Comparison of Experimental Heat Transfer Coefficient with Qualitative Description of Classical Heat Transfer Coefficient at Low Heat Flux Conditions

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F46747885%3A24210%2F22%3A00010122" target="_blank" >RIV/46747885:24210/22:00010122 - isvavai.cz</a>

Result on the web

<a href="http://https:/10.11159/ffhmt22.185" target="_blank" >http://https:/10.11159/ffhmt22.185</a>

DOI - Digital Object Identifier

—

Result language

angličtina

Original language name

Comparison of Experimental Heat Transfer Coefficient with Qualitative Description of Classical Heat Transfer Coefficient at Low Heat Flux Conditions

Original language description

Due to complexities involved in experimental determination of heat transfer coefficient, diverse qualitative flow descriptions and maps have been proposed as the basis for theories and correlations. Interestingly, there have been several disagreements with the different qualitative descriptions and maps on their actual representation of heat transfer coefficient for certain regions of flow boiling processes. This study therefore seeks to experimentally investigate and compare the characteristics of heat transfer coefficient at low heat flux conditions with qualitative descriptions of heat transfer coefficient by different authors. In this study, R134a was the refrigerant used, heat fluxes from 4.6-8.5 kW/m2 and mass flux of 200-300 kg/m2s. The experimental heat transfer coefficient results were compared with Wojtan et al flow patterns map. In covering heat transfer coefficient over a wide range of vapor qualities, it was observed that, the qualitative descriptions proposed by different authors do not entirely validate the actual representation of heat transfer process within the experimental conditions studied. At vapor quality around zero (0), heat transfer coefficient rises to a peak and decreases to a local minimum before increasing as vapor quality increases and the flow pattern predicted for this region is slug flow. As vapor quality increased, the flow patterns observed were intermittent, annular, dryout and mist flow

Czech name

—

Czech description

—

Type

A - Audiovisual production

CEP classification

—

OECD FORD branch

20301 - Mechanical engineering

Project

—

Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

ISBN

—

Place of publication

—

Publisher/client name

—

Version

—

Carrier ID

—