JPH0526439A - Incomplete combustion preventing device for combustion apparatus - Google Patents

Abstract

PURPOSE:To improve convenient operability by performing an alarm by a CO sensor or a control of stop of an apparatus when an output of the sensor is unstable. CONSTITUTION:Since CO concentration might become high at the time of switching the number of burners when the number of the burners is switched, an output of a sensor is ignored, an alarm or control of stop of an apparatus is not executed even if the CO concentration reaches a reference value or more for a predetermined time until a timer reaches time's up from when the timer simultaneously starts counting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing incomplete combustion in combustion equipment such as a gas water heater and a gas table.

[0002]

2. Description of the Related Art In the prior art, a CO sensor is provided in the exhaust gas, and when the detected CO concentration value in the exhaust gas by the CO sensor reaches a predetermined constant value, the operation of the equipment is immediately stopped and the safety is improved. The control means to ensure

However, when the number of burners is switched or when the ignition is initially started, the CO concentration may be temporarily increased, so that the sensor output becomes unstable, and the sensor output is extremely unstable for a while after energization of the CO sensor is started. However, there is no means for coping with malfunctions when these sensor outputs are unstable.

[0004]

In the prior art, an unstable sensor output due to a temporary increase in CO concentration at the time of switching the number of burners or at the initial stage of ignition, or an unstable sensor output immediately after energization of the CO sensor. Therefore, there is a problem in that it is practically inconvenient because an alarm is issued or a device stop is controlled even if there is no danger.

In view of such problems of the prior art, the present invention provides an alarm or CO sensor output when the sensor output is unstable at the time of switching the number of burners and at the beginning of ignition or immediately after energization of the sensor. It is an object of the present invention to provide an incomplete combustion prevention device for a combustion device that is safe and easy to use by not controlling the device stop.

[0006]

In order to achieve the above-mentioned object, an incomplete combustion preventing device for a combustion apparatus according to the present invention has a CO sensor installed in the exhaust gas and an output of the CO sensor which is predetermined. Comparison control means for comparing the CO concentration reference values to determine incomplete combustion, and when the comparison control means determines incomplete combustion, an alarm or a failure of the combustion equipment provided with means for stopping the equipment is provided. In the complete combustion prevention device,

At the time of switching the number of burners and at the time of initial ignition or when the sensor output is unstable immediately after the sensor is energized, CO
It is configured to have means for ignoring alarms or equipment stoppage control by sensor output for a certain period of time.

Then, a timer is used as a means for ignoring the alarm or the control for stopping the device for a certain period of time.

[0009]

The incomplete combustion prevention device for combustion equipment according to the present invention is
With the above configuration, the CO concentration in the exhaust gas detected by the CO sensor installed in the exhaust gas is compared with a predetermined and stored reference value by the comparison control means to determine whether the combustion is incomplete. To do.

When the comparison control means determines that the combustion is incomplete, an alarm or a device stop command is issued to the alarm means such as an alarm lamp or the device operation stop means, and the alarm lamp is turned on to inform that effect. Or, for example, in the gas water heater, the operation of the equipment is immediately stopped by closing the original solenoid valve.

At the time of switching the number of burners, which makes the sensor output unstable, and at the beginning of ignition or after the CO sensor is energized, the timer starts timing and the timer is operating, that is, until the timer expires. Do not shut down the device. However, after the timer expires, it immediately starts reading the sensor output.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of an incomplete combustion preventing device for a combustion device according to the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a CO sensor, for example, as shown in FIG. 7, which is installed in an exhaust pipe 2 of a gas water heater and uses a combustion flame a of gas burners 3 and 4 to heat exchanger 5 The CO concentration contained in the exhaust gas after heat exchange after heating is detected, and the output is input to the comparison control device A described later.

A is a comparison control device for comparing the output of the CO sensor 1 with a predetermined and stored reference value to determine whether or not the combustion is incomplete. It is configured to issue an alarm or a device stop command to an alarm device B or a device stop device C described later.

Reference numeral B is an alarm device for issuing an alarm indicating that the combustion is incomplete based on the operation command from the comparison control device A, and is composed of, for example, an alarm lamp and an alarm buzzer.

C is a device stopping device that stops the operation of the device based on the operation command from the comparison control device A at the time of incomplete combustion. For example, in the gas water heater of FIG. 7, gas supply to the gas burners 3 and 4 is performed. The operation of the equipment is stopped by closing the original solenoid valve 7 provided on the path 6.

D is means for ignoring the alarm or the control for stopping the equipment due to the output of the CO sensor for a certain time at the time of switching the number of burners at which the sensor output becomes unstable and at the beginning of ignition or after the energization of the CO sensor is started. A timer is provided to start timing when the number of burners is switched and at the initial stage of ignition or after the start of energization of the CO sensor, and the alarm or the device is not stopped while the timer is operating.

When the number of burners is changed, for example,
As shown in FIG. 7, two sets of gas burners 3 and 4 formed by arranging a plurality of burner units in parallel are provided, and the two sets of gas burners 3 and 4 are supplied with fuel gas from the gas supply passage 6 separately. The gas pipes 6a and 6b are provided so as to separately supply the gas pipes 6a and 6b, and the switching solenoid valves 8 and 9 are provided to the respective gas pipes 6a and 6b so that the capacity of the combustion equipment can be varied. In the case of, both sets of gas burners 3 and 4 are burned together,
When the capacity is low, it means controlling by the switching solenoid valves 8 and 9 so that only one set of gas burners 3 or 4 is burned.

In FIG. 7, 10 is a gas supply path 6
A proportional control valve provided in the above, 11 and 12 are gas nozzles, 13 is a water supply pipe, 14 is a hot water supply pipe, 15 is an air supply fan, 16 is a hot water tap, and 17 is a combustion chamber.

The operation of the configuration of the above embodiment will be described below.

The CO sensor 1 provided in the exhaust stack 2 detects the CO concentration in the exhaust gas and inputs its output to the comparison control device A.

In the comparison control device A, when the CO concentration detection value from the CO sensor 1 is input, it is compared with a prestored reference value of the CO concentration, and the CO concentration in the exhaust gas has a high practical risk. It is determined whether the value is incomplete combustion.

When it is judged that the combustion is incomplete, the alarm device B
A warning command is issued to notify that effect, or an operation command is issued to the device stopping device C to close the original solenoid valve 7 to immediately stop the operation of the device.

In the incomplete combustion prevention operation by the CO sensor 1, when the ignition to the gas burners 3 and 4 is started or 2
When the so-called number of burners is switched, that is, when the number of burners is switched, the CO concentration may temporarily increase (see FIG. 2).

Therefore, as shown in FIG. 2, when the number of burners is switched (for example, one burner to two burners).
The timer is turned on to start the clock, and the alarm or the device is not stopped while the timer is operating. Therefore, the fixed time T until the timer expires is
For example, even if the CO concentration reaches the reference value or more, the sensor output is ignored, so that the alarm is not issued and the device is not stopped.

As soon as the timer times out,
Since the sensor output is started to be read, even if CO is generated from the time the number of burners is switched and its concentration is above the reference value, there is no danger (see FIG. 3).

The operation of ignoring the alarm or the control for stopping the equipment by the sensor output at the time of switching the number of burners illustrated in FIGS. 2 and 3 will be described with reference to the flowchart of FIG. 5. In step 100, the gas burner is ignited to burn. When started, the timer is started at the beginning of ignition in step 101 or at the time of switching the number of burners thereafter, and the time counting is started in step 102.

Until the timer expires in step 103, that is, the sensor output is ignored for a certain period of time, no alarm is issued or the device is not stopped.

However, as soon as the timer times out in step 103, the sensor output starts to be read in step 104, and if the CO concentration reaches a reference value or more, an alarm or device stop control is performed in step 105, which is dangerous. There is no.

Further, the output of the CO sensor 1 becomes unstable for a while after the energization is started. According to the measurement result, the output change is as shown in FIG. 4, the output is − for about 10 seconds after the start of energization by turning on the switch.
It fluctuates in the range of 1.7V to 1.3V and is very unstable. It takes about 11 minutes to be completely stable.

Therefore, the timer is turned on at the same time when the energization of the CO sensor is started to start the time counting, and the alarm or the device is not stopped during the operation of the timer. Therefore, the fixed time until the timer expires is
Even if the O concentration reaches the reference value or more, the sensor output is ignored, so that the warning is not issued and the device is not stopped.

As soon as the timer times out,
Since the reading of the sensor output is started, there is no danger even if CO is generated from when the CO sensor is energized and its concentration is above the reference value.

The operation of ignoring the control by the sensor output after the start of energization of the CO sensor will be described with reference to the flowchart of FIG. 6. In step 200, the gas burner is ignited to start combustion, and in step 201, the CO sensor is energized. Is started, the timer is started and the time counting is started in step 202.

Until the timer times out in step 203, that is, the sensor output is ignored for a certain period of time, so that the alarm is not issued and the device is not stopped.

However, as soon as the timer times out in step 203, the sensor output starts to be read in step 204, and if the CO concentration exceeds the reference value, an alarm or equipment stop control is performed in step 205, which is dangerous. There is no.

[0036]

EFFECT OF THE INVENTION The incomplete combustion prevention device for a combustion device according to the present invention prevents an accident such as CO poisoning from occurring due to an alarm by an alarm means or a stop of the device by an equipment stopping means. When the number of burners is changed, the warning by the output of the CO sensor at the initial stage of ignition or immediately after the CO sensor is energized or the stop of the device is not controlled for a certain time by the timer.

Therefore, when the sensor output is unstable, the sensor output is ignored and an alarm or device stop control is not performed. Therefore, when the number of burners is switched, an alarm is issued for CO concentration exceeding a temporary reference value. Alternatively, since the malfunction of the sensor output in an unstable state can be avoided without stopping the device, there is an effect that the usability is improved practically.

Since the sensor output starts to be read immediately after the timer has timed out, CO is generated even when the number of burners is changed, and it is dangerous even if the concentration exceeds the reference value. There is no.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of main functional portions of an incomplete combustion prevention device for a combustion device according to the present invention.

FIG. 2 is a graph showing an example of the relationship between the CO concentration at the time of switching the number of burners and the timing of a fixed time by a timer.

FIG. 3 is a graph showing an example of a sensor output reading state after the timer time is up.

FIG. 4 is a graph showing an example of a change in output immediately after energization of a CO sensor.

FIG. 5 is a flowchart showing an example of an operating state at the time of switching the number of burners or at the beginning of ignition.

FIG. 6 is a flowchart showing an example of an operating state after the CO sensor is energized.

FIG. 7 is a schematic sectional view of a gas water heater to which the present invention is applied.

[Explanation of symbols]

1 CO sensor A comparison control means B Warning means C equipment stopping means Means to ignore D sensor output T fixed time

Claims (3)

[Claims] 1. A CO sensor installed in exhaust gas, comparison control means for comparing the output of the CO sensor with a reference value of a predetermined CO concentration to judge incomplete combustion, and the comparison control means. In an incomplete combustion prevention device for a combustion device, which is provided with means for issuing an alarm or stopping the device when incomplete combustion is determined, when the sensor output is unstable, CO
An incomplete combustion prevention device for a combustion device, which is provided with means for ignoring a warning or a device stop control by a sensor output for a certain period of time. 2. The combustion device according to claim 1, wherein a timer is used to count a fixed period of time when switching the number of burners, which makes the sensor output unstable, or ignoring the control by the output of the CO sensor or the control for stopping the device at the beginning of ignition. Complete combustion prevention device. 3. The incomplete combustion apparatus according to claim 1, wherein a timer measures time for ignoring a warning or control for stopping the apparatus due to the output of the CO sensor after the energization of the CO sensor whose sensor output becomes unstable. Combustion prevention device.