A method for online gas spike recovery

Abstract

The present invention relates to the field of environmental monitoring technology, and in particular to a method for online gas spike recovery. The technical solution of the present invention comprises the following steps: introducing a gas to be tested into a first analysis device and a second analysis device under the same conditions, analyzing and detecting the gas to be tested by the first analysis device to output a first measurement value; mixing a gas standard substance of known concentration with the gas to be tested at a specific flow rate and introducing the mixed gas into the second analysis device, analyzing and detecting the introduced mixed gas by the second analysis device to output a second measurement value; calculating a theoretical spike amount based on parameters of the gas standard substance and the gas to be tested introduced into the second analysis device; and calculating a spike recovery rate based on the difference between the first measurement value and the second measurement value and the theoretical spike amount.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental monitoring, and in particular to a method for online gas spike recovery. Background Art

[0002] Spike recovery involves adding a known concentration of a standard substance to a sample of known concentration. After a complete analytical process, the recovery rate is calculated. Spike recovery is an important tool for evaluating the accuracy and reliability of monitoring methods. Currently, spike recovery primarily involves methods for water and soil, with little research on gas spike recovery.

[0003] Currently, gas spike recovery methods are primarily implemented offline. This involves collecting and storing a gas sample to be tested. A portion of the sample is spiked with a known concentration of a gas reference material to create the spiked sample. Monitoring equipment is then used to measure both the sample and the spiked sample, and the spiked recovery rate is calculated. This recovery rate is used to assess the reliability of a specific monitoring method.

[0004] However, the technical route of using offline spike recovery testing has certain defects, such as: 1. It has high requirements for gas storage, which can easily cause sample loss and distortion, especially for some highly active species that are easily converted and adsorbed; 2. There is a relatively large uncertainty in the preparation of offline spiked samples, which can easily cause a large deviation between the actual concentration of the spiked samples and the theoretical concentration; 3. Offline spike recovery testing can often only carry out a few sets of tests, making it difficult to achieve long-term spike recovery testing and collect a large number of data samples; 4. Offline spike recovery testing involves a large amount of manual operation, which not only consumes manpower, but also has a high degree of manual error, resulting in unsatisfactory data results.

[0005] In summary, the existing gas spike technology has problems of low reliability and difficult operation that need to be solved. Summary of the Invention

[0006] In view of the above analysis, an embodiment of the present invention aims to provide a method for online spiked gas recovery, comprising:

[0007] The gas to be measured is introduced into the first analysis device and the second analysis device respectively under the same conditions, and the gas to be measured is analyzed and detected by the first analysis device to output a first measurement value;

[0008] A gas standard substance of known concentration is mixed with the gas to be measured at a specific flow rate and introduced into a second analysis device, and the introduced mixed gas is analyzed and detected by the second analysis device to output a second measurement value;

[0009] Obtaining a theoretical spiked amount based on parameter calculation of the gas standard substance and the gas to be measured passing through the second analysis device;

[0010] The spiked recovery rate is calculated based on the difference between the first measured value and the second measured value and the theoretical spiked amount.

[0011] In some embodiments, the step of introducing the gas to be tested into the first analysis device and the second analysis device under the same conditions includes:

[0012] Connecting the air inlets of the first analysis device and the second analysis device through a pipe, wherein a first drainage branch is provided on an end of the pipe close to the first analysis device, and a second drainage branch is provided on an end of the pipe close to the second analysis device;

[0013] Connecting a gas source to be tested to the pipeline, and simultaneously draining the gas at the same drainage flow rate at both ends of the pipeline through the first drainage branch and the second drainage branch;

[0014] The first analysis device and the second analysis device collect the gas to be measured at the same sampling flow rate at the same time.

[0015] In some embodiments, the first drainage branch includes a first gas flow control module and a first pump, and the end of the pipeline close to the first analysis device is connected to the first pump through the first gas flow control module;

[0016] The second drainage branch includes a second gas flow control module and a second pump, and one end of the pipeline close to the second analysis device is connected to the second pump through the second gas flow control module.

[0017] In some embodiments, the first drainage branch further includes a first particulate filter, and the pipeline is connected to the first gas flow control module through the first particulate filter;

[0018] The second drainage branch further includes a second particulate matter filter, and the pipeline is connected to the second gas flow control module through the second particulate matter filter.

[0019] In some embodiments, the first analysis device and the second analysis device are the same device.

[0020] In some embodiments, the pipeline is also connected to a gas standard substance addition branch, which includes a third gas flow control module and a gas standard substance generator. The pipeline is connected to the gas standard substance generator through the third gas flow control module.

[0021] In some embodiments, the parameters of the gas standard substance and the gas to be tested passing into the second analysis device include the set flow rates of the second gas flow control module and the third gas flow control module respectively, the parameters also include the sampling flow rate of the second analysis device, and the parameters also include the known concentration of the gas standard substance.

[0022] In some embodiments, the calculation formula for obtaining the theoretical spiked amount based on the parameter calculation of the gas standard substance and the gas to be measured passing into the second analysis device is expressed as:

[0023] ;

[0024] Indicates the known concentration of gas standard substance, unit is ppb;

[0025] Indicates the flow setting value of the third gas flow control module, in sccm;

[0026] Indicates the sampling flow rate of the second analysis device, in sccm;

[0027] Indicates the flow setting value of the second gas flow control module, in sccm.

[0028] In some embodiments, the calculation formula for obtaining the spiked recovery rate based on the difference between the first measured value and the second measured value and the theoretical spiked amount is expressed as:

[0029] ,in represents the first measurement value, Indicates the second measurement value.

[0030] The spike addition method provided by the present invention has at least the following advantages:

[0031] 1. Real-time spike recovery test of online gas samples is realized, avoiding potential problems in the storage process of gas samples;

[0032] 2. Automatically realize the spike recovery of gas samples with high spike accuracy;

[0033] 3. It can realize long-term continuous spike recovery test and obtain long-term continuous spike recovery data. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like parts throughout the drawings.

[0035] Figure 1A schematic flow chart of a method for online spiked gas recovery provided by an embodiment of the present invention;

[0036] Figure 2 This is a structural schematic diagram of a gas online spike recovery device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0038] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the term "connected" should be understood in a broad sense. For example, it can mean a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection, an electrical connection, a direct connection, or an indirect connection through an intermediate medium. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0039] The terms "top," "bottom," "above," "below," and "on" used throughout the description refer to relative positions of components of a device, such as the relative positions of top and bottom substrates within a device. It will be understood that devices are multifunctional regardless of their orientation in space.

[0040] The working surface of the present invention can be a plane or a curved surface, can be inclined, or can be horizontal. For the convenience of description, the embodiment of the present invention is placed on a horizontal surface and used on the horizontal surface, and "high and low" and "up and down" are defined in this way.

[0041] The embodiment of the present invention aims to provide a method for online gas spike recovery. Figure 1 Shown, including:

[0042] The gas to be measured is introduced into the first analysis device and the second analysis device respectively under the same conditions, and the gas to be measured is analyzed and detected by the first analysis device to output a first measurement value;

[0043] A gas standard substance of known concentration is mixed with the gas to be measured at a specific flow rate and introduced into a second analysis device, and the introduced mixed gas is analyzed and detected by the second analysis device to output a second measurement value;

[0044] Obtaining a theoretical spiked amount based on parameter calculation of the gas standard substance and the gas to be measured passing through the second analysis device;

[0045] The spiked recovery rate is calculated based on the difference between the first measured value and the second measured value and the theoretical spiked amount.

[0046] In some embodiments, the step of introducing the gas to be tested into the first analysis device and the second analysis device under the same conditions includes:

[0047] Connecting the air inlets of the first analysis device and the second analysis device through a pipe, wherein a first drainage branch is provided on an end of the pipe close to the first analysis device, and a second drainage branch is provided on an end of the pipe close to the second analysis device;

[0048] Specifically, if Figure 2 As shown, the present invention provides a gas online spike recovery device, comprising a pipeline, a first analysis device 1, a second analysis device 2, a first drainage branch, a second drainage branch, and a gas standard substance addition branch. The first analysis device 1 and the second analysis device 2 are used to analyze the gas sample to be tested.

[0049] Connecting a gas source to be tested to the pipeline, and simultaneously draining the gas at the same drainage flow rate at both ends of the pipeline through the first drainage branch and the second drainage branch;

[0050] The first analysis device and the second analysis device collect the gas to be measured at the same sampling flow rate at the same time.

[0051] In some embodiments, the first drainage branch includes a first gas flow control module 9 and a first pump 10, and the end of the pipeline close to the first analysis device 1 is connected to the first pump 10 through the first gas flow control module 9;

[0052] The second drainage branch includes a second gas flow control module 6 and a second pump 7 , and one end of the pipeline close to the second analysis device 2 is connected to the second pump 7 through the second gas flow control module 6 .

[0053] In order to ensure that the sampling conditions of the first analysis device 1 and the second analysis device 2 are the same, specifically, within the same sampling period, the first analysis device 1 and the second analysis device 2 simultaneously analyze and detect the gas sample to be tested. Among them, the sampling flow rates of the first analysis device 1 and the second analysis device 2 are exactly the same. At this time, the second gas flow control module 6 and the first gas flow control module 9 are set to the same flow control value, and the second pump 7 and the first pump 10 work simultaneously, thereby ensuring that the conditions of the two flow paths of the first analysis device 1 and the second analysis device 2 are consistent.

[0054] In some embodiments, the first drainage branch further includes a first particulate filter 8, and the pipeline is connected to the first gas flow control module 9 through the first particulate filter 8;

[0055] The second drainage branch further includes a second particulate filter 5 , and the pipeline is connected to the second gas flow control module 6 through the second particulate filter 5 .

[0056] The first drainage branch and the second drainage branch are used to drain the airflow in the sampling pipeline, wherein the first gas flow control module 9 and the second gas flow control module 6 are used to accurately control the gas flow in the pipeline. The first pump 10 and the second pump 7 are used to provide power for drainage.

[0057] The first particulate filter 8 and the second particulate filter 5 are used to filter particulate matter in the gas sample to prevent damage to the gas flow control module and the pump.

[0058] In some embodiments, the first analysis device 1 and the second analysis device 2 are the same device. Specifically, the first analysis device 1 and the second analysis device 2 are of the same model and have the same sampling flow rate.

[0059] In some embodiments, the pipeline is further connected to a gas standard substance addition branch, which includes a third gas flow control module 4 and a gas standard substance generator 3. The pipeline is connected to the gas standard substance generator 3 through the third gas flow control module 4. The gas standard substance generator 3 is used to generate a gas standard substance with a specific concentration.

[0060] Preferably, in some embodiments, before introducing the gas standard substance, the method further includes:

[0061] On the basis that the measurement results of the gas to be measured by the first analysis device 1 and the second analysis device 2 have good data parallelism, the third gas control module 4 is set with gas flow control, so that the gas standard substance of known concentration is mixed with the gas to be measured and delivered to the second analysis device 2, thereby realizing the spiked recovery of the sample measured by the second analysis device 2; at the same time, the first analysis device 1 normally analyzes and detects the sample to be measured.

[0062] In some embodiments, the parameters of the gas standard substance and the gas to be tested passing into the second analysis device include the set flow rates of the second gas flow control module and the third gas flow control module respectively, the parameters also include the sampling flow rate of the second analysis device, and the parameters also include the known concentration of the gas standard substance.

[0063] In some embodiments, the calculation formula for obtaining the theoretical spiked amount based on the parameter calculation of the gas standard substance and the gas to be measured passing into the second analysis device is expressed as:

[0064] ;

[0065] Indicates the known concentration of gas standard substance, unit is ppb;

[0066] Indicates the flow setting value of the third gas flow control module, in sccm;

[0067] Indicates the sampling flow rate of the second analysis device, in sccm;

[0068] Indicates the flow setting value of the second gas flow control module, in sccm.

[0069] In some embodiments, the calculation formula for obtaining the spiked recovery rate based on the difference between the first measured value and the second measured value and the theoretical spiked amount is expressed as:

[0070] ,in represents the first measurement value, Indicates the second measurement value.

[0071] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A method for online gas spike recovery, characterized in that: include: The gas to be tested is introduced into the first analysis device and the second analysis device respectively under the same conditions, and the gas to be tested is analyzed and detected by the first analysis device to output a first measurement value; wherein, the respective air inlets of the first analysis device and the second analysis device are connected by a pipeline, a first drainage branch is provided on the end of the pipeline close to the first analysis device, and a second drainage branch is provided on the end of the pipeline close to the second analysis device, the first drainage branch includes a first gas flow control module and a first pump, the second drainage branch includes a second gas flow control module and a second pump, and a gas standard substance addition branch is also connected to the pipeline, and the gas standard substance addition branch includes a third gas flow control module and a gas standard substance generator; the gas source to be tested is connected to the pipeline, and the same drainage flow rate is drained at both ends of the pipeline through the first drainage branch and the second drainage branch; the first analysis device and the second analysis device collect the gas to be tested at the same sampling flow rate at the same time; the first drainage branch also includes a first particulate matter filter, and the second drainage branch also includes a second particulate matter filter; A gas standard substance of known concentration is mixed with the gas to be measured at a specific flow rate and introduced into a second analysis device, and the introduced mixed gas is analyzed and detected by the second analysis device to output a second measurement value; The theoretical spiked amount is calculated based on the parameters of the gas standard substance and the gas to be measured passing through the second analysis device, and the calculation formula is expressed as: , Indicates the known concentration of gas standard substance, unit is ppb; Indicates the flow setting value of the third gas flow control module, in sccm; Indicates the sampling flow rate of the second analysis device, in sccm; Indicates the flow setting value of the second gas flow control module, in sccm; The spiked recovery rate is calculated based on the difference between the first measured value and the second measured value and the theoretical spiked amount.

2. The method for online gas spike recovery according to claim 1, wherein: One end of the pipeline close to the first analysis device is connected to the first pump through the first gas flow control module; One end of the pipeline close to the second analysis device is connected to the second pump through the second gas flow control module.

3. The method for online gas spike recovery according to claim 2, wherein: The pipeline is connected to the first gas flow control module through the first particulate matter filter; The pipeline is connected to the second gas flow control module through the second particulate matter filter.

4. The method for online gas spike recovery according to claim 1, wherein: The first analyzing device and the second analyzing device are the same device.

5. The method for online gas spike recovery according to claim 3, wherein: The pipeline is connected to the gas standard substance generator through the third gas flow control module.

6. The method for online gas spike recovery according to claim 5, characterized in that: The parameters of the gas standard substance and the gas to be tested passing into the second analysis device include the set flow rates of the second gas flow control module and the third gas flow control module respectively, the parameters also include the sampling flow rate of the second analysis device, and the parameters also include the known concentration of the gas standard substance.

7. The method for online gas spike recovery according to claim 6, characterized in that: The calculation formula for obtaining the spiked recovery rate based on the difference between the first measured value and the second measured value and the theoretical spiked amount is expressed as: ,in represents the first measurement value, Indicates the second measurement value.

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