نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
In this study, the synergistic effects of a honeycomb porous structure (HPS) and stabilized boiling surfaces on the pool boiling heat transfer characteristics of SiO₂ nanofluid under reduced concentration conditions is experimentally investigated. Dissipation of high heat fluxes is a major challenge in thermal systems, as approaching the critical heat flux (CHF) can lead to thermal instability and equipment damage. Surface stability is also essential for long-term operation, since instability during successive boiling cycles increases surface superheat and reduces system reliability. In addition, low-concentration nanofluids are preferred in practical applications to minimize nanoparticle deposition. First, the boiling surface was stabilized using a 2 wt% nanofluid under successive and prolonged boiling cycles. Then, the concentration was reduced to 0.5 wt%, leading to the formation of new stabilized layers on the initial surface. This approach preserves thermal performance while reducing deposition. After that, a HPS was attached to the stabilized surface. This structure increases the effective heat transfer area, enhances capillary liquid supply, and facilitates vapor removal. The results show that surface stability is maintained despite the reduced concentration. The combination with the porous structure improves thermal performance. Specifically, CHF increases by 35.6% and 39.8%, and the boiling heat transfer coefficient (BHTC) increases by 27.9% and 25.3%, compared to the stabilized surface without porous structure, for nanofluids with nanoparticle sizes of 20-30 and 60-70 nm, respectively. In addition, the porous structure increases the surface superheat at the onset of nucleate boiling (ONB).
کلیدواژهها English