Modular sampling equipment and method for greenhouse gas of sewage treatment plant

Abstract

The invention relates to modular sampling equipment and method for greenhouse gas of a sewage treatment plant. The equipment comprises a body, a gas flow tube, a gas flowmeter, a switching valve, a sampling assembly and an air pressure, temperature and liquid level detection module. The equipment is in signal connection with each detection module through the processing module, judges the type of a sampling point according to the gas flow, and correspondingly executes open or closed sampling. During open type sampling, the electromagnetic valve is opened, the gas collection cavity is communicated with the outside, and gas is introduced for sampling; during closed sampling, the electromagnetic valve is closed, the gas collection cavity is closed from the outside, and gas is introduced. The sampling method is applied to the modularized sampling equipment. The modularized sampling equipment can be compatible with three different sampling point types, meets all scene requirements of greenhouse gas sampling of a current sewage plant, is more convenient to carry and use, and can reduce the equipment cost in the sampling process.

Description

Technical Field

[0001] The present application relates to the technical field of sewage treatment, and in particular to a modular sampling device and method for greenhouse gases in sewage treatment plants. Background Art

[0002] During the operation of the sewage treatment plant, it is necessary to sample the sewage to obtain the greenhouse gas emission flux of the sewage. Sampling scenarios are generally divided into unorganized emission sampling, fixed source emission sampling, and a combination of some unorganized + some fixed source emissions, and each sewage treatment plant basically involves sampling of aerated areas and non-aerated areas. For the above different scenarios, different types of sampling equipment are usually used for sampling in the prior art. For example, open flux boxes or large-capacity air bags are used for aerated areas, closed flux boxes are used for non-aerated areas, and atmospheric samplers are used for fixed source emissions.

[0003] In actual operation, the frequency of greenhouse gas emission measurement for a single sewage treatment plant is once a year or once every two years. Each sampling involves many sampling points, and a single sampling point usually takes about an hour. Therefore, multiple sets of sampling equipment are generally used for synchronous sampling. This means that during actual sampling, the sampling personnel need to carry the above three sampling devices at the same time, and the number of each sampling device is usually more than one, which makes it difficult to carry and inconvenient to use. More importantly, since the sampling equipment is not universal, it is necessary to purchase different numbers of various types of sampling equipment according to the sampling point types of different sewage treatment plants, resulting in an increase in sampling costs.

[0004] In summary, the sampling equipment in the prior art has the defects of not being universal, being inconvenient to carry and use, and having high sampling costs, and needs to be improved urgently. Summary of the invention

[0005] In order to solve the problems existing in the above-mentioned prior art, the purpose of this application is to provide a modular sampling device and method for greenhouse gases in sewage treatment plants. The modular sampling device of this application is compatible with three different sampling point types, is more convenient to carry and use, and can reduce the equipment cost of the sampling process.

[0006] The modular sampling device for greenhouse gases in a sewage treatment plant described in the present application comprises: a body having a gas collecting chamber therein;

[0007] A gas flow tube, one end of which is connected to the gas collecting chamber, and the other end of which is connected to the outside;

[0008] a gas flow meter, which is arranged on the gas flow tube and is used to detect the gas flow in the gas flow tube;

[0009] A switch valve, which is arranged on the gas flow tube and is used to control the opening and closing of the gas flow tube;

[0010] A sampling assembly, comprising a sampling pump and a sampling container, wherein the air suction end of the sampling pump is connected to the gas collecting cavity, and the air outlet end is connected to the sampling container;

[0011] An air pressure detection module, whose detection end is arranged in the gas collecting cavity, and is used to detect the internal air pressure of the gas collecting cavity;

[0012] A temperature detection module, whose detection end is arranged in the gas collecting cavity, and is used to detect the internal temperature of the gas collecting cavity;

[0013] A liquid level detection module, whose detection end is arranged in the gas collecting cavity and is used to detect the liquid level height of the gas collecting cavity;

[0014] A floating body connected to the main body and used to provide buoyancy;

[0015] A processing module, which is respectively connected to the gas flow meter, the switch valve, the sampling pump, the air pressure detection module, the temperature detection module and the liquid level detection module by signals;

[0016] The processing module determines the type of the sampling point according to the gas flow collected by the gas flow meter, and if the type of the sampling point is an aerated area, controls the modular sampling device to perform open sampling; if the type of the sampling point is a non-aerated area, controls the modular sampling device to perform closed sampling;

[0017] The open sampling comprises: placing the solenoid valve in an open state and introducing gas into the sampling container through the sampling pump;

[0018] The closed sampling includes: placing the electromagnetic valve in a closed state and introducing gas into the sampling container through the sampling pump.

[0019] Preferably, the modular sampling device further comprises:

[0020] The guide fan is arranged in the air collecting cavity, and the air flow direction is from the liquid surface to the sampling component.

[0021] Preferably, the modular sampling device further comprises:

[0022] A fixing assembly, comprising a telescopic rod and a fixing buckle, wherein one end of the telescopic rod is connected to the floating body, and the other end is connected to the fixing buckle;

[0023] An indicator light is arranged on the outer surface of the body and is connected to the processing module signal.

[0024] Preferably, the sampling container is a sampling tube and / or a sampling air bag, the sampling assembly also includes an extension tube and a sleeve, the sampling pump is detachably connected to the main body, one end of the extension tube is detachably connected to the suction end of the sampling pump, and the sleeve is detachably mounted on the outside of the extension tube.

[0025] A sampling method of the present application, using the modular sampling device as described above, comprises the following steps:

[0026] Get the type of sampling point,

[0027] In response to the sampling point being an aeration area, the switch valve of the gas flow tube is opened to connect the gas collecting cavity with the outside, the sampling pump is started to extract the gas in the gas collecting cavity into the sampling container, and the temperature information of the gas collecting cavity is collected to complete the open sampling process;

[0028] In response to the sampling point being a non-aerated area, the switch valve of the gas flow tube is closed to seal the gas collecting chamber from the outside, and multiple closed sampling actions are performed until the number of sampling times meets the requirement, thereby completing the closed sampling process;

[0029] The closed sampling action includes: starting the sampling pump to extract the gas in the gas collecting chamber into the sampling container, and collecting the liquid level height information of the gas collecting chamber, wherein the gas extracted in each closed sampling action is stored in an independent sampling container, and a certain period of time is interval between two adjacent closed sampling actions.

[0030] Preferably, before executing the open sampling process and the closed sampling process, a voltage stabilization test is performed, and if the voltage stabilization test passes, the open sampling process or the closed sampling process is executed;

[0031] The pressure stabilization test includes: making the switch valve of the gas flow tube and the guide fan both in the open state, collecting the real-time air pressure in the gas collecting chamber, and if the real-time air pressure is maintained in the target air pressure range for a certain period of time, it is judged that the pressure stabilization test has passed, otherwise it is judged that the pressure stabilization test has failed.

[0032] Preferably, when the sampling point is a fixed source discharge, the sampling pump is separated from the body, the extension tube is connected to the gas extraction end of the sampling pump, the end of the extension tube away from the sampling pump is extended to the sampling point, and the sampling pump is started to extract the gas at the sampling point into the sampling container;

[0033] If a standard sampling hole is provided at the sampling point, the sleeve is sleeved on the outside of the extension tube and inserted into the standard sampling hole, and the sampling pump is started to extract the gas at the sampling point into the sampling container.

[0034] Preferably, after obtaining the gas at the sampling point, the method further comprises:

[0035] The greenhouse gas mass concentration is calculated according to the following formula:

[0036]

[0037] Where C represents the mass concentration of greenhouse gases, C V represents the molar mass of greenhouse gas, T represents the temperature in the gas collecting chamber during sampling, and P represents the gas pressure in the gas collecting chamber during sampling;

[0038] In response to the sampling point being an aeration area, the greenhouse gas emission flux is calculated according to the following formula:

[0039] Flux a =C*Q1,

[0040] Among them, Flux a represents the greenhouse gas emission flux in the aeration area, C represents the greenhouse gas mass concentration, and Q1 represents the gas flow rate of the gas flow tube or the aeration flow rate at the sampling point;

[0041] In response to the sampling point being a non-aerated area, the greenhouse gas emission flux is calculated according to the following formula:

[0042]

[0043] Among them, Flux b represents the greenhouse gas emission flux in the non-aerated area, V represents the volume of the gas collecting chamber, A represents the cover area of ​​the gas collecting chamber on the water surface, h represents the height of the gas collecting chamber, C represents the mass concentration of greenhouse gases, and t represents the duration of the sampling process. Indicates the mass concentration release rate of greenhouse gases;

[0044] In response to the sampling point being a stationary source emission, the greenhouse gas emission flux is calculated according to the following formula:

[0045] Flux c =C*Q2,

[0046] Among them, Flux c It represents the greenhouse gas emission flux emitted by stationary sources, C represents the mass concentration of greenhouse gases, and Q2 represents the gas flow or rated flow measured by the tail gas chimney.

[0047] Preferably, the types of sampling points obtained include:

[0048] The real-time gas flow at the gas flow tube is collected. If the real-time gas flow satisfies a preset flow threshold and the duration is greater than a preset time period threshold, the type of the sampling point is determined to be an aerated area, otherwise the type of the sampling point is determined to be a non-aerated area.

[0049] Preferably, the sampling method further comprises:

[0050] Establishing a threshold dynamic adjustment model, wherein the threshold dynamic adjustment model takes the air pressure, temperature and solid content of the gas collecting chamber during sampling as inputs, and takes the flow threshold and time period threshold as outputs;

[0051] When obtaining the type of the sampling point, the air pressure, temperature and solid content of the sewage collected in real time in the gas collecting chamber are input into the threshold dynamic adjustment model to obtain the corresponding flow threshold and time period threshold under the working condition, and the obtained flow threshold and time period threshold are applied to the type judgment of the sampling point.

[0052] The modular sampling equipment for greenhouse gases in sewage treatment plants described in the present application has the advantage that, by setting a gas flow meter and a switch valve, the present application determines whether the sampling point is an aerated area or a non-aerated area according to the gas flow collected by the gas flow meter, and then controls the on-off of the switch valve, so that the gas collecting chamber is connected to the outside to form open sampling, or is closed to the outside to form closed sampling, thereby meeting the sampling requirements of different sampling points.

[0053] In addition, the sampling assembly of the present application is also equipped with a detachable sampling pump, extension tube and sleeve, and the above components can be removed to meet the sampling requirements of fixed source emissions. Therefore, the present application can be applied to the sampling process of three different sampling points. It is universal and does not require carrying multiple different types of sampling equipment when sampling. It is more convenient to carry and use and can reduce the equipment cost of the sampling process.

[0054] The present application further provides a sampling method, which uses the above-mentioned modular sampling equipment to propose sampling processes corresponding to different types of sampling points. It also combines the various parameters that can be collected by the equipment to further propose a simplified greenhouse gas emission flux calculation method, which simplifies the on-site operations of sampling personnel and helps to improve sampling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a schematic diagram of the structure of a modular sampling device described in the present application;

[0056] Figure 2 It is a schematic diagram of the matching structure of the sampling assembly and the box body described in this application;

[0057] Figure 3 It is a schematic diagram of the coordination structure between the guide fan and the box body described in the present application;

[0058] Figure 4 It is a schematic diagram of the structure of the sampling assembly described in this application when the fixed source is discharged;

[0059] Figure 5It is a structural block diagram of the modular sampling device described in this application.

[0060] Explanation of the accompanying drawings: 1-main body, 2-gas flow tube, 3-gas flow meter, 4-switch valve, 5-sampling assembly, 51-sampling pump, 52-sampling container, 521-sampling tube, 522-sampling air bag, 53-extension tube, 54-sleeve, 6-air pressure detection module, 7-temperature detection module, 8-liquid level detection module, 9-float, 91-ring buckle, 10-processing module, 11-guide fan, 12-fixing assembly, 121-telescopic rod, 122-fixing buckle, 13-indicator light. DETAILED DESCRIPTION

[0061] like Figure 1-Figure 5 As shown, the modular sampling device for greenhouse gases in a sewage treatment plant described in the present application comprises:

[0062] The main body 1 is cylindrical and hollow inside to form a gas collecting cavity.

[0063] The gas flow tube 2 is in an "L"-shaped structure, one end of which extends into the gas collecting cavity and communicates with the gas collecting cavity, and the other end extends to the side of the body 1 and communicates with the outside.

[0064] The gas flow meter 3 is arranged on the gas flow tube 2 at one end close to the body 1 and is used to detect the gas flow passing through the gas flow meter 3 .

[0065] The switch valve 4 is specifically a solenoid valve, which can be opened and closed by an electrical signal. The switch valve 4 is arranged on the gas flow tube 2, and the opening and closing of the gas flow tube 2 is controlled by the switch valve 4, thereby controlling the connection state between the gas collecting chamber and the outside, so that the gas collecting chamber is in a closed state or in a connection state with the outside.

[0066] The sampling assembly 5 includes a sampling pump 51 and a sampling container 52. The suction end of the sampling pump 51 is connected to the gas collecting cavity, and the gas outlet end is connected to the sampling container 52. When the sampling pump 51 is working, the gas in the gas collecting cavity is extracted into the sampling container 52.

[0067] The air pressure detection module 6, such as a barometer, is arranged on one side of the top surface of the body 1, and the detection end, that is, the air pressure probe, extends into the gas collecting cavity to detect the internal air pressure of the gas collecting cavity.

[0068] The temperature detection module 7, such as an electronic thermometer, is arranged on one side of the top surface of the body 1, adjacent to the air pressure detection module 6, and the detection end, that is, the temperature probe, extends into the gas collecting cavity to detect the internal temperature of the gas collecting cavity.

[0069] The liquid level detection module 8, such as an ultrasonic liquid level meter, is arranged on one side of the top surface of the body 1, adjacent to the temperature detection module 7, and the detection end, that is, the liquid level probe, extends into the gas collecting cavity to detect the liquid level in the gas collecting cavity.

[0070] The float 9, such as an inflated rubber ring, is connected to the body 1. Specifically, it is sleeved on the outside of the bottom of the body 1 to provide buoyancy so that the body 1 can float on the surface of the monitored water area.

[0071] The processing module 10 uses a processor or controller with computing capabilities, such as MCU, PLC, etc. The processing module 10 is respectively connected to the gas flow meter 3, the switch valve 4, the sampling pump 51, the air pressure detection module 6, the temperature detection module 7 and the liquid level detection module 8 for receiving detection signals from each collection end and controlling the start and stop of the switch valve 4 and the sampling pump 51.

[0072] The processing module 10 determines the type of the sampling point according to the gas flow collected by the gas flow meter 3. If the type of the sampling point is an aerated area, the modular sampling device is controlled to perform open sampling. If the type of the sampling point is a non-aerated area, the modular sampling device is controlled to perform closed sampling.

[0073] The open sampling includes: placing the solenoid valve in an open state, that is, the gas collecting chamber is in a connected state with the outside, and introducing gas into the sampling container 52 through the sampling pump 51;

[0074] The closed sampling includes: placing the solenoid valve in a closed state, that is, the gas collecting chamber and the outside are in a closed state, and introducing gas into the sampling container 52 through the sampling pump 51 .

[0075] Further, in this embodiment, if Figure 3 As shown, the modular sampling device also includes a guide fan 11. There are two guide fans 11, which are symmetrically arranged on both sides of the gas collecting chamber along the axis of the main body 1. The guide fan 11 is connected and fixed to the inner wall of the gas collecting chamber. The guide fan 11 is vertically arranged, and the air flow direction is from bottom to top, that is, from the liquid surface to the direction where the sampling component 5 is located. When the guide fan 11 is working, it can drive a uniform flow in the gas collecting chamber to achieve the effect of homogenizing the gas concentration in the gas collecting chamber.

[0076] Furthermore, in this embodiment, the modular sampling device further includes:

[0077] The fixing assembly 12 includes a telescopic rod 121 and a fixing buckle 122. One end of the telescopic rod 121 is connected to the floating body 9. For example, a plurality of ring buckles 91 are formed on the outside of the floating body 9. One end of the telescopic rod 121 has another matching ring buckle 91. The telescopic rod 121 is buckled and connected to the floating body 9 through the ring buckle 91. Specifically, the telescopic rod 121 is a multi-section sleeve structure, and the multi-section rod members are slidably sleeved in sequence, so that the overall length of the telescopic rod 121 can be adjusted telescopically to flexibly adjust according to the spacing between the deployment point and the fixing point. The fixing buckle 122 is a claw-shaped fixing buckle 122, which can be buckled and fixed on the railings and fences of the shore base, and then the body 1 is fixed at the sampling point to prevent the sampling equipment from floating and shifting.

[0078] The modular sampling device also includes an indicator light 13. There are two indicator lights 13, namely a red light and a green light, which are used to indicate different working states of the device. The indicator lights 13 are arranged on the top surface of the main body 1 and are connected to the processing module 10 by signal. The processing module 10 controls different indicator lights 13 to light up according to the sampling process to indicate the sampling state.

[0079] Further, in this embodiment, please refer to Figure 4 , the sampling container 52 is a sampling tube 521 and / or a sampling air bag 522, which is selected and set according to actual conditions. The sampling assembly 5 also includes an extension tube 53 and a sleeve 54, both of which are hollow cylindrical structures. The sampling pump 51 is detachably connected to the body 1, so that the sampling pump 51 can be removed from the body 1, one end of the extension tube 53 is detachably connected to the air extraction end of the sampling pump 51, and the sleeve 54 is detachably sleeved on the outside of the extension tube 53. When sampling fixed source emissions, the sampling pump 51 can be removed from the body 1, the extension tube 53 is connected to the air extraction end of the sampling pump 51, and then the other end of the extension tube 53 is extended into the sampling position for sampling. If there is a standard sampling point at the sampling point, the sleeve 54 is installed on the outside of the extension tube 53 for sampling. The structure of this embodiment makes the modular sampling equipment of this application applicable to sampling points of fixed source emissions in addition to aeration areas and non-aeration areas, so that this application can be applied to the existing three types of sampling points.

[0080] This embodiment also provides a method for sampling greenhouse gases in a sewage treatment plant, which is applied to the modular sampling device as described above, and includes the following steps:

[0081] Get the type of sampling point,

[0082] In response to the sampling point being the aeration area, the switch valve 4 of the gas flow tube 2 is opened to connect the gas collecting cavity with the outside, the sampling pump 51 is started to extract the gas in the gas collecting cavity into the sampling container 52, and the temperature information of the gas collecting cavity is collected to complete the open sampling process;

[0083] In response to the sampling point being a non-aerated area, the switch valve 4 of the gas flow tube 2 is closed to seal the gas collecting chamber from the outside, and multiple closed sampling actions are performed until the number of sampling times meets the requirement, thus completing the closed sampling process;

[0084] The closed sampling action includes: starting the sampling pump 51 to extract the gas in the gas collecting chamber into the sampling container 52, and collecting the liquid level height information of the gas collecting chamber, wherein the gas extracted in each closed sampling action is stored in an independent sampling container 52, and a certain period of time is interval between two adjacent closed sampling actions.

[0085] Furthermore, in this embodiment, in order to ensure the stability of the airflow during the sampling process, a voltage stabilization test is required before sampling, as follows:

[0086] Before executing the open sampling process and the closed sampling process, a voltage stabilization test is performed, and if the voltage stabilization test passes, the open sampling process or the closed sampling process is executed;

[0087] The pressure stabilization test includes: making the switch valve 4 of the gas flow tube 2 and the guide fan 11 both in the open state, collecting the real-time air pressure in the gas collecting chamber, and if the real-time air pressure is maintained in the target air pressure range for a certain period of time, it is judged that the pressure stabilization test has passed, otherwise it is judged that the pressure stabilization test has failed.

[0088] In this step, the gas collecting chamber is connected to the outside, and the guide fan 11 is started to make the gas inside the gas collecting chamber flow evenly, thereby achieving the effect of homogenizing the gas concentration in the gas collecting chamber. The real-time air pressure of the gas collecting chamber is collected and recorded as time series data. If the real-time air pressure satisfies the requirement of maintaining it in the target air pressure range for a certain period of time, for example, at the beginning of the voltage stabilization test, the air pressure value at this moment is recorded, and ±10Pa of the air pressure value is used as the target air pressure range. If the air pressure in the voltage stabilization test process, for example, is maintained within the target air pressure range for 2 minutes, it is judged that the air pressure in the gas collecting chamber is stable at this time, and subsequent sampling can be performed. Otherwise, it is judged that the air pressure is unstable and it is temporarily not suitable for sampling. Sampling can be done after the air pressure stabilizes.

[0089] Further, in this embodiment, if Figure 4 As shown, when the type of sampling point is fixed source emission, the sampling pump 51 is removed from the body 1, the extension tube 53 is connected to the gas extraction end of the sampling pump 51, and the end of the extension tube 53 away from the sampling pump 51 is extended to the sampling point, and the sampling pump 51 is started to extract the gas at the sampling point into the sampling container 52;

[0090] If a standard sampling hole is provided at the sampling point, the sleeve 54 is sleeved on the outside of the extension tube 53 , and the sleeve 54 is inserted into the standard sampling hole, and the sampling pump 51 is started to extract the gas at the sampling point into the sampling container 52 .

[0091] Furthermore, in this embodiment, after obtaining the gas at the sampling point, the method further includes:

[0092] The greenhouse gas mass concentration is calculated according to the following formula:

[0093]

[0094] Where C represents the mass concentration of greenhouse gases, C V represents the molar mass of greenhouse gas, T represents the temperature in the gas collecting chamber during sampling, and P represents the air pressure in the gas collecting chamber during sampling. It should be noted that the temperature T and the air pressure P in the gas collecting chamber during sampling can be calculated using the instantaneous temperature and air pressure at the beginning of sampling as numerical values, or by calculating the average, mode, median, etc. of the temperature and air pressure during the entire sampling process. This embodiment is not limited to this.

[0095] In response to the sampling point being an aeration area, the greenhouse gas emission flux is calculated according to the following formula:

[0096] Flux a =C*Q1,

[0097] Among them, Flux a represents the greenhouse gas emission flux in the aeration area, C represents the mass concentration of the greenhouse gas, Q1 represents the gas flow rate of the gas flow tube 2 or the aeration flow rate at the sampling point. Similarly, the gas flow rate of the gas flow tube 2 or the aeration flow rate Q1 at the sampling point can be calculated using the instantaneous value at the beginning of sampling, or the average value, mode, median, etc. of the sampling process.

[0098] In response to the sampling point being a non-aerated area, the greenhouse gas emission flux is calculated according to the following formula:

[0099]

[0100] Among them, Flux b represents the greenhouse gas emission flux in the non-aerated area, V represents the volume of the gas collecting chamber, A represents the cover area of ​​the gas collecting chamber on the water surface, h represents the height of the gas collecting chamber, C represents the mass concentration of greenhouse gases, and t represents the duration of the sampling process. Indicates the mass concentration release rate of greenhouse gases;

[0101] In response to the sampling point being a stationary source emission, the greenhouse gas emission flux is calculated according to the following formula:

[0102] Flux c =C*Q2,

[0103] Among them, Flux c represents the greenhouse gas emission flux from stationary sources, C represents the mass concentration of greenhouse gases, Q2 represents the gas flow or rated flow measured by the exhaust chimney. Similarly, the gas flow or rated flow Q2 measured by the exhaust chimney can be calculated using the instantaneous value at the beginning of sampling, or the average value, mode, median, etc. of the sampling process.

[0104] Furthermore, in this embodiment, the type of the sampling point is determined by the gas flow in the gas flow tube 2, specifically:

[0105] The real-time gas flow at the gas flow tube 2 is collected. If the real-time gas flow satisfies a preset flow threshold and the duration is greater than a preset time period threshold, the type of the sampling point is determined to be an aerated area, otherwise the type of the sampling point is determined to be a non-aerated area.

[0106] For the aerated area, since the water body is in a continuous aeration process, when other parameters, such as air pressure and the speed of the guide fan 11, are the same, the gas flow rate per unit time is usually greater than that of the non-aerated area, and there is a more obvious difference from the non-aerated area. Therefore, this indicator can be used to distinguish the aerated area from the non-aerated area, that is, by judging by a preset threshold value, if the gas flow rate is greater than the preset threshold value, it is judged as an aerated area, and if it is less than or equal to the preset threshold value, it is judged as a non-aerated area. This embodiment can effectively judge the aerated area and the non-aerated area through the gas flow rate indicator, and the judgment result is relatively accurate. The gas flow rate is the data that needs to be collected during the sampling process, and there is no need to set up other collection equipment for collection and judgment, which has good practicality.

[0107] Furthermore, in this embodiment, different water bodies and different environmental factors will have a greater impact on the gas flow rate. For example, since the gas collecting chamber is a relatively closed and small space, the temperature and air pressure in the gas collecting chamber will affect the gas flow rate collected by the gas flow meter 3 at the end of the gas flow tube 2, and the impact of environmental factors on the gas flow detection results needs to be considered. In addition, the solid content in the sewage will also affect the gas discharged after aeration, which will have a greater impact on the gas flow rate.

[0108] The modular sampling equipment of the present application needs to be applied to the diverse sampling point environments of different sewage treatment plants. If a unified flow threshold and time period threshold are used, it will be difficult to ensure accurate sampling point type judgment in water environments with large differences. If the sampling personnel calculate and adjust the threshold on site according to the actual water environment, it will affect the sampling efficiency.

[0109] Therefore, in this embodiment, a threshold dynamic adjustment model is established, wherein the threshold dynamic adjustment model takes the air pressure, temperature and solid content of the gas collecting chamber during sampling as inputs, and takes the flow threshold and time period threshold as outputs;

[0110] When obtaining the type of the sampling point, the air pressure, temperature and solid content of the sewage collected in real time in the gas collecting chamber are input into the threshold dynamic adjustment model to obtain the corresponding flow threshold and time period threshold under the working condition, and the obtained flow threshold and time period threshold are applied to the type judgment of the sampling point.

[0111] Exemplarily, using a decision tree as the threshold dynamic adjustment model includes the following steps:

[0112] Data collection: Collect sample data, which includes the air pressure, temperature, solid content of sewage and gas flow rate of the gas collecting chamber during the sampling process (the above parameters are all instantaneous values ​​at the time of sampling or the average value during the sampling process, which are selected according to the actual situation). Each set of sample data includes two sub-data, namely aeration area data and non-aeration area data. For the aeration area and non-aeration area data of the same set of data, the air pressure, temperature and solid content are the same. Take the minimum value of the gas flow rate of the aeration area data and the maximum value of the gas flow rate of the non-aeration area data during the sampling process, and take the median of the maximum and minimum values ​​as the flow threshold of the set of sample data. For the time period threshold, a difference reference value is preset according to the maximum difference in gas flow between the aerated area data and the non-aerated area data in this environment. For example, 60% or 80% of the maximum difference is taken as the difference reference value. The moment when the flow difference between the two sets of sub-data at the same moment in the sampling process is first greater than the set difference reference value is obtained, and the time period between this moment and the sampling start moment is taken as the time period threshold to ensure that the time period threshold can cover the moment when there is a significant difference between the aerated area and the non-aerated area.

[0113] It should be noted that the aforementioned sample data can be obtained through field testing, or through simulation or data expansion.

[0114] Model building: Extract features from the collected data, such as average air pressure, average temperature, percentage of solids, etc.

[0115] The decision tree model is trained using the aforementioned sample data. The model will learn how to predict the corresponding flow threshold and time period threshold based on the average air pressure, average temperature, and solid content percentage.

[0116] Through training with sample data, the model will establish a mapping relationship between air pressure, temperature, solid content and the corresponding flow threshold and time period threshold.

[0117] Real-time data input: input the real-time monitored air pressure, temperature, and solid content into the decision tree model.

[0118] Threshold prediction: The model predicts the current traffic threshold and time period threshold based on the input data.

[0119] Applying the predicted flow threshold and time period threshold to the sampling process of the working condition will enable the flow threshold and time period threshold to adapt to the working condition, and thus accurately determine the type of sampling point under the working condition.

[0120] The following will combine the above content to fully explain the sampling process of the modular sampling device of this embodiment:

[0121] One end of the safety rope is connected to a fixed place such as a railing on the shore, and the other end is connected to the buckle 91 of the floating body 9 of the sampling equipment. One end of two telescopic rods 121 (only one is shown in the figure) is respectively connected to the buckle 91 of the floating body 9 of the sampling equipment, and the sampling equipment is smoothly dropped into the water body. The fixing buckle 122 at the other end of the telescopic rod 121 is buckled to a fixed place such as a railing on the shore, and the telescopic rod 121 is extended to a length of 2-4 meters and the sampling equipment is pushed to 1 / 2 of the water corridor.

[0122] Before sampling begins, the sampling device enters the identification mode, opens the switch valve 4, and opens the gas flow meter 3. If the value of the gas flow meter 3 exceeds 200 ml / min and lasts for more than 3 minutes, the sampling device performs open sampling. If the above adjustments are not met, the sampling device performs closed sampling.

[0123] Open sampling process: the switch valve 4 is opened - the gas flow meter 3 is opened - the guide fan 11 is opened - the air pressure detection module 6 is started - the temperature detection module 7 is started - the indicator light 13 is long red - after 5 minutes, the air pressure detection module 6 and the sampling pump 51 are linked to open - if the air pressure detection module 6 maintains a fluctuation of no more than ±10Pa for 2 minutes, the air pressure count value at this time is stored - the gas flow meter 3, stores the value of the gas flow meter 3 at this time - the temperature count value at this time is stored - the signal light is long green - the sampling pump 51 is started for 15s, and the gas in the main body 1 is extracted to the sampling gas bag 522 - the air extraction is completed, and the sampling pump 51 stops sampling - 5min waiting time - the green marked steps are cycled twice - a total of 3 gas samples are collected, and the sampling is completed.

[0124] Closed sampling process: the switch valve 4 opens - the gas flow meter 3 opens - the guide fan 11 opens - the air pressure detection module 6 starts - the temperature detection module 7 starts - the indicator light 13 stays red - after 5 minutes, the air pressure detection module 6 and the sampling pump 51 are linked to open - if the air pressure detection module 6 maintains a fluctuation of no more than ±10Pa for 2 minutes - the signal light stays green - the switch valve 4 closes - the gas flow meter 3 closes - the temperature and air pressure are stored - the gas sampling pump 51 starts to extract gas samples to gas sampling bag No. 1, and the liquid level detection module 8 records that the liquid level height is No. 1 at this time - the gas sampling pump 51 is turned off - 10 minutes of waiting time - the temperature and air pressure are stored - the gas sampling pump 51 starts to extract gas samples to gas sampling bag No. 2, and the liquid level detection module 8 records that the liquid level height is No. 2 at this time - the gas sampling pump 51 is turned off - the cycle is repeated in sequence until the No. 6 gas sampling bag is completed - the signal light flashes red, indicating the end of sampling.

[0125] The stationary source emissions and subsequent greenhouse gas emission fluxes are the same as those described above and can be understood by referring to the above description and will not be elaborated here.

[0126] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application.

[0127] For those skilled in the art, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all of these changes and deformations should fall within the protection scope of the claims of this application.

Claims

1. A modular sampling device for greenhouse gases in sewage treatment plants, characterized in that: include: A main body having a gas collecting cavity therein; A gas flow tube, one end of which is connected to the gas collecting chamber, and the other end of which is connected to the outside; a gas flow meter, which is arranged on the gas flow tube and is used to detect the gas flow in the gas flow tube; A switch valve, which is arranged on the gas flow tube and is used to control the opening and closing of the gas flow tube; A sampling assembly, comprising a sampling pump and a sampling container, wherein the air suction end of the sampling pump is connected to the gas collecting cavity, and the air outlet end is connected to the sampling container; An air pressure detection module, whose detection end is arranged in the gas collecting cavity, and is used to detect the internal air pressure of the gas collecting cavity; A temperature detection module, whose detection end is arranged in the gas collecting cavity, and is used to detect the internal temperature of the gas collecting cavity; A liquid level detection module, whose detection end is arranged in the gas collecting cavity and is used to detect the liquid level height of the gas collecting cavity; A floating body connected to the main body and used to provide buoyancy; A processing module, which is respectively connected to the gas flow meter, the switch valve, the sampling pump, the air pressure detection module, the temperature detection module and the liquid level detection module by signals; The processing module determines the type of the sampling point according to the gas flow collected by the gas flow meter, and if the type of the sampling point is an aerated area, controls the modular sampling device to perform open sampling; if the type of the sampling point is a non-aerated area, controls the modular sampling device to perform closed sampling; The open sampling comprises: placing the solenoid valve in an open state and introducing gas into the sampling container through the sampling pump; The closed sampling includes: placing the electromagnetic valve in a closed state and introducing gas into the sampling container through the sampling pump.

2. The modular sampling device for greenhouse gases in sewage treatment plants according to claim 1, characterized in that: Also includes: The guide fan is arranged in the air collecting cavity, and the air flow direction is from the liquid surface to the sampling component.

3. The modular sampling device for greenhouse gases in sewage treatment plants according to claim 1, characterized in that: Also includes: A fixing assembly, comprising a telescopic rod and a fixing buckle, wherein one end of the telescopic rod is connected to the floating body, and the other end is connected to the fixing buckle; An indicator light is arranged on the outer surface of the body and is connected to the processing module signal.

4. The modular sampling device for greenhouse gases in sewage treatment plants according to claim 1, characterized in that: The sampling container is a sampling tube and / or a sampling air bag, and the sampling assembly also includes an extension tube and a sleeve. The sampling pump is detachably connected to the main body, one end of the extension tube is detachably connected to the air suction end of the sampling pump, and the sleeve is detachably mounted on the outside of the extension tube.

5. A method for sampling greenhouse gases in a sewage treatment plant, using the modular sampling device according to any one of claims 1 to 4, characterized in that: The following steps are involved: Get the type of sampling point, In response to the sampling point being an aeration area, the switch valve of the gas flow tube is opened to connect the gas collecting cavity with the outside, the sampling pump is started to extract the gas in the gas collecting cavity into the sampling container, and the temperature information of the gas collecting cavity is collected to complete the open sampling process; In response to the sampling point being a non-aerated area, the switch valve of the gas flow tube is closed to seal the gas collecting chamber from the outside, and multiple closed sampling actions are performed until the number of sampling times meets the requirement, thereby completing the closed sampling process; The closed sampling action includes: starting the sampling pump to extract the gas in the gas collecting chamber into the sampling container, and collecting the liquid level height information of the gas collecting chamber, wherein the gas extracted in each closed sampling action is stored in an independent sampling container, and a certain period of time is interval between two adjacent closed sampling actions.

6. The sampling method according to claim 5, characterized in that: Before executing the open sampling process and the closed sampling process, a voltage stabilization test is performed, and if the voltage stabilization test passes, the open sampling process or the closed sampling process is executed; The pressure stabilization test includes: making the switch valve of the gas flow tube and the guide fan both in the open state, collecting the real-time air pressure in the gas collecting chamber, and if the real-time air pressure is maintained in the target air pressure range for a certain period of time, it is judged that the pressure stabilization test has passed, otherwise it is judged that the pressure stabilization test has failed.

7. The sampling method according to claim 5, characterized in that: When the sampling point is a fixed source emission, the sampling pump is separated from the body, the extension tube is connected to the gas extraction end of the sampling pump, the end of the extension tube away from the sampling pump is extended to the sampling point, and the sampling pump is started to extract the gas at the sampling point into the sampling container; If a standard sampling hole is provided at the sampling point, the sleeve is sleeved on the outside of the extension tube and inserted into the standard sampling hole, and the sampling pump is started to extract the gas at the sampling point into the sampling container.

8. The sampling method according to claim 7, characterized in that: After obtaining the gas at the sampling point, it also includes: The greenhouse gas mass concentration is calculated according to the following formula: Where C represents the mass concentration of greenhouse gases, C V represents the molar mass of greenhouse gas, T represents the temperature in the gas collecting chamber during sampling, and P represents the gas pressure in the gas collecting chamber during sampling; In response to the sampling point being an aeration area, the greenhouse gas emission flux is calculated according to the following formula: Flux a =C*Q1, Among them, Flux a represents the greenhouse gas emission flux in the aeration area, C represents the greenhouse gas mass concentration, and Q1 represents the gas flow rate of the gas flow tube or the aeration flow rate at the sampling point; In response to the sampling point being a non-aerated area, the greenhouse gas emission flux is calculated according to the following formula: Among them, Flux b represents the greenhouse gas emission flux in the non-aerated area, V represents the volume of the gas collecting chamber, A represents the cover area of ​​the gas collecting chamber on the water surface, h represents the height of the gas collecting chamber, C represents the mass concentration of greenhouse gases, and t represents the duration of the sampling process. Indicates the mass concentration release rate of greenhouse gases; In response to the sampling point being a stationary source emission, the greenhouse gas emission flux is calculated according to the following formula: Flux c =C*Q2, Among them, Flux c It represents the greenhouse gas emission flux emitted by stationary sources, C represents the mass concentration of greenhouse gases, and Q2 represents the gas flow or rated flow measured by the tail gas chimney.

9. The sampling method according to claim 5, characterized in that: The types of sampling points include: The real-time gas flow at the gas flow tube is collected. If the real-time gas flow satisfies a preset flow threshold and the duration is greater than a preset time period threshold, the type of the sampling point is determined to be an aerated area; otherwise, the type of the sampling point is determined to be a non-aerated area.

10. The sampling method according to claim 9, characterized in that: Also includes: Establishing a threshold dynamic adjustment model, wherein the threshold dynamic adjustment model takes the air pressure, temperature and solid content of the gas collecting chamber during sampling as inputs, and takes the flow threshold and time period threshold as outputs; When obtaining the type of the sampling point, the air pressure, temperature and solid content of the sewage collected in real time in the gas collecting chamber are input into the threshold dynamic adjustment model to obtain the corresponding flow threshold and time period threshold under the working condition, and the obtained flow threshold and time period threshold are applied to the type judgment of the sampling point.

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