Sulzer secures contract for major concentrated solar power project in China

In a significant move towards renewable energy, Sulzer has been chosen to supply both hot and cold molten salts pumps for a major concentrated solar power (CSP) Tower project in China.

The planned 100 MW site is part of an ambitious programme driven by the increasing demand for sustainable energy sources in China and around the globe. Sulzer’s expertise in this sector has facilitated numerous successful projects capable of delivering 24-hour power from solar energy.

Molten salts, used in the nuclear industry for nearly 70 years, have seen Sulzer involved in designing and manufacturing pumps to transfer high-temperature fluids around cooling circuits. The company pioneered the technology for the solar industry over 15 years ago, enabling overnight heat energy storage.

The process involves pumping molten salt to solar collectors, where its temperature rises from approximately 300 °C to 600 °C. The heated salt is then stored in a tank and ytransferred to a heat exchanger, where the thermal energy generates steam to power a turbine/generator. This circuit acts as a thermal battery, allowing solar plants to deliver power continuously in optimal solar conditions.

Sulzer boasts a long history of delivering molten salt pumps to solar installations worldwide, including recent projects in China. The 100 MW CSP Tower project marks the first of its kind to utilise Sulzer pumps for both hot and cold circuits. Three cold molten salt pumps, fitted with 2.6 MW motors, will extend 18 metres below the base plate into the cold molten salt tank, complemented by two hot pumps. All pumps will be manufactured at Sulzer’s Suzhou plant.

One significant challenge was the increased operating pressure required in the molten salt circuits. Smaller sites typically operate at around 50 bar, but this project required a 100 bar supply pressure. Each pump was custom-built to accommodate the higher pressure and slightly larger power requirement. Key aspects, such as the throttle bushing and bush bearing design, were meticulously assessed, engineered, and tested before manufacturing commenced.

The end-user aimed to achieve several objectives, including sourcing key equipment from international brands, ideally manufactured in China, while remaining cost-effective. Sulzer met all these objectives, with the bare-shaft pump engineering completed in Europe and manufacturing collaboratively undertaken in Belgium and China. Additionally, Sulzer offers a comprehensive support package through its local service centre, streamlining spare parts inventory for the end-user.

Sulzer’s local engineers will support the installation and commissioning of the equipment. Given their length, the pumps will be assembled on-site before installation in the storage tanks.

This installation follows several other successful projects in China for Sulzer, including three hot pumps for another 100 MW CSP and six hot and five cold pumps for a 42 MW parabolic trough installation.

The 100 MW CSP Tower project is a testament to Sulzer’s commitment to advancing renewable energy technology, ensuring a sustainable and reliable energy future.