scholarly journals On the importance of heat and mass transfer coupling during characterization of hygroscopic insulation materials

2018 ◽  
Author(s):  
Patrick Perre ◽  
Arnaud Challansonnex
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Transient State ◽  
High Mass ◽  
Mass Diffusivity ◽  
Back Face ◽  
Materials Used ◽  
Set Up ◽  
Very High

The present work is focused on mass transfer characterization of hygroscopic materials used for insulation, such as Low Density Fibreboards. Due to their particular morphology, these panels present a very high mass diffusivity in the connected gaseous phase and a very low thermal conductivity. This combination of properties exacerbates the coupling between heat and mass transfer in transient state. Based on experimental data obtained with an original set-up and relevant simulations performed using a comprehensive physical formulation, a throughout vision of this question is proposed in the present study. In particular, we emphasize on: - The impressive change in core temperature in terms of magnitude and duration, - The great impact of the internal temperature gradient, which slows down mass diffusion, - The dramatic error on mass diffusivity value if the coupling is ignored. Keywords: experiment; identification; modelling; RH at back-face; transient state

Numerical Analysis of Heat and Mass Transfer Performance of the Packed-Type Parallel Flow Dehumidifier

2014 ◽  
Vol 989-994 ◽  
pp. 3100-3104
Author(s):  
Rui Hang Zhang ◽  
Zi Ye Wang ◽  
Run Ping Niu
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Parallel Flow ◽  
Transfer Performance ◽  
Transfer Coefficients ◽  
Simulation Results ◽  
Set Up ◽  
The Impact ◽  
The Mathematical Model

TA mathematical model describing heat and mass transfer performance of packed-type parallel flow dehumidifier was set up. The numerical solution of differential equations was derived. Taking the heat and mass transfer coefficients obtained by experiments as the input parameters of the model, the impact of solution inlet parameters on outlet parameter of air was described. The simulation results indicated that the mathematical model could be used to predict the performance of liquid dehumidification. The results showed that the mathematical model can be of great value in the design and improvement of dehumidifier.

Changed Heat and Mass Transfer Evaluation of a Gas-to-Gas Type Membrane Humidifier by Mass Collection

2010 ◽  
Author(s):  
ByungJun Kim ◽  
SangSeok Yu ◽  
YoungDuk Lee ◽  
KookYoung Ahn
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Steady State ◽  
Heat And Mass Transfer ◽  
Humidity Sensor ◽  
Transient State ◽  
Air Flow Rate ◽  
Dry Air ◽  
Mass And Heat Transfer ◽  
Mass Collection

In this paper, a technique of the humidity measurement is developed to identify the performance of membrane humidifier. The technique is designed to measure the performance of membrane humidifier during steady state and transient state. In particular, the measurement technique is very useful to understand dynamic behavior of humidifier because the response of commercial humidity sensor is too slow to capture the transient response of mass and heat transfer through the membrane. Accordingly, the heat and mass transfer characteristics of membrane humidifier are figured out with the experimental analysis. The parameters used in experiment are dry air pressure, humid air temperature and dry air flow rate.

scholarly journals Freeze-drying in protective bags: Characterization of heat and mass transfer

2020 ◽  
Vol 154 ◽  
pp. 309-316
Author(s):  
Rebecca Chamberlain ◽  
Jonas Schlauersbach ◽  
Matthias Erber
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Freeze Drying

Heat and mass transfer characterization of porous copper fiber sintered felt as catalyst support for methanol steam reforming

Fuel ◽  
2015 ◽  
Vol 145 ◽  
pp. 136-142 ◽  
Author(s):  
Wei Zhou ◽  
Qinghui Wang ◽  
Qingfu Qiu ◽  
Yong Tang ◽  
Jiawei Tu ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Steam Reforming ◽  
Catalyst Support ◽  
Methanol Steam Reforming ◽  
Porous Copper

Characterization of heat and mass transfer during deep-fat frying and its effect on cassava chip quality

2002 ◽  
Vol 53 (2) ◽  
pp. 161-176 ◽  
Author(s):  
Olivier Vitrac ◽  
Dominique Dufour ◽  
Gilles Trystram ◽  
Anne-Lucie Raoult-Wack
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Deep Fat Frying ◽  
Chip Quality

scholarly journals Influence of Turbulence, Density, Phase Change, and Phase Interfaces Models on the Performance of the Numerical Simulation of a Two-Phase Closed Thermosyphon

TecnoLógicas ◽  
2020 ◽  
Vol 23 (49) ◽  
pp. 53-70
Author(s):  
David Gamboa ◽  
Bernardo Herrera
Keyword(s):  
Mass Transfer ◽  
Phase Change ◽  
Heat And Mass Transfer ◽  
Saturation Temperature ◽  
Heat Pipes ◽  
Nucleate Boiling ◽  
High Energy ◽  
High Mass ◽  
Detailed Knowledge ◽  
Good Representation

A heat pipe can be considered a highly effective thermal conduction device, which is especially desirable in heat transfer operations in order to ensure high energy efficiency. However, the operation of heat pipes comprises different heat and mass transfer phenomena, such phase change, heat conduction and convection, solid-liquid and vapor-liquid surface interactions, surface vaporization, and nucleate boiling. Therefore, modelling heat pipes is a highly complex task that demands detailed knowledge of the physical phenomena involved and choosing suitable theoretical models to obtain a good representation of the real nature of the heat and mass transfer processes. In this study, some models and parameters available in the commercial CFD software ANSYS Fluent for turbulence, density, phase change, and phase interfaces were examined to determine their influence on the prediction of the heat and mass transfer in a two-phased closed thermosyphon (TPCT). The numerical results show that using a turbulence viscous model is not necessary and that a variable density model improves the temperature distribution inside the TPCT. Furthermore, using high mass and energy transfer coefficients during condensation makes the vapor remain close to the saturation temperature. Finally, a sharp interphase model is strongly recommended for this type of process.

scholarly journals RESEARCH FOR THE ESTABLISHMENT AND SOLUTION MATHEMATICAL MODEL OF HEAT AND MASS TRANSFER AT THE SAME TIME IN PROCESSING FREEZE - DRYING

2009 ◽  
Vol 12 (8) ◽  
pp. 67-80
Author(s):  
Dung Tan Nguyen ◽  
Dung Van Trinh ◽  
Bao Duc Tran
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Freeze Drying ◽  
Penaeus Monodon ◽  
Penaeus Vannamei ◽  
Applied Technology ◽  
Set Up ◽  
Penaeus Merguiensis

When applied technology Freeze - Drying in preserving foods had economy value, it seems that establishment and solution mathematical model heat and mass transfer at the same time in conditional processing freeze - drying is very important problem. From that point it is basis of science to determine regime technology Freeze - Drying. In this article, we will publish result research to set up and solve mathematical model heat and mass transfer at the same time of cylinder form in conditional freeze - drying. Result research will apply for preserving fishery foods crustacean group (PENAEUS MONODON, PENAEUS MERGUIENSIS, PENAEUS VANNAMEI) has economy value.

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