A landfill methane long-term monitoring static chamber device and method

Abstract

The application discloses a landfill methane long-term monitoring static box device and method, and relates to the technical field of landfill methane emission monitoring. The device comprises a bottom-opened box, a gas conveying unit, a gas mixing unit, a one-way low-pressure pressure relief valve, a detection module, a power supply unit and a control system. The method comprises a deployment, initialization and monitoring stage, and can calculate the methane emission rate by automatically injecting air, mixing gas, collecting data and transmitting. The device and method realize automatic and long-term continuous monitoring, synchronously acquire multi-dimensional parameters, improve monitoring efficiency and data continuity, solve the problems of traditional static boxes, such as dependence on manual operation and single data dimension, and provide data support for emission reduction strategies.

Description

Technical Field

[0001] This invention relates to the field of environmental monitoring technology for methane emissions from landfills, specifically to a static monitoring device and method for long-term methane monitoring in landfills. Background Technology

[0002] Methane (CH4) is the second largest greenhouse gas after carbon dioxide (CO2), with a global warming potential (GWP) 28 times that of CO2 on a centennial timescale. Meanwhile, methane has a relatively short atmospheric lifetime (approximately 12 years), meaning that effective methane emission reductions can significantly slow the rate of global warming in a short period, which is crucial for achieving climate goals. Municipal solid waste landfills are one of the main sources of anthropogenic methane emissions. Therefore, accurate and efficient monitoring and quantification of landfill methane emission fluxes are of great practical significance for developing effective emission reduction strategies and promoting the green and low-carbon development of the waste management industry.

[0003] Current site monitoring of methane in landfills, both domestically and internationally, mainly focuses on methods such as inventory methods, static containers, drones, or satellites.

[0004] The inventory method estimates methane production based on models (such as the first-order decay model recommended by the IPCC). This method is relatively simple to calculate and suitable for large-scale assessments. However, its core limitation lies in the fact that the model relies on pre-set and usually constant key parameters (such as methane yield potential and degradation rate constant), while these parameters vary significantly with waste composition, degradation stage, and environmental conditions (temperature, moisture) in actual landfills. This leads to considerable uncertainty in the estimation results, making it difficult to reflect the true spatiotemporal emission characteristics of the site.

[0005] The static chamber method is currently the most widely used method for testing the intensity of gas releases at sites. Its principle is clear, its operation is relatively simple, and the measurement results are highly representative (reflecting emissions only at the test site). However, the traditional static chamber method suffers from the following major bottlenecks that severely restrict its large-scale, long-term application: 1. High dependence on manual operation: The entire process, including setup, sealing, gas mixing, sampling, reading, and dismantling, must be completed manually on-site. This not only consumes significant manpower and time costs but is also difficult to implement in adverse weather or complex terrain conditions. 2. Low monitoring frequency and poor data continuity: Limited by manpower, measurements are typically only performed discretely and for short periods (e.g., several hours), making it difficult to capture diurnal and seasonal variations in methane emissions, as well as instantaneous emission events triggered by environmental factors (e.g., sudden changes in temperature and pressure). 3. Limited information dimensions: Primarily acquiring methane concentration or flux data, lacking synchronous environmental parameters closely related to the emission process (e.g., chamber temperature and humidity, atmospheric pressure) and precise location information (GPS), limiting in-depth analysis of emission patterns and driving factors.

[0006] UAV / satellite remote sensing: This method can quickly acquire methane column concentration information at the regional scale of landfills and estimate total emissions. Its main limitations are: High weather dependence: Inversion accuracy is greatly affected by meteorological conditions such as wind speed, wind direction, and atmospheric stability. Insufficient spatial resolution: It is difficult to accurately locate emission hotspots (especially for landfills with non-uniform emissions), and the resolution is far lower than that of ground point source measurements (such as static bins). Limited temporal continuity: Constrained by UAV endurance, flight permits, and satellite revisit cycles (usually several days to several weeks), it is difficult to achieve high-frequency, long-term continuous monitoring.

[0007] In summary, the core challenges facing existing landfill methane monitoring technologies are as follows: Inventory method: High uncertainty due to model parameterization makes it difficult to meet the needs of accurate monitoring. Static box method (the mainstream ground-based method): Heavily reliant on manual labor, inefficient, unable to operate continuously for long periods, and with limited data dimensions, restricting its application in large-scale, high-frequency, and long-term monitoring. UAV / satellite method: Insufficient spatiotemporal resolution and continuity, and sensitive to meteorological conditions, making it difficult to replace accurate measurements from ground point sources.

[0008] Therefore, in the field of refined monitoring of methane emissions from landfills, there is an urgent need for an innovative technological solution that can overcome the aforementioned limitations, particularly addressing key issues such as the strong reliance on manual labor, the inability to operate continuously and automatically for extended periods, and the lack of simultaneous acquisition of multi-dimensional environmental information in traditional static container methods. Developing intelligent static container devices with autonomous operation, environmental sensing, automatic sampling, and long-term monitoring capabilities is an inevitable trend and an urgent requirement for improving the efficiency, data quality, and spatiotemporal coverage of methane emission monitoring in landfills. Summary of the Invention

[0009] To address the core shortcomings of existing landfill methane monitoring technologies, particularly the traditional static chamber method, which heavily relies on manual operation, cannot operate continuously for extended periods, and struggles to simultaneously acquire multi-dimensional environmental information, this invention provides a static chamber device and method for long-term methane monitoring in landfills, incorporating environmental sensing and automatic sampling capabilities. Its purpose is to completely replace cumbersome manual operation procedures, enabling long-term autonomous deployment of the device within the landfill environment. It automatically acquires high spatiotemporal resolution methane emission concentration / flux data, and simultaneously collects key environmental parameters (temperature, humidity, atmospheric pressure) and location information (GPS). This data is transmitted remotely for analysis, ultimately providing reliable data support for precise methane emission reduction in landfills.

[0010] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0011] In a first aspect, the present invention provides a static monitoring box device for long-term methane monitoring in landfills, the static monitoring box device comprising:

[0012] The container is a sealed container with an open bottom and a wedge-shaped bottom edge, designed to be embedded in landfill cover soil or exposed waste piles.

[0013] A gas delivery unit, located at the top of the housing, is configured to perform the following operations: (a) injecting outside air into the housing, or (b) extracting gas from the housing;

[0014] A one-way low-pressure relief valve is located on the upper part of the side wall of the box, which is used to automatically open when a slight positive pressure is generated inside the box to discharge excess gas.

[0015] A gas mixing unit is located inside the housing and is used to mix the gases inside the housing;

[0016] The detection module is located on the top and / or side wall of the enclosure and is used to detect environmental parameters such as temperature and humidity, atmospheric pressure and methane concentration inside the enclosure, as well as the location information of the enclosure in real time.

[0017] A power supply unit is used to supply power to the static box device;

[0018] The control system, electrically connected to the gas delivery unit, gas mixing unit, and detection module, is configured as follows:

[0019] Start the gas delivery unit to perform operation (a) until the methane concentration is below a predetermined threshold;

[0020] The gas mixing unit is activated periodically, and environmental parameters and location information are collected using the detection module.

[0021] The collected environmental parameters and location information are transmitted to a remote server or cloud platform;

[0022] The gas delivery unit is controlled to perform operation (b) to sample the gas inside the chamber.

[0023] As a further optimization of the present invention, the gas delivery unit includes a miniature air pump with multiple interfaces. The first interface of the miniature air pump is connected to the atmosphere, the second interface is connected to the interior of the housing, and the third interface is connected to a gas collection device. The miniature air pump is configured to perform the following: draw fresh air from the atmosphere through the first interface and pump it into the interior of the housing through the second interface, or draw gas from the interior of the housing to the gas collection device through the second interface.

[0024] As a further optimization of the present invention, a one-way valve and a filter device are provided on the connection passage between the third interface and the gas collection device.

[0025] As a further optimization of the present invention, the gas mixing unit includes a horizontal support rod and a mixing fan. One end of the horizontal support rod is connected to the inner side wall of the box, and the other end is connected to the mixing fan. The mixing fan is located in the center of the box.

[0026] As a further optimization of the present invention, the detection module includes a thermometer and hygrometer, a pump-type methane detector, a GPS recorder and a barometer integrated on the top and / or side wall of the housing.

[0027] As a further optimization of the present invention, the power supply unit includes a solar panel and an energy storage battery, which is used to supply power to the electrical equipment of the static box device.

[0028] As a further optimization of the present invention, a flexible sealing skirt is provided on the lower outer side of the box body for sealing and isolating the box body from the ground surface.

[0029] As a further optimization of the present invention, a flexible sealing skirt is provided on the lower outer side of the box body. The flexible sealing skirt includes a flexible body that surrounds and is fixed to the lower outer side of the box body. The side surface of the flexible body that contacts the ground surface is constructed as at least one of the following structures: a smooth surface for enhancing the adhesion to a flat ground surface, or a textured or wrinkled surface for enhancing the interlocking ability with an irregular ground surface.

[0030] As a further optimization of the present invention, the box body is provided with an auxiliary anchoring structure, which includes multiple mooring rings located on the upper part of the box body, multiple ground anchors that can be driven into the ground around the box body, multiple steel wire ropes corresponding to and connecting the mooring rings and the ground anchors, and a tensioner located on the steel wire ropes for tightening the steel wire ropes.

[0031] Secondly, the present invention provides a method for long-term monitoring of methane in landfills, employing the aforementioned static chamber device, comprising the following steps:

[0032] During the deployment phase, the wedge-shaped edge at the bottom of the enclosure is embedded into the ground surface and sealed using a flexible sealing skirt.

[0033] During the initialization phase, outside air is injected into the chamber using a gas delivery unit until the methane concentration is below a predetermined threshold. During the injection process, the one-way low-pressure relief valve automatically opens to discharge excess gas from the chamber and balance the pressure inside the chamber with the outside atmosphere.

[0034] During the monitoring phase, the following operations will be performed periodically:

[0035] The gas mixing unit is started at a preset time interval to mix the gas. During the mixing process, the one-way low-pressure relief valve is automatically opened to discharge excess gas in the box and balance the pressure difference between the box and the outside atmosphere.

[0036] After mixing, data on methane concentration, temperature and humidity, atmospheric pressure, and location are collected.

[0037] The collected data is transmitted to a remote server or cloud platform;

[0038] The sampling procedure involves extracting gas from the chamber as needed and storing it in a gas collection device.

[0039] As a further optimization of the present invention, the formula for calculating the methane emission rate from landfills is as follows:

[0040]

[0041] Where: Q is the methane emission rate, in g / (m³). 2 ·min); This is the absolute atmospheric pressure during the testing period, in Pa. The value is the molar mass of methane, 16 g / mol; V is the static tank volume, in m³. 3 A is the static box area, in meters. 2 R is the gas constant, 8.314 J / (K·mol); T is the temperature during the test, in K. This is the concentration gradient of CH4 within the static chamber, in minutes. -1 .

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. Achieve automation and long-term continuous monitoring, significantly reducing reliance on manual labor. Through the linkage of the gas delivery unit, gas mixing unit, and control system, gas injection, mixing, sampling, and data acquisition are completed automatically without the need for on-site manual operation. This allows for long-term unattended operation and overcomes the shortcomings of traditional static chamber methods, which rely on manual labor and are difficult to implement under harsh conditions.

[0044] 2. Improve the accuracy and representativeness of monitoring data. The wedge-shaped bottom of the chamber is embedded in the ground, and the flexible sealing skirt adapts to flat / irregular ground surfaces. Combined with the auxiliary anchoring structure, downward pressure is applied to enhance the seal, ensuring the stability of the device and reducing external interference. The gas mixing unit forces the gas in the chamber to mix, eliminating the effects of stratification. Combined with environmental parameters such as temperature, humidity, and air pressure collected synchronously by the detection module, the calculation of methane concentration and emission rate is more accurate.

[0045] 3. Enriched data dimensions and spatiotemporal continuity. The detection module simultaneously acquires methane concentration, environmental parameters, and location information, providing multi-dimensional data for analyzing emission patterns and driving factors; timed monitoring and remote data transmission enable high-frequency, long-term continuous monitoring, capturing daily, seasonal, and instantaneous changes in methane emissions, overcoming the problem of poor data continuity in traditional methods.

[0046] 4. Adaptable to complex field environments, ensuring long-term stable operation. The solar power unit meets long-term power supply needs in the field, eliminating the need for manual power supply replacement. The flexible sealing skirt and auxiliary anchoring structure adapt to both flat and irregular ground surfaces, improving sealing reliability and the device's anti-interference capability, ensuring continuous and stable monitoring. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the static monitoring box device for long-term methane monitoring in landfills according to the present invention.

[0048] Figure 2 This is a side view schematic diagram of the auxiliary anchoring structure for the present invention.

[0049] Figure 3 This is a top view schematic diagram of the auxiliary anchoring structure for the present invention.

[0050] In the diagram: 1-box body, 11-wedge structure, 12-one-way low-pressure relief valve, 2-gas delivery unit, 21-micro air pump, 22-gas collection device, 3-gas mixing unit, 31-lateral support rod, 32-mixing fan, 4-temperature and humidity meter, 5-pump-type methane detector, 6-GPS recorder, 7-barometer, 8-power supply unit, 9-flexible sealing skirt, 91-flexible main body, 10-auxiliary anchoring structure, 101-mooring ring, 102-ground anchor, 103-wire rope, 104-tensioner. Detailed Implementation

[0051] To enable those skilled in the art to better understand the technical solutions of the present invention, preferred embodiments of the present invention are described below in conjunction with specific examples. However, it should be understood that the accompanying drawings are for illustrative purposes only and should not be construed as limiting the present invention. For better illustration of this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. For those skilled in the art, the omission of certain well-known structures and their descriptions in the drawings is understandable. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting the present invention.

[0052] like Figure 1 As shown, this embodiment provides a static monitoring device for long-term methane monitoring in landfills, featuring environmental sensing and automatic sampling capabilities. It mainly includes a housing 1, a gas delivery unit 2, a gas mixing unit 3, a one-way low-pressure relief valve 12, a detection module, a power supply unit 8, and a control system. This static monitoring device can be deployed in the landfill cover layer or other exposed soil areas, and is suitable for unattended gas monitoring tasks for continuous periods of several days or months.

[0053] In some embodiments, the container 1 is an integral metal container 1 with an opening at the bottom and a bottom edge designed as an acute-angle contact edge, and is configured as a wedge-shaped structure 11 for embedding into the landfill cover soil layer or exposed waste pile.

[0054] Furthermore, in order to ensure good airtightness, a flexible sealing skirt 9 is provided on the lower outer side of the box 1 as a sealing structure. When the box 1 is embedded in the ground, the flexible sealing skirt 9 fits tightly with the ground, realizing a reliable seal and isolation between the inside of the box 1 and the outside atmosphere.

[0055] Specifically, the flexible sealing skirt 9 includes a flexible body 91 that surrounds and is fixed to the outer side of the acute-angled edge of the lower part of the box-type main body. The flexible body 91 is made of a weather-resistant, highly elastic, and chemically resistant polymer material, such as EPDM rubber or polyolefin elastomer. The inner side of the flexible body 91 is fixed to the lower edge of the box 1 with rivets, making it difficult to shift or be disturbed by external forces. This device enhances the sealing effect of the skirt and ensures long-term stability. When the box 1 is embedded in the ground, the skirt, due to its flexibility, can adaptively and tightly conform to the landfill cover soil layer or irregular ground surface such as HDPE geomembrane, forming a reliable airtight barrier to achieve reliable sealing and isolation between the inside of the box 1 and the outside atmosphere.

[0056] To further optimize the sealing effect and adapt to different surface conditions, the side of the flexible sealing skirt 9 that contacts the ground surface is specially designed: when the device is applied to flat surfaces such as HDPE geomembranes, this contact surface can be designed as a smooth surface to maximize the bonding area and facilitate the use of structural adhesive for bonding and sealing; when the device is applied to irregular surfaces such as soil, sand and gravel, it can be designed as a textured surface with rings or meshes, or even a wrinkled surface with pre-set folds, to significantly enhance the mechanical interlocking force with the ground surface and effectively fill the tiny gaps caused by uneven ground surfaces.

[0057] In some embodiments, the gas delivery unit 2 is disposed on the top of the housing 1 and is configured to perform the following operations: (a) injecting outside air into the housing 1, or (b) extracting gas from the housing 1.

[0058] Specifically, the gas delivery unit 2 includes a multi-port miniature air pump 21. The first port of the miniature air pump 21 is connected to the atmosphere (for drawing in fresh air), the second port is connected to the interior of the housing 1, and the third port is connected to the gas collection device 22 (or can be connected to the inlet of the pump-suction methane detector 5). The miniature air pump 21 is configured to selectively perform the following actions by means of a control valve or the flow direction control of the pump itself: (a) drawing in fresh air from the atmosphere through the first port and pumping it into the interior of the housing 1 through the second port, or (b) drawing gas from the interior of the housing 1 to the gas collection device 22 through the second port. The gas collection device 22 can be a portable gas collection bag.

[0059] Furthermore, a particulate filter and a one-way valve are installed on the passage connecting the gas collection device 22 or the pump-type methane detector 5 to the third interface of the micro air pump 21 to effectively prevent impurities or water vapor in the chamber from entering the sampling system or detector, protecting the equipment and ensuring sample / measurement quality.

[0060] In some embodiments, a one-way low-pressure relief valve 12 is located on the upper side wall of the housing 1. To address the issue of increased internal pressure due to gas injection or infiltration during purging or monitoring, and to ensure the accuracy of measurement data, this valve has an extremely low opening pressure threshold. It automatically opens only when a slight positive pressure is generated inside the housing relative to the external atmosphere, releasing excess gas. Once the pressure difference between the inside and outside disappears, it immediately closes to maintain pressure balance between the inside of the housing and the external atmosphere.

[0061] In some embodiments, the gas mixing unit 3 is disposed inside the housing 1 and is used to mix the gas inside the housing 1.

[0062] Specifically, the gas mixing unit 3 includes a horizontal support rod 31 and a mixing fan 32. One end of the horizontal support rod 31 is connected to the inner wall of the housing 1, and the other end is connected to the mixing fan 32, which is located in the center of the housing 1. The mixing fan 32 is driven by a low-power DC motor, and its function is to start before each gas concentration reading or sampling, run for a preset time (e.g., 30 seconds), forcefully mix the gas in the housing, eliminate gas stratification caused by density differences, and ensure the representativeness of the measured gas and the accuracy of the data.

[0063] Furthermore, the gas mixing unit 3 (such as the fan motor) and all electrical components inside the enclosure are designed to be intrinsically safe or explosion-proof, and ensure that the surface temperature generated during operation is lower than the ignition temperature of methane. This fundamentally eliminates the risk of combustion and explosion caused by the methane concentration inside the enclosure reaching the lower explosive limit (LEL), ensuring safe operation in potentially hazardous environments.

[0064] In some embodiments, the detection module is located on the top and / or side wall of the enclosure 1, and is used to detect environmental parameters such as temperature and humidity, atmospheric pressure and methane concentration inside the enclosure 1, as well as the location information of the enclosure 1 in real time.

[0065] Specifically, the detection module includes a thermometer and hygrometer 4 and a pump-type methane detector 5 integrated on the top of the enclosure 1, as well as a GPS recorder 6 and a barometer 7 integrated on the side wall of the enclosure 1. The GPS recorder 6 can record the latitude and longitude of the sampling point in real time for monitoring location calibration and trajectory management.

[0066] In some embodiments, the power supply unit 8 is used to supply power to the static box device.

[0067] Specifically, power supply unit 8 includes a solar panel, a lithium battery, and a transmission line. The solar panel can be placed in a sunny location depending on the specific location of the static box. It is connected to the lithium battery through the transmission line to drive the static box to monitor methane at night or on cloudy or rainy days, thus achieving continuous operation day and night.

[0068] In some embodiments, the control system is electrically connected to the gas delivery unit 2, the gas mixing unit 3, and the detection module. The control system includes a programmable logic control module for implementing timed start-up of the monitoring process, controlling the start / stop and duration of the mixing fan 32, and synchronously recording environmental parameters and location information. The control system integrates a wireless communication module, supporting at least one remote data transmission protocol among LoRa, NB-IoT, 4G / 5G, or Wi-Fi.

[0069] The control system is configured as follows:

[0070] Start gas delivery unit 2 to perform operation (a) until the methane concentration is below a predetermined threshold;

[0071] The gas mixing unit 3 is activated periodically, and environmental parameters and location information are collected using the detection module.

[0072] The collected environmental parameters and location information are transmitted to a remote server or cloud platform;

[0073] The gas delivery unit 2 is controlled to perform operation (b) to sample the gas inside the housing 1.

[0074] Furthermore, such as Figure 2 and Figure 3 As shown, to ensure the long-term stability of the device in the field, an auxiliary anchoring structure 10 is provided on the outer edge of the housing 1. This structure fundamentally changes the traditional direct fixing method. It consists of four mooring rings 101 set on the side wall of the housing 1, several independently driven ground anchors 102 around the device, and steel wire ropes 103 connecting the two. Each steel wire rope 103 is equipped with a tensioner 104 (such as a turnbuckle). During installation, by tightening the tensioner 104, the steel wire rope 103 applies a strong and continuous downward pressure to the housing 1. This design not only firmly fixes the device in place, effectively resisting external interference such as wind, but the resulting downward pressure also actively acts on the flexible sealing skirt 9, making it fit more tightly with the ground, thus significantly improving the reliability and durability of the seal.

[0075] Based on the structural design of the static box device described above, this embodiment provides a method for long-term methane monitoring in landfills, comprising the following steps:

[0076] (1) Deployment phase: The bottom wedge edge of the box 1 is embedded into the ground and sealed by the flexible sealing skirt 9.

[0077] Specifically, with the opening of container 1 facing downwards, first clean the surface of the deployment point to remove debris, ensuring the surface is as flat as possible and preventing foreign objects from entering the static container. Place the static container at the deployment point, using its own weight or external force to bury the bottom sharp-angled contact edge 10-15cm into the soil or inside the waste. Then, tidy and compact the flexible sealing skirt 9 surrounding the bottom of container 1, allowing it to fully conform to the ground surface due to its flexibility. For soil-covered landfills, clay can be compacted and sealed along the outer edge of the skirt to enhance airtightness; for HDPE membrane-covered areas, a ring of structural adhesive can be applied to the contact surface between the skirt and the membrane to achieve the best sealing effect.

[0078] Subsequently, select at least three (preferably 3-4, symmetrically distributed) stable points on the ground around the device, and drive the individual ground anchors 102 into the ground using tools such as heavy hammers to ensure sufficient pull-out resistance. Connect one end of the steel wire rope 103 to the hanging ring of the ground anchor 102, and the other end passes through the tethering ring 101 on the upper part of the box 1 and connects to the tensioner 104. Rotate and tighten the tensioners 104 in each direction one by one, and observe that the steel wire rope 103 gradually tightens and generates a significant downward pressure on the box 1. Ensure that the tension in each direction is balanced so that the box 1 is horizontally and stably pressed into the ground. Drive ground nails or anchor piles into the ground through the through holes in the auxiliary anchoring structure 10 located on the outer edge of the box 1 to firmly fix the entire device in place.

[0079] Through the above-mentioned tensioning and anchoring operation, the entire device is firmly fixed at the monitoring point, which can not only effectively resist the impact of severe weather, but also ensure that the flexible sealing skirt 9 can maintain the best airtight state throughout the entire long-term monitoring cycle with its continuous downward pressure.

[0080] (2) Initialization phase: Before the formal monitoring begins, the control system operates the micro air pump 21 to perform operation (a), first pumping fresh outside air into the static chamber. During this purging process, the pressure inside the chamber tends to rise due to the continuous pumping of fresh air. At this time, the one-way low-pressure relief valve 12 automatically opens to discharge excess mixed gas in the chamber, so that the entire purging process can be carried out efficiently under near-normal pressure conditions. At the same time, the pump-suction methane monitor located at the top begins to monitor the methane concentration in the chamber. Once the methane concentration is lower than the limit set by the operator (which can be set to 100 ppm), the micro air pump 21 is stopped, and the monitoring preparation is completed.

[0081] (3) Monitoring and sampling stage:

[0082] At the start of monitoring, the control system records the initial methane concentration in the static chamber, along with external temperature, humidity, atmospheric pressure, and the static chamber's latitude and longitude. A monitoring cycle is initiated at preset time intervals (approximately 5 minutes). At the beginning of each cycle, the gas mixing unit 3 is activated and runs for a preset time to mix the gas inside the chamber. During mixing, as methane gas from the landfill continuously seeps into the chamber from the surface, the gas volume inside tends to increase. At this point, the one-way low-pressure relief valve 12 again plays a crucial role, automatically and in real-time expelling the excess gas volume generated by gas seepage, ensuring that the pressure inside the chamber remains dynamically balanced with the external atmospheric pressure, resulting in higher detection accuracy. After mixing is complete, the methane concentration, temperature, humidity, atmospheric pressure, GPS location, and timestamp are read and recorded. Once the operator-set detection time (20 minutes / 30 minutes) is reached, detection stops, and the control system transmits the collected data to a remote server or cloud platform via an integrated wireless communication module. The server or cloud platform can receive remote commands to adjust monitoring parameters (such as interval time), initiate real-time sampling, or execute specific tasks.

[0083] Furthermore, flux calculation: After obtaining the methane concentration change rate every five minutes, the methane emission rate in this region can be calculated using the following formula.

[0084]

[0085] Where: Q is the methane emission rate, in g / (m³). 2 ·min); This is the absolute atmospheric pressure during the testing period, in Pa. The value is the molar mass of methane, 16 g / mol; V is the static tank volume, in m³. 3 A is the static box area, in meters. 2 R is the gas constant, 8.314 J / (K·mol); T is the temperature during the test, in K. This is the concentration gradient of CH4 within the static chamber, in minutes. -1 The methane concentration change curve is generated by collecting data, and its value can be obtained by fitting the curve.

[0086] Sampling: During static chamber monitoring, the control system can operate a miniature air pump to sample the gas inside the static chamber. Optionally or by instruction, the miniature air pump can be controlled to perform operation (b) to pump the gas out of the chamber: it can be directly guided to a pump-suction methane detector for immediate high-precision detection, or guided to a portable gas collection bag for gas sample preservation for subsequent laboratory analysis.

[0087] In summary, this invention enables automated, long-term, and multi-parameter (concentration, flux, environmental information, location) synchronous monitoring of methane emissions from landfills, significantly improving monitoring efficiency and the spatiotemporal continuity of data.

[0088] Based on the description and accompanying drawings of this invention, those skilled in the art can easily manufacture or use the static monitoring device and method for long-term methane monitoring in landfills according to this invention, and can achieve the positive effects described in this invention.

[0089] Unless otherwise specified, in this invention, terms such as "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe orientation or positional relationships in this invention are for illustrative purposes only and should not be construed as limiting this invention. For those skilled in the art, the specific meaning of the above terms can be understood in conjunction with the accompanying drawings and according to the specific circumstances.

[0090] Unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" in this invention should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0091] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A static monitoring box device for long-term methane monitoring in landfills, characterized in that, The static box device includes: The container (1) is a sealed container with an open bottom and a wedge-shaped structure (11) at the bottom edge, which is used to embed into the landfill cover soil layer or the exposed waste pile. A gas delivery unit (2), located on top of the housing (1), is configured to perform the following operations: (a) injecting outside air into the housing (1), or (b) extracting gas from the housing (1); A one-way low-pressure relief valve (12) is located on the upper side wall of the box (1) and is used to automatically open when a slight positive pressure is generated inside the box to discharge excess gas. A gas mixing unit (3) is provided inside the box (1) for mixing the gas inside the box (1); The detection module is located on the top and / or side wall of the enclosure (1) and is used to detect environmental parameters such as temperature and humidity, atmospheric pressure and methane concentration inside the enclosure (1) and the position information of the enclosure (1) in real time. Power supply unit (8) is used to supply power to the static box device; The control system, electrically connected to the gas delivery unit (2), the gas mixing unit (3), and the detection module, is configured as follows: Start the gas delivery unit (2) to perform operation (a) until the methane concentration is below a predetermined threshold; The gas mixing unit (3) is activated periodically, and environmental parameters and location information are collected using the detection module; The collected environmental parameters and location information are transmitted to a remote server or cloud platform; The gas delivery unit (2) is controlled to perform operation (b) to sample the gas inside the housing (1); The lower outer side of the box (1) is provided with a flexible sealing skirt (9). The flexible sealing skirt (9) includes a flexible body (91) that surrounds and is fixed to the lower outer side of the box (1). The side surface of the flexible body (91) that contacts the ground surface is constructed with at least one of the following structures: a smooth surface for enhancing the adhesion to a flat ground surface; or a textured or wrinkled surface for enhancing the interlocking ability with an irregular ground surface. The box body (1) is provided with an auxiliary anchoring structure (10). The auxiliary anchoring structure (10) includes multiple mooring rings (101) located on the upper part of the box body (1), multiple ground anchors (102) that can be driven into the ground around the box body (1), multiple steel wire ropes (103) corresponding to the mooring rings (101) and the ground anchors (102), and a tensioner (104) located on the steel wire ropes (103) for tightening the steel wire ropes (103).

2. The landfill methane long-term monitoring static box device according to claim 1, characterized in that: The gas delivery unit (2) includes a miniature air pump (21) with multiple interfaces. The first interface of the miniature air pump (21) is connected to the atmosphere, the second interface is connected to the interior of the housing (1), and the third interface is connected to the gas collection device (22). The miniature air pump (21) is configured to perform the following: draw fresh air from the atmosphere through the first interface and pump it into the interior of the housing (1) through the second interface, or draw gas from the interior of the housing (1) to the gas collection device (22) through the second interface.

3. The landfill methane long-term monitoring static box device according to claim 2, characterized in that: The connection path between the third interface and the gas collection device (22) is equipped with a one-way valve and a filter.

4. The landfill methane long-term monitoring static box device according to claim 1, characterized in that: The gas mixing unit (3) includes a horizontal support rod (31) and a mixing fan (32). One end of the horizontal support rod (31) is connected to the inner wall of the housing (1), and the other end is connected to the mixing fan (32). The mixing fan (32) is located in the center of the housing (1).

5. The landfill methane long-term monitoring static box device according to claim 1, characterized in that: The detection module includes a thermometer and hygrometer (4), a pump-type methane detector (5), a GPS recorder (6), and a barometer (7) integrated on the top and / or side wall of the housing (1).

6. The landfill methane long-term monitoring static box device according to claim 1, characterized in that: The power supply unit (8) includes a solar panel and an energy storage battery, which are used to supply power to the electrical equipment of the static box device.

7. A method for long-term monitoring of methane in landfills, employing the static chamber device as described in any one of claims 1-6, characterized in that, Includes the following steps: During the deployment phase, the wedge-shaped edge at the bottom of the container (1) is embedded into the ground surface and sealed by a flexible sealing skirt (9); During the initialization phase, the gas delivery unit (2) injects outside air into the box until the methane concentration is lower than the predetermined threshold. During the injection process, the one-way low-pressure relief valve (12) automatically opens to discharge excess gas from the box. During the monitoring phase, the following operations will be performed periodically: The gas mixing unit (3) is started at a preset time interval to mix the gas. During the mixing process, the one-way low-pressure relief valve (12) is automatically opened to discharge the excess gas in the box. After mixing, the detection module collects data on methane concentration, temperature and humidity, atmospheric pressure and location. The collected data is transmitted to a remote server or cloud platform; The sampling procedure involves extracting gas from the box as needed and storing it in a gas collection device (22).

8. The method for long-term methane monitoring in landfills according to claim 7, characterized in that, The formula for calculating the methane emission rate Q from landfills is as follows: Where: Q is the methane emission rate, in g / (m³). 2 ·min); P a This is the absolute atmospheric pressure during the testing period, in Pa. The value is the molar mass of methane, 16 g / mol; V is the static tank volume, in m³. 3 A is the static box area, in meters. 2 R is the gas constant, 8.314 J / (K·mol); T is the temperature during the test, in K. This is the concentration gradient of CH4 within the static chamber, in minutes. -1 .

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