DOI: 10.1615/ICHMT.2004.IntThermSciSemin
ISBN Print: 978-9-61913-930-1
Theoretical Prediction of the Thermal Conductivity of Frozen Foods
要約
Frozen food is theoretically modelled as a porous medium, consisting of an arrangement of cubic fibers surrounded by ice and unfrozen water. The original model, developed for frozen soils, has been improved for the prediction of the thermal conductivity of frozen foods as a function of water content, porosity and temperature.
The theoretical prediction of the thermal conductivity is carried out with the solution of the heat conduction equation under the assumption of a prescribed temperature or heat flux distribution. Two thermal conductivity values are then obtained, based on two thermal assumptions, i.e. parallel isotherms or parallel heat flux lines, in order to confine the real solution within the two extremes.
The amount of unfrozen water, present in the frozen food, has been taken from the experimental data, using an empirical relation dependent on the temperature.
The final comparison has been carried out between the theoretical solutions and the experimental data available in the literature, in the temperature range from 0° C to −40° C. The theoretical results show a fair agreement with the experimental data.