Conjugate Heat Transfer In A Partially Open Cubic Enclosure With A Heat-generating Conducting Body

Conjugate heat dissipation processes in partially open cavities with a heat-generating body have been studied numerically and experimently. Firstly, comprehensive numerical study has been carried out to investigate three-dimensional, steady, conjugate heat transfer of natural convection, conduction and radiation in a partially open enclosure with a heat-generating, centered, cubic conducting body, which occurs in the thermal engineering system of transformer substation.By the numerical results, it has been shown that the flow in whole partly open enclosure is a complicated 3-D flow. The heat transfer performance can be improved by elevating the position of heat-generating body in gravitational direction and the height of the whole enclosure and increasing the surface area of the heat-generating body and its emissivity. Secondly,the ventilation of the underground transformer cell has been calculated. Considering that the inlet and outlet are sited on the same horizontal, a plate has been designed under the inlet in order to make the fresh air flow into the bottom of the main heat-generating (transformer) without interference. And the results showed that there is an optimal value for the height of the plate.Then the design for the outlet was carried out with thermal analyses.Thirdly,the conjugate heat transfer of forced convection, conducation and radation with a heat-generating body in the heat exchanger room of large-scale indoor transformer substation was numerically studied. The heat transfer was improved when a vent-pipe was applied between the fan and environment and the highest temperature of transformer decreased obviously. The method of optimization that is the combination of heat transfer and thermodynamics has been tried and it was found that the fan power requirement is minimum when the heat transfer contact area is optimized to a value that is , where the Af is the flow cross-sectional area.In the end,the temperature field in both transformer room and heat exchanger room was measured by PT100 for checking the mathematical model used in this paper. The results obtained by numerical method are in good agreement with those of the experimental measurement. f2St A...