Dynamic closed-loop dual-channel air plasma efficient ammonia capture intelligent regulation and control system

Abstract

The invention belongs to the field of ammonia recovery, and discloses a dynamic closed-loop dual-channel air plasma efficient ammonia capture intelligent regulation and control system, which mainly comprises a plasma discharge unit, an NH3 input unit, a mixed reaction chamber, a gas product detection module and an intelligent regulation and control system, all the units form an integral working system with interconnected functions through a gas circuit, a signal line and a control circuit. According to the invention, a continuous operation mode of discharging, trapping, reacting and regulating at the same time is realized through a modular design and a dual-channel collaborative reaction architecture, the resource utilization efficiency is improved, the complexity and the operation cost of a traditional ammonia treatment system are remarkably reduced, and the system has good engineering adaptability and popularization prospects.

Description

Technical Field

[0001] This invention belongs to, but is not limited to, the field of ammonia recovery technology, and particularly relates to a dynamic closed-loop dual-channel air plasma high-efficiency ammonia capture and intelligent control system. Background Technology

[0002] Nitrogen, a core component of proteins and nucleic acids in living organisms, plays a fundamental role in the ecosystem through its cycle. Nitrogen cycle imbalance has become a global environmental challenge. Globally, agricultural activities result in a loss of up to 100 Tg of nitrogen annually, with over 80% of nitrogen lost through NH3 volatilization during livestock manure treatment. Such emissions not only reduce nitrogen fertilizer utilization but also exacerbate smog by generating secondary particulate matter and contribute to soil acidification and eutrophication. In China, nitrogen fertilizer utilization is only 30%-35%, with over 45% of nitrogen lost through NH3 volatilization, equivalent to a loss of hundreds of billions of yuan worth of fertilizer resources annually.

[0003] Current mainstream NH3 treatment technologies have fundamental limitations: physicochemical methods primarily rely on porous materials (such as activated carbon and zeolite molecular sieves) for the physical adsorption of NH3. While this technology can rapidly enrich low-concentration NH3, the adsorbent requires high-temperature thermal desorption regeneration after saturation. Energy consumption during this process is concentrated in the sensible heat of the adsorbent's temperature rise and the latent heat of NH3 desorption, resulting in secondary energy waste. More seriously, when the NH3 concentration in the waste gas exceeds 500 ppm, the microporous structure of the adsorbent may permanently collapse due to excessive accumulation of NH3 molecules, leading to irreversible degradation of adsorption capacity. Biodegradation methods utilize nitrifying-denitrifying bacteria to convert NH3 into nitrogen, but the metabolic rate of these microorganisms is strictly controlled by environmental parameters: temperature fluctuations of ±5℃ can inhibit enzyme activity, pH deviations from the 6-8 range lead to bacterial inactivation, and sudden increases in NH3 concentration can directly poison nitrifying bacteria. The system requires large aeration tanks and precise temperature control equipment to maintain bacterial activity, resulting in a reaction lag of over 6 hours, making it difficult to cope with the instantaneous fluctuations in agricultural and livestock waste gas. Another core flaw of these two technologies is that they convert high-value nitrogen resources into nitrogen gas or waste adsorbents with no economic value, which deviates from the concept of resource recycling.

[0004] Plasma technology, with its ability to generate highly reactive particles through non-equilibrium discharge, offers a new pathway to overcome the aforementioned limitations. Recent research has primarily focused on the efficient decomposition or conversion of NH3 into H2, but energy economy and application scenarios remain insufficient. Direct decomposition of NH3 consumes a large amount of electrical energy, and the H2 generated in agricultural and pastoral settings lacks practical value. Currently, the applicant's team has innovatively proposed a synergistic route combining plasma nitrogen fixation and NH3 recovery, which effectively synthesizes high-value nitrogen fertilizer NH4NO3 while reducing NH3 volatilization. However, its engineering application still faces three major obstacles:

[0005] First, there is a lack of optimization in the energy efficiency of the reaction pathway. The existing scheme adopts a single-channel reaction mode, that is, NH3 is injected into the reaction chamber after the plasma discharge is completed. Although this mode has been verified to be feasible under laboratory conditions, in actual low-concentration, high-flow-rate waste gas environments, the utilization rate of active particles is low due to uneven gas mixing and insufficient residence time.

[0006] Secondly, dynamic control is impossible. Agricultural and livestock waste gas concentrations exhibit significant spatiotemporal fluctuations, while existing devices lack real-time sensing and feedback capabilities. They cannot dynamically adjust plasma discharge intensity based on NH3 flux to control NO. x The system's efficiency drops sharply under complex operating conditions because it cannot optimize reaction conditions by monitoring concentrations.

[0007] Third, achieving multi-parameter synergistic objectives is difficult. The synthesis efficiency of NH4NO3 is simultaneously affected by NH3 capture rate and NO... x Conversion rate and particulate matter generation are among the many variables at play, and these parameters often conflict with each other within the current technological framework. For example, while increasing discharge power can increase NO... x While increasing production capacity is possible, excessive energy input reduces the system's energy efficiency ratio; extending gas residence time promotes complete reaction but sacrifices throughput. The lack of a collaborative optimization mechanism for core parameters makes it difficult to achieve both "efficient nitrogen fixation" and "resource recovery."

[0008] The aforementioned shortcomings collectively restrict the large-scale application of plasma ammonia recovery technology, necessitating the development of novel solutions with dynamic sensing, closed-loop control, and multi-objective optimization capabilities.

[0009] Based on the above analysis, the urgent technical problems that need to be solved in the existing technology are:

[0010] Existing ammonia recovery technologies suffer from core defects such as resource waste, low energy efficiency, and insufficient dynamic adaptability. Summary of the Invention

[0011] To address the problems existing in the prior art, this invention provides a dynamic closed-loop dual-channel air plasma high-efficiency ammonia capture and intelligent control system.

[0012] This invention is implemented as follows: a dynamic closed-loop dual-channel air plasma high-efficiency ammonia capture intelligent control system, characterized in that the system mainly includes a plasma discharge unit, an NH3 input unit, a mixing reaction chamber, a gas product detection module, and an intelligent control system. The units are interconnected as a whole working system through gas paths, signal lines, and control circuits.

[0013] Furthermore, the system adopts a dual-channel parallel reaction structure: the first channel is an air channel, where air is driven by a gas pump to enter the plasma discharge unit and generate active gas under the action of a high-voltage electric field; the second channel is an NH3 channel, where on-site NH3 is delivered into the system by an independently adjustable flow rate gas pump; the two gases are introduced into the mixing reaction chamber through their respective gas paths, and are mixed at a certain angle inside the chamber, undergoing a rapid gas phase reaction at room temperature and pressure to generate aerosol products mainly composed of NH4NO3, thereby realizing the simultaneous capture and resource conversion of ammonia.

[0014] Furthermore, the plasma discharge unit can adopt a needle-needle, needle-plate, or dielectric barrier discharge structure to form a stable and efficient discharge space, which can be powered by renewable energy sources such as solar and wind power. The NH3 channel can achieve the regulation of gas concentration and flow rate through a matching flow regulation component to ensure that the reaction ratio with the plasma channel is appropriate.

[0015] Furthermore, the mixing reaction chamber is located at the confluence of the two gas channels, and its internal structure matches the dimensions of the gas path. Multiple sensors, such as NH3, main discharge products (NO, NO2, O3, etc.) and particulate matter concentration (NH4NO3 production) sensors, are installed inside or at the outlet of the reaction chamber to collect data, forming a complete gas product detection module. The sensors transmit real-time detection data to the main control system via signal lines.

[0016] Furthermore, the control system is based on embedded processing systems such as microcontrollers, FPGAs, and Raspberry Pis, forming a feedback control platform that integrates signal processing, control calculations, and drive output. The embedded processing system receives concentration data collected by multiple sensors, executes control algorithms such as proportional-integral-derivative (PID) control, incremental control, fuzzy control, or other control algorithms suitable for real-time adjustment, and outputs pulse width modulation (PWM) control signals with adjustable duty cycles. The drive module then adjusts the gas pump flow rate or discharge intensity (discharge power) of each channel, thereby dynamically controlling the gas input rate and reaction intensity, and realizing the linkage adjustment and optimization of reaction conditions.

[0017] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0018] First, this invention creatively integrates the synergistic pathway of plasma nitrogen fixation and ammonia recovery, utilizing the highly active gaseous products generated by air discharge and volatile NH3 to directionally synthesize high-value-added nitrogen fertilizer. This transforms NH3, which is treated as a pollutant in traditional technologies, into a recyclable agricultural resource, fundamentally reversing the "only removal, no harvest" governance model and achieving a dual value enhancement of pollution control and resource regeneration.

[0019] This invention adopts a dual-channel parallel reaction architecture, which delivers discharge gas and ammonia-containing waste gas separately through physically isolated dedicated gas paths, broadening the system's versatility in high-flow, low-concentration application scenarios. This allows the NH3 capture rate and discharge product utilization rate to be improved simultaneously over a wide concentration range, overcoming the energy efficiency degradation problem caused by reactant imbalance in the traditional mode. At the same time, the original sequential working process is improved into a parallel working process, thereby improving the system's working efficiency.

[0020] This invention constructs an intelligent control system based on real-time sensing and closed-loop control. By dynamically tracking changes in the concentration of key gases, it can quickly adjust the discharge intensity and gas flow rate when the NH3 concentration fluctuates, thereby achieving multi-parameter optimization and ensuring that the system maintains efficient and stable operation under complex working conditions.

[0021] This invention not only significantly reduces the need for manual intervention, but also enhances deployment flexibility through miniaturized and modular structural innovations. Combined with green energy compatibility, it provides an economically feasible nitrogen cycle optimization solution for decentralized farms and ranches.

[0022] Secondly, this invention offers significant economic and environmental benefits in high-ammonia emission scenarios in agriculture and animal husbandry. By directly converting waste ammonia into high-value-added NH4NO3 nitrogen fertilizer, a closed-loop utilization of pollution control and resource recovery is achieved. Furthermore, based on dynamic control of NH3 volatilization in agriculture and animal husbandry, ammonia volatilization loss is reduced by over 90%. Calculated based on the average annual ammonia emissions from livestock and poultry farming in China, this can save and recover over one million yuan worth of nitrogen fertilizer resources annually. Simultaneously, the energy required for system operation can be provided by renewable energy sources such as solar and wind power, resulting in low operating costs, suitability for distributed deployment, and feasibility for large-scale industrialization and investment return potential.

[0023] Currently, there is no integrated plasma ammonia capture system, either domestically or internationally, that combines real-time sensing, closed-loop control, and resource utilization for dynamic ammonia emissions from agriculture and animal husbandry. This invention proposes for the first time an architecture of "dual-channel parallel operation + dynamic closed-loop control + multi-parameter collaborative optimization," organically integrating plasma nitrogen fixation with waste ammonia recovery. This not only achieves efficient ammonia capture but also simultaneously optimizes NO during the reaction process. x The utilization rate and nitrogen fertilizer yield fill the gap in the existing technology in terms of dynamic adaptability and synergistic optimization capabilities.

[0024] For a long time, the ammonia recovery field has faced a bottleneck where "efficient capture" and "economic resource recovery" are difficult to achieve simultaneously—traditional physical adsorption and biodegradation methods are either energy-intensive and short-lived, or slow to respond and inefficient. This invention shortens the reaction time delay through a dual-channel structure and achieves millisecond-level control using real-time concentration feedback, enabling both NH3 capture rate and NO2 utilization rate to reach over 95%. For the first time, it achieves a balance between capture efficiency, reaction rate, and energy efficiency ratio under dynamic, highly fluctuating operating conditions, fundamentally breaking through the core technological barriers to the engineering application of ammonia recovery.

[0025] The current industry generally believes that plasma ammonia treatment can only serve as an end-of-pipe decomposition or auxiliary step, unable to achieve stable and efficient conversion in dynamic scenarios, let alone achieve resource utilization. This invention, through modular dual-channel design and closed-loop intelligent control, overturns the conventional wisdom that "plasma can only degrade pollutants and cannot economically produce useful products." It not only achieves stable operation in complex agricultural and livestock conditions but also proves that plasma technology can build a new bridge for resource recycling between environmental governance and agricultural production. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the dynamic closed-loop dual-channel air plasma high-efficiency ammonia capture intelligent control system provided in this embodiment of the invention;

[0027] Figure 2 This is a flowchart of the dynamic closed-loop dual-channel air plasma high-efficiency ammonia capture intelligent control system provided in this embodiment of the invention;

[0028] Figure 3 This is a schematic diagram of the experimental apparatus provided in an embodiment of the present invention;

[0029] Figure 4 This is a program control flowchart provided in an embodiment of the present invention;

[0030] Figure 5 These are real-time curves of NH3, NO2, particulate matter concentration, and PWM duty cycle provided in this embodiment of the invention. Figure 6 This is a schematic diagram showing the dynamic response process of NH3 concentration, NO2 concentration and particulate matter concentration and the change of PWM duty cycle of the system provided in this embodiment of the invention under two different flow rate conditions in the NH3 gas path after PI control. Figure 7 This is a physical image of the miniaturized control platform provided in an embodiment of the present invention. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0032] like Figure 1 As shown, this embodiment of the invention provides a dynamic closed-loop dual-channel air plasma high-efficiency ammonia capture and intelligent control system, aiming to achieve integrated treatment of efficient reduction and resource utilization of NH3 pollutants. The system mainly includes a plasma discharge unit, an NH3 input unit, a mixing reaction chamber, a gaseous product detection module, and an intelligent control system. The various units are interconnected through gas paths, signal lines, and control circuits to form a functionally interconnected overall working system.

[0033] The present invention provides a flowchart of a dynamic closed-loop dual-channel air plasma high-efficiency ammonia capture and intelligent control system, as shown in the figure below. Figure 2 As shown.

[0034] like Figure 3 As shown, the ammonia recovery and control device of this embodiment includes a plasma discharge channel and an ammonia-containing gas channel arranged in parallel. The discharge channel is equipped with a needle-needle electrode structure, which generates non-equilibrium plasma driven by a high-voltage power supply. The ammonia-containing gas channel is connected to a waste gas source and equipped with a flow regulation unit. Both gases are introduced into a tubular reaction chamber via a turbulent mixing device. Multiple gas sensing units are installed at the chamber outlet to monitor the concentrations of NH3, NO2, and particulate matter, respectively.

[0035] The control core uses an STM32 microcontroller as the processor, which receives sensor signals in real time and outputs drive commands through a closed-loop algorithm to dynamically adjust the gas flow rate in the discharge channel. The program control flowchart is as follows. Figure 4 As shown in the diagram. Specifically, when a high NH3 concentration is detected, it indicates an excess of NH3 and insufficient plasma products in the reaction zone, leading to incomplete reaction. In this case, the system will increase the duty cycle of the gas pump to accelerate the gas flow rate and promote NO2 generation, thereby ensuring reliable NH3 capture. Conversely, when the NO2 concentration is significantly higher than that of NH3, or even when NH3 has almost dropped to zero, it indicates that NH3 in the reactants has been almost completely captured, resulting in NO2 redundancy. In this case, the system will decrease the duty cycle of the gas pump to slow down the gas flow rate, reducing residual NO2 while extending the residence time of the gas in the reaction zone to ensure the complete reaction of residual NH3.

[0036] During device operation, the dual-channel air pump and exhaust channel are first activated to replace residual gas in the reaction system. Then, the NH3 channel air pump is started. Once the NH3 flow rate stabilizes at the set value, a high-voltage electric field is applied to generate stable plasma discharge between the needle-needle electrodes. At this time, air dissociates in the discharge zone to generate nitrogen oxides (NO2 in this embodiment), while ammonia-containing waste gas is simultaneously transported to the mixing zone via a separate channel. After thorough mixing, the two gas streams enter the reaction chamber, where NH3 and NO2 react to synthesize solid fertilizer granules. The control unit continuously compares the concentration difference between NH3 and the discharge products: when the NH3 concentration increases, the microcontroller increases the pulse width modulation (PWM) duty cycle of the plasma discharge channel air pump control module to accelerate the airflow in the discharge channel and increase the yield of active nitrogen oxides; when the NO2 concentration is too high, the duty cycle is reduced to decrease the airflow rate. The generated fertilizer granules can be applied directly or formulated into liquid fertilizer.

[0037] The mixing reaction chamber is located at the confluence of the two gas channels, and its internal structure matches the gas path dimensions to ensure sufficient residence time for the reacting gases to achieve a complete reaction. Multiple sensors, including those for NH3, major discharge products (NO, NO2, O3, etc.), and particulate matter concentration (NH4NO3 yield), are installed inside or at the outlet of the reaction chamber to acquire data, forming a complete gas product detection module. These sensors transmit real-time detection data to the main control system via signal lines.

[0038] The control system is based on embedded processing systems such as microcontrollers, FPGAs, and Raspberry Pis, forming a feedback control platform that integrates signal processing, control calculations, and drive output. The embedded processing system receives concentration data from multiple sensors, executes control algorithms such as proportional-integral-derivative (PID) control, incremental control, fuzzy control, or other control algorithms suitable for real-time adjustment, outputs pulse-width modulation (PWM) control signals with adjustable duty cycles, and adjusts the gas pump flow rate or discharge intensity (discharge power) of each channel via the drive module. This dynamically controls the gas input rate and reaction intensity, achieving coordinated adjustment and optimization of reaction conditions.

[0039] The system's control logic uses particulate matter concentration as the primary feedback variable, combined with NH3 and discharge product concentrations as auxiliary variables, to optimize reaction parameters in real time. This ensures that the NH3 capture rate, discharge product utilization rate, and NH4NO3 yield maintain a synergistically optimal state during system operation. Furthermore, the priority and relative weight of NH3 capture rate and discharge product utilization rate in the control logic's evaluation system can be adjusted according to different application scenarios, improving the system's adaptability. The generated NH4NO3 particles can be collected by a downstream aerosol capture module for nitrogen fertilizer reuse; the system's exhaust gas emissions are also kept below safe thresholds, meeting environmental emission requirements.

[0040] All power supply modules of the system can be powered by abundant renewable resources such as solar and wind power in agricultural and pastoral scenarios, which can significantly reduce operating costs and improve environmental friendliness.

[0041] This invention achieves a continuous operation mode of "discharging, capturing, reacting, and regulating simultaneously" through modular design and dual-channel synergistic reaction architecture. While improving resource utilization efficiency, it significantly reduces the complexity and operating cost of traditional ammonia treatment systems, and has good engineering adaptability and promotion prospects.

[0042] The present invention relates to a dynamic closed-loop dual-channel air plasma high-efficiency ammonia capture intelligent control system. This system introduces air and ammonia-containing waste gas through dual-channel gas input modules. The air channel generates highly active particles via a plasma discharge unit, while the ammonia channel has its flow rate precisely controlled by an adjustable flow rate pump. The two gases undergo thorough turbulent mixing and gas-phase reactions within the mixing reaction chamber, providing conditions for subsequent ammonia capture and conversion. The system design integrates pollutant reduction with ammonia resource recovery and utilization.

[0043] Within the mixing reaction chamber, plasma-active particles undergo a series of redox reactions with ammonia, generating aerosol products primarily composed of ammonium nitrate (NH4NO3), along with gaseous byproducts such as NO, NO2, and O3. Multiple sensors, including NH3, NO2, and particulate matter concentration sensors, are installed at the reaction chamber outlet to enable real-time monitoring of the composition and concentration of the reaction products, thus providing a data foundation for feedback control.

[0044] The gas product detection module is connected to the embedded intelligent control system. Data such as gas concentration and particulate matter concentration collected by the sensor are input to the processing unit through the data interface. The processing unit runs a control algorithm to dynamically calculate the concentration difference and residual amount of NH3 and NO2, and outputs control signals in real time according to preset target parameters to adjust the gas pump flow rate and plasma discharge power, thereby optimizing the reaction efficiency and capture effect.

[0045] In terms of hardware implementation, the system integrates a high-voltage power supply-driven needle-to-needle electrode discharge structure, a PWM-adjustable driven air pump flow control unit, an air path switching and filtration module, as well as an OLED display and human-machine interface. An STM32 controller manages the operating status of each module and executes a closed-loop control program to ensure the system's stability and response speed under different pollutant concentrations and operating conditions.

[0046] The control strategy employs a hierarchical closed-loop PI control algorithm. When a change in NH3 concentration is detected, the system first performs priority adjustment to ensure ammonia capture efficiency. Subsequently, the concentration difference between NH3 and NO2 is calculated, and the PWM duty cycle is automatically corrected based on the PI adjustment coefficient to achieve a balance between nitrogen oxide production and ammonia capture rate. Simultaneously, output variation amplitude limits are set to avoid overshoot or oscillation during adjustment, improving control accuracy and stability.

[0047] The system provided by this invention highly integrates gas flow control, plasma reaction, product detection and intelligent feedback regulation to form a dynamic and adaptive ammonia pollution control and resource utilization platform. It is particularly suitable for application scenarios such as ammonia emission control in agriculture and animal husbandry and ammonia recovery in livestock farms, and can be combined with renewable energy sources such as wind power and photovoltaic power to achieve green drive.

[0048] Figure 5 The FTIR values ​​at 5 min are for the experimental group (air flow rate 100 sccm, NH3 flow rate 5 sccm) and the corresponding control group in dual-channel mode. It can be observed that when both channels are operating simultaneously, compared to the case where only one channel is operating (control group), the NO concentration in the reaction chamber is significantly lower. x The significant reduction in NH3 levels, coupled with the substantial formation of NH4NO3, demonstrates the feasibility of the system operation under the dual-channel reaction architecture and its effectiveness in reducing NH3 volatilization and increasing NO3 levels. x The efficiency of utilizing and capturing NH3 to generate reusable NH4NO3.

[0049] Figure 6 The dynamic response of the system to NH3, NO2, and particulate matter concentrations under PI control under two different flow rate conditions in the NH3 gas path is demonstrated, and the changes in the PWM duty cycle are recorded simultaneously. The results show that the PI algorithm-based control strategy can achieve rapid feedback to changes in NH3 concentration and adaptive flow rate adjustment. In Figures 6(a1) and (a2), when an increase in NH3 concentration is detected, the system immediately increases the PWM duty cycle, increases the air flow rate in the discharge channel, rapidly replenishes the NO2 generation, and promotes the full reaction between NH3 and NO2, thereby achieving rapid NH3 capture. Its concentration can quickly drop to a low level (almost 0) within about 10 seconds, at which point the NH3 capture rate is close to ~100%, demonstrating good control response speed and NH3 capture effect. After the NH3 concentration decreases, the NO2 concentration is also adjusted accordingly and maintained within a reasonable range, effectively avoiding its residual accumulation.

[0050] exist Figure 6In Figures (b1) and (b2), the system exhibits more stable control capabilities. As the NH3 concentration increases, the duty cycle is rapidly adjusted to compensate for the NO2 concentration, causing the NH3 concentration to drop quickly and stabilize, at which point the NH3 capture rate approaches 100%. When the NH3 channel is replaced with pure air at the same flow rate, and the duty cycle is set at 30% in the control group, the NO2 concentration at the end of the reaction reaches as high as 618.6 ppm, while in this experimental group, the NO2 concentration is only below 15 ppm, achieving a NO2 utilization rate of over 95%. Throughout the process, both NH3 and NO2 concentrations remain at low levels, and the particulate matter concentration curve continues to rise, indicating a relatively complete reaction.

[0051] In summary, Figure 6 verifies that the control strategy combined with the PI algorithm in this system can achieve rapid response, real-time closed-loop regulation, and efficient conversion of NH3 fluctuations. Precise control of NO2 generation ensures the full capture and conversion of NH3 under dynamic disturbances, providing solid support for applications in complex agricultural and pastoral conditions.

[0052] Figure 7 The image shows a physical model of the miniaturized control platform, where the STM32 main control board, OLED display, sensor module, and air pump drive circuit are integrated on the PCB.

[0053] In areas with high ammonia emissions, such as agricultural greenhouses and livestock farms, traditional ammonia control methods generally suffer from slow response, low capture efficiency, and difficulty adapting to dynamic operating conditions, and they also fail to achieve resource utilization. Ammonia emissions not only pose a threat to human and animal health, but also combine with oxidizing gases in the environment (such as NO, NO2, and O3) to form PM2.5. 2.5 Secondary particulate matter at high levels exacerbates air pollution and restricts the sustainable development of green agriculture. Therefore, there is an urgent need for a highly efficient ammonia capture system with real-time sensing, rapid regulation, and resource conversion capabilities to connect the industrial chain of environmental control and waste ammonia resource conversion and utilization.

[0054] To address the bottlenecks of slow reaction and low efficiency in traditional systems, this invention employs a dual-channel parallel gas input structure. The first channel is an ambient air path, where air is pumped into the plasma discharge unit and excited under a high-voltage electric field to form a plasma flow rich in highly reactive gases such as NO, NO2, and O3. The second channel is a controllable NH3 delivery path, with an independent variable-speed gas pump controlling the flow rate and concentration of ammonia on-site. The two gas paths are introduced into the mixing reaction chamber through independent gas paths, where they mix at a certain angle under normal pressure and temperature conditions, rapidly undergoing a gas-phase reaction to synthesize aerosol particles mainly composed of NH4NO3, achieving simultaneous ammonia capture and resource conversion.

[0055] To accommodate operational needs across diverse scenarios, the plasma discharge unit employed in the system supports various discharge structures, including needle-needle, needle-plate, and dielectric barrier discharge (DBD). It features low start-up voltage, high reactivity, and low energy consumption, making it suitable for agricultural scenarios with high humidity and heavy dust loads. Furthermore, the system can integrate renewable energy components such as solar panels and wind turbines, enabling independent operation in areas without grid coverage and effectively expanding its deployment capabilities in remote agricultural settings.

[0056] The mixing reaction chamber is located at the confluence of two gas channels. Its structure is customized based on gas flow rate and reactant types to ensure thorough mixing and reaction within a short time. Multiple types of sensors are installed inside the chamber and at its outlet, including NH3 concentration detectors, detectors for reactive gases such as NO / NO2 / O3, and particulate matter concentration detection modules based on light scattering or charge acquisition. Through multi-channel data acquisition, a closed-loop monitoring chain covering the entire process from raw material input to reaction product output is formed, providing real-time and accurate gas state parameters for subsequent control systems.

[0057] The core control module of the system is built on embedded processor platforms such as STM32, Raspberry Pi, or FPGA, integrating signal acquisition, control algorithm execution, and PWM output control functions. By receiving data from various gas concentration sensors, the intelligent control system can calculate the concentration deviation between the NH3 input and NO2 output in real time based on algorithms such as PID and fuzzy control. This allows for dynamic adjustment of the PWM duty cycle, precise control of the gas pump flow rate and discharge power, ensuring sufficient ammonia conversion within the reaction chamber without excessive accumulation, and achieving stable, efficient, and automated system operation.

[0058] The closed-loop control strategy dynamically judges the system's operating status based on gas concentration feedback and a preset target concentration. When a large amount of residual ammonia or insufficient NO2 production is detected, the system automatically executes a pressurization or frequency increase strategy to improve the discharge capacity of the air channel; conversely, it adjusts the flow rate by weakening the PWM control signal to prevent over-reaction. In addition, the system supports a limit adjustment range determination function to automatically correct control parameter drift, enhance system robustness and adaptability, and ensure control accuracy and product consistency during long-term operation.

[0059] Example 1

[0060] In large-scale livestock and poultry farms, this system is installed next to the exhaust duct in areas with concentrated ammonia emissions. The air channel receives ambient air via a pump, which then feeds it into the plasma discharge unit to generate highly reactive particles. The ammonia channel is directly connected to the exhaust duct of the livestock shed, and its flow rate is controlled by an adjustable pump. The two gases undergo thorough turbulent mixing in the mixing reaction chamber, generating ammonium nitrate particles. A detection module monitors the concentrations of NH3, NO2, and particulate matter in real time, feeding this data back to the control system. This system dynamically adjusts the pump flow rate and discharge power to achieve efficient ammonia capture and control of byproduct production.

[0061] Example 2

[0062] During fertilization operations in crop greenhouses, this system is mobile and deployed at the exhaust vent inside the greenhouse to collect ammonia-rich waste gas generated during fertilization. The air channel is supplied by external air, while the ammonia channel connects to the waste gas collection hood in the fertilization area via a flexible hose. The ammonia flow rate is precisely regulated by a PWM-controlled air pump. The mixing reaction chamber completes the gas-phase reaction and generates collectable ammonium nitrate particles. A sensor module monitors the reaction efficiency, and the embedded control system optimizes control parameters in real time based on the concentration difference, ensuring stable capture efficiency and energy consumption balance under different fertilization intensities.

[0063] Both of these embodiments achieve rapid reduction of NH3 pollutants and recovery of resource products through dual-channel independent flow control and plasma-activated oxidation reaction. They are highly adaptable and can be flexibly deployed in fixed or mobile scenarios.

[0064] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A dynamic closed-loop dual-channel air plasma ammonia capture intelligent control system, characterized in that, include: Plasma discharge unit, ammonia input unit, mixing reaction chamber, gas product detection module, intelligent control system, The plasma discharge unit is connected to the air input path, and the ammonia input unit is connected to the ammonia channel. Both channels are introduced into the mixing reaction chamber for reaction. The gaseous product detection module is used to collect the concentration information of the reaction products. The intelligent control system is used to adjust the gas input flow rate and discharge power based on the concentration feedback signal to achieve closed-loop control.

2. The system according to claim 1, characterized in that, The plasma discharge unit uses a needle-needle, needle-plate, or dielectric barrier discharge structure to form a discharge chamber.

3. The system according to claim 1, characterized in that, The ammonia input unit includes an adjustable flow rate gas pump and a matching gas delivery pipeline, which enables precise control of the ammonia flow rate.

4. The system according to claim 1, characterized in that, The mixing reaction chamber is a closed structure with two opposing gas inlets, which are respectively connected to the plasma gas and ammonia gas channels, and the airflow inside the chamber mixes at an angle.

5. A gaseous product detection module, characterized in that, It includes multiple sensors, which are installed inside or at the outlet of the mixing reaction chamber, for collecting concentration data of ammonia, reactive gas products, and reaction particles. The concentration data is transmitted to the intelligent control system via a signal line to achieve closed-loop control of the gas concentration.

6. The detection module according to claim 5, characterized in that, The sensors include an ammonia concentration sensor, a nitric oxide concentration sensor, a nitrogen dioxide concentration sensor, an ozone concentration sensor, and a particulate matter concentration sensor.

7. An intelligent control system for dynamically regulating gas input and discharge power, characterized in that, It includes an embedded processing unit, a signal acquisition module, and a drive output module. The embedded processing unit receives multiple concentration signals transmitted by the gas product detection module, executes a real-time control algorithm, and outputs control signals to the drive module to adjust the working state of the gas pump and the discharge device.

8. The control system according to claim 7, characterized in that, The control algorithm executed by the embedded processing unit is proportional-integral-derivative control, fuzzy control, or an incremental adjustment strategy based on concentration difference.

9. A method for capturing and controlling ammonia gas based on a dual-channel plasma structure, characterized in that, Includes the following steps: Step 1: Air and ammonia are introduced into the plasma discharge unit and ammonia input channel respectively by an air pump; Step 2: In the mixing reaction chamber, counter-current mixing and gas-phase reaction are carried out to generate ammonium salt particles; Step 3: Collect gas and particulate matter concentration signals inside or at the outlet of the chamber; Step 4: Based on the detection results, perform real-time control calculations to adjust the gas pump output and discharge power, thereby achieving dynamic adjustment of reaction conditions.

10. The method according to claim 9, characterized in that, The real-time control calculation includes calculating the concentration difference between ammonia and nitrogen dioxide, and adjusting the duty cycle of the PWM control signal in the air channel according to the concentration difference to regulate NO2 production, forming a dynamic closed-loop regulation mechanism.

Images