JPH07133929A - Incomplete combustion detector for combustion apparatus - Google Patents

Abstract

PURPOSE:To enhance reliability in sensing incomplete combustion by obtaining a weighting value in which larger weighting value is set as a deviation or a detected concentration value is larger at each unit time when the detected concentration of a sensor is a set concentration value or more, and deciding the incomplete combustion when an integrated value of the value is a set value or more. CONSTITUTION:A combustion apparatus has a controller H for deciding an incomplete combustion state based on a detected concentration value of a sensor S for detecting a concentration of an unburnt component contained in combustion gas of a burner 2, and comprises incomplete combustion sensing means 102 provided in the controller H to obtain a weighted value F in which large weighting value is set as a deviation between the detected concentration value of the sensor S and a set concentration value or the detected concentration value of the sensor S is larger at each unit time when the detected concentration of the sensor S is a set concentration value or more. The weighted value F is integrated, and when the integrated value becomes a preset value or more, the incomplete combustion is decided, combustion of the burner 2 is stopped, and an LED lamp 16 is flashed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor for detecting the concentration of unburned components contained in the combustion gas of a burner, and an incomplete combustion determination for determining an incomplete combustion state based on the detected concentration value of the sensor. And an incomplete combustion detection device for a combustion device provided with the means.

[0002]

2. Description of the Related Art In such an incomplete combustion detecting device, conventionally, as disclosed in, for example, Japanese Unexamined Patent Publication No. 5-26438,
When the detected density value of the sensor is equal to or higher than the set density value, the deviation between the detected density value of the sensor and the set density value is obtained for each unit time, the deviation is integrated, and the integrated value is set in advance. It was configured to determine incomplete combustion as the set value was exceeded. With this configuration, the higher the concentration of the unburned components contained in the combustion gas of the burner, the shorter the time until it is determined that the incomplete combustion state is (hereinafter, simply referred to as the incomplete combustion determination time). Therefore, the lower the concentration of unburned components, the longer the incomplete combustion determination time.

Incidentally, as described above, the incomplete combustion determination time is changed according to the concentration of the unburned component contained in the combustion gas of the burner for the following two reasons. The first reason is that if it is determined that the incomplete combustion occurs when the detected concentration value of the sensor is equal to or higher than the set concentration value, the incomplete combustion is determined only by the detected concentration value of the sensor. This is because, due to the generation of fuel components and the like, incomplete combustion is determined even though the actual total amount of unburned components is small. The second reason is that in order to solve the problem described in the first reason, it is determined that the incomplete combustion occurs when the detected concentration value of the sensor continues to be a value equal to or higher than the set concentration value for a predetermined time. Then, even if a large amount of unburned component is generated, incomplete combustion cannot be discriminated until a predetermined time has elapsed, and therefore, generation of a large amount of unburned component is allowed during that period.

[0004]

However, in the above-mentioned conventional configuration, even in a situation in which a large amount of unburned component is generated, which is unfavorable for safety, the deviation between the detected concentration value of the sensor and the set concentration value is Until the integrated value reaches the set value, it cannot be determined that the combustion is incomplete, so that combustion cannot be stopped during that time, and as a result, there is a problem that safety cannot be sufficiently enhanced. That is, in the above-described conventional configuration, the incomplete combustion determination time changes in inverse proportion to the deviation (for example, if the deviation doubles, the incomplete combustion determination time becomes ½). In order to sufficiently secure the original safety, it is necessary to determine the incomplete combustion in a higher ratio, that is, in a shorter time than the conventional incomplete combustion determination time as the deviation increases. .

The present invention has been made in view of the above circumstances, and an object thereof is to provide an incomplete combustion detection device capable of accurately discriminating incomplete combustion of a combustion device and sufficiently improving safety. To provide.

[0006]

The incomplete combustion detection system of the present invention is a sensor for detecting the concentration of unburned components contained in the combustion gas of a burner, and an incomplete combustion based on the detected concentration value of the sensor. An incomplete combustion determination means for determining the state is provided, and the characteristic configuration is that the incomplete combustion determination means, when the detected concentration value of the sensor is equal to or higher than a set concentration value, a unit time For each, the deviation between the detected density value of the sensor and the set density value or the detected density value of the sensor, depending on the deviation or the detected density value, to obtain a weighted value with a greater weight, the greater The point is that the weighting values are integrated, and when the integrated value becomes equal to or larger than a preset value, it is determined that the combustion is incomplete.

[0007]

According to the characteristic configuration of the present invention, when the detected concentration value of the sensor is equal to or higher than the set concentration value, the deviation or the detected concentration value is detected according to the deviation or the detected concentration value of the sensor for each unit time. Is larger, a weighted value with greater weighting is obtained, the weighted values are integrated, and incomplete combustion is determined by whether or not the integrated value is equal to or greater than a preset set value. Therefore, by weighting as described above, in a state where a large amount of unburned components are generated, incomplete combustion can be determined more quickly and a small amount of unburned components can be detected as compared with the conventional configuration. In the state where components are generated, the determination of incomplete combustion can be sufficiently delayed compared to the conventional configuration.

[0008]

According to the characterizing feature of the present invention, in a state where a large amount of unburned components are generated, incomplete combustion can be more quickly discriminated and a small amount of unburned components is generated. In such a state, it is possible to sufficiently delay the determination of incomplete combustion, so it is possible to provide an incomplete combustion detection device capable of accurately determining incomplete combustion of a combustion device and sufficiently improving safety. I was able to do it.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a combustion device (hot water supply device) including the incomplete combustion detection device of the present invention includes a water heater A, a controller H that controls the operation of the water heater A, and a remote controller R. Has been done. The water heater A includes a combustion chamber 1 and a combustion chamber 1
2, a heat exchanger 3 for heating water, a fan 4 as ventilation means for passing combustion air to the burner 2, and an exhaust passage connected to the upper part of the combustion chamber 1. 5, and a water supply channel 6 for supplying water for heating to the heat exchanger 3,
A hot water tap (not shown) for hot water heated in the heat exchanger 3
To the hot water supply passage 7 and the burner 2 for supplying fuel (gas)
And a fuel supply path 8 for supplying

In the water supply passage 6, the amount of water supplied to the heat exchanger 3 Qi
A water supply amount sensor 9 for detecting is provided. Hot water supply passage 7
Is equipped with a hot water supply temperature sensor 10 for detecting the hot water supply temperature Tx for the hot water supply tap. The fuel supply path 8 is connected to a gas supply pipe for general households. In the fuel supply passage 8,
Electromagnetic proportional valve 11 for adjusting the fuel supply amount Ip to the burner 2
And an on-off valve 12 that connects and disconnects the fuel supply.

The remote controller R is connected to the control unit H by wire or wirelessly, and has an operation switch 13 for instructing to start the operation of the hot water supply device, a temperature setting switch 14 for setting a set target hot water supply temperature Ts, and various information. LED to display
Lamps 15 and 16 are provided. The LED lamp 15 is configured to display whether the hot water supply device is operating, and the LED lamp 16 is configured to display whether an incomplete combustion state has occurred.

The exhaust stack 5 serves as a sensor for detecting the concentration value CO of the unburned component contained in the combustion gas of the burner 2.
A CO sensor S is provided. FIG. 2 shows the configuration of this CO sensor S. The CO sensor S includes a sensor element 2 mounted on a pedestal 22 inside a protective frame 21 made of stainless steel.
3 and a reference element 24 for temperature compensation.
The sensor element 23 and the temperature compensating reference element 24
Are composed of platinum wires, each of which has a catalyst, and are heated to about 200 ° C. by the flow of an electric current, and the unburned components in the combustion gas that come into contact with the surface thereof burn by catalytic action. At this time, since the catalyst tangled in the sensor element 23 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 difference between the resistance values of the sensor element 23 and the temperature compensating reference element 24 becomes large. Therefore, the CO concentration in the combustion gas can be detected as a difference in resistance value (sensor output V). Incidentally, reference numeral 25 in the figure denotes a connector portion with a lead wire connected to the control portion H. Fig. 3 shows C in combustion gas
The output V of the CO sensor S with respect to the O concentration is shown.

The control section H includes combustion control means 101 for controlling the combustion operation of the water heater A and incomplete combustion determination means 102 for determining an incomplete combustion state based on the detected concentration value CO of the CO sensor S. It is provided.

The combustion control means 101 includes a water supply amount sensor 9
, Hot water supply temperature sensor 10, solenoid proportional valve 11, and intermittent valve 1
2, the fan 4, and the remote control device R are connected, and the combustion control means 101 sets the hot water supply temperature Tx to the set target hot water supply temperature based on the water supply amount Qi adjusted by the hot water tap and the set target hot water supply temperature Ts. The proportional solenoid valve 11 is adjusted to the temperature Ts to adjust the fuel supply amount Ip of the burner 2 and the rotation speed of the fan 4 is set to the rotation speed preset based on the fuel supply amount Ip. , Operate the fan 4.

When the detected concentration value CO of the CO sensor S is equal to or higher than the set concentration value CO _CHK (specifically, CO _CHK = 800 ppm), the incomplete combustion discriminating means 102 outputs the CO sensor S of the CO sensor S every unit time. Depending on the detected concentration value CO,
The larger the detected concentration value CO is, the greater the weighting coefficient N weighted is to obtain the weighted value F obtained by multiplying the detected concentration value CO (F = N × CO), and the weighted value F is added up. The incomplete combustion is determined as the integrated value M becomes equal to or _larger than a preset set value M _CHK . In the present embodiment, the incomplete combustion determination means 102
Is a notification of the occurrence of an incomplete combustion state by controlling the combustion control means 101 to stop the combustion of the burner 2 and blinking the LED lamp 16 as the incomplete combustion state is determined (abnormality display). ) Is configured to do.

As shown in FIG. 5, the weighting coefficient N is set in advance in correspondence with the detected concentration value CO such that the larger the detected concentration value CO, the larger the value.

Incidentally, FIG. 4 generally shows the change in the output V of the CO sensor S when the combustion of the burner 2 is started. In the figure, the combustion start time of the burner 2 is indicated by time t1. The sensor output V is initially
In the state where the combustion is stopped (before the time t1), the output value V1 peculiar to the sensor S is shown. Immediately after the start of combustion (immediately after time t1), a transient incomplete combustion state occurs in the combustion of the burner 2, and the concentration of unburned components (C
O) temporarily becomes very high, so the output value V once becomes very high. Then, when the combustion of the burner 2 becomes stable, the concentration (CO) of the unburned component decreases, so the output value V becomes low and the output value V2 indicating a steady combustion state.
Converge to.

Therefore, the incomplete combustion discriminating means 102 does not discriminate the transient incomplete combustion state immediately after the start of combustion as abnormal, so that the set time T after the start of combustion of the burner 2 (for example, 6).
It is configured to operate after 0 seconds).
In other words, the incomplete combustion determination means 102 is connected to the timed control means 103 that controls the operation of the incomplete combustion determination means 102 for the set time T after the start of combustion of the burner 2.

The control operation of the hot water supply apparatus of this embodiment will be described below with reference to the flow chart shown in FIG.
The hot water supply device stands by in a non-combustion state such as a pilot fire state after the operation start processing and the like are performed. First, as shown in step 1, opening of the hot water supply tap is detected by the water supply amount sensor 9. When the opening of the hot water tap is detected, the sensor power supply 25 is turned on as shown in step 2, and the timed restraint of the incomplete combustion determination means 102 by the timed restraint means 103 is started as shown in step 3. . Then, as shown in step 4, the fan 4 blows air (prepurge).
Is started, and as shown in step 5, the combustion control means 1
The combustion of the burner 2 is started by 01.

Further, as shown in step 6, the combustion control (proportional control based on the fuel supply amount Ip, the water supply amount Qi, the target outlet hot water temperature Ts) is performed during the time control by the time control means 103. When the time limit check is completed (step 7), combustion control based on the incomplete combustion determination means 102 (proportional control based on the fuel supply amount Ip, the water supply amount Qi, and the target outlet temperature Ts) is performed (step 8). Therefore, the incomplete combustion determination means 102 is prevented from operating while the timed restraint means 103 is operating.

When the combustion control after the time-limited check shown in step 8 is completed, the control operation of the combustion stop is started. In the control operation for stopping the combustion, the burner 2 is controlled by the combustion control means 101.
Combustion is stopped (step 9), after-purging (step 10) is performed, and the sensor power supply 25 is turned off (step 11) to wait for the next combustion start in a non-combustion state such as a pilot fire state. To do.

Next, the combustion control after the timed check will be described with reference to the flow chart shown in FIG. First, the integrated value M is initialized (M = 0) (step 12), and the counter A is reset to start counting by the counter A (step 13). In step 14, the detected concentration value CO of the CO sensor S is read, and step 1
5, the detected concentration value CO at that time is the set concentration value CO
It is determined whether _CHK or more. In the present embodiment, the detection density value CO of the CO sensor S is read every 1 second, and the counter A is incremented every 3 minutes.

While the counter A is being counted up (step 16), that is, the detected concentration value CO of the CO sensor S is read for 3 minutes after the counting of the counter A is started, the detected concentration value CO during that period is set. Concentration value CO
If it is less than _CHK , it is judged that the combustion state is appropriate,
Initialize the integrated value M (M = 0) (step 1
7) After proportional control (step 18), the process returns to step 13.

When the detected concentration value CO exceeds the set concentration value CO _CHK (step 15), the weighting coefficient N of FIG. 5 is multiplied by the detected concentration value CO to obtain the weighting value F (step 19). The added value F is integrated to obtain the integrated value M (step 20), after proportional control (step 21), the process returns to step 13. When the integrated value M becomes equal to or greater than the set value M _CHK (step 22) by repeating the above steps 13 to 21, an abnormality display (LED lamp 16 blinks) is performed (step 23), and the above-described combustion stop control operation is performed. Move to. When the hot water tap is closed (steps 24 and 25) while the above steps 13 to 21 are repeatedly executed, the above-described combustion stop control operation is performed.

FIG. 6 shows that when combustion is continued at a constant CO concentration (constant concentration value CO is constant) in the above embodiment,
It specifically shows the relationship between the detected concentration value CO and the combustion stop time (the time from the start of combustion control after the timed restraint to the stop of combustion).

[Other Embodiment] FIG. 9 shows the combustion control after the time restraint in the above embodiment.
The control method may be simplified as shown in the flowchart of FIG. The flowchart of FIG. 9 will be described below. First, in step 31, the integrated value M is initialized (M = 0), and then in step 32, the detected concentration value CO of the CO sensor S is read. The weighting coefficient N in FIG. 5 is set to the detected concentration value CO and the set concentration value CO _CHK.
Weighted value F ′ multiplied by the deviation (CO-CO _CHK ) from
Is calculated (step 33), and the weighted value F ′ is integrated to calculate an integrated value M (step 34). If the integrated value M is less than the set value M _CHK ', after proportional control (step 3
8) Return to step 32 and the integrated value M is the set value M _CHK '
If it is above, the abnormality display (the LED lamp 16 blinks) is performed (step 39), and the control operation of the combustion stop described above is performed. When the hot water tap is closed (step 40) while the above steps 32 to 38 are repeatedly executed, the above-mentioned combustion stop control operation is performed. The weighting value F in the above embodiment is obtained by multiplying the detected concentration value CO by the weighting coefficient N shown in FIG. 5 (F = N
As for the method of obtaining the weighting value F, the other various methods can be adopted in addition to the method described above.
For example, the weighting coefficient N may be set to a constant of 1 or more, or a larger weighted constant is set in correspondence with the detected concentration value CO as the detected concentration value CO is larger. The constant may be used as the weighting value F, or the value obtained by squaring the detected concentration value CO may be used as the weighting value F.

It should be noted that reference numerals are added to the claims for convenience of 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 configuration diagram showing an overall configuration of a combustion device.

FIG. 2 is a schematic diagram showing the overall structure of the sensor.

FIG. 3 is a graph showing changes in sensor output value with respect to CO concentration.

FIG. 4 is a graph showing a time change of an output value of a sensor.

FIG. 5 is a graph showing weighting factors.

FIG. 6 is a graph showing changes in combustion stop time.

FIG. 7 is a flowchart of control operation

FIG. 8 is a flowchart of control operation

FIG. 9 is a flowchart of a control operation according to another embodiment.

[Explanation of symbols]

2 Burner 102 Incomplete combustion determination means CO _CHK set concentration value F Weighting value M Integrated value M _CHK set value S Sensor

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazuyuki Morimoto 1-52, Minami-shi Oka, Minato-ku, Osaka, Osaka 1-52 Harman Co., Ltd. (72) Inventor Hiroshi Kamiya 1-1-52 Minami-shi, Minato-ku, Osaka, Osaka Issue Harman Co., Ltd.

Claims (1)

[Claims] 1. A sensor (S) for detecting the concentration of an unburned component contained in the combustion gas of a burner (2), and an incomplete combustion state determination based on the detected concentration value of the sensor (S). An incomplete combustion detection device for a combustion device provided with a complete combustion determination means (102), wherein the incomplete combustion determination means (102) is configured so that the detected concentration value of the sensor (S) is a set concentration value ( C
O _CHK ) or more, the detected concentration value of the sensor (S) and the set concentration value (CO _CHK ) per unit time
Depending on the deviation from or the concentration value detected by the sensor (S),
The larger the deviation or the detected density value is, the larger the weighted value (F) is obtained, and the weighted value (F) is obtained.
And an incomplete combustion detection device for a combustion device configured to determine incomplete combustion when the integrated value (M) exceeds a preset set value (M _CHK ).