Heat sink design for a thermoelectric cooling system

Thermal performance of louver fin, offset strip fin and plate fin in a thermoelectric cooling system with a duct-flow type fan arrangement is analytically examined. The thermoelectric cooling system is composed of a water jacket, an array of thermoelectric modules and a heat sink. Heat sinks with dimension of 39.7 mm times 119.1 mm plane area and 40 mm fin height are considered for the performance comparison. In order to estimate the base plate temperature of the heat sink, the thermal performance of a thermoelectric module (Ferro Tec: TE 9500-127-060B) is taken into account. From the Colburn j factor correlations for louver fins and offset strip fins and the Nusselt number correlation for plate fin heat sinks, the convective thermal resistances of heat sinks are evaluated at the determined operating air velocity. The thermal performance of TEM with the calculated convective thermal resistance is evaluated. The results show that the thermoelectric cooling system with optimized plate fin heat sink provides 24.4% higher COP (coefficient of performance) and 27.7% higher heat absorbed compared to the optimized louver fin heat sink, respectively. The optimized offset strip fin heat sink shows a slightly higher COP and heat absorbed than the optimized plate fin heat sink. However, the optimized louver fin heat sink has a lowest outlet air temperature with a reduced air flow rate due to a higher pressure drop.