Enhanced Dropwise Condensation for Improved Dry Cooling Efficiency

Industrial and utility applications utilizing dry cooling for condensing process steam are less efficient than their closed-loop cooling counterparts, resulting in higher energy consumption and operating costs. However, dry cooling is a necessary process in areas where cooling water supply is not available due to competing demands for water. The inefficiencies in dry cooling are largely due to the condensation heat transfer process in the condensing tubes. The objective of the proposed Phase I effort is to enhance the condensation heat transfer within the condensing tubes using a cost effective coating method, thereby improving dry cooling efficiency. Improving the efficiency of dry cooling operations will reduce the size of dry cooling systems, carbon emission and power consumption for cooling fans. Ultimately, this will result in approximately 15% reduction in capital and operating costs. During the Phase I effort, the cost effective coating system will be evaluated for improved condensation heat transfer compared to a baseline system. Additionally, a representative dry cooling system for a large power generation facility (~1.8 GWt) will be modeled using experimentally determined heat transfer coefficients to reveal the improvement in, not only dry cooling efficiency, but also power generation efficiency. The proposed coating technology will be applicable to copper condensing tubes currently used in dry cooling systems by a cost-effective method, thus making the conversion to the more efficient condensation process attractive and affordable.