Heat transfer to supercritical water flowing in short vertical bare tube and rod-bundle geometries

Water-cooled nuclear reactors have lower thermal efficiencies (26–38%) compared to thermal Power Pants (PPs) (up to 62%). To improve efficiency, SuperCritical Water-cooled Reactors (SCWRs) and SuperCritical-Pressure-Small Modular Reactors (SCP-SMRs) operate at supercritical pressures, requiring detailed studies of Heat Transfer (HT). This research investigates experimental data from vertical bare tubes and rod-bundle geometries (single-rod annular channel and 3-rod bundles with helical ribs) at pressures of 22.6–27.5 MPa, mass fluxes of 248–2700 kg/m²s, and Heat Fluxes (HFs) of 103–3289 kW/m². All three heat transfer regimes (Normal, Improved and Deteriorated) were observed, with stable behavior under unchanged conditions. Helical ribs had minimal impact on Heat Transfer Coefficients (HTCs) but increased the minimum HF for Deteriorated Heat Transfer Regime (DHT) onset by 1.6–1.8 times compared to bare tubes, offering critical insights for SCWR designs.

Name thesis:degree_name

Master of Applied Science (MASc)

Discipline thesis:degree_discipline

Nuclear Engineering

Grantor

University of Ontario Institute of Technology

Year dc:date.issued

2024

Author dc:creator

• Kavalci, Mehmet E.

Advisor dc:contributor.advisor

• Pioro, Igor

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10155/1896

OAI identifier oai:identifier

oai:ontariotechu.scholaris.ca:10155/1896