JPH0722207U - Pulverized coal burner device - Google Patents

Abstract

(57) [Summary] [Purpose] An ignition torch is used to stabilize the combustion of a pulverized coal burner at low load. [Constitution] Burning heavy oil burner 3 and pulverized coal burner 4
And a igniting torch 5, which is a pulverized coal burner device for supplying light oil to the igniting torch 5.
An auxiliary combustion-necessary light oil amount setting device 20 is provided in the control valve 21 that can be opened and closed and an intermediate opening can be set in a light oil supply pipe 8 that connects the auxiliary combustion-necessary light oil amount setting device 20 and the ignition torch 5.
Is provided, an intermediate opening degree command 23 is issued to the control valve 21 when the ignition torch 5 is ignited, and a full-open instruction 24 is issued to the control valve 21 when the pulverized coal burner 4 is under a low load. At times other than time, the control valve 21 is instructed to close 25
A flow rate controller 22 that outputs

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a pulverized coal burner device.

[0002]

[Prior art]

 As shown in FIG. 3, a pulverized coal burner device provided in a furnace such as a pulverized coal burning boiler is configured so that one burner port 2 of the furnace 1 surrounds the heavy oil burner 3 for burning and the heavy oil burner 3. The pulverized coal burner 4 thus formed and one ignition torch 5 are provided, and a secondary air duct 6 and an air register vane 7 are provided to the outside of the pulverized coal burner 4. Air is supplied.

A light oil supply device 9 is connected to the ignition torch 5 via a light oil supply pipe 8. The light oil supply device 9 includes a light oil tank 10, a light oil pump 11, and an outlet of the light oil pump 11. And a light oil tank 10 are connected to each other, a flow control valve 13 provided on the return pipe 12, and a light oil supply pipe 8 for measuring the flow rate of light oil flowing through the light oil supply pipe 8. An ignition required light oil amount setting device 14 for controlling the amount of return to the light oil tank 10 by the flow rate control valve 13 so that the flow rate becomes a constant amount required for ignition by the ignition torch 5 (ignition required light oil amount). I have it.

Further, an opening / closing valve 15 is arranged in the light oil supply pipe 8, and an opening / closing controller 19 for issuing an opening command 17 and a closing command 18 based on a control command 16 of the furnace is connected to the opening / closing valve 15. ing. Reference numeral 5a in the drawing denotes air for supplying to the ignition torch 5 to atomize the light oil and for supplying to the outlet of the on-off valve 15 to purge the light oil supply pipe 8 and the ignition torch 5.

When the pulverized coal burner 4 is started, first, the open / close valve 15 is opened by the open command 17 from the open / close controller 19 to burn the ignition torch 5, and the heavy oil burner 3 injects heavy oil. By doing so, the heavy oil burner 3 is ignited, and then the heavy oil burner 3 burns for a required time to raise the temperature in the furnace. At this time, as shown in FIG. 4, the ignition torch 5 is supplied with a constant amount of light oil required for ignition set by the light oil required for ignition setting device 14, and the ignition time at this time is usually about 1 minute. When completed, the opening / closing valve 15 is closed and the ignition torch 5 is extinguished by the closing command 18 from the opening / closing controller 19.

When the temperature inside the furnace reaches a predetermined temperature due to the combustion of the heavy oil burner 3, the combustion of the heavy oil burner 3 is stopped, and at the same time, the pulverized coal burner 4 injects the pulverized coal while burning the ignition torch 5. The pulverized coal burner 4 is ignited, and thereafter, the supply amount of pulverized coal is gradually increased to burn it at a predetermined load.

[0007]

[Problems to be solved by the device]

 In recent years, in pulverized coal-fired boilers, etc., the required load may change significantly due to changes in the power demand over time, and as a result, there are often demands to operate in a state in which the load is significantly narrowed down. Is beginning to do.

However, in the above-mentioned conventional pulverized coal burner apparatus, when the load reduction of the pulverized coal burner 4 is required as shown in FIG. 5, even if the supply amount of the pulverized coal from the pulverized coal mill (not shown) is reduced. Since the flow rate of primary air required to convey pulverized coal cannot be reduced below a certain amount, it becomes an air rich state and creates a combustion instability region. The low load operation area (Turn Down) of the pulverized coal burner 4 cannot be expanded to within the unstable region, so that the control range of the pulverized coal burning boiler and the like was narrowed.

The present invention was made in order to solve the problems in the above-mentioned conventional method, and by using the ignition torch to assist the combustion of the pulverized coal burner at low load, stable combustion at low load is possible. It is an object of the present invention to provide a pulverized coal burner device capable of expanding the low load operable area.

[0010]

[MEANS FOR SOLVING THE PROBLEMS] The present invention is a pulverized coal burner device comprising a heavy oil burner for heating, a pulverized coal burner, and an ignition torch, which is a gas oil supply device for supplying diesel oil to the ignition torch. A light oil amount setting device required for auxiliary combustion is installed in the fuel oil supply pipe connecting the light oil amount setting device required for auxiliary combustion and the ignition torch, and a control valve capable of opening and closing and setting an intermediate opening degree is provided in the light oil supply pipe. A flow rate that issues an intermediate opening command to the control valve when the torch is ignited, a fully open command to the control valve when the pulverized coal burner is at a low load, and a close command to the control valve at a time other than during the ignition and the low load. The present invention relates to a pulverized coal burner device characterized by comprising a controller.

[0011]

[Action]

 In the present invention, at the time of ignition of the fuel oil burner for burning and the ignition of the pulverized coal burner, the flow control valve is set to the intermediate opening by the intermediate opening command from the flow controller, and the amount of light oil required for ignition to the ignition burner is required. Is supplied to ignite, and when the pulverized coal burner is under a low load, the flow control valve is fully opened by a full-open command from the flow controller, and the auxiliary combustion-necessary diesel oil set by the auxiliary combustion-necessary diesel fuel amount setting device is set in the ignition torch. By supplying the amount, the combustion of the ignition burner assists the combustion of the pulverized coal burner.

[0012]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In FIG. 1, the same parts as those in FIG. 3 are designated by the same reference numerals and detailed description thereof will be omitted, and only the characteristic parts of the present invention will be described. .

As shown in FIG. 1, a gas oil supply device 9 for supplying gas oil to the ignition torch 5 is provided with a gas oil amount setting device 20 requiring auxiliary combustion. The auxiliary combustion required gas oil amount setting device 20 measures the flow rate of the gas oil flowing through the gas oil supply pipe 8, and when the flow rate is a low load of the pulverized coal burner 4, it is a constant necessary for supporting the pulverized coal burner 4 for stable combustion. The amount of return to the light oil tank 10 by the flow rate control valve 13 is controlled so that the amount (the amount of light oil required for auxiliary combustion) is adjusted.

A control valve 21 capable of controlling opening and closing and an intermediate opening position is provided in a light oil supply pipe 8 for supplying light oil from a light oil supply device 9 to the ignition torch 5, and the control valve 21 controls a flow rate. 22 is connected and arranged.

The flow rate controller 22 outputs an intermediate opening degree command 23 at the time of ignition using the ignition torch 5 based on the control command 16 of the furnace 1 such as the pulverized coal burning boiler to operate the pulverized coal burner 4 with a low load. The fully open command 24 is issued when the load is low, and the close command 25 is issued when the ignition is not performed or when the load is low.

Next, the operation of the above embodiment will be described.

When the burning heavy oil burner 3 is ignited and the pulverized coal burner 4 is ignited, the control valve 21 is adjusted to the intermediate opening state by the intermediate opening command 23 from the flow rate controller 22. As shown in FIG. 2, the ignition torch 5 is ignited by supplying an appropriate amount of light oil required for ignition in the ignition torch 5 to the ignition torch 5.

Further, when the pulverized coal burner 4 has a low load, it is suitable to fully open the control valve 21 in response to a full-open command 24 from the flow rate controller 22 to assist the pulverized coal burner 4 as shown in FIG. The pulverized coal burner 4 is assisted by supplying the amount of auxiliary gas required for combustion (the amount set by the auxiliary combustion required amount of light oil amount setting device 20) to the ignition torch 5.

As described above, when the pulverized coal burner 4 has a low load, it is possible to supply the ignition torch 5 with an auxiliary combustion-requiring light oil amount having a flow rate larger than the ignition-requiring light oil amount to assist the pulverized coal burner 4. Therefore, as shown by the broken line A in FIG. 5, it becomes possible to perform stable combustion even at a low load that enters the unstable combustion region, and thus the pulverized coal burner 4 can operate in a low load range. Can be greatly expanded.

The present invention is not limited to the above-described embodiment, and the control valve is opened and closed and the intermediate opening is switched. However, the light oil flow rate is set to the load during low load of the pulverized coal burner. Needless to say, it may be adjusted according to the above, and various changes may be made without departing from the scope of the present invention.

[0022]

[Effect of device]

 According to the pulverized coal burner device of the present invention, when the load of the pulverized coal burner is low, it is possible to supply the amount of light oil required for auxiliary combustion to the ignition torch to assist the combustion of the pulverized coal burner. Can be stabilized, and the low load operation area of the pulverized coal burner can be greatly expanded, and an excellent effect can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional side view showing an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a flow rate controller command and a light oil supply amount to an ignition burner in the present invention.

FIG. 3 is a cut side view showing an example of a conventional pulverized coal burner device.

FIG. 4 is a diagram showing a relationship between an opening / closing controller command and a light oil supply amount to an ignition burner in a conventional pulverized coal burner device.

FIG. 5 is a diagram showing an example of a pulverized coal burner load, showing a relationship with an unstable combustion region.

[Explanation of symbols]

 3 Burning heavy oil burner 4 Pulverized coal burner 5 Ignition torch 8 Light oil supply pipe 9 Light oil supply device 20 Light oil amount setting device for auxiliary combustion required 21 Control valve 22 Flow control device 23 Intermediate opening command 24 Full opening command 25 Close command

Claims (1)

[Scope of utility model registration request] 1. A pulverized coal burner device comprising a heavy oil burner for burning, a pulverized coal burner, and an ignition torch,
A light oil supply device for supplying light oil to the ignition torch is provided with an auxiliary combustion-necessary light oil amount setting device, and a light oil supply pipe that connects the auxiliary combustion-necessary light oil amount setting device and the ignition torch can be opened and closed and an intermediate opening can be set. A control valve is provided, an intermediate opening command is issued to the control valve at the time of ignition by the ignition torch, and a full open command is issued to the control valve when the pulverized coal burner has a low load, except when the ignition and the low load are applied. A pulverized coal burner device comprising a flow rate controller which sometimes issues a closing command to the control valve.