Collective Summary of sCO2 Materials Development Part II: High-Temperature Alloy Corrosion Behavior within Compact Heat Exchangers.
- Sandia National Lab. (SNL-CA), Livermore, CA (United States)
- Peregrine Turbine Technologies, Wiscasset, ME (United States)
- BraytonEnergy, Hampton, NH (Unites States)
Materials compatibility is a major concern for the design and operation of supercritical carbon dioxide (sCO2) power cycles. Two areas were recently identified for which very little prior knowledge was available. These were the behavior of polymer materials in low-temperature sCO2 environments as well as the high-temperature corrosion behavior for alloys that have been fabricated into compact heat exchangers. A critical need exists to increase understanding in both areas. As such, the Sandia sCO2 Materials Development program initiated a series of experiments for both areas in FY19. The progress that has been made in understanding the behavior of polymers in sCO2 was summarized in the Part I report, while this Part II report describes progress in the area of compact heat exchanger corrosion. For the compact heat exchangers being developed for use in supercritical CO2 power cycles, alloy corrosion is important to understand as it may lead to reduced flow path area, reduced heat transfer, and blocked flow channels. The fabrication of these heat exchangers involve thermal processes such as brazing or diffusion bonding, where the influence of these processes on the corrosion behavior of the alloys is unknown. Candidate alloys for these heat exchangers are typically evaluated for corrosion behavior as witness coupons, without being subjected to these thermal processes. To close this gap in understanding, a series of experiments were completed that utilized small heat exchanger samples subjected to flowing CO2 for 500 hours at 750°C. Small sections of the heat exchanger samples were characterized before and after the 500 hour exposure in order to characterize the oxide growth in the channels as well as the hardness of the alloys. Results are compared to witness coupons of the same alloys.
- Research Organization:
- Sandia National Lab. (SNL-CA), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE Office of Nuclear Energy (NE); USDOE National Nuclear Security Administration (NNSA)
- DOE Contract Number:
- AC04-94AL85000; NA0003525
- OSTI ID:
- 1592948
- Report Number(s):
- SAND-2019-14554R; M2ST-19SN0202012; 682541
- Country of Publication:
- United States
- Language:
- English
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