Negative pressure tracer generator and method

Abstract

The invention relates to a negative pressure tracer generator and method, and the negative pressure box is in a rectangular box shape, forms negative pressure in the negative pressure box, and comprises a gas inlet and a gas outlet; the tracer agent generating gas circuit is provided with a tracer agent assembly, and the tracer agent assembly is used for enabling the first gas entering the gas inlet to form target tracer agent gas and transmitting the target tracer agent gas to the gas outlet; the negative pressure generation gas circuit forms negative pressure in the negative pressure box body, a negative pressure generator is arranged on the negative pressure generation gas circuit, and the negative pressure generator is used for sucking gas in the negative pressure box body into the negative pressure generation gas circuit; and the purifier is connected with the negative pressure generator and is used for preventing the target tracer gas in the negative pressure box body from being transmitted to the gas outlet. According to the invention, the technical problem that part of radioactive aerosol or reagent gas enters the external environment and the safety of personnel in the surrounding environment is affected due to the fact that the pipeline is in direct contact with the working environment and part of the pipeline may leak or loosen in the use process is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear facilities, and in particular to a negative pressure tracer generator and method. Background Art

[0002] In the current nuclear industry, including nuclear power plants, nuclear test reactors, reprocessing plants and nuclear facilities in many scientific research institutes, ventilation and purification systems for treating radioactive aerosols and airborne radioactive iodine are installed to prevent radioactive nuclides from entering the atmospheric environment, thereby ensuring the safety of the working environment of staff and the living environment of the surrounding people.

[0003] In order to ensure the effective operation of the ventilation and purification system of nuclear facilities, it is essential to perform leak detection tests on the high-efficiency filter rows and iodine adsorber rows of the ventilation system in accordance with the standard EJ / T 791-2014 "On-site Inspection of Nuclear Air Purification Systems". This can evaluate whether the purification performance of the high-efficiency filter and iodine adsorber purification units of each ventilation and purification system meets the acceptance standards and nuclear safety operation requirements.

[0004] Currently, the main method for leak testing HEPA filters in ventilation systems is the tracer test method. This includes the DOP aerosol test, which involves using a DOP aerosol generator to generate DOP polydisperse aerosol and injecting it into the upstream pipeline of the HEPA filter. A DOP aerosol detector is then used to detect the concentration of DOP aerosol in the upstream and downstream pipelines of the HEPA filter. The leakage rate of the HEPA filter is calculated using the leakage rate formula. The sodium fluorescein aerosol method is also used for HEPA filter performance testing. Tracer test methods also include the iodine adsorber filter leak test, which involves using a halogen gas generator to generate Freon gas and injecting it into the upstream pipeline of the iodine adsorber purification unit of the ventilation system. A halogen gas detector is then used to detect the concentration of halogen gas in the upstream and downstream pipelines of the iodine adsorber. The mechanical leakage rate of the iodine adsorber purification unit is calculated using the leakage rate formula. The cyclohexane method is also used for leak testing of iodine adsorber filters.

[0005] In related technologies, the tracer test method requires the generation of a tracer first, that is, a gas with a labeled DOP polydisperse aerosol or a labeled halogen gas. However, during the tracer generation process, the test aerosol and test gas output ports in the generator are respectively several pipelines, which are in direct contact with the working environment. During use, some pipelines may leak or loosen, causing some radioactive aerosols or reagent gases to enter the external environment, affecting the safety of people in the surrounding environment.

[0006] The above problems need to be solved urgently. Summary of the Invention

[0007] The invention discloses a negative pressure tracer generator and method, aiming to solve the technical problems existing in the prior art.

[0008] The present invention adopts the following technical solutions:

[0009] The present invention provides a negative pressure tracer generator, comprising:

[0010] The negative pressure box is in the shape of a rectangular box, and negative pressure is formed inside the box, including a gas inlet and a gas outlet; a tracer generating gas path is arranged in the negative pressure box, one end of which is connected to the gas inlet, and the other end is connected to the gas outlet, and a tracer component is arranged on the tracer generating gas path, and the tracer component is used to convert the first gas entering the gas inlet into a target tracer gas, and transmit it to the gas outlet; a negative pressure generating gas path is arranged in the negative pressure box, and forms a negative pressure inside the negative pressure box, one end of which is connected to the gas inlet, and the other end is connected to the gas outlet, and a negative pressure generator is arranged on the negative pressure generating gas path, and the negative pressure generator connects the air in the negative pressure box with the negative pressure generating gas path, and the negative pressure generator is used to suck the gas in the negative pressure box into the negative pressure generating gas path, and transmit it to the gas outlet; a purifier is arranged in the negative pressure box, and is connected to the negative pressure generator, and is used to block the target tracer gas in the negative pressure box from being transmitted to the gas outlet.

[0011] Optionally, it also includes: a first pressure gauge, arranged on the negative pressure box, for detecting a first pressure value in the negative pressure box; a first pressure reducing valve, arranged on the negative pressure generating gas path, and located between the gas inlet end and the negative pressure generator, for adjusting the pressure in the negative pressure box; a processor, connected to the first pressure gauge and the first pressure reducing valve, for receiving the first pressure value transmitted by the first pressure gauge, and adjusting the first pressure reducing valve based on the first pressure value.

[0012] Optionally, it also includes: an air pressure regulating port, arranged on the side wall of the negative pressure box body, for connecting the negative pressure box body with the outside air; a flexible barrier sheet, arranged at the air pressure regulating port, and located at the air pressure regulating port inside the negative pressure box body, and the flexible barrier sheet and the air pressure regulating port are detachably connected; when the pressure difference between the air pressure inside the negative pressure box body and the external air pressure is greater than the pulling force of the flexible barrier sheet, the flexible barrier sheet is separated from the air pressure regulating port, and air enters the negative pressure box body from the air pressure regulating port.

[0013] Optionally, the tracer generating gas circuit also includes: an air inlet pipeline, one end of which is connected to the gas inlet and the other end is connected to the tracer assembly, for transmitting the first gas to the tracer assembly; a first tracer output pipeline, one end of which is connected to the tracer assembly and the other end is connected to the gas outlet, and the connection between the first tracer output pipeline and the tracer assembly is located at the upper end of the side wall of the tracer assembly; a second tracer output pipeline, one end of which is connected to the tracer assembly and the other end is connected to the gas outlet, and the connection between the second tracer output pipeline and the tracer assembly is located at the lower end of the side wall of the tracer assembly.

[0014] Optionally, the tracer generating gas circuit also includes: a second pressure reducing valve, arranged on the air intake pipeline and connected to the processor; a second pressure gauge, arranged on the air intake pipeline and located between the second pressure reducing valve and the tracer assembly, for obtaining a second pressure value of the air intake pipeline, the second pressure gauge is connected to the processor; the processor adjusts the second pressure reducing valve based on the second pressure value.

[0015] Optionally, the tracer generating gas circuit further includes: a first check valve, provided on the first tracer output pipeline; and a first ball valve, provided on the first tracer output pipeline and located between the first check valve and the tracer assembly.

[0016] Optionally, the tracer generating gas circuit further includes: a flow meter, arranged on the second tracer output pipeline, for detecting the flow on the second tracer output pipeline; a second check valve, arranged on the second tracer output pipeline, and located between the flow meter and the gas outlet; a second ball valve, arranged on the second tracer output pipeline, and located between the flow meter and the tracer assembly.

[0017] Optionally, it further includes: a liquid adding port, which is arranged on the negative pressure box body and connects the top wall of the negative pressure box body with the tracer assembly, and is used to add tracer liquid into the tracer assembly.

[0018] Optionally, it also includes: a dilution gas circuit, which is arranged inside the negative pressure box, one end of which is connected to the gas inlet, and the other end of which is connected to the connection between the tracer generating gas circuit and the gas outlet; the dilution gas circuit is used to dilute the tracer in the target tracer gas and dry the target tracer gas.

[0019] Optionally, the dilution gas circuit includes: a third pressure reducing valve, arranged on the dilution gas circuit and connected to the processor; a third pressure gauge, arranged on the dilution gas circuit and located between the third pressure reducing valve and the gas outlet, for obtaining third pressure data on the dilution gas circuit, the third pressure gauge being connected to the processor; the processor adjusts the third pressure reducing valve based on the third pressure data.

[0020] Optionally, the gas inlet includes: an air inlet pipe, connecting the external environment with the interior of the negative pressure box; an air inlet valve, arranged on the air inlet pipe, and located at the position of the air inlet pipe inside the negative pressure box; the gas outlet includes: an air outlet pipe, connecting the interior of the negative pressure box with the external environment; an air outlet valve, arranged on the air outlet pipe, and located at the position of the air outlet pipe inside the negative pressure box.

[0021] Optionally, the first gas introduced into the gas inlet is pressurized gas.

[0022] The present invention also provides a negative pressure tracer generation method, which includes: opening an air inlet valve and an air outlet valve to introduce a pressurized first gas from a gas inlet; opening a first pressure reducing valve and a negative pressure generator to form a negative pressure in a negative pressure box based on the negative pressure generator, and adjusting the opening of the first pressure reducing valve based on a first pressure value detected by a first pressure gauge to adjust the negative pressure in the negative pressure box, wherein the first pressure value is used to indicate the negative pressure in the negative pressure box; opening a liquid filling port to add a tracer to a tracer assembly, wherein the tracer is a tracer liquid or aerosol particles; opening a purifier, and in the event of leakage of the tracer, filtering the gas from the inside of the negative pressure box to the negative pressure generator, wherein the first gas enters the negative pressure generator and the tracer remains in the purifier; opening a second pressure reducing valve and a third pressure reducing valve to allow the first gas to enter the tracer assembly, and form a target tracer gas under the action of the tracer, which is discharged into the gas outlet.

[0023] Optionally, the opening of the second pressure reducing valve and the third pressure reducing valve, the first gas entering the tracer assembly, forming a target tracer gas under the action of the tracer, and discharging the target tracer gas into the gas outlet, includes: when the tracer is the tracer liquid, opening the second ball valve, mixing the gas passing through the second ball valve with the first gas passing through the third pressure reducing valve to obtain the target tracer gas, and discharging the target tracer gas into the gas outlet, wherein, based on the flow value obtained by the flowmeter and the third pressure value obtained by the third pressure gauge, the opening of the second ball valve and / or the third pressure reducing valve is changed to adjust the mixing ratio of the target tracer gas; when the tracer is the aerosol particles, the first gas introduced into the gas inlet is mixed with the aerosol particles to form the target tracer gas, opening the first ball valve, and discharging the target tracer gas into the gas outlet, wherein, based on the second pressure value obtained by the second pressure gauge, the opening of the second pressure reducing valve is changed to adjust the mixing ratio of the target tracer gas.

[0024] The technical solution adopted by the present invention can achieve at least one of the following beneficial effects:

[0025] In an embodiment of the present invention, a negative pressure box is in the shape of a rectangular box, negative pressure is formed inside, and the box includes a gas inlet and a gas outlet; a tracer generating gas path is arranged in the negative pressure box, one end of which is connected to the gas inlet and the other end of which is connected to the gas outlet; a tracer assembly is arranged in the tracer generating gas path, and the tracer assembly is used to convert the first gas entering the gas inlet into a target tracer gas and transmit it to the gas outlet; a negative pressure generating gas path is arranged in the negative pressure box, and negative pressure is formed inside the negative pressure box, one end of which is connected to the gas inlet and the other end of which is connected to the gas outlet; a negative pressure generator is arranged in the negative pressure box, and negative pressure is formed inside the negative pressure box, and negative pressure is formed inside the negative pressure box, one end of which is connected to the gas inlet and the other end of which is connected to the gas outlet; the negative pressure generator is connected to the air in the negative pressure box and the negative pressure generating gas path, and the negative pressure generator is used to suck the gas in the negative pressure box into the negative pressure generating gas path and transmit it to the gas outlet; a purifier is arranged in the negative pressure box, and connected to the negative pressure generator, and is used to block the target tracer gas in the negative pressure box from being transmitted to the gas outlet. The purpose of arranging the tracer generating gas path in the negative pressure box, forming a negative pressure state of the negative pressure box through the negative pressure generating gas path in the negative pressure box, and when there is a tracer generating gas path leakage, the target tracer gas leaks into the negative pressure box, and the radioactive substances in the target tracer gas are intercepted by the purifier connected to the negative pressure generator, thereby achieving the technical effect of preventing the radioactive substances from being dispersed into the external environment when the tracer generating gas path leaks, thereby endangering the safety of surrounding personnel, and further solving the technical problem that the pipeline is in direct contact with the working environment, and some pipelines may leak or loosen during use, causing some radioactive aerosols or reagent gases to enter the external environment, thereby affecting the safety of people in the surrounding environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments, which constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0027] Figure 1 1 is a schematic structural diagram of a negative pressure tracer generator in Example 1 of the present invention;

[0028] Figure 2 This is a flow chart of a negative pressure tracer generation method in Example 1 of the present invention.

[0029] Description of reference numerals:

[0030] 1. Negative pressure chamber; 11. Gas inlet; 111. Inlet pipe; 112. Inlet valve; 12. Gas outlet; 121. Outlet pipe; 122. Outlet valve; 13. Air pressure regulating port; 14. Flexible barrier; 15. Liquid filling port;

[0031] 2. Tracer generating gas line; 21. Tracer assembly; 22. Air inlet line; 221. Second pressure reducing valve; 222. Second pressure gauge; 23. First tracer output line; 231. First check valve; 232. First ball valve; 24. Second tracer output line; 241. Flow meter; 242. Second check valve; 243. Second ball valve;

[0032] 3. Negative pressure generating gas circuit; 31. Negative pressure generator; 32. Purifier; 33. First pressure gauge; 34. First pressure reducing valve;

[0033] 4. Dilution gas line; 41. Third pressure reducing valve; 42. Third pressure gauge. DETAILED DESCRIPTION

[0034] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. In the description of the present invention, it should be noted that the term "or" is generally used in the sense of including "and / or" unless the content clearly indicates otherwise.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or a magnetic connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the 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. In addition, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three or more, etc., unless otherwise clearly specified and limited.

[0036] Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] First, to facilitate understanding of the embodiments of the present invention, some of the terms or nouns involved in the present invention are explained below:

[0038] Tracers are special substances used to track, mark or detect target substances or processes. They form distinguishable signals from the main system through their physical, chemical or biological properties, thereby revealing the movement patterns, distribution characteristics or reaction mechanisms of the target objects.

[0039] To solve the problems existing in the prior art, the embodiments of the present application provide a negative pressure tracer generator and method.

[0040] Example 1

[0041] This embodiment provides a negative pressure tracer generator, such as Figure 1 As shown, Figure 1 : is a schematic structural diagram of a negative pressure tracer generator in Example 1 of the present invention, wherein the negative pressure generator 31 comprises:

[0042] The negative pressure box 1 is in the shape of a rectangular box, and negative pressure is formed inside, including a gas inlet 11 and a gas outlet 12; a tracer generating gas path 2 is arranged in the negative pressure box 1, one end of which is connected to the gas inlet 11, and the other end is connected to the gas outlet 12, and a tracer component 21 is provided on the tracer generating gas path 2, and the tracer component 21 is used to convert the first gas entering at the gas inlet 11 into a target tracer gas and transmit it to the gas outlet 12; a negative pressure generating gas path 3 is arranged in the negative pressure box 1, and the negative pressure box 1 is connected to the gas inlet 11. A negative pressure is formed inside, one end is connected to the gas inlet 11, and the other end is connected to the gas outlet 12. A negative pressure generator 31 is provided on the negative pressure generating gas circuit 3. The negative pressure generator 31 connects the air in the negative pressure box 1 with the negative pressure generating gas circuit 3. The negative pressure generator 31 is used to suck the gas in the negative pressure box 1 into the negative pressure generating gas circuit 3 and transmit it to the gas outlet 12; the purifier 32 is provided in the negative pressure box 1 and connected to the negative pressure generator 31, and is used to block the target tracer gas in the negative pressure box 1 from being transmitted to the gas outlet 12.

[0043] Based on the above structure, the tracer generation circuit 2 includes a tracer assembly 21, a rectangular box containing a tracer liquid. When a first gas is introduced into the tracer assembly 21, it comes into contact with the tracer liquid, carrying along the labeled molecules in the tracer liquid to form a target tracer gas. This target tracer gas is then output as the gas required for the tracer test method.

[0044] Optionally, the outer side of the tracer gas generating circuit 2 is set in the negative pressure box 1. When the tracer gas generating circuit 2 leaks, the leaked target tracer gas diffuses into the negative pressure box 1 but does not diffuse into the external environment, effectively ensuring the safety of surrounding personnel.

[0045] Optionally, a negative pressure generating gas circuit 3 is provided in the negative pressure box 1. A negative pressure generator 31 connected to the negative pressure generating gas circuit 3 draws the gas in the negative pressure box 1 into the negative pressure generating gas circuit 3 and discharges it to the gas outlet 12, thereby forming a negative pressure inside the negative pressure box 1. When a negative pressure is formed in the negative pressure box 1, if the target tracer gas leaks, it will be sucked into the negative pressure gas circuit by the suction effect of the negative pressure generator 31 and reach the gas outlet 12. At the gas outlet 12, the target tracer gas converges with the gas recovered after the leak and is transmitted together to the upstream of the ventilation system purification unit to be used as test gas to verify the purification function of the ventilation system purification unit.

[0046] Optionally, after the first gas enters the tracer assembly 21, it must be uniformly mixed with the labeled molecules in the target tracer gas before being discharged to the gas outlet 12. However, the tracer gas generation circuit 2 may leak anywhere in the pipeline. If the leaked gas is directly recovered at the gas outlet 12 to be mixed with the target tracer gas, there may be an excess of labeled molecules in the recovered gas, resulting in an increase in the number of labeled molecules in the target tracer gas ultimately output, thus affecting subsequent measurement results. A purifier 32 can be connected to the negative pressure generator 31. The gas drawn into the negative pressure chamber 1 by the negative pressure generator 31 will be filtered by the purifier 32, preventing the labeled molecules from reaching the gas outlet 12. Once the filtered gas reaches the gas outlet 12, it is free of labeled molecules and thus does not affect the labeled molecule content of the target tracer gas, nor does it affect subsequent detection results.

[0047] Among them, there is an adsorption material in the purifier 32 that can absorb the marker molecules in the target tracer gas. After the target tracer gas passes through the purifier 32, the aerosol particles or tracer liquid molecules corresponding to the marker molecules will be absorbed by the adsorption material, thereby discharging the first gas in the target tracer gas, and the substance carrying the marker molecules will be left in the purifier 32.

[0048] Optionally, by setting the tracer generating gas circuit 2 in the negative pressure box 1, the negative pressure generating gas circuit 3 in the negative pressure box 1 forms a negative pressure state of the negative pressure box 1. When there is a leakage in the tracer generating gas circuit 2, the target tracer gas leaks into the negative pressure box 1, and the radioactive labeled molecules in the target tracer gas are intercepted by the purifier 32 connected to the negative pressure generator 31, thereby achieving the technical effect of preventing the radioactive labeled molecules from spreading into the external environment when the tracer generating gas circuit 2 leaks, thereby endangering the safety of surrounding personnel. This solves the technical problem that the pipeline is in direct contact with the working environment, and some pipelines may leak or loosen during use, causing some radioactive aerosols or reagent gases to enter the external environment, affecting the safety of people in the surrounding environment.

[0049] This embodiment preferably also includes: a first pressure gauge 33, which is arranged on the negative pressure box 1 and is used to detect the first pressure value in the negative pressure box 1; a first pressure reducing valve 34, which is arranged on the negative pressure generating gas path 3 and is located between the gas inlet 11 end and the negative pressure generator 31, and is used to adjust the pressure in the negative pressure box 1; a processor, which is connected to the first pressure gauge 33 and the prime first pressure reducing valve 34, and is used to receive the first pressure value transmitted by the first pressure gauge 33, and adjust the first pressure reducing valve 34 based on the first pressure value.

[0050] Based on the above structure, a negative pressure phenomenon is formed in the negative pressure box 1. In order to avoid deformation of the negative pressure box 1 due to a large negative pressure, or most of the gas being sucked into the purifier 32 under the action of negative pressure after the tracer leaks in the gas path 2, it is necessary to monitor the first pressure value in the negative pressure box 1. When the first pressure value is between 300 Pa and 600 Pa, it means that the negative pressure in the negative pressure box 1 is normal; when the first pressure value is less than 300 Pa, it means that the pressure in the negative pressure box 1 is small and the suction effect needs to be increased, so the opening of the first pressure reducing valve 34 is adjusted to increase the flow rate of the first gas at the gas inlet 11 end entering the negative pressure generator 31, thereby increasing the rotation of the negative pressure generator 31 and increasing the suction speed of the negative pressure generator 31, thereby achieving the effect of increasing the negative pressure in the negative pressure box 1; when the first pressure value is greater than 600 Pa, it means that the negative pressure in the negative pressure box 1 is large, and it is necessary to reduce the opening of the first pressure reducing valve 34 and reduce the suction speed to achieve the effect of reducing the negative pressure in the negative pressure box 1.

[0051] Optionally, by setting a processor, the first pressure value of the first pressure gauge 33 is obtained, and the first pressure reducing valve 34 is automatically adjusted based on whether the first pressure value is within the range of 300Pa to 600Pa, thereby realizing an automated process, reducing the workload of staff, and reducing waste of human resources.

[0052] This embodiment preferably also includes: an air pressure regulating port 13, which is arranged on the side wall of the negative pressure box 1 and is used to connect the negative pressure box 1 with the outside air; a flexible barrier sheet 14, which is arranged at the air pressure regulating port 13 and is located at the air pressure regulating port 13 inside the negative pressure box 1, and the flexible barrier sheet 14 and the air pressure regulating port 13 are detachably connected; when the pressure difference between the air pressure inside the negative pressure box 1 and the external air pressure is greater than the pulling force of the flexible barrier sheet 14, the flexible barrier sheet 14 is separated from the air pressure regulating port 13, and the air enters the negative pressure box 1 through the air pressure regulating port 13.

[0053] Based on the above structure, in order to balance the air pressure in the negative pressure box 1 and avoid a high negative pressure state in the negative pressure box 1, the first pressure reducing valve 34 adjustment failure causes the pressure value in the negative pressure box 1 to be unable to be adjusted, an air pressure regulating port 13 can be provided, and a flexible barrier sheet 14 can be provided at the air pressure regulating port 13. The flexible barrier sheet 14 is made of rubber and has a certain degree of flexibility. The flexible barrier sheet 14 is placed at the air pressure regulating port 13, and the flexible barrier sheet 14 is connected to the air pressure regulating port 13 through a partially flexible connecting strip. When As the negative pressure inside the negative pressure box 1 increases, the pressure inside the negative pressure box 1 increases. At the air pressure regulating port 13, there will be a force from the external environment to the inside of the negative pressure box 1, sucking air into the negative pressure box 1. At this time, when the force is greater than the flexible pulling force of the flexible barrier sheet 14, the flexible barrier sheet 14 will separate from the air pressure regulating port 13, allowing air to enter the negative pressure box 1, thereby realizing the negative pressure regulation inside the negative pressure box 1, and preventing the negative pressure from continuing to increase and causing damage to the negative pressure box 1 and the pipelines inside the negative pressure box 1.

[0054] Optionally, the flexible barrier sheet 14 is connected to the air pressure regulating port 13 via a flexible connecting strip. The connecting strip may be made of rubber, and there are multiple connecting strips that are evenly distributed between the air pressure regulating port 13 and the flexible barrier sheet 14 .

[0055] Preferably, in this embodiment, the tracer generating gas circuit 2 further includes: an air inlet pipeline 22, one end of which is connected to the gas inlet 11 and the other end is connected to the tracer assembly 21, for transmitting the first gas to the tracer assembly 21; a first tracer output pipeline 23, one end of which is connected to the tracer assembly 21 and the other end is connected to the gas outlet 12, and the connection between the first tracer output pipeline 23 and the tracer assembly 21 is located at the upper end of the side wall of the tracer assembly 21; a second tracer output pipeline 24, one end of which is connected to the tracer assembly 21 and the other end is connected to the gas outlet 12, and the connection between the second tracer output pipeline 24 and the tracer assembly 21 is located at the lower end of the side wall of the tracer assembly 21.

[0056] Based on the above structure, the tracer assembly 21 can be a rectangular box or cylindrical, and can be a container for a solution or gas. The air inlet 22 is connected to the gas inlet 11, through which a first gas is introduced. The first gas passes through the tracer assembly 21, where it reacts with or fuses with the substances within the tracer assembly 21. The gas discharged from the tracer assembly 21 is the target tracer gas.

[0057] Optionally, when the tracer in the tracer assembly 21 is aerosol particles, the aerosol particles are in gas form (for example, haze particles are aerosol particles), and the gaseous aerosol particles are mixed with the first gas and output based on the first tracer output pipeline 23. Since the mixed target tracer gas is in gas form and is squeezed by the continuously entering first gas, it will be discharged from the upper end of the tracer assembly 21. Therefore, the first tracer output pipeline 23 is set at the upper end of the side wall of the tracer assembly 21 to effectively discharge the gas.

[0058] Optionally, when the tracer in the tracer assembly 21 is in liquid form, the liquid tracer must be volatile. When the first gas is injected into the tracer assembly 21, since the liquid is located at the lower end of the tracer assembly 21, the first gas pushes the liquid tracer downward, causing it to flow out through the second tracer output conduit 24 at the lower end of the tracer assembly 21. Since the liquid tracer is volatile, after being squeezed into the second tracer output conduit 24, it gradually transforms into a volatile gas, which is then discharged into the gas outlet 12 as the target tracer gas.

[0059] Optionally, two output pipelines are provided: one at the upper end of the tracer assembly 21 and the other at the lower end. This effectively allows for the generation of target tracer gas in various forms. When the tracer is aerosol particles, it can be discharged through the first tracer output pipeline 23. When the tracer is a volatile liquid, it can be discharged through the second tracer output pipeline 24, effectively achieving a wider adaptability of the tracer assembly 21.

[0060] Preferably, in this embodiment, the tracer generating gas circuit 2 further includes: a second pressure reducing valve 221, which is provided on the air intake pipeline 22 and connected to the processor; a second pressure gauge 222, which is provided on the air intake pipeline 22 and is located between the second pressure reducing valve 221 and the tracer assembly 21, and is used to obtain a second pressure value of the air intake pipeline 22, and the second pressure gauge 222 is connected to the processor; the processor adjusts the second pressure reducing valve 221 based on the second pressure value.

[0061] Based on the above structure, a second pressure reducing valve 221 and a second pressure gauge 222 are provided on the air inlet line 22. As the first gas is introduced into the tracer assembly 21 through the air inlet line 22, the flow rate and volume of the first gas can be adjusted by opening and closing the second pressure reducing valve 221. If the target tracer gas is produced rapidly, the amount of the first gas introduced can be reduced to slow the production rate of the target tracer gas.

[0062] Optionally, based on the second pressure gauge 222, the gas flow rate in the intake pipe 22 can be determined, and the processor automatically controls the opening of the second pressure reducing valve 221 based on the second pressure value obtained from the second pressure gauge 222 to achieve the effect of automatically adjusting the first gas flow rate.

[0063] Preferably, in this embodiment, the tracer generating gas circuit 2 further includes: a first check valve 231 , which is provided on the first tracer output pipeline 23 ; and a first ball valve 232 , which is provided on the first tracer output pipeline 23 and is located between the first check valve 231 and the tracer assembly 21 .

[0064] Based on the above structure, a first check valve 231 is provided on the first tracer output pipeline 23 to prevent the target tracer gas from flowing back from the gas outlet 12 into the tracer assembly 21, thereby affecting subsequent gas detection. The internal valve disc of the first check valve 231 opens and closes under the pressure of the target tracer gas. When the target tracer gas and the tracer assembly 21 flow toward the gas outlet 12, the pressure acts on the valve disc, overcoming its gravity and spring force, causing it to move and open the valve, allowing the target tracer gas to pass smoothly. However, if the target tracer gas stops flowing or attempts to reverse flow, the valve disc quickly falls back to its seat due to the combined effects of its own gravity, spring force, and reverse gas pressure, closing the valve and preventing the target tracer gas from flowing back.

[0065] Optionally, a first ball valve 232 is provided on the first tracer pipeline. The first ball valve 232 is a spherical opening and closing component driven by a valve stem, and is a valve that rotates around the axis of the ball valve. It opens and closes the valve by rotating the ball 90°. When the operating mechanism drives the valve stem to rotate, the valve stem transmits torque to the ball, causing the ball to rotate 90° around the axis of the valve body. At this time, the through hole on the ball is aligned with the axis of the first tracer output pipeline 23, and the target tracer gas can pass through the valve smoothly, and the valve is in an open state. The first ball valve 232 is used to control the outflow rate of the target tracer gas, thereby controlling the outflow volume of the target tracer gas, and effectively controlling the amount of the target tracer gas output to the gas outlet 12.

[0066] Preferably, in this embodiment, the tracer generating gas circuit 2 further includes: a flow meter 241, which is provided on the second tracer output pipeline 24 and is used to detect the flow on the second tracer output pipeline 24; a second check valve 242, which is provided on the second tracer output pipeline 24 and is located between the flow meter 241 and the gas outlet 12; and a second ball valve 243, which is provided on the second tracer output pipeline 24 and is located between the flow meter 241 and the tracer assembly 21.

[0067] Based on the above structure, the second check valve 242 effectively prevents the target tracer gas from flowing in the opposite direction from the gas outlet 12 to the tracer assembly 21. The second ball valve 243 effectively adjusts the output of the target tracer gas.

[0068] Optionally, a flow meter 241 is provided on the second tracer output pipeline 24. Since the second tracer output pipeline 24 is provided at the lower end of the tracer assembly 21, the tracer liquid is pressed into the second tracer output pipeline 24 and gradually evaporates into a gaseous form. The volume of the liquid is different from the volume of the gas. Therefore, it is necessary to provide a flow meter 241 to determine the liquid flow entering the second tracer output pipeline 24, thereby determining the gas volume of the second tracer output pipeline 24, and effectively controlling the amount of target tracer gas reaching the gas outlet 12.

[0069] Preferably, this embodiment further comprises: a liquid adding port 15 , which is provided on the negative pressure box 1 and connects the top wall of the negative pressure box 1 with the tracer assembly 21 , and is used for adding tracer liquid into the tracer assembly 21 .

[0070] Based on the above structure, tracer liquid or tracer aerosol particles are added to the tracer component 21. Since a negative pressure box 1 is provided outside the tracer component 21, a liquid adding port 15 needs to be provided on the negative pressure box 1, and a connecting pipe needs to be provided from the liquid adding port 15 of the negative pressure box 1 to the top wall of the tracer component 21, so that the tracer liquid can accurately enter the tracer component 21 through the liquid adding port 15.

[0071] Preferably, this embodiment further includes: a dilution gas circuit 4, which is arranged inside the negative pressure box 1, one end of which is connected to the gas inlet 11, and the other end is connected to the connection between the tracer generating gas circuit 2 and the gas outlet 12; the dilution gas circuit 4 is used to dilute the tracer in the target tracer gas and dry the target tracer gas.

[0072] Based on the above structure, when the tracer placed in the tracer assembly 21 is aerosol particles, the first gas enters the tracer assembly 21, and the first gas is mixed with the aerosol particles and then discharged, so that the target tracer gas is a diluted gas, that is, there are air and aerosol particles in the gas, which is similar to the aerosol gas generated in actual production.

[0073] However, when a tracer liquid is placed in the tracer assembly 21, the target tracer gas is squeezed to the gas outlet 12 by the first gas, and the target tracer gas fails to mix with the first gas. Moreover, the gas after the liquid evaporates carries a large amount of water and easily turns back into liquid after being cooled. Therefore, a dilution gas path 4 is provided, and the dilution gas path 4 is connected to the tracer generating gas path 2, and the connection point is located at the gas outlet 12. At this point, the first gas and the gas converted from the liquid into a gaseous state meet and mix to form the target tracer gas, effectively achieving that the target tracer gas is similar to the gas generated in actual production and meets the standards of subsequent experiments.

[0074] Optionally, the first gas is relatively dry, and the first gas in the dilution gas path 4 is mixed with the gas converted from liquid to gas to form the target tracer gas, thereby reducing the water content in the target tracer gas, thereby achieving the effect of drying the target tracer gas and preventing the target tracer gas from turning back into liquid after being cooled.

[0075] Preferably, in this embodiment, the dilution gas circuit 4 includes: a third pressure reducing valve 41, which is arranged on the dilution gas circuit 4 and connected to the processor; a third pressure gauge 42, which is arranged on the dilution gas circuit 4 and is located between the third pressure reducing valve 41 and the gas outlet 12, and is used to obtain third pressure data on the dilution gas circuit 4, and the third pressure gauge 42 is connected to the processor; the processor adjusts the third pressure reducing valve 41 based on the third pressure data.

[0076] Based on the above structure, a third pressure reducing valve 41 and a third pressure gauge 42 are installed in the dilution gas line 4. The flow rate of the liquid extruded into the second tracer output line 24 can be determined using the flow meter 241 on the second tracer output line 24, thereby determining the volume of gas formed from the liquid in the second tracer output line 24. Furthermore, the flow rate of the first gas in the dilution gas line 4 can be determined using the third pressure gauge 42. The gas volume and the flow rate of the first gas are used to adjust the openings of the third pressure valve and the second ball valve 243 to achieve the desired mixing ratio of the target tracer gas. This effectively adjusts the target tracer gas to the same level as the polluted gas generated during actual production, significantly improving the accuracy of subsequent experimental verification (subsequent experiments will verify how many labeled molecules remain in the target tracer gas after it has been treated by the ventilation system, thereby determining the effectiveness of the ventilation system).

[0077] Preferably, in this embodiment, the gas inlet 11 includes: an air intake pipe 111, connecting the external environment with the interior of the negative pressure box 1; an air intake valve 112, arranged on the air intake pipe 111, and located at the position of the air intake pipe 111 in the negative pressure box 1; the gas outlet 12 includes: an air outlet pipe 121, connecting the interior of the negative pressure box 1 with the external environment; an air outlet valve 122, arranged on the air outlet pipe 121, and located at the position of the air outlet pipe 121 in the negative pressure box 1.

[0078] Based on the above structure, an air intake pipe 111 is set at other entrances, and an air intake valve 112 is set at the air intake pipe 111. When there is a demand for target tracer gas production, the air intake valve 112 is opened to realize the use of the negative pressure box 1 and the air intake pipe 111. After use, the air intake valve 112 is closed, and the leaked gas in the negative pressure box 1 is emptied through the negative pressure generating air path 3, and the gas or liquid in the tracer assembly 21 is discharged at the same time. When ensuring that there is no radioactive gas or liquid in the negative pressure box 1 and the internal pipeline, the air outlet valve 122 on the air outlet pipe 121 is closed, so that the negative pressure box 1 and the internal pipeline are in a closed state. At this time, the negative pressure box 1 can be separated from the upstream experimental equipment and the downstream experimental equipment, and the negative pressure box 1 can be stored or transported separately.

[0079] In this embodiment, preferably, the first gas introduced into the gas inlet 11 is pressurized gas.

[0080] Based on the above structure, the first gas is pressurized so that when the first gas enters the negative pressure generating gas path 3, the pressurized first gas provides power to drive the working components within the negative pressure generator 31 to rotate, thereby achieving normal operation of the negative pressure generator 31. The amount of first gas entering can be adjusted by the first pressure reducing valve 34, thereby adjusting the power of the negative pressure generator 31 to achieve the working intensity of the negative pressure generator 31.

[0081] Optionally, the first gas is pressurized. After pressurization, the moisture in the gas forms a liquid and is retained, and the water content in the first gas is reduced. The first gas is mixed with the gas output from the second tracer output pipeline 24 through the dilution gas path 4, effectively reducing the water content of the gas output from the second tracer output pipeline 24, thereby reducing the water content of the target tracer gas, thereby achieving a gas drying effect.

[0082] Optionally, the first gas is pressurized so that there is a certain pressure when the first gas enters the tracer assembly 21, thereby making it easier to press the tracer liquid out to the second tracer output pipeline 24 by pressure, thereby effectively achieving the generation of target tracer gas.

[0083] Example 2

[0084] Based on the above embodiment, the present invention further proposes an optional implementation method, including:

[0085] The negative pressure tracer generator is provided with a negative pressure box 1, and the liquid filling port 15, gas inlet 11, gas outlet 12 and all gas pipelines are placed inside the negative pressure box 1. Under the action of the negative pressure inside the negative pressure box 1, the channel for the overflowed or leaked tracer to diffuse from the negative pressure tracer generator to the surrounding environment is blocked.

[0086] The size of the negative pressure box 1 with a certain degree of sealing is determined based on the size of the internal pipeline of the negative pressure tracer generator. A negative pressure generator 31, a first pressure gauge 33, and an interface that can be connected to the tracer generating gas circuit 2 are installed inside the negative pressure box 1. The air inlet of the negative pressure generator 31 is connected to the gas inlet 11 of the compressed air (first gas), and the exhaust port is connected to the position where the tracer output pipeline is connected to the gas outlet 12. The vacuum port of the negative pressure generator 31 is connected to the internal space of the negative pressure box 1. In this way, after the compressed air is connected, the first pressure reducing valve 34 is adjusted while observing the negative pressure value (first pressure value) in the negative pressure box 1. After the negative pressure value reaches the predetermined value, the tracer injection operation is performed to achieve the production of the target tracer gas.

[0087] Example 3

[0088] Based on the above embodiments and optional embodiments, the present invention further proposes a method for generating a negative pressure tracer, comprising:

[0089] Step S1, opening the air inlet valve 112 and the air outlet valve 122, and introducing the pressurized first gas from the gas inlet 11;

[0090] Step S2: Open the first pressure reducing valve 34 and the negative pressure generator 31, generate a negative pressure in the negative pressure box 1 based on the negative pressure generator 31, and adjust the opening of the first pressure reducing valve 34 based on the first pressure value detected by the first pressure gauge 33 to adjust the negative pressure in the negative pressure box 1 of the pressure reducing valve, wherein the first pressure value of the pressure reducing valve is used to indicate the negative pressure in the negative pressure box 1 of the pressure reducing valve;

[0091] Step S3, opening the liquid adding port 15 and adding a tracer into the tracer assembly 21, wherein the pressure reducing valve tracer is a tracer liquid or aerosol particles;

[0092] Step S4, opening the purifier 32, filtering the gas from the inside of the pressure reducing valve negative pressure box 1 to the pressure reducing valve negative pressure generator 31 in the event of a pressure reducing valve tracer leak, wherein the first gas enters the negative pressure generator 31 and the tracer remains in the purifier 32;

[0093] In step S5 , the second pressure reducing valve 221 and the third pressure reducing valve 41 are opened, and the first gas from the pressure reducing valve enters the pressure reducing valve tracer assembly 21 , forms target tracer gas under the action of the pressure reducing valve tracer, and is discharged into the gas outlet 12 .

[0094] In this embodiment, the pressure reducing valve preferably opens the second pressure reducing valve 221 and the third pressure reducing valve 41, and the first gas of the pressure reducing valve enters the pressure reducing valve tracer assembly 21, forms the target tracer gas under the action of the pressure reducing valve tracer, and is discharged into the gas outlet 12, including:

[0095] When the pressure reducing valve tracer is a pressure reducing valve tracer liquid, the second ball valve 243 is opened, and the gas passing through the second ball valve 243 of the pressure reducing valve is mixed with the first gas passing through the third pressure reducing valve 41 of the pressure reducing valve to obtain the pressure reducing valve target tracer gas, which is discharged into the pressure reducing valve gas outlet 12. The openings of the second ball valve 243 and / or the third pressure reducing valve 41 of the pressure reducing valve are changed based on the flow value obtained by the flow meter 241 and the third pressure value obtained by the third pressure gauge 42 to adjust the mixing ratio of the pressure reducing valve target tracer gas.

[0096] In the case where the pressure reducing valve tracer is pressure reducing valve aerosol particles, the first gas introduced into the pressure reducing valve gas inlet 11 is mixed with the pressure reducing valve aerosol particles to form a target tracer gas, and the first ball valve 232 is opened to discharge the pressure reducing valve target tracer gas into the pressure reducing valve gas outlet 12. Specifically, based on the second pressure value obtained by the second pressure gauge 222 of the pressure reducing valve, the opening of the second pressure reducing valve 221 of the pressure reducing valve is changed to adjust the mixing ratio of the target tracer gas of the pressure reducing valve.

[0097] The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A negative pressure tracer generator, characterized in that: include: The negative pressure box (1) is in the shape of a rectangular box, forms a negative pressure inside, and includes a gas inlet (11) and a gas outlet (12); A tracer generating gas circuit (2) is provided in the negative pressure box (1), one end of which is connected to the gas inlet (11) and the other end of which is connected to the gas outlet (12). A tracer assembly (21) is provided on the tracer generating gas circuit (2), and the tracer assembly (21) is used to convert the first gas entering the gas inlet (11) into a target tracer gas and transmit the target tracer gas to the gas outlet (12). A negative pressure generating gas circuit (3) is provided in the negative pressure box (1) to form a negative pressure inside the negative pressure box (1), one end of which is connected to the gas inlet (11) and the other end of which is connected to the gas outlet (12). A negative pressure generator (31) is provided on the negative pressure generating gas circuit (3), and the negative pressure generator (31) connects the air in the negative pressure box (1) with the negative pressure generating gas circuit (3). The negative pressure generator (31) is used to draw the gas in the negative pressure box (1) into the negative pressure generating gas circuit (3) and transmit it to the gas outlet (12). A purifier (32) is arranged in the negative pressure box (1) and connected to the negative pressure generator (31), and is used to prevent the target tracer gas in the negative pressure box (1) from being transmitted to the gas outlet (12).

2. A negative pressure tracer generator according to claim 1, characterized in that: Also includes: A first pressure gauge (33) is provided on the negative pressure box (1) and is used to detect a first pressure value in the negative pressure box (1); a first pressure reducing valve (34), provided on the negative pressure generating gas path (3) and located between the gas inlet (11) and the negative pressure generator (31), for regulating the pressure in the negative pressure box (1); A processor is connected to the first pressure gauge (33) and the first pressure reducing valve (34), and is used to receive the first pressure value transmitted by the first pressure gauge (33) and adjust the first pressure reducing valve (34) based on the first pressure value.

3. A negative pressure tracer generator according to claim 1, characterized in that: Also includes: An air pressure regulating port (13) is provided on the side wall of the negative pressure box (1) and is used to connect the negative pressure box (1) with the outside air; A flexible barrier sheet (14) is provided at the air pressure regulating port (13) and is located at the air pressure regulating port (13) in the negative pressure box (1), and the flexible barrier sheet (14) and the air pressure regulating port (13) are detachably connected; When the pressure difference between the air pressure inside the negative pressure box (1) and the external air pressure is greater than the pulling force of the flexible barrier sheet (14), the flexible barrier sheet (14) is separated from the air pressure regulating port (13), and air enters the negative pressure box (1) through the air pressure regulating port (13).

4. A negative pressure tracer generator according to claim 1, characterized in that: The tracer generating gas path (2) further comprises: an air inlet pipe (22), one end of which is connected to the gas inlet (11) and the other end of which is connected to the tracer assembly (21), for transmitting the first gas to the tracer assembly (21); a first tracer output pipeline (23), one end of which is connected to the tracer assembly (21), and the other end of which is connected to the gas outlet (12), and a connection point between the first tracer output pipeline (23) and the tracer assembly (21) is located at an upper end of a side wall of the tracer assembly (21); A second tracer output pipeline (24) is connected to the tracer assembly (21) at one end and to the gas outlet (12) at the other end, and the connection between the second tracer output pipeline (24) and the tracer assembly (21) is located at the lower end of the side wall of the tracer assembly (21).

5. A negative pressure tracer generator according to claim 4, characterized in that: The tracer generating gas path (2) further comprises: a second pressure reducing valve (221), disposed on the air inlet pipeline (22) and connected to the processor; a second pressure gauge (222) provided on the air intake pipeline (22) and located between the second pressure reducing valve (221) and the tracer assembly (21), for obtaining a second pressure value of the air intake pipeline (22); the second pressure gauge (222) being connected to a processor; The processor adjusts the second pressure reducing valve (221) based on the second pressure value.

6. A negative pressure tracer generator according to claim 4, characterized in that: The tracer generating gas path (2) further comprises: a first check valve (231) provided on the first tracer output pipeline (23); The first ball valve (232) is provided on the first tracer output pipeline (23) and is located between the first check valve (231) and the tracer assembly (21).

7. A negative pressure tracer generator according to claim 4, characterized in that: The tracer generating gas path (2) further comprises: a flow meter (241), provided on the second tracer output pipeline (24), for detecting the flow rate on the second tracer output pipeline (24); a second check valve (242) provided on the second tracer output pipeline (24) and located between the flow meter (241) and the gas outlet (12); A second ball valve (243) is provided on the second tracer output pipeline (24) and is located between the flow meter (241) and the tracer assembly (21).

8. The negative pressure tracer generator according to claim 1, characterized in that: Also includes: A liquid adding port (15) is provided on the negative pressure box (1), communicating the top wall of the negative pressure box (1) with the tracer assembly (21), and is used for adding tracer liquid into the tracer assembly (21).

9. The negative pressure tracer generator according to claim 1, characterized in that: Also includes: A dilution gas path (4) is provided inside the negative pressure box (1), one end of which is connected to the gas inlet (11), and the other end of which is connected to the connection between the tracer generating gas path (2) and the gas outlet (12); The dilution gas circuit (4) is used to dilute the tracer in the target tracer gas and to dry the target tracer gas.

10. A negative pressure tracer generator according to claim 9, characterized in that: The dilution gas circuit (4) comprises: a third pressure reducing valve (41), provided on the dilution gas path (4) and connected to the processor; a third pressure gauge (42), provided on the dilution gas path (4) and located between the third pressure reducing valve (41) and the gas outlet (12), for obtaining third pressure data on the dilution gas path (4), the third pressure gauge (42) being connected to the processor; The processor adjusts the third pressure reducing valve (41) based on the third pressure data.

11. The negative pressure tracer generator according to claim 1, characterized in that: The gas inlet (11) comprises: an air intake pipe (111) connecting the external environment with the interior of the negative pressure box (1); an air intake valve (112) provided on the air intake pipe (111) and located at a position of the air intake pipe (111) inside the negative pressure box (1); The gas outlet (12) comprises: an air outlet pipe (121) connecting the interior of the negative pressure box (1) with the external environment; and an air outlet valve (122) provided on the air outlet pipe (121) and located at a position of the air outlet pipe (121) inside the negative pressure box (1).

12. The negative pressure tracer generator according to claim 1, characterized in that: The first gas introduced into the gas inlet (11) is pressurized gas.

13. A method for generating a negative pressure tracer, characterized in that: A negative pressure tracer generator according to any one of claims 1 to 12, comprising: Open the air inlet valve (112) and the air outlet valve (122), and introduce the pressurized first gas from the gas inlet (11); Opening the first pressure reducing valve (34) and the negative pressure generator (31), forming a negative pressure in the negative pressure box (1) based on the negative pressure generator (31), and adjusting the opening of the first pressure reducing valve (34) based on a first pressure value detected by a first pressure gauge (33), thereby adjusting the magnitude of the negative pressure in the negative pressure box (1), wherein the first pressure value is used to indicate the magnitude of the negative pressure in the negative pressure box (1); Opening the liquid adding port (15) and adding a tracer into the tracer assembly (21), wherein the tracer is a tracer liquid or aerosol particles; opening the purifier (32) and filtering the gas from the interior of the negative pressure box (1) to the negative pressure generator (31) in the event of a tracer leak, wherein the first gas enters the negative pressure generator (31) and the tracer remains in the purifier (32); The second pressure reducing valve (221) and the third pressure reducing valve (41) are opened, and the first gas enters the tracer assembly (21), forms target tracer gas under the action of the tracer, and is discharged into the gas outlet (12).

14. A method for generating a negative pressure tracer according to claim 13, characterized in that: The second pressure reducing valve (221) and the third pressure reducing valve (41) are opened, the first gas enters the tracer assembly (21), forms target tracer gas under the action of the tracer, and is discharged into the gas outlet (12), comprising: In the case where the tracer is the tracer liquid, the second ball valve (243) is opened, and the gas passing through the second ball valve (243) is mixed with the first gas passing through the third pressure reducing valve (41) to obtain the target tracer gas, which is discharged into the gas outlet (12), wherein the opening of the second ball valve (243) and / or the third pressure reducing valve (41) is changed based on the flow value obtained by the flow meter (241) and the third pressure value obtained by the third pressure gauge (42) to adjust the mixing ratio of the target tracer gas; In the case where the tracer is the aerosol particles, the first gas introduced into the gas inlet (11) is mixed with the aerosol particles to form a target tracer gas, and the first ball valve (232) is opened to discharge the target tracer gas into the gas outlet (12), wherein the opening of the second pressure reducing valve (221) is changed based on the second pressure value obtained by the second pressure gauge (222) to adjust the mixing ratio of the target tracer gas.

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