Effects of feed water temperature, pool temperature, and pool side heat transfer coefficient on freezing time of the conventional block ice production

摘要

Computational fluid dynamic (CFD) model was developed for predicting the effects of water temperature for producing ice in a box immersed in a pool containing brine water, the pool temperature and the pool side heat transfer coefficient on the water freezing time of the block ice box. Results from the model were agreed very well with those of onsite experiments of the conventional plant. The obtained model was used to predict the effects of the pool temperatures, the feed water temperatures and the pool side heat transfer coefficients ranging from -5°C to -20°C, 0°C to 40°C and 250W/m~2oC to 50,000W/m~2oC respectively on the freezing time of the block ice production having the dimension of 0.27 m x 0.56 m x 1.484 m. It was found that the pool temperature was the major factor. The minor factor was the feed water temperature whereas the heat transfer coefficient had not a significant effect. The freezing time decreased dramatically when the pool temperature not less than -7°C and gradually decreased until the temperature reached -12°C after that it fairly unchanged. The optimum pool temperature was suggested to be -10°C. At that pool temperature, the freezing time could be reduced from 45.20 hr to 44.24 hr when the feed water temperature reduced from 29.5°C to 5°C. The obtained results reveal the useful information for design and optimizing the plant operation which has not found in literature.