Coal quality correction control system for ultra-supercritical unit

Abstract

The invention discloses a coal quality correction control system for an ultra-supercritical unit. The coal quality correction control system comprises a measurement loop, a reference coal quantity coal quality correction loop, a dynamic coal quantity coal quality correction loop, coal quantity coal quality correction loops from the first layer to the nth layer of coal seams, an addition module I and an addition module II. The measurement loop generates air quantity and boiler heat and inputs the air quantity and the boiler heat into the reference coal quantity and coal quality correction loop and the dynamic coal quantity and coal quality correction loop; the corrected reference coal quantity obtained by the reference coal quantity and coal quality correction loop and the corrected dynamic coal quantity obtained by the dynamic coal quantity and coal quality correction loop are respectively output to an addition module I; the addition module I adds to obtain corrected feed-forward coal quantity, and the corrected feed-forward coal quantity is input to a boiler main controller to correct a coal quantity instruction; each coal seam coal quantity and coal quality correction loop outputs the corrected actual coal quantity of the corresponding layer to an addition module II, and the corrected actual coal quantity is obtained through the addition module II and output to a fuel main controller; and the fuel main controller corrects a coal quantity instruction output by the boiler main controller through the corrected actual coal quantity.

Description

Technical Field

[0001] The invention relates to the field of ultra-supercritical unit control systems, in particular to an ultra-supercritical unit coal quality correction control system. Background Art

[0002] With the rapid development of new energy, the problems of unreasonable power structure and insufficient flexible adjustment capacity of the system have become increasingly prominent, which seriously restricts the consumption of new energy. There is an urgent need for large-capacity ultra-supercritical units to participate in system adjustment as flexible resources, which puts forward requirements for faster, more stable and wider adjustment range of ultra-supercritical units. The coal quality of the unit is one of the main reasons restricting the adjustment and control capacity of the unit.

[0003] With the rise in energy prices, except for a few pit-mouth power stations, most power generation companies, especially those located in the load center, cannot guarantee the quality of power coal. The boiler of a thermal power unit is designed for a specific type of coal. When the coal quality changes, it may cause various operating abnormalities in the boiler, such as coking of the heating surface, overheating of the tube wall, and limitation of the auxiliary machine output. Frequent changes in coal quality and unreasonable blending methods seriously restrict the adjustment ability of the unit, which will lead to increased power consumption of the coal mill, unstable boiler combustion, increased furnace outlet and flue gas temperature, large amount of superheat reheat cooling water, overheating of superheat reheat pipes, and ash accumulation on heating surfaces and air preheating at all levels of the boiler, which will also reduce the safety and economy of the unit operation. It is urgent to calibrate the coal quality of ultra-supercritical units under different operating conditions, match it with the control system structure and parameters, and ensure the safe and stable operation of the unit. Summary of the invention

[0004] In order to solve the deficiencies of the above-mentioned technology, the present invention provides a coal quality correction control system for an ultra-supercritical unit.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: A coal quality correction control system for an ultra-supercritical unit comprises a measurement circuit, a reference coal quantity and coal quality correction circuit, a dynamic coal quantity and coal quality correction circuit, a first to nth coal seam coal quantity and coal quality correction circuit, an addition module 1, an addition module 2, a boiler main controller, and a fuel main controller; the measurement circuit measures the real-time boiler heat, oxygen content, air volume and other parameters of the ultra-supercritical unit, and generates air volume and boiler heat as inputs of the reference coal quantity and coal quality correction circuit, and the boiler heat generated by the measurement circuit also serves as input of the dynamic coal quantity and coal quality correction circuit; The reference coal quantity and coal quality correction loop also inputs the steam flow rate and other parameters of the ultra-supercritical unit, and combines the input steam flow rate, other parameters and the air volume and boiler heat from the measurement loop to obtain the corrected reference coal quantity and output it to the addition module 1; The dynamic coal quantity and coal quality correction loop also inputs the steam flow rate and actual coal quantity of the ultra-supercritical unit, and combines the input steam flow rate, actual coal quantity and boiler heat from the measurement loop to obtain the corrected dynamic coal quantity and output it to the addition module 1; The adding module 1 adds the corrected reference coal quantity and the corrected dynamic coal quantity to obtain the corrected feedforward coal quantity, which is input into the feedforward end of the boiler main controller to correct the coal quantity instruction output by the boiler main controller to the fuel main controller; The coal quantity and coal quality correction loops of the 1st to nth coal seams respectively input the mill inlet primary air flow, mill inlet primary air temperature, mill inlet primary air pressure, mill outlet air-powder mixing temperature, mill ambient temperature, coal quantity of the coal feeder, coal design specific heat capacity, and actual coal quantity of the coal feeder at the corresponding layers in the ultra-supercritical unit, and respectively output the corrected actual coal quantity of the corresponding layers to the addition module 2; The second addition module adds up the corrected actual coal quantities of the corresponding layers output by the coal quantity and coal quality correction circuits of the first to nth coal seams, and obtains the corrected actual coal quantity, which is output to the current value terminal of the fuel main controller; The fuel main controller corrects the coal quantity instruction output by the boiler main controller through the corrected actual coal quantity, thereby obtaining the given value of the coal supply quantity of each layer of coal feeder and outputting it to each layer of coal feeder to control the coal supply quantity of each layer of coal feeder.

[0006] Furthermore, the measurement loop includes an air volume soft measurement module, an oxygen volume soft measurement module, a selection module one, a selection module two, and a boiler heat calculation module; wherein the air volume soft measurement module inputs real-time boiler heat, oxygen volume and other parameters and obtains soft-measured air volume; the selection module one obtains the actual measured air volume and the soft-measured air volume obtained by the air volume soft measurement module, and selects one of them as air volume data to output to the boiler heat calculation module and the reference coal volume and coal quality correction loop; the oxygen volume soft measurement module inputs real-time boiler heat, air volume and other parameters and obtains soft-measured oxygen volume; the selection module two obtains the actual measured oxygen volume and the soft-measured oxygen volume obtained by the oxygen volume soft measurement module, and selects one of them as oxygen volume data to output to the boiler heat calculation module; the boiler heat calculation module also inputs real-time boiler heat and other parameters, and combines the air volume data from the selection module one, the oxygen volume data from the selection module two, the real-time boiler heat, and other parameters to obtain the boiler heat and output it to the reference coal volume and coal quality correction loop and the dynamic coal volume and coal quality correction loop.

[0007] Furthermore, the reference coal quantity and coal quality correction loop includes a boiler heat design value function, a filtering module 1, a reference coal quantity and coal quality correction controller proportional generation function, a reference coal quantity and coal quality correction controller integral generation function, a reference coal quantity and coal quality correction controller, a boiler reference coal quantity design value function, and a multiplication module 1; The boiler heat generated by the measurement loop is input to the filter module 1, and after first-order filtering by the filter module 1, is input to the current value end of the reference coal quantity and coal quality correction controller; The steam flow is input into the boiler heat design value function, and the boiler heat design value is calculated by the boiler heat design value function and input into the set value end of the reference coal quantity and coal quality correction controller; The air volume, boiler heat and other parameters generated by the measurement circuit are input into the reference coal quantity and coal quality correction controller proportional generation function, and the reference coal quantity and coal quality correction controller proportional parameters are generated by the reference coal quantity and coal quality correction controller proportional generation function and output to the reference coal quantity and coal quality correction controller; The air volume and other parameters generated by the measurement circuit are input into the integral generation function of the reference coal quantity and coal quality correction controller, and the integral parameters of the reference coal quantity and coal quality correction controller are generated by the integral generation function of the reference coal quantity and coal quality correction controller and output to the reference coal quantity and coal quality correction controller; The reference coal quantity and coal quality correction controller obtains a reference coal quantity correction coefficient based on input data and outputs it to the multiplication module 1; The steam flow is also input into the boiler reference coal quantity design function, and the reference coal quantity before correction is calculated by the boiler reference coal quantity design function and input into the multiplication module 1; The pre-correction reference coal quantity and the reference coal quantity correction coefficient are multiplied by multiplication module one to generate the post-correction reference coal quantity and output to the addition module one.

[0008] Furthermore, the dynamic coal quantity and coal quality correction loop includes filtering module 2, filtering module 3, division module 1, division module 2, division module 3, broken line function module 3, broken line function module 4, broken line function module 5, broken line function module 6, multiplication module 2, selection module 3, and multiplication module 3; The steam flow rate is passed through the filtering module 2 to generate the steam flow rate after the first-order filtering, the actual coal amount is passed through the filtering module 2 to generate the actual coal amount after the first-order filtering, and the steam flow rate after the first-order filtering and the actual coal amount are divided by the division module 1 to generate the ratio of the actual steam flow rate to the actual coal amount; The steam flow after the first-order filter is also sent to the broken line function module three, and the broken line function module three processes the steam flow after the first-order filter through the boiler reference coal quantity design value function to generate the reference coal quantity design value and send it to the division module two; at the same time, the steam flow after the first-order filter is also sent to the division module two, and the steam flow after the first-order filter and the reference coal quantity design value are divided in the division module two to generate the ratio of the design steam flow to the actual coal quantity; The actual steam flow rate and the actual coal quantity ratio obtained by the division module 1 and the design steam flow rate and the actual coal quantity ratio obtained by the division module 2 are respectively sent to the division module 3. In the division module 3, the actual steam flow rate and the actual coal quantity ratio are divided by the design steam flow rate and the actual coal quantity ratio, and the result is sent to the broken line function module 4; the broken line function module 4 is processed by the boiler dynamic coal quantity correction function to generate a dynamic coal quantity correction coefficient and sent to the multiplication module 2; The boiler heat generated by the measurement loop is first-order filtered by the filter module three and then sent to the broken line function module five, in which it is processed by the boiler heat correction coefficient function to generate a boiler heat correction coefficient and sent to the multiplication module two; The steam flow after the first-order filtering is also sent to the broken line function module six, in which the broken line function module six is ​​processed by the steam flow correction coefficient function to generate a steam flow correction coefficient and sent to the multiplication module two; In the multiplication module 2, the dynamic coal quantity correction coefficient, the boiler heat correction coefficient, and the steam flow correction coefficient are multiplied to generate a corrected dynamic coal quantity correction coefficient and send it to the selection module 3; The corrected dynamic coal quantity correction coefficient realizes the self-maintaining function during the load change process by selecting module three. When the load does not change, module three is selected to output the current corrected dynamic coal quantity correction coefficient. Otherwise, module three is selected to output the corrected dynamic coal quantity correction coefficient before the load change. The corrected dynamic coal quantity correction coefficient is multiplied by the dynamic coal quantity after selecting module three to generate the corrected dynamic coal quantity and send it to addition module one.

[0009] Furthermore, the coal quantity and coal quality correction circuit of each coal seam includes filtering module 4, specific heat capacity calculation module 1, subtraction module 1, subtraction module 2, filtering module 5, multiplication module 4, multiplication module 5, division module 4, division module 5, broken line function module 7, and multiplication module 6; The primary air volume at the inlet of each layer of coal mill is input into the filter module 4, and then sent to the multiplication module 4 after the first-order filtering of the filter module 4; The primary air temperature and primary air pressure at each mill inlet are input into the specific heat capacity calculation module 1, and the specific heat capacity of the primary air at the mill inlet of the corresponding layer is calculated by the specific heat capacity calculation module 1 and sent to the multiplication module 4; The primary air temperature at each mill inlet and the air-powder mixed temperature at the mill outlet are input into the subtraction module 1. The primary air temperature at each mill inlet is subtracted from the air-powder mixed temperature at the corresponding mill outlet by the subtraction module 1 to generate the corresponding mill inlet and outlet air temperature difference and input it into the multiplication module 4. In the multiplication module 4, the primary air volume at the inlet of each layer of coal mill, the specific heat capacity of the primary air at the inlet of each layer of mill, and the temperature difference of the inlet and outlet air of each layer of mill are multiplied to obtain the energy carried by the primary air at the inlet of each layer of mill and input it into the division module 4; The air-powder mixed temperature at each mill outlet and the mill environment temperature are input into the subtraction module 2. The air-powder mixed temperature at each mill outlet is subtracted from the corresponding mill environment temperature using the subtraction module 2 to generate the coal temperature difference at the corresponding mill outlet and input into the multiplication module 5. The coal quantity of each layer coal feeder is input to the filter module 5, and after the first-order filtering of the filter module 5, it is output to the multiplication module 5; In the multiplication module five, the coal quantity of each layer of coal feeder is multiplied by the temperature difference of coal at the mill inlet and outlet, and the result is output to the division module four, and the result is divided by the energy carried by the primary air at the mill inlet of each layer to obtain the current specific heat capacity of the coal seam, and the result is input to the division module five; The designed specific heat capacity of each coal layer is input into the division module 5. In the division module 5, the current specific heat capacity of the coal layer is divided by the designed specific heat capacity of the corresponding coal layer. The result is then input into the broken line function module 7. In the broken line function module 7, the corresponding coal quality correction coefficient is generated by the corresponding coal quantity and quality correction function and input into the multiplication module 6. The actual amount of coal in each layer of coal feeder is input into multiplication module six, in which the coal quality correction coefficient of each layer is multiplied by the actual amount of coal in the corresponding layer of coal feeder to generate the corrected amount of coal in each layer of coal feeder and output it to addition module two.

[0010] The invention discloses a coal quality correction control system and control method for an ultra-supercritical unit. Compared with the prior art, the invention has the following beneficial effects: by utilizing the combination of existing functional modules, the coal quality correction of the ultra-supercritical unit's reference coal quantity, dynamic coal quantity, and coal quantity in the coal seam is realized without affecting the operation and operation of the unit, and the coal quality correction of the unit's steady-state, dynamic, and quasi-steady-state processes is realized under the normal operation of the ultra-supercritical unit. The safety and stability of the ultra-supercritical unit are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a principle block diagram of a coal quality correction control system for an ultra-supercritical unit in this embodiment.

[0012] Figure 2 It is a principle block diagram of the measurement circuit of this embodiment.

[0013] Figure 3 It is a principle block diagram of the reference coal quantity and coal quality correction circuit of this embodiment.

[0014] Figure 4 It is a principle block diagram of the dynamic coal quantity and quality correction circuit of this embodiment.

[0015] Figure 5 It is the principle block diagram of the coal seam coal quantity and coal quality correction circuit. DETAILED DESCRIPTION

[0016] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0017] like Figure 1 As shown, this embodiment discloses a coal quality correction control system for an ultra-supercritical unit, including a measurement circuit, a reference coal quantity and coal quality correction circuit, a dynamic coal quantity and coal quality correction circuit, a 1st to nth coal seam coal quantity and coal quality correction circuit, an addition module 1, an addition module 2, a boiler main controller, and a fuel main controller.

[0018] In this embodiment, the input quantity (air volume, boiler heat) of the reference coal quantity and coal quality correction loop and the input quantity (boiler heat) of the dynamic coal quantity and coal quality correction loop are generated through the measurement loop output, and the corrected reference coal quantity is further generated through the reference coal quantity and coal quality correction loop, and the corrected dynamic coal quantity is generated through the dynamic coal quantity correction loop. The corrected reference coal quantity and the corrected dynamic coal quantity are superimposed to generate the corrected feedforward coal quantity, which acts on the feedforward end of the boiler master controller in the boiler following mode. The coal seam coal quantity and coal quality correction loop is used to generate the corrected coal quantity of the coal feeder for different coal seams, and the corrected actual coal quantity is superimposed to act on the current value end of the fuel master controller. In this way, the coal quality correction of the reference coal quantity, dynamic coal quantity, and coal seam coal quantity of the ultra-supercritical unit is realized, and the unit's steady-state, dynamic, and quasi-steady-state coal quality correction is realized under the normal operating conditions of the ultra-supercritical unit, ensuring the safe, stable and economical operation of the unit under different coal qualities and different blending methods. The specific instructions are as follows: (1) If Figure 2 As shown, in this embodiment, the measurement circuit measures the real-time boiler heat, oxygen content, air volume and other parameters of the ultra-supercritical unit, and generates air volume and boiler heat as inputs of the reference coal quantity and coal quality correction circuit. The boiler heat generated by the measurement circuit is also used as input of the dynamic coal quantity and coal quality correction circuit. Among them, other parameters include load, coal quantity, and fan current.

[0019] Specifically, the measurement loop includes an air volume soft measurement module, an oxygen volume soft measurement module, a selection module 1, a selection module 2, and a boiler heat calculation module.

[0020] Among them, the air volume soft measurement module inputs the real-time boiler heat, oxygen content and other parameters and obtains the soft measurement air volume; the selection module 1 obtains the actual measured air volume and the soft measurement air volume obtained by the air volume soft measurement module. If the measured air volume fails, the air volume data output by the selection module 1 is the soft measurement air volume, otherwise the air volume data output by the selection module 1 is the measured air volume. Therefore, the selection module 1 selects one of them as the air volume data output to the boiler heat calculation module and the reference coal quantity and coal quality correction circuit.

[0021] The oxygen soft measurement module inputs the real-time boiler heat, air volume and other parameters and obtains the soft measurement oxygen; the selection module 2 obtains the actual measured oxygen and the soft measurement oxygen obtained by the oxygen soft measurement module. If the measured oxygen fails, the oxygen data output by the selection module 2 is the soft measurement oxygen, otherwise the oxygen data output by the selection module 2 is the measured oxygen. Thus, the selection module 2 selects one of them as the oxygen data output to the boiler heat calculation module.

[0022] The boiler heat calculation module also inputs real-time boiler heat and other parameters (including load, coal quantity, and fan current), and combines the air volume data from selection module one, the oxygen content data from selection module two, the real-time boiler heat, and other parameters to obtain the boiler heat and output it to the reference coal quantity and coal quality correction circuit and the dynamic coal quantity and coal quality correction circuit.

[0023] (2) If Figure 3 As shown, in this embodiment, the reference coal quantity and coal quality correction loop also inputs the steam flow rate and other parameters (including load, coal quantity, and fan current) of the ultra-supercritical unit, and combines the input steam flow rate, other parameters, and the air volume and boiler heat from the measurement loop to obtain the corrected reference coal quantity and output it to addition module one.

[0024] Specifically, the reference coal quantity and coal quality correction loop includes a broken line function module 1 (used to realize the boiler heat design value function), a filtering module 1, a reference coal quantity and coal quality correction controller proportional generation function, a reference coal quantity and coal quality correction controller integral generation function, a reference coal quantity and coal quality correction controller, a broken line function module 2 (used to realize the boiler reference coal quantity design value function), and a multiplication module 1.

[0025] The boiler heat generated by the measurement loop is input to the filter module 1, and is input to the current value end of the reference coal quantity and coal quality correction controller after first-order filtering by the filter module 1.

[0026] The steam flow is input into the broken line function module 1, and the boiler heat design value is calculated by the boiler heat design value function of the broken line function module 1 and input into the set value end of the reference coal quantity and coal quality correction controller.

[0027] The air volume, boiler heat and other parameters generated by the measurement circuit are input into the proportional generation function of the benchmark coal quantity and coal quality correction controller, and the proportional parameters of the benchmark coal quantity and coal quality correction controller are generated by the proportional generation function and output to the benchmark coal quantity and coal quality correction controller.

[0028] The air volume and other parameters generated by the measurement circuit are input into the integral generation function of the reference coal quantity and coal quality correction controller, and the integral parameters of the reference coal quantity and coal quality correction controller are generated by the integral generation function and output to the reference coal quantity and coal quality correction controller.

[0029] The output upper limit value of the reference coal quantity and coal quality correction controller is 1.4, and the output lower limit value is 0.6. The reference coal quantity and coal quality correction controller obtains the reference coal quantity correction coefficient based on the input data and outputs it to the multiplication module one.

[0030] The steam flow is also input into the broken line function module 2, and the boiler reference coal quantity design function in the broken line function module 2 is used to calculate the reference coal quantity before correction and input into the multiplication module 1.

[0031] The pre-correction reference coal quantity and the reference coal quantity correction coefficient are multiplied by multiplication module one to generate the post-correction reference coal quantity and output to the addition module one.

[0032] (3) If Figure 4 As shown, in this embodiment, the dynamic coal quantity and coal quality correction loop also inputs the steam flow and actual coal quantity of the ultra-supercritical unit, and combines the input steam flow, actual coal quantity and boiler heat from the measurement loop to obtain the corrected dynamic coal quantity and output it to addition module one.

[0033] Specifically, the dynamic coal quantity and coal quality correction loop includes filtering module 2, filtering module 3, division module 1, division module 2, division module 3, broken line function module 3, broken line function module 4, broken line function module 5, broken line function module 6, multiplication module 2, selection module 3, and multiplication module 3.

[0034] The steam flow passes through filtering module two to generate a first-order filtered steam flow, and the actual coal quantity passes through filtering module two to generate a first-order filtered actual coal quantity. The first-order filtered steam flow and the actual coal quantity are divided by division module one to generate the ratio of the actual steam flow to the actual coal quantity.

[0035] The steam flow after the first-order filter is also sent to the broken line function module three, and the broken line function module three processes the steam flow after the first-order filter through the boiler benchmark coal quantity design value function to generate the benchmark coal quantity design value and send it to the division module two; at the same time, the steam flow after the first-order filter is also sent to the division module two, and the steam flow after the first-order filter and the benchmark coal quantity design value are divided in the division module two to generate the ratio of the design steam flow to the actual coal quantity.

[0036] The actual steam flow and actual coal quantity ratio obtained by the division module one and the design steam flow and actual coal quantity ratio obtained by the division module two are respectively sent to the division module three. In the division module three, the actual steam flow and actual coal quantity ratio is divided by the design steam flow and actual coal quantity ratio, and the result is sent to the broken line function module four; the broken line function module four is processed by the boiler dynamic coal quantity correction function to generate a dynamic coal quantity correction coefficient and sent to the multiplication module two.

[0037] The boiler heat generated by the measurement loop is first-order filtered by the filtering module three and then sent to the broken line function module five. In the broken line function module five, it is processed by the boiler heat correction coefficient function to generate a boiler heat correction coefficient and sent to the multiplication module two.

[0038] The steam flow after the first-order filtering is also sent to the broken line function module six, in which the broken line function module six is ​​processed by the steam flow correction coefficient function to generate a steam flow correction coefficient and sent to the multiplication module two; In the multiplication module two, the dynamic coal quantity correction coefficient, the boiler heat correction coefficient, and the steam flow correction coefficient are multiplied to generate a corrected dynamic coal quantity correction coefficient and send it to the selection module three.

[0039] The corrected dynamic coal quantity correction coefficient realizes the self-maintaining function during the load change process by selecting module three. When the load does not change, module three is selected to output the current corrected dynamic coal quantity correction coefficient. Otherwise, module three is selected to output the corrected dynamic coal quantity correction coefficient before the load change. The corrected dynamic coal quantity correction coefficient is multiplied by the dynamic coal quantity after selecting module three to generate the corrected dynamic coal quantity and send it to addition module one.

[0040] (4) If Figure 1 As shown, in this embodiment, the addition module 1 adds the corrected reference coal quantity and the corrected dynamic coal quantity to obtain the corrected feedforward coal quantity, which is input to the feedforward end of the boiler main controller to correct the coal quantity instruction output by the boiler main controller to the fuel main controller.

[0041] (5) If Figure 5 As shown, in this embodiment, the coal quantity and coal quality correction circuit structures of the 1st to nth coal seams are the same, and the coal quantity and coal quality correction circuits of the 1st to nth coal seams respectively input the mill inlet primary air flow rate, mill inlet primary air temperature, mill inlet primary air pressure, mill outlet air-powder mixing temperature, mill ambient temperature, coal quantity of the coal feeder, coal design specific heat capacity, and actual coal quantity of the coal feeder at the corresponding layer in the ultra-supercritical unit, and respectively output the corrected actual coal quantity of the corresponding layer to the addition module 2.

[0042] Specifically, taking the coal quantity and coal quality correction circuit of the nth coal seam as an example, the coal quantity and coal quality correction circuit of the nth coal seam includes filtering module four, specific heat capacity calculation module one, subtraction module one, subtraction module two, filtering module five, multiplication module four, multiplication module five, division module four, division module five, broken line function module seven, and multiplication module six.

[0043] The primary air volume at the inlet of the n-th layer coal mill is input into the filter module four, and is sent to the multiplication module four after the first-order filtering of the filter module four.

[0044] The primary air temperature and primary air pressure at the n-th mill inlet are input into the specific heat capacity calculation module one, and the specific heat capacity of the primary air at the n-th mill inlet is calculated by the specific heat capacity calculation module one and sent to the multiplication module four.

[0045] The primary air temperature at the n-th layer mill inlet and the air-powder mixed temperature at the mill outlet are input into subtraction module one. The primary air temperature at the n-th layer mill inlet is subtracted from the air-powder mixed temperature at the n-th layer mill outlet by subtraction module one to generate the n-th layer mill inlet and outlet air temperature difference and send it to multiplication module four.

[0046] In the multiplication module four, the primary air volume at the inlet of the n-th layer coal mill, the specific heat capacity of the primary air at the inlet of the n-th layer mill, and the temperature difference between the inlet and outlet air of the n-th layer mill are multiplied to obtain the energy carried by the primary air of the n-th layer coal mill and input it into the division module four.

[0047] The air-powder mixed temperature at the n-th mill outlet and the mill ambient temperature are input into subtraction module two. The air-powder mixed temperature at the n-th mill outlet is subtracted from the n-th mill ambient temperature using subtraction module two to generate the coal temperature difference at the n-th mill inlet and outlet and send it to multiplication module five.

[0048] The coal quantity of the coal feeder at the nth layer is input to the filter module five, and is output to the multiplication module five after first-order filtering by the filter module five.

[0049] In multiplication module five, the coal quantity of the nth layer coal feeder is multiplied by the temperature difference of the coal at the mill inlet and outlet and output to division module four, divided by the energy carried by the primary wind at each mill inlet to obtain the current specific heat capacity of the coal seam and input to division module five.

[0050] The designed specific heat capacity of the nth layer of coal is input into the division module five. In the division module five, the current specific heat capacity of the nth layer of coal is divided by the designed specific heat capacity of the corresponding layer of coal. The result is then input into the broken line function module seven. In the broken line function module seven, the nth layer of coal quality correction coefficient is generated by the nth layer coal quantity and coal quality correction function and input into the multiplication module six.

[0051] The actual amount of coal in the n-th layer coal feeder is input into multiplication module six, in which the n-th layer coal quality correction coefficient is multiplied by the actual amount of coal in the n-th layer coal feeder to generate the corrected amount of coal in the n-th layer coal feeder and output it to addition module two.

[0052] (6) Figure 1 As shown, the addition module 2 superimposes the corrected actual coal quantities of the corresponding layers output by the coal quantity and coal quality correction circuits of the 1st to the nth coal seams, and obtains the corrected actual coal quantity, which is output to the current value end of the fuel main controller; (7) Figure 1 As shown, the fuel main controller corrects the coal quantity instruction output by the boiler main controller through the corrected actual coal quantity, thereby obtaining the given value of the coal supply quantity of each layer of coal feeder and outputting it to each layer of coal feeder to control the coal supply quantity of each layer of coal feeder.

[0053] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. The embodiments described in the present invention are merely descriptions of the preferred embodiments of the present invention, and do not limit the concept and scope of the present invention. The various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction, and such combinations should also be regarded as the contents disclosed in the present disclosure as long as they do not violate the concept of the present invention. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0054] The present invention is not limited to the specific details of the above-mentioned embodiments. Within the technical concept of the present invention and without departing from the design concept of the present invention, various modifications and improvements made to the technical solution of the present invention by technical personnel in this field should fall within the protection scope of the present invention. The technical contents for which protection is sought in the present invention have been fully recorded in the claims.

Claims

1. A coal quality correction control system for an ultra-supercritical unit, characterized in that: It includes a measurement circuit, a reference coal quantity and coal quality correction circuit, a dynamic coal quantity and coal quality correction circuit, a coal quantity and coal quality correction circuit for the first to nth coal seams, an addition module 1, an addition module 2, a boiler main controller, and a fuel main controller; the measurement circuit measures the real-time boiler heat, oxygen content, air volume and other parameters of the ultra-supercritical unit, and generates air volume and boiler heat as inputs of the reference coal quantity and coal quality correction circuit, and the boiler heat generated by the measurement circuit also serves as input of the dynamic coal quantity and coal quality correction circuit; The reference coal quantity and coal quality correction loop also inputs the steam flow rate and other parameters of the ultra-supercritical unit, and combines the input steam flow rate, other parameters and the air volume and boiler heat from the measurement loop to obtain the corrected reference coal quantity and output it to the addition module 1; The dynamic coal quantity and coal quality correction loop also inputs the steam flow rate and actual coal quantity of the ultra-supercritical unit, and combines the input steam flow rate, actual coal quantity and boiler heat from the measurement loop to obtain the corrected dynamic coal quantity and output it to the addition module 1; The adding module 1 adds the corrected reference coal quantity and the corrected dynamic coal quantity to obtain the corrected feedforward coal quantity, which is input into the feedforward end of the boiler main controller to correct the coal quantity instruction output by the boiler main controller to the fuel main controller; The coal quantity and coal quality correction loops of the 1st to nth coal seams respectively input the mill inlet primary air flow, mill inlet primary air temperature, mill inlet primary air pressure, mill outlet air-powder mixing temperature, mill ambient temperature, coal quantity of the coal feeder, coal design specific heat capacity, and actual coal quantity of the coal feeder at the corresponding layers in the ultra-supercritical unit, and respectively output the corrected actual coal quantity of the corresponding layers to the addition module 2; The second addition module adds up the corrected actual coal quantities of the corresponding layers output by the coal quantity and coal quality correction circuits of the first to nth coal seams, and obtains the corrected actual coal quantity, which is output to the current value terminal of the fuel main controller; The fuel main controller corrects the coal quantity instruction output by the boiler main controller through the corrected actual coal quantity, thereby obtaining the given value of the coal supply quantity of each layer of coal feeder and outputting it to each layer of coal feeder to control the coal supply quantity of each layer of coal feeder.

2. The coal quality correction and control system for an ultra-supercritical unit according to claim 1, characterized in that: The measurement circuit includes an air volume soft measurement module, an oxygen volume soft measurement module, a selection module 1, a selection module 2, and a boiler heat calculation module; wherein the air volume soft measurement module inputs real-time boiler heat, oxygen volume and other parameters and obtains soft-measured air volume; the selection module 1 obtains the actual measured air volume and the soft-measured air volume obtained by the air volume soft measurement module, and selects one of them as air volume data to output to the boiler heat calculation module and the reference coal quantity and coal quality correction circuit; the oxygen volume soft measurement module inputs real-time boiler heat, air volume and other parameters and obtains soft-measured oxygen volume; the selection module 2 obtains the actual measured oxygen volume and the soft-measured oxygen volume obtained by the oxygen volume soft measurement module, and selects one of them as oxygen volume data to output to the boiler heat calculation module; the boiler heat calculation module also inputs real-time boiler heat and other parameters, and combines the air volume data from the selection module 1, the oxygen volume data from the selection module 2, the real-time boiler heat, and other parameters to obtain the boiler heat and output it to the reference coal quantity and coal quality correction circuit and the dynamic coal quantity and coal quality correction circuit.

3. The coal quality correction and control system for an ultra-supercritical unit according to claim 1, characterized in that: The reference coal quantity and coal quality correction loop includes a boiler heat design value function, a filtering module 1, a reference coal quantity and coal quality correction controller proportional generation function, a reference coal quantity and coal quality correction controller integral generation function, a reference coal quantity and coal quality correction controller, a boiler reference coal quantity design value function, and a multiplication module 1; The boiler heat generated by the measurement loop is input to the filter module 1, and after first-order filtering by the filter module 1, is input to the current value end of the reference coal quantity and coal quality correction controller; The steam flow is input into the boiler heat design value function, and the boiler heat design value is calculated by the boiler heat design value function and input into the set value end of the reference coal quantity and coal quality correction controller; The air volume, boiler heat and other parameters generated by the measurement circuit are input into the reference coal quantity and coal quality correction controller proportional generation function, and the reference coal quantity and coal quality correction controller proportional parameters are generated by the reference coal quantity and coal quality correction controller proportional generation function and output to the reference coal quantity and coal quality correction controller; The air volume and other parameters generated by the measurement circuit are input into the integral generation function of the reference coal quantity and coal quality correction controller, and the integral parameters of the reference coal quantity and coal quality correction controller are generated by the integral generation function of the reference coal quantity and coal quality correction controller and output to the reference coal quantity and coal quality correction controller; The reference coal quantity and coal quality correction controller obtains a reference coal quantity correction coefficient based on input data and outputs it to the multiplication module 1; The steam flow is also input into the boiler reference coal quantity design function, and the reference coal quantity before correction is calculated by the boiler reference coal quantity design function and input into the multiplication module 1; The pre-correction reference coal quantity and the reference coal quantity correction coefficient are multiplied by multiplication module one to generate the post-correction reference coal quantity and output to the addition module one.

4. The coal quality correction and control system for an ultra-supercritical unit according to claim 1, characterized in that: The dynamic coal quantity and coal quality correction loop includes filtering module 2, filtering module 3, division module 1, division module 2, division module 3, broken line function module 3, broken line function module 4, broken line function module 5, broken line function module 6, multiplication module 2, selection module 3, and multiplication module 3; The steam flow rate is passed through the filtering module 2 to generate the steam flow rate after the first-order filtering, the actual coal amount is passed through the filtering module 2 to generate the actual coal amount after the first-order filtering, and the steam flow rate after the first-order filtering and the actual coal amount are divided by the division module 1 to generate the ratio of the actual steam flow rate to the actual coal amount; The steam flow after the first-order filter is also sent to the broken line function module three, and the broken line function module three processes the steam flow after the first-order filter through the boiler reference coal quantity design value function to generate the reference coal quantity design value and send it to the division module two; at the same time, the steam flow after the first-order filter is also sent to the division module two, and the steam flow after the first-order filter and the reference coal quantity design value are divided in the division module two to generate the ratio of the design steam flow to the actual coal quantity; The actual steam flow rate and the actual coal quantity ratio obtained by the division module 1 and the design steam flow rate and the actual coal quantity ratio obtained by the division module 2 are respectively sent to the division module 3. In the division module 3, the actual steam flow rate and the actual coal quantity ratio are divided by the design steam flow rate and the actual coal quantity ratio, and the result is sent to the broken line function module 4; the broken line function module 4 is processed by the boiler dynamic coal quantity correction function to generate a dynamic coal quantity correction coefficient and sent to the multiplication module 2; The boiler heat generated by the measurement loop is first-order filtered by the filter module three and then sent to the broken line function module five, in which it is processed by the boiler heat correction coefficient function to generate a boiler heat correction coefficient and sent to the multiplication module two; The steam flow after the first-order filtering is also sent to the broken line function module six, in which the broken line function module six is ​​processed by the steam flow correction coefficient function to generate a steam flow correction coefficient and sent to the multiplication module two; In the multiplication module 2, the dynamic coal quantity correction coefficient, the boiler heat correction coefficient, and the steam flow correction coefficient are multiplied to generate a corrected dynamic coal quantity correction coefficient and send it to the selection module 3; The corrected dynamic coal quantity correction coefficient realizes the self-maintaining function during the load change process by selecting module three. When the load does not change, module three is selected to output the current corrected dynamic coal quantity correction coefficient. Otherwise, module three is selected to output the corrected dynamic coal quantity correction coefficient before the load change. The corrected dynamic coal quantity correction coefficient is multiplied by the dynamic coal quantity after selecting module three to generate the corrected dynamic coal quantity and send it to addition module one.

5. The coal quality correction and control system for an ultra-supercritical unit according to claim 1, characterized in that: The coal quantity and coal quality correction circuit of each coal seam includes filtering module 4, specific heat capacity calculation module 1, subtraction module 1, subtraction module 2, filtering module 5, multiplication module 4, multiplication module 5, division module 4, division module 5, broken line function module 7, and multiplication module 6; The primary air volume at the inlet of each layer of coal mill is input into the filter module 4, and then sent to the multiplication module 4 after the first-order filtering of the filter module 4; The primary air temperature and primary air pressure at each mill inlet are input into the specific heat capacity calculation module 1, and the specific heat capacity of the primary air at the mill inlet of the corresponding layer is calculated by the specific heat capacity calculation module 1 and sent to the multiplication module 4; The primary air temperature at each mill inlet and the air-powder mixed temperature at the mill outlet are input into the subtraction module 1. The primary air temperature at each mill inlet is subtracted from the air-powder mixed temperature at the corresponding mill outlet by the subtraction module 1 to generate the corresponding mill inlet and outlet air temperature difference and input it into the multiplication module 4. In the multiplication module 4, the primary air volume at the inlet of each layer of coal mill, the specific heat capacity of the primary air at the inlet of each layer of mill, and the temperature difference of the inlet and outlet air of each layer of mill are multiplied to obtain the energy carried by the primary air at the inlet of each layer of mill and input it into the division module 4; The air-powder mixed temperature at each mill outlet and the mill environment temperature are input into the subtraction module 2. The air-powder mixed temperature at each mill outlet is subtracted from the corresponding mill environment temperature using the subtraction module 2 to generate the coal temperature difference at the corresponding mill outlet and input into the multiplication module 5. The coal quantity of each layer coal feeder is input to the filter module 5, and after the first-order filtering of the filter module 5, it is output to the multiplication module 5; In the multiplication module five, the coal quantity of each layer of coal feeder is multiplied by the temperature difference of coal at the mill inlet and outlet, and the result is output to the division module four, and the result is divided by the energy carried by the primary air at the mill inlet of each layer to obtain the current specific heat capacity of the coal seam, and the result is input to the division module five; The designed specific heat capacity of each coal layer is input into the division module 5. In the division module 5, the current specific heat capacity of the coal layer is divided by the designed specific heat capacity of the corresponding coal layer. The result is then input into the broken line function module 7. In the broken line function module 7, the corresponding coal quality correction coefficient is generated by the corresponding coal quantity and quality correction function and input into the multiplication module 6. The actual amount of coal in each layer of coal feeder is input into multiplication module six, in which the coal quality correction coefficient of each layer is multiplied by the actual amount of coal in the corresponding layer of coal feeder to generate the corrected amount of coal in each layer of coal feeder and output it to addition module two.

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