Unsteady phenomena in saturated flow boiling heat transfer – An experimental study on oscillating refrigerant mass flux

The present work pertains to experimental studies on the unsteady phenomena in the saturated flow boiling of R407C stemming from the oscillatory refrigerant flow rate with the triangle shape in the horizontal slender annular channel. Attention is mainly paid to examine the effects of different param...

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Autores principales:	Wen-Ken Li, Y.J. Wang, T.F. Lin, Bo-Lin Chen, C.A. Chen, Wei-Mon Yan
Formato:	article
Lenguaje:	EN
Publicado:	Elsevier 2022
Materias:	Saturated flow boiling Time alternating R407C Energy efficiency Oscillation in mass flux Engineering (General). Civil engineering (General) TA1-2040
Acceso en línea:	https://doaj.org/article/62ccc5a4f0da4c48b857cf4e80f315b1
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spelling	oai:doaj.org-article:62ccc5a4f0da4c48b857cf4e80f315b12021-12-02T04:59:37ZUnsteady phenomena in saturated flow boiling heat transfer – An experimental study on oscillating refrigerant mass flux1110-016810.1016/j.aej.2021.06.105https://doaj.org/article/62ccc5a4f0da4c48b857cf4e80f315b12022-03-01T00:00:00Zhttp://www.sciencedirect.com/science/article/pii/S1110016821004646https://doaj.org/toc/1110-0168The present work pertains to experimental studies on the unsteady phenomena in the saturated flow boiling of R407C stemming from the oscillatory refrigerant flow rate with the triangle shape in the horizontal slender annular channel. Attention is mainly paid to examine the effects of different parameters, including mean mass flux, amplitude and period of the oscillating mass flux, saturation temperature of R407C, input thermal flux, and gap size on the boiling diagrams and heat transfer coefficients. Firstly, the steady-state saturated flow boiling is studied as baseline cases. It was concluded that beyond the onset of nucleate boiling region, the mass flux of refrigerant has little influences on the boiling diagrams, which indicates that the fully developed nucleate boiling is the major mechanism. The saturated flow boiling heat transfer coefficient is enhanced as the gap size is reduced. Then, the experiment focuses on the temporal changes in the wall temperature Tw and the heat transfer coefficient hr stemming from oscillatory flow conditions. When the mass flux is oscillated periodically with the triangle shape, the Tw and hr are also oscillated temporally and enhanced with increasing in either the amplitude or frequency of oscillating mass flux. At higher input thermal flux, Tw decreases with the decreasing mass flux, which has opposite tendency compared to the single-phase convection with lower thermal flux. For intermediate exerted thermal flux, there is a negligible oscillation in the Tw and hr for most cases; the amplitudes of oscillations are lower than 0.2 °C. Besides, the significant oscillations in the wall temperature and heat transfer coefficient are noted the case with large period of the oscillating mass flux.Wen-Ken LiY.J. WangT.F. LinBo-Lin ChenC.A. ChenWei-Mon YanElsevierarticleSaturated flow boilingTime alternatingR407CEnergy efficiencyOscillation in mass fluxEngineering (General). Civil engineering (General)TA1-2040ENAlexandria Engineering Journal, Vol 61, Iss 3, Pp 2430-2442 (2022)
institution	DOAJ
collection	DOAJ
language	EN
topic	Saturated flow boiling Time alternating R407C Energy efficiency Oscillation in mass flux Engineering (General). Civil engineering (General) TA1-2040
spellingShingle	Saturated flow boiling Time alternating R407C Energy efficiency Oscillation in mass flux Engineering (General). Civil engineering (General) TA1-2040 Wen-Ken Li Y.J. Wang T.F. Lin Bo-Lin Chen C.A. Chen Wei-Mon Yan Unsteady phenomena in saturated flow boiling heat transfer – An experimental study on oscillating refrigerant mass flux
description	The present work pertains to experimental studies on the unsteady phenomena in the saturated flow boiling of R407C stemming from the oscillatory refrigerant flow rate with the triangle shape in the horizontal slender annular channel. Attention is mainly paid to examine the effects of different parameters, including mean mass flux, amplitude and period of the oscillating mass flux, saturation temperature of R407C, input thermal flux, and gap size on the boiling diagrams and heat transfer coefficients. Firstly, the steady-state saturated flow boiling is studied as baseline cases. It was concluded that beyond the onset of nucleate boiling region, the mass flux of refrigerant has little influences on the boiling diagrams, which indicates that the fully developed nucleate boiling is the major mechanism. The saturated flow boiling heat transfer coefficient is enhanced as the gap size is reduced. Then, the experiment focuses on the temporal changes in the wall temperature Tw and the heat transfer coefficient hr stemming from oscillatory flow conditions. When the mass flux is oscillated periodically with the triangle shape, the Tw and hr are also oscillated temporally and enhanced with increasing in either the amplitude or frequency of oscillating mass flux. At higher input thermal flux, Tw decreases with the decreasing mass flux, which has opposite tendency compared to the single-phase convection with lower thermal flux. For intermediate exerted thermal flux, there is a negligible oscillation in the Tw and hr for most cases; the amplitudes of oscillations are lower than 0.2 °C. Besides, the significant oscillations in the wall temperature and heat transfer coefficient are noted the case with large period of the oscillating mass flux.
format	article
author	Wen-Ken Li Y.J. Wang T.F. Lin Bo-Lin Chen C.A. Chen Wei-Mon Yan
author_facet	Wen-Ken Li Y.J. Wang T.F. Lin Bo-Lin Chen C.A. Chen Wei-Mon Yan
author_sort	Wen-Ken Li
title	Unsteady phenomena in saturated flow boiling heat transfer – An experimental study on oscillating refrigerant mass flux
title_short	Unsteady phenomena in saturated flow boiling heat transfer – An experimental study on oscillating refrigerant mass flux
title_full	Unsteady phenomena in saturated flow boiling heat transfer – An experimental study on oscillating refrigerant mass flux
title_fullStr	Unsteady phenomena in saturated flow boiling heat transfer – An experimental study on oscillating refrigerant mass flux
title_full_unstemmed	Unsteady phenomena in saturated flow boiling heat transfer – An experimental study on oscillating refrigerant mass flux
title_sort	unsteady phenomena in saturated flow boiling heat transfer – an experimental study on oscillating refrigerant mass flux
publisher	Elsevier
publishDate	2022
url	https://doaj.org/article/62ccc5a4f0da4c48b857cf4e80f315b1
work_keys_str_mv	AT wenkenli unsteadyphenomenainsaturatedflowboilingheattransferanexperimentalstudyonoscillatingrefrigerantmassflux AT yjwang unsteadyphenomenainsaturatedflowboilingheattransferanexperimentalstudyonoscillatingrefrigerantmassflux AT tflin unsteadyphenomenainsaturatedflowboilingheattransferanexperimentalstudyonoscillatingrefrigerantmassflux AT bolinchen unsteadyphenomenainsaturatedflowboilingheattransferanexperimentalstudyonoscillatingrefrigerantmassflux AT cachen unsteadyphenomenainsaturatedflowboilingheattransferanexperimentalstudyonoscillatingrefrigerantmassflux AT weimonyan unsteadyphenomenainsaturatedflowboilingheattransferanexperimentalstudyonoscillatingrefrigerantmassflux
_version_	1718400892478160896

Unsteady phenomena in saturated flow boiling heat transfer – An experimental study on oscillating refrigerant mass flux

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