The prediction of the thermal and hydraulic performance of underground electric transmission systems with turbulent forced convection cooling
Abstract
Heat transfer and friction factors were experimentally determined in a scale model of high voltage underground transmission systems for Reynolds numbers up to 8000. Two ratios of cable to enclosure pipe were considered, corresponding to standard and oversize enclosure pipes. Helical wire wrap was included to simulate protective skid wires around the cables. Three configurations of cable positioning were considered. A method of generalizing the heat transfer coefficients was developed and tested for pipe cables. Friction factors were determined experimentally for cables with up to 13 percent snaking, to simulate cable buckling due to thermal expansion. Hydraulic losses downstream of a buckled section, and through a sudden expansion at the outlet of a cable system were developed for friction factor as a function of cable snaking.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1981
- Bibcode:
- 1981PhDT........54G
- Keywords:
-
- Convective Heat Transfer;
- Cooling;
- Forced Convection;
- Friction Factor;
- Hydraulic Control;
- Turbulent Heat Transfer;
- Underground Transmission Lines;
- Finite Difference Theory;
- Heat Transfer Coefficients;
- Prediction Analysis Techniques;
- Thermal Buckling;
- Thermal Expansion;
- Electronics and Electrical Engineering