Experimental Study of Flow Boiling Heat Transfer at Low Heat Fluxes

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F46747885%3A24210%2F22%3A00010120" target="_blank" >RIV/46747885:24210/22:00010120 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/46747885:24210/22:00010124

Výsledek na webu

<a href="https://10.11159/jffhmt.2022.018" target="_blank" >https://10.11159/jffhmt.2022.018</a>

DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Experimental Study of Flow Boiling Heat Transfer at Low Heat Fluxes

Popis výsledku v původním jazyce

This study presents an experimental investigation of heat transfer characteristics at low heat flux conditions. The focus is to compare experimental findings with qualitative descriptions of heat transfer coefficient reported in literature. The study also compares the experimental results with 3 correlations developed based on different theories. For the experimental conditions, R134a was the refrigerant used, heat fluxes ranged from 4.6-8.5 kW/m2 and mass flux from 200-300 kg/m2s. The experimental heat transfer coefficient results were also compared with Wojtan et al flow patterns map to determine the flow patterns observed during the study. In covering heat transfer coefficient over a broad range of vapor qualities, the findings revealed that, the qualitative descriptions proposed by different authors do not entirely validate the actual representation of heat transfer coefficient within the experimental conditions considered. At vapor qualities around zero (0), heat transfer coefficient rises to a maximum peak and decreases to a local minimum before increasing as vapor quality increases until it reaches dry-out. The flow pattern predicted are slug flow at low vapor-quality region, intermittent flow at mid vapor quality region and annular, dry-out and mist flow at high vapor quality region. None of the flow boiling correlations considered in this study was able to accurately predict the heat transfer data within a mean absolute error (MAE) of ± 30%

Název v anglickém jazyce

Experimental Study of Flow Boiling Heat Transfer at Low Heat Fluxes

Popis výsledku anglicky

This study presents an experimental investigation of heat transfer characteristics at low heat flux conditions. The focus is to compare experimental findings with qualitative descriptions of heat transfer coefficient reported in literature. The study also compares the experimental results with 3 correlations developed based on different theories. For the experimental conditions, R134a was the refrigerant used, heat fluxes ranged from 4.6-8.5 kW/m2 and mass flux from 200-300 kg/m2s. The experimental heat transfer coefficient results were also compared with Wojtan et al flow patterns map to determine the flow patterns observed during the study. In covering heat transfer coefficient over a broad range of vapor qualities, the findings revealed that, the qualitative descriptions proposed by different authors do not entirely validate the actual representation of heat transfer coefficient within the experimental conditions considered. At vapor qualities around zero (0), heat transfer coefficient rises to a maximum peak and decreases to a local minimum before increasing as vapor quality increases until it reaches dry-out. The flow pattern predicted are slug flow at low vapor-quality region, intermittent flow at mid vapor quality region and annular, dry-out and mist flow at high vapor quality region. None of the flow boiling correlations considered in this study was able to accurately predict the heat transfer data within a mean absolute error (MAE) of ± 30%

Druh

O - Ostatní výsledky

CEP obor

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OECD FORD obor

20301 - Mechanical engineering

Projekt

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Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2022

Kód důvěrnosti údajů

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