SYNCHRONOUS SAMPLING AND MEASURING SYSTEM AND METHOD THEREOF FOR FLUE GAS PARTITION

Abstract

The present invention relates to a synchronous sampling and measuring system and a method thereof for flue gas partition. The system includes a detection device arranged at an SCR outlet for simultaneous detection of flue gas from the pipelines in different areas, wherein the detection device is connected to a speed measurement device for measuring the speed of flue gas, the speed measurement device is connected to a central control unit and one end of a valve group, respectively, the other end of the valve group is connected to an air extracting device and a dilution unit, respectively, the control end of the valve group and the control end of the air extracting device are connected to a central control unit, respectively, the dilution unit is connected to a CEMS analyzer.

Claims

1. A synchronous sampling and measuring system for flue gas partition, comprising a detection device (1) arranged at an SCR outlet for simultaneous detection of flue gas from the pipelines in different areas, wherein the detection device (1) is connected to a speed measurement device (2) for measuring the speed of flue gas, the speed measurement device (2) is connected to a central control unit (3) and one end of a valve group (4), respectively, the other end of the valve group (4) is connected to an air extracting device (5) and a dilution unit (6), respectively, the control end of the valve group (4) and the control end of the air extracting device (5) are connected to a central control unit (3), respectively, the dilution unit (6) is connected to a CEMS analyzer (7), the central control unit (3) correspondingly controls the on and off of the valve group (4) and controls the working state of the air extracting device (5) according to the data output from the speed measurement device (2), such that the flue gas sampled at the same time in the flue is transported to the air extracting device (5) according to the set time sequence.

2. The synchronous sampling and measuring system for flue gas partition of claim 1, wherein the dilution unit (6) is fed with zero gas.

3. The synchronous sampling and measuring system for flue gas partition of claim 1, wherein an outlet of the air extracting device (5) is communicated with a furnace.

4. The flue gas partitioning synchronous sampling and measuring system for flue gas partition of claim 1, wherein a calibration device (8) for calibrating and correcting the working state and precision of the speed measurement device (2), the valve group (4), the air extracting device (5) and dilution unit (6) is connected between the detection device (1) and the speed measurement device (2).

5. The synchronous sampling and measuring system for flue gas partition of claim 4, wherein the calibration device (8) is fed with standard gas.

6. The synchronous sampling and measuring system for flue gas partition of claim 4, wherein the detection device (1) comprises a plurality of probes.

7. The synchronous sampling and measuring system for flue gas partition of claim 6, wherein the speed measurement device (2) comprises a plurality of speed measurement units corresponding to different probes.

8. The synchronous sampling and measuring system for flue gas partition of claim 7, wherein the plurality of speed measurement units are respectively connected to the central control unit (3).

9. The synchronous sampling and measuring system for flue gas partition of claim 7, wherein the valve group (4) comprises a plurality of valve switches corresponding to different speed measurement units, and the calibration device (8) comprises a plurality of calibration units corresponding to different probes.

10. Asynchronous sampling and measuring method for flue gas partition using the synchronous sampling and measuring system for flue gas partition as claimed in claim 1, comprising the following steps: S1, simultaneously acquiring, by the detection device, flue gas from pipelines in different areas at the SCR outlet; S2, measuring, by the speed measurement device, the speed of the flue gas from pipelines in different areas acquired by the detection device, and outputting the speed measurement value of the flue gas from pipelines in different areas to the central control unit; S3, correspondingly controlling, by the central control unit, the on and off of the valve group and controlling the working state of the air extracting device according to the speed measurement value of the flue gas from pipelines in each area and in combination with the set control requirements, such that the flue gas sampled at the same time in different pipelines enters the air extracting device according to the set time sequence; if the valve group correspondingly conducts a certain pipeline to the passage of the air extracting device, then the air extracting device extracts the flue gas in the pipeline, so that the flue gas in the pipeline is diluted through the dilution unit, and then transported to the CEMS analyzer for flue gas analysis, to obtain the flue gas measurement results corresponding to the pipeline; and S4, outputting, by the CEMS analyzer, the flue gas measurement results corresponding to pipelines in different areas, that is, the synchronous sampling and measuring process for flue gas partition is completed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 is a structural schematic diagram of a traditional synchronous sampling and measuring system for flue gas partition at an SCR outlet;

[0032] FIG. 2 is a structural schematic diagram of the present invention;

[0033] FIG. 3 is a schematic diagram of the specific working principle of the embodiment;

[0034] Reference numerals in the figures: 1, detection device, 2, speed measurement device, 3, central control unit, 4, valve group, 5, air extracting device, 6, dilution unit, 7, CEMS analyzer, 8, calibration device.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The present invention will be described in detail below in combination with accompanying drawings and a specific embodiment.

EMBODIMENT

[0036] As shown in FIG. 2, a synchronous sampling and measuring system for flue gas partition includes a detection device 1 arranged at an SCR outlet for simultaneous detection of flue gas from the pipelines in different areas, wherein the detection device 1 is connected to a speed measurement device 2 for measuring the speed of flue gas, the speed measurement device 2 is connected to a central control unit 3 and one end of a valve group 4, respectively, the other end of the valve group 4 is connected to the air extracting device 5 and the dilution unit 6, respectively, the control end of the valve group 4 and the control end of the air extracting device 5 are connected to the central control unit 3, respectively, the dilution unit 6 is connected to a CEMS analyzer 7, the central control unit 3 correspondingly controls the on and off of the valve group 4 and controls the working state of the air extracting device 5 according to the data output from the speed measurement device 2, such that the flue gas sampled at the same time in the flue is transported to the air extracting device 5 according to the set time sequence. In the present embodiment, a calibration device 8 for calibrating and correcting the working state and precision of the speed measurement device 2, the valve group 4, the air extracting device 5 and the dilution unit 6 is connected between the detection device 1 and the speed measurement device 2.

[0037] When the above system is applied in practice, the specific measurement process includes the following steps:

[0038] S1, simultaneously acquiring, by the detection device 1, flue gas from pipelines in different areas at the SCR outlet;

[0039] S2, measuring, by the speed measurement device 2, the speed of the flue gas from pipelines in different areas acquired by the detection device 1, and outputting the speed measurement value of the flue gas from pipelines in each area to the central control unit 3;

[0040] S3, correspondingly controlling, by the central control unit 3, the on and off of the valve group 4 and controlling the working state of the air extracting device 5 according to the speed measurement value of the flue gas from pipelines in each area and in combination with the set control requirements, such that the flue gas sampled at the same time in different pipelines enters the air extracting device 5 according to the set time sequence;

[0041] if the valve group 4 correspondingly conducts a certain pipeline to the passage of the air extracting device 5, then the air extracting device 5 extracts the flue gas in the pipeline, so that the flue gas in the pipeline is diluted through the dilution unit 6, and then transported to the CEMS analyzer 7 for flue gas analysis, to obtain the flue gas measurement results corresponding to the pipeline;

[0042] S4, outputting, by the CEMS analyzer 7, the flue gas measurement results corresponding to pipelines in different areas, that is, the synchronous sampling and measuring process for flue gas partition is completed.

[0043] In the present embodiment, as shown in FIG. 3, the detection device 1 includes a plurality of probes to acquire the flue gas from pipelines in different areas simultaneously, and the speed measurement device 2 includes a plurality of speed measurement units corresponding to different probes to measure the speed of the flue gas from pipelines in different areas respectively, and a plurality of speed measurement units are connected to the central control unit 3 respectively, since the length of the probes and the flue gas sampling pipeline are known fixed values, so the time of flue gas from each pipeline reaching the CEMS analyzer 7 can be obtained through analysis and calculation, the central control unit 3 functions to collect the signals of the speed measurement units and control the valve group 4 and the air extracting device 5 according to the program set internally or set by the user, so that the flue gas sampled at the same time in the flue enters the air extracting device 5 according to the set time sequence;

[0044] the valve group 4 includes a plurality of valve switches corresponding to different speed measurement units, i.e., constituting a plurality of valve branches whose function is to conduct or close the passage from each sampling pipeline to the air extracting device 5, so that flue gas sampled at the same time in the flue can enter the air extracting device 5 according to the set time sequence for dilution by the dilution unit 6 and then for analysis by the CEMS analyzer 7;

[0045] the air extracting device 5 extracts the flue gas, so that the flue gas from each sampling duct can enter the CEMS analyzer 7, and the outlet of the air extracting device 5 is communicated with a furnace to discharge the extracted sample gas to the furnace;

[0046] the dilution unit 6 functions to dilute the concentration of the diluted sample gas to match the range of the CEMS analyzer 7, and the dilution unit 6 is fed with zero gas;

[0047] the CEMS analyzer 7 functions to analyze the diluted sample gas;

[0048] in addition, a plurality of calibration units are correspondingly connected between the probe and the speed measurement unit, each calibration unit is introduced with standard gas, and functions to calibrate and correct the working state and precision of the speed measurement unit, the valve group, the air extracting device and the dilution unit.

[0049] In summary, in the technical solution provided in the present invention, all the probes adopt a total dilution unit, to reduce measurement errors, since one dilution unit corresponds to a CEMS gas analyzer, the measurement errors of the dilution unit can be corrected and compensated through the introduction of zero gas, so as to correct the measurement precision.

[0050] In the present technical solution, real-time difference during measurement can be reduced through signal measurement of the speed measurement unit. When the flue gas sampling length of each pipe branch is determined unchanged, the pressure of the diluted flue gas is low and is easily affected by the bending degree of the pipeline and attachments of the pipeline, thereby easily leading to a great difference between the time at which the analyzed flue gas reaches the CEMS analyzer and the preset time, however, the time difference can be calculated in real time after the speed measurement unit measures the speed, and then the central control unit is used to control the valve group, then the real-time difference during measurement can be effectively eliminated.