A system and method for determining the carbon dioxide content of flue gas from a stationary pollution source

Abstract

The present application relates to the technical field of flue gas content measurement, in particular to a system and method for measuring carbon dioxide content in flue gas of fixed pollution source, which comprises an absorption cell and an absorption container; an atomizer is arranged at the inner top of the absorption cell, one input end of the atomizer is connected with an absorption liquid pool through an absorption liquid delivery device, and the other input end is connected with the inner bottom of the absorption cell through a circulation device; a sample gas delivery device is connected with one side of the absorption cell; a transfer device is connected between the other side of the absorption cell and the absorption container; a sealed tube is arranged through the absorption container; the two ends of the sealed tube connected with the absorption container are transparent windows; a spectrophotometer is arranged at the transparent windows; an electrolyte solution and an indicator are arranged in the sealed tube; and a temperature measuring element is arranged in the absorption container; wherein the material of the sealed tube is a carbon dioxide selective permeation membrane. The system can be used to continuously and accurately measure the carbon dioxide content in the flue gas of fixed pollution source.

Description

Technical Field

[0001] The present invention relates to the technical field of measuring gas content in flue gas, and in particular to a system and method for measuring carbon dioxide content in flue gas from a fixed pollution source. Background Art

[0002] In order to protect the climate and slow down global warming, it is necessary to continuously measure the CO2 content in the flue gas of stationary pollution sources. There are many methods for measuring the CO2 content in the flue gas of pollution sources, including non-dispersive infrared method, spectrophotometry, volumetric titration, Fourier transform infrared spectroscopy, tunable semiconductor laser absorption spectroscopy and gas chromatography. However, based on the above methods, there is currently no online monitoring equipment for carbon dioxide content. At the same time, the existing spectrophotometric method for measuring the CO2 content in the flue gas of stationary pollution sources requires manual preparation of absorption liquid, manual sample collection, proper sample storage and circulation, and finally laboratory analysis to achieve accurate measurement. However, in actual operation, the test results are not timely, and it is impossible to achieve continuous and accurate measurement of the CO2 content in the flue gas of stationary pollution sources. It also has certain restrictions on the analysis and measurement of large quantities of samples, which increases the uncertainty of CO2 control from stationary pollution sources.

[0003] Patent publication number CN213516856U discloses a real-time atmospheric monitoring device for forestry ecological environment, and patent publication number CN213181259U discloses an in-situ detection device for marine carbon dioxide partial pressure. Both include a spectrophotometer and a sampling unit, but they do not involve the selective permeation of flue gas and carbon dioxide from fixed pollution sources, and the timeliness of sampling and analysis is poor.

[0004] Therefore, there is an urgent need for a system and method for measuring the carbon dioxide content in flue gas from fixed pollution sources. Summary of the Invention

[0005] The present invention aims to solve the problems in the prior art of lack of online monitoring equipment for measuring the carbon dioxide content in flue gas from fixed pollution sources, and the poor timeliness of using traditional methods to measure the carbon dioxide content in flue gas from fixed pollution sources. A system and method for measuring the carbon dioxide content in flue gas from fixed pollution sources are provided.

[0006] In order to achieve the above-mentioned object, the present invention provides a system for measuring the carbon dioxide content in flue gas from a stationary pollution source in a first aspect. The system comprises an absorption cell and an absorption container;

[0007] An atomizer is provided at the inner top of the absorption cell, one input end of the atomizer is connected to the absorption liquid cell via an absorption liquid delivery device, and the other input end is connected to the inner bottom of the absorption cell via a circulation device, one side of the absorption cell is connected to a sample gas delivery device, a transfer device is connected between one side of the absorption cell and the absorption container, a sealing tube is provided through the absorption container, both ends of the sealing tube connected to the absorption container are transparent windows, a spectrophotometer is provided at the transparent window, an electrolyte solution and an indicator are contained in the sealing tube, and a temperature measuring element is provided inside the absorption container;

[0008] Wherein, the sealing tube is made of a carbon dioxide selective permeable membrane.

[0009] Preferably, the carbon dioxide selective permeable membrane is a semi-permeable membrane containing polytetrafluoroethylene or polyethylene.

[0010] Preferably, the absorption liquid delivery equipment includes a delivery pipe and a delivery pump;

[0011] The input end and the output end of the delivery pump are respectively connected to the output end of the absorption liquid pool and an input end of the atomizer through a delivery pipe.

[0012] Preferably, the circulation device includes a circulation pipe and a circulation pump;

[0013] The input end and the output end of the circulation pump are respectively connected to the inner bottom of the absorption tank and the other input end of the atomizer through a circulation pipe.

[0014] Preferably, the transfer device includes a transfer pipe and a transfer pump;

[0015] The input end and the output end of the transfer pump are respectively connected to the side of the absorption tank close to the bottom and the absorption container through a transfer pipe.

[0016] Preferably, the sample gas delivery equipment includes a sample gas delivery pipe, a sample gas delivery pump and a sampling device;

[0017] The input end and the output end of the sample gas delivery pump are respectively connected to the output end of the sampling device and one side of the absorption cell through a sample gas delivery pipe.

[0018] Preferably, the sampling device comprises a sampling device, a dust filtering device and a condensing device connected in sequence;

[0019] One end of the condensation device is connected to the input end of the sample gas delivery pump through the sample gas delivery pipe.

[0020] Preferably, a timing device is further included to control the absorption liquid delivery device, the circulation device and the sample gas delivery device to be turned on or off at a set time.

[0021] To achieve the above-mentioned object, the present invention provides, in a second aspect, a method for measuring the carbon dioxide content in flue gas from a stationary pollution source. The method is implemented using the system for measuring the carbon dioxide content in flue gas from a stationary pollution source, and the method comprises the following steps:

[0022] S1. Using the sample gas delivery device to obtain a sample gas containing carbon dioxide, and delivering the obtained sample gas containing carbon dioxide to the absorption cell to replace the original gas in the absorption cell. When the gas in the absorption cell is completely replaced, closing the sample gas delivery device;

[0023] S2, using the absorption liquid conveying device to convey a certain amount of absorption liquid in the absorption liquid pool to the atomizer for spraying, and closing the absorption liquid conveying device after the conveying is completed;

[0024] S3, using the circulation device to circulate the liquid in the absorption tank to the atomizer for spraying to obtain the liquid to be tested, and closing the circulation device after the cyclic spraying is completed;

[0025] S4, using the transfer device to transfer the liquid to be tested in the absorption cell to the absorption container, and closing the transfer device after the transfer is completed, wherein ions in the liquid to be tested penetrate into the sealed tube and mix with the electrolyte solution therein, and the pH value of the mixed electrolyte solution changes, and a color is developed under the action of the indicator;

[0026] S5. Using the spectrophotometer, measure the absorbance of the mixed electrolyte solution in the sealed tube, and calculate the concentration of carbon dioxide based on the absorbance and temperature.

[0027] Preferably, the absorption liquid and the electrolyte solution are both potassium bicarbonate solution or sodium bicarbonate solution, and the indicator is phenol red;

[0028] The wavelength at which the spectrophotometer measures the absorbance of the mixed electrolyte solution in the sealed tube is 555 nm.

[0029] According to the above technical solution, based on the system, the sample gas conveying device obtains carbon dioxide and conveys the obtained sample gas containing carbon dioxide into the absorption cell to replace the original gas in the absorption cell. The absorption liquid conveying device conveys a certain amount of absorption liquid in the absorption liquid cell to the atomizer for spraying. The circulation device circulates the liquid in the absorption cell to the atomizer for spraying to obtain the liquid to be tested. The liquid to be tested in the absorption cell is then transferred to the absorption container by the transfer device. The ions in the liquid to be tested penetrate into the sealed tube and mix with the electrolyte solution therein. The pH value of the mixed electrolyte solution changes and develops color under the action of the indicator. Finally, the absorbance of the mixed electrolyte solution in the sealed tube is measured by the spectrophotometer, and the concentration of carbon dioxide is calculated based on the absorbance and temperature. This achieves continuous and accurate measurement of the carbon dioxide content in the flue gas of a fixed pollution source as needed, with the advantages of simple operation and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of a system for determining the carbon dioxide content in the flue gas of a stationary pollution source;

[0031] Figure 2 It is a flow chart of the method for determining the carbon dioxide content in the flue gas of a stationary pollution source.

[0032] Description of Reference Numerals

[0033] Absorption cell 1; atomizer 2; sample gas delivery pipe 3; sample gas delivery pump 4; sampling device 5;

[0034] Delivery pipe 6; delivery pump 7; absorption liquid tank 8; circulation pipe 9; circulation pump 10; transfer pipe 11;

[0035] Transfer pump 12; absorption container 13; sealing tube 14; transparent window 15; light source 16;

[0036] Monochromator 17; light detector 18; temperature measuring element 19. DETAILED DESCRIPTION

[0037] The following describes the specific implementation of the embodiment of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiment of the present invention and is not used to limit the embodiment of the present invention.

[0038] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate relative importance or implicitly specify the quantity of the technical features indicated. Therefore, unless otherwise specified, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features; "plurality" means two or more. The term "comprising" and any variations thereof are intended to imply the non-exclusive inclusion, possible presence, or addition of one or more other features, units, components, and / or combinations thereof.

[0039] Furthermore, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly, and may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0040] The first aspect of the present invention provides a system for measuring the carbon dioxide content in the flue gas of a stationary pollution source, such as Figure 1 As shown, the system for measuring the carbon dioxide content in the flue gas of a stationary pollution source includes an absorption pool 1 and an absorption container 13;

[0041] The top of the absorption cell 1 is provided with an atomizer 2. One input end of the atomizer 2 is connected to the absorption liquid tank 8 via an absorption liquid delivery device, and the other input end is connected to the inner bottom of the absorption cell 1 via a circulation device. A sample gas delivery device is connected to one side of the absorption cell 1. A transfer device is connected between one side of the absorption cell 1 and the absorption container 13. A sealed tube 14 is provided through the absorption container 13. The two ends of the sealed tube 14 connected to the absorption container 13 are transparent windows 15. A spectrophotometer is provided at the transparent window 15. The sealed tube 14 is filled with an electrolyte solution and an indicator. A temperature measuring element 19 is provided inside the absorption container 13. The material of the sealed tube 14 is a carbon dioxide selective permeable membrane. The reason for providing the temperature measuring element 19 inside the absorption container 13 is that most color development reactions require a certain amount of time to complete. The length of time is related to the temperature, and the absorbance time curve at different temperatures is inconsistent. Preferably, the system also includes a display for displaying the temperature value measured by the temperature measuring element 19.

[0042] According to the technical scheme, the system obtains carbon dioxide based on the sample gas conveying device, and conveys the obtained sample gas containing carbon dioxide to the absorption cell to replace the original gas in the absorption cell, conveys a certain amount of absorption liquid in the absorption liquid cell to the atomizer to spray by the absorption liquid conveying device, and conveys the liquid in the absorption cell to the atomizer to spray by the circulating device to obtain the liquid to be measured, and then conveys the liquid to be measured in the absorption cell to the absorption container by the transferring device, wherein the ions in the liquid to be measured penetrate into the sealed tube and mix with the electrolyte solution in the sealed tube, the pH value of the mixed electrolyte solution changes, the mixed electrolyte solution develops color under the action of the indicator, the absorbance of the mixed electrolyte solution in the sealed tube is measured by the spectrophotometer, and the concentration of carbon dioxide is calculated based on the absorbance and the temperature. The continuous and accurate determination of the carbon dioxide content in the flue gas of the stationary pollution source is realized according to the needs, and the system has the advantages of simple operation and low cost.

[0043] In the system for determining the carbon dioxide content in the flue gas of the stationary pollution source, the system further comprises a timing device for controlling the absorption liquid conveying device, the circulating device and the sample gas conveying device to be opened or closed at a set time, so that the amount of the sample gas containing carbon dioxide and the amount of the absorption liquid are accurately controlled, and the time of the circulating spray is controlled, so that the absorption liquid sufficiently absorbs the carbon dioxide to obtain the liquid to be measured, and the carbon dioxide content in the flue gas of the stationary pollution source is accurately determined.

[0044] In the system for determining the carbon dioxide content in the flue gas of the stationary pollution source, the sample gas conveying device comprises a sample gas conveying pipe 3, a sample gas conveying pump 4 and a sampling device 5, the input end and the output end of the sample gas conveying pump 4 are connected with the output end of the sampling device 5 and one side of the absorption cell 1 through the sample gas conveying pipe 3. In actual application, the sample gas containing carbon dioxide in the sampling device 5 is conveyed to the absorption cell 1 through the sample gas conveying pipe 3 under the action of the sample gas conveying pump 4. In a specific embodiment, the sampling device 5 comprises a sampling device, a dust filtering device and a condensing device connected in sequence, one end of the condensing device is connected with the input end of the sample gas conveying pump 4 through the sample gas conveying pipe 3. In actual application, preferably, in order to ensure the accurate measurement of the carbon dioxide content in the flue gas, the sample gas containing carbon dioxide is first sampled by the sampling device, then is sent into the dust filtering device for filtering to prevent the dust mixed in the sample gas containing carbon dioxide from affecting the measurement result, and then the filtered sample gas containing carbon dioxide is condensed to make the carbon dioxide gas better absorbed by the absorption liquid.

[0045] In the system for measuring the carbon dioxide content in flue gas from a stationary pollution source described in the present invention, the absorption liquid delivery device includes a delivery pipe 6 and a delivery pump 7; the input and output ends of the delivery pump 7 are connected to the output end of the absorption liquid reservoir 8 and one input end of the atomizer 2, respectively, through the delivery pipe 6. In actual use, the delivery pump 7 is used to deliver the absorption liquid in the absorption liquid reservoir 8 to one input end of the atomizer 2 through the delivery pipe 6. The amount of absorption liquid introduced into the absorption reservoir 1 through the atomizer 2 is controlled to ensure effective absorption of carbon dioxide while avoiding waste of the absorption liquid. In a specific embodiment, the circulation device includes a circulation pipe 9 and a circulation pump 10; the input and output ends of the circulation pump 10 are connected to the inner bottom of the absorption reservoir 1 and the other input end of the atomizer 2, respectively, through the circulation pipe 9, for circulating the liquid in the inner bottom of the absorption reservoir 1 through the atomizer 2 for spraying. This further cooperates with the absorption liquid delivery device to ensure effective absorption of carbon dioxide gas by the absorption liquid while further avoiding waste of the absorption liquid.

[0046] In the system for measuring carbon dioxide content in flue gas from a stationary pollution source described herein, the transfer equipment includes a transfer pipe 11 and a transfer pump 12. The input and output ends of the transfer pump 12 are connected to the bottom side of the absorption cell 1 and the absorption container 13, respectively, via the transfer pipe 11. In actual use, the transfer pump 12 is activated to transfer the liquid to be measured from the absorption cell 1 to the absorption container 13 via the transfer pipe 11.

[0047] In the system for measuring the carbon dioxide content in the flue gas of a fixed pollution source described in the present invention, the carbon dioxide selective permeable membrane is a semi-permeable membrane containing polytetrafluoroethylene or polyethylene, so that the ions in the liquid to be measured penetrate into the sealed tube 14 through the semi-permeable membrane containing polytetrafluoroethylene or polyethylene and mix with the electrolyte solution in the sealed tube 14. The pH value of the electrolyte solution stabilized after mixing changes, so that the mixed and stabilized electrolyte solution develops color under the action of the indicator. After the color development, the absorbance of the mixed electrolyte solution in the sealed tube 14 is measured by the spectrophotometer, and the concentration of carbon dioxide is calculated based on the absorbance and temperature. Wherein, if Figure 1As shown, the spectrophotometer comprises a light source 16, a monochromator 17 and a light detector 18, the light source 16 and the monochromator 17 are sequentially arranged at the transparent window 15 at one end of the sealed tube 14, and the light detector 18 is arranged at the transparent window 15 at the other end of the sealed tube 14. Specifically, in actual application, the light source 16 emits light of a certain intensity, which is processed into monochromatic light (i.e. 555 nm wavelength light) under the action of the monochromator 17, and then the monochromatic light passes through the sealed tube 14 and is transmitted to the light detector 18 at the transparent window 15 at the other end of the sealed tube 14, the light detector 18 acquires the intensity of the transmitted light, and the ratio of the intensity of the transmitted light acquired by the light detector 18 to the intensity of the light emitted by the light source 16 is the absorbance. The carbon dioxide selective permeation membrane can effectively pass through the ions in the to-be-measured liquid in both directions, thereby ensuring that the ion concentration in the to-be-measured liquid in the sealed tube 14 is consistent with that in the absorption container 13. The mechanism for calculating the concentration of carbon dioxide based on absorbance and temperature is as follows: at a certain temperature, the incident light is parallel monochromatic light and vertical irradiation, the light-absorbing substance is a uniform non-scattering system, there is no interaction between light-absorbing particles, the interaction between radiation and the substance is limited to the process of light absorption, and no fluorescence and photochemical phenomena occur. The absorbance and the concentration of carbon dioxide follow the Lambert-Beer law, i.e. there is a quantitative relationship between the light absorption of the substance. According to the Lambert-Beer law, the absorbance A is proportional to the concentration c of the light-absorbing substance under the condition that the thickness of the medium is determined, and a standard curve of the concentration of carbon dioxide can be established, and the specific calculation formula is as follows:

[0048]

[0049] Wherein, A is the absorbance, I0 is the incident light intensity, I t is the intensity of the projected light, T is the projection ratio, or the transmittance, K is the coefficient, l is the thickness of the absorption medium, and c is the concentration of the light-absorbing substance.

[0050] According to the standard working curve established according to different concentrations of carbon dioxide standard samples, the concentration of carbon dioxide in the fixed pollution source can be obtained.

[0051] The second aspect of the present application provides a method for determining the content of carbon dioxide in flue gas of a fixed pollution source, as shown in the description, the method is implemented by using the system for determining the content of carbon dioxide in flue gas of a fixed pollution source, and the method comprises the following steps: Figure 2

[0052] S1, the sample gas containing carbon dioxide is obtained by using the sample gas conveying device, and the obtained sample gas containing carbon dioxide is conveyed to the absorption cell 1 to replace the original gas in the absorption cell 1, and when the replacement of the gas in the absorption cell 1 is completed, the sample gas conveying device is closed;

[0053] ​S2, using the absorption liquid conveying device to convey a certain amount of absorption liquid in the absorption liquid pool 8 to the atomizer 2 for spraying, and closing the absorption liquid conveying device after the conveying is completed;

[0054] S3, using the circulation device to circulate the liquid in the absorption tank 1 to the atomizer 2 for spraying to obtain the liquid to be tested, and closing the circulation device after the cyclic spraying is completed;

[0055] S4. Using the transfer device, the liquid to be tested in the absorption cell 1 is transferred to the absorption container 13. After the transfer is completed, the transfer device is closed. Ions in the liquid to be tested penetrate into the sealed tube 14 and mix with the electrolyte solution therein. The pH value of the mixed electrolyte solution changes, and color is developed under the action of the indicator.

[0056] S5. Using the spectrophotometer, measure the absorbance of the mixed electrolyte solution in the sealed tube 14, and calculate the concentration of carbon dioxide based on the absorbance and temperature.

[0057] In the method for measuring carbon dioxide content in flue gas from a stationary pollution source described herein, the absorption liquid and the electrolyte solution are both potassium bicarbonate solution or sodium bicarbonate solution, and the indicator is phenol red. Specifically, when the pH value of the mixed electrolyte solution changes, phenol red causes the mixed electrolyte solution to develop color. In a specific embodiment, the spectrophotometer measures the absorbance of the mixed electrolyte solution in the sealed tube 14 at a wavelength of 555 nm.

[0058] The present invention will be described in detail below through examples, but the protection scope of the present invention is not limited thereto.

[0059] Example 1

[0060] like Figure 1 As shown, a system for measuring the carbon dioxide content in flue gas from a stationary pollution source comprises an absorption pool 1 and an absorption container 13;

[0061] The inner top of the absorption cell 1 is provided with an atomizer 2, one input end of the atomizer 2 is connected with the absorption liquid pool 8 through an absorption liquid conveying device, the other input end is connected with the inner bottom of the absorption cell 1 through a circulating device, one side of the absorption cell 1 is connected with a sample gas conveying device, one side of the absorption cell 1 and the absorption container 13 are connected with a transfer device, a sealing tube 14 is arranged in the absorption container 13, the two ends of the sealing tube 14 connected with the absorption container 13 are transparent windows 15, a spectrophotometer is arranged at the transparent windows 15, the sealing tube 14 is filled with an electrolyte solution and an indicator, the inside of the absorption container 13 is provided with a temperature measuring element 19, and the material of the sealing tube 14 is a carbon dioxide selective permeation membrane. The carbon dioxide selective permeation membrane is a semi-permeable membrane containing polytetrafluoroethylene.

[0062] The absorption liquid conveying device comprises a conveying pipe 6 and a conveying pump 7, the input end and the output end of the conveying pump 7 are connected with the output end of the absorption liquid pool 8 and one input end of the atomizer 2 respectively through the conveying pipe 6. The circulating device comprises a circulating pipe 9 and a circulating pump 10, the input end and the output end of the circulating pump 10 are connected with the inner bottom of the absorption cell 1 and the other input end of the atomizer 2 respectively through the circulating pipe 9. The transfer device comprises a transfer pipe 11 and a transfer pump 12, the sample gas conveying device comprises a sample gas conveying pipe 3, a sample gas conveying pump 4 and a sampling device 5, the input end and the output end of the sample gas conveying pump 4 are connected with the output end of the sampling device 5 and one side of the absorption cell 1 respectively through the sample gas conveying pipe 3. The input end and the output end of the transfer pump 12 are connected with one side of the absorption cell 1 close to the bottom and the absorption container 13 respectively through the transfer pipe 11. The sampling device 5 comprises sampling equipment, dust filtering equipment and condensing equipment connected in sequence, one end of the condensing equipment is connected with the input end of the sample gas conveying pump 4 through the sample gas conveying pipe 3. Further comprising a timing device for controlling the absorption liquid conveying device, the circulating device and the sample gas conveying device to be opened or closed at a set time. The spectrophotometer comprises a light source 16, a monochromator 17 and a light detector 18, the light source 16 and the monochromator 17 are arranged at the transparent window 15 at one end of the sealing tube 14 in sequence, and the light detector 18 is arranged at the transparent window 15 at the other end of the sealing tube 14. The absorption liquid and the electrolyte solution are both sodium bicarbonate solutions, and the indicator is phenolphthalein.

[0063] The method for determining the carbon dioxide content in the flue gas of a stationary pollution source comprises the following steps: first, a sampling device obtains sample gas containing carbon dioxide in the flue gas of a stationary pollution source, and the obtained sample gas containing carbon dioxide is sequentially subjected to dust removal and condensation through a dust filtering device and a condensing device, and under the action of a sample gas conveying pump 4, the sample gas containing carbon dioxide after condensation treatment is conveyed through a sample gas conveying pipe 3 to an absorption cell 1 to replace the original gas in the absorption cell 1, and the replacement time is 30 s, after 30 s, the sample gas conveying device is closed, then under the action of a conveying pump 7, the absorption liquid in an absorption liquid cell 8 is conveyed through a conveying pipe 6 to an atomizer 2 to absorb the carbon dioxide in the absorption cell 1, and the conveying time is 10 s, after 10 s, the conveying pump 7 is closed, then under the action of a circulating pump 10, the liquid in the absorption cell 1 is circulated and conveyed through a circulating pipe 9 to the atomizer 2 for spraying, so as to further absorb the carbon dioxide in the absorption cell 1 to obtain a to-be-measured liquid, and the circulation time is 50 s, after 50 s, the circulating pump 10 is closed, then under the action of a transfer pump 12, the to-be-measured liquid in the absorption cell 1 is transferred through a transfer pipe 11 to an absorption container 13, and after the transfer is completed, the transfer pump 12 is closed, wherein the ions in the to-be-measured liquid penetrate into a sealed pipe 14 and mix with an electrolyte solution therein, the pH value of the mixed electrolyte solution changes, and under the action of an indicator, the mixed electrolyte solution develops color, finally, a spectrophotometer is used to measure the absorbance of the mixed electrolyte solution in the sealed pipe 14 at a wavelength of 555 nm, and the concentration of carbon dioxide is calculated based on the absorbance and the temperature.

[0064] It is detected that the average error rate of the carbon dioxide concentration determined by the method of the present application compared with the carbon dioxide concentration determined by the laboratory spectrophotometer method is only 0.38%, which has a very high application prospect.

[0065] The system for determining the carbon dioxide content in the flue gas of a stationary pollution source provided by the application obtains sample gas containing carbon dioxide through the sample gas conveying device, and conveys the obtained sample gas containing carbon dioxide to the absorption cell to replace the original gas in the absorption cell, conveys a certain amount of absorption liquid in the absorption liquid pool to the atomizer for spraying through the absorption liquid conveying device, and circulates and conveys the liquid in the absorption cell to the atomizer for spraying to obtain the liquid to be measured through the circulating device, and then conveys the liquid to be measured in the absorption cell to the absorption container through the transfer device, wherein the ions in the liquid to be measured penetrate into the sealed tube and mix with the electrolyte solution therein, the pH value of the mixed electrolyte solution changes, the color develops under the action of the indicator, finally the absorbance of the mixed electrolyte solution in the sealed tube is determined through the spectrophotometer, and the concentration of carbon dioxide is calculated based on the absorbance and the temperature. The continuous and accurate determination of the carbon dioxide content in the flue gas of a stationary pollution source is realized according to the needs, and the application has the advantages of simple operation and low cost.

[0066] The preferred embodiments of the application are described in detail above in combination with the drawings, but the application is not limited thereto. Within the technical concept of the application, various simple modifications can be made to the technical solutions of the application. In order to avoid unnecessary repetition, the application will not describe various possible combinations again. However, these simple modifications and combinations should also be regarded as the disclosed content of the application and belong to the protection scope of the application.

Claims

1. A system for measuring the carbon dioxide content in flue gas from a stationary pollution source, characterized in that: The system comprises an absorption tank (1) and an absorption container (13); An atomizer (2) is provided at the inner top of the absorption cell (1), one input end of the atomizer (2) is connected to the absorption liquid cell (8) via an absorption liquid delivery device, and the other input end is connected to the inner bottom of the absorption cell (1) via a circulation device, one side of the absorption cell (1) is connected to a sample gas delivery device, and a transfer device is connected between one side of the absorption cell (1) and the absorption container (13), a sealing tube (14) is provided through the absorption container (13), and both ends of the sealing tube (14) connected to the absorption container (13) are transparent windows (15), and a spectrophotometer is provided at the transparent window (15), an electrolyte solution and an indicator are contained in the sealing tube (14), and a temperature measuring element (19) is provided inside the absorption container (13); Wherein, the sealing tube (14) is made of a carbon dioxide selective permeable membrane; The spectrophotometer comprises a light source (16), a monochromator (17) and a light detector (18), wherein the light source (16) and the monochromator (17) are sequentially arranged at the transparent window (15) at one end of the sealed tube (14), and the light detector (18) is arranged at the transparent window (15) at the other end of the sealed tube (14); The absorption liquid and the electrolyte solution are both potassium bicarbonate solution or sodium bicarbonate solution, and the indicator is phenol red.

2. The system according to claim 1, wherein: The carbon dioxide selective permeation membrane is a semi-permeable membrane containing polytetrafluoroethylene or polyethylene.

3. The system according to claim 1, wherein: The absorption liquid conveying equipment comprises a conveying pipe (6) and a conveying pump (7); The input end and the output end of the delivery pump (7) are respectively connected to the output end of the absorption liquid pool (8) and an input end of the atomizer (2) through a delivery pipe (6).

4. The system according to claim 1, wherein: The circulation device includes a circulation pipe (9) and a circulation pump (10); The input end and the output end of the circulation pump (10) are respectively connected to the inner bottom of the absorption tank (1) and the other input end of the atomizer (2) through a circulation pipe (9).

5. The system according to claim 1, wherein: The transfer equipment includes a transfer pipe (11) and a transfer pump (12); The input end and the output end of the transfer pump (12) are respectively connected to the side of the absorption tank (1) close to the bottom and the absorption container (13) through a transfer pipe (11).

6. The system according to claim 1, wherein: The sample gas delivery equipment comprises a sample gas delivery pipe (3), a sample gas delivery pump (4) and a sampling device (5); The input end and the output end of the sample gas delivery pump (4) are respectively connected to the output end of the sampling device (5) and one side of the absorption cell (1) through the sample gas delivery pipe (3).

7. The system according to claim 6, characterized in that The sampling device (5) comprises a sampling device, a dust filtering device and a condensing device connected in sequence; One end of the condensation device is connected to the input end of the sample gas delivery pump (4) through the sample gas delivery pipe (3).

8. The system according to claim 1, wherein: It also includes a timing device for controlling the absorption liquid delivery device, the circulation device and the sample gas delivery device to be turned on or off at a set time.

9. A method for measuring the carbon dioxide content in flue gas from a stationary pollution source, characterized in that: The method is implemented using the system according to any one of claims 1 to 8, and the method comprises the following steps: S1. Using the sample gas delivery device to obtain a sample gas containing carbon dioxide, and delivering the obtained sample gas containing carbon dioxide to the absorption cell (1) to replace the original gas in the absorption cell (1), and when the gas in the absorption cell (1) is completely replaced, closing the sample gas delivery device; S2, using the absorption liquid conveying device to convey a certain amount of absorption liquid in the absorption liquid pool (8) to the atomizer (2) for spraying, and closing the absorption liquid conveying device after the conveying is completed; S3, using the circulation device to circulate the liquid in the absorption tank (1) to the atomizer (2) for spraying to obtain the liquid to be tested, and closing the circulation device after the cyclic spraying is completed; S4, using the transfer device to transfer the liquid to be tested in the absorption cell (1) to the absorption container (13), and closing the transfer device after the transfer is completed, wherein ions in the liquid to be tested penetrate into the sealed tube (14) and mix with the electrolyte solution therein, and the pH value of the mixed electrolyte solution changes, and color is displayed under the action of the indicator; S5. Using the spectrophotometer, measure the absorbance of the mixed electrolyte solution in the sealed tube (14), and calculate the concentration of carbon dioxide based on the absorbance and temperature.

10. The method according to claim 9, characterized in that The wavelength at which the spectrophotometer measures the absorbance of the mixed electrolyte solution in the sealed tube (14) is 555 nm.

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