Optimization and thermal performance evaluation of a closed-loop water-cooling system for thermoelectric generators

A closed water-cooled system with an optimized heat sink is presented for thermoelectric generators to overcome the limitations of conventional open cooling water system designs in terms of water consumption and applicability. Parametric CFD simulations were employed to systematically optimize the geometric configuration of fins and flow channels. Simulation results reveal that thermal performance improves with increased fin height, channel length, or cross-sectional area, whereas wider fin spacing reduces effectiveness due to diminished convective heat transfer. Experimental validation under variable operating conditions demonstrates optimal performance at a flow rate of 2 L/min, achieving a peak heat dissipation power of 331 W. The system attains thermal equilibrium within 17 minutes, with temperature fluctuations below 2.1 °C for the heat sink and 1.1 °C for the cooler. Key findings reveal that fin geometric parameters dominate thermal performance, with the height-to-spacing ratio critical for balancing heat transfer area and turbulence. An intermediate flow rate optimizes the trade-off between mass flow and temperature gradient, while time-dependent experimental analysis proves essential for system stability. This study provides a validated framework for designing compact, water-efficient TEG cooling systems, offering significant potential for waste heat recovery in energy-intensive applications.