Sampling pipeline leakproofness monitoring device and analyzer

Abstract

The utility model discloses a sampling pipeline leakproofness monitoring device and an analyzer, and belongs to the technical field of analyzers, the sampling pipeline leakproofness monitoring device comprises a blowback device, a sampling probe, a remote controller and an analyzer, the sample outlet end of the sampling probe is sequentially connected with a two-position three-way valve, a first sampling three-way valve and the analyzer through pipelines to form a first sampling loop; a second sampling loop is arranged on a connecting pipeline between the first sampling three-way valve and the two-position three-way valve in parallel; a blowback air source is connected to the first sampling loop through a filter pressure reducer and a first pressure transmitter in sequence, and the first pressure transmitter is connected with a first sampling three-way valve through a pipeline; the remote controller is electrically connected with the analyzer, the first pressure transmitter, the first sampling three-way valve and the two-position three-way valve. The utility model has the beneficial effects that the use condition of equipment can be known in time, the occurrence of faults can be controlled in time, a large amount of manpower can be saved, the fault response efficiency can be improved, and safe and stable production can be realized.

Description

Technical Field

[0001] The utility model belongs to the technical field of analyzers, and in particular relates to a sampling pipeline airtightness monitoring device and an analyzer. Background Art

[0002] Analytical instruments are one of the main branches of testing instruments. With the development of science and technology and the increase in the demand for online testing, the portability, miniaturization and diversification of analytical instruments have become the development trend of analytical instruments today. Split-type gas sampling analyzers have been widely used in existing industrial fields to monitor gas control indicators, waste gas emissions and other parameters within the production system. They mainly track and monitor the content of various harmful substances and different components contained in the gas in real time, and take corresponding control measures in a timely manner based on the monitoring results. The quality of the sampled gas is directly related to the accuracy of the monitoring results, which in turn affects the normal control of the production process. Since the sampling probe of the production site analyzer is at a certain distance from the analyzer itself, sampling lines and various plug interfaces are used to connect the distance to achieve sampling and analysis of the sample gas.

[0003] At present, there is a lack of effective monitoring methods for the sealing of the sampling loop between the analyzer probe and the analyzer itself. When the interface is loose, blocked, or the pipeline is cracked or damaged in the middle of the sampling loop, the fault phenomenon cannot be accurately judged, resulting in the sampling loop being connected to the atmosphere, allowing air to enter the sampling loop, thereby affecting the measurement results of the analyzer. In addition, there may be a certain degree of uncertainty in the content of various substances in the external atmosphere. When they are extracted into the sampling loop, the measurement data will be completely distorted, thereby affecting normal control judgment and causing certain harm to the equipment itself.

[0004] Some patents in the field of analyzer technology are disclosed in the prior art. Among them, the utility model patent with the announcement number CN217505313U discloses a sampling device and an analyzer, which includes a sampling probe, a first sampling three-way valve, a second sampling three-way valve, a purge three-way valve, a differential pressure transmitter and a controller; the sample outlet end of the sampling probe is connected to the first end of the first sampling three-way valve through a pipeline; the second end of the first sampling three-way valve is connected to the first end of the second sampling three-way valve through a pipeline to form a first sampling loop, and the third end of the first sampling three-way valve is connected to the second sampling three-way valve through a pipeline. The second end of the sampling three-way valve is connected to form a second sampling loop; the third end of the second sampling three-way valve is connected to the first end of the purge three-way valve through a pipeline; the second end of the purge three-way valve is the gas source input end, and the third end of the purge three-way valve is the sample outlet end of the sampling device; one end of the differential pressure transmitter is connected to the pipeline between the first sampling three-way valve and the sampling probe through a pipeline, and the other end of the differential pressure transmitter is connected to the pipeline between the second sampling three-way valve and the purge three-way valve through a pipeline; the controller is respectively connected to the first sampling three-way valve, the second sampling three-way valve, the purge three-way valve and the differential pressure transmitter. Although the problem of not being able to detect the blockage of the sampling pipeline in time is solved, the problem of better regular testing and comparison monitoring of the airtightness of the sampling loop is not solved.

[0005] In view of this, the inventor conducted in-depth research on the need to regularly test and compare the airtightness of the sampling loop, which resulted in the present case. Utility Model Content

[0006] In order to overcome the problem that the analyzer in the prior art periodically tests and compares the airtightness of the sampling circuit, the utility model provides a sampling pipeline airtightness monitoring device, including a backflush device, a sampling probe, a first sampling three-way valve, a two-position three-way valve, a remote controller and an analyzer, wherein the sample outlet end of the sampling probe is connected to the two-position three-way valve, the first sampling three-way valve and the analyzer in sequence through a pipeline to form a first sampling circuit, and a second sampling circuit is provided in parallel on the connecting pipeline between the first sampling three-way valve and the two-position three-way valve;

[0007] The backblowing device includes a backblowing gas source, a filter pressure reducer and a first pressure transmitter. The backblowing gas source is connected to the first sampling circuit through the filter pressure reducer and the first pressure transmitter in sequence. The first pressure transmitter is connected to the first sampling three-way valve through a pipeline; the remote controller is electrically connected to the analyzer, the first pressure transmitter, the first sampling three-way valve, and the two-position three-way valve respectively.

[0008] The remote monitoring and identification technology has been adopted to timely understand the use of equipment and to promptly control the occurrence of faults. It is more suitable for operation monitoring of instruments installed in high-altitude, remote, dangerous and other locations that are difficult for manpower to reach, as well as instruments involving important production parameters such as gas and environmental protection. It is conducive to saving a lot of manpower, improving fault response efficiency, and is extremely beneficial to safe and stable production.

[0009] Further, a second pressure transmitter and a standard gas source are provided at one end of the first sampling loop close to the sampling probe, the second pressure transmitter and the standard gas source are connected to the pipeline of the first sampling loop through the two-position three-way valve, and a first two-way valve is provided between the two-position three-way valve and the sampling probe;

[0010] The second pressure transmitter and the first two-way valve are electrically connected to the remote controller respectively.

[0011] Furthermore, both ends of the second sampling loop are connected to the pipeline of the first sampling loop through a second sampling three-way valve and a third sampling three-way valve, respectively; the second sampling three-way valve is connected to the pipeline close to the analyzer; and the second sampling three-way valve and the third sampling three-way valve are electrically connected to the remote controller, respectively.

[0012] Furthermore, a first back-blow circuit is formed between the first sampling three-way valve and the first pressure transmitter, and a three-position two-way purge valve is arranged on the first back-blow circuit, the back-blow gas source is connected to the middle section of the first sampling circuit through the three-position two-way purge valve to form a second back-blow circuit, the back-blow gas source is connected to the middle section of the second sampling circuit through the three-position two-way purge valve to form a third back-blow circuit, and the three-position two-way purge valve is electrically connected to the remote controller.

[0013] Furthermore, the first sampling circuit and the second sampling circuit are connected in parallel to an exhaust three-way valve for pipeline pressure reduction.

[0014] Furthermore, the second backflush circuit is connected to the first sampling circuit through a first purge three-way valve, the third backflush circuit is connected to the second sampling circuit through a second purge three-way valve, and the first purge three-way valve and the second purge three-way valve are electrically connected to the remote controller respectively.

[0015] Furthermore, a second two-way valve is provided on the pipeline between the first sampling three-way valve and the analyzer, and a check valve is provided between the standard gas source and the two-position three-way valve.

[0016] Furthermore, the back-blowing air source includes a first back-blowing air source and a second back-blowing air source, and the junction of the first back-blowing air source and the second back-blowing air source is connected to the filter pressure reducer through a remote-controlled three-way valve, and an air source control valve is provided on the pipeline between the remote-controlled three-way valve and the filter pressure reducer; the remote-controlled three-way valve and the air source control valve are electrically connected to the remote controller respectively.

[0017] Furthermore, the remote controller is also connected to an alarm unit, and the alarm unit is electrically connected to the controller.

[0018] The utility model also provides an analyzer, comprising the sampling pipeline airtightness monitoring device.

[0019] Beneficial effects:

[0020] The beneficial effects produced by adopting the technical solution of the utility model are as follows:

[0021] (1) Remote monitoring and identification technology is adopted to timely understand the use of equipment and timely control the occurrence of faults. It is more suitable for the operation monitoring of instruments installed in high-altitude, remote, dangerous and other places that are difficult for manpower to reach, as well as instruments involving important production parameters such as gas and environmental protection. It is conducive to saving a lot of manpower, improving fault response efficiency, and is extremely conducive to safe and stable production.

[0022] (2) Under normal sampling conditions, if the sampling loop is airtight, the standard gas will be sampled from the sampling pipeline to the analyzer, and the analyzer will correctly display the component content of the standard gas source. If the analyzer detection value does not correspond to the standard gas source content value within the set sampling comparison monitoring time range, it is considered that the sampling pipeline is airtight. The use of the sampling pipeline airtightness secondary judgment system can also be used as a means to monitor the measurement accuracy of the analyzer. By comparing the displayed values, the accuracy of the analyzer can be judged.

[0023] (3) The remote controller mainly realizes the remote control of various valves, analyzes the pressure values ​​collected on site and the values ​​monitored by the analyzer, and is responsible for the programming and automatic control of various control programs. It realizes the self-inspection of the air tightness of the sampling pipeline through the analysis of the collected values, and transmits the detected abnormalities to each monitoring point to notify the inspection personnel. At the same time, it can connect with the mobile phone APP to transmit the alarm information to the designated personnel, so as to realize the first-time discovery of fault information and timely resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solution of the implementation mode of the utility model, the drawings required for use in the implementation mode will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a structural schematic diagram of a sampling pipeline tightness monitoring device and an analyzer of the utility model;

[0026] In the figure, 1. sampling probe; 2. first sampling three-way valve; 3. two-position three-way valve; 4. analyzer; 5. back-blowing gas source; 6. filter pressure reducer; 7. first pressure transmitter; 8. second pressure transmitter; 9. standard gas source; 10. first two-way valve; 11. second sampling three-way valve; 12. third sampling three-way valve; 13. purge three-position two-way valve; 14. exhaust three-way valve; 15. first purge three-way valve; 16. second purge three-way valve; 17. second two-way valve; 18. check valve; 19. first back-blowing gas source; 20. second back-blowing gas source; 21. remote control three-way valve; 22. gas source control valve. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the utility model for which protection is sought, but merely represents the selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0028] This implementation adopts remote monitoring and identification technology, which can timely understand the use of equipment and enable timely control of faults. It is more suitable for the operation monitoring of instruments installed in high-altitude, remote, dangerous and other places that are difficult for manpower to reach, and instruments involving important production parameters such as gas and environmental protection. It is conducive to saving a lot of manpower, improving fault response efficiency, and is extremely conducive to safe and stable production. The specific implementation is as follows:

[0029] like Figure 1As shown, a sampling pipeline airtightness monitoring device comprises a backflush device, a sampling probe 1, a first sampling three-way valve 2, a two-position three-way valve 3, a remote controller and an analyzer 4, wherein the sample outlet end of the sampling probe 1 is sequentially connected to the two-position three-way valve 3, the first sampling three-way valve 2 and the analyzer 4 via a pipeline to form a first sampling circuit, and a second sampling circuit is provided in parallel on the connecting pipeline between the first sampling three-way valve 2 and the two-position three-way valve 3;

[0030] The backblowing device includes a backblowing gas source 5, a filter pressure reducer 6 and a first pressure transmitter 7. The backblowing gas source 5 is connected to the first sampling circuit through the filter pressure reducer 6 and the first pressure transmitter 7 in sequence. The first pressure transmitter 7 is connected to the first sampling three-way valve 2 through a pipeline; the remote controller is electrically connected to the analyzer 4, the first pressure transmitter 7, the first sampling three-way valve 2, and the two-position three-way valve 3 respectively.

[0031] Here, a filter pressure reducer 6 is arranged between the backblowing gas source 5 and the first pressure transmitter 7. The gas of the backblowing gas source 5 is filtered by the filter pressure reducer 6 to remove internal moisture and impurities. At the same time, the pressure of the gas source entering the sampling loop is adjusted by adjusting the pressure reducer according to on-site needs. The pressure detection value range in the system is controlled according to the reference pressure entering the loop and the pressure loss inside the pipeline.

[0032] In addition, the remote controller can be set to receive the loop pressure monitoring numerical signal monitored on site, and compare and analyze the received value with the set normal value to judge the sealing of the on-site sampling control loop. When the transmitted pressure is within a reasonable range, it proves that the on-site sampling loop is normally sealed. When the transmitted pressure is too low, it proves that the on-site sampling control loop may be blocked or leaking. An abnormal pressure alarm will be issued immediately, and then the standard gas source 9 will be compared through the set automatic control program. If it still exceeds the normal range, the comprehensive alarm program will be triggered to isolate the existing sampling pipeline to prevent external gas from entering the analyzer 4.

[0033] Furthermore, a second pressure transmitter 8 and a standard gas source 9 are provided at one end of the first sampling loop close to the sampling probe 1. The second pressure transmitter 8 and the standard gas source 9 are connected to the pipeline of the first sampling loop through a two-position three-way valve 3. A first two-way valve 10 is provided between the two-position three-way valve 3 and the sampling probe 1; the second pressure transmitter 8 and the first two-way valve 10 are electrically connected to the remote controller respectively.

[0034] Here, the second pressure transmitter 8 can be set according to the pressure level of the compressed air used on site and the pressure loss of the end monitoring point. In addition, the level of the remote pressure transmitter KPA or MPA is reasonably selected, and the appropriate connection mode internal thread connection, external thread connection, plug connection, clamp connection and explosion-proof level are selected in combination with the structural characteristics of its body. For places where there are flammable and explosive hazards on site and outdoor installation is required, its explosion-proof, waterproof and dustproof levels are reasonably selected.

[0035] In addition, the standard gas source 9 is used for secondary detection of the loop sealing. After the pressure detection is abnormal, the standard gas source 9 is introduced to detect whether the standard gas source 9 can smoothly reach the on-site analyzer 4, so as to be used for more accurate monitoring and judgment of the pipeline sealing.

[0036] Furthermore, both ends of the second sampling loop are connected to the pipeline of the first sampling loop through the second sampling three-way valve 11 and the third sampling three-way valve 12 respectively. The second sampling three-way valve 11 is connected to the pipeline close to the analyzer 4. The second sampling three-way valve 11 and the third sampling three-way valve 12 are electrically connected to the remote controller respectively.

[0037] Furthermore, a first back-blow circuit is formed between the first sampling three-way valve 2 and the first pressure transmitter 7, and a three-position two-way purge valve 13 is arranged on the first back-blow circuit. The back-blow gas source 5 is connected to the middle section of the first sampling circuit through the three-position two-way purge valve 13 to form a second back-blow circuit. The back-blow gas source 5 is connected to the middle section of the second sampling circuit through the three-position two-way purge valve 13 to form a third back-blow circuit. The three-position two-way purge valve 13 is electrically connected to the remote controller.

[0038] Here, the second pressure transmitter 8 can more accurately reflect the pressure value at the sampling probe 1 during the backblowing process, so that the pressure loss from the initial end to the terminal end can be more accurately monitored, making the judgment value more reliable. The pipeline laying selects pipelines and joints with corresponding pressure levels according to the compressed air level on site. At the same time, the materials are selected according to the actual situation on site to be corrosion-resistant, wear-resistant, antifreeze and high temperature resistant.

[0039] Furthermore, the first sampling loop and the second sampling loop are connected in parallel to an exhaust three-way valve 14 for reducing the pressure of the pipeline.

[0040] Furthermore, the second backflush circuit is connected to the first sampling circuit through the first purge three-way valve 15, and the third backflush circuit is connected to the second sampling circuit through the second purge three-way valve 16. The first purge three-way valve 15 and the second purge three-way valve 16 are electrically connected to the remote controller respectively.

[0041] Furthermore, a second two-way valve 17 is provided on the pipeline between the first sampling three-way valve 2 and the analyzer 4 , and a check valve 18 is provided between the standard gas source 9 and the two-position three-way valve 3 .

[0042] Furthermore, the back-blowing air source 5 includes a first back-blowing air source 19 and a second back-blowing air source 20. The junction of the first back-blowing air source 19 and the second back-blowing air source 20 is connected to the filter pressure reducer 6 through a remote-controlled three-way valve 21. An air source control valve 22 is provided on the pipeline between the remote-controlled three-way valve 21 and the filter pressure reducer 6; the remote-controlled three-way valve 21 and the air source control valve 22 are electrically connected to the remote controller respectively.

[0043] In the specific implementation, the two back-blowing air sources 5 are both sent to the remote-controlled three-way valve 21, and the remote-controlled three-way valve 21 keeps one air source connected to the outlet. The first pressure transmitter 7 at the rear is used as the outlet pressure detection point to transmit the actual air source pressure output value to the remote control system. When the pressure of the air source used is abnormal and does not meet the set limit range value, the remote controller will prompt an alarm and control the remote-controlled three-way valve 21 to switch to another air source to ensure the effective supply of the air source. The installed air source control valve 22 serves as an isolation device between the air source supply device and the sampling circuit. During the sampling process, the air source control valve 22 is closed for purging and pressure testing and opened when it is opened. When maintenance is required or an abnormality occurs, the air source control valve 22 can be remotely controlled for isolation. The purging three-position two-way valve 13 realizes the purging isolation switching of the main road and the two branches, and the air filter pressure reducer 6 plays the role of air circuit pressure regulation and air source filtering and sewage discharge.

[0044] Furthermore, the remote controller is also connected to an alarm unit, and the alarm unit is electrically connected to the controller.

[0045] Here, the system alarm signal is output to promptly remind the monitoring personnel, and the alarm is pushed to the mobile phone APP of the main contact via wireless transmission.

[0046] The utility model also provides an analyzer 4, comprising a sampling pipeline airtightness monitoring device.

[0047] In specific implementation, the first sampling three-way valve 2 controls the switching between the sampling and back-blowing states. When sampling normally, the back-blowing gas source 5 is disconnected from the access side, and the remote controller remotely controls the second two-way valve 17 to open, and remotely controls the second sampling three-way valve 11, the third sampling three-way valve 12, the first purge three-way valve 15, and the second purge three-way valve 16 to cooperate to realize the switching of the first sampling circuit and the second sampling circuit. When the first sampling circuit is used, the second sampling three-way valve 11, the third sampling three-way valve 12 and the first purge three-way valve 15 are remotely controlled to open to keep the pipeline unobstructed, and the second sampling circuit is remotely controlled to open to keep the pipeline unobstructed. The connection sides of the second sampling three-way valve 11 and the third sampling three-way valve 12 of the remote sampling circuit and the remote control three-way valve 21 are in a closed state, and the remote control exhaust three-way valve 14 is closed; when the second sampling circuit is used, the connection sides of the second remote sampling three-way valve 11 and the third sampling three-way valve 12 and the second purge three-way valve 16 are opened to keep the pipeline unobstructed, the connection sides of the second sampling three-way valve 11 and the third sampling three-way valve 12 and the first purge three-way valve 15 of the remote control first sampling circuit are in a closed state, and the remote control exhaust three-way valve 14 is disconnected.

[0048] When the system is in the purge pressure check state, the remote controller remotely controls the first sampling three-way valve 2 to open, the first sampling three-way valve 2 cuts off the gas path connected to the second two-way valve 17, and at the same time remotely controls the second two-way valve 17 to close, the purge three-position two-way valve 13 is connected to the first sampling three-way valve 2, the back-blowing gas source 5 and the second sampling circuit side pipeline are unblocked, and the remote controller purges and pressure checks the sampling circuit behind the second sampling three-way valve 11.

[0049] During specific implementation, while ensuring normal operation, when purging the first back-blow circuit where the first purge three-way valve 15 is located, the remote-controlled air source control valve 22 is opened, and the purge three-position two-way valve 13 and the first purge three-way valve 15 are opened to keep the second back-blow circuit unobstructed, and the first back-blow circuit where the second sampling three-way valve 11 and the third sampling three-way valve 12 are located is closed by the remote control, and at the same time, the remote-controlled exhaust three-way valve 14 is connected to the circuit side and emptied, isolating and disconnecting the connection with the second purge three-way valve 16.

[0050] While ensuring normal operation, when purging the second back-blowing circuit side where the second purge three-way valve 16 is located, the remote-controlled air source control valve 22 opens the purge three-position two-way valve 13 and connects it to the second purge three-way valve 16, and the remote-controlled second sampling three-way valve 11 and the third sampling three-way valve 12 are disconnected from the circuit connection side. At the same time, the remote-controlled exhaust three-way valve 14 is connected to the circuit side and emptied, isolating and disconnecting it from the first purge three-way valve 15.

[0051] In the specific implementation, under the measurement and back-blowing pressure test state, the two-position three-way valve 3 realizes communication with the second pressure transmitter 8 on both sides of the gas circuit. During the back-blowing pressure test, the back-blowing gas is blown into the second pressure transmitter 8 in the reverse direction through the sampling circuit. The second pressure transmitter 8 detects the air pressure value, and the pressure value is transmitted to the remote controller. The remote controller determines the state of the pipeline by receiving the value. If it exceeds the set value, it is preliminarily determined that the air tightness of the pipeline is abnormal, and then enters the secondary air tightness judgment. The remote controller stops the back-blowing pressure test mode and enters the measurement state again. At this time, the air source control valve 22 is closed, and the two-position three-way valve 3 controls the connection of the check valve 18. At this time, the standard gas source 9 enters the sampling circuit through the check valve 18. Under normal sampling conditions, if the sampling circuit is airtight, the standard gas will be sampled from the sampling pipeline to the analyzer 4, and the analyzer 4 will also correctly display the component content of the standard gas source 9. If the value detected by the analyzer 4 does not correspond to the content value of the standard gas source 9 within the set sampling comparison monitoring time range, it is determined that the air tightness of the sampling pipeline is abnormal. The use of the sampling pipeline air tightness secondary discrimination system can also be used as a means of monitoring the measurement accuracy of the analyzer 4 itself, and the accuracy of the analyzer 4 can be judged by comparing the displayed values.

[0052] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be modified and varied in various ways. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A sampling pipeline tightness monitoring device, characterized in that: The invention comprises a backflush device, a sampling probe (1), a first sampling three-way valve (2), a two-position three-way valve (3), a remote controller and an analyzer (4); the sample outlet end of the sampling probe (1) is connected to the two-position three-way valve (3), the first sampling three-way valve (2) and the analyzer (4) in sequence through a pipeline to form a first sampling circuit; a second sampling circuit is provided in parallel on the connecting pipeline between the first sampling three-way valve (2) and the two-position three-way valve (3); The back-blowing device comprises a back-blowing gas source (5), a filter pressure reducer (6) and a first pressure transmitter (7); the back-blowing gas source (5) is connected to the first sampling circuit through the filter pressure reducer (6) and the first pressure transmitter (7) in sequence; the first pressure transmitter (7) is connected to the first sampling three-way valve (2) through a pipeline; The remote controller is electrically connected to the analyzer (4), the first pressure transmitter (7), the first sampling three-way valve (2), and the two-position three-way valve (3) respectively.

2. A sampling pipeline tightness monitoring device according to claim 1, characterized in that: A second pressure transmitter (8) and a standard gas source (9) are provided at one end of the first sampling circuit close to the sampling probe (1); the second pressure transmitter (8) and the standard gas source (9) are connected to the pipeline of the first sampling circuit through the two-position three-way valve (3); a first two-way valve (10) is provided between the two-position three-way valve (3) and the sampling probe (1); The second pressure transmitter (8) and the first two-way valve (10) are electrically connected to the remote controller respectively.

3. A sampling pipeline tightness monitoring device according to claim 1, characterized in that: The two ends of the second sampling loop are connected to the pipeline of the first sampling loop through a second sampling three-way valve (11) and a third sampling three-way valve (12), respectively; the second sampling three-way valve (11) is connected to the pipeline close to the analyzer (4); the second sampling three-way valve (11) and the third sampling three-way valve (12) are electrically connected to the remote controller, respectively.

4. A sampling pipeline tightness monitoring device according to claim 2, characterized in that: A first back-blow circuit is formed between the first sampling three-way valve (2) and the first pressure transmitter (7), and a three-position two-way purge valve (13) is arranged on the first back-blow circuit. The back-blow gas source (5) is connected to the middle section of the first sampling circuit through the three-position two-way purge valve (13) to form a second back-blow circuit. The back-blow gas source (5) is connected to the middle section of the second sampling circuit through the three-position two-way purge valve (13) to form a third back-blow circuit. The three-position two-way purge valve (13) is electrically connected to the remote controller.

5. A sampling pipeline tightness monitoring device according to claim 1, characterized in that: The first sampling circuit and the second sampling circuit are connected in parallel to an exhaust three-way valve (14) for reducing the pressure of the pipeline.

6. A sampling pipeline tightness monitoring device according to claim 4, characterized in that: The second backflush circuit is connected to the first sampling circuit through a first purge three-way valve (15), and the third backflush circuit is connected to the second sampling circuit through a second purge three-way valve (16). The first purge three-way valve (15) and the second purge three-way valve (16) are electrically connected to the remote controller respectively.

7. A sampling pipeline tightness monitoring device according to claim 2, characterized in that: A second two-way valve (17) is provided on the pipeline between the first sampling three-way valve (2) and the analyzer (4), and a check valve (18) is provided between the standard gas source (9) and the two-position three-way valve (3).

8. A sampling pipeline tightness monitoring device according to claim 1, characterized in that: The back-blowing gas source (5) comprises a first back-blowing gas source (19) and a second back-blowing gas source (20); the junction of the first back-blowing gas source (19) and the second back-blowing gas source (20) is connected to the filter pressure reducer (6) via a remote-controlled three-way valve (21); an air source control valve (22) is provided on the pipeline between the remote-controlled three-way valve (21) and the filter pressure reducer (6); the remote-controlled three-way valve (21) and the air source control valve (22) are respectively electrically connected to the remote controller.

9. A sampling pipeline tightness monitoring device according to claim 1, characterized in that: The remote controller is also connected to an alarm unit, and the alarm unit is electrically connected to the controller.

10. An analyzer (4), characterized in that: The invention comprises the sampling pipeline tightness monitoring device as described in any one of claims 1 to 9.

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