Thermal‐hydraulic analysis of parabolic trough collectors using straight conical strip inserts with nanofluids

TY - JOUR

T1 - Thermal‐hydraulic analysis of parabolic trough collectors using straight conical strip inserts with nanofluids

AU - Abed, Nabeel

AU - Afgan, Imran

AU - Iacovides, Hector

AU - Cioncolini, Andrea

AU - Khurshid, Ilyas

AU - Nasser, Adel

N1 - Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2021/4

Y1 - 2021/4

N2 - In this study, we numerically investigated the effect of swirl inserts with and without nanofluids over a range of Reynolds numbers for parabolic trough collectors with non‐uniform heating. Three approaches were utilized to enhance the thermal‐hydraulic performance—the variation of geometrical properties of a single canonical insert to find the optimized shape; the use of nanofluids and analysis of the effect of both the aforementioned approaches; the use of swirl generators and nanofluids together. Results revealed that using the straight conical strips alone enhanced the Nusselt number by 47.13%. However, the use of nanofluids along with the swirl generators increased the Nusselt number by 57.48%. These improvements reduced the thermal losses by 22.3% for swirl generators with nanofluids, as opposed to a reduction of only 15.7% with nanofluids alone. The investigation of different swirl generator designs showed various levels of improvements in terms of the overall thermal efficiency and thermal exergy efficiency. The larger swirl generator (H30mm‐θ30°‐N4) with 6% SiO2 nanofluids was found to be the optimum configuration, which improved the overall collector efficiency and thermal exergy by 14.62% and 14.47%, respectively.

AB - In this study, we numerically investigated the effect of swirl inserts with and without nanofluids over a range of Reynolds numbers for parabolic trough collectors with non‐uniform heating. Three approaches were utilized to enhance the thermal‐hydraulic performance—the variation of geometrical properties of a single canonical insert to find the optimized shape; the use of nanofluids and analysis of the effect of both the aforementioned approaches; the use of swirl generators and nanofluids together. Results revealed that using the straight conical strips alone enhanced the Nusselt number by 47.13%. However, the use of nanofluids along with the swirl generators increased the Nusselt number by 57.48%. These improvements reduced the thermal losses by 22.3% for swirl generators with nanofluids, as opposed to a reduction of only 15.7% with nanofluids alone. The investigation of different swirl generator designs showed various levels of improvements in terms of the overall thermal efficiency and thermal exergy efficiency. The larger swirl generator (H30mm‐θ30°‐N4) with 6% SiO2 nanofluids was found to be the optimum configuration, which improved the overall collector efficiency and thermal exergy by 14.62% and 14.47%, respectively.

KW - Heat transfer

KW - Non‐uniform heating

KW - Parabolic solar trough collectors

KW - Solar thermal energy

KW - Swirl generators

KW - Thermal and hydraulic performance

UR - http://www.scopus.com/inward/record.url?scp=85103023164&partnerID=8YFLogxK

U2 - 10.3390/nano11040853

DO - 10.3390/nano11040853

M3 - 文章

AN - SCOPUS:85103023164

SN - 2079-4991

VL - 11

JO - Nanomaterials

JF - Nanomaterials

IS - 4

M1 - 853

ER -