JP2000161667A - Device for detecting incomplete combustion of combustor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly judge incomplete combustion of a combustor. SOLUTION: This device is equipped with a 0-point reference value storage means 32 which stores the output voltage of a CO concentration detection means 20 in a combustion-stop condition as a 0-point reference value for detection of CO concentration, a CO concentration computation means 33 which computes the CO concentration in exhaust, using the 0-point reference value and the output voltage of the CO concentration detection means 20, and an incomplete combustion stop means which stops the combustion operation of a combustor. In this case, the device is provided further with a 0-point reference value update means which performs a 0-point reference value update processing of detecting the output voltage of the CO concentration detection means 20 at specified intervals when the combustor is in a combustion-stop condition, and storing the detected output voltage in the 0-point reference value storage means 32, as a new 0-point reference value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an incomplete combustion detection device for detecting incomplete combustion of a combustion device.

[0002]

2. Description of the Related Art Conventionally, for example, in a gas water heater for supplying hot water by heating water with a gas burner, an incomplete combustion detecting device is provided to prevent incomplete combustion of the gas burner from continuing. The incomplete combustion detection device includes:
It has CO concentration detecting means for outputting a voltage corresponding to the CO concentration in the combustion exhaust gas from the gas burner.
When the CO concentration detected from the output voltage of the CO concentration detecting means becomes equal to or higher than a predetermined reference concentration, it is determined that the gas burner is in an incomplete combustion state, and the combustion operation of the gas burner is stopped. .

Here, the CO concentration detecting means is constituted by using a CO sensor (CO detecting element) whose resistance value changes according to the CO concentration, and a correlation between the CO concentration and the resistance value of the CO sensor is provided. The relationship is the ambient temperature and humidity of the CO sensor,
It fluctuates due to various factors such as impact and aging of the CO sensor itself. Therefore, it is known that the correlation between the CO concentration and the output voltage of the CO concentration detecting means also fluctuates due to these factors.

The variation of the output voltage of the CO concentration detecting means shifts in parallel as a whole as shown in FIG. For this reason, conventionally, the output voltage of the CO concentration detecting means when the gas burner is in the combustion stopped state and the CO concentration can be assumed to be approximately 0 ppm has been determined as the zero point reference value. By correcting the detection value of the output voltage of the CO concentration detecting means based on the zero point reference value determined in this way, even if the output voltage of the CO concentration detecting means fluctuates due to the various factors described above, the CO concentration can be reduced. It was designed to be able to detect with high accuracy.

[0005] However, in the conventional incomplete combustion detection device, when the environment around the CO sensor becomes stable after the combustion operation of the combustion equipment is completed (for example, when 30 minutes have elapsed after the combustion was stopped). In this case, the output voltage of the CO concentration detecting means was set to the zero point reference value. In this case, for example, when the combustion equipment is not used due to the absence of a user, a vibration shock is applied to the CO sensor constituting the CO concentration detecting means or the surface state of the CO sensor changes during that time. And C
The correlation between the output voltage of the O concentration detecting means and the CO concentration may fluctuate.

When the user uses the combustion equipment after the correlation between the output voltage of the CO concentration detecting means and the CO concentration fluctuates, the CO concentration is reduced based on the zero point reference value before the fluctuation. As a result, the incomplete combustion cannot be accurately determined.

There is also an incomplete combustion detection device in which when the start of combustion of the combustion equipment is instructed, the output voltage of the CO concentration detection means immediately before the start of combustion is set to the zero point reference value. In this case, for example, immediately after a burner misfires, when a reignition instruction is given to the burner,
In a state where the CO concentration is high immediately after the misfire (the state where the CO concentration is not 0 ppm), the output voltage of the CO concentration detecting means is determined as the zero point reference value. In this case, the CO concentration is 0
Since the CO concentration is calculated based on an erroneous 0-point reference value in a state other than ppm, there is a disadvantage that it is not possible to accurately determine that incomplete combustion has occurred.

[0008] Immediately after the combustion equipment stops burning,
Since the exhaust gas temperature drops rapidly, the output voltage of the CO concentration detecting means tends to become unstable due to the transient response performance of the CO sensor. Therefore, as described above, when the 0-point reference value is determined immediately after the burner misfires, there is a problem that the accurate 0-point reference value may not be obtained.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an incomplete combustion detection device which can solve the above-mentioned disadvantages and can accurately judge that incomplete combustion has occurred in a combustion apparatus. .

[0010]

In order to achieve the above object, the present invention provides a CO concentration detecting means for outputting a voltage corresponding to the CO concentration in the exhaust gas of a combustion device, and an actual CO concentration of 0 pp.
m, the output voltage of the CO concentration detecting means is represented by CO
A zero point reference value storage means for storing as a zero point reference value for concentration detection, and exhaust is performed using the zero point reference value stored in the zero point reference value storage means and the output voltage of the CO concentration detection means. CO concentration calculating means for calculating a CO concentration in the CO;
When the CO concentration calculated by the concentration calculation means is equal to or higher than a predetermined concentration, the combustion equipment is determined to be in an incomplete combustion state, and incomplete combustion stop means for stopping the combustion operation of the combustion equipment is provided. In the incomplete combustion detection device for the combustion equipment provided, when the combustion equipment is in a combustion stop state,
At predetermined time intervals, the output voltage of the CO concentration detecting means is detected, and the detected output voltage is replaced with the zero point reference value stored in the zero point reference value storage means until then, and the new voltage is detected. A zero-point reference value updating means for storing the zero-point reference value in the zero-point reference value storage means is provided.

[0011] According to the present invention, the zero point reference value updating means sets the CO value at a predetermined time interval when the combustion device is in the combustion stopped state and the CO concentration is assumed to be approximately 0 ppm. An output voltage of the density detecting means is detected, and the output voltage is stored in the zero point reference value storage means as a new zero point reference value. Therefore, when the combustion equipment is not used, the CO concentration and the CO concentration detection means may be changed by various factors such as changes in room temperature and humidity, vibration and shock, and aging of the CO concentration detection means itself. Even if the correlation with the output voltage changes, the zero point reference value stored in the zero point reference value storage means is updated in accordance with the fluctuation.

When the combustion of the combustion equipment is started, the CO concentration calculating means updates a new 0
The CO concentration is calculated based on the point reference value. Therefore, the incomplete combustion stopping means is provided by the various factors described above.
Even if the correlation between the CO concentration and the output voltage of the CO concentration detecting means fluctuates, the influence of the fluctuation can be eliminated and the occurrence of incomplete combustion of the combustion equipment can be accurately determined.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an incomplete combustion detecting apparatus for a combustion apparatus according to the present invention will be described with reference to FIGS. FIG. 1 shows a gas water heater equipped with the incomplete combustion detection device of the present invention (corresponding to a combustion device of the present invention).
FIG. 2 is a control block diagram of the incomplete combustion detection device of the present embodiment, FIG. 3 is an operation flowchart of the incomplete combustion detection device of the present embodiment, and FIG. It is an output characteristic graph of a CO sensor in a combustion detecting device.

Referring to FIG. 1, gas water heater 1 includes a gas burner 3 provided in combustion housing 2 and a combustion fan 4 for supplying combustion air X to gas burner 3. It has a supply port 5 for combustion air X below and an exhaust port 6 for combustion exhaust Z above. Further, a heat exchanger 7 is arranged above the gas burner 3 in the combustion housing 1. The gas burner 3 includes a burner group 8 that forms a flame, and a nozzle pipe 10 that is located below the burner group 8 and that has an ejection port 9. The fuel gas Y is supplied to the gas burner 3 via a gas pipe 11. You.

The gas water heater 1 includes a water governor 12 for keeping the flow rate of water supplied to the heat exchanger 7 constant, a water amount sensor 13 for detecting whether or not water is supplied to the heat exchanger 7, and hot water from the heat exchanger 7. A thermistor 14 for detecting temperature, a source gas solenoid valve 15 and a main solenoid valve 16 for opening and closing a fuel gas supply path to the gas burner 3, a governor-type gas proportional valve 17 for adjusting a supply amount of combustion gas to the gas burner 3, An igniter 18 for igniting the gas burner 3, a flame rod 19 for detecting the presence or absence of combustion of the gas burner 3, and a C for detecting the CO concentration in the combustion exhaust gas
O sensor 20 and controller 2 connected thereto
1 is provided.

The controller 21 includes a CPU, ROM, R
An electronic unit constituted by an AM or the like; a combustion control means 30 for controlling combustion of the gas burner 3;
And incomplete combustion detecting means 31 for forcibly stopping the combustion of the gas burner 3 when the incomplete combustion is detected. The incomplete combustion detection device 31 and the CO sensor 20 constitute an incomplete combustion detection device of the present invention.

The CO sensor 20 is a CO detecting element whose resistance value changes according to the CO concentration.
When a predetermined current is supplied from 1, it operates as a CO concentration detecting means of the present invention that outputs a voltage corresponding to the CO concentration. The controller 21 performs a predetermined correction process on the output voltage of the CO sensor 20 so that the correlation between the output voltage of the CO sensor 20 and the CO concentration becomes the linear equation M shown in FIG.

Referring to FIG. 2, incomplete combustion detecting means 31
The EEPROM 3 stores the output voltage of the CO sensor 20 as the zero point reference value Z ₀ when the gas burner 3 is in the combustion stopped state and the CO concentration can be assumed to be approximately 0 ppm.
2 (corresponding to the zero-point reference value storage means of the present invention) and CO
The data of the relational expression M (see FIG. 4) between the output voltage V _C of the sensor 20 and the actual CO concentration and the initial value Z _{I of the} zero point reference value Z ₀ (set at the time of factory shipment) are held. Sensor 2
And a CO concentration calculating means 33 for calculating the CO concentration C _R in the combustion exhaust gas Z by using the output voltage V _C and 0 point reference value Z _0, which is stored in the EEPROM32 zero.

Further, the incomplete combustion detection means 31, during combustion of the gas burner 3, the CO concentration C _R of the combustion exhaust Z calculated by the CO concentration calculating means 33, a predetermined stored in ROM34 reference concentration C _B (equivalent to a predetermined concentration of the present invention) or more, it is determined that the gas burner 3 is in an incomplete combustion state, and incomplete combustion instructing the combustion control means 30 to stop the combustion of the gas burner 3 Stopping means 35
And a zero-point reference value updating means 36 for updating the zero-point reference value Z ₀ at a predetermined timing (details will be described later) after the combustion of the gas burner 3 is stopped.

Next, the basic operation of the gas water heater 1 of the present embodiment will be described with reference to FIGS.

Referring to FIG. 1, combustion control means 30 provided in controller 21 controls the combustion of gas burner 3 when detecting that a hot water tap (not shown) has been opened based on the detection output of water quantity sensor 13. To start. That is, the combustion control unit 30 starts supplying the combustion air X to the gas burner 3 by operating the combustion fan 4 in a state in which the igniter 18 is energized to generate a spark discharge, and the original gas solenoid valve 15. Then, the main solenoid valve 16 is opened to start supplying the fuel gas Y to the gas burner 3, and the ignition process of the gas burner 3 is performed. Then, when the combustion of the gas burner 3 is detected based on the detection output of the frame rod 19, the combustion control means 30 cuts off the power supply to the igniter 18. Further, the controller 21 simultaneously starts the combustion of the gas burner 3.
, The energization of the CO sensor 20 is started, and the incomplete combustion detection means 31 starts operating.

The combustion control means 30 controls the temperature of the hot water from the heat exchanger 7 detected by the thermistor 14 after the start of combustion of the gas burner 3 so that the temperature matches the predetermined target hot water supply temperature.
The amount of fuel gas Y supplied to the gas burner 3 is controlled by adjusting the opening of the gas proportional valve 17, and the amount of combustion air X supplied to the gas burner 3 is controlled by adjusting the rotation speed of the combustion fan 4. I do.

When the combustion control means 30 detects that the hot water tap has been closed by the detection output of the water quantity sensor 13, the combustion control means 30 closes the original gas solenoid valve 15 and the main solenoid valve 16 to close the gas burner 3. Is stopped, the operation of the combustion fan 4 is stopped, and the combustion control of the gas burner 3 is terminated.

Referring to FIG. 2, incomplete combustion detecting means 31
Is the combustion of the gas burner 3 by the CO concentration calculating means 33.
Output voltage V of CO sensor 20_C, EEPRO
Zero point reference value Z stored in M32₀, Relation M, and 0
Initial point reference value Z_IFrom this, the CO concentration in the combustion exhaust Z
C_RIs calculated. Then, the calculated CO concentration C_RRO
Reference density C stored in M34_BCompare to the value
Concentration C_RIs the reference concentration C _BWhen it becomes more than
The burning stop means 35 is provided when the gas burner 3 is in an incomplete combustion state.
It is determined that the gas burner 3
To stop burning.

When the combustion control means 30 receives the instruction to stop the combustion of the gas burner 3 from the incomplete combustion stop means, the combustion control means 30 closes the original gas solenoid valve 15 and the main solenoid valve 16 to stop the combustion of the gas burner 3 and perform the combustion. The operation of the fan 4 is stopped, and the power supply to the CO sensor 20 is stopped. This enables gas burner 3
This prevents the incomplete combustion of the gas from continuing.

Here, if the correlation between the resistance value of the CO sensor 20 and the actual CO concentration is constant, and the correlation between the output voltage of the CO sensor 20 and the actual CO concentration is kept constant. , The CO concentration calculating means 33 can accurately calculate the CO concentration according to the data of the relational expression M set at the time of shipment from the factory.

However, actually, the correlation between the resistance value of the CO sensor 20 and the actual CO concentration fluctuates due to various factors such as shock vibration, temperature, and humidity. Then, when the variation of the correlation is accumulated, the error between the CO concentration C _R calculated by the CO concentration calculating means 33 and the actual CO concentration from the output voltage V _C of the CO sensor 20 and the relational expression M is calculated. Is expanded, and the gas burner 3
Incomplete combustion cannot be accurately determined.

Therefore, the zero point reference value updating means 36 provided in the incomplete combustion detecting means 31 detects the CO sensor 20 when the gas burner 3 is in the combustion stopped state and the CO concentration is almost 0 ppm. enter the output voltage V _C, the output voltage V _C, it until replaced by a 0-point reference value Z ₀ which has been stored in the zero point reference value storage means 32, stored as a reference value Z ₀ new zero point A zero point reference value updating process is performed.

Referring to FIG. 4, the fluctuation of the correlation between the output voltage V _C of CO sensor 20 and the actual CO concentration shifts in parallel as shown by the relational expressions M to N in the figure. the form (in this case, for example, the actual CO concentration when the output voltage of the CO sensor 20 is Z _E is changed from C _M to C _N). Therefore, if the zero-point reference value Z _N after the correlation is changed can be grasped, the initial value Z ₀ of the zero-point reference value Z ₀ can be obtained.
By correcting the output voltage V _C of the CO sensor 20 based on the difference Δt between _I and Z _N , the actual CO concentration can be accurately determined from the output voltage V _C of the CO sensor 20 even when the correlation varies. Can be calculated.

Therefore, the CO concentration calculating means 33 determines when the relational expression M is set, that is, the zero point reference value Z ₀ at the time of factory shipment.
Holds the initial value Z _I is being updated by the initial value Z _I and 0 point reference value updating means 36, CO concentration C on the basis of the difference Δt between the 0 point reference value Z _0, which is stored in the EEPROM32
_R is calculated. Thus, even if the correlation between the output voltage V _C of the CO sensor 20 and the actual CO concentration fluctuates, the effect of the fluctuation can be eliminated, and the CO concentration C _R can be accurately calculated. As a result, the incomplete combustion stopping means 35 outputs the output voltage of the CO sensor 20 and the actual CO
Even if the correlation with the concentration fluctuates, the CO concentration calculating means 33
The incomplete combustion of the gas burner 3 can be accurately determined based on the CO concentration C _R calculated by the above.

Next, the operation of the incomplete combustion stopping means 35 will be described with reference to FIGS. 1 and 2 and the flow chart shown in FIG. 3, focusing on the operation of the zero point reference value updating means 36.

Referring to FIG. 1, when power is supplied to water heater 1, controller 21 is also energized, and combustion control means 30 and incomplete combustion detection means 31 start operating. Then, the incomplete combustion detecting means 31 performs self-cleaning by applying a high voltage to the CO sensor 20 for a predetermined time (for example, 60 seconds) in STEP 1 of FIG. 3, and a zero-point reference value updating means 36 (see FIG. 2) in STEP 2. Is a 30-minute timer 40
(See FIG. 2).

In the following STEP 3, when it is recognized from the operation state of the combustion control means 30 that the gas burner 3 is in the combustion state, the flow branches to STEP 20. STEP20-S
TEP 22 is processing by the incomplete combustion stopping means 35 (see FIG. 2). The incomplete combustion stopping means 35 is provided in STEP 2
In 0, CO concentration C _R in the combustion exhaust Z calculated by the CO concentration calculation unit 33 (see FIG. 2) confirms whether a stored reference concentration C _B more than the ROM 34. CO
When the concentration C _R was the reference concentration C _B above, incomplete combustion stop means 35 proceeds from STEP20 to determine the gas burner 3 is in the incomplete combustion state in STEP 21, the gas burner against the combustion control means 30 A combustion stop instruction of 3 is performed. In response to the combustion stop instruction, the combustion control means 30 closes the original gas solenoid valve 15 and the main solenoid valve 16 to stop the combustion of the gas burner 3. This prevents the gas burner 3 from continuing incomplete combustion.

On the other hand, in STEP 20, when CO concentration C _R calculated is less than the reference concentration C _B by CO concentration calculating means 33, the process branches to STEP 22. And
When it is recognized from the operation state of the combustion control means that the gas burner 3 is in the combustion state, the process branches to STEP 20, and the incomplete combustion stopping means 35 checks whether or not the gas burner 3 is in the incomplete combustion state. Execute repeatedly. When it is confirmed in STEP 22 that the gas burner 3 is in the combustion stopped state from the operation state of the combustion control means 30, the process proceeds from STEP 22 to STEP 2, and the zero point reference value updating means 36 restarts the 30 minute timer 40. Let it.

On the other hand, when the combustion state of the gas burner 3 is not recognized in STEP 3 and the timer 40 has timed out for 30 minutes in STEP 4, that is, when 30 minutes have elapsed after the start of power supply, or after the combustion of the gas burner 3 is stopped. When 30 minutes have elapsed, the process proceeds to STEP 5, and the zero point reference value updating means 36 performs a zero point reference value update process.

When 30 minutes have passed since the start of power supply,
The CO concentration in the vicinity of the CO sensor 20 can be assumed to be approximately 0 ppm, and even when 30 minutes have elapsed after the combustion of the gas burner 3 has stopped, ventilation in the vicinity of the CO sensor 20 can be assumed to recover to a CO concentration of approximately 0 ppm. . Therefore, the zero point reference value updating means 36 detects the output voltage V _C of the CO sensor 20 in STEP 5 and sets the output voltage V _C as a new zero point reference value Z ₀ , which has been stored in the EEPROM 32 until then. A zero-point reference value updating process is performed, which is stored in place of the point reference value Z ₀ .

By performing the zero-point reference value updating process as described above, the output voltage V _C of the CO sensor 20 and the actual CO 2 value may be changed due to various factors such as vibration and shock when the water heater 1 is installed, temperature, and humidity. Even if the correlation with the concentration fluctuates, the zero point reference value Z ₀ is updated so as to correct the fluctuation. Therefore, when the gas burner 3 is burned, incomplete combustion of the gas burner 3 is performed. It can be determined accurately.

However, the various factors described above cause the burner 3
If this occurs after 30 minutes have passed since the combustion was stopped,
Simply performing the zero point update processing in STEP 5 cannot cope with a change in the correlation between the output voltage of the CO sensor 20 and the actual CO concentration. For example, if the correlation between the output voltage of the CO sensor 20 and the actual CO concentration fluctuates 30 minutes after the combustion of the gas burner 3 is stopped and the vibration and shock occur, then the gas burner 3 when combustion is initiated, CO concentration calculating means 33 calculates the CO concentration C _R on the basis of the zero point reference values before correlation relationship varies. Therefore, the error of the CO concentration C _R calculated by the CO concentration calculating means 33 becomes larger than the actual CO concentration, and the incomplete combustion stopping means 35 accurately determines whether or not the gas burner 3 is in an incomplete combustion state. Can not judge.

Therefore, the zero point reference value updating means 36 sets
After performing the zero point reference value update processing in EP5, the gas burner 3
When the combustion stop state of step S6 is continued, STEP6 to STE
By the process of P9, the 0-point reference value updating process is performed every four hours (corresponding to the predetermined time interval of the present invention).

The zero point reference value updating means 36 first
At 6, the four-hour timer 41 (see FIG. 2) is started.
Before the start of combustion of the gas burner 3 is recognized from the operating state of the combustion control means 30 in STEP7, when the 4-hour timer 41 times out in STEP8, the STE
At P9, a zero-point reference value update process is performed as in STEP5 described above.

Then, after performing the zero point reference value updating process in STEP 9, the process proceeds to STEP 6, where the zero point reference value updating means 3
6 starts the four-hour timer 41 again. That is,
In step 7, unless it is confirmed from the operation state of the combustion control means 30 that the gas burner 3 is in the combustion state, the value is 0.
The point reference value updating means 36 sets ST
In step EP9, a zero-point reference value update process is performed.

Thus, when the water heater 1 is not used due to the absence of a user or the like and the gas burner 3 continues to stop burning, a vibration shock, a change in temperature, etc. occur during that time, and the CO sensor 20 Even if the correlation between the output voltage and the actual CO concentration fluctuates, the zero-point reference value Z ₀ is updated by the zero-point reference value updating means 36 in accordance with the fluctuation, and the EEPRO
It is stored in M32. Therefore, after that, when the water heater 1 is used and the combustion of the gas burner 3 is started, C
The O concentration calculating means 33 uses the new zero point reference value Z ₀ stored in the EEPROM 32 to calculate the CO concentration C in the combustion exhaust Z.
_R can be calculated accurately. The incomplete combustion stop means 35, based on CO concentration C _R calculated by the CO concentration calculating means 33, whether the gas burner 3 is incomplete combustion state can be accurately determined.

If it is determined in step 7 that the gas burner 3 is in the combustion state based on the state output of the combustion control means 30, the flow branches from step 7 to step 30, and the incomplete combustion stopping means 35 described above. STEP
As in steps 20 to 22, determination of incomplete combustion of the gas burner 3 and processing for stopping incomplete combustion are performed.

When the gas burner 3 is in the combustion stopped state, it is desirable that the zero point reference value updating process be performed more frequently. However, considering the effect on the life of the CO sensor 20,
In the present embodiment, the 0-point reference value updating process is performed every four hours. Therefore, the time interval of 4 hours is not strict, and is not particularly limited to 4 hours. Further, the time interval does not necessarily have to be constant.

Further, in the present embodiment, a gas water heater is described as an example of the combustion device of the present invention. However, the combustion device is not particularly limited to a gas water heater, and other types of combustion devices, for example, It may be a heating device or a cooking appliance. Further, the present invention can be applied to a combustion device using another kind of fuel, for example, petroleum.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a gas water heater provided with an incomplete combustion detection device.

FIG. 2 is a control block diagram of the incomplete combustion detection device.

FIG. 3 is an operation flowchart of the incomplete combustion detection device.

FIG. 4 is an output characteristic graph of a CO sensor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Gas water heater, 2 ... Combustion housing, 3 ... Gas burner, 4 ... Combustion fan, 5 ... Air supply port, 6 ... Exhaust port, 11 ...
Gas pipe, 13 ... Water amount sensor, 14 ... Thermistor, 15 ...
Original gas solenoid valve, 16: Main solenoid valve, 17: Gas proportional valve, 1
8 igniter, 19 frame rod, 20 CO sensor, 21 controller, 30 combustion control means, 31
... Incomplete combustion detection means, 33 ... CO concentration calculation means, 35
... Incomplete combustion stopping means, 36 ... 0-point reference value updating means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshiyuki Shibayama 2-26, Fukuzumi-cho, Nakagawa-ku, Nagoya City, Aichi Prefecture Inside Rinnai Corporation (72) Inventor Yoshihiko Takasu 2-26, Fukuzumi-cho, Nakagawa-ku, Nagoya City, Aichi Prefecture Inside Linnai Co., Ltd. (72) Yoshihiro Ishikawa 2-26, Fukuzumi-cho, Nakagawa-ku, Nagoya-shi, Aichi Prefecture Inside Linnai Corporation (72) Ikuo Takahashi 1-1-1, Kamiogi, Suginami-ku, Tokyo Nemoto Inside Special Chemical Co., Ltd. (72) Inventor Zhang Meiko Mitsumi Building, 1-1-15 Kamiogi, Suginami-ku, Tokyo Nemoto Special Chemical Co., Ltd. Nemoto Special Chemicals Co., Ltd. (72) Inventor Takashi Sugai Marunouchi Building, 1-1-1 Kamiogi, Suginami-ku, Tokyo F-term (reference) 3K003 TA01 TB04 TB07

Claims (1)

[Claims] 1. A CO concentration detecting means for outputting a voltage corresponding to a CO concentration in exhaust gas of a combustion device, and an output voltage of the CO concentration detecting device when the combustion device is in a combustion stopped state.
A zero-point reference value storage means for storing the zero-point reference value for detecting the CO concentration; and the zero-point reference value stored in the zero-point reference value storage means and the output voltage of the CO concentration detection means. CO concentration calculating means for calculating the CO concentration in the exhaust gas, and when the CO concentration calculated by the CO concentration calculating means is equal to or higher than a predetermined concentration, it is determined that the combustion device is in an incomplete combustion state, An incomplete combustion stopping device for stopping the combustion operation of the combustion device, the incomplete combustion detecting device for a combustion device comprising: And replaces the detected output voltage with the zero-point reference value stored in the zero-point reference value storage means up to that point. Store in storage means An incomplete combustion detection device for a combustion appliance, comprising a zero point reference value updating means for performing a zero point reference value updating process.