JP3318077B2 - Incomplete combustion detector for combustion equipment - Google Patents

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 a combustion gas of a burner, and an incomplete combustion judgment for judging an incomplete combustion state based on the concentration detected by the sensor. Means for detecting incomplete combustion of a combustion appliance provided with the means.

[0002]

2. Description of the Related Art In such an incomplete combustion detecting device, conventionally, as shown in, for example, Japanese Patent Application Laid-Open No. 5-26438,
When the detected density value of the sensor is equal to or higher than a set density value, a 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 judge that the combustion was incomplete 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 required to determine the incomplete combustion state (hereinafter simply referred to as incomplete combustion determination time). That is, the lower the concentration of the unburned component, the longer the incomplete combustion determination time.

[0003] As described above, the incomplete combustion determination time is changed in accordance with the concentration of unburned components contained in the combustion gas of the burner for the following two reasons. The first reason is that if the detected concentration value of the sensor is equal to or higher than the set concentration value, it is determined that incomplete combustion has occurred. This is because, due to the generation of a fuel component, the incomplete combustion is determined even though the actual total amount of the unburned component is small. The second reason is that in order to solve the problem described in the first reason, if the detected concentration value of the sensor continues to be equal to or higher than the set concentration value for a predetermined time, it is determined that incomplete combustion is performed. In this case, even if a large amount of unburned components is generated, incomplete combustion cannot be determined unless a predetermined time has elapsed, so that a large amount of unburned components is allowed to be generated during that time.

[0004]

However, in the above-mentioned conventional configuration, even in a state in which a large amount of unburned components are generated, which is not preferable in terms of safety, the deviation between the detected density value of the sensor and the set density value is not considered. 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 improved. That is, in the above conventional configuration, the incomplete combustion determination time changes in inverse proportion to the deviation (for example, when the deviation is doubled, the incomplete combustion determination time becomes １ ／). In order to sufficiently secure the original safety, it is necessary to determine the incomplete combustion in a shorter time than the above-mentioned conventional incomplete combustion determination time as the ratio is higher, that is, the larger the deviation is, the more it is necessary. .

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 determining incomplete combustion of a combustion device and sufficiently improving safety. To provide.

[0006]

According to the present invention, there is provided an apparatus for detecting incomplete combustion, comprising: a sensor for detecting the concentration of unburned components contained in the combustion gas of a burner; and an incomplete combustion based on the concentration detected by the sensor. An incomplete combustion determining means for determining a state, wherein the characteristic configuration is such that when the detected concentration value of the sensor is equal to or more than a set concentration value, the incomplete combustion determining means In each case , according to the detected density value of the sensor, the larger the detected density value is, the larger the weighted value is obtained, and the weighted value is integrated, and the integrated value is set at a preset value. With the above, it is determined that the combustion is incomplete , and the detection of the sensor is performed.
When the output density value is less than the set density value for the set time
Then, the integrated value is configured to be initialized .

[0007]

According to the characteristic configuration of the present invention, when the detected density value of the sensor is equal to or more than the set density value , the larger the detected density value is, the larger the detected density value is, per unit time , according to the detected density value of the sensor. A weighted value is obtained by weighting, the weighted value is integrated, and based on whether the integrated value is equal to or larger than a preset value, incomplete combustion is determined , and detection of the sensor is performed. The density value is the set density value
If the value less than continues for the set time, the integrated value is initialized.
Be transformed into Therefore, by performing weighting as described above, in a state where a large amount of unburned components are generated, incomplete combustion can be determined more quickly than in the conventional configuration, and a small amount of unburned components can be determined. In a state where components are generated, the determination of incomplete combustion can be sufficiently delayed as compared with the conventional configuration, and the integrated value is initialized as described above.
By doing so, it is possible to prevent unnecessary determination of incomplete combustion.
Can be controlled. Unnecessarily determining incomplete combustion
The points that can be suppressed are explained below.
You. For example, the combustion becomes temporarily unstable and a small amount of unburned
A state in which the components are generated but combustion resumes immediately
(Hereinafter sometimes referred to as a temporary combustion unstable state)
Even if it occurs, it is said that combustion became temporarily unstable
Since the integrated value calculated at the time of initialization is initialized,
When temporary combustion instability repeats at intervals
When it should not be determined that the combustion is incomplete, as in the case of
Can suppress the determination of incomplete combustion.
To prevent unnecessary discrimination of incomplete combustion.
it can.

[0008]

According to the features of the present invention, 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 generated. In such a state, the determination of incomplete combustion can be sufficiently delayed , and should not be determined as incomplete combustion.
To prevent unnecessary determination of incomplete combustion
Therefore, it is possible to provide an incomplete combustion detection device that can accurately determine incomplete combustion of a combustion device and sufficiently improve safety.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a combustion device (water heater) equipped with the incomplete combustion detection device of the present invention includes a water heater A, a control unit H for controlling the operation of the water heater A, and a remote controller R. Have been. 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 a ventilation means for ventilating combustion air to the burner 2, and an exhaust passage connected to an upper part of the combustion chamber 1. 5, a water supply path 6 for supplying water for heating to the heat exchanger 3,
Hot water heated in the heat exchanger 3 is supplied with hot water (not shown)
(Gas) to the hot water supply path 7 for supplying air to the burner 2
And a fuel supply path 8 for supplying the fuel.

In the water supply passage 6, a water supply amount Qi to the heat exchanger 3 is provided.
Is provided. Hot water supply path 7
Is provided with a hot water temperature sensor 10 for detecting a hot water temperature Tx for a hot water tap. The fuel supply passage 8 is connected to a general household gas supply pipe. In the fuel supply path 8,
Electromagnetic proportional valve 11 for adjusting fuel supply amount Ip to burner 2
And an interrupting valve 12 for interrupting the supply of fuel.

The remote control device R is connected to the control unit H by wire or wirelessly. The remote control device R has an operation switch 13 for instructing start of 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. Note that the LED lamp 15 is configured to display whether or not the water heater is operating, and the LED lamp 16 is configured to display whether or not the incomplete combustion state has occurred.

The exhaust pipe 5 has a sensor for detecting the concentration value CO of the unburned component contained in the combustion gas of the burner 2 as follows.
A CO sensor S is provided. FIG. 2 shows the configuration of the CO sensor S. The CO sensor S is 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 compensation reference element 24
Are each composed of a platinum wire with a tangled catalyst, and are heated to about 200 ° C. by the flow of an electric current, and the unburned components in the combustion gas coming into contact with the surface are burned by the catalytic action. At this time, since the catalyst tangled to 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 increases, the difference between the resistance values of the sensor element 23 and the temperature compensation reference element 24 increases. Therefore, the configuration is such that the CO concentration in the combustion gas can be detected as a difference between the resistance values (sensor output V). In the figure, reference numeral 25 denotes a connector part for connecting to a lead wire connected to the control part H. FIG. 3 shows C in the combustion gas.
The output V of the CO sensor S with respect to the O concentration is shown.

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

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

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 determining means 102 determines whether the CO sensor S According to the detected concentration value CO,
The larger the detected density value CO is, the larger the weighting coefficient N, which is obtained by multiplying the detected density value CO by a weighting coefficient N (F = N × CO), and the weighted value F is integrated. When the integrated value M becomes equal to or _larger than a preset set value M _CHK , it is determined that the combustion is incomplete. In this embodiment, the incomplete combustion determination means 102
Is used to control the combustion control means 101 to stop the combustion of the burner 2 as the incomplete combustion state is determined, and to notify the occurrence of the incomplete combustion state by blinking the LED lamp 16 (abnormal display). ).

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

FIG. 4 shows a change in the output V of the CO sensor S when the combustion of the burner 2 is generally started. In the figure, the combustion start time of the burner 2 is shown at time t1. The sensor output V is initially
In the state where combustion is stopped (before time t1), the output value V1 unique 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 in the exhaust gas (C
O) temporarily becomes very high, so that the output value V once becomes very high. When the combustion of the burner 2 becomes stable, the concentration (CO) of the unburned component decreases, so that the output value V decreases and the output value V2 indicating a steady combustion state.
Converges to

Therefore, the incomplete combustion determining means 102 does not determine that the transient incomplete combustion state immediately after the start of combustion is abnormal, so that the set time T (for example, 6) after the combustion of the burner 2 is started.
(0 seconds).
That is, the incomplete combustion determining means 102 is connected to the timed restraining means 103 for restraining the operation of the incomplete combustion determining means 102 for the set time T after the burner 2 starts burning.

Hereinafter, the control operation of the hot water supply apparatus of the present embodiment will be described with reference to the flowchart shown in FIG.
The hot water supply device stands by in a non-combustion state such as a pilot flame state after the operation start processing and the like are performed. First, as shown in Step 1, the opening of the hot water 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
By 01, the combustion of the burner 2 is started.

Further, as shown in step 6, the combustion control (proportion control based on the fuel supply amount Ip, the water supply amount Qi, and the target tapping temperature Ts) during the timed restraint by the timed restraint means 103 is performed. When the timed restraint ends (step 7), combustion control (proportional control based on the fuel supply amount Ip, the water supply amount Qi, and the target tapping temperature Ts) based on the incomplete combustion determination means 102 is performed (step 8). Therefore, during the operation of the timed restraint means 103, the incomplete combustion determination means 102 is not operated.

When the combustion control after the time limit check shown in step 8 is completed, the operation shifts to a control operation for stopping the combustion. In the control operation for stopping the combustion, the burner 2
Is stopped (step 9), after-purging (step 10) is performed, and the sensor power supply 25 is turned off (step 11) to stand by in a non-combustion state such as a pilot flame state in preparation for the next combustion start. I do.

Next, the combustion control after the timed restraint will be described with reference to the flowchart 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 in step 1
At 5, the detected density value CO at that time is set to the set density value CO.
It is determined whether or not it is _{equal to} or greater than _CHK . In the present embodiment, the reading of the detected concentration value CO of the CO sensor S is performed every second, and the count-up of the counter A is performed every three minutes.

While the counter A counts up (step 16), that is, for three minutes after the counter A starts counting, the detected density value CO of the CO sensor S is read. Concentration value CO
If it is less than _CHK , determine that the combustion state is appropriate,
Initialize the integrated value M (M = 0) (Step 1)
7) After the proportional control (step 18), the process returns to step 13.

When the detected density value CO becomes equal to or greater than the set density value CO _CHK (step 15), the weighting coefficient N shown in FIG. 5 is multiplied by the detected density value CO to obtain a weight value F (step 19). The added value F is integrated to obtain an integrated value M (step 20). After proportional control (step 21), the process returns to step 13. The above steps 13 to 21 are repeatedly executed, and when the integrated value M becomes equal to or larger than the set value M _CHK (step 22), an abnormality display (the 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 steps 13 to 21 are repeatedly executed, the control shifts to the control operation for stopping the combustion.

FIG. 6 shows the case where combustion is continued at a constant CO concentration (constant detected CO value) 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).

[Another Embodiment] The weighting value F in the above embodiment is the same as the detected density value CO shown in FIG.
(F = N × C)
O), the method of obtaining the weighting value F is as described in the above embodiment.
In addition to the method, various other methods can be adopted.
For example, the weighting coefficient N may be set to a constant of 1 or more, or a constant weighted larger as the detected density value CO increases, corresponding to the detected density value CO. , May be used as the weighting value F, or a value obtained by squaring the detected density value CO may be used as the weighting value F.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing the overall configuration of a combustion device.

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

FIG. 3 is a graph showing a change in an output value of a sensor with respect to a 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 a change in combustion stop time.

FIG. 7 is a flowchart of a control operation.

FIG. 8 is a flowchart of a control operation.

[Explanation of symbols]

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

──────────────────────────────────────────────────続 き Continuing from the front page (72) Yoshikatsu Ishikawa 1-152 Oka, Minami-ku, Osaka-shi, Osaka Prefecture Inside Herman Co., Ltd. (72) Kazuyuki Morimoto 1-1-1, Oka, Minami-shi, Minato-ku, Osaka, Osaka No. 52 Harman, Inc. (72) Inventor Hiroshi Kamiya 1-152 Oka, Minami-shi, Minato-ku, Osaka-shi, Osaka Examiner Masayuki Hasui, Harman Inc. (56) Reference Reference (58) Field surveyed (Int. Cl. ⁷ , DB name) F23N 5/24 107 F23N 5/02 350

Claims (1)

(57) [Claims] A sensor (S) for detecting the concentration of unburned components contained in the combustion gas of the burner (2) and an incomplete combustion state based on the detected concentration value of the sensor (S). An incomplete combustion detection device for a combustion device provided with complete combustion determination means (102), wherein the incomplete combustion determination means (102) detects a concentration detected by the sensor (S) as a set concentration value ( C
_O.sub.CHK ) or more, a weighting value (F) is calculated for each unit time, in accordance with the detected density value of the sensor (S), the larger the detected density value is, the greater the weighted value (F) is obtained. Value (F), and the integrated value (M)
Is determined to be incomplete combustion when the _pressure exceeds a preset value (M _CHK ) , and the detection concentration of the sensor (S) is determined.
When the degree value is below the set concentration value (CO _CHK )
If you continue for a while, the integrated value (M) will be initialized
An incomplete combustion detection device for the configured combustion equipment.