Tubes arrangement aligned horizontally is main type for ice-on-tube ice storage tank. The arrangement rationality is general requirement in equipment designation. The understanding for characteristics of ice formation around tubes is helpful for optimizating design. This paper studied experimentally the behavior of ice formation around the tubes under the arrangement of nine tubes aligned horizontally in a rectangular container

and the interaction among the tubes. The results shows that the beginning of water freezing aroung middle tubes is late than other tubes due to be affteced by induced natural convection when the initial water temperature in test section is high. The developing of ice layer around middle tube is superior than around upper and lower tube by comparing the volume of ice formed around the central row tubes. If the water freezing around all tubes oucurs simutaneously after beginging of cooling storage process

the non-dimentional temperature could be taken as a property to estimate the increasing rate of ice formation around tubes. The smaller the non-dimentional temperature is

the quicker the ice layer increases around the tubes.