An online flue gas carbon emission monitoring system and method

Abstract

The present invention relates to an online flue gas carbon emission monitoring system and method, comprising: a partitioning device fixedly arranged in the flue, the partitioning device dividing the space in the flue into a plurality of detection areas with equal areas; a flow velocity measuring device including a plurality of three-dimensional pitot tubes, each of the three-dimensional pitot tubes being arranged at intervals; the three-dimensional pitot tube includes a tube body and a plurality of probes arranged at intervals on the tube body, each of the probes extending into each detection area, and the measuring end face of the probe being perpendicular to the flue gas flow direction in the flue; an automatic switching device, provided in a plurality and respectively arranged on each of the tube bodies; a measurement and data acquisition device connected to each of the automatic switching devices; a terminal connected to the measurement and data acquisition device and communicating with each of the automatic switching devices. The technical solution of the present invention can measure the dynamic pressure of the flue gas more accurately, and then calculate a more accurate carbon emission amount.

Description

Technical Field

[0001] The present invention relates to the technical field of online carbon emission monitoring, and particularly to an online flue gas carbon emission monitoring system and method. Background Art

[0002] Currently, algorithms are mainly used to measure carbon emissions. However, due to the advantages of timeliness and less human interference in the online monitoring system, the online carbon emission monitoring technology is bound to develop into the main means of carbon emission monitoring. However, the existing flue gas volume monitoring technology has low measurement accuracy for flue gas flow, resulting in large deviations in the calculation of carbon emissions. Summary of the Invention

[0003] The purpose of the present invention is to provide an online flue gas carbon emission monitoring system, which has the characteristics of accurately detecting flue gas flow and has good applicability.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions:

[0005] An online flue gas carbon emission monitoring system includes: a partitioning device fixedly arranged in the flue, the partitioning device dividing the space in the flue into multiple detection areas with equal areas; a velocity measuring device including a plurality of three-dimensional pitot tubes, the three-dimensional pitot tubes being arranged at intervals; each three-dimensional pitot tube including a tube body and a plurality of probes arranged at intervals on the tube body, each probe extending into each detection area, and the measuring end face of the probe being perpendicular to the flue gas flow direction in the flue; an automatic switching device provided in multiple numbers and respectively arranged on each tube body; a measurement and data acquisition device connected to each automatic switching device; and a terminal connected to the measurement and data acquisition device and communicating with each automatic switching device.

[0006] Preferably, the probe is located at the center of the detection area, and the measuring end face of the probe is spherical;

[0007] The measuring end face of the probe is provided with a plurality of pressure measuring holes, and the axial direction of each pressure measuring hole is parallel to the flue gas flow direction in the flue.

[0008] Preferably, the pressure measuring holes are five, namely a first pressure measuring hole, a second pressure measuring hole, a third pressure measuring hole, a fourth pressure measuring hole, and a fifth pressure measuring hole. The first pressure measuring hole is located at the center of the measuring end face of the probe, and the second pressure measuring hole, the third pressure measuring hole, the fourth pressure measuring hole, and the fifth pressure measuring hole are symmetrically arranged in a circular pattern with the first pressure measuring hole as the center.

[0009] Preferably, it further includes a plurality of transmission pipelines, one end of the transmission pipeline is connected to the measurement and data acquisition device, and the other end is connected to the automatic switching device; the data, dynamic pressure, and static pressure detected by the three-dimensional Pitot tube enter the measurement and data acquisition device through the transmission pipeline relying on the three-dimensional Pitot tube.

[0010] Preferably, the measurement and data acquisition device includes a thermocouple and a component measurement pipeline. The thermocouple measures the temperature of the flue gas, and the component measurement pipeline measures the humidity, oxygen concentration, and greenhouse gas concentration of the flue gas.

[0011] The present invention also provides an online flue gas carbon emission monitoring method. The online flue gas carbon emission monitoring method includes the above-mentioned online flue gas carbon emission monitoring system, and the online flue gas carbon emission monitoring method includes the following steps:

[0012] According to the set inspection time of the terminal, the measurement time of the three-dimensional Pitot tube is controlled by the automatic switching device. The three-dimensional Pitot tube measures the dynamic pressure and static pressure of the flue gas in the flue, and uploads the dynamic pressure and static pressure to the measurement and data acquisition device;

[0013] The measurement and data acquisition device measures the temperature, humidity, oxygen concentration, and greenhouse gas concentration of the flue gas, and uploads the temperature, humidity, oxygen concentration, greenhouse gas concentration, dynamic pressure, and static pressure to the terminal. The terminal first calculates the axial velocity of the flue gas and finally calculates the carbon emission.

[0014] Preferably, the calculation steps of the axial velocity of the flue gas include the following:

[0015] In the first step, calibrate the three-dimensional Pitot tube in a standard wind tunnel. After calibration, two calibration curves are obtained, namely the F1 vs. pitch angle relationship curve and the F2 vs. pitch angle relationship curve. Among them, F1 is the ratio of the pitch angle differential pressure to the dynamic pressure, and F2 is the three-dimensional Pitot tube speed calibration coefficient;

[0016] In the second step, measure the yaw angle θyi. When measuring, the angle displayed by the yaw angle measuring device has positive and negative values. Looking from the tail of the three-dimensional Pitot tube, when the pressure measuring hole rotates clockwise relative to the flue axis, the yaw angle is recorded as positive; when the pressure measuring hole rotates counterclockwise, the yaw angle is recorded as negative;

[0017] In the third step, measure the atmospheric pressure Ba, the wet flue gas molecular weight Ms of the flue gas, and the flue gas temperature ts;

[0018] In the fourth step, calculate the pitch angle θpi. The dynamic pressures measured by the pressure measuring holes of the three-dimensional Pitot tube are P1, P2, P3, P4, and P5 respectively. According to the pressure differences of P1 - P2 and P4 - P5, the ratio F1 of the pitch angle differential pressure to the dynamic pressure at each velocity measuring point is obtained. According to the F1 vs. pitch angle calibration curve, the pitch angle θpi of the measuring point i at F1 is obtained;

[0019] Step 5, the axial gas velocity V at the inner measuring point i of the flue si is:

[0020]

[0021] In the formula: V Si —— the axial gas velocity at measuring point i, unit: meter per second (m / s);

[0022] K c —— conversion factor (constant),

[0023] t s —— flue gas temperature, unit: degree Celsius (°C);

[0024] P s —— static pressure of the flue, unit: Pascal (Pa);

[0025] B a —— atmospheric pressure, unit: Pascal (Pa);

[0026] M s —— molecular weight of wet flue gas, unit: kilogram per kilomole (kg / kmol);

[0027] θ yi —— yaw angle of the flue gas flow, unit: degree (°);

[0028] θ pi —— pitch angle of the flue gas flow, unit: degree (°).

[0029] Preferably, the calculation method of carbon emissions is:

[0030] m = V si × M × C 温室气体 × T

[0031] In the formula, m is the carbon emissions, unit: kilogram (kg / s);

[0032] V si is the axial gas velocity at the inner measuring point i of the flue. Unit: meter per second (m / s);

[0033] M is the area of the detection area, unit: square meter (m 2 );

[0034] C 温室气体 is the concentration of greenhouse gases in the flue gas, unit: kilogram per cubic meter (kg / m 3 ).

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] In the above technical solution, an on-line flue gas carbon emission monitoring system is provided. By arranging a partitioning device in the flue, the flue is partitioned into multiple smaller detection areas with equal areas, and the center of each detection area is a detection point; a plurality of probes are arranged at intervals on the pipe body, and each probe extends into each detection area one by one and is located at the detection point, and the measuring end face of the probe is perpendicular to the flow direction of the flue gas in the flue, so that the probe can measure the dynamic pressure of the flue gas more accurately. The dynamic pressure and the flue gas entering the three-dimensional pitot tube can enter the measurement and data acquisition device, and the measurement and data acquisition device measures the temperature, humidity, oxygen concentration, and greenhouse gas concentration of the flue gas. The terminal can calculate the carbon emission based on this data. The on-line flue gas carbon emission monitoring system can measure the dynamic pressure of the flue gas more accurately, and then calculate a more accurate carbon emission. Moreover, this system can be remotely controlled, reducing human intervention, reducing the input of operation and maintenance personnel, and realizing full-automatic and interference-free on-line monitoring. Brief Description of the Drawings

[0037] Figure 1 It is a schematic diagram of the on-line flue gas carbon emission monitoring system provided by the embodiment of the present invention.

[0038] Figure 2 It is a schematic diagram of the three-dimensional pitot tube provided by the embodiment of the present invention.

[0039] 1. Flue; 2. Partitioning device; 3. Three-dimensional pitot tube; 31. Pipe body; 32. Probe; 321. First pressure measurement hole; 322. Second pressure measurement hole; 323. Third pressure measurement hole; 324. Fourth pressure measurement hole; 325. Fifth pressure measurement hole; 4. Measurement and data acquisition device; 5. Terminal; 6. Transmission pipeline; 7. Automatic switching device. Detailed Embodiments

[0040] The present invention will be described in more detail below. It should be noted that the description of the present invention with reference to the accompanying drawings is only illustrative and not restrictive. Different embodiments can be combined with each other to form other embodiments not shown in the following description.

[0041] Please refer to Figure 1-2 , an on-line flue gas carbon emission monitoring system is provided in the embodiment of the present invention, including: a partitioning device 2, a speed measurement device, a measurement and data acquisition device 4, a terminal 5, a transmission pipeline 6, and an automatic switching device 7.

[0042] In a preferred embodiment, the partitioning device 2 is fixedly arranged in the flue 1, and the partitioning device 2 divides the flue 1 into a plurality of detection areas with the same area. Specifically, according to "GB / T 16157 - 1996 - Determination of Particulate Matter in Exhaust Gas from Stationary Pollution Sources and Sampling Methods for Gaseous Pollutants", measurement points are arranged in a matrix / equal - area layout method for the flue 1. At the same time, CFD software can be used to calculate the flow field of the flue 1, so as to obtain data such as the installation position and width of the partitioning device 2. By setting the partitioning device 2, the relatively large - area flue 1 is divided into a plurality of relatively small - area detection areas. The relatively small - area detection areas can reduce the irregular flow of the flue gas, so that the flue gas only moves along the axis of the detection area. According to the above method, it is effectively ensured that the flue gas vertically flows through the test end face of the three - dimensional pitot tube, improving the accuracy of dynamic pressure measurement and minimizing the influence of unstable air flow on the measurement. It can be imagined that the installation position and width of the partitioning device 2 can vary according to different projects.

[0043] Specifically, the partitioning device 2 can be a rectifying grid.

[0044] Preferably, the velocity - measuring device includes a plurality of three - dimensional pitot tubes 3. The three - dimensional pitot tube 3 includes a tube body 31 and a probe 32. The probes 32 are provided in a plurality and are spaced along the axial direction of the tube body 31. The probe 32 can extend into the corresponding detection area and be located at the measurement point. More preferably, the measurement point can be located at the central position of the detection area.

[0045] It can be imagined that a probe 32 is provided at the measurement point of each detection area, and the probe 32 can detect the dynamic pressure and static pressure of the flue gas at the corresponding measurement point.

[0046] In addition, the setting method of each three - dimensional pitot tube 3 is not limited, as long as each probe 32 can correspondingly extend into each detection area.

[0047] Preferably, the probe 32 extends into the detection area, and the measurement end face of the probe 32 is perpendicular to the axis of the detection area. Since the flue gas moves along the axis of the detection area, the flue gas can vertically flow through the measurement end face of the probe 32.

[0048] Specifically, the measurement end face of the probe 32 can be a spherical surface.

[0049] Preferably, a plurality of pressure - measuring holes are provided on the measurement end face of the probe 32, and the axial direction of each pressure - measuring hole is parallel to the flow direction of the flue gas in the detection area, so that the pressure - measuring holes can most accurately measure the dynamic pressure of the flue gas.

[0050] Preferably, there are five pressure measurement holes, namely the first pressure measurement hole 321, the second pressure measurement hole 322, the third pressure measurement hole 323, the fourth pressure measurement hole 324, and the fifth pressure measurement hole 325. The first pressure measurement hole 321 is located at the center of the measurement end face of the probe 32. The second pressure measurement hole 322, the third pressure measurement hole 323, the fourth pressure measurement hole 324, and the fifth pressure measurement hole 325 are symmetrically arranged in a circular pattern around the first pressure measurement hole 321. More specifically, the third pressure measurement hole 323 and the second pressure measurement hole 322 are symmetrically arranged on the left and right sides of the first pressure measurement hole 321, and the fifth pressure measurement hole 325 and the fourth pressure measurement hole 324 are symmetrically arranged on the upper and lower sides of the first pressure measurement hole 321. The distances between the second pressure measurement hole 322, the third pressure measurement hole 323, the fourth pressure measurement hole 324, the fifth pressure measurement hole 325 and the first pressure measurement hole 321 are all the same.

[0051] Preferably, one end of the pipe body 31 is closed, and the other end is connected to the automatic switching device 7. Each pipe body 31 corresponds to an automatic switching device 7. Each automatic switching device 7 is connected to the terminal 5 and is controlled by the terminal 5. The user can set the inspection time in the terminal 5, and the terminal 5 automatically controls and switches the measurement time of the automatic switching device 7 according to the inspection time, so as to meet the measurement cycle requirements of different total flue gas flow end faces and avoid the average measurement error of the existing matrix flowmeter.

[0052] During actual measurement, the terminal 5 controls only one three-dimensional Pitot tube 3 to measure through the automatic switching device 7, and the remaining three-dimensional Pitot tubes 3 are in the purging state. Therefore, the present application can also be provided with a purging device, and the purging device cooperates with each three-dimensional Pitot tube 3 correspondingly to purge the probe 32 to prevent the probe 32 from being blocked by particulate matter in the flue gas. The purging device is a prior art and will not be elaborated here.

[0053] Specifically, the automatic switching device 7 can be an electromagnetic valve, and sequential operation is achieved through PLC program control.

[0054] Preferably, each automatic switching device 7 is connected to the measurement and data acquisition device 4 through a transmission pipeline 6. Therefore, the dynamic pressure and static pressure data detected by the three-dimensional Pitot tube 3 can be transmitted to the measurement and data acquisition device 4 through the transmission pipeline 6. At the same time, the flue gas flowing into the three-dimensional Pitot tube 3 can also be transmitted into the measurement and data acquisition device 4 through the transmission pipeline.

[0055] The measurement and data acquisition device 4 includes a variety of measurement devices, specifically including a thermocouple and a component measurement pipeline. The thermocouple measures the temperature of the flue gas, and the component measurement pipeline measures the molecular weight of the wet flue gas. The molecular weight of the wet flue gas includes parameters such as humidity, greenhouse gas concentration, and O2 concentration.

[0056] The measurement and data acquisition device 4 can upload data such as the dynamic pressure, static pressure, and molecular weight of wet flue gas detected by the three-dimensional Pitot tube 3 to the terminal 5. Based on this data, the terminal 5 can calculate the axial velocity of the flue gas in the flue 1. The terminal 5 then calculates the carbon emissions based on the axial velocity of the flue gas, the molecular weight of the wet flue gas, and the detection area.

[0057] The present invention also provides an online flue gas carbon emission monitoring method, including the following steps:

[0058] According to the set inspection time of the terminal, control the measurement time of the three-dimensional Pitot tube through the automatic switching device. The three-dimensional Pitot tube measures the dynamic pressure and static pressure of the flue gas in the flue and uploads the dynamic pressure and static pressure to the measurement and data acquisition device;

[0059] The measurement and data acquisition device measures the temperature, humidity, oxygen concentration, and greenhouse gas concentration of the flue gas and uploads the temperature, humidity, oxygen concentration, greenhouse gas concentration, dynamic pressure, and static pressure to the terminal. The terminal first calculates the axial velocity of the flue gas and finally calculates the carbon emissions.

[0060] Among them, the calculation steps of the axial velocity of the flue gas include the following:

[0061] The first step is to calibrate the three-dimensional Pitot tube in a standard wind tunnel. After calibration, two calibration curves are obtained, namely the F1 vs. pitch angle relationship curve and the F2 vs. pitch angle relationship curve. Among them, F1 is the ratio of the pitch angle differential pressure to the dynamic pressure, and F2 is the velocity calibration coefficient of the three-dimensional Pitot tube;

[0062] The second step is to measure the yaw angle θyi. When measuring, the angle displayed by the yaw angle measuring device has positive and negative values. Looking from the tail of the three-dimensional Pitot tube, when the pressure measuring hole rotates clockwise relative to the flue axis, the yaw angle is recorded as positive; when the pressure measuring hole rotates counterclockwise, the yaw angle is recorded as negative;

[0063] The third step is to measure the atmospheric pressure Ba, the molecular weight Ms of the wet flue gas, and the flue gas temperature ts;

[0064] The fourth step is to calculate the pitch angle θpi. The dynamic pressures measured by the pressure measuring holes of the three-dimensional Pitot tube are P1, P2, P3, P4, and P5 respectively. According to the pressure differences of P1 - P2 and P4 - P5, the ratio F1 of the pitch angle differential pressure to the dynamic pressure at each velocity measuring point is obtained. According to the F1 vs. pitch angle calibration curve, the pitch angle θpi of the measuring point i at F1 is obtained;

[0065] The fifth step, the axial velocity V of the flue gas at the measuring point i in the flue si is:

[0066]

[0067] In the formula: V Si—— Axial velocity of flue gas at measuring point i, unit: meters per second (m / s);

[0068] K c —— Conversion factor (constant),

[0069] t s —— Flue gas temperature, unit: degree Celsius (°C);

[0070] P s —— Static pressure of the flue duct, unit: Pascal (Pa);

[0071] B a —— Atmospheric pressure, unit: Pascal (Pa);

[0072] M s —— Molecular weight of wet flue gas, unit: kilograms per kilomole (kg / kmol);

[0073] θ yi —— Yaw angle of flue gas flow, unit: degree (°);

[0074] θ pi —— Pitch angle of flue gas flow, unit: degree (°).

[0075] Among them, the calculation method of carbon emissions is:

[0076] m = V si × M × C 温室气体 × T

[0077] In the formula, m is the carbon emission, unit: kilograms per second (kg / s);

[0078] V si is the axial flow velocity of flue gas at measuring point i inside the flue duct. Unit: meters per second (m / s);

[0079] M is the area of the detection area, unit: square meters (m 2 );

[0080] C 温室气体 is the concentration of greenhouse gases in the flue gas, unit: kilograms per cubic meter (kg / m 3 ).

[0081] In summary, the online flue gas carbon emission monitoring method provided by the present invention measures the dynamic pressure and static pressure of the flue gas through the three-dimensional pitot tube 3, and measures the temperature, humidity, oxygen concentration, and greenhouse gas concentration of the flue gas through the measurement and data acquisition device 4. The terminal can measure the carbon emissions per unit time based on the data. In addition, since a partition device 2 is provided in the flue 1, the flue 1 is divided into a plurality of smaller detection areas, and the probes 32 of the three-dimensional pitot tube 3 are provided in each detection area one by one, and the measuring end face of the probe 32 is perpendicular to the flue gas flow direction, the three-dimensional pitot tube 3 can more accurately measure the dynamic pressure of the flue gas, and then calculate a more accurate carbon emission.

[0082] In addition, terminal 5 can summarize and report flue gas carbon emission data, and can perform default processing on default data that appears during the data collection process in accordance with relevant standard requirements. If abnormal data appears within a unit time period, data with a time period three times the length of the previous period can be used to fill the gap. At the same time, the device can set the automatic inspection time of the automatic switching device 7.

[0083] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. An online flue gas carbon emission monitoring system, characterized in that, Including: A separating device, fixedly arranged in the flue, which divides the space in the flue into a plurality of detection areas with equal areas; A velocity measuring device, including a plurality of three-dimensional Pitot tubes, with each of the three-dimensional Pitot tubes arranged at intervals; the three-dimensional Pitot tube includes a tube body and a plurality of probes arranged at intervals on the tube body, with each probe extending into each detection area, and the measuring end face of the probe being perpendicular to the flue gas flow direction in the flue; An automatic switching device, provided in a plurality and respectively arranged on each of the tube bodies; A measuring and data acquisition device, connected to each of the automatic switching devices; A terminal, connected to the measuring and data acquisition device and wirelessly connected to each of the automatic switching devices; A purging device, corresponding to each of the three-dimensional Pitot tubes in a one-to-one manner, and capable of purging each of the probes; Wherein, during measurement, according to the set inspection time of the terminal, the measurement time of the three-dimensional Pitot tube is controlled by the automatic switching device, and the terminal controls only one of the three-dimensional Pitot tubes to perform measurement through the automatic switching device, and the remaining three-dimensional Pitot tubes are in a purging state through the purging device.

2. The online flue gas carbon emission monitoring system according to claim 1, characterized in that, The probe is located at the center of the detection area, and the measuring end face of the probe is spherical; The measuring end face of the probe is provided with a plurality of pressure measuring holes, and the axial direction of each pressure measuring hole is parallel to the flue gas flow direction in the flue.

3. The on-line flue gas carbon emission monitoring system according to claim 2, wherein The pressure measuring holes are set to be five, namely a first pressure measuring hole, a second pressure measuring hole, a third pressure measuring hole, a fourth pressure measuring hole, and a fifth pressure measuring hole. The first pressure measuring hole is located at the center of the measuring end face of the probe, and the second pressure measuring hole, the third pressure measuring hole, the fourth pressure measuring hole, and the fifth pressure measuring hole are symmetrically arranged in a surrounding manner with the first pressure measuring hole as the center.

4. The on-line flue gas carbon emission monitoring system according to claim 1, wherein It further includes a plurality of transmission pipelines, one end of the transmission pipeline is connected to the measuring and data acquisition device, and the other end is connected to the automatic switching device; the data, dynamic pressure, and static pressure measured by the three-dimensional Pitot tube enter the measuring and data acquisition device through the transmission pipeline relying on the three-dimensional Pitot tube.

5. The online flue gas carbon emission monitoring system according to claim 1, wherein The measuring and data acquisition device includes a thermocouple and a component measuring pipeline. The thermocouple measures the temperature of the flue gas, and the component measuring pipeline measures the humidity, oxygen concentration, and greenhouse gas concentration of the flue gas.

6. An online flue gas carbon emission monitoring method, characterized in that, Including the online flue gas carbon emission monitoring system according to any one of claims 1-5, the online flue gas carbon emission monitoring method includes the following steps: According to the set inspection time of the terminal, the measurement time of the three-dimensional Pitot tube is controlled by the automatic switching device. The three-dimensional Pitot tube measures the dynamic pressure and static pressure of the flue gas in the flue and uploads the dynamic pressure and static pressure to the measuring and data acquisition device; The measuring and data acquisition device measures the temperature, humidity, oxygen concentration, and greenhouse gas concentration of the flue gas, and uploads the temperature, humidity, oxygen concentration, greenhouse gas concentration, dynamic pressure, and static pressure to the terminal. The terminal first calculates the axial flow velocity of the flue gas and finally calculates the carbon emission.

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