CN115681956A

CN115681956A - Opposed combustion boiler and starting method thereof, pulverized coal adjusting system and pulverized coal adjusting method

Info

Publication number: CN115681956A
Application number: CN202211149706.5A
Authority: CN
Inventors: 滕浩; 顾江峰; 周献东; 朱波; 郏锦文
Original assignee: Huaneng Taicang Power Generation Co Ltd
Current assignee: Huaneng Taicang Power Generation Co Ltd
Priority date: 2022-09-21
Filing date: 2022-09-21
Publication date: 2023-02-03

Abstract

The invention relates to the technical field of power station boilers, in particular to an opposed combustion boiler, a starting method, a pulverized coal adjusting system and an adjusting method, wherein the opposed combustion boiler is positioned in burner groups at the lowest layers of a front wall and a rear wall, and each burner group is correspondingly connected with an outlet pulverized coal pipe of a coal mill; the combustor groups are positioned above the lowermost layers of the front wall and the rear wall, and the combustor groups positioned on the same layer are in mixed cross connection with outlet pulverized coal pipes of two different coal mills; the pulverized coal conditioning system comprises: the controller can control the opening of the throttle ring according to the data acquired by the data acquisition device so as to control the flow of the pulverized coal of the outlet pulverized coal pipe. The method aims to solve the problems of asymmetric flames in the opposed firing boiler, uneven distribution of heat load in the boiler, and large deviation of steam temperature and wall temperature in the boiler under the conditions that the front wall and the rear wall are put into operation and different coal mills are used for combustion.

Description

Opposed firing boiler and starting method thereof, and pulverized coal adjusting system and adjusting method

Technical Field

The invention relates to the technical field of power station boilers, in particular to a hedging combustion boiler and a starting method thereof, and a pulverized coal adjusting system and a pulverized coal adjusting method.

Background

At present, china is a big country for coal-fired power generation, and the safety and the economy of the operation of a coal-fired boiler are always the key points of the work of a large number of electric power patent workers.

The 600MW boiler combustion equipment of a certain power plant is arranged for the front and back wall, adopts hedging combustion, spiral-flow type combustor, and the front wall three-layer combustor is from supreme A layer, B layer, the E layer of being in proper order down, and the back wall three-layer combustor is from supreme F layer, D layer, the C layer of being in proper order down, and the coal bed combustor arranges 6 buggy pipes, sees figure 1. The inventor finds that when the number of coal mills in operation is singular due to different coal powder for each coal mill, the number of layers of the coal powder in operation on the front wall and the rear wall of the opposed combustion boiler is different, so that flame asymmetry often occurs, and the problems of uneven distribution of heat load, large deviation of steam temperature on two sides and large wall temperature deviation in the boiler are caused, and the economical efficiency is poor. On the other hand, when two homonymy coal pulverizer trouble or shut down, the front and back wall coal powder layer number of piles of commissioning will become 3, and flame deflection is more serious this moment, is unfavorable for unit safety operation. Therefore, the opposed combustion boiler and the starting method thereof, and the pulverized coal adjusting system and the pulverized coal adjusting method thereof are designed, and a series of improvements are made on the starting method and the pulverized coal adjusting method thereof according to the structural arrangement of the opposed combustion boiler with the front wall and the rear wall.

Disclosure of Invention

The invention aims to provide an opposed firing boiler and a starting method thereof, a pulverized coal adjusting system and an adjusting method thereof, which are used for solving the problems of asymmetric flame in the opposed firing boiler, uneven distribution of heat load in the boiler, and large deviation of steam temperature and wall temperature in the boiler under the conditions of different numbers of coal mills operated by front and rear walls and different types of coal used for combustion in the background art.

The invention provides an opposed combustion boiler, which is provided with a front wall and a rear wall which are oppositely arranged, wherein the front wall and the rear wall are respectively provided with a plurality of layers of burner groups, each layer of burner group comprises a plurality of burners which are uniformly arranged at intervals along the horizontal direction, the burners are respectively communicated with a plurality of coal mills through outlet pulverized coal pipes, the plurality of coal mills convey pulverized coal to the burners through the outlet pulverized coal pipes, the burner groups positioned at the lowest layers of the front wall and the rear wall, and each burner group is correspondingly connected with the outlet pulverized coal pipe of one coal mill; and the burner groups are positioned above the lowermost layers of the front wall and the rear wall, and the burner groups positioned on the same layer are in mixed cross connection with outlet pulverized coal pipes of two different coal mills.

Furthermore, the opposed firing boiler is provided with three burner groups of a bottom layer, a middle layer and a top layer, and each burner group of the front wall and the rear wall is provided with six burners; the multiple coal mills are respectively a coal mill A, a coal mill B, a coal mill C, a coal mill D, a coal mill E and a coal mill F: the outlet pulverized coal pipes corresponding to the coal mill A are respectively as follows: an outlet pulverized coal pipe A1, an outlet pulverized coal pipe A2, an outlet pulverized coal pipe A3, an outlet pulverized coal pipe A4, an outlet pulverized coal pipe A5 and an outlet pulverized coal pipe A6; the outlet pulverized coal pipes corresponding to the coal mill B are respectively as follows: an outlet pulverized coal pipe B1, an outlet pulverized coal pipe B2, an outlet pulverized coal pipe B3, an outlet pulverized coal pipe B4, an outlet pulverized coal pipe B5 and an outlet pulverized coal pipe B6; the outlet pulverized coal pipes corresponding to the coal mill C are respectively as follows: an outlet pulverized coal pipe C1, an outlet pulverized coal pipe C2, an outlet pulverized coal pipe C3, an outlet pulverized coal pipe C4, an outlet pulverized coal pipe C5 and an outlet pulverized coal pipe C6; the outlet pulverized coal pipes corresponding to the coal mill D are respectively as follows: an outlet pulverized coal pipe D1, an outlet pulverized coal pipe D2, an outlet pulverized coal pipe D3, an outlet pulverized coal pipe D4, an outlet pulverized coal pipe D5 and an outlet pulverized coal pipe D6; the outlet pulverized coal pipes corresponding to the coal mill E are respectively as follows: an outlet pulverized coal pipe E1, an outlet pulverized coal pipe E2, an outlet pulverized coal pipe E3, an outlet pulverized coal pipe E4, an outlet pulverized coal pipe E5 and an outlet pulverized coal pipe E6; the outlet pulverized coal pipes corresponding to the coal mill F are respectively as follows: an outlet pulverized coal pipe F1, an outlet pulverized coal pipe F2, an outlet pulverized coal pipe F3, an outlet pulverized coal pipe F4, an outlet pulverized coal pipe F5 and an outlet pulverized coal pipe F6; the combustor on the top layer of the front wall is sequentially connected with an outlet pulverized coal pipe E1, an outlet pulverized coal pipe C1, an outlet pulverized coal pipe E2, an outlet pulverized coal pipe C2, an outlet pulverized coal pipe E3 and an outlet pulverized coal pipe C3; the burner on the top layer of the rear wall is sequentially connected with an outlet pulverized coal pipe C4, an outlet pulverized coal pipe E4, an outlet pulverized coal pipe C5, an outlet pulverized coal pipe E5, an outlet pulverized coal pipe C6 and an outlet pulverized coal pipe E6; the burner at the middle layer of the front wall is sequentially connected with an outlet pulverized coal pipe B1, an outlet pulverized coal pipe D1, an outlet pulverized coal pipe B2, an outlet pulverized coal pipe D2, an outlet pulverized coal pipe B3 and an outlet pulverized coal pipe D3; the combustor in the middle layer of the rear wall is sequentially connected with an outlet pulverized coal pipe D4, an outlet pulverized coal pipe B4, an outlet pulverized coal pipe D5, an outlet pulverized coal pipe B5, an outlet pulverized coal pipe D6 and an outlet pulverized coal pipe B6; the burner at the bottom layer of the front wall is sequentially connected with an outlet pulverized coal pipe A1, an outlet pulverized coal pipe A2, an outlet pulverized coal pipe A3, an outlet pulverized coal pipe A4, an outlet pulverized coal pipe A5 and an outlet pulverized coal pipe A6; the burner at the bottom of the rear wall is sequentially connected with an outlet pulverized coal pipe F1, an outlet pulverized coal pipe F2, an outlet pulverized coal pipe F3, an outlet pulverized coal pipe F4, an outlet pulverized coal pipe F5 and an outlet pulverized coal pipe F6.

The invention also provides a method for starting the opposed combustion boiler, which comprises the following steps:

step 1: starting a coal mill F;

and 2, step: starting a coal mill A;

and step 3: starting a coal mill B or a coal mill D;

and 4, step 4: starting the coal mill which is not started in the step 3;

and 5: and starting the coal mill C or the coal mill E.

Further, in the step 1, a plasma igniter is adopted as the ignition mode of the coal mill F.

The present invention also provides a pulverized coal adjusting system for an opposed firing boiler, the adjusting system comprising:

the flow velocity sensor is arranged on the outlet pulverized coal pipe and is used for collecting the pulverized coal flow velocity of the outlet pulverized coal pipe;

the throttling ring is arranged on one side of the outlet pulverized coal pipe, which is far away from the flow velocity sensor, and is used for adjusting the pulverized coal flow of the outlet pulverized coal pipe;

the data acquisition device is used for acquiring data of the flow velocity sensor;

and the controller is configured to be in communication connection with the data acquisition device and the throttle ring, and controls the opening of the throttle ring according to the data acquired by the data acquisition device so as to control the flow of the pulverized coal of the outlet pulverized coal pipe.

The invention also provides a coal powder adjusting method for the coal powder adjusting system, which comprises the following steps:

acquiring average volatile components Vdaf0 of coal for burning of six coal mills;

presetting the average flow velocity of outlet pulverized coal pipes of six coal mills as a first preset value, and presetting a feedforward control function f (x) according to the first preset value and the average volatile component Vdaf0;

acquiring an average value V0 output by the flow velocity sensor of the single coal mill according to output values V1-V6 of the flow velocity sensor on the coal powder pipe corresponding to the outlet of the single coal mill;

and calculating whether the first deviation ratio of the average value V0 and the output value of the feedforward control function f (x) is smaller than a second preset value, if so, not correcting the average value V0, otherwise, correcting the average value V0 to V0= f (x) by using the feedforward control function.

Further, the method also includes:

and acquiring whether a second deviation ratio of the output value of the flow velocity sensor on the outlet pulverized coal pipe of the single coal mill and the VO is smaller than a third preset value, if so, maintaining the opening degree of the throttling ring unchanged, otherwise, automatically adjusting the corresponding throttling ring until the second deviation ratio is within the third preset value.

Further, the method also includes:

acquiring the feedforward average flow speed of a single coal mill corresponding to the operating load of the opposed combustion boiler as a first preset value according to the operating load of the opposed combustion boiler;

obtaining the volatile components Vdaf1-Vdaf6 of coal powder for burning six coal mills;

and obtaining a feedforward control function f (x) = a first preset value (1 + (Vdafx-Vdaf 0)/Vdaf 0), wherein x in the feedforward control function f (x) takes a value of 1-6.

The present invention also provides an electronic device, including: a processor and a memory communicatively coupled to the processor; wherein the memory stores instructions executable by the processor to enable the processor to perform the steps of the startup method and the coal fines conditioning method.

The present invention also provides a computer-readable storage medium having stored thereon a program for implementing a startup method and a pulverized coal adjusting method, the program for implementing the startup method and the pulverized coal adjusting method being executed by a processor to implement the steps of the startup method and the steps of the pulverized coal adjusting method.

The beneficial effects of the invention include:

1. the combination mode and the starting method of the burners on the opposed firing boiler provided by the invention have the advantages that through the burner groups positioned at the lowest layers of the front wall and the rear wall, each burner group is correspondingly connected with the outlet pulverized coal pipe of one coal mill, so that the concentrated and stable combustion of flame can be ensured when the unit is started at a low-load stage, and sufficient pulverized coal is provided for the boiler; the burner groups positioned above the lowest layers of the front wall and the rear wall, the burner group positioned on the same layer and the outlet pulverized coal pipes of two different coal mills are mixed and connected in a cross way, so that the flame in the boiler can still be uniformly and symmetrically distributed under the condition that the pulverized coal used by the multiple coal mills is different, and further, the steam temperature and the wall temperature deviation in the boiler are reduced; if certain coal pulverizer that the combustor group of lower floor top is connected breaks down, the condition that certain one side does not have the buggy and drops into can not appear, still can guarantee good combustion effect in the boiler in the furnace.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and it will be apparent to those skilled in the art that other relevant drawings can be obtained based on the drawings without inventive effort.

FIG. 1 is a schematic view of the arrangement of the upper outlet pulverized coal pipe of a opposed firing boiler according to the prior art provided by the present invention;

FIG. 2 is a schematic diagram of the arrangement of the outlet pulverized coal pipes of the improved opposed firing boiler provided by the embodiment of the present invention;

FIG. 3 is a flowchart of a booting method according to an embodiment of the present invention;

fig. 4 is a schematic view of an installation structure of a pulverized coal adjusting system according to an embodiment of the present invention;

FIG. 5 is a schematic system diagram of a pulverized coal conditioning system according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a coal fines conditioning method provided by an embodiment of the present invention;

FIG. 7 is a flow chart illustrating coal fines conditioning in a coal pulverizer F according to an embodiment of the present invention;

FIG. 8 is a schematic representation of operational data of an opposed firing boiler before modification provided by an embodiment of the present invention;

FIG. 9 is a schematic representation of operational data for an improved opposed firing boiler provided in accordance with an embodiment of the present invention;

FIG. 10 is a schematic diagram of experimental data before and after application provided by an embodiment of the present invention;

icon: 1-a flow rate sensor; 2-a throttle ring.

Detailed Description

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

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Meanwhile, in the description of the present invention, the terms "first", "second", and the like are used only for distinguishing the description, and are not to be construed as indicating or implying relative importance.

The combination mode and the starting method of the burners on the opposed firing boiler provided by the embodiment of the invention have the advantages that by the burner groups positioned at the lowest layers of the front wall and the rear wall, each burner group is correspondingly connected with the outlet pulverized coal pipe of one coal mill, so that the concentrated and stable combustion of flame can be ensured when the unit is started at a low-load stage, and sufficient pulverized coal is provided for the boiler; the burner groups positioned above the lowest layers of the front wall and the rear wall, the burner group positioned on the same layer and the outlet pulverized coal pipes of two different coal mills are mixed and connected in a cross way, so that the flame in the boiler can still be uniformly and symmetrically distributed under the condition that the pulverized coal used by the multiple coal mills is different, and further, the steam temperature and the wall temperature deviation in the boiler are reduced; if a certain coal mill connected with the burner group above the lowest layer fails, the condition that no coal powder is fed into a certain side can not occur, and a good combustion effect in the boiler can still be ensured in the hearth; it will be understood by those skilled in the art that the delivery of pulverized coal from the coal mill to the corresponding outlet pulverized coal pipe represents normal operation of the coal mill.

FIG. 2 is a schematic view of the arrangement of the outlet pulverized coal pipe of the improved opposed firing boiler provided by the embodiment of the present invention;

for example, as shown in fig. 2, the opposed firing boiler is provided with three burner groups of a bottom layer, a middle layer and a top layer, and each burner group of the front wall and the rear wall is provided with six burners; the multiple coal mills are respectively a coal mill A, a coal mill B, a coal mill C, a coal mill D, a coal mill E and a coal mill F: the outlet pulverized coal pipes corresponding to the coal mill A are respectively as follows: an outlet pulverized coal pipe A1, an outlet pulverized coal pipe A2, an outlet pulverized coal pipe A3, an outlet pulverized coal pipe A4, an outlet pulverized coal pipe A5 and an outlet pulverized coal pipe A6; the outlet pulverized coal pipes corresponding to the coal mill B are respectively as follows: an outlet pulverized coal pipe B1, an outlet pulverized coal pipe B2, an outlet pulverized coal pipe B3, an outlet pulverized coal pipe B4, an outlet pulverized coal pipe B5 and an outlet pulverized coal pipe B6; the outlet pulverized coal pipes corresponding to the coal mill C are respectively as follows: an outlet pulverized coal pipe C1, an outlet pulverized coal pipe C2, an outlet pulverized coal pipe C3, an outlet pulverized coal pipe C4, an outlet pulverized coal pipe C5 and an outlet pulverized coal pipe C6; the outlet pulverized coal pipes corresponding to the coal mill D are respectively as follows: an outlet pulverized coal pipe D1, an outlet pulverized coal pipe D2, an outlet pulverized coal pipe D3, an outlet pulverized coal pipe D4, an outlet pulverized coal pipe D5 and an outlet pulverized coal pipe D6; the outlet pulverized coal pipes corresponding to the coal mill E are respectively as follows: an outlet pulverized coal pipe E1, an outlet pulverized coal pipe E2, an outlet pulverized coal pipe E3, an outlet pulverized coal pipe E4, an outlet pulverized coal pipe E5 and an outlet pulverized coal pipe E6; the outlet pulverized coal pipes corresponding to the coal mill F are respectively as follows: an outlet pulverized coal pipe F1, an outlet pulverized coal pipe F2, an outlet pulverized coal pipe F3, an outlet pulverized coal pipe F4, an outlet pulverized coal pipe F5 and an outlet pulverized coal pipe F6; the burner on the top layer of the front wall is sequentially connected with an outlet pulverized coal pipe E1, an outlet pulverized coal pipe C1, an outlet pulverized coal pipe E2, an outlet pulverized coal pipe C2, an outlet pulverized coal pipe E3 and an outlet pulverized coal pipe C3; the burner on the top layer of the rear wall is sequentially connected with an outlet pulverized coal pipe C4, an outlet pulverized coal pipe E4, an outlet pulverized coal pipe C5, an outlet pulverized coal pipe E5, an outlet pulverized coal pipe C6 and an outlet pulverized coal pipe E6; the burner at the middle layer of the front wall is sequentially connected with an outlet pulverized coal pipe B1, an outlet pulverized coal pipe D1, an outlet pulverized coal pipe B2, an outlet pulverized coal pipe D2, an outlet pulverized coal pipe B3 and an outlet pulverized coal pipe D3; the burner at the middle layer of the rear wall is sequentially connected with an outlet pulverized coal pipe D4, an outlet pulverized coal pipe B4, an outlet pulverized coal pipe D5, an outlet pulverized coal pipe B5, an outlet pulverized coal pipe D6 and an outlet pulverized coal pipe B6; the combustor at the bottom layer of the front wall is sequentially connected with an outlet pulverized coal pipe A1, an outlet pulverized coal pipe A2, an outlet pulverized coal pipe A3, an outlet pulverized coal pipe A4, an outlet pulverized coal pipe A5 and an outlet pulverized coal pipe A6; the combustor at the bottom of the rear wall is sequentially connected with an outlet pulverized coal pipe F1, an outlet pulverized coal pipe F2, an outlet pulverized coal pipe F3, an outlet pulverized coal pipe F4, an outlet pulverized coal pipe F5 and an outlet pulverized coal pipe F6;

in the above embodiment, since the unit is just connected to the grid, the coal pulverizer F needs to be started preferentially, and therefore, in order to ensure stable concentrated combustion of flame when the unit is in a low-load state, outlet pulverized coal pipes corresponding to the coal pulverizer a and the coal pulverizer F are arranged in a concentrated manner on the same side without crossing, so as to ensure the concentration of pulverized coal.

as shown in fig. 1, the pulverized coal pipes at the top layer of the front wall in the prior art sequentially include: e1, E2, E3, E4, E5, E6; the pulverized coal pipes on the top layer of the rear wall are sequentially as follows: c1, C2, C3, C4, C5, C6; the coal powder pipe in the middle layer of the front wall sequentially comprises the following components from left to right: b1, B2, B3, B4, B5, B6; the coal powder pipe in the middle layer of the rear wall sequentially comprises the following components from left to right: d1, D2, D3, D4, D5, D6; the pulverized coal pipe at the bottom layer of the front wall sequentially comprises the following components from left to right: a1, A2, A3, A4, A5 and A6; the pulverized coal pipe at the bottom layer of the rear wall sequentially comprises the following components from left to right: f1, F2, F3, F4, F5, F6; taking an opposed firing boiler before improvement as an example, if coal powder is fired by a coal mill B and a coal mill D which are different, outlet coal powder pipes of the improved coal mill B and the improved coal mill D are respectively arranged on a front wall middle layer and a rear wall middle layer, and at the moment, because the coal powder is fired differently, flame in the boiler cannot be guaranteed to be uniform and symmetrical, so that the steam temperature and wall temperature deviation in the boiler are larger; similarly, taking the coal mill B and the coal mill D before improvement as an example, if the coal mill B or the coal mill D is shut down during the operation of the unit, no pulverized coal is output on one side of the front wall or the rear wall, and the whole unit needs to be shut down to ensure the safety of the unit.

The invention also provides a starting method for the opposed firing boiler, which comprises the following steps: step 1: starting a coal mill F; and 2, step: starting a coal mill A, wherein the principle is that the coal mill A and the coal mill F are positioned at the bottom layer, and the front wall and the rear wall are arranged in opposite impact, so that combustion can be mutually supported, and flame is kept not to deflect; and step 3: starting a coal mill B or a coal mill D; and 4, step 4: starting the coal mill which is not started in the step 3; and 5: and starting the coal mill C or the coal mill E.

the starting method shown in fig. 3 can be understood as that the bottom layer, the middle layer and the top layer are started in sequence, and the amplification ensures the stable concentration of flame in the hearth to the maximum extent.

For example, the plasma igniter is adopted in the ignition mode of the coal mill F in the step 1, in this embodiment, the coal mills except the coal mill F all adopt oil guns to support combustion, the coal mill F is started as the first station, the flame concentration needs to be ensured, and the plasma igniter is adopted to realize more stable ignition.

The present invention also provides a pulverized coal conditioning system for an opposed firing boiler, the conditioning system comprising: the flow velocity sensor 1 is arranged on the outlet pulverized coal pipe and is used for collecting the pulverized coal flow velocity of the outlet pulverized coal pipe; the throttle ring 2 is arranged on one side of the outlet pulverized coal pipe, which is far away from the flow velocity sensor 1, and is used for adjusting the pulverized coal flow of the outlet pulverized coal pipe; the data acquisition device is used for acquiring data of the flow velocity sensor 1; and the controller is configured to be in communication connection with the data acquisition device and the throttle ring 2, and controls the opening of the throttle ring 2 according to the data acquired by the data acquisition device so as to control the flow rate of the pulverized coal of the outlet pulverized coal pipe.

FIG. 4 is a schematic view of an installation structure of a pulverized coal conditioning system according to an embodiment of the present invention;

as shown in fig. 4 and 5, in the pulverized coal adjusting system for an opposed firing boiler according to the embodiment of the present invention, the controller may be implemented as an electronic chip having data processing capability, such as a single chip microcomputer or a microcontroller, the flow rate sensor 1 and the throttle ring 2 are both mounted on the outlet pulverized coal pipe through bolts, and a plurality of preset values are preset in the controller in advance to serve as reference values for adjusting the opening degree of the throttle ring 2; for example, the controller is configured to set a feed-forward opening degree value and a feed-forward difference preset value of each of the chokes 2 in advance according to the unit operation load, calculate a difference between an actual opening degree and a feed-forward opening degree of each of the chokes 2 when the unit is operating, and adjust the actual opening degree of each of the chokes 2 according to a comparison result between the difference and the feed-forward difference preset value.

For example, unlike the above embodiment, the controller may be further configured to obtain the difference between the actual opening degree of the throttle ring 2 of the coal mill in operation and the feed-forward opening degree value by stopping one or more coal mills located at the middle and upper floors, as the basis for adjusting the opening degree of the throttle ring 2 after the coal mill is stopped.

The invention also provides a pulverized coal adjusting method for the pulverized coal adjusting system, which comprises the following steps:

s100, obtaining average volatile component Vdaf0 of coal types for burning six coal mills,

s120, presetting the average flow velocity of outlet pulverized coal pipes of six coal mills to be a first preset value, and presetting a feedforward control function f (x) according to the first preset value and the average volatile component Vdaf0;

s130, acquiring an average value V0 output by the flow velocity sensor 1 of the single coal mill according to the output values V1-V6 of the flow velocity sensor 1 on the outlet pulverized coal pipe corresponding to the single coal mill;

s140, calculating whether a first deviation ratio between the average value V0 and the output value of the feedforward control function f (x) is smaller than a second preset value, if so, not correcting the average value V0, otherwise, correcting to V0= f (x) by using the feedforward control function.

According to the coal powder adjusting method provided by the invention, different coal types are combusted by a plurality of coal mills, the influence of the volatile content in different coal types on combustion is referred, the characteristic of average volatile content of the plurality of coal mills is introduced to be used as a reference function for feedforward adjustment of the outlet coal powder pipe, and the average flow speed of the outlet coal powder pipe of a single coal mill is introduced to be used as a reference for feedback adjustment of the outlet coal powder pipe, so that the response speed of the coal mills for providing coal powder for the boiler is increased, and the stability of flame combustion in the boiler can be well maintained.

Further, the method further comprises: and (3) acquiring whether a second deviation ratio of the output value of the flow velocity sensor 1 and the VO on the coal powder outlet pipe of the single coal mill is smaller than a third preset value, if so, maintaining the opening degree of the throttle ring 2 unchanged, otherwise, automatically adjusting the corresponding throttle ring 2 until the second deviation ratio is within the third preset value.

Further, the method further comprises: acquiring the feedforward average flow speed of a single coal mill corresponding to the operating load of the opposed combustion boiler as a first preset value according to the operating load of the opposed combustion boiler; obtaining the volatile components Vdaf1-Vdaf6 of coal powder for burning six coal mills; obtaining a feedforward control function f (x) = a first preset value (1 + (Vdafx-Vdaf 0)/Vdaf 0), wherein x in the feedforward control function f (x) takes a value of 1-6; for example, the average flow speed of a certain coal mill of the unit under the rated load in this embodiment is 25.5m/s, i.e., f (x) =25.5 (1 + (Vdafx-Vdaf 0)/Vdaf 0), where the value of x corresponds to the number of the coal mill.

in the coal dust adjusting method for the coal dust adjusting system provided in the above embodiment, the second preset value is preferably 3%, and the third preset value is preferably 5% in this embodiment, and a coal dust adjusting flow of a coal mill is described below by taking the coal mill F as an example, and coal dust adjusting flows of the remaining coal mills are consistent with the principle of the coal mill F, and coal dust adjustment of the remaining coal mills can be achieved by referring to the coal mill F, which is not described in detail herein; as shown in fig. 7, after the opposed combustion boiler is operated, whether the coal mill F is operated is monitored, and if the coal mill F is in a normal operation state, the following steps are performed:

monitoring the output values of the flow velocity sensors 1 on the coal powder pipes F1-F6 at the outlet of the coal mill F to obtain VF1-VF6;

calculating the average value of VF1-VF6 to obtain the average flow velocity VF of a pulverized coal pipe at the outlet F of the coal mill;

calculating a first deviation ratio of the VF and the output value of the feedforward control function f (x), and comparing the first deviation ratio with a second preset value mentioned in the above embodiment, where the value of the second preset value is 3%, specifically:

if the first deviation rate is less than or equal to 3% or less than 0%, the average flow speed VF of the coal mill F is in a normal range;

if the first deviation rate is not within the range, the average flow speed of the coal mill F is abnormal, and the system controller corrects VF so that VF = F (x);

after the value of VF is normal, the next step is performed, and second deviation ratios of VF1 to VF6 and VF are calculated respectively and compared with the third preset value mentioned in the above embodiment, where the value of the third preset value is 5%, specifically:

if the second deviation rate is less than or equal to 5% and more than or equal to 0%, the opening degree of the throttle ring 2 is unchanged;

if the second deviation rate is not in the range, adjusting the corresponding outlet pulverized coal pipe throttling ring 2 until the second deviation rate is kept in a normal range;

through the technical scheme, the coal pulverizer F realizes the quick adjustment of the coal pulverizer F outlet pulverized coal pipe through the combination of feedforward control and feedback control in the operation process, so that the coal pulverizer F outlet pulverized coal pipe is always kept in a normal working state, and the stability in the boiler of the unit is further improved.

as shown in fig. 8, the data in the table are data parameters before the unit is modified under the working condition of 450MW load, before the modification, the deviation rate from the average wind speed of the outlet pulverized coal pipe No. 1 of the coal mill a, the outlet pulverized coal pipe No. 1 of the coal mill B, the outlet pulverized coal pipe No. 5 of the coal mill C, the outlet pulverized coal pipe No. 4 of the coal mill D, the outlet pulverized coal pipe No. 5 of the coal mill D, the outlet pulverized coal pipe No. 1 of the coal mill E, the outlet pulverized coal pipe No. 3 of the coal mill E, the outlet pulverized coal pipe No. 4 of the coal mill F, and the outlet pulverized coal pipe No. 5 of the coal mill F all exceeds 5%, at this time, the combustion effect in the hearth is not good, and the thermal deviation is large.

as shown in fig. 9, the data in the table is data parameters of the unit after being modified under the working condition of load 450MW, after being modified, the coal mill a, the coal mill B, the coal mill C, the coal mill D, the coal mill E and the coal mill F, and after being adjusted according to the pulverized coal adjusting method provided by the present disclosure, the wind speed deviation of the pulverized coal pipe at the outlet of each coal mill can be effectively controlled within 5%, the combustion effect in the improved hearth is significantly improved, and the thermal deviation is reduced.

as shown in FIG. 10, the steam temperatures at two sides of the boiler which are shielded, too high and too high are taken as inspection parameters under the condition that the operation of four units of 350WM, 420WM, 510WM and 600WM of the opposed combustion boiler meets the requirement:

the steam temperature deviation of the screen outlet, the screen outlet height and the screen outlet height of the front-wall and rear-wall opposed-combustion boiler is about 10-20 ℃, for example: when the load of the unit is 350WM before modification, the steam temperature deviation between the outlet A of the screen and the outlet B of the screen is 15 ℃, and the steam temperature higher than the outlet A of the screen and the steam temperature higher than the outlet B of the screen are 12 ℃;

after the transformation, because the buggy pipe cross arrangement on middle level and upper strata, including buggy governing system's regulation for flame distributes evenly in the furnace, the combustion stability, and the screen is crossed the export, is high to be crossed the export, the high equal effective control of export again steam temperature deviation is within 10 ℃, for example: when the load of the unit is 350WM after modification, the deviation between the temperature of the steam passing through the outlet A and the temperature of the steam passing through the outlet B is 5 ℃, and the deviation between the temperature of the steam passing through the outlet A and the temperature of the steam passing through the outlet B is 2 ℃, so that the modified effect is very obvious.

In addition to the above description, there are the following points to be explained:

(1) The drawings of the embodiments of the disclosure only relate to the structures related to the embodiments of the disclosure, and other structures can refer to common designs;

(2) Without conflict, embodiments of the present disclosure and features of the embodiments may be combined with each other to arrive at new embodiments.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. Opposed firing boiler, opposed firing boiler have with relative front wall and the back wall that sets up, be equipped with multilayer combustor group on front wall and the back wall respectively, every layer combustor group includes a plurality of combustors along the even interval arrangement of horizontal direction, the combustor communicates with many coal mills through exporting the buggy pipe respectively, and many coal mills carry buggy, its characterized in that to the combustor through exporting the buggy pipe:

the combustor groups are positioned at the lowermost layers of the front wall and the rear wall, and each combustor group is correspondingly connected with an outlet pulverized coal pipe of one coal mill;

and the burner groups are positioned above the lowermost layers of the front wall and the rear wall, and the burner groups positioned on the same layer are in mixed cross connection with outlet pulverized coal pipes of two different coal mills.

2. The opposed firing boiler according to claim 1, wherein the opposed firing boiler is provided with three burner groups of a bottom layer, a middle layer and a top layer, and six burners are provided for each burner group of the front and rear walls;

the multiple coal mills are respectively a coal mill A, a coal mill B, a coal mill C, a coal mill D, a coal mill E and a coal mill F:

the outlet pulverized coal pipes corresponding to the coal mill A are respectively as follows: an outlet pulverized coal pipe A1, an outlet pulverized coal pipe A2, an outlet pulverized coal pipe A3, an outlet pulverized coal pipe A4, an outlet pulverized coal pipe A5 and an outlet pulverized coal pipe A6;

the outlet pulverized coal pipes corresponding to the coal mill B are respectively as follows: an outlet pulverized coal pipe B1, an outlet pulverized coal pipe B2, an outlet pulverized coal pipe B3, an outlet pulverized coal pipe B4, an outlet pulverized coal pipe B5 and an outlet pulverized coal pipe B6;

the outlet pulverized coal pipes corresponding to the coal mill C are respectively as follows: an outlet pulverized coal pipe C1, an outlet pulverized coal pipe C2, an outlet pulverized coal pipe C3, an outlet pulverized coal pipe C4, an outlet pulverized coal pipe C5 and an outlet pulverized coal pipe C6;

the outlet pulverized coal pipes corresponding to the coal mill D are respectively as follows: an outlet pulverized coal pipe D1, an outlet pulverized coal pipe D2, an outlet pulverized coal pipe D3, an outlet pulverized coal pipe D4, an outlet pulverized coal pipe D5 and an outlet pulverized coal pipe D6;

the outlet pulverized coal pipes corresponding to the coal mill E are respectively as follows: an outlet pulverized coal pipe E1, an outlet pulverized coal pipe E2, an outlet pulverized coal pipe E3, an outlet pulverized coal pipe E4, an outlet pulverized coal pipe E5 and an outlet pulverized coal pipe E6;

the outlet pulverized coal pipes corresponding to the coal mill F are respectively as follows: an outlet pulverized coal pipe F1, an outlet pulverized coal pipe F2, an outlet pulverized coal pipe F3, an outlet pulverized coal pipe F4, an outlet pulverized coal pipe F5 and an outlet pulverized coal pipe F6;

the burner on the top layer of the front wall is sequentially connected with an outlet pulverized coal pipe E1, an outlet pulverized coal pipe C1, an outlet pulverized coal pipe E2, an outlet pulverized coal pipe C2, an outlet pulverized coal pipe E3 and an outlet pulverized coal pipe C3;

the burner on the top layer of the rear wall is sequentially connected with an outlet pulverized coal pipe C4, an outlet pulverized coal pipe E4, an outlet pulverized coal pipe C5, an outlet pulverized coal pipe E5, an outlet pulverized coal pipe C6 and an outlet pulverized coal pipe E6;

the burner at the middle layer of the front wall is sequentially connected with an outlet pulverized coal pipe B1, an outlet pulverized coal pipe D1, an outlet pulverized coal pipe B2, an outlet pulverized coal pipe D2, an outlet pulverized coal pipe B3 and an outlet pulverized coal pipe D3;

the burner at the middle layer of the rear wall is sequentially connected with an outlet pulverized coal pipe D4, an outlet pulverized coal pipe B4, an outlet pulverized coal pipe D5, an outlet pulverized coal pipe B5, an outlet pulverized coal pipe D6 and an outlet pulverized coal pipe B6;

the combustor at the bottom layer of the front wall is sequentially connected with an outlet pulverized coal pipe A1, an outlet pulverized coal pipe A2, an outlet pulverized coal pipe A3, an outlet pulverized coal pipe A4, an outlet pulverized coal pipe A5 and an outlet pulverized coal pipe A6;

the burner at the bottom of the rear wall is sequentially connected with an outlet pulverized coal pipe F1, an outlet pulverized coal pipe F2, an outlet pulverized coal pipe F3, an outlet pulverized coal pipe F4, an outlet pulverized coal pipe F5 and an outlet pulverized coal pipe F6.

3. A method for starting up a opposed combustion boiler, for use in a opposed combustion boiler according to claim 2, characterized by comprising the steps of:

step 1: starting a coal mill F;

step 2: starting a coal mill A;

and step 3: starting a coal mill B or a coal mill D;

and 4, step 4: starting the coal mill which is not started in the step 3;

and 5: and starting the coal mill C or the coal mill E.

4. The starting method according to claim 3, wherein the coal pulverizer F in step 1 is ignited by a plasma igniter.

5. Pulverized coal conditioning system for a opposed firing boiler according to any of claims 1 to 2, comprising:

6. The pulverized coal conditioning method for the opposed firing system of claim 5, characterized by comprising the steps of:

7. The method for conditioning pulverized coal as claimed in claim 6, further comprising:

8. The method for conditioning pulverized coal as claimed in claim 6, further comprising:

9. An electronic device, characterized in that the electronic device comprises: a processor and a memory communicatively coupled to the processor; wherein the memory stores instructions executable by the processor to enable the processor to perform the steps of the start-up method of claims 3 to 4 and the steps of the coal fines conditioning method of claims 6 to 8.

10. A computer-readable storage medium, characterized in that a program implementing a startup method and a pulverized coal adjusting method, which are executed by a processor to implement the steps of the startup method of claims 3 to 4 and the steps of the pulverized coal adjusting method of claims 6 to 8, is stored thereon.