OPERATION OF LARGE-SCALE PUMPS AND VALVES IN MOLTEN-SALT

The molten salt pump and valve (P&V) test loops at Sandia National Lab oratories (SNL) National Solar Thermal Test Facility (NSTTF) operated between Jan. 1988 and Oct. 1990. The purpose of the P&V test was to de monstrate the performance, reliability, and service life of full-scale hot and cold salt pumps and valves for use in commercial central rece iver solar power plants. The P&V test hardware consists of two pumped loops; the ''Hot Loop'' to simulate the hot (565-degrees-C) side of th e receiver and the ''Cold Loop'' to simulate the receiver's cold (285- degrees-C) side. Each loop contains a pump and five valves sized to be representative of a conceptual 60-MW(e) commercial solar power plant design. The hot loop accumulated over 6700 hours of operation and the cold loop over 2500 hours of operation. This project has demonstrated that standard commercial scale pump and valve designs will work in mol ten salt. The test also exposed some pitfalls that must be avoided in specifying such equipment. Although certainly not all of the pitfalls were discovered, careful design and specification should result in rel iable or at least workable equipment.