Simultaneous heat and mass transfer in free convection

Simultaneous mass and heat transfer with reactions in a multicomponent, laminar, falling liquid film

Simultaneous free-convection heat and mass transfer in laminar boundary layers

Laminar film condensation of gravity-controlled convection for ternary vapor mixtures is theoretically treated. Similarity solutions for methanol-ethanol-water mixtures on an isothermal vertical flat plate are numerically obtained. The effects of mutual intervention of buoyant forces due to temperature and concentration differences on convective heat and mass transfer in the vapor boundary layer are revealed. The dimensionless expressions for heat and mass-transfer coefficients are derived from the numerical results. These expressions approach the characteristics of simultaneous heat and mass transfer in free convection of ternary vapor mixtures with the decrease in condensate mass flux. Heat and mass-transfer characteristics are calculated from the simultaneous algebraic equations which are composed of these expressions, phase equilibrium conditions and the continuity conditions of heat flux and mass transfer at a vapor-liquid interface.

Uni-directional heat and mass transfer at high humidities in a wetted wall column

Field synergy principle of heat and mass transfer

Modeling of simultaneous heat and mass transfer during convective oven ring cake baking

Simultaneous heat and mass transfer characteristics for wavy fin-and-tube heat exchangers under dehumidifying conditions

Chapter 7 - Heat and Mass Transfer

In order to investigate how simultaneous heat and mass transfer by free convection interact, some numerical theoretical results are presented and discussed. The total flow rate appears to be an essential element in obtaining some insight into this interaction.

Modeling of chemical reactors — XXII Effect of simultaneous heat and mass transfer inside and outside of a pellet on reaction rate — II

Simultaneous convective heat and mass transfer in impingement ink drying

Drying agricultural products and other porous media is typically done in the open sun, which is unhygienic, labour intensive, and dependent on varying weather conditions. Designing an efficient drying system requires a comprehensive computational analysis of relevant drying phenomena. In this study, numerical simulations and experimental investigations of three-dimensional simultaneous heat and mass transfer in a photovoltaic (PV) - powered drying system operating under forced convection were conducted under no load conditions. The equations governing continuity, momentum, energy, and species were solved using ANSYS Fluent’s Finite Volume Method (FVM), a computational fluid dynamics tool. The highest simulated temperature and velocity in the drying chamber, 393 K and 1.55 m/s, respectively, closely matched the experimental values of 386 K and 1.40 m/s. It is recommended that the developed drying system serve as a practical alternative to traditional open sun drying, as the numerical results were within an acceptable range.

Recently, study on a microscale-based absorption refrigeration system has sprung up motivated by the need of efficient energy utilization. Heat-driven absorption systems offer a possibility of generating both power and cooling with environment friendly refrigerants, such as ammonia/water and LiBr/water. However, these systems are often large in size and low in COP especially in single stage absorption systems. These characteristics of absorptions systems make them unattractive in most cases. This work introduces the utilization of micro-channel enhanced surfaces as heat exchangers to enhance the component and system performance, to reduce the system size and to reduce the cost of the system as well. In this work, a new concept of enhancing heat and mass transfer processes is applied in the absorber part of the absorption cycle by using a single micro-channel. Due to its merit of high area to volume ratio, microchannel technology has been well theoretically validated to be a very effective and potential choice for enhancing heat transfer performance. But there is a lack of research work on the mass transfer performance in micro-channels. This work investigated simultaneous mass and heat transfer characteristics of a novel microchannel absorber that uses LiBr/water as the working fluid. A microchannel with hydraulic diameter of 0.7mm is employed in this characterization study. Velocity distribution, pressure drop, concentration and temperature profile inside the microchannel as well as effects of the inlet absorbent concentration, flow rate and temperature together with the refrigerant flow rate on the heat/mass transfer are predicted. Investigations on the optimum inlet angle design of a single channel absorber are also presented in the end of this work. Feasibility of this novel absorber design was proved via this numerical simulation as the mass transfer taking place inside the mixing channel was observed to achieve the identical performance but with a size reduction by 1/27 compared to a conventional falling film absorber. A 7 times enhancement of the heat transfer coefficient was also achieved with the comparison of a macro-scale based absorber configuration.

The graphical determination of changes in the gas phase due to simultaneous heat and mass transfer

Simultaneous heat and mass transfer in laminar falling film on the outside of a circular tube