CFD Simulations of Heat and Mass Transport in Multiphase Flows

Prof. Dr. Eugeny Kenig, Universität Paderborn

Foodstuff industry companies produce ice in form of ice shards directly at the manufacturing site in order to implement product cooling. Recently, a new ice machine design (compare with Figure 1) enabling more energy-efficient ice production has been proposed; it is characterized by lower operating and maintenance costs compared to conventional designs. The key components of the new machines are panels made of pillow-like plates, which are arranged as vertically aligned and parallel to each other. Water is supplied to the outer pillow-plate surface as a thin liquid film, while a working medium at a temperature below the water freezing point, is directed through the inner channels of the pillow-plate panels. As a result, water freezes on the outer panel surface due to the latent heat dissipation to the working medium flowing inside the pillow-plate panels. As soon as the desired thickness of the ice layer is reached, a warm working medium is guided through the inner channels so that the ice layer detaches from the pillow-plate surface, falls down and is processed into shards by a crusher.

Pillow-plate panels represent a quite new type of heat transfer equipment, and therefore, their thermo-hydraulic characteristics are still not fully captured. This is why appropriate design equations for the new ice machines are missing, resulting in certain design uncertainties preventing exploitation of their full potential. To overcome this problem, we have applied advanced numerical methods, the so-called Computational Fluid Dynamics, to study the film flow on the outer surface of the pillow-plate panels as well as the ice formation process. The simulations belong to the class of multiphase flow, which is very demanding and requires significant computational power. We executed our simulations with the aid of two commercial software tools, ANSYS Fluent and SIEMENS PLM Star-CCM+, in parallel on up to 1024 computational cores.

References

[1]  R.F. Engberg, M. Wegener, E.Y. Kenig
Numerische Simulation der konzentrationsinduzierten Marangoni-Konvektion an Einzeltropfen mit verformbarer Phasengrenze
Chem. Ing. Techn. 86, 185-195 (2014)

[2]  R.F. Engberg, M. Wegener, E.Y. Kenig
The impact of Marangoni convection on fluid dynamics and mass transfer at deformable single rising droplets - A numerical study
Chem. Eng. Sci. 116, 208-222 (2014)

[3]  R.F. Engberg, M. Wegener, E.Y. Kenig
The influence of Marangoni convection on fluid dynamics of oscillating single rising droplets
Chem. Eng. Sci. 117, 114-124 (2014)

[4]  A. Lautenschleger, A. Olenberg, E.Y. Kenig
A systematic CFD-based method to investigate and optimise novel structured packings
Chem. Eng. Sci. 122 452-464 (2015)

[5]   R.F. Engberg, E.Y. Kenig
An investigation of the influence of initial deformation on fluid dynamics of toluene droplets in water
Int. J. Multiphase Flow 76 144–157 (2015)

[6]  M. Piper, A. Zibart, E. Djakow, R. Springer, W. Homberg, E.Y. Kenig
Heat transfer enhancement in pillow-plate heat exchangers with dimpled surfaces: A numerical study
Appl. Therm. Eng. 153, 142-146 (2019)