JPH071205B2 - Fire detector - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a flame detection device attached to, for example, a boiler device, and more particularly to a flame detection device that optically detects a flame property.

[Conventional technology]

Accurately detecting the combustion state of various combustion devices such as large-scale boilers for business establishments is extremely important from the viewpoint of safety and economic efficiency of the combustion device.

Taking a large-scale boiler for a power plant as an example, the number of burners installed increases with the increase in capacity of the boiler.
rt Stop) Ignition of the burner due to operation, increase in the number of extinguishments, adoption of a combustion method that suppresses the generation of nitrogen oxides (NOx), and changes in combustion behavior due to diversification of fuel used It is desired to further improve the reliability of flame detection.

Generally, flame detection methods can be roughly divided into an ion flame detection device and an optical flame detection device. Since the ion-type flame detection device uses a flame contact electrode as a sensor, it cannot be continuously used for a long period of time, and the range of use is usually limited to flame detection for an ignition burner. On the other hand, the optical flame detection device, depending on the magnitude of the emission intensity from the flame,
It is used to judge whether ignition or extinguishing is to be performed. It can be classified into a wavelength detection method and a DC light detection method and a flickering detection method.

FIG. 21 is a schematic configuration diagram of a conventional optical flame detection device. As shown in the figure, one or a plurality of heat-resistant mirrors 103 are arranged in a cylindrical light guide tube 102 having one opening 101 on the side surface at the tip. Then, the light 105 from the flame is guided into the light guide tube 102 through the opening 101, reflected by the mirror 103 and received by the sensor 104 such as a silicon photocell,
It has a mechanism for photoelectrically converting and transmitting it as an electric signal to a control unit (not shown).

Although the composition of this optical flame detection device is simple, the field of view for flame detection is limited to one. Since the primary combustion zone with high flame brightness moves away from or near the tip of the burner due to load fluctuations, the single field of view as described above has the drawback of low flame detection accuracy. Moreover, the narrow detection field makes it difficult to distinguish the light from other flames from the light of the flame of the burner to be detected, and often causes a detection error.

Further, the conventional determination of the optical flame detection has been performed as follows. That is, the threshold for flame detection determination set in advance and the magnitude relationship of the detected light amount are simply compared, and when the detected light amount does not reach the threshold value, there is no flame (while extinguishing). When the light quantity detected is higher than the threshold value, it is determined that there is flame (combustion), and this judgment signal is output to an alarm device or a monitor device.

In some complicated flame detection devices, a threshold for flame detection determination is set for each type of fuel, but only one threshold is set for each fuel.
Therefore, even if the range of use of fuel is expanded, the detection accuracy itself is not improved, and the detection operation becomes rather complicated.

Furthermore, in the actual flame detection, there is a problem in the judgment logic itself that the one with the larger light quantity is burning,
The burner that performs flame detection may detect a higher light amount when the fire is extinguished.

This will be described with reference to FIGS. 22 and 23. When detecting the presence or absence of ignition of the ignition burner 106 by the flame detection device 107, even if the ignition burner 106 is extinguished as shown in FIG. 22, a large amount of light of the flame F ₁ of the main burner 108 is detected. Thus, the amount of light received by the sensor in the flame detection device 107 becomes large. On the other hand, as shown in Fig. 23, the ignition burner
When 106 is ignited, the light from the flame F ₁ of the main burner 108 is blocked by the flame F ₂ of the ignition burner 106, so that the amount of light received by the sensor decreases. For this reason, the above decision logic will make a wrong decision, and will output a wrong signal to the combustion supply system or the like.

This may cause an erroneous determination not only between the ignition burner and the main burner but also in the case of a cell burner in which a plurality of burners are arranged close to each other.

[Problems to be solved by the invention]

The conventional optical flame detection device has one burner for one burner.
There were two flame detection means.

On the other hand, the flame shape varies depending on the type of fuel, the difference in combustion conditions such as air amount / fuel amount, the state of load, the position of the burner to be monitored in the furnace. Further, for maintenance inspection of the flame detector, if the flame detector is once pulled out for maintenance inspection and then the flame detector is mounted, the angle at which the flame detector faces the burner (flame) may differ.

For this reason, if the flame is monitored by one flame detecting means, it may be judged that there is no flame even if there is a flame, and the reliability of the flame detector is low. there were.

SUMMARY OF THE INVENTION The present invention is intended to eliminate such a conventional drawback, and an object of the present invention is to provide a flame detection device with high detection accuracy.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a lighting head 1
For each burner, for example, a plurality of flame detection means having different detection modes, such as different viewing angles or (and) absorption wavelength regions for flames, are provided, and the determination unit determines whether or not a flame is present in the burner. The determination is weighted for each of the plurality of flame detection means.

〔Example〕

Next, a flame detecting device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 20. Note that the description will be divided into A. the structure of the flame detector and B. the overall configuration of the flame detection device for easy understanding.

A. Flame detector structure First, the concrete structure of the flame detector will be described. Second
The figure is a partial cross-sectional view showing an arrangement state of flame detectors in a large-scale boiler device.

In the figure, 1 is a flame detector, 2 is a furnace, 3 is a heat transfer tube, 4 is a flame plate, 5 is a main burner, 6 is primary air, 7 is exhaust gas, 8 is secondary air, 9 is tertiary air, 10 Is a sleeve. As shown in FIG. 2, the flame detector 1 is arranged substantially parallel to the main burner 5, and the tip portion thereof extends close to the flame F formed by the main burner 5.

In this arrangement example, the flame detector 1 is arranged above the main burner 5, but the flame detector 1 may be arranged below the main burner 5 (see FIG. 1).

FIG. 1 is a schematic configuration diagram of the entire flame detection device. The flame detection device is mainly composed of a flame detector 1 provided corresponding to the number of burners installed, an O / E amplifier board 11, and a frame detector control unit 12. Specific configurations of the O / E amplifier board 11 and the frame detector control unit 12 will be described later in detail.

Next, the structure of the flame detector 1 described above will be described. FIG. 3 is a sectional view of a main part of the flame detector 1, FIGS. 4, 5, and 6 are side views, front views and rear views of the daylighting head, and FIG. 7 is on line XX in FIG. Sectional views, FIGS. 8 and 9 are a cutaway side view and a front view of the protective member.

In FIG. 3, reference numeral 13 denotes an outer cylinder, which is made of a heat-resistant and corrosion-resistant material such as a stainless steel pipe. A protective member 14 is attached by screws 15 near the tip of the outer cylinder 13. Has been. The protective member 14 is made of a material having excellent heat resistance such as ceramics, and the protective member 14 is formed into a cap shape as shown in FIGS. 8 and 9. As shown in FIG. 3, FIG. 8 and FIG. 9, a slit 16 for light detection is provided on the tip surface of the protective member 14,
A spacer portion 17 is formed on the outer peripheral surface in the longitudinal direction thereof, and a screw hole 18 for attachment is provided in the spacer portion 17 as shown in FIG. Note that 19 in FIG. 8 is a screw hole for attaching the daylighting head 20 to the spacer portion 17. As shown in FIGS. 3 and 9, this protective member
By mounting 14 in the outer cylinder 13, the cooling air 21 is provided between the outer cylinder 13 and the protective member 14 by the spacer portion 17 described above.
A space 22 through which the air flows is formed.

As shown in FIG. 3, a lighting head 20 is provided in the hollow portion of the protective member 14.
The tip of the is inserted and screwed. As shown in FIGS. 4 to 7, the daylighting head 20 comprises an optical fiber support member 23, three daylighting optical fibers 24 made of, for example, quartz glass, and a ferrule 25.

The optical fiber support member 23 is made of a heat resistant material such as stainless steel or ceramics, and is provided in FIGS.
As shown in the figure, tip end holding grooves 26 are formed in the tip end portion so as to extend in three directions. A communication groove 27 is provided in an intermediate portion of the optical fiber support member 23, and a recessed ferrule fitting portion 28 is formed at the rear end. Through holes 29 are formed at positions of the front end and the rear end of the communication groove 27 so as to penetrate from one side surface to the other side surface.

The ferrule 25 is also made of a heat resistant material such as stainless steel or ceramics, and is fitted to the ferrule fitting portion 28 via an adhesive 30, as shown in FIGS. 4 and 7.
To be glued. As shown in FIGS. 6 and 7, three insertion holes 31 arranged in parallel are formed in the substantially central portion, and two positioning holes 32 are provided at a position slightly apart from the insertion holes 31. There is.

Adhesive 33 is applied to the rear end of the first fiber optic fiber 24a, and the adhesive 33 is inserted into the insertion hole 31a of the ferrule 25 to accommodate the middle portion of the fiber optic 24a in the communication groove 27 and the tip portion. Is inserted into the holding groove 26a. Similarly, the second
Apply adhesive 33 to the rear end of the light fiber 24b for lighting,
It is inserted into the insertion hole 31b of the ferrule 25, the intermediate portion of the optical fiber 24b is housed in the communication groove 27, and the tip portion is inserted into the holding groove 26b. Further, the adhesive 33 is applied to the rear end portion of the third daylighting optical fiber 24c, the adhesive 33 is inserted into the insertion hole 31c of the ferrule 25, and the intermediate portion of the optical fiber 24c is accommodated in the communication groove 27. Insert the tip into the holding groove 26c. Each optical fiber 24a, 24b, 24c
After the rear end of the ferrule 25 is adhered and fixed to the ferrule 25, the end face of the ferrule 25 and the end faces of the optical fibers 24a, 24b, 24c are ground to be flush with each other.

As shown in FIG. 4, the first tip end holding groove 26a is the connecting groove 2
7, the second tip holding groove 26b is inclined at an inclination angle Θ of about 15 degrees with respect to the first tip holding groove 26a, and the third tip holding groove 26b is further inclined. The holding groove 26c is further inclined with respect to the second tip holding groove 26b with an inclined surface Θ of about 15 degrees, and each tip holding groove 26a, 26b, 26c.
Insert the tip of each fiber optic fiber 24a, 24b, 24c into
Is held. Therefore, the first light collecting fiber 24a has a field of view 34a in the direction of a tilt angle of 0 degrees, the second light collecting fiber 24b has a field of view 34b in the direction of a tilt angle of about 15 degrees, and the third light collecting fiber 24c has a tilt angle of 30 degrees. It has a visual field 34c in the direction of about 30 degrees, and three detection visual fields are obtained by these, and the detection range is expanded. The optical fiber is about 30
It has been confirmed that the deterioration of the optical transmission efficiency does not hinder the practical use in the bending up to a degree.

Further, as shown in FIG. 5, the depths of the tip end holding grooves 26a, 26b, 26c are sequentially different, and the difference in depth is equal to or larger than the outer diameter of the light collecting fiber 24. In the connecting groove 27, as shown in FIG. 7, three lighting fibers 24a, 24b,
Since the 24c are housed in parallel, it is impossible for the daylighting optical fibers 24a, 24b, 24c by sequentially changing the depths of the tip holding grooves 26a, 26b, 26c as described above. It is possible to hold the tips without twisting.

Further, the groove widths of the tip end holding groove 26 and the connecting groove 27 are designed to allow the daylighting optical fiber 24 to be gently inserted. This is to prevent undue stress from being generated in the optical fiber 24 due to the difference in thermal expansion between the optical fiber support member 23 and the optical fiber 24.

As shown in FIG. 3, the lighting head 20 having the above-mentioned structure has three optical fibers for relay via the connector 35.
Connected to 36. Although not shown, the tip ends of the three optical fibers 36 for relay are lined up in a row in the connector 35.
The optical fiber 36 for relay has a tip end surface exposed from the end surface of the connector 35. Also, the connector 35
Two pins are provided at the tip of the connector, and the pins are inserted into the holes 32 shown in FIG. 6 and the connector 35 is fitted to the rear end of the support member 23, so that the first lighting optical fiber 24a. The rear end surface of the first relay optical fiber 36a and the rear end surface of the second relay optical fiber 24b are connected to the rear end surface of the second relay optical fiber 24b.
The front end surface of 6b is such that the rear end surface of the third light-collecting optical fiber 24c and the front end surface of the third relay optical fiber 36c face each other.

FIG. 10 is an enlarged sectional view of the relay optical fiber 36.
As shown in the figure, the relay optical fiber 36 comprises three layers of a core 37, a cladding 38 provided on the outer periphery of the core 37, and a protective layer 39 provided on the outer periphery of the cladding 38. The optical fibers 36 are collectively housed in the tube 40. The protective layer 39 and the tube 40 described above are provided to impart mechanical properties such as bendability to the relay optical fiber 36, and are made of materials such as fluorine resin, polyamide resin, silicone resin and vinyl resin. To be Also, if necessary, the optical fiber 36 for relay and the tube
It is also possible to provide a filling layer in the gap with 40.

As shown in FIG. 3, the tip of the relay optical fiber 36 is connected to the daylighting head 20 through the connector 35, while the rear end thereof extends to the flame detector main body 41 in the window box (not shown). It is connected to a wiring optical fiber 43 via a connector 42. The intermediate portion of the relay optical fiber 36 is housed in the protective pipe 44.

FIG. 11 is a partially enlarged sectional view of the protection pipe 44. The protection pipe 44 includes a large-diameter first protection pipe 44a, an intermediate-diameter second protection pipe 44b arranged concentrically with a space 45a inside thereof, and a space 45b concentric with the space 45a inside thereof. It has a triple structure with the small-diameter third protection pipe 44c arranged at. As shown in the figure, the second protection pipe 44b
The outer peripheral surface is provided with a mirror finishing layer 46, which reflects a considerable amount of the heat ray 47 transmitted from the first protective pipe 44a. In addition, a space 45a formed between the first protection pipe 44a and the second protection pipe 44b and a space 45b formed between the second protection pipe 44b and the third protection pipe 44c serve as heat insulating layers, respectively. It is working.
Then, the cooling air 21 circulates inside the third protection pipe 44c. Therefore, the reflection by the mirror finishing layer 46 described above,
Due to the heat insulation by the double spaces 45a and 45b and the circulation of the cooling air 21, it is possible to suppress the adverse thermal effect on the relay optical fiber 36.

As shown in FIG. 3, the flame detector main body 41 has a cooling air 21
An intake port 48 is provided, and the cooling air 21 taken in from there passes through the inside of the protection pipe 44 (third protection pipe 44c) as shown by the arrow to the front side, where the daylight head 20 and the protection member 14 are connected. Through the gap 16 and is ejected from the slit 16 of the protection member 14. In addition, the cooling air 21 coming through the protective pipe 44
A part of this is ejected forward through the gap between the protection member 14 and the outer cylinder 13. By circulating the cooling air 21 in this manner, the daylighting optical fiber 24 and the relaying optical fiber are obtained.
It helps prevent thermal damage to 36 and prevents contamination of the tip of the lighting fiber 24 by dust or the like. When the inner side of the outer cylinder 13 is 32 mm, it is sufficient that the flow velocity of the cooling air 21 is 0.3 m / mm.

The wiring optical fiber 43 connected to the rear end of the optical relay fiber 36 is also composed of three wires, and faces the end surface of each optical fiber relay 36 by the connector 42. The wiring optical fiber 43 also has a core 37 and a cladding provided on the outer periphery thereof, as shown in FIG. 12, similarly to the relay optical fiber 36.
The wiring optical fiber 43 is made up of three layers, that is, a protective layer 39 provided on the outer periphery of the cladding 38, and the three optical fibers 43 for wiring are collectively housed in the tube.

Figure 12 shows the fiber optics for daylighting 24 and the fiber optics for relaying.
FIG. 16 is an enlarged cross-sectional view showing a facing state of 36 and the wiring optical fiber 43. As shown in the figure, the fiber optics for lighting 24
Only the protective layer 39 is not formed. When the protective layer 39 is made of the organic material as described above, the absence of the protective layer 39 is advantageous in terms of heat resistance. Also, an optical fiber for lighting
The outer diameter D1 of 24 of the cladding 38, the outer diameter D2 of the cladding 38 of the relay optical fiber 36, and the cladding of the wiring optical fiber 43.
The outer diameter D3 of 38 is different from each other. In this example D1 =
80 μm, D2 = 400 μm, D3 = 200 μm, so the outer diameters are in the relationship of D1>D2> D3. By changing the outer diameter of each optical fiber in this way, when connecting the optical fibers to each other, the optical signal of Since the transmission is performed, the connection becomes easy.

Further, by increasing the diameter of the light collecting fiber 24 to the maximum, the amount of light can be increased as much as possible.
Further, since the wiring optical fiber 43 is thinned out from the flame detector main body 41 to the control device, there are many places where it is bent on the way. Therefore, in the present embodiment, the optical fiber having the smallest diameter with good bendability is selected as the optical fiber for wiring 43.
Is used as.

B. Overall Configuration of Flame Detection Device As shown in FIG. 1, the rear end of the optical fiber 43 for wiring is
It is connected to each photoelectric converter 49 of the O / E amplifier board 11, and accordingly, the photoelectric converters 49 are provided as many as the number of flame detectors 1.

FIG. 13 and FIG. 14 are a plan view and a partially sectional side view of the photoelectric converter 49. As shown in the figure, the photoelectric converter 49 includes a casing 50 having one surface opened, a transparent glass 51 provided in the opening, a support body 53 having three through holes 52 arranged side by side, and a support body From the three visible light receiving elements 54 (see FIG. 13) made of, for example, silicon photodiodes arranged on the through holes 52 of the body 53, and the three lead sulfide photoconductors arranged below the through holes 52, for example. The infrared light receiving element 55, a circuit board 56, and a plurality of terminal pins 57 protruding from the circuit board 56.

The visible light receiving element 54 and the infrared light receiving element 55 are arranged in pairs on the same line, and the first wiring optical fiber 43a, the second wiring optical fiber 43b, and the third wiring optical fiber 43c.
It faces the end face of. FIG. 15 is a wavelength characteristic diagram of a silicon photodiode, and FIG. 16 is a wavelength characteristic diagram of a photoconductor made of lead sulfide. As can be seen from these figures, the wavelength range that has the detection sensitivity is a silicon photodiode, which is about 0.
5 to 1.0 μm, and the lead sulfide photoconductor has a thickness of about 1 to 3 μm.

Of the optical signal from the flame F guided by the wiring optical fiber 43, the short-wavelength component is first absorbed by the visible light receiving element 54, the long-wavelength component is transmitted, and is absorbed by the next infrared light receiving element 55. To be done. In this way, the visible light receiving element 54 and the infrared light receiving element
By combining with 55, the detection wavelength range is expanded, so that flame detection is possible using any of petroleum, coal, and gas as fuel.

As shown in FIG. 1, the frame detector control unit 12 includes an SBC (Singl) for determination provided corresponding to the photoelectric converter 49.
e Board Control) 58, relay board 59 connected to each SBC 58, common relay board 60, and CCB (Commu
nicastion Control Board) 61 and mainly composed.

The SBC 58 has a valve opening / closing signal 6 from the burner source valve 62, respectively.
3 is input, and each SBC 58 is connected with an adjusting tool 64 including, for example, a personal computer.
The relay boards 59 are each connected to the burner control device 65. The common relay board 60 is connected to an alarm device 66 including, for example, a buzzer and a lamp. Various boiler operation conditions 67 are input to the CCB 61 for determination of flame detection, and are connected to a host computer 68.

Although the above description has described the structure of the flame detector and the overall configuration of the flame detection device, the reason for using the light amount of the interference flame for the determination reference signal is shown in FIGS. 17 to 20.
The figure will be described.

FIG. 17 is a characteristic diagram showing the relationship between the detection angle of the flame detector with respect to the burner and the flame detection output, FIG. 18 is a characteristic diagram showing the relationship between the direction of the interference flame and the maximum value of the interference output, and FIG. 19 is FIG. 20 is a characteristic diagram showing changes in the detection output of the self flame and the interference flame over time, and FIG. 20 is an explanatory diagram showing a state in which the calculated characteristic value and the current value are monitored.

Depending on the type of the main burner 5 in FIG. 2, the formation region of the flame F may be deviated to one location or a plurality of locations in the circumferential direction. On the other hand, once the flame detector 1 that has been arranged for maintenance and inspection of the flame detector 1 is pulled out and maintenance and inspection thereof is performed, and when the flame detector 1 is arranged again, the flame against the flame F of the main burner 5 Angle of detector 1 (detection angle)
Is often changed.

FIG. 17 shows that the main burner 5 is of a type in which the flame F forming region of the main burner 5 is biased to two circumferential positions.
It is a figure which shows the flame detection output characteristic when the detection angle of the flame detector 1 with respect to the flame F of FIG. This 17th
As is clear from the figure, the detection output varies depending on the detection angle of the flame detector 1 to be installed, and there is a case where the detection output hardly appears depending on the installation angle, which hinders flame detection. The characteristics shown in Fig. 17 are for a special burner that has directivity for the injection of flame F, but even with a normal burner that does not have directivity for the injection of flame, the detection output will change when the placement angle of the detector head 1 changes. fluctuate. Therefore, when the self-flame to be detected is monitored to detect the flame, it is necessary to strictly adjust the installation angle of the detector head 1 so that a large detection output can be obtained, which complicates the work.

On the other hand, in the boiler device using a large number of main burners of the type in which the flame formation region is biased to two places in the circumferential direction, the directions of the adjacent main burners are the directions in which the interference intensity is maximum and the direction in which the interference intensity is minimum. Fig. 18 shows the two cases that were set, and the effect of the adjacent burners at that time was examined.
It should be noted that this test is the maximum of the average value of the interference output when only the adjacent burners are ignited.

In the figure, ○ indicates detection output from a visible light receiving element with a viewing angle of 0 °, ● indicates detection output from an infrared receiving element with a viewing angle of 0 °, and Δ indicates a visible light receiving element with a viewing angle of 15 °. Detection output, ▲ indicates detection output from an infrared light receiving element with a viewing angle of 15 °, □ indicates detection output from a visible light receiving element with a viewing angle of 30 °, and ■ indicates infrared with a viewing angle of 30 °. It shows the detection output from the light receiving element.

As is clear from this figure, it is clear that the minimum and maximum values of the interference output of all channels are almost unchanged.

FIG. 19 is a diagram showing the self-flame to be detected and the state of change in the detection output with the lapse of time (age) of the interference flame due to the surrounding burners. Due to, for example, clogging of the burner chip that occurs while the burner is used for a long period of time, the light amount, that is, the detection output, gradually decreases over time. In such a situation, if only the self-flame is monitored, the influence of the clogging of the burner chip and the like directly appear as a decrease in the detection output as indicated by the curve A, and the descent curve is steep. On the other hand, in the interference flame due to the surrounding burners, there is a decrease in the light amount of each burner, but it does not decrease uniformly,
The decrease in the amount of light varies and the optical interference with each other. Therefore, the decrease in the interference light as a whole is very slow as shown by the curve B.

From the above, self-flame with many fluctuation factors is detected, the threshold value and deviation are obtained from the data, and the presence or absence of the flame is judged based on it. It is better to judge the presence / absence of flame based on the detection accuracy.

FIG. 20 is an explanatory diagram showing a state in which the characteristic value and the current value obtained by the curves A and B in FIG. 19 are monitored. As shown in the figure, it is divided into 1 to 6 channels and displayed, level C in the figure is the maximum value of the calculated interference values, level D is the minimum value of the interference values, and level E is the average value of the interference values. And the level F indicates the current value.

Then, if the current value (level F) exceeds the maximum interference value (level C), it is determined to be ignition, and if it is less than that, it is determined to be extinguishing.

Even when the light quantity of the interference flame is used as a determination reference signal, data is collected in advance, the maximum value, the minimum value, and the average value of the interference value are obtained by self-learning and stored in the storage unit. The interference light level (current value) that is read out and is currently detected may be calculated.

In this flame detecting device, the shape of the flame varies depending on, for example, the type of fuel, the difference in fuel conditions such as the amount of air / fuel, the state of load, the position of the burner to be monitored in the furnace. Furthermore, for maintenance inspection of the flame detector, pull it out once for maintenance inspection, and if you install the flame detector after that, the angle of the flame detector facing the burner (flame) may differ, so each channel Weighting for determination is made in advance for each burner (flame) situation.

And after making a decision of ignition or extinguishing on each channel,
The system is used to comprehensively judge the presence / absence of a flame by adopting judgments up to the place where the weighting is in descending order.

The flame detection device according to the present invention can be used not only for determining the presence or absence of the flame as described above, but also for monitoring the relationship between the operating condition of the boiler and the burner combustion state.

〔The invention's effect〕

According to the present invention, it is possible to reliably detect the presence or absence of a flame even when operating conditions such as low NOx combustion, fuel type, and DSS operation change, and it is possible to obtain a flame detection device with high detection accuracy.

[Brief description of drawings]

1 to 20 are for explaining a flame detection device according to an embodiment of the present invention. FIG. 1 is a schematic configuration diagram of the flame detection device, and FIG. 2 is flame detection in a large boiler device. FIG. 3 is a partial cross-sectional view showing the arrangement of the device, FIG. 3 is a cross-sectional view of a main part of the flame detector, and FIGS. 4, 5, and 6 are side views, front views and rear views of the lighting head, and FIG. The figure is the fourth
Sectional view on the line XX, Figures 8 and 9 are cut-away side and front views of the protective member, Figure 10 is an enlarged sectional view of the optical fiber for relay, and Figure 11 is a partially enlarged view of the protective pipe. Sectional view, Fig. 12 is an enlarged sectional view showing the facing condition of the optical fiber for light collection, the optical fiber for relay and the optical fiber for wiring, and Figs. 13 and 14 are plan views and a partial cross section of the photoelectric converter. FIG. 15 is a side view of FIG. 15, FIG. 15 is a wavelength characteristic diagram of a silicon photodiode, FIG. 16 is a wavelength characteristic diagram of a photoconductor made of lead sulfide, and FIG. 17 is a detection angle of a flame detector with respect to a burner and a flame detection output. Characteristic diagram showing the relationship, No. 18
Figure is a characteristic diagram showing the relationship between the direction of the interference flame and the maximum value of the interference output, FIG. 19 is a characteristic diagram showing the change in the detection output with the passage of time of the self flame and the interference flame, FIG. 20 is of the present invention Explanatory diagram showing the state of monitoring the calculated characteristic value and the current value in the flame detection device, FIG. 21 is a schematic configuration diagram of a conventional flame detection device, FIG. 22 and FIG. 23 shows the detection state of the presence or absence of flame It is an explanatory view shown. 1 ... Flame detector, 20 ... Lighting head, 49 ... Photoelectric converter, 61 ... Judgment section, 65 ... Output section, B ... Interference flame light intensity.

Claims (6)

[Claims] 1. Comparing a daylighting head, a photoelectric converter for converting an optical signal detected from the daylighting head into an electric signal, and a signal detected by the daylighting head and a preset judgment reference signal. Then, in the flame detection device including a determination unit that determines the presence / absence of flame in the burner, and an output unit that outputs a signal based on the determination result in the determination unit, one burner is provided in the lighting head. On the other hand, a plurality of flame detection means having different detection modes are provided, and the determination unit weights the determination for each of the plurality of flame detection means to determine the presence / absence of a flame in the burner. A flame detection device. 2. In the claim (1),
A flame detection device characterized in that the flame detection means having different detection modes is configured by changing the viewing angle of the flame detection means with respect to the burner. 3. In the claim (1),
A flame detection device, wherein the flame detection means having different detection modes is configured by changing absorption wavelength regions for flames of the flame detection means. 4. In the claim (1),
The flame detection device having different detection modes is configured by changing the viewing angle of the flame detection device with respect to the burner and the absorption wavelength region of the flame of the flame detection device with respect to the flame. 5. In the claim (1),
The flame detection device, wherein the determination reference signal of the determination unit is determined according to the light amount of the interference flame. 6. In the claim (1),
A flame detection device, wherein a burner in which a flame forming region of the burner is not uniform in a circumferential direction is used.