JP3308428B2 - Water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas water heater for determining an operation amount (for example, an opening degree of a gas proportional valve) for supplying fuel gas and air based on a predetermined operation line.

[0002]

2. Description of the Related Art In a gas water heater, a required number of fuel gas and air are calculated according to a required number calculated from a set temperature, an incoming water temperature and an incoming water amount, or a corrected number obtained by correcting the required number based on an outgoing water temperature. The gas proportional valve and the combustion fan are operated to supply the gas to the gas burner, which is the combustion section. This operation is performed based on an operation line that provides a correspondence between the proportional valve current and the number corresponding to the opening degree of the gas proportional valve, and an operation line that provides a correspondence between the rotation number and the number of the combustion fan, These operation lines are set assuming a standard calorific value and a gas pressure of the fuel gas corresponding to the specifications of the apparatus. Therefore,
If fuel gas that meets the specifications of the equipment is used, the appropriate amount of fuel gas and air corresponding to the required number or correction number is supplied to the gas burner based on these operation lines, Combustion is performed at an appropriate air-fuel ratio, and the calorific value (actual number) as required is obtained, and the tapping temperature becomes equal to the set temperature.

[0003]

However, in a conventional gas water heater in which fuel gas and air in an amount corresponding to the required number are supplied based on the operation line, fuel gas of a type different from the specifications of the device is supplied. When used, the calorific value of the required number cannot be obtained. That is, the operation line L shown in FIG.
Assuming that the supply amounts of the fuel gas and the air are determined by 1 and L2, the proportional valve current corresponding to the supply amount of the fuel gas is the value I corresponding to the required number F1 by the operation line L1. When a fuel gas having a lower calorie than the fuel gas that meets the specifications is used, the relationship between the proportional valve current and the number becomes as shown by a straight line La in FIG.
Heat value actually obtained for proportional valve current I (actual number)
Is a value Fa smaller than the required number F1. When a fuel gas having a higher calorie than the fuel gas that meets the specifications of the apparatus is used, the relationship between the proportional valve current and the number becomes as shown by a straight line Lb in FIG.
The actual calorific value (actual number) for the required number is F
It becomes a value Fb larger than 1. If the required number of heat values (actual number) cannot be obtained, combustion cannot be performed at an appropriate air-fuel ratio. In other words, in order to obtain an appropriate air-fuel ratio, it is necessary to supply air in an amount corresponding to the actual number of fans. However, the fan rotation speed corresponding to the air supply amount corresponds to the required number F1 by the operation line L2. The value N, which is higher than the fan rotation speed Na corresponding to the actual number Fa when the low calorie fuel gas is used, and the actual number Fb when the high calorie fuel gas is used. It is lower than the corresponding fan speed Nb. As a result, the supply amount of air becomes excessive when low calorie fuel gas is used, and becomes insufficient when high calorie fuel gas is used.

On the other hand, in a conventional gas water heater in which fuel gas and air in an amount corresponding to the number of corrections are supplied based on the operation line, the outlet temperature is fed back via the number of corrections. Even if fuel gas of a type different from the specification is used, a tapping temperature equal to the set temperature can be obtained, and the actual calorific value is as required. That is, assuming now that the supply amounts of the fuel gas and the air are determined by the operation lines L1 and L2 shown in FIG. 7, when a fuel gas having a lower calorie than the fuel gas that meets the specifications of the apparatus is used,
By the feedback of the tapping temperature, the correction number Fm becomes larger than the required number F1, and the proportional valve current corresponding to the fuel gas supply amount becomes I2. As a result, the heat value (actual number) of the required number F1 is obtained. However, the fan speed at this time is a value N2 associated with the correction number Fm by the operation line L2, and is different from the value N1 corresponding to the actual number Fr (= request number F1). That is, since the fan rotation speed becomes the value N2 corresponding to the correction number Fm larger than the actual number Fr, the air supply amount becomes excessive. On the other hand, when a fuel gas having a higher calorie than the fuel gas that meets the specifications of the apparatus is used, the actual number Fr becomes equal to the required number F1 due to the feedback of the tapping temperature, as described above. The number Fm becomes smaller than the required number F1. Therefore, the fan rotation speed becomes a value corresponding to the correction number Fm smaller than the actual number Fr (= request number F1), and the air supply amount is insufficient.

As described above, in the conventional gas water heater, regardless of the presence or absence of feedback, if a gas of a type different from the specifications of the device is used, the supply amount of air becomes excessive or insufficient and an appropriate air-fuel ratio is obtained. Does not. As a result, phenomena such as blowout of the flame, increase of carbon monoxide, and generation of soot may occur.

The present invention has been made to solve such a problem, and an object of the present invention is to perform combustion at an appropriate air-fuel ratio even if a fuel of a type different from the specifications of the apparatus is used. An object of the present invention is to provide a hot water supply device which can be performed and does not cause phenomena such as blowing out of flame, increase of carbon monoxide, and generation of soot.

[0007]

[0008]

[Means for Solving the Problems] In order to solve the above-mentioned problems
In the first hot water supply apparatus according to the present invention, the required number is calculated based on the set temperature, the incoming water temperature and the incoming water amount, and the required number is calculated based on the deviation between the outgoing water temperature and the set temperature. The correction number is calculated by the correction, and the first operation line and the operation amount and the number of the first operation line for supplying air to the combustion unit, which provide a correspondence between the operation amount and the number for supplying the fuel to the combustion unit. (A) a hot water supply apparatus for determining an operation amount for supplying an amount of fuel and air to the combustion unit according to the correction number based on a second operation line that gives And b) comparing the actual number or the required number with the corrected number, and calculating a value indicating a difference between the compared numbers. A comparing means for outputting; and c) when an output value of the comparing means exceeds a predetermined allowable value. ,
Correction means for correcting one of the first operation line and the second operation line based on the output value.

In the second hot water supply apparatus according to the present invention,
The water heater according to the first aspect, further comprising a combustion stopping unit that stops the combustion in the combustion unit when an output value of the comparison unit exceeds a preset threshold value.

In the third hot water supply apparatus according to the present invention,
In one hot water supply apparatus, a storage unit that stores a correction amount of a first operation line or a second operation line by the correction unit, and the correction amount that is stored in the storage unit every time correction is performed by the correction unit. Updating means for updating, and learning correction means for performing correction based on a correction amount stored in the storage means for the first operation line each time combustion is started in the combustion unit, further comprising: I have.

[0011]

[0012]

In the first water heater according to the present invention, the required number is corrected based on the difference between the tapping temperature and the set temperature to calculate the corrected number, and the amount of fuel corresponding to the corrected number is calculated. And an operation amount for supplying air to the combustion unit is determined based on the first and second operation lines, and combustion is performed using fuel and air corresponding to the operation amount. Then, the actual number calculating means calculates the actual number based on the tap water temperature, the incoming water temperature, and the amount of incoming water obtained by the combustion. In the present hot water supply apparatus, the deviation between the tapping temperature and the set temperature is fed back to the supply amounts of fuel and air via the correction number, so that the tapping temperature and the set temperature become equal in a steady state, and as a result, the actual The number will be equal to the requested number. Here, if the calorie of the fuel actually used is lower than the proper number, the correction number will be larger than the actual number or the required number, and the calorie of the actually used fuel will be correct. If it is higher, the correction number will be smaller than the actual number or the required number. Therefore, in the present hot water supply apparatus, in order to determine whether or not the type of fuel being used is appropriate, the actual number or the required number is compared with the correction number by comparing means, and the difference between the compared numbers is determined. Is output.
If the output value exceeds a predetermined allowable value, it is considered that the type of fuel is not appropriate. Therefore, one of the first operation line and the second operation line is corrected by the correction unit based on the output value. Is done. As a result, the number of corrections becomes equal to the actual number. Thereafter, fuel and air in an amount corresponding to the actual number are supplied to the combustion section based on the first and second operation lines, and the combustion is performed at an appropriate air-fuel ratio. Is performed.

In the second hot water supply apparatus according to the present invention,
Similar to the first hot water supply apparatus , the actual number or the required number is compared with the corrected number, and a value indicating the difference between the compared numbers is output. If this output value is larger than the predetermined threshold value, the air-fuel ratio cannot be set to an appropriate value by the correction of the first operation line or the second operation line. Combustion is stopped.

In the third hot water supply apparatus according to the present invention,
Similarly to the first water heater, it is determined whether or not the output value of the comparing means exceeds an allowable value, that is, whether or not the type of fuel is appropriate. Thus, one of the first operation line and the second operation line is corrected. The correction amount at this time is stored in the storage means,
Thereafter, each time the first operation line or the second operation line is corrected, the correction amount stored in the storage unit is updated. And
When the combustion is started, the first operation line or the second operation line corrected based on the correction amount stored in the storage unit is used. Therefore, even if the fuel supplied to the combustion unit is of a type different from the specifications of the device, if the fuel is of the same type as that used in the previous combustion, the correction amount is calculated and operated again. Combustion is performed at an appropriate air-fuel ratio without correcting the line.

[0015]

【Example】

FIG. 1 is a block diagram showing the configuration of a gas water heater according to one embodiment of the present invention. In this gas hot water supply device, water is supplied to a heat exchanger 53, and the heat exchanger 53 is heated by a gas burner 54. At this time, the supply amounts of fuel gas and air used for combustion in the gas burner 54 are adjusted by a gas proportional valve 56 and a combustion fan 52, respectively. Also, this gas water heater
The gas proportional valve 56 is provided based on a water input amount Q, a water input temperature Tc, a hot water temperature Th, and a set temperature Ts detected by these sensors. Opening and combustion fan 5
2 is controlled. The control unit for controlling the opening of the gas proportional valve 56 and the rotation speed of the combustion fan 52 includes a required number calculation unit 12, a correction number calculation unit 14, a timer 16,
It comprises a comparison unit 18, a real number calculation unit 22, a notification unit 24, an operation line correction unit 26, a learning storage unit 28, a gas proportional valve drive unit 30, a combustion stop unit 32, and a combustion fan drive unit 34.

[Operation of Each Unit in the Control Unit] In the above configuration, the required number calculation unit 12 includes the water input amount Q and the set temperature Ts.
The required number F1 is calculated by the following equation based on the input water temperature Tc. F1 = Q · (Ts-Tc)

The correction number calculating section 14 includes a PID calculating section 14.
a and a multiplier 14b, and a PID operation unit 14a
Is the deviation ΔT between the set temperature Ts and the tapping temperature Th = Ts−Th
Is calculated based on the feedback amount.
The coefficient αFB is a coefficient calculated from the proportional value, the integral value, and the differential value of the deviation ΔT, and if the type of the fuel gas used is appropriate, that is, it matches the specifications of the gas water heater. ΑFB = 1, αFB <1 when the calorie is higher than the proper one, and αFB> 1 when the calorie is lower than the proper one (hereinafter, this coefficient αFB is referred to as “feedback coefficient”). This feedback coefficient αFB
Is multiplied by the required number by the multiplier 14b, and the value obtained as a result is output from the correction number calculation unit 14 as the correction number Fm.

The actual number calculating section 22 calculates the actual number Fr, which is the number actually output, based on the amount of incoming water Q, the tap water temperature Th, and the incoming water temperature Tc by the following equation. Fr = Q · (Th-Tc)

Using the timer 16, the comparing section 18 compares the actual number Fr calculated as described above with the correction number Fm for a predetermined time (for example, one minute). As a result of this comparison, if the difference between the actual number Fr and the corrected number Fm is equal to or more than a certain value,
A correction command is issued to the operation line correction unit 26. That is,
The ratio Fr / Fm between the actual number and the corrected number is calculated.
If the deviation from the value exceeds a predetermined allowable value, it is determined that the used fuel gas is not appropriate, and a correction command is issued to the operation line correction unit 26.

The operation line correction unit 26 corrects the operation line for the gas proportional valve 56 or the combustion fan 52 according to the ratio Fr / Fm between the actual number and the correction number calculated by the comparison unit 18. Hereinafter, this correction operation will be described.

FIG. 2 shows operation lines (hereinafter referred to as "proportional valve operation lines") L1 and L1m for providing a correspondence between the proportional valve current and the number of the gas proportional valve 56, and the number of rotations and the number of the combustion fan 52. An operation line (hereinafter, referred to as a "fan operation line") L2 giving a correspondence with a number is shown. When correcting the proportional valve operation line for the first time, the opening degree of the gas proportional valve 56 is controlled based on the initial operation line L1, which is an uncorrected proportional valve operation line, and the fuel gas corresponding to the opening degree is controlled. Combustion is performed by the supply. Upon receiving the correction command, the operation line correction unit 26 changes the maximum number Fmax indicated by the initial operation line L1 to Fmax2 = (Fr / Fm) · Fmax, and changes the minimum number Fmin to Fmin2 = (Fr / Fm).・ Change to Fmin. However, the maximum proportional valve current Imax and the minimum proportional valve current Imin are not changed. Therefore, as shown in FIG. 2, two points (Fmax2, Imax) and (Fmin2, Imin) in the graph in which the number is the horizontal axis and the proportional valve current is the vertical axis.
Is the corrected proportional valve operation line L1m. As can be seen from FIG. 2, the proportional valve current I associated with the actual number Fr by the proportional valve operation line L1m after the correction is the proportional valve current I associated with the corrected number Fm by the proportional valve operation line L1 before the correction. Since the current is equal to the current, the correction number Fm after correction is equal to the actual number Fr.

When correcting the fan operation line, as shown in FIG. 3, the number of revolutions of the combustion fan 52 is controlled based on an initial operation line L2 which is an uncorrected fan operation line. Combustion is performed by the supply of air according to the number. Upon receiving the correction command, the operation line correction unit 26 changes the maximum number Fmax indicated by the initial operation line L2 to Fmax2 = (Fr / Fm) · Fmax, and changes the minimum number Fmin to Fmin2 = (Fr / Fm). -By changing to Fmin, the same effect as when the proportional valve operation line is corrected can be obtained.

After the operation line is corrected in this way, the correction amount is stored in the learning storage unit 28. In the present embodiment, the ratio Fr / Fm used for correction is stored in the learning storage unit 28 as the correction amount r.

The operation line corrector 26 corrects the proportional valve operation line L1m by correcting the initial operation line L1 based on the correction amount r stored in the learning storage unit 28 when the combustion starts thereafter. Then, a signal indicating the value of the proportional valve current I associated with the correction number Fm by the proportional valve operation line L1m is given to the gas proportional valve drive unit 30. The gas proportional valve drive unit 30 supplies the proportional valve current I to the gas proportional valve 56 based on this signal and drives the gas proportional valve 56 to set the valve opening corresponding to the proportional valve current I. As a result, an amount of fuel gas corresponding to the correction number Fm is supplied to the gas burner 54. Further, the operation line correction unit 26 gives a signal indicating the value of the fan rotation speed N associated with the correction number Fm by the fan operation line L2 to the combustion fan drive unit 34. The combustion fan drive unit 34 rotates the combustion fan 52 at the rotation speed N based on this signal. This allows
An amount of air corresponding to the correction number Fm is supplied to the gas burner 54.

The operation line correction unit 26 corrects the fan operation line L2m by correcting the initial operation line L2 based on the correction amount r stored in the learning storage unit 28 at the time when the combustion starts thereafter. Then, a signal indicating the value of the fan speed N associated with the correction number Fm by the fan operation line L2m may be given to the combustion fan drive unit 34. The combustion fan drive unit 34 supplies the fan rotation speed N to the combustion fan 52 based on the signal and drives the combustion fan 52 to make the rotation speed correspond to the fan rotation speed N. As a result, an amount of air corresponding to the correction number Fm is supplied to the gas burner 54. The operation line correction unit 26 uses the proportional valve operation line L1 to perform the correction number Fm.
A signal indicating the value of the proportional valve current I associated with the proportional valve current I associated with is supplied to the gas proportional valve control unit 30. The gas proportional valve drive unit 30 sets the gas proportional valve 56 to a valve opening corresponding to the proportional valve current I based on this signal. As a result, an amount of fuel gas corresponding to the correction number Fm is supplied to the gas burner 54.

Combustion is performed by the gas burner 54 using the fuel gas and the air supplied as described above, and hot water supply is realized. After the actual number calculation unit 22 calculates the actual number Fr using the tapping temperature Th, the actual number Fr is compared with the correction number Fm. If so, the correction of the proportional valve operation line or the fan operation line is performed. Assuming that the ratio Fr / Fm used for the correction at this time is r0, the ratio Fr / Fm and the correction amount r stored in the learning storage unit 28
The product r0 × r of the learning storage unit 28 is used as a new correction amount r.
Is stored. In this way, each time the operation line is corrected by the operation line correction unit 26, the correction amount r stored in the learning storage unit 28 is updated.

The operation line correction unit 26 corrects the proportional valve operation line or the fan operation line as described above, and also corrects the correction amount r0.
Each time is calculated, the product r0 × r (which corresponds to the correction amount for the initial operation line L1) of this and the correction amount r stored in the learning storage unit 28 is set to a preset first threshold value. It is determined whether or not the threshold value has been exceeded. If the threshold value has been exceeded, a warning is issued by the notification unit 24. Thereby, the user can recognize that it is difficult to make a normal combustion state by correcting the proportional valve operation line because the correction amount r0 × r is large. Also, the correction amount r0 × r for the initial operation line L1
Exceeds a second threshold value set in advance as a value larger than the first threshold value, the combustion stop unit 32 closes the gas solenoid valve 64 to stop the supply of the fuel gas to the gas burner 54, thereby stopping the combustion. Stop. Thereby, abnormal combustion can be prevented.

[Overall Operation of Embodiment] FIG. 5 is a flowchart showing the overall operation of the gas water heater of the above configuration when the proportional valve operation line is corrected. When the gas water heater is started, first, it is determined whether an ignition condition is satisfied (step S10). If the ignition condition is satisfied, the opening degree of the gas proportional valve 56 and the rotation speed of the combustion fan 52 are controlled based on the proportional valve operation line and the fan operation line. Under this control, the fuel gas and the gas are supplied to the gas burner 54. Air is supplied to start combustion (step S12). At this time, a proportional valve operation line L1m obtained by correcting the initial operation line L1 based on the correction amount stored in the learning storage unit 28 is used. Then, depending on the proportional valve current associated with the correction number Fm by the proportional valve operation line L1m and the rotational speed of the combustion fan 52 associated with the correction number Fm by the fan operation line, the fuel gas and air Is supplied to the gas burner 54.

Thereafter, it is determined whether or not the hot water temperature Th and the incoming water quantity Q are stable (step S14). If the hot water temperature Th and the incoming water quantity Q are stable, the actual number calculating section 2
2, the actual number Fr is calculated (step S16). Incidentally, as described above, the correction number Fm is obtained by multiplying the required number F1 by a feedback coefficient αFB calculated based on a deviation ΔT = Ts−Th between the tapping temperature Th and the set temperature Ts, An amount of fuel gas corresponding to the correction number Fm is supplied to the gas burner 54. That is, the difference ΔT = Ts−Th between the tapping temperature Th and the set temperature Ts is fed back to the fuel gas supply amount via the correction number. Therefore, in a steady state, tapping temperature Th becomes equal to set temperature Ts, and as a result, actual number Fr becomes equal to required number F1. Here, if the type of fuel gas is appropriate, the correction number F
m is also equal to the required number F1. However, if the calorie of the fuel gas is higher than the proper one, the feedback coefficient αFB becomes smaller than 1, so the correction number Fm becomes smaller than the actual number Fr, and the calorie of the fuel gas becomes higher than the proper one. If it is low, the feedback coefficient αFB becomes larger than 1, so that the correction number Fm becomes larger than the actual number Fr. Therefore, when the type of fuel gas is not appropriate, an amount of air corresponding to the correction number Fm different from the required number F1 (= actual number Fr) is supplied to the gas burner 54 (see FIG. 2). ). As a result, an appropriate air-fuel ratio cannot be obtained.

Therefore, as described above, the value of the ratio Fr / Fm between the actual number and the corrected number is calculated in the comparing section 18, and it is determined whether or not this ratio is substantially equal to 1 (step S1).
8). If this ratio is approximately equal to 1, combustion is continued as it is (step S22), but if the deviation of this ratio from 1 exceeds a predetermined allowable value, the type of fuel gas used is The operation line correction unit 2
6, a correction command is issued. When the correction command is issued, the operation line correction unit 26 determines whether the deviation of the ratio Fr / Fm from 1 exceeds a predetermined allowable value (Fr / Fm).
Is substantially equal to 1) (step S1).
8) If it does not exceed the allowable value, the proportional valve operation line is corrected based on the ratio Fr / Fm (step S20).
The correction amount stored in the learning storage unit 28 is updated based on the correction amount at this time.

After the proportional valve operation line is corrected as described above, the gas proportional valve 5 is then operated based on the corrected proportional valve operation line until the operator instructs to stop hot water supply.
6, the combustion is continued under this control (step S22). In this combustion, step S
The fuel gas supply amount does not change compared to before the correction of the proportional valve operation line at 20. However, the value of the correction number Fm is changed to the required number F1.
(= The actual number Fr), the rotation speed of the combustion fan 52 changes, and the supply amount of air changes accordingly (see FIG. 2). As a result, the gas burner 54 performs combustion at an appropriate air-fuel ratio.

If the ignition condition is not satisfied in the step S10, the combustion is not started. If the tapping temperature Th and the water input amount Q are not stable in the step S14, the combustion is stopped. In this case, the operation of the gas hot water supply device is also canceled. FIG.
Although not shown in the flowchart of the above, as described above, the operation line correction unit 26 corrects the proportional valve operation line,
Each time the correction amount is calculated, it is determined whether or not the correction amount r0 × r for the initial operation line L1 has exceeded a first threshold value.
If the threshold value is exceeded, a warning is issued by the notification unit 24, and the correction amount r0 × r for the initial operation line L1 is equal to the second threshold value (> first threshold value).
(Threshold value), the combustion is stopped by the combustion stopping unit 32.

[Effects of the Embodiment] As described above, according to the present embodiment, when a fuel gas of a type different from the specifications of the apparatus, that is, an inappropriate fuel gas is used, the actual number Fr and the correction signal are used. It is recognized from the difference from the number Fm that the type of fuel gas is not appropriate, and the proportional valve operation line or the fan operation line is corrected so that the correction number Fm becomes equal to the actual number Fr. Accordingly, even when a type of fuel gas different from the specifications of the apparatus is used, combustion can be performed at an appropriate air-fuel ratio within the set range of the proportional valve operation line. As a result, the flame blows out, carbon monoxide increases,
The generation of soot is also prevented.

According to the present embodiment, a warning is issued when the amount of correction of the proportional valve operation line is large and it is difficult to perform combustion in a normal state by the correction alone. The person can recognize that it is difficult to make a normal combustion state by correcting the proportional valve operation line or the fan operation line. If the amount to be corrected is larger, the combustion is stopped, whereby abnormal combustion can be prevented.

Further, when the combustion is started in this embodiment, the proportional valve operation line L1m or the initial operation line L2 obtained by correcting the initial operation line L1 based on the correction amount stored in the learning storage unit 28 is used. Since the corrected fan operation line L2m is used, even when a fuel gas of a type different from the device specifications is used, a fuel gas of the same type as the fuel gas used in the previous combustion is used. Thus, the normal combustion state can be achieved without calculating the correction amount of the proportional valve operation line or the fan operation line.

[Modification] In the above embodiment, whether or not the type of fuel gas is appropriate is determined based on the ratio Fr / Fm of the actual number Fr and the correction number Fm. Since the deviation ΔT = Ts−Th from the set temperature Ts is fed back to the supply amount of the fuel gas and the air via the correction number, the tapping temperature Th becomes equal to the set temperature Ts in a steady state. As a result, the actual number Fr becomes equal to the required number F1, and it may be determined whether or not the fuel gas type is appropriate based on the ratio F1 / Fm of the required number F1 and the correction number Fm. In addition,
As can be seen from the method of calculating the correction number Fm in the correction number calculation unit 14, the ratio F1 between the required number F1 and the correction number Fm is obtained.
Determination using / Fm is equivalent to determination using the reciprocal 1 / αFB of the feedback coefficient.

On the other hand, unlike the above embodiment, the tapping temperature T
When the feedback control based on the deviation ΔT between h and the set temperature Ts is not performed, the correction number calculation unit 14 is not provided, and the required number F1 is directly input to the comparison unit 18 and the operation line correction unit 26, The configuration is such that the supply amounts of fuel gas and air are determined based on the required number F1. In this case,
If the calorie of the fuel actually used is lower than the proper one, the actual number Fr becomes smaller than the required number F1, and if the calorie of the fuel actually used is higher than the proper one, The actual number Fr becomes larger than the required number F1. Therefore, the comparison unit 18 uses the ratio Fr / F1 of the actual number Fr and the required number F1 instead of the ratio Fr / Fm of the actual number Fr and the correction number Fm, thereby obtaining the operation line correction unit. It is possible to determine whether or not a correction command should be issued to 26.

When correcting the proportional valve operation line in the above embodiment, the maximum number Fmax and the minimum number Fmin indicated by the proportional valve operation line are changed according to the ratio Fr / Fm. Instead of changing Fmax and Fmin, the maximum proportional valve current Imax and the minimum proportional valve current Imin indicated by the proportional valve operation line may be changed according to the reciprocal of the ratio Fr / Fm. That is, the maximum proportional valve current Ima
x is changed to Imax2 = (Fm / Fr) .Imax, and the minimum proportional valve current Imin is changed to Imin2 = (Fm / Fr) .Imin. As shown in FIG. Two points (Fmax,
A line connecting Imax2) and (Fmin, Imin2) may be used as the corrected proportional valve operation line L1m. According to the correction method of the above embodiment (FIG. 2), the number at the time of maximum combustion may decrease, but according to this correction method (FIG. 4), the number at the time of maximum combustion is maintained as it is before correction. Although not shown in FIG. 4, when correcting the fan operation line L2, the maximum rotation speed Nmax is set to Nmax2 = (Fm / Fr) · Nmax, and the minimum rotation speed Nmin is set to Nmin2 = (Fm / Fr). ) · Nmin, the corrected fan operation line L2m
It may be.

[0039]

According to the first water heater according to the present invention,
Even if a type of fuel different from the specifications of the device is used, it is possible to burn at an appropriate air-fuel ratio by correcting the operation line. As a result, the blow-off and flames, an increase of carbon monoxide, Ru it is possible to prevent the soot of occurrence.

According to the second hot water supply apparatus of the present invention, in addition to the above-described effects, if the amount of operation line to be corrected is large and combustion cannot be performed in a normal state by the correction alone, the combustion Automatically stops, abnormal combustion can be prevented beforehand.

According to the third hot water supply apparatus of the present invention, each time combustion is started, the operation line is corrected based on the correction amount stored in the storage means. For this reason, in addition to the effect of the first hot water supply device, even when a type of fuel different from the specifications of the device is used, the same type of fuel as that used in the previous combustion is used. At times, a normal combustion state can be achieved without performing the correction of the operation line again.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a gas water heater according to one embodiment of the present invention.

FIG. 2 is a diagram showing a proportional valve operation line and a fan operation line in the embodiment.

FIG. 3 is a diagram showing another example of the proportional valve operation line and the fan operation line in the embodiment.

FIG. 4 is a diagram showing a proportional valve operation line and a fan operation line in a modification of the embodiment.

FIG. 5 is a flowchart showing the overall operation of the gas water heater of the embodiment.

FIG. 6 is a diagram for explaining an operation when an inappropriate fuel gas is used in a conventional gas water heater that does not perform feedback control.

FIG. 7 is a diagram for explaining an operation when an inappropriate fuel gas is used in a conventional gas water heater that performs feedback control.

[Explanation of symbols]

12 required number calculation unit 14 correction number calculation unit 18 comparison unit 22 actual number calculation unit 24 notification unit 26 operation line correction unit 28 learning storage unit 32 combustion stop unit Ts set temperature Tc … Inlet water temperature Th… Tap water temperature Q… Incoming water quantity F1… Requested number Fr… Real number Fm… Correction number L1… Initial proportional valve operation line L1m… Proportional valve operation line after correction L2… Initial fan operation line L2m… Fan operation line after correction

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-117809 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23N 1/02 F24H 1/10 302

Claims (3)

(57) [Claims] 1. A required number is calculated based on a set temperature, an incoming water temperature, and an incoming water amount, and a corrected number is calculated by correcting the required number based on a deviation between a hot water temperature and a set temperature. Based on a first operation line for providing a correspondence between an operation amount and a number for supplying fuel to the combustion unit and a second operation line for providing a correspondence between the operation amount and the number for supplying air to the combustion unit. A hot water supply apparatus for determining an operation amount for supplying an amount of fuel and air to the combustion unit in accordance with the correction number; a) calculating an actual number based on a tapping temperature, an input temperature, and an input amount; Number calculating means; b) comparing means for comparing the actual number or the required number with the correction number and outputting a value indicating a difference between the numbers to be compared; c) comparing means If the output value exceeds the specified tolerance,
Correction means for correcting one of the first operation line and the second operation line based on the output value. 2. The hot water supply apparatus according to claim 1, further comprising: combustion stopping means for stopping the combustion in the combustion section when an output value of the comparing means exceeds a preset threshold value. apparatus. 3. The hot water supply apparatus according to claim 1 , wherein a storage unit stores a correction amount of the first operation line or the second operation line by the correction unit, and a storage unit for each correction by the correction unit. Updating means for updating the correction amount stored in the storage section, and correcting the first operation line or the second operation line based on the correction amount stored in the storage means each time combustion is started in the combustion section. And a learning correction means for performing the following.