Carbon dioxide capture and release system for carbonation of greenhouses and control method

Abstract

The application relates to the technical field of agricultural gas treatment, and particularly discloses a carbon dioxide capturing and releasing system for greenhouse carbon increment and a control method. The carbon dioxide capturing and releasing system comprises: an external air treatment unit; a greenhouse air treatment unit; a carbon dioxide adsorption and desorption micro-reaction unit connected to the downstream of a gas path, which comprises micro-reactors A and B arranged in parallel, the inside of the micro-reactors is a multilayer micro-reaction unit stacking structure, and the micro-reactors comprise a paper folding flow control module capable of being reversibly deformed with temperature and an adsorption and desorption module with a pore gradient distribution; a gas path switching unit is used for realizing the switching of gas flow directions under different working conditions; and a monitoring control module is used for controlling the gas path switching and the operation of each unit according to the carbon dioxide concentration and environmental parameters in the greenhouse. The application realizes the direct capturing of carbon dioxide from the atmosphere, the passive self-adaptive adjustment of gas flow and mass transfer based on temperature, the continuous and alternating operation and the quantitative release of greenhouse carbon increment.

Description

Technical Field

[0001] This invention relates to the field of agricultural gas treatment technology, specifically to a carbon dioxide capture and release system and control method for increasing carbon in greenhouses. Background Technology

[0002] Carbon dioxide concentration is one of the important environmental factors affecting the photosynthetic efficiency and yield of greenhouse crops. In facility agriculture production, increasing the carbon dioxide concentration in greenhouses to promote crop growth has been widely adopted. However, existing greenhouse carbon enhancement technologies mostly rely on bottled carbon dioxide, combustion-generated gases, or chemical reactions as carbon dioxide sources. This not only has problems such as high gas source costs and complex operation and maintenance, but also the carbon dioxide supply process is often difficult to accurately match with the real-time demand in the greenhouse, which can easily cause fluctuations in carbon dioxide concentration or even local excess, which can have adverse effects on crop growth and personnel safety.

[0003] In recent years, the technology of capturing carbon dioxide from gases using adsorption materials and releasing it when needed has attracted attention. However, related research has mostly focused on industrial exhaust gas treatment or stationary source emission reduction. There are still certain limitations in the capture efficiency, energy consumption, and continuous operation capability of the system for low-concentration atmospheric carbon dioxide. At the same time, existing carbon dioxide capture devices and greenhouse carbon enhancement systems are usually independent of each other, and the capture, storage, and release processes are decentralized, making it difficult to achieve dynamic control in conjunction with greenhouse environmental parameters, which limits its application in facility agriculture scenarios.

[0004] Furthermore, in actual operation, air humidity and temperature have a significant impact on the performance of carbon dioxide adsorption and desorption. Existing devices mostly rely on fixed flow channels or external control valves to regulate gas flow, which are complex in structure and have a slow response. They are difficult to maintain efficient and stable operation under conditions of frequent switching between adsorption and desorption conditions. For greenhouse environments, it is also necessary to ensure the carbon dioxide supply effect while taking into account operational safety, system reliability, and the feasibility of long-term continuous operation. Therefore, existing technologies still lack an integrated technical solution that can adapt to low-concentration atmospheric conditions, realize the integration of carbon dioxide capture and release, and can dynamically regulate according to changes in carbon dioxide concentration in the greenhouse. Summary of the Invention

[0005] This application provides a carbon dioxide capture and release system and control method for greenhouse carbon enhancement, including: An external air handling unit is used to introduce outside air into the greenhouse; Greenhouse air handling unit, used to introduce air into the greenhouse; A carbon dioxide adsorption and desorption microreactor unit is connected downstream of the gas path of the external air treatment unit and the greenhouse air treatment unit, and includes microreactor A and microreactor B arranged in parallel. A gas path switching unit is located at both ends of the carbon dioxide adsorption and desorption micro-reaction unit. It has a multi-way inlet and outlet valve group that is respectively connected to the external air handling unit and the greenhouse air handling unit, and is used to switch the gas flow direction under different operating conditions. The monitoring and control module is communicatively connected to the external air handling unit, the greenhouse air handling unit, and the gas path switching unit, and is configured to control the gas path switching according to different operating conditions and the obtained carbon dioxide concentration in the greenhouse.

[0006] In one feasible implementation, the external air handling unit includes, in sequence along the air path, a first fan, a pre-filter, and a dryer; the greenhouse air handling unit includes, in sequence along the air path, a second fan, a humidifier, and a heater; the multi-way inlet and outlet valve group includes an inlet valve group one and an outlet valve group one connected to the external air handling unit, and an inlet valve group two and an outlet valve group two connected to the greenhouse air handling unit.

[0007] In one feasible implementation, both microreactor A and microreactor B are modular structures formed by stacking several layers of microreaction units with identical structures along the gas flow direction. Each layer of the microreaction unit sequentially includes: a first origami flow control module; an adsorption and desorption module disposed downstream of the gas path of the first origami flow control module; and a second origami flow control module disposed downstream of the gas path of the adsorption and desorption module.

[0008] In one feasible implementation, both the first origami flow control module and the second origami flow control module are formed by two upper and lower plates arranged opposite each other, and an interleaved origami-type deformable flow channel structure is constructed between the two plates; the origami-type deformable flow channel structure is configured to undergo reversible deformation with the temperature change of the gas passing through: when the gas temperature is low, it undergoes expansion deformation to increase the slit gap; when the gas temperature is high, it undergoes contraction deformation to decrease the slit gap.

[0009] In one feasible implementation, the adsorption and desorption module includes a porous carrier with a three-period minimum surface structure, the surface of which is loaded with an amino-functionalized metal-organic framework adsorbent; wherein the pores inside the porous carrier are distributed in a gradient that gradually decreases along the flow direction of the gas introduced by the external air treatment unit.

[0010] A control method for a carbon dioxide capture and release system for greenhouse carbon enhancement as described in the foregoing technical solution includes the following operating conditions and steps: Executing carbon dioxide adsorption mode: The monitoring and control module opens the first air inlet valve group and the first air outlet valve group, starts the first fan, draws in air from outside the greenhouse, processes it sequentially through the pre-filter and the dryer, and then enters the microreactor A and / or the microreactor B for carbon dioxide capture; the decarbonized gas is discharged back to the outside through the first air outlet valve group. Executing carbon dioxide desorption mode: The monitoring and control module opens the second air inlet valve group and the second air outlet valve group, starts the second fan, draws air from the greenhouse, processes it sequentially through the humidifier and the heater, and then reverses its flow into the microreactor A and / or the microreactor B to desorb and desorb the captured carbon dioxide; the carbon dioxide-rich gas is discharged back into the greenhouse through the second air outlet valve group.

[0011] In one feasible implementation, under the carbon dioxide adsorption condition and the carbon dioxide desorption condition, a flow control adaptive adjustment step is performed respectively: under the carbon dioxide adsorption condition, the cooler ambient air causes the origami-type deformable flow channel structure to expand to increase the slit gap, reduce flow resistance, and increase gas throughput; under the carbon dioxide desorption condition, the high-temperature greenhouse air heated by the heater causes the origami-type deformable flow channel structure to contract to reduce the slit gap, reduce gas velocity, and prolong the residence time of gas in the adsorption and desorption module.

[0012] In one feasible implementation, the monitoring and control module acquires the carbon dioxide concentration in the greenhouse in real time and executes the following adaptive scheduling steps: when the carbon dioxide concentration is higher than a set upper threshold, the gas path switching unit is controlled to make microreactor A and microreactor B simultaneously perform the carbon dioxide adsorption mode or stop operating; when the carbon dioxide concentration is between a set lower threshold and the upper threshold, the gas path switching unit is controlled to make one of microreactor A and microreactor B perform the carbon dioxide adsorption mode and the other perform the carbon dioxide desorption mode, and the switching is performed alternately; when the carbon dioxide concentration is lower than the lower threshold, the gas path switching unit is forcibly controlled to make microreactor A and microreactor B simultaneously perform the carbon dioxide desorption mode.

[0013] In one feasible implementation, the control method further includes an abnormal alarm and environmental parameter preprocessing steps: the monitoring and control module monitors the pressure drop difference between the inlet and outlet of the pre-filter in real time, and issues a filter cleaning prompt when the pressure drop difference exceeds a set threshold; the monitoring and control module acquires the ambient air humidity and greenhouse air humidity in real time: when the ambient air humidity exceeds the set upper limit, the introduced ambient air is controlled to first pass through the dryer for dehumidification before entering the carbon dioxide adsorption and desorption micro-reaction unit; when the greenhouse air humidity is lower than the set lower limit, the introduced greenhouse air is controlled to first pass through the humidifier for humidification before being heated.

[0014] This application provides a carbon dioxide capture and release system and control method for greenhouse carbon enhancement. Compared with the prior art, this application integrates an external air handling unit, a greenhouse air handling unit, a gas path switching unit, a carbon dioxide adsorption and desorption microreactor unit, and a monitoring and control module. This allows low-concentration carbon dioxide in the atmosphere to be captured, desorbed, gas path switched, and fed back to the greenhouse for carbon enhancement within the same system, thereby reducing dependence on external gas sources and improving the overall performance of greenhouse carbon enhancement. Simultaneously, the microreactor unit, with its deformable flow channel and porous carrier coupling module, achieves passive adaptive adjustment of gas flow and mass transfer processes. Furthermore, the alternating operation design of parallel microreactors and the monitoring and control module enable intelligent dynamic regulation based on the greenhouse carbon dioxide concentration. Therefore, this application not only improves the capture efficiency of low-concentration atmospheric carbon dioxide but also enhances the continuous utilization efficiency of greenhouse carbon dioxide, demonstrating excellent integration, controllability, and application value in the agricultural field. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall workflow and communication control topology provided for embodiments of the present invention; Figure 2 A schematic diagram of the multi-layer stacked three-dimensional structure of the carbon dioxide adsorption microreactor provided in an embodiment of the present invention; Figure 3 A schematic diagram of a longitudinal section of a carbon dioxide adsorption microreactor provided in an embodiment of the present invention; Figure 4 This is a three-dimensional structural diagram of a porous carrier provided in an embodiment of the present invention.

[0016] In the diagram: 1. First fan, 2. Pre-filter, 3. Dryer, 4. Second fan, 5. Humidifier, 6. Heater, 7. Inlet valve group 1, 8. Outlet valve group 1, 9. Inlet valve group 2, 10. Outlet valve group 2, 11. Microreactor A, 12. Microreactor B, 13. Carbon dioxide adsorption and desorption microreactor unit, 13a. First origami flow control module, 13b. Adsorption and desorption module, 13c. Second origami flow control module, 14. Porous carrier, 15. Carbon dioxide adsorbent, 16. Monitoring and control module. Detailed Implementation

[0017] To better understand the technical solutions provided in the embodiments of this specification, the technical solutions of the embodiments of this specification will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this specification and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this specification, rather than limitations on the technical solutions of this specification. In the absence of conflict, the embodiments of this specification and the technical features in the embodiments can be combined with each other.

[0018] In this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations. Moreover, 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 limitation, 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. The term "two or more" includes two or more cases.

[0019] Combination Figures 1 to 4 As shown, an embodiment of the present invention provides a carbon dioxide capture and release system for greenhouse carbon increase in a first aspect, comprising: an external air treatment unit, a greenhouse air treatment unit, a carbon dioxide adsorption and desorption microreaction unit 13, a gas path switching unit, and a monitoring and control module 16. Specifically, the external air handling unit is used to introduce air from outside the greenhouse, and includes a first fan 1, a pre-filter 2, and a dryer 3 in sequence along the air path; the greenhouse air handling unit is used to introduce air from inside the greenhouse, and includes a second fan 4, a humidifier 5, and a heater 6 in sequence along the air path; the carbon dioxide adsorption and desorption microreactor unit 13 is connected downstream of the air path of the external air handling unit and the greenhouse air handling unit, and includes microreactors A11 and B12 arranged in parallel; the air path switching unit has a multi-way inlet and outlet valve group that connects to the external air handling unit and the greenhouse air handling unit respectively, including inlet valve group 1 7, outlet valve group 1 8, inlet valve group 2 9, and outlet valve group 2 10, used to switch the gas flow direction under different operating conditions; and a monitoring and control module 16, which is communicatively connected to each of the above components and configured to control the air path switching and the operation of each unit according to different operating conditions and acquired environmental parameters.

[0020] The carbon dioxide capture and release system for greenhouse carbon enhancement provided in this application integrates an external air handling unit, a greenhouse air handling unit, a carbon dioxide adsorption and desorption microreactor unit 13, a gas path switching unit, and a monitoring and control module 16 into a complete gas handling system. This system is used to capture atmospheric carbon dioxide and quantitatively supply it to the greenhouse. During operation, the first fan 1 introduces outside air into the system. The air first passes through a pre-filter 2 to remove dust and suspended impurities, and then is dehumidified using a dryer 3 when the outside humidity is high. The air then enters the carbon dioxide adsorption and desorption microreactor unit 13 via the intake valve group 7, where the internal carbon dioxide adsorbent 15 adsorbs and desorbs the air. Selective adsorption is used to capture atmospheric carbon dioxide. The decarbonized air is discharged back to the outside through the exhaust valve group 8. When the greenhouse needs to increase carbon, the second fan 4 draws air from the greenhouse, humidifies it through the humidifier 5 when the humidity is low, and heats it through the heater 6. Then, it enters the microreactor in reverse through the intake valve group 9. Under high temperature and high humidity conditions, the adsorbent releases the captured carbon dioxide. The carbon dioxide-rich gas is returned to the greenhouse through the exhaust valve group 10 for crop use. In this way, the system can not only increase the carbon in the greenhouse environment without the need for an external carbon dioxide source, but also achieve continuous and controllable greenhouse concentration regulation by switching parallel reactors.

[0021] Please see Figures 2 to 4 As shown, in some examples, microreactors A11 and B12 are further modular structures formed by stacking several layers of microreactor units with consistent structures along the gas flow direction. Each layer of microreactor unit includes, in sequence: a first origami flow control module 13a, an adsorption and desorption module 13b, and a second origami flow control module 13c. The first origami flow control module 13a and the second origami flow control module 13c are both formed by two upper and lower plates arranged opposite to each other, and an interleaved origami deformable flow channel structure is constructed between the two plates.

[0022] In this example, the carbon dioxide adsorption and desorption microreactor 13 adopts a multi-layer stacked structure. The first origami flow control module 13a and the second origami flow control module 13c are located at both ends of the adsorption and desorption module 13b. This origami flow channel structure can passively and reversibly deform with the temperature of the gas passing through. Under adsorption conditions, the incoming air is at a lower temperature, and the origami structure tends to unfold, increasing the slit gap, thereby reducing the overall flow resistance and increasing the gas flux, allowing a larger flow rate of air to pass through to facilitate the capture of low-concentration carbon dioxide. Under desorption conditions, the incoming air is high-temperature greenhouse air heated by the heater 6, and the origami structure tends to contract due to heat, decreasing the slit gap and reducing the gas velocity, thereby effectively extending the residence time of the desorbed gas in the adsorption and desorption module 13b, making the carbon dioxide desorption more complete. This allows the system to automatically achieve flow self-regulation without the need for complex mechanical flow control valves, which is beneficial for the miniaturization and integration of the system.

[0023] like Figure 2 As shown, in some examples, the adsorption and desorption module 13b further includes a porous carrier 14 with a three-period minimum surface structure, the surface of which is loaded with an amino-functionalized metal-organic framework adsorbent, wherein the pores inside the porous carrier 14 are distributed in a gradient that gradually decreases along the flow direction of the gas introduced from the external air treatment unit.

[0024] In this example, the amino-functionalized metal-organic framework adsorbent exhibits excellent carbon dioxide adsorption capacity under low temperature and low humidity conditions, and achieves efficient desorption under high temperature and high humidity conditions. Meanwhile, the porous carrier 14 adopts a three-period minimum surface structure design, which effectively improves the mass transfer effect. Its pore gradient distribution allows outside air to first enter the region with larger pores to maintain high flux under forward adsorption conditions, and then enter the region with gradually decreasing pores, which enhances the mass transfer and adsorption of low-concentration carbon dioxide. In reverse desorption conditions, the gas first enters the region with smaller pores and fully contacts the carbon dioxide adsorbent 15 to promote desorption. As desorption proceeds, the gas flows to the region with larger pores, thereby reducing the frictional resistance and smoothly transporting the carbon dioxide-rich gas back to the greenhouse. The above-mentioned asymmetric structure adapts to the contradiction between low-concentration adsorption and high-concentration release, improving the overall performance of the microreactor.

[0025] Please see Figure 1 As shown, this application also provides a control method for a carbon dioxide capture and release system for greenhouse carbon enhancement in a second aspect, including the following operating conditions and steps: Performing carbon dioxide adsorption operation: The monitoring and control module 16 opens the inlet valve group 7 and the outlet valve group 8, starts the first fan 1, draws in the air outside the greenhouse, and after being processed by the pre-filter 2 and the dryer 3, it enters the microreactor A11 and / or the microreactor B12 for carbon dioxide capture; the decarbonized gas is discharged back to the outside through the outlet valve group 8. Execution of carbon dioxide desorption mode: The monitoring and control module 16 opens the second air inlet valve group 9 and the second air outlet valve group 10, starts the second fan 4, draws air from the greenhouse, processes it in sequence through the humidifier 5 and the heater 6, and then enters the microreactor A11 and / or microreactor B12 in reverse to desorb and desorb the captured carbon dioxide; the carbon dioxide-rich gas is discharged back into the greenhouse through the second air outlet valve group 10.

[0026] This embodiment also discloses a control method for a carbon dioxide capture and release system for greenhouse carbon increase. The control method includes a carbon dioxide adsorption mode and a carbon dioxide desorption mode. The purpose of setting these two modes is to enable the system to automatically complete an integrated cycle process from atmospheric carbon capture to carbon release into the greenhouse according to the carbon increase demand in the greenhouse.

[0027] In some examples, the monitoring and control module 16 further acquires the carbon dioxide concentration in the greenhouse in real time and executes the following adaptive scheduling steps: when the carbon dioxide concentration is higher than the set upper threshold, the control gas path switching unit causes microreactors A11 and B12 to simultaneously perform carbon dioxide adsorption or stop operation; when the carbon dioxide concentration is between the set lower and upper thresholds, the control gas path switching unit causes one of microreactors A11 and B12 to perform carbon dioxide adsorption and the other to perform carbon dioxide desorption, and performs alternating cyclic switching; when the carbon dioxide concentration is lower than the lower threshold, the control gas path switching unit is forced to cause microreactors A11 and B12 to simultaneously perform carbon dioxide desorption.

[0028] In this example, the monitoring and control module 16 performs coordinated closed-loop control of the dual microreactors by setting a carbon dioxide concentration threshold. When the carbon dioxide in the greenhouse is sufficient (above the upper limit threshold), the system mainly performs adsorption and storage or shuts down to prevent excessive accumulation of concentration. When the carbon dioxide in the greenhouse is consumed to the normal fluctuation range, the alternating cycle of adsorption and desorption can ensure a continuous and stable carbon supply. When photosynthesis is vigorous in the early morning and the carbon dioxide is extremely low (below the lower limit threshold), the dual microreactors are forced to simultaneously desorb to rapidly increase the concentration with double the capacity, thereby improving the system's carbon supply flexibility.

[0029] In some examples, this control method further includes anomaly alarm and environmental parameter preprocessing steps: the monitoring and control module 16 monitors the pressure drop difference between the inlet and outlet of the pre-filter 2 in real time, and issues a filter cleaning prompt when the pressure drop difference exceeds the set threshold; and the monitoring and control module 16 acquires the ambient air humidity and greenhouse air humidity in real time: when the ambient air humidity exceeds the set upper limit, the introduced ambient air is controlled to first pass through the dryer 3 for dehumidification before entering the carbon dioxide adsorption and desorption micro-reaction unit 13; when the greenhouse air humidity is lower than the set lower limit, the introduced greenhouse air is controlled to first pass through the humidifier 5 for humidification before being heated.

[0030] In this example, the control method incorporates logic for system safety and adsorption protection. During long-term use, dust will gradually accumulate in the pre-filter 2. By monitoring the pressure drop difference, a filter blockage warning is issued, which can promptly prompt cleaning to ensure air intake. In response to the impact of ambient humidity on the activity of carbon dioxide adsorbent 15, the system switches to dehumidification when the outside humidity is high to avoid condensation, and humidifies when the greenhouse humidity is low. This ensures that the temperature and humidity of the air entering the microreactor always fall within the optimal adsorption and desorption operating window, thereby further improving the system's adaptability to different climates and its reliability for continuous operation.

[0031] Specific application examples verification Example 1: This example uses a multi-span greenhouse with an effective volume of 600 m³ as the application object. The crop in the greenhouse is dragon fruit. The target carbon dioxide concentration control range during greenhouse operation is set at 850–1000 ppm. When the system starts, the monitoring and control module 16 detects that the initial carbon dioxide concentration in the greenhouse is 620 ppm, which is lower than the set target lower limit. The first fan 1 starts, introducing outside air into the greenhouse at a flow rate of 70 m³·h⁻¹. The outside air carbon dioxide concentration is approximately 405 ppm, and the temperature is 19°C. The relative humidity is 60%. Air passes sequentially through pre-filter 2 (initial pressure drop approximately 80 Pa) and dryer 3, reducing the relative humidity to 38% before entering inlet valve group 7. Microreactors A11 and B12 are initially in adsorption mode. The air temperature entering the microreactors is 18–20°C. Folding flow control modules 13a and 13c are in the deployed state. The average equivalent slit width of the flow channel is approximately 1.2 mm, and the gas flux of a single microreactor is approximately 35 m³·h⁻¹. Under these conditions, the gas flux of a single microreactor... The average carbon dioxide capture rate of the reactor is approximately 60%. After 2 hours of system operation, the monitoring and control module 16 detected a decrease in the carbon dioxide concentration in the greenhouse to 480 ppm, triggering the carbon increase control logic: microreactor A continues adsorption operation, microreactor B switches to desorption mode, the second fan 4 starts, drawing air from the greenhouse at a volume of 45 m³·h⁻¹, adjusting the relative humidity to 85% by the humidifier 5, and heating it to 85°C by the heater 6 before it enters microreactor B through the air inlet valve group 2 9. Under desorption mode, the paper flow control module... Due to the increase in gas temperature, the gas contracts, and the equivalent slit width of the flow channel decreases to about 0.5 mm. The gas flow rate decreases by about 40%, and the average residence time of the gas in the adsorption and desorption module 13b is extended to 2.3 s. After desorption, the carbon dioxide concentration in the gas increases to 3100–3400 ppm and is returned to the greenhouse through the outlet valve group 2 10. Under the above alternating operation mode, the carbon dioxide concentration in the greenhouse is stably maintained in the range of 870–960 ppm, and the system does not show obvious flow imbalance or adsorption performance degradation.

[0032] Example 2: An Example of Rapid Carbon Supplementation under Low-Concentration Conditions Achieved Through Simultaneous Analysis by Two Microreactors This embodiment targets the low carbon dioxide conditions before the start of intense photosynthesis in early morning. The greenhouse volume is 400 m³, and the initial carbon dioxide concentration is 360 ppm. After the monitoring and control module 16 detects that the carbon dioxide concentration in the greenhouse is lower than the set lower limit of 600 ppm, it controls the inlet valve group 7 and outlet valve group 8 to close, while simultaneously opening the inlet valve group 9 and outlet valve group 10, so that microreactors A and B simultaneously enter the desorption mode. The second fan 4 starts, and the air volume is set to 60 m³·h⁻¹. The air is adjusted to a relatively stable temperature by the humidifier 5. The humidity is 90%, and the gas is heated to 85°C by heater 6 before entering the microreactor. At this time, the slit width of the origami flow control module is reduced to 0.45 mm, and the total pressure drop of the system is about 620 Pa. After 20 minutes of analysis and operation, the carbon dioxide concentration in the gas flowing back into the greenhouse is stable at 3600–4200 ppm. Within 35 minutes, the overall carbon dioxide concentration in the greenhouse increases from 360 ppm to 820 ppm. When the concentration reaches the target range, the system automatically switches to the alternating operation mode described in Example 1 to prevent excessive accumulation of carbon dioxide.

[0033] Example 3: Adaptive Capture Operation Example under High Humidity Environment This embodiment illustrates the system's operation in a high-humidity environment during the rainy season. The outside air temperature in the greenhouse is 23°C, the relative humidity is 88%, and the carbon dioxide concentration is 420 ppm. After the first fan 1 is started, the monitoring and control module 16 detects that the outside air humidity exceeds the preset threshold of 70%. It controls the air path to ensure that all air passes through the dryer 3, reducing the relative humidity of the air at the dryer outlet to 42% and the dew point temperature to below 9°C to prevent condensation in the adsorption module. Under adsorption conditions, the air temperature entering the microreactor is 21°C, the origami flow control module remains in the extended state, and the system pressure drop is maintained below 480 Pa. After 10 hours of continuous adsorption operation, the adsorbent does not show significant performance degradation. When the system switches to desorption conditions, the air in the greenhouse is heated to 70°C and humidified to 82%. The origami flow control module automatically contracts, and the gas flow rate decreases from 70 m³·h⁻¹ under adsorption conditions to 42 m³·h⁻¹, increasing the desorption efficiency by approximately 28%. This embodiment demonstrates that the system can still achieve stable operation under high-humidity conditions.

[0034] Example 4: Scale-up Application of Multilayer Stacked Microreactors In this embodiment, each microreactor is composed of 24 layers of carbon dioxide adsorption and desorption microreactor units 13 stacked together, each layer being 5 mm thick, with a total height of 120 mm for a single microreactor. The average pore size of each layer of TPMS porous carrier gradually transitions from 1.6 mm at the inlet side to 0.6 mm at the outlet side. Under adsorption conditions, the air flow rate processed by a single microreactor is 40 m³·h⁻¹, with an inlet temperature of 20°C and a relative humidity of 40%. The carbon dioxide capture rate per unit time of a single reactor is approximately 0.48 g·h⁻¹. Under desorption conditions, the inlet gas temperature is 80°C and the relative humidity is 85%. The carbon dioxide concentration in the desorbed gas remains stable above 3000 ppm. By increasing the number of microreactors to four in parallel, the system's processing capacity can be increased to approximately 1.9 g·h⁻¹ of carbon dioxide recovery capacity without changing the single-layer structure. This embodiment demonstrates that the microreactor structure of the present invention has good modular scalability and is suitable for the carbon dioxide capture and controlled release needs of facility agriculture greenhouses of different sizes.

[0035] The above are merely embodiments of this application and are not intended to limit this application. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A carbon dioxide capture and release system for greenhouse carbon enhancement, characterized in that, include: An external air handling unit is used to introduce outside air into the greenhouse; Greenhouse air handling unit, used to introduce air into the greenhouse; The carbon dioxide adsorption and desorption microreactor unit (13) is connected downstream of the gas path of the external air treatment unit and the greenhouse air treatment unit, and includes microreactor A (11) and microreactor B (12) arranged in parallel. The gas path switching unit is located at both ends of the carbon dioxide adsorption and desorption micro-reaction unit (13). It has a multi-way inlet and outlet valve group that is connected to the external air treatment unit and the greenhouse air treatment unit respectively, and is used to switch the gas flow direction under different working conditions. The monitoring and control module (16) is communicatively connected to the external air handling unit, the greenhouse air handling unit and the gas path switching unit, respectively, and is configured to control the gas path switching according to different operating conditions and the obtained carbon dioxide concentration in the greenhouse.

2. The carbon dioxide capture and release system for greenhouse carbon enhancement according to claim 1, characterized in that, The external air handling unit includes, in sequence along the air path, a first fan (1), a pre-filter (2), and a dryer (3); The greenhouse air handling unit includes, in sequence along the air path, a second fan (4), a humidifier (5), and a heater (6); The multi-way air inlet and outlet valve group includes an inlet valve group one (7) and an outlet valve group one (8) connected to the external air handling unit, and an inlet valve group two (9) and an outlet valve group two (10) connected to the greenhouse air handling unit.

3. The carbon dioxide capture and release system for greenhouse carbon enhancement according to claim 1, characterized in that, Both microreactor A (11) and microreactor B (12) are modular structures formed by stacking several layers of microreactor units with identical structures along the gas flow direction. Each layer of the microreactor unit includes, in sequence: First origami flow control module (13a); An adsorption and desorption module (13b) is located downstream of the gas path of the first origami flow control module (13a); and The second origami flow control module (13c) is located downstream of the gas path of the adsorption and desorption module (13b).

4. The carbon dioxide capture and release system for greenhouse carbon enhancement according to claim 3, characterized in that, Both the first origami flow control module (13a) and the second origami flow control module (13c) are formed by two upper and lower plates arranged opposite each other, and an origami-style deformable flow channel structure is constructed between the two plates in an alternating manner; The origami-type deformable flow channel structure is configured to undergo reversible deformation in response to changes in the temperature of the gas passing through it: when the gas temperature is low, it expands to increase the slit gap; when the gas temperature is high, it contracts to decrease the slit gap.

5. The carbon dioxide capture and release system for greenhouse carbon enhancement according to claim 3, characterized in that, The adsorption and desorption module (13b) includes a porous carrier (14) with a three-period minimum surface structure, the surface of which is loaded with an amino-functionalized metal-organic framework adsorbent. The pores inside the porous carrier (14) are distributed in a gradient that gradually decreases along the flow direction of the gas introduced by the external air treatment unit.

6. A control method applied to a carbon dioxide capture and release system for greenhouse carbon enhancement as described in any one of claims 1-5, characterized in that, The following operating conditions and procedures are included: Perform carbon dioxide adsorption operation: The monitoring and control module (16) opens the first air inlet valve group (7) and the first air outlet valve group (8), starts the first fan (1), draws in air from outside the greenhouse, processes it sequentially through the pre-filter (2) and the dryer (3), and then enters the microreactor A (11) and / or the microreactor B (12) for carbon dioxide capture; the decarbonized gas is discharged back to the outside through the first air outlet valve group (8); Perform carbon dioxide stripping operation: The monitoring and control module (16) opens the second air inlet valve group (9) and the second air outlet valve group (10), starts the second fan (4), draws air from the greenhouse and processes it through the humidifier (5) and the heater (6) in sequence, and then enters the microreactor A (11) and / or the microreactor B (12) to desorb and analyze the captured carbon dioxide; the carbon dioxide-rich gas is discharged back into the greenhouse through the second air outlet valve group (10).

7. The control method for a carbon dioxide capture and release system for greenhouse carbon enhancement according to claim 6, characterized in that, When the carbon dioxide adsorption-desorption microreactor (13) adopts the structure as described in claim 4, the flow control adaptive adjustment step is executed under the carbon dioxide adsorption condition and the carbon dioxide desorption condition, respectively: Under the carbon dioxide adsorption condition, the cooler ambient air causes the origami-type deformable flow channel structure to unfold, thereby increasing the slit gap, reducing flow resistance, and increasing gas throughput. Under the carbon dioxide desorption condition, the high-temperature greenhouse air heated by the heater (6) causes the origami-type deformable flow channel structure to shrink to reduce the slit gap, reduce the gas flow rate and prolong the residence time of the gas in the adsorption desorption module (13b).

8. The control method for a carbon dioxide capture and release system for greenhouse carbon enhancement according to claim 6, characterized in that, The monitoring and control module (16) acquires the carbon dioxide concentration in the greenhouse in real time and executes the following adaptive scheduling steps: When the carbon dioxide concentration is higher than the set upper limit threshold, the gas path switching unit is controlled to make the microreactor A (11) and the microreactor B (12) simultaneously perform the carbon dioxide adsorption operation or stop operating. When the carbon dioxide concentration is between the set lower threshold and the upper threshold, the gas path switching unit is controlled to make one of the microreactors A (11) and B (12) perform the carbon dioxide adsorption mode and the other perform the carbon dioxide desorption mode, and the switching is performed alternately. When the carbon dioxide concentration is lower than the lower limit threshold, the gas path switching unit is forcibly controlled to make microreactor A (11) and microreactor B (12) simultaneously perform the carbon dioxide desorption operation.

9. The control method for a carbon dioxide capture and release system for greenhouse carbon enhancement according to claim 6, characterized in that, It also includes abnormal alarm and environmental parameter preprocessing steps: The monitoring and control module (16) monitors the pressure drop difference between the inlet and outlet of the pre-filter (2) in real time, and issues a filter cleaning prompt when the pressure drop difference exceeds the set threshold. The monitoring and control module (16) acquires the ambient air humidity and greenhouse air humidity in real time: when the ambient air humidity exceeds the set upper limit, the introduced ambient air is controlled to pass through the dryer (3) for dehumidification before entering the carbon dioxide adsorption and desorption micro-reaction unit (13); when the greenhouse air humidity is lower than the set lower limit, the introduced greenhouse air is controlled to pass through the humidifier (5) for humidification before being heated.

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