JP2001296021A - Co gas detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a CO gas detecting device to effect correction of a 0-point reference value right after installation of a gas apparatus with high precision by considering the influence of temperature after combustion. SOLUTION: An initial correction means 2a-6 performs initial correction of a 0-point reference value in a way that, not in a combustion state according to a start of operation of the gas apparatus and in a state that a detecting element is heated to a detecting temperature, the detecting output of a CO detector is stored as a fresh 0-point reference value at a 0-point reference value memory means instead of a 0-point reference value before the fresh 0-point reference value to execute initial correction of the 0-point reference value. A first combustion correcting means 2a-7 executes first combustion correction of the 0-point reference value such that the detecting output of the CO detector is stored as a fresh 0-point reference value instead of a 0-point reference value before the fresh 0-point reference value at the 0-point reference value memory means at a point of time when any influence is not exercised on correction of the 0-point reference value by temperature generated by combustion after completion of combustion during completion of the first time combustion of the gas apparatus after initial correction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CO gas detection apparatus, and more particularly to a CO gas detection apparatus for detecting the concentration of carbon monoxide gas generated due to incomplete combustion in exhaust gas discharged from gas appliances such as hot water storage gas water heaters. The present invention relates to a CO gas detection device that measures and detects an abnormal state.

[0002]

2. Description of the Related Art Conventionally, in order to detect incomplete combustion exhaust gas discharged from a gas water heater, a CO detector having a contact combustion type detection element disposed at an exhaust port portion of a main body of the gas water heater is provided. Detects abnormal conditions by measuring the concentration of flammable gas such as carbon monoxide in exhaust gas using the detection element of the CO detector, and shuts off the gas supply pipe leading to the burner with a solenoid valve as a safety device There is something like that.

In the above-mentioned CO detector, a detecting element arranged in an exhaust port portion which can contact exhaust gas constitutes a bridge circuit together with a temperature-compensating comparing element (not shown), a fixed resistor and a movable resistor. When the sensing element touches the exhaust gas, it generates heat in accordance with the concentration of carbon monoxide in the exhaust gas.
A voltage having a magnitude corresponding to the degree of imbalance is output as a detection output.

Then, the control unit inputs the detection output,
If the detection output exceeds a predetermined value set in the control unit, it is determined that the concentration of carbon monoxide gas in the exhaust gas has reached a dangerous state, and an alarm signal is output and an alarm sound is generated by a buzzer as a sounding means. It is designed to generate or shut off the gas supply source to prevent the room from being filled with carbon monoxide gas and causing a poisoning accident.

[0005] A CO detector generally has a wire diameter of φ20.
Combine a detection element in which a platinum wire of about 50 μm is formed into a coil shape and a catalyst-supported alumina is formed in a bead shape on this coil, and a comparative element in which only alumina is formed, and a protective cap is attached to this. Configuration.
It operates using the principle that the resistance value of the platinum wire increases due to the heat of reaction between the catalyst and CO and H ₂ contained in the incomplete combustion exhaust gas.

[0006] In this type of CO gas detection device, the predetermined fixed alarm level is compared with the detection output as described above, and the precondition is that whether the detection output exceeds the alarm level is determined. It is necessary to surely set the zero point reference value in a state where the carbon monoxide gas serving as a criterion for detection is not detected. Conventionally, at the factory shipment stage or the like incorporated in a gas water heater, the variable resistance in the CO detector is adjusted in advance so that the bridge circuit is in an equilibrium state, and the zero point reference value is adjusted. Had been set.

[0007] However, the zero point reference value set as described above may fluctuate due to the movement of the adjusted variable resistor due to vibration and shock during transportation of the built-in gas water heater.

When the zero point reference value fluctuates in this way, the zero point reference value in a state where carbon monoxide is not detected as a criterion for determining whether the detection output has exceeded the alarm level is out of order. I will. In such a case, the detection output including a serious error is compared with a predetermined alarm level, and although the actual concentration of carbon monoxide gas is at the alarm level, the detection device side It is determined that the alarm level has not been reached, and there is a risk that a dangerous state in which the predetermined safety device does not operate at all.

As an example of the above-mentioned hot water storage type gas water heater, for example, forced supply and exhaust (FF) using an AC 100V power supply
Type, forced exhaust (FE) type gas water heater. In this type of gas water heater, the combustion control unit of the gas water heater inputs this detection output, and when the detection output exceeds a predetermined value set in the combustion control unit, the concentration of carbon monoxide gas in the exhaust gas is reduced. Judging that a danger has occurred, an alarm signal is output and an alarm sound is generated by the buzzer as a sounding means, the gas supply source is shut off, and the room is filled with carbon monoxide gas, causing a poisoning accident. Is to prevent.

[0010] The combustion control section of the hot water storage gas water heater described above starts combustion as soon as the gas water heater is turned on after the gas water heater is installed, and raises the hot water storage temperature to a predetermined temperature. After that, the combustion is stopped, and thereafter the combustion is controlled so as to repeat the combustion and the stop so as to keep the temperature of the hot water storage unit at a predetermined value. Therefore, even if the gas water heater is turned on after the gas water heater is installed, it does not immediately start burning, but while the gas water heater is extinguished and does not generate carbon monoxide, It is configured to perform a zero point reference value correction operation of storing the output of the CO detector as a zero point reference value.

[0011]

However, in the case of a hot water storage gas water heater, while the gas water heater is extinguished and is not generating carbon monoxide, the output of the CO detector is reduced to zero.
If the temperature of the hot water storage section is increased by the subsequent combustion simply by performing the correction work of the zero point reference value stored as the point reference value, the sensing element provided at the exhaust port is affected by the temperature of the hot water storage section. , The operation is performed at a temperature different from that at the time of the zero-point reference value correction work, and the problem that the CO gas detection accuracy is affected remains.

Recently, even in a natural exhaust (CF) type water heater, a CO gas detecting device for detecting an abnormal state by measuring the concentration of carbon monoxide gas generated due to incomplete combustion in the exhaust gas to be exhausted. It is considered to incorporate.

However, this kind of hot water storage type gas water heater only has a combustion control unit which controls the hot water supply temperature as described above. Therefore, the detection output is input to the combustion control unit, and when the detection output exceeds a predetermined set value,
Judging that the concentration of carbon monoxide gas in the exhaust gas has reached a dangerous state, it is possible to output a warning signal and generate a warning sound by a buzzer as a sounding means, or to have a function to shut off the gas supply source. difficult.

Therefore, even if a CO gas detecting device is newly incorporated in this kind of simple hot water storage type gas water heater, in the conventional CO gas detecting device, the gas water heater generates carbon monoxide gas. The correction operation of the zero point reference value cannot be performed by finding a timing that is not in the state.

Of course, it is conceivable that the combustion control section of the existing hot-water storage gas water heater is newly created or re-created so that the above-described operation of correcting the zero-point reference value can be performed. A problem arises in that the redesign of the gas appliance itself such as a vessel causes a significant increase in cost.

Therefore, according to the present invention, the correction of the initial zero point reference value immediately after the installation of the gas appliance such as a hot water storage type gas water heater can be accurately performed in consideration of the influence of the temperature of the hot water storage unit and the like after combustion. It is an object to provide a CO gas detection device.

According to the present invention, there is also provided a gas heater such as a gas water heater, which is not modified, without significantly increasing the cost and without detecting carbon monoxide gas discharged from the gas heater such as a gas water heater. It is an object of the present invention to provide a CO gas detection device which can perform a correction operation of a zero point reference value at a certain timing.

[0018]

According to a first aspect of the present invention, there is provided a contact combustion type of heating a detection temperature to detect a CO gas as shown in FIG. A CO detector 1 having a detecting element 1a, a heating means 1c for heating the detecting element to the detection temperature, and outputting a detection signal corresponding to a concentration of CO gas detected by the detecting element; Heating control means 2a-1 for controlling heating of the sensing element by means of
Zero point reference value storage means 2c-1 for storing a detection signal output when no gas is detected as a zero point reference value in advance.
And a detection signal output from the CO detector based on the zero point reference value stored in the zero point reference value storage means.
A CO 2 gas detection device comprising: a determination unit 2a-2 for determining that a predetermined concentration of a gas is equal to or more than a predetermined value. Controlling the heating of the sensing element to the detected temperature and inhibiting the combustion of the gas equipment, and in a state where the gas equipment is not in a combustion state and the sensing element is heated to the detected temperature, the CO detector The detected output is stored in the zero point reference value storage means as a new zero point reference value instead of the previous zero point reference value.
Initial correction means 2a-6 for performing initial correction of the point reference value and thereafter starting combustion of the gas equipment, and first and first time of the gas equipment which has started combustion after initial correction of the zero point reference value by the initial correction means. When the combustion is completed and the temperature due to combustion after the combustion of the gas appliance has no effect on the correction of the zero point reference value, the detection output of the CO detector is set as a new zero point reference value and the previous zero point reference value is set. A first-time combustion correction means 2a-7 for correcting the zero-point reference value by storing it in the zero-point reference value storage means instead of the value.
O gas detector exists.

According to the first aspect of the present invention, a contact combustion type detecting element 1 which is heated to a detection temperature and detects CO gas is provided.
a is heated to the detection temperature by the heating means 1c, and the CO detector 1 outputs a detection signal corresponding to the concentration of the CO gas detected by the detection element. The heating control means 2a-1 controls heating of the sensing element by the heating means. The determination unit 2a-2 determines that the detection signal output from the CO detector is predetermined for a predetermined concentration of the CO gas based on the zero point reference value stored in the zero point reference value storage unit 2c-1. It is determined that the value is equal to or greater than the value.

The initial correction means 2a-6 controls the heating control means to control the heating of the sensing element by the heating means to the detected temperature and inhibits the combustion of the gas equipment in response to the start of the operation of the gas equipment. Is not in a combustion state and the sensing element is heated to the sensing temperature,
The detection output of the detector is stored as a new zero-point reference value in the zero-point reference value storage means instead of the previous zero-point reference value.
Since the initial correction of the point reference value is performed and then the combustion of the gas equipment is started, the initial correction of the zero point reference value is performed simply by outputting a combustion control signal to the gas equipment in response to the start of operation from the gas equipment. After the state is formed and the initial correction is performed, the gas water heater can be automatically returned to the original operating state. When the first combustion of the gas appliance that has started combustion after the initial correction of the zero point reference value is completed, the first combustion correction means 2a-7 reduces the temperature due to the combustion after the combustion of the gas appliance to 0 point. When the correction of the reference value is no longer affected, C
Since the detection output of the O detector is stored in the zero point reference value storage means instead of the previous zero point reference value as a new zero point reference value and the zero point reference value is corrected, the heat after combustion of the gas appliance is obtained. The zero point reference value can be corrected in consideration of the detection output of the CO detector that has changed.

According to a second aspect of the present invention, there is provided a contact combustion type detecting element 1a which is heated to a detection temperature and detects a CO gas.
Heating means 1c for heating the detection element to the detection temperature, a CO detector 1 for outputting a detection signal according to the concentration of CO gas detected by the detection element, and a heating element for detecting the detection element by the heating means. Heating control means 2a-1 for controlling heating
A zero-point reference value storage means for storing in advance a detection signal output when the CO detector does not detect CO gas as a zero-point reference value; A CO gas detection apparatus comprising: a determination unit 2a-2 configured to determine that a detection signal output from the CO detector is equal to or higher than a predetermined value with respect to a predetermined concentration of CO gas based on a point reference value. , An operation start signal input means 2a-3 for inputting an operation start signal indicating an operation start of the hot water gas heater, and a combustion control signal output means 2a for outputting a combustion control signal for inhibiting combustion of the hot water gas heater. -4
A combustion signal input unit 2a-5 for inputting a combustion signal indicating that the hot water type gas water heater is in a combustion state; and the heating control unit in response to the input of the operation start signal, the heating control unit receiving the detection element by the heating unit. And controlling the heating to the detected temperature and outputting the combustion control signal to the combustion control signal output means, in a state where the hot water storage type gas water heater is not in the combustion state and the detection element is heated to the detected temperature. The detected output of the CO detector is stored as a new zero-point reference value in the zero-point reference value storage means in place of the previous zero-point reference value to perform initial correction of the zero-point reference value. Initial correction means 2a-6 for terminating the output of the combustion control signal by the signal output means to bring the hot water gas water heater into a combustion state, and the combustion state after the initial correction of the zero point reference value by the initial correction means. When the first combustion of the stored hot water gas water heater is completed and the input of the combustion signal is lost, the temperature due to the combustion after the completion of the combustion of the hot water gas heater affects the correction of the zero point reference value. At which point C
The first combustion correction means 2a- which corrects the zero-point reference value by storing the detection output of the O detector as a new zero-point reference value in place of the previous zero-point reference value in the zero-point reference value storage means.
And CO gas detecting device.

According to the second aspect of the present invention, the contact combustion type detecting element 1 for detecting the CO gas by being heated to the detection temperature.
a is heated to the detection temperature by the heating means 1c, and the CO detector 1 outputs a detection signal corresponding to the concentration of the CO gas detected by the detection element. The heating control means 2a-1 controls heating of the sensing element by the heating means. The determination unit 2a-2 determines that the detection signal output from the CO detector is predetermined for a predetermined concentration of the CO gas based on the zero point reference value stored in the zero point reference value storage unit 2c-1. It is determined that the value is equal to or greater than the value.

The initial correcting means 2a-6 controls the heating control means to heat the sensing element to the detected temperature by the heating means in response to the input of the operation start signal to the operation start signal input means 2a-3. And causing the combustion control signal output means 2a-4 to output a combustion control signal for inhibiting the combustion of the hot water storage gas water heater, so that the hot water storage gas water heater is not in a combustion state and the detection element is heated to the detection temperature. In the above, the detection output of the CO detector is stored as a new zero point reference value in the zero point reference value storage means in place of the previous zero point reference value to perform initial correction of the zero point reference value, and thereafter, the combustion control signal output Since the output of the combustion control signal by the means is terminated and the hot water storage gas water heater is brought into a combustion state, an operation start signal is input from the hot water storage gas water heater and a combustion control signal is sent to the hot water storage gas water heater. Just force, to form a state in which the initial correction of the zero point reference value, after the initial correction can be returned automatically original operation state storage type gas water heater. In addition, the first combustion correction means 2a-7 performs the first combustion of the hot water storage gas water heater that has started the combustion after the initial correction of the zero point reference value and the first combustion of the hot water storage gas water heater after the completion of the first combustion. When the temperature due to combustion no longer affects the correction of the zero point reference value, the detection output of the CO detector is stored in the zero point reference value storage means as a new zero point reference value instead of the previous zero point reference value. Therefore, the zero point reference value can be corrected in consideration of the detection output of the CO detector changed by the heat of the hot water storage unit of the hot water type gas water heater.

According to a third aspect of the present invention, there is provided the second aspect of the invention.
In the O gas detection device, the heating control unit causes the heating unit to heat the detection element to the detection temperature in response to the input of the combustion signal, and performs the detection by the heating unit when the input of the combustion signal stops. The present invention resides in a gas detection device for terminating heating of an element.

According to the third aspect of the present invention, in addition to the function of the second aspect, the heating control means controls the heating means in response to the input of the combustion signal to the combustion signal input means 2a-5. Since the heating of the sensing element by the heating means is terminated when the sensing element is heated to the sensing temperature and the input of the combustion signal stops, the combustion of the hot-water gas heater only requires input of the combustion signal from the hot-water gas heater. The CO gas detection operation is performed only during the operation.

According to a fourth aspect of the present invention, in the CO gas detecting apparatus according to the second or third aspect, the first correction means measures time for a predetermined time after the input of the combustion signal is stopped. When the time keeping means measures a predetermined time, it is assumed that the temperature due to combustion after the completion of combustion of the hot water storage gas water heater has no influence on the correction of the zero point reference value, and the correction is performed. It is a characteristic CO gas detector.

According to the fourth aspect of the invention, in addition to the operation of the second or third aspect, the first combustion correction means 2a
-7 is a correction of the zero-point reference value when the temperature due to the combustion after the completion of the combustion of the hot water type gas water heater is measured when the clocking means 2c-2 measures the predetermined time after the input of the combustion signal is stopped. Since the correction is performed on the assumption that there is no influence on the first combustion correction, the first combustion correction can be performed in a timely manner only by measuring a certain time.

According to a fifth aspect of the present invention, in the CO gas detecting apparatus according to the second or third aspect, the first correction means detects the CO based on the resistance value of the detection element after the input of the combustion signal is stopped. It has temperature detecting means 2a-8 for detecting the temperature of the detector, and when the temperature detected by the temperature detecting means becomes a temperature which does not affect the correction of the zero point reference value,
The correction is performed by a CO gas detection device.

According to the fifth aspect of the invention, in addition to the function of the second or third aspect, the first combustion correction means 2a
-7 is C detected by the temperature detecting means 2a-8 based on the resistance value of the detecting element after the input of the combustion signal is stopped.
Since the correction is performed when the temperature of the O detector reaches a temperature that does not affect the correction of the zero point reference value, the timing for the first combustion correction can be easily and accurately found.

According to a sixth aspect of the present invention, in the CO gas detecting device according to any one of the second to fifth aspects, the operation start signal input means detects the rise of the power supply voltage of the hot water supply type gas water heater. C characterized by being input as
O gas detector exists.

According to the sixth aspect of the present invention,
In addition to the operation of the invention described in any one of the fifth to fifth aspects, the operation start signal input means receives the rise of the power supply voltage of the hot water storage gas water heater as an operation start signal, and receives power supply from the hot water supply gas water heater. Only by this, it is possible to know the start of the operation of the hot water gas heater.

According to a seventh aspect of the present invention, in the CO gas detecting device according to any of the second to sixth aspects, the combustion signal input means inputs a signal generated by a frame rod of the gas water heater as a combustion signal. A CO gas detection device.

According to the seventh aspect of the present invention,
In addition to the operation of the invention described in any one of the sixth to sixth aspects, the combustion signal input means inputs a signal generated by the flame rod of the gas water heater as a combustion signal, so that a signal for monitoring a combustion state in the gas water heater is generated. Can be diverted as it is.

According to an eighth aspect of the present invention, in the CO gas detecting apparatus according to any one of the first to seventh aspects, the zero point reference value is stored as a new zero point reference value instead of the previous zero point reference value. The CO gas detection device further comprises abnormality determination means 2a-9 for determining that the detection element has an abnormality when the detection output of the CO detector for storing in the means is not within a predetermined range. Exist.

According to the invention of claim 8, claims 1 to 1 are provided.
7, the abnormality determining means 2
a-9 is a CO for storing in the zero point reference value storage means as a new zero point reference value in place of the previous zero point reference value.
When the detection output of the detector is not within the predetermined range, it is determined that there is an abnormality in the detection element, so that an abnormality of the detection element or the CO detector can be detected in the process of correcting the zero point reference value.

[0036]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a circuit block diagram showing one embodiment of a CO gas detection device according to the present invention, which is configured to be applied to an existing hot-water gas heater as an existing gas appliance. In the figure, the CO gas detector is
In order to detect incomplete combustion exhaust gas discharged from a hot water storage gas water heater (not shown), a CO detector 1 having a contact combustion type detection element 1a disposed at an exhaust port portion of a main body of the gas water heater is provided. The contact combustion type detection element 1a is a constant current application circuit 1c which is a heating means for heating the detection element to a detection temperature.
Is connected in series with the temperature-compensating reference element 1b. A fixed resistor and a movable resistor (not shown) that constitute a bridge circuit together with the sensing element 1a and the reference element 1b connected in series generate heat according to the concentration of carbon monoxide in the exhaust when the sensing element 1a contacts the exhaust, As the resistance value changes, the equilibrium state of the bridge circuit breaks down,
A detection output circuit 1d of the CO detector 1 that outputs a voltage having a magnitude corresponding to the degree of imbalance as a detection output is formed.

The CO gas detector also has a central processing unit (CPU) 2 functioning as heating control means 2a-1 for controlling the heating of the detecting element 1a by the constant current applying circuit 1c.
and a microcomputer (hereinafter abbreviated as μCOM) 2 incorporating a. The μCOM 2 has a built-in ROM 2b, which is a read-only memory (not shown), and the CPU 2a performs processing according to a program stored in the ROM 2b.

The μCOM 2 also has a built-in readable / writable RAM 2c having a work area used as a work area in the process of processing by the CPU 2a and a memory area for temporarily storing various data. In the RAM 2c, a zero-point reference value storage area serving as a zero-point reference value storage means 2c-1 for storing a detection signal output when the CO detector does not detect CO gas as a zero-point reference value in advance. The CPU 2a determines that the detection signal output from the CO detector is equal to or greater than a predetermined value with respect to the predetermined concentration of the CO gas based on the zero point reference value stored in the zero point reference value storage area. It also functions as the judgment means 2a-2 for judging that the condition has been satisfied. As described above, the CPU 2a which also functions as the determination unit 2a-2,
When it is determined that the detection signal output from the CO detector is equal to or higher than a predetermined value with respect to the predetermined concentration of the CO gas, a buzzer (not shown) is sounded, or an indicator (not shown) is turned on to emit the CO gas. A warning signal for warning that is at the dangerous concentration is output via the warning signal output terminal 3d.

The CO gas detection device also has a power supply terminal 3a for receiving power supply via a power supply circuit of the hot water supply type gas water heater, and the CPU 2a of the μCOM 2 monitors the rise of the power supply voltage of the power supply terminal 3a, It also functions as an operation start signal input means 2a-3 for inputting as an operation start signal indicating the start of operation of the vessel.

The CO gas detecting device further includes, for example, a signal line terminal 3b to which a signal line for opening and closing the main valve of the gas water heater is connected, and the CPU 2a of the μCOM 2 sets the signal line terminal 3b to L level. A combustion control signal output means 2a-4 for outputting a combustion control signal for stopping the gas supply to the gas water heater and inhibiting the gas water heater from burning.
Also functions as. In addition, as a method of prohibiting combustion of the gas water heater, specifically, it is generally considered that the method is performed by closing a main valve which is provided in a pipe for supplying gas to a burner and is in an open state. When the CPU 2a functioning as the combustion control signal output means 2a-4 determines that the predetermined concentration of the CO gas is equal to or more than a predetermined value, the CPU 2a may cause a human body if the concentration of the CO gas further increases. To avoid danger, set the signal line terminal 3b to L level,
It is preferable to output as a combustion control signal for inhibiting the combustion of the gas water heater.

The CO gas detecting apparatus further includes a signal input terminal 3c for inputting a signal from a frame rod provided for the gas water heater to detect during combustion.
The M2 CPU 2a monitors the signal at the signal input terminal 3c and also functions as combustion signal input means 2a-5 for inputting as a combustion signal indicating that the gas water heater is in a combustion state.

Further, the μCOM provided in the CO gas detecting device
In response to the start of the operation of the hot-water gas water heater, for example, as described above, the CPU 2a detects the rising of the power supply voltage of the power supply terminal 3a as the operation start signal, and detects the constant current application circuit 1c. Element 1a and reference element 1
b to control the constant current to be supplied to the ground,
By heating the detection element to the detection temperature and setting the signal line terminal 3b to the L level, the main valve in the valve open state is closed to stop the gas supply to the hot water storage type gas water heater, and the hot water storage gas is supplied. The detection output circuit 1d of the CO detector 1 outputs an output as a combustion control signal for inhibiting combustion of the water heater, in a state where the hot water gas heater is not in a combustion state and the detection element 1a is heated to the detection temperature. The zero point reference value storage means 2 formed in the RAM 2c instead of the previous zero point reference value using the detected output as a new zero point reference value.
It also serves as an initial correction means 2a-6 which stores the value in c-1 to perform an initial correction of the zero point reference value, and thereafter terminates the output of the combustion control signal to bring the hot water type gas water heater into a combustion state.

Further, the μCOM provided in the CO gas detecting device
The second CPU 2a automatically performs the first combustion of the hot water storage type gas water heater that has started the combustion after the initial correction of the zero point reference value by the initial correction means when the temperature of the hot water storage unit reaches a predetermined set temperature. At the end of the operation, when the temperature due to the combustion after the completion of the combustion of the hot water storage gas water heater has no effect on the correction of the zero point reference value, the detection output of the CO detector is set as a new zero point reference value and the previous zero point reference value is set. It also functions as first combustion correction means 2a-7 which stores the value in the zero point reference value storage area in place of the value and corrects the zero point reference value.

As described above, the CPU 2a of the μCOM 2 functioning as the heating control means 2a-1
In response to the input of the combustion signal to c, the constant current applying circuit 1c is supplied with a constant current to the ground through the detecting element 1a and the reference element 1b. The supply of the constant current to the ground through the reference element 1b is stopped, and the heating of the detection element 1a is terminated.

As described above, the CPU 2a of the μCOM 2 functioning as the first-time correction means 2a-7 also measures RA for measuring a certain time after the input of the combustion signal is stopped.
The timekeeping area formed in M2c is provided as timekeeping means 2c-3, and when the timekeeping area performs timekeeping for a certain time, the temperature due to combustion after the gas water heater finishes burning may affect the correction of the zero point reference value. Assuming that it has disappeared, the first correction described above is performed. This first correction method can be performed very simply because it is only necessary to measure the time after the input of the combustion signal is stopped.

Note that the CPU 2a of the μCOM 2 functioning as the first correction means 2a-7 corrects the temperature due to combustion after the gas water heater finishes combustion to the zero-point reference value when the time measurement area measures a predetermined time. 1 as no longer affected
Instead of performing the second correction, the temperature detection circuit 1 detects the temperature based on the resistance value of the detection element 1a and outputs a temperature signal of a magnitude corresponding to the temperature after the combustion signal is no longer input.
e as a temperature detection means 2a-8 for detecting the temperature of the CO detector, and when the temperature detected by this function becomes a temperature which does not affect the correction of the zero point reference value, 1 The second correction may be performed. In such a case, the first correction can be executed at a very appropriate time depending on the actual temperature of the sensing element 1a, so that a more accurate first correction can be performed in a short time.

Further, the μCO provided in the CO gas detecting device
The CPU 2a of M2 determines that the detection output of the CO detector 1 for storing the new zero point reference value in the zero point reference value storage area formed in the RAM 2c instead of the previous zero point reference value is within a predetermined range. If not, it also functions as abnormality determining means 2a-9 for determining that there is an abnormality in the detecting element 1a. As described above, when the CPU 2a of the μCOM 2 that also functions as the abnormality determination unit 2a-9 determines that the detection element 1a has an abnormality, the detection element 1a or the CO detector 1 including the detection element 1a functions normally thereafter. An abnormal signal for sounding a buzzer (not shown) or turning on an indicator (not shown) to warn that the sensing element or detector is in an abnormal state and the element or detector needs to be replaced. The abnormal signal output terminal 3
Output via e.

The operation of the CO gas detecting device whose configuration has been described with reference to FIG. 2 will be described below. The CO gas detector shown in the figure is connected to an outlet of a gas water heater (not shown) by AC100V.
When plugged into a power supply, power is supplied to each part of the water heater main body via the power supply circuit of the gas water heater. When the power is turned on, the control circuit of the gas water heater enters an operating state. However, power is also supplied from the power circuit of the gas water heater to the power terminal 3a of the CO detection device, and accordingly, the CPU 2a of the μCOM 2 also starts operating. .

CPU 2a of μCOM2 turned on
Knows the start of operation of the gas water heater by this, and outputs a combustion control signal for setting the signal line terminal 3b to L level in order to inhibit the gas water heater from starting the combustion operation so that the gas water heater does not start the combustion operation. Output. By setting the signal line terminal 3b to the L level, the main valve in the valve open state is closed to stop the gas supply to the gas water heater and inhibit the gas water heater from burning.

Thereafter, the detecting element 1 is added to the constant current applying circuit 1c.
A constant current is supplied to the ground through a and the reference element 1b to heat the detection element to the detection temperature. For example, after a certain period of time elapses in order for the detection element 1a to heat to the detection temperature, the detection output output by the detection output circuit 1d of the CO detector 1 is captured, and the captured detection output falls within a predetermined range. Determine if there is. As a result of this judgment,
When the detected output is within the range, the captured detection output is set as a new zero point reference value and replaced with the previous zero point reference value.
The initial value of the zero-point reference value is corrected by storing it in the zero-point reference value storage area formed in M2c. After that, the output of the combustion control signal is terminated to release the combustion prohibition state of the gas water heater, so that the gas water heater becomes a combustion state or a combustible state. When the detection output is not within the predetermined range, an abnormal signal is output and the detection element 1a or the CO detector 1 is output.
Alerts you of a replacement. The alarm that is issued by the output of the abnormal signal is continued until a reset switch (not shown) is operated.

When the gas water heater is of the hot water storage type, the combustion state is automatically started by plugging the outlet of the gas water heater into the AC 100 V power supply. Starts combustion, and a combustion signal is input.
The heating state to the detected temperature of “a” is maintained, and C is determined based on the 0-point reference value stored in the 0-point reference value storage area during this period.
It is determined whether the detection signal output from the O detector is equal to or higher than a predetermined value for a predetermined concentration of the CO gas. As a result of this determination, when the CO gas having a predetermined concentration or more is not detected, the detection signal output from the CO detector is repeatedly taken until the input of the combustion signal stops, and this detection signal is predetermined for the predetermined concentration of the CO gas. Repeat the determination of whether the value is greater than or equal to the value. CO of a predetermined concentration or more
When the gas is detected, an alarm signal is output to give an alarm.

When the input of the combustion signal is stopped after the first combustion, the detecting element 1 is connected to the constant current application circuit 1c.
without stopping the supply of a constant current to the ground via the reference element 1a and the reference element 1b.
The detection output of the detector is fetched, and the fetched detection output is stored as a new zero-point reference value in a zero-point reference value storage area formed in the RAM 2c instead of the previous zero-point reference value. The first combustion correction is performed. After performing the first combustion correction, the operation of heating the detection element 1a to the detection temperature is stopped, and a subsequent combustion signal is input. The alarm performed by the output of the alarm signal is continued until a reset switch (not shown) is operated.

When a combustion signal from the second or subsequent combustion is input after the combustion of the gas water heater starts, the constant current application circuit 1c
A constant current is supplied to the ground through the detection element 1a and the reference element 1b to heat the detection element to the detection temperature. After the detection element 1a is heated to the detection temperature, for example, after a certain period of time, the CO detector 1 Captures the detection output output from the detection output circuit 1d of FIG.
A determination is made as to whether or not the predetermined concentration of the O gas is equal to or more than a predetermined value. As a result of the determination, when the CO gas having the predetermined concentration or more is not detected, the output of the CO detector is kept until the input of the combustion signal stops. And repeatedly determines whether the detected signal is equal to or higher than a predetermined value for a predetermined concentration of the CO gas. When the detection of the CO gas having the predetermined concentration or more is performed, the warning signal is output and the warning is performed as described above.

When the combustion operation of the gas water heater is completed and the input of the combustion signal stops, the operation of heating the sensing element 1a to the detected temperature is stopped and the input of the next combustion signal is awaited.

In order to determine that the temperature due to combustion after the gas water heater has completed combustion has no effect on the correction of the zero point reference value, a predetermined time is measured or the temperature signal from the temperature detection circuit 1e is used. Although it can be used, using the temperature signal from the temperature detection circuit 1e provided for performing temperature compensation does not require any additional means, and increases the correction accuracy.

The details of the operation of the CO gas detection device outlined above are described in detail in the description of the CP of μCOM2 provided in the CO gas detection device.
A description will be given below with reference to a diagram showing a process performed by U2a according to a predetermined program and a flowchart of the diagram.

The CPU 2a starts the operation when the power supply voltage is supplied to the power supply terminal 3a from the power supply circuit of the gas water heater when the outlet of the gas water heater is plugged into the AC 100V power supply. Combustion control signal to water heater 3
The combustion from the gas water heater is prohibited by outputting from b. Thereafter, the process proceeds to step S2, in which the constant current application circuit 1c supplies a constant current to the ground through the detection element 1a and the reference element 1b to start heating. In step S3, the detection element 1a is required to detect CO gas. When the temperature is increased to the detection temperature and the determination in step S3 becomes YES, the process proceeds to step S4, where the detection output of the CO detector 1 is captured.

Thereafter, it is determined whether or not the detection output taken in step S5 is within a predetermined range. If the value is not within the predetermined range and the determination in step S5 is NO, the process proceeds to step S6, and an alarm signal for alarming that the detection element 1a or the CO detector 1 is abnormal is output via the terminal 3e. If the detection output is within the predetermined range and the determination in step S5 is YES, the process proceeds to step S7, where the fetched detection output is set as a new zero point reference value in the RAM 2c instead of the previous zero point reference value. The initial correction of the 0-point reference value is performed by storing it in the point reference value storage area.
Thereafter, the process proceeds to step S8, where the combustion control signal output in step S1 is eliminated, and the output of the combustion control signal is terminated. In the hot water storage gas water heater, when the combustion prohibition is lifted, the first combustion is automatically started so that the hot water storage temperature becomes the predetermined temperature, and thereafter, the combustion and the combustion stop are repeated so as to keep the predetermined temperature.

Since the first combustion starts automatically,
The constant current from the constant current application circuit 1c is continuously supplied to the ground through the detection element 1a and the reference element 1b, and the detection element 1a is kept in a heated state. Next, in step S9, the detection output of the CO detector 1 is fetched, and it is determined whether or not the fetched detection output is equal to or higher than a value corresponding to a predetermined concentration.

If the value is equal to or higher than the predetermined concentration, the process proceeds to step S10, where an alarm signal is output to the terminal 3d,
An alarm is generated by alarm means (not shown) indicating that the gas is at a dangerous level. This alarm signal can also be used to close the main valve of the gas water heater to shut off the gas supply and end dangerous combustion. NO in step S9
, That is, when the detected output does not correspond to the predetermined concentration or more, the process proceeds to step S11 to determine whether or not the combustion signal is input to the terminal 3c. When the combustion signal is input and the determination in step S11 is YES, it is necessary to monitor the CO gas of the gas water heater, so the flow returns to step S9 to continue monitoring the concentration of the CO gas discharged from the gas water heater. Do. NO in step S11
When the input of the combustion signal is no longer performed, the first combustion is completed and the temperature of the hot water storage unit rises to a predetermined temperature. Therefore, the process proceeds to step S12, and waits until the temperature of the detection element 1a decreases and the temperature due to combustion after the first combustion of the gas water heater has no influence on the correction of the zero point reference value.
After the combustion of the gas water heater, the temperature due to the combustion decreases so as not to affect the correction of the zero-point reference value, and when the determination in step S12 becomes YES, the process proceeds to step S13 to take in the detection output, and take in this detection output. The detection output is set as a new zero point reference value and RA is replaced with the previous zero point reference value.
The first combustion correction of the zero-point reference value is performed by storing it in the zero-point reference value storage area formed in M2c. Next step S1
After performing the first combustion correction for correcting the zero-point reference value that fluctuates according to the temperature of the hot water storage unit that has risen by the first combustion in step 4, the heating is stopped in step S15, and the process proceeds to step S16. Wait for the input of a combustion signal generated by the start of combustion of the gas water heater.

If there is a combustion signal input and the determination in step S16 is YES, the flow advances to step S17 to cause the constant current application circuit 1c to supply a constant current to the ground through the detecting element 1a and the reference element 1b, thereby starting heating. In step S18, the detection element 1a waits until it is heated to, for example, a detection temperature necessary for detecting the CO gas, and then in step S19, the detection output of the CO detector 1 is captured. Then, in the next step S20, it is determined whether or not the detection output of the CO detector 1 captured in step S19 is equal to or higher than a value corresponding to a predetermined concentration. If the value is equal to or more than the predetermined concentration, the process proceeds to step S21, where an alarm signal is output to the terminal 3d, an alarm is generated by an alarm means (not shown) indicating that the CO gas is at a dangerous level, and the main function of the gas water heater is performed. Close valve to cut off gas supply and end dangerous combustion.

When the determination in step S20 is NO, that is, when the detected output does not correspond to the predetermined concentration or more, the process proceeds to step S22 to determine whether or not the combustion signal is input to the terminal 3c. Is input and when the determination in step S22 is YES, it is necessary to monitor the CO gas of the gas water heater.
Then, the detection output of the CO detector 1 is taken in, and in step S20, the concentration monitoring of the CO gas discharged from the gas water heater is continuously performed. If the determination in step S22 is NO and there is no input of the combustion signal, the process proceeds to step S23, where the detection element 1a and the reference element 1
ending the supply of constant current to ground through b,
After the heating of the detecting element 1a is stopped, the above-described step S1 is performed.
6, the process waits for the next gas water heater to burn, and thereafter, every time there is combustion, the steps S16 to S23 are repeated.

According to the above-described embodiment, in response to the input of the operation start signal, the detection element 1a is heated to the detection temperature, and the combustion control signal is output to prohibit the combustion of the hot water storage gas water heater. In the state where the gas water heater is not in the combustion state and the detection element 1a is heated to the detection temperature, the detection output of the CO detector 1 is set as a new zero point reference value and replaced with the previous zero point reference value. Since the zero point reference value is initially corrected by being stored in the point reference value storage means, and then the fuel gas water heater is brought into a combustion state, an operation start signal is input from the gas water heater and the combustion control is performed on the gas water heater. By simply outputting a signal, a state in which the initial correction of the zero point reference value is performed is formed, and after performing the initial correction, the gas water heater can be automatically returned to the original operation state. When the first-time combustion of the hot water storage gas water heater that started the combustion after the initial correction of the zero point reference value is completed, the temperature due to the combustion after the completion of the combustion of the hot water storage gas water heater corrects the zero point reference value. At the time when the influence on the zero point is no longer detected, the zero point reference value is corrected by storing the detected output of the CO detector as a new zero point reference value in the zero point reference value storage means instead of the previous zero point reference value. In addition, the zero point reference value can be corrected in consideration of the detection output of the CO detector changed by the heat of the hot water storage unit of the hot water storage gas water heater.

Further, the detection element 1a is heated to the detection temperature in response to the input of the combustion signal, and the heating of the detection element 1a is terminated when the input of the combustion signal is stopped.
Only by inputting a combustion signal from the gas water heater, the CO gas detection operation is performed only during the combustion operation of the gas water heater.

Further, when a certain period of time is measured after the input of the combustion signal is stopped, the correction is performed assuming that the temperature due to the combustion after the combustion of the gas water heater has no influence on the correction of the zero point reference value. The first combustion correction can be performed at an appropriate time only by measuring a certain time.

Further, after the input of the combustion signal is stopped, the temperature of the CO detector becomes 0 based on the resistance value of the detection element.
Since the first combustion correction is performed when the temperature does not affect the correction of the point reference value, the timing for the first combustion correction can be easily and accurately found.

Since the rise of the power supply voltage of the gas water heater is input as an operation start signal, the start of operation of the gas water heater can be known only by receiving power supply from the gas water heater.

Further, since the signal generated by the flame rod of the gas water heater is input as a combustion signal, the signal for monitoring the combustion state in the gas water heater can be diverted as it is.

When the detection output of the CO detector for storing the new zero point reference value in place of the previous zero point reference value is not within a predetermined range, it is determined that the detection element 1a is abnormal. In the course of the operation of correcting the zero point reference value, it is possible to detect an abnormality of the detection element or the CO detector.

[0070]

As described above, according to the first aspect of the present invention, the CO changed by the heat after combustion of the gas appliance.
Since the zero-point reference value can be corrected in consideration of the detection output of the detector, the initial zero-point reference value can be accurately corrected immediately after installation of the gas equipment, taking into account the effect of temperature after combustion. A CO gas detection device is obtained.

According to the first aspect of the present invention, the CO detection changed by the heat after combustion of the gas appliance can be obtained only by inputting the operation start signal from the gas appliance and outputting the combustion control signal to the gas appliance. The zero point reference value can be corrected in consideration of the detection output of the gas equipment, so that the existing gas equipment is not modified and the cost is not significantly increased, and the state in which the carbon monoxide gas discharged from the gas equipment is not detected A CO gas detection device that can perform the correction operation of the zero point reference value at a certain timing can be obtained.

According to the second aspect of the present invention, an operation start signal is input from the hot water storage gas water heater, and a combustion control signal is output to the hot water storage gas water heater, so that the hot water storage gas water heater can store the hot water. Since the zero point reference value can be corrected in consideration of the detection output of the CO detector that has changed due to heat in the section, the existing hot water storage gas water heater is not changed, without significantly increasing the cost. A CO gas detection device is provided in which the timing at which the carbon monoxide gas discharged from the water heater is not detected is formed so that the zero-point reference value can be corrected.

According to the third aspect of the present invention, in addition to the effect of the second aspect of the present invention, only by inputting a combustion signal from the hot water storage gas water heater, the CO gas is supplied only during the combustion operation of the hot water storage gas water heater. Since the detection operation is performed, it is possible to eliminate unnecessary heating except when detecting CO gas in the detection element without changing the existing hot-water storage gas water heater without significantly increasing the cost. A CO gas detector capable of being obtained is obtained.

According to the fourth aspect of the present invention, the first combustion correction can be performed in a timely manner only by measuring a certain time, so that the first combustion correction can be performed in addition to the effect of the second or third aspect of the invention. The CO gas detection device that can easily and accurately find the timing for the CO gas is obtained.

According to the fifth aspect of the present invention, it is possible to easily and accurately find the timing for the first combustion correction. A CO gas detection device capable of performing the first combustion correction of the point reference value is obtained.

According to the sixth aspect of the present invention, the operation start of the hot water storage gas water heater can be known only by receiving power supply from the hot water storage gas water heater. In addition to the effects of the invention described above, it is possible to obtain a CO gas detection device that can accurately correct a zero-point reference value for a hot-water storage gas water heater whose operation is started by power supply.

According to the seventh aspect of the invention, the signal for monitoring the combustion state in the hot water type gas water heater can be diverted as it is, so that the effect of the second aspect of the present invention can be obtained. In addition, a CO gas detection device which can operate in synchronization with combustion of the hot water gas heater is obtained.

According to the eighth aspect of the present invention, an abnormality of the detection element or the CO detector can be detected in the process of correcting the zero point reference value. In addition to the effects of the present invention, it is possible to obtain a CO gas detection device that does not need to separately detect an abnormality of a detection element or a CO detector.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a CO gas detection device according to the present invention.

FIG. 2 is a block diagram showing an embodiment of a CO detection device configured for a hot water storage type gas water heater according to the present invention.

FIG. 3 is a flowchart showing a part of a process performed by a CPU in μCOM in FIG. 2;

FIG. 4 is a flowchart showing another part of the processing performed by the CPU in μCOM in FIG. 2;

[Explanation of symbols]

 Reference Signs List 1 CO detector 1a Sensing element 1c Heating means (constant current application circuit) 2a-1 Heating control means (CPU) 2a-2 Judging means (CPU) 2a-3 Operation start signal input means (CPU) 2a-4 Combustion control signal Output means (CPU) 2a-5 Combustion signal input means (CPU) 2a-6 Initial correction means (CPU) 2a-7 First combustion correction means (CPU) 2a-8 Temperature detection means (CPU) 2a-9 Abnormality judgment means (CPU) 2c-1 Zero point reference value storage means (RAM) 2c-2 Clocking means (RAM)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaru Matsuno 23 Minamikashima, Futamata-machi, Tenryu-shi, Shizuoka Prefecture Inside Yazaki Keiki Co., Ltd. (72) Inventor Daisuke Osumi 1-5-20 Kaigan, Minato-ku, Tokyo Tokyo Gas Stock In-house (72) Inventor Masahiro Yahagi 1-5-20 Kaigan, Minato-ku, Tokyo Tokyo Gas Co., Ltd. F-term (reference) 3K003 EA02 FA05 FB10 GA02 TA02 TB07 TC03 TC08 XB03 XB04 XC00

Claims (8)

[Claims] 1. A contact combustion type detecting element for detecting a CO gas by being heated to a detection temperature, and a heating means for heating the detection element to the detection temperature, wherein the CO gas detected by the detection element is detected. A CO detector that outputs a detection signal corresponding to a concentration, a heating control unit that controls heating of the detection element by the heating unit, and a detection signal that is output when the CO detector does not detect CO gas. A zero-point reference value storage means for storing in advance as a zero-point reference value; and a detection signal output from the CO detector based on the zero-point reference value stored in the zero-point reference value storage means. A CO gas detection device for a gas appliance, comprising: a determination unit that determines that the concentration has reached a predetermined value or more, wherein the heating control unit controls the heating unit in response to the start of the operation of the gas appliance. Detection Control the heating of the gas detector to the detected temperature and inhibit the combustion of the gas water heater, and in a state where the gas appliance is not in a combustion state and the detecting element is heated to the detected temperature, the detection output of the CO detector is detected. As a new zero-point reference value, in place of the previous zero-point reference value, stored in the zero-point reference value storage means to perform an initial correction of the zero-point reference value, and thereafter, start the combustion of the gas appliance. When the first first combustion of the gas appliance that started the combustion after the initial correction of the zero point reference value by the initial correction means is completed,
At the time when the temperature due to the combustion after the combustion of the gas appliance has no influence on the correction of the zero point reference value, the detected output of the CO detector is set as a new zero point reference value and the zero point reference value is replaced with the previous zero point reference value. A CO gas detection device further comprising first combustion correction means for correcting a zero-point reference value by storing it in a point reference value storage means. 2. A contact combustion type detection element for detecting CO gas by being heated to a detection temperature, and heating means for heating the detection element to the detection temperature. A CO detector that outputs a detection signal corresponding to a concentration, a heating control unit that controls heating of the detection element by the heating unit, and a detection signal that is output when the CO detector does not detect CO gas. A zero-point reference value storage means for storing in advance as a zero-point reference value; and a detection signal output from the CO detector based on the zero-point reference value stored in the zero-point reference value storage means. An operation start signal input unit for inputting an operation start signal indicating an operation start of the hot water storage type gas water heater, comprising: a CO gas detection device comprising: a determination unit configured to determine that the concentration has reached a predetermined value or more. , Hot water storage Combustion control signal output means for outputting a combustion control signal for inhibiting the combustion of the gas water heater, combustion signal input means for inputting a combustion signal indicating that the hot water type gas water heater is in a combustion state, and the operation start signal In response to the input, the heating control means controls the heating of the sensing element to the detection temperature by the heating means, and the combustion control signal is output to the combustion control signal output means. And the detection element is heated to the detection temperature, the detection output of the CO detector is stored in the zero point reference value storage means as a new zero point reference value instead of the previous zero point reference value. To perform the initial correction of the zero point reference value,
Thereafter, the output of the combustion control signal by the combustion control signal output means is terminated, and the initial correction means sets the hot water type gas water heater to a combustion state. The combustion state is obtained after the initial correction of the zero point reference value by the initial correction means. When the first combustion of the hot water storage gas water heater is completed and the input of the combustion signal is stopped, the temperature due to the combustion after the completion of the combustion of the hot water storage gas water heater has no influence on the correction of the zero point reference value. At the time of the first combustion, the detection output of the CO detector is stored as a new zero point reference value in the zero point reference value storage means in place of the previous zero point reference value and the zero point reference value is corrected. A CO gas detection device further comprising a correction unit. 3. The heating control means causes the heating means to heat the detection element to the detection temperature in response to the input of the combustion signal, and the heating element detects the detection element when the input of the combustion signal is stopped. 3. The CO gas detector according to claim 2, wherein the heating of the CO gas is terminated. 4. The hot water supply system according to claim 1, wherein said first time correction means has a time keeping means for keeping a fixed time after the input of said combustion signal is stopped. The CO gas detection device according to claim 2 or 3, wherein the correction is performed assuming that the temperature due to combustion after the completion of the combustion of the vessel has no effect on the correction of the zero point reference value. 5. The temperature control device according to claim 1, wherein the first correction unit includes a temperature detection unit configured to detect a temperature of the CO detector based on a resistance value of the detection element after the input of the combustion signal is stopped. 4. The CO gas detection device according to claim 2, wherein the correction is performed when the detected temperature becomes a temperature that does not affect the correction of the zero point reference value. 6. The CO according to claim 2, wherein said operation start signal input means inputs a rise of a power supply voltage of the gas water heater as an operation start signal.
Gas detector. 7. The CO gas detection device according to claim 2, wherein the combustion signal input means inputs a signal generated by a frame rod of the hot water type gas water heater as a combustion signal. . 8. When the detection output of the CO detector for storing the new zero point reference value in the zero point reference value storage means in place of the previous zero point reference value is not within a predetermined range. The CO gas detection device according to claim 1, further comprising an abnormality determination unit that determines that the detection element has an abnormality.