my country’s first real 3D printed impulse turbine runner was successfully developed

The impulse turbine is one of the four major models of hydroelectric power generation. The runner is the key component of the impulse hydroelectric power plant. However, because the impulse turbine runner is equipped with 20-25 curved water buckets on the hub, its curved shape is very complex. At present, the runners developed by domestic companies are mainly based on the model runner profiles of the 1980s abroad, and are developed by the process of integral casting and manual polishing.

According to Harbin Electric Motor Factory Co., Ltd. of Harbin Electric Group, China’s first real-machine runner for additively manufactured impulse turbines was successfully developed and delivered by the company, marking Harbin Electric Motor’s additive manufacturing (3D printing) Technology research and application have entered a new stage of development.

The big challenge of the water wheel

Harbin Electric Group Electric Co., Ltd. entered in 20133D printingField, which was developed earlier in the country3D printingTechnology application research unit, and in 2015 successfully manufactured the first domestic model water turbine that can be applied to hydraulic test3D printingNon-metallic model runner, finished model runner metal3D printingTechnology feasibility study and preliminary research and development.

Harbin Electric Group Motor Company is based on the model runner3D printingThe project team established the “Hydraulic Turbine Runner Additive Manufacturing Double Innovation Team”, and relying on platforms such as the State Key Laboratory of Hydropower Equipment and the National Hydropower Equipment Engineering Technology Research Center, based on industry development, market demand-oriented, and industry-oriented The focus and difficulty of internal product manufacturing are the most representative impact runner among hydraulic turbine runners3D printing-Additive manufacturing as a breakthrough point, in-depth application research and development innovation.

Attempt to overtake in a curve

The application of this technology in the manufacturing of such large-scale structural parts is an important direction for the current research and development of additive manufacturing technology, and it is also facing many technical problems that need to be overcome urgently. The successful development of China’s first additive-manufactured impulse runner and the operation verification of future power stations can provide an effective and feasible new solution for hydraulic development of ultra-high head and ultra-large-capacity impulse runner manufacturing.

High-safety impact runner

According to the structural characteristics and operating conditions of the impact runner, the project team created a unique high-safety additive manufacturing structure, developed a robot-based additive manufacturing process for runners, and formed a complete and independent intellectual property rights Additive manufacturing technology for runners.

The subsequent manufacturing process verifies the application of this technology, greatly reduces the manufacturing cost, cycle and difficulty of the impact runner, has good economics, meets R&D expectations, and has a broad market prospect. In the near future, the additive manufacturing impact runner can be installed and operated, and its operational safety, life and efficiency will be further evaluated and verified.

The design process of the water wheel requires the organic combination of CAD/CAM/CAE/CFD technology, through the processsimulationWith the analysis of the rigidity and strength of the runner, use the results of the analysis to modify the structure of the runner until a runner with excellent hydraulic performance, structural reliability, manufacturability and other aspects is obtained.In addition to the direct3D printingRealize the manufacture of water wheel runners, internationally3D printingThe combination of sand mold and casting realizes the manufacture of large-scale water wheel runners.Talk about3D printingThe application combined with casting requires an understanding3D printingThe advantages of3D printingThere are two major characteristics: 1 is modelless, the corresponding advantage is as a shortcut to the R&D trial production stage, accelerating the iterative process, and reducing R&D costs; 2 is not sensitive to the complexity and cost of the product, and the corresponding advantage is suitable for innovation and subversion of products Design makes product design dominated by function realization.The common misunderstanding in the domestic foundry industry is that only the3D printingThe first advantage will be3D printingSand mold or3D printingPMMA investment mold is used in the trial production and development stage of the product, that is to say, the product processed is still the traditional design product, and the product is not processed.3D printingFor the design of innovative products from the source.

3D printingThe biggest advantage is that it is used to make designs that cannot be achieved by traditional methods, including thin-walled and complex shapes. In the automotive field, it can be used3D printingA specially designed cooling system (such a design cannot be manufactured through traditional manufacturing processes) to achieve higher product performance.

Generally speaking, the larger the casting size, the more sand cores need to be manufactured.3D printingThe technology used in the manufacture of large-scale casting sand molds has challenges such as sand core venting, sand core fixing, and external cooling iron setting and fixing.

Not only that, these sand molds usually have to meet the requirements of ultra-high temperature, ultra-thick and wide section, high pressure, clean, and non-destructive during the metal casting process. In this regard, voxeljet successfully manufactured the 3.2-ton Pelton turbine impeller through cooperation with the pump manufacturer.

Impeller for Pelton turbine, source voxeljet-Vojet

voxeljetThe characteristic is based on the large format of the binder spray3D printingTechnology. For this Pelton turbine impeller, due to its huge size, traditional manufacturing methods usually need to be divided into different parts to complete the casting process, and then 18 blades are welded to the impeller by welding. This process Very complicated, time-consuming and expensive.

Passed voxeljet-Voxel large industrial grade3D printingThe machine VX4000 completed all the work at one time. The printing area of ​​the VX4000 is 4,000 x 2,000 x 1,000 mm (length x width x height). The printing process takes 72 hours, after which only KBL’s proprietary coating technology is required for post-processing.

(Editor in charge: admin)