Sandia National Laboratories is seeking an industry partner to market a turbine system that could substantially improve energy efficiency in small modular nuclear reactors.
The system uses carbon dioxide in a closed-loop “Brayton-cycle” turbine to crank up electric conversion from heat, said Gary Rochau, manager of the advanced nuclear concepts group at Sandia’s Nuclear Energy and Fuel Cycle Technologies Center.
A supercritical CO2 Brayton-cycle system can reach 50 percent conversion efficiency. Typically, you only get 30 percent conversion with an [air-based] steam engine.
The system is much less expensive to build because it’s very compact, Rochau said. Given its size, it can’t be used in large power plants like coal-fired generators. But it’s well-suited for tiny plants, such as small modular nuclear reactors.
Sandia researchers have worked with this single compressor research loop to build a closed-loop Brayton-cycle turbine that uses supercritical carbon dioxide to increase the conversion of heat to electricity in turbine generators
The pump was delivered and installed in the Molten Salt Test Loop (MSTL) system at Sandia National Laboratories’ National Solar Thermal Test Facility (NSTTF). MSTL is designed to allow customers and internal researchers to test Concentrating Solar Power components and subsytems with nitrate salts flowing at realistic pressure, temperature, and flow rates. The pump, a 9-stage, stainless steel, vertical turbine pump manufactured by Flowserve, is driven by a variable frequency drive that will allow a broad range of flow and pressure conditions in the experimental test loops. The MSTL system is design to provide salt up to 400gpm, 585C, and 600psi to the 3 parallel test loops where experiments can be installed.