1. A detect little leakage device of octafluoro-isobutylene which characterized in that: the method comprises the following steps:

a collection device for collecting a gas sample;

a chromatographic separation device (4) connected with the collection device and used for separating octafluoroisobutylene from the gas sample;

the driving device is used for generating driving gas and driving the gas to be detected to enter the chromatographic separation device;

and the detection device is used for detecting the concentration of the octafluoroisobutylene.

2. The apparatus for detecting micro-leakage of octafluoroisobutylene as claimed in claim 1, wherein: the chromatographic separation device comprises a first separation unit (1) for separating a fluoride sample from the gas sample, a second separation unit (2) for separating C4F8 from the fluoride sample, and a third separation unit (3) for separating octafluoroisobutylene from the C4F 8.

3. The device for detecting the micro-leakage of the octafluoroisobutylene as claimed in claim 2, wherein: and a chromatographic column box (5) is arranged outside the third separation unit (3), and the chromatographic column box (5) is connected with a refrigerator (6).

4. The apparatus for detecting micro-leakage of octafluoroisobutylene as claimed in claim 1, wherein: the driving device includes: the device comprises a carrier gas cylinder (7), a pressure reducer (8) connected with an output port of the carrier gas cylinder (7) and a gas purifier (9) connected with an output end of the pressure reducer (8); the output end of the gas purifier (9) is communicated with the input end of the chromatographic separation device (4).

5. The device for detecting the micro-leakage of the octafluoroisobutylene as claimed in claim 4, wherein: the collecting device comprises: a collection chamber (10) for taking a gas sample and a gas circulation pump (11) in communication with the collection chamber (10); the gas circulating pump (11) is communicated with the input end of the chromatographic separation device (4).

6. The apparatus for detecting micro-leakage of octafluoroisobutylene as claimed in claim 5, wherein: the gas circulation pump (11) is externally sleeved with a sealing box (12), one side of the sealing box (12) is communicated with the output end of the pressure reducer (8), and the other side of the sealing box (12) is communicated with a waste gas discharge pipeline (13).

7. The apparatus for detecting micro-leakage of octafluoroisobutylene as claimed in claim 5, wherein: the input end of the chromatographic separation device (4) is provided with a gas switching valve (14), and the output ends of the gas circulating pump (11) and the gas purifier (9) are connected with the input end of the gas switching valve (14);

and a quantitative ring (15) is arranged in the gas switching valve (14).

8. The apparatus for detecting micro-leakage of octafluoroisobutylene as claimed in claim 1, wherein: the detection device includes: the detection module is communicated with the output end of the chromatographic separation device (4); the output end of the detection module is connected with a signal processing unit (16), and the output end of the signal processing unit (16) is connected with an upper computer (17);

the signal processing unit (16) is configured to: the concentration data detected by the detection module are obtained, converted into electric signals and sent to the upper computer (17);

the detection module comprises: a PED detector (18) and a TCD detector (19).

9. The apparatus for detecting micro-leakage of octafluoroisobutylene according to claim 8, wherein: the input end of the signal processing unit (16) is also connected with a PID detector (23), and the PID detector (23) is arranged outside the chromatographic separation device (4); and an alarm (20) is arranged at the output end of the signal processing unit (16).

10. A method for detecting a leakage amount by using the apparatus for detecting a micro leakage of octafluoroisobutylene according to any one of claims 1 to 9, characterized in that: the method comprises the following steps:

obtaining the volume V of the collecting device, and obtaining the concentration A of the gas sample;

at t₁At the moment, the concentration U of the octafluoroisobutylene is detected by the detection device₁；

At t₂At the moment, the concentration U of the octafluoroisobutylene is detected by the detection device₂；

Calculating the cumulative time Deltat as t₂-t₁(ii) a Cumulative concentration Δ U ═ U₂-U₁；

Calculating leakage quantity Q_Sheet：

Q_Sheet＝△U·V/(△t-△U·△t)。

Background

Various toxic and harmful substances (such as the production process of fluorides such as hexafluoropropylene, tetrafluoroethylene and the like) can be generated in the petrochemical production process, and one fluoride with the highest toxic hazard in the reactants and the final products in the process is octafluoroisobutylene (PFIB for short). Octafluoroisobutylene, one of the strictly regulated chemical hazards of the international chemical weapons agreement (CWC), is more than 10 times more toxic than phosgene, and reacts rapidly with and stimulates the lungs, causing pulmonary edema and even death. Therefore, in the fluoride production process, the problems of leakage of production devices, raw material pipelines and output pipelines, on-line detection and protection of toxic and harmful gases and the like need to be paid great attention.

At present, the total content of fluorine elements in the air is monitored as a detection standard in a fluoride production field, so that the total content of the fluorine elements is not over standard easily, and the relative content of octafluoroisobutylene is high; when the total content monitoring threshold value is continuously adjusted down, the situation of false alarm is easy to occur.

Disclosure of Invention

In view of the above-mentioned drawbacks and deficiencies of the prior art, it is desirable to provide an apparatus for detecting a micro-leakage of octafluoroisobutylene and a method for detecting a leakage amount thereof.

In a first aspect, the present application provides a device for detecting micro-leakage of octafluoroisobutylene, comprising:

a collection device for collecting a gas sample;

the chromatographic separation device is connected with the collection device and is used for separating octafluoroisobutylene from the gas sample;

the driving device is used for generating driving gas and driving the gas to be detected to enter the chromatographic separation device;

and the detection device is used for detecting the concentration of the octafluoroisobutylene.

According to the technical scheme provided by the embodiment of the application, the chromatographic separation device comprises a first separation unit for separating a fluoride sample from the gas sample, a second separation unit for separating C4F8 from the fluoride sample, and a third separation unit for separating octafluoroisobutylene from the C4F 8.

According to the technical scheme provided by the embodiment of the application, a chromatographic column box is arranged outside the third separation unit and connected with a refrigerating machine.

According to the technical scheme provided by the embodiment of the application, the driving device comprises: the gas purifier comprises a carrier gas cylinder, a pressure reducer connected with an output port of the carrier gas cylinder and a gas purifier connected with an output end of the pressure reducer; the output end of the gas purifier is communicated with the input end of the chromatographic separation device.

According to the technical scheme provided by the embodiment of the application, the collecting device comprises: the gas sampling device comprises a collection chamber for acquiring a gas sample and a gas circulating pump communicated with the collection chamber; the gas circulating pump is communicated with the input end of the chromatographic separation device.

According to the technical scheme that this application embodiment provided, the outside cover of gas circulating pump is equipped with the seal box, one side of seal box with pressure reducer output intercommunication, the opposite side intercommunication of seal box has the exhaust emission pipeline.

According to the technical scheme provided by the embodiment of the application, a gas switching valve is arranged at the input end of the chromatographic separation device, and the output ends of the gas circulating pump and the gas purifier are connected with the input end of the gas switching valve;

and a quantitative ring is arranged in the gas switching valve.

According to the technical scheme provided by the embodiment of the application, the detection device comprises: the detection module is communicated with the output end of the chromatographic separation device; the output end of the detection module is connected with a signal processing unit, and the output end of the signal processing unit is connected with an upper computer;

the signal processing unit is configured to: acquiring concentration data detected by the detection module, converting the concentration data into an electric signal and sending the electric signal to the upper computer;

the detection module comprises: PED detectors and TCD detectors.

According to the technical scheme provided by the embodiment of the application, the input end of the signal processing unit is also connected with a PID detector, and the PID detector is arranged outside the chromatographic separation device; and an alarm is arranged at the output end of the signal processing unit.

In a second aspect, the present application provides a method for detecting a leakage amount by using the above-mentioned apparatus for detecting a micro-leakage of octafluoroisobutylene, comprising the following steps:

obtaining the volume V of the collecting device, and obtaining the concentration A of the gas sample;

at t₁At the moment, the concentration U of the octafluoroisobutylene is detected by the detection device₁；

At t₂At the moment, the concentration U of the octafluoroisobutylene is detected by the detection device₂；

Calculating the cumulative time Deltat as t₂-t₁(ii) a Cumulative concentration Δ U ═ U₂-U₁；

Calculating leakage quantity Q_Sheet：

Q_Sheet＝△U·V/(△t-△U·△t)。

The beneficial effect of this application lies in: based on the technical scheme provided by the application, in the using process, the gas sample at the point to be measured or the sealing position is collected through the collecting device; starting the driving device, wherein the driving device generates driving gas to drive the gas sample to enter the chromatographic separation device, and mixed gas flows out according to different separation time under the separation action of the chromatographic separation device; the concentration of the octafluoroisobutylene can be detected by the detection device.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, made with reference to the accompanying drawings in which:

FIG. 1 is a schematic diagram of an apparatus for detecting micro-leakage of octafluoroisobutylene in accordance with the present application;

FIG. 2 is a gas circuit connection diagram of a device for detecting micro-leakage of octafluoroisobutylene according to the present application;

FIG. 3 is a perspective view of the apparatus for detecting a micro-leak of octafluoroisobutylene shown in FIG. 1.

Reference numbers in the figures:

1. a first separation unit; 2. a second separation unit; 3. a third separation unit; 4. a chromatographic separation device; 5. a chromatographic column box; 6. a refrigerator; 7. a carrier gas cylinder; 8. a pressure reducer; 9. a gas purifier; 10. a collection chamber; 11. a gas circulation pump; 12. a sealing box; 13. an exhaust gas discharge line; 14. a gas switching valve; 15. a dosing ring; 16. a signal processing unit; 17. an upper computer; 18. a PED detector; 19. a TCD detector; 20. an alarm; 21. a circulation pipe; 22. a flow controller; 23. a PID detector; 24. installing a shell; 25. a moving wheel; 26. a six-way valve; 27. a first exhaust duct; 28. a second exhaust conduit; 29. a carrier gas line; 30. the sample gas enters the pipeline.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

Example 1

Please refer to fig. 1, which is a schematic diagram of an apparatus for detecting micro-leakage of octafluoroisobutylene provided in the present application, comprising:

a collection device for collecting a gas sample;

the chromatographic separation device 4 is connected with the collection device and is used for separating octafluoroisobutylene from the gas sample;

the driving device is used for generating driving gas and driving the gas to be detected to enter the chromatographic separation device;

and the detection device is used for detecting the concentration of the octafluoroisobutylene.

Specifically, as shown in fig. 3, the apparatus for detecting micro-leakage of octafluoroisobutylene further comprises a mounting case 24, and the collecting device, the chromatographic separation device 4, the driving device and the detecting device are all mounted on the mounting case 24; preferably, the bottom of the mounting housing 24 is provided with a rotating structure, such as a turntable; the movable wheel 25 is installed at the bottom of the rotary table, so that the device for detecting the micro-leakage of the octafluoroisobutylene can be translated or rotated, and the requirement of field detection is met.

In particular, the collecting device is used for collecting a gas sample at a point to be measured of a petrochemical production device or a sealing position of the petrochemical production device.

Specifically, the chromatographic separation device 4 is used for gas separation, so that the finally separated octafluoroisobutylene and isomers thereof can flow out sequentially according to the separation time, and the concentration value can be detected by a detection device.

In addition, the leakage amount value of the petrochemical production device can be calculated through the following steps:

obtaining the volume V of the collecting device, and obtaining the concentration A of the gas sample; at t₁At the moment, the concentration U of the octafluoroisobutylene is detected by the detection device₁(ii) a At t₂At the moment, the concentration U of the octafluoroisobutylene is detected by the detection device₂(ii) a Calculating the cumulative time Deltat as t₂-t₁(ii) a Cumulative concentration Δ U ═ U₂-U₁(ii) a Calculating leakage quantity Q_Sheet：

Q_Sheet＝△U·V/(△t-△U·△t)。

The working principle is as follows: in the using process, collecting a gas sample at a point to be measured or a sealing position through the collecting device; starting the driving device, generating driving gas by the driving device to drive the gas sample to enter the chromatographic separation device 4, and allowing the mixed gas to flow out according to different separation time under the separation action of the chromatographic separation device 4; the concentration of the octafluoroisobutylene can be detected by the detection device.

Wherein, in a preferred embodiment of the chromatographic separation device 4, the chromatographic separation device comprises a first separation unit 1 for separating a fluoride sample from the gas sample, a second separation unit 2 for separating C4F8 from the fluoride sample, and a third separation unit 3 for separating octafluoroisobutylene from the C4F 8.

Specifically, the first separation unit 1 includes a pretreatment column (MXT-Q-BOND) for separating fluoride and other air in the gas sample; the second separation unit 2 comprises a fluoride separation column (MXT-1) for separating C4F8 from other gases in the fluoride; the third separation unit comprises an octafluoroisobutylene isomer separation column (MXT-1) which can separate octafluoroisobutylene from other isomers at a low temperature, i.e., octafluoroisobutylene is completely separated from octafluorobutene-1, octafluorobutene-2 and octafluorocyclobutane.

Preferably, a six-way valve 26 is arranged between the second chromatographic column and the third chromatographic column, and a first exhaust pipeline 27 is arranged at the other output end of the six-way valve 26; since C4F8 has a different separation time from the fluoride, the separated C4F8 enters the third separation unit by controlling the opening and closing of the different valves of the six-way valve 26, and the rest of the fluoride sample is discharged along the first gas discharge pipe 27.

In a preferred embodiment of the third separation unit, a column box 5 is provided outside the third separation unit 3, and a refrigerator 6 is connected to the column box 5.

Specifically, the refrigerator 6 is a semiconductor refrigerator, and is configured to provide refrigeration to the chromatography column box 5, so that the third chromatography column is in a constant-20 ℃ environment.

Wherein, in a preferred embodiment of the driving device, the driving device comprises: the gas purifier comprises a carrier gas cylinder 7, a pressure reducer 8 connected with an output port of the carrier gas cylinder 7 and a gas purifier 9 connected with an output port of the pressure reducer 8; the output of the gas purifier 9 is in communication with the input of the chromatographic separation device 4.

Specifically, the pressure of the high-pressure gas in the carrier gas cylinder 1 is adjusted to 0.7MPa to 0.9MPa through a pressure reducer 8; and the driving gas is purified by the gas purifier 9, so that the measurement error is reduced.

Wherein, in a preferred embodiment of the collecting device, the collecting device comprises: a collection chamber 10 for taking a gas sample and a gas circulation pump 11 in communication with said collection chamber 10; the gas circulation pump 11 is in communication with the input of the chromatographic separation device 4.

Specifically, when in use, a circulating pump with high sealing performance can be adopted to pump the gas at the position to be detected on the fluoride production device into the collection chamber 10.

Specifically, two ends of the gas circulation pump 11 are provided with circulation pipelines 21 communicated with the collection chamber 10, so that a gas sample can circulate in the circulation pipelines; while the gas circulation pump 11 is also in communication with the chromatographic separation device 4 for providing the gas sample to the input of the separation device 4.

In a preferred embodiment of the gas circulation pump 11, a sealed box 12 is sleeved outside the gas circulation pump 11, one side of the sealed box 12 is communicated with the output end of the pressure reducer 8, and the other side of the sealed box 12 is communicated with an exhaust gas discharge pipeline 13.

Through the structure, the output end of the pressure reducer 8 can convey gas into the sealed box 12 and discharge the gas through the waste gas discharge pipeline 13; through the blowdown processing for when 11 knecks of gas circulating pump produced the trace and leak, can get into exhaust emission pipeline 13 along with the gas of pressure reducer 8 output, avoid the measurement personnel to inhale, improved the security.

In a preferred embodiment of the chromatographic separation device 4, a gas switching valve 14 is provided at an input end of the chromatographic separation device 4, and the gas circulation pump 11 and output ends of the gas purifier 9 are connected to an input end of the gas switching valve 14;

a quantitative ring 15 is installed in the gas switching valve 14.

Specifically, the gas switching valve 14 may adopt a six-way valve, an eight-way valve or a ten-way valve; a quantitative ring 15 is arranged in the gas switching valve 14, so that the gas sample enters the quantitative ring 15, the gas switching valve 14 is opened, and the gas sample in the quantitative ring 15 is output with the gas purifier 9 to drive the gas to enter the chromatographic separation device 4.

Specifically, a flow controller 22 is arranged between the chromatographic separation device and the gas purifier 9, and the flow controller is used for adjusting the flow of the driving gas and controlling the flow of the driving gas within the range of 5ml/min to 200 ml/min.

Specifically, the output end of the gas switching valve 14 is further connected to a second exhaust pipe 28, and since the fluoride and the rest of the gas have different separation times, by controlling the opening and closing of different valves of the gas switching valve 14, the separated fluoride sample enters the second separation unit 2, and the rest of the gas is discharged along the second exhaust pipe in a center cutting manner.

Wherein, in a preferred embodiment of the detection device, the detection device comprises: the detection module is communicated with the output end of the chromatographic separation device 4; the output end of the detection module is connected with a signal processing unit 16, and the output end of the signal processing unit 16 is connected with an upper computer 17;

the signal processing unit 16 is configured to: acquiring concentration data detected by the detection module, converting the concentration data into an electric signal and sending the electric signal to the upper computer 17;

the detection module comprises: PED detector 18 and TCD detector 19.

Specifically, the PED detector 18 is a plasma emission spectrum detector, and the detection range is ppb-ppm; the TCD detector 19 is a thermal conductivity detector, and the detection range is ppm [% ].

Specifically, the upper computer 17 is connected with the gas switching valve 14, so that the gas switching valve 14 can be controlled by the upper computer 17 to perform gas path switching. The on-line detection of the fluoride production field can be realized, and the leakage of octafluoro isobutylene on a fluoride production device can be remotely detected on line.

The working principle is as follows: the PED detector 18 and the TCD detector 19 detect the concentration value of the octafluoroisobutylene output by the chromatographic separation device 4, the signal processing unit 19 converts the concentration value data into an electric signal and sends the electric signal to the upper computer 17 for displaying, and then the value of the leakage amount can be further calculated. The structure can detect the concentration change of the octafluoroisobutylene in the ppb to percent range in the air environment, and the minimum leakage quantity of pipelines, valves and sealed containers can be detected to be not less than 0.001 ml/s.

In a preferred embodiment of the signal processing unit 16, the input end of the signal processing unit 16 is further connected to a PID detector 23, and the PID detector 23 is disposed outside the chromatographic separation device 4; an alarm 20 is mounted at the output end of the signal processing unit 16.

In particular, the safety of detection personnel is ensured; by installing the PID detector 23 for detecting the change in the concentration of hydrocarbons in the environment surrounding the device. Once the fluoride production site has large leakage or toxic and harmful gas in the micro-leakage device has leakage, the concentration of hydrocarbon around the micro-leakage detection device is increased, and when the change concentration exceeds a set threshold value, the alarm 20 immediately gives an alarm and flickers to remind detection personnel of protection or evacuation.

Specifically, the PID detector is a photoionization sensor, and can detect volatile organic compounds and toxic and harmful gases within a ppb-100 ppm range in real time.

Specifically, the chromatographic separation devices 4 may be provided in two groups, and the output end of each group of the chromatographic separation devices 4 is provided with different detectors, as shown in fig. 2:

the driving gas in the gas carrier bottle 1 enters the gas switching valve 14 through the gas loading pipeline 29, and the gas sample in the collection chamber 10 enters the quantitative ring 15 in the gas switching valve 14 through the sample gas inlet pipeline 30; opening a gas switching valve, enabling a gas sample in the quantitative ring 15 to enter the first separation unit 1 along with the driving gas, enabling the separated fluoride gas to enter the second separation unit 2, and discharging the separated air through a second exhaust pipeline 28; similarly, C4F8 separated in the second separation unit 2 enters the third separation unit 3, and the rest of the separated chloride is discharged along the first exhaust gas pipe 27 on the six-way valve 26; the octafluoroisobutylene can be separated from the C4F8 gas through a third separation unit, and is qualitatively or quantitatively detected through a TCD detector and a PED detector respectively, and finally discharged through a waste gas discharge pipeline 13.

Example 2:

the embodiment provides a method for detecting leakage amount by using the device for detecting micro leakage of octafluoroisobutylene, which comprises the following steps:

obtaining the volume V of the collecting device, and obtaining the concentration A of the gas sample;

at t₁At the moment, the concentration U of the octafluoroisobutylene is detected by the detection device₁；

At t₂At the moment, the concentration U of the octafluoroisobutylene is detected by the detection device₂；

Calculating the cumulative time Deltat as t₂-t₁(ii) a Cumulative concentration Δ U ═ U₂-U₁；

Calculating leakage quantity Q_Sheet：

Q_Sheet＝△U·V/(△t-△U·△t)。

According to the method for detecting the leakage amount, the octafluoroisobutylene micro-leakage device is utilized, the concentration of the octafluoroisobutylene detected by the detection device is obtained at different moments, and the leakage amount of the octafluoroisobutylene can be rapidly obtained according to the volume of the collection device, the concentration of the gas sample and the response value of the gas sample.

The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by a person skilled in the art that the scope of the invention as referred to in the present application is not limited to the embodiments with a specific combination of the above-mentioned features, but also covers other embodiments with any combination of the above-mentioned features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.