View in EDS

Development and feasibility demonstration of a capacitance-based sensor for liquid film thickness measurement on a heated rod surface under falling-film conditions.

Saved in:
Bibliographic Details
Title: Development and feasibility demonstration of a capacitance-based sensor for liquid film thickness measurement on a heated rod surface under falling-film conditions.
Authors: Ueda, S.1 (AUTHOR) ueda3745@criepi.denken.or.jp, Arai, T.1 (AUTHOR) t-arai@criepi.denken.or.jp, Furuya, M.1 (AUTHOR) furuya@criepi.denken.or.jp
Source: Nuclear Engineering & Design. Sep2026, Vol. 456, pN.PAG-N.PAG. 1p.
Subjects: Capacitive sensors, Film flow, Nucleate boiling, Heat transfer, Nuclear fuels, Nuclear fuel rods
Abstract: The distribution of liquid film thickness on heat transfer surfaces in fuel assemblies of light water reactors is a critical factor in heat transfer performance. Therefore, developing sensors capable of multipoint measurements in such complex flow paths is essential. A capacitance-based liquid film sensor was designed to measure the liquid film thickness in boiling flow within a rod bundle simulating a nuclear fuel assembly, without disturbing the liquid film. The proposed method evaluates liquid film thickness by measuring capacitance between a rod electrode, simulating a fuel rod in the rod bundle flow path, and a wire strung inside the flow path as a measurement electrode. The key innovation of this study lies in applying the capacitance-based measurement concept to a rod bundle geometry. A demonstrative experiment was conducted in an air-water falling liquid film flow, comparing results from the developed sensor with those from a laser focus displacement meter. To facilitate future integration into a rod bundle, a part of the sensor was fabricated using a single rod and wire electrode, and its operating principle and performance were examined. Furthermore, liquid film thicknesses on both unheated and heated rods were measured under identical flow conditions, demonstrating that the developed sensor is also capable of measuring liquid film thickness on a heated rod. • A capacitance-based sensor measures the liquid film thickness on a heated heater rod surface. • The sensor enables non-intrusive, multipoint film measurement in complex high-temperature, high-pressure rod bundles. • Experimental validation shows consistency with laser focus displacement meter data. • The sensor accurately measures liquid film thickness on both heated and unheated rods. • Findings expand multidimensional measurement options in simulated nuclear fuel assemblies and thermal-hydraulic tests. [ABSTRACT FROM AUTHOR]
Copyright of Nuclear Engineering & Design is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:The distribution of liquid film thickness on heat transfer surfaces in fuel assemblies of light water reactors is a critical factor in heat transfer performance. Therefore, developing sensors capable of multipoint measurements in such complex flow paths is essential. A capacitance-based liquid film sensor was designed to measure the liquid film thickness in boiling flow within a rod bundle simulating a nuclear fuel assembly, without disturbing the liquid film. The proposed method evaluates liquid film thickness by measuring capacitance between a rod electrode, simulating a fuel rod in the rod bundle flow path, and a wire strung inside the flow path as a measurement electrode. The key innovation of this study lies in applying the capacitance-based measurement concept to a rod bundle geometry. A demonstrative experiment was conducted in an air-water falling liquid film flow, comparing results from the developed sensor with those from a laser focus displacement meter. To facilitate future integration into a rod bundle, a part of the sensor was fabricated using a single rod and wire electrode, and its operating principle and performance were examined. Furthermore, liquid film thicknesses on both unheated and heated rods were measured under identical flow conditions, demonstrating that the developed sensor is also capable of measuring liquid film thickness on a heated rod. • A capacitance-based sensor measures the liquid film thickness on a heated heater rod surface. • The sensor enables non-intrusive, multipoint film measurement in complex high-temperature, high-pressure rod bundles. • Experimental validation shows consistency with laser focus displacement meter data. • The sensor accurately measures liquid film thickness on both heated and unheated rods. • Findings expand multidimensional measurement options in simulated nuclear fuel assemblies and thermal-hydraulic tests. [ABSTRACT FROM AUTHOR]
ISSN:00295493
DOI:10.1016/j.nucengdes.2026.115021