scholarly journals Modern approaches to the intensification of heat and mass exchange in multi-temperature condensation filters

2021 ◽  
Vol 2039 (1) ◽  
pp. 012018
Author(s):  
M V Malevany ◽  
D A Konovalov
Keyword(s):  
Mass Transfer ◽  
Heat Exchange ◽  
Heat And Mass Transfer ◽  
Liquid Flow ◽  
Mass Exchange ◽  
Single Phase ◽  
Heat And Mass Exchange ◽  
Analytical Review

Abstract The article considers the problems and features of heat and mass exchange on developed surfaces in the conditions of both single-phase and vapour-liquid flow during its condensation. We give a brief analytical review of studies of hydrodynamics and heat exchange in such systems. We analyzed the efficiency of the working channel of the condensation filter and identified problematic points. We offer possible methods for intensifying heat and mass transfer on working surfaces.

Comparative Heat and Mass Transfer Tests of Structured Packings with Film and Droplet Flow

2019 ◽  
pp. 4-21
Author(s):  
E.K. Aliev ◽  
V.V. Volodin ◽  
V.V. Golub ◽  
A.Yu. Mikushkin ◽  
G.G. Timerbaev ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Mass Exchange ◽  
Gas Flow ◽  
Packed Bed ◽  
Hydraulic Characteristics ◽  
Heat And Mass Exchange ◽  
Contact Devices ◽  
Structured Packings ◽  
Gas Volume

The paper focuses on comparative studies of heat and mass transfer and hydraulic characteristics of two structured packings which provide heat and mass transfer of contacting media in the film flow of liquid Mellapak 250.X and with fluid dispersion in the gas volume PVN.22. The experiments were carried out in a heat-mass exchange column of 400 mm in diameter and of 1 m in height of a packed bed. The method of evaporative cooling of water in the air flow was adapted to obtain heat and mass exchange characteristics of packed contact devices. Findings of research show the effect of irrigation density and gas flow on heat and mass transfer and hydraulic characteristics of packings which provide heat and mass transfer of contacting media in film and droplet flows. A criterion for estimating the efficiency of contact devices is proposed.

scholarly journals Modelling thermomechanical properties of the snowpack

2000 ◽  
Vol 31 ◽  
pp. 451-456
Author(s):  
Elena Guseva-Lozinski
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Structural Parameters ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Thermomechanical Properties ◽  
Frozen Soil ◽  
Structural Variations ◽  
Heat And Mass Exchange ◽  
Snow Properties

AbstractStudying the structure inside an inhomogeneous stratified snowpack is very important for modelling of the snowpack stability on mountain slopes, and to approximate surfaces of weak zones, and boundaries with different properties These surfaces are often the sliding surfaces of avalanches. Weather conditions" windpumping, snow densification and mechanical and complex heat- and mass-transfer processes define the structural variations of snow and the strength characteristics. The main ventilation components in the snowpack during the snowstorm are the heat and mass exchange between the snow grains and bonds, vapor and heat transfer. The vapor diffusion due to windpumping through snowpack intensifies the metamorphic process We propose the current mathematical model using meteorological data to simulate the snowpack characteristics in order to clarify the changes of the structural and physical-mechanical properties in the stratified snowpack under changing weather conditions. The system of equations allows calculation of the temperature variation in the snowpack, as well as in melted or frozen soil, the snow density, the structural parameters and the snowpack strength on the mountain slope as a function of the heat- and mass-transfer parameters. A numerical finite-difference model for simulations has been used. This allows prediction of the disposition of the depth-hoar layers and the physical-mechanical snow properties. The model has potential to estimate the potential avalanche volume.

scholarly journals The Implicit Keller Box Scheme for Combined Heat and Mass Transfer of Brinkman-Type Micropolar Nanofluid with Brownian Motion and Thermophoretic Effect Over an Inclined Surface

2019 ◽  
Vol 10 (1) ◽  
pp. 280 ◽  
Author(s):  
Khuram Rafique ◽  
Muhammad Imran Anwar ◽  
Masnita Misiran ◽  
Ilyas Khan ◽  
El-Sayed M. Sherif
Keyword(s):  
Mass Transfer ◽  
Brownian Motion ◽  
Differential Equations ◽  
Numerical Solution ◽  
Heat And Mass Transfer ◽  
Nonlinear Partial Differential Equations ◽  
Heat And Mass Exchange ◽  
Micropolar Nanofluid ◽  
Efficient Scheme ◽  
Mass Flow Rates

The main purpose of the present analysis is to report the numerical solution of the thermal radiations and magnetohydrodynamic (MHD) effect on the flow of micropolar nanofluid. Further, the effect of Brownian motion and thermophoresis on the flow field are also elucidated. The combined phenomenon of heat and mass transfer is considered. Compatible similarities are implemented for the conversion of nonlinear ordinary differential equations from nonlinear partial differential equations. The numerical solution of the governing differential equations is obtained via the implicit Keller box technique. This is an efficient scheme based on the finite difference method. Findings demonstrate that the heat and mass exchange reduce with growth of the Brinkman parameter, whereas the wall shear stress enhances with improving the magnitude of the Brinkman factor. The temperature contour enhances when the radiation parameter reaches its peak, which is useful for industrial processes. The heat and mass flow rates decrease against higher magnitudes of inclination.

scholarly journals Experimental assessment of heat and mass transfer characteristics of solar-powered adiabatic liquid desiccant dehumidifier and regenerator

2020 ◽  
Vol 15 (4) ◽  
pp. 477-495
Author(s):  
Andrew Y A Oyieke ◽  
Freddie L Inambao
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Removal Rate ◽  
Lewis Number ◽  
Constant Thickness ◽  
Liquid Desiccant ◽  
Transfer Coefficients ◽  
Heat And Mass Exchange ◽  
Flow Rates ◽  
Solar Powered

Abstract Coupled heat and mass transfer performance of an adiabatic solar-powered liquid desiccant dehumidification and regeneration scheme using lithium bromide(LiBr) solution has been conducted experimentally as well as numerically under subtropical climatic conditions. The application of a vacuum insulated photovoltaic and thermal module to provide desiccant regeneration heat as well as electrical power to drive the air fans and liquid pumps have been explored. A square channelled ceramic cordierite packing with a varying channel density of 20–80 m$^2$/m$^3$ has been used to establish the optimum direct air-LiBr contact ratio for maximum effectiveness. The aggregate crammed vertical dehumidifier and regenerator operational indices featured were effectiveness, moisture removal rate (MRR), heat and mass transfer constants and Lewis number. The influence of solar radiation, humidity and L/G ratios, air–desiccant flow rates and concentration on the indices have been scrutinized in details. A 3D predictive numerical thermal model based on falling liquid stream with constant thickness in counter-flow configuration has been developed and solved by a combination of separative appraisal and stepwise iterative technique. The heat and mass exchange coefficients significantly increased with the increase in Lewis number, air and desiccant flow rates for both the dehumidifier and regenerator vessels. The predicted results of heat and mass transfer coefficients, effectiveness and MRRs have been validated with experimental measurements within a general acceptable conformity of less than $\pm $10%.

The Environmental Mechanic (a tribute to J. R. Philip)

Soil Research ◽  
2001 ◽  
Vol 39 (4) ◽  
pp. 649 ◽  
Author(s):  
Frank Bradley ◽  
Brent Clothier ◽  
Tom Denmead ◽  
Dan de Vries ◽  
Phillip Ford ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Soil Water ◽  
Heat And Mass Transfer ◽  
Liquid Flow ◽  
Water Movement ◽  
Applied Mathematics ◽  
Complex Character ◽  
Complete Bibliography ◽  
Soil Water Movement

John Philip AO FRS FAA was killed by accident in Amsterdam in 1999. This tribute provides a complete bibliography and brings together perceptions of the work and of the complex character of the greatest of Australia�s environmental scientists. It deals with his contributions in general applied mathematics, in soil water movement, in liquid flow in swelling systems, in coupled heat and mass transfer, and in micrometeorology and physical ecology.

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