Downpipe rainwater energy recovery device

Abstract

The invention discloses a rainwater energy recovery device for a downpipe, and belongs to the technical field of energy conservation and resource recovery of building drainage systems. In order to solve the problems that rainwater potential energy is wasted, ground impact erosion is serious and heavy rain easily overflows a traditional downpipe, the device comprises a shell matched with the downpipe, a supporting assembly, a power generation assembly and an overflow assembly. The supporting assembly in the shell positions the power generation assembly, rainwater impacts the impeller to drive the permanent magnet on the inner side to rotate, and electromagnetic induction is formed with the stator boss winding to achieve energy recovery. An outer duct is defined by an annular sleeve on the periphery of the shell and the overflow plate, a pressure sensor on the water flow inlet side is in linkage with an opening and closing valve, and the outer duct is conducted for flow division in heavy rain. The device does not need to reform an original pipe network, can be quickly installed in series, remarkably attenuates rainwater kinetic energy, relieves ground erosion and guarantees heavy rain drainage safety while efficiently recovering dispersive energy, and is suitable for downpipes of various middle and high-rise buildings.

Description

Technical Field

[0001] This invention belongs to the field of energy conservation and resource recycling technology for building drainage systems, specifically relating to a rainwater energy recovery device for downpipes, which is particularly suitable for rainwater discharge pipelines of single buildings. It can achieve synergistic optimization of rainwater energy recovery and ground impact erosion mitigation while ensuring drainage efficiency. Background Technology

[0002] With the increasing global demand for energy conservation, emission reduction, and resource recycling, the fluid potential energy inherent in building drainage systems is gradually becoming a distributed energy source that urgently needs to be developed. As an indispensable drainage component of buildings, downpipes' core function is to guide rainwater from rooftops, balconies, and other areas to the ground or municipal drainage networks. In mid- to high-rise buildings, rainwater accumulates a large amount of potential energy due to gravity as it falls from heights, forming a high-speed water flow. This energy is not recovered or utilized in traditional drainage systems and is directly discharged as kinetic energy, causing significant energy waste and strong impact erosion on ground paving and soil. Long-term use can easily lead to ground damage and soil erosion.

[0003] To address the problem of fluid potential energy waste, various fluid energy recovery devices have emerged in the prior art. For example, the rainwater and sewage wastewater recovery device disclosed in patent CN201510715606.8 adopts a structure of "single turbine - multi-stage stepped impeller - coaxial sleeve type multi-pipeline," which can simultaneously recover the gravitational potential energy of rainwater and domestic sewage from multi-story buildings, making it suitable for large-scale, multi-fluid discharge scenarios such as residential communities. However, such devices have significant limitations: on the one hand, they rely on the coaxial sleeve arrangement of rainwater pipes and multi-story sewage pipes, resulting in a complex structure, requiring modifications to the existing drainage network for installation, leading to high modification costs, and making them unsuitable for standard downpipes already laid in a single building (such as general-purpose downpipes with a nominal diameter of 110mm); on the other hand, their core design goal is to maximize the total amount of energy recovered, without considering the drainage safety of a single rainwater pipe under heavy rainfall, and lacking a targeted overflow protection mechanism. If directly applied to the downpipes of a single building, rainwater is prone to overflowing the pipes due to water flow resistance, affecting the building's safety.

[0004] In addition to these shortcomings, existing energy recovery technologies suffer from two typical drawbacks: one is the use of a single-stage turbine recovery device, which, while relatively simple in structure, has low energy conversion efficiency, limited output power, and is not designed to fit the standardized dimensions of downpipes, making it difficult to directly integrate into existing drainage systems. The other is a scheme using multiple generators connected in series, which can increase energy output, but involves a large number of devices and a complex system. Limited by the confined space inside the downpipe, installation and maintenance are extremely difficult, and it also fails to resolve the core contradiction of balancing power generation and drainage efficiency.

[0005] At the same time, existing technologies generally neglect the secondary problems of rainwater drainage. The high flow rate and strong impact of rainwater at the end of traditional downpipes have caused erosion and damage to the ground around buildings, which has become a common pain point in building operation and maintenance. Existing energy recovery devices mostly focus on energy conversion itself and do not include mitigating rainwater impact in their design goals, thus failing to meet the dual needs of "energy saving and protection".

[0006] In summary, there is an urgent need for a technical solution that can be adapted to existing standard downpipes, has a compact structure, is easy to install, and can simultaneously achieve rainwater energy recovery, drainage safety assurance, and ground impact mitigation. This solution would fill the technological gap in the field of energy-saving retrofitting of downpipes in single buildings and meet the needs of decentralized energy recovery and drainage system optimization for low-rise and high-rise buildings. Summary of the Invention

[0007] To address the aforementioned problems, this invention aims to provide a rainwater energy recovery device for downpipes. A hollow annular sleeve is directly connected in series with the downpipe. An internal rotating and fixed support assembly positions the power generation component, allowing rainwater to impact the hollow impeller, rotating the inner magnet. This rotation, combined with electromagnetic induction from the windings on the stator's outer circumference, achieves energy recovery. Simultaneously, a pressure sensor at the water inlet controls overflow via an opening and closing valve on the annular sleeve. A second bearing and baffle address impeller bottom swaying and rain / insect protection issues. This device balances power generation efficiency and drainage safety without requiring modifications to the existing pipe network, while maintaining a compact structure. It also mitigates rainwater impact and erosion of the ground, resolving the technical pain points of existing devices such as poor adaptability, complex structure, and insufficient protection.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A rainwater energy recovery device for a downpipe includes a shell, which has a cylindrical hollow structure and is adapted to the downpipe, and further includes: Support components are disposed within the housing; The power generation component is rotatably mounted on the support component; An overflow assembly is fitted around the outer periphery of the housing, and a sensing element is provided near the water inlet side of the power generation assembly.

[0009] Furthermore, the power generation component includes: The impeller has a hollow structure and is rotatably mounted on the support assembly, with several magnets arranged on its inner side; The stator is fixedly mounted on the support assembly and coaxially sleeved inside the impeller, with several bosses on its outer periphery; The winding is wound around the boss and corresponds one-to-one with the boss.

[0010] Furthermore, the rainwater energy recovery device for the downpipe also includes: The bearing is a thrust bearing, used to connect the impeller to the top of the stator.

[0011] Furthermore, a gap is provided between the magnet and the stator to form an electromagnetic induction engagement.

[0012] Furthermore, the magnets are permanent magnets, arranged circumferentially along the inner wall of the impeller, and adjacent magnets have opposite polarities.

[0013] Furthermore, the support component includes: A rotating bracket is installed on the side close to the sensing element, and a rotating hole is provided at the central axis for mounting the top of the impeller. A fixed bracket is installed on the opposite side of the rotating bracket and has a fixed hole, the central axis of which coincides with the central axis of the rotating hole.

[0014] Furthermore, the bottom of the stator is configured with a square tenon that fits into the fixed hole.

[0015] Furthermore, the rainwater energy recovery device for the downpipe also includes: The second bearing is a rolling bearing, with its outer ring snapped into the inner wall of the impeller and its inner ring fitted around the outer circumference of the stator.

[0016] Furthermore, the overflow component includes: The annular sleeve has a hollow structure, with both ends adapted to and connected to the downpipe, and the inner wall is connected to the outer shell through an overflow plate. The valve is slidably installed on the water inlet side of the annular sleeve and electrically connected to the sensing element.

[0017] Furthermore, the sensing element is a pressure sensor.

[0018] The beneficial effects of this invention are: 1. In this invention, when rainwater flows through the inner duct, it needs to drive the impeller to rotate to complete energy conversion. During this process, some of the kinetic energy of the water flow is consumed, and the flow velocity is significantly reduced. During heavy rainfall, the diversion effect of the outer duct further disperses the water flow energy, causing a secondary attenuation of the terminal drainage velocity. At the same time, the structural design of the impeller blades not only efficiently captures water flow energy but also buffers and guides the water flow, reducing the force of the water flow directly impacting the ground. From a mechanical structure perspective, this achieves a coordinated effect of energy recovery, velocity attenuation, and impact mitigation, protecting the ground paving and soil from damage.

[0019] 2. In this invention, the overflow assembly uses an annular sleeve, outer shell, and overflow plate to form an outer duct, constituting a dual-duct drainage structure. This ensures energy recovery while reserving sufficient drainage channels. The through-slot in the upper overflow plate provides sliding space for the opening and closing valve. The valve is electrically connected to a sensing element, which detects the water pressure in the inner duct in real time. When the water pressure exceeds a set threshold, the drive mechanism controls the opening and closing valve to slide, aligning the outlet with the leakage hole of the overflow plate, quickly opening the outer duct to achieve flow diversion. This mechanical structure and sensor-linked design ensures dynamic matching of drainage flow rate and rainfall, completely solving the problem of overflow caused by water flow resistance in a single channel.

[0020] 3. In this invention, the inner wall of the rotating bracket's rotating hole in the supporting component is coated with a wear-resistant coating to reduce wear during impeller shaft rotation. The stator bottom uses a square tenon that fits into the fixed hole of the fixing bracket to achieve circumferential limiting and axial fixing, preventing stator displacement or rotation during operation. The thrust bearing is installed between the top of the stator and the inside of the impeller, effectively bearing the axial pressure of the impeller, reducing rotational friction, and improving rotational stability. The second bearing provides limiting support for the impeller from the bottom by engaging the outer ring with the inner wall of the impeller sleeve and the inner ring with the stator, completely solving the defect that the impeller is prone to shaking when relying solely on top support. At the same time, the baffle at the bottom of the second bearing can effectively prevent rainwater, insects, and other foreign objects from entering the impeller interior and the core power generation area, preventing component corrosion or jamming, and further ensuring long-term stable operation of the device. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 For the present invention Figure 1 Top view sectional view; Figure 3 This is a schematic diagram of the annular sleeve-outer shell structure of the present invention; Figure 4 This is a schematic diagram of the shell-impeller structure of the present invention; Figure 5 For the present invention Figure 4 Top view; Figure 6 For the present invention Figure 5 Cross-sectional view at point AA; Figure 7 This is a schematic diagram of the outer shell-rotating bracket-fixed bracket structure of the present invention; Figure 8 This is a schematic diagram of the impeller structure of the present invention; Figure 9 This is a schematic diagram of the bearing-winding-stator structure of the present invention; Figure 10 This is a schematic diagram of the magnet structure of the present invention; Figure 11 This is a schematic diagram of the bearing structure of the present invention; Figure 12 This is a schematic diagram of the opening and closing valve structure of the present invention; Figure 13 This is a schematic diagram of the stator structure of the present invention; Figure 14 This is a cross-sectional view of the annular sleeve-outer shell-overflow plate of the present invention; Figure 15 For the present invention Figure 14 Partial view of point M in the middle.

[0022] in: 1. Outer shell; 101. Mounting hole; 102. Inner channel; 2. Impeller; 201. Blade; 202. Sleeve; 2021. Limiting groove; 203. Rotating shaft; 3. Magnet; 4. Stator; 401. Boss; 5. Winding; 6. First bearing; 7. Rotating bracket; 701. Rotating hole; 8. Fixed bracket; 801. Fixed hole; 9. Second bearing; 10. Annular sleeve; 1001. Outer channel; 11. Opening and closing valve; 1101. Outlet; 12. Sensing element; 13. Overflow plate; 1301. Through groove; 1302. Leakage hole; 1303. Upper overflow plate; 1304. Lower overflow plate. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0024] See attached document Figure 1-15 The rainwater energy recovery device shown has its core structure built around a shell 1, which serves as the mounting base for the entire device and has a columnar hollow structure. An axially continuous inner channel 102 is formed inside the shell 1, serving as the main channel through which rainwater flows and drives the power generation components. An annular gap, defined as an outer duct 1001, is formed between the outer wall of the shell 1 and the surrounding annular sleeve 10, acting as an overflow drainage channel during heavy rainfall. The inner channel 102 and the outer duct 1001 together constitute a dual-duct drainage system, achieving coordinated protection of energy recovery and drainage safety. The side wall of the shell 1 also has mounting holes 101 for fixing the sensing element 12, ensuring that its detection end can extend into the inner channel 102 to monitor water pressure in real time.

[0025] A support assembly is fixedly installed inside the outer casing 1. This assembly consists of a rotating bracket 7 and a fixed bracket 8, which are arranged parallel to each other and spaced apart along the axial direction of the outer casing 1 to form a stable coaxial mounting reference. The rotating bracket 7 is located on the side closer to the sensing element 12 and has an annular plate structure. A through rotating hole 701 is opened at the axis of the rotating bracket 701. The inner wall of the rotating hole 701 is coated with a wear-resistant coating, which can effectively reduce the wear of the impeller 2 shaft 203 during rotation and extend the service life of the device. The fixed bracket 8 is installed on the opposite side of the rotating bracket 7 (i.e., the downstream side of the water flow). Its overall structure is adapted to the rotating bracket 7. A fixed hole 801 is opened at the central axis of the fixed hole 801, and the central axis of the fixed hole 801 is completely coincident with the central axis of the rotating hole 701. This coaxial design ensures the precise assembly of the power generation components and avoids component friction or energy loss caused by eccentricity during operation.

[0026] The power generation assembly is rotatably mounted on a support assembly, including an impeller 2, a stator 4, a magnet 3, a winding 5, a first bearing 6, and a second bearing 9. The impeller 2 has a hollow cylindrical structure, integrally formed from blades 201, a sleeve 202, and a rotating shaft 203. The blades 201 are evenly distributed radially along the outer periphery of the sleeve 202, and their curved shape is optimized for fluid dynamics, highly adaptable to the direction of rainwater flow, maximizing the absorption of water impact and converting it into rotational kinetic energy. The inner wall of the sleeve 202 has several circumferentially evenly distributed limiting grooves 2021, with the magnets 3 correspondingly embedded in the limiting grooves 2021. Adjacent magnets 3 have opposite polarities, ensuring a uniform and stable rotating magnetic field is formed when the impeller 2 rotates. The rotating shaft 203 extends outward from the top center of the sleeve 202, forming a cylindrical structure. Its outer diameter matches the inner diameter of the rotating hole 701 of the rotating bracket 7, allowing insertion into the rotating hole 701 to achieve the rotational assembly of the impeller 2. The stator 4 has a columnar structure with several protrusions 401 evenly distributed around its outer circumference. The winding 5 is made of enameled wire tightly wound around the protrusions 401, forming the armature part for electromagnetic induction. The bottom of the stator 4 is provided with a square tenon, which is precisely matched with the fixed hole 801 of the fixed bracket 8. After the square tenon is inserted into the fixed hole 801, it can realize the circumferential limitation and axial fixation of the stator 4, preventing the stator 4 from rotating or displacing during operation. The stator 4 is completely sleeved inside the sleeve 202 of the impeller 2 and is arranged coaxially with the impeller 2. A preset gap is reserved between the magnet 3 and the outer peripheral wall of the stator 4. This gap provides the necessary magnetic field space for electromagnetic induction and avoids mechanical friction between the magnet 3 and the stator 4 when the magnet 3 rotates. The first bearing 6 is a thrust bearing, installed between the top of the stator 4 and the inside of the sleeve 202 of the impeller 2. The inner ring of the first bearing 6 is tightly fitted to the top end face of the stator 4, and the outer ring is adapted to the inner wall of the sleeve 202. It can effectively withstand the axial pressure of the impeller 2, reduce the axial friction during rotation, and improve the rotational stability and service life of the impeller 2. The second bearing 9 is a rolling bearing. Its outer ring is snapped and fixed to the inner wall of the sleeve 202 of the impeller 2, and its inner ring is snapped and fixed to the outer peripheral wall of the stator 4. It provides limiting support from the bottom of the impeller 2, forming an upper and lower double bearing support structure with the first bearing 6 at the top. At the same time, a partition is fixedly installed at the bottom of the second bearing 9 and near the opening side of the impeller 2. The partition is tightly fitted to the inner wall of the sleeve 202 of the stator 4 and the impeller 2, forming a sealed protective structure, which can effectively prevent rainwater, insects and other foreign objects from entering the interior of the impeller 2 and the core power generation area.

[0027] An overflow assembly is fitted around the outer periphery of the outer casing 1 to divert and drain water during heavy rainfall, preventing rainwater from overflowing the downpipe. It includes an annular sleeve 10, an on / off valve 11, and an overflow plate 13. The annular sleeve 10 is a single tubular structure with connectors at both ends that are compatible with the downpipe specifications, allowing for quick connection and series installation of the entire device with the downpipe. The inner wall of the annular sleeve 10 is fixedly connected to the outer wall of the outer casing 1 via the overflow plate 13, and the three together form an outer duct 1001. The overflow plate 13 is divided into an upper overflow plate 1303 and a lower overflow plate 1304, both with multiple drainage holes 1302 on their surfaces, which communicate with the annular sleeve 10. The upper overflow plate 1303 has a through groove 1301 for the sliding assembly of the on / off valve 11, while the lower overflow plate 1304 has no through groove and its flared opening faces downwards. The on / off valve 11 has a horn-shaped structure, which is adapted to the shape of the upper overflow plate 1303. It is slidably installed on the water inlet side of the annular sleeve 10 and in the through groove 1301 opened in the upper overflow plate 1303. The on / off valve 11 has several through outlets 1101 spaced apart. The specifications of the outlets 1101 are completely matched with the drain holes 1302 on the overflow plate 13. One side of the on / off valve 11 is connected to the drive mechanism, which is electrically connected to the sensing element 12. The drive mechanism can control the rotation or sliding of the on / off valve 11 according to the signal of the sensing element 12, so as to realize the overlap (conduction) or offset (closure) of the outlets 1101 and the drain holes 1302, thereby controlling the on / off state of the outer duct 1001. The sensing element 12 is a pressure sensor. Its fixed end is sealed to the side wall of the housing 1 through the mounting hole 101 of the housing 1. The detection end extends into the water flow channel of the inner channel 102. The output end is electrically connected to the drive mechanism through the wire. It can convert the detected water pressure signal into an electrical signal to provide a trigger basis for overflow control.

[0028] The working principle of this device is as follows: When rainfall is low, the water pressure inside the inner channel 102 does not reach the limit value set by the sensing element 12. The sensing element 12 outputs a shut-off signal, and the drive mechanism controls the opening and closing valve 11 to maintain its initial state. At this time, the outlet 1101 on the opening and closing valve 11 and the leakage hole 1302 on the overflow plate 13 are offset from each other, the outer channel 1001 is in a closed state, and all rainwater flows from top to bottom along the inner channel 102. When the water flows through the impeller 2, it impacts the blades 201 and drives the impeller 2 to rotate at high speed around the support assembly. The magnet 3 on the inner wall of the sleeve 202 of the impeller 2 rotates synchronously with the impeller 2, forming a uniform and stable rotating magnetic field. The winding 5 on the outer peripheral boss 401 of the stator 4 cuts the magnetic field lines in the rotating magnetic field, generating an alternating electromotive force. This electromotive force is led out through a preset circuit and can be directly used for indoor lighting and other electrical equipment, or stored in an energy storage device for later use. Meanwhile, as rainwater drives the impeller 2 to rotate, some of its kinetic energy is converted into electrical energy, effectively reducing the water flow velocity and significantly weakening the impact force when it is subsequently discharged to the ground, thereby reducing the impact and erosion effect on the ground.

[0029] When rainfall is heavy, rainwater accumulates in the inner channel 102, causing the water level to rise. If the water pressure exceeds the limit set by the sensing element 12, the sensing element 12 immediately sends an opening signal to the drive mechanism. The drive mechanism then rotates or slides the opening / closing valve 11, causing the outlet 1101 on the valve 11 to completely align with the drain hole 1302 on the overflow plate 13, thus opening the outer channel 1001. Excess rainwater flows smoothly through the path of inner channel 102 → drain hole 1302 → outlet 1101 → outer channel 1001, and is then discharged into the downstream downpipe via the lower overflow plate 1304 at the bottom of the annular sleeve 10. This prevents rainwater from overflowing the downpipe due to slight obstruction of the water flow by the power generation components, ensuring drainage safety. When the rainfall decreases and the water pressure in the inner duct 102 drops below the set value, the sensing element 12 sends a shutdown signal, the drive mechanism controls the opening and closing valve 11 to reset, the outer duct 1001 closes, and the device returns to the working state of energy recovery.

[0030] Specific application examples: This case study selects a high-rise residential building (18 stories, 54m high) in a city as the application object. The exterior facade of the building already has six standard PVC downpipes with a nominal diameter of 110mm. Each downpipe corresponds to a roof catchment area of ​​approximately 25㎡. During normal rainfall, the falling rainwater has sufficient potential energy, but during heavy rain, there have been issues with rainwater impacting the ground paving at the ends of the downpipes, causing localized loosening and damage to the floor tiles. To achieve synergistic optimization of rainwater energy recovery and ground protection, the rainwater energy recovery device of this invention is installed in series in the middle section of the downpipes between the 3rd and 4th floors of the building. This requires no modification to the existing downpipe network and allows for rapid assembly via flange connection. The specific installation process of this device is as follows: Connect the two ends of the annular sleeve 10 to the upper and lower sections of the original downpipe respectively, and seal and fix it by tightening the flange with bolts. The whole device is embedded in the downpipe pipeline, with an installation length of only 35cm, which does not occupy additional building space.

[0031] The rotating bracket 7 and the fixed bracket 8 are fixed to the inner wall of the outer casing 1 by welding to ensure that the power generation component is coaxial with the downpipe after installation. The upper overflow plate 1303 is fixed to the upper end of the inner wall of the annular sleeve 10 by bolts, and its through groove 1301 is slidably adapted to the opening and closing valve 11. The lower overflow plate 1304 is fixed to the lower end of the inner wall of the annular sleeve 10. Both are connected to the outer duct 1001 through the water leakage hole 1302 to ensure the flow of rainwater.

[0032] The winding 5 of the power generation component is connected to the emergency lighting system and energy storage battery pack (capacity 5kWh) of the residential building corridor through a waterproof junction box, and the output voltage is set to 220V AC. The pressure threshold of the sensing element 12 (pressure sensor) is set to 0.3MPa (corresponding to a rainfall of about 20mm / h, i.e., the critical value of moderate to heavy rain), and is linked to the drive mechanism of the opening and closing valve 11 through wires to realize electrical signal linkage.

[0033] Actual operating results: 1. When rainfall is low (daily rainfall ≤ 15mm, water pressure in channel 102 < 0.3MPa) Device operating status: When the sensing element 12 detects that the water pressure has not reached the threshold, it outputs a shut-off signal. The opening and closing valve 11 remains in its initial position. The outlet 1101 and the leakage hole 1302 of the upper overflow plate 1303 are offset from each other. The outer duct 1001 is in the closed state. All rainwater flows from top to bottom along the inner duct 102.

[0034] Energy recovery effect: Rainwater impacts the blades 201 of impeller 2, causing impeller 2 to rotate at approximately 800 r / min. The permanent magnet 3 on the inner wall of the sleeve 202 of impeller 2 forms a stable rotating magnetic field. The winding 5 on the boss 401 of stator 4 cuts the magnetic field lines to generate an alternating electromotive force. The output power of the device corresponding to a single downpipe is approximately 30W, and the total output power of six downpipes is 180W. This electrical energy is prioritized to supply 12 emergency lights in the corridor (each with a power of 12W). The remaining electrical energy is stored in the energy storage battery pack. Approximately 0.36 kWh of electrical energy can be stored in 2 hours of daily rainfall, which can meet the emergency lighting needs of the corridor for approximately 30 hours.

[0035] Ground protection effect: After rainwater flows through the internal channel 102 and passes through the power generation components, the water flow velocity drops from the original 6.8m / s to 3.2m / s, and the kinetic energy is reduced by about 75%. When rainwater is discharged at the end of the downpipe, the impact pressure on the ground drops from 0.8MPa to 0.2MPa, and it no longer causes impact damage to the floor tiles.

[0036] 2. During periods of heavy rainfall (daily rainfall > 20 mm, water pressure in channel 102 ≥ 0.3 MPa) Device operating status: When the sensing element 12 detects that the water pressure in the inner channel 102 has reached the threshold, it immediately sends an opening signal to the drive mechanism. The electric push rod drives the opening and closing valve 11 to slide along the through groove 1301 of the upper overflow plate 1303, so that the outlet 1101 and the leakage hole 1302 are completely aligned, and the outer channel 1001 is open.

[0037] Drainage safety assurance: Excess rainwater is diverted through the following path: inner channel 102 → water leakage hole 1302 of upper overflow plate 1303 → water outlet 1101 of valve 11 → outer channel 1001 → water leakage hole 1302 of lower overflow plate 1304. The flow area of ​​outer channel 1001 is 0.008㎡, which is close to the flow area of ​​inner channel 102 (0.0095㎡), ensuring that the total drainage flow is not lower than the original downpipe design flow (12L / s) and that no rainwater overflows the downpipe.

[0038] Synergistic effect: Even during heavy rain (daily rainfall of 50mm), the power generation components maintained stable operation. Although the output power of a single unit dropped to 22W due to partial water diversion, the total output power of the six units was 132W, which was still sufficient for emergency lighting power supply. At the same time, after the rainwater was diverted through the double culverts, the flow velocity at the end was further reduced to 2.8m / s, and the problem of ground impact erosion was completely solved.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A rainwater energy recovery device for a downpipe, comprising a housing (1) having a columnar hollow structure and adapted to the downpipe, characterized in that, Also includes: A support assembly is disposed within the housing (1); The power generation component is rotatably mounted on the support component; An overflow assembly is provided around the outer periphery of the housing (1), and a sensing element (12) is provided near the water inlet side of the power generation assembly.

2. The rainwater energy recovery device for downpipes according to claim 1, characterized in that, The power generation components include: The impeller (2) has a hollow structure and is rotatably mounted on the support assembly. Several magnets (3) are provided on the inner side. The stator (4) is fixedly installed on the support assembly and coaxially sleeved inside the impeller (2), with several bosses (401) on its outer periphery. The winding (5) is wound around the boss (401) and corresponds one-to-one with the boss (401).

3. The rainwater energy recovery device for downpipes according to claim 2, characterized in that, Also includes: The first bearing (6) is a thrust bearing used to connect the impeller (2) to the top of the stator (4).

4. The rainwater energy recovery device for downpipes according to claim 2, characterized in that, A gap is provided between the magnet (3) and the stator (4) to form an electromagnetic induction engagement.

5. The rainwater energy recovery device for downpipes according to claim 2, characterized in that, The magnet (3) is a permanent magnet, which is arranged circumferentially along the inner wall of the impeller (2), and the polarities of adjacent magnets (3) are opposite.

6. The rainwater energy recovery device for downpipes according to claim 2, characterized in that, The support components include: A rotating bracket (7) is installed on one side close to the sensing element (12), and a rotating hole (701) is provided at the central axis. The rotating hole (701) is used for mounting the top of the impeller (2). A fixed bracket (8) is installed on the opposite side of the rotating bracket (7) and has a fixed hole (801) with the central axis of the fixed hole (801) coinciding with the central axis of the rotating hole (701).

7. The rainwater energy recovery device for downpipes according to claim 6, characterized in that, The bottom of the stator (4) is provided with a square tenon, which is adapted to the fixed hole (801).

8. The rainwater energy recovery device for downpipes according to claim 2, characterized in that, Also includes: The second bearing (9) is a rolling bearing, with its outer ring snapped into the inner wall of the impeller (2) and its inner ring fitted around the outer circumference of the stator (4).

9. The rainwater energy recovery device for downpipes according to claim 1, characterized in that, The overflow component includes: The annular sleeve (10) has a hollow structure, and its two ends are respectively adapted to the downpipe. The inner wall is connected to the outer shell (1) through the overflow plate (13). The valve (11) is slidably installed on the water inlet side of the annular sleeve (10) and electrically connected to the sensing element (12).

10. The rainwater energy recovery device for downpipes according to claim 9, characterized in that, The sensing element (12) is a pressure sensor.

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