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CN-121977981-A - Fixed source condensable particulate matter online monitoring system and application method

CN121977981ACN 121977981 ACN121977981 ACN 121977981ACN-121977981-A

Abstract

The invention discloses a fixed source condensable particulate matter on-line monitoring system and a using method thereof. The system comprises a condensation sampling unit, a concentration unit, a reagent supply unit, a spectrophotometry detection unit and a data processing and control unit. The condensing sampling unit extracts and condenses the flue gas to obtain condensable particulate matter condensate, the condensing unit actively condenses the condensate through heating and negative pressure to obtain high-concentration liquid to be detected, the reagent supply unit quantitatively supplies the liquid to be detected and the reaction reagent to the spectrophotometry detection unit, the spectrophotometry detection unit detects target ions in the liquid to be detected by spectrophotometry and outputs signals, the data processing and control unit cooperatively controls the units, and the concentration of the condensable particulate matter is calculated based on the detection signals. The concentration of the liquid to be detected is improved through concentration pretreatment, the high sensitivity of a spectrophotometry is combined, the detection signal intensity and the signal to noise ratio are enhanced, the problems of weak on-line monitoring signals and poor accuracy caused by excessive dilution of a sample are solved, and the high-accuracy and high-sensitivity on-line real-time monitoring of the fixed-source condensable particles is realized.

Inventors

  • WANG GANG
  • ZHANG HUANHUAN
  • HU HAIZHU
  • GUO XIAOLEI
  • ZHANG FUYIN

Assignees

  • 雪城数智科技(河南)有限公司

Dates

Publication Date
20260505
Application Date
20260323

Claims (10)

  1. 1. A fixed source condensable particulate matter on-line monitoring system, comprising: The condensation sampling unit is used for extracting flue gas containing condensable particles from a fixed source and condensing the flue gas to obtain condensable particle condensate; the concentrating unit is connected with the condensing sampling unit and is used for receiving and concentrating the condensable particulate condensate to obtain a concentrated liquid to be measured; the spectrophotometry detection unit is connected with the concentration unit, detects target ions in the liquid to be detected by spectrophotometry, and outputs detection signals related to the concentration of the target ions; A reagent supply unit connected between the concentration unit and the spectrophotometry detection unit for quantitatively supplying the liquid to be detected and at least one reaction reagent into the spectrophotometry detection unit for reaction; the data processing and control unit is respectively in communication connection with the condensation sampling unit, the concentration unit, the reagent supply unit and the spectrophotometry detection unit, and is used for controlling the operation flow of the system and calculating the concentration of the condensable particles based on the detection signals.
  2. 2. The fixed source condensable particulate matter on-line monitoring system according to claim 1, wherein the concentration unit comprises a concentration container (11) and a vacuum pump (10), the concentration container (11) is used for containing condensable particulate matter condensate, a heating element is arranged on the concentration container (11), the vacuum pump (10) is communicated with the concentration container (11) through an atmosphere balance valve (9), and a first liquid level meter (12) and a temperature sensor (14) are arranged on the concentration container (11).
  3. 3. The fixed source condensable particulate matter online monitoring system according to claim 2, wherein the bottom of the concentration container (11) is connected with a nitrogen gas source (17), and a flowmeter (16) is arranged between the nitrogen gas source (17) and the concentration container (11).
  4. 4. A fixed source condensable particulate matter on-line monitoring system according to claim 3, characterized in that the outside of the concentration vessel (11) is provided with a first radiator fan (13).
  5. 5. The online monitoring system for condensable particulate matters of a fixed source according to any one of claims 1 to 4, wherein the spectrophotometric detection unit comprises a reaction vessel (30), a light source, and a detector, wherein monochromatic light emitted by the light source passes through the reaction vessel (30), and the detector detects the intensity of light transmitted through the reaction vessel (30) and generates a detection signal.
  6. 6. The online monitoring system for condensable particulate matters of a fixed source according to claim 5, wherein the reagent supply unit comprises a multi-position valve (18) and a metering tube (19), the channels of the multi-position valve (18) are respectively connected with the concentration container (11), the metering tube (19), the reaction container (30), the standard liquid source (22), the waste liquid container (23), the second cleaning liquid source (24) and at least one reagent liquid source, the metering tube (19) is provided with a second liquid level meter (20), and the metering tube (19) is communicated with a third peristaltic pump (21).
  7. 7. The fixed source condensable particulate matter on-line monitoring system according to claim 1 or 6, wherein the condensation sampling unit comprises a sampling probe (1), a condenser (6) and a sampling pump (8), the sampling pump (8) is used for extracting smoke through the sampling probe (1), the smoke collected by the sampling probe (1) is conveyed to the condenser (6) through a heat tracing sampling pipe (2), and the smoke forms condensable particulate matter condensate under the action of the condenser (6).
  8. 8. The fixed source condensable particulate matter online monitoring system of claim 7, wherein the inlet of the condenser (6) is in communication with the first source of cleaning fluid (5) through a first peristaltic pump (4).
  9. 9. The fixed source condensable particulate matter online monitoring system of claim 8, wherein the cleaning fluids of the first cleaning fluid source (5) and the second cleaning fluid source (24) are deionized water.
  10. 10. A method of using the fixed source condensable particulate on-line monitoring system of any one of claims 1-9, comprising the steps of: Sampling and condensing and collecting, namely extracting flue gas containing condensable particles from a fixed source through a condensing sampling unit, condensing, collecting to obtain condensable particle condensate, and introducing the collected condensable particle condensate into a condensing unit; Step 2, collecting residual condensate, starting a first peristaltic pump (4), introducing the cleaning liquid in the first cleaning liquid source (5) into a condenser (6) to clean the residual condensate in the pipeline, and then introducing the cleaning liquid and the residual condensate into a concentration container (11) of a concentration unit; Step 3, concentrating pretreatment, namely opening an atmosphere balance valve (9) and a nitrogen source (17), controlling the flow rate of nitrogen by using a flowmeter (16), and purging condensate in a concentrating container (11); Step 4, condensing condensate, opening a vacuum pump (10), closing an atmospheric balance valve (9), continuously introducing nitrogen, wherein the extraction rate of the vacuum pump (10) is always larger than the nitrogen introduction rate, opening a heating element in a condensing unit, heating the condensate under the negative pressure condition, evaporating and condensing the condensate in a condensing container (11), and discharging steam generated by condensation along with the nitrogen through the vacuum pump (10) to obtain condensed liquid to be detected; step 5, spectrophotometry detection, wherein the reagent supply unit quantitatively introduces the liquid to be detected and at least one reaction reagent into the spectrophotometry detection unit, and the spectrophotometry detection unit detects target ions in the liquid to be detected based on spectrophotometry to obtain detection data related to the concentration of the target ions; And 6, data processing, namely calculating the concentration of the condensable particles based on the obtained detection data.

Description

Fixed source condensable particulate matter online monitoring system and application method Technical Field The invention relates to the technical field of environmental monitoring, in particular to a fixed source condensable particulate matter on-line monitoring system and a using method thereof. Background Condensable particulates (Condensable Particulate Matter, CPM) refer to substances that exist in gaseous form within the flue or at the flue outlet, but can be converted to liquid or solid particulates in a very short time by condensation or reaction processes due to changes in conditions such as temperature, pressure, etc. after being discharged into the atmosphere. The method is an important precursor of secondary aerosol in ambient air, has obvious influence on regional environment and human health, and has important significance in accurately monitoring the regional environment and the human health. Currently, monitoring of fixed source CPM relies mainly on off-line sampling and laboratory analysis, such as controlled condensation, which typically involves the removal of filterable particulate matter from flue gas through a filter membrane, trapping CPM by a condensing system, subsequent washing and extraction of condensate and piping with various solvents, and finally evaporation, drying and weighing of the extract to obtain the CPM mass concentration. Although authoritative, the method has the inherent defects of long sampling time, complicated operation flow, large human error, incapability of obtaining real-time monitoring data and the like, and is difficult to meet the timeliness requirements of modern environment management and scientific research. In order to solve the limitation of offline monitoring, some online monitoring technologies for CPM have appeared in recent years. For example, chinese patent application publication No. CN120064046a discloses a condensable particulate matter detection system and a control method thereof. Mainly comprises a sampling gun, a condenser and a colorimetric detection unit. The method comprises the working processes of collecting flue gas by a sampling gun, condensing the flue gas by a condenser to obtain condensable particulate matter condensate, inputting the condensate into a colorimetric reaction chip box of a colorimetric detection unit, arranging a plurality of chips containing specific colorimetric reaction reagents in the colorimetric reaction chip box, carrying out specific colorimetric reaction on CPM components in the condensate and the reagents on the chips to generate color change, collecting spectral data of the chips after reaction by a probe, and determining the concentration of each component of CPM by an analysis device based on the spectral data. By combining the colorimetric reaction technology with the sampling condensing unit, a complex laboratory analysis process is avoided, and a thought is provided for realizing the rapid detection of CPM. However, in practical application, the detection accuracy of the technical solution disclosed in the above patent is still to be improved, especially in the detection of the fixed source flue gas aiming at the high-humidity and low-concentration emission characteristics of China. Specifically, after the flue gas is cooled in the condenser, a large amount of condensed water is generated, resulting in high dilution of the captured CPM condensate. For CPM samples with lower concentrations, this dilution effect makes the concentration well below the optimal detection range of the colorimetric reaction chip. The colorimetric detection is directly carried out on the sample with the low concentration, the generated spectrum signal is weak, the signal to noise ratio is low, and the sample is extremely easy to be interfered by the background, so that the accuracy and the reliability of the CPM concentration quantitative result are seriously affected. Disclosure of Invention The invention provides a fixed source condensable particulate matter on-line monitoring system and a using method thereof, which solve the problems of weak detection signal and poor accuracy of concentration quantitative results of a low-concentration sample caused by excessive dilution of a CPM sample by flue gas condensate in the prior art. The technical scheme of the invention is realized as follows: the fixed source condensable particulate matter on-line monitoring system comprises a condensation sampling unit, a condensing unit, a spectrophotometry detection unit, a reagent supply unit and a data processing and control unit, wherein the condensation sampling unit is used for extracting flue gas containing condensable particulate matters from a fixed source and condensing the flue gas to obtain condensable particulate matter condensate, the condensing unit is connected with the condensation sampling unit and used for receiving and condensing the condensable particulate matter condensate to obtain concentrated liquid to be detected,