JPH0714829Y2 - Ultraviolet sensor diagnostic device for combustion equipment - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention relates to a diagnostic device for an ultraviolet sensor in a combustion device for diagnosing an ultraviolet sensor used for flame detection in a combustion device such as a gas burner.

[Prior art]

An ultraviolet sensor (hereinafter referred to as a UV sensor) is provided in the combustion device to detect the presence or absence of a burner flame. The UV sensor is configured so that the anode electrode and the cathode electrode are arranged to face each other in the case, and a drive pulse voltage is applied between these electrodes, and when ultraviolet rays are incident from a window provided in the case, both sensors are provided. It is configured to generate a discharge between the electrodes. Therefore, by disposing this UV sensor near the flame of the burner, the presence or absence of the flame can be detected by detecting the ultraviolet rays emitted from the flame. In that case, the detection output of the UV sensor when there is a flame becomes a pulse output that is synchronized with the drive pulse voltage applied between both electrodes, and the detection output when there is no flame becomes a substantially zero output. Therefore, the detection output pulse of the UV sensor is counted by the counter, and if a predetermined count is reached, it can be determined that there is a flame.

[Problems to be solved by the device]

In the above-mentioned combustion device, when an abnormality occurs in the UV sensor used for flame detection, for example, when self-discharge or noise occurs, a pulse appears in the detection output even when there is no flame, and the counter indicates this. False counting occurs due to counting. Therefore, in such a combustion device, it is necessary to diagnose whether or not the UV sensor is normal. This invention was made in view of the above situation,
It is an object of the present invention to provide a diagnostic device that can self-diagnose the state of the UV sensor by the combustion device itself.

[Means for Solving the Problems]

This invention, by performing a calculation based on the detection output of the flow sensor for detecting the fuel supplied to the burner or the control signal given from the controller to the shutoff valve for supplying the fuel to the burner and the detection output of the UV sensor, A calculation unit for diagnosing the UV sensor is provided.

[Action]

When it is determined that the flow sensor or the shutoff valve is operating normally, the detection output of the UV sensor is checked, and if the detection output shows an abnormality, it is determined that the UV sensor is out of order.

【Example】

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a burner, 2 is a flame of the burner 1, 3 is a shutoff valve for supplying gas as a fuel to the burner 1, 4 is a flow rate of a gas sensor, a flow sensor, etc. for detecting the gas supplied to the burner 1. Sensor (hereinafter referred to as gas flow sensor), UV is UV emitted from the flame 2, 5 is a UV sensor for detecting UV, FG is UV sensor detection output, SG is gas flow sensor 4 detection output, and 6 is detection An amplifier that amplifies the output SG,
7 is a controller that controls the entire combustion device while the detection outputs FG, SG, etc. are added. SC is a control signal for the controller 7 to turn on / off the shutoff valve 3. 8 is based on the detection outputs FG, SG. Calculation unit for diagnosing UV sensor 5, S
E is an abnormality detection signal of the UV sensor 5 output from the calculation unit 8. Next, the calculation process for diagnosing the UV sensor 5 in the calculation unit 8 will be described with reference to the flowchart of FIG. In FIG. 2, when the power is turned on in step ST1,
In step ST2, it is checked whether or not the signal line of the gas flow rate sensor 4 is short-circuited or open, and if it is short-circuited or open, the process of abnormal gas flow rate sensor is performed in step ST3. If the signal line is normal, the process proceeds to step ST4, and the presence or absence of the detection output SG of the gas flow rate sensor 4 is checked. If the detection output SG is present, it is checked in step ST5 whether or not the detection output SG is stable. If the detection output SG is unstable, abnormality processing of the gas flow rate sensor 4 is performed in step ST6. If the detection output SG is stable, it is determined that the gas flow rate sensor 4 is normal, and the process proceeds to step ST7.
Here, the state of the detection output FG of the UV sensor 5 is checked. Then, if the detection output FG is stable, it is determined that the UV sensor 5 is normal, and the process returns to step ST4. If the detection output FG is unstable, the VU sensor abnormality process is performed in step ST8. When it is determined in step ST4 that the detection output SG of the gas flow sensor 4 is not present, the process proceeds to step ST9. Here, the pulses of the detection output FG of the UV sensor 5 are counted. Then, in step ST4, although the detection output SG of the gas flow rate sensor 4 is not present, that is, it is determined that the gas is not supplied to the burner 1 and the flame 2 is not present, the pulse number of the detection output FG becomes abnormal. If a large number is counted, it is determined that the UV sensor 5 has an abnormality, and the abnormality processing of the UV sensor 5 is performed in step ST10, and processing such as cutting the FG line of the detection output is performed. Or, an error is output (display communication) even if the FG line is not cut. If the pulse count number is less than or equal to the predetermined value, it is determined in step ST11 that the UV sensor is normal, and the process returns to step ST4. The above steps ST8 and ST
When the abnormality processing of the UV sensor 5 is performed at 10, the calculation unit 8 outputs the abnormality detection signal SE. In the above-described embodiment, the detection output SG of the gas flow rate sensor 4 is added to the calculation unit 8 so that diagnosis is performed together with the detection output FG of the UV sensor 5, but instead of the detection output SG, the dotted line in FIG. As shown, the control signal SC from the controller 7 for operating the shutoff valve 3 may be added to the arithmetic unit 8.

[Effect of device]

According to this invention, the state of the UV sensor is diagnosed based on the detection output of the flow sensor or the control signal of the shutoff valve and the detection output of the UV sensor. The UV sensor can be self-diagnosed by the fuel device itself by effectively using the valve etc.
Further, it is possible to reliably detect the abnormality of the UV sensor, eliminate erroneous detection of the UV sensor, and improve the safety of the combustion device.

[Brief description of drawings]

FIG. 1 is a block diagram showing a diagnostic device for an ultraviolet sensor in a combustion device according to an embodiment of the present invention, and FIG. 2 is a flow chart showing a process executed by a calculation unit in the device. 1 is a burner, 2 is a flame, 3 is a shutoff valve, 4 is a gas flow sensor, 5 is a UV sensor, 7 is a controller, 8 is a calculation unit, and FG.
Is the detection output of the UV sensor, SG is the detection output of the flow sensor, SC
Is a control signal.

Claims (1)

[Scope of utility model registration request] 1. A combustion apparatus provided with a flow rate sensor for supplying fuel to a burner through a shutoff valve controlled by a controller and for detecting the fuel supplied to the burner, and an ultraviolet sensor for detecting a flame of the burner. In the combustion, characterized in that an arithmetic unit for diagnosing the state of the ultraviolet sensor based on the detection output of the flow sensor or the control signal given to the shutoff valve from the controller and the detection output of the ultraviolet sensor is provided. Ultraviolet sensor diagnostic device in equipment.