Analysis of Unsteady Heat Transfer during Ice-Making Process for Ice Rink Buildings

The ice-making process is an important factor that affects the ice quality and the energy consumption of ice rinks. An unsteady heat transfer model is established and validated for the ice-making process. The transient temperature variation and ice thickness growing characteristics during the ice-making process are analyzed. The freezing time of a water layer and the final temperature of the stabilized ice layer are quantified. The effects of ice rink structural parameters on the ice-making process are studied. The results show that the water temperature variations during the process go through three stages. The ice-growing process mainly occurs in the second stage. The ice-making process takes about 305 min-420 min for a water layer of 5 mm thickness. The reduction in the ice-making time and the decrease in the final temperature of the stabilized ice layer can be attained by reducing the water layer thickness, the surface heat flux, the cooling pipe spacing, the fluid temperature in the cooling pipe, or the top concrete thickness. Among them, the influences of the thickness of the water layer, the surface heat flux, and the fluid temperature in the cooling pipe are more significant. As the thickness of the water layer decreases from 7 mm to 3 mm, the total ice-making time decreases by about 37.6%. The ice-making time is reduced by 17.1% with the surface heat flux decreasing from 330 W/m(2) to 250 W/m(2). The ice-making time is reduced by 21.4% with the cooling pipe temperature decreasing from -15.5 degrees C to -19.5 degrees C.