JPH08210637A - Combustion device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a combustion device capable of checking an abnormality of an air flow sensor. [Composition] A combustion apparatus is constructed in which the combustion air volume supplied from the combustion fan 5 to the burner unit is detected by an air volume sensor 23 and the combustion air volume is controlled based on the detected value.
Before starting the combustion operation, with the combustion fan 5 stopped, the open abnormality determination unit 28 determines that there is no open abnormality inside the sensor of the air flow sensor 23, and then the zero point abnormality determination unit 29.
Judge that there is no zero point abnormality of the air flow sensor 23 by
Next, after the combustion fan 5 is rotated by the short-circuit abnormality determination unit 30, it is determined that there is no short-circuit abnormality in the air volume sensor 23, and in this way, an abnormality check of the air volume sensor 23 is performed to confirm that there is no abnormality. The combustion operation is started later.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device such as a water heater.

[0002]

2. Description of the Related Art FIG. 6 shows a system configuration of a general water heater as a combustion device. In the figure, a water supply pipe 3 of a water supply passage is connected to the inlet side of the hot water heat exchanger 2, and the water supply pipe 3 has a water temperature sensor 10 such as a thermistor for detecting the water temperature and a water supply amount (hot water supply). A flow sensor 9 for detecting the amount of water passing through the heat exchanger) is provided. A hot water supply pipe 4 of a hot water supply passage is connected to the outlet side of the hot water supply heat exchanger 2, and a hot water supply tap 1 is provided at the outlet side of the hot water supply pipe 4. Further, the hot water supply pipe 4 is provided with a water amount control valve 16 and a hot water temperature sensor 11 such as a thermistor for detecting the hot water temperature.

Below the hot-water supply heat exchanger 2, a burner 7 serving as a burner device, and an igniter electrode 1 for igniting the burner 7 are provided.
8, a flame rod electrode 19 for detecting ignition, a combustion fan 5 for supplying and exhausting combustion air to the burner 7, and a fan rotation sensor 21 for detecting the rotation speed of the combustion fan 5 are provided. ing. A nozzle holder 6 is arranged at a gas inlet of the burner 7 with a gas nozzle facing the gas inlet, and a proportional control valve 13 for controlling a gas supply amount to a gas pipe 8 leading to the nozzle holder 6 by an opening amount.
And a former solenoid valve 12 as a gas valve for opening and closing the gas pipeline. The solenoid valves 20a, 20b, 20c are for switching the burner combustion surface.

This type of water heater is provided with a control device 14, and a remote controller 15 is connected to the control device 14, and the remote controller 15 has an operating button (not shown) and a button for setting the hot water temperature. A set temperature display unit for setting the hot water supply temperature is provided. The control device 14 controls the hot water supply operation of the water heater using the sequence program. As shown in FIG. 8, when the hot water tap 1 is opened in step 201,
In step 202, the flow sensor 9 detects the amount of water input, and if the amount of water input exceeds a certain level (more than the minimum operating flow rate), then in step 203, the post fan rotation of the combustion fan 5 is performed. Not that the fan rotation sensor
Check with 21 and then, in step 204, burn fan 5
Is turned on. Then, in step 205, the combustion fan 5
When the rotation of enters into the predetermined rotation area, step 206
Then, the operation according to the ignition sequence is performed. When it is determined in step 203 that the post fan of the combustion fan 5 is rotating, steps 204, 205
Is skipped and the process proceeds to step 206. This is because the combustion fan 5 has a constant rotation speed (for example, 10
By turning it at 00 rpm), the next ignition will be performed immediately.

The operation in accordance with the ignition sequence of step 206 means that the original solenoid valve 12 and the solenoid valve 20a (or 20a, 20a
b or 20a, 20b, 20c) and the proportional control valve 13 are opened to supply gas to the burner 7, and the ignition operation is performed by the igniter electrode 18. Next, the ignition of the burner 7 is confirmed by the frame rod electrode 19, and the feedforward control (without detecting the hot water temperature by the hot water temperature sensor 10 is performed,
Feedback control by PID calculation or the like from a control method of performing combustion according to a preset gas amount supply pattern (the hot water temperature sensor 10 detects the hot water temperature, and the PID calculation is performed so that the hot water temperature approaches the set temperature. That is, the operation of shifting to the method of controlling the valve opening amount of the proportional control valve 13) is performed. The combustion control of the burner 7 is performed by the control operations of the combustion control unit 24 and the air volume control unit 25, as shown in FIG.

The combustion control unit 24 is preliminarily given with relational data between the combustion heat amount (combustion capacity) and the valve opening drive current (gas supply amount) of the proportional control valve 13, and the combustion control unit 24 uses the incoming water temperature sensor. The incoming water temperature is set by receiving information on the incoming water temperature detected by 10, the outgoing hot water temperature detected by the outgoing hot water temperature sensor 11, the flowing water flow rate detected by the flow rate sensor 9, and the set temperature set by the remote controller. The amount of heat required to raise the temperature, that is, the amount of combustion heat that causes the hot water temperature to match the set temperature is calculated, and the proportional control valve 13 is used to obtain the amount of combustion heat.
A valve opening drive current is supplied to the valve to vary the valve opening amount of the proportional control valve 13 to control the gas supply amount to the burner 7.

On the other hand, the air volume control unit 25 applies a command to the fan drive unit 17 to supply the combustion air corresponding to the combustion heat amount obtained by the combustion control unit 24 to the burner 7 to rotate the combustion fan 5. Take control. As data necessary for the rotation control of the combustion fan 5, the air volume control unit 25 is provided with relational data between the fan rotation speed and the fan air volume of the combustion fan 5 as shown in FIG. 9A, for example. Therefore, the air volume control unit 25 estimates the fan air volume from the fan rotation speed detected by the fan rotation sensor 21 based on this relational data and matches the combustion heat quantity as shown in (b) of FIG. The number of revolutions of the fan is controlled so that the target air volume is achieved, and the combustion air is supplied to the burner 7. In this way, the combustion control of the combustion control unit 24 and the air flow control by the air flow control unit 25 are performed in a matched manner, and hot water having a stable set temperature is supplied from the hot water heat exchanger 2 through the hot water supply pipe 4 to the desired hot water supply location. Supplied.

When the hot water tap 1 is closed after the use of hot water is finished, the flow sensor 9 detects the stop of water flow, and the controller 14 receives the detection signal of the water flow stop, and the control device 14 turns on the original solenoid valve 12. The burner 7 is stopped by shutting off.

By the way, in recent years, with the downsizing of combustion devices such as water heaters, the burner 7 tends to burn under high load, and the control of the combustion air supplied to the burner 7 is becoming severe. However, in the conventional water heater as shown in FIG. 6, the air volume control unit 25 performs the air volume control by estimating the fan air volume of the combustion fan 5 from the rotation speed of the combustion fan 5 detected by the fan rotation sensor 21. Because I was going, for example,
The relationship between the fan rotation speed and the fan air flow is shown in FIG. 9A due to various factors such as the influence of back wind from the exhaust port and deterioration of ventilation.
When the state deviates from the state shown in (1), there is a problem that the air volume control cannot be accurately performed, and it is not possible to meet the demand for the severe air volume control.

Therefore, for example, as shown in FIG. 4, a water heater having an air volume sensor 23 for directly or indirectly detecting the air volume of the combustion air supplied from the combustion fan 5 to the burner 7 has been proposed. In this water heater, as shown in the figure, an air volume detection passage 22 is formed by bypassing from the lower side of the burner 7 to the upper side thereof.
An air flow sensor 23 is provided in the. This air volume sensor 23
Is constituted by an appropriate sensor such as a differential pressure sensor or a hot wire type or Kalman vortex type wind speed sensor.
When 23 is configured by a differential pressure sensor, by detecting the difference between the lower side atmospheric pressure and the upper side atmospheric pressure of the burner 7,
The amount of combustion air supplied from the combustion fan 5 to the burner 7 is detected.

The detection signal from the air volume sensor 23 is shown in FIG.
As shown in FIG. 5, the air flow rate control unit 25 is added to the combustion air flow rate control unit 25 based on the combustion air flow rate detected directly or indirectly by the air flow rate sensor 23.
By controlling the rotation of the burner 7 and controlling the amount of combustion air to be supplied to the burner 7, it is possible to control the amount of combustion air very accurately.

[0012]

However, as shown in FIG.
In the water heater as shown in FIG. 5, when the air volume sensor 23 becomes abnormal, it goes without saying that the air volume control section 25 cannot properly control the air volume, but the air volume sensor 23 has been operated so far. No combustion device has been developed that can accurately check for abnormalities.

The present invention has been made to solve the above problems, and an object thereof is to accurately check an air flow sensor, thereby accurately controlling combustion air flow rate control based on the air flow sensor. It is to provide a combustion device that can be used for

[0014]

In order to achieve the above object, the present invention is constructed as follows. That is, the present invention is a combustion device including a burner device, a combustion fan that supplies combustion air to the burner device, and an air volume sensor that detects the amount of combustion air supplied from the combustion fan to the burner device. An open abnormality determination unit that outputs a no open abnormality signal by determining that the output of the air flow sensor is less than a predetermined sensor internal open abnormality determination value when the combustion fan is stopped before starting the combustion operation, and the open abnormality determination unit When an open abnormality no signal is output from, the zero point check operation is performed to determine whether the air volume sensor output is less than the preset no wind reference value, and when it is less than the no wind reference value, a zero point normal signal is output. And a zero point abnormality determining section that rotates the combustion fan when a zero point normality signal is output from the zero point abnormality determining section. Force is configured as characterized by outputting a short-circuit abnormality no signal to determine exceed short check determination value set in advance, provided the short abnormality determination unit to start the combustion operation of the burner apparatus.

In addition, an intermittent hot water discharge mode in which hot water is again discharged before a predetermined time has elapsed after the hot water supply combustion of the burner device has stopped, and a predetermined time has elapsed after the hot water supply combustion has stopped It is a combustion apparatus having a cold start mode for re-ejecting hot water, and has a mode distinction determining section for measuring a time from when hot water is stopped to re-extracting hot water and for distinguishing between a cold start mode and an intermittent hot water mode, It is also a characteristic feature of the present invention to provide a zero point check omission command section for omitting the zero point check operation by the zero point abnormality judging section when the mode distinction judging section judges the intermittent hot water mode.

[0016]

According to the present invention having the above-mentioned structure, before the combustion operation is started, the air flow sensor output is less than the predetermined sensor internal open error determination value by the open error determination section when the combustion fan is stopped and the air flow sensor is opened. After it is determined that there is no abnormality, the zero point abnormality determination unit performs a zero point check operation to determine whether the air volume sensor output is less than a predetermined no wind reference value, and the sensor output is the no wind reference value. If the zero point is judged to be normal and the zero point is judged to be normal, it is judged whether or not the output of the air flow sensor exceeds the predetermined short check judgment value by the short-circuit abnormality judgment section causing the combustion fan to rotate. When the short-circuit check judgment value is exceeded, it is judged that there is no short-circuit abnormality, and the combustion operation of the burner device is started.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same names as those of the device shown in FIGS. 4 to 7 will be assigned the same reference numerals and overlapping description will be omitted. The system configuration of the water heater of the present embodiment is almost the same as the system of the water heater shown in FIG. 4, and the characteristic of this embodiment that is different from the device of FIG. 4 is that the controller 14 has an abnormality in the air flow sensor 23. A specific circuit for checking is constructed, an intermittent hot water discharge mode in which hot water is re-discharged before a predetermined time has elapsed since the hot water supply combustion of the burner 7 was stopped, and a predetermined hot water supply after the hot water supply combustion. It is configured to add a cold start mode in which hot water is again tapped after a lapse of time, and to perform hot water supply combustion operation control separately depending on which of these modes is used for hot tapping again.
The other configuration is similar to that of the device shown in FIG.

FIG. 1 shows a block configuration of a controller 14 of the water heater according to the present embodiment.
Combustion control unit 24, air flow control unit 25, open abnormality determination unit 28,
Zero point abnormality judging section 29, short circuit abnormality judging section 30, mode distinction judging section 33, memory section 34, zero point check omission command section 35
The control device 14 has an error display section.
31 is connected. Further, the open abnormality judging section 28, the zero point abnormality judging section 29, the short abnormality judging section 30, the mode distinction judging section 33, the memory section 34, and the zero point check omission command section 35 are used to check the abnormality of the air volume sensor 23. Circuit is configured.

The control operations of the combustion control unit 24 and the air volume control unit 25 are almost the same as those of the device shown in FIGS. 4 and 5, and the combustion control unit 24 of this embodiment is the same as that of the device of FIG. A different characteristic is that when the circuit that performs an abnormality check of the air volume sensor 23 determines that the air volume sensor 23 is normal, the air volume control by the air volume control unit 25 is performed after receiving the determination result. The control operation of the combustion control unit 24 in FIG. 5 is otherwise the same, and the description thereof will be omitted.

Before the combustion operation is started, the open abnormality determination unit 28 determines that the output of the air flow sensor 23 is less than a predetermined sensor internal open abnormality determination value with the combustion fan 5 stopped. To output
With the combustion fan 5 stopped, it is determined whether the output of the air flow sensor 23 is less than the sensor internal open abnormality determination value such as 3.8 V. When it is determined that the output is less than the sensor internal open abnormality determination value, no open abnormality signal is output. And output
It is added to the zero point abnormality judging section 29. When it is determined that the output of the air volume sensor 23 is equal to or greater than the sensor internal open abnormality determination value, an open abnormality signal is added to the error display section 31. Note that the sensor internal open abnormality determination value of 3.8 V, for example, is given as a voltage value higher than the voltage corresponding to the upper limit of the control range of the normal air volume control by the air volume control unit 25. In the embodiment, the voltage corresponding to the upper limit of the control range of the normal air volume control is 3.5 V, and 3.8 V is given as the sensor internal open abnormality determination value.

The zero point abnormality judging section 29, when the open abnormality no signal is output from the open abnormality judging section 28, judges whether or not the output of the air volume sensor is less than a predetermined no wind reference value. When it is determined to be less than the windless reference value, it outputs a zero point normal signal, receives the open abnormality no signal from the open abnormality determination unit 28, detects the output of the air volume sensor 23, and this output is For example, it is determined whether or not it is less than a predetermined windless reference value such as 1.3 V, and when it is determined that it is less than the windless reference value, a zero point normal signal is output and added to the short-circuit abnormality determination unit 30.

Further, the zero point abnormality judging section 29 is provided with a timer (not shown), and when it judges that the output of the air volume sensor 23 is equal to or higher than the reference value of no wind, the air volume sensor 23 is turned on. When the output is above the windless reference value for a predetermined time such as 10 seconds, it is determined that there is a zero point abnormality of the air flow sensor 23, and a zero point abnormality signal is added to the error display section 31. The windless reference determination value is a voltage value that serves as a reference for determining a windless stable state, and the output of the air volume sensor 23 slightly fluctuates due to the influence of wind of the external environment, but beyond the predetermined time. When a value equal to or higher than the windless reference value is output from the airflow sensor 23, it is determined that the airflow sensor 23 has a zero point abnormality.

When the zero point abnormality determination section 29 outputs the zero point normal signal, the short circuit abnormality determination section 30 rotates the combustion fan 5 and then outputs the output of the air flow sensor 23 to a predetermined short check determination value. It outputs the short-circuit no signal when it judges that the burner 7 is exceeded, and starts the combustion operation of the burner 7. Upon receiving the zero-point normal signal from the zero-point abnormality determination unit 29, the fan drive unit 17 drives the fan. A command signal is applied and the fan drive unit 17 rotates the combustion fan 5. Then, after rotating the combustion fan 5, it is judged whether or not the output of the air flow sensor 23 exceeds a predetermined short check judgment value such as 1.3 V, and when it exceeds the short check judgment value, there is no short circuit abnormality. A signal is output, and in addition to the combustion control unit 24, the combustion control unit 24 starts the combustion operation of the burner 7.

Further, the short-circuit abnormality judging section 32 is provided with a timer (not shown), and when the output of the air volume sensor 23 is below the short-check judgment value after the combustion fan 5 is rotated, Turn on the timer,
Even if a predetermined time such as 10 seconds has passed, the air flow sensor
When the output of 23 does not exceed the short check determination value, it is determined that there is a short circuit abnormality in the air flow sensor 23, a fan drive stop command signal is added to the fan drive unit 17, and the combustion drive 5 is stopped by the fan drive unit 17. At the same time, a short circuit abnormality determination signal is added to the error display section 31.

The error display section 31 receives the respective abnormality determination signals added from the open abnormality determination section 28, the zero point abnormality determination section 29, and the short-circuit abnormality determination section 30, and displays the error of the air flow sensor 23. Yes, when an open abnormality determination signal is added from the open abnormality determination unit 28,
Displays the open abnormality in the sensor, and determines the zero point abnormality
When a zero point abnormality determination signal is applied from 29, the zero point abnormality of the air flow sensor 23 is displayed and the short circuit abnormality determination unit 30
When a short circuit abnormality determination signal is applied from, the short circuit abnormality of the air flow sensor 23 is displayed. Then, the error display unit 31 notifies the user of the water heater of the abnormal state of the air volume sensor 23 by displaying each abnormal state of the air volume sensor 23.

The mode distinction judging section 33 is equipped with a timer (not shown), measures the time from when the hot water is stopped to when it is hot again, and distinguishes between the cold start mode and the intermittent hot water mode of this water heater. It is something to do. Specifically, the mode distinction determination unit 33 measures the time from the time when the hot water is discharged to the time when the hot water is again discharged by a timer, and compares the measured time with the mode distinction determination time that is predetermined in the memory unit 34, When the measurement time is shorter than the mode discrimination determination time, the intermittent hot water mode is determined, and when the measurement time is equal to or longer than the mode discrimination determination time, the cold start mode is determined. When the mode distinction determination unit 33 determines that the water heater has performed re-hot water discharge in the intermittent hot water mode,
The judgment result is added to the zero point check omission command unit 35.

The zero point check omission command section 35 is for omitting the zero point check operation by the zero point abnormality judging section 29 when the mode distinction judging section 33 judges the intermittent hot water mode. In response to the determination result from 33, a zero point check omission command is added to the open abnormality determination unit 28 in the intermittent hot water mode.

When the zero-point check omission command unit 35 receives a zero-point check omission command, the open-abnormality judgment unit 28 outputs less than the predetermined sensor internal open-abnormality judgment value when the output of the air volume sensor 23 is as described above. When it is determined that, instead of adding the open abnormality no signal to the zero point abnormality determination unit 29, it is added to the short circuit abnormality determination unit 30, whereby the zero point check operation by the zero point abnormality determination unit 29 is omitted, The short-circuit abnormality determination unit 30 is allowed to perform a short-circuit abnormality determination operation.

In other words, in the present embodiment, when the mode distinction judging section 33 judges that the cold start mode is set, the open abnormality no signal from the open abnormality judging section 28 is added to the zero point abnormality judging section 29, After the zero-abnormality determination unit 29 has performed the zero-point check operation, the short-circuit abnormality determination unit 30 makes a short-circuit abnormality determination, while the mode distinction determination unit 33 makes a zero-point check when the intermittent hot water mode is determined. A zero-point check omission command is added from the omission command unit 35 to the open error determination unit 28, and the open error no signal from the open error determination unit 28 is directly added to the short error determination unit 30 and the zero error determination unit 29 is used. The short-circuit abnormality determination unit 30 determines the short-circuit abnormality without performing the zero-point check operation.

The hot water discharge mode at this time is to use the hot water from the previous time in the heat exchanger 2 so that the hot water is discharged immediately. For this reason, the combustion fan 5 is stopped and the post fan is run for a short period of time, for example, 0.5 seconds, so that the hot water is not blocked last time.
The combustion fan 5 is stopped.

The present embodiment is configured as described above,
Next, the abnormality check operation of the air volume sensor 23, which is a characteristic of the present embodiment, will be described based on the flowchart shown in FIG. Also in this embodiment, the hot water supply operation of the water heater is controlled by the control device.
14 is performed using a sequence program, and as shown in FIG. 8, after the hot water tap 1 is opened,
When it is confirmed in step 202 of FIG. 8 that the water is more than the minimum operating flow rate, in this embodiment, the output of the air volume sensor 23 is determined by the open abnormality determination unit 28 as the sensor internal open abnormality determination value in step 102 of FIG. If the output of the air flow sensor 23 is 3.8 V or more, it is determined in step 103 that there is an open abnormality in the sensor, and the open abnormality determination section 28 outputs an open abnormality signal to the error display section. In addition to 31, the error display unit 31 displays an open abnormality in the sensor. On the other hand, in step 102,
When it is determined that the output of the air flow sensor 23 is less than 3.8 V, the open abnormality determination section 28 outputs an open abnormality no signal and the routine proceeds to step 104.

In step 104, the mode distinction judging section 33 judges whether the water heater is in the cold start mode or the intermittent hot water discharge mode. When it is judged to be the cold start mode, the open abnormality judging section 28 judges that the open abnormality has occurred. The no signal is added to the zero point abnormality judging section 29, and the routine proceeds to step 105. On the other hand, when it is determined in step 104 that the water heater is in the intermittent hot water supply mode, in step 108, the zero point check omission command unit 35 adds a zero point check operation omission command to the open abnormality determination unit 28. The no open abnormality signal output from the open abnormality determination unit 28 is added to the short abnormality determination unit 30, and the step 10
Go to 9.

In step 105, the zero point abnormality judging section 29 outputs the output of the air volume sensor 23 to 1.3 as the no-wind reference value.
It is judged whether or not it is less than V, and the output of the air flow sensor 23 is 1.3 V.
When it is determined that the value is less than zero, the zero point abnormality determination unit 29 adds a zero point normal signal to the short circuit abnormality determination unit 30. On the other hand, when it is determined in step 105 that the output of the air flow sensor 23 is 1.3 V or more, the timer (not shown) of the zero point abnormality determination unit 29 is turned on, and in step 106, the air flow sensor output is 1.3 V or more. When it is determined that the time period of 10 seconds has elapsed, the zero point abnormality of the air flow sensor 23 is determined in step 107. Then, a zero point abnormality determination signal is applied from the zero point abnormality determination section 29 to the error display section 31, and the error display section 31 displays the zero point abnormality of the air volume sensor 23.

In step 109, the short-circuit abnormality determination unit 30
As a result, a fan drive command is applied to the fan drive unit 17, and the combustion fan 5 is rotated. Then, after rotating the combustion fan 5, in step 110, the short-circuit abnormality determination unit
It is determined by 30 whether or not the output of the air volume sensor 23 exceeds 1.3 V as the short-circuit check determination value. When it is determined that the output of the air volume sensor 23 exceeds 1.3 V, the short-circuit abnormality determination unit 30 causes a short circuit. An abnormal no signal is output and applied to the combustion control unit 24, and in step 111, the combustion control unit 24 follows the ignition sequence in accordance with the burner 7
Combustion operation is started.

The burner 7 according to this ignition sequence
8 starts the combustion operation and controls the combustion operation in the steps shown in FIG.
Although the operation is substantially similar to the operation according to the ignition sequence in 206, in the present embodiment, the fan rotational speed check operation during the air volume control is performed as shown in steps 113 to 116. In the water heater of this embodiment, during the combustion operation,
In a normal state, the rotation speed of the combustion fan 5 is about 3300 rpm even when maximum combustion is performed with the maximum air volume. However, for example, when foreign matter enters the exhaust port or the fins are clogged, the rotation speed of the combustion fan 5 greatly exceeds 3300 rpm in order to keep the air volume constant. Therefore, in such a case, an abnormality such as the mixing of foreign matter into the exhaust port is considered, so in this embodiment, in step 116, the rotation speed of the combustion fan 5 is changed.
If it is determined in step 117 that the rotation speed is 4500 rpm or more for 10 seconds, it is determined in step 117 that the combustion operation is stopped, and then in step 119, an error judgment is performed. As a result, the danger of continuing combustion operation in an abnormal state is suppressed.

When the short-circuit abnormality determination unit 30 determines that the output of the air flow sensor 23 is 1.3 V or less in step 110, a timer (not shown) of the short-circuit abnormality determination unit 30 is turned on, At step 112, it is judged whether or not a predetermined time such as 10 seconds elapses while the output of the air volume sensor 23 is 1.3 V or less, and even after 10 seconds, the air volume sensor 23
When the output of 23 does not exceed 1.3 V, step 113
Then, a fan drive stop command signal is applied from the short-circuit abnormality determination section 30 to the fan drive section 17 to stop the combustion fan 5, and in step 114, the short-circuit abnormality determination section 30 outputs an error display section.
A short circuit abnormality signal is added to 31, and the error display section 31 displays a short circuit abnormality of the air flow sensor 23.

When it is determined in step 104 that the water heater is in the intermittent hot water supply mode, and in step 108 that the zero point check operation omission command is applied to the open abnormality determination part 28, steps 105 to 107 are executed. The zero-point check operation of step 10 is omitted, the combustion fan 5 is rotated in step 109, and steps 110 to 11 are performed.
The short-circuit abnormality check of the air flow sensor 23 will be performed up to 4.

According to the present embodiment, by the above operation, the sensor internal open abnormality check, the zero point check, and the short-circuit abnormality check are performed before the burner 7 starts hot water combustion. After it is confirmed by the abnormality check of the sensor 23 that the air volume sensor 23 is normal, the burner 7 starts hot water supply and combustion.
Since the combustion air is supplied from the combustion fan 5 to the burner 7 on the basis of the output of the air conditioner to perform the combustion operation, the air flow control does not become inaccurate due to the abnormality of the air flow sensor 23. It is possible to precisely control the amount of combustion air, and it is possible to perform safe and accurate combustion operation.

Further, FIG. 3 shows the output of the air flow sensor 23, the opening and closing of the hot water tap 1, and the voltage applied to the fan motor of the combustion fan 5 when the hot water supply device is performing hot water supply combustion operation in the intermittent mode. However, as is clear from the figure,
When the hot-water tap 1 is closed and the hot-burning of the burner 7 is stopped (A in the figure) and the hot-water re-emergence (B in the figure) is short, the output of the air volume sensor is a no-air reference value when the hot water is re-emitted. 1.3
It may not drop below V (C in the figure). for that reason,
As described above, when the zero-point check operation is performed at the time of hot-water tapping again when the time from the hot-water supply combustion stop to the hot-water tapping is short, the operation from steps 105 to 106 of FIG. 2 causes the operation shown in FIG. As described above, it takes a check time from the start of the re-hot water discharge to the start of the rotation of the fan, which delays the start of the hot water supply and combustion of the burner 7.

However, in the present embodiment, the mode distinction judging section 33 is provided to distinguish whether the hot water heater has performed the hot water supply combustion in the cold start mode or the intermittent hot water supply mode and restarts the hot water supply combustion stop. By omitting the zero-point check operation in the intermittent hot water supply mode in which the time until hot water is short is provided, it becomes possible to prevent the delay in the start of hot water supply combustion and erroneous determination of zero point abnormality, as shown in FIG. 3 (b). As described above, the hot air supply combustion of the burner 7 can be started by rotating the combustion fan 5 immediately after the hot water is again discharged.

Further, according to the present embodiment, the open abnormality judging section 28, the zero point abnormality judging section 29, and the short abnormality judging section 30.
Thus, when an abnormality of the air volume sensor 23 is determined, the user of the water heater quickly and abnormally displays the abnormal state by the error display unit 31, and
It is possible to know the information accurately, and it is possible to prompt appropriate measures such as repair of the air flow sensor 23.

The present invention is not limited to the above-mentioned embodiment, and various embodiments can be adopted. For example, in the above-described embodiment, the sensor internal open abnormality determination value is 3.8 V, the windless reference value is 1.3 V, and the short check determination value is 1.3 V. However, each of these determination values is not limited to these numerical values. Instead, it is set appropriately. Further, each of these judgment values and reference values are not necessarily given by voltage values.For example, these judgment values and reference values are given as current values, and the air flow sensor output is detected by the current value to obtain the detected current value. You can compare.

Further, in the above embodiment, the error display section 31 is provided, and when the open abnormality judging section 28, the zero point abnormality judging section 29, and the short abnormality judging section 30 judge the abnormality of the air flow sensor 23, Although each abnormal state is displayed separately, the error display unit 31 does not always show the air volume sensor.
Each abnormal state of 23 is not necessarily displayed separately, and for the moment, it may be possible to display only that the air volume sensor 23 has an abnormality.

Further, instead of providing the error display section 31, an error notification device may be provided for notifying that the air volume sensor 23 has an abnormality or a state of abnormality by a buzzer or the like. Device and error display
31 can be omitted. However, by providing an error display unit 31 or the like to notify the user of the water heater of the abnormality of the air volume sensor 23, it is possible to promptly prompt a countermeasure such as repair of the air volume sensor 23. It is desirable to provide a notification device.

Further, in the above-described embodiment, the water heater is a combustion device having an intermittent hot water discharge mode and a cold start mode, and the control device 14 is provided with the mode distinction judging portion 33. Can be omitted.
However, if a cold start mode and an intermittent hot water mode are distinguished by providing a mode distinction determination unit 33 and the zero point check operation is omitted when it is determined to be the intermittent hot water mode, re-hot water in the intermittent hot water mode At times, it is possible to prevent delays in hot water supply combustion start and erroneous determination of zero point abnormality due to the air volume sensor output not falling below the standard value for no wind. It is preferable to provide a mode distinction determination unit.

Further, in the above embodiment, a single-function water heater having an intermittent hot water supply mode and a cold start mode (a water heater having only a hot water supply function) has been described.
It is not limited to a combustion device that performs combustion operation by distinguishing between the intermittent hot water mode and the cold start mode, and it is also applied to various combustion devices other than the combined water heater and the water heater that have both the hot water supply function and the reheating function. It is something.

[0047]

According to the present invention, before the combustion operation is started, it is judged that the output of the air volume sensor is less than the sensor internal open abnormality determination value while the combustion fan is stopped, and there is no open abnormality of the air volume sensor. Then, by the zero point check operation, it was judged that the output of the air volume sensor was less than the reference value for no airflow, and it was confirmed that there was no zero point abnormality of the air volume sensor, and the combustion fan was rotated in this state. After that, in order to confirm that the output of the air volume sensor exceeds the short-circuit check judgment value and to confirm that there is no short-circuit abnormality of the air volume sensor, it is possible to reliably perform the abnormality check of the air volume sensor before starting the combustion operation. . In this way, the air flow sensor is checked for abnormalities, and after it is confirmed that there is no abnormality, the combustion air supplied from the combustion fan to the burner device is detected by the air flow sensor in order to start the combustion operation of the burner device. It is possible to accurately control the air flow rate of the combustion fan based on the air flow rate, so that safe and accurate combustion operation control can be performed.

In addition, an intermittent hot water discharge mode in which hot water is again discharged before a predetermined time has elapsed after the hot water supply combustion of the burner device has stopped, and a hot water discharge is performed again after a predetermined time has elapsed after the hot water supply and combustion. It is a combustion apparatus having a cold start mode for performing, and has a mode distinction determination unit that measures the time from when hot water is stopped to when hot water is re-exposed and distinguishes between the cold start mode and the intermittent hot water discharge mode. According to the present invention, which is provided with a zero point check omission command section that causes the zero point abnormality determination section to omit the zero point check operation when the determination section determines the intermittent hot water mode, even in the intermittent hot water mode, Even if the output of the air flow sensor does not fall below the standard value for no wind, the zero-point check operation is performed in that state to delay the start of hot water supply combustion or to make an error in the zero-point error. It becomes possible to prevent disconnection, by rotating the combustion fan immediately after re-tapping, it is possible to start the water heater combustion quickly.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main configuration of an embodiment of a combustion apparatus according to the present invention.

FIG. 2 is a flowchart showing the operation of the above embodiment.

FIG. 3 is an explanatory diagram showing a difference in a combustion operation start timing between a case where a zero-point check operation is performed and a case where the hot water supply device is omitted when performing hot water discharge again in the intermittent hot water supply mode.

FIG. 4 is a system configuration diagram of a water heater including an air flow sensor.

FIG. 5 is an explanatory diagram showing a main part configuration of a controller of a water heater having a conventional air flow sensor.

FIG. 6 is a system configuration diagram of a water heater without an air flow sensor.

FIG. 7 is an explanatory diagram showing a main part configuration of a control unit of a water heater having no conventional air flow sensor.

FIG. 8 is a flowchart showing a hot water supply combustion start operation of a conventional water heater.

FIG. 9 is a graph showing a relationship (a) between a fan rotation speed of a combustion fan and a fan air volume, and a relationship (b) between a combustion heat quantity and a target air volume.

[Explanation of symbols]

 14 Control device 23 Air flow sensor 28 Open abnormality determination unit 29 Zero point abnormality determination unit 30 Short circuit abnormality determination unit 33 Mode distinction determination unit 35 Zero point check omission command unit

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[Procedure amendment]

[Submission date] March 14, 1995

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

FIG.

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 5]

[Figure 6]

[Figure 7]

[Figure 8]

[Figure 9]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Gohisa Mashima, 3-4 Fukamidai, Yamato City, Kanagawa Prefecture, Gaster Co., Ltd. (72) Inventor: Ryo Izumisawa, 3-4 Fukamidai, Yamato City, Kanagawa Prefecture, Gaster Co., Ltd. (72) Inventor Kikuo Okamoto, 3-4 Fukamidai, Yamato City, Kanagawa Prefecture, inside Gaster Co., Ltd.

Claims (2)

[Claims] 1. A combustion device comprising a burner device, a combustion fan for supplying combustion air to the burner device, and an air volume sensor for detecting an amount of combustion air supplied from the combustion fan to the burner device. Before the start of operation, the open abnormality judging section that judges that the air flow sensor output is less than the predetermined sensor internal open abnormality judging value when the combustion fan is stopped and outputs an open abnormality no signal, and the open abnormality judging section When an open abnormality no signal is output, a zero point check operation is performed to determine whether the air volume sensor output is less than a preset no wind reference value, and when it is less than the no wind reference value, a zero point normal signal is output. When the zero point abnormality determination section outputs a zero point normality signal from the zero point abnormality determination section, the output of the air flow sensor is predicted after rotating the combustion fan. The combustion device is characterized in that a short circuit abnormality determination unit is provided for determining that the predetermined short circuit check threshold value has been exceeded and outputting a short circuit abnormal signal to start the combustion operation of the burner device. 2. An intermittent hot water discharge mode in which hot water is re-discharged before a predetermined time has elapsed after the hot water supply combustion of the burner device has stopped, and a hot water supply combustion is restarted after a predetermined time has elapsed after the hot water supply combustion was stopped. A combustor having a cold start mode for tapping hot water, having a mode distinction judging section for measuring the time from when hot water is stopped to being tapped again to make a distinction between a cold start mode and an intermittent tapping mode, The combustion apparatus according to claim 1, further comprising a zero-point check omission command unit that causes the zero-point abnormality determination unit to omit the zero-point check operation when the mode distinction determination unit determines the intermittent hot water mode.