JP3826498B2 - Method and apparatus for controlling bed temperature during warming bed storage tank of pressurized fluidized bed boiler - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bed temperature control method and apparatus during warming of a bed storage tank of a pressurized fluidized bed boiler.
[0002]
[Prior art]
FIG. 4 shows an example of a conventional pressurized fluidized bed boiler. A pressurized fluidized bed boiler 1 includes a fluidized bed boiler body 3 and a bed material storage tank 4 in a pressure vessel 2, and is fluidized. In the lower part of the layer boiler main body 3, an air diffuser 7 comprising an air diffuser tube or an air diffuser for blowing the pressurized air 6 in the pressure vessel 2 taken in from the lower air intake port 5 upward is disposed. In addition, a bed material B made of combustion ash, limestone, sand, or the like is inserted on the upper side of the air diffuser 7, and the fluidized bed 10 is generated by the pressurized air 6 blown out from the air diffuser 7. Fuel slurry 9 such as coal slurry and heavy oil supplied from the outside by a fuel supply device 8 such as a fuel pump is mixed with the bed material B and fluidly burned, so that low NOx combustion and in-furnace desulfurization are possible. It is.
[0003]
A heat transfer pipe 11 is bent at a position where the fluidized bed 10 is formed in the fluidized bed boiler body 3, and water supply 13 from a water supply apparatus 12 such as a water supply pump passes through the heat transfer pipe 11. At that time, the steam 14 is heated by contact with the bed material B, 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 to be coaxial. The generator 16 is driven to generate electric power.
[0004]
The combustion gas 17 after combustion in the fluidized bed boiler body 3 is guided to the gas turbine 18 to drive the gas turbine 18 and to drive the coaxial air compressor 19 to further surplus power. Then, the generator 20 is driven, and the pressurized air 6 compressed to a predetermined pressure by the air compressor 19 is supplied into the pressure vessel 2.
[0005]
The other end of the bed material take-out pipe 21 whose one end is connected to the lower part of the fluidized bed boiler body 3 is connected to the upper part of the bed material storage tank 4. An extraction exhaust pipe 22 is connected and led to the outside of the pressure vessel 2, and a bed material extraction valve 23 is provided in the middle of the bed material extraction exhaust pipe 22 led to the outside of the pressure vessel 2. Then, by opening the bed material extraction valve 23 and exhausting the bed material storage tank 4, the bed material B in the fluidized bed boiler body 3 is transferred via the bed material extraction pipe 21 using the pressure difference. The bed material storage tank 4 can be taken out.
[0006]
Further, a bed material blowing pipe 26 is connected to the lower part of the fluidized bed boiler body 3 so as to blow the pressurized air 6 in the pressure vessel 2 through the bed material injection valve 24, and the bed material storage. The lower end of the suction pipe 28 whose upper end is connected to the lower part of the tank 4 is connected via the L valve 27 between the fluidized bed boiler body 3 and the bed material injection valve 24 in the bed material blowing pipe 26, By opening the bed material injection valve 24 and blowing the pressurized air 6 in the pressure vessel 2 from the bed material blowing pipe 26 into the L valve 27, the bed material B in the bed material storage tank 4 is passed through the suction pipe 28. The fluidized bed boiler main body 3 can be blown.
[0007]
In FIG. 4, 29 is a level control device that controls the level of the bed material B in the fluidized bed boiler body 3 by injecting and extracting the bed material B. The level control device 29 includes a centralized command room and the like. Is supplied with 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, and the level control command 39 is, as shown in FIG. It is increased or decreased in proportion to the increase or decrease of 34.
[0008]
Further, the level control device 29 receives a detected differential pressure signal 31 from a differential pressure gauge 30 that detects the differential pressure between the upper layer and the lower layer of the fluidized bed 10 of the fluidized bed boiler body 3, and the bed height of the fluidized bed 10 is increased. And an opening / closing control signal 32 is output to the bed material extraction valve 23 and the bed material injection valve 24 is controlled to open / close so that the detected layer height matches the level control command 39. The signal 33 is output as the opening / closing control signal 33 ′ via the pulse generator 41, and the opening / closing of the bed material extraction valve 23 and the bed material injection valve 24 is controlled to inject and extract the bed material B. It has become.
[0009]
The pulse generator 41 receives an open / close control signal 33 output from the level control device 29 and a warming command signal 43 output from a warming control device 42 described later, and the open / close control signal 33 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 "(the bed material B in the bed material storage tank 4). OR circuit 45 that outputs a logical sum signal 44 of “1”, and a logical sum signal 44 output from the OR circuit 45 and a NOT circuit 46. And an AND circuit 49 that outputs a logical product signal 48 of both signals 44 and 47, and a logical product signal 48 output from the AND circuit 49. When the logical product signal 48 is input and changes from “0” to “1”, the delay signal 50 changes to “1” by causing a delay by a preset time t (for example, about 5 [sec]). And the delay signal 50 output from the on-delay timer 51 are input, and a delay is caused by a time t ′ (for example, about 10 [sec]) set in the setting device 52. An on-delay timer 54 that outputs a delay signal 53 that changes to “1” to the NOT circuit 46, a delay signal 50 that is output from the on-delay timer 51, and a logic that is output from the OR circuit 45 via the NOT circuit 55. An OR circuit 58 to which a negative signal 56 of the sum signal 44 is input and a logical sum signal 57 of both signals 50 and 56 is output, and an AND signal 4 output from the AND circuit 49. Is set when "0" changes from "0" to "1" and outputs a signal "1" 59, while resetting when the OR signal 57 output from the OR circuit 58 changes from "0" to "1" A single flip-flop 60 that outputs a signal 59 of “0” and an open / close control signal 33 ′ that opens the bed material injection valve 24 when the signal 59 output from the single flip-flop 60 is “1”. And an open / close circuit 62 for outputting an open / close control signal 33 ′ for closing the bed material injection valve 24 by the NOT circuit 61 when the signal 59 output from the single flip-flop 60 is “0”. When raising the bed height or when warming the bed material B in the bed material storage tank 4, the on / off control signal 33 ′ for opening the bed material injection valve 24 is set to the on-state signal. After being output as a pulse for the time t set in the ray 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 valve 24 is output. The bed material B in the bed material storage tank 4 is injected into the fluidized bed boiler body 3 at a predetermined injection speed by repeatedly opening and closing.
[0010]
Note that the warming control device 42 has a low temperature of the bed material B in the bed material storage tank 4 and a low temperature in the bed material storage tank 4, such as immediately after activation of the pressurized fluidized bed boiler 1. A warming command signal 43 is output when it is necessary to perform so-called warming by injecting the bed material B into the fluidized bed boiler body 3 and warming it up.
[0011]
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 a function based on the load command 34 is also input to the water supply device 12. A water supply control command 37 output from the generator 38 is input. The fuel control command 35 is set in advance so as to be increased or decreased in a substantially proportional relationship with the increase or decrease of the load command 34, as shown in FIG. 6, substantially as in the level control command 39 of FIG. Also, the water supply control command 37 is increased or decreased in a substantially proportional relationship with the increase or decrease of the load command 34, as shown in FIG. 7, as in the case of the level control command 39 of FIG. It is set in advance.
[0012]
During normal operation in the conventional pressurized fluidized bed boiler 1 as described above, the fuel control command 35 based on the load command 34 is output from the function generator 36 to the fuel supply device 8 to control the supply amount of the fuel 9. The feed water control command 37 based on the load command 34 is output from the function generator 38 to the feed water supply device 12 to control the supply amount of the feed water 13, and the level control command 39 based on the load command 34 is a function. An output from the generator 40 to the level controller 29 controls the bed height of the fluidized bed 10.
[0013]
In controlling the bed height of the fluidized bed 10, when the bed material injection valve 24 is opened in order to increase the bed height, the opening / closing control signal 33 output from the level control device 29 is set to “1” and the pulse generator 41. Since the logical sum signal 44 input to and output from the OR circuit 45 is “1” and the negative signal 47 output from the NOT circuit 46 is also “1”, the AND circuit 49 The output AND signal 48 is changed 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, and the bed material injection valve 24 is opened.
[0014]
After the logical product signal 48 output from the AND circuit 49 changes from “0” to “1”, when a time t (for example, about 5 [sec]) preset in the on-delay timer 51 elapses, The delay signal 50 output from the on-delay timer 51 changes from “0” to “1”, the logical sum signal 57 output from the OR circuit 58 changes from “0” to “1”, and the single flip-flop 60 is reset. Then, a signal 59 of “0” is output from the single flip-flop 60 to the opening / closing circuit 62, 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. It is done.
[0015]
After the delay signal 50 output from the on-delay timer 51 changes from “0” to “1”, the time t ′ (for example, about 10 [sec]) preset in the setting device 52 elapses. Since the delay signal 53 output from the delay timer 54 changes from “0” to “1” and the negative signal 47 output from the NOT circuit 46 changes from “1” to “0”, it is output from the AND circuit 49. The logical product signal 48 changes from “1” to “0”, and the delay signal 50 output from the on-delay timer 51 changes from “1” to “0”, whereby the delay signal 53 output from the on-delay timer 54. Is changed from “1” to “0”, the negative signal 47 output from the NOT circuit 46 is changed from “0” to “1”, and the logical product signal 48 output from the AND circuit 49 is changed from “0” to “0”. On the other hand, since the negative signal 56 output from the NOT circuit 55 remains “0” as long as the logical sum signal 44 is “1”, the delay signal 50 input to the OR circuit 58 Both the negative signals 56 become “0”, the logical sum signal 57 output from the OR circuit 58 changes from “1” to “0”, and the reset single flip-flop 60 is set again, A signal 59 of “1” is output from the single flip-flop 60 to the open / close circuit 62, an open / close control signal 33 ′ for opening the bed material injection valve 24 is output from the open / close circuit 62, and the bed material injection valve 24 is opened again.
[0016]
Hereinafter, the same operation as described above, that is, the operation in which the bed material injection valve 24 is opened for the time t set in the on-delay timer 51, is closed for the time t ′ set in the setting device 52, and is opened again. Repeatedly, the bed material B in the bed material storage tank 4 is injected into the fluidized bed boiler body 3 at a predetermined injection speed, and the bed height of the fluidized bed 10 is raised.
[0017]
On the other hand, immediately after the pressurized fluidized bed boiler 1 is started, the bed material B in the bed material storage tank 4 has a low temperature, and the bed material B in the bed material storage tank 4 is placed in the fluidized bed boiler body 3. When the warming command signal 43 is output from the warming control device 42 in the case where it is necessary to perform so-called warming by injecting into the fluid, as in the case of raising the bed height of the fluidized bed 10 described above, After the bed material injection valve 24 is opened only for the time t set in the on-delay timer 51, it is closed for the time t 'set in the setting device 52 and then reopened. The bed material B in the material storage tank 4 is injected into the fluidized bed boiler body 3. For warming, the bed material B in the bed material storage tank 4 is injected into the fluidized bed boiler main body 3, and 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 level control device 29 outputs an opening / closing control signal 32 for opening the bed material extraction valve 23, and the injected bed material B is extracted from the fluidized bed boiler body 3. The bed height is held at the set value.
[0018]
[Problems to be solved by the invention]
However, as described above, the injection speed of the bed material B from the bed material storage tank 4 to the fluidized bed boiler body 3 when warming is performed depends on the bed temperature in the fluidized bed boiler body 3 and the bed material storage tank 4. The temperature difference between 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 is particularly large because the temperature is always set regardless of the temperature of the lower bed material B. When it is large, it has the disadvantage that the bed temperature in the fluidized bed boiler body 3 is lowered.
[0019]
Although not shown, during warming, a bias is applied to the fuel control command 35 output from the function generator 36 to the fuel supply device 8 in conjunction with the opening operation of the bed material injection valve 24. However, 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 as well as the injection rate of the bed material B. In addition, 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, and the fluidized bed boiler. At present, a decrease in the layer temperature in the main body 3 is inevitable.
[0020]
In view of such circumstances, the present invention is a bed material storage of a pressurized fluidized bed boiler that can prevent a decrease in the bed temperature in the fluidized bed boiler body when the bed material in the bed material storage tank is warmed. An object of the present invention is to provide a layer temperature control method and apparatus during tank warming.
[0021]
[Means for Solving the Problems]
In the present invention, when the bed material B in the bed material storage tank 4 is warmed, the temperature difference 65a between the bed temperature 63a in the fluidized bed boiler body 3 and the bed material temperature 64a in the lower part in the bed material storage tank 4 is obtained. Detecting and changing the injection speed of the bed material B from the bed material storage tank 4 to the fluidized bed boiler body 3 according to the temperature difference 65a, and the fuel 9 to the fluidized bed boiler body 3 according to the temperature difference 65a The present invention relates to a bed temperature control method at the time of warming a bed material storage tank of a pressurized fluidized bed boiler, wherein the supply amount is changed and the bed temperature 63a in the fluidized bed boiler body 3 is controlled to a required value. .
[0022]
The present invention also includes a bed temperature detector 63 for detecting a bed temperature 63a in the fluidized bed boiler body 3,
A bed material temperature detector 64 for detecting a bed material temperature 64a in the lower part of the bed material storage tank 4;
A subtractor 65 for obtaining a difference between the bed temperature 63a detected by the bed temperature detector 64 and the bed temperature 63a detected by the bed temperature detector 63 and outputting a temperature difference 65a;
A function generator 66 for obtaining and outputting a closing time t ″ for opening / closing the bed material injection valve 24 during warming based on the temperature difference 65a output from the subtractor 65;
The opening / closing control signal 33 of the bed material injection valve 24 from the level control device 29 and the warming command signal 43 from the warming control device 42 are input, and at the time of warming, the bed material injection valve is set for a preset time t. 24, the bed material injection valve 24 is closed for the closing time t ″ output from the function generator 66, and an opening / closing control signal 33 ′ for repeating this operation is output to the bed material injection valve 24. ,
A function generator 69 for obtaining and outputting a fuel bias 70 during warming based on the temperature difference 65a output from the subtractor 65;
During warming, an adder 75 for adding the fuel bias 70 output from the function generator 69 to the fuel control command 35 output to the fuel supply device 8 based on the load command 34;
The present invention relates to a bed temperature control apparatus during warming of a bed material storage tank of a pressurized fluidized bed boiler.
[0023]
According to the above means, the following operation can be obtained.
[0024]
In the method for controlling the bed temperature during warming of 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, the bed temperature in the fluidized bed boiler body 3 is determined. A temperature difference 65a between 63a and the bed material temperature 64a in the lower part of the bed material storage tank 4 is detected, and the injection speed of the bed material B from the bed material storage tank 4 to the fluidized bed boiler body 3 is determined according to the temperature difference 65a. When the amount of fuel 9 supplied to the fluidized bed boiler body 3 is changed according to the temperature difference 65a, the bed temperature 63a in the fluidized bed boiler body 3 is controlled to a required value, and the fluidized bed boiler body 3 The decrease in the layer temperature 63a can be suppressed.
[0025]
Moreover, in the bed temperature control device during the warming of the bed material storage tank of the pressurized fluidized bed boiler of the present invention, the bed material B in the bed material storage tank 4 is warmed by the bed temperature detector 63 when warmed. The bed material temperature 63 a in the bed boiler body 3 is detected, and the bed material temperature 64 a in the lower part of the bed material storage tank 4 is detected by the bed material temperature detector 64, and the bed temperature detected by the bed temperature detector 63 is detected. A subtractor 65 obtains a difference between 63a and the bed material temperature 64a detected by the bed material temperature detector 64 and outputs a temperature difference 65a. Based on the temperature difference 65a output from the subtractor 65, a function generator is generated. 66, the closing time t ″ for opening and closing the bed material injection valve 24 during warming is obtained and output, and the bed material injection valve 24 is output from the pulse generator 41. After the bed material injection valve 24 is opened for a preset time t, the bed material injection valve 24 is closed for the closing time t ″ output from the function generator 66, and an opening / closing control signal 33 ′ is output repeatedly. Then, after the bed material injection valve 24 is opened for the time t, the operation is repeatedly performed such that the bed material injection valve 24 is closed for the closing time t ″ based on the temperature difference 65a and then reopened. The bed material B in the material storage tank 4 is injected into the fluidized bed boiler body 3, and at the same time, a fuel bias 70 during warming is obtained in the function generator 69 based on the temperature difference 65a output from the subtractor 65. The fuel bias 70 output from the function generator 69 is supplied to the adder 75 in response to the fuel control command 35 output to the fuel supply device 8 based on the load command 34. Are added to have, the supply amount of the fuel 9 is increased according to the temperature difference 65a.
[0026]
As a result, if the temperature difference 65a is small, the closing time t ″ for opening and closing the bed material injection valve 24 is short, and the injection rate of the bed material B from the bed material storage tank 4 to the fluidized bed boiler body 3 is fast, The fuel bias 70 added to the fuel control command 35 is small and the increase in the fuel 9 is small, but if the temperature difference 65a is large, the closing time t ″ for opening and closing the bed material injection valve 24 is long, and the bed material storage tank While the injection speed of the bed material B from 4 to the fluidized bed boiler body 3 is slow, the fuel bias 70 added to the fuel control command 35 is large and the increase in the fuel 9 is large. The lowering of the layer temperature 63a is suppressed.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0028]
1 to 3 show an example of an embodiment of the present invention. In the figure, the same reference numerals as those in FIGS. 4 to 7 denote the same parts. In FIG. A bed temperature detector for detecting the bed temperature 63 a in the boiler body 3, a bed material temperature detector 64 for detecting the bed material temperature 64 a in the lower part of the bed material storage tank 4, and a bed 65 detected by the bed temperature detector 63. The difference between the bed temperature 63a and the bed material temperature 64a detected by the bed material temperature detector 64 is obtained, and a subtractor 66 outputs a temperature difference 65a. The subtractor 66 is based on the temperature difference 65a output from the subtractor 65. The function generator 67 obtains and outputs a closing time t ″ for opening and closing the bed material injection valve 24 during the ming operation, and 67 is a setter 52 when the level control device 29 outputs the opening / closing control signal 33 for opening the bed material injection valve 24. Time set to Is output as a setting signal 68 to the on-delay timer 54 of the pulse generator 41 (switched from b to c), while an open / close control signal 33 for opening the bed material injection valve 24 is output from the level controller 29. When there is no warming, the switching relay 69 outputs the closing time t ″ output from the function generator 66 to the on-delay timer 54 of the pulse generator 41 as the setting signal 68 (switched from a to c), 69 is the subtraction A function generator for obtaining and outputting a fuel bias 70 during warming based on the temperature difference 65a output from the device 65; 71, a setting device with a zero setting signal 72 set as a fuel bias during non-warming; 73 When the opening / closing control signal 33 for opening the bed material injection valve 24 is output from the level control device 29, the setting set in the setting device 71 is performed. The function generator 69 outputs the signal 72 as the setting signal 74 (switched from b to c), while the function generator 69 does not output the opening / closing control signal 33 for opening the bed material injection valve 24 from the level controller 29. The switching relay 75 that outputs the fuel bias 70 output from the control signal 74 as a setting signal 74 (switched from a to c), 75 is in response to the fuel control command 35 output to the fuel supply device 8 based on the load command 34. This is an adder that adds a setting signal 74 output from the switching relay 73, and when warming the bed material B in the bed material storage tank 4, the bed temperature 63a in the fluidized bed boiler body 3 and the bed material. The closing time t ″ output from the function generator 66 is sent via the switching relay 67 in accordance with the temperature difference 65 a from the bed material temperature 64 a at the lower part in the storage tank 4. The setting signal 68 is input to the on-delay timer 54 of the pulse generator 41 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 to change the function according to the temperature difference 65a. The fuel bias 70 output from the generator 69 is output as a setting signal 74 to the adder 75 via the switching relay 73, and the amount of fuel 9 supplied to the fluidized bed boiler body 3 is changed, so that the fluidized bed boiler body 3 The layer temperature 63a is controlled to a required value to prevent the decrease.
[0029]
The function generator 66 is set with a function as shown in FIG. 2, and this function is used to open and close the bed material injection valve 24 when the temperature difference 65 a is about 200 ° C. or less. When the closing time t ″ is about 10 [sec] and 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 about 10 to 10 seconds. Increase / decrease in proportion to the increase / decrease of the temperature difference 65a during 25 [sec], and when the temperature difference 65a is about 800 [° C.] or more, the closing time t for opening / closing the bed material injection valve 24 "Is about 25 [sec]. Further, a function as shown in FIG. 3 is set in the function generator 69, and the function has a temperature difference 65a of about 200. Fuel bias when below [℃] 0 was zero, when the temperature difference 65a is greater than about 200 fuel bias 70, to increase or decrease of the temperature difference 65a represents that increase or decrease in a desired curve.
[0030]
Next, the operation of the illustrated example will be described.
[0031]
Immediately after starting up the pressurized fluidized bed boiler 1, the bed material B in the bed material storage tank 4 has a low temperature, and the bed material B having a low temperature in the bed material storage tank 4 is injected into the fluidized bed boiler body 3. When the warming command signal 43 is output from the warming control device 42 when it is necessary to perform so-called warming, the logical sum signal 44 output from the OR circuit 45 of the pulse generator 41 is “ 1 and the negative signal 47 output from the NOT circuit 46 is also “1”. Therefore, the logical product signal 48 output from the AND circuit 49 is changed from “0” to “1”, and the single flip-flop 60 is turned on. The single flip-flop 60 outputs a signal 59 of “1” to the open / close circuit 62, and the open / close control signal for opening the bed material injection valve 24 from the open / close circuit 62. 33 'are output, the bed material injection valve 24 is opened.
[0032]
After the logical product signal 48 output from the AND circuit 49 changes from “0” to “1”, when a time t (for example, about 5 [sec]) preset in the on-delay timer 51 elapses, The delay signal 50 output from the on-delay timer 51 changes from “0” to “1”, the logical sum signal 57 output from the OR circuit 58 changes from “0” to “1”, and the single flip-flop 60 is reset. Then, a signal 59 of “0” is output from the single flip-flop 60 to the opening / closing circuit 62, 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. It is done.
[0033]
Here, the bed temperature 63 a in the fluidized bed boiler body 3 is detected by the bed temperature detector 63, and the bed material temperature 64 a in the lower part of the bed material storage tank 4 is detected by the bed material temperature detector 64. The subtractor 65 obtains a temperature difference 65a between the layer temperature 63a detected by the layer temperature detector 63 and the bed material temperature 64a detected by the bed material temperature detector 64, and a function generator 66 and a function generator are obtained. 69, and the function generator 66 obtains the closing time t ″ for opening / closing the bed material injection valve 24 during warming based on the temperature difference 65a output from the subtractor 65, and the switching relay 67 (a → c side) To the on-delay timer 54 of the pulse generator 41 as a setting signal 68.
[0034]
For this reason, 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 65 a elapses, it is output from the on-delay timer 54. Since the delay signal 53 changes from “0” to “1” and the negative signal 47 output from the NOT circuit 46 changes from “1” to “0”, the logical product signal 48 output from the AND circuit 49 becomes “1”. The delay signal 50 output from the on-delay timer 51 is changed from “1” to “0”, whereby the delay signal 53 output from the on-delay timer 54 is changed from “1” to “0”. The negative signal 47 output from the NOT circuit 46 changes from “0” to “1”, and the logical product signal 48 output from the AND circuit 49 changes from “0” to “1”, while N Since the negative signal 56 output from the T circuit 55 remains “0” as long as the logical sum signal 44 is “1”, both the delayed signal 50 and the negative signal 56 input to the OR circuit 58 are combined. The logical sum signal 57 output from the OR circuit 58 is changed from “1” to “0”, and the reset single flip-flop 60 is set again. 1 "is output to the open / close circuit 62, an open / close control signal 33 'for opening the bed material injection valve 24 is output from the open / close circuit 62, and the bed material injection valve 24 is opened again.
[0035]
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 operation is closed for the closing time t ″ based on the temperature difference 65a and then opened again. Repeatedly, the bed material B in the bed material storage tank 4 is injected into the fluidized bed boiler body 3 at a desired injection rate corresponding to the temperature difference 65a.
[0036]
At the same time, the function generator 69 obtains the warming fuel bias 70 on the basis of the temperature difference 65a output from the subtractor 65 and switches it through the switching relay 73 (switched from a to c). A setting signal 74 output from the switching relay 73 in response to the fuel control command 35 input to the adder 75 as the setting signal 74 and output to the fuel supply device 8 based on the load command 34 in the adder 75, that is, A 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.
[0037]
As a result, if the temperature difference 65a is small, the closing time t ″ for opening and closing the bed material injection valve 24 is short, and the injection rate of the bed material B from the bed material storage tank 4 to the fluidized bed boiler body 3 is fast, The fuel bias 70 added to the fuel control command 35 is small and the increase in the fuel 9 is small, but if the temperature difference 65a is large, the closing time t ″ for opening and closing the bed material injection valve 24 is long, and the bed material storage tank While the injection speed of the bed material B from 4 to the fluidized bed boiler body 3 is slow, the fuel bias 70 added to the fuel control command 35 is large and the increase in the fuel 9 is large. The lowering of the layer temperature 63a is suppressed.
[0038]
In the operation of the pressurized fluidized bed boiler 1, when the bed material injection valve 24 is opened in order to raise the bed height of the fluidized bed 10, an opening / closing control signal 33 of “1” is output from the level controller 29. Then, the switching relay 67 is switched from the a → c side state to the b → c side, and the time t ′ set in the setting device 52 is output as the setting signal 68 to the on-delay timer 54 of the pulse generator 41. 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, it is closed for the time t 'set in the setting device 52 and then opened again. The bed material B in the bed material storage tank 4 is injected into the fluidized bed boiler body 3 at a predetermined injection speed, and the bed height of the fluidized bed 10 is raised while the switching relay 73 is in the state of a → c. To b → c side The zero setting signal 72 set in the setting device 71 is output to the adder 75 as the setting signal 74 and is output to the fuel supply device 8 based on the load command 34 as in the conventional case. 35 controls the amount of fuel 9 supplied.
[0039]
Thus, when the bed material B in the bed material storage tank 4 is warmed, a decrease in the bed temperature in the fluidized bed boiler body 3 can be prevented.
[0040]
In addition, the bed temperature control method and apparatus at the time of warming the bed material storage tank of the pressurized fluidized bed boiler of the present invention are not limited to the above illustrated examples, and within the scope not departing from the gist of the present invention. Of course, various changes can be made.
[0041]
【The invention's effect】
As described above, according to the bed temperature control method and apparatus during warming of the bed material storage tank of the pressurized fluidized bed boiler of the present invention, when the bed material in the bed material storage tank is warmed, The outstanding effect that the fall of the bed temperature in a fluidized-bed boiler main body can be prevented can be show | played.
[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 representing a function set in function generator 66 shown in FIG.
FIG. 3 is a diagram representing a function set in the 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 the function generator 40 shown in FIGS. 1 and 4;
6 is a diagram representing a function set in the function generator 36 shown in FIGS. 1 and 4. FIG.
7 is a diagram showing a function set in the function generator 38 shown in FIGS. 1 and 4. FIG.
[Explanation of symbols]
1 Pressurized fluidized bed boiler
3 Fluidized bed boiler body
4 Bed material storage tank
8 Fuel supply device
9 Fuel
10 Fluidized bed
24 Bed material injection valve
29 level controller
33 Open / close control signal
33 'Open / close control signal
34 Load command
35 Fuel control command
41 Pulse generator
42 Warming control device
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 hours
t ”Closing time

Claims (2)

When warming the bed material (B) in the bed material storage tank (4), the bed temperature (63a) in the fluidized bed boiler body (3) and the bed material temperature in the lower part of the bed material storage tank (4) ( 64a) is detected, and 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). At the same time, the amount of fuel (9) supplied to the fluidized bed boiler body (3) is changed according to the temperature difference (65a), and the bed temperature (63a) in the fluidized bed boiler body (3) is controlled to a required value. A bed temperature control method for warming a bed material storage tank of a pressurized fluidized bed boiler. A bed temperature detector (63) for detecting a bed temperature (63a) in the fluidized bed boiler body (3);
A bed material temperature detector (64) for detecting the bed material temperature (64a) in the lower part of the bed material storage tank (4);
The difference between the layer temperature (63a) detected by the layer temperature detector (63) and the bed material temperature (64a) detected by the bed material temperature detector (64) is obtained, and the temperature difference (65a) is output. A subtractor (65);
A function generator (66) for obtaining and outputting a closing time (t ″) in opening and closing of the bed material injection valve (24) during warming based on the temperature difference (65a) output from the subtractor (65);
The opening / closing control signal (33) of the bed material injection valve (24) from the level control device (29) and the warming command signal (43) from the warming control device (42) are input. After opening the bed material injection valve (24) for a set time (t), the bed material injection valve (24) is closed for the closing time (t ″) output from the function generator (66). A pulse generator (41) for outputting a repeating open / close control signal (33 ') to the bed material injection valve (24);
A function generator (69) for obtaining and outputting a fuel bias (70) during warming based on the temperature difference (65a) output from the subtractor (65);
At the time of warming, the fuel bias (70) output from the function generator (69) is added to the fuel control command (35) output to the fuel supply device (8) based on the load command (34). A bed temperature control device for warming a bed material storage tank of a pressurized fluidized bed boiler, comprising an adder (75).

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