The Next Decade of Wind Power: the “Size Anxiety” of Casting Plants and the Way Out

When the wind turbine blades with a diameter of more than 250 meters draw arcs in the clouds, and when the power of a single wind turbine exceeds 15 megawatts (MW) – which is equivalent to the traction power of 20 high-speed train sets, the wind power industry is moving towards the “super-large wind turbine era” at an astonishing speed. However, the core components that support these “giants” – wind turbine castings- are facing unprecedented challenges: how to find a breakthrough in the triangular relationship between size, weight and strength has become a “survival question” that casting companies must answer.

Large-scale wind turbines: the double shackles of casting size and weight

Traditional wind power castings are mainly composed of hubs, main shafts, bearing seats and other components, but when the power of a single unit jumps from 5MW to more than 15MW, the size and weight of these components begin to break through physical limits. Taking the hub as an example, the hub diameter of a 15MW wind turbine can reach more than 5 meters, and the weight of a single piece exceeds 60 tons, which is equivalent to the total weight of 40 family cars. If integral casting is adopted, not only is a sand box with a diameter of more than 10 meters required (only a few foundries in the world have this capability), but also process problems such as uneven cooling of molten metal during pouring and soaring shrinkage defect rate.

Even more difficult is the weight problem. If the weight of the casting increases linearly with the power, the bottom of the tower of a 15MW wind turbine will bear a static load of more than 1,000 tons, superimposed with dynamic stresses such as wind load and earthquake, which will place extremely high demands on the foundation and material costs. According to industry estimates, for every 10% increase in casting weight, the life cycle cost of electricity (LCOE) of the wind farm will increase by 3%-5%. Therefore, how to “slim down” while ensuring strength has become the core contradiction of casting design.

Split casting and lightweighting: “addition and subtraction” of casting technology

Faced with the dual pressures of size and weight, the industry is breaking through with “split casting + lightweight design”.

The split casting solution disassembles large castings into multiple modules for separate molding, and then combines them through precision assembly or welding. For example, a company decomposes the wheel hub into three fan-shaped modules, and the weight of each module is controlled within 20 tons. This not only reduces the difficulty of casting but also realizes the commonality between different models through modular design, shortening the R&D cycle. The main shaft adopts the “hollow shaft + flange connection” structure, which reduces the weight by 30% compared with the solid shaft while ensuring torsional stiffness.

Lightweight design relies on material science and topological optimization technology. The application of high-strength ductile iron (QT400-18AL) can reduce the wall thickness of the casting by 20% while maintaining fatigue resistance, and the topological optimization algorithm based on AI can simulate the optimal path of material distribution and eliminate redundant structures. For example, a bearing seat is designed with a bionic honeycomb structure, which reduces the weight by 15% under the same load and increases the material utilization rate by 25%.

3D printing sand mold: a “key leap” to break through size limitations

In addition to split casting and lightweight, 3D printing sand mold technology is opening up a new dimension for casting manufacturing. Traditional sand molds rely on wooden or metal molds, which have a long production cycle, high cost, and make it difficult to achieve complex inner cavity structures. 3D printing sand molds can directly print sand molds with conformal cooling water channels and lightweight lattice structures by stacking refractory sand grains layer by layer, and can produce single or small batch castings without opening molds.

A casting company has successfully applied this technology to produce 15MW wind turbine main shaft sand molds: by optimizing the printing layer thickness and binder ratio, the sand mold dimensional accuracy reaches ±0.3mm, and the inner cavity surface roughness is reduced to Ra6.3μm, which significantly improves the metal liquid filling capacity; at the same time, the conformal water channel increases the cooling efficiency of the casting by 40%, and the shrinkage defect rate drops to below 0.5%. More importantly, 3D printing breaks through the size limitations of traditional sandboxes and can theoretically manufacture castings of any diameter, paving the way for the research and development of 20MW+ wind turbine castings.

The future has come: the “size revolution” of casting plants

From split casting to lightweight design, from 3D printing sand molds to intelligent quality inspection, the upgrading of casting technology is driving the wind power industry to evolve in a more efficient and economical direction. It is predicted that by 2030, the proportion of wind turbines above 15MW will exceed 60%, and the proportion of casting costs in the total cost of wind turbines will drop from the current 12% to less than 8%. This “size revolution” is not only a technological breakthrough, but also the result of collaborative innovation in the industrial chain. When casting plants form a “technical alliance” with wind turbine manufacturers, material suppliers, and 3D printing companies, the “super-large era” of wind power can truly take root.

In the wind power competition of “asking for energy from the sky”, casting companies are using technology as a spear to pierce the shackles of size and weight. And every breakthrough they make is “supporting” the future of clean energy for mankind.

Wind Power Equipment Parts Supplier

Luoyang Fonyo Heavy Industries Co., Ltd, founded in 1998,is a manufacturer in cast railway parts. Our factory covers an area of 72,600㎡, with more than 300 employees, 32 technicians, including 5 senior engineers, 11 assistant engineers, and 16 technicians. Our production capacity is 30,000 tons per year. Currently, we mainly produce casting, machining, and assembly for locomotive, railcar, high-speed trains, mining equipment, wind power, etc. Our products have been exported to Russia, the United States, Germany, Argentina, Japan, France, South Africa, Italy and other countries.
Contact: Stella Liu
Email:sales@railwaypart.com
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