CN110006876A - Carbon dioxide gas detection device and detection method - Google Patents

Abstract

The invention discloses a carbon dioxide gas detection device and a detection method. The detection device includes a detection unit, a liquid circuit unit, a gas circuit unit and a control unit. The detection unit includes a light-proof casing, a tubular gas-liquid interface reactor and a photoelectric detection sensor. The shell has a light-shielding cavity, and the tubular gas-liquid interface reactor and the photoelectric detection sensor are arranged in the light-shielding cavity. The liquid circuit unit includes an infusion module and a liquid storage module connected with the liquid inlet and the liquid outlet. The air extraction module connected with the air outlet, the control unit is electrically connected with the photoelectric detection sensor of the detection unit, the infusion module in the liquid circuit unit and the air extraction module in the air circuit unit. The carbon dioxide gas detection method adopts the carbon dioxide gas tubular detection device to detect the carbon dioxide gas concentration. Based on the gas-liquid interface chemiluminescence technology, the invention realizes high-sensitivity on-line detection of carbon dioxide gas, has low cost, high speed, and high accuracy and stability.

Description

A kind of carbon dioxide gas detection device and detection method

technical field

The present invention relates to the technical field of chemiluminescence detection, and more particularly, to a carbon dioxide gas detection device and a detection method.

Background technique

At present, non-dispersive infrared absorption method is generally used for the detection of carbon dioxide gas, which has low detection cost, simple operation and fast detection speed, and can realize continuous online measurement. However, this method is easily affected by the interference of moisture and aerosols in the gas during the detection process, and the error is large, and its accuracy and stability are difficult to guarantee. Gas-liquid interface chemiluminescence detection technology is a highly sensitive detection method, which has been successfully applied to the online detection of nitrogen dioxide, ozone, sulfur dioxide, formaldehyde and other trace gases in the atmosphere. Compared with traditional detection methods, the technology has the advantages of low detection cost and simple equipment structure, and has good application prospects. However, the technology has not yet been applied to the detection of carbon dioxide gas.

In practical application of gas-liquid interface chemiluminescence detection technology, a specific reaction bed structure is required to provide a flowing gas-liquid reaction interface to realize gas-liquid interface chemiluminescence reaction. In the previous technology, the reaction bed generally uses high hydrophilic film materials (such as silk, filter paper, PP fiber non-woven fabric, polyester fiber cloth, etc.), which has the advantage of providing a larger reaction interface to obtain higher detection sensitivity. However, the high hydrophilicity and high wettability of this type of reaction bed mainly depend on the multi-dimensional three-dimensional structure supported by its inner microfibers. With the repeated use of the reaction bed, the multi-dimensional structure inside the reaction bed will gradually harden and collapse, making its hydrophilicity and wettability gradually worsened. At the same time, because this kind of reaction bed is soft and has certain tensile ductility, it is difficult to fix it in the reactor evenly and evenly, and the consistency is poor and the detection performance of the equipment is affected.

SUMMARY OF THE INVENTION

In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a carbon dioxide gas detection device and a detection method, which better realize the high-sensitivity online detection of carbon dioxide gas based on the gas-liquid interface chemiluminescence technology.

An aspect of the present invention provides a carbon dioxide gas detection device, the detection device includes a detection unit, a liquid circuit unit, a gas circuit unit and a control unit, wherein,

The detection unit includes a light-shielding casing, a tubular gas-liquid interface reactor and a photoelectric detection sensor, the light-shielding casing has a light-shielding cavity, and the tubular gas-liquid interface reactor and the photoelectric detection sensor are arranged in the light-shielding cavity. in vivo;

The tubular gas-liquid interface reactor includes an upper joint, a lower joint, a transparent pipe body, a fiber column and an isolation sleeve. The upper joint is provided with a liquid inlet, a liquid inlet channel, an air outlet and an air outlet, and the lower joint is provided with an outlet. The liquid port, the liquid outlet channel, the air inlet and the air inlet channel, and a transparent pipe body is connected between the upper joint and the lower joint;

The fiber column is arranged in the transparent pipe body, and both ends of the fiber column are fixedly installed in the liquid inlet channel and the liquid outlet channel respectively; the isolation sleeve is arranged on the outer surface of the fiber column, and one of the isolation sleeves is The side is provided with an opening; an annular cavity is formed between the transparent tube body and the fiber column, and the annular cavity communicates with the air inlet channel and the air outlet channel and communicates with the fiber column through the opening of the isolation sleeve ; The photosensitive portion of the photoelectric detection sensor faces the transparent tube body of the tubular gas-liquid interface reactor and faces the opening of the isolation sleeve.

The liquid circuit unit includes a liquid infusion module and a liquid storage module connected with the liquid inlet and the liquid outlet;

The air circuit unit includes an air extraction module connected with the air outlet;

The control unit is electrically connected with the photoelectric detection sensor of the detection unit, the infusion module in the liquid circuit unit and the air extraction module in the air circuit unit.

According to an embodiment of the carbon dioxide gas detection device of the present invention, the light-shielding casing includes a light-shielding case and a light-shielding front cover, and the light-shielding shell and the light-shielding front cover are assembled to form a light-shielding cavity with a light-shielding cavity. The outer shell, the light-shielding front cover is provided with holes corresponding to the upper joint and the lower joint of the tubular gas-liquid interface reactor, and the tubular gas-liquid interface reactor is fixed on the light-shielding front cover.

According to an embodiment of the carbon dioxide gas detection device of the present invention, an annular groove is provided at the positions where the upper joint and the lower joint are connected to the transparent pipe body, and the transparent pipe body is installed in the annular groove and sealed and fixed , Among them, the transparent tube body is installed with black silica gel perfusion.

According to an embodiment of the carbon dioxide gas detection device of the present invention, the upper joint and the lower joint are made of opaque and corrosion-resistant materials, and the air outlet channel of the upper joint and the air inlet channel of the lower joint are tubular channels with the inner diameter and transparent The inner diameter of the tube body is the same.

According to an embodiment of the carbon dioxide gas detection device of the present invention, the isolation sleeve is made of opaque corrosion-resistant material, the outer diameter of the fiber column is smaller than the inner diameter of the isolation sleeve and smaller than the inner diameter of the transparent pipe body, The fiber column is vertically installed at the central position of the transparent pipe body, and the fiber column is made of rigid PP fiber column, wherein the part of the fiber column corresponding to the opening of the isolation sleeve is concave to form a platform.

According to an embodiment of the carbon dioxide gas detection device of the present invention, the liquid storage module includes a first reagent storage subunit, a second reagent storage subunit, a cleaning reagent storage subunit, and a waste liquid collection subunit, and the infusion module includes A reagent pump and a cleaning pump, and the pumping module includes a pumping pump.

According to an embodiment of the carbon dioxide gas detection device of the present invention, the reagent pump is a three-channel miniature ball-type peristaltic pump, and the first reagent storage subunit and the second reagent storage subunit pass through the two channels of the reagent pump and the The liquid inlet is connected to the liquid outlet, and the liquid outlet is connected to the waste liquid collection subunit through another channel of the reagent pump; the cleaning pump is a dual-channel miniature ball-type peristaltic pump, and the cleaning reagent storage subunit passes through one channel of the cleaning pump. The channel is connected with the liquid inlet, and the liquid outlet is connected with the waste liquid collection subunit through another channel of the cleaning pump.

Another aspect of the present invention provides a method for detecting carbon dioxide gas, using the above-mentioned carbon dioxide gas detecting device to detect the concentration of carbon dioxide gas.

According to an embodiment of the carbon dioxide gas detection method of the present invention, the detection method comprises the following steps:

Step 1: Assemble the detection device, continuously control the liquid circuit unit to pass the detection reagent into the liquid inlet channel of the tubular gas-liquid interface reactor through the liquid inlet, and draw the detection reagent from the liquid outlet channel and discharge the tubular type through the liquid outlet. A gas-liquid interface reactor, wherein the detection reagent includes a first reagent and a second reagent, the first reagent is a hydrogen peroxide solution, the second reagent is a mixed solution of potassium hydroxide and potassium carbonate, the first reagent and the second reagent The inlet flow rate of the reagents is the same and the outlet flow rate is slightly greater than the sum of the inlet flow rates of the first reagent and the second reagent;

Step 2: control the gas circuit unit to pass the detection gas into the air inlet channel of the tubular gas-liquid interface reactor through the air inlet, and lead the reacted gas from the gas outlet channel and discharge the tubular gas-liquid interface reactor through the air outlet;

Step 3: Detect the chemiluminescence signal generated by the gas-liquid interface chemiluminescence reaction in the tubular gas-liquid interface reactor through a photoelectric detection sensor and convert it into an electrical signal, and record and calculate the actual concentration of carbon dioxide;

Step 4: After the detection, the control liquid circuit unit passes the cleaning reagent into the liquid inlet channel of the tubular gas-liquid interface reactor through the liquid inlet, and leads the cleaning reagent from the liquid outlet channel and discharges the tubular gas-liquid interface through the liquid outlet. The reactor is cleaned, wherein the cleaning reagent is a mixture of deionized water, ethanol and glycerol, and the outflow flow rate of the cleaning agent is 3 to 5 times the inflow flow rate.

Compared with the prior art, the present invention provides a carbon dioxide gas detection device and a detection method, which realizes high-sensitivity online detection of carbon dioxide gas based on the gas-liquid interface chemiluminescence technology. Compared with the current technology, it will not be affected by moisture and aerosols and will not be affected by other interfering gases in the ambient gas. The detection cost is low, the detection speed is fast, and it has high accuracy and stability.

Description of drawings

FIG. 1 shows a schematic diagram of the overall connection structure of a carbon dioxide gas detection device according to an exemplary embodiment of the present invention.

FIG. 2 shows a schematic structural diagram of a detection unit in a carbon dioxide gas detection device according to an exemplary embodiment of the present invention.

3 shows a schematic structural diagram of a tubular gas-liquid interface reactor of a detection unit in a carbon dioxide gas detection device according to an exemplary embodiment of the present invention.

Description of reference numbers:

1-detection unit; 11-light-proof front cover, 111-liquid inlet hole, 112-liquid outlet hole, 113-air outlet hole, 114-inlet hole; 12-tubular gas-liquid interface reactor, 121-upper joint, 122-lower joint, 123-isolation sleeve, 1231-opening part, 124-fiber column, 1241-platform part, 125-transparent pipe body, 126-annular groove, 127-annular cavity, 1211-liquid inlet , 1212-air outlet, 1213-liquid inlet channel, 1214-air outlet channel, 1221-liquid outlet, 1222-inlet port, 1223-liquid outlet channel, 1224-inlet channel; 13-light-proof housing, 14- Photoelectric detection sensor;

2-liquid circuit unit, 21-liquid storage module, 211-first reagent storage subunit, 212-second reagent storage subunit, 213-waste liquid collection subunit, 214-cleaning reagent storage subunit; 22-infusion module , 221-reagent pump, 222-cleaning pump; 3-air circuit unit, 4-control unit.

Detailed ways

All features disclosed in this specification, or all disclosed steps in a method or process, may be combined in any way except mutually exclusive features and/or steps.

Any feature disclosed in this specification, unless expressly stated otherwise, may be replaced by other equivalent or alternative features serving a similar purpose. That is, unless expressly stated otherwise, each feature is but one example of a series of equivalent or similar features.

The carbon dioxide gas detection device of the present invention will be specifically described below with reference to the accompanying drawings.

FIG. 1 shows a schematic diagram of the overall connection structure of a carbon dioxide gas detection device according to an exemplary embodiment of the present invention.

As shown in FIG. 1 , according to an exemplary embodiment of the present invention, the carbon dioxide gas detection device includes a detection unit 1 , a liquid circuit unit 2 , a gas circuit unit 3 and a control unit 4 , wherein the detection unit 1 uses a gas-liquid phase The main components of the interface chemiluminescence detection technology to detect carbon dioxide, the liquid circuit unit 2 is used to provide and recover reagents or cleaning reagents to the detection unit 1, the gas circuit unit 3 is used to provide detection gas to the detection unit 1, and the control unit 3 controls the detection The action of the device and the detection of carbon dioxide are realized.

FIG. 2 shows a schematic structural diagram of a detection unit in a carbon dioxide gas detection device according to an exemplary embodiment of the present invention.

As shown in FIG. 2 and FIG. 3 , the detection unit 1 of the present invention includes a light-shielding casing, a tubular gas-liquid interface reactor 12 and a photoelectric detection sensor 14. The light-shielding casing has a light-shielding cavity, and the tubular gas-liquid interface reactor has a light-shielding cavity. 12 and the photoelectric detection sensor 14 are arranged in the light-shielding cavity. Among them, the gas-liquid interface chemiluminescence reaction of the detection gas occurs in the tubular gas-liquid interface reactor 12, the photoelectric detection sensor 5 detects the chemiluminescence signal and converts it into an electrical signal and outputs it, and the light-shielding shell provides protection for the reaction and detection. light environment.

3 shows a schematic structural diagram of a tubular gas-liquid interface reactor of a detection unit in a carbon dioxide gas detection device according to an exemplary embodiment of the present invention.

As shown in FIG. 3 , the tubular gas-liquid interface reactor includes an upper joint 121 , a lower joint 122 , a transparent pipe body 125 , a fiber column 124 and an isolation sleeve 123 , and the upper joint 121 is provided with a liquid inlet 1211 and a liquid inlet channel 1213 , an air outlet 1212 and an air outlet channel 1214 , the lower joint 122 is provided with a liquid outlet 1221 , a liquid outlet channel 1223 , an air inlet 1222 and an air inlet channel 1224 .

Preferably, the light-shielding shell includes a light-shielding housing 13 and a light-shielding front cover 11 , the light-shielding shell 13 and the light-shielding front cover 11 are assembled to form a light-shielding shell having a light-shielding cavity, and the light-shielding front cover 11 is provided with The holes corresponding to the upper joint 121 and the lower joint 122 of the tubular gas-liquid interface reactor 12 are fixed on the light-shielding front cover 11 .

The upper joint 121 and the lower joint 122 are preferably made of opaque corrosion-resistant materials. After installation, the light-shielding shell 13 is assembled with the light-shielding front cover 11 to form a light-shielding cavity. The interior of the tubular gas-liquid interface reactor 12 The cavity is communicated with the external liquid circuit unit 2 and the air circuit unit 3 through the liquid inlet hole 111, the liquid outlet hole 112, the air outlet hole 113 and the air inlet hole 114 on the light-proof front cover 11, and the external light will not pass through the gas-liquid circuit system. Entering the light-proof cavity and the tubular gas-liquid interface reactor will not affect the detection results.

According to the present invention, a transparent pipe body 125 is connected between the upper joint 121 and the lower joint 122, the fiber column 124 is arranged in the transparent pipe body 125, and both ends of the fiber column 124 are fixedly installed in the liquid inlet channel 1213 and the liquid outlet channel 1223 respectively. The isolation sleeve 123 is arranged on the outer surface of the fiber column 124, and one side of the isolation sleeve 123 is provided with an opening 1231; an annular cavity 127 is formed between the transparent pipe body 125 and the fiber column 124, and the annular cavity 127 communicates with the air inlet channel 1224 and the air outlet channel 1214 and communicates with the fiber column 124 through the opening 1231 of the isolation sleeve 123; It faces the opening 1231 of the spacer sleeve 123 .

Wherein, an annular groove 126 is provided at the positions where the upper connection 121 and the lower joint 122 are connected with the transparent pipe body 125 , and the transparent pipe body 125 is installed in the annular groove 126 and sealed and fixed. Preferably, the transparent tube body 125 is filled with black silica gel when it is installed.

In addition, the air outlet channel 1214 of the upper joint 121 and the air inlet channel 1224 of the lower joint 122 are tubular channels and the inner diameter is the same as the inner diameter of the transparent pipe body 125, then when the transparent pipe body 125 is installed between the upper and lower joints, a connected air path is formed Channels, where there is no dead volume at the connection and does not affect the flow of gas.

The two ends of the fiber column 124 are respectively placed in the liquid inlet channel 1213 and the liquid outlet channel 1223 of the upper and lower joints. Thus, the reagent liquid participating in the reaction enters the liquid inlet channel 1213 from the liquid inlet 1211 of the upper joint 121, reaches the top of the fiber column 124, and is evenly distributed in the fiber column under the capillary action and gravity of the ultrafine fibers contained in the fiber column. The surface and interior of the column 124 flow from the top end of the fiber column 124 to the bottom end of the fiber column 124 with the continuous addition of the liquid, and flow out from the liquid outlet 1221 through the liquid outlet channel 1223 .

Wherein, if the outer diameter of the fiber column 124 is smaller than the inner diameter of the transparent tube body 125 and smaller than the inner diameter of the isolation sleeve 123, an annular cavity 127 can be formed between the transparent tube body 125 and the fiber column 124, and is installed in the isolation sleeve within 123. The fiber column is preferably made of hard PP fiber column, which has good hydrophilicity, is not easily deformed and damaged, is easy to clean, and is easy to install and disassemble.

According to the present invention, the outer surface of the fiber column 124 is provided with an isolation sleeve 123, and one side of the isolation sleeve 123 is provided with an opening 1231. The specific structure is shown in FIG. 2 . Specifically, on the one hand, the isolation sleeve 123 can prevent the airflow from the oblique direction of the air inlet channel from having a greater impact on the liquid distributed on the fiber column 124, resulting in uneven distribution of the liquid or even detaching from the fiber column to form droplets into the gas The road channel contaminates the reactor and the subsequent gas circuit system, and at the same time, it can prevent the premature contact between the liquid and the gas to produce a reaction and affect the detection effect; on the other hand. The partially open isolation sleeve 123 can protect the fiber column and improve the efficiency of the reaction. Under the action of the isolation sleeve 123 , the liquid on the fiber column 124 can only come into contact with the gas and react and be detected when it is exposed from the opening 1231 and faces the position of the photosensitive portion of the photoelectric detection sensor 14 .

The isolation sleeve 123 is preferably made of opaque material, which is beneficial to improve the light-proof effect; the isolation sleeve 123 is preferably made of corrosion-resistant material to prevent chemical reaction when contacting gas and liquid, which affects the use effect or detection. Effect. Preferably, the isolation sleeve 123 is a heat shrinkable tube made of black polytetrafluoroethylene. In addition, preferably, a portion of the fiber column 124 corresponding to the opening portion 1231 of the isolation sleeve 123 is concave to form a platform portion 1240, which can produce better response and detection effects.

The isolation sleeve 123 can support and fix the fiber column 124 well, and there is a gap like an opening at the position facing the photoelectric detection sensor 14, which can ensure that the gas and the detection reagent can contact and generate a chemiluminescence reaction at this position. . In the position facing away from the photoelectric detection sensor, the isolation sleeve is used for gas-liquid isolation to prevent the occurrence of gas-liquid reaction. This is beneficial to improve the effective utilization of detection reagents and gas-liquid reaction, and the exposed part of the fiber column is concave to form a platform part, which can effectively prevent the liquid from the gas-liquid contact reaction from leaving the fiber column and entering the gas path to contaminate the detector and the gas path. .

The transparent tube body 125 used in the present invention has a tubular structure, preferably a high-purity quartz tube with a tubular structure.

As shown in FIG. 3 , the liquid circuit unit 2 of the present invention includes a liquid infusion module 22 and a liquid storage module connected to the liquid inlet 1211 and the liquid outlet 1221 through the liquid inlet hole 111 and the liquid outlet hole 112 on the light-shielding front cover 11 . 21, wherein the liquid inlet hole 111 communicates with the liquid inlet channel 1211, and the liquid outlet hole 112 communicates with the liquid outlet channel 1221. The air circuit unit 3 of the present invention includes an air extraction module connected to the air outlet 1212 through the air outlet 113 on the light-shielding front cover 11. Of course, the air inlet 114 on the light-shielding front cover 11 is directly connected to the gas source to be detected.

The liquid storage module 21 includes a first reagent storage sub-unit 211, a second reagent storage sub-unit 212, a cleaning reagent storage sub-unit 214 and a waste liquid collection sub-unit 213, the infusion module 22 includes a reagent pump 221 and a cleaning pump 222, and an air extraction module Includes air pump. The control unit 4 is electrically connected to the photoelectric detection sensor 14 of the detection unit 1 , the infusion module 22 of the liquid circuit unit 2 and the air extraction module of the gas circuit unit 3 to realize automatic control during detection.

Preferably, the reagent pump 221 used in the present invention is a three-channel miniature ball-type peristaltic pump, and the first reagent storage subunit 211 and the second reagent storage subunit 212 are respectively connected to the liquid inlet 1211 through two channels of the reagent pump 221 . , the liquid outlet 1221 is connected to the waste liquid storage sub-unit 213 through another channel of the reagent pump 221, thereby forming an input channel for the detection reagent, and the first reagent and the second reagent can enter the tube under the action of the reagent pump 221 respectively. type gas-liquid interface reactor and discharge after detection reaction.

Similarly, the cleaning pump 222 is a dual-channel miniature ball-type peristaltic pump, the cleaning reagent storage subunit 214 is connected to the liquid inlet 1211 through one channel of the cleaning pump 222 , and the liquid outlet 1221 is connected to the waste liquid through another channel of the cleaning pump 222 . The collecting subunits 213 are connected to form an input channel for cleaning reagents, and the cleaning reagents can enter the tubular gas-liquid interface reactor under the action of the cleaning pump 222 and be discharged after cleaning the reactor.

The present invention also provides a method for detecting carbon dioxide gas, which adopts the above-mentioned carbon dioxide gas detecting device to detect the concentration of carbon dioxide gas.

Specifically, the detection method may include the following steps:

step 1:

Assemble the detection device, continuously control the liquid circuit unit to pass the detection reagent into the liquid inlet channel of the tubular gas-liquid interface reactor through the liquid inlet, and draw the detection reagent from the liquid outlet channel and discharge the tubular gas-liquid interface through the liquid outlet reactor.

With the continuous entry of the detection reagent, the detection reagent is evenly distributed on the surface and inside of the fiber column under the capillary action of the fiber column and the action of gravity, and moves down to the liquid outlet channel, and then discharges the tubular gas-liquid interface through the liquid outlet. reactor.

Wherein, the carbon dioxide detection reagent used in the present invention includes a first reagent and a second reagent, the first reagent is a hydrogen peroxide solution, and the second reagent is a mixed solution of potassium hydroxide and potassium carbonate. And during detection, preferably, the inlet flow rates of the first reagent and the second reagent are the same and the outlet flow rate is slightly greater than the sum of the inlet flow rates of the first reagent and the second reagent.

Step 2:

The control gas circuit unit passes the detection gas into the inlet channel of the tubular gas-liquid interface reactor through the inlet port, and draws the reacted gas from the gas outlet channel and exits the tubular gas-liquid interface reactor through the gas outlet port.

As a result, the carbon dioxide in the gas to be tested entering the tubular gas-liquid interface reactor will react with the detection reagent on the surface of the fiber column exposed from the opening of the isolation sleeve to generate a chemiluminescence signal, and the reacted gas will be released from the gas outlet. Discharge tubular gas-liquid interface reactor.

Step 3:

The photoelectric detection sensor detects the chemiluminescence signal generated by the gas-liquid interface chemiluminescence reaction in the tubular gas-liquid interface reactor, converts it into an electrical signal, and records and calculates the actual concentration of carbon dioxide.

Step 4:

After the detection, the control liquid circuit unit will pass the cleaning reagent into the liquid inlet channel of the tubular gas-liquid interface reactor through the liquid inlet, and lead the cleaning reagent from the liquid outlet channel and discharge the tubular gas-liquid interface reactor through the liquid outlet. cleaning,

Wherein, the cleaning reagent can be a mixed solution of deionized water, ethanol and glycerol. During the cleaning process, preferably, the outflow flow rate of the cleaning reagent is controlled to be 3 to 5 times the inflow flow rate.

The present invention will be further described below in conjunction with specific carbon dioxide detection examples.

Example:

The carbon dioxide detection device of the present invention is used to detect the concentration of carbon dioxide in the air.

Preparation of detection reagents: boil deionized water for 30 minutes and then naturally cool to room temperature to prepare the first reagent and the second reagent, wherein the first reagent is hydrogen peroxide solution, and the concentration of hydrogen peroxide is: 0.0001～1mol /L, the concentration of hydrogen peroxide is preferably 0.1mol/L; the second reagent is a mixed solution of potassium hydroxide and potassium carbonate, the concentration of potassium hydroxide is 0.0001～1mol/L, and the concentration of potassium carbonate is 0.0001～1mol/L L, the concentration of potassium hydroxide is preferably 0.5 mol/L, and the concentration of potassium carbonate is preferably 0.25 mol/L.

Preparation of cleaning reagent: Dissolve glycerol in a mixture of deionized water and ethanol to prepare a cleaning solution, wherein the mixing ratio of deionized water and ethanol is 1:1, and the volume concentration of glycerol is 5%.

Detection of nitrogen dioxide gas: under the action of the reagent pump, the first reagent and the second reagent are drawn from the corresponding reagent storage sub-unit into the liquid pipeline at a flow rate of 30ul/min, and mixed at the back end of the reagent pump , the mixed mixed reagent enters the liquid inlet channel of the tubular gas-liquid interface reactor. As the detection reagent continues to enter, the detection reagent contacts the fiber column and is evenly distributed on the surface and inside of the fiber column under the action of capillary action and gravity, and moves down to the liquid outlet channel, and with the reverse channel of the reagent pump At a flow rate of about 80-100ul/min (slightly larger than the sum of the two-way detection reagent flow), it is drawn out of the detection unit and collected in the waste liquid storage sub-unit.

The control air circuit unit draws air into the air inlet channel of the tubular gas-liquid interface reactor from the air inlet, and draws the reacted gas from the air outlet channel and discharges the tubular air-liquid interface reactor through the air outlet. The carbon dioxide in the air entering the tubular gas-liquid interface reactor will react with the mixed detection reagent on the surface of the fiber column exposed from the opening of the isolation sleeve to generate a chemiluminescence signal, and the reacted gas will be discharged from the gas outlet of the tubular gas. Liquid interface reactor.

The gas-liquid interface chemiluminescence signal in the tubular gas-liquid interface reactor is detected by the photoelectric detection sensor and converted into an electrical signal, and the actual concentration of carbon dioxide is recorded and calculated. The formula for calculating nitrogen dioxide concentration is: C=kS+b, where C is the actual concentration value of carbon dioxide measured, S is the output signal of the photoelectric detection sensor, k and b are constants, which can pass the carbon dioxide standard of different concentration levels The luminescence signal measured by the gas was obtained by linear fitting.

After the detection, the control liquid circuit unit will pass the cleaning reagent into the liquid inlet channel of the tubular gas-liquid interface reactor through the liquid inlet, and lead the cleaning reagent from the liquid outlet channel and discharge the tubular gas-liquid interface reactor through the liquid outlet. cleaning. The cleaning process is generally 10min, and the cleaning speed is about 200ul/min.

The carbon dioxide gas detection device and the detection method of the present invention realize the real-time online continuous detection of carbon dioxide gas with high sensitivity and high time resolution based on the gas-liquid interface chemiluminescence technology, and the detection sensitivity can reach below ppmv level. Compared with the currently commonly used non-dispersive infrared absorption spectroscopy technology, it is not affected by ambient moisture, aerosols, and other interfering gases, and has low detection cost, fast detection speed, and high accuracy and stability.

The present invention is not limited to the foregoing specific embodiments. The present invention extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims (9)

1. A carbon dioxide gas detection device, characterized in that the detection device comprises a detection unit, a liquid circuit unit, a gas circuit unit and a control unit, wherein, The detection unit includes a light-shielding casing, a tubular gas-liquid interface reactor and a photoelectric detection sensor, the light-shielding casing has a light-shielding cavity, and the tubular gas-liquid interface reactor and the photoelectric detection sensor are arranged in the light-shielding cavity. in vivo; The tubular gas-liquid interface reactor includes an upper joint, a lower joint, a transparent pipe body, a fiber column and an isolation sleeve. The upper joint is provided with a liquid inlet, a liquid inlet channel, an air outlet and an air outlet, and the lower joint is provided with an outlet. The liquid port, the liquid outlet channel, the air inlet and the air inlet channel, and a transparent pipe body is connected between the upper joint and the lower joint; The fiber column is arranged in the transparent pipe body, and both ends of the fiber column are fixedly installed in the liquid inlet channel and the liquid outlet channel respectively; the isolation sleeve is arranged on the outer surface of the fiber column, and one of the isolation sleeves is The side is provided with an opening; an annular cavity is formed between the transparent tube body and the fiber column, and the annular cavity communicates with the air inlet channel and the air outlet channel and communicates with the fiber column through the opening of the isolation sleeve ; The photosensitive portion of the photoelectric detection sensor faces the transparent tube body of the tubular gas-liquid interface reactor and faces the opening of the isolation sleeve. The liquid circuit unit includes a liquid infusion module and a liquid storage module connected with the liquid inlet and the liquid outlet; The air circuit unit includes an air extraction module connected with the air outlet; The control unit is electrically connected with the photoelectric detection sensor of the detection unit, the infusion module in the liquid circuit unit and the air extraction module in the air circuit unit. 2. The carbon dioxide gas detection device according to claim 1, wherein the light-shielding housing comprises a light-shielding casing and a light-shielding front cover, and the light-shielding casing and the light-shielding front cover are assembled to form a light-shielding front cover. The light-shielding shell of the cavity, the light-shielding front cover is provided with holes corresponding to the upper joint and the lower joint of the tubular gas-liquid interface reactor, and the tubular gas-liquid interface reactor is fixed in the shielding. Light front cover. 3. The carbon dioxide gas detection device according to claim 1, wherein an annular groove is provided at the positions where the upper joint and the lower joint are connected with the transparent pipe body, and the transparent pipe body is installed in the annular groove It is sealed and fixed inside, and the transparent tube body is filled with black silica gel when it is installed. 4. The carbon dioxide gas detection device according to claim 1, wherein the upper joint and the lower joint are made of opaque corrosion-resistant materials, and the air outlet passage of the upper joint and the air inlet passage of the lower joint are tubular The inner diameter of the channel is the same as that of the transparent tube body, and the transparent tube body is a high-purity quartz tube with a tubular structure. 5 . The carbon dioxide gas detection device according to claim 1 , wherein the isolation sleeve is made of opaque corrosion-resistant material, and the outer diameter of the fiber column is smaller than the inner diameter of the isolation sleeve and smaller than the transparent sleeve. 6 . The inner diameter of the pipe body, the fiber column is vertically installed at the central position of the transparent pipe body, and the fiber column is made of hard PP fiber column, wherein the fiber column is in the part corresponding to the opening of the isolation sleeve. The concave forms a platform portion. 6. The carbon dioxide gas detection device according to claim 1, wherein the liquid storage module comprises a first reagent storage subunit, a second reagent storage subunit, a cleaning reagent storage subunit and a waste liquid collection subunit, The infusion module includes a reagent pump and a cleaning pump, and the air extraction module includes an air extraction pump. 7 . The carbon dioxide gas detection device according to claim 6 , wherein the reagent pump is a three-channel miniature ball-type peristaltic pump, and the first reagent storage subunit and the second reagent storage subunit pass through the reagent pump respectively. 8 . The two channels of the pump are connected to the liquid inlet, and the liquid outlet is connected to the waste liquid collection subunit through another channel of the reagent pump; the cleaning pump is a dual-channel miniature ball-type peristaltic pump, and the cleaning reagent storage subunit passes through the One channel of the cleaning pump is connected to the liquid inlet, and the liquid outlet is connected to the waste liquid collecting subunit through another channel of the cleaning pump. 8. A carbon dioxide gas detection method, characterized in that the carbon dioxide gas detection device according to any one of claims 1 to 7 is used to detect the carbon dioxide gas concentration. 9. carbon dioxide gas detection method according to claim 8, is characterized in that, described detection method comprises the following steps: Step 1: Assemble the detection device, continuously control the liquid circuit unit to pass the detection reagent into the liquid inlet channel of the tubular gas-liquid interface reactor through the liquid inlet, and draw the detection reagent from the liquid outlet channel and discharge the tubular type through the liquid outlet. A gas-liquid interface reactor, wherein the detection reagent includes a first reagent and a second reagent, the first reagent is a hydrogen peroxide solution, the second reagent is a mixed solution of potassium hydroxide and potassium carbonate, the first reagent and the second reagent The inlet flow rate of the reagents is the same and the outlet flow rate is slightly greater than the sum of the inlet flow rates of the first reagent and the second reagent; Step 2: control the gas circuit unit to pass the detection gas into the air inlet channel of the tubular gas-liquid interface reactor through the air inlet, and lead the reacted gas from the gas outlet channel and discharge the tubular gas-liquid interface reactor through the air outlet; Step 3: Detect the chemiluminescence signal generated by the gas-liquid interface chemiluminescence reaction in the tubular gas-liquid interface reactor through a photoelectric detection sensor and convert it into an electrical signal, and record and calculate the actual concentration of carbon dioxide; Step 4: After the detection, the control liquid circuit unit passes the cleaning reagent into the liquid inlet channel of the tubular gas-liquid interface reactor through the liquid inlet, and leads the cleaning reagent from the liquid outlet channel and discharges the tubular gas-liquid interface through the liquid outlet. The reactor is cleaned, wherein the cleaning reagent is a mixture of deionized water, ethanol and glycerol, and the outflow flow rate of the cleaning agent is 3 to 5 times the inflow flow rate.