KR20030047681A - Combustion device - Google Patents

Abstract

PURPOSE: A combustion apparatus is provided to prevent an incomplete combustion of a burner, which is generated when power applied to a fan is saturated, by compensating for a target R.P.M of the fan. CONSTITUTION: A combustion apparatus includes a burner(2) accommodated in a combustion chamber(1), a fan(3), a fluid path(4) and a control unit(5) for controlling an operation of the combustion apparatus. An intake port(11) is formed at a lower portion of the combustion chamber(1) so as to suck air and an exhaust port(12) is formed at an upper portion of the combustion chamber(1) in order to discharge combustion gas generated from the burner(2). The fluid path(4) extends from the intake port(11) to the exhaust port(12). A main solenoid valve(211), a proportional governor valve(212), and two directional valves(213,214) are sequentially installed at an upstream of a gas passage(21). The proportional governor valve(212) continuously adjusts flow rate of gas flowing through the gas passage(21).

Description

Combustion device {COMBUSTION DEVICE}

According to the present invention, a burner installed in an air passage, a fan installed in the air passage, supplying combustion air to the burner, rotation speed measuring means for measuring the rotation speed of the fan, and a combustion amount of the burner Target rotational speed setting means for setting a target rotational speed of the fan, and power to the fan so that the rotational speed of the fan measured by the rotational speed measurement means matches the target rotational speed set by the target rotational speed setting means; The target rotational speed in response to a power supply control means for controlling a supply amount, a blockage degree measuring means for measuring the degree of occlusion of the air passage, and a degree of blockage of the air passage measured by the blockage degree measuring means. A combustion apparatus comprising first correction means for correcting a target rotational speed of the fan set by setting means.

According to the combustion device, the target rotation speed of the fan corresponding to the required combustion amount of the burner is set by the target rotation speed setting means. In addition, the power supply amount to the fan is controlled by the power supply control means so that the rotation speed of the fan measured by the rotation speed measurement means coincides with the target rotation speed. Therefore, normally, the rotation speed of a fan is matched with a target rotation speed, and the burner is supplied with the combustion air of the quantity corresponding to the combustion amount, and the burner's complete combustion state is maintained.

However, even if the rotation speed of the fan is controlled to coincide with the target rotation speed, if the aeration passage is blocked due to the mixing of foreign matters, the air flow in the aeration passage is blocked so that the combustion air corresponding to the combustion amount of the burner is not supplied. do.

Therefore, first, the occlusion degree is measured by using the property that the fan power decreases even if the fan speed is kept constant because the load of the fan decreases as the occlusion degree to the aeration increases by the occlusion degree measuring means. Is measured. More specifically, when the rotation speed of the fan is kept constant, the degree of occlusion to the air passage is measured in accordance with the fluctuation of the electric power recognized as being supplied to the fan by the power supply control means. As the measured occlusion degree increases, the target rotational speed is increased and corrected by the first correction means. In addition, the fan rotation speed is controlled by the fan control means so as to coincide with the new target rotation speed which has been increased and corrected. Therefore, the supply amount of combustion air to the burner reduced by the blockage of the aeration passage is compensated, so that the burner is completely burned.

However, even if the degree of obstruction to the air passage is gradually increased and the target rotation speed is gradually increased and corrected accordingly, the amount of power supplied to the fan by the power supply control means is limited. Therefore, the rotation speed of the fan cannot be increased further. It may become saturated before reaching the target rotational speed.

Therefore, the fan power, which is recognized as being supplied to the fan by the power supply control means, is increased in an offset from the actual fan power supply amount, whereby the occlusion degree to the air passage measured by the occlusion degree measuring means may be inaccurate. In this case, despite the lack of combustion air, the target rotational speed is reversely corrected by the first correction means, and there is a fear that incomplete combustion of the burner is promoted.

Accordingly, an object of the present invention is to provide a combustion apparatus capable of suppressing incomplete combustion of a burner as the amount of power supplied to the fan is saturated.

BRIEF DESCRIPTION OF DRAWINGS Fig. 1 is a configuration explanatory diagram of a combustion device of the present embodiment.

2 is an explanatory diagram of a main part of the combustion device of the present embodiment;

3 is an explanatory view of the operation of the combustion device of the present embodiment;

Explanation of symbols on the main parts of the drawings

1-combustion chamber (vent) 2-burner

3-Fan 51-Speed measurement tool

52-Target rotation speed setting means 53-Power feeding control means

54-occlusion degree measuring means 55-first correction means

56 Determination means 571-Second correction means

Third correction means 58-Combustion control means

71-Power Supply Circuit 72-Pulse Circuit

73-switching circuit 74-smoothing circuit

723-OP amplifier (predetermined circuit) 724-Oscillator circuit

The combustion apparatus of the present invention for solving the above-mentioned problems includes determining means for determining whether the power supply amount to the fan is increased by the power supply control means, and the determination means for the fan by the power supply control means. And a second correction means for reducing and correcting the upper limit value of the target rotational speed of the fan corrected by the first correcting means, at least until it is determined that the amount of power supply can be increased. It is characterized by being.

According to the present invention, after the power supply amount to the fan becomes impossible to increase, the upper limit value of the target rotational speed of the fan is reduced and corrected at least until the state becomes possible to increase. Therefore, when the target rotational speed of the fan is increased and corrected, a state capable of increasing and controlling the fan rotational speed toward the target rotational speed is ensured. In other words, since the power supply to the fan cannot be increased (as long as the degree of obstruction is not reduced), the fan speed can not be increased further, but the target speed is continuously increased and corrected. The situation where the rotation speed is increased can be avoided. As described above, according to the present invention, it is possible to suppress the incomplete combustion of the burner as the amount of power supplied to the fan is saturated.

In the present invention, the occlusion degree measuring means is based on the fan power that is recognized as being supplied to the fan by the power supply control means when the fan rotation speed measured by the rotation speed measurement means is constant. It is characterized by measuring the occlusion degree to the aeration.

According to the present invention, since the target rotation speed is corrected so that the power supply amount to the fan is within the controllable range, the fan power recognized as being supplied to the fan by the power supply control means is shifted from the actual fan power. The situation can be avoided. In addition, the blockage degree to the air passage is accurately measured by the blockage degree measuring means. Further, the target rotational speed of the fan corrected according to the degree of occlusion is set so that the combustion air necessary for the complete combustion of the burner can be sufficiently supplied. Then, the burner's complete combustion state can be reliably maintained.

Further, the present invention is corrected by the first correction means until it is determined that the power supply amount to the fan is increased by the power supply control means by the determination means, and then the power supply amount is determined to be impossible to increase. And third correction means for increasing and correcting the upper limit value of the target rotational speed of the fan.

According to the present invention, when the power supply amount to the fan can be increased, the upper limit value of the target rotational speed of the fan is incrementally corrected until it cannot be increased. Therefore, by increasing and correcting the target rotational speed of the fan to the limit that the power supply amount to the fan cannot be increased further, it is possible to ensure a state capable of increasing and controlling the rotational speed of the fan toward the target rotational speed.

The present invention is also characterized by comprising combustion control means for reducing and correcting the upper limit value of the target combustion amount of the burner when the upper limit value of the target rotational speed of the fan is reduced by the second correction means.

In addition, the present invention, when the upper limit value of the target rotational speed of the fan is reduced by the second correction means, the upper limit value of the target combustion amount of the burner is reduced and corrected, and the target rotational speed of the fan by the third correction means And the combustion control means for incrementally correcting the upper limit value of the target combustion amount of the burner when the upper limit value is increased and corrected.

According to the present invention, the target combustion amount of the burner is excessively set in consideration of the rotational speed of the fan, and furthermore, the upper limit of the supply amount of the combustion air, whereby the combustion air is insufficient and combustion of the burner is poor. The situation can be reliably prevented.

Further, in the present invention, the power supply control means intermittently intercepts the DC signal in the power supply circuit in response to the power supply circuit for outputting the DC signal, the pulse circuit for outputting the pulse signal, and the pulse signal output from the pulse circuit. And a smoothing circuit for smoothing the output from the switching circuit to a signal of a predetermined level and then applying the smoothing circuit to the fan, wherein the determining means is configured to generate a pulse signal from the pulse circuit to the switching circuit. When it is determined whether the output is possible and the pulse signal is determined to be impossible to output, it is determined that the power supply amount to the fan cannot be increased.

According to the present invention, the amount of power supplied to the fan can be controlled according to the ON / OFF time ratio of the switching circuit. When the switching circuit is normally turned on, the power supply to the fan becomes impossible based on the fact that the amount of power supplied to the fan becomes uncontrollable. It is possible to determine whether or not the supply amount is increased.

In the present invention, the pulse circuit includes an oscillation circuit for oscillating a waveform signal of a constant peak level, and a predetermined circuit for outputting a signal having a level corresponding to a target rotation speed set by the target rotation speed setting means. And applying the pulse signal to the switching circuit in response to a difference in magnitude between the peak level of the waveform signal oscillated in the oscillation circuit and the level of the DC control signal output from the predetermined circuit. It is determined whether or not the peak level of the waveform signal output from the oscillation circuit is equal to or less than the level of the signal output from the predetermined circuit. If it is determined that the peak level is less than or equal to the level, the pulse signal from the pulse circuit to the switching circuit cannot be output. It is characterized by determining that.

According to the present invention, on the basis of the fact that the pulse signal is output from the pulse circuit if the signal level from the predetermined circuit is less than the peak level of the waveform signal, but if the signal level is higher than the peak level, the pulse signal is not output and the direct current signal is output. It is possible to determine whether or not the pulse signal for turning ON / OFF is output from the pulse circuit, and further increasing the amount of power supplied to the fan.

In the present invention, the power supply control means includes a power supply circuit for outputting a DC signal, a switching circuit for intermittently outputting a DC signal in the power supply circuit in response to a pulse signal from the outside, and And a smoothing circuit to give the fan after smoothing the output to a signal of a predetermined level, wherein the determining means includes: an output level of a DC signal applied from the power supply circuit to the switching circuit; It is determined whether or not it is greater than a predetermined level by comparison with the output level imparted to the fan via, and when it is determined that it is large, it is determined that the supply current to the fan cannot be increased.

Further, in the present invention, the judging means further determines that the output level of the DC signal applied from the power supply circuit to the switching circuit is higher than the output level given to the fan from the switching circuit through the smoothing circuit. It is judged whether or not exceedingly large, and, when determined to be large, determining that the supply current to the fan cannot increase.

According to the present invention, although the output level in the power supply circuit is initially set higher than the output level to the fan, the power supply capability by the power supply circuit approaches the limit as the difference between the two output levels decreases. It is possible to determine whether or not to increase the amount of power supply. Here, the " predetermined level " means that when switching by the switching circuit is not performed, the output signal is continuously supplied to the fan not intermittently from the power supply circuit, but the level of the output signal that is generated by going through the smoothing circuit in the middle is reduced. Means minutes. The fact that switching by the switching circuit is not performed means that the power supply amount from the power supply circuit to the fan reaches the upper limit and cannot be increased. Therefore, when the difference between the two output levels decreases and becomes below the predetermined level, it can be determined that the amount of power supplied to the fan cannot be increased.

Embodiment of the Invention

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of the combustion apparatus of this invention is described using drawing. 1 is an explanatory diagram of the combustion apparatus of the present embodiment, FIG. 2 is an explanatory diagram of the main components of the combustion apparatus of the present embodiment, and FIG. 3 is an operation explanatory diagram of the combustion apparatus of the present embodiment.

The combustion apparatus shown in FIG. 1 is a hot water supply apparatus, and is based on the setting of the hot water supply temperature by the burner 2 accommodated in the combustion chamber 1, the fan 3, the water passage 4, the remote control 6, and the like. The control unit 5 which controls a hot water supply operation is provided.

In the combustion chamber 1, an intake port 11 through which the combustion air to the burner 2 is sucked is formed in the lower portion thereof, and an exhaust port 12 through which the exhaust gas from the burner 2 is discharged is formed. The air path from the intake port 11 to the exhaust port 12 of the combustion chamber 1 constitutes the "air passage" of the present invention.

The burner 2 is ignited by the igniter 23 through the ignition electrode 22 to the gas supplied through the gas passage 21, and burns, and the state of the combustion flame is detected by the flame rod 24.

The gas passage 21 is provided with a main solenoid valve 211, a governor proportional solenoid valve 212 and two capability switching solenoid valves (hereinafter referred to as "switching valves") 213 and 214 sequentially from upstream to downstream. The governor proportional solenoid valve 212 is energized and controlled by the control unit 5, and is continuously opened by opening to correspond to the amount of energization, thereby continuously adjusting the amount of gas flowing through the gas passage 21. The switching valves 213 and 214 are energized and controlled by the control unit 5, and a combination of opening and closing of the valves (the switching valves 213 and 214 are all open, only the switching valve 213 is opened and the switching valve 214 is opened). The gas supply amount to the burner 2 is switched by. By combining the governor proportional solenoid valve 212 and the switching valves 213 and 214, the width of combustion control is large and fine control is possible.

The channel 4 is a water supply passage 41 connected to a water supply not shown upstream from the upstream, a heat exchange passage 42 continuous from the upstream to the water supply passage 41, and a downstream heat exchange passage 42 upstream. It consists of a hot water supply passage 43 connected to a faucet not shown in the figure, and a bypass passage 44 branched from the water supply passage 41 and joined to the hot water supply passage 43. Electric flow quantity control device which is energized and controlled by the control unit 6 at the branching positions of the water supply passage 41 and the bypass passage 44 to control the flow rate of the heat exchange passage 42 and the flow rate of the bypass passage 44 ( 45) is installed.

The water supply passage 41 is provided with a water supply sensor 411 for outputting a signal corresponding to the flow of water from the upstream to the downstream, and a water supply thermistor 412 for outputting a signal corresponding to the water supply temperature. In the heat exchange path 42, water is heated by the combustion exhaust of the burner 2 through the heat exchanger 421 provided above the burner 2 in the combustion chamber 1 and having the fin 422, and the hot water. Becomes Downstream of the heat exchanger 421 in the heat exchange path 42, a tapping temperature thermistor 423 for outputting a signal corresponding to the tapping temperature is provided. The hot water supply passage 43 is provided with a hot water temperature thermistor 431 for outputting a signal corresponding to the hot water temperature downstream from the joining position with the bypass passage 44.

The control unit 5 is constituted by a microcomputer or the like, and includes a rotation speed measuring means 51, a target rotation speed setting means 52, a power feeding control means 53, a blockage degree measuring means 54, The first correction means 55, the determination means 56, the second correction means 571, the third correction means 572, and the combustion control means 58 are provided.

The rotation speed measuring means 51 measures the rotation speed of the fan 3. The target rotation speed setting means 52 sets the target rotation speed of the fan 3 corresponding to the required combustion amount of the burner 2 set by the combustion control means 58. The power supply control unit 53 controls the amount of power supplied to the fan 3 so that the rotation speed of the fan 3 matches the target rotation speed. The occlusion degree measuring means 54 is based on the fan power that is recognized as being supplied to the fan 3 by the power supply control means 53 when the rotation speed of the fan is constantly controlled. The degree of occlusion of the air passage from 11) to the exhaust port 12 is measured. The first correction means 55 corrects the target rotational speed of the fan 3 in correspondence with the degree of occlusion of the air passage.

The determination means 56 determines whether the power supply amount to the fan 3 by the power supply control means 53 is increased or not. After it is determined that the amount of power supply to the fan 3 cannot be increased, the second correction means 571 decreases and corrects the upper limit value of the target rotational speed of the fan 3 until at least it is determined that it can be increased. After determining that the amount of power supply to the fan 3 can be increased, the third correction means 572 incrementally corrects the upper limit value of the target rotational speed of the fan 3 until it is determined that the power cannot be increased. The combustion control means 58 sets the target combustion amount of the burner 2 in response to the setting of the hot water supply temperature by the remote control 6 or the like, or the gas supply amount to the burner 2 in response to the rotation speed of the fan 3. To control.

As shown in Fig. 2, the power supply control means 53 includes a power supply circuit 71 for generating and outputting a DC signal from a commercial AC power supply 70, a pulse circuit 72 for generating and outputting a pulse signal, and a pulse. The switching signal 73 intermittently outputs the DC signal generated by the power supply circuit 71 by inputting the pulse signal from the circuit 72, and the smoothing circuit 74 for smoothing the output of the switching circuit 73 and supplying it to the fan. ).

The pulse circuit 72 includes a target rotational speed signal output circuit 721, a fan current detection circuit 722, an OP amplifier (" predetermined circuit ") 723, an oscillation circuit 724, and a comparator ( 725 and the FET drive circuit 726 are used.

The switching circuit 73 is configured using the FET 731.

The target rotation speed signal output circuit 721 outputs a DC target rotation speed signal of a level corresponding to the target rotation speed set by the target rotation speed setting means 52. The fan current detection circuit 722 outputs a signal having a level corresponding to the current flowing in the fan 3. The OP amplifier 723 outputs a signal having a level corresponding to a deviation between the level of the target speed signal output from the target speed signal output circuit 721 and the signal output from the fan current detection circuit 722. The oscillation circuit 724 outputs a triangular wave signal (waveform signal) of a constant peak level at a constant cycle. The comparator 725 receives an output signal of the OP amplifier 723 and an output signal of the oscillation circuit 724, and outputs a pulse signal having a duty factor corresponding to the level of the output signal from the OP amplifier 723. . The FET drive circuit 726 outputs a signal of a level that turns on the FET 731 when the output from the comparator 725 is LOW, while the FET 731 is output when the output from the comparator 725 is HIGH. Outputs the signal of the level to be turned off.

The judging means 56 has a judging circuit 560 configured by using the comparator 561. The comparator 561 receives an output signal from the OP amplifier 723 and a DC signal having a peak level V1 of, for example, a triangular wave signal output from the oscillator circuit 724, and the latter signal level is the former. If the signal level is larger than the signal level, the signal of higher level is output than the reverse case.

The rotation speed measuring means 51 has a fan rotation speed circuit 510 for outputting a signal corresponding to the actual rotation speed of the fan 3.

The operation of the combustion apparatus having the above configuration will be described with reference to FIG. 3.

First, combustion of the burner 2 is started (s1). Specifically, the target combustion amount of the burner 2 is set by the combustion control means 58 in order to supply hot water of the hot water supply temperature set by the remote control 6. The target rotation speed setting means 52 sets the target rotation speed of the fan 3 based on the target combustion amount. In addition, the combustion control means 58 controls the energization amount of the governor proportional solenoid valve 212 in response to the measured rotation speed of the fan 3 by the rotation speed measurement means 51, so that the burner ( 2) Control the gas supply to the furnace. The gas supplied to the burner 2 is ignited by the igniter 23 through the ignition electrode 22, and the burner 2 is combusted by supplying combustion air from the fan 3.

In addition, the degree of occlusion measuring means 54 measures the degree of occlusion of the air passage that is changed due to clogging caused by dust or the like in the fin 422 of the heat exchanger 421. The occlusion degree to the air passage is measured by using the property that the power supply to the fan 3 is lowered even if the fan rotation speed is constant because the load on the fan 3 is reduced when the occlusion degree is increased. More specifically, when the fan speed is kept constant, the degree of occlusion to the air passage is measured based on the increase and decrease of the fan power recognized by the power supply control means 53 to be supplied to the fan 3.

In addition, the first correction means 55 increases and corrects the target rotational speed as the occlusion degree measured by the occlusion degree measurement means 54 is increased. The electric power corresponding to the target rotational speed which has been increased and corrected is supplied to the fan 3 by the power supply control means 53, so that the rotational speed of the fan 3 is controlled to match the target rotational speed. Then, the combustion air reduced by the increase in the degree of obstruction to the aeration is compensated to maintain the complete combustion state of the burner 2.

Further, the judging means 56 judges whether the power supply amount to the fan 3 is increased or not based on the following circuit characteristics (s2). That is, the DC signal output from the power supply circuit 71 becomes a pulse signal by ON / OFF of the switching circuit 73, is supplied to the smoothing circuit 74, and is then supplied to the fan 3. Therefore, the amount of power supplied to the fan 3 can be increased by increasing the duty factor of the pulse signal. However, when the duty factor reaches "1", it becomes impossible to increase at that time. Also, the duty factor of the pulse signal in the switching circuit 73 matches the duty factor of the pulse signal applied to the switching circuit 73 in the pulse circuit 72. Therefore, when the duty factor of the pulse signal generated by the pulse circuit 72 reaches "1", the amount of power supplied to the fan 3 becomes impossible to increase. In addition, the duty factor of the pulse signal generated by the pulse circuit 72 coincides with the time ratio at which the level of the triangular wave signal over one period oscillated by the oscillator circuit 724 is equal to or less than the level of the output signal from the OP amplifier 723. do. Therefore, when the peak level of the triangular wave signal oscillated by the oscillation circuit 724 falls below the level of the output signal from the OP amplifier 723, the amount of power supplied to the fan 3 becomes impossible to increase. In addition, when the peak level V1 of the triangular wave signal oscillated by the oscillation circuit 724 falls below the level of the output signal from the OP amplifier 723, the output of the comparator 561 constituting the determination circuit 560 is It is lower than ever. Therefore, the determination means 56 can determine whether the power supply amount to the fan 3 is increased by whether or not the output from the comparator 561 in the determination circuit 560 is reduced.

As the degree of obstruction to the air passage is gradually increased and the target rotational speed is gradually increased and corrected, the amount of power supplied to the fan 3 also gradually increases. Then, when it is determined by the determining means 56 that the power supply amount to the fan 3 cannot be increased (YES in s2), the target that the second correcting means 571 is corrected by the first correcting means 55 is determined. Decrease and correct the upper limit of the rotation speed (s3). At this time, the combustion control means 58 decreases and corrects the upper limit value of the target combustion amount of the burner 2 in accordance with the target rotational speed reduced and corrected by the second correction means 571.

Subsequently, the determination means 56 determines whether the power supply amount to the fan 3 is increased (s4). When the determination means 56 determines that the power supply amount to the fan 3 cannot be increased (NO in s4), the target rotation in which the second correction means 271 continue to be corrected by the first correction means 55 Decrease and correct the upper limit of the number (s3). On the other hand, when the determination means 56 determines that the amount of power supply to the fan 3 can be increased (YES in s4), the target rotation in which the third correction means 572 is corrected by the first correction means 55 is corrected. The upper limit of the number is increased and corrected (s5). At this time, the combustion control means 58 increases and corrects the upper limit value of the target combustion amount of the burner 2 in accordance with the target rotation speed which is increased and corrected by the third correction means 572. Then, the upper limit value of the target rotational speed is continuously increased and corrected until the power supply amount to the fan 3 reaches a limit that can be increased (NO in s6) (s4 and s5).

According to the combustion apparatus (hot water supply apparatus) of this embodiment, after the power supply amount to the fan 3 becomes impossible to increase, the upper limit of the target rotational speed of the fan 3 is reduced and corrected at least until it becomes an increaseable state ( S2 to s4 in FIG. 3). Therefore, in the case where the target rotational speed of the fan 3 is increased and corrected, a state capable of increasing and controlling the rotational speed of the fan 3 toward the target rotational speed is ensured. In other words, since the power supply to the fan 3 cannot be increased (as long as the degree of obstruction is not reduced), the rotation speed of the fan 3 can no longer be increased. The situation where the number of rotations of the fan 3 is increased by increasing and correcting the number can be avoided. In this way, incomplete combustion of the burner 2 can be suppressed as the power supply amount to the fan 3 is saturated.

Further, the second correction means 571 and the third correction means 572 are corrected so that the target rotational speed is within a controllable amount of power to the fan 3. Therefore, the situation where the fan power recognized as being supplied to the fan 3 by the power supply control means 53 and the actual fan power are shifted is avoided. That is, the situation in which the obstruction degree measurement means 54 is recognized and the fan power-fan rotation speed relationship corresponding to the target rotation speed after the correction is shifted from the actual relationship is avoided. In addition, the blockage degree to the air passage is accurately measured by the blockage degree measuring means 54. Moreover, the target rotation speed of the fan 3 corrected corresponding to the said degree of occlusion is set so that the combustion air required for complete combustion of the burner 2 can be supplied sufficiently. And the burned state 2 of burner 2 can be maintained reliably.

In addition, when the power supply amount to the fan 3 can be increased, the upper limit value of the target rotational speed of the fan 3 is increased and corrected until it cannot be increased (see s4 to s6 in FIG. 3). Therefore, by increasing and correcting the target rotational speed of the fan 3 to the limit that the power supply amount to the fan 3 cannot be increased further, the state in which the rotational speed of the fan 3 can be increased and controlled toward the target rotational speed is maximized. It can be secured by

Further, when the upper limit value of the target rotational speed of the fan 3 is reduced and corrected by the second correcting means 571, the upper limit value of the target combustion amount of the burner 2 is reduced and corrected by the combustion control means 58. When the upper limit value of the target rotational speed of the fan 3 is increased and corrected by the third correction means 572, the upper limit value of the target combustion amount of the burner 2 is increased and corrected by the combustion control means 58. Therefore, the target combustion amount of the burner 2 is excessively set in consideration of the rotational speed of the fan 3, and furthermore, the upper limit of the supply amount of the air for combustion, whereby the air for combustion becomes insufficient and the burner 2 It is possible to reliably prevent the situation of incomplete combustion.

In addition, in this embodiment, it was determined whether the power supply amount to the fan 3 was increased based on the output of the pulse signal from the pulse circuit 72 to the switching circuit 73. As another embodiment, the power supply circuit 71 ) May be determined whether or not the power supply amount to the fan 3 is increased in response to whether or not the output level of the? Is higher than the predetermined level from the output level from the smoothing circuit 74 to the fan 3.

According to another embodiment described above, the output level in the power supply circuit 71 is initially set higher than the output level to the fan 3, but the power supply capability by the power supply circuit 71 is reduced as the difference between the two output levels decreases. Based on the fact that this limit is approached, it is possible to determine whether the power supply amount to the fan 3 is increased. Here, in the "predetermined level", when the switching by the switching circuit 73 is not performed, the output signal is continuously supplied to the fan by the power supply circuit 71, not intermittently, but goes through the smoothing circuit 74 on the way. Means the level decrease of the output signal. In addition, the switching by the switching circuit 73 not being performed means that the power supply amount from the power supply circuit 71 to the fan 3 reaches the upper limit and cannot be increased. Therefore, when the difference between the two output levels decreases and becomes below the predetermined level, it can be determined that the power supply amount to the fan 3 cannot be increased.

Then, the upper limit of the target rotational speed of the fan 3 can be increased by the second correction means 571 based on the determination of whether the power supply amount to the fan 3 is increased. The reduction is corrected until it is obtained (see s2 to s4 in FIG. 3). The upper limit value of the target rotational speed of the fan 3 is increased and corrected to the limit by which the power supply amount to the fan 3 can be increased by the third correction means 572 (see s4 to s6 in FIG. 3). In addition, the combustion control means 58 corrects the upper limit of the target combustion amount of the burner 2 corresponding to the target rotational speed of the fan 3 having the corrected upper limit.

Therefore, the target combustion amount of the burner 2 is excessively set in consideration of the rotational speed of the fan 3, and furthermore, the upper limit of the supply amount of the air for combustion, whereby the air for combustion becomes insufficient and the burner 2 It is possible to reliably prevent the situation of incomplete combustion.

As described above, according to the present invention, it is possible to provide a combustion apparatus capable of suppressing incomplete combustion of a burner as the amount of power supplied to the fan is saturated.

Claims (9)

A burner provided in the aeration passage, a fan provided in the aeration passage for supplying combustion air to the burner, rotation speed measuring means for measuring the rotation speed of the fan, and a target of the fan in response to the combustion amount of the burner. A target speed setting means for setting the rotation speed, and controlling the amount of power supplied to the fan so that the rotation speed of the fan measured by the rotation speed measuring means matches the target speed set by the target speed setting means. The power supply control means, the occlusion degree measuring means for measuring the occlusion degree of the aeration path, and the target rotation speed setting means corresponding to the occlusion degree of the aeration path measured by the occlusion degree measurement means. A combustion apparatus comprising first correction means for correcting a target rotational speed of a fan, Determination means for determining whether the power supply amount to the fan is increased by the power supply control means; The target of the fan to be corrected by the first correction means until it is determined by the determination means that the power supply amount to the fan by the power supply control means cannot increase, at least until the power supply amount is determined to be increase. And a second correction means for reducing and correcting the upper limit of the rotational speed. The method according to claim 1, The occlusion degree measuring means, based on the fan power that is recognized as being supplied to the fan by the power supply control means when the fan rotation speed measured by the rotation speed measurement means is constant, Combustion apparatus, characterized in that for measuring. The method according to claim 1 or 2, The target rotation of the fan corrected by the first correction means until it is determined by the determination means that the power supply amount to the fan by the power supply control means can be increased, and then the power supply amount is determined to be impossible to increase. And a third correction means for incrementally correcting the upper limit of the number. The method according to claim 1 or 2, And a combustion control means for reducing and correcting the upper limit value of the target combustion amount of the burner when the upper limit value of the target rotational speed of the fan is decreased and corrected by the second correction means. The method according to claim 3, When the upper limit value of the target rotational speed of the fan is decreased and corrected by the second correction means, the upper limit value of the target combustion amount of the burner is decreased and corrected, and the upper limit value of the target rotational speed of the fan is increased and corrected by the third correction means. And a combustion control means for increasing and correcting the upper limit value of the target combustion amount of the burner. The method according to any one of claims 1 to 5, The power supply control means includes a power supply circuit for outputting a DC signal, a pulse circuit for outputting a pulse signal, a switching circuit for intermittently outputting a DC signal in the power supply circuit in response to a pulse signal output from the pulse circuit; And a smoothing circuit for supplying the fan after smoothing the output from the switching circuit to a signal of a predetermined level, And the judging means judges whether or not the pulse signal is output from the pulse circuit to the switching circuit, and determines that the amount of power supply to the fan cannot be increased when it is determined that the pulse signal is impossible to output. Combustion device. The method according to claim 6, The pulse circuit includes an oscillation circuit for oscillating a waveform signal having a constant peak level, and a predetermined circuit for outputting a signal having a level corresponding to a target rotational speed set by the target rotational speed setting means. The pulse signal is applied to the switching circuit in response to the difference in magnitude between the peak level of the oscillated waveform signal and the level of the DC control signal output from the predetermined circuit. The judging means judges whether or not the peak level of the waveform signal output from the oscillation circuit is equal to or less than the level of the signal output from the predetermined circuit, and when determined to be equal to or less than the level, from the pulse circuit to the switching circuit. A combustion device characterized in that it is determined that the pulse signal is impossible to output. The method according to any one of claims 1 to 5, The power supply control means includes a power supply circuit for outputting a DC signal, a switching circuit for intermittently outputting a DC signal in the power supply circuit in response to a pulse signal from the outside, and a signal having a predetermined level of output from the switching circuit. A smoothing circuit applied to the fan after smoothing to The judging means determines whether the output level of the DC signal applied from the power supply circuit to the switching circuit is greater than a predetermined level in comparison with the output level given to the fan via the smoothing circuit in the switching circuit. And determining that the supply current to the fan cannot increase when it is determined to be large. The method according to claim 6 or 7, The judging means determines whether the output level of the DC signal applied from the power supply circuit to the switching circuit is greater than a predetermined level in comparison with the output level given to the fan via the smoothing circuit in the switching circuit. And determining that the supply current to the fan cannot increase when it is determined to be large.