JPS59164823A - Moving bed drum type coal burning boiler - Google Patents

Abstract

PURPOSE:To suppress the fluctuation of steam pressure even if quick and substantial change in flow rate of steam occurs, by providing a branch air feed pipe, combustion temperature measuring means, controllers for controlling the openings of compartment dampers and means for measuring the oxygen content of combustion gas. CONSTITUTION:Based on a sum signal (f) obtained from the amount of a steam pressure deviated from a set pressure value and a steam flow rate, the amount of air supply by a air supply fan 30 provided in the branch pipe 32 is adjusted. Then the opening of a damper 33 is controlled to adjust the amount of air that will be blown from below a moving bed 34. A combustion temperature pattern of each of the compartments 41 is formed by the sum signal (f), and the openings of the compartment dampers 41a are controlled in such a way that the combustion temperature signals by the combustion temperature measuring means 40 may be in conformity with the combustion temperature patterns of the compartments 41. Further the amount of coal to be fed in conformity with the amount of that air is assessed by the value obtained by an oxygen content converter 38 to correct the sum signal (f).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a moving bed drum type coal-fired boiler.

Figure 1 shows a conventional moving bed drum type coal-fired boiler. This coal-fired gas pump supplies water with water pump 1 and water supply control valve 2.
Is it drum-shaped? The steam is supplied to the boiler 3 and heated in the evaporation section 4 to generate steam, and the steam is supplied to the superheating section 5. The steam is supplied to predetermined equipment via the steam flow control valve 6.

In this coal-fired boiler, when the steam flow control valve 6 is opened or closed in response to a steam flow rate request, the steam flow rate increases or decreases, and at the same time, the steam pressure fluctuates.

Therefore, in order to prevent this pressure fluctuation, control is performed as follows. That is, when the steam pressure fluctuates, the pressure transducer 7
This is detected, and a deviation signal between this detection signal and the pressure setting value S from the pressure setting device 8 is input to the controller 9.

On the other hand, the steam flow rate is detected by the converter 10 and the signal is adjusted by the controller 11. The output of the controller 1 is added to the output of the controller 9 and inputted to the coal feeder 12 and the air supply device 13 as an operation signal.

The coal feeding device 12 changes the speed of the movable bed 14, adjusts the amount of coal 19 spread, and adjusts the amount of coal fed in response to this operation signal. Coal 19 is spread over one surface of moving bed 14 by a spreader (not shown). The above air supply system Wj
us adjusts the air necessary for combustion according to the operation signal. The air is branched into air 16 and auxiliary combustion air 17 that are blown up from below the movable bed 14 via dunnage pipes 15 . . . . In this way, by supplying coal and air 16°17, the amount of combustion changes, the amount of heat received by the evaporator 4 changes, and the drum-shaped? The pressure of the blower 3 is controlled.

Incidentally, the ash 18 burned on the moving bed 14 is sent to an ash processing section (not shown) by the movement of the moving bed 14.

However, in this moving-bed drum-type coal-fired deira, the coal feeding distribution pattern in the moving direction of the moving bed 14 changes when the size ratio of the supplied coal particles, the rotation speed of the spreader, etc. change.

When the dispersion pattern fluctuates, over the entire surface of the moving bed 14, there will be some air vents and some buried fire areas, resulting in uneven combustion, and an excessive amount of air will be needed to burn the whole area.
It is necessary to supply 6. .

If excessive air 16 is supplied, the amount of combustion cannot be increased or decreased even if the amount of air 16 is increased or decreased, making it difficult to control the amount of combustion. Therefore, when increasing combustion, the supplied coal must be burned.

Moreover, when the amount decreases, it is necessary to wait until the combustion of coal on the moving bed 14 becomes smaller.

As a result, it is difficult to respond accurately to rapid changes in the steam flow rate, and the pressure in the steamer is subject to large fluctuations.
There is a problem that interferes with driving.

The present invention has been made in view of the above circumstances, and its purpose is to
It is an object of the present invention to provide a moving bed drum-type coal-fired galley that can cope well with this and can suppress fluctuations in steam pressure.

That is, the present invention provides a branch air pipe having a plurality of compartment dampers provided below the moving floor and along the moving direction thereof, and above the moving floor 3 corresponding to each compartment damper. -One,,-! The casting machine includes a plurality of combustion temperature measuring means provided, a controller that outputs an opening control signal to each corresponding compartment Dan/Mother based on the detection signal of the measuring means, and The present invention is characterized by comprising a measuring means for measuring the content rate, and a controller for outputting a coal feeding amount control signal to a moving bed coal feeding device based on a detection signal of the measuring means.

Hereinafter, the present invention will be explained using a moving bed drum type coal-fired system as shown in FIG. This will be explained with reference to Ira.

The drawing shows the air and coal feed control system. This control system is
Superheating section 22 and steam flow control valve 23 provided in steam flow path 2
A pressure transducer 24 is disposed in the middle of the communication section with the pressure transducer 24. A deviation signal between the signal from the pressure transducer 24 and the signal 8 from the pressure setting device 25 is input to the first controller 26 . Further, a steam flow rate converter 27 is provided in the steam flow path 2 on the downstream side of the steam flow rate control valve 23, and the flow rate signal is transmitted to the second controller 2.
8 is entered. The signal f, which is the sum of the signals from the first controller 26 and the second controller 28, is sent to the third controller 29. It is input to the air supply fan 3θ and the fourth controller 31. The output signal of the third controller 29 is input to the opening 33 of the branch air pipe 32 to control the opening degree of the opening 4. This branch air pipe: 9.21f: , Air 35 is sent to the moving bed 34 from below by the air supply fan 30, and auxiliary combustion air 36 is sent from above. Also, the third controller 2
The output signal of 9 is input to the fifth controller 37. Fifth
A signal is input to the controller 37 from an oxygen content converter 38 that detects the oxygen content of combustion gas produced by combustion of coal and converts it into an electrical signal. The fifth controller 37
A value obtained by correcting the signal from the oxygen content converter 38 to the signal from the controller 29 is input to the coal feeding device 39 as a coal feeding control signal.

The coal feeding device 39 determines the amount of coal to be fed to the moving bed 34 based on this input signal.

The air supply fan 30 has first and second controllers 26
．． The rotation speed is controlled based on the addition signal f of 28. Further, the fourth controller 3 includes a plurality of combustion temperature measuring means 4θ.
These measuring means are provided at regular intervals along the direction of movement of the moving bed, and are formed in the seven-branch air pipe 32 to detect the movement of the moving bed. It corresponds to a plurality of control points 41 . . . provided below the controller 34. The fourth controller 31 generates a combustion temperature of each compartment 41 based on the addition signal f from the first and second controllers 26, 28 and the combustion temperature, and generates a combustion temperature signal from the measuring means 40... Based on the signal, each compartment 41... performs arithmetic processing so as to achieve this turn, and outputs the result to each compartment damper 41a.

The moving bed drum-shaped coal-fired zeira constructed in this way is
The air supply amount of the air supply fan 30 provided in the branch air pipe 32 is adjusted based on the sum signal f of the amount by which the steam pressure deviates from the set pressure value and the steam flow rate, and the damper 3
3 to adjust the amount of air blown from below the moving floor 34. Therefore, an appropriate amount of air can be supplied to generate the required combustion amount. In addition, each combustion temperature measuring means 40 .
The opening degrees of the compartments 41 and 41 are controlled so that the combustion temperature signals obtained in each section match the combustion temperature pattern of each compartment 41. Therefore, the supply amount and supply pattern of the air 35 can be minimized and optimized. Furthermore, the amount of coal to be fed that corresponds to this amount of air is accurately evaluated using the oxygen content of the combustion gas obtained by the oxygen content converter 38, and the addition signal f is corrected based on this measurement signal, so that The amount of charcoal can be adjusted to an appropriate value.

As explained above, according to the present invention, the combustion state on the movable bed surface is made uniform, the air venting is prevented from occurring, and the amount of air blown from the lower part of the movable bed is reduced. Minimum possible. Therefore, by increasing or decreasing this amount of air, the amount of combustion can be increased or decreased, and even if there are pressure fluctuations, it is possible to achieve coordination equivalent to heavy oil combustion or gas combustion.

In addition, even if the coal particle shape and coal quality change and the fuel number and quantity change, the oxygen content in the combustion gas can be detected and the amount of oxygen consumed in the supplied air flow rate can be determined. Since the amount of coal feed is controlled based on this, a remarkable effect is achieved in that an appropriate coal feed system can be realized.

[Brief explanation of drawings]

Figure 1 shows a conventional moving bed drum type coal firing system? Fig. 2 is a schematic explanatory diagram of a moving bed drum type coal-fired oven showing an embodiment of the present invention. 21... Steam flow path, 22... Superheating section, 23... Steam flow control valve, 24... Pressure converter, 25... Pressure setter, 26... First controller, 27 ... steam flow rate converter, 28 ... second controller, 29 ... third controller,
30... Air supply fan, 3... Fourth controller, 3
2... Branch air pipe, 33... Dang, 34...
Movement - floor, 35...Air, 36...Air for auxiliary combustion, 3
7... Fifth controller, 38... Oxygen content converter,'
39... Coal feeding device, 40... Combustion temperature measuring means, 4
1... Compartment, 41a... Compartment damper flat.

Claims (1)

[Claims] A branch air pipe provided below the moving bed and having a plurality of conhartement dampers along the moving direction thereof, and a plurality of combustion pipes provided above the moving bed corresponding to each conhartement damper 1 and ζ. a temperature measuring means, a controller that outputs an opening control signal to each corresponding compression damper based on the detection signal of the measuring means, and a controller that outputs an opening control signal to each corresponding compression damper; A moving bed drum type coal-fired boiler, characterized in that it is equipped with a measuring means for measuring the ratio, and a controller for outputting a coal feeding amount control signal to a moving bed coal feeding device based on a detection signal of the measuring means. .