JP3054337B2 - Combustion equipment - Google Patents

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 a combustion apparatus of this type, when a supply / exhaust passage is blocked, poor combustion occurs. Therefore, it is desirable to stop the operation immediately before the combustion state becomes poor. For this reason, the inventors have detected a blocked state before the start of ignition, tried to perform ignition when there is no problem in the supply / exhaust passage, and tried to stop ignition when there was a problem in the supply / exhaust passage. . However, it is necessary to perform an operation to detect the closed state and determine the state each time the ignition is performed, so that the ignition is delayed even in a normal state. In particular, the water heater detects the flow of water and starts operation. Until that time, there was a problem that cold water continued to flow from the hot water tap.

[0003]

SUMMARY OF THE INVENTION The present invention solves such inconveniences, and can quickly avoid a poor combustion state caused by a blocked supply / exhaust passage, and does not cause a delay in ignition in a normal state. The purpose is to provide.

[0004]

In order to achieve the above object, the present invention provides a combustion chamber containing a burner, a supply / exhaust passage communicating with the combustion chamber, and supplying combustion air to the burner. A combustion fan, a degree of blockage detecting means for detecting a degree of blockage of the supply / exhaust passage, and a combustion fan that rotates at a predetermined rotation speed before the start of ignition of the burner, and performs combustion corresponding to a required combustion amount during combustion. Fan control means for controlling the combustion fan so that an air amount can be obtained at a target rotational speed; and ignition for stopping ignition when a degree of blockage detected by the degree of blockage detection means before starting ignition is equal to or higher than a reference value. In the combustion apparatus provided with the pre-clogging monitoring means, the pre-ignition clogging monitoring means is configured to perform the operation when the degree of clogging detected by the degree of clogging detection during combustion is equal to or less than a reference value, that is, when the degree of clogging is not affected. The Itoki, characterized by omitting the monitor before the next ignition start.

Further, according to the present invention, even when ignition is possible in accordance with a blocked state, combustion is continued by correcting the fan speed in accordance with the blocked state, and operation is stopped when the blocked state progresses. In this case, the correction value calculating means for calculating a 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 When the value is equal to or more than 1 predetermined value and less than a second predetermined value, the target rotation speed is corrected by the correction value,
When the rotation speed is equal to or more than a predetermined value and less than a third predetermined value, the target rotation speed is corrected with the correction value and the combustion capacity is limited. When the rotation speed is equal to or more than the third predetermined value, safe driving means is provided. When 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 fan current detecting means for detecting a fan current flowing through the combustion fan, and rotational speed detecting means for detecting the rotational speed of the combustion fan, wherein the degree of blockage detection is The degree of blockage is detected based on the decrease rate of the detected fan current with respect to the reference current in the normal state of the combustion fan during the ignition, and the pre-ignition blockage monitoring means detects when the detected fan current at the predetermined rotation speed is equal to or less than a threshold value. The ignition may be stopped.

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

When detecting the degree of obstruction based on the fluctuation of the detected fan current, the fan current detecting means detects the fan current at predetermined time intervals, and based on the average value of a predetermined number of detected fan currents, determines the degree of obstruction. Preferably, the detecting means detects the degree of blockage.

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 the start of ignition. When the pre-obstruction monitoring means omits the monitoring, when the monitoring is performed at the first predetermined rotation speed,
It is preferable to rotate at a second predetermined rotation speed.

[0010] The degree of blockage detecting means is not limited to the above configuration, but detects the amount of air blown from the combustion fan and compares it with a target amount of blown air corresponding to the required amount of combustion. The degree may be detected, and the correction value calculating means may use means for calculating a correction value for correcting the rotation speed of the combustion fan in accordance with the degree of blockage.

[0011]

According to the present invention, the pre-ignition blockage monitoring means comprises:
When the degree of blockage detected by the degree of blockage detection is equal to or less than the reference value, that is, when the degree of blockage is not affected, monitoring before the start of the next ignition is omitted. On the other hand, when the degree of blockage detected by the degree of blockage detection means is equal to or greater than the reference value, that is, when the degree of blockage is hindered, monitoring is performed before the start of next ignition. Accordingly, the pre-ignition obstruction monitoring means operates only before the start of the next ignition only when the obstruction state is obstructed.

When the ignition is possible in accordance with the closed state, the fan speed is corrected in accordance with the closed state to continue the combustion, and when the closed state is advanced, the operation is stopped. The values are provided in three stages. When the value is lower than the first predetermined value and less than the second predetermined value, the operation is continued by correcting the fan speed. When the value is medium and higher than the second predetermined value and less than the third predetermined value, the fan speed is corrected. In addition, the combustion capacity is limited and the operation is stopped. When the combustion capacity becomes equal to or higher than the third predetermined value, the operation is stopped. In this case, before the start of the next ignition, since the combustion is not hindered in the region where the correction value is lower than the second predetermined value, the operation of the pre-ignition blockage monitoring means is omitted,
In a region where the correction value is more than the second predetermined value and hinders combustion,
Make it work.

[0013] 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 a change in 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 decrease rate of the detected fan current during combustion, and the correction value is determined by the second value.
In an area less than the predetermined value, the operation of the high occlusion monitoring means is omitted.

When judging the closed state before the start of ignition based on such a change in the fan current, the fan current is detected at every predetermined number of sampling times, and the detected fan current is averaged. Eliminate malfunctions.

When the combustion fan is rotated at a predetermined rotation speed to detect a blocked state before the start of ignition, the combustion fan is rotated at a second rotation speed higher than the first predetermined rotation speed. In the state where the pre-ignition obstruction monitoring means is operated, the obstruction state may further temporarily proceed due to gusts or the like. In this case, a state of immediate operation stop may occur. By doing so, it is possible to have a margin for detecting the degree of blockage, and to avoid operation stoppage in a temporarily blocked state due to gusts or the like.

On the other hand, when the operation of the pre-ignition obstruction monitoring means is omitted, that is, when the obstruction state is not hindered, the pre-ignition obstruction monitoring means is rotated at a first rotational speed lower than the second rotational speed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, a water heater A as 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 wire N are provided.

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

The bypass pipe 13 has an upstream inlet connected to the other outlet of the electric water flow control device 15 and a downstream end connected to an upstream side of the tapping pipe 14 (downstream end of the heat exchanger pipe 12). The hot water pipe 14 is provided with a freezing prevention heater 141 for preventing freezing, a hot water thermistor 142 for detecting hot water temperature, an overpressure safety valve / water tap 143, and a hot water tap 144 for discharging hot water from the upstream side to the downstream side. Has been established.

The electric water flow control device 15 is energized and controlled by the actuator control unit 58, and outputs the amount of water passing through the water supply pipe 11, the amount of heat exchange water passing through the heat exchanger tube 12, and the hot water without passing through the heat exchanger tube 12. Bypass pipe 13 reaching pipe 14
To control the ratio to the amount of bypass water flowing through the water. Hot water tap 14
Reference numeral 4 denotes a faucet for adjusting the amount of hot water discharged from a faucet provided in a kitchen or a bathroom. The water amount sensor 112 is of an impeller type and sends out a pulse corresponding to the amount of water flowing in the water supply pipe 11.

The gas burner 2 of the three-stage switching type is disposed inside the combustion housing 3 and is supplied with combustion air by the combustion fan 4 and is supplied with gas by the gas pipe 6 to perform forced combustion. This gas pipe 6 has an original solenoid valve 6
1, governor proportional solenoid valve 62, capacity switching solenoid valve 63,
64 are provided. In addition, 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 sensing switch for operating a freeze prevention heater 141.

The tapping thermistor 142 detects the tapping temperature,
The water supply thermistor 113 is for detecting the water supply temperature. In addition, the can body thermistor 123 is provided to detect the temperature of the water that has passed through the heat exchanger 121.

The performance switching electromagnetic valves 63 and 64 are energized and controlled by the actuator control unit 58, and the combination # 63, 64 of opening and closing is both open, only 63 is open, 64
Only by opening the valve｝, the supply amount to the gas burner 2 is switched in three stages. Note that the frame rod 23 is provided with a burner corresponding to the capacity switching electromagnetic valve 63 so that the combustion flame can be detected both when the capacity switching electromagnetic valve 63 is opened and when only the capacity switching electromagnetic valve 64 is opened. It is disposed over a burner corresponding to the capacity switching electromagnetic valve 64.

The governor proportional solenoid valve 62 is energized and controlled by the actuator control unit 58, shows an opening corresponding to the amount of energization, and continuously varies the amount of gas flowing through the gas pipe 6. Therefore, the capacity switching solenoid valves 63 and 64 and the governor proportional solenoid valve 6
Combination of 2 and 3 makes it possible to increase the combustion control width and to perform fine control.

The combustion housing 3 has a combustion exhaust gas 3
An exhaust duct 32 that collects and discharges 1 to the outside is extended. The remote controller L includes a push button switch for instructing a change in the set temperature, 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 detecting unit 51 for detecting a fan current, a rotational speed detecting unit 52 for detecting the rotational speed of the combustion fan 4, Control unit for feedback control of the air flow and a high blockage monitoring unit (for example, a blockage state of 90% or more) of a supply / exhaust passage (exhaust duct 32 or the like) before the start of ignition. A correction value calculating unit 55 that detects a blocked state of the supply / exhaust passage during combustion and calculates a correction value of a rotation speed corresponding to the blocked state, and an ignition corresponding to the blocked state. It includes a safe operation unit 56 for stopping or limiting hot water supply capacity (combustion capacity), a calorie calculation unit 57, and an actuator control unit 58 for controlling the original solenoid valve 61 and the like.

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 detection of the fan current is performed as follows.
Perform a total of 5 times every 0.5 seconds. The rotation speed detection unit 52
The fan rotation speed is detected based on the output of a rotation speed sensor 42 (such as a Hall element) provided in the combustion fan 4.

Before the start of ignition, the fan control unit 53 determines a fan predetermined rotation speed (2700 rpm) which is a pre-purge rotation speed.
To rotate the combustion fan 4, and at the time of ignition, the ignition speed (22
The rotation of the combustion fan 4 at 50 rpm) and the rotation of the combustion fan 4 during the hot water supply so that the combustion fan 4 rotates at a preset target rotation speed corresponding to the required combustion amount calculated by the calorie calculation unit 57. 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 rotation speed is increased by multiplying the target rotation speed by the correction value H. As will be described later, at the time of the first hot water supply after the power is turned on, and at the next time when the high blockage monitoring unit 54 operates, the fan control unit 53 sets the fan predetermined rotation speed which is the pre-purge rotation speed before the start of ignition. The predetermined rotation speed (270
The combustion fan 4 is rotated at a rotation speed (3000 rpm) larger than 0 rpm).

During the pre-purge before the start of ignition, the high current monitoring unit 54 makes the fan current detection unit 51
The average value of the detected fan currents is a threshold (for example, 400
mA) or less (for example, the blockage rate is equivalent to 90% or more), and the actuator controller 58 is instructed to stop ignition.

The correction value calculation unit 55 detects the closed state of the supply / exhaust passage based on the rate of decrease in the detected fan current with respect to the predetermined rotation speed of the combustion fan 4 during hot water supply (during combustion), and by the following method. , A correction value H (degree of blockage) corresponding to the blocked state of the supply / exhaust passage is calculated. Therefore, in the present embodiment, the correction value calculation unit 55 also functions as a means for detecting the degree of blockage.

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

I ₁ and I ₂ are the auxiliary value lines 8 respectively.
5, and the fan current value at the reference value line 82, I ₀
Is a fan current value detected by the fan current detection unit 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 {(a / b) -1} × α + 1. Here, α is a constant of 1 or less.

FIG. 6 shows the relationship between the correction value H and the closing ratio.
When the correction value H calculated by the correction value calculation unit 55 is equal to or more than 1.0 (first predetermined value) and less than 1.1 (second predetermined value), the safe driving unit 56 sets the target rotation speed to the correction value H. Amend, 1.1
When the value is not less than (second predetermined value) and less than 1.2 (third predetermined value), the target rotation speed is corrected by the correction value H, and the maximum hot water supply capacity (combustion capacity) is set to No. 14 to No. 10 (No. 16 hot water supply). In the case of a heater, and instructs to stop the combustion when it is 1.2 (third predetermined value) or more.

The calorific value calculating section 57 includes a water supply thermistor 113
Is calculated based on the detected water supply temperature detected by the water supply sensor and the detected water supply amount detected by the water amount sensor 112.

The water heater A of this embodiment determines the target rotation speed of the combustion fan 4 based on the required amount of combustion, and controls the amount of power to the governor proportional solenoid valve 62 according to the actual rotation speed of the combustion fan 4. When the target rotation speed is corrected, 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 because the so-called fan-first control is performed. So that the required amount of combustion
The capacity switching solenoid valves 63 and 64 are switched to control the amount of electricity supplied to the governor proportional solenoid valve 62. Further, the electric water flow control device 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 flowcharts shown in FIGS.

The user presses the operation switch 71 to put the water heater main body K into the operating state, and opens the hot water tap 144.
In STEP1, it is determined whether or not the detected water amount W ≧ 2.7 l / min. If the detected water amount W ≧ 2.7 l / min (YES), the process proceeds to STEP2.

In STEP 2, it is determined whether the flag F is 1 or not. If F = 1 (NO), STEP 3
If the flag F = 1 (YES), the flow proceeds to STEP4. If the correction value H was less than 1.1 and the closing ratio was less than 60% at the time of the last hot water supply, the flag is set to 0, and the initial operation after turning on the power, or when the correction value H is 1.1 or more, The flag is set to 1 when the closing rate corresponds to 60% or more. At the time of the first operation after the power is turned on, since the blocked state has not been detected yet, the high blocked
The flag is set to 1 because it is desirable to detect the occlusion state by 4.

In STEP 3, the combustion fan 4 is set to the predetermined first
Is instructed to rotate for 2 seconds at the (pre-purge) rotation speed (2700 rpm), and then proceeds to STEP7. 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, monitoring of the blocking 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, since the correction value H is 1.1 or more (corresponding to a blockage rate of 60% or more) in the first operation after the power is turned on or in the previous combustion, STEP 4 Instructs the combustion fan 4 to rotate at a predetermined second (prepurge) rotation speed (3000 rpm) higher than the first predetermined rotation speed, and in STEP 5
Then, the high blockage monitoring unit 54 detects the blockage state of the supply / exhaust passage. Specifically, the fan current detector 51
Compares the average value of the fan current detected five times in total every 0.5 seconds with a threshold value (for example, 400 mA; equivalent to a blocking rate of 90%).

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

In STEP 7, the igniter 22 is activated, and the solenoid valve {source solenoid valve 61, capacity switching solenoid valve 63,
Is opened, the governor proportional solenoid valve 62 is operated (ignition opening) to ignite the gas burner 2, and the operation proceeds to STEP8.
The rotation speed of the combustion fan 4 at this time is determined by the ignition rotation speed (2250 rpm) corresponding to the ignition opening of the governor proportional solenoid valve 62.
m).

In step 8, the flame is detected by the flame rod 23. If the flame is detected (YES), the STE
Proceed to P9. In step 9, the igniter 22 is stopped, and
Proceed to TEP10.

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

On the basis of 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 calculator 57 calculates the required combustion amount at which the tap water temperature reaches the set temperature. The fan control unit 53 performs feedback control of the combustion fan 4 based on the output of the rotation speed sensor 42 so that the combustion fan 4 rotates at a preset target rotation speed according to the required combustion amount calculated by the calorific value 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 corrected. When divided by H, the capacity switching solenoid valves 63 and 64 are switched to control the amount of electricity supplied to the governor proportional solenoid valve 62 so as to obtain the combustion amount. Further, the electric water flow control device 15 is controlled as necessary to adjust the distribution ratio.

In STEP 11, the correction value calculating section 5 is continued.
5 to detect a blocked state during combustion and calculate a correction value H according to the blocked state of the supply / exhaust passage.
Proceed to 2.

In 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
When the correction value H is less than 1.1 (NO), the flow proceeds to STEP 21 described later.

At STEP 13, the flag F is set to 1, and the routine 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 normal maximum hot water supply capacity is No. 16, the capacity is limited as follows.

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

If the maximum hot water supply capacity is less than No. 10 in STEP 14 (YES; the correction value H is equal to or greater than 1.2 and the blockage rate is equal to or greater than 80%), the process proceeds to STEP 22 to be described later.
If the number is 0 or more (NO), the flow proceeds to STEP16.

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 STEP10.

In STEP 17, the solenoid valve ｛the original solenoid valve 61,
The performance switching solenoid valves 63 and 64 are closed, the governor proportional solenoid valve 62 is deactivated (minimum opening), and the combustion fan 4
Is stopped, and the process proceeds to STEP18. In STEP 18, the process waits until hot water tap 144 is opened.

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 obstruction rate is 90% or more} is displayed, and the operation is stopped.

In STEP 21 described above, the flag F is set to 0, and the process proceeds to STEP 16 without changing the maximum hot water supply capacity. In step 22 described above, the solenoid valve {source solenoid valve 61, capacity switching solenoid valves 63 and 64} are closed, the governor proportional solenoid valve 62 is deactivated (minimum opening), the combustion fan 4 is stopped, and Proceed to. At step 23, the error display “99” is displayed on the display 72.
Instruct so that 0% or more is displayed, and stop the operation.

According to the apparatus of the above-described embodiment, if the correction value H calculated by the correction value calculation unit 55 is less than 1.1 (less than 60% closing rate) during hot water supply, before the start of the next ignition. The configuration is such that the high blockage monitoring performed by the high blockage monitoring unit 54 is omitted, and the gas burner 2 is quickly ignited.

For this reason, the correction value H is less than 1.1 (blockage rate 6
(Less than 0%), ignition delay 点火 0.5s × 5 times =
Since 2.5 seconds can be prevented and the hot water supply is restarted promptly, the outflow of cold water at the start of hot water supply can be prevented, resulting in excellent usability. When the correction value H is 1.1 or more and less than 1.2, the monitoring is performed by the high blockage monitoring unit 54 before ignition. Therefore, when the correction value H is less than 1.1, the high blockage monitoring is not performed. Omission does not cause a decrease in security.

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

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

Further, the supply / exhaust passage is blocked (blockage rate 60
% Or more and less than 80%) according to the maximum hot water supply capacity No. 16
The configuration is limited to Nos. 4 to 10. For this reason, the hot water supply apparatus A can be used with a safe hot water supply capacity according to the closed state of the supply / exhaust passage.

Before the start of ignition, the fan control unit 53
When rotating the combustion fan 4, when operating the high blockage monitoring unit 54, the rotation speed when not operating (for example, 27
00 rpm) (for example, 3000 rpm).
m).

Therefore, it is possible to have a margin for detecting the degree of blockage, and when the high blockage monitoring unit 54 is operating,
The hot water supply operation is not stopped even if the closed state is temporarily advanced due to gusts or the like.

The pre-purge rotation speed (for example, 2700 rpm) in a normal case where the high blockage monitoring unit 54 is not operated
m) may be set to a high rotation speed (for example, 3000 rpm) as in the case of operating the high occlusion monitoring unit 54. However, if it is set to a high rotation speed, it is considerably larger than the ignition rotation speed (for example, 2200 rpm). Therefore, it takes time to change from the pre-purge rotation speed to the ignition rotation speed, and there is a disadvantage that the ignition is delayed. However, in this embodiment, the rotation speed of the prepurge when the high blockage monitoring unit 54 is not operated is a value suitable for ignition as in the conventional case.
There is no delay in ignition.

The present invention includes the following embodiments in addition to the above embodiments. a. In the above-described embodiment, the setting temperature is variable, but may be fixed (for example, 60 ° C., 75 ° C.). b. It may be adopted in a hot water supply device without a bypass pipe or a hot water supply device of a main stop type. c. In the above embodiment, a hot water supply device is shown as a combustor, but the present invention may be applied to a hot air heater or the like. d. In the above embodiment, the closing ratio is detected based on the correction value. However, the closing ratio may be directly detected based on the decreasing ratio of the fan current. e. In the above embodiment, when the high blockage monitoring unit 54 monitors blockage, the fan current is detected five times in total every 0.5 seconds, but the number and time can be changed as appropriate.
Also in the high blockage monitoring section 54, the degree of blockage may be detected by the correction value calculation section 55 in the same manner as during 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 performed during the prepurge, but may be performed irrespective 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 is performed in the next combustion. The gas burner is quickly ignited without monitoring by the pre-obstruction 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 quickly restarted, which is excellent in usability.

If the correction value calculated by the correction value calculation 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, and
The gas burner is ignited quickly. For this reason, when the correction value is less than the second predetermined value, ignition delay can be prevented, and combustion is performed quickly, so that the usability is excellent.
If the correction value is equal to or larger than the second predetermined value, monitoring by the pre-ignition blockage monitoring means before the start of ignition is performed.

When the fan control means rotates the combustion fan at a predetermined number of revolutions before the start of ignition, when the pre-ignition blockage monitoring means is operated, it is rotated at a predetermined number of revolutions greater than when it is not operated. . For this reason, it is possible to have a margin in detecting the degree of blockage, and malfunctions such that operation is stopped even if the blockage state temporarily advances due to gusts or the like while the blockage monitoring unit before ignition is operating. Can be prevented.

Before the start of ignition, the fan current tends to drift because it is immediately after the start of rotation of the fan. However, the fan current detecting means detects the fan current at predetermined time intervals and calculates an average value of a predetermined number of detected fan currents. Since the high obstruction monitoring means detects the obstruction state of the exhaust path based on this, it is possible to accurately detect the obstruction state of the exhaust path although it takes some time.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a hot water supply apparatus according to one embodiment of the present invention.

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

FIG. 3 is a flowchart illustrating the operation of the water heater.

FIG. 4 is a flowchart illustrating the operation of the water heater.

FIG. 5 is a graph showing the relationship between the number of revolutions of the combustion fan and the fan current.

FIG. 6 is a graph showing a relationship between a closing ratio and a correction value.

[Explanation of symbols]

A Hot water supply device (combustor) 1 Heat exchange water channel 2 Gas burner 3 Combustion housing 4 Combustion fan 32 Exhaust duct 51 Fan current detection unit (fan current detection unit) 52 Revolution detection unit (revolution detection unit) 53 Fan control unit (fan) Control means) 54 High blockage monitoring unit (blocking monitoring unit before ignition) 55 Correction value calculation unit (blockage degree detection unit, correction value calculation unit) 56 Safe driving unit (safe driving unit)

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Hideki Kitagawa 2-26, Fukuzumi-cho, Nakagawa-ku, Nagoya-shi, Aichi Rinnai Corporation (56) References JP-A-5-164323 (JP, A) JP-A-8 -68533 (JP, A) JP-A-8-14545 (JP, A) JP-A-5-157231 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23N 5/24 104 F23N 3/08 F23N 5/18 101

Claims (6)

(57) [Claims] 1. A combustion chamber for 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 detecting a degree of blockage of the supply / exhaust passage. A degree detecting means, and rotating the combustion fan at a predetermined speed before the start of ignition of the burner, and setting the combustion fan to a target speed at which a combustion air amount corresponding to a required combustion amount is obtained during combustion. A combustion device comprising: a fan control means for controlling; and a pre-ignition clogging monitoring means for stopping ignition when a degree of clogging detected before ignition is equal to or more than a reference value, wherein the pre-ignition clogging monitoring means comprises: When the degree of blockage detected by the degree of blockage detection means is equal to or less than a reference value, monitoring before the start of next ignition is omitted. 2. A correction value calculating means for calculating a correction value of a fan speed corresponding to a degree of blockage of a supply / exhaust passage during combustion detected by said degree of blockage detection means, and wherein the calculated correction value is a first predetermined value. When the value is equal to or more than a value and less than a second predetermined value, the target rotation speed is corrected by the correction value, and when the value is equal to or more than a second 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, A safe driving means for stopping combustion at a third predetermined value or more, wherein when the correction value is less than the second predetermined value, the pre-ignition blockage monitoring means omits monitoring before the next ignition start. The combustion device according to claim 1, characterized in that: 3. A combustion engine comprising: fan current detection means for detecting a fan current flowing through the combustion fan; and rotation speed detection means for detecting a rotation speed of the combustion fan. 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. The combustion device 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 decrease ratio of a detected fan current with respect to a reference fan current when a combustion fan during combustion is normal. Value calculating means for correcting the target rotation speed with the correction value when the calculated correction value is equal to or more than a first predetermined value and less than a second predetermined value, and correcting the target rotation speed when the calculated correction value is equal to or more than a second predetermined value and less than a third predetermined value And a safe driving means for limiting the combustion capacity and stopping combustion when the correction value is equal to or more than a third predetermined value, and when the correction value is less than a second predetermined value, the pre-ignition blockage monitoring means. 4. The combustion apparatus according to claim 3, wherein monitoring before the start of the next ignition is omitted. 5. The apparatus according to claim 1, wherein said fan current detecting means detects a fan current at predetermined time intervals, and said blocking degree detecting means detects a blocking degree based on an average value of a predetermined number of detected fan currents. Item 5. 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 at a second predetermined rotation speed higher than the first predetermined rotation speed before the start of ignition of the burner. The combustion device according to any one of claims 1 to 5, wherein when the pre-occlusion monitoring unit omits the monitoring, the rotation is performed at a first predetermined rotation speed, and when the monitoring is performed, the rotation is performed at a second predetermined rotation speed.