JPH09196364A - Combustion equipment - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To understand the cause of abnormal combustion and to take appropriate measures corresponding to the cause of abnormal combustion in a combustion device that detects normal / abnormal combustion state of a burner. A combustion device is provided. An abnormality determination unit 13 includes a combustion state monitoring unit 11.
If it is determined that the combustion is abnormal based on the flame (FR) current detection value from the engine and the air amount detection value from the air flow monitoring unit 12 is normal, the combustion of the burner is immediately stopped through the combustion stopping unit 15 as abnormal combustion due to oxygen deficiency. Let Then, the user is warned to that effect. On the other hand, when it is determined that the combustion is abnormal due to insufficient air amount, it is checked whether the detected air amount value is smaller than a predetermined threshold value. As a result, if it is large, it is possible to shift to normal combustion by eliminating the insufficient air amount, so the fan drive unit 30 is controlled to increase the air supply amount to the burner. If it is smaller than the threshold value, it is difficult to solve the shortage of the air amount due to the increase of the fan rotation speed. Therefore, the supply amount of the gas fuel to the burner is limited, and the combustion amount is controlled so as to match the air supply amount. , And informs the user to that effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a combustion device that executes an operation such as stopping combustion when the combustion state of a burner is detected and abnormal combustion is determined. In this specification, a combustion device mainly applied to a water heater for supplying hot water to a bathtub, hot water to a faucet, or the like will be described as an example.

[0002]

2. Description of the Related Art Conventionally, in a combustion apparatus using gas fuel, when the flame current value of the burner detected by the flame current detection means (frame rod, etc.) exceeds a predetermined threshold value, it is judged as abnormal combustion and the combustion operation is performed. A device for stopping is known (see JP-A-59-145422). Also,
The current detection circuit detects the drive current value of the fan that supplies air to the burner, and the rotation speed detector detects the rotation speed of the fan, and detects abnormalities based on the results of comparison between these detected values and a predetermined reference value. A device for stopping the combustion operation when it is determined to be combustion is also known (Japanese Patent Laid-Open No. 5-196229).
Reference).

[0003]

Generally, the above-mentioned abnormal combustion includes abnormal combustion due to oxygen deficiency (hereinafter referred to as "oxygen deficiency") and abnormal combustion due to insufficient air supply to the burner.

Abnormal combustion due to oxygen deficiency is usually caused by the mixture of exhaust gas containing a large amount of CO and the like in the air-fuel mixture (composed of gas fuel and primary air) supplied to the burner. The cause is different for each device such as an indoor air supply / exhaust type, an outdoor air supply / exhaust type, an indoor air supply / exhaust type, and an outdoor installation type device. For example, an indoor air supply / exhaust type device may be used for a long time, an indoor air supply / exhaust type device may mix exhaust gas into the room due to a defective exhaust stack, and an outdoor air supply / exhaust type device may mix exhaust gas into the supply cylinder. However, they cause abnormal combustion due to oxygen deficiency. Also,
In equipment installed outdoors, the mixture of exhaust gas into the air supply causes abnormal combustion due to oxygen deficiency. When such abnormal combustion due to oxygen deficiency occurs, it is necessary to immediately stop the combustion operation.

On the other hand, abnormal combustion due to insufficient air supply is
Usually, the air supply filter installed in the air inlet that introduces air into the burner is clogged, and the heat-absorbing fins of the heat exchanger (which heats the hot water flowing in by the heat from the burner), heating pipes, and exhaust ports. It is caused by the blockage of exhaust gas caused by the attachment of soot to etc. In this case, it is possible to continue the combustion operation by increasing the fan rotation speed to increase the air supply amount to the burner.

However, in the device of the above-mentioned Japanese Patent Laid-Open No. 59-145422, based on the result of comparison between the simply detected flame current value and the threshold value for judging normal / abnormal of the combustion state,
When the abnormal combustion is determined, the combustion stop control is only performed, and the cause of the abnormal combustion cannot be accurately grasped. Further, in the apparatus of the above-mentioned Japanese Patent Laid-Open No. 5-196229,
It only detects the fan driving current value and the fan rotation speed to determine the degree of soot adhesion to the heat exchanger, and does not detect the combustion state. As described above, in any of the above devices, the cause of abnormal combustion could not be accurately grasped.

Therefore, an object of the present invention is to make it possible to grasp the cause of abnormal combustion and to take appropriate measures in response to the cause of abnormal combustion in a combustion device that detects normal / abnormal combustion conditions of a burner. To provide a simple combustion device.

[0008]

A combustion apparatus according to the present invention supplies fuel and air to a burner for combustion, and includes a determination means for determining abnormality in a combustion state and an abnormality cause, and a determined abnormality cause. And a treatment executing means for executing the treatment according to the above.

In the preferred embodiment of the present invention, the cause of the abnormality is insufficient air supply to the burner and oxygen deficiency of the air supplied to the burner. The determination means of this embodiment determines the cause of abnormality from a plurality of state detection values, and these plurality of state detection values are supplied to the burner and the detection value from the combustion state detection means for detecting the combustion state of the burner. The detected value from the air amount detecting means for detecting the amount of air to be discharged.

According to the above construction, the abnormality of the combustion state and the cause of the abnormality are determined based on the detection values from the combustion state detecting means and the air amount detecting means, and the action according to the determined abnormality cause is executed. Therefore, appropriate measures can be taken according to oxygen deficiency or insufficient air amount.

The combustion state detecting means of this embodiment is a flame rod, and the air amount detecting means is a fan drive current detecting circuit. When the detected value of the flame current from the flame rod is larger than the first threshold, which is relatively large, the determination means determines that the abnormality cause is an air amount shortage, and when it is smaller than the second threshold smaller than the first threshold, The cause of abnormality is determined to be oxygen deficiency. The abnormality and the cause of the abnormality are comprehensively determined based on this determination and the fan driving current value from the fan driving current detection circuit. As a result, it is possible to determine whether the cause of the abnormality is the air amount shortage or the oxygen deficiency only by the flame current detection value. Further, accurate combustion control can be performed.

Further, the determination means obtains the thermal efficiency value from the output commanded combustion amount and the actual combustion amount, and when it is determined to be abnormal based on the thermal efficiency value, the determination result is prioritized over the above-mentioned integrated determination result. Let As a result, even if the flame rod or the fan drive current detection circuit fails, abnormal combustion can be reliably detected.

Further, the treatment executing means of this embodiment has a control function for controlling the supply amounts of fuel and air, and the judging means detects that the air amount is normal and the combustion state is abnormal. At this time, the treatment execution means is notified to stop the combustion. According to this configuration, the combustion can be immediately stopped in the oxygen-deficient state, so that the safety of the combustion device can be further improved.

When the amount of air is abnormal and the combustion state is abnormal, the determination means notifies the treatment execution means to control the supply amount of fuel or air so that the combustion state returns to normal. For example, when the degree of abnormality is small, the air amount is increased, and when the degree of abnormality is large, the combustion amount is decreased. With this configuration, it is possible to continue combustion while ensuring the safety of the combustion device.

Further, it is desirable to provide a notifying means for notifying the outside of the judgment result by the judging means. Since the user is informed of the abnormal combustion state by providing the notification means, the user can easily know the details of the abnormality, and the appropriate countermeasure operation according to the cause of the abnormal combustion can be performed. It is possible to improve the sex.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing the overall construction of a combustion apparatus according to an embodiment of the present invention.

The above apparatus includes a combustion state monitoring section 11, an air volume monitoring section 12, an abnormality determination section 13, an alarm section 14, a combustion stopping section 15, a gas volume limiting section 16, and an air volume increasing section 17. Prepare The combustion state monitoring unit 11 monitors the combustion state of the burner (reference numeral 21 in FIG. 2). The air volume monitoring unit 12 monitors the amount of air supplied to the burner 21. The abnormality determination unit 13
Based on the outputs from the combustion state monitoring unit 11 and the air volume monitoring unit 12, the normal / abnormal combustion state of the burner 21 and the cause of the abnormal combustion state of the burner 21 are determined. Notification unit 1
Reference numeral 4 indicates the determination result by the determination unit 13 in a form (image information or audio information) that can be grasped by the user. The combustion stopping unit 15 determines the burner 21 based on the determination result of the determining unit 13.
To stop the combustion operation. The gas amount limiting unit 16 limits the amount of gas fuel supplied from the gas supply source based on the result of the determination by the determining unit 13. The air volume increasing unit 17 increases the air supply amount to the burner 21 based on the determination result of the determining unit 13.

The combustion state monitoring unit 11 is
A flame current detector (frame rod) that detects the flame current of the burner 21, a CO concentration sensor that detects the CO concentration of the burner 21, a combustion temperature sensor that detects the combustion temperature of the burner 21, or the exhaust gas from the burner 21 An exhaust gas temperature sensor that detects the temperature is used. Further, the air flow monitoring unit 12 includes a fan drive current detection circuit that detects a fan drive current value when the fan rotation speed is a constant value, and a rotation speed detector that detects a fan rotation speed when the fan drive voltage is a constant value. A hot-wire anemometer type or pressure gauge type wind velocity sensor or the like is adopted.

In the above structure, the combustion state information from the monitoring unit 11 and the air supply amount information from the monitoring unit 12 are both sent to the determination unit 13. In the determination unit 13, these 2
If it is determined based on the type information that the combustion state is abnormal and the air supply amount is normal (that is, the air supply amount detection value is larger than a predetermined first threshold value for determining that the air supply amount is insufficient), the acid The combustion operation of the burner 21 is stopped through the combustion stopping unit 15 by determining that the combustion is abnormal due to lack. Then, the determination result and the content of the processing operation are notified to the user from the determination unit 13 through the notification unit 14 simultaneously with the stop of the combustion operation.

Next, when it is determined that the combustion state is abnormal and the air supply amount is insufficient (that is, the air supply amount detection value is smaller than the above-mentioned first threshold value) based on the above two types of information, the determination unit 13 checks whether or not the air supply amount detection value is larger than a predetermined second threshold value. Here, the second threshold is for discriminating whether the degree of the air amount shortage is large or small, and is a value smaller than the first threshold. As a result of this check, if it is determined that the air supply amount is larger than the second threshold value, it is determined that the transition to the normal combustion state is possible by increasing the air supply amount, and the determination unit 13
Increases the amount of air supplied to the burner 21 through the air volume increasing unit 17. In this case as well, the determination result and the content of the processing operation are notified to the user from the determination unit 13 through the notification unit 14 at the same time when the control of increasing the air supply amount is started.

On the other hand, as a result of the above check, if it is determined that the detected air supply amount value is smaller than the second threshold value, the determination unit 1
3 is to supply gas fuel from the gas supply source to the burner 21 through the gas amount limiting unit 16 in order to judge that it is difficult to shift to the normal combustion state by increasing the air supply amount and to attempt to shift to the normal combustion state by combustion restriction. Let the amount be limited. Also in this case, the determination result and the contents of the processing operation are notified to the user from the determination unit 13 through the notification unit 14 at the same time as the start of the restriction of the gas fuel supply amount.

FIG. 2 is a block diagram showing an example of the structure of a combustion apparatus when the flame current detector is used in the combustion state monitor 11 and the fan drive current detection circuit is used in the air flow monitor 12 described above.

The above-mentioned apparatus includes a burner 21 and an insulating member 23.
The frame rod 24, the FR current detector 25, the AC power supply 26, the amplifier 27, the controller 28, the fan 29, the fan drive unit 30, and the fan drive current detection circuit 31. The burner 21 burns a mixture of air from the outside air suction fan 29 and gas fuel from a gas supply source (not shown) to blow out a flame 22. The flame rod 24 is supported by the insulating member 23 for detecting a flame current, and faces the flame outlet of the burner 21. The AC power supply 26 forms a closed loop with the flame rod 24, the burner 21, etc. through the flame 22, and supplies power to this closed loop. The FR current detector 25 is connected to detect the frame rod current (FR current) flowing through this closed loop. The amplifier 27 amplifies the output signal from the detector 25 and outputs it. The fan 29 is a fan drive unit 30.
Driven by The fan drive current detection circuit 31 is
The fan drive current flowing through the fan drive unit 30 is detected and output to the controller 28. The controller 28 performs predetermined arithmetic processing operations (each processing operation indicated by reference numerals 13 to 17 in FIG. 1) based on the output from the amplifier 27 and the output from the current detection circuit 31.

The controller 28 compares the output from the amplifier 27 with the threshold value a'in the table of the FR current-CO concentration characteristics stored beforehand (see FIG. 3: determined for each number of combustion amount), Based on the comparison result, it is determined whether the combustion state is abnormal or not, and the combustion of the burner 21 is stopped or the combustion amount is limited. This threshold value a 'is the value of C at which abnormal combustion is determined.
This is the FR current value corresponding to the O concentration value a (for example, 1000 ppm).

The FR current-CO concentration characteristic curve in FIG. 3 is for determining abnormal combustion due to an increase in CO concentration (that is, oxygen deficiency).

The controller 28 is a table of the output from the current detection circuit 31 and the fan drive current-air amount characteristic stored in advance (see FIG. 4: determined for each number of combustion amount).
Are compared with the threshold values b ′ and c ′. Then, based on the comparison result and the comparison result between the FR current and the threshold value a ′,
The determination of oxygen deficiency, insufficient air amount “medium”, and insufficient air amount “large” is made (see FIG. 6).

The sequence of the processing operation for the above determination of the controller 28 will be described in detail with reference to FIG. 5, and the processing content will be described in detail with reference to FIG.

FIG. 4 is a table showing the fan drive current-air amount characteristics when the rotation speed of the fan 29 is constant. This table shows not only the relationship between the fan drive current value and the air amount, The relationship between these and the CO concentration value is also shown. That is, the table clearly shows that when the fan drive current value (fan rotation speed) increases, the amount of air flowing into the burner 21 increases, and conversely, the CO concentration decreases.

In FIG. 4, reference numeral b'denotes a CO concentration value b (for example, 10 when determining whether normal combustion or abnormal combustion occurs).
00 ppm). This value b 'is a threshold value (the above-described first threshold value) for determining whether the air supply amount to the burner 21 is normal or abnormal. The symbol c 'is a CO concentration value c (for example, 2000 ppm) for determining whether the degree of abnormal combustion is large or small.
Is a fan drive current value corresponding to. That is, this value c 'is a threshold value (the above-described second threshold value) for determining whether the degree of the shortage of the air supply amount is large or small.

Next, a first example of the processing operation of the controller 28 described above will be described with reference to the flowchart of FIG.

First, it is checked whether or not the FR current value detected by the combustion state monitoring unit 11 (that is, the FR current detector 25) is smaller than the threshold value a'in FIG. ] (Step S1). At this stage, it is unclear whether the cause of the abnormal combustion is due to lack of oxygen or air shortage for the reasons described above. Next, it is checked whether or not the air amount detected by the air amount monitoring unit 12 is smaller than a first threshold value b '(step S).
2). As a result, if it is determined that it is not small (that is, the air amount is normal), it is determined that the cause of abnormal combustion is "oxygen deficiency" (the determination result indicated by reference numeral (1) in FIG. 6) (step S
3) Immediately stop combustion to ensure the safety of the user (step S4). Then, the user is warned in a predetermined manner (image information, voice information, buzzer, etc.) that the combustion is abnormal due to lack of oxygen (step S5).

On the other hand, if it is determined that the detected air amount is smaller than the first threshold value b '(that is, the air amount is insufficient) (steps S2 and S6), then it is determined whether the air amount is smaller than the second threshold value c'. It is checked (step S7). As a result,
If it is determined that it is not small (that is, the lack of the air amount is medium; the determination result indicated by the reference numeral (2) in FIG. 6), it is determined that the combustion can be shifted to normal combustion by solving the lack of the air amount, and the fan is driven. The section 30 is controlled to increase the amount of air supplied to the burner 21 (step S8).

When it is determined that the detected air amount is smaller than the second threshold value c '(the determination result indicated by the reference numeral (3) in FIG. 6) (step S7), the air supply filter is clogged or heat exchange is performed. It is conceivable that the air introduction part is significantly blocked due to the soot clogging of the vessel and the degree of lack of the air amount is large. Therefore, it is determined that it is difficult to solve the shortage of the air amount due to the increase in the fan rotation speed. Therefore, the supply amount of the gas fuel to the burner 21 is limited, and the combustion amount of the burner 21 becomes the air supply amount. It is controlled to match (step S9). Then, since the combustion is abnormal combustion with a large degree of insufficient air amount, the burner 21 with the combustion amount being limited (for example, the number of combustion amount is reduced from 20 to 10).
The fact that the combustion operation of No. 2 is continued is notified in a form that the user can grasp, such as image information or audio information (step S
10).

If it is determined in step S1 that the FR current value is larger than the threshold value a'in FIG. 3, it is "normal combustion" (the determination result indicated by reference numeral (4) in FIG. 6), which is a problem. There is no.

As described above, according to one embodiment of the present invention, it is possible to determine whether the cause of abnormal combustion is oxygen deficiency or insufficient air amount, and it is determined that abnormal combustion is due to oxygen deficiency. When this happens, the combustion is immediately stopped, so that it is possible to ensure sufficient safety for the user. Also,
When it is determined that the abnormal combustion is due to the shortage of the air amount, it is possible to grasp whether the degree of the shortage of the air amount is large or small, and when the degree of the shortage of the air amount is small, the normal combustion is performed by increasing the air supply amount to the burner 21. Is possible,
Usability is improved. On the other hand, when the degree of insufficient air amount is large, the supply amount of gas fuel to the burner 21 is limited so that the combustion amount of the burner 21 is controlled to match the air supply amount, and the burner 21 is controlled with the combustion amount limited. Since the combustion operation can be continued, the usability is improved. When the combustion is stopped due to lack of oxygen, a warning is issued to the user, and the combustion operation of the burner 21 is continued in a state where the amount of combustion is restricted due to a large degree of insufficient air amount. In such a case, the user is notified to that effect, so that the user can easily grasp the cause of the stop of combustion and the restriction of combustion.

Here, in the above-mentioned FR current, the proportion of the fuel gas in the air-fuel mixture in the mixture of the fuel gas and the air due to the decrease in the air supply amount to the burner 21 due to the heat exchanger blockage (so-called insufficient air amount). When the temperature rises, there is a property that the value increases because the combustion speed increases. Further, in the FR current, when the O2 concentration in the atmosphere decreases, the combustion reaction itself decreases due to O2 deficiency (so-called oxygen deficiency) even if the amount of air supplied to the burner does not change. There is also the property that the value decreases.

In another embodiment of the present invention described below, when the combustion device is in an abnormal combustion state, one of the means for identifying the cause is that the above-mentioned FR current characteristic is the fan drive current. It is used together with the detection value and the thermal efficiency value.

That is, in another embodiment of the present invention, only the FR current value is set by setting a threshold value for determining abnormal combustion due to insufficient air amount and a threshold value for determining abnormal combustion due to oxygen deficiency. It is possible to identify the types of abnormal combustion (air shortage, oxygen deficiency). Further, in the above-described another embodiment, the controller 28 determines whether the combustion state is normal / abnormal or abnormal based on the FR current value and the fan drive current detection value for determining whether the fan speed is normal or abnormal (blocking). The cause of combustion, etc. is determined in an integrated manner. Furthermore,
In the another embodiment, apart from the integrated determination, for example, it is checked whether or not the combustion is abnormal based on a thermal efficiency value (actual combustion number / output combustion number) obtained from a ratio of the output combustion number and the actual combustion number. However, when it is determined that the combustion is abnormal, the determination is prioritized over the result of the integrated determination and the predetermined processing is executed.

FIG. 7 shows an FR according to another embodiment of the present invention.
It is explanatory drawing which shows the determination logic of the combustion state by a current detection value and a fan drive current detection value, and the content of the treatment according to a determination result, Therefore, the content of the integrated determination based on FR current value and a fan drive current detection value is shown. Has been done. However, illustration of the process of checking whether the combustion is abnormal based on the thermal efficiency value (actual combustion number / output combustion number) is omitted.

According to the FR current detection value, the normal combustion state indicated by the reference numerals (5) and (10) in FIG. 7 and the combustion state due to the heat exchanger blockage (insufficient air amount) indicated by the reference numerals (6) and (7). And the abnormality of the combustion state due to the oxygen deficiency indicated by symbols (8) and (9) are discriminated by the controller 28 (hereinafter referred to as normal, blockage, and oxygen deficiency). On the other hand, depending on the fan drive current detection value, the controller 28 determines whether the normal state indicated by reference numerals (11), (13) and (14) and the blockage indicated by reference numerals (12), (15) and (16) in FIG. To be determined.

If both the FR current detection value and the fan driving current detection value are normal (reference numerals (5) and (11)), abnormal combustion occurs as indicated by reference numeral (17) in FIG. Since there is no cause, the controller 28 makes an integrated determination of normal combustion and does not take any action to deal with abnormal combustion. If both the FR current detection value and the fan drive current detection value indicate blockage (reference numerals (6) and (12)), the cause of abnormal combustion is blockage, so the controller 28 determines that abnormal combustion due to blockage. By increasing the rotation speed of the fan 29 via the fan drive unit 30, a measure such as an increase in air flow is taken (see the column indicated by reference numeral (18) in FIG. 7).
If the FR current detection value indicates blockage (reference numeral (7)) and the fan drive current detection value indicates normal (reference numeral (13)), the controller 28 determines that the disturbance is caused by dust or the like. No action is taken to deal with (see the column indicated by reference numeral (19) in FIG. 7).

Next, the FR current detection value is oxygen deficient (reference numeral (8)), and the fan drive current detection value is normal (reference numeral (1)).
4)) respectively, the controller 28 determines that the combustion is abnormal due to oxygen deficiency and immediately stops the combustion (see the column indicated by reference numeral (20) in FIG. 7). When the FR current detection value indicates oxygen deficiency (reference numeral (9)) and the fan drive current detection value indicates occlusion (reference numeral (15)), the controller 28 is activated.
Is determined to be caused by a disturbance such as wind, and no measures are taken to cope with this (see the column indicated by reference numeral (21) in FIG. 7). When the FR current detection value indicates normal (reference numeral (10)) and the fan driving current detection value indicates closure (reference numeral (16)), the controller 28 closes as indicated by reference numeral (18). It is determined that the abnormal combustion has occurred, and the rotation speed of the fan 29 is increased through the fan drive unit 30 to take measures such as increasing the air volume (see the column indicated by reference numeral (22) in FIG. 7).

FIG. 8 is a flow chart showing the outline of the second example of the processing flow by the controller 28. In FIG. 8, the outline of the integrated determination described above (the determination logic of the combustion state based on the FR current detection value and the fan drive current detection value shown in FIG. 7 and the content of the treatment depending on the determination result) and the thermal efficiency value described above are used. The outline of the process of checking whether the combustion is abnormal or not is described in time series.

Here, in the self-diagnosis function based on the FR current detection value and the fan drive current detection value, C is used as a guide.
The detection target is an O concentration of 2000 ppm or less. On the other hand, in the self-diagnosis function based on the thermal efficiency value, C
The O concentration is set to 20000 ppm or more as a detection target, and it is set to detect a state in which the digit is different from the above two self-diagnosis functions. Of course, the abnormal combustion can be accurately detected only by the integrated judgment based on the FR current detection value and the fan driving current detection value. However, the self-diagnosis function based on the thermal efficiency value is set as a safety measure when the flame rod 24 or the fan drive current detection circuit 31 cannot detect abnormal combustion for some reason. It is possible to prevent the occurrence of problems such as damage to the heat exchanger due to excessive progress of the heat exchanger.

Below, the processing contents described in FIG.
This will be described in detail.

In the above integration judgment, first, FR
After making a temporary determination as to whether or not abnormal combustion has occurred based on the detected current value and the detected fan drive current value, this determination is made as necessary. That is, when the current detection circuit 31 detects a so-called air amount shortage (a decrease in the air supply amount to the burner 21) during the combustion operation (step S21), it is determined to be a block. on the other hand,
The frame rod 24 detects abnormal combustion due to oxygen deficiency or abnormal combustion due to blockage (step S22). Here, when both the current detection circuit 31 and the frame rod 24 detect blockage, a main determination is made as to whether abnormal combustion has occurred.

This main determination is performed during post-purge after the combustion operation is completed (post-purge check mode). In this main determination, the supply / exhaust blockage degree is determined to calculate the amount of decrease in the air amount (step S23). ). Next, after taking measures to increase and correct the fan rotation speed, step S2
1, the process proceeds to S22 (step S24). In addition, the loop of the processing procedure of shifting from steps S21 and S22 to steps S21 and S22 through steps S23 and S24 is continued until the fan rotation speed reaches a predetermined correction upper limit value.

Here, if the relationship of CO / CO2> 0.02 is established between the CO concentration and the CO2 concentration due to the progress of the blockage, it is judged that the improvement of the combustion state due to the increase of the fan rotation speed has reached the limit. . Then, the number of hot water supply outputs is limited to 10 (combustion number), and a warning display indicating that the heat exchanger is blocked is displayed (step S25). Further, if the blockage progresses from this state and CO / CO2> 0.02, or when the cumulative combustion time reaches 30 hours from the time when the number of hot water supply units is limited to 10, the water heater is locked out. Then, it is displayed that the combustion is abnormal due to the heat exchanger blockage (step S26). When the frame rod 24 detects oxygen deficiency (step S22), the fact that the combustion is abnormal due to oxygen deficiency is displayed, and the water heater is immediately stopped (step S2).
7).

On the other hand, the self-diagnosis based on the thermal efficiency value is also executed independently of the integrated judgment described above. First, the state of the heat exchanger is checked based on the detection signals from various sensors during the combustion operation (step S31). As a result, when oxygen deficiency is detected, the process proceeds to step S27 described above,
When the heat exchanger blockage is detected, a warning that the heat exchanger is blocked is displayed as in step S25, and the hot water supply output is limited to No. 10 (step S32). Then, when the state of the heat exchanger blockage further progresses, the water heater is locked out in the same manner as in step S26, and an indication that abnormal combustion due to blockage of the heat exchanger is displayed (step S33).

FIG. 9 is a flowchart showing details of the second example of the processing flow by the controller 28. However, in Figure 9, thermal efficiency value (actual combustion number / output combustion number)
Illustration of the processing for checking whether the combustion is abnormal combustion is omitted.

As is clear from the above description, in the integrated judgment, the processing based on the fan drive current detection value and the F
Although it is performed in parallel with the processing based on the R current detection value,
The process based on the fan drive current detection value will be described first.

First, a temporary determination is made as to whether the combustion is abnormal or not based on the fan drive current detection value. That is, the determination as to whether the heat exchanger is blocked is performed three times in one combustion operation (steps S41 and S42), and the final provisional determination is made as to whether the heat exchanger is blocked after six consecutive combustion operations. (Step S
43).

Next, at the time of post-purging after the end of the combustion operation, the mode shifts to a mode for checking the fan drive current detection value, and the main determination as to whether or not the blockage is made (step S).
49). In this main determination, when it is determined that the combustion is abnormal due to the heat exchanger blockage, it is checked whether the number of hot water supply outputs is limited to 10 (combustion number) (step S50). If it is not limited, it is checked whether or not the correction for increasing the fan rotation speed has been performed up to the fan rotation speed upper limit value (step S51). If there is room for correction by increasing the fan rotation speed, the correction is performed. The fan rotation speed is corrected with the minimum value of three data (step S5).
8, S59).

In step S51, when the correction to increase the fan speed has been performed up to the upper limit value, a warning determination that the blockage of the heat exchanger is progressing is made (step S52). In this warning determination, a final final determination G is performed after 10 consecutive combustion operations (step S
53). Then, the number of hot water supply outputs is limited to 10, and an error display indicating that the improvement of the combustion state due to the increase of the fan rotation speed due to the heat exchanger blockage is limited (step S54).

In step S50, if the number of hot water supply outputs is limited to 10, then the cumulative combustion time is 30
It is checked whether or not time has elapsed (step S5)
5). If 30 hours have not elapsed as a result of this check, it is determined whether abnormal combustion has occurred (step S56). 30
If it is determined that the combustion is abnormal even if the time has elapsed, or if the time has not elapsed, it is determined that the combustion is abnormal due to the heat exchanger blockage, the water heater is locked out, and step S54 is performed.
An error display indicating that the occlusion is progressing further than that in step S57 is displayed (step S57).

In parallel with the above-mentioned provisional determination as to whether abnormal combustion is based on the fan drive current detection value and this determination, provisional determination as to whether abnormal combustion is based on the FR current detection value and this determination are also performed.

That is, first, it is determined whether or not there is an oxygen deficiency (step S44), and when it is determined that the oxygen is deficient, this determination is performed 6 times in one combustion operation (step S6).
0). As a result, when it is finally determined that there is an oxygen deficiency, the water heater is locked out and the fact that abnormal combustion due to oxygen deficiency is present is displayed (step S61).

If it is determined in step S44 that the oxygen deficiency is not present, then a temporary determination is made as to whether or not the heat exchanger is blocked. That is, the determination as to whether or not the heat exchanger is blocked is performed three times in one combustion operation (step S4
(5, S46), a final provisional determination is made as to whether or not there is a blockage after six consecutive combustion operations (step S47). here,
Although it is tentatively determined that the heat exchanger is blocked based on the FR current detection value, if it is determined not to be blocked in the main determination based on the fan drive current detection value, the next tentative determination is followed by the main determination (steps S49 to S59). The number of transitions will be limited to one out of ten provisional determinations (step S48).
This is because, even though it is determined that the fan drive current detection value does not indicate the blockage, the cause that is tentatively determined to be the blockage based on the FR current detection value is, for example, symbols (7) and (1 in FIG.
This is because it is considered to be caused by a disturbance such as dust as shown in 3) and (19).

As described above, according to another embodiment of the present invention, the controller 28 determines whether the combustion state is normal / abnormal, or causes abnormal combustion based on the FR current detection value and the fan drive current detection value. Since the integrated determination is made and the action to be taken when it is determined that the combustion is abnormal, more accurate combustion control can be performed.

Independently of the above integrated judgment, the thermal efficiency value is also checked to see if abnormal combustion has occurred. If it is judged that abnormal combustion has occurred, the water heater is locked out regardless of the result of the integrated judgment. Since I decided to put it in a state,
The safety of the combustion device can be further improved.
Therefore, even if the flame rod 24, the fan drive current detection circuit 31, or the like fails, abnormal combustion can be detected, and an unexpected accident can be prevented.

The above contents are only related to the embodiments of the present invention, and it is needless to say that the present invention is not limited to the above contents.

[0063]

As described above, according to the present invention,
(EN) A combustion device that detects whether the combustion state of a burner is normal or abnormal, and can provide a combustion device that can accurately grasp the cause of abnormal combustion and can take appropriate measures corresponding to the cause of abnormal combustion. it can.

[Brief description of drawings]

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

FIG. 2 is a block diagram when an FR current detector and a fan drive current detection circuit are employed in the apparatus of FIG. 1;

FIG. 3 is a diagram showing an FR current-CO concentration characteristic of a frame rod.

FIG. 4 is a diagram showing a fan drive current-air amount characteristic of the fan drive current detection circuit.

FIG. 5 is a first process flow of a controller (abnormality determination unit)
The flowchart which shows the example of.

FIG. 6 is an explanatory diagram of decision logic obtained as a result of the processing flow of FIG. 5;

FIG. 7 is an explanatory diagram showing a determination logic of a combustion state based on an FR current detection value and a fan drive current detection value according to another embodiment and a treatment content according to the determination result.

FIG. 8 is a flowchart showing an outline of a second example of a processing flow by the controller.

FIG. 9 is a flowchart showing details of a second example of the processing flow by the controller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Combustion state monitoring part 12 Air volume monitoring part 13 Abnormality judgment part 14 Notification part 15 Combustion stopping part 16 Gas amount restriction part 17 Air volume increasing part 21 Burner 23 Insulation member 24 Frame rod 25 FR current detector 26 AC power supply 27 Amplifier 28 Controller 29 Fan 30 Fan drive unit 31 Fan drive current detection circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Somura 43-1, Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo Nihon Yupro Co., Ltd. (72) Inventor Shigeo Yoshida 43-1, Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo No. Nihon Yupro Co., Ltd. (72) Inventor Toru Tsuruta 43-1 Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo Nihon Yupro Co., Ltd.

Claims (12)

[Claims] 1. In a combustion device for supplying fuel and air to a burner to burn the burner, a determining means for determining an abnormality in a combustion state and a cause of the abnormality, and a treatment execution for executing a treatment according to the determined cause of the abnormality. A combustion device comprising: 2. The combustion apparatus according to claim 1, wherein the abnormal causes are an insufficient amount of air supplied to the burner and an oxygen deficiency of air supplied to the burner. 3. The combustion device according to claim 1, wherein the determination means determines the cause of the abnormality from a plurality of state detection values. 4. The combustion apparatus according to claim 3, wherein the plurality of state detection values include a detection value from a combustion state detection unit that detects a combustion state of the burner, and an amount of air supplied to the burner. And a detected value from the air amount detecting means for performing combustion. 5. The combustion device according to claim 4, wherein the combustion state detecting means is a frame rod, and the air amount detecting means is a fan drive current detecting circuit. 6. The combustion apparatus according to claim 5, wherein the determination means determines that the abnormality cause is an air amount shortage when the flame current detection value from the flame rod is larger than a relatively large first threshold value. A combustion device characterized by determining that the cause of abnormality is oxygen deficiency when it is smaller than a second threshold that is smaller than the first threshold. 7. The combustion apparatus according to claim 6, wherein the determination means is based on the flame current detection value and a fan drive current value from the fan drive current detection circuit,
A combustion apparatus, wherein the abnormality and the cause of the abnormality are comprehensively determined. 8. The combustion device according to claim 7, wherein the determination means obtains a thermal efficiency value from the output command combustion amount and the actual combustion amount, and when the determination result is abnormal based on the thermal efficiency value, the determination result is obtained. A combustion device characterized by giving priority to the integrated determination result. 9. The combustion apparatus according to claim 4, wherein the treatment executing means has a control function of controlling the supply amounts of the fuel and the air, and the determining means has the normal air amount, and A combustion apparatus, which notifies the treatment executing means to stop the combustion when the combustion state is detected to be abnormal. 10. The combustion apparatus according to claim 4, wherein the treatment executing means has a control function of controlling the supply amounts of the fuel and the air, and the determining means has an abnormal air amount, and A combustion apparatus characterized in that when the combustion state is abnormal, the treatment execution means is notified so as to control the supply amount of the fuel or air in a direction in which the combustion state returns to a normal state. 11. The combustion apparatus according to claim 4 or 10, wherein the control for returning the combustion state to a normal state increases the air amount when the degree of abnormality is small, and the combustion when the degree of abnormality is large. A combustion device characterized by reducing the amount. 12. The combustion device according to claim 4, further comprising an informing unit that informs an external result of the determination made by the determining unit.