JP2022018136A - Status display device for flame sensor - Google Patents

Abstract

To provide a status display device for a flame sensor that easily enables visual recognition of a status of a flame sensor without using a measuring instrument or the like by stepwisely setting multiple threshold values with respect to the output values of the flame sensor, and lighting and displaying an LED or the like in a lighting pattern according to the threshold value which the output value of the flame sensor exceeds.SOLUTION: A status display device for a flame sensor is provided with: a flame sensor 10 that detects a flame of a combustion device 2 and outputs an output voltage correlated with an ignition status; and an LED 18 that stepwisely sets at least two threshold values with respect to an output voltage VS from the flame sensor 10 and displays by lighting and blinking according to the exceeded threshold value when the output voltage VS exceeds the set threshold value.SELECTED DRAWING: Figure 2

Description

The technique disclosed in the present application relates to a state display device of a flame sensor used in a combustion control device for controlling ignition, extinguishing, etc. of a combustion means.

Conventionally, a combustion control device includes a flame detection device that detects the ignition state of a combustion means, for example, a burner or the like with a flame sensor, and outputs a flame detection signal to the combustion control device from a detection signal output from the flame sensor. Based on the flame detection signal from this flame detection device, the combustion control device controls ignition, fuel supply charge, fire extinguishing, etc., and controls the temperature of the target load. However, if the flame detection circuit or the flame sensor fails during combustion, dangerous combustion continues. Therefore, a method for detecting an abnormality in the flame detection circuit is disclosed in Patent Document 1 and the like.

In Patent Document 1, the flame of the burning means is detected by the flame sensor, a flame detection signal proportional to the ignition state is output to the flame detection circuit, and the flame detection potential output from the flame detection circuit is output during the combustion sequence. It consists of a flame detection potential monitoring means to monitor and an abnormality judgment means for judging the flame detection potential by the preset upper limit judgment potential and lower limit judgment potential, and the flame detection potential is based on the potential range between the upper limit judgment potential and the lower limit judgment potential. Disclosed is an abnormality detection device of a flame detection circuit that outputs a determination pulse signal indicating the occurrence of a failure (of the flame detection circuit) to the controller when the deviation occurs.

Japanese Unexamined Patent Publication No. 63-156921

Since the flame sensor is constantly exposed to combustion, it easily deteriorates and requires regular maintenance such as replacement. Deviations from the potential range between the upper limit determination potential and the lower limit determination potential of the flame detection potential also occur due to accidental incident of external light (other than the flame of combustion), miswiring of the flame detection circuit, etc., but mainly the flame sensor. It is caused by deterioration and failure (such as short circuit). In the method disclosed in Patent Document 1, the combustion sequence can be stopped by the signal indicating the occurrence of failure of the flame detection circuit, and the continuation of dangerous combustion can be suppressed, but the deterioration or failure of the flame sensor is not detected in advance. Therefore, there is a risk of temporary exposure to dangerous combustion conditions. Further, in order to detect deterioration or failure of the flame sensor in advance, it is conceivable to carry out periodic inspections using, for example, a measuring instrument, but such inspections are very complicated.

The technique disclosed in the present application has been proposed in view of the above problems, and a plurality of thresholds are set stepwise with respect to the output voltage of the flame sensor, and the output voltage of the flame sensor corresponds to the excess threshold. It is an object of the present invention to provide a flame sensor status display device that makes it possible to easily visually recognize the status of a flame sensor without using a measuring instrument or the like by lighting and displaying an LED or the like in a lighting pattern.

In order to achieve the above object, the state display device of the flame sensor according to claim 1 is based on a flame sensor that detects the flame of the combustion means and outputs an output voltage correlated with the ignition state, and an output voltage from the flame sensor. It is a state display device of a flame sensor provided with a display means for lighting and displaying, and the display means sets at least two or more thresholds in advance for the output voltage from the flame sensor in a stepwise manner, and sets each of the thresholds in advance. A different lighting pattern is set in advance for each threshold, and when the output voltage exceeds one threshold of the set threshold, the lighting is displayed with the lighting pattern set for the exceeded one threshold.

The flame sensor status display device according to claim 2 is the flame sensor status display device according to claim 1, and at least two or more thresholds set stepwise are flames when the combustion means extinguishes a fire. At least two or more thresholds set stepwise between the upper limit voltage and the lower limit voltage of the output voltage output by the sensor, and the upper limit voltage and the lower limit voltage of the output voltage output by the flame sensor when the combustion means is burning. It is characterized by having at least two or more thresholds set stepwise between the two.

The state display device for the flame sensor according to claim 3 is the state display device for the flame sensor according to claim 1 or 2, and the display means is a light emitting element.

The flame sensor status display device according to claim 4 is the flame sensor status display device according to claim 3, wherein the display means has at least a plurality of colors having an LED that emits green light and an LED that emits red light. It is characterized by being a light emitting element capable of emitting the light of.

In the state display device of the flame sensor according to claim 1, at least two or more threshold values are set stepwise with respect to the output potential of the flame sensor, and the lighting pattern set for each exceeding threshold value is displayed by the display means. Therefore, it becomes possible to visually grasp the state of the flame sensor without using a measuring instrument or the like. For this reason, deterioration of the flame sensor and failure (such as a short circuit) can be easily detected, so maintenance such as replacement of the flame sensor can be performed appropriately, and there is a danger caused by deterioration or failure of the flame sensor. It is possible to prevent the continuation of heavy combustion.

In the state display device of the flame sensor according to claim 2, deterioration or failure of the flame sensor can be detected not only from the output potential of the flame detection sensor at the time of combustion but also from the output potential of the flame sensor at the time of extinguishing the fire. Therefore, if two or more threshold values are set stepwise during combustion and two or more threshold values are set stepwise even during fire extinguishing so that the state of the flame sensor can be grasped by the display means. Deterioration or failure of the flame sensor can be recognized more reliably. As a result, maintenance such as replacement of the flame sensor can be performed more efficiently.

In the state display device of the flame sensor according to claim 3, by adopting a light emitting element such as an LED as the display means, the state of the flame sensor can be visually recognized with a simple configuration. Therefore, the state of the flame sensor can be displayed at low cost.

The state display device for the flame sensor according to claim 4 can visually grasp the state of the flame sensor more easily by, for example, emitting red light when burning and emitting green light when extinguishing a fire.

It is a block diagram of the combustion control device including the state display device of the flame sensor which is one Embodiment which concerns on this invention. It is a table which shows the relationship between FLAME voltage, SEN signal and LED display.

First, the combustion control device 1 including the state display device of the flame sensor according to the embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a combustion control device 1 and a combustion device 2 connected to the combustion control device 1 according to the embodiment of the present invention. The combustion control device 1 controls the combustion device 2 regarding ignition, fuel supply charge, fire extinguishing, etc., and controls the temperature of the target load in the combustion device 2.

As shown in FIG. 1, the combustion control device 1 includes a sensor circuit 5 including a flame sensor 10 and a filter circuit 11, and a control main body 3 connected to the sensor circuit 5 via a cable 12. Then, in the combustion control device 1, the portion surrounded by the broken line from the sensor circuit 5 to the LED 18 which is the display means of the present invention is the state display of the flame sensor which is one embodiment of the state display device of the flame sensor according to the present invention. Circuit 4

A CdS cell may be used for the flame sensor 10, but in recent years, the use of Cd (cadmium) has been restricted by chemical substance regulations such as the RoHS (Restriction of Hazardous Substances) directive. In the embodiment, a photodiode which is a semiconductor light receiving element is adopted.

The flame sensor 10 is installed in the combustion device 2 because it detects the combustion / extinguishing of the combustion device 2. Therefore, as described above, the sensor circuit 5 (including the flame sensor 10) and the control main body 3 of the combustion control device 1 are connected via the cable 12. Further, in the sensor circuit 5, a filter circuit 11 is connected between the flame sensor 10 and the cable 12 in order to remove noise superimposed on the cable 12. In the present embodiment, the filter circuit 11 incorporates a low-pass filter circuit composed of a resistor, a capacitor, or the like (not shown) in order to remove high-frequency noise superimposed on the cable 12.

The output current from the flame sensor 10 is converted into a voltage by the pull-up resistance R1 and the input resistance R2 of the control main body 3, and is input to the comparator 14 and the operating amplifier 15 as the output potential VS.

The ignition determination potential 13 outputs a reference potential VR for determining that the combustion device 2 has ignited. The reference potential VR output from the ignition determination potential 13 and the output potential VS of the flame sensor 10 are input to the comparator 14, the reference potential VR and the output potential VS of the flame sensor 10 are compared by the comparator 14, and the output of the comparator 14 is compared. The pull-up resistor R3 and the diode D1 connected to the control control the HIGH level signal (VCC) when the combustion device 2 is in the combustion state, and control the LOW level signal (0V) when the combustion device 2 is in the fire extinguishing state. It is designed to be input to the circuit 16. Further, the output of the comparator 14 is also input to the controller 17 via the input resistor R4. As a result, the information of the HIGH level signal / LOW level signal input to the control circuit 16 is also input to the controller 17. The controller 17 includes a CPU (not shown), a memory, and the like, and performs arithmetic processing by a program stored in the memory.

The control circuit 16 is a combustion device 2 from a HIGH level signal (VCC) / LOW level signal (0V) (hereinafter referred to as “SEN signal”) input from the comparator 14 and an input signal input from the controller 17. A signal for controlling an electromagnetic valve (not shown) is output to the combustion device 2.

On the other hand, the output potential VS of the flame sensor 10 input to the operating amplifier 15 is impedance-converted by the operating amplifier 15 and input to the controller 17. Here, the impedance conversion of the output potential VS by the operating amplifier 15 is intended to suppress the influence on the output potential VS and the comparator 14 even if the CPU in the controller 17 malfunctions. The output potential VS of the flame sensor 10 input to the controller 17 (hereinafter, this is referred to as “FLAME voltage”) is converted into a digital signal by an A / D converter (not shown) in the controller 17, and arithmetic processing is performed in the controller 17. Then, the LED 18 connected to the controller 17 is controlled to be turned on / off. In the present embodiment, the LED 18 employs a two-color LED of an LED (LD1) that emits green light and an LED (LD2) that emits red light. As a result, the LED 18 can emit three colors of light: green light, red light, and orange light (blue and red are lit at the same time). Here, as described above, in the combustion controller 1, the circuit from the sensor circuit 5 to the LED 18 which is the display means of the present invention is the state display circuit 4 of the flame sensor according to the present invention, and as described below. The operator uses a measuring instrument to determine the state of the flame sensor 10 (that is, whether it is normal or whether it has deteriorated or failed) by calculating the FLAME voltage with the controller 17 and controlling the lighting / extinguishing of the LED 18. Since it can be confirmed without any problem, deterioration or failure of the flame sensor 10 can be easily found.

Next, a method of displaying the LED 18 in the state display circuit 4 of the flame sensor will be described. FIG. 2 is a table showing the relationship between the FLAME voltage, the SEN signal, and the lighting display of the LED 18 (column of “LED display” in the figure).

As shown in FIG. 2, in the controller 17, 4.19V, 3.80V, 3.65V, 3.50V and 3 are previously applied to the FLAME voltage (output potential of the flame sensor 10 input to the controller 17). Five thresholds of .15V are set in stages. When the FLAME voltage exceeds these stepwise set thresholds during fire extinguishing and burning, the LED 18 is lit or (at predetermined intervals) in the color of light set as shown in the "LED Display" column of FIG. It is designed to blink.

First, a case where the flame sensor 10 is normal will be described. In this case, if the combustion device 2 is in a fire extinguishing state, the FLAME voltage (output potential of the flame sensor 10 input to the controller 17) is in the range of 4.50 V to 4.19 V (which is the power supply voltage VCS of the control main body 3). Is maintained at. Further, when the combustion device 2 is in the combustion state, the FLAME voltage is maintained in the range of 3.15V to 0V. When the combustion device 2 is in the fire extinguishing state, the SEN signal (HIGH level signal (VCC) / LOW level signal (0V)) output from the comparator 14 outputs the LOW level signal, and the combustion device 2 is in the combustion state. If so, the SEN signal outputs a HIGH level signal. In such a case, as shown in the column of "LED display" in FIG. 2, if the combustion device 2 is in the fire extinguishing state, the LED 18 lights green light (always on), and the combustion device 2 is in the combustion state. For example, the LED 18 lights orange light (always on).

If the flame sensor 10 is exposed to combustion for a long time and deteriorates, or if a failure such as a short circuit occurs, the FLAME voltage deviates from the above-mentioned normal range. For example, when the combustion device 2 is in a fire extinguishing state, the FLAME voltage may drop beyond the lower limit of the normal range of 4.19V. In this case, according to the "LED display" column on the left side of FIG. 2, when the FLAME voltage drops above 4.19 V, the LED 18 blinks at 1 second intervals with a DUTY ratio of 75% while remaining green light. Then, when it descends above 3.80V, it blinks at 1-second intervals with a DUTY (duty) ratio of 30%, and when it descends above 3.65V, it remains green. As it is, the controller 17 is set to blink at 0.5 second intervals with a DUTY ratio of 50%. When the FLAME voltage drops by more than 3.50V, the SEN signal changes from the LOW level signal to the HIGH level signal according to the "SEN signal" column in the center of FIG. 2, and is instructed by the program incorporated in the controller 17. From the discrepancy with the control signal (in this case, the "fire extinguishing signal"), the controller 17 detects the abnormality of the flame sensor 10, for example, the LED 18 is turned on with a red light to display the abnormality of the flame sensor 10. You may do it. Further, in the flame sensor 10 adopted in the present embodiment, when the flame sensor 10 is short-circuited while the combustion device 2 is in a fire extinguishing state, the FLAME voltage becomes 0.5 V or less. Therefore, 0.5 V is added to the threshold value to obtain the FLAME voltage. When the voltage is 0.5 V or less, the LED 18 may be turned on and displayed in a lighting pattern different from the above. In this case, a short circuit of the flame sensor 10 can also be detected.

On the other hand, the same applies to the case where the combustion device 2 is in a combustion state, and the FLAME voltage may rise beyond the upper limit of the normal range of 3.15 V due to deterioration or failure of the flame sensor 10. In this case, according to the "LED display" column on the right side of FIG. 2, when the FLAME voltage rises above 3.15 V, the LED 18 blinks at 1-second intervals with a DUTY (duty) ratio of 75% while remaining orange light. Then, when it rises above 3.50V, it blinks at 1-second intervals with a DUTY (duty) ratio of 30%, and when it rises above 3.65V, it remains orange light. As it is, the controller 17 is set to blink at 0.5 second intervals with a DUTY ratio of 50%. When the FLAME voltage rises above 3.80 V, the SEN signal changes from a HIGH level signal to a LOW level signal according to the "SEN signal" column in the center of FIG. 2, and is instructed by a program incorporated in the controller 17. From the discrepancy with the control signal (in this case, the "combustion signal"), the controller 17 detects an abnormality in the flame sensor 10, for example, stops the combustion of the combustion device 2, and the LED 18 emits red light as in the case of extinguishing the fire. It may be turned on to display the abnormality of the flame sensor 10.

As shown in FIG. 2 and above, the SEN signal has a hysteresis between 3.50V and 3.80V, which suppresses chattering of the SEN signal.

As described above, in the state display circuit 4 of the flame sensor according to the present invention, in the controller 17, for example, 4.19V, 3.80V, 3.65V, 3.50V and 3.15V as described above. Five threshold values are set in stages, and when the FLAME voltage exceeds each threshold value, the LED 18 is lit and displayed with a preset display pattern for the exceeded threshold value. Therefore, the LED 18 measures which stage of the threshold value is exceeded. Can be visually recognized without using. Therefore, by simply discovering the deterioration or failure of the flame sensor 10 and performing maintenance such as replacement, it is possible to prevent the continuation of dangerous combustion due to the failure of the flame sensor 10 in advance. ..

Here, the state display circuit 4 of the flame sensor is an example of the state display device of the flame sensor, the combustion device 2 is an example of the combustion means, the flame sensor 10 is an example of the flame sensor, and the threshold value is 4.19V, 3 .80V, 3.65V, 3.50V and 3.15V are examples of at least two or more thresholds set in stages, and LED 18 is an example of display means.

Although the embodiments of the present invention have been described in detail above, these are merely examples, and the present invention is not to be interpreted in a limited manner by the specific description in the embodiment, and those skilled in the art are skilled in the art. It can be carried out in an embodiment in which various changes, modifications, improvements, etc. are added based on knowledge, and all of them are within the scope of the present invention as long as such embodiments do not deviate from the gist of the present invention. It should be understood that it is contained in.

For example, in the above embodiment, the LED 18 adopts a two-color LED, but the display means is not limited to this, and a single LED that emits monochromatic light can also be adopted, and red and yellow. And a blue three-color LED may be adopted to display light emission in multiple colors.

Further, in the above embodiment, the status display of the flame sensor 10 is visually distinguished by blinking the LED 18 at different DUTY (duty) ratios, but the display method is not limited to this. do not have. For example, the brightness of the LED (LD1) that emits green light and / or the LED (LD2) that emits red light may be changed according to the threshold level, and the state of the flame sensor 10 may be displayed by the color tone. ..

Further, in the above embodiment, five threshold values of 4.19V, 3.80V, 3.65V, 3.50V and 3.15V are set stepwise, and the threshold value is the specification of the flame sensor used. It is not limited to these five threshold values, and the number of threshold values should be set at least two or more according to the specifications of the flame sensor using the number of threshold values. Just do it.

Further, in the above embodiment, when the combustion device 2 is in the fire extinguishing state, the FLAME voltage, which is the output voltage of the flame sensor 10, is in the range of 4.50V to 4.19V (which is the power supply voltage VCS of the control main body 3). When the combustion device 2 is in the combustion state, the FLAME voltage, which is the output voltage of the flame sensor 10, is in the range of 3.15V to 0V, but depending on the flame sensor, the output of the flame sensor is in the combustion device 2 in the fire extinguishing state. The voltage may be in the vicinity of 0 V, or the output voltage of the flame sensor in the combustion state may be in the vicinity of VCS (4.5 V), which is the opposite of the output voltage of the above embodiment. In such a case, the threshold value and the lighting pattern of the LED 18 (including the emitted color) may be set in the reverse order of the above embodiment.

1 ・ ・ Combustion control device 2 ・ ・ Combustion device 3 ・ ・ Control body 4 ・ ・ Flame sensor status display circuit 5 ・ ・ Sensor circuit 10 ・ ・ Flame sensor 11 ・ ・ Filter circuit 12 ・ ・ Cable 13 ・ ・ Ignition judgment Potential 14 ... Comparator 15 ... Operating amplifier 16 ... Control circuit 17 ... Controller 18 ... LED

Claims (4)

A flame sensor that detects the flame of the combustion means and outputs an output voltage that correlates with the ignition state,
It is a state display device of a flame sensor provided with a display means for lighting and displaying based on the output voltage from the flame sensor.
The display means presets at least two or more threshold values in a stepwise manner with respect to the output voltage from the flame sensor, and presets different lighting patterns for each of the threshold values.
A state display device for a flame sensor, characterized in that when the output voltage exceeds one threshold value set, the lighting is displayed in the lighting pattern set for the one threshold value exceeded. The at least two or more threshold values set stepwise are at least two or more set stepwise between the upper limit voltage and the lower limit voltage of the output voltage output by the flame sensor when the combustion means extinguishes a fire. Threshold and
The first aspect of the present invention, wherein the combustion means has at least two or more threshold values set stepwise between the upper limit voltage and the lower limit voltage of the output voltage output by the flame sensor at the time of combustion. Flame sensor status display device. The state display device for a flame sensor according to claim 1 or 2, wherein the display means is a light emitting element. The state display device for a flame sensor according to claim 3, wherein the display means is a light emitting element capable of emitting light of a plurality of colors having at least an LED that emits green light and an LED that emits red light.

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