JPH07332667A - Combustion device - Google Patents

Abstract

PURPOSE:To appropriately judge an incomplete combustion regardless of the difference in the generating status of an unburnt gas by a method wherein the status is judged to be an incomplete combustion when an interrupted period of time which is measured by an unburnt gas concentration generating condition-measuring means exceeds a set allowable period of time, and when an integrated value of an integrating means exceeds a permissible value. CONSTITUTION:An incomplete combustion judging means 101 is equipped with an integrating timer TMs. The integrating timer TMs compares a CO concentration CO being detected by first and second continuous timers TM1, TM2 which measure an interrupted period of time for a condition wherein the CO concentration CO being detected by a CO sensor S exceeds a set value for continuous judgement, and the CO sensor S, with criterion values with high and low two stages, and measures an integrated value of a combustion period of time by weighting more as the CO concentration CO exceeds the criterion value on the high side. The status is judged to be an incomplete combustion when the interrupted period of time which is measured by the first and second continuous timers T1, T2, and when the integrated value of the integrating timer TMs exceeds a permissible value. By this method, safety in the usage can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unburned gas concentration detecting means for detecting the unburned gas concentration in combustion exhaust gas of a burner, and the burner failure based on the detection result of the unburned gas concentration detecting means. Combustion provided with incomplete combustion determination means for determining complete combustion, and post-processing execution means for performing post-processing corresponding to incomplete combustion when the incomplete combustion determination means determines incomplete combustion Regarding the device.

[0002]

2. Description of the Related Art In the above combustion apparatus, conventionally, as shown in, for example, Japanese Unexamined Patent Publication (Kokai) No. 5-26438, the unburned gas concentration (C
(O concentration) exceeds the set value, the deviation between the unburned gas concentration and the set value is integrated over time to obtain an integrated value of the unburned gas concentration,
When the integrated value exceeds a preset limit value, there is a configuration in which, as post-processing for incomplete combustion, an alarm is activated and the operation of the apparatus is stopped. The combustion device as described above can perform an appropriate post-treatment depending on the actual amount of unburned gas concentration generated,
It is an improvement in safety.

[0003]

In the above conventional structure, since the deviation between the detected value of the unburned gas concentration and the set value is integrated over time, for example, when the combustion device is used intermittently. Even if there is an advantage that the amount of unburned gas generated can be accurately detected, there are still points to be improved in the points described below.

The unburned gas is generated, for example, when the ventilation passage for the combustion air for the burner is clogged with dust or the like and the ventilation volume decreases from the appropriate ventilation volume, or Ventilation is temporarily suppressed by the back wind from the outside at the outlet to the outside of the
It is also conceivable that the amount of ventilation to the burner inside the combustion device decreases and unburned gas is generated. Among the causes of incomplete combustion as described above, when the cause is the blockage of the ventilation passage, unburned gas is generated almost continuously with combustion. Although it is possible to accurately detect the amount of generated unburned gas, if unresolved gas from the outside causes a high concentration of unburned gas, this high unburned gas concentration is accumulated. , The integrated value exceeds the limit value, and although the actual amount of unburned gas concentration is reduced in the subsequent combustion, processing such as alarm activation and device shutdown is executed. However, there is a disadvantage that the risk of The present invention has been made paying attention to such a point, and an object thereof is to accurately determine incomplete combustion regardless of the difference in the generation state of unburned gas with a rational configuration. In other words, it is possible to provide a combustion device that can perform post-treatment that corresponds to incomplete combustion more reliably.

[0005]

The features of the first invention are as follows:
An unburned gas concentration detection means for detecting the unburned gas concentration in the combustion exhaust gas of the burner, and an incomplete combustion determination means for determining incomplete combustion of the burner based on the detection result of the unburned gas concentration detection means In the combustion apparatus, which is provided with a post-processing executing unit that executes a post-processing corresponding to the incomplete combustion in accordance with the incomplete combustion determining unit determining the incomplete combustion, the incomplete combustion determining unit is The unburned gas concentration detected by the unburned gas concentration detection means is a continuous unburned gas generation state measuring means for measuring the duration of a state in which it exceeds the set value for continuous determination, and the unburned gas concentration detection When the unburned gas concentration detected by the means is higher than when the unburned gas concentration is low, the integrated means for measuring the integrated value of the combustion time is provided, and the unburned gas concentration generation state measuring means measures the value. Succession Time exceeds the set permissible time, and, in that the integrated value of said integrating means is configured to determine as incomplete combustion exceeds an allowable value.

A characteristic configuration of the second invention is to specify a configuration suitable for carrying out the first invention, wherein the integrating means is
The unburned gas concentration is compared with a plurality of high and low determination values set for weighted determination, and the unburned gas concentration is configured to be weighted and integrated so as to exceed the determination value on the high side. There is a point.

A characteristic configuration of the third invention is to specify a configuration suitable for carrying out the first or second invention, which comprises a fuel supply amount adjusting means for adjusting a fuel supply amount to the burner, and a normal combustion state. And a combustion control unit that controls the fuel supply amount adjusting unit so that the fuel supply amount becomes a commanded target fuel supply amount, and the post-processing executing unit corresponds to the incomplete combustion. As post-processing, the combustion control means is configured to limit the combustible fuel supply amount adjustment range.

The characteristic configuration of the fourth aspect of the invention is to specify a configuration suitable for carrying out the first, second or third aspect of the invention, in which ventilation means for passing combustion air to the burner and a normal combustion state are provided. In the above, a combustion control unit that controls the ventilation unit so as to achieve a target ventilation amount that is set based on the target fuel supply amount is provided, and the post-processing execution unit is a post-processing unit that corresponds to the incomplete combustion. The combustion control means is instructed to increase the target ventilation amount.

The characteristic features of the fifth invention are the first, second and third aspects.
Alternatively, the configuration suitable for carrying out the fourth invention is specified, and the post-processing executing means is configured to execute an alarm operation as a post-processing corresponding to the incomplete combustion. .

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 post-processing executing means is the incomplete. The post-treatment corresponding to the combustion is that the combustion of the burner is stopped.

[0011]

According to the characteristic construction of the first aspect of the invention, when the unburned gas concentration exceeds the set permissible time when the unburned gas concentration exceeds the set value for continuous determination, that is, the unburned gas concentration exceeds the set value. When the exceeding state continues, and the duration exceeds the set allowable value, it is determined that the combustion is incomplete, and the post-processing is executed. Therefore, when unburned gas is generated almost continuously due to blockage of the ventilation passage, incomplete combustion is effectively detected, and temporary backflow from outside due to burner draft ventilation is detected. When a high concentration of unburned gas is generated, the duration does not exceed the set permissible value, and there is little risk of being erroneously determined as incomplete combustion.

Further, in the normal combustion state where the unburned gas concentration is low, the integrated value of the combustion time is measured with a small weight, so that the combustion duration can be lengthened, and when the unburned gas concentration is high, a large weight is given. Is added, the integrated value of the combustion time is measured, and when the integrated value exceeds the allowable value, it is determined that the combustion is incomplete, and the post-processing is executed. As a result, for example,
When high-concentration unburned gas is repeatedly generated intermittently, the integrated value exceeds the allowable value in a shorter time than in the case of normal combustion, and it is determined that the combustion is incomplete. Therefore, it is possible to effectively prevent the situation where a high concentration of unburned gas is generated from continuing for a long time.

According to the characterizing structure of the second invention, there is the following function in addition to the function of the characterizing structure of the first invention. The unburned gas concentration is compared with a plurality of judgment values of high and low, and when the judgment value on the high side exceeds the judgment value, the integrated value of the combustion time is measured with a greater weight than that of the judgment value on the low side. Therefore, since the integrated value is measured by the comparison operation of the detected unburned gas concentration and each judgment value, and the weighting corresponding to the comparison result, the deviation between the unburned gas concentration and the set value, etc. is integrated over time. Even when a high concentration unburned gas is temporarily generated, the integrated value does not suddenly become a large value as compared with the case where the integrated value is obtained by calculating.

According to the characterizing feature of the third invention, there are the following effects in addition to the effects of the characterizing feature of the first or second invention.
As the incomplete combustion is discriminated, the post-processing executing means,
The combustion control means is controlled so as to limit the combustible fuel supply amount adjustment range. For example, the maximum target fuel supply amount is reduced, or the maximum target fuel supply amount is decreased and the minimum target fuel supply amount is increased, thereby limiting the combustible fuel supply amount adjustment range.

In other words, unburned gas is generated when the amount of ventilation to the burner decreases from the target ventilation to maintain the proper combustion state with respect to the target fuel supply, so that such ventilation is insufficient. On the other hand, by limiting the adjustment range of the target fuel supply amount, the combustion state of the burner can be set to the proper combustion state as much as possible.

According to the characteristic constitution of the fourth invention, the first and second aspects are provided.
Alternatively, the following operation is provided in addition to the operation according to the characteristic configuration of the third invention. As the incomplete combustion is discriminated, the post-processing execution means instructs the combustion control means to increase the target ventilation amount set based on the target fuel supply amount to the burner, thereby performing the combustion control. The means controls the ventilation means so as to increase the target ventilation amount.

In other words, unburned gas is generated when the amount of ventilation to the burner decreases from the target ventilation to maintain the proper combustion state with respect to the target fuel supply, so that such ventilation is insufficient. On the other hand, by increasing the target ventilation amount, the combustion state of the burner can be made as appropriate as possible.

According to the characterizing feature of the fifth invention, there is the following effect in addition to the effect of the characterizing feature of the first, second, third or fourth invention. When the incomplete combustion is determined, the post-processing executing means alarms, so that the user of the apparatus can immediately recognize that the incomplete combustion state has occurred.

According to the characterizing feature of the sixth invention, there is the following function in addition to the function of the characterizing feature of the first, second, third, fourth or fifth invention. As the incomplete combustion is discriminated, the post-processing executing means stops the combustion of the burner.
Generation of unburned gas is reliably stopped.

[0020]

According to the characteristic constitution of the first invention, in the case where the high-concentration unburned gas is continuously generated, or the high-concentration unburned gas is intermittently generated, etc. Is determined as incomplete combustion, and in a special situation where unburned gas with a very high concentration is temporarily generated, incomplete combustion is not determined and the actual unburned gas According to the situation of occurrence, since the incomplete combustion is accurately determined and the post-processing corresponding to the incomplete combustion is executed, the safety in use is improved.

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. After a high concentration of unburned gas is generated, it is possible to avoid the disadvantage that the device is used continuously for a long time, but after a temporary high concentration of unburned gas is generated. In the case of returning to the normal combustion state, the rapid increase of the integrated value is suppressed, so that the device can be continuously used without being judged as incomplete combustion in a short time.

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.
Even if it is determined that the combustion is incomplete, by limiting the adjustment range of the target fuel supply amount, it is possible to continue using the device while maintaining the burner in the proper combustion state as much as possible.

According to the characteristic configuration of the fourth invention, the first and second
Alternatively, there are the following effects in addition to the effects of the characteristic configuration of the third invention. Even if it is determined that the combustion is incomplete, by increasing the target ventilation amount, it is possible to continue using the device while maintaining the burner in the proper combustion state as much as possible.

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 first, second, third or fourth invention. If it is judged as incomplete combustion,
Since the user of the apparatus can immediately recognize that the incomplete combustion has occurred, the user of the apparatus can be prompted to perform subsequent treatment such as ventilation of the room or maintenance processing, and safety is ensured.

According to the characterizing structure of the sixth invention, the following effect is obtained in addition to the effect of the characterizing structure of the first, second, third, fourth or fifth invention. If it is determined that the combustion is incomplete, the combustion of the burner is stopped so that unburned gas is not generated. Safety can be secured because subsequent treatment such as ventilation and maintenance processing can be promoted.

[0026]

Embodiments will be described below with reference to the drawings. Figure 1
FIG. 1 shows a hot water supply device as an example of a combustion device according to the present invention. This hot water supply device includes a water heater A, a controller H that controls the operation of the water heater A, and a control state to the controller H. , And an operation unit R for performing various displays.
The water heater A is connected to the combustion chamber 1, a burner 2 provided inside the combustion chamber 1, a heat exchanger 3 for heating water to be heated by the burner 2, and an upper part of the combustion chamber 1, and the burner is connected to the burner 2. 2, an exhaust passage 5 for discharging the combustion gas to the outside of the room, and a fan 4 as a ventilation means for supplying combustion air to the burner 2 and ventilating the combustion gas in the burner 2 to the outside through the exhaust passage 5. A water supply path 6 for supplying heating water to the heat exchanger 3, a hot water supply path 7 for supplying hot water heated in the heat exchanger 3 to a hot water tap (not shown), and a fuel for the burner 2. It is composed of a fuel supply passage 8 for supplying (gas). In the vicinity of the burner 2, an igniter 9 for ignition and a frame rod 10 for detecting whether or not the burner 2 has ignited.
And are provided.

The water supply passage 6 is provided with a water supply amount sensor 11 for detecting the amount of water supplied to the heat exchanger 3 and an incoming water temperature sensor 12 for detecting the incoming water temperature, and the hot water supply passage 7 is provided with hot water for a hot water tap. A hot water supply temperature sensor 13 that detects the temperature is provided. Further, the fuel supply passage 8 is provided with an opening / closing valve 14 for connecting and disconnecting the fuel supply to the burner 2 and an electromagnetic proportional valve 15 as a fuel supply amount adjusting means for adjusting the fuel supply amount.

A filter (not shown) for removing dust is provided at the intake of the combustion air by the fan 4, and a filter switch 17 for detecting whether or not the filter is attached is provided. There is.

The operation unit R is connected to the control unit H by wire or wirelessly, and displays an operation switch 19 for instructing start and stop of operation of the hot water supply device, a temperature setting switch 20 for setting a set target hot water supply temperature, and a hot water supply temperature. Temperature display 2
1, operation indicator lamp 2 that indicates whether or not the vehicle is in an operating state
2. Abnormality display lamp 23 for displaying an abnormality as described later
a, 23b, etc. are provided.

The exhaust passage 5 is an example of unburned gas concentration detecting means for detecting the concentration of carbon monoxide (hereinafter referred to as CO concentration) as an example of unburned gas contained in the combustion gas of the burner 2. A CO sensor S is provided. Figure 2
The configuration of the CO sensor S is shown. The CO sensor S is equipped with a sensor element 26 and a temperature compensation reference element 27 on a pedestal 25 inside a stainless steel protective frame 24. The sensor element 26 and the temperature compensating reference element 27 are each composed of a platinum wire tanned with a catalyst, and are heated to about 200 ° C. by the flow of an electric current, and the unburned gas in the combustion gas contacting the surface thereof is heated. The components burn catalytically. At this time, since the catalyst tangled in the sensor element 26 has selectivity for CO, a difference occurs between the element temperatures. Since the resistance value of the platinum wire changes depending on the temperature, when the CO concentration in the combustion gas becomes large, the sensor element 26 and the temperature compensating reference element 2 are used.
The difference between the resistance values of 7 becomes large. Therefore, CO in the combustion gas
The concentration CO can be detected as a difference in resistance value (sensor output V). Reference numeral 28 in the drawing is a connector portion with a lead wire connected to the control portion H. Figure 3
The output V of the CO sensor S with respect to the CO concentration in the combustion gas
Indicates.

The control unit H includes the sensors 11, 1
2 and 13 and the detection information of the frame rod 10 are input, and the burner 2 is controlled by controlling the igniter 9, the on-off valve 14, the solenoid proportional valve 15, the fan 4, etc. based on the detection information of these sensors. Based on the detection result of the combustion control means 100 for controlling the combustion state of
Incomplete combustion determination means 1 for determining incomplete combustion of the burner 2
01, and a post-processing execution means 102 that executes a post-processing corresponding to the incomplete combustion when the incomplete combustion determination means 101 determines the incomplete combustion.

When the hot water supply tap is opened and the water supply amount detected by the water supply amount sensor 11 reaches the set water amount, the controller H starts ignition by the igniter 9 to start the hot water supply operation, and the water supply amount is the set water amount. When it becomes less than, the fuel supply to the burner 2 is stopped and the hot water supply operation is stopped.

When the hot water supply operation is started, the combustion control means 100 is set by the water supply amount detected by the water supply amount sensor 11, the water inlet temperature detected by the water inlet temperature sensor 12, and the temperature setting switch 20 of the operating portion R. The target fuel supply amount Ip of the burner 2 is obtained from the preset characteristics on the basis of the information such as the set target hot water supply temperature that has been set, and the actual fuel supply amount is set to the target fuel supply amount Ip by the electromagnetic force. The proportional valve 15 is feed-forward-controlled, and the electromagnetic proportional valve 15 is feedback-controlled so that the hot water supply temperature detected by the hot water supply temperature sensor 13 reaches the set target hot water supply temperature to adjust the fuel supply amount to the burner 2.

Further, the rotational speed of the fan 4 is determined with respect to the target fuel supply amount Ip, for example, as shown by a characteristic line L1 in FIG. The rotation speed of the fan 4 is controlled so that the air flow rate becomes equal to), and the combustion control is executed so that an appropriate burner combustion state is achieved.

The incomplete combustion discriminating means 101 serves as a continuous unburned gas generation state measuring means for measuring the duration of the state where the CO concentration CO detected by the CO sensor S exceeds the continuous set value. The first continuous timer TM1 and the second continuous timer TM2, and the CO concentration CO detected by the CO sensor S are compared with the high and low two-stage determination values,
The first continuous timer TM1 and the second continuous timer TM2 are provided with an integration timer TMs serving as an integration unit that measures the integrated value of the combustion time by weighting more as the CO concentration CO exceeds the higher judgment value. When the measured duration exceeds the set allowable time and the integrated value of the integration timer TMs exceeds the allowable value, it is determined that the combustion is incomplete.

When the incomplete combustion discriminating means 101 discriminates the incomplete combustion, the post-processing executing means 102 activates each of the abnormality indicating lamps 23a and 23b as an alarm operation and supplies the combustible fuel. The combustion control means 100 is instructed to limit the amount adjustment range.

The control operation of the control unit will be described below with reference to FIGS.
Description will be made based on the flowchart shown in FIG. 7. When the operation switch 19 is turned on and the water supply amount detected by the water supply amount sensor 11 exceeds the set amount in accordance with the opening operation of the hot water tap, the ignition control for the burner 2 is executed (steps 1 to 3). That is, the on-off valve 14 is opened, the solenoid proportional valve 15 is controlled to reach the target fuel supply amount, the burner 2 is ignited by the igniter 9, and the ignition is detected by the frame rod 10, the igniter is detected. The ignition operation of 9 is stopped.

Then, C detected by the CO sensor S
When the reading of the O concentration CO (CO measurement) is started (step 4), and if the CO concentration CO is less than 1000 ppm (normal combustion state), addition of the integration timer TMs is performed, and the first continuous timer TM1 and the second continuous timer TM1 are also added. The continuous timer TM2 is reset (steps 5-8). At this time, the weight of the integration timer TMs is set to "1". When the time exceeds the allowable value (about 60 minutes) set by the integration timer TMs, the combustion is stopped and the abnormality display lamp 23a is lit and displayed (steps 9 to 11). Then, post-purging (ventilation operation by a fan) is performed for 10 minutes (step 12). Then, when the reset operation is performed by the OFF / ON operation of the operation switch 19 or the closing / opening operation of the hot water tap, the process returns to step 1 (step 13).

Next, if the CO concentration CO is 1000 ppm or more and less than 2000 ppm, the integration timer TMs
Is multiplied by "N"("N" is a value larger than 1), and addition is performed by the integration timer TMs (steps 6, 14 to 16). Therefore, the integrated time until the integrated value exceeds the allowable value becomes shorter than that in the normal combustion state. The first continuous timer TM1 is added and the second continuous timer TM2 is reset (step 17). When the first continuous timer TM1 times out (about 20 seconds) before the integrated value of the integrated timer TMs exceeds the allowable value, that is, C
When the O concentration CO is 1000 ppm or more and less than 2000 ppm continuously for 20 seconds or more, it is determined that the combustion is incomplete, and the maximum target fuel supply amount in the adjustment range of the target fuel supply amount Ip is decreased by the set amount ΔIp. To limit the combustible fuel supply amount adjustment range (step 18
21). Specifically, the characteristic line L1 of the target rotational speed with respect to the target fuel supply amount Ip shown in FIG. 4 is changed to a characteristic line L2 that decreases by the set amount ΔIp.

Then, the first continuous timer TM1 is reset, the abnormality display lamp 23b is turned on (steps 22 and 23), the CO concentration CO as described above is read again, and the judgment value is compared. Even after the target fuel supply amount limit control is executed, the CO concentration CO remains 1000
When the first continuous timer TM1 is timed out (continues for 20 seconds or more) since it is at least ppm and less than 2000 ppm, it is determined that the incomplete combustion has not been resolved, the combustion is stopped, and the abnormality display lamp 23a is lit and displayed ( Step 4
~ 6, 14-19, 24-28). Then, post-purging (ventilation operation by a fan) is performed for 10 minutes (step 27). Then, when the reset operation is performed by the OFF / ON operation of the operation switch 19 or the closing / opening operation of the hot water tap, the process returns to step 1 (step 28). In step 18, if the integrated value of the integration timer TMs exceeds the allowable value by the time the first continuous timer TM1 times out, it is determined that the combustion is incomplete, and the process proceeds to step 25 to stop the combustion. , Steps 25-28.

When the unburned gas concentration CO becomes 2000 ppm or more, the integration timer TMs is weighted "M" times ("M" is a value larger than "N"), and the integration timer Ts is weighted.
The addition by Ms is performed, and the addition of the second continuous timer TM2 is performed (steps 14, 29 to 31). Therefore, the integration time until the integrated value exceeds the allowable value is CO concentration CO
Is 1000 ppm or more and less than 2000 ppm, which is even shorter.

If the integrated value of the integrated timer TMs does not exceed the allowable value and the second continuous timer TM2 times out (several seconds), that is, if the state of CO concentration CO of 2000 ppm or more continues for several seconds or more, the error occurs. It is determined that the combustion is complete, and the target fuel supply amount limiting control as described above is executed (steps 32 to 35). While resetting the second continuous timer TM2, the abnormality display lamp 23b is turned on (steps 36 and 37), the unburned gas concentration CO as described above is read again, and the determination value is compared to perform target fuel supply. Even after the amount limit control is executed, the CO concentration CO
Is 2000 ppm or more, and when the second continuous timer TM2 times out (continues for several seconds or more) in that state, it is determined that the incomplete combustion has not been resolved, the combustion is stopped, and the abnormality display lamp 23a blinks ( Steps 4-6
14, 29-33, 38-40). After that, post-purging (ventilation operation by a fan) is performed for 10 minutes, and interlock control is performed for 4 hours (steps 41 and 42).

When the interlock control is executed,
When any switch of the operation unit R is operated, no operation is performed and combustion is not started. Therefore, the user of the hot water supply device can recognize that the maintenance process is necessary.

After the interlock control is completed, if the reset operation is performed by turning the operation switch 19 off / on or by closing / opening the hot water tap, the process returns to step 1 (step 43). In step 32, if the integrated value of the integration timer TMs exceeds the allowable value by the time the second continuous timer TM2 times out, it is determined that the combustion is incomplete, and the process proceeds to step 39 to stop the combustion. , Steps 39-43.

Therefore, the above 1000 ppm, 2000 p
pm correspond to the respective judgment values for the weighting judgment, and the integration timer TMs weights and integrates more as the judgment value on the higher CO concentration CO side increases, and when the CO concentration CO is high. The integrated time until the allowable value is exceeded becomes short, and the time during which continuous combustion is possible becomes short.

For example, a back wind from the outside is blown to the exhaust port of the exhaust passage 5, the ventilation to the burner 2 is temporarily reduced, and the CO concentration CO temporarily becomes a very high value. Even in this case, since the weight of the integration timer TMs is set to the above "M", the integrated value does not exceed the allowable value immediately after it suddenly increases, and the CO concentration CO
Unless the high state continues for a set time or longer, it is not determined as incomplete combustion.

When the hot water tap is closed during the hot water supply operation,
Combustion of the burner 2 is stopped and CO concentration C immediately before the combustion is stopped
If O is less than 1000 ppm, integration timer TM
s, the first continuous timer TM1 and the first continuous timer TM2 are reset, and post-purge is performed for 75 seconds (steps 5, 44 to 47). When the CO concentration CO is 1000 ppm or more, the timers TM1 and TM2 are reset and post-purging is performed for 5 minutes (steps 48 and 4).
9).

If the abnormality display lamp 23b is turned on, that is, if the target fuel supply amount Ip is controlled to decrease, the filter switch 17 is turned off / on.
If it is determined that the filter is removed and the clogging cleaning operation is being performed from the switching state of No. 3, the abnormality display lamp 23b is turned off, and the target fuel supply amount is returned from the reduced state to the original set value. (Steps 50-53).
Even after the filter is cleaned, if the incomplete combustion is determined by a cause other than the filter clogging, the target fuel supply amount limit control and the combustion stop control as described above are executed. It will be.

[Other Embodiments] (1) In the above embodiment, the integrating timer T as the integrating means is used.
As the judgment value for weighting Ms, two judgment values of high and low (1000 ppm, 2000 ppm) are used. However, the judgment value is not limited to two, and the integration timer TMs is based on three or more judgment values. May be weighted, or the weight may be continuously changed based on a preset characteristic so that the larger the unburned gas concentration CO, the greater the weight. (2) In the above-described embodiment, the continuous unburned gas generation state measuring means is the first continuous timer TM1 and the second continuous timer TM2.
It is composed of three timers, and as the set value for continuous judgment,
Although the two judgment values for weighting of the integration timer TMs are used, a value different from the weighting judgment value of the integration timer TMs may be set and measured as the continuous judgment set value. Good. (3) In the above embodiment, the case where the number of the burners is one was illustrated, but instead of such a configuration, it may be configured as shown in FIG. That is, a plurality of burners (two cases are shown in FIG. 8) are provided, and the branch supply paths 8a and 8b for the respective burners are provided with the on-off valves 14a and 4b and the solenoid proportional valves 15a and 15b, respectively, to establish a combustion state. The number of combustion burners is switchable, and the control unit H
The number of combustion burners is controlled so as to increase as the target fuel supply amount increases. In FIG. 8, MB is a main gas valve. In this case, the characteristic line indicating the target rotation speed (ventilation amount) of the fan with respect to the target fuel supply amount is, as shown in FIG. 9, a characteristic line L3 for one combustion burner and a characteristic line L3 for two combustion burners. Since there are two characteristic lines including the characteristic line L4, the required ventilation amount per unit area of the burner is the same regardless of switching of the number of combustion burners, so the maximum target fuel supply amount is the combustion burner. The same value is obtained whether the number is 1 or 2.

In such a structure, when the incomplete combustion is discriminated, the number of combustion burners is switched in a state where all the plurality of burners (two in the example shown in FIG. 8) are burned. The control may be stopped, and the maximum target fuel supply amount may be decreased by a predetermined amount (ΔIp) to limit the adjustment range of the fuel supply amount, as indicated by a characteristic line L5 in FIG. 9. In this case, since the switching control of the number of combustion burners is stopped, the maximum target fuel supply amount decreases and the minimum target fuel supply amount increases in the fuel supply amount adjustment range by executing the limit control. It will be.

The number of burners may be three or more,
The branch supply passage for each burner may be provided with only an on-off valve, and the combustion supply passage 8 may be provided with one electromagnetic proportional valve. (4) In the above-described embodiment, the target fuel supply amount is reduced by the set amount as the post-processing for the incomplete combustion, but the target fuel supply amount may be reduced by a small number of times. . (5) In the above embodiment, as the post-processing corresponding to the incomplete combustion, the alarm operation is executed with the decrease of the target fuel supply amount, but only one of them may be executed. (6) In the above-described embodiment, the target fuel supply amount is reduced as the post-treatment for incomplete combustion, but the ventilation amount by the ventilation means (fan) may be increased. (7) In the above embodiment, as the unburned gas concentration detecting means,
CO sensor S for detecting the concentration of carbon monoxide in combustion gas
However, the concentration of hydrogen gas (H ₂ ) or other unburned gas may be detected as the unburned gas in the combustion gas.

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 schematic configuration diagram of a CO sensor.

FIG. 3 is an output characteristic diagram of a CO sensor

FIG. 4 is a characteristic diagram showing a target rotation speed with respect to a target fuel supply amount.

FIG. 5 is a flowchart of control operation

FIG. 6 is a flowchart of control operation

FIG. 7 is a flowchart of control operation

FIG. 8 is a schematic configuration diagram of a hot water supply device according to another embodiment.

FIG. 9 is a characteristic diagram showing a target rotational speed with respect to a target fuel supply amount of another embodiment.

[Explanation of symbols]

 2 burner 4 ventilation means 15 fuel supply amount adjustment means 100 combustion control means 101 incomplete combustion determination means 102 post-processing execution means S incomplete combustion detection means TM1, TM2 continuous unburned gas generation state measurement means TMs integration means

Claims (6)

[Claims] 1. An unburned gas concentration detecting means (S) for detecting an unburned gas concentration in a combustion exhaust gas of a burner (2), and based on a detection result of the unburned gas concentration detecting means (S), Incomplete combustion determination means (101) for determining incomplete combustion of the burner (2) and post-processing corresponding to incomplete combustion as the incomplete combustion determination means (101) determines incomplete combustion. A post-processing execution means (102) for executing the combustion apparatus, wherein the incomplete combustion determination means (101) is configured to detect the unburned gas concentration detected by the unburned gas concentration detection means (S). , A continuous unburned gas generation state measuring means (TM) for measuring the duration of the state in which the set value for continuous determination is exceeded.
1), (TM2), and when the unburned gas concentration detected by the unburned gas concentration detecting means (S) is high, the integrated value of the combustion time is measured with a greater weight than when it is low. An unburned gas concentration generation state measuring means (TM1), (TM)
The duration measured in 2) exceeds the set allowable time,
And a combustion device configured to determine that the combustion is incomplete when the integrated value of the integrating means (TMs) exceeds an allowable value. 2. The integrating means (TMs) compares the unburned gas concentration with a plurality of high and low determination values set for weighting determination, and exceeds the determination value on the high unburned gas concentration side. The combustion apparatus according to claim 1, wherein the combustion apparatus is configured to be added with a larger weight. 3. A fuel supply amount adjusting means (15) for adjusting a fuel supply amount to said burner (2), and said fuel supply amount so as to become a commanded target fuel supply amount in a normal combustion state. A combustion control means (100) for controlling the fuel supply amount adjusting means (15) is provided, and the post-processing execution means (102) is the combustion control means (100) as a post-processing corresponding to the incomplete combustion. 3. The combustion device according to claim 1, wherein the combustion device is configured to limit a combustible fuel supply amount adjustment range. 4. A ventilating means (4) for ventilating combustion air to said burner (2), and said ventilating means (4) so as to attain a target airflow rate set based on a target fuel supply rate in a normal combustion state. 4) is provided for controlling the combustion control means (100), and the post-processing execution means (102) provides the combustion control means (100) with the target ventilation amount as post-processing corresponding to the incomplete combustion. The combustion device according to claim 1, 2 or 3, wherein the combustion device is configured to command an increase in the. 5. The combustion apparatus according to claim 1, 2, 3 or 4, wherein the post-processing executing means (102) is configured to execute an alarm operation as a post-processing corresponding to the incomplete combustion. . 6. The post-processing executing means (102) is configured to stop combustion of the burner (2) as a post-processing corresponding to the incomplete combustion. The combustion device according to 4 or 5.