High-Temperature Thermal Characterization and Material Developments for Next-Generation Concentrating Solar-Thermal Systems

High temperature thermal transport processes and materials are important for the next-generation concentrating solar-thermal (CST) systems, including concentrating solar power (CSP), solar thermochemical fuel production, solar thermal energy storage, and solar thermal decarbonization. However, characterizing high-temperature thermal transport is challenging, especially on the corrosive heat transfer media such as molten salt and flowing particles. Additionally, there is a need for materials that are stable at high temperatures and can provide desirable optical, thermal, and thermochemical functionalities. In this talk, we will present our recent work on these two fronts. First, we have developed a non-contact high-temperature thermal transport characterization technique named “modulated photothermal radiometry” (MRP), which can accurately measure thermal conductivity of molten salts and granular media, in both the static and flowing states, at high temperature. In particular, the MPR measurements on flowing ceramic particles reveal that thermal transport is substantially altered compared to their static counterparts. This has a major impact on the design of particle heat exchangers. Furthermore, the MPR technique is suitable for in-situ and operando measurements, as has been demonstrated in a moving particle heat exchanger prototype. Second, we have been working on the development of high temperature stable spinel oxide, including high-entropy spinel oxides (HESOs), which can be used to coat ceramic particles to enhance their optical and thermal stability, thus showing promises as multi-functional materials for next-generation high-temperature CST systems.

References:
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Chung, K.M., Feng, T., Zeng, J., Adapa, S.R., Zhang, X., Zhao, A.Z., Zhang, Y., Li, P., Zhao, Y., Garay, J.E. and Chen, R., 2023. Thermal conductivity measurement using modulated photothermal radiometry for nitrate and chloride molten salts. International Journal of Heat and Mass Transfer, 217, p.124652.
Adapa, S.R., Zhang, X., Feng, T., Zeng, J., Chung, K.M., Albrecht, K.J., Ho, C.K., Madden, D.A. and Chen, R., 2024. Heat transfer coefficients of moving particle beds from flow-dependent thermal conductivity and near-wall resistance. Solar Energy, 282, p.112960.
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