Natural convection heat and moisture transfer with thermal radiation in a cavity partially filled with hygroscopic porous medium

2015 ◽  
Vol 34 (3) ◽  
pp. 275-286 ◽  
Author(s):  
Y. C. Wang ◽  
K. M. Yang ◽  
Z. T. Zhang ◽  
W. Qi ◽  
J. Yang
Keyword(s):  
Porous Medium ◽  
Natural Convection ◽  
Thermal Radiation ◽  
Moisture Transfer ◽  
Convection Heat ◽  
Heat And Moisture Transfer ◽  
Heat And Moisture

Experimental study of heat and moisture transfer in vertical air gap under protective clothing against dry and wet heat exposures

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yun Su ◽  
Miao Tian ◽  
Yunyi Wang ◽  
Xianghui Zhang ◽  
Jun Li
Keyword(s):  
Natural Convection ◽  
Protective Clothing ◽  
Moisture Transfer ◽  
Heat Exposure ◽  
Air Gap ◽  
Gap Size ◽  
Heat And Moisture Transfer ◽  
Content Type ◽  
Wet Heat ◽  
Heat And Moisture

PurposeThe purpose of this paper is to study heat and steam transfer in a vertical air gap and improve thermal protective performance of protective clothing under thermal radiation and hot steam.Design/methodology/approachAn experiment-based model was introduced to analyze heat and moisture transfer in the vertical air gap between the protective clothing and human body. A developed test apparatus was used to simulate different air gap sizes (3, 6, 9, 12, 15, 18, 21 and 24 mm). The protective clothing with different air gap sizes was subjected to dry and wet heat exposures.FindingsThe increase of the air gap size reduced the heat and moisture transfer from the protective clothing to the skin surface under both heat exposures. The minimum air gap size for the initiation of natural convection in the dry heat exposure was between 6 and 9 mm, while the air gap size for the occurrence of natural convection was increased in the wet heat exposure. In addition, the steam mass flux presented a sharp decrease with the rising of the air gap size, followed by a stable state, mainly depending on the molecular diffusion and the convection mass transfer.Originality/valueThis research provides a better understanding of the optimum air gap under the protective clothing, which contributes to the design of optimum air gap size that provided higher thermal protection against dry and wet heat exposures.

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