Multifunctional flue gas flow field rapid measurement and early warning system

Abstract

The present invention relates to the technical field of flue gas measurement equipment, and specifically to a multifunctional flue gas flow field rapid measurement and early warning system, comprising a control module and a gas collection module, wherein the control module comprises a control host and a display electrically connected to the control host, the control host is signal-connected to the gas collection module, the gas collection module comprises a collection device and a detection device, sampling is carried out in a flue gas pipeline by a sampler and then transported to a gas measurement chamber, and then data is collected by a detection component and then transported to the control host, the control host summarizes the collected data and displays it on a display screen, and at the same time stores and backs up the data, thereby simplifying the operation process and shortening the measurement cycle.

Description

Technical Field

[0001] The invention relates to the technical field of flue gas measurement equipment, and in particular to a multifunctional flue gas flow field rapid measurement and early warning system. Background Art

[0002] For thermal power units and deep peak-shaving units that have undergone thermal power flexibility transformation, uneven flue gas flow field and abnormal fluctuations in the denitrification system under different operating conditions are one of the main reasons for low denitrification efficiency. For denitrification systems using SCR denitrification technology, adjusting ammonia injection according to the changes in the real-time online values ​​of key parameters of the flue gas flow field under different operating conditions is one of the effective ways to improve the utilization efficiency of the reducing agent and the denitrification efficiency of the system.

[0003] The key indicators of the flue gas flow field of the denitrification system mainly include the flue gas velocity field, temperature field, fly ash concentration field, NOx and oxygen concentration field, etc. The evaluation and adjustment of the flue gas flow field of the denitrification system and the regulation of the ammonia injection system are closely related to the real-time distribution of the above parameters.

[0004] At present, in general, the test of flue gas flow field is still mainly carried out by grid sampling and measuring the flue gas separately with portable equipment. For example, the Chinese patent (CN112033637A) discloses a SCR denitrification flue gas flow field distribution measurement device and evaluation method, which belongs to the field of boiler SCR denitrification flow field control. The present invention includes a flue gas flow velocity measurement device, a flow velocity analysis device, a flow velocity display device and a denitrification catalyst. The flue gas flow velocity measurement device includes a flow velocity measurement point, a measurement point connecting pipe and a measurement point mounting bracket. The flow velocity analysis device includes a flow velocity analysis box, a flue gas pressure tester and a flow velocity test distributor. The flow velocity display device includes a flow velocity display and evaluation interface. The flow velocity measurement point is connected to the flow velocity test distributor through the measurement point connecting pipe. The measurement point mounting bracket supports the flow velocity measurement point. The flow velocity measurement point is fixed to the top of the denitrification catalyst. The flow velocity analysis box controls the flow velocity test distributor, and the flow velocity analysis box is fed back to the flow velocity analysis box through the flue gas pressure tester, and then transmitted to the flow velocity display and evaluation interface. Since grid sampling requires point-by-point sampling according to the size of the flue, the operation process is complicated and cumbersome; in addition, there are many parameters to be measured, such as fly ash concentration field and velocity field, which require multiple separate sampling tests, resulting in the above measurement cycle taking at least 1-2 hours to complete, and the real-time performance of the test data obtained is very poor. Especially for peak-shaving units, due to frequent adjustments in unit load, the actual working conditions of the flue gas flow field of the denitrification system will also change accordingly, and the effectiveness of the test data of each parameter is extremely poor, which has no reference significance for the adjustment of the flue gas flow field and the ammonia injection system. Summary of the invention

[0005] In order to solve the above problems, an embodiment of the present invention provides a multifunctional flue gas flow field rapid measurement and early warning system, which can quickly measure various data at different points, and perform data aggregation through the control host. After the results are obtained, the results are displayed on a display. While saving data collection steps, the results can be displayed faster and more concisely, which is convenient for operators to compare data.

[0006] In order to achieve the above-mentioned purpose, the embodiment of the present invention specifically adopts the following technical scheme: a multifunctional flue gas flow field rapid measurement and early warning system, including a control module and a gas collection module, the control module includes a control host and a display electrically connected to the control host, the control host is signal-connected to the gas collection module, the gas collection module includes a collection device and a detection device, the collection device includes a sampler, one end of the sampler extends into the flue gas duct, and the other end is provided with a connection with the detection device through a conveying duct, the collection device includes a gas measurement chamber, and a detection component is arranged in the gas measurement chamber.

[0007] As a further improvement of the above technical solution:

[0008] There are multiple samplers corresponding to different sampling positions in the flue gas duct, and each sampler is connected to the gas measurement chamber through a delivery pipeline.

[0009] Each of the conveying pipelines is provided with a filtering device, which includes a dust collector and a precision filter, and the precision filter is located between the gas measurement chamber and the dust collector.

[0010] The detection assembly comprises a NOx sensor, an oxygen sensor, a temperature sensor, a pressure sensor and a laser ammonia escape measurement device which are sequentially mounted on a gas measurement chamber.

[0011] An air inlet pipe connected to the sampler is arranged at the upper part of the gas measurement chamber, a purge air pipe is arranged at one side of the air inlet pipe, and an air outlet pipe is arranged at the bottom of the gas measurement chamber.

[0012] A negative pressure generator is arranged below the gas measurement chamber.

[0013] The diameter of the gas measurement chamber gradually decreases from the middle to both ends.

[0014] The display is a color display screen. When displaying data, data that exceeds the set value range is distinguished by different colors to prompt operators of abnormal information and facilitate data comparison.

[0015] The beneficial effects of the embodiment of the present invention are as follows: the multifunctional flue gas flow field rapid measurement and early warning system comprises a control module and a gas collection module, the control module comprises a control host and a display electrically connected to the control host, the control host is signal-connected to the gas collection module, the gas collection module comprises a collection device and a detection device, sampling is carried out in the flue gas duct by a sampler and then transported to a gas measurement chamber, and then data is collected by a detection component and then transported to the control host, the control host calculates the collected data and displays it on the display screen, and at the same time stores and backs up the data, which simplifies the operation process and shortens the measurement cycle;

[0016] It can realize the synchronous and independent measurement of smoke velocity field, temperature field and concentration field at multiple sampling points, thus improving the accuracy and real-time performance of the detection data;

[0017] The data analysis and early warning system can timely discover problems in the flue gas flow field and issue early warnings, providing strong data support for the adjustment of the flue gas flow field and the ammonia injection control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 It is a structural schematic diagram of the acquisition module in the present invention;

[0020] Figure 3 It is a schematic diagram of the structure of the gas detection chamber in the present invention.

[0021] In the figure: 1. Control host; 2. Display; 3. Sampler; 4. Flue gas duct; 5. Delivery duct; 6. Gas measurement chamber; 7. Dust collector; 8. Precision filter; 9. NOx sensor; 10. Oxygen sensor; 11. Temperature sensor; 12. Inlet pipe; 13. Purge pipe; 14. Outlet pipe; 15. Pressure sensor; 16. Laser ammonia escape measurement device; 17. Negative pressure generator. DETAILED DESCRIPTION

[0022] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0023] See also Figure 1-3The multifunctional flue gas flow field rapid measurement and early warning system of this embodiment includes a control module and a gas collection module. The control module includes a control host 1 and a display 2 electrically connected to the control host 1. The control host 1 is signal-connected to the gas collection module. The gas collection module includes a collection device and a detection device. The collection device includes a sampler 3. One end of the sampler 3 extends into the flue gas duct 4, and the other end is provided with a connection with the detection device through a delivery pipe 5. The collection device includes a gas measurement chamber 6. A detection component is arranged in the gas measurement chamber 6. The sampler 3 takes samples in the flue gas duct 4 and then transports the samples to the gas measurement chamber 6. Then, the samples are collected by the detection component and then transported to the control host. The control host calculates the collected data and displays them on the display screen, and stores and backs up the data at the same time.

[0024] There are multiple samplers 3, corresponding to different sampling positions in the flue gas duct 4. Each sampler 3 is connected to the gas measurement chamber 6 through a delivery pipe 5. Each sampler 3 includes an extractable flue gas sampling tube and two flow rate measuring tubes. Multiple samplers 3 are connected to the flue gas duct 4 after being integrated and installed through a flange. Corresponding to different positions of the flue gas duct, the air outlet end of each sampler 3 is connected to a differential pressure transmitter. The differential pressure transmitter can timely measure the flue gas pressure difference at the measuring points of each sampling tube group, and then obtain the flue gas flow rate at the measuring point by conversion.

[0025] A filtering device is provided on each conveying pipeline 5, and the filtering device includes a dust collector 7 and a precision filter 8. The dust collector 7 adopts a cyclone dust collector. The cyclone dust collector is provided with an air inlet pipe and an air outlet pipe connected to the conveying pipeline 4, and a dust collecting cylinder is installed at the bottom. The smoke content during the measurement period can be obtained by weighing the collected smoke. The precision filter 8 is located between the gas measurement chamber 6 and the dust collector 7. Through the double filtration of the dust collector 7 and the precision filter 8, the dust and impurities in the gas that may affect the measurement results can be effectively removed, thereby ensuring the accuracy of the measurement results.

[0026] The detection component includes a NOx sensor 9, an oxygen sensor 10, a temperature sensor 11, a pressure sensor 15 and a laser ammonia escape measuring device 16 which are sequentially installed on the gas measurement chamber 6. The laser ammonia escape measuring device 16 includes a transmitter and a receiver which are installed on the upper part of the gas measurement chamber 6. Multiple measuring devices can be selected and installed according to actual measurement requirements. Each measuring device transmits data with the control host 1 through a wireless transmission module.

[0027] An air inlet pipe 12 connected to the sampler 3 is provided at the upper part of the gas measurement chamber 6, a purge air pipe 13 is provided on one side of the air inlet pipe 12, and an air outlet pipe 14 is provided at the bottom of the gas measurement chamber 6. The design of the purge air pipe 13 can timely clear the residual gas in the gas measurement chamber 6 when collecting multiple groups of data, thereby preventing different groups of flue gases from cross-interfering with the detection results, and also improving the timeliness of the measurement response.

[0028] A negative pressure generator 17 is provided below the gas measurement chamber 6 .

[0029] The diameter of the gas measurement chamber 6 gradually decreases from the middle to the two ends. The structure of the gas measurement chamber is wide in the middle and closed at the top and bottom. On the one hand, it is convenient to install the required gas measurement sensor. On the other hand, it is convenient for the extracted flue gas to be quickly dispersed in the measurement chamber, thereby realizing rapid purge of the measurement chamber.

[0030] Display 2 is a color display screen. When displaying data, different colors are used to distinguish data that exceeds the set value range, so as to prompt the operator of abnormal information and facilitate data comparison.

[0031] Method of use: In this embodiment, three groups of samplers 3 are used to collect data at different positions of the flue gas duct 4. The main collected data are NOx, O2, temperature and flow rate. The three samplers are respectively recorded as sampler 1, sampler 2 and sampler 3, which correspond to different depths in the flue gas duct 4. When in use, first, sampler 1 is used to collect data. The collected gas sample passes through the dust collector 7 and the precision filter 8 when passing through the conveying pipeline 5, and then enters the gas measurement chamber 6. During the conveying process, the differential pressure transmitter can measure the flow rate. Finally, the data collected by the detection component in the gas measurement chamber 6 is transported to the control host 1 for data aggregation and calculation. After the measurement of the first group of gas samples is completed, the gas in the gas measurement chamber 6 is discharged by blowing the gas pipe before the next group of gases are entered and detected to avoid crossover between the two groups of gas samples, resulting in inaccurate data measurement. The entry and purge of different groups of gases are controlled by solenoid valves. Therefore, multiple solenoid valves are installed in the collection to execute different commands, and the operation commands are sent through the control host 1.

[0032] The calculation method for the control host is as follows:

[0033] 1) Detection data balance analysis:

[0034] A balance analysis is performed on the data of the same parameter at different points. According to the uniformity requirements of the flue gas flow field, when the flue gas flow field is relatively uniform, the CV value of the detection data of the same parameter at different points should be less than 15% (this value can be set according to the specific situation). When the CV value of the detection data exceeds the set value, the detection data out of tolerance area will be displayed in red as a warning.

[0035] Table 1: NOx (mg / Nm3) test data and relative deviation values

[0036]

[0037]

[0038] Table 2: O2 test data and relative deviation values

[0039]

[0040] Table 3: Temperature test data and relative deviation values

[0041]

[0042] Table 4: Flow rate test data and relative deviation values

[0043]

[0044] 2) Detection data correlation analysis

[0045] The correlation analysis is mainly carried out on the data of related parameters in the same area. According to the relevant SCR denitrification process, there is a strong anti-correlation between NOx and ammonia slip. If the absolute value of the correlation is less than 0.8 (settable), it can be concluded from this analysis that there are potential hazards in the detection area and the system will issue an early warning alarm.

[0046]

[0047] Data analysis

[0048] Balance analysis of NOx detection data at each measuring point

[0049] NOx concentration average value, distribution standard deviation and relative standard deviation, etc.

[0050]

[0051] Where:

[0052] C NO，actO2 : Measured value of NO concentration at each point on the cross section μL / L

[0053] :NO at each point of the cross sectionx Concentration conversion value (6% O2) mg / m3

[0054] :Section NO x Average concentration (6% O2) mg / m3

[0055] δ: NO1 concentration distribution standard deviation mg / m3

[0056] CV: Relative standard deviation %

[0057] Note: The technical methods for other parameters such as mean value, distribution standard deviation and relative standard deviation are similar.

[0058] Correlation analysis of each group of data

[0059] The correlation coefficient calculation formula is:

[0060]

[0061] Where:

[0062] X, Y: two sets of data to be analyzed

[0063] x, y: elements of two sets of data to be analyzed

[0064] : The average value of the two groups of data to be analyzed

[0065] When the correlation coefficient is close to +1 or -1, it means that there is a positive correlation (+1) or negative correlation (-1) between the two sets of test data; when it is close to 0, it means there is no correlation or a weak correlation.

[0066] It should be noted that in the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0067] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0068] The term "comprise" or any other similar term is intended to cover a non-exclusive inclusion, such that a process, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, article, or apparatus / device.

[0069] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A multifunctional flue gas flow field rapid measurement and early warning system, comprising a control module and a gas collection module, characterized in that: The control module comprises a control host (1) and a display (2) electrically connected to the control host (1), and the control host (1) is signal-connected to the gas collection module; The gas collection module comprises a collection device and a detection device. The collection device comprises a sampler (3). One end of the sampler (3) extends into a flue gas duct (4), and the other end is provided with a connection with the detection device via a delivery duct (5). The collection device comprises a gas measurement chamber (6), and a detection component is provided in the gas measurement chamber (6).

2. The multifunctional flue gas flow field rapid measurement and early warning system according to claim 1 is characterized in that: There are multiple samplers (3) corresponding to different sampling positions in the flue gas duct (4), and each sampler (3) is connected to a gas measurement chamber (6) via a delivery duct (5).

3. The multifunctional flue gas flow field rapid measurement and early warning system according to claim 2 is characterized in that: Each of the conveying pipelines (5) is provided with a filtering device, the filtering device comprising a dust collector (7) and a precision filter (8), and the precision filter (8) is located between the gas measurement chamber (6) and the dust collector (7).

4. The multifunctional flue gas flow field rapid measurement and early warning system according to claim 2 is characterized in that: The detection assembly comprises a NOx sensor (9), an oxygen sensor (10), a temperature sensor (11), a pressure sensor (15) and a laser ammonia escape measurement device (16) which are sequentially mounted on a gas measurement chamber (6).

5. The multifunctional flue gas flow field rapid measurement and early warning system according to claim 4 is characterized in that: An air inlet pipe (12) connected to the sampler (3) is arranged at the upper part of the gas measurement chamber (6), a purge air pipe (13) is arranged on one side of the air inlet pipe (12), and an air outlet pipe (14) is arranged at the bottom of the gas measurement chamber (6).

6. The multifunctional flue gas flow field rapid measurement and early warning system according to claim 5 is characterized in that: A negative pressure generator (17) is arranged below the gas measurement chamber (6).

7. The multifunctional flue gas flow field rapid measurement and early warning system according to claim 5 is characterized in that: The diameter of the gas measurement chamber (6) gradually decreases from the middle to both ends.

8. The multifunctional flue gas flow field rapid measurement and early warning system according to claim 1 is characterized in that: The display (2) is a color display screen. When displaying data, data that exceeds the set value range is distinguished by different colors, so as to prompt the operator that the information is abnormal and facilitate data comparison.

Images