JPH08247452A - Combustion device - Google Patents

Abstract

PURPOSE: To provide a combustion device in which a poor combustion state generated under a closed state of each of a gas supplying passage and a gas discharging passage can be avoided rapidly and a delay in ignition is not produced under a normal condition. CONSTITUTION: There are provided a closing degree sensing means 55 for sensing a closing degree of each of a gas supplying passage and a gas discharging passage for a combustion chamber in response to a decreasing rate of a detected fan current value in respect to a reference fan current under a normal state of a combustion fan 4 during combustion, and a pre-ignition closed state monitoring means 54 for prohibiting ignition in the case that the closing degree detected by a closing degree sensing means 55 is more than a reference value. The pre-ignition closed state monitoring means 54 eliminates a monitoring operation before performing an ignition starting of a next time when the detected closed degree is less than the reference value.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In this type of combustion apparatus, when the supply / exhaust passage is blocked, defective combustion occurs. Therefore, it is desirable to stop the operation immediately before the combustion state becomes poor. Therefore, the inventors have tried to detect the blocked state before the start of ignition, cause the ignition to be performed when the supply / exhaust passage is not obstructed, and stop the ignition when the supply / exhaust passage is obstructed. . However, since it is necessary to detect the closed state at each ignition and determine the state, ignition is delayed even during normal operation, and in particular, the water heater detects the flow of water and starts operation. Until then, there was a problem that cold water continued to flow from the hot water tap.

[0003]

SUMMARY OF THE INVENTION The present invention eliminates such inconvenience, can quickly avoid a poor combustion state caused by a closed state of the supply / exhaust passage, and does not cause ignition delay during normal operation. The purpose is to provide.

[0004]

In order to achieve the above object, the present invention provides a combustion chamber accommodating a burner, a supply / exhaust passage communicating with the combustion chamber, and a combustion air supply to the burner. A combustion fan, a degree-of-blockage detecting means for detecting the degree of blockage of the supply / exhaust passage, a combustion fan which is rotated at a predetermined rotation speed before the start of ignition of the burner, and a combustion engine which corresponds to a required combustion amount during combustion. Fan control means for controlling the combustion fan so that an air amount reaches a target rotation speed, and ignition for stopping ignition when the degree of obstruction detected by the degree-of-obstruction detection means before starting ignition is a reference value or more. In the combustion apparatus including the pre-blocking monitoring means, the pre-ignition blockage monitoring means, when the blockage degree detected by the blockage degree detection means during combustion is a reference value or less, that is, the blockage degree is hindered. The Itoki, characterized by omitting the monitor before the next ignition start.

Further, according to the present invention, even when ignition is possible depending on the closed state, the fan speed is corrected according to the closed state to continue combustion, and when the closed state progresses, the operation is stopped. In this case, the correction value calculating means for calculating the correction value of the fan rotation speed corresponding to the degree of blockage of the supply / exhaust passage during combustion detected by the degree of blockage detection means, and the calculated correction value are When the value is greater than or equal to 1 predetermined value and less than the second predetermined value, the target rotation speed is corrected with the correction value,
When the value is equal to or more than a predetermined value and less than a third predetermined value, the target rotation speed is corrected by the correction value and the combustion capacity is limited, and when the third predetermined value or more, safe driving means for stopping combustion is provided. Is less than the second predetermined value, the pre-ignition blockage monitoring means may omit the monitoring before the start of the next ignition.

Further, the present invention comprises a fan current detecting means for detecting a fan current flowing through the combustion fan, and a rotation speed detecting means for detecting a rotation speed of the combustion fan, wherein the blockage degree detecting means is a burner. Detects the degree of blockage based on the rate of decrease of the detected fan current with respect to the reference current during normal operation of the combustion fan, the pre-ignition blockage monitoring means, when the detected fan current at the predetermined rotation speed is less than or equal to a threshold value. The ignition may be stopped.

Further, in this case, according to the present invention, the fan speed corresponding to the degree of blockage of the supply / exhaust passage during combustion is based on the rate of decrease of the detected fan current with respect to the reference fan current during normal operation of the combustion fan during combustion. Correction value calculating means for calculating a correction value of, and when the calculated correction value is greater than or equal to a first predetermined value and less than a second predetermined value, the target rotation speed is corrected by the correction value, and the second predetermined value or more and the third predetermined value or more. When the correction value is less than the second predetermined value, the target rotation speed is corrected by the correction value and the combustion capacity is limited, and when the correction value is less than the second predetermined value, the combustion operation is stopped. The pre-ignition blockage monitoring means omits monitoring before the start of the next ignition.

When the degree of blockage is detected by such fluctuations in the detected fan current, the fan current detecting means detects the fan current at every predetermined time, and the degree of blockage is determined based on the average value of the predetermined number of detected fan currents. It is preferable that the detection means detects the degree of blockage.

Before the ignition is started, the fan control means causes the combustion fan to rotate at a first predetermined rotation speed or a second predetermined rotation speed higher than the first predetermined rotation speed so that the ignition is performed. When the front blockage monitoring means omits monitoring, when monitoring is performed at the first predetermined rotation speed,
It is preferable to rotate at the second predetermined rotation speed.

The blockage degree detecting means is not limited to the above-mentioned configuration, but detects the blown air amount obtained from the combustion fan and compares it with the target blown air amount corresponding to the required combustion amount to block it. The degree may be detected, and the correction value calculation means may use a means for calculating a correction value for correcting the rotation speed of the combustion fan corresponding to the degree of blockage.

[0011]

According to the present invention, the pre-ignition blockage monitoring means comprises:
When the degree of obstruction detected by the degree-of-obstruction detection means is equal to or less than the reference value, that is, when the degree of obstruction does not interfere, the monitoring before the start of the next ignition is omitted. On the other hand, when the degree of obstruction detected by the degree-of-obstruction detection means is equal to or greater than the reference value, that is, when the degree of obstruction is impaired, monitoring is performed before the start of the next ignition. Therefore, the pre-ignition blockage monitoring means operates before the start of the next ignition only when there is a problem in the blocked state.

Even when ignition is possible depending on the closed state, the fan rotation speed is corrected according to the closed state to continue combustion, and when the closed state progresses, the operation is stopped. The value is set in three steps, and the fan rotation speed is corrected when the value is lower than the first predetermined value and lower than the second predetermined value, and the operation is continued, and the fan rotation speed is corrected when the value is higher than the second predetermined value and lower than the third predetermined value which are moderate. In addition, the combustion capacity is limited to cope with it, and when the value becomes equal to or higher than the high third predetermined value, the operation is stopped. In this case, before the start of the next ignition, combustion does not occur in a region where the correction value is lower than the second predetermined value, so the operation of the pre-ignition blockage monitoring means is omitted.
In a region where the correction value is equal to or greater than the second predetermined value and combustion is hindered,
To operate.

The degree of blockage is determined, for example, by the fan control means rotating the combustion fan at a predetermined rotation speed before ignition and changing the detected fan current at the predetermined rotation speed.

Then, a correction value of the fan speed corresponding to the degree of blockage of the supply / exhaust passage during combustion is calculated based on the rate of decrease of the detected fan current during combustion, and the correction value is the second value.
The operation of the high occlusion monitoring means is omitted in a region less than the predetermined value.

When determining the blocked state before the start of ignition based on such a change in the fan current, the fan current is detected every predetermined number of sampling times, and the fan current is averaged to cause temporary noise or the like. Eliminate malfunctions.

When the combustion fan is rotated at a predetermined rotation speed in order to detect the blocked state before the start of ignition, it is rotated at a second rotation speed higher than the first predetermined rotation speed. While the pre-ignition blockage monitoring means is in operation, the blockage may further progress temporarily due to gusts of wind. In this case, the operation may be stopped immediately. By doing so, there is a margin in detecting the degree of blockage, and operation stop in a temporarily blocked state due to gusts or the like is avoided.

On the other hand, when the pre-ignition blockage monitoring means omits the operation, that is, when there is no problem in the blockage state, the pre-ignition blockage monitoring means is rotated at a first rotation speed lower than the second rotation speed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the hot water supply device A that is a combustor is
A water heater main body K installed outdoors and a remote controller L installed in a kitchen or the like and connected to the water heater main body K by a two-wire N.

The water heater main body K comprises a heat exchange channel 1, a gas burner 2, a combustion housing 3, a combustion fan 4 for introducing combustion air into the combustion housing 3, and a control unit 5.
And

The heat exchange channel 1 includes a water supply pipe 11 and a heat exchanger pipe 1.
2, a bypass pipe 13, and a hot water outlet pipe 14. The upstream side of the water supply pipe 11 is connected to the water supply, and the downstream side is connected to the inlet of the electric water flow controller 15. The water supply pipe 11 has a water filter / drainage plug 11 from the upstream side.
1, a water amount sensor 112, and a water supply thermistor 113 are arranged. The heat exchanger tube 12 has an upstream inlet side connected to one outlet side of the electric water amount control device 15, and the gas burner 2
Passing through the heat exchanger 121 disposed above, the downstream outlet side is connected to the hot water outlet pipe 14. The heat exchanger 121 is
Heat the water passing through it. An overheat prevention device 122 is provided on the outer wall, and the can body thermistor 1 is provided on the downstream outlet side.
23 are provided.

The upstream side of the bypass pipe 13 is connected to the other outlet side of the electric water amount control device 15, and the downstream end thereof is connected to the upstream side of the hot water discharge pipe 14 (the downstream end side of the heat exchanger pipe 12). A freezing prevention heater 141 for preventing freezing, a hot water discharge thermistor 142 for detecting a hot water temperature, an overpressure safety valve / drain plug 143, and a hot water tap 144 for discharging hot water are provided in the hot water discharge pipe 14 from the upstream side to the downstream side. It is set up.

The electric water amount controller 15 is energized and controlled by the actuator control unit 58, and the amount of water passing through the water supply pipe 11 and the amount of heat exchange water passing through the heat exchanger pipe 12 and the hot water discharge without passing through the heat exchanger pipe 12 are performed. Bypass pipe 13 reaching pipe 14
Control the ratio with the amount of bypass water flowing through. Hot water tap 14
Reference numeral 4 is a faucet for adjusting the amount of hot water discharged from a faucet arranged in a kitchen or a bathroom. The water amount sensor 112 is an impeller type, and sends out a pulse according to the amount of water flowing through the water supply pipe 11.

The three-stage capacity switching type gas burner 2 is arranged in the combustion housing 3, and combustion air is sent by the combustion fan 4, and gas is supplied by the gas pipe 6 and combusted. In this gas pipe 6, the original solenoid valve 6
1, a governor proportional solenoid valve 62, and a capacity switching solenoid valve 63,
64 are provided. Reference numeral 21 is an ignition electrode, 22 is an igniter, 23 is a frame rod for detecting a combustion flame, 24 is a temperature fuse for preventing overheating, and 25 is a low temperature detection switch for operating the freeze prevention heater 141.

The tap water thermistor 142 detects the tap water temperature,
The water supply thermistor 113 is for detecting the water supply temperature. Further, the can body thermistor 123 is arranged to detect the temperature of the water that has passed through the heat exchanger 121.

Energization of the capacity switching solenoid valves 63 and 64 is controlled by the actuator control unit 58, and a combination of opening and closing valves {63 and 64 are both open, only 63 is open, 64
Only the valve is opened} to switch the supply amount to the gas burner 2 in three stages. It should be noted that the frame rod 23 has a burner corresponding to the capacity switching electromagnetic valve 63 so that combustion flame can be detected regardless of whether only the capacity switching electromagnetic valve 63 is opened or only the capacity switching electromagnetic valve 64 is opened. It is arranged across a burner corresponding to the capacity switching solenoid valve 64.

The governor proportional solenoid valve 62 is energized and controlled by the actuator control unit 58, exhibits an opening corresponding to the energizing amount, and continuously changes the amount of gas flowing through the gas pipe 6. Therefore, the capacity switching solenoid valves 63, 64 and the governor proportional solenoid valve 6
Combining 2 and 2 allows a wider combustion control range and finer control.

Combustion housing 3 has combustion exhaust gas 3 at the top.
An exhaust duct 32 for collecting 1 and discharging it is extended. The remote controller L includes a push button switch for instructing a set temperature change, an operation switch 71 for instructing start and stop of operation, a display 72, an operation lamp, a combustion lamp, and the like.

As shown in FIG. 2, the control unit 5 having a microcomputer includes a fan current detector 51 for detecting a fan current, a rotation speed detector 52 for detecting the rotation speed of the combustion fan 4, and a combustion fan 4. And a high blockage monitoring unit for monitoring high blockage (eg, 90% or more blocked state) of the supply / exhaust passage (exhaust duct 32, etc.) before starting ignition (before ignition of the present invention. (Corresponding to blockage monitoring means) 54, a correction value calculation unit 55 that detects a blockage state of the supply / exhaust passage during combustion, and calculates a correction value of the rotation speed corresponding to the blockage state, and an ignition corresponding to the blockage state. A safe operation unit 56 for stopping and limiting hot water supply capability (combustion capability), a heat amount calculation unit 57, and an actuator control unit 58 for controlling the original solenoid valve 61 and the like are provided.

The fan current detecting section 51 includes a current sensor 41.
The fan current is detected based on the output of. When the high blockage monitoring unit 54 performs blockage monitoring, the fan current is detected by
Perform every 5 seconds for a total of 5 times. The rotation speed detection unit 52
The fan rotation speed is detected based on the output of the rotation speed sensor 42 (Hall element or the like) arranged on the combustion fan 4.

The fan control section 53 has a predetermined fan rotation speed (2700 rpm) which is the prepurge rotation speed before ignition is started.
The combustion fan 4 is rotated by, and the ignition speed (22
The combustion fan 4 is rotated at 50 rpm), and the output of the rotation speed sensor 42 is output so that the combustion fan 4 rotates at a preset target rotation speed according to the required combustion amount calculated by the heat quantity calculation unit 57 during hot water supply. Feedback control based on.
When the correction value calculated by the correction value calculation unit 55 described later is 1 or more and less than 1.2, the target rotation speed is multiplied by the correction value H to increase the rotation speed. As will be described later, at the time of the first hot water supply after the power is turned on and when the high blockage monitoring unit 54 operates next time, the fan control unit 53 sets the fan predetermined rotation speed, which is the pre-purge rotation speed before ignition start, to Predetermined rotation speed (270
The combustion fan 4 is rotated at a rotation speed (3000 rpm) larger than 0 rpm.

In the high blockage monitoring section 54, the fan current detection section 51 makes a total of 5 intervals every 0.5 seconds during the pre-purge before the start of ignition.
The average value of the fan current detected twice is a threshold value (for example, 400
mA) or less (for example, the blockage rate is equal to or greater than 90%), the actuator control unit 58 is instructed to stop the ignition.

The correction value calculation unit 55 detects the closed state of the supply / exhaust path based on the rate of decrease of the detected fan current with respect to the predetermined number of revolutions of the combustion fan 4 during hot water supply (combustion). , A correction value H (degree of blockage) corresponding to the blocked state of the supply / exhaust passage is calculated. Therefore, in this embodiment, the correction value calculation unit 55 also serves as a unit for detecting the degree of blockage.

In FIG. 5, reference numeral 81 is a steady line showing the fan rotation speed-fan current characteristic when not blocked, and reference numeral 82 shows the fan rotation speed-fan current characteristic at the correction value of 1.0 for correction. Is a reference value line for determining whether or not, and 83 is the fan speed at the correction value 1.1.
A reference value line that indicates the fan current characteristic and determines whether or not to limit the hot water supply capacity. Reference numeral 84 indicates a fan rotation speed-fan current characteristic at a correction value of 1.2, which is a reference for determining whether or not to stop hot water supply. Reference numeral 85 is a value line, and reference numeral 85 is an auxiliary value line showing the fan rotation speed-fan current characteristic determined by an experiment for obtaining the correction value.

Further, I ₁ and I ₂ are auxiliary value lines 8 respectively.
5, and the fan current value on the reference value line 82, I ₀
Is the fan current value detected by the fan current detector 51, a is I ₂ -I ₁ , and b is I ₀ -I ₁ . Then, the correction value calculation unit 55 obtains the correction value H by the formula of {(a / b) -1} × α + 1. Note that α is a constant of 1 or less.

FIG. 6 shows the relationship between the correction value H and the blocking rate.
When the correction value H calculated by the correction value calculation unit 55 is 1.0 (first predetermined value) or more and less than 1.1 (second predetermined value), the safe driving unit 56 sets the target rotation speed as the correction value H. Corrected 1.1
When it is (second predetermined value) or more and less than 1.2 (third predetermined value), the target rotation speed is corrected with the correction value H, and the maximum hot water supply capacity (combustion capacity) is No. 14 to No. 10 (No. 16 hot water supply). (In the case of a vessel), and in the case of 1.2 (third predetermined value) or more, stop combustion is instructed.

The calorific value calculator 57 is provided with a water supply thermistor 113.
Based on the detected supply water temperature detected by the water supply amount and the detected supply water amount detected by the water amount sensor 112, the required combustion amount at which the outlet hot water temperature detected by the outlet hot water thermistor 142 reaches the set temperature is calculated.

The water heater A of this embodiment determines the target rotation speed of the combustion fan 4 based on the required combustion amount, and controls the energization amount of the governor proportional solenoid valve 62 according to the actual rotation speed of the combustion fan 4. Since the control is a so-called fan preceding type control, the actuator control unit 58 cancels the correction by dividing the rotation speed detected by the rotation speed detection unit 52 by the correction value H when the target rotation speed is corrected. So that the required combustion amount is
The capacity switching solenoid valves 63 and 64 are switched to control the amount of electricity supplied to the governor proportional solenoid valve 62. Also, the electric water flow controller 15 is controlled as necessary to adjust the distribution ratio.

Next, the operation of the control unit 5 of the water heater A will be described with reference to the flow charts shown in FIGS.

The user presses the operation switch 71 to bring the water heater main body K into an operating state and opens the hot water tap 144.
In STEP 1, it is determined whether or not the detected water amount W ≧ 2.7 liters / minute. If the detected water amount W ≧ 2.7 liters / minute (YES), the process proceeds to STEP 2.

In STEP 2, it is determined whether or not the flag F is 1, and if F = 1 is not satisfied (NO), STEP 3
If the flag F = 1 (YES), the process proceeds to STEP 4. If the correction value H was less than 1.1 and the blockage rate was less than 60% when hot water was supplied last time, the flag is set to 0, and the correction value H is 1.1 or more during the first operation after the power is turned on. The flag is set to 1 when the blockage rate corresponds to 60% or more. During the first operation after the power is turned on, the high blockage monitoring unit 5 has not been detected yet because the blockage state has not been detected yet.
The flag is set to 1 because it is desirable to detect a blocked condition by 4.

In STEP 3, the combustion fan 4 is set to the first
(Pre-purge) rotation speed (2700 rpm) is instructed to rotate for 2 seconds, and the process proceeds to STEP 7. In this case, since the correction value H is less than 1.1 (corresponding to a blocking rate of less than 60%) in the previous combustion, the monitoring of the blocked state before the start of ignition is omitted, and the process proceeds to step 7 of the ignition operation.

On the other hand, when the flag is set to 1, the correction value H is 1.1 or more (corresponding to a blockage rate of 60% or more) at the first operation after the power is turned on or at the previous combustion, so STEP4. Then, the combustion fan 4 is instructed to rotate at a predetermined second (prepurge) rotation speed (3000 rpm) higher than the first predetermined rotation speed, and STEP 5
Then, the high blockage monitoring unit 54 detects the blockage state of the supply / exhaust passage. Specifically, the fan current detection unit 51 before starting ignition.
However, the average value of the fan current detected five times every 0.5 seconds is compared with a threshold value (for example, 400 mA; corresponding to a blocking rate of 90%).

In STEP 6, if average value ≦ threshold value (YE
In S), the blockage rate is considered to be 90% or more, and the process proceeds to STEP 19 in which the combustion fan 4 described later is stopped. If the average value> threshold value (NO), the blockage rate is regarded as less than 90% and the STE
Proceed to P7.

In STEP 7, the igniter 22 is activated and the solenoid valve {original solenoid valve 61, capacity switching solenoid valve 63,}
Is kept open, the governor proportional solenoid valve 62 is operated (ignition opening degree) to ignite the gas burner 2, and the process proceeds to STEP 8.
The rotation speed of the combustion fan 4 at this time is the ignition rotation speed (2250 rp) corresponding to the ignition opening degree of the governor proportional solenoid valve 62.
m).

In step 8, combustion flame is detected by the flame rod 23, and if detected (YES), STE
Proceed to P9. Stop the igniter 22 at STEP 9
Proceed to TEP10.

In STEP 10, the correction value calculation unit 55 detects the blocked state during combustion, and proportional control is performed according to the blocked state.

Based on the detected water supply temperature detected by the water supply thermistor 113 and the detected water supply amount detected by the water amount sensor 112, the calorie calculation unit 57 calculates the required combustion amount at which the hot water outlet temperature reaches the set temperature. The fan control unit 53 feedback-controls the combustion fan 4 based on the output of the rotation speed sensor 42 so as to rotate at a preset target rotation speed according to the required combustion amount calculated by the heat quantity calculation unit 57. When the correction value calculated by the correction value calculation unit 55 is 1 or more and less than 1.2,
The target rotation speed is corrected by multiplying the target rotation speed by the correction value H.

The actuator control unit 58 calculates the combustion amount back based on the rotation speed detected by the rotation speed detection unit 52 (if the target rotation speed is corrected, the rotation speed detected by the rotation speed detection unit 52 is a correction value). Divide by H}, the capacity switching solenoid valves 63 and 64 are switched so that the combustion amount is obtained, and the amount of electricity to the governor proportional solenoid valve 62 is controlled. Also, the electric water flow controller 15 is controlled as necessary to adjust the distribution ratio.

In STEP 11, the correction value calculation unit 5 continues.
5 detects the closed state during combustion, and calculates the correction value H according to the closed state of the supply / exhaust passage, and STEP 1
Go to 2.

At STEP 12, it is determined whether or not the correction value H is 1.1 or more (corresponding to a blocking rate of 60% or more). If the correction value H is 1.1 or more (YES), STEP 13
If the correction value H is less than 1.1 (NO), the process proceeds to STEP 21, which will be described later.

In STEP 13, the flag F is set to 1, and the process proceeds to step 14.

In STEP 14, the hot water supply capacity (combustion capacity) is controlled according to the closed state of the supply / exhaust passage. For example, when the maximum hot water supply capacity under normal conditions is No. 16, the capacity is limited as follows.

The maximum hot water supply capacity is limited to No. 14 when the blocking rate is 60% or more and less than 65%. The maximum hot water supply capacity is limited to No. 12 when the blocking rate is 65% or more and less than 70%. Blockage rate 70% or more 7
The maximum hot water supply capacity is limited to No. 11 with less than 5%. Occlusion rate 7
The maximum hot water supply capacity is limited to No. 10 at 5% or more and less than 80%.

In STEP 14, if the maximum hot water supply capacity is less than No. 10 (YES; correction value H is 1.2 or more, blockage rate is 80% or more), proceed to STEP 22, which will be described later, and 1
If the number is 0 or more (NO), the process proceeds to STEP 16.

In STEP 16, it is determined whether or not the detected water amount W ≦ 2.3 liters / minute. If W ≦ 2.3 liters / minute (YES), the process proceeds to STEP 17 and W> 2.3 liters / minute. In the case of (NO), the process returns to STEP 10.

In STEP 17, the solenoid valve (former solenoid valve 61,
The capacity switching solenoid valves 63, 64} are closed, the governor proportional solenoid valve 62 is deactivated (minimum opening), and the combustion fan 4
Stop and proceed to STEP 18. In STEP 18, wait until the hot water tap 144 opens.

When the combustion fan 4 is stopped (the ignition operation is stopped) in STEP 19, the process proceeds to STEP 20. In STEP 20, the error display “9” is displayed on the display 72.
0 ”{the supply / exhaust passage blockage rate is 90% or more} is instructed to be displayed, and the operation is stopped.

In STEP 21, the flag F is set to 0, the maximum hot water supply capacity is not changed, and the process proceeds to STEP 16. In STEP 22 described above, the solenoid valve {original solenoid valve 61, capacity switching solenoid valves 63, 64} is closed, the governor proportional solenoid valve 62 is deactivated (minimum opening), the combustion fan 4 is stopped, and STEP 23 Proceed to. In STEP 23, the error indication “99” is displayed on the display device 72 (the supply / exhaust passage blockage rate is 8).
0% or more} is displayed, and the operation is stopped.

According to the apparatus of the above-described embodiment, when the correction value H calculated by the correction value calculation unit 55 is less than 1.1 (blocking rate less than 60%) during hot water supply, before starting the next ignition. The high obstruction monitoring by the high obstruction monitoring unit 54 is omitted, and the gas burner 2 is quickly ignited.

Therefore, the correction value H is less than 1.1 (blocking rate 6
Ignition delay (0.5s × 5 times =
2.5 seconds} can be prevented, and hot water supply can be restarted promptly, so that cold water can be prevented from flowing out at the start of hot water supply, which is excellent in usability. When the correction value H is 1.1 or more and less than 1.2, the high blockage monitoring unit 54 is configured to perform monitoring before ignition. Therefore, when the correction value H is less than 1.1, high blockage monitoring is performed. There is no reduction in safety due to omission.

When the correction value H at the time of first hot water supply after the power is turned on or at the time of previous hot water supply is 1.1 or more, the fan current detection unit 51 detects the fan current every 0.5 seconds five times. The high blockage monitoring unit 54 based on the average value of the detected fan current five times.
Is a configuration for detecting a closed state of the supply / exhaust passage.

For this reason, when it is necessary to detect high blockage, a slight detection time (2.5 seconds) is required, but the fan current drifts immediately after the combustion fan 4 starts rotating and before ignition starts. Also, it is possible to accurately detect the blocked state of the supply / exhaust passage.

Furthermore, the supply / exhaust passage is blocked (blocking rate 60
% Or more, less than 80%), depending on the maximum hot water supply capacity 16
The configuration is limited to No. 4 to No. 10. Therefore, the hot water supply device A can be used with a safe hot water supply capacity according to the closed state of the supply / exhaust passage.

Before the ignition is started by the fan controller 53,
When the combustion block 4 is rotated, when the high blockage monitoring unit 54 is operated, the rotation speed when not operating (for example, 27
Rotation speed greater than 00 rpm (eg 3000 rp)
Rotated in m).

Therefore, there is a margin in detecting the degree of blockage, and when the high blockage monitor 54 is operated,
The hot water supply operation is not stopped even if the closed state progresses temporarily due to gusts or the like.

It should be noted that the rotation speed of the prepurge in the normal case where the high blockage monitoring section 54 is not operated (for example, 2700 rp
m) may be set to a high rotation speed (for example, 3000 rpm) as in the case of operating the high blockage monitoring unit 54, but when set to a high rotation speed, it is considerably higher than the ignition rotation speed (for example, 2200 rpm). Therefore, it takes time to change from the prepurge rotation speed to the ignition rotation speed, and there is a disadvantage that ignition is delayed. However, in the present embodiment, since the pre-purge rotation speed when the high blockage monitoring unit 54 is not operated is a value suitable for ignition as in the conventional case,
Ignition is never delayed.

The present invention includes the following embodiments in addition to the above embodiments. a. Although the set temperature is variable in the above embodiment, it may be fixed (for example, 60 ° C. or 75 ° C.). b. It may be used for a hot water supply device without a bypass pipe or a hot water supply device of the original stop type. c. Although the hot water supply device is shown as the combustor in the above-described embodiment, the present invention may be applied to a hot air heater or the like. d. In the above embodiment, the blockage rate is detected based on the correction value, but the blockage rate may be directly detected based on the reduction rate of the fan current. e. In the above-described embodiment, when the high blockage monitoring unit 54 performs blockage monitoring, the fan current is detected five times every 0.5 seconds, but the number of times and the time can be changed as appropriate.
Further, also in the high blockage monitoring unit 54, the degree of blockage may be detected by the correction value calculation unit 55 as in the case of combustion. f. The present invention may be applied to a combustion fan provided on the exhaust passage side. g. In the above embodiment, the blockage monitoring by the high blockage monitoring unit 54 is shown during the prepurge, but it may be carried out independently of the prepurge.

[0068]

According to the present invention, when the degree of blockage detection means detects that the degree of blockage of the exhaust passage is equal to or less than the reference value during the current combustion, the ignition before the start of ignition at the next combustion. The gas burner is quickly ignited by omitting the monitoring by the front blockage monitoring means. Therefore, when the degree of blockage is equal to or less than the reference value, ignition delay can be prevented and combustion is restarted promptly, which is excellent in usability.

When the correction value calculated by the correction value calculating means is less than the second predetermined value, the monitoring by the pre-ignition blockage monitoring means before the start of ignition is omitted in the next combustion.
This is a configuration for quickly igniting the gas burner. Therefore, when the correction value is less than the second predetermined value, ignition delay can be prevented and combustion is performed promptly, which is excellent in usability.
If the correction value is greater than or equal to the second predetermined value, the pre-ignition blockage monitoring means monitors the ignition before starting the ignition.

When the fan control means rotates the combustion fan at a predetermined rotation speed before the start of ignition, when the pre-ignition blockage monitoring means is operated, it is rotated at a predetermined rotation speed higher than when it is not operated. . Therefore, it is possible to allow a sufficient degree of detection of the degree of blockage, and in the state where the pre-ignition blockage monitoring means is operating, even if the blockage state temporarily progresses due to gusts, etc. Can be prevented.

Before ignition is started, the fan current is apt to drift because it is immediately after the fan starts rotating. However, the fan current detecting means detects the fan current at every predetermined time, and determines the average value of the predetermined number of detected fan currents. Since the high blockage monitoring means is configured to detect the blockage state of the exhaust path based on the above, it is possible to accurately detect the blockage state of the exhaust path although it takes some time.

[Brief description of drawings]

FIG. 1 is a schematic view of a water heater according to an embodiment of the present invention.

FIG. 2 is a block diagram of the vicinity of a control unit of the water heater device.

FIG. 3 is a flowchart illustrating an operation of the hot water supply device.

FIG. 4 is a flowchart illustrating an operation of the hot water supply device.

FIG. 5 is a graph showing a rotation speed-fan current characteristic of a combustion fan.

FIG. 6 is a graph showing a relationship between a blocking rate and a correction value.

[Explanation of symbols]

A hot water supply device (combustor) 1 heat exchange channel 2 gas burner 3 combustion housing 4 combustion fan 32 exhaust duct 51 fan current detection unit (fan current detection unit) 52 rotational speed detection unit (rotation speed detection unit) 53 fan control unit (fan Control unit) 54 High blockage monitoring unit (pre-ignition blockage monitoring unit) 55 Correction value calculation unit (blocking degree detection unit, correction value calculation unit) 56 Safe driving unit (safe driving unit)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideki Kitagawa 2-26 Fukuzumicho, Nakagawa-ku, Nagoya, Aichi Prefecture

Claims (6)

[Claims] 1. A combustion chamber accommodating a burner, a supply / exhaust passage communicating with the combustion chamber, a combustion fan for supplying combustion air to the burner, and a blockage for detecting the degree of blockage of the supply / exhaust passage. The degree detecting means and the combustion fan are rotated at a predetermined number of revolutions before the start of ignition of the burner, and during combustion, the combustion fan is set so that the amount of combustion air corresponding to the required combustion amount reaches a target number of revolutions. In a combustion device comprising fan control means for controlling, and pre-ignition blockage monitoring means for stopping ignition when the degree of blockage detected before ignition is equal to or greater than a reference value, the pre-ignition blockage monitoring means is Further, when the degree of blockage detected by the degree of blockage detection means is equal to or less than a reference value, the monitoring before the start of the next ignition is omitted. 2. A correction value calculating means for calculating a correction value of a fan rotation speed corresponding to a degree of blockage of a supply / exhaust passage during combustion detected by the degree of blockage detecting means, and the calculated correction value is a first predetermined value. When the value is greater than or equal to the value and less than the second predetermined value, the target rotation speed is corrected with the correction value, and when the value is greater than or equal to the second predetermined value and less than the third predetermined value, the target rotation speed is corrected with the correction value and the combustion capacity is limited, Safe operation means for stopping combustion at a third predetermined value or more, and when the correction value is less than a second predetermined value, the pre-ignition blockage monitoring means omits monitoring before the start of the next ignition. The combustion apparatus according to claim 1, wherein the combustion apparatus is a combustion apparatus. 3. A fan current detection means for detecting a fan current flowing through the combustion fan, and a rotation speed detection means for detecting a rotation speed of the combustion fan, wherein the blockage degree detection means includes the combustion during combustion. The degree of blockage is detected based on the rate of decrease of the detected fan current with respect to the reference fan current when the fan is normal, and the pre-ignition blockage monitoring means stops ignition when the detected fan current at the predetermined rotation speed is less than or equal to a threshold value. The combustion apparatus according to claim 1, wherein: 4. A correction for calculating a correction value of a fan rotation speed corresponding to a degree of blockage of a supply / exhaust passage during combustion, based on a rate of decrease of a detected fan current with respect to a reference fan current when a combustion fan during combustion is normal. A value calculation means, and when the calculated correction value is greater than or equal to a first predetermined value and less than a second predetermined value, the target rotation speed is corrected with the correction value, and when the calculated correction value is greater than or equal to the second predetermined value and less than a third predetermined value, the target rotation speed is Is provided with the correction value and the combustion capacity is limited, and safe driving means for stopping the combustion at a third predetermined value or more is provided. When the correction value is less than the second predetermined value, the pre-ignition blockage monitoring means is provided. The combustion apparatus according to claim 3, wherein the monitoring before the start of the next ignition is omitted. 5. The fan current detecting means detects a fan current at predetermined time intervals, and the blockage degree detecting means detects the blockage degree based on an average value of a predetermined number of detected fan currents. The combustion device according to Item 3 or 4. 6. The fan control means rotates the combustion fan at a first predetermined rotation speed or a second predetermined rotation speed higher than the first predetermined rotation speed before starting the ignition of the burner, and the ignition control is performed. The combustion apparatus according to any one of claims 1 to 5, wherein when the front blockage monitoring means omits monitoring, the pre-blocking monitoring unit rotates at a first predetermined rotation speed, and when monitoring is performed at a second predetermined rotation speed.