JPH06101835A - Flame detecting device - Google Patents

Abstract

PURPOSE:To detect a short between a flame rod and a burner unit and an abnormality such as oxygen deficiency, lift combustion and the like by checking a detected condition of a flame rod every point of time that a specified amount of oil having a possibility of oxygen deficiency is caused to burn. CONSTITUTION:When the amount of fed oil counted at a fed oil judging unit 15 reaches a specified level, a detection range switchover unit 18 switches over from a judging range to a short detection range in a flame condition judging unit 17. At the same time, a timer unit 20 operates to begin clocking, and when a time period clocked reaches a set time period, the flame condition judging unit 17 checks a flame current input from a flame detection unit 16 to suspend combustion when the frame current reaches an abnormal level due to beginning of lift combustion or oxygen deficiency. When the elapsed time does not reach a set level, combustion is suspended for the reason that a flame current input from the flame detection unit 16 is not detected by the flame condition judging unit 17 with respect to ignition or reaches an abnormal level of short detection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame detection device for combustion equipment.

[0002]

2. Description of the Related Art Conventionally, as a flame detecting device for monitoring the presence or absence of ignition and the state of flame, an AC voltage or a DC voltage is applied between a flame rod and a burner portion, and a rectification action by an ion current of the flame is utilized. It is generally used to detect the combustion state.

For example, FIG. 3 shows a burner unit of a combustion device. Combustion gas is ejected from a flame port 2 of a burner portion 1 and is ignited by a spark of an ignition electrode 3 to form a combustion flame 4. As a flame detection device, as shown in FIG. 4, a voltage is applied between the flame rod 5 installed in the combustion flame 4 and the burner unit 1, and the combustion flame 4 flows using the rectification phenomenon of the combustion flame 4. A current value (hereinafter referred to as a frame current) is detected, and the flame state determination means 6 confirms the presence or absence of flame.

When the combustion state is abnormal, the flame state determining means 6 detects the abnormal combustion by monitoring the flame current value because the flame current value decreases during lift combustion or yellow chip combustion, for example. It is designed to stop combustion. Further, since the flame current value decreases even when the amount of oxygen in the room decreases and the oxygen deficiency state starts, the combustion current is stopped when the value is monitored.

[0005]

However, in this type of flame detecting device, the flame rod 5 and the burner portion 1 are short-circuited due to the adhesion of tar due to abnormal combustion, thermal deformation of the flame rod 5, and the like. May be. In such a case, not only abnormal combustion such as lift combustion and yellow chip combustion, but also when the oxygen deficiency state is extremely dangerous for the human body, the flame current value does not drop to the abnormality detection level and cannot be detected. There was a problem.

The present invention has been made in view of the above points, and aims to improve safety.

[0007]

In order to achieve the above object, the present invention has a combustion amount determining section for determining a combustion amount based on signals from a temperature setting switch and a room temperature sensor, and a combustion determined by the combustion amount determining section. A combustion control unit that controls combustion by an amount, an electromagnetic pump that is driven by an output from the combustion control unit, a burner unit that performs combustion by driving the electromagnetic pump, and a pulse signal transmitted for driving the electromagnetic pump. An oil feed amount determination unit that counts and measures the amount of oil fed to the burner unit, a frame rod for detecting the flame state of the burner unit, and a frame current flowing between the frame rod and the burner unit. And a flame detection unit that outputs a flame detection signal, and a flame state determination that outputs a combustion stop signal when the flame detection signal from the flame detection unit reaches a preset abnormal level And a detection range switching unit that switches the determination range of the flame state determination unit to the short-circuit detection range for a predetermined time when the oil delivery amount output from the oil delivery amount determination unit reaches a preset oil delivery amount. It is provided as a configuration.

[0008]

With the above structure, the present invention switches the flame current abnormality detection range to the short circuit detection range and detects a short circuit between the frame rod and the burner section at each time when a predetermined amount of oil that easily causes oxygen deficiency is burned. Therefore, it is possible to surely detect an abnormality such as oxygen deficiency or lift combustion, as well as a short abnormality, and safety is improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, 7 is a room temperature sensor such as a thermistor for detecting the room temperature, 8 is a temperature setting switch for setting a desired temperature for the combustion equipment, and 9 is input information of the room temperature sensor 7 and information of the temperature setting switch 8. A combustion amount determining unit 10 that determines the combustion amount is a combustion control unit that inputs the combustion amount information from the combustion amount determining unit 9 and controls the combustion load group 11 to control the combustion of the burner unit 1.
As the combustion load group 11, an electromagnetic pump 12 that operates a plunger by a pulse signal to send oil for combustion,
It comprises a burner motor 13 for blowing combustion air, an igniter 14 for igniting a flame, and the like.

Reference numeral 15 denotes an electromagnetic pump 12 from the combustion control unit 10.
To a burner unit 1 for detecting the amount of oil sent to the burner unit 1, 16 is a flame detection unit for detecting a flame current flowing between the flame rod 5 and the burner unit 1, Reference numeral 17 is a flame state determination unit for instructing to stop combustion when the flame current from the flame detection unit 16 reaches a predetermined abnormality detection level, 18 is a detection range switching unit, and the amount of oil fed from the oil feed amount determination unit 15 is When the output reaches a predetermined specific oil feed amount, the abnormality determination range of the flame state determination unit 17 is switched to the short detection range and the timer unit 20 is driven.

The detection range switching unit 18 has a changeover switch unit 19 (see FIG. 4) composed of a transistor or the like. When the timer unit 20 measures a predetermined time, the output is received and the switch unit 19 is restored. The state, that is, the determination range of the flame state determination unit 17 is returned to the original state.

Next, the operation of the control unit configured as described above will be described with reference to the flowchart of FIG. When the equipment is powered on and the combustion control is started, the equipment control is started according to the procedure of the control program shown in the flowchart of FIG.

First, in step 21, the oil feed amount determination unit 1
In step 5, it is determined whether or not the electromagnetic pump 12 is driven. If it is driven, the process proceeds to step 22, the number of output pulses of the electromagnetic pump 12 is counted, and if it is not driven, the process proceeds to step 30.

In step 23, it is determined whether or not ignition has been detected by the flame state determination section 17, and if ignition has been detected, control proceeds to step 24, and if ignition has not been detected, control proceeds to step 30.

In step 24, it is judged whether or not the oil feed amount counted by the oil feed amount determination section 15 is a preset oil feed amount, and if it is the predetermined oil feed amount, the routine proceeds to step 25, where the count is made. The number of pulses is cleared, and if it is not the predetermined oil feed amount, the process proceeds to step 33.

In step 26, the detection range switching unit 1
8 switches the determination range of the flame state determination unit 17 to the short detection range.

At step 27, the timer section 20 works at the same time as the detection range is switched, and the time counting is started. Step two
At 8, it is determined whether or not the counted time has passed a preset time, and if it has passed, the process proceeds to step 34,
If it has not elapsed, the process proceeds to step 29.

In step 29, the flame state determination part 17 determines whether or not the flame current input from the flame detection part 16 is a preset short circuit detection abnormal level, and if it is the short circuit detection abnormal level, the process proceeds to step 30. , If the short circuit detection abnormal level is not reached, the process proceeds to step 36.

In step 30, the flame state determination unit 17
Since the flame current input from the flame detection unit 16 is not detected as the ignition is detected, the short-circuit detection abnormal level is detected, or the electromagnetic pump 12 is not driven, the combustion control unit is required to stop the combustion. The signal from 10 to the combustion load group 11 is turned off.

At step 31, the time count at the time of the short check is cleared, and at step 32, the count pulse number of the oil feed amount determination section 15 is cleared.

In step 33, the oil feed amount determination unit 15 has not reached the predetermined oil feed amount, so the time for the short check is cleared.

In step 34, the detection range is returned to the normal check range, and in step 35, the flame state determination part 17 determines whether the flame current input from the flame detection part 16 is at an abnormal level at the time of normal check, and lifts. If the level is abnormal due to combustion, yellow chip combustion, etc., or the amount of oxygen in the room is decreasing and the oxygen level is approaching, the process proceeds to step 30 to stop the combustion. Proceed to continue combustion.

In step 36, a signal from the combustion control unit 10 to the combustion load group 11 is turned on to operate each load in order to continue normal combustion.

During the above-described combustion operation, steps 21 to 36 are repeated to ensure safety by not only short-circuiting abnormalities but also abnormal combustion such as lift combustion and when an oxygen-deficient condition is about to occur. To do.

In this configuration, since the short check is performed when a predetermined oil is burned, if the predetermined amount of oil is set to a value at which the oxygen deficient state can occur, it is necessary to ensure that the oxygen deficient state easily occurs. Checking for short circuit abnormality improves the reliability of oxygen deficiency detection.

Therefore, the abnormality of oxygen deficiency cannot be confirmed due to the abnormality of the short circuit, and the safety of the combustion equipment is greatly improved.

The above embodiment is shown as an example of the present invention, and may have any configuration as long as it achieves the objects and effects of the present invention. For example, the control means is a microcomputer. However, it is also possible to use a circuit configuration capable of performing the same control as this, even if a microcomputer is not used.

Further, the amount of oil fed is measured by counting the pulse signals supplied to the electromagnetic pump. However, when an oil feeding method other than the electromagnetic pump is used, the oil feeding means is used as a means for measuring the amount of oil fed. The amount of residual oil in the tank may be measured, or a sensor or the like for measuring the amount of oil flowing from the pump to the burner in the oil supply pipe may be installed to measure the amount.

[0029]

As is apparent from the description of the embodiment, the present invention has no abnormality in the detection state of the frame rod at each time when a predetermined amount of oil that may cause oxygen deficiency is burned. In order to confirm that, it is possible not only to detect a short circuit between the frame rod and the burner portion, but also to reliably detect an abnormality such as oxygen deficiency or lift combustion, which greatly improves safety.

[Brief description of drawings]

FIG. 1 is a block diagram of a flame detection device according to an embodiment of the present invention.

FIG. 2 is a flowchart of the flame detection device.

FIG. 3 is a front view of a burner portion in the present invention and a conventional example.

FIG. 4 is a circuit diagram showing a specific example of a flame detection unit in the present invention and the conventional example.

[Explanation of symbols]

 1 Burner part 5 Frame rod 7 Room temperature sensor 8 Temperature setting switch 9 Combustion amount determination part 10 Combustion control part 12 Electromagnetic pump 15 Oil feed amount determination part 16 Flame detection part 17 Flame state determination part 18 Detection range switching part

Claims (1)

[Claims] 1. A combustion amount determination unit that determines a combustion amount based on signals from a temperature setting switch and a room temperature sensor, a combustion control unit that controls combustion according to the combustion amount determined by the combustion amount determination unit, and the combustion control. An electromagnetic pump driven by the output of the electromagnetic pump, a burner unit that burns by driving the electromagnetic pump, and a pulse signal transmitted for driving the electromagnetic pump to count the amount of oil sent to the burner unit. An oil feed amount determination unit, a frame rod for detecting a flame state of the burner unit, and a flame detection unit that inputs a frame current flowing between the frame rod and the burner unit and outputs the flame current as a flame detection signal. , A flame state determination unit that outputs a combustion stop signal when the flame detection signal from the flame detection unit reaches a preset abnormal level, and a determination range of the flame state determination unit, A flame detection device, comprising: a detection range switching unit that switches to a short-circuit detection range for a predetermined time when the oil delivery amount output from the determination unit reaches a preset oil delivery amount.