ISHS Acta Horticulturae 674: III International Symposium on Applications of Modelling as an Innovative Technology in the Agri-Food Chain; MODEL-IT
MODELLING OF TWO-DIMENSIONAL HEAT AND MASS TRANSFER DURING VACUUM COOLING OF COOKED RICE IN TRAY |
| Authors: | Z. Zhang, D.-W. Sun |
| Keywords: | vacuum cooling, rice, heat and mass transfer, condensation, numerical model. |
| Abstract:
Vacuum cooling of rice in a tray was modelled, using finite volume method. The model describes the heat conduction and moisture diffusion within the rice grains, evaporation of moisture at the surface of the grains, flowing of vapour in the rice bed, condensation and/or evaporation of vapour in vacuum chamber and condenser, leakage of air into the chamber, and evacuation of gas in the free volume out of the vacuum cooling system through vacuum pump. About 2.49 kg cooked rice was vacuum cooled from about 100°C to 4°C. The deviation between the predicted and experimental total final mass was only 0.42%. The predicted vacuum cooling time agreed with experimental cooling time very well, within the variation of experimental values. Root mean squared errors of the top and middle layer temperatures and the weight were 3.69°C, 6.85°C and 12 g, respectively, indicating the accuracy of the prediction from the model. | |
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