Transient thermal response and regulation of transparent silica aerogels under fluctuating solar irradiance
*Correspondence to:
Shuai Deng, State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China. National Industry-Education Platform for Energy Storage (Tianjin University), Tianjin 300350, China.
E-mail: sdeng@tju.edu.cn
Meng Lin, Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China; SUSTech Energy Institute for Carbon Neutrality, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China. E-mail: linm@sustech.edu.cn
Meng Lin, Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China; SUSTech Energy Institute for Carbon Neutrality, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China. E-mail: linm@sustech.edu.cn
Thermo-X. 2027;3:202636. 10.70401/tx.2026.0039
Received: August 13, 2026Accepted: October 16, 2026Published: October 16, 2026
This manuscript is made available in its unedited form to allow early access to the
reported findings. Further editing will be completed before final publication. As
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Abstract
Transparent silica aerogels can reduce heat loss from solar receivers while maintaining high solar transmission, but their performance under fluctuating irradiation is governed by the coupled effects of solid conduction, non-gray thermal radiation, and time-dependent fluid heat extraction. Here, we develop and experimentally validate a transient 5-band model for an aerogel-covered solar fluid heater. The model resolves wavelength-dependent radiative transport within the aerogel and couples it with heat conduction and forced convection. We show that conduction and radiation cannot be reconstructed from isolated calculations because both adjust to a shared temperature field. Direct superposition overpredicts the coupled heat flux at the aerogel-absorber interface by 25–31%, while appearing accurate at the external aerogel surface because the internal coupling effects compensate spatially. Flow regulation introduces a further trade-off between outlet temperature rise and response speed. Simulations driven by measured global horizontal irradiance in Shenzhen show that the flow adjustment interval mainly controls short-term temperature stability, whereas the irradiation regime and periods of flow interruption dominate the integrated thermal performance. These results establish a transport-based framework for understanding and regulating transparent aerogel covered solar receivers under variable solar input.
Keywords
Transparent silica aerogel, transient heat transfer, participating medium radiation, conduction-radiation coupling, solar fluid heating, flow regulation
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Li S, Yang N, Li F, Liu S, Li C, Deng S, et al. Transient thermal response and regulation of transparent silica aerogels under fluctuating solar irradiance. Thermo-X. 2027;3:202636. https://doi.org/10.70401/tx.2026.0039
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Li S, Yang N, Li F, Liu S, Li C, Deng S, et al. Transient thermal response and regulation of transparent silica aerogels under fluctuating solar irradiance. Thermo-X. 2027;3:202636. https://doi.org/10.70401/tx.2026.0039
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