JP3475091B2 - Combustion equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention performs a process of stopping combustion of a burner by closing a fuel supply passage for supplying fuel to the burner when an exhaust port of combustion exhaust gas of the burner is clogged. It relates to a combustion device.

[0002]

2. Description of the Related Art As a combustion apparatus, for example, in a gas water heater that exhausts air indoors, fuel is supplied to the burner when the burner is in an incomplete combustion state in order to prevent air pollution in the room. A process of closing the on-off valve provided in the fuel supply passage for stopping the combustion of the burner is performed.

In this type of gas water heater, in order to detect the combustion state of the burner, a thermocouple that is heated by the combustion flame of the burner to generate an electromotive force is provided. When the voltage generated by the electromotive force of the thermocouple falls below a predetermined voltage, it is determined that incomplete combustion of the burner has occurred.

Further, the gas water heater is provided with an exhaust port for the combustion exhaust gas in order to efficiently discharge the combustion exhaust gas from the burner. However, as the gas water heater is used for a longer period of time,
There is a possibility that combustion products and dust adhering to the fins of the heat exchanger increase, the exhaust port is gradually closed, the combustion exhaust gas is not normally discharged, and incomplete combustion of the burner occurs.

Therefore, a thermocouple for detecting the temperature is also provided near the exhaust port of the burner, and the thermocouple (hereinafter referred to as the first thermocouple) and the combustion flame of the burner described above are heated to generate an electromotive force. A thermocouple (hereinafter referred to as a second thermocouple) is connected in series with opposite polarities to each other in series to form a series circuit, and the output voltage of the series circuit causes incomplete combustion caused by oxygen deficiency or the like and blockage of an exhaust port. There is known a gas water heater which detects incomplete combustion. By configuring the series circuit in this way, it is possible to detect, in the output of the series circuit, two abnormal states, that is, incomplete combustion caused by oxygen deficiency or the like and incomplete combustion caused by blockage of the exhaust port. The circuit configuration can be simplified.

Here, unless the exhaust port is closed, the temperature near the exhaust port does not rise so much, so that the electromotive force of the first thermocouple becomes substantially constant. At this time, when the burner is in an incomplete combustion state due to oxygen deficiency or the like, the flame of the burner is in a lift state, the thermoelectromotive force of the second thermocouple is reduced, and the output voltage of the series circuit is reduced.

On the other hand, when the exhaust port is closed, after the burner is ignited, the combustion exhaust gas of the burner having hot air is not discharged and stays near the exhaust port, so the temperature near the exhaust port rises and the 1 The electromotive force of the thermocouple increases, but if the exhaust port is blocked immediately after ignition of the burner (until the combustion air in the burner becomes insufficient due to the effects of combustion exhaust gas), the exhaust port will be blocked. Compared to when not doing
The electromotive force of the second thermocouple does not change, but the electromotive force of the first thermocouple increases. Then, as described above, since the first thermocouple and the second thermocouple are connected in opposite polarities to each other, the output voltage of the series circuit decreases even when the exhaust port is blocked.

That is, the output voltage of the series circuit is not limited to the case where the burner is in the incomplete combustion state due to oxygen deficiency or the like and the case where the exhaust port is closed and the burner is in the incomplete combustion state. Is reduced. The output voltage of the series circuit becomes lower when incomplete combustion of the burner occurs due to blockage of the exhaust port than when incomplete combustion of the burner occurs due to oxygen deficiency or the like. Therefore, in the gas water heater, incomplete combustion of the burner caused by oxygen deficiency or the like and incomplete combustion of the burner caused by blockage of the exhaust port are not particularly distinguished and detected, and the output voltage of the series circuit is When the incomplete combustion of the burner due to lack of oxygen or the like falls below the reference voltage, the on-off valve is closed to stop the combustion of the burner.

[0009]

As described above, in the conventional gas water heater, the incomplete combustion of the burner caused by oxygen deficiency or the like and the incomplete combustion caused by the blockage of the exhaust port are distinguished and detected. Didn't. However, the coping method to be performed by the user differs depending on whether incomplete combustion of the burner occurs due to lack of oxygen or the like and when incomplete combustion of the burner occurs due to blockage of the exhaust port.

That is, when the burner is incompletely burned due to oxygen deficiency or the like, the oxygen concentration in the indoor air, which is the combustion air for the burner, is reduced, so that the user must not ventilate the room. You can re-ignite the burner after doing. On the other hand, when incomplete combustion occurs due to the blockage of the exhaust port, the user cannot solve the blockage by himself and must request a maintenance company or the like to clean the exhaust port.

In view of the above, the present invention prohibits re-ignition of the burner when the exhaust port is clogged and prompts the user to request a maintenance company to clean the exhaust port. The purpose is to provide a device.

[0012]

To achieve the above object, the present invention provides a burner, an on-off valve for opening and closing a fuel supply passage for supplying fuel to the burner, an ignition means for igniting the burner, The temperature detection means provided near the exhaust port of the combustion exhaust gas of the burner, and the temperature detected by the temperature detection means after the first predetermined time has elapsed from the ignition of the burner by the ignition means are above a predetermined temperature. When it is determined that the exhaust port is in the closed state, the re-ignition inhibiting means for inhibiting the re-ignition of the burner by holding the on-off valve closed thereafter, and the combustion state of the burner are detected. Burning
State detection means and ignition of the burner by the ignition means
The second predetermined time longer than the first predetermined time has elapsed
After burning, the burner is not
When all combustion is detected, the on-off valve is closed to
And incomplete combustion stopping means for stopping the fuel supply to the burner .

When the exhaust port is blocked, it cannot be handled by a general user, and it is necessary to request a maintenance company to clean the exhaust port. Therefore, when the re-ignition inhibiting means of the present invention determines from the temperature detected by the temperature detecting means that the exhaust port is in the closed state, the re-ignition prohibiting means thereafter keeps the on-off valve closed and resets the burner. Ignition is prohibited to disable the user's ignition operation of the burner. As a result, the user can be urged to ask a maintenance company to clean the exhaust port and to eliminate the closed state of the exhaust port.

[0014]

Further, when the incomplete combustion of the burner due to blockage of the exhaust port and the incomplete combustion of the burner by the oxygen deficiency or the like occurs at the same time, prior to the incomplete combustion stop means the reignition prohibiting means When incompletely combusted, the incomplete combustion stopping means detects incomplete combustion of the burner, closes the on-off valve, and stops combustion of the burner. Then, at this time, the operation of the entire combustion apparatus is stopped, so that the re-ignition inhibiting means does not operate thereafter, and there is an inconvenience that the blockage of the exhaust port is not detected.

Therefore, in the incomplete combustion stopping means of the present invention, the second predetermined time which is longer than the first predetermined time from the ignition of the burner to the detection of the blockage of the exhaust port by the re-ignition prohibiting means is performed. After the elapse, the incomplete combustion of the burner is detected. As a result, after ignition of the burner, the re-ignition inhibiting means operates before the incomplete combustion stopping means. Therefore, when incomplete combustion of the burner due to oxygen deficiency or the like and incomplete combustion due to blockage of the exhaust port occur, blockage of the exhaust port is detected by the re-ignition prohibiting means, and re-ignition of the burner is performed. You can definitely prohibit it.

Further, a first thermocouple is used as the temperature detecting means, and a second thermocouple provided so as to generate an electromotive force due to the combustion flame of the burner is used as the combustion state detecting means. Forming a series circuit in which a pair and the second thermocouple are connected in series with opposite polarities to each other, and the re-ignition inhibiting means has a first reference in which an output voltage of the series circuit is set according to the predetermined temperature. When the voltage becomes equal to or lower than the voltage, it is determined that the exhaust port is in the closed state, and the incomplete combustion stopping unit causes the output voltage of the series circuit to become equal to or lower than the second reference voltage which is higher than the first reference voltage. It is characterized in that the burner is judged to be in an incomplete combustion state.

According to the present invention, the series circuit is constructed, and two abnormal states, that is, incomplete combustion due to blockage of the exhaust port and incomplete combustion of the burner due to oxygen deficiency or the like are detected by the output of the series circuit. , Adopts an abnormality detection circuit with a simplified configuration. As will be described later in detail, the output voltage of the series circuit is lower when the incomplete combustion due to the blockage of the exhaust port occurs than when the incomplete combustion of the burner due to lack of oxygen or the like occurs. The second reference voltage for detecting complete combustion is set to a voltage higher than the first reference voltage for detecting blockage.

Therefore, if the incomplete combustion stopping means is operated before the re-ignition inhibiting means after the burner is ignited, the output voltage of the series circuit is actually increased due to the blockage of the exhaust port. Before reaching the 1 reference voltage, the second
When the voltage becomes equal to or lower than the reference voltage, the incomplete combustion stopping means detects that incomplete combustion of the burner has occurred due to oxygen deficiency or the like, and incomplete combustion of the burner due to blockage of the exhaust port is not detected. There is an inconvenience.

Therefore, in the present invention, as described above, the re-ignition inhibiting means is operated prior to the incomplete combustion stopping means after the ignition of the burner. As a result, when the exhaust port is blocked and the output voltage of the series circuit becomes equal to or lower than the first reference voltage, the reignition of the burner can be reliably inhibited by the reignition inhibiting means. .

Further, there is provided reignition prohibition canceling means for canceling a state where the reignition of the burner is prohibited by the reignition prohibiting means and enabling reignition of the burner.

According to the present invention, the maintenance company who has finished cleaning the closed exhaust port can use the combustion device by releasing the re-ignition inhibition state of the burner by the re-ignition inhibition releasing means. It can be easily returned to the state.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described with reference to FIGS. 1 is an overall configuration diagram of a gas water heater which is a combustion apparatus of the present invention, FIG. 2 is a control block diagram of the gas water heater, and FIG. 3 is a voltage generated by an electromotive force of a thermocouple provided in the gas water heater. Level diagram, Figure 4,
5 is a flow chart showing the operation of the gas water heater.

Referring to FIG. 1, a gas water heater 1 according to a first embodiment of the present invention comprises a hot water supply pipe 2 through which hot water or water flows, and a gas burner 3 for heating water passing through the hot water supply pipe 2 (the present invention). (Corresponding to the burner of the present invention), a gas pipe 4 for supplying the fuel gas to the gas burner 3 (corresponding to the fuel supply passage of the present invention), a controller 5 for controlling the hot water supply operation, and an igniter electrode 6 for igniting the gas burner 3 ( (Corresponding to ignition means of the present invention), frame rod electrode 7 for detecting combustion flame of gas burner 3, first thermocouple 9 provided in the vicinity of exhaust port 8 (corresponding to temperature detecting means of the present invention), gas burner 3 The second thermocouple 10 (corresponding to the combustion state detecting means of the present invention) that generates an electromotive force by the combustion flame of No. 1 and the operation switch 11 that is pressed at the start and stop of the operation.

The hot water supply pipe 2 includes a water supply pipe 12, a heat absorbing pipe 13,
And the hot water outlet pipe 14. The water supply pipe 12 is provided with a faucet 15, a water governor valve 16, and a water amount control valve 17. The faucet 15 includes a faucet motor 18 and a position detection switch (not shown). When the faucet motor 18 is energized (ON), the faucet motor is switched between an open position and a closed position. The water governor valve 16 keeps the amount of water supplied constant. The water amount control valve 17 controls the opening degree of the water supply pipe 12 according to the operation of the temperature control knob 19 to change the water supply amount.

The endothermic tube 13 is a heat exchanger that is provided above the gas burner 3 with fins 20 and heats the water passing through the inside by the combustion heat of the gas burner 3. Hot water pipe 1
Reference numeral 4 denotes a flexible tube, which discharges hot water or water through the shower head 21. The shower head 2
Reference numeral 1 indicates that the changeover switch 22 can switch the form of hot water or water to be showered or straight. The temperature control knob 19 is, as described later,
A hot water / water changeover switch 23 (see FIG. 2) is provided, and when the temperature control knob 19 is moved to the lowest temperature position, the hot water / water changeover switch 23 is turned on, the gas burner 3 is not ignited, and the shower head 21 Water is discharged from.

The gas pipeline 4 is a safety valve 2 which is an electromagnetic on-off valve.
4 (corresponding to the on-off valve of the present invention), a water pressure responsive valve 25, a gas governor valve 26, and a gas amount control valve 27.
The safety valve 24, which will be described in detail in a second embodiment to be described later, opens when the solenoid coil is energized to open the gas pipeline 4, and closes when energization to the solenoid coil is stopped. Line 4 is closed. The water pressure responsive valve 25 is formed integrally with the water governor valve 16, and opens when the water flow is detected by the water governor valve 16 in conjunction with it. A water flow switch 28 is connected to the water pressure responsive valve 25.

The water flow switch 28 is turned on when the water pressure responsive valve 25 is opened, and is turned off when the water pressure responsive valve 25 is closed. The gas governor valve 26 keeps the gas pressure on the secondary side constant. The gas amount control valve 27 is connected to the temperature control knob 19 and controls the opening degree of the gas pipeline 4 by operating the temperature control knob 19 to change the supply amount of the fuel gas. The amount of water decreases and the amount of gas increases as the temperature control knob 19 is operated to the higher temperature side.

As shown in FIG. 2, the controller 5 includes a microcomputer 30, a motor drive circuit 31 for driving the faucet motor 18, an igniter drive circuit 32 for driving the igniter electrode 6, and a safety valve drive circuit 33 for driving the safety valve 24. A frame rod circuit 34 for operating the frame rod electrode 7, an amplifier circuit 35 for the first thermocouple 9 and the second thermocouple 10, and the like. Reference numeral 36 shown in FIG. 1 denotes a power supply battery, which is used as a power supply for operating the controller 5, the safety valve 24, the faucet motor 18, and the like.

As shown in FIG. 2, the microcomputer 30 includes an operation controller 37, a water controller 38, and a combustion controller 3.
9, and a combustion amount detection unit 40.

When the operation switch 11 is turned on while the hot water supply is stopped (the water faucet 15 shown in FIG. 1 is closed), the operation control unit 37 operates the water faucet 15 via the water control unit 38. Fully open. At this time, the water control unit 38 energizes the water faucet motor 18 via the motor drive circuit 31 to operate the water faucet motor 18 until the water faucet 15 is fully opened. The water faucet motor 18 detects the fully opened state of the water faucet 15 by the water faucet switch 41 and stops the operation. In addition, the operation control unit 3
7 controls the operation of the igniter electrode 6 and the safety valve 24 via the combustion control unit 39 when the water flow switch 28 is ON (water flow detection is detected) and the hot water / water changeover switch 23 is OFF (hot water side). Ignition processing of the burner 3 is performed.

The combustion control unit 39 uses the flame rod circuit 3
The flame detector 42 for detecting the presence or absence of the combustion flame of the burner 3 based on the output of the burner 3 and the output voltage of the series circuit 43 in which the first thermocouple 9 and the second thermocouple 10 are connected in series with opposite polarities (the amplifier circuit 3
5)), incomplete combustion stopping means 44 for detecting incomplete combustion of the burner 3, and reignition prohibiting means 45 for detecting blockage of the exhaust port 8 based on the output voltage of the series circuit 43, And a switching unit 47 for switching the operation of the flame detection unit 42, the incomplete combustion stopping unit 44, and the reignition inhibiting unit 45 according to the elapsed time from the start of the operation of the igniter drive circuit 32, which is timed by the timer 46. There is.

The combustion control unit 39 uses the switching unit 47 to detect the combustion flame of the burner 3 by the flame detection unit 42 for a first predetermined time (30 seconds in this embodiment) from the start of the operation of the igniter drive circuit 32. Until the second predetermined time (33 seconds in the present embodiment) elapses after the first predetermined time (30 seconds) elapses, the re-ignition prohibiting means 45 detects the closed state of the exhaust port 8, After the lapse of 2 predetermined times, the detection of the incomplete combustion of the burner 3 by the incomplete combustion stopping means 44 is switched and executed.

If the combustion flame of the burner 3 cannot be detected by the flame detector 42, the incomplete combustion stopping means 44
If the incomplete combustion of the burner 3 is detected by the above, and if the exhaust port 8 is blocked by the reignition prohibiting means 45, the safety valve 24 is closed via the safety valve drive circuit 33, and the burner 3 is closed. The supply of fuel gas is stopped.

The re-ignition inhibiting means 45 allows the exhaust port 8
Is detected, the safety valve closing and holding circuit 50 operates to forcibly hold the safety valve 24 in the closed state, and thereafter the ignition of the burner 3 is prohibited.

Further, the combustion control section 39 includes a flame detection section 42,
Based on the detection results of the incomplete combustion stopping means 44 and the re-ignition inhibiting means 45, the burner 3 is burning normally, and the exhaust port 8
Even when the blockage of the igniter is not occurring, the operation switch 1 is operated from the start of the operation of the igniter drive circuit 32 until the forgetting to turn off monitoring time (20 minutes in the present embodiment) elapses.
When the OFF operation (fire extinguishing operation) of 1 is not performed, it is judged that the user forgets to turn off the gas, and immediately the safety valve 24 is closed via the safety valve drive circuit 33 to stop the combustion of the burner 3 and the forgetting prevention means 48. Is equipped with. In the present embodiment, the forgotten erasure monitoring time is constant (20 minutes), but the forgotten erasure monitoring time is calculated based on the combustion amount detected by the combustion amount detecting unit 40, which will be described later. It may be set separately such as 20 minutes when the amount is small and 15 minutes when the amount of combustion is large.

The combustion amount detector 40 detects the target combustion amount of the gas burner 3 according to the setting position of the temperature control knob 19,
It is determined whether the gas burner 3 is burning in the weak combustion amount region or in the strong combustion amount region.

Next, referring to FIGS. 3A and 3B, the incomplete combustion stopping means 4 based on the output voltage of the series circuit 43.
A process of detecting incomplete combustion of the gas burner 3 by the No. 4 and a process of detecting the blockage of the exhaust port 8 by the reignition prohibiting means 45 will be described.

As shown in FIG. 3A, the first thermocouple 9
And the second thermocouple 10 are connected in series with opposite polarities. When the exhaust port 8 is not closed, the first thermocouple 9
Since the voltage V ₁ generated by the electromotive force of the second thermocouple does not change, the output voltage V _OUT of the series circuit 43 changes according to the voltage V ₂ generated by the electromotive force of the second thermocouple. Then, when the incomplete combustion of the gas burner 3 occurs, the electromotive force of the second thermocouple 10 becomes weaker than that in the normal combustion due to the lift of the combustion flame of the gas burner 3, and V ₂ decreases.

Therefore, as shown in FIG. 3B, when the gas burner 3 is in the incomplete combustion state (b in the figure) than when it is in the normal combustion state (a in the figure). , The output voltage V _OUT of the series circuit 43 after ignition
The rising level of will be lower. From this, the incomplete combustion stopping means 44 outputs the output voltage V of the series circuit 43 after the second predetermined time (33 seconds) has elapsed from the ignition of the gas burner 3.
_{When OUT} becomes 5 mV (corresponding to the second reference voltage of the present invention) or less, it is detected that the burner 3 is in the incomplete combustion state.

On the other hand, when the exhaust port 8 is closed,
Burned exhaust gas from the burner 3 with hot air is trapped near the exhaust port 8.
The temperature near the first thermocouple 9 rises due to
The electromotive force of the thermocouple 9 increases, and the output voltage V of the first thermocouple 9 increases.₁
Increases (in the negative direction). And at this time the burner 3
Since it burns normally, the output voltage V of the second thermocouple 10 ₂
Is no different from normal. Therefore, it is shown in c of Fig. 3 (b).
As described above, the output voltage V of the series circuit 43_OUTThe level of
descend. Therefore, the re-ignition inhibiting means 45 is
After the first predetermined time (30 seconds) has passed from the ignition of NA3
Until the second predetermined time (33 seconds) elapses (3 seconds)
To the output voltage V of the output circuit 43 of the series circuit 43_OUTBut-
3 mV (corresponding to the first reference voltage of the present invention) or less
When it is opened, it is detected that the exhaust port 8 is closed.

The first predetermined time (30 seconds) at this time
Is the time for stabilizing the outputs of the first thermocouple 9 and the second thermocouple 10.

Further, in this embodiment, the positive electrode of the first thermocouple 9 and the positive electrode of the second thermocouple 10 are connected to each other and the series circuit 43 is connected.
However, the series circuit 43 may be configured by connecting the negative electrode of the first thermocouple 9 and the negative electrode of the second thermocouple 10. In this case, the series circuit 4 is based on the positive electrode of the first thermocouple 9.
The output voltage of 3 may be detected.

Next, the operation of the gas water heater 1 will be described with reference to FIGS.
It will be described according to the flowchart shown in FIG.

Referring to the flowcharts of FIGS. 4 and 5 and FIGS. 1 and 2, the user operates the operation switch 11 in STEP 1.
When is turned on, the controller 5 starts operating. Then, in STEP 2, the water control unit 38 causes the faucet motor 18 via the motor drive circuit 31 according to an instruction from the operation control unit 37.
Is operated to open the water faucet 15, and in STEP 3, when the water flow switch 28 is turned on by the flow of water to the hot water supply pipe line 2, the process proceeds to STEP 4, and in STEP 4, the hot water / water changeover switch 23 is turned off (hot water side). When operated, ST
Proceeding to EP5, the ignition process of the burner 3 is started according to the instruction of the operation control unit 37. On the other hand, the hot water / water changeover switch 23
Is turned on (water side), STEP20
However, the ignition process of the burner 3 is not performed and the shower head 21 discharges water.

In STEP5 to STEP9, the combustion control unit 3
It is the ignition process of the burner 3 by 9, and in STEP 5,
The igniter drive circuit 32 is turned on according to an instruction from the combustion control unit 39, and spark discharge for igniting the burner 3 is generated in the igniter electrode 6. In STEP 6, the combustion control unit 39
The safety valve 24 is energized through the safety valve drive circuit 33 to keep the safety valve 24 open, and the fuel gas is supplied to the burner 3. In the subsequent STEP 7, the combustion control unit 3
9 supplies electric power for operation to the frame rod circuit 34,
The flame detection by the frame rod electrode 7 is made possible.

Next, at STEP 8, the combustion control unit 39 waits for 1.8 seconds and then turns off the igniter drive circuit 32 at STEP 9. As a result, the spark discharge of the igniter electrode 6 is stopped, and the ignition process of the burner 3 is completed. The combustion control unit 39, in STEP 11, the igniter drive circuit 32
After turning ON, 30 seconds elapse, STEP1
At 0, ignition of the burner 3 by the frame rod electrode 7 is detected via the flame detection unit 42.

When the ignition of the burner 3 is not detected in STEP 10, the process branches to STEP 17, the combustion control unit 39 closes the safety valve 24 via the safety valve drive circuit 33, and the operation of the controller 5 ends in STEP 18. To do.
On the other hand, when 30 seconds have passed from turning on the igniter drive circuit 32 in STEP 11,
Proceeding to P12, the frame rod circuit 34 is turned off.

In the subsequent STEP 13, reignition inhibiting means 45
It is a process by. The re-ignition inhibiting means 45 is STEP1.
3, the output voltage of the series circuit 43 is the first reference voltage (-3 m
V) or less, it is determined that the exhaust port 8 is in a closed state, and the process branches to STEP 30 to close the safety valve 24,
At STEP 31, the safety valve closing and holding circuit 50 is turned on. As a result, the safety valve 24 is forcibly held in the closed state,
After that, ignition of the burner 3 is prohibited. As a result, ignition of the burner 3 is prohibited when the exhaust port 8 is closed.

In this case, the user cannot use the gas water heater 1 unless the maintenance company or the like requests the repair of the gas water heater 1. Then, the maintenance company cleans the exhaust port 8 to eliminate the closed state, and thereafter operates the reignition prohibition releasing means 51 to operate the safety valve closing and holding circuit 5
0 is turned off. As a result, the safety valve closing holding circuit 50
The forced closed valve holding of the safety valve 24 due to is released, and the user can use the gas water heater 1 again.

When the re-ignition prohibition releasing means 51 is operated by the user, the re-ignition operation of the burner 3 becomes possible with the exhaust port 8 closed, so that the user does not have to exist. It is provided so that it cannot be recognized.

Further, as described above, the first reference voltage (-3 mV) for detecting the blockage of the exhaust port 8 is the second reference voltage (5 m for detecting the incomplete combustion of the gas burner 3).
Lower than V). Therefore, when the exhaust port 8 is blocked (when the output voltage of the series circuit 43 becomes the first reference voltage or lower), the output voltage of the series circuit 43 always becomes the second reference voltage or lower.

Therefore, after the ignition of the gas burner 3, the incomplete combustion stopping means 44 detects the incomplete combustion of the gas burner 3 caused by oxygen deficiency, etc.
If the detection is performed prior to the detection of incomplete combustion caused by the blockage of the exhaust port 8, the output voltage of the series circuit 43 will be the second reference voltage even if the exhaust port 8 is actually blocked. Because of the following, the on-off valve 24 is closed by the incomplete combustion stopping means 44 and the operation of the controller is stopped. In this case, the reignition prohibiting means 45 does not detect the blockage of the exhaust port 8, and the reignition of the burner 3 is not prohibited.

Therefore, as described above, the re-ignition inhibiting means 45 is provided.
Detection of incomplete combustion caused by the blockage of the exhaust port 8 by the incomplete combustion stop means 44 in STEP 15 described later.
Is performed prior to the detection of incomplete combustion of the burner 3 caused by oxygen deficiency, etc., and when the exhaust port 8 is blocked, the re-ignition prohibiting means 45 causes the safety valve closing and holding circuit 50.
Is operated to ensure that the subsequent re-ignition of the burner 3 is prohibited.

In the subsequent STEP 14, three seconds have elapsed after the frame rod circuit was turned off (STEP 12), that is, 33 seconds (corresponding to the second predetermined time of the present invention) from ON (STEP 5) of the igniter drive circuit 32. After the lapse of time, in STEP 15, the detection processing of the incomplete combustion of the burner 3 caused by oxygen deficiency or the like is started by the incomplete combustion stopping means 44.

The incomplete combustion stopping means 44 is a series circuit 43.
When the output voltage of the burner becomes lower than the second reference voltage (5 mV), it is determined that the burner 3 is in the incomplete combustion state, and the STE
Branch to P17. Then, the combustion control unit 39 closes the safety valve 24 via the safety valve drive circuit 33, and STEP1
The operation is finished at 8.

STEP 16 is a process by the forgetting to prevent erasing means 48, in which the igniter drive circuit 32 is turned on.
When 20 minutes have passed from the time (STEP 5), it is determined that the user has forgotten to extinguish the fire of the burner 3, and STEP
Proceeding to 17, the combustion control unit 39 closes the safety valve 24 via the safety valve drive circuit 33, and in STEP 18, the operation of the controller 5 ends.

Further, STEP 40 to STEP 42 are routines by interruption processing, and when the operation switch 11 is turned OFF while the burner 3 is burning, STEP 41 is executed.
The combustion control unit 39 transmits the safety valve 2 via the safety valve drive circuit 33.
4 is closed, and in STEP 42, the water control unit 38 closes the water faucet 15 by the water faucet motor 18 via the motor drive circuit 31, and the operation of the controller 5 ends.

Even if the operation of the controller 5 is completed,
The safety valve closing and holding circuit 50 continues to operate. for that reason,
During operation of the safety valve closing and holding circuit 50, the operation switch 11
Is turned on (ignition operation), and in STEP 6, even if the combustion control unit 39 tries to open the safety valve 24 via the safety valve drive circuit 33, the safety valve 24 does not open and fuel gas is not supplied to the burner 3. I can't. In this case, since the burner 3 is not ignited, the combustion flame is not detected in STEP 10, and the process branches to STEP 17 to end the operation of the controller 5.

Next, a second embodiment of the present invention will be described with reference to FIGS. 1, 2, and 6. In the gas water heater according to the second embodiment, the function of the microcomputer 30 configuring the controller 5 of the gas water heater 1 according to the first embodiment is realized by a control circuit configured by an electronic circuit. FIG. 6 is a block diagram of the control circuit. In FIG. 6, the same components as those shown in FIGS. 1 and 2 are designated by the same reference numerals and the description thereof will be omitted.

Referring to FIG. 6, control circuit 60 is ON when operation switch 11 is ON, water flow switch 28 is ON, and hot water / water changeover switch 23 is OFF (hot water side).
The operating condition switch 59 that is closed (closed) and the regulator circuit 6 that outputs a constant reference voltage from the output power of the battery 36
1, an igniter timer circuit 62 that counts a predetermined time from the ON operation of the operation condition switch 59, a solenoid valve suction timer circuit 63, a solenoid valve holding timer circuit 64, a frame rod timer circuit 65, a forget-to-delete timer circuit 66, and a first The thermocouple timer circuit 68, the first thermocouple circuit 75 that detects the blockage of the exhaust port 8 from the output voltage of the series circuit 43, and the incomplete combustion of the burner 3 that occurs due to oxygen deficiency or the like from the output voltage of the series circuit 43. The second thermocouple circuit 67 is provided.

When the user turns on the operation switch 11 (ignition operation) to turn on the operation condition switch 59, the igniter timer circuit 6 is passed through the regulator circuit 61.
2, power is supplied to the solenoid valve suction timer circuit 63, the solenoid valve holding timer circuit 64, the frame rod timer circuit 65, the forget-to-turn-off timer circuit 66, the second thermocouple circuit 67, and the first thermocouple timer circuit 68. , These circuits start operating.

The igniter timer circuit 62 continues to output a low level signal to the transistor 70 and turns on the transistor 70 until 1.8 seconds elapse after the operating condition switch 59 is turned on. Transistor 7
When 0 is turned on, the igniter circuit 32 operates and spark discharge is generated in the igniter electrode 6. After 1.8 seconds have elapsed, the igniter timer circuit 62 stops the output of the low level signal, stops the operation of the igniter drive circuit 32, and ends the spark discharge from the igniter electrode 6.

Although description of the safety valve 24 is omitted in the first embodiment, it is relatively necessary to move the safety valve 24 from the valve closing side to the valve opening side in order to suppress the power consumption when the valve is held open. A large electromagnetic force is generated, and a suction coil 71 that consumes a large amount of power and an electromagnetic force that is smaller than the suction coil 71 in order to maintain the valve open state after moving to the valve opening side,
The holding coil 72 has low power consumption. Thus, the suction coil 71 and the holding coil have two types of coils, and only when the safety valve 24 is moved to the opening side by overcoming the resistance of the spring (not shown) that biases the safety valve 24 to the closing side. After energizing both of the valves 72 to open the safety valve 24, the energization of the suction coil 71 is stopped and only the energization of the holding coil 72 is continued to maintain the open state of the safety valve 24. Thus, it is possible to suppress the power consumption when the safety valve 24 is held open.

The electromagnetic valve suction timer circuit 63 outputs a low level signal to the transistor 73 and outputs a low level signal to the transistor 7 until 0.4 seconds elapses after the operating condition switch 59 is turned on.
3 is turned on, and the suction coil 71 is energized. Further, the solenoid valve holding timer circuit 64 outputs a low level signal to the transistor 74 to turn on the transistor 74 and energize the holding coil 72 until 1.8 seconds have elapsed since the operating condition switch 59 was turned on. As a result, the operating condition switch 5
During 0.4 seconds from the time when 9 is turned on, both the suction coil 71 and the holding coil 72 are operated, the safety valve 24 is switched from the closed state to the open state, and 1.8 seconds have passed after 0.4 seconds have elapsed. Until elapses, only the holding coil 72 operates and the open state of the safety valve 24 is maintained.

The frame rod timer circuit 65 supplies operating power to the frame rod circuit 34 for 33 seconds after the operating condition switch 59 is turned on. The flame rod circuit 34 outputs a low level voltage to the base of the transistor 74 when the flame of the burner 3 is detected from the output of the flame rod electrode 7, and when the flame of the burner 3 is not detected (burner 3 When a fire goes off) transistor 74
Stop outputting low level signals to the base of the. That is, when the flame rod circuit 34 detects a misfire of the burner 3 within 33 seconds after the operating condition switch 59 is turned on, a low level signal from the frame rod circuit 34 to the base of the transistor 74 is detected. Is stopped, the energization of the holding coil 72 is stopped, and the safety valve 24 is closed.

The forget-to-turn-off timer circuit 66 is for forcibly closing the safety valve 24 to stop the combustion of the burner 3 when the user forgets to turn off the operation switch 11. The erase-forgotten timer circuit 66 outputs a high-level signal to the base of the transistor 74 and outputs the high-level signal to the transistor 7 when 20 minutes have passed since the operating condition switch 59 was turned on.
Turn off 4. As a result, the power supply to the holding coil 72 is cut off, the safety valve 24 is closed, and the combustion of the burner 3 is stopped.

The second thermocouple circuit 67 is for detecting incomplete combustion of the burner 3 caused by oxygen deficiency or the like,
It corresponds to the incomplete combustion stopping means of the present invention. In the second thermocouple circuit 67, the output voltage of the series circuit 43 is the first reference voltage (5
mV) or less (the burner 3 is in an incomplete combustion state), its output terminal is in a high impedance state, and when the output voltage of the series circuit 43 exceeds the first reference voltage (5 mV), a transistor is output from the output terminal. A low level signal is output to the base of 74.

If the flame of the burner 3 is detected by the operation of the flame rod timer circuit 65 as described above for 33 seconds after the operation condition switch 59 is turned on (even if the combustion is incomplete). ) The safety valve 24 is held open. Therefore, the second thermocouple circuit 67 functions effectively after 33 seconds have elapsed since the operating condition switch 59 was turned on. That is, when 33 seconds have passed after the operating condition switch 59 was turned on and incomplete combustion of the burner 3 due to oxygen deficiency or the like occurs, the low level signal output from the second thermocouple circuit 67 until then is stopped. Then transistor 7
4 is turned off, the energization of the holding coil 72 is cut off, and the safety valve 24 is closed.

The first thermocouple timer circuit 68 sets the first thermocouple timer circuit 68 when the operation condition switch 59 is turned on for 30 seconds.
The thermocouple circuit 75 is activated. The first thermocouple circuit 75,
By detecting the incomplete combustion caused by the blockage of the exhaust port 8, the blockage of the exhaust port 8 is detected, and corresponds to the re-ignition inhibiting means of the present invention. When the output voltage of the series circuit 43 is equal to or lower than the second reference voltage (−3 mV), the first thermocouple circuit 75 determines that the exhaust port 8 is in the closed state, and activates the reignition prohibition circuit 76. . If the output voltage of the series circuit 43 is equal to or lower than the second reference voltage (-3 mV) lower than the first reference voltage (5 mV), as described above, the low voltage is applied from the second thermocouple circuit 67 to the base of the transistor 74. Since the level signal is output, the safety valve 24 is closed and the combustion of the burner 3 is stopped.

The re-ignition inhibiting circuit 76 is a latch circuit,
When the operation is started by the operation signal from the first thermocouple circuit 75, the low level signal is continuously output to the base of the transistor 77 thereafter (until the reignition prohibition releasing means 51 described later is operated). Then, the re-ignition prohibition circuit 76
The operating power source of the operating condition switch 59 is supplied directly from the battery 36 without passing through the operating condition switch 59.
Even if is turned off, the low-level signal is continuously output from the re-ignition inhibiting circuit 76 to the base of the transistor 77.

Then, a low level signal is output from the re-ignition inhibiting circuit 76 to the transistor 77, and the transistor 7
When 7 turns on, the potential difference between the emitter and the base of the transistor 70 disappears, so the igniter timer circuit 62
Even if a low level signal is output from, the base current of the transistor 70 does not flow and the transistor 70 is kept in the OFF state.

Therefore, while the re-ignition inhibiting circuit 76 is in operation, the user turns on the operation switch 11 to turn on the operating condition switch 59, and even if the igniter timer circuit 62 operates, the igniter drive circuit 32 remains It does not operate, and no spark is generated on the igniter electrode 6. As a result, reignition of the burner 3 is prohibited when the exhaust port 8 is closed.

Here, when the exhaust port 8 is blocked, the user must request the maintenance company or the like to clean it, as described in the first embodiment. Then, the maintenance company who has finished cleaning the exhaust port 8 operates the re-ignition prohibition releasing means 51, whereby the output of the low voltage signal from the re-ignition prohibition circuit 76 to the base of the transistor 77 is stopped and the transistor 77 is turned off. To do. As a result, the igniter drive circuit 32 can be operated and the burner 3 can be ignited.

As described above, according to the second embodiment, the control processing by the microcomputer 30 described in the first embodiment can be realized by using the control circuit 60.

In the first and second embodiments, the output voltage of the series circuit 43 in which the first thermocouple 9 and the second thermocouple 10 are connected in series with mutually opposite polarities causes an oxygen deficiency or the like. Although the incomplete combustion of the burner 3 caused by the above and the incomplete combustion of the burner 3 caused by the blockage of the exhaust port 8 were detected, the first thermocouple 9 and the second thermocouple 10 were independently connected without being connected in series. The incomplete combustion of the burner 3 caused by oxygen deficiency or the like and the incomplete combustion of the burner 3 caused by blockage of the exhaust port may be separately detected from the voltage level generated by the electromotive force of each thermocouple. .

In this case, instead of a thermocouple, a thermistor, a platinum temperature measuring element or the like may be used as the temperature detecting means for detecting the temperature near the exhaust port 8. Further, as the combustion state detecting means for detecting the combustion state of the burner 3, a flame rod or the like may be used instead of the thermocouple. Then, in this way, temperature detecting means for detecting the temperature in the vicinity of the exhaust port 8,
Even when the combustion state detecting means for detecting the combustion state of the burner 3 is installed independently, the exhaust port 8 by the reignition inhibiting means is also provided.
Of the incomplete combustion caused by the exhaust port 8 by detecting the incomplete combustion of the burner 3 caused by the oxygen deficiency or the like by the incomplete combustion stopping means. When the incomplete combustion of the burner 3 due to lack or the like occurs at the same time, the reignition inhibiting means 45 can reliably inhibit the reignition of the burner 3.

Further, in the first and second embodiments, the gas water heater is explained as an example of the combustion apparatus. However, it can be applied to other types of combustion apparatuses such as a grill, a gas table and a heater. However, the present invention can be applied. Further, the fuel in these combustion devices is not limited to gas,
For example, it may be kerosene.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a gas water heater which is a combustion device of the present invention.

2 is a control block diagram of the gas water heater shown in FIG. 1. FIG.

FIG. 3 is an explanatory diagram of a voltage level generated by an electromotive force of a thermocouple.

FIG. 4 is a flowchart showing the operation of the gas water heater.

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

FIG. 6 is a circuit configuration diagram of a control circuit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Gas water heater (combustion device), 3 ... Gas burner, 4 ... Gas pipeline, 6 ... Igniter electrode, 7 ... Frame rod, 8
... Exhaust port, 9 ... First thermocouple, 10 ... Second thermocouple, 11 ...
Operation switch, 12 ... Water supply pipe, 13 ... Endothermic pipe, 14 ... Hot water pipe, 15 ... Faucet, 16 ... Water governor valve, 17 ... Water quantity control valve, 18 ... Faucet motor, 19 ... Temperature control knob, 20 ... Fin , 21 ... Shower head, 22 ... Changeover switch, 24
… Safety valve, 25… Water pressure responsive valve, 26… Gas governor valve, 2
7 ... Gas amount control valve, 28 ... Water flow switch, 30 ... Microcomputer, 31 ... Motor drive circuit, 32 ... Igniter drive circuit, 33 ... Safety valve drive circuit, 34 ... Frame rod circuit, 35 ... Amplification circuit, 37 ... Operation control Part, 38
... Water control unit, 39 ... Combustion control unit, 43 ... Series circuit, 44
... incomplete combustion stopping means, 45 ... reignition inhibiting means

Continuation of the front page (56) Reference JP-A-11-311412 (JP, A) JP-A-5-5520 (JP, A) JP-A-63-17312 (JP, A) JP-A-11-304144 (JP , A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) F23N 5/24 104 F23N 5/10 330 F23N 5/20 102

Claims (3)

(57) [Claims] 1. A burner, an on-off valve for opening and closing a fuel supply passage for supplying fuel to the burner, an ignition means for igniting the burner, and a temperature detecting means provided near an exhaust port of combustion exhaust gas of the burner. When the temperature detected by the temperature detecting means is equal to or higher than the predetermined temperature after the first predetermined time has elapsed from the ignition of the burner by the ignition means, it is determined that the exhaust port is in the closed state. Te, and relight inhibiting means for inhibiting the re-ignition of the burner and closed hold thereafter the on-off valve, a combustion condition detecting means for detecting the combustion state of the burner,
From the ignition of the burner by the ignition means,
After the second predetermined time, which is longer than the fixed time, has passed,
Incomplete combustion of the burner is detected by the burning state detection means.
The fuel to the burner by closing the on-off valve.
A combustion device comprising: an incomplete combustion stopping means for stopping the supply . 2. A first thermocouple is used as the temperature detecting means, and a second thermocouple provided so as to generate an electromotive force due to a combustion flame of the burner is used as the combustion state detecting means. Forming a series circuit in which a pair and the second thermocouple are connected in series with mutually opposite polarities, and the re-ignition inhibiting means is a first reference in which an output voltage of the series circuit is set according to the predetermined temperature. When the voltage becomes equal to or lower than the voltage, it is determined that the exhaust port is in the closed state, and the incomplete combustion stopping unit causes the output voltage of the series circuit to become equal to or lower than the second reference voltage which is higher than the first reference voltage. The combustion apparatus according to claim 1 , wherein the burner determines that the burner is in an incomplete combustion state. 3. Release the state in which reignition of the burner has been prohibited by the reignition prohibiting means, claims, characterized in that a re-ignition prohibition canceling means for enabling the re-ignition of the burner The combustion device according to claim 1 or claim 2 .