JP3111164B2 - Unburned component concentration detector for combustion equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner provided in a combustion apparatus, which is disposed in contact with combustion gas, and in a state where the ambient temperature is constant, the concentration of a specific unburned component contained in the combustion gas. An unburned component detection sensor that outputs a detection value proportional to, and the detection value changes depending on the ambient temperature even when the unburned component concentration is the same, and in a state where the unburned component concentration is predicted to be a predetermined reference concentration. A reference temperature characteristic represented by a correlation between the detected value of the unburned component detection sensor and the ambient temperature, and the amount of change in the unburned component concentration and the detected value of the unburned component detection sensor when the ambient temperature is constant. A reference characteristic storage means for storing a reference sensitivity indicated by a ratio to a change amount of the temperature, a temperature detection means for detecting an ambient temperature of the unburned component detection sensor, and a reference temperature stored in the reference characteristic storage means. Unburned component concentration detection of a burning appliance provided with a concentration discriminating unit for discriminating the unburned component concentration based on the sensitivity and the reference sensitivity, the detection value of the unburned component detection sensor, and the temperature detected by the temperature detecting unit. Related to the device.

[0002]

2. Description of the Related Art An apparatus for detecting the concentration of unburned components of such a combustion apparatus determines the concentration of a specific unburned component (for example, CO gas) contained in the combustion gas of a burner. In the following description, the specific unburned component to be detected may be abbreviated to the unburned component to be detected, and the concentration of the unburned component to be detected may be simply referred to as the unburned component concentration. The detection value of the unburned component detection sensor is proportional to the unburned component concentration when the ambient temperature is constant, and changes with the ambient temperature even when the unburned component concentration is the same. Therefore, even if the ambient temperature of the unburned component detection sensor changes due to the combustion of the burner, the reference temperature characteristic and the reference sensitivity are stored in advance in the reference characteristic storage means in order to accurately determine the unburned component concentration. The unburned component concentration is determined based on the stored reference temperature characteristics and reference sensitivity, the actual detected value of the unburned component detection sensor, and the detected temperature of the temperature detecting means.

Conventionally, as the reference temperature characteristic and the reference sensitivity, a reference temperature characteristic and a reference sensitivity obtained in accordance with a detection value of an unburned component detection sensor in a state where a burner is not burned are stored in a reference characteristic storage means. I was letting it. That is, without burning the burner, the reference temperature characteristic and the reference sensitivity are obtained in accordance with the detection value of the unburned component detection sensor when the ambient temperature of the unburned component detection sensor is changed by a heater or the like, and these are obtained. It was stored in the reference characteristic storage means.

[0004]

By the way, unburned components to be detected (for example, CO gas) are contained in the combustion gas of the burner.
And other unburned components (for example, H ₂ gas).
In addition, some unburned component sensors also respond to unburned components other than the unburned component to be detected, in which case the detected value of the unburned component sensor is determined by the concentration of the unburned component to be detected. The amount corresponding to the concentration of the unburned component different from the unburned component to be detected is added to the corresponding amount. That is, the detection value of the unburned component sensor is proportional to the concentration of the unburned component to be detected and another unburned component.

However, conventionally, the reference temperature characteristic and the reference sensitivity stored in the reference characteristic storage means are in a state in which the burner is not burned, that is, when only the unburned component to be detected is contained in the atmosphere to be detected. It corresponds to the detection value of the unburned component detection sensor in a state in which another unburned component other than the target unburned component is not included. The detection value of the unburned component detection sensor is a value detected in a state in which the unburned component to be detected and another unburned component other than the unburned component are contained in the atmosphere to be detected. Therefore, when determining the concentration of the unburned component to be detected based on the detection value of the unburned component detection sensor and the reference temperature characteristic and the reference sensitivity stored in the reference characteristic storage means, conventionally, The error of the concentration of the unburned component may increase.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to provide a burner in which the combustion gas contains unburned components other than the unburned components to be detected. An object of the present invention is to make it possible to accurately detect the concentration of an unburned component to be detected.

[0007]

According to the first aspect of the present invention, the reference temperature characteristic and the reference sensitivity stored in the reference characteristic storage means are in a state where the burner is burned, that is, the detection target. It is obtained in accordance with the detection value of the unburned component detection sensor in a state where the unburned component to be detected and another unburned component are contained in the atmosphere. The value detected by the unburned component detection sensor when obtaining the concentration of is detected in a state where the unburned component to be detected and another unburned component other than the unburned component are contained in the atmosphere to be detected. Therefore, even if the unburned component detection sensor also responds to an unburned component other than the unburned component to be detected, unburned components other than the unburned component to be detected are contained in the combustion gas of the burner. Nevertheless, the concentration of the unburned component to be detected can be accurately determined.

Usually, the reference characteristic storage means stores the reference temperature characteristic and the reference sensitivity of the reference unburned component detection sensor as the reference temperature characteristic and the reference sensitivity. On the other hand, there is a variation in the characteristics between the unburned component detection sensors, so that the temperature characteristics and the sensitivity of the unburned component detection sensors actually provided in the combustion equipment and the reference characteristics stored in the reference characteristic storage means are used. In some cases, the difference between the temperature characteristic and the reference sensitivity increases, and in that case, the detection accuracy of the unburned component concentration decreases. The feature configuration described in claim 2 is provided to suppress a decrease in the detection accuracy of the unburned component concentration due to a variation in the characteristics of the unburned component detection sensor.

That is, when the combustion control means performs the combustion control for calibration, the concentration of the unburned component in the combustion gas changes, and accordingly, the unburned component detection means for calibration and the unburned component detection sensor respectively. Output a detection value for the same combustion gas. Then, correction information for correcting the reference temperature characteristic and the reference sensitivity stored in the reference characteristic storage means based on the detection value of the calibration unburned component detection means and the detection value of the unburned component detection sensor. Is determined, and the unburned component concentration is determined in a state where the reference temperature characteristic and the reference sensitivity stored in the reference characteristic storage means are corrected based on the correction information.

For example, when the combustion control for calibration is performed so as to change the excess air ratio while the burner combustion amount is maintained constant, the unburned component concentration is changed while the ambient temperature is maintained substantially constant. Can be. Then, in response to the plurality of states having the same ambient temperature and different unburned component concentrations, the unburned component detecting means for calibration outputs a detected value of the unburned component concentration corresponding to each of the plurality of states, A detection value proportional to the unburned component concentration corresponding to each of the plurality of states is output from the unburned component detection sensor, and the correction information can be obtained based on the detected values.
Further, when the calibration combustion control is executed, even if the ambient temperature also changes, the detection value of the unburned component detection sensor is changed into a plurality of states based on the reference temperature characteristic, in which the ambient temperature is the same and the unburned component concentration is different. Since the correction can be made to the corresponding one, the correction information can be obtained as described above. Here, since the unburned component detection means for calibration is calibrated in advance, the reference temperature characteristic and the reference sensitivity stored in the reference characteristic storage means are transferred to the unburned component detection sensor actually provided in the combustion equipment. It can be corrected to an adapted one. Therefore, it is possible to suppress a decrease in the detection accuracy of the unburned component concentration due to a variation in the characteristics of the unburned component detection sensor, and it is possible to further improve the detection accuracy of the unburned component concentration.

In the normal combustion control, when adjusting the combustion amount of the burner, the excess air ratio is also adjusted to a value appropriate for each combustion amount. Therefore, when the burner combustion amount differs, the concentration of hydrogen gas, which is another unburned component different from the unburned component to be detected, also differs.

According to the third aspect of the present invention, the correction information corresponding to each of the different amounts of combustion is obtained according to the amount of combustion which is adjusted along with the execution of the normal combustion control.
Then, based on the correction information obtained in correspondence with each of the different combustion amounts according to the change in the combustion amount,
The unburned component concentration is determined in a state where the reference temperature characteristic and the reference sensitivity stored in the reference characteristic storage unit have been corrected.
Therefore, the detection accuracy of the unburned component concentration can be further improved despite the change in the burner combustion amount.

According to the fourth aspect of the present invention, the correction information corresponding to each of the different combustion amounts according to a change in the combustion amount adjusted with the execution of the normal combustion control, the calibration combustion control. Is obtained based on the correction information corresponding to the set combustion amount for calibration obtained with the execution of and the correction calculation information stored in advance in accordance with each of the different combustion amounts. Incidentally, when obtaining the correction information corresponding to each of the different combustion amounts, it is assumed that the calibration combustion control is executed for each of the different combustion amounts, and the correction information is obtained with the execution of each calibration combustion control. Is done. However, in this case, the combustion control for calibration needs to be performed with a plurality of different combustion amounts, and thus the control configuration becomes complicated. On the other hand, according to the characteristic configuration of the fourth aspect, the combustion control for calibration need only be executed once with the set combustion amount for calibration, so that the control configuration can be simplified. became.

There are various types of fuel supplied to the burner, but the content of hydrogen gas differs for each type of fuel. Therefore, when the fuel supplied to the burner differs, the concentration of hydrogen gas in the combustion gas also varies, and as a result, the sensitivity of the unburned component detection sensor also varies. According to the characteristic configuration of claim 5, when the fuel type is changed to a fuel type different from the fuel type stored in the reference characteristic storage means in accordance with the reference sensitivity, the fuel product reference characteristic storage means The stored reference sensitivity is corrected to one corresponding to the changed fuel type based on the fuel type change correction information. Therefore, the detection accuracy of the unburned component concentration can be further improved regardless of the type of fuel supplied to the burner.

According to a sixth aspect of the present invention, the unburned component detecting means for calibration is disposed in contact with the combustion gas of the burner, and detects the concentration of the unburned component contained in the combustion gas. A corresponding detected value is output, and the calibration unburned component detection sensor is calibrated in advance so that the temperature characteristic and sensitivity are the same or substantially the same as the reference temperature characteristic and reference sensitivity stored in the storage means. It is configured. Therefore, since it is not necessary to provide a large-scale device such as a gas analyzer as the unburned component detection means for calibration, the configuration of the device can be simplified.

According to the seventh aspect of the present invention, when the correction information obtained by the correction information detecting means is out of the proper range, the notifying means is activated. In other words, when the temperature characteristics and the sensitivity of the unburned component detection sensor actually provided in the combustion equipment are significantly different from the reference temperature characteristics and the reference sensitivity stored in the reference characteristic storage means, respectively, Since it is considered that there is some problem in the detection sensor, in such a case, it is possible to take measures such as repairing or replacing the unburned component detection sensor by operating the notification means.

According to the eighth aspect of the present invention, each storage means is constituted by a non-volatile storage element, so that the storage means retains the stored information even in the case of no power supply such as a power failure. Therefore, even thereafter, the concentration of the unburned component can be accurately determined.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a hot water supply device as an example of a combustion device provided with an unburned component concentration detection device. The hot water supply device includes a water heater Y, a control unit H for controlling the operation of the water heater Y, and a remote control device. R. or,
In order to calibrate the unburned component concentration detection device, a calibration unburned component detection means M is provided in the water heater Y so as to be detachable, and a calibration remote control device Rc is provided.

The water heater Y includes a combustion chamber 1, a burner 2 provided inside the combustion chamber 1, and a heat exchanger 3 for heating water.
An exhaust path 5 connected to the upper part of the combustion chamber 1 for discharging combustion gas from the burner 2 to the outside of the chamber; supplying combustion air to the burner 2 and discharging the combustion gas from the burner 2 to the outside through the exhaust path 5 A fan 4 for discharging, a water supply path 6 for supplying water for heating to the heat exchanger 3, a water supply path 7 for supplying hot water heated in the heat exchanger 3 to a hot water tap (not shown), and a burner 2 And a fuel supply path 8 for supplying fuel (gas) to the fuel cell. The burner 2 is composed of two unit burners 2
A, 2B, and the fuel supply path 8 is a unit burner 2
A is branched into a branch path 8A connected to A and a branch path 8B connected to the unit burner 2B.

An igniter 18 for igniting the burner 2 and a frame rod 19 for detecting ignition are provided near the burner 2. The water supply passage 6 is provided with a water supply amount sensor 9 for detecting a water supply amount Qi to the heat exchanger 3, and the hot water supply passage 7 is provided with a hot water supply temperature sensor 10 for detecting a hot water supply temperature Tx for a hot water tap. .

The fuel supply passage 8 is connected to a general household gas supply pipe. The fuel supply passage 8 is provided with an on-off valve 20 for interrupting the supply of fuel to the burner 2 and the branch passage 8A. On-off valve 12 for intermittently supplying fuel to unit burner 2A
A, an electromagnetic proportional valve 11A for adjusting the fuel supply amount, and an on-off valve 12B for interrupting the supply of fuel to the unit burner 2B in the branch 8B, and an electromagnetic proportional valve 11B for adjusting the fuel supply amount. Is provided. That is, the on-off valve 12A
Is opened, the on-off valve 12B is closed, and the electromagnetic proportional valve 11A is adjusted, so that only the unit burner 2A is burned, and the input Ip to the burner 2 (ie,
(Burner 2 combustion amount) is adjusted. When the on-off valves 12A and 12B are opened, the electromagnetic proportional valves 11A and 11B are opened.
Is adjusted, the input Ip to the burner 2 is adjusted in a state where the unit burners 2A and 2B are burned. Therefore, the electromagnetic proportional valves 11A and 11B and the on-off valves 12A and 12B constitute a combustion amount adjusting means capable of adjusting the combustion amount of the burner 2.

The fan 4 is capable of adjusting the amount of air flow by adjusting the number of revolutions thereof. The fan 4 supplies air for combustion to the burner 2 and constitutes air supply means capable of adjusting the supply amount. .

The remote control device R is connected to the control section H by wire or wirelessly, and has an operation switch 13 for instructing operation and stop of the hot water supply device, a temperature setting switch 14 for setting a set target hot water supply temperature Tp, and various information. Are provided. In addition, the display lamp 15 is configured to display whether or not the hot water supply device is operating, and the display lamps 16 and 17 are configured to display an abnormal state as described later.

The exhaust passage 5 is provided with a contact combustion type CO sensor S as an example of an unburned component detection sensor in a state of contacting the combustion gas of the burner 2. This CO sensor S
Is configured to output a detection value (hereinafter, referred to as an output value Vs) corresponding to the concentration D of carbon monoxide (CO) as a specific unburned component contained in the combustion gas.

FIG. 2 shows the configuration of the CO sensor S. CO sensor S is a stainless steel protective frame 2
1, the sensor element 23, the temperature compensation reference element 24, and the ambient temperature t of the CO sensor S
Is provided with a temperature sensor 25 for detecting the temperature. The sensor element 23 and the temperature-compensating reference element 24 are each composed of a platinum wire carrying a catalyst.
3, the temperature-compensating reference element 24 and the resistance elements 26 and 27 are connected in a bridge circuit state as shown in FIG. The sensor element 23 and the temperature-compensating reference element 24 are heated to about 200 ° C. as a set temperature for detection by the flow of an electric current, and the unburned components that come into contact with their surfaces are burned by a catalytic action. At this time, since the catalyst carried on the sensor element 23 has selectivity for CO, a difference occurs between the element temperatures of the sensor element 23 and the temperature compensation reference element 24. Since the resistance value of the platinum wire changes depending on the temperature, C
As the O concentration increases, the difference between the resistance values of the sensor element 23 and the temperature compensation reference element 24 increases. Therefore,
An output value Vs according to the CO concentration in the combustion gas is output from the connection between the sensor element 23 and the temperature compensation reference element 24 and the connection between the resistance elements 26 and 27 in the bridge circuit. (Volts). Note that reference numeral 28 in FIG. 2 denotes a connector portion for connecting a lead wire connected to the control portion H.

The output value Vs of the CO sensor S changes depending on the ambient temperature t even when the CO concentration is the same, and exhibits a characteristic that varies in proportion to the CO concentration D when the ambient temperature t is constant. When the ambient temperature t is constant, the output value Vs and the CO concentration D of the CO sensor S are represented by the ratio between the variation of the CO concentration D and the variation of the output value Vs when the ambient temperature t is constant. The sensitivity α has, for example, a correlation represented by the following (Formula 1). Vs = αD + Vo (Equation 1) Here, Vo is the output value Vs of the CO sensor S when the CO concentration D is zero, and is particularly referred to as a zero point output value to distinguish it from the others. The solid line in FIG. 4 indicates the zero point output value Vo.
And temperature characteristics indicated by a correlation between the temperature and the ambient temperature t. The output value Vs of the CO sensor S changes in a state where the correlation between the output value Vs indicated by the solid line in FIG. 4 and the ambient temperature t moves in a parallel direction in which the output value increases as the CO concentration D increases. I do. Therefore, between the output value Vs, the zero point output value Vo corresponding to the ambient temperature t of the CO sensor S when the output value Vs is output, the CO concentration D, and the sensitivity α, the following (Equation 2) There is a correlation represented by. An example of the correlation is shown in FIG. D = (Vs−Vo) × (1 / α) (2)

The controller H includes a remote controller R, a fan 4, a water supply amount sensor 9, a hot water supply temperature sensor 10, an electromagnetic proportional valve 1
1A, 11B, intermittent valves 12A, 12B, 20, an igniter 18, a frame rod 19, a CO sensor S, and a temperature sensor 25 are connected. The control unit H includes a microcomputer, and as shown in FIG.
The combustion control means 101 for controlling the combustion operation of the fan 4 and the operation of the fan 4, the sensor control means 102 for controlling the energization to the CO sensor, and the zero point output value Vo and the ambient temperature t in the CO sensor S as a reference. A reference characteristic storage unit 103 for storing a reference temperature characteristic indicated by a correlation and a reference sensitivity α of the CO sensor S serving as a reference; a reference temperature characteristic and a reference sensitivity α stored in the reference characteristic storage unit 103; , A concentration determining means 104 for determining the CO concentration D based on the output value Vs of the CO sensor S and the detected temperature t of the temperature sensor 25. Each of the incomplete combustion determining means 105 for determining the combustion state is provided.

When the water supply amount Qi adjusted by the hot water tap and detected by the water supply amount sensor 9 reaches the set water amount, the combustion control means 101 executes the ignition control of the burner 2, and the hot water temperature Tx becomes the set target hot water temperature Tp. In addition to adjusting the input Ip of the burner 2, the rotation speed of the fan 4 is controlled so that the rotation speed of the fan 4 becomes a target rotation speed preset for the input Ip, and the water supply amount Qi is set. When the amount of water is less than the amount of water, the burner 2 is configured to stop burning.

As the reference temperature characteristic and the reference sensitivity α, the reference temperature characteristic and the reference sensitivity α obtained corresponding to the output value Vs of the CO sensor S in a state where the burner 2 is burned are stored in the reference characteristic storage means 103. It is remembered.

In the following, the reference temperature characteristic and the reference sensitivity α are
A method of obtaining the output value Vs of the CO sensor S in a state where the burner 2 is burned will be described. C
A gas analyzer (not shown) in which the O concentration D is output as an absolute value and which is calibrated in advance is arranged so as to measure the CO concentration D in the exhaust path 5 provided with the CO sensor S. . Then, the combustion control means 101 switches the state in which the burner 2 is burned at an appropriate excess air ratio while maintaining the predetermined input Ip, to the state in which the burner 2 is burned at an inappropriate excess air ratio smaller than the appropriate value. Control. It should be noted that when the burner 2 is burned at an appropriate excess air rate and when it is burned at an inappropriate excess air rate, C
The difference in the ambient temperature t of the O sensor S is so small as to be negligible, and when the burner 2 is burned at an inappropriate excess air ratio, the CO concentration D in the combustion gas increases. And
The output value Vs of the CO sensor S and the detection value D of the analyzer when the burner 2 is burned at an appropriate excess air ratio, and the output of the CO sensor S when the burner 2 is burned at an inappropriate excess air ratio. Based on the value Vs and the detection value D of the analyzer, the sensitivity α and the zero point output value Vo are obtained by the above (Equation 1). The obtained sensitivity α is stored in the reference characteristic storage unit 103 as the reference sensitivity α. Further, by executing the above control with a plurality of inputs Ip different from each other,
By changing the atmosphere temperature t of the CO sensor S to a plurality of values, zero point output values Vo corresponding to the respective atmosphere temperatures t are obtained, and a correlation between the thus obtained atmosphere temperature t and the zero point output value Vo is calculated. As a reference temperature characteristic, a reference characteristic storage means 1
03 is stored. The reference temperature characteristic obtained as described above is shown by a solid line in FIG. 4, and FIG. 5 shows (Expression 2) based on the reference sensitivity α obtained as described above. In the following description, the reference temperature characteristic stored in the reference characteristic storage means 103 is indicated by Vo = S (t), as indicated by the solid line in FIG.

Incidentally, the temperature characteristics and sensitivity of the CO sensor S actually provided in the apparatus may differ from the reference temperature characteristics and the reference sensitivity α stored in the storage means 103. It is necessary to calibrate the stored reference temperature characteristic and reference sensitivity α so as to match the temperature characteristic and sensitivity of the CO sensor S actually provided in the apparatus. Next, a device configuration for calibrating the unburned component concentration detecting device of the hot water supply device configured as described above will be described. As shown in FIG. 1, the unburned component detecting means for calibration M
Is disposed in the exhaust path 5 of the water heater Y in contact with the combustion gas of the burner 2, outputs an output value Vc corresponding to the CO concentration D in the combustion gas, and has sensitivity and temperature characteristics. The calibration C as a calibration unburned component detection sensor which has been calibrated in advance to be the same or substantially the same as the reference temperature characteristic and the reference sensitivity α stored in the reference characteristic storage means 103.
It is composed of an O sensor Sc. The calibration CO sensor Sc is not provided with a sensor corresponding to the temperature sensor 25 provided in the CO sensor S.
The configuration is the same as that of the sensor S. Calibration CO sensor S
c is connected to the control unit H by a lead wire 37,
The energization is controlled by the sensor control means 102 and the output value Vc is input to the control unit H.

The calibration remote controller Rc is connected to the control unit H by wire or wirelessly, and a calibration command switch 31 for instructing the control unit H to execute calibration control, and a display lamp for displaying various information as described later. 33, 34, 35, etc. are provided.

Next, a control unit H for executing the calibration control
Will be described. Combustion control means 101
Are the electromagnetic proportional valves 11A, 11B, the on-off valves 12A, 12
B and the fan 4 are set in advance to change the CO concentration D in addition to the normal combustion control for adjusting the combustion amount (that is, the input Ip) of the burner 2 in a state where the excess air ratio is appropriately maintained. From the state in which the burner 2 is burned at an appropriate excess air rate while maintaining the set input Ip for calibration (for example, the maximum input), the state in which the burner 2 is burned at an inappropriate excess air rate smaller than the appropriate value. It is configured to execute a calibration combustion control for controlling the switching. Further, after executing the combustion control for calibration, the combustion control means 101 stops the combustion of the burner 2, and subsequently,
Fan 4 only for the set time for post-purging (for example, 5 minutes)
It is configured to execute a post-purge for performing ventilation by the air purifier.

Further, the control unit H stores the reference characteristic storage means 103 based on the output value Vs of the CO sensor S and the output value Vc of the calibration CO sensor Sc, which are detected during execution of the combustion control for calibration. The correction information detecting means 106 for obtaining correction information for correcting the reference temperature characteristic and the reference sensitivity α stored in the reference characteristic storage means 103 is used as a reference in the reference characteristic storage means 103. A fuel type information storage means 107 is provided for storing fuel type change correction information for correcting a fuel type different from the fuel type stored in accordance with the sensitivity α in accordance with the fuel type. I have.

The density determining means 104 corrects the reference temperature characteristic and the reference sensitivity α stored in the reference characteristic storage means 103 based on the correction information obtained by the correction information detecting means 106, It is configured to determine the density D.

A fuel type setting switch 36 as fuel type setting means for setting a fuel type is provided in a casing (not shown) of the water heater Y. The reference characteristic storage means 103 stores the fuel type set by the fuel type setting switch 36 at the time of executing the calibration combustion control, and stores the fuel type into the calibration setting input Ip with the execution of the calibration combustion control. Based on the correction information obtained correspondingly, the correction calculation information for obtaining the correction information corresponding to each of the different inputs Ip is different according to the input Ip adjusted along with the execution of the normal combustion control. It is stored according to each input Ip.

Further, the correction information detecting means 106 is configured to obtain the correction information corresponding to each of the different inputs Ip in accordance with the input Ip adjusted along with the execution of the normal combustion control. Is a reference temperature characteristic and a reference sensitivity α stored in the reference characteristic storage means 103 based on the correction information obtained by the correction information detecting means 106 in correspondence with each of the different inputs Ip according to the change of the input Ip. Is configured so that the CO concentration D is determined in a state where is corrected.

Further, when the fuel type set by the fuel type setting switch 36 is different from the fuel type stored in the reference characteristic storage means 103, the correction information detection means 106 stores the fuel type in the fuel type information storage means 107. Based on the fuel type change correction information, the reference characteristic storage means 10
3 is corrected, and the reference sensitivity α stored in the reference characteristic storage unit 103 is rewritten to a corrected value.

Next, a method for obtaining the correction information by the correction information detecting means 106 will be described. Since the combustion control for calibration executed to obtain the correction information is executed by the calibration setting input Ip, the ambient temperature t is known in advance and is set as the calibration setting temperature ts. . When the burner 2 is burned at an appropriate excess air ratio and when the burner 2 is burned at an inappropriate excess air ratio, which is detected during execution of the combustion control for calibration. From the output value Vc, the reference temperature characteristic and the reference sensitivity α stored in the reference characteristic storage means 103, and the calibration set temperature ts, the burner 2 is set to the appropriate excess air ratio by the above (Equation 2). , And when the burner 2 is burned at an inappropriate excess air ratio, the respective CO concentrations D are determined. Further, the output value Vs and the CO concentration D of the CO sensor S when the burner 2 is burned at an appropriate excess air ratio, and the output of the CO sensor S when the burner 2 is burned at an inappropriate excess air ratio. Values Vs and C
Based on the O concentration D, the sensitivity α and the zero point output value Vo are calculated by (Equation 1).

Then, the obtained sensitivity α is used as sensitivity correction information, and the reference sensitivity α stored in the reference characteristic storage means 103 is rewritten to the obtained sensitivity α. Also, a deviation (= S (ts) between the calculated zero point output value Vo and a reference zero point output value S (ts) corresponding to the calibration set temperature ts in the reference temperature characteristic stored in the reference characteristic storage means 103. ) -V
o) is obtained as a correction deviation ΔVf, and the correction deviation Δ
Vf as temperature characteristic correction information,
Store it in 3. Therefore, the corrected temperature characteristic Rf (t) corrected based on the temperature characteristic correction information is obtained by changing the reference temperature characteristic S (t) by the correction deviation ΔVf as shown by the broken line in FIG.
And Rf (t) = S (t) −ΔVf.

The ratio between the correction deviation ΔVf for the calibration setting input Ip and the correction deviation ΔVf for the input Ip different from the calibration setting input Ip is known in advance. Stores the ratio as the correction calculation information for the reference temperature characteristic according to each of the different inputs Ip. Therefore, the correction information detecting means 106 calculates the correction deviation ΔV
By multiplying f by the ratio stored in the reference characteristic storage means 103, a correction deviation ΔVf is obtained for each of the different inputs Ip, and these are stored in the reference characteristic storage means 103 in correspondence with the respective inputs Ip. Let it.
For example, as shown in FIG. 6, the correction deviation ΔVf is obtained according to each of the different inputs Ip.

The ratio between the reference sensitivity α for the calibration setting input Ip and the reference sensitivity α for the input Ip different from the calibration setting input Ip is known in advance. Stores the ratio as the correction calculation information for the reference sensitivity according to each of the different inputs Ip. Therefore, the correction information detecting means 106 stores the obtained sensitivity α in the reference characteristic storing means 10.
By multiplying the ratio stored in 3 by the above-mentioned ratio, a reference sensitivity α is obtained for each of the different inputs Ip, and these are stored in the reference characteristic storage means 103 in correspondence with each of the inputs Ip.

If the obtained correction deviation ΔVf is out of the proper range, the correction information detecting means 106 turns on the display lamp 33 to notify an error. The appropriate range for correcting the reference temperature characteristic is set to, for example, a range indicated by hatching in FIG. If the obtained sensitivity α is out of the appropriate range, the correction information detecting means 106 turns on the display lamp 34 to notify an error. The appropriate range for correcting the reference sensitivity α is set to, for example, a range indicated by hatching in FIG.

Incidentally, the characteristics of the CO sensor S change with time.
It exhibits the behavior that o changes. Thus, the correction information detecting means 106 is configured to obtain the deterioration determination deviation ΔVo as follows. That is, after post-purge is executed following the combustion control for calibration, the output value Vs of the CO sensor S (the value when the CO concentration D is zero) and the reference zero point output corresponding to the ambient temperature t1 at that time are obtained. The value S (t
The deviation ΔVn (= S (t1) −Vs) from 1) is obtained, and the deviation ΔVn is stored in the reference characteristic storage means 103. Based on the deviation ΔVn, the temperature characteristic Rn (t) for deterioration determination is obtained. Is set as Rn (t) = S (t) −ΔVn. The degradation determination temperature characteristic Rn (t) is obtained by translating the reference temperature characteristic S (t) by the deviation ΔVn, as indicated by the one-dot chain line in FIG. Then, in the normal hot water supply mode control described later, the C
The output value Vs of the O sensor S and the zero point output value Rn in the temperature characteristic for deterioration determination corresponding to the ambient temperature t2 at that time
A deviation from (t2) (= Rn (t2) -Vs) is obtained as a deterioration determination deviation ΔVo, and stored in the reference characteristic storage unit 103.

If the obtained deterioration judgment deviation ΔVo is out of the appropriate range, the correction information detecting means 106
Is turned on to notify that maintenance such as replacement or repair of the CO sensor S is required.

The fuel type information storage means 107 stores the fuel product
The reference sensitivity α according to the fuel type is used as the type change correction information.
Is stored in association with the fuel type. Therefore,
The positive information detecting means 106 controls the fuel type setting switch 36
The set fuel type is stored in the reference characteristic storage means 103.
If the fuel type is different from the
The fuel type set by the fuel type setting switch 36
Sensitivity corresponding to_rIs obtained in the reference characteristic storage means 103.
Sensitivity α obtained from stored reference sensitivity α_rWrite to the value of
Change. It is stored in the reference characteristic storage means 103.
Stored in the fuel type information storage means 107 corresponding to the fuel type
Is the reference sensitivity ₁And the fuel type setting switch
Record fuel type information corresponding to the fuel type set in 36
The reference sensitivity stored in the storage means 107 is α_TwoAnd α_r= Α × (α_Two/ Α₁)

Next, a method of determining the CO concentration D by the concentration determining means 104 will be described. Density determination means 1
Reference numeral 04 reads the correction deviation ΔVf and the reference sensitivity α corresponding to the input Ip adjusted with the execution of the normal combustion control from the reference characteristic storage means 103, and corrects the temperature characteristic based on the read correction deviation ΔVf. A zero point output value Rf (t3) corresponding to the detected temperature t3 of the temperature sensor 25 in Rf (t) is obtained, and the zero point output value Rf (t) is obtained.
3) Based on the output value Vs of the CO sensor S, the read reference sensitivity α, and the deterioration determination deviation ΔVo stored in the reference characteristic storage unit 103, the CO concentration is calculated based on the following (Equation 3). Calculate D. D = {Vs−Rf (t3) + ΔVo} × (1 / α) (3)

When the state in which the CO concentration D calculated by the concentration determining means 104 is equal to or higher than the set concentration (for example, 1000 ppm) continues for a set time (for example, 20 seconds), the incomplete combustion determining means 105 detects incomplete combustion. It is determined that the fuel is in a combustion state, and the display lamp 16 is turned on to notify that the fuel is in an incomplete combustion state. Immediately after the start of combustion of the burner 2, a transient incomplete combustion state occurs in the combustion of the burner 2 and the CO concentration D temporarily becomes extremely high. In order not to make a determination, the incomplete combustion determination operation is not performed while a set time (for example, 60 seconds) has elapsed after the start of combustion.

The reference characteristic storage means 103 and the fuel type information storage means 107 are constituted by, for example, an EEPROM (electrically erasable non-volatile memory) or the like. Provided in the form.

Hereinafter, the control operation in the control unit H will be described with reference to FIG.
This will be described based on the flowchart shown in FIG. At step # 1, it is determined whether or not the calibration mode is commanded by the calibration command switch 31 of the calibration remote controller Rc. When the calibration mode is commanded, the calibration mode control is executed, and the calibration mode is set. If not, in step # 2, the fuel type setting switch 36
By determining whether a fuel type different from the fuel type stored in the reference characteristic storage means 103 has been set, it is determined whether a fuel type change has been commanded. Executes fuel type change control,
When the fuel type change is not instructed, normal hot water supply mode control is executed.

First, the calibration mode control will be described with reference to the flowcharts shown in FIGS. When the apparatus power switch is ON and the start of combustion is instructed based on the fact that the hot water supply is started and the water supply amount Qi detected by the water supply amount sensor 9 exceeds the set water amount (steps # 31 and # 32). ), The fuel type set by the fuel type setting switch 36 is stored in the reference characteristic storage means 103, and the power of the CO sensor S and the calibration CO sensor Sc is turned off.
N and set each element temperature to the set temperature for detection (about 200 °
Set to C). (Steps # 33 and # 34). Subsequently, the ignition control of the burner 2 is executed (step # 3).
5). That is, the on-off valve 20 and the on-off valves 12A, 12B
Is opened to supply the fuel gas to the burner 2, and the ignition by the igniter 18 is performed. Subsequently, when ignition is confirmed by the frame rod 19 (step # 36), the ignition control is stopped, and normal combustion control is executed with the maximum input Ip (step # 37).

Subsequently, the timer is started and waits until the atmosphere stabilizes. When the timer expires, the output value Vs of the CO sensor S and the calibration CO sensor S
The output value Vc of step c is read (steps # 33 to # 4).
0). Subsequently, by reducing the rotation speed of the fan 4 to make the excess air ratio smaller than the appropriate value, the combustion control for calibration is executed, and the output value Vs of the CO sensor S and the calibration CO
The output value Vc of the sensor Sc is read (steps # 41 and # 42). Then, as described above, the sensitivity α and the correction deviation ΔVf corresponding to the setting input IP for calibration are obtained, and it is determined whether or not each is within the appropriate range. Is rewritten to the obtained sensitivity α, and the obtained correction deviation ΔVf is stored in the reference characteristic storage means 103. If it is out of the appropriate range, the display lamp 33 or 34 is turned on to notify an error (steps # 43 to # 43).
# 47).

Subsequently, the correction deviation ΔVf corresponding to the calibration setting input IP and the reference characteristic storage means 103
Is calculated based on the correction calculation information stored in the input characteristic Ip, and the correction deviation ΔVf is determined for each of the different inputs Ip, and is stored in the reference characteristic storage means 103 in correspondence with the input Ip (step # 48). A reference sensitivity α corresponding to the calibration setting input IP; and
Based on the correction calculation information stored in the reference characteristic storage unit 103, the reference sensitivities α are obtained for the different inputs Ip, and are stored in the reference characteristic storage unit 103 in association with the inputs Ip (step #). 49).

Subsequently, the combustion stop control is executed, and then the post purge is executed (steps # 50 and # 5).
1).

It is determined that the CO concentration D is zero by determining that the detected temperature t of the temperature sensor 25 is 40 ° C. or less (step # 52), and the detected temperature t of the temperature sensor 25 is 40 ° C. When the value becomes below, the output value Vs of the CO sensor S is read, the deviation ΔVn is obtained as described above, and the obtained deviation ΔVn is stored in the reference characteristic storage means 103 (steps # 53 and # 54). . continue,
The display lamp 35 is turned on to notify that the calibration is completed, the power of the CO sensor S and the calibration CO sensor Sc is turned off, and the calibration mode control is completed (step # 55).
And # 56).

When the display lamp 33 or 34 is turned on, the operator resets the apparatus by turning the apparatus power switch OFF / ON, etc., repairs the CO sensor S or replaces it with a new one, and then performs the calibration mode control again. Is executed.

Next, normal hot water supply mode control for controlling the hot water supply device will be described with reference to flowcharts shown in FIGS. When the calibration mode is not commanded in step # 1 and the fuel type change is not commanded in step # 2, the hot water supply is started and the water supply amount Qi detected by the water supply amount sensor 9 exceeds the set water amount. When the start is instructed (step # 3), the power of the CO sensor S is turned on to set the element temperature to the detection set temperature (step # 4), and subsequently, the ignition control of the burner 2 is executed (step # 4). Step # 5).

When ignition is confirmed by the frame rod 19 (step # 6), the ignition control is stopped and
The normal combustion control is executed (Step # 7). In other words, the opening and closing valves 12A, 12B,
Further, the fuel supply amount Ip of the burner 2 is adjusted by adjusting and controlling the electromagnetic proportional valves 11A and 11B, and the fan 4 is controlled so that the rotation speed of the fan 4 becomes a target rotation speed set in advance with respect to the input Ip. To control the number of revolutions.

Subsequently, the correction deviation ΔVf and the reference sensitivity α corresponding to the input Ip are obtained from the reference characteristic storage means 103.
Is read, the output value Vs of the CO sensor S and the detected temperature t of the temperature sensor 25 are read, and the CO concentration D is calculated as described above (steps # 8 to # 10). Subsequently, it is determined whether or not the combustion state is incomplete (step #).
11) If not incomplete combustion, in step # 12, until the hot water tap is closed and the water supply amount Qi detected by the water supply amount sensor 9 falls below the set water amount, the combustion stop command is instructed until the command is issued. The control of # 7 to # 12 is repeated. When a combustion stop command is issued in step # 12, the combustion stop control is executed, and then post-purge is executed (steps # 13 and # 14).

It is determined that the CO concentration D is zero by determining that the detected temperature t of the temperature sensor 25 is 40 ° C. or less (step # 15), and the detected temperature t of the temperature sensor 25 is 40 ° C. When the value falls below, the output value Vs of the CO sensor S and the detected temperature t of the temperature sensor 25 are read, and the deterioration determination deviation ΔVo is calculated as described above, and whether or not the calculated deviation ΔVo is within the appropriate range is determined. Is determined, and when it is within the appropriate range, the deterioration determining deviation ΔVo stored in the storage means 103 is rewritten to the calculated deterioration determining deviation ΔVo, and when it is out of the appropriate range, the display lamp 17 is turned on. Then, the maintenance of the CO sensor S is notified (steps # 16 to # 20).

Subsequently, the power supply of the CO sensor S is turned off (step # 21), and the apparatus enters a state of waiting for a combustion start command.

When the start of combustion is not commanded in step # 3 and the power switch of the apparatus is turned off, the control is terminated (step # 22). When ignition is not confirmed in step # 6, or when incomplete combustion is determined in step # 11, the on-off valve 20 and the on-off valves 12A and 12B are closed to stop the combustion of the burner 2. The burner 2 is turned on until the display lamp 16 is turned on to indicate an abnormality, and the power of the CO sensor S is turned off, and the reset operation such as turning off / on the power switch of the apparatus is performed. Is prohibited (steps # 23 to # 26).

Next, the fuel type change control will be described with reference to the flowchart shown in FIG. . In step # 2, when the fuel type change command is issued by the fuel type setting switch 36, the fuel type change control is executed as described below. That is, from the fuel type information storage means 107, the reference sensitivity α ₂ corresponding to the fuel type set by the fuel type setting switch 36, and the reference information storage means 10
3 reads the reference sensitivity alpha ₁ corresponding to the fuel varieties stored (step # 61), followed by reading the reference sensitivity alpha stored in the reference information storage unit 103 (step # 62), on the basis of their As described above, the sensitivity α _r corresponding to the fuel type set by the fuel type setting switch 36 is determined, and the corrected reference sensitivity α _r obtained by determining the reference sensitivity α stored in the reference information storage unit 103 is obtained. Rewrite (step # 63). Subsequently, the reference information storage means 10
3 is rewritten to the fuel type set by the fuel type setting switch 36 (step #).
64).

[Another Embodiment] Hereinafter, another embodiment will be described. (A) In the above embodiment, the case where the reference temperature characteristic and the reference sensitivity α stored in the reference characteristic storage unit 103 are corrected in accordance with the input Ip adjusted in accordance with the execution of the normal combustion control has been exemplified. But instead,
One of the reference temperature characteristic and the reference sensitivity α stored in the reference characteristic storage unit 103 may be corrected.
Alternatively, the correction of the reference temperature characteristic and the reference sensitivity α stored in the reference characteristic storage unit 103 according to the input Ip adjusted with the execution of the normal combustion control may not be performed.

(B) As a specific configuration of the calibration unburned component detection means M, various configurations can be applied other than the calibration CO sensor Sc exemplified in the above embodiment. For example, a gas analyzer configured to output the CO concentration D as an absolute value can be applied. Further, in the above-described embodiment, the reference temperature characteristic and the reference sensitivity α are determined by changing the output value V of the CO sensor
Although the case where the gas analyzer is used when obtaining the value corresponding to s is illustrated, a calibration CO sensor Sc may be used instead.

(C) When obtaining the correction deviation ΔVf and the reference sensitivity α corresponding to each of the different inputs IP, the calibration combustion control is executed by each of the different inputs IP other than the calibration setting input IP, and each calibration IP is obtained. With execution of the combustion control, the correction deviation ΔVf and the reference sensitivity α may be obtained.

(D) In the above embodiment, the case where the reference sensitivity α is corrected in accordance with the fuel type has been described as an example. In addition, the reference temperature characteristics may be corrected.

(E) In the above embodiment, the reference temperature characteristic is exemplified by the case where the output value Vs and the ambient temperature t in the state where the CO concentration D is predicted to be zero are correlated. Alternatively, the correlation between the output value Vs and the ambient temperature t in a state where the predetermined reference concentration is predicted when the CO concentration D is not zero may be used.

(F) In the above embodiment, the case where the CO sensor S is applied as an example of the unburned component detection sensor has been described. However, as the unburned component detection sensor, for example, oxygen may be used. An oxygen sensor for detecting and a hydrogen sensor for detecting hydrogen can be applied.

(G) Instead of the configuration in which various kinds of information are turned on by the lamps as in the above embodiment, various types of notification methods such as a configuration in which a buzzer is used or a configuration in which a lamp and a buzzer are used together are used. Can be used.

(H) The present invention is not limited to the hot water supply apparatus, but can be applied to other combustion equipment such as a fan heater.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall configuration of a water heater.

FIG. 2 is a sectional view of a CO sensor.

FIG. 3 is a circuit configuration diagram of a CO sensor.

FIG. 4 is a diagram showing temperature characteristics of a CO sensor.

FIG. 5 is a diagram showing a correlation between an output value of a CO sensor and a CO concentration.

FIG. 6 is a diagram showing a relationship between an input and a deviation for correction.

FIG. 7 shows a flowchart of a control operation.

FIG. 8 shows a flowchart of a control operation.

FIG. 9 is a diagram showing a flowchart of a control operation.

FIG. 10 is a diagram showing a flowchart of a control operation.

FIG. 11 is a diagram showing a flowchart of a control operation.

[Explanation of symbols]

2 Burner 4 Air supply means 11A, 11B, 12A, 12B Combustion amount adjustment means 25 Temperature detection means 33, 34 Notification means 36 Fuel type setting means 101 Combustion control means 103 Reference characteristic storage means 104 Concentration determination means 106 Correction information detection means 107 Fuel type information storage means M Unburned component detection means for calibration S Unburned component detection sensor Sc Unburned component detection sensor for calibration

Continuation of the front page (56) References JP-A-9-23658 (JP, A) JP-A-9-236258 (JP, A) JP-A-9-264534 (JP, A) JP-A-8-12881 (JP, A) JP-A-8-121754 (JP, A) JP-A-4-115244 (JP, A) JP-A-6-265518 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) F23N 5/24 107 F23N 5/00

Claims (8)

(57) [Claims] A burner provided in a combustion apparatus is disposed in contact with combustion gas, and when the ambient temperature is constant, a detected value proportional to the concentration of a specific unburned component contained in the combustion gas is detected. An unburned component detection sensor that outputs and changes the detection value according to the ambient temperature even when the unburned component concentration is the same, and the unburned component detection sensor in a state where the unburned component concentration is predicted to be a predetermined reference concentration A reference temperature characteristic indicated by a correlation between the detected value of the ambient temperature and the ambient temperature, and the ratio of the variation of the unburned component concentration to the variation of the detected value of the unburned component detection sensor when the ambient temperature is constant. A reference characteristic storage unit that stores a reference sensitivity represented by: a temperature detection unit that detects an ambient temperature of the unburned component detection sensor; a reference temperature characteristic and a reference sensitivity stored in the reference characteristic storage unit; An unburned component concentration detection device for a combustion appliance provided with a concentration determination unit that determines an unburned component concentration based on a detection value of the unburned component detection sensor and a temperature detected by the temperature detection unit, As the reference temperature characteristic and the reference sensitivity, a reference temperature characteristic and a reference sensitivity obtained in accordance with a detection value of the unburned component detection sensor in a state where the burner is burned are stored in the reference characteristic storage means. Unburned component concentration detector for combustion equipment. 2. A method for detecting the concentration of the specific unburned component contained in the combustion gas of the burner, and for calibrating the unburned component detection means calibrated in advance, and adjusting the combustion amount of the burner. Combustion control means for executing calibration combustion control for supplying combustion air to the burner and for controlling the air supply means for supplying the combustion air to the burner so as to change the unburned component concentration. Based on the detection value of the calibration unburned component detection unit and the detection value of the unburned component detection sensor, which are detected along with the execution of the calibration combustion control, stored in the reference characteristic storage unit. Correction information detecting means for obtaining correction information for correcting the reference temperature characteristic and the reference sensitivity, wherein the density discriminating means is configured to detect the correction information based on the correction information obtained by the correction information detecting means. 2. The unburned component concentration detecting device for a combustion device according to claim 1, wherein the unburned component concentration is determined in a state where the reference temperature characteristic and the reference sensitivity stored in the quasi-characteristic storage means are corrected. 3. The normal combustion control in which the combustion control means controls the combustion amount adjusting means and the air supply means so as to adjust the combustion amount while maintaining an appropriate excess air ratio. The correction information detecting means is configured to obtain the correction information corresponding to each of the different combustion amounts according to the combustion amount adjusted along with the execution of the normal combustion control. Means for correcting the reference temperature characteristic and the reference temperature stored in the reference characteristic storage means based on the correction information obtained by the correction information detecting means in accordance with each of the different combustion amounts according to the change in the combustion amount. 3. The unburned component concentration detecting device for a combustion apparatus according to claim 2, wherein the unburned component concentration is determined while the sensitivity is corrected. 4. The combustion control unit is configured to execute the calibration combustion control at a preset set combustion amount for calibration, and the correction information detection unit is configured to execute the calibration combustion control. Along with obtaining the correction information corresponding to the set combustion amount for calibration, according to the combustion amount adjusted along with the execution of the normal combustion control, the correction information corresponding to each different combustion amount 4. The unburned combustion device according to claim 3, wherein the correction information is obtained based on the correction information corresponding to the set combustion amount for calibration and correction calculation information stored in advance in accordance with each of the different combustion amounts. Component concentration detector. 5. The reference sensitivity stored in the reference characteristic storage means is corrected so as to correspond to a fuel type different from the fuel type stored in the reference characteristic storage means in accordance with the reference sensitivity. Fuel type information storage means for storing fuel type change correction information for the fuel type in accordance with the fuel type, and fuel type setting means for setting the fuel type. The concentration discriminating means is provided by the fuel type setting means. When the set fuel type is different from the fuel type stored in the reference characteristic storage unit, the correction information obtained by the correction information detection unit and the fuel type change stored in the fuel type information storage unit are changed. And determining the unburned component concentration in a state in which the reference temperature characteristic and the reference sensitivity stored in the reference characteristic storage unit are corrected based on the correction information for use. Unburned component concentration detection apparatus of combustion device according to any one of claims 2-4 being. 6. The calibration unburned component detecting means is arranged in contact with the combustion gas of the burner, and detects a detected value corresponding to the concentration of the specific unburned component contained in the combustion gas. An unburned component detection sensor for calibration is output and the temperature characteristics and sensitivity are calibrated in advance to be the same or substantially the same as the reference temperature characteristics and reference sensitivity stored in the reference characteristic storage means. The unburned component concentration detecting device for a combustion appliance according to any one of claims 2 to 5, wherein 7. The combustion apparatus according to claim 2, further comprising: a notifying unit that performs a notifying operation when the correction information obtained by the correction information detecting unit is out of an appropriate range. Unburned component concentration detection device. 8. The unburned component concentration detecting device for a combustion apparatus according to claim 2, wherein each of said storage means is constituted by a nonvolatile storage element.