Investigation Of Convective Heat Transfer In A Cold Flow Pebble Bed Nuclear Reactor Using Advanced Pebble Probe Heat Transfer Sensor
Abstract
The aim of this study was to investigate the local heat transfer coefficients between the pebbles and the coolant gas in a PBR using an advanced measurement technique that consists of a heated pebble probe, a micro-foil heat flux sensor mounted flush on the surface of the heated pebble probe, and a thermocouple in the center of the bed void in front the sensor. In this work, the local heat transfer coefficients were derived at various axial levels, radial and angular locations and at different superficial inlet gas velocities that cover both transitional and turbulent flow conditions. The local heat transfer coefficients were found to be 22-32%, 34-39%, and 18-20% higher near the wall at superficial inlet gas velocities of 0.3,1.2, and 2m/s, respectively. This is due to higher volumetric flow at the wall where larger void in the pebble bed exists compared to the center region of the bed where the flow of the gas in the packed bed follows the least resistance path. Large deviations were obtained between the experimental overall heat transfer coefficients in the bed and the predictions of seven correlations that were selected from the literature. Furthermore, these correlations cannot predict the local heat transfer coefficients inside the PBR. This necessitates the development of new correlations for the prediction of the local heat transfer coefficients using the data obtained in this work. A pseudo-3D correlation was developed and was found to provide predictions that are in good agreement with the experimental values for the conditions used, with an averaged absolute relative error (AARE) of 3.33% at high Reynolds numbers for our operating and design conditions.
Recommended Citation
M. Alshammari et al., "Investigation Of Convective Heat Transfer In A Cold Flow Pebble Bed Nuclear Reactor Using Advanced Pebble Probe Heat Transfer Sensor," Experimental Thermal and Fluid Science, vol. 154, article no. 111148, Elsevier, May 2024.
The definitive version is available at https://doi.org/10.1016/j.expthermflusci.2024.111148
Department(s)
Chemical and Biochemical Engineering
Keywords and Phrases
Heat transfer pebble probe; High Temperature Gas-Cooled Reactor; Local heat transfer coefficient; Pebble bed
International Standard Serial Number (ISSN)
0894-1777
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 Elsevier, All rights reserved.
Publication Date
01 May 2024
