الفهرس | Only 14 pages are availabe for public view |
Abstract Numerical analysis has been performed using finite element program to investigate the of different aspects on buried electric cable temperature. It was found that increasing trench width, trench depth, cable diameter, native soil thermal conductivity and backfilling thermal conductivity decreases cable’s while, increasing cable heat flux, cable depth, air temperature and initial soil temperature increasing cable’s temperature. Also numerical analysis shows that groundwater table depth has no effect on cable’s temperature. Numerical analysis results is also used to construct a guide design chart used for designing trenches for buried electric cables. Also a basic computer program in a friendly form has been developed based on the guide design chart curves equations, this basic computer program facilitates the design of trenches and also, provide more accurate results. Finally, a thermal property probe has been developed which is used for measuring value of soil thermal conductivity in both laboratory and field. It has been used to conduct some laboratory tests to investigate effect of soil grading, density and water content on soil thermal conductivity using sand samples and it was found that both density and water content are directly proportional to sand thermal conductivity while, uniformity coefficient is inversely proportional to sand thermal conductivity. |