CEMS-based direct carbon emission monitoring system and method

Abstract

The invention discloses a CEMS-based direct carbon emission monitoring system and method, and the system releases tracer gas at the upstream of a flue gas emission flow through a tracer standard gas unit, collects a flue gas sample through a downstream collection unit, monitors the concentration of the tracer standard gas in the sample through a concentration analysis unit, and combines the flue gas flow obtained by a flow monitoring unit to monitor the concentration of the tracer standard gas in the sample. And calculating a flow control coefficient so as to accurately calculate the carbon dioxide emission. The method is based on a mass flow balance method, the moisture-containing standard gas is creatively used, the concentration of CO2 under the wet flue gas condition can be directly and accurately measured, and the accuracy and efficiency of carbon emission monitoring are improved.

Description

Technical Field

[0001] This application belongs to the technical field of carbon emissions, and particularly relates to a direct carbon emissions monitoring system and method based on CEMS. Background Art

[0002] The background of carbon emissions monitoring mainly stems from the global attention to climate change and international actions to address climate change. As scientific research shows that human activities, especially the large-scale burning of fossil fuels in the industrialization process, the release of carbon dioxide (CO 2 ) and other greenhouse gas emissions have caused global climate change, which is one of the most severe challenges faced by humanity since the 21st century. Facing this challenge, the international community has reached a broad consensus on reducing carbon emissions. In order to effectively respond to climate change and achieve the dual goals of economic growth and greenhouse gas emissions reduction, the carbon emissions trading market, as an economic mechanism, has become a key tool to promote greenhouse gas emissions reduction and the development of low-carbon technologies.

[0003] Currently, there are many domestic enterprises in the CO 2 -CEMS system for directly measuring carbon emissions. For the technical methods of CO 2 concentration monitoring, the main methods are NDIR and FTIR methods, and the methods are very mature. For the technical methods of flue gas flow monitoring, the main methods are pitot tubes, ultrasonic waves, matrix flow meters, etc., which are also very mature. However, for carbon emissions monitoring and the data used for carbon trading, it is necessary to ensure the quality and traceability of CO 2 concentration and flow data. Currently, there is no relevant solution in the market for the quality assurance and traceability of emissions data (especially flow data). Summary of the Invention

[0004] Aiming at the problems of quality assurance and traceability of CO 2 emissions data (especially flow data) existing in the existing direct measurement method, this application aims to provide a CEMS system for directly measuring carbon dioxide emissions. This system replaces flow velocity monitoring with mass flow monitoring, reduces the uncertainty of flow, has controllable data quality, and is traceable.

[0005] In one aspect of this application, a direct carbon emissions monitoring system based on CEMS is provided, including:

[0006] A tracer gas unit for releasing a tracer gas with a volume concentration C v1 and a volume flow rate Q x into the upstream of the flue gas emission stream;

[0007] A collection unit for collecting flue gas samples downstream of the flue gas emission stream;

[0008] A concentration analysis unit for obtaining the volume concentration C of the tracer gas in the flue gas sample v2 and the volume concentration C of carbon dioxide i (CO 2 );

[0009] A flow rate monitoring unit for obtaining the volume flow rate Q(v) of the flue gas emission stream;

[0010] A main control analysis unit that receives the volume flow rate Q x , the volume concentration C v1 and the volume concentration C v2 to obtain the volume flow rate Q of the tracer gas in the flue gas sample:

[0011]

[0012] wherein,

[0013] Q: m 3 / h; C v1 : taking the 5-minute average, %; C v2 : taking the 5-minute average, %; Q x : L / min;

[0014] Receiving the volume flow rate Q(v) of the flue gas emission stream to obtain the flow rate quality control coefficient k(v):

[0015]

[0016] Calculating the emission of carbon dioxide in the flue gas emission stream:

[0017] G = C i (CO 2 ) × 44 / 22.4 × 10000 × Q(v) / 1000000 × k(v)

[0018] wherein,

[0019] G: the emission of carbon dioxide in the flue gas emission stream, kg / h; Q(v): m 3 / h; C i (CO 2 ): %.

[0020] In one embodiment, the tracer gas is selected from one of SF 6 , CO, Freon, perfluoroisobutyronitrile.

[0021] In one embodiment, the direct carbon emission monitoring system further includes a quality control unit, which is configured to release a quality control standard gas and guide it to the concentration analysis unit via the collection unit to obtain the concentration information of the quality control standard gas. The main control analysis unit calculates and analyzes a quality control coefficient based on the received concentration information of the quality control standard gas, and this quality control coefficient is used to calibrate the original concentration obtained by the concentration analysis unit.

[0022] In one embodiment, the quality control coefficient includes a range quality control coefficient k, a zero point quality control coefficient b, and a humidity quality control coefficient The original concentration obtained by the concentration analysis unit is quality controlled by the range quality control coefficient k, the zero point quality control coefficient b, and the humidity quality control coefficient :

[0023]

[0024] In the formula,

[0025] C i : The volume concentration of the monitored gas;

[0026] C 原始 : The volume concentration of the unquality-controlled monitored gas obtained by the concentration analysis unit;

[0027] C i (H 2 O): The humidity of the monitored gas obtained by the concentration analysis unit;

[0028] C 质控 (H 2 O): The released humidity of the quality control standard gas.

[0029] In one embodiment, the quality control standard gas includes a dry matrix quality control standard gas and a wet matrix quality control standard gas.

[0030] In one embodiment, the dry matrix quality control standard gas includes a dry base zero point standard gas and a dry base range standard gas.

[0031] In one embodiment, the dry base zero point standard gas is used to obtain the zero point quality control coefficient b:

[0032] The quality control unit releases the dry base zero point standard gas, which is guided to the concentration analysis unit via the collection unit to obtain the concentration information of carbon dioxide or the tracer gas in the dry base zero point standard gas. The main control analysis unit obtains the zero point quality control coefficient b based on the received concentration information of carbon dioxide or the tracer gas.

[0033] In one embodiment, the dry base zero point standard gas is selected from nitrogen.

[0034] In one embodiment, the dry base range standard gas is used to obtain the range quality control coefficient k:

[0035] The quality control unit releases the dry-based range calibration gas, which is guided by the collection unit to the concentration analysis unit to obtain the concentration information of the dry-based range calibration gas. The main control analysis unit obtains the range quality control coefficient k based on the received concentration information of the dry-based range calibration gas.

[0036] In one embodiment, the dry-based range calibration gas is carbon dioxide or a tracer gas.

[0037] In one embodiment, the wet-based quality control gas is used to obtain the humidity quality control coefficient

[0038] The quality control unit releases the wet-based quality control gas, which is guided by the collection unit to the concentration analysis unit to obtain the concentration information of the wet-based quality control gas. The main control analysis unit obtains the humidity quality control coefficient based on the received concentration information of the wet-based quality control gas.

[0039]

[0040] In the formula,

[0041] C 质释放 : The released volume concentration of the wet-based quality control gas;

[0042] C 质原始 : The volume concentration of the wet-based quality control gas obtained by the concentration analysis unit;

[0043] C 质控 (H 2 O): The humidity of the wet-based quality control gas obtained by the concentration analysis unit;

[0044] C i (H 2 O): The released humidity of the wet-based quality control gas.

[0045] In one embodiment, the wet-based quality control gas is a wet-based carbon dioxide calibration gas or a wet-based tracer gas.

[0046] In one embodiment, the quality control unit includes a quality control gas module and a humidity generation module. The quality control gas module is used to release the dry-based quality control gas to the collection unit, and the humidity generation module is used to receive the dry-based quality control gas and generate the wet-based quality control gas for release to the collection unit.

[0047] In one embodiment, the collection unit includes a sampling probe and a heating pipeline. The sampling probe is arranged downstream of the flue gas emission flow, and the heating pipeline is used to connect the sampling probe and the concentration analysis unit.

[0048] In one embodiment, the sampling probe is equipped with a device for filtering particulate matter.

[0049] In one embodiment, both the tracer gas and the quality control gas are transmitted through heated pipelines.

[0050] In one embodiment, the concentration analyzer unit uses a Fourier transform infrared (FTIR) gas analyzer.

[0051] In another aspect of the present application, a direct carbon emission monitoring method based on CEMS is provided, including the following steps:

[0052] Release the tracer gas with a volume concentration C v1 and a volume flow rate Q x upstream of the flue gas emission stream;

[0053] Collect a flue gas sample downstream of the flue gas emission stream, and use a monitoring device to obtain the volume concentration C v2 of the tracer gas and the volume concentration C i (CO 2 ) in the flue gas sample;

[0054] Obtain the volume flow rate Q of the tracer gas in the flue gas sample through the volume flow rate Q x , the volume concentration C v1 and the volume concentration C v2 :

[0055]

[0056] where

[0057] Q: m 3 / h; C v1 : %; C v2 : take the 5-minute average, %; Q x : L / min;

[0058] Monitor the volume flow rate Q(v) of the flue gas emission stream, and obtain the flow rate quality control coefficient k(v) with the volume flow rate Q of the tracer gas:

[0059]

[0060] Calculate the carbon dioxide emissions in the flue gas emission stream:

[0061] G = C i (CO 2 ) × 44 / 22.4 × 10000 × Q(v) / 1000000 × k(v)

[0062] where

[0063] G: Emission of carbon dioxide in the flue gas emission stream, kg / h; Q(v): m 3 / h; C i (CO 2 ): %.

[0064] In one embodiment, the tracer standard gas is selected from one of SF 6 , CO, Freon, and perfluoroisocyanide.

[0065] In one embodiment, the volume concentration C i (CO 2 ) of carbon dioxide and the volume concentration C v2 of the tracer standard gas are the concentrations after quality control:

[0066] Release the quality control standard gas to the monitoring device to obtain the concentration information of the quality control standard gas, and calculate the quality control coefficient through the concentration of the quality control standard gas at the time of release. This quality control coefficient is used to calibrate the original concentration obtained by the monitoring device to obtain the volume concentration C i (CO 2 ) of carbon dioxide and the volume concentration C v2 .

[0067] In one embodiment, the quality control coefficient includes a full-scale quality control coefficient k, a zero-point quality control coefficient b, and a humidity quality control coefficient The original concentration obtained by the quality control of the monitoring device by the full-scale quality control coefficient k, the zero-point quality control coefficient b, and the humidity quality control coefficient :

[0068]

[0069] In the formula,

[0070] C i : Volume concentration of the monitored gas;

[0071] C 原始 : Volume concentration of the unquality-controlled monitored gas obtained by the concentration analysis unit;

[0072] C i (H 2 O): Humidity of the monitored gas obtained by the concentration analysis unit;

[0073] C 质控 (H 2 O): Release humidity of the quality control standard gas.

[0074] In one embodiment, the quality control standard gas includes a dry matrix quality control standard gas and a wet matrix quality control standard gas.

[0075] In one embodiment, the dry matrix quality control standard gas includes a dry matrix zero point standard gas and a dry matrix full scale standard gas.

[0076] In one embodiment, the dry matrix zero point standard gas is used to obtain the zero point quality control coefficient b:

[0077] Release the dry matrix zero point standard gas to the monitoring device, obtain the concentration information of carbon dioxide or tracer standard gas in the dry matrix zero point standard gas, and obtain the zero point quality control coefficient b.

[0078] In one embodiment, the dry matrix zero point standard gas is selected from nitrogen.

[0079] In one embodiment, the dry matrix full scale standard gas is used to obtain the full scale quality control coefficient k:

[0080] Release the dry matrix full scale standard gas to the monitoring device, obtain the concentration information of the full scale standard gas, and analyze the full scale quality control coefficient k.

[0081] In one embodiment, the dry matrix full scale standard gas is carbon dioxide or tracer standard gas.

[0082] In one embodiment, the wet matrix quality control standard gas is used to obtain the humidity quality control coefficient

[0083] Release the wet matrix quality control standard gas to the monitoring device, obtain the concentration information of the wet matrix quality control standard gas, and obtain the humidity quality control coefficient

[0084]

[0085] Wherein,

[0086] C 质释放 , the released volume concentration of the wet matrix quality control standard gas;

[0087] C 质原始 , the volume concentration of the wet matrix quality control standard gas obtained by the concentration analysis unit;

[0088] C 质控 (H 2 O), the humidity of the wet matrix quality control standard gas obtained by the concentration analysis unit;

[0089] C i (H 2 O), the released humidity of the wet matrix quality control standard gas.

[0090] In one embodiment, the wet matrix quality control standard gas is wet-based carbon dioxide or wet-based tracer standard gas.

[0091] The beneficial effects of this application are:

[0092] This application innovatively uses the mass flow balance method. By injecting a tracer gas upstream of the flue gas emission stream, the flue gas flow rate can be accurately calculated through the volume flow rate of the tracer gas, the carbon dioxide concentration, and the volume flow rate of the flue gas emission stream downstream. The flow measurement process is not restricted by physical characteristics such as pipe shape, size differences, and uneven pipe diameters, nor is it interfered by piping conditions (such as installation conditions of elbows, valves, etc.). Compared with traditional flow calculation methods based on flow velocity monitoring, this method significantly reduces the uncertainty in flow measurement, ensuring the accuracy and reliability of flow data. At the same time, its traceability can be directly related to the tracer standard gas, further enhancing the authority and credibility of the data.

[0093] During the monitoring process of carbon emissions, this application adopts the hot wet method monitoring technology. Through quality control of humidity, it is possible to directly measure the wet-based concentration of H 2 O, CO 2 、SF 6 and the wet flue gas flow rate, avoiding the influence of component concentration loss caused by the cold dry method, eliminating the influence of H 2 O in the emissions, more accurately measuring carbon emissions, and reducing uncertainty. Compared with traditional cold dry method monitoring technology, the hot wet method effectively avoids the loss of monitored component concentration caused by gas condensation, thus ensuring the integrity of the measurement results. In addition, by accurately measuring and considering the influence of H 2 O concentration, the hot wet method can more accurately calculate carbon emissions, further reducing the uncertainty in the measurement process and improving the accuracy and scientific nature of the data. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] Figure 1 is a schematic structural diagram of the direct carbon emission monitoring system according to an embodiment of the present application;

[0095] Figure 2 is a schematic structural diagram of the direct carbon emission monitoring system with a quality control unit according to an embodiment of the present application;

[0096] Figure 3 is a schematic structural diagram of the quality control unit of the direct carbon emission monitoring system according to an embodiment of the present application;

[0097] Figure 4 is a schematic flow diagram of the direct carbon emission monitoring method according to an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0098] Hereinafter, exemplary embodiments according to the present application will be described in detail with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. It should be understood that the present application is not limited by the exemplary embodiments described herein.

[0099] Overview of the Application

[0100] At present, the field of carbon emissions monitoring still faces many challenges. Traditional carbon emissions accounting techniques mainly rely on the accounting method. The accounting method estimates the carbon emissions generated from the consumption of fossil fuels, industrial production processes, etc., and is based on a series of complex conversion formulas and coefficients. However, the accuracy of this method is affected by various factors, such as the uncertainties of fuel types, combustion efficiency, emission factors, etc., resulting in large errors in the accounting results. In addition, the accounting method is also easily affected by human interference, such as incomplete data records, inconsistent statistical methods, etc., further increasing the uncertainty of the accounting results. This not only increases the labor cost, but also makes it difficult to accurately evaluate the actual effect of energy conservation and carbon reduction, restricting the formulation and implementation of carbon emission reduction strategies.

[0101] To overcome the limitations of the accounting method, the direct measurement method CEMS has been introduced in the prior art for real-time monitoring of carbon emissions. CEMS measures the concentrations of greenhouse gases such as CO 2 in the flue gas and the flue gas flow rate in real time through sensors installed on the emission source, and then calculates the carbon emissions. However, there are still many problems in the actual application of CEMS. On the one hand, since the measurement of flue gas flow rate data is easily affected by physical characteristics such as pipe shape, size, pipe diameter, etc., and the interference of installation states such as elbows and valves, the quality assurance and traceability of the flow rate data cannot be fully guaranteed. On the other hand, during the process of directly and real-time monitoring carbon emissions, H 2 O in the flue gas has a significant impact on the detection results, easily causing deviations in the measurement results and further reducing the accuracy of the data.

[0102] In view of the problems existing in the prior art, this application proposes an innovative carbon emissions monitoring method. This method uses a wet tracer gas and is based on the mass flow balance method. By accurately measuring the ratio between the concentration of the tracer injected at the upstream section and the concentration of the diluted tracer at the downstream sampling section, the flue gas flow rate can be accurately deduced.

[0103] Specifically, the mass flow balance method of using tracer standard gas is adopted. The tracer standard gas is input upstream of the flue gas emission flow, and the flue gas flow rate is accurately calculated through the volume flow rate of the tracer standard gas, the carbon dioxide concentration, and the volume flow rate of the flue gas emission flow downstream. It can ensure the traceability of the flow rate data, and at the same time, it can eliminate the influence of physical characteristics such as the shape, size, and pipe diameter of the pipeline, as well as the installation status of elbows, valves, etc. on the flow rate measurement, and achieve high-precision measurement of the flue gas flow rate. At the same time, by controlling the humidity influence of the monitoring data downstream of the quality control flue gas, the carbon emission is calculated more accurately. Compared with the traditional nuclear algorithm and the direct measurement method of CEMS, the technical solution of this application has achieved remarkable results in reducing uncertainty. By optimizing the measurement method and data processing process, the uncertainty in the process of monitoring carbon emissions has been successfully reduced, thereby improving the accuracy and scientific nature of the data. This breakthrough provides strong technical support for the effective monitoring and scientific management of carbon emissions.

[0104] Exemplary embodiment

[0105] In one embodiment of the present application, as Figure 1 shown, a direct carbon emission monitoring system based on CEMS includes a tracer standard gas unit, a collection unit, a concentration analysis unit, a flow rate monitoring unit, and a main control analysis unit.

[0106] Among them, the tracer standard gas unit is connected to the upstream of the flue gas emission flow through a transmission pipeline, and is used to release the tracer standard gas to the upstream of the flue gas emission flow at a volume concentration C v1 and a volume flow rate Q x . The input end of the collection unit is arranged downstream of the flue gas emission flow, and the output end is communicated with the concentration analysis unit through a transmission pipeline, and is used to collect flue gas samples downstream of the flue gas emission flow and transmit the collected flue gas samples to the concentration analysis unit. The concentration analysis unit is signal-connected to the main control analysis unit, and obtains the volume concentration C v2 of the tracer standard gas and the volume concentration C i (CO 2 ) in the flue gas sample by analyzing the received flue gas sample, and transmits it to the main control analysis unit. The flow rate monitoring unit is arranged on the flue gas emission flow and is signal-connected to the main control analysis unit, and transmits the obtained volume flow rate Q(v) of the flue gas emission flow to the main control analysis unit. The main control analysis unit is signal-connected to the tracer standard gas unit, and is used to control the tracer standard gas unit to release the tracer standard gas, and receive the volume concentration C v1 and the volume flow rate Q x when the tracer standard gas is released. The main control analysis unit calculates according to the volume flow rate Q x , the volume concentration C v1and the volume concentration C v2 Analyze the volume flow rate Q of the tracer gas in the flue gas sample, and then obtain the flow quality control coefficient k(v) through the volume flow rate Q of the tracer gas and the volume flow rate Q(v) of the flue gas emission flow, so as to calculate the emission amount of carbon dioxide in the flue gas emission flow.

[0107] Specifically, the control analysis unit receives the volume flow rate Q x and the volume concentration C v1 and the volume concentration C v2 Analyze the volume flow rate Q of the tracer gas in the flue gas sample:

[0108]

[0109] In the formula,

[0110] Q: The volume flow rate of the tracer gas in the flue gas sample, m 3 / h;

[0111] C v1 : The volume concentration when the tracer gas is released, taking the 5-minute average value;

[0112] C v2 : The volume concentration of the tracer gas obtained by the concentration analysis unit, taking the 5-minute average value;

[0113] Q x : The volume flow rate when the tracer gas is released, taking the 5-minute average value, L / min.

[0114] When the tracer gas is a pure gas, the volume concentration C v1 = 1, and the above formula is simplified to:

[0115]

[0116] Obtain the flow quality control coefficient k(v) through the volume flow rate Q of the tracer gas and the volume flow rate Q(v) of the flue gas emission flow:

[0117]

[0118] Calculate the emission amount of carbon dioxide in the flue gas emission flow:

[0119] G = C i (CO 2 ) × 44 / 22.4 × 10000 × Q(v) / 1000000 × k(v)

[0120] In the formula,

[0121] G: The emission amount of carbon dioxide in the flue gas emission flow, kg / h;

[0122] Q(v): The volumetric flow rate of the flue gas emission stream, m 3 / h;

[0123] C i (CO 2 ): The volume concentration of carbon dioxide in the flue gas emission stream, %;

[0124] k(v): Flow quality control coefficient.

[0125] In the present application, the flue gas emission stream specifically refers to the gaseous mixture generated from various industrial processes, combustion equipment or other emission sources and usually discharged into the atmosphere through a chimney. These mixtures contain various gas components, including but not limited to carbon dioxide, carbon monoxide, nitrogen oxides, sulfur oxides, particulate matter, water vapor, and unburned hydrocarbons, etc. Their composition, concentration, temperature, flow rate, pressure and other parameters vary with the type of emission source, operating conditions, fuel characteristics and flue gas purification measures.

[0126] In the application, the terms "downstream" and "upstream" are used to describe the flow direction and relative position of substances, energy or information in a system, process or device. In the flue gas emission process, upstream refers to the area or component that the flue gas first passes through. Relative to the upstream, downstream refers to the area or component that the flue gas continues to flow to after passing through the upstream area or component. At the same time, in the flue gas emission process, the flow direction of the flue gas is from upstream to downstream. This directionality is reflected not only in the physical space but also in the logical sequence of processing steps. Upstream processing is the premise and basis for downstream processing, and downstream processing is to further optimize and ensure the results of upstream processing.

[0127] In some embodiments, the tracer gas unit includes a tracer gas source and a flow controller. The tracer gas source provides high-purity tracer gas as a "marker" for monitoring or research. The tracer gas is usually stored in high-pressure cylinders, and the cylinders should meet relevant safety standards (such as ISO, GB, etc.) and be equipped with a pressure reducing valve to control the gas release pressure. The flow controller is used to precisely control the release flow rate of the tracer gas to ensure that it enters the flue gas emission stream at a set volumetric flow rate. The flow controller is connected to the output end of the tracer gas source, and the output end of the flow controller is connected to the upstream of the flue gas emission stream through a transmission pipeline, and the flow controller is signal-connected to the main control analysis unit for transmitting the volumetric concentration C v1 and volumetric flow rate Q x to the main control analysis unit.

[0128] The tracer gas is selected as a gas with a small content and good diffusibility in the flue gas.

[0129] In some embodiments, the tracer gas may be ethane, propane, acetylene, carbon monoxide, or Freon, perfluoroisocyanide, helium, or sulfur hexafluoride. These tracer gases have chemical stability and do not react with flue gas components, and have a low background concentration in the atmosphere to reduce interference with experimental data. The purity of the tracer gas is ≥99.9% to ensure the accuracy of the experiment or monitoring.

[0130] Preferably, the tracer gas is selected from sulfur hexafluoride. SF 6 Due to its unique physical and chemical properties, such as chemical stability, low reactivity, difficulty in reacting with other substances, and high sensitivity under specific detection means, it becomes an ideal tracer gas. When SF 6 is mixed with the flue gas and released into the environment, it will diffuse along with the flow of the flue gas and can be detected with high sensitivity under specific detection means. By tracking the 6 concentration change of SF, the flow path, velocity, and diffusion range of the flue gas can be indirectly reflected, and then the distribution and concentration change of carbon dioxide can be analyzed.

[0131] After the tracer gas is released, it needs to be fully mixed with the flue gas so that a representative flue gas sample can be obtained at the sampling point. If the release point is too close to the sampling point, it may cause a high-concentration area of the tracer gas to form in a local area, while the concentration in other areas is relatively low, which will seriously affect the accuracy and reliability of the flue gas sample. Therefore, the distance between the tracer gas release point and the flue gas sample sampling point needs to be controlled.

[0132] In some embodiments, the distance between the tracer gas release point and the flue gas sample sampling point is at least 5 m. For example, it can be 5 m, 6 m, 7 m, 8 m, 9 m, 10 m.

[0133] In some embodiments, the flow rate monitoring unit calculates the volume flow rate of the flue gas by measuring the flow velocity of the flue gas. Specifically, Doppler radar technology is used, where a radar sensor emits and receives microwave signals, and the flow velocity of the flue gas is calculated by measuring the frequency change of the microwave signals; or ultrasonic technology is used, where an ultrasonic sensor emits and receives ultrasonic signals, and the flow velocity of the flue gas is calculated by using the change in signal propagation time; or a thermal flow meter is used, where a hot wire or hot film sensor measures the flow velocity of the flue gas. When the flue gas flows through the sensor, it will carry away heat, and the flow velocity can be deduced by measuring the change in heat.

[0134] The volume flow rate Q(v) of the flue gas emission stream obtained by the flow rate monitoring unit is:

[0135]

[0136] In the formula,

[0137] Q(v): Volumetric flow rate of the flue gas emission stream, m 3 / h;

[0138] S: Area of the monitoring section of the flue gas emission stream, m 2 ;

[0139] v: Flow velocity of the flue gas emission stream, taking the 5-minute average value, m / s;

[0140] t s : Flue gas temperature of the flue gas emission stream, °C;

[0141] B a : Atmospheric pressure, Pa;

[0142] P s : Static pressure of the flue gas in the flue gas emission stream, Pa;

[0143] In some embodiments, the flow monitoring unit is arranged near the collection port of the collection unit to ensure the consistency of the monitored flow data and the collected flue gas sample data in terms of time and space, thereby reducing...

[0144] In some embodiments, the collection unit includes a sampling probe, a sampling rod, and a heating tracing pipeline. One end of the sampling rod is connected to the sampling probe through a sealed connector, and this connection is usually designed to be detachable for easy maintenance and replacement of the sampling probe. The sampling rod serves to support and transmit the flue gas sample and ensures that there is no leakage of the flue gas sample during the collection process. The other end of the sampling rod is connected to the inlet of the heating tracing pipeline to transmit the collected flue gas sample to the heating tracing pipeline for heating treatment to prevent the condensation of water vapor in the flue gas during transmission, thereby avoiding interference with subsequent analysis. The outlet of the heating tracing pipeline is connected to the concentration analysis unit, such as being connected to the inlet of a Fourier transform infrared (FTIR) gas analyzer, to send the heated flue gas sample into the analysis instrument for detection. In practical applications, the collection unit may also include other auxiliary components, such as flow meters, pressure reducing valves, filters, etc., for further controlling and optimizing the collection and transmission process of the flue gas sample. To reduce the influence of impurities (such as dust, oil mist, particulate matter, etc.) in the flue gas sample on the detection results, a device specifically for filtering particulate matter is equipped on the sampling probe. This filtering device is usually a combination of one or more filter elements, and different types of filter materials, such as fiberglass, ceramics, metal mesh, polymer membranes, etc., can be selected according to the requirements of filtration accuracy and efficiency. The filtering device is designed and installed at the inlet or inside of the sampling probe to pre-treat the flue gas before it enters the detection instrument.

[0145] In some embodiments, the traced pipeline includes an inner gas pipeline, an electric heating tape, a heat insulation layer, a thermal insulation layer and an outer protective sleeve. The inner gas pipeline is the core part of the traced pipeline and is used to transport the medium that needs to be heat-insulated or heated, such as the humidified tracer gas. The electric heating tape is wound outside the gas pipeline to provide a heating function. According to the working principle, the electric heating tape can be divided into a self-limiting temperature type and a constant power type. The self-limiting temperature type electric heating tape has a limited heating temperature, while the constant power type electric heating tape can adjust the heating temperature through a temperature controller. The heat insulation layer is located outside the electric heating tape to reduce heat dissipation and improve the heat insulation effect. The thermal insulation layer is located outside the heat insulation layer to further provide a heat insulation function and ensure the overall heat insulation performance of the traced pipeline. The outer protective sleeve is the outermost layer of the traced pipeline, providing mechanical protection and preventing damage to the traced pipeline caused by the external environment.

[0146] In some embodiments, the concentration analysis unit is used to online monitor the volume concentration C of the tracer gas in the flue gas sample v2 and the volume concentration C of carbon dioxide i (CO 2 ) and feed the data back to the main control analysis unit. Among them, the type of concentration sensor is selected according to the characteristics of the tracer gas, such as an infrared absorption spectrometer, an electrochemical sensor or a mass spectrometer, etc., to ensure that the measurement accuracy and response speed meet the application requirements. Specifically, the concentration analysis unit uses a Fourier transform infrared (FTIR) gas analyzer. In the detection process, first, an infrared light source emits broadband infrared radiation, and then the pre-treated flue gas sample is introduced into the sample cell of the FTIR analyzer. In the sample cell, infrared light of a specific wavelength is absorbed by the tracer gas and carbon dioxide molecules, resulting in the attenuation of the infrared radiation intensity. This attenuation process is converted into an interference pattern by an interferometer and recorded by a detector. Then, a Fourier transform algorithm is used to perform a mathematical transformation on the interference pattern to convert it into a spectrum diagram that is easy to interpret. In the spectrum diagram, the absorption peaks of the humidified tracer gas and carbon dioxide can be identified, and by measuring the intensity of these absorption peaks and combining with the Beer-Lambert law, the concentrations of these two gases in the flue gas sample can be obtained.

[0147] In the application, the main control analysis unit specifically refers to a core device integrating control logic and data processing capabilities. It is responsible for coordinating and controlling the key operations of the entire flue gas emission monitoring system. Specifically, this unit not only controls the precise release of the tracer gas by the tracer gas unit, but also receives and analyzes the data from the concentration analysis unit and the flow detection unit, and then performs complex calculation tasks to obtain key parameters such as the flow rate of the flue gas emission stream and the carbon dioxide emission.

[0148] In some embodiments, the main control and analysis unit serves as the "brain" of the entire system and includes a central processing unit (CPU), a data acquisition module, a communication interface, a storage module, and a power supply module. Hardware components such as the CPU, data acquisition module, communication interface, storage module, and power supply module are integrated to form a complete main control and analysis unit. Among them, an industrial-grade processor is selected for the CPU, such as the processor in an embedded industrial control board or a PLC (programmable logic controller), which supports floating-point operations and multi-threaded processing to improve data processing capabilities and response speeds. The data acquisition module includes a multi-channel analog input module for receiving analog signals from sensors (such as 4-20 mA or 0-10 V); a digital input module for receiving pulse signals or other digital signals; and an RS485 communication interface for communicating with external devices (such as gas analyzers, flow meters). The communication interface can be an Ethernet interface that supports the Modbus TCP / IP protocol for communicating with a monitoring center or a remote server; or a wireless communication module (such as 4G / LTE) for wireless data transmission. The storage module can be an industrial-grade memory, such as a solid-state drive (SSD) or a flash card. The power supply module has a wide voltage input range (such as 100-240 V AC) to adapt to power conditions in different regions, and at the same time, it has a built-in battery backup module to ensure that data is not lost in case of a power outage.

[0149] In another embodiment of the present application, as Figure 2 shown, a direct carbon emission monitoring system based on CEMS includes a tracer gas unit, a sampling unit, a concentration analysis unit, a flow rate monitoring unit, a main control and analysis unit, and a quality control unit. The sampling unit is used to collect a flue gas sample downstream of the flue gas emission stream; the concentration analysis unit is used to obtain the volume concentration C v2 of the tracer gas and the volume concentration C i (CO 2 ) in the flue gas sample; the flow rate monitoring unit is used to obtain the volume flow rate Q(v) of the flue gas emission stream; the main control and analysis unit receives the volume flow rate Q x , the volume concentration C v1 , and the volume concentration C v2 to analyze and obtain the volume flow rate Q of the tracer gas in the flue gas sample, receives the volume flow rate Q(v) of the flue gas emission stream, obtains a flow rate quality control coefficient k(v), and calculates the carbon dioxide emissions in the flue gas emission stream.

[0150] Among them, the quality control unit includes a quality control standard gas source, which is connected to the input end of the collection unit through a heat tracing pipeline, such as connected to a sampling probe. The quality control standard gas source releases quality control standard gas, which is guided by the collection unit to the concentration analysis unit to obtain the concentration information of the quality control standard gas. The main control analysis unit calculates and analyzes a quality control coefficient based on the concentration information of the quality control standard gas, and this quality control coefficient is used to calibrate the original concentration obtained by the concentration analysis unit. The quality control standard gas source is usually stored in the form of a high-pressure steel cylinder. The steel cylinder should comply with relevant safety standards (such as ISO, GB, etc.) and be equipped with a pressure reducing valve to control the gas release pressure.

[0151] In some embodiments, in order to control the release flow rate of the quality control standard gas, a flow controller is connected to the output end of the quality control standard gas source, which is used to accurately control the release flow rate of the quality control standard gas to ensure that it enters the collection unit at a set flow rate. The output end of the flow controller is connected to the collection unit through a heat tracing pipeline, and the flow controller is signal-connected to the main control analysis unit to transmit the concentration information of the quality control standard gas to the main control analysis unit.

[0152] In some embodiments, the quality control standard gas includes a dry-based quality control standard gas and a wet-based quality control standard gas.

[0153] In this application, the dry-based quality control standard gas refers to a quality control standard gas that has been specially treated to remove or significantly reduce the water content therein under certain conditions (such as temperature, pressure, etc.). Its characteristic is that the water content in the gas is extremely low, usually lower than a certain preset threshold (such as the dew point temperature is extremely low or the relative humidity is close to zero) to ensure the stability of gas components and measurement accuracy. It includes, but is not limited to, single or mixed gases such as nitrogen, oxygen, carbon dioxide, tracer standard gas, etc. after drying treatment.

[0154] In this application, the wet-based quality control standard gas refers to a quality control standard gas containing a certain amount of water, and its water content is accurately controlled according to specific application requirements. Such as humidified nitrogen, oxygen, carbon dioxide, tracer standard gas, etc.

[0155] In some embodiments, the dry-based quality control standard gas includes a dry-based zero-point standard gas and a dry-based full-scale standard gas. In this application, the dry-based zero-point standard gas is used to obtain the zero-point quality control coefficient b, and the dry-based full-scale standard gas is used to obtain the full-scale quality control coefficient k.

[0156] In some embodiments, the dry-based zero-point standard gas is used to obtain the zero-point quality control coefficient b: the quality control unit releases the dry-based zero-point standard gas, which is guided by the collection unit to the concentration analysis unit to obtain the concentration information of carbon dioxide or tracer standard gas in the dry-based zero-point standard gas, and the main control analysis unit analyzes the zero-point quality control coefficient b based on the received concentration information of carbon dioxide or tracer standard gas.

[0157] Specifically, the zero-point quality control coefficient b(CO 2 ) is as follows:

[0158] b(CO 2 ) = C 质标 (CO 2 ) - C 质原始 (CO 2 )

[0159] In the formula,

[0160] C 质标 (CO 2 ): The volume concentration of carbon dioxide in the dry-based zero-point calibration gas. Here, the dry-based zero-point calibration gas is a non-carbon dioxide gas;

[0161] C 质原始 (CO 2 ): The original volume concentration of carbon dioxide in the dry-based zero-point calibration gas obtained by the concentration analysis unit.

[0162] Among them, since the dry-based zero-point calibration gas is a non-carbon dioxide gas and the volume concentration of carbon dioxide in the dry-based zero-point calibration gas is 0, the zero-point quality control coefficient b(CO 2 ) is as follows:

[0163] b(CO 2 ) = 0 - C 质原始 (CO 2 ).

[0164] The zero-point quality control coefficient b(tracer) of the tracer calibration gas is as follows:

[0165] b(tracer) = C 质标 (tracer) - C 质原始 (tracer)

[0166] In the formula,

[0167] C 质标 (tracer): The volume concentration of the tracer calibration gas in the dry-based zero-point calibration gas. Here, the dry-based zero-point calibration gas is a non-tracer calibration gas;

[0168] C 质原始 (tracer): The original volume concentration of the tracer calibration gas in the dry-based zero-point calibration gas obtained by the concentration analysis unit;

[0169] Among them, since the quality control calibration gas is a non-tracer calibration gas and the volume concentration of the tracer calibration gas in the quality control calibration gas is 0, the zero-point quality control coefficient b(tracer) is as follows:

[0170] b(tracer) = 0 - C 质原始 (tracer).

[0171] In some embodiments, the dry-based zero-point calibration gas is selected from nitrogen with a purity greater than 99%.

[0172] In some embodiments, the dry-based range calibration gas is used to obtain the range quality control coefficient k: the quality control unit releases the dry-based range calibration gas, which is guided by the collection unit to the concentration analysis unit to obtain the concentration information of the dry-based range calibration gas, and the main control analysis unit analyzes the range quality control coefficient k based on the received concentration information of the dry-based range calibration gas.

[0173] The range quality control coefficient k(CO 2 ) uses the same dry-based zero calibration gas, that is, when calibrating the range quality control coefficient of carbon dioxide, the dry-based zero calibration gas is carbon dioxide gas.

[0174] Then, the range quality control coefficient k(CO 2 ) is:

[0175] k(CO 2 ) = (C 质标 (CO 2 ) - b(CO 2 )) / C 质原始 (CO 2 )

[0176] In the formula,

[0177] C 质标 (CO 2 ) is the volume concentration when the dry-based carbon dioxide calibration gas is released;

[0178] b(CO 2 ) is the zero quality control coefficient of carbon dioxide;

[0179] C 质原始 (CO 2 ) is the original volume concentration of the dry-based range calibration gas obtained by the concentration analysis unit.

[0180] The range quality control coefficient k(trace) of the tracer calibration gas uses the same dry-based zero calibration gas, that is, when calibrating the range quality control coefficient of the tracer calibration gas, the dry-based zero calibration gas is the same gas as the tracer calibration gas.

[0181] Then, the range quality control coefficient k(trace) of the tracer calibration gas is:

[0182] k(trace) = (C 质标 (trace) - b(trace)) / C 质原始 (trace)

[0183] In the formula,

[0184] C 质标 (trace) is the volume concentration when the tracer calibration gas is released;

[0185] b (Tracer): Zero-point quality control coefficient of the tracer calibration gas

[0186] C 质原始 (Tracer): The original volume concentration of the tracer calibration gas obtained by the concentration analysis unit

[0187] Update the zero-point quality control coefficient b(CO 2 ), zero-point quality control coefficient b (Tracer), full-scale quality control coefficient k(CO 2 ) and full-scale quality control coefficient k (Tracer) to the concentration analysis unit

[0188] Since the humidity C i (H 2 O) of the dry matrix calibration gas is 0. When the dry matrix calibration gas is carbon dioxide, calibrate the original volume concentration of carbon dioxide in the flue gas sample obtained by the concentration analysis unit:

[0189]

[0190] Where

[0191] C 原始 (CO 2 ): The uncalibrated original volume concentration of the carbon dioxide dry matrix calibration gas obtained by the concentration analysis unit

[0192] C i (H 2 O): The humidity of the carbon dioxide dry matrix calibration gas obtained by the concentration analysis unit

[0193] C 质控 (H 2 O): The released humidity of the carbon dioxide dry matrix calibration gas

[0194] Humidity quality control coefficient of the carbon dioxide dry matrix calibration gas

[0195] Since the humidity C i (H 2 O) of the dry matrix calibration gas is 0. When the dry matrix calibration gas is the tracer calibration gas, calibrate the original volume concentration of the dry matrix calibration gas obtained by the concentration analysis unit:

[0196]

[0197] Where

[0198] C 原始 (Tracer): The uncalibrated original volume concentration of the tracer calibration gas obtained by the concentration analysis unit

[0199] C i (H 2(O): The humidity of the tracer dry matrix control standard gas obtained by the concentration analysis unit;

[0200] C 质控 (H 2 (O): The release humidity of the tracer dry matrix control standard gas;

[0201] The humidity quality control coefficient of the tracer dry matrix control standard gas.

[0202] In some embodiments, the wet matrix control standard gas is used to obtain the humidity quality control coefficient

[0203] The quality control unit releases the wet matrix control standard gas, which is guided by the collection unit to the concentration analysis unit to obtain the concentration information of the wet matrix control standard gas, and the main control analysis unit obtains the humidity quality control coefficient according to the received concentration information of the wet matrix control standard gas

[0204] Wherein, the wet matrix control standard gas is a wet-based carbon dioxide standard gas or a wet-based tracer standard gas.

[0205] When the wet matrix control standard gas is a wet-based carbon dioxide standard gas, the humidity quality control coefficient of carbon dioxide is:

[0206]

[0207] It is deduced that:

[0208]

[0209] In the formula,

[0210] C 质标 (CO 2 ): The release volume concentration of the wet-based carbon dioxide standard gas;

[0211] C 质原始 (CO 2 ): The original volume concentration of the wet-based carbon dioxide standard gas obtained by the concentration analysis unit;

[0212] C 质控 (H 2 O): The humidity of the wet-based carbon dioxide standard gas obtained by the concentration analysis unit;

[0213] C 质标 (H 2 O): The release humidity of the wet-based carbon dioxide standard gas.

[0214] When the wet matrix control standard gas is a wet-based tracer control standard gas, the humidity quality control coefficient of the tracer standard gas is:

[0215] Derived from

[0216] It is derived that:

[0217]

[0218] Wherein,

[0219] C 质标 (Tracer): Release volume concentration of the tracer standard gas on wet basis;

[0220] C 质原始 (Tracer): Original volume concentration of the tracer standard gas on wet basis obtained by the concentration analysis unit;

[0221] C 质控 (H 2 O): Humidity of the tracer standard gas on wet basis obtained by the concentration analysis unit;

[0222] C 质标 (H 2 O): Release humidity of the tracer standard gas on wet basis.

[0223] In some embodiments, as Figure 3 shown, the quality control unit includes a quality control standard gas module and a humidity generation module. The quality control standard gas module is used to release the quality control standard gas to the collection unit, and the humidity generation module is used to receive the quality control standard gas and generate the wet-based quality control standard gas and release it to the collection unit. Specifically, the quality control standard gas module includes a quality control standard gas source and a flow controller. The output of the quality control standard gas source is connected to the flow controller, and the flow controller is respectively connected to the collection unit and the humidity generation module through a multi-way valve. The humidity generation module receives the quality control standard gas and generates the wet-based quality control standard gas. In order to achieve real-time and precise control of the wet-based quality control standard gas, temperature and humidity sensors can also be provided on the output pipeline of the humidity generation module. The sensors are connected to the main control analysis unit through signal lines, and transmit parameters such as the real-time monitored temperature and humidity to the main control analysis unit. The main control analysis unit adjusts the outputs of the flow controller and the humidity generation module according to the feedback signal of the sensors to keep the concentration and humidity of the wet-based quality control standard gas within a preset range.

[0224] In another embodiment of the present application, as Figure 4 shown, a direct carbon emission monitoring method based on CEMS is provided, including the following steps:

[0225] Release the tracer standard gas with a volume concentration of C v1 and a volume flow rate of Q x Release the tracer standard gas to the upstream of the flue gas emission stream;

[0226] Collect a flue gas sample downstream of the flue gas emission stream, and use a monitoring device to obtain the volume concentration C of the tracer gas in the flue gas sample v2 and the volume concentration C of carbon dioxide i (CO 2 );

[0227] Analyze the volume flow rate Q x 、the volume concentration C v1 and the volume concentration C v2 to obtain the volume flow rate Q(SF 6 ) of the tracer gas in the flue gas sample:

[0228]

[0229] In the formula,

[0230] Q(SF 6 ): m 3 / h; C v1 : %; C v2 : Take the 5-minute average, %; Q x : L / min;

[0231] Monitor the volume flow rate Q(v) of the flue gas emission stream and the volume flow rate Q(SF 6 ) of the tracer gas to obtain the flow quality control coefficient k(v):

[0232]

[0233] Calculate the carbon dioxide emission in the flue gas emission stream:

[0234] G = C i (CO 2 ) × 44 / 22.4 × 10000 × Q(v) / 1000000 × k(v)

[0235] In the formula,

[0236] G: The carbon dioxide emission in the flue gas sample, kg / h; Q(v): m 3 / h; C i (CO 2 ): %.

[0237] In one embodiment, the tracer gas is selected from one of SF 6 , CO, Freon, perfluoroisocyanide.

[0238] In one embodiment, the monitored carbon dioxide volume concentration C i (CO 2 ) and the tracer gas volume concentration C v2Perform quality control:

[0239] Release the quality control standard gas to the monitoring device to obtain the concentration information of the quality control standard gas, and obtain the quality control coefficient by comparing with the concentration of the quality control standard gas at the time of release. This quality control coefficient is used to calibrate the original concentration obtained by the monitoring device.

[0240] In one embodiment, the quality control coefficient includes a range quality control coefficient k, a zero point quality control coefficient b, and a humidity quality control coefficient The original concentration obtained by the monitoring device is calibrated by the range quality control coefficient k, the zero point quality control coefficient b, and the humidity quality control coefficient :

[0241]

[0242] Wherein,

[0243] C i : The volume concentration of carbon dioxide or the volume concentration of the tracer gas in the flue gas sample after calibration;

[0244] C 原始 , The uncalibrated volume concentration of carbon dioxide or the volume concentration of the tracer gas in the flue gas sample obtained by the monitoring device;

[0245] C i (H 2 O), The humidity of the flue gas sample obtained by the monitoring device;

[0246] C 质控 (H 2 O), The release humidity of the quality control standard gas.

[0247] In one embodiment, the quality control standard gas includes a dry quality control standard gas and a wet quality control standard gas.

[0248] In one embodiment, the dry quality control standard gas includes a dry base zero point standard gas and a dry base range standard gas.

[0249] In one embodiment, the dry base zero point standard gas is used to obtain the zero point quality control coefficient b:

[0250] Release the dry base zero point standard gas to the monitoring device, obtain the concentration information of carbon dioxide or the tracer gas in the dry base zero point standard gas, and analyze to obtain the zero point quality control coefficient b.

[0251] Specifically, the zero point quality control coefficient b(CO 2 ) is:

[0252] b(CO 2 ) = C 质标 (CO 2 ) - C 质原始(CO 2 )

[0253] In the formula,

[0254] C 质标 (CO 2 ): The volume concentration of carbon dioxide in the dry-based zero calibration gas, where the dry-based zero calibration gas is a non-carbon dioxide gas;

[0255] C 质原始 (CO 2 ): The original volume concentration of carbon dioxide in the dry-based zero calibration gas obtained by the concentration analysis unit.

[0256] Among them, since the dry-based zero calibration gas is a non-carbon dioxide gas and the volume concentration of carbon dioxide in the dry-based zero calibration gas is 0, the zero-point quality control coefficient b(CO 2 ) is:

[0257] b(CO 2 ) = 0 - C 质原始 (CO 2 ).

[0258] The zero-point quality control coefficient b(trace) of the tracer calibration gas is:

[0259] b(trace) = C 质标 (trace) - C 质原始 (trace)

[0260] In the formula,

[0261] C 质标 (trace): The volume concentration of the tracer calibration gas in the dry-based zero calibration gas, where the dry-based zero calibration gas is a non-tracer calibration gas;

[0262] C 质原始 (trace): The original volume concentration of the tracer calibration gas in the dry-based zero calibration gas obtained by the concentration analysis unit;

[0263] Among them, since the quality control calibration gas is a non-tracer calibration gas and the volume concentration of the tracer calibration gas in the quality control calibration gas is 0, the zero-point quality control coefficient b(trace) is:

[0264] b(trace) = 0 - C 质原始 (trace).

[0265] In one embodiment, the dry-based zero calibration gas is selected from nitrogen.

[0266] In one embodiment, the dry-based full-scale calibration gas is used to obtain the full-scale quality control coefficient k:

[0267] Release the dry-based full-scale calibration gas to the monitoring device, obtain the concentration information of the full-scale calibration gas, and analyze the full-scale quality control coefficient k.

[0268] Specifically, the range quality control coefficient k(CO 2 ) uses the same dry-based zero calibration gas, that is, when calibrating the range quality control coefficient of carbon dioxide, the dry-based zero calibration gas is carbon dioxide gas.

[0269] Then, the range quality control coefficient k(CO 2 ) is:

[0270] k(CO 2 ) = (C 质标 (CO 2 ) - b(CO 2 )) / C 质原始 (CO 2 )

[0271] In the formula,

[0272] C 质标 (CO 2 ) is the volume concentration when the dry-based carbon dioxide calibration gas is released;

[0273] b(CO 2 ) is the zero quality control coefficient of carbon dioxide;

[0274] C 质原始 (CO 2 ) is the original volume concentration of the dry-based range calibration gas obtained by the concentration analysis unit.

[0275] The range quality control coefficient k(trace) of the tracer calibration gas uses the same dry-based zero calibration gas, that is, when calibrating the range quality control coefficient of the tracer calibration gas, the dry-based zero calibration gas is the same gas as the tracer calibration gas.

[0276] Then, the range quality control coefficient k(trace) of the tracer calibration gas is:

[0277] k(trace) = (C 质标 (trace) - b(trace)) / C 质原始 (trace)

[0278] In the formula,

[0279] C 质标 (trace) is the volume concentration when the tracer calibration gas is released;

[0280] b(trace) is the zero quality control coefficient of the tracer calibration gas;

[0281] C 质原始 (trace) is the original volume concentration of the tracer calibration gas obtained by the concentration analysis unit.

[0282] In one embodiment, the dry-based range calibration gas is carbon dioxide or a tracer calibration gas.

[0283] In one embodiment, the wet matrix quality control standard gas is used to obtain a humidity quality control coefficient.

[0284] Release the wet matrix quality control standard gas to the monitoring device, obtain the concentration information of the wet matrix quality control standard gas, and analyze the humidity quality control coefficient.

[0285]

[0286] In the formula,

[0287] C 质标 : The released volume concentration of the wet matrix quality control standard gas;

[0288] C 质原始 : The volume concentration of the wet matrix quality control standard gas obtained by the concentration analysis unit;

[0289] C 质控 (H 2 O): The humidity of the wet matrix quality control standard gas obtained by the concentration analysis unit;

[0290] C 质标 (H 2 O): The released humidity of the wet matrix quality control standard gas.

[0291] Specifically, when the wet matrix quality control standard gas is a wet-based carbon dioxide standard gas, the humidity quality control coefficient of carbon dioxide is:

[0292] From

[0293] it is deduced that:

[0294]

[0295] In the formula,

[0296] C 质标 (CO 2 ) : The released volume concentration of the wet-based carbon dioxide standard gas;

[0297] C 质原始 (CO 2 ) : The original volume concentration of the wet-based carbon dioxide standard gas obtained by the concentration analysis unit;

[0298] C 质控 (H 2 O) : The humidity of the wet-based carbon dioxide standard gas obtained by the concentration analysis unit;

[0299] C 质标 (H 2 O) : The released humidity of the wet-based carbon dioxide standard gas.

[0300] When the wet-based quality control standard gas is the wet-based tracer quality control standard gas, the humidity quality control coefficient of the tracer standard gas is as follows:

[0301] From

[0302] it is deduced that:

[0303]

[0304] In the formula,

[0305] C 质标 (tracer): the released volume concentration of the wet-based tracer standard gas;

[0306] C 质原始 (tracer): the original volume concentration of the wet-based tracer standard gas obtained by the concentration analysis unit;

[0307] C 质控 (H 2 O): the humidity of the wet-based tracer standard gas obtained by the concentration analysis unit;

[0308] C 质标 (H 2 O): the released humidity of the wet-based tracer standard gas.

[0309] In one embodiment, the wet-based quality control standard gas is wet-based carbon dioxide or wet-based tracer standard gas.

[0310] Example

[0311] A certain power plant in Wuhan installed a set of CEMS for carbon emission monitoring. The diameter of the circular flue: 600 mm; flue gas temperature 0 °C; static pressure 0 Pa; humidity 8%; atmospheric pressure 101325 Pa.

[0312] According to the requirements of environmental protection standards, the sampling points were confirmed, the flanges and sampling probes were installed, and the tracing pipelines were connected to the acquisition unit. The release points were confirmed. After the dust removal process, at least 5 m upstream of the sampling point of the acquisition unit, the F6 release pipeline was installed and fixed, and the release flow rate was controlled at 11 mL / min.

[0313] Implementation method:

[0314] The acquisition unit continuously extracts flue gas, the concentration analysis unit continuously monitors the CO 2 concentration, the flow rate monitoring unit continuously monitors the temperature, pressure and flow rate of the flue gas, and the main control analysis unit calculates the final carbon dioxide emission.

[0315] Within 24 hours after the CEMS system starts monitoring, the first standard gas concentration quality control and flow rate quality control are carried out, the quality control coefficient is calculated, and the data obtained after the quality control is completed are valid data.

[0316] The quality control cycle frequency is as follows:

[0317] The quality control cycle for the standard gas concentration of the CEMS system is 7 days;

[0318] The quality control cycle for the moisture-containing standard gas of the CEMS system is 30 days;

[0319] The quality control cycle for the flow rate of the CEMS system is 30 days.

[0320] The CEMS system compares the trends of the directly measured carbon emission and gas consumption data every day. When the trend is abnormal, the quality control of the moisture-containing standard gas and flow rate is initiated.

[0321] CEMS system concentration range: CO 2 : 0 - 25%, SF 6 : 0 - 200 ppb.

[0322] CO 2 Standard gas concentration 25%; SF 6 Standard gas concentration: 200 ppb.

[0323] The CEMS concentration analysis unit monitors the CO 2 concentration and SF 6 concentration, and obtains the quality control coefficients from the main control analysis unit, denoted as C(CO 2 ), k(CO 2 ), b(CO 2 ), C(SF 6 ), k(SF 6 ), b(SF 6 ). The CEMS flow rate monitoring unit monitors the real-time flow velocity, denoted as v. The CEMS flow rate monitoring unit monitors the real-time flow velocity, denoted as v, and transmits it to the main control analysis unit to obtain the volume flow rate Q(v).

[0324] Within 24 hours after the CEMS starts monitoring, the first standard gas concentration quality control is carried out, including zero point and range quality control, and the quality control coefficients k(CO 2 ), b(CO 2 ), k(SF 6 ), b(SF 6 ) are calculated; the first wet-based standard gas concentration quality control is carried out, and the humidity quality control coefficient is calculated The first flow rate quality control is carried out, and the flow rate quality control coefficient k(v) is calculated.

[0325] Specifically, the quality control unit sequentially sends N 2 , CO 2 25% standard gas, SF 6 200 ppb standard gas, to the probe, through the heat tracing pipeline to the concentration analysis unit, and the concentration analysis unit monitors N2 Medium concentration result (C 质原始 (CO 2 ), C 质原始 (SF 6 ) are respectively: 0.01%, 0.25 ppb. The monitoring results of the CO 2 25% standard gas and the SF 6 200 ppb standard gas concentrations are respectively: 24.5%, 195 ppb. Then:

[0326] b(CO 2 ) = C 质标 (CO 2 ) - C 质原始 (CO 2 ) = 0 - 0.01 = -0.01;

[0327] b(SF 6 ) = C 质标 (SF 6 ) - C 质原始 (SF 6 ) = 0 - 0.25 = -0.25;

[0328] k(CO 2 ) = (C 质标 (CO 2 ) - b(CO 2 )) / C 质原始 (CO 2 ) = (25 + 0.01) / 24.5 = 1.02;

[0329] k(SF 6 ) = (C 质标 (SF 6 ) - b(SF 6 )) / C 质原始 (SF 6 ) = (200 + 0.25) / 195 = 1.03;

[0330] The quality control coefficient is updated and saved into the concentration analyzer, thereby obtaining the calibrated CO 2 concentration and SF 6 concentration in the flue gas sample.

[0331] Furthermore, the quality control unit sends a wet-based CO 2 standard gas with 8% humidity and 8.5% CO 2 to the probe of the collection unit at a rate of 3 L / min, through the heated pipeline to the concentration analysis unit. The concentration analysis unit monitors the concentration data (C 质原始 (CO 2 ) = 8%, k(CO 2 ) = 1.02, b(CO 2) = -0.01), calculate the humidity influence deviation coefficient Update and save to the concentration analysis unit. Then

[0332] b H2O (CO2) = (C 质标 (CO 2 ) - (k(CO 2 ) × C 质原始 (CO 2 ) + b(CO 2 ))) × C 质控 (H 2 O) / C i (H 2 O)

[0333] = (8.5 - (1.02 × 8 - 0.01)) × 8 / 8

[0334] = 0.35.

[0335] Furthermore, when the quality control unit has a wet-based SF tracer gas with 8% humidity and 100 ppb 6 The standard gas is transmitted to the probe of the collection unit at 3 L / min, through the heated pipeline to the concentration analysis unit, and the concentration analysis unit monitors the concentration data (C 质原始 (SF 6 ) = 97 ppb, k(SF 6 ) = 1.03, b(SF 6 ) = -0.25), calculate the humidity influence deviation coefficient Update and save to the concentration analysis unit. Then

[0336] b H2O (SF 6 ) = (C 质标 (SF 6 ) - (k(SF 6 ) × C 质原始 (SF 6 ) + b(SF 6 ))) × C 质控 (H 2 O) / C i (H 2 O)

[0337] = (100 - (1.03 × 97 - 0.25)) × 8 / 8

[0338] = 0.34.

[0339] Furthermore, calculate the flow quality control coefficient k(v) of the tracer gas SF 6 The tracer gas unit controls the release flow of the high-purity SF tracer gas: Q 6 x ​= 11 mL / min, released into the flue gas. After mixing, the tracer standard gas passes through the probe, the heated pipeline, and reaches the concentration analysis unit downstream of the flue gas. After stabilization, the average concentration of SF for 5 minutes is taken. 6 The average concentration is denoted as C. v2 = 100 ppb. The flow rate monitoring unit of the CEMS system takes the average flow rate for 5 minutes and is denoted as Calculate the flow rate quality control coefficient k(v). The updated quality control coefficient is saved to the industrial control computer of the system, and the release of the tracer standard gas is stopped.

[0340]

[0341]

[0342] Furthermore, calculate the emission of carbon dioxide in the flue gas emission stream. The CEMS system measures normally, extracts the flue gas, and based on the data of CO 2 in the flue gas sample monitored by the concentration analysis unit, the main control analysis unit calculates the hourly average concentration C i (CO 2 ) = 8.5%, the flow rate monitoring unit monitors the flow rate v data, the main control analysis unit calculates the hourly average value v = 6.5 m / s, and the main control analysis unit calculates the hourly carbon dioxide emission:

[0343]

[0344] Furthermore, perform zero point and full scale quality control every 7 days: The quality control unit opens the N 2 quality control standard gas and outputs 3 L / min N 2 , which is transmitted to the probe of the acquisition unit, passes through the heated pipeline, and reaches the concentration analysis unit. The concentration analysis unit monitors the concentration data and is denoted as Z n (CO 2 ) = 0.1, Z n (SF 6 ) = 0.5, the concentration range R of the CEMS system: CO 2 : 0 - 25%, SF 6 : 0 - 200 ppb. Calculate the zero point drift:

[0345]

[0346] Judge the quality control index: The zero point drift does not exceed ±3% FS. If it exceeds, zero point calibration is required, and b(CO 2 ), b(SF 6 ) need to be updated.

[0347] The quality control unit sequentially opens the 25% CO 2 quality control standard gas and outputs 3 L / min CO 2The quality control standard gas is transmitted to the probe of the acquisition unit, through the heated pipeline to the concentration analysis unit. The concentration analysis unit monitors the concentration data, denoted as S n (CO 2 ) = 25.2, the concentration range R of the CEMS system: CO 2 : 0 - 25%, calculate the span drift:

[0348]

[0349] Judge the quality control index: the span drift does not exceed ±3% FS. If it exceeds, span calibration is required to update k(CO 2 ).

[0350] The quality control unit sequentially opens the 200 ppb SF 6 quality control standard gas, outputs 3 L / min SF 6 The quality control standard gas is transmitted to the probe of the acquisition unit, through the heated pipeline to the concentration analysis unit. The concentration analysis unit monitors the concentration data, denoted as S n (SF 6 ) = 201.6, the concentration range R of the CEMS system: SF 6 : 0 - 200 ppb. Calculate the span drift:

[0351]

[0352] Judge the quality control index: the span drift does not exceed ±3% FS. If it exceeds, span calibration is required to update k(SF 6 ).

[0353] Furthermore, wet matrix quality control of the quality control standard gas is carried out every 30 d:

[0354] Obtain the 5 - minute average humidity of the flue gas emission flow, denoted as 8%, and the 5 - minute average CO 2 concentration, denoted as 8.5%.

[0355] The quality control unit generates a wet - based CO s (8.5%)CO 2 quality control standard gas with 8% humidity and C 2 is transmitted to the probe of the acquisition unit at 3 L / min, through the heated pipeline to the concentration analysis unit. The concentration analysis unit monitors the concentration data, denoted as C i (CO 2 ) = 8.3%, calculate the indication error:

[0356]

[0357] Judge the quality control index: the indication error does not exceed ±5%. If it exceeds, calibration is required to update the humidity influence deviation coefficient

[0358] The quality control unit controls the ratio to generate 8% humidity and C s (100 ppb) SF 6 Moist SF 6 Standard gas is transmitted to the probe of the acquisition unit at 3 L / min, through the heated pipeline to the concentration analysis unit. The concentration analysis unit monitors the concentration data, denoted as C i (SF 6 ) = 98 ppb, and the indication error is calculated as follows:

[0359]

[0360] Judge the quality control index: the indication error does not exceed ±5%. If it exceeds, calibration is required and the humidity influence deviation coefficient is updated

[0361] Furthermore, flow quality control is carried out every 30 days:

[0362] Obtain the 5-minute average value of the flue gas velocity of the flue gas emission flow, denoted as 6 m / s; obtain the volume flow rate of SF 6 released in the flue gas emission flow: Q x = 11 mL / min.

[0363] The quality control unit controls the release flow rate of the high-purity tracer gas SF 6 and outputs and releases it to the upstream of the flue at 11 mL / min. After dilution, it passes through the probe of the acquisition unit, through the heated pipeline to the concentration analysis unit. The concentration analysis unit monitors the concentration data, and after stabilization, the 5-minute average value is taken, denoted as C(SF 6 ) = 99 ppb, and the flow quality control coefficient k(v) is calculated. The quality control coefficient is updated and saved in the system industrial control computer, and the release of the tracer standard gas is stopped.

[0364]

[0365]

[0366] The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art. Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Direct carbon emission monitoring system based on CEMS, including: Tracer gas unit, used to measure the volume concentration C v1 and volume flow rate Q x Release the tracer gas upstream of the flue gas emission flow; a collection unit for collecting a flue gas sample downstream of the flue gas emission flow; The concentration analysis unit is used to obtain the volume concentration C of the tracer standard gas in the flue gas sample. v2 and the volume concentration of carbon dioxide C i (CO2); A flow monitoring unit, used for obtaining the volume flow Q(v) of the flue gas emission flow; The main control and analysis unit receives the volume flow Q x , the volume concentration C v1 and the volume concentration C v2 The volume flow rate Q of the tracer standard gas in the flue gas sample is obtained: In the formula, Q:m 3 / h;C v1 :%;C v2 :%;Q x :L / min; The volume flow rate Q(v) of the flue gas emission flow is received, and the flow quality control coefficient k(v) is obtained: Calculate the carbon dioxide emission G in the flue gas emission flow: G=C i (CO2)×44 / 22.4×10000×Q(v) / 1000000×k(v) In the formula, G:kg / h;Q(v):m 3 / h;C i (CO2):%。 2. According to the CEMS-based direct carbon emission monitoring system according to claim 1, the direct carbon emission monitoring system also includes a quality control unit, which is used to release quality control standard gas and guide it to the concentration analysis unit via the acquisition unit to obtain concentration information of the quality control standard gas. The main control analysis unit obtains the quality control coefficient based on the concentration information of the received quality control standard gas, and the quality control coefficient is used to calibrate the original concentration obtained by the concentration analysis unit.

3. According to the CEMS-based direct carbon emission monitoring system of claim 2, the quality control coefficients include a range quality control coefficient k, a zero point quality control coefficient b and a humidity quality control coefficient The range quality control coefficient k, the zero point quality control coefficient b and the humidity quality control coefficient The original concentration obtained by the concentration analysis unit is quality controlled: In the formula, C i : Monitor the volume concentration of gas; C 原始 : Volume concentration of the uncontrolled monitored gas obtained by the concentration analysis unit; C i (H2O): humidity of the monitoring gas obtained by the concentration analysis unit; C 质控 (H2O): Release humidity of quality control standard gas.

4. According to the CEMS-based direct carbon emission monitoring system of claim 3, the quality control standard gas comprises dry matrix control standard gas and wet matrix control standard gas; The dry basis control standard gas includes dry basis zero point standard gas and dry basis range standard gas.

5. According to the CEMS-based direct carbon emission monitoring system of claim 4, the dry basis zero point standard gas is used to obtain the zero point quality control coefficient b: The quality control unit releases the dry basis zero point standard gas, which is guided to the concentration analysis unit via the acquisition unit to obtain the concentration information of carbon dioxide or tracer standard gas in the dry basis zero point standard gas. The main control analysis unit obtains the zero point quality control coefficient b according to the received concentration information of carbon dioxide or tracer standard gas.

6. According to the CEMS-based direct carbon emission monitoring system of claim 4, the dry-based range standard gas is used to obtain the range quality control coefficient k: The quality control unit releases the dry basis range standard gas, which is guided to the concentration analysis unit via the acquisition unit to obtain concentration information of the dry basis range standard gas. The main control analysis unit obtains the range quality control coefficient k based on the received concentration information of the dry basis range standard gas.

7. According to the CEMS-based direct carbon emission monitoring system of claim 4, the wet matrix control standard gas is used to obtain the humidity quality control coefficient The quality control unit releases the wet matrix control standard gas, which is guided to the concentration analysis unit through the acquisition unit to obtain the concentration information of the wet matrix control standard gas. The main control analysis unit obtains the humidity quality control coefficient according to the received concentration information of the wet matrix control standard gas. In the formula, C 质标 : Release volume concentration of wet matrix control standard gas; C 质原始 : Volume concentration of wet matrix control standard gas obtained by concentration analysis unit; C 质控 (H2O): humidity of wet matrix control standard gas obtained by concentration analysis unit; C 质标 (H2O): Release humidity of wet matrix control standard gas.

8. Direct carbon emission monitoring methods based on CEMS, including: The tracer gas is added at a volume concentration of C v1 and volume flow rate Q x Release the tracer gas upstream of the flue gas emission flow; A flue gas sample is collected downstream of the flue gas emission flow, and a monitoring device is used to obtain the volume concentration C of the tracer standard gas in the flue gas sample. v2 and the volume concentration of carbon dioxide C i (CO2); The volume flow Q x , the volume concentration C v1 and the volume concentration C v2 The volume flow rate Q of the tracer standard gas in the flue gas sample is obtained: In the formula, Q:m 3 / h;C v1 :%;C v2 :%;Q x :L / min; The volume flow rate Q(v) of the flue gas emission flow is monitored, and the flow rate quality control coefficient k(v) is obtained by comparing it with the volume flow rate Q of the tracer standard gas: Calculate the carbon dioxide emission G in the flue gas emission flow: G=C i (CO2)×44 / 22.4×10000×Q(v) / 1000000×k(v) In the formula, G:kg / h;Q(v):m 3 / h;C i (CO2):%。 9. The direct carbon emission monitoring method based on CEMS according to claim 8, wherein the volume concentration C of carbon dioxide is i (CO2) and the volume concentration C of the tracer gas v2 The concentration after quality control: The quality control standard gas is released to the monitoring device to obtain the concentration information of the quality control standard gas, and the quality control coefficient is calculated by comparing it with the concentration of the quality control standard gas when released. The quality control coefficient is used to calibrate the original concentration obtained by the monitoring device to obtain the volume concentration C of the carbon dioxide. i (CO2) and the volume concentration C of the tracer gas v2 .

10. The direct carbon emission monitoring method based on CEMS according to claim 9, wherein the quality control coefficients include a range quality control coefficient k, a zero point quality control coefficient b and a humidity quality control coefficient The range quality control coefficient k, the zero point quality control coefficient b and the humidity quality control coefficient Quality control of the original concentration obtained by the monitoring device: In the formula, C i : Monitor the volume concentration of gas; C 原始 : Volume concentration of the uncontrolled monitored gas obtained by the concentration analysis unit; C i (H2O): humidity of the monitoring gas obtained by the concentration analysis unit; C 质控 (H2O): Release humidity of quality control standard gas.

Images