Building-oriented rainwater utilization dual-effect power generation device and method thereof

Abstract

This invention relates to the interdisciplinary field of green energy development and water resource utilization, and discloses a dual-effect power generation device and method for building rainwater utilization, comprising a water storage component including a water storage tank installed in the roof catchment area of ​​a building. In this invention, rainwater flows sequentially through a primary, secondary, and tertiary pipe with progressively decreasing diameters, achieving a gradual increase in flow velocity. The increased flow velocity drives three stages of turbine rotation, converting potential and kinetic energy into mechanical energy, which is then converted into electrical energy by corresponding generators. This staged power generation improves energy recovery efficiency. The electrical energy at each stage is initially stored in its corresponding energy storage unit before being collected into a central energy storage unit for final energy storage. The entire device achieves the orderly storage and discharge of building rainwater, alleviating drainage pressure, reducing water waste, and simultaneously converting surplus rainwater energy into clean electricity, achieving a synergistic effect of water storage and power generation, thereby improving rainwater resource utilization and green energy-saving benefits.

Description

Technical Field

[0001] This invention relates to the interdisciplinary field of green energy development and water resource utilization, and in particular to an energy storage dual-effect power generation device and method for building rainwater utilization. Background Technology

[0002] With the acceleration of urbanization and the in-depth promotion of green building concepts, rooftop rainwater harvesting and utilization systems have been widely used both domestically and internationally. To further improve the resource utilization level of rainwater resources and achieve energy conservation, emission reduction, and green power generation, existing technologies often include rainwater power generation devices. These devices mainly consist of rainwater collection hoppers, guide pipes, turbine mechanisms, rotating shafts, generators, voltage stabilization and rectification modules, and power output components. During operation, rooftop rainwater flows into the guide pipes through the collection hoppers. Under the action of gravity, the water flow is transported downwards along the pipes, impacting the turbine blades at the end of the pipes, driving the turbine and rotating shaft to rotate. This converts the kinetic and potential energy of the water flow into mechanical energy, which is then converted into electrical energy by the generator. After voltage stabilization and rectification, the electrical energy is supplied to low-voltage electrical equipment in the building or connected to an energy storage system, thereby realizing the recovery and power generation of rainwater energy.

[0003] However, existing rainwater power generation devices suffer from significant head loss and local resistance loss due to intense friction between the water flow and the pipe walls during long-distance pipe flow. A large amount of hydraulic energy is consumed during transport, leaving only a portion of effective energy at the turbine at the pipe end, resulting in extremely low energy utilization. Furthermore, traditional power generation methods are highly dependent on water flow rate and velocity. In light rain conditions, the low flow rate and velocity result in insufficient harvestable hydraulic energy to drive the turbine at the pipe end, or only allow it to idle slightly, making stable and effective power generation difficult. In heavy rain conditions, the rapid and turbulent flow within the pipe makes it impossible to fully capture and convert the kinetic and potential energy of the turbulent flow, hindering efficient and full utilization of water energy and preventing the realization of both energy recovery and efficient utilization. This limits the green and energy-saving potential of building rainwater systems. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a dual-effect energy storage power generation device and method for building rainwater utilization.

[0005] This invention provides a dual-effect power generation device for building rainwater utilization, including a water storage component. The water storage component includes a water storage tank installed in the water collection area of ​​the building roof. The water storage tank is provided with an inlet, an outlet and an overflow outlet. The inlet is connected to a rainwater collection channel. A graded variable diameter pipeline includes a primary pipeline, a secondary pipeline, and a tertiary pipeline connected sequentially from top to bottom with gradually decreasing diameters. The primary pipeline is connected to the outlet. A staged turbine assembly includes a first-stage turbine, a second-stage turbine, and a third-stage turbine sequentially disposed in the first-stage pipe, the second-stage pipe, and the third-stage pipe along the water flow direction; The power generation assembly includes a first generator, a second generator, and a third generator, which are respectively connected to the first-stage turbine, the second-stage turbine, and the third-stage turbine in a one-to-one correspondence. An energy storage component includes a first energy storage unit, a second energy storage unit, a third energy storage unit, and a total energy storage unit. The first energy storage unit, the second energy storage unit, and the third energy storage unit are respectively connected to the output terminals of the first generator, the second generator, and the third generator, and are connected in parallel to the total energy storage unit. An automatic switching component is located inside the water storage tank and works in conjunction with the water outlet to control the opening and closing of the water outlet. The automatic switching component is driven by the buoyancy of the water flow to achieve automatic switching between water storage and drainage in the water storage tank.

[0006] Furthermore, the automatic switching component includes a first connecting rod and a second connecting rod disposed inside the water storage tank. The first connecting rod and the second connecting rod are arranged in a V-shape. The connecting ends of the first connecting rod and the second connecting rod are rotatably connected to the inner side wall of the water storage tank. A float ball is fixedly connected to the other end of the first connecting rod, and a stop block is fixedly connected to the other end of the second connecting rod. The stop block cooperates with the water outlet to block or release the water outlet.

[0007] Furthermore, the angle between the first link and the second link is α, and 0° < α < 90°.

[0008] Furthermore, the automatic switching component includes two operating modes: water storage mode and drainage mode. In the water storage mode, the float is located below the preset water level, the first and second connecting rods are stationary, and the baffle blocks the water outlet. When in drainage mode, the water level in the water tank is at a preset level. The float rises with the water level due to the buoyancy of the water flow, causing the first connecting rod and the second connecting rod to rotate. The stop block releases the water outlet.

[0009] Furthermore, it also includes a rainwater purification system, with the end of the three-stage pipeline connected to the rainwater purification system to realize the recycling of rainwater after power generation.

[0010] A method for generating electricity using a dual-effect energy storage power generation device for building rainwater utilization includes the following steps: After rainwater is collected through the roof drainage channel, it enters the water storage tank through the inlet. The automatic switching component controls the outlet to close, and the water storage tank stores water. At this time, the water storage tank is in water storage mode. When the water tank is filled to the preset water level, it enters the drainage mode. The automatic switching component controls the opening of the water outlet. The water flows through the water outlet into the graded variable diameter pipe, and flows through the first-level pipe, the second-level pipe and the third-level pipe in sequence, gradually accelerating out. After being accelerated and flowing out, the water sequentially impacts the first-stage turbine, the second-stage turbine, and the third-stage turbine, driving the corresponding turbines to rotate. Each turbine drives the corresponding first, second, and third generators to convert the kinetic energy of the water into electrical energy. The electrical energy output by the first, second, and third generators is sent to the corresponding first, second, and third energy storage units for independent storage. The electrical energy output by each energy storage unit is then connected in parallel to the main energy storage unit for convergence and unified storage, realizing multi-stage power generation from rainwater.

[0011] Furthermore, when the water storage tank is in water storage mode, the following steps are included: When the float is below the preset water level, the first and second connecting rods are stationary, the stop block blocks the water outlet, and water is stored inside the water tank. When the water storage tank is in drainage mode, the following steps are included: After the water tank is filled to the preset water level, the float rises with the water level due to the buoyancy of the water flow, causing the first and second connecting rods to rotate. The second connecting rod drives the stop block away from the outlet, at which point the outlet is released to drain water. When the water tank is in the drainage mode, the stop block remains open, and the water flows directly downstream through the outlet.

[0012] Compared with the prior art, the technical solution provided by the embodiments of the present invention has the following advantages: In the present invention, rainwater flows sequentially through a primary pipe, a secondary pipe, and a tertiary pipe with progressively smaller diameters, achieving a progressively increasing flow velocity. The water flow with increased velocity drives the rotation of three-stage turbines, converting potential energy and kinetic energy into mechanical energy, which is then synchronously converted into electrical energy by the corresponding generators. This achieves staged power generation to improve energy recovery efficiency. The electrical energy at each stage is initially stored in the corresponding energy storage unit and then uniformly merged into the main energy storage unit to complete energy storage. The entire device realizes the orderly storage and discharge of building rainwater, alleviating drainage pressure and reducing water waste. At the same time, it converts the surplus energy of rainwater into clean electrical energy, achieving a dual-effect synergy of water storage and power generation, thereby improving the utilization rate of rainwater resources and green energy-saving benefits. Attached Figure Description

[0013] Figure 1 A schematic diagram of the overall structure of a dual-effect energy storage power generation device for building rainwater utilization provided in an embodiment of the present invention; Figure 2A schematic diagram of a staged variable diameter pipe, a staged turbine assembly, and a power generation assembly provided in an embodiment of the present invention; Figure 3 A schematic diagram of the water storage tank and automatic switching component provided in an embodiment of the present invention; Figure 4 This is a flowchart illustrating a power generation method for a dual-effect energy storage power generation device for building rainwater utilization, provided as an embodiment of the present invention.

[0014] Explanation of reference numerals in the attached figures: 1. Water storage tank; 101. Inlet; 102. Outlet; 103. Overflow outlet; 2. Graded reducing pipes; 201. Grade I pipe; 202. Grade II pipe; 203. Grade III pipe; 3. Staged turbine assembly; 301, First-stage turbine; 302, Second-stage turbine; 303, Third-stage turbine; 4. Power generation components; 401. First generator; 402. Second generator; 403. Third generator; 5. Energy storage components; 501. First energy storage unit; 502. Second energy storage unit; 503. Third energy storage unit; 504. Total energy storage unit; 6. Automatic switching component; 601. First link; 602. Second link; 603. Float; 604. Stop; 7. Rainwater purification system. Detailed Implementation

[0015] The following detailed description of a specific embodiment of the present invention is provided in conjunction with the accompanying drawings. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiment.

[0016] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solution of this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0017] The present invention will be described below through several specific embodiments. To keep the following description of the embodiments clear and concise, detailed descriptions of known functions and components may be omitted. When any component of an embodiment of the present invention appears in more than one drawing, the component may be represented by the same reference numerals in each drawing.

[0018] like Figures 1-4 As shown, this embodiment provides an energy storage dual-effect power generation device for building rainwater utilization, including a water storage component. The water storage component includes a water storage tank 1 installed in the water collection area of ​​the building roof. The water storage tank 1 is provided with an inlet 101, an outlet 102 and an overflow outlet 103. The inlet 101 is connected to the rainwater collection channel. The graded variable diameter pipe 2 includes a first-stage pipe 201, a second-stage pipe 202 and a third-stage pipe 203 connected from top to bottom with gradually decreasing pipe diameters. The first-stage pipe 201 is connected to the outlet 102. The staged turbine assembly 3 includes a first-stage turbine 301, a second-stage turbine 302, and a third-stage turbine 303, which are sequentially arranged in a first-stage pipe 201, a second-stage pipe 202, and a third-stage pipe 203 along the water flow direction. The power generation component 4 includes a first generator 401, a second generator 402, and a third generator 403 that are respectively connected to the first-stage turbine 301, the second-stage turbine 302, and the third-stage turbine 303. The energy storage component 5 includes a first energy storage unit 501, a second energy storage unit 502, a third energy storage unit 503, and a total energy storage unit 504. The first energy storage unit 501, the second energy storage unit 502, and the third energy storage unit 503 are respectively connected to the output terminals of the first generator 401, the second generator 402, and the third generator 403 and are connected in parallel to the total energy storage unit 504. Automatic switching component 6 is located inside water storage tank 1 and cooperates with water outlet 102 to control the opening and closing of water outlet 102. Automatic switching of water storage and drainage in water storage tank 1 is achieved by driving automatic switching component 6 through water flow buoyancy. The water storage tank 1 is installed in the rooftop rainwater collection area. An inlet 101, connected to the rooftop rainwater collection channel, collects rainwater from the roof, providing temporary storage. A detachable filter screen, made of corrosion-resistant stainless steel, is installed at the inlet 101. The mesh size is suitable for filtering conventional sediment and dust, effectively intercepting impurities carried in the rainwater without obstructing its flow. The detachable structure facilitates easy removal and cleaning of blockages, ensuring smooth rainwater flow and preventing impurities from accumulating at the bottom of the tank or in the turbine gap, thus avoiding pipe blockage and affecting turbine operation. The system operates continuously for power generation. When rainfall is excessive, excess rainwater can be discharged through the top overflow outlet 103 to prevent overloading of the water storage tank. The automatic switching component 6, located inside the water storage tank 1, works in conjunction with the outlet 102 to control the opening and closing of the outlet 102. The automatic switching component is driven by the buoyancy of the water flow to automatically switch between water storage and drainage in the water storage tank, controlling the flow of water. When the outlet 102 is opened, the rainwater in the water storage tank 1 flows out and enters the graded reducing pipe 2 connected to the outlet 102, flowing sequentially through the primary pipe 201, the secondary pipe 202, and the tertiary pipe 203, whose diameters decrease in stages. As the pipe diameter decreases, the flow velocity gradually increases, effectively converting the gravitational potential energy of the rainwater into kinetic energy. This, combined with the first-stage turbine 301, second-stage turbine 302, and third-stage turbine 303 sequentially arranged along the flow direction, allows water flows of different velocities to drive the corresponding turbines to rotate, efficiently converting the gravitational potential energy and kinetic energy of the rainwater into mechanical energy. The first-stage generator 401, second-stage generator 402, and third-stage generator 403, respectively connected to these turbines, simultaneously convert the mechanical energy into electrical energy, achieving staged power generation to significantly improve rainwater energy recovery efficiency and avoid energy waste. The electrical energy output by each stage of the generator is... The system connects to the first energy storage unit 501, the second energy storage unit 502, and the third energy storage unit 503 for initial storage, and then connects to the total energy storage unit 504 in parallel for convergence and unified storage. This achieves efficient integration of power generation and energy storage. The entire device not only realizes the resource-based storage and orderly discharge of building rainwater, alleviating the pressure of building rainwater discharge and reducing water waste, but also converts the surplus energy of rainwater flow into usable electrical energy through graded variable diameter speed increase and multi-stage turbine power generation, achieving a dual-effect synergy of water storage and power generation. This enables multi-stage power generation and recycling of rainwater, thereby improving the resource utilization rate of rainwater and green energy-saving benefits.

[0019] Furthermore, such as Figures 1-4As shown, the automatic switching component 6 includes a first connecting rod 601 and a second connecting rod 602 disposed inside the water storage tank 1. The first connecting rod 601 and the second connecting rod 602 are arranged in a V-shape. The connecting ends of the first connecting rod 601 and the second connecting rod 602 are rotatably connected to the inner side wall of the water storage tank 1. A float ball 603 is fixedly connected to the other end of the first connecting rod 601, and a stop block 604 is fixedly connected to the other end of the second connecting rod 602. The stop block 604 cooperates with the water outlet 102 to block or release the water outlet 102. When rainwater flows to inlet 101, it first accumulates in storage tank 1. At this time, float 603 is below the preset water level, first link 601 and second link 602 are stationary, and stop block 604 blocks outlet 102. Storage tank 1 is in water storage mode. When the water level in storage tank 1 rises to the preset water level, float 603, driven by buoyancy, rises with the water level, causing first link 601 and second link 602 to rotate. Stop block 604 releases outlet 102, achieving automatic drainage. When the water level in storage tank 1 drops below the preset water level, float 603 sinks, causing first link 601 and second link 602 to reset, and stop block 604... By resealing the outlet 102 and stopping drainage, the entire process can be automatically controlled to start and stop the drainage of the water storage tank without manual intervention. This not only ensures that rainwater can be fully collected and gradually transported to the staged turbine assembly 3 during light rain, ensuring that the first-stage turbine 301, the second-stage turbine 302, and the third-stage turbine 303 can continuously generate electricity under stable head, but also allows the outlet 102 to be opened instantly during heavy rain by utilizing the rapidly accumulated high water pressure to form a high-velocity water flow, maximizing the use of water flow energy and avoiding overflow losses. This achieves a dual-effect switching between slow drainage and rapid direct discharge.

[0020] Furthermore, such as Figures 1-4 As shown, the angle between the first link 601 and the second link 602 is α, and 0° < α < 90°, which ensures smooth linkage transmission. When the float 603 is subjected to buoyancy, it can drive the stop block 604 to move smoothly, so as to block or release the outlet 102, realize the switching of drainage start and stop, avoid rotation jamming, ensure the stability of water storage and drainage process, and thus ensure the efficient power generation of the whole device.

[0021] Furthermore, such as Figures 1-4 As shown, it also includes a rainwater purification system 7. The end of the three-stage pipe 203 is connected to the rainwater purification system 7 to realize the recycling of rainwater after power generation. The rainwater purification system 7, connected to the end of the three-stage pipe 203, can receive rainwater after the staged turbine power generation and purify it. On the basis of completing rainwater energy recovery and power generation, it further realizes water purification and resource reuse, thereby improving the comprehensive utilization efficiency of rainwater.

[0022] like Figures 1-4As shown, a dual-effect power generation method for building rainwater utilization includes the following steps: S1. After rainwater is collected through the roof drainage channel, it enters the water storage tank 1 through the rainwater inlet 101. The automatic switching component 6 controls the outlet 102 to close, and the water storage tank 1 stores water. At this time, the water storage tank 1 is in the water storage mode. Specifically, the water tank 1 enters the water storage mode, the float 603 is located below the preset water level, the first link 601 and the second link 602 are stationary, the stop block 604 blocks the water outlet 102 and closes the water outlet 102. As rainwater continues to flow in, the water level in the water tank 1 gradually rises, and the water tank 1 begins to store water. When the rainfall intensity is too high and the water level in the water storage tank 1 exceeds the maximum water storage capacity of the water storage tank 1, the excess water will be discharged directly through the overflow port 103 at the top of the water storage tank 1 to prevent the water storage tank 1 from being damaged due to overload and to ensure the safe operation of the entire device.

[0023] S2. When the water storage tank 1 is filled to the preset water level, it enters the drainage mode. The automatic switching component 6 controls the outlet 102 to open. The water flows through the outlet 102 into the graded variable diameter pipe 2, and flows through the first-level pipe 201, the second-level pipe 202 and the third-level pipe 203 in sequence, gradually accelerating outward. Specifically, after the water tank 1 is filled with water to the preset water level, the float 603 is driven by the buoyancy of the water flow and rises with the water level, causing the first connecting rod 601 and the second connecting rod 602 to rotate. The second connecting rod 602 drives the stop block 604 away from the outlet 102. At this time, the outlet 102 is released to drain water. When the water tank 1 is in the drainage mode, the stop block 604 remains open, and the water flows directly downstream through the outlet 102. The preset water level of the water storage tank 1 is two-thirds of its maximum water storage capacity. The float 603 and the baffle 604 are both made of low-density corrosion-resistant materials. When the water storage tank 1 is filled to the preset water level, the buoyancy of the water inside is greater than the weight of the float 603 itself, so that it can float on the water surface and respond accurately to changes in water level. At the same time, it can resist the corrosion caused by long-term soaking in rainwater and extend its service life. Meanwhile, the staged variable diameter pipe 2 achieves a secondary increase in water flow velocity by changing the cross-sectional area of ​​the pipe, allowing the stable water flow to form the optimal flow state in the pipe, further improving the turbine energy capture efficiency. (1) Pipeline structure design The primary pipeline 201 is precisely connected to the outlet 102 of the water storage tank 1 to ensure a smooth water flow, reduce local head loss at the inlet, and mainly receive the water discharged from the water storage tank 1, maintaining a low flow rate and reducing friction loss along the way. The diameter of the secondary pipe 202 is appropriately reduced, and a gradual connection is adopted between it and the primary pipe 201 to ensure a smooth transition of water flow during the diameter change process, avoid the generation of eddies and separation flow, and effectively reduce local head loss. The secondary pipe 202 achieves the first increase in flow velocity through the reduction of pipe diameter, providing a higher speed water flow impact for the second turbine 302. The diameter of the tertiary pipe 203 is further reduced, and it adopts the same gradual connection as the secondary pipe 202. The tertiary pipe 203 achieves a secondary increase in flow velocity, enabling the water flow to obtain the highest speed, providing the maximum kinetic energy for the third-stage turbine 303, and maximizing the recovery of residual low-order energy.

[0024] (2) Continuity equation and velocity increase The stepped variable-diameter pipe 2 achieves a gradual increase in flow velocity based on the continuity equation, the formula of which is as follows: , in, Water flow rate; , The velocity of the water flow; , This refers to the cross-sectional area of ​​the pipe. According to the continuity equation, at the water flow rate Under constant conditions, the flow velocity v is inversely proportional to the cross-sectional area S of the pipe. When the cross-sectional area of ​​the pipe decreases, the flow velocity increases accordingly. Therefore, after the cross-sectional area of ​​the secondary pipe 202 is reduced, the flow velocity in the pipe is significantly increased compared with the traditional equal-diameter pipe at the same flow rate. The cross-sectional area of ​​the tertiary pipe 203 is further reduced, and the flow velocity is further increased, forming a water flow state of progressive acceleration.

[0025] (3) Bernoulli equation and energy density improvement According to Bernoulli's equation, as the flow velocity increases, the velocity head also increases accordingly, further increasing the energy density of the water flow. The formula for Bernoulli's equation is as follows: , in, , Potential energy or position head per unit weight of fluid at a certain point; , This refers to the pressure energy or pressure head per unit weight of fluid at the corresponding point. , The average kinetic energy or average velocity head per unit weight of fluid across the flow cross section; This refers to the total head loss of the flow. When the flow velocities v1 and v2 increase, the velocity head... , Correspondingly, under the premise of total energy conservation, the increase in flow velocity head means an increase in the kinetic energy per unit weight of fluid, and the ability of water flow to do work is enhanced. This increase in energy density creates more favorable conditions for subsequent turbine energy capture, enabling the turbine to obtain greater driving torque and improve power generation efficiency. Similarly, the principle is also applied to the flow of water from the secondary pipe 202 into the tertiary pipe 203. By gradually changing the diameter, the flow velocity is increased step by step and the energy density is enhanced step by step. Through this staged variable diameter pipe design, the water flow state can be effectively optimized, thereby improving the energy capture capability of the entire power generation device.

[0026] S3. After the water flows out through the acceleration, it impacts the first-stage turbine 301, the second-stage turbine 302 and the third-stage turbine 303 in sequence, driving the corresponding turbines to rotate. According to the actual working conditions of rainwater flow, the staged turbines and the water storage tank 1 are precisely matched for both water storage and drainage, so as to achieve the stepwise capture of energy. (1) Initial energy capture The first-stage turbine 301 is located in the middle of the first-stage pipe 201. As the core for the initial capture of rainwater energy, it receives the stable water flow output from the water storage tank 1 and achieves the first efficient conversion of rainwater energy by utilizing the potential and kinetic energy of the water flow in the initial pipe diameter. Under light rain conditions, the first-stage turbine 301 receives a low-speed, stable water flow discharged uniformly from the water tank 1. By optimizing the blade angle and angle of attack design, it can still maintain high efficiency under low-speed conditions. Under heavy rain conditions, the first-stage turbine 301 receives a high-speed water flow, and the blades can make full use of the impact force of the water flow to achieve high-efficiency energy conversion.

[0027] (2) Secondary energy replenishment The second-stage turbine 302 is located in the middle of the secondary pipe 202 and serves as the core for secondary rainwater energy collection. It receives the remaining water flow after the energy capture by the first-stage turbine 301 and uses the increased water flow velocity through the variable diameter of the secondary pipe 202 to capture the potential and kinetic energy of the rainwater that has not been fully utilized. After the water flows through the first-stage turbine 301, although some of the energy has been extracted, a considerable proportion of kinetic and potential energy is still retained. The second-stage turbine 302 uses the increased flow velocity through the variable-diameter pipe to make the water flow impact the blades at a higher speed, further extracting the energy of the water flow. The second-stage turbine 302 adopts the same standardized design as the first-stage turbine 301, which is convenient for manufacturing and maintenance, while ensuring the smooth flow of water.

[0028] (3) Final energy recovery The third-stage turbine 303 is located in the lower part of the third-stage pipe 203. As the core of the final recovery of rainwater energy, it receives the residual water flow captured by the first two turbines and maximizes the recovery of the remaining low-order energy in the water flow by relying on the final flow velocity of the variable diameter of the third-stage pipe 203. After the water flows through the first two turbine stages, its energy is significantly reduced, but some low-order energy remains. The third turbine 303, with its smaller pipe diameter and higher flow velocity, allows the residual water to impact the blades at a higher speed, effectively extracting low-order energy. The three turbine stages work together to achieve full-stage capture of rainwater energy from high to low order, effectively solving the problem of insufficient energy utilization in single-stage or two-stage turbines.

[0029] (4) Linkage control of staged turbines This multi-stage turbine is a standardized, graded design, corresponding one-to-one with the graded variable-diameter pipe 2. The blades adopt a streamlined, integrated structure with a certain force-bearing area, and can generate mechanical energy by being driven by water flow. The operating principle is similar to a waterwheel, using the impact force of water flow to rotate the blades, converting part of the kinetic energy of the water flow into the rotational mechanical energy of the turbine.

[0030] The operation of the three-stage turbine is completely synchronized, and is controlled by the water outlet conditions of water storage tank 1: Under light rain conditions: The three-stage turbine starts synchronously with the uniform drainage of water tank 1, and together captures the energy of stable low-speed water flow. Due to the low water flow speed, energy conversion is mainly achieved through the combined effect of the lift and drag effects of the blades. Under heavy rain conditions: The three-stage turbine operates at full load synchronously with the water tank 1, capturing the energy of the high-speed water flow in stages. At this time, the water flow velocity is high, and the blades are mainly driven to rotate by impact force, resulting in high energy conversion efficiency.

[0031] S4, each stage of the turbine drives the corresponding first generator 401, second generator 402 and third generator 403 to operate, converting the kinetic energy of water into electrical energy; Each turbine is directly connected to the generator, meaning the turbine and the generator rotor are coaxial. The rotation of the turbine directly drives the rotation of the generator rotor. This direct drive method avoids energy loss in intermediate transmission links and improves the overall conversion efficiency. The turbine shaft uses a waterproof sealed bearing, which can operate reliably in humid, muddy rainwater for a long time. The bearing adopts a double-layer sealing structure, with an outer rubber sealing ring and an inner mechanical seal, which effectively prevents moisture and impurities from entering and ensures long-term stable operation of the bearing. A labyrinth seal is provided between the shaft and the housing to further block water penetration. Meanwhile, the generator adopts a micro permanent magnet synchronous generator, which has the characteristics of low starting torque, high power generation efficiency and stable output characteristics. It can efficiently convert the mechanical energy of the turbine rotation into electrical energy. Each stage of power generation is independent of each other. Even if the speed of a certain stage turbine fluctuates, it will not affect the normal operation of other stages of generators, thereby improving the overall operational reliability of the device.

[0032] S5. The electrical energy output by the first generator 401, the second generator 402 and the third generator 403 is sent to the corresponding first energy storage unit 501, the second energy storage unit 502 and the third energy storage unit 503 for independent storage. The electrical energy output by each energy storage unit is then connected in parallel to the total energy storage unit 504 for convergence and unified storage, so as to realize multi-level power generation of rainwater. (1) Functions of energy storage units at all levels Each level of voltage-stabilized energy storage unit has the following functions: Rectification function: The AC power output from the generator is rectified into DC power using a three-phase bridge rectifier circuit with filter capacitors to output a smooth DC voltage. The rectifier diodes are fast recovery type, with low switching loss, and adaptable to the frequency changes of the generator output voltage. Filtering function: The LC filter circuit eliminates voltage spikes and current ripples, making the output voltage waveform smoother. The filter inductor is made of iron-silicon-aluminum magnetic core with high saturation magnetic flux density and low temperature rise. The filter capacitor is made of low ESR aluminum electrolytic capacitor, which ensures the filtering effect while having a long service life. Overvoltage protection: When the generator output voltage exceeds the set threshold, the protection circuit automatically cuts off the charging circuit to prevent the energy storage unit from being damaged by overvoltage. The overvoltage protection adopts the thyristor bypass method, which has a fast response speed and reliable protection. Overcurrent protection: When the charging current exceeds the set threshold, the protection circuit limits the current or cuts off the circuit to prevent damage to the equipment due to short circuit or excessive load. The overcurrent protection adopts dual protection of self-resetting fuse and electronic current limiting circuit. Maximum power point tracking: Under low flow conditions, by detecting the generator output voltage and current, the equivalent impedance of the load is dynamically adjusted to enable the generator to operate at the maximum power output point, thereby improving the energy capture efficiency in low flow scenarios.

[0033] (2) Function of total energy storage unit The total energy storage unit 504 performs centralized collection, secondary voltage stabilization, and unified energy storage for multiple power sources: Power consolidation: The DC power output from the three-stage voltage-stabilized energy storage unit is connected in parallel and combined. Anti-reverse-feedback diodes are used during the consolidation process to prevent mutual interference between the power levels. When the power generation of a certain stage is small or stops, the anti-reverse-feedback diodes can prevent power from flowing back into other stages, ensuring system stability. Secondary voltage regulation: The combined power is regulated in the second stage to eliminate possible voltage differences between stages and output stable and reliable DC power. It adopts a DC-DC converter and the output voltage can be set to common voltage levels such as 12V, 24V or 48V to meet the needs of different electrical equipment. Unified energy storage: The stabilized electrical energy is stored in the battery pack, which uses lead-acid batteries or lithium iron phosphate batteries. The capacity is designed according to the building's power demand and local rainfall characteristics, usually 100Ah-500Ah. The energy storage system has charge and discharge management functions to prevent overcharging and over-discharging and extend the battery life. Grid connection control: When the power generation exceeds the energy storage capacity or load demand, it automatically switches to grid connection mode to feed the excess power into the building microgrid, so as to realize the effective utilization of power.

[0034] By using a dual-efficiency energy storage model that generates electricity first and then reuses it, the dual goals of rainwater resource utilization and energy utilization are achieved, significantly improving the comprehensive utilization level of building rainwater.

[0035] The above inventions are merely a few specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A dual-effect power generation device for building rainwater utilization, comprising a water storage component, characterized in that, The water storage component includes a water storage tank installed in the water collection area of ​​the building roof. The water storage tank is provided with an inlet, an outlet and an overflow outlet. The inlet is connected to the rainwater collection channel. A graded variable diameter pipeline includes a primary pipeline, a secondary pipeline, and a tertiary pipeline connected sequentially from top to bottom with gradually decreasing diameters. The primary pipeline is connected to the outlet. A staged turbine assembly includes a first-stage turbine, a second-stage turbine, and a third-stage turbine sequentially disposed in the first-stage pipe, the second-stage pipe, and the third-stage pipe along the water flow direction; The power generation assembly includes a first generator, a second generator, and a third generator, which are respectively connected to the first-stage turbine, the second-stage turbine, and the third-stage turbine in a one-to-one correspondence. An energy storage component includes a first energy storage unit, a second energy storage unit, a third energy storage unit, and a total energy storage unit. The first energy storage unit, the second energy storage unit, and the third energy storage unit are respectively connected to the output terminals of the first generator, the second generator, and the third generator, and are connected in parallel to the total energy storage unit. An automatic switching component is located inside the water storage tank and works in conjunction with the water outlet to control the opening and closing of the water outlet. The automatic switching component is driven by the buoyancy of the water flow to achieve automatic switching between water storage and drainage in the water storage tank.

2. The energy storage dual-effect power generation device for building rainwater utilization as described in claim 1, characterized in that, The automatic switching component includes a first connecting rod and a second connecting rod disposed inside the water storage tank. The first connecting rod and the second connecting rod are arranged in a V-shape. The connecting ends of the first connecting rod and the second connecting rod are rotatably connected to the inner side wall of the water storage tank. A float ball is fixedly connected to the other end of the first connecting rod, and a stop block is fixedly connected to the other end of the second connecting rod. The stop block cooperates with the water outlet to block or release the water outlet.

3. The dual-effect power generation device for building rainwater utilization as described in claim 2, characterized in that, The angle between the first link and the second link is α, and 0° < α < 90°.

4. The energy storage dual-effect power generation device for building rainwater utilization as described in claim 2, characterized in that, The automatic switching component includes two operating modes: water storage mode and drainage mode. In the water storage mode, the float is located below the preset water level, the first and second connecting rods are stationary, and the stop block blocks the water outlet. When in drainage mode, the water level in the water tank is at a preset level. The float rises with the water level due to the buoyancy of the water flow, causing the first connecting rod and the second connecting rod to rotate. The stop block releases the water outlet.

5. The dual-effect power generation device for building rainwater utilization as described in claim 1, characterized in that, It also includes a rainwater purification system, the end of which is connected to the rainwater purification system to realize the recycling of rainwater after power generation.

6. A power generation method based on the energy storage dual-effect power generation device for building rainwater utilization as described in any one of claims 1-5, characterized in that, Includes the following steps: After rainwater is collected through the roof drainage channel, it enters the water storage tank through the inlet. The automatic switching component controls the outlet to close, and the water storage tank stores water. At this time, the water storage tank is in water storage mode. When the water tank is filled to the preset water level, it enters the drainage mode. The automatic switching component controls the opening of the water outlet. The water flows through the water outlet into the graded variable diameter pipe, and flows through the first-level pipe, the second-level pipe and the third-level pipe in sequence, gradually accelerating out. After being accelerated and flowing out, the water sequentially impacts the first-stage turbine, the second-stage turbine, and the third-stage turbine, driving the corresponding turbines to rotate. Each turbine drives the corresponding first, second, and third generators to convert the kinetic energy of the water into electrical energy. The electrical energy output by the first, second, and third generators is sent to the corresponding first, second, and third energy storage units for independent storage. The electrical energy output by each energy storage unit is then connected in parallel to the main energy storage unit for convergence and unified storage, realizing multi-stage power generation from rainwater.

7. The power generation method as described in claim 6, characterized in that, When the water storage tank is in water storage mode, the following steps are included: When the float is below the preset water level, the first and second connecting rods are stationary, the stop block blocks the water outlet, and water is stored inside the water tank. When the water storage tank is in drainage mode, the following steps are included: After the water tank is filled to the preset water level, the float rises with the water level due to the buoyancy of the water flow, causing the first and second connecting rods to rotate. The second connecting rod drives the stop block away from the outlet, at which point the outlet is released to drain water. When the water tank is in the drainage mode, the stop block remains open, and the water flows directly downstream through the outlet.

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