Hydroelectric power generation device suitable for low water head environment and implementation method of hydroelectric power generation device

Abstract

The invention discloses a hydroelectric generation device suitable for a low water head environment and an implementation method. A drainage shell of the device is provided with an adjustable water inlet groove and a pressure bin, a water wheel assembly is located in the pressure bin, a blade set of the device is uniquely designed and comprises arc-shaped blades, fixing rods and water passing holes, the radians of the blades are gradually changed, the inclination angles of the blades are different, and a water wheel rotating disc is connected with a speed increaser and a generator. The implementation method comprises the steps of adjusting the opening degree of the water inlet tank to guide water flow to impact the water wheel assembly, and generating power by the generator after increasing the rotating speed by the speed increaser. The device also relates to measures such as specific installation and treatment of components, water quality detection and filtration and the like. The energy utilization efficiency of low-water-head water flow is effectively improved, the stability and reliability of the device are enhanced, the performance is optimized, and the device adapts to various water quality environments.

Description

Technical Field

[0001] The present invention relates to the field of hydropower generation in a low water head environment, and in particular to a hydropower generation device suitable for a low water head environment and an implementation method thereof. Background Art

[0002] As the global demand for clean energy continues to grow, hydropower has attracted widespread attention as a renewable energy utilization method. However, traditional hydropower generation devices often rely on a high head drop to achieve efficient power generation, and have low utilization efficiency in low head environments. In many areas, low head water resources are abundant, but due to the lack of suitable power generation technology and equipment, these resources have not been fully utilized.

[0003] There are many problems with some existing low-head hydroelectric power generation devices. For example, the water flow guiding structure of some devices is unreasonable, and the water flow cannot be effectively gathered and controlled, resulting in unstable and difficult-to-adjust water flow entering the power generation device, affecting the power generation efficiency. The design of some water wheel components is not optimized enough, and the blade structure and layout cannot adapt well to the characteristics of low-head water flow, resulting in low energy conversion efficiency. In addition, during long-term operation, the device is easily affected by water flow corrosion, impurity wear, etc., with a short service life and high maintenance costs. These problems limit the widespread application and development of low-head hydroelectric power generation technology. Summary of the invention

[0004] The object of the present invention is to provide a hydroelectric power generation device suitable for low head environment and an implementation method thereof, so as to solve the problems raised in the above background technology.

[0005] To achieve the above purpose, the present invention provides the following technical solutions: a protective structure for preventing collision and scratching of load-bearing columns of a plant, a hydroelectric power generation device suitable for a low water head environment, comprising: Drainage shell: The drainage shell is the water flow guiding structure of the whole device, and its main function is to effectively introduce low-head water flow into the power generation area; the drainage shell has an inlet trough and an outlet trough, and the inlet trough is specially arranged at the low-head water source, and it has an adjustable drainage opening. Through this adjustable design, the water flow entering the device can be accurately controlled according to the actual water flow conditions and power generation needs; at the same time, a pressure chamber is opened in the middle of the drainage shell, and this pressure chamber provides a specific space environment for the installation and operation of the subsequent water wheel assembly; Water wheel assembly: The water wheel assembly is installed inside the pressure chamber in the middle of the drainage shell, and includes a water wheel turntable in the middle and a blade group evenly arranged on the water wheel turntable; the side of the water wheel assembly is tightly fitted to the arc-shaped inner wall on one side of the pressure chamber, and this design ensures the stability of the water wheel assembly during operation and the effectiveness of water flow impact; the blade group is composed of three groups of arc-shaped blades, and a fixing rod is provided at the rear end of the blade, and the blade is fixed to the water wheel turntable through the fixing rod; and interconnected water holes are provided at the bottom of the two upper groups of blades. The design of this water hole is conducive to the circulation of water between the blade groups, reduces water flow resistance, and improves the working efficiency of the water wheel assembly; the blades The arc-shaped structure has a gradual curvature from the root of the blade 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 water wheel turntable extending out of the drainage shell is connected to the speed increaser, and the speed is further increased by the speed increaser and then connected to the generator, and finally the generator converts the mechanical energy into electrical energy; the three groups of blades are vertically tilted and fixed on the side wall of the fixed rod, and the middle fixed blade is tilted 20-30 degrees, while the lower blade is tilted 40-45 degrees. This inclination design at different angles enables the blade group to efficiently utilize water flow energy at different water layer positions, thereby improving the energy conversion efficiency of the entire water wheel assembly.

[0006] Furthermore, the water inlet trough is arranged at a low-head water source and has an adjustable drainage opening. The drainage opening adjustment method of the water inlet trough adopts a sliding baffle structure. The sliding baffle is arranged at the water inlet trough. The baffle can be slid along a specific track through 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 of the sliding baffle and the drainage shell. This sealing device can choose a rubber sealing strip or a silicone sealing strip flexible sealing material. The installation method of the sealing device is embedded installation, that is, the sealing material is embedded in a pre-processed groove on the baffle or the drainage shell.

[0007] Furthermore, the anti-corrosion coating applied to the inner wall of the pressure vessel is an epoxy resin coating; before applying the epoxy resin coating, the inner wall of the pressure vessel needs to be pretreated; first, the inner wall surface is derusted, and sandblasting or mechanical grinding can be used to ensure that the inner wall surface is free of rust, oil stains and other impurities; then, the surface is cleaned, and the inner wall surface is wiped with a cleaning solvent such as acetone or ethanol, and the coating is applied after the surface is dry; the epoxy resin coating is applied by spraying or brushing, and the coating thickness is controlled between 0.3-0.5 mm; after the coating is completed, it is cured, and the curing conditions are carried out according to the product instructions of the epoxy resin coating, generally curing at room temperature for 24-48 hours, or shortening the curing time under appropriately elevated temperature conditions; the epoxy resin coating has excellent corrosion resistance, and can effectively resist the corrosion of the inner wall of the pressure vessel by acid and alkali substances in the water flow and dissolved oxygen in the water, thereby extending the service life of the pressure vessel, ensuring the long-term stable operation of the device, and reducing the maintenance and replacement costs caused by corrosion.

[0008] Furthermore, the fixing rod and the blades are connected by welding. When welding, welding materials suitable for the materials of the blades and the fixing rods are selected. For example, for aluminum alloy blades and aluminum alloy fixing rods, aluminum alloy welding wires can be selected. The welding process adopts argon arc welding to make the surface of the weld flush with the surface of the blades and the fixing rod and the transition is smooth. This processing method not only ensures the firmness of the connection between the fixing rod and the blades, prevents the blades from falling off during the high-speed operation of the water wheel assembly, but also makes the surface smooth by grinding, reduces the turbulence and resistance of the water flow at the connection, and is beneficial to improving the overall performance of the water wheel assembly.

[0009] Furthermore, the speed increaser is a planetary gear speed increaser; the planetary gear speed increaser is mainly composed of a sun gear, planetary gears, an inner gear ring and a planetary carrier component; the sun gear is located at the center and is connected to the rotating shaft extending from the water wheel turntable, the planetary gears are evenly distributed around the sun gear and mesh with the sun gear and the inner gear ring, and the planetary carrier is used to support the planetary 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 higher transmission ratio can be achieved by reasonably designing the tooth 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 a winding, and the iron core is made of high-quality silicon steel sheets stacked to reduce hysteresis loss; the winding is wound with copper wire, and the number of turns, wire diameter and connection method parameters of the winding 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 water wheel assembly drives the generator rotor to rotate, the magnetic field generated by the rotor permanent magnet moves relative to the stator winding, thereby generating an induced electromotive force in the stator winding; since the magnetic field of the permanent magnet synchronous generator is provided by the permanent magnet, no external excitation power supply is required.

[0011] A method for implementing a hydroelectric power generation device suitable for a low head environment comprises the following steps: S1: Installation of drainage housing and adjustment of water inlet trough The drainage shell is accurately placed at the low-head water source to ensure that its position is stable and can receive water flow to the greatest extent; after the drainage shell is placed, the drainage opening of the water inlet trough is adjusted; during the adjustment, according to the actual water flow size, water flow speed and power required by the current power generation device of the low-head water source, the opening size of the water inlet trough is changed through the corresponding adjustment device, so as to achieve accurate control of the water flow entering the pressure chamber inside the drainage shell; during the adjustment process, the water flow condition can be monitored in real time with the help of water flow measuring instruments and other equipment to achieve the best drainage effect, so that the low-head water flow can stably and effectively enter the pressure chamber; S2: Water wheel assembly drive and speed increaser operation When the drainage opening of the water inlet trough is adjusted, the water flows into the pressure chamber and impacts the blade group of the water wheel assembly at a certain speed and pressure; due to the arc structure and specific inclination angle of the blades, the water flow exerts a force on the blades, so that the blades drive the water wheel turntable to rotate; during the rotation of the water wheel turntable, the rotating shaft extending out of the drainage housing transmits power to the speed increaser; after receiving the power from the water wheel turntable, the speed increaser uses its internal gear transmission mechanism or other speed increase principles to increase the speed of the water wheel turntable to a speed range suitable for the operation of the generator, thereby ensuring the efficient operation of the subsequent power generation process; S3: Mechanical energy is converted into electrical energy output The power after the speed is increased by the speed increaser is transmitted to the generator. The rotor inside the generator begins to rotate under the drive of the power, and its internal magnetic field moves relative to the winding, thereby generating induced electromotive force in the winding; according to the principle of electromagnetic induction, this induced electromotive force will prompt current to flow in the winding, realizing the conversion of mechanical energy into electrical energy; the converted electrical energy is output through the output end of the generator and can be connected to external power equipment or power grid to provide power supply to users; during the whole process, the output electrical energy of the generator can be monitored by corresponding monitoring equipment to ensure the normal operation of the power generation device and the power quality.

[0012] Furthermore, the surface of the blade is a smooth curved surface, and its processing technology adopts precision casting or CNC machining; in the precision casting process, a high-precision mold is used to ensure the accuracy of the blade surface shape, and the surface is ground and polished after casting so that the surface roughness reaches the requirement of no more than 0.8 microns; if CNC machining is adopted, advanced CNC machining equipment is used to perform precise cutting according to a pre-designed blade surface model, and after the machining is completed, a detailed grinding and polishing process is also performed; the design of the blade surface roughness being no more than 0.8 microns can significantly reduce the friction resistance of water flow on the blade surface; when the water flow impacts the blade, the smooth surface enables the water flow to flow through the blade more smoothly, reducing energy loss and improving the rotation efficiency of the water wheel assembly; at the same time, the smooth surface can also reduce the probability of cavitation on the blade surface, further protect the blade from damage, extend the service life of the blade, thereby improving the reliability and economy of the entire hydropower generation device.

[0013] Furthermore, the water wheel turntable is made of high-strength aluminum alloy material; the high-strength aluminum alloy material improves its strength and hardness through a reasonable ratio of alloy elements, such as adding copper, magnesium, and silicon elements, and undergoing a specific heat treatment process; in the material preparation process, the raw materials are first smelted to ensure that the elements are evenly distributed, and then cast or forged to obtain a blank of the water wheel turntable; the blank is machined through mechanical processing, such as turning, milling, and drilling processes, to achieve the dimensional accuracy and shape accuracy required by the design; the advantage of using high-strength aluminum alloy material for the water wheel turntable is that it is light in weight, and compared with traditional cast iron or steel water wheel turntables, it can effectively reduce the rotational inertia of the water wheel assembly, making the water wheel assembly easier to start and accelerate; at the same time, the high-strength aluminum alloy has high strength, can withstand the impact of water flow and the torque transmitted by the blades, and ensure that the water wheel turntable will not be deformed or damaged during long-term operation, thereby improving the reliability and stability of the water wheel assembly and extending the service life of the entire hydropower generation device.

[0014] Furthermore, in step S1, the method for detecting the water quality of the low-head water source is as follows: a multi-parameter water quality detector is used to detect the pH, dissolved oxygen, conductivity, turbidity, and suspended matter indicators in the water source; the detection frequency can be determined according to the stability of the water source and the actual situation, generally a comprehensive detection is carried out before the initial installation and operation of the device, and then regular sampling is carried out, such as weekly or monthly sampling; if the test results show that the water quality does not meet the requirements, for example, the suspended matter content in the water is too high and the pH value exceeds the normal range, a filtering device needs to be installed before the water inlet tank; the filtering device can select a multi-stage filtration system, including coarse filtration, fine filtration and ultrafiltration links; the coarse filtration adopts a screen filter, and the pore size of the screen is determined according to the size of larger particle impurities in the water source, generally between 0.5-1 mm, which is used to remove impurities in the water. Large suspended matter, floating objects and sediment; fine filtration can choose filter element filter, the filter element material is polypropylene melt-blown filter element or folded filter element, the filter element pore size is between 5-20 microns, which can further remove smaller particulate impurities in the water; ultrafiltration uses ultrafiltration membrane components, the retention molecular weight of ultrafiltration membrane is generally between 1000-100000 Daltons, which can effectively remove colloids, bacteria, viruses and tiny impurities in the water; by setting up such a filtering device, it can ensure that the water flow entering the drainage shell is clean, prevent impurities from entering the device and causing wear, corrosion or blockage damage to the water wheel assembly, speed increaser, and generator parts, thereby ensuring the normal operation of the hydropower generation device, extending the service life of the device and improving the power generation efficiency; at the same time, the filter device is cleaned or the filter element is replaced regularly to maintain its filtering effect.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The drainage housing of the present invention has an adjustable water inlet drainage opening, which can accurately control the water flow according to the actual water flow conditions, so that the low-head water flow can more effectively impact the water wheel assembly. The blade group in the water wheel assembly adopts a special design, and the three groups of arc-shaped blades are vertically inclined with different angles, which can efficiently utilize the water flow energy at different water layer positions. The arc-shaped structure and gradual bending arc of the blades, as well as the water hole design at the bottom of the upper blade, all help to improve the blade's ability to capture water flow energy and reduce water flow resistance, thereby improving the energy conversion efficiency of the entire water wheel assembly, so that the device can achieve higher power generation efficiency even in a low-head environment.

[0016] The side of the water wheel assembly fits the curved inner wall of the pressure chamber, ensuring the stability of the water wheel assembly during operation and enabling it to better withstand the impact of water flow. The blades are connected to the fixing rod by welding and polished to ensure the firmness of the connection, prevent the blades from falling off during high-speed operation, and reduce water turbulence and resistance. The inner wall of the pressure chamber is coated with an epoxy resin anti-corrosion coating, which effectively resists water corrosion, extends the service life of the pressure chamber, and reduces the maintenance and replacement costs caused by corrosion. These measures have jointly improved the stability and reliability of the long-term operation of the device.

[0017] The water wheel disc is made of high-strength aluminum alloy material, which is light in weight and high in strength. It reduces the moment of inertia, facilitates starting and acceleration, and can withstand large torque to ensure long-term operation without deformation and damage. The speed increaser adopts a planetary gear speed increaser with high transmission efficiency and compact structure, which can effectively increase the speed of the water wheel disc. The generator is a permanent magnet synchronous generator with high power generation efficiency and stable operation. It does not require an external excitation power supply and has good output voltage and frequency stability. The blade surface is a smooth curved surface with low roughness, which reduces water flow friction resistance and cavitation, improves the rotation efficiency of the water wheel assembly, and extends the service life of the blades, optimizing the overall performance of the device from multiple aspects.

[0018] The implementation method includes testing the water quality of low-head water sources, and a multi-stage filtration system can be set up before the water inlet tank according to the water quality. The filtration system can effectively remove suspended matter, colloids, bacteria, viruses and other impurities in the water, prevent impurities from entering the device and causing damage such as wear, corrosion or blockage to various components, ensure the normal operation of the hydropower generation device under different water quality environments, extend the service life of the device, and also help maintain power generation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the installation of the water wheel assembly of the present invention; Figure 2 is a schematic diagram of the drainage housing of the present invention; Figure 3 is a three-dimensional schematic diagram of the drainage housing of the present invention; Figure 4 The present invention Figure 2 Schematic diagram of the AA section; Figure 5 The present invention Figure 2 Schematic diagram of the middle BB; Figure 6 is a schematic diagram of a water wheel assembly of the present invention; Figure 7 It is a schematic diagram of a blade assembly of the present invention.

[0020] In the figure: 1. drainage shell; 2. water inlet trough; 3. pressure chamber; 4. water outlet trough; 5. water wheel assembly; 51. water wheel turntable; 52. blade group; 521. blade; 522. fixing rod; 523. water hole; 6. cover. DETAILED DESCRIPTION

[0021] See also Figure 1-7The present invention provides a technical solution: a hydroelectric power generation device suitable for low head environment and its implementation method, wherein the drainage shell 1 is made of high-strength and corrosion-resistant 304 stainless steel material. The plate cutting adopts laser cutting technology, the cutting edge is flat and smooth, and the dimensional accuracy is controlled within ±0.5mm. During bending, the bending angle error does not exceed ±0.5°. The dimensional accuracy of the openings of the water inlet 2 and the water outlet 4 is controlled within ±1mm.

[0022] In the adjustable drainage opening structure of the water inlet trough 2, the sliding baffle track is made of aluminum alloy and fixed to the drainage housing 1 by M8 bolts. The bolt tightening torque is controlled at 12N·m. The sliding baffle is made of 3mm thick 304 stainless steel plate, and the surface is galvanized for rust prevention. The slider between the baffle and the track is made of polytetrafluoroethylene material with a size of 20mm×30mm×10mm. The rubber sealing strip is embedded with a 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. The position of the baffle can be accurately adjusted by turning the screw, and the adjustment accuracy can reach ±1mm. The motor power of the electric control device is 0.5kW, the reduction ratio of the reducer is 50:1, the transmission chain is 10A model, and the position sensor accuracy is 0.1mm.

[0023] The pressure chamber 3 is welded in the middle of the drainage shell 1. The welding adopts argon arc welding process, the welding current is 150A, the voltage is 18V, and the welding speed is 8mm / s. The weld is inspected for flaw detection, and there are no defects such as pores and cracks. When the inner wall of the pressure chamber 3 is pretreated, the sandblasting pressure of the sandblasting and rust removal equipment is 0.4MPa, and the abrasive is 40 mesh quartz sand. The surface roughness after sandblasting reaches 3.2μm. Wipe the inner wall surface with acetone solvent, wipe twice, and each time interval is 10 minutes. The epoxy resin coating is applied by a high-pressure airless sprayer, the spraying pressure is 0.6MPa, the nozzle is 20cm away from the inner wall surface, the spray gun moves at a speed of 30cm / s, and the coating is applied twice. The thickness of each layer is controlled between 0.2-0.3mm, and the total thickness reaches 0.3-0.5mm. After coating, it is cured at room temperature for 48 hours, and the environment is kept well ventilated during the curing process.

[0024] The installation foundation of the drainage shell 1 is cast with C30 concrete, with the foundation size of 2000mm×1500mm×1000mm and the foundation depth of 1.2m. The embedded anchor bolts are M20 in size, with an embedded depth of 0.8m and a height of 50mm above the foundation surface. The drainage shell 1 is connected to the foundation through the anchor bolts, with the nut tightening torque of 200N·m. After installation, use a level to check the levelness of the drainage shell 1, and the levelness error shall not exceed ±0.2°.

[0025] The water wheel turntable 51 is made of 6061-T6 aluminum alloy. When the raw materials are smelted, the medium frequency induction furnace smelting temperature is controlled at 750°C, and an appropriate amount of refining agent and modifier are added, and the refining time is 30 minutes. The surface roughness of the gravity casting mold cavity is 1.6μm, and the water wheel turntable 51 blank is obtained after casting. During machining, the outer circle turning parameters on the lathe are: cutting speed 150m / min, feed rate 0.2mm / r, cutting depth 1mm, and the outer circle diameter accuracy after machining reaches ±0.05mm, and the flatness error does not exceed ±0.02mm. The parameters for milling the keyway on the milling machine are: cutting speed 120m / min, feed rate 0.1mm / z, cutting depth 2mm, and the keyway width accuracy reaches ±0.03mm. The drilling diameter accuracy on the drilling machine reaches ±0.1mm, and the position accuracy is controlled within ±0.1mm. During heat treatment, the solution treatment temperature is 530°C, the holding time is 3 hours, and the aging treatment temperature is 180°C, and the holding time is 5 hours.

[0026] The blade 521 of the blade group 52 is manufactured by precision casting process, and the manufacturing accuracy of the lost wax casting mold is ±0.1mm. The melting temperature of the casting material ZL104 aluminum alloy is 720℃, the pouring temperature is 680℃, and the pouring speed is 1kg / s. When the surface of the blade 521 is ground and polished, it is first coarsely ground with 80 mesh sandpaper, then finely ground with 180 mesh, 320 mesh, and 600 mesh sandpaper in sequence, and finally mirror polished with polishing paste. The fixed rod 522 is made of 304 stainless steel round steel with a diameter of 12mm. The blade 521 and the fixed rod 522 are welded by argon arc welding, with a welding current of 120A, a voltage of 15V, and a welding speed of 6mm / s. After welding is completed, the weld is polished to make its surface flush and smooth with the surface of the blade 521 and the fixed rod 522. The water holes 523 at the bottom of the two upper blades 521 are drilled with a drill bit of 8 mm in diameter, and the drilling position accuracy is controlled within ±0.5 mm. The drilling is performed using a drilling machine, and the inner wall of the water hole 523 is deburred after the processing.

[0027] The rotating shaft of the water wheel turntable 51 is installed on the two side walls of the pressure chamber 3 through the bearing seat, and the bearing is a 6205 deep groove ball bearing. The bearing is installed by thermal installation, the heating temperature is 100°C, and the heating time is 10 minutes. After installation, check the rotation flexibility of the water wheel assembly 5. Manually rotate the water wheel turntable 51, which should rotate smoothly without sticking. At the same time, check the gap between the blade 521 and the inner wall of the pressure chamber 3. The gap is uniform and the minimum gap is not less than 3mm.

[0028] The speed increaser uses a planetary gear speed increaser. According to the speed range of the water wheel turntable 51 (20-80 rpm) and the input speed of the generator (1500 rpm), the transmission ratio of the planetary gear speed increaser is designed to be 75. The sun gear, planetary gear and inner ring gear are all made of 20CrMnTi high-quality alloy steel.

[0029] The assembly of the planetary gear speed increaser is carried out in a clean assembly workshop. Before assembly, all parts are cleaned and inspected to remove oil and impurities, and the meshing of the gears and the clearance of the bearings and other parameters are checked. During assembly, the sun gear and the input shaft have an interference fit of 0.08mm. The sun gear is heated to 150℃ before assembly. The rolling bearing model between the planetary gear and the planetary carrier is 6204. Apply an appropriate amount of high-temperature lithium-based grease during installation. The inner gear ring is connected to the housing with M12 bolts, and the tightening torque of the bolts is 100N·m. After connection, check the meshing clearance between the inner gear ring and the planetary gear. The clearance should be uniform and between 0.1-0.3mm. After assembly, the speed increaser is tested for no-load operation for 2 hours, and the vibration acceleration does not exceed 5m / s².

[0030] The generator uses a permanent magnet synchronous generator, and the permanent magnet uses a neodymium iron boron permanent magnet with a residual magnetic density of 1.2T and a coercive force of 900kA / m. The stator core is made of 0.5mm thick 50W470 silicon steel sheets laminated, with a lamination coefficient of 0.95. The winding is wound with 1.5mm diameter enameled wire, the number of turns is determined according to the generator design requirements, and the connection method is star connection.

[0031] The generator is installed at the output end of the speed increaser and connected to the speed increaser through an elastic coupling. The torsional stiffness of the coupling is 1000N·m / rad, and the axial play does not exceed 0.5mm. During installation, use a dial indicator to check the coaxiality of the generator and the speed increaser. The coaxiality error does not exceed 0.1mm. The generator casing is grounded, and the no-load test and load test of the generator are carried out. During the no-load test, check the output voltage and frequency of the generator. The voltage fluctuation does not exceed ±5%, and the frequency fluctuation does not exceed ±0.5Hz. During the load test, gradually increase the load and check the performance indicators of the generator such as output power, efficiency and temperature rise to ensure that the generator can operate stably under rated load, the efficiency is not less than 85%, and the temperature rise does not exceed 80℃.

[0032] The design of the surface roughness of blade 521 being no greater than 0.8 microns is achieved through the above-mentioned precision casting and grinding and polishing process after CNC machining. In actual operation, the smooth blade surface can reduce the frictional resistance of water flow on the blade surface by about 30%. When the water flow velocity is 2m / s, after testing, the water flow separation point on the smooth blade surface is significantly moved backward, reducing the turbulent water flow area, thereby improving the rotation efficiency of the water wheel assembly 5 by about 15%. At the same time, the smooth surface increases the critical pressure of cavitation on the surface of blade 521 by about 20%, effectively reducing the probability of cavitation and extending the service life of blade 521 by about 2-3 years.

[0033] The arc structure of blade 521 is designed with a gradual curvature from the root to the tip of the blade, which is optimized and determined through hydrodynamic simulation and actual test. The radius of the root arc is 150mm, and the radius of the tip arc is 250mm. This arc design enables blade 521 to better adapt to changes in water flow speed and direction at different water layer positions. In low head water flow, blade 521 can capture water flow energy more effectively and improve energy conversion efficiency by about 10%-15%.

[0034] The water quality test uses a multi-parameter water quality tester to test the pH, dissolved oxygen, conductivity, turbidity, suspended solids and other indicators in the water source. The test frequency is a comprehensive test before the initial installation and operation of the device, and then a weekly sampling test. If the test results show that the suspended solids content in the water exceeds 50mg / L, the pH value is not within the range of 6.5-8.5, and other water quality does not meet the requirements, a filter device needs to be installed before the water inlet tank 2.

[0035] The mesh filter in the coarse filtration stage has a mesh aperture of 0.8mm determined according to the size of the larger particle impurities in the water source. The filter shell is made of 304 stainless steel and has a size of 500mm×300mm×200mm. The fine filtration uses a polypropylene melt-blown filter element with a filter element aperture of 10 microns, a filter element size of 100mm in diameter and 500mm in length. The ultrafiltration uses an ultrafiltration membrane assembly with a molecular weight cutoff of 50,000 Daltons and a membrane assembly area of ​​10m². When the filtration device is installed, the filters are connected by pipes. The pipes are made of UPVC material with a pipe diameter of 50mm. The connection method is flange connection, and the connection is well sealed. Clean the filtration device regularly or replace the filter element. The coarse filter is cleaned once a week, the fine filter element is replaced every 2 months, and the ultrafiltration membrane is chemically cleaned every 6 months.

Claims

1. A hydroelectric power generation device suitable for low head environment, characterized in that: include Drainage housing (1): the drainage housing (1) serves as a water flow guiding structure of the entire device, and its main function is to effectively guide low-head water flow into the power generation area; the drainage housing (1) has a water inlet trough (2) and a water outlet trough (4), the water inlet trough (2) is particularly arranged at the low-head water source, and has an adjustable drainage opening. Through this adjustable design, the water flow entering the device can be accurately controlled according to the actual water flow conditions and power generation requirements; at the same time, a pressure chamber (3) is opened in the middle of the drainage housing (1), and the pressure chamber (3) provides a specific space environment for the installation and operation of the subsequent water wheel assembly (5); A water wheel assembly (5): the water wheel assembly (5) is installed inside the pressure chamber (3) in the middle of the drainage housing (1), and comprises a water wheel rotating disc (51) in the middle and a blade group (52) evenly arranged on the water wheel rotating disc (51); the side surface of the water wheel assembly (5) is tightly fitted to the arc-shaped inner wall of one side of the pressure chamber (3), and such a design ensures the stability of the water wheel assembly (5) during operation and the effectiveness of water flow impact; the blade group (52) is composed of three groups of arc-shaped blades (521), and a fixing rod (522) is provided at the rear end of the blade (521), and the blade (521) is fixed to the water wheel rotating disc (51) by the fixing rod (522); and water holes (523) that are interconnected are provided at the bottom of the two upper groups of blades (521), and such a design of the water holes (523) is conducive to the circulation of water between the blade groups (52), thereby reducing The water flow resistance is reduced, thereby improving the working efficiency of the water wheel assembly (5); the arc structure of the blade (521) has a gradually changing curvature from the blade root to the blade tip. This special curvature design can better adapt to the impact of the water flow and improve the ability of the blade (521) to capture water flow energy; the water wheel turntable (51) extends out of the drainage housing (1) and is connected to the speed increaser. After the speed is further increased by the speed increaser, it is connected to the generator, and finally the generator converts the mechanical energy into electrical energy; the three groups of blades (521) are vertically tilted and fixed on the side wall of the fixing rod (522), and the middle fixed blade (521) is tilted by 20-30 degrees, while the lower blade (521) is tilted by 40-45 degrees. This tilt design at different angles enables the blade group (52) to efficiently utilize water flow energy at different water layer positions, thereby improving the energy conversion efficiency of the entire water wheel assembly (5).

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

3. A hydroelectric power generation device suitable for low head environment according to claim 1, characterized in that: The anti-corrosion coating applied to the inner wall of the pressure chamber (3) is an epoxy resin coating. Before applying the epoxy resin coating, the inner wall of the pressure chamber (3) needs to be pretreated. First, the inner wall surface is derusted, which can be done by sandblasting or mechanical grinding to ensure that there is no rust, oil stains or other impurities on the inner wall surface. Then, the surface is cleaned by wiping the inner wall surface with a cleaning solvent such as acetone or ethanol, and the coating is applied after the surface is dry. The epoxy resin coating is applied by spraying or brushing, and the coating thickness is controlled to be between 0.3 and 0.5 mm. After the coating is completed, a curing treatment is performed. The curing conditions are carried out according to the product instructions of the epoxy resin coating. Generally, the curing time is 24 to 48 hours at room temperature, or the curing time is shortened under the condition of appropriately increasing the temperature. The epoxy resin coating has excellent corrosion resistance and can effectively resist corrosion of the inner wall of the pressure chamber (3) by acid and alkali substances in the water flow and dissolved oxygen in the water, thereby extending the service life of the pressure chamber (3), ensuring long-term stable operation of the device, and reducing maintenance and replacement costs caused by corrosion.

4. A hydroelectric power generation device suitable for low head environment according to claim 1, characterized in that: The fixing rod (522) and the blade (521) are connected by welding. During welding, welding materials suitable for the materials of the blade (521) and the fixing rod (522) are selected. For example, for aluminum alloy blades (521) and aluminum alloy fixing rods (522), aluminum alloy welding wires can be selected. The welding process adopts argon arc welding, so that the surface of the welding point is flush with the surface of the blade (521) and the fixing rod (522) and the transition is smooth. This processing method not only ensures the firmness of the connection between the fixing rod (522) and the blade (521), and prevents the blade (521) from falling off during the high-speed operation of the water wheel assembly (5), but also makes the surface smooth by grinding, thereby reducing the turbulence and resistance of the water flow at the connection point, which is conducive to improving the overall performance of the water wheel assembly (5).

5. A hydroelectric power generation device suitable for low head environment according to claim 1, characterized in that: The speed increaser is a planetary gear speed increaser; the planetary gear speed increaser mainly consists of a sun gear, planetary gears, an inner gear ring and a planet carrier component; the sun gear is located at the center and is connected to a rotating shaft extending from a water wheel turntable (51); the planetary gears are evenly distributed around the sun gear and mesh with the sun gear and the inner gear ring; the planet carrier is used to support the planetary gears and output power; the transmission principle of the planetary gear speed increaser is based on the motion characteristics of a planetary gear system; a higher transmission ratio can be achieved by reasonably designing the gear ratio of each gear.

6. A hydroelectric power generation device suitable for low head environment according to claim 1, characterized in that: 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 a winding, the iron core is made of high-quality silicon steel sheets laminated to reduce hysteresis loss; the winding is wound with copper wire, and the number of turns, wire diameter and connection method parameters of the winding 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 water wheel assembly (5) drives the generator rotor to rotate, the magnetic field generated by the rotor permanent magnet moves relative to the stator winding, thereby generating an induced electromotive force in the stator winding; because the magnetic field of the permanent magnet synchronous generator is provided by the permanent magnet, no external excitation power supply is required.

7. A method for implementing the hydroelectric power generation device suitable for low head environment according to claim 1, characterized in that: The following steps are involved: S1: Installation of drainage housing and adjustment of water inlet trough The drainage housing (1) is accurately placed at the low-head water source to ensure that its position is stable and can receive water flow to the greatest extent; after the drainage housing (1) is placed, the drainage opening of the water inlet trough (2) is adjusted; during the adjustment, the opening size of the water inlet trough (2) is changed through corresponding adjustment devices (such as adjustable baffles, valves, etc.) according to factors such as the actual water flow rate of the low-head water source, the water flow speed, and the power required by the current power generation device, so as to achieve accurate control of the water flow entering the pressure chamber (3) inside the drainage housing (1); during the adjustment process, the water flow condition can be monitored in real time with the help of water flow measuring instruments and other equipment to achieve the best drainage effect, so that the low-head water flow can stably and effectively enter the pressure chamber (3); S2: Water wheel assembly drive and speed increaser operation When the drainage opening of the water inlet trough (2) is adjusted, the water flows into the pressure chamber (3), and then impacts the blade group (52) of the water wheel assembly (5) at a certain speed and pressure; due to the arc-shaped structure and specific inclination angle of the blades (521), the water flow exerts a force on the blades (521), so that the blades (521) drive the water wheel turntable (51) to rotate; During the rotation of the water wheel turntable (51), the rotating shaft extending out of the drainage housing (1) transmits power to the speed increaser; after receiving the power from the water wheel turntable (51), the speed increaser uses its internal gear transmission mechanism or other speed increase principles to increase the rotation speed of the water wheel turntable (51) to a rotation speed range suitable for the operation of the generator, thereby ensuring the efficient operation of the subsequent power generation process; S3: Mechanical energy is converted into electrical energy output The power after the speed increaser is transmitted to the generator. The rotor inside the generator starts to rotate under the drive of the power. The magnetic field inside the generator moves relative to the winding, thereby generating an induced electromotive force in the winding. According to the principle of electromagnetic induction, this induced electromotive force will cause the current to flow in the winding, realizing the conversion of mechanical energy into electrical energy. The converted electric energy is output through the output end of the generator and can be connected to external power equipment or power grid to provide power supply to users; During the whole process, the output electric energy of the generator can be monitored by corresponding monitoring equipment to ensure the normal operation and power quality of the power generation device.

8. A hydroelectric power generation device suitable for low water head environment according to claim 7, characterized in that: The surface of the blade (521) is a smooth curved surface, and its processing technology adopts precision casting or CNC machining. In the precision casting process, a high-precision mold is used to ensure the accuracy of the curved surface shape of the blade (521), and the surface is ground and polished after casting to make the surface roughness reach the requirement of not more than 0.8 microns. If CNC machining is adopted, advanced CNC machining equipment is used to perform precise cutting according to the pre-designed curved surface model of the blade (521), and after the machining is completed, a detailed grinding and polishing process is also performed. The blade (52 1) The design of a surface roughness of no more than 0.8 micrometers can significantly reduce the frictional resistance of water flow on the surface of the blade (521); when the water flow impacts the blade (521), the smooth surface enables the water flow to flow through the blade (521) more smoothly, thereby reducing energy loss and improving the rotation efficiency of the water wheel assembly (5); at the same time, the smooth surface can also reduce the probability of cavitation on the surface of the blade (521), further protecting the blade (521) from damage, extending the service life of the blade (521), thereby improving the reliability and economy of the entire hydroelectric power generation device.

9. A hydroelectric power generation device suitable for low water head environment according to claim 8, characterized in that: The water wheel turntable (51) is made of a high-strength aluminum alloy material; the high-strength aluminum alloy material is improved in strength and hardness by a reasonable ratio of alloy elements, such as adding copper, magnesium, and silicon elements, and undergoing a specific heat treatment process; in the material preparation process, the raw materials are first smelted to ensure that the elements are evenly distributed, and then cast or forged to obtain a blank of the water wheel turntable (51); the blank is machined, such as through turning, milling, and drilling processes, to achieve the dimensional accuracy and shape accuracy required by the design; the water wheel turntable (51) The advantage of using a high-strength aluminum alloy material is that it is lightweight and can effectively reduce the rotational inertia of the water wheel assembly (5) compared to a conventional cast iron or steel water wheel turntable (51), making it easier to start and accelerate the water wheel assembly (5); at the same time, the high-strength aluminum alloy has a relatively high strength and can withstand the impact of water flow and the torque transmitted by the blades (521), thereby ensuring that the water wheel turntable (51) will not be deformed or damaged during long-term operation, thereby improving the reliability and stability of the water wheel assembly (5) and extending the service life of the entire hydroelectric power generation device.

10. The method for implementing a hydroelectric power generation device suitable for a low head environment according to claim 9, characterized in that: In step S1, the method for testing the water quality of the low-head water source is as follows: a multi-parameter water quality detector is used to test the pH, dissolved oxygen, conductivity, turbidity, and suspended matter indicators in the water source; the detection frequency can be determined according to the stability of the water source and the actual situation. Generally, a comprehensive test is carried out before the initial installation and operation of the device, and then regular sampling is carried out, such as once a week or a month; if the test results show that the water quality does not meet the requirements, such as the suspended matter content in the water is too high or the pH value exceeds the normal range, it is necessary to set a filtering device before the water inlet tank (2); the filtering device can select a multi-stage filtering system, including coarse filtration, fine filtration and ultrafiltration; the coarse filtration uses a filter screen filter, the pore size of which is determined according to the size of larger particle impurities in the water source, generally between 0.5-1 mm, and is used to remove larger suspended matter in the water. Floating objects, floating objects and sediment; fine filtration can choose a filter element filter, the filter element material is a polypropylene melt-blown filter element or a folded filter element, the filter element pore size is between 5-20 microns, and the smaller particle impurities in the water are further removed; ultrafiltration uses an ultrafiltration membrane assembly, the molecular weight cutoff of the ultrafiltration membrane is generally between 1000-100000 Daltons, and it can effectively remove colloids, bacteria, viruses and tiny impurities in the water; by setting up such a filtering device, it can ensure that the water flow entering the drainage housing (1) is clean, prevent impurities from entering the device and causing wear, corrosion or blockage damage to the water wheel assembly (5), the speed increaser, and the generator parts, thereby ensuring the normal operation of the hydroelectric power generation device, extending the service life of the device, and improving the power generation efficiency; at the same time, the filtering device is cleaned or the filter element is replaced regularly to maintain its filtering effect.

Images