CEMS-based direct carbon emission monitoring system and method

Abstract

This application discloses a direct carbon emission monitoring system and method based on CEMS. The system releases tracer gas upstream of the flue gas emission stream via a tracer gas unit, collects flue gas samples downstream via a sampling unit, monitors the concentration of tracer gas in the samples via a concentration analysis unit, and calculates a flow control coefficient by combining this with the flue gas flow rate obtained from a flow monitoring unit, thereby accurately calculating carbon dioxide emissions. This method, based on the mass flow balance method, innovatively uses a moistened tracer gas, enabling direct and accurate measurement of CO2 concentration under moist flue gas conditions, thus improving the accuracy and efficiency of carbon emission monitoring.

Description

Technical Field

[0001] This application belongs to the field of carbon emission monitoring technology, and in particular relates to a direct carbon emission monitoring system and method based on CEMS. Background Technology

[0002] The background for carbon emission monitoring stems primarily from global concern about climate change and international action to address it. Scientific research shows that global climate change, caused by the massive burning of fossil fuels during industrialization and the resulting emissions of greenhouse gases such as carbon dioxide (CO2), is one of the most severe challenges facing humanity in the 21st century. Faced with this challenge, the international community has reached a broad consensus on reducing carbon emissions. To effectively address climate change and achieve the dual goals of economic growth and greenhouse gas emission reduction, the carbon emissions trading market, as an economic mechanism, has become a key tool for promoting greenhouse gas emission reduction and fostering the development of low-carbon technologies.

[0003] Currently, there are many domestic companies producing CO2-CEMS systems that directly measure carbon emissions. For CO2 concentration monitoring, the main technologies are NDIR and FTIR, which are well-established. For flue gas flow monitoring, technologies such as pitot tubes, ultrasonic sensors, and matrix flow meters are also mature. However, for carbon emission monitoring data used in carbon trading, the quality and traceability of CO2 concentration and flow data need to be guaranteed. Currently, there are no relevant solutions on the market regarding the quality assurance and traceability of emission data (especially flow data). Summary of the Invention

[0004] To address the issues of quality assurance and traceability of CO2 emission data (especially flow data) in existing direct measurement methods, this application aims to provide a CEMS system for directly measuring carbon dioxide emissions. This system replaces flow velocity monitoring with mass flow rate monitoring, reducing flow uncertainty, ensuring controllable data quality, and providing traceability.

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

[0006] The tracer gas unit is used to measure the volume concentration C. v1 and volumetric flow rate Q x Release tracer gas upstream of the flue gas emission stream;

[0007] A collection unit is used to collect flue gas samples downstream of the flue gas emission stream;

[0008] The concentration analysis unit is used to obtain the volume concentration C of the tracer standard gas in the flue gas sample. v2 and carbon dioxide volume concentration C i (CO2);

[0009] A flow monitoring unit is used to obtain the volumetric flow rate Q(v) of the flue gas emission stream;

[0010] The main control analysis unit receives the volumetric flow rate Q. x The volume concentration C v1 and the volume concentration C v2 The volumetric flow rate Q of the tracer standard gas in the flue gas sample was obtained:

[0011]

[0012] In the formula,

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

[0014] Receive the volumetric flow rate Q(v) of the flue gas emission stream, and obtain the flow quality control coefficient k(v):

[0015]

[0016] Calculate the carbon dioxide emissions in the flue gas stream:

[0017] G=C i (CO2)×44 / 22.4×10000×Q(v) / 1000000×k(v)

[0018] In the formula,

[0019] G: Carbon dioxide emissions in the flue gas stream, kg / h; Q(v): m³ / h 3 / h;C i (CO2): %.

[0020] In one embodiment, the tracer gas is selected from one of SF6, CO, Freon, and perfluoroisobutyronitrile.

[0021] In one embodiment, the direct carbon emission monitoring system further includes a quality control unit, which releases a quality control standard gas and guides it to the concentration analysis unit via the acquisition 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 the quality control coefficient is used to calibrate the original concentration obtained by the concentration analysis unit.

[0022] In one implementation, 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 are used to determine the range quality control coefficient k, the zero-point quality control coefficient b, and the humidity quality control coefficient b. The original concentration obtained by the concentration analysis unit of the quality control system:

[0023]

[0024] In the formula,

[0025] C i : Monitor the volume concentration of gases;

[0026] C 原始 Volume concentration of the monitoring gas obtained by the concentration analysis unit without quality control;

[0027] C i (H2O): Humidity of the monitored gas obtained by the concentration analysis unit;

[0028] C 质控 (H2O): Humidity released from the quality control standard gas.

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

[0030] In one embodiment, the dry basis control gas includes a dry basis zero-point control gas and a dry basis range control gas.

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

[0032] The quality control unit releases the dry-basis zero-point standard gas, which is guided by the acquisition unit to the concentration analysis unit to obtain the concentration information of carbon dioxide or tracer gas in the dry-basis 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 tracer gas.

[0033] In one embodiment, the dry-basis zero-point calibration gas is selected from nitrogen.

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

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

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

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

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

[0039]

[0040] In the formula,

[0041] C 质标 : Volumetric concentration of the controlled standard gas released from the wet matrix;

[0042] C 质原始 The volume concentration of the wet matrix control gas obtained from the concentration analysis unit;

[0043] C 质控 (H2O): Humidity of the wet matrix control gas obtained from the concentration analysis unit;

[0044] C 质标 (H2O): The release humidity of the control gas in the wet matrix.

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

[0046] In one embodiment, 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 dry matrix control standard gas to the acquisition unit, and the humidity generation module is used to receive the dry matrix control standard gas and generate the wet matrix control standard gas to release to the acquisition unit.

[0047] In one embodiment, the acquisition unit includes a sampling probe and a heat tracing line, the sampling probe being positioned downstream of the flue gas emission stream, and the heat tracing line being 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 via heated pipelines.

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

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

[0052] The tracer gas was prepared at a volume concentration of C. v1 and volumetric flow rate Q xRelease tracer gas upstream of the flue gas emission stream;

[0053] Flue gas samples were collected downstream of the flue gas emission stream, and the volume concentration C of the tracer gas in the flue gas samples was obtained using a monitoring device. v2 and the volume concentration of carbon dioxide C i (CO2);

[0054] Through the volumetric flow rate Q x The volume concentration C v1 and the volume concentration C v2 The volumetric flow rate Q of the tracer standard gas in the flue gas sample was obtained:

[0055]

[0056] In the formula,

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

[0058] The flow quality control coefficient k(v) is obtained by monitoring the volumetric flow rate Q(v) of the flue gas emission stream and the volumetric flow rate Q of the tracer gas:

[0059]

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

[0061] G=C i (CO2)×44 / 22.4×10000×Q(v) / 1000000×k(v)

[0062] In the formula,

[0063] G: Carbon dioxide emissions in the flue gas stream, kg / h; Q(v): m³ / h 3 / h;C i (CO2): %.

[0064] In one embodiment, the tracer gas is selected from one of SF6, CO, Freon, and perfluoroisobutyronitrile.

[0065] In one embodiment, the volume concentration C of the carbon dioxide i (CO2) and the volume concentration C of the tracer gas v2 Concentration after quality control:

[0066] A quality control standard gas is released into the monitoring device to obtain its concentration information. A quality control coefficient is calculated by comparing this concentration with the initial 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, thereby obtaining the volume concentration C of the carbon dioxide. i (CO2) and the volume concentration C of the tracer gas v2 .

[0067] In one implementation, 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 are used to determine the range quality control coefficient k, the zero-point quality control coefficient b, and the humidity quality control coefficient b. The original concentration obtained by the monitoring device for quality control:

[0068]

[0069] In the formula,

[0070] C i : Monitor the volume concentration of gases;

[0071] C 原始 Volume concentration of the monitoring gas obtained by the concentration analysis unit without quality control;

[0072] C i (H2O): Humidity of the monitored gas obtained by the concentration analysis unit;

[0073] C 质控 (H2O): Humidity released from the quality control standard gas.

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

[0075] In one embodiment, the dry basis control gas includes a dry basis zero-point control gas and a dry basis range control gas.

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

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

[0078] In one embodiment, the dry-basis zero-point calibration gas is selected from nitrogen.

[0079] In one implementation, the dry-basis range standard gas is used to obtain the range quality control coefficient k:

[0080] The dry-based standard gas is released into the monitoring device to obtain the concentration information of the standard gas and to analyze the range quality control coefficient k.

[0081] In one embodiment, the dry-basis range standard gas is carbon dioxide or a tracer standard gas.

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

[0083] The wet matrix control gas is released into the monitoring device to obtain the concentration information of the wet matrix control gas and to obtain the humidity quality control coefficient.

[0084]

[0085] In the formula,

[0086] C 质标 : Volumetric concentration of the controlled standard gas released from the wet matrix;

[0087] C 质原始 The volume concentration of the wet matrix control gas obtained from the concentration analysis unit;

[0088] C 质控 (H2O): Humidity of the wet matrix control gas obtained from the concentration analysis unit;

[0089] C 质标 (H2O): The release humidity of the control gas in the wet matrix.

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

[0091] The beneficial effects of this application are as follows:

[0092] This application innovatively employs the mass flow balance method. This method involves introducing a tracer gas upstream of the flue gas emission stream and accurately calculating the flue gas flow rate using the volumetric flow rate of the tracer gas downstream, the carbon dioxide concentration, and the volumetric flow rate of the flue gas emission stream. Its flow measurement process is unaffected by physical characteristics such as pipe shape, size differences, or uneven pipe diameter, nor is it influenced by piping conditions (e.g., bends, valves, etc.). Compared to traditional flow calculation methods based on velocity monitoring, this method significantly reduces the uncertainty in flow measurement, ensuring the accuracy and reliability of flow data. Furthermore, its traceability can be directly linked to the tracer standard gas, further enhancing the authority and credibility of the data.

[0093] This application employs a hot-wet method for monitoring carbon emissions. By controlling humidity, the wet basis concentrations of H2O, CO2, and SF6, as well as the wet flue gas flow rate, can be directly measured. This avoids the loss of monitoring component concentrations caused by the cold-drying method, eliminates the influence of H2O in emissions, and provides a more accurate measurement of carbon emissions while reducing uncertainty. Compared to traditional cold-drying monitoring techniques, the hot-wet method effectively avoids the loss of monitoring component concentrations due to gas condensation, thus ensuring the integrity of the measurement results. Furthermore, by accurately measuring and considering the influence of H2O concentration, the hot-wet method can more accurately calculate carbon emissions, further reducing uncertainty in the measurement process and improving the accuracy and scientific validity of the data. Attached Figure Description

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

[0095] Figure 2 This is a schematic diagram of the structure of the direct carbon emission monitoring system including the quality control unit in an embodiment of this application;

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

[0097] Figure 4 This is a schematic flowchart of the carbon emission monitoring method according to an embodiment of this application. Detailed Implementation

[0098] Hereinafter, exemplary embodiments according to this application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein.

[0099] Application Overview

[0100] The field of carbon emission monitoring still faces numerous challenges. Traditional carbon emission accounting techniques primarily rely on accounting methods. These methods estimate emissions by statistically analyzing carbon emissions generated from fossil fuel consumption and industrial production processes, using a series of complex conversion formulas and coefficients. However, the accuracy of this method is affected by various factors, such as the uncertainty of fuel type, combustion efficiency, and emission factors, leading to significant errors in the calculation results. Furthermore, accounting methods are susceptible to human interference, such as incomplete data recording and inconsistent statistical methods, further increasing the uncertainty of the results. This not only increases labor costs but also makes it difficult to accurately assess the actual effects of energy conservation and carbon reduction, limiting the formulation and implementation of carbon reduction strategies.

[0101] To overcome the limitations of traditional carbon emission control methods, direct measurement carbon emission monitoring (CEMS) has been introduced in existing technologies for real-time carbon emission monitoring. CEMS uses sensors installed at the emission source to measure the concentration of greenhouse gases such as CO2 in flue gas and the flue gas flow rate in real time, thereby calculating carbon emissions. However, CEMS still faces several challenges in practical applications. Firstly, flue gas flow rate data is easily affected by physical characteristics such as pipe shape, size, and diameter, as well as installation variations such as bends and valves, leading to insufficient assurance of data quality and traceability. Secondly, during direct real-time carbon emission monitoring, H2O in the flue gas significantly impacts the detection results, easily causing measurement deviations and further reducing data accuracy.

[0102] To address the problems existing in the prior art, this application proposes an innovative method for monitoring carbon emissions. This method employs a moist tracer standard gas and, based on the mass flow balance method, accurately calculates the flue gas flow rate by precisely measuring the ratio between the tracer concentration injected at the upper cross-section and the diluted tracer concentration at the downstream sampling cross-section.

[0103] Specifically, the mass flow balance method using tracer gas is employed. Tracer gas is introduced upstream of the flue gas emission stream, and the flue gas flow rate is accurately calculated by combining the volumetric flow rate of the tracer gas downstream of the emission stream with the carbon dioxide concentration and the volumetric flow rate of the flue gas emission stream. This ensures the traceability of flow data and eliminates the influence of physical characteristics such as pipe shape, size, and diameter, as well as installation conditions such as bends and valves, on flow measurement, achieving high-precision flue gas flow rate measurement. Furthermore, by controlling the humidity effect of downstream flue gas monitoring data, carbon emissions can be calculated more accurately. Compared to traditional accounting methods and CEMS direct measurement methods, the technical solution in this application achieves significant results in reducing uncertainty. By optimizing the measurement method and data processing flow, the uncertainty in the carbon emission monitoring process is successfully reduced, thereby improving the accuracy and scientific validity of the data. This breakthrough provides strong technical support for the effective monitoring and scientific management of carbon emissions.

[0104] Exemplary embodiments

[0105] In one embodiment of this application, such as Figure 1 As shown, a direct carbon emission monitoring system based on CEMS includes a tracer standard gas unit, a data acquisition unit, a concentration analysis unit, a flow monitoring unit, and a main control analysis unit.

[0106] The tracer gas unit is connected upstream of the flue gas emission stream via a transmission pipeline, and is used to measure the volume concentration C. v1 and volumetric flow rate Q xThe tracer gas is released upstream of the flue gas emission stream. The input of the acquisition unit is located downstream of the flue gas emission stream, and its output is connected to the concentration analysis unit via a transmission pipeline. This unit is used to collect flue gas samples downstream of the emission stream and transmit the collected 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 of the tracer gas in the flue gas sample by analyzing the received sample. v2 and carbon dioxide volume concentration C i (CO2) is collected and transmitted to the main control and analysis unit. The flow monitoring unit is installed on the flue gas emission stream and is signal-connected to the main control and analysis unit, transmitting the acquired volumetric flow rate Q(v) of the flue gas emission stream to the main control and analysis unit. The main control and analysis unit is signal-connected to the tracer gas unit, used to control the tracer gas unit to release the tracer gas, and to receive the volumetric concentration C of the tracer gas at the time of release. v1 and volumetric flow rate Q x The main control analysis unit, based on the volumetric flow rate Q x The volume concentration C v1 and the volume concentration C v2 The volumetric flow rate Q of the tracer gas in the flue gas sample is obtained through analysis. Then, the flow quality control coefficient k(v) is obtained by using the volumetric flow rate Q of the tracer gas and the volumetric flow rate Q(v) of the flue gas emission stream, thereby calculating the amount of carbon dioxide emitted in the flue gas emission stream.

[0107] Specifically, the control analysis unit receives the volumetric flow rate Q. x The volume concentration C v1 and the volume concentration C v2 The volumetric flow rate Q of the tracer gas in the flue gas sample was obtained from the analysis:

[0108]

[0109] In the formula,

[0110] Q: The volumetric flow rate of the tracer gas in the flue gas sample, in m³. 3 / h;

[0111] C v1 Volume concentration of tracer gas released, averaged over 5 minutes;

[0112] C v2 The volumetric concentration of the tracer gas obtained by the concentration analysis unit is the average value over 5 minutes.

[0113] Q x Volumetric flow rate during tracer gas release, averaged over 5 minutes, in L / min.

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

[0115]

[0116] The flow quality control coefficient k(v) is obtained by using the volumetric flow rate Q of the tracer gas and the volumetric flow rate Q(v) of the flue gas emission stream:

[0117]

[0118] Calculate the carbon dioxide emissions in the flue gas stream:

[0119] G=C i (CO2)×44 / 22.4×10000×Q(v) / 1000000×k(v)

[0120] In the formula,

[0121] G: Carbon dioxide emissions in the flue gas stream, kg / h;

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

[0123] C i (CO2): Volume concentration of carbon dioxide in the flue gas emission stream, %;

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

[0125] In this application, flue gas emission streams specifically refer to gaseous mixtures generated from various industrial processes, combustion equipment, or other emission sources and typically emitted into the atmosphere through chimneys. These mixtures contain a variety of gaseous components, including but not limited to carbon dioxide, carbon monoxide, nitrogen oxides, sulfur oxides, particulate matter, water vapor, and unburned hydrocarbons, and their composition, concentration, temperature, flow rate, and pressure vary depending on the type of emission source, operating conditions, fuel characteristics, and flue gas purification measures.

[0126] In this application, the terms "downstream" and "upstream" are used to describe the direction of flow of matter, energy, or information and their relative positions within a system, process, or apparatus. In a flue gas emission process, upstream refers to the area or component through which the flue gas first passes. Relative to upstream, downstream refers to the area or component to which the flue gas continues its flow after passing through the upstream area or component. Furthermore, in a flue gas emission process, the flow direction of the flue gas is from upstream to downstream. This directionality is reflected not only in physical space but also in the logical sequence of processing steps. Upstream treatment is the prerequisite and foundation for downstream treatment, while downstream treatment further optimizes and ensures the results of upstream treatment.

[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 typically stored in high-pressure cylinders that comply with relevant safety standards (such as ISO, GB, etc.) and are equipped with pressure reducing valves to control the gas release pressure. The flow controller precisely controls the release flow rate of the tracer gas, ensuring it enters the flue gas emission stream at a set volumetric flow rate. The flow controller is connected to the output of the tracer gas source, and its output is connected upstream of the flue gas emission stream via a transmission line. The flow controller is also signal-connected to the main control and analysis unit to output the volumetric concentration C of the tracer gas at the time of release. v1 and volumetric flow rate Q x The data is transmitted to the main control analysis unit.

[0128] The tracer gas is selected from gases that are present in small amounts in the flue gas and have good diffusivity.

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

[0130] Preferably, the tracer gas is selected from sulfur hexafluoride (SF6). SF6 is an ideal tracer gas due to its unique physical and chemical properties, such as chemical stability, low reactivity, resistance to chemical reactions with other substances, and high sensitivity under specific detection methods. When SF6 mixes with flue gas and is released into the environment, it diffuses along with the flow of the flue gas and can be detected with high sensitivity under specific detection methods. By tracking changes in SF6 concentration, the flow path, velocity, and diffusion range of the flue gas can be indirectly reflected, thereby analyzing the distribution and concentration changes of carbon dioxide.

[0131] After release, the tracer gas needs to be thoroughly mixed with the flue gas to ensure a representative flue gas sample is obtained at the collection point. If the release point is too close to the collection point, it may cause a high concentration area of ​​tracer gas in a localized area, while the concentration in other areas is relatively low. This situation will seriously affect the accuracy and reliability of the flue gas sample. Therefore, it is necessary to control the distance between the tracer gas release point and the flue gas sample collection point.

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

[0133] In some embodiments, the flow monitoring unit calculates the volumetric flow rate of the flue gas by measuring its velocity. Specifically, it employs Doppler radar technology, using a radar sensor to transmit and receive microwave signals, and calculates the flue gas velocity by measuring the frequency change of the microwave signals; or ultrasonic technology, using an ultrasonic sensor to transmit and receive ultrasonic signals, and calculates the flue gas velocity by measuring the change in signal propagation time; or a thermal flow meter, using a hot wire or hot film sensor to measure the flue gas velocity. When the flue gas flows past the sensor, it carries away heat, and the flow rate can be calculated by measuring the change in heat.

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

[0135]

[0136] In the formula,

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

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

[0139] v: The velocity of the flue gas emission stream, taken as the 5-minute average, in 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 flue gas in the flue gas emission stream, Pa.

[0143] In some embodiments, the flow monitoring unit is located near the acquisition port of the acquisition unit to ensure that the monitored flow data and the acquired flue gas sample data are consistent in time and space, thereby reducing [the risk of contamination].

[0144] In some embodiments, the acquisition unit includes a sampling probe, a sampling rod, and a heating line. The sampling probe is connected to one end of the sampling rod via a sealed connector; this connection is typically designed to be detachable for easy maintenance and replacement of the sampling probe. The sampling rod supports and transports the flue gas sample, ensuring no leakage occurs during acquisition. The other end of the sampling rod is connected to the inlet of the heating line, transferring the acquired flue gas sample to the heating line for heating to prevent water vapor in the flue gas from condensing during transport, thus avoiding interference with subsequent analysis. The outlet of the heating line is connected to the concentration analysis unit, such as the inlet of a Fourier Transform Infrared (FTIR) gas analyzer, to deliver the heated flue gas sample to the analyzer for detection. In practical applications, the acquisition unit may also include other auxiliary components, such as flow meters, pressure reducing valves, and filters, for further control and optimization of the flue gas sample acquisition and transport process. To reduce the impact of impurities in the flue gas sample (such as dust, oil mist, and particulate matter) on the detection results, the sampling probe is equipped with a device specifically for filtering particulate matter. This filtration device is typically a combination of one or more filter elements. Depending on the required filtration precision and efficiency, different types of filter materials can be selected, such as glass fiber, ceramics, metal mesh, and polymer membranes. The filtration 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 heat tracing pipeline includes an inner gas path pipe, an electric heating tape, a heat insulation layer, a thermal insulation layer, and an outer protective sleeve. The inner gas path pipe is the core part of the heat tracing pipeline and is used to transport the medium requiring heat preservation or heating, such as the humidified tracer gas. The electric heating tape is wrapped around the gas path pipe and provides heating. Based on their working principle, electric heating tapes can be divided into self-regulating and constant-power types. Self-regulating electric heating tapes have limited heating temperatures, while constant-power electric heating tapes can adjust their heating temperature using a temperature controller. The heat insulation layer is located outside the electric heating tape and is used to reduce heat loss and improve the heat preservation effect. The thermal insulation layer is located outside the heat insulation layer and further provides heat preservation, ensuring the overall heat preservation performance of the heat tracing pipeline. The outer protective sleeve, as the outermost layer of the heat tracing pipeline, provides mechanical protection and shielding against damage from the external environment.

[0146] In some embodiments, the concentration analysis unit is used for online monitoring of the tracer standard gas volume concentration C in the flue gas sample. v2 and carbon dioxide volume concentration C i(CO2) is detected and the data is fed back to the main control and analysis unit. The type of concentration sensor is selected based on the characteristics of the tracer gas, such as an infrared absorption spectrometer, electrochemical sensor, or mass spectrometer, to ensure that the measurement accuracy and response speed meet application requirements. Specifically, the concentration analysis unit uses a Fourier transform infrared (FTIR) gas analyzer. The detection process first utilizes an infrared light source to emit broad-spectrum infrared radiation, and then introduces the pretreated flue gas sample into the sample cell of the FTIR analyzer. In the sample cell, infrared light of specific wavelengths is absorbed by the tracer gas and carbon dioxide molecules, resulting in a decrease in the intensity of infrared radiation. This decrease is converted into an interference pattern by an interferometer and recorded by a detector. Next, a Fourier transform algorithm is used to mathematically transform the interference pattern, converting it into an easily interpretable spectrum. In the spectrum, the absorption peaks of the moist tracer gas and carbon dioxide can be identified, and by measuring the intensity of these absorption peaks and applying Beer-Lambert's law, the concentrations of these two gases in the flue gas sample can be determined.

[0147] In the application, the main control analysis unit specifically refers to a core device that integrates 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 tracer gas unit to accurately release the tracer gas, but also receives and analyzes data from the concentration analysis unit and the flow detection unit, and then performs complex calculations to obtain key parameters such as the flow rate of the flue gas emission stream and the amount of carbon dioxide emissions.

[0148] In some embodiments, the main control and analysis unit serves as the "brain" of the entire system, comprising a central processing unit (CPU), a data acquisition module, a communication interface, a storage module, and a power supply module. These hardware components are integrated to form a complete main control and analysis unit. The CPU is selected from industrial-grade processors, such as those found in embedded industrial control boards or PLCs (Programmable Logic Controllers), supporting floating-point operations and multi-threaded processing to improve data processing capabilities and response speed. The data acquisition module includes a multi-channel analog input module for receiving analog signals from sensors (e.g., 4-20mA or 0-10V); a digital input module for receiving pulse signals or other digital signals; and an RS485 communication interface for communicating with external devices (e.g., gas analyzers, flow meters). The communication interface can be an Ethernet interface supporting Modbus TCP / IP protocol for communication with a monitoring center or remote server; or a wireless communication module (e.g., 4G / LTE) for wireless data transmission. The storage module can be industrial-grade memory, such as a solid-state drive (SSD) or flash memory card. The power module has a wide voltage input range (e.g., 100-240V AC) to adapt to power conditions in different regions, and also has a built-in battery backup module to ensure that data is not lost in the event of a power outage.

[0149] In another embodiment of this application, such as Figure 2 As shown, a direct carbon emission monitoring system based on CEMS includes a tracer gas unit, a data acquisition unit, a concentration analysis unit, a flow monitoring unit, a main control analysis unit, and a quality control unit. The data acquisition unit is used to collect flue gas samples downstream of the flue gas emission stream; the concentration analysis unit is used to obtain the volume concentration C of the tracer gas in the flue gas sample. v2 and carbon dioxide volume concentration C i (CO2); Flow monitoring unit, used to acquire the volumetric flow rate Q(v) of the flue gas emission stream; Main control and analysis unit, receiving the volumetric flow rate Q x The volume concentration C v1 and the volume concentration C v2 The volumetric flow rate Q of the tracer gas in the flue gas sample is obtained by analysis, the volumetric flow rate Q(v) of the flue gas emission stream is received, the flow quality control coefficient k(v) is obtained, and the carbon dioxide emission in the flue gas emission stream is calculated.

[0150] The quality control unit includes a quality control standard gas source, which is connected to the input end of the acquisition unit via a heated pipeline, such as a sampling probe. The quality control standard gas source releases quality control standard gas, which is guided by the acquisition unit to the concentration analysis unit to obtain the concentration information of the quality control standard gas. The main control analysis unit receives the concentration information of the quality control standard gas and calculates and analyzes a quality control coefficient, which is used to calibrate the original concentration obtained by the concentration analysis unit. The quality control standard gas source is usually stored in a high-pressure cylinder. The 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, to control the release flow rate of the quality control standard gas, the output end of the quality control standard gas source is connected to a flow controller for precisely controlling the release flow rate of the quality control standard gas, ensuring that it enters the acquisition unit at a set flow rate. The output end of the flow controller is connected to the acquisition unit via a heat tracing pipeline, and the flow controller is signal-connected to the main control analysis unit for transmitting 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 dry matrix control standard gas and wet matrix control standard gas.

[0153] In this application, dry matrix control standard gas refers to a quality control standard gas that has undergone special treatment under certain conditions (such as temperature and pressure) to remove or significantly reduce its moisture content. Its characteristic is that the moisture content in the gas is extremely low, typically below a preset threshold (such as extremely low dew point temperature or relative humidity close to zero), to ensure the stability of the gas composition and the accuracy of measurement. This includes, but is not limited to, single or mixed gases such as nitrogen, oxygen, carbon dioxide, and tracer gases after drying.

[0154] In this application, wet matrix control gas refers to a quality control standard gas containing a certain amount of moisture, the moisture content of which is precisely controlled according to specific application requirements. Examples include humidified nitrogen, oxygen, carbon dioxide, and tracer gas.

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

[0156] In some embodiments, 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 by the acquisition unit to the concentration analysis unit to obtain the concentration information of carbon dioxide or tracer gas in the dry-basis 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 gas.

[0157] Specifically, the zero-point quality control coefficient b(CO2) for carbon dioxide is:

[0158] b(CO2)=C 质标 (CO2)-C 质原始 (CO2)

[0159] In the formula,

[0160] C 质标 (CO2): The volume concentration of carbon dioxide in the dry basis zero-point standard gas, where the dry basis zero-point standard gas is a non-carbon dioxide gas.

[0161] C 质原始 (CO2): The original volume concentration of carbon dioxide in the dry-basis zero-point standard gas obtained by the concentration analysis unit.

[0162] Since the dry-basis zero-point standard gas is a non-carbon dioxide gas, and the volume concentration of carbon dioxide in the dry-basis zero-point standard gas is 0, the zero-point quality control coefficient b(CO2) is:

[0163] b(CO2) = 0 - C 质原始 (CO2).

[0164] The zero-point quality control coefficient b (tracer) for the tracer gas is:

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

[0166] In the formula,

[0167] C 质标 (Tracer): The volume concentration of tracer gas in dry-basis zero-point standard gas, where dry-basis zero-point standard gas is a non-tracer gas.

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

[0169] Since the quality control standard gas is a non-tracer standard gas, and the volume concentration of the tracer standard gas in the quality control standard gas is 0, the zero-point quality control coefficient b (tracer) is:

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

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

[0172] In some embodiments, the dry-based range standard gas is used to obtain the range quality control coefficient k: the quality control unit releases the dry-based range standard gas, which is guided to the concentration analysis unit by the acquisition unit to obtain the concentration information of the dry-based range standard 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 standard gas.

[0173] The range control coefficient k(CO2) for carbon dioxide uses the same dry basis zero-point standard gas, that is, when controlling the range control coefficient for carbon dioxide, the dry basis zero-point standard gas is carbon dioxide gas.

[0174] Therefore, the range control coefficient k(CO2) for carbon dioxide is:

[0175] k(CO2)=(C 质标 (CO2)-b(CO2)) / C 质原始 (CO2)

[0176] In the formula,

[0177] C 质标 (CO2): Volume concentration of carbon dioxide standard gas released on a dry basis;

[0178] b(CO2): Zero-point quality control coefficient for carbon dioxide;

[0179] C 质原始 (CO2): The original volume concentration of the dry-basis range standard gas obtained by the concentration analysis unit.

[0180] The range control coefficient k (tracer) of the tracer standard gas uses the same dry basis zero point standard gas. That is, when the range control coefficient of the tracer standard gas is controlled, the dry basis zero point standard gas is the same gas as the tracer standard gas.

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

[0182] k(tracer) = (C 质标 (Tracer) - b(Tracer)) / C 质原始 (Tracing)

[0183] In the formula,

[0184] C 质标 (Tracer): The volume concentration of the tracer gas when it is released;

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

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

[0187] The zero-point quality control coefficient b(CO2), zero-point quality control coefficient b(tracer), range quality control coefficient k(CO2), and range quality control coefficient k(tracer) are updated to the concentration analysis unit.

[0188] Due to the humidity of the dry matrix control gas C i (H2O) is 0. When the dry matrix control gas is carbon dioxide, the original volume concentration of carbon dioxide in the flue gas sample obtained by the concentration analysis unit is calibrated:

[0189]

[0190] =k(CO2)×C 原始 (CO2)+b(CO2)+0

[0191] =k(CO2)×C 原始 (CO2)+b(CO2)

[0192] In the formula,

[0193] C 原始 (CO2): The uncalibrated raw volume concentration of the dry matrix carbon dioxide control gas obtained by the concentration analysis unit;

[0194] C i (H2O): Humidity of the carbon dioxide dry matrix control gas obtained by the concentration analysis unit;

[0195] C 质控 (H2O): Humidity of carbon dioxide release from the dry matrix control gas;

[0196] Humidity quality control coefficient of carbon dioxide dry matrix control gas.

[0197] Due to the humidity of the dry matrix control gas C i (H2O) is 0. When the dry matrix control gas is used as the tracer gas, the original volume concentration of the dry matrix control gas obtained by the concentration analysis unit is calibrated:

[0198]

[0199] = k(tracer) × C 原始 (Tracer) + b(Tracer) + 0

[0200] = k(tracer) × C 原始 (Tracer) + b(Tracer)

[0201] In the formula,

[0202] C 原始 (Tracer): The uncalibrated raw volume concentration of the tracer quality control standard gas obtained by the concentration analysis unit;

[0203] C i (H2O): Humidity of the tracer dry matrix control gas obtained by the concentration analysis unit;

[0204] C 质控 (H2O): The humidity of the control gas released from the tracer dry matrix;

[0205] Humidity quality control coefficient of tracer dry matrix control gas.

[0206] In some embodiments, the wet matrix control gas is used to obtain the humidity quality control coefficient.

[0207] The quality control unit releases the wet matrix control gas, which is guided by the acquisition unit to the concentration analysis unit to obtain the concentration information of the wet matrix control gas. The main control analysis unit obtains the humidity quality control coefficient based on the received concentration information of the wet matrix control gas.

[0208] The wet matrix control gas is a wet-based carbon dioxide standard gas or a wet-based tracer standard gas.

[0209] When the wet matrix control gas is wet-based carbon dioxide control gas, the humidity control coefficient of carbon dioxide is... for:

[0210] Depend on

[0211] Derivation:

[0212]

[0213] In the formula,

[0214] C 质标 (CO2): Volumetric concentration of wet-based carbon dioxide standard gas released;

[0215] C 质原始 (CO2): The original volume concentration of wet-based carbon dioxide standard gas obtained from the concentration analysis unit;

[0216] C 质控 (H2O): The humidity of the wet-based carbon dioxide standard gas obtained from the concentration analysis unit;

[0217] C 质标 (H2O): The release humidity of wet-based carbon dioxide standard gas.

[0218] When the wet matrix control gas is the wet matrix tracer quality control gas, then the humidity control coefficient of the tracer gas is... for:

[0219] Depend on

[0220] Derivation:

[0221]

[0222] In the formula,

[0223] C 质标 (Tracer): The volumetric concentration of the released wet-based tracer standard gas;

[0224] C 质原始 (Tracer): The original volume concentration of the wet-based tracer standard gas obtained by the concentration analysis unit;

[0225] C 质控 (H2O): The humidity of the wet-based tracer gas obtained from the concentration analysis unit;

[0226] C 质标 (H2O): The release humidity of the wet-based tracer gas.

[0227] In some embodiments, such as Figure 3As shown, the quality control unit includes a quality control standard gas module and a humidity generation module. The quality control standard gas module releases the quality control standard gas to the acquisition unit, and the humidity generation module receives the quality control standard gas and generates the wet matrix control standard gas, which is then released to the acquisition 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, which is connected to both the acquisition unit and the humidity generation module via multi-port valves. The humidity generation module receives the quality control standard gas and generates the wet matrix control standard gas. To achieve real-time and precise control of the wet matrix control standard gas, temperature and humidity sensors can be installed on the output pipeline of the humidity generation module. These sensors are connected to the main control and analysis unit via signal lines, transmitting the real-time monitored temperature and humidity parameters to the main control and analysis unit. Based on the feedback signals from the sensors, the main control and analysis unit adjusts the outputs of the flow controller and the humidity generation module to maintain the concentration and humidity of the wet matrix control standard gas within a preset range.

[0228] In another embodiment of this application, such as Figure 4 As shown, a direct carbon emission monitoring method based on CEMS is provided, including the following steps:

[0229] The tracer gas was prepared at a volume concentration of C. v1 and volumetric flow rate Q x Release tracer gas upstream of the flue gas emission stream;

[0230] Flue gas samples were collected downstream of the flue gas emission stream, and the volume concentration C of the tracer standard gas in the flue gas samples was obtained using a monitoring device. v2 and carbon dioxide volume concentration C i (CO2);

[0231] Through the volumetric flow rate Q x The volume concentration C v1 and the volume concentration C v2 Analysis yielded the volumetric flow rate Q(SF6) of the tracer gas in the flue gas sample:

[0232]

[0233] In the formula,

[0234] Q(SF6): m 3 / h;C v1 :%; C v2 Take the 5-minute average, %; Q x : L / min;

[0235] The flow quality control coefficient k(v) is obtained by monitoring the volumetric flow rate Q(v) of the flue gas emission stream and the volumetric flow rate Q(SF6) of the tracer gas:

[0236]

[0237] Calculate the carbon dioxide emissions in the flue gas stream:

[0238] G=C i (CO2)×44 / 22.4×10000×Q(v) / 1000000×k(v)

[0239] In the formula,

[0240] G: Carbon dioxide emissions in the flue gas sample, kg / h; Q(v): m 3 / h;C i (CO2): %.

[0241] In one embodiment, the tracer gas is selected from one of SF6, CO, Freon, and perfluoroisobutyronitrile.

[0242] In one embodiment, the carbon dioxide volume concentration C monitored in the flue gas sample i (CO2) and tracer gas volume concentration C v2 Perform quality control:

[0243] The quality control standard gas is released into the monitoring device to obtain the concentration information of the quality control standard gas. The quality control coefficient is obtained by comparing it 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.

[0244] In one implementation, 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 are used to determine the range quality control coefficient k, the zero-point quality control coefficient b, and the humidity quality control coefficient b. The original concentration obtained by calibrating the monitoring device:

[0245]

[0246] In the formula,

[0247] C i : Volume concentration of carbon dioxide or tracer gas in the calibrated flue gas sample;

[0248] C 原始 The uncalibrated volume concentration of carbon dioxide or tracer gas in the flue gas sample obtained by the monitoring device;

[0249] C i(H2O), the humidity of the flue gas sample acquired by the monitoring device;

[0250] C 质控 (H2O), the humidity of the released quality control standard gas.

[0251] In one embodiment, the quality control standard gas includes dry matrix control standard gas and wet matrix control standard gas.

[0252] In one embodiment, the dry basis control gas includes a dry basis zero-point control gas and a dry basis range control gas.

[0253] In one implementation, the dry-basis zero-point standard gas is used to obtain the zero-point quality control coefficient b:

[0254] Release the dry-based zero-point standard gas into the monitoring device, obtain the concentration information of carbon dioxide or tracer gas in the dry-based zero-point standard gas, and analyze to obtain the zero-point quality control coefficient b.

[0255] Specifically, the zero-point quality control coefficient b(CO2) for carbon dioxide is:

[0256] b(CO2)=C 质标 (CO2)-C 质原始 (CO2)

[0257] In the formula,

[0258] C 质标 (CO2): The volume concentration of carbon dioxide in the dry basis zero-point standard gas, where the dry basis zero-point standard gas is a non-carbon dioxide gas.

[0259] C 质原始 (CO2): The original volume concentration of carbon dioxide in the dry-basis zero-point standard gas obtained by the concentration analysis unit.

[0260] Since the dry-basis zero-point standard gas is a non-carbon dioxide gas, and the volume concentration of carbon dioxide in the dry-basis zero-point standard gas is 0, the zero-point quality control coefficient b(CO2) is:

[0261] b(CO2) = 0 - C 质原始 (CO2).

[0262] The zero-point quality control coefficient b (tracer) for the tracer gas is:

[0263] b (tracer) = C 质标 (Tracer) - C 质原始 (Tracing)

[0264] In the formula,

[0265] C 质标 (Tracer): The volume concentration of tracer gas in dry-basis zero-point standard gas, where dry-basis zero-point standard gas is a non-tracer gas.

[0266] C 质原始 (Tracer): The original volume concentration of tracer standard gas in dry basis zero-point standard gas obtained by the concentration analysis unit;

[0267] Since the quality control standard gas is a non-tracer standard gas, and the volume concentration of the tracer standard gas in the quality control standard gas is 0, the zero-point quality control coefficient b (tracer) is:

[0268] b(tracer) = 0 - C 质原始 (Tracing).

[0269] In one embodiment, the dry-basis zero-point calibration gas is selected from nitrogen.

[0270] In one implementation, the dry-basis range standard gas is used to obtain the range quality control coefficient k:

[0271] The dry-based standard gas is released into the monitoring device to obtain the concentration information of the standard gas and to analyze the range quality control coefficient k.

[0272] Specifically, the dry basis zero-point standard gas used for the range control coefficient k(CO2) of carbon dioxide is the same as that used for it. That is, when controlling the range control coefficient of carbon dioxide, the dry basis zero-point standard gas is carbon dioxide gas.

[0273] Therefore, the range control coefficient k(CO2) for carbon dioxide is:

[0274] k(CO2)=(C 质标 (CO2)-b(CO2)) / C 质原始 (CO2)

[0275] In the formula,

[0276] C 质标 (CO2): Volume concentration of carbon dioxide standard gas released on a dry basis;

[0277] b(CO2): Zero-point quality control coefficient for carbon dioxide;

[0278] C 质原始 (CO2): The original volume concentration of the dry-basis range standard gas obtained by the concentration analysis unit.

[0279] The range control coefficient k (tracer) of the tracer standard gas uses the same dry basis zero point standard gas. That is, when the range control coefficient of the tracer standard gas is controlled, the dry basis zero point standard gas is the same gas as the tracer standard gas.

[0280] Then, the range control coefficient k(tracer) of the tracer gas is:

[0281] k(tracer) = (C 质标 (Tracer) - b(Tracer)) / C质原始 (Tracing)

[0282] In the formula,

[0283] C 质标 (Tracer): The volume concentration of the tracer gas when it is released;

[0284] b (tracer): Zero-point quality control coefficient of tracer gas;

[0285] C 质原始 (Tracer): The original volume concentration of the tracer standard gas obtained by the concentration analysis unit.

[0286] In one embodiment, the dry-basis range standard gas is carbon dioxide or a tracer standard gas.

[0287] In one embodiment, the wet matrix control gas is used to obtain the humidity quality control coefficient.

[0288] The wet matrix control gas is released into the monitoring device to obtain the concentration information of the wet matrix control gas and to analyze the humidity quality control coefficient.

[0289]

[0290] In the formula,

[0291] C 质标 : Volumetric concentration of the controlled standard gas released from the wet matrix;

[0292] C 质原始 The volume concentration of the wet matrix control gas obtained from the concentration analysis unit;

[0293] C 质控 (H2O): Humidity of the wet matrix control gas obtained from the concentration analysis unit;

[0294] C 质标 (H2O): The release humidity of the control gas in the wet matrix.

[0295] Specifically, when the wet matrix control gas is wet-based carbon dioxide control gas, the humidity control coefficient of carbon dioxide is... for:

[0296] Depend on

[0297] Derivation:

[0298]

[0299] In the formula,

[0300] C 质标 (CO2): Volumetric concentration of wet-based carbon dioxide standard gas released;

[0301] C 质原始 (CO2): The original volume concentration of wet-based carbon dioxide standard gas obtained from the concentration analysis unit;

[0302] C 质控 (H2O): The humidity of the wet-based carbon dioxide standard gas obtained from the concentration analysis unit;

[0303] C 质标 (H2O): The release humidity of wet-based carbon dioxide standard gas.

[0304] When the wet matrix control gas is the wet matrix tracer quality control gas, then the humidity control coefficient of the tracer gas is... for:

[0305] Depend on

[0306] Derivation:

[0307]

[0308] In the formula,

[0309] C 质标 (Tracer): The volumetric concentration of the released wet-based tracer standard gas;

[0310] C 质原始 (Tracer): The original volume concentration of the wet-based tracer standard gas obtained by the concentration analysis unit;

[0311] C 质控 (H2O): The humidity of the wet-based tracer gas obtained from the concentration analysis unit;

[0312] C 质标 (H2O): The release humidity of the wet-based tracer gas.

[0313] In one embodiment, the wet matrix control gas is wet-based carbon dioxide or wet-based tracer gas.

[0314] Example

[0315] A power plant in Wuhan installed a CEMS (Carbon Emission Monitoring System) for carbon emission monitoring. The system features a circular flue diameter of 600mm, flue gas temperature of 0℃, static pressure of 0Pa, humidity of 8%, and atmospheric pressure of 101325Pa.

[0316] According to environmental protection standards, confirm the sampling point, install the flange and sampling probe, and connect the heat tracing pipeline to the collection unit. Confirm the release point, at least 5m upstream of the sampling point of the collection unit after the dust removal process, install and fix the F6 release pipeline, and control the release flow rate at 11mL / min.

[0317] Implementation method:

[0318] The acquisition unit extracts flue gas in real time, the concentration analysis unit monitors CO2 concentration in real time, the flow monitoring unit monitors the temperature, pressure and flow rate of flue gas in real time, and the main control analysis unit calculates the final carbon dioxide emissions.

[0319] Within 24 hours of the CEMS system startup, initial standard gas concentration and flow rate quality control are performed, and the quality control coefficient is calculated. Data from subsequent monitoring is considered valid.

[0320] The quality control cycle frequency is:

[0321] The standard gas concentration quality control cycle of the CEMS system is 7 days.

[0322] The CEMS system, including the humidity standard gas quality control cycle, has a 30-day cycle.

[0323] The flow quality control cycle of the CEMS system is 30 days.

[0324] The CEMS system compares the trends of directly measured carbon emissions and gas consumption data every day. When the trend is abnormal, it initiates quality control of the humid standard gas and flow rate.

[0325] CEMS system concentration range: CO2: 0-25%, SF6: 0-200 ppb.

[0326] CO2 standard gas concentration: 25%; SF6 standard gas concentration: 200 ppb.

[0327] The CEMS concentration analysis unit monitors CO2 and SF6 concentrations and obtains quality control coefficients from the main control analysis unit, denoted as C(CO2), k(CO2), b(CO2), C(SF6), k(SF6), and b(SF6), respectively. The CEMS flow monitoring unit monitors the real-time flow rate, denoted as v, and transmits it to the main control analysis unit to obtain the volumetric flow rate Q(v).

[0328] Within 24 hours of CEMS startup monitoring, conduct the initial standard gas concentration quality control, including zero-point and range quality control, and calculate the quality control coefficients k(CO2), b(CO2), k(SF6), and b(SF6); conduct the initial wet-based standard gas concentration quality control, and calculate the humidity quality control coefficient. For the first flow quality control, calculate the flow quality control coefficient k(v).

[0329] Specifically, the quality control unit sequentially generates N2, 25% CO2 standard gas, and 200ppb SF6 standard gas, which are then sent to the probe and via a heated pipeline to the concentration analysis unit. The concentration analysis unit monitors the N2 concentration results (original CO2 and original SF6) at 0.01% and 0.25ppb, respectively, and the CO2 25% standard gas and SF6 200ppb standard gas concentration results at 24.5% and 195ppb, respectively. Therefore:

[0330] b(CO2)=C 质标 (CO2)-C 质原始 (CO2) = 0 - 0.01 = -0.01;

[0331] b(SF6)=C 质标 (SF6)-C 质原始 (SF6) = 0 - 0.25 = -0.25;

[0332] k(CO2)=(C 质标 (CO2)-b(CO2)) / C 质原始 (CO2)=(25+0.01) / 24.5=1.02;

[0333] k(SF6)=(C 质标 (SF6)-b(SF6)) / C 质原始 (SF6))=(200+0.25) / 195=1.03;

[0334] The quality control coefficients are updated and saved to the concentration analyzer, thus obtaining the calibrated CO2 and SF6 concentrations in the flue gas sample.

[0335] Furthermore, the quality control unit generates a wet-based CO2 standard gas with 8% humidity and 8.5% CO2, which is transmitted at a rate of 3 L / min to the probe of the acquisition unit, and then through a heated pipeline to the concentration analysis unit. The concentration analysis unit monitors the concentration data (C). 质原始 Given (CO2) = 8%, k(CO2) = 1.02, b(CO2) = -0.01, calculate the humidity effect deviation coefficient. Update and save to the concentration analysis unit.

[0336] b H2O (CO2)=(C 质标 (CO2)-(k(CO2)×C 质原始 (CO2)+b(CO2)))×C 质控 (H2O) / C i (H2O)

[0337] = (8.5 - (1.02 × 8 - 0.01)) × 8 / 8

[0338] =0.35.

[0339] Furthermore, the quality control unit generates 8% humidity, 100 ppb wet-based SF6 standard gas at 3 L / min, which is transmitted to the probe of the acquisition unit and then via a heated pipeline to the concentration analysis unit. The concentration analysis unit monitors the concentration data (C). 质原始 Given SF6 = 97 ppb, k(SF6) = 1.03, b(SF6) = -0.25, calculate the humidity influence deviation coefficient. Update and save to the concentration analysis unit.

[0340] b H2O (SF6)=(C 质标 (SF6)-(k(SF6)×C 质原始 (SF6)+b(SF6)))×C 质控 (H2O) / C i (H2O)

[0341] = (100 - (1.03 × 97 - 0.25)) × 8 / 8

[0342] =0.34.

[0343] Furthermore, the flow rate quality control coefficient k(v) of the tracer gas SF6 is calculated: the release flow rate of the high-purity SF6 tracer controlled by the tracer gas unit is: Q x =11mL / min, released into the flue, mixed, and then the tracer gas passed downstream of the flue through the probe and heated pipeline to the concentration analysis unit. After stabilization, the average concentration of SF6 over 5 minutes was recorded as C. v2 =100ppb, the flow monitoring unit of the CEMS system takes the average flow rate over 5 minutes, denoted as v = 6m / s, and calculates the flow quality control coefficient k(v). The quality control coefficient is updated and saved to the system's industrial control computer, and the release of the tracer standard gas is stopped.

[0344]

[0345] Further, the carbon dioxide emissions in the flue gas emission stream are calculated. The CEMS system performs normal measurements, extracts flue gas, and uses the CO2 data from the concentration analysis unit to calculate the hourly average concentration C. i (CO2) = 8.5%, the flow monitoring unit monitors the flow velocity v data, the main control analysis unit calculates the hourly average v = 6.5 m / s, and the main control analysis unit calculates the hourly carbon dioxide emissions:

[0346]

[0347] Furthermore, zero-point and range quality control are performed every 7 days: the quality control unit turns on the N2 quality control standard gas, outputs 3L / min N2, transmits it to the probe of the acquisition unit, and then through the heated pipeline to the concentration analysis unit. The concentration analysis unit monitors the concentration data and records it as Z. n (CO2) = 0.1, Z n (SF6) = 0.5, CEMS system concentration range R: CO2: 0–25%, SF6: 0–200 ppb. Calculate zero drift:

[0348]

[0349] Quality control criteria: Zero-point drift should not exceed ±3% FS. If it does, zero-point calibration is required, and b(CO2) and b(SF6) should be updated.

[0350] The quality control unit sequentially turns on 25% CO2 quality control standard gas, outputting 3L / min of CO2 quality control standard gas, which is transmitted to the probe of the acquisition unit, and then through a heated pipeline to the concentration analysis unit. The concentration analysis unit monitors the concentration data and records it as S. n (CO2) = 25.2, CEMS system concentration range R: CO2: 0–25%, calculated range drift:

[0351]

[0352] Quality control criteria: Range drift should not exceed ±3% FS. If it does, range calibration and k(CO2) updates are required.

[0353] The quality control unit sequentially opens a 200ppb SF6 quality control standard gas supply, outputting 3L / min of SF6 quality control standard gas, which is transmitted to the probe of the acquisition unit, and then through a heated pipeline to the concentration analysis unit. The concentration analysis unit monitors the concentration data and records it as S. n (SF6) = 201.6, CEMS system concentration range R: SF6: 0~200ppb. Calculate range drift:

[0354]

[0355] Quality control indicator: Range drift should not exceed ±3% FS. If it does, range calibration and k(SF6) updates are required.

[0356] Furthermore, wet matrix quality control standards were performed every 30 days:

[0357] The average humidity of the flue gas emission stream over 5 minutes was recorded as 8%, and the average CO2 concentration over 5 minutes was recorded as 8.5%.

[0358] The quality control unit generated 8% humidity and C s(8.5%) wet-basis CO2 quality control standard gas was transferred at 3 L / min to the probe of the acquisition unit, and then through a heated pipeline to the concentration analysis unit. The concentration analysis unit monitored the concentration data and recorded it as C. i (CO2) = 8.3%, calculate the indication error:

[0359]

[0360] Quality control indicator: Indication error should not exceed ±5%. If it does, calibration is required, and the humidity effect deviation coefficient needs to be updated.

[0361] The quality control unit controls the mixing ratio to account for 8% humidity and C. s Moist SF6 standard gas containing (100ppb)SF6 is transmitted at a rate of 3L / min to the probe of the acquisition unit, and then through a heated pipeline to the concentration analysis unit. The concentration analysis unit monitors the concentration data and records it as C. i (SF6) = 98 ppb, calculate the indication error:

[0362]

[0363] Quality control indicator: Indication error should not exceed ±5%. If it does, calibration is required, and the humidity effect deviation coefficient needs to be updated.

[0364] Furthermore, flow quality control is performed every 30 days:

[0365] Obtain the 5-minute average flue gas velocity of the flue gas emission stream, denoted as 6 m / s; obtain the volumetric flow rate of SF6 released in the flue gas emission stream: Q. x =11 mL / min.

[0366] The quality control unit controls the release flow rate of high-purity tracer gas SF6, releasing it at 11 mL / min upstream of the flue. After dilution, the gas passes through the probe of the acquisition unit and a heated pipeline to the concentration analysis unit. The concentration analysis unit monitors the concentration data, and after stabilization, takes the average value over 5 minutes, denoted as C(SF6) = 99 ppb, and calculates the flow rate quality control coefficient k(v). The quality control coefficient is updated and saved to the system's industrial control computer, and the release of the tracer gas is stopped.

[0367]

[0368] The contents not described in detail in this specification are prior art known to those skilled in the art. Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art 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. A CEMS-based direct carbon emission monitoring system, including: The tracer gas unit is used to measure the volume concentration C. v1 and volumetric flow rate Q x Release tracer gas upstream of the flue gas emission stream; A collection unit is used to collect flue gas samples downstream of the flue gas emission stream; The concentration analysis unit is used to obtain the volume concentration C of the tracer standard gas in the flue gas sample. v2 and carbon dioxide volume concentration C i (CO2); A flow monitoring unit is used to obtain the volumetric flow rate Q(v) of the flue gas emission stream; The main control analysis unit receives the volumetric flow rate Q. x The volume concentration C v1 and the volume concentration C v2 The volumetric flow rate Q of the tracer standard gas in the flue gas sample was obtained: In the formula, Q:m 3 / h;C v1 :%;C v2 :%;Q x :L / min; Receive the volumetric flow rate Q(v) of the flue gas emission stream to obtain the flow quality control coefficient k(v): Calculate the carbon dioxide emission G in the flue gas emission stream: 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):%; It also includes a quality control unit, which is used to release a quality control standard gas and guide it to the concentration analysis unit via the acquisition unit to obtain the concentration information of the quality control standard gas. The main control analysis unit obtains a quality control coefficient based on the received concentration information of the quality control standard gas, and the quality control coefficient is used to calibrate the original concentration obtained by the concentration analysis unit. The quality control coefficients include the range quality control coefficient k, the zero-point quality control coefficient b, and the humidity quality control coefficient. The range quality control coefficient k, the zero-point quality control coefficient b, and the humidity quality control coefficient are used to determine the range quality control coefficient k, the zero-point quality control coefficient b, and the humidity quality control coefficient b. The original concentration obtained by the concentration analysis unit of the quality control system: In the formula, C i : Monitor the volume concentration of gases; C 原始 Volume concentration of uncontrolled gas obtained by the concentration analysis unit; C i (H2O): Humidity of the monitored gas obtained by the concentration analysis unit; C 质控 (H2O): Humidity released from the quality control standard gas.

2. The direct carbon emission monitoring system based on CEMS according to claim 1, wherein the tracer gas is selected from one of SF6, CO, Freon, and perfluoroisobutyronitrile.

3. The CEMS-based direct carbon emission monitoring system according to claim 1, wherein the quality control standard gas includes dry matrix control standard gas and wet matrix control standard gas; The dry basis control gas includes dry basis zero point control gas and dry basis range control gas.

4. The CEMS-based direct carbon emission monitoring system according to claim 3, wherein 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 by the acquisition unit to the concentration analysis unit to obtain the concentration information of carbon dioxide or tracer gas in the dry-basis 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 tracer gas.

5. In the CEMS-based direct carbon emission monitoring system according to claim 3, the dry-basis zero-point standard gas is selected from nitrogen.

6. The CEMS-based direct carbon emission monitoring system according to claim 3, wherein the dry-basis range standard gas is used to obtain the range quality control coefficient k: The quality control unit releases the dry-based range standard gas, which is guided by the acquisition unit to the concentration analysis unit to obtain the concentration information of the dry-based range standard gas. The main control analysis unit obtains the range quality control coefficient k based on the received concentration information of the dry-based range standard gas.

7. The CEMS-based direct carbon emission monitoring system according to claim 3, wherein the dry-basis range standard gas is carbon dioxide or tracer standard gas.

8. The CEMS-based direct carbon emission monitoring system according to claim 3, wherein the wet matrix control standard gas is used to obtain the humidity quality control coefficient. The quality control unit releases the wet matrix control gas, which is guided by the acquisition unit to the concentration analysis unit to obtain the concentration information of the wet matrix control gas. The main control analysis unit obtains the humidity quality control coefficient based on the received concentration information of the wet matrix control gas. In the formula, C 质标 : Volumetric concentration of the control gas released from the wet matrix; C 质原始 The volume concentration of the wet matrix control gas obtained from the concentration analysis unit; C 质控 (H2O): Humidity of the wet matrix control gas obtained from the concentration analysis unit; C 质标 (H2O): The release humidity of the control gas in the wet matrix.

9. The direct carbon emission monitoring system based on CEMS according to claim 3, wherein the wet matrix control standard gas is a wet-based carbon dioxide standard gas or a wet-based tracer standard gas.

10. The CEMS-based direct carbon emission monitoring system according to claim 3, wherein 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 dry matrix control standard gas to the acquisition unit, and the humidity generation module is used to receive the dry matrix control standard gas and generate the wet matrix control standard gas to release to the acquisition unit.

11. The CEMS-based direct carbon emission monitoring system according to claim 1, wherein the acquisition unit includes a sampling probe and a heat tracing pipeline, the sampling probe is located downstream of the flue gas emission stream, and the heat tracing pipeline is used to connect the sampling probe and the concentration analysis unit.

12. The CEMS-based direct carbon emission monitoring system according to claim 11, wherein the sampling probe is equipped with a device for filtering particulate matter.

13. In the CEMS-based direct carbon emission monitoring system according to claim 11, both the tracer gas and the quality control gas are transmitted via heated pipelines.

14. The direct carbon emission monitoring system based on CEMS according to claim 1, wherein the concentration analysis unit adopts a Fourier transform infrared (FTIR) gas analyzer.

15. A CEMS-based direct carbon emission monitoring method performed using the CEMS-based direct carbon emission monitoring system as described in any one of claims 1-14, comprising: The tracer gas was prepared at a volume concentration of C. v1 and volumetric flow rate Q x Release tracer gas upstream of the flue gas emission stream; Flue gas samples were collected downstream of the flue gas emission stream, and the volume concentration C of the tracer standard gas in the flue gas samples was obtained using a concentration analysis unit. v2 and the volume concentration of carbon dioxide C i (CO2); Through the volumetric flow rate Q x The volume concentration C v1 and the volume concentration C v2 The volumetric flow rate Q of the tracer standard gas in the flue gas sample was obtained: In the formula, Q:m 3 / h;C v1 :%;C v2 :%;Q x :L / min; The volumetric flow rate Q(v) of the flue gas emission stream is monitored and compared with the volumetric flow rate Q of the tracer gas to obtain the flow quality control coefficient k(v): Calculate the carbon dioxide emission G in the flue gas emission stream: 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):%; The volume concentration C of the carbon dioxide i (CO2) and the volume concentration C of the tracer gas v2 Concentration after quality control: A quality control standard gas is released into the concentration analysis unit to obtain its concentration information. A quality control coefficient is calculated by comparing this concentration with the initial concentration of the quality control standard gas. This quality control coefficient is used to calibrate the original concentration obtained by the concentration analysis unit, thereby obtaining the volume concentration C of the carbon dioxide. i (CO2) and the volume concentration C of the tracer gas v2 ; The quality control coefficients include the range quality control coefficient k, the zero-point quality control coefficient b, and the humidity quality control coefficient. The range quality control coefficient k, the zero-point quality control coefficient b, and the humidity quality control coefficient are used to determine the range quality control coefficient k, the zero-point quality control coefficient b, and the humidity quality control coefficient b. The original concentration obtained by the concentration analysis unit of the quality control system: In the formula, C i : Monitor the volume concentration of gases; C 原始 Volume concentration of uncontrolled gas obtained by the concentration analysis unit; C i (H2O): Humidity of the monitored gas obtained by the concentration analysis unit; C 质控 (H2O): Humidity released from the quality control standard gas.

16. The direct carbon emission monitoring method based on CEMS according to claim 15, wherein the tracer gas is selected from one of SF6, CO, Freon, and perfluoroisobutyronitrile.

17. The direct carbon emission monitoring method based on CEMS according to claim 15, wherein the quality control standard gas includes dry matrix control standard gas and wet matrix control standard gas; The dry basis control gas includes dry basis zero point control gas and dry basis range control gas.

18. The direct carbon emission monitoring method based on CEMS according to claim 17, wherein the dry-basis zero-point standard gas is used to obtain the zero-point quality control coefficient b: Release the dry-basis zero-point standard gas into the concentration analysis unit to obtain the concentration information of carbon dioxide or tracer standard gas in the dry-basis zero-point standard gas, and obtain the zero-point quality control coefficient b.

19. The direct carbon emission monitoring method based on CEMS according to claim 17, wherein the dry basis zero-point standard gas is selected from nitrogen.

20. The direct carbon emission monitoring method based on CEMS according to claim 17, wherein the dry-basis range standard gas is used to obtain the range quality control coefficient k: Release the dry-based standard gas to the concentration analysis unit, obtain the concentration information of the standard gas, and analyze the range quality control coefficient k.

21. The direct carbon emission monitoring method based on CEMS according to claim 17, wherein the dry-basis range standard gas is carbon dioxide or tracer standard gas.

22. The direct carbon emission monitoring method based on CEMS according to claim 17, wherein the wet matrix control standard gas is used to obtain the humidity quality control coefficient. The wet matrix control gas is released into the concentration analysis unit to obtain the concentration information of the wet matrix control gas and to obtain the humidity quality control coefficient. In the formula, C 质标 : Volumetric concentration of the control gas released from the wet matrix; C 质原始 The volume concentration of the wet matrix control gas obtained from the concentration analysis unit; C 质控 (H2O): Humidity of the wet matrix control gas obtained from the concentration analysis unit; C 质标 (H2O): The release humidity of the control gas in the wet matrix.

23. The direct carbon emission monitoring method based on CEMS according to claim 17, wherein the wet matrix control standard gas is a wet-based carbon dioxide standard gas or a wet-based tracer standard gas.

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