible and near-infrared wavelength regions, or changes in conductivity in the combustion region due to the presence or absence of a combustion flame. Was detected to determine whether or not a flame was formed. The present invention relates to a flame detection device that detects the amount of light of a combustion flame or the fluctuation of the light, so that a conventional example belongs to that category.
第３図は、従来の火炎検出装置の概略図である。この
火炎検出装置は、光ファイバ14、15、受光素子16および
リレーユニット17から主に構成されている。光ファイバ
14は火炉壁13に設けられた火炎覗き窓18に取付けられ
る。燃料19および燃焼用空気20が火炉11内に供給され、
火炎12が形成される。この火炎12の発光スペクトルは火
炎覗き窓18に取付けられた光ファイバ14によって受光さ
れる。受光された発光スペクトルは、延長コードの光フ
ァイバ15によって、受光素子16へと運ばれ、電気信号に
変換される。電気信号となった火炎スペクトルは、リレ
ーユニット17において、火炎が形成されていないときの
電気信号と比較され、火炎の有無が判定される。21は冷
却用空気、22はバーナである。FIG. 3 is a schematic diagram of a conventional flame detection device. This flame detection device mainly includes optical fibers 14, 15, a light receiving element 16, and a relay unit 17. Optical fiber
14 is attached to a flame viewing window 18 provided on the furnace wall 13. Fuel 19 and combustion air 20 are supplied into the furnace 11,
A flame 12 is formed. The emission spectrum of the flame 12 is received by the optical fiber 14 attached to the flame viewing window 18. The received emission spectrum is carried to the light receiving element 16 by the optical fiber 15 of the extension cord, and is converted into an electric signal. The flame spectrum that has become the electric signal is compared with the electric signal when no flame is formed in the relay unit 17 to determine the presence or absence of the flame. 21 is a cooling air, 22 is a burner.
従来の火炎検出装置では、紫外領域（波長0.36μｍ以
下）の発光スペクトルの強度、または可視・近赤外領域
（波長0.4〜1.0μｍ）の発光スペクトル強度を検出して
いる。一般に、火炎検出装置は、火炎発光スペクトル以
外に、赤熱された炉壁が発光するスペクトルも検出す
る。このため、火炎の発光スペクトルは炉壁の発光スペ
クトルに比較して充分大きなスペクトル強度を有してい
る必要がある。A conventional flame detection device detects the intensity of the emission spectrum in the ultraviolet region (wavelength 0.36 μm or less) or the emission spectrum intensity in the visible / near infrared region (wavelength 0.4 to 1.0 μm). Generally, a flame detection device detects a spectrum emitted from a glowed furnace wall in addition to a flame emission spectrum. For this reason, the emission spectrum of the flame needs to have a sufficiently large spectrum intensity as compared with the emission spectrum of the furnace wall.
第５図に、各種受光素子とその検出波長域を示す。一
般に、紫外領域のスペクトル検出にはCs2Te（セシウム
・テルル）、可視・近赤外領域のスペクトル検出にはSi
（シリコン）系の受光素子が用いられている。FIG. 5 shows various light receiving elements and their detection wavelength ranges. In general, Cs 2 Te (cesium tellurium) is used for ultraviolet spectrum detection, and Si is used for visible / near infrared spectrum detection.
A (silicon) -based light receiving element is used.
ボイラなどの燃焼装置においては、数年前より、燃焼
排ガス中の窒素酸化物を減少させるため、燃料として窒
素含有量の少ない液化天然ガスのようなガス燃料を使用
するとともに、燃焼法としては、燃料の燃焼時に発生す
る窒素酸化物を低減するため、燃焼用空気の供給量を燃
料の完全燃焼に必要な空気量、いわゆる理論空気量より
も低く抑えた１次燃焼を行なわせ、次いで未燃分につい
ては、さらに空気を追加して２次燃焼を行なわせるとい
う脱硝燃焼法が採用されている。Combustion devices such as boilers use gas fuels such as liquefied natural gas with a low nitrogen content as fuels to reduce nitrogen oxides in combustion exhaust gas from several years ago. In order to reduce nitrogen oxides generated during combustion of fuel, primary combustion is performed in which the supply amount of combustion air is kept lower than the amount of air required for complete combustion of fuel, that is, the so-called theoretical air amount, and then unburned. As for the amount, a denitrification combustion method in which air is further added to perform secondary combustion is adopted.
しかしながら、ガス燃料を使用する場合には、紫外線
域の光量の強弱や、可視光および近赤外域の光のゆらぎ
の強弱によって火炎を検出する従来の火炎検出装置は使
用できないことがわかった。However, when using gaseous fuel, it has been found that a conventional flame detection device that detects a flame based on the intensity of light in the ultraviolet region or the intensity of fluctuations in visible light and near-infrared light cannot be used.
この原因について調べたところ、ガス燃料を空気不足
状態で燃焼させる脱硝燃焼方法においては、火炎検出装
置が火炎を測定対象としている部分であるバーナ近傍の
火炎が、空気不足状態となり、この火炎からの紫外線
光、可視光、近赤外光の受光量が微少で、火炎の点火、
消火に際しての受光素子の検出値の変化が極めて小さい
ためであることがわかった。After examining the cause, in the denitrification combustion method of burning gas fuel in a state of insufficient air, the flame near the burner, which is the part where the flame is measured by the flame detection device, becomes in an air shortage state, and The amount of ultraviolet light, visible light, and near-infrared light received is very small.
It was found that the change in the detection value of the light receiving element during fire extinguishing was extremely small.
第４図は、メタンガスを主成分とする液化天然ガスお
よび軽油についての発光スペクトルの測定結果を示す図
である。燃焼に必要な理論空気量の1.2倍の空気量を供
給して行なう一般燃焼（空燃比1.2）および脱硝燃焼
（空燃比0.8）について、それぞれにおける火炎発光ス
ペクトルの分布を測定した。図において、天然ガスの脱
硝燃焼時（No.4）の火炎のスペクトル強度は、メタンガ
スの存在を示す紫外線領域の波長0.117〜0.127μｍにお
いてピークを示すが、発光強度は低い。また、可視光領
域では発光スペクトルがほとんど認められず、近赤外、
赤外光領域においては1.38μｍおよび1.87μｍ近傍をピ
ークとする発光スペクトルが生じている。FIG. 4 is a diagram showing measurement results of emission spectra of liquefied natural gas containing methane gas as a main component and light oil. The distribution of the flame emission spectrum was measured for general combustion (air-fuel ratio 1.2) and denitrification combustion (air-fuel ratio 0.8) performed by supplying an air amount 1.2 times the theoretical air amount required for combustion. In the figure, the spectrum intensity of the flame at the time of denitration combustion of natural gas (No. 4) shows a peak at a wavelength of 0.117 to 0.127 μm in the ultraviolet region indicating the presence of methane gas, but the emission intensity is low. In the visible light region, almost no emission spectrum was observed,
In the infrared light region, emission spectra having peaks near 1.38 μm and 1.87 μm are generated.
以上のように、天然ガス燃料を燃焼させる場合、特に
天然ガスの脱硝燃焼の場合には、紫外光域、可視光域お
よび1.3μｍ以下の近赤外域で行なう火炎からの光量の
多少または光のゆらぎの強弱による従来の測定装置は採
用できないことがわかった。As described above, when burning natural gas fuel, particularly in the case of denitrification combustion of natural gas, the amount of light or the amount of light from a flame performed in the ultraviolet light range, visible light range, and near infrared range of 1.3 μm or less is reduced. It turned out that the conventional measuring device cannot be adopted due to the strength of fluctuation.
本発明の目的は、上記従来技術の問題点を解決し、液
化天然ガス等の気体燃料の脱硝燃焼時の火炎を確実に検
出することができる気体燃料の燃焼火炎検出装置を提供
することにある。SUMMARY OF THE INVENTION It is an object of the present invention to provide a gas fuel combustion flame detection device that can solve the above-mentioned problems of the prior art and can reliably detect a flame during denitration combustion of a gas fuel such as liquefied natural gas. .
本発明は、火炎からの発光スペクトルを受光して伝送
する光ファイバ装置と、光ファイバ装置からの光信号を
受けて電気信号に変換する受光素子と、受光素子からの
電気信号を受信して設定値信号と比較し火炎の有無を判
定するリレーユニットとを有する燃焼装置における気体
燃料の燃焼火炎検出装置において、前記受光素子の前面
に光ファイバ装置から伝送された光スペクトルを受け、
1.38μｍ近傍の光を選択的に透過させる光学フィルタを
設けたことを特徴とする。The present invention provides an optical fiber device that receives and transmits an emission spectrum from a flame, a light receiving element that receives an optical signal from the optical fiber device and converts it into an electric signal, and receives and sets an electric signal from the light receiving element. In a combustion flame detection device for gaseous fuel in a combustion device having a relay unit that determines the presence or absence of a flame by comparing with a value signal, receiving an optical spectrum transmitted from an optical fiber device in front of the light receiving element,
An optical filter for selectively transmitting light near 1.38 μm is provided.
第１図は、本発明の一実施例における火炎検出装置の
断面図である。この火炎検出装置は、光ファイバ14、1
5、受光素子16、光学フィルタ25およびリレーユニット1
7から主に構成されている。光ファイバ14は従来と同様
に火炉壁13に設けられた火炎覗き窓18に取付けられる。
光学フィルタ25には、1.38μｍ近傍の光を選択的に透過
するコーティングを施したガラスが用いられる。FIG. 1 is a sectional view of a flame detecting device according to an embodiment of the present invention. This flame detection device uses optical fibers 14, 1
5, light receiving element 16, optical filter 25 and relay unit 1
It is mainly composed of seven. The optical fiber 14 is attached to a flame viewing window 18 provided on the furnace wall 13 as in the conventional case.
The optical filter 25 is made of glass having a coating that selectively transmits light near 1.38 μm.
燃料19および燃焼用空気20が火炉11内に供給され、火
炎12が形成されている。この火炎12の発光スペクトルは
火炎覗き窓18に取付けられた光ファイバ14によって受光
される。受光された発光スペクトルは、延長コード用光
ファイバ15を通って、受光素子16の前面に設置された光
学フィルタ25を透過した後、受光素子16に受光され電気
信号に変換される。電気信号となった火炎スペクトルは
リレーユニット17において、火炎が形成されていないと
きの電気信号と比較され、火炎の有無が判定される。Fuel 19 and combustion air 20 are supplied into the furnace 11, and a flame 12 is formed. The emission spectrum of the flame 12 is received by the optical fiber 14 attached to the flame viewing window 18. The received emission spectrum passes through an optical fiber 15 for an extension cord, passes through an optical filter 25 installed in front of the light receiving element 16, is received by the light receiving element 16, and is converted into an electric signal. The flame spectrum that has become an electric signal is compared in the relay unit 17 with an electric signal when no flame is formed, and the presence or absence of a flame is determined.
なお、本発明になる一実施例は、光学フィルタ25に1.
38μｍ近傍の光を選択的に透過する光学フィルタを用い
て示したが、ガス燃料の燃焼によって生じる、高温のH2
Oは、1.38μｍ以外に1.87μｍ、2.7μｍ、3.2μｍおよ
び6.3μｍに発光スペクトルを有しており、これら波長
の光学フィルタ25を用いることもできる。Note that one embodiment according to the present invention provides the optical filter 25 with 1.
Although shown using an optical filter that selectively transmits light near 38 μm, high-temperature H 2
O has an emission spectrum at 1.87 μm, 2.7 μm, 3.2 μm, and 6.3 μm other than 1.38 μm, and the optical filter 25 having these wavelengths can also be used.
受光素子16には、PbS（鉛イオウ）、PbSe（鉛セレ
ン）系素子が適し、これらの検出波長域は前記第５図に
示すとおりである。本発明はメタンガスに限らず、燃焼
によって水蒸気（H2O）を生じるガス燃料の燃焼ガスの
火炎の検出に適用可能である。As the light receiving element 16, a PbS (lead sulfur) or PbSe (lead selenium) element is suitable, and their detection wavelength ranges are as shown in FIG. The present invention is not limited to methane gas, and is applicable to detection of a flame of a combustion gas of gaseous fuel that generates steam (H 2 O) by combustion.
本発明によれば、液化天然ガスの脱硝燃焼における火
炎スペクトルを、強度の強い特定の波長域で検出するこ
とから、外乱となる赤熱した炉壁の発光スペクトルより
も大きくなり、したがって、確実に火炎の有無を判定す
ることが可能となる。According to the present invention, since the flame spectrum in the denitrification combustion of liquefied natural gas is detected in a specific wavelength region where the intensity is strong, the flame spectrum becomes larger than the emission spectrum of the red-heated furnace wall, which is a disturbance, and therefore, the flame is surely Can be determined.
仮に、光学フィルタをを用いない場合、受光素子にPb
Sを用いると、1.0〜3.0μｍの範囲を受光することか
ら、この波長域のスペクトル強度の合計は、赤熱した炉
壁からのスペクトルのほうが、火炎からのスペクトルよ
りも大きくなり、火炎の検出が不能となる問題が生じ
る。If an optical filter is not used, Pb
When S is used, light in the range of 1.0 to 3.0 μm is received, so the sum of the spectral intensities in this wavelength range is larger in the spectrum from the glowing furnace wall than in the flame, and the flame detection The problem that becomes impossible arises.
しかし、本発明では、光学フィルタを用い、H2Oの発
光スペクトルを有する波長域のスペクトルのみを検出す
るため、火炎の検出が不能となる問題は生じない。However, in the present invention, since the optical filter is used to detect only the spectrum in the wavelength range having the emission spectrum of H 2 O, there is no problem that the flame cannot be detected.
第２図は、本発明の他の実施例における火炎検出装置
の断面図である。この実施例は、光学フィルタ25を着脱
させる光学フィルタ移動装置30を設けたものである。つ
まり、バーナへの着火時は、火炎からのスペクトルを光
学フィルタ25を透過させず直接受光素子16で受光するよ
うにし、定常運転時（脱硝燃焼）には火炎からのスペク
トルを光学フィルタ25に透過させ、その後受光素子16で
受光するようにした。FIG. 2 is a sectional view of a flame detecting device according to another embodiment of the present invention. In this embodiment, an optical filter moving device 30 for attaching and detaching the optical filter 25 is provided. That is, when the burner is ignited, the spectrum from the flame is directly received by the light receiving element 16 without passing through the optical filter 25, and the spectrum from the flame is transmitted to the optical filter 25 during steady operation (denitration combustion). Then, the light was received by the light receiving element 16.
これは、バーナ着火時は、安定した火炎を形成するた
め、空燃比を高くし、一般燃焼を行なっている。したが
って、着火時の火炎スペクトルは第４図の２点銷線（N
o.3）で示すように発光スペクトルが増大した状態であ
り、光フィルタを通さずに火炎のスペクトルを受光した
ほうが、精度よく火炎の有無を判定できる。This is because when the burner is ignited, the air-fuel ratio is increased and general combustion is performed in order to form a stable flame. Therefore, the flame spectrum at the time of ignition is represented by the two-point sales line (N
As shown in o.3), the emission spectrum is in an increased state, and the presence / absence of a flame can be determined with higher accuracy by receiving the flame spectrum without passing through an optical filter.
本発明によれば、従来装置では検出できなかったガス
燃料の燃焼バーナにおける火炎の有無を正確に検出する
ことが可能となる。According to the present invention, it is possible to accurately detect the presence or absence of a flame in a gas fuel combustion burner, which cannot be detected by the conventional device.
第１図は、本発明の一実施例における気体燃料の燃焼火
炎検出装置の断面図、第２図は、本発明の他の実施例の
気体燃料の燃焼火炎検出装置の断面図、第３図は、従来
の火炎検出装置の断面図、第４図は、各種燃料の燃焼時
の火炎発光スペクトル強度を示す図、第５図は、各種受
光素子の検出波長域を示す図である。 11……火炉、12……火炎、13……火炉壁、14、15……光
ファイバ装置、16……受光素子、17……リレーユニッ
ト、19……気体燃料、20……燃焼用空気、21……冷却用
空気、22……バーナ、25……光学フィルタ。FIG. 1 is a sectional view of a gas fuel combustion flame detecting device according to one embodiment of the present invention, FIG. 2 is a sectional view of a gas fuel burning flame detecting device of another embodiment of the present invention, FIG. Is a sectional view of a conventional flame detecting device, FIG. 4 is a diagram showing a flame emission spectrum intensity when various fuels are burned, and FIG. 5 is a diagram showing a detection wavelength range of various light receiving elements. 11 ... furnace, 12 ... flame, 13 ... furnace wall, 14, 15 ... fiber optic device, 16 ... light receiving element, 17 ... relay unit, 19 ... gaseous fuel, 20 ... combustion air, 21: Cooling air, 22: Burner, 25: Optical filter.
Claims (1)
する光ファイバ装置と、光ファイバ装置からの光信号を
受けて電気信号に変換する受光素子と、受光素子からの
電気信号を受信して設定値信号と比較し火炎の有無を判
定するリレーユニットとを有する燃焼装置における気体
燃料の燃焼火炎検出装置において、前記受光素子の前面
に光ファイバ装置から伝送された光スペクトルを受け、
1.38μｍ近傍の光を選択的に透過させる光学フィルタを
設けたことを特徴とする気体燃料の燃焼火炎検出装置。An optical fiber device for receiving and transmitting an emission spectrum from a flame, a light receiving element for receiving an optical signal from the optical fiber device and converting it into an electric signal, and an electric signal for receiving an electric signal from the light receiving element. In a combustion flame detection device for gaseous fuel in a combustion device having a relay unit that determines the presence or absence of a flame by comparing with a set value signal, receiving a light spectrum transmitted from an optical fiber device in front of the light receiving element,
An apparatus for detecting a combustion flame of gaseous fuel, comprising an optical filter for selectively transmitting light near 1.38 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62251127A JP2616935B2 (en) | 1987-10-05 | 1987-10-05 | Combustion flame detector for gaseous fuel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62251127A JP2616935B2 (en) | 1987-10-05 | 1987-10-05 | Combustion flame detector for gaseous fuel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0192626A JPH0192626A (en) | 1989-04-11 |
| JP2616935B2 true JP2616935B2 (en) | 1997-06-04 |
Family
ID=17218073
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62251127A Expired - Fee Related JP2616935B2 (en) | 1987-10-05 | 1987-10-05 | Combustion flame detector for gaseous fuel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2616935B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4255420B2 (en) * | 2004-09-06 | 2009-04-15 | 能美防災株式会社 | Flame detector |
| JP4745863B2 (en) * | 2005-02-28 | 2011-08-10 | 株式会社四国総合研究所 | Flame visualization device |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59138931A (en) * | 1983-01-28 | 1984-08-09 | Matsushita Electric Works Ltd | Flame detector |
| JPS60185233U (en) * | 1984-05-18 | 1985-12-09 | 株式会社日立製作所 | combustion sensor |
-
1987
- 1987-10-05 JP JP62251127A patent/JP2616935B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0192626A (en) | 1989-04-11 |
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