Gas detection system

Abstract

The invention discloses a gas detection system, the gas detection system is used for detecting target elements in gas to be detected, and the gas detection system comprises a gas inlet unit, an impurity removal unit, a sampling unit and a detection unit; the gas outlet end of the gas inlet unit is connected with the gas inlet end of the impurity removal unit, the gas outlet end of the impurity removal unit is connected with the gas inlet end of the sampling unit, the gas outlet end of the sampling unit is connected with the gas inlet end of the detection unit, the impurity removal unit is used for filtering impurities in gas to be detected, and the sampling unit is used for adsorbing target elements from the gas to be detected and desorbing the target elements. And the detection unit is used for detecting the target element desorbed from the sampling unit. The gas detection system provided by the invention can improve the detection precision of low-concentration radioactive gas.

Description

Technical Field

[0001] The present invention relates to the technical field of gas detection, and in particular to a gas detection system. Background Art

[0002] The airborne radioactive effluents generated during the operation of nuclear facilities must be purified and released into the atmosphere through the chimney. The discharged airborne radioactive effluents need to be tested to ensure that the emission of waste gas will not pollute the environment and achieve sustainable development.

[0003] In the related art, the gas detection system detects airborne radioactive effluents through a detection unit. However, since the concentration of radioactive gas in the effluent is relatively low, it is easy to affect the detection accuracy of existing detection technologies and detection equipment. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a gas detection system that can improve the detection accuracy of the gas detection system for low-concentration radioactive gases.

[0005] According to the gas detection system of the embodiment of the present invention, the gas detection system is used to detect the target element in the gas to be detected, and the gas detection system includes an air intake unit, an impurity removal unit, a sampling unit and a detection unit;

[0006] The air outlet end of the air inlet unit is connected to the air inlet end of the impurity removal unit, the air outlet end of the impurity removal unit is connected to the air inlet end of the sampling unit, the air outlet end of the sampling unit is connected to the air inlet end of the detection unit, the impurity removal unit is used to filter impurities in the gas to be tested, the sampling unit is used to adsorb target elements from the gas to be tested, and desorb target elements, and the detection unit is used to detect target elements desorbed from the sampling unit.

[0007] The heat dissipation structure according to the embodiment of the present invention has at least the following beneficial effects:

[0008] By setting an impurity removal unit between the air intake unit and the sampling unit, the gas to be tested can be filtered by the impurity removal unit before entering the sampling unit, so as to prevent impurities in the gas to be tested from entering the sampling unit and affecting the sensitivity of subsequent detection by the detection unit. At the same time, the sampling unit only adsorbs the target elements in the gas to be tested. After the sampling unit completes the enrichment of the target elements, the detection unit is used to detect the target elements desorbed from the sampling unit. In this way, the detection accuracy of the gas detection system for low-concentration radioactive gases can be improved.

[0009] According to some embodiments of the present invention, the impurity removal unit includes an impurity removal pipe and an impurity removal material. The air inlet and air outlet of the impurity removal unit are arranged in the impurity removal pipe, and the impurity removal material is arranged in the impurity removal pipe. The impurity removal material is used to absorb at least one of moisture, nitrogen, oxygen and dust in the gas to be tested.

[0010] According to some embodiments of the present invention, the impurity removal tube is made of a transparent material, and the impurity removal material is a color-changing desiccant, anhydrous calcium chloride, pyrocatechol or anhydrous calcium sulfate.

[0011] According to some embodiments of the present invention, the sampling unit includes a sampling tube, an adsorption material and a first heating device. The air inlet and air outlet of the sampling unit are arranged in the sampling tube, the adsorption material is arranged in the sampling tube, and the first heating device is used to adjust the temperature of the adsorption material so that the adsorption material adsorbs the target element from the gas to be tested, or desorbs the target element.

[0012] According to some embodiments of the present invention, the adsorption material is a first porous medium material, and the first porous medium material includes at least one of MOFs, COFs, activated carbon, molecular sieves and separation membrane materials.

[0013] According to some embodiments of the present invention, the gas detection system further comprises a separation unit, wherein the gas inlet end of the separation unit is connected to the gas outlet end of the sampling unit, and the gas outlet end of the separation unit is connected to the gas inlet end of the detection unit;

[0014] The separation unit is used to absorb at least one set element from the multiple target elements flowing out of the sampling unit, and the detection unit is used to detect target elements other than the set element;

[0015] And, the separation unit is used to desorb the set element, and the detection unit is used to detect the set element.

[0016] According to some embodiments of the present invention, the separation unit includes a separation tube, a separation material and a second heating device. The air inlet and air outlet of the separation unit are arranged in the separation tube, and the separation material is arranged in the separation tube. The second heating device is used to adjust the temperature of the separation material so that the separation material adsorbs at least one set element from the multiple target elements flowing out of the sampling unit, or desorbs the set element.

[0017] According to some embodiments of the present invention, the separation material is a second porous medium material, and the second porous medium material includes at least one of MOFs, COFs, activated carbon, molecular sieves and separation membranes.

[0018] According to some embodiments of the present invention, the gas detection system also includes a voltage stabilizing unit, wherein the air inlet end of the voltage stabilizing unit is connected to the air outlet end of the air inlet unit, and the air outlet end of the voltage stabilizing unit is connected to the air inlet end of the impurity removal unit, or the air inlet end of the voltage stabilizing unit is connected to the air outlet end of the impurity removal unit, and the air outlet end of the voltage stabilizing unit is connected to the air inlet end of the sampling unit, and the voltage stabilizing unit is used to cache and stabilize the gas to be tested.

[0019] According to some embodiments of the present invention, the gas detection system further comprises a monitoring unit, the gas inlet end of the monitoring unit is connected to the gas outlet end of the sampling unit, and the monitoring unit is used to monitor whether there is a target element in the gas to be tested flowing out of the sampling unit;

[0020] When the monitoring unit detects that the gas to be tested flowing out of the sampling unit contains the target element, the air intake unit is configured to stop air intake, the sampling unit is configured to desorb the target element, and the detection unit is configured to detect the target element desorbed from the sampling unit.

[0021] According to some embodiments of the present invention, the gas detection system further comprises a first gas driving unit, the first gas driving unit being arranged between the gas outlet end of the gas inlet unit and the gas inlet end of the sampling unit, the first gas driving unit being used to accelerate the gas flow;

[0022] And / or, the gas detection system further includes a second gas driving unit, the second gas driving unit is connected to the gas outlet end of the detection unit, and the second gas driving unit is used to accelerate the gas flow.

[0023] According to some embodiments of the present invention, the gas detection system further comprises a first gas filling unit, the gas outlet of the first gas filling unit is connected to the gas inlet unit, and the first gas filling unit is used to provide a carrier gas to the gas inlet unit to transport the gas to be tested;

[0024] And / or, the gas detection system further comprises a second gas filling unit, a gas outlet of the second gas filling unit is connected to a gas inlet of the sampling unit, and the second gas filling unit is used to provide activation gas to the sampling unit.

[0025] According to some embodiments of the present invention, the gas detection system further comprises a mounting plate, the mounting plate comprising at least two sub-plates, the impurity removal unit, the sampling unit and the detection unit being distributed on the at least two sub-plates;

[0026] Wherein, at least two sub-boards are spliced ​​to form a single-layer structure, or at least two sub-boards are stacked to form a stacked structure.

[0027] According to some embodiments of the present invention, the gas detection system further includes a transition tube, both ends of which extend to the two sub-boards respectively, and the transition tube is detachably connected to the impurity removal unit, sampling unit or detection unit on the two sub-boards.

[0028] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0030] Figure 1 A schematic diagram of a gas detection system provided by an embodiment of the present invention;

[0031] Figure 2 Another schematic diagram of a gas detection system provided by an embodiment of the present invention;

[0032] Figure 3 A three-dimensional diagram of a structure of a gas detection system provided by an embodiment of the present invention;

[0033] Figure 4 A three-dimensional diagram of another structure of a gas detection system provided by an embodiment of the present invention;

[0034] Figure 5 A three-dimensional diagram from another angle of another structure of the gas detection system provided by an embodiment of the present invention.

[0035] Reference numerals:

[0036] Gas detection system 1000;

[0037] Air intake unit 10;

[0038] Impurity removal unit 20; impurity removal pipe 21;

[0039] Sampling unit 30; sampling tube 31; first heating device 32; first heating element 321; first temperature control module 322;

[0040] Detection unit 40;

[0041] Voltage stabilizing unit 50;

[0042] Monitoring unit 60;

[0043] A first gas driving unit 70;

[0044] A second gas driving unit 80;

[0045] A first inflation unit 90;

[0046] A second inflation unit 100;

[0047] A third charging unit 110;

[0048] Separation unit 120; separation tube 121; second heating device 122; second heating element 1221; second temperature control module 1222;

[0049] Mounting plate 130; sub-plate 131;

[0050] Transition pipe 140;

[0051] Pressure sensor P;

[0052] The first flow meter F1; the second flow meter F2; the third flow meter F3; the fourth flow meter F4;

[0053] A first three-way valve TV1; a second three-way valve TV2; and a third three-way valve TV3. DETAILED DESCRIPTION

[0054] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0055] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0056] In the description of the present invention, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0057] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0058] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0059] See also Figure 1 An embodiment of the present invention provides a gas detection system 1000 for detecting a target element in a gas to be tested introduced from the discharged waste gas to obtain the content of the target element in the gas to be tested, thereby ensuring that the discharge of the waste gas will not pollute the environment and achieve sustainable development.

[0060] The gas detection system 1000 includes an air intake unit 10, an impurity removal unit 20, a sampling unit 30 and a detection unit 40. The air outlet of the air intake unit 10 is connected to the air intake of the impurity removal unit 20, the air outlet of the impurity removal unit 20 is connected to the air intake of the sampling unit 30, the air outlet of the sampling unit 30 is connected to the air intake of the detection unit 40, the impurity removal unit 20 is used to filter impurities in the gas to be tested, the sampling unit 30 is used to adsorb the target element from the gas to be tested, and desorb the target element, and the detection unit 40 is used to detect the target element desorbed from the sampling unit.

[0061] Specifically, the exhaust gas is introduced into the air inlet end of the air inlet unit 10, and the gas to be tested is filtered through the impurity removal unit 20 and then enters the sampling unit 30, and the sampling unit 30 adsorbs the target elements in the gas to be tested, so that the target elements in the gas to be tested are enriched in the sampling unit 30. After the sampling unit 30 completes the enrichment of the target elements in the gas to be tested, the target elements in the sampling unit 30 enter the detection unit 40 and are detected by the detection unit 40, so as to obtain the content of the target elements.

[0062] In an embodiment of the present invention, a de-impurity unit 20 is provided between the air intake unit 10 and the sampling unit 30, so that the gas to be tested can be filtered by the de-impurity unit 20 before entering the sampling unit 30, thereby preventing impurities in the gas to be tested from entering the sampling unit 30 and affecting the sensitivity of subsequent detection by the detection unit 40. At the same time, the sampling unit 30 only adsorbs the target elements in the gas to be tested. After the sampling unit 30 completes the enrichment of the target elements, the detection unit 40 is used to detect the target elements desorbed from the sampling unit 30. In this way, the detection accuracy of the gas detection system 1000 for low-concentration radioactive gases can be improved.

[0063] In some embodiments, the impurity removal unit 20 includes an impurity removal pipe 21 and an impurity removal material. The air inlet and air outlet of the impurity removal unit 20 are arranged in the impurity removal pipe 21. The impurity removal material is arranged in the impurity removal pipe 21. The impurity removal material is used to absorb at least one of moisture, nitrogen, oxygen and dust in the gas to be tested to prevent impurities from entering the sampling unit 30 with the gas to be tested and affecting the sensitivity of subsequent detection.

[0064] In some embodiments, the impurity removal tube 21 is made of transparent material. By making the impurity removal tube 21 transparent, the operator can observe the state changes of the impurity removal material inside the impurity removal tube 21 conveniently, so as to replace the impurity removal material in time or take out the impurity removal material, dry it and reload it for use.

[0065] The impurity removal materials are color-changing desiccant, anhydrous calcium chloride, caustic soda or anhydrous calcium sulfate.

[0066] The color-changing desiccant can effectively absorb impurities such as moisture and dust in the gas to be tested, ensuring that the gas to be tested entering the sampling unit 30 through the impurity removal tube 21 is dry and pure. The color-changing desiccant can change color according to the amount of moisture it absorbs. The operator can observe the color change of the color-changing desiccant in the impurity removal tube 21 through the impurity removal tube 21 to determine whether the color-changing desiccant has reached a saturated adsorption state. When the color-changing desiccant reaches a saturated adsorption state, the operator can remove the impurity removal tube 21 to replace the color-changing desiccant inside it or take out the color-changing desiccant inside it, dry it, and reload it for use.

[0067] Optionally, the color-changing desiccant can be silica gel drying particles. The silica gel drying particles are dark blue in the initial state (no moisture is absorbed). In the process of absorbing moisture in the gas to be tested, the silica gel particles gradually turn light blue. With the gradual adsorption of moisture, the silica gel particles change from light blue to red. When the silica gel particles turn pink or translucent red, it means that the silica gel particles have reached a saturated adsorption state.

[0068] Anhydrous calcium chloride, ergotamine and anhydrous calcium sulfate can effectively absorb impurities such as moisture in the gas to be tested. Anhydrous calcium chloride is a white or off-white solid in the initial state, which can be in the form of granules, blocks or powder; ergotamine is a white solid in the initial state, which can be in the form of flakes or blocks; anhydrous calcium sulfate is a white solid in the initial state, which can be powder or crystals. In the process of anhydrous calcium chloride adsorbing moisture in the gas to be tested, anhydrous calcium chloride gradually changes from solid to liquid. When anhydrous calcium chloride dissolves into liquid, it means that anhydrous calcium chloride has reached a saturated adsorption state, and the same is true for ergotamine and anhydrous calcium sulfate.

[0069] In some embodiments, the gas detection system 1000 also includes a first flow meter F1, which is arranged at the air inlet end or the air outlet end of the impurity removal unit 20. The first flow meter F1 is used to measure the air intake volume of the gas to be tested flowing out of the impurity removal unit 20. After the detection unit 40 completes the detection of the target element and obtains the content of the target element, the concentration of the target element in the gas to be tested can be calculated in combination with the air intake volume of the gas to be tested.

[0070] In some embodiments, the sampling unit 30 includes a sampling tube 31, an adsorbent material, and a first heating device 32. The gas inlet and gas outlet of the sampling unit 30 are arranged in the sampling tube 31. The adsorbent material is arranged in the sampling tube 31. The adsorbent material is used to adsorb the target element in the gas to be measured, or desorb the target element. The first heating device 32 is used to heat the adsorbent material to a first temperature or a second temperature. When the adsorbent material is heated to the first temperature, the adsorbent material is activated, thereby allowing the adsorbent material to adsorb the target element in the gas to be measured entering the sampling tube 31; when the adsorbent material is heated to the second temperature, the target element enriched on the adsorbent material can be desorbed from the adsorbent material, thereby allowing the target element to flow to the detection unit 40.

[0071] Specifically, the first heating device 32 includes a first heating element 321 and a first temperature control module 322. The first heating element 321 and the first temperature control module 322 are arranged on the outside of the sampling tube 31. The first temperature control module 322 is connected to the first heating element 321. The first temperature control module 322 is used to control the heating temperature of the first heating element 321 so that the adsorption material can be heated to the first temperature or the second temperature by the first heating element 321.

[0072] In some embodiments, the adsorption material is a first porous medium material, and the first porous medium material includes at least one of MOFs, COFs, activated carbon, molecular sieves, and separation membranes. MOFs, COFs, activated carbon, molecular sieves, and separation membranes all have a large number of pores, which provide extremely high specific surface areas and can provide a large number of adsorption sites for target elements. MOFs, COFs, activated carbon, molecular sieves, and separation membranes can adsorb and enrich target elements and filter out non-target elements.

[0073] Among them, MOFs and COFs can capture and fix target elements more effectively, with higher adsorption efficiency and stability, better selectivity, and will not be deactivated by the release of radioactivity from the gas to be tested.

[0074] The preparation of the adsorbent material is exemplified as follows: grind MOFs and / or COFs into uniform powder, take a certain amount of the powder and place it in a beaker, add an appropriate amount of methyl cellulose and deionized water, and stir continuously until a viscous paste is formed; then, transfer the paste to a molding device, extrude and mold, obtain spherical MOFs particles and / or COFs particles, place the spherical particles in a vacuum oven at 60°C and dry for a certain period of time, thereby obtaining a molding material of MOFs and / or COFs; finally, place the molding material into the sampling tube 31. In addition, if a molding material with a smaller particle size is required, the MOFs particles and / or COFs particles can be crushed and sieved to obtain a molding material of the corresponding size.

[0075] Since changes in the pressure of the gas to be tested will affect the density and flow characteristics of the gas, and thus affect the accuracy of subsequent detection results, therefore, in some embodiments, the gas detection system 1000 also includes a voltage stabilizing unit 50, and the air inlet end of the voltage stabilizing unit 50 is connected to the air outlet end of the air inlet unit 10, and the air outlet end of the voltage stabilizing unit 50 is connected to the air inlet end of the impurity removal unit 20, or, the air inlet end of the voltage stabilizing unit 50 is connected to the air outlet end of the impurity removal unit 20, and the air outlet end of the voltage stabilizing unit 50 is connected to the air inlet end of the sampling unit 30. The voltage stabilizing unit 50 is used to cache and stabilize the pressure of the gas to be tested. Before the gas to be tested passes through the voltage stabilizing unit 50 and enters the impurity removal unit 20 or the sampling unit 30, it can be cached in the voltage stabilizing unit 50 for a certain period of time (for example, 5 seconds), so that the pressure of the gas to be tested tends to be stable. In this embodiment, by setting a voltage stabilizing unit 50 to stabilize the pressure of the gas to be tested, the consistency of gas conditions in each measurement can be ensured, thereby improving the repeatability and reliability of the detection, and ensuring that the gas enters the subsequent pipeline at an appropriate pressure, avoiding insufficient gas flow due to too low pressure of the gas to be tested, avoiding affecting the sensitivity and accuracy of the detection, and ensuring the detection effect.

[0076] In some embodiments, the gas detection system 1000 further includes a pressure sensor P, which is connected to the voltage stabilizing unit 50, and the pressure sensor P is used to detect the pressure of the gas to be tested in the voltage stabilizing unit 50. Before the gas to be tested in the voltage stabilizing unit 50 flows from its gas outlet to the impurity removal unit 20 or the sampling unit 30, the connection between the voltage stabilizing unit 50 and the impurity removal unit 20 or the sampling unit 30 is disconnected. When the pressure value displayed by the pressure sensor P is stable, it indicates that the gas to be tested in the voltage stabilizing unit 50 has been stabilized. At this time, the voltage stabilizing unit 50 and the impurity removal unit 20 or the sampling unit 30 can be connected to allow the gas to be tested in the voltage stabilizing unit 50 to flow from its gas outlet to the impurity removal unit 20 or the sampling unit 30.

[0077] In some embodiments, the gas detection system 1000 further includes a monitoring unit 60, the air inlet end of the monitoring unit 60 is connected to the air outlet end of the sampling unit 30, and the monitoring unit 60 is used to monitor whether there is a target element in the gas to be tested flowing out of the sampling unit 30. When the monitoring unit 40 detects that there is a target element in the gas to be tested flowing out of the sampling unit 30, it indicates that the sampling unit 30 has completed the adsorption and enrichment of the target element in the gas to be tested, the air intake unit 10 is configured to stop air intake, the sampling unit 30 is configured to desorb the target element, and the detection unit 40 is configured to detect the target element desorbed from the sampling unit 30.

[0078] During the process of the sampling unit 30 adsorbing the inflowing gas to be tested, the gas outlet end of the sampling unit 30 is connected to the gas inlet end of the monitoring unit 60. At the beginning, all the target elements in the gas to be tested will be adsorbed by the sampling unit 30, and there is no target element in the gas flowing from the sampling unit 30 to the monitoring unit 60, and the monitoring unit 60 will not monitor the target element, which means that the adsorption of the target element by the sampling unit 30 has not reached the saturation state; after the gas to be tested has been passed in for a period of time, the target element that can be adsorbed in the sampling unit 30 has reached the maximum amount, and the sampling unit 30 will not continue to adsorb the target element. The target element appears in the gas flowing from the sampling unit 30 to the monitoring unit 60, and the monitoring unit 60 monitors the target element, which means that the sampling unit 30 has completed the adsorption and enrichment of the target element in the gas to be tested, which means that the adsorption of the target element by the sampling unit 30 has reached the saturation state. At this time, the intake of the intake unit 10 can be stopped.

[0079] In some embodiments, the monitoring unit 60 may be a liquid scintillation counter, a high purity germanium gamma spectrometer, or the like.

[0080] In some embodiments, the gas detection system 1000 further includes a second flow meter F2 , which is disposed at the air inlet end of the monitoring unit 60 , and is used to measure the air volume of the gas to be tested flowing from the sampling unit 30 into the monitoring unit 60 .

[0081] In some embodiments, the gas detection system 1000 also includes a first gas driving unit 70, which is disposed between the gas outlet end of the gas intake unit 10 and the gas intake end of the sampling unit 30. The first gas driving unit 70 is used to accelerate the gas flow so that the gas to be tested can flow smoothly in the pipeline of the gas monitoring system to avoid being unable to flow to the next link due to a small gas flow rate.

[0082] In some embodiments, the gas detection system 1000 further includes a second gas driving unit 80. The second gas driving unit 80 is connected to the gas outlet of the detection unit 40, and the second gas driving unit 80 is used to accelerate the gas flow so that the gas to be tested can flow smoothly in the pipeline of the gas monitoring system to avoid being unable to flow to the next link due to a small gas flow rate.

[0083] In some embodiments, the first gas driving unit 70 is disposed between the gas outlet of the voltage stabilizing unit 50 and the gas inlet of the sampling unit 30; the second gas driving unit 80 is disposed between the gas outlet of the sampling unit 30 and the gas inlet of the detection unit 40, and the second gas driving unit 80, the gas outlet of the sampling unit 30 and the gas inlet of the monitoring unit 60 are connected through the first three-way valve TV1. The gas inlet and gas outlet of the detection unit 40 may share the same port, that is, the gas inlet and gas outlet of the detection unit 40 realize gas intake and gas outlet through the same port.

[0084] In some embodiments, the first gas driving unit 70 and the second gas driving unit 80 are vacuum pumps.

[0085] In some embodiments, the gas detection system 1000 further includes a first gas charging unit 90, the outlet of the first gas charging unit 90 is connected to the gas inlet unit 10, and the first gas charging unit 90 is used to provide a carrier gas to the gas inlet unit 10 to transport the gas to be tested, so as to avoid the gas to be tested from being unable to flow to the next link due to the small volume. The outlet of the gas inlet unit 10, the inlet of the impurity removal unit 20 and the outlet of the first gas charging unit 90 are connected through a second three-way valve TV2.

[0086] In some embodiments, the carrier gas is an inert gas, which may be nitrogen, argon, or the like.

[0087] In some embodiments, the gas detection system 1000 further includes a second gas filling unit 100, the gas outlet of the second gas filling unit 100 is connected to the gas inlet of the sampling unit 30, and the second gas filling unit 100 is used to provide activation gas to the sampling unit 30 to restore or activate the adsorption sites on the adsorption material to make them in the best state, thereby improving the adsorption efficiency of the target nuclear element. The gas inlet of the sampling unit 30, the gas outlet of the voltage stabilizing unit 50 and the gas outlet of the second gas filling unit 100 are connected through a third three-way valve TV3.

[0088] In some embodiments, the gas detection system 1000 further includes a third flow meter F3 disposed at the gas outlet of the second gas filling unit 100 , and the third flow meter F3 is used to measure the amount of activated gas flowing from the second gas filling unit 100 into the sampling unit 30 .

[0089] In some embodiments, the gas detection system 1000 also includes a third filling unit 110, the gas outlet end of the third filling unit 110 is connected to the detection unit 40, and the third filling unit 110 is used to provide working gas to the detection unit 40. The working gas can be ionized by incident radioactive particles (such as α particles, β particles, γ rays, etc.) in the detection unit 40 to generate free electrons and positive ions. These charged particles move under the action of the electric field to form current pulses, which are detected by the detection unit 40.

[0090] In some embodiments, the gas detection system 1000 further includes a fourth flow meter F4 disposed at the gas outlet of the third gas filling unit 110 , and the fourth flow meter F4 is used to measure the amount of activated gas flowing from the second gas filling unit 100 into the sampling unit 30 .

[0091] When there are more than two target elements in the gas to be measured, if the content of the set element needs to be measured separately, the target elements need to be separated. Therefore, in some embodiments, the gas detection system 1000 further includes a separation unit 120, the air inlet end of the separation unit 120 is connected to the air outlet end of the sampling unit 30, and the air outlet end of the separation unit 120 is connected to the air inlet end of the detection unit 40. The separation unit 120 is used to adsorb at least one set element from the multiple target elements flowing out of the sampling unit 30, and the detection unit 40 is used to detect the target elements other than the set elements, and the separation unit 30 is used to desorb the set elements, and the detection unit 40 is used to detect the set elements.

[0092] Specifically, in the process of separating the set elements, the connection between the sampling unit 30 and the separation unit 120 is first disconnected. After the gas to be tested enters the sampling unit 30, the sampling unit 30 adsorbs and enriches all the target elements; after the sampling unit 30 completes the enrichment of all the target elements, the sampling unit 30 and the separation unit 120 are connected, and all the target elements in the sampling unit 30 are desorbed from the sampling unit 30 and flow to the separation unit 120. At this time, the separation unit 120 can adsorb and enrich the set elements, and the target elements other than the set elements enter the detection unit 40 through the separation unit 120 and are detected by the detection unit 40. In this process, the separation unit 120 separates the target elements flowing out of the sampling unit 30; when the detection unit 40 completes the detection of the target elements other than the set elements, the set elements in the separation unit 120 are desorbed from the separation unit 120 and enter the detection unit 40 and are detected by the detection unit 40.

[0093] See also Figure 2In some embodiments, the separation unit 120 includes a separation tube 121, a separation material, and a second heating device 122. The air inlet and air outlet of the separation unit 120 are arranged on the separation tube 31. The separation material is arranged in the separation tube 121. The second heating device 122 is used to adjust the temperature of the separation material so that the separation material adsorbs at least one set element from the multiple target elements flowing out of the sampling unit 30, or desorbs the set element. The second heating device 122 is used to heat the separation material to a third temperature or a fourth temperature. When the separation material is heated to the third temperature, the separation material is activated, thereby allowing the separation material to adsorb a certain target element entering the separation tube 121; when the adsorbent material is heated to the fourth temperature, a certain target element enriched on the separation material can be desorbed from the separation material, thereby allowing the certain target element to flow to the detection unit 40.

[0094] Specifically, the second heating device 122 includes a second heating element 1221 and a second temperature control module 1222. The second heating element 1221 and the second temperature control module 1222 are arranged on the outside of the separation tube 121. The second temperature control module 1222 is connected to the second heating element 1221. The second temperature control module 1222 is used to control the heating temperature of the second heating element 1221 so that the separation material can be heated to the third temperature or the fourth temperature by the second heating element 1221.

[0095] In some embodiments, the separation material is a second porous medium material, and the second porous medium material includes at least one of MOFs, COFs, activated carbon, molecular sieves, and separation membranes. MOFs, COFs, activated carbon, molecular sieves, and separation membranes all have a large number of pores, which provide extremely high specific surface areas and can provide a large number of adsorption sites for target elements. MOFs, COFs, activated carbon, molecular sieves, and separation membranes can adsorb and enrich target elements and filter out non-target elements.

[0096] The first three-way valve TV1 connects the gas outlet of the sampling unit 30 , the gas inlet of the monitoring unit 60 , and the gas inlet of the separation unit 120 .

[0097] See also Figure 3 In some embodiments, the gas detection system 1000 also includes a mounting plate 130, and the mounting plate 130 includes at least two sub-plates 131. The impurity removal unit 20, the sampling unit 30 and the detection unit 40 are distributed on at least two sub-plates 131. In this way, each sub-plate 131 can carry and fix the corresponding unit, allowing each sub-plate 131 and the unit arranged thereon to be modularized, that is, a sub-plate 131 and the corresponding unit form a module. In this way, modular disassembly and assembly can be realized, which is convenient for packaging and transportation.

[0098] like Figure 3As shown, at least two sub-boards 131 are spliced ​​to form a single-layer structure, so that the mounting board 130 and the units arranged on the mounting board 130 can be laid out flat, reducing the space occupied in the direction perpendicular to the surface of the sub-board 131; or Figure 4 and Figure 5 As shown, at least two sub-boards 131 are stacked to form a stacked structure, so that the mounting board 130 and the units arranged on the mounting board 130 can be stacked, reducing the space occupied in the direction parallel to the surface of the sub-board 131.

[0099] In some embodiments, the gas detection system 1000 also includes a transition tube 140, both ends of which extend to the two sub-boards 131 respectively. The transition tube 140 can be detachably connected to the impurity removal unit 20, the sampling unit 30 or the detection unit 40 on the two sub-boards 131 to achieve pipeline connection between the impurity removal units 20, the sampling units 30 and the detection units 40 on different sub-boards 131, that is, the units arranged on different sub-boards 131 can be connected by pipeline through the transition tube 140.

[0100] In some embodiments, there are two sub-boards 131, one side of one sub-board 131 is connected to the other side of the other sub-board 131 to form a single-layer structure, or two sub-boards 131 are stacked to form a double-layer structure. The impurity removal unit 20, the detection unit 40 and the second gas drive unit 80 are installed on one of the sub-boards 131, and the impurity removal unit 20, the detection unit 40 and the second gas drive unit 80 form a module with one of the sub-boards 131, and the sampling unit 30, the voltage stabilizing unit 50 and the first gas drive unit 70 are installed on the other sub-board 131, and the sampling unit 30, the voltage stabilizing unit 50 and the first gas drive unit 70 form another module with the other sub-board 131.

[0101] The impurity removal unit 20 and the voltage stabilizing unit 50 are connected by a transition tube 140, and the transition tube 140 is detachably connected between the impurity removal unit 20 and the voltage stabilizing unit 50, so that the pipeline between the impurity removal unit 20 and the voltage stabilizing unit 50 can be quickly disassembled and assembled, so that the impurity removal unit 20 and the voltage stabilizing unit 50 can be connected or separated. The sampling unit 30 and the second gas drive unit 80 are connected by a transition tube 140, and the transition tube 140 is detachably connected between the sampling unit 30 and the second gas drive unit 80, so that the pipeline between the sampling unit 30 and the second gas drive unit 80 can be quickly disassembled and assembled, so that the sampling unit 30 and the second gas drive unit 80 can be connected or separated. Through the above arrangement, the mounting plate 130 and each unit arranged on the mounting plate 130 can be easily disassembled to form two modules, thereby facilitating packaging and transportation.

[0102] The transition pipe 140 may be directly connected to the corresponding unit, or may be indirectly connected to the corresponding unit through a corresponding flow meter or valve, for example. Figure 4 and Figure 5 As shown, a transition pipe 140 is provided between the impurity removal unit 20 and the pressure stabilizing unit 50, and both ends of the transition pipe 140 extend to two sub-plates 131 respectively. One end of the transition pipe 140 is indirectly connected to the impurity removal unit 20 via a first flow meter F1, and the other end of the transition pipe 140 is directly connected to the pressure stabilizing unit 50; the transition pipe 140 can be a pipeline, or a combination of a quick connector and a pipeline.

[0103] In addition, the air intake unit 10, the monitoring unit 60, the first air charging unit 90, the second air charging unit 100 and the third air charging unit 110 are all arranged on the outside of the mounting plate 130. Of course, the air intake unit 10, the monitoring unit 60, the first air charging unit 90, the second air charging unit 100 and / or the third air charging unit 110 can also be installed on the sub-plate 131 as needed.

[0104] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A gas detection system for detecting target elements in a gas to be detected, characterized in that: It includes an air intake unit, a dust removal unit, a sampling unit and a detection unit; The air outlet end of the air inlet unit is connected to the air inlet end of the impurity removal unit, the air outlet end of the impurity removal unit is connected to the air inlet end of the sampling unit, the air outlet end of the sampling unit is connected to the air inlet end of the detection unit, the impurity removal unit is used to filter impurities in the gas to be tested, the sampling unit is used to adsorb target elements from the gas to be tested, and desorb the target elements, and the detection unit is used to detect the target elements desorbed from the sampling unit.

2. The gas detection system according to claim 1, characterized in that: The impurity removal unit includes an impurity removal pipe and an impurity removal material. The air inlet end and the air outlet end of the impurity removal unit are arranged in the impurity removal pipe. The impurity removal material is arranged in the impurity removal pipe. The impurity removal material is used to absorb at least one of moisture, nitrogen, oxygen and dust in the gas to be tested.

3. The gas detection system according to claim 2, characterized in that: The impurity removal tube is made of transparent material, and the impurity removal material is a color-changing desiccant, anhydrous calcium chloride, caustic soda or anhydrous calcium sulfate.

4. The gas detection system according to claim 1, characterized in that: The sampling unit includes a sampling tube, an adsorption material and a first heating device. The air inlet end and the air outlet end of the sampling unit are arranged on the sampling tube, and the adsorption material is arranged in the sampling tube. The first heating device is used to adjust the temperature of the adsorption material so that the adsorption material adsorbs the target element from the gas to be measured, or desorbs the target element.

5. The gas detection system according to claim 4, characterized in that: The adsorption material is a first porous medium material, and the first porous medium material includes at least one of MOFs, COFs, activated carbon, molecular sieves and separation membranes.

6. The gas detection system according to claim 1, characterized in that: The gas detection system further comprises a separation unit, wherein the air inlet end of the separation unit is connected to the air outlet end of the sampling unit, and the air outlet end of the separation unit is connected to the air inlet end of the detection unit; Wherein, the separation unit is used to adsorb at least one set element from the multiple target elements flowing out of the sampling unit, and the detection unit is used to detect the target elements other than the set element; Furthermore, the separation unit is used to desorb the set element, and the detection unit is used to detect the set element.

7. The gas detection system according to claim 6, characterized in that: The separation unit includes a separation tube, a separation material and a second heating device. The air inlet end and the air outlet end of the separation unit are arranged in the separation tube. The separation material is arranged in the separation tube. The second heating device is used to adjust the temperature of the separation material so that the separation material adsorbs at least one set element from the multiple target elements flowing out of the sampling unit, or desorbs the set element.

8. The gas detection system according to claim 6, characterized in that: The separation material is a second porous medium material, and the second porous medium material includes at least one of MOFs, COFs, activated carbon, molecular sieves and separation membranes.

9. The gas detection system according to claim 1, characterized in that: The gas detection system also includes a voltage stabilizing unit, the air inlet end of the voltage stabilizing unit is connected to the air outlet end of the air inlet unit, and the air outlet end of the voltage stabilizing unit is connected to the air inlet end of the impurity removal unit, or the air inlet end of the voltage stabilizing unit is connected to the air outlet end of the impurity removal unit, and the air outlet end of the voltage stabilizing unit is connected to the air inlet end of the sampling unit, and the voltage stabilizing unit is used to buffer and stabilize the gas to be tested.

10. The gas detection system according to claim 1, characterized in that: The gas detection system further comprises a monitoring unit, the gas inlet end of the monitoring unit is connected to the gas outlet end of the sampling unit, and the monitoring unit is used to monitor whether there is a target element in the gas to be tested flowing out of the sampling unit; Wherein, when the monitoring unit detects the presence of target elements in the gas to be tested flowing out of the sampling unit, the air intake unit is configured to stop air intake, the sampling unit is configured to desorb the target elements, and the detection unit is configured to detect the target elements desorbed from the sampling unit.

11. The gas detection system according to claim 1, characterized in that: The gas detection system further comprises a first gas driving unit, which is arranged between the gas outlet end of the gas inlet unit and the gas inlet end of the sampling unit, and is used to accelerate the gas flow; And / or, the gas detection system further comprises a second gas driving unit, the second gas driving unit is connected to a gas outlet end of the detection unit, and the second gas driving unit is used to accelerate gas flow.

12. The gas detection system according to claim 1, characterized in that: The gas detection system further comprises a first gas charging unit, the gas outlet of the first gas charging unit is connected to the gas inlet unit, and the first gas charging unit is used to provide a carrier gas to the gas inlet unit to transport the gas to be tested; And / or, the gas detection system further comprises a second gas filling unit, a gas outlet of the second gas filling unit is connected to a gas inlet of the sampling unit, and the second gas filling unit is used to provide activation gas to the sampling unit.

13. The gas detection system according to claim 1, characterized in that: The gas detection system further comprises a mounting plate, wherein the mounting plate comprises at least two sub-plates, and the impurity removal unit, the sampling unit and the detection unit are distributed on at least two of the sub-plates; Wherein, at least two of the sub-boards are spliced ​​to form a single-layer structure, or at least two of the sub-boards are stacked to form a stacked structure.

14. The gas detection system according to claim 13, characterized in that: The gas detection system further comprises a transition pipe, both ends of which extend to the two sub-boards respectively, and the transition pipe is detachably connected to the impurity removal unit, the sampling unit or the detection unit on the two sub-boards.

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