JPH0875146A - Burner - Google Patents

Abstract

PURPOSE: To enhance safety by determining that there exists a disconnection or a hole on an exhaust port when a detected air quantity available from an air quantity sensor exceeds a reference air quantity determined in conformity with a rotary speed of a combustion fan available from a rotary speed sensor and suspending the combustion. CONSTITUTION: In a combustion device which is provided with a fan control means 23 which conforms an air quantity detected with an air quantity sensor 13 with a predetermined air quantity, there is provided a memory means 26 which stores data that shows the relation between a speed of rotation of a combustion fan 10 and a reference air quantity available from the speed of rotation in the normal operation time. In the combustion operation, the reference air quantity is read from a memory 26 by a reader 27 in conformity with the speed of rotation of the combustion fan 10 available from the rotation speed sensor 12. In the case when the detected air quantity available from the air quantity sensor 12 exceeds the predetermined air quantity over the reference value, it is determined that there exists a disconnection or a hole in an exhaust port, thereby halting combustion operation of a burner by an operation stop means 28 under control.

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 or a fan heater.

[0002]

2. Description of the Related Art For example, in a water heater, a burner combustion amount required to match a hot water temperature detected by a hot water temperature sensor with a set temperature set by a user is calculated.
The number of revolutions of the combustion fan is controlled to a set number of revolutions that is determined according to the required combustion amount, and a proportional valve provided in the fuel supply passage to the burner according to the required combustion amount or the actual number of revolutions of the combustion fan. What controls the opening is generally known.

In this type of combustion device, the rotation speed of the combustion fan is set on the assumption that the rotation speed of the combustion fan and the amount of air blown from the combustion fan to the burner (air supply amount) always correspond to each other. Although it is controlled to the set rotation speed, in reality, the load of the combustion fan changes due to the clogging of the exhaust stack, the influence of wind, etc., and in such a case, the rotation speed of the combustion fan is the same. However, the actual air flow rate (air supply rate) from the combustion fan to the burner changes. Therefore,
Even if the rotation speed of the combustion fan is controlled to the set rotation speed determined according to the required combustion amount, the actual air flow rate to the burner is not always maintained at an appropriate amount.

Therefore, in this type of combustion device,
The air flow sensor (wind speed sensor) installed in the air passage from the combustion fan to the burner detects the actual air flow to the burner from moment to moment, and sets the air flow rate corresponding to the required combustion amount of the burner. It is also known that the number of revolutions of the combustion fan is controlled (corrected) every moment so that the actual blowing amount matches (see, for example, Japanese Utility Model Publication No. 1-129561 and Japanese Utility Model Publication No. 60-143251). In this type of combustion device, the rotation speed of the combustion fan should be corrected even if the set air flow rate and the actual air flow rate differ due to disconnection or perforation of the exhaust port provided in communication with the combustion chamber. Will be dealt with.

However, even if the combustion operation of the burner is normally performed, the operation is continued even if the exhaust port is disengaged or perforated, which is not preferable.

Therefore, a sensor for detecting a change in air flow is provided inside the exhaust pipe, and the exhaust pipe is monitored for changes due to the change in the air flow inside the exhaust pipe. If there is a change in the air flow inside the exhaust pipe, the combustion operation is stopped. It is known that it does (Actual exploitation 63-
179441).

However, in this type of combustion device, the sensor and the electrical wiring of the sensor must be separately provided in the exhaust pipe, which is disadvantageous in that the cost becomes high.

[0008]

DISCLOSURE OF THE INVENTION The present invention aims to improve such a combustion device, and more specifically, it is possible to detect detachment and perforation of an exhaust port without increasing the cost, and moreover, to the exhaust port. It is an object of the present invention to provide a combustion device capable of performing optimal combustion operation without worrying about disconnection and perforation.

[0009]

In order to achieve the above object, the present invention provides a combustion chamber accommodating a burner, an exhaust port communicating with the combustion chamber, and a combustion fan for blowing combustion air to the burner. An air flow sensor for detecting the air flow from the combustion fan to the burner, a rotation speed sensor for detecting the rotation speed of the combustion fan, and a detection air flow detected by the air flow sensor during the burner operation of the burner. In a combustion device having a fan control means for controlling the number of revolutions of the combustion fan so as to match the set amount of air for obtaining the required amount of combustion, the number of revolutions of the combustion fan and a reference amount of air obtained at normal times by the number of revolutions. And a reference air volume corresponding to the rotation speed of the combustion fan obtained by the rotation speed sensor, which is stored in advance in the storage means. When the detected air volume obtained by the air volume sensor corresponding to the rotational speed of the reading fan and the rotational speed of the combustion fan obtained by the rotational speed sensor exceeds the reference air volume, the operation of stopping the combustion operation of the burner is stopped. And means.

In the operation stopping means in the present invention, the detected air volume obtained by the air volume sensor exceeds the reference air volume corresponding to the rotation speed of the combustion fan obtained by the rotation speed sensor, and the detected air volume is the reference air volume. It is characterized in that the combustion operation of the burner is stopped when a predetermined air volume, which is larger than the air volume, is exceeded.

Further, the operation stopping means in the present invention detects when the detected air volume obtained by the air volume sensor corresponding to the rotation speed of the combustion fan obtained by the rotation speed sensor exceeds the reference air volume. The difference between the air volume and the reference air volume is obtained, and the combustion operation of the burner is stopped when the difference exceeds a predetermined amount.

In the operation stopping means in the present invention, the detected air volume obtained by the air volume sensor corresponding to the rotation speed of the combustion fan obtained by the rotation speed sensor exceeds the reference air volume, and the detected air volume is And stopping the combustion operation of the burner when the rotation speed of the combustion fan controlled by the fan control means so that the reference air flow rate and the reference air flow rate are lower than the rotation speed when the detected air flow rate is obtained. Characterize.

In the operation stopping means in the present invention, the detected air volume obtained by the air volume sensor is higher than the reference air volume corresponding to the rotation speed of the combustion fan obtained by the rotation speed sensor. When the number of revolutions of the combustion fan controlled by the fan control means so as to match the reference air volume is less than the number of revolutions when the detected air volume is obtained, the difference in the number of revolutions causes a change in the number of revolutions. The amount of the burner is determined, and the combustion operation of the burner is stopped when the amount of change exceeds a predetermined amount.

In the combustion apparatus of the present invention, it is preferable that the operation stopping means operates at the beginning of the start of combustion operation. Further, the operation stopping means may be activated during prepurge or ignition of the burner.

[0015]

According to the present invention, when the exhaust port is disengaged or perforated, the detected air volume obtained by the air volume sensor corresponding to the rotation speed of the combustion fan is the rotation speed at the normal time. It is larger than the standard air volume obtained in. Therefore, if the detected air volume at the rotational speed exceeds the reference air volume, it is determined that the exhaust port is disengaged or perforated, and combustion is stopped.

Further, in the present invention, when the detected air volume exceeds a predetermined air volume larger than the reference air volume, or when the difference between the detected air volume and the reference air volume exceeds a predetermined volume, the exhaust port is detached or perforated. Can be determined to have occurred reliably. That is, the cause of the detected air volume becoming larger than the reference air volume is considered to be the variation due to the accuracy of the air volume sensor and the influence of the outside air, in addition to the exhaust opening and the perforation. However, if the combustion is stopped each time a slight influence such as the accuracy of the air volume sensor or the outside air is received, the normal smooth combustion operation will be hindered.
Therefore, when the detected air volume corresponding to the rotational speed exceeds a predetermined air volume larger than the reference air volume by the operation stopping means, or when the difference between the detected air volume and the reference air volume exceeds a predetermined amount, combustion occurs. To stop.

When the detected air volume exceeds the reference air volume, the fan control means reduces the rotation speed of the combustion fan. As a result, when the rotation speed of the combustion fan when the reference air volume is obtained is lower than the rotation speed of the combustion fan when the detected air volume is obtained, the operation stop means causes disconnection or perforation of the exhaust port. To judge. Furthermore, the operation stopping means determines the amount of change in both rotational speeds at this time, and if the amount of change does not exceed a predetermined amount, it is considered that there is a variation due to the accuracy of the air flow sensor and the influence of outside wind, and the operation is continued. If the amount of change exceeds a predetermined amount, the exhaust is surely disengaged or a hole is formed, and the operation is stopped.

Further, the operation stopping means can be operated early in the start of the operation of the combustion apparatus, so that the presence or absence of the exhaust port disconnection or perforation can be judged at an early stage.

If the combustion fan is operated during prepurge or when the burner is ignited, the rotation speed of the combustion fan is kept constant during prepurge and when the burner is ignited. It becomes easier to judge whether or not the exhaust port is detached or perforated as compared with during changing combustion operation.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a first embodiment of the present invention will be described with reference to FIGS.
Will be described with reference to. FIG. 1 is a system configuration diagram of the combustion apparatus of the present embodiment, FIG. 2 is a block configuration diagram of a main part of the combustion apparatus of FIG. 1, and FIG. 3 is a diagram showing the relationship between the rotation speed and the air volume.

The combustion apparatus of this embodiment is a water heater,
In the figure, 1 is a heat exchanger 2 and a burner 3 for heating the heat exchanger 2.
Water heater main body having a built-in water heater, 4 is a water pipe piped through the heat exchanger 2, 5 is a flow sensor for detecting the flow rate of water flowing through the water pipe 4 on the upstream side of the heat exchanger 2, and 6 is heat exchange A temperature sensor for detecting the temperature at which the water flowing through the water pipe 4 flows downstream of the vessel 2, 7 is a gas supply pipe for supplying gas to the burner 3,
Reference numeral 9 denotes an open / close solenoid valve and a gas proportional valve which are sequentially provided in the gas supply pipe 7 from the upstream side thereof, 10 denotes a combustion fan for blowing combustion air to the burner 3, 11 denotes a fan motor for driving the combustion fan 10, and 12 Is a rotation speed sensor composed of a Hall element or the like for detecting the rotation speed of the combustion fan 10,
Reference numeral 13 is an air flow sensor such as a hot-wire air flow sensor arranged in the air passage 14 from the combustion fan 10 to the burner 3, 15 is an operating unit for the user to set hot water, and 16 is an operating unit 1.
5, the set temperature of the hot water and the sensors 5,
A controller for controlling the fan motor 11, the gas proportional valve 9, etc. in accordance with the detection signals of 6, 12, 13; 17 is an igniter for igniting the burner 3; 18 is a combustion state such as whether or not the burner 3 has misfired. It is a frame rod for detection.

The burner 3 and the heat exchanger 2 are housed in a combustion chamber 19 in the water heater main body 1, and the combustion chamber 19
An exhaust port 20 communicates with the upper part of the. The upstream side of the water pipe 4 is connected to a water pipe (not shown), and the downstream side is connected to a hot water tap (not shown) of a kitchen or a bathroom.

The controller 16 is composed of an electronic circuit including a microcomputer and the like.
As shown in FIG. 2, the functional configuration of the controller 16 is as follows: the set temperature given from the operating section 15, the water temperature detected by a water temperature sensor (not shown), and the hot water detected by the temperature sensor 6. A required combustion amount calculation unit 21 for determining the required combustion amount of the burner 3 required to match the hot water discharge temperature with the set temperature from the temperature and the flow rate detected by the flow rate sensor 5 is provided, and is calculated by the calculation unit 21. The air volume setting unit 2 that sets a target air volume (combustion air supply volume) from the combustion fan 10 to the burner 3 corresponding to the required combustion volume
Equipped with 2. Further, the rotation speed of the combustion fan 10 is controlled via the fan motor 11 according to the target air volume (set air volume) set by the air volume setting unit 22, the actual air volume of the combustion fan 10 detected by the air volume sensor 13, and the like. The fan control unit 23 is provided. The fan control unit 23
If the target air volume cannot be obtained when the combustion fan 10 is rotated at the rotation speed set by the air volume setting unit 22, the rotation speed of the combustion fan 10 is corrected according to the air volume detected by the air volume sensor 13. The correction unit 25 is provided. Further, the controller 16 has a storage unit 26 (storage unit) that stores and holds in advance reference data indicating the relationship between the air flow rate and the rotation speed of the combustion fan 10 in a normal state in which the discharge port 20 is not clogged or perforated, and the reference. A reading unit 27 (reading means) for reading the reference air volume corresponding to the rotation speed of the combustion fan 10 from the storage unit 26 based on the data is provided. Further, the controller 16 further determines whether the detected air volume obtained by the air volume sensor 13 corresponding to the rotational speed of the combustion fan 10 detected by the rotational speed sensor 12 is larger than the reference air volume corresponding to the rotational speed. When determining whether or not the detected air volume is larger than the reference air volume, it is determined whether the detected air volume at that time is larger than a predetermined air volume corresponding to the reference air volume previously determined according to a data table or the like. A determination unit 29 for determining, and a valve control unit for controlling the opening of the gas proportional valve 9 according to the rotation speed of the combustion fan 10 detected by the rotation speed sensor 12 and the like, and controlling the gas supply amount to the burner 3. 30 and stop the combustion fan 10 via the fan control unit 23 according to the determination result of the determination unit 29, and shut off the gas supply to the burner 3 via the solenoid valve 8. And a stop command unit 31 allowed to. Here, according to the configuration of the present invention, the determination unit 29 and the stop command unit 31 constitute an operation stop means. The reference data stored in the storage unit 26 is the data shown by the solid line a in FIG.

When the water pipe 4 is started, the controller 16 detects it through the flow rate sensor 5,
In response to the detection, the fan control unit 23 rotationally drives the combustion fan 10 via the fan motor 11 and opens the electromagnetic valve 8 of the gas supply pipe 7 to start the gas supply to the burner 3, and further Burner 3 via igniter 17
Ignites and starts hot water supply operation. Then, at this time, the fan control unit 23 rotates the combustion fan 10 at a rotational speed of about 50% of the maximum rotational speed for a certain period of time before the ignition of the burner 3 to perform the pre-purge, and subsequently, the burner 3 is driven. Gently ignite.

When the water flow through the water pipe 4 is completed, the controller 16 closes the electromagnetic valve 8 to shut off the gas supply to the burner 3, and the fan control section 23 stops the combustion fan 10, Ends the hot water supply operation.
In addition, such a termination operation of the hot water supply operation is performed during the hot water supply operation.
The same is done when the flame rod 18 detects a misfire of the burner 3 or the like.

Next, the operation of the water heater of this embodiment will be described.

At the start of the hot water supply operation, prior to ignition of the burner 3, the fan controller 23 of the controller 16 is started.
Performs pre-purging by rotating the blower fan 10 at a predetermined number of revolutions described later via the fan motor 11, and then the controller 16 opens the solenoid valve 8 to start the gas supply to the burner 3 and at the same time, the igniter. The burner 3 is slowly ignited via 17, and the hot water supply operation by the combustion of the burner 3 is started.

At this time, first, the required combustion amount calculation unit 21 determines the required combustion amount of the burner 3 required to match the hot water discharge temperature detected by the temperature sensor 6 with the set temperature set by the operation unit 15. , The incoming water temperature, the outgoing hot water temperature, the flow rate, and other detection data are obtained from time to time. Furthermore, the air volume setting unit 22 of the controller 16 sets a target air volume from the combustion fan 10 to the burner 3 for obtaining the required combustion amount calculated by the required combustion amount calculation unit 21 according to a predetermined data table or the like.

Next, the controller 16 controls the combustion fan 10 by the fan controller 23. That is,
The fan control unit 23 uses the combustion fan 1 corresponding to the target air volume.
The rotation speed of 0 is set according to a predetermined data table or the like, and the fan motor 11 is set according to the set rotation speed.
The combustion fan 10 is driven via the. At the same time, the rotation speed of the combustion fan 10 is detected by the rotation speed sensor 12.

At this time, the reading unit 27 determines the reference air volume Fa ₀ corresponding to the rotation speed N ₀ obtained by the rotation speed sensor 12 according to the reference data indicated by the solid line a in FIG. 3 of the storage unit 26. The determination unit 29 compares the reference air volume Fa ₀ with the detected air volume obtained by the air volume sensor 13 at this time.

In this case, if the exhaust port 20 is disengaged or perforated, the detected air volume becomes "Fb ₀ "(> Fa ₀ ) as shown in FIG. 3, for example. Then, the determination unit 29
Whether the detection air amount Fb ₀ exceeds a predetermined airflow Fc ₀ is determined by, if the detected airflow Fb ₀ exceeds a predetermined airflow _{Fc 0 (Fb 0> Fc 0} ) , the stop command unit 31 The combustion operation is stopped by. Here, the predetermined air volume Fc ₀ is
The air volume is set in advance so that even if there is a variation due to the accuracy of the air volume sensor 13 or a slight influence of the outside air, it is not mistakenly determined that the exhaust port 20 is detached or perforated. That is, when the detected air volume Fb ₀ exceeds the predetermined air volume Fc ₀ , it can be determined that the exhaust port is detached or a hole is formed. This air flow rate Fc ₀ is shown in FIG.
As shown by, different values are set depending on the reference air volume corresponding to the rotation speed.

Further, in the determination by the determination unit 29, even if the detected air volume Fb ₀ exceeds the reference air volume Fa ₀ , if it is smaller than the predetermined air volume Fc ₀ , the correction unit 25 of the fan control unit 23, The rotation speed of the combustion fan 10 is made lower than the initial rotation speed (set rotation speed) to reduce the actual air volume.
As a result, the rotation speed of the combustion fan 10 is corrected so that the target air volume and the actual air volume match.

At this time, the valve controller 3 of the controller 16
0 controls the opening of the gas proportional valve 9 and controls the gas supply amount to the burner 3 in parallel with the control of the combustion fan 10 as described above. In this case, basically, the valve control unit 30 controls the opening degree of the gas proportional valve 9 according to the actual rotation speed of the combustion fan 10 detected by the rotation speed sensor 12. Therefore, if there is no disconnection or holes in the exhaust port,
Since the rotation speed of the combustion fan 10 and the actual air volume correspond to each other, by controlling the opening of the gas proportional valve 9 according to the rotation speed of the combustion fan 9 as described above,
The gas supply amount to the burner 3 corresponds to the air amount to the burner 3 controlled to the target air amount, and the burner 3 burns with the required combustion amount.

Further, when the load of the combustion fan 10 fluctuates, the rotation speed of the combustion fan 10 is corrected so that the actual air volume and the target air volume match as described above, so the burner 3 The rotation speed of the combustion fan 10 is increased or decreased even if the air volume to the same is the same. Therefore, even if the opening of the gas proportional valve 9 is simply controlled according to the rotation speed of the combustion fan 10, even if the air volume to the burner 3 is the same, the combustion fan 1
The opening degree of the gas proportional valve 9 changes following the number of revolutions of 0, and the amount of gas supplied to the burner 3 changes. Therefore, the valve control unit 30 of the controller 16 corresponds the opening degree of the gas proportional valve 9 to the required combustion amount of the burner 3 according to the air volume detected by the air volume sensor 13 in order to cancel the correction amount of the rotation speed of the combustion fan 10. Let

As described above, the controller 16 not only corrects the rotation speed of the combustion fan 10 when the target air volume is not obtained, but also burns when the exhaust port 20 is disengaged or perforated. The operation can be stopped. Furthermore, since it is not necessary to separately provide a means for detecting detachment or perforation of the exhaust port 20, the cost does not increase.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a block diagram of the essential parts of the apparatus of this embodiment. The combustion apparatus of this embodiment is provided in the water heater of FIG. 1, and the system configuration of the water heater is the same as that of FIG. In the following, when explaining
The same components as those of the water heater of FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The fan control section 23 of the controller 16 of this embodiment has a reference rotation speed (for example, 50% of the maximum rotation speed) for rotating the combustion fan 10 when the prepurge and the burner 3 are slowly ignited. A reference rotation speed setting unit 24 for setting is newly provided.

In the water heater of this embodiment, the fan control section 23 of the controller 16 performs the pre-purge and the slow ignition of the burner 3 at the beginning of the operation, as in the first embodiment described above. At this time, the fan control unit 23 first causes the reference rotation speed setting unit 24 to rotate the combustion fan 10 at the reference rotation speed. At the same time, the air flow sensor 13 detects the air flow sent from the combustion fan 10. The first
In this embodiment, when the combustion fan 10 is rotated at an arbitrary rotation speed, the detected air volume and the reference air volume are compared in magnitude. However, in the present embodiment, the combustion fan 10 has the reference rotation speed. When it is rotated by, the reference air volume corresponding to the reference rotation speed is read from the storage unit 26.
Next, the determination unit 29 compares the detected air volume with the reference air volume in the same manner as in the first embodiment described above, and when the detected air volume is larger than the reference air volume, the detected air volume becomes the reference air volume. It is determined whether or not the corresponding predetermined air volume is exceeded.

When the exhaust port 20 is disengaged or perforated, the determination unit 29 determines that the detected air volume exceeds the predetermined air volume corresponding to the reference air volume, and the result of the determination is determined. Based on this, the stop command unit 31 stops the combustion operation.

Therefore, in this embodiment, it is determined in the initial stage of the combustion operation whether or not the detected air volume exceeds the predetermined air volume determined corresponding to the reference air volume during the pre-purge and the slow ignition of the burner 3. The determination can be made by the determination unit 29, and when the detected air volume exceeds the predetermined air volume, the stop command unit 31 can early stop the combustion operation.

Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a block diagram of the essential parts of the apparatus of this embodiment, and FIG. 6 is a diagram showing the relationship between the rotational speed and the air volume. The combustion apparatus of this embodiment is provided in the water heater of FIG. 1, and since the system configuration of the water heater is the same as that of FIG. 1, it has the same configuration as the water heater of FIG. The same reference numerals are given to the same, and the detailed description thereof will be omitted. In the present embodiment, only the parts different from the respective embodiments will be described in detail.

In the combustion apparatus of this embodiment, the second
The reference rotation speed setting unit 24 for setting the reference rotation speed of the combustion fan 10 (for example, the rotation speed of 50% of the maximum rotation speed) is provided as in the embodiment of FIG.

Then, the controller 16 of this embodiment is
A storage unit 26 (storage unit) that stores and holds in advance reference data indicating the relationship between the air volume and the rotation speed of the combustion fan 10 under normal conditions (when the exhaust port 20 is not disengaged or has no holes), and the reference data. A reading unit 27 (reading means) for reading the reference air amount corresponding to the reference rotation speed from the storage unit 26 based on the above, and is obtained by the air flow sensor 13 when the combustion fan 10 is rotated at the reference rotation speed. And a value obtained by the air volume difference calculation unit 28 for obtaining a difference between the detected air volume and the reference air volume.
A determination unit 29 that determines whether or not the predetermined value is exceeded is provided. In addition, the controller 16 of the present embodiment stops the combustion fan 10 via the fan control unit 23 according to the determination result of the determination unit 29, and also causes the solenoid valve 8 to stop.
And a stop command unit 31 that shuts off the gas supply to the burner 3 via the. The combustion stopping means of the present invention in this embodiment is constituted by the air volume difference calculating unit 28, the determining unit 29, and the stop commanding unit 31.

Next, the operation of the water heater of this embodiment will be described.

As described above, at the start of the hot water supply operation, the controller 16 causes the fan control unit 23 to rotate the combustion fan 10 at the reference rotation speed constantly, and in this state, the prepurge and the burner 3 are slowly rotated. Ignite. At this time, the reading unit 27 gives the reference air volume Fa ₀ corresponding to the reference rotation speed Na ₀ to the air volume difference calculating unit 28 according to the reference data indicated by the solid line c in FIG. The difference calculator 28 calculates the difference between the reference air volume Fa ₀ and the air volume detected by the air volume sensor 13 at this time.

In this case, if the exhaust port 20 is disengaged or perforated, the detected air volume is "Fb ₀ "(> Fa ₀ ) as shown in FIG. The required air flow difference is (Fb ₀ −Fa ₀ ). Then, the air amount difference (Fb ₀ -Fa ₀₎ is whether exceeds a predetermined value by the judging unit 29 is determined, Kazeryousa (Fb ₀ -F
When a ₀ ) exceeds the predetermined value, the stop operation unit 31 stops the combustion operation. Here, the predetermined value is a predetermined value so as not to be erroneously determined to be a detachment or a perforation of the exhaust port 20 even if there is a variation due to the accuracy of the air volume sensor 13 or a slight influence due to the outside air. Is. That is, when the air volume difference (Fb ₀ −Fa ₀ ) exceeds a predetermined value, it can be determined that the exhaust port is disengaged or perforated.

In this embodiment, the storage unit 26
By storing the reference data indicated by the solid line c in FIG. 6, it is possible to obtain the reference air volume corresponding to each reference rotation speed at that time when the reference rotation speed is appropriately determined. ing. However, since the rotation of the combustion fan 10 at the reference rotation speed is performed during the prepurge, basically, the specific reference rotation speed is predetermined. Therefore, as another example, only the reference air volume corresponding to the specific reference rotation speed may be stored in the storage unit 26.

Further, in the determination by the determination unit 29, if the air volume difference (Fb ₀ −Fa ₀ ) is smaller than the predetermined value or the air volume difference (Fb ₀ −Fa ₀ ) is equal to the predetermined value, pre-purge and The slow ignition of the burner 3 is followed by the ignition of the burner 3, and the normal operation is continued while the rotation speed of the combustion fan 10 is corrected so that the target air volume and the actual air volume match.

Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 7 is a block diagram of the essential parts of the apparatus of this embodiment. Also in this embodiment, the system configuration of the water heater is the same as that of FIG. 1, so detailed description of the parts already described in the above embodiments will be omitted.

In the water heater provided with the combustion apparatus of this embodiment, the controller 16 has the required combustion amount calculation unit 21, the air flow rate setting unit 22, the fan control unit 23, and the storage unit, as in the first embodiment. 26, a reading unit 27, a determination unit 29, a valve control unit 30, and a stop command unit 31. The fan control unit 23 is provided with a reference rotation speed setting unit 24 and a correction unit 25, as in the third embodiment.

The controller 16 of the present embodiment is additionally provided with a rotational speed change amount calculation unit 32 for calculating the difference between the reference rotational speed and the corrected rotational speed to obtain the rotational speed change amount. ing. The rotation speed change amount calculation unit 32 includes a reference rotation speed acquisition unit 33 that obtains a reference rotation speed set by the reference rotation speed setting unit 24 during pre-purge, and a rotation speed of the combustion fan 10 by the correction unit 25 during pre-purge. Is corrected, the corrected rotational speed acquisition unit 34 that obtains the corrected detected air volume, and the difference between the rotational speed obtained by the reference rotational speed setting unit 24 and the rotational speed obtained by the corrected rotational speed acquisition unit 34. And a subtraction unit 35 for obtaining Further, the fan control section 23 of the controller 16 of the present embodiment is newly provided with a reference air volume acquisition section 36 that controls the combustion fan 10 at the reference rotation speed and at the same time acquires the reference air volume as the set air volume. . In the present embodiment, the operation stopping means of the present invention is configured by the rotation speed change amount calculation unit 32, the determination unit 29, and the stop command unit 31.

In the water heater of this embodiment, the operation of the required combustion amount calculation unit 21, the air flow rate setting unit 22, the valve control unit 30, and the stop command unit 31 is as described in each of the above embodiments. .

Therefore, the operation of the water heater of this embodiment, which is different from the water heater of the third embodiment, will be described below.

In the water heater of this embodiment, the fan control section 23 of the controller 16 has the same structure as in the above-mentioned embodiments.
The prepurge and the slow ignition of the burner 3 are performed at the beginning of the combustion operation. At this time, first, the fan control unit 23 rotates the combustion fan 10 at the reference rotation speed and gives the reference rotation speed to the reference rotation speed acquisition unit 33 of the rotation speed change amount calculation unit 32. At the same time, the air volume sensor 13 detects the air volume sent from the combustion fan 10 rotated at the reference rotation speed. On the other hand, the reference air volume is read from the reference data stored in the storage section 26 by the reading section 27, and the fan control section 23 obtains the reference air volume as the set air volume by the reference air volume acquisition section 36. By doing this,
The correction unit 25 provided in the fan control unit 23 corrects the rotation speed of the combustion fan 10 so that the detected air volume matches the reference air volume. Then, when the detected air volume matches the reference air volume, the post-correction rotation speed acquisition unit 34 of the rotation speed change amount calculation unit 32 obtains the corrected rotation speed of the combustion fan 10 from the rotation speed sensor 12. According to FIG. 6, the state at this time is as follows when the detected air volume Fb ₀ matches the reference air volume Fa ₀ :
The rotation speed Nb ₀ corresponding to the position (Fb ₀ = Fa ₀ ) in the figure can be obtained by the rotation speed sensor 12.

Next, the subtraction unit 35 of the rotational speed change amount calculation unit 32 calculates the rotational speed change amount from the difference between the reference rotational speed and the corrected rotational speed.

In this case, if the exhaust port 20 is disengaged or perforated, for example, as shown in FIG.
a ₀ rpm Nb ₀ after correction for so (<Na ₀₎ is obtained, the rotation speed of the change amount obtained by the subtraction unit 35 (N
a ₀ −Nb ₀ ). Then, this change amount (Na ₀ −Nb ₀ )
Is judged by the judgment unit 29 whether or not it exceeds a predetermined value, and if the change amount (Na ₀ −Nb ₀ ) exceeds the predetermined value, the stop command unit 31 stops the combustion operation. . Here, the predetermined value is a predetermined rotation so that the exhaust port 20 is not mistakenly determined to be detached or perforated even if there is a variation due to the accuracy of the air flow sensor 13 or a slight influence due to the outside air. The difference value. Therefore, when the amount of change (Na ₀ −Nb ₀ ) exceeds a predetermined value, the exhaust port is disengaged or perforated rather than the variation due to the accuracy of the air volume sensor 13 or the influence of the outside air. Can be determined.

When the change amount (Na ₀ -Nb ₀ ) is smaller than the predetermined value or the change amount (Na ₀ -Nb ₀ ) is 0 in the judgment by the judgment unit 29, the pre-purge and the burner are set. After the slow ignition of 3, the burner 3 is ignited,
The subsequent operation is as described above.

As described above, in this embodiment, the fan control section 23 is used during the prepurge and the slow ignition of the burner 3.
The reference air volume as a set air volume, and the correction unit 25
By correcting the rotation speed of the combustion fan 10 by utilizing the function of, the combustion operation is stopped according to the change amount of the rotation speed at that time. Therefore, similarly to each of the above-described embodiments, the combustion can be stopped only when the exhaust port is reliably disengaged or punctured.

The combustion apparatus of the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications are possible. For example, in each of the above embodiments, the combustion fan 10 at the time of pre-purge and slow ignition of the burner is used.
The operation is performed by determining whether the exhaust port 20 is disengaged or perforated based on the difference between the reference air volume and the detected air volume and the variation in the rotational speed of the combustion fan 10 by utilizing the time when the engine is constantly rotated at a predetermined rotational speed. Although a simple configuration is adopted, the configuration is not limited to such a configuration, and the difference between the reference air volume and the detected air volume at a certain point in the burner combustion operation or the post-purge after the combustion and the rotation speed of the combustion fan 10 are not limited thereto. It goes without saying that a configuration may be adopted in which the deviation or the perforation of the exhaust port 20 is determined from the variation amount of In the third and fourth embodiments described above, the difference between the detected air volume and the reference air volume or the difference between the detected rotation speed and the predetermined rotation speed is calculated, but the difference is calculated only. Alternatively, the ratio of the two may be calculated.

[0060]

As is apparent from the above, according to the present invention, the detected air volume obtained by the air volume sensor when the combustion fan is actually rotated is the reference air volume which should be obtained at the normal rotation speed. Since the combustion operation is stopped by the operation stopping means when the value exceeds the limit, the combustion operation can be automatically stopped when the exhaust port is dislodged or perforated. Moreover, since it is not necessary to separately provide a means for detecting detachment or perforation at the exhaust port, it is possible to prevent an increase in cost.

In the present invention, the operation stop means detects the detected air volume when the detected air volume exceeds a predetermined air volume larger than the reference air volume, and when the difference between the reference air volume and the detected air volume exceeds a predetermined volume. When the rotation speed of the combustion fan controlled by the fan control means so as to match the reference air volume is lower than the rotation speed at which the initially detected air volume is obtained, or the change amount of the rotation speed at that time is obtained. The combustion operation of the burner is stopped in any one of the cases where the change amount exceeds a predetermined amount, so that variations due to the accuracy of the air volume sensor and the influence of the outside air are eliminated,
The combustion operation can be automatically stopped when the exhaust port is dislodged or a hole is formed.

Further, the operation stopping means operates at the initial stage of the start of the combustion operation to judge whether the exhaust port is detached or perforated at an early stage, and the exhaust port is detached or perforated. If so, the combustion operation can be automatically stopped.

Further, the operation stopping means operates at the time of prepurge and at the time of ignition of the burner, so as to judge whether or not the exhaust port is detached or perforated at an early stage, and the above-mentioned operation can be performed easily. Can be done in a configuration.

When the exhaust port does not come off or there is no hole, the fan control means controls the rotation speed of the combustion fan so that the air volume detected by the air volume sensor matches the set air volume corresponding to the required combustion volume of the burner. By doing so, the combustion operation can be smoothly performed.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a combustion apparatus according to a first embodiment of the present invention.

FIG. 2 is a block configuration diagram of a main part of the combustion device of FIG.

FIG. 3 is a diagram showing a relationship between a rotation speed of a combustion fan and an air volume.

FIG. 4 is a block configuration diagram of a main part of a combustion apparatus according to a second embodiment of the present invention.

FIG. 5 is a block configuration diagram of a main part of a combustion apparatus according to a third embodiment of the present invention.

FIG. 6 is a diagram showing the relationship between the rotation speed of a combustion fan and the air volume.

FIG. 7 is a block configuration diagram of a main part of a combustion apparatus according to a fourth embodiment of the present invention.

[Explanation of symbols]

3 ... Burner, 19 ... Combustion chamber, 10 ... Combustion fan, 12 ...
Rotation speed sensor, 13 ... Air volume sensor, 20 ... Exhaust port, 23
... fan control means, 24 ... reference rotation speed setting section (predetermined rotation speed setting means), 26 ... storage section (storage means), 27 ... reading section (reading means), 28 ... air volume difference calculating section (operation stopping means), 29 ... Judgment part (operation stop means), 31 ... Stop command part (operation stop means), 32 ... Rotation speed change amount calculation part (operation stop means).

Claims (7)

[Claims] 1. A combustion chamber accommodating a burner, an exhaust port communicating with the combustion chamber, a combustion fan for blowing combustion air to the burner, and an air volume sensor for detecting an air volume from the combustion fan to the burner. A rotation speed sensor for detecting the rotation speed of the combustion fan, and the combustion fan so that the detected air quantity detected by the air quantity sensor during the combustion operation of the burner matches the set air quantity for obtaining the required combustion quantity of the burner. In a combustion apparatus having a fan control means for controlling the number of revolutions of the storage device, storage means in which data indicating the relationship between the number of revolutions of the combustion fan and a reference air volume obtained at normal times by the number of revolutions is stored in advance, A reading unit for reading from the storage unit a reference air volume corresponding to the rotation speed of the combustion fan obtained by the rotation speed sensor, and a combustion fan obtained by the rotation speed sensor. When detecting air amount obtained by the air volume sensor in response to the rotational speed of the emission exceeds the reference air amount, the combustion apparatus being characterized in that a driving stopping means for stopping the combustion operation of the burner. 2. The operation stop means, the detected air volume obtained by the air volume sensor corresponding to the rotation speed of the combustion fan obtained by the rotation speed sensor exceeds the reference air volume, and the detected air volume is the reference air volume. The combustion apparatus according to claim 1, wherein the combustion operation of the burner is stopped when the amount of air exceeds a predetermined air flow larger than the predetermined value. 3. The operation stop means, when the detected air volume obtained by the air volume sensor corresponding to the rotation speed of the combustion fan obtained by the rotation speed sensor exceeds the reference air volume, the detected air volume and the detected air volume. The combustion apparatus according to claim 1, wherein a difference from the reference air volume is obtained, and the combustion operation of the burner is stopped when the difference exceeds a predetermined amount. 4. The operation stop means has an air flow amount detected by the air flow sensor, which corresponds to the rotation speed of the combustion fan obtained by the rotation speed sensor, exceeds the reference air flow rate, and the detected air flow rate and the reference air flow rate. The combustion operation of the burner is stopped when the number of revolutions of the combustion fan controlled by the fan control unit so as to match the amount of airflow is lower than the number of revolutions when the detected amount of airflow is obtained. The combustion device according to claim 1. 5. The operation stop means controls the number of revolutions of the combustion fan controlled by the fan control means so that the detected air volume and the reference air volume match with each other when the detected air volume is obtained. The combustion apparatus according to claim 1, wherein the combustion amount of the burner is stopped when the amount of change in the number of revolutions is determined from the difference between the two numbers of revolutions, and the amount of change exceeds a predetermined amount. . 6. The operation stopping means is operated at an initial stage of starting a combustion operation.
Combustion device according to paragraph. 7. The operation stopping means is operated during prepurge or ignition of the burner.
The combustion apparatus according to any one of claims 1 to 5.