JPH0763328A - Inspecting method of sensor for burner equipped with co sensor - Google Patents

Abstract

PURPOSE:To inspect a CO sensor easily by a method wherein the rotation control of a burning fan is switched from a normal mode fan-control circuit to a number of rotation-setting circuit for inspection to effect a bad combustion. CONSTITUTION:The rotation control of a burning fan 16 is switched from a normal mode fan control circuit 21 to an inspection number of rotation setting circuit 22 under the condition of burning operation of a burning device. Then, the number of rotation of the burning fan 16 is lowered, the amount of combustion air is reduced, a malcombustion is effected and CO gas, having a concentration wherein CO-safety-operation is effected, is generated. Under this condition, when the CO-safety-operation is effected, a CO sensor 5 is judged to be abnormal, when the CO safety operation is not effected, the CO sensor 5 is judged to be abnormal, and the CO sensor 5 is inspected for the condition, whether it is good or not. According to this method, troublesome work of opening and/or closing a damper for changing the amount of combustion air becomes unnecessary and the inspection of the CO sensor 5 can be effected very easily within a short period of time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quality inspection method for a CO sensor of a combustion apparatus in which a CO sensor (carbon monoxide gas detection sensor) is installed.

[0002]

2. Description of the Related Art Combustion devices such as water heaters, bath heaters, and heaters that use gas or oil as fuel detect the CO gas concentration in the combustion exhaust gas, and the detected CO concentration exceeds a predetermined reference concentration. In some cases, a safety device is provided for issuing a warning when the engine is turned off or performing a safe operation such as shutting off the fuel supply. It goes without saying that the CO sensor is inspected before it is attached to the combustion device.
The sensor is vulnerable to vibration, and there is a problem that the CO detection performance deteriorates when a large vibration is received. Therefore, normally,
When shipping a combustion device incorporating a CO sensor, C
Even after the O sensor is inspected and the combustion device is installed and installed at the destination, the CO sensor is inspected as necessary.

A conventional example of this CO sensor inspection method is shown in FIG.
Is shown in. In this inspection method, in addition to the air amount adjustment damper 2 that variably adjusts the air amount, an inspection damper 3 that does not impair the air introduction amount during normal burner combustion is provided at the gas and air intake of the combustion device. When checking the quality of the CO sensor, in the state where the burner 1 is burned,
Inspecting operation Operate the knob 4 to open the normally closed switch 26, close the normally open switch 27 to cut off the circuit on the safety valve 7 side that shuts off the fuel gas, activate the circuit on the alarm device 6 side, and operate the switch. Move the inspection damper 3 in conjunction with the burner 1
The amount of entering air is reduced to forcibly deteriorate the combustion of the burner 1, and the CO sensor 5 detects the increase in the CO gas concentration due to the deterioration of combustion. When the detection output of the CO sensor 5 exceeds the reference level, the alarm device 6 is caused to give an alarm, and when the CO safety operation for issuing the alarm is performed, the CO sensor 5 is judged to be normal, When the CO safety operation does not operate, it is determined that the CO sensor 5 has failed.

[0004]

However, the recent combustion apparatus is different from the simple apparatus having one burner as shown in FIG. 6 in that a plurality of burners 1 are arranged next to each other. It has a configuration of burner rows.
In a combustion apparatus equipped with such a burner row, when an attempt is made to inspect a CO sensor by the same method as in the conventional example, an inspection damper 3 is provided for each burner in the burner row, and an inspection operation for driving each inspection damper is performed. Each knob has to be provided, which not only complicates the apparatus configuration, but also makes the inspection operation complicated, and it takes a lot of time to inspect the CO sensor.

As a method for solving such a problem,
For example, as shown in FIG. 5, a damper hole having a plurality of narrow openings 10 facing the air introducing port 9 on the side of the air introducing port 9 at each burner position of a burner row in which a plurality of burners 1 are arranged.
The nozzle damper 12 provided with 11 is provided, and during normal combustion operation, the large diameter hole 13 of the nozzle damper 12 is made to coincide with the air introduction port 9 of each burner, and when the CO sensor 5 is inspected, the nozzle damper 12 is Narrow opening 10
Match the side with the air inlet 9 of the burner 1 to reduce the amount of air,
It is also conceivable that the combustion state is deteriorated and the amount of CO gas generated is forcibly increased, and the quality of the CO sensor 5 is inspected depending on whether or not the CO safety operation is performed.

However, at the time of checking the quality of the CO sensor 5, the front cover of the combustion device is removed, and further,
After removing the front cover 14 of the burner, loosen the screw 15 holding the nozzle damper 12 to shift the position of the nozzle damper 12 and temporarily fix it, and then attach the front cover 14 of the burner in this state.
The sensor 5 must be inspected, and after the CO sensor 5 is inspected, the burner front cover 14 is removed again, the nozzle damper 12 is returned to its original position, and the burner front cover 14 and the front cover are attached. You will be forced to do that C
This causes a problem that it takes time to inspect the O sensor 5.

The present invention has been made in order to solve the above problems, and an object of the present invention is to reduce the CO even in a recent combustion apparatus in which a burner device having a burner row configuration in which a plurality of burners are arranged is installed. It is an object of the present invention to provide a sensor inspection method for a combustion device with a CO sensor, which can easily inspect the sensor.

[0008]

In order to achieve the above object, the present invention is constructed as follows. That is, the present invention includes a combustion fan for supplying / exhausting combustion, a CO sensor for detecting the CO concentration in the combustion exhaust gas, and a CO safety device for performing a safe operation according to the CO detected concentration of the CO sensor. In the provided combustion device with a CO sensor, in addition to the normal mode fan control circuit that controls the rotation of the combustion fan in the normal combustion operation mode, the CO safety device operates by forcing a gas of each CO concentration that deteriorates combustion. The inspection rotation speed setting circuit for the combustion fan to be generated is provided, and when the CO sensor is inspected, the combustion fan rotation control is switched from the normal mode fan control circuit to the inspection rotation speed setting circuit while the combustion device is in the combustion operation. Combustion is deteriorated, and the quality of the CO sensor is inspected depending on whether or not a safe operation of CO concentration corresponding to the deterioration of combustion is performed. It has been.

[0009]

In the present invention having the above structure, when the CO sensor is inspected, the rotation control of the combustion fan is switched from the normal mode fan control circuit to the inspection rotation speed setting circuit in the combustion operation state of the combustion device. Then, the rotation speed of the combustion fan decreases, the amount of combustion air decreases, and the combustion deteriorates.
CO gas is generated at a concentration at which CO safe operation is performed. In this state, when the safe operation corresponding to the CO concentration is performed, the CO sensor is judged to be normal without any abnormality,
When the CO safety operation does not operate, it is judged that the CO sensor is abnormal, and the quality of the CO sensor is inspected.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same parts as those in the conventional example shown in FIG. 6 and the device shown in FIG. 5 are designated by the same reference numerals, and the duplicate description thereof will be omitted.

The combustion apparatus of this embodiment is intended for a combustion apparatus in which a plurality of burners in a burner row similar to that shown in FIG. 5 are incorporated, and the burner is arranged on the lower side (upstream side) of these burner rows. A combustion fan 16 for supplying and exhausting combustion is arranged, and a CO sensor 5 for detecting the CO concentration in the combustion exhaust gas is installed on the exhaust pipe 17 side downstream of the combustion chamber.

FIG. 1 shows a schematic configuration of the first embodiment for carrying out the method of the present invention. The CO detection signal of the CO sensor 5 is added to a CO safety control circuit, and the CO safety control circuit is C
The alarm device 6 is operated when the O detection concentration reaches the reference level, and the gas safety valve 7 is shut off when the CO detection concentration further increases and reaches the dangerous level.
The combustion fan 16 is provided with a fan rotation detection sensor (Hall IC in this embodiment) 18 for detecting the fan rotation speed, and the detection signal of the fan rotation detection sensor 18 is passed through the changeover switch 20 to perform normal combustion operation. It is added to the normal mode fan control circuit 21 that controls the rotation of the combustion fan 16 in the mode.

In this embodiment, the fan rotation detection sensor 18 outputs a fan rotation detection signal as a frequency signal proportional to the fan rotation speed. The normal mode fan control circuit 21 detects the rotation speed based on the frequency of the fan rotation detection signal applied from the fan rotation detection sensor 18, and controls the drive voltage of the combustion fan so as to blow an air amount corresponding to the combustion amount of the burner.

A characteristic of this embodiment is that, in addition to the normal mode fan control circuit 21, a frequency conversion circuit 22 functioning as an inspection rotation speed setting circuit for inspecting the CO sensor 5 is provided. Is. The output side of the frequency conversion circuit 22 is connected to the normal mode fan control circuit 21, and the input side of the frequency conversion circuit 22 is connected to the normally open terminal 23 of the changeover switch 20.

The frequency conversion circuit 22 is a fan rotation detection sensor.
The frequency of the fan rotation detection signal output from 18 is converted so as to increase by a predetermined amount. By adding the frequency-converted signal to the normal mode fan control circuit 21,
The normal mode fan control circuit 21 controls the drive voltage of the combustion fan 16 so that the CO concentration is such that the CO safety operation such as the alarm of the alarm device 6 is performed.

This embodiment is constructed as described above,
Next, the operation will be described. During normal combustion operation, the changeover piece 24 of the changeover switch 20 is a normally closed terminal.
The detection signal of the combustion fan 16 connected to the 19th side and detected by the fan rotation detection sensor 18 is applied to the normal mode fan control circuit 21 and the fan rotation speed is controlled according to the combustion amount of the burner. In this normal combustion operation mode, C
When inspecting the O sensor, the changeover switch 20 is operated and the changeover piece 24 is changed over to the normally open terminal 23 side.

By switching the switch, the fan rotation detection signal of the fan rotation detection sensor 18 is converted into the frequency conversion circuit 22.
Is added to the normal mode fan control circuit 21. Normal mode fan control circuit 21 is a frequency conversion circuit
The frequency of the signal applied from 22 is detected, and it is determined that the number of revolutions of the combustion fan 16 is higher by the amount increased by the frequency conversion circuit 22. That is,
By converting the frequency to increase, the normal mode fan control circuit 21 erroneously determines that the rotation speed is higher than the actual fan rotation speed by the amount of the increased frequency, and determines the fan rotation speed. The drive voltage of the combustion fan 16 is controlled in the lowering direction. As a result, the rotation speed of the combustion fan 16 is reduced, and the amount of air blown from the combustion fan 16 is reduced. Due to this decrease in the air amount, the combustion of the burner is forcibly deteriorated, the CO gas is increased, and the CO concentration in the combustion exhaust gas is increased to the reference concentration at which the CO safe operation is performed.

When the CO sensor 5 is normal, the alarm output of the alarm device 6 is issued when the detection output of the CO sensor 5 becomes the signal level for performing the CO safety operation.

On the other hand, when an abnormality occurs in the CO sensor 5, the CO sensor 5 does not output the signal level for performing the CO safe operation, so that the CO safe operation is not performed. Therefore, the person who inspects the CO sensor 5 switches the changeover switch 20 to the frequency conversion circuit 22 side and then
The quality of the CO sensor 5 can be checked depending on whether or not the CO safety operation is activated.

According to this embodiment, the quality of the CO sensor 5 can be inspected by simply switching the changeover switch 20, so that the CO sensor 5 can be inspected by shifting the nozzle damper 12 described above. In comparison, the inspection work becomes extremely easy, and it is possible to perform the inspection work in a short time without taking time and effort.

FIG. 2 shows a second embodiment of the present invention. This embodiment does not variably control the number of revolutions of the combustion fan 16 in accordance with the combustion amount, but does not depend on the magnitude of the combustion amount and is always constant, for example, 100 V.
The drive voltage of the normal mode fan control circuit 21 is applied to the combustion fan 16 in a simple structure of the combustion device.
A circuit for checking the quality of the sensor is provided.
A resistance circuit 25 is provided as an inspection rotation speed setting circuit instead of the frequency conversion circuit 22 of the embodiment.

In this embodiment, in the normal combustion operation mode, a drive voltage of a constant voltage (100 V in this embodiment) is applied to the combustion fan 12 from the normal mode fan control circuit 21 to burn a constant amount of air. It is supplied from the fan 12 to the burner row, and the combustion operation continues. When the CO sensor 5 is inspected in this combustion mode, the switching piece 24 of the switching switch 20 is switched to the normally open terminal 23 side.
Then, the fan drive voltage of 100 V output from the normal mode fan control circuit 21 is dropped when passing through the resistance circuit 25, and a voltage lower than the drive voltage for normal operation is applied to the combustion fan 16.

Due to the decrease in the fan drive voltage, the number of rotations of the fan is decreased and the amount of blown air is decreased.
The CO gas concentration in the exhaust gas increases as in the example of
The CO safety device has a standard level of CO concentration at which CO safe operation is performed. When the CO sensor 5 is normal, the CO safe operation is performed, and when there is an abnormality such as a malfunction of the CO sensor 5, the safe operation is not performed. Is possible. Also in this embodiment, since the CO sensor 5 can be inspected only by switching the changeover switch 20, the inspection work becomes very easy.

The present invention is not limited to the above-mentioned embodiments, but can be embodied in various embodiments. For example, in each of the above-described embodiments, when the changeover switch 20 is changed over to the normally open terminal 23 side, the alarm device 6 gives an alarm C.
Although the number of revolutions of the combustion fan 16 is set so as to attain the O gas concentration, unlike this, for example, when the CO gas concentration reaches the first level, the alarm device 6 gives an alarm.
When the CO gas concentration further increases to the second level, the safety valve 7 is shut off, or CO
When the gas concentration reaches the first level, the rotation speed of the combustion fan 16 is increased, and when the gas concentration reaches the second level with a higher CO concentration, the alarm device 6 is operated to further increase the CO concentration. The safety valve 7 may be shut off when it reaches the third level, so that the safety operation check may be performed at each of two or more levels of CO gas concentration.

In such a case, as shown in FIGS. 3 and 4, the normally open terminals of the changeover switch 20 are provided in the number corresponding to the level at which the safe operation is performed,
Select the changeover switch 20, for example, a normally open terminal.
The rotation speed of the combustion fan 16 is configured to be switched so that the CO concentration, which is a safe operation of each level concentration, is generated by switching to the 23a, 23b side stepwise, and the changeover switch 20 is stepwise changed. By switching, the safe operation according to each level of the CO concentration may be performed, whereby the operating states of the CO sensor 5 and the safe operation circuit may be inspected together.

Further, as another inspection method of the CO sensor 5, the C of each inspection concentration is set in the normal mode fan control circuit 21.
The rotation speed of the combustion fan 16 that generates O 2 gas may be given in advance, for example, as table data (matrix data). Generally, in the normal mode fan control circuit 21, in order to supply an air amount commensurate with the combustion amount, the relationship between the combustion amount (for example, the supply pressure of the fuel gas) of the fan speed is given as table data, The normal mode fan control circuit 21 obtains information on the combustion amount, that is, the gas supply pressure, and every time this gas pressure changes, the fan rotation speed corresponding to the changed gas pressure is read from the table data and burned. The rotation of the fan 16 is controlled.

In the normal mode fan control circuit 21, the fan rotation speed for further generating the CO gas at the inspection concentration is given as a table data of the gas pressure at each inspection CO concentration and the fan rotation speed, and the changeover switch is normally set. By switching from the combustion operation mode to the inspection mode of the CO sensor and specifying the inspection CO concentration, the fan rotation speed is read from the specified CO concentration (gas pressure) in the table data so that the fan rotation speed is obtained. By applying a driving voltage to the combustion fan 16, it is possible to create a combustion state in which CO gas of each inspection CO concentration is generated, and as a result, the quality of the CO sensor 5 can be inspected as in the above embodiment. In this case, the fan rotation speed table data as the inspection density and this data processing unit function as an inspection rotation speed setting circuit.

Further, in each of the above-mentioned embodiments, the hot water supply device has been described as the combustion device. However, the present invention uses a bath kettle that uses gas or oil as a fuel, a heater, an oil fan heater, an oil FF heater, and heavy oil. C of various types of combustion devices that perform burner combustion using air from a combustion fan such as a boiler
It is applied to the O sensor inspection method.

In the present invention, after the combustion operation, the normal fan mode control is switched to the inspection rotation speed setting circuit, but the inspection rotation speed setting circuit may be used from the initial stage.

In the case where the fan rotation detection sensor is not provided and the air flow rate is estimated and controlled by the power consumption of the fan, the CO sensor may be inspected by controlling the power consumption of the fan.

In the present invention, the combustion fan is provided on the lower side of the burner row, but the combustion fan may be provided on the upper side (exhaust side) of the burner row.

[0032]

According to the present invention, when checking the quality of the CO sensor, it is sufficient to simply switch the combustion fan rotation control circuit from the normal mode fan control circuit to the check rotation speed setting circuit. Since the complicated work of opening and closing the damper for changing the amount is released, it is possible to perform the quality inspection of the CO sensor extremely easily and in a short time.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a first embodiment for carrying out the method of the present invention.

FIG. 2 is a structural explanatory view showing a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of still another embodiment provided with a frequency conversion circuit.

FIG. 4 is an explanatory view of still another embodiment corresponding to FIG.

FIG. 5 is an explanatory view showing the structure of a recent hot water heater generally known as a combustion device.

FIG. 6 is an explanatory diagram showing a method for inspecting a CO sensor in a conventional combustion apparatus with a CO sensor.

[Explanation of symbols]

 1 Burner 5 CO sensor 16 Combustion fan 18 Fan rotation detection sensor 20 Changeover switch 21 Normal mode fan control circuit 22 Frequency conversion circuit

Claims (1)

[Claims] 1. A combustion fan for supplying / exhausting combustion, a CO sensor for detecting a CO concentration in the combustion exhaust gas, and a CO for performing a safe operation according to the CO detected concentration of the CO sensor.
In a combustion device with a CO sensor equipped with a safety device,
In addition to the normal mode fan control circuit that controls the rotation of the combustion fan during the normal combustion operation mode,
An inspection rotation speed setting circuit for the combustion fan that forcibly generates each CO concentration gas for operating the O safety device is provided.
When inspecting the CO sensor, the combustion fan is operated in combustion mode and the rotation control of the combustion fan is switched from the normal mode fan control circuit to the inspection rotation speed setting circuit to deteriorate combustion, and safe operation of CO concentration corresponding to this combustion deterioration. A sensor inspection method for a combustion device with a CO sensor, which inspects whether the CO sensor is good or bad depending on whether or not