Abstract: In the winter,ethylene glycol solution usually used in the closed cooling system instead of water as the antifreeze. Due to the changes in physical properties,its heat carrying capacity and convective heat transfer coefficient has declined. Based on the theory of closed-tower design,we studied the influence of the heat transfer different concentrations and different seasons to the Ethylene Glycol solution used in the closed cooling tower circulation; supposed that use a large diameter-thin walled tube,increase the flow rate of Ethylene Glycol solution cycle working fluid or increase the amount of ventilation rate,and reveals the variation in the different operating modes.

Key words: closed cooling tower, ethylene glycol solution, heat transfer coefficient