Atmospheric VOCs sampling control system and atmospheric VOCs sampling system

Abstract

The utility model discloses an atmospheric VOCs sampling control system and an atmospheric VOCs sampling system, and relates to the technical field of atmospheric environment monitoring, the atmospheric VOCs sampling control system comprises a pressure sensor, a wind direction sensor and a data acquisition module, the pressure sensor is used for monitoring the air pressure in a sampling tank in real time; the wind direction sensor is fixedly installed in a first area, the vertical distance between the first area and the sampling head is 5-25 m, the horizontal distance between the first area and the sampling head is 0-5 m, and the wind direction sensor is used for monitoring wind direction information in the first area; the data acquisition module is in communication connection with the pressure sensor and the wind direction sensor and is used for receiving the air pressure information and the wind direction information. According to the utility model, the purposes of detecting the pressure of the gas tank and detecting the wind direction can be achieved, and the sampling system can be controlled to work through pressure information and wind direction information so as to improve the effectiveness of VOCs monitoring sampling data.

Description

Technical Field

[0001] This utility model relates to the field of atmospheric environmental monitoring technology, and in particular to an atmospheric VOCs sampling and control system and an atmospheric VOCs sampling system. Background Technology

[0002] Atmospheric VOCs sampling systems typically include a sampling head, a sampling tank, and sampling equipment. The sampling head is connected to the sampling equipment via a pipeline, and the sampling equipment is connected to the sampling tank via a pipeline. The sampling equipment acts as a suction power source, drawing outside air from the sampling head into the sampling tank. Current technologies typically perform atmospheric sampling by controlling the opening and closing of the sampling equipment. However, current atmospheric VOCs monitoring and sampling systems suffer from two technical bottlenecks due to the lack of pressure and wind direction sensors: firstly, real-time monitoring of pressure fluctuations during sampling is impossible, making it difficult to dynamically assess the airtightness of the high-vacuum tank; secondly, the lack of dynamic tracking of wind direction changes in the sampling environment makes it impossible to effectively avoid instantaneous interference from downwind pollution sources, thereby reducing the effectiveness of the monitoring data. Utility Model Content

[0003] The purpose of this invention is to provide an atmospheric VOCs sampling and control system and an atmospheric VOCs sampling system to solve the problems existing in the prior art and improve the effectiveness of VOCs monitoring and sampling data. To achieve the above objective, this invention provides the following solution:

[0004] This utility model provides an atmospheric VOCs sampling and control system, including a pressure sensor, a wind direction sensor, and a data acquisition module. The pressure sensor is used to monitor the air pressure inside the sampling tank in real time. The wind direction sensor is fixedly installed in a first area at a vertical distance of 5-25 meters and a horizontal distance of 0-5 meters from the sampling head, and is used to monitor the wind direction information in the first area. The data acquisition module is communicatively connected to the pressure sensor and the wind direction sensor respectively, and is used to receive air pressure information and wind direction information.

[0005] In some embodiments, the pressure sensor is a diffused silicon pressure sensor.

[0006] In some embodiments, the pressure sensor has an external thread on its outer wall, and the pressure sensor can be threadedly connected to a threaded mounting port reserved on the sampling tank.

[0007] In some embodiments, a sealing gasket is also included, which is disposed within the installation gap between the external thread and the threaded mounting opening of the sampling vessel.

[0008] In some embodiments, the sealing gasket is a fluororubber gasket.

[0009] In some embodiments, the wind direction sensor is a three-cup wind direction sensor.

[0010] In some embodiments, the three-cup wind direction sensor is fixed to the top of a bracket, which supports the wind direction sensor within the first area.

[0011] In some embodiments, an SO2 sensor and a CO2 sensor are also included. The SO2 sensor and the CO2 sensor are disposed at the sampling head of the sampling system. The SO2 sensor is used to monitor the SO2 gas concentration information at the sampling head, and the CO2 sensor is used to monitor the CO2 gas concentration information at the sampling head. The SO2 sensor and the CO2 sensor are communicatively connected to the data acquisition module, and the data acquisition module is also used to receive SO2 gas concentration information and CO2 gas concentration information.

[0012] In some implementations, the data acquisition module includes:

[0013] A signal receiver is configured to receive pressure information transmitted from the pressure sensor, wind direction information transmitted from the wind direction sensor, SO2 gas concentration information transmitted from the SO2 sensor, and CO2 gas concentration information transmitted from the CO2 sensor; and

[0014] The signal conditioning circuit is communicatively connected to the signal receiver and is used to amplify and filter the received pressure information, wind direction information, and gas concentration information.

[0015] This utility model also provides an atmospheric VOCs sampling system comprising: a sampling head, a sampling tank, a sampling device, and an atmospheric VOCs sampling control system as described in any one of the above; the sampling head is connected to the sampling device via a pipeline, and the sampling device is connected to the sampling tank via a pipeline.

[0016] The present invention achieves the following technical advantages over the prior art:

[0017] The atmospheric VOCs sampling and control system provided by this utility model, by configuring pressure sensors and wind direction sensors, realizes real-time monitoring of the pressure inside the sampling tank and monitoring of the wind direction. This allows staff or microprocessors to determine the airtightness of the sampling tank based on pressure information and to determine whether there is pollution source interference in the sampling area based on wind direction information. This technical solution achieves real-time detection of tank pressure, which helps to eliminate errors caused by airtightness defects. On the other hand, it identifies downwind pollution source interference in real time through wind direction sensors. The sampling system only starts sampling when the airtightness is qualified and there is no pollution source interference in the sampling area; otherwise, sampling stops. This eliminates abnormal data caused by pollution source interference due to poor airtightness and downwind direction, thereby significantly improving the effectiveness of VOCs monitoring data. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of this utility model;

[0020] Figure 2 This is a flowchart for sampling control based on pressure information;

[0021] Figure 3 This is a flowchart illustrating sampling control based on wind direction information, SO2 gas concentration information, and CO2 gas concentration information.

[0022] In the diagram: 1-Sampling tank; 2-Pressure sensor; 3-Data acquisition module; 4-Sampling equipment; 5-Sampling head; 6-Wind direction sensor; 7-SO2 sensor; 8-CO2 sensor. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] The purpose of this invention is to provide an atmospheric VOCs sampling and control system and an atmospheric VOCs sampling system to solve the problems existing in the prior art. On the one hand, it eliminates errors caused by air tightness defects in atmospheric VOCs monitoring and sampling; on the other hand, it uses a wind direction sensor to identify interference from downwind pollution sources in real time, realizing multiple intelligent discrimination and dynamic optimization of the sampling environment, thereby significantly improving the effectiveness of VOCs monitoring data.

[0025] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Example 1

[0027] like Figure 1-3 As shown, this utility model embodiment provides an atmospheric VOCs sampling and control system, including a pressure sensor 2, a wind direction sensor 6, and a data acquisition module 3. The pressure sensor 2 is used to monitor the air pressure inside the sampling tank 1 in real time; the wind direction sensor 6 is fixedly installed in a first area with a vertical distance of 5-25 meters and a horizontal distance of 0-5 meters from the sampling head 5, and the wind direction sensor is used to monitor the wind direction information in the first area; the data acquisition module 3 is communicatively connected to the pressure sensor 2 and the wind direction sensor 6 respectively, and is used to receive air pressure information and wind direction information.

[0028] The atmospheric VOCs sampling system provided in this embodiment requires equipment installation and debugging before sampling: First, install the sampling tank 1 and pressure sensor 2, and place the high-vacuum sampling tank 1 on a stable base to ensure that the tank is not tilted; then fix the wind direction sensor 6 in an area 10-20 meters directly above the sampling head 5, with a horizontal distance of 0-5 meters, and adjust according to the site environment to avoid obstruction by buildings or trees; finally, connect the pressure sensor 2 to the signal input port of the data acquisition module 3; and connect the wind direction sensor 6 to the signal input port of the data acquisition module 3.

[0029] The atmospheric VOCs sampling system provided in this embodiment uses a pressure sensor 2 and a wind direction sensor 6 to monitor the pressure and wind direction inside the sampling tank 1 in real time. This allows staff or a microprocessor to determine the airtightness of the sampling tank 1 based on the pressure information and to determine the pollution source interference in the sampling area based on the wind direction information. The system can then be controlled to start and stop based on the judgment results.

[0030] The specific usage method is as follows: Before starting sampling, the airtightness of sampling canister 1 is calibrated using pressure sensor 2. The principle is to first draw air into sampling canister 1 at a small flow rate using sampling device 4, and then use pressure sensor 2 to detect the pressure inside sampling canister 1 in real time. The airtightness is determined by whether there are pressure fluctuations inside sampling canister 1. Additionally, the wind direction is used to determine whether sampling head 5 is downwind of the pollution source. If the airtightness of sampling canister 1 is acceptable and sampling head 5 is not downwind of the pollution source, sampling device 4 can begin sampling. If the airtightness of sampling canister 1 is unacceptable and / or sampling head 5 is downwind of the pollution source, an anomaly is recorded.

[0031] During the sampling process, pressure and wind direction information are monitored in real time. If the airtightness of sampling tank 1 is qualified and sampling head 5 is not downwind of the pollution source, the sampling process continues until the sampling is completed. If sampling tank 1 leaks air and / or sampling head 5 is downwind of the pollution source, the sampling is stopped and the abnormality is recorded.

[0032] The pressure sensor 2 and the wind direction sensor 6 are calibrated. The air tightness is then determined based on the pressure information. If it is qualified, the wind direction is used to determine whether it is not downwind. If it is not downwind, sampling begins. If it is not qualified, sampling is stopped. During the sampling process, the pressure information is monitored in real time. If the pressure information fluctuates beyond the normal range, sampling is stopped.

[0033] This embodiment achieves real-time detection of tank pressure, eliminating errors caused by airtightness defects; on the other hand, it uses wind direction sensor 6 to identify interference from downwind pollution sources in real time, enabling multiple discrimination and dynamic optimization of the sampling environment, thereby significantly improving the effectiveness of VOCs monitoring data.

[0034] Furthermore, pressure sensor 2 is connected to the signal input port of data acquisition module 3 via RS485 bus; wind direction sensor 6 is connected to the signal input port of data acquisition module 3 via RS485 bus.

[0035] In some examples, all cables used for communication connections are protected by conduits to prevent cross-interference and are clearly labeled.

[0036] Furthermore, considering that when the pollution source is far away or the amount of pollutant gas emitted by the pollution source is small, even if the sampling head 5 is downwind of the pollution source, it may still not affect the effectiveness of the sampling. If sampling is stopped directly, the sampling efficiency will be reduced. Therefore, in order to solve this problem, this embodiment also includes an SO2 sensor 7 and a CO2 sensor 8. The SO2 sensor 7 and CO2 sensor 8 are used to communicate with the data acquisition module 3 at the sampling head 5 of the sampling system. The data acquisition module 3 is also used to receive SO2 gas concentration information and CO2 gas concentration information.

[0037] In this embodiment, SO2 sensor 7 and CO2 sensor 8 are integrated into a multi-functional sensor. This embodiment uses SO2 and CO2 gas concentration information in the sampling area to characterize the impact of pollution source emissions on sampling effectiveness. If the SO2 and CO2 gas concentration information is less than the set threshold, the impact on effectiveness is small. Therefore, when sampling head 5 is downwind of the pollution source and the airtightness is qualified, sampling can still be started or continued. If sampling head 5 is downwind of the pollution source and the SO2 and CO2 gas concentration information is greater than the set threshold, an anomaly is recorded.

[0038] In some examples, SO2 sensor 7 and CO2 sensor 8 are connected to the signal input port of data acquisition module 3 via RS485 bus.

[0039] Furthermore, pressure sensor 2 is a diffused silicon pressure sensor.

[0040] This embodiment uses a diffused silicon pressure sensor, which has a measurement accuracy of ±0.001MPa, and can meet the requirements for accurate measurement of the air pressure of sampling tank 1. In other embodiments, any technical solution that can detect airtightness, such as ceramic pressure sensor or fiber optic pressure sensor, is used and is within the scope of protection of this application.

[0041] Furthermore, the pressure sensor 2 has external threads on its outer wall, which connect to the threaded mounting port of the sampling container 1. In some examples, to improve the sealing performance of the sampling container 1, a sealing gasket is provided in the mounting gap between the external threaded connection of the pressure sensor 2 and the threaded mounting port of the sampling container 1. The sealing gasket is preferably fluororubber, but other materials such as nitrile rubber and polytetrafluoroethylene can also be used.

[0042] When installing pressure sensor 2, first embed a fluororubber sealing gasket at the threaded mounting port. Then screw pressure sensor 2 into the pre-reserved threaded mounting port at the top of sampling tank 1 and tighten it with a preset torque of 10-15 N·m to avoid excessive tightening that could damage the threads. The sealing performance is then tested using a helium mass spectrometer leak detector. Both contact scanning (probe close to the tank weld and valve) and non-contact scanning (probe 5-30 cm away from the tank) are used. The leak type is determined based on the signal characteristics (continuous high frequency or pulse type), the leak location is marked, and then repaired.

[0043] This embodiment uses a threaded connection, which is simple and convenient. Of course, in some examples, other methods besides threaded connections can also be used, such as snap-fit ​​or plug-in connections.

[0044] In this embodiment, a sealing element is installed at the connection between the external thread of the pressure sensor and the threaded mounting port of the sampling tank 1 to precisely fill the microscopic gaps of the mating surfaces, forming a multi-level sealing barrier that effectively resists the effects of high pressure and corrosion, ensuring long-term sealing stability.

[0045] Furthermore, the wind direction sensor 6 is a three-cup wind direction sensor.

[0046] This embodiment uses a three-cup sensor with a measurement error of ≤±3°, which can accurately identify wind direction information. In other embodiments, any technical solution that can detect wind direction, such as a wind vane type wind direction sensor or a piezoelectric wind direction sensor, is within the protection scope of this application.

[0047] Furthermore, a three-cup wind direction sensor is used to fix it to the top of the bracket, which supports the wind direction sensor in the first area. In some examples, a high-strength aluminum alloy bracket can be used for fixing and installation.

[0048] Furthermore, the data acquisition module 3 includes: a signal receiver, used to receive pressure information transmitted from pressure sensor 2, wind direction information transmitted from wind direction sensor 6, SO2 gas concentration information transmitted from SO2 sensor 7, and CO2 gas concentration information transmitted from CO2 sensor 8; a signal conditioning circuit, which is communicatively connected to the signal receiver, used to amplify and filter the received pressure, wind direction, and gas concentration information; and a microprocessor, which is an ARM microprocessor, communicatively connected to the signal conditioning circuit, used to perform logical judgments on the data information processed by the signal conditioning circuit. The above embodiment is to facilitate the use of a microprocessor to implement the operation of the automatic control sampling system; specifically as follows:

[0049] Before sampling begins, each sensor is calibrated: First, pressure sensor 2 is calibrated using a standard pressure source (such as a 0-1MPa calibrator) to ensure the measurement error is ≤ ±0.001MPa; then, wind direction sensor 6 is calibrated by artificially simulating different wind directions (such as 0°, 90°, and 180°) and adjusting the sensor until the measurement error is ≤ ±3°; finally, SO2 sensor 7 and CO2 sensor 8 are calibrated by introducing standard gases of known concentrations, with preset low, medium, and high concentrations (such as 20%, 50%, and 80% concentration values), recording the sensor output data, and adjusting the error to ≤ ±2%.

[0050] After the above operation steps are correct, the microprocessor is used to determine whether the airtightness of sampling tank 1 is qualified based on the pressure information;

[0051] If so, then determine whether any of the following conditions are met:

[0052] 1. The wind direction is not downwind of the pollution source;

[0053] Second, the wind direction is downwind of the pollution source, but the SO2 and CO2 gas concentrations meet the preset conditions.

[0054] If so, then control the sampling system to start sampling;

[0055] If not, trigger an alarm and log the anomaly;

[0056] If not, trigger an alarm and log the anomaly;

[0057] During the sampling process, the microprocessor is used to determine whether the airtightness of sampling tank 1 is qualified based on the pressure information;

[0058] If so, then determine whether any of the following conditions are met:

[0059] 1. The wind direction is not downwind of the pollution source;

[0060] Second, the wind direction is downwind of the pollution source, but the SO2 and CO2 gas concentrations meet the preset conditions.

[0061] If so, then control the sampling system to continue sampling;

[0062] If not, stop sampling, trigger an alarm, and log the anomaly;

[0063] If not, stop sampling, trigger an alarm, and log the anomaly.

[0064] This embodiment provides a method for automatically processing pressure, wind direction, and gas concentration information using a microprocessor and automatically controlling the operation of the sampling system. This embodiment achieves automatic control of atmospheric VOCs detection and sampling, saving labor costs.

[0065] Example 2

[0066] This utility model provides an atmospheric VOCs sampling system, including the atmospheric VOCs sampling and control system in Embodiment 1.

[0067] This embodiment possesses all the advantages of the above embodiments, and will not be repeated here.

[0068] Explanation, such as Figure 1 In the embodiment shown, there are multiple sampling tanks 1. Therefore, the atmospheric VOCs sampling control system therein also needs to have multiple pressure sensors 2, with one pressure sensor 2 installed on each sampling tank 1.

[0069] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. An atmospheric VOCs sampling and control system, characterized in that, include: A pressure sensor is used to monitor the air pressure inside the sampling tank in real time; A wind direction sensor is fixedly installed in a first area at a vertical distance of 5-25 meters and a horizontal distance of 0-5 meters from the sampling head. The wind direction sensor is used to monitor wind direction information within the first area. as well as The data acquisition module is communicatively connected to the pressure sensor and the wind direction sensor, respectively, and is used to receive and process air pressure information and wind direction information.

2. The atmospheric VOCs sampling and control system according to claim 1, characterized in that, The pressure sensor is a diffused silicon pressure sensor.

3. The atmospheric VOCs sampling and control system according to claim 1, characterized in that, The pressure sensor has an external thread on its outer wall, and the pressure sensor can be threadedly connected to the threaded mounting port reserved on the sampling tank.

4. The atmospheric VOCs sampling and control system according to claim 3, characterized in that, It also includes a sealing gasket, which is used to be disposed in the installation gap between the external thread and the threaded mounting opening of the sampling tank.

5. The atmospheric VOCs sampling and control system according to claim 4, characterized in that, The sealing gasket is a fluororubber gasket.

6. The atmospheric VOCs sampling and control system according to claim 1, characterized in that, The wind direction sensor is a three-cup wind direction sensor.

7. The atmospheric VOCs sampling and control system according to claim 6, characterized in that, The three-cup wind direction sensor is fixed to the top of the bracket, which supports the wind direction sensor within the first area.

8. The atmospheric VOCs sampling and control system according to claim 1, characterized in that, It also includes an SO2 sensor and a CO2 sensor, which are installed at the sampling head of the sampling system. The SO2 sensor is used to monitor the SO2 gas concentration information at the sampling head, and the CO2 sensor is used to monitor the CO2 gas concentration information at the sampling head. The SO2 sensor and the CO2 sensor are communicatively connected to the data acquisition module, which is also used to receive SO2 gas concentration information and CO2 gas concentration information.

9. The atmospheric VOCs sampling and control system according to claim 8, characterized in that, The data acquisition module includes: A signal receiver is configured to receive pressure information transmitted from the pressure sensor, wind direction information transmitted from the wind direction sensor, SO2 gas concentration information transmitted from the SO2 sensor, and CO2 gas concentration information transmitted from the CO2 sensor; and The signal conditioning circuit is communicatively connected to the signal receiver and is used to amplify and filter the received pressure information, wind direction information, and gas concentration information.

10. An atmospheric VOCs sampling system, characterized in that, include: The sampling head, sampling tank, sampling equipment, and atmospheric VOCs sampling control system according to any one of claims 1 to 9; the sampling head is connected to the sampling equipment through a pipeline, and the sampling equipment is connected to the sampling tank through a pipeline.

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