Facility to Alleviate Salt Technology Risks (FASTR): Commissioning Update

Abstract

The Facility to Alleviate Salt Technology Risks (FASTR) is a versatile, high-temperature (>600°C) molten chloride salt test facility designed to enable a variety of testing to advance the Generation 3 concentrating solar power molten salt technology. FASTR includes a salt preparation system and a forced-flow test loop with a suite of instrumentation. The FASTR loop can operate at 725°C with flow rates of 3-7 kg/s, and it includes heated and cooled sections and swappable components to facilitate testing of future vendor-supplied hardware. The salt preparation system supplies large batches of clean salt for use in the FASTR forced-circulation loop. This report summarizes the shakedown and initial operation of the FASTR forced-circulation loop through December 2022.

Digital Twin Development of FASTR

“…Eight IR lamps are currently available, which can provide approximately 103 kW th to the heater plate, expandable to 24 lamps in the future to provide ∼310 kW th . For the initial isothermal salt tests, trace heating was applied to the front and back faces of the heater block using heat tapes [2].…”

“…This model was developed before any of the benchmarking tests, and the isothermal salt tests were conducted because of unforeseen experimental delays. With the release of the initial loop commissioning report [2] earlier this year, further discussions were held with the facility PI, Dr. Kevin Robb. From the discussions, it emerged that the Modelica model required modifications, the primary modification being to change the model to a closed tank system.…”

“…There are two liquid and two gas ports: one inlet and one outlet port for each phase. For the initial set of tests, the report [2] does not specify the gas flow rates entering/exiting the two tanks. Therefore, the gas flow rates were arrived at indirectly by controlling for the liquid level or gas pressure using standard proportional-integral-derivative (PID) controllers.…”

“…As part of the commissioning of the loop, the pump manufacturer ran a series of tests on the pump using water in an open pit, at room temperature and pressure. These tests were used to develop pump curves at four speeds: 500 rpm, 1050 rpm, 1200 rpm, and 1800 (100%) rpm [2]. The pump was then delivered to be installed in the FASTR loop and was tested using a mini-loop, which started at the pump discharge, raised vertically, passed over a pump motor, and then returned to the pump tank inlet.…”

“…All other pipe sections model a pipe wall made of C-276 with a thickness corresponding to schedule 40 pipe and also include a fiber glass insulation. The thickness of the fiber glass insulation and the external heat transfer coefficient would have to be optimized using the heat loss tests that were performed in the facility at different temperatures using the cover gas [2]. The heat loss tests showed that the heat exchanger dominated the trace heating requirements; and for the salt flowing operations, tubular heaters located in the inlet and outlet plenums of the heat exchanger are required to ensure that the salt temperature does not fall below the freezing margin.…”