JPH08128981A - Unburnt component concentration detecting device for combustion equipment - Google Patents

Abstract

PURPOSE: To precisely detect the CO concentration in a combustion exhaust gas in the state where its change state can be properly judged. CONSTITUTION: This device has a measuring CO sensor 17 for detecting the CO concentration contained in the combustion exhaust gas passed in the exhaust passage of a burner 3, and a correcting CO sensor 32 for intermittently detecting the CO concentration contained in the combustion exhaust gas on the basis of the correction command by a correction instructing means 101. It also has an exhaust gas flow arresting means C for keeping the non-flowing state where the combustion exhaust gas never flow to the correcting CO sensor 32, and switching the flowing state to the exhaust gas flowing state in which the combustion exhaust gas flows to the correcting CO sensor 32 only when the detecting operation of CO concentration by the correcting CO sensor 32 is executed on the basis of the correction command; and a detected value correcting means 103 for correcting the detected value by the measuring CO sensor 17 on the basis of the detection information of the correcting CO sensor 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unburned component concentration of a combustion device equipped with an unburned component concentration detecting means for detecting the concentration of unburned component contained in a combustion exhaust gas passing through an exhaust passage of a burner. Regarding a detection device.

[0002]

2. Description of the Related Art An unburned component concentration detecting device for a combustion apparatus having the above structure detects the unburned component concentration in the combustion exhaust gas by the unburned component concentration detecting means, and the detected value is set in advance, for example. If it exceeds the upper limit, it is judged that the burner is incompletely burned, and by taking measures such as stopping the burner combustion and activating the alarm means, the state where the unburned component concentration is high becomes long. This is so that it can be prevented from continuing.

By the way, the combustion exhaust gas of the burner contains, for example, harmful substances such as sulfur components. Such harmful substances are solidified and adhere to the surface of the unburned gas concentration detecting means. Or, it has an adverse effect such as progressing corrosion, and as a result, the detection sensitivity of the unburned gas concentration detection means is likely to deteriorate along with the detection operation of the concentration of unburned component in the combustion exhaust gas. Become.

Therefore, conventionally, the unburned component concentration detection means intermittently performs the unburned component concentration detection operation, and the unburned component concentration detection means is operated while the detection operation is not performed. It has been considered that the combustion exhaust gas does not flow and the influence of the harmful substances as described above is minimized.

[0005]

However, even in the above configuration, the combustion exhaust gas flows to the unburned component concentration detecting means while the detection operation is being executed, which results from the above-mentioned adverse effects. The deterioration of sensitivity was inevitable.

As a result, there is a disadvantage in that the detection sensitivity of the unburned component concentration detecting means deteriorates as the usage time increases, and the unburned component concentration may not be accurately detected.

Therefore, it is conceivable to make the waiting time from the execution of the above detection operation to the next detection operation, that is, the time during which the combustion exhaust gas does not flow to the unburned component concentration detection means, be extremely long. If this is set, there is a disadvantage that the change state of the concentration of unburned components in the combustion exhaust gas cannot be properly determined.

Further, the change characteristic of the sensitivity deterioration as described above with respect to the integration time of the combustion exhaust gas flowing in the unburned component concentration detecting means is set in advance, and is set in advance with the integration time. It is possible to correct the detection value of the unburned component concentration detection means based on the change characteristics, but the flow state of the combustion exhaust gas constantly changes, and the combustion state of the burner and the operating state of other devices The degree of change with time varies due to individual differences in the combustion device, and the relationship between the integration time and the change characteristic of sensitivity deterioration is not always constant, so the detection accuracy of the unburned component concentration decreases. There is a great risk of doing so.

The present invention has been made paying attention to such a point, and an object thereof is to accurately detect the unburned component concentration in the combustion exhaust gas in a state where its change state can be appropriately discriminated. It is an object of the present invention to provide an unburned component concentration detection device for a combustion device that enables the above.

[0010]

The features of the first invention are as follows:
In an unburned component concentration detection device of a combustion device, which is provided with unburned component concentration detection means for detecting the concentration of unburned component contained in the combustion exhaust gas passing through the exhaust passage of the burner, the unburned component concentration detection means However, the unburnt component concentration detection means for measurement to detect the concentration of the unburned component, the concentration of the unburned component contained in the combustion exhaust gas, based on the correction command by the correction command means, the correction to intermittently detect A plurality of unburned component concentration detecting means for use, and a plurality of correction unburned component concentration detecting means are maintained, in which the combustion exhaust gas does not flow, and the correction command Based on the exhaust gas flow, the combustion exhaust gas flows to the correction unburned component concentration detection means only when the correction unburned component concentration detection means performs the unburned component detection operation. To the state Exchanging exhaust gas flow prevention means is provided, and based on the detection information of the correction unburned component concentration detection means, detection value correction means for correcting the detection value by the measurement unburned component concentration detection means is provided. There is a point.

A characteristic configuration of the second invention is to specify a configuration suitable for carrying out the first invention, in which the measuring unburned component concentration detecting means determines a change in concentration of the unburned component. For each setting short time required for, is configured to execute the concentration detection operation of the unburned component, to the measurement unburned component concentration detection means, the non-flowing state in which the combustion exhaust gas does not flow, Exhaust gas flow state switching means is provided that is switchable to an exhaust gas flow state in which combustion exhaust gas flows, and when the detection operation by the measurement unburned component concentration detection means is executed, the exhaust gas flow state switching means is set. A switching control means is provided for switching the exhaust gas flow state switching means to a non-flow state when the exhaust gas flow state is switched to a state where the detection operation is not executed.

The characteristic constitution of the third invention is to specify a constitution suitable for carrying out the first or second invention, wherein the detection value correcting means is the unburned component for correction in the same concentration state. The ratio of the detection value of the measurement unburned component concentration detection means to the detection value of the concentration detection means, as a correction coefficient, based on this correction coefficient, the detection value by the measurement unburned component concentration detection means The point is that it is configured to correct.

The characteristic configuration of the fourth aspect of the invention specifies a configuration suitable for carrying out the third aspect of the invention, wherein the unburned component for correction is in the same concentration state in the initial state when the combustion operation is started. The ratio of the detection value of the measurement unburnt component concentration detection means to the detection value of the concentration detection means is obtained as an initial correction coefficient, and the detection value correction is performed with respect to the initial correction coefficient as combustion operation is continued. When the ratio of the correction coefficient obtained by the means falls below a set value, it is determined that the sensitivity is in a deteriorated state, and a post-processing executing means for executing the post-processing is provided.

The characteristic configuration of the fifth aspect of the invention specifies a configuration suitable for carrying out the fourth aspect of the invention, in which the aftertreatment executing means stops combustion of the burner as the aftertreatment. There is a point.

A characteristic configuration of the sixth invention is to specify a configuration suitable for carrying out the first, second, third, fourth or fifth invention, wherein the correction command means is arranged to It is configured to issue the correction command every time the set time for correction is reached.

The characteristic constitution of the seventh invention is to specify the constitution suitable for carrying out the first, second, third, fourth, fifth or sixth invention, and to detect the concentration of each unburned component. The means is that it is composed of a catalytic combustion type CO sensor.

[0017]

According to the characterizing feature of the first aspect of the invention, the measuring unburned component concentration detecting means appropriately detects the concentration of unburned component in the combustion exhaust gas. For example, the unburned component concentration is detected continuously or at each set short time required to determine the change in the unburned component concentration.

With respect to the unburned component concentration detecting means for correction, the state in which the combustion exhaust gas does not flow is maintained by the exhaust gas flow inhibiting means.

Then, based on the correction command from the correction command means, the detection operation by the correction unburned component concentration detection means is intermittently executed, but the exhaust gas flow blocking means is executed only when the detection operation is executed. Is switched to the exhaust gas flow state, and the combustion exhaust gas flows to the correction unburned component concentration detecting means.

Therefore, the time for the combustion exhaust gas to flow to the correction unburnt component concentration detection means is shorter than the time for the combustion exhaust gas to flow to the measurement unburned component concentration detection means, resulting in sensitivity deterioration. The unburned component concentration can be detected in a low and highly accurate state, and the detection value of the unburned component concentration detection means for measurement is corrected based on the highly accurate detection information of this unburned component concentration detection means for correction. Of.

According to the characterizing structure of the second invention, the following function is obtained in addition to the function of the characterizing structure of the first invention. The unburned component concentration detection means for measurement executes the unburned component concentration detection operation at each set short time necessary for distinguishing the concentration change of the unburned component in the combustion exhaust gas, but this detection operation is performed. In this case, the exhaust gas is switched to the flowing state, and is switched to the non-flowing state when the detection operation is not executed. Therefore, due to harmful substances in the combustion exhaust gas, for example, they are solidified and adhere to the surface of the unburned component concentration detection means, which lowers the detection function of the unburned component concentration detection means for measurement, or progresses corrosion. It is possible to reduce the adverse effects such as causing it.

According to the characterizing feature of the third invention, the following effect is obtained in addition to the effect of the characterizing feature of the first or second invention.
The ratio of the detection value of each unburned component concentration detection means in the same concentration state is obtained as a correction coefficient, and the detection value of the measurement unburned component concentration detection means is corrected based on this correction coefficient.

That is, it is detected in the same concentration state as the detection value of the unburned component concentration detecting means for measurement, which is considered to have deteriorated the detection sensitivity because the combustion exhaust gas flows for a long time. Based on the ratio (correction coefficient) to the detection value of the unburned component concentration detection means for correction, the detection value of the unburned component concentration detection means for measurement becomes the detection sensitivity of the unburned component concentration detection means for correction. It will be corrected to an appropriate value corresponding to the accurate detection value based on the above.

According to the characterizing structure of the fourth invention, in addition to the function of the characterizing structure of the third invention, there is the following function. In the initial state when the combustion operation is started, sensitivity deterioration due to harmful substances in the combustion exhaust gas does not occur, so the initial correction coefficient is the ratio of individual differences in the initial characteristics of the unburned component concentration detection means. Will be required as.

With the continuation of the combustion operation, the detection value correction means causes the ratio (correction coefficient) of the detection value of the measurement unburned component concentration detection means to the detection value of the correction unburned component concentration detection means. Is appropriately obtained based on the correction command, but the ratio of this correction coefficient to the initial correction coefficient is less than the set value, thereby reducing the error due to the individual difference of each unburned component concentration detecting means, which is more accurate. In this state, it is judged that the detection sensitivity of the unburned component concentration detecting means for measurement is deteriorated, and for example, post-processing such as stopping the combustion of the burner or executing an alarm operation is performed. is there.

According to the characterizing feature of the fifth aspect of the invention, there are the following effects in addition to the effects of the characterizing feature of the fourth aspect of the invention. When it is determined that the detection sensitivity of the unburnt component concentration detection means for measurement is degraded, the burner combustion is stopped, so the detection sensitivity is degraded and the concentration of unburned component in the combustion exhaust gas is accurately determined. Burner combustion does not continue in a state that cannot be detected.

According to the characterizing feature of the sixth invention, the following effect is obtained in addition to the function according to the characterizing feature of the first, second, third, fourth or fifth invention. Every time the cumulative combustion time reaches the set time for correction, the detection value of the unburned component concentration detection means for measurement is automatically corrected. Therefore, the correction operation is appropriately executed without any troublesome operation.

According to the characteristic construction of the seventh invention, the following operation is provided in addition to the operation of the characteristic construction of the first, second, third, fourth, fifth or sixth invention. As an unburned component in the combustion exhaust gas, the concentration of carbon monoxide (CO), which is most likely to have a bad influence on the human body, is effectively detected with a small error due to sensitivity deterioration.

[0029]

According to the characterizing feature of the first invention, the unburned component concentration detecting means for measurement can appropriately detect the change in the concentration of the unburned component in the combustion exhaust gas. In addition to being able to perform the operation, by correcting the detection value based on the highly accurate detection information by the correction unburned component concentration detection means, regardless of the sensitivity deterioration due to the harmful substances in the combustion exhaust gas. It is possible to detect the unburned component concentration with high detection accuracy at all times.

According to the characterizing structure of the second invention, the following effect is obtained in addition to the effect of the characterizing structure of the first invention. The unburned component concentration detection means for measurement suppresses the sensitivity deterioration caused by the harmful substances to as little as possible, and the concentration of the unburned component can be detected with high detection accuracy for a long period of time as much as possible. .

According to the characterizing structure of the third invention, the following effect is obtained in addition to the effect of the characterizing structure of the first or second invention.
Since the detection value is always corrected based on the ratio of the detection values of the respective unburned component concentration detection means in the same concentration state, the correction operation is appropriately performed in the state where the error is small.

According to the characterizing structure of the fourth invention, the following effect is obtained in addition to the effect of the characterizing structure of the third invention. The detection operation is performed in a state where there are few errors due to individual differences in the unburned component concentration detection means and the accuracy is high, and when the deterioration of the detection sensitivity is large, appropriate post-processing is performed to ensure safety in use. Nature will be secured.

According to the characterizing feature of the fifth invention, the following effect is obtained in addition to the effect of the characterizing feature of the fourth invention. With the continued combustion of the burner, disadvantages such as the concentration of unburned components in the combustion exhaust gas exceeding the set upper limit and becoming high can be avoided.

According to the characterizing structure of the sixth invention, the following effects are obtained in addition to the effects of the characterizing structure of the first, second, third, fourth or fifth invention. Compared to the case of the correction command by the manual operation, the detection value correction operation is surely executed without forgetting the operation or in the trouble.

According to the characterizing structure of the seventh invention, the following effect is obtained in addition to the effect of the characterizing structure of the first, second, third, fourth or fifth invention. By accurately detecting the concentration of carbon monoxide, it is possible to ensure safety in use.

[0036]

Embodiments will be described below with reference to the drawings. FIG.
FIG. 1 shows a hot water supply device as an example of the combustion device according to the present invention. This hot water supply device includes a hot water supply unit A, a control unit H that controls the operation of the hot water supply unit A, and a remote control device R that issues control information to the control unit H.

In the hot water supply unit A, a heat exchanger 2 for heating water and a burner 3 for heating the heat exchanger 2 are provided in the combustion chamber 1, and the burner 3 burns in the combustion chamber 1. Ventilation air is passed and the combustion exhaust gas from the burner 3 is transferred to the combustion chamber 1
A fan 5 is provided as a ventilating means for exhausting the air through the exhaust pipe 4 to the outside of the room. On the upper side of the burner 3 in the ventilation path in the combustion chamber 1, a wind regulating plate 6 made of a perforated plate is provided.
Is provided, and the wind generated by the fan 5 is configured to be substantially evenly passed through the burner 3.

Further, the heat exchanger 2 is connected to a water supply passage 7 for supplying water and a hot water supply passage 8 for supplying heated hot water to a hot water tap (not shown), and the water supply passage 7 is provided with a heat exchanger. An inlet water temperature sensor 9 for detecting the inlet water temperature to the heat exchanger 2 and a water amount sensor 10 for detecting the amount of water supplied to the heat exchanger 2 are provided, and a hot water outlet 8 for detecting the outlet water temperature of the heat exchanger 2 is provided in the hot water supply passage 8. A temperature sensor 11 is provided.

The fuel gas supply passage 12 for the burner 3 is provided with an opening / closing valve 13 for intermittently supplying the fuel gas and an electromagnetic gas amount adjusting valve 14 for adjusting the fuel gas supply amount.
An igniter 15 for ignition and a frame rod 16 for detecting whether or not the burner 3 has ignited are provided near the burner 3.

Further, in the exhaust passage L through which the combustion exhaust gas of the burner 3 passes, an unburned gas for measurement for detecting the concentration (CO concentration) of carbon monoxide (CO) as an unburned component contained in the combustion exhaust gas. Contact combustion type measuring C as a component concentration detecting means
An O sensor 17 is provided. CO sensor for measurement 17
Is installed inside the first box body 19 which is partially opened so as to communicate with the exhaust passage L through the opening 18 in the exhaust passage L through which the combustion exhaust gas passes. The exhaust path L
A guide plate 20 for effectively guiding the combustion exhaust gas flowing upward to the inside of the first box body 19 is provided at a position close to the opening portion 18 of the above.

A part of the wind generated by the fan 5 as a blower source in a state where the upstream side of the air conditioning plate 6 communicates with the inside of the first box body 19, that is, the exhaust passage. First air duct 2 for guiding the air to the vicinity of the measuring CO sensor 17
1 is formed, and a valve open state that allows wind to be guided into the first box body 19 is cut off at a location near the fan 5 in the first air duct 21 and the first air duct 21 is shut off. There is provided an electromagnetically operated first air passage opening / closing valve 22 which can be switched to a closed state in which the air guide is stopped. When the wind is guided into the first box body 19, the combustion exhaust gas cannot flow into the first box body 19, and when the wind guide is stopped, the combustion exhaust gas flows into the first box body 19. It is possible to measure the CO concentration.

Therefore, the first air passage 21 and the first air passage opening / closing valve 22 switch the exhaust gas flowing state in which the combustion exhaust gas flows and the non-flowing state in which the combustion exhaust gas does not flow to the measuring CO sensor 17. A possible exhaust gas flow state switching means B is configured.

Then, as shown in FIG. 2, the measuring C
As with the first box body 19, the O sensor 17 is installed inside the second box body 31 that is partially opened so as to communicate with the exhaust passage L through the opening 30 as in the case of the first box body 19. so,
A contact combustion type correction CO sensor 32 is provided as a correction unburned component concentration detecting means. In a state where the inside of the second box body 31 and the ventilation side of the air conditioning plate 6 are in communication with each other, a part of the wind generated by the fan 5 is corrected C
A second air duct 33 is formed near the O sensor 32,
When the wind is guided into the second box body 31, the combustion exhaust gas cannot flow into the second box body 31 and the combustion exhaust gas does not flow into the correction CO sensor 32, resulting in a non-flowing state.

At a position near the fan 5 in the second air guide path 33, a valve open state that allows the wind to be guided into the second box body 31 and a state where the second air guide path 33 is cut off are introduced. An electromagnetically operated second air passage opening / closing valve 34, which can be switched to a closed state in which the wind is stopped, is provided. The second air passage opening / closing valve 34 is opened when there is no correction command as described later. It is maintained and kept in a non-flowing state.

Each of the CO sensors 17 and 32 has a characteristic that the output changes substantially linearly with respect to the change in the CO concentration to be detected, and the sensitivity due to the sulfur component etc. in the combustion exhaust gas. The deterioration has a characteristic that the inclination of the detection characteristic changes while maintaining the linear state.

The remote controller R has an operation switch 23 for instructing start / stop of operation, a temperature display section 24 for displaying the hot water supply temperature, and a temperature setting switch 2 for setting a target hot water supply temperature.
5, an operation lamp 26 for displaying whether or not it is in an operating state, and an abnormality display lamp 2 that lights up when an abnormal state described later occurs
7 etc. are provided.

The control unit H comprises a microcomputer, and based on the detection information of the sensors 9, 10, 11 and the flame rod 16, the amount of gas is adjusted so that the combustion of the burner 3 is in an appropriate combustion state. Control valve 14, fan 5
And the like, a correction command means 101 for issuing a correction command every time the integrated combustion time reaches a set time for correction, and a non-flowing state for the correction CO sensor 32. C for correction based on the correction command
Only when the detection operation by the O sensor 32 is executed, the first switching control means 102 for flowing the combustion exhaust gas to the correction CO sensor 32 and the detection information of the correction CO sensor 32 based on the correction command. Based on the detection value correction means 103 for correcting the detection value of the measurement CO sensor 17 and the sensitivity deterioration state associated with the correction of the detection value, it is determined as an abnormal state and post-processing is performed. , A post-processing execution means 104 for executing a combustion stop operation of the burner 3 and an operation of lighting the abnormality display lamp 27, and a measuring CO sensor 17
The second switching control means 105 for controlling the switching of the exhaust gas flow state switching means B so that the exhaust gas flow state is set when the detection operation is performed and the non-flow state is set when the detection operation is not performed. It is equipped with.

Therefore, the exhaust gas flow blocking means C is constituted by the second air guide passage 33, the second air passage opening / closing valve 34 and the first switching control means 102.

The control operation of the controller H will be described below with reference to the control flowcharts shown in FIGS. When it is determined that the hot water tap has been opened due to the detection value of the water amount sensor 10 exceeding the set value after the operation switch 23 is turned on, the ventilation operation of the fan 5 is started,
Energization of the measuring CO sensor 17 is started (steps 1 to 4). Then, the first and second air passage opening / closing valves 22, 3
After opening both valves 4 (step 5), ignition control for the burner 3 is executed (step 6). That is, when the igniter 15 ignites the burner 3 and the flame rod 16 confirms ignition, the ignition operation is stopped.

At this time, the first air passage opening / closing valve 22 is opened, and a part of the wind generated by the fan 5 is introduced into the first box body 19 through the first air passage 21. The combustion exhaust gas of the burner 3 cannot flow into the first box body 19, and the combustion exhaust gas is suppressed from flowing to the measurement CO sensor 17.

When combustion is started, combustion control is executed to control the burner 3 to an appropriate combustion state so that the hot water supply temperature becomes the target hot water supply temperature (step 7). That is, the feedforward operation amount is determined based on the deviation between the target hot water supply temperature set by the temperature setting switch 25 and the incoming water temperature detected by the incoming water temperature sensor 9, and the amount of water supplied by the water amount sensor 10. Along with the calculation, the feedback operation amount is obtained based on the deviation between the target hot water supply temperature and the detected value of the hot water temperature sensor 11, and the gas amount control valve 14 is operated and controlled based on the added value of each operation amount to control the gas amount. In addition, the number of rotations of the fan 5 is controlled so that the amount of ventilation is suitable for the amount of gas.

Then, the counting of the first timer and the second timer is started (step 8). If it is determined that the first timer has finished counting and the first set time T ₁ (10 minutes) has elapsed, after resetting the first timer,
The first air passage opening / closing valve 22 is closed to stop the air blowing through the first air passage 21 (steps 9, 10, 11). First
By closing the air passage opening / closing valve 22, the first box 1
9 is stopped, the combustion exhaust gas passing through the exhaust passage L flows into the first box body 19, and the measurement C
As it flows toward the O sensor 17, CO for measurement
The CO concentration can be measured by the sensor 17.

When the hot water tap is closed by the time the first set time T ₁ elapses, the combustion of the burner 3 is stopped and the operation of the fan 5 is stopped after the post-purging,
By closing the first and second air passage opening / closing valves 22 and 34, the measurement CO
The power supply to the sensor 17 is stopped (steps 9 and 17-).
22).

After step 11, the second timer finishes counting, and before it is determined that the second correction time T ₂ (50 hours) has elapsed, the combustion exhaust gas in the first box 19 is exhausted. When the third set time T ₃ required for the uniform mixing of CO 2 has elapsed, the CO concentration measurement by the measuring CO sensor 17 is executed to determine whether the measured CO concentration does not exceed the set upper limit value. (Steps 12 to 1
5), the first air passage opening / closing valve 22 is opened (step 1
6).

After that, the measured CO concentration exceeds the set upper limit value and it is not judged that the combustion is incomplete.
If the hot water tap is not closed (steps 17, 1)
8), steps 7 to 16 are repeatedly executed,
The CO concentration measurement (detection operation) by the measurement CO sensor 17 is executed every first set time T ₁ (10 minutes), and the exhaust gas flow state is switched only when the CO concentration measurement is executed. It will be. The first set time T
₁ corresponds to the set short time required to determine the change in the concentration of the unburned component (CO). Step 7 to Step 16
While the above is repeated, the second air passage opening / closing valve 34 is maintained in the open state, and the correction CO sensor 32 is maintained in a state in which the exhaust gas does not flow. When it is determined in step 17 that the combustion is incomplete, the abnormality display lamp 27 is turned on and the combustion of the burner 3 is stopped (step 2
3, 24).

When it is determined in step 12 that the second timer has finished counting and the second correction time T ₂ (50 hours) has elapsed, the power supply to the correction CO sensor 32 is started. , It is determined whether or not the combustion operation is in the initial state, and if it is the initial state, an initial correction coefficient is obtained and stored in the memory (steps 25, 26, 2).
7). That is, the CO sensors 17, 32 simultaneously
In other words, CO concentration measurement is performed in the same concentration state,
The ratio (a / b) of the detection value a of the measurement CO sensor 17 to the detection value b of the correction CO sensor 32 is calculated as an initial correction coefficient k.
₀ is stored in the memory.

Then, the second timer is reset (step 28) and the second air passage opening / closing valve 34 is closed (step 29). By closing the second air passage opening / closing valve 34, the air guide state into the second box body 31 is stopped, so the combustion exhaust gas passing through the exhaust passage L flows into the second box body 31, It flows toward the correction CO sensor 32, and the CO concentration can be measured. When the third set time T ₃ required for the combustion exhaust gas to be uniformly mixed in the second box 31 has elapsed, the correction CO sensor 32 and the measurement CO sensor 17 simultaneously measure the CO concentration in the same concentration state. Is executed (steps 30 and 31).
Then, based on the respective CO concentration detection values, the measurement CO
It is determined whether or not the sensitivity of the sensor 17 has deteriorated (step 32). That is, if the difference between the detected values is equal to or larger than the set value, it is determined that the sensitivity is deteriorated, and if the difference is less than the set value, it is determined that the sensitivity is not deteriorated.

When it is determined that the sensitivity has deteriorated, the detection value of the measuring CO sensor 17 is corrected based on the detection value of the correcting CO sensor 32 (steps 33 and 34). That is, the detection value of the measurement CO sensor 32 is set to the initial correction coefficient or the reciprocal (1 / k ₀ or 1 / k) of the correction coefficient (k ₀ or k) described below after the correction operation described below is executed. The multiplied value is used as the corrected detection value. For example, if the detection value of the measuring CO sensor is x, the corrected detection value y is

[0059]

[Formula 1] y = x · (1 / k)

Or

[0061]

[Number 2] y = x · (1 / k 0)

It becomes

The ratio (f / e) of the detection value f of the measuring CO sensor to the detection value e of the correcting CO sensor 32 during the measurement in step 29 is set as the correction coefficient k,
Ratio of initial correction coefficient k ₀ to this correction coefficient (k ₀ /
If k) is less than or equal to "0.5", it is determined that the abnormal state is significantly deteriorated, and as an after-treatment, the abnormality display lamp 27 is turned on and the combustion of the burner 3 is stopped ( Steps 35, 36, 37). If the abnormal state as described above is not determined, the first and second air passage opening / closing valves 22, 3
4 is operated together to stop the energization of the correction CO sensor 32, and the correction operation is finished (steps 35, 38,
39).

Since the second timer continues counting while the combustion operation is being executed unless the above-described correction operation is executed, the correction operation is completed by the second timer (combustion integration time The set time T ₂ is reached).

When the corrected CO concentration exceeds the set upper limit value and it is determined that the combustion is incomplete, the abnormality display lamp 27 is turned on and the combustion of the burner 3 is stopped (steps 17 and 23). , 24). If it is not determined that the combustion is incomplete and the hot water supply plug is not closed, the process returns to step 7, and when it is closed, the combustion of the burner 3 is stopped and the operation of the fan 5 is stopped after the post-purge. By closing the first and second air passage opening / closing valves 22 and 34, the measurement CO sensor 1
The power supply to 7 is stopped (steps 19 to 22).

[Other Embodiments] (1) In the above embodiment, the measurement CO sensor 17 is intermittently switched between a flowing state and a non-flowing state, and is detected only in the exhaust gas flowing state. Although the configuration is such that the operation is executed, instead of such a configuration, the CO concentration may be measured every predetermined short time or continuously with the combustion exhaust gas always flowing. .

(2) In the above embodiment, when the ratio of the correction coefficient k to the initial correction coefficient k ₀ is below the set value, it is in an abnormal state and the combustion of the burner is stopped. The correction operation may be executed until is zero or almost zero.

(3) Further, in the above-mentioned embodiment, the exhaust gas flow state switching means B and the exhaust gas flow blocking means C are the first,
The case where the state in which the air is blown into the second boxes 19 and 31 is switched to the state in which the air is stopped has been illustrated, but the present invention is not limited to this, and the non-flowing state is set by the air blown around the CO sensor. However, the exhaust gas flow state may be set by switching the blowing direction. Further, as shown in FIG. 5, the exhaust gas flow state switching means and the exhaust gas flow blocking means are replaced with a configuration for switching the blowing state, and the exhaust path L and the inside of the box body 19 are communicated with each other (a) and the exhaust path. A state in which L and the inside of the box body 19 are shielded and the inside of the box body 19 and the outside of the device are communicated with each other (b)
Alternatively, a switching plate 28 that is switched and rotated may be provided, and the switching plate 28 may be rotated by an actuator (not shown) to switch between the exhaust gas flowing state and the non-flowing state.

(4) In the above embodiment, as the post-treatment, the combustion of the burner is stopped and the abnormality display lamp is turned on, but the combustion of the burner is simply stopped without using the abnormality display lamp. The configuration may be adopted, and the abnormality display lamp may be turned on or the alarm means such as an alarm buzzer may be activated without stopping the combustion of the burner.

(5) In the above embodiment, the correction command is issued every time the integrated combustion time reaches the set time.
A configuration may be adopted in which a correction command is issued as appropriate based on human operation.

(6) In the above embodiment, carbon monoxide (CO) is detected as an example of unburned components in the combustion exhaust gas, but the invention is not limited to this, and other unburned gases such as hydrogen are detected. You may do it.

It should be noted that reference numerals are added to the claims for facilitating the comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a hot water supply device.

FIG. 2 is a plan view showing an arrangement state of a CO sensor.

FIG. 3 is a flowchart of control operation

FIG. 4 is a flowchart of control operation.

FIG. 5 is a diagram showing an exhaust gas flow state switching means of another embodiment.

[Explanation of symbols]

3 burner 17 unburned component concentration detection means for measurement 32 unburned component concentration detection means for correction 101 correction command means 103 post-processing execution means 105 switching control means B exhaust gas flow state switching means C exhaust gas flow blocking means L exhaust path T ₁ setting short time

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasushi Maeda 1-52 Oka 1-chome, Minami-shi, Minato-ku, Osaka

Claims (7)

[Claims] 1. The unburned component concentration of a combustion device provided with unburned component concentration detection means for detecting the concentration of unburned component contained in the combustion exhaust gas passing through the exhaust passage (L) of the burner (3). In the detection device, the unburned component concentration detection means is a measurement unburned component concentration detection means (17) for detecting the concentration of the unburned component, and the concentration of the unburned component contained in the combustion exhaust gas, A plurality of correction unburned component concentration detection means (32) for intermittent detection based on the correction instruction by the correction instruction means (101) are provided, and the correction unburned component concentration detection means is provided. For (32),
The non-flowing state in which the combustion exhaust gas does not flow is maintained, and the unburned component detection operation by the correction unburned component concentration detection means (32) is executed based on the correction command only when the unburned component detection operation is executed. Unburned component concentration detection means for correction (3
2) is provided with an exhaust gas flow blocking means (C) that switches to an exhaust gas flow state in which the combustion exhaust gas flows, and based on detection information of the correction unburned component concentration detection means (32), Unburned component concentration detection means for measurement (1
Detection value correction means (103) for correcting the detection value by 7)
A device for detecting the concentration of unburned components in a combustion device provided with. 2. An unburned component concentration detecting means (1) for the measurement.
7) is configured to execute the concentration detection operation of the unburned component for each set short time (T ₁ ) required to determine the change in the concentration of the unburned component, and the unburned component for measurement is For the concentration detecting means (17),
An exhaust gas flow state switching means (B) capable of switching between a non-flowing state in which the combustion exhaust gas does not flow and an exhaust gas flow state in which the combustion exhaust gas flows is provided, and the unburned component concentration detection means (17) for measurement is used. The exhaust gas flow state switching means (B) is switched to the exhaust gas flow state when the detection operation is executed, and the exhaust gas flow state switching means (B) is set to the non-flow state when the detection operation is not executed. Switching control means for switching (10
5) The unburned component concentration detecting device for a combustion device according to claim 1, further comprising: 3. The detection value correction means (103) includes the measurement unburned component concentration detection means (17) for the detection value of the correction unburned component concentration detection means (32) in the same concentration state. 3. The ratio of the detected values of 1. is obtained as a correction coefficient, and the detection value by the measuring unburned component concentration detecting means (17) is corrected based on the correction coefficient. Unburned component concentration detection device of the combustion device. 4. In the initial state when combustion operation is started, the unburned component concentration detection means for measurement (17) with respect to the detection value of the unburned component concentration detection means for correction (32) in the same concentration state ) Is obtained as an initial correction coefficient, and the ratio of the correction coefficient obtained by the detection value correction means (103) with respect to the initial correction coefficient is set to a preset value. If it falls below, it is determined that the sensitivity is in a deteriorated state, and the post-processing executing means (10) that executes the post-processing is executed.
4) The unburned component concentration detecting device for the combustion device according to claim 3, further comprising: 5. The unburned component concentration detecting device for a combustion device according to claim 4, wherein the post-processing executing means (104) is configured to stop combustion of the burner (3) as the post-processing. . 6. The correction instruction means (101) is configured to issue the correction instruction every time the combustion integrated time reaches a set time for correction.
The unburned component concentration detection device of the combustion device according to 3, 4, or 5. 7. The unburned component concentration detecting means (17),
The unburned component concentration detecting device for a combustion device according to claim 1, wherein (32) is composed of a catalytic combustion type CO sensor.