Numerical investigation of double-walled direct absorption evacuated tube solar collector using microencapsulated PCM and nanofluid

CFD modeling of a triple‐walled direct absorption evacuated tube solar collector based on hybrid nanofluid/microencapsulated PCM

“…It is worth noting that the extinction coefficient of the binary nanofluid is around corresponding to the summation extinction coefficient of its individual components. 34 Additionally, in this case, the collector efficiency outperforms the individual use of each nanofluid.…”

“…It should be noted that these base fluids have a low absorption coefficient, therefore adding nanoparticles into them improves their optical properties. 34 Based on the high scattering property of Al O 2 3 and the superior absorption property of CuO, these nanoparticles are the appropriate choices for solar systems. In addition, if these two nanoparticles are dispersed in the base fluid, a binary nanofluid with excellent optical properties could result (Extinction coefficient = Scattering coefficient + Absorption coefficient).…”

“…EG is added to water to prevent the water from freezing at low temperatures. It should be noted that these base fluids have a low absorption coefficient, therefore adding nanoparticles into them improves their optical properties 34 . Based on the high scattering property of $${\text{Al}}_{2}{{\rm{O}}}_{3}$$ and the superior absorption property of CuO, these nanoparticles are the appropriate choices for solar systems.…”

“…They concluded that the capacity of the thermal energy has increased 16% with respect to paraffin/water. Karami et al 34 investigated the thermal performance of a double‐wall DAETC using MPCM and CuO nanofluid and reported that the efficacy of the collector increase by 4.53% and the heat loss lowers by 5.84%. According to various researchers, hybrid nanofluid/MPCM as an HTF enhances the thermal conductivity, heat transfer performance, and efficacy of the system in a variety of cases 35–37 …”

Efficient thermal energy conversion and storage enabled by hybrid graphite nanoparticles/silica-encapsulated phase-change microcapsules

“…Importantly, this approach enables the formation of a phase change slurry that can be utilized in DASCs, ultimately improving their solar utilization efficiency. [30][31][32] Currently, the majority of phase change microcapsule research involves SiO 2 -coated paraffin. [33][34][35] Paraffin is a highly promising organic substance for heat storage applications in the temperature range of −10 °C to 100 °C due to its enormous latent heat, superior chemical stability, and low cost.…”