On July 2, Jiangsu Fengcheng-Meili 500 KV Power Transmission and Transformation Project, the largest new energy power transmission channel across the Yangtze River in China, designed by China Energy Construction Jiangsu Institute, was officially completed and put into operation!
Jiangsu Fengcheng-Meili 500 KV power transmission and transformation project is a key project of the national "13th Five-Year" power planning. It starts from Taizhou Fengcheng 500 KV substation in the north and ends at Wuxi Meili 500 KV substation in the south. Among them, the large crossing section of the project is the sixth high-grade power channel crossing the Yangtze River in Jiangsu Province, and the project is also the most technically difficult 500 kilovolt cross-river interconnection transmission project in the history of China's power construction. The land along the
Yangtze River Golden Waterway is expensive, because the crossing tower is controlled by multiple factors such as ecological protection of the Yangtze River, local planning and natural terrain, which makes the design conditions of the crossing tower very harsh and difficult. Facing the difficulties, the
design project team created five world firsts in the field of power transmission in this project: tower height (385 meters), tower root distance (75 meters), shaft lifting height (378 meters), anchor bolt group weight (9.2 tons) and pole lifting height (432.4 meters). For the first time, the
three innovative technical schemes were applied
in the main material of steel tube concrete of iron tower, and the new annular steel skeleton component was applied.
The annular steel sheet and the annular connecting plate are connected to form a closed ring, which divides the concrete into two parts. The core concrete is constrained by the steel tube and the inner ring, and is in a three-dimensional compression state, which can effectively improve the axial stiffness, bearing capacity and ductility of the component. Compared
with the conventional concrete-filled steel tubular column, the axial stiffness and bearing capacity of the composite member can be increased by more than 10%, the steel weight can be saved by about 160 tons, and the material cost of the tower can be reduced by about 1.8 million yuan, which has remarkable economic and social benefits.
It is the first time to apply a new type of inner ring steel skeleton component in the main material of steel tube concrete of iron tower. It
is the first time to apply low-alloy quenched and tempered cast steel nodes in key nodes of iron tower.
The spatial integral pouring technology can avoid the intersection line cutting and complex welding process, eliminate the local residual stress caused by the overlapping weld, and the node structure and stress distribution are reasonable. Compared
with the conventional welding node, the cast steel node avoids a lot of complex welding work in the core area of the node, saves 60 hours of working hours for a single node, and reduces the labor cost by about 60000 yuan according to the calculation of 1000 yuan per hour for senior welders. The cast steel tubular joint can effectively improve the mechanical performance of the joint while greatly reducing the labor cost, and has important social and economic benefits for ensuring the reliability of important power structures including long-span super-high towers. It is the
first time to apply low-alloy quenched and tempered cast steel nodes
in key nodes of iron towers, and the first time to apply G6a steel core high-strength aluminum alloy strands in 500 kV transmission lines.
Compared with the commonly used G4A super-strong steel core high-strength aluminum alloy stranded wire, aluminum-clad steel stranded wire, carbon fiber conductor and some newly developed "low sag" conductors, the conductor recommended in the design has the advantages of mature manufacturing process, R eliable materials, high safety redundancy of steel core strength, excellent sag characteristics, low power loss, convenient construction, and the annual cost is the best. The best unification of safety and economy is realized. It is the
first time to apply various innovative design methods
of G6a steel core ultra-strong steel core high-strength aluminum alloy stranded wire
in 500 kV transmission line. The world's first high transmission tower is different from the general transmission tower design. The members of the design project team carefully verify and boldly innovate. Among them, many design methods are applied for the first time in the design of large crossing in China, which effectively guarantees the safety, economic benefits and design efficiency of the project. The direct analysis design method
based on the optimization objective of bearing capacity and displacement performance is adopted. The design method
of the whole series of structures with shafts is adopted. The refined calculation design method of wire tension and sag considering the influence of electrical accessories is adopted. UNK2 2 adopts the state space design and calculation method 0 HTML 0 UNK2 3 for the foundation coupling beam. After the project is put into operation, it is estimated that about 26 billion degrees of clean electricity will be sent from the north bank of the Yangtze River to the south bank every year, which can meet the daily electricity demand of about 8 million households and reduce carbon dioxide emissions by about 10 million tons every year. Promote the orderly substitution of clean energy for fossil energy, help the construction of new power system in China, and provide strong support for the development of energy integration in the Yangtze River Delta. 0 HTML0 UNK2 4 Now, on the 385-meter Yangtze River crossing transmission tower, you can personally feel the majesty of the world's highest transmission tower and the strength of China's infrastructure. China Nengjian will continue to improve its professional and technical capabilities and continue to build high-quality projects for the national energy industry! 0HTML0UNK25
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