A pollution source monitoring system and method

Abstract

The present invention provides a pollution source monitoring system, which relates to the field of harmful gas monitoring technology. It includes a precise testing unit, which includes a monitoring chamber, a gas storage device, and a sampling channel; three lenses perpendicular to the same plane are installed in the monitoring chamber, and the three lenses have an angle with each other and form a triangular prism with an equilateral triangle cross section. A laser and a receiver are installed in the monitoring chamber. The laser is used to emit a laser that can be absorbed by harmful gases. The laser emitted by the laser is incident on a lens at an angle of 60°, and then enters the triangular prism. After the laser is reflected in an equilateral triangle in the triangular prism, it passes through the incident lens to the receiver; the sampling channel is connected to the flue gas pipeline, and the gas storage device stores standard gas that does not absorb laser. The pollution source monitoring system provided by the present invention can monitor the concentration of harmful gases in the pollution source.

Description

Technical Field

[0001] The present invention relates to the technical field of gas monitoring, and in particular to a pollution source monitoring system and method. Background Art

[0002] The flue gas emitted by pollution sources such as factories or power plants often carries some harmful gases, such as sulfur oxides, nitrogen oxides, etc. In order to protect the environment, these harmful gases need to be harmlessly treated before being discharged. In order to determine whether the flue gas discharged meets the standards, it is necessary to monitor the harmful gases emitted by the pollution source and after harmless treatment.

[0003] Therefore, in view of the above problems, there is an urgent need for a system and method that can monitor the concentration of harmful gases in flue gas discharged from pollution sources such as factories or power plants. Summary of the invention

[0004] The present invention provides a pollution source monitoring system and method, which can monitor the concentration of harmful gases in the flue gas discharged from pollution sources such as factories or power plants. The technical solution of the present invention is as follows:

[0005] The present invention provides a pollution source monitoring system, comprising a precision testing unit, wherein the precision testing unit comprises a monitoring chamber, a gas storage device, and a sampling channel;

[0006] The monitoring chamber is provided with three lenses perpendicular to the same plane, and the three lenses are angled with each other to form a triangular prism with an equilateral triangle cross section. The monitoring chamber is provided with a laser and a receiver, and the laser is used to emit laser light that can be absorbed by harmful gases. The laser light emitted by the laser is incident on one lens at an angle of 60°, and then enters the triangular prism. The laser light is reflected in the triangular prism in the form of an equilateral triangle, and then passes through the incident lens to the receiver;

[0007] The sampling channel is connected to the flue gas pipeline, the gas storage device stores standard gas that does not absorb laser, the sampling channel, the gas storage device and the monitoring chamber are connected through a three-way device, and each way is provided with a valve.

[0008] Optionally, the monitoring chamber includes an exhaust port, and a fan is installed at the exhaust port. The fan is used to cooperate with the valve of the three-way device to control the smoke or the standard gas to enter or be discharged from the monitoring chamber.

[0009] Optionally, the laser comprises a tunable laser, which is capable of adjusting the wavelength of the output laser to monitor a variety of harmful gases.

[0010] Optionally, the inner side of the triangular prism is coated with a reflective layer with a reflectivity lower than 100%, and the side of the lens for incident and outgoing laser light away from the inside of the triangular prism is coated with a transmissive layer.

[0011] Optionally, a continuous testing unit is further included, wherein the continuous testing unit includes a speed regulating channel, a monitoring channel, and a harmful gas concentration sensor;

[0012] One end of the speed regulating channel is connected to the flue gas duct, and the other end of the speed regulating channel is connected to the monitoring channel. The speed regulating channel is a telescopic tube, and a compression release device is fixedly connected to the outer wall of the speed regulating channel. The compression release device is used to squeeze or release the speed regulating channel to change its cross-sectional area, thereby controlling the gas flow rate in the monitoring channel so that the gas in the monitoring channel is laminar flow;

[0013] A sliding device that can move up and down is installed on the inner wall of the end of the monitoring channel away from the speed regulating channel, and the harmful gas concentration sensor is installed on the sliding device;

[0014] When monitoring the concentration of harmful gases, the compression release device is used to adjust the cross-sectional area of ​​the speed regulating channel to make the airflow in the monitoring channel laminar, and the sliding device is used to move the harmful gas concentration sensor up and down to collect multiple harmful gas concentration values, and the harmful gas concentration in the flue gas is calculated based on the multiple harmful gas concentration values.

[0015] Optionally, a flow velocity collection device is installed at the end of the monitoring channel away from the speed regulation channel. The flow velocity collection device is used to collect the gas flow velocity at the end of the monitoring channel and feed the gas flow velocity back to the compression release device. The compression release device adjusts the cross-sectional area of ​​the speed regulation channel to keep the gas flow velocity inside the monitoring channel unchanged.

[0016] Optionally, the monitoring channel is in the shape of a cylinder or a quadrangular prism.

[0017] The present invention also provides a pollution source monitoring method, which uses the above-mentioned pollution source monitoring system and comprises:

[0018] When testing the concentration of harmful gases, firstly, the standard gas in the gas storage device is introduced into the monitoring chamber, and the laser is turned on;

[0019] When the intensity of the laser received by the receiver reaches a preset light intensity, the laser is turned off and timing is started. When the intensity of the laser received by the receiver is weakened to a preset weakening value, timing is stopped to obtain a control time.

[0020] The smoke in the smoke duct is passed into the monitoring chamber through the sampling channel, and the laser is turned on;

[0021] When the intensity of the laser received by the receiver reaches a preset light intensity, the laser is turned off and timing is started. When the intensity of the laser received by the receiver is weakened to a preset weakening value, timing is stopped to obtain the test time.

[0022] The concentration of harmful gases is calculated according to the control time and the test time.

[0023] Optionally, the monitoring method of the pollution source monitoring system further includes:

[0024] Adjusting the compression release device to squeeze or release the speed regulating channel to change its cross-sectional area, so that the airflow in the monitoring channel is laminar flow;

[0025] Controlling the sliding device to move downward from the top, and recording the first position when the harmful gas concentration sensor detects that the concentration of the harmful gas exceeds a preset concentration;

[0026] Continue to control the sliding device to move downward, and record the second position when the harmful gas concentration sensor detects that the concentration of the harmful gas is lower than the preset concentration;

[0027] Moving the sliding device between the first position and the second position to collect a plurality of harmful gas concentration values;

[0028] The concentration of harmful gases in the flue gas is calculated according to the multiple harmful gas concentration values.

[0029] Optionally, calculating the concentration of harmful gases in the flue gas according to the multiple harmful gas concentration values ​​includes:

[0030] Calculating an average value of a plurality of the harmful gas concentration values;

[0031] Calculating the cross-sectional area of ​​the monitoring channel between the horizontal plane where the first position is located and the horizontal plane where the second position is located to obtain the cross-sectional area of ​​the harmful gas layer;

[0032] The concentration of the harmful gas in the flue gas is calculated based on the average value, the cross-sectional area of ​​the monitoring channel and the cross-sectional area of ​​the harmful gas layer.

[0033] Compared with the prior art, the present invention has at least the following beneficial effects:

[0034] In the present invention, the characteristic that harmful gases can absorb lasers of fixed wavelengths is utilized, a laser is set to emit lasers that can be absorbed by harmful gases, and a receiver is set to receive the lasers reflected by the triangular prism, so as to realize the test of the concentration of harmful gases based on this. By setting three lenses, the three lenses form a triangular prism. After the laser enters the monitoring chamber at an angle of 60°, the laser is continuously reflected in the triangular prism surrounded by the three lenses. The reflected light path is an equilateral triangle. The triangular light path has a longer moving distance than a single straight light path. Under the same level of space size, the triangular light path moves a longer distance, the total amount of harmful gases in the light path is more, the effect of absorbing the laser intensity is more obvious, and the test accuracy is higher. When testing the concentration of harmful gases, first pass the standard gas in the gas storage device into the monitoring chamber, turn on the laser, and when the laser intensity received by the receiver reaches the preset light intensity, turn off the laser and start timing. When the laser intensity received by the receiver weakens to the preset weakening value, stop timing and obtain the control time; after the flue gas in the flue gas duct passes into the monitoring chamber through the sampling channel, the test time is obtained in the same way; the concentration of harmful gases is calculated based on the control time and the test time. In summary, the pollution source monitoring system and method provided by the present invention can monitor the concentration of harmful gases in the flue gas discharged from pollution sources such as factories or power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 It is a structural schematic diagram of a pollution source monitoring system provided by an embodiment of the present invention.

[0037] In the figure:

[0038] 100-smoke duct;

[0039] 11- Monitoring chamber;

[0040] 12- Gas storage device;

[0041] 13- Sampling channel;

[0042] 14- triangular prism;

[0043] 15-Laser;

[0044] 16 - Receiver;

[0045] 21-speed regulation channel;

[0046] 22- Monitoring channel;

[0047] 23- Compression release device;

[0048] 24-sliding device;

[0049] 25- Harmful gas concentration sensor;

[0050] 26-Flow rate acquisition device. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0052] like Figure 1 As shown, an embodiment of the present invention provides a pollution source monitoring system, including a precision testing unit, the precision testing unit including a monitoring chamber 11, a gas storage device 12, and a sampling channel 13;

[0053] Three lenses perpendicular to the same plane are installed in the monitoring chamber 11. The three lenses are at an angle to each other and form a triangular prism 14 with an equilateral triangle cross section. A laser 15 and a receiver 16 are installed in the monitoring chamber 11. The laser 15 is used to emit laser light that can be absorbed by harmful gases. The laser light emitted by the laser 15 is incident on a lens at an angle of 60° and then enters the triangular prism 14. The laser light is reflected in the triangular prism 14 in the form of an equilateral triangle and then passes through the incident lens to the receiver 16.

[0054] The sampling channel 13 is connected to the flue gas pipeline 100. The gas storage device 12 stores standard gas that does not absorb laser. The sampling channel 13, the gas storage device 12 and the monitoring chamber 11 are connected through a three-way device, and each of the three-way devices is provided with a valve.

[0055] In the present invention, the concentration of harmful gases can be tested by utilizing the characteristic that harmful gases can absorb lasers of fixed wavelengths. In order to increase the accuracy of monitoring, three lenses are set, and the three lenses form a triangular prism 14. After the laser enters the monitoring chamber 11 at an angle of 60°, the laser is continuously reflected in the triangular prism 14 surrounded by the three lenses, and the reflected light path is an equilateral triangle. The triangular light path has a longer moving distance than a single straight light path. Under the same level of space size, the triangular light path moves a longer distance, the total amount of harmful gases in the light path is more, the effect of absorbing laser intensity is more obvious, and the test accuracy is higher.

[0056] The monitoring method of the above-mentioned pollution source monitoring system is:

[0057] When testing the concentration of harmful gases, firstly, the standard gas in the gas storage device 12 is introduced into the monitoring chamber 11, and the laser 15 is turned on;

[0058] When the intensity of the laser received by the receiver 16 reaches the preset light intensity, the laser 15 is turned off and timing is started. When the intensity of the laser received by the receiver 16 is weakened to the preset weakening value, timing is stopped to obtain the control time.

[0059] The smoke in the smoke duct 100 is passed into the monitoring chamber 11 through the sampling channel 13, and the laser 15 is turned on;

[0060] When the intensity of the laser received by the receiver 16 reaches the preset light intensity, the laser 15 is turned off and timing is started. When the intensity of the laser received by the receiver 16 is weakened to the preset weakening value, timing is stopped to obtain the test time.

[0061] The concentration of harmful gases is calculated based on the control time and test time.

[0062] In this embodiment, before testing the concentration of harmful gases in the flue gas, it is necessary to calibrate with standard gas. Specifically, first pass the standard gas into the monitoring chamber 11, turn on the laser 15, and while the laser is constantly reflected in the triangular prism 14, part of it will be transmitted out of the triangular prism 14 and incident on the receiver 16. As the laser of the laser 15 is continuously output, the intensity of the laser received by the receiver 16 continues to increase. After increasing to the preset light intensity, the laser 15 is turned off and the timing is started. Due to the loss of the laser source, the intensity of the laser constantly reflected in the triangular prism 14 gradually weakens, and the intensity of the laser received by the receiver 16 is also weakened. When the intensity of the laser received by the receiver 16 weakens to the preset weakening value, the timing is stopped to obtain the control time, which is the time when the laser weakens when there is no absorption; the standard gas is discharged from the monitoring chamber 11, and the flue gas is passed into the monitoring chamber 11, and the test time is obtained by the same method. Due to the presence of harmful gases in the flue gas, the harmful gases will absorb the laser, and the test time is shorter than the control time. The greater the difference between the two, the higher the concentration of the harmful gas. Specifically, the concentration of the harmful gas is calculated by the following formula:

[0063] n=(1 / c)×(1 / t2-1 / t1)×1 / s

[0064] Wherein, n is the concentration of harmful gas, c is the speed of light, t1 is the control time, and t2 is the test time; s is the absorption cross section of harmful gas, which can be measured by a spectrometer or other methods, and can also be obtained by other methods, which will not be elaborated in detail in this embodiment.

[0065] In this embodiment, the harmful gas may be sulfur oxides, nitrogen oxides or carbon monoxide.

[0066] In some embodiments of the present invention, the monitoring chamber 11 includes an exhaust port, and a fan is installed at the exhaust port. The fan is used to cooperate with the valve of the three-way device to control the smoke or standard gas to enter or discharge from the monitoring chamber 11.

[0067] In some embodiments of the present invention, the laser 15 includes a tunable laser, which can adjust the wavelength of the output laser to monitor a variety of harmful gases.

[0068] In some embodiments of the present invention, the inner side of the triangular prism 14 is coated with a reflective layer with a reflectivity lower than 100%, and the side of the lens for incident and outgoing laser light away from the inside of the triangular prism 14 is coated with a transmissive layer.

[0069] It should be noted that the higher the reflective layer, the slower the laser intensity decreases and the better the data obtained. However, the reflectivity of the reflective layer cannot be 100%. If it is 100% reflective, the laser will not be able to transmit through the triangular prism 14, and the receiver 16 will not be able to receive the laser intensity.

[0070] In some embodiments of the present invention, a pollution source monitoring system further includes a continuous testing unit, which includes a speed regulating channel 21, a monitoring channel 22, and a harmful gas concentration sensor 25;

[0071] One end of the speed regulating channel 21 is connected to the flue gas duct 100, and the other end of the speed regulating channel 21 is connected to the monitoring channel 22. The speed regulating channel 21 is a retractable tube, and a compression release device 23 is fixedly connected to the outer wall of the speed regulating channel 21. The compression release device 23 is used to squeeze or release the speed regulating channel 21 to change its cross-sectional area, thereby controlling the gas flow rate in the monitoring channel 22 so that the gas in the monitoring channel 22 is laminar flow;

[0072] A sliding device 24 that can move up and down is installed on the inner wall of the end of the monitoring channel 22 away from the speed regulating channel 21, and a harmful gas concentration sensor 25 is installed on the sliding device 24;

[0073] When monitoring the concentration of harmful gases, the compression release device 23 is used to adjust the cross-sectional area of ​​the speed regulating channel 21 so that the airflow in the monitoring channel 22 is laminar, and the sliding device 24 is used to move the harmful gas concentration sensor 25 up and down to collect multiple harmful gas concentration values. The harmful gas concentration in the flue gas is calculated based on the multiple harmful gas concentration values.

[0074] In the present invention, the cross-sectional area of ​​the speed regulating channel 21 with telescopic performance can be adjusted by using the compression release device 23. Specifically, the compression release device 23 can be a telescopic rod, and the telescopic end of the telescopic rod is fixed to the outer wall of the speed regulating channel 21. Preferably, the compression release device 23 is provided on both the upper and lower surfaces of the speed regulating channel 21. When the compression release device 23 squeezes the speed regulating channel 21, its cross-sectional area becomes smaller, and less smoke passes through. After less smoke enters the monitoring channel 22, the flow rate is slower; on the contrary, when the compression release device 23 releases the speed regulating channel 21, its cross-sectional area becomes larger, and more smoke passes through. After more smoke enters the monitoring channel 22, the flow rate is faster. By controlling the flow rate of the smoke in the monitoring channel 22, the smoke in the monitoring channel 22 is made laminar. In the laminar smoke, harmful gases are often enriched in the upper layer of the laminar flow. The concentration of harmful gases in the harmful gas layer is high and easy to be detected. The harmful gas concentration sensor 25 with low cost can be used to measure it. The harmful gas concentration sensor 25 is moved in a direction perpendicular to the laminar flow by using the sliding device 24. When the harmful gas concentration sensor 25 passes through the harmful gas layer, a plurality of harmful gas concentration values ​​are obtained. The harmful gas concentration in the flue gas can be obtained according to the plurality of harmful gas concentration values.

[0075] In this embodiment, the flow rate of the laminar flow of the smoke in the monitoring channel 22 can be determined by experiments, and the flow rate of the laminar flow of the airflow in the monitoring channel 22 can also be determined by the Reynolds number. Specifically, in the pipe flow, the flow with a Reynolds number less than 2300 is laminar flow, and the Reynolds number Re=ρvd / μ, where ρ is the density of the smoke, which can be calculated by the density formula ρ=pM / RT derived from the ideal gas equation (the molar mass M only considers the main components in the smoke), v is the flow rate, d is the equivalent diameter of the pipe, and μ is the viscosity coefficient of the fluid.

[0076] In this embodiment, the speed regulating channel 21 may be a bellows, which has excellent strength and also has a telescopic function.

[0077] In the present invention, the precise test unit can obtain precise harmful gas concentration data, but cannot obtain continuous harmful gas concentration data; the continuous test unit can obtain continuous harmful gas concentration data, but the accuracy of the concentration data obtained is lower than that of the precise test unit, and if the concentration of the harmful gas is too low, it may not be detected. The combination of the precise test unit and the continuous test unit can obtain more multi-dimensional and three-dimensional pollution source harmful gas concentration monitoring data.

[0078] Based on the above content, the monitoring method of the pollution source monitoring system further includes:

[0079] Adjust the compression release device 23 to squeeze or release the speed regulating channel 21 to change its cross-sectional area, so that the airflow in the monitoring channel 22 is laminar flow; control the sliding device 24 to move downward from the top, and record the first position when the harmful gas concentration sensor 25 detects that the concentration of the harmful gas exceeds the preset concentration; continue to control the sliding device 24 to move downward, and record the second position when the harmful gas concentration sensor 25 detects that the concentration of the harmful gas is lower than the preset concentration; move the sliding device 24 between the first position and the second position to collect multiple harmful gas concentration values; calculate the harmful gas concentration in the flue gas according to the multiple harmful gas concentration values.

[0080] In this embodiment, the harmful gas layer is often located in the upper layer of the laminar flow, so moving the harmful gas sensor 5 from top to bottom facilitates the rapid capture of the specific position of the harmful gas layer. When the harmful gas concentration is monitored to increase rapidly or suddenly increase to above the preset concentration, the first position is recorded, and the harmful gas concentration sensor 25 is continued to move downward. When the harmful gas concentration is monitored to decrease rapidly or suddenly decrease to below the preset concentration, the second position is recorded, and multiple harmful gas concentration values ​​are collected between the first position and the second position, and the harmful gas concentration in the flue gas is obtained based on the multiple harmful gas concentration values.

[0081] It is understandable that the first position and the second position may be calibrated once at an interval using the same method, or the first position and the second position may be re-determined each time the movement is made from top to bottom.

[0082] It should be noted that different preset concentrations can be set according to the sensitivity of the harmful gas concentration sensor 25. For example, when the sensitivity of the harmful gas concentration sensor 25 is low, the preset concentration can be 0; when the sensitivity of the harmful gas concentration sensor 25 is low, it can be a non-zero value.

[0083] It should also be noted that the above system can be used to set up a plurality of different types of concentration sensors for monitoring different types of harmful gases, so as to test the concentrations of different harmful gases respectively.

[0084] In some embodiments of the present invention, the concentration of harmful gases in the flue gas is calculated based on multiple harmful gas concentration values, including: calculating the average value of the multiple harmful gas concentration values; calculating the cross-sectional area of ​​the monitoring channel 22 between the horizontal plane where the first position is located and the horizontal plane where the second position is located, and obtaining the cross-sectional area of ​​the harmful gas layer; calculating the concentration of harmful gases in the flue gas based on the average value, the cross-sectional area of ​​the monitoring channel 22 and the cross-sectional area of ​​the harmful gas layer.

[0085] In this embodiment, the average value of the multiple harmful gas concentration values ​​is the harmful gas concentration value of the harmful gas layer, which is higher than the harmful gas concentration value of the entire flue gas and needs to be processed. The cross-sectional area of ​​the harmful gas layer can be obtained by monitoring the cross-sectional area of ​​the channel 22, the first position, and the second position. The concentration of the harmful gas in the flue gas can be calculated by calculating the proportion of the cross-sectional area of ​​the harmful gas layer in the cross-sectional area of ​​the monitoring channel 22 and then multiplying it by the average value.

[0086] In some embodiments of the present invention, the concentration of harmful gases in the flue gas is calculated by the following formula:

[0087] n=a×s1 / s2

[0088] Wherein, n is the concentration of harmful gas, a is the average value, s1 is the cross-sectional area of ​​the harmful gas layer, and s2 is the cross-sectional area of ​​the monitoring channel 22 .

[0089] In some embodiments of the present invention, a flow rate collection device 26 is installed at the end of the monitoring channel 22 away from the speed regulation channel 21. The flow rate collection device 26 is used to collect the gas flow rate at the end of the monitoring channel 22 and feed the gas flow rate back to the compression release device 23. The compression release device 23 adjusts the cross-sectional area of ​​the speed regulation channel 21 to keep the gas flow rate inside the monitoring channel 22 unchanged.

[0090] In this embodiment, a PLC controller may be used to implement data feedback and device control.

[0091] In some embodiments of the present invention, the flow velocity collection device 26 includes a differential pressure air flow velocity measuring device, a thermal air flow velocity measuring device or an ultrasonic air flow velocity measuring device.

[0092] In some embodiments of the present invention, the harmful gas concentration sensor 25 includes an electrochemical sensor, an optical sensor, an infrared sensor or a semiconductor sensor.

[0093] In some embodiments of the present invention, the monitoring channel 22 is in the shape of a cylinder or a quadrangular prism. The cylindrical monitoring channel 22 is more conducive to the stability of the laminar flow.

[0094] The embodiment of the present invention further provides a pollution source monitoring method, which adopts the above-mentioned pollution source monitoring system and includes:

[0095] When testing the concentration of harmful gases, firstly, the standard gas in the gas storage device is introduced into the monitoring chamber, and the laser is turned on;

[0096] When the intensity of the laser received by the receiver reaches a preset light intensity, the laser is turned off and timing is started. When the intensity of the laser received by the receiver is weakened to a preset weakening value, timing is stopped to obtain a control time.

[0097] The smoke in the smoke duct is passed into the monitoring chamber through the sampling channel, and the laser is turned on;

[0098] When the intensity of the laser received by the receiver reaches a preset light intensity, the laser is turned off and timing is started. When the intensity of the laser received by the receiver is weakened to a preset weakening value, timing is stopped to obtain the test time.

[0099] The concentration of harmful gases is calculated according to the control time and the test time.

[0100] Optionally, the monitoring method of the pollution source monitoring system further includes:

[0101] Adjusting the compression release device to squeeze or release the speed regulating channel to change its cross-sectional area, so that the airflow in the monitoring channel is laminar flow;

[0102] Controlling the sliding device to move downward from the top, and recording the first position when the harmful gas concentration sensor detects that the concentration of the harmful gas exceeds a preset concentration;

[0103] Continue to control the sliding device to move downward, and record the second position when the harmful gas concentration sensor detects that the concentration of the harmful gas is lower than the preset concentration;

[0104] Moving the sliding device between the first position and the second position to collect a plurality of harmful gas concentration values;

[0105] The concentration of harmful gases in the flue gas is calculated according to the multiple harmful gas concentration values.

[0106] Optionally, calculating the concentration of harmful gases in the flue gas according to the multiple harmful gas concentration values ​​includes:

[0107] Calculating an average value of a plurality of the harmful gas concentration values;

[0108] Calculating the cross-sectional area of ​​the monitoring channel between the horizontal plane where the first position is located and the horizontal plane where the second position is located to obtain the cross-sectional area of ​​the harmful gas layer;

[0109] The concentration of the harmful gas in the flue gas is calculated based on the average value, the cross-sectional area of ​​the monitoring channel and the cross-sectional area of ​​the harmful gas layer.

[0110] The specific implementation of each step in the monitoring method has been described in detail in the above embodiments and will not be repeated here.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pollution source monitoring system, characterized in that: It comprises a precision testing unit, wherein the precision testing unit comprises a monitoring chamber (11), a gas storage device (12), and a sampling channel (13); The monitoring chamber (11) is provided with three lenses perpendicular to the same plane, the three lenses are angled with each other and form a triangular prism (14) whose cross section is an equilateral triangle. The monitoring chamber (11) is provided with a laser (15) and a receiver (16). The laser (15) is used to emit laser light that can be absorbed by harmful gases. The laser light emitted by the laser (15) is incident on one lens at an angle of 60° and then enters the triangular prism (14). The laser light is reflected in the triangular prism (14) in the form of an equilateral triangle and then passes through the incident lens to the receiver (16). The sampling channel (13) is connected to the flue gas pipeline (100), the gas storage device (12) stores a standard gas that does not absorb laser light, the sampling channel (13), the gas storage device (12) and the monitoring chamber (11) are connected via a three-way device, and each of the three-way devices is provided with a valve; It also includes a continuous testing unit, which includes a speed regulating channel (21), a monitoring channel (22), and a harmful gas concentration sensor (25); One end of the speed regulating channel (21) is connected to the flue gas duct (100), and the other end of the speed regulating channel (21) is connected to the monitoring channel (22); the speed regulating channel (21) is a telescopic tube; an outer wall of the speed regulating channel (21) is fixedly connected to a compression release device (23); the compression release device (23) is used to compress or release the speed regulating channel (21) to change its cross-sectional area, thereby controlling the gas flow rate in the monitoring channel (22) so that the gas in the monitoring channel (22) is laminar flow; A sliding device (24) movable in an up-and-down direction is installed on the inner wall of the end of the monitoring channel (22) away from the speed regulating channel (21), and the harmful gas concentration sensor (25) is installed on the sliding device (24); When performing harmful gas concentration monitoring, the compression release device (23) is used to adjust the cross-sectional area of ​​the speed regulating channel (21) so that the airflow in the monitoring channel (22) is laminar, and the sliding device (24) is used to move the harmful gas concentration sensor (25) up and down to collect multiple harmful gas concentration values, and the harmful gas concentration in the flue gas is calculated based on the multiple harmful gas concentration values; A flow rate collection device (26) is installed at the end of the monitoring channel (22) away from the speed regulating channel (21). The flow rate collection device (26) is used to collect the gas flow rate at the end of the monitoring channel (22) and feed the gas flow rate back to the compression release device (23). The compression release device (23) adjusts the cross-sectional area of ​​the speed regulating channel (21) so that the gas flow rate inside the monitoring channel (22) remains unchanged.

2. A pollution source monitoring system according to claim 1, characterized in that: The monitoring chamber (11) comprises an exhaust port, the exhaust port being equipped with a fan, the fan being used to cooperate with the valve of the three-way device to control the smoke or the standard gas to enter or be discharged from the monitoring chamber (11).

3. A pollution source monitoring system according to claim 1 or 2, characterized in that: The laser (15) comprises a tunable laser, which can adjust the wavelength of the output laser to monitor a variety of harmful gases.

4. A pollution source monitoring system according to claim 1 or 2, characterized in that: The inner side of the triangular prism (14) is coated with a reflective layer with a reflectivity lower than 100%, and the side of the lens for incident and emitted laser light away from the inside of the triangular prism (14) is coated with a transmission layer.

5. A pollution source monitoring system according to claim 1, characterized in that: The monitoring channel (22) is in the shape of a cylinder or a quadrangular prism.

6. A pollution source monitoring method, characterized in that: A pollution source monitoring system according to any one of claims 1 to 5 above, comprising: When testing the concentration of harmful gases, firstly, the standard gas in the gas storage device (12) is introduced into the monitoring chamber (11), and the laser (15) is turned on; When the intensity of the laser light received by the receiver (16) reaches a preset light intensity, the laser (15) is turned off and timing is started; when the intensity of the laser light received by the receiver (16) is weakened to a preset weakening value, timing is stopped to obtain a control time; The smoke in the smoke duct (100) is passed into the monitoring chamber (11) through the sampling channel (13), and the laser (15) is turned on; When the intensity of the laser received by the receiver (16) reaches a preset light intensity, the laser (15) is turned off and timing is started; when the intensity of the laser received by the receiver (16) is weakened to a preset weakening value, timing is stopped to obtain the test time; The concentration of harmful gases is calculated according to the control time and the test time.

7. A pollution source monitoring method according to claim 6, characterized in that: Also includes: The compression release device (23) is adjusted to compress or release the speed regulating channel (21) to change its cross-sectional area, so that the airflow in the monitoring channel (22) is laminar flow; Controlling the sliding device (24) to move downward from the top, and recording a first position when the harmful gas concentration sensor (25) detects that the concentration of the harmful gas exceeds a preset concentration; Continue to control the sliding device (24) to move downward, and record the second position when the harmful gas concentration sensor (25) detects that the concentration of the harmful gas is lower than a preset concentration; Moving the sliding device (24) between the first position and the second position to collect a plurality of harmful gas concentration values; The concentration of harmful gases in the flue gas is calculated according to the multiple harmful gas concentration values.

8. A pollution source monitoring method according to claim 7, characterized in that: The calculating the concentration of harmful gases in the flue gas according to the multiple concentration values ​​of harmful gases comprises: Calculating an average value of a plurality of the harmful gas concentration values; Calculating the cross-sectional area of ​​the monitoring channel (22) between the horizontal plane where the first position is located and the horizontal plane where the second position is located, to obtain the cross-sectional area of ​​the harmful gas layer; The concentration of the harmful gas in the flue gas is calculated based on the average value, the cross-sectional area of ​​the monitoring channel (22) and the cross-sectional area of ​​the harmful gas layer.

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