JP2694890B2 - Combustion stopping device for incomplete combustion of 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 combustion stop device for incomplete combustion of combustion equipment, and more particularly to a combustion stop device for incomplete combustion using a CO sensor in a gas water heater.

[0002]

2. Description of the Related Art Conventionally, in this type of apparatus, a CO sensor is provided in an exhaust passage connected to a combustion chamber of a gas water heater.
The incomplete combustion state is detected by the output of the CO sensor, and the combustion is stopped accordingly. If a strong wind is blown into the combustion chamber during use of the gas water heater, the supply of air into the combustion chamber is hindered, the CO concentration temporarily rises, and a temporary incomplete combustion state occurs. However, the CO sensor does not distinguish between an incomplete combustion state due to such a temporary increase in CO concentration and a dangerous continuous incomplete combustion state such as blockage of an exhaust passage or an air supply passage. To detect
There is an inconvenience that the combustion is stopped when it is not necessary to stop the combustion.

When the amount of combustion in the combustion chamber changes depending on the state of use, the state of incomplete combustion was present when the amount of combustion was large, but when the amount of combustion decreases, the incomplete combustion state is temporarily eliminated. In such a case, there is a disadvantage that the incomplete combustion state cannot be properly detected and combustion is continued.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate such inconvenience, and it is possible to eliminate a malfunction due to a temporary incomplete combustion state due to the influence of wind or the like, and to prevent a dangerous incomplete combustion state. It is an object of the present invention to provide a combustion stop device for incomplete combustion that operates properly at times.

[0005]

In order to achieve such an object, the present invention provides an incomplete combustion detecting means for detecting incomplete combustion in a combustion section, and an incomplete combustion state based on an output of the incomplete combustion detecting means. In a combustion device including a determination unit that determines whether or not the combustion unit stops combustion by the determination of the determination unit, the determination unit outputs a determination value indicating an incomplete combustion state and the output of the detection unit. And a determination value changing unit that changes the determination value according to the combustion amount of the combustion unit after the output of the detection unit exceeds the determination value once. Is determined to be an incomplete combustion state when the state in which the output is equal to or greater than the determination value continues for a predetermined time or longer.

[0006]

According to the present invention, the output of the incomplete combustion detecting means is constantly compared with the comparing means of the judging means to determine whether or not the value is equal to or more than the judgment value. It is determined that The predetermined time is usually set to be equal to or longer than the duration of the temporarily generated strong wind, so that the combustion unit is not stopped at the time of temporary incomplete combustion due to strong wind or the like.

Further, according to the present invention, after the output of the incomplete combustion detection means exceeds the judgment value once, the judgment value of the judgment means is changed according to the combustion amount of the combustion section. Due to the fact that the incomplete combustion state is eliminated due to the temporary decrease in the amount of combustion, the combustion does not continue.

[0008]

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 cross-sectional view of a water heater provided with a combustion stop device according to an embodiment of the present invention, FIG. 2 is an explanatory view showing the configuration of the present embodiment, and FIG. 3 is a basic illustration of the operation of the present embodiment. FIG. 4 is a flow chart for explaining the determination operation of the incomplete combustion state according to the present embodiment, and FIGS. 5 and 6 are explanatory diagrams for the determination state of the incomplete combustion.

As shown in FIG. 1, a forced combustion type gas water heater A includes a gas burner 2 for performing combustion in a combustion housing 1.
And the blower fan 3 supplies the combustion air X for the gas burner 2 to the combustion housing 1. In addition, water heater A
The combustion control device 4 supplies gas to the gas burner 2, ignites the gas burner 2, and controls the blower fan 3. The combustion housing 1 is provided with an inlet (not shown) for the combustion air X below and a discharge port 6 for discharging the combustion exhaust gas Z to the outside above. Further, a heat exchanger 7 is disposed above the gas burner 2 in the combustion housing 1. The gas burner 2 includes a burner group 8 that forms a flame, and a nozzle pipe 10 that is located below the burner group 8 and that has an ejection port 9. Further, 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 2.
0 and a controller 21 for controlling them.

The combustion stopping device of the present invention is a CO sensor 20.
And a controller 21. Controller 2
1 is a microcomputer including a combustion control unit 22, a CO sensor control unit 23, and an incomplete combustion determination unit 24. As shown in FIG. 2, the incomplete combustion determination means 24 is
A comparison unit 26 that compares the output value of the CO sensor 20 with a predetermined determination value, a detection timer unit 27, and a determination value changing unit 28 that changes the determination value according to the combustion amount of the burner group 8 are provided.

Next, the basic operation of the controller 21 will be described. The controller 21 detects the open state of the hot water supply tap (not shown) by the water amount sensor 13, and controls the combustion control means 22 to open the original gas solenoid valve 15, the main solenoid valve 16, and the proportional solenoid valve 17. Then, the fuel gas is supplied to the gas burner 2, the blower fan 3 is driven, and the gas burner 2
Ignite and burn. When the hot water tap is closed, the controller 21 detects this with the water amount sensor 13 and controls the combustion control means 22 to close the original gas solenoid valve 15, the main solenoid valve 16, and the proportional solenoid valve 17. , The blower fan 3 is stopped and the gas burner 2 is extinguished. When the ignition of the gas burner 2 is completed, the controller 21 causes the CO sensor control means 23 to start the operation of the CO sensor 20, and when the CO sensor 20 detects the CO concentration according to a predetermined reference during the combustion of the gas burner 2, the controller 21 fails. The combustion control means 22 is operated by the complete combustion determination means 24,
The original gas solenoid valve 15, the main solenoid valve 16, and the proportional solenoid valve 17 are controlled to be closed, the blower fan 3 is stopped to be driven to extinguish the gas burner 2, and the CO sensor control means 23 controls the CO
The operation of the sensor 20 is stopped. The operation of the CO sensor 20 may be started at the time when the ON signal is output from the water amount sensor 13 or at a time when a predetermined time has elapsed after the flame detection.

Further, the combustion stopping operation at the time of incomplete combustion will be described with reference to FIG. The operation switch is turned on,
When the hot water tap is opened and the combustion fan 3 is driven, the source gas solenoid valve 15, the main solenoid valve 16, and the proportional valve 17 for supplying the fuel gas are opened with the ON operation of the igniter 18 to open the burner group 8 Is ignited, and after completion of ignition is detected by the flame rod 19, the igniter 18 is turned off, combustion is continued, and the combustion amount is controlled by the proportional valve 17. After the ignition of the burner group 8 is completed, the CO sensor 20 is turned on by the CO sensor control means 23 to detect the combustion state. After that, when the incomplete combustion determination means 24 determines the incomplete combustion state from the output of the CO sensor 20 as described later, as described above, the combustion control means 22.
To stop the combustion.

Next, the operation of determining the incomplete combustion state in this embodiment will be described with reference to FIG. When the CO sensor 20 is turned on, its output is compared with the initial judgment value (level) set by the judgment value changing means 28 by the comparing means 26. When this is equal to or more than the initial judgment value (level), the detection timer means 27 starts. Next, the judgment value changing means 28 continuously changes the judgment value (level) according to the output from the current value of the proportional valve 17 of the combustion control means 22 according to the supply amount of the fuel gas, and the judgment value (level) is changed. Is input to the comparison means 26, and thereafter, the output of the CO sensor 20 is compared based on the changing determination value (level). When the output of the CO sensor 20 is equal to or higher than the determination value (level) until the end of the timer operation time t of the detection timer means 27, the combustion control means 22 performs the combustion stop operation as the incomplete combustion state. Then, in order to inform the user that this combustion stop is due to incomplete combustion, an error is displayed to let the user understand the need for maintenance. However, while the detection timer means 27 is operating,
When the output of the CO sensor 20 becomes equal to or lower than the determination value (level), the operation of the detection timer means 27 is stopped and the above-described operation is repeated.

FIG. 5 is an explanatory view of a determination state of incomplete combustion in a state where the combustion amount is constant, that is, a state in which the determination value (level) is not changed. As shown in c, when the exhaust passage is blocked. As described above, when the output of the CO sensor 20 exceeds the determination value (level) once and then this state continues until the timer operation time t ends, it is determined that the combustion state is incomplete. However, as in the case of d, when it becomes equal to or lower than the determination value (level) of the CO sensor 20 during the timer operation time t, it is determined that the temporary incomplete combustion state is not determined as the incomplete combustion state. As a result, the combustion is not stopped when the incomplete combustion state is temporarily caused by the influence of strong wind or the like.

FIG. 6 is an explanatory diagram of a state in which the amount of combustion changes during combustion, that is, a state of determination of incomplete combustion when the determination value (level) is changed midway. Even if the amount of combustion changes during the operation time t, which temporarily lowers the initial determination value (level) or less, the determination value (level) changes according to the amount of combustion. The incomplete combustion state can be detected regardless of such a change in the combustion amount.

The present invention is not limited to the above embodiments, but can be modified as appropriate without departing from the gist of the present invention.

[0017]

As is apparent from the above description, according to the present invention, it is possible to prevent the combustion from being unnecessarily stopped when the incomplete combustion state is temporarily generated due to the influence of strong wind or the like. Further, due to the reduction of the combustion amount, it is possible to surely stop the combustion without erroneously determining the complete combustion state and continuing the combustion despite the originally incomplete combustion state. .

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of a water heater provided with a combustion stop device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the configuration of the present embodiment.

FIG. 3 is a basic flowchart illustrating the operation of the present embodiment.

FIG. 4 is a flow chart diagram for explaining an incomplete combustion state determination operation according to the present embodiment.

FIG. 5 is an explanatory diagram of a determination state of incomplete combustion.

FIG. 6 is an explanatory diagram of a determination state of incomplete combustion.

[Explanation of symbols]

8 ... Combustion part (burner group), 20 ... Incomplete combustion detection means (CO sensor), 22 ... Combustion control means, 24
..Incomplete combustion determination means, 26 .. Comparison means, 28 ..
Judgment value changing means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-5-26438 (JP, A) Actually open 63-49165 (JP, U) Actually open 6-46164 (JP, U)

Claims (1)

(57) [Claims] 1. An incomplete combustion detecting means for detecting incomplete combustion of a combustion part, a judging means for judging an incomplete combustion state based on an output of the incomplete combustion detecting means, and a judging means for judging the incomplete combustion state of the combustion part. In a combustion device including combustion control means for stopping combustion, the determination means indicates an incomplete combustion state.
Comparison means for constantly comparing the judgment value with the output of the detection means
And once the output of the detection means exceeds the judgment value,
A judgment value for changing the judgment value according to the combustion amount of the combustion section
Change means, and the output of the detection means is a judgment value or more
Incomplete combustion state when a certain state continues for a predetermined time or longer
Combustion stop device for incomplete combustion of combustion equipment, characterized by determining that