Minichannel heat sinks are widely adopted heat dissipation solutions from miniaturized heat flux generating components, such as microprocessors. This paper presents further enhancements in the thermal and hydraulic performance of a minichannel heat sink by employing supercritical carbon dioxide (sCO₂) as a coolant. In this study, thermal and hydraulic performance of CO₂-cooled minichannel heat sink at three inlet pressures ($P_{in,C{O}_2}$) (i.e., 8.0, 10 and 12 MPa$)$and inlet temperatures ($T_{in,C{O}_2}$) ranging between ${30}^{\circ }C-{60}^{\circ }C$ is compared with a water-cooled minichannel heat sink at inlet conditions $($0.1 MPa$,$30 °C$-$38 °C$)$. To investigate the performance of the minichannel heat sinks, a conjugate heat transfer model is solved in a commercial code ANSYS-CFX. Whereas the variations in thermo-physical properties of supercritical carbon dioxide (sCO₂) are incorporated in ANSYS-CFX through a real gas property (RGP) table. The results reveal a maximum enhancement of 42.13% in average heat transfer coefficient ($\overline{h}$) for minichannel heat sink using CO₂ as a coolant at inlet conditions of 8.0 MPa and${34}^{\circ }C$. Similarly, a pressure drop reduction of 55.79% is computed for CO₂ as a coolant at corresponding inlet conditions as compared to water-cooled minichannel heat sink. Moreover, the results suggest that replacing water with CO₂ as a coolant at higher inlet pressures $\left(P_{in,C{O}_2}\right)$ i.e., 10 MPa and 12 MPa$$can further reduce pressure drops in the minichannel heat sink by 60.65% and 62.41%, respectively. Apart from the lower base temperatures, performance evaluation criteria $\left(PEC\right)$ suggests that the overall performance of the minichannel heat sink using CO₂ at 8.0 MPa is roughly enhanced by 2 times as compared to water-cooled minichannel heat sink.

微型通道散热器是广泛采用的小型化热通量产生组件的散热解决方案，例如微处理器。本文介绍了通过使用超临界二氧化碳 (sCO ₂ ) 作为冷却剂来进一步增强微通道散热器的热性能和水力性能。在这项研究中，CO ₂冷却的微通道散热器在三个入口压力下的热和水力性能（${磷}_{\mathrm{一世}n,C{哦}_2}$)（即 8.0、10 和 12 MPa$)$和入口温度（${吨}_{\mathrm{一世}n,C{哦}_2}$) 介于 ${30}^{\circ }C-{60}^{\circ }C$ 在入口条件下与水冷微通道散热器进行比较 $($0.1兆帕$,$30° Ç$-$38℃$)$. 为了研究微通道散热器的性能，在商业代码 ANSYS-CFX 中求解了共轭传热模型。而超临界二氧化碳 (sCO ₂ ) 的热物理特性的变化通过真实气体特性 (RGP) 表合并到 ANSYS-CFX 中。结果表明，平均传热系数最大提高了 42.13%（$\overline{H}$) 用于在 8.0 MPa 的入口条件下使用 CO ₂作为冷却剂的微型通道散热器和${34}^{\circ }C$. 类似地，与水冷微通道散热器相比，在相应的入口条件下，CO ₂作为冷却剂的压降降低了 55.79% 。此外，结果表明，在较高的入口压力下用 CO ₂代替水作为冷却剂$\left({磷}_{\mathrm{一世}n,C{哦}_2}\right)$ 即 10 MPa 和 12 MPa$$可以进一步将微通道散热器中的压降分别降低 60.65% 和 62.41%。除了较低的基础温度，性能评估标准$\left(磷乙C\right)$表明与水冷微通道散热器相比，在 8.0 MPa 下使用 CO ₂的微通道散热器的整体性能大致提高了 2 倍。