CN112051231B - A method and device for preventing water from entering into a cavity ring-down closed-circuit flux analyzer - Google Patents

Abstract

The invention discloses a method and a device for preventing water from entering a cavity ring-down closed-circuit flux analyzer, and relates to the field of cavity ring-down closed-circuit flux analysis. The method comprises a cabinet and a support frame, wherein the support frame is located at one side of the cabinet, a high vacuum air pump and an auxiliary pump are respectively installed at the lower part of the cabinet, a power strip is arranged on the top of the high vacuum air pump and the auxiliary pump, and a gas concentration analyzer is installed on the top of the power strip. The device adopts a double-pump air intake structure and high-speed sampling to reduce high-frequency attenuation caused by long gas path sampling. A special rainproof and mosquito-proof air intake port can prevent detection interference. Automatically controlled gas path purge can respond at the millisecond level, and water inflow caused by wave impact can be prevented in marine applications. The device has a sample gas drying efficiency of more than 90%, and high-frequency water vapor pulsation suppression of more than 95%, which effectively reduces the crosstalk of water vapor on absorption spectra of other trace gases. Timed multiple high-pressure zero gas pulses can accurately measure gas path delay, thereby improving the accuracy of detection results.

Description

A method and device for preventing water from entering into a cavity ring-down closed-circuit flux analyzer

Technical Field

The invention relates to the technical field of cavity ring-down closed-circuit flux analysis, and in particular to a method and a device for preventing water from entering a cavity ring-down closed-circuit flux analyzer.

Background Art

Eddy covariance measurements of oceanic greenhouse gas fluxes such as CO ₂ and CH ₄ are an effective tool for the development and validation of ocean-air exchange models and for the study of the ocean carbon cycle. Results from more than a decade of published papers have demonstrated the main interferences of water vapor and motion and revealed experimental methods to improve the precision and accuracy of measurements. Water vapor cross-sensitivity is the largest source of error in measuring CO 2 flux using infrared gas analyzers (IRGAs), often resulting in a tenfold deviation in the measured CO 2 flux. As previously assumed, most of the error is not related to optical contamination. Although various correction schemes have been demonstrated, the use of an air dryer and a closed-circuit gas analyzer is the most effective method to eliminate this interference. This approach also avoids the density correction described by Webb et al. (Webb et al. 1980). For a cavity ring-down analyzer (CRDS) and an air dryer through a 60 m inlet duct, the flux correction showed a reduction of <5%. When sampling moist air, the flux detection limit estimated by the CRDS analyzer plus air dryer system is ten times better than that of the IRGA. There are published protocols for drying the closed-circuit flux system of IRGAs. However, the special air pressure control design of the CRDS analyzer, and its drying scheme must be different from the air intake design of the IRGAs system, which has not been published.

For the existing cavity ring-down closed-circuit flux analyzers, signal lag and frequency response are common problems in all closed-circuit flux systems. Especially when the gas path structure is complex, how to accurately measure the signal lag time and frequency decay time is very complicated. In addition, the closed-circuit gas analyzer draws gas into the analyzer for measurement. When used in the ocean, it is very likely to be affected by waves and heavy rains, causing water to enter the gas path. In severe cases, if water enters the optical cavity, the gas analyzer will be damaged.

Summary of the invention

The purpose of the present invention is to provide a method and device for preventing water from entering a cavity ring-down closed-circuit flux analyzer, so as to solve the problem proposed in the above background technology that accurately measuring signal lag time and frequency decay time and water ingress into the analyzer may cause damage to the gas analyzer.

To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a device for preventing water from entering an optical cavity ring-down closed-circuit flux analyzer, comprising a cabinet, a zero-gas high-pressure gas tank, an air compressor and a support frame, a first bracket and a second bracket are respectively installed on one side of the support frame, a solenoid valve 1 is installed on the second bracket, and the solenoid valve 1 is connected to the zero-gas high-pressure gas tank through an outlet pipe, a high-pressure and low-pressure gauge and a flow meter 1 are respectively installed on the outlet pipe, an air inlet pipe is installed on the first bracket, one end of the air inlet pipe is connected to one end of a stainless steel pipe through a three-way valve, and the other end is connected to the solenoid valve 2 and a large flow meter. A three-way valve is provided between the filters, the other end of the stainless steel pipe is connected to the air inlet, and an O-ring is sleeved at the connection. An air compressor is installed on one side of the cabinet through a connecting pipe, a high-vacuum air pump and an auxiliary pump are installed at the lower part of the cabinet, power strips are arranged on the top of the high-vacuum air pump and the auxiliary pump, a gas concentration analyzer is installed on the top of the power strip, a display, an AC-DC charging controller, a control unit, a large-flow filter and a water detector are installed inside the cabinet, an air dryer is installed at the bottom of the display, and a solenoid valve group is installed on one side of the display.

Preferably, the air inlet comprises a 3D printed structure, a filter, a filter bracket, fastening screws and an O-ring, a filter bracket is arranged inside the 3D printed structure, a filter is arranged at the bottom of the filter bracket, and the bottom of the stainless steel tube is fixed to the 3D printed structure by fastening screws.

Preferably, the solenoid valve group is composed of four solenoid valves, namely solenoid valve 2, solenoid valve 3, solenoid valve 4 and solenoid valve 5, and the solenoid valve 2 is connected to the air compressor.

Preferably, the inner diameter of the stainless steel tube is 9 mm.

Preferably, the inner diameter of the air inlet pipe and the air outlet pipe is 9 mm.

Preferably, the control unit is electrically connected to the display, the AC-DC charging controller, the solenoid valve 1, the solenoid valve group, the large flow filter, the water detector, the high vacuum air pump and the auxiliary pump and the gas concentration analyzer respectively.

Preferably, the length of the pipeline between the solenoid valve 1 and the three-way valve is equal to the length of the pipeline from the air inlet to the three-way valve.

Preferably, a manual valve is provided between the gas concentration analyzer and the high vacuum air pump, and the manual valve is in a normally closed state, and its function is to balance the air pressure. When the system is powered off, the space between the gas concentration analyzer and the high vacuum air pump is in a vacuum state. If the air pressure is not balanced, the water vapor inside the air dryer will continuously penetrate into the vacuum pipeline, causing water accumulation inside the high vacuum air pump.

Preferably,

Step 1: Control the switching action of the solenoid valve group and the solenoid valve 1 through the control unit. The solenoid valve 1 is a straight-through solenoid valve in a normally closed state, serving the pulse delay measurement. One end of the solenoid valve is connected to the opened zero gas high-pressure gas tank through the outlet pipe. The gas pressure of the zero gas high-pressure gas tank is 10MPa. The gas pressure is adjusted to 0.05MPa and the flow rate is adjusted to 3.5SLPM through the high and low pressure gauges. The other end of the solenoid valve 1 is connected to the three-way valve. The distance from the solenoid valve 1 to the three-way valve is equal to the distance from the air inlet to the three-way valve. In this way, the time when the high-pressure zero gas arrives at the gas concentration analyzer is consistent with the time when the gas to be measured enters the gas concentration analyzer from the air inlet. During the use of the entire device, there will be factors that affect the gas path delay, such as gas path aging and filter membrane clogging. Therefore, it is necessary to regularly measure the delay time. The control unit will release 9 zero gas pulses continuously at intervals of 10s in the early morning of each day. On the ocean, the background CO ₂ When the concentration is about 400ppm and the zero gas pulse enters the gas concentration analyzer, the gas concentration analyzer will observe obvious concentration fluctuations. By analyzing the relationship between the pulse emission time and the detected pulse fluctuations, the gas path delay can be calculated. The control unit supports manual control of the zero gas pulse through the manual gear and manual observation of the gas path delay time, which is convenient for initial equipment performance testing;

Step 2, solenoid valve 2 and solenoid valve 3 are straight-through solenoid valves, solenoid valve 2 is in the normally closed state, solenoid valve 3 is in the normally open state, solenoid valve 4 and solenoid valve 5 are three-way solenoid valves, all in the normally open state. The solenoid valve group composed of these four solenoid valves serves to prevent water from entering the gas path. When the water detector detects water entering the gas path, it feeds back to the control unit, and the control unit responds at a speed of 100ms and switches the working states of the four solenoid valves at the same time. Solenoid valve 2 opens, solenoid valve 3 closes, and the working gas paths of solenoid valves 4 and 5 are switched from the air inlet to the outlet inside the cabinet. The air intake is prevented from being damaged by the internal gas circuit equipment. The large flow filter at the front end of the solenoid valve 3 filters the incoming gas and prevents water from entering the solenoid valve 3. After the solenoid valve 2 is opened, the 0.7MPa high-pressure airflow of the air compressor will instantly blow the water in the gas circuit out of the air inlet. At the same time, in order to avoid high-frequency repeated switching of the solenoid valve for water inlet backblowing, the control unit will allow each purge process to last for 5 minutes. If there is no water in the gas circuit in the subsequent detection, the gas circuit will automatically switch back to the initial state. If there is still water in the gas circuit, continue to purge to ensure the stability and sustainability of the system.

Step 3: When the air intake pipeline of the closed-loop flux is long, and the pressure control technology of the gas concentration analyzer has great restrictions on the air path speed of the high-vacuum air pump, it will cause a large pipeline delay and may even change the physical structure of the turbulent flow. In order to ensure that the atmosphere enters the gas concentration analyzer in the form of turbulence, the Reynolds number of the air flow in the pipeline must be >2000. Therefore, an auxiliary pump is needed to quickly draw the air flow from the air inlet and then pump it into the gas concentration analyzer. The auxiliary pump has a pumping speed of 20SLPM. For a pipeline with an inner diameter of 9mm, the corresponding Reynolds number is 2800 when the ambient temperature is 26℃, that is, the turbulent properties of the atmosphere are retained inside the air path. The gas concentration analyzer only needs an air flow of about 5SLPM, and the excess 15SLPM of air flow is discharged through a manual valve, and its discharge flow is controlled by flowmeter 2;

Step 4: Before the airflow enters the gas concentration analyzer, it first passes through an air dryer to dry the gas to be measured. After passing through the gas concentration analyzer, the airflow is introduced into the outer tube of the air dryer by the reflux method. The air pressure ratio before entering the gas concentration analyzer and after leaving the gas concentration analyzer is about 5:1. It is then discharged into the atmosphere through a high vacuum air pump. After the above steps, water can be prevented from entering the measuring pipeline and thus damaging the equipment, while the relevant data can be accurately measured.

Compared with the prior art, the present invention has the following beneficial effects:

1. In the present invention, the air intake pipeline of the closed-loop flux is relatively long, and the pressure control technology of the gas concentration analyzer has great restrictions on the air path speed of the high-vacuum air pump, which will cause a large pipeline delay and may even change the physical structure of the turbulent flow. In order to ensure that the atmosphere enters the gas concentration analyzer in the form of turbulence, it is necessary to ensure that the Reynolds number of the airflow in the pipeline is >2000. Therefore, it is necessary to add an auxiliary pump to quickly draw the airflow from the air inlet and then pump it into the gas concentration analyzer. The auxiliary pump has a pumping speed of 20SLPM. For a pipeline with an inner diameter of 9mm, the corresponding Reynolds number is 2800 when the ambient temperature is 26°C, that is, the turbulent properties of the atmosphere are retained inside the air path. The gas concentration analyzer only needs an airflow of about 5SLPM, and the excess 15SLPM of airflow is discharged through a manual valve, and its discharged flow is controlled by flowmeter 2. For the dual-pump air intake structure of the cavity ring-down closed-loop gas analyzer, high-speed sampling is used to reduce the high-frequency attenuation caused by long air path sampling;

2. The present invention sets a water detector and an air compressor. When the water detector detects water entering the air path, it feeds back to the control unit. The control unit responds at a speed of 100ms and switches the working state of the four solenoid valves at the same time. The solenoid valve 2 is opened, the solenoid valve 3 is closed, and the working air paths of the solenoid valves 4 and 5 are switched from the air inlet to the air intake from the inside of the cabinet to prevent the internal air path equipment from being damaged. The large flow filter at the front end of the solenoid valve 3 filters the incoming gas and prevents water from entering the solenoid valve 3. After the solenoid valve 2 is opened, the 0.7M The Pa high-pressure airflow will instantly blow the water in the gas circuit out of the air inlet. At the same time, in order to avoid high-frequency repeated opening and closing of the solenoid valve for water back-blowing, the control unit will allow each purge process to last for 5 minutes. If there is no water in the gas circuit in the subsequent detection, the gas circuit will automatically switch back to the initial state. If there is still water in the gas circuit, the purge will continue to ensure the stability and sustainability of the system; the special rain-proof and mosquito-proof air inlet can prevent detection interference, and the water detector set up has a millisecond response, which can automatically control the gas circuit purge, which can prevent water from entering the gas circuit caused by waves in marine applications;

3. The present invention arranges an air dryer at the front section of the gas concentration analyzer. Before the airflow enters the gas concentration analyzer, it first passes through the air dryer to dry the gas to be tested. After passing through the gas concentration analyzer, the airflow is introduced into the outer tube of the air dryer by the reflux method. The air pressure ratio before entering the gas concentration analyzer and after exiting the gas concentration analyzer is about 5:1. The airflow is then discharged to the atmosphere through a high vacuum air pump. In this way, the airflow in the outer tube used for drying is 5 times the speed of the humid airflow in the inner tube. The dehumidification effect achieved in actual measurement is comparable to the effect of backwashing with 2 to 3 times the speed of dry air with a dew point of -40°C. The sample gas drying efficiency is >90%, and the high-frequency water vapor pulsation suppression is >95%, which effectively reduces the crosstalk of water vapor on the absorption spectra of other trace gases. When the ambient dew point is about 20°C, the dew point after drying is less than -15°C. At this dryness level, the spectral crosstalk effect and concentration effect of water vapor on trace gases such as _CO2 can be ignored.

4. The gas circuit delay can be measured by timing the release of multiple high-pressure zero-gas pulses, thereby more accurately compensating the test data, and supporting manual release.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic diagram of the structural principle of the present invention;

Fig. 2 is a schematic diagram of the structure of the present invention;

FIG3 is a schematic diagram of the cross-sectional structure of the present invention;

FIG4 is a schematic diagram of the air inlet structure of the present invention;

FIG. 5 is a schematic diagram of the cross-sectional structure of the air inlet of the present invention.

In the figure: 1. Cabinet; 2. Zero gas high-pressure gas tank; 3. Air compressor; 4. High and low pressure gauges; 5. Support frame; 6. Solenoid valve 1; 7. First bracket; 8. Second bracket; 9. Connecting pipe; 10. Display; 11. High vacuum air pump; 12. Socket; 13. Gas concentration analyzer; 14. Auxiliary pump; 15. Flow meter 1; 16. Three-way valve; 17. AC-DC charging controller; 18. Control unit; 19. Air dryer; 20. Solenoid valve group; 21. High flow filter; 22. Water detector; 23. Air inlet; 24. Fastening screws; 25. O-ring; 26. Stainless steel pipe; 27. Filter; 28. Filter bracket; 29. 3D printing structure; 30. Inlet pipe; 31. Outlet pipe.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

In the present invention, unless otherwise clearly stipulated and limited, the terms "set", "install", "connected", "connect", "fixed", "socketed", and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

Please refer to Figures 1-5. The present invention provides a technical solution: a device for preventing water from entering an optical cavity ring-down closed-circuit flux analyzer, comprising a cabinet 1, a zero gas high-pressure gas tank 2, an air compressor 3 and a support frame 5, one side of the support frame 5 is respectively installed with a first bracket 7 and a second bracket 8, the second bracket 8 is installed with an electromagnetic valve 6, and the electromagnetic valve 6 is connected to the zero gas high-pressure gas tank 2 through an outlet pipe 31, the outlet pipe 31 is respectively installed with a high and low pressure gauge 4 and a flow meter 15, the first bracket 7 is installed with an air inlet pipe 30, one end of the air inlet pipe 30 is connected to one end of a stainless steel pipe 26 through a three-way valve 16, and the other end is connected to a three-way valve between the electromagnetic valve 2 and the large flow filter. Valve, the other end of the stainless steel pipe 26 is connected to the air inlet 23, and an O-ring 25 is sleeved at the connection. An air compressor 3 is installed on one side of the cabinet 1 through a connecting pipe 9. A high vacuum air pump 11 and an auxiliary pump 14 are respectively installed at the lower part of the cabinet 1. A power strip 12 is arranged on the top of the high vacuum air pump 11 and the auxiliary pump 14. A gas concentration analyzer 13 is installed on the top of the power strip 12. A display 10, an AC-DC charging controller 17, a control unit 18, a large flow filter 21 and a water detector 22 are respectively installed inside the cabinet 1. An air dryer 19 is installed at the bottom of the display 10, and a solenoid valve group 20 is installed on one side of the display 10.

Further, please refer to Figures 1-5, the air inlet 23 includes a 3D printed structure 29, a filter 27, a filter bracket 28, a fastening screw 24 and an O-ring 25. The filter bracket 28 is arranged inside the 3D printed structure 29, and the filter 27 is arranged at the bottom of the filter bracket 28. The bottom of the stainless steel tube 26 is fixed to the 3D printed structure 29 by the fastening screw 24. The special rainproof and mosquito-proof air inlet can prevent excessive impurities from entering.

Further, please refer to Figures 1 and 3. The solenoid valve group 20 is composed of four solenoid valves, namely solenoid valve 2, solenoid valve 3, solenoid valve 4, and solenoid valve 5. Through multiple solenoid valves, the backblowing of the control gas path and the switching of the gas path to the analyzer are controlled.

Further, referring to FIG. 1-5 , the solenoid valve 2 is connected to the air compressor 3 , the inner diameter of the stainless steel pipe 26 is 9 mm, and the inner diameters of the air inlet pipe 30 and the air outlet pipe 31 are 9 mm.

Further, referring to Figures 1-5, the control unit 18 is electrically connected to the display 10, the AC-DC charging controller 17, the solenoid valve 6, the solenoid valve group 20, the large flow filter 21, the water detector 22, the high vacuum air pump 11 and the auxiliary pump 14 and the gas concentration analyzer 13 respectively. Furthermore, the pipeline length between the solenoid valve 6 and the three-way valve 16 is equal to the pipeline length from the air inlet 23 to the three-way valve 16, and the time when the high-pressure zero gas arrives at the analyzer is consistent with the time when the atmosphere arrives at the analyzer.

Further, referring to FIG1 , a manual valve is provided between the gas concentration analyzer 13 and the high vacuum air pump 11. The manual valve is in a normally closed state and its function is to balance the air pressure. When the system is powered off, the space between the gas concentration analyzer 13 and the high vacuum air pump 11 is in a vacuum state. If the air pressure is not balanced, the water vapor inside the air dryer 19 will continuously penetrate into the vacuum pipeline, causing water accumulation inside the high vacuum air pump 11.

Working principle:

Step 1, control the solenoid valve group 20 and the solenoid valve 6 on and off through the control unit 18. The solenoid valve 6 is a straight-through solenoid valve in a normally closed state, serving the pulse delay measurement. One end of the solenoid valve is connected to the opened zero gas high-pressure gas tank 2 through the outlet pipe 31. The gas pressure of the zero gas high-pressure gas tank 2 is 10MPa. The gas pressure is adjusted to 0.05MPa and the flow rate is adjusted to 3.5SLPM through the high and low pressure gauge 4. The other end of the solenoid valve 6 is connected to the three-way valve 16. The distance from the solenoid valve 6 to the three-way valve 16 is equal to the distance from the air inlet 23 to the three-way valve 16. In this way, the time when the high-pressure zero gas arrives at the gas concentration analyzer 13 is consistent with the time when the gas to be measured enters the gas concentration analyzer 13 from the air inlet 23. During the use of the entire device, there will be factors that affect the gas path delay, such as gas path aging and filter membrane clogging. Therefore, it is necessary to regularly measure the delay time. The control unit 18 will release 9 zero gas pulses continuously at intervals of 10s in the early morning of each day. On the ocean, the background CO ₂ When the concentration is about 400ppm and the zero gas pulse enters the gas concentration analyzer 13, the gas concentration analyzer 13 will observe obvious concentration fluctuations. By analyzing the relationship between the pulse emission time and the detected pulse fluctuations, the gas path delay can be calculated. The control unit 18 supports manual control of the zero gas pulse and manual observation of the gas path delay time, which is convenient for initial equipment performance testing;

Step 2, solenoid valve 2 and solenoid valve 3 are straight-through solenoid valves, solenoid valve 2 is in a normally closed state, solenoid valve 3 is in a normally open state, solenoid valve 4 and solenoid valve 5 are three-way solenoid valves, all in a normally open state, and the solenoid valve group 20 composed of these four solenoid valves is used to prevent water from entering the gas path. When the water detector 22 detects water entering the gas path, it feeds back to the control unit 18, and the control unit 18 responds at a speed of 100ms and switches the working states of the four solenoid valves at the same time, solenoid valve 2 is opened, solenoid valve 3 is closed, and the working gas paths of solenoid valves 4 and 5 are switched from the air inlet 23 to the cabinet Air is taken in from the body 1 to prevent the internal gas circuit equipment from being damaged. The large flow filter 21 at the front end of the solenoid valve 3 filters the incoming gas and prevents water from entering the solenoid valve 3. After the solenoid valve 2 is opened, the 0.7MPa high-pressure airflow of the air compressor will instantly blow the water in the gas circuit out of the air inlet 23. At the same time, in order to avoid high-frequency repeated switching of the solenoid valve for water backwashing, the control unit 18 will allow each purging process to last for 5 minutes. If there is no water in the gas circuit in the subsequent detection, the gas circuit will automatically switch back to the initial state. If there is still water in the gas circuit, continue to purge to ensure the stability and sustainability of the system.

Step 3, when the air intake pipeline of the closed-loop flux is long, and the pressure control technology of the gas concentration analyzer has great restrictions on the air path speed of the high-vacuum air pump, it will cause a large pipeline delay and may even change the physical structure of the turbulent flow. In order to ensure that the atmosphere enters the gas concentration analyzer 13 in the form of turbulence, it is necessary to ensure that the Reynolds number of the air flow in the pipeline is greater than 2000. Therefore, it is necessary to add an auxiliary pump 14 to quickly draw the air flow from the air inlet and then pump air to the gas concentration analyzer 13. The auxiliary pump 14 has a pumping speed of 20SLPM. For a pipeline with an inner diameter of 9mm, the corresponding Reynolds number is 2800 when the ambient temperature is 26°C, that is, the turbulent properties of the atmosphere are retained inside the air path. The gas concentration analyzer 13 only needs an airflow of about 5SLPM, and the excess 15SLPM of airflow is discharged through a manual valve, and its discharge flow is controlled by flowmeter 2;

Step 4, before the airflow enters the gas concentration analyzer 13, it first passes through an air dryer to dry the gas to be measured. After passing through the gas concentration analyzer 13, the airflow is introduced into the outer tube of the air dryer by the reflux method, and is discharged into the atmosphere through a high vacuum air pump. The air pressure ratio before entering the gas concentration analyzer and after leaving the gas concentration analyzer is about 5:1. After the above steps, water can be prevented from entering the measuring pipeline to damage the equipment, and at the same time, relevant data can be accurately measured.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims (6)

1. The utility model provides a device that prevents optical cavity ring down closed-circuit flux analyzer intaking which characterized in that: including cabinet body (1), zero gas high pressure gas tank (2), air compressor machine (3) and support frame (5), first support (7) and second support (8) are installed respectively to one side of support frame (5), install solenoid valve one (6) on second support (8), just solenoid valve one (6) are connected with zero gas high pressure gas tank (2) through outlet duct (31), install high-low pressure gauge (4) and flowmeter one (15) respectively on outlet duct (31), install intake pipe (30) on first support (7), intake pipe (30) one end is connected with stainless steel pipe (26) one end through three-way valve (16), and the other end is connected to the three-way valve between solenoid valve two and the large-traffic filter, stainless steel pipe (26) other end is connected with air inlet (23), and junction cup joints O type circle (25), high-pressure gauge (11) and high-pressure pump (14) are installed respectively to one side of the air pump body (1) through outlet duct (9), auxiliary pump (12) are installed at the inside below of air pump body (1), auxiliary pump (14) are installed at top analysis top (12), the intelligent cabinet temperature control device is characterized in that a display (10), an alternating-current-direct-current charging controller (17), a control unit (18), a high-flow filter (21) and a water detector (22) are respectively arranged in the cabinet body (1), an air dryer (19) is arranged at the bottom of the display (10), and an electromagnetic valve group (20) is arranged at one side of the display (10);

the electromagnetic valve group (20) consists of 4 electromagnetic valves, namely an electromagnetic valve II, an electromagnetic valve III, an electromagnetic valve IV and an electromagnetic valve V, wherein the electromagnetic valve II is connected with the air compressor (3);

The length of a pipeline between the solenoid valve I (6) and the three-way valve (16) is equal to the length of a pipeline from the air inlet (23) to the three-way valve (16);

A manual control valve is arranged between the gas concentration analyzer (13) and the high-vacuum air pump (11), and is in a normally closed state and has the function of balancing air pressure; when the system is powered off, the space between the gas concentration analyzer (13) and the high-vacuum air pump (11) is in a vacuum state, and if the air pressure balance is not performed, water vapor in the air dryer (19) can continuously permeate into a vacuum pipeline, so that water is accumulated in the high-vacuum air pump (11).

2. The apparatus for preventing cavity ring down closed-loop flux analyzer from water inflow as defined in claim 1, wherein: the air inlet (23) comprises a 3D printing structure (29), a filter screen (27), a filter screen support (28), a fastening screw (24) and an O-shaped ring (25), wherein the filter screen support (28) is arranged in the 3D printing structure (29), the filter screen (27) is arranged at the bottom of the filter screen support (28), and the bottom of the stainless steel tube (26) is fixed with the 3D printing structure (29) through the fastening screw (24).

3. The apparatus for preventing cavity ring down closed-loop flux analyzer from water inflow as defined in claim 1, wherein: the inner diameter of the stainless steel tube (26) is 9mm.

4. The apparatus for preventing cavity ring down closed-loop flux analyzer from water inflow as defined in claim 1, wherein: the inner diameters of the air inlet pipe (30) and the air outlet pipe (31) are 9mm.

5. The apparatus for preventing cavity ring down closed-loop flux analyzer from water inflow as defined in claim 1, wherein: the control unit (18) is respectively and electrically connected with the display (10), the alternating-current-direct-current charging controller (17), the electromagnetic valve I (6), the electromagnetic valve group (20), the large-flow filter (21), the water detector (22), the high-vacuum air pump (11), the auxiliary pump (14) and the gas concentration analyzer (13).

6. The apparatus for preventing cavity ring down from entering water of closed-circuit flux analyzer as defined in claim 1, wherein the measuring method is characterized by:

Step 1, control the switch action of the electromagnetic valve group (20) and the electromagnetic valve I (6) through the control unit (18), the electromagnetic valve I (6) is a straight-through electromagnetic valve, in a normally closed state, and is used for pulse delay measurement, one end of the electromagnetic valve I is communicated with an opened zero-gas high-pressure gas tank (2) through a gas outlet pipe (31), the gas pressure of the zero-gas high-pressure gas tank (2) is 10MPa, the gas pressure is regulated to 0.05MPa through a high-low pressure meter (4), the flow rate is regulated to 3.5SLPM, the other end of the electromagnetic valve I (6) is connected to a three-way valve (16), the distance from the electromagnetic valve I (6) to the three-way valve (16) is equal to the distance from a gas inlet (23) to the three-way valve (16), so that the time of the high-pressure zero gas reaches a gas concentration analyzer (13) is consistent with the time of the gas to be measured entering the gas concentration analyzer (13) through the gas inlet (23), the factors of gas channel aging and gas channel delay influence by the filter membrane blocking in the gas channel in the using process of the whole device can exist, the control unit (18) can continuously release 9 zero-gas pulses at a time interval of 10 seconds each day, on the morning, the zero-pulses are ₂ ppm, the gas concentration is obviously controlled by the pulse analyzer, the time of the artificial pulse analyzer can reach the time of the pulse analyzer, the artificial pulse analyzer can be controlled, and the time of the pulse analyzer is calculated, and the time of the artificial pulse analyzer is controlled to reach the time of the pulse analyzer, and the time of the pulse analyzer is controlled, and the time of the artificial pulse analyzer is calculated, the performance detection of the initial equipment is convenient;

Step 2, the electromagnetic valve II and the electromagnetic valve III are through electromagnetic valves, the electromagnetic valve II is in a normally closed state, the electromagnetic valve III is in a normally open state, the electromagnetic valve IV is a three-way electromagnetic valve, all the electromagnetic valves 20 formed by the 4 electromagnetic valves are in a normally open state, all the electromagnetic valves are used for preventing water from entering a gas path, after a water detector 22 detects water entering the gas path, the water is fed back to a control unit 18, the control unit 18 responds at a speed of 100ms, the working states of the 4 electromagnetic valves are switched, the electromagnetic valve II is opened, the electromagnetic valve III is closed, the working gas paths of the electromagnetic valve IV and the electromagnetic valve V are switched from a gas inlet 23 to gas entering from the inside of a cabinet body 1, the internal gas path equipment is prevented from being damaged, a large-flow filter 21 at the front end of the electromagnetic valve III filters the entering gas path, water can be prevented from entering the electromagnetic valve III, after the electromagnetic valve II is opened, the high-pressure air flow of 0.7MPa in the air compressor can blow water in the gas path out of the gas inlet 23 instantaneously, and simultaneously, in order to avoid the high-frequency repeated switching electromagnetic valves to blow back water, the control unit 18 can let the water inlet process continuously process for 5 minutes each time, if the gas path is automatically detected, and if the system is continuously purged after the gas path is continuously switched, the system is continuously purged, and the system is still stable;

Step 3, when the closed-circuit flux air inlet pipeline is longer, and the pressure control technology of the gas concentration analyzer has great limitation on the air path speed of the high-vacuum air pump, larger pipeline delay is caused, even the physical structure of turbulence is possibly changed, in order to ensure that the atmosphere enters the gas concentration analyzer (13) in a turbulent mode, the Reynolds number of the air flow in the pipeline is required to be ensured to be more than 2000, therefore, an auxiliary pump (14) is required to be added for rapidly pumping the air flow from the air inlet and then pumping the air flow into the gas concentration analyzer (13), the pumping speed of the auxiliary pump (14) is 20SLPM, for the pipeline with the inner diameter of 9mm, the corresponding Reynolds number is 2800 when the ambient air temperature is 26 ℃, namely the turbulence attribute of the atmosphere is reserved in the air path, the gas concentration analyzer (13) only needs about 5SLPM, and the redundant 15SLPM air flow is discharged through a manual valve and the flow discharged through a flowmeter II is controlled;

Step 4, drying the gas to be measured by an air dryer (19) before the gas flow enters the gas concentration analyzer (13), introducing the gas flow into an outer tube of the air dryer (19) by a reflux method after the gas flow passes through the gas concentration analyzer (13), and enabling the ratio of the gas pressure before the gas flow enters the gas concentration analyzer (13) to the gas pressure after the gas flow enters the gas concentration analyzer (13) to be about 5:1, then the water is discharged to the atmosphere through a high vacuum air pump (11), and after the steps, the water entering a measuring pipeline can be prevented from damaging equipment, and meanwhile, related data can be accurately measured.