Ultrahigh-water-head small-flow pump turbine runner blade

Abstract

The utility model discloses an ultrahigh-water-head small-flow pump turbine runner blade. The blade comprises a blade wrap angle, a blade inlet setting angle, a blade outlet setting angle, a high-low pressure side diameter ratio and a guide blade relative height. The runner blade is scientific and reasonable in structural design, meets the design requirement of a runner, has better hydraulic performance, can greatly reduce the water storage capacity scale, is short in construction period, can accelerate the development of pumped storage, and is suitable for large-scale popularization and application, and the ultra-high-water-head small-flow pump turbine is constructed by utilizing the runner blade of the ultra-high-water-head small-flow pump turbine. The problem of in-situ consumption of renewable energy sources is effectively solved, and good social and economic benefits are achieved.

Description

A type of ultra-high head, low flow rate water pump turbine runner blade Technical Field

[0001] This utility model relates to water turbines, and in particular to a turbine runner blade for an ultra-high head, low flow rate water pump. Background Technology

[0002] Under the dual-carbon goals, distributed renewable energy is developing rapidly, but its intermittency and instability still constrain its development. Pumped storage, as a mature energy storage technology, has advantages such as large storage capacity, high-efficiency conversion, long-term storage, and environmental sustainability, and is being vigorously developed alongside the development of new energy. According to the "Pumped Storage Industry Development Report 2023," China has planned a total of approximately 823 million kilowatts of pumped storage power station resources. In 2023, 5.15 million kilowatts of new installed capacity were put into operation, bringing the total installed capacity in operation to 50.94 million kilowatts, of which 12 million kilowatts were added during the construction phase. While the scale of pumped storage development continues to expand, it still cannot fully meet the needs of the rapid development of new energy. The development of pumped storage is relatively lagging due to issues such as site selection and construction cycles. Converting pump stations or hydropower stations into pumped storage facilities is an important means to accelerate the development of pumped storage. Furthermore, to solve the problem of local consumption of distributed renewable energy, on-site construction of ultra-high head, low-flow pump turbines is imperative.

[0003] Ultra-high head, low-flow pump-turbine turbines, as a type of small-scale pumped storage power station, possess unique fluid parameter characteristics that reduce geographical constraints on project site selection. Compared to conventional pumped storage power stations, they can significantly reduce reservoir capacity, shorten construction cycles, accelerate the development of pumped storage, and effectively address the issue of local renewable energy consumption. Currently, research on pump-turbines focuses on ultra-high head and large-capacity applications, with limited research on ultra-high head, low-flow pump-turbine turbines. The runner, as the core energy conversion component, and the runner blades, as the core component of the runner, require breakthroughs in the dynamic characteristics of conventional pump-turbine runners to meet demand. Therefore, researching ultra-high head, low-flow pump-turbine runner blades is crucial for improving its optimized design theory and promoting practical engineering applications; however, no relevant public reports have been found to date. Summary of the Invention

[0004] In view of the above situation and to overcome the defects of the existing technology, the purpose of this utility model is to provide a turbine runner blade for an ultra-high head, low flow water pump, which can effectively solve the problem that there is no turbine runner blade for ultra-high head, low flow water pump.

[0005] To achieve the above objectives, the technical solution provided by this utility model is a turbine runner blade for an ultra-high head, low flow water pump, wherein the blade wrap angle Ψ = 90°~130°, the blade inlet installation angle β1 = 22.4°~34.8°, the blade outlet installation angle β2 = 19°~20°, the high-low pressure side diameter ratio D2 / D1>2, and the guide vane relative height b0 / D2<0.07.

[0006] This utility model has a scientific and reasonable structural design that meets the requirements of turbine runner design and has good hydraulic performance. The ultra-high head low flow pump turbine built using the runner blades of the ultra-high head low flow pump turbine can significantly reduce the scale of water storage reservoirs, has a short construction period, can accelerate the development of pumped storage, effectively solve the problem of local consumption of renewable energy, and has good social and economic benefits. Attached Figure Description

[0007] Figure 1 is a design drawing of the blade of this utility model.

[0008] Figure 2 is a schematic diagram of the structure of this utility model;

[0009] In the diagram, v 1p The absolute velocity at the water pump inlet under operating conditions is in m / s; u 1p ω is the inlet circumferential velocity under pump operating conditions, in m / s; 1p V is the relative velocity at the pump inlet under pump operating conditions, in m / s; 2p u represents the absolute velocity at the pump outlet under operating conditions, in m / s. 2p ω is the outlet circumferential velocity under pump operating conditions, in m / s; 2p V is the relative velocity at the pump outlet under operating conditions, in m / s; 1T The absolute velocity at the turbine inlet under operating conditions is expressed in m / s; u 1T ω is the inlet circumferential velocity of the turbine under operating conditions, in m / s; 1T V is the relative velocity at the turbine inlet under operating conditions, in m / s; 2T u is the absolute velocity at the turbine outlet under operating conditions, in m / s. 2T ω is the outlet circumferential velocity of the turbine under operating conditions, in m / s; 2α The relative velocity at the turbine outlet under operating conditions is given in m / s.

[0010] Figure 3 is an external characteristic diagram of the ultra-high head, low flow rate water pump turbine after optimization according to an embodiment of this utility model.

[0011] Figure 4 is a water body model of the turbine runner of the ultra-high head, low flow water pump according to an embodiment of this utility model.

[0012] Figure 5 is a frequency domain characteristic diagram of pressure pulsation of the ultra-high head, low flow rate water pump turbine after optimization according to an embodiment of this utility model. Detailed Implementation

[0013] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings and specific circumstances.

[0014] As shown in the accompanying drawings, a turbine runner blade for an ultra-high head, low flow rate water pump is characterized in that the blade 1 has a blade wrap angle Ψ = 90°~130°, a blade inlet installation angle β1 = 22.4°~34.8°, a blade outlet installation angle β2 = 19°~20°, a high-low pressure side diameter ratio D2 / D1>2, and a guide vane relative height b0 / D2<0.07.

[0015] To ensure better implementation results, the blade 1 is an integral structure made of high-strength corrosion-resistant alloy by casting or CNC machining. The inlet and outlet edges of the blade 1 are respectively coated with wear-resistant layers to improve the service life and impact resistance of the blade.

[0016] The blade 1 has a blade wrap angle Ψ = 100°, a blade inlet placement angle β1 = 28.6°, and a blade outlet placement angle β2 = 19.5°.

[0017] In practical use, this invention is installed together with the upper crown and lower ring of an existing wheel, and then mounted on the center of the wheel chamber via a main shaft.

[0018] In specific implementation, this utility model can be given by the following embodiments.

[0019] The Qilian Mountains, located at the border of Gansu and Qinghai, have a generally high elevation, with many peaks exceeding 4,000 meters and significant valley elevation differences. The Hexi Corridor along its eastern side boasts leading wind and solar power resources nationwide, and possesses great potential for distributed energy development. An ultra-high head, low-flow pumped storage project can be planned in this area to serve as a channel for the local consumption and transmission of new energy in Northwest China, enhancing wind and solar power absorption capacity. The proposed site for an ultra-high head, low-flow pumped storage power station is as follows: [The following values ​​are tentatively taken as the design flow rate Q]. P It is 1.475m 3 / s, pump head H P The rated speed of the unit is 700m. r The speed is 2900 r / min, and the power is approximately 9.12 MW. The design features a blade wrap angle Ψ = 100°, a blade inlet angle β1 = 28.6°, a blade outlet angle β2 = 19.5°, a high-pressure side diameter D2 of 798 mm, a low-pressure side diameter D1 of 300 mm, a guide vane height b0 of 55.3 mm, and 7 blades. The entire flow channel of the computational model was meshed, and numerical calculations were performed using CFX to obtain the hydraulic performance of the ultra-high head, low-flow pump turbine using the blades designed in this invention.

[0020] Figure 3 shows the performance variation of the ultra-high head, low-flow pump turbine. Under turbine operation, the efficiency curve increases with increasing flow rate, with the fastest growth rate between 0.7Q and 0.8Q, followed by a decrease and stabilization. The power curve increases with increasing flow rate, and the power growth rate gradually increases, reaching 81.31% efficiency and 10.45MW output at 1.3Q. Under pump operation, the efficiency curve initially increases, then decreases, and then increases again with increasing flow rate, with the efficiency growth rate initially gradually increasing, then gradually decreasing, and then gradually increasing again. The hump characteristic curve is generally good, with a reduced hump region. After optimization starting from 0.9Q, the head initially decreases, then increases, and then decreases again with increasing flow rate, with the head curve growth rate initially gradually decreasing, then gradually increasing, and then gradually decreasing again, reaching 80.64% efficiency and 721m head at 1.0Q. In summary, the ultra-high head, low flow rate pump turbine with blades designed according to this utility model achieves improved efficiency, power, and head under optimal operating conditions, expands the high-efficiency zone compared to before optimization, and enhances operational stability.

[0021] Figure 5 shows the pressure pulsation characteristics of a high-head, low-flow pump turbine under design conditions. Under pump design conditions, the pressure pulsation amplitude in the bladeless region is large and its periodicity is significant. The pressure pulsation amplitude reaches its maximum (0.0476 kPa) at monitoring point P6 in Figure 4, with its main frequencies being 0.5 times the rotational speed, the blade frequency, and their harmonics. The main frequency characteristics of the pressure pulsation at monitoring point P5 are the same as at P6. The pressure pulsation amplitude in the runner is relatively small. The pressure pulsation amplitude at monitoring point P7 is 0.0304 kPa, with its main frequencies being the rotational speed, the blade frequency, and their harmonics (f / fn = 7, 14). The pressure pulsation amplitude at monitoring point P8 is smaller than that at monitoring point P7, but the main frequency characteristics are the same as at P7. Under the turbine's design conditions, the pressure pulsation spectrum in the bladeless region exhibits broadband characteristics. The pressure pulsation amplitude reaches its maximum (0.0678 kPa) at monitoring point P5, with the main frequencies being the blade frequency and its harmonics. The main frequency distribution of the pressure pulsation at monitoring point P6 is the same as that at P5. The pressure pulsation amplitude at the runner is smaller, with a value of 0.0081 kPa at monitoring point P7. The main frequencies are the rotor frequency and blade frequency. The pressure pulsation amplitude at monitoring point P8 is smaller than that at P7, with the main frequencies being the blade frequency and rotor frequency. In summary, the runner blades and guide vanes are well matched, the pressure pulsation amplitude is moderate, and the flow is relatively stable. This also indicates minimal flow separation within the flow channel, low cavitation risk, and controllable cavitation phenomena.

[0022] In summary, the ultra-high head, low flow rate pump turbine runner blades designed in this utility model are scientifically and rationally designed, meeting the runner design requirements while possessing good hydraulic performance to satisfy user operational requirements. This reduces the difficulties associated with conventional pumped storage power stations, such as challenging site selection, long construction periods, and high costs. It effectively solves the problem of localized consumption of distributed renewable energy, accelerates the construction of a new power system based on new energy sources, and contributes to energy transformation and upgrading. It is applicable to the pumped storage retrofitting of conventional axial-flow turbines, mixed-flow turbines, and axial-flow pumps, providing technical support for the research and development of fluid machinery in small pumped storage power stations. This represents a major innovation in high-head, low-flow rate pump turbine runner blades and has significant social and economic benefits.

[0023] It should be noted that the above embodiments are only used to illustrate the technical methods of this utility model, and are not intended to limit the scope of protection of this utility model. Although suitable examples have been used to illustrate the design method in detail, in the field of ultra-high head small flow water pump turbine design, any equivalent embodiments or changes to the design scheme of this utility model that do not depart from the design method of this utility model are within the scope of protection of this utility model.

Claims

1. A turbine runner blade for an ultra-high head, low-flow-rate water pump, characterized in that, The blade (1) has a blade wrap angle Ψ = 90°~130°, a blade inlet placement angle β1 = 22.4°~34.8°, a blade outlet placement angle β2 = 19°~20°, a high-low pressure side diameter ratio D2 / D1>2, and a guide vane relative height b0 / D2<0.

07.

2. The turbine runner blade for an ultra-high head, low-flow-rate water pump according to claim 1, characterized in that, The blade (1) is an integral structure formed by casting or CNC machining of high-strength corrosion-resistant alloy, and the inlet and outlet edges of the blade (1) are respectively coated with wear-resistant layers.

3. The turbine runner blade for an ultra-high head, low-flow water pump according to claim 1, characterized in that, The blade (1) has a blade wrap angle Ψ = 100°, a blade inlet placement angle β1 = 28.6°, and a blade outlet placement angle β2 = 19.5°.

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