Avinash Jacob Balihar, Arnab Karmakar, Avinash Kumar, Smriti Minj, P L John Sangso
{"title":"Analysis of Thermal Performance in a Two-phase Thermosyphon loop based on Flow Visualization and an Image Processing Technique","authors":"Avinash Jacob Balihar, Arnab Karmakar, Avinash Kumar, Smriti Minj, P L John Sangso","doi":"10.1615/heattransres.2024052009","DOIUrl":null,"url":null,"abstract":"Thermal performance was analyzed based on flow visualization and an image processing technique in a two-phase thermosyphon loop (TPTL) with boiling water as the working fluid at low pressure. The bubble geometries, bubble frequency, and dynamic void fraction were measured using direct image analysis combined with the power spectrum and statistical analysis. At a heating rate of 400 W and a filling ratio of 0.88, the thermal performance of the TPTL was enhanced with a thermal efficiency of 91% and effective thermal conductivity of 43858.84 W m‒1 oC‒1. The enhancement was due to the higher frequency cap bubble flow of 11.2 Hz obtained by the direct flow visualization. The bigger Taylor bubbles with slug flow were examined to contribute to the negative effect on the heat transfer rate due to their film boiling regimes. The detailed analysis reveals the mechanism of bubble flow interacting with thermal performance.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":null,"pages":null},"PeriodicalIF":1.7000,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Heat Transfer Research","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1615/heattransres.2024052009","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"THERMODYNAMICS","Score":null,"Total":0}
引用次数: 0
Abstract
Thermal performance was analyzed based on flow visualization and an image processing technique in a two-phase thermosyphon loop (TPTL) with boiling water as the working fluid at low pressure. The bubble geometries, bubble frequency, and dynamic void fraction were measured using direct image analysis combined with the power spectrum and statistical analysis. At a heating rate of 400 W and a filling ratio of 0.88, the thermal performance of the TPTL was enhanced with a thermal efficiency of 91% and effective thermal conductivity of 43858.84 W m‒1 oC‒1. The enhancement was due to the higher frequency cap bubble flow of 11.2 Hz obtained by the direct flow visualization. The bigger Taylor bubbles with slug flow were examined to contribute to the negative effect on the heat transfer rate due to their film boiling regimes. The detailed analysis reveals the mechanism of bubble flow interacting with thermal performance.
期刊介绍:
Heat Transfer Research (ISSN1064-2285) presents archived theoretical, applied, and experimental papers selected globally. Selected papers from technical conference proceedings and academic laboratory reports are also published. Papers are selected and reviewed by a group of expert associate editors, guided by a distinguished advisory board, and represent the best of current work in the field. Heat Transfer Research is published under an exclusive license to Begell House, Inc., in full compliance with the International Copyright Convention. Subjects covered in Heat Transfer Research encompass the entire field of heat transfer and relevant areas of fluid dynamics, including conduction, convection and radiation, phase change phenomena including boiling and solidification, heat exchanger design and testing, heat transfer in nuclear reactors, mass transfer, geothermal heat recovery, multi-scale heat transfer, heat and mass transfer in alternative energy systems, and thermophysical properties of materials.