A major concentrated solar power (CSP) project in China selected Sulzer, a global fluid engineering company, to supply both the hot and the cold molten salts pumps for the installation. The planned 100-MW solar project will feature technology designed to deliver electricity from solar energy 24 hours a day. Molten salts have been used in the nuclear industry for almost 70 years, and Sulzer has been involved in the design and manufacture of the pumps that transfer the high-temperature fluids around the cooling circuits. The company was involved in pioneering the technology for use in the solar industry more than 15 years ago, enabling heat energy to be stored overnight.
A major concentrated solar power (CSP) tower project in China has selected Sulzer to supply both the hot and the cold molten salts pumps. Source: Shutterstock Molten salt is pumped to solar collectors (tower or parabolic mirror fields) where its temperature increases from around 300C to up to 600C. The high-temperature salt is then stored in a tank and transferred to a heat exchanger, where the thermal energy is used to create steam that will generate power using a turbine/generator. This circuit acts as a thermal battery, which enables solar plants to deliver power round-the-clock in good solar conditions. Sulzer has a track record of delivering hot and cold molten salt pumps to solar installations around the world, including recent projects in China. The 100-MW CSP Tower project is the first of its type to use Sulzer pumps for both the hot and the cold circuits. The three cold molten salt pumps will be fitted with 2.6-MW motors, and will extend 18 meters below the base plate into the cold molten salt tank. These will be matched with two hot pumps, with all the pumps being manufactured in Sulzer’s Suzhou, China, plant, located in Jiangsu Province. The most significant challenge in this project was the increased operating pressure required in the molten salt circuits. Sites with smaller outputs normally operate at around 50 bar, but this project needed a 100-bar supply pressure from the pumps.