Influence of absorber tube geometry on the thermal performance of a parabolic trough solar collector under heating cycles for hot water production

Iliquin-Fernandez R.E.; Ligue-Tocas J.J.; Canaza F.I.E.; Mena-Chacon L.M.; Chappa M.Y.; Rituay P.; Mori-Mestanza D.; Vela-Vargas K.J.; Ramirez C.M.O.; Barrena-Gurbillón M.A. · Next Energy (2026) · DOI: 10.1016/j.nxener.2026.100729

Resumen

The growing demand for thermal energy and the need to reduce the use of fossil fuels have driven the development of solar thermal technologies. Among them, parabolic trough solar collectors stand out for their ability to concentrate solar radiation and produce heat at relatively high temperatures for thermal applications. The objective of the research was to experimentally evaluate the thermal performance of a parabolic trough solar collector through heating cycles, comparing two absorber tube configurations: linear configuration (C1) and triangular tube arrangement (C2), to determine the configuration that allows reaching higher temperatures and producing a greater volume of hot water in simultaneous operation. The results show that the geometry of the absorber significantly influenced the performance of the system; the C2 configuration achieved higher water outlet temperatures (65.04–82.58 °C) compared to C1 (62.88–73.89 °C), in addition to producing a higher volume of hot water, with an average of 86.24 L/day versus 63.73 L/day, respectively, representing an increase of approximately 35%. Likewise, C2 presented greater thermal efficiency, reaching a maximum of 44.12%, while C1 registered maximum values of 26.60%. Consistently, the exergy analysis showed a better performance of C2, with exergy efficiencies of up to 3.78%, higher than those obtained by C1 (2.02%). These findings show that the increase in the effective heat transfer area and the greater thermal interaction between the absorber and the fluid, in C2, favor the performance of the collector, constituting an effective strategy to increase the production of hot water in parabolic trough solar collectors, especially in semi-industrial applications with high thermal demand.

Instituciones: Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas