A gradient trigger and resource cycle-based urban agglomeration road tree pool composite landscape system

Abstract

This invention relates to a composite landscape system for tree pits along urban roads based on gradient triggering and resource recycling. It includes a sidewalk paved with interlocking pavers and ecologically recycled tree pit units spaced at intervals along the sidewalk near the roadway. Prefabricated functional drainage grid modules are installed in the gaps between the pavers. Adjacent functional drainage grid modules are combined to form a complete grid drainage system. Drainage channels within each catchment area converge into a main drainage pipe and are introduced into a storage tank via a sedimentation tank and filtration layer. A water source heat pump unit is installed in the equipment well. This invention constructs an intelligent model of "passive-triggered anti-icing—active dual-heat-source synergistic snow melting—ecological recycling of rainwater and snowmelt," achieving the goal of ensuring safe passage on sidewalks throughout winter while rapidly, efficiently, and energy-savingly melting snow and ice and collecting meltwater under conditions of initial snowfall, continuous snowfall, and extreme low temperatures.

Description

Technical Field

[0001] This invention relates to the field of urban and rural infrastructure and ecological engineering, specifically to an intelligent and modular pedestrian tree pit composite system suitable for areas with winter snowfall, which combines efficient snow melting, rainwater and snowmelt collection, ecological irrigation and energy saving. Background Technology

[0002] In vast northern regions, winter snowfall is frequent and prolonged. Traditional sidewalk snow removal methods primarily rely on manual sweeping and mechanical shoveling, which suffer from significant lag in response, often only commencing work after snow has accumulated or even compacted. This delayed removal is not only inefficient and costly but also fails to achieve thorough removal, frequently leaving thin layers of ice or compacted snow on the road surface, making sidewalks slippery and posing a serious threat to pedestrian safety, especially the elderly and children. Furthermore, the large-scale use of chloride-based de-icing agents corrodes road infrastructure and vehicle chassis, and seeps into the soil or enters pipe networks with the melted snow, causing long-term pollution to roadside vegetation, groundwater, and sewage treatment systems, resulting in substantial ecological costs. These problems demonstrate that existing conventional methods are insufficient to fundamentally guarantee the safety, accessibility, and normal use of sidewalks during winter.

[0003] Meanwhile, urban and rural areas, especially in northern regions, generally face two core contradictions in sustainable development: First, the contradiction between water scarcity and the need for green space maintenance. The maintenance of sidewalks, roadside trees, and green belts relies on precious municipal water or groundwater, which is costly and exacerbates water resource pressure. Rainwater runoff and snowmelt in winter, which could serve as supplementary water sources, are mostly discharged directly without being utilized as resources. Second, the contradiction between the urgent need for safe operation of urban infrastructure and high energy consumption. To ensure the operation of facilities, active de-icing technologies such as electric heating snow melting have begun to be used, but their continuous operation depends on direct power supply from the grid, resulting in extremely high energy consumption. Large-scale promotion will significantly increase the energy burden, which runs counter to the goal of energy conservation and emission reduction.

[0004] To address the above challenges, current research and practice mainly revolve around the following relatively isolated technical approaches: First, developing environmentally friendly snow-melting agents to reduce corrosiveness and ecotoxicity; however, large-scale use still results in pollution and prevents the recycling of surface runoff. Second, developing electrothermal snow-melting technology; however, high operating costs often limit its widespread adoption. Third, exploring the use of solar and geothermal energy for snow melting to reduce operating costs; however, the system stability and climate dependence (such as sunlight intensity and installation location) are strong, limiting its application. Fourth, rainwater harvesting and utilization; however, this is limited to rainfall, and winter snowfall and snowmelt water cannot be collected and treated. Overall, existing technical approaches lack an integrated and innovative solution that can simultaneously and systematically address the four major goals of "instant and safe snow (ice) removal, ecological environment protection, water resource recycling, and significant reduction in operating energy consumption."

[0005] Therefore, there is an urgent need in this field for a breakthrough infrastructure construction and operation solution. This solution can proactively, promptly, and thoroughly eliminate the hazards of ice and snow on sidewalks, avoid pollution from de-icing agents, significantly reduce the energy consumption of the snow melting process itself, and collect and purify road runoff, converting it into a reliable source of irrigation water for greening, thus alleviating urban water pressure. Summary of the Invention

[0006] This invention addresses the problem of snow and ice accumulation on pedestrian walkways in winter by constructing an intelligent, modularly laid pedestrian walkway-tree pit composite landscape system. Through a gradient-triggered operation mode of "passive-triggered anti-icing—active dual-heat-source synergistic snow melting—ecological recycling of rainwater and snowmelt," it achieves the goal of ensuring safe passage on pedestrian walkways throughout winter while rapidly, efficiently, and energy-savingly melting snow and ice during initial snowfall, continuous snowfall, and extreme low temperatures, and collecting meltwater. This significantly reduces snow melting energy consumption, avoids snow melting agent pollution, and utilizes rainwater and meltwater resources, realizing the green, low-carbon, and intelligent operation of urban infrastructure.

[0007] To achieve the above objectives, the present invention provides a composite landscape system for urban agglomeration road tree pits based on gradient triggering and resource recycling, including a sidewalk paved with several paving bricks and ecological recycling tree pit units spaced apart along the sidewalk near the roadway. The gaps between the paving bricks are provided with prefabricated functional drainage grid modules, and adjacent functional drainage grid modules are combined to form a complete grid drainage system.

[0008] The floor tile comprises, from top to bottom, a surface layer, a heating layer, a thermal insulation layer, and a waterproof structural base layer. The heating layer is divided into a carbon fiber heating structure and a hydrothermal structure by an S-shaped concrete isolation barrier. Carbon fiber heating wires and hydrothermal coils are laid on both sides of the barrier, and a far-infrared directional radiation coating is applied to the concrete surface. The carbon fiber heating wires and hydrothermal coils have openings at the entrances and exits on both sides of the tile. The thermal insulation layer is made of vacuum insulation board and extruded polystyrene composite. The waterproof structural base layer comprises, from top to bottom, a structural concrete layer formed by pouring fiber-reinforced polymer waterproof concrete, an interface treatment layer formed by applying an interface agent after the concrete has set, and a bottom waterproof coating formed by applying a high-performance waterproof coating to the bottom and sides of the concrete.

[0009] The functional drainage grid module is a composite structure of an upper drainage grid and a lower drainage channel. The drainage grid includes a far-infrared ceramic frame surrounding each floor tile, an embedded brush strip set at the edge of the frame towards the center of the floor tile gap, and a dividing support strip set in the middle of the frame. The drainage channel is a wide-mouth U-shaped structure.

[0010] The ecological cycle tree pit unit includes, from top to bottom, street trees, tree pit grates, planting soil layer, filter layer, permeable geotextile, water storage tank, and impermeable subbase. The water storage tank is equipped with water distributors installed at the top and bottom. Hot water enters and exits from the top of the water storage tank, while cold water enters and exits from the bottom. The purified water from the water storage tank is used to irrigate the street trees through a low-pressure drip irrigation pipeline.

[0011] The drainage channels in each water collection area are uniformly connected to the main drainage pipe and introduced into the water storage tank through the sedimentation tank and filter layer. An equipment well is set under the pedestrian street light. The equipment well is equipped with a water source heat pump unit. The evaporator side of the water source heat pump unit is connected to the heat extraction side circulation pump and the water distribution pipe circuit of the water storage tank. The condenser side of the water source heat pump unit is connected to the heating side circulation pump and the water heating coil circuit in the paving bricks. When the water temperature in the storage tank is >25℃, the first-level heat release mode is activated, directly drawing water from the hot water area of ​​the storage tank and heating the water heating coils via a plate heat exchanger; when the water temperature in the storage tank is between 15~25℃, the second-level heat release mode is activated, starting the water source heat pump unit to extract heat from the storage tank and provide heating; when the water temperature in the storage tank is ≤15℃, the third-level heat release mode is activated, with the water source heat pump unit operating at full power.

[0012] Preferably, the surface layer is configured as a flat-topped pyramid shape, with the square at the very center of the top having a side length of 1 / 5 to 1 / 4 of the side length of the floor tile, a slope of 1.5% to 2.5%, and a striped texture with a roughness Ra of 0.8 to 1.5 mm that is consistent with the slope direction is formed on the surface layer; the phase change-snow melting composite functional aggregate is a core-shell structure particle with a particle size of 3.0 to 8.0 mm; the phase change-snow melting composite functional aggregate uses a porous material with a bimodal pore size distribution as a carrier, employs a homogeneous composite of potassium acetate and glycerol, and selects phase change paraffin wax with a phase change temperature of 1 to 4 °C to fill the interconnected micropores and macropore entrances inside the carrier through stepwise vacuum impregnation.

[0013] The porous material has the following pore structure: internal macropores with an average pore diameter of 10–30 μm and a porosity of 40%–50%; and surface interconnected micropores with an average pore diameter of 0.5–2 μm and a porosity of 20%–30%.

[0014] Preferably, the preparation steps of the phase change-snow melting composite functional aggregate include: Step (1), loading de-icing agent: The carrier is natural / synthetic zeolite, mesoporous silica balls or custom porous ceramic; the dried carrier particles are loaded into a vacuum impregnation tank, sealed tightly, and the vacuum pump is started to evacuate the tank to -0.08~-0.09MPa and maintain this vacuum for 45~60 minutes; the potassium acetate-glycerol solution with a mass ratio of 1:(0.5~2) is heated to 50~60℃, and while maintaining the vacuum, the potassium acetate-glycerol solution preheated to 50~60℃ is drawn into the impregnation tank through the feed valve until the carrier particles are completely submerged. The vacuum is maintained and impregnation is continued for 1~2 hours; after impregnation, the carrier particles are taken out of the solution and placed in a sieve or filter basket to drain naturally for 10~20 minutes. Then the particles are transferred to a centrifuge and centrifuged at 300~500rpm for 0.5~1 minutes. After centrifugation, the particles are thoroughly dried. Step (2), selective filling with paraffin wax: Select phase change paraffin wax and heat it to 10~15℃ above the melting point until it is completely melted into a liquid state. Preheat the carrier particles loaded with de-icing agent after drying in step (1) to 5~10℃ above the melting point of the molten phase change paraffin wax. Put the preheated carrier particles into a vacuum impregnation tank, seal it tightly, start the vacuum pump, and evacuate the vacuum degree in the tank to -0.06~-0.07MPa. Maintain this vacuum degree for evacuation for 30~45 minutes. While maintaining the vacuum, suck the molten phase change paraffin wax into the impregnation tank through the feed valve until the carrier particles are completely submerged. Keep the vacuum degree unchanged and continue impregnation for 4~6 hours. After impregnation is completed, slowly restore the atmospheric pressure and slowly cool the carrier particles. Step (3), post-treatment and cleaning: After the wax is cooled, perform gentle centrifugation or surface scrubbing to remove excess paraffin adhering to the large pore openings; Step (4), encapsulation and protection: fluidized bed coating process is adopted, and bottom spray fluidized bed coating method is used. Ethyl cellulose is used as the wall material to coat the surface of the particles to form an encapsulation and protection layer. The concentration of the coating solution is 4-4.5% ethyl cellulose-ethanol solution. After four stages of preheating-coating-drying-cooling, the encapsulation layer thickness reaches 5-10μm, and the final phase change-snow melting composite functional aggregate is obtained.

[0015] Preferably, the hydrothermal structure uses PE-Xa pipelines with a diameter of 15-20mm to be laid in an S-shape on one side of the barrier and fixed with U-shaped clips, and the surface of the coil is covered with aluminum foil tape; the sidewalk water collection unit is divided into several independent heating zones according to the single loop length ≤80m, and each heating zone is equipped with an independent water supply and return loop; The carbon fiber heating structure consists of carbon fiber heating wires with silicone rubber insulation arranged in an S-shape or grid pattern. The outer diameter of the carbon fiber heating wires is 3.0 to 4.0 mm. They are embedded in high thermal conductivity cement mortar at intervals of 80 to 120 mm to form the main heating surface. The thickness is 10 to 15 mm, so that the distance from the center of the carbon fiber heating wire to the surface of the brick is 20 to 40 mm.

[0016] Preferably, the brush belt adopts a composite bristle bundle design, all bristles are black, all are flat, and the bristles are tilted downwards at 10°, with the length gradually increasing from the outer layer to the inner layer; the outer layer of the brush belt is a wavy steel wire with a diameter of 0.5~0.8mm; the middle layer of the brush belt is a high-elasticity nylon material with a diameter of 0.3~0.5mm, and the nylon material is made by uniformly dispersing 10~15% far-infrared ceramic powder and 3~5% graphene powder in a polymer nylon matrix; the inner layer of the brush belt is a low-temperature resistant polyester soft bristle with a diameter of 0.1~0.3mm.

[0017] Preferably, the dividing support strip is generally a flat-topped tower shape that is narrower at the top and wider at the bottom, with thin, straight drain outlets on both sides that are wider at the top and narrower at the bottom; the dividing support strip is made of far-infrared ceramic material and has built-in heating wires; the far-infrared ceramic material contains 70-80% by mass of kaolin, feldspar, and quartz as basic ceramic components, 10-15% by mass of a mixture of tourmaline, zirconium oxide, and silicon carbide as far-infrared radiating material, 5-10% by mass of carbon fiber powder as conductive heating component, and 2-5% by mass of alumina short fibers to enhance ceramic strength. The above components are prepared by compression molding followed by high-temperature co-firing process.

[0018] Preferably, the sedimentation tank is inlet water from the bottom and supernatant overflows from the top, with a triangular weir collecting water at the top outlet; the filter layer is a filter media box consisting of layers of zeolite, biochar made from agricultural and forestry waste, and coarse quartz sand laid from top to bottom, with waterproof geotextile laid between each layer, a water distribution system at the top, and a perforated water collection pipe at the bottom of the filter layer, wrapped with geotextile, with the end of the water collection pipe connected to the water storage tank through a water seal bend.

[0019] Preferably, the water storage tank has a first water distribution pipe with a perforated flow equalization plate installed 50-80mm from the bottom and a second water distribution pipe with a perforated flow equalization plate installed 50-80mm from the top. When the inlet water is cold water, the water is directly introduced into the bottom layer of the water storage tank through the first water distribution pipe. When the inlet water is hot water, the water is introduced into the upper layer of the water storage tank through the second water distribution pipe. The height of the second water distribution pipe is controlled by a float. The water outlet of the water storage tank adopts a zoned outlet, with hot water exiting from the upper part of the water storage tank and cold water exiting from the bottom of the water storage tank. The middle of the water storage tank is provided with two layers of partially sealed HDPE insulation board, with a gap of 80-120mm between the two insulation boards, and the two insulation boards are open on opposite sides.

[0020] Preferably, when the hot water temperature is >25℃, the first-level heat release mode is activated and the water source heat pump unit is shut down; when the hot water temperature drops to 20℃, it automatically switches to the second-level heat release mode and starts the water source heat pump unit; when the water temperature in the storage tank drops to 12℃, it automatically enters the third-level heat release mode; when the water temperature in the storage tank is <5℃, the water source heat pump unit is forcibly shut down, and only the carbon fiber heating wire is activated to melt snow.

[0021] Based on the above technical solution, the advantages of the present invention are: This invention, through the deep integration of material innovation, structural optimization, intelligent control, and ecological design, constructs a composite landscape system and intelligent implementation plan for pedestrian walkways with tree pits, integrating passive anti-icing, active snow melting, cross-seasonal energy storage, ecological circulation, and summer cooling. It achieves a leapfrog improvement over existing technologies in snow melting effect, energy conservation, environmental protection, and intelligent operation and maintenance, providing a brand-new technical solution for urban infrastructure construction in cold regions. This invention upgrades pedestrian walkways from simple "hardened paving" to "ecological infrastructure," realizing the synergistic recycling of rainwater, snowmelt water, and thermal energy.

[0022] The gradient snow melting strategy of this invention, which is based on "passive triggering and active heating guarantee", can automatically match the optimal heating strategy according to the snow conditions, maximize energy saving while ensuring the snow melting effect, and reduce the operating energy consumption by more than 60% compared with the traditional continuous heating scheme.

[0023] This invention constructs a cross-seasonal energy-saving thermal storage mode for summer storage and winter use, intelligently switching between the "rapid infiltration and regulation" mode in summer and autumn and the "anti-freeze storage" mode in winter and spring. It adapts to the characteristics of cold climate, realizes the annual cycle optimization of water resources, and can intelligently manage precipitation resources. It realizes the seasonal allocation and resource utilization of heat, plays a role in reducing the heat island effect in summer and melting snow and preventing ice in winter, and achieves energy conservation, consumption reduction and resource recycling. Attached Figure Description

[0024] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 A schematic plan of a road-tree-pit composite landscape system in an urban agglomeration; Figure 2 A schematic diagram of a tree pit composite landscape system along urban roads; Figure 3 This is a top-down view of the floor tiles; Figure 4 This is a schematic diagram of a cross-section of the floor tiles; Figure 5 This is a schematic diagram of the heating layer structure of the floor tiles; Figure 6This is a schematic diagram of a drainage grating structure; Figure 7 This is a schematic cross-sectional view of a functional drainage grid module; Figure 8 This is a schematic diagram of the water distributor inside the reservoir. Detailed Implementation

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] This invention provides a composite landscape system for urban roadside tree pits based on gradient triggering and resource recycling, mainly including intelligent snow-melting pavement units, functional drainage grid modules, ecological recycling tree pit units, water storage and purification modules, and a dual-heat source heating system, etc. Figures 1-8 As shown, a preferred embodiment of the present invention is illustrated.

[0027] The urban agglomeration road tree pit composite landscape system of the present invention includes a sidewalk paved with several paving bricks 1 and ecological cycle tree pit units 25 arranged at intervals along the side of the sidewalk near the roadway. The gaps between the paving bricks 1 are provided with prefabricated functional drainage grid modules, and adjacent functional drainage grid modules are combined to form a complete grid drainage system.

[0028] The floor tile 1 comprises, from top to bottom, a surface layer 2, a heating layer 3, a thermal insulation layer 4, and a waterproof structural base layer 5. The heating layer 3 is provided with an S-shaped concrete isolation barrier 6 to divide the tile body into a carbon fiber heating structure and a hydrothermal structure. Carbon fiber heating wires 7 and hydrothermal coils 8 are laid on both sides of the barrier 6, and a far-infrared directional radiation coating is applied to the concrete surface. The carbon fiber heating wires 7 and hydrothermal coils 8 have openings at the entrances and exits on both sides of the tile body. The thermal insulation layer 4 is made of vacuum insulation board and extruded polystyrene composite. The waterproof structural base layer 5 comprises, from top to bottom, a structural concrete layer formed by pouring fiber-reinforced polymer waterproof concrete, an interface treatment layer formed by applying an interface agent after the concrete has set, and a bottom waterproof coating formed by applying a high-performance waterproof coating to the bottom and sides of the concrete.

[0029] Furthermore, the functional drainage grid module is a composite structure of an upper drainage grid and a lower drainage trough. The drainage grid includes a far-infrared ceramic frame 18 surrounding each floor tile 1, an embedded brush strip 19 set at the edge of the frame 18 towards the center of the gap in the floor tile 1, and a dividing support strip 20 set in the middle of the frame 18. The drainage trough 21 is a wide-mouth U-shaped structure.

[0030] The ecological cycle tree pit unit 25 includes, from top to bottom, street trees 10, tree pit grates, planting soil layer 11, filter layer 17, permeable geotextile 12, water storage tank 13, and impermeable subbase 14. The water storage tank 13 is equipped with water distributors installed independently at the top and bottom. Hot water enters and exits from the upper part of the water storage tank 13, while cold water enters and exits from the bottom of the water storage tank 13. The purified water from the water storage tank 13 is used to irrigate the street trees 10 through a low-pressure drip irrigation pipeline.

[0031] Furthermore, the drainage channels 21 in each water collection area are uniformly connected to the main drainage pipe 15 and introduced into the water storage tank 13 through the sedimentation tank 16 and the filter layer 17. An equipment well is set under the pedestrian street light 9. The equipment well is equipped with a water source heat pump unit. The evaporator side of the water source heat pump unit is connected to the heat extraction side circulation pump and the water distributor pipeline circuit of the water storage tank 13. The condenser side of the water source heat pump unit is connected to the heating side circulation pump and the water heating coil 8 circuit in the floor tile 1.

[0032] When the water temperature in reservoir 13 is >25℃, the first-level heat release mode is activated, directly drawing water from the hot water zone of reservoir 13 and heating the water heating coil 8 via the plate heat exchanger; when the water temperature in reservoir 13 is between 15~25℃, the second-level heat release mode is activated, starting the water source heat pump unit to extract heat from reservoir 13 and raise the temperature for heating; when the water temperature in reservoir 13 is ≤15℃, the third-level heat release mode is activated, with the water source heat pump unit operating at full power.

[0033] The sidewalk is constructed by piecing together several paving brick units, with ecologically recyclable tree pit units spaced at intervals on the side closest to the roadway. The gaps between the paving bricks are fitted with prefabricated functional drainage grid modules.

[0034] The sidewalk width is designed to be 2.5~4m. The ecological tree pits are square structures with a side length of 1~1.5m, and one tree pit is set every 8~12m along the sidewalk closest to the roadway.

[0035] like Figure 1 As shown, the line connecting the midpoint of the vertical distance between two adjacent tree pits to the shortest distance between the two edges of the sidewalk is the area dividing line A. The area between two adjacent area dividing lines A is the range within the area that the tree pits and the water collection and purification modules below them are responsible for collecting and treating. If the dividing line crosses the paving stones, the area of ​​that paving stone belongs to the side that occupies the larger area.

[0036] Intelligent snow melting tile unit like Figure 3 , Figure 4As shown, the floor tile 1 is a square with a side length of 250-400mm and a thickness of 100-135mm, and has a longitudinal four-layer composite structure; the surface layer 2 has a thickness of 15-25mm, the heating layer 3 has a thickness of 25-30mm, the thermal insulation layer 4 has a thickness of 20-30mm, and the waterproof structural base layer 5 has a thickness of 40-50mm.

[0037] The surface layer 2 is designed as a flat-topped pyramid shape, with the square at the very center of the top having a side length of 1 / 5 to 1 / 4 of the side length of the floor tile, and a slope of 1.5% to 2.5%. This allows runoff from the floor tile to flow evenly into the surrounding mesh gaps along the slope, forming a high-roughness stripe texture (Ra 0.8-1.5mm) on its surface in the direction of the slope. This texture serves multiple functions, including anti-slip, delaying icing, and guiding flow. The thickness is 15 to 25mm.

[0038] The material is prepared primarily using recycled construction waste aggregate, with 5%–10% by volume of phase change-snow melting composite functional aggregate. This phase change-snow melting composite functional aggregate is a core-shell structured particle with a particle size of 3.0–8.0 mm. This material is key to achieving passive, low-temperature triggered snow melting. The main characteristics of this aggregate are as follows: Carrier: Artificial zeolite or ceramsite with a bimodal pore size distribution is selected. Its macropores are used to store the active ingredients, and the interconnected micropores are used to fill the triggering medium.

[0039] Active ingredient: a homogeneous complex of potassium acetate and glycerin. Potassium acetate, as the main de-icing agent in this invention, has the advantages of being environmentally friendly and having high de-icing efficiency. Glycerin, as a solvent, can prevent potassium acetate from clogging pores at low temperatures by crystallization and provides auxiliary freezing point lowering and moisturizing effects. At the same time, it helps to form an anti-freezing liquid film on the brick surface after dissolution.

[0040] Triggering medium: Phase change paraffin with a phase change temperature precisely controlled between 1 and 4°C is selected. Through a stepwise vacuum impregnation process, it is preferentially filled into the interconnected micropores and macropore entrances inside the carrier.

[0041] The method for producing the phase change-snow melting composite functional aggregate is as follows: ① Carrier selection and design Select or prepare special porous materials with a "bimodal pore size distribution," such as natural / synthetic zeolites, mesoporous silica spheres, or custom porous ceramics. These materials require a well-defined pore structure: internal macropores (10–30 μm) for storage, with a porosity of 40%–50%; and surface interconnected micropores (0.5–2 μm) for wax filling. The macropores are connected to the outside environment through micropore channels, with a porosity of 20%–30%.

[0042] ② Process sequence and parameter control The step-by-step vacuum impregnation method of "deeply filling with solution first, then shallowly sealing with wax" is adopted. The process parameters of each step should be precisely controlled throughout the entire process.

[0043] Step 1 (Loading De-icing Agent): Load the dried carrier granules into a vacuum impregnation tank and seal it tightly. Start the vacuum pump and evacuate the tank to a vacuum level of -0.08 to -0.09 MPa (gauge pressure). Maintain this vacuum level for 45-60 minutes, observing the vacuum gauge reading to ensure it remains stable. If no obvious bubbles emerge from the carrier surface, it indicates that the air in the carrier pores has been fully expelled.

[0044] A potassium acetate-glycerol solution with a mass ratio of 1:(0.5-2) is heated to 50-60°C. The solution at this concentration and temperature has a low viscosity and high concentration. The low viscosity allows the solution to penetrate smoothly into the deepest pores of the carrier, while the high concentration ensures that there are sufficient effective de-icing agents in the pores to play a de-icing role after subsequent drying and crystallization.

[0045] While maintaining a vacuum, a potassium acetate-glycerol solution preheated to 50–60°C is drawn into the impregnation tank through the feed valve until the carrier particles are completely submerged. The vacuum level is maintained, and impregnation continues for 1–2 hours. Due to the solution's low viscosity and good fluidity, this short time is sufficient for the solution to fully penetrate the macropores and interconnected channels within the carrier.

[0046] After impregnation, the carrier particles are removed from the solution and placed in a sieve or filter basket to drain naturally for 10-20 minutes, allowing the surface liquid to drip off under gravity. The particles are then transferred to a centrifuge and centrifuged at 300-500 rpm for 0.5-1 minute to further remove residual surface liquid. The centrifugal force generated under these gentle centrifugation conditions (approximately 0.1-0.5 kPa) is much less than the capillary pressure within the macropores of the carrier (approximately 12 kPa), thus preventing the loss of effective components from the pores. After centrifugation, the particle surface is moist but not flowing, and it is ready for the drying process. Thorough drying allows the de-icing agent to crystallize and solidify in all pores.

[0047] Step 2 (Selective Paraffin Filling): Select paraffin with a phase transition temperature of 1-4℃ as the triggering medium. Heat the paraffin to 10-15℃ above its melting point (i.e., 15-20℃) to completely melt it into a liquid state, and maintain this temperature for later use.

[0048] The carrier particles loaded with de-icing agent, after the first step of drying, are preheated to a temperature slightly above the melting point of paraffin (approximately 5-10°C) to prevent the paraffin from instantly solidifying and clogging the pores when it comes into contact with the cold carrier.

[0049] The preheated carrier particles are loaded into a vacuum impregnation tank and sealed tightly. The vacuum pump is started, and the vacuum level inside the tank is evacuated to -0.06 to -0.07 MPa (gauge pressure). This vacuum level is maintained for 30-45 minutes to remove residual air from the surface of the carrier and the micropores.

[0050] While maintaining a vacuum, molten phase change paraffin is drawn into the impregnation tank through a feed valve until the carrier particles are completely submerged. The vacuum level is maintained, and impregnation continues for 4-6 hours. Due to the high viscosity of paraffin (10-30 mPa·s), it requires a relatively long time to slowly penetrate the surface micropores and interconnected channels. In this step, the molten phase change paraffin preferentially fills the micropore region with a pore size of 0.5-2 μm using capillary action, while having difficulty entering the internal macropores occupied by de-icing agent crystals, thus achieving selective filling of functional zones.

[0051] After impregnation, slowly restore normal pressure. Slowly cool the carrier particles to allow the paraffin to solidify completely.

[0052] Step 3 (Post-treatment and Removal): After the wax impregnation has cooled, perform gentle centrifugation or surface scrubbing. Remove excess paraffin adhering to the openings of the large pores, ensuring that the de-icing agent crystals within the large pore body are exposed behind the paraffin-controlled "valve" channels, rather than being directly sealed off.

[0053] Step 4 (Encapsulation and Protection): Using a fluidized bed coating process, ethyl cellulose is used as the wall material to coat the surface of the particles, forming an encapsulation and protection layer with a thickness of 5-10 μm, thus obtaining the final functional aggregate.

[0054] The fluidized bed coating process is completed using commercially available fluidized bed coating equipment. This equipment is an industrialized granulation and microparticle coating device, improved from pharmaceutical drying equipment. It integrates granulation, microparticle preparation, coating, and drying processes. Its working principle is based on the fluidized bed phenomenon and spray film formation technology, with core components including fluidized bed formation, spraying and film formation, and drying and solidification. Process parameters include drying rate, airflow velocity, and spray rate, and the particle fluidization trajectory is controlled through structures such as guide tubes and distribution plates.

[0055] Ethyl cellulose possesses semi-permeable membrane properties—allowing small molecules such as water and ions to permeate, but hindering the outflow of large paraffin molecules. It forms a continuous, dense polymer film on the surface of aggregate particles, creating a "core-shell" structure together with the carrier particles, enhancing the mechanical strength of the aggregate. This step prevents paraffin leakage from the carrier during repeated phase transitions, ensuring cycle stability. It also protects the functional units from damage during concrete mixing and vibration.

[0056] Intelligent triggering mechanism: Room temperature closed state (>4℃): Paraffin is in a liquid state, a "bound liquid" adsorbed by capillary action in the micropores, blocking the dissolution channels of the active ingredients. The particles are in a "dormant" state, and the active ingredients are hardly lost. The ethyl cellulose coating layer forms a second barrier from the outside to ensure no leakage. Potassium acetate-glycerol is doubly locked.

[0057] Low-temperature triggered state (≤0℃): When the ambient temperature drops below the phase transition point of paraffin, the paraffin solidifies. During this process, the paraffin undergoes volume shrinkage, but because it is confined within micropores, the stress generated by the shrinkage concentrates at the paraffin-pore wall and paraffin-de-icing agent crystal interface, leading to microcracks or debonding at the interface. Simultaneously, shrinkage may also create localized cavities within the pores. These effects work together to mechanically disrupt the physical blockages previously formed by the paraffin, opening or widening the dissolution channels for the de-icing agent from the storage macropores outwards. Simultaneously, the external coating allows moisture to penetrate into the particle interior, contacting and dissolving potassium acetate-glycerol.

[0058] In the leached state: After the channel is opened, road surface moisture or initial snow meltwater comes into contact with and dissolves the potassium acetate-glycerol complex. The released high-concentration solution forms an anti-icing film on the brick surface, achieving "self-melting of light snow." This physical triggering mechanism is reliable and reversible. To ensure effectiveness, at least 50 freeze-thaw cycles can be conducted to ensure that the triggering release efficiency decay rate is less than 10%.

[0059] Furthermore, the heating layer 3 is laid under the surface layer 2, and two heating modes are set: carbon fiber heating structure and hydrothermal structure.

[0060] like Figure 5 As shown, this layer is equipped with an S-shaped concrete isolation barrier 6, 22–25 mm high. With a wavelength of 1 / 3 to 1 / 2 the side length of the floor tile, barrier 6 divides the tile into two parts, left and right. Carbon fiber heating wires 7 and water-heating coils 8 are laid on both sides of barrier 6, respectively. A far-infrared directional radiation coating is applied to the concrete surface, causing most of the radiated heat to reflect upwards towards the road surface. The barrier 6 isolates the two structures, preventing heat loss caused by mutual heat absorption when they are turned on individually.

[0061] The hydrothermal structure uses 15-20mm diameter PE-Xa pipes laid in an S-shape along one side of the wall, secured with U-shaped clips. The surface of the hydrothermal coil 8 is covered with aluminum foil tape to enhance heat reflection. As a water circulation system, the inlet and outlet settings of the hydrothermal coil 8 need to consider both hydraulic balance and antifreeze requirements. The sidewalk is divided into several independent heating zones according to the water collection area, each zone having an independent supply and return water circuit. The length of a single circuit should be ≤80m. If the water collection area is too large, multiple circuits can be set as needed to ensure hydraulic balance. The main inlet and outlet pipes are covered with rubber and plastic insulation material with a thickness exceeding 50mm. The water pipes at the brick joints pass under the far-infrared ceramic support strip of the drainage module, providing heat supply and achieving antifreeze effect in winter.

[0062] The carbon fiber heating structure consists of carbon fiber heating wires 7 with silicone rubber insulation arranged in an S-shape or grid pattern. The outer diameter of the heating wires is 3.0~4.0mm, embedded in high thermal conductivity cement mortar at intervals of 80~120mm to form the main heating surface, with a thickness of 10~15mm. The distance from the center of the heating wire to the brick surface is kept between 20mm and 40mm to ensure heat transfer efficiency and reduce energy consumption. The overall structural parameters should ensure that the heat transferred to the brick surface reaches the required temperature and is evenly distributed to meet snow melting requirements.

[0063] With silicone rubber as the insulating layer and 12K or 24K carbon fiber heating wire as the heating core, it has balanced heating efficiency, good weather resistance, insulation, and compatibility with concrete substrate.

[0064] To ensure the accurate positioning and uniform spacing of the carbon fiber heating wire 7 during concrete pouring, it needs to be fixed: the carbon fiber heating wire 7 is fixed to the pre-laid fiberglass mesh with clips to form a standardized heating module; the modular design makes the spacing of the carbon fiber heating wire 7 precise and controllable, which is convenient for factory prefabrication and on-site installation; sufficient length is reserved at both ends of the carbon fiber heating wire 7 to facilitate electrical connection.

[0065] The carbon fiber heating wire 7 has a rated power of 150~250W / ㎡. It ensures effective snow melting within 2~3 hours at an ambient temperature of -5℃. The operating voltage can be selected as a 36V safety voltage according to project safety requirements. The carbon fiber heating wire 7 is connected in parallel to the zoned distribution box and is equipped with an independent leakage protection device. Specifically, the electrical system of the carbon fiber heating structure is as follows: (1) Zoned power supply: The sidewalk is divided into several independent power supply zones according to the water catchment area. Each zone is equipped with an independent power distribution circuit and leakage protection device to facilitate fault diagnosis and energy-saving control.

[0066] (2) Connection method: The connection between carbon fiber heating wires adopts waterproof quick-connect fittings, and the joints are protected by multiple layers: first, epoxy resin is potted, then heat shrink tubing is applied, and finally silicone rubber is used for sealing to ensure insulation safety in long-term water immersion environment. This connection method is convenient and quick, and facilitates modular and rapid installation.

[0067] (3) Grounding protection: The system is equipped with reliable grounding protection and is linked to the leakage protection switch of the equipment well connected to it to ensure personal safety.

[0068] (4) Antifreeze preheating: The antifreeze preheating function is considered in the system design, which can start the low temperature operation mode in advance in extreme low temperature environments to prevent the system from starting too slowly.

[0069] The thermal insulation layer 4 is made of vacuum insulation board and extruded polystyrene composite to ensure upward heat conduction. The thickness of the thermal insulation layer 4 is 20-30 mm, preferably 25 mm. An interface treatment layer (applying an interface agent) can be applied to the upper and lower surfaces of the thermal insulation layer 4 to enhance the adhesion with the heating layer and the waterproof structural base layer. The joints between the boards need to be completely sealed with sealant to ensure the thermal insulation effect.

[0070] To improve heat utilization efficiency, the thermal insulation layer 4 can significantly reduce heat loss to the lower structure and direct more heat to the road surface, thereby improving ice melting efficiency. According to theoretical calculations, setting the thermal insulation layer 4 can increase the ice melting rate by 25-50%, shorten the snow melting time, reduce ineffective heat loss, and achieve energy-saving operation.

[0071] The waterproof structural base layer 5 is the lowest load-bearing and protective unit of this system, undertaking a dual core mission: on the one hand, it provides stable mechanical support for the upper functional layers (insulation layer, heating layer, and surface layer); on the other hand, it serves as the "last line of defense" for electrical safety, preventing moisture from penetrating to the roadbed and ensuring the insulation safety of the heating system. Through material blending and structural optimization, it achieves multi-functional synergy in terms of load-bearing capacity, waterproofing, and durability.

[0072] Fiber-reinforced polymer waterproof concrete, its material composition is: silicate cement (PO 42.5 and above) 350~400kg / m³ 3 Fly ash (Grade I or II) 80~120kg / m³ 3 Slag powder (S95 grade) 80~120kg / m³ 3 Medium sand 600~700kg / m³ 3 5~20mm continuously graded crushed stone 1100~1200kg / m³ 3 Polypropylene fiber 0.9~1.2kg / m 3 Acrylic ester copolymer emulsion (50% solid content) 30~50kg / m 3 Polycarboxylate superplasticizer 3~5kg / m3 Organosilane waterproofing agent 8~12kg / m 3 Water 160-180 kg / m 3 .

[0073] The production method is as follows: First, dry-mix the aggregate and fiber evenly, then add the cementitious material and dry-mix again, and finally add the liquid component and mix to form concrete. After pouring and molding, vibrate to compact, and cure for 28 days. After the concrete has set, sandblast the bottom surface to remove laitance, then apply a high-penetration epoxy primer (0.4 kg / m²), and after drying, apply a polyurea intermediate coat and lay down a polyester non-woven fabric (1.2 kg / m²). 2 Finally, apply the topcoat (0.4 kg / m²), with a total dry film thickness ≥ 1.2 mm.

[0074] Principles of mix design for fiber-reinforced polymer waterproof concrete: Low water-cement ratio: The water-cement ratio is controlled between 0.35 and 0.40 to ensure high concrete density and low porosity; Mineral admixture compounding: The compounding of fly ash and slag powder can produce a "synergistic effect", which can significantly improve the microstructure of concrete and enhance its impermeability. Fiber reinforcement: The incorporation of polypropylene fibers can effectively inhibit plastic shrinkage cracks in concrete and reduce the formation of through-holes. Polymer modification: During the cement hydration process, polymer emulsions form a polymer network that fills capillary channels, significantly improving the impermeability grade.

[0075] The structural layered construction from top to bottom includes: structural concrete layer: approximately 40-45mm thick, cast using the aforementioned fiber-reinforced polymer waterproof concrete; interface treatment layer: after the concrete has set, it is roughened or chiseled, and an interface agent is applied to enhance the bond with the insulation layer; bottom waterproof coating: a high-performance waterproof coating with a thickness ≥1.0 mm is applied to the bottom and sides of the concrete.

[0076] Preferably, the waterproof coating adopts a multi-layer composite structure of "primer + intermediate coat + topcoat": Primer: a high-penetration waterproof coating with a penetration depth ≥2 mm and a dosage of 0.3~0.5 kg / m³. 2 Intermediate coating: Uses an elastic waterproof coating with a reinforcing material (such as polyester nonwoven fabric) sandwiched between layers, application rate 1.0~1.5 kg / m². Topcoat: Uses a weather-resistant waterproof coating, application rate 0.3~0.5 kg / m². 2 The total dry membrane thickness is ≥1.0 mm. The waterproof coating has a dual function of "physical shielding + chemical bonding", thus achieving a good and durable waterproof effect.

[0077] Functional drainage grid module The gaps between adjacent floor tiles are designed as functional drainage grid modules. Through the composite integration of a slender grid structure and far-infrared functional materials, the modules achieve the synergistic goals of rapid snowmelt drainage, active elimination of ice crystals in the gaps, and long-term anti-clogging.

[0078] The gap width between the floor tiles is 15mm. The drainage grid module adopts a composite structure of "upper linear drainage grid + lower drainage channel", and adjacent module units are combined to form a complete grid drainage system.

[0079] like Figure 6 As shown, the drainage grille is composed of several far-infrared ceramic frames 18 surrounding each floor tile 1. Embedded brush strips 19 with a width of 3-4 mm are set at the edges of the frames 18 toward the center of the tile gaps.

[0080] Specifically, the brush belt 19 adopts a composite bristle design. The outer layer is made of wavy steel wire (0.5~0.8mm in diameter), with a sparse structure that can block large debris such as leaves and has ice-breaking function, providing mechanical strength. The middle layer is made of high-elasticity nylon (0.3~0.5mm in diameter), occupying the largest area, which elastically intercepts medium-sized particles such as cigarette butts. This nylon material is made by uniformly dispersing 10%~15% far-infrared ceramic powder and 3%~5% graphene powder in a polymer nylon matrix. The inner layer is made of low-temperature resistant polyester soft bristles (0.1~0.3mm in diameter), which filter fine particles such as dust and sand. All the bristles are black to improve light and heat absorption efficiency, and are all flat bristles, not conventional cylindrical. When the support strip is heated, the brush belt absorbs far-infrared rays and generates heat, especially the middle layer, which has the highest heat absorption efficiency. At the same time, it conducts heat to both the inner and outer layers, achieving a low-cost, high-efficiency anti-freezing and de-icing effect.

[0081] The bristles of brush band 19 are tilted downwards at a 10-degree angle for better infrared absorption and faster drainage. Each layer of brush band 19 has a different length, gradually increasing in length from the outermost to the innermost layer, forming a gradient filtration. When water flows through, intercepted debris is washed away, achieving a degree of self-cleaning. The bristle roots are fixed within a prefabricated plastic base, which slides into a T-shaped slot on the frame sidewall for easy replacement. The far-infrared ceramic frame 18 and the partition support strip 20 are synchronously heated to assist the brush in melting snow. A miniature temperature and humidity sensor is embedded in the bristle roots to monitor the gap status in real time. The surface of the brush fibers is coated with a hydrophobic coating to effectively reduce ice crystal adhesion.

[0082] The brush belt 19 physically intercepts and prevents debris from entering the drainage trough 21, while simultaneously using the elastic deformation of the fibers to disrupt the continuity between the ice crystals and the gaps. At low temperatures, the partition support strip 20 activates its heating function, emitting far-infrared radiation. This radiant heat directly heats the far-infrared ceramic frame 18 and the brush belt 19, conducting heat deep into the gaps of the brush belt, thus achieving the dual function of "interception + anti-icing".

[0083] like Figure 7 As shown, the dividing support strip 20 in the middle of the drainage grille is made of far-infrared ceramic material. The upper part is 3mm wide, transitioning to a lower part with a width of 5mm via a 10mm vertical slope. The overall shape is a flat-topped tower, narrower at the top and wider at the bottom, providing sufficient support surface while increasing structural strength and stability. The sloped design creates a smooth guiding surface, directing water flow smoothly into the lower channel and preventing eddies and blockages. On both sides, narrow, straight drain outlets with an upper width of 6mm and a lower width of 5mm are formed. This top-wide, bottom-narrow design prevents blockage of the drain outlets and accelerates runoff discharge.

[0084] The dividing support strip 20 is a far-infrared ceramic material containing 70-80% by mass of basic ceramic components such as kaolin, feldspar, and quartz, 10-15% by mass of a mixture of tourmaline, zirconium oxide, and silicon carbide as far-infrared radiation material, 5-10% by mass of carbon fiber powder as a conductive and heating component, and 2-5% by mass of alumina short fibers to enhance the ceramic strength and prevent breakage. The above components are prepared by compression molding followed by high-temperature co-firing.

[0085] The far-infrared ceramic material has a built-in heating wire that conducts heat and emits far-infrared rays when energized, specifically melting frost in crevices, with a power density of 50~80W / m. The brush strip 19 and the partition support strip 20 can be replaced individually; the modular design facilitates large-scale production and construction.

[0086] The internal conductive heating circuit of the partition support bar 20 is arranged using a double-sided busbar series layout. Two main conductive busbars (silver paste printing or copper strip embedding) are arranged on both sides of the bottom along the length of the support bar, with a width of 2-3mm. Current flows through the conductive components of the support bar body to generate heat; the design power is 50~80 W / m based on the joint length; the power supply voltage is a safe extra-low voltage (36V or 48V), connected via a pre-embedded waterproof cable. Each partition support bar 20 is independently protected by a fuse. Multiple partition support bars 20 are connected in parallel, so a single failure does not affect the overall operation.

[0087] like Figure 7 As shown, a wide-mouth U-shaped drainage trough 21 is installed below the drainage grid. The material is ultra-high molecular weight polyethylene (UHMW-PE). The opening width is 30-50mm, the trough depth is 25-35mm, and the trough wall thickness is 2-4mm. It can completely cover the brick joint area above, receive all incoming water, and ensure sufficient drainage cross-section and drainage slope of ≥3% to ensure that water flow and ice chips are quickly discharged into the water storage and purification module.

[0088] like Figure 2As shown, the functional drainage grid module ensures smooth drainage under low-temperature conditions through a triple mechanism of "geometric anti-clogging + active heating + hydraulic flushing". The drainage channels 21 in each water collection area are uniformly connected to the main drainage pipe 15, and then introduced into the water storage tank 13 through the sedimentation tank 16 and the filter layer 17. The drainage channels 21 and the main drainage pipe 15 are all wrapped with thermal insulation material to prevent snow melt water from freezing.

[0089] The intelligent control strategy for the functional drainage grid module: Anti-freeze preheating mode: When the ambient temperature is <2℃ and the humidity is >80%, the partition support strip 20 will be automatically activated to maintain a low temperature (surface temperature 3-5℃) to prevent dew from freezing at the gaps. Snow melting coordination mode: When the system enters the active snow melting mode, the partition support strip 20 operates at full power synchronously to ensure that the ice crystals in the gaps melt in time.

[0090] Ecological tree pool and dual-mode water storage module Ecological tree pit units 25 are arranged longitudinally along the sidewalk at intervals of 6 to 12 meters, with each tree pit serving a road surface area with a width consistent with the sidewalk itself, within half of the distance between the tree pits. Based on the overall system layout, the typical service catchment area is 15 to 48 m².

[0091] like Figure 2 As shown, the ecological tree pit unit 25 adopts an "overflow-type sunken tree pit" structure. The ecological cycle tree pit unit 25 includes, from top to bottom, a roadside tree 10, a tree pit grate, a planting soil layer 11, a filter layer 17, a permeable geotextile 12, a water storage tank 13, and an impermeable subbase 14.

[0092] Tree grate, made of high-strength recycled resin, 30-45mm thick.

[0093] Planting soil layer 11 is a mixture of 60% nutrient soil, 30% perlite, and 10% organic fertilizer by mass, and is used to irrigate the street trees 10.

[0094] Filter layer 17, 100-150mm thick, is a filter media box consisting of layers of zeolite, agricultural and forestry waste, and coarse quartz sand-based biochar, laid sequentially from top to bottom. The upper layer is zeolite, the middle layer is biochar, and the lower layer is coarse sand filter media, which filters heavy metals, organic pollutants, snow-melting agents, and particulate pollutants through ion exchange adsorption, organic adsorption, and physical filtration, respectively. Waterproof geotextile is laid between each layer, and a water distribution system is installed at the top.

[0095] like Figure 2As shown, the supernatant in the sedimentation tank 16 flows into the filter layer 17 without power through elevation control. An overflow weir is used for water distribution, with the weir crest leveled to ensure uniform overflow and flow through the filter layer 17. A perforated water collection pipe, wrapped with geotextile, is installed at the bottom of the filter layer 17. The end of the water collection pipe connects to the storage tank 13 via a water-sealed bend, ensuring that the filtered water flows into the tank by gravity.

[0096] Permeable geotextile 12 uses 200~300g / m 2 The laying of polyester filament geotextile can prevent soil erosion without affecting water infiltration.

[0097] The water storage tank 13 is located in the longitudinal center of the tree pit unit, below the planting soil and covered with geotextile fabric. The internal volume of the water storage tank 13 is calculated based on the catchment area, local rainfall, and runoff coefficient, and is preferably designed to be 1.8 m × 0.8 m × (1~1.2) m (length × width × depth). The maximum water level is 0.9~1.1 m, which meets both the rainfall collection needs of general northern cities and the irrigation needs of roadside trees during the dry season. The water storage tank 13 adopts a high-strength polypropylene structure and is equipped with an overflow outlet and a vent pipe. When the water level exceeds the design volume, the excess water will automatically overflow and be discharged into the municipal pipe network. The bottom of the tank has a slope of ≥5% as a sludge collection pit.

[0098] Based on the physical properties of water, warmer water is in the upper layer, and cooler water is in the lower layer, with a thermotropic layer in between as a transition. To avoid convection, turbulence, and other phenomena during water intake, and to minimize the temperature impact caused by boundary layer movement, thus preventing the mixing of hot and cold water in the tank and reducing the storage-release efficiency, the water storage tank is equipped with two independent water distributors, one for hot water and one for cold water control. In winter, hot water is drawn from the upper distributor for heat extraction; in summer, hot water is drawn from the upper distributor for heat storage; and in summer, cold water is drawn from the lower distributor for cold storage. The heat pump return water automatically selects the appropriate water layer based on temperature. Independent hot and cold water piping significantly improves the efficiency of heat storage and utilization.

[0099] The water storage tank 13 is equipped with independent water distributors at the top and bottom. Hot water enters and exits from the upper part of the water storage tank 13, while cold water enters and exits from the bottom of the water storage tank 13. Specifically, as shown in the figure... Figure 8 As shown, the water storage tank 13 has a first water distribution pipe 22 with a perforated flow equalization plate 23 installed 50-80mm from the bottom of the tank, and a second water distribution pipe 24 with a perforated flow equalization plate 23 installed 50-80mm from the top of the tank. When the incoming water is cold water, it is directly introduced into the bottom layer of the water storage tank 13 through the first water distribution pipe 22. When the incoming water is hot water, it is introduced into the upper layer of the water storage tank 13 through the second water distribution pipe 24. The height of the second water distribution pipe 24 is controlled by a float ball to ensure uniform water intake underwater. The water distribution pipes are made of HDPE material.

[0100] Two layers of partially sealed HDPE insulation boards 23 are installed in the middle of the water storage tank 13. The two insulation boards 23 are spaced 80-120mm apart, and each layer of insulation boards 23 has an opening on opposite sides. Structurally, this blocks the vertical flow of water between the upper and lower layers, enhancing the stability of the inclined temperature layer between the hot and cold water. The water outlet also adopts a zoned outlet system, with hot water exiting from the upper part of the tank and cold water exiting from the bottom. The outlet pipes are installed accordingly.

[0101] The purified water stored in the reservoir 13 is used for irrigation of roadside trees in the tree pit and to replenish groundwater through a low-pressure drip irrigation pipeline.

[0102] The water storage tank 13 has the following two operating modes: Spring and summer mode (irrigation priority mode): From March to August, the plant growing season, all water is collected and stored in a reservoir to prioritize irrigation needs. Autumn / Winter Mode (Snow Melting Mode): From September to November, residual heat from the road surface during the day can be used to store heat in the water tank, with a target water temperature of 15-20 degrees Celsius, in preparation for snow melting and heating. Before March of the following year, the water tank 13 should be filled with snow melt water as much as possible, and the stored water resources will provide a key water source for the spring tree revival.

[0103] Furthermore, the impermeable subbase layer is 14mm thick, 50-100mm, and laid using compacted clay or bentonite waterproofing blankets. Equipment wells are installed below the pedestrian streetlights 9, facilitating connection to the municipal power grid and allowing one well to simultaneously accommodate all operation and management equipment from two adjacent water collection areas, saving on installation and management costs. One streetlight 9 is installed every two tree pit units, i.e., at the boundary between two adjacent water collection areas, along with one equipment well.

[0104] Dual heat source heating system The dual-heat-source heating system is the core unit of this invention for achieving efficient and energy-saving snow melting. It consists of a carbon fiber electric heating module and a hydro-thermal combined module, forming a "main-auxiliary synergistic" heating system. The carbon fiber electric heating module has a rapid response and high power density, responsible for rapid snow melting and ensuring performance under extreme conditions. The hydro-thermal combined module utilizes heat stored across seasons, amplified by a heat pump to provide basic heating, responsible for energy-saving operation and preheating maintenance. Through intelligent control, the two achieve a collaborative working mode of "time-shifting, spatial complementarity, and optimal energy efficiency," resulting in energy savings of over 60% compared to pure electric heating solutions.

[0105] The carbon fiber electric heating module is shown in the floor tiles above, and will not be described again here.

[0106] The hydro-thermal combined system realizes cross-seasonal energy transfer by storing heat in summer and taking it out in winter through a water storage tank. When used in combination with carbon fiber heating snow melting, the overall energy consumption of the snow melting system can be reduced by more than 60% compared with the pure electric heating solution.

[0107] The combined hydrothermal system includes the following three operating modes: The first-level heat release mode is used when the water temperature in the water storage tank is >25℃. During operation, water is directly drawn from the hot water area and heated to the road surface water heating coil 8 via a plate heat exchanger. There is no energy consumption during operation. The secondary heat release mode is used when the water temperature in the storage tank is 15~25℃. During operation, the water source heat pump unit is started to extract heat from the storage tank and raise the temperature to 45℃ for heating. During operation, the COP of the water source heat pump unit is ≥4.0. The three-stage heat release mode is used when the water temperature in the storage tank is ≤15℃. During operation, the water source heat pump unit operates at full power, and the COP of the water source heat pump unit is approximately 2.5~3.0.

[0108] The mode switching strategy is as follows: When the hot water temperature is >25℃, the first-level heat release mode is activated and the water source heat pump unit is shut down; when the hot water temperature drops to 20℃, it automatically switches to the second-level heat release mode and starts the water source heat pump unit; when the water temperature in the water storage tank 13 drops to 12℃, it automatically enters the third-level heat release mode; when the water temperature in the water storage tank 13 is <5℃, the water source heat pump unit is forcibly shut down, and only the carbon fiber heating wire 7 is activated to melt snow.

[0109] Water and heat combined system piping: The upper and lower water distribution pipes are led out of the tank through DN50 HDPE pipes, and the water pipes are covered with 5 layers of rubber and plastic insulation before being laid to the roadside equipment well. An air vent valve is installed at the lowest point of the pipeline, and an automatic air vent valve is installed at the highest point.

[0110] Heat pump installation: A water source heat pump unit is installed in the equipment well. The evaporator side of the water source heat pump unit is connected to the heat extraction side circulation pump and the water distributor pipeline loop of the water storage tank 13. The condenser side of the water source heat pump unit is connected to the heating side circulation pump and the water heating coil 8 loop in the floor tile 1. The water source heat pump unit, circulation pump, and other equipment in the same equipment well can be used simultaneously for two adjacent snow melting areas. The plate heat exchanger is activated in the first-level heat release mode (pool temperature > 25℃), which can isolate and exchange heat between the hot water in the water storage tank 13 and the circulating water in the road surface coil. The plate heat exchanger is made of 316L stainless steel.

[0111] The operating modes of the combined hydro-heating system are as follows: Winter mode: The water source heat pump unit extracts low-grade heat energy from the water in the water storage tank 13 (the water temperature is usually higher than the air temperature at the same time). After being boosted by the water source heat pump unit, it provides auxiliary heating for the road surface, realizing the seasonal inter-period energy cycle of "extracting in winter and storing in summer". The energy efficiency ratio (COP) can reach 3.5~4.5, which saves more than 60% energy compared with pure electric heating.

[0112] Summer mode: The water source heat pump unit operates in reverse, collecting road surface heat and storing it in the water storage tank 13, which both cools the road surface and stores heat for winter.

[0113] This invention, through the deep integration of material innovation, structural optimization, intelligent control, and ecological design, constructs a composite system and intelligent implementation plan for sidewalk tree pits that integrates passive anti-icing, active snow melting, cross-seasonal energy storage, ecological circulation, and summer cooling. It achieves a leapfrog improvement over existing technologies in snow melting effect, energy conservation, environmental protection, and intelligent operation and maintenance, providing a brand-new technical solution for urban infrastructure construction in cold regions. This invention upgrades sidewalks from simple "hardened paving" to "ecological infrastructure," realizing the synergistic recycling of rainwater, snowmelt water, and heat energy.

[0114] The gradient snow melting strategy of this invention, which is based on "passive triggering and active heating guarantee", can automatically match the optimal heating strategy according to the snow conditions, maximize energy saving while ensuring the snow melting effect, and reduce the operating energy consumption by more than 60% compared with the traditional continuous heating scheme.

[0115] This invention constructs a cross-seasonal energy-saving thermal storage mode for summer storage and winter use, intelligently switching between the "rapid infiltration and regulation" mode in summer and autumn and the "anti-freeze storage" mode in winter and spring. It adapts to the characteristics of cold climate, realizes the annual cycle optimization of water resources, and can intelligently manage precipitation resources. It realizes the seasonal allocation and resource utilization of heat, plays a role in reducing the heat island effect in summer and melting snow and preventing ice in winter, and achieves energy conservation, consumption reduction and resource recycling.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A composite landscape system for urban agglomeration roads based on gradient triggering and resource recycling, characterized in that: It includes a sidewalk made of several paving bricks (1) and an ecological cycle tree pool unit (25) set at intervals along the side of the sidewalk near the roadway. The gaps between the paving bricks (1) are provided with prefabricated functional drainage grid modules. Adjacent functional drainage grid modules are spliced ​​together to form a complete grid drainage system. The floor tile (1) includes a surface layer (2), a heating layer (3), a thermal insulation layer (4), and a waterproof structural base layer (5) arranged sequentially from top to bottom; the heating layer (3) is provided with an S-shaped concrete isolation barrier (6) to divide the brick body into a carbon fiber heating structure and a hydrothermal structure; carbon fiber heating wires (7) and hydrothermal coils (8) are laid on both sides of the barrier (6), and a far-infrared directional radiation coating is applied to the concrete surface; the carbon fiber heating wires (7) and hydrothermal coils (8) are provided with openings at the entrances and exits on both sides of the brick body; The thermal insulation layer (4) is made of vacuum insulation board and extruded polystyrene composite; the waterproof structural base layer (5) includes a structural concrete layer formed by fiber-reinforced polymer waterproof concrete pouring from top to bottom, an interface treatment layer formed by applying interface agent after the concrete has set, and a bottom waterproof coating formed by applying high-performance waterproof coating to the bottom and sides of the concrete. The functional drainage grid module is a composite structure of an upper drainage grid and a lower drainage trough. The drainage grid includes a far-infrared ceramic frame (18) surrounding each floor tile (1), an embedded brush strip (19) set at the edge of the frame (18) towards the center of the gap between the floor tile (1), and a dividing support strip (20) set in the middle of the frame (18). The drainage trough (21) is a wide-mouth U-shaped structure. The ecological cycle tree pit unit (25) includes, from top to bottom, roadside trees (10), tree pit grates, planting soil layer (11), filter layer (17), permeable geotextile (12), water storage tank (13), and impermeable subbase (14). The water storage tank (13) is equipped with water distributors set independently at the top and bottom. Hot water enters and exits from the upper part of the water storage tank (13), and cold water enters and exits from the bottom of the water storage tank (13). The purified water from the water storage tank (13) is used to irrigate the roadside trees (10) through a low-pressure drip irrigation pipeline. The drainage channels (21) in each water collection area are uniformly connected to the main drainage pipe (15) and introduced into the water storage tank (13) through the sedimentation tank (16) and the filter layer (17). An equipment well is set under the pedestrian street light (9). A water source heat pump unit is installed in the equipment well. The evaporator side of the water source heat pump unit is connected to the heat extraction side circulation pump and the water distributor of the water storage tank (13) pipeline circuit. The condenser side of the water source heat pump unit is connected to the heating side circulation pump and the water heating coil (8) circuit in the floor tile (1). When the water temperature in the water storage tank (13) is >25℃, the first-level heat release mode is operated, and water from the hot water area of ​​the water storage tank (13) is directly drawn and heated to the water heating coil (8) through the plate heat exchanger; when the water temperature in the water storage tank (13) is between 15~25℃, the second-level heat release mode is operated, and the water source heat pump unit is started to extract heat from the water storage tank (13) to raise the temperature and provide heating; when the water temperature in the water storage tank (13) is ≤15℃, the third-level heat release mode is operated, and the water source heat pump unit operates at full power.

2. The urban agglomeration road tree pit composite landscape system according to claim 1, characterized in that: The surface of the surface layer (2) is set as a flat-topped pyramid shape, with the square at the top center having a side length of 1 / 5 to 1 / 4 of the side length of the floor tile (1) and a slope of 1.5% to 2.5%. A strip texture with a roughness Ra of 0.8 to 1.5 mm is formed on the surface of the surface layer (2) in the same direction as the slope. The material of the surface layer (2) is prepared by adding 5% to 10% phase change-snow melting composite functional aggregate as the main material of recycled construction waste. The phase change-snow melting composite functional aggregate is a core-shell structure particle with a particle size of 3.0 to 8.0 mm. The phase change-snow melting composite functional aggregate uses a porous material with a bimodal pore size distribution as a carrier. A homogeneous composite of potassium acetate and glycerol is used. Phase change paraffin with a phase change temperature of 1 to 4 °C is selected and filled into the interconnected micropores and macropore entrances inside the carrier through stepwise vacuum impregnation. The porous material has the following pore structure: internal macropores with an average pore diameter of 10–30 μm and a porosity of 40%–50%; and surface interconnected micropores with an average pore diameter of 0.5–2 μm and a porosity of 20%–30%.

3. The urban agglomeration road tree pit composite landscape system according to claim 2, characterized in that: The preparation steps of the phase change-snow melting composite functional aggregate include: Step (1), loading de-icing agent: The carrier is natural / synthetic zeolite, mesoporous silica balls or custom porous ceramic; the dried carrier particles are loaded into a vacuum impregnation tank, sealed tightly, and the vacuum pump is started to evacuate the tank to -0.08~-0.09MPa and maintain this vacuum for 45~60 minutes; the potassium acetate-glycerol solution with a mass ratio of 1:(0.5~2) is heated to 50~60℃, and while maintaining the vacuum, the potassium acetate-glycerol solution preheated to 50~60℃ is drawn into the impregnation tank through the feed valve until the carrier particles are completely submerged. The vacuum is maintained and impregnation is continued for 1~2 hours; after impregnation, the carrier particles are taken out of the solution and placed in a sieve or filter basket to drain naturally for 10~20 minutes. Then the particles are transferred to a centrifuge and centrifuged at 300~500rpm for 0.5~1 minutes. After centrifugation, the particles are thoroughly dried. Step (2), selective filling with paraffin wax: Select phase change paraffin wax and heat it to 10~15℃ above the melting point until it is completely melted into a liquid state. Preheat the carrier particles loaded with de-icing agent after drying in step (1) to 5~10℃ above the melting point of the molten phase change paraffin wax. Put the preheated carrier particles into a vacuum impregnation tank, seal it tightly, start the vacuum pump, and evacuate the vacuum degree in the tank to -0.06~-0.07MPa. Maintain this vacuum degree for evacuation for 30~45 minutes. While maintaining the vacuum, suck the molten phase change paraffin wax into the impregnation tank through the feed valve until the carrier particles are completely submerged. Keep the vacuum degree unchanged and continue impregnation for 4~6 hours. After impregnation is completed, slowly restore the atmospheric pressure and slowly cool the carrier particles. Step (3), post-treatment and cleaning: After the wax is cooled, perform gentle centrifugation or surface scrubbing to remove excess paraffin adhering to the large pore openings; Step (4), encapsulation and protection: fluidized bed coating process is adopted, and bottom spray fluidized bed coating method is used. Ethyl cellulose is used as the wall material to coat the surface of the particles to form an encapsulation and protection layer. The concentration of the coating solution is 4-4.5% ethyl cellulose-ethanol solution. After four stages of preheating-coating-drying-cooling, the encapsulation layer thickness reaches 5-10μm, and the final phase change-snow melting composite functional aggregate is obtained.

4. The urban agglomeration road tree pit composite landscape system according to claim 1, characterized in that: The hydrothermal structure uses PE-Xa pipelines with a diameter of 15-20mm to be laid along an S-shape on one side of the barrier (6) and fixed with U-shaped clips. The surface of the coil is covered with aluminum foil tape. The sidewalk water collection unit is divided into several independent heating zones according to the single loop length ≤80m. Each heating zone is equipped with an independent water supply and return loop. The carbon fiber heating structure consists of carbon fiber heating wires (7) with silicone rubber insulation layer arranged in an S-shape or grid pattern. The outer diameter of the carbon fiber heating wires (7) is 3.0~4.0mm. They are embedded in high thermal conductivity cement mortar at intervals of 80~120mm to form the main heating surface. The thickness is 10~15mm, so that the distance from the center of the carbon fiber heating wires (7) to the surface of the brick is 20~40mm.

5. The urban agglomeration road tree pit composite landscape system according to claim 1, characterized in that: The brush band (19) adopts a composite bristle bundle design. All bristles are black and flat. The bristles are tilted downward at 10° and the length gradually increases from the outer layer to the inner layer. The outer layer of the brush belt (19) is a wavy steel wire with a diameter of 0.5~0.8mm; the middle layer of the brush belt (19) is a high-elasticity nylon material with a diameter of 0.3~0.5mm. The nylon material is made by uniformly dispersing 10~15% far-infrared ceramic powder and 3~5% graphene powder in a polymer nylon matrix; the inner layer of the brush belt (19) is a low-temperature resistant polyester soft bristle with a diameter of 0.1~0.3mm.

6. The urban agglomeration road tree pit composite landscape system according to claim 1, characterized in that: The dividing support strip (20) is generally a flat-topped tower shape that is narrow at the top and wide at the bottom, with narrow strip-shaped straight drain outlets formed on both sides; The dividing support strip (20) is made of far-infrared ceramic material with built-in heating wire; the far-infrared ceramic material contains 70-80% by mass of kaolin, feldspar and quartz basic ceramic components, 10-15% by mass of tourmaline, zirconium oxide and silicon carbide mixture as far-infrared radiation material, 5-10% by mass of carbon fiber powder as conductive heating component, and 2-5% by mass of alumina short fiber to enhance ceramic strength. The above components are prepared by molding and high-temperature co-firing process.

7. The urban agglomeration road tree pit composite landscape system according to claim 1, characterized in that: The sedimentation tank (16) is inlet water from the bottom and supernatant overflows from the top. A triangular weir is provided at the upper outlet for water collection. The filter layer (17) is a filter material box that is filled with zeolite, biochar made from agricultural and forestry waste and coarse quartz sand in layers from top to bottom. Waterproof geotextile is laid between each layer. A water distribution system is set at the top. A perforated water collection pipe is provided at the bottom of the filter layer (17) and wrapped with geotextile. The end of the water collection pipe is connected to the water storage tank (13) through a water seal bend.

8. The urban agglomeration road tree pit composite landscape system according to claim 1, characterized in that: The water storage tank (13) is provided with a first water distribution pipe (22) with a perforated flow equalization plate (23) at a distance of 50-80 mm from the bottom of the tank, and a second water distribution pipe (24) with a perforated flow equalization plate (23) at a distance of 50-80 mm from the top of the tank. When the incoming water is cold water, the water is directly introduced into the bottom layer of the water storage tank (13) through the first water distribution pipe (22). When the incoming water is hot water, the water is introduced into the upper layer of the water storage tank (13) through the second water distribution pipe (24). The height of the second water distribution pipe (24) is controlled by a float. The water outlet of the water storage tank (13) adopts a zoned water outlet, with hot water outlet from the upper part of the water storage tank (13) and cold water outlet from the bottom of the water storage tank (13); The water storage tank (13) is provided with two layers of incompletely sealed HDPE insulation boards (23) in the middle. The two insulation boards (23) are 80-120mm apart and have openings on opposite sides.

9. The urban agglomeration road tree pit composite landscape system according to claim 1, characterized in that: When the temperature of the hot water zone is >25℃, the first-level heat release mode is activated and the water source heat pump unit is shut down; when the temperature of the hot water zone drops to 20℃, it automatically switches to the second-level heat release mode and starts the water source heat pump unit; when the water temperature of the storage tank (13) drops to 12℃, it automatically enters the third-level heat release mode; when the water temperature of the storage tank (13) is <5℃, the water source heat pump unit is forced to stop and only the carbon fiber heating wire (7) is started to melt snow.

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