JP3310130B2 - Boiler ignition method - 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 igniting a boiler which performs three-position control such as high combustion, low combustion, and stop, and more particularly to a method for igniting a boiler in which the rotation speed of a blower is controlled by a rotation speed control device. It is.

[0002]

2. Description of the Related Art A method of controlling the rotation speed of a blower by a rotation speed control device and controlling the amount of air sent to a boiler has advantages such as power saving and downsizing of the blower, and is widely used in boilers. However, this method has a drawback that when the rotation speed of the blower is reduced, the air volume and pressure are reduced, and the performance of the blower tends to enter the surging region. Therefore, if an attempt is made to ignite with a low-combustion air volume having a low rotation speed, problems such as a loud ignition sound and oscillating combustion occur, and the stability of combustion is reduced.

As a method for igniting this type of boiler, there is one disclosed in Japanese Patent Application Laid-Open No. H05-10522. In this method, the rotation speed of the blower between the ignition after the prepurge and the first low combustion following this is set to the high combustion air flow rate, and the opening of the damper is positioned at the low combustion air flow position.

[0004]

According to the above-mentioned ignition method, at the time of ignition, since the rotation speed is set to a high combustion air volume by an inverter or the like, the ignition does not enter the surging region and the ignition and combustion are stabilized. Power is not reduced accordingly. In particular, if the frequency of starting and stopping the boiler increases, the ignition operation becomes frequent, and the power reduction rate of the blower decreases.

The present invention has been made in view of the above points, and as described above, during the ignition after prepurge and the subsequent low combustion, the rotation speed of the blower is set to a high combustion air flow rate, and the damper is set to a low combustion rate. An object of the present invention is to provide a method for igniting a boiler capable of improving the power reduction rate of a blower as compared with an ignition method for setting a use air flow position and performing stable ignition.

[0006]

According to the present invention, there is provided a method for igniting a boiler, wherein a rotation speed of a blower is controlled by a rotation speed control device to control an amount of air sent to a boiler combustion chamber. The rotation speed is any rotation speed not less than the low combustion rotation speed and not more than the high combustion rotation speed. When the ignition device is activated, the rotation speed of the blower is reduced to a predetermined rotation speed lower than the high combustion rotation speed. After confirming that the fuel solenoid valve has opened and ignited, when the ignition device is turned off, the rotation speed of the blower is reduced to the low combustion rotation speed.

In addition, air flow control by a damper is also used at the time of ignition, the damper is set to a fully open position during prepurge, and after completion of prepurge, the damper is set to an open position smaller than the full open position, and the fuel solenoid valve is opened to ignite. After confirming that the ignition device is turned off, the opening degree of the damper is kept as it is.

[0008]

According to the method for igniting a boiler of the present invention, as described above, during the pre-purge, the rotation speed of the blower is set to an arbitrary rotation speed not lower than the low combustion rotation speed and not higher than the high combustion rotation speed. The rotation speed of the blower is set to the ignition rotation speed at a predetermined rotation speed lower than the high combustion rotation speed, and after confirming that the fuel solenoid valve is open and ignited, when the ignition device is turned off, the rotation speed of the blower is reduced to the low combustion rotation speed. Since the speed is reduced, the blower does not enter the surging area at the time of ignition, and ignition and combustion are stabilized. Also, between the ignition after prepurge and the first low combustion following, the rotation speed of the blower is set to the high combustion air flow rate, and the power reduction rate of the blower is improved compared to the conventional ignition method where the damper is set to the low combustion air flow position Can be done.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for igniting a boiler according to the present invention will be described with reference to the drawings. FIG. 6 is a diagram showing a configuration of a boiler system that implements the ignition method of the present invention. As shown
The boiler system includes a boiler 1, a casing 2, a blower 3, a rotation speed control device 4, a control unit 5, a pump 6, a low combustion oil solenoid valve 7, a high combustion oil solenoid valve 8, and a burner 9.

In the boiler system having the above-described configuration, the rotation speed of the blower 3 is controlled by the control of the rotation speed control device 4, and the wind from the blower 3 passes through the casing 2 and the boiler 1
Supplied within. Fuel is supplied to the burner 9 by the pump 6 through the low combustion oil solenoid valve 7 and the high combustion oil solenoid valve 8, and the fuel injected from the burner 9 is ignited by an ignition device (not shown), burns, and burns. A flame F is formed in the combustion chamber 10 of the first embodiment.

Embodiment 1 FIG. 1 is a timing chart of the rotation speed of a blower according to Embodiment 1 for carrying out the ignition method of the present invention. In the figure, the vertical axis indicates the fan rotation speed V, and the horizontal axis indicates time t. In the boiler system having the above configuration, air is sent from the blower 3 before the combustion operation, and
It is necessary to remove the combustion exhaust gas within 0, that is, perform pre-purge. Therefore, in response to the start signal S from the control unit 5, the rotation speed control device 4 starts the blower 3 and enters the prepurge.

During the pre-purge, the rotation speed control device 4 sets the rotation speed of the blower 3 to the low combustion rotation speed V _L. After the completion of the pre-purge, the ignition device is activated at time t1 and the rotation speed control device 4 the rotational speed and rotational speed V _F for igniting not lead to oscillatory combustion during ignition, after confirming that the low combustion oil electromagnetic valve 7 is ignited at low fire opened at time t2, at time t3 when the igniter is turned off at the same time The rotation speed control device 4 sets the rotation speed of the blower 3 to the low combustion rotation speed _VL . Then the rotational speed control device 4 in response to the combustion signal from the control unit 5 when the rotational speed V of the blower 3 of the high combustion (time t4) is a rotational speed V _H for high combustion, at low combustion (time t5 ) Is the low combustion rotation speed _VL .

[Embodiment 2] FIG. 2 is a timing chart of the rotation speed of a blower according to an embodiment 2 for implementing the ignition method of the present invention. In the figure, the vertical axis indicates the fan rotation speed V, and the horizontal axis indicates time t. In the present embodiment, the rotation speed of the blower 3 is set to the low combustion rotation speed _VL during the pre-purge and at the time of ignition (time t2).
The was also the ignition rotation speed V _F of the reference), i.e. the first rotation speed of the blower 3 to the time of ignition and ignition rotation speed V _F from the pre-purge, low combustion oil electromagnetic valve 7 is ignited at low fire open Is confirmed, the rotation speed of the blower 3 is reduced to the low combustion rotation speed _VL . Then the rotational speed control device 4 when the rotational speed V of the blower 3 of the high combustion (see time t4) is a rotational speed V _H for high combustion in accordance with the combustion signal, when the low fire (see time t5) is low The rotation speed for combustion is _VL .

[Embodiment 3] FIG. 3 is a timing chart of the rotation speed of a blower and the opening degree of a damper according to a third embodiment for implementing the ignition method of the present invention. In the figure, the upper vertical axis represents the fan rotation speed V, the horizontal axis represents time t, the lower vertical axis represents the damper opening O, and the horizontal axis represents time t. This embodiment is Embodiment 1.
Fig. 8 shows a case where air volume control by a damper is used together. The rotation speed control device 4 starts the blower 3 in response to the start signal S, and changes the rotation speed V of the blower 3 to the low combustion rotation speed V during the prepurge.
Is _L, the damper opening degree O and the high combustion airflow position O _H.

[0015] After the pre-purge completion, the damper opening O is in a low combustion airflow position O _L, the ignition device at time t1 is actuated speed control device 4 at the same time as the rotation speed V _F for igniting the rotational speed of the blower 3, after confirming that the low combustion oil solenoid valve 7 at the time t2 is ignited at low fire open, the damper opening O at the same time as the ignition system is turned off at time t3, the rotation speed control device while the low combustion airflow position O _L Reference numeral 4 designates the rotation speed V of the blower 3 as a low combustion rotation speed _VL . Thereafter, in response to the combustion signal, the rotation speed control device 4 controls the rotation speed V of the blower 3 to two positions of a high combustion rotation speed _VH and a low combustion rotation speed _VL , and the damper moves to the high combustion airflow position O. It will be controlled by two position _H and a low combustion airflow position O _L.

However, in this case, the opening degree of the damper is not controlled by the conventional damper 11 as shown in FIG. 4, but is controlled by the damper 11 as shown in FIG. That is, the air volume control by the damper 11 performed in the third embodiment is performed as shown in FIG.
The damper 11 is fully opened at a high combustion airflow position O _H as shown in, for low combustion airflow position O _L is larger than the conventional opening, the fully open degree position smaller opening position. Accordingly, since reducing the loss due to low combustion airflow position O _L even damper 11, there is no problem in the power reduction of the blower.

In the third embodiment, the case where the air volume control by the damper is used in combination with the first embodiment is shown. However, the present invention is not limited to this, and the air volume control by the damper may be used in the second embodiment. . Again, at the same time the damper opening when ignition device expires rotation speed control device 4 while the low combustion airflow position O _L to the rotational speed V of the blower 3 and the low combustion speed V _L. Thereafter, in response to the combustion signal, the rotation speed control device 4 changes the rotation speed V of the blower 3 to the high combustion rotation speed V.
_H and the low-combustion rotation speed _VL to control the damper 1
1 2 high combustion airflow position O _H and a low combustion airflow position O _L
It will be controlled by position.

Further, the rotational speed of the blower 3 in Example 1, the rotational speed V _L for low combustion in pre-purge, although the rotational speed V _F for ignition in the second embodiment, the blower 3 in prepurge
The rotation speed V is not limited thereto and may even high combustion speed V _H, or a short arbitrary rotation speed and less high combustion speed V _H at low combustion speed V _L or more .

[0019]

As described above, according to the present invention, the following excellent effects can be obtained. (1) The stability of combustion after ignition is improved by setting the rotation speed of the blower at the time of ignition to an ignition rotation speed that does not reach oscillating combustion.

(2) Since the rotation speed of the blower is controlled at an arbitrary rotation speed between low combustion, high combustion, and low combustion and high combustion, the rotation speed of the blower is reduced as compared with the conventional flow rate control using a damper. Power consumption can be reduced.

[Brief description of the drawings]

FIG. 1 is a timing chart of a fan rotation speed according to a first embodiment for implementing an ignition method of the present invention.

FIG. 2 is a timing chart of a fan rotation speed according to a second embodiment for implementing the ignition method of the present invention.

FIG. 3 is a timing chart of a fan rotation speed and a damper opening according to a third embodiment for implementing the ignition method of the present invention.

FIG. 4 is a diagram showing a damper opening in conventional damper air volume control.

FIG. 5 is a diagram showing a damper opening in damper air volume control used in conjunction with Embodiment 3 of the present invention.

FIG. 6 is a diagram showing a configuration of a boiler system that implements the ignition method of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 boiler 2 casing 3 blower 4 rotation speed control device 5 control unit 6 pump 7 low combustion oil solenoid valve 8 high combustion oil solenoid valve 9 burner 10 combustion chamber 11 damper

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-55614 (JP, A) JP-A-5-10522 (JP, A) JP-A-60-205121 (JP, A) (58) Investigation Field (Int.Cl. ⁷ , DB name) F23N 3/08 F23N 5/18 F23N 5/20

Claims (2)

(57) [Claims] 1. A method for igniting a boiler, wherein a rotation speed of a blower is controlled by a rotation speed control device to control a flow rate of air blown into a boiler combustion chamber. A rotation speed equal to or higher than the rotation speed and equal to or lower than the high combustion rotation speed; when the ignition device is activated, the rotation speed of the blower is set to an ignition rotation speed having a predetermined rotation speed lower than the high combustion rotation speed; A method for igniting a boiler, comprising, after confirming that a valve has opened and ignited, when the ignition device is turned off, the rotational speed of the blower is reduced to the low combustion rotational speed. 2. The air flow control by a damper at the time of ignition is also used, the damper is set to a fully open position during the prepurge, and after the prepurge is completed, the damper is set to an open position smaller than the full open position, and the fuel solenoid valve is opened. 2. The method for igniting a boiler according to claim 1, wherein, after confirming that the ignition has occurred, when the ignition device is turned off, the damper opening is kept as it is.