Abstract
Chloride salts are one candidate for a >700°C concentrating solar power (CSP) cycle, however, many reports from the literature suggest very high reaction rates between chloride salts and structural alloys. Historically, a specific methodology was established for evaluating halide salt compatibility based on solution kinetics. This study returned to that paradigm where the salts are purified and evaluated in sealed capsules before moving to a flowing experiment to determine a true corrosion rate in a temperature gradient for a commercial K–Mg–Na chloride salt. Isothermal testing focused on Ni-based alloys 230 and 600 at 600°C–800°C. The results indicated there were promising combinations of salt chemistry, temperature, and alloy composition that reduce the extent of reaction. The results of the first monometallic thermal convection loop of alloy 600 run for 1,000 hr with a peak temperature of 700°C showed low attack with rates ≤9 µm/yr.
| Original language | English |
|---|---|
| Pages (from-to) | 1439-1449 |
| Number of pages | 11 |
| Journal | Materials and Corrosion |
| Volume | 70 |
| Issue number | 8 |
| DOIs | |
| State | Published - Aug 2019 |
Funding
The authors would like to thank M. Stephens, T. Lowe, T. Jordan at ORNL for assistance with the experimental work and Haynes International for supplying alloy 244 and 230 specimens for testing. The isothermal testing parameters were developed in conjunction with B. Garcia-Diaz and L. Olson at SRNL, J. Vidal at NREL and L. Irwin at the Department of Energy's Solar Energy Technology Office (DOE SETO). Beneficial conversations were conducted with P. F. Tortorelli (retired ORNL) and S. Kung (EPRI). J. R. Keiser, and D. Sulejmanovic at ORNL provided many helpful comments on the manuscript. This study was funded by the US DOE's Office of Energy Efficiency and Renewable Energy, SETO under CSP award number 33873. This study honors the memory of our past corrosion group leaders at ORNL, J. H. DeVan and J. R. DiStefano and many others, who helped establish this paradigm and passed it on to the next generation. The authors would like to thank M. Stephens, T. Lowe, T. Jordan at ORNL for assistance with the experimental work and Haynes International for supplying alloy 244 and 230 specimens for testing. The isothermal testing parameters were developed in conjunction with B. Garcia‐Diaz and L. Olson at SRNL, J. Vidal at NREL and L. Irwin at the Department of Energy's Solar Energy Technology Office (DOE SETO). Beneficial conversations were conducted with P. F. Tortorelli (retired ORNL) and S. Kung (EPRI). J. R. Keiser, and D. Sulejmanovic at ORNL provided many helpful comments on the manuscript. This study was funded by the US DOE's Office of Energy Efficiency and Renewable Energy, SETO under CSP award number 33873. This study honors the memory of our past corrosion group leaders at ORNL, J. H. DeVan and J. R. DiStefano and many others, who helped establish this paradigm and passed it on to the next generation.
| Funders | Funder number |
|---|---|
| DOE SETO | |
| U.S. Department of Energy | |
| Office of Energy Efficiency and Renewable Energy | |
| National Renewable Energy Laboratory | |
| Electric Power Research Institute | |
| Solar Energy Technologies Office | 33873 |
Keywords
- concentrating solar power
- molten salt compatibility
- thermal storage
