JP2988834B2 - Hot water supply apparatus and hot water supply 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 hot water supply apparatus and a hot water supply control method for monitoring a combustion state and performing hot water supply control in conjunction with the combustion control.

[0002]

2. Description of the Related Art A hot water supply device includes a burner for burning fuel, and a combustion fan for feeding air required for combustion or exhausting air to a combustion chamber in which the burner is installed. 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]

By the way, in such a water heater, the capacity of the combustion fan directly affects the combustion of the fuel, and incompletely induces incomplete combustion. is there. 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 request the user for such work.

Therefore, CO (carbon monoxide gas) is supplied to the combustion chamber.
A method has been adopted in which a sensor is installed to monitor the CO concentration in the exhaust gas, and the rotation speed of the combustion fan is increased in accordance with the detected output to prevent a decrease in the amount of supplied air. JP
An example thereof is "combustion device" of 1988-294420 . 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 must be considered whether the blowing capacity of the combustion fan is appropriate in relation to the amount of fuel supplied, and the CO concentration value varies with the amount of fuel supplied. Are known. Since the CO concentration is directly related to the combustion state, it is possible to know the CO concentration from the combustion state such as the flame temperature. However, compared to such an indirect method, the CO sensor directly detects the CO concentration. However, it is advantageous in that the combustion state is monitored based on the concentration output.

[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. possible.

Accordingly, the present invention provides a hot water supply apparatus and a hot water supply apparatus which monitors a CO concentration and controls both a blowing capacity and a fuel supply amount to perform hot water supply control in conjunction with optimal combustion control. It is an object to provide a control method.

[0009]

As shown in FIGS. 1 to 15, a hot water supply apparatus according to the present invention supplies combustion means (burner 80) for burning fuel and air required for combustion of the combustion means. A fan motor (32) and a fuel control valve (proportional solenoid valve 3) for regulating the supply of fuel to the combustion means.
0), CO detection means (CO sensor 16) for detecting the CO concentration generated by combustion of the combustion means, a heat exchanger (82) heated by the combustion means, and an amount of water supplied to the heat exchanger. A water amount control valve (44) for controlling
When the CO concentration the CO detection means detects combustion exceeding the reference value continues, on the rotation of the fan motor
The fan motor's speed reaches a certain speed.
The opening degree of the fuel control valve and the water amount control valve
Controlling the fuel supplied to the combustion means
Together, characterized by the Bei Etako a controller for avoiding water supply amount (the control unit 22) to said heat exchanger.

As the CO detecting means, a means for directly or indirectly detecting the CO concentration can be used. For example, a CO sensor for directly detecting the CO concentration from the exhaust gas, a flame temperature in the combustion means, Temperature sensor (thermocouple 16A, platinum resistance wire 16
B) or from the emission color of the flame in the combustion means
Temperature sensor (CdS cell 16
C).

Further, according to the hot water supply control method of the present invention, as shown in FIG. 4 to FIG. Then, the rotation speed of the fan motor is increased at a fixed rate from the next combustion, and when the rotation speed reaches a certain rotation speed or more, the fuel supply amount is reduced from the next combustion and the combustion means The amount of water supplied to the heat exchanger (82) being heated is suppressed.

In the hot water supply control method of the present invention,
The case where the combustion means is performing maximum combustion, and the C
When the time during which the O concentration is equal to or more than the reference value becomes equal to or more than a certain time, the number of times of the fan motor is increased at a certain rate by the combustion.

Further, in the hot water supply control method of the present invention,
When the combustion means is performing maximum combustion, and the combustion continues for a certain period of time, and when the number of revolutions of the fan motor reaches a certain number of revolutions, the fuel to be supplied to the combustion means only for the combustion. The supply amount is reduced, and the amount of water supplied to the heat exchanger is suppressed.

In the hot water supply control method of the present invention,
When the reduced fuel supply amount is set to the lower limit, a warning is issued.

In the hot water supply control method according to the present invention, when the reduced fuel supply amount is set to the lower limit, and when the CO concentration in the exhaust exceeds the reference value, a warning and a combustion stop are issued. The water supply to the heat exchanger is stopped.

[0016]

According to the hot water supply apparatus and the hot water supply control method of the present invention, abnormal combustion is monitored based on the CO concentration in the exhaust gas. That is, when the amount of air with respect to the supply amount of the 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 in realizing appropriate combustion before shifting to incomplete combustion and performing hot water supply control with high safety.

Therefore, in the hot water supply apparatus of the present invention, a CO detection means for detecting the CO concentration in the exhaust gas is provided in the exhaust system of the combustion means, and combustion in which the CO concentration detected by the CO detection means exceeds a reference value is performed. When continued, the fan motor
Increase the number of rotations and the number of rotations reaches a certain number of rotations
Control the opening of the fuel control valve and
The opening is controlled to reduce the amount of fuel and water supply . That is, while supplying the predetermined air while maintaining the rotation of the fan motor,
If the fuel supply is reduced by controlling the fuel control valve, proper combustion can be obtained, but in addition, control of the opening of the water amount control valve,
That is, by suppressing the maximum water amount, the combustion state can be maintained and the generation of CO can be suppressed.

In the hot water supply device of the present invention,
The detection means only needs to be able to detect the CO concentration, and may be either direct or indirect. Therefore, in the present invention,
A CO sensor for directly detecting the CO concentration from the exhaust gas, a temperature sensor for indirectly detecting the CO concentration from the flame temperature in the combustion means, or a CO sensor from the emission color of the flame in the combustion means.
It has been clarified that it can be configured with a temperature sensor that detects the concentration indirectly. These sensors can electrically obtain an output corresponding to the CO concentration, and can know the CO concentration from the output level. When the level is different for each sensor, it is sufficient to deal with it by an amplifying unit or a level converting unit, and the difference in the level is not an essential problem.

In the hot water supply 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 continuations as described above, when the exhaust port is covered with some kind of gas and the exhaust becomes insufficient, if the obstacle is removed, the exhaust port may return to the normal state.

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 to preventing abnormal combustion, the amount of water supplied to the heat exchanger is reduced. That is, the optimum hot water supply is realized by setting the water supply corresponding to the decrease in the combustion capacity.

In the hot water supply 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 combustion exceeding a certain period of time, as an emergency measure, the number of rotations of the fan motor is increased to increase the amount of air, so that the combustion is continued and the amount of hot water supplied is suppressed.

Also, in the hot water supply control method of the present invention,
If the combustion time exceeds a certain time and the rotation speed of the fan motor reaches a certain rotation speed, the amount of fuel supply to be supplied to the combustion means is reduced by the amount of the combustion. The amount is increased. At the same time, the opening of the water flow control valve is narrowed to suppress the water supply.

In the hot water supply 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 and informs the user that the hot water supply has been restricted for safety.

In the hot water supply control method of the present invention,
When the reduced fuel supply amount is set to the lower limit value, when the CO concentration exceeds the reference value, a warning, a combustion stop, and a water supply stop are performed, so that abnormal combustion can be prevented from continuing, and higher safety can be achieved. Nature is secured.

[0026]

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 an embodiment of a hot water supply apparatus and a hot water supply control method according to the present invention.

The hot water supply apparatus includes a control unit 2 as control means for supplying fuel gas to the combustion means and performing hot water supply operation.
Is provided. 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 has a function as an error counter for counting the number of combustions in which the CO concentration has reached the reference value, that is, the number of errors, in addition to the combustion control. The ROM 4, the RAM 8, and the EEPROM 10 are linked to the CPU 4 as storage means. The ROM 6 is a read-only storage unit that stores various control programs such as a combustion control program and fixed data. The RAM 8 is a readable and writable storage unit for temporarily storing various data during control and calculation, and temporarily stores the number of combustions at which the CO concentration reaches the reference value as a count value. The EEPROM 10 is readable and writable storage means for storing data which needs to be updated and which is handled as a control reference value.
Unlike FIG. 8, even after the power supply is stopped, the stored data can be held for the next control. In this example,
ROM6, RAM8 and EEPROM1 as storage means
Although 0 is listed, as the storage means of the control unit 2, a storage means of another control device, a floppy disk, or the like can be used as an external storage means.

The CPU 4 has a multiplexer (MP)
X) 12 and analog / digital (A / D) converter 1
4 are linked. The MPX 12 is a means for taking in a plurality of inputs to the A / D converter 14 in a time-division manner. In this embodiment, the MPX 12 detects detection outputs from the CO sensor 16, the first and second temperature sensors 18 and 20. Has been added. That is, each detection output captured in a time-sharing manner is A / D
It is added to the converter 14. Also, the A / D conversion unit 14
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 16 is a CO detecting means for electrically detecting the concentration of CO in the exhaust gas, and has a detection output E.
co is converted into a digital value by the A / D converter 14 and then input to the CPU 4. The CPU 4 takes in the detection output Eco at a fixed time from the start of combustion. The temperature sensor 18 is means for detecting the temperature of the supply water to be heated, and the temperature sensor 20 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 / O) as a means for inputting data and taking out control output.
O) 22 are provided. Various detection means such as a flame detection circuit 24 and a drive circuit are connected to the I / O 22. The flame detection circuit 24 is a means for electrically detecting the presence or absence of a 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 26 is 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 control unit 2 performs hot water supply control and the like in response to the flow rate.

The proportional solenoid valve drive circuit 28 is a means for controlling the drive current of the electromagnetic solenoid of the proportional solenoid valve 30 installed in the fuel system, and is necessary for the hot water supply device to heat the hot water to the flow rate and the set temperature. It outputs a current value for obtaining an opening corresponding to a large amount of heat. The proportional solenoid valve 30 is a means for controlling the supply of the fuel gas amount necessary for the burner as the combustion means. In the present invention, the control of the rotation speed of the fan motor 32 and the change of the maximum fuel supply amount are performed. That is, the number of combustions is also changed.

The igniter drive circuit 34 is a drive means of the igniter 36 for igniting the fuel injected from the ignition burner, and supplies a current for generating a spark required for ignition to the igniter 36.

The fan motor drive circuit 38 supplies a drive current required to rotate the fan motor 32. The rotation speed of the fan motor 32 is
Control is performed to increase the number of revolutions stepwise under certain conditions. The rotation speed of the fan motor 32 is
It is detected by the rotation detector 40 and applied to the I / O 22 with an electrical signal representative thereof.

The water amount control valve drive circuit 42 generates a drive current necessary for controlling the water supply amount, that is, the opening of the water amount control valve 44 for controlling the hot water supply amount. The water amount control valve 44 is controlled in conjunction with the combustion control by the control unit 2.

Further, a reset switch 46 is connected to the I / O 22 so that the I / O 22 can be newly installed or a combustion fan 48 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 control device 50 which is a remote control means. Usually, since the combustion system is installed outdoors, a remote control device 50 is installed to remotely control the outdoor device. This remote control device 50 is provided with a remote control control unit 52 as control means for controlling remote control. The remote controller control unit 52 is configured by a microcomputer similarly to the control unit 2. The remote control unit 52 transmits and receives control signals to and from the control unit 2 through the remote control transmission / reception unit 54. The control input is applied to the CPU 4, and the display output from the control unit 2 is output from the I / O 22. The display unit 56 and the audio output unit 58 are connected to the remote control unit 52, and the display unit 56 displays a warning such as abnormal combustion. Various display means such as a visual display and an acoustic display are used for the display unit 56. In the visual display, various displays such as a light emitting diode and a liquid crystal display,
The acoustic display can be composed of various sounding devices such as a buzzer and voice. In short, the display unit 56 includes various notification means for the user to perform necessary operations and avoid danger. The sound output unit 58 outputs the warning by voice. The input unit 60 is a means for inputting set values from various input switches, and the operation switch 62 is a means for instructing start of operation. Also,
The temperature control volume 64 is a means for adjusting the tap water temperature, and is used for manually setting the ratio of unheated water in the hot water supply amount.

Next, FIG. 2 shows the configuration of the hot water supply apparatus main body. A combustion system and a hot water supply system are built in the main body frame 70 formed in a rectangular shape. The fuel gas G is supplied to the gas supply port 72, and is guided to the proportional solenoid valve 30 via the supply pipe 74. The fuel gas G that has passed through the proportional solenoid valve 30 is supplied through a pipe 76 to a burner 80 that is a combustion unit of a combustion chamber 78. The combustion chamber 78 is provided at the center of the main body frame 70, and a combustion fan 48 is attached to a lower surface thereof, and the combustion fan 48 is rotated by the fan motor 32.

Above the combustion chamber 78, a heat exchanger 82 is provided as a heating means for heating the feed water. A pipe 84 is spirally wound around the body of the heat exchanger 82, and a water supply pipe 86 is connected to one end of the pipe 84 so as to be guided to a lower side of the main body frame 70. A water supply port 88 is disposed adjacent to the water supply port, and receives the water supply W from the water supply system. The amount of supplied water is detected by the flow rate sensor 26, and the temperature of the supplied water is detected by the temperature sensor 18 (FIG. 3) installed in the water supply pipe 86. The hot water HW obtained by heating the heat exchanger 82 is mixed with the feed water W from the feed pipe 86,
The water is supplied from the hot water supply port 89 to the outside such as a bath via the water amount control valve 44. The opening of the water amount control valve 44 is adjusted by a motor 45. The motor 45 has a drive control output from the water amount control valve drive circuit 42 in order to set an opening required for the water amount control valve 44. Is supplied.

An exhaust port 90 for discharging exhaust gas having passed through the heat exchanger 82 to the outside is provided on the upper side of the main body frame 70, and a cover 92 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 70 is hidden by the front cover.

Next, FIG. 3 shows a combustion and water supply system of the hot water supply device in the main body, and 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 80, and the burner 80 is provided with a flame rod 94 and a spark plug 96 as ignition means, and the igniter 36 is connected to the ignition plug 96. . At the bottom of burner 80,
A combustion fan 48 is mounted, and a fan motor 32 has a rotation detector 4 for electrically detecting the rotation.
0 is set.

An exhaust part 100 is formed in the upper part of the combustion chamber 78 as an exhaust system for discharging combustion gas to the outside.
A CO sensor 16 for detecting the concentration is provided.

A heat exchanger 82 is installed above the burner 80, and a water governor 102 or the like as a pressure adjusting means is attached to a pipe line 84 thereof.

Next, a method of controlling hot water supply in the hot water supply apparatus will be described.

FIG. 4 shows an outline of a hot water supply control program in the hot water supply apparatus. In step S1, the combustion operation program (FIGS. 6, 7, and 8) operates, and the hot water supply operation program (FIGS. 9, 10, and 11) in step S2 operates accordingly. The combustion operation program and the hot water supply operation program have an inseparable relationship, and both are processed in parallel.

FIG. 5 shows an initialization program in the combustion operation program. This initialization program is used at the time of new installation or when the cleaning of the combustion fan is completed. In step S11, it is determined whether the operation switch 62 is ON. If the operation switch 62 is ON, the process proceeds to step S12. Step S12
Then, it is determined whether or not the hot water tap is opened. If the hot water tap is open, the process returns to step S11. If the hot water tap is closed, the process proceeds to step S13. In other words, this initialization program proceeds under the condition that the hot water tap is closed.

In step S13, the reset switch 46
Is turned on. If the reset switch 46 has not been turned ON, the process returns to step S11, and proceeds to step S12 via step S11. If the reset switch 46 is ON, the process proceeds to step S14 to clear the error count value stored in the RAM 8. That is, since this is an initial setting, the number of integrations in the RAM 8 is deleted to set the initial value to 0, and the process proceeds to step S15. Step S1
In 5, the number of rotations of the fan motor 32 is initialized, and the rate of increase n is set to 0%. The rate of rotation increase n% is EEPROM
The stored contents are erased by this operation.
Then, in step S16, the optimum maximum combustion number of the burner 80 is set, and in this embodiment, it is set to 16.
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, and 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. 6, 7 and 8 show a combustion operation program, in which a, b, c and d represent connectors between successive programs.

This combustion operation program is executed by the CO sensor 1
When the detection output Eco of No. 6 reaches the reference level E1 (V) is regarded as an error, the number of occurrences 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.

This combustion operation program gives a warning when the maximum combustion number reaches the lower limit, and at the combustion number, the detection output Eco of the CO sensor 16 becomes the second reference level E2. When (V) is reached, combustion is stopped together with an error display.

The combustion operation program will be described. If the operation switch 62 is ON in step S21, the process proceeds to step S22, and it is determined whether the hot water tap is open.

If the hot-water tap is opened in step S22, the flow shifts to step S23 to perform a combustion start operation for hot-water supply. In this combustion operation, rotation of the fan motor 32 is started, fuel gas is supplied, ignition is performed, and main combustion is performed.

In step S24, it is determined whether the current combustion is the maximum combustion. In this embodiment, it is determined whether or not the current combustion setting number is 10, and if it is not combustion, the process proceeds to step S25 to determine whether or not abnormal combustion is performed. That is, in step S25, it is determined whether or not the CO concentration exceeds the reference value, that is, whether or not abnormal combustion is occurring. Specifically, the detection output Eco of the CO sensor 16 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 S25, the flow shifts to step S26 to clear the accumulated number of the RAM 8, and returns to step S25. That is, in step S26, by clearing the previous number of times of accumulation, that is, 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 cleared to 0. Therefore, only the number of continuous abnormal combustions is integrated.

In step S27, the data acquisition of the detection output Eco of the CO sensor 16 is performed continuously for a certain period of time. In this embodiment, three minutes are set. When three minutes have elapsed, the flow shifts to step S28 to set the error count value stored in the RAM 8 to "1".
Is added, and the added value is updated and stored. That is, since an abnormality has occurred at the start of the current combustion, it is counted as one time. This number of times is stored in the EEPROM 10 after the end of the combustion, and the operation of the operation switch 62 turns the EEPROM 1 on.
The value is initialized from 0 to the RAM 8.

In the step S29, it is determined whether or not the error count value temporarily stored in the RAM 8 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 S29, the process proceeds to step S30 (FIG. 7), 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 38 to the fan motor 32 under the control of the CPU 4 so as to become the rotation speed N1.

Then, in a step S31, the error count value as an integrated value stored in the RAM 8 is cleared to zero. That is, the initial state is established by increasing the rotation speed N of the fan motor 32 to N1.

In step S32, 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 32 and the relative relationship with the number of combustions.

If the fan motor rotation speed has reached the reference upper limit rotation speed Nm in step S32, the maximum combustion number is set to 10 in the next combustion in step S33, and the process proceeds to step S34.

Then, in step S34, it is determined whether or not the current combustion has elapsed for a predetermined time, for example, continuous 30 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 S29, if the number of accumulations in the RAM 8 is equal to or less than k, the process shifts to step S34 to determine whether or not combustion is continuous.

If the combustion has continued for 30 minutes, the process proceeds to step S35, 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 S36, 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 S37 to determine whether or not the level of the detection output Eco of the CO sensor 16 is equal to or higher than the first reference level E1 (V) as a determination as to whether or not abnormal combustion has occurred. 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 S38, and it is determined whether a predetermined time, for example, 10 minutes, has elapsed since the increase in the fan motor speed. Step S3 until a predetermined time elapses.
7. Repeat S38, if 10 minutes have passed,
The process shifts to step S35 to perform the processing from step S35. By repeating this, the combustion state can be monitored as long as the combustion continues.

If the fan motor rotation speed N has risen to the reference upper limit rotation speed Nm or more in step S36, the process proceeds to step S39, in which the maximum combustion number is reduced to 10 for the current combustion, and a safe combustion state is set. Force a transition.

Then, steps S24 and S39
In step S40, the maximum combustion number is set to 10
Then, the process proceeds to step S41, and the display unit 56
And a warning is given by voice from the voice output unit 58. That is, it prompts the user to clean the combustion fan and informs the user that the hot water supply has been restricted for safety.

In step S42, it is determined whether the maximum combustion is No. 10 combustion. In the case of the maximum No. 10 combustion, the process proceeds to step S43, and it is determined whether or not the level of the detection output Eco of the CO sensor 16 is equal to or higher than the second reference level E2 (> E1). When the level of the detection output Eco is equal to or higher than the reference level E2 (V), an error is displayed in step S44, and a warning that an error has occurred is issued from the audio output unit 58 by audio. Then, step S4
In step 5, the proportional solenoid valve 30 is forcibly closed to stop the combustion. The reason why such combustion is stopped is to ensure safety when the exhaust port 90 is closed due to, for example, snowfall or some other reason.

Next, FIGS. 9 and 10 show hot water supply operation programs in the hot water supply control method shown in FIG.
In step S51, the hot water supply temperature is set. The setting of the hot water supply temperature is a setting of the tap water temperature by the user. Then, in step S52, the flow sensor 26
To determine whether or not the hot water tap is open. This hot water tap is opened when the user needs it,
There is a case of automatic hot water supply to a bath or the like. In step S53, after the rotation of the fan motor 32 is started, the ignition operation is started.

In step S54, the igniter 36 is set to O
N, the process proceeds to step S55, and the proportional solenoid valve 30 is opened to a predetermined opening. In step S56, flame detection is performed by the flame detection circuit 24. When the flame is detected, in step S57, the igniter 36 is turned off to complete the ignition operation. Such an ignition operation is common to the combustion operation, and steps S53 to S57 show the position in the hot water supply operation program.

In step S 58, the amount of incoming water is fetched based on the output of the flow sensor 26, and the value is stored in the RAM 8. In step S59, the input water temperature is taken in based on the detection output of the temperature sensor 18, and this value is also stored in the RAM.
8 is stored.

In step S60, the opening of the proportional solenoid valve 30 is calculated based on the incoming water temperature, the incoming water amount, and the set temperature, and the opening operation of the proportional solenoid valve 30 is started. The opening of the proportional solenoid valve 30 is the amount of fuel gas supplied to the burner 80. As described above, the supply amount of the fuel gas is represented by the number. In step S61, the opening of the proportional solenoid valve 30 is controlled to a calculated value. This control is performed by the drive output of the proportional solenoid valve drive circuit 28 by the control output of the control unit 2.

In step S62, the temperature sensor 20 detects the temperature of the hot water, that is, the temperature of the mixed hot water obtained as a result of mixing the hot water with the hot water, and takes in the detected value.
This value is stored in the RAM 8.

In step S63, the opening degree of the proportional solenoid valve 30 is adjusted according to the difference between the mixed hot water temperature and the set temperature. In step S64, it is determined whether or not the temperature of the mixed hot water has shifted to the set temperature, and the control of the proportional solenoid valve 30 is performed until the temperature of the mixed hot water reaches the set temperature.

Then, in step S65, the flow rate sensor 2
It is determined whether or not 6 is OFF, and whether or not the hot water tap is closed is confirmed. If the flow rate sensor 26 is OFF, the process proceeds to step S66 to close the proportional solenoid valve 30, and then proceeds to step S67 to stop the fan motor 32 and end the hot water supply operation.

Next, FIG. 11 is a program showing the relationship between the hot water supply amount and the number setting in the hot water supply operation program.

In step S71, the maximum number of hot tap water is determined. Therefore, the set temperature T2 is taken in step S72, and the incoming water temperature T1 is taken in step S73. In step S74, the maximum hot water supply amount is calculated. This maximum tapping amount Q is calculated by the number of symbols × 25 (° C.) / (T2−T1). That is, the maximum amount of hot water is proportional to the number, with 25 being a proportionality constant, and inversely proportional to the difference in the set temperatures.

After the calculation of the maximum hot water supply amount, step S7
The process proceeds to step S5, where the water amount control valve 44 is driven, and step S76 is performed.
Then, it is determined whether or not the amount of hot water has reached the calculated amount of hot water. When the flow reaches the maximum hot water supply amount, the drive of the water amount control valve 44 is stopped, and the number setting is completed.

Next, FIGS. 12 and 13 show a second embodiment of the hot water supply apparatus and the hot water supply control method according to the present invention.

In the first embodiment, CO detection means
Although the CO concentration in the exhaust gas is directly detected using the sensor 16, the second embodiment uses a thermocouple 16A as a first temperature sensor for detecting a flame temperature in the burner 80 using a thermocouple. This thermocouple 16A is installed on the flame of the burner 80 as shown in FIG. 13 to detect the flame temperature. That is, the CO concentration is closely related to the flame temperature, and when the flame temperature increases, the flame turns red,
In that case, the CO concentration in the exhaust gas increases, and the CO concentration is proportional to the flame temperature. Therefore, by detecting the flame temperature with the thermocouple 16A, the CO concentration can be known, and by making the detection output of the thermocouple 16A correspond to the detection output of the CO sensor 16, the hot water supply shown in FIGS. Control can be realized. When the output level of the thermocouple 16A is low, there is an advantage that an excellent detection accuracy can be realized by increasing the level with an amplifier or a level conversion means, and the cost is lower than that of the CO sensor.

As a second temperature sensor for detecting the flame temperature, a platinum resistance wire 16B may be used as shown in FIG. In this case, the detection output Eco indicating the CO concentration can be obtained through the bridge circuit, and the hot water supply control can be realized as in the second embodiment.

As a third temperature sensor for detecting the flame temperature, a CdS cell 16C may be used as shown in FIG. The flame temperature can be known from the luminescent color. If the luminescent color is detected by the CdS cell 16C, the output voltage indicates the CO concentration. Thus ,
The C O concentration monitored using the detection output of the CdS cell 16C, it is possible to realize the hot water supply control of the embodiment.

As described above, the points of each processing in the hot water supply control method are listed as follows. a. While monitoring the CO concentration, the supply amount of the combustion gas and the hot water supply amount are interlocked and controlled. b. The number of times the CO concentration exceeds the reference value during a certain period of time after 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. c. The RAM 8 as a storage means includes a reset switch 4
In addition to being cleared by the operation of No. 6, the integrated number is also deleted when the next combustion is normal after abnormal combustion. Even when the fan motor speed is increased, the error count value is returned to the initial value 0. d. The maximum combustion number is set by initializing the fan motor speed. In this embodiment, the combustion is No. 16. e. The fan motor rotation speed is increased stepwise as the cumulative number of abnormal combustion reaches a predetermined number. However, if the rotation speed exceeds the reference upper limit rotation speed, the number of combustions is reduced from the next time. f. 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. g. When the maximum combustion number is reduced, that is, when the value 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 16 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 this 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.

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.

[0086]

As described above, according to the present invention,
The following effects are obtained. a. When the CO concentration exceeds the reference value, the rotation speed of the fan motor is increased, and the rotation speed reaches a certain rotation speed.
Can, by suppressing the fuel及 beauty hot water amount, the controlling by interlocking the combustion operation and the hot water supply operation, while stabilizing the hot water temperature, it is possible to maintain the hot water supply by suppressing only the hot water supply amount. b. Since the rotation speed of the fan motor is increased according to the number of combustions when the CO concentration exceeds the reference value, abnormal combustion can be avoided by compensating for the reduction in the performance of the combustion fan, and the service life of the combustion fan can be extended. And the number of maintenance operations can be reduced. c. 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. d. 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. e. 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. f. When the reduced fuel supply amount is set to the lower limit and the CO concentration exceeds the reference value, the combustion is stopped and the hot water supply is stopped together with the warning, so that the continuation of abnormal combustion can be avoided and higher safety can be achieved. Can be secured.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a hot water supply apparatus of the present invention.

FIG. 2 is a front view showing a main body of the water heater in the first embodiment of the water heater of the present invention.

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

FIG. 4 is a flowchart showing a hot water supply control program which is an embodiment of the hot water supply control method of the present invention.

FIG. 5 is a flowchart showing an initialization program of a combustion operation program as one embodiment of the hot water supply control method of the present invention.

FIG. 6 is a flowchart showing a combustion operation program in the hot water supply control method of the present invention.

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

FIG. 8 is a flowchart showing a combustion operation program following the combustion control program shown in FIGS. 6 and 7.

FIG. 9 is a flowchart showing a hot water supply operation program as one embodiment of the hot water supply control method of the present invention.

FIG. 10 is a flowchart showing a hot water supply operation program following the hot water supply control program shown in FIG. 9;

FIG. 11 is a flowchart showing a water amount control program in the hot water supply operation program shown in FIGS. 9 and 10;

FIG. 12 is a block diagram showing a second embodiment of the hot water supply apparatus of the present invention.

FIG. 13 is a front view showing a main body of the hot water supply apparatus in a second embodiment of the hot water supply apparatus of the present invention.

FIG. 14 is a block diagram showing another control unit in the hot water supply apparatus of the present invention.

FIG. 15 is a block diagram showing another control unit in the hot water supply apparatus of the present invention.

[Explanation of symbols]

 2 Control unit 16 CO sensor (CO detection means) 16A Thermocouple (temperature sensor) 16B Platinum resistance wire (temperature sensor) 16C CdS cell (temperature sensor) 30 Proportional solenoid valve (fuel control valve) 32 Fan motor 44 Water volume control valve 56 Display unit (notification unit) 58 Audio output unit (notification unit) 80 Burner (combustion unit) 82 Heat exchanger 100 Exhaust unit

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Toshiya Tatsumi 201 Nishi-Kashiwara Nitta, Fuji City, Shizuoka Prefecture Inside Takagi Sangyo Co., Ltd. (56) References JP-A-8-35654 (JP, A) JP-A-7- 332667 (JP, A) JP-A-6-82037 (JP, A) JP-A-2-1501919 (JP, A) JP-A-5-26440 (JP, A) JP-A-61-138022 (JP, A) Japanese Utility Model Application Hei 4-129647 (JP, U) Japanese Utility Model Application Hei 5-34441 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F23N 1/02, 1/10 F23N 3/08 F23N 5 / 00,5 / 24

Claims (7)

(57) [Claims] 1. A combustion means for burning fuel, a fan motor for supplying air necessary for combustion of the combustion means, a fuel control valve for regulating supply of fuel to the combustion means, and CO detection means for detecting the CO concentration that occurs, a heat exchanger which is heated by the combustion unit, and quantity control valve for controlling the amount of water supplied to the heat exchanger, the CO that the CO detection means detects When the concentration exceeds the reference value and the combustion continues, the rotation of the fan motor is increased.
The fan motor's speed reaches a certain speed.
The opening degree of the fuel control valve and the water amount control valve
Controlling the fuel supplied to the combustion means
Together, water heater, wherein the Bei Etako a controller for avoiding water supply, a relative to the heat exchanger. 2. The CO detection means is a CO sensor for directly detecting a CO concentration from exhaust gas, a temperature sensor for indirectly detecting a CO concentration from a flame temperature in the combustion means, or a flame sensor in the combustion means. 2. The hot water supply apparatus according to claim 1, wherein the hot water supply apparatus comprises a temperature sensor for indirectly detecting a CO concentration from a luminescent color. 3. 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 certain number of times, the rotation speed of the fan motor is increased at a constant rate from the next combustion. When the number of revolutions reaches a certain number of revolutions or more, the fuel supply amount is reduced from the next combustion, and the amount of water supplied to the heat exchanger heated by the combustion means is suppressed. Hot water supply control method. 4. When the combustion means is performing maximum combustion, and when the time when the CO concentration is equal to or more 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. 4. The method according to claim 3, wherein:
The hot water supply control method described. 5. 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, the combustion means only performs the combustion. 4. The hot water supply control method according to claim 3, wherein the amount of fuel to be supplied to the heat exchanger is reduced, and the amount of water supplied to the heat exchanger is suppressed. 6. The hot water supply control method according to claim 3, wherein a warning is issued when the reduced fuel supply amount is set to a lower limit value. 7. When the reduced fuel supply amount is set to a lower limit value, when the CO concentration in the exhaust exceeds a reference value, water supply to the heat exchanger is stopped together with a warning and a combustion stop. 4. The hot water supply control method according to claim 3, wherein: