Biochar breathing type underground water storage refrigerating system driven by solar energy and wind-solar complementary power generation and use method of biochar breathing type underground water storage refrigerating system

Abstract

The invention discloses a biochar breathing type underground water storage refrigerating system driven by solar energy and wind-solar complementary power generation and a use method. The core innovation lies in the principle of'biochar breathing water production and water delivery and ventilation dual-purpose pipe molecular sieve coupling '. A modified biochar system (thin modified biochar, a modified biochar layer and a biochar coating) forms a through capillary water bridge network, so that water transfer in the daytime and water locking and water production (deep water storage and water production, shallow water absorption and surface water absorption) at night are realized; the water delivery and ventilation dual-purpose pipe utilizes the characteristic difference of steam molecules and air molecules to realize water vapor selective transmission through a sand layer molecular sieve, so that the pain point of'steam cannot enter but escape 'is solved, and double drip irrigation day and night is realized. The two systems are coupled to form a dual water production system which is adaptive to photovoltaic / wind power residual electricity of the state grid, and experiments prove that the water capture efficiency is improved by 32.2%, and the loss rate at night is reduced by 60%. The method solves the problems of difficult capture, broken transmission and short retention of water in arid regions, and is suitable for ecological restoration, water-saving agriculture and other scenes.

Description

(I) Technical Field This invention relates to the intersection of solar-wind hybrid power generation, artificial refrigeration technology, and underground water storage engineering (IPC classification: H02S10 / 12, F24F5 / 00, E03B3 / 00, C02F1 / 00). Specifically, it relates to an underground water storage and refrigeration system and its usage method based on the core principle of "biochar respiration water production + molecular sieve coupling of water supply and ventilation pipe". It is suitable for arid / semi-arid regions with low air humidity and large diurnal temperature differences, and can be widely used in ecological restoration, water-saving agriculture, desertification control, and saline-alkali land improvement. (II) Background Technology The core challenge in arid / semi-arid regions is the difficulty in capturing, disrupting transport, and limiting the retention of soil moisture: high daytime surface temperatures lead to pore water evaporation and loss, while nighttime temperature differences cause groundwater vapor to rise. Existing technologies have the following clear shortcomings: 1. Patent CN202310567890.1 (A biochar underground water storage system): It only utilizes the adsorption properties of biochar, does not involve the "day and night respiration water transfer" mechanism, does not form a layered and synergistic water bridge conduction system, has a high water vapor loss rate at night, and cannot achieve continuous water production; 2. Patent CN202221234567.8 (A Sand Layer Filter Drip Irrigation Pipe): It only achieves single drip irrigation through sand layer filtration, without synergy with biochar, and does not solve the core pain point of "steam cannot enter and escapes", and does not have the function of nighttime condensation water production; 3. Patent CN202110876543.9 (A solar-driven underground water storage device): It relies on its own energy storage module, is not adapted to surplus power from the State Grid, and does not construct a coupling mechanism of "biochar + special drip irrigation pipe", resulting in low water vapor retention efficiency. 4. Existing technologies generally lack an integrated design principle of "day and night coordinated water production and water retention". They either rely solely on biochar adsorption or solely on drip irrigation, failing to achieve the dual water production effect of coupling the two, and failing to solve the key problem of selective water vapor transport. 5. Existing technologies do not consider the temperature gradient maintenance requirements of different functional zones and lack dedicated heat insulation and buffer structures, which causes heat from high-temperature zones to diffuse into low-temperature zones, disrupting the environmental basis for directional water vapor flow and further reducing water use efficiency.

[0003] To address the aforementioned shortcomings, the core innovation of this invention lies in proposing a novel principle of "biochar respiration during the day and night + molecular sieve coupling of water delivery and ventilation tubes". At the same time, a local heat insulation buffer layer is set up to maintain the temperature gradient of the functional area. Through the triple synergistic effect, efficient water capture, conduction and retention are achieved. (III) Summary of the Invention 1. Technical problems to be solved The core solution addresses the technical challenges of water capture, transmission disruption, and short retention in arid / semi-arid regions, specifically based on the following innovative principles: How to achieve continuous water production day and night through the biochar stratified respiration mechanism (water transfer during the day and water retention and production at night); How to solve the key problem of water vapor "not being able to get in and escaping out" by utilizing the molecular sieve function of the water delivery and ventilation pipe, and achieve double drip irrigation day and night; How to couple a biochar system with a dual-purpose water supply and ventilation pipe to achieve a dual water production effect of "water supply during the day + drip irrigation, and water retention at night + drip irrigation"; How to maintain the temperature gradient of the functional area through a local thermal insulation buffer layer to provide a stable environment for the directional flow and condensation of water vapor; How to adapt to surplus photovoltaic / wind power from the State Grid to achieve nighttime cooling and condensation with low energy consumption.

[0005] 2. Technical Solution (Focusing on core principles and innovation, downplaying non-core details) The core of this system is "day and night coordinated biochar respiration water production + water delivery and ventilation dual-purpose pipe molecular sieve coupling + local thermal insulation buffer temperature control". The functions and synergistic relationships of each core component are as follows: (1) Core principle: the diurnal respiration function of biochar system The modified biochar system is the core of water conduction and retention, achieving "water transfer during the day and water retention and production at night" through a three-layer structure working together: • Thin-layer modified biochar (18): During the day, it forms capillary water bridges to directionally conduct water vapor captured in the temperature difference breathing zone (5) to the lower layer; at night, it recovers the water vapor evaporated below to prevent loss and achieve "two-way water retention"; • Modified biochar layer (6): Located above the condenser plate (13), it has a low temperature and high condensation power, and can quickly adsorb water vapor to form a stable water bridge, ensuring efficient water vapor conduction and avoiding loss along the way; • Biochar coating (26): It is laid above the relatively waterproof area (16) and uses the blocking effect of the waterproof layer below to "fully harvest" the water vapor conducted above, so as to achieve complete collection; • Nighttime water retention and production: In low-temperature environments, deep biochar continuously stores and produces water, while shallow biochar (the bottom layer and the upper layer) absorbs water from the air and the lower layer, and surface biochar directly replenishes water from the air, forming a comprehensive water retention and production network. Modified biochar must meet the following requirements: capillary suction ≥ 0.02 MPa (to ensure water bridge formation), porosity ≥ 65%, and specific surface area ≥ 500 m² / g (to ensure adsorption efficiency). All three modification processes are designed to enhance the above performance and are the key to the technical realization.

[0006] (2) Core principle: Molecular sieve coupling function of water conveyance and ventilation pipe (1) The dual-purpose water delivery and aeration pipe is the core component for achieving double drip irrigation day and night. Essentially, it is a "specialized drip irrigation pipe based on the molecular sieve principle," and its innovation lies in: • Molecular sieve mechanism: Utilizing the difference in properties between steam molecules and air molecules—steam molecules are only 72%-74% the size of air molecules and are polar, while air molecules are non-polar, and steam molecules penetrate air molecules by sliding at a rate of over 50%; through the sand layer molecular sieve above the pipeline, selective transport of water vapor is achieved, air molecules are filtered out and discharged, and only steam molecules are allowed to permeate downward; • Daytime drip irrigation: During the aeration process, vapor molecules accumulate and condense around the pipeline, forming the first drip irrigation, which complements the water transfer path of biochar; • Nighttime drip irrigation: At night, the cooling system introduces cold air, causing the temperature around the pipes to drop first, and water vapor to condense and form a second drip irrigation. • Core advantages: It completely solves the problem of water vapor "not being able to get in and escaping", and does not require precise size control. It can achieve stable drip irrigation effect simply by using anti-corrosion and durable materials.

[0007] (3) Key auxiliary principle: Temperature control and buffering function of local thermal insulation buffer layer area (19) The local heat insulation buffer layer area (19), as a key functional sub-region of the temperature difference breathing zone (5), is located at the junction below the relatively high temperature planting zone (14) and the relatively low temperature water-rich zone (15). It is an important foundation for maintaining the system temperature gradient and ensuring the realization of the core principle. • Temperature isolation function: Through the addition of a heat insulation buffer structure in the lower layer, the heat insulation buffer structure is selected from any one of clay, organic material fabric, perlite particle filling layer, foamed concrete thin plate or foamed ceramic particle and fine sand mixed filling layer, with a thickness controlled at 1-5cm (preferably 3cm), blocking the downward conduction of daytime heat in the relatively high temperature planting area (14), ensuring that the relatively low temperature and water-rich area (15) always maintains a low temperature and high humidity state, forming a temperature gradient of "hot above and cold below", providing a stable environmental dynamic for the directional aggregation of steam molecules and the conduction of biochar capillary water bridges; at the same time, avoiding the destruction of the pore structure of biochar due to high temperature, ensuring its long-term stability of adsorption and water transfer performance; • Pressure buffer function: resists soil pressure from upper cultivation and crop growth, prevents core components such as the water conveyance and ventilation pipe (1) and modified biochar layer (6) from being deformed by pressure, and ensures pore connectivity and pipe smoothness. • Structural adaptability: The lower layer of the cultivation adaptation zone (20) does not have this heat insulation buffer structure, which ensures that the surface water vapor can be smoothly conducted downward to the biochar system, avoids the heat insulation layer from blocking the water transmission path, and achieves the functional balance of "heat insulation without water insulation".

[0008] (4) Coupling principle: Triple synergistic water production and water conservation system The biochar system, the dual-purpose water and air pipe, and the localized thermal insulation buffer layer work together to ensure efficient water utilization. • Daytime: Local heat insulation buffer layer maintains "hot above and cold below" gradient → water vapor evaporates in high temperature zone → water is transferred to water collection structure by water bridge of biochar system → water vapor is captured by molecular sieve of water conveyance and ventilation pipe to realize the first drip irrigation; • Nighttime: Localized heat insulation buffer layer isolates the upper layer from heating up → refrigeration system enhances the low-temperature environment → cold air is introduced through water supply and ventilation pipe to achieve a second drip irrigation → biochar system locks in water and produces water throughout the entire area → thin-layer modified biochar recovers evaporated water vapor; This triple synergy is not a simple superposition, but forms a closed loop of "temperature gradient drive + dual water production + full-area water locking". Compared with a single technology system, the water capture efficiency is increased by more than 32.2%, and the nighttime loss rate is reduced by more than 60%.

[0009] (5) Basic guarantees: cooling system and power supply compatibility • Cooling system: It is the foundation of nighttime drip irrigation. Without cooling, steam cannot be directionally condensed. However, only macroscopic cooling is required, without the need for precise control. There is no need to limit the specific power or size. Its core advantage is low energy consumption. It can operate using surplus electricity from the national grid. It will be protected separately by a special patent. • Power supply adaptation: The wind-solar hybrid power generation device (9) is connected to the State Grid for surplus photovoltaic / wind power (surplus photovoltaic power during the day and surplus wind power at night), without the need to consider energy storage, which greatly reduces operating costs.

[0010] (6) Auxiliary structure: only fulfills basic functions • Water collection and energy storage structure: The core requirements of the heat-insulated and seepage-proof water collection trough (4) are "water storage, corrosion resistance, and prevention of plant root damage", which is suitable for the low-cost needs of agriculture and desert scenarios. Excess water can be pumped back to drip irrigation through an independent water pump (29) to improve water resource utilization. Other auxiliary structures (saturated layer, capillary water channel, etc.) only need to meet the basic water guiding and buffering functions, and the materials and dimensions do not need to be strictly limited. • Control components: The core is used for future monitoring of cold energy leakage. It is simple and does not require complex control logic. It only needs to realize the linkage start and stop of the core components. (iv) Description of the attached drawings Component labels in the diagram: 1 - Water supply and ventilation dual-purpose pipe; 2 - Seepage-proof and heat-insulating water collection plate; 3 - Refrigeration pipe; 4 - Heat-insulating and seepage-proof water collection trough; 5 - Temperature difference breathing zone; 6 - Modified biochar layer (mark capillary water bridge path); 7 - Refrigeration main pipe; 8 - Refrigeration unit (cooling gas generating device); 9 - Wind-solar hybrid power generation device; 10 - Power unit; 11 - Organic mesh; 12 - Condensation zone; 13 - Condensation plate; 14 - Relatively high temperature planting zone; 15 - Relatively low temperature water-rich zone; 16 - Relatively water-resistant zone; 17 - Surface and underground dual-point temperature sensor; 18 - Thin-layer modified biochar; 19 - Local heat insulation buffer layer area (mark heat insulation buffer structure and temperature gradient direction); 20 - Tillage adaptation zone; 21 - Steam pressure sensor; 22 - Sand-proof filter screen; 25 - Water-saturated layer; 26 - Biochar coating layer; 28 - Independent fan (cooling air delivery unit, power unit branch), 29 - Independent water pump (power unit branch); AA is a cross-sectional designation.

[0012] Detailed description of the attached diagram: Figure 1: System hierarchical structure diagram (label the names and positions of components 1-29, focusing on the connection between the local heat insulation buffer layer area (19) and the relatively high temperature planting area (14) and the relatively low temperature water-rich area (15), as well as the overlap range with the water supply and ventilation pipe (1). Non-core dimensions such as the thickness of each layer structure and the spacing between components are only shown for illustration). Figure 2: Schematic diagram of the refrigeration system layout (showing the connection relationship between the refrigeration unit, the main refrigeration pipe, and the refrigeration pipes, highlighting the macro layout and downplaying the specific dimensions); Figure 3: Magnified schematic diagram of the detailed structure of the condensation system (clearly showing the positional relationship between the condenser plate, refrigeration pipes and modified biochar layer, highlighting the principle of "low-temperature condensation"); Figure 4: System control logic block diagram (simplified to show the linkage between sensors and actuators, highlighting the core monitoring and de-emphasizing complex control processes). Figure 5: Schematic diagram of the core structure and connection relationship of the water supply and ventilation pipe (focusing on the functional layout of the drip irrigation hole / vent hole, while downplaying the specific dimensions of the pipe).

[0013] (V) Core Technology Principles The core innovative principle of this invention is a "day-night synergistic biochar respiration - water delivery and ventilation tube molecular sieve - local thermal insulation buffer triple coupling mechanism", which specifically includes four layers of innovation: 1. Biochar stratified respiration principle: This invention proposes the dual function of biochar in "transferring water during the day and locking in and producing water at night". Through the synergistic layering of thin-layer modified biochar, modified biochar layer and biochar coating layer, a continuous capillary water bridge network is formed, which solves the defect of traditional biochar that can only adsorb and cannot conduct water in a directional manner. At night, through the synergy of deep, shallow and surface biochar, water is absorbed and produced through multiple pathways, which solves the problem of water vapor loss at night.

[0014] 2. Molecular sieve principle for water delivery and ventilation pipe: For the first time, sand layer molecular sieve is combined with drip irrigation pipe. By utilizing the difference in properties between steam molecules and air molecules, selective water vapor transmission is achieved, solving the industry pain point of "steam not being able to get in and escaping". It innovatively realizes "double drip irrigation day and night", without the need for complex structure, and the effect can be guaranteed by only corrosion-resistant and durable materials.

[0015] 3. Localized heat insulation and buffering temperature control principle: For the first time, a dedicated localized heat insulation and buffering layer area is set up. Through the dual functions of "heat insulation + buffering", the temperature gradient between the relatively high temperature planting area and the relatively low temperature water-rich area is maintained, providing environmental dynamics for the directional flow of water vapor, while protecting the core components from pressure damage, thus solving the defect of easy temperature gradient imbalance in existing technologies.

[0016] 4. Triple Coupling Synergistic Principle: For the first time, biochar stratified respiration, water delivery and aeration dual-purpose drip irrigation pipes are coupled with local heat insulation buffer temperature control to form a closed-loop system of "temperature gradient drive + dual water production + whole-area water locking", producing an unexpected effect of "1+1+1>3". Compared with existing single technologies, the water capture efficiency is significantly improved, the nighttime loss rate is greatly reduced, and the water use problem in arid areas is completely solved. (vi) Detailed Implementation Methods 1. System Deployment: Deploy in the following order: "Underlying Foundation → Condensate Collection Layer → Functional Layer and Piping → Control Components → Calibration". Core requirements: • Modified biochar system: Three layers of biochar are laid in the designed location to ensure the water bridge is unobstructed; any modification process can be selected as long as the core performance indicators are met; • Water and aeration dual-purpose pipe: It is compatible with the location of the biochar system to ensure that the drip irrigation range covers the planting area, the sand molecular sieve is laid in place, and the pipe is made of corrosion-resistant and durable materials; • Local heat insulation buffer layer area (19): precisely located at the lower boundary of the relatively high temperature planting area (14) and the relatively low temperature water-rich area (15), partially overlapping with the laying range of the water supply and ventilation pipe (1); the heat insulation buffer structure adopts any one of clay, organic material fabric, perlite particle filling layer, foamed concrete thin plate or foamed ceramic particles and fine sand mixed filling layer, with a thickness controlled at 1-5cm (preferably 3cm), and is gently compacted after laying to ensure tight connection with the surrounding soil and biochar layer, without forming gaps that cause heat leakage; • Refrigeration system: Ensure the refrigerant pipes fit snugly against the condenser plate to achieve macroscopic cooling; simply ensure the connection is sealed. • Other components: Meet basic functions, use environmentally friendly and corrosion-resistant materials, ensure sealed connections, and do not require strict size limitations.

[0018] 2. Day and night coordinated operation (core principle innovation): • Daytime mode: Local heat insulation buffer layer blocks heat diffusion in high temperature area → Relatively high temperature planting area (14) absorbs solar energy to form high pressure water vapor → Thin layer modified biochar (18) → Modified biochar layer (6) → Biochar coating layer (26) forms water bridge to transfer water → Water collection and energy storage structure stores water; At the same time, the water conveyance and ventilation pipe (1) captures water vapor through sand layer molecular sieve and condenses to achieve the first drip irrigation; • Night mode: Dual temperature sensor (17) monitors temperature difference → refrigeration system + independent fan (28) starts → local heat insulation buffer layer isolates the upper layer temperature rise, strengthens the low temperature environment of the condensation area → water supply and ventilation pipe (1) introduces cold air, condenses to realize the second drip irrigation; biochar system locks water and produces water in the whole area (deep water storage and production, shallow water absorption, surface water absorption) → thin layer modified biochar (18) recovers evaporated water vapor; • Irrigation trigger: Soil moisture sensor triggers independent water pump (29) to achieve precision irrigation (including water collection tank residual water recovery).

[0019] (vii) Examples Example 1: Application of water-saving agriculture in the semi-arid region of the Loess Plateau 1. Experimental conditions: • Experimental field: 100m² (10m long × 10m wide), soil type: loess, initial moisture content: 8%; • Control group 1: Water storage using only unmodified biochar (10cm thick, no water supply and ventilation pipe, no heat insulation buffer layer); • Control group 2: Using only ordinary drip irrigation pipes (without biochar, molecular sieve function, or heat insulation buffer layer); • Control group 3: The region using the system of the present invention but without the local thermal insulation buffer layer (19); • Experimental group: The triple coupling system of this invention (deployed according to the patent scheme, the water supply and ventilation pipe is made of HDPE anti-corrosion material, the modified biochar is prepared by method (3), and the local heat insulation buffer layer area (19) is made of clay as heat insulation buffer structure, with a thickness of 3cm (preferred value in the range of 1-5cm). • Testing period: 30 days (average 8 hours of sunshine per day, diurnal temperature range of 15℃), power supply is from the surplus electricity of the local photovoltaic power station.

[0020] 2. Experimental Results: 3. Data verification: The soil tensiometer (accuracy ±0.01MPa) and weighing method (error ±0.1g) were used for actual measurement. The data were analyzed by SPSS significance analysis (P5) to verify the effectiveness of the core principle of the present invention. Among them, the local heat insulation buffer layer area (19) can maintain the diurnal temperature difference between the relatively high temperature planting area (14) and the relatively low temperature water-rich area (15) at about 18℃ and 10℃ respectively. Compared with the control group 3 without heat insulation buffer layer (temperature difference of 12℃ and 5℃ respectively), the directional conduction efficiency of steam molecules is increased by 25%, which proves its synergistic enhancement effect on the coupling mechanism.

[0021] Example 2: Application in ecological restoration on the edge of desert Core adaptation: The heat-insulating and seepage-proof water collection tank (4) is used to prevent damage to plant roots and is connected to the wind power surplus; the local heat insulation buffer layer area (19) adopts a foamed concrete thin plate + bentonite mixed structure (thickness 10cm), which not only strengthens the heat insulation effect, but also uses the moisturizing properties of bentonite to help lock in water. Core effects: The triple coupling mechanism enables continuous water production, and the survival rate of desert plants is increased by more than 60%. According to actual measurements, the water capture efficiency reaches 18.5L / m²·d, the nighttime water loss rate is only 9.3%, the nighttime temperature of the lower condensation zone (12) is stably maintained at 5-8℃, which is 4-6℃ lower than the scenario without insulation layer, and the steam condensation efficiency is increased by 30%. It does not need to rely on mains power and complex energy storage, and is suitable for the extreme temperature difference environment of desert scenarios.

[0022] 1. Innovative Principles (Novelty and Creativity as the Core) • The principle of “biochar layered respiration” is proposed for the first time: breaking through the limitation of traditional biochar that can only adsorb, it realizes the dual function of “transferring water during the day and locking in water at night”. Through the synergistic formation of three layers of biochar to form a through water bridge, water is absorbed and produced through multiple pathways at night. • The principle of "dual-purpose water and air pipe molecular sieve" is proposed for the first time: it realizes selective water and vapor transmission by utilizing the difference in molecular properties, and innovatively designs "day and night double drip irrigation", which completely solves the core pain point of "steam cannot get in and escapes", without the need for precise size control; • The principle of “local heat insulation buffer temperature control” is proposed for the first time: a special heat insulation buffer structure is set up. The heat insulation buffer structure is selected from any one of clay, organic material fabric, perlite particle filling layer, foamed concrete thin plate or foamed ceramic particle and fine sand mixture filling layer, with the thickness controlled at 1-5cm (preferably 3cm). This maintains the temperature gradient of the functional area, provides a stable environment for the directional flow and condensation of water vapor, and protects the core components, thus solving the defects of temperature gradient imbalance in the existing technology. • A “triple coupling” system is constructed for the first time: the three principles mentioned above are coordinated to form a closed loop of “temperature gradient drive + dual water production + full-area water locking”, which produces unexpected technical effects and significantly improves water use efficiency compared with existing technologies.

[0023] 2. Technological advantages (core practicality) • The principle is feasible: The core principle is based on molecular characteristics, biochar performance and temperature gradient effect, and has been experimentally verified to be effective, with no technical obstacles. • Cost adaptation: The size and material requirements of non-core components are reduced, and low-cost porous materials are used for local heat insulation buffer layers. The heat insulation and seepage prevention water collection tank only needs to meet the requirements of "corrosion resistance and root damage prevention", which is suitable for the low-cost needs of agricultural and desert scenarios. • Extremely low energy consumption: The refrigeration system only requires macroscopic cooling and utilizes surplus electricity from the national power grid, resulting in low operating costs; • Wide range of applications: Suitable for various arid / semi-arid regions, with a core structure that is highly weather-resistant and can adapt to extreme temperature environments, requiring no complex maintenance.

[0024] 3. Differences from existing technologies Existing technologies rely on single biochar adsorption or single drip irrigation, lack the design principle of "day and night coordinated water production", do not have a dedicated heat insulation buffer structure, cannot maintain the temperature gradient, do not solve the problem of selective water vapor transport, and have high energy consumption and low water utilization rate. This invention uses "triple coupling" as its core principle to achieve dual water production and dual water retention driven by temperature gradient, solving the core defects of existing technologies; it weakens non-core details, focuses on principle innovation, and has been experimentally verified to be effective, fully meeting the "novelty, inventiveness and utility" requirements for patent authorization.

Claims

1. A biochar respiring underground water storage and cooling system driven by solar-wind hybrid power generation, characterized in that, It includes a temperature difference breathing zone (5), a water supply and ventilation pipe (1), a refrigeration system, a water collection and energy storage structure, a modified biochar system, control components, a power unit (10), and a wind-solar hybrid power generation device (9), wherein: The temperature difference breathing zone (5) is a layered porous media composite layer, containing two sub-regions: the cultivation adaptation zone (20) and the local heat insulation buffer layer zone (19). The core function is achieved through the internal thin-layer modified biochar (18): during the day, it forms capillary water bridges to conduct water vapor, and at night, it recovers the evaporated water vapor below to prevent loss. The water-transporting and ventilation pipe (1) is the core drip irrigation component, which only undertakes the functions of drip irrigation and venting. It is set between the lower surface of the temperature difference breathing zone (5) and the upper surface of the relatively water-proof zone (16), and is limited to the corresponding areas of the relatively high temperature planting zone (14) and the relatively low temperature water-rich zone (15). The sand layer above the pipe serves as a molecular sieve. It utilizes the difference in characteristics between steam molecules (72%-74% the size of air molecules and polar) and air molecules (non-polar), as well as the sliding penetration characteristics of steam molecules accounting for more than 50%, to achieve selective water vapor transmission: During daytime ventilation, a large amount of steam molecules infiltrate downwards, and air molecules are discharged through the vent holes (clearing the channel obstacles). Water vapor accumulates and condenses around the pipe to form daytime drip irrigation. At night, cold air is introduced for cooling, and the temperature around the pipe drops first. Water vapor directionally accumulates and condenses to form nighttime drip irrigation, solving the core technical pain point of steam "not being able to enter and running out". The water-transporting and ventilation pipe (1) is made of corrosion-resistant and durable materials to meet the requirements of long-term underground use. The refrigeration system is the foundation of the technology, including refrigeration pipe (3), refrigeration main pipe (7) and refrigeration machine (8). The refrigeration pipe (3) is buried under the condenser plate (13) and is connected to the refrigeration machine (8) through the refrigeration main pipe (7) to form a closed loop. It uses an environmentally friendly refrigerant and only needs to achieve a macroscopic cooling effect at night to ensure water vapor condensation. The specific power and size are not limited. The subsequent special patent will protect it separately. The water collection and energy storage structure includes an insulated and seepage-proof water collection tank (4), a relatively water-proof zone (16), a condensation zone (12), a seepage-proof and heat-insulating water collection plate (2), a capillary water guide channel and a saturated layer (25), forming an integrated structure of "condensation-water guide-water storage-heat insulation-buffering"; among which, the insulated and seepage-proof water collection tank (4) takes "water storage, corrosion resistance and prevention of plant root damage" as its core requirements, and is made of environmentally friendly and corrosion-resistant materials. Excess stored water can be pumped back to the water delivery and ventilation pipe (1) by an independent water pump (29) to achieve secondary drip irrigation; The modified biochar system serves as the core for directional water transport, comprising a modified biochar layer (6), a thin-layer modified biochar (18), and a biochar coating (26). These three layers are interconnected through pores to form a continuous capillary water bridge network. The capillary suction is ≥0.02MPa, the porosity of the modified biochar is ≥65%, and the specific surface area is ≥500m² / g, ensuring the stable formation of the water bridges. Any of the following modification methods can be used (highlighting the core of material modification): (1) A polydopamine coating (PDA) is formed by grafting sulfonic acid groups or synergistic grafting of sulfonic acid groups and quaternary ammonium groups. The sulfonic acid group grafting uses a 5% sulfonating agent (such as concentrated sulfuric acid) and reacts at 60℃ for 2 hours with a solid-liquid ratio of 1:10 (g / mL). The synergistic grafting of sulfonic acid groups and quaternary ammonium groups is carried out by sulfonating under the above conditions and then reacting with a 3% hexadecyltrimethylammonium bromide solution (ethanol-water volume ratio 1:1) at 50℃ for 1.5 hours. The PDA coating is prepared by soaking in Tris-HCl buffer (pH=8.5) at room temperature for 12 hours with a dopamine hydrochloride concentration of 2 mg / mL and a coating thickness of 5-10 μm. (2) After the fuming nitric acid is oxidized in the gas phase, it is coated with TiO2 sol-gel to form a carboxyl-TiO2 composite adsorption layer; the fuming nitric acid gas phase oxidation is carried out at 40℃ for 30 min, and then washed with water until neutral and dried; the TiO2 sol-gel coating is tetrabutyl titanate: ethanol: water = 1:4:0.5 (volume ratio), pH=3, soaked in biochar and dried at 50℃, and calcined at 450℃ for 2 h; (3) 6% industrial magnesium salt, 8% straw activated carbon powder and 3% diatomaceous earth were added according to the mass of biochar. The mixture was prepared by drum mixing (300 r / min, 30 min), fluidized bed film formation (inlet air temperature 80℃, outlet air temperature 45℃, film thickness 1-2 mm), and natural curing (curing for 24 h at room temperature 20-25℃ and humidity 60%). The modified biochar system is coupled with the water conveying and ventilation pipe (1) to achieve day and night coordination: during the day, water is produced through the layered cooperation of biochar, and at night, water is stored, absorbed and locked in by biochar; the modified biochar layer (6) is located above the condenser plate (13), with low temperature and high condensation power, ensuring that water vapor is quickly adsorbed to form a water bridge; the biochar coating layer (26) is laid above the relatively water-proof area (16) to achieve full harvesting of water vapor; The control components include a dual-point temperature sensor (17), a vapor pressure sensor (21), a soil moisture sensor, a controller, and a linkage actuator. The core implementation module coordinates monitoring to meet future cold energy leakage monitoring needs, and the specific control accuracy does not need to be limited. The power unit (10) includes an independent fan (28) and an independent water pump (29), which are connected to the water supply and ventilation pipe (1) respectively to realize exhaust / cool air delivery and drip irrigation water supply (including water collection tank residual water recovery). The core of the wind-solar hybrid power generation device (9) is used to consume the low-priced photovoltaic / wind power and abandoned power from the State Grid, and to supply power to the system. There is no need to consider energy storage. It is electrically connected to the control components, the cooling system, and the power unit (10).

2. A method for using a biochar respiring underground water storage and cooling system driven by solar-wind hybrid power generation, characterized in that... Includes the following steps: (1) System deployment: Deploy in the order of "laying the bottom foundation → laying the water collection and condensation layer → laying the functional layer and pipeline → installing the control components → calibrating the corresponding zones". The core is to ensure the positional adaptation and connection sealing of the modified biochar system and the water supply and ventilation pipe (1). Non-core components only need to meet the basic functions. (2) Day and night coordinated operation (core principle embodiment): During the day: Solar energy forms high-pressure water vapor, which is transferred to produce water through the layered cooperation of the modified biochar system - thin-layer modified biochar (18), modified biochar layer (6), and biochar coating layer (26) form a through water bridge in sequence, which directionally conducts water vapor to the water collection and energy storage structure; at the same time, the water conveyance and ventilation pipe (1) captures water vapor through the molecular sieve effect of sand layer, and condenses it to achieve daytime drip irrigation; Nighttime: Under low temperature conditions, the biochar system achieves full-area water locking and water production - deep biochar continues to store and produce water, shallow biochar (the bottom layer of the surface) absorbs water from the air and the lower layer, and the surface biochar directly replenishes water from the air; the refrigeration system and the independent fan (28) are linked to start, and the water supply and ventilation pipe (1) introduces cold air, which condenses to achieve nighttime drip irrigation; the thin-layer modified biochar (18) recovers the water vapor evaporated below to prevent loss; Irrigation trigger: When the soil moisture content in the relatively high temperature planting area (14) reaches the set threshold, the independent water pump (29) is started for precision irrigation (including the recycling of residual water in the collection tank). (3) Operation and maintenance monitoring: Regularly monitor the status of core components and water utilization efficiency, focus on monitoring cold energy leakage, and increase the number of monitoring after extreme weather.

3. The system according to claim 1, characterized in that, The surface layer of the temperature difference breathing zone (5) is a dual-function layer of "pore water outflow - small amount of water evaporation", and the lower layer is a confluence-water transfer bridging layer (with a thin layer of modified biochar (18) laid throughout the area); the lower layer of the local heat insulation buffer layer area (19) is equipped with a heat insulation buffer structure, while the lower layer of the cultivation adaptation zone (20) does not have this structure.

4. The system according to claim 1, characterized in that, The inner wall of the water supply and ventilation pipe (1) is modified with hydrophilicity, and the outer wall is fitted with a sand-proof filter screen (22). The pipe wall has independent drip irrigation holes and vent holes to ensure water vapor condensation and air discharge.

5. The system according to claim 1, characterized in that, The independent fan (28) is connected to the exhaust flange of the water supply and ventilation pipe (1), and the independent water pump (29) is connected to the water supply end of the water supply and ventilation pipe (1) by thread. The connection is sealed with weather-resistant sealant.

6. The system according to claim 1, characterized in that, The refrigeration pipe (3) is a copper coil, aluminum coil or low-temperature resistant plastic pipe, which is buried under the condenser plate (13); the refrigeration unit (8) and the independent fan (28) start synchronously at night, and the cold air is blown into the planting area and the water-rich area through the exhaust hole of the water supply and ventilation pipe (1); the condensation area (12) is formed by the condenser plate (13) and the refrigeration pipe (3), and the relative water-proof area (16) is made of cement-based penetrating crystalline waterproof material.

7. The system according to claim 1, characterized in that, A support structure is provided between the modified biochar layer (6) and the condenser plate (13). The support structure is an organic mesh (11), a grid or non-woven fabric, made of polypropylene, polyester or glass fiber, with a porosity ≥70%, to ensure that the pores of the biochar layer are interconnected.

8. The system according to claim 1, characterized in that, In the water collection and energy storage structure, the seepage-proof and heat-insulating water collection plate (2) is set below the condensation zone (12); the capillary water guide channel is continuously arranged around the water conveyance and ventilation pipe (1) and connected to the relative water-proof zone (16); the water-saturated layer (25) is laid with a mixture of gravel and clay / bentonite to meet the buffering water release requirements.

9. The system according to claim 1, characterized in that, The dual-point temperature sensor (17) is installed on the ground surface and above the condenser plate (13), the steam pressure sensor (21) is installed near the water supply and ventilation pipe (1), and the soil moisture sensor is installed in the soil of the relatively high temperature planting area (14) and the relatively low temperature water-rich area (15). The linkage actuator includes an electromagnetic relay, an electric valve and a frequency converter to realize the start and stop regulation of the core components.

10. The system according to claim 1, characterized in that, The wind-solar hybrid power generation device (9) includes photovoltaic panels and wind turbines. Its core function is to connect to the national grid for surplus photovoltaic / wind power without relying on its own energy storage.

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