A feedforward system and method for main control of a variable load boiler with adaptive function

Abstract

The present invention relates to the field of electric power technology, and specifically to a variable load boiler main control feedforward system and method with adaptive functions. The present invention realizes variable load feedforward that is closer to the adjustment method of operating operators in actual process production, which is more practical. The idea of ​​artificial intelligence automatic control is realized through logical control, which reduces the workload of operators and meets actual needs. It can realize differential output of feedforward in different intervals of variable load, which is more conducive to timely action and timely callback of coal quantity than conventional differential feedforward. The variable load furnace main control feedforward used can perform adaptive adjustment of feedforward according to different variable load amplitudes and different load sections, which is more conducive to the utilization of boiler heat storage and the coal action amount meets actual needs, thereby solving the problems of frequent action, overshoot of coal quantity and untimely callback of coal quantity in the existing boiler main control differential feedforward technology.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a variable load boiler main control feedforward system and method with adaptive function. Background Art

[0002] AGC is an automatic power generation control system for thermal power units. It sends the target load to the power plant according to the rules of the power grid and achieves the stability of the power grid load and frequency through their automatic adjustment control.

[0003] Since coal combustion has a lag, while the unit's load response requires rapidity, in order to resolve the conflict between the two and meet the relevant indicators of the power grid AGC, thermal power units are currently equipped with boiler master control differential feedforward in the control system.

[0004] In recent years, with the changes in the proportion of the energy industry structure, the proportion of wind and solar energy has increased, while the proportion of thermal power industry has decreased, resulting in a sharp increase in the adjustment range and frequency of power grid load instructions. At the same time, in order to improve the economic efficiency of thermal power units and further reduce costs, the deviation of the type of coal burned from the designed type of coal has gradually increased, and the conflict between the lag of coal combustion and the timely and accurate response of the power grid load instruction has become more prominent.

[0005] Conventional variable load differential feedforward can easily cause the following problems:

[0006] 1. Frequent action of coal quantity. Frequent small fluctuations in AGC instructions lead to frequent action of coal quantity differential feedforward, which in turn causes unstable combustion and large fluctuations in coal quantity.

[0007] 2. Large overshoot of coal quantity. When the deviation between the AGC command and the AGC command after speed limit does not disappear, the differential feedforward of the boiler master control is always in effect. This situation will easily lead to continuous action of the coal quantity, resulting in a large overshoot of the coal quantity in the later stage of the load command response.

[0008] 3. The coal quantity is not adjusted back in time. During the period when the deviation between the AGC instruction and the AGC instruction after the speed limit exists, the coal quantity continues to be output, resulting in the coal quantity being adjusted back in time.

[0009] Large overshoot, untimely adjustment and frequent fluctuations in coal quantity will lead to unstable combustion, large fluctuations in main steam pressure and temperature, large fluctuations in feed water flow, air supply volume and primary air pressure control, which will cause wall temperature to exceed the limit, large-scale generation of oxide scale, and tripping of corresponding coal mills, fans and other equipment. In more serious cases, it may cause abnormal shutdown of the unit. Summary of the invention

[0010] The purpose of the present invention is to provide a variable load boiler master control feedforward system and method with adaptive function, aiming to solve the problems of frequent action, coal quantity overshoot and untimely coal quantity callback in the existing boiler master control differential feedforward technology.

[0011] To achieve the above-mentioned purpose, in the first aspect, a variable load boiler main control feedforward system with adaptive function includes a lifting load judgment module, an artificial intelligence control variable load boiler feedforward module and a variable load amplitude and load segment adaptive module, wherein the lifting load judgment module, the artificial intelligence control variable load boiler feedforward module, and the variable load amplitude and load segment adaptive module are connected in sequence;

[0012] The load lifting and lowering judgment module is used to determine whether the current load should be raised or lowered according to the deviation between the AGC instruction and the LDC instruction given by the power grid;

[0013] The artificial intelligence-simulated variable load boiler feedforward module is used to calculate the variable load time according to the signal triggered by the variable load, and to simulate manual calculation of the feedforward amount of the boiler master control in different time periods;

[0014] The variable load amplitude and load segment adaptive module is used to calculate the correction of the boiler master control feedforward amount due to the deviation of the AGC instruction and the LDC instruction, and calculate the correction of the boiler master control feedforward amount due to the boiler heat storage in different load segments; after the two are coupled, the boiler master control variable load feedforward amount calculated by the artificial intelligence control variable load boiler feedforward module is corrected according to the weight proportional coefficient to obtain the final variable load boiler master control feedforward amount.

[0015] The lifting load judgment module includes a first subtractor, a first comparator, a second comparator, a first AND gate, a second AND gate and a first OR gate; the first comparator and the second comparator are both connected to the first subtractor, the first AND gate is connected to the first comparator, the second AND gate is connected to the second comparator, and the first OR gate is connected to the first AND gate and the second AND gate;

[0016] The first subtractor obtains a deviation between the AGC instruction and the LDC instruction based on the AGC instruction and the LDC instruction on the grid side;

[0017] The first comparator is used to compare the first constant and the deviation between the AGC instruction and the LDC instruction to obtain a first comparison result and a first load;

[0018] The second comparator is used to compare the second constant and the deviation between the AGC instruction and the LDC instruction to obtain a second comparison result and a second load;

[0019] the first AND gate outputting a load increase based on the first comparison result and the first load;

[0020] the second AND gate, based on the second comparison result and the second load output, reduces the load;

[0021] The first OR gate determines the load change based on the load increase and the load decrease.

[0022] Wherein, the artificial intelligence control variable load boiler feedforward module includes a first delay unit, a first NOT gate, a second subtractor, a first absolute value device, a first function generator, a third comparator, a second OR gate, a first time timer and a second function generator; the second subtractor, the first absolute value device, the first function generator, the third comparator, the second OR gate and the first NOT gate are connected in sequence, the first delay unit is connected in sequence with the first time timer and the second function generator, and the first timer is connected with the second OR gate and the third comparator respectively;

[0023] The second subtractor outputs a command deviation value based on the AGC command and the LDC command;

[0024] The first absolute value device takes an absolute value based on the command deviation value;

[0025] the first function generator outputs a result based on the absolute value;

[0026] The first time timer is used to output the timing result;

[0027] The third comparator is used to compare the absolute value result and the timing result, and output the comparison result and the variable load signal;

[0028] The first NOT gate obtains an output result based on the comparison result and the variable load signal;

[0029] The second OR gate is used to output the output result to the first time timer to reset the time accumulation;

[0030] The first delay unit inputs the result into the first time timer to trigger time accumulation based on the variable load signal;

[0031] The second function generator calculates the boiler main control feedforward action amount in different time periods of variable load based on the output result of the first time timer.

[0032] Wherein, the variable load amplitude and load segment adaptive module includes a first delay device, a second delay device, a third subtractor, a third function generator, a fourth function generator, a fifth function generator, a sixth function generator, a seventh function generator, an eighth function generator, a first multiplier, a second multiplier, a third multiplier, a first selector and a second selector;

[0033] The first delay device outputs a first selection judgment signal based on the load reduction signal;

[0034] The second delay device outputs a second selection judgment signal based on the load increase signal;

[0035] The third subtractor outputs an output instruction deviation value based on the grid-side AGC instruction and the LDC instruction;

[0036] The fourth function generator outputs a result based on the instruction deviation value;

[0037] The sixth function generator outputs a result based on the instruction deviation value;

[0038] The eighth function generator outputs a result based on the instruction deviation value;

[0039] The third function generator outputs a result based on the LDC instruction;

[0040] The fifth function generator outputs a result based on the LDC instruction;

[0041] The seventh function generator outputs a result based on the LDC instruction;

[0042] The first multiplier performs calculation based on the result of the fourth function generator and the result of the third function generator to obtain a first calculation result;

[0043] The second multiplier performs calculation based on the result of the sixth function generator and the result of the fifth function generator to obtain a second calculation result;

[0044] The third multiplier performs calculation based on the result of the eighth function generator and the result of the seventh function generator to obtain a third calculation result;

[0045] the first selector outputting data to the second selector based on the second selection determination signal, the first calculation result and the second calculation result;

[0046] The second selector outputs the third calculation result when the load is reduced; outputs the second calculation result when the load is increased; and outputs the first calculation result when the load is stabilized.

[0047] Wherein, the variable load boiler master control feedforward system with adaptive function also includes a fourth multiplier, a first limiter module, a second NOT gate and a third selector;

[0048] The fourth multiplier is used to input the output result of the second selector;

[0049] The first clipping module is used to clip the output result of the second selector and input the clipping result to the third selector;

[0050] The second NOT gate outputs a triggering judgment signal based on the CCS signal;

[0051] The third selector outputs a third constant based on the trigger judgment signal.

[0052] In a second aspect, a variable load boiler master control feedforward method with adaptive function is used in the variable load boiler master control feedforward system with adaptive function described in the first aspect, comprising the following steps:

[0053] The load increase and decrease judgment module determines whether the current load should be increased or decreased according to the deviation between the AGC command and the LDC command given by the power grid;

[0054] The artificial intelligence-controlled variable load boiler feedforward module calculates the variable load time according to the signal triggered by the variable load, and artificially calculates the feedforward amount of the boiler master control in different time periods;

[0055] The variable load amplitude and load segment adaptive module calculates the deviation between the AGC instruction and the LDC instruction to correct the boiler master control feedforward amount, and calculates the correction of the boiler master control feedforward amount by the boiler heat storage in different load segments. After the two are coupled, the boiler master control variable load feedforward amount calculated by the artificial intelligence control variable load boiler feedforward module is corrected according to the weight proportional coefficient to obtain the final variable load boiler master control feedforward amount.

[0056] The invention discloses a variable load boiler main control feedforward system with adaptive function, comprising a load lifting judgment module, an artificial intelligence controlled variable load boiler feedforward module and a variable load amplitude and load segment adaptive module, wherein the load lifting judgment module is used to judge whether the current load is increased or decreased according to the deviation of the AGC instruction and the LDC instruction given by the power grid; the artificial intelligence controlled variable load boiler feedforward module is used to calculate the variable load time according to the signal triggered by the variable load, and artificially calculate the feedforward amount of the boiler main control in different time periods; the variable load amplitude and load segment adaptive module is used to calculate the correction of the deviation of the AGC instruction and the LDC instruction on the boiler main control feedforward amount, and calculate the correction of the boiler main control feedforward amount by the boiler heat storage in different load segments; after the two are coupled, the boiler main control variable load feedforward amount calculated by the artificial intelligence controlled variable load boiler feedforward module is corrected according to the weight ratio coefficient to obtain the final variable load boiler main control feedforward amount. The variable load boiler main control feedforward of the invention is artificially controlled, so that the variable load feedforward amount is closer to the adjustment method of the operating operator in the actual process production, which is more practical. Through logical control, artificial intelligence-like automatic control ideas are realized, which reduces the workload of operators and is more in line with actual needs. It can realize differential output of feedforward quantities in different intervals of variable load, which is more conducive to timely action and timely callback of coal quantity than conventional differential feedforward. The variable load furnace master control feedforward adopted can adaptively adjust the feedforward quantity according to different variable load amplitudes and different load sections, which is more conducive to the utilization of boiler heat storage and the coal quantity action quantity meeting actual needs, thereby solving the problems of frequent action, overshoot of coal quantity and untimely callback of coal quantity in the existing boiler master control differential feedforward technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0058] Figure 1 It is a schematic diagram of a variable load boiler master control feedforward system with adaptive function provided by the present invention.

[0059] Figure 2 The present invention provides a flow chart of a variable load boiler master control feedforward method with adaptive function.

[0060] 1- load lifting judgment module, 2- artificial intelligence control variable load boiler feedforward module, 3- variable load amplitude and load segment adaptive module, 4- first delay unit, 5- first NOT gate, 6- second subtractor, 7- first absolute value device, 8- first function generator, 9- third comparator, 10- second OR gate, 11- first time counter, 12- second function generator, 13- fourth multiplier, 14- first limit module, 15- second NOT gate, 16- third selector, 17- third constant, 18- first delay device, 19- second delay , 20-third function generator, 21-fourth function generator, 22-fifth function generator, 23-sixth function generator, 24-seventh function generator, 25-eighth function generator, 26-third subtractor, 27-first multiplier, 28-second multiplier, 29-third multiplier, 30-first selector, 31-second selector, 32-first subtractor, 33-first comparator, 34-first constant, 35-second comparator, 36-second constant, 37-second AND gate, 38-first AND gate, 39-first OR gate. DETAILED DESCRIPTION

[0061] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0062] See also Figure 1 In the first aspect, a variable load boiler master control feedforward system with adaptive function comprises a lifting load judgment module 1, an artificial intelligence controlled variable load boiler feedforward module 2 and a variable load amplitude and load segment adaptive module 3, wherein the lifting load judgment module 1, the artificial intelligence controlled variable load boiler feedforward module 2 and the variable load amplitude and load segment adaptive module 3 are connected in sequence;

[0063] The load lifting and lowering judgment module 1 is used to determine whether the current load is increased or decreased according to the deviation between the AGC instruction and the LDC instruction given by the power grid;

[0064] The artificial intelligence-simulated variable load boiler feedforward module 2 is used to calculate the variable load time according to the signal triggered by the variable load, and to artificially calculate the feedforward amount of the boiler master control in different time periods;

[0065] The variable load amplitude and load segment adaptive module 3 is used to calculate the correction of the boiler master control feedforward amount due to the deviation of the AGC instruction and the LDC instruction, and calculate the correction of the boiler master control feedforward amount due to the boiler heat storage in different load segments; after the two are coupled, the boiler master control variable load feedforward amount calculated by the artificial intelligence control variable load boiler feedforward module 2 is corrected according to the weight proportional coefficient to obtain the final variable load boiler master control feedforward amount.

[0066] In this embodiment, the variable load boiler master feedforward of the present invention simulates manual control, and the variable load feedforward is closer to the adjustment method of the operating personnel in the actual process production, which is more practical. The idea of ​​simulating artificial intelligence automatic control is realized through logical control, which reduces the workload of operators and is more in line with actual needs. It can realize the differential output of the feedforward of different intervals of variable load, which is more conducive to the timely action and timely callback of the coal quantity than the conventional differential feedforward; the variable load furnace master feedforward used can perform adaptive adjustment of the feedforward according to different variable load amplitudes and different load sections, which is more conducive to the utilization of boiler heat storage and the coal quantity action quantity meets actual needs, thereby solving the problems of frequent action, overshoot of coal quantity and untimely callback of coal quantity in the existing boiler master control differential feedforward technology.

[0067] Further, the lifting load judgment module 1 includes a first subtractor 32, a first comparator 33, a second comparator 35, a first AND gate 38, a second AND gate 37 and a first OR gate 39; the first comparator 33 and the second comparator 35 are both connected to the first subtractor 32, the first AND gate 38 is connected to the first comparator 33, the second AND gate 37 is connected to the second comparator 35, and the first OR gate 39 is connected to the first AND gate 38 and the second AND gate 37;

[0068] The first subtractor 32 obtains a deviation between the AGC instruction and the LDC instruction based on the AGC instruction and the LDC instruction on the grid side;

[0069] The first comparator 33 is used to compare the first constant 34 with the deviation between the AGC instruction and the LDC instruction to obtain a first comparison result and a first load;

[0070] The second comparator 35 is used to compare the second constant 36 with the deviation between the AGC instruction and the LDC instruction to obtain a second comparison result and a second load;

[0071] The first AND gate 38 increases load based on the first comparison result and the first load output;

[0072] The second AND gate 37 reduces the load based on the second comparison result and the second load output;

[0073] The first OR gate 39 determines whether to change the load based on the load increase and the load decrease.

[0074] In this embodiment, the grid-side AGC instruction and LDC instruction (AGC instruction after speed limit) are input into the first subtractor 32 to obtain the deviation between the AGC instruction and the LDC instruction, which is used for the subsequent determination of variable load. The output result of the first subtractor 32 and the first constant 34 are input into the first comparator 33 for comparison, and the comparison result and the load are input into the first AND gate 38 for signal comparison and then output to the load increase. The output result of the first subtractor 32 and the second constant 36 are input into the second comparator 35 for comparison, and the output result and the load are input into the second AND gate 37 for signal comparison and then output to the load reduction. The output results of the first AND gate 38 and the second AND gate 37 are input into the first OR gate 39 for the determination of variable load.

[0075] Further, the artificial intelligence controlled variable load boiler feedforward module 2 includes a first delay unit 4, a first NOT gate 5, a second subtractor 6, a first absolute value device 7, a first function generator 8, a third comparator 9, a second OR gate 10, a first time timer 11 and a second function generator 12; the second subtractor 6, the first absolute value device 7, the first function generator 8, the third comparator 9, the second OR gate 10 and the first NOT gate 5 are connected in sequence, the first delay unit 4 is connected in sequence with the first time timer 11 and the second function generator 12, and the first timer is respectively connected with the second OR gate 10 and the third comparator 9;

[0076] The second subtractor 6 outputs a command deviation value based on the AGC command and the LDC command;

[0077] The first absolute value device 7 takes an absolute value based on the command deviation value;

[0078] The first function generator 8 outputs a result based on the absolute value;

[0079] The first time timer 11 is used to output the timing result;

[0080] The third comparator 9 is used to compare the absolute value result and the timing result, and output the comparison result and the variable load signal;

[0081] The first NOT gate 5 obtains an output result based on the comparison result and the variable load signal;

[0082] The second OR gate 10 is used to output the output result to the first time timer 11 to reset the time accumulation;

[0083] The first delay unit 4 inputs the result into the first time timer 11 to trigger the time accumulation based on the variable load signal;

[0084] The second function generator 12 calculates the boiler master control feedforward action amount in different time periods of variable load based on the output result of the first time timer 11.

[0085] In this embodiment, the grid-side AGC instruction and LDC instruction (AGC instruction after speed limit) are input into the second subtractor 6, and the output result instruction deviation value is input into the first absolute value device 7 to take the absolute value and then input into the first function generator 8. The output result and the output result of the first time timer 11 are input into the first comparator 33 together. After the comparison result is output, the output result obtained after the variable load signal is input into the first NOT gate 5 is input into the first OR gate 39 together. The result is output to the RS pin of the first time timer 11, which is used to reset the time accumulation of the first time timer 11. The result obtained after the variable load signal is input into the first delay unit 4 is output to the input pin of the first time timer 11, which is used to trigger the time accumulation of the first time timer 11. The output result of the first time timer 11 is input into the second function generator 12, which is used to calculate the feedforward action amount of the boiler master control in different time periods of variable load.

[0086] Further, the variable load amplitude and load segment adaptive module 3 includes a first delay 18, a second delay 19, a third subtractor 26, a third function generator 20, a fourth function generator 21, a fifth function generator 22, a sixth function generator 23, a seventh function generator 24, an eighth function generator 25, a first multiplier 27, a second multiplier 28, a third multiplier 29, a first selector 30 and a second selector 31;

[0087] The first delay device 18 outputs a first selection judgment signal based on the load reduction signal;

[0088] The second delay device 19 outputs a second selection judgment signal based on the load increase signal;

[0089] The third subtractor 26 outputs an output command deviation value based on the grid-side AGC command and the LDC command;

[0090] The fourth function generator 21 outputs a result based on the instruction deviation value;

[0091] The sixth function generator 23 outputs a result based on the instruction deviation value;

[0092] The eighth function generator 25 outputs a result based on the command deviation value;

[0093] The third function generator 20 outputs a result based on the LDC instruction;

[0094] The fifth function generator 22 outputs a result based on the LDC instruction;

[0095] The seventh function generator 24 outputs a result based on the LDC instruction;

[0096] The first multiplier 27 performs calculation based on the result of the fourth function generator 21 and the result of the third function generator 20 to obtain a first calculation result;

[0097] The second multiplier 28 performs calculation based on the result of the sixth function generator 23 and the result of the fifth function generator 22 to obtain a second calculation result;

[0098] The third multiplier 29 performs calculation based on the result of the eighth function generator 25 and the result of the seventh function generator 24 to obtain a third calculation result;

[0099] The first selector 30 outputs data to the second selector 31 based on the second selection judgment signal, the first calculation result and the second calculation result;

[0100] The second selector 31 outputs the third calculation result when the load is reduced; outputs the second calculation result when the load is increased; and outputs the first calculation result when the load is stabilized.

[0101] In this embodiment, the load reduction signal is input to the first delay device 18, and its output is sent to the second selector 31 as a selection judgment signal. The load increase signal is input to the second delay device 19, and its output is sent to the first selector 30 as a selection judgment signal. The grid-side AGC instruction and the LDC instruction (AGC instruction after speed limit) are input to the third subtractor 26, and the output result instruction deviation value obtained is respectively input to the fourth function generator 21, the sixth function generator 23, and the eighth function generator 25, and the results are respectively sent to the first multiplier 27, the second multiplier 28, and the third multiplier 29, and the corresponding LDC instruction (AGC instruction after speed limit) is multiplied by the results of the third function generator 20, the fifth function generator 22, and the seventh function generator 24, and then sent to the N end of the first selector 30, the Y end of the first selector 30, and the Y end of the second selector 31. The output of the first selector 30 is sent to the N end of the second selector 31. When the load is reduced, the Y-end input of the second selector 31 is used as the selector output; when the load is increased, the N-end input of the second selector 31 is used as the selector output, and the Y-end input of the first selector 30 is output to the N-end of the second selector 31; when the load is stabilized, the N-end input of the second selector 31 is used as the selector output, and the N-end input of the first selector 30 is output to the N-end of the second selector 31. Through the above switching, when the load is reduced, the calculation result of the third multiplier 29 is output; when the load is increased, the calculation result of the second multiplier 28 is output, and when the load is stabilized, the calculation result of the first multiplier 27 is output. In this way, the adaptive correction of the boiler master control feedforward quantity of different variable load amplitudes and different load sections is realized.

[0102] Furthermore, the variable load boiler master control feedforward system with adaptive function also includes a fourth multiplier 13, a first limiter module 14, a second NOT gate 15 and a third selector 16;

[0103] The fourth multiplier 13 is used to input the output result of the second selector 31;

[0104] The first limiting module 14 is used to limit the output result of the second selector 31 and input the limiting result to the third selector 16;

[0105] The second NOT gate 15 outputs a starting judgment signal based on the CCS signal;

[0106] The third selector 16 outputs a third constant 17 based on the trigger determination signal.

[0107] In this embodiment, the output of the second selector 31 and the output of the second function generator 12 are sent to the first multiplier 27, and the output result is sent to the first limit module 14 for limiting, and the result is sent to the N terminal of the third selector 16. The CCS signal is sent to the first NOT gate 5, and the output result is sent to the third selector 16 as a trigger judgment signal. When it is triggered, the output of the third selector 16 selects the first constant 34 of the output Y terminal, otherwise it selects the output of the third selector 16 N terminal.

[0108] Embodiment 1:

[0109] As shown in the figure, the variable load boiler master control feedforward system based on DCS system artificial intelligence control and with adaptive function in the embodiment of the present invention is:

[0110] The grid-side AGC command and LDC command (AGC command after speed limit) are input into the first subtractor 32 to obtain the deviation between the AGC command and the LDC command. When the load is triggered by a signal and the command deviation is greater than or equal to 2.8MW, it is determined to be a load increase; when the load is triggered by a signal and the command deviation is less than or equal to -2.8MW, it is determined to be a load reduction. When either the load increase or decrease is triggered, it is a variable load state.

[0111] The grid-side AGC command and LDC command (AGC command after speed limit) are input into the first subtractor 32, and the absolute value of the output command deviation value is input into the first function generator 8 to obtain the variable load time threshold corresponding to different command deviations.

[0112] The first function generator 8 described is set to: X: 0, 3, 5, 7, 10, 15, 20, 25, 30, 40, 50; Y: 1, 40, 58, 77, 120, 180, 240, 300, 360, 480, 600 according to engineering experience.

[0113] The variable load time accumulation result of the first time timer 11 is compared, and when the variable load time exceeds the time threshold or is in the non-variable load stage, the time accumulator is reset to stop the variable load time accumulation. The result obtained after the variable load signal is delayed by 2s in the first delay module is used to trigger the first time timer 11 to accumulate time, and the accumulated time calculated by the time accumulator is input into the second function generator 12, and the feedforward action amount in different time periods of the variable load is obtained through historical operation big data analysis and fitting.

[0114] The second function generator 12 described is set to: X: 1, 13, 25, 35, 60, 80, 100, 120, 140, 160, 180; Y: 0.3, 0.3, 1.36, 1.71, 1.42, 1.28, 1.25, 1.1, 1.05, 1, 1 according to data engineering experience values.

[0115] The falling edge of the load-down signal is delayed for 5 seconds and sent to the second selector 31 as a selection judgment signal. The falling edge of the load-up signal is delayed for 5 seconds and sent to the first selector 30 as a selection judgment signal.

[0116] The grid-side AGC command and LDC command (AGC command after speed limit) are input to the third subtractor 26, and the output result command deviation value is respectively input to the fourth function generator 21, the sixth function generator 23, and the eighth function generator 25, and the results are respectively sent to the first multiplier 27, the second multiplier 28, and the third multiplier 29, and then the corresponding LDC command (AGC command after speed limit) is multiplied by the results of the third function generator 20, the fifth function generator 22, and the seventh function generator 24, and then sent to the N end of the first selector 30, the Y end of the first selector 30, and the Y end of the second selector 31. The output of the first selector 30 is sent to the N end of the second selector 31.

[0117] When the load is reduced, the output of the seventh function generator 24 and the eighth function generator 25 are calculated by the third multiplier 29. The seventh function generator 24 is set to X: 100, 120, 140, 160, 170, 180, 200, 240, 260, 300, 350 according to engineering experience; Y: 0.1, 0.1, 0.2, 1, 1, 1, 1, 1, 1, 1. The eighth function generator 25 (25) is set to X: -40, -30, -25, -20, -15, -10, -7, -5, -3.5, -2, -1; Y: -6, -6, -6, -4, -4, -4, -3, -2, -1.5, -0.1, -0.1 according to engineering experience.

[0118] When the load is increased, the output of the fifth function generator 22 and the sixth function generator 23 is calculated by the second multiplier 28. The fifth function generator 22 is set according to engineering experience values ​​as follows: X: 100, 120, 140, 160, 170, 180, 200, 240, 260, 300, 350; Y: 0.5, 0.5, 0.8, 1, 1, 1, 1.2, 1, 0.9, 0.3, 0.3. The sixth function generator 23 (23) is set according to engineering experience values ​​as follows: X: 1, 2, 3.5, 5, 7, 10, 15, 20, 25, 30, 40; Y: 0, 0, 0.1, 1, 1, 4, 5, 6, 6, 6, 6.

[0119] When the load is stable, the output of the third function generator 20 and the fourth function generator 21 are calculated by the first multiplier 27. The third function generator 20 is set to: X: 0, 350; Y: 1, 1 according to engineering experience values. The fourth function generator 21 is set to: X: 0, 350; Y: 0, 0 according to engineering experience values.

[0120] By modifying the function and switching the switch, adaptive correction of the boiler master control feedforward quantity for different variable load amplitudes and different load segments can be achieved.

[0121] The adaptive correction of the boiler master control feedforward quantity of different variable load amplitudes and different load sections output by the second selector 31 is multiplied by the artificial intelligence control variable load boiler feedforward calculation quantity output by the second function generator 12, and then limited by the first limit module 14 (±13t) and sent to the N end of the third selector 16. When CCS is put into operation, the selector outputs the limited calculation quantity, and selects the constant after CCS is exited.

[0122] See also Figure 2 In a second aspect, a variable load boiler master control feedforward method with adaptive function is used in the variable load boiler master control feedforward system with adaptive function described in the first aspect, comprising the following steps:

[0123] S1 load lifting judgment module 1 determines whether the current load should be increased or decreased according to the deviation between the AGC instruction and the LDC instruction given by the power grid;

[0124] Specifically, the grid-side AGC instruction and LDC instruction (AGC instruction after speed limit) are input into the first subtractor 32 to obtain the deviation between the AGC instruction and the LDC instruction, which is used for the subsequent determination of variable load. The output result of the first subtractor 32 and the first constant 34 are input into the first comparator 33 for comparison, and the comparison result and the load are input into the first AND gate 38 for signal comparison and then output to the load increase. The output result of the first subtractor 32 and the second constant 36 are input into the second comparator 35 for comparison, and the output result and the load are input into the second AND gate 37 for signal comparison and then output to the load reduction. The output results of the first AND gate 38 and the second AND gate 37 are input into the first OR gate 39 for the determination of variable load.

[0125] S2 simulates artificial intelligence to control the variable load boiler feedforward module 2 to calculate the variable load time according to the signal triggered by the variable load, and simulates manual calculation of the feedforward amount of the boiler master control in different time periods;

[0126] Specifically, the grid-side AGC instruction and LDC instruction (AGC instruction after speed limit) are input into the second subtractor 6, and the output result instruction deviation value is input into the first absolute value device 7 to take the absolute value and then input into the first function generator 8. The output result and the output result of the first time timer 11 are input into the first comparator 33 together. After the comparison result is output, the output result obtained after the variable load signal is input into the first NOT gate 5 is input into the first OR gate 39 together. The result is output to the RS pin of the first time timer 11, which is used to reset the time accumulation of the first time timer 11. The result obtained after the variable load signal is input into the first delay unit 4 is output to the input pin of the first time timer 11, which is used to trigger the time accumulation of the first time timer 11. The output result of the first time timer 11 is input into the second function generator 12, which is used to calculate the feedforward action amount of the boiler master control in different time periods of the variable load.

[0127] The S3 variable load amplitude and load segment adaptive module 3 calculates the correction of the boiler master control feedforward amount due to the deviation of the AGC instruction and the LDC instruction, and calculates the correction of the boiler master control feedforward amount due to the boiler heat storage in different load segments. After the two are coupled, the boiler master control variable load feedforward amount calculated by the artificial intelligence control variable load boiler feedforward module 2 is corrected according to the weight proportional coefficient to obtain the final variable load boiler master control feedforward amount.

[0128] Specifically, the load reduction signal is input to the first delay 18, and its output is sent to the second selector 31 as a selection judgment signal. The load increase signal is input to the second delay 19, and its output is sent to the first selector 30 as a selection judgment signal. The grid-side AGC instruction and the LDC instruction (AGC instruction after speed limit) are input to the third subtractor 26, and the output result instruction deviation value is respectively input to the fourth function generator 21, the sixth function generator 23, and the eighth function generator 25, and the results are respectively sent to the first multiplier 27, the second multiplier 28, and the third multiplier 29, and the corresponding LDC instruction (AGC instruction after speed limit) is multiplied by the results of the third function generator 20, the fifth function generator 22, and the seventh function generator 24, and then sent to the N end of the first selector 30, the Y end of the first selector 30, and the Y end of the second selector 31. The output of the first selector 30 is sent to the N end of the second selector 31. When the load is reduced, the Y-end input of the second selector 31 is used as the selector output; when the load is increased, the N-end input of the second selector 31 is used as the selector output, and the Y-end input of the first selector 30 is output to the N-end of the second selector 31; when the load is stabilized, the N-end input of the second selector 31 is used as the selector output, and the N-end input of the first selector 30 is output to the N-end of the second selector 31. Through the above switching, when the load is reduced, the calculation result of the third multiplier 29 is output; when the load is increased, the calculation result of the second multiplier 28 is output, and when the load is stabilized, the calculation result of the first multiplier 27 is output. In this way, the adaptive correction of the boiler master control feedforward quantity of different variable load amplitudes and different load sections is realized.

[0129] Beneficial effects:

[0130] 1. The variable load boiler master control feedforward of the present invention simulates manual control, and realizes variable load feedforward quantity closer to the adjustment method of the operating operator in actual process production, which is more practical. Through logical control, the artificial intelligence automatic control idea is realized, which reduces the workload of operators and is more in line with actual needs;

[0131] Second, the present invention can realize differential output of feedforward quantity in different intervals of variable load, which is more conducive to timely action and timely callback of coal quantity than conventional differential feedforward;

[0132] 3. The variable load furnace master control feedforward used in the present invention can perform adaptive adjustment of the feedforward amount according to different variable load amplitudes and different load segments, which is more conducive to the utilization of boiler heat storage and the coal quantity action amount meeting actual needs;

[0133] 4. Based on the above three points, the application scenarios and actual use effects of the feedforward quantity are greatly improved.

[0134] What is disclosed above is only a preferred embodiment of a variable load boiler master control feedforward system and method with adaptive function of the present invention. Of course, it cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A variable load boiler master control feedforward system with adaptive function, characterized in that: It includes a load lifting judgment module, an artificial intelligence control variable load boiler feedforward module and a variable load amplitude and load segment adaptive module, and the load lifting judgment module, the artificial intelligence control variable load boiler feedforward module, and the variable load amplitude and load segment adaptive module are connected in sequence; The load increase or decrease judgment module is used to determine whether the current load should be increased or decreased according to the deviation between the AGC instruction and the LDC instruction given by the power grid; The artificial intelligence-simulated variable load boiler feedforward module is used to calculate the variable load time according to the signal triggered by the variable load, and to simulate the artificial calculation of the feedforward amount of the boiler master control in different time periods; The variable load amplitude and load segment adaptive module is used to calculate the correction of the boiler master control feedforward amount due to the deviation of the AGC instruction and the LDC instruction, and calculate the correction of the boiler master control feedforward amount due to the boiler heat storage in different load segments; after the two are coupled, the boiler master control variable load feedforward amount calculated by the artificial intelligence control variable load boiler feedforward module is corrected according to the weight proportional coefficient to obtain the final variable load boiler master control feedforward amount.

2. The variable load boiler master control feedforward system with adaptive function as claimed in claim 1, characterized in that: The lifting load judgment module includes a first subtractor, a first comparator, a second comparator, a first AND gate, a second AND gate and a first OR gate; the first comparator and the second comparator are both connected to the first subtractor, the first AND gate is connected to the first comparator, the second AND gate is connected to the second comparator, and the first OR gate is connected to the first AND gate and the second AND gate; The first subtractor obtains a deviation between the AGC instruction and the LDC instruction based on the AGC instruction and the LDC instruction on the grid side; The first comparator is used to compare the first constant and the deviation between the AGC instruction and the LDC instruction to obtain a first comparison result and a first load; The second comparator is used to compare the second constant and the deviation between the AGC instruction and the LDC instruction to obtain a second comparison result and a second load; The first AND gate outputs a load increase based on the first comparison result and the first load; the second AND gate, based on the second comparison result and the second load output, reducing the load; The first OR gate determines the load change based on the load increase and the load decrease.

3. The variable load boiler master control feedforward system with adaptive function as claimed in claim 2, characterized in that: The artificial intelligence-controlled variable load boiler feedforward module comprises a first delay unit, a first NOT gate, a second subtractor, a first absolute value device, a first function generator, a third comparator, a second OR gate, a first time timer and a second function generator; the second subtractor, the first absolute value device, the first function generator, the third comparator, the second OR gate and the first NOT gate are connected in sequence, the first delay unit is connected in sequence with the first time timer and the second function generator, and the first timer is connected with the second OR gate and the third comparator respectively; The second subtractor outputs a command deviation value based on the AGC command and the LDC command; The first absolute value device takes an absolute value based on the instruction deviation value; the first function generator outputs a result based on the absolute value; The first time timer is used to output the timing result; The third comparator is used to compare the absolute value result and the timing result, and output the comparison result and the variable load signal; The first NOT gate obtains an output result based on the comparison result and the variable load signal; The second OR gate is used to output the output result to the first time timer to reset the time accumulation; The first delay unit inputs the result into the first time timer to trigger time accumulation based on the variable load signal; The second function generator calculates the boiler main control feedforward action amount in different time periods of variable load based on the output result of the first time timer.

4. The variable load boiler master control feedforward system with adaptive function as claimed in claim 3, characterized in that: The variable load amplitude and load segment adaptive module includes a first delay device, a second delay device, a third subtractor, a third function generator, a fourth function generator, a fifth function generator, a sixth function generator, a seventh function generator, an eighth function generator, a first multiplier, a second multiplier, a third multiplier, a first selector and a second selector; The first delay device outputs a first selection judgment signal based on the load reduction signal; The second delay device outputs a second selection judgment signal based on the load increase signal; The third subtractor outputs an output instruction deviation value based on the grid-side AGC instruction and the LDC instruction; The fourth function generator outputs a result based on the instruction deviation value; The sixth function generator outputs a result based on the instruction deviation value; The eighth function generator outputs a result based on the instruction deviation value; The third function generator outputs a result based on the LDC instruction; The fifth function generator outputs a result based on the LDC instruction; The seventh function generator outputs a result based on the LDC instruction; The first multiplier performs calculation based on the result of the fourth function generator and the result of the third function generator to obtain a first calculation result; The second multiplier performs calculation based on the result of the sixth function generator and the result of the fifth function generator to obtain a second calculation result; The third multiplier performs calculation based on the result of the eighth function generator and the result of the seventh function generator to obtain a third calculation result; the first selector outputting data to the second selector based on the second selection determination signal, the first calculation result and the second calculation result; The second selector outputs the third calculation result when the load is reduced; outputs the second calculation result when the load is increased; and outputs the first calculation result when the load is stabilized.

5. The variable load boiler master control feedforward system with adaptive function as claimed in claim 4, characterized in that: The variable load boiler master control feedforward system with adaptive function also includes a fourth multiplier, a first limiter module, a second NOT gate and a third selector; The fourth multiplier is used to input the output result of the second selector; The first clipping module is used to clip the output result of the second selector and input the clipping result to the third selector; The second NOT gate outputs a triggering judgment signal based on the CCS signal; The third selector outputs a third constant based on the trigger judgment signal.

6. A variable load boiler master control feedforward method with adaptive function, used in the variable load boiler master control feedforward system with adaptive function as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: The load increase and decrease judgment module determines whether the current load should be increased or decreased according to the deviation between the AGC command and the LDC command given by the power grid; The artificial intelligence-controlled variable load boiler feedforward module calculates the variable load time according to the signal triggered by the variable load, and artificially calculates the feedforward amount of the boiler master control in different time periods; The variable load amplitude and load segment adaptive module calculates the deviation between the AGC instruction and the LDC instruction to correct the boiler master control feedforward amount, and calculates the correction of the boiler master control feedforward amount by the boiler heat storage in different load segments. After the two are coupled, the boiler master control variable load feedforward amount calculated by the artificial intelligence control variable load boiler feedforward module is corrected according to the weight proportional coefficient to obtain the final variable load boiler master control feedforward amount.

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