JPH03136195A - Fire detection system - Google Patents
Fire detection systemInfo
- Publication number
- JPH03136195A JPH03136195A JP27365789A JP27365789A JPH03136195A JP H03136195 A JPH03136195 A JP H03136195A JP 27365789 A JP27365789 A JP 27365789A JP 27365789 A JP27365789 A JP 27365789A JP H03136195 A JPH03136195 A JP H03136195A
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- fire
- optical fiber
- fire detection
- detection system
- 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.)
- Granted
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 44
- 239000013307 optical fiber Substances 0.000 claims abstract description 46
- 238000004804 winding Methods 0.000 claims abstract description 43
- 238000012545 processing Methods 0.000 claims abstract description 12
- 238000001069 Raman spectroscopy Methods 0.000 claims description 11
- 238000009529 body temperature measurement Methods 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 238000002791 soaking Methods 0.000 claims description 4
- 230000003287 optical effect Effects 0.000 description 16
- 238000005259 measurement Methods 0.000 description 7
- 239000011295 pitch Substances 0.000 description 5
- 239000000872 buffer Substances 0.000 description 4
- 230000035945 sensitivity Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- 230000004043 responsiveness Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000004069 differentiation Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 229920006015 heat resistant resin Polymers 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012806 monitoring device Methods 0.000 description 1
- 230000001932 seasonal effect Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、光ファイバの温度感受性を利用した火災検知
システムに関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fire detection system that utilizes the temperature sensitivity of optical fibers.
（従来の技術）
化学プラント、トンネル、ビル等においては、火災の発
生を早期に検知する集中監視システムの開発が強く要請
されている。この集中監視システムにおいては、火災の
発生を短時間に正確に検知できること並びに火災の発生
位置を特定できることが必要である。これらの要求を満
たす火災検知方式として、光ファイバの温度感受性を利
用した検知システムが既知であり、例えば特開昭６３７
３４００号公報に開示されている。この既知の火災検知
装置では、火災検知すべき測定領域に光ファイバを配設
し、光ファイバの入射端がらパルス状レーザ光を投射し
、光ファイバで発生する後方散乱光を受光し、後方散乱
光の強度及び後方散乱光の到達時間から光ファイバの各
部位の温度及び位置を検出している。そして検出温度か
ら火災の発生を検知している。(Prior Art) In chemical plants, tunnels, buildings, etc., there is a strong demand for the development of a centralized monitoring system that can detect the occurrence of fire at an early stage. In this centralized monitoring system, it is necessary to be able to accurately detect the occurrence of a fire in a short time and to be able to specify the location of the fire occurrence. As a fire detection method that satisfies these requirements, a detection system that utilizes the temperature sensitivity of optical fiber is known;
It is disclosed in Japanese Patent No. 3400. In this known fire detection device, an optical fiber is arranged in the measurement area where fire is to be detected, a pulsed laser beam is projected from the input end of the optical fiber, and the backscattered light generated by the optical fiber is received. The temperature and position of each part of the optical fiber are detected from the intensity of the light and the arrival time of the backscattered light. The occurrence of a fire is detected from the detected temperature.
（発明が解決しようとする課題）
光ファイバの温度感受性を利用した火災検知方式は１本
の光ファイバを用いて監視すべき領域の複数の部位の温
度変化を検出でき並びに各部位の位置を特定できるため
、火災の発生を集中監視するモニタ装置として極めて有
意義なものである。(Problem to be solved by the invention) A fire detection method that utilizes the temperature sensitivity of optical fibers can detect temperature changes in multiple parts of the area to be monitored using a single optical fiber, and can identify the location of each part. Therefore, it is extremely useful as a monitoring device for centrally monitoring the occurrence of fire.
しかしながら、光ファイバを用いる温度検出システムは
距離分解能によって制約を受けるため、検出温度は単位
分解能距離当りの平均温度になってしまう。このため、
上述した既知の火災検知センサのように１本の光ファイ
バを測定区域内に単に配設したにすぎないシステムでは
位置的な検知精度が不充分であり、しかも温度変化量が
小さく昇温特性もゆるやかであるため、実際に火災検知
システムに適用するには種々の難点があるのが実情であ
る。すなわち、距離分解能が７．５ｍの温度計測システ
ムを用いる場合において、その光ファイバの微小長部分
例えば１ｍの部分が加熱されても、平均化された温度が
出力されるため検出開始瞬時には実際の温度よりも低い
温度が検出され、長時間経過しても検出温度が実際の温
度と一致しないのが実情である。従って既知の火災検知
システムにそのまま適用したのでは、火災の発生を検知
するまでに時間がかかりすぎる不具合があった。However, since temperature detection systems using optical fibers are limited by distance resolution, the detected temperature is an average temperature per unit resolution distance. For this reason,
A system such as the above-mentioned known fire detection sensor, in which a single optical fiber is simply placed within the measurement area, has insufficient positional detection accuracy, and also has small temperature changes and temperature rise characteristics. The reality is that there are various difficulties in actually applying this method to fire detection systems because it is so lenient. In other words, when using a temperature measurement system with a distance resolution of 7.5 m, even if a very small part of the optical fiber, for example a 1 m long part, is heated, the averaged temperature will be output, so the actual temperature will not be the same at the moment detection starts. The reality is that the detected temperature does not match the actual temperature even after a long period of time. Therefore, if applied as is to a known fire detection system, there would be a problem in that it would take too long to detect the occurrence of a fire.
従って、本発明の目的は上述した欠点を除去し、距離分
解能によって規定される距離よりも精密な測定点毎に検
知でき、しかも火災の発生を速やかに検知できる火災検
知システムを提供するものである。SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks, to provide a fire detection system that can detect each measurement point more precisely than the distance specified by distance resolution, and can quickly detect the occurrence of a fire. .
（課題を解決するための手段）
本発明による火災検知システムは、パルス光を放射する
光源と、
複数のリング状巻同部を有し、入射パルスに基き温度に
応じた強度の後方散乱光を発生する光ファイバと、
発生した後方散乱光のうちラマン散乱光を受光する光検
出器と、
前記光検出器からの出力信号に基き各巻回部の温度を指
示する信号を順次出力する演算処理装置とを具え、
各巻回部の温度に基き火災の発生を検知することを特徴
とするものである。(Means for Solving the Problems) A fire detection system according to the present invention includes a light source that emits pulsed light and a plurality of ring-shaped windings, and emits backscattered light with an intensity that depends on the temperature based on the incident pulse. an optical fiber generated, a photodetector that receives Raman scattered light among the generated backscattered light, and an arithmetic processing device that sequentially outputs a signal indicating the temperature of each winding portion based on the output signal from the photodetector. The invention is characterized in that it detects the occurrence of a fire based on the temperature of each winding.
（作 用）
前述したように、光ファイバの温度感受特性は距離分解
能による制約を受けるため、被測定区域に光ファイバを
単に配設しただけでは、火災検知システムとして充分な
応答性を得ることができな一
い。このため、本発明では、１本の光ファイバに多数の
リング状巻回部を形成し、この巻回部を火災検知センサ
部とし、この検知センサ部の温度変化から火災の発生を
検知する。リング状巻回部付近で火災が発生すると巻回
部を構成する光フアイバ全体が受熱するため、発火区域
の面積が小さくても受熱する光ファイバ長を実質的に長
くすることができ、速やかに実際の温度を検出すること
ができる。この結果火災の発生初期に相当するような火
災の発生区域が小さい場合でも火災の発生を速やかに検
知することができる。また、リング状巻回部は所望のピ
ッチで自在に形成できるので、火災が発生する可能性の
高い区域は短いピッチで多数個の巻回部を形成し、火災
の発生する危険性の少ない区域には長いピッチでラフに
形成することもできる。さらに、受熱するファイバ長が
実質的に長くなることにより、検出温度の時間微分値も
極めて大きな値となる。この結果、温度変化の時間微分
を限界値と比較することにより、火災の発生と認定でき
る高温度に昇温する前に火災の発生を検知でき、−層速
やかに火災の発生を検知することができる。(Function) As mentioned above, the temperature sensitivity characteristics of optical fibers are limited by distance resolution, so simply placing optical fibers in the measurement area will not provide sufficient responsiveness as a fire detection system. I can't do it. Therefore, in the present invention, a single optical fiber is formed with a large number of ring-shaped windings, these windings are used as a fire detection sensor section, and the occurrence of a fire is detected from the temperature change of this detection sensor section. When a fire occurs near the ring-shaped winding, the entire optical fiber that makes up the winding receives heat, so even if the area of the ignition area is small, the length of the optical fiber that receives heat can be substantially increased, and the fire can be quickly stopped. The actual temperature can be detected. As a result, even if the fire outbreak area is small, which corresponds to the initial stage of a fire outbreak, the occurrence of a fire can be detected quickly. In addition, since the ring-shaped windings can be freely formed at a desired pitch, a large number of windings can be formed at short pitches in areas where there is a high possibility of a fire occurring, and areas with a low risk of fire can be formed. It can also be formed roughly with long pitches. Furthermore, since the length of the fiber that receives heat becomes substantially longer, the time differential value of the detected temperature also becomes an extremely large value. As a result, by comparing the time derivative of the temperature change with the limit value, it is possible to detect the occurrence of a fire before the temperature rises to a high enough temperature to indicate that a fire has occurred. can.
（実施例）
第１図は本発明による火災検知システムの一例の構成を
示す線図である。例えば半導体レーザで構成する光源１
からパルス状の光を放射する。このパルス光を集光光学
系、光カップラ２を経て光ケーブル３に投射する。光カ
ップラ２はハーフミラ−や光フアイバカップラを用いる
ことができる。(Example) FIG. 1 is a diagram showing the configuration of an example of a fire detection system according to the present invention. For example, a light source 1 composed of a semiconductor laser
emits pulsed light from This pulsed light is projected onto an optical cable 3 via a condensing optical system and an optical coupler 2. The optical coupler 2 can be a half mirror or an optical fiber coupler.
光ケーブル３は、グレーテッド・インデクスマルチモー
ド光ファイバを金属シース内に収容した光ケーブルを用
いる。光ファイバにパルス光を入射させると、光ファイ
バの各部位でレイリー散乱が発生すると共にラマン散乱
が発生し、レイリー散乱光及びラマン散乱光を含む光が
後方散乱光として入射側に向けて伝播する。この後方散
乱光のうち、ラマン散乱光の強度は光ファイバの温度に
強く依存して変化するから、ラマン散乱光強度を検出す
ることにより光ファイバの各部位における温度を検出す
ることができる。尚、投射パルス光としてラマン閾値以
上のパルス光及びラマン閾値以下のパルス光のいずれを
も用いることができる。The optical cable 3 is an optical cable in which a graded index multimode optical fiber is housed in a metal sheath. When pulsed light is input into an optical fiber, Rayleigh scattering and Raman scattering occur at each part of the optical fiber, and light including Rayleigh scattered light and Raman scattered light propagates toward the input side as backscattered light. . Among the backscattered lights, the intensity of the Raman scattered light varies depending strongly on the temperature of the optical fiber, so by detecting the intensity of the Raman scattered light, the temperature at each part of the optical fiber can be detected. Note that as the projection pulsed light, either pulsed light with a Raman threshold value or more and pulsed light with a Raman threshold value or less can be used.
光ケーブル３には複数のリング状巻回部３８〜３１を形
成し、これら巻回部を火災検知センサ部とする。A plurality of ring-shaped winding parts 38 to 31 are formed on the optical cable 3, and these winding parts are used as a fire detection sensor part.
これら巻回部は所望のピッチで所望の位置に形成できる
。リング状巻回部３８〜３１は、用いる光ファイバと温
度計測システムによって決まる最短均熱長以上の長さを
巻回することが望ましい。ここで、最短均熱長は以下の
ように定義する。光ファイバに沿って温度Ｔの矩形状の
温度分布区域が存在すると想定した場合、距離分解能の
影響によって、矩形状温度分布区域の中央部が最高温度
となりその両端部分がなだらかに低下する温度分布とし
て検出される。この場合矩形区域の中央部が温度Ｔとし
て検出されるには矩形状の温度区域が所定の長さ！。よ
りも長くならなければならない。この長さ！。は光ファ
イバ及び温度計測システムによって規定され、この長さ
！。を最短均熱長と規定する。従って、例えば７．５ｍ
の距離分解能の場合約１５ｍ程度巻回して１個の巻回部
を構成する。また、巻回方法として、周囲空間から光ケ
ーブルへの熱伝達を良好にするため光フアイバケーブル
の表面領域が広く露出するように各リングが互いに重な
り合わないようにずらして巻回することが望ましく、リ
ングをずらして同心状に巻回したり、或は同一径のリン
グが一方向にずれるように巻回する。このように、各リ
ングが互いに重なり合わないようにずらして巻回するこ
とにより、各リング部の光ファイバの受熱量が増大し、
−層速やかに温度検出することができる。These winding portions can be formed at any desired pitch and at any desired position. It is desirable that the ring-shaped winding parts 38 to 31 be wound to a length equal to or longer than the shortest soaking length determined by the optical fiber and temperature measurement system used. Here, the shortest soaking length is defined as follows. Assuming that there is a rectangular temperature distribution area with temperature T along the optical fiber, due to the effect of distance resolution, the temperature distribution will be such that the center of the rectangular temperature distribution area has the highest temperature and the temperature gradually decreases at both ends. Detected. In this case, in order for the center of the rectangular area to be detected as temperature T, the rectangular temperature area must have a predetermined length! . must be longer than This length! . is defined by the optical fiber and temperature measurement system, and this length! . is defined as the shortest soaking length. Therefore, for example 7.5m
In the case of a distance resolution of , one winding section is formed by winding approximately 15 m. In addition, as for the winding method, in order to improve heat transfer from the surrounding space to the optical cable, it is desirable to wind the rings in a staggered manner so that the rings do not overlap each other so that the surface area of the optical fiber cable is widely exposed. The rings may be staggered and wound concentrically, or rings of the same diameter may be wound so as to be staggered in one direction. In this way, by winding the rings in a staggered manner so that they do not overlap each other, the amount of heat received by the optical fiber in each ring portion increases.
- The temperature of the layer can be detected quickly.
各巻回部３８〜３１からの後方散乱光は、光ファイバ３
を入射側に向けて伝播し、光カップラ２を経て干渉フィ
ルタ４に入射し、ラマン散乱光のうち特定の波長域の光
だけが光検出器５に入射する。Backscattered light from each winding portion 38 to 31 is transmitted to the optical fiber 3
The light propagates toward the incident side, passes through the optical coupler 2, enters the interference filter 4, and among the Raman scattered light, only light in a specific wavelength range enters the photodetector 5.
この光検出器５は高周波数で対応できるアバランシェフ
ォトダイオードで構成する。光検出器５からの出力信号
をＡ／Ｄ変換器６によりデジタル信号に変換して演算処
理装置７に供給する。演算処理装置７では、ラマン散乱
光の強度及び到達時間に基いて光ファイバの各巻回部３
８〜３１の温度を順９−
０−
次出力する。そして、各巻回部の検出温度はモニタ８に
表示され、監視者はモニタに表示された温度情報に基い
て被測定域の温度状態を監視することができる。演算処
理装置７で求めた各巻回部の温度情報をバッファ９に一
旦記憶し、微分器１０において各巻回部３ａ〜３１の温
度変化の時間微分ｄＴ／ｄｔを求め、その値を第１比較
器１１に供給する。第１比較器では、昇温速度の限界値
に相当する時間微分の限界値を予め記憶しておき、順次
入力する温度変化の時間微分値を限界値と比較し、検出
した時間微分値が限界値を超えた場合出力信号をアンド
ゲート１２に供給する。さらに、演算処理装置７で求め
た各巻回部の温度情報を別のバッファ１３に一旦記憶し
、順次第２比較器１４及び第３比較器１５にそれぞれ供
給する。第２比較器１４において、各巻回部の温度を第
１の限界温度と比較する。この第１の限界温度は、各巻
回部の周囲状況を考慮し火災の発すと認定できる温度よ
りも若干低い温度に設定し、例えばトンネル火災の検知
に使用する場合季節変動や日照変化を加味したトンネル
内の平常の温度よりも例えば１０″Ｃ高い温度に設定す
る。そして、各巻回部の温度が第１の限界温度を超えた
場合アンドゲート１２に出力信号を発生し、この出力信
号をオアゲート１６に供給する。第３の比較器１５にお
いて、火災の発生と認定できる第１の限界温度よりも高
い第２の限界温度と比較し、この第２の限界温度を超え
た場合オアゲート１Ｇに出力信号を供給して警報信号を
発生する。これらの比較動作は、タイミングコントロー
ラ （図示せず）によって各測定部位毎に同期して行な
う。温度変化の時間微分は、各測定部位における温度上
昇の目安とすることができる。よって、時間微分ｄＴ／
ｄｔを限界値と比較することにより異常事態が発生した
と判断でき、火災発生初期にみられる急激な温度上昇に
基き火災の発生を速やかに検知できる。一方、時間微分
だけがら判断した場合誤報となるおそれもある。このた
め、本例では、第２比較器１４において検出温度が所定
の限界温度を超えているか否かを並列して判断し、検出
温度も限界値を超えた場合火災の発生と判断する。この
ように構成することにより、火災が発生してがら短時間
のうちに速やかに火災の発生を検出できると共に、誤報
の発生も未然に防止することができる。This photodetector 5 is composed of an avalanche photodiode that can handle high frequencies. The output signal from the photodetector 5 is converted into a digital signal by the A/D converter 6 and supplied to the arithmetic processing unit 7. The arithmetic processing unit 7 determines each winding portion 3 of the optical fiber based on the intensity and arrival time of the Raman scattered light.
Temperatures 8 to 31 are output in order 9-0-. The detected temperature of each winding portion is displayed on the monitor 8, and the supervisor can monitor the temperature state of the measurement area based on the temperature information displayed on the monitor. The temperature information of each winding section obtained by the arithmetic processing unit 7 is temporarily stored in the buffer 9, and the time differential dT/dt of the temperature change of each winding section 3a to 31 is obtained in the differentiator 10, and the value is sent to the first comparator. 11. The first comparator stores in advance a time differential limit value that corresponds to the limit value of the temperature increase rate, and compares the sequentially inputted time differential values of temperature changes with the limit value, and the detected time differential value is the limit value. If the value is exceeded, an output signal is supplied to the AND gate 12. Further, the temperature information of each winding portion obtained by the arithmetic processing unit 7 is temporarily stored in another buffer 13, and sequentially supplied to the second comparator 14 and the third comparator 15, respectively. A second comparator 14 compares the temperature of each winding with a first limit temperature. This first temperature limit is set at a temperature slightly lower than the temperature at which a fire can be recognized, taking into account the surrounding conditions of each winding.For example, when used for detecting tunnel fires, seasonal fluctuations and changes in sunlight are taken into account. The temperature is set to, for example, 10"C higher than the normal temperature inside the tunnel. Then, when the temperature of each winding exceeds the first limit temperature, an output signal is generated to the AND gate 12, and this output signal is passed to the OR gate. The third comparator 15 compares the temperature with the second limit temperature, which is higher than the first limit temperature at which it can be recognized that a fire has occurred, and outputs the signal to the OR gate 1G if the second limit temperature is exceeded. A signal is supplied to generate an alarm signal. These comparison operations are performed synchronously for each measurement site by a timing controller (not shown). The time differentiation of temperature change is a guideline for the temperature rise at each measurement site. Therefore, the time derivative dT/
By comparing dt with a limit value, it can be determined that an abnormal situation has occurred, and the occurrence of a fire can be quickly detected based on the rapid temperature rise seen in the early stages of a fire. On the other hand, if the judgment is based only on the time differential, there is a risk of false alarms. Therefore, in this example, it is determined in parallel whether the detected temperature exceeds a predetermined limit temperature in the second comparator 14, and if the detected temperature also exceeds the limit value, it is determined that a fire has occurred. With this configuration, it is possible to quickly detect the occurrence of a fire within a short period of time, and it is also possible to prevent false alarms from occurring.
このように温度変化の時間微分に基く検知ルートを設け
ることにより、従来の検知システムに比べて短時間で一
層速やかに火災の発生を検知できる。By providing a detection route based on the time differentiation of temperature changes in this manner, the occurrence of a fire can be detected more quickly and in a shorter time than with conventional detection systems.
次に、本発明による火災検知システムによる実験結果に
ついて説明する。屋外に幅３ｍ、高さ４ｍ、長さ７．２
ｍの模擬トンネルを設置し、トンネル中央の床面上に０
．７ｒｎＸ０．７ｍの火皿を配置しガソリンを燃焼させ
た。光ケーブルとしてコア径８５μｍ、クランド径１２
５μｍのグレーテッド・インデクスマルチモード光ファ
イバを用い、この光ファイバを直径１．２ｍｍの金属シ
ース内に収容したものを使用した。この光ケーブル２０
ｍを３０ｃｍ径でリング状に巻回して巻回部を作り、こ
の巻回部をトンネルの天井部に吊り下げ検知センサ部と
した。Next, experimental results using the fire detection system according to the present invention will be explained. Outdoor width 3m, height 4m, length 7.2
A simulated tunnel of m is installed, and 0 is placed on the floor in the center of the tunnel.
．． A 7rn x 0.7m fire pan was placed to burn gasoline. As an optical cable, the core diameter is 85 μm and the crand diameter is 12
A 5 μm graded index multimode optical fiber was used, and this optical fiber was housed in a metal sheath with a diameter of 1.2 mm. This optical cable 20
m was wound into a ring shape with a diameter of 30 cm to form a wound portion, and this wound portion was suspended from the ceiling of the tunnel to serve as a detection sensor portion.
この結果を第２図に示す。第２図において横軸は発火後
の経過時間を示し、縦軸は検出温度を示す。The results are shown in FIG. In FIG. 2, the horizontal axis shows the elapsed time after ignition, and the vertical axis shows the detected temperature.
第２図において、実線は火皿の真上に設置した巻回部の
検出温度を示し、−点鎖線は火皿の真上から１ｍ横に変
位した位置の温度変化を示し、２点鎖線は巻回せず光ケ
ーブルを直線状に敷設したときの温度を示す。また、破
線は火皿の真上に設置した熱電対によって検出された温
度変化を示す。In Fig. 2, the solid line indicates the detected temperature of the winding section installed directly above the fire pan, the - dotted line indicates the temperature change at a position displaced 1 m horizontally from directly above the fire pan, and the two-dot chain line indicates the temperature at the winding section installed directly above the fire pan. This shows the temperature when the optical cable is laid in a straight line. Moreover, the broken line shows the temperature change detected by the thermocouple installed directly above the fire pan.
実線で示す本発明による温度検出センサは、発火後数秒
経過してから昇温を開始し、極めて急激な昇温特性を示
し、約４０秒経過後に飽和に近づいている。また−点鎖
線で示す火皿から１ｍ変位した位置の昇温特性も同様に
急激な立上がりを示している。さらに、光ケーブルを直
線状に敷設した場合昇温かはるかにゆるやかであった。The temperature detection sensor according to the present invention, indicated by the solid line, starts to rise in temperature several seconds after ignition, exhibits extremely rapid temperature rise characteristics, and approaches saturation after about 40 seconds have elapsed. Furthermore, the temperature rise characteristic at a position 1 m away from the fire pan, indicated by the - dotted chain line, similarly shows a rapid rise. Furthermore, the temperature rise was much more gradual when the optical cable was laid in a straight line.
これに対して、熱電対による検出結果は、比較的ゆるや
かな昇温特性を示し、５０〜７０°Ｃにおける昇温速度
は本発明による温度検出センサの約１７３程度であった
。On the other hand, the detection result using the thermocouple showed a relatively gradual temperature increase characteristic, and the temperature increase rate at 50 to 70°C was about 173 times higher than that of the temperature detection sensor according to the present invention.
本発明は上述した実施例だけに限定されず種々の変形や
変更が可能である。上述した実施例では、温度検出セン
サとして光ファイバを金属シース内に収容した光ケーブ
ルを用いたが、光ファイバそのものを温度検出センサと
して用いることができ、３
４
或いは光ファイバを耐熱性繊維やシリコン樹脂等の耐熱
性樹脂で被覆した光ファイバを用いることもできる。The present invention is not limited to the embodiments described above, and various modifications and changes are possible. In the above-mentioned embodiment, an optical cable in which an optical fiber is housed in a metal sheath is used as a temperature detection sensor, but the optical fiber itself can be used as a temperature detection sensor. It is also possible to use an optical fiber coated with a heat-resistant resin such as.
さらに、バッファ、微分器、比較器の処理系を複数個並
列に接続して並列処理することもできる。Furthermore, a plurality of processing systems including buffers, differentiators, and comparators can be connected in parallel to perform parallel processing.
（発明の効果）
以上説明した本発明の効果を要約すると次の通りである
。(Effects of the Invention) The effects of the present invention explained above are summarized as follows.
（］）光ファイバをリング状に巻回しこの巻回部を火災
検知センサ部としているから、受熱する光ファイバ長を
実質的に長く設定でき、この結果発火源の区域が小さく
ても発火の発生を精確に検知することができる。( ]) Since the optical fiber is wound in a ring shape and this winding part is used as the fire detection sensor part, the length of the optical fiber that receives heat can be set to be substantially long, and as a result, ignition can occur even if the ignition source area is small. can be detected accurately.
（２） リング状巻回部は所望の位置に、所望のピッ
チで形成できるので、発火源となるおそれの濃い区域に
密集して配置でき、火災の監視をより能率的に行なうこ
とができる。(2) Since the ring-shaped windings can be formed at desired positions and at desired pitches, they can be densely arranged in areas that are highly likely to become ignition sources, making it possible to monitor fires more efficiently.
（３）検知センサ部の受熱量が一層大きくなるので、火
災に対する昇温検出の応答性が極めて良好であり、この
結果、発火後極めて短時間で火災の発生を検知すること
ができる。(3) Since the amount of heat received by the detection sensor section is further increased, the responsiveness of temperature rise detection to a fire is extremely good, and as a result, the occurrence of a fire can be detected in an extremely short time after ignition.
（４）温度検出の応答性が良好なため、温度変化の時間
微分を限界値と比較することにより、火災が発生したと
判断する基準温度を低く設定でき、この結果、発火から
より一層短い時間で火災の発生を検知することができる
。(4) Since the responsiveness of temperature detection is good, by comparing the time derivative of temperature change with the limit value, the reference temperature for determining that a fire has occurred can be set low, resulting in a shorter time from ignition. can detect the occurrence of a fire.
第１図は本発明による火災検知システムの一例の構成を
示す線図、
第２図は本発明による火災検知システムの発火からの経
過時間と検出温度との関係を示すグラフである。
１・・・光源 ２・・・光カップラ３・・
・光ケーブル ３ａ〜３１・・・巻回部５・・・
光検出器 ７・・・演算処理装置９・・・バッ
ファ １０・・・微分器１１、１４．１５・・
・比較器 １２・・・アンドゲート１６・・・オアゲ
ートFIG. 1 is a diagram showing the configuration of an example of the fire detection system according to the present invention, and FIG. 2 is a graph showing the relationship between the elapsed time from ignition and detected temperature in the fire detection system according to the present invention. 1... Light source 2... Optical coupler 3...
・Optical cable 3a to 31... Winding part 5...
Photodetector 7... Arithmetic processing unit 9... Buffer 10... Differentiator 11, 14.15...
・Comparator 12...And gate 16...Or gate
Claims (1)
に応じた強度の後方散乱光を発生する光ファイバと、 発生した後方散乱光のうちラマン散乱光を受光する光検
出器と、 前記光検出器からの出力信号に基き各巻回部の温度を指
示する信号を順次出力する演算処理装置とを具え、 各巻回部の温度に基き火災の発生を検知することを特徴
とする火災検知システム。 ２、パルス光を放射する光源と、 複数のリング状巻回部を有し、入射パルス光に基き温度
に応じた強度の後方散乱光を発生する光ファイバと、 発生した後方散乱光のうちラマン散乱光を受光する光検
出器と、 前記光検出器からの出力信号に基き各巻回部の温度を指
示する信号を順次出力する演算処理装置と、 各巻回部の温度変化の時間微分を出力する微分器とを具
え、 温度指示信号と微分信号とに基き火災の発生を検知する
ことを特徴とする火災検知システム。 ３、前記光ファイバが金属シース内に収容されているこ
とを特徴とする請求項１又は２に記載の火災検知システ
ム。 ４、前記リング状巻回部が、光ファイバと温度計測シス
テムによって定まる最短均熱長以上の長さに亘って巻回
されていることを特徴とする請求項１、２又は３に記載
の火災検知システム。 ５、前記微分信号を基準限界値と比較する第１の比較器
と、 前記温度指示信号を第１の基準限界温度と比較する第２
の比較器と、 前記温度指示信号を第１の基準限界温度より高い第２の
基準限界温度と比較する第３の比較器と、 前記第１及び第２比較器からの出力信号が入力したとき
出力信号を発生するアンドゲートと、 前記アンドゲートからの出力信号又は第３比較器からの
出力信号の少なくとも一方の出力信号が入力したとき火
災の発生を表示する警報信号を発生するオアゲートとを
さらに具えることを特徴とする請求項２から４までのい
ずれか１項に記載の火災検知システム。[Claims] 1. A light source that emits pulsed light; an optical fiber that has a plurality of ring-shaped windings and that generates backscattered light with an intensity that depends on the temperature based on the incident pulsed light; A photodetector that receives Raman scattered light among the backscattered light, and an arithmetic processing device that sequentially outputs a signal indicating the temperature of each winding part based on the output signal from the photodetector, A fire detection system that detects the occurrence of a fire based on temperature. 2. A light source that emits pulsed light; an optical fiber that has a plurality of ring-shaped windings and generates backscattered light with an intensity that depends on the temperature based on the incident pulsed light; and Raman of the generated backscattered light. a photodetector that receives scattered light; an arithmetic processing device that sequentially outputs a signal indicating the temperature of each winding section based on the output signal from the photodetector; and an arithmetic processing unit that outputs a time differential of a temperature change of each winding section. A fire detection system comprising a differentiator and detecting the occurrence of a fire based on a temperature indication signal and a differential signal. 3. The fire detection system according to claim 1 or 2, wherein the optical fiber is housed within a metal sheath. 4. The fire according to claim 1, 2 or 3, wherein the ring-shaped winding portion is wound over a length equal to or longer than the shortest soaking length determined by the optical fiber and the temperature measurement system. detection system. 5. A first comparator for comparing the differential signal with a reference limit value; and a second comparator for comparing the temperature indication signal with a first reference limit temperature.
a third comparator that compares the temperature indication signal with a second reference limit temperature higher than the first reference limit temperature; when the output signals from the first and second comparators are input; an AND gate that generates an output signal; and an OR gate that generates an alarm signal indicating the occurrence of a fire when at least one of the output signal from the AND gate or the output signal from the third comparator is input. The fire detection system according to any one of claims 2 to 4, further comprising a fire detection system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1273657A JP2823900B2 (en) | 1989-10-23 | 1989-10-23 | Fire detection system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1273657A JP2823900B2 (en) | 1989-10-23 | 1989-10-23 | Fire detection system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03136195A true JPH03136195A (en) | 1991-06-10 |
| JP2823900B2 JP2823900B2 (en) | 1998-11-11 |
Family
ID=17530740
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1273657A Expired - Fee Related JP2823900B2 (en) | 1989-10-23 | 1989-10-23 | Fire detection system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2823900B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3321905A1 (en) * | 2016-11-11 | 2018-05-16 | Kidde Technologies, Inc. | High sensitivity fiber optic based detection |
| EP3321908A1 (en) * | 2016-11-11 | 2018-05-16 | Kidde Technologies, Inc. | Fiber optic based monitoring of temperature and/or smoke conditions at electronic components |
| WO2018089474A1 (en) * | 2016-11-11 | 2018-05-17 | Carrier Corporation | High sensitivity fiber optic based detection |
| WO2018089477A1 (en) * | 2016-11-11 | 2018-05-17 | Carrier Corporation | High sensitivity fiber optic based detection |
| EP3809384A1 (en) * | 2019-10-16 | 2021-04-21 | Hamilton Sundstrand Corporation | Environmental condition sensing system |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03683A (en) * | 1989-05-17 | 1991-01-07 | Nakanishi Gijiyutsushi Jimusho:Kk | Fire detector for floating roof tank |
-
1989
- 1989-10-23 JP JP1273657A patent/JP2823900B2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03683A (en) * | 1989-05-17 | 1991-01-07 | Nakanishi Gijiyutsushi Jimusho:Kk | Fire detector for floating roof tank |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3321905A1 (en) * | 2016-11-11 | 2018-05-16 | Kidde Technologies, Inc. | High sensitivity fiber optic based detection |
| EP3321908A1 (en) * | 2016-11-11 | 2018-05-16 | Kidde Technologies, Inc. | Fiber optic based monitoring of temperature and/or smoke conditions at electronic components |
| WO2018089474A1 (en) * | 2016-11-11 | 2018-05-17 | Carrier Corporation | High sensitivity fiber optic based detection |
| WO2018089477A1 (en) * | 2016-11-11 | 2018-05-17 | Carrier Corporation | High sensitivity fiber optic based detection |
| CN108072505A (en) * | 2016-11-11 | 2018-05-25 | 基德科技公司 | Detection based on high sensitivity optical fiber |
| US10665075B2 (en) | 2016-11-11 | 2020-05-26 | Kidde Technologies, Inc. | Fiber optic based monitoring of temperature and/or smoke conditions at electronic components |
| US10852202B2 (en) | 2016-11-11 | 2020-12-01 | Kidde Technologies, Inc. | High sensitivity fiber optic based detection |
| US10943449B2 (en) | 2016-11-11 | 2021-03-09 | Carrier Corporation | High sensitivity fiber optic based detection |
| US11087606B2 (en) * | 2016-11-11 | 2021-08-10 | Carrier Corporation | High sensitivity fiber optic based detection |
| CN108072505B (en) * | 2016-11-11 | 2022-06-14 | 基德科技公司 | High sensitivity optical fiber based detection |
| EP3809384A1 (en) * | 2019-10-16 | 2021-04-21 | Hamilton Sundstrand Corporation | Environmental condition sensing system |
| US11713985B2 (en) | 2019-10-16 | 2023-08-01 | Hamilton Sundstrand Corporation | Environmental condition sensing system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2823900B2 (en) | 1998-11-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6688093B2 (en) | Fire and intrusion detection and notification system | |
| CN115240357B (en) | Public building fire scene temperature real-time monitoring and predicting system based on distributed optical fiber | |
| CN110333673A (en) | A kind of cable shaft method of environmental monitoring, system and equipment based on Internet of Things | |
| JP3358948B2 (en) | Tunnel danger prediction system | |
| JPH03136195A (en) | Fire detection system | |
| CN110264660A (en) | A kind of accurate positioning intelligent fiber grating fire detecting system | |
| CN1138694A (en) | Optical fiber type fire sensor system | |
| CN2844873Y (en) | Distributed optical fiber based electric cable temperature inspecting device | |
| JPH0836681A (en) | Fire detection equipment using optical fiber | |
| JPH07200961A (en) | Fire alarm system for early detection of fire | |
| JP3172854B2 (en) | Disaster prevention system for tunnel type structures | |
| JPH07275392A (en) | Disasters preventive system | |
| JPH0712655A (en) | Measurement system | |
| JP2781269B2 (en) | Optical fiber sensor | |
| KR101949825B1 (en) | Method for detecting invasion | |
| JP2642841B2 (en) | Optical fiber composite power cable | |
| JP2004152134A (en) | Fire detector | |
| JP2018503914A (en) | Building monitoring system | |
| JPH11283136A (en) | Fire alarm device | |
| CN111103067A (en) | Cable trench temperature monitoring method and system based on single-mode optical fiber | |
| JP3380160B2 (en) | Fire alarm device, fire alarm method and recording medium | |
| JP2667507B2 (en) | Fire detector | |
| KR102583921B1 (en) | Multiple pipe monitoring system of converter hood and monitoring method thereof | |
| JPH0291548A (en) | Optical fiber fire sensor | |
| JP2734803B2 (en) | Optical fiber cable for fire detection |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |