A hydroelectric power generation device suitable for low head environments

Abstract

The utility model discloses a kind of hydraulic power generation devices suitable for low water head environment.The drainage shell of the device is equipped with adjustable water inlet channel and pressure chamber, water wheel assembly is located in pressure chamber, its blade group unique design includes arc blade, fixed rod and water pass hole, blade radian gradually changes, inclination angle is different, water wheel turntable is connected speed increaser and generator.Implementation method includes adjusting water inlet channel opening degree water diversion flow impact water wheel assembly, and power generation by generator after the speed of speed increaser is promoted.The device also relates to the specific installation, processing and water quality detection filtration of component and the like measures.The utility model effectively improves low water head water flow energy utilization efficiency, enhances device stability and reliability, optimizes performance, adapts to a variety of water quality environment.

Description

Technical Field

[0001] This utility model relates to the field of hydropower generation in low-head environments, specifically a hydropower generation device suitable for low-head environments. Background Technology

[0002] With the growing global demand for clean energy, hydropower has received widespread attention as a renewable energy source. However, traditional hydropower plants often rely on high head differences to achieve efficient power generation, resulting in lower efficiency in low-head environments. In many regions, low-head water resources are abundant, but these resources remain underutilized due to a lack of suitable power generation technologies and equipment.

[0003] Existing low-head hydropower generation devices suffer from numerous problems. For example, some devices have inadequate flow guidance structures, failing to effectively collect and control the water flow, resulting in unstable and difficult-to-regulate water flow into the power generation unit, thus affecting power generation efficiency. Some turbine components are not optimally designed; their blade structures and layouts are not well adapted to the characteristics of low-head water flow, leading to low energy conversion efficiency. Furthermore, during long-term operation, these devices are susceptible to water corrosion and wear from impurities, resulting in a short service life and high maintenance costs. These problems limit the widespread application and development of low-head hydropower technology. Utility Model Content

[0004] The purpose of this invention is to provide a hydroelectric power generation device suitable for low-head environments, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a protective structure for preventing collisions and scratches on load-bearing columns of factory buildings, and a hydroelectric power generation device suitable for low-head environments, comprising... The diversion shell serves as the water flow guiding structure for the entire device, and its main function is to effectively introduce low-head water flow into the power generation area. The diversion shell has an inlet channel and an outlet channel. The inlet channel is specifically located at the low-head water source and has an adjustable diversion opening. This adjustable design allows for precise control of the water flow entering the device based on actual water flow conditions and power generation requirements. Simultaneously, a pressure chamber is located in the middle of the diversion shell, providing a specific spatial environment for the subsequent installation and operation of the turbine components. The water turbine assembly is installed inside the pressure chamber in the middle of the diversion shell. It includes a central water turbine disc and blades evenly arranged on the disc. The side of the water turbine assembly is tightly fitted to the arc-shaped inner wall of one side of the pressure chamber. This design ensures the stability of the water turbine assembly during operation and the effectiveness of the water flow impact. The blade assembly consists of three sets of arc-shaped blades, with a fixing rod at the rear end of each blade to secure it to the water turbine disc. The bottom of the upper two sets of blades has interconnected water passage holes. This design facilitates water flow between the blade sets, reduces water flow resistance, and improves the working efficiency of the water turbine assembly. The arc-shaped structure has a gradually changing curvature from the root to the tip of the blade. This special curvature design can better adapt to the impact of water flow and improve the blade's ability to capture water flow energy. The rotating shaft of the turbine disc extends out of the guide shell and connects to the speed increaser. After the speed increaser further increases the speed, it is connected to the generator, which finally converts mechanical energy into electrical energy. The three sets of blades are vertically inclined and fixed to the side wall of the fixed rod. The blades fixed in the middle are inclined at 20-30 degrees, while the blades at the bottom are inclined at 40-45 degrees. This inclination design at different angles allows the blade group to efficiently utilize water flow energy at different water layers, improving the energy conversion efficiency of the entire turbine assembly.

[0006] Furthermore, the water inlet trough is located at a low-head water source and has an adjustable flow opening. The flow opening of the water inlet trough is adjusted by a sliding baffle structure. The sliding baffle is located at the water inlet trough and can be slid along a specific track by a manual or electric control device, thereby changing the opening size of the water inlet trough. A sealing device is provided at the contact edge between the sliding baffle and the flow housing. This sealing device can be made of rubber sealing strips or silicone sealing strips, which are flexible sealing materials. The sealing device is installed by embedded installation, that is, the sealing material is embedded into a pre-processed groove on the baffle or the flow housing.

[0007] Furthermore, the anti-corrosion coating on the inner wall of the pressure chamber is an epoxy resin coating. Before applying the epoxy resin coating, the inner wall of the pressure chamber needs to be pretreated. First, the inner wall surface is derusted, which can be done by sandblasting or mechanical grinding to ensure that the inner wall surface is free of rust, oil, and other impurities. Then, the surface is cleaned by wiping the inner wall surface with a cleaning solvent such as acetone or ethanol. After the surface is dry, the coating is applied. The epoxy resin coating is applied by spraying or brushing, and the coating thickness is controlled between 0.3-0.5 mm. After coating, curing is performed. The curing conditions are based on the product instructions for the epoxy resin coating, generally curing at room temperature for 24-48 hours, or shortening the curing time under appropriately increased temperature conditions. The epoxy resin coating has excellent corrosion resistance and can effectively resist the corrosion of the inner wall of the pressure chamber by acidic and alkaline substances in the water flow and dissolved oxygen in the water, thereby extending the service life of the pressure chamber, ensuring long-term stable operation of the device, and reducing maintenance and replacement costs caused by corrosion.

[0008] Furthermore, the fixing rod and the blade are connected by welding. During welding, welding materials suitable for the blade and fixing rod materials are selected. For example, aluminum alloy welding wire can be used for aluminum alloy blades and aluminum alloy fixing rods. The welding process adopts argon arc welding, so that the surface of the weld is flush with the surface of the blade and the fixing rod and has a smooth transition. This treatment method not only ensures the connection between the fixing rod and the blade and prevents the blade from falling off during the high-speed operation of the turbine assembly, but also makes the surface smooth by grinding, reducing the turbulence and resistance of the water flow at the connection, which is conducive to improving the overall performance of the turbine assembly.

[0009] Furthermore, the speed increaser is a planetary gear speed increaser; the planetary gear speed increaser mainly consists of a sun gear, planet gears, an internal gear ring, and a planet carrier; the sun gear is located at the center and connected to the rotating shaft extending from the water turbine turntable; the planet gears are evenly distributed around the sun gear and mesh with the sun gear and the internal gear ring; the planet carrier is used to support the planet gears and output power; the transmission principle of the planetary gear speed increaser is based on the motion characteristics of the planetary gear system, and a high transmission ratio can be achieved by reasonably designing the gear ratio of each gear.

[0010] Furthermore, the generator is a permanent magnet synchronous generator; the rotor of the permanent magnet synchronous generator is made of permanent magnet material; the stator is composed of an iron core and windings, the iron core is made of high-quality silicon steel sheets laminated together to reduce hysteresis losses; the windings are made of copper wire, and the number of turns, wire diameter and connection parameters of the windings are determined according to the design requirements of the generator; the working principle of the permanent magnet synchronous generator is based on the law of electromagnetic induction. When the turbine assembly drives the generator rotor to rotate, the magnetic field generated by the permanent magnet of the rotor moves relative to the stator windings, thereby generating an induced electromotive force in the stator windings; since the magnetic field of the permanent magnet synchronous generator is provided by the permanent magnet, no external excitation power supply is required. Beneficial effects

[0011] The inlet housing of this invention features an adjustable inlet channel opening, enabling precise control of the water flow rate based on actual water flow conditions, thus allowing low-head water to more effectively impact the turbine assembly. The blade assembly within the turbine employs a special design, with three sets of arc-shaped blades vertically inclined at different angles, maximizing the utilization of water flow energy at different water levels. The arc structure and gradually varying curvature of the blades, along with the water passage holes at the bottom of the upper blades, all contribute to enhancing the blades' ability to capture water flow energy, reducing water flow resistance, and thereby improving the overall energy conversion efficiency of the turbine assembly. This allows the device to achieve high power generation efficiency even in low-head environments.

[0012] The turbine assembly's sides conform to the curved inner wall of the pressure chamber, ensuring its stability during operation and allowing it to better withstand water flow impacts. The blades are welded to the fixing rods and then ground to ensure a secure connection, preventing blade detachment during high-speed operation and reducing water flow turbulence and resistance. The inner wall of the pressure chamber is coated with an epoxy resin anti-corrosion coating, effectively resisting water flow corrosion, extending the pressure chamber's service life, and reducing maintenance and replacement costs due to corrosion. These measures collectively improve the long-term stability and reliability of the system.

[0013] The turbine turntable is made of high-strength aluminum alloy, which is lightweight and high-strength, reducing rotational inertia for easier starting and acceleration, while also withstanding significant torque to ensure long-term operation without deformation or damage. The speed increaser uses a planetary gear speed increaser, offering high transmission efficiency and a compact structure, effectively increasing the turbine turntable's speed. The generator is a permanent magnet synchronous generator, boasting high power generation efficiency, stable operation, and no need for an external excitation power supply, with excellent output voltage and frequency stability. The blade surface is a smooth curved surface with low roughness, reducing water flow friction and cavitation, improving the turbine assembly's rotational efficiency, and extending blade lifespan, thus optimizing the overall performance of the device in multiple ways.

[0014] The implementation method includes testing the water quality of low-head water sources, and a multi-stage filtration system can be installed before the inlet tank depending on the water quality. This filtration system can effectively remove suspended solids, colloids, bacteria, viruses and other impurities from the water, preventing impurities from entering the device and causing damage such as wear, corrosion or blockage to various components. This ensures the normal operation of the hydroelectric power generation device under different water quality environments, extends the service life of the device, and also helps maintain power generation efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the installation of the water turbine assembly of this utility model; Figure 2 This is a schematic diagram of the drainage shell of this utility model; Figure 3This is a three-dimensional schematic diagram of the drainage shell of this utility model; Figure 4 This is the utility model Figure 2 Schematic diagram of the AA section; Figure 5 This is the utility model Figure 2 Diagram of BB in the middle; Figure 6 This is a schematic diagram of the water turbine assembly of this utility model; Figure 7 This is a schematic diagram of the blade assembly of this utility model.

[0016] In the diagram: 1. Drainage shell; 2. Inlet tank; 3. Pressure chamber; 4. Outlet tank; 5. Water turbine assembly; 51. Water turbine turntable; 52. Blade assembly; 521. Blade; 522. Fixing rod; 523. Water passage hole; 6. Cover. Detailed Implementation

[0017] Please see Figure 1-7 This utility model provides a technical solution: a hydroelectric power generation device and its implementation method suitable for low-head environments. The inlet shell 1 is made of high-strength, corrosion-resistant 304 stainless steel. The plate is cut using laser cutting technology, resulting in smooth, flat edges with dimensional accuracy controlled within ±0.5mm. During bending, the bending angle error does not exceed ±0.5°. The dimensional accuracy of the openings in the inlet tank 2 and outlet tank 4 is controlled within ±1mm.

[0018] In the adjustable drainage opening structure of the water inlet trough 2, the sliding baffle track is made of aluminum alloy and is fixed to the drainage housing 1 with M8 bolts. The bolt tightening torque is controlled at 12 N·m. The sliding baffle is made of 3mm thick 304 stainless steel plate with a galvanized surface for rust prevention. The slider between the baffle and the track is made of polytetrafluoroethylene and has dimensions of 20mm × 30mm × 10mm. The rubber sealing strip has an embedding depth of 5mm and a width of 8mm. The screw of the manual control device is made of M10 stainless steel with a pitch of 2mm. Rotating the screw can precisely adjust the position of the baffle, with an adjustment accuracy of ±1mm. The motor power of the electric control device is 0.5kW, the reducer reduction ratio is 50:1, the transmission chain is a 10A model, and the position sensor accuracy is 0.1mm.

[0019] The pressure chamber 3 is welded to the middle of the drainage shell 1 using argon arc welding with a welding current of 150A, a voltage of 18V, and a welding speed of 8mm / s. The weld seams are inspected for defects such as porosity and cracks. For the pretreatment of the inner wall of the pressure chamber 3, sandblasting is performed at a pressure of 0.4MPa using 40-mesh quartz sand, achieving a surface roughness of 3.2μm. The inner wall surface is wiped twice with acetone solvent, with a 10-minute interval between each wipe. The epoxy resin coating is applied using a high-pressure airless sprayer at a pressure of 0.6MPa, a nozzle distance of 20cm from the inner wall surface, and a spray gun movement speed of 30cm / s. The coating is applied in two coats, each with a thickness controlled between 0.2-0.3mm, for a total thickness of 0.3-0.5mm. After coating, it is cured at room temperature for 48 hours, with good ventilation maintained during the curing process.

[0020] The foundation for the drainage casing 1 is constructed using C30 concrete, with dimensions of 2000mm × 1500mm × 1000mm and a depth of 1.2m. M20 anchor bolts are used, embedded to a depth of 0.8m, with 50mm protruding from the foundation surface. The drainage casing 1 is connected to the foundation using these anchor bolts, with a tightening torque of 200 N·m. After installation, the levelness of the drainage casing 1 is checked using a level, and the levelness error should not exceed ±0.2°.

[0021] The water turbine turntable 51 is made of 6061-T6 aluminum alloy. During raw material smelting, the temperature in the medium-frequency induction furnace is controlled at 750℃, with appropriate amounts of refining and modifying agents added, and the refining time is 30 minutes. The surface roughness of the gravity casting mold cavity is 1.6μm, resulting in the water turbine turntable 51 blank. During machining, the external turning parameters on the lathe are: cutting speed 150m / min, feed rate 0.2mm / r, depth of cut 1mm, achieving an external diameter accuracy of ±0.05mm and a flatness error not exceeding ±0.02mm. The keyway milling parameters on the milling machine are: cutting speed 120m / min, feed rate 0.1mm / z, depth of cut 2mm, achieving a keyway width accuracy of ±0.03mm. The drilling machine achieves a drilling diameter accuracy of ±0.1mm, with positional accuracy controlled within ±0.1mm. During heat treatment, the solution treatment temperature is 530℃ and the holding time is 3 hours, and the aging treatment temperature is 180℃ and the holding time is 5 hours.

[0022] The blades 521 of blade assembly 52 are manufactured using precision casting technology, with a lost-wax casting mold manufacturing accuracy of ±0.1mm. The casting material is ZL104 aluminum alloy, with a melting temperature of 720℃, a pouring temperature of 680℃, and a pouring speed of 1kg / s. For surface grinding and polishing of blade 521, it is first coarsely ground with 80-grit sandpaper, then finely ground with 180-grit, 320-grit, and 600-grit sandpaper in sequence, and finally mirror-polished with polishing paste. The fixing rod 522 is made of 12mm diameter 304 stainless steel round bar. The blades 521 and fixing rod 522 are welded together using argon arc welding with a welding current of 120A, a voltage of 15V, and a welding speed of 6mm / s. After welding, the weld joint is ground to make its surface flush and smooth with the surfaces of blade 521 and fixing rod 522. The water passage holes 523 at the bottom of the two upper blades 521 are drilled with an 8mm diameter drill bit. The drilling position accuracy is controlled within ±0.5mm. The drilling machine is used for processing. After processing, the inner wall of the water passage hole 523 is deburred.

[0023] The rotating shaft of the water turbine turntable 51 is mounted on the two side walls of the pressure chamber 3 via bearing seats. 6205 deep groove ball bearings are used. The bearings are installed using a heat-fit method, with a heating temperature of 100℃ and a heating time of 10 minutes. After installation, check the rotational flexibility of the water turbine assembly 5. Manually rotate the water turbine turntable 51; it should rotate smoothly without any jamming. Simultaneously check the gap between the blades 521 and the inner wall of the pressure chamber 3; the gap should be uniform, with a minimum gap of not less than 3mm.

[0024] The speed increaser is a planetary gear speed increaser. Based on the rotational speed range of the water turbine turntable 51 (20-80 rpm) and the required input speed of the generator (1500 rpm), the transmission ratio of the planetary gear speed increaser is designed to be 75. The sun gear, planet gears, and internal gear ring are all made of high-quality 20CrMnTi alloy steel.

[0025] The planetary gear speed increaser is assembled in a clean assembly workshop. Before assembly, all parts are cleaned and inspected to remove oil and impurities, and the meshing of gears and bearing clearance are checked. During assembly, the sun gear is interference-fitted with the input shaft with an interference amount of 0.08mm. The sun gear is heated to 150℃ before assembly. The rolling bearings between the planetary gears and the planetary carrier are model 6204, and an appropriate amount of high-temperature lithium-based grease is applied during installation. The internal gear ring is connected to the housing with M12 bolts, with a bolt tightening torque of 100 N·m. After connection, the meshing clearance between the internal gear ring and the planetary gears is checked; the clearance should be uniform, between 0.1-0.3mm. After assembly, the speed increaser undergoes a no-load test run for 2 hours, with the vibration acceleration not exceeding 5 m / s².

[0026] The generator is a permanent magnet synchronous generator, using neodymium iron boron permanent magnets with a remanence of 1.2T and a coercivity of 900kA / m. The stator core is made of 0.5mm thick 50W470 silicon steel sheets, with a stacking factor of 0.95. The windings are made of 1.5mm diameter enameled wire, with the number of turns determined according to the generator design requirements, and a star connection.

[0027] The generator is installed at the output end of the speed increaser and connected to the speed increaser via a flexible coupling. The torsional stiffness of the coupling is 1000 N·m / rad, and the axial movement does not exceed 0.5 mm. During installation, a dial indicator is used to check the coaxiality of the generator and the speed increaser; the coaxiality error should not exceed 0.1 mm. The generator casing is grounded, and no-load and load tests are performed. During the no-load test, the generator's output voltage and frequency are checked; voltage fluctuation should not exceed ±5%, and frequency fluctuation should not exceed ±0.5 Hz. During the load test, the load is gradually increased, and the generator's output power, efficiency, and temperature rise are checked to ensure that the generator can operate stably under rated load, with an efficiency of not less than 85% and a temperature rise not exceeding 80℃.

[0028] The design of blade 521 with a surface roughness of no more than 0.8 micrometers is achieved through the aforementioned precision casting and CNC machining followed by polishing. In actual operation, the smooth blade surface reduces the frictional resistance of water flow on the blade surface by approximately 30%. When the water flow velocity is 2 m / s, tests show that the water flow separation point on the smooth blade surface is significantly shifted backward, reducing the turbulent flow area and thus improving the rotational efficiency of the turbine assembly 5 by approximately 15%. Simultaneously, the smooth surface increases the critical pressure for cavitation on the blade 521 surface by approximately 20%, effectively reducing the probability of cavitation and extending the service life of blade 521 by approximately 2-3 years.

[0029] The curved structure of blade 521, with its gradually changing curvature from the blade root to the tip, was optimized through hydrodynamic simulation and actual experiments. The root radius of curvature is 150 mm, and the tip radius is 250 mm. This curvature design allows blade 521 to better adapt to changes in water flow velocity and direction at different water layers. In low-head flows, blade 521 can more effectively capture water flow energy, improving energy conversion efficiency by approximately 10%-15%.

[0030] Water quality testing employs a multi-parameter water quality analyzer to measure indicators such as pH, dissolved oxygen, conductivity, turbidity, and suspended solids in the water source. A comprehensive test is conducted before the initial installation and operation of the system, followed by weekly spot checks. If the test results show that the suspended solids content exceeds 50 mg / L, or the pH value is outside the range of 6.5-8.5, indicating that the water quality does not meet requirements, a filtration device must be installed before inlet tank 2.

[0031] The coarse filtration stage uses a mesh filter with a mesh size of 0.8mm, determined based on the size of larger particles in the water source. The filter housing is made of 304 stainless steel and measures 500mm × 300mm × 200mm. The fine filtration stage uses a polypropylene melt-blown cartridge filter with a 10-micron pore size, a cartridge diameter of 100mm, and a length of 500mm. Ultrafiltration utilizes an ultrafiltration membrane module with a molecular weight cutoff of 50,000 Daltons and a membrane module area of ​​10m². During installation, the filters are connected by UPVC pipes with a diameter of 50mm, using flange connections with a tight seal. The filtration system should be cleaned and the filter cartridges replaced regularly. The coarse filter mesh should be cleaned weekly, the fine filter cartridge replaced every two months, and the ultrafiltration membrane chemically cleaned every six months.

Claims

1. A hydroelectric power generation device suitable for low-head environments, characterized in that: Includes: a diversion shell (1): the diversion shell (1) serves as the water flow guiding structure for the entire device, effectively introducing low-head water flow into the power generation area; the diversion shell (1) has an inlet tank (2) and an outlet tank (4), the inlet tank (2) is located at the low-head water source, and it has an adjustable diversion opening to precisely control the water flow rate entering the device. Meanwhile, a pressure chamber (3) is provided in the middle of the diversion shell (1), which provides a space environment for the subsequent installation and operation of the turbine assembly (5); Water turbine assembly (5): The water turbine assembly (5) is installed inside the pressure chamber (3) in the middle of the diversion shell (1). It includes a water turbine turntable (51) in the middle and blade groups (52) evenly arranged on the water turbine turntable (51). The side of the water turbine assembly (5) is closely attached to the arc-shaped inner wall of one side of the pressure chamber (3). This design ensures the stability of the water turbine assembly (5) during operation and the effectiveness of water flow impact. The blade group (52) is composed of three sets of arc-shaped blades (521). A fixing rod (522) is provided at the rear end of the blade (521). The fixing rod (522) is used to fix the blade (521) on the water turbine turntable (51). In addition, water passage holes (523) are opened at the bottom of the two sets of blades (521) above. The design of this water passage hole (523) is conducive to the flow of water between the blade groups (52), reducing water flow resistance and improving the working efficiency of the water turbine assembly (5). The blade (521) has an arc-shaped structure with a gradually changing curvature from the root to the tip of the blade. The curvature design can better adapt to the impact of water flow and improve the blade (521)’s ability to capture water flow energy. The water turbine turntable (51) extends out of the shaft of the diversion shell (1) and connects to the speed increaser. After the speed increaser further increases the speed, it is connected to the generator, and finally the generator converts mechanical energy into electrical energy. The three sets of blades (521) are vertically inclined and fixed on the side wall of the fixed rod (522), and the blade (521) fixed in the middle is inclined at 20-30 degrees, while the blade (521) below is inclined at 40-45 degrees.

2. A hydroelectric power generation device suitable for low-head environments according to claim 1, characterized in that: The water inlet trough (2) is located at a low water head source and has an adjustable flow opening. The flow opening of the water inlet trough (2) is adjusted by a sliding baffle structure. The sliding baffle is located at the water inlet trough (2). The baffle can be slid along a specific track by a manual or electric control device, thereby changing the opening size of the water inlet trough (2). A sealing device is provided at the contact edge between the sliding baffle and the flow housing (1). This sealing device can be made of rubber sealing strip or silicone sealing strip flexible sealing material. The sealing device is installed by embedded installation, that is, the sealing material is embedded in the groove pre-processed on the baffle or flow housing (1).

3. A hydroelectric power generation device suitable for low-head environments according to claim 1, characterized in that: The speed increaser is a planetary gear speed increaser; the planetary gear speed increaser is mainly composed of a sun gear, planet gears, an internal gear ring and a planet carrier; the sun gear is located in the center and is connected to the rotating shaft extending from the water turbine turntable (51); the planet gears are evenly distributed around the sun gear and mesh with the sun gear and the internal gear ring; the planet carrier is used to support the planet gears and output power; the generator is a permanent magnet synchronous generator; the rotor of the permanent magnet synchronous generator is made of permanent magnet material; the stator is composed of an iron core and windings; the iron core is made of high-quality silicon steel sheets to reduce hysteresis loss; the windings are made of copper wire.

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