JPH0996438A - Control device for combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for combustion device, which can accurately perform an abnormality detection based on a driving current value of a gas proportional valve, which is detected, regardless of the size of a combustion quantity. SOLUTION: A required heating value operation part 35 operates a required heating value F based on a set temperature Ts, a coming-in water temperature detected value Tc and a flow rate detected value Q, and outputs to a proportional valve driving voltage operation unit 37. The operation unit 37 obtains a proportional valve driving voltage V corresponding with F, and outputs to a current reference value compensating unit 39. The compensating unit 39 obtains a proportional valve driving current reference value (Is) corresponding with the required heating value F, and outputs to a comparing unit 41. The comparing unit 41 reads an actual current value (Ir) from an actual current detecting unit 33, and judges whether the current reference value is larger than or equal to the actual current value (Ir). As a result, if (Is)>=(Ir), whether the actual current value (Ir) is larger than Is-ΔI2, which is a lower limit value to be considered as normal, or not is judged, and if it is not larger, the actual current value (Ir) is considered being abnormal. When (Is)<(Ir) whether the actual current value is smaller than (Is)+ΔI1, which is an upper limit value to be considered as normal, or not is judged, if it is not smaller, the actual current value (Ir) is considered being abnormal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a control device for controlling combustion in a combustion device such as a gas water heater.

[0002]

2. Description of the Related Art Conventionally, in a gas water heater having a two-stage burner, the drive current of a proportional valve for adjusting the amount of gas supplied to the burner is detected, and the drive current detection value is a preset drive current reference value. There is known a control device that determines that an abnormality has occurred when it is larger than the above and closes the combustion of the burner by closing an electromagnetic valve that disconnects / connects the gas supply to the burner.

[0003]

By the way, as shown in FIG. 1, the drive current reference value is fixed in accordance with the proportional valve drive current value at the time of maximum combustion when the gas water heater is in a normal state. Since it was the set value, it was effective in judging the normality / abnormality of the gas water heater at the time of maximum combustion.

However, when the combustion amount of the gas water heater is relatively small, even if an abnormality occurs and the drive current detection value becomes larger than that in the normal state, the reference value itself is much larger than the detection value. However, there is a problem in that it cannot be determined that an abnormality has occurred because the value is large.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a control device for a combustion device which can accurately detect an abnormality based on the detected drive current value of the gas proportional valve regardless of the amount of combustion.

[0006]

SUMMARY OF THE INVENTION A first aspect of the present invention is as follows.
In a combustion device equipped with a fuel supply amount adjustment valve for adjusting the fuel supply amount to the burner, an actual drive current for detecting an actual drive current for adjusting the fuel supply amount adjustment valve to an opening degree according to the required heat amount. Detecting means, drive current reference value determining means for determining a drive current reference value for determining whether or not the actual drive current is a normal value, the actual drive current, and the determined drive current It is characterized by having a judging means for judging whether the actual driving current is normal or abnormal by comparing it with a reference value.

In a preferred embodiment according to the first aspect of the present invention, the determining means stops the burner combustion operation when it is determined that the actual drive current is abnormal.

A second aspect of the present invention is a combustion apparatus including a fuel supply amount adjusting valve for adjusting a fuel supply amount to a burner, wherein the fuel supplying amount adjusting valve is adjusted to an opening degree according to a required heat amount. The actual drive current detection means for detecting the actual drive current and the drive current reference value for determining whether the actual drive current is a normal value are determined according to the actual combustion amount generated in the burner. Drive current reference value determining means, and a determining means for determining normal / abnormal of the actual drive current by comparing the actual drive current with the determined drive current reference value.

In a preferred embodiment of the second aspect of the present invention, the determining means stops the burner combustion operation when it is determined that the actual drive current is abnormal.

According to the first and second aspects of the present invention, the drive current reference value for determining whether or not the actual drive current is a normal value is determined according to the required heat amount (or actual combustion amount). However, since the normal drive / abnormality of the actual drive current is determined by comparing the actual drive current with the determined drive current reference value, the detected gas proportional valve is irrespective of the magnitude of the combustion amount. The abnormality can be accurately detected based on the drive current value of.

According to the preferred embodiments of the first and second aspects of the present invention, the combustion operation of the burner is stopped when it is determined that the actual drive current is abnormal. It is possible to improve.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 2 shows a schematic structure of a main part of an embodiment of a gas water heater to which the present invention is applied.

As shown in FIG. 2, the above-described water heater has branch pipes 5 and 7 for supplying gas and branch pipes 5 and 7 connected to the two-stage burners 1 and 3 and the burners 1 and 3, respectively. Provided are electromagnetic valves 9 and 11 for starting / stopping the supply of the gas fuel, a source gas pipe 13 from which the branch pipes 5 and 7 are branched, and a proportional valve 15 provided in the source gas pipe 13 for adjusting the gas amount. . The hot water supply device is provided with an original solenoid valve 1 for starting / stopping the supply of gas fuel provided upstream of the proportional valve 15 in the original gas pipe 13.
6. An intake fan 29 for sending necessary air to each of the burners 1 and 3 is also provided.

The water heater is also provided with a heat exchanger 17, which is arranged to face the burners 1 and 3, a water supply pipe 19 and a hot water supply pipe 23 connected to the heat exchanger 17, and water supply for measuring the incoming water temperature Tc. Inlet water temperature sensor 21 provided in the pipe 19 and flow rate sensor 2 provided in the water supply pipe 19 for measuring the hot water discharge flow rate Q
Also has 7.

The water heater further comprises a hot water outlet temperature sensor 25 provided in the hot water supply pipe 23 for measuring the hot water outlet temperature Tm, information Tc, Tm, Q from the sensors 21, 25, 27 and a hot water temperature setter (not shown). A control device 31 for controlling the valves 9, 11, 13, and 16, the intake fan 29, the igniter (not shown), and the like based on the set hot water temperature Ts is also provided.

FIG. 3 shows the functional elements of the part related to the present invention among the functional elements included in the control device 31. Corresponding functional elements include the actual current detection unit 33 and the required heat amount calculation unit 3
5, proportional valve drive voltage calculation unit 37, current reference value correction unit 3
9 and the comparison unit 41.

The actual current detector 33 detects the value Ir of the actual current supplied from a power source (not shown) when the proportional valve 15 is opened to a desired opening, and the detected actual current value Ir.
Is output to the comparison unit 39.

The required heat quantity calculation unit 35 determines the necessary heat quantity F for making the incoming water into the hot water of the set temperature F = (Ts-T) based on the set temperature Ts, the incoming water temperature detection value Tc and the flow rate detection value Q.
c) The calculation is performed by Q, and the calculated F is output to the proportional valve drive voltage calculation unit 37 and the reference current correction unit 39, respectively.

The proportional valve drive voltage calculation unit 37 reads the required heat amount F from the required heat amount calculation unit 35, and this required heat amount F
The proportional valve drive voltage V corresponding to V is calculated by V = f (F), and the calculated V is output to the proportional valve drive unit (not shown).

The current reference value correction unit 39 reads the required heat amount F from the required heat amount calculation unit 35 and detects the detected actual current value Ir.
Of the proportional valve drive current value (hereinafter referred to as "current reference value") Is as a reference value for determining normality / abnormality of the required heat quantity F
Determined according to. Then, the current reference value Is is output to the comparison unit 41.

The comparison unit 41 compares the actual current value Ir from the detection unit 33 with the current reference value Is from the correction unit 39,
When it is determined to be abnormal based on the comparison result, the solenoid valves 9 and 11 and the original solenoid valve 16 are closed to stop the combustion of the burners 1 and 3.

FIG. 4 shows the relationship between the required heat quantity F and the corresponding proportional valve drive current reference value according to an embodiment of the present invention.

In the present embodiment, the current reference value Is is calculated by the current reference value correction section 39 as shown by the solid line 51 in the necessary heat quantity F (actually, the calculation section 37 corresponds to the necessary heat quantity F from the calculation section 35). It is varied in accordance with the change in the proportional valve drive voltage V) calculated in. Then, when the comparing unit 41 determines that the actual current value Ir detected by the actual current detecting unit 33 is larger than the current reference value Is, it is normal if Ir is smaller than Is + ΔI1 shown by the broken line 53, and abnormal if larger. To be done. On the other hand, in the comparison unit 41, the actual current value Ir
Is determined to be smaller than the current reference value Is, it is determined to be normal if Ir is larger than Is-ΔI2 shown by the broken line 55, and abnormal if smaller.

For example, if the required heat quantity F is Fnow obtained only by burning the burner 1, the current reference value Isnow at that time is shown by a point 57 on the solid line 51. Therefore, when it is determined that the actual current value Irnow is larger than Isnow, Irnow is Isnow indicated by the broken line 53.
If it is smaller than + ΔI1 (that is, if it is in the area between the solid line 51 and the broken line 53), it is determined to be normal, and if it is greater than it is determined to be abnormal. On the contrary, when it is determined that the actual current value Irnow is smaller than the current reference value Isnow, if Irnow is larger than Isnow-ΔI2 shown by the broken line 55 (that is, if it is within the area between the solid line 51 and the broken line 55). Normal, and if small, it is determined to be abnormal.

The same applies to the case where the required heat quantity F is in a region larger than the value indicated by reference numeral 59 in FIG. 4, that is, in a region in which both the burners 1 and 3 are burned.

FIG. 5 shows the flow of the normal / abnormal determination operation of the actual current value Ir performed under the above-described functional configuration.

First, it is checked whether or not a combustion command has been given from an operation unit (not shown) having various switches (step S1), and when it is confirmed that the combustion command has been given, the required heat quantity F is F = It is calculated by (Ts-Tc) Q (step S2). Next, the proportional valve drive voltage V corresponding to this F is obtained from V = f (F) so that the required heat amount F can be obtained from the burners 1 and 3, and this voltage V is calculated by the proportional valve drive unit (not shown). Is applied (step S3), and a current reference value Is corresponding to the required heat quantity F is obtained (step S4).

Next, the actual current value Ir is read (step S
5) It is determined whether the current reference value Is is greater than or equal to the actual current value Ir (step S6). As a result, Is ≧ I
If r, whether the actual current value Ir is larger than Is-ΔI2 (value on the broken line 55 in FIG. 4) which is the lower limit value which is considered to be normal (that is, whether Is-Ir <ΔI2). Is determined (step S7), and if larger, it is determined to be normal. As a result of the above judgment, if it is small, it is judged to be abnormal, and the solenoid valves 9 and 11 and the original solenoid valve 16 are closed to stop the combustion operation of the burners 1 and 3 (step S8).

On the other hand, in step S6, Is <Ir
If so, it is determined whether or not the actual current value Ir is smaller than Is + ΔI1 (value on the broken line 53 in FIG. 4) which is the upper limit value which is considered to be normal (that is, whether Ir−Is <ΔI1). (Step S9) If it is smaller, it is determined to be normal. As a result of the above judgment, if it is large, it is judged to be abnormal, and the solenoid valves 9 and 11 and the original solenoid valve 1 are used to stop the combustion operation of the burners 1 and 3.
6 is closed (step S8). Even when a disconnection of a potentiometer (not shown) for adjusting the maximum drive current of the proportional valve 15 is detected at the time of maintenance of the gas water heater, the solenoid valves are used to stop the combustion of the burners 1 and 3. You may make it close-operate 9 and 11 and the former solenoid valve 16.

According to the above configuration, the required heat quantity F for making the incoming water into the hot water of the set temperature based on the set temperature Ts, the incoming water temperature detected value Tc and the flow rate detected value Q, and the proportional valve drive voltage V corresponding to this F , The drive current reference value Is is calculated, and the actual current value I
Since it was decided to determine normality / abnormality by comparing r with this Is, regardless of the magnitude of the combustion amount,
The abnormality can be accurately detected based on the detected drive current value. The required heat amount is a combustion amount that is a control target of the combustion amount that is determined according to the characteristics of the combustion device that is the control target according to the tapping temperature and the flow rate.

FIG. 6 shows functional elements included in the control device 45 according to another embodiment of the present invention.

The control device 45 of the present embodiment replaces the required heat quantity computing unit 35 described above with the hot water of the set temperature based on the hot water temperature Tm, the water temperature detection value Tc, and the flow rate detection value Q. The actual combustion amount Fr is Fr = (Tm-Tc) Q
The control device 31 is different from the control device 31 in that the actual combustion amount calculation unit 47 for calculating The other configurations are similar to those of the control device 31, and thus detailed description thereof will be omitted.

FIG. 7 shows a flow of the normal / abnormal determination operation of the actual current value Ir performed under the above-described functional configuration.

In FIG. 7, step S32 differs from step S2 of FIG. 5 in that the actual combustion amount Fr for making the incoming water into the hot water of the set temperature is calculated in the above-described manner. Other steps S31 and steps S33 to S39 are the same as the processing contents of step S1 and steps S3 to S9 in FIG. 4, so detailed description thereof will be omitted.

Also in the above configuration, the same effect as in the embodiment can be obtained.

The contents described above are only related to the respective embodiments of the present invention, and it goes without saying that the present invention is not limited to the above contents.

[0038]

As described above, according to the present invention,
It is possible to provide a control device for a combustion device that can accurately detect abnormality based on the detected drive current value of the gas proportional valve regardless of the amount of combustion.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a relationship between a conventional required heat amount F and a proportional valve drive current reference value.

FIG. 2 is a block diagram showing a schematic configuration of a gas water heater according to an embodiment.

FIG. 3 is a block diagram showing a functional configuration of a control device according to an embodiment.

FIG. 4 is an explanatory diagram showing a relationship between a required heat amount F and a proportional valve drive current reference value according to the embodiment.

FIG. 5 is a flowchart of a normal / abnormal determination operation of an actual current value Ir according to an embodiment.

FIG. 6 is a block diagram showing a functional configuration of a control device according to another embodiment.

FIG. 7 is a flowchart of a normal / abnormality determination operation of the actual current value Ir in another embodiment.

[Explanation of symbols]

 1, 3 Burner 9, 11 Solenoid valve 15 Proportional valve 16 Source solenoid valve 21 Inlet water temperature sensor 25 Outflow water temperature sensor 27 Flow rate sensor 29 Intake fan 31 Control device 33 Actual current detection unit 35 Required heat calculation unit 37 Proportional valve drive voltage calculation unit 39 Current reference value correction unit 41 Comparison unit

Claims (4)

[Claims] 1. A combustion apparatus including a fuel supply amount adjusting valve for adjusting a fuel supplying amount to a burner, wherein an actual driving current for adjusting the fuel supplying amount adjusting valve to an opening degree according to a required heat amount. A drive current reference value determining means for determining the drive current reference value for determining whether or not the drive current is a normal value, the drive current reference value determining means for determining whether the drive current is a normal value, A control device for a combustion apparatus, comprising: a determination unit that determines whether the actual drive current is normal or abnormal by comparing the current with the determined drive current reference value. 2. The combustion apparatus control device according to claim 1, wherein the determination means stops the combustion operation of the burner when it is determined that the actual drive current is abnormal. Control device. 3. A combustion apparatus including a fuel supply amount adjusting valve for adjusting a fuel supplying amount to a burner, wherein an actual driving current for adjusting the fuel supplying amount adjusting valve to an opening degree according to a required heat amount. And a drive current reference for determining a drive current reference value for determining whether the drive current is a normal value or not, according to the actual combustion amount generated in the burner. A value determining means; and a determining means for determining whether the actual drive current is normal or abnormal by comparing the actual drive current with the determined drive current reference value. Control device. 4. The combustion apparatus control device according to claim 3, wherein the determination means stops the combustion operation of the burner when it is determined that the actual drive current is abnormal. Control device.