Performance analysis of a refrigeration system integrated with a thermoelectric cooler and microchannels in terms of heat transfer using a hybrid nanofluid

Advancements in chip technology increase energy consumption due to larger chip capacity, leading to intensive heat flux generation. Cooling solutions, including fan-only, fan-conventional heat sink (HS), or fan-conventional HS-heat pipe (HP) integrated systems, face penalties such as noise, dust accumulation, high electricity usage, space constraints, and thermal limitations of the working fluid. While thermoelectric coolers (TEC) have advantages like compactness and noise-free operation, they alone are insufficient for cooling sophisticated chips; combining them with microchannel heat sinks (MCHS) and superior fluid is crucial for achieving faster and more efficient cooling. Considering previous studies involving TECs used alone, with conventional fluids integrated into MCHS, and with a mono-nanofluid integrated into MCHSs, this is the first study to consider a TEC integrated with two MCHSs and to use a ZnO-TiO2/water hybrid nanofluid to maximize the performance of this miniature refrigeration system. Accordingly, an experimental study was carried out on the aforementioned refrigeration system using various concentrations (phi) of ZnO-TiO2/water hybrid nanofluid for different flow rates, utilizing both conventional heat transfer and the TEC's mathematical operating principle. The results were interpreted via Reynolds number, Prandtl number, heat transfer rate, Nusselt number, total thermal resistance, and coefficient of performance (COP). The increase in phi from 0% to 0.03%, accompanied by a decrease in flow rate from 16 x 10-5 m3/s to 9 x 10-5 m3/s, increased the heat transfer rate for the heat-absorbing and the heat-emitting sides of the refrigeration system from 19.510 W to 45.794 W, and 13.639 W to 22.406 W, respectively. The experimental COP for pure water was 0.325 at the lowest volume flow rate, but increased to 0.934 at a phi of 0.030%. Considering the thermal characteristics, this study demonstrates that the proposed system is particularly advantageous at low flow rates and high phi, making it a potential candidate for electronic circuit cooling. Considerations such as investigating certain material properties to allow for further improvement of the proposed system were offered.