A population balance approach considering heat and mass transfer—Experiments and CFD simulations

This paper presents the results from computational fluid dynamics (CFD) simulations of heat and mass transfer of pure vapor flowing and condensing in a vertical cylindrical condenser system at various inlet temperatures, mass flow rates, and operating pressure for the case where the vapor condensation is not completed inside the condenser tube. The heat and mass transfer inside the condenser tube is simulated as single phase flow, and the thin condensate film on the condensing surface is replaced by a set of boundary conditions that couple the CFD simulations inside the condenser tube and the coolant channel. The CFD results are compared with the experimental results, and good agreement has been found for the various measured temperatures. It is found that both the wall temperature and the heat flux vary significantly along the condenser tube, and it is necessary to consider the conjugate problem that consists of the whole condenser system (condenser plus coolant flow) in predicting the pure vapor condensation in a condensing system. The CFD results show that the heat flux along the condenser tube can be increasing for counter-flow condenser, and the condensate film may not be the main limiting factor in the pure vapor condensation. The results from the CFD simulations also show that the estimation of the interface shear stress cannot be based on the bulk velocity of the water vapor alone.

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Study of dynamic structure and heat and mass transfer of a vertical ceramic tiles dryer using CFD simulations

Heat and Mass Transfer ◽

10.1007/s00231-013-1244-6 ◽

2013 ◽

Vol 50 (2) ◽

pp. 235-251 ◽

Cited By ~ 2

Author(s):

Wassim Kriaa ◽

Salma Bejaoui ◽

Hatem Mhiri ◽

Georges Le Palec ◽

Philippe Bournot

Keyword(s):

Mass Transfer ◽

Heat And Mass Transfer ◽

Dynamic Structure ◽

Ceramic Tiles ◽

Cfd Simulations

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An overview of recent applications of computational modelling in neonatology

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2010.0052 ◽

2010 ◽

Vol 368 (1920) ◽

pp. 2817-2834 ◽

Cited By ~ 11

Author(s):

Luiz C. Wrobel ◽

Maciej K. Ginalski ◽

Andrzej J. Nowak ◽

Derek B. Ingham ◽

Anna M. Fic

Keyword(s):

Heat Transfer ◽

Fluid Dynamics ◽

Mass Transfer ◽

Heat And Mass Transfer ◽

Medical Devices ◽

Computational Modelling ◽

Cfd Simulations ◽

Computational Fluid Dynamics Cfd ◽

Transfer Problems ◽

Transfer Mechanisms

This paper reviews some of our recent applications of computational fluid dynamics (CFD) to model heat and mass transfer problems in neonatology and investigates the major heat and mass-transfer mechanisms taking place in medical devices, such as incubators, radiant warmers and oxygen hoods. It is shown that CFD simulations are very flexible tools that can take into account all modes of heat transfer in assisting neonatal care and improving the design of medical devices.

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Simulation of Heat and Mass Transfer Involving Vapor Condensation in the Presence of Non-Condensable Gases in Plane Channels

ASME/JSME 2011 8th Thermal Engineering Joint Conference ◽

10.1115/ajtec2011-44138 ◽

2011 ◽

Cited By ~ 3

Author(s):

Mohammad Saraireh ◽

Graham Thorpe ◽

Jun-De Li

Keyword(s):

Heat Transfer ◽

Mass Transfer ◽

Water Vapor ◽

Heat And Mass Transfer ◽

Cooling Water ◽

Vapor Condensation ◽

Transfer Coefficients ◽

Cfd Simulations ◽

Constant Wall Temperature ◽

Mass Fractions

Results from computational fluid dynamics (CFD) simulations of heat and mass transfer involving the condensation of vapor in the presence of non-condensable gases in plane channels are presented. The simulations were carried out using FLUENT®. Convective heat and mass transfer and vapor condensation at a constant wall temperature were first investigated with the aim of comparing the CFD results with well established correlations. CFD simulations of heat and mass transfer and water vapor condensation in the presence of non-condensable air were then carried out for constant heat transfer coefficients for the condensation wall and coolant with different mass fractions of water vapor and inlet velocities. The predictions obtained from this are compared with experimental data and reasonable agreement has been found for the condensation rates of water vapor and heat flux. Finally, the condensation of the water vapor was simulated in a heat exchanger including both the cooling water and vapor-air mixture channels separated by solid walls. This simulation is close to reality and no assumptions are required for the temperature or heat transfer coefficient at the condensing wall. The difficulties of simultaneously simulating a gas mixture and liquid flowing in separate channels using commercially available CFD software are discussed and strategies to overcome these difficulties are outlined. Preliminary results from this third simulation will also be presented and compared with available experimental results.

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