Multi-point concentration detection system for hydrogen phosphide gas in grain pile

Abstract

This invention relates to the field of green grain storage technology and discloses a multi-point concentration detection system for phosphine gas in grain piles. Addressing the shortcomings of existing detection equipment, such as limited detection points, limited functionality, and lack of intelligence, this invention proposes an intelligent control scheme that expands the monitoring points for phosphine gas in grain piles and integrates real-time data detection and analysis algorithms. By monitoring the concentration of phosphine gas in real time, the system provides a comprehensive and timely understanding of the fumigation concentration distribution in the grain pile and the safe concentration threshold for phosphine gas in the grain silo. The detection process is fully automated, eliminating the need for manual intervention and improving safety. The system includes a digital display of detected concentrations, voice announcement of safety thresholds, and linkage with access control. A phosphine gas cloud map display is also included, facilitating basic research on grain storage.

Description

Technical Field

[0001] This invention relates to the field of green grain storage technology, specifically a multi-point concentration detection system for phosphine gas in grain piles. Background Technology

[0002] During grain storage, phosphine fumigation is commonly used to control stored grain pests. The uniformity of phosphine gas concentration distribution within the grain pile and whether it reaches the effective insecticidal concentration threshold directly affect the fumigation effect and grain safety. Therefore, multi-point, real-time, and precise monitoring of phosphine gas concentration within the grain pile is a crucial aspect of green grain storage technology.

[0003] The existing phosphine gas detection technology in grain depots has the following shortcomings: Firstly, traditional equipment uses mobile sampling, and single-point detection cannot reflect the dynamic changes in the field, lacking information on the overall distribution of phosphine gas concentration in the grain pile after fumigation. Secondly, the separation of the phosphine gas sampling device from the actuator leads to data transmission delays and control lags. It lacks intelligent control functions, has limited functionality, and lacks remote monitoring and data analysis capabilities. Manual detection is time-consuming and labor-intensive, and there is a possibility of forgetting. Furthermore, current detection equipment requires extracting phosphine, which may involve contact with personnel, posing a safety hazard. Moreover, the relevant data requires human analysis and judgment, which is not intelligent enough and cannot meet the management needs of intelligent grain depots. Summary of the Invention

[0004] The purpose of this invention is to provide a multi-point concentration detection system for phosphine gas in grain piles, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a multi-point concentration detection system for phosphine gas in grain piles, comprising: Multiple gas collection tubes are used to insert into different depths and areas of the grain pile. Each collection tube has micro-holes formed by laser drilling on its wall. The sensor group includes a phosphine gas sensor, a temperature sensor, and a humidity sensor that are connected to each acquisition tube. A negative pressure air pump, connected to each collection pipe via pipeline, is used to extract gas from the grain pile; Multiple solenoid valves are respectively installed on the connecting pipes between each collection tube and the negative pressure air pump; The main control module is electrically connected to the sensor group, the negative pressure air pump and the solenoid valve respectively. The main control module has a built-in data analysis algorithm, which is used to generate a phosphine concentration distribution cloud map based on multi-point real-time concentration data, and output a control signal after comparing it with a preset safety threshold.

[0006] Preferably, the gas collection tube is a nylon tube, and multiple gas collection tubes are grouped together. Each collection tube is used to collect gas at different depths. Each group of collection tubes is covered with a polyvinyl chloride outer sheath and has an internal steel wire support structure. The pore size of the micropore is set to be able to shield grain particles while allowing gas to pass through.

[0007] Preferably, it also includes a liquid crystal display module, wherein the main control module sends the real-time detected phosphine gas concentration value and the safety threshold comparison result to the liquid crystal display module for digital display.

[0008] Preferably, it also includes a voice broadcast module, which drives the main control module to issue a voice warning when it detects that the concentration of phosphine gas exceeds a safety threshold.

[0009] Preferably, it also includes an access control linkage module, wherein the main control module outputs an access control lock signal when it detects that the concentration of phosphine gas exceeds a safety threshold, and outputs an access control unlock signal when the concentration drops below the safety threshold.

[0010] Preferably, the main control module includes a low-power ARM processor and integrates a Wi-Fi communication module and / or a Bluetooth communication module; the system also includes a cloud data platform, through which the main control module uploads multi-point concentration data, temperature and humidity data and concentration distribution cloud map to the cloud data platform via the communication module.

[0011] Preferably, the cloud data platform is equipped with a lightweight AI model. This model is trained based on historically collected multi-point concentration data and corresponding application rate data to generate an optimized allocation strategy for aluminum phosphide application rate, which is then fed back to the main control module.

[0012] Preferably, the data analysis algorithm built into the main control module includes the following functions: Spatial interpolation of multi-point phosphine gas concentration data is performed to generate a cloud map of the concentration distribution inside the grain pile. Based on the concentration distribution cloud map, identify areas where the concentration is below the effective threshold and indicate the location for medication replenishment; Record the changes in concentration over time to generate dynamic demonstration data of gas dispersion or diffusion processes.

[0013] Preferably, the negative pressure air pump supports stepless power adjustment from 0 to 100%, and the main control module uses a PID control algorithm to dynamically adjust the duty cycle of the negative pressure air pump according to the deviation between the set flow rate value and the actual sampled flow rate value, so that the gas sampling flow rate of each collection tube remains consistent.

[0014] Preferably, it also includes a power supply module, which supports a wide voltage input of AC 90-264V and has built-in overvoltage protection circuit and overcurrent protection circuit.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention reduces manual operation by dynamically and in real-time detecting the concentration of phosphine gas in grain piles, and reflects the dynamic distribution of phosphine gas in grain piles in real time, which is beneficial to basic research on grain storage. This invention reduces carbon emissions, reduces phosphine gas exposure, improves safety, and helps achieve the "dual carbon" goal. In addition, this invention supports multi-scenario adaptation, is easy to install, has a high cost performance, and is highly applicable in the industry. Attached Figure Description

[0016] Figure 1 A schematic diagram of the gas sampling device structure of the multi-point concentration detection system for phosphine gas in grain piles provided by the present invention; Figure 2 This is a framework diagram of the multi-point concentration detection system for phosphine gas in grain piles provided by the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1 Please see Figure 1 - Figure 2 As shown, the multi-point concentration detection system for phosphine gas in grain piles includes: Multiple gas collection tubes are used to insert into different depths and areas of the grain pile. Each collection tube has micro-holes formed by laser drilling on its wall. The sensor group includes a phosphine gas sensor, a temperature sensor, and a humidity sensor that are connected to each acquisition tube. A negative pressure air pump, connected to each collection pipe via pipeline, is used to extract gas from the grain pile; Multiple solenoid valves are respectively installed on the connecting pipes between each collection tube and the negative pressure air pump; The main control module is electrically connected to the sensor group, the negative pressure air pump and the solenoid valve respectively. The main control module has a built-in data analysis algorithm to generate a phosphine concentration distribution cloud map based on real-time concentration data from multiple points, and outputs a control signal after comparing it with a preset safety threshold.

[0019] The gas collection tube is a nylon tube covered with a polyvinyl chloride outer sheath and has an internal steel wire support structure; the pore size of the micropores is set to be able to shield grain particles while allowing gas to pass through.

[0020] Based on the above embodiments, a liquid crystal display module is also included. The main control module sends the real-time detected phosphine gas concentration value and the comparison result of the safety threshold to the liquid crystal display module for digital display.

[0021] It also includes a voice broadcast module. When the main control module detects that the concentration of phosphine gas exceeds the safety threshold, it drives the voice broadcast module to issue a voice warning.

[0022] It also includes an access control linkage module. When the main control module detects that the concentration of phosphine gas exceeds the safety threshold, it outputs an access control lock signal, and when the concentration drops below the safety threshold, it outputs an access control unlock signal.

[0023] The main control module includes a low-power ARM processor and integrates a Wi-Fi communication module and / or a Bluetooth communication module; the system also includes a cloud data platform, through which the main control module uploads multi-point concentration data, temperature and humidity data and concentration distribution cloud map to the cloud data platform via the communication module.

[0024] The cloud data platform is equipped with a lightweight AI model. Based on historically collected multi-point concentration data and corresponding application rate data, the model is trained to generate an optimized allocation strategy for aluminum phosphide application rate and feeds it back to the main control module.

[0025] The data analysis algorithms built into the main control module include the following functions: Spatial interpolation of multi-point phosphine gas concentration data is performed to generate a cloud map of the concentration distribution inside the grain pile. Based on the concentration distribution cloud map, identify areas where the concentration is below the effective threshold and indicate the location for medication replenishment; Record the changes in concentration over time to generate dynamic demonstration data of gas dispersion or diffusion processes.

[0026] The negative pressure air pump supports stepless power adjustment from 0 to 100%. The main control module uses a PID control algorithm to dynamically adjust the duty cycle of the negative pressure air pump according to the deviation between the set flow rate value and the actual sampled flow rate value, so that the gas sampling flow rate of each collection tube remains consistent.

[0027] It also includes a power module that supports a wide voltage input of AC 90-264V and has built-in overvoltage protection and overcurrent protection circuits.

[0028] Example 2 The gas collection tube can be made of nylon tubing with an inner diameter of 6mm and an outer diameter of 8mm, covered with a polyvinyl chloride (PVC) outer sheath, and internally supported by 304 stainless steel wire. The collection tube is inserted into the grain pile to a predetermined depth. The tube wall of the inserted section is laser-drilled to form micropores with a diameter of 0.2mm. The micropores are spaced 10mm apart and distributed in 4 rows around the circumference. These micropores allow phosphine gas to pass through while blocking grain particles with a diameter greater than 0.5mm from entering the tube.

[0029] The sensor array includes multiple phosphine gas sensors (model: PH3-B1, range 0-2000ppm), a platinum resistance temperature sensor (Pt100), and a capacitive humidity sensor (HM1500). Each acquisition tube corresponds to a set of sensors, which are installed in a sealed gas chamber outside the grain silo.

[0030] The negative pressure air pump adopts a diaphragm vacuum pump with an adjustable flow rate of 0-5L / min. The power can be steplessly adjusted from 0 to 100% through the PWM signal output by the main control module.

[0031] A two-position normally closed solenoid valve (DC24V, response time <50ms) is installed on the pipeline between each sampling tube and the negative pressure air pump in the solenoid valve assembly. The air inlets of all solenoid valves are connected to each sampling tube respectively, and the air outlets are connected in parallel to the air inlet main of the negative pressure air pump.

[0032] The main control module is based on an ARM Cortex-M4 processor (STM32F407), with a built-in real-time operating system, and integrates a Wi-Fi module (ESP8266) and a Bluetooth module (CC2541). The main control module acquires sensor signals through an analog input interface, controls the on / off state of the solenoid valve through I / O ports, and adjusts the power of the air pump through PWM output.

[0033] The human-machine interaction module includes a 4.3-inch TFT LCD touch screen (displaying real-time concentration, cloud map and alarm information) and a voice broadcast speaker (stores preset concentration threshold alarm voices).

[0034] The access control linkage module consists of a relay output module, whose normally open contacts are connected in series to the power circuit of the grain warehouse entrance access control.

[0035] The power module uses a switching power supply with an input of AC 90-264V and outputs of DC24V / 5A and DC5V / 2A. It has built-in overvoltage, overcurrent, and short-circuit protection circuits.

[0036] The cloud-based data platform is deployed on Alibaba Cloud ECS servers, running data receiving service programs and a web front-end.

[0037] Workflow: After the main control module powers on, it self-checks the status of each sensor, air pump, and solenoid valve. It then connects to the warehouse LAN via Wi-Fi and establishes an MQTT connection with the cloud platform. The LCD screen displays the standby interface. The main control module sequentially opens the first solenoid valve according to the preset polling order, and simultaneously starts the negative pressure air pump to pump air at a constant flow rate of 2L / min (using a PID algorithm to maintain stable flow, see the following description). The gas enters the pipeline through the micro-holes of the sampling tube, flows through the phosphine gas sensor and the temperature and humidity sensor, and the detection data is updated every 2 seconds. After sampling for 30 seconds, the solenoid valve of that point is closed, and the concentration, temperature, humidity, and timestamp of that point are saved. Then, the next solenoid valve is opened until all points have been detected. One sampling cycle can be set to 10-30 minutes depending on the volume of the grain pile and the number of points.

[0038] The main control module reads the flow rate from the miniature flow sensor installed at the air pump outlet in real time (not in...). Figure 1 As shown in the diagram, the feedback value is connected in series with the pipeline during actual implementation. The target flow rate is set to 2L / min. The deviation signal is input to the digital PID controller, and the output value is converted into a PWM duty cycle of 0-100% to adjust the air pump speed, ensuring that the air flow rate is not affected by pipeline blockage or air source fluctuations.

[0039] The main control module spatially interpolates the three-dimensional coordinates of each detection point (the insertion depth and planar coordinates pre-entered in the system) with the corresponding phosphine concentration value (using the inverse distance weighting method with a search radius of 2m) to generate a continuous color-filled cloud map, which is then displayed on the LCD screen in real time. Simultaneously, the cloud map data and the concentration-time curve are packaged into JSON format and uploaded to the cloud platform via Wi-Fi.

[0040] The main control module compares the concentration at each location with a preset alarm threshold (e.g., a safety threshold of 0.3 ppm and an alarm threshold of 100 ppm). If the concentration at any location exceeds the alarm threshold, the main control module drives the voice broadcast module to repeatedly broadcast "Phosphine concentration exceeds limit, danger, do not enter"; simultaneously, it cuts off the access control power supply via a relay, causing the electric lock to drop and preventing personnel from entering; the alarm area on the LCD screen flashes red. When the concentration at all locations drops below the safety threshold, the access control power supply is automatically restored and the voice alarm stops.

[0041] All detection data, cloud image snapshots, and alarm events are sent to the cloud platform in real time via the MQTT protocol. The platform provides a web interface, allowing administrators to remotely view the current concentration distribution, historical trend charts, and export reports.

[0042] Example 3 Based on Examples 1 and 2, this embodiment further introduces a lightweight AI model to assist in the optimized allocation of aluminum phosphide application rate, thereby achieving precise fumigation.

[0043] The cloud platform has added a machine learning module based on Python. The training dataset consists of multi-point concentration sequence data collected during 10 fumigation operations in the past two years at the grain depot, as well as the corresponding application amount in each area (the weight of aluminum phosphide tablets at each application point was recorded by electronic scales).

[0044] The main control module program has been upgraded to include a "drug application suggestion" function, which displays the areas requiring additional drug application and the estimated dosage on the LCD screen.

[0045] Workflow: (1) Data accumulation: During each fumigation operation, the system completes a full-point detection every 2 hours, and the data is automatically uploaded to the cloud and stored in conjunction with the amount of pesticide applied in each area.

[0046] (2) Model training: The cloud platform uses the random forest regression algorithm, with the initial concentration at each detection point, the concentration increase rate 24 hours after application, the amount of pesticide applied near the point, and the temperature and humidity of the grain pile as input features, to train the model to predict the minimum amount of pesticide required to achieve an effective concentration (e.g., 200 ppm). Model training is performed automatically once a week, and the model parameters are updated using new data.

[0047] (3) Application Decision: Before a new fumigation operation, the system automatically generates a target concentration cloud map based on the grain pile volume and expected pest resistance (e.g., requiring a concentration of ≥200ppm at any point in the entire grain pile and maintaining it for 10 days). The cloud-based AI model calculates the recommended application amount for the upper, middle, and lower layers of the grain pile, as well as the edge and central areas, based on the temperature and humidity distribution of the grain pile and the application effects under similar conditions in the past, and pushes this information to the main control module. Operators can view the "Application Plan Map" on the LCD screen (different areas are marked with different colors and g / m³). 3 (Recommended value), apply the medicine as shown in the diagram.

[0048] (4) Dynamic correction during fumigation: After fumigation begins, the system continuously monitors the concentration. If the concentration in a certain area rises slowly or falls below the target value, the main control module automatically issues a "replenishment prompt" and provides a suggested amount of replenishment (based on real-time reasoning from the AI ​​model). Staff add the agent through the pre-embedded replenishment tubes until the concentration in all areas reaches the target.

[0049] (5) Effect evaluation: After the fumigation is completed, the system automatically generates indicators such as the concentration compliance rate, the proportion of low concentration areas, and the total amount of fumigation, and compares them with historical operations to form an optimization report to help the custodian improve the next plan.

[0050] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-point concentration detection system for phosphine gas in grain piles, characterized in that, include: Multiple gas collection tubes are used to insert into different depths and areas of the grain pile. Each collection tube has micro-holes formed by laser drilling on its wall. Each grain silo is equipped with multiple sets of gas collection pipes, forming a matrix of collection points arranged in the upper, middle and lower spaces inside the grain pile; Each sampling tube was selected separately to sample the gas at different locations in the grain pile. The sensor array includes a phosphine gas sensor, a temperature sensor, and a humidity sensor connected to the gated acquisition tube. A negative pressure air pump, connected to each collection pipe via pipeline, is used to extract gas from the grain pile; Multiple solenoid valves are respectively installed on the connecting pipes between each collection tube and the negative pressure air pump; The main control module is electrically connected to the sensor group, the negative pressure air pump and the solenoid valve respectively. The main control module has a built-in data analysis algorithm, which is used to generate a phosphine concentration distribution cloud map based on multi-point real-time concentration data, and output a control signal after comparing it with a preset safety threshold.

2. The multi-point concentration detection system for phosphine gas in grain piles according to claim 1, characterized in that: The gas collection tube is a nylon tube, and several collection tubes are grouped together. Each group of collection tubes is covered with a polyvinyl chloride outer sheath and has an internal steel wire support structure. The pore size of the micropores is set to be able to shield grain particles while allowing gas to pass through.

3. The multi-point concentration detection system for phosphine gas in grain piles according to claim 1, characterized in that: It also includes a liquid crystal display module, and the main control module sends the real-time detected phosphine gas concentration value and the comparison result of the safety threshold to the liquid crystal display module for digital display.

4. The multi-point concentration detection system for phosphine gas in grain piles according to claim 1, characterized in that: It also includes a voice broadcast module, which drives the main control module to issue a voice warning when it detects that the concentration of phosphine gas exceeds the safety threshold.

5. The multi-point concentration detection system for phosphine gas in grain piles according to claim 1, characterized in that: It also includes an access control linkage module, in which the main control module outputs an access control lock signal when it detects that the concentration of phosphine gas exceeds a safety threshold, and outputs an access control unlock signal when the concentration drops below the safety threshold.

6. The multi-point concentration detection system for phosphine gas in grain piles according to claim 1, characterized in that: The main control module includes a low-power ARM processor and integrates a Wi-Fi communication module and / or a Bluetooth communication module; the system also includes a cloud data platform, through which the main control module uploads multi-point concentration data, temperature and humidity data and concentration distribution cloud map to the cloud data platform via the communication module.

7. The multi-point concentration detection system for phosphine gas in grain piles according to claim 6, characterized in that: The cloud data platform is equipped with a lightweight AI model. Based on historically collected multi-point concentration data and corresponding application rate data, the model is trained to generate an optimized allocation strategy for aluminum phosphide application rate and feeds it back to the main control module.

8. The multi-point concentration detection system for phosphine gas in grain piles according to claim 1, characterized in that: The data analysis algorithm built into the main control module includes the following functions: Spatial interpolation of multi-point phosphine gas concentration data is performed to generate a cloud map of the concentration distribution inside the grain pile. Based on the concentration distribution cloud map, identify areas where the concentration is below the effective threshold and indicate the location for medication replenishment; Record the changes in fumigation concentration over time, and dynamically display the generation, dispersion, or diffusion of phosphine gas.

9. The multi-point concentration detection system for phosphine gas in grain piles according to claim 1, characterized in that: The negative pressure air pump supports stepless power adjustment from 0-100%. The main control module uses a PID control algorithm to dynamically adjust the duty cycle of the negative pressure air pump according to the deviation between the set flow rate value and the actual sampled flow rate value, so that the gas sampling flow rate of each collection tube remains consistent.

10. The multi-point concentration detection system for phosphine gas in grain piles according to claim 1, characterized in that: It also includes a power module that supports a wide voltage input of AC 90-264V and has built-in overvoltage protection circuit and overcurrent protection circuit.

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