JP3031856B2 - Air volume adjustment method using boiler inverter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting the air flow of a boiler in which the air flow is adjusted by combining a blower in which the rotation speed of a blower motor is adjusted using an inverter and a damper for adjusting the air flow from the blower. It is about.

[0002]

2. Description of the Related Art In the case of a boiler in which combustion control is performed at three positions of high combustion, low combustion, and stop, it is necessary to adjust the supply amount of combustion air in accordance with the fuel supply amount. As a method of adjusting the air volume, there has been proposed a method of adjusting the rotation speed of a blower motor using an inverter. When adjusting the air volume using an inverter, the effect of reducing power consumption and noise can be obtained by lowering the rotation speed of the blower motor.However, in order to obtain the air volume for ignition, Due to the problem that it takes time, adjustment of the amount of air generated by the rotation speed of the blower motor and adjustment of the amount of air flow by the opening of the damper are combined as described in JP-A-5-10522, and the first low combustion at ignition and after ignition is performed. During this period, a method has been proposed in which the rotation speed of the blower motor is kept high and the damper opening is set to the low combustion side.

In the case where the air volume is adjusted by the inverter, there is a problem that it takes a long time from when the operation frequency change command is output to the inverter until the rotation speed of the blower motor reaches the target speed. When igniting a boiler, combustion always occurs at low combustion after ignition,
If the change of the damper opening and the rotation speed of the blower motor are changed during the first low combustion when the combustion is not stable, the rotation speed of the blower motor may not decrease even if the damper is fully opened. Because the problem that the flame is blown out by the increase of the air volume occurs,
It was necessary to take a method of reducing the rotation speed of the blower motor for the first time in the second low combustion after the high combustion was once performed. Therefore, during low combustion immediately after ignition, the rotation speed of the blower motor remains high, and during that time, the effects of reducing power consumption and reducing noise were not obtained. Also,
When switching the combustion amount between low combustion and high combustion, it takes time until the air volume is actually changed even if a command to change the operating frequency of the inverter is output. There was a problem that the air-fuel ratio collapsed.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a boiler in which the air volume is adjusted by an inverter, that the air volume and the state of combustion are always kept appropriately and that the air volume is changed during low combustion immediately after ignition. Another object of the present invention is to reduce the rotation speed of the blower motor, reduce power consumption and reduce noise more than before, and prevent the air-fuel ratio from being lost when the combustion amount is changed.

[0005]

An inverter for controlling the frequency of electric power supplied to the blower motor is connected to the blower motor, and a blower for adjusting the amount of generated air by controlling a rotation speed of the blower motor, and a blower from the blower. In a boiler with a damper that adjusts the air flow by limiting the amount of air that is blown, when changing the fan motor rotation speed and damper opening immediately after ignition or when switching the combustion amount, or changing the fuel supply amount, the inverter The change of the damper opening or the change of the fuel supply amount is performed after a lapse of a fixed delay time from the output of the change command. Alternatively, a frequency detecting device for detecting the operating frequency sent from the inverter to the blower motor is provided, and the operating frequency detected by the frequency detecting device reaches the switching set value after the change command is output to the inverter. Then, change the damper opening or change the fuel supply amount.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of one embodiment of the present invention. The boiler 1 is provided with a combustion device 2 at an upper portion, and combustion is performed by fuel sent through a fuel supply pipe 3 and combustion air sent from a blower 6. The control of the combustion amount is performed by adjusting the fuel supply amount and the air flow amount. The fuel supply amount is controlled by a first solenoid valve 4 and a second solenoid valve 5 provided in the fuel supply pipe 3. Solenoid valve 4 and second
When the solenoid valve 5 is closed, the combustion is stopped, when only the first solenoid valve 4 is opened, low combustion occurs, and when the first solenoid valve 4 and the second solenoid valve 5 are opened, high combustion occurs. An inverter 8 is connected to the blower motor 7, the rotation speed of the blower motor 7 is changed according to the operation frequency output from the inverter 8, and the operation frequency output from the inverter 8 is detected by the frequency detection device 11. . A damper 9 is provided in an air path connecting the blower 6 and the boiler 1, and the opening degree of the damper 9 is set to fully open, open for ignition, and fully closed. Combustion control such as opening and closing of the first solenoid valve 4 and the second solenoid valve 5 and air volume adjustment by the inverter 8 or the damper 9 are performed by the combustion device 2, the first solenoid valve 4, the second solenoid valve 5, the inverter 8, the damper 9, Respectively connected to the frequency detection device 11,
This is performed by the control device 10 having the timer device 12 therein. The timer device 12 is a variable timer, and can change a set value.

FIG. 2 is a time chart showing the situation of combustion and air volume adjustment in one embodiment of the present invention.
2 shows the control performed by the control unit. When the operation switch of the stopped boiler is turned on, the control device 10 fully opens the damper 9 in order to perform pre-purge, and a command of a purge frequency (for example, 60 Hz) is sent to the inverter 8. The operating frequency sent from the motor to the blower motor 7 is defined as the purge frequency. During the pre-purge, the amount of air sent from the blower to the boiler is set to a maximum. When the pre-purge is completed, the opening of the damper 9 is changed to the ignition opening, and the amount of air is reduced by the damper 9. With the air volume adjusted by the damper, a voltage is applied to the ignition trust to generate a spark, and the first solenoid valve 4 is opened to ignite with low combustion. After a lapse of a set time (for example, 10 seconds) from the ignition, the inverter 8 supplies a low combustion frequency (for example, 23 Hz).
The inverter 8 starts shifting the operating frequency output to the blower motor 7 from the purge frequency to the low combustion frequency. At this time, the operation of the timer device 12 is started, and the elapsed time from the frequency shift command to the inverter 8 is detected. When the damper delay timing set time (T1) has elapsed since the start of the shift of the operating frequency, the opening degree of the damper 9 is shifted to the fully open state.

When switching the combustion amount from low combustion to high combustion, the inverter 8 supplies a high combustion frequency (for example, 55H).
z), and the inverter 8 controls the blower motor 7
The shift of the operating frequency output to the low combustion frequency to the high combustion frequency is started. The operating frequency output from the inverter 8 to the blower motor 7 is detected by the frequency detecting device 11, and the detected operating frequency reaches the switching set value set between the high combustion frequency and the low combustion frequency. Then, the second solenoid valve is opened to start high combustion. The same applies when switching the combustion amount from high combustion to low combustion,
The air volume is adjusted by the inverter 8, and when the operating frequency detected by the frequency detector 11 reaches the switching set value, the second solenoid valve 5 is closed to reduce combustion. The set value for switching is set to a different value so that the combustion amount is switched from low combustion to high combustion and the combustion amount is switched from high combustion to low combustion. May be. Also, when the combustion is switched, the timer device 12 is switched from when the frequency switching command is output to the inverter 8.
, The elapsed time may be detected, and if the frequency detected by the frequency detection device 11 does not reach the switching set value even after the set time has elapsed, an abnormal output may be performed.

When the operation switch is turned off, a purge command is input to the inverter 8, and the inverter 8 shifts the operation frequency output to the blower motor 7 to the purge frequency. The opening of the damper 9 is set to the opening for ignition in order to stop low combustion, and after closing the second solenoid valve 5, the first solenoid valve 4 is closed to stop combustion. When the post-purge in which only air is blown for a certain period of time ends, the opening of the damper 9 is fully closed, and the blower 6 is stopped.

FIG. 3 is a time chart showing the state of combustion and air volume adjustment in another embodiment of the present invention, showing the control performed by the control device 10. When the operation switch of the boiler is turned on, the opening degree of the damper 9 is fully opened, a pre-purge is performed using the operating frequency sent from the inverter 8 to the blower motor as a purge frequency, and the opening degree of the damper 9 is set to the opening degree for ignition. By changing the value, the air volume is adjusted and ignition is performed. After a lapse of a set time (for example, 10 seconds) from the ignition, the inverter 8 supplies a low combustion frequency (for example, 23 Hz).
And the inverter 8 starts to shift the operating frequency output to the blower motor 7 from the purge frequency to the low combustion frequency. The operating frequency output from the inverter 8 to the blower motor 7 is detected by the frequency detecting device 11, and the detected operating frequency is set to the switching set value set between the high combustion frequency and the low combustion frequency. When reaching, the opening degree of the damper 9 is started to be fully opened.

When switching the combustion amount from low combustion to high combustion, the inverter 8 supplies a high combustion frequency (for example, 55H).
z), and the inverter 8 starts shifting the operation frequency output to the blower motor 7 from the low combustion frequency to the high combustion frequency. At this time, the operation of the timer device 12 is started, and when the solenoid valve opening / closing delay timing set time (T2) elapses after the shift of the operating frequency is started,
The second solenoid valve 5 is opened to start high combustion. The same applies to the case where the combustion amount is switched from high combustion to low combustion. The air flow is adjusted by the inverter 8 and the solenoid valve opening / closing delay timing setting time (T2) after the shift of the operating frequency is started.
After elapse, the second solenoid valve 5 is closed to reduce combustion. In addition,
The solenoid valve opening / closing delay timing setting time is set to different values so that the combustion amount is switched from low combustion to high combustion, and the combustion amount is switched from high combustion to low combustion. May be set.

[0012]

By implementing the present invention, it is possible to appropriately maintain the air volume and combustion of the boiler for which the air volume is adjusted by the inverter, and to reduce the rotation speed of the blower motor immediately after ignition to save power and reduce noise. It is possible to prevent the air-fuel ratio from being lost when the combustion amount is changed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a time chart of one embodiment of the present invention.

FIG. 3 is a time chart of another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 boiler 2 combustion device 3 fuel supply pipe 4 first solenoid valve 5 second solenoid valve 6 blower 7 blower motor 8 inverter 9 damper 10 control device 11 frequency detection device 12 timer device

Claims (6)

(57) [Claims] An operating frequency output from the inverter to the blower motor by connecting an inverter set to a high combustion frequency and a low combustion frequency to the blower motor and sending a frequency command to the inverter. To change
The amount of air is adjusted by changing the rotation speed of the blower motor, and by controlling the amount of fuel supplied to the boiler, high combustion
In a boiler in which combustion control is performed at three positions of low combustion and stop, a frequency detection device for detecting an operation frequency sent from an inverter to a blower motor is provided, and the combustion amount of the boiler is switched between high combustion and low combustion. First, send a command to the inverter to change the operating frequency,
When the operating frequency detected by the frequency detecting device reaches a set value for switching, the amount of fuel supplied to the boiler is changed. 2. An operating frequency output from the inverter to the blower motor by connecting an inverter in which a high combustion frequency and a low combustion frequency are set to the blower motor and sending a frequency command to the inverter. To change
The amount of air is adjusted by changing the rotation speed of the blower motor, and by controlling the amount of fuel supplied to the boiler, high combustion
In a boiler in which combustion control is performed at three positions of low combustion and stop, a timer device for detecting an elapsed time is provided,
When switching the boiler combustion amount between high combustion and low combustion, first send a command to the inverter to change the operation frequency, and detect the elapsed time from the command output to the inverter with a timer device. When the detected elapsed time reaches the delay time T2, the fuel supply amount to the boiler is changed, and the delay time T2 when switching the combustion amount of the boiler from the high combustion to the low combustion, and the low combustion Wherein the delay time T2 for switching from the combustion mode to the high combustion mode is set to different values so as to be optimal in each case. 3. An operating frequency output from the inverter to the blower motor by connecting an inverter in which a high combustion frequency and a low combustion frequency are set to the blower motor and sending a frequency command to the inverter. To change
The amount of air is adjusted by changing the rotation speed of the blower motor, and by controlling the amount of fuel supplied to the boiler, high combustion
In a boiler in which combustion control is performed at three positions of low combustion and stop, a timer device for detecting an elapsed time and a damper for adjusting a ventilation amount from the blower between the blower and the boiler by partially closing at the time of ignition are provided. When the set time has elapsed since the ignition was performed with a part of the damper closed, a command was sent to the inverter to change the operating frequency to the low combustion frequency, and the elapsed time from the command output to the inverter A flow rate adjusting method using an inverter of a boiler, which outputs a command to open a damper when the detected elapsed time reaches a delay time T1. 4. An operating frequency output from the inverter to the blower motor by connecting an inverter in which a high combustion frequency and a low combustion frequency are set to the blower motor and sending a frequency command to the inverter. To change
The amount of air is adjusted by changing the rotation speed of the blower motor, and by controlling the amount of fuel supplied to the boiler, high combustion
In a boiler in which combustion control is performed at three positions of low combustion and stop, a timer device for detecting the elapsed time, a damper for adjusting a ventilation amount from the blower by partially closing between the blower and the boiler at the time of ignition, and a blower from the inverter A frequency detection device that detects the operating frequency sent to the motor is provided,
When a set time has elapsed since ignition was performed with a part of the damper closed, a command was sent to the inverter to change the operating frequency to a low combustion frequency, and the operating frequency detected by the frequency detector Outputting a command to open the opening of the damper when the pressure reaches the set value for switching. 5. The method according to claim 1, wherein a switching value for switching the combustion amount of the boiler from high combustion to low combustion and a switching value for switching from low combustion to high combustion. A method for adjusting the air flow rate by an inverter of a boiler, wherein each set value is set to a different value so as to be optimal. 6. A boiler for detecting an operating frequency sent from an inverter to a blower motor according to claim 1 or 4, the elapsed time from when a frequency switching command is output to the inverter. If the frequency detected by the frequency detector does not reach the set value for switching even if the elapsed time from outputting the frequency switch to the inverter reaches the set time, A method of adjusting air flow by a boiler inverter, which outputs an abnormal output.