KR0131841B1 - Blower control device of combustion machine - Google Patents

Abstract

a measuring means measuring the variation rate to time in the output level of an air speed sensor when the blowing fan starts to rotate from the stop state; and the correction means correcting a sensed variation rate to accord to the normal air speed when a sensed variation ratio is lower than the standard value; is disclosed. The rotation number of a blowing fan is controlled to a target speed by a fan control means. Thereby, it is possible to control the air speed regardless of the load variation of the blowing fan.

Description

Blowing controller of combustion equipment

1 is a system configuration diagram of a hot water heater provided with an example of the blow control device of the first embodiment of the present invention.

2 is a block diagram of main parts of the hot water heater shown in FIG.

3 is a diagram for explaining the operation of the water heater shown in FIG.

4 is a diagram for explaining the operation of the water heater shown in FIG.

5 is a diagram for explaining the operation of the hot water heater shown in FIG.

6 is a block diagram of main parts of a hot water heater provided with an example of a blow control device of a second embodiment of the present invention.

7 is a diagram for explaining the operation of the hot water heater shown in FIG.

8 is a diagram for explaining the operation of the water heater shown in FIG.

9 is a diagram for explaining the operation of the hot water heater shown in FIG.

FIG. 10 is a circuit configuration diagram of an example of a wind speed sensor used in the hot water heater of FIGS. 1 and 6. FIG.

11 is a diagram showing the output characteristics of the wind speed sensor shown in FIG.

* Explanation of symbols for main parts of the drawings

10: blower fan 13: wind speed sensor

22: change rate measurement unit (measurement means) 24: correction unit (correction means)

30: fan control means 31: alarm means

32: operation stop means 34: operation prohibition means

The present invention relates to a blow control device for a combustion device that controls the air flow rate or wind speed using a wind speed sensor.

For example, in a combustion device such as a hot water heater or a fan heater, a wind speed sensor is disposed in a blower passage from a blower fan for blowing combustion air to a burner, and the wind speed sensor detects the actual air flow to the burner. It is known to control the number of revolutions of the blower fan so that the actual amount of extinguishment matches the target amount of air corresponding to the required amount of combustion of the burner. (See, for example, Japanese Patent Application Laid-Open No. H11-129561 and Japanese Utility Model Publication No. 60-143251).

As the wind speed sensor, for example, a hot wire wind speed sensor is known as shown in FIG.

This heat-wire-type wind speed sensor uses a pair of fixed resistances, a basic resistance (a, b), a resistance heating element (c) made of, for example, a platinum wire, and a temperature compensation using a platinum wire like the heating element (c). A bridge circuit (e) constituted by the melt resistance (d) is provided, and the resistance heating element (c) and the temperature compensation resistor (d) are disposed in the air passage when detecting the air volume or the wind speed. The wind speed sensor feeds the bridge circuit (e) through a feedback amplifier (h) configured using an operational amplifier (f) or a transistor (g), whereby the exothermic temperature of the resistance heating element (c) is always constant with respect to the ambient temperature. A current flows through the resistance heating element c so as to be as high as the temperature, and in this state, the voltage generated at the output point P (feeding portion to the bridge circuit e) of the bridge circuit e is converted into a resistance heating element ( The detection signal indicating the wind speed at the position c) is output through the amplifier i.

In such a wind speed sensor, when the wind speed at the position of the resistance heating element c increases, the heating element c becomes cold, so that the heating temperature of the heating element c is set to a temperature higher by a predetermined temperature relative to the ambient temperature. To this end, the feed current to the bridge circuit e is increased by the feedback amplifier h. Therefore, the output level of the amplifier i increases, and the output level thereof corresponds to the wind speed, and the wind speed can be detected by the output level of the amplifier i. In addition, since the air volume at the position of the resistance heating element c is multiplied by the cross-sectional area of the air passage, the air volume can be detected by the output level of the amplifier i. In addition, the temperature compensation resistor (d) is for the temperature of the resistance heating element (c) to be higher than the ambient temperature by a certain temperature even if the ambient temperature changes, and by providing this temperature compensation resistance (d) If this is constant, even if the ambient temperature (wind temperature) changes, the output level of the wind speed sensor (output level of the amplifier i) becomes constant.

In addition, in the wind speed sensor of FIG. 10, the output level of the wind speed sensor is increased as the wind speed increases. However, by installing an inverting amplifier in the circuit, the output level of the wind speed sensor decreases as the wind speed increases. There is a case.

In the combustor provided with such a wind speed sensor, even if the load of the blower fan changes due to the effect of exhaust clogging or air clogging, the air volume or wind speed detected by the wind speed sensor corresponds to the combustion amount of the burner. Alternatively, the desired amount of air can be supplied to the burner by controlling the number of rotations of the blower fan to be the wind speed. By the way, in order to correctly control the air flow rate or the wind speed of the blowing fan using the wind speed sensor as described above, it is assumed that the characteristics of the output level with respect to the wind speed of the wind speed sensor are maintained at the originally set characteristics, but the resistance heating element Since the heat generator is disposed in a state exposed to the passage, dust or the like is easily attached to the heating element. When dust or the like is attached to the resistance heating element, the heat capacity is changed or the sensitivity is deteriorated. Therefore, the wind speed sensor is deteriorated, and the characteristics of the output level for this wind speed or air volume change compared with those originally set. For example, in the wind speed sensor of FIG. 10, the output characteristics of the wind speed sensor were characteristics as shown by the solid line in FIG. 11 under normal conditions, but when dust or the like adhered to the resistance heating element C, the broken line in FIG. As shown by the figure, the characteristics change, and the output level at various wind speeds or air flows decreases as the dust or the like progresses, as compared with the normal case of the original. Therefore, when dust or the like is attached to the resistance heating element of the wind speed sensor as described above, it is impossible to correctly detect the air flow rate or the wind speed of the blowing fan, resulting in inaccurate control of the blowing fan.

Therefore, in order to solve such a problem, for example, disclosed in Japanese Patent Laid-Open No. H3-286919, the output characteristics of the wind speed sensor are memorized at the start of the blower fan (prepage). In addition, after the next operation, the wind sensor detects the output characteristics of the wind speed sensor at the time of prepurging, and controls the blower fan by correcting the output of the wind speed sensor by the deviation of these output characteristics. Proper control of the blower fan can be carried out irrespective of deterioration caused by dust and dirt.

However, in the publication disclosed in this publication, when detecting the output characteristics of the wind speed sensor, the output level of the wind speed sensor with respect to various values of the fan drive voltage is provided on the premise that the air volume of the blowing fan corresponding to the fan driving voltage is obtained. Since the output characteristics of the wind speed sensor were to be identified, the following problems occurred.

In other words, if the load of the blower fan is changed due to the clogging of the exhaust or the air supply, the actual air volume changes even with the same fan driving voltage. Therefore, even when the output characteristics of the wind speed sensor are maintained in the original normal state, the output level of the wind speed sensor with respect to the fan driving voltage changes compared with the original output level, and the output characteristic of the wind speed sensor is incorrectly detected. . In such a case, even though the wind speed sensor is normal, the output level of the wind speed sensor is corrected, and it is impossible to perform proper air volume control of the blowing fan.

An object of the present invention is to improve a blow control device for a combustion device using a wind speed sensor. Even if dust or the like is attached to the resistance heating element of the wind speed sensor, the output characteristics of the wind speed sensor may be changed. The air flow rate or wind speed of the blower fan can be properly grasped at the output level of the wind speed sensor without being affected by load fluctuations of the blower fan. It is an object to provide a device.

MEANS TO SOLVE THE PROBLEM The present inventors discovered various things about the output of the wind speed sensor which the combustion apparatuses, such as a hot water heater, were equipped in the blow control apparatus, and discovered the following matters.

That is, for example, in the case of using the wind speed sensor of FIG. 10 in a hot water heater, when the number of revolutions of the blower fan is raised from 0 (stop state) to a predetermined predetermined speed NO as shown in FIG. If the sensor is normal (with no dust or the like attached to the resistance heating element), and the load of the blower fan without exhaust clogging is normal, if the wind speed sensor is normal and exhaust clogging occurs, and if the resistance heating element of the wind speed sensor is The output level of the wind speed sensor is changed as shown in FIG. 4 when dust or the like is attached and there is no exhaust clogging, or when dust or the like is attached to the resistance heating element of the wind speed sensor.

In more detail, in the case where the wind speed sensor is normal, the output level of the wind speed sensor finally reaches the predetermined level of the blower fan, even when the exhaust clogging or the like occurs as shown by the solid line in FIG. As the number of revolutions of the blower fan increases to a level corresponding to the amount of wind or the wind speed (hereinafter, collectively referred to simply as the amount of wind) obtained at the rotational speed NO, the rate of increase is increased at about the same temporal rate of change. In addition, when exhaust clogging or the like occurs, the actual air volume obtained at the predetermined rotation speed NO is smaller than that at other times, so that the output level of the wind speed sensor finally obtained corresponding to the predetermined rotation speed NO is decreased. .

On the other hand, when dust or the like is attached to the resistance heating element of the wind speed sensor, as shown by the broken line in FIG. 4, the output level of the wind speed sensor is equal to the above-described level even if the exhaust blockage occurs or not. In the same manner as in the case, as the fan speed increases, the fan speed increases to a level corresponding to the air volume finally obtained at the predetermined rotation speed NO of the blow fan (this is smaller than when the wind speed sensor is normal). This temporal rate of change is smaller than when the wind speed sensor is normal. This is because the resistance heating element of the wind speed sensor cools down as the air flow increases due to the increase in the number of revolutions of the blower fan.However, when dust or the like is attached to the resistance heating element, it is difficult to cool compared to the case where it is not. It is thought that this is because the sensitivity is reduced.

In addition, the temporal change rate decreases as the adhesion of dust or the like to the resistance heating element increases and the change in the output characteristic of the wind speed sensor increases. As described above, the tendency of the temporal change rate of the output level of the wind speed sensor to be reduced due to the attachment of dust or the like is the same as the case of using the wind speed sensor configured as the wind speed sensor so that the output level becomes smaller with the increase of the air volume.

In view of the above, the temporal rate of change of the output level of the wind speed sensor when the blower fan is started in the stationary state and the rotation speed is increased is not affected by the exhaust clogging and the like, and dust or the like adheres to the resistance heating element of the wind speed sensor. It can be said that it depends only on the state of the connection. Therefore, when the temporal change rate is measured, the degree of change in the normal case of the output characteristics of the wind speed sensor due to the adhesion state of the dust to the resistance heating element or the adhesion of the dust to the resistance heating element with or without exhaust clogging or the like is measured. It is thought that according to this, the actual air volume of a blowing fan can be grasped | ascertained appropriately at the output level of a wind speed sensor, with or without exhaust clogging etc. accordingly.

Then, for example, in the case where the wind speed sensor of FIG. 10 is used, if the blowing fan is stopped while the rotation speed of the blowing fan is controlled to the predetermined rotation speed NO shown in FIG. 7, the wind speed sensor is normal. If the load of the blower fan is normal without exhaust clogging, the wind speed sensor is normal and exhaust clogging occurs, the dust is attached to the resistance heating element of the wind speed sensor, and there is no exhaust clogging. In the case where dust or the like adheres to the heating element and exhaust clogging occurs, the output level of the wind speed sensor changes as shown in FIG.

In more detail, in the case where the wind speed sensor is normal, the output level of the wind speed sensor is set at the predetermined rotation speed N0 even when the exhaust clogging or the like occurs as shown by the solid line in FIG. As the number of revolutions of the blower fan decreases from the level corresponding to the air volume obtained, the rate decreases at almost the same temporal rate of change.

On the other hand, when dust or the like is attached to the resistance heating element of the wind speed sensor, as shown by broken lines in Fig. 8, the output level of the wind speed sensor may be the same as described above even if the exhaust clogging occurs or not. As in the case, the rate of change decreases at almost the same temporal rate of change, but the temporal rate of change is larger than when the wind speed sensor is normal. The reason can be considered as follows. That is, since the heat generating temperature of the resistance heating element of the wind speed sensor is energized so that the temperature is higher than the ambient temperature by a certain temperature, in the state where it is blown by the blowing fan to the resistance heating element of the wind speed sensor, the resistance heating element Since heat is taken away, the amount of electricity supplied to the resistance heating element is larger than that at no wind. When dust or the like is attached to the resistance heating element, the heat capacity thereof is increased, so that heat dissipation is relatively difficult as compared with the resistance heating element without adhesion of dust or the like. Therefore, when the blower fan is stopped in such a state, the heat taken away by the blowing drops sharply, so that the resistance heating element with dust or the like tends to increase in temperature as compared with the resistance heating element without dust or the like. Therefore, the wind speed sensor rapidly reduces the amount of current supplied to the resistance heating element with dust, so that the heat generation temperature is higher than the ambient temperature by a certain temperature, so that the output level of the wind speed sensor is lower than that without dust or the like. It can be seen as a sharp decline.

In addition, the temporal change rate increases as the adhesion of dust and the like to the resistance heating element increases and the change in the output characteristic of the wind speed sensor increases. Further, as described above, the tendency of the temporal change rate of the output level of the wind speed sensor to be increased due to the attachment of dust or the like is the same as the case of using the wind speed sensor configured as the wind speed sensor so that the output level decreases with the increase of the air volume.

In the above matters, the temporal rate of change of the output level of the wind speed sensor when the blower fan is stopped at a predetermined rotational speed is not affected by exhaust clogging, but only in a state where dust or the like is attached to the resistance heating element of the wind speed sensor. It can be said to depend. Therefore, if the temporal change rate is measured, the degree of change in the output characteristics of the wind speed sensor due to the adhesion state of dust or the like on the resistance heating element or the adhesion of dust to the resistance heating element is normal regardless of the presence or absence of exhaust clogging. By doing so, it can be seen that the actual air volume of the blower fan can be properly grasped at the output level of the wind speed sensor regardless of the presence or absence of exhaust clogging.

The present invention has been made to achieve the above object based on this finding, and the first embodiment includes a resistance heating element disposed in a flow path of gas blown by a blowing fan as a detection element, and the air flow rate or wind speed of the blower gas. Combustion comprising a wind speed sensor for outputting an electrical signal of the level according to the control unit, and fan control means for controlling the rotational speed of the blower fan so that the air volume or wind speed detected by the output level of the wind speed sensor is a target air volume or target wind speed An apparatus for controlling a blower of an apparatus, comprising: measuring means for measuring a temporal change rate of an output level of the wind speed sensor when the rotation speed of the blowing fan is increased by the fan control means, and the time measured by the measuring means When the rate of change is less than the reference value determined as the rate of change of time at the time of normality of the wind speed sensor, thereafter Correction means for correcting the air volume or wind speed detected by the output level of the speed sensor according to the temporal rate of change to coincide with the air volume or wind speed detected at the normal time of the wind speed sensor, and the air volume corrected by the correction means or And a fan control means for controlling the rotation speed of the blower fan so as to target a target wind speed or target air volume of the wind speed.

And operation stop means for stopping the operation of the following blower when the temporal change rate measured by the measuring means is less than a predetermined amount by the reference value.

In addition, it is characterized by comprising an alarm means for generating an alarm when the temporal change rate measured by the measuring means is less than or equal to the reference value by a predetermined value.

The blower fan is a blower fan that blows combustion air into a burner, and the measuring means measures the temporal change rate at the start of prepurge of a combustion device including the blower fan and the burner.

In addition, the second embodiment of the present invention is provided with a resistance heating element disposed in the flow path of the gas blown by the blowing fan in order to achieve the above object, an electric signal of the level according to the air flow rate or wind speed of the blower gas In the blow control device of the combustion apparatus comprising a wind speed sensor for outputting and a fan control means for controlling the rotational speed of the blowing fan so that the air flow rate or the wind speed detected by the output level of the wind speed sensor is a target wind speed or target wind volume Measuring means for measuring the temporal rate of change of the output level of the wind speed sensor according to this when the blower fan stops by lowering the rotational speed at the end of the blowing operation, and the rate of temporal rate of change measured by the measuring means is The output level of the wind speed sensor during the next blowing operation when the sensor is larger than the reference value determined as the temporal change rate at the time of normal operation of the sensor. Correction means for correcting the amount of wind or wind speed detected by the controller according to the temporal rate of change so as to match the amount of wind or wind speed detected at the time of normality of the wind speed sensor. The rotation speed of the blowing fan is controlled by the fan control means to achieve a target wind speed.

And when the temporal rate of change measured by the measuring means is larger than the reference value by a predetermined amount, an operation prohibition means for prohibiting the operation of a subsequent blower fan is provided.

In addition, it is characterized by including an alarm means for generating an alarm when the temporal change rate measured by the measuring means is larger than the reference value by a predetermined amount.

The blower fan is a blower fan that blows combustion air to a burner, and the measuring means measures the temporal change rate at the end of post purge of a combustion device including the blower fan and the burner.

According to the first embodiment of the present invention, in the initial stage of the blowing operation, when the fan control means raises the rotation speed of the blowing fan in its stopped state, the output means of the wind speed sensor is measured by the measuring means. The temporal rate of change is measured. The temporal change rate measured in this way is smaller than the reference value in the initial normal case where dust or the like is adhered to the resistance heating element of the wind speed sensor. The extent to which the temporal rate of change obtained by the measuring means becomes smaller than the reference value depends on a state in which dust or the like adheres to the resistance heating element without being affected by the clogging of the air supply side or the exhaust side of the blower fan. Therefore, when dust or the like is attached to the resistance heating element of the wind speed sensor and the output characteristic of the fraudulent wind speed sensor is changed from the normal case, the rate of temporal change measured by the wind volume or wind speed detected by the output level of the wind speed sensor is measured. By correcting by the correction means according to the above, an appropriate amount of detected wind or detected wind speed corresponding to the actual amount of air or wind speed is obtained without being influenced by exhaust clogging or the like. Then, by controlling the rotation speed of the blower fan so that the detected wind speed or the detected wind speed is matched with the target wind speed or the target wind speed, the output characteristics of the wind speed sensor can be improved by adhesion of dust or the like to the resistance heating element of the wind speed sensor. Even if it changes compared with the normal case, it becomes possible to control the actual air volume to be the target air volume or the target wind speed, thereby making the blowing operation appropriate.

In this case, when dust or the like is excessively adhered to the resistance heating element of the wind speed sensor, there is a possibility that proper control of the blower fan cannot be performed even by correction by the correction means. When the predetermined amount is smaller than this, it is preferable to stop the operation of the subsequent blow control device of the combustion apparatus by the stop means or to generate an alarm by the alarm means. By doing in this way, it becomes possible to prompt the user or the like to replace or clean the wind speed sensor and to eliminate the possibility of improper control of the blowing fan.

In the case of a blower fan that blows combustion air to the burner of the blower fan, since the blower fan is increased from the standstill state to a predetermined number of revolutions at the start of the combustion operation, prepurging of the combustion device is performed. It is preferable to measure the temporal change rate at the time of the piper purge. In this way, it is possible to measure the temporal rate of change without having to perform a special operation of the blower fan only to measure the temporal rate of change, and at the time of actual combustion of the burner after the prepurge, By controlling the rotation speed of the blowing fan using the detection wind speed, it is possible to perform combustion of the burner under appropriate conditions.

Next, according to the second embodiment of the present invention, the temporal change rate of the output level of the wind speed sensor is measured by the measuring means when the blowing fan stops by decreasing its rotation speed at the end of the blowing operation. The temporal change rate measured in this way is larger than the reference value in the original normal case in which dust or the like is adhered to the resistance heating element of the wind speed sensor. The extent to which the temporal rate of change obtained by the measuring means becomes larger than the reference value is not affected by clogging on the air supply side or the exhaust side of the blower fan and depends on the adhesion state of dust or the like on the resistance heating element. Therefore, when dust or the like is attached to the resistance heating element of the wind speed sensor and the output characteristic of the wind speed sensor is changed as compared with the normal case originally, it is detected by the output level of the wind speed sensor during the next blowing operation. By correcting the air flow rate and the wind speed by the correction means in accordance with the temporal change rate measured at the end of the last blow operation, an appropriate detection wind amount or detection wind speed corresponding to the actual air flow rate or the wind speed is obtained without being affected by exhaust clogging or the like. When the output characteristics of the wind speed sensor are normal as dust or the like is attached to the resistance heating element of the wind speed sensor by controlling the rotation speed of the blower fan so that the detected wind speed or the detected wind speed is the target wind speed or the target wind speed. In comparison with this, it is possible to control the actual air volume so as to be the target air volume or the target wind speed, thereby making the blowing operation appropriate.

Further, in the second embodiment of the present invention, when the operation prohibiting means or the alarm means is provided, the same operation as in the first embodiment is performed. In this case, since the temporal rate of change is measured at the end of the combustion operation, when the temporal rate of change is larger than the reference value by a predetermined amount, the operation prohibition means prohibits the subsequent operation of the blowing fan.

When the blower fan is a blower fan that blows combustion air into the burner, the blower fan is driven at a predetermined rotational speed for a predetermined time after the burner stops combustion, so that post-purging is performed and the blower fan is stopped. It is preferable to measure the temporal change rate at the end of. In this way, it is possible to measure the temporal rate of change without having to perform a special operation of the blower fan only to measure the temporal rate of change, and to perform the above correction during the combustion operation of the next burner after the post purge. By controlling the rotation speed of the blower fan by using the detected wind amount or the detected wind speed, it is possible to appropriately burn the burner.

An example of the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a system configuration diagram of a hot water heater equipped with a blow control device according to the present embodiment, FIG. 2 is a block diagram showing the main parts of the hot water heater shown in FIG. 1, and FIG. 5 is a diagram for explaining the operation of the water heater shown in FIG. to be.

In FIG. 1, 1 is a water heater main body which incorporates the heat exchanger 2 and the burner 3 which heats it, 4 is the water flow pipe piped through the heat exchanger 2, 5 flows through the water flow pipe 4 Flow rate sensor for detecting the flow rate of water on the upstream side of the heat exchanger (2), 6 is a temperature sensor for detecting the tapping temperature of the water flowing through the water pipe (4) on the downstream side of the heat exchanger (2), 7 is the burner (3) Gas supply pipes for supplying gas to the gas, 8, 9 is an on-off solenoid valve and a gas proportional valve sequentially installed upstream in the gas supply pipe (7), 10 is a blowing fan for blowing combustion air to the burner (3), 11 is Fan motor for driving the blowing fan 10, 12 is a rotation speed sensor composed of a hall element for detecting the rotation speed of the blowing fan 10, 13 is a blow passage 14 from the blowing fan 10 to the burner Wind speed sensor disposed in the, 15 is the operation unit for the user to set the tapping temperature, etc., 16 is the installation of the hot water set by the operation unit 15 A controller for controlling the fan motor 11, the solenoid valve 8, the gas proportional valve 9, etc. in accordance with the temperature and the detection signals of the sensors 5, 6, 12, 13, and the like. An igniter for ignition 18 is a flame rod that detects a combustion state such as the presence or absence of misfire of the burner 3.

In addition, 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) such as a kitchen or a bathroom.

In addition, the wind speed sensor 13 is the heat-type wind speed sensor shown in the tenth, wherein the resistance heating element (c) and the temperature compensation resistor (d) made of platinum wires of the bridge circuit (e) are arranged in the air passage (14). have. The wind speed sensor 13 outputs a signal having a level corresponding to the amount of air flow from the blowing fan 10 to the burner 3 from the amplifier i to the controller 16. In this case, the output level of the wind speed sensor 13 increases as the air volume increases.

In FIG. 2, the controller 16 is constituted by an electronic circuit including a microcomputer and the like, and as a functional configuration thereof, is detected by a set temperature given by the operation unit 15 and a water temperature sensor (not shown). Combustion amount required to obtain the required combustion amount of the burner 3 necessary to match the tapping temperature to the set temperature from the obtained inlet temperature, the tapping temperature detected by the temperature sensor 6, the flow rate detected by the flow sensor 5, and the like An operation unit 19; An air volume setting unit 20 for setting a target air volume (supply amount of combustion air) from the blowing fan 10 to the burner 3 corresponding to the required combustion amount calculated by the calculating unit 19; A wind volume inspection unit 21 for grasping the air volume of the blowing fan 10 according to the output level of the wind speed sensor 13; A change rate measuring section (measurement means) 22 for measuring a temporal change rate of the output level of the wind speed sensor 13 when the blowing fan 10 is started at the start of the hot water supply operation; A storage unit 23 for storing and storing the temporal change rate measured by the change rate measuring unit 22; A correction unit (correction means; 24) for correcting the detected air volume obtained by the air volume detection unit 21 in accordance with the temporal change rate stored and stored in the storage unit 23; A fan control unit 25 for controlling the rotation speed of the blower fan 10 through the fan motor 11 according to the detected wind amount corrected by the correction unit 24, the target wind amount set by the air flow rate setting unit 20, and the like; A valve control unit 26 for controlling a gas supply amount to the burner 3 by controlling the opening degree of the gas proportional valve 9 according to the rotation speed of the blowing fan 10 detected by the rotation speed sensor 12; An alarm command unit 28 for driving the alarm unit 27 according to the temporal change rate measured by the change rate measuring unit 22; A stop for stopping the blowing fan 10 through the fan control unit 25 and shutting off the gas supply to the burner 3 through the solenoid valve 8 in accordance with the temporal change rate measured by the change rate measuring unit 22. The command part 29 is provided. The alarm 27 is constituted by an alarm lamp, a buzzer or the like provided in the hot water supply main body 1 or the operation unit 15.

Here, in response to the configuration of the present invention, the fan control unit 25 constitutes the fan control means 30 together with the fan motor 11 and the rotation speed sensor 12, and the alarm command unit 28 and the alarm unit 27. ) Constitutes an alarm means 31, and the alarm command unit 29 constitutes a stop means 32 together with the fan control unit 25 and the solenoid valve 8.

In addition, when water supply is started to the water supply pipe 4, the controller 16 detects this through the flow sensor 5, and the fan control unit 25 blows the fan 10 through the fan motor 11 according to the detection. ), The solenoid valve 8 of the gas supply pipe 7 is opened and the gas supply to the burner 3 is started, and the hot water supply operation is performed by igniting the burner 3 through the igniter 17. It starts. At this time, as shown in FIG. 3 before the ignition of the burner 3, the fan control unit 25 starts the blowing fan 10, and then sets the rotation speed of the blowing fan 10 to a predetermined rotational speed (NO). Pre-purge is carried out by raising at a predetermined temporal rate of change and holding at a predetermined rotation speed NO for a predetermined time. Subsequent to this prepurge, the ignition of the burner 3 is performed gently with the blowing fan 10 rotating the blowing fan 10 at a speed substantially equal to the predetermined rotation speed NO.

When the water flow pipe 4 detects that water flow is stopped through the flow sensor 5, the controller 16 closes the electronic safety valve 8 to shut off the gas supply to the burner 3, The fan control unit 25 stops the blower fan 10 to finish the hot water supply operation. At this time, the fan control unit 25 causes the electronic safety valve 8 to be in a closed state, and then rotates the blower fan 10 at a predetermined rotation speed NO for a predetermined time to perform post purge. When finished, the power supply to the fan motor 11 is stopped to stop the blower fan 10. The end operation of the hot water supply operation is similarly performed even when a misfire or the like of the burner 3 is detected by the flame rod 18 during the hot water operation.

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

At the start of the hot water supply operation, as described above, prior to the ignition of the burner 3, the fan control unit 25 of the controller 16 causes the blower fan 10 to operate at a predetermined rotational speed NO through the fan motor 11. And the preliminary purge, and then the controller 16 starts the gas supply to the burner 3 with the electronic safety valve 8 open, and burner 3 via the igniter 17. Is gently ignited and combustion of the burner 3 is started.

In the pre-purge, while the change rate measuring unit 22 of the controller 16 is until the rotation speed of the blowing fan 10 rises from the stop state to the predetermined rotation speed NO as shown in FIG. The temporal change rate of the output level of the wind speed sensor 13 is measured and stored in the storage unit 23. At this time, the output level of the wind speed sensor 13 rises as shown in FIG. 4 as the rotation speed of the blowing fan 10 rises, and the temporal increase degree is measured by the change measuring section 22. Such measurement is performed using, for example, a fine powder. In addition, the temporal change rate stored in the storage section 23 suitably measures the amount of detected wind volume obtained by the air volume detector 21 at the output level of the wind speed sensor 13 as described later in the subsequent combustion operation of the burner 3. Used to calibrate.

Subsequently, as described above, when the burner 3 is ignited after combustion and combustion starts, the controller 16 calculates the required combustion amount by the calculation unit 19 and the tapping temperature detected by the temperature sensor 6. The required combustion amount of the burner (3) necessary to match the set temperature set by) is determined at every time based on detection data such as inlet temperature, tapping temperature or flow rate. In addition, the air volume setting unit 20 of the controller 16 sets the target air volume from the blowing fan 10 to the burner 3 corresponding to the required combustion amount calculated by the required combustion amount calculating unit 19 according to a predetermined table or the like. .

Subsequently, the controller 16 rotates the blower fan 10 by the fan control unit 25 so that the actual amount of air blown from the blower fan 10 to the burner 3 matches the target airflow obtained corresponding to the required combustion amount as described above. The number is controlled through the fan motor 11.

In this case, the fan control unit 25 basically detects the detected air volume detected by the air volume detector 21 at the output level of the wind speed sensor 13 (this is a state in which the wind speed sensor 13 is normal (no dust or the like is attached). ), The rotational speed of the blower fan 10 is controlled to match the actual air flow rate. Such control is specifically performed as follows, for example. That is, the fan control unit 12 basically determines the reference rotational speed as a reference according to a predetermined data table or the like corresponding to the target air volume given by the air volume setting unit 20, and is detected by the rotation sensor 12. The rotation speed of the blowing fan 10 is feedback-controlled through the fan motor 11 so that the actual rotation speed of the blowing fan 10 corresponds to the reference indicated rotation speed. At this time, the detected air volume obtained through the wind speed sensor 13 and the target air volume given by the air volume setting unit 20 are compared with the indicated rotational speed of the blowing fan 10 with respect to the reference indicated rotational speed so that these deviations are eliminated. By correcting and doing this, the blowing fan 10 is controlled so that a detection wind volume and a target wind volume may correspond. By performing such a control, even if the exhaust blockage or the air supply blockage occurs somewhat, it is possible to blow an appropriate amount of air from the blower fan 10 to the burner 3.

When the rotation speed of the blower fan 10 is controlled as described above, when no dust or the like is attached to the resistance heating element c of the wind speed sensor 13 and the wind speed sensor 13 is normal, a wind speed sensor Although the detected air volume determined by the output level of (13) is used to control the rotation speed of the blower fan 10 as it is, dust or the like is attached to the resistance heating element c of the wind speed sensor 13 so that the wind speed sensor When the output characteristic of (13) is changed as compared with the normal case, the detected air volume corrected by the correcting section 24 is used for controlling the rotation speed of the blower fan 10. Details of this will be described later. Here, the case where the wind speed sensor 13 is normal will be described.

On the other hand, in the combustion operation of the burner 3, the valve control unit 26 of the controller 16 performs the burner (through the gas proportional valve 9) in parallel with the control of the blowing fan 10 as described above. 3) The gas supply amount to the furnace is controlled (fan leading type). In this case, basically, the valve control unit 26 controls the opening degree of the gas proportional valve 9 according to the actual rotation speed of the blowing fan 10 detected by the rotation speed sensor 12. Therefore, when there is no clogging of the exhaust gas and the load of the blower fan 10 is normal, the rotational speed of the blower fan 10 and the actual amount of blows correspond to each other, so that the gas depends on the number of revolutions of the blower fan 10 as described above. By controlling the opening degree of the proportional valve 9, the gas supply amount to the burner 3 corresponds to the air volume to the burner 3 controlled by the target air volume, and the burner 3 burns by the required combustion amount.

However, since the rotation speed of the blower fan 10 is controlled to match the detected air flow rate with the target air flow as described above, in the case where exhaust clogging or the like has occurred, even if the air flow rate to the burner 3 is the same, The rotation speed is increased or decreased depending on the degree of clogging of the exhaust gas. Therefore, simply controlling the opening degree of the gas proportional valve 9 in accordance with the rotational speed of the blower fan 10, even if the air volume to the burner 3 is the same, the gas proportional valve according to the rotational speed of the blower fan 10 The opening degree of (9) changes and the gas supply amount to the burner 3 changes.

Therefore, the valve control unit 26 of the controller 16 is configured to cancel the blow fan 10 when the detected wind volume by the wind speed sensor 13 is less than the target wind volume in order to offset the correction amount of the rotation speed of the blow fan 10. Since the rotation speed is increased as compared with the normal case without exhaust clogging, the opening degree of the gas proportional valve 9 is reduced from the opening degree according to the rotation speed of the blowing fan 10, and in the opposite case, the gas proportional valve 9 ) Is increased from the opening degree according to the rotation speed of the blowing fan 10. In this way, the gas supply amount to the burner 3 corresponds to the required combustion amount, and burns smoothly by the required combustion amount.

However, when dust or the like adheres to the resistance heating element c of the wind speed sensor 13 when controlling the rotation speed of the blowing fan 10 as described above, the wind speed of the wind speed sensor 13 as described above ( Since the output characteristic with respect to the air volume) changes compared with the output characteristic in the original case (see FIG. 11), the detected air volume determined by the output level of the wind speed sensor 13 becomes smaller than the actual air volume. Therefore, when dust or the like is attached to the resistance heating element c of the wind speed sensor 13, and if the detected wind volume itself determined by the output level of the wind speed sensor 13 as described above is controlled to match the target wind volume. Therefore, the actual air volume is controlled to be larger than the target air volume.

In order to avoid such a situation, the correction unit 24 of the controller 16 changes the temporal rate of change of the output level of the wind speed sensor 13 stored and stored in the storage unit 23 at the start of the hot water supply operation as described above. In accordance with this, the air volume detector 21 sequentially corrects the detected air volume obtained at the output level of the wind speed sensor 13.

More specifically, the correction unit 24 first determines the detected air flow amount according to a predetermined data table as shown in FIG. 5 at the temporal change rate stored in the storage unit 23 at the start of the hot water supply operation. A correction coefficient K for correction is obtained, and the detection wind amount is corrected by multiplying the correction coefficient K by the detection air volume obtained at the output level of the wind speed sensor 13.

Here, the correction coefficient K is obtained when the rotation speed of the blower fan 10 is raised as described above in the normal state of the wind speed sensor 13 (when no dust or the like is attached to the resistance heating element c). On the basis of the temporal change rate of the output level of the wind speed sensor 13, when the temporal change rate measured at the start of this hot water supply operation coincides with the temporal change rate of the reference, K = 1, and the measured temporal change rate is The correction coefficient K is determined to be larger than 1 as it becomes smaller than the temporal rate of change of the reference. In addition, the temporal change rate of the said air is predetermined based on an experiment etc., for example.

In this case, the temporal rate of change becomes smaller as the output level of the wind speed sensor 13 decreases (see FIG. 11) as adhesion of dust or the like proceeds to the resistance heating element c of the wind speed sensor 13, By the rate of change, the correction coefficient K determined in accordance with the data table is increased. Therefore, when the dust or the like is attached to the resistance heating element c of the wind speed sensor 13 by correcting the detected wind volume by multiplying the correction coefficient K by the detection air volume obtained at the output level of the wind speed sensor 13, the wind speed sensor ( The detected wind volume (which is smaller than the detected wind volume when the wind speed sensor 13 is normal) is corrected to match the detected wind volume obtained when the wind speed sensor 13 is normal. In this case, since the temporal change rate for correcting the detected wind volume depends only on a state where dust or the like is attached to the resistance heating element c of the wind speed sensor 13 and is not affected by the exhaust clogging. By performing the correction as described above, the amount of change in the output characteristic of the wind speed sensor 13 due to the attachment of dust or the like is corrected, and the detected air volume obtained by this correction correctly indicates the actual air volume.

The fan control unit 25 and the valve control unit 26 perform the control of the blower fan 10 and the control of the gas proportional valve 9 as described above by using the detection air volume corrected by the correction unit 24. . Therefore, regardless of the adhesion state of dust or the like on the resistance heating element c or the load state of the blower fan 10, the rotation speed of the blower fan 10 can be appropriately controlled to match the actual air flow rate with the target air flow amount. have. Further, the gas proportional valve 9 is controlled so that the burner 3 is supplied with an amount of gas corresponding to the air volume controlled by the target weight, and the burner 3 reliably burns smoothly by the required combustion amount.

In the hot water heater of the present embodiment, the alarm command unit 28 and the stop command unit 29 of the controller 16 monitor the temporal rate of change measured at the start of the hot water operation, and compared with the case where the temporal rate of change is normal. When it becomes smaller than predetermined | prescribed small value R (refer FIG. 5), the alarm command part 28 says an alarm by the alarm 27. As shown in FIG. At this time, the stop command unit 29 stops the operation of the blower fan 10 through the fan control unit 25, and stops the hot water supply operation with the solenoid valve 9 closed. By doing so, when the dust or the like is excessively attached to the resistance heating element c of the wind speed sensor 13, and proper control of the blower fan 10 and the like becomes difficult even by the above-described control, the wind speed sensor 13 In addition to making the user aware of the replacement or cleaning, it is possible to eliminate the situation where inappropriate control is performed in such a situation.

In the present embodiment, the predetermined value R of the temporal rate of change for determining the timing at which the alarm is generated or the stop of the hot water operation is made the same, but for example, the alarm according to the temporal rate of change is faster than the stop of the hot water operation. You may do it at.

In the present embodiment, although the temporal change rate of the reference is set in advance, for example, since the wind speed sensor 13 is considered to be normal during the first hot water supply operation, the temporal change rate measured at the start of the first hot water supply operation is considered. May be set as a reference temporal change rate. In this case, the detection air volume is appropriately corrected from the second hot water supply operation.

In addition, in this embodiment, although the wind speed sensor 13 whose output level increases with the increase of the air volume has been described as the wind speed sensor, the wind speed is configured such that the output level decreases with the increase of the wind speed by using an inverting amplifier. Of course, a sensor may be used.

In addition, in this embodiment, although the air volume control is performed, the wind speed control may be performed because the air volume and the wind speed are in proportion to each other.

In the present embodiment, the blow control device provided in a combustion device such as a hot water heater has been described as an example, but the first embodiment of the present invention can also be applied to a blow control device provided in another combustion device such as a fan heater. Of course.

Next, an example of the second embodiment of the present invention will be described with reference to Figs. 6 to 9, Fig. 6 is a block diagram showing the main part of the water heater of this embodiment, and Fig. 9 is a diagram for explaining the operation of the water heater of this embodiment. . In addition, the blow control apparatus of this embodiment is provided with the water heater of FIG. 1, and the system structure of this water heater is the same as that of FIG. In the following description, the same components as those of the hot water heater of FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the hot water heater equipped with the blow control device of the present embodiment, the controller 16 shown in FIG. 1 has the necessary combustion amount calculating unit 19, the air volume setting unit 20, and the air volume detecting unit 21 as in the first embodiment. And a change rate measuring unit 22, a storage unit 23, a correction unit 24, a fan control unit 25, a valve control unit 26 and an alarm command unit 28, and the stop shown in FIG. Instead of the command unit 29, the operation prohibition command unit 33 is provided. Here, in response to the configuration of the second embodiment of the present invention, the fan control unit 25 constitutes the fan control means 30 together with the fan motor 11 and the rotation speed sensor 12, and the operation prohibition command unit 33 ), Together with the fan control unit 25 and the solenoid valve 8 constitutes an operation prohibition means 34.

In the hot water heater of the present embodiment, the operation of the configuration other than the change rate measuring unit 22, the correction unit 24, the alarm command unit 28 and the operation prohibition command unit 33 is different from that of the first embodiment. same.

Therefore, the operation of the hot water heater of this embodiment different from the hot water heater of the first embodiment described above will be described next.

In the hot water heater of this embodiment, at the end of the hot water operation, the fan control unit 25 rotates the blower fan 10 at a predetermined rotation speed NO for a predetermined time as shown in FIG. After the operation, the energization of the fan motor 11 is stopped to stop the blower fan 10.

At this time, the change measuring unit 22 of the controller 16 when the rotation speed of the blower fan 10 drops from the predetermined rotation speed NO measures the temporal change rate of the output level of the wind speed sensor 13. The memory 23 keeps the memory.

Subsequently, when the combustion operation of the burner 3 is started during the next hot water supply operation, the correction unit 24 of the controller 16 detects the output level of the wind speed sensor 13 by the air flow rate detection unit 21. The air volume is corrected according to the temporal change rate stored and stored in the storage unit 23 at the end of the last hot water supply operation. In this case, the correction is performed by determining the correction coefficient K in accordance with the temporal change rate stored in the storage unit 23 and multiplying the correction coefficient K by the detected air volume as in the first embodiment. The correction coefficient K is determined according to a data table as shown in FIG. 9, for example.

More specifically, the temporal rate of change of the output level of the wind speed sensor 13 measured at the time of stopping the blower fan 10 is, as described above, attached to dust or the like in the resistance heating element c of the wind speed sensor 13. As this progresses, it becomes larger than the original normal case. The temporal rate of change is not affected by exhaust clogging.

Therefore, in the present embodiment, when the wind speed sensor 13 is normal (when dust or the like is not adhered to the resistance heating element c), the rotation speed of the blower fan 10 is lowered and stopped as described above. Based on the temporal rate of change of the output level of the wind speed sensor 13 obtained at the time, and when the temporal rate of change measured at the end of the last hot water supply operation coincides with the temporal rate of change of the reference, K = 1, and the measured temporal rate of change It is determined that the value of the correction coefficient K becomes larger than 1 as it becomes larger than the temporal change rate of the said reference | standard. In addition, the temporal change rate of the said reference | standard is predetermined previously based on an experiment etc., for example.

The correction unit 24 determines the correction coefficient K according to the temporal change rate measured at the end of the hot water supply operation of the telephone based on such a data table, and sets the correction coefficient K at the time of the hot water supply operation. The amount of detected air is corrected by multiplying by the amount of air detected at the time of burning the burner 3. By performing such correction, the amount of detected wind detected by the output level of the wind speed sensor 13 when dust or the like adheres to the resistance heating element c of the wind speed sensor 13 (this is the wind speed sensor). (13) is smaller than the detected wind volume when it is normal) is corrected to match the detected wind volume obtained when the wind speed sensor 13 is normal. In this case, since the temporal change rate for correcting the detected air volume depends only on the adhesion state of dust or the like in the resistance heating element c of the wind speed sensor 13 as described above, and is not affected by the exhaust clogging or the like. By performing the correction as described above, only the change in the output characteristic of the wind speed sensor 13 due to the attachment of dust or the like is corrected, and the detected air volume obtained by the correction correctly indicates the actual air volume.

The air volume control and the gas volume control by the fan control unit 25 and the valve control unit 2 are performed in the same manner as in the above-described first embodiment by using the detected air volume corrected as described above, whereby the resistance heating element c The number of revolutions of the blower fan 10 can be appropriately controlled so that the actual air flow rate and the target air flow coincide with each other regardless of the adhesion state of dust or the like. In addition, the gas proportional valve 9 is controlled so that the burner 3 is supplied with an amount of gas corresponding to the air volume controlled by the target air volume, and the burner 3 is smoothly burned by the required combustion amount.

In the first hot water supply operation, the correction unit 24 sets the value of the correction coefficient K to 1 so that the detected air volume determined by the output level of the wind speed sensor 13 is used for air volume control or the like as it is. In this case, the wind speed sensor 13 may be generally considered to be normal in the first hot water supply operation, so that the amount of detected air volume may not be corrected.

In addition, the alarm command unit 28 and the operation prohibition command unit 33 of the controller 16 monitor the temporal rate of change measured at the time of stopping the blower fan 10, and the predetermined rate is relatively large compared to the case where the temporal rate of change is normal. When the value R (see Fig. 9) is exceeded, the alarm command unit 28 generates an alarm by the alarm 27. At this time, the operation prohibition command unit 33 prohibits the subsequent operation of the blower fan 10 through the fan control unit 25, and maintains the solenoid valve 8 in a closed state so that subsequent hot water supply operation is performed. Forbid. By doing so, when dust or the like is excessively attached to the resistance heating element c of the wind speed sensor 13, and proper control of the blower fan 10 and the like becomes difficult even by the above-described control, the wind speed sensor 13 In addition to making the user aware of the replacement or cleaning, it is possible to eliminate the situation where inappropriate control is performed in such a situation.

It should be understood that the second embodiment of the present invention is not limited to the above embodiment, but various modifications described in the above-described first embodiment are possible.

As is clear from the above description, according to the first embodiment of the present invention, when the rotation speed of the blower fan is controlled so that the wind speed or air volume detected by the wind speed sensor is the target wind speed or the target wind volume, the rotation speed of the blowing operation is increased. In addition, at this time, the temporal change rate of the output level of the wind speed sensor is measured, and then the wind speed or air volume detected by the output level of the wind speed sensor is corrected according to the measured temporal change rate, and the corrected detection wind speed is Alternatively, by controlling the blower fan so that the detected wind volume is the target wind speed or the target wind volume, even if dust or the like is attached to the resistance heating element of the wind speed sensor and the output characteristic of the wind speed sensor changes, the blower fan is not affected by the load fluctuation of the blower fan. Air volume or wind speed control can be appropriately performed.

When the measured temporal rate of change is less than a predetermined amount determined by the temporal rate of change of the wind speed sensor at a predetermined amount or more, an alarm or an operation of the blower is stopped so that dust or the like is excessively attached to the resistance heating element of the wind speed sensor. When there is a possibility that proper control of the blower fan cannot be performed, it is possible to promptly prompt the user or the like to replace or clean the wind speed sensor, and to eliminate the possibility of improper control of the blower fan.

In the case where the blowing control device is provided with the combustion device, the timing of the rate of change is measured at the time of prepurge, so that proper timing of the blower fan is not performed during a series of operations required for the combustion operation of the combustion device. The temporal change rate can be measured efficiently.

Further, according to the second embodiment of the present invention, in the case where the fan speed is controlled so that the wind speed or the air volume detected by the wind speed sensor is the target wind speed or the target wind volume, the fan is rotated at the end of the blowing operation. While measuring the temporal change rate of the output level of the wind speed sensor at the time of stopping and lowering the speed, the detected wind speed or the detected wind speed determined by the output level of the wind speed sensor is determined according to the temporal change rate measured during the next blowing operation. Alternatively, by controlling the blower fan to achieve the target wind speed, even if dust or the like is attached to the resistance heating element of the wind speed sensor, the air flow rate or wind speed control of the blower fan can be controlled without being affected by load fluctuation of the blower fan even if the output characteristics of the wind speed sensor change. It can carry out suitably.

When the measured temporal change rate becomes larger than a predetermined value determined as the normal temporal change rate of the wind speed sensor, an alarm is issued or the operation of the blower is stopped so that dust or the like is excessively attached to the resistance heating element of the wind speed sensor. When there is a possibility that proper control of the blower fan cannot be performed, it is possible to promptly prompt the user or the like to replace or clean the wind speed sensor, and to eliminate the possibility of improper control of the blower fan.

In the case where the blowing control device is provided with the combustion mechanism, the timing of the rate of change is measured at the end of the post purge, so that the proper timing is not performed during the series of drawings required for the combustion operation of the combustion device. The temporal change rate can be measured efficiently.

Claims (8)

A resistance heating element disposed in the flow path of the gas blown by the blower fan as a detection element, the wind speed sensor outputting an electric signal having a level corresponding to the air flow rate or the wind speed of the blower gas, and detected by the output level of the wind speed sensor; A blowing control apparatus for a combustion apparatus including a fan control means for controlling the rotation speed of the blowing fan so that the air flow rate or the wind speed becomes the target air flow rate or the target wind speed, wherein the rotation speed of the blowing fan is stopped by the fan control means. When rising, the measuring means for measuring the temporal change rate of the output level of the wind speed sensor according to this, and the temporal change rate measured by the measuring means is less than the predetermined reference value as the temporal change rate at the normal time of the wind speed sensor. After that, the air volume or wind speed detected by the output level of the wind speed sensor is Correction means for correcting according to the temporal rate of change so as to match the emitted air volume or wind speed, and rotation of the blowing fan by the fan control means such that the air volume or wind speed corrected by the correcting means is a target wind speed or a target air volume Blowing apparatus for a combustion apparatus, characterized in that for controlling the number. The blowing control of a combustion apparatus according to claim 1, further comprising an operation stop means for stopping the operation of a subsequent blow fan when the temporal change rate measured by the measuring means is a predetermined amount or more than the reference value. Device. The blowing control device according to claim 1 or 2, further comprising alarm means for generating an alarm when the temporal change rate measured by the measuring means is a predetermined amount or less than the reference value. The blower fan according to claim 1, wherein the blower fan is a blower fan that blows combustion air into a burner, and the measuring means measures the temporal change rate at the start of pre-purging of a combustion device including the blower fan and a burner. Blowing control device of the combustion device characterized in that. A resistance heating element disposed in the flow path of the gas blown by the blower fan as a detection element, the wind speed sensor outputting an electric signal having a level corresponding to the air flow rate or the wind speed of the blower gas, and detected by the output level of the wind speed sensor; A blowing control apparatus for a combustion device having a fan control means for controlling the rotation speed of the blowing fan so that the air flow rate or the wind speed becomes the target wind speed or target wind speed, wherein the blowing fan lowers the rotation speed at the end of the blowing operation. The measurement means for measuring the temporal rate of change of the output level of the wind speed sensor and the temporal rate of change measured by the measuring means according to this when stopping, when the temporal rate of change of the normal speed of the wind speed sensor is larger than a predetermined reference value, The wind speed sensor detects the air volume or wind speed detected by the output level of the wind speed sensor during the next blowing operation. Correction means for correcting according to the temporal rate of change so as to coincide with the amount of wind or wind speed detected at the time of normal operation, and by the fan control means such that the amount of wind or wind speed corrected by the correction means is a target air volume or target wind speed. Blowing device of the combustion apparatus, characterized in that for controlling the number of revolutions of the blowing fan. The blowing control of the combustion apparatus as claimed in claim 5, further comprising an operation prohibition means for prohibiting the operation of a subsequent blow fan when the temporal change rate measured by the measuring means is greater than or equal to the reference value by a predetermined amount. Device. The blowing control device for a combustion apparatus according to claim 5 or 6, further comprising an alarm means for generating an alarm when the temporal rate of change measured by the measuring means is greater than or equal to the reference value by a predetermined amount. The blower fan according to claim 5, wherein the blower fan is a blower fan that blows combustion air to a burner, and the measuring means measures the temporal change rate when terminating the post purge of a combustion device including the blower fan and the burner. Blowing control device of the combustion device characterized in that.