Trends in the Development of Machinery and Associated Technology

Aleš Hribernik, Matej Fike, Boštjan Gregorc
2011 unpublished
Electromagnetic losses within a hydro-generator are sources of heat which heat the generator, and then have to be conducted away. This may, however, cause a temperature rise of the stator bars thus reducing the lifespan of the insulation materials. Therefore, any temperature rise of the stator windings is limited. In order to inspect the operation of a cooling-system, several temperature sensors have to be integrated into the stator core in order to measure its temperature, which should not
more » ... hich should not exceed 80 0 C. Temperature measurements performed on a generator showed some deviations from the design temperatures, especially at full-power operation. Thus, an attempt was made to analyse the operation of a cooling-system, and to eventually increase its cooling capacity. It was impossible to perform any complex measurements during the generator's operation, due to safety reasons. Therefore, our work was limited to 3D CFD simulations using ANSYS CFX 11 solver. The simulations were partly supported by the measurements of some main integral parameters, such as mass-flow rate and pressure drop across the cooling ducts and radiators, as performed during generator idling. The results are presented and discussed in this paper.