JPS6048408A - Combustion control method for fluidized-bed combustion device - Google Patents

Abstract

PURPOSE:To enable a fluidized bed to correspond to fluctuation in a load, by a method wherein an amount of pulverized coal to be supplied is controlled according to a demanded sharp fluctuation in a load. CONSTITUTION:A desulfurizing agent and fine granular coal are fed in a fuel feed duct 7 from their respective storage tanks 5 and 9, they are conveyed by means of the air fed from a blower 17, and they are injected through a burner 15 into a bed to burn and desulfurize them therein. After pulverized coal is discharged from a pulverized coal storage tank 10, a feed amount thereof is precisely regulated by a feed amount precision regulator 13, the coal is burnt in a fluidized bed 2 through a duct 14 and a burner 16. In a fluctuation in a load, an amount of pulverized coal supplied is regulated by the precision regulator 13. When temperature in the bed is sharply reduced, the supply of fine granular coal and pulverized coal is brought to a stop, and when the fluidized bed is suddenly started and is sharply increased in temperature during operation, an amount of pulverized coal to be supplied is increased. Fine regulation of an amount of the pulverized coal to be supplied enables fine variation of the temperature of the fluidized bed.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a combustion control method for a fluidized bed twisting Jt'6 device σ, 1 which causes heat transfer in a fluidized bed, particularly for a steam turbine, etc. It is possible to cope with sudden load fluctuations of a machine that uses steam supplied from a boiler.

In view of the circumstances of the most L stone A11, various energy sources 1']
The trend for S is 1-7, but the use of nuclear power 2, S, and coal fl) is being reconsidered. The method of using one fluidized bed as one bale of coal combustion is attracting attention. .

This method enables intralayer desulfurization and removes nitrogen oxides from 11
1-Out 1 [While it has the advantage of low pollution due to less [ 64m? It has the disadvantage of not being able to cope with large tr load fluctuations. In other words, with conventional liquid fuel such as heavy oil17), even if the combustion is cut off, the coal supplied into the fluidized bed R-'t+4 hours continues to burn, and the temperature decreases within the bed at a rate of 1. ! J'it's dull. Therefore, it is necessary to take measures such as discharging the generated unnecessary steam to the 4 system 61, or injecting cooling 71t: to preserve the heat transfer tubes in the layer. With coal of a certain particle size or larger), the ignition rate and combustion rate are slow, so a rapid rise in the temperature in the bed cannot be expected. It is extremely difficult to rapidly change the Ifi internal temperature IM of 1illll -C' J,
It was not possible to respond to sudden load changes in machines that use steam. In addition, advance control of σ was required, such as reducing combustion and supplying coal in response to combustion delays.

The purpose of the present invention is to eliminate the drawbacks of the prior art described above, and to solve the problem of fluidized bed combustion apparatus 3. It is an object of the present invention to provide a combustion control method that can respond to the required rapid/1 load fluctuations.

In short, this invention focuses on the fact that pulverized coal (σ) combustion is rapidly transformed into DJF, and makes use of these 'l, '+' Ia to flow 7゛ and respond to load fluctuations. It was made to look like a monkey.

An embodiment of the present invention will be described below using the attached drawings.
Ru.

In FIG. 11, 1 is the main body of the fluidized bed.

Therefore, the air A and the more fluidized fluidized bed 2' are formed inside the main body 1, and the fluidized bed 2' is emitted from A'7A and i'1. l
B and superheater tubes 3 and other interlayer heat exchanger tubes are arranged, and 32'
The superheater 3 divides the steam supply pipe 4 and supplies the generated steam to the steam turbine (Figure 1) No. 1. A fuel supply system such as (Mai-1) is connected to this fluidized bed boiler.
This is a storage tank for storing a desulfurizing agent such as dolomite (dolomite), and rotary feeder 6f1. ．． It is connected to the main fuel supply tact 7 via a constant current supply device such as 8a. 91 "Fluidized bed Live combustion via 6b and 8b;
Connected to 1 and 7. ] 0 is a storage tank for storing pulverized coal (approximately 1.70% of pulverized coal) C10-tally feeder 12 and the product name;/-
[Pulverized coal supply 1 precision adjustment device such as feeder] Connected to the pulverized coal supply duct 14 through one port.

Among the smaller ducts, main fuel supply duct 7 (J style!
l! The pulverized coal supply duct 14 is connected to the pulverized coal burner 6 which is connected to the Ia
&, 'l-L. On the other hand, the two join at the other end and are connected to the blower 17.

I'11. In the device described above, the desulfurizing agent and the fine particles M flow into the fuel supply duct 7 from the storage tanks 5 and 9, respectively, are pneumatically transported by the air sent from the blower 17, and are transported to the burner 15.
It is ejected into the gravel layer to perform combustion and desulfurization. -After the pulverized coal is discharged from the pulverized coal storage tank]Or/n1, it is fed into the supply duct 14, which is precisely regulated. It passes through the burner 16 and burns in the fluidized bed z. Goko τ, fluidized bed 2
Within the layer? i1, "・degree is determined by the heat of combustion of this fine coal and pulverized coal, but usually (
,Masait.

The amount of charcoal supplied is kept almost constant, and if it is desired to vary the load, this is done by adjusting the pulverized coal supply claw σ in the precision adjustment device 13. Next, if it is desired to rapidly reduce the intralayer 'llA I'1 due to a failure of equipment that uses steam, etc., the supply of fine coal and pulverized coal σ1 is stopped. These 17 dampers 18 and 19 are left open, and the air for transporting the air is preferably used for cooling the bed (8 tons).Pulverized coal has a lower amount of air per weight than fine 1' and 7 coals. Due to the large contact area with the fuel supply, the 1'liA degree in the bed is t+'lt, and the powder 1.1+ is rapidly burned out, as shown in Figure 2, from the normal operating temperature T; , C16, 1≦stagnation, fuel supply stop poem P is allowed for such an allowable time, and within 3'1 capacity r2 i!,',
i・Down. After that, the remaining fine coal 7] burns (the temperature gradually decreases at ゛).In other words, it is clear from Fig.
Determine the time t2 required for the temperature T2 to drop; 1.
However, since the particle size of pulverized coal is extremely small, it is easy to fly out of the layer.
1 ((approx. 11M
Determine the mixing ratio. Next, the fluidized bed is suddenly changed to A11 motion ￥1-
If you want to sharply raise the temperature of the fluidized bed during operation, increase the amount of pulverized coal supplied.

Since it is possible to transport airflow with only 7: r wind, the drop in temperature within the bed due to this transport 71'7 air can be reduced.', 15 When starting a fluidized bed, only 1
Even if the temperature of the fluidized bed is rapidly increased by -I-
1. At this time, keep Gunpa 18 closed. Mata'1
:ζil! ':! By finely adjusting the supply amount of pulverized coal, it is possible to finely change the humidity of the fluidized bed.

At this time 1711. ) The number of particles per unit weight of pulverized coal is much larger than that of single granule coal, and the total particle surface area is also small. It has a large number of particles and can improve responsiveness and heat transfer coefficient. ■! 1; It has the effect of being able to directly respond to the required heat transfer load fluctuation Q/P.

In addition, 61 pulverized coal has a combustion delay of 1.1 degrees Celsius, so the amount of charcoal added is increased. Also, when reducing the number of injuries, the amount of combustion air, etc. is also reduced by 1.5 degrees at the same time. Combustion control can be increased or decreased by θη11.
'', I can write 4 times.

In carrying out this invention, the load response that relied on the auxiliary combustion burner '-9 is replaced by the eaves oil, and the operation that can respond to the load with a fluidized bed becomes +iJ' function. The fluidized fumigation/mu゛ε equipment, which was conventionally used for base load, has been adapted to P+'/1/1. For good burning, use the device 6゛ binding? [It is possible/made to be 1.

[Brief explanation of the drawing]

Figure 1 shows the system diagram of the combustion supply system (g), which does not show the -ν・' of this invention, and Figure 2 shows the relationship between the elapsed time and the decrease in the temperature in the bed by 1 degree. It is a line diagram. 1 ... Fluidized bed boiler body 2 ... Fluidized bed 5 ... Desulfurization agent storage tank / ... Main fuel supply duct ... Fine coal storage tank 10 ... Pulverized coal storage tank 13 --- Supply amount precision adjustment device 4 --- Pulverized coal supply duct 1.5. J, 6...Burner 17...Feeder

Claims (1)

[Claims] 1. 1 ill 1 granular coal and pulverized coal are supplied and combusted in a fluidized bed having an internal heat exchanger tube, and 1. Essential〉
1. A combustion control method for a fluidized bed combustion apparatus, comprising: 1) controlling the feed flea according to heat transfer load fluctuations;