CN-121994657-A - Multi-branch pulverized coal granularity monitoring integrated system and control method thereof

CN121994657ACN 121994657 ACN121994657 ACN 121994657ACN-121994657-A

Abstract

The application belongs to a monitoring method, and provides a multi-branch coal powder granularity monitoring integrated system and a control method thereof, aiming at the technical problems of insufficient real-time performance, poor sample representativeness, easy abrasion and failure of a sensor, higher cost and easy occurrence of sample cross interference and data distortion of the existing coal powder fineness monitoring method. The closed-loop feedback mechanism based on the real-time shading rate is adopted, so that self-adaptive cleaning is realized, the purging efficiency is optimized, and the energy consumption of compressed air is reduced. By means of the one-control-multiple architecture of multipath parallel sample injection and one-path series detection, hardware investment is reduced, monitoring coverage rate is remarkably improved, and operation cost of a power plant is reduced. The whole system improves the accuracy and economy of pulverized coal granularity monitoring, and is suitable for high-efficiency pulverized coal monitoring of coal-fired power plants.

Inventors

LV ZHAOMIN
ZHANG ZHUOYUAN
GUAN HONGLIANG
ZHU GUANGYAO
WANG HUI
LI LAIFU
CHEN TAO
ZHANG XIAO
CHEN RENBO
HUANG CHANGYU
QIU YANGSEN
TAN JINGKAO
XU SHENG
ZHOU ZIXU
CHEN JUNMING
ZHANG CHANGQING
Weng Xiaowen
FU LIANG
HUANG CHANGYUE
LIN HE
TIAN CHEN
LUO RUI
MO SHI
CHEN HUADONG
WU TAO

Assignees

西安热工研究院有限公司
华能海南发电股份有限公司海口电厂
西安西热电站信息技术有限公司

Dates

Publication Date: 20260508
Application Date: 20260327

Claims (10)

1. The multi-branch pulverized coal granularity monitoring integrated system is characterized by comprising a main control unit (7), a central converging valve group (2), a gas-solid separation unit (3), a three-way reversing unit (4), a granularity detection unit (5), a purging power unit (6), a main control unit (7) and a plurality of groups of sampling branches (1), wherein the central converging valve group, the gas-solid separation unit (3), the three-way reversing unit (4), the granularity detection unit (5) and the purging power unit (6) are respectively electrically connected with the main control unit (7); The input ends of a plurality of groups of sampling branches (1) are respectively communicated with an external primary air pipe, and the output ends of a plurality of groups of sampling branches (1) are respectively correspondingly communicated with a plurality of sample inlets of the central converging valve group (2); The first channel of the three-way reversing unit is connected with the output end of the gas-solid separation unit (3), the second channel is connected with the purging power unit (6), and the third channel is connected with the granularity detection unit.
2. The multi-branch pulverized coal granularity monitoring integrated system according to claim 1, wherein the plurality of groups of sampling branches (1) comprise sampling devices arranged on a primary air pipe and a conveying pipeline for connecting the sampling devices with a sample inlet of the central converging valve group (2).
3. The multi-branch pulverized coal granularity monitoring integrated system according to claim 1, wherein each sample inlet of the central converging valve group (2) is provided with an electromagnetic opening and closing valve independently controlled by the main control unit (7).
4. The multi-branch pulverized coal granularity monitoring integrated system according to claim 1, wherein the top of the gas-solid separation unit (3) is connected with a waste gas return pipeline, and the tail end of the waste gas return pipeline is led back into an external primary air pipe; The ash storage and discharge valve controlled by the main control unit (7) is arranged at the ash collecting hopper at the bottom of the gas-solid separation unit (3).
5. The multi-branch pulverized coal granularity monitoring integrated system according to claim 1, wherein the three-way reversing unit (4) is a reversing valve controlled by the main control unit (7) and is used for switching the sample injection conducting state of the granularity detecting unit (5) and the gas-solid separating unit (3) or switching the purging conducting state of the purging power unit (6) and the public pipeline.
6. A control method of a multi-branch pulverized coal granularity monitoring integrated system, which is applied to the multi-branch pulverized coal granularity monitoring integrated system as claimed in any one of claims 1 to 5, and is characterized by comprising: s1, a sampling branch (1) with a designated serial number and a sample inlet of a corresponding central converging valve group (2) are opened through a main control unit (7), so that coal dust enters a granularity detection unit (5) for granularity data acquisition after passing through a gas-solid separation unit (3); S2, closing a sample inlet corresponding to the central converging valve group (2) through the main control unit (7); S3, controlling the three-way reversing unit (4) to be communicated with the purging power unit (6) through the main control unit (7) and starting the purging power unit (6), purging the front side of the granularity detection unit (5), separating out exhaust gas and residual powder from the gas-solid separation unit (3), and discharging the exhaust gas and residual powder back into the corresponding primary air pipe; S4, continuously judging whether the opening condition of the next group of sampling branches (1) is met or not in a public path through a main control unit (7) to finish cross-branch switching, wherein the public path comprises a flow path from a central confluence valve group (2) to a granularity detection unit (5).
7. The method for controlling the multi-branch pulverized coal granularity monitoring integrated system according to claim 6, further comprising, before step S1: And the main control unit (7) is used for calling real-time shading rate data of the granularity detection unit (5), and if the shading rate is higher than a preset background threshold value, the purging power unit (6) is started to purge the front end of the granularity detection unit until the shading rate is reduced to be smaller than or equal to the preset background threshold value.
8. The control method of the multi-branch pulverized coal granularity monitoring integrated system according to claim 6, wherein the method for separating the exhaust gas and the residual powder from the gas-solid separation unit (3) comprises the step of discharging the separated exhaust gas and the separated residual powder back into the primary air pipe by opening an ash storage and discharge valve at the bottom of the gas-solid separation unit (3).
9. The method according to claim 6, wherein in step S4, the starting condition includes: Whether a particulate residue signal is detected in the common path, and if no particulate residue signal is detected and the shading rate is reset, the next set of sampling branches (1) is allowed to be started.
10. The control method of the multi-branch pulverized coal granularity monitoring integrated system according to claim 6, wherein the granularity detection unit (5) adopts a full-range laser diffraction method and a Mie light scattering theory for measurement.

Description

Multi-branch pulverized coal granularity monitoring integrated system and control method thereof Technical Field The application belongs to a monitoring method, and particularly relates to a multi-branch pulverized coal granularity monitoring integrated system and a control method thereof. Background In the current power generation system, the coal-fired unit frequently participates in deep peak regulation under the background of energy structure adjustment and power system operation mode change, and the coal fines have important influence on the combustion stability, burnout degree and pollutant emission of the boiler, but the conventional means are difficult to realize timely, accurate and stable monitoring on the coal fines granularity state under the rapid variable working conditions. The existing pulverized coal fineness monitoring mode mainly comprises an offline screening method and an online monitoring method, wherein the offline screening method is used for drying, screening and weighing after manual periodic sampling, and the online monitoring method comprises a fixed single-point sampling, one-pipe one-machine configuration and an integration scheme of a multi-point shared detector. According to the scheme, the offline screening method has time lag and is easily influenced by manual operation, sample representativeness and consistency are poor, a representative sample reflecting full-section characteristics is difficult to obtain by fixed single-point sampling in a high-speed gas-solid two-phase flow environment, measurement deviation is large, a sensor is subjected to high-speed dust scouring and is easy to wear and lose efficacy for a long time, the primary assembly and operation and maintenance cost of a one-pipe one-machine mode is high, and the problems of sample cross interference and data tailing distortion caused by insufficient coal dust deposition and purification control of a public pipeline also exist in the multi-point sharing detector scheme, so that the accuracy and reliability of a monitoring result are influenced. Disclosure of Invention Aiming at the technical problems of insufficient real-time performance, poor sample representativeness, easy abrasion and failure of a sensor, higher cost and easy occurrence of sample cross interference and data distortion of the traditional pulverized coal fineness monitoring method, the application provides a multi-branch pulverized coal granularity monitoring integrated system and a control method thereof. In order to achieve the above purpose, the application is realized by adopting the following technical scheme: In a first aspect, the application provides a multi-branch pulverized coal granularity monitoring integrated system, which comprises a main control unit, the central converging valve group, the gas-solid separation unit, the three-way reversing unit, the granularity detection unit, the purging power unit, the main control unit and the multiple groups of sampling branches are respectively and electrically connected with the main control unit; The input ends of a plurality of groups of sampling branches are respectively communicated with an external primary air pipe, and the output ends of a plurality of groups of sampling branches are respectively correspondingly communicated with a plurality of sample inlets of the central converging valve group; the first channel of the three-way reversing unit is connected with the output end of the gas-solid separation unit, the second channel is connected with the purging power unit, and the third channel is connected with the granularity detection unit. Further, the multiple groups of sampling branches comprise sampling devices installed on the primary air pipe and conveying pipelines connected with the sampling devices and the central converging valve group sample inlets. Further, each sample inlet of the central converging valve group is provided with an electromagnetic opening and closing valve independently controlled by the main control unit. Further, the top of the gas-solid separation unit is connected with a waste gas return pipeline, and the tail end of the waste gas return pipeline is led back into an external primary air pipe; and an ash storage and discharge valve controlled by the main control unit is arranged at the ash collecting hopper at the bottom of the gas-solid separation unit. Further, the three-way reversing unit is a reversing valve controlled by the main control unit and is used for switching the sample injection conducting state of the granularity detecting unit and the gas-solid separating unit or switching the purging conducting state of the purging power unit and the public pipeline. In a second aspect, the present application provides a control method of a multi-branch pulverized coal granularity monitoring integrated system, which is applied to the multi-branch pulverized coal granularity monitoring integrated system, and includes: S1, a sampling branch with a de