JPH1114008A - Bed temperature controlling method and device at the time of warming bed material storage tank of pressurized fluidized bed boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bed temperature controlling method and device at the time of warming a bed material storage tank of a pressurized fluidized bed boiler which can prevent lowering of the bed temperature in the body of the pressurized fluidized bed boiler at the time of warming a bed material in the bed material storage tank. SOLUTION: At the time of warming a bed material B in a bed material storage tank 4, in response to the temperature difference 65a between the bed temperature 63a in a body 3 of a fluidized bed boiler and the bed material temperature 64a at the lower portion of the bed material storage tank 4, a close time t" outputted from a function generator 66 is inputted to an ON delay timer 54 of a pulse generator 41 so as to change the injection speed of the bed material B into the body 3 of the fluidized bed boiler from the bed material storage tank 4, while in response to the above-mentioned temperature difference 65a, a fuel bias 70 outputted from the function generator 69 is outputted to an adder 75 so as to change the supply amount of fuel 9 thus controlling the bed temperature 63a at a given value while preventing lowering of the temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling bed temperature during warming of a bed material storage tank of a pressurized fluidized bed boiler.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a conventional pressurized fluidized-bed boiler.
A fluidized-bed boiler main body 3 and a bed material storage tank 4 are provided inside the fluidized-bed boiler main body 3. A diffuser 7 composed of an air diffuser or a diffuser plate is provided, and a bed material B made of combustion ash, limestone, sand, or the like is inserted above the diffuser 7. The fuel 9 such as coal slurry and heavy oil supplied from the outside by a fuel supply device 8 such as a fuel pump in which a fluidized bed 10 is formed by pressurized air 6 blown out from the air diffuser 7 is used as a bed material. By mixing with B and performing fluid combustion, low NOx combustion and in-furnace desulfurization are possible.

A heat transfer tube 11 is provided at a position where the fluidized bed 10 is formed in the fluidized bed boiler main body 3, and a water supply 13 from a water supply device 12 such as a water supply pump is supplied to the heat transfer tube 11. When passing through the bed 11, it is heated by contact with the bed material B to become steam 14, and the steam 14 is guided to a steam turbine 15 provided outside the pressurized fluidized-bed boiler 1 to drive the steam turbine 15. Thus, the coaxial generator 16 is driven to generate electric power.

[0004] Combustion gas 17 after combustion in the fluidized bed boiler main body 3 is guided to a gas turbine 18 to drive the gas turbine 18 and, at the same time, coaxial air compressor 1.
9 to drive the generator 20 with surplus power so that the pressurized air 6 compressed to a predetermined pressure by the air compressor 19 is supplied into the pressure vessel 2. Has become.

[0005] The other end of the bed material take-out pipe 21 having one end connected to the lower portion of the fluidized bed boiler main body 3 is connected to the upper portion of the bed material storage tank 4. Is connected to a bed material extraction exhaust pipe 22 and guided to the outside of the pressure vessel 2. A bed material extraction valve 23 is provided in the middle of the bed material extraction exhaust pipe 22 guided to the outside of the pressure vessel 2. The bed material extraction valve 23 is opened to exhaust the inside of the bed material storage tank 4, so that the bed material B in the fluidized bed boiler main body 3 is removed by utilizing the pressure difference. Bed material storage tank 4 through
Can be taken out.

Further, a bed material blowing pipe 26 for blowing the pressurized air 6 in the pressure vessel 2 through a bed material injection valve 24 is connected to a lower portion of the fluidized bed boiler main body 3. The lower end of the suction pipe 28 whose upper end is connected to the lower part of the bed material storage tank 4 is connected to the bed material blowing pipe 2.
6 is connected via an L valve 27 between the fluidized bed boiler main body 3 and the bed material injection valve 24, and opens the bed material injection valve 24 to pressurize the pressure vessel 2 from the bed material blowing pipe 26. By blowing the air 6 into the L valve 27, the bed material B in the bed material storage tank 4 is sucked into the suction pipe 28.
Through the fluidized-bed boiler main body 3.

In FIG. 4, reference numeral 29 denotes a level control device for controlling the level of the bed material B in the fluidized-bed boiler main body 3 by injecting and extracting the bed material B. A level control command 39 output from the function generator 40 based on a load command 34 issued to the pressurized fluidized bed boiler 1 from a command room or the like is input, and as shown in FIG. The load command 34 is increased or decreased substantially in proportion to the increase or decrease.

Further, a detected differential pressure signal 31 from a differential pressure gauge 30 for detecting a differential pressure between an upper layer and a lower layer of the fluidized bed 10 of the fluidized bed boiler body 3 is input to the level control device 29, Is detected, so that the detected layer height matches the level control command 39,
An open / close control signal 32 is output to the bed material extraction valve 23, and an open / close control signal 33 is output to the bed material injection valve 24 as an open / close control signal 33 'via the pulse generator 41.
The bed material B is injected and withdrawn by controlling the opening and closing of the bed material extraction valve 23 and the bed material injection valve 24.

The pulse generator 41 receives an opening / closing control signal 33 output from the level controller 29 and a warming command signal 43 output from a warming controller 42 described later. Is "1" (when the bed material injection valve 24 is opened to raise the bed height of the fluidized bed 10) or when the warming command signal 43 is "1" (in the bed material storage tank 4). When the bed material injection valve 24 is opened to warm the bed material B), the logical sum signal 4 of "1"
4 and an OR signal 44 output from the OR circuit 45 and a NOT signal 47 output from the NOT circuit 46 are input, and an AND signal 48 of both signals 44 and 47 is output. AND circuit 49 and the AND circuit 4
When the logical product signal 48 output from 9 is input and the logical product signal 48 changes from “0” to “1”, a delay occurs by a preset time t (for example, about 5 [sec]). An on-delay timer 51 that outputs a delay signal 50 that changes to “1” and a delay signal 50 that is output from the on-delay timer 51 are input, and a time t ′ (for example, 10 [ sec]), the delay signal 53 that changes to “1” with a delay
An on-delay timer 54 output to the OT circuit 46, and a delay signal 50 output from the on-delay timer 51
And an OR circuit 58 from which the NOT signal 56 of the OR signal 44 output from the OR circuit 45 via the NOT circuit 55 is input, and the OR signal 57 of the two signals 50 and 56 is output.
AND signal 48 output from the AND circuit 49
Is set when "0" changes from "0" to "1" and outputs a signal 59 of "1", while the OR signal 57 output from the OR circuit 58 is reset when the OR signal 57 changes from "0" to "1". A single flip-flop 60 for outputting a signal 59 of “0”;
The signal 59 output from the single flip-flop 60 outputs the open / close control signal 33 'for opening the bed material injection valve 24 when the signal 59 output from the
Circuit 6 that outputs an open / close control signal 33 ′ for closing the bed material injection valve 24 by the NOT circuit 61 when “0” is “0”.
When the bed height of the fluidized bed 10 is increased or when the bed material B in the bed material storage tank 4 is to be warmed, the opening / closing control signal 33 'for opening the bed material injection valve 24 is set as described above. After outputting as a pulse for the time t set in the on-delay timer 51, an opening / closing control signal 33 'for closing the bed material injection valve 24 is output as a pulse for the time t' set in the setting device 52, and the bed material injection is performed. Valve 2
By repeatedly opening and closing the bed 4, the bed material B in the bed material storage tank 4 is injected into the fluidized bed boiler main body 3 at a predetermined injection speed.

Incidentally, the warming control device 42 has a low temperature of the bed material B in the bed material storage tank 4 such as immediately after the start of the pressurized fluidized bed boiler 1 and the like. The warming command signal 43 is output when bed material B having a low temperature is injected into the fluidized bed boiler main body 3 to warm it, that is, when warming needs to be performed.

Further, a fuel control command 35 output from a function generator 36 based on the load command 34 is input to the fuel supply device 8, and the water supply device 12 also receives the load command 34 The water supply control command 37 output from the function generator 38 based on this is input. The fuel control command 35 is set in advance so as to increase and decrease in a substantially proportional relationship with the increase and decrease of the load command 34, as shown in FIG. 6, in substantially the same manner as the level control command 39 of FIG. The water supply control command 37 is also increased and decreased in a substantially proportional relationship with the increase and decrease of the load command 34, as shown in FIG. 7, similarly to the level control command 39 of FIG. It is set in advance.

During normal operation of the conventional pressurized fluidized-bed boiler 1 as described above, a fuel control command 35 based on a load command 34 is transmitted from the function generator 36 to the fuel supply device 8.
And the supply amount of the fuel 9 is controlled, and a water supply control command 37 based on the load command 34 is output from the function generator 38 to the water supply device 12 to control the supply amount of the water 13 and A level control command 39 based on the command 34 is output from the function generator 40 to the level control device 29 to control the bed height of the fluidized bed 10.

In controlling the bed height of the fluidized bed 10, when the bed material injection valve 24 is opened in order to raise the bed height, the opening / closing control signal 3 output from the level controller 29 is used.
3 is input to the OR circuit 45 of the pulse generator 41 as “1”, and the OR signal 4 output from the OR circuit 45
4 changes to “1” and the NOT signal 47 output from the NOT circuit 46 also changes to “1”, and the AND signal 48 output from the AND circuit 49 changes from “0” to “1”. The flip-flop 60 is set, a signal 59 of “1” is output from the single flip-flop 60 to the opening / closing circuit 62, and an opening / closing control signal 33 ′ for opening the bed material injection valve 24 is output from the opening / closing circuit 62. Valve 24 is opened.

After the AND signal 48 output from the AND circuit 49 changes from "0" to "1", the ON delay timer 51 sets a predetermined time t (for example, 5 [s]).
ec]), the on-delay timer 51
, The OR signal 57 output from the OR circuit 58 changes from “0” to “1”, the single flip-flop 60 is reset, and the single flip-flop 60 is reset. Flip-flop 6
A signal 59 from 0 to "0" is output to the opening / closing circuit 62, and an opening / closing control signal 33 'for closing the bed material injection valve 24 is output from the opening / closing circuit 62, and the bed material injection valve 24 is closed.

After the delay signal 50 output from the on-delay timer 51 changes from "0" to "1", a predetermined time t '(for example, 10 [sec]) is set in the setting unit 52.
c)), the delay signal 53 output from the on-delay timer 54 changes from “0” to “1”, and N
Since the negation signal 47 output from the OT circuit 46 changes from “1” to “0”, the AND signal 48 output from the AND circuit 49 changes from “1” to “0”. The output delay signal 50 is "1"
From “0” to “0”.
4 changes from “1” to “0”, the NOT signal 47 output from the NOT circuit 46 changes from “0” to “1”, and the AND signal 48 output from the AND circuit 49 Changes from “0” to “1”,
The negation signal 56 output from the NOT circuit 55 remains "0" as long as the OR signal 44 is "1".
The delay signal 50 and the negation signal 56 input to the R circuit 58 both become "0", and the OR signal 57 output from the OR circuit 58 changes from "1" to "0", thereby resetting the reset signal. The set single flip-flop 60 is set again, and a signal 59 of “1” is output from the single flip-flop 60 to the opening / closing circuit 62, and the opening / closing control signal 3 for opening the bed material injection valve 24 from the opening / closing circuit 62.
3 'is output, and the bed material injection valve 24 is opened again.

Hereinafter, the same operation as described above is performed. That is, after the bed material injection valve 24 is opened for a time t set in the on-delay timer 51, the bed material injection valve 24 is closed for a time t 'set in the setter 52 and then opened again. The operation is repeatedly performed, and the bed material B in the bed material storage tank 4 is injected into the fluidized bed boiler main body 3 at a predetermined injection speed, and the bed height of the fluidized bed 10 is raised.

On the other hand, immediately after the pressurized fluidized bed boiler 1 is started, the temperature of the bed material B in the bed material storage tank 4 is low, and the bed material B in the bed material storage tank 4 having a low temperature is transferred to the fluidized bed boiler. When it is necessary to perform warming by injecting into the main body 3, so-called warming is performed, and when the warming command signal 43 is output from the warming control device 42, the bed height of the fluidized bed 10 is increased. Similarly, after the bed material injection valve 24 opens for the time t set in the on-delay timer 51, closes and opens again for the time t 'set in the setting device 52, the operation is repeatedly performed, and the predetermined injection is performed. The bed material B in the bed material storage tank 4 is injected into the fluidized bed boiler main body 3 at a speed. The bed material B in the bed material storage tank 4 is used for warming.
Is injected into the fluidized-bed boiler main body 3, and when the bed height of the fluidized bed 10 is higher than the bed height of the level control command 39 based on the load command 34, the bed material extraction valve 23 from the level controller 29. Open / close control signal 32 is output,
The injected bed material B is extracted from the fluidized-bed boiler main body 3, and the bed height of the fluidized bed 10 is maintained at a set value.

[0018]

However, as described above, the rate of injection of the bed material B from the bed material storage tank 4 to the fluidized-bed boiler body 3 during warming is controlled by the flow rate in the fluidized-bed boiler body 3. Since the bed temperature is always set to be constant regardless of the bed temperature and the temperature of the bed material B in the lower part of the bed material storage tank 4, the bed temperature in the fluidized bed boiler body 3 and the bed in the lower part of the bed material storage tank 4 When the temperature difference from the temperature of the material B is large, there is a disadvantage that the bed temperature in the fluidized-bed boiler main body 3 decreases.

Although not shown, during warming, a fuel control command 35 output from the function generator 36 to the fuel supply device 8 is interlocked with the opening operation of the bed material injection valve 24. Although bias is applied,
This is also constant, regardless of the bed temperature in the fluidized-bed boiler body 3 and the temperature of the bed material B in the lower part of the bed material storage tank 4, similarly to the injection speed of the bed material B.
Since the bias is applied only while the bed material injection valve 24 is open (time t set in the on-delay timer 51), the fuel supply device 8 does not follow the bias command,
At present, it is inevitable that the bed temperature in the fluidized-bed boiler body 3 decreases.

In view of such circumstances, the present invention provides a pressurized fluidized-bed boiler which can prevent a decrease in bed temperature in a fluidized-bed boiler body when a bed material in a bed material storage tank is warmed. It is an object of the present invention to provide a method and an apparatus for controlling a bed temperature during warming of a bed material storage tank.

[0021]

According to the present invention, when the bed material B in the bed material storage tank 4 is warmed, the bed temperature 63a in the fluidized-bed boiler body 3 and the bed in the lower part of the bed material storage tank 4 are controlled. The temperature difference 65a from the bed temperature 64a is detected, and the injection speed of the bed material B from the bed material storage tank 4 to the fluidized-bed boiler main body 3 is changed according to the temperature difference 65a. The supply amount of fuel 9 to the fluidized-bed boiler main body 3 is changed, and the fluidized-bed boiler main body 3 is changed.
The present invention relates to a method for controlling the bed temperature during warming of a bed material storage tank of a pressurized fluidized-bed boiler, wherein the bed temperature 63a is controlled to a required value.

The present invention also provides a bed temperature detector 63 for detecting a bed temperature 63a in the fluidized bed boiler main body 3, and a bed material temperature detector 64 for detecting a bed material temperature 64a in the lower part of the bed material storage tank 4. And a subtracter 65 that calculates a difference between the bed temperature 63a detected by the bed temperature detector 63 and the bed material temperature 64a detected by the bed material temperature detector 64, and outputs a temperature difference 65a. The bed material injection valve 24 during warming based on the temperature difference 65a output from the
A function generator 66 for obtaining and outputting a closing time t ″ in opening and closing of the bed, and a bed material injection valve 24 from the level controller 29.
And a warming command signal 43 from the warming control device 42 are inputted. During warming, the bed material injection valve 2 is set for a preset time t.
4, the bed material injection valve 24 is closed for the closing time t ″ output from the function generator 66, and a pulse generator 41 that outputs to the bed material injection valve 24 an open / close control signal 33 ′ that repeats this operation. The fuel bias 70 during warming based on the temperature difference 65a output from the subtractor 65.
A fuel bias 70 output from the function generator 69 is added to a function generator 69 for calculating and outputting the fuel control command 35 output to the fuel supply device 8 based on the load command 34 during warming. The pressurized fluidized-bed boiler according to the present invention relates to a bed temperature control device during warming of a bed material storage tank in a pressurized fluidized-bed boiler.

According to the above means, the following effects can be obtained.

In the bed temperature control method for warming the bed material storage tank of the pressurized fluidized bed boiler of the present invention, when the bed material B in the bed material storage tank 4 is warmed, Of the bed material B from the bed material storage tank 4 to the fluidized-bed boiler main body 3 according to the temperature difference 65a between the bed temperature 63a of the bed material storage tank 4 and the bed material temperature 64a in the lower part of the bed material storage tank 4. When the injection rate is changed and the supply amount of the fuel 9 to the fluidized-bed boiler main body 3 is changed according to the temperature difference 65a, the bed temperature 63a in the fluidized-bed boiler main body 3 is controlled to a required value, and the fluidized-bed boiler is controlled. The lowering of the layer temperature 63a in the main body 3 can be suppressed.

In the bed temperature control apparatus for warming the bed material storage tank of the pressurized fluidized bed boiler according to the present invention, when the bed material B in the bed material storage tank 4 is warmed, the bed temperature detector is used. The bed temperature 63a in the fluidized-bed boiler main body 3 is detected by 63, and the bed material temperature 64a in the lower part of the bed material storage tank 4 is detected by the bed material temperature detector 64.
Bed temperature 63a and bed material temperature detector 64 detected at 3
The difference from the bed material temperature 64a detected by the subtractor 65 is obtained in the subtractor 65, and the temperature difference 65a is output.
5, a function generator 66 based on the temperature difference 65a output from
The closing time t ″ for opening and closing the bed material injection valve 24 during warming is determined and output, and the bed material injection valve 24 is opened from the pulse generator 41 to the bed material injection valve 24 for a preset time t. After that, the bed material injection valve 24 is closed for the closing time t ″ output from the function generator 66.
An opening / closing control signal 33 'that repeats this operation is output, and after the bed material injection valve 24 is opened for a time t, the operation is repeated for a closing time t "based on the temperature difference 65a and then opened again. The bed material B in the bed material storage tank 4 is injected into the fluidized bed boiler main body 3 at a desired injection speed corresponding to the temperature difference 65a, and at the same time, a function is generated based on the temperature difference 65a output from the subtractor 65. Vessel 6
9, a fuel bias 70 at the time of warming is obtained and output, and based on the load command 34, the fuel supply device 8
The fuel bias 70 output from the function generator 69 is added to the fuel control command 35 output to the control unit 35 by the adder 75, and the supply amount of the fuel 9 is increased according to the temperature difference 65a.

As a result, if the temperature difference 65a is small, the closing time t ″ of opening and closing the bed material injection valve 24 is short, and the speed of pouring the bed material B from the bed material storage tank 4 into the fluidized bed boiler main body 3 is high. On the other hand, the fuel control command 3
5, the fuel bias 70 is small, and the increase of the fuel 9 is small. However, if the temperature difference 65a is large, the closing time t ″ in opening and closing the bed material injection valve 24 is long, and the flow from the bed material storage tank 4 is increased. While the injection speed of the bed material B into the bed boiler main body 3 is slowed down, the fuel bias 70 added to the fuel control command 35 is large, and the increase of the fuel 9 is increased, so that the bed temperature in the fluidized bed boiler main body 3 is increased. 63a is suppressed.

[0027]

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

FIGS. 1 to 3 show an example of an embodiment of the present invention. In the drawings, portions denoted by the same reference numerals as those in FIGS. 4 to 7 represent the same components. A bed temperature detector 64 for detecting a bed temperature 63a in the fluidized bed boiler main body 3;
Reference numeral 65 denotes a bed material temperature detector for detecting a bed material temperature 64a in the lower portion of the bed material storage tank 4. Reference numeral 65 denotes a bed temperature 63a detected by the bed temperature detector 63 and a bed material temperature detector 6.
The subtracter 66 calculates the difference from the bed material temperature 64a detected in step 4, and outputs a temperature difference 65a. The opening / closing of the bed material injection valve 24 during warming is performed based on the temperature difference 65a output from the subtractor 65. Is a function generator that calculates and outputs the closing time t ″ in the above. When the opening / closing control signal 33 for opening the bed material injection valve 24 is output from the level control device 29, the function generator 67 sets the time t ′ set in the setting device 52 to the setting signal. At the time of warming, when the opening / closing control signal 33 for opening the bed material injection valve 24 is not output from the level control device 29 while being output to the on-delay timer 54 of the pulse generation device 41 (switched from b to c side) as 68. The closing time t ″ output from the function generator 66 is output as a setting signal 68 to the on-delay timer 54 of the pulse generator 41 (switching to the a → c side). The switching relay 69 is a function generator that calculates and outputs the fuel bias 70 at the time of warming based on the temperature difference 65a output from the subtractor 65, and 71 is a zero as the fuel bias at the time of non-warming. The setting device 73 to which the setting signal 72 has been set, 73 outputs the setting signal 72 set in the setting device 71 as the setting signal 74 when the opening / closing control signal 33 for opening the bed material injection valve 24 is output from the level control device 29. On the other hand, the fuel bias 70 output from the function generator 69 is set at the time of warming in which the open / close control signal 33 for opening the bed material injection valve 24 is not output from the level control device 29. Output as signal 74 (a
A switching relay 75 is an adder for adding a setting signal 74 output from the switching relay 73 to a fuel control command 35 output to the fuel supply device 8 based on the load command 34. When warming the bed material B in the bed material storage tank 4, the bed temperature 63a in the fluidized bed boiler main body 3 and the bed material storage tank 4
In response to the temperature difference 65a between the inner and lower bed material temperatures 64a, the closing time t ″ output from the function generator 66 is set as a setting signal 68 via the switching relay 67 as the pulse generator 4.
1 to the on-delay timer 54 to change the injection speed of the bed material B from the bed material storage tank 4 to the fluidized-bed boiler body 3 and output from the function generator 69 according to the temperature difference 65a. The fuel bias 70 is output to the adder 75 as a setting signal 74 via the switching relay 73 to change the supply amount of the fuel 9 to the fluidized-bed boiler main body 3, and the bed temperature 63a in the fluidized-bed boiler main body 3 is set to a required value. In order to prevent the decrease.

A function as shown in FIG. 2 is set in the function generator 66.
When 5a is about 200 ° C. or less, the bed material injection valve 2
4 is about 10 [sec], and when the temperature difference 65a is in the range of about 200 to 800 [° C.], the closing time t ″ for opening and closing the bed material injection valve 24 is The temperature difference 65a is increased or decreased substantially in proportion to the increase or decrease of the temperature difference 65a between about 10 to 25 [sec]. Further, when the temperature difference 65a is about 800 [° C.] or more, opening and closing of the bed material injection valve 24 is performed. Is set to about 25 [sec]. A function as shown in FIG. 3 is set in the function generator 69, and the function is based on the temperature difference. 65a is about 200
When the temperature difference is less than 200 ° C., the fuel bias 70 is set to zero.
0 is increased or decreased in a desired curve with respect to the increase or decrease in the temperature difference 65a.

Next, the operation of the illustrated example will be described.

Immediately after the pressurized fluidized-bed boiler 1 is started, for example, the temperature of the bed material B in the bed material storage tank 4 is low, and the bed material B in the bed material storage tank 4 is low in temperature.
When the warming command signal 43 is output from the warming control device 42 when it is necessary to perform warming by injecting into the fluidized bed boiler main body 3, so-called warming, the OR circuit 45 of the pulse generating device 41 When the output OR signal 44 becomes “1”, the NOT circuit 46
Since the negation signal 47 output from is also "1", AN
The AND signal 48 output from the D circuit 49 changes from “0” to “1”, the single flip-flop 60 is set, and a signal 59 of “1” is output from the single flip-flop 60 to the switching circuit 62. An opening / closing control signal 33 'for opening the bed material injection valve 24 is output from the opening / closing circuit 62, and the bed material injection valve 24 is opened.

After the AND signal 48 output from the AND circuit 49 changes from "0" to "1", a time t (for example, 5 [s]
ec]), the on-delay timer 51
, The OR signal 57 output from the OR circuit 58 changes from “0” to “1”, the single flip-flop 60 is reset, and the single flip-flop 60 is reset. Flip-flop 6
A signal 59 from 0 to "0" is output to the opening / closing circuit 62, and an opening / closing control signal 33 'for closing the bed material injection valve 24 is output from the opening / closing circuit 62, and the bed material injection valve 24 is closed.

Here, the bed temperature 6 in the fluidized bed boiler body 3
3a is detected by the bed temperature detector 63 and the bed material temperature 64a in the lower part of the bed material storage tank 4
Is detected by the bed material temperature detector 64, and the temperature difference 65 a between the bed temperature 63 a detected by the bed temperature detector 63 and the bed material temperature 64 a detected by the bed material temperature detector 64 is subtracted by the subtractor 65. Is output to the function generator 66 and the function generator 69, and based on the temperature difference 65a output from the subtractor 65 in the function generator 66, the closing time t for opening and closing the bed material injection valve 24 during warming. Is input as a setting signal 68 to the on-delay timer 54 of the pulse generator 41 via the switching relay 67 (switched from the side a to the side c).

Therefore, after the delay signal 50 output from the on-delay timer 51 changes from "0" to "1", when the closing time t "based on the temperature difference 65a elapses, the on-delay timer 54 outputs Output delay signal 5
3 changes from “0” to “1”, and the negation signal 47 output from the NOT circuit 46 changes from “1” to “0”, and the AND signal 48 output from the AND circuit 49 changes from “1” to “1”. "0" and the on-delay timer 51
From the "1" to "0", the delay signal 53 output from the on-delay timer 54 changes from "1" to "0", and the negative signal output from the NOT circuit 46 47 changes from “0” to “1”, and the AND signal 4 output from the AND circuit 49
8 changes from “0” to “1”, while the negation signal 56 output from the NOT circuit 55 remains “0” as long as the OR signal 44 is “1”. Both the input delay signal 50 and negative signal 56 are “0”
And the logical sum signal 5 output from the OR circuit 58
7 changes from “1” to “0”, the single flip-flop 60 that has been reset is set again, and a signal 59 of “1” is output from the single flip-flop 60 to the switching circuit 62. An opening / closing control signal 33 'for opening the bed material injection valve 24 is output, and the bed material injection valve 24 is opened again.

Hereinafter, the same operation as described above, that is, after the bed material injection valve 24 is opened for the time t set in the on-delay timer 51, the closing time t ″ based on the temperature difference 65a
The bed material B in the bed material storage tank 4 is injected into the fluidized bed boiler main body 3 at a desired injection speed corresponding to the temperature difference 65a.

At the same time, the function generator 69 obtains the fuel bias 70 at the time of warming based on the temperature difference 65a output from the subtractor 65, and the switching relay 73 (switched from a to c side). A setting signal output from the switching relay 73 in response to a fuel control command 35 output to the fuel supply device 8 based on the load command 34 in the adder 75 as a setting signal 74 74, that is, the desired fuel bias 70 corresponding to the temperature difference 65a is added, and the supply amount of the fuel 9 is increased according to the temperature difference 65a.

As a result, if the temperature difference 65a is small, the closing time t ″ of opening and closing the bed material injection valve 24 is short, and the speed of injecting the bed material B from the bed material storage tank 4 to the fluidized bed boiler main body 3 is high. On the other hand, the fuel control command 3
5, the fuel bias 70 is small, and the increase of the fuel 9 is small. However, if the temperature difference 65a is large, the closing time t ″ in opening and closing the bed material injection valve 24 is long, and the flow from the bed material storage tank 4 is increased. While the injection speed of the bed material B into the bed boiler main body 3 is slowed down, the fuel bias 70 added to the fuel control command 35 is large, and the increase of the fuel 9 is increased, so that the bed temperature in the fluidized bed boiler main body 3 is increased. 63a is suppressed.

During operation of the pressurized fluidized-bed boiler 1, when the bed material injection valve 24 is opened to raise the bed height of the fluidized bed 10, the open / close control signal 33 of “1” is sent from the level controller 29. Is output, the switching relay 67
Is switched from the state of a → c to the side of b → c, and the time t ′ set in the setting unit 52 is output as the setting signal 68 to the on-delay timer 54 of the pulse generator 41, and as in the conventional case, After the bed material injection valve 24 is opened for the time t set in the on-delay timer 51, the setting device 52
The operation of closing and reopening only for the time t ′ set in the above is repeatedly performed, and the bed material B in the bed material storage tank 4 is injected into the fluidized bed boiler main body 3 at a predetermined injection speed, and the fluidized bed 10 While the layer height is raised, the switching relay 73 is switched from the state of a → c to the side of b → c,
The zero setting signal 72 set in the setting device 71 is the setting signal 7
4 is output to the adder 75, and the supply amount of the fuel 9 is controlled by the fuel control command 35 output to the fuel supply device 8 based on the load command 34 as in the conventional case.

Thus, when the bed material B in the bed material storage tank 4 is warmed, the bed temperature in the fluidized bed boiler main body 3 can be prevented from lowering.

The method and apparatus for controlling the bed temperature of the pressurized fluidized-bed boiler of the present invention at the time of warming the bed material storage tank are not limited to the above-described examples.
It goes without saying that various changes can be made without departing from the spirit of the present invention.

[0041]

As described above, according to the bed temperature control method and apparatus for the bed material storage tank of the pressurized fluidized bed boiler of the present invention, the bed material in the bed material storage tank is warmed. When performed, an excellent effect of preventing a decrease in the bed temperature in the fluidized bed boiler main body can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an example of an embodiment of the present invention.

FIG. 2 is a diagram showing functions set in a function generator 66 shown in FIG.

FIG. 3 is a diagram showing functions set in function generator 69 shown in FIG. 1;

FIG. 4 is a schematic configuration diagram of a conventional example.

FIG. 5 is a diagram showing functions set in a function generator 40 shown in FIGS. 1 and 4;

FIG. 6 is a diagram showing a function set in a function generator shown in FIGS. 1 and 4;

FIG. 7 is a diagram showing functions set in a function generator shown in FIGS. 1 and 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressurized fluidized-bed boiler 3 Fluidized-bed boiler main body 4 Bed material storage tank 8 Fuel supply device 9 Fuel 10 Fluidized bed 24 Bed material injection valve 29 Level control device 33 Opening / closing control signal 33 'Opening / closing control signal 34 Load command 35 Fuel control command Reference Signs List 41 pulse generator 42 warming controller 43 warming command signal 51 on-delay timer 54 on-delay timer 63 layer temperature detector 63a layer temperature 64 bed material temperature detector 64a bed material temperature 65 subtractor 65a temperature difference 66 function generator 69 Function generator 70 Fuel bias 75 Adder B Bed material t Time t "Closing time

Claims (2)

[Claims] When the bed material (B) in the bed material storage tank (4) is warmed, the bed temperature (63a) in the fluidized bed boiler main body (3) and the lower part in the bed material storage tank (4). Temperature difference (6a) from the bed material temperature (64a)
5a) is detected, the injection speed of the bed material (B) from the bed material storage tank (4) to the fluidized bed boiler body (3) is changed according to the temperature difference (65a), and the temperature difference (65a) is detected. ), The amount of fuel (9) supplied to the fluidized-bed boiler body (3) is changed, and the bed temperature (63a) in the fluidized-bed boiler body (3) is controlled to a required value. A bed temperature control method during bed material storage tank warming of a fluidized bed boiler. 2. The bed temperature (6) in the fluidized bed boiler body (3).
3a) a bed temperature detector (63), and a bed material temperature (64) in the lower part of the bed material storage tank (4).
a) a bed material temperature detector (64) for detecting a), and a bed temperature (63) detected by the bed temperature detector (63).
a) a difference between the bed material temperature (64a) detected by the bed material temperature detector (64) and a subtractor (65) for outputting a temperature difference (65a); and an output from the subtracter (65). A function generator (6) that calculates and outputs a closing time (t ″) for opening and closing the bed material injection valve (24) at the time of warming based on the temperature difference (65a) obtained
6) and the bed material injection valve (24) from the level control device (29)
Open / close control signal (33) and the warming control device (4
The warming command signal (43) from (2) is input. During warming, the bed material injection valve (24) is opened for a preset time (t), and then output from the function generator (66). The bed material injection valve (24) is closed for the closing time (t ″) that is performed, and the opening / closing control signal (3) is repeated.
A fuel bias (70) at the time of warming is obtained based on a pulse generator (41) that outputs 3 ′) to the bed material injection valve (24) and a temperature difference (65a) output from the subtracter (65). A function generator (69) for outputting a fuel control command (35) output to the fuel supply device (8) based on a load command (34) during warming. A bed temperature control device for warming a bed storage tank of a pressurized fluidized-bed boiler, comprising: an adder (75) for adding an output fuel bias (70).