JP2675516B2 - 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 combustion equipment such as a water heater,
In particular, the present invention relates to a combustion device provided with means for detecting incomplete combustion in a combustion section by an unburned gas sensor such as a CO sensor.

[0002]

2. Description of the Related Art Conventionally, in this type of apparatus, for example, an unburned gas sensor for detecting unburned gas such as CO is provided in an exhaust passage connected to a combustion chamber of a water heater, and the amount of unburned gas is measured. It is known that the incomplete combustion state is detected by the output of the corresponding unburned gas sensor and the combustion operation is stopped by this, and in this type, when the output of the unburned gas sensor exceeds a predetermined judgment level. It is determined that an incomplete combustion state has occurred, and the combustion operation is stopped accordingly.

An incomplete combustion state in which the output of the unburned gas sensor exceeds a predetermined determination level includes an incomplete combustion state caused by blockage of an exhaust passage and an air supply passage, clogging of fins, and the like, and a combustion chamber of a water heater. There is an incomplete combustion state in which strong air is blown into the combustion chamber and the air supply to the combustion chamber is obstructed, and the former incomplete combustion state causes clogging of exhaust passages and air supply passages, clogging of fins, etc. Unless excluded
Although not resolved, the latter incomplete combustion condition is generally temporary and resolves spontaneously. Then, when the former incomplete combustion state occurs, the combustion operation is stopped,
In addition, it is desirable that the combustion operation cannot be restarted unless the cause such as the blockage of the exhaust passage is resolved.When the latter incomplete combustion state occurs, the combustion operation is continued or the combustion operation is stopped. It is desirable to be able to restart the combustion operation even if it is once stopped.

However, in the conventional case, the output of the unburned gas sensor is not distinguished from the continuous incomplete combustion state due to the blockage of the exhaust passage and the air supply passage and the temporary incomplete combustion state due to the wind. Since the combustion operation is stopped when exceeds the predetermined judgment level, there is the following inconvenience.

That is, if the combustion operation is stopped when the output of the unburned gas sensor exceeds a predetermined judgment level, the combustion operation cannot be restarted due to the stop, and a temporary failure due to wind or the like occurs. Even if the combustion operation is stopped due to the complete combustion state, the subsequent combustion operation cannot be performed. Further, if the combustion operation can be restarted, the combustion operation may be temporarily restarted when the combustion operation is stopped due to an incomplete combustion state caused by the blockage of the exhaust passage or the like.

Further, when the combustion operation is stopped when the output of the unburned gas sensor exceeds a predetermined judgment level as in the conventional case, the combustion operation is frequently stopped due to a temporary incomplete combustion state due to wind or the like. Therefore, it is difficult for the user to use.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above background, and it is possible to perform an appropriate driving operation according to the situation of occurrence of incomplete combustion. An object of the present invention is to provide a combustion device capable of eliminating erroneous stoppage of combustion operation due to a temporary incomplete combustion state.

[0008]

In order to achieve the above object, the present invention provides an unburned gas sensor provided in an exhaust passage communicating with a combustion section, and an output of the unburned gas sensor is a predetermined incomplete combustion determination. In a combustion device including an incomplete combustion determination unit that outputs a combustion operation stop command when the criteria are satisfied, and an operation control unit that stops the combustion operation in accordance with the combustion operation stop command of the incomplete combustion determination unit, The operation control means includes a gas change detection means for detecting a temporal decrease rate of the output of the unburned gas sensor after the combustion operation is stopped, and the operation control means includes the unburned gas sensor detected by the gas change detection means. When the temporal decrease rate of the output of is less than or equal to a predetermined value, restart of the combustion equipment is disabled, and when the temporal decrease rate is larger than the predetermined value, a predetermined operation is performed. Characterized in that it is configured to allow the restarting of the combustion equipment by.

Further, the incomplete combustion determination means outputs the combustion operation stop command when the output of the unburned gas sensor continues for a predetermined time and becomes a predetermined determination value or more.

Further, the incomplete combustion determination means outputs the combustion operation stop command when an integrated output value obtained by integrating the outputs of the unburned gas sensor within a predetermined time is equal to or greater than a predetermined determination value. It is characterized by

[0011]

According to the present invention, when the combustion operation is stopped due to incomplete combustion, when the temporal decrease rate of the output of the unburned gas sensor after the stop is less than or equal to a predetermined value, in other words, When the unburned gas amount after the combustion operation is stopped does not decrease easily, the combustion device is not restarted. Therefore, when the incomplete combustion occurs due to the blockage of the exhaust passage, the combustion operation is performed. Be sure to avoid the situation where is restarted. Further, when the temporal decrease rate of the output of the unburned gas sensor after the stop of the combustion operation is larger than the predetermined value, in other words, when the unburned gas amount after the stop is rapidly decreased, the combustion is performed. Since it is possible to restart the equipment, it is possible to restart the combustion operation without any trouble if incomplete combustion occurs due to wind or the like.

When stopping the combustion operation, the combustion operation is stopped when the output of the unburned gas sensor continues for a predetermined time and becomes a predetermined judgment value or more, or the output of the unburned gas sensor is changed within a predetermined time. By stopping the combustion operation when the output integrated value that is integrated by the above becomes equal to or greater than the predetermined judgment value, the combustion operation will be continued if temporary incomplete combustion occurs due to wind, etc. .

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory sectional view of a water heater provided with the present embodiment,
FIG. 2 is a block diagram of the main part of FIG. 1, and FIGS. 3 and 4 are flow charts for explaining the operation of this embodiment.

As shown in FIG. 1, a forced combustion gas water heater A includes a gas burner 2 that burns in a combustion housing 1.
(Combustion section), and the blower fan 3 supplies the combustion air X of the gas burner 2 to the combustion housing 1. Also,
In the water heater A, the combustion control device 4 supplies gas to the gas burner 2, ignites the gas burner 2, and controls the combustion fan 3.

The combustion housing 1 is provided below with combustion air X.
A discharge port 6 for discharging the combustion exhaust gas Z to the outside is provided above the introduction port (not shown). A heat exchanger 7 is provided above the gas burner 2 in the combustion housing 1.
Are arranged.

The gas burner 2 comprises a burner group 8 for forming a flame, and a nozzle tube 10 located below the burner group 8 and having an ejection port 9. The fuel gas Y is supplied to the gas burner 2 through the gas pipe 11. The blower fan 3 has turbo-type blades.

The combustion control device 4 includes a water amount regulator 12, a water amount sensor 13, a thermistor 14, a source gas solenoid valve 15, a main solenoid valve 16, a governor type gas proportional solenoid valve 17, an igniter 18, a frame rod 19, and a CO sensor. 20 (unburned gas sensor) and a controller 21 for controlling them. The controller 21 has, as its functional configuration, a combustion control means 22 (operation control means) and a CO as shown in FIG.
The microcomputer includes a sensor control unit 23, an incomplete combustion determination unit 24, and a gas change detection unit 25.

Next, the controller 21 of the combustion control device 4
Will be described with reference to FIG.

When a hot water supply tap (not shown) is opened while an operation switch (not shown) is turned on, the controller 21 detects this by the water amount sensor 13 and causes the combustion control means 22 to operate the blower fan 3. The gas burner 2 is driven, and the igniter 18 is operated. At the same time, the original gas solenoid valve 15, the main solenoid valve 16 and the proportional solenoid valve 17 are controlled to open to supply the fuel gas to the gas burner 2, thereby igniting the gas burner 2. Then, the combustion operation of the water heater is started. At this time, when the gas burner 2 is ignited, the ignition is detected by the frame rod 19, and if the ignition by the operation of the igniter 18 is not detected, the igniter 18 and the original gas solenoid valve 15 are turned off to operate the water heater. To stop.
When the ignition is detected, the igniter 18 is turned off, then the proportional control of the gas amount is performed by the proportional solenoid valve 17, and the CO sensor 20 is energized by the CO sensor control means 23 to start it. An incomplete combustion detection operation to be described later is performed by the sensor 20 and the incomplete combustion determination means 24 and the like. The gas amount proportional control and the incomplete combustion detection operation are continuously performed until the hot water tap is closed.

When the hot water tap is closed, the controller 21 detects this with the water amount sensor 13, and the combustion control means 22 causes the source gas solenoid valve 15, the main solenoid valve 16,
By controlling the proportional solenoid valve 17 to close, the gas burner 2 is extinguished, the driving of the combustion fan 3 is stopped, and the CO sensor 20 is turned off, thereby stopping the combustion operation of the water heater. The energization of the CO sensor 20 may be started, for example, when the ON signal is output from the water amount sensor 13, and can be appropriately selected. Further, the CO sensor 20 may be energized at all times.

Next, the incomplete combustion detection operation will be described in detail with reference to FIG.

The basic operation of this incomplete combustion detection operation will be described. The controller 21 determines that the CO concentration (CO value) detected by the output of the CO sensor 20 corresponds to the incomplete combustion state of the gas burner 2. The state where the value is equal to or greater than the predetermined judgment value is the predetermined timer time (detection timer time)
When it continues, stop the combustion operation.

More specifically, when the combustion operation is started and the CO
When the sensor 20 is activated, the CO sensor 20 outputs C
An O value is detected. At this time, the incomplete combustion determination means 24 of the controller 21 determines that the detected CO value is a predetermined determination value (for example, a CO concentration of 2000 ppm) due to incomplete combustion.
Then, the detection timer 24a (see FIG. 2) built in the incomplete combustion determination means 24 is started.

When the CO value becomes equal to or more than the predetermined judgment value as described above, the incomplete combustion judgment means 24 changes its state to the timer time of the detection timer 24a, that is, the time after the detection timer 24a starts. It is monitored whether it continues for a while until it comes up. When the state in which the CO value becomes equal to or greater than the predetermined determination value continues for the timer time of the detection timer 24a, the incomplete combustion determination means 24 operates the combustion control means 22, and the original gas solenoid valve 15, the main solenoid valve 16, and the proportional solenoid valve. 17 is closed so that the gas burner 2 is extinguished and the combustion fan 3 is stopped, thereby stopping the combustion operation of the water heater. The original gas solenoid valve 15
And the like and the combustion fan 3 are turned off at substantially the same time.

When the combustion operation is stopped in this way, the gas change detecting means 25 of the controller 21 is
The temporal decrease rate of the CO value detected by the sensor 20 is detected. This detection is performed, for example, by detecting the CO value with the CO sensor 20 when the combustion operation is stopped and when a predetermined time has elapsed from the stop, and detecting the amount of change in the CO value at each of these times. . Then, the gas change detection means 25 detects when the temporal decrease rate of the CO value detected as described above is larger than a predetermined value, that is, when the CO value after the operation is stopped is rapidly decreased. Sets the value of "Flag" to "0".

Here, "Flag" defines the condition for enabling or disabling the combustion operation, and Flag = 0 corresponds to the case where the combustion operation can be restarted, and Flag is = 1 corresponds to the case where the restart of the combustion operation is disabled. That is, referring to FIG. 3, in the present embodiment, the combustion control means 22 of the controller 21 determines whether the value of “Flag” is “0” or “1” at the start of combustion operation. And Flag =
In the case of 0, the combustion operation is performed as described above, and the Fla
If g = 1, turn on the operation switch (not shown)
However, the combustion operation does not start even if the hot water tap (not shown) is opened. Therefore, when the temporal decrease rate of the CO value is larger than a predetermined value, by setting Flag = 0, for example, the operation switch is turned on again, and the hot water tap is further opened to start the combustion operation. Resume.

As a result, if the exhaust port 6 is not clogged and incomplete combustion occurs for a certain period of time due to continuous wind or the like and the combustion operation is stopped and the combustion operation is stopped, the combustion operation is stopped. The combustion operation can be restarted without any trouble.

When the rate of decrease of the CO value with time is equal to or less than the predetermined value, that is, when the CO value after the operation is stopped does not easily decrease due to the blockage of the discharge port 6 or the like, the controller 21 gas change detection means 25
Sets the value of "Flag" to "1" and transfers it to the combustion control means 22. Therefore, resumption of combustion operation is prohibited.

As a result, when continuous incomplete combustion occurs due to the blockage of the discharge port 6 or the like and the combustion operation is stopped, the subsequent combustion operation is prohibited, and the combustion operation is performed in such a state. It is possible to reliably avoid such a situation.

On the other hand, referring to FIG. 4, in the incomplete combustion detection operation, within the detection timer time (detection timer 2
Before the time-up of 4a), when the CO value becomes smaller than the judgment value, that is, although the CO value once becomes the judgment value or more, the CO value becomes smaller than the judgment value again within the detection timer time. In this case, the incomplete combustion determination means 24 stops the detection timer 24a until the CO value becomes equal to or more than the determination value again.

Thus, when a temporary incomplete combustion state occurs due to a temporary wind or the like, the combustion operation is continued.

Next, another embodiment of the present invention will be described with reference to FIG. The present embodiment is different from the above-mentioned embodiment only in the part of the incomplete combustion detection operation, and the other configurations are the same. Hereinafter, detailed description of the same configurations will be omitted.

Referring to FIG. 5, in the present embodiment, when the combustion operation is started and the CO sensor 20 is activated as described above, first, the incomplete combustion determination means 24 of the controller 21 (see FIG. 2). ) Built-in 1-minute timer (not shown)
Is started. Then, the incomplete combustion determination means 24
Is the CO sensor 2 during the period from the start of the 1-minute timer to the time-up (until 1 minute elapses).
The CO values sequentially detected by 0 are integrated (cumulative addition), and the integrated value is sequentially compared with a predetermined determination value. Here, the integrated value corresponds to the total amount of unburned gas such as CO generated after the 1-minute timer is started,
The determination value is, for example, 200 corresponding to an incomplete combustion state.
The total gas amount value (2000 ppm × 1 minute) when 0 ppm of unburned gas is continuously generated for 1 minute is set. Therefore, an incomplete combustion state is temporarily generated by the wind and the like, and CO
When the value temporarily increases, the integrated value generally does not exceed the determination value within the timer time of the 1-minute timer, while the integrated value is blocked due to the blockage of the discharge port 6 or the like. When the incomplete combustion state occurs continuously, the integrated value exceeds the determination value within the timer time of the 1-minute timer.

If the integrated value becomes equal to or more than the judgment value during the operation of the one-minute timer, the incomplete combustion judgment means 24 is the combustion control means 2 just as in the above-mentioned embodiment.
2 (see FIG. 2) is operated to stop the combustion operation.
If the integrated value does not reach the judgment value during the operation of the 1-minute timer, the integrated value is cleared once and
The minute timer is restarted, the CO value is integrated again, and it is repeatedly monitored whether the integrated value is equal to or more than the determination value.

When the integrated value exceeds the judgment value and the combustion operation is stopped, the gas change detecting means 25 detects the temporal decrease rate of the CO value in exactly the same manner as in the above-mentioned embodiment. To be done. Then, when the temporal decrease rate is larger than a predetermined value, that is, when the combustion operation is stopped due to incomplete combustion that has continued to some extent due to continuous wind or the like, it is possible to restart the combustion operation. (Flag =
0), if the temporal decrease rate is less than a predetermined value, that is, if the combustion operation is stopped due to continuous incomplete combustion due to the blockage of the discharge port 6 (see FIG. 1), etc. Resuming operation is disabled (Flag = 1).

Therefore, also in this embodiment, when the incomplete combustion occurs due to the blockage of the exhaust port 6 and the combustion operation is stopped, the subsequent combustion operation is prohibited, and the combustion operation is continued in such a state. It is possible to reliably avoid a situation where driving is performed.

Further, when there is no clogging of the discharge port 6 or the like and continuous incomplete combustion occurs due to continuous wind to some extent and the combustion operation is stopped, the combustion operation is performed without any trouble. Can be restarted, and when a temporary incomplete combustion occurs due to a temporary wind or the like, the combustion operation continues without stopping.

The present invention is not limited to the above embodiments, but can be modified as appropriate without departing from the scope of the present invention. For example, in the present embodiment, a water heater has been described as an example of a combustion device, but it is needless to say that the present invention can be applied to a combustion device such as a fan heater.

In the embodiment described above, when the combustion operation is stopped, the CO value continues to be the predetermined judgment value or more for the predetermined timer time, or the CO value is integrated within the predetermined time. Although the combustion operation is stopped when the value exceeds the predetermined judgment value, the present invention is also applicable to the case where the combustion operation is stopped when the CO value exceeds the predetermined judgment value corresponding to incomplete combustion. Of course, the invention can be applied.

[0040]

As is apparent from the above description, according to the present invention, the temporal change rate of the output of the unburned gas sensor is detected by the gas change detecting means after the combustion operation is stopped in the case of incomplete combustion, When the temporal decrease rate is less than or equal to a predetermined value, restarting the combustion device is disabled, and when the temporal decrease rate is greater than the predetermined value, the combustion device can be restarted by a predetermined operation. With such a configuration, when incomplete combustion due to blockage of the exhaust passage or the like occurs, it is possible to reliably avoid a situation where the combustion operation is performed in such a state, and When incomplete combustion occurs due to wind or the like, the combustion operation can be restarted without any trouble, and therefore a combustion device capable of performing an appropriate operation operation according to the situation of occurrence of incomplete combustion is provided. Can Kill.

When the combustion operation is stopped, the combustion operation is stopped when the output of the unburned gas sensor continues for a predetermined time and becomes a predetermined judgment value or more, or the output of the unburned gas sensor is integrated within the predetermined time. By stopping the combustion operation when the integrated output value exceeds the predetermined judgment value, the accidental stop in the case of temporary incomplete combustion due to wind etc. is prevented and the combustion operation is continued. It is possible to provide a combustion device having excellent usability.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of a water heater to which an embodiment of the present invention is applied.

FIG. 2 is a block diagram of a main part of FIG. 1;

FIG. 3 is a flowchart for explaining the operation of the water heater of FIG. 1;

FIG. 4 is a flowchart for explaining the operation of the water heater of FIG. 1;

FIG. 5 is a flow chart for explaining the operation of another embodiment of the present invention.

[Explanation of symbols]

20 ... CO sensor (unburned gas sensor), 22 ... Combustion control means (operation control means), 24 ... Incomplete combustion determination means, 2
5 ... Gas change detection means.

Claims (3)

(57) [Claims] 1. An unburned gas sensor provided in an exhaust passage communicating with a combustion section, and an incomplete combustion that outputs a combustion operation stop command when an output of the unburned gas sensor satisfies a predetermined incomplete combustion determination standard. In a combustion device including a determination means and an operation control means for stopping the combustion operation in response to a combustion operation stop command of the incomplete combustion determination means, an output of the unburned gas sensor after the combustion operation is stopped by the operation control means Of the unburnt gas sensor detected by the gas change detection means, the temporal decrease rate of the output of the unburned gas sensor is less than or equal to a predetermined value. When the combustion device is not restartable, the combustion device is restarted by a predetermined operation when the temporal decrease rate is larger than the predetermined value. Burning appliance, characterized in that there. 2. The incomplete combustion determination means outputs the combustion operation stop command when the output of the unburned gas sensor continues for a predetermined time and becomes a predetermined determination value or more. Combustion equipment according to 1. 3. The incomplete combustion determination means outputs the combustion operation stop command when an integrated output value obtained by integrating the outputs of the unburned gas sensor within a predetermined time is equal to or greater than a predetermined determination value. The combustion device according to claim 1, wherein