MEASUREMENT OF LOCAL HEAT TRANSFER COEFFICIENTS ON FOOD PRODUCTS USING AN IN SITU CALORIMETRIC METHOD
In this work an in situ calorimetric method was investigated to measure local heat transfer coefficients on vegetables submitted to freezing processes. Three products were used: tomato (sphere), French courgette and green beans (cylinder). The air speed conditions employed were respectively, 0 (natural convection), 1, 3, 5 and 7 m.s-1. To validate the measured coefficients, two other methods were employed. One was based on the replacement of the products by copper bodies (tomato and courgette) and by acrylic cylinders (green beans) of same geometry and reproduction of the othe experimental conditions. The coefficients were obtained by regression analysis of the cooling curves. The second method estimated the coefficients by using relations of the type Nu = f(Re). The values measured by in situ calorimetry are in accordance with those obtained by the other methods. Moreover, the calorimetric method enables the measurement of local values, while the others result in an overall coefficient. The coefficients obtained for green beans were used for the simulation of the freezing time employing a numerical enthalpic finite difference method. Simulated curves fitted well (R2 ＞ 0.95) to experimental ones.
ALVARO AMARANTE JEAN-LOUIS LANOISELL(E)
Pontifícia Universidade Católica do Paraná, Mechanical Engineering Department, PPGEM P.O. Box 17,315 Université de Technologie de Compiègne, Laboratoire Génie de Procédés Industriels, P.O. Box 20,529;
国际会议
The 22nd International Congress of Refrigeration(第22届国际制冷大会)
北京
英文
2007-08-21（万方平台首次上网日期，不代表论文的发表时间）