CN113007123A

CN113007123A - Control method and device of induced draft fan, electronic equipment and storage medium

Info

Publication number: CN113007123A
Application number: CN202110250260.4A
Authority: CN
Inventors: 雷秀坚; 钟建伟; 白继亮; 莫红军; 周勇; 苏波; 倪政平
Original assignee: Sichuan Baima Circulating Fluidized Bed Demonstration Power Station Co ltd; National Energy Group Guoyuan Power Co Ltd
Current assignee: Sichuan Baima Circulating Fluidized Bed Demonstration Power Station Co ltd; National Energy Group Guoyuan Power Co Ltd
Priority date: 2021-03-08
Filing date: 2021-03-08
Publication date: 2021-06-22
Anticipated expiration: 2041-03-08
Also published as: CN113007123B

Abstract

The invention provides a method and a device for controlling an induced draft fan, electronic equipment and a storage medium. The control method of the induced draft fan comprises the following steps: acquiring a furnace negative pressure set value and a furnace negative pressure measured value; determining the target operation frequency of the frequency converter according to the hearth negative pressure preset value and the hearth negative pressure measured value; determining a target operation angle of the movable blade according to the target operation frequency and a corresponding relation between the frequency of the frequency converter and the angle of the movable blade, which is established in advance; and controlling the draught fan to operate according to the target operation frequency, and controlling the movable vane to rotate according to the target operation angle. According to the technical scheme of the embodiment of the invention, the induced draft fan can be controlled by two parameters of the target operation frequency of the frequency converter and the target operation angle of the movable blade determined according to the target operation frequency, and the target operation frequency and the target operation angle accord with the pre-established corresponding relation between the frequency converter and the movable blade angle, so that the safety, the stability and the economy of a working area where the induced draft fan is located are improved.

Description

Control method and device of induced draft fan, electronic equipment and storage medium

Technical Field

The document relates to the field of thermal automation control of large fluidized beds for thermal power generation, in particular to a control method and device of an induced draft fan, electronic equipment and a storage medium.

Background

The draught fan is an important auxiliary device of the circulating fluidized bed boiler, and smoke generated in the hearth of the boiler is introduced into the exhaust device by utilizing lifting force generated by rotation of the impeller, so that the negative pressure of the hearth is maintained within an allowable range, and the safe operation of the boiler is ensured.

In the prior art, under the control mode of controlling the draught fan simultaneously through converter and movable vane, the unit load of draught fan changes frequently, and large-scale circulating fluidized bed's furnace is bulky, and the operating mode is complicated in the stove, and furnace burning is undulant often, so boiler negative pressure fluctuation is frequent, in addition adjust the draught fan and adjust probably conflict to the draught fan through the movable vane through the converter respectively for the safety and the stability and the economic nature of the work area that the draught fan is located are relatively poor.

Disclosure of Invention

An embodiment of the present application aims to provide a method and an apparatus for controlling an induced draft fan, an electronic device, and a storage medium, so as to solve the problem of how to improve the safety, stability, and economy of a working area where the induced draft fan is located.

To solve the above technical problem, an embodiment of the present application is implemented as follows:

in a first aspect, an embodiment of the present application provides a method for controlling an induced draft fan, where the induced draft fan includes a frequency converter and a movable blade, and the method for controlling the induced draft fan includes:

acquiring a hearth negative pressure set value and a hearth negative pressure measured value of a boiler provided with the induced draft fan;

determining the target operation frequency of the frequency converter according to the hearth negative pressure preset value and the hearth negative pressure measured value;

determining a target operation angle of the movable blade according to the target operation frequency and a corresponding relation between a pre-established frequency converter frequency and a movable blade angle;

and controlling the induced draft fan to operate according to the target operation frequency, and controlling the movable blade to rotate according to the target operation angle.

In a second aspect, another embodiment of the present application provides a control device for an induced draft fan, where the induced draft fan includes a frequency converter and a movable blade, and includes:

the negative pressure acquisition module is used for acquiring a hearth negative pressure set value and a hearth negative pressure measured value of a boiler provided with the induced draft fan;

the frequency determination module is used for determining the target operation frequency of the frequency converter according to the hearth negative pressure preset value and the hearth negative pressure measured value;

the angle determining module is used for determining a target operating angle of the movable blade according to the target operating frequency and a corresponding relation between a pre-established frequency converter frequency and the movable blade angle;

and the draught fan control module is used for controlling the draught fan to operate according to the target operation frequency and controlling the movable blade to rotate according to the target operation angle.

In a third aspect, a further embodiment of the present application provides an electronic device, including a memory and a processor, where the memory stores computer-executable instructions, and when the computer-executable instructions are executed by the processor, the steps of the method for controlling an induced draft fan according to the first aspect may be implemented.

In a fourth aspect, a further embodiment of the present application provides a storage medium, where computer-executable instructions are stored in the storage medium, and when the computer-executable instructions are executed by a processor, the steps of the method for controlling an induced draft fan according to the first aspect may be implemented.

According to the technical scheme of the embodiment of the invention, firstly, a hearth negative pressure set value and a hearth negative pressure measured value of a boiler provided with an induced draft fan are obtained; then, determining the target operation frequency of the frequency converter according to the hearth negative pressure preset value and the hearth negative pressure measured value; secondly, determining a target operation angle of the movable blade according to the target operation frequency and a corresponding relation between the frequency of the frequency converter and the angle of the movable blade, which is established in advance; and finally, controlling the operation of the induced draft fan according to the target operation frequency, and controlling the rotation of the movable vane according to the target operation angle. According to the technical scheme of the embodiment of the invention, the induced draft fan can be controlled by two parameters of the target operation frequency of the frequency converter and the target operation angle of the movable blade determined according to the target operation frequency, and the target operation frequency and the target operation angle accord with the pre-established corresponding relation between the frequency converter and the movable blade angle, so that the safety, the stability and the economy of a working area where the induced draft fan is located are improved.

Drawings

In order to more clearly illustrate the technical solutions in one or more embodiments of the present application, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and it is obvious for a person skilled in the art to obtain other drawings based on these drawings without any creative effort.

Fig. 1 is a schematic flow chart of a method for controlling an induced draft fan according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of a control system of an induced draft fan according to an embodiment of the present disclosure;

FIG. 3 is a frequency angle graph reflecting a correspondence between a frequency converter frequency and a bucket angle according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of a control device of an induced draft fan according to an embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in one or more embodiments of the present application, the technical solutions in one or more embodiments of the present application will be clearly and completely described below with reference to the drawings in one or more embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments that can be derived by a person skilled in the art from one or more embodiments of the present application without inventive step shall fall within the scope of protection of this document.

Fig. 1 is a schematic flow chart of a method for controlling an induced draft fan according to an embodiment of the present application.

Referring to fig. 1, the method for controlling the induced draft fan includes step S102, step S104, step S106, and step S108. The control method of the induced draft fan is applied to the induced draft fan, and the induced draft fan comprises a frequency converter and a movable blade. A method of controlling the induced draft fan in the exemplary embodiment of fig. 1 will be described in detail below.

And S102, acquiring a hearth negative pressure set value and a hearth negative pressure measured value of the boiler provided with the induced draft fan.

The boiler may be a circulating fluidized bed boiler. Circulating fluidized bed boilers generally refer to combustion chambers operating in the form of a fluidized bed with a gas-solid separator at the outlet to return separated solids to the combustion apparatus of the combustion chamber.

The circulating fluidized bed boiler can effectively control the generation and the emission of SO2 and NOX in the combustion process, is a relatively clean combustion mode, has excellent emission characteristics and has obvious advantages in the aspect of pollution cost control. The induced draft fan is an important auxiliary device of the circulating fluidized bed boiler. With the development of the capacity maximization and ultralow emission control technology of the circulating fluidized bed, the power of the induced draft fan is continuously increased, and the requirements of safe starting and energy-saving operation of the induced draft fan are increased.

The boiler can also be other energy conversion equipment provided with an induced draft fan, the energy input to the boiler comprises chemical energy and electric energy in fuel, and the boiler outputs steam, high-temperature water or an organic heat carrier with certain heat energy.

In the combustion process of the boiler, under the condition of meeting sufficient air volume, the pressure in the furnace is maintained to be a constant value, and the operation is usually carried out at negative pressure (-19.6 to-49 Pa), namely the pressure is the negative pressure of the furnace. The negative pressure of the hearth is related to the safe and economic operation of the boiler. Too high pressure easily causes the dust to leak, has the danger that arouses the furnace explosion, and too low pressure then can cause fan power consumption to increase, and the loss of discharging fume increases.

The set value of the negative pressure in the furnace chamber may be a preset fixed value, a variable value that changes according to a preset change rule, or a negative pressure value in the furnace chamber that is determined according to a set value adjustment instruction after the set value adjustment instruction is obtained. The furnace negative pressure measurement value can be a furnace negative pressure value obtained by real-time measurement.

By acquiring a set value and a measured value of the negative pressure of the hearth, the fluctuation condition of the negative pressure of the hearth and the requirement of the negative pressure of the hearth can be determined.

Optionally, before determining the target operating frequency of the frequency converter according to the preset furnace negative pressure value and the measured furnace negative pressure value, the method further includes: acquiring an outlet negative pressure set value and an outlet negative pressure measured value of exhaust equipment of a boiler; judging whether a second comparison value between the outlet negative pressure set value and the outlet negative pressure measured value meets a preset negative pressure condition of the exhaust equipment or not; determining the target operation frequency of the frequency converter according to the hearth negative pressure preset value and the hearth negative pressure measured value, wherein the method comprises the following steps: and if the second comparison value meets the negative pressure condition of the exhaust equipment, determining the target operation frequency of the frequency converter according to the preset negative pressure value of the hearth and the measured negative pressure value of the hearth.

The exhaust equipment includes, but is not limited to, a stack and a desulfurizing tower, and the desulfurizing tower is hereinafter collectively described as an example.

Untreated flue gas discharged by the boiler enters from the bottom of the desulfurizing tower and is output from the top of the desulfurizing tower so as to carry out desulfurization treatment on the flue gas and realize the purpose of purifying the gas discharged by the boiler. The bottom of the desulfurizing tower can be regarded as the inlet of the desulfurizing tower, and the top of the desulfurizing tower can be regarded as the outlet of the desulfurizing tower.

In one embodiment, a set point and a measured value of negative pressure at the top of the desulfurization tower are obtained. Calculating a second comparison value between the negative pressure set value and the negative pressure measurement value, and then judging whether the second comparison value meets a preset negative pressure condition of the desulfurizing tower, for example, when the second comparison value is greater than a preset pressure threshold value, the negative pressure condition of the desulfurizing tower is not met; and when the second comparison value is smaller than the preset pressure threshold value, the negative pressure condition of the desulfurizing tower is met. The negative pressure condition of the desulfurizing tower can also be other preset conditions related to the negative pressure set value, the negative pressure measured value and the second comparison value at the top of the desulfurizing tower, which are not listed in the description. And when the second comparison value meets the negative pressure condition of the desulfurizing tower, determining the target operating frequency of the frequency converter according to the preset negative pressure value of the hearth and the measured negative pressure value of the hearth. And when the second comparison value does not meet the negative pressure condition of the desulfurizing tower, generating an override protection signal, and not executing the step of measuring the value according to the preset negative pressure value of the hearth and the negative pressure value of the hearth.

The override protection signal is used for protecting the safety of equipment, and can cross an automatic/manual operation station to lock (forbid increasing) the air door of the wind conveyor in the opening direction and lock (forbid decreasing) the air door of the induced draft fan in the closing direction; the air door of the induced draft fan can be closed (prohibited to be reduced) and opened (prohibited to be increased) beyond the automatic/manual operation station.

The method comprises the steps of obtaining an outlet negative pressure set value and an outlet negative pressure measured value of the exhaust equipment, judging whether a second comparison value between the outlet negative pressure set value and the outlet negative pressure measured value meets a preset exhaust equipment negative pressure condition, performing override protection on the equipment, and timely controlling the equipment to stop working and executing corresponding safety measures when the negative pressure of the exhaust equipment is abnormal.

In another embodiment, an example in which the exhaust apparatus is a desulfurizing tower will be described. During the bed building period or the bed withdrawing period of the desulfurizing tower, an inlet negative pressure set value and an inlet negative pressure measured value of the desulfurizing tower can be obtained; judging whether a third comparison value between the inlet negative pressure set value and the inlet negative pressure measured value meets a preset inlet negative pressure condition of the exhaust equipment or not; determining the target operation frequency of the frequency converter according to the hearth negative pressure preset value and the hearth negative pressure measured value, wherein the method comprises the following steps: and if the third comparison value meets the inlet negative pressure condition, determining the target operation frequency of the frequency converter according to the hearth negative pressure preset value and the hearth negative pressure measured value.

At the time outside the bed building period and the bed withdrawing period of the desulfurizing tower, the influence of the inlet negative pressure of the desulfurizing tower on the control of the induced draft fan can be ignored. By acquiring the inlet negative pressure set value and the inlet negative pressure measured value of the desulfurizing tower during the bed building period or the bed returning period of the desulfurizing tower and judging whether the third comparison value between the inlet negative pressure set value and the inlet negative pressure measured value meets the preset inlet negative pressure condition of the exhaust equipment, the safety and the stability of the equipment can be guaranteed during the bed building period and the bed returning period of the desulfurizing tower.

And step S104, determining the target operation frequency of the frequency converter according to the hearth negative pressure preset value and the hearth negative pressure measured value.

The target operating frequency refers to the operating frequency to which the frequency converter is expected to be tuned.

Optionally, determining a target operating frequency of the frequency converter according to the preset furnace negative pressure value and the measured furnace negative pressure value includes: calculating a first comparison value between a furnace negative pressure preset value and a furnace negative pressure measured value; and determining the target operation frequency of the frequency converter according to the first comparison value.

And calculating a difference value between the preset furnace negative pressure value and the measured furnace negative pressure value, namely a first comparison value, and determining the expected working frequency of the frequency converter according to the first comparison value.

And S106, determining the target operation angle of the movable blade according to the target operation frequency and the corresponding relation between the frequency of the frequency converter and the angle of the movable blade, which is established in advance.

The pre-established correspondence between the frequency of the frequency converter and the angle of the bucket may refer to a frequency angle graph as shown in fig. 3.

Fig. 3 is a frequency-angle graph reflecting a correspondence relationship between a frequency converter frequency and a bucket angle according to an embodiment of the present application.

Referring to fig. 3, if the abscissa of the frequency-angle graph is the frequency converter frequency and the ordinate is the bucket angle, the corresponding bucket angle can be read from the curve in the frequency-angle graph according to the frequency converter frequencies x1, x2, x3 and x 4. For example, the bucket angle corresponding to the frequency converter frequency x1 read from fig. 3 is y1 between a and b.

The frequency angle curve graph must be obtained by a frequency division test of the induced draft fan in a dynamic mode.

Optionally, the corresponding relationship between the frequency of the frequency converter and the angle of the movable blade is established in the following manner: acquiring a plurality of preset test frequency values of a frequency converter and a plurality of test angle values of the movable blade; combining the test frequency values and the test angle values pairwise to obtain a plurality of combination results; each combination result comprises a test frequency value and a test angle value; for each test frequency value, determining a plurality of to-be-processed combined results containing the test frequency value from a plurality of combined results; aiming at each combination result to be processed, acquiring the working efficiency of the induced draft fan and the unit load of the induced draft fan corresponding to the combination result to be processed; determining an optimal angle value corresponding to each test frequency value according to the working efficiency and the unit load; and establishing a corresponding relation between the frequency of the frequency converter and the angle of the movable blade according to each test frequency value and the corresponding optimal angle value.

A plurality of testing frequency values of the preset frequency converter, for example, a1 and a2, are obtained, and a plurality of testing angle values of the preset movable blade, for example, b1, b2 and b3 are obtained. The number of test frequency values and test angle values may be the same or different.

Combining the test frequency values and the test angle values in pairs to obtain a plurality of combination results, each combination result comprising a test frequency value and a test angle value, for example, combination result 1 is (a1, b1), combination result 2 is (a1, b2), combination result 3 is (a1, b3), combination result 4 is (a2, b1), combination result 5 is (a2, b2), and combination result 6 is (a2, b 3).

For each test frequency value, a plurality of to-be-processed combined results including the test frequency value is determined from the plurality of combined results, e.g., for test frequency value a2, the plurality of to-be-processed combined results includes: combination result 4(a2, b1), combination result 5(a2, b2), and combination result 6(a2, b 3).

For each to-be-processed combination result, the working efficiency of the induced draft fan and the unit load of the induced draft fan corresponding to the to-be-processed combination result are obtained, for example, for the combination result 4(a2, b1) in the to-be-processed combination result, the working efficiency and the unit load when the frequency converter of the induced draft fan is a2 and the angle of the movable blade is b1 are obtained. The working efficiency can be understood as the working capacity of the induced draft fan, and the effective power of the induced draft fan is higher when the working efficiency is high. The unit load can be understood as the energy loss of the unit of the induced draft fan in the operation process, and intuitively speaking, the unit can consume the electric quantity. The working efficiency and the unit load are obtained by adjusting parameters of the frequency converter and the movable blade according to each combination result of the induced draft fan, and then performing a frequency division test.

According to the working efficiency and the unit load, determining an optimal angle value corresponding to each test frequency value, wherein the optimal angle value is understood as comprehensively measuring the working efficiency and the unit load corresponding to each combination result to be processed aiming at each test frequency value, so that the optimal angle value which can take both the working efficiency and the unit load into consideration is determined in a plurality of test angle values. For example, a unified evaluation algorithm and an evaluation weight are preset for the working efficiency and the unit load respectively, an angle evaluation score of each combination result to be processed is calculated, and an optimal angle value is determined according to the angle evaluation scores.

According to the working efficiency and the unit load, the optimal angle value corresponding to each test frequency value is determined, the corresponding relation for controlling the induced draft fan is further established, the working efficiency and the unit load of the induced draft fan can be considered, the induced draft fan can guarantee high working efficiency in working, the unit load can be guaranteed to be low, and the economical efficiency of a working area where the induced draft fan is located is improved.

In one embodiment, in the frequency division test, the rotating speed of the induced draft fan is adjusted through the frequency converter, the full frequency band participates in negative pressure adjustment of the hearth, and the optimal angle value corresponding to each frequency of the frequency converter is obtained according to the dynamic performance test of the induced draft fan.

Optionally, before obtaining a plurality of preset test frequency values of the frequency converter and a plurality of preset test angle values of the movable blade, the method further includes: acquiring a plurality of preset frequency bands; setting a plurality of test frequency values located in each frequency band aiming at the frequency band; obtaining a plurality of preset test frequency values of the frequency converter, including: and acquiring a plurality of test frequency values positioned in each frequency band.

The frequency is divided into a plurality of frequency bands, for example, the frequency band 1 is 20-30 Hz, the frequency band 2 is 30-40 Hz, etc. For each frequency band, a plurality of test frequency values located in the frequency band are set, for example, the plurality of test frequency values located in the frequency band 1 include 20 hz, 22 hz, 24 hz, 26 hz, and 28 hz.

For each frequency band, a plurality of test frequency values located in the frequency band are obtained, for example, for frequency band 1, a plurality of test frequency values located in frequency band 1, namely 20 hz, 22 hz, 24 hz, 26 hz and 28 hz, are obtained.

And aiming at each frequency band, acquiring a plurality of test frequency values positioned in the frequency band, and further obtaining the working efficiency and the unit load of the induced draft fan through the test of the frequency division bands, so that the test result is closer to the working efficiency and the unit load of the induced draft fan in the normal working environment, and the accuracy of the optimal angle value corresponding to each test frequency value is improved.

And S108, controlling the induced draft fan to operate according to the target operation frequency, and controlling the movable blade to rotate according to the target operation angle.

The operation of the induced draft fan is controlled according to the target operation frequency, and the method can be understood as that the frequency of a frequency converter of the induced draft fan is adjusted to the target operation frequency, the induced draft fan operates under the condition that the frequency of the frequency converter is the target operation frequency, and the rotating speed of the induced draft fan changes along with the change of the frequency converter. And controlling the operation of the induced draft fan according to the target operation frequency, wherein the rotation speed of the induced draft fan is controlled by using the target operation frequency determined in the previous step.

The movable blade is controlled to rotate according to the target operation angle, and it can be understood that the movable blade rotates according to an angle originally, the movable blade angle of the movable blade is adjusted to the target operation angle, and then the movable blade rotates according to the target operation angle.

It should be emphasized that, in the aforementioned step 106, the time for determining the target operation angle of the movable blade is very short, so that the operation of the induced draft fan according to the target operation frequency and the rotation of the movable blade according to the target operation angle can be considered to be performed synchronously. That is, when the frequency of the frequency converter changes, the angle of the movable blade changes in real time along with the frequency, and at each time point, the frequency of the frequency converter and the angle of the movable blade both conform to the previously established correspondence between the frequency of the frequency converter and the angle of the movable blade. Instead of increasing or reducing the frequency of the frequency converter to a fixed value within a period of time and increasing or reducing the angle of the movable blade to a corresponding fixed value within a period of time.

Meanwhile, the induced draft fan is controlled through two parameters of the target operation frequency and the target operation angle, the two parameters conform to the pre-established corresponding relation between the frequency of the frequency converter and the angle of the movable blade, the conflict between the frequency converter adjustment and the movable blade adjustment can be avoided, and the stability and the safety of a working area where the induced draft fan is located are improved.

Optionally, after the induced draft fan is controlled to operate through the target operating frequency and the movable vane is controlled to rotate through the target operating angle, the control method of the induced draft fan further includes: when a fault of the frequency converter is detected, or when an angle adjusting instruction is obtained, the movable blade is controlled to rotate according to a first fixed angle, and the working frequency of the frequency converter is adjusted to a first fixed frequency; after the movable vane is controlled to rotate according to a first fixed angle for a first preset time, and under the condition that the working frequency is unchanged, the movable vane is controlled to rotate according to a first dynamic angle; the first dynamic angle is determined by the negative pressure of the furnace.

In order to meet the requirements of control modes such as 'working shear' and 'variable shear' of a frequency converter of an induced draft fan, the following control modes can be set:

a. normal frequency conversion adjustment mode: when the frequency converter is normal, automatically adjusting the frequency of the frequency converter of the induced draft fan according to the negative pressure requirement of the hearth, so that the rotating speed of the induced draft fan is changed, and the angle of the movable blade is adjusted according to the frequency of the frequency converter of the induced draft fan;

b. normal power frequency adjustment mode: under the power frequency running state, the frequency converter frequency remains unchanged, and according to the furnace negative pressure demand, the angle of the movable vane of whole journey automatically regulated draught fan.

Then switch the converter from the frequency conversion to the power frequency, include following two kinds of condition:

(1) frequency conversion fault switching mode: after the frequency converter breaks down, the angle of the movable blade is rapidly adjusted according to the angle preset value so as to meet the requirement of the rotating speed after the frequency converter is switched to the power frequency.

When the frequency converter is detected to be out of order, the movable blade is controlled to rotate according to a first fixed angle, and the working frequency of the frequency converter is adjusted to a first fixed frequency; after the movable vane is controlled to rotate according to a first fixed angle for a first preset time, and under the condition that the working frequency is unchanged, the movable vane is controlled to rotate according to a first dynamic angle; the first dynamic angle is determined by the negative pressure of the furnace.

It can be understood that the angle of the movable blade is fixed and unchanged in a period of time before the mode switching, and the working frequency of the frequency converter is the first fixed frequency, after the mode switching, the angle of the movable blade begins to change along with the hearth negative pressure, and the working frequency of the frequency converter is kept unchanged. The first fixed angle may be a preset fixed angle value of the bucket. The first preset time period may be a preset time period.

When detecting the converter trouble, for guaranteeing that the control of draught fan is not influenced by the converter of trouble, need switch into the power frequency with the frequency conversion. Before the mode switching of 'worker shear', the movable blade is controlled to rotate according to the first dynamic angle, and the induced draft fan can work stably before and after the mode switching.

(2) The frequency converter normally switches to a power frequency mode: and the operator adjusts the angle of the movable blade according to the working condition and sends a variable cutting instruction to the frequency converter.

When an angle adjusting instruction is obtained, the movable blade is controlled to rotate according to a first fixed angle, and the working frequency of the frequency converter is adjusted to a first fixed frequency; after the movable vane is controlled to rotate according to a first fixed angle for a first preset time, and under the condition that the working frequency is unchanged, the movable vane is controlled to rotate according to a first dynamic angle; the first dynamic angle is determined by the negative pressure of the furnace.

It can be understood that the angle of the movable blade is fixed and unchanged in a period of time before the mode switching, and the working frequency of the frequency converter is the first fixed frequency, after the mode switching, the angle of the movable blade begins to change along with the hearth negative pressure, and the working frequency of the frequency converter is kept unchanged. Before the mode switching of 'worker shear', the movable blade is controlled to rotate according to the first dynamic angle, and the induced draft fan can work stably before and after the mode switching.

Optionally, before obtaining a furnace negative pressure set value and a furnace negative pressure measured value of the boiler in which the induced draft fan is installed, the control method of the induced draft fan further includes: under the condition that the frequency converter operates according to a second fixed frequency and the movable blade rotates according to a second dynamic angle, acquiring a frequency converter mode adjusting instruction; the second dynamic angle is determined by the negative pressure of the hearth; and responding to the mode adjustment instruction of the frequency converter, and controlling the movable blade to rotate for a second preset time according to a second fixed angle.

Switching the frequency converter from frequency conversion to power frequency, namely, the power frequency shear frequency mode is as follows: under the power frequency running state, the angle of the movable blade is kept unchanged, and after the switching is completed, the angle of the movable blade changes along with the frequency of the frequency converter.

The method can be understood as that before mode switching, the movable blade is controlled to rotate according to a second fixed angle for a second preset time, at the moment, the angle of the movable blade is unchanged, and the frequency of the frequency converter is unchanged; after the mode is switched, the frequency of the frequency converter is changed, and the angle of the movable blade is changed along with the frequency of the frequency converter.

Before the mode switching of the variable cutting work, the movable blade is controlled to rotate for a second preset time according to a second fixed angle, and the induced draft fan can work stably before and after the mode switching of the variable cutting work.

According to the control method of the induced draft fan in the exemplary embodiment of fig. 1, first, a furnace negative pressure set value and a furnace negative pressure measured value of a boiler in which the induced draft fan is installed are obtained; then, determining the target operation frequency of the frequency converter according to the hearth negative pressure preset value and the hearth negative pressure measured value; secondly, determining a target operation angle of the movable blade according to the target operation frequency and a corresponding relation between the frequency of the frequency converter and the angle of the movable blade, which is established in advance; and finally, controlling the operation of the induced draft fan according to the target operation frequency, and controlling the rotation of the movable vane according to the target operation angle. According to the technical scheme of the embodiment of the invention, the induced draft fan can be controlled by two parameters of the target operation frequency of the frequency converter and the target operation angle of the movable blade determined according to the target operation frequency, and the target operation frequency and the target operation angle accord with the pre-established corresponding relation between the frequency converter and the movable blade angle, so that the safety, the stability and the economy of a working area where the induced draft fan is located are improved.

Fig. 2 is a schematic diagram of a method for controlling an induced draft fan according to an embodiment of the present application.

Referring to fig. 2, a set value 202 of the negative pressure of the furnace and a measured value 204 of the negative pressure of the furnace are obtained, and a first comparison value determined by the set value 202 of the negative pressure of the furnace and the measured value 204 of the negative pressure of the furnace is obtained. And obtaining an inlet negative pressure set value 206 and an inlet negative pressure measured value 208 of the desulfurizing tower, and obtaining a third comparison value determined by the inlet negative pressure set value 206 and the inlet negative pressure measured value 208.

And judging whether the third comparison value meets an inlet negative pressure condition 212, if so, acquiring an outlet negative pressure set value 210 and an outlet negative pressure measured value 212 of the desulfurizing tower to obtain a second comparison value determined by the outlet negative pressure set value 210 and the outlet negative pressure measured value 212, judging whether the second comparison value meets an outlet negative pressure condition 214, and if so, determining a first target operation frequency 216 and a second target operation frequency 220 according to the first comparison value.

A first target operating angle 218 is determined based on the first target operating frequency 216 and a pre-established correspondence between frequency converter frequency and bucket angle, and a second target operating angle 222 is determined based on the second target operating frequency 220 and a pre-established correspondence between frequency converter frequency and bucket angle.

The method comprises the steps of controlling the first induced draft fan to operate according to a first target operation frequency 216, controlling the movable blade of the first induced draft fan to rotate according to a first target operation angle 218, controlling the second induced draft fan to operate according to a second target operation frequency 220, and controlling the movable blade of the second induced draft fan to rotate according to a second target operation angle 222.

The control method of the induced draft fan in the embodiment shown in fig. 2 can realize each process in the embodiment of the control method of the induced draft fan, and achieve the same effect and function, which is not described herein again.

Fig. 4 is a schematic structural diagram of a control device of an induced draft fan according to an embodiment of the present application.

Referring to fig. 4, the induced draft fan includes converter and movable vane, and this induced draft fan's controlling means includes:

a negative pressure obtaining module 402, configured to obtain a furnace negative pressure set value and a furnace negative pressure measured value of a boiler in which an induced draft fan is installed;

a frequency determining module 404, configured to determine a target operating frequency of the frequency converter according to the preset furnace negative pressure value and the measured furnace negative pressure value;

the angle determining module 406 is configured to determine a target operating angle of the movable blade according to the target operating frequency and a correspondence between a frequency of a frequency converter and a movable blade angle, which is established in advance;

and the draught fan control module 408 is used for controlling the draught fan to operate according to the target operation frequency and controlling the movable blade to rotate according to the target operation angle.

In some embodiments of the present invention, based on the above scheme, the correspondence between the frequency of the frequency converter and the angle of the bucket is established as follows:

acquiring a plurality of preset test frequency values of a frequency converter and a plurality of test angle values of the movable blade;

combining the test frequency values and the test angle values pairwise to obtain a plurality of combination results; each combination result comprises a test frequency value and a test angle value;

for each test frequency value, determining a plurality of to-be-processed combined results containing the test frequency value from a plurality of combined results;

aiming at each combination result to be processed, acquiring the working efficiency of the induced draft fan and the unit load of the induced draft fan corresponding to the combination result to be processed;

determining an optimal angle value corresponding to each test frequency value according to the working efficiency and the unit load;

and establishing a corresponding relation between the frequency of the frequency converter and the angle of the movable blade according to each test frequency value and the corresponding optimal angle value.

In some embodiments of the present invention, based on the above scheme, the method further includes:

acquiring a plurality of preset frequency bands;

setting a plurality of test frequency values located in each frequency band aiming at the frequency band;

obtaining a plurality of preset test frequency values of the frequency converter, including:

and acquiring a plurality of test frequency values positioned in each frequency band.

In some embodiments of the present invention, based on the foregoing scheme, the frequency determining module 404 is specifically configured to:

calculating a first comparison value between a furnace negative pressure preset value and a furnace negative pressure measured value;

and determining the target operation frequency of the frequency converter according to the first comparison value.

In some embodiments of the present invention, based on the above scheme, the control device of the induced draft fan further includes:

the variable cutting switching module is used for controlling the movable blade to rotate according to a first fixed angle when detecting that the frequency converter breaks down or acquiring an angle adjusting instruction, and adjusting the working frequency of the frequency converter to the first fixed frequency;

the power frequency control module is used for controlling the movable vane to rotate according to a first dynamic angle after controlling the movable vane to rotate according to a first fixed angle for a first preset time and under the condition that the working frequency is unchanged; the first dynamic angle is determined by the negative pressure of the furnace.

the instruction acquisition module is used for acquiring a mode adjustment instruction of the frequency converter under the condition that the frequency converter operates according to a second fixed frequency and the movable blade rotates according to a second dynamic angle; the second dynamic angle is determined by the negative pressure of the hearth;

and the working shear conversion module is used for responding to the mode adjustment instruction of the frequency converter and controlling the movable blade to rotate for a second preset time according to a second fixed angle.

the outlet negative pressure acquisition module is used for acquiring an outlet negative pressure set value and an outlet negative pressure measured value of exhaust equipment of the boiler;

the condition judgment module is used for judging whether a second comparison value between the outlet negative pressure set value and the outlet negative pressure measured value meets the preset negative pressure condition of the exhaust equipment or not;

the frequency determining module 404 is specifically configured to:

and if the second comparison value meets the negative pressure condition of the exhaust equipment, determining the target operation frequency of the frequency converter according to the preset negative pressure value of the hearth and the measured negative pressure value of the hearth.

In one embodiment of the application, firstly, a hearth negative pressure set value and a hearth negative pressure measured value of a boiler provided with an induced draft fan are obtained; then, determining the target operation frequency of the frequency converter according to the hearth negative pressure preset value and the hearth negative pressure measured value; secondly, determining a target operation angle of the movable blade according to the target operation frequency and a corresponding relation between the frequency of the frequency converter and the angle of the movable blade, which is established in advance; and finally, controlling the operation of the induced draft fan according to the target operation frequency, and controlling the rotation of the movable vane according to the target operation angle. According to the technical scheme of the embodiment of the invention, the induced draft fan can be controlled by two parameters of the target operation frequency of the frequency converter and the target operation angle of the movable blade determined according to the target operation frequency, and the target operation frequency and the target operation angle accord with the pre-established corresponding relation between the frequency converter and the movable blade angle, so that the safety, the stability and the economy of a working area where the induced draft fan is located are improved.

The control device of the induced draft fan in fig. 4 can implement each process in the embodiment of the control method of the induced draft fan, and achieve the same effect and function, which is not described herein again.

Further, an embodiment of the present application further provides an electronic device, fig. 5 is a schematic structural diagram of the electronic device provided in an embodiment of the present application, and as shown in fig. 5, the electronic device includes: memory 501, processor 502, bus 503, and communication interface 504. The memory 501, processor 502, and communication interface 504 communicate via bus 503. communication interface 504 may include input and output interfaces including, but not limited to, a keyboard, mouse, display, microphone, and the like.

In fig. 5, the memory 501 has stored thereon computer-executable instructions that, when executed by the processor 502, implement the following flow:

acquiring a hearth negative pressure set value and a hearth negative pressure measured value of a boiler provided with an induced draft fan;

determining a target operation angle of the movable blade according to the target operation frequency and a corresponding relation between the frequency of the frequency converter and the angle of the movable blade, which is established in advance;

and controlling the draught fan to operate according to the target operation frequency, and controlling the movable vane to rotate according to the target operation angle.

Optionally, when the computer executable instructions are executed by the processor 502, the correspondence between the frequency of the frequency converter and the angle of the blade is established as follows:

Optionally, before obtaining a plurality of preset test frequency values of the frequency converter and a plurality of test angle values of the bucket when the computer-executable instructions are executed by the processor 502, the method further includes:

acquiring a plurality of preset frequency bands;

Optionally, when executed by the processor 502, the computer executable instruction determines the target operating frequency of the frequency converter according to the preset furnace negative pressure value and the measured furnace negative pressure value, including:

Optionally, when executed by the processor 502, the computer-executable instructions, after controlling the induced draft fan to operate through the target operation frequency and controlling the movable blade to rotate through the target operation angle, further include:

when a fault of the frequency converter is detected, or when an angle adjusting instruction is obtained, the movable blade is controlled to rotate according to a first fixed angle, and the working frequency of the frequency converter is adjusted to a first fixed frequency;

after the movable vane is controlled to rotate according to a first fixed angle for a first preset time, and under the condition that the working frequency is unchanged, the movable vane is controlled to rotate according to a first dynamic angle; the first dynamic angle is determined by the negative pressure of the furnace.

Optionally, when executed by the processor 502, before obtaining a furnace negative pressure set value and a furnace negative pressure measured value of the boiler in which the induced draft fan is installed, the computer-executable instructions further include:

under the condition that the frequency converter operates according to a second fixed frequency and the movable blade rotates according to a second dynamic angle, acquiring a frequency converter mode adjusting instruction; the second dynamic angle is determined by the negative pressure of the hearth;

and responding to the mode adjustment instruction of the frequency converter, and controlling the movable blade to rotate for a second preset time according to a second fixed angle.

Optionally, before determining the target operating frequency of the frequency converter according to the preset furnace negative pressure value and the measured furnace negative pressure value, the method further includes:

acquiring an outlet negative pressure set value and an outlet negative pressure measured value of exhaust equipment of a boiler;

judging whether a second comparison value between the outlet negative pressure set value and the outlet negative pressure measured value meets a preset negative pressure condition of the exhaust equipment or not;

determining the target operation frequency of the frequency converter according to the hearth negative pressure preset value and the hearth negative pressure measured value, wherein the method comprises the following steps:

The electronic device provided by the embodiment of the application can realize each process in the control method embodiment of the induced draft fan, and achieve the same functions and effects, and the processes are not repeated here.

Further, another embodiment of the present application also provides a storage medium having stored therein computer-executable instructions, which when executed by the processor 502, implement the following process:

acquiring a plurality of preset frequency bands;

Optionally, when executed by the processor 502, before determining the target operating frequency of the frequency converter according to the preset furnace negative pressure value and the measured furnace negative pressure value, the computer-executable instructions further include:

The storage medium includes a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk.

The storage medium provided by the embodiment of the application can realize each process in the control method embodiment of the induced draft fan, and achieve the same function and effect, and is not repeated here.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention 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 invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams 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 a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include forms of volatile memory in a computer readable medium, Random Access Memory (RAM) and/or non-volatile memory, such as Read Only Memory (ROM) or flash memory (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 computer storage media 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 magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.

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 an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

As will be appreciated by one skilled in the art, 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 above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to 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 scope of the claims of the present application.

Claims

1. The control method of the induced draft fan comprises a frequency converter and a movable blade, and is characterized by comprising the following steps of:

2. The method according to claim 1, characterized in that the correspondence between the frequency converter frequency and the bucket angle is established by:

obtaining a plurality of preset test frequency values of the frequency converter and a plurality of preset test angle values of the movable blade;

combining the plurality of test frequency values and the plurality of test angle values pairwise to obtain a plurality of combination results; each of said combined results including one of said test frequency values and one of said test angle values;

3. The method of claim 2, further comprising, prior to the obtaining a preset plurality of test frequency values for the frequency converter and a plurality of test angle values for the bucket:

acquiring a plurality of preset frequency bands;

the obtaining of the preset multiple test frequency values of the frequency converter includes:

and acquiring a plurality of test frequency values positioned in each frequency band aiming at each frequency band.

4. The method of claim 1, wherein determining the target operating frequency of the frequency converter according to the preset furnace negative pressure value and the measured furnace negative pressure value comprises:

calculating a first comparison value between the preset furnace negative pressure value and the measured furnace negative pressure value;

5. The method of claim 1, wherein after the induced draft fan is controlled to operate through the target operation frequency and the movable blade is controlled to rotate through the target operation angle, the method further comprises the following steps:

when the frequency converter is detected to have a fault or when an angle adjusting instruction is obtained, controlling the movable blade to rotate according to a first fixed angle, and adjusting the working frequency of the frequency converter to a first fixed frequency;

after the movable blade is controlled to rotate according to a first fixed angle for a first preset time, and under the condition that the working frequency is unchanged, the movable blade is controlled to rotate according to a first dynamic angle; the first dynamic angle is determined by the negative pressure of the furnace.

6. The method of claim 1, wherein before the obtaining of the set value and the measured value of the negative pressure of the furnace of the boiler in which the induced draft fan is installed, the method further comprises:

acquiring a mode adjusting instruction of the frequency converter under the condition that the frequency converter operates according to a second fixed frequency and the movable blade rotates according to a second dynamic angle; the second dynamic angle is determined by the negative pressure of the hearth;

and responding to the frequency converter mode adjusting instruction, and controlling the movable blade to rotate for a second preset time according to a second fixed angle.

7. The method of claim 1, wherein before the determining the target operating frequency of the frequency converter according to the preset furnace pressure value and the measured furnace pressure value, further comprises:

acquiring an outlet negative pressure set value and an outlet negative pressure measured value of exhaust equipment of the boiler;

determining the target operation frequency of the frequency converter according to the preset furnace negative pressure value and the measured furnace negative pressure value, wherein the step of determining the target operation frequency of the frequency converter comprises the following steps:

and if the second comparison value meets the negative pressure condition of the exhaust equipment, determining the target operation frequency of the frequency converter according to the preset furnace negative pressure value and the measured furnace negative pressure value.

8. The utility model provides a controlling means of draught fan, the draught fan includes converter and movable vane, its characterized in that includes:

9. An electronic device, comprising a memory and a processor, the memory having stored thereon computer-executable instructions that, when executed by the processor, are capable of implementing the steps of the method of controlling an induced draft fan according to any one of the preceding claims 1 to 7.

10. A storage medium having stored therein computer-executable instructions, which when executed by a processor, are capable of implementing the steps of the method of controlling an induced draft fan according to any one of claims 1 to 7.