CN118242641A

CN118242641A - Control method of circulating fluidized bed boiler system

Info

Publication number: CN118242641A
Application number: CN202410507689.0A
Authority: CN
Inventors: 赵海权; 王启智; 李伟; 李军; 门小勇; 张毅; 朱建忠; 连建国; 强军; 王波; 佟亮亮; 赵振华
Original assignee: National Energy Group Ningxia Coal Industry Co Ltd
Current assignee: National Energy Group Ningxia Coal Industry Co Ltd
Filing date: 2024-04-25
Publication date: 2024-06-25

Abstract

The application provides a control method of a circulating fluidized bed boiler system, the circulating fluidized bed boiler system comprises a hearth and a coal supply system connected with the hearth, the method comprises the following steps: according to the first average coal feeding amount, the first average boiler load, the second average coal feeding amount and the second average boiler load, calculating to obtain initial coal feeding amount of the coal feeding system, and determining the coal feeding amount of the coal feeding system as the initial coal feeding amount; correcting the initial coal feeding amount according to the current oxygen content of the hearth and the current negative pressure of the hearth to obtain corrected coal feeding amount; establishing an objective function according to at least the operation parameters of the circulating fluidized bed boiler system and the corrected coal feeding amount, and adjusting the operation parameters to maximize the function value of the objective function; and determining the operation parameter corresponding to the maximum value of the function value as a target operation parameter, and controlling the circulating fluidized bed boiler system to operate according to the target operation parameter. The method solves the problem of low efficiency and stability of the circulating fluidized bed boiler system in the prior art.

Description

Control method of circulating fluidized bed boiler system

Technical Field

The application relates to the field of control of circulating fluidized bed boilers, in particular to a control method of a circulating fluidized bed boiler system, a control device of the circulating fluidized bed boiler system and an electronic device.

Background

The circulating fluidized bed boiler can realize single-loop automatic control of operation, however, interaction between the interiors of the circulating fluidized bed boiler system and larger feedback lag can lead to coal-feeding over-oxygen combustion or under-oxygen combustion, thereby increasing the loss of incomplete chemical combustion and reducing the conversion efficiency and stability of the boiler.

Therefore, a method is needed to solve the problem of low efficiency and stability of the circulating fluidized bed boiler system.

Disclosure of Invention

The application mainly aims to provide a control method of a circulating fluidized bed boiler system, a control device of the circulating fluidized bed boiler system and an electronic device, so as to at least solve the problem of low efficiency and stability of the circulating fluidized bed boiler system in the prior art.

According to an aspect of the present application, there is provided a control method of a circulating fluidized bed boiler system including a furnace and a coal supply system connected to the furnace, wherein the method includes: acquiring a first average coal feeding amount, a first average boiler load, a second average coal feeding amount and a second average boiler load, wherein the first average coal feeding amount is the average coal feeding amount of the coal feeding system in a first time period before the current moment, the first average boiler load is the average boiler load of the circulating fluidized bed boiler system in the first time period, the second average coal feeding amount is the average coal feeding amount of the coal feeding system in a second time period after the current moment, and the second average boiler load is the average boiler load of the circulating fluidized bed boiler system in the second time period; according to the first average coal feeding amount, the first average boiler load, the second average coal feeding amount and the second average boiler load, calculating to obtain initial coal feeding amount of the coal feeding system, and determining the coal feeding amount of the coal feeding system as the initial coal feeding amount; correcting the initial coal feeding amount according to the current oxygen content of the hearth and the current negative pressure of the hearth to obtain corrected coal feeding amount, wherein the current oxygen content is the oxygen content of the hearth at the current moment, and the current negative pressure is the difference value between the pressure of the hearth at the current moment and the pressure outside the hearth; establishing an objective function according to at least the operation parameters of the circulating fluidized bed boiler system and the corrected coal feeding amount, and adjusting the operation parameters to maximize the function value of the objective function, wherein the operation parameters at least comprise the boiler load of the circulating fluidized bed boiler system, the temperature of the circulating fluidized bed boiler system and the steam negative pressure of the circulating fluidized bed boiler system, and the objective function is used for representing the operation efficiency of the circulating fluidized bed boiler system; and determining the operation parameter corresponding to the maximum value of the function value as a target operation parameter, and controlling the circulating fluidized bed boiler system to operate according to the target operation parameter.

Optionally, the circulating fluidized bed boiler system further comprises a fume system connected with the furnace, the fume system comprises a fume inducing device and a blower, wherein the method further comprises: calculating a difference value between a first coal feeding amount and a second coal feeding amount to obtain a coal feeding variation amount, wherein the first coal feeding amount is the coal feeding amount of the coal feeding system in the first time period, and the second coal feeding amount is the coal feeding amount of the coal feeding system in the second time period; determining a current air-fuel ratio according to the current oxygen content and a mapping relation, wherein the mapping relation is used for representing the mapping relation between the oxygen content of the hearth and the air-fuel ratio of the hearth; calculating to obtain an air supply variable quantity according to the current air-fuel ratio and the coal supply variable quantity, and adjusting the air supply quantity of the air supply device according to the air supply variable quantity; and calculating the induced air variable quantity according to the coal feeding variable quantity and the air supply variable quantity, and adjusting the induced air quantity of the induced air device according to the induced air variable quantity.

Optionally, according to the current air-fuel ratio and the coal supply variation, calculating an air supply variation includes: and calculating the product of the current air-fuel ratio and the coal supply variation to obtain the air supply variation.

Optionally, according to the coal feeding variable quantity and the air supply variable quantity, calculating to obtain an induced air variable quantity, including: and calculating the sum of the coal feeding variable quantity and the air supply variable quantity to obtain the induced air variable quantity.

Optionally, calculating the initial coal feeding amount of the coal feeding system according to the first average coal feeding amount, the first average boiler load, the second average coal feeding amount and the second average boiler load comprises the following steps: calculating the ratio of the first average coal feeding amount to the first average boiler load to obtain a first ratio; calculating the ratio of the second average coal feeding amount to the first average boiler load to obtain a second ratio; and calculating the ratio of the second ratio to the first ratio to obtain the initial coal feeding amount.

Optionally, correcting the initial coal feeding amount according to the current oxygen content of the hearth and the current negative pressure of the hearth to obtain a corrected coal feeding amount, including: calculating to obtain a first preliminary coal feeding amount M1 according to a formula m1=k1× (O-OL) ×t1, wherein k1 is a first predetermined coefficient, O is the current oxygen content, OL is a preset minimum oxygen content of the furnace chamber, and T1 is a duration time for which the current oxygen content is lower than the minimum oxygen content; calculating to obtain a second preliminary coal feeding amount M2 according to a formula M2=k2× (Y-YH) x T2, wherein k2 is a second predetermined coefficient, Y is the current negative pressure, YH is a preset maximum negative pressure of the hearth, and T2 is the duration time length that the current negative pressure is greater than the maximum negative pressure; and calculating the average value of the first preparation coal feeding amount and the second preparation coal feeding amount to obtain the corrected coal feeding amount.

Optionally, the circulating fluidized bed boiler system further comprises a water supply system for establishing an objective function based at least on the operating parameters of the circulating fluidized bed boiler system and the modified coal supply, comprising: according to the formula Establishing an objective function P, wherein k3 is a third preset coefficient, G is the boiler load, T3 is the temperature of the circulating fluidized bed boiler system, Y1 is the steam negative pressure, k4 is a fourth preset coefficient, F is the water supply flow of the water supply system, T4 is the temperature of the water supply system, Y2 is the water supply pressure of the water supply system, k5 is a fifth preset coefficient, and M is the corrected coal supply amount.

Optionally, adjusting the operating parameter to maximize the function value of the objective function includes: an obtaining step, namely obtaining an initial function value of the objective function; a calculation step of adjusting the operation parameters according to a preset direction, and calculating to obtain an updated function value, wherein the preset direction is to increase the operation parameters or decrease the operation parameters; a first repeating step of determining whether the updated function value is greater than the initial function value, and sequentially repeating the acquiring step and the calculating step at least once in the case that the updated function value is greater than the initial function value, and updating the initial function value in the acquiring step to the updated function value obtained in the previous repeating process in the repeating process until reaching a preset condition, wherein the preset condition is that the updated function value is smaller than the initial function value, and an absolute value of a difference value between the updated function value and the initial function value is smaller than an absolute value threshold; and a second repeating step of determining whether an absolute value of a difference between the updated function value and the initial function value is equal to or larger than an absolute value threshold when the updated function value is equal to or smaller than the initial function value, sequentially repeating the acquiring step and the calculating step at least once when the absolute value of the difference between the updated function value and the initial function value is equal to or larger than the absolute value threshold, updating the predetermined direction in the calculating step to a direction opposite to the predetermined direction in the repeating process, and updating the initial function value in the acquiring step to the updated function value obtained in the previous repeating process until the preset condition is reached.

According to another aspect of the present application, there is provided a control device of a circulating fluidized bed boiler system including a furnace and a coal supply system connected to the furnace, wherein the device comprises: an obtaining unit, configured to obtain a first average coal feeding amount, a first average boiler load, a second average coal feeding amount, and a second average boiler load, where the first average coal feeding amount is an average coal feeding amount of the coal feeding system in a first period before a current time, the first average boiler load is an average boiler load of the circulating fluidized bed boiler system in the first period, the second average coal feeding amount is an average coal feeding amount of the coal feeding system in a second period after the current time, and the second average boiler load is an average boiler load of the circulating fluidized bed boiler system in the second period; the first calculation unit is used for calculating to obtain the initial coal feeding amount of the coal feeding system according to the first average coal feeding amount, the first average boiler load, the second average coal feeding amount and the second average boiler load, and determining that the coal feeding amount of the coal feeding system is the initial coal feeding amount; the correcting unit is used for correcting the initial coal feeding amount according to the current oxygen content of the hearth and the current negative pressure of the hearth to obtain a corrected coal feeding amount, wherein the current oxygen content is the oxygen content of the hearth at the current moment, and the current negative pressure is the difference value between the pressure of the hearth at the current moment and the pressure outside the hearth; a setting unit for setting up an objective function according to at least an operation parameter of the circulating fluidized bed boiler system and the corrected coal feeding amount, and adjusting the operation parameter to maximize a function value of the objective function, wherein the operation parameter at least includes a boiler load of the circulating fluidized bed boiler system, a temperature of the circulating fluidized bed boiler system, and a steam negative pressure of the circulating fluidized bed boiler system, and the objective function is used for representing an operation efficiency of the circulating fluidized bed boiler system; and the control unit is used for determining the operation parameter corresponding to the maximum value of the function value as a target operation parameter and controlling the circulating fluidized bed boiler system to operate according to the target operation parameter.

According to a further aspect of the application there is provided an electronic device comprising a memory having a computer program stored therein and a processor arranged to perform any one of the methods by means of the computer program.

By applying the technical scheme of the application, firstly, according to a first average coal feeding amount, a first average boiler load, a second average coal feeding amount and a second average boiler load, calculating to obtain an initial coal feeding amount of a coal feeding system, and determining the coal feeding amount of the coal feeding system as the initial coal feeding amount; correcting the initial coal feeding amount according to the current oxygen content of the hearth and the current negative pressure of the hearth to obtain corrected coal feeding amount; then, establishing an objective function according to at least the operation parameters of the circulating fluidized bed boiler system and the corrected coal feeding amount, and adjusting the operation parameters to maximize the function value of the objective function; and finally, determining the operation parameter corresponding to the maximum value of the function value as a target operation parameter, and controlling the circulating fluidized bed boiler system to operate according to the target operation parameter. The scheme adjusts the average coal feeding amount and the boiler load according to the time period before and after the current moment, so that the conservation of total heat of the coal fed into the furnace can be realized, the total heat of the coal fed into the furnace is stabilized, the main steam pressure is stabilized, the fluctuation heat loss of the system is reduced, and the operation efficiency of the system is improved. In addition, according to the actual oxygen content and the actual negative pressure, the coal feeding amount is further adjusted in time, the oxygen amount and the negative pressure of the hearth are stabilized, and the stability of the boiler system is improved. And then, establishing an objective function, optimizing the objective function, searching the parameter with the optimal wind-coal ratio, so that the boiler is in the optimal working condition, the conversion efficiency of the boiler is improved, and the problem of low efficiency and stability of the circulating fluidized bed boiler system in the prior art is solved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

Fig. 1 illustrates a hardware block diagram of a mobile terminal performing a control method of a circulating fluidized bed boiler system according to an embodiment of the present application;

FIG. 2 shows a schematic flow chart of a control method of a circulating fluidized bed boiler system according to an embodiment of the present application;

FIG. 3 illustrates a flow diagram of a method of controlling a fume system provided in an embodiment in accordance with the application;

FIG. 4 is a flow chart of a method for controlling an initial coal feed amount according to an embodiment of the present application;

fig. 5 shows a flow chart of a control method for correcting a coal feeding amount according to an embodiment of the present application.

FIG. 6 shows a schematic view of a combustion process of a circulating fluidized bed boiler system provided in an embodiment according to the present application;

FIG. 7 is a flow chart of an objective function optimizing method according to an embodiment of the present application;

fig. 8 shows a block diagram of a control apparatus of a circulating fluidized bed boiler system according to an embodiment of the present application.

Wherein the above figures include the following reference numerals:

102. A processor; 104. a memory; 106. a transmission device; 108. and an input/output device.

Detailed Description

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.

In order that those skilled in the art will better understand the present application, a technical solution in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, shall fall within the scope of the present application.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate in order to describe the embodiments of the application herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

As described in the background art, the efficiency and stability of the circulating fluidized bed boiler system in the prior art are not high, and in order to solve the above problems, embodiments of the present application provide a control method of the circulating fluidized bed boiler system, a control device of the circulating fluidized bed boiler system, and an electronic device.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

The method embodiments provided in the embodiments of the present application may be performed in a mobile terminal, a computer terminal or similar computing device. Taking the operation on a mobile terminal as an example, fig. 1 is a block diagram of a hardware structure of a mobile terminal of a control method of a circulating fluidized bed boiler system according to an embodiment of the present application. As shown in fig. 1, a mobile terminal may include one or more (only one is shown in fig. 1) processors 102 (the processor 102 may include, but is not limited to, a microprocessor MCU or a processing device such as a programmable logic device FPGA) and a memory 104 for storing data, wherein the mobile terminal may also include a transmission device 106 for communication functions and an input-output device 108. It will be appreciated by those skilled in the art that the structure shown in fig. 1 is merely illustrative and not limiting of the structure of the mobile terminal described above. For example, the mobile terminal may also include more or fewer components than shown in fig. 1, or have a different configuration than shown in fig. 1.

The memory 104 may be used to store a computer program, for example, a software program of application software and a module, such as a computer program corresponding to a control method of a circulating fluidized bed boiler system in an embodiment of the present invention, and the processor 102 executes the computer program stored in the memory 104 to perform various functional applications and data processing, that is, to implement the above-mentioned method. Memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include memory remotely located relative to the processor 102, which may be connected to the mobile terminal via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or transmit data via a network. Specific examples of the network described above may include a wireless network provided by a communication provider of the mobile terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, simply referred to as a NIC) that can connect to other network devices through a base station to communicate with the internet. In one example, the transmission device 106 may be a Radio Frequency (RF) module, which is configured to communicate with the internet wirelessly.

In the present embodiment, a control method of a circulating fluidized bed boiler system operating on a mobile terminal, a computer terminal or the like is provided, it should be noted that the steps shown in the flowchart of the drawings may be performed in a computer system such as a set of computer executable instructions, and although a logical sequence is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order from that shown or described herein.

Fig. 2 is a flowchart of a control method of a circulating fluidized bed boiler system according to an embodiment of the present application. The circulating fluidized bed boiler system comprises a furnace and a coal supply system connected with the furnace, as shown in fig. 2, and the method comprises the following steps:

Step S201, obtaining a first average coal feeding amount, a first average boiler load, a second average coal feeding amount and a second average boiler load, wherein the first average coal feeding amount is the average coal feeding amount of the coal feeding system in a first time period before the current moment, the first average boiler load is the average boiler load of the circulating fluidized bed boiler system in the first time period, the second average coal feeding amount is the average coal feeding amount of the coal feeding system in a second time period after the current moment, and the second average boiler load is the average boiler load of the circulating fluidized bed boiler system in the second time period;

Specifically, the circulating fluidized bed boiler is a coal burning technology and is applied to the fields of power generation, heat supply, chemical industry and the like. The circulating fluidized bed boiler system mainly comprises a combustion chamber, a circulating system, a superheater, a reheater, an economizer, an air preheater and the like, wherein the combustion chamber is a core part of the circulating fluidized bed boiler, and in the combustion chamber, coal and air are mixed to form a fluidization state. The circulation system comprises a circulation pump, a separator and a feed back valve. The circulating pump conveys the material at the bottom of the combustion chamber to a separator, and the separator separates solid particles from gas. The solid particles are returned to the combustion chamber through a feed back valve, and the gas enters the subsequent superheater, reheater and the like. The superheater is located above the combustion chamber and has the main function of transferring the flue gas heat generated by combustion to water, so that the flue gas heat is changed into superheated steam. The reheater is mainly used for improving the temperature of the superheated steam and further improving the heat efficiency. The reheater is typically located above the superheater and exchanges heat with the superheated steam via the flue gas. The economizer is positioned at the tail part of the boiler system and mainly used for preheating water entering the boiler by utilizing the heat of the flue gas. The air preheater is used for recovering heat in the flue gas and preheating air entering the combustion chamber. The average coal feed amount can be calculated by the ratio of the total coal feed amount to the time length in a certain time period, and the average boiler load can be calculated by the ratio of the total boiler load to the time length in a certain time period.

Step S202, calculating an initial coal feeding amount of the coal feeding system according to the first average coal feeding amount, the first average boiler load, the second average coal feeding amount and the second average boiler load, and determining the coal feeding amount of the coal feeding system as the initial coal feeding amount;

specifically, the main idea of the steps is that the coal feeding heat value analysis module adjusts the coal feeding amount according to the average coal feeding amount and the average boiler load before and after the current moment, so as to ensure the energy balance of the coal feeding entering the hearth and realize the stable operation of the boiler.

Step S203, correcting the initial coal feeding amount according to the current oxygen content of the hearth and the current negative pressure of the hearth to obtain a corrected coal feeding amount, wherein the current oxygen content is the oxygen content of the hearth at the current time, and the current negative pressure is the difference value between the pressure of the hearth at the current time and the pressure outside the hearth;

Specifically, after the coal amount used by the circulating fluidized bed boiler and the air brought by the secondary air blower are mixed and combusted in the hearth, the flue gas is brought out by the induced draft fan and is discharged through a chimney. Only when the 'coal amount + air amount = induced air amount' is given, the circulating fluidized bed boiler can normally operate. When the oxygen content is too low due to insufficient output of the secondary air blower, if the coal feeding amount is not timely reduced, oxygen-deficient combustion of the coal feeding is caused, CO is increased, and incomplete loss of the combustion chemistry of the coal feeding is caused. When the negative pressure is too small due to insufficient output of the induced draft fan, if the coal feeding amount is not timely reduced, positive pressure of a hearth is out of limit, and equipment safety and production safety are possibly endangered. That is, the adjustment of the coal feed amount is required according to the current oxygen content and the current negative pressure.

Step S204, establishing an objective function according to at least the operation parameters of the circulating fluidized bed boiler system and the corrected coal feeding amount, and adjusting the operation parameters to maximize the function value of the objective function, wherein the operation parameters at least comprise the boiler load of the circulating fluidized bed boiler system, the temperature of the circulating fluidized bed boiler system and the steam negative pressure of the circulating fluidized bed boiler system, and the objective function is used for representing the operation efficiency of the circulating fluidized bed boiler system;

Specifically, the oxygen content after the economizer in the circulating fluidized bed boiler represents the internal air-fuel ratio, the excessive oxygen content causes the increase of unit consumption of a fan or the increase of heat dissipation loss and smoke exhaust loss, and the excessive oxygen content causes the chemical incomplete combustion loss, so that the objective function needs to be optimized.

Step S205, determining the operation parameter corresponding to the maximum value of the function value as a target operation parameter, and controlling the circulating fluidized bed boiler system to operate according to the target operation parameter.

Specifically, the maximum value of the function value is equivalent to an optimal oxygen control point, and the boiler operation efficiency is optimal under the working condition. The setting of the target operation parameters can be realized by adjusting the opening degree of a baffle of the secondary air blower and the like.

According to the embodiment, firstly, according to a first average coal feeding amount, a first average boiler load, a second average coal feeding amount and a second average boiler load, an initial coal feeding amount of a coal feeding system is calculated, and the coal feeding amount of the coal feeding system is determined to be the initial coal feeding amount; correcting the initial coal feeding amount according to the current oxygen content of the hearth and the current negative pressure of the hearth to obtain corrected coal feeding amount; then, establishing an objective function according to at least the operation parameters of the circulating fluidized bed boiler system and the corrected coal feeding amount, and adjusting the operation parameters to maximize the function value of the objective function; and finally, determining the operation parameter corresponding to the maximum value of the function value as a target operation parameter, and controlling the circulating fluidized bed boiler system to operate according to the target operation parameter. The scheme adjusts the average coal feeding amount and the boiler load according to the time period before and after the current moment, so that the conservation of total heat of the coal fed into the furnace can be realized, the total heat of the coal fed into the furnace is stabilized, the main steam pressure is stabilized, the fluctuation heat loss of the system is reduced, and the operation efficiency of the system is improved. In addition, according to the actual oxygen content and the actual negative pressure, the coal feeding amount is further adjusted in time, the oxygen amount and the negative pressure of the hearth are stabilized, and the stability of the boiler system is improved. And then, establishing an objective function, optimizing the objective function, searching the parameter with the optimal wind-coal ratio, so that the boiler is in the optimal working condition, the conversion efficiency of the boiler is improved, and the problem of low efficiency and stability of the circulating fluidized bed boiler system in the prior art is solved.

In the specific implementation process, the circulating fluidized bed boiler system further comprises a flue gas system connected with the hearth, the flue gas system comprises an induced draft device and an air supply device, and the method further comprises the following steps: step S206, calculating a difference value between a first coal feeding amount and a second coal feeding amount to obtain a coal feeding variation amount, wherein the first coal feeding amount is the coal feeding amount of the coal feeding system in the first time period, and the second coal feeding amount is the coal feeding amount of the coal feeding system in the second time period; step S207, determining a current air-fuel ratio according to the current oxygen content and a mapping relation, wherein the mapping relation is used for representing the mapping relation between the oxygen content of the hearth and the air-fuel ratio of the hearth; step S208, calculating an air supply variable quantity according to the current air-fuel ratio and the coal supply variable quantity, and adjusting the air supply quantity of the air supply device according to the air supply variable quantity; step S209, according to the coal supply variable quantity and the air supply variable quantity, the induced air variable quantity is calculated, and according to the induced air variable quantity, the induced air quantity of the induced air device is adjusted. Because the external steam pressure is changed frequently, and after the hearth negative pressure and the oxygen amount are changed, the air-smoke system is adjusted, hysteresis adjustment is caused, parameter fluctuation is large, and equipment response is not timely, so that the method can judge the steam pressure and the coal supply amount change timely, and the air-smoke system is activated in advance, thereby being beneficial to keeping the hearth negative pressure parameter and the oxygen amount parameter stable, further improving the anti-interference capability of the boiler and improving the operation stability of the boiler system.

Specifically, the induced air device can be an induced draft fan, the air supply device can be an air blower, the induced draft fan is arranged on a flue at the tail part of the boiler and used for extracting flue gas generated by combustion from the interior of the boiler, and the flue gas is conveyed to environmental protection equipment such as dust removal, desulfurization and the like and finally discharged into the atmosphere. The blower is installed near the feeding system of the boiler and is used for conveying proper amount of primary air and secondary air to the boiler bed layer, so that the combustion efficiency and stability of the boiler are ensured. In practical applications, the mapping relationship may be a matrix relationship function of oxygen content in the furnace and an air-fuel ratio of the furnace.

In order to further and rapidly calculate the air supply variation according to the current air-fuel ratio and the coal supply variation, the step S208 of the present application may be implemented by: step S2081, calculating the product of the current air-fuel ratio and the coal supply variation to obtain the air supply variation.

Specifically, in the above step, when the total amount of coal is changed, the air supply amount of the air supply device is adjusted in real time according to the current air-fuel ratio and the air supply variation.

The step S209 may be implemented in other manners, for example: step S2091, calculating a sum of the coal supply variation and the air supply variation to obtain the induced draft variation. The method can further and rapidly calculate the induced air variable quantity according to the coal feeding variable quantity and the air supply variable quantity.

Specifically, in practical application, after calculating the sum of the coal feeding variable quantity and the air supply variable quantity, a correction coefficient can be obtained by calculation according to the actual operation parameters of the circulating fluidized bed boiler, and the product of the correction coefficient and the sum is calculated to obtain the induced air variable quantity. The control method of the air and smoke system is as shown in fig. 3, and according to the total amount of coal, the air increment and the negative pressure of different hearths, advanced calculation of the hearth negative pressure is performed to obtain a calculation result, and the opening degree of the baffle plate of the induced draft fan is adjusted according to the calculation result. Similarly, for the air supply device, advanced calculation of the air supply quantity of the hearth, namely, the oxygen quantity is performed according to the total quantity of the coal, the air supply quantity and the oxygen quantity of different hearths, a calculation result is obtained, and the opening degree of the air supply device baffle is adjusted according to the calculation result.

In some embodiments, the step S202 may be specifically implemented by the following steps: step S2021, calculating the ratio of the first average coal feeding amount to the first average boiler load to obtain a first ratio; step S2022, calculating the ratio of the second average coal feeding amount to the first average boiler load to obtain a second ratio; step S2023, calculating a ratio of the second ratio to the first ratio to obtain the initial coal supply. The method can further rapidly calculate the initial coal supply amount.

Specifically, the ratio of the average coal feeding amount to the average boiler load represents the unit consumption of the boiler, namely the coal feeding amount required for each 1t of steam production, and the initial coal feeding amount can be further and rapidly calculated according to the proportional relation of the unit consumption of the boiler before and after the current moment. In the calculation process of the initial coal feeding amount, as shown in fig. 4, a coal amount heat value analysis module counts the proportional relation between the average coal feeding amount and the average load of the boiler for a period of time, deduces the coal feeding unit consumption change, inputs the coal feeding unit consumption change into a system coordination control module in a control module, and further adjusts the coal feeding amount through different coal feeders to ensure the balance of the coal feeding energy entering a hearth and realize the stable operation of the boiler, wherein the main steam flow of the boiler is the load of the boiler.

In some embodiments, the step S203 may be specifically implemented by the following steps: step S2031, calculating a first preliminary coal supply amount M1 according to a formula m1=k1× (O-OL) ×t1, where k1 is a first predetermined coefficient, O is the current oxygen content, OL is a preset minimum oxygen content of the furnace, and T1 is a duration for which the current oxygen content is lower than the minimum oxygen content; step S2032, calculating a second preliminary coal feeding amount M2 according to a formula m2=k2× (Y-YH) ×t2, where k2 is a second predetermined coefficient, Y is the current negative pressure, YH is a preset maximum negative pressure of the furnace, and T2 is a duration time for which the current negative pressure is greater than the maximum negative pressure; step S2033, calculating an average value of the first preliminary coal supply amount and the second preliminary coal supply amount, and obtaining the corrected coal supply amount. The method can further rapidly calculate the corrected coal feeding amount.

Specifically, as shown in fig. 5, the calculation process of the corrected coal feeding amount uses too low oxygen and too high negative pressure as two constraint conditions, the coal feeding amount is adjusted, two preliminary coal feeding amounts are calculated respectively, the average value is calculated, the corrected coal feeding amount is obtained, and the corrected coal feeding amount is input into the control module to realize the correction adjustment of the total coal feeding amount.

The circulating fluidized bed boiler system further comprises a water supply system, and the step S204 may be implemented by: step S2041, according to the formulaEstablishing an objective function P, wherein k3 is a third preset coefficient, G is the boiler load, T3 is the temperature of the circulating fluidized bed boiler system, Y1 is the steam negative pressure, k4 is a fourth preset coefficient, F is the water supply flow of the water supply system, T4 is the temperature of the water supply system, Y2 is the water supply pressure of the water supply system, k5 is a fifth preset coefficient, and M is the corrected coal supply amount. The method can further quickly establish the objective function.

Specifically, the third predetermined coefficient and the fourth predetermined coefficient may be set in advance according to the actual combustion state of the boiler.

The step S204 may be further implemented by: step S2042, obtaining an initial function value of the objective function; step S2043, a calculation step, in which the operation parameters are adjusted according to a preset direction, and updated function values are calculated, wherein the preset direction is to increase the operation parameters or decrease the operation parameters; step S2044, a first repetition step of determining whether the updated function value is greater than the initial function value, and if the updated function value is greater than the initial function value, repeating the acquiring step and the calculating step at least once in sequence, and updating the initial function value in the acquiring step to the updated function value obtained in the previous repetition in the repetition until reaching a preset condition, wherein the preset condition is that the updated function value is less than the initial function value, and an absolute value of a difference value between the updated function value and the initial function value is less than an absolute value threshold; and a second repeating step of determining whether or not an absolute value of a difference between the updated function value and the initial function value is equal to or larger than an absolute value threshold when the updated function value is equal to or smaller than the initial function value, and sequentially repeating the acquiring step and the calculating step at least once when the absolute value of the difference between the updated function value and the initial function value is equal to or larger than the absolute value threshold, and updating the predetermined direction in the calculating step to be opposite to the predetermined direction in the repeating step, and updating the initial function value in the acquiring step to be the updated function value obtained in the previous repeating step until the predetermined condition is reached. The method can further rapidly realize the optimizing process.

Specifically, the boiler combustion process is shown in FIG. 6, and there is an optimum oxygen control point during the combustion process, under which the boiler operation efficiency is optimum. Due to frequent fluctuation of working conditions, the circulating fluidized bed furnace cannot be operated in an optimal combustion state for a long time by manpower. According to the change trend of the parameters after each operation, part of parameters such as control quantity and the like are manually changed, so that the value of Q < 2> +Q < 3 > +Q < 4 > is minimized until the optimal point is approached. In the optimizing process, firstly, self-optimizing permission starting conditions are set, (1) coal feeding amount, a secondary fan and a draught fan are adjustable, and the opening is provided with allowance up and down; (2) The change rate of the main steam pressure is less than 0.1 MPa/min, the change rate of the oxygen amount is less than 0.2%/min, and the change rate of the hearth negative pressure is less than 80 Pa/min; (3) The coal feeding amount, the secondary air blower baffle and the induced draft fan baffle are all in an automatic state. According to the formula: sop=k5×o, where k5 may be 5% -10% and O is the current oxygen content. The optimizing process is shown in fig. 7, (1) setting an optimizing model as an operating state, and recording an initial objective function value P1; (2) Changing an oxygen increment control point SOP, namely increasing the opening of a baffle of the secondary fan, and taking 3 minutes according to the dynamic reaction process of the circulating fluidized bed boiler, wherein the current objective function P2 is recorded at the moment; (3) If P2> P1, indicate find direction correct, continue find along this direction, go to (2); (4) If P2 is less than P1, and ABS (P2-P1) > E and E are allowed errors, indicating that the searching direction is wrong, setting an oxygen increment control point to SOP (-1), namely closing the opening of a blower baffle, and carrying out reverse optimization, and switching to (2); (5) If P2 is less than P1 and ABS (P2-P1) is less than E, the current oxygen amount is the optimal state, the current optimizing is ended, and the optimizing model is set to be in a stop state.

The embodiment of the application also provides a control device of the circulating fluidized bed boiler system, and the control device of the circulating fluidized bed boiler system can be used for executing the control method for the circulating fluidized bed boiler system. The device is used for realizing the above embodiments and preferred embodiments, and is not described in detail. As used below, the term "module" may be a combination of software and/or hardware that implements a predetermined function. While the means described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and contemplated.

The following describes a control device of a circulating fluidized bed boiler system provided by an embodiment of the present application.

Fig. 8 is a schematic view of a control apparatus of a circulating fluidized bed boiler system according to an embodiment of the present application. The circulating fluidized bed boiler system comprises a furnace and a coal supply system connected with the furnace, as shown in fig. 8, the device comprises:

An obtaining unit 10 configured to obtain a first average coal feeding amount, a first average boiler load, a second average coal feeding amount, and a second average boiler load, wherein the first average coal feeding amount is an average coal feeding amount of the coal feeding system in a first period of time before a current time, the first average boiler load is an average boiler load of the circulating fluidized bed boiler system in the first period of time, the second average coal feeding amount is an average coal feeding amount of the coal feeding system in a second period of time after the current time, and the second average boiler load is an average boiler load of the circulating fluidized bed boiler system in the second period of time;

A first calculation unit 20 configured to calculate an initial coal supply amount of the coal supply system based on the first average coal supply amount, the first average boiler load, the second average coal supply amount, and the second average boiler load, and determine that the coal supply amount of the coal supply system is the initial coal supply amount;

A correction unit 30, configured to correct the initial coal feeding amount according to a current oxygen content of the furnace and a current negative pressure of the furnace, to obtain a corrected coal feeding amount, where the current oxygen content is an oxygen content of the furnace at the current time, and the current negative pressure is a difference between a pressure of the furnace at the current time and a pressure of an outside of the furnace;

A setting unit 40 for setting an objective function according to at least the operation parameters of the circulating fluidized bed boiler system and the corrected coal supply amount, and adjusting the operation parameters to maximize the function value of the objective function, wherein the operation parameters include at least the boiler load of the circulating fluidized bed boiler system, the temperature of the circulating fluidized bed boiler system, and the steam negative pressure of the circulating fluidized bed boiler system, and the objective function is used for representing the operation efficiency of the circulating fluidized bed boiler system;

And a control unit 50 for determining the operation parameter corresponding to the maximum value of the function value as a target operation parameter and controlling the circulating fluidized bed boiler system to operate according to the target operation parameter.

According to the embodiment, a first calculation unit calculates an initial coal feeding amount of a coal feeding system according to a first average coal feeding amount, a first average boiler load, a second average coal feeding amount and a second average boiler load, and determines the coal feeding amount of the coal feeding system as the initial coal feeding amount; the correction unit corrects the initial coal feeding amount according to the current oxygen content of the hearth and the current negative pressure of the hearth to obtain corrected coal feeding amount; the building unit at least builds an objective function according to the operation parameters of the circulating fluidized bed boiler system and the corrected coal feeding amount, and adjusts the operation parameters to maximize the function value of the objective function; the control unit determines the operation parameter corresponding to the maximum value of the function value as a target operation parameter, and controls the circulating fluidized bed boiler system to operate according to the target operation parameter. The scheme adjusts the average coal feeding amount and the boiler load according to the time period before and after the current moment, so that the conservation of total heat of the coal fed into the furnace can be realized, the total heat of the coal fed into the furnace is stabilized, the main steam pressure is stabilized, the fluctuation heat loss of the system is reduced, and the operation efficiency of the system is improved. In addition, according to the actual oxygen content and the actual negative pressure, the coal feeding amount is further adjusted in time, the oxygen amount and the negative pressure of the hearth are stabilized, and the stability of the boiler system is improved. And then, establishing an objective function, optimizing the objective function, searching the parameter with the optimal wind-coal ratio, so that the boiler is in the optimal working condition, the conversion efficiency of the boiler is improved, and the problem of low efficiency and stability of the circulating fluidized bed boiler system in the prior art is solved.

In a specific implementation process, the circulating fluidized bed boiler system further comprises an air-smoke system connected with the hearth, the air-smoke system comprises an air inducing device and an air supply device, the device further comprises a second calculation unit, a determination unit, a third calculation unit and a fourth calculation unit, wherein the second calculation unit is used for calculating a difference value between a first coal feeding amount and a second coal feeding amount to obtain a coal feeding variation, the first coal feeding amount is the coal feeding amount of the coal feeding system in the first time period, and the second coal feeding amount is the coal feeding amount of the coal feeding system in the second time period; the determining unit is used for determining the current air-fuel ratio according to the current oxygen content and the mapping relation, wherein the mapping relation is used for representing the mapping relation between the oxygen content of the hearth and the air-fuel ratio of the hearth; the third calculation unit is used for calculating the air supply variable quantity according to the current air-fuel ratio and the coal supply variable quantity, and adjusting the air supply quantity of the air supply device according to the air supply variable quantity; and the fourth calculation unit is used for calculating the induced air variable quantity according to the coal feeding variable quantity and the air supply variable quantity, and adjusting the induced air quantity of the induced air device according to the induced air variable quantity. Because the external steam pressure changes frequently, after the hearth negative pressure and the oxygen amount change, the air-smoke system is adjusted, hysteresis adjustment can be caused, the parameter fluctuation is large, and the equipment response is not timely, so that the device can judge the steam pressure and the coal supply amount change timely, and the air-smoke system is activated in advance, thereby being beneficial to keeping the hearth negative pressure parameter and the oxygen amount parameter stable, further improving the anti-interference capability of the boiler and improving the operation stability of the boiler system.

In order to further quickly calculate the air supply variation according to the current air-fuel ratio and the coal supply variation, the third calculation unit of the present application is further configured to calculate a product of the current air-fuel ratio and the coal supply variation to obtain the air supply variation.

The fourth calculation unit is further configured to calculate a sum of the coal supply variation and the air supply variation to obtain the induced air variation. The device can further calculate the induced air variable quantity according to the coal feeding variable quantity and the air supply variable quantity.

In some embodiments, the first calculating unit includes a first calculating module, a second calculating module, and a third calculating module, where the first calculating module is configured to calculate a ratio of the first average coal feeding amount to the first average boiler load to obtain a first ratio; the second calculation module is used for calculating the ratio of the second average coal feeding amount to the first average boiler load to obtain a second ratio; the third calculation module is used for calculating the ratio of the second ratio to the first ratio to obtain the initial coal feeding amount. The device can further quickly calculate the initial coal feeding amount.

In some embodiments, the correction unit includes a fourth calculation module, a fifth calculation module, and a sixth calculation module, where the fourth calculation module is configured to calculate a first preliminary coal feeding amount M1 according to a formula m1=k1× (O-OL) ×t1, where k1 is a first predetermined coefficient, O is the current oxygen content, OL is a preset minimum oxygen content of the furnace, and T1 is a duration for which the current oxygen content is lower than the minimum oxygen content; the fifth calculation module is configured to calculate a second preliminary coal feeding amount M2 according to a formula m2=k2× (Y-YH) ×t2, where k2 is a second predetermined coefficient, Y is the current negative pressure, YH is a preset maximum negative pressure of the furnace chamber, and T2 is a duration time for which the current negative pressure is greater than the maximum negative pressure; the sixth calculation module is configured to calculate an average value of the first preliminary coal supply amount and the second preliminary coal supply amount to obtain the corrected coal supply amount. The device can further quickly calculate the corrected coal feeding amount.

The circulating fluidized bed boiler system further comprises a water supply system, and the building unit comprises a building module for building according to the formulaEstablishing an objective function P, wherein k3 is a third preset coefficient, G is the boiler load, T3 is the temperature of the circulating fluidized bed boiler system, Y1 is the steam negative pressure, k4 is a fourth preset coefficient, F is the water supply flow of the water supply system, T4 is the temperature of the water supply system, Y2 is the water supply pressure of the water supply system, k5 is a fifth preset coefficient, and M is the corrected coal supply amount. The device can further quickly establish the objective function.

The establishing unit further comprises an acquiring module, a seventh calculating module, a first repeating module and a second repeating module, wherein the acquiring module is used for acquiring the initial function value of the objective function; the seventh calculation module is used for calculating, namely adjusting the operation parameters according to a preset direction, and calculating to obtain an updated function value, wherein the preset direction is to increase the operation parameters or decrease the operation parameters; the first repeating module is used for determining whether the updated function value is larger than the initial function value or not, and repeating the acquiring step and the calculating step at least once in sequence when the updated function value is larger than the initial function value, and updating the initial function value in the acquiring step to the updated function value obtained in the previous repeating process in the repeating process until reaching a preset condition, wherein the preset condition is that the updated function value is smaller than the initial function value, and the absolute value of the difference value between the updated function value and the initial function value is smaller than an absolute value threshold; and a second repeating module configured to determine whether an absolute value of a difference between the updated function value and the initial function value is equal to or larger than an absolute value threshold when the updated function value is equal to or smaller than the initial function value, sequentially repeat the acquiring step and the calculating step at least once when the absolute value of the difference between the updated function value and the initial function value is equal to or larger than the absolute value threshold, and update the predetermined direction in the calculating step to a direction opposite to the predetermined direction in the repeating step, and update the initial function value in the acquiring step to the updated function value obtained in the previous repeating step until the predetermined condition is reached. The device can further quickly realize the optimizing process.

The control device of the circulating fluidized bed boiler system comprises a processor and a memory, wherein the acquisition unit, the first calculation unit, the correction unit, the establishment unit, the control unit and the like are all stored in the memory as program units, and the processor executes the program units stored in the memory to realize corresponding functions. The modules are all located in the same processor; or the above modules may be located in different processors in any combination.

The processor includes a kernel, and the kernel fetches the corresponding program unit from the memory. The kernel can be provided with one or more than one, and the circulating fluidized bed boiler system is controlled by adjusting the parameters of the kernel.

The memory may include volatile memory, random Access Memory (RAM), and/or nonvolatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM), among other forms in computer readable media, the memory including at least one memory chip.

The embodiment of the invention provides a computer readable storage medium, which comprises a stored program, wherein the program is used for controlling equipment where the computer readable storage medium is located to execute the control method of the circulating fluidized bed boiler system.

The embodiment of the invention provides a processor, which is used for running a program, wherein the control method of the circulating fluidized bed boiler system is executed when the program runs.

The embodiment of the invention provides equipment, which comprises a processor, a memory and a program stored in the memory and capable of running on the processor, wherein the processor realizes at least the following steps when executing the program:

The device herein may be a server, PC, PAD, cell phone, etc.

The application also provides a computer program product adapted to perform, when executed on a data processing device, a program initialized with at least the following method steps:

It will be appreciated by those skilled in the art that the modules or steps of the invention described above may be implemented in a general purpose computing device, they may be concentrated on a single computing device, or distributed across a network of computing devices, they may be implemented in program code executable by computing devices, so that they may be stored in a storage device for execution by computing devices, and in some cases, the steps shown or described may be performed in a different order than that shown or described herein, or they may be separately fabricated into individual integrated circuit modules, or multiple modules or steps of them may be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any specific combination of hardware and software.

It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In one typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include volatile memory in a computer-readable medium, random Access Memory (RAM) and/or nonvolatile memory, etc., such as Read Only Memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

Computer readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device. Computer-readable media, as defined herein, does not include transitory computer-readable media (transmission media), such as modulated data signals and carrier waves.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises an element.

From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

1) According to the control method of the circulating fluidized bed boiler system, firstly, according to a first average coal feeding amount, a first average boiler load, a second average coal feeding amount and a second average boiler load, an initial coal feeding amount of the coal feeding system is calculated, and the coal feeding amount of the coal feeding system is determined to be the initial coal feeding amount; correcting the initial coal feeding amount according to the current oxygen content of the hearth and the current negative pressure of the hearth to obtain corrected coal feeding amount; then, establishing an objective function according to at least the operation parameters of the circulating fluidized bed boiler system and the corrected coal feeding amount, and adjusting the operation parameters to maximize the function value of the objective function; and finally, determining the operation parameter corresponding to the maximum value of the function value as a target operation parameter, and controlling the circulating fluidized bed boiler system to operate according to the target operation parameter. The scheme adjusts the average coal feeding amount and the boiler load according to the time period before and after the current moment, so that the conservation of total heat of the coal fed into the furnace can be realized, the total heat of the coal fed into the furnace is stabilized, the main steam pressure is stabilized, the fluctuation heat loss of the system is reduced, and the operation efficiency of the system is improved. In addition, according to the actual oxygen content and the actual negative pressure, the coal feeding amount is further adjusted in time, the oxygen amount and the negative pressure of the hearth are stabilized, and the stability of the boiler system is improved. And then, establishing an objective function, optimizing the objective function, searching the parameter with the optimal wind-coal ratio, so that the boiler is in the optimal working condition, the conversion efficiency of the boiler is improved, and the problem of low efficiency and stability of the circulating fluidized bed boiler system in the prior art is solved.

2) According to the control device of the circulating fluidized bed boiler system, the first calculation unit calculates the initial coal feeding amount of the coal feeding system according to the first average coal feeding amount, the first average boiler load, the second average coal feeding amount and the second average boiler load, and determines the coal feeding amount of the coal feeding system as the initial coal feeding amount; the correction unit corrects the initial coal feeding amount according to the current oxygen content of the hearth and the current negative pressure of the hearth to obtain corrected coal feeding amount; the building unit at least builds an objective function according to the operation parameters of the circulating fluidized bed boiler system and the corrected coal feeding amount, and adjusts the operation parameters to maximize the function value of the objective function; the control unit determines the operation parameter corresponding to the maximum value of the function value as a target operation parameter, and controls the circulating fluidized bed boiler system to operate according to the target operation parameter. The scheme adjusts the average coal feeding amount and the boiler load according to the time period before and after the current moment, so that the conservation of total heat of the coal fed into the furnace can be realized, the total heat of the coal fed into the furnace is stabilized, the main steam pressure is stabilized, the fluctuation heat loss of the system is reduced, and the operation efficiency of the system is improved. In addition, according to the actual oxygen content and the actual negative pressure, the coal feeding amount is further adjusted in time, the oxygen amount and the negative pressure of the hearth are stabilized, and the stability of the boiler system is improved. And then, establishing an objective function, optimizing the objective function, searching the parameter with the optimal wind-coal ratio, so that the boiler is in the optimal working condition, the conversion efficiency of the boiler is improved, and the problem of low efficiency and stability of the circulating fluidized bed boiler system in the prior art is solved.

The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method of controlling a circulating fluidized bed boiler system, the circulating fluidized bed boiler system comprising a furnace and a coal feed system connected to the furnace, wherein the method comprises:

Acquiring a first average coal feeding amount, a first average boiler load, a second average coal feeding amount and a second average boiler load, wherein the first average coal feeding amount is the average coal feeding amount of the coal feeding system in a first time period before the current moment, the first average boiler load is the average boiler load of the circulating fluidized bed boiler system in the first time period, the second average coal feeding amount is the average coal feeding amount of the coal feeding system in a second time period after the current moment, and the second average boiler load is the average boiler load of the circulating fluidized bed boiler system in the second time period;

according to the first average coal feeding amount, the first average boiler load, the second average coal feeding amount and the second average boiler load, calculating to obtain initial coal feeding amount of the coal feeding system, and determining the coal feeding amount of the coal feeding system as the initial coal feeding amount;

Correcting the initial coal feeding amount according to the current oxygen content of the hearth and the current negative pressure of the hearth to obtain corrected coal feeding amount, wherein the current oxygen content is the oxygen content of the hearth at the current moment, and the current negative pressure is the difference value between the pressure of the hearth at the current moment and the pressure outside the hearth;

Establishing an objective function according to at least the operation parameters of the circulating fluidized bed boiler system and the corrected coal feeding amount, and adjusting the operation parameters to maximize the function value of the objective function, wherein the operation parameters at least comprise the boiler load of the circulating fluidized bed boiler system, the temperature of the circulating fluidized bed boiler system and the steam negative pressure of the circulating fluidized bed boiler system, and the objective function is used for representing the operation efficiency of the circulating fluidized bed boiler system;

And determining the operation parameter corresponding to the maximum value of the function value as a target operation parameter, and controlling the circulating fluidized bed boiler system to operate according to the target operation parameter.

2. The method of claim 1, wherein the circulating fluidized bed boiler system further comprises a fume system coupled to the furnace, the fume system comprising a draft device and an air supply device, wherein the method further comprises:

Calculating a difference value between a first coal feeding amount and a second coal feeding amount to obtain a coal feeding variation amount, wherein the first coal feeding amount is the coal feeding amount of the coal feeding system in the first time period, and the second coal feeding amount is the coal feeding amount of the coal feeding system in the second time period;

Determining a current air-fuel ratio according to the current oxygen content and a mapping relation, wherein the mapping relation is used for representing the mapping relation between the oxygen content of the hearth and the air-fuel ratio of the hearth;

Calculating to obtain an air supply variable quantity according to the current air-fuel ratio and the coal supply variable quantity, and adjusting the air supply quantity of the air supply device according to the air supply variable quantity;

and calculating the induced air variable quantity according to the coal feeding variable quantity and the air supply variable quantity, and adjusting the induced air quantity of the induced air device according to the induced air variable quantity.

3. The method according to claim 2, wherein calculating an air supply variation amount based on the current air-fuel ratio and the coal supply variation amount includes:

And calculating the product of the current air-fuel ratio and the coal supply variation to obtain the air supply variation.

4. The method of claim 2, wherein calculating an induced draft variation from the coal feed variation and the air supply variation comprises:

And calculating the sum of the coal feeding variable quantity and the air supply variable quantity to obtain the induced air variable quantity.

5. The method of claim 1, wherein calculating an initial coal feed amount for the coal feed system based on the first average coal feed amount, the first average boiler load, the second average coal feed amount, and the second average boiler load comprises:

calculating the ratio of the first average coal feeding amount to the first average boiler load to obtain a first ratio;

calculating the ratio of the second average coal feeding amount to the first average boiler load to obtain a second ratio;

And calculating the ratio of the second ratio to the first ratio to obtain the initial coal feeding amount.

6. The method of claim 1, wherein correcting the initial coal feed amount based on the current oxygen content of the furnace and the current negative pressure of the furnace, results in a corrected coal feed amount, comprising:

Calculating to obtain a first preliminary coal feeding amount M1 according to a formula m1=k1× (O-OL) ×t1, wherein k1 is a first predetermined coefficient, O is the current oxygen content, OL is a preset minimum oxygen content of the furnace chamber, and T1 is a duration time for which the current oxygen content is lower than the minimum oxygen content;

calculating to obtain a second preliminary coal feeding amount M2 according to a formula M2=k2× (Y-YH) x T2, wherein k2 is a second predetermined coefficient, Y is the current negative pressure, YH is a preset maximum negative pressure of the hearth, and T2 is the duration time length that the current negative pressure is greater than the maximum negative pressure;

And calculating the average value of the first preparation coal feeding amount and the second preparation coal feeding amount to obtain the corrected coal feeding amount.

7. The method of claim 1, wherein the circulating fluidized bed boiler system further comprises a feedwater system, wherein establishing an objective function based at least on the operating parameters of the circulating fluidized bed boiler system and the modified coal feed amount comprises:

According to the formula Establishing an objective function P, wherein k3 is a third preset coefficient, G is the boiler load, T3 is the temperature of the circulating fluidized bed boiler system, Y1 is the steam negative pressure, k4 is a fourth preset coefficient, F is the water supply flow of the water supply system, T4 is the temperature of the water supply system, Y2 is the water supply pressure of the water supply system, k5 is a fifth preset coefficient, and M is the corrected coal supply amount.

8. The method of claim 1, wherein adjusting the operating parameter to maximize the function value of the objective function comprises:

an obtaining step, namely obtaining an initial function value of the objective function;

A calculation step of adjusting the operation parameters according to a preset direction, and calculating to obtain an updated function value, wherein the preset direction is to increase the operation parameters or decrease the operation parameters;

A first repeating step of determining whether the updated function value is greater than the initial function value, and sequentially repeating the acquiring step and the calculating step at least once in the case that the updated function value is greater than the initial function value, and updating the initial function value in the acquiring step to the updated function value obtained in the previous repeating process in the repeating process until reaching a preset condition, wherein the preset condition is that the updated function value is smaller than the initial function value, and an absolute value of a difference value between the updated function value and the initial function value is smaller than an absolute value threshold;

And a second repeating step of determining whether an absolute value of a difference between the updated function value and the initial function value is equal to or larger than an absolute value threshold when the updated function value is equal to or smaller than the initial function value, sequentially repeating the acquiring step and the calculating step at least once when the absolute value of the difference between the updated function value and the initial function value is equal to or larger than the absolute value threshold, updating the predetermined direction in the calculating step to a direction opposite to the predetermined direction in the repeating process, and updating the initial function value in the acquiring step to the updated function value obtained in the previous repeating process until the preset condition is reached.

9. A control device for a circulating fluidized bed boiler system, characterized in that the circulating fluidized bed boiler system comprises a furnace and a coal supply system connected to the furnace, wherein the device comprises:

An obtaining unit, configured to obtain a first average coal feeding amount, a first average boiler load, a second average coal feeding amount, and a second average boiler load, where the first average coal feeding amount is an average coal feeding amount of the coal feeding system in a first period before a current time, the first average boiler load is an average boiler load of the circulating fluidized bed boiler system in the first period, the second average coal feeding amount is an average coal feeding amount of the coal feeding system in a second period after the current time, and the second average boiler load is an average boiler load of the circulating fluidized bed boiler system in the second period;

The first calculation unit is used for calculating to obtain the initial coal feeding amount of the coal feeding system according to the first average coal feeding amount, the first average boiler load, the second average coal feeding amount and the second average boiler load, and determining that the coal feeding amount of the coal feeding system is the initial coal feeding amount;

The correcting unit is used for correcting the initial coal feeding amount according to the current oxygen content of the hearth and the current negative pressure of the hearth to obtain a corrected coal feeding amount, wherein the current oxygen content is the oxygen content of the hearth at the current moment, and the current negative pressure is the difference value between the pressure of the hearth at the current moment and the pressure outside the hearth;

A setting unit for setting up an objective function according to at least an operation parameter of the circulating fluidized bed boiler system and the corrected coal feeding amount, and adjusting the operation parameter to maximize a function value of the objective function, wherein the operation parameter at least includes a boiler load of the circulating fluidized bed boiler system, a temperature of the circulating fluidized bed boiler system, and a steam negative pressure of the circulating fluidized bed boiler system, and the objective function is used for representing an operation efficiency of the circulating fluidized bed boiler system;

and the control unit is used for determining the operation parameter corresponding to the maximum value of the function value as a target operation parameter and controlling the circulating fluidized bed boiler system to operate according to the target operation parameter.

10. An electronic device comprising a memory and a processor, wherein the memory has stored therein a computer program, the processor being arranged to perform the method of any of claims 1 to 8 by means of the computer program.