Assessment of Fin Shape and Height and Reservoir Elevation on the Performance of a TEG Cooling System

Effect of the reservoir elevation, fin shape and height on the cooling performance of a heat sink equipped with a liquid thermosyphon system, for a thermoelectric generator (TEG) application is studied using numerical simulations. Three pin fin types, namely circular, circular sector and triangular shapes, with a staggered arrangement, are employed for the heat sink and performance of each type for a wide range of fin heights and two hydraulic diameters is demonstrated. It is found that the highest cooling performance is achieved, when the reservoir is placed at the same level as the heat sink. Hence, a more compact TEG-thermosyphon assembly, which requires less space, with better cooling efficiency, compared with traditional designs with the reservoir placed on top of the heat sink, is achieved. Simulations show that the heat sink with circular-sector fins has a better thermal efficiency at a wide range of fin heights, compared with the two other fin shapes, for the current application. It was also found that, with a suitable hydraulic diameter, circular-sector fins can provide reasonably low pressure drop for a wide range of fin heights.