JPH09210355A - Combustion control system for coal boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely and easily ignite a petroleum burner and to automate fuel switching from coal to petroleum by judging the malfunction under condition control using a computer and igniting the burner according to an electric signal from a sensor for sensing that a trouble occurs in a coal fuel system. SOLUTION: The combustion control system for a coal boiler comprises a coal supply unit 5 for supplying pulverized coal powder to the boiler 1 and a petroleum supply unit 2 for supplying fine petroleum particles. The system further comprises a sensor for sensing a malfunction of a coal fuel system. As the sensor, a sensor for sending a bridge of a coal banker 11, a sensor for sensing a malfunction of a coal pulverizer 13, a sensor for sensing a malfunction of a coal supply unit 12, or a sensor for sensing a bag filter differential pressure is used. A control circuit includes a display unit for displaying a malfunction and a computer for igniting the petroleum system according to the electric signal from the sensor obtained by closing the contact by mechanical operation or the electric signal fed from the sensor for measuring the temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coal boiler combustion control system for igniting an oil burner when a coal fuel system trouble occurs in a coal boiler and for switching from coal to oil as fuel.

[0002]

2. Description of the Related Art Normally, a coal boiler burns coal exclusively, but if an abnormality occurs in the coal fuel system, such as a delay in the supply of coal to the coal boiler, it is necessary to continue operating the coal boiler. The operation to switch to the burner is required.

Conventionally, when an abnormality occurs in the coal fuel system, the operator confirms the abnormality message and then judges whether or not the oil burner needs to be ignited, and if so, the oil burner is ignited. Preparatory operation is performed, and if completed, command operation of ignition signal is performed.

Further, when it is judged that fuel switching is necessary depending on the degree of trouble, or when the coal fuel system is intentionally stopped, the fuel is switched from coal to petroleum.

However, since most of these operations are performed by the operator, a skilled operator must make judgments and operations, and a large number of operators are required, which requires a long switching time.

Further, when a trouble occurs in the coal fuel system, the control system is greatly disturbed and it is difficult to make a calm decision, so that even a skilled operator is likely to make an erroneous operation, and there is a risk of developing a big trouble. Along with
The damage when the boiler stops is great.

[0007]

Even in the above situation, the present invention does not require a skilled operator in particular, and safely and easily ignites the oil burner and automatically switches the fuel from coal to oil. An object of the present invention is to provide a coal boiler combustion control system that can be performed in a specific manner.

[0008]

A coal boiler combustion control system according to the present invention is provided with a sensor capable of detecting occurrence of a trouble in a coal fuel system in a coal boiler equipped with a coal burner and an oil burner. It is characterized by the fact that it is possible to continuously operate by determining the abnormality and taking measures to ignite the oil burner by controlling the condition using a computer by an electric signal from the computer. To be done.

The present invention constantly monitors for abnormalities in the coal fuel system,
When an abnormality occurs, one oil burner is automatically ignited immediately.

Further, when fuel switching is required, by issuing a command, the petroleum burner is automatically ignited sequentially and the amount of coal is reduced, and the control of main steam pressure is automatically switched from coal control to petroleum control. It also automatically shuts down the machine, extinguishes the propane burner that is required when the oil burner is ignited, and cools the pulverized coal machine.

Therefore, the operator can automatically ignite the petroleum burner and switch the fuel only by a confirmation operation. Furthermore, even if the first oil burner fails to ignite, it is possible to ignite a burner with a different corner, and it is possible to stop the sequence in the middle of fuel switching, switch it to manual, or restart it. It can be used in any situation.

[0012]

1 shows an example of a coal boiler combustion apparatus in which a coal boiler combustion control system of the present invention is used.

The coal boiler combustion apparatus comprises a coal supply device 5 for supplying fine coal powder to the coal boiler 1 and an oil supply device 2 for supplying fine oil particles to the coal boiler 1. The coal supply device 5 includes a coal bunker 11, a coal feeder 12 provided below the coal bunker 11, a pulverized coal machine 13 connected to the coal bunker 12, and a pulverized coal machine 13 which is cooled to the pulverized coal machine 13. A primary air fan 14 capable of supplying air and hot air;
When the coal fuel system is used, pulverized coal is supplied from the pulverized coal machine 13 to the coal boiler 1 at all times.

Further, a sensor for detecting an abnormality in the coal fuel system is provided. Examples of the sensor include a sensor for detecting coal bunker bridge, a sensor for detecting abnormality of pulverized coal machine, a sensor for detecting abnormality of coal feeder, a sensor for detecting differential pressure of bag filter, and the like. By the electrical signal from the sensor obtained by closing the contacts by these mechanical operations and the electrical signal sent from the sensor that measures temperature,
There is provided a control circuit including a display for indicating an abnormality and a computer for igniting a petroleum system.

The petroleum supply device 2 includes an oil tank 21.
The spray pump 22 and the heater 23 are provided and are operated when an abnormality occurs in the coal fuel system or when fuel switching is necessary. A water supply pipe 3 and a steam pipe 4 are arranged in the coal boiler 1.

The sequence of the coal boiler combustion control system of the present invention is shown below.

FIG. 2 shows an outline of a sequence when one oil burner is ignited. After the start, in step (#) 1, it is monitored whether or not an abnormality has occurred in the coal fuel system, and if abnormal, the process proceeds to step (#) 2. Examples of monitoring items in step (#) 1 include coal bunker bridge, pulverized coal machine abnormality, coal feeder abnormality, bag filter differential pressure, and the like. In step (#) 2, preparation for ignition of the oil burner is performed, and in step (#) 3, one oil burner is ignited. Examples of the preparation items include setting of oil pressure and setting of atomized steam. If the ignition of the oil burner is defective, another oil burner other than this is ignited in step (#) 4. When ignition is completed, it ends.

FIG. 3 shows an outline of a sequence at the time of switching fuel.

After the ignition of one oil burner, the oil flow rate is increased in step (#) 3. When switching plans, in step (#) 1, the oil burner ignition preparation is performed. Items to be prepared include setting the pressure in the furnace, setting the main steam pressure, setting the oil pressure, and setting the spray steam. Next, in step (#) 2, one oil burner is ignited, and then the oil flow rate is increased in step (#) 3.

Next, in step (#) 4, the oil burner 2
After igniting the third one, the main steam pressure control is switched (step (#) 5), the coal feeding flow rate is reduced (step (#) 6), and the third oil burner is ignited (step (#) 7). . Then stop the coal feeder (step (#)
8), ignite the fourth oil burner (step (#)
9) Then, the propane burner is extinguished and the pulverized coal machine is cooled (step (#) 10).

[0021]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto.

(Embodiment 1) In the coal boiler having the coal boiler combustion control system shown in FIG. 2, a coal feeder inlet bridge sensor was operated during coal combustion to cause a failure of the coal fuel system.

In this case, first, the oil pressure regulator was switched from manual control to automatic control, and the pressure setting was set to 5 kg / cm ² . Next, it was confirmed that the pressure setting was within the specified value while the spray vapor pressure controller was in the automatic control state, and one propane burner was ignited. After confirming ignition, one oil burner was ignited.

All the above operations were performed automatically, but there was no disturbance in the control system.

(Embodiment 2) In the coal boiler having the coal boiler combustion control system shown in FIG. 2, the first oil burner was intentionally made unable to ignite, and the same failure as in Embodiment 1 occurred.

In this case, the ignition command for the first oil burner was issued in the same manner as in Example 1, but since it did not ignite, a message of ignition failure was issued, and then the second propane burner and the oil burner were ignited. did.

The first oil burner causes the burner to complete the fire extinguishing by issuing a reset command for the ignition failure alarm after the second burner completes the ignition and issuing a fire extinguishing command after the completion of the reset, and the first propane is burned. The burner also extinguished.

All the above operations were performed automatically, but there was no disturbance in the control system.

(Embodiment 3) When the fuel switching sequence is activated during coal burning, first, the set value of the furnace pressure is lowered by 15 mmAq, the oil pressure controller is switched from manual control to automatic control, and the pressure setting is changed. It was set to 5 kg / cm ² , the spray vapor pressure controller was automatically controlled, and it was confirmed that the pressure setting was within the specified value, and the first propane and petroleum burner were ignited.

After the completion of ignition, the oil flow rate was increased until the oil pressure reached 8 kg / cm ² , and the second propane and oil burner were ignited. Next, in order to switch the main steam pressure control, after switching the main steam pressure controller from automatic control to manual control and switching the coal feed rate controller from cascade control to automatic control,
The main steam pressure control is changed from coal control to oil control by matching the upper signal of the oil flow controller, switching the oil flow controller from automatic control to cascade control, and switching the main steam pressure controller from manual control to automatic control. became.

Next, the amount of petroleum was increased by decreasing the amount of coal supplied, and when the oil pressure reached 6.5 kg / cm ² , the third propane and petroleum burner were ignited. Further, the coal feed amount was reduced to 2.5 tons / hour, the coal feed machine was stopped, and the fourth propane and petroleum burner were ignited.
Finally, all four propane burners were extinguished, the hot air of the pulverized coal machine was squeezed to a cooled state, and the fuel switching sequence was completed.

All the above operations were performed automatically, but the control system was not disturbed.

[0033]

As described above, according to the present invention, even if a trouble occurs in the coal fuel system, the petroleum burner is automatically ignited promptly to prevent the boiler from being stopped due to the cutoff of all fuels, and it is not necessary for a skilled operator. It is possible to switch fuel from coal to oil smoothly without disturbing the control system.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a combustion apparatus using a coal boiler combustion control system of the present invention.

FIG. 2 is a diagram showing an outline of a sequence in the case of igniting one oil burner in the coal boiler combustion control system of the present invention.

FIG. 3 is a diagram showing an outline of a fuel switching sequence in the coal boiler combustion control system of the present invention.

[Explanation of symbols]

 1 Coal Boiler 2 Oil Supply Device 3 Water Supply Pipe 4 Steam Pipe 11 Coal Bunker 12 Coal Feeder 13 Pulverized Coal Machine 14 Primary Air Fan 21 Oil Tank 22 Spray Pump 23 Heater

Claims (2)

[Claims] 1. A coal boiler equipped with a coal burner and a petroleum burner is provided with a sensor capable of detecting the occurrence of a trouble in a coal fuel system, and an electrical signal from the sensor is provided to cause an abnormality in condition control using a computer. A coal-boiler combustion control system that can be continuously operated by determining the above and taking measures to ignite the oil burner. 2. The control system according to claim 1, wherein the control system can be used in the coal boiler even at the time of switching due to a planned stop of the coal fuel system.