JP2744410B2 - Combustion device and combustion control method - 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 device and a combustion control method used for a hot water supply device or the like.

[0002]

2. Description of the Related Art A combustion device in a hot water supply device or the like includes a burner for burning fuel and a combustion fan for feeding air required for combustion into a combustion chamber in which the burner is installed or exhausting the air. That is, the burner is supplied with fuel gas required for combustion, and the combustion fan supplies air required for combustion. Then, the exhaust after the combustion is performed from the exhaust port according to the blowing of the combustion fan.

[0003]

However, in such a combustion apparatus, the performance of the combustion fan directly affects the combustion of the fuel, and when it is insufficient, it induces incomplete combustion and is dangerous. . Therefore, the combustion fan needs to be maintained in an optimal state, and maintenance and management are indispensable.

However, the combustion fan has a closed structure with respect to the combustion chamber in order to supply the taken outside air to the combustion chamber in which the burner is installed. Therefore, it is very troublesome for a user to disassemble the combustion fan from the combustion device and clean its wings and the like, and it is severe to require such work.

Therefore, a method of installing a CO sensor in the combustion chamber to monitor the CO concentration in the exhaust gas, increasing the rotation speed of the combustion fan in accordance with the detected output, and preventing a decrease in the amount of supplied air. Has been taken. JP-A-63-29420
No. "combustion device" is an example. Then, when the CO concentration exceeds a preset limit value, a method has been adopted in which a warning or display is performed to notify that the cleaning of the combustion fan or the like is necessary.

[0006] However, it is important to determine whether the blowing capacity of the combustion fan is appropriate in relation to the amount of fuel supplied or not, and it is known that the CO concentration value varies with the amount of fuel supplied. Have been. Since the CO concentration is directly related to the combustion state, the combustion state is determined based on the flame temperature and the like.
Although the concentration can be known, it is considered to be advantageous in that the combustion state can be directly known as compared with the indirect method.

[0007] Further, even when the exhaust port is blocked for some reason and the exhaust is insufficient, the CO concentration becomes high, so that it may be determined that the combustion fan has a failure. is there.

Accordingly, an object of the present invention is to provide a combustion apparatus and a combustion control method which realize optimum combustion control by monitoring both the air blowing capacity and the fuel supply amount by monitoring the CO concentration. And

[0009]

As shown in FIGS. 1 to 7, the combustion apparatus according to the present invention comprises a combustion means (burner 70) for burning fuel and a fan (combustion fan 70).
And supplies the rotated air required for combustion of the combustion unit fan motor (34), a fuel control valve for adjusting the supply of fuel to the combustion means and (proportional solenoid valve 32), the <br/> combustion unit CO be detected more CO concentration that occurs in the combustion
Detecting means (CO sensor 18) and the rotation of the fan motor
By controlling the opening of the fuel control valve
While maintaining an appropriate combustion state, the CO detection means
If a CO concentration exceeding the reference value is detected, the fan
Sustain combustion by increasing the rotation of the motor,
When the rotation of the fan motor reaches the upper limit rotation speed,
Controlling the fuel control valve so that the fuel
A fuel supply to the combustion means.
When the supply rate is set to the lower limit, an output indicating this is generated.
Control means (control unit 2) for generating
Receiving the force, the fuel supply amount is set to the lower limit
Notification means for notifying that the (display unit 52 or the audio output section 5
4).

Further, according to the combustion control method of the present invention, as shown in FIGS. 1 to 7, when the combustion means (burner 70) is performing the maximum combustion, the CO detection means (18) detects the CO.
When the combustion in which the concentration becomes equal to or more than the reference value continues for a certain number of times, the rotation speed of the fan motor (34) is increased at a fixed rate from the next combustion. To reduce the fuel supply from the combustion of the fuel.

In the combustion control method of the present invention, as shown in FIG. 5, when the combustion means is performing the maximum combustion, the time when the CO concentration is equal to or more than the reference value is equal to or more than the predetermined time. , The number of times of the fan motor is increased at a constant rate.

In addition, as shown in FIG. 5, the combustion control method according to the present invention is applied to a case where the combustion means is performing maximum combustion, the combustion is continued for a predetermined time, and the rotation of the fan motor is controlled. When the number reaches a certain number of revolutions, the amount of fuel to be supplied to the combustion means is reduced by the combustion.

Further, in the combustion control method of the present invention, a warning is issued when the reduced fuel supply amount is set to a lower limit value, as exemplified in FIG.

Further, as shown in FIG. 6, the combustion control method according to the present invention, when the reduced fuel supply amount is set to the lower limit value and the CO concentration exceeds the reference value,
Stop combustion with warning.

[0015]

According to the combustion apparatus and the combustion control method of the present invention, abnormal combustion is monitored by the CO concentration.
That is, when the amount of air with respect to the supply amount of fuel gas decreases,
An unstable combustion state occurs, and the CO concentration value increases. Such monitoring of the combustion state based on the CO concentration is useful for performing appropriate combustion control before shifting to incomplete combustion.

Therefore, in the combustion apparatus of the present invention, a CO detection means is provided in the exhaust system of the combustion means for detecting the CO concentration in the exhaust gas, and the CO concentration detected by the CO detection means is equal to a reference value. With the continued combustion exceeding, the opening of the fuel control valve is controlled together with the rotation of the fan motor. Further, when the control means sets the supply of the fuel to the combustion means to a lower limit, the setting is notified and the continuation of abnormal combustion is prevented.

In the combustion control method of the present invention, the case where the combustion means is performing maximum combustion is a precondition for control. The maximum combustion refers to combustion of a fuel amount for obtaining a heat amount necessary for heating a predetermined amount of water as a medium to be heated. The number of times of combustion in which the CO concentration is equal to or higher than the reference value is counted. The unit of counting is one combustion from the start of combustion to the end of combustion, and the combustion time is not considered. In short, 1
If the CO concentration becomes equal to or higher than the reference value during each combustion, it is regarded as one time. When the number of times continues for a predetermined number of times, for example, about 3 to 5 times, the number of revolutions of the fan motor is increased at a constant rate from the next combustion. That is, the amount of air required for combustion is increased. The reason why the number of times is continued is that even if the current time becomes abnormal, the next time may return to normal, and in such a case, there is no problem in safety. This is because, by setting the number of times of continuation as described above, there may be a case where the exhaust port becomes inadequate due to some kind of covering, or a case where the obstacle is removed to return to normal.

A limit value is set for the increase in the fan motor speed. This is also for safety. Therefore, when the rotation speed reaches a certain rotation speed or more, the fuel supply amount is reduced from the next combustion. As a result, the ratio between the fuel supply amount and the air amount changes, and abnormal combustion can be reliably avoided.

In short, according to the present invention, when the number of consecutive times that the CO concentration exceeds the reference value exceeds a predetermined number,
Increasing the fan motor speed to compensate for the decrease in the fan motor's air blowing capacity, and when the number of revolutions exceeds a certain speed, reduce the fuel supply to make effective use of the fan motor's current air blowing capacity. In addition, abnormal combustion is prevented.

Further, in the combustion control method of the present invention,
If the combustion time exceeds a certain time, that is, even if there is no problem in safety, there is a disadvantage that abnormal combustion is continued. Therefore, in the case of combustion exceeding a certain time, the number of revolutions of the fan motor is increased as an emergency measure to increase the amount of air and maintain the combustion.

In the combustion control method of the present invention,
When the combustion time exceeds a certain time, when the rotation speed of the fan motor reaches a certain rotation speed, the fuel supply amount to be supplied to the combustion means is reduced by the combustion. The air volume can be increased.

In the combustion control method of the present invention,
A warning is issued when the reduced fuel supply is set to the lower limit. That is, it prompts the user to clean the combustion fan.

In the combustion control method of the present invention,
When the reduced fuel supply amount is set to the lower limit and the CO concentration exceeds the reference value, the combustion is stopped with a warning to prevent the abnormal combustion from continuing, thereby ensuring higher safety. Is done.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments shown in the drawings.

FIG. 1 shows a general control system of a hot water supply apparatus which is an embodiment of a combustion apparatus and a combustion control method according to the present invention.

The hot water supply apparatus is provided with a control section 2 as control means for supplying fuel gas to the combustion means and controlling hot water supply. The control unit 2 is constituted by a microcomputer, and a central processing unit (CPU) 4 is installed as a processing means. The CPU 4 controls the number of combustions when the CO concentration reaches the reference value, together with the combustion control.
That is, it has a function as an error counter for counting the number of errors. This CPU 4 has R as a storage means.
The OM 8, the RAM 10, and the EEPROM 12 are linked. The ROM 8 is a read-only storage unit that stores various control programs such as a combustion control program and fixed data. The RAM 10 is a readable and writable storage unit that temporarily stores various data during control and calculation, and temporarily stores the number of combustions when the CO concentration reaches the reference value as a count value. Also, the EEPROM 12
A readable and writable storage means for storing data which needs to be updated and which is to be handled as a reference value for control.
Unlike M10, even after the power supply is stopped, the stored data can be held for the next control. In this embodiment, ROM8, RAM10 and EEPROM are used as storage means.
Although the OM 12 is listed, the storage unit of the control unit 2 may be a storage unit of another control device or a floppy disk as an external storage unit.

The CPU 4 has a multiplexer (MP)
X) 14 and analog / digital (A / D) converter 1
6 are linked. The MPX 14 is a means for taking in a plurality of inputs to the A / D conversion unit 16 in a time-sharing manner. In this embodiment, the MPX 14 detects the outputs from the CO sensor 18 and the first and second temperature sensors 20 and 22. Has been added. That is, each detection output captured in a time-sharing manner is A / D
It is added to the converter 16. Also, the A / D conversion unit 16
Convert analog input from outside to digital
4. In the case of the present embodiment, the
4 is configured as an external circuit, but may be incorporated in the CPU 4 and may take any form.

The CO sensor 18 is a CO concentration detecting means for electrically detecting the CO concentration in the exhaust gas. The detection output Eco is converted to a digital value by the A / D converter 16 and then sent to the CPU 4. Is entered. The CPU 4 takes in the detection output Eco at a fixed time from the start of combustion. The temperature sensor 20 is means for detecting the temperature of the supply water to be heated, and the temperature sensor 22 is means for detecting the tap water temperature. For example, the temperature of a thermistor or the like is converted into an electric signal and extracted.

The CPU 4 has an input / output unit (I / I / O) as a means for taking out data input and control output.
O) 24 are provided. Various detection means such as a flame detection circuit 26 and a drive circuit are connected to the I / O 24. The flame detection circuit 26 is a means for electrically detecting the presence or absence of flame on the combustion means side, and when detecting a flame, generates a voltage of a specific level representing the flame.

The flow rate sensor 28 is a means for detecting the flow rate of water flowing from the water supply system to the hot water supply system, and generates an electric signal indicating the flow rate. The controller 2 receives this flow rate and performs fuel control and the like.

The proportional solenoid valve drive circuit 30 is means for controlling the drive current of the electromagnetic solenoid of the proportional solenoid valve 32 installed in the fuel system. In the hot water supply device, it is necessary to obtain an opening corresponding to the flow rate of hot water. Output a large current value. Proportional solenoid valve 3
Numeral 2 is a means for controlling the supply of the fuel gas amount necessary for the burner as a combustion means. In the present invention, the control of the rotation speed of the fan motor 34 is combined with the change of the maximum fuel supply amount,
That is, the combustion number is also changed.

The igniter driving circuit 36 is a driving means of the igniter 38 for igniting the fuel injected from the ignition burner, and supplies a current for generating a spark required for ignition to the igniter 38.

The fan motor drive circuit 40 supplies a drive current required to rotate the fan motor 34. The rotation speed of the fan motor 34 is
Control is performed to increase the number of revolutions stepwise under certain conditions. The rotation speed of the fan motor 34 is
It is detected by the rotation detector 42 and applied to the I / O 24 with an electrical signal representative thereof.

A reset switch 44 is connected to the I / O 24 so that the I / O 24 can be newly installed or a combustion fan 72 can be used.
At the time of initialization after the cleaning shown in FIG. 2 is operated for initialization.

The control in the control section 2 is performed by operating a remote controller 46 which is a remote controller. Usually, since the combustion system is installed outdoors, a remote control device 46 is installed to remotely control the outdoor device. The remote controller 46 is provided with a remote controller 48 as control means for controlling remote control. This remote control unit 48 is configured by a microcomputer, similarly to the control unit 2. The remote controller 48 exchanges control signals with the controller 2 through the remote controller transceiver 50. Control input is applied to the CPU 4 and display output from the controller 2 is output from the I / O 24. A display unit 52 and an audio output unit 54 are connected to the remote control unit 48. The display unit 52 performs a warning display such as abnormal combustion, and the display unit 52 performs various displays such as a visual display and an acoustic display. The display means can be composed of various display devices such as a light emitting diode and a liquid crystal display for visual display, and various sounding devices such as buzzer and voice for acoustic display. In short, the display unit 52 includes various notification means for the user to perform necessary operations and avoid danger. The sound output unit 54 outputs the warning by voice. The input unit 56 is a unit for inputting set values from various input switches, and the operation switch 58 is a unit for instructing start of operation.

Next, FIG. 2 shows the configuration of the main body of the water heater. In the main body frame 60 formed in a rectangular shape,
A combustion system and a hot water supply system are built in. Fuel gas G
Is supplied to the gas supply port 62 and is guided to the proportional solenoid valve 32 via the supply pipe 64. The fuel gas G that has passed through the proportional solenoid valve 32 is supplied to a burner 70 that is a combustion unit of a combustion chamber 68 through a pipe 66. The combustion chamber 68 is provided at the center of the main body frame 60, and a combustion fan 72 is attached to the lower surface thereof.
2 is rotated by a fan motor 34.

Above the combustion chamber 68, a heat exchanger 74 is provided as a heating means for heating the feed water. A pipe 76 is spirally wound around the body of the heat exchanger 74, and a water supply pipe 78 is connected to one end of the heat pipe 74 so as to be guided to a lower side of the main body frame 60. The water supply port 80 is provided adjacent to the water supply port 80, and receives the water supply W from the water supply system. This supply water temperature is detected by the temperature sensor 20 installed in the pipeline 76. Also,
Hot water HW obtained by heating the heat exchanger 74 is guided to the outside such as a bath from a hot water supply port 84 through a thermo mixing valve 82 which is a mixing valve for mixing the hot water W from a water supply pipe 78.

An exhaust port 86 for discharging the exhaust gas passing through the heat exchanger 74 to the outside is provided on the upper side of the main body frame 60, and a cover 88 having a slit is attached to the outside thereof. Have been. Note that FIG.
Shows a state in which the front cover is removed, and in an actual apparatus, the front portion of the main body frame 60 is hidden by the front cover.

Next, FIG. 3 shows the configuration of the combustion means and the hot water supply mechanism in the main body. The same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. The combustion means is provided with a single burner 70, and the burner 70 is provided with a flame rod 92 and a spark plug 94 as ignition means, and the igniter 38 is connected to the ignition plug 94. . At the bottom of the burner 70,
A combustion fan 72 is mounted, and a fan motor 34 has a rotation detector 4 for electrically detecting the rotation.
2 are installed.

An exhaust part 100 is formed in an upper part of the combustion chamber 68 to constitute an exhaust system for discharging the combustion gas to the outside.
A CO sensor 18 for detecting the concentration is provided.

A heat exchanger 74 is installed above the burner 70, and a water governor 96 as a pressure adjusting means, a boiling prevention device 98, a temperature sensor 22
Etc. are attached.

The combustion control method of the present invention will be described by taking the above-described hot water supply device as an example.

FIG. 4 shows an initialization program in the combustion program. This initialization program is used at the time of new installation or when the cleaning of the combustion fan is completed. In step S1, it is determined whether or not the operation switch 58 is ON. If the operation switch 58 is not ON,
Move to step S3 . When the operation switch 58 is turned on
If the hot water tap is open, the process proceeds to step S2 to determine whether the hot water tap is open. If the hot water tap is open, the process returns to step S1. If the hot water tap is closed, step S2 is performed. Move to S3. In other words, this initialization program proceeds under the condition that the hot water tap is closed.

In step S3, it is determined whether or not the reset switch 44 is ON. Reset switch 4
If 4 is not ON, the process returns to step S1,
After step S1, the process proceeds to step S2. If the reset switch 44 is ON, the process proceeds to step S4 to clear the error count value stored in the RAM 10. That is, since this is an initial setting, the number of integrations in the RAM 10 is deleted to set the initial value to 0, and the process proceeds to step S5. In step S5,
The rotation speed of the fan motor is initialized, and the rate of increase n is set to 0%. The rate of rotation increase n% is stored in the EEPROM 12, and the stored contents are erased by this operation. Then, in step S6, the optimum maximum combustion number of the burner 70 is set, and in this embodiment, it is set to 16th. This number is an example and is not limited to this number. After such initialization, the initialization program is completed.

Here, the number of combustions represents the amount of heat generated by raising the temperature by 25 ° C. per minute in terms of the amount of water. The number 1 represents the temperature of 1 liter of water raised by 25 ° C. per minute. Says the ability, so the number 16 is 16 liters,
Number 10 indicates the ability to raise the temperature of 10 liters of water by 25 ° C. per minute.

Next, FIGS. 5, 6 and 7 show a combustion control program, in which a, b, c and d represent connectors between successive programs.

This combustion control program is executed by the CO sensor 1
When the detection output Eco of No. 8 reaches the reference level E1 (V) is regarded as an error, the number of times of occurrence of the error is integrated in units of the end from the start of combustion, and when the occurrence of the error is not continuous, The integrated value is deleted. Then, while repeating the accumulation and erasure of the number of occurrences of the error, when the accumulated number reaches the predetermined number k, the rotation speed N of the fan motor (FM) is increased stepwise by n%, and the rotation speed N Is the rotation speed N1 (rp
When m) is reached, the fuel supply amount, that is, the number of combustions is reduced to control the combustion state to an optimum state.

The combustion control program gives a warning when the maximum number of combustion reaches the lower limit, and the detection output Eco of the CO sensor 18 at the second number of reference levels E2 at the number of combustion. When (V) is reached, combustion is stopped together with an error display.

To explain the combustion control program, when the operation switch 58 is ON in step S11, the process proceeds to step S12, and it is determined whether or not the hot water tap is open.

If the hot water tap is opened in step S12, the process proceeds to step S13, where a combustion start operation for hot water supply is performed. In this combustion operation, the start of rotation of the fan motor 34, the supply of fuel gas, the ignition, and the main combustion are performed.

In step S14, it is determined whether the current combustion is the maximum combustion. In this embodiment, it is determined whether or not the current set combustion number is 10, and if it is not combustion, the process proceeds to step S15 to determine whether or not abnormal combustion is performed. That is, in step S15, it is determined whether or not the CO concentration exceeds the reference value, that is, whether or not the combustion is abnormal. Specifically, the detection output Eco of the CO sensor 18 is set to the first reference level. It is determined whether or not E1 (V) has been reached. The first reference level E1 is a value at which the CO concentration exceeds the reference value, that is, a value indicating that abnormal combustion occurs.

If the detection output Eco is less than E1 (V) in step S15, the flow shifts to step S16 to clear the number of times of accumulation in the RAM 10, and then to step S15.
Return to That is, in step S16, the number of previous integrations,
That is, by clearing the error count value to 0, if the combustion is normal in units of the start of combustion, the number of past abnormal combustions is deleted to 0, and only the continuous number of abnormal combustions is integrated. It was.

In step S17, the content of the data of the detection output Eco of the CO sensor 18 is continually taken for a certain period of time. In this embodiment, three minutes are set. When three minutes have elapsed, the process proceeds to step S18, where "1" is added to the error count value stored in the RAM 10, and the added value is updated and stored. That is,
Since an abnormality occurred at the start of the current combustion, it is counted as one time. After the end of combustion, the number of times
2 and the operation switch 58 is turned on to enable the EEPR
The OM 12 initializes the RAM 10.

In the step S19, it is determined whether or not the error count value temporarily stored in the RAM 10 is k times or more. That is, it is determined whether or not the count value of continuous combustion abnormalities has reached k times in units of the start of combustion. This k is, for example, about 3 to 5.

If the number of combustion abnormalities reaches k in step S19, the process proceeds to step S20 (FIG. 6), and the fan motor speed N is increased by n% from the next combustion. Here, assuming that the rotation speed after n% increase is N1 (> N), N1
1 = Ni (1 + n / 100) (rpm). Here, Ni represents the current fan motor rotation speed. This increase in the rotation speed changes the drive current value flowing from the fan motor drive circuit 40 to the fan motor 34 under the control of the CPU 4 so as to become the rotation speed N1.

Then, in step S21, the RAM 10
The error count value as the integrated value stored in is cleared to zero. That is, the initial state is established by increasing the rotation speed N of the fan motor 34 to N1.

In step S22, it is determined whether or not the next fan motor rotation speed N is equal to or higher than a predetermined rotation speed, that is, a reference upper limit rotation speed Nm. The reference upper limit rotation speed Nm is set with the fan motor rotation speed as an increase limit, and this value is set based on the safety of the fan motor 34 and the relative relationship with the number of combustions.

When the fan motor speed reaches the reference upper limit speed Nm in step S22, the maximum combustion number is set to 10 in the next combustion in step S23, and the process proceeds to step S24.

Then, in step S24, it is determined whether or not the current combustion has elapsed for a predetermined time, for example, for 30 consecutive minutes. Even if the number of combustions is reduced from the next time, abnormal combustion in the current situation cannot be ignored, so if the combustion time is long, increase the fan motor speed as a first aid measure to avoid abnormal combustion. It was done. Also, in step S19, if the number of accumulations in the RAM 10 is equal to or less than k, the process shifts to step S24 to determine whether or not combustion is continuous.

If the combustion has continued for 30 minutes, the process proceeds to step S25, and the fan motor speed is increased by m% only this time. Assuming that the fan motor rotation speed after the rise is N2, N2 = Ni (1 + m / 100) (r
pm). The safe combustion is sustained by the increase in the rotation speed.

In step S26, it is determined whether the fan motor speed is equal to or higher than the reference upper limit speed Nm. If the fan motor speed is not higher than the reference upper limit speed Nm,
The process proceeds to step S27 to determine whether or not the level of the detection output Eco of the CO sensor 18 is equal to or higher than the first reference level E1 (V) as a determination as to whether or not the combustion is abnormal. If the level of the detection output Eco is equal to or higher than the first reference level E1 (V), the process proceeds to step S28, and it is determined whether a predetermined time, for example, 10 minutes, has elapsed since the increase in the fan motor speed. Step S2 until a predetermined time has elapsed.
7. Repeat S28, if 10 minutes have passed,
The process shifts to step S25 to perform the processing from step S25. By repeating this, the combustion state can be monitored as long as the combustion continues.

If the fan motor speed N has risen to the reference upper limit speed Nm or more in step S26, the process proceeds to step S29, in which the maximum combustion number is reduced to 10 for the current combustion only, and a safe combustion state is established. Force a transition.

Then, steps S14 and S29
In step S30, the maximum combustion number is set to 10
Then, the process proceeds to step S31 and the display unit 52
And a warning is given by voice from the voice output unit 54. That is, the user is notified that the combustion fan 72 is cleaned or the exhaust port 86 is closed.

In step S32, it is determined whether or not the maximum combustion is No. 10 combustion. In the case of the maximum No. 10 combustion, the process proceeds to step S33, and it is determined whether or not the level of the detection output Eco of the CO sensor 18 is equal to or higher than a second reference level E2 (> E1). If the level of the detection output Eco is equal to or higher than the reference level E2 (V), an error is displayed in step S34, and a warning that an error has occurred is issued from the audio output unit 54 by audio. Then, step S3
In step 5, the proportional solenoid valve 32 is forcibly closed to stop combustion. The reason why such combustion is stopped is to ensure safety when the exhaust port 86 is closed due to, for example, snowfall or some other reason.

As described above, the main points of each processing in the combustion control program are as follows. a. The number of times the flame temperature exceeds the reference value during a certain period of time at the start of combustion, that is, the number of continuous abnormal combustions is counted, and the counted value is stored. Uncertain factors can be avoided, and maintenance of the fan motor can be easily managed. b. The RAM 10 as storage means is cleared by the operation of the reset switch 44, and after the abnormal combustion, the accumulated number is also deleted when the next combustion is normal. Even when the fan motor speed is increased, the error count value is returned to the initial value 0. c. The maximum combustion number is set by initializing the fan motor speed. In this embodiment, the combustion is No. 16. d. The fan motor rotation speed is increased stepwise as the cumulative number of abnormal combustion reaches a predetermined number. If the rotation speed exceeds the reference upper limit rotation speed, the number of combustions is reduced from the next time. e. Even if the fan motor rotation speed does not exceed the reference upper limit rotation speed, the fan motor rotation speed is increased only this time if the combustion time exceeds a certain time thereafter. In this case, if the fan motor speed exceeds the reference upper limit speed, the maximum combustion number is reduced. f. When the maximum combustion number is reduced, that is, when the number is shifted to the lowest value, a warning is issued, and after confirming the combustion number, the value of the detection output of the CO sensor 18 is determined, and an error is displayed. At the same time, the combustion is stopped. It is possible to know that the combustion is abnormal, and to avoid the danger of maintaining the abnormal combustion.

In the embodiment, the number of combustions is set in two stages. However, the number of combustions may be three or more, and the number of combustions may be other than 10 and 16.

Further, in the embodiment, a hot water supply device using a single burner has been described as an example of the combustion means. However, the combustion control method of the present invention can be applied to a combustion device using two or more burners. Needless to say, in such a case, control for switching the number of burner drives is required.

[0068]

As described above, according to the present invention,
The following effects are obtained. a. Increases the number of revolutions of the fan motor in accordance with the number of combustions when the CO concentration exceeds the reference value, which can compensate for the reduced performance of the combustion fan, avoid abnormal combustion, and extend the life of the combustion fan. And the number of maintenance and management can be reduced. b. If the burning time becomes longer,
Since the number of revolutions of the fan motor can be increased as an emergency measure, abnormal combustion can be avoided and safety can be improved. c. If the burning time becomes longer,
As an emergency measure, the number of revolutions of the fan motor is increased, and when the number of revolutions becomes equal to or higher than a certain number of revolutions, the fuel supply amount is suppressed, so that abnormal combustion can be avoided and safety can be improved. d. When the reduced fuel supply amount is set to the lower limit, a warning is issued, so that it is possible to know that the cleaning time of the combustion fan has come. e. When the reduced fuel supply amount is set to the lower limit and the CO concentration exceeds the reference value, the combustion is stopped together with a warning, so that the continuation of abnormal combustion can be avoided, and higher safety can be secured. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a combustion apparatus and a combustion control method of the present invention.

FIG. 2 is a front view showing a main body of the hot water supply apparatus which is one embodiment of the combustion apparatus of the present invention.

FIG. 3 is a system diagram showing a combustion mechanism of the combustion device shown in FIG. 2;

FIG. 4 is a flowchart showing an initialization program in a combustion control program as one embodiment of the combustion control method of the present invention.

FIG. 5 is a flowchart showing a combustion control program which is an embodiment of the combustion control method of the present invention.

FIG. 6 is a flowchart showing a combustion control program following the combustion control program shown in FIG.

FIG. 7 is a flowchart showing a combustion control program following the combustion control program shown in FIGS. 5 and 6.

[Explanation of symbols]

 2 Control unit 18 CO sensor (CO detection means) 32 Proportional solenoid valve (fuel control valve) 34 Fan motor 52 Display unit (notification unit) 54 Audio output unit (notification unit) 70 Burner (combustion unit) 100 Exhaust unit (exhaust system) )

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshiya Tatsumi 201 Nishi-Kashiwara Nitta, Fuji City, Shizuoka Prefecture Inside Takagi Sangyo Co., Ltd. (56) References JP-A-63-294420 (JP, A) JP-A-63- 108114 (JP, A) JP-A-3-199815 (JP, A) JP-A-1-239316 (JP, A)

Claims (6)

(57) [Claims] A combustion unit 1. A burning fuel, air and a fan for supplying the motor required for combustion of the combustion unit by rotating the fan, and a fuel control valve for adjusting the supply of fuel to the combustion unit, wherein and CO detection means for detecting the CO concentration more generated in the combustion of the combustion unit, the opening degree of the fuel control valve with rotation of the fan motor
Control to maintain an appropriate combustion state
In addition, the CO detection means detects a CO concentration exceeding a reference value.
In this case, the rotation of the fan motor is increased.
More combustion is sustained, and the rotation of the fan motor reaches the upper limit
When the number of turns is reached, the fuel control valve is controlled to
Limiting the fuel supply to the baking means,
The supply of fuel to the stage is set to the lower limit
Control means for generating an output representing the output, and receiving the output of the control means, the fuel supply amount decreases.
And a notifying means for notifying that the limit value is set . 2. When the combustion means is performing maximum combustion, when the combustion in which the CO concentration in the exhaust gas exceeds the reference value continues for a predetermined number of times, the rotation speed of the fan motor is increased at a constant rate from the next combustion. A combustion control method characterized by reducing the fuel supply amount from the next combustion when the rotation speed reaches a certain rotation speed or more. 3. When the combustion means is performing maximum combustion, and when the time when the CO concentration is equal to or higher than a reference value has exceeded a predetermined time, the number of times of the fan motor is increased by a predetermined ratio only for the combustion. 3. The method according to claim 2, wherein:
The combustion control method as described. 4. When the combustion means is performing maximum combustion, and when the combustion continues for a certain period of time and the number of revolutions of the fan motor reaches a certain number of revolutions, only the combustion means the combustion means. 3. The combustion control method according to claim 2, wherein the amount of fuel to be supplied to the fuel cell is reduced. 5. The combustion control method according to claim 2, wherein a warning is issued when the reduced fuel supply amount is set to a lower limit value. 6. The method according to claim 2, wherein when the reduced fuel supply amount is set to a lower limit value, when the CO concentration in the exhaust exceeds a reference value, combustion is stopped together with a warning. The combustion control method as described.