Nitrogen oxide sampling device and method

Abstract

The invention provides a nitrogen oxide sampling device and method. The device comprises a controller, an absorption liquid storage device and an absorption bottle, the controller receives a collection instruction sent by a user, and the controller controls a first path to be opened when first sampling time corresponding to the collection instruction is reached; the controller is used for injecting the absorption liquid with preset metering in the absorption liquid storage device into the absorption bottle through the first passage; the controller controls the air inlet of the main body to be in an open state, so that atmosphere enters the absorption bottle from the air inlet; and the absorption bottle captures nitrogen oxides in the atmosphere by using the absorption liquid to obtain a sample. The absorption liquid is automatically injected when the first sampling time corresponding to the collection instruction is reached, NOx in the atmosphere is collected through the absorption liquid, the sample is obtained, and the sample obtained at the moment can meet subsequent isotope analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of air pollution prevention and control, and particularly to a sampling device and method for nitrogen oxides. Background Art

[0002] Nitrogen oxides NOx are the main components of atmospheric reactive nitrogen, which will cause a series of chemical or photochemical reactions in the atmosphere, resulting in air pollution and harming the natural environment and human health.

[0003] Existing NOx sampling techniques include active sampling and passive sampling techniques. The active sampling technique uses a vacuum pump as the power to actively extract NOx in the atmosphere and capture it with an oxidizing absorption liquid, which is mostly used for short-term monitoring. The passive sampling technique uses a microporous filter membrane coated with an absorption liquid, and NOx in the atmosphere diffuses through the microporous filter membrane and is captured by the absorption liquid, which is mostly used for long-term monitoring.

[0004] Since NOx collection in the past was mostly used for concentration analysis and did not consider subsequent isotope analysis, the sample may not be suitable for isotope characteristic analysis or there is doubt whether the original isotope characteristics are completely retained. Therefore, the types of NOx absorption liquids need to be improved to meet isotope analysis requirements. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a sampling device and method for nitrogen oxides to solve the problem that the collected NOx absorption liquid in existing research cannot meet isotope analysis requirements.

[0006] To achieve the above object, embodiments of the present invention provide the following technical solutions:

[0007] A first aspect of an embodiment of the present invention shows a sampling device for nitrogen oxides, the device comprising: a controller, an absorption liquid reservoir, and an absorption bottle;

[0008] The absorption liquid reservoir and the absorption bottle are arranged in the main body; the controller is wirelessly connected to the absorption liquid reservoir and the absorption bottle respectively;

[0009] An air inlet for collecting the atmosphere is arranged on the main body;

[0010] The controller receives a collection instruction sent by the user, and when reaching the first sampling time corresponding to the collection instruction, controls the first passage to open;

[0011] The controller injects a pre-designed amount of absorption liquid from the absorption liquid reservoir into the absorption bottle through the first passage;

[0012] The controller controls the air inlet of the main body to be in an open state, so that the atmosphere enters the absorption bottle from the air inlet;

[0013] The absorption bottle uses the absorption liquid to capture the nitrogen oxides in the atmosphere to obtain a sample.

[0014] Optionally, it further includes: a first solenoid valve and a first micro-injection pump;

[0015] The first solenoid valve is respectively connected to the absorption bottle and the first micro-injection pump;

[0016] The first micro-injection pump is connected to the absorption liquid reservoir;

[0017] Wherein, when the first sampling time is reached, the controller controls the opening of the first passage, specifically for:

[0018] When the first sampling time is reached, the controller controls the first solenoid valve in the main body to switch to the first passage where the first micro-injection pump is located. The first passage includes the first micro-injection pump, the first solenoid valve, and the absorption liquid reservoir;

[0019] Correspondingly, the controller injects a pre-measured amount of absorption liquid in the absorption liquid reservoir into the absorption bottle through the first passage, specifically for:

[0020] The controller controls the first micro-injection pump to start, so that the first micro-injection pump extracts a pre-measured amount of absorption liquid from the absorption liquid reservoir and injects it into the absorption bottle.

[0021] Optionally, it further includes: a filter membrane clamp;

[0022] A microporous filter membrane and a nylon filter membrane are arranged in the filter membrane clamp;

[0023] The filter membrane clamp is arranged at the air inlet and is connected to the absorption bottle;

[0024] The atmosphere enters the filter membrane clamp from the air inlet and is filtered by the microporous filter membrane and the nylon filter membrane.

[0025] Optionally, it further includes: a vacuum pump;

[0026] The vacuum pump is connected to the absorption bottle;

[0027] The controller controls the vacuum pump to start, so that the air inlet of the main body is in an open state.

[0028] Optionally, it further includes: a second solenoid valve, a sample bottle, and a second micro-injection pump;

[0029] One end of the second solenoid valve is connected to a plurality of sample bottles, and the other end is connected to the absorption bottle through the second micro-injection pump;

[0030] When the controller reaches the second sampling time corresponding to the collection instruction, it controls the vacuum pump to close; based on the second solenoid valve, it controls the opening of the second passage, where the second passage consists of a second solenoid valve, a sample bottle, and a second micro-injection pump;

[0031] The controller controls the second micro-injection pump to start, so that the second micro-injection pump extracts the sample in the absorption bottle and injects it into the sample bottle.

[0032] Optionally, it further includes: a waste liquid bottle;

[0033] The waste liquid bottle is connected to the second solenoid valve, and a third passage is constructed based on the second solenoid valve and the waste liquid bottle;

[0034] When the controller detects that the sample extraction is completed, it controls the second micro-injection pump to close, and the second solenoid valve switches to the third passage connected to the waste liquid bottle.

[0035] Optionally, it further includes: a third micro-injection pump and a solution reservoir;

[0036] The first solenoid valve is connected to the solution reservoir through the third micro-injection pump;

[0037] When the controller determines that the second solenoid valve switches to the third passage connected to the waste liquid bottle, it controls the first solenoid valve to switch to the fourth passage connected to the third micro-injection pump, and controls the third micro-injection pump to start, so that the third micro-injection pump extracts a second measurement of a preset solution from the solution reservoir and injects it into the absorption bottle to clean the absorption bottle;

[0038] The controller controls the third micro-injection pump to close, disconnects the first solenoid valve, and starts the second micro-injection pump; so that the second micro-injection pump extracts the waste liquid after cleaning in the absorption bottle and injects it into the waste liquid bottle through the second solenoid valve.

[0039] Optionally, the absorption liquid reservoir, the waste liquid bottle, and the solution reservoir are all arranged in the storage room of the main body.

[0040] Optionally, it further includes: a radiator and a heater for temperature control according to the ambient temperature.

[0041] The second aspect of the embodiments of the present invention shows a sampling method for nitrogen oxides, which is applied to the nitrogen oxide sampling device according to any one of the first aspects of the embodiments of the present invention. The device includes: a controller, an absorption liquid reservoir, and an absorption bottle; the method includes:

[0042] The controller receives a collection instruction sent by a user. When the first sampling time corresponding to the collection instruction is reached, the controller controls the opening of the first passageway.

[0043] The controller injects a pre-measured amount of the absorption liquid in the absorption liquid reservoir into the absorption bottle through the first passageway.

[0044] The controller controls the air inlet of the main body to be in an open state, so that the atmosphere enters the absorption bottle from the air inlet.

[0045] The absorption bottle uses the absorption liquid to capture the nitrogen oxides in the atmosphere to obtain a sample.

[0046] Based on the sampling device and method for nitrogen oxides provided in the above embodiments of the present invention, the device includes: a controller, an absorption liquid reservoir, and an absorption bottle; the absorption liquid reservoir and the absorption bottle are arranged in the main body; the controller is wirelessly connected to the absorption liquid reservoir and the absorption bottle respectively; an air inlet for collecting the atmosphere is arranged on the main body; the controller receives a collection instruction sent by a user. When the first sampling time corresponding to the collection instruction is reached, the controller controls the opening of the first passageway; the controller injects a pre-measured amount of the absorption liquid in the absorption liquid reservoir into the absorption bottle through the first passageway; the controller controls the air inlet of the main body to be in an open state, so that the atmosphere enters the absorption bottle from the air inlet; the absorption bottle uses the absorption liquid to capture the nitrogen oxides in the atmosphere to obtain a sample. The present invention automatically fills the absorption liquid when the first sampling time corresponding to the collection instruction is reached, so as to collect NOx in the atmosphere through the absorption liquid and obtain a sample that can be reserved for isotope characteristic analysis or the original isotope characteristic. The sample obtained at this time can meet the subsequent isotope analysis. Description of the Drawings

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0048] Figure 1 It is a schematic structural diagram of a sampling device for nitrogen oxides shown in the embodiments of the present invention.

[0049] Figure 2 It is a schematic flowchart of a sampling method for nitrogen oxides shown in the embodiments of the present invention. Detailed Embodiments

[0050] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0051] The terms "first", "second", "third", "fourth", etc. (if any) in the specification, claims and above-mentioned drawings of this application are used to distinguish similar objects and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments described here can be implemented in an order different from that shown or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0052] It should be noted that the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0053] In this application, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such a process, method, article or device. Without further limitations, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the said element.

[0054] See Figure 1 , a sampling device for nitrogen oxides shown in the embodiments of the present invention, the device includes: a controller (not shown in the figure), an absorption liquid reservoir 10, and an absorption bottle 20;

[0055] The absorption liquid reservoir 10 and the absorption bottle 20 are arranged in the main body 1; the controller is wirelessly connected to the absorption liquid reservoir 10 and the absorption bottle 20 respectively;

[0056] An air inlet for collecting the atmosphere is arranged on the main body 1;

[0057] Specifically, the absorption liquid reservoir 10 and the absorption bottle 20 can be arranged in one main body 1, and the controller can be wirelessly connected to the absorption liquid reservoir 10 and the absorption bottle 20 in multiple main bodies;

[0058] Optionally, the nozzle of the absorption bottle 20 is spherical, and is evenly provided with circular micropores with a diameter of 1 mm, which can make the gas fully contact with the absorption liquid, ensure the absorption efficiency, and effectively prevent blockage.

[0059] Among them, the absorption bottle 20 is made of high borosilicate glass.

[0060] The absorption liquid reservoir 10 can be a NOx absorption liquid bottle, and the prepared NOx absorption liquid is stored in the absorption liquid reservoir 10.

[0061] It should be noted that the absorption liquid is an absorption liquid composed of 0.25 mol / L potassium permanganate (KMnO4) and 0.5 mol / L sodium hydroxide (NaOH).

[0062] The controller receives the collection instruction sent by the user; when it is determined that the first sampling time corresponding to the collection instruction is reached, the first passage is controlled to be opened; the controller injects a pre-designed amount of absorption liquid in the absorption liquid reservoir 10 into the absorption bottle 20 through the first passage; the controller controls the air inlet of the main body to be in an open state so that the atmosphere enters the absorption bottle 20 from the air inlet;

[0063] The absorption bottle 20 captures the nitrogen oxides in the atmosphere with the absorption liquid to obtain a sample.

[0064] Specifically, NOx in the atmosphere is oxidized to nitrate ions (NO3-) after passing through the absorption liquid, and NOx is stored in the absorption bottle 20. In the range of a flow rate of 1-3 L / min, the absorption efficiency of this method for atmospheric NOx is 100%.

[0065] Among them, hydrogen peroxide is added to the absorption liquid to remove the excessive KMnO4, and then hydrochloric acid is added to neutralize it. At this time, the sample mainly contains NaCl and NaNO3, which can meet the subsequent isotope analysis.

[0066] Optionally, the user can upload the corresponding collection instruction through the controller, and the collection instruction includes the sampling start time of all the collected gases this time, the first sampling time, the second sampling time, and the sampling flow rate, etc.

[0067] It should be noted that the first sampling time is determined based on the sampling start time and can generally be set within 5 minutes after the sampling time; the second sampling time is determined through multiple experiments based on the sampling start time and the sampling flow rate to obtain the total time required for sampling, and the second sampling time is set based on the total time required for sampling, and can generally be set 10 minutes before the end of the total time required for sampling.

[0068] The controller receives the collection instruction and determines to start sampling processing when the current time reaches the sampling start time; when the controller determines that the corresponding first sampling time has been reached, it controls the first passage to open.

[0069] Optionally, before sampling, it is necessary to first check whether the gas pipeline and the liquid pipeline in the nitrogen oxide sampling device are correctly connected.

[0070] Specifically, first, the absorption bottle 20 and the sampling bottle are separately cleaned with ultrapure water and dried; then the absorption bottle 20 and the sampling bottle are respectively installed in the main body 1; then, check whether the connection sequence between different components is correct, such as whether the inlet and outlet directions of the pump and the valve are reversed. If both are correct, it is determined that the gas pipeline and the liquid pipeline are correctly connected.

[0071] Optionally, it further includes:

[0072] The controller starts the automatic airtightness inspection program of the gas path to control the electronic flowmeter and the vacuum pump in the main body 1 to start, and at the same time controls the air inlet to be in a closed state, and obtains the displayed flow rate of the electronic flowmeter. If the final displayed flow rate is 0 L / min, it indicates that the pipeline airtightness is good.

[0073] Continue to refer to Figure 1 , based on the device shown in the above embodiments of the present invention, the nitrogen oxide sampling device further includes: a first electromagnetic valve 31 and a first micro-injection pump 41;

[0074] The first electromagnetic valve 31 is respectively connected to the absorption bottle 20 and the first micro-injection pump 41;

[0075] The first micro-injection pump 41 is connected to the absorbent reservoir 10;

[0076] Specifically, the first electromagnetic valve 31 and the first micro-injection pump 41 are also arranged in the main body 1. The first electromagnetic valve 31 is arranged on the liquid pipeline and is respectively connected to the first port of the absorption bottle 20 and the first micro-injection pump 41 through this liquid pipeline. The first micro-injection pump 41 is connected to the absorbent reservoir 10 through a liquid pipeline.

[0077] Among them, when the controller reaches the first sampling time, it controls the opening of the first passage, specifically for:

[0078] When the controller reaches the first sampling time, it controls the first solenoid valve in the main body to switch to the first passage where the first micro-injection pump is located.

[0079] Among them, the first passage includes the first micro-injection pump 41, the first solenoid valve 31, and the absorbent liquid reservoir 10. That is to say, the first passage refers to the pipeline connected by the first micro-injection pump 41, the first solenoid valve 31, and the absorbent liquid reservoir 10 as the first passage.

[0080] Specifically, the controller executes the NOx absorbent liquid filling program to control the first solenoid valve 31 to first switch to the first passage connected to the pipeline of the first micro-injection pump 41.

[0081] Correspondingly, the controller injects the pre-designed amount of absorbent liquid in the absorbent liquid reservoir 10 into the absorption bottle 20 through the first passage, specifically for:

[0082] The controller controls the first micro-injection pump 41 to start, so that the first micro-injection pump 41 extracts the pre-designed amount of absorbent liquid from the absorbent liquid reservoir 10 and injects it into the absorption bottle 20.

[0083] Specifically, the controller controls the first micro-injection pump 41 to start, and quantitatively extracts 50 mL of NOx absorbent liquid from the absorbent liquid reservoir 10 and injects it into the absorption bottle 20.

[0084] It should be noted that the pre-designed amount is set by technicians in advance according to the actual situation, and generally 50 mL can be quantitatively extracted.

[0085] Optionally, after the controller detects that the filling of the absorbent liquid fed back by the first micro-injection pump 41 is completed, it controls the first micro-injection pump 41 to close and the first solenoid valve 31 to disconnect.

[0086] Continue to refer to Figure 1 , based on the device shown in the above embodiments of the present invention, the nitrogen oxide sampling device further includes: a filter membrane clamp 50;

[0087] A microporous filter membrane 51 and a nylon filter membrane 52 are arranged in the filter membrane clamp 50;

[0088] Specifically, the microporous filter membrane 51 and the nylon filter membrane 52 are respectively installed in the filter membrane clamp 50 from top to bottom.

[0089] The filter membrane clamp 50 is arranged at the air inlet and is connected to the absorption bottle 20;

[0090] The atmosphere enters the filter membrane clamp 50 from the air inlet and is filtered through the microporous filter membrane 51 and the nylon filter membrane 52.

[0091] Specifically, the atmosphere, i.e., the sample gas, enters the filter membrane clamp 50 from the air inlet and passes through the microporous filter membrane 51 and the nylon filter membrane 52 to remove particulate nitrate and gaseous nitrate in the atmosphere respectively.

[0092] The filter membrane clamp 50 is made of Teflon. Multiple layers of filter membranes can be placed inside. The microporous filter membrane 51 and the nylon filter membrane 52 are placed from top to bottom respectively to remove particulate nitrate and gaseous nitrate respectively, so as to avoid affecting the sample.

[0093] Continue to refer to Figure 1 , based on the device shown in the above embodiments of the present invention, the sampling device for nitrogen oxides further includes: a vacuum pump 60;

[0094] The vacuum pump 60 is connected to the absorption bottle 20;

[0095] The controller controls the vacuum pump 60 to start, so that the air inlet of the main body 1 is in an open state.

[0096] Specifically, after the controller controls the first micro-injection pump 41 to close and the first solenoid valve 31 to disconnect, it controls the vacuum pump to start. At this time, the air inlet is in an open state, and at this time, the atmospheric NOx is collected.

[0097] Optionally, the device further includes: an electronic flowmeter 70 and a drying tube 80.

[0098] Specifically, the absorption bottle 20 is connected to the drying tube 80 through a gas pipeline. The drying tube 80 is connected to the electronic flowmeter 70 through a gas pipeline. The electronic flowmeter 70 is connected to the vacuum pump 60 through a gas pipeline. The vacuum pump 60 can output the atmosphere after collecting NOx through a gas pipeline.

[0099] Among them, the drying tube 80 is filled with silica gel desiccant to remove the water vapor carried out by the air flow in the atmosphere and avoid affecting the electronic flowmeter 70 and the vacuum pump 60.

[0100] The controller adjusts the electronic flowmeter 70 to be stable at a preset sampling flow rate of 1 L / min to control the gas flow rate collected.

[0101] Optionally, at the same time, the controller automatically records and stores the cumulative sampling volume of the electronic flowmeter 70 for subsequent concentration calculation.

[0102] Continue to refer to Figure 1 , based on the device shown in the above embodiments of the present invention, the sampling device for nitrogen oxides further includes: a second solenoid valve 32, a sample bottle 90, and a second micro-injection pump 42;

[0103] One end of the second solenoid valve 32 is connected to a plurality of sample bottles 90, and the other end is connected to the absorption bottle 20 through the second micro-injection pump 42.

[0104] Specifically, the second solenoid valve 32 and the plurality of sample bottles 90 are both arranged in the sample chamber 2 inside the main body 1. The second solenoid valve 32 is arranged on the liquid pipeline and is connected to the plurality of sample bottles 90 through the liquid pipeline; the other end is connected to the absorption bottle 20 through the second micro-injection pump 42 via the liquid pipeline.

[0105] It should be noted that the sample chamber 2 includes a refrigeration module. The controller controls the sample chamber 2 to be in a low-temperature state through the refrigeration module, and stores the sample through the sample chamber 2 in the low-temperature state. The temperature of the sample chamber 2 is maintained at 4 °C to reduce the isotope fractionation of the sample.

[0106] Among them, the sample bottle 90 is made of brown Teflon material, which is corrosion-resistant, has low adsorption, and no background pollution.

[0107] It should be noted that the plurality of sample bottles 90 are sample bottles sorted in ascending order of serial number. As Figure 1 shown, 6 sample bottles 90 are set, and the sample bottles 90 are numbered 1, 2, 3, 4, 5, and 6 respectively.

[0108] When the controller reaches the second sampling time corresponding to the collection instruction, it controls the vacuum pump 60 to close; based on the second solenoid valve 32, it controls the second passage to open, where the second passage is composed of the second solenoid valve 32, the sample bottle 90, and the second micro-injection pump 42;

[0109] The controller controls the second micro-injection pump 42 to open so that the second micro-injection pump 42 extracts the sample in the absorption bottle 20 and injects it into the sample bottle 90.

[0110] Specifically, the controller records the current time in real time. When the current time reaches the second sampling time corresponding to the collection instruction, the vacuum pump 60 closes, and at this time, the air inlet prevents the atmosphere from entering.

[0111] The controller first checks all the current sampling bottles 90, and determines the sampling bottles 90 that are not full and empty at present; finds the sample bottle 90 with the smallest serial number among the sampling bottles 90 that are not full and empty, and uses it as the target sampling bottle 90; controls the second solenoid valve 32 to switch to the passage connected to the current target sampling bottle 90, and controls the second micro-injection pump 42 to open;

[0112] The second micro-injection pump 42 extracts the sample in the absorption bottle 20 and injects it into the target sampling bottle 90.

[0113] If the controller detects that the target sampling bottle 90 is full, it first controls the second micro-injection pump 42 to close, and takes the serial number of the current target sampling bottle 90 + 1 as the next target sampling bottle 90; and controls the second solenoid valve 32 to switch to the passage connected to the next target sampling bottle 90, then controls the second micro-injection pump 42 to open, and repeats the above steps until all samples are extracted.

[0114] Continue to refer to Figure 1 , based on the device shown in the above embodiments of the present invention, the nitrogen oxide sampling device further includes: a waste liquid bottle 100;

[0115] The waste liquid bottle 100 is connected to the second solenoid valve 32, and a third passage is constructed based on the second solenoid valve 32 and the waste liquid bottle 100;

[0116] When the controller detects that the sample extraction is completed, it controls the second micro-injection pump 42 to close, and the second solenoid valve 32 switches to the third passage connected to the waste liquid bottle 100.

[0117] Continue to refer to Figure 1 , based on the device shown in the above embodiments of the present invention, the nitrogen oxide sampling device further includes: a third micro-injection pump 43 and a solution storage tank 110;

[0118] The first solenoid valve 31 is connected to the solution storage tank 110 through the third micro-injection pump 43;

[0119] It should be noted that the solution storage tank 110 pre-stores a preset solution, and the preset solution can be ultrapure water or other solutions, and the embodiments of the present invention do not limit this.

[0120] The fourth passage is composed of the first solenoid valve 31, the third micro-injection pump 43 and the solution storage tank 110;

[0121] When the controller determines that the second solenoid valve switches to the third passage connected to the waste liquid bottle, it controls the first solenoid valve 31 to switch to the fourth passage connected to the third micro-injection pump 43, and controls the third micro-injection pump 43 to open, so that the third micro-injection pump 43 extracts a second measurement of the preset solution from the solution storage tank 110 and injects it into the absorption bottle 20 to clean the absorption bottle;

[0122] The controller controls the third micro-injection pump 43 to close, the first solenoid valve 31 to disconnect, and the second micro-injection pump 42 to open; so that the second micro-injection pump 42 extracts the waste liquid after cleaning in the absorption bottle and injects it into the waste liquid bottle 100 through the second solenoid valve 32.

[0123] It should be noted that the second measurement is set by technicians in advance based on multiple experiments, for example, it can be set to 60 mL.

[0124] Specifically, the third micro-injection pump 43 quantitatively extracts 60 mL of ultrapure water from the solution reservoir 110 and injects it into the absorption bottle 20 to wash the residual absorption liquid in the bottle. After the controller detects that the injection of ultrapure water is completed, it controls the third micro-injection pump 43 to close and the first solenoid valve 31 to disconnect.

[0125] The controller controls the second micro-injection pump 42 to start, extracts the waste liquid after washing in the absorption bottle 20, and injects it into the waste liquid bottle 110 through the second solenoid valve 32. After the waste liquid after washing in the absorption bottle 20 is emptied, the second micro-injection pump 42 is closed and the second solenoid valve 32 is closed. After one sampling cycle of the current collection request is completed, the next sampling cycle can be executed.

[0126] Optionally, the absorption liquid reservoir 10, the waste liquid bottle 110, and the solution reservoir 100 are all arranged in the storage room 3 of the main body 1.

[0127] Among them, the storage room 3 includes a refrigeration module, and the controller controls the storage room 3 to be in a low temperature state through the refrigeration module to store the NOx absorption liquid, ultrapure water, and waste liquid.

[0128] The temperature of the storage room 3 is maintained at 4 °C.

[0129] It should be noted that the absorption liquid bottle and the ultrapure water bottle are made of brown high borosilicate glass to prevent light from affecting the absorption liquid and the growth of bacteria.

[0130] Continue to refer to Figure 1 , based on the device shown in the above embodiments of the present invention, the nitrogen oxide sampling device further includes: a radiator 120 and a heater 130 for temperature control according to the ambient temperature.

[0131] The radiator 120 and the heater 130 are arranged above the main body and are connected to the controller;

[0132] The controller detects the ambient temperature inside and outside the nitrogen oxide sampling device through temperature sensors arranged inside and outside the main body, and controls the radiator 120 and the heater 130 according to the ambient temperature.

[0133] The radiator 120 is used to cool the inside of the nitrogen oxide sampling device. When the deviation between the external ambient temperature and the internal ambient temperature is greater than the first threshold, and the internal ambient temperature is greater than the second threshold, it means that it is currently in the wild in summer and the internal temperature is too high. Effective heat dissipation can ensure the normal operation of the internal electronic components of the instrument. Therefore, the radiator 120 is controlled to dissipate heat.

[0134] The heater 130 is used to heat the inside of the sampler. When the deviation between the external ambient temperature and the internal ambient temperature is greater than the first threshold and the external ambient temperature is less than the third threshold, it indicates that it is currently in the winter in the wild and the internal temperature is too low. The NOx absorption liquid in the absorption bottle 20 may freeze, affecting normal sampling. Therefore, controlling the heater 130 to heat can effectively prevent the liquid in the absorption bottle 20 and the liquid pipeline from freezing and ensure normal sampling of the instrument.

[0135] It should be noted that the main body 1, that is, the inside of the instrument, is maintained at 20 °C.

[0136] Among them, the first threshold, the second threshold, and the third threshold are all set by technicians in advance based on multiple experiments.

[0137] Optionally, the first solenoid valve 31, the second solenoid valve 32, the first micro-injection pump 41, the second micro-injection pump 42, and the third micro-injection pump 43 are all coated with a Teflon coating to prevent the absorption liquid from corroding their interiors.

[0138] Optionally, all gas pipelines and liquid pipelines inside the main body 1 are made of Teflon material, which is corrosion-resistant and has low adsorption. The pipelines can be replaced once a month.

[0139] Optionally, the controller can be connected to multiple main bodies 1 to control the components inside multiple main bodies 1 simultaneously.

[0140] In the embodiment of the present invention, a sampling device is provided that can be used for unattended automatic sampling and collection of ambient air in urban, wild, or industrial park environments, can meet the requirements of simultaneous sampling at multiple points, and is less affected by environmental temperature and wind. After receiving the collection instruction, when the current time reaches the sampling start time, sampling begins; in the present invention, the absorption liquid is automatically filled at the first sampling time corresponding to the collection instruction to collect NOx in the atmosphere through the absorption liquid, obtaining a sample that can be reserved for isotope characteristic analysis or the original isotope characteristic; then, when the second sampling time is reached, the vacuum pump is controlled to close; based on the second solenoid valve, the second passage is controlled to open, and the controller controls the second micro-injection pump to open, so that the second micro-injection pump extracts the sample in the absorption bottle and injects it into the sample bottle. Based on the sample in the sample bottle, subsequent isotope analysis can be satisfied.

[0141] Furthermore, the sampling device shown in the present invention has high collection efficiency, is easy to operate, and is less affected by the environmental temperature and wind in the wild sampling environment. It can automatically and continuously collect ambient air without manual attendance, automatically fill the absorption liquid to automatically collect samples that can be used for isotope analysis, can adapt to long-term unattended observation of ambient air in urban, wild, and industrial park environments, and can be deployed at multiple points for simultaneous observation.

[0142] Based on the sampling device for nitrogen oxides shown in the embodiments of the present invention described above, correspondingly, the embodiments of the present invention also correspondingly show a schematic flow chart of a sampling method for nitrogen oxides, as Figure 2 shown, the method includes:

[0143] Step S201: The controller receives a collection instruction sent by the user. When the controller reaches the first sampling time corresponding to the collection instruction, it controls the first passage to open;

[0144] Step S202: The controller injects a preset amount of absorbent liquid in the absorbent liquid reservoir into the absorption bottle through the first passage;

[0145] Step S203: The controller controls the air inlet of the main body to be in an open state so that the atmosphere enters the absorption bottle from the air inlet;

[0146] Step S204: The absorption bottle uses the absorbent liquid to capture the nitrogen oxides in the atmosphere to obtain a sample.

[0147] In the execution process of each step in the sampling method for nitrogen oxides disclosed in the embodiments of the present invention described above, it is the same as the specific principles and execution processes of each component in the sampling device for nitrogen oxides provided in the embodiments of the present invention described above, and they can be referred to each other, and will not be elaborated here.

[0148] Optionally, when the controller reaches the first sampling time and controls the first passage to open, specifically:

[0149] When the controller reaches the first sampling time, it controls the first solenoid valve in the main body to switch to the first passage where the first micro-injection pump is located. The first passage includes the first micro-injection pump, the first solenoid valve, and the absorbent liquid reservoir;

[0150] Correspondingly, when the controller injects a preset amount of absorbent liquid in the absorbent liquid reservoir into the absorption bottle through the first passage, specifically:

[0151] The controller controls the first micro-injection pump to open so that the first micro-injection pump extracts a preset amount of absorbent liquid from the absorbent liquid reservoir and injects it into the absorption bottle.

[0152] Optionally, it further includes:

[0153] The atmosphere enters the filter membrane holder from the air inlet and is filtered through the microporous filter membrane and the nylon filter membrane.

[0154] Optionally, it further includes:

[0155] The controller controls the vacuum pump to open so that the air inlet of the main body is in an open state.

[0156] Optionally, it further includes:

[0157] When the controller reaches the second sampling time corresponding to the collection instruction, it controls the vacuum pump to close; based on the second solenoid valve, it controls the second passage to open, where the second passage consists of a second solenoid valve, a sample bottle, and a second micro-injection pump;

[0158] The controller controls the second micro-injection pump to open so that the second micro-injection pump extracts the sample in the absorption bottle and injects it into the sample bottle.

[0159] Optionally, it further includes:

[0160] When the controller detects that the sample extraction is completed, it controls the second micro-injection pump to close, and the second solenoid valve switches to the third passage connected to the waste liquid bottle.

[0161] Optionally, it further includes:

[0162] When the controller determines that the second solenoid valve switches to the third passage connected to the waste liquid bottle, it controls the first solenoid valve to switch to the fourth passage connected to the third micro-injection pump, and controls the third micro-injection pump to open so that the third micro-injection pump extracts a second measurement of a preset solution from the solution reservoir and injects it into the absorption bottle to clean the absorption bottle;

[0163] The controller controls the third micro-injection pump to close, the first solenoid valve disconnects, and the second micro-injection pump opens; so that the second micro-injection pump extracts the waste liquid after cleaning in the absorption bottle and injects it into the waste liquid bottle through the second solenoid valve.

[0164] In the embodiment of the present invention, upon receiving a collection instruction, sampling starts when the current time reaches the sampling start time; the present invention automatically adds an absorption liquid when reaching the first sampling time corresponding to the collection instruction to collect NOx in the atmosphere through the absorption liquid to obtain a sample that can be reserved for isotope characteristic analysis or the original isotope characteristic; then when reaching the second sampling time, it controls the vacuum pump to close; based on the second solenoid valve, it controls the second passage to open, and the controller controls the second micro-injection pump to open so that the second micro-injection pump extracts the sample in the absorption bottle and injects it into the sample bottle. So that the sample in the sample bottle can meet the subsequent isotope analysis.

[0165] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other, and the differences between each embodiment and other embodiments are emphasized. In particular, for a system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and reference can be made to the relevant parts of the method embodiment for the relevant content. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without creative work.

[0166] Those skilled in the art can further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the present invention.

[0167] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A sampling device for nitrogen oxides, characterized in that, The device includes: a controller, an absorbent liquid reservoir, and an absorption bottle; The absorbent liquid reservoir and the absorption bottle are arranged inside the main body; the controller is wirelessly connected to the absorbent liquid reservoir and the absorption bottle respectively; An air inlet for collecting the atmosphere is arranged on the main body; The controller receives a collection instruction sent by the user, and when reaching the first sampling time corresponding to the collection instruction, the controller controls the first passage to be opened; The controller injects a preset amount of absorbent liquid in the absorbent liquid reservoir into the absorption bottle through the first passage; The controller controls the air inlet of the main body to be in an open state, so that the atmosphere enters the absorption bottle from the air inlet; The absorption bottle uses the absorbent liquid to capture nitrogen oxides in the atmosphere to obtain a sample.

2. The device according to claim 1, characterized in that, It further includes: A first solenoid valve and a first micro-injection pump; The first solenoid valve is connected to the absorption bottle and the first micro-injection pump respectively; The first micro-injection pump is connected to the absorbent liquid reservoir; Wherein, when reaching the first sampling time, the controller controls the first passage to be opened, specifically for: When reaching the first sampling time, the controller controls the first solenoid valve in the main body to switch to the first passage where the first micro-injection pump is located, and the first passage includes the first micro-injection pump, the first solenoid valve, and the absorbent liquid reservoir; Correspondingly, the controller injects a preset amount of absorbent liquid in the absorbent liquid reservoir into the absorption bottle through the first passage, specifically for: The controller controls the first micro-injection pump to be turned on, so that the first micro-injection pump extracts a preset amount of absorbent liquid from the absorbent liquid reservoir and injects it into the absorption bottle.

3. The device according to claim 1, wherein It further includes: A filter membrane clamp; A microporous filter membrane and a nylon filter membrane are arranged inside the filter membrane clamp; The filter membrane clamp is arranged at the air inlet and is connected to the absorption bottle; The atmosphere enters the filter membrane clamp from the air inlet and is filtered through the microporous filter membrane and the nylon filter membrane.

4. The device according to claim 1, characterized in that, It further includes: A vacuum pump; The vacuum pump is connected to the absorption bottle; The controller controls the vacuum pump to be turned on so that the air inlet of the main body is in an open state.

5. The device according to claim 4, characterized in that, It further includes: A second solenoid valve, a sample bottle, and a second micro-injection pump; One end of the second solenoid valve is connected to a plurality of sample bottles, and the other end is connected to the absorption bottle through the second micro-injection pump; When reaching the second sampling time corresponding to the collection instruction, the controller controls the vacuum pump to be turned off; based on the second solenoid valve, the second passage is controlled to be opened, where the second passage is composed of the second solenoid valve, the sample bottle, and the second micro-injection pump; The controller controls the second micro-injection pump to be turned on, so that the second micro-injection pump extracts the sample in the absorption bottle and injects it into the sample bottle.

6. The device according to claim 5, wherein It further includes: A waste liquid bottle; The waste liquid bottle is connected to the second solenoid valve, and a third passage is constructed based on the second solenoid valve and the waste liquid bottle; When detecting that the sample extraction is completed, the controller controls the second micro-injection pump to be turned off, and the second solenoid valve switches to the third passage connected to the waste liquid bottle.

7. The device according to claim 6, characterized in that, It further includes: A third micro-injection pump and a solution storage; The first solenoid valve is connected to the solution storage through the third micro-injection pump; When the controller determines that the second solenoid valve switches to the third passage connected to the waste liquid bottle, it controls the first solenoid valve to switch to the fourth passage connected to the third micro-injection pump and controls the third micro-injection pump to start, so that the third micro-injection pump extracts a second measurement of the preset solution from the solution reservoir and injects it into the absorption bottle to clean the absorption bottle. The controller controls the third micro-injection pump to close, disconnects the first solenoid valve, and starts the second micro-injection pump; so that the second micro-injection pump extracts the waste liquid after cleaning in the absorption bottle and injects it into the waste liquid bottle through the second solenoid valve.

8. The device according to claim 7, characterized in that, The absorbent reservoir, the waste liquid bottle and the solution reservoir are all arranged in the storage room of the main body.

9. The device according to claim 1, characterized in that, It further includes: A radiator and a heater for temperature control according to the ambient temperature.

10. A sampling method for nitrogen oxides, characterized in that, Applied to the sampling device for nitrogen oxides according to any one of the above claims 1 to 9, the device includes: a controller, an absorbent reservoir and an absorption bottle; the method includes: The controller receives a collection instruction sent by the user. When the controller reaches the first sampling time corresponding to the collection instruction, it controls the first passage to open. The controller injects a pre-measured amount of absorbent from the absorbent reservoir into the absorption bottle through the first passage. The controller controls the air inlet of the main body to be in an open state, so that the atmosphere enters the absorption bottle from the air inlet. The absorption bottle uses the absorbent to capture the nitrogen oxides in the atmosphere to obtain a sample.

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