Author(s): Tatsuaki Nakato; Keiichi Toda; Robert Ettema
Keywords: No Keywords
Abstract: A difficulty commonly encountered in winter-time management of navigation lock-and-dam installations is unwanted ice growth. Ice collars generally form along lockwalls and miter gates, and create a variety of problems for lock operation, such as difficulty in operating miter gates, reduction in the effective lock width, interference with vessel passage, etc. Typically, ice collars have had to be mechanically removed by means of such devices as chainsaw cutters, backhoe scrapers, pike poles, high-pressure water and steam jets, etc. A promising means of controlling, even preventing, ice growth along lockwalls is by embedded heaters. However, no thermal analysis has been reported on power requirements for ice control by means of heaters embedded in concrete walls. The investigation reported herein was focused on mathematically analyzing thermal character! sties of various configurations of heat sources placed in concrete lockwalls. The configurations analyzed include: a continuous planar heat source, a line heat source, and a rectangular boundary containing two line heat sources. For each configuration, analytical solutions were obtained for temporal distributions of temperature within the concrete boundary, temporal rate of heat transfer at the lockwall surface, and accumulated total heat expended after prescribed times of application. Although each analysis employed simplified, idealized boundary conditions, the results were found to provide useful engineering information on heating requirements for lockwalls in controlling ice growth.