Stepping on the bumps and building the road to localization. The 1250 MW half-speed nuclear turbine generator components of the Sanmen Nuclear Power Project are not only complex in structure, but also have strict processing requirements, and the tonnage is heavy and the size is large, making the manufacturing difficulty unprecedented. The shaft diameter of the project is 1.88 meters, completely breaking the historical record of the largest diameter of 1.2 meters processed by Harbin Electric. However, the accuracy of some dimensions is 0.01 mm, which is much higher than the machining accuracy of the shaft workpiece.
In order to ensure the smooth production of nuclear power shafts, Harbin Electric actively organized technical research and successfully broke through many problems. The same process was also carried out in the process of manufacturing other components of the three-door project. From the main machine to the auxiliary machine, from the welding of the base and end cover to the rotor down line, ventilation test, to the stator frame assembly, hydraulic test and unit type test, many different problems are solved by different methods. Different difficulties were overcome in different ways, and many "stumblers" that hindered the manufacture of three generations of nuclear power products in front of Harbin Electric Motors were turned into "stepping stones."
In April 2011, nuclear power stator base machining; in May 2012, the stator was off the assembly line; in July 2012, the rotor was off the assembly line; in October 2013, the final assembly type test; on December 20, 2013, the stator frame was successfully shipped. .
In 2014, in the production of AP1000 nuclear steam turbine generators in Haiyang, Tianwan and other projects, Harbin Electric has successively broken through dozens of manufacturing difficulties and technologies such as punching, stator coil, rotor coil, water box and outlet box. The problem of comprehensive localization and manufacturing of key components requiring strict and high technology content has brought the level of localized manufacturing of China's three generations of nuclear power products to a new level.
Advance China's nuclear power autonomy process. Although the first victory of the three-generation nuclear power turbine generators has been achieved in the three-door nuclear power project, Harbin Electric has not relaxed the promotion of the full-scale localization of the third-generation nuclear power equipment.
Faced with the fact that most of its workpieces and materials still need to rely entirely on foreign imports, Harbin Electric strives to explore the past in many aspects, and through cooperation with domestic high-quality suppliers, has embarked on a win-win situation that guides peer companies to jointly promote localization. the road.
Harbin Electric has developed and implemented a three-generation nuclear power product metal materials and insulation materials localization promotion plan: on the one hand, looking for qualified suppliers in domestic counterparts, providing relevant technical standards after conversion and obtaining in the manufacture of Sanmen nuclear power project products The experience helps the supplier to carry out R&D and manufacturing of raw materials for the three generations of nuclear power products; on the other hand, it actively communicates with Mitsubishi Corporation to coordinate its qualifications for enterprises and products that have reached the requirements of the three generations of nuclear power standards in China. Guide the peer enterprises to develop and advance in the field of nuclear power, and further improve the localization level of nuclear power project products through the application of the three-generation nuclear power domestic materials.
The localization of nuclear forgings for nuclear power is part of the localization plan for Harbin's metal materials. It is recognized as one of the world's most comprehensive products with the highest comprehensive performance requirements. Compared with ordinary forgings, the requirements for the purity, uniformity and forging density of steel ingots are extremely high.
Facing the difficulty of promoting the localization of nuclear power manufacturing, Harbin Electric established a localization team for nuclear power ring forgings composed of technology, procurement, management and other departments. With the industry's authoritative organization, the Large Motor Research Institute as the core, it leads the domestic manufacturers and researchers involved in the trial production. The colleges and universities have researched and explored the technical difficulties and key points in the localization of nuclear power projects, and successfully found a reasonable process route and material manufacturing plan.
After more than 10 special technical exchanges, more than 50 (secondary) tests and more than 600 days of hard work, the company finally solved many problems and successfully completed the center ring, spacer ring, fan ring, fan seat ring, collector ring, etc. The localized manufacturing of ring forgings for AP1000 nuclear power passed the certification of Mitsubishi Corporation.
At the same time, it is difficult to overcome the technical difficulties and achieve localized manufacturing, such as tough copper, end cap high-strength bolts, locking sleeves, double-hole locking pieces, spinal thread plugs, neutral point bus bars and terminals, etc. Insulation materials and parts such as polyester film tape, epoxy glass bolts, and thermosetting insulating tubes have a total of 230 types.
According to Harbin's three-generation nuclear power material localization promotion plan, the localization rate of the third-generation nuclear power metal materials has reached 95%, and the localization rate of insulating materials has reached 49%. At present, Harbin Electric is applying these materials and components that have been successfully localized to the production of Tianwan and Haiyang nuclear power projects.