The world of hydroelectric power generation relies heavily on precision engineering and advanced manufacturing techniques.
Among these, the seamless rolled ring manufacturing process plays a pivotal role in producing key components of turbines.
This innovative method ensures high-quality rings are created, which are essential for the overall efficiency and performance of hydroelectric systems.
In this section, we will explore the seamless rolled ring manufacturing process, detailing each step involved and the importance of quality control throughout.
Following that, we will delve into the production of stay rings specifically designed for Francis turbines, followed by a closer look at Francis runner production and the comprehensive fabrication and assembly processes involved.
Seamless Rolled Ring Manufacturing Process
The seamless rolled ring manufacturing process is a sophisticated technique that allows for the creation of rings with varying dimensions and material properties.
This process begins with rigorous quality control of incoming materials to ensure only the best inputs are used.
Once materials are selected, they undergo computer-aided design (CAD) to determine the ideal specifications for the desired ring shape.
The forging process follows, where the metal is heated and pressed into a preliminary shape.
Maintaining precise temperature control during forging is critical to achieving the correct forging ratios and ensuring the ring blank’s shape and consistency.
After forging, the ring blank is subjected to ring rolling on a CNC machine.
This step shapes the blank into a ring form, which is then heat-treated to enhance its mechanical properties.
Quality control measures are essential at this stage, including inspections of raw materials and monitoring the machining and heat treatment processes.
Ultimately, the seamless rolled rings produced through this process are integral to the functioning of various turbine components, ensuring they can withstand the demanding conditions of hydroelectric power generation.
Stay Ring Production for Francis Turbines
The stay ring is a crucial component of the Francis turbine, providing essential support to the turbine blades while maintaining the alignment of the runner assembly.
The production of the stay ring involves several carefully monitored processes.
Initially, high-strength steel is selected for its ability to endure high centrifugal forces and hydraulic pressures during turbine operation.
Following material selection, the stay ring is machined using various techniques, including CNC machining, milling, and drilling to achieve the desired shape and dimensions.
After machining, the stay ring is treated with protective coatings to enhance longevity and resist corrosion.
Common treatments include electroplating, anodizing, and powder coating.
The stay ring is then installed at the upstream end of the turbine runner, bolted securely to the turbine casing, ensuring stability and optimal performance.
Francis Runner Production
The production of a Francis runner is a meticulous process requiring high precision and expertise.
The journey begins with the creation of a 3D model using specialized software. This model serves as a template for making a mold for the runner.
Once the mold is prepared, molten metal is poured into it. Typically, a high-strength alloy is used, selected based on the specific requirements for durability.
After the metal solidifies, the runner is removed and goes through a finishing process that includes grinding, polishing, and balancing to meet strict specifications.
Advanced facilities equipped with seven-axis CNC machining centers enable the machining of complex geometries in a single setup.
Depending on the diameter and material, milling can take considerable time, sometimes up to 400 hours.
The runners are dynamically balanced according to ISO 1940 standards to ensure they perform optimally under operational conditions.
Fabrication and Assembly of Francis Turbines
The fabrication and assembly of an 8.5 megawatt Francis turbine is a detailed and intricate process.
It begins with a thorough design phase where engineers collaborate with clients to understand their specific needs.
This phase includes creating 3D models which guide the manufacturing process.
The fabrication process is divided into several stages, starting with the turbine’s casing. Made from high-strength steel, the casing is fabricated using computer-controlled cutting machines for precise cuts and dimensions.
Once the casing is ready, attention turns to the turbine’s runner.
Following the fabrication of both components, the assembly phase begins.
This involves installing the runner onto the shaft, which is the heart of the turbine, converting water energy into rotational motion.
The runner is secured with nuts and bolts, and the shaft is then attached to the turbine’s main bearings, allowing for smooth rotation.
With the main components in place, the casing is lowered onto the assembly and aligned with the shaft and bearings.
After securing the casing, the turbine’s auxiliary systems are installed, preparing the turbine for rigorous testing.
Generator Manufacturing Process
Generators are essential for converting mechanical energy into electrical energy in hydroelectric plants.
The manufacturing process at the TES factory involves several key stages, starting with the production of laminations, which form the core of the generator.
The core is constructed from thin layers of steel laminations, stacked and insulated from one another to minimize eddy current losses and enhance magnetic properties.
Welding is used to join various components, like attaching end plates to the stator or rotor, ensuring structural integrity.
Tool making is another critical aspect, as specialized tools are necessary for creating various machine components.
The machining process involves cutting tools to shape and refine components like the stator and rotor, ensuring they meet precise specifications.
Each component undergoes a machining checkup to verify accuracy and ensure proper fit.
Following this, the winding and assembly process takes place, where wires are wound around the stator or rotor, a crucial step that significantly affects machine performance.
Finally, once the machine is fully assembled, it goes through a series of performance tests to confirm adherence to specifications.
The last step is paintwork, which protects the generator from corrosion and enhances its aesthetic appeal.
Pelton Runner Production
The Pelton runner is a vital component in hydroelectric power generation, specifically designed for high-efficiency energy conversion.
The manufacturing process begins with a thorough quality check of the raw materials, ensuring they meet stringent standards.
Once approved, the first machining stage involves rough milling, where advanced five-axis milling machines shape the runner to precise specifications.
This step is crucial in achieving optimal efficiency for the finished product.
Following rough milling, the runner undergoes finished milling, where specialized tools create a smooth surface, enhancing performance and reducing energy losses.
The final steps include grinding, polishing, and both static and dynamic balancing to ensure operational reliability.
Hydraulic Steel Construction
Hydraulic steel construction is essential for the structural integrity of hydroelectric plants, particularly in areas with significant water pressure.
In the Limmern pump storage plant, the shafts are reinforced with robust steel pipes, ensuring they can withstand the immense forces exerted by flowing water.
The manufacturing of these steel pipes is highly automated, utilizing computer-controlled processes for precision.
This ensures that every pipe meets exact specifications, crucial for their performance in high-pressure environments.
After rolling, the pipes undergo rigorous testing of weld joints to guarantee their strength and reliability.
Each joint is meticulously documented, ensuring adherence to safety and quality standards.
Dam Wall Construction Process
The construction of the dam wall at the Limmern pump storage plant is a monumental task that involves careful planning and execution.
The dam is designed with a triangular cross-section, providing stability and strength to hold back significant water pressure.
Material transportation is a logistical challenge, requiring over twenty thousand cable car rides to move excavated materials to the site.
The dam wall consists of sixty-eight interlocking blocks, each meticulously constructed to ensure durability and safety.
Each block is built in stages, with layers compacted using vibrators to create a solid structure.
The construction process is highly synchronized, with strict time limits between layer applications to ensure optimal bonding.
Limmern Pumped Storage Plant Overview
The Limmern pumped storage plant is a critical asset for energy management in Switzerland, featuring two powerful turbines with a combined capacity of two thousand megawatts.
This facility leverages the height difference between the Limmerne Sea and the Muttsey Lake to generate electricity efficiently.
Access to the site is limited, necessitating careful planning for transporting equipment and materials.
An access tunnel was constructed to facilitate the movement of personnel and machinery, ensuring a smooth workflow during construction.
Excavation of caverns for the turbines was a significant undertaking, involving both mechanical and explosive methods.
This phase was completed ahead of schedule, allowing for the timely installation of technical equipment.
Vernayaz Hydroelectric Power Plant Renovation
The Vernayaz hydroelectric power plant, operational since 1945, recently underwent extensive renovations to enhance its efficiency and reliability.
The project included critical repairs to the upper stator and the installation of new rotating diodes.
These upgrades were necessary due to wear and tear that had compromised the plant’s performance.
The renewal of the control command system ensures that the plant can effectively manage water flow and turbine output.
Upon completing the renovations, the plant successfully integrated the updated systems, marking a significant step forward in its operational capabilities.
